文献翻译——研究配色广色域 LED背光的LCD应用程序

第1页外文文献资料ResearchonColorMatchingofLEDBacklightforLarge-Color-GamutLCDApplicationComparingwiththeconventionalCCFL(ColdCathodeFluorescentLamp)backlight,three-basic-colorLEDsbacklighthassomeadvantagessuchasgoodcolorreproduction,longlifeandleadfreeetc.Theoretically,thecolorgamutisdeterminedbyx,ycoordinatesofthethreebasiccolorsinCIEchromaticitydiagram,andthex,ycoordinatesofeachbasiccolorcanderivedfromtherelativespectrumdistribution(RSD)oftheLED.Inthispaper,thered,greenandblueLEDsRSDmodelsareestablishedtocalculateandanalyzethecolorgamutofabacklight.Bysimulatingthosemodels,therelationshipsthatthecolorgamutofaLEDbacklightvarieswitheachcolorareanalyzed,andtheoptimumcombinationofthreecolorsisobtainedwithinthegivenwavelengthsranges.Moreover,thecombinationsofthreecolorsforthegamutof115%NTSCand110%NTSCareplottedinpictures,respectively.1.INTRODUCTIONIn1931CIEchromaticitydiagram,threepointscorrespondingtoRGBcolorsconstructatriangle,inwhichallcolorscanbereproducedbythethreebasiccolors.Areaofthatdeterminesthecolorgamut,andthewiderthecolorgamutis,themorecolorsthesystemcanreproduced.NTSCisoneofthebroadcastingstandardswhichweredefinedbasedonthecolorimetriccharacteristicsofCRTdisplay.InNTSC,standardilluminationCorD65isused,andthethree-basic-colorcoordinatesandthecolorgamutareshowedinFig1.ThecolorgamutofNTSCsystemwillbehereinaftertakentocomparewithcolorgamutofotherdisplaysystems.第2页Fig1.NTSC：colorgamutinchromaticitydiagramRecently,CCFLbacklightsstilloccupythedominantstatusintheareaofliquidcrystaldisplay,however,CCFLbacklightsarepoorcolorreproductionandtheircolorgamutonlyreachabout76%NTSC,andobviouslythisdrawbackismakingCCFLbacklightslosemoreandmoremarketofLCDbacklights.Ontheotherside,therapiddevelopmentofLEDoverthepassedfewyearshasopeneduptheopportunityforLEDbacklightstosubstituteforCCFLbacklightsinliquidcrystaldisplayindustryfortheiradvantageslikegoodcolorreproduction,longlifeandleadfreeetc.Thecolorgamutofadisplaycanbeenlargedbyusingsaturatedprimarycolors,andcolorsfromLEDsarehighlysaturatedbecauseFWHM(FullWaveatHaftMaximum)ofLEDsspectrumisnarrow.SodisplayswithLEDbacklightscanobtainawidecolorgamut,whichisusuallymorethan110%NTSC,andareabletofaithfullyreproducethebeautifulcolorsofreallife1-2.Inthispaper,weestablishthered,greenandblueLEDsRSDmodels.Basedonthemodels,thethree-colorRSDsaresimulatedbyretainingtheshapesandshiftingthepeakwavelengths.ThenthecolorgamutofalotofcombinationsofthreebasiccolorsiscalculatedandcomparedwiththecolorgamutofNTSC.Somegroupsofcombinationsofthreebasiccolorswhichcan第3页havewidecolorgamutmorethanacertainpercentofNTSCcolorgamutareobtained2.RSDMODELSESTABLISHEDAdisplayscolorgamutisdeterminedbyx,ycoordinatesofitsthreebasiccolors.Andwecanobtainx,ycoordinatesfromfollowingequations:)/(ZYXx（1）)/(y（2）WhereX,Y,ZarethetristimulusvalueswhichcorrespondtohumaneyesfeelingtoRGBcolorsrespectively.AndthetristimulusvaluescanbeobtainedbycalculatingtheintegralofRSDandspectraltristimulusvaluesfollowas:dxkX)(（3）ykY)(（4）dzkZ)(（5）Wherekisnormalizedfactor,（）istherelativespectrumdistribution,and,arespectraltristimulusvaluesofCIE)(xy)(zstandardobservers.Fromequations(1)-(5)above,weknowthatRSDsdeterminecolorschromaticitycoordinates,andsubsequentlyconfirmthecolorgamutofadisplaysystem.ThemainparameterswhichinfluencethedevicesRSDsarematerialandstructureetc.Approximately,wetake0.5,theFWHMofRSDs,asaconstant,whiledevicesmaterialandstructurearethesame.WhenthepeakwavelengthoandFWHM0.5areknown,theRSDofLEDcanbedescribedas3:第4页3/)(5exp2/)(exp)(25.05.0I(6)ThenwemeasuredtheRGBLEDsandobtainedtheirx,ycoordinates,andnoticedthatFWHMofthemareabout23nm,40nm,25nmrespectively,whiletheirpeakwavelengthsarearound633nm,525nm,458nm.Inordertotestthemodels,substitutethedataaboveforcorrespondingparametersinequations(6)andthencalculatethecoordinatesandthecolorgamut.Table.1givesthecalculatedresultsbymodelsandthedatameasuredtherealLEDs.Tab.1thecalculatedx,ycoordinatesandcolorgamutcomparingwiththemeasureddataFromtab.1,errorbetweenmeasuredvalueandcalculatedvalueofgreenLEDissolargethatthecalculatedgamutdoesntclosetotherealvalueverywell.Inordertogetamoreaccurateresult,greenLEDmodelusearealRSDcurvedirectly,whosepeakwavelengthandFWHMare525nmand40nm,whichisshowedinfig.2.ThenbyretainingtheshapeoftheRSDcurveandshiftingthepeakwavelength,weusedtheMATLABtocalculatethex,ycoordinatesofgreenLEDs:525nm,(0.2004,0.7138);515nm,(0.1469,0.6800).Sothecalculatedgamutinthetab.1changeto118.6%NTSCand114.0%NTSCrespectively,whichalmostequaltothemeasuredgamut.第5页Fig.2RSDcurveofarealgreenLEDFromtheRGBRSDmodelsabove,colorgamutofathree-basic-colorLEDbacklightcanfollowas:),(0bogrgamuntt（7）Where,arethepeakwavelengthsofRGBLEDsrespectively.0rg0b3.SIMULATIONANDANALYSISWhendesigningaLEDbacklight,itsluminancemustbetakenintoaccountasthesameasthecolorgamut.Recently,theluminousefficacyofLEDisstilllow,anditsluminancevarieswithwavelength.SotheappropriaterangesofpeakwavelengthsofthreebasicLEDsarechosen:620nm-650nmforredLEDs,510nm-530nmforgreenonesand450nm-475nmforblueones.BaseonRSDmodelsofthethreekindsofLEDs,wecalculatedandanalyzedthecombinationsofthreebasiccolors,whosepeakwavelengthsareintherangesabove,tostudytherelationshipofcolorgamutandthepeakwavelengthsof第6页thethreebasiccolors.Whenthepeakwavelengthofgreenlightis521nm(correspondingdominantwavelengthapproximatelyis528nm),thecolorgamutofthree-basic-colorbacklightreachesmaximum.Andthecolorgamutincreasesmonotonouslyasredlightpeakwavelengthincreaseswhenthoseofthegreenandbluelightsstayinvariable,butdecreasesmonotonouslyasbluelightpeakwavelengthincreaseswhenthoseofthegreenandredlightsstayinvariable.Moreover,wefindthatthecombinationofpeakwavelengths(650nm,521nm,450nm)isoptimum,anditscolorgamutcanreachesmorethan120%NTSC.Showinfig.3.Fig.3therelationshipofcolorgamutandR,G,BwavelengthrespectivelyAndfurthermore,thecombinationsofthreecolorsforthegamutof115%NTSCand110%NTSCareplottedinpictures,showinfig.4andfig.5respectively第7页Fig.4combinationsofthreecolorsforthegamutof115%NTSCFig.5combinationsofthreecolorsforthegamutof110%NTSC4.CONCLUSIONInthispaper,therelativespectrumdistributionmodelsofRGBLEDsareestablished.Throughsimulatingthosemodels,therelationshipsthatthecolorgamutofthreebasiccolorsLEDbacklightvarieswitheachcolorareanalyzed,andtheoptimumcombinationofthreecolorsisobtainedwithinthegivenwavelengthsranges.Furthermore,thecombinationsofthreecolorsforthegamutof115%NTSCand110%NTSCareplotted,respectively,andthosepicturesmayofferanintuitionalguidancetochoosetheappropriatethree-colorcombination.第8页中文翻译稿研究配色广色域LED背光的LCD应用程序比较与传统张智胜(冷阴极荧光灯)背光,three-basic-colorLED背光有一些优势,如良好的色彩再现,寿命长、无铅等。从理论上讲,色域是由x,y坐标的三种基本颜色CIE色度图,与x,y坐标的基本颜色可以来源于相对光谱分布(RSD)的领导。摘要红色,绿色和蓝色发光二极管的RSD模型建立计算和分析背光的颜色范围。通过模拟这些模型的关系,LED背光的颜色范围随每种颜色进行了分析,并得到最佳的三种颜色组合在给定的波长范围。此外,三种颜色的组合的115%NTSC和110%NTSC绘制的图片。1.介绍1931年cie色度图,三分对应的RGB颜色构造一个三角形,所有颜色可复制的三种基本颜色。决定了色域的面积,更广泛的色域,颜色越多系统可以复制。NTSC的广播标准定义基于比色阴极射线管显示器的特点。在NTSC标准照明使用C或D65和three-basic-color坐标和色域是显示在图1。NTSC系统将以下的颜色范围比较与其他显示系统的色域第9页图一:NTSC:色域在色度图最近,张智胜背光仍然占据在液晶显示领域的主导地位,然而,张智胜背光是可怜的色彩再现NTSC和色域只达到约76%,很明显这个缺点让张智胜背光液晶背光失去越来越多的市场。另一方面,领导通过几年的迅速发展开辟了LED背光的机会代替张智胜背光液晶显示器行业等优势,良好的色彩再现,寿命长、无铅等。显示的颜色范围可以扩大利用饱和原色,从LED是高度饱和和颜色,因为半最大值(全波在牧场最大)LED的光谱是狭窄的。所以与LED背光显示可以获得广泛的色域,通常超过110%NTSC,能够忠实地再现现实生活的美丽色彩1-2。在本文中,我们建立了红色、绿色和蓝色发光二极管的RSD模型。基于模型、三色RSDs被保留形状和模拟峰值波长转移。那么大量的色域三种基本颜色的组合计算并与NTSC的色域。一些组织的三种基本颜色的组合可以有宽色域超过一定百分比的NTSC颜色范围。2.RSD模型建立显示的色域是由x,y坐标的三种基本颜色。我们可以获得x,y坐标从以下方程:)/(ZYXx（1）)/(y（2）第10页在X,Y,Z是人类眼睛的三色值对应于RGB颜色分别的感觉。和三色值可以通过计算RSD的积分和光谱三色值为:dxkX)(（3）ykY)(（4）dzkZ)(（5）k是规范化的因素,()是相对光谱分布、和x”(),y()、z()光谱三色值的CIE标准观察者。从方程(1)-(5),我们知道RSDs确定颜色的色度坐标,随后确认的色域显示系统。设备的主要参数影响的RSDs材料和结构等约,我们采取0.5,RSDs的半最大值,作为一个常数,而设备的材料和结构都是一样的。当峰值波长o和半最大值0.5众所周知,RSD的领导可以被描述为3:3/)(5exp2/)(exp)(25.05.0I（6）然后我们测量了RGBled和获得他们的x,y坐标,并注意到半最大值约23海里,40nm,分别25纳米,而峰值波长633nm左右,525nm、458nm。为了测试模型,用上面的数据代替相应的参数方程(6),然后计算坐标和色域。怎么让模型的计算结果和数据测量了真正的发光二极管。表1计算x,y坐标和色域与实测数据进行比较从表1看出,测量值和计算值之间的误差很大,领导的绿色计算域不接近实际价值很好。为了得到更准确的结果,绿色领导模型使用一个真正的RSDcurvedirectly,其峰值波第11页长和半最大值是52