InCell触摸屏原理课件

In-Cell触摸屏原理2010.3.15Introductionoftouchpanel1.Resistivetouchpanel

1.1traditionalresistivetouchpanel(directlyglueonLCDmodule)

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

1.2integrateresistivetouchpanelintoLCDcell(betweentopandbottomglasses)2.Capacitivetouchpanel

2.1capacitancechangedbydeformationoftopglass

2.2capacitancechangedbyinducedcurrentfromfinger2.2.1surfacecapacitivetouchpanel

2.2.2projectivecapacitivetouchpaneldetectselfcapacitancedetectmutualcapacitance3.Othertouchpanel(Infrared,SAW,Electromagnetic,Optical…)Resistivetouchpanel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。1.14-wireresistivetouchpanelLowlifetime(around1milliontimes)Lowtransmissivity(75%-85%)NotresistscratchLowestcostEasydetectcircuitWorkswithanystylus1.2Incellresistivetouchpanel—samsung(1)Basicprinciple: Whenpressed,thesensorswitchison(conductivecolumnspacercontactsensorelectrode) Fromplanview,attouchpoint,commonelectrodecontacttwosensinglinesperpendicularwitheachotherrespectively2.Capacitivetouchpanel

2.1capacitancechangedbydeformationoftopglass

2.2capacitancechangedbyinducedcurrentfromfinger2.2.1surfacecapacitivetouchpanel

2.2.2projectivecapacitivetouchpaneldetectselfcapacitancedetectmutualcapacitanceCellgapchangetype(1)Samsung’spatent(US20080048994)onlyposedabasicprinciple,itslayerstructureanddetaileddetectmethodisnotshowninthepatent.ThoughAUOhasmadeademo,thereareveryfewopenmaterialsofitsdetectprinciple.Theyusethesameprinciple:detectthecapacitancechangebetweencommonelectrodeandsenseelectrodebycellgapdeformation.Therearemanywaystodetectcapacitancechange,whichwaySamsungandAUOusedisunknown.AUOSamsungCellgapchangetype(2)AUO和LG的压力式内嵌触摸屏样品LCalignmentchangetype—Samsung(1)Samsung’spatent(US20050094038)firstproposedthismethod: BecausedifferentLCalignmenthasdifferentdielectricconstant,andwhenpressed,theLCalignmentischanged,sothattheLCcapacitancechanged.2.2.1SurfacecapacitivetouchpanelHave2conductivecoatings.Upperconductivecoatingistheworkingplane.Lowercoatingisshieldingplane.SurfacecapacitivetouchpanelSurfacecapacitivetouchpanelprinciple:Touchpointistreatedasconnectingtogroundbyacapacitor.Theresistorfromtouchpointto4cornersR1-4isrelatedtothedistancefromtouchpointto4corners.Themorethedistanceis,themoretheresistoris.Whenaddsinesignalon4corners,thecurrentat4cornersI1-4isinverseproportiontorelatedR1-4.BymeasuringI1-4,thetouchpointcanbedetected.SurfacecapacitivetouchpanelLonglifetime(around100milliontimes)Highertransmissivity(Canreach90%)OnlyworkwithfingersHighercostPatentissueComplexdetectcircuitFastresponsespeedSelfcapacitance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。DetectselfcapacitancePanellayout:generallyusing‘diamond’pattern,sothecapacitorfromfingertobothITOlayerswillbebigenough.Thedetectsequenceis,firstdetectselfcapacitanceatonelayer(red),onelinebyoneline,togetXposition,thendetectanotherlayer(blue),togetYposition.Sothisisfakemulti-touch.Projectivecapacitivetouchpanel自电容的多点触摸定位问题：MutualcapacitancePanel图案MutualcapacitanceDrivingmethod:Atdrivelayer(red),addpulsesignalonelinebyoneline,andotherlinesconnecttoground.Atsenselayer(blue),detectchargeonebyone.Whenallintersectionisdetected,themostchargedecreasedintersectionisthetouchpoint.Thismethodistruemulti-touch.Soappleclaimedthatiphoneisthefirst‘imagesensing’touchpanelintheworld.上表面和下表面diamond是错开的模型仿真结果NotouchTouchOthertouchtechnology红外：透光度好，价格低，适应恶劣环境缺点：分辨率较低，易损坏在屏幕四边排布红外发射管和红外接收管，一一对应形成横竖交叉的红外线矩阵。用户在触摸屏幕时，手指就会挡住经过该位置的横竖两条红外线，因而可以判断出触摸点在屏幕的位置。

Othertouchtechnology声表面波：透光好，寿命长缺点：易被油污，灰尘等影响，需经常维护X轴发射器X轴接收器反射阵列可触摸区域吸收残波胶带Y轴接收器Y轴