US20070091418A1 - Methods for driving electro-optic displays, and apparatus for use therein - Google Patents

Methods for driving electro-optic displays, and apparatus for use therein Download PDF

Info

Publication number
US20070091418A1
US20070091418A1 US11/611,324 US61132406A US2007091418A1 US 20070091418 A1 US20070091418 A1 US 20070091418A1 US 61132406 A US61132406 A US 61132406A US 2007091418 A1 US2007091418 A1 US 2007091418A1
Authority
US
United States
Prior art keywords
medium
display
electro
pulse
optic
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US11/611,324
Inventor
Guy Danner
Karl Amundson
Robert Zehner
Alexi Arango
Jay Ewing
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
E Ink Corp
Original Assignee
E Ink Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from US09/520,743 external-priority patent/US6504524B1/en
Priority claimed from US09/561,424 external-priority patent/US6531997B1/en
Priority claimed from US10/065,795 external-priority patent/US7012600B2/en
Application filed by E Ink Corp filed Critical E Ink Corp
Priority to US11/611,324 priority Critical patent/US20070091418A1/en
Publication of US20070091418A1 publication Critical patent/US20070091418A1/en
Priority to US11/751,879 priority patent/US20080024482A1/en
Priority to US14/680,121 priority patent/US9966018B2/en
Priority to US14/816,226 priority patent/US10319314B2/en
Abandoned legal-status Critical Current

Links

Images

Classifications

    • GPHYSICS
    • G09EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09GARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/34Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
    • G09G3/3433Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source using light modulating elements actuated by an electric field and being other than liquid crystal devices and electrochromic devices
    • G09G3/344Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source using light modulating elements actuated by an electric field and being other than liquid crystal devices and electrochromic devices based on particles moving in a fluid or in a gas, e.g. electrophoretic devices
    • GPHYSICS
    • G02OPTICS
    • G02FOPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/165Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on translational movement of particles in a fluid under the influence of an applied field
    • G02F1/166Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on translational movement of particles in a fluid under the influence of an applied field characterised by the electro-optical or magneto-optical effect
    • G02F1/167Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on translational movement of particles in a fluid under the influence of an applied field characterised by the electro-optical or magneto-optical effect by electrophoresis
    • GPHYSICS
    • G09EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09GARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/2007Display of intermediate tones
    • GPHYSICS
    • G09EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09GARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/2007Display of intermediate tones
    • G09G3/2011Display of intermediate tones by amplitude modulation
    • GPHYSICS
    • G09EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09GARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2300/00Aspects of the constitution of display devices
    • G09G2300/08Active matrix structure, i.e. with use of active elements, inclusive of non-linear two terminal elements, in the pixels together with light emitting or modulating elements
    • GPHYSICS
    • G09EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09GARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2310/00Command of the display device
    • G09G2310/02Addressing, scanning or driving the display screen or processing steps related thereto
    • GPHYSICS
    • G09EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09GARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2310/00Command of the display device
    • G09G2310/02Addressing, scanning or driving the display screen or processing steps related thereto
    • G09G2310/0243Details of the generation of driving signals
    • G09G2310/0254Control of polarity reversal in general, other than for liquid crystal displays
    • GPHYSICS
    • G09EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09GARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2310/00Command of the display device
    • G09G2310/02Addressing, scanning or driving the display screen or processing steps related thereto
    • G09G2310/0264Details of driving circuits
    • G09G2310/027Details of drivers for data electrodes, the drivers handling digital grey scale data, e.g. use of D/A converters
    • GPHYSICS
    • G09EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09GARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2310/00Command of the display device
    • G09G2310/04Partial updating of the display screen
    • GPHYSICS
    • G09EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09GARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2310/00Command of the display device
    • G09G2310/06Details of flat display driving waveforms
    • GPHYSICS
    • G09EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09GARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2310/00Command of the display device
    • G09G2310/06Details of flat display driving waveforms
    • G09G2310/061Details of flat display driving waveforms for resetting or blanking
    • GPHYSICS
    • G09EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09GARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2310/00Command of the display device
    • G09G2310/06Details of flat display driving waveforms
    • G09G2310/061Details of flat display driving waveforms for resetting or blanking
    • G09G2310/063Waveforms for resetting the whole screen at once
    • GPHYSICS
    • G09EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09GARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2310/00Command of the display device
    • G09G2310/06Details of flat display driving waveforms
    • G09G2310/068Application of pulses of alternating polarity prior to the drive pulse in electrophoretic displays
    • GPHYSICS
    • G09EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09GARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2320/00Control of display operating conditions
    • G09G2320/02Improving the quality of display appearance
    • G09G2320/0204Compensation of DC component across the pixels in flat panels
    • GPHYSICS
    • G09EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09GARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2320/00Control of display operating conditions
    • G09G2320/02Improving the quality of display appearance
    • G09G2320/0209Crosstalk reduction, i.e. to reduce direct or indirect influences of signals directed to a certain pixel of the displayed image on other pixels of said image, inclusive of influences affecting pixels in different frames or fields or sub-images which constitute a same image, e.g. left and right images of a stereoscopic display
    • G09G2320/0214Crosstalk reduction, i.e. to reduce direct or indirect influences of signals directed to a certain pixel of the displayed image on other pixels of said image, inclusive of influences affecting pixels in different frames or fields or sub-images which constitute a same image, e.g. left and right images of a stereoscopic display with crosstalk due to leakage current of pixel switch in active matrix panels
    • GPHYSICS
    • G09EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09GARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2320/00Control of display operating conditions
    • G09G2320/02Improving the quality of display appearance
    • G09G2320/0247Flicker reduction other than flicker reduction circuits used for single beam cathode-ray tubes
    • GPHYSICS
    • G09EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09GARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2320/00Control of display operating conditions
    • G09G2320/02Improving the quality of display appearance
    • G09G2320/0252Improving the response speed
    • GPHYSICS
    • G09EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09GARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2320/00Control of display operating conditions
    • G09G2320/02Improving the quality of display appearance
    • G09G2320/0285Improving the quality of display appearance using tables for spatial correction of display data
    • GPHYSICS
    • G09EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09GARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2320/00Control of display operating conditions
    • G09G2320/04Maintaining the quality of display appearance
    • G09G2320/041Temperature compensation
    • GPHYSICS
    • G09EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09GARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2320/00Control of display operating conditions
    • G09G2320/04Maintaining the quality of display appearance
    • G09G2320/043Preventing or counteracting the effects of ageing
    • GPHYSICS
    • G09EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09GARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2330/00Aspects of power supply; Aspects of display protection and defect management
    • G09G2330/02Details of power systems and of start or stop of display operation
    • G09G2330/021Power management, e.g. power saving
    • GPHYSICS
    • G09EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09GARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2340/00Aspects of display data processing
    • G09G2340/16Determination of a pixel data signal depending on the signal applied in the previous frame
    • GPHYSICS
    • G09EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09GARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/2007Display of intermediate tones
    • G09G3/2014Display of intermediate tones by modulation of the duration of a single pulse during which the logic level remains constant
    • GPHYSICS
    • G09EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09GARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/2007Display of intermediate tones
    • G09G3/2018Display of intermediate tones by time modulation using two or more time intervals
    • GPHYSICS
    • G09EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09GARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/2007Display of intermediate tones
    • G09G3/2074Display of intermediate tones using sub-pixels
    • GPHYSICS
    • G09EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09GARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/2007Display of intermediate tones
    • G09G3/2077Display of intermediate tones by a combination of two or more gradation control methods
    • GPHYSICS
    • G09EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09GARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/34Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
    • G09G3/3433Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source using light modulating elements actuated by an electric field and being other than liquid crystal devices and electrochromic devices
    • G09G3/3453Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source using light modulating elements actuated by an electric field and being other than liquid crystal devices and electrochromic devices based on rotating particles or microelements

Definitions

  • This invention relates to methods and apparatus for driving electro-optic displays, particularly bistable electro-optic displays.
  • the methods and apparatus of the present invention are especially, though not exclusively, intended for use in driving bistable electrophoretic displays.
  • optical-optic as applied to a material or a display, is used herein in its conventional meaning in the imaging art to refer to a material having first and second display states differing in at least one optical property, the material being changed from its first to its second display state by application of an electric field to the material.
  • the optical property is typically color perceptible to the human eye, it may be another optical property, such as optical transmission, reflectance, luminescence or, in the case of displays intended for machine reading, pseudo-color in the sense of a change in reflectance of electromagnetic wavelengths outside the visible range.
  • gray state is used herein in its conventional meaning in the imaging art to refer to a state intermediate two extreme optical states of a pixel, and does not necessarily imply a black-white transition between these two extreme states.
  • extreme states are white and deep blue, so that an intermediate “gray state” would actually be pale blue. Indeed, as already mentioned the transition between the two extreme states may not be a color change at all.
  • bistable and “bistability” are used herein in their conventional meaning in the art to refer to displays comprising display elements having first and second display states differing in at least one optical property, and such that after any given element has been driven, by means of an addressing pulse of finite duration, to assume either its first or second display state, after the addressing pulse has terminated, that state will persist for at least several times, for example at least four times, the minimum duration of the addressing pulse required to change the state of the display element.
  • some particle-based electrophoretic displays capable of gray scale are stable not only in their extreme black and white states but also in their intermediate gray states, and the same is true of some other types of electro-optic displays. This type of display is properly called “multi-stable” rather than bistable, although for convenience the term “bistable” may be used herein to cover both bistable and multi-stable displays.
  • impulse is used herein in its conventional meaning of the integral of voltage with respect to time.
  • bistable electro-optic media act as charge transducers, and with such media an alternative definition of impulse, namely the integral of current over time (which is equal to the total charge applied) may be used.
  • the appropriate definition of impulse should be used, depending on whether the medium acts as a voltage-time impulse transducer or a charge impulse transducer.
  • bistable electro-optic displays are known.
  • One type of electro-optic display is a rotating bichromal member type as described, for example, in U.S. Pat. Nos. 5,808,783; 5,777,782; 5,760,761; 6,054,071 6,055,091; 6,097,531; 6,128,124; 6,137,467; and 6,147,791 (although this type of display is often referred to as a “rotating bichromal ball” display, the term “rotating bichromal member” is preferred as more accurate since in some of the patents mentioned above the rotating members are not spherical).
  • Such a display uses a large number of small bodies (typically spherical or cylindrical) which have two or more sections with differing optical characteristics, and an internal dipole. These bodies are suspended within liquid-filled vacuoles within a matrix, the vacuoles being filled with liquid so that the bodies are free to rotate. The appearance of the display is changed to applying an electric field thereto, thus rotating the bodies to various positions and varying which of the sections of the bodies is seen through a viewing surface.
  • bodies typically spherical or cylindrical
  • These bodies are suspended within liquid-filled vacuoles within a matrix, the vacuoles being filled with liquid so that the bodies are free to rotate.
  • the appearance of the display is changed to applying an electric field thereto, thus rotating the bodies to various positions and varying which of the sections of the bodies is seen through a viewing surface.
  • electro-optic medium uses an electrochromic medium, for example an electrochromic medium in the form of a nanochromic film comprising an electrode formed at least in part from a semi-conducting metal oxide and a plurality of dye molecules capable of reversible color change attached to the electrode; see, for example O'Regan, B., et al., Nature 1991, 353, 737; and Wood, D., Information Display, 18(3), 24 (March 2002). See also Bach, U., et al., Adv. Mater., 2002, 14(11), 845. Nanochromic films of this type are also described, for example, in U.S. Pat. No. 6,301,038, International Application Publication No. WO 01/27690, and in copending application Ser. No. 10/249,128 filed Mar. 18, 2003 (now U.S. Pat. No. 6,950,220).
  • Electrophoretic display Another type of electro-optic display, which has been the subject of intense research and development for a number of years, is the particle-based electrophoretic display, in which a plurality of charged particles move through a suspending fluid under the influence of an electric field.
  • Electrophoretic displays can have attributes of good brightness and contrast, wide viewing angles, state bistability, and low power consumption when compared with liquid crystal displays. Nevertheless, problems with the long-term image quality of these displays have prevented their widespread usage. For example, particles that make up electrophoretic displays tend to settle, resulting in inadequate service-life for these displays.
  • encapsulated electrophoretic media comprise numerous small capsules, each of which itself comprises an internal phase containing electrophoretically-mobile particles suspended in a liquid suspension medium, and a capsule wall surrounding the internal phase.
  • the capsules are themselves held within a polymeric binder to form a coherent layer positioned between two electrodes. Encapsulated media of this type are described, for example, in U.S. Pat. Nos.
  • An encapsulated electrophoretic display typically does not suffer from the clustering and settling failure mode of traditional electrophoretic devices and provides further advantages, such as the ability to print or coat the display on a wide variety of flexible and rigid substrates.
  • printing is intended to include all forms of printing and coating, including, but without limitation: pre-metered coatings such as patch die coating, slot or extrusion coating, slide or cascade coating, curtain coating; roll coating such as knife over roll coating, forward and reverse roll coating; gravure coating; dip coating; spray coating; meniscus coating; spin coating; brush coating; air knife coating; silk screen printing processes; electrostatic printing processes; thermal printing processes; ink jet printing processes; and other similar techniques.
  • pre-metered coatings such as patch die coating, slot or extrusion coating, slide or cascade coating, curtain coating
  • roll coating such as knife over roll coating, forward and reverse roll coating
  • gravure coating dip coating
  • spray coating meniscus coating
  • spin coating spin coating
  • brush coating air knife coating
  • silk screen printing processes electrostatic printing processes
  • thermal printing processes
  • microcell electrophoretic display A related type of electrophoretic display is a so-called “microcell electrophoretic display”.
  • the charged particles and the suspending fluid are not encapsulated within microcapsules but instead are retained within a plurality of cavities formed within a carrier medium, typically a polymeric film.
  • a carrier medium typically a polymeric film.
  • electrophoretic displays are often opaque (since the particles substantially block transmission of visible light through the display) and operate in a reflective mode
  • electrophoretic displays can be made to operate in a so-called “shutter mode” in which the particles are arranged to move laterally within the display so that the display has one display state which is substantially opaque and one which is light-transmissive.
  • shutter mode in which the particles are arranged to move laterally within the display so that the display has one display state which is substantially opaque and one which is light-transmissive.
  • Dielectrophoretic displays which are similar to electrophoretic displays but rely upon variations in electric field strength, can operate in a similar mode; see U.S. Pat. No. 4,418,346.
  • Other types of electro-optic displays may also be capable of operating in shutter mode.
  • LC displays The bistable or multi-stable behavior of particle-based electrophoretic displays, and other electro-optic displays displaying similar behavior, is in marked contrast to that of conventional liquid crystal (“LC”) displays. Twisted nematic liquid crystals act are not bi- or multi-stable but act as voltage transducers, so that applying a given electric field to a pixel of such a display produces a specific gray level at the pixel, regardless of the gray level previously present at the pixel. Furthermore, LC displays are only driven in one direction (from non-transmissive or “dark’ to transmissive or “light”), the reverse transition from a lighter state to a darker one being effected by reducing or eliminating the electric field.
  • bistable electro-optic displays act, to a first approximation, as impulse transducers, so that the final state of a pixel depends not only upon the electric field applied and the time for which this field is applied, but also upon the state of the pixel prior to the application of the electric field.
  • electrophoretic and some other electro-optic displays exhibit bistability, this bistability is not unlimited, and images on the display slowly fade with time, so that if an image is to be maintained for extended periods, the image may have to be refreshed periodically, so as to restore the image to the optical state which it has when first written.
  • images on displays can be refreshed, while reducing the deleterious effects associated with DC imbalanced drive schemes, if the refreshing is effected with short pulses.
  • a further aspect of the present invention relates to dealing with the problem that the aforementioned drive requirements of bistable electro-optic displays render conventional driving methods used for driving LCD's unsuitable for such bistable electro-optic displays.
  • problems may be encountered, and the working lifetime of a display reduced, if the method used to drive the display does not result in zero, or near zero, net time-averaged applied electric field across the electro-optic medium.
  • a drive method which does result in zero net time-averaged applied electric field across the electro-optic medium is conveniently referred to a “direct current balanced” or “DC balanced”.
  • a further aspect of the present invention relates to methods and apparatus for driving electro-optic displays which meet the particular requirements of bistable displays already discussed. Certain methods and apparatus of the present invention are especially intended for producing accurate gray scale rendition in bistable displays.
  • this invention provides a method for addressing a bistable electro-optic display having at least one pixel, the method comprising:
  • the refresh pulse will typically have an impulse not greater than about 20 percent of the impulse of the addressing pulse, desirably not greater than about 10 percent of this impulse, and preferably not greater than about 5 percent of this impulse.
  • typically the difference between the first and second optical states does not exceed about 1 unit of L* (where L* has the usual CIE definition); desirably this difference does not exceed about 0.5 unit of L*, and preferably does not exceed about 0.2 unit of L*.
  • a plurality of refresh pulses may be applied to the pixel at regular intervals.
  • the refresh pulse method after application of the refresh pulse, there is applied to the display a second addressing pulse which drives the pixel to a third optical state different from the first and second optical states, and wherein the impulse applied by the second addressing pulse is the sum of (a) the impulse needed to drive the pixel from the first to the third optical state; and (b) an impulse equal in magnitude but opposite in polarity to the algebraic sum of the refresh pulses applied to the pixel between the first and second addressing pulses.
  • the second addressing pulse may be of constant voltage but variable duration.
  • the second addressing pulse may be a blanking pulse which drives all the pixels of the display to one extreme optical state.
  • the display comprises a plurality of pixels, the first addressing pulse is applied to each pixel so as to drive a first group of pixels white and a second group of pixels black, at least one refresh pulse is applied to each pixel, and there are thereafter applied to the display a first blanking pulse which turns all the pixels black and a second blanking pulse which drives all the pixels white, the two blanking pulses being applied in either order.
  • the impulse applied to each of the first group of pixels during the first blanking pulse is the sum of (a) the impulse needed to drive the pixel from white to black; and (b) an impulse equal in magnitude but opposite in polarity to the algebraic sum of the refresh pulses applied to the pixel between the first addressing pulse and the first blanking pulse.
  • the impulse applied to each of the second group of pixels during the second blanking pulse is the sum of (c) the impulse needed to drive the pixel from black to white; and (d) an impulse equal in magnitude but opposite in polarity to the algebraic sum of the refresh pulses applied to the pixel between the first addressing pulse and the first blanking pulse.
  • the refresh pulse method of the invention may be used with any of the types of electro-optic medium previously described.
  • the display may be a rotating bichromal member or electrochromic display, or an electrophoretic display, desirably an encapsulated electrophoretic display.
  • this invention provides a method for addressing a bistable electro-optic medium which comprises applying to the medium an alternating current pulse having a direct current offset.
  • this invention provides a method for addressing a bistable electro-optic medium which comprises applying to the medium an alternating current pulse, and varying at least one of the duty cycle and the frequency of the pulse to change the optical state of the electro-optic medium following the alternating current pulse.
  • this invention provides a method for addressing a bistable electro-optic display having a plurality of pixels arranged in a plurality of rows and a plurality of columns, a plurality of row electrodes each associated with one of the plurality of rows, a plurality of column electrodes each associated with one of the plurality of columns, and drive means arranged to select each of the row electrodes in turn and to apply to the column electrodes during the selection of any given row electrode voltages chosen so as to address the pixels in the row associated with the selected row electrode and write one row of a desired image on to the display.
  • the method comprises:
  • this invention provides an electro-optic display having a plurality of pixels, at least one of the pixels comprising a plurality of sub-pixels differing from each other in area, the display comprising drive means arranged to change the optical state of the sub-pixels independently of one another.
  • the display desirably at least two of the sub-pixels differ in area by substantially a factor of two.
  • FIG. 1 is a graph showing variations of gray level with time in a display addressed using a direct current pulse with pulse length modulation
  • FIG. 2 is a graph similar to FIG. 1 for a display addressed using a direct current pulse with pulse height modulation
  • FIG. 3 is a graph similar to FIG. 1 for a display addressed using an alternating current pulse with a direct current offset in accordance with the present invention
  • FIG. 4 is a graph similar to FIG. 1 for a display addressed using an alternating current pulse with duty cycle modulation in accordance with the present invention
  • FIG. 5 is a graph showing variations of gray level with time in a display addressed using a double-prepulse slideshow waveform
  • FIG. 6 is a graph showing variations of gray level with time in a display addressed using a single-prepulse slideshow waveform.
  • FIGS. 7A and 7B show possible arrangements of sub-pixels within a single pixel of a display of the present invention.
  • the present invention provides a number of improvements in methods for addressing electro-optic media and displays, and in the construction of such displays.
  • the various aspects of the invention will now be described sequentially, but it should be recognized that a single electro-optic medium or display may make use of more than one aspect of the invention.
  • a single electro-optic display might use AC pulse with DC offset driving and also use refresh pulses.
  • the present invention provides a method for refreshing the image on an electro-optic display by applying to the display a short refresh pulse.
  • a short refresh pulse which is sufficient to change the optical state of that pixel.
  • the impulse applied by the refresh pulse is not greater than about 20 (desirably not greater than 10, and preferably not greater than 5) percent of the impulse applied by the addressing pulse. For example, if a pixel requires an addressing pulse of 15 V for 500 msec, a refresh pulse could be 15 V for 10 msec, with an impulse of 2 percent of that of the addressing pulse.
  • the timing of the refresh pulses in this method should be adjusted to take account of the sensitivity of the human eye to abrupt small changes in optical state.
  • the human eye is relatively tolerant of gradual fading of an image so that, for example, the bistability of an electro-optic medium of often measured as the time necessary for the lightness L* (defined by the usual CIE definition; see, for example, Hunt, R. W. G. Measuring Color, 3rd edition, Fountain Press, guitarist-upon-Thames, England (1998). (ISBN 0 86343 387 1)) to change by 2 units from the maximum for white optical states (or minimum for black states) observed after the conclusion of the addressing pulse.
  • the change in L* caused by a single refresh pulse should be less than about 1 unit of L*, desirably less than about 0.5 unit, and preferably less than about 0.2 unit.
  • refresh pulses in the present method introduces some DC imbalance into the drive scheme during the period in which the refresh pulses are being applied, it does not preclude achieving long term DC balance in the drive scheme, and it has been found that it is the long term rather than short term DC balance which is of major importance in determining the operating life of electro-optic displays.
  • the pixel which has received the refresh pulses may be driven to its opposed optical state by a “switching” or second addressing pulse, and the impulse applied in this switching addressing pulse may be adjusted to provide DC balance (or at least minimal DC imbalance) over the whole period since the first addressing pulse, by adjusting the impulse of this second addressing pulse by an amount substantially equal in magnitude, but opposite in polarity, to the algebraic sum of the refresh pulses applied to the pixel between the two addressing pulses. For example, consider a display which can be switched between white and black optical states by applying an impulse of ⁇ 15 V for 500 msec.
  • a pixel of this display is first switched from black to white by applying an impulse of +15 V for 500 msec, and the white state of the pixel is subsequently maintained by applying at intervals ten refresh pulses each of +15 V for 10 msec. If after these ten refresh pulses, it is desired to return the pixel to its black optical state, this may be achieved by applying an addressing pulse of ⁇ 15 V for 600 (rather than 500) msec, thereby achieving overall DC balance over the whole black-white-black transition of the pixel.
  • This type of adjustment of the switching addressing pulse may be effected when a new image is to be written on the display and it is thus necessary to change the optical states of certain pixels.
  • the adjustment may be carried out during the application of “blanking pulses” to the display.
  • “blanking pulses” As discussed in the aforementioned application Ser. No. 10/065,795, it is often necessary or desirable to apply at regular intervals to an electro-optic display so-called “blanking pulses”; such blanking pulses involve first driving all the pixels of the display to one extreme optical state (for example, a white state), then driving all the pixels to the opposite optical state (for example, black), and then writing the desired image.
  • Effecting the adjustment during blanking pulses has the advantage that all of the pixels may be DC balanced at substantially the same time; the pixels which were black in the prior image (the image present immediately prior to the blanking pulse) can be DC balanced during the blanking pulse which drives all pixels white, while the pixels which were white in the prior image can be DC balanced during the blanking pulse which drives all pixels black, using the technique already described in detail above.
  • effecting the adjustment during blanking pulses can avoid the need to keep track of how many refresh pulses each individual pixel has received since its previous addressing pulse; assuming that black and white pixels are refreshed at the same intervals (as will usually be the case), and that a blanking pulse is inserted at each image transition, each pixel will need the same adjustment (except for polarity) during the blanking pulse, this adjustment being determined by the number of refresh pulses which have been applied to the display since the previous blanking pulse.
  • effecting DC balancing during blanking pulses provides a way to apply the refresh pulse method to electro-optic displays having more than two gray levels, since obviously adjusting the impulse applied during a gray-to-gray transition in such a display may lead to undesirable errors in gray levels.
  • the refresh pulse method of the present invention may be used as an alternative to, or in combination with, additives for increasing the bistability of an electro-optic medium.
  • the present invention may be used with the electrophoretic media described in the aforementioned 2002/0180687, which media have a suspending fluid having dissolved or dispersed therein a polymer which increases the bistability of the medium.
  • This Example uses displays containing an encapsulated dual particle opposite charge type medium comprising a polymer-coated titania white particle and a polymer-coated black particle with an uncolored suspending fluid.
  • the displays were prepared substantially according to “Method B” described in Paragraphs [0061]-[0068] of the aforementioned 2002/0180687.
  • the displays had only limited bistability, the time necessary for the white optical state to change by 2 L* units being only about 15 sec. at ambient temperature.
  • the display was addressed with the standard image, and this image was maintained using the aforementioned refresh pulses for 480 minutes. A series of blanking pulses were then applied, and the cycle of addressing and refresh pulses repeated. No DC balancing pulse was applied at any time. After 83 hours of operation, a series of blanking pulses were applied and then separate areas of the display, which had been white and black respectively in the standard image were tested. The area of the display which had been held white during the testing period is denoted by “480W” in the Table below, while the area which has been held black is denoted by “480D”. Each tested area was driven to its white optical state by a standard 500 msec addressing pulse, and its percentage reflectance value measured; this value is denoted by “w %” in the Table.
  • each tested area was then allowed to stand for 15 sec without any refresh pulses being applied, and the change in L* measured after this 15 second interval; the resultant change in L*, known as the “bright holding difference”, is denoted by “bhdl” in the Table.
  • each tested area was driven to its black optical state by a standard 500 msec addressing pulse, and its percentage reflectance value measured; this value is denoted by “d %” in the Table.
  • Each tested area was then allowed to stand for 15 sec without any refresh pulses being applied, and the change in L* measured after this 15 second interval; the resultant change in L*, known as the “dark holding difference”, is denoted by “dhdl” in the Table.
  • Electrophoretic media used in the refresh pulse method of the present invention may employ the same components and manufacturing techniques as in the aforementioned E Ink and MIT patents and applications, to which the reader is referred for further information.
  • a voltage waveform or drive scheme capable of achieving grayscale in a bistable electro-optic display may hereinafter be called a “grayscale waveform” or “grayscale drive scheme” respectively.
  • grayscale waveform element is used to mean a voltage pulse, or series of voltage pulses, that is capable of producing a change in optical state of an electro-optic display.
  • a grayscale waveform element is itself capable of generating grayscale, and one or more grayscale waveform elements arranged in a particular sequence together form a grayscale drive waveform.
  • a grayscale drive waveform is capable of switching a pixel of a display from one gray state to another.
  • a sequence of one or more drive waveforms makes up a drive scheme, which is capable of displaying any series of grayscale images on a display.
  • grayscale addressing schemes will primarily be discussed with reference to encapsulated particle-based electrophoretic media, but it is considered that the necessary modifications of such schemes to allow for the properties of other types of bistable electro-optic media will readily be apparent to those skilled in the technology of such media.
  • the inset illustrates the DC pulse length modulated waveform elements used to produce the grayscale transitions in an encapsulated electrophoretic medium shown in the main part of the Figure.
  • the displays used in this and subsequent experiments described below were prepared substantially according to “Method B” described in Paragraphs [0061]-[0068] of the aforementioned 2002/0180687.)
  • the three pulses used were 15 V for 200, 400 and 600 msec respectively, and the three curves produced are labelled accordingly; note that the time scale in the inset is not the same as that in the main Figure.
  • the pulse height was fixed, while the duration of the pulse was varied for different changes in reflectivity.
  • FIG. 1 the reflectivity of a pixel, whose reflective state was changed from black to different levels of gray upon application of these voltage pulses, is plotted against time; it will be seen that longer pulse lengths yielded greater changes in reflectivity.
  • the display tested responded immediately to the end of the applied voltage pulse, and its optical state ceased to evolve. On the microscopic level, it may be presumed that the electrophoretic particles instantly stop in transit from one electrode to the other and remain suspended at an intermediate position within the capsule.
  • An advantage of a DC grayscale drive pulse with pulse length modulation is the speed with which the desired gray state is achieved.
  • the inset illustrates the DC pulse height modulated waveform elements used to produce the grayscale transitions in an encapsulated electrophoretic medium shown in the main part of the Figure.
  • the voltage pulse length is fixed at the length of time required to completely switch the medium at the maximum voltage level.
  • the three pulses used were 5, 10 and 15 V for 500 msec respectively, and the three curves produced are labelled accordingly; note that the time scale in the inset is not the same as that in the main Figure.
  • the pulse length was fixed, while the height of the pulse was varied for different changes in reflectivity.
  • the reflectivity of a pixel, whose reflective state was changed from black to different levels of gray upon application of these voltage pulses is plotted against time; it will be seen that greater pulse heights yielded greater changes in reflectivity.
  • An advantage of a DC grayscale drive pulse with pulse height modulation is accurate control of the gray state achieved.
  • Grayscale driving of the aforementioned encapsulated electrophoretic medium has been effected with oscillating (AC) electric fields; the switching mechanism with such AC fields is presumed to be entirely different from that effected in the DC driving of the same medium discussed above.
  • FIG. 3 of the accompanying drawings the inset illustrates the AC pulse with DC offset modulation waveform elements used to produce the grayscale transitions in an encapsulated electrophoretic medium shown in the main part of the Figure.
  • the frequency of the AC component approximately 10 Hz
  • the electrophoretic particles oscillate in the suspending fluid and this oscillation is observed motion as a cyclic variation in reflectivity, superimposed upon the overall change in reflectivity, as is readily seen on the left hand side of FIG. 3 .
  • the DC offset was applied.
  • the reflectivity approaches a constant value after the waveform has been applied for some time. It appears that there must be a restoring force that opposes the force on the particles due to the DC offset voltage, otherwise, the particles would continue to flow to the cell wall. This restoring force may be due to the motion of fluid in between the capsule wall and the particles and/or to the interaction of the particles directly with the cell wall.
  • the stability of the optical state after the voltage is released appears consistent with that of other waveform elements.
  • AC waveform elements are the ability to reach a particular reflectivity state by specifying the parameters of the waveform element, while DC waveform elements enable only a change in reflectivity.
  • An advantage of an AC waveform element with DC offset over other AC waveform elements is that precise timing of the addressing pulse is not required.
  • the inset illustrates the AC pulses with duty cycle modulation used to produce the grayscale transitions shown in the main part of the Figure.
  • the voltage is set to a maximum value, and the duty cycle (the percentage of time that the voltage is in the positive or negative direction) determines the reflectivity.
  • the three duty cycles used were 50, 47 and 40 percent, as indicated in FIG. 4 .
  • the time scale used in the inset is not the same as that in the main Figure.
  • the reflectivity of a pixel, whose reflective state was changed from black to different levels of gray upon application of the voltage pulses, is plotted against time.
  • An advantage of an AC waveform with duty cycle modulation is that voltage modulation is not required.
  • AC grayscale switching is to apply to an electro-optic medium an AC field which causes the optical state of the medium to oscillate and then to terminate the AC field in mid-cycle at the point having the desired reflectivity.
  • the voltage may be set at a maximum value and the AC frequency varied in order to achieve a greater or lesser reflectivity range.
  • the frequency determines the amplitude of the oscillation in reflectivity.
  • the electrophoretic particles When such an approach is applied to an encapsulated particle-based electrophoretic medium, the electrophoretic particles respond to the AC field by oscillating around their initial positions. Since the reflectivity typically does not reach either the extreme black or white optical state, interactions with the cell wall are minimized and the response of the reflectivity is relatively linear with the applied voltage.
  • An advantage of AC pulses with frequency modulation is that voltage modulation is not required.
  • pulse width modulation and AC pulses are used to achieve an intermediate gray state in an electro-optic display which otherwise would be capable of achieving only black and white states.
  • the ability to achieve gray scale is highly desirable in electro-optic displays.
  • providing a large number of gray levels requires either pulse width modulation with a high frame rate driver (the high frame rate being needed to “slice” the pulse width into a large number of intervals, thereby enabling pulse width and hence gray scale to be controlled very accurately) or a driver capable of voltage modulation.
  • Either type of driver is substantially more costly than the simple tri-level drivers, which enable individual pixels of a display to be set only to +V, ⁇ V and 0 potential (where V is an arbitrary operating potential) relative to the potential of a common front plane electrode, and which are commonly used to drive displays capable of only black and white states.
  • This invention provides a drive scheme which enables a tri-level driver to produce a gray level intermediate the black and white levels of a bistable electro-optic display.
  • the drive scheme is most easily appreciated from the following Table 2, which shows the voltage applied during the successive frames of various types of transitions in such a display of the present invention: TABLE 2 0 1 2 3 4 5 6 . . . N ⁇ 1 N white to black +V +V +V +V +V +V +V +V +V +V +V +V +V +V +V +V +V +V +V +V +V +V +V +V +V +V +V +V +V . . . +V black to white ⁇ V ⁇ V ⁇ V ⁇ V ⁇ V ⁇ V ⁇ V . . . ⁇ V ⁇ V white to gray +V +V +V +V +V ⁇ V +V ⁇ V . . .
  • the transitions from black to white or vice versa are the same as in a binary (black/white only) display.
  • the transitions to gray have two parts.
  • the first part is a square wave pulse (i.e., a plurality of frames at the same potential) of the proper polarity and length to bring the reflectivity of the electro-optic medium as close as possible to the desired middle gray lightness.
  • the accuracy possible with this step will be limited by the frame rate of the display.
  • the second part of the addressing pulse consists of an equal number of positive and negative voltage pulses, each one frame in width.
  • this invention provides a method to produce a single gray level in an otherwise binary electro-optic display using only a simple tri-level driver rather than without the use of a complex and costly voltage modulated driver.
  • this invention provides a collection of two-dimensional transition matrices, wherein each element in the matrix specifies how to get from an initial optical state (denoted “the row index” herein, although obviously the allocation of the initial optical states to rows is arbitrary) to a final optical state (denoted “the column index” herein).
  • Each element of this matrix is constructed from a series of waveform elements (as defined above), and in general, for an n-bit grayscale display, this matrix will contain 2 (2N) elements.
  • the matrices of the present invention take account of such considerations as the need for DC balancing of the drive scheme (as discussed above), minimizing “memory” effects in certain electro-optic media (i.e., effects whereby the result of applying a particular pulse to a pixel depends not only upon the current state of the pixel but also upon certain prior states), thereby producing uniform optical states and maximizing the switching speed of the display, while working within the constraints of an active matrix drive scheme.
  • the present invention also provides a method for determining the optimal values of each term of the elements in such a matrix for any specific electro-optic medium. For further discussion of such matrices and their use in driving electro-optic displays, the reader is referred to the aforementioned copending application Ser. No. 10/065,795.
  • pulse width modulation PWM
  • pulse height modulation or the various hybrid types of AC modulation discussed above, and various different types of modulation may be employed within a single waveform, for example, pulse width modulation for all but the last section of the pulse, followed by voltage modulation on the last section of the pulse.
  • the first two waveforms of the present invention described below are “slide show” waveforms, which return from one gray state to the black state before addressing out to the next gray state. Such waveforms are most compatible with a display update scheme where the entire screen blanks at once, as in a slide projector.
  • a pixel of the electro-optic medium is initially driven (as indicated at 100 ) from black to an initial (first) gray state using a partial pulse.
  • the pixel is first driven (at 102 ) from the first gray state to white, and then (at 104 ) from white to black.
  • the proper pulse to reach the second gray state is applied at 106 .
  • This waveform requires a maximum of three times the switching time of the medium (i.e., the time necessary for a single pixel to switch from its black optical state to its white optical state or vice versa) to effect a transition between any two arbitrary gray states, and is therefore referred to as a 3 ⁇ waveform.
  • a pixel of the electro-optic medium is initially driven (as indicated at 110 ) from black to an initial (first) gray state using a partial pulse, in the same way as in the double-prepulse waveform discussed in Section 6 above.
  • the pixel is first driven (at 112 ) from the first gray state to black, then the proper pulse to reach the second gray state is applied at 114 .
  • the pixel will again be returned to black at 116 .
  • This type of waveform preserves DC balance of the overall waveform, since the impulses applied at 112 and 116 are equal (except for polarity) to the impulses applied at 110 and 114 respectively.
  • This waveform requires a maximum of twice the switching time of the medium to effect a transition between any two arbitrary gray states, and is therefore referred to as a 2 ⁇ waveform.
  • a display may be updated by addressing it directly from one gray state to another without passing through a black or white state. Since there are no obvious artifacts (i.e., black and/or white “flashes”) associated with such a transition, it may be referred to as “gray-to-gray” addressing.
  • gray-to-gray waveform There are two main forms of gray-to-gray waveform, namely DC-balanced and DC-imbalanced.
  • a DC-balanced gray-to-gray waveform the transition between any two gray states is effected by applying a modulated pulse of the precise length necessary to shift between the two states.
  • the electro-optic medium does not pass through any intermediate black or white states. Since the maximum pulse length is equal to the addressing time of the ink, such a waveform may be referred to as a 1 ⁇ waveform.
  • n ⁇ 1 free parameters available in the optimization of the transition matrix associated with any specific waveform. This results in a highly over-constrained system. For example, all transitions are required to be equal and opposite in impulse to the reverse transition (i.e. 2-3 must be the same as 3-2, except for polarity).
  • a DC-imbalanced gray-to-gray waveform is fundamentally the same as a DC-balanced one, except that the pulse lengths are no longer constrained by the restriction of DC balancing.
  • each of the 2 (2N) entries in the transition matrix can vary independently of all the others.
  • Another aspect of the present invention relates to improving the performance of an active matrix bistable electro-optic display by selective driving of the rows of the display.
  • the continuous refreshment is effected by using a row driver to turn on the gates of the transistors associated with one row of pixels of the display, placing on column drivers (connected to the source electrodes of the transistors in each column of the display) the potentials needed to write to the pixels in the selected row the relevant portion of the desired image on the display, and thus writing the selected row of the display.
  • the row driver selects the next row of the display and the process is repeated, with the rows thus being refreshed cyclically.
  • the assignment of the row drivers to gate electrodes and the column drivers to source electrodes is conventional but essentially arbitrary, and could of course be reversed if desired.
  • bistable electro-optic displays do not need continuous refreshing, and indeed such continuous refreshing is undesirable, since it unnecessarily increases the energy consumption of the display. Furthermore, during such refreshing, the gate (row) lines may deliver capacitative voltage spikes to pixel electrodes, and any driver voltage errors or uncompensated gate feedthrough bias errors can accumulate; all these factors can result in undesirable shifts in the optical states of the pixels of the display. Accordingly, in bistable electro-optic displays it is desirable to provide some means for updating a portion of an image without the need to rewrite the whole image on the display, and one aspect of this invention relates to a bistable electro-optic display provided with such “partial updating” means. According to the present invention, this is done by comparing successive images to be written to the display, identifying the rows which differ in the two images, and addressing only the rows thus identified.
  • a display controller (cf. the aforementioned copending application Ser. No. 10/065,795) examines all of the desired pixel electrode output voltages. If all of the output voltages for that line are equal to the potential V com of the common front electrode of the display (i.e., if no pixel in that row needs to be rewritten), then the controller outputs a synchronizing (V sync ) pulse without loading data values into the column drivers, and without issuing a corresponding output enable (OE) command. The net effect of this is that the token bit for the row drivers is passed to the next row of the display without activating the current row. Data is only loaded into the column drivers, and output enable is only asserted, for rows where at least one pixel needs to be rewritten.
  • This invention gives two distinct types of advantages. Firstly, many sources of spurious voltage are eliminated for pixels that are not rewritten. There is no capacitative gate spike for these pixels, and errors in the column driver voltage will not be passed on to a pixel in frames where it is not addressed. Because of the relatively lower resistivity of many electro-optic media, especially electrophoretic media, as compared with liquid crystals, the pixel electrode will tend to relax to the actual front plane voltage, thus maintaining the hold state of the electro-optic medium. Secondly, power consumption of the display is minimized. For every row that is not rewritten, the corresponding gate line does not have to be charged. In addition, when data is not loaded into the column drivers of the display, the additional power consumption of moving that data across the display interface is also eliminated.
  • the aspects of the present invention previously discussed relate to the waveforms used to drive electro-optic displays. However, the behavior of such displays can also be changed by varying the structure of the backplane, and this aspect of the invention relates to dividing one or more pixel, and preferably each pixel, of a display into a plurality of sub-pixels having differing areas.
  • grayscale in an electro-optic display.
  • This gray scale may be achieved either by driving a pixel of the display to a gray state intermediate its two extreme states.
  • the medium is not capable of achieving the desired number of intermediate states, or if the display is being driven by drivers which are not capable of providing the desired number of intermediate states, other methods must be used to achieve the desired number of states, and this aspect of the invention relates to the use of spatial dithering for this purpose.
  • a display may be divided into a plurality of “logical” pixels, each of which is capable of displaying the desired number of gray or other optical states.
  • logical pixels each of which comprises three sub-pixels of primary colors, for example red, green and blue; see, for example, the aforementioned 2002/0180688.
  • full color logical pixels each of which comprises three sub-pixels of primary colors, for example red, green and blue; see, for example, the aforementioned 2002/0180688.
  • a logical pixel comprising four independently controllable sub-pixels of equal area could be used to provide two-bit gray scale.
  • the number of sub-pixels becomes inconveniently great, since the required number of sub-pixels doubles for each one-bit increase in gray scale.
  • the present invention provides an electro-optic display having at least one pixel which comprises a plurality of sub-pixels, these sub-pixels being of differing areas.
  • at least two sub-pixels differ in area by substantially a factor of two.
  • a logical pixel might have sub-pixels with areas of 1X, 2X and 4X, where X is an arbitrary area.
  • a logical pixel of this type is illustrated schematically in FIG. 7A of the accompanying drawings. This logical pixel achieves three-bit grayscale using only three electrodes, whereas achieving the same three-bit grayscale with sub-pixels of equal area would require eight sub-pixels.
  • each sub-pixel When driven, each sub-pixel reflects or transmits a portion of the incoming light, and the fractional amount is dictated by the area of the sub-pixel. If the reflectance/transmission is averaged over the area of the logical pixel, then a binary weighting of driven area is achieved, and hence spatially dithered grayscale.
  • the areas of the sub-pixels are arbitrary.
  • the ones shown in FIG. 7A are weighed by reflectance. If one were to use a non-linear weighting (as would be appropriate for equal steps in L* or a gamma corrected grayscale spacing), the areas would be changed accordingly.
  • Another approach to dealing with the problems of sub-pixel visibility and/or visible patterning is to randomly orient the sub-pixels. For example, in an array of pixels each of which has the sub-pixel arrangement shown in FIG. 7A , individual pixels could have, at random, each of the four possible orientations of the arrangement shown in FIG. 7A . Such “randomization” of the sub-pixels helps to break up patterns and render them less noticeable to an observer.
  • FIGS. 7A and 7B produce three-bit grayscale, it will be appreciated that the present invention can produce any number of bits of gray scale simply by adding additional sub-pixels.
  • the electro-optic medium itself does not need to be capable of gray scale; essentially the display can be a black/white display, and sub-pixels turned on and off to produce gray scale.
  • the necessary control of the sub-pixels can be achieved by providing additional column drivers for the same number of rows, as in color sub-pixel arrays. This reduces demands upon the electro-optic medium used; for example, one does not need to worry about possible drift of gray levels of the medium over its operating lifetime.
  • TFT thin film transistor
  • the voltages of the pixel electrodes on the display backplane are varied in order to impose desired voltages across pixels.
  • the top plane is typically held at a particular voltage deemed advantageous for addressing the pixels. For example, if the data line voltage supplied to the pixel electrodes varies between zero volts and a voltage V 0 , the top plane may be held at V 0 /2 in order to permit voltage drops across the pixel to be as large as V 0 /2 in both directions.
  • the voltage of the top plane may be varied to enhance the addressing of the electro-optic medium.
  • the top plane voltage could be held at zero volts in order to permit the total pixel voltage drop (top plane minus pixel voltage) to be as low at ⁇ V 0 . Raising the top plane up to V 0 permits a pixel voltage drop as large as V 0 . These larger voltage drops permit faster addressing of the electro-optic medium.
  • the top plane voltage may be able to set the top plane voltage not only at voltages zero and V 0 , but to other voltages as well.
  • this invention provides an electro-optic display having a storage capacitor formed between a pixel electrode and a (second) electrode that has a voltage that can be varied independently from the select lines of the display.
  • the second electrode follows the top plane voltage, that is, its voltage differs from the top plane only by a time-independent constant.
  • Another aspect of the present invention relates to reducing or eliminating unwanted switching of the electro-optic medium by select and data lines.
  • select and data lines are essential elements of an active matrix panel in that they provide the voltages required for charging pixel electrodes to desired values.
  • the select and data lines can have the unwanted effect of switching the electro-optic medium adjacent the data lines.
  • the undesirable optical artifacts caused by such switching can be eliminated by using a black mask to hide the regions switched by the data and/or select lines from a viewer.
  • providing such a black mask requires registration of the front plane of the display with its back plane and a reduction in the fraction of the electro-optic medium that is exposed to the viewer. The result is a display darker and lower in contrast than one could achieve without the black mask.
  • the need for a black mask is avoided by making the data lines to have a small lateral extent in one direction so that they do not appreciably address the adjacent electro-optic medium during normal display operation. This obviates the need for a black mask.
  • a related aspect of the present invention relates to the use of passivated electrodes and modification of the drive scheme used to drive the electro-optic medium.
  • An impulse-driven electro-optic medium can be electronically addressed when it is in a thin film form between two electrodes. Generally, the electrodes make contact with the electro-optic medium. However, it is also possible to address the medium even when a dielectric material with a long electronic relaxation time exists between one or both electrodes and the medium. Passivation of one or both electrodes may be desirable to avoid adverse chemical or electrochemical interactions at the backplane or front plane of a display device; see the aforementioned WO 00/38001. Although the ability to sustain a voltage across the electro-optic medium is greatly reduced by the presence of a dielectric layer, a voltage impulse can still be applied to the medium and the medium can be addressed through these voltage impulses if the dielectric layer is properly engineered.
  • the optical state of an electro-optic medium is of course achieved by changing the voltage on a pixel electrode. This voltage change results in a voltage across the electro-optic medium that decays as charge leaks through the medium. If an external dielectric layer (i.e., a dielectric layer between the medium and one electrode) is sufficiently thin and the electro-optic medium is sufficiently resistive, the voltage impulse across the medium will be sufficient to cause a desirable shift in the optical state of the medium. Electronic addressing of an electro-optic medium through a dielectric layer is therefore possible.
  • the addressing scheme is different, however, from addressing an electro-optic medium with electrodes in direct contact with the medium since, in the latter case, the medium is addressed by applying voltages across the pixel, whereas, in the former case, addressing is achieved by causing a change in the pixel voltage. At every change, a voltage impulse is experienced by the electro-optic medium.
  • this invention provides drive schemes for reducing cross-talk in active matrix electro-optic displays.
  • Inter-pixel cross-talk where addressing one pixel affects the optical state of other pixels, is undesirable but has many causes.
  • One cause is the finite current flow through transistors in the off state. Bringing a data line to a voltage intended for charging one pixel can charge up transistors in unselected rows because of off state current leakage.
  • a solution is to use transistors with a low off-state current.
  • Another source of cross talk is current leakage between neighboring pixels. Current can leak through elements of the backplane or through the electro-optic medium in contact with the backplane.
  • a solution to such cross talk is to design the backplane with a large insulating gap between the pixel electrodes. A larger gap will result in smaller leakage currents.
  • electro-optic medium for use in the present invention is an encapsulated particle-based electrophoretic medium.
  • electrophoretic media used in the methods and apparatus of the present invention may employ the same components and manufacturing techniques as in the aforementioned E Ink and MIT patents and applications, to which the reader is referred for further information.

Abstract

A method for addressing a bistable electro-optic display having at least one pixel comprises applying an addressing pulse to drive the pixel to a first optical state; leaving the pixel undriven for a period of time, thereby permitting the pixel to assume a second optical state different from the first optical state; and applying to the pixel a refresh pulse which substantially restores the pixel to the first optical state, the refresh pulse being short relative to the addressing pulse.

Description

    REFERENCE TO RELATED APPLICATIONS
  • This application is a divisional of copending application Ser. No. 10/249,973, filed May 23, 2003 (Publication No. 2005/0270261), which is a continuation-in-part of application Ser. No. 10/065,795, filed Nov. 20, 2002 (now U.S. Pat. No. 7,012,600), which is itself a continuation-in-part of application Ser. No. 09/561,424, filed Apr. 28, 2000 (now U.S. Pat. No. 6,531,997), which is itself a continuation-in-part of copending application Ser. No. 09/520,743, filed Mar. 8, 2000 (now U.S. Pat. No. 6,504,524). Application Ser. No. 10/065,795 also claims priority from the following Provisional Applications: (a) Ser. No. 60/319,007, filed Nov. 20, 2001; (b) Ser. No. 60/319,010, filed Nov. 21, 2001; (c) Ser. No. 60/319,034, filed Dec. 18, 2001; (d) Ser. No. 60/319,037, filed Dec. 20, 2001; and (e) Ser. No. 60/319,040, filed Dec. 21, 2001. Application Ser. No. 10/249,973 also claims priority from copending Application Ser. No. 60/319,315, filed Jun. 13, 2002 and copending Application Ser. No. 60/319,321, filed Jun. 18, 2002. Application Ser. No. 09/561,424 also claims priority from Application Ser. No. 60/131,790, filed Apr. 30, 1999.
  • This application is also related to copending application Ser. No. 10/063,236, filed Apr. 2, 2002 (Publication No. 2002/0180687). The entire contents of the aforementioned applications, and of all U.S. patents and published applications mentioned below, are herein incorporated by reference.
  • BACKGROUND OF INVENTION
  • This invention relates to methods and apparatus for driving electro-optic displays, particularly bistable electro-optic displays. The methods and apparatus of the present invention are especially, though not exclusively, intended for use in driving bistable electrophoretic displays.
  • The term “electro-optic” as applied to a material or a display, is used herein in its conventional meaning in the imaging art to refer to a material having first and second display states differing in at least one optical property, the material being changed from its first to its second display state by application of an electric field to the material. Although the optical property is typically color perceptible to the human eye, it may be another optical property, such as optical transmission, reflectance, luminescence or, in the case of displays intended for machine reading, pseudo-color in the sense of a change in reflectance of electromagnetic wavelengths outside the visible range.
  • The term “gray state” is used herein in its conventional meaning in the imaging art to refer to a state intermediate two extreme optical states of a pixel, and does not necessarily imply a black-white transition between these two extreme states. For example, several of the patents and published applications referred to below describe electrophoretic displays in which the extreme states are white and deep blue, so that an intermediate “gray state” would actually be pale blue. Indeed, as already mentioned the transition between the two extreme states may not be a color change at all.
  • The terms “bistable” and “bistability” are used herein in their conventional meaning in the art to refer to displays comprising display elements having first and second display states differing in at least one optical property, and such that after any given element has been driven, by means of an addressing pulse of finite duration, to assume either its first or second display state, after the addressing pulse has terminated, that state will persist for at least several times, for example at least four times, the minimum duration of the addressing pulse required to change the state of the display element. It is shown in the aforementioned copending application Ser. No. 10/063,236 that some particle-based electrophoretic displays capable of gray scale are stable not only in their extreme black and white states but also in their intermediate gray states, and the same is true of some other types of electro-optic displays. This type of display is properly called “multi-stable” rather than bistable, although for convenience the term “bistable” may be used herein to cover both bistable and multi-stable displays.
  • The term “impulse” is used herein in its conventional meaning of the integral of voltage with respect to time. However, some bistable electro-optic media act as charge transducers, and with such media an alternative definition of impulse, namely the integral of current over time (which is equal to the total charge applied) may be used. The appropriate definition of impulse should be used, depending on whether the medium acts as a voltage-time impulse transducer or a charge impulse transducer.
  • Several types of bistable electro-optic displays are known. One type of electro-optic display is a rotating bichromal member type as described, for example, in U.S. Pat. Nos. 5,808,783; 5,777,782; 5,760,761; 6,054,071 6,055,091; 6,097,531; 6,128,124; 6,137,467; and 6,147,791 (although this type of display is often referred to as a “rotating bichromal ball” display, the term “rotating bichromal member” is preferred as more accurate since in some of the patents mentioned above the rotating members are not spherical). Such a display uses a large number of small bodies (typically spherical or cylindrical) which have two or more sections with differing optical characteristics, and an internal dipole. These bodies are suspended within liquid-filled vacuoles within a matrix, the vacuoles being filled with liquid so that the bodies are free to rotate. The appearance of the display is changed to applying an electric field thereto, thus rotating the bodies to various positions and varying which of the sections of the bodies is seen through a viewing surface.
  • Another type of electro-optic medium uses an electrochromic medium, for example an electrochromic medium in the form of a nanochromic film comprising an electrode formed at least in part from a semi-conducting metal oxide and a plurality of dye molecules capable of reversible color change attached to the electrode; see, for example O'Regan, B., et al., Nature 1991, 353, 737; and Wood, D., Information Display, 18(3), 24 (March 2002). See also Bach, U., et al., Adv. Mater., 2002, 14(11), 845. Nanochromic films of this type are also described, for example, in U.S. Pat. No. 6,301,038, International Application Publication No. WO 01/27690, and in copending application Ser. No. 10/249,128 filed Mar. 18, 2003 (now U.S. Pat. No. 6,950,220).
  • Another type of electro-optic display, which has been the subject of intense research and development for a number of years, is the particle-based electrophoretic display, in which a plurality of charged particles move through a suspending fluid under the influence of an electric field. Electrophoretic displays can have attributes of good brightness and contrast, wide viewing angles, state bistability, and low power consumption when compared with liquid crystal displays. Nevertheless, problems with the long-term image quality of these displays have prevented their widespread usage. For example, particles that make up electrophoretic displays tend to settle, resulting in inadequate service-life for these displays.
  • Numerous patents and applications assigned to or in the names of the Massachusetts Institute of Technology (MIT) and E Ink Corporation have recently been published describing encapsulated electrophoretic media. Such encapsulated media comprise numerous small capsules, each of which itself comprises an internal phase containing electrophoretically-mobile particles suspended in a liquid suspension medium, and a capsule wall surrounding the internal phase. Typically, the capsules are themselves held within a polymeric binder to form a coherent layer positioned between two electrodes. Encapsulated media of this type are described, for example, in U.S. Pat. Nos. 5,930,026; 5,961,804; 6,017,584; 6,067,185; 6,118,426; 6,120,588; 6,120,839; 6,124,851; 6,130,773; 6,130,774; 6,172,798; 6,177,921; 6,232,950; 6,249,271; 6,252,564; 6,262,706; 6,262,833; 6,300,932; 6,312,304; 6,312,971; 6,323,989; 6,327,072; 6,376,828; 6,377,387; 6,392,785; 6,392,786; 6,413,790; 6,422,687; 6,445,374; 6,445,489; 6,459,418; 6,473,072; 6,480,182; 6,498,114; 6,504,524; 6,506,438; 6,512,354; 6,515,649; 6,518,949; 6,521,489; 6,531,997; 6,535,197; 6,538,801; and 6,545,291; and U.S. Patent Applications Publication Nos. 2002/0019081; 2002/0021270; 2002/0053900; 2002/0060321; 2002/0063661; 2002/0063677; 2002/0090980; 2002/0106847; 2002/0113770; 2002/0130832; 2002/0131147; 2002/0145792; 2002/0154382, 2002/0171910; 2002/0180687; 2002/0180688; 2002/0185378; 2003/0011560; 2003/0011867; 2003/0011868; 2003/0020844; 2003/0025855; 2003/0034949; 2003/0038755; and 2003/0053189; and International Applications Publication Nos. WO 99/67678; WO 00/05704; WO 00/20922; WO 00/26761; WO 00/38000; WO 00/38001; WO 00/36560; WO 00/67110; WO 00/67327; WO 01/07961; and WO 01/08241.
  • Many of the aforementioned patents and applications recognize that the walls surrounding the discrete microcapsules in an encapsulated electrophoretic medium could be replaced by a continuous phase, thus producing a so-called polymer-dispersed electrophoretic display in which the electrophoretic medium comprises a plurality of discrete droplets of an electrophoretic fluid and a continuous phase of a polymeric material, and that the discrete droplets of electrophoretic fluid within such a polymer-dispersed electrophoretic display may be regarded as capsules or microcapsules even though no discrete capsule membrane is associated with each individual droplet; see for example, the aforementioned 2002/0131147. Accordingly, for purposes of the present application, such polymer-dispersed electrophoretic media are regarded as sub-species of encapsulated electrophoretic media.
  • An encapsulated electrophoretic display typically does not suffer from the clustering and settling failure mode of traditional electrophoretic devices and provides further advantages, such as the ability to print or coat the display on a wide variety of flexible and rigid substrates. (Use of the word “printing” is intended to include all forms of printing and coating, including, but without limitation: pre-metered coatings such as patch die coating, slot or extrusion coating, slide or cascade coating, curtain coating; roll coating such as knife over roll coating, forward and reverse roll coating; gravure coating; dip coating; spray coating; meniscus coating; spin coating; brush coating; air knife coating; silk screen printing processes; electrostatic printing processes; thermal printing processes; ink jet printing processes; and other similar techniques.) Thus, the resulting display can be flexible. Further, because the display medium can be printed (using a variety of methods), the display itself can be made inexpensively.
  • A related type of electrophoretic display is a so-called “microcell electrophoretic display”. In a microcell electrophoretic display, the charged particles and the suspending fluid are not encapsulated within microcapsules but instead are retained within a plurality of cavities formed within a carrier medium, typically a polymeric film. See, for example, International Applications Publication No. WO 02/01281, and published US Application No. 2002-0075556, both assigned to Sipix Imaging, Inc.
  • Although electrophoretic displays are often opaque (since the particles substantially block transmission of visible light through the display) and operate in a reflective mode, electrophoretic displays can be made to operate in a so-called “shutter mode” in which the particles are arranged to move laterally within the display so that the display has one display state which is substantially opaque and one which is light-transmissive. See, for example, the aforementioned U.S. Pat. Nos. 6,130,774 and 6,172,798, and U.S. Pat. Nos. 5,872,552; 6,144,361; 6,271,823; 6,225,971; and 6,184,856. Dielectrophoretic displays, which are similar to electrophoretic displays but rely upon variations in electric field strength, can operate in a similar mode; see U.S. Pat. No. 4,418,346. Other types of electro-optic displays may also be capable of operating in shutter mode.
  • The bistable or multi-stable behavior of particle-based electrophoretic displays, and other electro-optic displays displaying similar behavior, is in marked contrast to that of conventional liquid crystal (“LC”) displays. Twisted nematic liquid crystals act are not bi- or multi-stable but act as voltage transducers, so that applying a given electric field to a pixel of such a display produces a specific gray level at the pixel, regardless of the gray level previously present at the pixel. Furthermore, LC displays are only driven in one direction (from non-transmissive or “dark’ to transmissive or “light”), the reverse transition from a lighter state to a darker one being effected by reducing or eliminating the electric field. Finally, the gray level of a pixel of an LC display is not sensitive to the polarity of the electric field, only to its magnitude, and indeed for technical reasons commercial LC displays usually reverse the polarity of the driving field at frequent intervals. In contrast, bistable electro-optic displays act, to a first approximation, as impulse transducers, so that the final state of a pixel depends not only upon the electric field applied and the time for which this field is applied, but also upon the state of the pixel prior to the application of the electric field.
  • Although as already indicated, electrophoretic and some other electro-optic displays exhibit bistability, this bistability is not unlimited, and images on the display slowly fade with time, so that if an image is to be maintained for extended periods, the image may have to be refreshed periodically, so as to restore the image to the optical state which it has when first written.
  • However, such refreshing of the image may give rise to its own problems. As discussed in the aforementioned U.S. Pat. Nos. 6,531,997 and 6,504,524, problems may be encountered, and the working lifetime of a display reduced, if the method used to drive the display does not result in zero, or near zero, net time-averaged applied electric field across the electro-optic medium. A drive method which does result in zero net time-averaged applied electric field across the electro-optic medium is conveniently referred to a “direct current balanced” or “DC balanced”. If an image is to be maintained for extended periods by applying refreshing pulses, these pulses need to be of the same polarity as the addressing pulse originally used to drive the relevant pixel of the display to the optical state being maintained, which results in a DC imbalanced drive scheme.
  • According to one aspect of the present invention, it has been found that images on displays can be refreshed, while reducing the deleterious effects associated with DC imbalanced drive schemes, if the refreshing is effected with short pulses.
  • A further aspect of the present invention relates to dealing with the problem that the aforementioned drive requirements of bistable electro-optic displays render conventional driving methods used for driving LCD's unsuitable for such bistable electro-optic displays. Furthermore, as discussed in the aforementioned U.S. Pat. Nos. 6,531,997 and 6,504,524, problems may be encountered, and the working lifetime of a display reduced, if the method used to drive the display does not result in zero, or near zero, net time-averaged applied electric field across the electro-optic medium. A drive method which does result in zero net time-averaged applied electric field across the electro-optic medium is conveniently referred to a “direct current balanced” or “DC balanced”. Similar problems could be encountered with LCD's, but the insensitivity of such displays to the polarity of the applied electric field, and the consequent ability to reverse polarity at will, renders DC balance problems unimportant in LCD's. However, the need for DC balance is an important consideration in devising drive schemes for bistable electro-optic displays in which the electro-optic medium is sensitive to the polarity of the applied electric field.
  • Accordingly, a further aspect of the present invention relates to methods and apparatus for driving electro-optic displays which meet the particular requirements of bistable displays already discussed. Certain methods and apparatus of the present invention are especially intended for producing accurate gray scale rendition in bistable displays.
  • SUMMARY OF THE INVENTION
  • Accordingly, in one aspect, this invention provides a method for addressing a bistable electro-optic display having at least one pixel, the method comprising:
  • applying an addressing pulse to drive the pixel to a first optical state;
  • leaving the pixel undriven for a period of time, thereby permitting the pixel to assume a second optical state different from the first optical state; and
  • applying to the pixel a refresh pulse which substantially restores the pixel to the first optical state, the refresh pulse being short relative to the addressing pulse.
  • This aspect of the invention may hereinafter for convenience be referred to as the “refresh pulse” method of the invention.
  • In this refresh pulse method, the refresh pulse will typically have an impulse not greater than about 20 percent of the impulse of the addressing pulse, desirably not greater than about 10 percent of this impulse, and preferably not greater than about 5 percent of this impulse. For reasons explained below, typically the difference between the first and second optical states does not exceed about 1 unit of L* (where L* has the usual CIE definition); desirably this difference does not exceed about 0.5 unit of L*, and preferably does not exceed about 0.2 unit of L*. A plurality of refresh pulses may be applied to the pixel at regular intervals.
  • In one form of the refresh pulse method, after application of the refresh pulse, there is applied to the display a second addressing pulse which drives the pixel to a third optical state different from the first and second optical states, and wherein the impulse applied by the second addressing pulse is the sum of (a) the impulse needed to drive the pixel from the first to the third optical state; and (b) an impulse equal in magnitude but opposite in polarity to the algebraic sum of the refresh pulses applied to the pixel between the first and second addressing pulses. The second addressing pulse may be of constant voltage but variable duration. In a display comprising a plurality of pixels, the second addressing pulse may be a blanking pulse which drives all the pixels of the display to one extreme optical state. In one preferred form of such a “blanking pulse/refresh pulse” process, the display comprises a plurality of pixels, the first addressing pulse is applied to each pixel so as to drive a first group of pixels white and a second group of pixels black, at least one refresh pulse is applied to each pixel, and there are thereafter applied to the display a first blanking pulse which turns all the pixels black and a second blanking pulse which drives all the pixels white, the two blanking pulses being applied in either order. The impulse applied to each of the first group of pixels during the first blanking pulse is the sum of (a) the impulse needed to drive the pixel from white to black; and (b) an impulse equal in magnitude but opposite in polarity to the algebraic sum of the refresh pulses applied to the pixel between the first addressing pulse and the first blanking pulse. Similarly, the impulse applied to each of the second group of pixels during the second blanking pulse is the sum of (c) the impulse needed to drive the pixel from black to white; and (d) an impulse equal in magnitude but opposite in polarity to the algebraic sum of the refresh pulses applied to the pixel between the first addressing pulse and the first blanking pulse.
  • The refresh pulse method of the invention may be used with any of the types of electro-optic medium previously described. Thus, in this method, the display may be a rotating bichromal member or electrochromic display, or an electrophoretic display, desirably an encapsulated electrophoretic display.
  • In another aspect, this invention provides a method for addressing a bistable electro-optic medium which comprises applying to the medium an alternating current pulse having a direct current offset.
  • In another aspect, this invention provides a method for addressing a bistable electro-optic medium which comprises applying to the medium an alternating current pulse, and varying at least one of the duty cycle and the frequency of the pulse to change the optical state of the electro-optic medium following the alternating current pulse.
  • In another aspect, this invention provides a method for addressing a bistable electro-optic display having a plurality of pixels arranged in a plurality of rows and a plurality of columns, a plurality of row electrodes each associated with one of the plurality of rows, a plurality of column electrodes each associated with one of the plurality of columns, and drive means arranged to select each of the row electrodes in turn and to apply to the column electrodes during the selection of any given row electrode voltages chosen so as to address the pixels in the row associated with the selected row electrode and write one row of a desired image on to the display. The method comprises:
  • writing a first image to the display;
  • receiving data representing a second image to be written to the display;
  • comparing the first and second images and dividing the rows of the display into a first set, in which at least one pixel of the row differs between the first and second images, and a second set, in which no pixel of the row differs between the first and second images; and
  • writing the second image by sequentially selecting only the row electrodes associated with the first set of rows, and applying voltages to the column electrodes to write only the first set of rows, thereby forming the second image on the display.
  • In another aspect, this invention provides an electro-optic display having a plurality of pixels, at least one of the pixels comprising a plurality of sub-pixels differing from each other in area, the display comprising drive means arranged to change the optical state of the sub-pixels independently of one another. In such a display, desirably at least two of the sub-pixels differ in area by substantially a factor of two.
  • BRIEF DESCRIPTION OF DRAWINGS
  • Preferred embodiments of the present invention will now be described, though by way of illustration only, with reference to the accompanying drawings, in which:
  • FIG. 1 is a graph showing variations of gray level with time in a display addressed using a direct current pulse with pulse length modulation;
  • FIG. 2 is a graph similar to FIG. 1 for a display addressed using a direct current pulse with pulse height modulation;
  • FIG. 3 is a graph similar to FIG. 1 for a display addressed using an alternating current pulse with a direct current offset in accordance with the present invention;
  • FIG. 4 is a graph similar to FIG. 1 for a display addressed using an alternating current pulse with duty cycle modulation in accordance with the present invention;
  • FIG. 5 is a graph showing variations of gray level with time in a display addressed using a double-prepulse slideshow waveform;
  • FIG. 6 is a graph showing variations of gray level with time in a display addressed using a single-prepulse slideshow waveform; and
  • FIGS. 7A and 7B show possible arrangements of sub-pixels within a single pixel of a display of the present invention.
  • DETAILED DESCRIPTION
  • As already indicated, the present invention provides a number of improvements in methods for addressing electro-optic media and displays, and in the construction of such displays. The various aspects of the invention will now be described sequentially, but it should be recognized that a single electro-optic medium or display may make use of more than one aspect of the invention. For example, a single electro-optic display might use AC pulse with DC offset driving and also use refresh pulses.
  • Refresh Pulse Method of the Invention
  • As already mentioned, in one aspect the present invention provides a method for refreshing the image on an electro-optic display by applying to the display a short refresh pulse. Thus, in the method of the present invention, one first applies to a pixel of a bistable display an addressing pulse which is sufficient to change the optical state of that pixel. After leaving the display undriven for an interval, one applies to the pixel a refresh pulse which is short relative to the addressing pulse. Typically, the impulse applied by the refresh pulse is not greater than about 20 (desirably not greater than 10, and preferably not greater than 5) percent of the impulse applied by the addressing pulse. For example, if a pixel requires an addressing pulse of 15 V for 500 msec, a refresh pulse could be 15 V for 10 msec, with an impulse of 2 percent of that of the addressing pulse.
  • The timing of the refresh pulses in this method should be adjusted to take account of the sensitivity of the human eye to abrupt small changes in optical state. The human eye is relatively tolerant of gradual fading of an image so that, for example, the bistability of an electro-optic medium of often measured as the time necessary for the lightness L* (defined by the usual CIE definition; see, for example, Hunt, R. W. G. Measuring Color, 3rd edition, Fountain Press, Kingston-upon-Thames, England (1998). (ISBN 0 86343 387 1)) to change by 2 units from the maximum for white optical states (or minimum for black states) observed after the conclusion of the addressing pulse. However, when one applies a refresh pulse to a display, an abrupt change in the lightness of the relevant pixel occurs, and abrupt changes substantially less than 1 unit in L* are readily perceived by the human eye. Depending upon the interval between refresh pulses, the changes in the image caused by these pulses may appear as a “flicker” in the image, and such flicker is highly objectionable to most observers. To avoid such flicker, or other noticeable variation in the image caused by the refresh pulses, it is desirable that the interval between the addressing pulse and the first refresh pulse, or between successive refresh pulses, be chosen so that each refresh pulse causes a minimal change in the image. Thus, the change in L* caused by a single refresh pulse should be less than about 1 unit of L*, desirably less than about 0.5 unit, and preferably less than about 0.2 unit.
  • Although the use of refresh pulses in the present method introduces some DC imbalance into the drive scheme during the period in which the refresh pulses are being applied, it does not preclude achieving long term DC balance in the drive scheme, and it has been found that it is the long term rather than short term DC balance which is of major importance in determining the operating life of electro-optic displays. To achieve such long term DC balance, after one or more refresh pulses have been applied, the pixel which has received the refresh pulses may be driven to its opposed optical state by a “switching” or second addressing pulse, and the impulse applied in this switching addressing pulse may be adjusted to provide DC balance (or at least minimal DC imbalance) over the whole period since the first addressing pulse, by adjusting the impulse of this second addressing pulse by an amount substantially equal in magnitude, but opposite in polarity, to the algebraic sum of the refresh pulses applied to the pixel between the two addressing pulses. For example, consider a display which can be switched between white and black optical states by applying an impulse of ±15 V for 500 msec. Suppose a pixel of this display is first switched from black to white by applying an impulse of +15 V for 500 msec, and the white state of the pixel is subsequently maintained by applying at intervals ten refresh pulses each of +15 V for 10 msec. If after these ten refresh pulses, it is desired to return the pixel to its black optical state, this may be achieved by applying an addressing pulse of −15 V for 600 (rather than 500) msec, thereby achieving overall DC balance over the whole black-white-black transition of the pixel.
  • This type of adjustment of the switching addressing pulse may be effected when a new image is to be written on the display and it is thus necessary to change the optical states of certain pixels. Alternatively, the adjustment may be carried out during the application of “blanking pulses” to the display. As discussed in the aforementioned application Ser. No. 10/065,795, it is often necessary or desirable to apply at regular intervals to an electro-optic display so-called “blanking pulses”; such blanking pulses involve first driving all the pixels of the display to one extreme optical state (for example, a white state), then driving all the pixels to the opposite optical state (for example, black), and then writing the desired image. Effecting the adjustment during blanking pulses has the advantage that all of the pixels may be DC balanced at substantially the same time; the pixels which were black in the prior image (the image present immediately prior to the blanking pulse) can be DC balanced during the blanking pulse which drives all pixels white, while the pixels which were white in the prior image can be DC balanced during the blanking pulse which drives all pixels black, using the technique already described in detail above. Also, effecting the adjustment during blanking pulses can avoid the need to keep track of how many refresh pulses each individual pixel has received since its previous addressing pulse; assuming that black and white pixels are refreshed at the same intervals (as will usually be the case), and that a blanking pulse is inserted at each image transition, each pixel will need the same adjustment (except for polarity) during the blanking pulse, this adjustment being determined by the number of refresh pulses which have been applied to the display since the previous blanking pulse. Also, effecting DC balancing during blanking pulses provides a way to apply the refresh pulse method to electro-optic displays having more than two gray levels, since obviously adjusting the impulse applied during a gray-to-gray transition in such a display may lead to undesirable errors in gray levels.
  • The refresh pulse method of the present invention may be used as an alternative to, or in combination with, additives for increasing the bistability of an electro-optic medium. For example, the present invention may be used with the electrophoretic media described in the aforementioned 2002/0180687, which media have a suspending fluid having dissolved or dispersed therein a polymer which increases the bistability of the medium.
  • The following Example is now given, though by way of illustration only, to show one embodiment of the refresh pulse method of the present invention.
  • EXAMPLE 1
  • This Example uses displays containing an encapsulated dual particle opposite charge type medium comprising a polymer-coated titania white particle and a polymer-coated black particle with an uncolored suspending fluid. The displays were prepared substantially according to “Method B” described in Paragraphs [0061]-[0068] of the aforementioned 2002/0180687.
  • The displays prepared as described above, which contained multiple pixels, could be switched between their black and white optical states using addressing pulses of ±15 V for 500 msec. The displays had only limited bistability, the time necessary for the white optical state to change by 2 L* units being only about 15 sec. at ambient temperature. However, it was determined empirically that the white and black optical states could be maintained indefinitely by applying short refresh pulses of ±15 V for 4 sec/min, a duty cycle of approximately 6.7 percent. To provide a realistic test and avoid flicker in a standard image (containing both black and white areas) used in these experiments, after an initial 500 msec addressing pulse, ±15 V refresh pulses of approximately 7 msec duration were applied to both the black and white pixels of the display at intervals of approximately 100 msec.
  • To determine the effects of various periods of DC imbalanced drive schemes on the displays, four different drive schemes were tested:
  • Scheme 480:
  • The display was addressed with the standard image, and this image was maintained using the aforementioned refresh pulses for 480 minutes. A series of blanking pulses were then applied, and the cycle of addressing and refresh pulses repeated. No DC balancing pulse was applied at any time. After 83 hours of operation, a series of blanking pulses were applied and then separate areas of the display, which had been white and black respectively in the standard image were tested. The area of the display which had been held white during the testing period is denoted by “480W” in the Table below, while the area which has been held black is denoted by “480D”. Each tested area was driven to its white optical state by a standard 500 msec addressing pulse, and its percentage reflectance value measured; this value is denoted by “w %” in the Table. Each tested area was then allowed to stand for 15 sec without any refresh pulses being applied, and the change in L* measured after this 15 second interval; the resultant change in L*, known as the “bright holding difference”, is denoted by “bhdl” in the Table. After applying further blanking pulses, each tested area was driven to its black optical state by a standard 500 msec addressing pulse, and its percentage reflectance value measured; this value is denoted by “d %” in the Table. Each tested area was then allowed to stand for 15 sec without any refresh pulses being applied, and the change in L* measured after this 15 second interval; the resultant change in L*, known as the “dark holding difference”, is denoted by “dhdl” in the Table.
  • Scheme 60:
  • This scheme was identical to Scheme 480, except that the image was maintained for only 60 minutes before blanking pulses were applied. The area of the display which had been held white during the testing period is denoted by “60W” in the Table below, while the area which has been held black is denoted by “60D”.
  • Scheme 10:
  • In this scheme, the image was written in the same way as in Scheme 480, and maintained for 10 minutes using the same refresh pulses as in Scheme 480. A 40 sec pulse of opposite polarity was then applied to DC balance the display, and then the image was rewritten and the cycle repeated. The area of the display which had been held white during the testing period is denoted by “10W” in the Table below, while the area which has been held black is denoted by “10D”.
  • Scheme 1:
  • This scheme was identical to Scheme 10, except that the image was maintained for only 1 minute and then a 4 second DC balancing pulse was applied and the cycle repeated. The area of the display which had been held white during the testing period is denoted by “1 W” in the Table below, while the area which has been held black is denoted by “1D”.
  • The results obtained in these experiments are shown in Table 1 below.
    TABLE 1
    480 W 480 D 60 W 60 D
    w % 37.90 30.63 38.21 38.47
    d % 2.89 2.69 3.03 2.45
    dhdl 2.05 0.64 4.79 1.05
    bhdl −1.34 −4.06 −0.47 −2.72
    10 W 10 D 1 W 1 D
    w % 37.31 37.39 37.20 37.20
    d % 2.75 2.75 3.14 3.13
    dhdl 0.89 0.84 0.98 0.99
    bhdl −2.24 −2.30 −2.02 −1.98
  • From the data in Table 1, it will be seen that, in the highly unbalanced Scheme 480, the white state reflectance differed markedly between the areas of the display held white and black during the testing period, and the bright and dark holding differences also differed markedly. Thus, this highly unbalanced drive scheme produced substantial change in the optical states of the display, quite apart from any other effects, such as damage to the electrodes, which may occur with such unbalanced drive schemes. Also, as shown by the differences in bright and dark holding differences, the unbalanced drive scheme introduced a “bias” to the display, in the sense that areas held white for long periods tended to remain white thereafter whereas areas held black for long periods tended to remain black thereafter. The results obtained from the unbalanced Scheme 60 were similar but, as would be expected, less marked. In contrast, both the DC balanced Schemes 10 and 1 showed essentially no differences between the areas held white and black.
  • Thus, these experiments showed that the temporary DC imbalance produced by the use of short refresh pulses did not adversely affect the properties of the displays provided that long term DC balance was produced by spaced blanking pulses.
  • Electrophoretic media used in the refresh pulse method of the present invention may employ the same components and manufacturing techniques as in the aforementioned E Ink and MIT patents and applications, to which the reader is referred for further information.
  • Fundamental Elements of Grayscale Drive Waveforms (Including use of AC Pulses)
  • Currently, as described in the aforementioned U.S. Pat. Nos. 6,531,997 and 6,504,524, many displays are switched from one extreme optical state to the other (for example, from black to white or vice versa) by applying a voltage pulse of sufficient duration to saturate the electro-optic medium; for example, in a particle-based electrophoretic medium, to move charged particles all the way to a front or back electrode. The conventional requirement that the electro-optic medium be addressed until the optical state becomes saturated does not allow for intermediate gray states. An electro-optic display that achieves grayscale offers significant advantages in graphics capability and image quality.
  • For convenience, a voltage waveform or drive scheme capable of achieving grayscale in a bistable electro-optic display may hereinafter be called a “grayscale waveform” or “grayscale drive scheme” respectively. There are five fundamental grayscale waveform elements which may be used in such a grayscale waveform or drive scheme; the term “grayscale waveform element” is used to mean a voltage pulse, or series of voltage pulses, that is capable of producing a change in optical state of an electro-optic display. A grayscale waveform element is itself capable of generating grayscale, and one or more grayscale waveform elements arranged in a particular sequence together form a grayscale drive waveform. A grayscale drive waveform is capable of switching a pixel of a display from one gray state to another. A sequence of one or more drive waveforms makes up a drive scheme, which is capable of displaying any series of grayscale images on a display.
  • Drive waveform elements fall into two basic categories, namely direct current (DC) voltage pulses and alternating current (AC) voltage pulses. In both cases, the parameters of the pulse that can be varied are the pulse height and the pulse length.
  • Although the generation of a grayscale optical state in an electro-optic medium is critically dependent on the manner in which voltage is applied to the medium, the ability of the medium to hold that grayscale optical state once the voltage is no longer applied is equally important in grayscale addressing schemes and this ability will depend upon the nature of the medium, as indeed will all grayscale switching properties. In this application, grayscale addressing schemes will primarily be discussed with reference to encapsulated particle-based electrophoretic media, but it is considered that the necessary modifications of such schemes to allow for the properties of other types of bistable electro-optic media will readily be apparent to those skilled in the technology of such media.
  • The fundamental elements of grayscale drive waveforms are as follows:
  • DC Pulse with Pulse Length Modulation
  • One of the least complex methods of realizing a desired gray state is to stop addressing the pixel in the middle of a transition from one extreme optical state to the other. In FIG. 1 of the accompanying drawings, the inset illustrates the DC pulse length modulated waveform elements used to produce the grayscale transitions in an encapsulated electrophoretic medium shown in the main part of the Figure. (The displays used in this and subsequent experiments described below were prepared substantially according to “Method B” described in Paragraphs [0061]-[0068] of the aforementioned 2002/0180687.) The three pulses used were 15 V for 200, 400 and 600 msec respectively, and the three curves produced are labelled accordingly; note that the time scale in the inset is not the same as that in the main Figure. Thus, the pulse height was fixed, while the duration of the pulse was varied for different changes in reflectivity. In FIG. 1, the reflectivity of a pixel, whose reflective state was changed from black to different levels of gray upon application of these voltage pulses, is plotted against time; it will be seen that longer pulse lengths yielded greater changes in reflectivity.
  • The display tested responded immediately to the end of the applied voltage pulse, and its optical state ceased to evolve. On the microscopic level, it may be presumed that the electrophoretic particles instantly stop in transit from one electrode to the other and remain suspended at an intermediate position within the capsule.
  • An advantage of a DC grayscale drive pulse with pulse length modulation is the speed with which the desired gray state is achieved.
  • DC Pulse with Pulse Height Modulation
  • Another approach to achieving a desired gray state is to address a pixel with a lower voltage than is required to fully switch from one extreme optical state of the pixel to the other. In FIG. 2 of the accompanying drawings, the inset illustrates the DC pulse height modulated waveform elements used to produce the grayscale transitions in an encapsulated electrophoretic medium shown in the main part of the Figure. The voltage pulse length is fixed at the length of time required to completely switch the medium at the maximum voltage level. The three pulses used were 5, 10 and 15 V for 500 msec respectively, and the three curves produced are labelled accordingly; note that the time scale in the inset is not the same as that in the main Figure. Thus, the pulse length was fixed, while the height of the pulse was varied for different changes in reflectivity. In FIG. 2, the reflectivity of a pixel, whose reflective state was changed from black to different levels of gray upon application of these voltage pulses, is plotted against time; it will be seen that greater pulse heights yielded greater changes in reflectivity.
  • It may be presumed that the electrophoretic particles travel through the suspending fluid at slower speeds at lower voltages and remain suspended when the driving voltage ceases to be applied.
  • An advantage of a DC grayscale drive pulse with pulse height modulation is accurate control of the gray state achieved.
  • AC Pulse with Dc Offset Modulation
  • Grayscale driving of the aforementioned encapsulated electrophoretic medium has been effected with oscillating (AC) electric fields; the switching mechanism with such AC fields is presumed to be entirely different from that effected in the DC driving of the same medium discussed above. In FIG. 3 of the accompanying drawings, the inset illustrates the AC pulse with DC offset modulation waveform elements used to produce the grayscale transitions in an encapsulated electrophoretic medium shown in the main part of the Figure. In all cases, the frequency of the AC component (approximately 10 Hz) was set at a value that allowed the particles to respond to the oscillating field, while the magnitude and direction of the DC offset (which was 0, −1 or −2.5 V, as indicated for the three curves in FIG. 3) determined the gray state that the pixel eventually attained. As in previous Figures, the time scale used in the inset is not the same as that in the main Figure. In FIG. 3, the reflectivity of a pixel, whose reflective state was changed from black to different levels of gray upon application of these voltage pulses, is plotted against time; it will be seen that greater DC offsets yielded greater changes in reflectivity.
  • Upon application of an AC field, the electrophoretic particles oscillate in the suspending fluid and this oscillation is observed motion as a cyclic variation in reflectivity, superimposed upon the overall change in reflectivity, as is readily seen on the left hand side of FIG. 3. There was no net effect on reflectivity, however, until the DC offset was applied. Under the influence of a DC offset, the reflectivity approaches a constant value after the waveform has been applied for some time. It appears that there must be a restoring force that opposes the force on the particles due to the DC offset voltage, otherwise, the particles would continue to flow to the cell wall. This restoring force may be due to the motion of fluid in between the capsule wall and the particles and/or to the interaction of the particles directly with the cell wall. The stability of the optical state after the voltage is released appears consistent with that of other waveform elements.
  • An advantage of AC waveform elements is the ability to reach a particular reflectivity state by specifying the parameters of the waveform element, while DC waveform elements enable only a change in reflectivity. An advantage of an AC waveform element with DC offset over other AC waveform elements is that precise timing of the addressing pulse is not required.
  • AC Pulse with Duty Cycle Modulation
  • Another way to induce a DC bias with an oscillating field is to modulate the duty cycle. In FIG. 4 of the accompanying drawings, the inset illustrates the AC pulses with duty cycle modulation used to produce the grayscale transitions shown in the main part of the Figure. In each of the pulses, the voltage is set to a maximum value, and the duty cycle (the percentage of time that the voltage is in the positive or negative direction) determines the reflectivity. The three duty cycles used were 50, 47 and 40 percent, as indicated in FIG. 4. As in previous Figures, the time scale used in the inset is not the same as that in the main Figure. In this Figure, the reflectivity of a pixel, whose reflective state was changed from black to different levels of gray upon application of the voltage pulses, is plotted against time.
  • It will be seen from FIG. 4 that, as with the AC/DC offset pulses used to generate the curves shown in FIG. 3, the curves shown in FIG. 4 approach a constant value after the pulses have been applied for some time. Thus, as with AC/DC offset, with duty cycle modulation there appears to exist a restoring force that forces the particles away from the cell wall, maintaining a constant gray state. The physical mechanism for the restoring force appears likely the same as discussed above. Again, the gray state ceases to change immediately the pulses cease to be applied.
  • An advantage of an AC waveform with duty cycle modulation is that voltage modulation is not required.
  • AC Pulse with Frequency Modulation
  • Another approach to AC grayscale switching is to apply to an electro-optic medium an AC field which causes the optical state of the medium to oscillate and then to terminate the AC field in mid-cycle at the point having the desired reflectivity. The voltage may be set at a maximum value and the AC frequency varied in order to achieve a greater or lesser reflectivity range. The frequency determines the amplitude of the oscillation in reflectivity.
  • When such an approach is applied to an encapsulated particle-based electrophoretic medium, the electrophoretic particles respond to the AC field by oscillating around their initial positions. Since the reflectivity typically does not reach either the extreme black or white optical state, interactions with the cell wall are minimized and the response of the reflectivity is relatively linear with the applied voltage.
  • An advantage of AC pulses with frequency modulation is that voltage modulation is not required.
  • By combining the types of pulses discussed above, a multitude of waveform elements can be developed, each involving unique switching mechanisms, thus providing versatile methods for driving differing electro-optic media with differing switching characteristics.
  • In one specific application of the drive scheme principles discussed above, pulse width modulation and AC pulses are used to achieve an intermediate gray state in an electro-optic display which otherwise would be capable of achieving only black and white states.
  • For reasons already discussed, the ability to achieve gray scale is highly desirable in electro-optic displays. However, providing a large number of gray levels requires either pulse width modulation with a high frame rate driver (the high frame rate being needed to “slice” the pulse width into a large number of intervals, thereby enabling pulse width and hence gray scale to be controlled very accurately) or a driver capable of voltage modulation. Either type of driver is substantially more costly than the simple tri-level drivers, which enable individual pixels of a display to be set only to +V, −V and 0 potential (where V is an arbitrary operating potential) relative to the potential of a common front plane electrode, and which are commonly used to drive displays capable of only black and white states.
  • This invention provides a drive scheme which enables a tri-level driver to produce a gray level intermediate the black and white levels of a bistable electro-optic display. The drive scheme is most easily appreciated from the following Table 2, which shows the voltage applied during the successive frames of various types of transitions in such a display of the present invention:
    TABLE 2
    0 1 2 3 4 5 6 . . . N − 1 N
    white to black +V +V +V +V +V +V +V . . . +V +V
    black to white −V −V −V −V −V −V −V . . . −V −V
    white to gray +V +V +V +V −V +V −V . . . +V −V
    black to gray −V −V −V −V +V −V +V . . . −V +V
    gray to black +V +V +V 0 0 0 0 0 0 0
    gray to white −V −V −V 0 0 0 0 0 0 0
  • As may be seen from Table 2 above, the transitions from black to white or vice versa are the same as in a binary (black/white only) display. The transitions to gray, on the other hand, have two parts. The first part is a square wave pulse (i.e., a plurality of frames at the same potential) of the proper polarity and length to bring the reflectivity of the electro-optic medium as close as possible to the desired middle gray lightness. The accuracy possible with this step will be limited by the frame rate of the display. The second part of the addressing pulse consists of an equal number of positive and negative voltage pulses, each one frame in width. As discussed above with reference to FIGS. 3 and 4, it has previously been demonstrated that the application of an AC square wave to an encapsulated particle-based electrophoretic medium causes the medium to “relax” to some “middle gray” state. Therefore, this second part of the pulse will bring all of the pixels to the same uniform middle gray state, regardless of previous pulse history. Addressing out from the gray state to black or white is accomplished with a short pulse of the proper polarity.
  • More generally, the AC portion of the pulse need not switch polarity every frame, but may switch at a lower frequency, with the voltage alternating every other frame (frequency=frame rate/4), or more generally every nth frame (frequency=frame rate/2n).
  • Thus, this invention provides a method to produce a single gray level in an otherwise binary electro-optic display using only a simple tri-level driver rather than without the use of a complex and costly voltage modulated driver.
  • In a second specific application of the drive scheme principles discussed above, this invention provides a collection of two-dimensional transition matrices, wherein each element in the matrix specifies how to get from an initial optical state (denoted “the row index” herein, although obviously the allocation of the initial optical states to rows is arbitrary) to a final optical state (denoted “the column index” herein). Each element of this matrix is constructed from a series of waveform elements (as defined above), and in general, for an n-bit grayscale display, this matrix will contain 2(2N) elements. The matrices of the present invention take account of such considerations as the need for DC balancing of the drive scheme (as discussed above), minimizing “memory” effects in certain electro-optic media (i.e., effects whereby the result of applying a particular pulse to a pixel depends not only upon the current state of the pixel but also upon certain prior states), thereby producing uniform optical states and maximizing the switching speed of the display, while working within the constraints of an active matrix drive scheme. The present invention also provides a method for determining the optimal values of each term of the elements in such a matrix for any specific electro-optic medium. For further discussion of such matrices and their use in driving electro-optic displays, the reader is referred to the aforementioned copending application Ser. No. 10/065,795.
  • The presently preferred waveforms of the invention are described below in terms of pulse width modulation (PWM) as discussed above. However, the same or similar results may be achieved using pulse height modulation, or the various hybrid types of AC modulation discussed above, and various different types of modulation may be employed within a single waveform, for example, pulse width modulation for all but the last section of the pulse, followed by voltage modulation on the last section of the pulse.
  • The first two waveforms of the present invention described below are “slide show” waveforms, which return from one gray state to the black state before addressing out to the next gray state. Such waveforms are most compatible with a display update scheme where the entire screen blanks at once, as in a slide projector.
  • Double-Prepulse Slideshow Waveform
  • In this waveform, a preferred form of which is illustrated in FIG. 5 of the accompanying drawings, a pixel of the electro-optic medium is initially driven (as indicated at 100) from black to an initial (first) gray state using a partial pulse. To change the pixel from this initial gray state to a different desired (second) gray state, the pixel is first driven (at 102) from the first gray state to white, and then (at 104) from white to black. Finally, the proper pulse to reach the second gray state is applied at 106. To ensure that this type of waveform preserves overall DC balance, it is necessary that the sum of the lengths of the addressing pulse at 106 and the white pulse at 102 equal the length of the white-black pulse at 104. This waveform requires a maximum of three times the switching time of the medium (i.e., the time necessary for a single pixel to switch from its black optical state to its white optical state or vice versa) to effect a transition between any two arbitrary gray states, and is therefore referred to as a 3× waveform.
  • Single-Prepulse Slideshow Waveform
  • In this waveform, a preferred form of which is illustrated in FIG. 6 of the accompanying drawings, a pixel of the electro-optic medium is initially driven (as indicated at 110) from black to an initial (first) gray state using a partial pulse, in the same way as in the double-prepulse waveform discussed in Section 6 above. To change the pixel from this initial gray state to a different desired (second) gray state, the pixel is first driven (at 112) from the first gray state to black, then the proper pulse to reach the second gray state is applied at 114. Obviously, before a second transition, the pixel will again be returned to black at 116. This type of waveform preserves DC balance of the overall waveform, since the impulses applied at 112 and 116 are equal (except for polarity) to the impulses applied at 110 and 114 respectively. This waveform requires a maximum of twice the switching time of the medium to effect a transition between any two arbitrary gray states, and is therefore referred to as a 2× waveform.
  • Gray-to-Gray Waveforms
  • Instead of using the slideshow waveforms described above, a display may be updated by addressing it directly from one gray state to another without passing through a black or white state. Since there are no obvious artifacts (i.e., black and/or white “flashes”) associated with such a transition, it may be referred to as “gray-to-gray” addressing. There are two main forms of gray-to-gray waveform, namely DC-balanced and DC-imbalanced.
  • In a DC-balanced gray-to-gray waveform, the transition between any two gray states is effected by applying a modulated pulse of the precise length necessary to shift between the two states. The electro-optic medium does not pass through any intermediate black or white states. Since the maximum pulse length is equal to the addressing time of the ink, such a waveform may be referred to as a 1× waveform. To maintain DC balance, for a display with n gray states, there are n−1 free parameters available in the optimization of the transition matrix associated with any specific waveform. This results in a highly over-constrained system. For example, all transitions are required to be equal and opposite in impulse to the reverse transition (i.e. 2-3 must be the same as 3-2, except for polarity).
  • A DC-imbalanced gray-to-gray waveform is fundamentally the same as a DC-balanced one, except that the pulse lengths are no longer constrained by the restriction of DC balancing. Thus, each of the 2(2N) entries in the transition matrix can vary independently of all the others.
  • The various waveforms discussed above enable grayscale addressing in active matrix displays, which is crucial for the use of electro-optic media in personal digital assistant (PDA) and electronic book applications. These waveforms minimize the effects of memory in the electro-optic medium, and such memory can lead to image ghosting. By choosing optimal pulse lengths and sequences, desired gray optical states can be achieved in a minimum number of pulses.
  • Selective Row Driving
  • Another aspect of the present invention relates to improving the performance of an active matrix bistable electro-optic display by selective driving of the rows of the display.
  • As already mentioned, and as discussed in more detail in some of the aforementioned patents and applications, to maintain a desired image on a conventional LCD, the whole image area must be continuously refreshed, since typically liquid crystals are not bistable and an image on an LCD will fade within a very short time unless refreshed. As is well known to those skilled in the art of active matrix LCD's, in such displays the continuous refreshment is effected by using a row driver to turn on the gates of the transistors associated with one row of pixels of the display, placing on column drivers (connected to the source electrodes of the transistors in each column of the display) the potentials needed to write to the pixels in the selected row the relevant portion of the desired image on the display, and thus writing the selected row of the display. The row driver then selects the next row of the display and the process is repeated, with the rows thus being refreshed cyclically. (The assignment of the row drivers to gate electrodes and the column drivers to source electrodes is conventional but essentially arbitrary, and could of course be reversed if desired.)
  • Because an LCD requires continuous refreshing of an image, a change of only part of a displayed image is handled as part of the overall refreshing procedure. In a continuously-refreshed display there need be no provision for updating part of an image; since in effect a new image is being written to the display several times per second (in the case of an LCD), any change of part of an image fed to the display automatically appears effect on the display within a short interval. Consequently, the conventional circuitry developed for use with LCD's makes no provision for updating of only part of an image.
  • In contrast, bistable electro-optic displays do not need continuous refreshing, and indeed such continuous refreshing is undesirable, since it unnecessarily increases the energy consumption of the display. Furthermore, during such refreshing, the gate (row) lines may deliver capacitative voltage spikes to pixel electrodes, and any driver voltage errors or uncompensated gate feedthrough bias errors can accumulate; all these factors can result in undesirable shifts in the optical states of the pixels of the display. Accordingly, in bistable electro-optic displays it is desirable to provide some means for updating a portion of an image without the need to rewrite the whole image on the display, and one aspect of this invention relates to a bistable electro-optic display provided with such “partial updating” means. According to the present invention, this is done by comparing successive images to be written to the display, identifying the rows which differ in the two images, and addressing only the rows thus identified.
  • In the present method, to effect a partial update of a display only the rows of the display containing pixels which are to change optical state are identified. In a preferred form of this method, for every line of the display, a display controller (cf. the aforementioned copending application Ser. No. 10/065,795) examines all of the desired pixel electrode output voltages. If all of the output voltages for that line are equal to the potential Vcom of the common front electrode of the display (i.e., if no pixel in that row needs to be rewritten), then the controller outputs a synchronizing (Vsync) pulse without loading data values into the column drivers, and without issuing a corresponding output enable (OE) command. The net effect of this is that the token bit for the row drivers is passed to the next row of the display without activating the current row. Data is only loaded into the column drivers, and output enable is only asserted, for rows where at least one pixel needs to be rewritten.
  • This invention gives two distinct types of advantages. Firstly, many sources of spurious voltage are eliminated for pixels that are not rewritten. There is no capacitative gate spike for these pixels, and errors in the column driver voltage will not be passed on to a pixel in frames where it is not addressed. Because of the relatively lower resistivity of many electro-optic media, especially electrophoretic media, as compared with liquid crystals, the pixel electrode will tend to relax to the actual front plane voltage, thus maintaining the hold state of the electro-optic medium. Secondly, power consumption of the display is minimized. For every row that is not rewritten, the corresponding gate line does not have to be charged. In addition, when data is not loaded into the column drivers of the display, the additional power consumption of moving that data across the display interface is also eliminated.
  • Spatial Area Dithering
  • The aspects of the present invention previously discussed relate to the waveforms used to drive electro-optic displays. However, the behavior of such displays can also be changed by varying the structure of the backplane, and this aspect of the invention relates to dividing one or more pixel, and preferably each pixel, of a display into a plurality of sub-pixels having differing areas.
  • As already noted, it is highly desirable to provide grayscale in an electro-optic display. This gray scale may be achieved either by driving a pixel of the display to a gray state intermediate its two extreme states. However, if the medium is not capable of achieving the desired number of intermediate states, or if the display is being driven by drivers which are not capable of providing the desired number of intermediate states, other methods must be used to achieve the desired number of states, and this aspect of the invention relates to the use of spatial dithering for this purpose.
  • A display may be divided into a plurality of “logical” pixels, each of which is capable of displaying the desired number of gray or other optical states. However, obviously more than one physically separate area can be present at each logical pixel, and indeed it is common in color displays to make use of “full color” logical pixels each of which comprises three sub-pixels of primary colors, for example red, green and blue; see, for example, the aforementioned 2002/0180688. Similarly, one could achieve gray scale by using as a logical pixel an assembly of sub-pixels, each of which was capable of only binary switching. For example, a logical pixel comprising four independently controllable sub-pixels of equal area could be used to provide two-bit gray scale. However, for anything more than one- or two-bit gray scale, the number of sub-pixels becomes inconveniently great, since the required number of sub-pixels doubles for each one-bit increase in gray scale.
  • The present invention provides an electro-optic display having at least one pixel which comprises a plurality of sub-pixels, these sub-pixels being of differing areas. In a preferred embodiment of this invention, at least two sub-pixels differ in area by substantially a factor of two. Thus, for example, a logical pixel might have sub-pixels with areas of 1X, 2X and 4X, where X is an arbitrary area. A logical pixel of this type is illustrated schematically in FIG. 7A of the accompanying drawings. This logical pixel achieves three-bit grayscale using only three electrodes, whereas achieving the same three-bit grayscale with sub-pixels of equal area would require eight sub-pixels.
  • When driven, each sub-pixel reflects or transmits a portion of the incoming light, and the fractional amount is dictated by the area of the sub-pixel. If the reflectance/transmission is averaged over the area of the logical pixel, then a binary weighting of driven area is achieved, and hence spatially dithered grayscale.
  • The areas of the sub-pixels are arbitrary. The ones shown in FIG. 7A are weighed by reflectance. If one were to use a non-linear weighting (as would be appropriate for equal steps in L* or a gamma corrected grayscale spacing), the areas would be changed accordingly.
  • Careful consideration should be given to the shape of the sub-pixels, in addition to consideration of their relative areas. Simple large blocks, as in FIG. 7A, allow simple patterning of the sub-pixel array, but under certain conditions the sub-pixels may be resolved by a viewer. Also, if a large area (covering many logical pixels) is displayed with a mid-level gray (so that (say) only the area 4 in FIG. 7A is driven in each logical pixel), a viewer still see a line or grating pattern arising from the pattern of sub-pixels.
  • Increasing the resolution of the logical pixels reduces these problems, but requires a large number of additional pixels, however, as the number of pixels increases as the square of the resolution. Instead, the problems of sub-pixel visibility and/or visible patterning can be reduced by interdigitating the sub-pixels as shown, for example, in FIG. 7B; note that this Figure is only intended to illustrate interdigitation, and not to accurately represent the relative areas of the sub-pixels. Many interdigitated patterns similar to that of FIG. 7B can be used to improve image quality.
  • Another approach to dealing with the problems of sub-pixel visibility and/or visible patterning is to randomly orient the sub-pixels. For example, in an array of pixels each of which has the sub-pixel arrangement shown in FIG. 7A, individual pixels could have, at random, each of the four possible orientations of the arrangement shown in FIG. 7A. Such “randomization” of the sub-pixels helps to break up patterns and render them less noticeable to an observer.
  • Although the embodiments of the present invention shown in FIGS. 7A and 7B produce three-bit grayscale, it will be appreciated that the present invention can produce any number of bits of gray scale simply by adding additional sub-pixels.
  • This aspect of the present invention has the advantages that:
  • (a) The electro-optic medium itself does not need to be capable of gray scale; essentially the display can be a black/white display, and sub-pixels turned on and off to produce gray scale. In a scanned array, the necessary control of the sub-pixels can be achieved by providing additional column drivers for the same number of rows, as in color sub-pixel arrays. This reduces demands upon the electro-optic medium used; for example, one does not need to worry about possible drift of gray levels of the medium over its operating lifetime.
  • (b) There is no need for complicated column drivers; the present invention is compatible with simple use binary level drivers used in many conventional displays. thus facilitating the use of a variety of electro-optic media with readily available, inexpensive “off-the-shelf” components. Some methods of generating grayscale require voltage modulated drivers for the column electrodes, and such drivers are not widely available and are more expensive/harder to build than binary level drivers.
  • (c) The thin film transistor (TFT) design for an active matrix array using the present invention need be no harder than that required for full color, where there are three sub-pixels (for example, RGB) per pixel, and the amount of data which needs to be supplied to the various components is no greater. Thus no new technology development is required in an active matrix backplane to implement the present invention.
  • Miscellaneous Techniques
  • In most conventional active matrix drive schemes for electro-optic displays, the voltages of the pixel electrodes on the display backplane are varied in order to impose desired voltages across pixels. The top plane is typically held at a particular voltage deemed advantageous for addressing the pixels. For example, if the data line voltage supplied to the pixel electrodes varies between zero volts and a voltage V0, the top plane may be held at V0/2 in order to permit voltage drops across the pixel to be as large as V0/2 in both directions.
  • According to one aspect of this invention, the voltage of the top plane may be varied to enhance the addressing of the electro-optic medium. For example, the top plane voltage could be held at zero volts in order to permit the total pixel voltage drop (top plane minus pixel voltage) to be as low at −V0. Raising the top plane up to V0 permits a pixel voltage drop as large as V0. These larger voltage drops permit faster addressing of the electro-optic medium.
  • More generally, it may be advantageous to be able to set the top plane voltage not only at voltages zero and V0, but to other voltages as well. For example, it may be advantageous to apply a global time-varying voltage across the electro-optic medium in concert with pixel-to-pixel voltages imposed by the backplane.
  • It is known to provide an electro-optic display with a capacitor formed between a pixel electrode and an electrode formed by an extension of a select line so as to charged with the same voltage as the select line; as described in the aforementioned WO 01/07961, the provision of such a capacitor reduces the rate of decay of the electric field across the relevant pixel after the driving voltage is removed. In another aspect, this invention provides an electro-optic display having a storage capacitor formed between a pixel electrode and a (second) electrode that has a voltage that can be varied independently from the select lines of the display. In a preferred embodiment, the second electrode follows the top plane voltage, that is, its voltage differs from the top plane only by a time-independent constant. The provision of this type of capacitor greatly reduces the capacitative voltage spikes experienced by the pixel, as compared with a storage capacitor is created by an overlap between a pixel electrode and a select line that controls the adjacent (previous) row of the display.
  • Another aspect of the present invention relates to reducing or eliminating unwanted switching of the electro-optic medium by select and data lines.
  • As discussed above, select and data lines are essential elements of an active matrix panel in that they provide the voltages required for charging pixel electrodes to desired values. However, the select and data lines can have the unwanted effect of switching the electro-optic medium adjacent the data lines. The undesirable optical artifacts caused by such switching can be eliminated by using a black mask to hide the regions switched by the data and/or select lines from a viewer. However, providing such a black mask requires registration of the front plane of the display with its back plane and a reduction in the fraction of the electro-optic medium that is exposed to the viewer. The result is a display darker and lower in contrast than one could achieve without the black mask.
  • In another aspect of the present invention, the need for a black mask is avoided by making the data lines to have a small lateral extent in one direction so that they do not appreciably address the adjacent electro-optic medium during normal display operation. This obviates the need for a black mask.
  • A related aspect of the present invention relates to the use of passivated electrodes and modification of the drive scheme used to drive the electro-optic medium. An impulse-driven electro-optic medium can be electronically addressed when it is in a thin film form between two electrodes. Generally, the electrodes make contact with the electro-optic medium. However, it is also possible to address the medium even when a dielectric material with a long electronic relaxation time exists between one or both electrodes and the medium. Passivation of one or both electrodes may be desirable to avoid adverse chemical or electrochemical interactions at the backplane or front plane of a display device; see the aforementioned WO 00/38001. Although the ability to sustain a voltage across the electro-optic medium is greatly reduced by the presence of a dielectric layer, a voltage impulse can still be applied to the medium and the medium can be addressed through these voltage impulses if the dielectric layer is properly engineered.
  • The optical state of an electro-optic medium is of course achieved by changing the voltage on a pixel electrode. This voltage change results in a voltage across the electro-optic medium that decays as charge leaks through the medium. If an external dielectric layer (i.e., a dielectric layer between the medium and one electrode) is sufficiently thin and the electro-optic medium is sufficiently resistive, the voltage impulse across the medium will be sufficient to cause a desirable shift in the optical state of the medium. Electronic addressing of an electro-optic medium through a dielectric layer is therefore possible. The addressing scheme is different, however, from addressing an electro-optic medium with electrodes in direct contact with the medium since, in the latter case, the medium is addressed by applying voltages across the pixel, whereas, in the former case, addressing is achieved by causing a change in the pixel voltage. At every change, a voltage impulse is experienced by the electro-optic medium.
  • Finally, this invention provides drive schemes for reducing cross-talk in active matrix electro-optic displays.
  • Inter-pixel cross-talk, where addressing one pixel affects the optical state of other pixels, is undesirable but has many causes. One cause is the finite current flow through transistors in the off state. Bringing a data line to a voltage intended for charging one pixel can charge up transistors in unselected rows because of off state current leakage. A solution is to use transistors with a low off-state current.
  • Another source of cross talk is current leakage between neighboring pixels. Current can leak through elements of the backplane or through the electro-optic medium in contact with the backplane. A solution to such cross talk is to design the backplane with a large insulating gap between the pixel electrodes. A larger gap will result in smaller leakage currents.
  • As already indicated, a preferred type of electro-optic medium for use in the present invention is an encapsulated particle-based electrophoretic medium. Such electrophoretic media used in the methods and apparatus of the present invention may employ the same components and manufacturing techniques as in the aforementioned E Ink and MIT patents and applications, to which the reader is referred for further information.
  • Numerous changes and modifications can be made in the preferred embodiments of the present invention already described without departing from the spirit of the invention. Accordingly, the foregoing description is to be construed in an illustrative and not in a limitative sense.

Claims (25)

1. A method for addressing a bistable electro-optic medium which comprises applying to the medium an alternating current pulse having a direct current offset.
2. A method according to claim 1 wherein the alternating current pulse has substantially the form of an alternating square wave.
3. A method according to claim 1 wherein the application of the alternating current pulse having a direct current offset to the medium is continued for a period sufficient to cause the medium to assume a substantially constant optical state.
4. A method according to claim 1 wherein there is first applied to the medium an alternating current pulse having a first direct current offset, thereby causing the medium to assume a first optical state, and thereafter there is applied to the medium an alternating current pulse having a second direct current offset different from the first offset, thereby causing the medium to assume a second optical state different from the first optical state.
5. A method according to claim 1 wherein the electro-optic medium is an electrophoretic medium in which a plurality of charged particles move through a fluid under the influence of an electric field.
6. A method according to claim 5 wherein the plurality of charged particles and the fluid are confined within a plurality of capsules.
7. A method according to claim 5 wherein the plurality of charged particles and the fluid are retained within a plurality of cavities formed within a carrier medium.
8. A method according to claim 5 wherein the plurality of charged particles and the fluid are present as a plurality of droplets surrounded by a continuous phase of a polymeric material.
9. A method according to claim 1 wherein the electro-optic medium has a first display state which is substantially opaque and a second display state which is light-transmissive.
10. A method for addressing a bistable electro-optic medium which comprises applying to the medium an alternating current pulse, and varying at least one of the duty cycle and the frequency of the pulse to change the optical state of the electro-optic medium following the alternating current pulse.
11. A method according to claim 10 wherein the alternating current pulse has substantially the form of an alternating square wave.
12. A method according to claim 1 wherein the application of the alternating current pulse to the medium is continued for a period sufficient to cause the medium to assume a substantially constant optical state.
13. A method according to claim 10 wherein the duty cycle but not the frequency of the alternating current pulse is varied.
14. A method according to claim 13 wherein there is first applied to the medium an alternating current pulse having a first duty cycle offset, thereby causing the medium to assume a first optical state, and thereafter there is applied to the medium an alternating current pulse having a second duty cycle offset different from the first duty cycle, thereby causing the medium to assume a second optical state different from the first optical state.
15. A method according to claim 10 wherein the frequency but not the duty cycle of the alternating current pulse is varied.
16. A method according to claim 10 wherein the electro-optic medium is an electrophoretic medium in which a plurality of charged particles move through a fluid under the influence of an electric field.
17. A method according to claim 16 wherein the plurality of charged particles and the fluid are confined within a plurality of capsules.
18. A method according to claim 16 wherein the plurality of charged particles and the fluid are retained within a plurality of cavities formed within a carrier medium.
19. A method according to claim 16 wherein the plurality of charged particles and the fluid are present as a plurality of droplets surrounded by a continuous phase of a polymeric material.
20. A method according to claim 10 wherein the electro-optic medium has a first display state which is substantially opaque and a second display state which is light-transmissive.
21. A method for addressing a bistable electro-optic medium capable of displaying at least three optical states including two extreme optical states and at least one gray state intermediate the two extreme optical states, which method comprises driving the medium from one extreme optical state to a final gray state by first applying to the medium a direct current pulse which drives the medium from the one extreme optical state to an intermediate gray state different from the final gray state, and thereafter applying to the medium an alternating current pulse which drives the medium from the intermediate gray state to the final gray state.
22. A method according to claim 21 which is carried out using drive circuitry capable of applying only potential differences of +V, 0 and −V across the electro-optic medium, where V is an arbitrary drive voltage.
23. A method for addressing a bistable electro-optic display having a plurality of pixels arranged in a plurality of rows and a plurality of columns, a plurality of row electrodes each associated with one of the plurality of rows, a plurality of column electrodes each associated with one of the plurality of columns, and drive means arranged to select each of the row electrodes in turn and to apply to the column electrodes during the selection of any given row electrode voltages chosen so as to address the pixels in the row associated with the selected row electrode and write one row of a desired image on to the display, the method comprising:
writing a first image to the display;
receiving data representing a second image to be written to the display;
comparing the first and second images and dividing the rows of the display into a first set, in which at least one pixel of the row differs between the first and second images, and a second set, in which no pixel of the row differs between the first and second images; and
writing the second image by sequentially selecting only the row electrodes associated with the first set of rows, and applying voltages to the column electrodes to write only the first set of rows, thereby forming the second image to the display.
24. An electro-optic display having a plurality of pixels, at least one of the pixels comprising a plurality of sub-pixels differing from each other in area, the display comprising drive means arranged to change the optical state of the sub-pixels independently of one another.
25. An electro-optic display according to claim 24 wherein at least two of the sub-pixels differ in area by substantially a factor of two.
US11/611,324 1999-04-30 2006-12-15 Methods for driving electro-optic displays, and apparatus for use therein Abandoned US20070091418A1 (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
US11/611,324 US20070091418A1 (en) 1999-04-30 2006-12-15 Methods for driving electro-optic displays, and apparatus for use therein
US11/751,879 US20080024482A1 (en) 2002-06-13 2007-05-22 Methods for driving electro-optic displays
US14/680,121 US9966018B2 (en) 2002-06-13 2015-04-07 Methods for driving electro-optic displays
US14/816,226 US10319314B2 (en) 1999-04-30 2015-08-03 Methods for driving electro-optic displays, and apparatus for use therein

Applications Claiming Priority (13)

Application Number Priority Date Filing Date Title
US13179099P 1999-04-30 1999-04-30
US09/520,743 US6504524B1 (en) 2000-03-08 2000-03-08 Addressing methods for displays having zero time-average field
US09/561,424 US6531997B1 (en) 1999-04-30 2000-04-28 Methods for addressing electrophoretic displays
US31900701P 2001-11-20 2001-11-20
US31901001P 2001-11-21 2001-11-21
US31903401P 2001-12-18 2001-12-18
US31903701P 2001-12-20 2001-12-20
US31904001P 2001-12-21 2001-12-21
US31931502P 2002-06-13 2002-06-13
US31932102P 2002-06-18 2002-06-18
US10/065,795 US7012600B2 (en) 1999-04-30 2002-11-20 Methods for driving bistable electro-optic displays, and apparatus for use therein
US10/249,973 US7193625B2 (en) 1999-04-30 2003-05-23 Methods for driving electro-optic displays, and apparatus for use therein
US11/611,324 US20070091418A1 (en) 1999-04-30 2006-12-15 Methods for driving electro-optic displays, and apparatus for use therein

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
US10/249,973 Division US7193625B2 (en) 1995-07-20 2003-05-23 Methods for driving electro-optic displays, and apparatus for use therein

Related Child Applications (2)

Application Number Title Priority Date Filing Date
US11/751,879 Continuation-In-Part US20080024482A1 (en) 2002-06-13 2007-05-22 Methods for driving electro-optic displays
US14/816,226 Division US10319314B2 (en) 1999-04-30 2015-08-03 Methods for driving electro-optic displays, and apparatus for use therein

Publications (1)

Publication Number Publication Date
US20070091418A1 true US20070091418A1 (en) 2007-04-26

Family

ID=37985061

Family Applications (3)

Application Number Title Priority Date Filing Date
US10/249,973 Expired - Lifetime US7193625B2 (en) 1995-07-20 2003-05-23 Methods for driving electro-optic displays, and apparatus for use therein
US11/611,324 Abandoned US20070091418A1 (en) 1999-04-30 2006-12-15 Methods for driving electro-optic displays, and apparatus for use therein
US14/816,226 Expired - Lifetime US10319314B2 (en) 1999-04-30 2015-08-03 Methods for driving electro-optic displays, and apparatus for use therein

Family Applications Before (1)

Application Number Title Priority Date Filing Date
US10/249,973 Expired - Lifetime US7193625B2 (en) 1995-07-20 2003-05-23 Methods for driving electro-optic displays, and apparatus for use therein

Family Applications After (1)

Application Number Title Priority Date Filing Date
US14/816,226 Expired - Lifetime US10319314B2 (en) 1999-04-30 2015-08-03 Methods for driving electro-optic displays, and apparatus for use therein

Country Status (1)

Country Link
US (3) US7193625B2 (en)

Cited By (134)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20070002084A1 (en) * 2005-07-04 2007-01-04 Semiconductor Energy Laboratory Co., Ltd. Display device, electronic device and method of driving display device
US20070211331A1 (en) * 2006-03-08 2007-09-13 E Ink Corporation Electro-optic displays, and materials and methods for production thereof
US20070223079A1 (en) * 2006-03-22 2007-09-27 E Ink Corporation Electro-optic media produced using ink jet printing
US20070262949A1 (en) * 2003-07-03 2007-11-15 Guofu Zhou Electrophoretic display with reduction of remnant voltages by selection of characteristics of inter-picture potential differences
US20070286975A1 (en) * 2003-11-05 2007-12-13 E Ink Corporation Electro-optic displays, and materials for use therein
US20080013155A1 (en) * 2006-07-11 2008-01-17 E Ink Corporation Electrophoretic medium and display with improved image stability
US20080013156A1 (en) * 2006-07-13 2008-01-17 E Ink Corporation Particles for use in electrophoretic displays
US20080023332A1 (en) * 2003-03-25 2008-01-31 E Ink Corporation Processes for the production of electrophoretic displays
US20080024429A1 (en) * 2006-07-25 2008-01-31 E Ink Corporation Electrophoretic displays using gaseous fluids
US20080129667A1 (en) * 2004-03-31 2008-06-05 E Ink Corporation Methods for driving electro-optic displays
US20080137176A1 (en) * 2006-12-07 2008-06-12 E Ink Corporation Components and methods for use in electro-optic displays
US20080174853A1 (en) * 2007-01-22 2008-07-24 E Ink Corporation Multi-layer sheet for use in electro-optic displays
US20080211833A1 (en) * 2007-01-29 2008-09-04 Seiko Epson Corporation Drive Method For A Display Device, Drive Device, Display Device, And Electronic Device
US20080218839A1 (en) * 2003-11-05 2008-09-11 E Ink Corporation Electro-optic displays, and materials for use therein
US20080273132A1 (en) * 2007-05-01 2008-11-06 Yu-Chen Hsu Electronic-Ink Display Panel
US20080291129A1 (en) * 2007-05-21 2008-11-27 E Ink Corporation Methods for driving video electro-optic displays
US20080316582A1 (en) * 2006-03-08 2008-12-25 E Ink Corporation Electro-optic displays, and materials and methods for production thereof
US20090004442A1 (en) * 2007-06-28 2009-01-01 E Ink Corporation Processes for the production of electro-optic displays, and color filters for use therein
US20090109519A1 (en) * 2007-03-06 2009-04-30 E Ink Corporation Materials for use in electrophoretic displays
US7649674B2 (en) 2002-06-10 2010-01-19 E Ink Corporation Electro-optic display with edge seal
US7679814B2 (en) 2001-04-02 2010-03-16 E Ink Corporation Materials for use in electrophoretic displays
US7688497B2 (en) 2007-01-22 2010-03-30 E Ink Corporation Multi-layer sheet for use in electro-optic displays
US20100225995A1 (en) * 2009-03-03 2010-09-09 E Ink Corporation Electro-optic displays, and color filters for use therein
US7848006B2 (en) 1995-07-20 2010-12-07 E Ink Corporation Electrophoretic displays with controlled amounts of pigment
US7999787B2 (en) 1995-07-20 2011-08-16 E Ink Corporation Methods for driving electrophoretic displays using dielectrophoretic forces
US20110216101A1 (en) * 2010-03-08 2011-09-08 Seiko Epson Corporation Driving method of electrophoretic display device, and controller
US20110216100A1 (en) * 2010-03-04 2011-09-08 Seiko Epson Corporation Driving method of electrophoretic display device, and controller
US20110216099A1 (en) * 2010-03-03 2011-09-08 Seiko Epson Corporation Driving method of electrophoretic display device, and controller
US8034209B2 (en) 2007-06-29 2011-10-11 E Ink Corporation Electro-optic displays, and materials and methods for production thereof
US8040594B2 (en) 1997-08-28 2011-10-18 E Ink Corporation Multi-color electrophoretic displays
US8049947B2 (en) 2002-06-10 2011-11-01 E Ink Corporation Components and methods for use in electro-optic displays
US8054526B2 (en) 2008-03-21 2011-11-08 E Ink Corporation Electro-optic displays, and color filters for use therein
US8270064B2 (en) 2009-02-09 2012-09-18 E Ink Corporation Electrophoretic particles, and processes for the production thereof
US8305341B2 (en) 1995-07-20 2012-11-06 E Ink Corporation Dielectrophoretic displays
US8314784B2 (en) 2008-04-11 2012-11-20 E Ink Corporation Methods for driving electro-optic displays
US8363299B2 (en) 2002-06-10 2013-01-29 E Ink Corporation Electro-optic displays, and processes for the production thereof
EP2555182A1 (en) 2007-02-02 2013-02-06 E Ink Corporation Electrophoretic displays having transparent electrode and conductor connected thereto
US8390301B2 (en) 2006-03-08 2013-03-05 E Ink Corporation Electro-optic displays, and materials and methods for production thereof
US8390918B2 (en) 2001-04-02 2013-03-05 E Ink Corporation Electrophoretic displays with controlled amounts of pigment
US8389381B2 (en) 2002-04-24 2013-03-05 E Ink Corporation Processes for forming backplanes for electro-optic displays
US8446664B2 (en) 2010-04-02 2013-05-21 E Ink Corporation Electrophoretic media, and materials for use therein
US20130235447A1 (en) * 2012-03-09 2013-09-12 E Ink Holdings Inc. Electrophoretic display panel and manufacturing method thereof
US8553012B2 (en) 2001-03-13 2013-10-08 E Ink Corporation Apparatus for displaying drawings
US8610988B2 (en) 2006-03-09 2013-12-17 E Ink Corporation Electro-optic display with edge seal
US8654436B1 (en) 2009-10-30 2014-02-18 E Ink Corporation Particles for use in electrophoretic displays
WO2014134504A1 (en) 2013-03-01 2014-09-04 E Ink Corporation Methods for driving electro-optic displays
US8854721B2 (en) 2002-06-10 2014-10-07 E Ink Corporation Components and testing methods for use in the production of electro-optic displays
US8902153B2 (en) 2007-08-03 2014-12-02 E Ink Corporation Electro-optic displays, and processes for their production
WO2015017624A1 (en) 2013-07-31 2015-02-05 E Ink Corporation Methods for driving electro-optic displays
WO2015017503A1 (en) 2013-07-30 2015-02-05 E Ink Corporation Methods for driving electro-optic displays
US20150138256A1 (en) * 2012-04-27 2015-05-21 Mitsubishi Pencil Company, Limited Electrophoretic display apparatus and drive method thereof
US9075280B2 (en) 2002-09-03 2015-07-07 E Ink Corporation Components and methods for use in electro-optic displays
US9196201B2 (en) 2012-03-26 2015-11-24 Seiko Epson Corporation Method for controlling electro-optic device, device for controlling electro-optic device, electro-optic device, and electronic apparatus
US9230492B2 (en) 2003-03-31 2016-01-05 E Ink Corporation Methods for driving electro-optic displays
US9262972B2 (en) 2012-07-25 2016-02-16 Seiko Epson Corporation Method for controlling electro-optic device, device for controlling electro-optic device, electro-optic device, and electronic apparatus
US9293511B2 (en) 1998-07-08 2016-03-22 E Ink Corporation Methods for achieving improved color in microencapsulated electrophoretic devices
WO2016191673A1 (en) 2015-05-27 2016-12-01 E Ink Corporation Methods and circuitry for driving display devices
US9513743B2 (en) 2012-06-01 2016-12-06 E Ink Corporation Methods for driving electro-optic displays
US9529240B2 (en) 2014-01-17 2016-12-27 E Ink Corporation Controlled polymeric material conductivity for use in a two-phase electrode layer
US9530363B2 (en) 2001-11-20 2016-12-27 E Ink Corporation Methods and apparatus for driving electro-optic displays
WO2017049020A1 (en) 2015-09-16 2017-03-23 E Ink Corporation Apparatus and methods for driving displays
US9620066B2 (en) 2010-02-02 2017-04-11 E Ink Corporation Method for driving electro-optic displays
WO2017062345A1 (en) 2015-10-06 2017-04-13 E Ink Corporation Improved low-temperature electrophoretic media
US9664978B2 (en) 2002-10-16 2017-05-30 E Ink Corporation Electrophoretic displays
US9672766B2 (en) 2003-03-31 2017-06-06 E Ink Corporation Methods for driving electro-optic displays
US9697778B2 (en) 2013-05-14 2017-07-04 E Ink Corporation Reverse driving pulses in electrophoretic displays
US9721495B2 (en) 2013-02-27 2017-08-01 E Ink Corporation Methods for driving electro-optic displays
WO2017139323A1 (en) 2016-02-08 2017-08-17 E Ink Corporation Methods and apparatus for operating an electro-optic display in white mode
US9752034B2 (en) 2015-11-11 2017-09-05 E Ink Corporation Functionalized quinacridone pigments
EP3220383A1 (en) 2012-02-01 2017-09-20 E Ink Corporation Methods for driving electro-optic displays
CN107657931A (en) * 2017-11-13 2018-02-02 深圳市华星光电技术有限公司 Improve the method and LCD display of LCD display colour cast
US9921451B2 (en) 2014-09-10 2018-03-20 E Ink Corporation Colored electrophoretic displays
US9928810B2 (en) 2015-01-30 2018-03-27 E Ink Corporation Font control for electro-optic displays and related apparatus and methods
US9964831B2 (en) 2007-11-14 2018-05-08 E Ink Corporation Electro-optic assemblies, and adhesives and binders for use therein
US10037735B2 (en) 2012-11-16 2018-07-31 E Ink Corporation Active matrix display with dual driving modes
US10040954B2 (en) 2015-05-28 2018-08-07 E Ink California, Llc Electrophoretic medium comprising a mixture of charge control agents
US10048563B2 (en) 2003-11-05 2018-08-14 E Ink Corporation Electro-optic displays, and materials for use therein
US10062337B2 (en) 2015-10-12 2018-08-28 E Ink California, Llc Electrophoretic display device
WO2018160912A1 (en) 2017-03-03 2018-09-07 E Ink Corporation Electro-optic displays and driving methods
WO2018164942A1 (en) 2017-03-06 2018-09-13 E Ink Corporation Method for rendering color images
US10115354B2 (en) 2009-09-15 2018-10-30 E Ink California, Llc Display controller system
US10163406B2 (en) 2015-02-04 2018-12-25 E Ink Corporation Electro-optic displays displaying in dark mode and light mode, and related apparatus and methods
US10175550B2 (en) 2014-11-07 2019-01-08 E Ink Corporation Applications of electro-optic displays
US10197883B2 (en) 2015-01-05 2019-02-05 E Ink Corporation Electro-optic displays, and methods for driving same
CN109448615A (en) * 2018-11-28 2019-03-08 江西兴泰科技有限公司 A kind of automatic adjustment method of Electronic Paper drive waveforms
US10270939B2 (en) 2016-05-24 2019-04-23 E Ink Corporation Method for rendering color images
US10276109B2 (en) 2016-03-09 2019-04-30 E Ink Corporation Method for driving electro-optic displays
US10282033B2 (en) 2012-06-01 2019-05-07 E Ink Corporation Methods for updating electro-optic displays when drawing or writing on the display
WO2019126623A1 (en) 2017-12-22 2019-06-27 E Ink Corporation Electro-optic displays, and methods for driving same
US10353266B2 (en) 2014-09-26 2019-07-16 E Ink Corporation Color sets for low resolution dithering in reflective color displays
WO2019144097A1 (en) 2018-01-22 2019-07-25 E Ink Corporation Electro-optic displays, and methods for driving same
US10380931B2 (en) 2013-10-07 2019-08-13 E Ink California, Llc Driving methods for color display device
US10388233B2 (en) 2015-08-31 2019-08-20 E Ink Corporation Devices and techniques for electronically erasing a drawing device
US10444592B2 (en) 2017-03-09 2019-10-15 E Ink Corporation Methods and systems for transforming RGB image data to a reduced color set for electro-optic displays
US10527899B2 (en) 2016-05-31 2020-01-07 E Ink Corporation Backplanes for electro-optic displays
WO2020018508A1 (en) 2018-07-17 2020-01-23 E Ink California, Llc Electro-optic displays and driving methods
WO2020033175A1 (en) 2018-08-10 2020-02-13 E Ink California, Llc Switchable light-collimating layer including bistable electrophoretic fluid
WO2020033787A1 (en) 2018-08-10 2020-02-13 E Ink California, Llc Driving waveforms for switchable light-collimating layer including bistable electrophoretic fluid
US10573257B2 (en) 2017-05-30 2020-02-25 E Ink Corporation Electro-optic displays
US10573222B2 (en) 2015-01-05 2020-02-25 E Ink Corporation Electro-optic displays, and methods for driving same
US10593272B2 (en) 2016-03-09 2020-03-17 E Ink Corporation Drivers providing DC-balanced refresh sequences for color electrophoretic displays
WO2020060960A1 (en) 2018-09-17 2020-03-26 E Ink Corporation Backplanes with hexagonal and triangular electrodes
US10657869B2 (en) 2014-09-10 2020-05-19 E Ink Corporation Methods for driving color electrophoretic displays
US10726798B2 (en) 2003-03-31 2020-07-28 E Ink Corporation Methods for operating electro-optic displays
US10726760B2 (en) 2013-10-07 2020-07-28 E Ink California, Llc Driving methods to produce a mixed color state for an electrophoretic display
US10795233B2 (en) 2015-11-18 2020-10-06 E Ink Corporation Electro-optic displays
US10796623B2 (en) 2015-04-27 2020-10-06 E Ink Corporation Methods and apparatuses for driving display systems
US10803813B2 (en) 2015-09-16 2020-10-13 E Ink Corporation Apparatus and methods for driving displays
US10832622B2 (en) 2017-04-04 2020-11-10 E Ink Corporation Methods for driving electro-optic displays
US10882042B2 (en) 2017-10-18 2021-01-05 E Ink Corporation Digital microfluidic devices including dual substrates with thin-film transistors and capacitive sensing
US11004409B2 (en) 2013-10-07 2021-05-11 E Ink California, Llc Driving methods for color display device
US11030936B2 (en) 2012-02-01 2021-06-08 E Ink Corporation Methods and apparatus for operating an electro-optic display in white mode
US11062663B2 (en) 2018-11-30 2021-07-13 E Ink California, Llc Electro-optic displays and driving methods
US11087644B2 (en) 2015-08-19 2021-08-10 E Ink Corporation Displays intended for use in architectural applications
US11250794B2 (en) 2004-07-27 2022-02-15 E Ink Corporation Methods for driving electrophoretic displays using dielectrophoretic forces
US11257445B2 (en) 2019-11-18 2022-02-22 E Ink Corporation Methods for driving electro-optic displays
US11314098B2 (en) 2018-08-10 2022-04-26 E Ink California, Llc Switchable light-collimating layer with reflector
US11422427B2 (en) 2017-12-19 2022-08-23 E Ink Corporation Applications of electro-optic displays
US11423852B2 (en) 2017-09-12 2022-08-23 E Ink Corporation Methods for driving electro-optic displays
US11450262B2 (en) 2020-10-01 2022-09-20 E Ink Corporation Electro-optic displays, and methods for driving same
US11460722B2 (en) 2019-05-10 2022-10-04 E Ink Corporation Colored electrophoretic displays
US11511096B2 (en) 2018-10-15 2022-11-29 E Ink Corporation Digital microfluidic delivery device
US11520202B2 (en) 2020-06-11 2022-12-06 E Ink Corporation Electro-optic displays, and methods for driving same
US11568786B2 (en) 2020-05-31 2023-01-31 E Ink Corporation Electro-optic displays, and methods for driving same
WO2023043714A1 (en) 2021-09-14 2023-03-23 E Ink Corporation Coordinated top electrode - drive electrode voltages for switching optical state of electrophoretic displays using positive and negative voltages of different magnitudes
WO2023122142A1 (en) 2021-12-22 2023-06-29 E Ink Corporation Methods for driving electro-optic displays
WO2023129533A1 (en) 2021-12-27 2023-07-06 E Ink Corporation Methods for measuring electrical properties of electro-optic displays
WO2023129692A1 (en) 2021-12-30 2023-07-06 E Ink California, Llc Methods for driving electro-optic displays
WO2023132958A1 (en) 2022-01-04 2023-07-13 E Ink Corporation Electrophoretic media comprising electrophoretic particles and a combination of charge control agents
US11721295B2 (en) 2017-09-12 2023-08-08 E Ink Corporation Electro-optic displays, and methods for driving same
WO2023211867A1 (en) 2022-04-27 2023-11-02 E Ink Corporation Color displays configured to convert rgb image data for display on advanced color electronic paper
US11869451B2 (en) 2021-11-05 2024-01-09 E Ink Corporation Multi-primary display mask-based dithering with low blooming sensitivity
WO2024044119A1 (en) 2022-08-25 2024-02-29 E Ink Corporation Transitional driving modes for impulse balancing when switching between global color mode and direct update mode for electrophoretic displays
US11922893B2 (en) 2022-12-12 2024-03-05 E Ink Corporation High voltage driving using top plane switching with zero voltage frames between driving frames

Families Citing this family (70)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7193625B2 (en) 1999-04-30 2007-03-20 E Ink Corporation Methods for driving electro-optic displays, and apparatus for use therein
US7411719B2 (en) 1995-07-20 2008-08-12 E Ink Corporation Electrophoretic medium and process for the production thereof
US8139050B2 (en) 1995-07-20 2012-03-20 E Ink Corporation Addressing schemes for electronic displays
US8115729B2 (en) 1999-05-03 2012-02-14 E Ink Corporation Electrophoretic display element with filler particles
US6982178B2 (en) 2002-06-10 2006-01-03 E Ink Corporation Components and methods for use in electro-optic displays
US7535624B2 (en) 2001-07-09 2009-05-19 E Ink Corporation Electro-optic display and materials for use therein
US8593396B2 (en) 2001-11-20 2013-11-26 E Ink Corporation Methods and apparatus for driving electro-optic displays
US8558783B2 (en) 2001-11-20 2013-10-15 E Ink Corporation Electro-optic displays with reduced remnant voltage
US9412314B2 (en) 2001-11-20 2016-08-09 E Ink Corporation Methods for driving electro-optic displays
US7952557B2 (en) 2001-11-20 2011-05-31 E Ink Corporation Methods and apparatus for driving electro-optic displays
US8125501B2 (en) 2001-11-20 2012-02-28 E Ink Corporation Voltage modulated driver circuits for electro-optic displays
US7110164B2 (en) 2002-06-10 2006-09-19 E Ink Corporation Electro-optic displays, and processes for the production thereof
US7583427B2 (en) * 2002-06-10 2009-09-01 E Ink Corporation Components and methods for use in electro-optic displays
US9470950B2 (en) 2002-06-10 2016-10-18 E Ink Corporation Electro-optic displays, and processes for the production thereof
US20110199671A1 (en) * 2002-06-13 2011-08-18 E Ink Corporation Methods for driving electrophoretic displays using dielectrophoretic forces
US20080024482A1 (en) 2002-06-13 2008-01-31 E Ink Corporation Methods for driving electro-optic displays
WO2004023195A2 (en) 2002-09-03 2004-03-18 E Ink Corporation Electro-optic displays
US8174490B2 (en) 2003-06-30 2012-05-08 E Ink Corporation Methods for driving electrophoretic displays
EP1647002A1 (en) * 2003-07-15 2006-04-19 Koninklijke Philips Electronics N.V. Electrophoretic display unit
EP1658604A1 (en) * 2003-08-22 2006-05-24 Koninklijke Philips Electronics N.V. Grayscale generation method for electrophoretic display panel
JP2007507729A (en) * 2003-09-29 2007-03-29 コーニンクレッカ フィリップス エレクトロニクス エヌ ヴィ Driving scheme for black and white mode and transition mode from black and white mode to grayscale mode in bistable displays
KR20060088882A (en) * 2003-09-29 2006-08-07 코닌클리케 필립스 일렉트로닉스 엔.브이. A bi-stable display with accurate greyscale and natural image update
US7616227B2 (en) * 2003-10-02 2009-11-10 Real D Hardware based interdigitation
US7616228B2 (en) * 2003-10-02 2009-11-10 Real D Hardware based interdigitation
US7432895B2 (en) * 2003-10-02 2008-10-07 Industrial Technology Research Institute Drive for active matrix cholesteric liquid crystal display
US8319759B2 (en) 2003-10-08 2012-11-27 E Ink Corporation Electrowetting displays
US7672040B2 (en) 2003-11-05 2010-03-02 E Ink Corporation Electro-optic displays, and materials for use therein
WO2007002452A2 (en) 2005-06-23 2007-01-04 E Ink Corporation Edge seals and processes for electro-optic displays
KR101182771B1 (en) * 2005-09-23 2012-09-14 삼성전자주식회사 Liquid crystal display panel and method of driving the same and liquid crystal display apparatus using the same
WO2007048096A2 (en) 2005-10-18 2007-04-26 E Ink Corporation Components for electro-optic displays
US20080043318A1 (en) * 2005-10-18 2008-02-21 E Ink Corporation Color electro-optic displays, and processes for the production thereof
US20070091417A1 (en) * 2005-10-25 2007-04-26 E Ink Corporation Electrophoretic media and displays with improved binder
US20070176854A1 (en) * 2006-01-25 2007-08-02 Element Labs, Inc. Irregular screen format for led and oled systems
EP2024955A4 (en) * 2006-05-26 2010-09-15 E Ink Corp Methods for driving electro-optic displays
US7492497B2 (en) * 2006-08-02 2009-02-17 E Ink Corporation Multi-layer light modulator
EP2064589A4 (en) 2006-09-18 2010-06-09 E Ink Corp Color electro-optic displays
US7477444B2 (en) * 2006-09-22 2009-01-13 E Ink Corporation & Air Products And Chemical, Inc. Electro-optic display and materials for use therein
US7986450B2 (en) 2006-09-22 2011-07-26 E Ink Corporation Electro-optic display and materials for use therein
JP5456480B2 (en) * 2006-11-28 2014-03-26 コーニンクレッカ フィリップス エヌ ヴェ Method for driving an electronic device having an element containing particles
TWI368808B (en) * 2007-11-23 2012-07-21 Chunghwa Picture Tubes Ltd Display
US8373649B2 (en) * 2008-04-11 2013-02-12 Seiko Epson Corporation Time-overlapping partial-panel updating of a bistable electro-optic display
US8234507B2 (en) 2009-01-13 2012-07-31 Metrologic Instruments, Inc. Electronic-ink display device employing a power switching mechanism automatically responsive to predefined states of device configuration
US8457013B2 (en) 2009-01-13 2013-06-04 Metrologic Instruments, Inc. Wireless dual-function network device dynamically switching and reconfiguring from a wireless network router state of operation into a wireless network coordinator state of operation in a wireless communication network
US8819568B1 (en) * 2009-02-06 2014-08-26 Amazon Technologies, Inc. Electronic paper display updates
TWI409747B (en) * 2009-06-03 2013-09-21 Au Optronics Corp Method for updating display image of electrophoretic display panel and electrophoretic display apparatus using the same
TWI484275B (en) 2010-05-21 2015-05-11 E Ink Corp Electro-optic display, method for driving the same and microcavity electrophoretic display
KR20120011786A (en) * 2010-07-19 2012-02-08 주식회사 나노브릭 Display method and device
WO2012012875A1 (en) 2010-07-26 2012-02-02 Kaleidoflex Technologies Inc. Method, apparatus, and system for forming filter elements on display substrates
US20130125910A1 (en) 2011-11-18 2013-05-23 Avon Products, Inc. Use of Electrophoretic Microcapsules in a Cosmetic Composition
JP2013186409A (en) * 2012-03-09 2013-09-19 Fuji Xerox Co Ltd Driving device for image display medium, image display device and driving program
US9501996B2 (en) 2013-09-26 2016-11-22 Amazon Technologies, Inc. Control method
JP2015169902A (en) * 2014-03-10 2015-09-28 大日本印刷株式会社 Method for driving reflection-type display
CN107223278B (en) 2015-02-04 2019-05-28 伊英克公司 Electro-optic displays and relevant device and method with reduced residual voltage
US10198983B2 (en) 2015-06-02 2019-02-05 E Ink Corporation Apparatus for driving displays
US11657774B2 (en) 2015-09-16 2023-05-23 E Ink Corporation Apparatus and methods for driving displays
WO2017146787A1 (en) 2016-02-23 2017-08-31 E Ink Corporation Methods and apparatus for driving electro-optic displays
US11353693B2 (en) * 2017-02-06 2022-06-07 Paul Atkinson Polymorphic electro-optic displays
US11404013B2 (en) 2017-05-30 2022-08-02 E Ink Corporation Electro-optic displays with resistors for discharging remnant charges
WO2020226990A1 (en) * 2019-05-07 2020-11-12 E Ink Corporation Driving methods for a variable light transmission device
EP4059006A4 (en) 2019-11-14 2023-12-06 E Ink Corporation Methods for driving electro-optic displays
JP2023541843A (en) 2020-09-15 2023-10-04 イー インク コーポレイション Four-particle electrophoretic medium provides fast, high-contrast optical state switching
WO2022060700A1 (en) 2020-09-15 2022-03-24 E Ink Corporation Improved driving voltages for advanced color electrophoretic displays and displays with improved driving voltages
US11846863B2 (en) 2020-09-15 2023-12-19 E Ink Corporation Coordinated top electrode—drive electrode voltages for switching optical state of electrophoretic displays using positive and negative voltages of different magnitudes
KR20230078791A (en) 2020-11-02 2023-06-02 이 잉크 코포레이션 Driving sequences for removing previous state information from color electrophoretic displays
CN116490913A (en) 2020-11-02 2023-07-25 伊英克公司 Enhanced push-pull (EPP) waveforms for implementing primary color sets in multi-color electrophoretic displays
US11721296B2 (en) 2020-11-02 2023-08-08 E Ink Corporation Method and apparatus for rendering color images
WO2022125500A1 (en) 2020-12-08 2022-06-16 E Ink Corporation Methods for driving electro-optic displays
US11830448B2 (en) 2021-11-04 2023-11-28 E Ink Corporation Methods for driving electro-optic displays
WO2023164078A1 (en) 2022-02-25 2023-08-31 E Ink Corporation Electro-optic displays with edge seal components and methods of making the same
WO2023211699A1 (en) 2022-04-27 2023-11-02 E Ink Corporation Electro-optic display stacks with segmented electrodes and methods of making the same

Citations (94)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3560956A (en) * 1967-07-05 1971-02-02 Sinnott Co Image forming apparatus
US3668106A (en) * 1970-04-09 1972-06-06 Matsushita Electric Ind Co Ltd Electrophoretic display device
US3792308A (en) * 1970-06-08 1974-02-12 Matsushita Electric Ind Co Ltd Electrophoretic display device of the luminescent type
US3870517A (en) * 1969-10-18 1975-03-11 Matsushita Electric Ind Co Ltd Color image reproduction sheet employed in photoelectrophoretic imaging
US4430648A (en) * 1980-01-22 1984-02-07 Citizen Watch Company Limited Combination matrix array display and memory system
US4450440A (en) * 1981-12-24 1984-05-22 U.S. Philips Corporation Construction of an epid bar graph
US4741604A (en) * 1985-02-01 1988-05-03 Kornfeld Cary D Electrode arrays for cellular displays
US4746917A (en) * 1986-07-14 1988-05-24 Copytele, Inc. Method and apparatus for operating an electrophoretic display between a display and a non-display mode
US4833464A (en) * 1987-09-14 1989-05-23 Copytele, Inc. Electrophoretic information display (EPID) apparatus employing grey scale capability
US5181016A (en) * 1991-01-15 1993-01-19 The United States Of America As Represented By The United States Department Of Energy Micro-valve pump light valve display
US5223115A (en) * 1991-05-13 1993-06-29 Copytele, Inc. Electrophoretic display with single character erasure
US5280280A (en) * 1991-05-24 1994-01-18 Robert Hotto DC integrating display driver employing pixel status memories
US5293528A (en) * 1992-02-25 1994-03-08 Copytele, Inc. Electrophoretic display panel and associated methods providing single pixel erase capability
US5302235A (en) * 1989-05-01 1994-04-12 Copytele, Inc. Dual anode flat panel electrophoretic display apparatus
US5412398A (en) * 1992-02-25 1995-05-02 Copytele, Inc. Electrophoretic display panel and associated methods for blinking displayed characters
US5499038A (en) * 1991-11-21 1996-03-12 Copytele, Inc. Method of operation for reducing power, increasing life and improving performance of EPIDs
US5717515A (en) * 1995-12-15 1998-02-10 Xerox Corporation Canted electric fields for addressing a twisting ball display
US5717283A (en) * 1996-01-03 1998-02-10 Xerox Corporation Display sheet with a plurality of hourglass shaped capsules containing marking means responsive to external fields
US5739801A (en) * 1995-12-15 1998-04-14 Xerox Corporation Multithreshold addressing of a twisting ball display
US5745094A (en) * 1994-12-28 1998-04-28 International Business Machines Corporation Electrophoretic display
US5760761A (en) * 1995-12-15 1998-06-02 Xerox Corporation Highlight color twisting ball display
US5866284A (en) * 1997-05-28 1999-02-02 Hewlett-Packard Company Print method and apparatus for re-writable medium
US5892504A (en) * 1991-07-17 1999-04-06 U.S. Philips Corporation Matrix display device and its method of operation
US5896117A (en) * 1995-09-29 1999-04-20 Samsung Electronics, Co., Ltd. Drive circuit with reduced kickback voltage for liquid crystal display
US6017584A (en) * 1995-07-20 2000-01-25 E Ink Corporation Multi-color electrophoretic displays and materials for making the same
US6034807A (en) * 1998-10-28 2000-03-07 Memsolutions, Inc. Bistable paper white direct view display
US6046716A (en) * 1996-12-19 2000-04-04 Colorado Microdisplay, Inc. Display system having electrode modulation to alter a state of an electro-optic layer
US6052106A (en) * 1994-02-25 2000-04-18 Universita Degli Studi Di Roma Sapienza Control method for a ferroelectric liquid crystal matrix panel
US6055180A (en) * 1997-06-17 2000-04-25 Thin Film Electronics Asa Electrically addressable passive device, method for electrical addressing of the same and uses of the device and the method
US6054071A (en) * 1998-01-28 2000-04-25 Xerox Corporation Poled electrets for gyricon-based electric-paper displays
US6055091A (en) * 1996-06-27 2000-04-25 Xerox Corporation Twisting-cylinder display
US6057814A (en) * 1993-05-24 2000-05-02 Display Science, Inc. Electrostatic video display drive circuitry and displays incorporating same
US6064410A (en) * 1998-03-03 2000-05-16 Eastman Kodak Company Printing continuous tone images on receivers having field-driven particles
US6067185A (en) * 1997-08-28 2000-05-23 E Ink Corporation Process for creating an encapsulated electrophoretic display
US6172798B1 (en) * 1998-04-27 2001-01-09 E Ink Corporation Shutter mode microencapsulated electrophoretic display
US6177921B1 (en) * 1997-08-28 2001-01-23 E Ink Corporation Printable electrode structures for displays
US6184856B1 (en) * 1998-09-16 2001-02-06 International Business Machines Corporation Transmissive electrophoretic display with laterally adjacent color cells
US6211998B1 (en) * 1998-11-25 2001-04-03 Xerox Corporation Magnetic unlatching and addressing of a gyricon display
US6225971B1 (en) * 1998-09-16 2001-05-01 International Business Machines Corporation Reflective electrophoretic display with laterally adjacent color cells using an absorbing panel
US6232950B1 (en) * 1997-08-28 2001-05-15 E Ink Corporation Rear electrode structures for displays
US6239896B1 (en) * 1998-06-01 2001-05-29 Canon Kabushiki Kaisha Electrophotographic display device and driving method therefor
US6336385B1 (en) * 2000-08-03 2002-01-08 Lo-Pin Wang Bicycle tool set
US20020005832A1 (en) * 2000-06-22 2002-01-17 Seiko Epson Corporation Method and circuit for driving electrophoretic display, electrophoretic display and electronic device using same
US6348908B1 (en) * 1998-09-15 2002-02-19 Xerox Corporation Ambient energy powered display
US6359605B1 (en) * 1998-06-12 2002-03-19 U.S. Philips Corporation Active matrix electroluminescent display devices
US20020033793A1 (en) * 2000-09-21 2002-03-21 Fuji Xerox Co., Ltd. Image display medium driving method and image display device
US20020033784A1 (en) * 2000-09-08 2002-03-21 Fuji Xerox Co., Ltd. Display medium driving method
US6373461B1 (en) * 1999-01-29 2002-04-16 Seiko Epson Corporation Piezoelectric transducer and electrophoretic ink display apparatus using piezoelectric transducer
US6376828B1 (en) * 1998-10-07 2002-04-23 E Ink Corporation Illumination system for nonemissive electronic displays
US6377387B1 (en) * 1999-04-06 2002-04-23 E Ink Corporation Methods for producing droplets for use in capsule-based electrophoretic displays
US6392786B1 (en) * 1999-07-01 2002-05-21 E Ink Corporation Electrophoretic medium provided with spacers
US20020060321A1 (en) * 2000-07-14 2002-05-23 Kazlas Peter T. Minimally- patterned, thin-film semiconductor devices for display applications
US20020063661A1 (en) * 2000-11-29 2002-05-30 E Ink Corporation Addressing schemes for electronic displays
US6504524B1 (en) * 2000-03-08 2003-01-07 E Ink Corporation Addressing methods for displays having zero time-average field
US6506438B2 (en) * 1998-12-15 2003-01-14 E Ink Corporation Method for printing of transistor arrays on plastic substrates
US20030011560A1 (en) * 1998-08-27 2003-01-16 E Ink Corporation Electrophoretic display comprising optical biasing element
US6512354B2 (en) * 1998-07-08 2003-01-28 E Ink Corporation Method and apparatus for sensing the state of an electrophoretic display
US20030020844A1 (en) * 2001-07-27 2003-01-30 Albert Jonathan D. Microencapsulated electrophoretic display with integrated driver
US6515649B1 (en) * 1995-07-20 2003-02-04 E Ink Corporation Suspended particle displays and materials for making the same
US6518949B2 (en) * 1998-04-10 2003-02-11 E Ink Corporation Electronic displays using organic-based field effect transistors
US6521489B2 (en) * 1999-07-21 2003-02-18 E Ink Corporation Preferred methods for producing electrical circuit elements used to control an electronic display
US6531997B1 (en) * 1999-04-30 2003-03-11 E Ink Corporation Methods for addressing electrophoretic displays
US6538801B2 (en) * 1996-07-19 2003-03-25 E Ink Corporation Electrophoretic displays using nanoparticles
US20030058223A1 (en) * 2001-09-21 2003-03-27 Tracy James L. Adaptable keypad and button mechanism therefor
US20030063076A1 (en) * 2001-09-28 2003-04-03 Fuji Xerox Co., Ltd. Image display device
US6545291B1 (en) * 1999-08-31 2003-04-08 E Ink Corporation Transistor design for use in the construction of an electronically driven display
US20030081305A1 (en) * 2001-10-29 2003-05-01 Jerry Chung Electrophoretic display with holding electrodes
US6672921B1 (en) * 2000-03-03 2004-01-06 Sipix Imaging, Inc. Manufacturing process for electrophoretic display
USD485294S1 (en) * 1998-07-22 2004-01-13 E Ink Corporation Electrode structure for an electronic display
US6680725B1 (en) * 1995-07-20 2004-01-20 E Ink Corporation Methods of manufacturing electronically addressable displays
US20040012839A1 (en) * 2002-05-23 2004-01-22 E Ink Corporation Capsules, materials for use therein and electrophoretic media and displays containing such capsules
US20040014265A1 (en) * 2002-04-24 2004-01-22 E Ink Corporation Processes for forming backplanes for electro-optic displays
US20040027327A1 (en) * 2002-06-10 2004-02-12 E Ink Corporation Components and methods for use in electro-optic displays
US6693620B1 (en) * 1999-05-03 2004-02-17 E Ink Corporation Threshold addressing of electrophoretic displays
US6704133B2 (en) * 1998-03-18 2004-03-09 E-Ink Corporation Electro-optic display overlays and systems for addressing such displays
US20040051934A1 (en) * 2002-08-29 2004-03-18 Fuji Xerox Co., Ltd. Image display medium and image writing device
US6710540B1 (en) * 1995-07-20 2004-03-23 E Ink Corporation Electrostatically-addressable electrophoretic display
US6719471B1 (en) * 2003-03-10 2004-04-13 Instituto De Higiene Y Servicios Dentales, S.A. Toothbrush incorporating a toothpaste reservoir
US6721083B2 (en) * 1996-07-19 2004-04-13 E Ink Corporation Electrophoretic displays using nanoparticles
US6724519B1 (en) * 1998-12-21 2004-04-20 E-Ink Corporation Protective electrodes for electrophoretic displays
US6727881B1 (en) * 1995-07-20 2004-04-27 E Ink Corporation Encapsulated electrophoretic displays and methods and materials for making the same
US6738050B2 (en) * 1998-05-12 2004-05-18 E Ink Corporation Microencapsulated electrophoretic electrostatically addressed media for drawing device applications
US6839158B2 (en) * 1997-08-28 2005-01-04 E Ink Corporation Encapsulated electrophoretic displays having a monolayer of capsules and materials and methods for making the same
US20050001812A1 (en) * 1999-04-30 2005-01-06 E Ink Corporation Methods for driving bistable electro-optic displays, and apparatus for use therein
US20050001810A1 (en) * 2001-09-19 2005-01-06 Gaku Yakushiji Particles and device for displaying image
US6842657B1 (en) * 1999-04-09 2005-01-11 E Ink Corporation Reactive formation of dielectric layers and protection of organic layers in organic semiconductor device fabrication
US6842279B2 (en) * 2002-06-27 2005-01-11 E Ink Corporation Illumination system for nonemissive electronic displays
US20050007653A1 (en) * 2003-03-27 2005-01-13 E Ink Corporation Electro-optic assemblies, and materials for use therein
US20050035941A1 (en) * 1995-07-20 2005-02-17 Albert Jonathan D. Retroreflective electrophoretic displaya and materials for making the same
US6864875B2 (en) * 1998-04-10 2005-03-08 E Ink Corporation Full color reflective display with multichromatic sub-pixels
US6866760B2 (en) * 1998-08-27 2005-03-15 E Ink Corporation Electrophoretic medium and process for the production thereof
US6870661B2 (en) * 2001-05-15 2005-03-22 E Ink Corporation Electrophoretic displays containing magnetic particles
US7050040B2 (en) * 2002-12-18 2006-05-23 Xerox Corporation Switching of two-particle electrophoretic display media with a combination of AC and DC electric field for contrast enhancement
US20070085819A1 (en) * 2004-10-14 2007-04-19 Koninklijke Philips Electronics, N.V. Look-up tables with graylevel transition waveforms for bi-stable display

Family Cites Families (157)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3892568A (en) 1969-04-23 1975-07-01 Matsushita Electric Ind Co Ltd Electrophoretic image reproduction process
US3767392A (en) 1970-04-15 1973-10-23 Matsushita Electric Ind Co Ltd Electrophoretic light image reproduction process
JPS4917079B1 (en) 1970-12-21 1974-04-26
US3765011A (en) 1971-06-10 1973-10-09 Zenith Radio Corp Flat panel image display
GB1458045A (en) 1973-08-15 1976-12-08 Secr Defence Display systems
US4045327A (en) 1974-08-28 1977-08-30 Matsushita Electric Industrial Co., Ltd. Electrophoretic matrix panel
US4041481A (en) 1974-10-05 1977-08-09 Matsushita Electric Industrial Co., Ltd. Scanning apparatus for an electrophoretic matrix display panel
US3980476A (en) 1975-01-27 1976-09-14 Xerox Corporation Imaging system
DE2523763A1 (en) 1975-05-28 1976-12-09 Siemens Ag Liquid crystal display device - has matrix of row and column conducting traces on circuit boards between which liquid crystal is held
GB1513999A (en) * 1976-12-22 1978-06-14 Ibm Electrochromic display device
JPS5688193A (en) 1979-12-19 1981-07-17 Citizen Watch Co Ltd Display unit
US4305807A (en) 1980-03-13 1981-12-15 Burroughs Corporation Electrophoretic display device using a liquid crystal as a threshold device
US4418346A (en) 1981-05-20 1983-11-29 Batchelder J Samuel Method and apparatus for providing a dielectrophoretic display of visual information
US4529271A (en) * 1982-03-12 1985-07-16 At&T Bell Laboratories Matrix addressed bistable liquid crystal display
DE3379612D1 (en) * 1982-09-21 1989-05-18 Fujitsu Ltd Method of driving a matrix type display
JPS59155832A (en) 1983-02-24 1984-09-05 Seiko Epson Corp Half tone displaying liquid crystal panel
US4643528A (en) * 1985-03-18 1987-02-17 Manchester R & D Partnership Encapsulated liquid crystal and filler material
JPH07104530B2 (en) 1987-02-05 1995-11-13 株式会社村上開明堂 EC antiglare mirror driving method and driving circuit thereof
US4870398A (en) 1987-10-08 1989-09-26 Tektronix, Inc. Drive waveform for ferroelectric displays
US4947159A (en) 1988-04-18 1990-08-07 501 Copytele, Inc. Power supply apparatus capable of multi-mode operation for an electrophoretic display panel
JP2527477B2 (en) 1988-06-14 1996-08-21 シャープ株式会社 Picture element display
US4947157A (en) 1988-10-03 1990-08-07 501 Copytele, Inc. Apparatus and methods for pulsing the electrodes of an electrophoretic display for achieving faster display operation
US5066946A (en) 1989-07-03 1991-11-19 Copytele, Inc. Electrophoretic display panel with selective line erasure
JPH0823644B2 (en) 1989-09-04 1996-03-06 トヨタ自動車株式会社 Driving method for electrophoretic display device
JP2705235B2 (en) 1989-09-08 1998-01-28 トヨタ自動車株式会社 Driving method of electrophoretic display element
US5254981A (en) 1989-09-15 1993-10-19 Copytele, Inc. Electrophoretic display employing gray scale capability utilizing area modulation
JP2854065B2 (en) 1990-01-18 1999-02-03 エヌオーケー株式会社 Driving device for electrophoretic display panel
JP3087305B2 (en) 1990-03-05 2000-09-11 株式会社ニコン Stage equipment
GB2247973B (en) 1990-09-11 1994-07-27 Stc Plc Co-ordinate addressing of liquid crystal cells
US5177475A (en) * 1990-12-19 1993-01-05 Xerox Corporation Control of liquid crystal devices
US5847798A (en) * 1991-05-02 1998-12-08 Kent State University Polymer stabilized black-white cholesteric reflective display
US5689282A (en) 1991-07-09 1997-11-18 U.S. Philips Corporation Display device with compensation for stray capacitance
ES2101036T3 (en) 1991-07-24 1997-07-01 Canon Kk INFORMATION DISPLAY.
JPH0568196A (en) 1991-09-06 1993-03-19 Seiko Instr Inc Joint conversion correlator type range finder/automatic focusing device and its driving system
JP3029896B2 (en) 1991-09-20 2000-04-10 株式会社豊田中央研究所 Matrix type liquid crystal display device and method of driving the liquid crystal display device
US5467217A (en) 1991-11-01 1995-11-14 Research Frontiers Incorporated Light valve suspensions and films containing UV absorbers and light valves containing the same
US5266937A (en) 1991-11-25 1993-11-30 Copytele, Inc. Method for writing data to an electrophoretic display panel
JPH05173194A (en) 1991-12-20 1993-07-13 Nippon Mektron Ltd Electrophoretic display device
CA2094343A1 (en) 1992-07-17 1994-01-18 Gerald L. Klein Method and apparatus for displaying capillary electrophoresis data
JPH06233131A (en) 1993-01-29 1994-08-19 Fuji Film Micro Device Kk Gamma correction for digital image
JP3489169B2 (en) * 1993-02-25 2004-01-19 セイコーエプソン株式会社 Driving method of liquid crystal display device
JP3276205B2 (en) 1993-06-18 2002-04-22 富士通機電株式会社 Writing method of phase change type liquid crystal display
US6061039A (en) * 1993-06-21 2000-05-09 Ryan; Paul Globally-addressable matrix of electronic circuit elements
EP0721638A4 (en) 1993-10-01 1997-04-09 Copytele Inc Electrophoretic display panel with selective character addressability
JP3476241B2 (en) 1994-02-25 2003-12-10 株式会社半導体エネルギー研究所 Display method of active matrix type display device
JPH08510575A (en) 1994-03-18 1996-11-05 フィリップス エレクトロニクス ネムローゼ フェン ノートシャップ Active matrix display device and driving method thereof
US6137467A (en) 1995-01-03 2000-10-24 Xerox Corporation Optically sensitive electric paper
US6154190A (en) 1995-02-17 2000-11-28 Kent State University Dynamic drive methods and apparatus for a bistable liquid crystal display
US5699074A (en) * 1995-03-24 1997-12-16 Teletransaction, Inc. Addressing device and method for rapid video response in a bistable liquid crystal display
JPH0916116A (en) 1995-06-26 1997-01-17 Nok Corp Electrophoretic display device
US6118426A (en) 1995-07-20 2000-09-12 E Ink Corporation Transducers and indicators having printed displays
US6664944B1 (en) 1995-07-20 2003-12-16 E-Ink Corporation Rear electrode structures for electrophoretic displays
US6639578B1 (en) 1995-07-20 2003-10-28 E Ink Corporation Flexible displays
US7193625B2 (en) 1999-04-30 2007-03-20 E Ink Corporation Methods for driving electro-optic displays, and apparatus for use therein
US6120839A (en) 1995-07-20 2000-09-19 E Ink Corporation Electro-osmotic displays and materials for making the same
US7106296B1 (en) * 1995-07-20 2006-09-12 E Ink Corporation Electronic book with multiple page displays
US6120588A (en) 1996-07-19 2000-09-19 E Ink Corporation Electronically addressable microencapsulated ink and display thereof
US6459418B1 (en) 1995-07-20 2002-10-01 E Ink Corporation Displays combining active and non-active inks
US6262706B1 (en) 1995-07-20 2001-07-17 E Ink Corporation Retroreflective electrophoretic displays and materials for making the same
JP3277106B2 (en) 1995-08-02 2002-04-22 シャープ株式会社 Display drive
US5582700A (en) 1995-10-16 1996-12-10 Zikon Corporation Electrophoretic display utilizing phase separation of liquids
FR2741165B1 (en) * 1995-11-10 1998-01-30 Ist Naz Fisica Della Materia BISTABLE DISPLAY DEVICE BASED ON NEMATIC LIQUID CRYSTALS AUTHORIZING SHADES OF GRAY
JP3991367B2 (en) 1995-12-28 2007-10-17 セイコーエプソン株式会社 Electrophoresis device
JPH09230391A (en) 1996-02-26 1997-09-05 Fujikura Ltd Re-dispersion of electric field arrangeable particle
US5808783A (en) 1996-06-27 1998-09-15 Xerox Corporation High reflectance gyricon display
JPH1090662A (en) 1996-07-12 1998-04-10 Tektronix Inc Plasma address liquid crystal display device and display panel operating method
US6323989B1 (en) 1996-07-19 2001-11-27 E Ink Corporation Electrophoretic displays using nanoparticles
ATE356369T1 (en) 1996-07-19 2007-03-15 E Ink Corp ELECTRONICALLY ADDRESSABLE MICRO-ENCAPSULED INK
US5930026A (en) 1996-10-25 1999-07-27 Massachusetts Institute Of Technology Nonemissive displays and piezoelectric power supplies therefor
EP0851260A3 (en) 1996-12-16 1998-09-09 Ngk Insulators, Ltd. Display device
US5777782A (en) 1996-12-24 1998-07-07 Xerox Corporation Auxiliary optics for a twisting ball display
US5933203A (en) * 1997-01-08 1999-08-03 Advanced Display Systems, Inc. Apparatus for and method of driving a cholesteric liquid crystal flat panel display
US6301038B1 (en) 1997-02-06 2001-10-09 University College Dublin Electrochromic system
US6980196B1 (en) 1997-03-18 2005-12-27 Massachusetts Institute Of Technology Printable electronic display
US5961804A (en) 1997-03-18 1999-10-05 Massachusetts Institute Of Technology Microencapsulated electrophoretic display
JPH116993A (en) 1997-06-17 1999-01-12 Denso Corp Matrix type liquid crystal display device
KR19990006953A (en) 1997-06-19 1999-01-25 가미야 마사시 Liquid crystal display device having matrix type electrode structure
GB9717597D0 (en) 1997-08-21 1997-10-22 Sharp Kk Liquid crystal device
US6300932B1 (en) 1997-08-28 2001-10-09 E Ink Corporation Electrophoretic displays with luminescent particles and materials for making the same
WO1999010768A1 (en) 1997-08-28 1999-03-04 E-Ink Corporation Novel addressing schemes for electrophoretic displays
US6825829B1 (en) 1997-08-28 2004-11-30 E Ink Corporation Adhesive backed displays
US6252564B1 (en) * 1997-08-28 2001-06-26 E Ink Corporation Tiled displays
US6822782B2 (en) 2001-05-15 2004-11-23 E Ink Corporation Electrophoretic particles and processes for the production thereof
JPH1184339A (en) 1997-09-05 1999-03-26 Canon Inc Display device
JP3719317B2 (en) 1997-09-30 2005-11-24 ソニー株式会社 Interpolation method, interpolation circuit, and image display device
US6462837B1 (en) 1998-03-05 2002-10-08 Ricoh Company, Ltd. Gray-scale conversion based on SIMD processor
US6753999B2 (en) 1998-03-18 2004-06-22 E Ink Corporation Electrophoretic displays in portable devices and systems for addressing such displays
WO1999047970A1 (en) 1998-03-18 1999-09-23 E-Ink Corporation Electrophoretic displays and systems for addressing such displays
US6081285A (en) * 1998-04-28 2000-06-27 Eastman Kodak Company Forming images on receivers having field-driven particles and conducting layer
US6241921B1 (en) * 1998-05-15 2001-06-05 Massachusetts Institute Of Technology Heterogeneous display elements and methods for their fabrication
DE69907744T2 (en) 1998-06-22 2003-11-20 E Ink Corp METHOD FOR ADDRESSING MICROCAPSULATED DISPLAY MEDIA
US20030102858A1 (en) * 1998-07-08 2003-06-05 E Ink Corporation Method and apparatus for determining properties of an electrophoretic display
ATE276536T1 (en) 1998-07-08 2004-10-15 E Ink Corp METHOD FOR IMPROVING COLOR RENDERING IN ELECTROPHORETIC DEVICES USING MICROCAPSULES
ATE215255T1 (en) 1998-07-22 2002-04-15 E Ink Corp ELECTRONIC DISPLAY
US6271823B1 (en) 1998-09-16 2001-08-07 International Business Machines Corporation Reflective electrophoretic display with laterally adjacent color cells using a reflective panel
US6144361A (en) 1998-09-16 2000-11-07 International Business Machines Corporation Transmissive electrophoretic display with vertical electrodes
JP2000172200A (en) 1998-09-29 2000-06-23 Canon Inc Display element and color display element
JP4061734B2 (en) 1998-09-30 2008-03-19 ブラザー工業株式会社 Display medium display method and display device
US6262833B1 (en) 1998-10-07 2001-07-17 E Ink Corporation Capsules for electrophoretic displays and methods for making the same
US6128124A (en) 1998-10-16 2000-10-03 Xerox Corporation Additive color electric paper without registration or alignment of individual elements
AU1811300A (en) 1998-11-02 2000-05-22 E-Ink Corporation Broadcast system for display devices made of electronic ink
US6097531A (en) 1998-11-25 2000-08-01 Xerox Corporation Method of making uniformly magnetized elements for a gyricon display
US6147791A (en) 1998-11-25 2000-11-14 Xerox Corporation Gyricon displays utilizing rotating elements and magnetic latching
JP2000228284A (en) 1998-12-01 2000-08-15 Sanyo Electric Co Ltd Color el display device
US6312304B1 (en) 1998-12-15 2001-11-06 E Ink Corporation Assembly of microencapsulated electronic displays
JP2000180887A (en) 1998-12-18 2000-06-30 Minolta Co Ltd Device and method for displaying information
WO2000036560A1 (en) 1998-12-18 2000-06-22 E Ink Corporation Electronic ink display media for security and authentication
AU2591400A (en) 1998-12-22 2000-07-12 E-Ink Corporation Method of manufacturing of a discrete electronic device
JP3837948B2 (en) 1999-01-29 2006-10-25 セイコーエプソン株式会社 Electrophoretic ink display device
US6327072B1 (en) 1999-04-06 2001-12-04 E Ink Corporation Microcell electrophoretic displays
JP2000292772A (en) 1999-04-08 2000-10-20 Sony Corp Method of driving liquid crystal device and liquid crystal device
US6498114B1 (en) 1999-04-09 2002-12-24 E Ink Corporation Method for forming a patterned semiconductor film
US7038655B2 (en) 1999-05-03 2006-05-02 E Ink Corporation Electrophoretic ink composed of particles with field dependent mobilities
CA2373142A1 (en) 1999-05-03 2000-11-09 Russell J. Wilcox Display unit for electronic shelf price label system
US7030412B1 (en) 1999-05-05 2006-04-18 E Ink Corporation Minimally-patterned semiconductor devices for display applications
JP2002543625A (en) 1999-05-05 2002-12-17 イー−インク コーポレイション Minimal patterned semiconductor devices for display applications
JP4126851B2 (en) * 1999-07-21 2008-07-30 富士ゼロックス株式会社 Image display medium, image forming method, and image forming apparatus
WO2001007961A1 (en) 1999-07-21 2001-02-01 E Ink Corporation Use of a storage capacitor to enhance the performance of an active matrix driven electronic display
US6320565B1 (en) 1999-08-17 2001-11-20 Philips Electronics North America Corporation DAC driver circuit with pixel resetting means and color electro-optic display device and system incorporating same
AU7094400A (en) 1999-08-31 2001-03-26 E-Ink Corporation A solvent annealing process for forming a thin semiconductor film with advantageous properties
US6421033B1 (en) 1999-09-30 2002-07-16 Innovative Technology Licensing, Llc Current-driven emissive display addressing and fabrication scheme
EP1500969A1 (en) 1999-10-11 2005-01-26 University College Dublin Compound and its use in electrochromic devices
JP4112144B2 (en) 1999-12-28 2008-07-02 株式会社リコー Display medium and writing device
EP1130568A3 (en) 2000-03-01 2003-09-10 Minolta Co., Ltd. Liquid crystal display device
US6788449B2 (en) 2000-03-03 2004-09-07 Sipix Imaging, Inc. Electrophoretic display and novel process for its manufacture
JP2003531487A (en) 2000-04-18 2003-10-21 イー−インク コーポレイション Process for manufacturing thin film transistor
US7893435B2 (en) 2000-04-18 2011-02-22 E Ink Corporation Flexible electronic circuits and displays including a backplane comprising a patterned metal foil having a plurality of apertures extending therethrough
CN1197044C (en) 2000-05-26 2005-04-13 精工爱普生株式会社 Display and recorded medium
JP3475938B2 (en) 2000-05-26 2003-12-10 セイコーエプソン株式会社 Electro-optical device driving method, electro-optical device driving circuit, electro-optical device, and electronic apparatus
JP2001350430A (en) 2000-06-09 2001-12-21 Mitsubishi Electric Corp Display device
JP3750565B2 (en) * 2000-06-22 2006-03-01 セイコーエプソン株式会社 Electrophoretic display device driving method, driving circuit, and electronic apparatus
US6816147B2 (en) 2000-08-17 2004-11-09 E Ink Corporation Bistable electro-optic display, and method for addressing same
JP2002333870A (en) 2000-10-31 2002-11-22 Matsushita Electric Ind Co Ltd Liquid crystal display device, el display device and drive method therefor and display pattern evaluation method of subpixel
EP1340360A2 (en) 2000-12-05 2003-09-03 E Ink Corporation Portable electronic apparatus with additional electro-optical display
WO2002073572A2 (en) 2001-03-13 2002-09-19 E Ink Corporation Apparatus for displaying drawings
JP3819721B2 (en) 2001-03-21 2006-09-13 株式会社東芝 Electrophoretic display device
US7170670B2 (en) 2001-04-02 2007-01-30 E Ink Corporation Electrophoretic medium and display with improved image stability
US6580545B2 (en) 2001-04-19 2003-06-17 E Ink Corporation Electrochromic-nanoparticle displays
CN2483794Y (en) 2001-05-14 2002-03-27 凌巨科技股份有限公司 Panel driving module
JP4061863B2 (en) 2001-06-20 2008-03-19 富士ゼロックス株式会社 Image display device and display driving method
JP4134543B2 (en) 2001-06-26 2008-08-20 富士ゼロックス株式会社 Image display device and display driving method
ATE349028T1 (en) 2001-07-09 2007-01-15 E Ink Corp ELECTRO-OPTICAL DISPLAY AND ADHESIVE COMPOSITION
ATE549659T1 (en) 2001-07-09 2012-03-15 E Ink Corp ELECTRO-OPTICAL DISPLAY DEVICE WITH LAMINATE ADHESIVE LAYER
US6819471B2 (en) 2001-08-16 2004-11-16 E Ink Corporation Light modulation by frustration of total internal reflection
JP4785300B2 (en) 2001-09-07 2011-10-05 株式会社半導体エネルギー研究所 Electrophoretic display device, display device, and electronic device
US6825970B2 (en) 2001-09-14 2004-11-30 E Ink Corporation Methods for addressing electro-optic materials
WO2003050607A1 (en) * 2001-12-13 2003-06-19 E Ink Corporation Electrophoretic electronic displays with films having a low index of refraction
US6900851B2 (en) 2002-02-08 2005-05-31 E Ink Corporation Electro-optic displays and optical systems for addressing such displays
US6950220B2 (en) 2002-03-18 2005-09-27 E Ink Corporation Electro-optic displays, and methods for driving same
KR100867286B1 (en) 2002-04-24 2008-11-06 이 잉크 코포레이션 Electronic displays
AU2003235215A1 (en) 2002-04-26 2003-11-10 Bridgestone Corporation Particle for image display and its apparatus
WO2004017135A2 (en) 2002-08-06 2004-02-26 E Ink Corporation Protection of electro-optic displays against thermal effects
US8129655B2 (en) 2002-09-03 2012-03-06 E Ink Corporation Electrophoretic medium with gaseous suspending fluid
WO2004023195A2 (en) 2002-09-03 2004-03-18 E Ink Corporation Electro-optic displays
AU2003299673A1 (en) 2002-12-16 2004-07-22 E Ink Corporation Backplanes for electro-optic displays
US7432907B2 (en) 2003-03-04 2008-10-07 Canon Kabushiki Kaisha Driving method of electrophoretic display device
US7339715B2 (en) 2003-03-25 2008-03-04 E Ink Corporation Processes for the production of electrophoretic displays

Patent Citations (99)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3560956A (en) * 1967-07-05 1971-02-02 Sinnott Co Image forming apparatus
US3870517A (en) * 1969-10-18 1975-03-11 Matsushita Electric Ind Co Ltd Color image reproduction sheet employed in photoelectrophoretic imaging
US3668106A (en) * 1970-04-09 1972-06-06 Matsushita Electric Ind Co Ltd Electrophoretic display device
US3792308A (en) * 1970-06-08 1974-02-12 Matsushita Electric Ind Co Ltd Electrophoretic display device of the luminescent type
US4430648A (en) * 1980-01-22 1984-02-07 Citizen Watch Company Limited Combination matrix array display and memory system
US4450440A (en) * 1981-12-24 1984-05-22 U.S. Philips Corporation Construction of an epid bar graph
US4741604A (en) * 1985-02-01 1988-05-03 Kornfeld Cary D Electrode arrays for cellular displays
US4746917A (en) * 1986-07-14 1988-05-24 Copytele, Inc. Method and apparatus for operating an electrophoretic display between a display and a non-display mode
US4833464A (en) * 1987-09-14 1989-05-23 Copytele, Inc. Electrophoretic information display (EPID) apparatus employing grey scale capability
US5302235A (en) * 1989-05-01 1994-04-12 Copytele, Inc. Dual anode flat panel electrophoretic display apparatus
US5181016A (en) * 1991-01-15 1993-01-19 The United States Of America As Represented By The United States Department Of Energy Micro-valve pump light valve display
US5223115A (en) * 1991-05-13 1993-06-29 Copytele, Inc. Electrophoretic display with single character erasure
US5280280A (en) * 1991-05-24 1994-01-18 Robert Hotto DC integrating display driver employing pixel status memories
US5892504A (en) * 1991-07-17 1999-04-06 U.S. Philips Corporation Matrix display device and its method of operation
US5499038A (en) * 1991-11-21 1996-03-12 Copytele, Inc. Method of operation for reducing power, increasing life and improving performance of EPIDs
US5293528A (en) * 1992-02-25 1994-03-08 Copytele, Inc. Electrophoretic display panel and associated methods providing single pixel erase capability
US5412398A (en) * 1992-02-25 1995-05-02 Copytele, Inc. Electrophoretic display panel and associated methods for blinking displayed characters
US6057814A (en) * 1993-05-24 2000-05-02 Display Science, Inc. Electrostatic video display drive circuitry and displays incorporating same
US6052106A (en) * 1994-02-25 2000-04-18 Universita Degli Studi Di Roma Sapienza Control method for a ferroelectric liquid crystal matrix panel
US5745094A (en) * 1994-12-28 1998-04-28 International Business Machines Corporation Electrophoretic display
US5872552A (en) * 1994-12-28 1999-02-16 International Business Machines Corporation Electrophoretic display
US6727881B1 (en) * 1995-07-20 2004-04-27 E Ink Corporation Encapsulated electrophoretic displays and methods and materials for making the same
US6710540B1 (en) * 1995-07-20 2004-03-23 E Ink Corporation Electrostatically-addressable electrophoretic display
US6680725B1 (en) * 1995-07-20 2004-01-20 E Ink Corporation Methods of manufacturing electronically addressable displays
US6515649B1 (en) * 1995-07-20 2003-02-04 E Ink Corporation Suspended particle displays and materials for making the same
US20050035941A1 (en) * 1995-07-20 2005-02-17 Albert Jonathan D. Retroreflective electrophoretic displaya and materials for making the same
US6017584A (en) * 1995-07-20 2000-01-25 E Ink Corporation Multi-color electrophoretic displays and materials for making the same
US5896117A (en) * 1995-09-29 1999-04-20 Samsung Electronics, Co., Ltd. Drive circuit with reduced kickback voltage for liquid crystal display
US5760761A (en) * 1995-12-15 1998-06-02 Xerox Corporation Highlight color twisting ball display
US5739801A (en) * 1995-12-15 1998-04-14 Xerox Corporation Multithreshold addressing of a twisting ball display
US5717515A (en) * 1995-12-15 1998-02-10 Xerox Corporation Canted electric fields for addressing a twisting ball display
US5717283A (en) * 1996-01-03 1998-02-10 Xerox Corporation Display sheet with a plurality of hourglass shaped capsules containing marking means responsive to external fields
US6055091A (en) * 1996-06-27 2000-04-25 Xerox Corporation Twisting-cylinder display
US6538801B2 (en) * 1996-07-19 2003-03-25 E Ink Corporation Electrophoretic displays using nanoparticles
US6721083B2 (en) * 1996-07-19 2004-04-13 E Ink Corporation Electrophoretic displays using nanoparticles
US6046716A (en) * 1996-12-19 2000-04-04 Colorado Microdisplay, Inc. Display system having electrode modulation to alter a state of an electro-optic layer
US5866284A (en) * 1997-05-28 1999-02-02 Hewlett-Packard Company Print method and apparatus for re-writable medium
US6055180A (en) * 1997-06-17 2000-04-25 Thin Film Electronics Asa Electrically addressable passive device, method for electrical addressing of the same and uses of the device and the method
US6232950B1 (en) * 1997-08-28 2001-05-15 E Ink Corporation Rear electrode structures for displays
US6535197B1 (en) * 1997-08-28 2003-03-18 E Ink Corporation Printable electrode structures for displays
US6177921B1 (en) * 1997-08-28 2001-01-23 E Ink Corporation Printable electrode structures for displays
US6392785B1 (en) * 1997-08-28 2002-05-21 E Ink Corporation Non-spherical cavity electrophoretic displays and materials for making the same
US6839158B2 (en) * 1997-08-28 2005-01-04 E Ink Corporation Encapsulated electrophoretic displays having a monolayer of capsules and materials and methods for making the same
US6067185A (en) * 1997-08-28 2000-05-23 E Ink Corporation Process for creating an encapsulated electrophoretic display
US6842167B2 (en) * 1997-08-28 2005-01-11 E Ink Corporation Rear electrode structures for displays
US6054071A (en) * 1998-01-28 2000-04-25 Xerox Corporation Poled electrets for gyricon-based electric-paper displays
US6064410A (en) * 1998-03-03 2000-05-16 Eastman Kodak Company Printing continuous tone images on receivers having field-driven particles
US6704133B2 (en) * 1998-03-18 2004-03-09 E-Ink Corporation Electro-optic display overlays and systems for addressing such displays
US6864875B2 (en) * 1998-04-10 2005-03-08 E Ink Corporation Full color reflective display with multichromatic sub-pixels
US6518949B2 (en) * 1998-04-10 2003-02-11 E Ink Corporation Electronic displays using organic-based field effect transistors
US6172798B1 (en) * 1998-04-27 2001-01-09 E Ink Corporation Shutter mode microencapsulated electrophoretic display
US6738050B2 (en) * 1998-05-12 2004-05-18 E Ink Corporation Microencapsulated electrophoretic electrostatically addressed media for drawing device applications
US6239896B1 (en) * 1998-06-01 2001-05-29 Canon Kabushiki Kaisha Electrophotographic display device and driving method therefor
US6359605B1 (en) * 1998-06-12 2002-03-19 U.S. Philips Corporation Active matrix electroluminescent display devices
US6512354B2 (en) * 1998-07-08 2003-01-28 E Ink Corporation Method and apparatus for sensing the state of an electrophoretic display
USD485294S1 (en) * 1998-07-22 2004-01-13 E Ink Corporation Electrode structure for an electronic display
US20030011560A1 (en) * 1998-08-27 2003-01-16 E Ink Corporation Electrophoretic display comprising optical biasing element
US6866760B2 (en) * 1998-08-27 2005-03-15 E Ink Corporation Electrophoretic medium and process for the production thereof
US6348908B1 (en) * 1998-09-15 2002-02-19 Xerox Corporation Ambient energy powered display
US6184856B1 (en) * 1998-09-16 2001-02-06 International Business Machines Corporation Transmissive electrophoretic display with laterally adjacent color cells
US6225971B1 (en) * 1998-09-16 2001-05-01 International Business Machines Corporation Reflective electrophoretic display with laterally adjacent color cells using an absorbing panel
US6376828B1 (en) * 1998-10-07 2002-04-23 E Ink Corporation Illumination system for nonemissive electronic displays
US6034807A (en) * 1998-10-28 2000-03-07 Memsolutions, Inc. Bistable paper white direct view display
US6211998B1 (en) * 1998-11-25 2001-04-03 Xerox Corporation Magnetic unlatching and addressing of a gyricon display
US6506438B2 (en) * 1998-12-15 2003-01-14 E Ink Corporation Method for printing of transistor arrays on plastic substrates
US6724519B1 (en) * 1998-12-21 2004-04-20 E-Ink Corporation Protective electrodes for electrophoretic displays
US6373461B1 (en) * 1999-01-29 2002-04-16 Seiko Epson Corporation Piezoelectric transducer and electrophoretic ink display apparatus using piezoelectric transducer
US6377387B1 (en) * 1999-04-06 2002-04-23 E Ink Corporation Methods for producing droplets for use in capsule-based electrophoretic displays
US6842657B1 (en) * 1999-04-09 2005-01-11 E Ink Corporation Reactive formation of dielectric layers and protection of organic layers in organic semiconductor device fabrication
US6531997B1 (en) * 1999-04-30 2003-03-11 E Ink Corporation Methods for addressing electrophoretic displays
US20050001812A1 (en) * 1999-04-30 2005-01-06 E Ink Corporation Methods for driving bistable electro-optic displays, and apparatus for use therein
US6693620B1 (en) * 1999-05-03 2004-02-17 E Ink Corporation Threshold addressing of electrophoretic displays
US6392786B1 (en) * 1999-07-01 2002-05-21 E Ink Corporation Electrophoretic medium provided with spacers
US6521489B2 (en) * 1999-07-21 2003-02-18 E Ink Corporation Preferred methods for producing electrical circuit elements used to control an electronic display
US6545291B1 (en) * 1999-08-31 2003-04-08 E Ink Corporation Transistor design for use in the construction of an electronically driven display
US6672921B1 (en) * 2000-03-03 2004-01-06 Sipix Imaging, Inc. Manufacturing process for electrophoretic display
US6504524B1 (en) * 2000-03-08 2003-01-07 E Ink Corporation Addressing methods for displays having zero time-average field
US20020005832A1 (en) * 2000-06-22 2002-01-17 Seiko Epson Corporation Method and circuit for driving electrophoretic display, electrophoretic display and electronic device using same
US6683333B2 (en) * 2000-07-14 2004-01-27 E Ink Corporation Fabrication of electronic circuit elements using unpatterned semiconductor layers
US20020060321A1 (en) * 2000-07-14 2002-05-23 Kazlas Peter T. Minimally- patterned, thin-film semiconductor devices for display applications
US6336385B1 (en) * 2000-08-03 2002-01-08 Lo-Pin Wang Bicycle tool set
US20020033784A1 (en) * 2000-09-08 2002-03-21 Fuji Xerox Co., Ltd. Display medium driving method
US20020033793A1 (en) * 2000-09-21 2002-03-21 Fuji Xerox Co., Ltd. Image display medium driving method and image display device
US20020063661A1 (en) * 2000-11-29 2002-05-30 E Ink Corporation Addressing schemes for electronic displays
US6870661B2 (en) * 2001-05-15 2005-03-22 E Ink Corporation Electrophoretic displays containing magnetic particles
US20030020844A1 (en) * 2001-07-27 2003-01-30 Albert Jonathan D. Microencapsulated electrophoretic display with integrated driver
US20050001810A1 (en) * 2001-09-19 2005-01-06 Gaku Yakushiji Particles and device for displaying image
US20030058223A1 (en) * 2001-09-21 2003-03-27 Tracy James L. Adaptable keypad and button mechanism therefor
US20030063076A1 (en) * 2001-09-28 2003-04-03 Fuji Xerox Co., Ltd. Image display device
US20030081305A1 (en) * 2001-10-29 2003-05-01 Jerry Chung Electrophoretic display with holding electrodes
US20040014265A1 (en) * 2002-04-24 2004-01-22 E Ink Corporation Processes for forming backplanes for electro-optic displays
US20040012839A1 (en) * 2002-05-23 2004-01-22 E Ink Corporation Capsules, materials for use therein and electrophoretic media and displays containing such capsules
US20040027327A1 (en) * 2002-06-10 2004-02-12 E Ink Corporation Components and methods for use in electro-optic displays
US6842279B2 (en) * 2002-06-27 2005-01-11 E Ink Corporation Illumination system for nonemissive electronic displays
US20040051934A1 (en) * 2002-08-29 2004-03-18 Fuji Xerox Co., Ltd. Image display medium and image writing device
US7050040B2 (en) * 2002-12-18 2006-05-23 Xerox Corporation Switching of two-particle electrophoretic display media with a combination of AC and DC electric field for contrast enhancement
US6719471B1 (en) * 2003-03-10 2004-04-13 Instituto De Higiene Y Servicios Dentales, S.A. Toothbrush incorporating a toothpaste reservoir
US20050007653A1 (en) * 2003-03-27 2005-01-13 E Ink Corporation Electro-optic assemblies, and materials for use therein
US20070085819A1 (en) * 2004-10-14 2007-04-19 Koninklijke Philips Electronics, N.V. Look-up tables with graylevel transition waveforms for bi-stable display

Cited By (245)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7999787B2 (en) 1995-07-20 2011-08-16 E Ink Corporation Methods for driving electrophoretic displays using dielectrophoretic forces
US8305341B2 (en) 1995-07-20 2012-11-06 E Ink Corporation Dielectrophoretic displays
US7848006B2 (en) 1995-07-20 2010-12-07 E Ink Corporation Electrophoretic displays with controlled amounts of pigment
US9268191B2 (en) 1997-08-28 2016-02-23 E Ink Corporation Multi-color electrophoretic displays
US8040594B2 (en) 1997-08-28 2011-10-18 E Ink Corporation Multi-color electrophoretic displays
US8441714B2 (en) 1997-08-28 2013-05-14 E Ink Corporation Multi-color electrophoretic displays
US9293511B2 (en) 1998-07-08 2016-03-22 E Ink Corporation Methods for achieving improved color in microencapsulated electrophoretic devices
US8553012B2 (en) 2001-03-13 2013-10-08 E Ink Corporation Apparatus for displaying drawings
US8390918B2 (en) 2001-04-02 2013-03-05 E Ink Corporation Electrophoretic displays with controlled amounts of pigment
US7679814B2 (en) 2001-04-02 2010-03-16 E Ink Corporation Materials for use in electrophoretic displays
US9530363B2 (en) 2001-11-20 2016-12-27 E Ink Corporation Methods and apparatus for driving electro-optic displays
US8389381B2 (en) 2002-04-24 2013-03-05 E Ink Corporation Processes for forming backplanes for electro-optic displays
US7649674B2 (en) 2002-06-10 2010-01-19 E Ink Corporation Electro-optic display with edge seal
US8854721B2 (en) 2002-06-10 2014-10-07 E Ink Corporation Components and testing methods for use in the production of electro-optic displays
US8049947B2 (en) 2002-06-10 2011-11-01 E Ink Corporation Components and methods for use in electro-optic displays
US8363299B2 (en) 2002-06-10 2013-01-29 E Ink Corporation Electro-optic displays, and processes for the production thereof
US8830560B2 (en) 2002-06-10 2014-09-09 E Ink Corporation Electro-optic display with edge seal
US8027081B2 (en) 2002-06-10 2011-09-27 E Ink Corporation Electro-optic display with edge seal
US8891155B2 (en) 2002-06-10 2014-11-18 E Ink Corporation Electro-optic display with edge seal
US20100039706A1 (en) * 2002-06-10 2010-02-18 E Ink Corporation Electro-optic display with edge seal
US9075280B2 (en) 2002-09-03 2015-07-07 E Ink Corporation Components and methods for use in electro-optic displays
US9664978B2 (en) 2002-10-16 2017-05-30 E Ink Corporation Electrophoretic displays
US10331005B2 (en) 2002-10-16 2019-06-25 E Ink Corporation Electrophoretic displays
US7910175B2 (en) 2003-03-25 2011-03-22 E Ink Corporation Processes for the production of electrophoretic displays
US20080023332A1 (en) * 2003-03-25 2008-01-31 E Ink Corporation Processes for the production of electrophoretic displays
US9672766B2 (en) 2003-03-31 2017-06-06 E Ink Corporation Methods for driving electro-optic displays
US9620067B2 (en) 2003-03-31 2017-04-11 E Ink Corporation Methods for driving electro-optic displays
US10726798B2 (en) 2003-03-31 2020-07-28 E Ink Corporation Methods for operating electro-optic displays
US9230492B2 (en) 2003-03-31 2016-01-05 E Ink Corporation Methods for driving electro-optic displays
US9152003B2 (en) 2003-05-12 2015-10-06 E Ink Corporation Electro-optic display with edge seal
US20070262949A1 (en) * 2003-07-03 2007-11-15 Guofu Zhou Electrophoretic display with reduction of remnant voltages by selection of characteristics of inter-picture potential differences
US9152004B2 (en) 2003-11-05 2015-10-06 E Ink Corporation Electro-optic displays, and materials for use therein
US20080218839A1 (en) * 2003-11-05 2008-09-11 E Ink Corporation Electro-optic displays, and materials for use therein
US20070286975A1 (en) * 2003-11-05 2007-12-13 E Ink Corporation Electro-optic displays, and materials for use therein
US8177942B2 (en) 2003-11-05 2012-05-15 E Ink Corporation Electro-optic displays, and materials for use therein
US10048563B2 (en) 2003-11-05 2018-08-14 E Ink Corporation Electro-optic displays, and materials for use therein
US10324354B2 (en) 2003-11-05 2019-06-18 E Ink Corporation Electro-optic displays, and materials for use therein
US10048564B2 (en) 2003-11-05 2018-08-14 E Ink Corporation Electro-optic displays, and materials for use therein
US9829764B2 (en) 2003-12-05 2017-11-28 E Ink Corporation Multi-color electrophoretic displays
US9740076B2 (en) 2003-12-05 2017-08-22 E Ink Corporation Multi-color electrophoretic displays
US8289250B2 (en) 2004-03-31 2012-10-16 E Ink Corporation Methods for driving electro-optic displays
US20080129667A1 (en) * 2004-03-31 2008-06-05 E Ink Corporation Methods for driving electro-optic displays
US11250794B2 (en) 2004-07-27 2022-02-15 E Ink Corporation Methods for driving electrophoretic displays using dielectrophoretic forces
US8154678B2 (en) 2005-07-04 2012-04-10 Semiconductor Energy Laboratory Co., Ltd. Display device, electronic device and method of driving display device
US20110141164A1 (en) * 2005-07-04 2011-06-16 Semiconductor Energy Laboratory Co., Ltd. Display Device, Electronic Device and Method of Driving Display Device
US20070002084A1 (en) * 2005-07-04 2007-01-04 Semiconductor Energy Laboratory Co., Ltd. Display device, electronic device and method of driving display device
US8587742B2 (en) 2005-07-04 2013-11-19 Semiconductor Energy Laboratory Co., Ltd. Display device, electronic device and method of driving display device
US7898623B2 (en) * 2005-07-04 2011-03-01 Semiconductor Energy Laboratory Co., Ltd. Display device, electronic device and method of driving display device
US8339530B2 (en) 2005-07-04 2012-12-25 Semiconductor Energy Laboratory Co., Ltd. Display device, electronic device and method of driving display device
US8390301B2 (en) 2006-03-08 2013-03-05 E Ink Corporation Electro-optic displays, and materials and methods for production thereof
US20070211331A1 (en) * 2006-03-08 2007-09-13 E Ink Corporation Electro-optic displays, and materials and methods for production thereof
US7733554B2 (en) 2006-03-08 2010-06-08 E Ink Corporation Electro-optic displays, and materials and methods for production thereof
US7843624B2 (en) 2006-03-08 2010-11-30 E Ink Corporation Electro-optic displays, and materials and methods for production thereof
US20080316582A1 (en) * 2006-03-08 2008-12-25 E Ink Corporation Electro-optic displays, and materials and methods for production thereof
US8610988B2 (en) 2006-03-09 2013-12-17 E Ink Corporation Electro-optic display with edge seal
US10444591B2 (en) 2006-03-22 2019-10-15 E Ink Corporation Electro-optic media produced using ink jet printing
US8830559B2 (en) 2006-03-22 2014-09-09 E Ink Corporation Electro-optic media produced using ink jet printing
US7952790B2 (en) 2006-03-22 2011-05-31 E Ink Corporation Electro-optic media produced using ink jet printing
US9164207B2 (en) 2006-03-22 2015-10-20 E Ink Corporation Electro-optic media produced using ink jet printing
US20070223079A1 (en) * 2006-03-22 2007-09-27 E Ink Corporation Electro-optic media produced using ink jet printing
US20110195629A1 (en) * 2006-03-22 2011-08-11 E Ink Corporation Electro-optic media produced using ink jet printing
US9910337B2 (en) 2006-03-22 2018-03-06 E Ink Corporation Electro-optic media produced using ink jet printing
US7903319B2 (en) 2006-07-11 2011-03-08 E Ink Corporation Electrophoretic medium and display with improved image stability
US20080013155A1 (en) * 2006-07-11 2008-01-17 E Ink Corporation Electrophoretic medium and display with improved image stability
US8199395B2 (en) 2006-07-13 2012-06-12 E Ink Corporation Particles for use in electrophoretic displays
US20080013156A1 (en) * 2006-07-13 2008-01-17 E Ink Corporation Particles for use in electrophoretic displays
US8018640B2 (en) 2006-07-13 2011-09-13 E Ink Corporation Particles for use in electrophoretic displays
US20080024429A1 (en) * 2006-07-25 2008-01-31 E Ink Corporation Electrophoretic displays using gaseous fluids
US20080137176A1 (en) * 2006-12-07 2008-06-12 E Ink Corporation Components and methods for use in electro-optic displays
US7649666B2 (en) 2006-12-07 2010-01-19 E Ink Corporation Components and methods for use in electro-optic displays
US7667886B2 (en) 2007-01-22 2010-02-23 E Ink Corporation Multi-layer sheet for use in electro-optic displays
US8009344B2 (en) 2007-01-22 2011-08-30 E Ink Corporation Multi-layer sheet for use in electro-optic displays
US20100118384A1 (en) * 2007-01-22 2010-05-13 E Ink Corporation Multi-layer sheet for use in electro-optic displays
US8498042B2 (en) 2007-01-22 2013-07-30 E Ink Corporation Multi-layer sheet for use in electro-optic displays
US7688497B2 (en) 2007-01-22 2010-03-30 E Ink Corporation Multi-layer sheet for use in electro-optic displays
US20080174853A1 (en) * 2007-01-22 2008-07-24 E Ink Corporation Multi-layer sheet for use in electro-optic displays
US20080211833A1 (en) * 2007-01-29 2008-09-04 Seiko Epson Corporation Drive Method For A Display Device, Drive Device, Display Device, And Electronic Device
US8044927B2 (en) * 2007-01-29 2011-10-25 Seiko Epson Corporation Drive method for a display device, drive device, display device, and electronic device
EP2555182A1 (en) 2007-02-02 2013-02-06 E Ink Corporation Electrophoretic displays having transparent electrode and conductor connected thereto
US9310661B2 (en) 2007-03-06 2016-04-12 E Ink Corporation Materials for use in electrophoretic displays
US9841653B2 (en) 2007-03-06 2017-12-12 E Ink Corporation Materials for use in electrophoretic displays
US7826129B2 (en) 2007-03-06 2010-11-02 E Ink Corporation Materials for use in electrophoretic displays
US20090109519A1 (en) * 2007-03-06 2009-04-30 E Ink Corporation Materials for use in electrophoretic displays
JP2008276153A (en) * 2007-05-01 2008-11-13 Genta Kagi Kogyo Kofun Yugenkoshi Electronic ink display panel
US8797255B2 (en) * 2007-05-01 2014-08-05 E Ink Holdings Inc. Electronic-ink display panel
US20080273132A1 (en) * 2007-05-01 2008-11-06 Yu-Chen Hsu Electronic-Ink Display Panel
US10319313B2 (en) 2007-05-21 2019-06-11 E Ink Corporation Methods for driving video electro-optic displays
US20080291129A1 (en) * 2007-05-21 2008-11-27 E Ink Corporation Methods for driving video electro-optic displays
US20090004442A1 (en) * 2007-06-28 2009-01-01 E Ink Corporation Processes for the production of electro-optic displays, and color filters for use therein
US9199441B2 (en) 2007-06-28 2015-12-01 E Ink Corporation Processes for the production of electro-optic displays, and color filters for use therein
US10527880B2 (en) 2007-06-28 2020-01-07 E Ink Corporation Process for the production of electro-optic displays, and color filters for use therein
US8034209B2 (en) 2007-06-29 2011-10-11 E Ink Corporation Electro-optic displays, and materials and methods for production thereof
US8728266B2 (en) 2007-06-29 2014-05-20 E Ink Corporation Electro-optic displays, and materials and methods for production thereof
US9554495B2 (en) 2007-06-29 2017-01-24 E Ink Corporation Electro-optic displays, and materials and methods for production thereof
US8902153B2 (en) 2007-08-03 2014-12-02 E Ink Corporation Electro-optic displays, and processes for their production
US9964831B2 (en) 2007-11-14 2018-05-08 E Ink Corporation Electro-optic assemblies, and adhesives and binders for use therein
US10036930B2 (en) 2007-11-14 2018-07-31 E Ink Corporation Electro-optic assemblies, and adhesives and binders for use therein
US8054526B2 (en) 2008-03-21 2011-11-08 E Ink Corporation Electro-optic displays, and color filters for use therein
US8314784B2 (en) 2008-04-11 2012-11-20 E Ink Corporation Methods for driving electro-optic displays
US8270064B2 (en) 2009-02-09 2012-09-18 E Ink Corporation Electrophoretic particles, and processes for the production thereof
US8441716B2 (en) 2009-03-03 2013-05-14 E Ink Corporation Electro-optic displays, and color filters for use therein
US8098418B2 (en) 2009-03-03 2012-01-17 E. Ink Corporation Electro-optic displays, and color filters for use therein
US20100225995A1 (en) * 2009-03-03 2010-09-09 E Ink Corporation Electro-optic displays, and color filters for use therein
US10115354B2 (en) 2009-09-15 2018-10-30 E Ink California, Llc Display controller system
US8654436B1 (en) 2009-10-30 2014-02-18 E Ink Corporation Particles for use in electrophoretic displays
US9881565B2 (en) 2010-02-02 2018-01-30 E Ink Corporation Method for driving electro-optic displays
US9620066B2 (en) 2010-02-02 2017-04-11 E Ink Corporation Method for driving electro-optic displays
CN102194414A (en) * 2010-03-03 2011-09-21 精工爱普生株式会社 Driving method of electrophoretic display device, and controller
US20110216099A1 (en) * 2010-03-03 2011-09-08 Seiko Epson Corporation Driving method of electrophoretic display device, and controller
US20110216100A1 (en) * 2010-03-04 2011-09-08 Seiko Epson Corporation Driving method of electrophoretic display device, and controller
US9343017B2 (en) * 2010-03-04 2016-05-17 Seiko Epson Corporation Driving method of electrophoretic display device, and controller
US9202417B2 (en) 2010-03-08 2015-12-01 Seiko Epson Corporation Driving method of electrophoretic display device, and controller
US20110216101A1 (en) * 2010-03-08 2011-09-08 Seiko Epson Corporation Driving method of electrophoretic display device, and controller
US8446664B2 (en) 2010-04-02 2013-05-21 E Ink Corporation Electrophoretic media, and materials for use therein
US11030936B2 (en) 2012-02-01 2021-06-08 E Ink Corporation Methods and apparatus for operating an electro-optic display in white mode
US11145261B2 (en) 2012-02-01 2021-10-12 E Ink Corporation Methods for driving electro-optic displays
EP3783597A1 (en) 2012-02-01 2021-02-24 E Ink Corporation Methods for driving electro-optic displays
EP3220383A1 (en) 2012-02-01 2017-09-20 E Ink Corporation Methods for driving electro-optic displays
US20140347717A1 (en) * 2012-03-09 2014-11-27 E Ink Holdings Inc. Electrophoretic display panel and manufacturing method thereof
US20130235447A1 (en) * 2012-03-09 2013-09-12 E Ink Holdings Inc. Electrophoretic display panel and manufacturing method thereof
US9207501B2 (en) * 2012-03-09 2015-12-08 E Ink Holdings Inc. Electrophoretic display panel and manufacturing method thereof
US9196201B2 (en) 2012-03-26 2015-11-24 Seiko Epson Corporation Method for controlling electro-optic device, device for controlling electro-optic device, electro-optic device, and electronic apparatus
US20150138256A1 (en) * 2012-04-27 2015-05-21 Mitsubishi Pencil Company, Limited Electrophoretic display apparatus and drive method thereof
US10282033B2 (en) 2012-06-01 2019-05-07 E Ink Corporation Methods for updating electro-optic displays when drawing or writing on the display
US9996195B2 (en) 2012-06-01 2018-06-12 E Ink Corporation Line segment update method for electro-optic displays
US9513743B2 (en) 2012-06-01 2016-12-06 E Ink Corporation Methods for driving electro-optic displays
US9262972B2 (en) 2012-07-25 2016-02-16 Seiko Epson Corporation Method for controlling electro-optic device, device for controlling electro-optic device, electro-optic device, and electronic apparatus
US10037735B2 (en) 2012-11-16 2018-07-31 E Ink Corporation Active matrix display with dual driving modes
US11145235B2 (en) 2013-02-27 2021-10-12 E Ink Corporation Methods for driving electro-optic displays
US11854456B2 (en) 2013-02-27 2023-12-26 E Ink Corporation Electro-optic displays and methods for driving the same
US9721495B2 (en) 2013-02-27 2017-08-01 E Ink Corporation Methods for driving electro-optic displays
US9495918B2 (en) 2013-03-01 2016-11-15 E Ink Corporation Methods for driving electro-optic displays
WO2014134504A1 (en) 2013-03-01 2014-09-04 E Ink Corporation Methods for driving electro-optic displays
US11250761B2 (en) 2013-03-01 2022-02-15 E Ink Corporation Methods for driving electro-optic displays
US10380954B2 (en) 2013-03-01 2019-08-13 E Ink Corporation Methods for driving electro-optic displays
US10242630B2 (en) 2013-05-14 2019-03-26 E Ink Corporation Color electrophoretic displays using same polarity reversing address pulse
US11195481B2 (en) 2013-05-14 2021-12-07 E Ink Corporation Color electrophoretic displays using same polarity reversing address pulse
US10475399B2 (en) 2013-05-14 2019-11-12 E Ink Corporation Color electrophoretic displays using same polarity reversing address pulse
US9697778B2 (en) 2013-05-14 2017-07-04 E Ink Corporation Reverse driving pulses in electrophoretic displays
WO2015017503A1 (en) 2013-07-30 2015-02-05 E Ink Corporation Methods for driving electro-optic displays
US9620048B2 (en) 2013-07-30 2017-04-11 E Ink Corporation Methods for driving electro-optic displays
WO2015017624A1 (en) 2013-07-31 2015-02-05 E Ink Corporation Methods for driving electro-optic displays
EP4156164A1 (en) 2013-07-31 2023-03-29 E Ink Corporation Methods for driving electro-optic displays
EP4156165A2 (en) 2013-07-31 2023-03-29 E Ink Corporation Methods for driving electro-optic displays
US11195480B2 (en) 2013-07-31 2021-12-07 E Ink Corporation Partial update driving methods for bistable electro-optic displays and display controllers using the same
US11004409B2 (en) 2013-10-07 2021-05-11 E Ink California, Llc Driving methods for color display device
US10726760B2 (en) 2013-10-07 2020-07-28 E Ink California, Llc Driving methods to produce a mixed color state for an electrophoretic display
US10380931B2 (en) 2013-10-07 2019-08-13 E Ink California, Llc Driving methods for color display device
US11217145B2 (en) 2013-10-07 2022-01-04 E Ink California, Llc Driving methods to produce a mixed color state for an electrophoretic display
US10151955B2 (en) 2014-01-17 2018-12-11 E Ink Corporation Controlled polymeric material conductivity for use in a two-phase electrode layer
US10795221B2 (en) 2014-01-17 2020-10-06 E Ink Corporation Methods for making two-phase light-transmissive electrode layer with controlled conductivity
US9529240B2 (en) 2014-01-17 2016-12-27 E Ink Corporation Controlled polymeric material conductivity for use in a two-phase electrode layer
US9921451B2 (en) 2014-09-10 2018-03-20 E Ink Corporation Colored electrophoretic displays
US10678111B2 (en) 2014-09-10 2020-06-09 E Ink Corporation Colored electrophoretic displays
US10657869B2 (en) 2014-09-10 2020-05-19 E Ink Corporation Methods for driving color electrophoretic displays
US11468855B2 (en) 2014-09-10 2022-10-11 E Ink Corporation Colored electrophoretic displays
EP3633662A1 (en) 2014-09-10 2020-04-08 E Ink Corporation Colored electrophoretic displays
US10509293B2 (en) 2014-09-10 2019-12-17 E Ink Corporation Colored electrophoretic displays
US10353266B2 (en) 2014-09-26 2019-07-16 E Ink Corporation Color sets for low resolution dithering in reflective color displays
US11402718B2 (en) 2014-09-26 2022-08-02 E Ink Corporation Color sets for low resolution dithering in reflective color displays
US10175550B2 (en) 2014-11-07 2019-01-08 E Ink Corporation Applications of electro-optic displays
US10976634B2 (en) 2014-11-07 2021-04-13 E Ink Corporation Applications of electro-optic displays
US10197883B2 (en) 2015-01-05 2019-02-05 E Ink Corporation Electro-optic displays, and methods for driving same
US10901285B2 (en) 2015-01-05 2021-01-26 E Ink Corporation Methods for driving electro-optic displays
US10551713B2 (en) 2015-01-05 2020-02-04 E Ink Corporation Electro-optic displays, and methods for driving same
US10573222B2 (en) 2015-01-05 2020-02-25 E Ink Corporation Electro-optic displays, and methods for driving same
US9928810B2 (en) 2015-01-30 2018-03-27 E Ink Corporation Font control for electro-optic displays and related apparatus and methods
US10163406B2 (en) 2015-02-04 2018-12-25 E Ink Corporation Electro-optic displays displaying in dark mode and light mode, and related apparatus and methods
US10796623B2 (en) 2015-04-27 2020-10-06 E Ink Corporation Methods and apparatuses for driving display systems
WO2016191673A1 (en) 2015-05-27 2016-12-01 E Ink Corporation Methods and circuitry for driving display devices
US10997930B2 (en) 2015-05-27 2021-05-04 E Ink Corporation Methods and circuitry for driving display devices
US11398197B2 (en) 2015-05-27 2022-07-26 E Ink Corporation Methods and circuitry for driving display devices
US10233339B2 (en) 2015-05-28 2019-03-19 E Ink California, Llc Electrophoretic medium comprising a mixture of charge control agents
US10040954B2 (en) 2015-05-28 2018-08-07 E Ink California, Llc Electrophoretic medium comprising a mixture of charge control agents
US11087644B2 (en) 2015-08-19 2021-08-10 E Ink Corporation Displays intended for use in architectural applications
US10388233B2 (en) 2015-08-31 2019-08-20 E Ink Corporation Devices and techniques for electronically erasing a drawing device
WO2017049020A1 (en) 2015-09-16 2017-03-23 E Ink Corporation Apparatus and methods for driving displays
US11450286B2 (en) 2015-09-16 2022-09-20 E Ink Corporation Apparatus and methods for driving displays
US10803813B2 (en) 2015-09-16 2020-10-13 E Ink Corporation Apparatus and methods for driving displays
US11098206B2 (en) 2015-10-06 2021-08-24 E Ink Corporation Electrophoretic media including charge control agents comprising quartenary amines and unsaturated polymeric tails
WO2017062345A1 (en) 2015-10-06 2017-04-13 E Ink Corporation Improved low-temperature electrophoretic media
US10062337B2 (en) 2015-10-12 2018-08-28 E Ink California, Llc Electrophoretic display device
US9752034B2 (en) 2015-11-11 2017-09-05 E Ink Corporation Functionalized quinacridone pigments
US10662334B2 (en) 2015-11-11 2020-05-26 E Ink Corporation Method of making functionalized quinacridone pigments
US10196523B2 (en) 2015-11-11 2019-02-05 E Ink Corporation Functionalized quinacridone pigments
US11084935B2 (en) 2015-11-11 2021-08-10 E Ink Corporation Method of making functionalized quinacridone pigments
US10795233B2 (en) 2015-11-18 2020-10-06 E Ink Corporation Electro-optic displays
WO2017139323A1 (en) 2016-02-08 2017-08-17 E Ink Corporation Methods and apparatus for operating an electro-optic display in white mode
US10593272B2 (en) 2016-03-09 2020-03-17 E Ink Corporation Drivers providing DC-balanced refresh sequences for color electrophoretic displays
US10276109B2 (en) 2016-03-09 2019-04-30 E Ink Corporation Method for driving electro-optic displays
US11030965B2 (en) 2016-03-09 2021-06-08 E Ink Corporation Drivers providing DC-balanced refresh sequences for color electrophoretic displays
US10270939B2 (en) 2016-05-24 2019-04-23 E Ink Corporation Method for rendering color images
US10771652B2 (en) 2016-05-24 2020-09-08 E Ink Corporation Method for rendering color images
US11265443B2 (en) 2016-05-24 2022-03-01 E Ink Corporation System for rendering color images
US10554854B2 (en) 2016-05-24 2020-02-04 E Ink Corporation Method for rendering color images
US10527899B2 (en) 2016-05-31 2020-01-07 E Ink Corporation Backplanes for electro-optic displays
WO2018160912A1 (en) 2017-03-03 2018-09-07 E Ink Corporation Electro-optic displays and driving methods
US10852568B2 (en) 2017-03-03 2020-12-01 E Ink Corporation Electro-optic displays and driving methods
US10467984B2 (en) 2017-03-06 2019-11-05 E Ink Corporation Method for rendering color images
US11094288B2 (en) 2017-03-06 2021-08-17 E Ink Corporation Method and apparatus for rendering color images
WO2018164942A1 (en) 2017-03-06 2018-09-13 E Ink Corporation Method for rendering color images
US10444592B2 (en) 2017-03-09 2019-10-15 E Ink Corporation Methods and systems for transforming RGB image data to a reduced color set for electro-optic displays
US10832622B2 (en) 2017-04-04 2020-11-10 E Ink Corporation Methods for driving electro-optic displays
US11398196B2 (en) 2017-04-04 2022-07-26 E Ink Corporation Methods for driving electro-optic displays
US11107425B2 (en) 2017-05-30 2021-08-31 E Ink Corporation Electro-optic displays with resistors for discharging remnant charges
US10825405B2 (en) 2017-05-30 2020-11-03 E Ink Corporatior Electro-optic displays
US10573257B2 (en) 2017-05-30 2020-02-25 E Ink Corporation Electro-optic displays
US11423852B2 (en) 2017-09-12 2022-08-23 E Ink Corporation Methods for driving electro-optic displays
US11721295B2 (en) 2017-09-12 2023-08-08 E Ink Corporation Electro-optic displays, and methods for driving same
US11568827B2 (en) 2017-09-12 2023-01-31 E Ink Corporation Methods for driving electro-optic displays to minimize edge ghosting
US10882042B2 (en) 2017-10-18 2021-01-05 E Ink Corporation Digital microfluidic devices including dual substrates with thin-film transistors and capacitive sensing
CN107657931A (en) * 2017-11-13 2018-02-02 深圳市华星光电技术有限公司 Improve the method and LCD display of LCD display colour cast
US11422427B2 (en) 2017-12-19 2022-08-23 E Ink Corporation Applications of electro-optic displays
WO2019126623A1 (en) 2017-12-22 2019-06-27 E Ink Corporation Electro-optic displays, and methods for driving same
WO2019144097A1 (en) 2018-01-22 2019-07-25 E Ink Corporation Electro-optic displays, and methods for driving same
US11789330B2 (en) 2018-07-17 2023-10-17 E Ink California, Llc Electro-optic displays and driving methods
WO2020018508A1 (en) 2018-07-17 2020-01-23 E Ink California, Llc Electro-optic displays and driving methods
US11719953B2 (en) 2018-08-10 2023-08-08 E Ink California, Llc Switchable light-collimating layer with reflector
US11397366B2 (en) 2018-08-10 2022-07-26 E Ink California, Llc Switchable light-collimating layer including bistable electrophoretic fluid
US11435606B2 (en) 2018-08-10 2022-09-06 E Ink California, Llc Driving waveforms for switchable light-collimating layer including bistable electrophoretic fluid
US11656526B2 (en) 2018-08-10 2023-05-23 E Ink California, Llc Switchable light-collimating layer including bistable electrophoretic fluid
WO2020033175A1 (en) 2018-08-10 2020-02-13 E Ink California, Llc Switchable light-collimating layer including bistable electrophoretic fluid
WO2020033787A1 (en) 2018-08-10 2020-02-13 E Ink California, Llc Driving waveforms for switchable light-collimating layer including bistable electrophoretic fluid
US11314098B2 (en) 2018-08-10 2022-04-26 E Ink California, Llc Switchable light-collimating layer with reflector
WO2020060960A1 (en) 2018-09-17 2020-03-26 E Ink Corporation Backplanes with hexagonal and triangular electrodes
US11353759B2 (en) 2018-09-17 2022-06-07 Nuclera Nucleics Ltd. Backplanes with hexagonal and triangular electrodes
US11511096B2 (en) 2018-10-15 2022-11-29 E Ink Corporation Digital microfluidic delivery device
CN109448615A (en) * 2018-11-28 2019-03-08 江西兴泰科技有限公司 A kind of automatic adjustment method of Electronic Paper drive waveforms
US11380274B2 (en) 2018-11-30 2022-07-05 E Ink California, Llc Electro-optic displays and driving methods
US11735127B2 (en) 2018-11-30 2023-08-22 E Ink California, Llc Electro-optic displays and driving methods
US11062663B2 (en) 2018-11-30 2021-07-13 E Ink California, Llc Electro-optic displays and driving methods
US11460722B2 (en) 2019-05-10 2022-10-04 E Ink Corporation Colored electrophoretic displays
US11257445B2 (en) 2019-11-18 2022-02-22 E Ink Corporation Methods for driving electro-optic displays
US11568786B2 (en) 2020-05-31 2023-01-31 E Ink Corporation Electro-optic displays, and methods for driving same
US11520202B2 (en) 2020-06-11 2022-12-06 E Ink Corporation Electro-optic displays, and methods for driving same
US11450262B2 (en) 2020-10-01 2022-09-20 E Ink Corporation Electro-optic displays, and methods for driving same
WO2023043714A1 (en) 2021-09-14 2023-03-23 E Ink Corporation Coordinated top electrode - drive electrode voltages for switching optical state of electrophoretic displays using positive and negative voltages of different magnitudes
US11869451B2 (en) 2021-11-05 2024-01-09 E Ink Corporation Multi-primary display mask-based dithering with low blooming sensitivity
WO2023122142A1 (en) 2021-12-22 2023-06-29 E Ink Corporation Methods for driving electro-optic displays
WO2023129533A1 (en) 2021-12-27 2023-07-06 E Ink Corporation Methods for measuring electrical properties of electro-optic displays
WO2023129692A1 (en) 2021-12-30 2023-07-06 E Ink California, Llc Methods for driving electro-optic displays
WO2023132958A1 (en) 2022-01-04 2023-07-13 E Ink Corporation Electrophoretic media comprising electrophoretic particles and a combination of charge control agents
WO2023211867A1 (en) 2022-04-27 2023-11-02 E Ink Corporation Color displays configured to convert rgb image data for display on advanced color electronic paper
WO2024044119A1 (en) 2022-08-25 2024-02-29 E Ink Corporation Transitional driving modes for impulse balancing when switching between global color mode and direct update mode for electrophoretic displays
US11922893B2 (en) 2022-12-12 2024-03-05 E Ink Corporation High voltage driving using top plane switching with zero voltage frames between driving frames

Also Published As

Publication number Publication date
US7193625B2 (en) 2007-03-20
US20150339983A1 (en) 2015-11-26
US10319314B2 (en) 2019-06-11
US20050270261A1 (en) 2005-12-08

Similar Documents

Publication Publication Date Title
US7193625B2 (en) Methods for driving electro-optic displays, and apparatus for use therein
JP4651383B2 (en) Method for driving electro-optic display device
US20190272791A1 (en) Methods for driving video electro-optic displays
US7453445B2 (en) Methods for driving electro-optic displays
US20090195568A1 (en) Methods for driving electro-optic displays
JP5739319B2 (en) Method for driving electro-optic display device
KR20060097125A (en) Bi-stable display with dc-balanced over-reset driving
US20060284794A1 (en) Electrophoretic display activation with symmetric data frames
TWI798908B (en) Methods for reducing image artifacts during partial updates of electrophoretic displays
US11450262B2 (en) Electro-optic displays, and methods for driving same
US11830448B2 (en) Methods for driving electro-optic displays
US11257445B2 (en) Methods for driving electro-optic displays

Legal Events

Date Code Title Description
STCB Information on status: application discontinuation

Free format text: ABANDONED -- AFTER EXAMINER'S ANSWER OR BOARD OF APPEALS DECISION