CN104461210A - Method for detecting touch point on film input device - Google Patents

Abstract

A method for detecting touch points on a thin film input device. When the touch point is detected on the thin film element of the thin film input device, the longitudinal induction line and the transverse induction line on the thin film element are charged by a direct current voltage source firstly under the control of a processor included in the thin film input device, then the longitudinal induction line to be detected is grounded, the rest longitudinal induction lines are all in floating connection, the longitudinal induction line to be detected is in floating connection with the transverse induction line to be detected, the rest transverse induction lines are all hung on the induction resistor to be coupled with the direct current voltage source, so that when a plurality of touched touch points appear, the crossed points of the touched induction lines are prevented from being influenced by the parallel connection of the induction resistors to reduce the resistance value and are mistakenly judged as non-touched points, and the high cost and the large integrated circuit area brought by the induction resistors with high resistance value can be saved.

Description

Film input media detects the method for touch point

Technical field

The present invention discloses a kind of method detecting touch point on film input media, particularly relates to that a kind of reason inductive reactance is in parallel and reduce resistance and cause current potential too high and be mistaken for not touched method to make multiple touched line of induction cross-point without the need to crossing the inductive reactance of the high value part line of induction on film input media by dynamic carry.

Background technology

Containing the carbon combined silver serous coat of pure carbon because cheap many next relative to fine silver serous coat of its material cost, therefore following very likely as the main material manufactured when keyboard is the various film input media led.But; due to carbon combined silver serous coat resistance value than fine silver serous coat resistance value come large on very many; if therefore the induced electricity resistance that uses of film input media is large not; when multiple key is pressed; its inductive reactance can obviously reduce resistance by parallel connection; and make with the film input media of carbon combined silver serous coat manufacture when by use, often have and judge the situation generation that the button be pressed is the button be not pressed by accident.

Refer to Fig. 1, it is generally with the schematic equivalent circuit of sheet resistance in a film input media 100 of carbon silver slurry hybrid films manufacture.As shown in Figure 1, film input media 100 contains thin-film component 101 and a not shown processor.Thin-film component 101 contains at least many longitudinal induction line SL1, SL2 and many transvercal induction line RL1, RL2, RL3, wherein longitudinal induction line SL1 includes the resistance Rs11 of multiple series connection, Rs12, Rs13, Rs14, longitudinal induction line SL2 includes the resistance Rs21 of multiple series connection, Rs22, Rs33, Rs24, transvercal induction line RL1 includes the resistance Rr11 of multiple series connection, Rr12, Rr13, transvercal induction line RL2 includes the resistance Rr21 of multiple series connection, Rr22, Rr23, transvercal induction line RL3 includes the resistance Rr31 of multiple series connection, Rr32, Rr33.As shown in Figure 1, longitudinal induction line SL1, SL2 and transvercal induction line RL1, RL2, RL3 interlock six cross-points totally, and the current potential on these cross-points can be used to judge whether these cross-points are pressed, and determine the correct touch point of user to film input media 100 according to this.In addition, when not being pressed, can not contact each other between each transvercal induction line with each longitudinal induction line, otherwise, when the cross-point between a transvercal induction line and a longitudinal induction line is pressed, can contact with each other between this transvercal induction line and this longitudinal induction line.In addition, horizontal interrupteur SW R1, SWR2 shown in Fig. 1, SWR3, longitudinal switch SWL1, SWL2 and inductive reactance Rpu1, Rpu2, Rpu3, Rpu4 etc. are all contained in above-mentioned processor.

Film input media 100 detects the mode of touch point mainly: (1) is by one end ground connection of single longitudinal induction line (the longitudinal induction line SL1 such as shown in Fig. 1), so that this longitudinal induction line is discharged, and other longitudinal induction lines all pass through an inductive reactance (such as longitudinal induction line SL2 is by the inductive reactance Rpu4 of longitudinal switch SWL2 institute carry) and carry in a direct current voltage source V DD; (2) all transvercal induction lines (transvercal induction line RL1, RL2, RL3 such as shown in Fig. 1) staggered with the longitudinal induction line that is grounded in (1) all pass through inductive reactance (such as transvercal induction line RL1, RL2, RL3 each via horizontal interrupteur SW R1, SWR2, SWR3 inductive reactance Rpu1, Rpu2, Rpu3 of respective carry) and carry in direct voltage source VDD.By step (1), step (2), all touch points on this single longitudinal induction line can be detected, and sequentially step (1), step (2) can be implemented on other single longitudinal induction line again, with all touch points on complete grasp film input media 100.All suppose in this official documents and correspondence the resistance value of the inductive reactance of each line of induction institute carry all equal be an induced electricity resistance Rpu, that is the resistance value of inductive reactance Rpu1, Rpu2, Rpu3, Rpu4 is all equal is induced electricity resistance Rpu.

Step (1) will be described in more detail as follows with the embodiment of step (2).When longitudinal induction line SL1 is detected, if the current potential on a transvercal induction line (such as transvercal induction line RL1) staggered is with it detected lower than a critical pressing potential vt h (it can be the electronegative potential representing logical value 0), the cross-point then representing this longitudinal induction line and this transvercal induction line is pressed and makes this longitudinal induction line brought into temporary contact in this transvercal induction line, and makes the current potential of this cross-point be discharged to lower than this critical by piezoelectric position because of the earth terminal connected by this longitudinal induction line; Otherwise, if the current potential on this transvercal induction line is detected not critical by piezoelectric position lower than this, the cross-point then representing this longitudinal induction line and this transvercal induction line makes this longitudinal induction line now not be contacted with this transvercal induction line because of not being pressed, make the current potential of this cross-point approximate greatly the current potential of direct voltage source VDD.

The desirable minimum resistance of inductive reactance Rpu1 can be derived by following process.Now horizontal interrupteur SW R1, SWR2, SWR3 are all switched to short circuit, and supposing that longitudinal switch SWL1 is switched to an earth terminal and longitudinal induction line SWL1 can be detected, longitudinal switch SW2 is switched to be coupled to direct voltage source VDD by inductive reactance Rpu4 simultaneously.All suppose in this official documents and correspondence this critical be 1/3rd of the current potential of direct voltage source VDD by piezoelectric position, and the resistance value of all equivalent resistances (namely lateral resistance Rr11, Rr12, Rr13, Rr21, Rr22, Rr23, Rr31, Rr32, Rr33 and longitudinal electrical resistance Rs11, Rs12, Rs13, Rs14, Rs21, Rs22, Rs23, Rs24) of hypothesis in this official documents and correspondence on these transvercal induction lines and these longitudinal induction lines is all R.If at a time, cross-point V1 between longitudinal induction line Rs11 and transvercal induction line Rr11 is pressed, then in observation by direct voltage source VDD by inductive reactance Rpu1, horizontal interrupteur SW R1, lateral resistance Rr11, longitudinal electrical resistance Rs11, longitudinal switch SWL1, again to the path of earth terminal, the resistance value Rpu that can find to meet inductive reactance Rpu1 is that minimum equation is as follows:

$\frac{\mathrm{Rr}11+\mathrm{Rs}11}{\mathrm{Rpu}1+\mathrm{Rr}11+\mathrm{Rs}11}*\mathrm{VDD}=\mathrm{Vth}\⇒\frac{2R}{\mathrm{Rpu}+2R}*\mathrm{VDD}=\frac{1}{3}*\mathrm{VDD}---\left(1\right)$

By (1) through conversion, can find that equation is as follows:

Rpu=4R (2)

That is, when cross-point V1 is pressed, if induced electricity resistance Rpu is at least also 4R.Next the situation when cross-point V1 and cross-point V2 (cross-point of longitudinal induction line SL1 and transvercal induction line RL2) is pressed simultaneously is taken another look at.Utilize Ampère law can try to achieve the equation of the electric current flowing into cross-point V1 as follows:

$\frac{(\mathrm{VDD}-V_{V1})}{\mathrm{Rpu}2+\mathrm{Rr}21+\mathrm{Rs}12}+\frac{(\mathrm{VDD}-V_{V1})}{\mathrm{Rpu}1+\mathrm{Rr}12}=\frac{V_{V1}}{\mathrm{Rr}11}\⇒\frac{(\mathrm{VDD}-V_{V1})}{\mathrm{Rpu}+2R}+\frac{(\mathrm{VDD}-V_{V1})}{\mathrm{Rpu}+R}=\frac{V_{V1}}{R}---\left(3\right)$

If judge that cross-point V2 is pressed, then the current potential detected by line of induction RL2 is less than critical pressing potential vt h, can obtain equation as follows:

$\frac{(\mathrm{VDD}-\mathrm{Vth})}{\mathrm{Rpu}1}=\frac{(\mathrm{Vth}-V_{V1})}{\mathrm{Rr}21+\mathrm{Rs}12}\⇒\frac{(\mathrm{VDD}-\frac{1}{3}\mathrm{VDD})}{\mathrm{Rpu}}=\frac{(\frac{1}{3}\mathrm{VDD}-V_{V1})}{2R}---\left(4\right)$

By equation (3) and (4) after separating simultaneous equations, can find that its inequality is as follows:

Rpu>8R (5)

In other words, when the current potential that the transvercal induction line that arrives corresponding to cross-point detects lower than critical by piezoelectric position time, cross-point just can by correct judgement for being pressed, but the current potential that will meet cross-point V1 and the line of induction RL1 and RL2 corresponding to cross-point V2 all will lower than critical by piezoelectric position, therefore induced electricity resistance Rpu is again toward raising, but such practice also significantly can improve integrated circuit area and the cost of film input media 100.

Summary of the invention

During in order to overcome the touch point in prior art on sensing film input media, the high resistance of the sensed resistance of meeting widens the problem of integrated circuit area and cost, the invention discloses a kind of method detecting touch point on film input media.

Detecting in the method for touch point on a film input media disclosed in the present invention, this film input media comprises multiple longitudinal induction line and multiple transvercal induction line; Each longitudinal induction line includes longitudinal electrical resistance and a longitudinal switch of multiple series connection; The mode that this each longitudinal induction line just contacts with each other when being pressed with cross-point crisscrosses each transvercal induction line; Each transvercal induction line includes the lateral resistance of multiple series connection, an inductive reactance and a horizontal switch; This horizontal switch is coupled between the plurality of lateral resistance and this inductive reactance, and this inductive reactance is coupled between this horizontal switch and a voltage source.It is as follows that the method detecting touch point disclosed in the present invention on film input media comprises step: the plurality of longitudinal induction line and the plurality of transvercal induction line are charged to one first current potential by (a); B this longitudinal switch on this each longitudinal induction line is switched to open circuit by (), with this each longitudinal induction line of suspension joint; C one first longitudinal induction line in the plurality of longitudinal induction line discharges by (); D horizontal switching at least one first transvercal induction line in the plurality of transvercal induction line is extremely opened a way, with this at least one first transvercal induction line of suspension joint by (); E () detects the current potential on this at least one first transvercal induction line; And (f) when detect the current potential on one first transvercal induction line on this at least one first transvercal induction line lower than one critical by piezoelectric position time, judge current potential be pressed lower than one first cross-point between this critical this first transvercal induction line by piezoelectric position and this first longitudinal induction line.

Accompanying drawing explanation

Fig. 1 is generally with the schematic equivalent circuit of sheet resistance in a film input media of carbon silver slurry hybrid films manufacture.

Fig. 2 is for according to the process flow diagram of method detecting touch point disclosed in one embodiment of the invention on film input media.

Fig. 3 and Fig. 4 for implement shown in Fig. 2 on film input media, detect the method for touch point time, the operational overview schematic diagram of the film input media shown in Fig. 1.

[symbol description]

100 film input medias

101 thin-film components

SWL1, SWL2 longitudinal switch

The horizontal switch of SWR1, SWR2, SWR3

VDD direct voltage source

Rpu1, Rpu2, Rpu3, Rpu4 inductive reactance

RL1, RL2, RL3 transvercal induction line

SL1, SL2 longitudinal induction line

V1, V2, V3 cross-point

Rr11, Rr12, Rr13, Rr21, resistance in series

Rr22、Rr23、Rr31、Rr32、Rr33、

Rs11、Rs12、Rs13、Rs14、Rs21、

Rs22、Rs23、Rs24

300,302,304,306,308, step

310、312、314、316、318

Vth is critical by piezoelectric position

Embodiment

During in order to overcome the touch point in prior art on sensing film input media 100, the high resistance of the sensed resistance of meeting widens the problem of integrated circuit area and cost, the invention discloses a kind of method detecting touch point on film input media, and the method can be applicable to the film input media 100 shown in Fig. 1.

Refer to Fig. 2, cause the indefinite of record in order to avoid obscuring diagram, diagram afterwards will not mark thin-film component 101 separately, so must be considered as in each figure of Graphic films input media 100 after thin-film component 101 is present in.It is as follows that its method comprises step:

Step 300: start.

Step 302: transvercal induction lines all on film input media 100 and all longitudinal induction lines are charged to one first current potential.

Step 304: by the longitudinal induction line ground connection for detecting, and by all the other all longitudinal induction lines all suspension joints beyond the longitudinal induction line for detecting.

Step 306: by the transvercal induction line suspension joint of a part.

Step 308: whether judge by the current potential on this parts transversely line of induction of suspension joint lower than critical pressing potential vt h; When having the transvercal induction line of current potential lower than critical pressing potential vt h in this parts transversely line of induction, lower than the transvercal induction line of critical pressing potential vt h, step 310 is performed to current potential; When having the transvercal induction line of current potential not lower than critical pressing potential vt h in this parts transversely line of induction, lower than the transvercal induction line of critical pressing potential vt h, step 312 is not performed to current potential.

Step 310: judge current potential lower than the transvercal induction line of critical pressing potential vt h and for the cross-point between the longitudinal induction line that detects as touch point.

Step 312: judge current potential not lower than the transvercal induction line of critical pressing potential vt h and for the cross-point between the longitudinal induction line that detects as non-touch point.

Step 314: confirm all transvercal induction lines whether all tested current potential staggered with the longitudinal induction line for detecting; If with all tested current potential of all transvercal induction lines that the longitudinal induction line for detecting is staggered, then perform step 318; If with the not yet all tested current potential of all transvercal induction lines that the longitudinal induction line for detecting is staggered, then perform step 316.

Step 316: all transvercal induction lines and all longitudinal induction lines beyond the longitudinal induction line detected all are charged to this first current potential, and then perform step 306, and with other transvercal induction lines not being judged overpotential in step 308 at least partially for object carrys out suspension joint, with in time again arriving step 308, with these by the transvercal induction line of suspension joint for object detects current potential.

Step 318: be confirmed whether to be detected all longitudinal induction lines; If be detected all longitudinal induction lines, then perform step 300; If be not yet detected all longitudinal induction lines, then to choose one in not yet tested residue longitudinal induction line, and then perform step 302, make when again performing step 304, the single residue longitudinal induction line be selected in step 318 is as being grounded and detected object.

Please consult Fig. 3 and Fig. 4 in addition.Fig. 3 and Fig. 4 for implement shown in Fig. 2 on film input media, detect the method for touch point time, the operational overview schematic diagram of film input media 100, to facilitate the method disclosed in key drawing 2, wherein cross-point V1, V2, V3 is pressed the same time.

In step 302, can first all longitudinal induction line SL1, SL2 and all transvercal induction line RL1, RL2, RL3 be first charged to one first current potential (being such as considered as the current potential of logical one by film input media 100), the mode of wherein charging can comprise and longitudinal switch SWL1, SWL2 switched to short circuit and is directly connected in direct voltage source VDD and horizontal interrupteur SW R1, SWR2, SWR3 is switched to short circuit and is coupled to direct voltage source VDD each via inductive reactance Rpu1, Rpu2, Rpu3.Thus, the current potential on each transvercal induction line and each longitudinal induction line will close to the current potential of direct voltage source VDD.Note that longitudinal switch SWL1, SWL2 and horizontal interrupteur SW R1, SWR2, SWR3 all have by a processor control after direct with short-circuit condition be directly connected in direct voltage source VDD ability, with short-circuit condition each via inductive reactance Rpu1, Rpu2, Rpu3 be coupled to direct voltage source VDD ability, be connected to the ability of an earth terminal with short-circuit condition and make the ability of the line of induction by suspension joint at its place with open-circuit condition; In addition, because longitudinal switch SWL1, SWL2 possess identical function with horizontal interrupteur SW R1, SWR2, SWR3, therefore greatly can reduce the complexity of design processor, the processor that circulation market is applicable to even can be selected to implement the method detecting touch point on film input media of the present invention.

Step 304 object is that the single longitudinal induction line making to be detected is grounded in advance, and makes remaining longitudinal induction line and all transvercal induction lines all by suspension joint; As shown in Figure 3, can be grounded by selection in advance at this hypothesis longitudinal induction line SL1 and be used as detected longitudinal induction line, remaining longitudinal induction line SL2 then can at this by suspension joint (such as receive earth terminal by longitudinal switch SL1 with short-circuit condition, and longitudinal switch SL2 switched to open-circuit condition).Please note, by step 304 in the process of step 314, only having a longitudinal induction line with the time is grounded with detected, and to change other longitudinal induction line, then need to confirm that all transvercal induction lines crossing with this longitudinal induction line be grounded are detected complete in a step 314, an other longitudinal induction line could be changed to carry out the process of step 304 to step 314 in the confirmation process of step 318.

In step 306, can by selecting the transvercal induction line of a part to carry out suspension joint in transvercal induction line RL1, RL2, RL3; As shown in Figure 3, suspension joint (such as horizontal interrupteur SW RL1, SWRL3 being switched to open circuit) is selected at this hypothesis transvercal induction line RL1, RL3, and remaining transvercal induction line RL2 then keeps the state that be charged to this first current potential identical with step 302, such as transvercal induction line RL2 by horizontal switch RL2 is switched to short circuit, and by state that inductive reactance Rpu2 and direct voltage source VDD couple.

In step 308, need judge at present by the current potential on transvercal induction line RL1, RL3 of suspension joint whether lower than critical pressing potential vt h.In the step 310, in transvercal induction line RL1, RL3, current potential is lower than the transvercal induction line of critical pressing potential vt h, the cross-point represented between itself and longitudinal induction line SL1 is pressed at present, cause the longitudinal induction line SL1 be originally grounded by the voltage charged to discharge and lower than critical pressing potential vt h; In like manner, in step 312, in transvercal induction line RL1, RL3, current potential is not lower than the transvercal induction line of critical pressing potential vt h, the cross-point represented between itself and longitudinal induction line SL1 is not pressed at present, this first current potential after causing the longitudinal induction line SL1 be originally grounded by the voltage charged still to keep its charging, and not lower than critical pressing potential vt h.

After the current potential of all transvercal induction lines of current suspension joint being judged in step 308,310,312, need in a step 314 first to confirm whether all transvercal induction lines staggered with the longitudinal induction line SL1 of current ground connection have been judged complete.Not yet be judged complete at this owing to being also left transvercal induction line SL2, therefore need to perform step 316.In step 316, except the longitudinal induction line SL1 of current ground connection, need remaining all longitudinal induction line SL2 and all transvercal induction line RL1, RL2, RL3 all to charge back this first current potential, think that the current potential judgement of next stage is prepared, and then execution step 304.

When again getting back to step 304, longitudinal induction line SL1 can be grounded again (to be needed by clear clean because of the current potential be pressed a little in previous and transvercal induction line RL1 or RL3, namely reset), and the longitudinal induction line SL2 that residue is not grounded also can again by suspension joint.

When again getting back to step 306, other transvercal induction line selections longitudinal induction line SL1 can be selected under ground state get its part or all, and as performing the object of step 308 and 310/312.As shown in Figure 4, be not selected under longitudinal induction line SL1 is ground state owing to being only left transvercal induction line RL2 at this, so time then using transvercal induction line RL2 as perform step 308,310/312 object, whether touched to judge the cross-point V2 between transvercal induction line RL2 and longitudinal induction line SL1; Such as horizontal interrupteur SW RL1, SWRL3 can be switched to separately short circuit to be coupled to direct voltage source VDD each via inductive reactance Rpu1, Rpu3, and horizontal interrupteur SW RL2 be switched to open circuit with suspension joint transvercal induction line SL2.

When then getting back to step 314, due under the ground state of longitudinal induction line SL1, all transvercal induction line RL1, RL2, RL3 are determined overpotential all, therefore can continue to perform step 318; Separately, if not, then again step 316 can be got back to, till all transvercal induction lines all tested current potential of longitudinal induction line SL1 under ground state.

In step 318, due under the ground state of longitudinal induction line SL1, all transvercal induction line RL1, RL2, RL3 is determined overpotential all, therefore the process (but still the principle once only having a longitudinal induction line to be grounded need be maintained) that a longitudinal induction line be not grounded (such as longitudinal induction line SL2) carrys out implementation step 306-316 can be changed again in addition, until when all longitudinal induction lines are grounded separately, till the current potential of all transvercal induction lines is judged overpotential all, accurately to grasp the position of current all touch points on film input media 100.

Within step 306, when choosing a part of transvercal induction line that will be performed step 308-312, can choose arbitrarily one, many or or even whole transvercal induction line as object, as long as what choose is transvercal induction line not yet tested under the longitudinal induction line be grounded at present, until whether the cross-point between all transvercal induction lines and the longitudinal induction line be grounded at present was all identified is touch point.

In addition, when performing step 318, selected next is used for the longitudinal induction line of ground connection and also can selects arbitrarily, so long as not ground connection verified longitudinal induction line before, until all longitudinal induction lines be all grounded and cross-point between itself and all transvercal induction lines whether be all identified be touch point.

The applicable film input media of method shown in Fig. 2 in the quantity of transvercal induction line and longitudinal induction line, not by the restriction shown in Fig. 1, Fig. 3, Fig. 4.That is, the present invention is applied to dissimilar film input media in the method that Fig. 2 discloses, must embodiments of the invention be considered as.

Fig. 3 due to horizontal SWR1 and SWR3 be open circuit, therefore the current potential detected by line of induction RL3 is cross-point V2 is pressed current potential V _v2if will be judged to be pressed, the touched current potential V of its cross-point V2 _v2will lower than critical by piezoelectric position , it is as follows to try to achieve equation:

$\frac{\mathrm{Rs}12+\mathrm{Rs}11}{\mathrm{Rpu}2+\mathrm{Rr}21+\mathrm{Rs}12+\mathrm{Rs}11}\×\mathrm{VDD}=\mathrm{Vth}\⇒\frac{2R}{\mathrm{Rpu}+3R}\×\mathrm{VDD}=\frac{1}{3}\×\mathrm{VDD},$ Can try to achieve

Rpu=3R (6)

And the touched current potential V of cross-point V1 _v1for being the current potential detected by line of induction RL1, can be tried to achieve as follows by voltage law:

$\frac{\mathrm{Rs}11}{\mathrm{Rpu}2+\mathrm{Rr}21+\mathrm{Rs}12+\mathrm{Rs}11}\×\mathrm{VDD}\⇒\frac{R}{\mathrm{Rpu}+3R}\×\mathrm{VDD}---\left(7\right)$

(6) are substituted into (7) formula, the touched current potential V of cross-point V1 can be obtained _v1for be less than critical pressing potential vt h.

As long as induced electricity resistance Rpu is greater than three times of R, the current potential that the line of induction RL1 and RL3 detects all can be judged to be logical zero, but thin-film component 101 can not for being uniformly distributed in its resistance value of manufacture process, therefore induced electricity resistance Rpu should be Selection radio 3*R height comparatively suitably, based on thin-film component 101 the most loop resistance:

Rpu=Rr31+Rr32+Rs23+Rs22+Rs21=5R (8)

Fig. 4 is because horizontal SWR2 is for opening a way, therefore the current potential detected by line of induction RL2 is cross-point V2, first asks cross-point V1 current potential V _v1, the current equations flowing into cross-point V1 is as follows:

$\frac{\mathrm{VDD}-V_{V1}}{\mathrm{Rpu}3+\mathrm{Rs}31+\mathrm{Rs}13+\mathrm{Rs}12}+\frac{\mathrm{VDD}-V_{V1}}{\mathrm{Rpu}1+\mathrm{Rr}11}=\frac{V_{V1}}{\mathrm{Rs}11}\⇒\frac{\mathrm{VDD}-V_{V1}}{\mathrm{Rpu}+3R}+\frac{\mathrm{VDD}-V_{V1}}{\mathrm{Rpu}+R}=\frac{V_{V1}}{R}---\left(9\right)$

(8) are substituted into (9) the touched current potential V of cross-point V1 can be tried to achieve _v1for and then the touched current potential V of cross-point V2 can be tried to achieve _v2for $\frac{\mathrm{Rs}12}{\mathrm{Rpu}3+\mathrm{Rr}31+\mathrm{Rs}13+\mathrm{Rs}12}(\mathrm{VDD}-V_{V1})+V_{V1}=\frac{R}{8R}\×\frac{24}{31}\mathrm{VDD}+\frac{7}{31}\mathrm{VDD}=\frac{30}{31}*\frac{1}{3}\mathrm{VDD},$ Also be less than critical pressing potential vt h, therefore be also determined to be logical zero.

The invention discloses a kind of method detecting touch point on film input media.By comparing (5) and (8) learn the method disclosed in the present, the resistance value of inductive reactance in prior art not only can be avoided too high and strengthen the problem of manufacturing cost and integrated circuit area, when also can avoid pressing multiple touch point, the line of induction cross-point be pressed is subject to the problem of the in parallel and impact that reduces of inductive reactance and the non-touch point of misjudged one-tenth simultaneously.In addition, because critical pressing potential vt h judges in suspension joint mode, under having lacked inductive reactance and can increasing the condition of the velocity of discharge, and then the judgement time can be shortened.

Claims (6)

1. one kind is detected the method for touch point on a film input media, this film input media comprises multiple longitudinal induction line and multiple transvercal induction line, each longitudinal induction line includes longitudinal electrical resistance and a longitudinal switch of multiple series connection, the mode that this each longitudinal induction line just contacts with each other when being pressed with cross-point crisscrosses each transvercal induction line, each transvercal induction line includes the lateral resistance of multiple series connection, one inductive reactance, and a horizontal switch, this horizontal switch is coupled between the plurality of lateral resistance and this inductive reactance, and this inductive reactance is coupled between this horizontal switch and a voltage source, the method comprises:

A the plurality of longitudinal induction line and the plurality of transvercal induction line are charged to one first current potential by ();

B this longitudinal switch on this each longitudinal induction line is switched to open circuit by (), with this each longitudinal induction line of suspension joint (float);

C one first longitudinal induction line in the plurality of longitudinal induction line discharges by ();

D horizontal switching at least one first transvercal induction line in the plurality of transvercal induction line is extremely opened a way, with this at least one first transvercal induction line of suspension joint by ();

E () detects the current potential on this at least one first transvercal induction line; And

(f) when detect the current potential on one first transvercal induction line on this at least one first transvercal induction line lower than one critical by piezoelectric position time, judge current potential be pressed lower than one first cross-point between this critical this first transvercal induction line by piezoelectric position and this first longitudinal induction line.

2. the method for claim 1, also comprises:

(g) when detect the current potential on one first transvercal induction line on this at least one first transvercal induction line not lower than this critical by piezoelectric position time, judge current potential be not pressed lower than one second cross-point between this critical this first transvercal induction line by piezoelectric position and this first longitudinal induction line.

3. the method for claim 1, also comprises:

H () horizontal switching over by this at least one first transvercal induction line is to short circuit;

(i) by the plurality of transvercal induction line except this at least one the first transvercal induction line at least one second transvercal induction line on horizontal switching over to open circuit, with this at least one second transvercal induction line of suspension joint;

J () detects the current potential on this at least one second transvercal induction line; And

(k) when detect the current potential on one second transvercal induction line on this at least one second transvercal induction line lower than this critical by piezoelectric position time, judge current potential be pressed lower than one the 3rd cross-point between this critical this second transvercal induction line by piezoelectric position and this first longitudinal induction line.

4. method as claimed in claim 3, also comprises:

L the plurality of transvercal induction line and the plurality of longitudinal induction line, after the situation whether all cross-points of the plurality of transvercal induction line and this first longitudinal induction line are pressed is determined all, are charged to this first current potential by ();

M this longitudinal switch on this each longitudinal induction line is switched to open circuit by (), with this each longitudinal induction line of suspension joint;

N one second longitudinal induction line of the plurality of longitudinal induction line discharges by ();

O horizontal switching at least one the 3rd transvercal induction line in the plurality of transvercal induction line is extremely opened a way, with this at least one the 3rd transvercal induction line of suspension joint by ();

P () detects the current potential on this at least one the 3rd transvercal induction line; And

(f) when detect the current potential on one the 3rd transvercal induction line on this at least one the 3rd transvercal induction line lower than this critical by piezoelectric position time, judge current potential be pressed lower than one the 4th cross-point between this critical the 3rd transvercal induction line by piezoelectric position and this second longitudinal induction line.

5. method as claimed in claim 4, also comprises:

(o) when detect the current potential on one the 3rd transvercal induction line on this at least one the 3rd transvercal induction line not lower than this critical by piezoelectric position time, judge current potential be not pressed lower than one the 5th cross-point between this critical the 3rd transvercal induction line by piezoelectric position and this second longitudinal induction line.

6. the method for claim 1, wherein a resistance value of this inductive reactance is based on a most loop resistance of this film input media, and the resistance value of this inductive reactance adjustment or select and be directly proportional to the number being judged the cross-point be pressed.