KR20090005861A - Liquid crystal display - Google Patents

Liquid crystal display Download PDF

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Publication number
KR20090005861A
KR20090005861A KR1020070069239A KR20070069239A KR20090005861A KR 20090005861 A KR20090005861 A KR 20090005861A KR 1020070069239 A KR1020070069239 A KR 1020070069239A KR 20070069239 A KR20070069239 A KR 20070069239A KR 20090005861 A KR20090005861 A KR 20090005861A
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KR
South Korea
Prior art keywords
voltage
liquid crystal
gamma
crystal display
driving
Prior art date
Application number
KR1020070069239A
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Korean (ko)
Inventor
이경훈
Original Assignee
삼성전자주식회사
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Priority to KR1020070069239A priority Critical patent/KR20090005861A/en
Publication of KR20090005861A publication Critical patent/KR20090005861A/en

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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
    • G09G3/34—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 by control of light from an independent source
    • G09G3/36—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 by control of light from an independent source using liquid crystals
    • G09G3/3611—Control of matrices with row and column drivers
    • G09G3/3648—Control of matrices with row and column drivers using an active 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
    • G09G3/34—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 by control of light from an independent source
    • G09G3/36—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 by control of light from an independent source using liquid crystals
    • G09G3/3611—Control of matrices with row and column drivers
    • G09G3/3696—Generation of voltages supplied to electrode drivers
    • 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
    • G09G2320/0673—Adjustment of display parameters for control of gamma adjustment, e.g. selecting another gamma curve

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Computer Hardware Design (AREA)
  • General Physics & Mathematics (AREA)
  • Theoretical Computer Science (AREA)
  • Control Of Indicators Other Than Cathode Ray Tubes (AREA)

Abstract

The present invention includes a liquid crystal display panel for displaying an image, a driving voltage generator for generating driving power for driving the liquid crystal display panel, and a gamma voltage generator for generating a gamma power using the driving power. The power generator is provided with a first temperature compensator for variably controlling the voltage level of the driving power according to a temperature, and the gamma voltage generator is configured to control the voltage variation of the driving power by the first temperature compensator to remove the voltage variation. Provided are a liquid crystal display device having a temperature compensation unit.

 As described above, the gamma voltage generation unit includes a temperature compensating unit to remove the voltage fluctuation due to the variable power control of the driving power supply, that is, the analog voltage, thereby preventing the gamma characteristic from being deteriorated even if the voltage level of the analog voltage is varied. Can be.

Description

Liquid crystal display {LIQUID CRYSTAL DISPLAY}

The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device in which a voltage level of an analog voltage is varied according to a temperature environment.

Liquid crystal display is a display device that realizes an image by controlling the amount of light incident from a light source using the optical anisotropy of liquid crystal molecules and the polarization characteristics of a polarizing film. In recent years, its power consumption is small, and its application range is rapidly expanding.

A general liquid crystal display device includes a liquid crystal display panel, a driving voltage generator, a gate driver, a gamma voltage generator, a data driver, and a signal controller for controlling them. The driving voltage generation unit receives a predetermined power supply voltage PVDD and generates and outputs an analog voltage AVDD which is a reference for various driving power sources required for driving the liquid crystal display. The driving voltage generator generates a gate on voltage Von, a gate off voltage Voff, a common voltage Vcom, and the like based on the analog voltage. The gamma voltage generator generates a plurality of levels of gray voltages based on the reference voltage provided from the driving voltage generator.

Meanwhile, at least one thin film transistor formed of amorphous silicon is typically provided in each pixel of a general liquid crystal display panel. In particular, recently, a technique of directly forming a gate driver in a liquid crystal display panel using an amorphous silicon thin film transistor has been developed. However, in the case of the amorphous silicon thin film transistor, the operation characteristics are good in the room temperature environment, but the operation characteristics are significantly degraded in the low temperature environment. Therefore, it is necessary to variably control the voltage level of the gate-on signal Von according to the ambient temperature. To this end, in the related art, a temperature compensation circuit is additionally provided in the driving voltage generator to increase the output signal, that is, the voltage level of the analog voltage AVDD, so that the driving capability of the liquid crystal display may not be degraded even in a low temperature environment. Doing.

However, when the temperature compensation circuit is used, other voltages generated on the basis of the analog voltage AVDD are varied together. For example, when the analog voltage AVDD is used as the intermediate voltage of the gamma voltage generator, the voltage level GMAcnt of the intermediate gamma voltage is changed and shakes together with the analog voltage AVDD. There is a problem in that the display quality is lowered.

SUMMARY OF THE INVENTION The present invention has been made to overcome the above-described problems, and an object thereof is to provide a liquid crystal display device capable of preventing a deterioration of gamma characteristics due to a change in the voltage level of an analog voltage according to a temperature environment.

A liquid crystal display device according to the present invention for achieving the above object comprises a liquid crystal display panel for displaying an image, a drive voltage generation unit for generating a drive power required for driving the liquid crystal display panel, and gamma using the drive power source And a gamma voltage generator configured to generate power, wherein the drive power generator includes a first temperature compensator configured to variably control a voltage level of the drive power according to a temperature, and the gamma voltage generator includes the first temperature compensator. And a second temperature compensator for controlling to eliminate the voltage variation of the driving power supply.

The driving voltage generator includes a DC-DC converter for generating an analog voltage, a gate voltage generator for generating a gate voltage using the analog voltage, and a common voltage generator for generating a common voltage using the analog voltage. The first temperature compensator is preferably provided in the DC-DC converter.

The first temperature compensator preferably uses a resistance element in which a resistance value is changed according to an ambient temperature. For example, it may be configured by connecting a plurality of diodes. At this time, the temperature compensation rate of the first temperature compensator is controlled by the total number of diodes.

The gamma voltage generator is configured to generate a plurality of levels of gamma voltages by voltage-dividing the driving voltage by dividing the driving voltage to generate a first voltage, and by dividing the driving voltage by using the first voltage as an intermediate gamma value. And a second voltage generator, wherein the first temperature compensator is provided at an input front end of the first voltage divider.

The second temperature compensator preferably uses a resistance element in which a resistance value is changed according to an ambient temperature. For example, it may be configured by connecting a plurality of diodes. At this time, the temperature compensation rate of the second temperature compensator is controlled by the total number of diodes.

Preferably, the first and second temperature compensators are adjusted to have temperature compensation rates. For example, the first and second temperature compensators may be configured of the same number of diodes.

According to an exemplary embodiment of the present invention, the temperature compensation part is provided in the driving voltage generation unit so that the voltage level of the analog voltage is changed according to the temperature environment, so that the liquid crystal display can be smoothly driven even in a low temperature environment.

In addition, the present invention is provided with a temperature compensation unit in the gamma voltage generation unit to eliminate the voltage fluctuations due to the variable control of the analog voltage, thereby preventing the gamma characteristics from deteriorating even if the voltage level of the analog voltage is variable.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various forms, and only the embodiments are intended to complete the disclosure of the present invention, and to those skilled in the art to fully understand the scope of the invention. It is provided to inform you. Like reference numerals in the drawings refer to like elements.

1 is a block diagram of a liquid crystal display according to an exemplary embodiment of the present invention.

Referring to FIG. 1, the liquid crystal display according to the present exemplary embodiment includes a liquid crystal display panel 100 in which a plurality of pixels are arranged in a matrix, and a driving circuit 1000 for controlling operations of the pixels.

The liquid crystal display panel 100 includes a plurality of gate lines GL1 to GLn extending in one direction (approximately the row direction) and a plurality of data lines DL1 to DLm extending in the other direction (approximately the column direction). It includes a plurality of pixels provided in these intersection areas. Each pixel is provided with a thin film transistor (TFT), a liquid crystal capacitor (Clc), a storage capacitor (Cst), and the like. Here, the gate electrode of the thin film transistor TFT is connected to the gate line GL, the source electrode is connected to the data line DL, and the drain electrode is connected to the pixel electrode (not shown) of the liquid crystal capacitor Clc. .

The thin film transistor TFT is a switching element for independently controlling each pixel. The thin film transistor TFT is turned on according to a gate signal (or gate-on voltage Von) applied to the gate line GL, and is applied to the data line DL. The signal (or gray voltage) is supplied to the liquid crystal capacitor Clc and the sustain capacitor Cst. The liquid crystal capacitor Clc is composed of a liquid crystal layer (not shown) positioned as a dielectric between an opposing pixel electrode and a common electrode (not shown), and a data signal is charged during turn-on of the TFT. It controls the molecular arrangement. The sustain capacitor Cst is formed by forming an insulating layer between the opposite pixel electrode and the sustain electrode (not shown), and maintains the data signal charged in the liquid crystal capacitor Clc until the next data signal is charged. Play a role. The storage electrode of the storage capacitor Cst is connected to the storage line SL that extends substantially in parallel with the extending direction of the gate line GL. Of course, the sustain capacitor Cst and the sustain line SL may be omitted as necessary.

The driving voltage generator 200, the gate driver 300, the gamma voltage generator 400, the data driver 500, and a signal controller 600 for controlling them may be disposed outside the liquid crystal display panel 100. A liquid crystal drive circuit 1000 is included. Here, some circuits of the liquid crystal driving circuit 1000 may be directly formed in the liquid crystal display panel 100 in the outer region of the pixel region. For example, the gate driver 200 according to the present exemplary embodiment may be formed directly on the liquid crystal display panel 100 by a circuit forming method using an amorphous silicon thin film transistor, that is, an ASG (Armorphous Silicon Gate) method.

The signal controller 600 receives an input image signal and an input control signal from an external image controller (not shown). For example, an input image signal including image data R, G, and B, and a vertical synchronization signal Vsync, a horizontal synchronization signal Hsync, a main clock MCLK, and a data enable signal DE may be included. The input control signal is provided. In addition, the signal controller 200 processes the input image signal to suit the operating conditions of the liquid crystal display panel 100 to generate internal image data R ′, G ′, and B ′, and based on the input control signal. The gate control signal CONT1 and the data control signal CONT2 are generated. The gate control signal CONT1 is provided to the gate driver 300, and the vertical synchronization start signal STV, the gate clock signal CKV, and the gate on control signal OE which indicate the start of the output of the gate on voltage Von. ), Etc. The data control signal CONT2 is provided to the data driver 500, and the horizontal synchronization start signal STH indicating the start of transmission of the image data R ′, G ′, and B ′ and a data signal to the corresponding data line. A load signal LOAD to be applied and an inversion signal RVS for inverting the polarity of the gray scale voltage with respect to the common voltage, a data clock signal DCLK, and the like.

The driving voltage generator 200 generates various driving voltages for driving the liquid crystal display using the external driving power PVDD input from an external power supply (not shown). That is, the driving voltage generator 200 generates an analog voltage AVDD, a gate on voltage Von, a gate turnoff voltage Voff, and a common voltage Vcom. The driving voltage generator 200 provides the gate-on voltage Von and the gate turn-off voltage Voff to the gate driver 200 according to a control signal from the signal controller 600, and provides the common voltage to the liquid crystal display panel. In operation 100, the analog voltage AVDD is provided to the data driver 500. Here, the analog voltage AVDD is used as a reference voltage for generating the gate on voltage Von, the gate off voltage Voff, the common voltage Vcom, and the gray voltage GMA.

The gate driver 300 sequentially outputs the gate-on voltage Von of the driving voltage generator 200 to the gate lines G1 to Gn as a gate signal according to the control signal CONT1 of the signal controller 600. . In this case, the gate turn-off voltage Voff may be output while the gate-on voltage Von is not output. As a result, the operation of each thin film transistor TFT connected to each gate line G1 to Gn may be controlled.

The gamma voltage generator 400 generates a plurality of levels of gray voltage GMA using the analog voltage AVDD input from the driving voltage generator 200, and provides the same to the data driver 500. Here, although the gamma voltage generator 400 is manufactured as a separate module and provided outside the data driver 500, the gamma voltage generator 400 is not limited thereto and may be manufactured together with the data driver 500 to be described later.

The data driver 500 converts the digital pixel data R ', G' and B 'into an analog data signal according to the control signal CONT2 of the signal controller 600, and converts the analog data signal. Output to each data line DL1 to DLm. In this case, the pixel data R ', G', and B 'are converted into data signals using the gray scale voltage from the gamma voltage generator 200.

On the other hand, in the liquid crystal display having the above configuration, the above-described driving voltage generator 200 and gamma voltage generator 400 are provided with temperature compensation units, respectively. Hereinafter, the driving voltage generator 200 and the gamma voltage generator 400 will be described in more detail.

2 is a block diagram illustrating the driving voltage generator of FIG. 1, and FIG. 3 is a circuit diagram of the DC-DC converter of FIG. 2.

2 and 3, the driving voltage generator 200 may include a DC-DC converter 210 generating an analog voltage AVDD using an input DC power supply PVDD, and a gate-on voltage Von. And a gate voltage generator 220 generating a gate off voltage Voff and a common voltage generator 230 generating a common voltage Vcom.

2, the DC-DC converter includes a module converter 211, an inductor L1, a rectifier diode Z1, an input capacitor C1, an output capacitor C2, a voltage divider 212, and a temperature. Compensation unit 213 is included.

The module converter 211 includes an input terminal IN, a switch terminal SW, a feedback terminal FB, and a ground terminal GND, and includes a pulse generator 2111 and a switching element TR1. It is formed of an integrated circuit. The module converter 211 is enabled according to a predetermined driving voltage input to the input terminal IN. In addition, the switch terminal SW is connected to a connection node between the inductor L1 and the rectifier diode Z1, the ground terminal GND is connected to a ground power source, and the feedback terminal FB. ) Is connected to the temperature compensator 213. The switching element TR1 may include a transistor having a gate terminal connected to the pulse generator, a source terminal connected to the switch terminal, and a drain terminal connected to the ground terminal.

The inductor L1 is used to store the input charge and the diode Z1 is used to provide the input charge only to the output. In addition, the input capacitor C1 and the output capacitor C2 are used to provide the stabilized input voltage PVDD and the output voltage AVDD, respectively.

The voltage divider 212 includes second and third resistors R2 and R3 connected in series with each other, and is divided by voltage distribution of the output voltage AVDD by the second and third resistors R2 and R3. 1 Generate a feedback signal Vfb1. In this case, the first feedback signal Vfb1 is a voltage signal in which the output voltage AVDD is divided at the connection node between the second and third resistors R2 and R3.

The temperature compensator 213 increases and decreases the voltage level of the first feedback signal Vfb1 according to a temperature environment to generate a second feedback signal Vfb2, which is then fed back to the feedback terminal FB of the module converter 211. It is applied to the pulse signal generator 2111 through. The temperature compensator 213 may be configured as a resistance element whose resistance value is changed according to the ambient temperature. For example, the present embodiment consists of two diodes D1 and D2 connected in series. The diodes D1 and D2 have a characteristic that the resistance value increases as the ambient temperature decreases. Accordingly, the temperature compensator 213 generates the second feedback signal Vfb2 having a voltage level lower than the first feedback signal Vfb1 as the ambient temperature decreases, and provides the second feedback signal Vfb2 to the pulse signal generator 2111. Meanwhile, the temperature compensation rate of the first temperature compensator 213 is adjusted by the total number of diodes.

The pulse signal generator 2111 generates a square wave pulse signal Ps. When the transistor TR1 is turned on by the pulse signal Ps generated by the pulse signal generator 2111, a current path is formed between the input voltage PVDD and the ground voltage. As a result, the amount of current flowing in the inductor L1 increases in proportion to time. As the input voltage PVDD flows through the inductor L1, its energy is stored in the inductor L1. When the transistor TR1 is turned off by the pulse signal Ps, the current path between the input voltage PVDD and the ground voltage is blocked, and the current flowing through the inductor L1 is blocked. As a result, a high voltage is generated by the high energy back EMF in the inductor L1. The high voltage turns on the rectifier diode Z1 so that a current accumulated in the inductor L1 as a magnetic field flows through the rectifier diode Z1 to charge the output capacitor C2. The voltage charged in the output capacitor C2 is an analog voltage AVDD and is used as a reference voltage for generating various driving voltages required for driving the liquid crystal display.

In this operation, the pulse signal generator 2111 adjusts the duty ratio of the square wave pulse signal Ps so that the DC-DC converter 210 outputs a constant DC voltage (ie, analog voltage AVDD). do. In this case, the pulse signal generator 2111 adjusts the duty ratio of the square wave pulse signal Ps according to the second feedback signal Vfb2 output from the temperature compensator 213. In this case, since the second feedback signal Vfb2 is formed by using the first feedback signal Vfb1 according to the change of the output voltage, the output voltage of the DC-DC converter is constantly adjusted. In addition, since the voltage level of the second feedback signal Vfb2 is adjusted according to the change of the temperature environment, the output voltage of the DC-DC converter 210 increases or decreases according to the change of the temperature environment. As a result, the analog voltage AVDD output from the DC-DC converter 210 has a higher voltage level as the ambient temperature decreases.

4 is a circuit diagram illustrating a gamma voltage generator of FIG. 1.

Referring to FIG. 4, the gamma voltage generator 400 includes a first voltage divider 410, an amplifier 420, and a second voltage divider 430, and a first voltage divider 410. And a temperature compensator 440 connected to the input front end of the. The first voltage divider 410 generates n divided voltages through a plurality of resistors R111 and R112 connected in series between the input voltage Vin and the ground voltage. The amplifier 420 receives the n divided voltages and outputs n fixed voltages. The second voltage divider 430 generates a plurality of levels of gamma voltages GMA1 to GMA10 through the n fixed voltages and the plurality of resistors R211 to R222 connected in series between the input voltage Vin and the ground voltage. do. Here, the input voltage Vin is used as the analog voltage AVDD generated by the driving voltage generator 200, and n is an integer greater than or equal to '1'. For example, the first voltage divider 410 of the present embodiment divides the analog voltage AVDD through two resistors R111 and R112 connected in series to generate one divided voltage, and the amplifier 420. Receives one division voltage and outputs one fixed voltage. The second voltage divider 430 divides the reference voltage through 12 resistors R211 to R222 connected in series to generate ten gamma voltages GMA1 to GMA10. At this time, one fixed voltage output from the amplifier 420 is input to the connection node between the two resistors R216 and R217 positioned in the middle of the second voltage divider 430, and thus, the second voltage divider 430. Determine the median potential level of the gamma voltage (GMA) generated by That is, the second voltage divider 420 sets the analog voltage AVDD as the highest voltage, the ground voltage as the lowest voltage, and uses the fixed voltage input from the amplifier 420 as the intermediate voltage to divide the analog voltage. To generate plural levels of gamma voltages GMA1 to GMA10. Meanwhile, the temperature compensator 440 is connected to the front end of the first voltage divider 410 to control the voltage level of the input power source, that is, the analog voltage AVDD, to be changed according to temperature. The temperature compensator 440 may be configured as a resistance element whose resistance value is changed according to the ambient temperature. For example, it may be composed of a plurality of diodes, in which case the temperature compensation rate is adjusted by the number of diodes. In this embodiment, two diodes D111 and D112 are connected in series. The diodes D111 and D112 have a characteristic that the resistance value increases as the ambient temperature decreases. Accordingly, the input voltage, that is, the analog voltage AVDD, is input to the first voltage divider 410 by adjusting the voltage level according to the temperature environment, and accordingly, the voltage distribution condition of the second voltage divider 430 varies. The voltage level of the gamma voltage GMA output from the gamma voltage generator 400 is adjusted. In this case, the voltage level of the intermediate gamma voltage GMAcnt is preferably adjusted to be equal to the common voltage Vcom regardless of the temperature environment.

As such, the present embodiment includes a DC-DC converter 210 for generating an analog voltage AVDD and a gamma voltage generator 400 for generating a gamma voltage GMA by voltage-dividing the analog voltage AVDD. Temperature compensation units 213 and 440 are provided. In this case, the temperature compensator 213 of the DC-DC converter 210 controls the voltage level of the analog voltage AVDD according to the temperature environment so that the liquid crystal display panel 100 can be smoothly driven even in a low temperature environment. Do it. On the other hand, the temperature compensators 213 and 440 of the gamma voltage generator 400 control the voltage level of the analog voltage AVDD to be controlled by removing the variation of the voltage level due to the variable control of the analog voltage AVDD according to the temperature environment. Even if it is variable, the gamma characteristic is not degraded.

5 is a gamma graph of a liquid crystal display according to a comparative example of the present invention, and FIG. 6 is a gamma graph of the liquid crystal display according to an experimental example of the present invention. In FIG. 5 and FIG. 6, A line is a gamma graph measured in a high temperature environment, B line is a room temperature environment, and C line is a low temperature environment.

Referring to FIG. 5, in the case of a general liquid crystal display, since the intermediate gamma value GMAcnt is generated using the analog voltage AVDD that varies according to the ambient temperature, the gamma characteristic is severely degraded in the intermediate band, and more severely in a low temperature environment. It can be seen that the degradation. In contrast, referring to FIG. 6, in the liquid crystal display according to the present invention, since the median gamma value GMAcnt is generated using the analog voltage AVDD from which the voltage fluctuation due to the temperature change is removed, the gamma characteristic decreases in the intermediate band. It can be confirmed that the phenomenon has been overcome to some extent.

As mentioned above, although this invention was demonstrated with reference to the above-mentioned Example and an accompanying drawing, this invention is not limited to this, It is limited by the following claims. Therefore, it will be apparent to those skilled in the art that the present invention may be variously modified and modified without departing from the technical spirit of the following claims.

1 is a block diagram of a liquid crystal display according to an exemplary embodiment of the present invention.

FIG. 2 is a block diagram illustrating a driving voltage generator of FIG. 1. FIG.

3 is a circuit diagram illustrating the DC-DC converter of FIG. 2.

4 is a circuit diagram illustrating a gamma voltage generator of FIG. 1.

5 is a gamma graph of a liquid crystal display according to a comparative example of the present invention.

6 is a gamma graph of a liquid crystal display according to an experimental example of the present invention.

<Explanation of symbols for the main parts of the drawings>

100: liquid crystal display panel 200: driving voltage generation unit

300: gate driver 400: gamma voltage generator

500: data driver 600: signal controller

Claims (1)

A liquid crystal display panel which displays an image; A driving voltage generator configured to generate driving power for driving the liquid crystal display panel; A gamma voltage generator configured to generate gamma power using the driving power; Including, The driving power generator is provided with a first temperature compensator for variably controlling the voltage level of the driving power according to a temperature, and the gamma voltage generator is controlled to remove a voltage variation of the driving power by the first temperature compensator. And a second temperature compensator.
KR1020070069239A 2007-07-10 2007-07-10 Liquid crystal display KR20090005861A (en)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10373580B2 (en) 2016-05-27 2019-08-06 Samsung Display Co., Ltd. Display device having power reset mode
KR20200067389A (en) * 2018-12-04 2020-06-12 엘지디스플레이 주식회사 Micro display device and method for controlling luminance thereof

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10373580B2 (en) 2016-05-27 2019-08-06 Samsung Display Co., Ltd. Display device having power reset mode
US10650777B2 (en) 2016-05-27 2020-05-12 Samsung Display Co., Ltd. Display device having an inactive mode
KR20200067389A (en) * 2018-12-04 2020-06-12 엘지디스플레이 주식회사 Micro display device and method for controlling luminance thereof

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