200939195 九、發明說明： 【發明所屬之技術領域】 本發明是有關於一種液晶顯示器及其驅動方法，且特 別是有關於一種可以提供穩定的共同電壓之液晶顯示器 及其驅動方法。 【先前技術】 請參照第1圖，其繪示乃傳統液晶顯示器之一例之示 ❹ 意圖。液晶顯示器100包括一液晶面板110、一掃描驅動 單元120、一資料驅動單元130以及一共同電壓產生電路 140。液晶面板110包括多個晝素（未繪示於圖），掃描驅動 單元120用以致能多個畫素，資料驅動單元130用以驅動 多個晝素。 共同電壓產生電路140係利用一電阻分壓電路142產 生共同電聲Vcom，並經由一緩衝器144將共同電壓Vcom 輸出至液晶面板110之多個畫素。其中，可藉由可變電阻 ❿ R2調整共同電壓Vcom之大小。液晶面板110内之多個晝 素係依據一極性控制訊號而使得各自的晝素電壓相對於 共同電壓Vcom為正負相間之交流訊號，以避免晝素内之 液晶分子因正負極性電荷不對稱而造成永久極化的現 象，導致液晶顯示器100產生晝面僵直（Image Sticking)。 此外，共同電壓Vcom亦可以數位的方式產生。請參 照第2圖，其繪示乃傳統液晶顯示器之另一例之示意圖。 液晶顯示器200包括一液晶面板210、一掃描驅動單元 6 200939195 220、-資料驅動單元23G以及—共同電壓產 共同電壓產生電路240包括—電子式可清除程％路24〇。 憶體(EEPROM)242、一數位晶片（1〇2料^及^化唯讀記 246。數位晶片244依據預先儲存於電子式可主，衝器 唯讀記憶體242之資料產生共同電壓Vc〇m，二二t式化 器246將共同電壓Vc〇m輸出至液晶面板21〇^衝 ❹ 然而，隨著液晶面板的尺寸越來越大，因應液曰一素 負載的增加’資料驅動單元需要更大的驅動能：方：：板 多個晝素’但同時也會伴隨產生晝素電壓耦合(c〇upi^量= 大的問題。過大的晝素電壓耦合量會使得參考電壓 產生明顯的變動，如此一來，將使得液晶面板内之多個畫 素接收到不穩定的參考電壓Vcom，導致液晶面板光學^ 性變差並產生色偏，故液晶顯示器無法顯示正確的畫面。 【發明内容] 本發明係有關於一種液晶顯示器及其驅動方法，依據 極性控制訊號及畫素資料，以主動地對共同電壓進行補 償’以提供穩定的共同電壓給液晶面板，進而改善液晶面 板之光學特性。 根據本發明之第一方面，提出一種液晶顯示器，包括 一液晶面板、一掃描驅動單元、一資料驅動單元、一共同 電壓產生電路以及一時脈控制裝置。液晶面板至少具有一 列晝素。掃插驅動單元用以致能此列畫素。資料驅動單元 7 200939195 用以驅動此列畫素。共同電壓產生電路耦接至液晶面板。 時脈控制裝置用以輸出一極性控制訊號及分別對應至此 些畫素之多個晝素資料至資料驅動單元，使得資料驅動單 元依據極性控制訊號及晝素資料輸出多個晝素電壓以分 別驅動相對應之晝素。並且時脈控制裝置控制共同電壓產 生電路產生相對應於極性控制訊號及晝素資料之一共同 電壓。 根據本發明之第二方面，提出一種液晶顯示器驅動方 ❹ 法，包括，依據一極性控制訊號及分別對應至一列畫素之 多個畫素資料產生多個畫素電壓。產生相對應於極性控制 訊號及多個畫素資料之一共同電壓。依據多個畫素電壓與 共同電壓以驅動此列畫素。 為讓本發明之上述内容能更明顯易懂，下文特舉一較 佳實施例，並配合所附圖式，作詳細說明如下： 【實施方式】 ❹ 本發明提供一種液晶顯示器及其驅動方法，依據畫素 資料對共同電壓進行補償，以改善液晶面板之光學特性。 請參照第3圖，其繪示乃依照本發明較佳實施例之液 晶顯示器之示意圖。液晶顯示器300包括一液晶面板310、 一掃描驅動單元320、一資料驅動單元330、一共同電壓 產生電路340以及一時脈控制裝置350。液晶面板310包 括多列畫素，掃描驅動單元320用以致能此多列晝素，資 料驅動單元330用以驅動此多列晝素。共同電壓產生電路 8 200939195 340耦接至液晶面板31〇。 時脈控制裝置350包括時脈控制單元352及資料分析 單元355。時脈控制單元352從一前級電路（未繪示於圖） 接收對應至液晶面板310之一列晝素之多個畫素資料 Data，並將此些畫素資料Data輸出至資料驅動單元33〇。 此外，時脈控制單元352亦輸出一掃瞒控制訊號STV以护： 制掃描驅動單元320之時序。 時脈控制單元352產生一極性控制訊鍊p〇L及一時 ❾序控制訊號TP1 ’並將極性控制訊號p〇L及時序控制訊號 TP1輸出至資料驅動單元330。資料驅動單元33〇於時序 控制訊號TP1之一脈衝之上升緣(rising edge)接收多個畫 素資料Data。之後，資料驅動單元330依據極性控制訊號 POL及多個畫素資料Data’於時序控制訊號TP1之同一脈 衝之下降緣（falling edge)輸出相對應於多個畫素資料Data 之多個畫素電壓以分別驅動相對應的晝素。 效舉一列畫素包括六個畫素，共同電壓Vcom為8伏 特’且液明面板310之驅動方式為點反轉（d〇t inverSi〇n) 驅動為例做說明’但並不限於此。若對應至一列晝素之六 個畫素資料依序為D1〜D6’則資料驅動單元330依據極性 控制訊號POL及晝素資料D1-D6，輸出以共同電壓vc〇m 為參考電壓之六個晝素電壓，以分別驅動六個畫素。此六 個晝素電壓例如為14伏特、7伏特、12伏特、6伏特、13 伏特及5伏特。 如此一來，相對應於共同電壓Vcom為8伏特而言， 9 200939195 則六個畫素電壓所產生之畫素電壓_人旦& (14-8+7·8+12-8+6_8+13-8+5 吟 晝素電壓搞合量 會扯動共同電壓v_，例如共同電壓ν_由8伏特上 升2伏特為10伏特。亦即’六個晝素資料di〜d6依據極 性控制訊號POL進行分析處理的結果 (m-D2+D3_D4+D5损）會對應至晝°素電隸合量9伏特， 並對共同電壓Vcom產生2伏特的影響。其中，一般而言， 多個畫素資料Data依據極性㈣㈣號pQL進行分析處理 ❹的結果及對共同電壓Vcom產生的影響，兩者之間的關係 可以經由多次的實驗而得到’並被記錄於一查閱表中。 時脈控制裝置350内之資料分析單元355係用以對極 性控制訊號POL及多個畫素資料⑽進行分析，使得時 脈控制裝置350依據分析的結果控制共同電壓產生電路 34〇產生相對應於極性控制訊號p〇L及畫素資料Data之 I共同電壓Vcom。例如，相對應於會產生畫素電壓耦合 ❹=9伏特之極性控制訊號p〇L及畫素資料di〜d6，資料 分析單元355依據分析的結果從查閱表中輸出一數位訊 號以使得共同電壓產生電路340產生共同電壓vc〇m， J如為6伏特。如此一來，雖然9伏特之晝素電壓叙合量 會扯動共同電壓Vcom上升2伏特’但共同電壓vcom可 以穩定地維持於8伏特，不會導致液晶面板光學特性變差 並產生色偏。其中，查閱表可以儲存於一電子式可清除程 式化唯讀記憶體(EEPROM)。 請參照第4圖，其繪示乃依照本發明較佳實施例之共 200939195 同電壓產生電路之方塊圖。共同電壓產生電路34〇包括__ 數位類比轉換器342及一缓衝器344。數位類比轉換器342 用以將數位訊號轉換為相對應於極性控制訊號p〇L及圭 素資料Data之共同電壓Vcom°緩衝器344耦接至數位&類 比轉換器342。當時序控制訊號TP1之一脈衝為下降緣、 (falling edge)時，資料驅動單元330輸出多個晝素電壓至 液晶面板310之此列晝素，同時共同電壓產生電路亦 將共同電壓Vcom輸出至此列晝素。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display and a driving method thereof, and in particular to a liquid crystal display which can provide a stable common voltage and a driving method thereof. [Prior Art] Referring to Fig. 1, there is shown an illustration of an example of a conventional liquid crystal display. The liquid crystal display 100 includes a liquid crystal panel 110, a scan driving unit 120, a data driving unit 130, and a common voltage generating circuit 140. The liquid crystal panel 110 includes a plurality of pixels (not shown), the scan driving unit 120 is configured to enable a plurality of pixels, and the data driving unit 130 is configured to drive a plurality of pixels. The common voltage generating circuit 140 generates a common electroacoustic Vcom by using a resistor dividing circuit 142, and outputs the common voltage Vcom to a plurality of pixels of the liquid crystal panel 110 via a buffer 144. Among them, the magnitude of the common voltage Vcom can be adjusted by the variable resistor ❿ R2. The plurality of halogens in the liquid crystal panel 110 are based on a polarity control signal such that the respective pixel voltages are positive and negative alternating current signals with respect to the common voltage Vcom, so as to prevent liquid crystal molecules in the halogen from being asymmetric due to positive and negative polarity charges. The phenomenon of permanent polarization causes the liquid crystal display 100 to produce Image Sticking. In addition, the common voltage Vcom can also be generated in a digital manner. Please refer to Fig. 2, which is a schematic view showing another example of a conventional liquid crystal display. The liquid crystal display 200 includes a liquid crystal panel 210, a scan driving unit 6 200939195 220, a data driving unit 23G, and a common voltage generating common voltage generating circuit 240 including an electronic clearable path %24. Recalling body (EEPROM) 242, a digital chip (1〇2 material ^ and ^化读读记246). The digital chip 244 generates a common voltage Vc according to data stored in advance in the electronically configurable, punch-only memory 242. m, the two-t-type chemist 246 outputs the common voltage Vc 〇 m to the liquid crystal panel 21 ❹ ❹ ❹ However, as the size of the liquid crystal panel becomes larger and larger, the load of the liquid-based one is increased. Larger driving energy: square:: multiple slabs of the board' but at the same time will also produce a voltage coupling of the 昼 ( (c〇upi^ = large problem. Excessive voltage coupling of the pixel will make the reference voltage significantly The change, as a result, will cause the plurality of pixels in the liquid crystal panel to receive the unstable reference voltage Vcom, resulting in poor optical quality of the liquid crystal panel and color shift, so that the liquid crystal display cannot display the correct picture. The present invention relates to a liquid crystal display and a driving method thereof, which actively compensates a common voltage according to a polarity control signal and pixel data to provide a stable common voltage to the liquid crystal panel, thereby improving the liquid. According to a first aspect of the present invention, a liquid crystal display includes a liquid crystal panel, a scan driving unit, a data driving unit, a common voltage generating circuit, and a clock control device. The liquid crystal panel has at least one column. The scan driving unit is configured to enable the column pixels. The data driving unit 7 200939195 is used to drive the column pixels. The common voltage generating circuit is coupled to the liquid crystal panel. The clock control device is configured to output a polarity control signal and respectively Corresponding to the plurality of pixel data of the pixels to the data driving unit, the data driving unit outputs the plurality of pixel voltages according to the polarity control signal and the halogen data to respectively drive the corresponding pixels, and the clock control device controls the common The voltage generating circuit generates a common voltage corresponding to one of the polarity control signal and the pixel data. According to a second aspect of the present invention, a liquid crystal display driving method is provided, comprising: controlling signals according to a polarity and respectively corresponding to a column of pixels Multiple pixel data to generate multiple pixel voltages The voltage should be common to one of the polarity control signal and the plurality of pixel data. The plurality of pixel voltages and the common voltage are used to drive the column of pixels. To make the above content of the present invention more obvious, the following is a special The preferred embodiment and the accompanying drawings are described in detail as follows: [Embodiment] The present invention provides a liquid crystal display and a driving method thereof, which compensate for a common voltage according to pixel data to improve the optical characteristics of the liquid crystal panel. Please refer to FIG. 3, which is a schematic diagram of a liquid crystal display according to a preferred embodiment of the present invention. The liquid crystal display 300 includes a liquid crystal panel 310, a scan driving unit 320, a data driving unit 330, and a common voltage generating circuit 340. And a clock control device 350. The liquid crystal panel 310 includes a plurality of columns of pixels, and the scan driving unit 320 is configured to enable the plurality of pixels. The data driving unit 330 is configured to drive the plurality of pixels. The common voltage generating circuit 8 200939195 340 is coupled to the liquid crystal panel 31A. The clock control device 350 includes a clock control unit 352 and a data analysis unit 355. The clock control unit 352 receives a plurality of pixel data Data corresponding to one of the pixels of the liquid crystal panel 310 from a pre-stage circuit (not shown), and outputs the pixel data Data to the data driving unit 33. . In addition, the clock control unit 352 also outputs a broom control signal STV to protect the timing of the scan driving unit 320. The clock control unit 352 generates a polarity control chain p〇L and a timing control signal TP1' and outputs the polarity control signal p〇L and the timing control signal TP1 to the data driving unit 330. The data driving unit 33 receives a plurality of pixel data Data at a rising edge of one of the timing control signals TP1. Thereafter, the data driving unit 330 outputs a plurality of pixel voltages corresponding to the plurality of pixel data Data according to the falling edge of the same pulse of the timing control signal TP1 according to the polarity control signal POL and the plurality of pixel data Data' To drive the corresponding pixels separately. The effect of a column of pixels includes six pixels, the common voltage Vcom is 8 volts', and the driving mode of the liquid crystal panel 310 is a dot inversion (d〇t inverSi〇n) driving as an example for description, but is not limited thereto. If the six pixel data corresponding to one column of pixels are sequentially D1 to D6', the data driving unit 330 outputs six signals with the common voltage vc〇m as the reference voltage according to the polarity control signal POL and the halogen data D1-D6. The pixel voltage is used to drive six pixels separately. The six pixel voltages are, for example, 14 volts, 7 volts, 12 volts, 6 volts, 13 volts, and 5 volts. In this way, corresponding to the common voltage Vcom is 8 volts, 9 200939195 is the pixel voltage generated by the six pixel voltages_人旦& (14-8+7·8+12-8+6_8+ 13-8+5 The voltage of the voltage will pull the common voltage v_, for example, the common voltage ν_ is increased by 8 volts and 2 volts is 10 volts. That is, the 'six elementary data di~d6 according to the polarity control signal POL The result of the analysis (m-D2+D3_D4+D5 loss) corresponds to 9 volts of 昼 素 电 , , , , , , , , , , , , , 。 。 。 。 。 共同 共同 。 。 共同 共同 共同 共同 共同 共同 共同 共同 共同 共同 共同 共同 共同 共同 共同 共同 共同 共同 共同Data is analyzed according to the polarity (4) (4) pQL and the effect on the common voltage Vcom. The relationship between the two can be obtained through multiple experiments and recorded in a look-up table. The clock control device 350 The data analysis unit 355 is configured to analyze the polarity control signal POL and the plurality of pixel data (10), so that the clock control device 350 controls the common voltage generation circuit 34 according to the analysis result to generate a polarity control signal p〇. L and pixel data Data I common voltage Vcom. For example, corresponding to the polarity control signal p〇L and the pixel data di~d6 which generate the pixel voltage coupling ❹=9 volts, the data analysis unit 355 outputs a digital signal from the look-up table according to the analysis result to make the common voltage The generating circuit 340 generates a common voltage vc 〇 m, J is 6 volts. Thus, although the 9 volt elementary voltage summation will pull the common voltage Vcom up by 2 volts 'but the common voltage vcom can be stably maintained at 8 Volts will not cause the optical characteristics of the LCD panel to deteriorate and produce color shift. The look-up table can be stored in an electronically erasable stylized read-only memory (EEPROM). Please refer to Figure 4, which is shown in accordance with this text. A block diagram of the same voltage generating circuit of the preferred embodiment of the invention. The common voltage generating circuit 34 includes a __digital analog converter 342 and a buffer 344. The digital analog converter 342 is used to convert the digital signal into a phase. The common voltage Vcom° buffer 344 corresponding to the polarity control signal p〇L and the data of the data is coupled to the digital & analog converter 342. When one of the timing control signals TP1 is a falling edge At the (falling edge), the data driving unit 330 outputs a plurality of pixel voltages to the pixels of the liquid crystal panel 310, and the common voltage generating circuit also outputs the common voltage Vcom to the pixels.
此外，時脈控制裝置350内之資料分析單元355可以 由-算術邏輯單元(ALU)實現，此算術邏輯單元依據極性 控制讯號POL對多個畫素資料Data進行運算，並將運算 的結果輸出至共同電壓產生電路34〇。數位類比轉換器 依據查閱表將算術邏輯單元運算的結果轉換為相對應於 極性控制訊號POL&多個晝素資料Data之共同電壓、 Vcom 〇其中’查閱表可以儲存於數位類比轉換器μ 器344將共同電壓ν_出至液晶面板31〇之 此列畫素。 本發明亦揭露-種液晶顯示器驅動方法，請參 示乃依照本發明較佳實施例之液晶顯示器驅動方 。其中*於步驟5〇0中，依據一極性控制訊號 愿此外〜至列旦素之多個畫素資料產生多個畫素電 於步驟510中，產生相對應於極性控制訊號及 料之—共同電壓。之後，於步驟52G中，根據 多個畫素電壓盥同雷厭ιν 聖…、Π電壓μ驅動此列畫素。上述之液晶顯 200939195 示器驅動方法，其原理係已詳述於液晶顯示器300中，故 於此不再重述。 本發明上述實施例所揭露之液晶顯示器及其驅動方 法，係利用時脈控制器依據極性控制訊號對晝素資料進行 分析運算，並依據分析運算的結果控制共同電壓產生電路 產生相對應之共同電壓，主動地對共同電壓進行補償，以 提供穩定的共同電壓給液晶面板，進而改善液晶面板之光 學特性。 ❹ 綜上所述，雖然本發明已以一較佳實施例揭露如上， 然其並非用以限定本發明。本發明所屬技術領域中具有通 常知識者，在不脫離本發明之精神和範圍内，當可作各種 之更動與潤飾。因此，本發明之保護範圍當視後附之申請 專利範圍所界定者為準。In addition, the data analysis unit 355 in the clock control device 350 can be implemented by an arithmetic logic unit (ALU) that operates on a plurality of pixel data Data according to the polarity control signal POL and outputs the result of the operation. To the common voltage generating circuit 34A. The digital analog converter converts the result of the arithmetic logic unit operation into a common voltage corresponding to the polarity control signal POL& multiple pixel data Data according to the look-up table, Vcom 〇 where the ' lookup table can be stored in the digital analog converter μ 344 The common voltage ν_ is output to the column pixels of the liquid crystal panel 31. The present invention also discloses a liquid crystal display driving method. Please refer to the liquid crystal display driving method in accordance with a preferred embodiment of the present invention. Wherein, in step 5〇0, according to a polarity control signal, a plurality of pixel data of the plurality of pixels are generated to generate a plurality of pixels in step 510 to generate a corresponding control signal corresponding to the polarity control signal. Voltage. Then, in step 52G, the column pixels are driven according to the plurality of pixel voltages, the 厌 ι 圣 Π, and the Π voltage μ. The above-mentioned liquid crystal display 200939195 display driving method has been described in detail in the liquid crystal display 300, and therefore will not be repeated here. The liquid crystal display and the driving method thereof disclosed in the above embodiments of the present invention use the clock controller to analyze and calculate the halogen data according to the polarity control signal, and control the common voltage generating circuit to generate a corresponding common voltage according to the result of the analysis operation. Actively compensating for the common voltage to provide a stable common voltage to the liquid crystal panel, thereby improving the optical characteristics of the liquid crystal panel. In the above, the present invention has been disclosed in a preferred embodiment, and is not intended to limit the present invention. It will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention. Therefore, the scope of the invention is defined by the scope of the appended claims.
12 200939195 【圖式簡單說明】 第1圖繪示傳統液晶顯示器之一例之示意圖。 第2圖繪示傳統液晶顯示器之另一例之示意圖。 第3圖繪示依照本發明較佳實施例之液晶顯示器之 示意圖。 第4圖繪示依照本發明較佳實施例之共同電壓產生 電路之方塊圖。 第5圖繪示依照本發明較佳實施例之液晶顯示器驅 © 動方法之流程圖。 【主要元件符號說明】 100、200、300 :液晶顯示器 110、210、310 :液晶面板 120、220、320 :掃描驅動單元 130、230、330 :資料驅動單元 140、240、340 :共同電壓產生電路 © 142 :電阻分壓電路 144、246、344 :緩衝器 242:電子式可清除程式化唯讀記憶體 244 :數位晶片 342 :數位類比轉換器 350 :時脈控制裝置 352 :時脈控制單元 355 :資料分析單元 1312 200939195 [Simple description of the drawing] Fig. 1 is a schematic view showing an example of a conventional liquid crystal display. FIG. 2 is a schematic view showing another example of a conventional liquid crystal display. Figure 3 is a schematic view of a liquid crystal display in accordance with a preferred embodiment of the present invention. Figure 4 is a block diagram of a common voltage generating circuit in accordance with a preferred embodiment of the present invention. FIG. 5 is a flow chart showing a method for driving a liquid crystal display according to a preferred embodiment of the present invention. [Main component symbol description] 100, 200, 300: liquid crystal display 110, 210, 310: liquid crystal panel 120, 220, 320: scan driving unit 130, 230, 330: data driving unit 140, 240, 340: common voltage generating circuit © 142: Resistor divider circuit 144, 246, 344: Buffer 242: electronically erasable stylized read-only memory 244: digital chip 342: digital analog converter 350: clock control device 352: clock control unit 355: data analysis unit 13