201123154 六、發明說明： 【發明所屬之技術領域】 .201123154 VI. Description of the invention: [Technical field to which the invention belongs].
[0001] 本發明係關於一種液晶顯示器。 【先前彳支術】 [0002] 液晶顯示器因具有體積小、品質輕、厚度薄、耗電低、 不閃爍、輻射少等特性，已廣泛應用於電視、筆記型計 算機、行動電話、個人數位助理等電子設備。 [0003] 液晶顯示器通常包括一液晶顯示面板及一為該液晶顯示 面板提供平面光之背光模組。該液晶顯示面板通常包括 公共電極、畫素電極及複數受該公共電極及該畫素電極 驅動而扭轉之液晶分子。當施加到該公共電極及晝素電 極之間之電壓變化時，該液晶分子之扭轉角度不同，從 而該液晶顯示面板之光通過率不同，配合彩色濾光片即 可實現不同畫面之顯示。 [0004] 然而，液晶分子卻具有這樣一種特性：當加載到液晶分 子兩侧之電場方向長時間保持不變，液晶分子之物理特 性會遭到破壞，即無法再根據電場之變化來做相應之轉 動。因此，業界通常將反轉驅動方法應用於液晶顯示器 ，即每隔一定時間就改變加載到液晶層兩側之電場之方 、向，使液晶分子交替在相反之方向上偏轉，以防止其物 理特性遭到破壞。目前，液晶顯示器之反轉驅動方法包 括巾貞反轉驅動（Frame Inversion)、行反轉驅動 (Line/Row Inversion)、列反轉驅動（Column Inversion) 及點反轉驅動 （Dot Inversion)。 [0005] 在反轉驅動方法中，施加至該公共電極之公共電壓訊號 098144346 表單編號 A0101 第 4 頁/共 22 頁 0982075804-0 201123154 係一正負極性不斷交替變化之反轉電壓訊號，且頻率較 高，而該公共電極於該液晶顯示面板上係一面積較大層 狀結構，其被施加上述訊號易發生共振現象，而產生躁 聲，影響人們之工作及生活。 【發明内容】 [0006] [0007] ❹The present invention relates to a liquid crystal display. [Previous 彳 术 】 [0002] Liquid crystal display has been widely used in televisions, notebook computers, mobile phones, personal digital assistants due to its small size, light weight, thin thickness, low power consumption, no flicker, and low radiation. And other electronic equipment. [0003] A liquid crystal display generally includes a liquid crystal display panel and a backlight module that provides planar light for the liquid crystal display panel. The liquid crystal display panel generally includes a common electrode, a pixel electrode, and a plurality of liquid crystal molecules that are driven by the common electrode and the pixel electrode to be twisted. When the voltage applied between the common electrode and the halogen electrode changes, the twist angle of the liquid crystal molecules is different, so that the light transmittance of the liquid crystal display panel is different, and the display of different screens can be realized by using the color filter. [0004] However, liquid crystal molecules have such a characteristic that when the direction of the electric field applied to both sides of the liquid crystal molecules remains unchanged for a long time, the physical properties of the liquid crystal molecules are destroyed, that is, the corresponding changes in the electric field can no longer be made accordingly. Turn. Therefore, the industry generally applies an inversion driving method to a liquid crystal display, that is, changing the direction and direction of an electric field applied to both sides of the liquid crystal layer at regular intervals, so that liquid crystal molecules are alternately deflected in opposite directions to prevent physical properties thereof. been destroyed. Currently, liquid crystal display inversion driving methods include Frame Inversion, Line/Row Inversion, Column Inversion, and Dot Inversion. [0005] In the inversion driving method, the common voltage signal applied to the common electrode 098144346 Form No. A0101 Page 4 of 22 0982075804-0 201123154 is a reverse voltage signal with alternating positive and negative polarity, and the frequency is relatively high. The common electrode is a layered structure with a large area on the liquid crystal display panel, and the signal is applied to the resonance phenomenon, which causes a resonance phenomenon, which causes a noise and affects people's work and life. SUMMARY OF THE INVENTION [0006] [0007] ❹
[0008] 有鑑於此，有必要提供一種可以改善公共電壓產生之噪 聲之液晶顯示器。 一種液晶顯示器，其包括一液晶顯示面板、一掃描驅動 電路、一資料驅動電路及一公共電壓產生電路，該掃描 驅動電路用於施加一系列掃描訊號至該液晶顯示面板， 該資料驅動電路用於施加複數灰階電壓至該液晶顯示面 板，該公共電壓產生電路用於施加一公共電壓訊號至該 液晶顯示面板，該液晶顯示面板用於依序顯示每一幀畫 面，每一幀畫面時間定義一顯示時段，相鄰之兩幀畫面 之間之時間定義一空置時段，該公共電壓在該顯示時段 係一極性反轉訊號，該公共電壓在該空置時段係一直流 電壓訊號。 一種液晶顯示器，其包括一液晶顯示面板、一掃描驅動 電路、一資料驅動電路及一公共電壓產生電路，該掃描 驅動電路用於施加一系列掃描訊號至該液晶顯示面板， 該資料驅動電路用於施加複數灰階電壓至該液晶顯示面 板，該公共電壓產生電路用於施加一公共電壓訊號至該 液晶顯示面板，該液晶顯示面板用於依序顯示每一 Ψ貞畫 面，每一幀畫面時間定義一顯示時段，相鄰之兩幀晝面 之間之時間定義一空置時段，該公共電壓訊號在該顯示 098144346 表單編號A0101 第5頁/共22頁 0982075804-0 201123154 時段係一連續之方波訊號，該公共電壓訊號在該空置時 段電壓極性不變。 [0009] 一種液晶顯示器，其包括一液晶顯示面板、一掃描驅動 電路、一資料驅動電路及一公共電壓產生電路，該掃描 驅動電路用於施加一系列掃描訊號至該液晶顯示面板， 該資料驅動電路用於施加複數灰階電壓至該液晶顯示面 板，該公共電壓產生電路用於施加一公共電壓訊號至該 液晶顯示面板，該液晶顯示面板用於依序顯示每一巾貞晝 面，每一幀畫面時間定義一顯示時段，相鄰之兩幀畫面 之間之時間定義一空置時段，該公共電壓訊號在該顯示 時段係一連續之方波訊號，該公共電壓在該空置時段之 頻率比在該顯示時段之頻率低。 [0010] 與先前技術相比較，本發明液晶顯示器通過在相鄰之兩 幀畫面之空置時段，將該公共電壓設置直流電壓訊號， 使得該公共電壓在該空置時段固定不變或者極性不變或 者頻率較低，從而在整個時間段内該公共電壓引起之共 振現象被破壞，進而有效改善公共電壓產生噪聲之現象 〇 【實施方式】 [0011] 請參閱圖1，其係本發明液晶顯示器一較佳實施方式之等 效電路示意圖。該液晶顯示器1包括一液晶顯示面板10、 一掃描驅動電路11、一資料驅動電路12及一公共電壓產 生電路18。該掃描驅動電路用於掃描該液晶顯不面板10 ，其輸出一系列掃描電壓訊號至該液晶顯示面板10。該 資料驅動電路12用於在該液晶顯示面板10被掃描時施加 098144346 表單編號A0101 第6頁/共22頁 0982075804-0 201123154 [0012] ❹ [0013]In view of the above, it is necessary to provide a liquid crystal display that can improve the noise generated by a common voltage. A liquid crystal display comprising a liquid crystal display panel, a scan driving circuit, a data driving circuit and a common voltage generating circuit, wherein the scan driving circuit is configured to apply a series of scanning signals to the liquid crystal display panel, and the data driving circuit is used for Applying a plurality of gray scale voltages to the liquid crystal display panel, the common voltage generating circuit is configured to apply a common voltage signal to the liquid crystal display panel, wherein the liquid crystal display panel is configured to sequentially display each frame of the image, and each frame time defines one During the display period, the time between two adjacent frames defines a vacant period, and the common voltage is a polarity reversal signal during the display period, and the common voltage continuously flows a voltage signal during the vacant period. A liquid crystal display comprising a liquid crystal display panel, a scan driving circuit, a data driving circuit and a common voltage generating circuit, wherein the scan driving circuit is configured to apply a series of scanning signals to the liquid crystal display panel, and the data driving circuit is used for Applying a plurality of gray scale voltages to the liquid crystal display panel, the common voltage generating circuit is configured to apply a common voltage signal to the liquid crystal display panel, wherein the liquid crystal display panel is configured to display each frame in sequence, and each frame time definition In a display period, the time between two adjacent frames defines a vacant period, and the common voltage signal is a continuous square wave signal in the display 098144346 Form No. A0101 Page 5 / Total 22 Page 0982075804-0 201123154 The voltage of the common voltage signal does not change during the idle period. [0009] A liquid crystal display comprising a liquid crystal display panel, a scan driving circuit, a data driving circuit and a common voltage generating circuit, wherein the scan driving circuit is configured to apply a series of scanning signals to the liquid crystal display panel, and the data driving The circuit is configured to apply a plurality of gray scale voltages to the liquid crystal display panel, wherein the common voltage generating circuit is configured to apply a common voltage signal to the liquid crystal display panel, wherein the liquid crystal display panel is configured to sequentially display each of the mask surfaces, each The frame picture time defines a display period, and the time between the adjacent two frames defines a vacant period. The common voltage signal is a continuous square wave signal during the display period, and the frequency of the common voltage in the vacant period is greater than The frequency of the display period is low. [0010] Compared with the prior art, the liquid crystal display of the present invention sets the common voltage to a DC voltage signal during a vacant period of two adjacent frames, so that the common voltage is fixed or the polarity is unchanged during the vacant period or The frequency is low, so that the resonance phenomenon caused by the common voltage is destroyed in the whole time period, thereby effectively improving the phenomenon that the common voltage generates noise. [Embodiment] [0011] Please refer to FIG. 1 , which is a comparison of the liquid crystal display of the present invention. A schematic diagram of an equivalent circuit of a preferred embodiment. The liquid crystal display 1 includes a liquid crystal display panel 10, a scan driving circuit 11, a data driving circuit 12, and a common voltage generating circuit 18. The scan driving circuit is configured to scan the liquid crystal display panel 10, and output a series of scanning voltage signals to the liquid crystal display panel 10. The data driving circuit 12 is for applying 098144346 when the liquid crystal display panel 10 is scanned. Form No. A0101 Page 6 of 22 0982075804-0 201123154 [0012] ❹ [0013]
[0014] [0015] 複數灰階電壓訊號到該液晶顯示面板10。該公共電壓用 於輸出一公共電壓訊號至該液晶顯示面板1 0。 該液晶顯示面板10包括複數相互平行之掃描線13、複數 相互平行且與該掃描線13垂直絕緣相交之資料線14、複 數由該複數掃描線13與複數資料線14相交構成之最小矩 形區域定義之畫素單元16。該每一晝素單元16包括一薄 膜電晶體15、一畫素電極151及一公共電極152。每一薄 膜電晶體15包括一閘極（未標示）、一源極（未標示） 及一汲極（未標示），該閘極對應連接至對應之一掃描 線13，該源極連接至對應之一資料線14，該汲極連接至 該畫素電極151。每一晝素單元16中，該畫素電極151、 該公共電極152及夾於該畫素電極151、該公共電極152 之間之液晶層（圖未示）組成一液晶電容（未標示）。 該複數掃描線13分別連接至該掃描驅動電路11，用於接 收該一系列掃描電壓訊號。讓複數資料線14分別連接至 該資料驅動電路12，用於接收該複數灰階電壓訊號。該 複數公共電極152—併連接至該公共電壓產生電路18，用 於接收該公共電壓訊號。 請一併參閱圖2，其係圖1所示之液晶顯示器1之驅動訊號 波形圖。G1〜Gn分別表示該複數掃描線13上之複數掃描 電壓訊號之波形，Vd表示任意一資料線14上之灰階電壓 訊號之波形，Vcom表示該公共電極152上之公共電壓訊號 之波形。 該掃描電壓訊號實際上係一系列時間長度為T之高電壓脈 098144346 表單編號A0101 第7頁/共22頁 0982075804-0 201123154 衝。通常，該複數掃描線13被依序全部施加一次高電壓 脈衝之時間定義為一幀（f rame)畫面時間，且在一幀畫面 時間内之任意時刻，只有一條掃描線13被施加該高電壓 脈衝。進一步來講，在該複數掃描線13被依序施加高電 壓脈衝之一幀晝面時間内，該資料驅動電路12依序輸出 之代表一幀晝面之複數灰階電壓訊號分別被寫入每一個 晝素電極151，該公共電壓產生電路18輸出之公共電壓訊 號被寫入該複數公共電極152，進而使該液晶顯示器1之 所有畫素單元16均實現一次顯示，該液晶顯示器1顯示一 幀畫面，因此該一幀畫面時間也可以定義為該液晶顯示 器1之顯示時段。 [0016] 如圖2所示，具體而言，在第一幀晝面時間内，當一條掃 描線13被施加高電壓脈衝時，該高電壓脈衝使與該掃描 線電連接之複數薄膜電晶體15導通，同時，該資料驅動 電路12施加複數灰階電壓訊號至該複數資料線14，該複 數灰階電壓訊號分別通過該複數資料線14、該複數薄膜 電晶體15之源極及汲極對應寫入該複數畫素電極151，此 時，該公共電壓產生電路也輸出一公共電壓訊號至該複 數公共電極152，使得該畫素電極151與該公共電極152 構成之液晶電容具有一液晶爽壓驅動液晶分子扭轉’進 而該條掃描線13上之複數畫素單元16實現顯示。當該複 數掃描線13被依序全部施加一次高電壓脈衝後，該液晶 顯示器1之所有畫素單元16都實現一次顯示，即，該液晶 顯示器1實現第一幀畫面之顯示。其中，在第一幀畫面時 間内，該公共電壓訊號係一極性反轉訊號，詳細之說， 098144346 表單編號A0101 第8頁/共22頁 0982075804-0 201123154 [0017] Ο [0018] ❹ 該公共電壓訊號係一正負極性交替變化之方波脈衝訊號 ，其包括一正幅值及一負幅值，該正幅值可以為3V，及 負幅值可以為一3V。 通常，該資料驅動電路12係以幀為單位將接收到之晝面 資料轉化成複數灰階電壓訊號，並將一幀晝面之複數灰 階電壓訊號連續輸出，然而，該資料驅動電路12將一幀 畫面之複數灰階電壓訊號輸出完畢到開始輸出下一幀畫 面之複數灰階電壓訊號之前需要一定之準備時間（或者 說等待時間）。因此，該第一幀畫面完成顯示時至該第 二幀畫面開始顯示時之時間定義了一空置時段（Dummy Cycle)，即相鄰兩幀畫面之間之時間定義該空置時段， 該空置時段為該資料驅動電路12為顯示下一幀畫面所需 要之準備時間（或者說等待時間）。 當該液晶顯示器1已經完成顯示一幀畫面之顯示，該液晶 顯示器1將進入該空置時段。在該空置時段内，該掃描驅 動電路11可以施加到複數掃描線13相同之掃描電壓訊號 ，其中該掃描電壓訊號可以係一連續之複數高電壓脈衝 組成之方波；該資料驅動電路12可以重複施加第一幀畫 面之灰階電壓訊號到該複數資料線14，該灰階電壓訊號 也可以係一連續之脈衝方波；該公共電壓產生電路18則 輸出一極性不發生變化之公共電壓訊號至該複數公共電 極 152。 具體而言，該公共電壓訊號在該空置時段固定不變，其 可以為一直流電壓訊號，優選範圍為該公共電壓訊號在 顯示時段（即一幀畫面時間，比如該第一幀畫面時間） 098144346 表單編號A0101 第9頁/共22頁 0982075804-0 [⑻ 19] 201123154 之負幅值與正幅值之間，如一3 V至3 V。優選地，該直流 電壓訊號等於該正幅值及該負幅值之中間值，即該直流 電壓訊號優選值為0 V，係一接地電壓。 [0020] 該空置時段之具體長度可以根據該液晶顯示器1各電路及 元件之具體結構設置的，通常，對於240*320解晰度之液 晶顯示器，一幀畫面時間大致為16. 6ms，該空置時段可 以在3〜4 m s之間。 [0021] 當該資料驅動電路12已經完成顯示下一幀畫面之準備， 該液晶顯示器1將進入下一幀畫面時間，並不斷重複前述 一幀畫面時間及前面空置時段之所有動作與步驟。如圖2 所示，該液晶顯示器1進入第二幀畫面時間，在該第二幀 畫面時間内，該液晶顯示器1之各部分重複第一幀畫面時 間内之所有動作與步驟，以完成該第二幀畫面之顯示； 完成該第二幀畫面顯.示後，該液晶顯示器1再進一空置時 段並重複前一空置時段内之所有動作與步驟，此處就不 再贅述。 [0022] 請參閱圖3，其係圖1所示之液晶顯示器1與先前技術液晶 顯示器之噪聲測試結果之比較圖。其中，該噪聲測試之 環境要求如下：當環境中聲音（即環境中之噪聲）之頻率 在1kHz以下時，該環境中聲音之強度不高於10dB ;當環 境中聲音之頻率在1kHz以上時，該環境中聲音之強度不 高於5dB。圖3中，橫坐標表示聲音之頻率，單位為kHz ; 縱坐標表示聲音之頻率，單位為dB ;圓形點代表先前技 術液晶顯示器之噪聲測試結果；方形點代表本發明液晶 顯示器1之噪聲測試結果。 098144346 表單編號A0101 第10頁/共22頁 0982075804-0 201123154 [0023] Ο [0024] [0025] Ο [0026] 通過觀察圖3可知：先前技術液晶顯示器頻率在lkHz時之 聲音強度大概為8dB，本發明液晶顯示器！頻率在^心時 之聲音強度大概只有6dB ;先前技術液晶顯示器頻率在 3kHz時之聲音強度大概為UdB，而本發明液晶顯示器1 頻率在3kHz時之聲音強度大概為10dB ;先前技術液晶顯 不器頻率在5kHz時之聲音強度大概為i〇dB，本發明液晶 顯示器1頻率在5kHz時之聲音強度只有4dB。可以看出， 本發明液晶顯示器1產生之噪聲相對於先前技術液晶顯示 器有报大幅度之降低，有效改善了液晶顯示器產生之噪 聲問題。 與先前技術相比較’本發明液晶顯示器1在該相鄰兩幢晝 面之間之空置時段内，施加至該複數公共電極152之公共 電堡訊號固定不變，為一直流電壓訊號，從而破壞公共 電壓訊號極性反轉發生共振現象，進而有效改善公共電 髮產生噪聲之現象。 進一步地講’在該空置時段將該公共電壓訊號設置為〇v ’不僅可以有練改善公共電舞產生噪聲之現象，還可以 達到降低該液晶顯示器1之功耗，達到節省電能之效果。 然而’本發明液晶顯示器1並不限於上述實施方式所述， 如：在該空置時段’該複數掃描線13上之掃描電壓訊號 也可以都不相同’或者都沒有掃描電壓訊號；該資料線 14上之灰階電壓訊號也可以不是重複前巾貞晝面之灰階電 壓訊號，或者沒有灰階電壓訊號。因為該空置時段相對 於一幀晝面時間較短，即相對於顯示時段較短，人眼根 本沒辦法察覺到液晶顯示器1在該空置時段之畫面變化， 098144346 表單編號A0101 第11頁/共22頁 0982075804-0 201123154 所以無論該空置時段之掃描電壓訊號及灰階電壓訊號變 化如何，事實上並不會影響到該液晶顯示器1之畫面顯示 效果。 [0027] 請參閱圖4，其係本發明液晶顯示器一變形實施方式之公 共電壓訊號波形圖。該變形實施方式與該較佳實施方式 之液晶顯示器1之主要區別在於：在空置時段，該公共電 壓之極性係不變的，為正極性（或者負極性），但該公 共電壓之可以變化，優選地，在顯示時段之公共電壓訊 號之0V及正幅值範圍内（或者負幅值範圍内）變化。 0 [0028] 該變形實施方式中，該公共電壓之極性‘不變，也可以在 一定程度上破壞公共電壓訊號極性反轉發生共振現象， 進而有效改善公共電壓產生噪聲之現象。 [0029] 圖5係本發明液晶顯示器另一變形實施方式之公共電壓訊 號波形圖。該變形實施方式與該較佳實施方式之液晶顯 示器1之主要區別在於：在空置時段，該公共電壓之極性 變化，但其頻率較顯示時段之公共電壓訊號低，比如：[0014] A plurality of gray scale voltage signals are transmitted to the liquid crystal display panel 10. The common voltage is used to output a common voltage signal to the liquid crystal display panel 10. The liquid crystal display panel 10 includes a plurality of mutually parallel scan lines 13, a plurality of data lines 14 parallel to each other and perpendicularly insulated from the scan lines 13, and a minimum rectangular area defined by the complex lines 13 and the plurality of data lines 14 intersecting. The pixel unit 16. Each of the pixel units 16 includes a thin film transistor 15, a pixel electrode 151, and a common electrode 152. Each of the thin film transistors 15 includes a gate (not shown), a source (not labeled), and a drain (not labeled). The gate is correspondingly connected to a corresponding one of the scan lines 13, and the source is connected to the corresponding One of the data lines 14, the drain is connected to the pixel electrode 151. In each of the pixel units 16, the pixel electrode 151, the common electrode 152, and a liquid crystal layer (not shown) sandwiched between the pixel electrode 151 and the common electrode 152 constitute a liquid crystal capacitor (not shown). The plurality of scan lines 13 are respectively connected to the scan driving circuit 11 for receiving the series of scan voltage signals. The plurality of data lines 14 are respectively connected to the data driving circuit 12 for receiving the complex gray scale voltage signals. The plurality of common electrodes 152 are coupled to the common voltage generating circuit 18 for receiving the common voltage signal. Please refer to FIG. 2, which is a waveform diagram of the driving signal of the liquid crystal display 1 shown in FIG. G1 to Gn respectively represent the waveforms of the complex scanning voltage signals on the complex scanning line 13, Vd represents the waveform of the gray scale voltage signal on any of the data lines 14, and Vcom represents the waveform of the common voltage signal on the common electrode 152. The scan voltage signal is actually a series of high voltage pulses of length T 098144346 Form No. A0101 Page 7 / Total 22 Pages 0982075804-0 201123154 Punch. Generally, the time when the complex scan line 13 is applied with all the high voltage pulses in sequence is defined as a frame time, and at any time in one frame time, only one scan line 13 is applied with the high voltage. pulse. Further, during the time when the complex scan line 13 is sequentially applied with one of the high voltage pulses, the data driving circuit 12 sequentially outputs the complex gray scale voltage signals representing one frame of the frame, respectively. a pixel electrode 151, the common voltage signal outputted by the common voltage generating circuit 18 is written into the plurality of common electrodes 152, so that all the pixel units 16 of the liquid crystal display 1 are once displayed, and the liquid crystal display 1 displays one frame. The picture, so the one frame time can also be defined as the display period of the liquid crystal display 1. [0016] As shown in FIG. 2, specifically, during a first frame time, when a scan line 13 is applied with a high voltage pulse, the high voltage pulse causes a plurality of thin film transistors electrically connected to the scan line. 15 is turned on, and at the same time, the data driving circuit 12 applies a plurality of gray scale voltage signals to the plurality of data lines 14, and the plurality of gray scale voltage signals respectively pass through the plurality of data lines 14, the source and the drain of the plurality of thin film transistors 15 The common pixel generating electrode 151 is written, and the common voltage generating circuit also outputs a common voltage signal to the plurality of common electrodes 152, so that the liquid crystal capacitor formed by the pixel electrode 151 and the common electrode 152 has a liquid crystal pressure. The driving liquid crystal molecules are twisted' and the plurality of pixel units 16 on the scanning line 13 are displayed. After the plurality of scanning lines 13 are sequentially applied with a high voltage pulse, all of the pixel units 16 of the liquid crystal display 1 realize display once, that is, the liquid crystal display 1 realizes display of the first frame picture. Wherein, in the first frame picture time, the common voltage signal is a polarity inversion signal, in detail, 098144346 form number A0101 page 8 / total 22 page 0982075804-0 201123154 [0017] Ο [0018] ❹ the public The voltage signal is a square wave pulse signal with alternating positive and negative polarity, which includes a positive amplitude and a negative amplitude, the positive amplitude can be 3V, and the negative amplitude can be 3V. Generally, the data driving circuit 12 converts the received data into a complex grayscale voltage signal in units of frames, and continuously outputs a plurality of grayscale voltage signals of one frame, however, the data driving circuit 12 A certain preparation time (or waiting time) is required before the output of the complex gray scale voltage signal of one frame of the screen is completed until the start of outputting the complex gray scale voltage signal of the next frame. Therefore, the time when the first frame picture is completed and the time when the second frame picture starts to be displayed defines a Dummy Cycle, that is, the time between adjacent two frames defines the vacant time period, and the vacant time period is The data driving circuit 12 is a preparation time (or waiting time) required to display the next frame picture. When the liquid crystal display 1 has finished displaying the display of one frame of picture, the liquid crystal display 1 will enter the vacant period. During the vacant period, the scan driving circuit 11 can apply the same scan voltage signal to the plurality of scan lines 13, wherein the scan voltage signal can be a continuous square wave composed of a plurality of high voltage pulses; the data driving circuit 12 can be repeated. Applying a grayscale voltage signal of the first frame to the complex data line 14, the grayscale voltage signal may also be a continuous pulse square wave; the common voltage generating circuit 18 outputs a common voltage signal whose polarity does not change to The plurality of common electrodes 152. Specifically, the common voltage signal is fixed during the vacant period, and may be a DC voltage signal, and the preferred range is that the common voltage signal is in a display period (ie, one frame time, such as the first frame time) 098144346 Form No. A0101 Page 9 of 22 0982075804-0 [(8) 19] The negative amplitude and positive amplitude of 201123154, such as a 3 V to 3 V. Preferably, the DC voltage signal is equal to the middle value of the positive amplitude value and the negative amplitude value, that is, the DC voltage signal preferably has a value of 0 V and is a ground voltage. [0020] The vacant period of the liquid crystal display 1 according to the specific structure of the circuit and the components of the liquid crystal display 1, the frame time is generally 16.6ms, the vacant for a liquid crystal display of 240*320 resolution The time period can be between 3 and 4 ms. [0021] When the data driving circuit 12 has finished preparing to display the next frame picture, the liquid crystal display 1 will enter the next frame time and continuously repeat all the actions and steps of the previous frame time and the previous vacant time period. As shown in FIG. 2, the liquid crystal display 1 enters a second frame time, and in the second frame time, each part of the liquid crystal display 1 repeats all the actions and steps in the first frame time to complete the first After the second frame is displayed, the liquid crystal display 1 enters a vacant time period and repeats all the actions and steps in the previous vacant time period, and details are not described herein. [0022] Please refer to FIG. 3, which is a comparison diagram of the noise test results of the liquid crystal display 1 shown in FIG. 1 and the prior art liquid crystal display. The environmental requirements of the noise test are as follows: when the frequency of the sound in the environment (ie, the noise in the environment) is below 1 kHz, the intensity of the sound in the environment is not higher than 10 dB; when the frequency of the sound in the environment is above 1 kHz, The intensity of the sound in this environment is not higher than 5 dB. In Fig. 3, the abscissa indicates the frequency of the sound, the unit is kHz; the ordinate indicates the frequency of the sound, the unit is dB; the circle point represents the noise test result of the prior art liquid crystal display; the square point represents the noise test of the liquid crystal display 1 of the present invention. result. 098144346 Form No. A0101 Page 10 / Total 22 Page 0992075804-0 201123154 [0023] [0025] [0026] By observing FIG. 3, it can be seen that the sound intensity of the prior art liquid crystal display at 1 kHz is about 8 dB. The liquid crystal display of the invention! The sound intensity of the frequency is only 6dB when the heart is at the heart; the sound intensity of the prior art liquid crystal display frequency is about UdB at 3kHz, and the sound intensity of the liquid crystal display 1 of the present invention is about 10dB at 3kHz; the prior art liquid crystal display The sound intensity at a frequency of 5 kHz is approximately i 〇 dB, and the sound intensity of the liquid crystal display 1 of the present invention at 5 kHz is only 4 dB. It can be seen that the noise generated by the liquid crystal display 1 of the present invention is significantly reduced compared with the prior art liquid crystal display, which effectively improves the noise problem generated by the liquid crystal display. Compared with the prior art, the public electric castle signal applied to the plurality of common electrodes 152 is fixed during the vacant period between the adjacent two sides of the liquid crystal display 1 as a constant current voltage signal, thereby destroying The reversal of the polarity of the common voltage signal causes a resonance phenomenon, thereby effectively improving the phenomenon of noise generated by the public electric power. Further, the setting of the common voltage signal to 〇v ’ during the vacant period can not only improve the noise generated by the public electric dance, but also reduce the power consumption of the liquid crystal display 1 to save power. However, the liquid crystal display 1 of the present invention is not limited to the above embodiments, for example, the scanning voltage signals on the plurality of scanning lines 13 may not be the same during the vacant period or none of the scanning voltage signals; the data line 14 The gray scale voltage signal on the upper side may not be the gray scale voltage signal of the front cover, or the gray scale voltage signal. Since the vacant period is shorter than the frame time of one frame, that is, the display period is shorter, the human eye has no way of perceiving the change of the screen of the liquid crystal display 1 during the vacant period, 098144346 Form No. A0101 Page 11 of 22 Page 0982075804-0 201123154 Therefore, regardless of the change of the scanning voltage signal and the gray scale voltage signal during the vacant period, the screen display effect of the liquid crystal display 1 is not actually affected. Please refer to FIG. 4, which is a waveform diagram of a common voltage signal of a modified embodiment of the liquid crystal display of the present invention. The main difference between the modified embodiment and the liquid crystal display 1 of the preferred embodiment is that the polarity of the common voltage is constant during the vacant period, and is positive (or negative), but the common voltage can be changed. Preferably, it varies within a range of 0V and a positive amplitude of the common voltage signal of the display period (or within a range of negative amplitude values). [0028] In the variant embodiment, the polarity of the common voltage is 'unchanged, and the resonance phenomenon of the polarity reversal of the common voltage signal may be broken to some extent, thereby effectively improving the noise generated by the common voltage. 5 is a waveform diagram of a common voltage signal of another modified embodiment of the liquid crystal display of the present invention. The main difference between the modified embodiment and the liquid crystal display 1 of the preferred embodiment is that the polarity of the common voltage changes during the vacant period, but the frequency is lower than the common voltage signal of the display period, for example:
U 該公共電壓在空置時段之頻率為在顯示時段之頻率之二 分之一。 [0030] 該變形實施方式中，該公共電壓在空置時段之頻率為在 顯示時段之頻率低，同樣可以在一定程度上破壞公共電 壓訊號極性反轉發生共振現象，進而有效改善公共電壓 產生噪聲之現象。 [0031] 綜上所述，本發明確已符合發明專利之要件，爰依法提 出專利申請。惟，以上所述者僅為本發明之較佳實施方 098144346 表單編號A0101 第12頁/共22頁 0982075804-0 201123154 式，本發明之範圍並不以上述實施例為限，該舉凡熟悉 本案技藝之人士援依本發明之精神所作之等效修飾或變 化，皆應涵蓋於以下申請專利範圍内。 【圖式簡單說明】 [0032] 圖1係本發明液晶顯示器一較佳實施方式之等效電路示意 圖。 [0033] [0034] [0035] [0036]U The frequency of the common voltage during the vacant period is one-half of the frequency of the display period. [0030] In the modified embodiment, the frequency of the common voltage in the vacant period is low in the display period, and the resonance phenomenon of the polarity reversal of the common voltage signal may be broken to some extent, thereby effectively improving the noise generated by the common voltage. phenomenon. [0031] In summary, the present invention has indeed met the requirements of the invention patent, and the patent application is filed according to law. However, the above description is only the preferred embodiment of the present invention 098,144,346, Form No. A0101, Page 12 of 22, 0982075804-0, 201123154, and the scope of the present invention is not limited to the above embodiments, and the skill of the present invention is familiar to the present invention. Equivalent modifications or variations made by persons in light of the spirit of the invention are intended to be included within the scope of the following claims. BRIEF DESCRIPTION OF THE DRAWINGS [0032] FIG. 1 is a schematic diagram showing an equivalent circuit of a preferred embodiment of a liquid crystal display of the present invention. [0036] [0036] [0036]
[0037] [0038] [0039] [0040] [0041] [0042] [0043] [0044][0038] [0044] [0044] [0044]
圖2係圖1所示之液晶顯示器之驅動訊號波形圖。 圖3係圖1所示之液晶顯示器與先前技術液晶顯示器之噪 聲測試結果之比較圖。 圖4係本發明液晶顯示器一變形實施方式之公共電壓訊號 波形圖。 圖5係本發明液晶顯示器另一變形實施方式之公共電壓訊 號波形圖。 【主要兀件符说S兒明】 . ..: ..丨. 液晶顯不 Is · 1 i': " ...... ，^ ， 掃描驅動電路：11 資料驅動電路：12 液晶顯示面板：1 0 掃描線：13 資料線：14 畫素單元：16 薄膜電晶體：15 098144346 表單編號A0101 第13頁/共22頁 0982075804-0 201123154 [0045] 晝素電極：151 [0046] 公共電極：152 [0047] 公共電壓產生電路：182 is a waveform diagram of driving signals of the liquid crystal display shown in FIG. 1. Figure 3 is a graph comparing the noise test results of the liquid crystal display shown in Figure 1 and the prior art liquid crystal display. Fig. 4 is a waveform diagram showing a common voltage signal of a modified embodiment of the liquid crystal display of the present invention. Fig. 5 is a waveform diagram showing a common voltage signal of another modified embodiment of the liquid crystal display of the present invention. [The main element says S children] . ..: ..丨. LCD display is not · 1 i': " ...... , ^ , scan drive circuit: 11 data drive circuit: 12 liquid crystal display Panel: 10 Scan Line: 13 Data Line: 14 Pixel Unit: 16 Thin Film Transistor: 15 098144346 Form No. A0101 Page 13 / Total 22 Page 0992075804-0 201123154 [0045] Alizarin Electrode: 151 [0046] Common Electrode :152 [0047] Common voltage generation circuit: 18
098144346 表單編號A0101 第14頁/共22頁 0982075804-0098144346 Form No. A0101 Page 14 of 22 0982075804-0