WO1998059382A1 - Voltage controlled color organic light emitting device and method of producing the same - Google Patents

Voltage controlled color organic light emitting device and method of producing the same Download PDF

Info

Publication number
WO1998059382A1
WO1998059382A1 PCT/US1998/012988 US9812988W WO9859382A1 WO 1998059382 A1 WO1998059382 A1 WO 1998059382A1 US 9812988 W US9812988 W US 9812988W WO 9859382 A1 WO9859382 A1 WO 9859382A1
Authority
WO
WIPO (PCT)
Prior art keywords
light emitting
color
pixel
emitting pixel
transport layer
Prior art date
Application number
PCT/US1998/012988
Other languages
French (fr)
Inventor
Gary W. Jones
Original Assignee
Fed Corporation
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
Application filed by Fed Corporation filed Critical Fed Corporation
Publication of WO1998059382A1 publication Critical patent/WO1998059382A1/en

Links

Classifications

    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K59/00—Integrated devices, or assemblies of multiple devices, comprising at least one organic light-emitting element covered by group H10K50/00
    • H10K59/30—Devices specially adapted for multicolour light emission
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K50/00—Organic light-emitting devices
    • H10K50/10—OLEDs or polymer light-emitting diodes [PLED]
    • H10K50/11—OLEDs or polymer light-emitting diodes [PLED] characterised by the electroluminescent [EL] layers
    • H10K50/125—OLEDs or polymer light-emitting diodes [PLED] characterised by the electroluminescent [EL] layers specially adapted for multicolour light emission, e.g. for emitting white light
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K59/00—Integrated devices, or assemblies of multiple devices, comprising at least one organic light-emitting element covered by group H10K50/00
    • H10K59/30—Devices specially adapted for multicolour light emission
    • H10K59/38—Devices specially adapted for multicolour light emission comprising colour filters or colour changing media [CCM]
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2320/00—Control of display operating conditions
    • G09G2320/06—Adjustment of display parameters
    • G09G2320/0666—Adjustment of display parameters for control of colour parameters, e.g. colour temperature
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20—Control 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
    • G09G3/2003—Display of colours
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20—Control 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
    • G09G3/2007—Display of intermediate tones
    • G09G3/2014—Display of intermediate tones by modulation of the duration of a single pulse during which the logic level remains constant
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20—Control 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
    • G09G3/22—Control 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 using controlled light sources
    • G09G3/30—Control 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 using controlled light sources using electroluminescent panels
    • G09G3/32—Control 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 using controlled light sources using electroluminescent panels semiconductive, e.g. using light-emitting diodes [LED]
    • G09G3/3208—Control 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 using controlled light sources using electroluminescent panels semiconductive, e.g. using light-emitting diodes [LED] organic, e.g. using organic light-emitting diodes [OLED]
    • G09G3/3216—Control 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 using controlled light sources using electroluminescent panels semiconductive, e.g. using light-emitting diodes [LED] organic, e.g. using organic light-emitting diodes [OLED] using a passive matrix
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20—Control 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
    • G09G3/22—Control 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 using controlled light sources
    • G09G3/30—Control 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 using controlled light sources using electroluminescent panels
    • G09G3/32—Control 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 using controlled light sources using electroluminescent panels semiconductive, e.g. using light-emitting diodes [LED]
    • G09G3/3208—Control 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 using controlled light sources using electroluminescent panels semiconductive, e.g. using light-emitting diodes [LED] organic, e.g. using organic light-emitting diodes [OLED]
    • G09G3/3225—Control 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 using controlled light sources using electroluminescent panels semiconductive, e.g. using light-emitting diodes [LED] organic, e.g. using organic light-emitting diodes [OLED] using an active matrix
    • G09G3/3258—Control 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 using controlled light sources using electroluminescent panels semiconductive, e.g. using light-emitting diodes [LED] organic, e.g. using organic light-emitting diodes [OLED] using an active matrix with pixel circuitry controlling the voltage across the light-emitting element
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K2102/00—Constructional details relating to the organic devices covered by this subclass
    • H10K2102/301—Details of OLEDs
    • H10K2102/351—Thickness

Landscapes

  • Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Electroluminescent Light Sources (AREA)

Abstract

The present invention is directed to creating a color display device from at least one monochrome organic light emitting device (1). The color display includes at least one organic light emitting device (2) having at least one light emitting pixel. The color display also includes a control assembly (3) for controlling the color of light emitted from each of the at least one light emitting pixel. The control assembly (3) controls the color of each of the at least one pixel by adjusting the voltage of each of the at least one light emitting pixel to produce a specific display color for a particular pixel. The control assembly also controls the brightness of each of the at least one light emitting pixel. The present invention is also directed to a method of producing a color display by setting the voltage of each of the at least one light emitting pixel to a particular color. This is accomplished by selecting and adjusting the voltage for each of the at least one light emitting pixel to produce a specific display color for a particular pixel.

Description

VOLTAGE CONTROLLED COLOR ORGANIC LIGHT EMITTING DEVICE AND METHOD OF PRODUCING THE SAME
Field of the Invention
The present invention relates to an organic light emitting device (OLED). More specifically, the present invention relates to a color display produced from a monochrome organic light emitting device through voltage changes.
Background of the Invention
Organic light emitting devices ("OLEDs") have been known for approximately two decades. All OLEDs work on the same general principles. One or more layers of semiconducting organic material is sandwiched between two electrodes. An electric current is applied to the device, causing negatively charged electrons to move into the organic material(s) from the cathode. Positive charge, typically referred to as holes, moves in the anode. The positive and negative charges meet in the center layers (i.e., the semiconducting organic material), combine, and produce photons. The wave-length ~ and consequently the color ~ of the photons depends on the electronic properties of the organic material in which the photons are generated.
Light emitting devices, which may be generally classified as organic or inorganic, are well known in the graphic display and imaging art. Among the benefits of organic light emitting devices are high visibility due to self-emission, as well as superior impact resistance, and ease of handling of the solid state devices. Organic light emitting devices may have practical application for television and graphic displays, as well as in digital printing applications.
An organic light emitting device is typically a laminate formed on a substrate such as soda-lime glass. A light-emitting layer of a luminescent organic solid, as well as adjacent semiconductor layers, are sandwiched between a cathode and an anode. The semiconductor layers may be hole-injecting and electron-injecting layers. The light-emitting layer may be any of a multitude of fluorescent organic solids. When a potential difference is applied across the cathode and anode, electrons from the electron- injecting layer, and holes from the hole-injecting layer are injected into the light- emitting layer. They recombine, emitting light.
In a typical matrix-addressed OLED, numerous light emitting devices are formed on a single substrate and arranged in groups in a regular grid pattern. Several light emitting device groups forming a column of the grid may share a common cathode, or cathode line. Several light emitting device groups forming a row of the grid may share a common anode, or anode line. The individual light emitting devices in a given group emit light when their cathode line and anode line are activated at the same time. Activation may be by rows and columns or in an active matrix with individual cathode and anode pads.
Organic light emitting devices have a number of beneficial characteristics. These include a low activation voltage (about 4.5 volts), fast response when formed with a thin light-emitting layer, and high brightness in proportion to the injected electric current. By changing the kinds of flourescent organic solids making up the light-emitting layer, many different colors of light may be emitted, ranging from visible blue, to green, yellow, and red. Organic light emitting devices are currently the subject of aggressive investigative efforts.
The color of light emitted from the OLED device can be controlled by the selection of the organic material. White light is produced by generating blue, red and green lights simultaneously. Specifically, the precisely color of light emitted by a particular structure can be controlled both by selection of the organic material, as well as by selection of dopants. The formation of conventional color displays is typically more complex and expensive than the formation of monochrome displays.
Objects of the Invention
It is therefore an object of the present invention produce a color display or chromatically modulatable light source from a monochrome organic light emitting device.
It is another object of the present invention to adjust the color of light emitting from individual pixels of an organic light emitting device by controlling the voltage applied to each individual pixel. It is another object of the present invention to adjust the brightness of the light emitted from each pixel by controlling the voltage applied to each pixel.
It is a further object of the present invention to provide at least one filter to control the wavelengths of light emitted from each pixel to produce saturated colors.
It is another object of the present invention to provide a low cost color display or chromomatically modulatable light source.
It is another object of the present invention to provide pulse width modulation of the wavelength of light emitted from the display to permit various gray levels for each color displayed on the color display.
Summary of the Invention
The present invention is directed to a color display. The color display includes at least one organic light emitting device. Each of the at least one organic light emitting device has at least one light emitting pixel. A pixel refers to an element of a multiple addressable light source array, or a single nonaddressable light source element. The color display also includes control means for controlling the color of light emitted from each of the at least one light emitting pixel. The control means controls the color of each of the at least one pixel by adjusting the voltage of each of the at least one light emitting pixel to produce a specific display color for a particular pixel.
The control means may further control the brightness of each of the at least one light emitting pixel. The control means controls the color of each of the at least one pixel by adjusting the voltage of each of the at least one light emitting pixel to produce a specific display color for a particular pixel.
Each at least one organic light emitting device includes a first conductor layer, a second conductor layer spaced from the first conductor layer, and an emitter layer positioned between the first and second conductor layers.
The emitter layer may include an electron transport layer, and a hole transport layer. The hole transport layer is positioned adjacent the first conductor layer. The electron transport layer is positioned adjacent the second conductor layer. Light is generated at the location where a hole is extinguished. Typically, this occurs at the interface between the electron transport layer and the hole transport layer.
The hole transport layer and the electron transport layer each have a predetermined thickness. To increase brightness, the predetermined thickness of the electron transport layer is less than the predetermined thickness of the hole transport layer such that the interface is closer to the second conductor layer.
The color display may further comprise at least one filter to control the light emitted from each of the at least one light emitting pixel.
The present invention is directed to a method of producing a color display. The color display includes at least one organic light emitting device. The method includes the step of providing at least one organic light emitting device. Each of the at least one organic light emitting device has at least one light emitting pixel. The method further includes the step of setting each of the at least one light emitting pixel to a particular color.
The at least one organic light emitting device includes a light emitter layer. The step of setting each of the at least one light emitting pixel to a particular color includes forming a light emitter layer having a reduced thickness. The reduced thickness permits the changing of the wavelength of the light emitted from a particular color producing a particular color.
The method may further include the step of providing at least one filter to control the light emitted from each of the at least one light emitting pixel. In a preferred embodiment, the at least one filter is a triband filter.
The method may further comprise the step of setting each of the at least one light emitting pixel to a selected brightness.
The step of setting each of the at least one light emitting pixel to a particular color preferably include selecting a voltage for each of the at least one light emitting pixel to produce a specific display color for a particular pixel. The specific display color for a particular pixel may be adjusted by changing the voltage of the particular pixel. The light emitted from a particular pixel has a specific wavelength. The step of changing the voltage of a particular pixel may change the specific wavelength. The present invention is also directed to a method of adjusting the color output of a color display device. The color display device includes at least one organic light emitting device. The method includes the step of providing at least one organic light emitting device. Each of the at least one organic light emitting device has at least one light emitting pixel. The method further includes the step of adjusting the color of each of the at least one light emitting pixel to a particular color.
The method also includes the step of providing at least one filter to control the light emitted from each of the at least one light emitting pixel. The method may also include the step of setting each of the at least one light emitting pixel to a selected brightness.
The step of adjusting the color of each of the at least one light emitting pixel includes adjusting the voltage for each of the at least one light emitting pixel to produce a specific display color for a particular pixel.
The specific display color for a particular pixel may be adjusted by changing the voltage of the particular pixel. The light emitted from a particular pixel has a specific wavelength, and the step of changing the voltage of a particular pixel changes the specific wavelength.
Brief Description of the Drawings
The invention will now be described in conjunction with the following drawings in which like reference numerals designate like elements and wherein:
Fig. 1 is a side view illustrating the layers of an organic light emitting device according to an embodiment of the present invention; and
Fig. 2 is a side view illustrating the layers of an organic light emitting device according to an embodiment of the present invention.
Detailed Description of the Preferred Embodiments
The present invention is directed to an improved light emitting device that includes an organic light emitting device (OLED) that permits the use of a monochrome device to produce a color display. The OLED 1 preferably includes an array of light emitting pixels. A pixel refers to an element of a multiple addressable light source array, or a single nonaddressable light source element. The OLED 1 may comprise a plurality of rows of individual pixels. Alternatively, the individual pixels may be arranged in a line array. In a preferred embodiment, the array of pixels is an active array. However, it is contemplated that passive arrays (e.g., larger shaped pixels) are considered to be within the scope of the present invention.
A preferred embodiment of the present invention will now be described in connection with Fig. 1. The OLED 1 is formed on a substrate 2. The substrate 2 is preferably an electrically insulator ultra thin substrate. The substrate 2 may be formed from a borosilicate glass, silicon on quartz or other suitable substrate material.
The OLED 1 includes a first conductor layer 11 formed on the substrate 2. The first conductor layer 11 preferably consists of a plurality of light transmissive electrode elements. The electrode elements of the first conductor layer 11 are preferably formed as lines directly on the substrate 2 using conventional techniques. The first conductor layer 11 may be screen coated or lithographically patterned using conventional photoresist and etching techniques.
The first conductor layer 11 is preferably formed from a mixture of indium oxide and tin oxide or indium tin oxide (ITO). However, it is contemplated that other suitable light transmissive electrically conductive materials may be used to construct the electrode elements (e.g.. tin oxide and indium oxide).
A light emitter layer 12 is formed on the first conductor layer 11. The light emitter layer 12 may comprise one or more layers. The light emitter layer 12 is preferably form one or more organic material(s). In a preferred embodiment, the light emitter layer 12 includes a hole transport layer 121, a light emitting layer 122, and an electron transport layer 123. The hole transport layer 121 is located on top of the first conductor layer 11. The light emitting layer 122 is sandwiched between the hole transport layer 121 and the electron transport layer 123. In a preferred embodiment, the electron transport layer 123 is formed from a light emitting material such as Alq. However, other appropriate materials are also contemplated to be within the scope of the present invention. A second conductor layer 13 is located on top of the electron transport layer 123. When an electric current is applied to the device, negatively charged electrons are generated and move into the light emitter layer 12 from the cathode or second conductor layer 13. Positive charges or holes are generated and move into the light emitter layer 12 from the anode or first conductor layer 11. The electrons and holes meet in the light emitter layer 12. The electrons and holes combine in the light emitter layer 12 and produce photons.
In accordance with a preferred embodiment of the present invention, a color display may be produced using either a top down or bottom up monochrome display, as described above. A color display may be produced by shifting the wavelength of the emitted light. This can be accomplished by changing the voltage of the OLED display. The process for shifting the wavelength of light will now be described.
During formation of the OLED, a reduced thickness of the electron transport layer 121 is provided. The electron transport layer 123 preferably has a thickness of under 40 nm. The reduced thickness of the electron transport layer 123 impacts (i.e., shifts) the region where recombination of the electrons and holes occurs. This changes the average exiton energy when recombination occurs, which shifts the wavelength. The shift in wavelength results in the emission of a different color light.
The shift in wavelength may be further enhanced through the use of dyes, such as, for example, blue dye (e.g., BAlq-mpp and DPVBi), red dye and green dye (e.g., coumerin 6) and the use of dopants, such as, for example, DCM, DCJ, DMQA, C6 and perylene in the light emitter layer 12, and specifically in the hole transport layer 121 and the electron transport layer 123. Additionally, the use of material, such as, poly(2,5-dialkoxy-p- phenylene vinylene) (PDAOPV) to form the hole transport layer 121 may be used to further shift the range where exitons are extinguished such that the wavelength of light is shifted. It is necessary to optimize the dopants for the electron transport layer 123 to allow for more voltage saturation to permit the control of the color of the display.
The reduced thickness of the electron transport layer 123 permits voltage changes that will shift the nominal wavelength of light emitted from each pixel. As such, the color of individual pixels may be controlled by adjusting the voltage. The voltage may be adjusted using a suitable driver 3. For example, by increasing the voltage, the wavelength of the emitted light shortens, which produces a blue color. Decreasing the voltage increases the wavelength of the emitted light producing a light that is more red in color. Typically, a voltage in the range of 8 V will produce red light. Green light will be produced with voltages in the range of 1 IV. Blue light will be produced with voltages in the range of 14V.
The control of voltage for individual pixels permits the fabrication of a color display from a simple monochrome display. Each pixel can be set to a particular color as well as a selected brightness.
When various gray levels are desired for each color, pulse width modulation of gray level is necessary. A driver described in U.S. Patent Application Serial No.
(FED97-116), filed , entitled "OLED Active Matrix Using a Single Transistor
Current Mode Pixel Design" may be used to accomplish pulse width modulation. The disclosure of which is incorporated herein by reference. For a non-gray level color display, the controlled individual pixel voltages could be used to change color.
A color display may be obtained by running the display in a color sequential type mode. In this mode, a common electrode, such as the first conductor layer 11, and red data are activated. The green data is activated. Finally, the blue data is activated a row at a time. Similarly, full frames of each data for each color may be presented sequentially. The full frame approach permits the display to be run at a maximum brightness when an active matrix transistor array is used. This permits DC-like operation of the display where illuminated pixels stay on until the data is changed and a momentary inverse voltage pulse is applied. The frames would novelly be operating with the common electrode changing the predetermined voltages corresponding to color values every third frame. As described above, a voltage of 8 V would used to produce the color red, 11 V to produce the color green, and 14V to produce the color blue. This approach may be used for multicolor systems such as red-green combinations (used, for example, in gun sites) and for full color displays where saturation is not required.
Additionally, a filter 14 may be provided on the second conductor layer 13. The filter 14 would be only light having wavelength near a target value to be passed through the filter 14 and emitted from the OLED. The filter 14 is preferably a triband filter. The use of a filter 14 may be used to obtain more saturated colors from such a display.
The inventor of the present invention realizes that the some efficiency (i.e., shorter life expectancy) is lost due to the reduced thickness of the electron transport layer 123. However, the benefits of being able to produce a color display from a monochrome device is considered to be greater than the anticipated efficiency loss. Furthermore, this novel approach to the formation of color displays will result in a significant cost savings when compared to conventional techniques for forming color displays. Additionally, the above- described system produces crisper more vivid colors.
The above described technique can be combined with other direct colors, such as, a blue-green modulatable pixel and red color to achieve full color.
While this invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, the preferred embodiments of the invention as set forth herein are intended to be illustrative, not limiting. Various changes may be made without departing from the spirit and scope of the invention as defined in the following claims.

Claims

What Is Claimed Is:
1. A method of producing a color display, the color display including at least one organic light emitting device, said method comprising the steps of: providing at least one organic light emitting device, wherein each of the at least one organic light emitting device having at least one light emitting pixel; and setting each of the at least one light emitting pixel to a particular color.
2. The method according to claim 1, wherein the at least one organic light emitting device includes a light emitter layer, said step for setting each of the at least one light emitting pixel to a particular color includes forming a light emitter layer having a reduced thickness.
3. The method according to claim 2, wherein the reduced thickness permits the changing of the wavelength of the light emitted from a particular color producing a particular color.
4. The method according to claim 1 , further comprising the step of providing at least one filter to control the light emitted from each of the at least one light emitting pixel.
5. The method according to claim 4, wherein the at least one filter is a triband filter.
6. The method according to claim 1, further comprising the step of setting each of the at least one light emitting pixel to a selected brightness.
7. The method according to claim 6, further comprising the step of providing at least one filter to control the light emitted from each of the at least one light emitting pixel.
8. The method according to claim 1, wherein the step of setting each of the at least one light emitting pixel to a particular color comprises the step of selecting a voltage for each of the at least one light emitting pixel to produce a specific display color for a particular pixel.
9. The method according to claim 8, further comprising the step of setting each of the at least one light emitting pixel to a selected brightness.
10. The method according to claim 8, wherein the at least one organic light emitting device includes a light emitter layer, said step for setting each of the at least one light emitting pixel to a particular color includes forming a light emitter layer having a reduced thickness.
11. The method according to claim 10, wherein the reduced thickness permits the changing of the wavelength of the light emitted from a particular color producing a particular color.
12. The method according to claim 8, further comprising the step of providing at least one filter to control the light emitted from each of the at least one light emitting pixel.
13. The method according to claim 8, wherein the specific display color for a particular pixel may be adjusted by changing the voltage of the particular pixel.
14. The method according to claim 13, wherein the light emitted from a particular pixel has a specific wavelength, and the step of changing the voltage of a particular pixel changes the specific wavelength.
15. The method according to claim 14, further comprising the step of setting each of the at least one light emitting pixel to a selected brightness.
16. The method according to claim 15, further comprising the step of providing at least one filter to control the light emitted from each of the at least one light emitting pixel.
17. The method according to claim 16, wherein the at least one organic light emitting device includes a light emitter layer, said step for setting each of the at least one light emitting pixel to a particular color includes forming a light emitter layer having a reduced thickness.
18. The method according to claim 17, wherein the reduced thickness permits the changing of the wavelength of the light emitted from a particular color producing a particular color.
19. A method of adjusting the color output of a color display device, the color display device including at least one organic light emitting device, said method comprising the steps of: providing at least one organic light emitting device, wherein each of the at least one organic light emitting device having at least one light emitting pixel; and adjusting the color of each of the at least one light emitting pixel to a particular color.
20. The method according to claim 19, further comprising the step of providing at least one filter to control the light emitted from each of the at least one light emitting pixel.
21. The method according to claim 19, further comprising the step of setting each of the at least one light emitting pixel to a selected brightness.
22. The method according to claim 21, further comprising the step of providing at least one filter to control the light emitted from each of the at least one light emitting pixel.
23. The method according to claim 19, wherein the step of adjusting the color of each of the at least one light emitting pixel includes adjusting the voltage for each of the at least one light emitting pixel to produce a specific display color for a particular pixel.
24. The method according to claim 23, further comprising the step of setting each of the at least one light emitting pixel to a selected brightness.
25. The method according to claim 24, further comprising the step of providing at least one filter to control the light emitted from each of the at least one light emitting pixel.
26. The method according to claim 19, wherein the specific display color for a particular pixel may be adjusted by changing the voltage of the particular pixel.
27. The method according to claim 26, wherein the light emitted from a particular pixel has a specific wavelength, and the step of changing the voltage of a particular pixel changes the specific wavelength.
28. The method according to claim 27, further comprising the step of setting each of the at least one light emitting pixel to a selected brightness.
29. The method according to claim 28, further comprising the step of providing at least one filter to control the light emitted from each of the at least one light emitting pixel.
30. A color display comprising: at least one organic light emitting device, wherein each of the at least one organic light emitting device having at least one light emitting pixel; control means for controlling the color of light emitted from each of said at least one light emitting pixel.
31. The color display according to claim 30, wherein said control means controls the color of each of said at least one pixel by adjusting the voltage of each of said at least one light emitting pixel to produce a specific display color for a particular pixel.
32. The color display according to claim 30, wherein said control means further controls the brightness of each of said at least one light emitting pixel.
33. The color display according to claim 32, wherein said control means controls the color of each of said at least one pixel by adjusting the voltage of each of said at least one light emitting pixel to produce a specific display color for a particular pixel.
34. The color display according to claim 30, wherein each at least one organic light emitting device comprises: a first conductor layer; a second conductor layer spaced from said first conductor layer; and an emitter layer positioned between said first and second conductor layers.
35. The color display according to claim 34, wherein said emitter layer comprises: an electron transport layer; and a hole transport layer, wherein said hole transport layer is positioned adjacent said first conductor layer, said electron transport layer being positioned adjacent said second conductor layer, and light is generated at an interface between said electron transport layer and said hole transport layer.
36. The color display according to claim 35, wherein said hole transport layer and said electron transport layer each have a predetermined thickness, said predetermined thickness of said electron transport layer being less than said predetermined thickness of said hole transport layer such that said interface is closer to said second conductor layer.
37. The color display according to claim 36, wherein said electron transport layer has an approximate thickness of 40 nm.
38. The color display according to claim 36, wherein said electron transport layer has an approximate thickness of under 40 nm.
39. The color display according to claim 36, wherein said electron transport layer is formed from Alq.
40. The color display according to claim 36, further comprising at least one filter to control the light emitted from each of the at least one light emitting pixel.
41. The color display according to claim 40, wherein said control means controls the color of each of said at least one pixel by adjusting the voltage of each of said at least one light emitting pixel to produce a specific display color for a particular pixel.
42. The color display according to claim 41, wherein said control means further controls the brightness of each of said at least one light emitting pixel.
43. The color display according to claim 34, wherein said control means controls the color of each of said at least one pixel by adjusting the voltage of each of said at least one light emitting pixel to produce a specific display color for a particular pixel.
44. The color display according to claim 43, further comprising at least one filter to control the light emitted from each of the at least one light emitting pixel.
PCT/US1998/012988 1997-06-23 1998-06-23 Voltage controlled color organic light emitting device and method of producing the same WO1998059382A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US5047397P 1997-06-23 1997-06-23
US60/050,473 1997-06-23

Publications (1)

Publication Number Publication Date
WO1998059382A1 true WO1998059382A1 (en) 1998-12-30

Family

ID=21965445

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US1998/012988 WO1998059382A1 (en) 1997-06-23 1998-06-23 Voltage controlled color organic light emitting device and method of producing the same

Country Status (1)

Country Link
WO (1) WO1998059382A1 (en)

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6801000B2 (en) 2000-06-23 2004-10-05 Cambridge Display Technology Ltd. Light-emitting devices
WO2005038763A1 (en) * 2003-10-16 2005-04-28 Koninklijke Philips Electronics N.V. Color display panel
JP2006351538A (en) * 2005-06-14 2006-12-28 Novaled Ag Organic luminous component and its operation method
WO2008040318A1 (en) * 2006-09-29 2008-04-10 Osram Opto Semiconductors Gmbh Organic light-emitting component, device comprising such a component, illumination device and display device
FR2931296A1 (en) * 2008-05-13 2009-11-20 Commissariat Energie Atomique CONTROL CIRCUIT OF A PIXEL WITH VARIABLE CHROMATIC COORDINATES
US8693084B2 (en) 2008-03-07 2014-04-08 Qualcomm Mems Technologies, Inc. Interferometric modulator in transmission mode
US8817357B2 (en) 2010-04-09 2014-08-26 Qualcomm Mems Technologies, Inc. Mechanical layer and methods of forming the same
US8928967B2 (en) 1998-04-08 2015-01-06 Qualcomm Mems Technologies, Inc. Method and device for modulating light
US8963159B2 (en) 2011-04-04 2015-02-24 Qualcomm Mems Technologies, Inc. Pixel via and methods of forming the same
US8971675B2 (en) 2006-01-13 2015-03-03 Qualcomm Mems Technologies, Inc. Interconnect structure for MEMS device
US9086564B2 (en) 2004-09-27 2015-07-21 Qualcomm Mems Technologies, Inc. Conductive bus structure for interferometric modulator array
US9097885B2 (en) 2004-09-27 2015-08-04 Qualcomm Mems Technologies, Inc. Device having a conductive light absorbing mask and method for fabricating same
US9110289B2 (en) 1998-04-08 2015-08-18 Qualcomm Mems Technologies, Inc. Device for modulating light with multiple electrodes
US9134527B2 (en) 2011-04-04 2015-09-15 Qualcomm Mems Technologies, Inc. Pixel via and methods of forming the same

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4707141A (en) * 1986-01-08 1987-11-17 Karel Havel Variable color analog timepiece
US5325107A (en) * 1988-11-30 1994-06-28 Sharp Kabushiki Kaisha Method and apparatus for driving a display device
US5552678A (en) * 1994-09-23 1996-09-03 Eastman Kodak Company AC drive scheme for organic led
US5666129A (en) * 1994-07-06 1997-09-09 Level One Communications, Inc. Electrical display elements for displaying multiple different conditions
US5695269A (en) * 1996-01-29 1997-12-09 Delco Electronics Corporation Multi-color display lighting by led
US5736754A (en) * 1995-11-17 1998-04-07 Motorola, Inc. Full color organic light emitting diode array

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4707141A (en) * 1986-01-08 1987-11-17 Karel Havel Variable color analog timepiece
US5325107A (en) * 1988-11-30 1994-06-28 Sharp Kabushiki Kaisha Method and apparatus for driving a display device
US5666129A (en) * 1994-07-06 1997-09-09 Level One Communications, Inc. Electrical display elements for displaying multiple different conditions
US5552678A (en) * 1994-09-23 1996-09-03 Eastman Kodak Company AC drive scheme for organic led
US5736754A (en) * 1995-11-17 1998-04-07 Motorola, Inc. Full color organic light emitting diode array
US5695269A (en) * 1996-01-29 1997-12-09 Delco Electronics Corporation Multi-color display lighting by led

Cited By (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9110289B2 (en) 1998-04-08 2015-08-18 Qualcomm Mems Technologies, Inc. Device for modulating light with multiple electrodes
US8928967B2 (en) 1998-04-08 2015-01-06 Qualcomm Mems Technologies, Inc. Method and device for modulating light
US6801000B2 (en) 2000-06-23 2004-10-05 Cambridge Display Technology Ltd. Light-emitting devices
WO2005038763A1 (en) * 2003-10-16 2005-04-28 Koninklijke Philips Electronics N.V. Color display panel
US9097885B2 (en) 2004-09-27 2015-08-04 Qualcomm Mems Technologies, Inc. Device having a conductive light absorbing mask and method for fabricating same
US9086564B2 (en) 2004-09-27 2015-07-21 Qualcomm Mems Technologies, Inc. Conductive bus structure for interferometric modulator array
JP2006351538A (en) * 2005-06-14 2006-12-28 Novaled Ag Organic luminous component and its operation method
JP4560494B2 (en) * 2005-06-14 2010-10-13 ノバレット、アクチェンゲゼルシャフト Operation method of organic light emitting component and organic light emitting component
US8971675B2 (en) 2006-01-13 2015-03-03 Qualcomm Mems Technologies, Inc. Interconnect structure for MEMS device
WO2008040318A1 (en) * 2006-09-29 2008-04-10 Osram Opto Semiconductors Gmbh Organic light-emitting component, device comprising such a component, illumination device and display device
US8693084B2 (en) 2008-03-07 2014-04-08 Qualcomm Mems Technologies, Inc. Interferometric modulator in transmission mode
FR2931296A1 (en) * 2008-05-13 2009-11-20 Commissariat Energie Atomique CONTROL CIRCUIT OF A PIXEL WITH VARIABLE CHROMATIC COORDINATES
US8749596B2 (en) 2008-05-13 2014-06-10 Commissariat A L'energie Atomique Et Aux Energies Alternatives Display device based on pixels with variable chromatic coordinates
WO2009141530A1 (en) * 2008-05-13 2009-11-26 Commissariat à l'Energie Atomique Improved display device based on pixels with variable chromatic coordinates
US8817357B2 (en) 2010-04-09 2014-08-26 Qualcomm Mems Technologies, Inc. Mechanical layer and methods of forming the same
US8963159B2 (en) 2011-04-04 2015-02-24 Qualcomm Mems Technologies, Inc. Pixel via and methods of forming the same
US9134527B2 (en) 2011-04-04 2015-09-15 Qualcomm Mems Technologies, Inc. Pixel via and methods of forming the same

Similar Documents

Publication Publication Date Title
US7510454B2 (en) OLED device with improved power consumption
CN100459144C (en) OLED device having microcavity gamut subpixels
US7633218B2 (en) OLED device having improved lifetime and resolution
US7760165B2 (en) Control circuit for stacked OLED device
US7190122B2 (en) OLED display with improved active matrix circuitry
US7091936B1 (en) Color display device
CN107425043B (en) Organic light emitting display device, control method and display device
US7781957B2 (en) Electro-luminescent device with improved efficiency
US8786177B2 (en) Single-photon type organic electroluminescent element
JP2000235891A (en) Organic electroluminescent device
JPH11327506A (en) Driving circuit for el display device
WO1998059382A1 (en) Voltage controlled color organic light emitting device and method of producing the same
US11476450B2 (en) Display device
US20090033604A1 (en) Hybrid Display
CN100448020C (en) Electroluminescent display device
US20100252841A1 (en) Oled device having improved lifetime and resolution
US20060226769A1 (en) Display device
US6278417B1 (en) Method of driving a display device, and a display device
US20020190664A1 (en) Organic EL element, organic EL element array and organic EL display
JP4658466B2 (en) Image display device
Burrows et al. Stacked organic light-emitting devices for full-color flat panel displays
WO2020016998A1 (en) Display device, display device manufacturing method, display device manufacturing apparatus
JPH10171375A (en) Display device
KR101729166B1 (en) Display device
JPH04341797A (en) Blue-emitting thin film el element

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): CA CN IL JP KR NO RU SG US

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LU MC NL PT SE

121 Ep: the epo has been informed by wipo that ep was designated in this application
WWE Wipo information: entry into national phase

Ref document number: 09242676

Country of ref document: US

NENP Non-entry into the national phase

Ref country code: CA

NENP Non-entry into the national phase

Ref country code: JP

Ref document number: 1999504957

Format of ref document f/p: F

122 Ep: pct application non-entry in european phase