InCell触摸屏设计及工艺(陈悦)

In-Cell触摸屏设计及工艺IntegratedtouchpanelcategoryIntegratedtouchpanelincludesstructuresbelow:1.resistivetype1.1integratetraditionalresistivetouchpanelon-cell1.2integrateresistivetouchpanelin-cell(Samsung)2.capacitivetype2.1capacitancechangedbydeformationoftopglassin-cell(AUO,Samsung,Epson)2.2capacitancechangedbyinducedcurrentfromfinger2.2.1integratedsurfacecapacitivetouchpanelon-cell2.2.2integratedprojectivecapacitivetouchpanelon-cell(AUO,CMO,Wintek)2.2.3integratedprojectivecapacitivetouchpanelin-cell3.opticaltypein-cell(AUO,LG,Sharp,TMD)Opticaltypein-cellTP光学in-cell触摸屏是在LCDTFTarray基板上集成进一些光敏器件。有两种工作方式，一种如下图：靠激光笔的光被光敏器件感应以确定位置。另一种是用手指遮挡环境光从而使光敏器件感应。但这两种方式都有较大限制。Opticaltypein-cellTPTMD,AUO,LGD,Sharp均有光学内嵌触摸屏样品面世。Integratetraditionalresistivetouchpanelon-cellTouchpanelstructureanddrivingcircuitissametotraditional4-wireorotherresistivetouchpanels.Comparedwithnon-integratedtouchpanel,thisstructureremovedoneglasslayer.Integrateresistivetouchpanelin-cellThisintegratetypehassomedifferentstructures,includes:Samsungstructure Filedpatent(US20070070047) haveSIDpaper(SID0855.1) madeademoin2007Philipsstructure Filedpatent(US20060262099) haveSIDpaper(SID043.5)

In-cellresistivetouchpanel—samsung(1)Basicprinciple: Whenpressed,thesensorswitchison(conductivecolumnspacercontactsensorelectrode) Fromplanview,attouchpoint,commonelectrodecontacttwosensinglinesperpendicularwitheachotherrespectivelyIn-cellresistivetouchpanel—samsung(2)Onepossiblestructureislikebelow.Useonecolumnspacercontact2sensingelectrodessimultaneously.Soatthetouchedpoint,XsensorlineandYsensorlineconnectedtothecommonelectrode.FromPhilips’research,thetopglassneedtobepolishedto0.2mmtogeta0.3umcellgapdisplacementbya0.15Nforce.In-cellresistivetouchpanel—samsung(3)Layerstructurecanbelikebelow,senseline1usegatemetal,senseline2useS/Dmetal,senselinescontactsenseelectrodes(onthepixelITO)throughvia.In-cellresistivetouchpanel—samsung(4)Detectmethod:DetectXandYrespectivelyandgetthetouchposition.Detectmethodistocomparethelinesignaltoareferencevoltagetodetermineifthereisafingertouch.Capacitivetouchpanel(压力式)Thisintegratetypehassomedifferentstructures,includes:Cellgapchangetype Samsungfiledapatent(US20080048994).AUOhasmadeademo.LCalignmentchangetype Samsungfiledpatent(US20050094038)veryearly,butSamsung’sdemoappliedanotherdetectcircuit(SID0724.3),andEpsonmadeademo(SID0855.2)basedonSamsung’sstructurebyusingLTPS,IPSandactivematrixsensorsothatimprovedtheperformance.CellgapchangetypeSamsung’spatent(US20080048994)onlyposedabasicprinciple,itslayerstructureanddetaileddetectmethodisnotshowninthepatent.ThoughAUOhasmadeademo,thereareveryfewopenmaterialsofitsdetectprinciple.Theyusethesameprinciple:detectthecapacitancechangebetweencommonelectrodeandsenseelectrodebycellgapdeformation.Therearemanywaystodetectcapacitancechange,whichwaySamsungandAUOusedisunknown.AUOSamsungCellgapchangetypeAUO和LG的压力式内嵌触摸屏样品LCalignmentchangetype—Samsung(1)Samsung’spatent(US20050094038)firstproposedthismethod: BecausedifferentLCalignmenthasdifferentdielectricconstant,andwhenpressed,theLCalignmentischanged,sothattheLCcapacitancechanged.LCalignmentchangetype—Samsung(2)Samsung’sdemousethisstructure:Eachlinesensorisplacedevery8pixels.EachsensorlineconnectwithmanydummyLCpixelsandmanyreferencecapacitors.Dummypixelsareallcoveredbyblackmatrix.WhenLCcapacitancechanged,thevoltagebetweenClcandCrefalsochanged,sothetouchpositioncanbedetermined.LCalignmentchangetype—Samsung(3)Thesequenceofeachdetectionis: Firstclosesw1,applyVatoLCandinitializethealignmentofLC(thiswilltakeseveralmilliseconds).Then,applyVbtoLCtosetthevoltagebiastoamplifieroperatingcondition(topreventsaturationofchargeamplifier).Finally,readoutthevoltagechangeofnodebetweenClcandCreftodetectafingertouch.LCalignmentchangetype—Samsung(3)Samsung和Epson的in-cellLCalignmentchangetypeTPSamsungEpsonIntegratesurfacecapacitivetouchpanel(1)Surfacecapacitivetouchpanelprinciple:Touchpointistreatedasconnectingtogroundbyacapacitor.Theresistorfromtouchpointto4cornersR1-4isrelatedtothedistancefromtouchpointto4corners.Themorethedistanceis,themoretheresistoris.Whenaddsinesignalon4corners,thecurrentat4cornersI1-4isinverseproportiontorelatedR1-4.BymeasuringI1-4,thetouchpointcanbedetected.Integratesurfacecapacitivetouchpanel(2)Touchpanelstructureanddrivingcircuitissametotraditionalsurfacecapacitivetouchpanel.Comparedwithnon-integratedtouchpanel,thisstructureremovedoneglasslayer.Integratedprojectivecapacitivetouchpanelon-cellSofar,ApplefiledintegratedPCTpatent(US20080062148),buthavenotmadedemoyet.Apple’spatentusedmutualcapacitancetechnology.AUO,CMO,Wintekallexhibiteddemosofon-cellcapacitiveTPOn-cellTPhasatleastoneworkinglayeraboveLCDCFglass.AUOAppleIntegratedprojectivecapacitivetouchpanelon-cellAUO,CMOon-cellcapacitivetouchpanel.IntegratedprojectivecapacitivetouchpaneloncellstructureTheseare3differenton-cellstructureproposedinapple’spatentapplication.ThedetectmethodofApple’sintegratedtypePCTissametomutualcapacitancedetectmethoddescribedbefore.Thelayerstructurecanbeasfollows.Structure1:IntegratedApple’sPCTdirectlyontoLCDtopglass.Integratedprojectivecapacitivetouchpanelon-cellStructure2:Senselayer(ITO1)isabovethetopglass,anddrivelinesandcommonelectrodeshareasameITO(ITO2),VcomandVdriveappliedondifferentdrivelines(commonITO)att