CN101127195A

Movatterモバイル変換

Info

Publication number: CN101127195A
Application number: CNA2006101110983A
Authority: CN
Inventors: 黄信忠; 朱益男; 陈鸿祥; 黄俊颖
Original assignee: Chunghwa Picture Tubes Ltd
Current assignee: Chunghwa Picture Tubes Ltd
Priority date: 2006-08-15
Filing date: 2006-08-15
Publication date: 2008-02-20
Anticipated expiration: 2026-08-15
Also published as: CN100583222C

Abstract

The invention discloses a common voltage compensation device which is suitable for a display panel of a liquid crystal display and comprises a time sequence controller and a compensation circuit. The time schedule controller receives an image signal and generates a control signal to the compensation circuit according to a judgment mechanism. The compensation circuit transmits the common voltage compensation signal to the display panel according to the control signal of the timing controller to compensate the common voltage on the display panel. The judging mechanism analyzes the gray scale distribution of horizontal line signals in the image signals, judges whether common voltage compensation is needed or not according to the analysis result, and judges and determines the polarity of compensation to compensate when compensation is needed.

Description

Translated fromChinese

共用电压补偿装置、液晶显示器及其驱动方法Shared voltage compensation device, liquid crystal display and driving method thereof

技术领域technical field

本发明有关于一种液晶显示器，且特别有关于一种具有共用电压补偿的液晶显示器。The present invention relates to a liquid crystal display, and more particularly to a liquid crystal display with common voltage compensation.

背景技术Background technique

图1为现有的液晶显示器的像素(pixel)电路。请参照图1，在像素电路中，薄膜晶体管113的源极端116电性连接至源极配线101，栅极端114电性连接至栅极配线103，而漏极端115则透过并联的存储电容111与像素电极109电性连接至共用电极107。在液晶显示器中，因显示面板阵列电路先天制程的因素，源极配线101与共用电极107之间会存在一寄生电容105。FIG. 1 is a pixel circuit of a conventional liquid crystal display. Please refer to FIG. 1 , in the pixel circuit, thesource terminal 116 of thethin film transistor 113 is electrically connected to thesource wiring 101, thegate terminal 114 is electrically connected to thegate wiring 103, and thedrain terminal 115 is connected through a parallel memory Thecapacitor 111 and thepixel electrode 109 are electrically connected to thecommon electrode 107 . In a liquid crystal display, aparasitic capacitance 105 exists between thesource wiring 101 and thecommon electrode 107 due to inherent process factors of the display panel array circuit.

在上述寄生电容105的影响下，显示面板在显示一些特殊画面时，会因寄生电容105产生的耦合现象使得共用电极上的电压(以下称为共用电压)产生变化，导致显示面板在显示这些特殊画面会有辉度不均的现象，其中特殊画面可以是黑框、白框及其他灰阶框等。举例来说，在显示图2所示具有一黑框201的白画面时，在黑框201两侧区域202与203的辉度会因寄生电容105产生的耦合现象而不会与区域204或205的辉度相同。Under the influence of the above-mentionedparasitic capacitance 105, when the display panel displays some special images, the voltage on the common electrode (hereinafter referred to as the common voltage) will change due to the coupling phenomenon generated by theparasitic capacitance 105, causing the display panel to display these special images. There will be uneven brightness on the picture, and the special picture can be black frame, white frame and other grayscale frames. For example, when displaying a white picture with ablack frame 201 as shown in FIG. of the same brightness.

在显示面板中若要改善因寄生电容产生的耦合现象的影响，现有的作法需要借助制程的改变来降低寄生电容，但制程改变可能会影响显示面板的其他特性，且成本也较高。In order to improve the influence of the coupling phenomenon caused by the parasitic capacitance in the display panel, the existing method needs to change the process to reduce the parasitic capacitance, but the process change may affect other characteristics of the display panel, and the cost is also high.

发明内容Contents of the invention

有鉴于此，本发明的目的在提供一种用于液晶显示器的共用电压补偿装置、一种液晶显示器以及一种液晶显示器驱动方法，来降低显示面板中寄生电容耦合现象对液晶显示器的共用电压的影响。In view of this, the purpose of the present invention is to provide a common voltage compensation device for liquid crystal displays, a liquid crystal display and a driving method for liquid crystal displays, to reduce the effect of parasitic capacitive coupling phenomena in the display panel on the common voltage of the liquid crystal display. Influence.

为达成上述目的及其他目的，本发明提出一种液晶显示器，其用以接收并显示一影像信号，此影像信号包括一具有多个像素数据的水平线信号，且这些像素数据中相邻两像素数据极性相反。To achieve the above object and other objects, the present invention proposes a liquid crystal display, which is used to receive and display an image signal, the image signal includes a horizontal line signal with a plurality of pixel data, and the adjacent two pixel data of these pixel data opposite polarity.

此液晶显示器包括一时序控制器、一补偿电路以及一显示面板，而此时序控制器包括一查找表、一数据分析器以及一极性选择器。查找表内建多个共用电压补偿数值。数据分析器针对水平线信号的一灰阶分布进行分析，并根据分析结果对照查找表提供一数值控制信号，其中数值控制信号对应共用电压补偿数值的其中之一。极性选择器根据数据分析器的分析结果提供一极性控制信号。补偿电路根据数值控制信号及极性控制信号以提供一共用电压补偿信号。显示面板接收水平线信号及共用电压补偿信号，并借着共用电压补偿信号补偿共用电压以显示水平线信号。The liquid crystal display includes a timing controller, a compensation circuit and a display panel, and the timing controller includes a look-up table, a data analyzer and a polarity selector. Multiple common voltage compensation values are built into the lookup table. The data analyzer analyzes a grayscale distribution of the horizontal line signal, and provides a numerical control signal according to the analysis result against a lookup table, wherein the numerical control signal corresponds to one of the common voltage compensation values. The polarity selector provides a polarity control signal according to the analysis result of the data analyzer. The compensation circuit provides a common voltage compensation signal according to the numerical control signal and the polarity control signal. The display panel receives the horizontal line signal and the common voltage compensation signal, and uses the common voltage compensation signal to compensate the common voltage to display the horizontal line signal.

本发明另提出一种共用电压补偿装置，适用于一液晶显示器的显示面板，其是用以接收并显示一影像信号，其中影像信号包括一具有多个像素数据的水平线信号，且这些像素数据中相邻两像素数据极性相反。此共用电压补偿装置包括一查找表、一数据分析器、一极性选择器以及一补偿电路。在一实施例中，当数据分析器分析出该灰阶分布是水平线信号的奇数个像素数据中在一灰阶值范围内的个数与水平线信号的偶数个像素数据中在该灰阶值范围内的个数二者相差大于M个且大于N倍时，数据分析器借助数值控制信号使补偿电路对显示面板的共用电压进行补偿，其中M与N为正整数。而M及N可根据譬如显示面板的水平解析度或显示面板的大小来做调整。The present invention also proposes a common voltage compensation device, which is suitable for a display panel of a liquid crystal display, and is used to receive and display an image signal, wherein the image signal includes a horizontal line signal having a plurality of pixel data, and among these pixel data The data polarities of two adjacent pixels are opposite. The common voltage compensation device includes a look-up table, a data analyzer, a polarity selector and a compensation circuit. In one embodiment, when the data analyzer analyzes the grayscale distribution, the number of odd-numbered pixel data of the horizontal line signal within a grayscale value range is the same as the number of even-numbered pixel data of the horizontal line signal within the grayscale value range When the difference between the two numbers is more than M and more than N times, the data analyzer uses the numerical control signal to make the compensation circuit compensate the common voltage of the display panel, wherein M and N are positive integers. M and N can be adjusted according to, for example, the horizontal resolution of the display panel or the size of the display panel.

本发明又提出一种液晶显示器驱动方法，此液晶显示器驱动方法先接收一影像信号，其中影像信号包括一具有多个像素数据的水平线信号，且这些像素数据中相邻两像素数据极性相反画面。此液晶显示器驱动方法再针对水平线信号的灰阶分布进行分析，根据灰阶分布的分析结果判断是否须进行共用电压补偿，以及在需进行共用电压补偿时，决定补偿的电压极性以进行共用电压补偿。The present invention also proposes a liquid crystal display driving method. The liquid crystal display driving method first receives an image signal, wherein the image signal includes a horizontal line signal with a plurality of pixel data, and the polarity of two adjacent pixel data in the pixel data is opposite to the frame. . This liquid crystal display driving method then analyzes the gray scale distribution of the horizontal line signal, judges whether common voltage compensation is necessary based on the analysis result of the gray scale distribution, and determines the polarity of the compensated voltage to perform common voltage compensation when common voltage compensation is required. compensate.

正因为本发明可以在不需改变制程的条件下，借助前端数据分析器判断数据的灰阶分布后，再利用补偿电路来补偿因寄生电容所造成的耦合现象，进而改善此耦合现象对画面品质的影响。Just because the present invention can use the compensation circuit to compensate the coupling phenomenon caused by the parasitic capacitance after judging the gray scale distribution of the data by means of the front-end data analyzer without changing the manufacturing process, thereby improving the effect of the coupling phenomenon on the picture quality Impact.

为让本发明的上述和其他目的、特征和优点能更明显易懂，下文特举较佳实施例，并配合附图作详细说明如下。In order to make the above and other objects, features and advantages of the present invention more comprehensible, preferred embodiments are exemplified below and described in detail with accompanying drawings.

附图说明Description of drawings

图1为现有的液晶显示器的像素电路。FIG. 1 is a pixel circuit of an existing liquid crystal display.

图2为黑框两侧的辉度与其他区的差异示意图。FIG. 2 is a schematic diagram of the difference between the luminance on both sides of the black frame and other areas.

图3为依照本发明较佳实施例所示的液晶显示器的方块图。FIG. 3 is a block diagram of a liquid crystal display according to a preferred embodiment of the present invention.

图4在显示面板上显示一画面时该画面的像素数据的极性分布示意图。FIG. 4 is a schematic diagram of polarity distribution of pixel data of a frame when a frame is displayed on a display panel.

图5为图3所示液晶显示器中相关信号的时序图。FIG. 5 is a timing diagram of related signals in the liquid crystal display shown in FIG. 3 .

图6为依照本发明较佳实施例所示的液晶显示器驱动方法的流程图。FIG. 6 is a flow chart of a liquid crystal display driving method according to a preferred embodiment of the present invention.

具体实施方式Detailed ways

图3为依照本发明一较佳实施例所示的液晶显示器的方块图。请参照图3，液晶显示器300包括共用电压补偿装置301与显示面板307。其中，共用电压补偿装置301包括时序控制器303和补偿电路305，而显示面板307包括共用电极基板307a与阵列电路基板307b。共用电极基板307a接收一共用电压信号，阵列电路基板307b接收一影像信号，且两基板307a与307b之间的液晶分子受到共用电压信号与影像信号的电压差所驱动。FIG. 3 is a block diagram of a liquid crystal display according to a preferred embodiment of the present invention. Referring to FIG. 3 , theliquid crystal display 300 includes a commonvoltage compensation device 301 and adisplay panel 307 . Wherein, the commonvoltage compensation device 301 includes atiming controller 303 and acompensation circuit 305, and thedisplay panel 307 includes acommon electrode substrate 307a and anarray circuit substrate 307b. Thecommon electrode substrate 307a receives a common voltage signal, thearray circuit substrate 307b receives an image signal, and the liquid crystal molecules between the twosubstrates 307a and 307b are driven by the voltage difference between the common voltage signal and the image signal.

补偿电路305会依据时序控制器303输出的数值控制信号和极性控制信号，配合锁存脉冲(latch pulse)信号以提供一共用电压补偿信号到共用电极基板307a，其中锁存脉冲信号作为源极驱动器数据输出的控制信号，一般由时序控制器303提供。所以，共用电极基板307a除了接收共用电压信号外，还接收共用电压补偿信号以补偿共用电极基板307a上的共用电压受寄生电容的耦合现象而产生电压变化。Thecompensation circuit 305 will cooperate with the latch pulse (latch pulse) signal to provide a common voltage compensation signal to thecommon electrode substrate 307a according to the numerical control signal and the polarity control signal output by thetiming controller 303, wherein the latch pulse signal is used as the source The control signal of the driver data output is generally provided by thetiming controller 303 . Therefore, in addition to receiving the common voltage signal, thecommon electrode substrate 307a also receives the common voltage compensation signal to compensate for the voltage variation of the common voltage on thecommon electrode substrate 307a due to the coupling phenomenon of the parasitic capacitance.

在本实施例中，时序控制器303包括缓冲器309、数据分析器311、查找表313和极性选择器315。缓冲器309用以接收并暂存影像信号，其中影像信号由连续的画面所组成，每一画面包括多条水平线信号，每一条水平线信号具有多个像素数据，且这些像素数据中相邻两像素数据极性相反。数据分析器311接收缓冲器309输出的影像信号，并分别对影像信号的每一条水平线信号进行灰阶分布的分析。In this embodiment, thetiming controller 303 includes abuffer 309 , adata analyzer 311 , a lookup table 313 and apolarity selector 315 . Thebuffer 309 is used to receive and temporarily store the image signal, wherein the image signal is composed of continuous frames, each frame includes a plurality of horizontal line signals, each horizontal line signal has a plurality of pixel data, and two adjacent pixels of these pixel data The data polarity is reversed. Thedata analyzer 311 receives the image signal output from thebuffer 309 and analyzes the gray scale distribution of each horizontal line signal of the image signal.

另外，数据分析器311分别电性连接到查找表313、极性选择器315和补偿电路305。其中，数据分析器311会根据灰阶分布的分析结果与查找表313内建的多个共同电压补偿数值做比对，从查找表313内选择一共同电压补偿数值以输出相应的数值控制信号到补偿电路305。而数据分析器311的灰阶分布的分析结果也提供到极性选择器315做水平线信号极性的选择，再经由极性选择器315输出相应的极性控制信号到补偿电路305。In addition, thedata analyzer 311 is electrically connected to the look-up table 313 , thepolarity selector 315 and thecompensation circuit 305 respectively. Wherein, thedata analyzer 311 compares the analysis result of the gray scale distribution with a plurality of common voltage compensation values built in the lookup table 313, and selects a common voltage compensation value from the lookup table 313 to output a corresponding numerical control signal tocompensation circuit 305 . The analysis result of the gray scale distribution of thedata analyzer 311 is also provided to thepolarity selector 315 for selecting the polarity of the horizontal line signal, and then outputs a corresponding polarity control signal to thecompensation circuit 305 via thepolarity selector 315 .

因此，补偿电路305所提供的共用电压补偿信号的数值与极性分别由时序控制器303输出的数值控制信号与极性控制信号来决定，而其时序则是由锁存脉冲信号来决定。一般而言，共用电压补偿信号送出的时间在锁存脉冲信号的下降缘。Therefore, the value and polarity of the common voltage compensation signal provided by thecompensation circuit 305 are respectively determined by the value control signal and polarity control signal output by thetiming controller 303 , and its timing is determined by the latch pulse signal. Generally speaking, the common voltage compensation signal is sent out at the falling edge of the latch pulse signal.

众所皆知地，一般显示面板的驱动方式分为画面反转(frame inversion)、行反转(column inversion)、列反转(row inversion)及点反转(dot inversion)。借助改变驱动液晶分子的电压的极性，以防止液晶分子的特性变差造成画面品质变差。而本发明适用于采用譬如点反转或行反转驱动方式的液晶显示器。As we all know, the general display panel driving methods are divided into frame inversion, column inversion, row inversion and dot inversion. By changing the polarity of the voltage driving the liquid crystal molecules, it is possible to prevent the deterioration of the characteristics of the liquid crystal molecules and the deterioration of the picture quality. However, the present invention is applicable to liquid crystal displays using, for example, dot inversion or row inversion driving methods.

此外，一般显示面板的驱动方式也分为正常显白(normally white)以及正常显黑(normally black)。对正常显白的显示面板进行驱动时，施加于面板上的白信号与共用电压的电压差较小，而黑信号与共用电压的电压差较大，因此黑信号因为寄生电容的耦合现象会对共用电压造成较大的影响。反之，对正常显黑的显示面板进行驱动时，白信号会对共用电压造成较大的影响。下面将以正常显白并采点反转驱动方式的显示面板为例来描述本发明，凡本领域普通技术人员当可轻易将本发明的发明精神应用在正常显黑或行反转驱动方式的显示面板。In addition, the driving methods of general display panels are also divided into normally white and normally black. When driving a normally white display panel, the voltage difference between the white signal and the common voltage applied to the panel is small, while the voltage difference between the black signal and the common voltage is relatively large, so the black signal will be affected by the coupling phenomenon of parasitic capacitance The common voltage has a large influence. Conversely, when driving a normally black display panel, the white signal will have a greater impact on the common voltage. The present invention will be described below by taking a display panel normally displaying white and adopting a dot inversion driving method as an example, and those skilled in the art can easily apply the inventive spirit of the present invention to a display panel normally displaying black or using a line inversion driving method display panel.

图4为在显示面板上显示一画面时该画面的像素数据的极性分布示意图，该显示面板采用点反转驱动方式，其中「+」为正极性而「-」为负极性。请参照图4所示的显示面板，在显示面板上奇数条源极配线依序标示为401、403、405、…，偶数条源极配线依序标示为402、404、406、…，而栅极配线依序标示为41～46。其中，每一源极配线401～413和每一栅极配线41～6交叉处即配置一像素，此像素可以暂存并显示一像素数据。为方便说明，定义源极配线401和栅极配线41交叉处所配置的像素暂存并显示的像素数据为P(401，41)，源极配线402和栅极配线41交叉处所配置的像素暂存并显示的像素数据为P(402，41)，其它依此类推。4 is a schematic diagram of the polarity distribution of pixel data of a frame when a frame is displayed on the display panel. The display panel adopts a dot inversion driving method, wherein "+" is positive polarity and "-" is negative polarity. Please refer to the display panel shown in FIG. 4 , the odd-numbered source wirings are marked as 401, 403, 405, ... on the display panel, and the even-numbered source wirings are marked as 402, 404, 406, ..., The gate wirings are marked as 41-46 in sequence. Wherein, a pixel is arranged at the intersection of each source wiring 401-413 and each gate wiring 41-6, and this pixel can temporarily store and display a pixel data. For the convenience of description, define the pixel data temporarily stored and displayed at the intersection of thesource wiring 401 and thegate wiring 41 as P(401, 41), and the intersection of thesource wiring 402 and thegate wiring 41 is arranged at The temporarily stored and displayed pixel data of the pixels is P(402, 41), and so on.

举例来说，当以脉冲信号致动栅极配线41时，透过源极配线401～413将一条水平线信号送到像素中，其中这条水平线信号包括像素数据P(401，41)、P(402，41)、P(403，41)、…、P(413，41)，且这些像素数据P(401，41)～P(413，41)相邻两像素数据极性相反。接着，当栅极配线42被致动时，将另一条包括像素数据P(401，42)～P(413，42)的水平线信号送到像素中，其中像素数据P(401，42)～P(413，42)相邻两像素数据极性相反，且像素数据P(401，42)～P(413，42)与相应位置的像素数据P(401，41)～P(413，41)相邻两像素数据极性也相反。因此，逐条致动栅极配线41～46并将相应的像素数据送到像素中，以产生如图4所示的像素数据的极性分布。For example, when thegate wiring 41 is activated with a pulse signal, a horizontal line signal is sent to the pixel through the source wiring 401-413, wherein the horizontal line signal includes pixel data P(401, 41), P(402, 41), P(403, 41), . Next, when thegate wiring 42 is activated, another horizontal line signal including pixel data P(401,42)~P(413,42) is sent to the pixel, wherein the pixel data P(401,42)~ P(413,42) adjacent two pixel data polarities are opposite, and the pixel data P(401,42)~P(413,42) and the corresponding pixel data P(401,41)~P(413,41) The data polarities of two adjacent pixels are also opposite. Therefore, the gate wires 41-46 are activated one by one and the corresponding pixel data is sent to the pixels, so as to generate the polarity distribution of the pixel data as shown in FIG. 4 .

此外，若图4所示为目前画面的像素数据的极性分布，则下一画面的像素数据的极性分布须与目前画面相反，即「+」变为「-」而「-」变为「+」，其中每一画面的极性分布的反转由譬如图3的极性选择器315所提供的极性POL决定。例如，当极性POL为正极性时，像素数据P(401，41)为正极性而像素数据P(402，41)为负极性；反之，若极性POL为负极性时，像素数据P(401，41)为负极性而像素数据P(402，41)为正极性。In addition, if the polarity distribution of the pixel data of the current frame is shown in Figure 4, the polarity distribution of the pixel data of the next frame must be opposite to that of the current frame, that is, "+" becomes "-" and "-" becomes "+", where the inversion of the polarity distribution of each frame is determined by, for example, the polarity POL provided by thepolarity selector 315 of FIG. 3 . For example, when the polarity POL is positive, the pixel data P(401, 41) is positive and the pixel data P(402, 41) is negative; otherwise, if the polarity POL is negative, the pixel data P( 401, 41) is negative polarity and the pixel data P(402, 41) is positive polarity.

图5为图3所示液晶显示器300中相关信号的时序图。请同时参照图3、图4与图5，共用电压补偿装置301提供一判断机制来决定是否对共用电压进行补偿。此判断机制是由数据分析器311对影像信号中的每一水平线信号的奇数个像素数据中在一灰阶值范围内的个数与水平线信号的偶数个像素数据中在该灰阶值范围内的个数进行分析。其中，若以栅极配线41被致动时送入的水平线信号为例，此水平线信号包括奇数个像素数据P(401，41)、P(403，41)、…、P(413，41)，以及偶数个像素数据P(402，41)、P(404，41)、…、P(412，41)。FIG. 5 is a timing diagram of related signals in theliquid crystal display 300 shown in FIG. 3 . Please refer to FIG. 3 , FIG. 4 and FIG. 5 at the same time, the commonvoltage compensation device 301 provides a judging mechanism to determine whether to compensate the common voltage. The judging mechanism is that thedata analyzer 311 compares the number of odd-numbered pixel data of each horizontal line signal in the image signal within a grayscale value range and the number of even-numbered pixel data of the horizontal line signal within the grayscale value range. number are analyzed. Wherein, if the horizontal line signal sent in when thegate wiring 41 is activated is taken as an example, the horizontal line signal includes an odd number of pixel data P(401, 41), P(403, 41), ..., P(413, 41 ), and even pixel data P(402, 41), P(404, 41), ..., P(412, 41).

再者，以8位元灰阶(256色阶)为例，且其灰阶值从0(全黑)到255(全白)。Furthermore, take 8-bit grayscale (256 color levels) as an example, and its grayscale value ranges from 0 (full black) to 255 (full white).

由于采用正常显白的显示面板，黑信号对共用电压的影响较大，因此只统计奇数个(或偶数个)像素数据中灰阶值落在上述灰阶值范围内的个数。在此实施例中，此灰阶值范围譬如为0～50。Since a normally white display panel is used, the black signal has a greater impact on the common voltage, so only the number of odd (or even) pixel data whose gray scale values fall within the above gray scale value range is counted. In this embodiment, the range of the grayscale value is, for example, 0-50.

当奇数个像素数据中在灰阶值范围内的个数与水平线信号的偶数个像素数据中在该灰阶值范围内的个数二者相等时，由于奇数个与偶数个像素数据极性相反而对共用电压的影响互相抵消，因此不需要对共用电压进行补偿。When the number of odd-numbered pixel data within the grayscale value range is equal to the number of even-numbered pixel data within the grayscale value range of the horizontal line signal, since the polarity of the odd-numbered and even-numbered pixel data is opposite The effects on the common voltage cancel each other out, so there is no need to compensate the common voltage.

当奇数个像素数据中在灰阶值范围内的个数与水平线信号的偶数个像素数据中在该灰阶值范围内的个数二者相差大于M个且大于N倍时，整条水平数据线会对共用电压造成影响。例如，若奇数个像素数据为负极性而偶数个像素数据为正极性，则当极性POL为正极性501且在锁存脉冲信号的下降缘503时，产生降低的共用电压504，接着，当极性POL为负极性502且在锁存脉冲信号的下降缘503时，产生升高的共用电压505。因此补偿电路305根据数据分析器311输出的数值控制信号决定输出的共用电压补偿信号的大小，以及根据极性选择器315输出的极性控制信号决定输出的共用电压补偿信号的极性，以产生适当的共用电压补偿信号对共用电压进行补偿。When the difference between the number of odd-numbered pixel data within the grayscale value range and the number of even-numbered pixel data within the grayscale value range of the horizontal line signal is greater than M and greater than N times, the entire horizontal data Lines will affect the common voltage. For example, if the odd number of pixel data is negative polarity and the even number of pixel data is positive polarity, then when the polarity POL ispositive polarity 501 and at the fallingedge 503 of the latch pulse signal, a reducedcommon voltage 504 is generated, and then, when The polarity POL is negative 502 and on the fallingedge 503 of the latch pulse signal, a risingcommon voltage 505 is generated. Therefore, thecompensation circuit 305 determines the magnitude of the output common voltage compensation signal according to the numerical control signal output by thedata analyzer 311, and determines the polarity of the output common voltage compensation signal according to the polarity control signal output by thepolarity selector 315, to generate An appropriate common voltage compensation signal compensates the common voltage.

再举例来说，如果奇数个像素数据中在灰阶值范围内的个数为1000而偶数个像素数据中在灰阶值范围内的个数为600，则二者相差400(＝1000-600)个且相差1.67(＝1000/600)倍。假使根据譬如显示面板的水平解析度或显示面板的大小将M与N分别调整为300与2，则上述相差400个(＞M个)且相差1.67倍(＜N倍)的情形将不需要进行共用电压补偿。For another example, if the number of odd-numbered pixel data within the grayscale value range is 1000 and the number of even-numbered pixel data within the grayscale value range is 600, the difference between the two is 400 (=1000-600 ) with a difference of 1.67 (=1000/600) times. If M and N are adjusted to 300 and 2 respectively according to, for example, the horizontal resolution of the display panel or the size of the display panel, then the above-mentioned situation with a difference of 400 (>M) and a difference of 1.67 times (<N times) will not need to be performed. common voltage compensation.

图6为依照本发明较佳实施例所示的液晶显示器驱动方法的流程图。请同时参照图3与图6，首先，在步骤S601，液晶显示器300接收一影像信号，其中影像信号包括一具有多个像素数据的水平线信号，且这些像素数据中相邻两像素数据极性相反。在步骤S603，数据分析器311针对影像信号的一水平线信号的灰阶分布进行分析。接着，在步骤S605根据灰阶分布的分析结果判断是否需要进行共用电压补偿。若需要进行共用电压补偿，则在步骤S607决定所需补偿的电压极性，在步骤S609由补偿电路305产生具有适当大小与极性的共用电压补偿信号，以及在步骤S611将共用电压补偿信号送至显示面板307。FIG. 6 is a flow chart of a liquid crystal display driving method according to a preferred embodiment of the present invention. Please refer to FIG. 3 and FIG. 6 at the same time. First, in step S601, theliquid crystal display 300 receives an image signal, wherein the image signal includes a horizontal line signal having a plurality of pixel data, and the polarities of two adjacent pixel data in these pixel data are opposite . In step S603 , thedata analyzer 311 analyzes the grayscale distribution of a horizontal line signal of the image signal. Next, in step S605, it is determined whether the common voltage compensation needs to be performed according to the analysis result of the gray scale distribution. If common voltage compensation is required, the polarity of the voltage to be compensated is determined in step S607, thecompensation circuit 305 generates a common voltage compensation signal with appropriate magnitude and polarity in step S609, and the common voltage compensation signal is sent to step S611 to thedisplay panel 307.

综上所述，本发明因采用一种共用电压补偿装置针对接收的影像信号的每一水平线信号进行灰阶分布的分析，可以在不修改制程下，补偿显示面板的共用电压受到寄生电容耦合现象的影响，进而改善画面品质。To sum up, the present invention uses a common voltage compensation device to analyze the gray scale distribution of each horizontal line signal of the received image signal, and can compensate the parasitic capacitive coupling phenomenon of the common voltage of the display panel without modifying the manufacturing process. to improve the picture quality.

虽然本发明已以较佳实施例揭示如上，然其并非用以限定本发明，任何本领域普通技术人员在不脱离本发明的精神和范围内，当可作些许更动与润饰，因此本发明的保护范围当以权利要求所界定的为准。Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art may make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, the present invention The scope of protection should be defined by the claims.