200832311 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 ; 0CB)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 低耗旎的優點，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類型的液晶顧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 裔的缺點，其中光學補償彎曲（〇CB)液晶顯示器反應速度 快’疋相當重要的一種液晶顯示器。然而，〇Cb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 正常地工作。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0CB液晶顯示器的共通電 5 200832311 極和資料f極，來使液晶分子獲得能量，並從展開狀離轉換 至彎曲狀態。㈣，使用直流電麼通常會導致液晶分ς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。 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-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__基板盘第二 ，板之間；閘極驅動器，電性連祕第—基板，係用;;輸: 掃描信號；源極驅動器’電性連接於第—基板，係用以輪出 影隸號；以及電壓選擇裝置’根據電壓選擇訊號來選擇輪 出第共電極電壓或第二共電極電壓至共通電極，其中電壤 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 壓為交流訊號’係包含第—共電極電壓峰值與第一共電極泰 壓谷值。 甩 又，在上述之液晶顯示器的驅動系統中，第一共電極 壓峰值係實質介於游與25V之間，而第—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，第一共電極電 壓之責任週期為液晶顯示器掃描—圖框伽削)所需時間之 6 200832311 兩倍。 又，在上述之液晶顯示器的驅動系統中，第二共電極電 麼為交流訊號，係包含第二共電極電麼峰值與第二共極: 壓谷值。 ^ 电 又，在上述之液晶顯示器的驅動系統中，其中第二共電 極電壓峰值之絕對值係實質上小於該第一共電極電^值 之絕對值，且第二共電極電Μ谷值之絕對值係實質上小 一共電極電壓谷值之絕對值。 、 、 又，在上述之液晶顯示器的驅㈣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 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， 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 曲液晶顯示器。 兀于補彳貝弓 根據本發明之較佳實施例，液晶顯示器的_方法至少 包括：在一初始階段中，施加第一 知當L電昼至資料電極並施 加弟-父流電壓訊號至共通電極，使位於資料電極與共通電 ，中間之複數個液晶分子從展開狀態轉換至彎曲狀離，並中 電壓訊號具有第一共電極電壓峰值和第一共電極 施加Γ ΪΪ述之縣方法中更包含：在正f顯示階段中， 轭加弟二直流電壓訊號至該 之絕對值係實質上介於第一方波電祕;—直流電壓訊號 万波電壓峰值之絕對值與該第 200832311 一方波電壓谷值之絕對值之間。 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。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 bending (Octically Compensated Bend; 0CB) 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 power 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. The TN type liquid crystal display has the advantages of high image contrast value and easy manufacture, but due to its slow response speed and narrow viewing angle, other types of liquid crystal displays have been developed to improve the shortcomings of TN type liquid crystal display. Among them, the optical compensation bending (〇CB) liquid crystal display has a fast response speed, which is quite important for a liquid crystal display. However, before starting work, the 〇Cb 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. The conventional technique applies a direct current voltage to a common current of a 0CB liquid crystal display. The light source and the data f pole are used to obtain energy for the liquid crystal molecules and switch from the unfolded state to the curved state. (4) The use of DC power usually causes polarization of the liquid crystal bifurcation, and the conversion time required for this method is usually several seconds: it 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. According to a preferred embodiment of the present invention, the driving system of the liquid crystal display includes at least: the first substrate includes a data electrode; the second substrate includes a common electrode, and the liquid crystal layer 'comprises a plurality of liquid crystal molecules, which are located in the first __ substrate Second, between the plates; gate driver, electrical connection secret - substrate, system;; input: scanning signal; source driver 'electrically connected to the first substrate, used to turn out the film number; and voltage The selecting device 'selects to rotate the common electrode voltage or the second common electrode voltage to the common electrode according to the voltage selection signal, wherein the electric ground selection signal is used to select an initial conversion phase or a normal display phase; and 'in the above liquid crystal display In the driving system, the first common electrode voltage is an alternating current signal, which includes a first common electrode voltage peak and a first common electrode voltage valley. Further, in the above-described driving system of the liquid crystal display, the first common electrode voltage peak is substantially between 25 V and the first common electrode voltage valley is substantially between -7 V and -12 V. Moreover, in the above-mentioned driving system of the liquid crystal display, the duty cycle of the first common electrode voltage is twice the time required for the liquid crystal display scanning-frame gamma. Further, in the driving system of the liquid crystal display described above, the second common electrode is an alternating current signal including a second common electrode peak and a second common pole: valley value. In addition, in the above-mentioned driving system of the liquid crystal display, wherein the absolute value of the second common electrode voltage peak is substantially smaller than the absolute value of the first common electrode voltage, and the second common electrode electric enthalpy The absolute value is the absolute value of the substantially one common electrode voltage valley. In addition, in the above-mentioned liquid crystal display (CD), the initial time required for the initial conversion phase depends on the conversion of a plurality of liquid crystal molecules of the liquid crystal layer from a splay state to a bend state. time. "In addition, in the above-mentioned liquid crystal display driving system, the quality is between 1 second and 5 seconds. Further, the liquid crystal display of the liquid crystal display described above is a curved liquid crystal display. 兀于补彳贝弓 according to the present invention In a preferred embodiment, the method of the liquid crystal display includes, at least in an initial stage, applying a first known L electric power to the data electrode and applying a di-parent voltage signal to the common electrode to cause the data electrode to be co-energized. The middle plurality of liquid crystal molecules are switched from the unfolded state to the curved state, and the middle voltage signal has the first common electrode voltage peak and the first common electrode is applied. The county method further includes: in the positive f display phase, the yoke The absolute value of the DC voltage signal from the Kadi II is substantially between the first square wave and the secret; the absolute value of the peak value of the DC voltage signal and the absolute value of the voltage peak of the 200832311 square wave. In the above driving method, the first common electrode voltage peak is substantially between 20V and 25V, and the first common electrode voltage valley is substantially between -7V and -12V. The driving method of the above, the first cycle of the AC voltage signal of a liquid crystal display is bent twice as the time required to scan a frame of optical compensation.
【實施方式】 請參照第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《 動器224，共通電極216位於基板212中且基板212電性驾 接至電壓選擇裝置226。液晶層220位於基板212和基板21 之間且包含複數個液晶分子228。源極驅動器224係用以輕 出影像仏號至貧料電極218，使資料電極218能控制液晶$ 子228的排列方式，以顯示出影像信號所對應的影像於液盖 顯示器21〇之晝面中。閘極驅動器222用以輸出掃瞄_ 控制影像信號是否輸出至資料電極218。電壓選擇裝置22 電性連接至共通電^16,用以輸出第一共電極電壓和第二 共電極電壓來使液晶顯示器210正常操作。 請參照第1圖和第2圖，第？同你— .^ 弟2圖係繪示根據本發明之泰 1土貝施例之施加至共通電極和认 今貝料電極的電壓訊號示| 200832311 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始轉 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晝素，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晝面所對應的電壓值，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230a 所示），此交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（VCOML)，其中 VCOMH係例如介於20V和25V之間，而VCOML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210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 200832311 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晝 面改i：)’此階段係利用共通電極216與資料電極之間的電壓 差來控制液晶分子228之排列方式，以控制液晶顯示器21〇 之顯示（色彩）。[Embodiment] Please refer to FIG. 1 , which is a schematic structural diagram of a driving system of a liquid crystal display according to the present invention. The liquid crystal display 210 includes substrates 212 and 214 , a common electrode 216 , a data electrode 218 , a liquid crystal layer 220 , and a gate electrode . Driver 222, source driver 224, and 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 actuator 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 21 and includes a plurality of liquid crystal molecules 228. The source driver 224 is configured to light the image nickname to the poor electrode 218, so that the data electrode 218 can control the arrangement of the liquid crystal 228 to display the image corresponding to the image signal on the liquid cover display 21 in. The gate driver 222 is configured to output a scan_control image signal to be output to the data electrode 218. The voltage selecting device 22 is electrically connected to the common power source 16 for outputting the first common electrode voltage and the second common electrode voltage to cause the liquid crystal display 210 to operate normally. Please refer to Figure 1 and Figure 2, the first? 。^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 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; the curves 232a and 232b are the voltage signals applied to the data electrode 218, and the driving of the liquid crystal display of the preferred embodiment can be It is divided into an initial 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 the pixels on the liquid crystal display, and the voltage applied to the data electrode 218 is a DC voltage signal (as shown by curve 232a), for example: A voltage value corresponding to the black surface or the white surface is displayed, and the first common electrode voltage applied to the common electrode 216 is an alternating current voltage signal (as shown by a curve 230a), and the alternating voltage signal has a first common electrode voltage. The voltage peak (VCOMH) and the first common electrode voltage voltage valley (VCOML), wherein VCOMH is, for example, between 20V and 25V, and VCOML is, for example, between -7V and -12V. 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 210 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 time, the liquid crystal display 9 200832311 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). A square wave voltage is shown to change its polarity with the surface change i:) 'This stage uses the voltage difference between the common electrode 216 and the data electrode to control the arrangement of the liquid crystal molecules 228 to control the display of the liquid crystal display 21 (color) ).
請參照第3冑，其係緣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的驅動亦詩初始轉換階段234和 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—交流電壓（如曲線鳩所示卜 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-方波電壓代表其極性隨晝面改變）。正 常顯示階段236利用共通電極216和資料電極2 i 8之間的 壓差來控制液晶分子228之排列方式，以控制液晶顯示器之 顯不（色彩）。在本較佳實施财，第二共電極電壓之峰 絕對值係實質上小於第—共電極電壓峰值之絕對值，且第二 共電極電塵之谷值的絕對值係實質上小於第一共； 谷值之絕對值。 % ^ 請參照第1圖和第情，第4圖係清示根據本發明之較 200832311 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 出第二共電極電壓至共通電極216。電壓選擇裝置226係根 據電壓選擇訊號來選擇輸出第一共電極電壓或第二共電極 電壓，其中電壓選擇訊號係用以選擇液晶顯示器210處於初 始轉換階段234或正常顯示階段236中。在本較佳實施例 中，電壓選擇裝置226可為例如多工器（Multiplexer)之組合。 電壓選擇裝置226之輸入端點314和316係分別被施加 VCOMH和VCOML，其中VCOMH和VCOML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。電屋選擇裝置226可將VCOMH 和VCOML組合成第一共電極電壓並根據控制端點320所接 收的電壓選擇訊號來從輸出端點322輸出第一共電極電壓或 第二共電極電壓至共通電極216。 由以上之敘述可知，本發明較佳實施例之液晶顯示器為 光學補償彎曲（OCB)液晶顯示器。本發明之較佳實施例不但 提供可減少液晶顯示器中液晶分子轉態所需之時間之驅動 方式，亦可以減少實施此驅動方式之成本，而且不需要再另 行更改薄膜電晶體(TFT)和驅動1C之線路。 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，任何熟習此技藝者，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。 11 200832311 【圖式簡單說明】 為讓本發明之上述和其他目的、特徵、和優點能更明顯 易卜下文特舉-較佳實施例，並配合所附圖式，作詳 明如下： 第1圖繪示本發明之液晶顯示器之驅動系統的結構示意 圖。 ^ 一第2圖繪示根據本發明之較佳實施例之施加至共通電極 和貪料電極的電壓訊號示意圖。 “第3圖緣示根據本發明之另一較佳實施例之施加至共通 電極和貧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 2 2 8 ·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 200832311 242a :曲線 314 :輸入端點 3 18 :輸入端點 322 :輸出端點 242b :曲線 316 :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 13Please refer to FIG. 3 for a voltage signal diagram applied to the common electrode and the data electrode according to another preferred embodiment of the present invention, wherein the curve 240a represents the waveform of the 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 is also the initial conversion stage 234 and normal. Stage 236 is displayed. In the normal display phase 236, the second common electrode voltage applied to the common electrode 216 is an alternating current voltage (as shown by the curve 而, the voltage applied to the data electrode 218 is a voltage value corresponding to the display pupil surface (eg, curve 242b) The square wave voltage shown represents its polarity changing with the surface. The normal display phase 236 uses the voltage difference between the common electrode 216 and the data electrode 2 i 8 to control the arrangement of the liquid crystal molecules 228 to control the display of the liquid crystal display. No (color). In the preferred embodiment, the absolute value of the peak 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 absolute value of the valley value of the second common electrode dust is the essence. The upper limit is less than the first total; the absolute value of the valley value. % ^ Please refer to FIG. 1 and the first case, and FIG. 4 is a functional block diagram showing the voltage selection device 226 according to the preferred embodiment of the present invention. The selection device 226 outputs the first common electrode voltage to the common electrode 216 in the initial conversion phase 234; the voltage selection device 226 outputs the second common electrode voltage to the common electrode 216 in the normal display phase 236. The voltage selection device 226 selectively outputs the first common electrode voltage or the second common electrode voltage according to the voltage selection signal, wherein the voltage selection signal is used to select the liquid crystal display 210 to be in the initial conversion phase 234 or the normal display phase 236. In a preferred embodiment, voltage selection device 226 can be, for example, a combination of multiplexers. Input terminals 314 and 316 of voltage selection device 226 are applied with VCOMH and VCOML, respectively, where VCOMH and VCOML can be from a DC voltage source or DC. A current source is provided. The input terminal 318 of the voltage selection device 226 is applied with a second common electrode voltage. The house selection device 226 can combine VCOMH and VCOML into a first common electrode voltage and select according to the voltage received by the control terminal 320. The signal outputs the first common electrode voltage or the second common electrode voltage from the output terminal 322 to the common electrode 216. As apparent from the above description, the liquid crystal display of the preferred embodiment of the present invention is an optically compensated curved (OCB) liquid crystal display. The preferred embodiment of the invention not only provides a driver for reducing the time required for the transition of liquid crystal molecules in a liquid crystal display. The cost of implementing the driving method can also be reduced, and the thin film transistor (TFT) and the circuit for driving 1C need not be changed separately. Although the present invention has been disclosed above in a preferred embodiment, it is not intended to limit the present invention. The invention is to be understood as being limited by the scope of the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects, features, and advantages of the present invention will become more apparent. 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 a common electrode and a greedy electrode in accordance with a preferred embodiment of the present invention. 3 is a schematic diagram showing voltage signals applied to a common electrode and a lean electrode according to another preferred embodiment of the present invention. FIG. 4 is a block diagram showing a function of a voltage selecting device according to a preferred embodiment of the present invention. Schematic diagram [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 selection device 2 2 8 • Liquid crystal Molecular 230a: curve 230b: curve 232a - curve 232b · curve 234: initial conversion phase 236: normal display phase 240a: curve 240b: curve 12 200832311 242a: curve 314: input endpoint 3 18: input endpoint 322: output Point 242b: Curve 316: Input Endpoint 320: Control Endpoint VCOMH: First Common Electrode Voltage Power VCOML···First Common Electrode Voltage Voltage Peak Valley 13