TFT-LCD工作原理-谢崇凯(最全版本)LCD驱动必看

FPDTFTLCDFPDisplay2004.8(CRT,cathode-raytube).,.,,..Thin-filmtransistorliquidcrystaldisplay,TFTLCD.,,,..3(LC,liquidcrystal),.,,.,,(1),,,.,.1888,FriedrichReinitzer,(cholesterylbenzoate),145.5,,.178.5,(isotropicliquid).,1889,O.Lehmann,.,,(birefringence),(opticalanisotropic)..,,-(liquidcrystal).,.,,,.(2),,,.,()..,,.,,.1922G.Friedel,NematicSmecticCholesteric.(3),:4度度(Crystalline)SematicCphaseSematicAphaseNematicphase(Liquid)(Liquidcrystalline)(biaxial)(uniaxial)(Isotropic)(Anisotropic)6(Sematic)X(Cholesteric)XZY()(Disk,Discoid)X(Nematic)XZY(Director)7(LC,liquidcrystal)1.(Sematic):,...,.S(orderparameter)1.,.,.,.,(director),.,,.,SematicAphase.(tilt),SematicCphase.A,C,,,SematicBphase.BphaseCphase,CphasechiralBphase.ChiralsematicCphaseSematicBphase(4).,,.2.(Nematic):Nematic,thread.,.,()..,S.,()TFTTN(Twistednematic).8(LC,liquidcrystal)3.(cholesteric):,..5,,.Z,,360pitch.,Chiralnematicphase.,,,,.4.(disk):,,(disk),(discoid).(polymerliquidcrystal,).TFT.,(thermotropic),(lyotropic).,,.,.,,,,,.(anisotropic).,.,.,,,.10(Cholesteric)XZY(Director)Pitch,XY,.pitch,360.11(Anisotropic),,.,,:1.(dielectricpermittivity):,(.2.(refractiveindex):,,.n//n.(uniaxial),.no,ordinaryray,no.ordinaryray.ne,extraordinaryray,extraordinaryray.(birefrigence)n=ne-no.12(=ne)n//(=no),()ne-no0.n0,,.,n0...3.:,,.(elasticconstant:(viscositycoefficients,),(responsetime),..(magneticsusceptibility),,χ//χ.χ=χ//-χ.13•Parameterdefinene=nextraordinary=nparallel=n//no=nordinary=nperpendicular=n⊥•Opticalanisotropy•Birefringence∆n=n//-n⊥•Positivebirefringence:nenonone14(polarizer),,,.,.,.,.(),,.,,.,.,,.,.(8).,,,,,,.(9)16(polarizer)17(polarizer)18(TwistNematic)LCD19(Thinfilmtransistor,TFT),(Colorfilter).(3),,,.,.,.,,,.,,,.,,PI(polyimide),(rubbing),PI,.PI,3,,.20(TwistedNematic)LCD10,,.TN,90.(9)90,,.,90,,90.,90.(9),,TN,,.21(TwistNematic)LCD不22(Normallywhite),,,,normallywhite.,,,,NB(Normallyblack).910NW,11,TNLCD,,NBNW.NB,.NB,90.NWNB?.,NW.,,,.,NW.NW,.NB.23(SuperTwistedNematic)LCDSTNLCDTNLCD,TNLCD,,90.STNLCD,180,270.(12),.13TNSTNLCD,,.,.NormalWhite.,TNLCD,STNLCD.TNLCD,90%10%,STNLCD.,,.TNSTN,TNLCD,STNLCD.TNLCD6~8bits,64~256.STNLCD4bits16.STNTNLCD(responsetime)STNLCD100msTNLCD30~50msSTNLCD25(supertwistnematic)LCDTNLCD=90STNLCD180(270)26(Thinfilmtransistorliquidcrystaldisplay)TFTLCD,.,,TFTLCD.14,,,,CLC(capacitorofliquidcrystal).0.1pF,,.TFT,,TFT.(60Hz,16ms.),,.,CS(storagecapacitor0.5pF),.,TFT,.LCDsourcedriver.,.LCDsourcedriver.28(colorfilter,CF),,.15.,,.,..RGB,,,RGB,,pixel.pixel,.1024*768,1024*768pixel,.15,RGB,Blackmatrix.14,blackmatrix.ITO,Cr/Al,TFT.15,RGB,,blackmatrix,TFT.16.(stripe)OA,,.?,.,,.,,,,.AV,.,,.,AV(mosaic,).AV,(triangle,delta).,,.,pixel,pixel..30:RRRGGGBBBRRRGGGBBBRGBRGBRGBRGBRGBRGBRGBRGBRGBRGBRGBRBRGBRGBRGBRBRGRGBBGGRGRGBBGGRGRGBBWWRGRGBBWW32(backlight,BL)CRT,,,,.,,.,,,.14,(),,,prismsheet,.,,.TFTLCD.prismsheet,,TFTLCD.TFTLCD,,.33(Sealant)spacer14spacer.,,,,,,.spacer,,spacer,,(gap),,.34(Apertureratio),.?.17,17.,,LCDsourcegate,TFT,.,,,blackmatrix,.,17.,.,,,,.::50%():95%():95%:50%():27%(80%,,.RGB,..80%*33%=27%.),6%,.TFTLCD,.,,,.35!TFTLCD液晶显示器的驱动原理(一)副标题:前两次跟大家介绍有关液晶显示器操作的基本原理,那是针对液晶本身的特性,与TFTLCD本身结构上的操作原理来做介绍.这次我们针对TFTLCD的整体系统面来做介绍,也就是对其驱动原理来做介绍,而其驱动原理仍然因为一些架构上差异的关系,而有所不同.首先我们来介绍由于Cs(storagecapacitor)储存电容架构不同,所形成不同驱动系统架构的原理.Cs(storagecapacitor)储存电容的架构一般昀常见的储存电容架构有两种,分别是Csongate与Csoncommon这两种.这两种顾名思义就可以知道,它的主要差别就在于储存电容是利用gate走线或是common走线来完成的.在上一篇文章中,我曾提到,储存电容主要是为了让充好电的电压,能保持到下一次更新画面的时候之用.所以我们就必须像在CMOS的制程之中,利用不同层的走线,来形成平行板电容.而在TFTLCD的制程之中,则是利用显示电极与gate走线或是common走线,所形成的平行板电容,来制作出储存电容Cs.图1就是这两种储存电容架构,从图中我们可以很明显的知道,Csongate由于不必像Csoncommon一样,需要增加一条额外的common走线,所以它的开口率(Apertureratio)会比较大.而开口率的大小,是影响面板的亮度与设计的重要因素.所以现今面板的设计大多使用Csongate的方式.但是由于Csongate的方式,它的储存电容是由下一条的gate走线与显示电极之间形成的.(请见图2的Csongate与Csoncommon的等效电路)而gate走线,顾名思义就是接到每一个TFT的gate端的走线,主要就是作为gatedriver送出信号,来打开TFT,好让TFT对显示电极作充放电的动作.所以当下一条gate走线,送出电压要打开下一个TFT时,便会影响到储存电容上储存电压的大小.不过由于下一条gate走线打开到关闭的时间很短,(以1024*768分辨率,60Hz更新频率的面板来说.一条gate走线打开的时间约为20us,