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KR101338984B1 - Circuit for controlling common voltage in liquid crystal display and controlling method of the same - Google Patents

Circuit for controlling common voltage in liquid crystal display and controlling method of the same Download PDF

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KR101338984B1
KR101338984B1 KR1020060088261A KR20060088261A KR101338984B1 KR 101338984 B1 KR101338984 B1 KR 101338984B1 KR 1020060088261 A KR1020060088261 A KR 1020060088261A KR 20060088261 A KR20060088261 A KR 20060088261A KR 101338984 B1 KR101338984 B1 KR 101338984B1
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common voltage
resistors
liquid crystal
common
voltage
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KR20080024008A (en
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김영주
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엘지디스플레이 주식회사
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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
    • G09G3/3655—Details of drivers for counter electrodes, e.g. common electrodes for pixel capacitors or supplementary storage capacitors
    • G—PHYSICS
    • G08—SIGNALLING
    • G08C—TRANSMISSION SYSTEMS FOR MEASURED VALUES, CONTROL OR SIMILAR SIGNALS
    • G08C19/00—Electric signal transmission systems
    • G08C19/02—Electric signal transmission systems in which the signal transmitted is magnitude of current or voltage
    • G08C19/04—Electric signal transmission systems in which the signal transmitted is magnitude of current or voltage using variable resistance
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M3/00—Conversion of DC power input into DC power output
    • H02M3/02—Conversion of DC power input into DC power output without intermediate conversion into AC
    • H02M3/04—Conversion of DC power input into DC power output without intermediate conversion into AC by static converters
    • H02M3/06—Conversion of DC power input into DC power output without intermediate conversion into AC by static converters using resistors or capacitors, e.g. potential divider
    • 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
    • G09G2320/0209—Crosstalk reduction, i.e. to reduce direct or indirect influences of signals directed to a certain pixel of the displayed image on other pixels of said image, inclusive of influences affecting pixels in different frames or fields or sub-images which constitute a same image, e.g. left and right images of a stereoscopic display
    • 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
    • G09G2320/0247—Flicker reduction other than flicker reduction circuits used for single beam cathode-ray tubes

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

Abstract

본 발명은 액정표시장치에서 복수 단의 가변저항을 이용하여 공통전압을 보다 세밀하게 조절할 수 있도록 한 기술에 관한 것이다. 이러한 본 발명은, 액정 패널의 각 게이트 라인에 게이트 온 신호를 공급하는 게이트 구동부 및, 각 데이터 라인에 데이터 신호를 공급하는 데이터 구동부와; 상기 게이트 구동부 및 데이터 구동부에 의해 구동되어 화상을 표시하는 액정패널과; 전원단자와 접지단자 사이에 직렬접속된 저항 중 하나의 가변저항을 이용하여 공통전압을 1차적으로 조절하고, 상기 직렬접속된 저항에 병렬접속된 저항들 중 하나의 가변저항을 이용하여 그 공통전압을 2차적으로 정밀하게 조절하는 공통전압 생성부에 의해 달성된다.The present invention relates to a technique for more precisely controlling the common voltage by using a variable resistor of a plurality of stages in a liquid crystal display device. The present invention includes a gate driver for supplying a gate-on signal to each gate line of the liquid crystal panel, and a data driver for supplying a data signal to each data line; A liquid crystal panel driven by the gate driver and data driver to display an image; The common voltage is adjusted primarily by using a variable resistor of one of the resistors connected in series between the power supply terminal and the ground terminal, and the common voltage using one of the variable resistors connected in parallel to the series connected resistor. Is achieved by a common voltage generator that precisely regulates < RTI ID = 0.0 >

Description

액정표시장치의 공통전압 조절회로 및 공통전압 조절방법{CIRCUIT FOR CONTROLLING COMMON VOLTAGE IN LIQUID CRYSTAL DISPLAY AND CONTROLLING METHOD OF THE SAME}CIRCUIT FOR CONTROLLING COMMON VOLTAGE IN LIQUID CRYSTAL DISPLAY AND CONTROLLING METHOD OF THE SAME}

도 1은 종래 기술에 의한 공통전압 생성회로도.1 is a common voltage generation circuit diagram according to the prior art.

도 2는 본 발명에 의한 공통전압 조절회로가 적용된 액정표시장치의 블록도. 2 is a block diagram of a liquid crystal display device to which a common voltage adjusting circuit according to the present invention is applied.

도 3은 본 발명에 의한 공통전압 조절회로도.Figure 3 is a common voltage control circuit diagram according to the present invention.

***도면의 주요 부분에 대한 부호의 설명*** DESCRIPTION OF THE REFERENCE SYMBOLS

21 : 시스템 22 : 타이밍 콘트롤러21: system 22: timing controller

23 : 게이트 구동부 24 : 데이터 구동부23: gate driver 24: data driver

25 : 액정패널 26 : 직류/직류변환기25 liquid crystal panel 26 DC / DC converter

27 : 공통전압 생성부27: common voltage generator

본 발명은 액정표시장치에서 공통전압을 세밀하게 조절할 수 있도록 한 기술에 관한 것으로, 특히 복수 단의 가변저항을 이용하여 공통전압을 보다 세밀하게 조절할 수 있도록 한 액정표시장치의 공통전압 조절회로에 관한 것이다. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technology for finely controlling the common voltage in a liquid crystal display device, and more particularly, to a common voltage control circuit for a liquid crystal display device in which the common voltage can be finely controlled using a plurality of variable resistors. will be.

일반적으로, 액정표시장치(LCD)에서는 액정패널의 공통전극에 공통전압을 공 급하는 공통전압 생성부를 구비하게 된다.In general, a liquid crystal display (LCD) includes a common voltage generator supplying a common voltage to a common electrode of a liquid crystal panel.

도 1은 종래 기술에 의한 공통전압 생성 회로도로서 이에 도시한 바와 같이, 전원단자(Vdd)와 접지단자 사이에 콘덴서(C11),(C12), 직렬접속된 저항 및 가변저항(R11),(R12),(VR11)이 병렬로 접속되고, 상기 저항(R11),(R12)의 공통접속점으로부터 공통전압(Vcom)이 출력되도록 구성된 것으로, 이의 작용을 설명하면 다음과 같다.1 is a circuit diagram of a common voltage generation according to the prior art, as shown therein, a capacitor C11, C12, a series connected resistor and a variable resistor R11, and R12 between a power supply terminal Vdd and a ground terminal. ) And (VR11) are connected in parallel, and configured to output the common voltage Vcom from the common connection point of the resistors R11 and R12. The operation thereof will be described as follows.

전원단자(Vdd)와 접지단자 사이에 저항(R11),(R12)과 가변저항(VR11)이 직렬로 접속되고, 그 저항(R11),(R12)의 공통접속점이 공통전압(Vcom)의 출력단자에 연결되어 있다. 따라서, 상기 직렬접속된 저항(R11),(R12)과 가변저항(VR11)에 의해 분압된 전압이 상기 공통전압(Vcom)으로 출력된다. The resistors R11, R12 and the variable resistor VR11 are connected in series between the power supply terminal Vdd and the ground terminal, and the common connection point of the resistors R11, R12 is output of the common voltage Vcom. It is connected to the terminal. Accordingly, the voltage divided by the series connected resistors R11 and R12 and the variable resistor VR11 is output to the common voltage Vcom.

상기 공통전압(Vcom)은 원래 요구된 전압레벨로 출력할 필요가 있지만, 회로 구성요소의 오차나 시스템의 환경변화에 의해 정확하게 원래 요구된 전압레벨로 출력되는데 어려움이 있다.The common voltage Vcom needs to be output at the originally required voltage level, but it is difficult to output at the originally required voltage level precisely due to an error in a circuit component or an environment change of the system.

따라서, 상기 가변저항(VR1)을 조정하여 원래 요구된 전압레벨에 근접된 공통전압(Vcom)이 출력되도록 하고 있다.Therefore, the variable resistor VR1 is adjusted to output the common voltage Vcom that is close to the originally required voltage level.

그러나, 이와 같이 하나의 가변저항을 이용하여 수동으로 공통전압의 레벨을 정확하게 조절하는데 어려움이 있었다. 이에 따라, 공통전압 조정 편차가 발생되고, 이에 의해 플리커(flicker), 크로스토크(crosstalk)와 같은 현상이 발생되는 문제점이 있었다.However, there was a difficulty in manually adjusting the level of the common voltage manually by using one variable resistor. Accordingly, a common voltage adjustment deviation occurs, thereby causing a problem such as flicker and crosstalk.

따라서, 본 발명의 목적은 첫 번째 단의 가변저항을 이용하여 공통전압을 1차적으로 조정하고, 그 다음 단의 가변저항을 이용하여 공통전압을 2차적으로 정밀하게 조절하는 조절 회로를 제공함에 있다.Accordingly, an object of the present invention is to provide a regulating circuit for adjusting the common voltage first by using the variable resistor of the first stage and precisely adjusting the common voltage second by using the variable resistor of the next stage. .

상기와 같은 목적을 달성하기 위한 본 발명은, 액정 패널의 각 게이트 라인에 게이트 온 신호를 공급하는 게이트 구동부 및, 각 데이터 라인에 데이터 신호를 공급하는 데이터 구동부와; 상기 게이트 구동부 및 데이터 구동부에 의해 구동되어 화상을 표시하는 액정패널과; 전원단자와 접지단자 사이에 직렬접속된 저항 중 하나의 가변저항을 이용하여 공통전압을 1차적으로 조절하고, 상기 직렬접속된 저항에 병렬접속된 저항들 중 하나의 가변저항을 이용하여 그 공통전압을 2차적으로 정밀하게 조절하는 공통전압 생성부를 포함하여 구성함을 특징으로 한다.The present invention for achieving the above object, the gate driver for supplying a gate-on signal to each gate line of the liquid crystal panel, and a data driver for supplying a data signal to each data line; A liquid crystal panel driven by the gate driver and data driver to display an image; The common voltage is adjusted primarily by using a variable resistor of one of the resistors connected in series between the power supply terminal and the ground terminal, and the common voltage using one of the variable resistors connected in parallel to the series connected resistor. Characterized in that it comprises a common voltage generator for precisely adjusting the second.

이하, 첨부한 도면을 참조하여 본 발명에 따른 바람직한 실시예를 상세히 설명한다.Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

도 2는 본 발명에 의한 액정표시장치의 공통전압 조절회로의 일실시 구현 예시도로서 이에 도시한 바와 같이, 시스템(21)과; 데이터 신호와 게이트 온 신호에 의해 구동되어 화상을 표시하는 액정패널(25)과; 상기 액정 패널(25)의 각 게이트 라인에 게이트 온 신호를 공급하는 게이트 구동부(23)와; 상기 액정 패널(25)의 각 데이터 라인에 상기 데이터 신호를 공급하는 데이터 구동부(24)와; 상기 게이트 구동부(23) 및 데이터 구동부(24)의 구동을 제어하기 위한 제어신호를 출력하는 타이밍 콘트롤러(22)와; 상기 액정패널(25)에서 필요로 하는 각종 구동전압을 발생하기 위한 직류/직류 변환기(26)와; 전원단자와 접지단자 사이에 직렬접속된 저항 중 하나의 가변저항을 이용하여 공통전압을 1차적으로 조절하고, 상기 직렬접속된 저항에 병렬접속된 직렬저항 중 또 다른 가변저항을 이용하여 공통전압을 2차적으로 정밀하게 조절하는 공통전압 생성부(27)를 포함하여 구성하였다.FIG. 2 is a diagram showing an embodiment of a common voltage adjusting circuit of a liquid crystal display according to the present invention. As shown in FIG. A liquid crystal panel 25 driven by a data signal and a gate-on signal to display an image; A gate driver 23 for supplying a gate-on signal to each gate line of the liquid crystal panel 25; A data driver 24 for supplying the data signal to each data line of the liquid crystal panel 25; A timing controller 22 outputting a control signal for controlling the driving of the gate driver 23 and the data driver 24; A DC / DC converter 26 for generating various driving voltages required by the liquid crystal panel 25; The common voltage is primarily controlled by using a variable resistor of one of the resistors connected in series between the power supply terminal and the ground terminal, and the common voltage is adjusted using another variable resistor among the series resistors connected in parallel to the series connected resistor. It was configured to include a common voltage generator 27 to precisely control the secondary.

도 3은 상기 공통전압 생성부(27)의 상세 회로도로서 이에 도시한 바와 같이, 전원단자(VDD)와 접지단자 사이에 각각의 콘덴서(C31),(C32)와 직렬접속된 저항 및 가변저항(R31),(R32),(VR31)을 병렬로 접속하고, 상기 저항(R31),(R32)의 접속점(N1)과 접지단자 사이에 직렬접속된 저항 및 가변저항(R33),(R34),(VR32)을 병렬접속한 후, 상기 저항(R33),(R34)의 접속점(N2)을 공통전압 출력단자(Vcom)에 접속하여 구성하였다. FIG. 3 is a detailed circuit diagram of the common voltage generator 27. As shown therein, resistors and variable resistors connected in series with capacitors C31 and C32 between a power supply terminal V DD and a ground terminal, respectively. (R31), (R32), (VR31) are connected in parallel, and a resistor and a variable resistor (R33), (R34) connected in series between the connection point (N1) of the resistors (R31) and (R32) and the ground terminal. (VR32) was connected in parallel, and the connection point (N2) of the resistors (R33) and (R34) was connected to the common voltage output terminal (Vcom).

이와 같이 구성한 본 발명의 작용을 상세히 설명하면 다음과 같다.Referring to the operation of the present invention configured in this way in detail as follows.

액정패널(25)은 데이터라인(D1∼Dm)과 게이트라인(G1∼Gn)의 교차부에 매트릭스 형태로 배치되는 다수의 액정셀(Clc)을 구비한다. 상기 액정셀(Clc)에 각기 형성된 TFT는 게이트라인(G)으로부터 공급되는 스캔신호에 응답하여 데이터라인(D1∼Dm)으로부터 입력되는 데이터전압을 액정셀(Clc)에 전달한다. 또한 상기 액정셀(Clc) 각각에는 스토리지 캐패시터(Cst)가 형성되는데, 이는 그 액정셀(Clc)의 화소전극과 전단 게이트라인 사이에 형성되거나, 액정셀(Clc)의 화소전극과 공통전극 사이에 형성되어 액정셀(Clc)의 전압을 일정하게 유지시키는 역할을 수행한다. The liquid crystal panel 25 includes a plurality of liquid crystal cells Clc arranged in a matrix at the intersection of the data lines D1 to Dm and the gate lines G1 to Gn. Each TFT formed in the liquid crystal cell Clc transfers a data voltage input from the data lines D1 to Dm to the liquid crystal cell Clc in response to a scan signal supplied from the gate line G. In addition, a storage capacitor Cst is formed in each of the liquid crystal cells Clc, which is formed between the pixel electrode of the liquid crystal cell Clc and the front gate line, or between the pixel electrode and the common electrode of the liquid crystal cell Clc. It is formed to maintain a constant voltage of the liquid crystal cell (Clc).

시스템(21)의 그래픽 처리회로는 아날로그 데이터를 디지털 비디오 데이 터(RGB)로 변환함과 아울러 그 디지털 비디오 데이터(RGB)의 해상도와 색온도를 조정한다. 그리고, 이 시스템(21)으로부터 출력되는 디지털 비디오 데이터(RGB)와 수직/수평 동기신호 및 클럭신호가 타이밍 콘트롤러(22)에 공급된다.The graphics processing circuit of the system 21 converts analog data into digital video data (RGB) and adjusts the resolution and color temperature of the digital video data (RGB). The digital video data RGB and the vertical / horizontal synchronization signal and the clock signal output from the system 21 are supplied to the timing controller 22.

상기 타이밍 콘트롤러(22)는 상기 시스템(21)으로부터 공급되는 수직/수평 동기신호와 클럭신호를 이용하여 게이트 구동부(23)를 제어하기 위한 게이트 제어신호(GDC)와 데이터 구동부(24)를 제어하기 위한 데이터 제어신호(DDC)를 발생한다. 또한, 상기 타이밍 콘트롤러(22)는 상기 시스템(21)으로부터 입력되는 디지털 비디오 데이터(RGB)를 샘플링한 후에 재정렬하여 데이터 구동부(24)에 공급한다.The timing controller 22 controls the gate control signal GDC and the data driver 24 for controlling the gate driver 23 using the vertical / horizontal synchronization signal and the clock signal supplied from the system 21. To generate a data control signal DDC. In addition, the timing controller 22 samples the digital video data RGB input from the system 21 and rearranges the digital video data RGB to be supplied to the data driver 24.

상기 데이터 구동부(24)는 상기 타이밍 콘트롤러(22)로부터의 데이터 제어신호(DDC)에 응답하여 디지털 비디오 데이터(RGB)를 계조값에 대응하는 데이터전압(아날로그 감마보상전압)으로 변환하고, 이렇게 변환된 데이터전압이 액정패널(25)상의 데이터라인(D1∼Dm)에 공급된다. The data driver 24 converts the digital video data RGB into a data voltage (analog gamma compensation voltage) corresponding to the gray scale value in response to the data control signal DDC from the timing controller 22. The supplied data voltage is supplied to the data lines D1 to Dm on the liquid crystal panel 25.

상기 게이트 구동부(23)는 상기 타이밍 콘트롤러(22)로부터의 게이트 제어신호(GDC)에 응답하여 스캔펄스(게이트펄스)를 게이트라인(G1∼Gn)에 순차적으로 공급하여 데이터가 공급되는 액정패널(25)의 수평라인들을 선택한다. The gate driver 23 sequentially supplies scan pulses (gate pulses) to the gate lines G1 to Gn in response to the gate control signal GDC from the timing controller 22 to supply data. 25 select horizontal lines.

참고로, 상기 설명에서는 데이터 구동부(24)와 게이트 구동부(23)가 액정패널(25)과 분리 설치된 것으로 설명하였으나, 근래 들어 COG(COG: Chip On Glass) 또는 COF(COF: Chip On Film 또는 Chip On Flexible Printed Circuit) 등의 패키징 기술을 이용하여 액정패널(25)상에 직접 실장되는 추세에 있다.For reference, in the above description, the data driver 24 and the gate driver 23 are separately installed from the liquid crystal panel 25. However, in recent years, the chip on glass (COG) or the chip on film or chip (COF) has been recently installed. There is a trend that is directly mounted on the liquid crystal panel 25 using a packaging technology such as On Flexible Printed Circuit.

직류/직류 변환기(26)는 상기 시스템(21)으로부터의 VCC 전압을 이용하여 고 전위 공통전압인 VDD 전압, VCOM 전압, 게이트 온(또는 하이)전압 VGH, 게이트 오프(또는 로우)전압 VGL을 발생한다. The DC / DC converter 26 generates a high potential common voltage VDD voltage, VCOM voltage, gate on (or high) voltage VGH, and gate off (or low) voltage VGL using the VCC voltage from the system 21. do.

한편, 공통전압 생성부(27)는 소정 레벨의 공통전압(Vcom)을 생성하여 상기 액정패널(25)의 공통전극에 공급함에 있어서, 첫 번째 단의 공통전압 조절회로를 이용하여 그 공통전압(Vcom)을 목표치에 근접시킨 후, 두 번째 단의 공통전압 조절회로를 이용하여 공통전압(Vcom)을 목표치에 거의 일치시키게 되는데, 이의 작용을 첨부한 도 3을 참조하여 좀 더 상세히 설명하면 다음과 같다.Meanwhile, the common voltage generator 27 generates a common voltage Vcom having a predetermined level and supplies the common voltage Vcom to the common electrode of the liquid crystal panel 25 by using the common voltage control circuit of the first stage. After the Vcom) is close to the target value, the common voltage Vcom is almost coincided with the target value by using the common voltage regulating circuit of the second stage. Referring to FIG. same.

전원단자(VDD)와 접지단자 사이에, 저항 및 가변저항(R31),(R32),(VR31)이 직렬로 접속되고, 상기 저항(R31),(R32)의 접속점(N1)과 접지단자 사이에 직렬접속된 저항 및 가변저항(R33),(R34),(VR32)이 병렬로 접속되고, 그 저항(R33),(R34)의 접속점(N2)이 공통전압 출력단자(Vcom)에 접속되었다. 따라서, 사용자는 상기 두 개의 가변저항(VR31),(VR32)을 차례로 이용하여 상기 공통전압(Vcom)을 목표 전압레벨에 거의 일치시킬 수 있게 된다.A resistor and variable resistors R31, R32, and VR31 are connected in series between the power supply terminal V DD and the ground terminal, and the connection point N1 of the resistors R31 and R32 and the ground terminal are connected in series. The resistors connected in series and the variable resistors R33, R34, and VR32 are connected in parallel, and the connection points N2 of the resistors R33 and R34 are connected to the common voltage output terminal Vcom. It became. Accordingly, the user may use the two variable resistors VR31 and VR32 in turn to substantially match the common voltage Vcom to a target voltage level.

즉, 사용자는 상기 전원단자(VDD)와 접지단자 사이에, 직렬접속된 저항 및 가변저항(R31),(R32),(VR31) 중에서 가변저항(VR31)을 이용하여 통상의 경우와 같이 공통전압(Vcom)을 1차적으로 목표치에 근접되게 조절한다.That is, the user uses the variable resistor VR31 among the resistors connected in series and the variable resistors R31, R32, and VR31 between the power supply terminal V DD and the ground terminal as in the usual case, as in a normal case. The voltage Vcom is first adjusted to be close to the target value.

이후, 상기 직렬접속된 저항(R32) 및 가변저항(VR31)에 병렬로 접속되고, 서로 직렬 접속된 저항 및 가변저항(R33),(R34),(VR32) 중에서 가변저항(VR32)를 이용하여 상기 공통전압(Vcom)을 2차적으로 정밀 조정함으로써, 목표치에 거의 일치시킬 수 있게 된다.Thereafter, the resistor R32 and the variable resistor VR31 are connected in parallel, and the variable resistor VR32 is used among the resistors R33, R34, and VR32 connected in series with each other. By precisely adjusting the common voltage Vcom secondarily, it is possible to substantially match the target value.

참고로, 상기 도 3에서 콘덴서(C31),(C32)는 잡음성분 등에 의해 공통전압(Vcom)이 불안정하게 되는 것을 방지하기 위해 사용되었다.For reference, in FIG. 3, the capacitors C31 and C32 are used to prevent the common voltage Vcom from becoming unstable due to noise components.

이상에서 상세히 설명한 바와 같이 본 발명은 소정 레벨의 공통전압을 생성하여 액정패널의 공통전극에 공급함에 있어서, 첫 번째 단의 공통전압 조절소자를 이용하여 그 공통전압을 목표치에 근접시킨 후, 두 번째 단의 공통전압 조절소자를 이용하여 공통전압을 정밀하게 조절하여 목표치에 거의 일치시킬 수 있도록 함으로써, 플리커(flicker), 크로스토크(crosstalk)와 같은 현상이 발생되는 것을 방지할 수 있는 효과가 있다.As described in detail above, the present invention generates a common voltage of a predetermined level and supplies the common voltage to the common electrode of the liquid crystal panel. By using the common voltage adjusting element of the stage to precisely adjust the common voltage to almost match the target value, there is an effect that can prevent the phenomenon such as flicker, crosstalk (crosstalk) occurs.

Claims (6)

게이트 구동부 및 데이터 구동부에 의해 구동되어 화상을 표시하는 액정패널과 연결되며, It is connected to the liquid crystal panel which is driven by the gate driver and the data driver to display an image. 전원단자와 접지단자 사이에 직렬접속된 복수의 제1 저항 및 제1 가변저항; 및A plurality of first resistors and first variable resistors connected in series between a power supply terminal and a ground terminal; And 상기 복수의 제1 저항사이의 제1 노드와 상기 접지단자 사이에 병렬접속되고, 서로 직렬접속된 복수의 제2 저항 및 제2 가변저항으로 이루어지는 공통전압 생성부를 포함하고,A common voltage generator comprising a plurality of second resistors and a second variable resistor connected in parallel between the first node and the ground terminal between the plurality of first resistors, and connected in series with each other; 상기 공통전압 생성부는,Wherein the common- 상기 제1 가변저항의 조절된 저항값에 따라, 상기 제1 노드를 통해 제1 출력전압을 출력하고,Outputting a first output voltage through the first node according to the adjusted resistance value of the first variable resistor, 상기 제2 가변저항의 조절된 저항값에 따라, 상기 제1 출력전압과 접지전압 사이에서 설정된 제2 출력전압을 상기 복수의 제2 저항사이의 제2 노드를 통해 공통전압으로서 상기 액정패널에 출력하는 것Outputting the second output voltage set between the first output voltage and the ground voltage to the liquid crystal panel as a common voltage through a second node between the plurality of second resistors according to the adjusted resistance value of the second variable resistor. To do 을 특징으로 하는 액정표시장치의 공통전압 조절회로.A common voltage control circuit of a liquid crystal display device characterized in that. 삭제delete 삭제delete 제 1 항에 있어서,The method of claim 1, 상기 공통전압 생성부는,Wherein the common- 상기 복수의 제1 저항 및 제1 가변저항과 병렬접속되는 제1 및 제2 콘덴서를 더 포함하는 것을 특징으로 하는 액정표시장치의 공통전압 조절회로.And a first capacitor and a second capacitor connected in parallel with the plurality of first resistors and the first variable resistors. 전원단자와 접지단자 사이에 직렬접속된 복수의 제1 저항 및 제1 가변저항;A plurality of first resistors and first variable resistors connected in series between a power supply terminal and a ground terminal; 상기 복수의 제1 저항사이의 제1 노드와 상기 접지단자 사이에 병렬접속되고, 서로 직렬접속된 복수의 제2 저항 및 제2 가변저항으로 이루어지는 공통전압 생성부를 포함하고, 상기 복수의 제2 저항사이의 제2 노드를 통해 공통전압을 출력하는 공통전압 생성부를 포함하는 액정표시장치의 공통전압 조절방법으로서,A common voltage generator comprising a plurality of second resistors and a second variable resistor connected in parallel between a first node and the ground terminal between the plurality of first resistors, and connected in series with each other; A common voltage adjusting method of a liquid crystal display device including a common voltage generator for outputting a common voltage through a second node therebetween, 상기 제1 가변저항의 저항값을 조절하여 목표치에 근접한 제1 출력전압을 설정하는 단계;Setting a first output voltage close to a target value by adjusting a resistance value of the first variable resistor; 상기 제1 출력전압과 접지전압 사이에서 상기 제2 가변저항의 저항값을 조절하여 목표치에 해당하는 미세조절된 제2 출력전압을 설정하는 단계; 및Setting a second regulated output voltage corresponding to a target value by adjusting a resistance value of the second variable resistor between the first output voltage and the ground voltage; And 상기 제2 출력전압을 공통전압으로서 액정패널에 공급하는 단계Supplying the second output voltage to the liquid crystal panel as a common voltage 를 포함하는 액정표시장치의 공통전압 조절방법.Common voltage control method of the liquid crystal display comprising a. 제 5 항에 있어서,6. The method of claim 5, 상기 공통전압 생성부는,Wherein the common- 상기 복수의 제1 저항 및 제1 가변저항과 병렬접속되는 제1 및 제2 콘덴서를 더 포함하는 것을 특징으로 하는 액정표시장치의 공통전압 조절방법.And a first capacitor and a second capacitor connected in parallel with the plurality of first resistors and the first variable resistors.
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