EP0992972A2 - Method of adjusting the light intensity of a cell of a flat panel display - Google Patents

Method of adjusting the light intensity of a cell of a flat panel display Download PDF

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Publication number
EP0992972A2
EP0992972A2 EP99119311A EP99119311A EP0992972A2 EP 0992972 A2 EP0992972 A2 EP 0992972A2 EP 99119311 A EP99119311 A EP 99119311A EP 99119311 A EP99119311 A EP 99119311A EP 0992972 A2 EP0992972 A2 EP 0992972A2
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EP
European Patent Office
Prior art keywords
brightness
signal
cell
variable
analog
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.)
Withdrawn
Application number
EP99119311A
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German (de)
French (fr)
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EP0992972A3 (en
Inventor
Roland Dipl.-Ing. Bohl
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Loewe Opta GmbH
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Loewe Opta GmbH
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Publication date
Application filed by Loewe Opta GmbH filed Critical Loewe Opta GmbH
Publication of EP0992972A2 publication Critical patent/EP0992972A2/en
Publication of EP0992972A3 publication Critical patent/EP0992972A3/en
Withdrawn legal-status Critical Current

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    • 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
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G5/00—Control arrangements or circuits for visual indicators common to cathode-ray tube indicators and other visual indicators
    • G09G5/10—Intensity circuits
    • 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
    • G09G2320/02—Improving the quality of display appearance
    • G09G2320/0238—Improving the black level
    • 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
    • G09G2320/02—Improving the quality of display appearance
    • G09G2320/0271—Adjustment of the gradation levels within the range of the gradation scale, e.g. by redistribution or clipping
    • G09G2320/0276—Adjustment of the gradation levels within the range of the gradation scale, e.g. by redistribution or clipping for the purpose of adaptation to the characteristics of a display device, i.e. gamma correction
    • 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
    • G09G2320/0606—Manual adjustment
    • 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
    • G09G2320/0626—Adjustment of display parameters for control of overall brightness
    • 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
    • G09G3/28—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 luminous gas-discharge panels, e.g. plasma panels

Definitions

  • the invention relates to a method for adjusting the brightness of a cell a flat display that can be changed by time control, and a circuit arrangement for performing the method.
  • Flat displays the luminance the evaluation measure for the brightness, i.e. that the different sensitivities of the eye to different Light wavelengths must be taken into account. This is why for all devices that are equipped with a flat display, just like for all televisions and monitors with cathode ray tubes, brightness control provided, when pressed, the luminance of each cell is changed. With plasma displays, the ignited state of the Maintain cell longer or shorter. The measure of time is through Digital values, e.g. between 0 and 255. In contrast to picture tubes with such a plasma display, an 8-bit system with the value range provided from 0 to 255. The respective 8-bit word, the embodies the video output signal, so it can be linear in brightness to adjust.
  • Flat displays include plasma displays and TFT displays and other controllable displays with single cells understood.
  • the display is fully controlled, i.e. a comparison was made so that the Black value the number 0 and white value the highest number in the range, e.g. 255, is assigned.
  • the invention has for its object a method and a circuit arrangement specify that prevent an oversteer and a Improve brightness perception.
  • the brightness setting variables are no more than linear quantities are generated instead depending on the subjective perception of brightness set.
  • the absolute black value e.g. the set value Corresponds to 0 of the range of values, and the range of stretched black to light gray and so compressed in the white area that the amplitude remains unchanged.
  • the video input signal is through the non-linear control of the brightness setting variable depending on fixed coefficients modified, the display or viewer specific can be fixed.
  • the modified brightness setting variable is a mirror image subjective perception of brightness. With this modified brightness setting variable Then the switching times of the cells from the control circuit certainly.
  • the block diagram shows a video processor 1, in which the video input signal which is present at input 2 is modified by a brightness signal which is present at an input 3 of a microprocessor 4.
  • This brightness signal is digitized by the microprocessor 4, if it is not yet in digital form, and subjected to a coefficient evaluation, so that when the brightness signal changes linearly via an I 2 C bus 5, the video processor is supplied with a modified brightness signal that corresponds to the subjective perception of brightness .
  • the video output signal obtained by multiplication or addition therefore always corresponds to a size which is below the maximum modulation size of the individual cell.
  • the output 6 is connected to the control circuit, not shown, which drives the cell.

Abstract

The brightness of the cell is variable by a time-based controller. The brightness setting is not varied linearly, but is higher in darker regions than brighter regions, taking account of the subjective brightness sensitivity of the eye, and remains below a defined maximum. A linearly variable brightness setting is converted into nonlinear values by a processor based on function coefficients, and these values are added to a digital or analog video signal. The video output signal is fed to a cell control circuit. A circuit is also claimed.

Description

Die Erfindung betrifft ein Verfahren zur Einstellung der Helligkeit einer Zelle eines Flachdisplays, die durch zeitliche Ansteuerung veränderbar ist, und eine Schaltungsanordnung zur Durchführung des Verfahrens.The invention relates to a method for adjusting the brightness of a cell a flat display that can be changed by time control, and a circuit arrangement for performing the method.

Wie bekannt, ist in Übereinstimmung mit Kathodenstrahlröhren auch bei Flachdisplays die Leuchtdichte das Bewertungsmaß für die Helligkeit, d.h., daß die unterschiedlichen Empfindlichkeiten des Auges für verschiedene Lichtwellenlängen berücksichtigt werden müssen. Aus diesem Grunde sind bei allen Geräten, die mit einem Flachdisplay ausgestattet sind, genauso wie bei allen Fernsehgeräten und Monitoren mit Kathodenstrahlröhren, Helligkeitsregler vorgesehen, bei deren Betätigung die Leuchtdichte jeder Zelle verändert wird. Bei Plasma-Displays wird dabei der gezündete Zustand der Zelle länger oder kürzer aufrechterhalten. Das zeitliche Maß ist dabei durch Digitalwerte, z.B. zwischen 0 und 255, bestimmt. Im Gegensatz zu Bildröhren wird bei einem solchen Plasma-Display ein 8-Bit-System mit dem Wertebereich von 0 bis 255 zur Verfügung gestellt. Das jeweilige 8-Bit-Wort, das das Video-Ausgangssignal verkörpert, läßt sich somit linear in der Helligkeit einstellen. Unter Flachdisplays werden Plasma-Displays und TFT- Displays und andere steuerbare Displays mit Einzelzellen verstanden.As is well known, in accordance with cathode ray tubes Flat displays the luminance the evaluation measure for the brightness, i.e. that the different sensitivities of the eye to different Light wavelengths must be taken into account. This is why for all devices that are equipped with a flat display, just like for all televisions and monitors with cathode ray tubes, brightness control provided, when pressed, the luminance of each cell is changed. With plasma displays, the ignited state of the Maintain cell longer or shorter. The measure of time is through Digital values, e.g. between 0 and 255. In contrast to picture tubes with such a plasma display, an 8-bit system with the value range provided from 0 to 255. The respective 8-bit word, the embodies the video output signal, so it can be linear in brightness to adjust. Flat displays include plasma displays and TFT displays and other controllable displays with single cells understood.

Bei einer Helligkeits-Schwarzwert-Einstellung im herkömmlichen Sinn wird die Amplitude des Signals nicht verändert, jedoch der dem Schwarzwert proportionale DC-Wert verschoben. Dies kommt beim Plasma-Display einer sofortigen nicht akzeptablen Übersteuerung gleich.With a brightness-black level setting in the conventional sense the amplitude of the signal does not change, but that of the black level proportional DC value shifted. This comes with a plasma display immediate unacceptable clipping equal.

Um die ohnehin im Vergleich mit Kathodenstrahl-Bildröhren geringere Leuchtdichte der Displays zu nutzen, wird bereits im Auslieferungszustand das Display voll ausgesteuert, d.h. ein Abgleich vollzogen, so daß dem Schwarzwert die Zahl 0 und dem Weißwert die höchste Zahl des Wertebereiches, z.B. 255, zugeordnet ist. To the smaller in comparison to cathode ray tubes Using the display's luminance is already in the delivery state the display is fully controlled, i.e. a comparison was made so that the Black value the number 0 and white value the highest number in the range, e.g. 255, is assigned.

Der Erfindung liegt die Aufgabe zugrunde, ein Verfahren und eine Schaltungsanordnung anzugeben, die eine Übersteuerung verhindern und eine Verbesserung des Helligkeitsempfindens bewirken.The invention has for its object a method and a circuit arrangement specify that prevent an oversteer and a Improve brightness perception.

Die Aufgabe löst die Erfindung durch das im Anspruch 1 angegebene Verfahren sowie durch eine Schaltungsanordnung zur Durchführung des Verfahren, so wie sie im Anspruch 8 angegeben ist.The object is achieved by the invention as specified in claim 1 Method and by a circuit arrangement for performing the Method as specified in claim 8.

Gemäß der Erfindung werden die Helligkeitseinstellgrößen nicht mehr als lineare Größen generiert sondern abhängig vom subjektiven Helligkeitsempfinden eingestellt. Dabei wird der absolute Schwarzwert, der z.B. dem Einstellwert 0 des Wertebereiches entspricht, festgehalten und der Bereich von schwarz bis hellgrau gedehnt und im weißen Bereich derart gestaucht, daß die Amplitude unverändert bleibt. Das Video-Eingangssignal wird durch die nichtlineare Aussteuerung der Helligkeitseinstellgröße in Abhängigkeit von festgelegten Koeffizienten modifiziert, die display- oder betrachterspezifisch festgelegt sein können. Die modifizierte Helligkeitseinstellgröße ist ein Spiegelbild des subjektiven Helligkeitsempfindens. Mit dieser modifizierten Helligkeitseinstellgröße werden sodann die Schaltzeiten der Zellen von der Steuerschaltung bestimmt.According to the invention, the brightness setting variables are no more than linear quantities are generated instead depending on the subjective perception of brightness set. The absolute black value, e.g. the set value Corresponds to 0 of the range of values, and the range of stretched black to light gray and so compressed in the white area that the amplitude remains unchanged. The video input signal is through the non-linear control of the brightness setting variable depending on fixed coefficients modified, the display or viewer specific can be fixed. The modified brightness setting variable is a mirror image subjective perception of brightness. With this modified brightness setting variable Then the switching times of the cells from the control circuit certainly.

Vorteilhafte Weiterbildungen des erfindungsgemäßen Verfahrens sind in den Ansprüchen 2 bis 7, vorteilhafte Ausgestaltungen der Erfindung in den Ansprüchen 9 bis 12 angegeben.Advantageous developments of the method according to the invention are in the Claims 2 to 7, advantageous embodiments of the invention in the claims 9 to 12 indicated.

Die Erfindung wird nachfolgend anhand des einzigen Blockschaltbildes ergänzend erläutert.The invention is described below using the single block diagram additionally explained.

Das Blockschaltbild zeigt einen Videoprozessor 1, in welchem das Video-Eingangssignal, das am Eingang 2 anliegt, durch ein Helligkeitssignal, das an einem Eingang 3 eines Mikroprozessors 4 anliegt, modifiziert wird. Dieses Helligkeitssignal wird vom Mikroprozessor 4 digitalisiert, falls es noch nicht in digitaler Form anliegt, und einer Koeffenzientenbewertung unterworfen, so daß bei linearer Veränderung des Helligkeitssignals über einen I2C- Bus 5 dem Videoprozessor ein modifiziertes Helligkeitssignal zugeführt wird, das dem subjektiven Helligkeitsempfinden entspricht. Die Signalamplituden, bezogen auf den Eingangswert des Helligkeitssignals, sind in der im Video-prozessor eingezeichneten Kurve ersichtlich. Entsprechend der Funktion (y = f (x)) wird eine nichtlineare Korrektur im unteren Bereich (Schwarz-Bereich) stärker vorgenommen als im oberen Bereich (helleren Bereich). Dadurch wird ein Übersteuern der Zelle vermieden, da die Maximalaussteuerung abweichend von konventionellen Helligkeitseinstellungen nicht überschritten wird. Das durch Multiplikation oder Addition erhaltene Video-Ausgangssignal entspricht also stets einer Größe, die unterhalb der maximalen Aussteuerungsgröße der einzelnen Zelle liegt. Der Ausgang 6 ist mit der nicht dargestellten Steuerschaltung verbunden, die die Zelle ansteuert.The block diagram shows a video processor 1, in which the video input signal which is present at input 2 is modified by a brightness signal which is present at an input 3 of a microprocessor 4. This brightness signal is digitized by the microprocessor 4, if it is not yet in digital form, and subjected to a coefficient evaluation, so that when the brightness signal changes linearly via an I 2 C bus 5, the video processor is supplied with a modified brightness signal that corresponds to the subjective perception of brightness . The signal amplitudes, based on the input value of the brightness signal, can be seen in the curve drawn in the video processor. According to the function ( y = f (x) ) a non-linear correction is made more strongly in the lower area (black area) than in the upper area (lighter area). This prevents the cell from being overdriven, since the maximum modulation does not exceed conventional brightness settings. The video output signal obtained by multiplication or addition therefore always corresponds to a size which is below the maximum modulation size of the individual cell. The output 6 is connected to the control circuit, not shown, which drives the cell.

Claims (12)

Verfahren zur Einstellung der Helligkeit einer Zelle eines Flachdisplays, die durch zeitliche Ansteuerung veränderbar ist, dadurch gekennzeichnet, daß unter Berücksichtigung des subjektiven Helligkeitsempfindens die Helligkeitseinstellgröße nicht linear verändert wird, und zwar in der Weise, daß sie im dunkleren Bereich höher ist als im helleren Bereich und unterhalb eines definierten Maximalwertes liegt.Method for adjusting the brightness of a cell of a flat display, which can be changed by time control, characterized in that taking the subjective brightness perception into account, the brightness setting variable is not changed linearly, in such a way that it is higher in the darker area than in the lighter area and is below a defined maximum value. Verfahren nach Anspruch 1, dadurch gekennzeichnet, daß eine linear veränderbare Helligkeitseinstellgröße von einem Prozessor in Abhängigkeit von Funktionskoeffizienten in nicht lineare Werte umgerechnet wird und diese Werte einem digitalen oder analogen Video-Eingangssignal hinzugefügt werden, und daß das so gebildete Video-Ausgangssignal der Steuerschaltung für die Zelle zugeführt wird.Method according to Claim 1, characterized in that a linearly variable brightness adjustment variable is converted into non-linear values by a processor as a function of function coefficients and these values are added to a digital or analog video input signal, and in that the video output signal thus formed is sent to the control circuit for the cell is fed. Verfahren nach Anspruch 2, dadurch gekennzeichnet, daß eine analoge Signalverarbeitung vorgesehen ist und daß das analoge Video-Ausgangssignal digitalisiert wird, und daß in Abhängigkeit vom jeweiligen Digitalwert die zeitliche Ansteuerung der Zelle verändert wird.A method according to claim 2, characterized in that analog signal processing is provided and that the analog video output signal is digitized and that the timing of the cell is changed as a function of the respective digital value. Verfahren nach Anspruch 2, dadurch gekennzeichnet, daß eine digitale Signalverarbeitung vorgesehen ist, und daß dem digitalisierten Video-Eingangssignal eine digitalisierte Helligkeitseinstellgröße hinzugefügt wird.Method according to Claim 2, characterized in that digital signal processing is provided and in that a digitized brightness adjustment variable is added to the digitized video input signal. Verfahren nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, daß die Helligkeitseinstellgröße aus einem Spannungs- oder Stromwert abgeleitet wird.Method according to one of the preceding claims, characterized in that the brightness setting variable is derived from a voltage or current value. Verfahren nach Anspruch 3 oder 4, dadurch gekennzeichnet, daß die Helligkeitseinstellgröße als Analogwert von einem nicht linearen Spannungsteiler abgegriffen wird. Method according to claim 3 or 4, characterized in that the brightness setting variable is tapped as an analog value from a non-linear voltage divider. Schaltungsanordnung nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, daß die Helligkeit des Video-Ausgangssignals gemäß folgender Formel modifiziert wird: y = 255 x x 255 (z) wobei y die Helligkeit des Video-Ausgangssignals, x die Helligkeitseinstellgröße z der Koeffizient, z.B. 0,7, ist. Circuit arrangement according to one of the preceding claims, characterized in that the brightness of the video output signal is modified according to the following formula: y = 255 x x 255 (z) in which y the brightness of the video output signal, x the brightness setting variable z is the coefficient, for example 0.7. Schaltungsanordnung zur Durchführung des Verfahrens nach Anspruch 1, gekennzeichnet durch einen analogen oder digitalen Videoprozessor, eine weitere oder integrierte Prozessorschaltung zur Aufbereitung und/oder Änderung der Helligkeitseinstellwerte unter Zugriff auf vorgegebene Koeffizienten, die in einem Speicher abrufbar und bestimmten Einstellwerten zugeordnet sind, und eine Überlagerungsstufe, in der dem analogen oder digitalen Video-Eingangssignal bzw. dem bereits verarbeiteten Videosignal das modifizierte Helligkeitssignal hinzugefügt ist.Circuit arrangement for carrying out the method according to claim 1, characterized by an analog or digital video processor, a further or integrated processor circuit for processing and / or changing the brightness setting values with access to predetermined coefficients which can be called up in a memory and are assigned to specific setting values, and a superimposition level , in which the modified brightness signal is added to the analog or digital video input signal or the already processed video signal. Schaltungsanordnung nach Anspruch 8, dadurch gekennzeichnet, daß die Überlagerungsstufe eine Multiplikations- oder eine Additionsstufe ist.Circuit arrangement according to claim 8, characterized in that the superposition stage is a multiplication stage or an addition stage. Schaltungsanordnung nach Anspruch 8, dadurch gekennzeichnet, daß das Video-Ausgangssignal der Zeitsteuerschaltung zugeführt wird, die die Ansteuerzeit der Zelle in Abhängigkeit des modifizierten Helligkeitssignals bestimmt.Circuit arrangement according to Claim 8, characterized in that the video output signal is fed to the time control circuit which determines the activation time of the cell as a function of the modified brightness signal. Schaltungsanordnung nach Anspruch 8 in Verbindung mit dem Verfahren nach Anspruch 6, dadurch gekennzeichnet, daß ein Potentiometer mit nicht linearer Kennlinie zur Einstellung der Helligkeitseinstellgröße vorgesehen ist.Circuit arrangement according to Claim 8 in connection with the method according to Claim 6, characterized in that a potentiometer with a non-linear characteristic curve is provided for setting the brightness setting variable. Schaltungsanordnung nach einem der Ansprüche 8 bis 11, gekennzeichnet durch die Verwendung bei einem Plasma-Display.Circuit arrangement according to one of claims 8 to 11, characterized by the use in a plasma display.
EP99119311A 1998-10-01 1999-09-29 Method of adjusting the light intensity of a cell of a flat panel display Withdrawn EP0992972A3 (en)

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DE19845187 1998-10-01
DE1998145187 DE19845187A1 (en) 1998-10-01 1998-10-01 Method for adjusting the brightness of a cell on a flat display

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EP0992972A2 true EP0992972A2 (en) 2000-04-12
EP0992972A3 EP0992972A3 (en) 2000-10-25

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1217599A2 (en) * 2000-12-22 2002-06-26 Visteon Global Technologies, Inc. Variable resolution control system and method for a display device
CN100452134C (en) * 2004-12-03 2009-01-14 惠普开发有限公司 Methods and systems to control electronic display brightness

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1762353A1 (en) * 1967-06-01 1970-04-30 Thomson Houston Comp Francaise Circuit for adjustable gamma correction in a television system
US4589022A (en) * 1983-11-28 1986-05-13 General Electric Company Brightness control system for CRT video display
JPH05100652A (en) * 1991-10-04 1993-04-23 Kokusai Electric Co Ltd Brightness characteristic controller for display unit
EP0614321A2 (en) * 1993-03-02 1994-09-07 Fujitsu General Limited Color display unit with plasma display panel
US5754150A (en) * 1995-02-17 1998-05-19 Sharp Kabushiki Kaisha Liquid crystal luminance adjusting apparatus
US5757343A (en) * 1995-04-14 1998-05-26 Pioneer Electronic Corporation Apparatus allowing continuous adjustment of luminance of a plasma display panel

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0437263A (en) * 1990-05-31 1992-02-07 Matsushita Electric Ind Co Ltd Gradation correction device
DE4217594A1 (en) * 1992-05-27 1993-12-02 Siemens Nixdorf Inf Syst Brightness and-or contrast control for VDU - has control matrix in front of screen control, with photosensitive sensor circuit for luminance value
US6362835B1 (en) * 1993-11-23 2002-03-26 Texas Instruments Incorporated Brightness and contrast control for a digital pulse-width modulated display system
DE19509035B4 (en) * 1994-03-23 2007-06-28 Carl Zeiss Optronics Gmbh Method for controlling the brightness of a screen display and device, in particular thermal imaging device, with it
DE19720876A1 (en) * 1997-05-17 1998-11-19 Grundig Ag Method and device for adjusting the contrast in pulse-width-controlled image displays
DE19721984C2 (en) * 1997-05-26 1999-10-07 Siemens Ag monitor

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1762353A1 (en) * 1967-06-01 1970-04-30 Thomson Houston Comp Francaise Circuit for adjustable gamma correction in a television system
US4589022A (en) * 1983-11-28 1986-05-13 General Electric Company Brightness control system for CRT video display
JPH05100652A (en) * 1991-10-04 1993-04-23 Kokusai Electric Co Ltd Brightness characteristic controller for display unit
EP0614321A2 (en) * 1993-03-02 1994-09-07 Fujitsu General Limited Color display unit with plasma display panel
US5754150A (en) * 1995-02-17 1998-05-19 Sharp Kabushiki Kaisha Liquid crystal luminance adjusting apparatus
US5757343A (en) * 1995-04-14 1998-05-26 Pioneer Electronic Corporation Apparatus allowing continuous adjustment of luminance of a plasma display panel

Non-Patent Citations (5)

* Cited by examiner, † Cited by third party
Title
COREL CORPORATION: "COREL DRAW! 4", 1993, COREL CORPORATION, DEUTSCHLAND, SEITEN 405-406 *
HUNT, R. W. G.: "The Reproduction of Colour", 1995, FOUNTAIN PRESS, KINGSTON-UPON-THAMES, ENGLAND, SEITEN 455-458 *
NEUMEYER, HEICO: "PAINT SHOP PRO 5", 1999, WILHELM HEYNE, MUENCHEN, SEITEN 17, 207-208, 425; SOFTWARE SEIT 09/1998 IN DEUTSCHLAND FREI VERFUEGBAR *
PATENT ABSTRACTS OF JAPAN vol. 017, no. 451 (P-1595), 18. August 1993 (1993-08-18) -& JP 05 100652 A (KOKUSAI ELECTRIC CO LTD), 23. April 1993 (1993-04-23) *
PATTERSON, RICHARD: 'Gamma Correction and Tone Reproduction in Scanned Photographic Images' SMTPE JOURNAL Bd. 103, Nr. 6, Juni 1994, WHITE PLAINS, NY (USA), Seiten 377 - 385, XP000457571 *

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1217599A2 (en) * 2000-12-22 2002-06-26 Visteon Global Technologies, Inc. Variable resolution control system and method for a display device
EP1217599A3 (en) * 2000-12-22 2004-12-01 Visteon Global Technologies, Inc. Variable resolution control system and method for a display device
CN100452134C (en) * 2004-12-03 2009-01-14 惠普开发有限公司 Methods and systems to control electronic display brightness

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EP0992972A3 (en) 2000-10-25
DE19845187A1 (en) 2000-04-13

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