单机外设模块驱动原理

1、A light valveLight valveLight source加電場狀態電場TN-LCD基本操作未加電場狀態偏光板背光源解偏板亮態暗態液晶分子出射光之極化狀態液晶是受電場影響而扮演光閘的角色那電場是如產生的呢.TFT 面板的結構Data LineGate Line Sub_Pixel面板是由Gate_Line與 Data_Line組成的一個矩陣結構Sub_Pixel的結構Gate_LineData_LineITOTFT(Switch)高電壓高電壓TFT導通電流通過低電壓TFT打開電流不過Sub_Pixel產生電場的流程上下電極板array上的ITO(Signal)與CF上的ITO(

2、)ClcRGBClcClcRBGColor Filter Substrate( )TFT Substrate(Charge)ClcTFT SubstrateColor Filter SubstrateRGBClcClcRBGSub_Pixel產生電場的流程Data LineGate LinePixelTFTSignal on data line當TFT關掉時，電荷仍會被保存在Pixel上，電場會持續Sub_Pixel產生電場的流程由上頁可知，電場是由Pixel上的電荷產生因此，Pixel上所充的電荷多寡會影響LCD顯示畫面的亮暗那麼，是誰控制Pixel上的電荷多寡複習一下吧.當Gate_Lin

3、e有個高電壓(pulse)進來時，TFT被導通data line開始對Pixel充電,且其電壓大小決定Pixel可以充多少電荷利用Pixel上電荷的多寡決定電場大小液晶就是依所受的電場大小去控制光的穿透量RGGR由此可知，真正主宰Pixel充多少電荷的是Gate_Line與Data_LineGate_Line(二)決定時序Timevoltagepulse(一)利用pulse控制TFT開或關Pulse進來TFT 導通Pulse離開TFT OpenA switch controlled by scan lineSelected rowNon-selected rowT= 0 sectimeVolt

4、ageG1G2t=0t=1A switch controlled by scan lineGate_Line：Scan 讓每一“行”的pixel有“時序性”的被控制T= 1 secNon-Selected rowSelected row那Data Line上面的電壓是.當TFT處於on的階段data line上的電壓大小決定Pixel可以充多少電荷利用Pixel上電荷的多寡決定電場大小液晶就是依所受的電場大小去控制光的穿透量RGGRData Line控制亮暗那Data Line上面的電壓是. DC Bias of CommonGray Scale Voltage 1 Frame / 1 Lin

5、eV0V16V16V48V48V63V63V32V32Transmittance(%)100%VoltageV16V32V48V63畫面示意圖Selected rowNon-selected rowT= 0 secV16V48V16畫面示意圖T= 1 secNon-Selected rowselected rowV48V16V48那Data Line上面的電壓是. DC Bias of CommonGray Scale Voltage 1 Frame / 1 LineV0V16V16V48V48V64V64V32V32Transmittance(%)100%Voltage利用數位式訊號控制亮暗

6、V16V32V48V64t1以一個畫面來看Gate line driving waveformG1G2G3GNG1TimeVoltageG1G2G3Frame TimeData Line 1NVoltageData line driving waveformt1t2t3tNV64Frame rate = 60 Hz代表Frame time = 1/60 sec= 畫面每秒更新60次Data lineScan lineA sub-pixelA pixel = R sub-pixel + G sub-pixel + B sub-pixel再加上CF產生顏色即可產生一張美麗的畫面簡單的驅動原理就介紹

7、到此接下來就為各位介紹真實驅動上產生的兩個Issue1.AC Driving2.Flicker IntroduceAC DrivingWhy ac driving?V0V1V2V62V63V63V62V2V1V0Common WaveformGraylevel Voltage1Frame / 1 LineBecause DC driving will cause LC damaged.AC Driving _Frame InversionV16V0 DC Bias of CommonGray Scale Voltage N FrameN+1 FrameFrame NV48Frame N+1 +

8、-VlcVLC(+) VLC(-) +-VlcVLC(+) VLC(-) +Vlc +Vlc +VlcFlickerFlicker due to non-uniformity. -Vlc -Vlc -Vlc解決方式 : Dot_Inversion +-VLC(+)VLC(-)何謂Dot InversionFrame nFrame n+1Frame inversionFrame nFrame n+1Dot inversionFlicker_Dot InversionFrame inversionDot inversion混淆視覺用Worst Driving Condition Sub-pixel CheckerSub-pixel Checker(Window shot down pattern)Dot I