《InCell触摸屏原理》课件VIP

In-Cell触摸屏原理2010.3.151整理pptIntroductionoftouchpanel1.Resistivetouchpanel

1.1traditionalresistivetouchpanel(directlyglueonLCDmodule)

a.4/5/6/8-wireresistivetouchpanelb.digitalresistivetouchpanel(touchswitches,matrix)

1.2integrateresistivetouchpanelintoLCDcell(betweentopandbottomglasses)2.Capacitivetouchpanel

2.1capacitancechangedbydeformationoftopglass

2.2capacitancechangedbyinducedcurrentfromfinger2.2.1surfacecapacitivetouchpanel

2.2.2projectivecapacitivetouchpanel2.2.2.1detectselfcapacitance2.2.2.2detectmutualcapacitance3.Othertouchpanel(Infrared,SAW,Electromagnetic,Optical…)2整理pptResistivetouchpanel基本原理：触摸时，两层ITO互相接触，从而在两层ITO之间形成电阻通路根据上下基板材料，可分为filmonglass,glassonglass,filmonfilm等结构。3整理ppt1.14-wireresistivetouchpanel在两电极上加5V直流电在ITO均匀电阻平面上形成均匀稳恒电流场在另一面的ITO电极上测量电压根据测得电压值（0-5V）确定触摸点的位置用同样方法测量Y坐标4整理ppt1.14-wireresistivetouchpanelLowlifetime(around1milliontimes)Lowtransmissivity(75%-85%)NotresistscratchLowestcostEasydetectcircuitWorkswithanystylus5整理ppt1.2Incellresistivetouchpanel—samsung(1)Basicprinciple: Whenpressed,thesensorswitchison(conductivecolumnspacercontactsensorelectrode) Fromplanview,attouchpoint,commonelectrodecontacttwosensinglinesperpendicularwitheachotherrespectively6整理ppt2.Capacitivetouchpanel

2.1capacitancechangedbydeformationoftopglass

2.2capacitancechangedbyinducedcurrentfromfinger2.2.1surfacecapacitivetouchpanel

2.2.2projectivecapacitivetouchpanel2.2.2.1detectselfcapacitance2.2.2.2detectmutualcapacitance7整理ppt2.1Capacitivetouchpanel(压力式)Thisintegratetypehassomedifferentstructures,includes:Cellgapchangetype Samsungfiledapatent(US20080048994).AUOhasmadeademo.LCalignmentchangetype Samsungfiledpatent(US20050094038)veryearly,butSamsung’sdemoappliedanotherdetectcircuit(SID0724.3),andEpsonmadeademo(SID0855.2)basedonSamsung’sstructurebyusingLTPS,IPSandactivematrixsensorsothatimprovedtheperformance.8整理pptCellgapchangetype(1)Samsung’spatent(US20080048994)onlyposedabasicprinciple,itslayerstructureanddetaileddetectmethodisnotshowninthepatent.ThoughAUOhasmadeademo,thereareveryfewopenmaterialsofitsdetectprinciple.Theyusethesameprinciple:detectthecapacitancechangebetweencommonelectrodeandsenseelectrodebycellgapdeformation.Therearemanywaystodetectcapacitancechange,whichwaySamsungandAUOusedisunknown.AUOSamsung9整理pptCellgapchangetype(2)AUO和LG的压力式内嵌触摸屏样品10整理pptLCalignmentchangetype—Samsung(1)Samsung’spatent(US20050094038)firstproposedthismethod: BecausedifferentLCalignmenthasdifferentdielectricconstant,andwhenpressed,theLCalignmentischanged,sothattheLCcapacitancechanged.11整理pptLCalignmentchangetype—Samsung(2)Samsung和Epson的in-cellLCalignmentchangetypeTPSamsungEpson12整理ppt2.2.1SurfacecapacitivetouchpanelHave2conductivecoatings.Upperconductivecoatingistheworkingplane.Lowercoatingisshieldingplane.13整理pptSurfacecapacitivetouchpanelSurfacecapacitivetouchpanelprinciple:Touchpointistreatedasconnectingtogroundbyacapacitor.Theresistorfromtouchpointto4cornersR1-4isrelatedtothedistancefromtouchpointto4corners.Themorethedistanceis,themoretheresistoris.Whenaddsinesignalon4corners,thecurrentat4cornersI1-4isinverseproportiontorelatedR1-4.BymeasuringI1-4,thetouchpointcanbedetected.14整理pptSurfacecapacitivetouchpanelLonglifetime(around100milliontimes)Highertransmissivity(Canreach90%)OnlyworkwithfingersHighercostPatentissueComplexdetectcircuitFastresponsespeed15整理ppt2.2.2投射电容触摸屏(PCT)投射电容触摸屏（projectivecapacitivetouchpanel）可分为两种不同的结构：自电容(selfcapacitive)与互电容(mutualcapacitive)自电容为较早的技术，来源于touchkey,touchpad互电容技术由iphone发扬光大，发展迅猛，将逐渐取代自电容类型16整理pptSelfcapacitance自电容原理为当手接触时，等效为parasiticcapacitance增加，而且自电容检测都是在前端（提供电源端）。检测原理有很多，可检测电压、电流、电荷，下图为chargetransfer检测原理。通过开关依次开合不断对parasiticcapacitance进行充电放电，检测放电时通过的电荷，当有手指接触时，流出电荷增加。17整理pptDetectselfcapacitancePanellayout:generallyusing‘diamond’pattern,sothecapacitorfromfingertobothITOlayerswillbebigenough.Thedetectsequenceis,firstdetectselfcapacitanceatonelayer(red),onelinebyoneline,togetXposition,thendetectanotherlayer(blue),togetYposition.Sothisisfakemulti-touch.18整理pptProjectivecapacitivetouchpanel自电容的多点触摸定位问题：19整理pptMutualcapacitance互电容原理为：当手指接触时，等效为互电容改变，互电容检测一般是在后端（sense端）。可以检测电压或者电荷。下图为电荷检测等效电路。手指接触后等效为互电容减小，此时读出电荷减小。模型一20整理pptMutualcapacitancePanel图案21整理pptMutualcapacitanceDrivingmethod:Atdrivelayer(red),addpulsesignalonelinebyoneline,andotherlinesconnecttoground.Atsenselayer(blue),detectchargeonebyone.Whenallintersectionisdetected,themostchargedecreasedintersectionisthetouchpoint.Thismethodistruemulti-touch.Soappleclaimedthatiphoneisthefirst‘imagesensing’touchpanelintheworld.上表面和下表面diamond是错开的22整理ppt模型仿真结果NotouchTouch23整理ppt互电容的优点互电容相对自电容的显著优点：对地寄生电容对触控检测影响很小，更适合在集成触摸屏结构具有更强的抵抗LCD噪声能力可以实现真正的多点触摸（不会有鬼点）但互电容是一个更加新的技术，目前几乎