CN103699278B - Self-capacitance change detection method and self-capacitance sensing device for touch screen - Google Patents

Abstract

The invention provides a self-capacitance change detection method and a self-capacitance sensing device for a touch screen; the self-capacitance sensing device comprises a rectangular electrode and a self-capacitance change detection unit which is provided with a variable acquisition module. The variable acquisition module comprises a constant current source, a clamping circuit and a charge transceiving detection circuit which are electrically connected at a first node, and a grounded second node. In a detection process for one electrode, the first node of the variable acquisition module is first electrically connected with a first end of the electrode, and the second node is electrically connected with a second end of the electrode; after a first self-capacitance variable is acquired, the first node of the variable acquisition module is then electrically connected with the second end of the electrode, and the second node is electrically connected with the first end of the electrode, so as to acquire a second self-capacitance variable. The self-capacitance sensing device has the characteristics of simple production process, high production efficiency, good electrode reliability, no easiness in breakage, wide scope of application of electrode materials, and good anti-electro-static discharge (ESD) performance.

Description

Self-capacitance change detecting method and self-capacitance sensing device for touch screen

Technical field

The present invention relates to the detection method of transducing signal and realize the device of the method, particularly relating to for touch screen, touching information is converted to the method for self-capacitance variable and realizes the device of the method.

Background technology

Self-capacitance touch screen is as the one of capacitive touch screen, based on self-capacitance sensing device.This capacitance sensingDevice will be converted to self-capacitance variable signal to the touching information of touch screen, and determines touch position according to self-capacitance variable signalCoordinate.Described self-capacitance sensing device can be not only used for manufacturing independent touch screen, it is also possible to connected applications is at relevant deviceIn, such as self-capacitance sensing device is combined on the display device, make touch display screen.Described self-capacitance sensing device due toIt has only to single-layer layout's wiring, and production technology is simple, and yield is high, and low cost is got on intelligent machine and panel computerMore it is widely applied.The electrode arrangement figure of prior art monolayer self-capacitance sensing device as shown in figure 12, uses triangleThe electrode 91 of shape or class triangle, each electrode 91 be arranged in pairs into complementation electrode to 92, each electrode is to 92 repeatedly stackingsIt is covered with the screen body of whole touch screen or display screen.Just it is apparent that each electrode from electrode arrangement shown in Figure 12There is no the situation of cross wiring between 91, make production process relatively simple.Prior art self-capacitance sensing device also includes being electrically connectedConnect the self-capacitance detector unit of each electrode 91.

Figure 13 and Figure 14 illustrates the ultimate principle that self-capacitance detects.Electrode 91 generally covers one layer be situated between with transparent insulationThe cover plate 93 that material is made.The self-capacitance of self-capacitance sensing device, i.e. electrode 91 arrive the electric capacity on ground, Cp as shown in fig. 13 that.When human body 94 touches on cover plate 93, owing to human body is similar to a earth, be equivalent on electrode 91 is in parallel again oneTo the electric capacity Cf on ground, thus electrode 91 is made to increase, as shown in Figure 13 and Figure 14 to the self-capacitance on ground.Changed by detecting self-capacitanceSituation, it can be determined that go out and whether touch.

As shown in figure 12, long base is positioned at the electrode 91 in left side by 911L, 912L ..., 91(M-1) L, 91ML, 91(M+1) L ... numbering, long base is positioned at the electrode 91 on right side by 911R, 912R ..., 91(M-1) R, 91MR, 91(M+1) R ... volumeNumber, M represents a natural number.Two electrodes 91 of same numbers numbering constitute an electrode pair, and such as, numbering is the electricity of 91ML Yu 91MRPole 91 constitutes electrode pair.When occurring to touch, self-capacitance detector unit is by detecting the self-capacitance variable of each electrode 91.TouchPoint 99 causes six electrodes 91 to occur self-capacitance to change, and their numbering is 91(M-1 respectively) L, 91ML, 91(M+1) L, 91(M-1) R, 91MR and 91(M+1) R.Correspondingly self-capacitance variable is Dp1, Dp2, Dp3, Dp4, Dp5 and Dp6 respectively.FirstFind out the maximum passage of variable quantity on longitudinal direction be touch the passage occurred, i.e. variable quantity be Dp2, numbering be 91ML correspondence electricityThe passage of pole 91, in conjunction with the variable quantity of its lower channel, obtains its position of centre of gravity, is the ordinate of orthogonal axes of touch point；By becomingThe passage of change amount maximum and the ratio of opposite triangular-shaped electrodes variable quantity thereof, draw the coordinate in X direction.

Prior art self-capacitance sensing device there is also following defect and weak point:

1. complex manufacturing；The electrode 91 of prior art self-capacitance sensing device, typically all cannot in actual productionMake real triangle, and with the trapezoidal replacement of class triangle；In order to obtain reasonable precision in the X-axis direction, generallyRequire trapezoidal narrow one side, such as shown in Figure 12, numbering is the right side of the electrode 91 of 911L, and width is the smaller the better, usually requires that0.3mm is the least, and technological ability be there are certain requirements by this, becomes and affects one of the factor that production cost reduces；

2. production process is many；The minimum detection unit of traditional structure is a diabolo, and linear in order to improve setting-outDegree, also can split into two or more little trianglees each triangle in parallel, and such electrode structure comes for laser technologySaying, need cutting many times, becoming another affects the factor that production cost reduces；

3. for using the touch screen module of flexible substrate, such as, make base material with thin-film material, if at this base materialThe electrode 91 of upper employing prior art self-capacitance sensing device, owing to the tip of triangular-shaped electrodes 91 is very thin, producing, transport,If base material bends in test process, may result in electrode district for manufacturing the transparent conductive material of electrode, such as oxygenChange indium stannum Indium Tin Oxide to rupture, and make self-capacitance sensing device, so touch screen from being damaged；Described triangleThe easy damage structure of electrode 91 is also to affect the factor that production cost reduces；

4. electrode material requires height；For the material of some novel manufacture electrodes 91, such as wire netting metal mesh materialMaterial, good in order to ensure to constitute overlap joint between the tinsel of wire netting, the minimum widith of electrode 91 can be than existing tin indium oxideITO material is big, it should at more than 1mm, and this minimum widith is for being used for prior art triangular-shaped electrodes 91 manufacturing self-capacitance biographyInduction device is beyond affordability；

5. anti-static electrictity release Electro-Static Discharge poor performance；Electrically conducting transparent material for existing main flowMaterial tin indium oxide ITO, its impedance is relatively big, if it occur that Electro-static Driven Comb esd event, in the region that tin indium oxide ITO width is less,Such as width is at below 0.1mm, is easier Electro-static Driven Comb ESD, causes short circuit between tin indium oxide ITO electrode.

Summary of the invention

Propose a kind of for touch screen in place of the technical problem to be solved in the present invention is to avoid the deficiencies in the prior artSelf-capacitance change detecting method, and application the method self-capacitance sensing device, by modified electrode structure, use newSelf-capacitance detection method, makes the production cost of self-capacitance sensing device reduce, promotes its overall performance.

The present invention solves described technical problem can be by realizing by the following technical solutions:

Proposing a kind of self-capacitance change detecting method for touch screen, based on self-capacitance sensing device, this self-capacitance passesInduction device includes at least one electrode.Described electrode is included in the first end in the first direction and the second end.Described method is for oftenIndividual electrode performs following steps,

A. at the first end electrical connection constant-current source, clamp circuit and the electric charge transmitting-receiving testing circuit of electrode, by the of this electrodeTwo end ground connection；Described constant-current source is to the electric current of electrode output constant current value；Described clamp circuit makes the one of institute's electrode electrically connectedThe current potential of end is defined in constant potential；Described electric charge transmitting-receiving testing circuit can output charge or receive electric charge, and detect electricityLotus output or reception amount, quantifying electric charge output is self-capacitance variable；

B. electric charge transmitting-receiving testing circuit has detected whether that electric charge exports；

If there being electric charge to export, then quantifying electric charge output is the first self-capacitance variable, performs step C subsequently；

Export without electric charge, directly perform step E；

C. at the second end electrical connection constant-current source, clamp circuit and the electric charge transmitting-receiving testing circuit of electrode, by the of this electrodeOne end ground connection；

D. electric charge transmitting-receiving testing circuit quantifies electric charge output is the second self-capacitance variable；

E. the self-capacitance change-detection for described electrode terminates.

Specifically, constant-current source described in step A is I to the constant current value that electrode exports, described clamp circuit order institute electricityThe constant potential that the current potential of the one end connecting electrode limits is V1, then it suffices that V1/I=R, R are clamp circuit and constant currentThe resistance of source institute electrode electrically connected.

The present invention solves described technical problem can also be by realizing by the following technical solutions:

Design, manufacture a kind of self-capacitance sensing device for touch screen, including at least one electrode, and electrically connect each electricityThe self-capacitance change detection unit of pole.Described electrode is rectangular, including for electrically connect self-capacitance change detection unit, along shouldFirst end of electrode bearing of trend and the second end.Described self-capacitance change detection unit includes at least one variable acquisition module.ShouldVariable acquisition module includes being electrically connected to the constant-current source of primary nodal point, clamp circuit and electric charge transmitting-receiving testing circuit, and ground connectionSecondary nodal point.During the detection for an electrode, the primary nodal point elder generation electrode electrically connected of described variable acquisition moduleThe first end, and the second end of secondary nodal point electrode electrically connected, after collecting the first self-capacitance variable, variable acquisition modulePrimary nodal point electrically connect the second end of this electrode, and the first end of secondary nodal point electrode electrically connected again, to gather second from electricityHold variable quantity.The current potential of institute's electrode electrically connected one end is limited to constant potential by described clamp circuit, and described constant-current source is to institute's electricityConnect electrode and constant current is provided；Described electric charge transmitting-receiving testing circuit changes to this electrode because of the self-capacitance of its electrode electrically connectedOutput charge, and detect electric charge output, quantifying electric charge output is self-capacitance variable.

The constant potential that the current potential of institute's electrode electrically connected one end is limited by described clamp circuit is V1, and described constant-current source is to instituteThe constant current that electrode electrically connected provides is I, then it suffices that V1/I=R, R are clamp circuit and the electrically connected electricity of constant-current sourceThe resistance of pole.

Specifically, described clamp circuit includes an operational amplifier, and the constant potential that this clamp circuit is limited is by thisThe input voltage of operational amplifier positive input controls.Described electric charge transmitting-receiving testing circuit is used as clamp circuit described in includingOperational amplifier, the electric charge being connected electrically between this operational amplifier inverting input and outfan transmitting-receiving electric capacity, and be electrically connectedConnect the AC-DC conversion submodule of the outfan of described operational amplifier.The current output terminal of described constant-current source and operational amplifierInverting input be both electrically connected with in primary nodal point.

For reset circuit state after detection every time, also it is electrically connected with multiple between the two ends of described electric charge transmitting-receiving electric capacityBit switch.

The concrete structure of a kind of electrode is, at least one drift angle cut formation straightway hypotenuse of described electrode, thusElectrode is processed to the rectangular electrode with hypotenuse.

The concrete structure of another kind of electrode is, at least one drift angle cut formation arc-shaped edges of described electrode, thus electricPole is processed to the rectangular electrode with arc-shaped edges.

The concrete structure also having a kind of electrode is that at least one limit of described electrode is machined with at least two groove, twoForm double wedge between adjacent two grooves, thus electrode is processed to the rectangular electrode with toothed edge.

In concrete application, described electrode tin indium oxide, wire netting or carbon nanomaterial are made.

About the setting of electrode, described self-capacitance sensing device also includes by resins synthesis thin-film material or the glass system of usingThe substrate become, described electrode adheres on the substrate.

When self-capacitance sensing device is combined with display device, described self-capacitance sensing device is arranged on LCDsIn.This LCDs includes the first crystal liquid substrate and the second crystal liquid substrate, and is clipped in the first crystal liquid substrate and the second liquid crystalLiquid crystal material, pixel electrode, chromatic filter layer and black matrix between substrate.Described electrode is attached to described first crystal liquid substrateUpper strata or lower floor, or the upper strata of the second crystal liquid substrate or lower floor.

A kind of electrode Scanning Detction mode, described self-capacitance change detection unit includes a set of variable acquisition module；This setVariable acquisition module is controllably sequentially connected electrically described each electrode, i.e. timesharing ground according to the sequential set and electrically connects each electrode with completeThe self-capacitance change-detection of paired each electrode.

Another kind of electrode Scanning Detction mode, the quantity of described variable acquisition module is less than the quantity of electrode；Each variable is adoptedCollection module controllably electrically connects the partial electrode in all electrodes, i.e. timesharing subregion the most one to one according to the sequential setGround electrically connects each electrode to complete the self-capacitance change-detection to each electrode.

Can also be by man-to-man electrode Scanning Detction mode, described variable acquisition module electrically connects described electricity one to onePole.

When self-capacitance sensing device is combined with display device, described self-capacitance sensing device is arranged on LCDsIn.This LCDs is by display driver circuit chip controls.Described self-capacitance change detection unit is integrated in described display and drivesIn dynamic circuit chip.

When self-capacitance sensing device is combined with display device, detect to coordinate liquid crystal drive and self-capacitance, described fromCapacitive sensing apparatus also includes coordinating detection module.Described self-capacitance sensing device is arranged in LCDs.This liquid crystalDisplay screen is by display driver circuit control.Described coordination detection module electrically connects described self-capacitance change detection unit and display drivesCircuit, to make self-capacitance change detection unit and display driver circuit the most at times and/or subregion completes eachFunction.

The present invention solves described technical problem again can be by realizing by the following technical solutions:

As the extension in terms of data process of the described self-capacitance change detecting method for touch screen, propose one and touchTouch point coordinate data processing method, based on the self-capacitance change detecting method for touch screen described in claim 16, describedEach electrode is sequentially arranged along the second direction being perpendicular to first direction, it is characterised in that described method includes:

F., when a touch points makes the self-capacitance of K electrode change, the K relating to this touch points is got to certainlyCapacitance change, i.e. 2K self-capacitance variable；

G. maximum in 2K self-capacitance variable one is selected；

This maximum self-capacitance variable said electrode is the T electrode in a second direction, this maximum self-capacitance variableBeing the first self-capacitance variable of described T electrode, i.e. DTU, another self-capacitance variable of T electrode is this electrodeThe second self-capacitance variable, i.e. DTV,

Thus the T electrode respective first self-capacitance variable of two lateral electrodes in a second direction is D(T+1 respectively) U, D(T+2) U ..., D(T+W1) U, and D(T-1) U, D(T-2) U ..., D(T-W2) U；Second self-capacitance variable is D(T+ respectively1) V, D(T+2) V ..., D(T+W1) V, and D(T-1) V, D(T-2) V ..., D(T-W2) V, W1+W2+1=K；

If the length that the most each electrode is in the first direction is X0, length in a second direction is Y0, then touch described in step ATouch a little in a second direction coordinate Y be,

,

Lateral coordinates X in the first direction of touch points described in step A is,

。

The most relatively, the present invention " self-capacitance change detecting method and the self-capacitance sensing dress for touch screenPut " have the technical effect that

1. production technology is simple；Electrode shape of the present invention is rectangle, and electrode is longitudinally wide relatively wide, reduces techniqueThe requirement of precision, it is possible to reduce production cost；

2. production efficiency is high；Electrode shape of the present invention uses rectangular configuration, if minimum detection unit cutting one cutterCompleting, production efficiency is high；

3. good reliability, not easy fracture；Electrode of the present invention uses rectangular configuration, and width value is bigger, even if appended by electrodeBase material flexible material to make, during base material bending, electrode is not easy to fracture；

4. pair material requirements is low；Electrode of the present invention uses rectangular configuration, and its minimum width value is relatively big, makes electrode to adoptMake with wire netting metal mesh new material；

5. anti-static electrictity release ESD performance is good；The electrode manufacturing material tin indium oxide ITO of existing main flow, anti-static electrictity releaseESD ability reduces along with width and reduces, and in the present invention, the width value of electrode is bigger, and anti-static electrictity release ESD ability is stronger.

Accompanying drawing explanation

Fig. 1 is the electrode arrangement schematic diagram of self-capacitance sensing device of the present invention；

Fig. 2 is the electric principle schematic of self-capacitance sensing device of the present invention；

Fig. 3 is self-capacitance sensing device of the present invention electric principle signal of the first self-capacitance variable detection when there is touchingFigure；

Fig. 4 is self-capacitance sensing device of the present invention electric principle signal of the second self-capacitance variable detection when there is touchingFigure；

Fig. 5 is the electric principle schematic of the embodiment of self-capacitance sensing device of the present invention；

Fig. 6 is the present invention structural representation with the rectangular electrode 101 of hypotenuse；

Fig. 7 is the present invention structural representation with the rectangular electrode 102 of arc-shaped edges；

Fig. 8 is the present invention structural representation with the rectangular electrode 103 of toothed edge；

The structural representation of the electrode 10 that Fig. 9 wire netting metal mesh makes；

Figure 10 is the example electricity principle schematic detecting each electrode 10 with a set of variable acquisition module timesharing；

Figure 11 is the cross-sectional structure schematic diagram of LCDs；

Figure 12 is the electrode arrangement schematic diagram of prior art monolayer self-capacitance sensing device；

Figure 13 is the prior art self-capacitance sensing device self-capacitance schematic diagram when there is touching；

Figure 14 is the prior art self-capacitance sensing device equivalent electric principle schematic when there is touching.

Detailed description of the invention

It is described in further detail below in conjunction with accompanying drawing illustrated embodiment.

Complex manufacturing that the present invention brings for prior art triangular-shaped electrodes of forgoing, production process is many, easily lose,Electrode material requires the high and defect of anti-static electrictity release ESD poor performance, uses rectangular electrode.Rectangular electrode compares triangular-shaped electrodesObviously production technology simplifies, decreases production process.Rectangular electrode is bigger longitudinally wide owing to having, and electrode is attached to softOn base material, even if base material bending is not easy to lose；And bigger longitudinally wide of rectangular electrode meets wire netting metal meshThe material requirement to minimum widith, is suitable to make electrode with mesh materials；Also due to rectangular electrode has bigger longitudinal directionWidth, also improves the anti-static electrictity release ESD performance of electrode.As it is shown in figure 1, the self-capacitance sensing device that the present invention proposes includesRectangular electrode 10, electrode 10 is extended by the abscissa direction of rectangular coordinate system, and each electrode 10 is along the vertical coordinate side of rectangular coordinate systemIt is covered with in whole touch area to parallel to each other.Certainly, electrode 10 is extended by the vertical coordinate direction of rectangular coordinate system, each electrode10 parallel to each other along the abscissa direction of rectangular coordinate system are covered with whole touch area, are also the feasible programs of a kind of equivalent.As it is shown in figure 1, for the ease of being explained later, each electrode 10 S1 ..., Sn designate respective numbering, wherein n be value be fromSo variable of number, thus the electrode 10 that numbering is Sn can represent the arbitrary electrode 10 being suitable to all electrodes 10.Each electrode 10 edgeThe X-direction of bearing of trend, i.e. rectangular coordinate system has two ends, and electrode 10 each includes the first end L and the second end R, then compileThe electrode 10 of number S1 just has the first end S1L and the second end S2R, and by that analogy, numbering is that the electrode 10 of Sn includes the first end SnLWith the second end SnR.

As in figure 2 it is shown, self-capacitance sensing device of the present invention also includes the self-capacitance change-detection list electrically connecting each electrode 10Unit 2, realizes the detection to the change of each electrode self-capacitance by this self-capacitance change detection unit 2.This self-capacitance change detection listUnit 2 completes to change for the self-capacitance of the electrode 10 electrically connected with this variable acquisition module 21 especially by variable acquisition module 21The detecting of amount and collection.Being arbitrary electrode 10 of Sn for numbering, the first end SnL of electrode 10 is connected respectively to electric charge transmitting-receiving inspectionSlowdown monitoring circuit 211, constant-current source 212 and clamp circuit 213.Second end SnR of electrode 10 connects ground.Thus electric charge transmitting-receiving testing circuit211, constant-current source 212 and clamp circuit 213 are both electrically connected with the primary nodal point a in variable acquisition module 21, this variable acquisition moduleThe secondary nodal point b ground connection of 21.Constant-current source 212 flows in or out the electric current of a fixed size.Clamp circuit 213 by primary nodal point a,I.e. the first end SnL end of electrode 10 is clamped to a fixed voltage, and electric charge transmitting-receiving testing circuit 211 can flow in or out electric charge,And the size of the flowed in or out quantity of electric charge can be detected.

The voltage of 213 clampers of clamp circuit is V1, and the resistance of electrode 10 go-and-retum is R, and the electric current of constant-current source 212 is I,Relation between them is: V1/R=I.So, in the case of touching, the electric current I that constant-current source 212 provides just makesThe voltage of the first end SnL that the resistance of electrode 10 connects current source and clamp circuit maintains V1, without electric charge transmitting-receiving inspectionSlowdown monitoring circuit 211 flows in or out electric charge, and the electric charge that when i.e. not occurring to touch, electric charge transmitting-receiving testing circuit 211 detects is 0.

Electrode 10 can be equivalent to k resistance R1, R2, R3 ..., Rj ..., the series connection of Rk, and its resistance is equal, each resistanceUpper end node is respectively 0,1,2 ... k-1, and the bottom crown node of last resistance is k, and node 0 and k is i.e. respectively electrode 10The first end SnL and the second end SnR.

When node 0 receives clamp circuit 213 one end, i.e. the first end SnL of primary nodal point a electrode electrically connected 10, and theDuring the second end SnR of two node b electrode electrically connecteds 10, the voltage of node 0 is V1, node k ground connection, then the voltage on node j is:

, (1).

When node k connects clamp circuit 213 one end, i.e. the second end SnR of primary nodal point a electrode electrically connected 10, and secondDuring the first end SnL of node b electrode electrically connected 10, the voltage of node k is V1, node 0 ground connection, and the voltage on node j is:

(2).

When node j occurs to touch, as it is shown on figure 3, this event can be equivalent between touch point j and ground be connected to oneIndividual electric capacity Ct.

Such as Fig. 3, when the first end SnL of electrode 10 terminates clamp circuit 213, i.e. primary nodal point a electrode electrically connected 10First end SnL, and during the second end SnR of secondary nodal point b electrode electrically connected 10, by formula (1), the voltage on Ct is

,

On Ct by the charge Q 1 of storage it is then

, (3).

Owing to constant-current source 212 can only provide the electric current flow through on resistance string, this charge Q 1 is just by electric charge transmitting-receiving detection electricityRoad 211 provides, and can be become the first self-capacitance variable by its quantization.

After above-mentioned detection completes, then changing the first end SnL of electrode 10 into ground connection, the second end SnR of this electrode 10 connects pincersSecond end SnR of position circuit 212, i.e. primary nodal point a electrode electrically connected 10, and the first end of secondary nodal point b electrode electrically connected 10SnL, as shown in Figure 4.By formula (2), now the voltage on Ct is:

,

On Ct by the charge Q 2 of storage it is then

(4).

Owing to constant-current source 212 can only provide the electric current flow through on resistance string, this electric charge is received and dispatched testing circuit 211 by electric chargeThere is provided, and the second self-capacitance variable can be become by its quantization.

Thus variable acquisition module 21 is for occurring touch electrode 10 that collection is obtained the first self-capacitance variable and secondSelf-capacitance variable totally two self-capacitance variable data.

With regard to this, the present invention proposes a kind of self-capacitance change detecting method for touch screen, based on self-capacitance sensing device,This self-capacitance sensing device includes at least one electrode.Described electrode is included in the first end in the first direction and the second end.SpecificallyIn present invention embodiment as shown in Figure 1, described first direction is exactly the abscissa X-axis side of rectangular coordinate system in embodimentTo.Described method performs following steps for each electrode,

A. at the first end electrical connection constant-current source, clamp circuit and the electric charge transmitting-receiving testing circuit of electrode, by the of this electrodeTwo end ground connection；Described constant-current source is to the electric current of electrode output constant current value；Described clamp circuit makes the one of institute's electrode electrically connectedThe current potential of end is defined in constant potential；Described electric charge transmitting-receiving testing circuit can output charge or receive electric charge, and detect electricityLotus output or reception amount, quantifying electric charge output is self-capacitance variable；

B. electric charge transmitting-receiving testing circuit has detected whether that electric charge exports；

If there being electric charge to export, then quantify electric charge output or electric charge reception amount is the first self-capacitance variable, subsequentlyPerform step C；Obviously the situation this step occur is exactly the touched situation of described electrode；

Export without electric charge, directly perform step E；

C. at the second end electrical connection constant-current source, clamp circuit and the electric charge transmitting-receiving testing circuit of electrode, by the of this electrodeOne end ground connection；

D. electric charge transmitting-receiving testing circuit quantifies electric charge output is the second self-capacitance variable；

E. the self-capacitance change-detection for described electrode terminates.

Described method is to perform an above-mentioned steps for each electrode, completes the self-capacitance change once for this electrodeDetection.Visible described method without electric charge output being detected or receiving electric charge, is just done directly this electricity in stepbThe detection of the self-capacitance change of pole.Electric charge output only detected or receive in the case of electric charge, just carry out primary nodal point withSecondary nodal point exchanges, with electrode the first end and the second end, the operation electrically connected, and continues detection.Certainly, no matter electric charge transmitting-receiving detectsWhether circuit has detected electric charge output or has received electric charge, within a relatively-stationary time period, all carries out primary nodal pointExchange, with secondary nodal point and electrode the first end and the second end, operation electrically connect, and the operating process continuing detection should also be as beThe optional replacement scheme of one of invention such scheme, it should also within protection scope of the present invention.

Constant-current source described in procedure described above A is I to the constant current value that electrode exports, and the order of described clamp circuit is electrically connectedThe constant potential that the current potential of one end of receiving electrode limits is V1, then it suffices that V1/I=R, R are clamp circuit and constant-current sourceThe resistance of institute's electrode electrically connected.

On the basis of said method, the present invention also proposes a kind of self-capacitance sensing device for touch screen, including at least oneElectrode 10, and electrically connect the self-capacitance change detection unit 2 of each electrode 10.Described electrode 10 is rectangular, including for being electrically connectedConnect self-capacitance change detection unit, along the first end of this electrode bearing of trend and the second end.In embodiments of the present invention, electrodeBearing of trend is exactly the direction, place, long limit of rectangular electrode, namely the abscissa X-direction in rectangular coordinate system shown in Fig. 1.Thus described electrode 10 includes the first end SnL and the second end SnR.Described self-capacitance change detection unit 2 includes at least one variableAcquisition module 21.This variable acquisition module 21 includes being electrically connected to the constant-current source 212 of primary nodal point a, clamp circuit 213 and electric chargeTransmitting-receiving testing circuit 211, and the secondary nodal point b of ground connection.During the detection for an electrode 10, described variable collectionFirst end SnL of the primary nodal point a elder generation electrode electrically connected 10 of module 21, and the second end SnR of secondary nodal point b electrode electrically connected,After collecting the first self-capacitance variable, the primary nodal point a of variable acquisition module 21 electrically connects the second end of this electrode 10 againSnR, and the first end SnL of secondary nodal point b electrode electrically connected 10, to gather the second self-capacitance variable.Described clamp circuit 213The current potential of institute's electrode electrically connected 10 one end is limited to constant potential, and described constant-current source 212 provides permanent to institute's electrode electrically connected 10Determine electric current；Described electric charge transmitting-receiving testing circuit 211 changes because of the self-capacitance of its electrode electrically connected 10, exports electricity to this electrode 10Lotus, and detect electric charge output or electric charge reception amount, quantifying electric charge output is self-capacitance variable.

The constant potential that the current potential of institute's electrode electrically connected one end is limited by described clamp circuit is V1, and described constant-current source is to instituteThe constant current that electrode electrically connected provides is I, then it suffices that V1/I=R, R are clamp circuit and the electrically connected electricity of constant-current sourceThe resistance of pole.

As self-capacitance variable data being converted into number of coordinates for the self-capacitance change detecting method of touch screen is follow-upAccording to method, the present invention proposes a kind of touch points coordinate data processing method, and based on described step A to step E being used for touchesThe self-capacitance change detecting method of screen, described each electrode is sequentially arranged along the second direction being perpendicular to first direction.In the present inventionIn embodiment, described first direction is the abscissa X-direction of rectangular coordinate system shown in Fig. 1, thus second direction is exactly Fig. 1 instituteShow the vertical coordinate Y direction of rectangular coordinate system.Described method includes:

F., when a touch points makes the self-capacitance of K electrode change, the K relating to this touch points is got to certainlyCapacitance change, i.e. 2K self-capacitance variable；

G. maximum in 2K self-capacitance variable one is selected；

This maximum self-capacitance variable said electrode is the T electrode in a second direction, this maximum self-capacitance variableBeing the first self-capacitance variable of described T electrode, i.e. DTU, another self-capacitance variable of T electrode is this electrodeThe second self-capacitance variable, i.e. DTV,

Thus the T electrode respective first self-capacitance variable of two lateral electrodes in a second direction is D(T+1 respectively) U, D(T+2) U ..., D(T+W1) U, and D(T-1) U, D(T-2) U ..., D(T-W2) U；Second self-capacitance variable is D(T+ respectively1) V, D(T+2) V ..., D(T+W1) V, and D(T-1) V, D(T-2) V ..., D(T-W2) V, W1+W2+1=K；

If the length that the most each electrode is in the first direction is X0, length in a second direction is Y0, then touch described in step ATouch a little in a second direction coordinate Y be,

,

Lateral coordinates X in the first direction of touch points described in step A is,

。

Said method specific in the embodiment of the present invention, described variable acquisition module 21 collect first, second from electricityHold variable quantity data and be transferred to special coordinate data processor unit, or process the data process of function with coordinate dataDevice.The first, second self-capacitance variable data gathered based on the present invention, touch coordinate data can be according to said method by such asLower concrete scheme obtains, and as shown in Figure 1, it is assumed that touch points affects three adjacent electrodes 10, numbering in an intermediate position is SnElectrode 10 in above-mentioned twice detection, obtain the first self-capacitance variable D3, the second self-capacitance variable D4, wherein firstSelf-capacitance variable D3 is the maximum of all changes amount.So numbering be S(n-1) electrode in twice detection, obtain firstSelf-capacitance variable D1 and the second self-capacitance variable D2.Numbering is S(n+1) electrode 10 twice detection obtain first from electricityHold variable quantity D5 and the second self-capacitance variable D6.If each electrode 10 is along a length of Y0 of the Y direction of rectangular coordinate system, thatThe Y-axis coordinate of touch point is,

(5),

If electrode 10 is X0 at X-axis total length, then the X-axis coordinate adoption rate algorithm of touch point obtains, particularly as follows:

(6).

The present invention proposes an embodiment realizing variable acquisition module 21, as it is shown in figure 5, described clamp circuit 213 includesOne operational amplifier OP, the constant potential that clamp circuit 213 is limited is by the input electricity of this operational amplifier OP positive inputPressure Vf controls.Operational amplifier OP, by the feedback circuit constituted with electric charge transmitting-receiving electric capacity Cc, makes current potential Vf at operational amplifierThe reverse input end of OP forms clamp voltage.Described electric charge transmitting-receiving testing circuit 211 includes the described fortune being used as clamp circuit 213Calculate amplifier OP, the electric charge being connected electrically between this operational amplifier OP inverting input and outfan transmitting-receiving electric capacity Cc, andElectrically connect the AC-DC conversion submodule 2111 of the outfan of described operational amplifier OP.The electric current output of described constant-current source 212The inverting input of end and operational amplifier OP is both electrically connected with in primary nodal point a.Described constant-current source 212 can use existing electricityStream product-derived, or realize the circuit of current source function.When the inverting input having electric charge to flow in or out operational amplifier OPTime, this operational amplifier OP can provide electric charge by electric charge transmitting-receiving electric capacity Cc, and with the output voltage shape of operational amplifier OPFormula weight dissolves, and the variable quantity of this output voltage voltage is inversely proportional to electric charge transmitting-receiving electric capacity Cc.The output electricity of operational amplifier OPBucklingization is converted to digital quantity by AC-DC conversion submodule 2111, thus output to data processor is located furtherReason.

The effect of SW circuit is to reset, and after detection, it just closes once every time, is reverted to by the output end voltage of OPInitial value, then detect next time.

For reset circuit state after detection every time in the above embodiment of the present invention, as it is shown in figure 5, receive at described electric chargeReset switch SW also it is electrically connected with between the two ends of generating appearance Cc.After detection, reset switch SW just Guan Bi once, will every timeThe output end voltage of operational amplifier OP reverts to initial value, then detects next time.

The rectangular electrode of the present invention can also have multiple equivalent structure.As shown in Figure 6, the concrete structure of a kind of electrode is,At least one drift angle cut formation straightway hypotenuse 111 of described electrode 10, thus electrode 10 is processed to hypotenuse 111Rectangular electrode 101.As it is shown in fig. 7, the concrete structure of another kind of electrode 10 is that at least one drift angle of described electrode 10 is cutExcept forming arc-shaped edges 112, thus electrode 10 is processed to the rectangular electrode 102 with arc-shaped edges 112.As shown in Figure 8, also oneThe concrete structure of kind of electrode 10 is that at least one limit of described electrode 10 is machined with at least two groove 113, adjacent two recessed twoForm double wedge 114 between groove 113, thus electrode 10 is processed to the rectangular electrode 103 with toothed edge.

Electrode 10 tin indium oxide ITO of the present invention, wire netting metal mesh or carbon nanomaterial are made.Such as figureShown in 9, electrode 10 wire netting metal mesh makes, and described wire netting is to be overlapped to form netted forming, Fig. 9 by tinsel 115In dotted portion be exactly wire netting equivalence become rectangular electrode shape.

About the laying structure of electrode, described self-capacitance sensing device also includes with resins synthesis thin-film material or uses glassThe substrate that glass is made, described electrode adheres on the substrate.Described electrode can be by pasting, etch, cut or WelderSkill is attached on substrate.

The present invention can be that described self-capacitance change detection unit includes a set of in a kind of electrode Scanning Detction mode usedVariable acquisition module.This set variable acquisition module is controllably sequentially connected electrically described each electrode, i.e. timesharing according to the sequential setGround electrically connects each electrode to complete the self-capacitance change-detection to each electrode.For example, as shown in Figure 10, each electricity shown in Fig. 1Two ends, pole 10 are both electrically connected with the n in self-capacitance change detection unit 2 on port.Described self-capacitance change detection unit 2 is arrangedA pair controlled timesharing electrically connects controlled ports c, d of each pair of port.In described self-capacitance change detection unit 2, a set of change is only setAmount acquisition module 21.When starting to detect, it is a pair port of 1 that controlled ports c, d first electrically connect sequence number, and port is electrically connected by respectivelyMeet the first end S1L and the second end S2R that numbering is the electrode 10 of S1.Described variable acquisition module 21 is according to side of the present inventionMethod, electrically connects controlled ports c, d by primary nodal point a and secondary nodal point b with switching, thus completing is the electrode 10 of S1 to numberingDetection, detection structure is exported to corresponding data processor by variable acquisition module 21.Hereafter controlled ports c, d is by settingSequential electrical connection sequence number be 2 a pair port, be that the electrode 10 of S2 detects to numbering.The rest may be inferred, and controlled ports electrically connectsSequence number is a pair port of n, detects the electrode 10 that numbering is Sn, until after all electrodes 10 are all detected, completing once electricityThe process of pole scanning.This kind of scan mode is exactly to detect all electrodes with a set of variable acquisition module timesharing ground.

Another kind of electrode Scanning Detction mode, the quantity of described variable acquisition module is less than the quantity of electrode；Each variable is adoptedCollection module controllably electrically connects the partial electrode in all electrodes, i.e. timesharing subregion the most one to one according to the sequential setGround electrically connects each electrode to complete the self-capacitance change-detection to each electrode.This programme is similar with examples detailed above situation, simplyBy many set variable acquisition module, the region timesharing being made up of multiple electrodes is completed detection, be that a kind of subregional electrode of timesharing is sweptRetouch mode.

Can also be by man-to-man electrode Scanning Detction mode, described variable acquisition module electrically connects described electricity one to onePole.This kind of scan mode both can realize Time share scanning, it is also possible to realizes the scanning of timesharing subregion.

Described self-capacitance sensing device both may be used for constituting touch screen independent, as input equipment, it is also possible toDisplay device combines and constitutes touch display screen.

When self-capacitance sensing device is combined with display device, described self-capacitance sensing device is arranged on LCDsIn.As shown in figure 11, this LCDs 3 includes the first crystal liquid substrate 31 and the second crystal liquid substrate 32, and is clipped in the first liquidLiquid crystal material 33, pixel electrode 34, chromatic filter layer 35 and black matrix 36 between brilliant substrate 31 and the second crystal liquid substrate 32.InstituteState electrode and be attached to upper strata or the lower floor of described first crystal liquid substrate 31, or the upper strata of the second crystal liquid substrate 32 or underLayer.Described electrode can be by pasting, etch, cut or welding procedure being attached to the first crystal liquid substrate 31 or the second liquid crystalOn substrate 32.

When self-capacitance sensing device is combined with display device, can use with LCDs in terms of circuit is intrinsicCircuit is integrated in the structure in same chip, and described self-capacitance sensing device is arranged in LCDs.This LCDsBy display driver circuit chip controls.Described self-capacitance change detection unit is integrated in described display driver circuit chip.

When self-capacitance sensing device is combined with display device, in order to avoid electrode Scanning Detction and liquid crystal in terms of controlScanning interferes with each other, and described self-capacitance sensing device also includes coordinating detection module.Described self-capacitance sensing device is arranged on liquidIn crystal display screen.This LCDs is by display driver circuit control.Now display driver circuit both can change with self-capacitanceDetector unit is in same chip, it is also possible in chip belonging to being present in independently of each other each.Described coordination detection module electricityConnect described self-capacitance change detection unit and display driver circuit, to make self-capacitance change detection unit and display driver circuitThe most at times and/or subregion completes respective function.Described complete respective function at times and refer to, a settingTime period in, distributing to the self-capacitance change detection unit more than one period completes Scanning Detction, and in this period, display is drivenGalvanic electricity road does not works, and the remaining period is distributed to display driver circuit and completes scanning, self-capacitance change-detection list in this periodUnit does not works.Described subregion completes respective function and refers to, screen body is divided into the most misaligned multiple region, and coordinated allocation is from electricityHold change-detection unit and display driver circuit implements scanning in different regions, namely for the same area, carry out certainlyThe when that capacitance detecting scanning, do not carry out display and drive scanning, and the when of carrying out display driving scanning, do not carry out self-capacitance inspectionSurvey scanning.

Claims (16)

1., for a self-capacitance sensing device for touch screen, including at least one electrode, and electrically connect the self-capacitance of each electrodeChange-detection unit；It is characterized in that:

Described electrode is rectangular, including for electrically connect self-capacitance change detection unit, along the first of this electrode bearing of trendEnd and the second end；

Described self-capacitance change detection unit includes at least one variable acquisition module；This variable acquisition module includes being electrically connected toThe constant-current source of one node, clamp circuit and electric charge transmitting-receiving testing circuit, and the secondary nodal point of ground connection；

During the detection for an electrode, the first of the primary nodal point elder generation electrode electrically connected of described variable acquisition moduleEnd, and the second end of secondary nodal point electrode electrically connected, after collecting the first self-capacitance variable, the first of variable acquisition moduleNode electrically connects the second end of this electrode, and the first end of secondary nodal point electrode electrically connected again, to gather the second self-capacitance changeAmount；

The current potential of institute's electrode electrically connected one end is limited to constant potential by described clamp circuit, and described constant-current source is to being electrically connected electricityPole provides constant current；Described electric charge transmitting-receiving testing circuit changes to this electrode output electricity because of the self-capacitance of its electrode electrically connectedLotus, and detect electric charge output, quantifying electric charge output is self-capacitance variable；

Described clamp circuit includes an operational amplifier, and the constant potential that this clamp circuit is limited is by this operational amplifier forwardThe input voltage of input controls；

Described electric charge transmitting-receiving testing circuit includes the described operational amplifier being used as clamp circuit, is connected electrically in this operational amplifierElectric charge transmitting-receiving electric capacity between inverting input and outfan, and electrically connect the alternating current-direct current of the outfan of described operational amplifierTransform subblock；

The current output terminal of described constant-current source and the inverting input of operational amplifier are both electrically connected with in primary nodal point.

Self-capacitance sensing device for touch screen the most according to claim 1, it is characterised in that:

The constant potential that the current potential of institute's electrode electrically connected one end is limited by described clamp circuit is V1, and described constant-current source is to being electrically connectedThe constant current that receiving electrode provides is I, then it suffices that V1/I=R, R are clamp circuit and constant-current source institute electrode electrically connectedResistance.

Self-capacitance sensing device for touch screen the most according to claim 1, it is characterised in that:

Reset switch also it is electrically connected with between the two ends of described electric charge transmitting-receiving electric capacity.

Self-capacitance sensing device for touch screen the most according to claim 1, it is characterised in that:

At least one drift angle cut formation straightway hypotenuse of described electrode, thus electrode is processed to the rectangle with hypotenuseElectrode.

Self-capacitance sensing device for touch screen the most according to claim 1, it is characterised in that:

At least one drift angle cut formation circular arc line segment limit of described electrode, thus electrode is processed to the square with arc-shaped edgesShape electrode.

Self-capacitance sensing device for touch screen the most according to claim 1, it is characterised in that:

At least one limit of described electrode is machined with at least two groove, forms double wedge between two adjacent two grooves, thus electricPole is processed to the rectangular electrode with toothed edge.

Self-capacitance sensing device for touch screen the most according to claim 1, it is characterised in that:

Described electrode tin indium oxide, wire netting or carbon nanomaterial are made.

Self-capacitance sensing device for touch screen the most according to claim 1, it is characterised in that:

Also include that with resins synthesis thin-film material or the substrate made with glass, described electrode adheres on the substrate.

Self-capacitance sensing device for touch screen the most according to claim 1, it is characterised in that:

Described self-capacitance sensing device is arranged in LCDs；This LCDs includes the first crystal liquid substrate and the second liquidBrilliant substrate, and be clipped in the liquid crystal material between the first crystal liquid substrate and the second crystal liquid substrate, pixel electrode, chromatic filter layer andBlack matrix；

Described electrode is attached to upper strata or the lower floor of described first crystal liquid substrate, or the upper strata of the second crystal liquid substrate or underLayer.

Self-capacitance sensing device for touch screen the most according to claim 1, it is characterised in that:

Described self-capacitance change detection unit includes a set of variable acquisition module；This set variable acquisition module is controllably according to settingSequential be sequentially connected electrically described each electrode, i.e. timesharing ground electrically connects each electrode to complete the change inspection of the self-capacitance to each electrodeSurvey.

The 11. self-capacitance sensing devices for touch screen according to claim 1, it is characterised in that:

The quantity of described variable acquisition module is less than the quantity of electrode；Each variable acquisition module controllably depends on according to the sequential setThe secondary partial electrode electrically connected one to one in all electrodes, i.e. timesharing electrically connect each electrode in subregional to complete each electrodeSelf-capacitance change-detection.

The 12. self-capacitance sensing devices for touch screen according to claim 1, it is characterised in that:

Described variable acquisition module electrically connects described electrode one to one.

The 13. self-capacitance sensing devices for touch screen according to claim 1, it is characterised in that:

Described self-capacitance sensing device is arranged in LCDs；This LCDs is by display driver circuit chip controls；Described self-capacitance change detection unit is integrated in described display driver circuit chip.

The 14. self-capacitance sensing devices for touch screen according to claim 1, it is characterised in that:

Also include coordinating detection module；

Described self-capacitance sensing device is arranged in LCDs；This LCDs is by display driver circuit control；

Described coordination detection module electrically connects described self-capacitance change detection unit and display driver circuit, to make self-capacitance changeDetector unit and display driver circuit are the most at times and/or subregion completes respective function.

15. 1 kinds of touch points coordinate data processing method, based on self-capacitance sensing device, this self-capacitance sensing device includes at leastOne electrode；Described electrode includes the first end in the first direction and the second end；Described each electrode is along being perpendicular to the of first directionSequentially arrange in two directions, it is characterised in that:

Following steps are performed for each electrode,

A. at the first end electrical connection constant-current source, clamp circuit and the electric charge transmitting-receiving testing circuit of electrode, by the second end of this electrodeGround connection；Described constant-current source is to the electric current of electrode output constant current value；Described clamp circuit makes one end of institute's electrode electrically connectedCurrent potential is defined in constant potential；Described electric charge transmitting-receiving testing circuit can output charge or receive electric charge, and it is defeated to detect electric chargeOutput or reception amount, quantifying electric charge output is self-capacitance variable；

B. electric charge transmitting-receiving testing circuit has detected whether that electric charge exports；

If there being electric charge to export, then quantifying electric charge output is the first self-capacitance variable, performs step C subsequently；

Export without electric charge, directly perform step E；

C. at the second end electrical connection constant-current source, clamp circuit and the electric charge transmitting-receiving testing circuit of electrode, by the first end of this electrodeGround connection；

D. electric charge transmitting-receiving testing circuit quantifies electric charge output is the second self-capacitance variable；

E. the self-capacitance change-detection for described electrode terminates；

Based on above step A to E, described method comprises the steps,

F., when a touch points makes the self-capacitance of K electrode change, get and relate to the K of this touch points to self-capacitanceVariable quantity, i.e. 2K self-capacitance variable；

G. maximum in 2K self-capacitance variable one is selected；

This maximum self-capacitance variable said electrode is the T electrode in a second direction, and this maximum self-capacitance variable is instituteStating the first self-capacitance variable of T electrode, i.e. DTU, another self-capacitance variable of T electrode is the of this electrodeTwo self-capacitance variable, i.e. DTV,

Thus the T electrode respective first self-capacitance variable of two lateral electrodes in a second direction is D(T+1 respectively) U, D(T+2)U ..., D(T+W1) U, and D(T-1) U, D(T-2) U ..., D(T-W2) U；Second self-capacitance variable is D(T+1 respectively) V, D(T+2) V ..., D(T+W1) V, and D(T-1) V, D(T-2) V ..., D(T-W2) V, W1+W2+1=K；

If the length that the most each electrode is in the first direction is X0, length in a second direction is Y0, then touch points described in step ACoordinate Y is in a second direction,

,

Lateral coordinates X in the first direction of touch points described in step A is,

。

16. touch points coordinate data processing method according to claim 15, it is characterised in that:

Constant-current source described in step A is I to the constant current value that electrode exports, and described clamp circuit makes one end of institute's electrode electrically connectedCurrent potential limit constant potential be V1, then it suffices that V1/I=R, R are clamp circuit and constant-current source institute electrode electrically connectedResistance.