液晶显示器驱动方式复习过程.ppt

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1、液晶显示器驱动方式液晶分子的排列CrystallineLiquidCrystallineLiquidKSmCSmANLBiaxialUnaxialIsotropicTemperature液晶的分類液晶的電光特性異向性(Anisotropic)排列因數()折射率()黏滯係數()介電係數()電導係數磁化率彈性係數()液晶的光學特性OpticalPositiveOpticalNegativeHelicalAxisOpticalAxisOpticalAxis液晶驅動原理電極電極液晶FieldOFFFieldON液晶顯示器主要優缺點優點低電壓驅動。低消耗電流。體積薄，重

2、量輕。可實現大面積化。彩色化容易。缺點視角限制。外加被光源或投射光源。溫度操作範圍限制。液晶顯示器的種類液晶顯示器扭轉型(TwinstNematic,TN)1971超扭轉型(SuperTwinstNematic,STN)1984雙層雙扭轉型(DoubleLayerSTN,DSTN)1987光相位補償超扭轉型(FilmSTN,FSTN)1988主動驅動超扭轉型(AASTNorMLSSTN)1992強介電型(FerroelectricLiquidCrystal:FLC)1980PDLC(PolymerDispersiveLC)1988PSCT(PolymerSta

3、bilizedCholestericTexture)1993OtherDS(DynamicScattering)1968PC(PhaseChange)1968GH(GuestHost)1968ECB(ElcetricalControlBirefregency)1971BTN(BistableTwistNematic)1995IPS(InPlaneSwitch)1995VA(VerticalAlignment)1996TN型LCDs顯示原理Twist90液晶分子FieldOFFFieldON利用液晶的旋光特性調變穿透光線液晶的旋光特性消失STNLCDs顯示原理T

4、wist270液晶分子FieldOFFFieldON利用液晶的雙折射特性調變穿透光線TN&STN電光轉移曲線V-TCurve100%90%10%VnsSTNVsSTNVsTNVnsTNTVTN與STN的電壓漂移T100%VTNModeT100%VSTNModeLCDs驅動方式直接驅動法(DirectionAddressing)靜態驅動法(StaticAddressing)多工驅動法(MultiplexAddressing)主動驅動法(ActiveAddressing/Multi-LineSelection)主動矩陣驅動法(ActiveMatrixAddres

5、sing)兩端元件(MIM,Diode..)三端元件(A-Si:HTFT,Ploy-SiTFT..)PlasmaAddressing(PALC)熱掃描驅動法(雷射掃描)光掃描驅動法(電子速掃描LCDs靜態驅動法LCCellXORVsVcVsigVcVsigVcVsVc-VsONOFF多工驅動法(振幅選擇驅動法,APT)1234N123Frame1Frame2F0DT水平掃描訊號+D-D0垂直影像訊號Row1Row2Row3RowNColumn1ONOFFONOFFF+DF-DF+DF-D+D-D0+D-D0+D-D0+D-D01234NFrame1液晶畫素電

6、壓T多工驅動法的限制1.01.11.21.3100200APT驅動波形IAPT驅動波形APTAddressingIAPTAddressingAPT與IAPT方式比較APTAddressingLowVoltageSegmentDriver:2DHighVoltageCommonDriver:2FIAPTAddressingOffset+DforPositivePolarityOffset+FforNegativePolarityVoltageRangeofSegmentDriver:F+DVoltageRangeofCommonDriver:F+D高容量多工驅動

7、的對策(a)(b)(c)(d)(e)STNLCDs規格OperationVoltageVop:BiasRatio:Steepness:SelectionRatio:STNLCDs驅動電壓計算IfVoff=2V,N=240rows,Then:APT:SegmentDriver:2.96V,CommonDriver:44.40VIAPT:Segment&CommonDrivers:23.68VSTNLCDsDrivers架構......移位暫存器(ShifterRegister)DCLK串列輸入訊號...閂鎖暫存器(LatchRegister)LPF+D0F-D2

8、D偏壓位準..............