液晶顯示器驅動系統.ppt

液晶顯示器驅動系統,課程大綱液晶物質簡介液晶的電光效應液晶基本驅動原理STNLCDs驅動原理TFTLCDs驅動原理影響TFTLCDs畫面品質的因素DriverIC簡介TFTLCDs模組及介面技術簡介,液晶物質的相變化,固體結晶,液晶,液體,加熱,加熱,冷卻,冷卻,液晶分子的種類,液晶分子的排列,Crystalline,LiquidCrystalline,Liquid,KSmCSmANL,Biaxial,Unaxial,Isotropic,Temperature,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,OpticalPositive,OpticalNegative,HelicalAxisOpticalAxis,OpticalAxis,液晶驅動原理,電極,電極,液晶,FieldOFF,FieldON,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(PolymerStabilizedCholestericTexture)1993OtherDS(DynamicScattering)1968PC(PhaseChange)1968GH(GuestHost)1968ECB(ElcetricalControlBirefregency)1971BTN(BistableTwistNematic)1995IPS(InPlaneSwitch)1995VA(VerticalAlignment)1996,TN型LCDs顯示原理,液晶分子,FieldOFF,FieldON,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,液晶分子,FieldOFF,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-TCurve,100%,90%,10%,VnsSTN,VsSTN,VsTN,VnsTN,T,V,TN與STN的電壓漂移,T,100%,V,STNMode,LCDs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(ActiveMatrixAddressing)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,Vsig,Vc,Vs,Vc-Vs,ON,OFF,多工驅動法(振幅選擇驅動法,APT),多工驅動法的限制,APT驅動波形,IAPT驅動波形,APTAddressing,IAPTAddressing,APT與IAPT方式比較,APTAddressingLowVoltageSegmentDriver:2DHighVoltageCommonDriver:2FIAPTAddressingOffset+DforPositivePolarityOffset+FforNegativePolarityVoltageRangeofSegmentDriver:F+DVoltageRangeofCommonDriver:F+D,高容量多工驅動的對策,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:23.68V,STNLCDsDrivers架構,.移位暫存器(ShifterRegister),DCLK,串列輸入訊號,.閂鎖暫存器(LatchRegister),LP,F+D,0,F-D,2D,偏,壓,位,準,.,.,DF,(HLHL.H),.,H,L,H,H,並列輸出,垂直訊號電極,2D,0,2D,2D,IAPT參考電壓,IAPT驅動IC,灰階顯示FRC,FrameRateControl,FRC:,灰階顯示PWM,PulseWidthModulation,PWM:,灰階顯示PHM,PulseHighModulation,PHM:,液晶的頻率響應,VerticalCrosstalkofSTNLCDs,VerticalCrosstalk的抑制(一),每兩條水平線變換一次驅動電壓極性,VerticalCrosstalk的抑制(二),採用補償驅動週期,VerticalCrosstalk的抑制(三),一條水平掃描線的掃描週期分割成兩部份，一半的掃描時間是採用正極性的驅動訊號，另一半的時間是採用負極性的驅動訊號。,HorizontalCrosstalkofSTNLCDs,A,B,A,B,HorizontalCrosstalk的抑制,A,B,FrameResponseofSTNLCDs,ActiveAddressingforSTNLCDs,ActiveAddressing驅動電壓,IfVoff=2V,N=240rows,Then:F=0.730X2V=1.460V|G|=0.954X2V=21.909VOutputRangeofSegmentDriverisabout44V.CommonDriverofCommonDriverisabout3V.,SegmentVoltageofActiveAddressing,ActiveAddressing的矩陣運算,列向量（Column）,時間（Time）,行向量（Row）,Bit-MapImageMatrix,RowFunctionMatrix,時間（Time）,列（Column）,ColumnVoltageMatrix,矩陣運算方式,行（Row）,行向量（Row）,列向量（Column）,Bit-MapImageMatrix,RowVector,時間（Time）,列（Column）,Time=Dtk,行向量（Row）,列向量（Column）,第j列,RowFunctionMatrix,時間（Time）,列（Column）,ColumnVector,垂直序列運算ColumnSequential,時間序列運算TimeSequential,ColumnSequential硬體架構,TimeSequential硬體架構,主動矩陣式液晶顯示器AM-LCDs,TFTLCDs等效電路,RowDrivers,ColumnDriver,ArrangementofColorFilter,Stripe,Triangle,PixelStructureofTFTLCDs,CsonCommon與CsonGate架構,TimingChartofTFTLCDs,FrameTime,Gate123N,Time,TFTLCDsDrivingMethod,ColumnInversion,DotInversion,RowInversion,FrameInversion,DirectDrivingofTFTLCDs,DCBiasofCommon,GrayScaleVoltage,ACModulationAddressingofTFTLCDs,CommonWaveform,GraylevelVoltage,1Frame/1Line,TFTLCDs的電光效應DirectAddressing,TFTLCDs的電光效應ACAddressing,TFTLCDsDrivingWaveformCsonCommon(一),TFTLCD驅動波形(CsonCommon,Common=DCBias),TFTLCDsDrivingWaveformCsonCommon(二),TFTLCDsDrivingWaveformCsonGate,TFT電容效應的影響,液晶電容的效應,液晶電容CLC會隨液晶作用電壓的改變而變化，因此在驅動液晶時會有殘存的DC成份，其所造成的影響：ImageSticking.PictureFlicker.液晶作用電壓大時，液晶分子趨向平行電場方向排列：液晶作用電場小時，液晶分子趨向垂直電場方向排列：,二階驅動方式的效應,Cs,Clc,Cgd,Csd,Cgs,Vct,Ch(N-1),Ch(N),Vs,垂直影像訊號,水平掃描訊號,Vg,水平掃描訊號,Vg,TFT補償驅動法,3LevelAddressing,4LevelAddressing,3LevelAddressing,4LevelAddressing,Vst=Vct,B(+),B(-),B(-),B(+),W(+),W(+),W(-),W(-),B(+),W(-),B(-),W(+),Vp(+),Vp(-),Vp=CgdVghl/Ct,CsVge(-)/Ct,CsVge(+)/Ct,正極性,負極性,正極性,負極性,Ct=Cs+Clc+Cgd,CsonGate電壓補償方式,ComparsionofAddressingMethod,HorizontalLineCrosstalk,A,B,Csc,Csc,Csc,TFTSubstrate,ColorFilterSubstrate,HorizontalAreaCrosstalk,A,B,VerticalAreaCrosstalk,ShadingCrosstalk,ShadingCrosstalk的抑制,GatePulse的傳遞延遲,Gate(Scan)Line的等效阻抗為一連串的串聯RC網路，因此GatePulse在傳遞時會造成波形的傳遞延遲失真。,液晶畫素邊際電場效應(一),ReverseTilt,畫素電極,鄰近電極,共通電極,VP,VL,VA,VAVL:DisclinationDisappearedVPLCThresholdVoltage,ReverseTilt,液晶畫素邊際電場效應(二),改善方法1.增加液晶分子的預傾角(PretiltAngle)2.增加BlackMask的遮蔽面積,驅動ICScanDriver,BidirectionalShiftRegister,LevelShiftCircuit,OutputBuffer,G1G2G3.,STVR,STVL,CPV,R/L,VDDD,VSSD,VDDA,VSSA,STVR,STVL,G1,G2,Gx,SerialInSerialOutAnalogDataDriver,Multiplexer,Pro:Verysimple.Fewerexternalconnections.Con:Manyanaloginputs.Reducedpixelchargingtime.SystemNote:Sampleclock:(Dotclock)/N,NPhases.VideoPhase:N,VariationonMultiplexerPro:VideoInput.Con:Fastdatalinechargingneeded.Reducedpixelchargingtime.SystemNote:ShiftClock:(DotClock)/3forMono.VideoPhase:3forMono.,SampleandHold,SerialInParallelOutAnalogDataDriver(一),SerialInParallelOutAnalogDataDriver(二),DoubleSampleandHold/Multi-Phase,Por:Reducedoperationfrequency.SystemNote:VideoIn:NVideoPhase:NShiftClock:(DotClock)/N.,DigitalDataDriver(一),Digital-to-analogConverters,Por:Digitalinput.Con:Complex.RequiressufficientprecisiontocorrectforLCresponsevariation.,RampIn,SampledRamp,Por:Digitalinput.Programmableramp.Con:Complexcircuit.Highspeeddigitalcircuits.Reducedpixelchargingtime.,DigitalDataDriver(二),1-of-nSelector,SimpleDACPro:Digitalinput.Programmableexternalvoltages.Con:Complexcircuit.Highspeeddigitalcircuits.Manypassgatesperdataline.,DigitalDataDriver(三),AllDigitalCircuit,GammaCorrectionofLCD,AnalogCorrection:23SegmentApproach.DigitalCorrection:Externalfixedvoltage.,GammaCorrectionSimpleCase,Transmission,Voltage,TheBlockDiagramoftheTFTLCDModule,TheTFTLCDModuleType,ClassifiedintotwokindsbydatadriverAnalogtypeTFT-LCDmoduleTheanalogdatadriversTheanaloginterfacetoPCOnlyNECDigitaltypeTFT-LCDmoduleThedigitaldatadriversTheADC/LVDS/PanelLinkinterfacetoPCMainstream,TheAnalogInterface,TheADCInterface,TheLVDS/PanelLinkInterface,Analog/ADC/LVDS/PanelLink,AnalogInterfaceTrueColorSamplingErrorLowEdgeSharpnessNoiseintheAnalogSignalTransmission,Analog/ADC/LVDS/PanelLink,ADCInterfaceMainstreamintheDesktopLCDMonitorInterfaceSamplingErrorLowEdgeSharpnessNoiseintheAnalogSignalTransmissionEMIIssueforHighResolutionFormatLowImageQualityandHighCost,Analog/ADC/LVDS/PanelLink,LVDSInterfaceMainstreamintheNotebookPCInterfaceHighEdgeSharpnessReducingEMI&Numberof