chapter 6 output3. crt monitors课件

《chapter 6 output3. crt monitors课件》由会员上传分享，免费在线阅读，更多相关内容在教育资源-天天文库。

1、CHAPTER6outputCRTMonitorsCathode-raytube(CRT)MonitorsPrimaryoutputdevice–VideomonitorsStandarddesignofvideomonitor:Cathode-raytube(CRT)Cathode-raytube(CRT)MonitorsDisplayTechnologiesCathode-raytube(CRT)MonitorsRefreshCRTBeamofelectronshitphosphor-coatedsc

2、reen,lightemittedbyphosphorDirectelectronbeamtothesamescreenrepeatedly,keepingphosphoractivatedThefrequencyatwhichapictureisredrawnonthescreenisreferredtoasthe“refreshrate”ThemaximumnumberofpointsthatcanbedisplayedonaCRTisreferredtoasthe“resolution”http://

3、en.wikipedia.org/wiki/Display_resolutionDisplayprincipleRasterScanDisplayPrincipleRandomScanDisplayPrincipleCRTDisplayPrinciplesRaster-ScanDisplaysBasedonTVtechnologyElectronbeamsweptacrossscreenonerowatatimefromtoptobottomEachrowisreferredtoasascanlineCR

4、TDisplayPrinciplesRaster-ScanDisplaysPictureelements:screenpointreferredas“Pixel”Pictureinformationstoredinrefresh(frame)bufferCRTDisplayPrinciplesRaster-ScanDisplaysPictureinformationstoredinrefresh(frame)bufferThenumberofbitsperpixelintheframebufferiscal

5、leddepthorbitplanesBufferwith1bitperpixel–BitmapBufferwithmultiplebitsperpixel–PixmapInterlacedrefreshprocedureBeamssweepsacrosseveryotherscanlineFrameBufferAframebufferischaracterizedbysize,x,y,andpixeldepth.theresolutionofaframebufferisthenumberofpixelsi

6、nthedisplay.e.g.1024x1024pixels.BitPlanesorBitDepthisthenumberofbitscorrespondingtoeachpixel.Thisdeterminesthecolorresolutionofthebuffer.Bilevelormonochromedisplayshave1bit/pixel8bits/pixel->256simultaneouscolors24bits/pixel->16millionsimultaneouscolorsSpe

7、cifyingColordirectcolor:eachpixeldirectlyspecifiesacolorvaluee.g.,24bit:8bits(R)+8bits(G)+8bits(B)palette-basedcolor:indirectspecificationusepalette(CLUT)e.g.,8bitspixelcanrepresent256colorsGreenRedBlue88824bitsplane,8bitspercolorgun.224=16,777,216RefreshR

8、atesandBandwidthFramespersecond(FPS)InterlacedScanningScanframe30timespersecondToreduceflicker,divideframeintotwofields—oneconsistingoftheevenscanlinesandtheotheroftheoddscanlines.Evenandoddfieldsarescannedou