[信息与通信]液晶显示器驱动系统课件.ppt

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1、液晶顯示器驅動系統講師:陳建斌 楊和興 王清桐 王智偉課程大綱 液晶物質簡介 液晶的電光效應 液晶基本驅動原理 STN LCDs 驅動原理 TFT LCDs 驅動原理 影響TFT LCDs 畫面品質的因素 Driver IC 簡介 TFT LCDs 模組及介面技術簡介2023/6/2 1 Write by Wang C.W.液晶物質的相變化固體結晶 液晶 液體加熱 加熱冷卻 冷卻2023/6/2 2 Write by Wang C.W.液晶分子的種類Smectic LC 層狀液晶Nematic LC 線狀液晶Cholesteric LC膽固醇狀液晶2023/6/2 3 Write by Wan

2、g C.W.液晶分子的排列Crystalline Liquid CrystallineLiquid K SmC SmA N LBiaxial Unaxial IsotropicTemperature2023/6/2 4 Write by Wang C.W.液晶的分類2023/6/2 5 Write by Wang C.W.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()2023/6/2 6 Write by Wang C.W.液晶的光學特性Optical Positive Optical NegativeHelical

3、 AxisOptical AxisOptical Axis2023/6/2 7 Write by Wang C.W.液晶驅動原理電極電極液晶Field OFF Field ON2023/6/2 8 Write by Wang C.W.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。2023/6/2 9 Write by Wang C.W.液晶顯示器的種類 液晶顯示器扭轉型(Twinst Nematic,TN)1971超扭轉型(Super Twinst Nematic,STN)1984 雙層雙

4、扭轉型(Double Layer STN,DSTN)1987 光相位補償超扭轉型(Film STN,FSTN)1988 主動驅動超扭轉型(AASTN or MLS STN)1992強介電型(Ferroelectric Liquid Crystal:FLC)1980PDLC(Polymer Dispersive LC)1988 PSCT(Polymer Stabilized Cholesteric Texture)1993Other DS(Dynamic Scattering)1968 PC(Phase Change)1968 GH(Guest Host)1968 ECB(Elcetrical

5、Control Birefregency)1971BTN(Bistable Twist Nematic)1995IPS(In Plane Switch)1995V A(Vertical Alignment)19962023/6/2 10 Write by Wang C.W.TN 型 LCDs 顯示原理Twist 90液晶分子Field OFF Field ON利用液晶的旋光特性調變穿透光線液晶的旋光特性消失2023/6/2 11 Write by Wang C.W.STN LCDs 顯示原理Twist 270液晶分子Field OFFField ON利用液晶的雙折射特性調變穿透光線2023/6

6、/2 12 Write by Wang C.W.TN&STN 電光轉移曲線V-T Curve100%90%10%VnsSTN VsSTNVsTNVnsTNTV2023/6/2 13 Write by Wang C.W.TN 與 STN 的電壓漂移T100%VTN ModeT100%VSTN Mode2023/6/2 14 Write by Wang C.W.LCDs 驅動方式直接驅動法(Direction Addressing)靜態驅動法(Static Addressing)多工驅動法(Multiplex Addressing)主動驅動法(Active Addressing/Multi-Lin

7、e Selection)主動矩陣驅動法(Active Matrix Addressing)兩端元件(MIM,Diode.)三端元件(A-Si:H TFT,Ploy-Si TFT.)Plasma Addressing(PALC)熱掃描驅動法(雷射掃描)光掃描驅動法(電子速掃描2023/6/2 15 Write by Wang C.W.LCDs 靜態驅動法LC CellXORVsVcVsigVcVsigVcVsVc-VsONOFF2023/6/2 16 Write by Wang C.W.多工驅動法(振幅選擇驅動法,APT)1 2 3 4 N 1 2 3Frame 1 Frame 2F0DT水平掃

8、描訊號+D-D0垂直影像訊號Row 1Row 2Row 3Row NColumn 1ONOFFONOFFF+DF-DF+DF-D+D-D0+D-D0+D-D0+D-D01 2 3 4 NFrame 1液晶畫素電壓T2023/6/2 17 Write by Wang C.W.多工驅動法的限制1.01.11.21.31002002023/6/2 18 Write by Wang C.W.APT 驅動波形2023/6/2 19 Write by Wang C.W.IAPT 驅動波形APT Addressing IAPT Addressing2023/6/2 20 Write by Wang C.W.

9、APT 與 IAPT 方式比較 APT Addressing Low V oltage Segment Driver:2D High V oltage Common Driver:2F IAPT Addressing Offset+D for Positive Polarity Offset+F for Negative Polarity V oltage Range of Segment Driver:F+D V oltage Range of Common Driver:F+D2023/6/2 21 Write by Wang C.W.高容量多工驅動的對策(a)(b)(c)(d)(e)20

10、23/6/2 22 Write by Wang C.W.STN LCDs 規格Operation V oltage V op:Bias Ratio:Steepness:Selection Ratio:2023/6/2 23 Write by Wang C.W.STN LCDs 驅動電壓計算If V off=2V,N=240 rows,Then:APT:Segment Driver:2.96V,Common Driver:44.40VIAPT:Segment&Common Drivers:23.68V2023/6/2 24 Write by Wang C.W.STN LCDs Drivers 架

11、構.移位暫存器(Shifter Register)DCLK串列輸入訊號.閂鎖暫存器(Latch Register)LPF+D 0F-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 2DIAPT 參考電壓IAPT 驅動 IC2023/6/2 25 Write by Wang C.W.灰階顯示 FRCFrame Rate Control,FRC:2023/6/2 26 Write by Wang C.W.灰階顯示 PWMPulse Width Modulation,PWM:2023/6/2 27 Write by Wang C.W.灰階顯示 PHMPuls

12、e High Modulation,PHM:2023/6/2 28 Write by Wang C.W.液晶的頻率響應2023/6/2 29 Write by Wang C.W.Vertical Crosstalk of STN LCDs2023/6/2 30 Write by Wang C.W.Vertical Crosstalk 的抑制(一)每兩條水平線變換一次驅動電壓極性2023/6/2 31 Write by Wang C.W.Vertical Crosstalk 的抑制(二)採用補償驅動週期2023/6/2 32 Write by Wang C.W.Vertical Crosstal

13、k 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。2023/6/2 33 Write by Wang C.W.Horizontal Crosstalk of STN LCDs垂直驅動訊號L Line水平掃描波形液晶畫素波形(a)(b)(c)(d)A B A BL2023/6/2 34 Write by Wang C.W.Horizontal Crosstalk 的抑制垂直驅動訊號L Line水平掃描波形液晶畫素波形(a)(b)(c)(d)傳統驅動方式水平掃描補償波形補償之液晶畫素波形(e)(f)GVLA B2023/

14、6/2 35 Write by Wang C.W.Frame Response of STN LCDs2023/6/2 36 Write by Wang C.W.Active Addressing for STN LCDs2023/6/2 37 Write by Wang C.W.Active Addressing 驅動電壓If Voff=2V,N=240 rows,Then:F=0.730 X 2V=1.460V|G|=0.954 X 2V=21.909VOutput Range of Segment Driver is about 44V.Common Driver of Common D

15、river is about 3V.2023/6/2 38 Write by Wang C.W.Segment V oltage of Active Addressing2023/6/2 39 Write by Wang C.W.Active Addressing 的矩陣運算列向量（Column）時間（Time）行向量（Row）Bit-Map Image MatrixRow Function Matrix時間（Time）列（Column）Column V oltage Matrix2023/6/2 40 Write by Wang C.W.矩陣運算方式行（Row）行向量（Row）列向量（Col

16、umn）Bit-Map Image MatrixRow Vector時間（Time）列（Column）Time=Dtk 行向量（Row）列向量（Column）第j列Row Function Matrix時間（Time）列（Column）Column Vector垂直序列運算Column Sequential時間序列運算Time Sequential2023/6/2 41 Write by Wang C.W.Column Sequential 硬體架構 NM圖框記憶體 NM圖框記憶體影像資訊 輸入IjNXOR陣列N加法邏輯陣列NM STN LCDs液晶層間隙4.5um液晶材料：低黏滯係數水平驅動

17、函數唯讀記憶體Row Function ROMNSTN LCDs垂直驅動晶片TFT LCDs 垂直驅動晶片1轉2多工器2轉1解多工器2023/6/2 42 Write by Wang C.W.Time Sequential 硬體架構 NM圖框記憶體 NM圖框記憶體影像資訊 輸入IjNXOR陣列N加法邏輯陣列水平驅動函數唯讀記憶體Row Function ROMN1轉2多工器2轉1解多工器NM圖框緩衝記憶體NM圖框緩衝記憶體NM STN LCDs液晶層間隙4.5um液晶材料：低黏滯係數STN LCDs垂直驅動晶片TFT LCDs 垂直驅動晶片N2023/6/2 43 Write by Wang

18、C.W.主動矩陣式液晶顯示器AM-LCDs2023/6/2 44 Write by Wang C.W.TFT LCDs 等效電路Row DriversColumn Driver2023/6/2 45 Write by Wang C.W.Arrangement of Color Filter R G B R G BR G B R G BR G B R G BR B G RG B RBGR B G RG B RBGR B G RG B RBGR GG BR GG BR GG BR GG BR GW BR GW BR GW BR GW BStripe Triangle 2023/6/2 46 Wri

19、te by Wang C.W.Pixel Structure of TFT LCDs2023/6/2 47 Write by Wang C.W.Cs on Common 與 Cs on Gate 架構液晶畫素TFTGate LineData LineCsCs液晶畫素TFTCommonCommonGate LineData LineCsCs Cs on CommonCs on Gate2023/6/2 48 Write by Wang C.W.Timing Chart of TFT LCDsFrame TimeGate123NTime2023/6/2 49 Write by Wang C.W.T

20、FT LCDs Driving MethodColumn Inversion Dot InversionRow Inversion Frame Inversion2023/6/2 50 Write by Wang C.W.Direct Driving of TFT LCDs DC Bias of CommonGrayScale V oltage V0V1V2V3V4V5V6V7V7V6V5V4V3V2V1V01 Frame/1 Line2023/6/2 51 Write by Wang C.W.AC Modulation Addressing of TFT LCDsV0V1V2V3V4V5V6

21、V7V7V6V5V4V3V2V1V0Common WaveformGraylevel V oltage1Frame/1 Line2023/6/2 52 Write by Wang C.W.TFT LCDs 的電光效應Direct Addressing2023/6/2 53 Write by Wang C.W.TFT LCDs 的電光效應AC Addressing2023/6/2 54 Write by Wang C.W.TFT LCDs Driving Waveform Cs on Common(一)TFT LCD 驅動波形(Cs on Common,Common=DC Bias)2023/6

22、/2 55 Write by Wang C.W.TFT LCDs Driving Waveform Cs on Common(二)2023/6/2 56 Write by Wang C.W.TFT LCDs Driving Waveform Cs on Gate 2023/6/2 57 Write by Wang C.W.TFT 電容效應的影響PixelCgdCgsCsdCsdb Csdb2023/6/2 58 Write by Wang C.W.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：Image Sticking

23、.Picture Flicker.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：2023/6/2 59 Write by Wang C.W.二階驅動方式的效應Cs ClcCgdCsdCgsVctCh(N-1)Ch(N)Vs 垂直影像訊號水平掃描訊號Vg水平掃描訊號VgVshVslVstVthVth正極性驅動負極性驅動負極性驅動正極性驅動資料驅動晶片輸出訊號電位液晶畫素電位Vct=Vst-VpVpBlack(+)White(+)White(+)Black(+)Black(-)Black(-)White(-)White(-)2023/6/2 60

24、Write by Wang C.W.TFT 補償驅動法Ch(N-1)Ch(N)Vst=Vct影像訊號波形 Vs水平脈波掃描波形VgeVgeVghlCh(N-1)Ch(N)Vst影像訊號波形VsVge(+)Vge(-)VghlVghl3 Level Addressing4 Level Addressing2023/6/2 61 Write by Wang C.W.3 Level AddressingB(+)W(-)B(-)W(+)正極性負極性Vst=VctB(+)B(-)W(+)W(-)B(+)W(-)B(-)W(+)Vp=CgdVghl/Ct正極性負極性正極性Ct=Cs+Clc+Cgd負極性C

25、sVge/CtCsVge/Ct2023/6/2 62 Write by Wang C.W.4 Level AddressingVst=VctB(+)B(-)B(-)B(+)W(+)W(+)W(-)W(-)B(+)W(-)B(-)W(+)Vp(+)Vp(-)Vp=CgdVghl/CtCsVge(-)/CtCsVge(+)/Ct正極性負極性正極性負極性Ct=Cs+Clc+Cgd2023/6/2 63 Write by Wang C.W.Cs on Gate 電壓補償方式經由 Cs 將前一條水平脈波的補償波形耦合到動作的液晶畫素,補償 Cgd 造成的電壓漂移及改善液晶畫素內的直流電電壓殘餘.經由 T

26、FT 的 Cgd 造成的電壓漂移經由 TFT 的 Cgd 造成的電壓漂移2023/6/2 64 Write by Wang C.W.Comparsion of Addressing Method2023/6/2 65 Write by Wang C.W.Horizontal Line CrosstalkA BCsc Csc CscTFT SubstrateColor Filter Substrate2023/6/2 66 Write by Wang C.W.Horizontal Area CrosstalkA B2023/6/2 67 Write by Wang C.W.Vertical Ar

27、ea CrosstalkUpLowUpLow2023/6/2 68 Write by Wang C.W.Shading Crosstalk2023/6/2 69 Write by Wang C.W.Shading Crosstalk 的抑制2023/6/2 70 Write by Wang C.W.Gate Pulse 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 Gate Pulse 在傳遞時會造成波形的傳遞延遲失真。RCRCRCRCN2023/6/2 71 Write by Wang C.W.液晶畫素邊際電場效應(一)Reverse Tilt畫素電極

28、鄰近電極共通電極VPVLVAVA VL:Disclination DisappearedVP LC Threshold V oltageReverse Tilt 2023/6/2 72 Write by Wang C.W.液晶畫素邊際電場效應(二)TFT水平驅動電極垂直驅動電極RubbingDirectionDisclinationLineReverse TiltDomain改善方法1.增加液晶分子的 預傾角(Pretilt Angle)2.增加 Black Mask 的 遮蔽面積2023/6/2 73 Write by Wang C.W.驅動 IC Scan DriverBidirectio

29、nal Shift RegisterLevel Shift CircuitOutput BufferG1 G2 G3.STVR STVLCPVR/LVDDDVSSDVDDAVSSASTVRSTVLG1G2Gx2023/6/2 74 Write by Wang C.W.Serial In Serial Out Analog Data DriverSelectData j Data j+1MultiplexerPro:Very simple.Fewer external connections.Con:Many analog inputs.Reduced pixel charging time.S

30、ystem Note:Sample clock:(Dot clock)/N,N Phases.Video Phase:NShift RegisterVideo InQiQi+1Variation on MultiplexerPro:Video Input.Con:Fast data line charging needed.Reduced pixel charging time.System Note:Shift Clock:(Dot Clock)/3 for Mono.Video Phase:3 for Mono.Sample and Hold2023/6/2 75 Write by Wan

31、g C.W.Serial In Parallel OutAnalog Data Driver(一)Shift RegisterQi Qi+1 Qi+2 Qi+3Video InTransferDouble Sample and Hold/Single PhaseSample N Sample N+1 Sample N+2 T T TN N+1 N+2Out N-1 Out N Out N+1Pro:Video Input.Small load on fast sample-and-holds.Full line time to charge pixel.Con:Complex analog c

32、ircuit.Physical size.System Note:Shift Clock:Dot Clock.Video Phase:Single Phase.2023/6/2 76 Write by Wang C.W.Serial In Parallel OutAnalog Data Driver(二)Shift RegisterQi Qi+1Video InTransferDouble Sample and Hold/Multi-PhasePor:Reduced operation frequency.System Note:Video In:NVideo Phase:NShift Clo

33、ck:(Dot Clock)/N.2023/6/2 77 Write by Wang C.W.Digital Data Driver(一)Shift RegisterDAC DAC DAC DAC DAC Serial Data BusDigital-to-analog ConvertersPor:Digital input.Con:Complex.Requires sufficient precision to correct for LC response variation.Shift RegisterCount Count Count Count CountRamp InSampled

34、 RampPor:Digital input.Programmable ramp.Con:Complex circuit.High speed digital circuits.Reduced pixel charging time.2023/6/2 78 Write by Wang C.W.Digital Data Driver(二)Shift RegisterDecode DecodeExternal Fixed voltages1-of-n SelectorSimple DACPro:Digital input.Programmable external voltages.Con:Com

35、plex circuit.High speed digital circuits.Many pass gates per data line.2023/6/2 79 Write by Wang C.W.Digital Data Driver(三)All Digital Circuit 2023/6/2 80 Write by Wang C.W.Gamma Correction of LCDXY取像元件取像電路 顯像電路顯像元件攝像機測受像機測Analog Correction:2 3 Segment Approach.Digital Correction:External fixed volt

36、age.2023/6/2 81 Write by Wang C.W.Gamma Correction Simple CaseXY取像元件取像電路顯像電路顯像元件攝像機測受像機測TransmissionV oltage2023/6/2 82 Write by Wang C.W.The Block Diagram of the TFT LCD ModuleCCFL BacklightTFT-LCDPANELTiming ControllerScan DriverData DriverRGBCLKHsxVsxTFTLCD Module2023/6/2 83 Write by Wang C.W.The

37、 TFT LCD Module Type Classified into two kinds by data driver Analog type TFT-LCD module The analog data drivers The analog interface to PC Only NEC Digital type TFT-LCD module The digital data drivers The ADC/LVDS/PanelLink interface to PC Mainstream2023/6/2 84 Write by Wang C.W.The Analog Interfac

38、eGraphicsControllerTFT-LCDPANELTiming ControllerScan DriverAnalog Data DriverHsVsAnalogRGBAnalogRGBCLKHsxVsxPreAmpLevelShifterControllerPLLPC Analog Module TFTLCD ModuleOSDCCFL Backlight2023/6/2 85 Write by Wang C.W.The ADC InterfaceGraphicsControllerTFT-LCDPANELTiming ControllerScan DriverDigital D

39、ata DriverHsVsAnalogRGBDigitalRGBCLKHsxVsxADC BufferControllerPLLPC ADC Module TFTLCD ModuleOSDCCFL Backlight2023/6/2 86 Write by Wang C.W.The LVDS/PanelLink InterfaceGraphicsControllerLVDS/PanelLinkTxLVDS/PanelLinkRxTFT-LCDPANELTiming ControllerScan DriverCABLEClockHsVsDigitalRGBDigitalRGBClockHsVs

40、PC TFT-LCD ModuleDigital Data DriverCCFL Backlight2023/6/2 87 Write by Wang C.W.Analog/ADC/LVDS/PanelLink Analog Interface True Color Sampling Error Low Edge Sharpness Noise in the Analog Signal Transmission2023/6/2 88 Write by Wang C.W.Analog/ADC/LVDS/PanelLink ADC Interface Mainstream in the Deskt

41、op LCD Monitor Interface Sampling Error Low Edge Sharpness Noise in the Analog Signal Transmission EMI Issue for High Resolution Format Low Image Quality and High Cost2023/6/2 89 Write by Wang C.W.Analog/ADC/LVDS/PanelLink LVDS Interface Mainstream in the Notebook PC Interface High Edge Sharpness Re

42、ducing EMI&Number of Cable Line High Image Quality and Low Cost Short Transmission Length&Low Noise Margin Compatible Issue2023/6/2 90 Write by Wang C.W.PanelLink Interface Application in the Desktop LCD Monitor Interface High Edge Sharpness Reducing EMI&Number of Cable Line High Image Quality and L

43、ow Cost Second Supply Source IssueAnalog/ADC/LVDS/PanelLink2023/6/2 91 Write by Wang C.W.TFT Module 設計考慮(一)顯示的影像訊號時序規格(Image Format)圖框重複率(Frame Rate)水平掃描線掃描時間 TFT 的 ION/IOFF 電流 水平掃描脈線的RC時間常數 灰階誤差 直流漂移2023/6/2 92 Write by Wang C.W.TFT Module 設計考慮(二)選擇適合的驅動方式(Cs on Gate or COM)選擇適合的極性轉換方式 驅動IC(Scan&So

44、urce)的選取 TFT LCDs 模組介面技術的選擇2023/6/2 93 Write by Wang C.W.大面積高解析度 TFT LCDs 的開口率影響因素大尺寸面積增加水平驅動電極阻值增加水平驅動波形的時間常數增加水平掃描線減少液晶畫素的有效充放電時間增加解析度增加 Cgd/CLC的比值增加 Vgd 增加 Reverse Tilt Domain 與畫素面積的比例增加 Black Matrix 的遮蔽面積降低畫面品質增加水平驅動電極的寬度增加 TFT 的尺寸增加儲存電容 CS 的面積降低開口率2023/6/2 94 Write by Wang C.W.Plasma Addressing

45、 LCDsCathode-200VAnode0-200Negative ClowPositive ColumnFaraday DarkCathodeAnode-200V VirtualConnectionSamplingCapacitorAnalogSignal2023/6/2 95 Write by Wang C.W.In-Plane-Switch Mode LCDs偏光版解偏版液晶分子作用電極玻璃基板入射光作用電場方向出射光之極化狀態 未加電場OFF 狀態 施加電場ON 狀態出射光2023/6/2 96 Write by Wang C.W.Vertical Alignment Mode L

46、CDs未加電場OFF 狀態施加電場ON 狀態入射光偏光板液晶分子玻璃基板出射光之極化狀態解偏板出射光2023/6/2 97 Write by Wang C.W.Comparison of Liquid Crystal ModesStrongly dependent on viewing angle低驅動電壓視角窄小Off(White)On(Black)Slightly dependent on viewing angle廣視角液晶反應速度慢Off(Black)On(White)畫面對比低畫面品質差Slightly dependent on viewing angle畫面對比高廣視角Off(Black)On(White)液晶反應速度快彩色畫面顯像佳TN IPS V A2023/6/2 98 Write by Wang C.W.