1361413 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的驅動系統與方法，特 別是有關於一種光學補償彎曲（Optically Compensated Bend ; OCB)液晶顯示器的驅動系統與方法。 【先前技術】 隨著科技的發展及生活水準的提高，人們對於顯示器的 要求也越來越高，由於液晶顯示器具有輕、薄、短、小以及 低耗能的優點，使得原本居於主流地位的陰極射線管（CRT) 顯示器逐漸地被液晶顯示器所取代。一般來說，目前的液晶 顯示器大多屬於扭曲向列型（Twisted Nematic ;TN)類型。 TN類型的液晶顯示器具有高影像對比值和容易製造等 優點，但是由於其反應速度較慢且可視角狹窄，因此其他類 型的液晶顯示器陸續被開發出來，以改進TN類型液晶顯示 器的缺點，其中光學補償彎曲（OCB)液晶顯示器反應速度 快，是相當重要的一種液晶顯示器。然而，OCB液晶顯示器 在開始工作之前，需先於初始轉換階段中，將液晶分子從展 開（splay)狀態轉換至彎曲（bend)狀態，才能於後續之階段中 i常地工作。但是光學補償彎曲液晶顯示器需要數秒鐘的時 間才能轉換到彎曲狀態，亦即，當一光學補償彎曲液晶顯示 器開啟後，藉由提供一短週期的高電壓方可使液晶分子達到 彎曲狀態，而開始正常顯示影像。 習知技藝係施加直流電壓於OCB液晶顯示器的共通電 5 極和貝料電極，來使液晶分子獲得能量，並從展開狀態轉換 至彎曲狀態。然而，使用直流電壓通常會導致液晶分子發生 極化的現象，而且這種方式所需之轉換時間通常為數秒，因 而對使用者造成相當大的不便。 【發明内容】 ^因此，本發明的目的就是在提供一種液晶顯示器的驅動 系統與方法，藉以減少初始轉換階段中所耗費的時間。 基板之間 掃描信號 影像信號 根據本發明之較佳實施例，液晶顯示器的驅動系統至少 包括：第一基板，包含資料電極；第二基板，包含共通電 極；液晶層，包含複數個液晶分子，係位於第一基板與第二 係用以輸出 係用以輪出 閘極驅動器，電性連接於第一基板， 源極驅動器，電性連接於第一基板， 衫憾號；以及電壓選擇裝置，根據電壓選擇訊號來選擇輪 出第一共電極電壓或第二共電極電壓至共通電極，其中電壓 選擇訊號係用以選擇初始轉換階段或正常顯示階段； 又，在上述之液晶顯示器的驅動系統中，第一共電極電 屡為交流訊號，係包含第-共電極„峰值與第—共電極電 Μ谷值。 又，在上述之液晶顯示器的驅動系統中，第一共電極電 廢峰值係實質介於20V與25V之間，而第一共電極電壓谷值 係實質介於-7V與-12V之間。 又，在上述之液晶顯示器的驅動系統中，第—共電極電BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a driving system and method for a liquid crystal display, and more particularly to a driving system and method for an optically compensated bend (OCB) liquid crystal display. [Prior Art] With the development of technology and the improvement of living standards, people have higher and higher requirements for displays. Due to the advantages of light, thin, short, small and low energy consumption, liquid crystal displays have been in the mainstream. Cathode ray tube (CRT) displays are gradually being replaced by liquid crystal displays. In general, current liquid crystal displays are mostly of the Twisted Nematic (TN) type. TN type liquid crystal displays have the advantages of high image contrast value and easy manufacture, but due to their slow reaction speed and narrow viewing angle, other types of liquid crystal displays have been developed to improve the shortcomings of TN type liquid crystal displays, among which optical The compensated bending (OCB) liquid crystal display has a fast response speed and is a very important liquid crystal display. However, before starting work, the OCB liquid crystal display needs to switch the liquid crystal molecules from the splay state to the bend state before the initial conversion phase, in order to work normally in the subsequent stages. However, it takes a few seconds for the optically compensated curved liquid crystal display to switch to a curved state, that is, when an optically compensated curved liquid crystal display is turned on, by providing a short period of high voltage, the liquid crystal molecules can be bent. The image is displayed normally. Conventional techniques apply a DC voltage to a co-energized 5 pole and shell electrode of an OCB liquid crystal display to energize liquid crystal molecules and transition from an unfolded state to a bent state. However, the use of a DC voltage usually causes polarization of liquid crystal molecules, and the conversion time required for this method is usually several seconds, which causes considerable inconvenience to the user. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a driving system and method for a liquid crystal display, thereby reducing the time spent in the initial conversion phase. Scanning signal image signal between substrates according to a preferred embodiment of the present invention, the driving system of the liquid crystal display comprises at least: a first substrate comprising a data electrode; a second substrate comprising a common electrode; and a liquid crystal layer comprising a plurality of liquid crystal molecules The first substrate and the second system are used for outputting a gate driver, electrically connected to the first substrate, the source driver is electrically connected to the first substrate, and the voltage selection device is The voltage selection signal is selected to rotate the first common electrode voltage or the second common electrode voltage to the common electrode, wherein the voltage selection signal is used to select an initial conversion phase or a normal display phase; and, in the above-mentioned liquid crystal display driving system, The first common electrode is repeatedly an alternating current signal, and includes a first-co-electrode „peak and a first-co-electrode Μ valley. Further, in the above-mentioned liquid crystal display driving system, the first common electrode electric waste peak is substantially Between 20V and 25V, and the first common electrode voltage valley is substantially between -7V and -12V. Also, in the above liquid crystal display Moving system, - of common electrode
U01413 又’在上述之液晶顯示器的驅動系統中，第-社帝&a 乐一共電極電 壓為交流訊號，係包含第二共電極電壓峰值與第二共電極 壓谷值。 、 又’在上述之液晶顯示器的驅動系統中，其中第_共電 極電麗導值之絕對值係實質上小於該第一共電極電壓峰值 之絕對值，且第二共電極電壓谷值之絕對值係實質上小於第 —共電極電壓谷值之絕對值。 又，在上述之液晶顯示器的驅動系統中，初始轉換階段 所需之初始時間係取決於該液晶層之複數個液晶分子從展 開（splay)狀態轉換至彎曲（bend)狀態所需之時間。 又’在上述之液晶顯示器的驅動系統中，初始時間係實 質上介於1秒至5秒之間。 又’在上述之液晶顯示器的液晶顯示器為一光學補償驚 曲液晶顯示器。 根據本發明之較佳實施例，液晶顯示器的驅動方法至少 包括：在一初始階段中，施加第一直流電壓至資料電極並施 加第父流電壓訊號至共通電極，使位於資料電極與共通電 極中間之複數個液晶分子從展開狀態轉換至彎曲狀態，其中 第一父流電壓訊號具有第一共電極電壓峰值和第一共電極 電壓谷值。 又，在上述之驅動方法中更包含：在正常顯示階段中， 施加第二直流電壓訊號至該共通電極，且第二直流電遷訊號 之絕對值係實質上介於第—方波電科值之絕對值與該第 7 1361413 一方波電壓谷值之絕對值之間β 又，在上述之驅動方法中，第一共電極電壓峰值係實質 介於20V與25V之間，而第一共電極電壓谷值係實質介於 •7V與-12V之間。 又，在上述之驅動方法中，第一交流電壓訊號之週期為 光學補償彎曲液晶顯示器掃瞄一圖框所需時間之兩倍。U01413 Further, in the above-mentioned liquid crystal display driving system, the first common electrode voltage is an alternating current signal, and includes a second common electrode voltage peak and a second common electrode valley value. Further, in the driving system of the liquid crystal display described above, wherein the absolute value of the first common electrode voltage is substantially smaller than the absolute value of the first common electrode voltage peak, and the absolute value of the second common electrode voltage valley is absolute The value is substantially less than the absolute value of the first-co-electrode voltage valley. Further, in the above-described driving system of the liquid crystal display, the initial time required for the initial conversion phase depends on the time required for the plurality of liquid crystal molecules of the liquid crystal layer to switch from the splay state to the bend state. Further, in the above-described driving system of the liquid crystal display, the initial time is substantially between 1 second and 5 seconds. Further, the liquid crystal display of the above liquid crystal display is an optically compensated stunning liquid crystal display. According to a preferred embodiment of the present invention, the driving method of the liquid crystal display includes at least: in an initial stage, applying a first DC voltage to the data electrode and applying a first parent voltage signal to the common electrode to be located between the data electrode and the common electrode The plurality of liquid crystal molecules are switched from an unfolded state to a bent state, wherein the first parent current voltage signal has a first common electrode voltage peak and a first common electrode voltage valley. Moreover, in the driving method, the method further includes: applying a second DC voltage signal to the common electrode in a normal display phase, and the absolute value of the second DC electromigration signal is substantially between the first-square wave electrical value The absolute value is between β and the absolute value of the 7 1361413 square wave voltage valley. In the above driving method, the first common electrode voltage peak is substantially between 20V and 25V, and the first common electrode voltage valley The value is essentially between •7V and -12V. Moreover, in the above driving method, the period of the first alternating current voltage signal is twice the time required for the optical compensation curved liquid crystal display to scan a frame.
【實施方式】[Embodiment]
凊參照第1圖，其係繪示本發明之液晶顯示器之驅動系 統的結構示意圖，其中液晶顯示器210包含基板212和214、 共通電極216、資料電極218、液晶層220、閘極驅動器222、 源極驅動器224以及電壓選擇裝置226。資料電極218位於 基板214中且基板214電性連接至閘極驅動器222和源極驅 動器224，共通電極216位於基板212中且基板212電性連 接至電壓選擇裝置226。液晶層220位於基板212和基板214 之間且包含複數個液晶分子228。源極驅動器224係用以輸 出影像信號至資料電極218，使資料電極218能控制液晶分 子228的排列方式，以顯示出影像信號所對應的影像於液晶 顯示器21〇之晝面中。問極驅動器222用以輸出掃猫信號來 控制影像信號是否輸出至資料電極218。電壓選擇裝置2% 電性連接至共通電極216，用以輸出第-共電極㈣和第二 共電極電壓來使液晶顯示器21〇正常操作。 2圖係繪示根據本發明之較 育料電極的電壓訊號示意 請參照第1圖和第2圖，第 佳實施例之施加至共通電極和 8 1361413 圖，其中曲線230a代表施加至共通電極216之第一共電極電 壓的波形；曲線230b代表施加至共通電極216之第二共電 極電壓的波形；曲線232a和232b為施加至資料電極218之 電壓訊號’本較佳實施例之液晶顯示器的驅動可分為初如轉 換階段234和正常顯示階段236。當電源開啟後，首先進入 初始轉換階段234,以使液晶分子228從展開狀態轉換到彎 曲狀態。在初始轉換階段234中，閘極驅動器222送出掃描 訊號以開啟液晶顯示器上所有的畫素，且此時施加至資料電 極218的電壓為一直流電壓訊號（如曲線232a.所示），例如： 為一顯示黑晝面或白畫面所對應的電壓值，而施加至共通電 極216的第一共電極電壓則為一交流電壓訊號（如曲線23〇& 所示），此父流電壓訊號具有第一共電極電壓電壓峰值 (VCOMH)和第一共電極電壓電壓谷值（vc〇ML)，其中 VCOMH係例如介於20V和25V之間，而VC〇ml係例如介 於-7V和-12V之間）。此階段係利用施加至共通電極216之交 流電壓訊號和施加至資料電極218之直流電壓之電壓差，來 擾動液晶分子228，並使液晶分子228快速累積能量，以減 少從展開狀態轉換到彎曲狀態所需的時間，因而減少液晶分 子228轉態的時間，並避免因直流電壓殘留而導致液晶分子 228發生極化的現象。另外，施加至共通電極216之第一共 電極電壓的週期為液晶顯示器2丨〇掃描一個圖框所需時間的 兩倍’以節省設計震盪電路的成本。 如第2圖所示’當液晶分子228從展開狀態轉換到彎曲 狀態後’即代表初始轉換階段234結束。此時，液晶顯示器 9 1361413 210便進入正常顯示階段236。在正常顯示階段236中，施 加至共通電極216的第二共電極電壓為直流電壓（如曲線 230b所示），而施加至資料電極218的電壓為對應於顯示畫 面之電壓值（如曲線232b所示之一方波電壓代表其極性隨畫 面改變），此階段係利用共通電極216與資料電極之間的電磨 差來控制液晶分子228之排列方式，以控制液晶顯示器21〇 之顯示（色彩）。Referring to FIG. 1 , which is a schematic structural view of a driving system of a liquid crystal display according to the present invention, wherein the liquid crystal display 210 includes substrates 212 and 214 , a common electrode 216 , a data electrode 218 , a liquid crystal layer 220 , a gate driver 222 , and a source . The pole driver 224 and the voltage selection device 226. The data electrode 218 is located in the substrate 214 and the substrate 214 is electrically connected to the gate driver 222 and the source driver 224. The common electrode 216 is located in the substrate 212 and the substrate 212 is electrically connected to the voltage selecting device 226. The liquid crystal layer 220 is located between the substrate 212 and the substrate 214 and includes a plurality of liquid crystal molecules 228. The source driver 224 is configured to output an image signal to the data electrode 218, so that the data electrode 218 can control the arrangement of the liquid crystal molecules 228 to display the image corresponding to the image signal in the plane of the liquid crystal display 21. The polarity driver 222 is configured to output a sweeping cat signal to control whether the image signal is output to the data electrode 218. The voltage selecting device 2% is electrically connected to the common electrode 216 for outputting the first common electrode (four) and the second common electrode voltage to cause the liquid crystal display 21 to operate normally. 2 is a diagram showing the voltage signal of the cultivating electrode according to the present invention. Referring to FIGS. 1 and 2, the preferred embodiment is applied to the common electrode and 8 1361413, wherein the curve 230a represents the application to the common electrode 216. The waveform of the first common electrode voltage; the curve 230b represents the waveform of the second common electrode voltage applied to the common electrode 216; and the curves 232a and 232b are the voltage signals applied to the data electrode 218 'the driving of the liquid crystal display of the preferred embodiment It can be divided into a preliminary conversion phase 234 and a normal display phase 236. When the power is turned on, the initial conversion phase 234 is first entered to cause the liquid crystal molecules 228 to transition from the unfolded state to the bent state. In the initial conversion phase 234, the gate driver 222 sends a scan signal to turn on all pixels on the liquid crystal display, and the voltage applied to the data electrode 218 at this time is a DC voltage signal (as shown by curve 232a.), for example: The first common electrode voltage applied to the common electrode 216 is an alternating current voltage signal (as shown by the curve 23〇&), and the parent current voltage signal has a voltage value corresponding to the black surface or the white screen. a first common electrode voltage voltage peak (VCOMH) and a first common electrode voltage voltage valley (vc 〇 ML), wherein the VCOMH system is, for example, between 20 V and 25 V, and the VC 〇 ml is, for example, between -7 V and -12 V. between). At this stage, the liquid crystal molecules 228 are disturbed by the voltage difference between the alternating voltage signal applied to the common electrode 216 and the direct current voltage applied to the data electrode 218, and the liquid crystal molecules 228 are rapidly accumulated to reduce the transition from the unfolded state to the bent state. The time required, thus reducing the time for the liquid crystal molecules 228 to transition, and avoiding the polarization of the liquid crystal molecules 228 due to residual DC voltage. In addition, the period of the first common electrode voltage applied to the common electrode 216 is twice the time required for the liquid crystal display 2 to scan a frame to save the cost of designing the oscillating circuit. As shown in Fig. 2, 'when the liquid crystal molecules 228 are switched from the unfolded state to the bent state', the initial transition phase 234 is terminated. At this point, the liquid crystal display 9 1361413 210 enters the normal display phase 236. In the normal display phase 236, the second common electrode voltage applied to the common electrode 216 is a DC voltage (as shown by curve 230b), and the voltage applied to the data electrode 218 is a voltage value corresponding to the display picture (as shown by curve 232b). One square wave voltage is shown as its polarity changes with the picture. In this stage, the electric ground difference between the common electrode 216 and the data electrode is used to control the arrangement of the liquid crystal molecules 228 to control the display (color) of the liquid crystal display 21 .
請參照第3圖’其係繪示根據本發明之另一較佳實施例 之施加至共通電極和資料電極的電壓訊號示意圖，其中曲線 240a代表施加至共通電極216之第一共電極電壓的波形； 240b代表施加至共通電極216之第二共電極電壓的波形；曲 線242a和242b為施加至資料電極218之電壓訊號，本較佳 實施例之液晶顯示器210的驅動亦具有初始轉換階段234和 正常顯不階段236。在正常顯示階段236中，施加至共通電 極216的第二共電極電壓為—交流電如曲線2鄕所、示），Please refer to FIG. 3, which is a schematic diagram showing voltage signals applied to a common electrode and a data electrode according to another preferred embodiment of the present invention, wherein a curve 240a represents a waveform of a first common electrode voltage applied to the common electrode 216. 240b represents the waveform of the second common electrode voltage applied to the common electrode 216; the curves 242a and 242b are the voltage signals applied to the data electrode 218, and the driving of the liquid crystal display 210 of the preferred embodiment also has an initial conversion phase 234 and normal No stage 236. In the normal display phase 236, the second common electrode voltage applied to the common electrode 216 is - alternating current as shown in curve 2, shown).
而施加至資料電極218的電壓為對應於顯示晝面之電壓值 (如曲線242b所示之一方波電壓代表其極性隨畫面改變）。正 韦頁示階& 236利用共通電極216和資料電極218之間的電 壓差來控制液晶分子228之排列方式，以控制液晶顯示器之 顯示（色彩）。在本較佳實施例中，第二共電極電壓之峰值的 絕對值係實質上小於第—共電極電壓峰值之絕對值，且第二 共電極電敎谷值㈣對值係實f上小於第—共電極電壓 谷值之絕對值。 請參照第1圖和第4圖，第4圖絲示根據本發明之較 10 1361413The voltage applied to the data electrode 218 is the voltage value corresponding to the display pupil plane (as one of the square wave voltages shown in curve 242b indicates that its polarity changes with the picture). The positive page & 236 utilizes the voltage difference between the common electrode 216 and the data electrode 218 to control the arrangement of the liquid crystal molecules 228 to control the display (color) of the liquid crystal display. In the preferred embodiment, the absolute value of the peak value of the second common electrode voltage is substantially smaller than the absolute value of the peak value of the first common electrode voltage, and the second common electrode electrode valley value (four) is less than the value of the value f - the absolute value of the common electrode voltage valley. Please refer to FIG. 1 and FIG. 4, and FIG. 4 shows the comparison according to the present invention. 10 1361413
佳實施例之電壓選擇裝置226的功能方塊示意圖，其中電壓 選擇裝置226於初始轉換階段234中輸出第一共電極電壓至 共通電極216;電壓選擇裝置226於正常顯示階段236中輸 出第一共電極電壓至共通電極216。電壓選擇裝置226係根 據電厪選擇訊號來選擇輪出第—共電極電践第二共電極 電壓’其中電壓選擇訊號係用以選擇液晶顯示器21〇處於初 始轉換階段234或正常顯示階段236卜在本較佳實施例 中’電壓選擇裝置226可為例如多工器（Mu_叫之组合。 電塵選擇裝置226之輸入端，點314 # 316係分別被施加 VCOMH和VC0ML ’其中⑽則和vc〇ml可由直流電 壓源或直流電流源來提供。電壓選擇裝置226之輸入端點 318被施加第二共電極電壓。電壓選擇裝置226可將 和VCOML組合成第一共電極電壓並根據控制端點32〇所接 收的電壓選擇訊號來從輸出端點322輸出第—共電極電壓或 第二共電極電壓至共通電極216。A functional block diagram of a voltage selection device 226 of a preferred embodiment in which the voltage selection device 226 outputs a first common electrode voltage to the common electrode 216 in an initial conversion phase 234; the voltage selection device 226 outputs a first common electrode in a normal display phase 236. The voltage is applied to the common electrode 216. The voltage selecting device 226 selects the second common electrode voltage of the first common electrode according to the power selection signal. The voltage selection signal is used to select the liquid crystal display 21 to be in the initial conversion phase 234 or the normal display phase 236. In the preferred embodiment, the voltage selection means 226 can be, for example, a multiplexer (Mu_called combination. The input of the dust selection device 226, point 314 # 316 is applied to VCOMH and VC0ML respectively, where (10) and vc 〇ml may be provided by a DC voltage source or a DC current source. A second common electrode voltage is applied to input terminal 318 of voltage selection device 226. Voltage selection device 226 may combine VCOML into a first common electrode voltage and according to the control endpoint The received voltage selection signal is 32 输出 to output a first common electrode voltage or a second common electrode voltage from the output terminal 322 to the common electrode 216.
由以上之敘述可知，本發明較佳實施例之液晶顯示 光學補償彎曲（OCB)液晶顯示器。本發明之較佳實施例不 提供可減少液晶顯示器中液晶分子轉態所需之時間之驅 方式，亦可以減少實施此驅動方式之成本，而且不需要再 行更改薄膜電晶體（TFT)和驅動ic之線路。 雖然本發明已以-較佳實施例揭露如上，然直並非用 限定本發明，任何熟習此技藝者，在不脫離本發明之精化 範圍内’當可作各種之更動與潤飾，因此本發明之保 當視後附之申請專利範圍所界定者為準。 & 11 【圖式簡單說明】 為讓本^明之上述和其他目的、特徵、和優點能更明顯 董下文特舉一較佳實施例，並配合所附圖式，作詳細說 明如下： 第1圖身示本發明之液晶顯示器之驅動系統的結構示意 圖。 第2圖繪不根據本發明之較佳實施例之施加至共通電極 和資料電極的電壓訊號示意圖。 第3圖繪不根據本發明之另一較佳實施例之施加至共通 電極和資料電極的電壓訊號示意圖。 第4圖繪示根據本發明之較佳實施例之電壓選擇裝置的 功能方塊示意圖。 【主要元件符號說明】 210 :液晶顯示器 212 :基板 214 :基板 216 :共通電極 218 :資料電極 220 :液晶層 222 :閘極驅動器 224 :源極驅動器 226 :電壓選擇裝置 228 :液晶分子 230a :曲線 230b :曲線 232a :曲線 232b :曲線 234 :初始轉換階段 236 :正常顯示階段 240a :曲線 240b :曲線 12 1361413 242a :曲線 3 14 :輸入端點 318 :輸入端點 322 :輸出端點 242b :曲線 3 16 :輸入端點 320 :控制端點 VCOMH :第一 共電極電壓電 VCOML· :第一共電極電壓電壓峰值 壓谷值As apparent from the above description, the liquid crystal display optical compensation bending (OCB) liquid crystal display of the preferred embodiment of the present invention. The preferred embodiment of the present invention does not provide a driving method for reducing the time required for the liquid crystal molecules to change state in the liquid crystal display, and can also reduce the cost of implementing the driving method, and does not need to change the thin film transistor (TFT) and the driving. Ic line. Although the present invention has been described above with reference to the preferred embodiments, the present invention is not intended to be limited thereto, and the present invention can be modified and retouched without departing from the scope of the invention. The warranty is subject to the definition of the scope of the patent application. BRIEF DESCRIPTION OF THE DRAWINGS [0009] The above and other objects, features, and advantages of the present invention will become more apparent. The figure shows a schematic structural view of a driving system of a liquid crystal display of the present invention. Figure 2 is a schematic diagram showing voltage signals applied to the common electrode and the data electrode in accordance with a preferred embodiment of the present invention. Figure 3 is a diagram showing voltage signals applied to the common electrode and the data electrode in accordance with another preferred embodiment of the present invention. Figure 4 is a block diagram showing the function of a voltage selecting device in accordance with a preferred embodiment of the present invention. [Main component symbol description] 210: Liquid crystal display 212: Substrate 214: Substrate 216: Common electrode 218: Data electrode 220: Liquid crystal layer 222: Gate driver 224: Source driver 226: Voltage selecting device 228: Liquid crystal molecule 230a: Curve 230b: Curve 232a: Curve 232b: Curve 234: Initial Conversion Phase 236: Normal Display Stage 240a: Curve 240b: Curve 12 1361413 242a: Curve 3 14: Input Endpoint 318: Input Endpoint 322: Output Endpoint 242b: Curve 3 16: Input terminal 320: control terminal VCOMH: first common electrode voltage power VCOML·: first common electrode voltage voltage peak valley value
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