CN103677478B - A kind of resistive touch screen and button multiplexing circuit and detection method - Google Patents

Abstract

The present invention provides a kind of resistive touch screen and button multiplexing circuit and detection method thereof, this circuit includes at least one key circuit being connected between a lead terminal of X-direction and a lead terminal of Y-direction, and described key circuit includes resistance and the switch being connected in series；Testing circuit, for applying voltage on two lead terminals of X-direction, determines coordinate voltage value V of X-direction by the two of Y-direction lead terminals_senx, two lead terminals in the Y direction apply voltage, are determined coordinate voltage value V of Y-direction by the two of X-direction lead terminals_seny, according to V_senxAnd V_senyDetermine position on resistive film, the touch point or determine whether to press switch.The present invention can support touch screen and button detection simultaneously, has higher accuracy of detection and stronger capacity of resisting disturbance.

Description

A kind of resistive touch screen and button multiplexing circuit and detection method

Technical field

The present invention relates to touch screen technology field, particularly relate to a kind of resistive touch screen and button multiplexing circuit and detection Method.

Background technology

Touch screen (Touch panel) is also called touch panel, is a kind of vicarious liquid crystal indicator.When the most tactile Head, finger tip etc. are when the position that touch screen shows a certain prompting figure presses touch screen, and touch screen can sense generation The touch point pressed, and substitute various mechanical operations with the position, touch point sensed or change in location trend.

Resistive touch screen is a kind of more conventional touch screen.Resistive touch screen generally has the indium of two homogeneous conductive Tin-oxide (ITO) semiconductor layer, also referred to as resistive film, utilize medium to isolate between two ITO and support.Two ITO layer are divided Other to being applied to represent X-direction coordinate and the Y-direction coordinate of position, touch point, therefore two ITO layer are called again X-plane and Y Plane.

After touching, X-plane contacts in touch point with Y plane.Now, i.e. can detect that based on electric resistance partial pressure principle The X-direction coordinate of touch point and the position of Y-direction coordinate, i.e. touch point.

Fig. 1 is resistive touch screen equivalent-circuit model and Cleaning Principle block diagram, and wherein Rx1, Rx2 are that X-plane is touched The separate two sections of resistance of point, Ry1, Ry2 are the separate two sections of resistance of Y plane touched point, and Rtouch is two plane contact Contact resistance, Rcontx, Rconty are the lead resistance at two ITO layer edges.XP, XN are two leading-out terminals of X-plane, YP, YN are two leading-out terminals of Y plane.The position coordinates magnitude of voltage of the both direction that foundation electric resistance partial pressure principle obtains is:

$V_{\mathrm{senx}}=V_{\mathrm{ref}}\frac{R_{x2}+R_{\mathrm{contx}}}{R_{x1}+R_{x2}+2R_{\mathrm{contx}}}---\left(1\right)$

$V_{\mathrm{seny}}=V_{\mathrm{ref}}\frac{R_{y2}+R_{\mathrm{conty}}}{R_{y1}+R_{y2}+2R_{\mathrm{conty}}}$

Therefore, it can, according to voltage divider principle, determine touch point by the position coordinates magnitude of voltage of detection X-direction and Y-direction Position.

But in portable product, man-machine interface is in addition to touch screen, it is necessary to retain a number of button, in case The special applications such as switching on and shutting down.The mode realizing button at present has following several:

1) capacitance type touch key

Capacitance type touch key is relatively costly, and needs corresponding drive integrated circult IC, extensively should therefore be unsuitable for With.

2) realize with logic change or the analog voltage of resistance with switch Series detectors voltage

Specifically, integrated circuit pin and the switch being connected with pin and resistance can be increased, by detection pin Voltage determines whether switch is pressed, if a corresponding switch of pin, then detects the logic change of voltage；If one The corresponding multiple switches of pin, when different switches is pressed, corresponding different analog voltage, then detect analog voltage.

Resistance is relatively low due to cost with the implementation method of the logic change of switch Series detectors voltage or analog voltage, Mid and low-end products are used widely.But this mode needs independent integrated circuit pin ICpin, the hardware therefore taken Resource is the most.If be pressed it addition, detect some button by detection analog voltage, need a detection simulation The analog-digital converter ADC of voltage.

3) resistive touch button

Fig. 2 is a kind of prior art resistive touch based on touch screen Cleaning Principle button schematic diagram.By two-layer ito film On extraction electrode extend and form button electrode, the insulating barrier between two-layer ito film digs on the position of corresponding button electrode Sky, the two-layer ito film conducting when respective keys is pressed, judge it is which button is pressed according to the logical value of voltage.

Use which to realize button to have the disadvantage that: need touch screen is carried out structural change；Support by bond number Measure limited；If with touch screen multiplexing, it is impossible to distinguish and press four angles of touch screen or press button.

4) resistive touch screen and button multiplexing

Fig. 3 is the theory diagram of a kind of traditional resistive touch screen and button multiplexing.XN and YN terminal at touch screen On connected two buttons resistance Rk1, Rk2, and be attached in mode shown in Fig. 3 by two switches.This technology utilizes to be touched The dynamic range distribution differentiation touching screen detection IC is pressed touch screen or presses button.But this technology has following two Shortcoming: touch screen accuracy of detection reduces, declines the rejection ability of the interference of LCD；The nominal resistance of two planes of touch screen is such as Fruit changes greatly, it may appear that the problem that touch screen correction was lost efficacy.

Summary of the invention

The present invention provides a kind of resistive touch screen and button multiplexing circuit and detection method, for saving hardware resource On the basis of, realize the detection of touch screen and button accurately.

The present invention relates to a kind of resistive touch screen and button multiplexing circuit, including the two-layer resistance utilizing medium to isolate Film, wherein one layer of resistive film at two edges of X-direction respectively one end with a lead resistance be connected；Another layer of resistive film exists One end with a lead resistance respectively, two edges of Y-direction is connected, and the other end of each lead resistance connects a lead-in wire Terminal, this circuit also includes:

It is connected at least one key circuit between a lead terminal of X-direction and a lead terminal of Y-direction, Described key circuit includes resistance and the switch being connected in series；

Testing circuit, for applying voltage, by the two of Y-direction lead terminals on two lead terminals of X-direction Determine coordinate voltage value V of X-direction_senx, two lead terminals in the Y direction apply voltage, by the two of X-direction lead-in wires Terminal determines coordinate voltage value V of Y-direction_seny, according to V_senxAnd V_senyDetermine position on resistive film, the touch point or determine and be No press switch.

The present invention also provides for a kind of method that resistive touch screen and button multiplexing circuit carry out detecting, and this circuit includes: Utilizing two-layer resistive film, testing circuit that medium isolates, wherein one layer of resistive film draws with one respectively at two edges of X-direction One end of line resistance connects；One end with a lead resistance respectively, another layer of resistive film two edges in the Y direction is connected, often The other end of individual lead resistance connects a lead terminal, and this circuit also includes the lead terminal being connected to X-direction and Y side To a lead terminal between at least one key circuit, described key circuit includes resistance and the switch being connected in series, The method includes:

Testing circuit applies voltage on two lead terminals of X-direction, determines X by the two of Y-direction lead terminals Coordinate voltage value V in direction_senx；

Apply voltage on testing circuit two lead terminals in the Y direction, determine Y by the two of X-direction lead terminals Coordinate voltage value V in direction_seny；

Testing circuit is according to V_senxAnd V_senyDetermine position on resistive film, the touch point or determine whether to press switch.

Utilize resistive touch screen and button multiplexing circuit and detection method that the present invention provides, it is only necessary to existing resistance The printed circuit of formula touch screen is modified, it is not necessary to increases circuit pin, therefore saves hardware resource；Utilize traditional touching Touch screen testing circuit, use new testing mechanism can support touch screen and button detection simultaneously, there is higher accuracy of detection Stronger capacity of resisting disturbance.

Accompanying drawing explanation

Fig. 1 is resistive touch screen equivalent-circuit model and Cleaning Principle block diagram；

Fig. 2 is prior art resistive touch based on touch screen Cleaning Principle button schematic diagram；

Fig. 3 prior art touch screen and the schematic diagram of button multiplexing；

Fig. 4 is the schematic diagram of embodiment of the present invention resistive touch screen and button multiplexing；

Fig. 5 a is that the embodiment of the present invention applies voltage, detection Y-direction lead terminal voltage signal at the lead terminal of X-direction Figure；

Fig. 5 b is that embodiment of the present invention lead terminal in the Y direction applies voltage, detection X-direction lead terminal voltage signal Figure；

Fig. 5 c is that the embodiment of the present invention applies voltage at YP, XN, detects X-direction lead resistance V diagram.

Detailed description of the invention

The resistive touch screen with embodiment, the present invention provided below in conjunction with the accompanying drawings and button multiplexing circuit and detection side Method illustrates in greater detail.

The embodiment of the present invention provides a kind of resistive touch screen and button multiplexing circuit, including the two-layer utilizing medium to isolate Resistive film, resistive film can use the indium tin oxide ITO semiconductor layer of homogeneous conductive, and wherein one layer of resistive film is in X-direction One end with a lead resistance respectively, two edges is connected, and therefore this resistive film plane is referred to as X-plane；Another layer of resistive film exists One end with a lead resistance respectively, two edges of Y-direction is connected, and therefore this resistive film plane is referred to as Y plane, Mei Geyin The other end of line resistance connects a lead terminal, and this circuit also includes:

It is connected at least one key circuit between a lead terminal of X-direction and a lead terminal of Y-direction, Described key circuit includes resistance and the switch being connected in series；

Testing circuit, for applying voltage, by the two of Y-direction lead terminals on two lead terminals of X-direction Determine coordinate voltage value V of X-direction_senx, two lead terminals in the Y direction apply voltage, by the two of X-direction lead-in wires Terminal determines coordinate voltage value V of Y-direction_seny, according to V_senxAnd V_senyDetermine position on resistive film, the touch point or determine and be No press switch.

Above-mentioned X-direction and Y-direction are two mutually perpendicular directions, horizontally and vertically two sides of concrete corresponding touch screen To.

If Fig. 4 is the equivalent circuit that embodiment of the present invention resistive touch screen is corresponding with button multiplexing circuit, figure does not shows Going out the testing circuit being connected with four lead terminals, wherein, Rx1+Rx2 is the equivalent resistance of the resistive film of X-plane, Rx1, Rx2 For the separate two sections of resistance of X-plane touched point, Ry1+Ry2 is the equivalent resistance of the resistive film of Y plane, and Ry1, Ry2 are Y plane The separate two sections of resistance of touched point, Rtouch is contact resistance during two plane contact, and Rcontx is that resistive film is in X-direction The lead resistance that connects of two edges, Rconty is the lead resistance that resistive film two edges in the Y direction connect.XP、XN Two leading-out terminals being connected with lead resistance Rcontx for X-plane, YP, YN are that Y plane is connected with lead resistance Rconty Two leading-out terminals.

In the embodiment of the present invention, it is connected between a lead terminal XP and a lead terminal YP of Y-direction of X-direction Have at least one key circuit, then testing circuit applies voltage on XP, XN, may determine that X by the voltage of detection YP, YN end Coordinate voltage value V in direction_senx, YP, YN apply voltage, be may determine that the seat of Y-direction by the voltage of detection XP, XN end Mark magnitude of voltage V_seny, according to V_senxAnd V_senyDetermine position on resistive film, the touch point or determine whether to press switch.

The embodiment of the present invention is given below according to V_senxAnd V_seny, it may be determined that position or true on resistive film, the touch point The fixed Cleaning Principle whether pressing switch.

If user presses after touch screen i.e. presses on resistive film, X-direction, Y-direction lead terminal on timesharing execute The voltage V added_ref, according to X-direction and the same formula of the coordinate voltage value (1) of Y-direction of the detection of electric resistance partial pressure principle:

$V_{\mathrm{senx}}=V_{\mathrm{ref}}\frac{R_{x2}+R_{\mathrm{contx}}}{R_{x1}+R_{x2}+2R_{\mathrm{contx}}}---\left(1\right)$

$V_{\mathrm{seny}}=V_{\mathrm{ref}}\frac{R_{y2}+R_{\mathrm{conty}}}{R_{y1}+R_{y2}+2R_{\mathrm{conty}}}$

R_contxFor the resistance of lead resistance Rcontx of X-direction, R_contyFor the resistance of lead resistance Rconty of Y-direction, R_x1For the resistance of Rx1, R_x2For the resistance of Rx2, R_y1For the resistance of Ry1, R_y2Resistance for Ry2.

Understanding, when pressing four corners of touch screen, touch point is at the maximum coordinates magnitude of voltage V1 of the X-direction of resistive film With the maximum coordinates magnitude of voltage V2 of Y-direction it is:

$V1=V_{\mathrm{ref}}\frac{R_{x1}+R_{x2}+R_{\mathrm{contx}}}{R_{x1}+R_{x2}+2R_{\mathrm{contx}}}=V_{\mathrm{ref}}(1-\frac{R_{\mathrm{contx}}}{R_{x1}+R_{x2}+2R_{\mathrm{contx}}})---\left(2\right)$

$V2=V_{\mathrm{ref}}\frac{R_{y1}+R_{y2}+R_{\mathrm{conty}}}{R_{y1}+R_{y2}+2R_{\mathrm{conty}}}=V_{\mathrm{ref}}(1-\frac{R_{\mathrm{conty}}}{R_{y1}+R_{y2}+2R_{\mathrm{conty}}})$

Also according to electric resistance partial pressure principle, determine coordinate voltage value V of X-direction when either switch is pressed_senx,kWith Y side To coordinate voltage value V_seny,k, with reference to Fig. 5 a and Fig. 5 b, after the switch of the arbitrary key circuit pressed between XP and YP, X side To coordinate voltage value V_senx,kCoordinate voltage value V with Y-direction_seny,kFor:

Contrast (2) formula with (3) formula it can be seen that the coordinate voltage of X, Y both direction after pressing the switch that button is corresponding Value is equal to reference source voltage, and after pressing touch screen, the maximum of the coordinate voltage value of X, Y both direction is necessarily less than Reference source voltage.The difference of the two is respectively as follows:

$V_{\mathrm{senx},k}-V1=V_{\mathrm{ref}}\frac{R_{\mathrm{contx}}}{R_{x1}+R_{x2}+2R_{\mathrm{contx}}}---\left(4\right)$

$V_{\mathrm{seny},k}-V2=V_{\mathrm{ref}}\frac{R_{\mathrm{conty}}}{R_{y1}+R_{y2}+2R_{\mathrm{conty}}}$

It is to say, button presses the coordinate voltage value of collection necessarily more than pressing the maximum seat that touch screen gathers in theory Mark magnitude of voltage, may determine that according to this difference and presses button or press touch screen.

Preferably, the embodiment of the present invention predefines the touch point maximum coordinates magnitude of voltage V1 in the X-direction of resistive film With the maximum coordinates magnitude of voltage V2 of Y-direction, and coordinate voltage value V of X-direction when the switch of arbitrary key circuit is pressed_senx,k Coordinate voltage value V with Y-direction_seny,k；

Then testing circuit is specifically for determining V_senxMore than V1 and and V_senx,kDifference in set point, V_senyMore than V2 And and V_seny,kDifference in set point time, determine that switch is pressed；Otherwise determine that resistive film is touched, and according to V_senx And V_senyDetermine position on resistive film, the touch point, specifically can determine position on resistive film, the touch point according to existing mode Putting, I will not elaborate.

According in the preferred embodiments of the present invention, key circuit is multiple, and in multiple key circuits, the resistance of resistance is the most not Identical, the equivalent resistance that current two-layer resistive film is corresponding respectively is the same order of magnitude, it is preferable that the resistance of resistance in key circuit The value equivalent resistance the most corresponding with two-layer resistive film is the same order of magnitude, so can more accurately distinguish between button and still touch Touch screen to be pressed.

According to above-mentioned principle, it may be determined that be that touch screen is pressed or the switch that button is corresponding is pressed, be judged as After button is pressed, in the case of having multiple key circuit parallel connection, need to confirm that the switch which button is corresponding is pressed, this The bright embodiment following either type of employing:

1), after testing circuit is further used for determining and presses switch, lead terminal and the Y of key circuit it are not connected with in X-direction Direction connects applying voltage on the lead terminal of key circuit, by the magnitude of voltage V of the two of X-direction lead terminals_senz1,kReally The fixed switch pressed；

As shown in Figure 5 c, voltage drive is added between YP and XN, if switch k1 is pressed, permissible according to electric resistance partial pressure principle Obtain the voltage V at XP and XN two ends_senz1,k1:

$V_{\mathrm{senz}1,k1}=V_{\mathrm{ref}}\frac{R_{x1}+R_{x2}+2R_{\mathrm{contx}}}{R_{x1}+R_{x2}+2R_{\mathrm{contx}}+R_{k1}}---\left(5\right)$

Visible, when different switches is pressed, the resistance of the resistance owing to being connected is different, therefore, detects V_senz1,kDifference, may thereby determine which switch is pressed.

In view of the fluctuation of touch screen X-plane resistance, different key sampled voltage interval will be caused uncertain, can detect Touch screen X-plane resistance, recycles the analog voltage that the resistance correcting key of this resistance gathers.

Preferably, it may be predetermined that the lead terminal being not connected with key circuit in X-direction is connected key circuit with Y-direction Lead terminal on apply voltage, when the switch in each key circuit is depressed, this switch corresponding nominal detection magnitude of voltage； After the most described testing circuit determines and presses switch, according to V_senz1,kDetect with each nominal corresponding to switch magnitude of voltage determine by Under switch.

2), after testing circuit testing circuit is further used for determining and presses switch, the lead-in wire of key circuit is connected in X-direction Terminal and Y-direction are not connected with on the lead terminal of key circuit applying voltage, by the magnitude of voltage of the two of Y-direction lead terminals V_senz2,kDetermine pressed switch.

Predefine and connect lead terminal and the Y-direction of key circuit in X-direction and be not connected with the lead terminal of key circuit Upper applying voltage, when the switch in each key circuit is depressed, the nominal detection magnitude of voltage that this switch is corresponding；The most described detection After circuit determines and presses switch, according to V_senz2,kThe nominal detection magnitude of voltage corresponding with each switch determines pressed switch. Ibid, I will not elaborate for concrete principle.

If there is resistive touch screen in the product, it drives and inherently contains an ADC inside IC, the most just expects Resistive touch screen could detect with button simultaneously, and the two is independent of each other.

Outside the resistive touch screen that the embodiment of the present invention provides is with button multiplexing circuit, with traditional resistive touch screen The difference enclosing circuit connecting is to have bridged N number of resistance and N number of switch between the lead terminal of two planes of touch screen, the most right Answer different buttons.Owing to button is to be connected across between two planes of XY, for touch action detection logic circuit, press Button with press touch screen equivalence, therefore have only to the printed circuit of existing resistive touch screen is modified, it is not necessary to Increase circuit pin, save hardware resource；Utilize traditional touch screen testing circuit, use the new testing mechanism can simultaneously Support touch screen and button detection, there is higher accuracy of detection and stronger capacity of resisting disturbance.

Above-described embodiment gives between XP, XN the situation of key circuit in parallel, in like manner, button is connected across XN, YN and Other combined situation are without departure from the protection domain of this technology.

An ADC, testing circuit is inherently contained inside the drive circuit IC of resistive touch screen of the present invention The voltage gathered is analog voltage, is input in this adc circuit carry out analog digital conversion, it is not necessary to be additionally provided adc circuit.

The embodiment of the present invention additionally provides a kind of method that resistive touch screen and button multiplexing circuit carry out detecting, this electricity Road includes: utilizing two-layer resistive film, testing circuit that medium isolates, wherein one layer of resistive film is at two edges of X-direction respectively It is connected with one end of a lead resistance；Another layer of resistive film two edges in the Y direction respectively with the one of a lead resistance End connects, and the other end of each lead resistance connects a lead terminal, and this circuit also includes the lead-in wire being connected to X-direction At least one key circuit between terminal and a lead terminal of Y-direction, described key circuit includes the electricity being connected in series Resistance and switch, the method includes:

Testing circuit applies voltage on two lead terminals of X-direction, determines X by the two of Y-direction lead terminals Coordinate voltage value V in direction_senx；

Apply voltage on testing circuit two lead terminals in the Y direction, determine Y by the two of X-direction lead terminals Coordinate voltage value V in direction_seny；

Testing circuit is according to V_senxAnd V_senyDetermine position on resistive film, the touch point or determine whether to press switch.

Preferably, described key circuit is multiple, and in multiple key circuits, the resistance of resistance is different, and the method enters one Step includes:

After described testing circuit determines and presses switch, the lead terminal being not connected with key circuit in X-direction is connected with Y-direction Voltage is applied, by the magnitude of voltage V of the two of X-direction lead terminals on the lead terminal of key circuit_senz1,kDetermine and pressed Switch；Or

After described testing circuit testing circuit determines and presses switch, connect lead terminal and the Y side of key circuit in X-direction Voltage is applied, by the magnitude of voltage V of the two of Y-direction lead terminals on the lead terminal be not connected with key circuit_senz2,kReally The fixed switch pressed.

Preferably, predetermined touch point is sat at the maximum coordinates magnitude of voltage V1 of the X-direction of resistive film and the maximum of Y-direction Mark magnitude of voltage V2, and coordinate voltage value V of X-direction when either switch is pressed_senx,kCoordinate voltage value V with Y-direction_seny,k；

Then testing circuit is according to V_senxAnd V_senyDetermine position on resistive film, the touch point or determine whether to press switch, Specifically include:

Determine V_senxMore than V1 and and V_senx,kDifference in set point, V_senyMore than V2 and and V_seny,kDifference exist Time in set point, determine that switch is pressed；

Otherwise determine that resistive film is touched, and according to V_senxAnd V_senyDetermine position on resistive film, the touch point.

Preferably, predefine and be not connected with the lead terminal of key circuit in X-direction and be connected drawing of key circuit with Y-direction Voltage is applied in line terminals, when the switch in each key circuit is depressed, the nominal detection magnitude of voltage that this switch is corresponding；

After the most described testing circuit determines and presses switch, according to V_senz1,kThe nominal detection magnitude of voltage corresponding with each switch Determine pressed switch；Or

Predefine and connect lead terminal and the Y-direction of key circuit in X-direction and be not connected with the lead terminal of key circuit Upper applying voltage, when the switch in each key circuit is depressed, the nominal detection magnitude of voltage that this switch is corresponding；

After the most described testing circuit determines and presses switch, according to V_senz2,kThe nominal detection magnitude of voltage corresponding with each switch Determine pressed switch.

Preferably, predefine and be not connected with the lead terminal of key circuit in X-direction and be connected drawing of key circuit with Y-direction Voltage is applied in line terminals, when the switch in each key circuit is depressed, the nominal detection magnitude of voltage that this switch is corresponding, specifically Including:

Determine that being not connected with the lead terminal of key circuit in X-direction is connected on the lead terminal of key circuit with Y-direction and executes Making alive, nominal detection magnitude of voltage corresponding when being pressed for the switch k1 in arbitrary key circuit:

$V_{\mathrm{senz}1,k1}=V_{\mathrm{ref}}\frac{R_{x1}+R_{x2}+2R_{\mathrm{contx}}}{R_{x1}+R_{x2}+2R_{\mathrm{contx}}+R_{k1}}$

Such that it is able to release:

$R_{x1}+R_{x2}+2R_{\mathrm{contx}}=\frac{V_{\mathrm{senz}1,k1}}{V_{\mathrm{ref}}-V_{\mathrm{senz}1,k1}}{R}_{k1}$

Then determine that nominal detection magnitude of voltage corresponding when being pressed for the switch kn in other key circuits is:

$V_{\mathrm{senz}1,\mathrm{kn}}=V_{\mathrm{ref}}\frac{\frac{V_{\mathrm{senz}1,k1}}{V_{\mathrm{ref}}-V_{\mathrm{senz}1,k1}}{R}_{k1}}{\frac{V_{\mathrm{senz}1,k1}}{V_{\mathrm{ref}}-V_{\mathrm{senz}1,k1}}{R}_{k1}+R_{\mathrm{kn}}}$

Wherein, R_contxFor the resistance of the lead resistance of X-direction, R_x1+R_x2For the resistive film at X-direction connecting lead wire resistance Equivalent resistance, V_refIt is connected the lead terminal of key circuit with Y-direction for being not connected with the lead terminal of key circuit in X-direction The voltage of upper applying；

Predefine and connect lead terminal and the Y-direction of key circuit in X-direction and be not connected with the lead terminal of key circuit Upper applying voltage, when the switch in each key circuit is depressed, the nominal detection magnitude of voltage that this switch is corresponding, specifically include:

Determine that the lead terminal at X-direction connection key circuit is not connected with on the lead terminal of key circuit executing with Y-direction Making alive, nominal detection magnitude of voltage corresponding when being pressed for the switch k1 in arbitrary key circuit:

$V_{\mathrm{senz}2,k1}=V_{\mathrm{ref}}\frac{R_{y1}+R_{y2}+2R_{\mathrm{conty}}}{R_{y1}+R_{y2}+2R_{\mathrm{conty}}+R_{k1}}$

Such that it is able to release:

$R_{y1}+R_{y2}+2R_{\mathrm{conty}}=\frac{V_{\mathrm{senz}2,k1}}{V_{\mathrm{ref}}-V_{\mathrm{senz}2,k1}}{R}_{k1}$

Then determine that nominal detection magnitude of voltage corresponding when being pressed for the switch kn in other key circuits is:

$V_{\mathrm{senz}2,\mathrm{kn}}=V_{\mathrm{ref}}\frac{\frac{V_{\mathrm{senz}2,k1}}{V_{\mathrm{ref}}-V_{\mathrm{senz}2,k1}}{R}_{k1}}{\frac{V_{\mathrm{senz}2,k1}}{V_{\mathrm{ref}}-V_{\mathrm{senz}2,k1}}{R}_{k1}+R_{\mathrm{kn}}}$

Wherein, R_contyFor the resistance of the lead resistance of Y-direction, R_y1+R_y2Resistive film for connecting lead wire resistance in the Y direction Equivalent resistance, V_refLead terminal and Y-direction for connecting key circuit in X-direction is not connected with the lead terminal of key circuit The voltage of upper applying；

R_k1The resistance of the resistance for being connected with switch k1, R_knThe resistance of the resistance for being connected with switch kn.

User press touch screen and by key assignments for several times after, correctly detect user's touch location on the touchscreen and Detecting that total degree that user pushes button is accuracy of detection with the ratio of set point number, preferable accuracy of detection is 100%.Excellent Selection of land, can set a ratio, if detection is established a capital higher than this setting ratio, then it is assumed that reach to set requirement, in detection essence When degree not up to sets ratio, not up to requirement is described, then can increase the lead resistance of X-direction and the lead resistance of Y-direction Resistance value.

Obviously, those skilled in the art can carry out various change and the modification essence without deviating from the present invention to the present invention God and scope.So, if these amendments of the present invention and modification belong to the scope of the claims in the present invention and equivalent technologies thereof Within, then the present invention is also intended to comprise these change and modification.

Claims (11)

1. resistive touch screen and a button multiplexing circuit, including the two-layer resistive film utilizing medium to isolate, wherein, one layer of electricity Resistance film at two edges of X-direction respectively one end with a lead resistance be connected；Another layer of resistive film two limits in the Y direction Edge one end with a lead resistance respectively is connected, and the other end of each lead resistance connects a lead terminal, and its feature exists In, also include:

It is connected at least one key circuit between a lead terminal of X-direction and a lead terminal of Y-direction, described Key circuit includes resistance and the switch being connected in series；

Testing circuit, for applying voltage on two lead terminals of X-direction, determines X by the two of Y-direction lead terminals Coordinate voltage value V in direction_senx, two lead terminals in the Y direction apply voltage, by the two of X-direction lead terminals Determine coordinate voltage value V of Y-direction_seny, according to V_senxAnd V_senyDetermine position on resistive film, the touch point or determine whether by Lower switch.

2. circuit as claimed in claim 1, it is characterised in that described key circuit is multiple, resistance in multiple key circuits Resistance different, wherein,

Described testing circuit is additionally operable to determine after pressing switch, is not connected with the lead terminal of key circuit with Y-direction even in X-direction Connect applying voltage on the lead terminal of key circuit, by the magnitude of voltage V between the two of X-direction lead terminals_senz1,kDetermine The switch pressed；Or

Described testing circuit is additionally operable to determine after pressing switch, and the lead terminal connecting key circuit in X-direction does not connects with Y-direction Connect applying voltage on the lead terminal of key circuit, by the magnitude of voltage V between the two of Y-direction lead terminals_senz2,kDetermine The switch pressed.

3. circuit as claimed in claim 1 or 2, it is characterised in that predetermined touch point is in the maximum of the X-direction of resistive film The maximum coordinates magnitude of voltage V2 of coordinate voltage value V1 and Y-direction, and the coordinate voltage value of X-direction when either switch is pressed V_senx,kCoordinate voltage value V with Y-direction_seny,k；

Then testing circuit is specifically for determining V_senxMore than V1 and and V_senx,kDifference in set point, V_senyMore than V2 and with V_seny,kDifference in set point time, determine that switch is pressed；Otherwise determine that resistive film is touched, and according to V_senxAnd V_seny Determine position on resistive film, the touch point.

4. circuit as claimed in claim 2, it is characterised in that

Predefine and be not connected with the lead terminal of key circuit in X-direction and be connected on the lead terminal of key circuit with Y-direction and execute Making alive, when the switch in each key circuit is depressed, the nominal detection magnitude of voltage that this switch is corresponding；The most described testing circuit After determining and pressing switch, according to V_senz1,kThe nominal detection magnitude of voltage corresponding with each switch determines that is pressed opens Close；Or

Predefine the lead terminal at X-direction connection key circuit to be not connected with on the lead terminal of key circuit executing with Y-direction Making alive, when the switch in each key circuit is depressed, the nominal detection magnitude of voltage that this switch is corresponding；The most described testing circuit After determining and pressing switch, according to V_senz2,kThe nominal detection magnitude of voltage corresponding with each switch determines that is pressed opens Close.

5. circuit as claimed in claim 1 or 2, it is characterised in that the resistance of resistance and two-layer resistance in described key circuit The equivalent resistance that film is corresponding respectively is the same order of magnitude.

6. resistive touch screen and button multiplexing circuit carry out the method detected, and this circuit includes: utilize medium to isolate Two-layer resistive film, testing circuit, wherein one layer of resistive film is at two edges of X-direction respectively with one end of a lead resistance even Connect；One end with a lead resistance respectively, another layer of resistive film two edges in the Y direction is connected, each lead resistance another One end connects a lead terminal, and this circuit also includes a lead end of a lead terminal and the Y-direction being connected to X-direction At least one key circuit between son, described key circuit includes resistance and the switch being connected in series, it is characterised in that the party Method includes:

Testing circuit applies voltage on two lead terminals of X-direction, determines X-direction by the two of Y-direction lead terminals Coordinate voltage value V_senx；

Apply voltage on testing circuit two lead terminals in the Y direction, determine Y-direction by the two of X-direction lead terminals Coordinate voltage value V_seny；

Testing circuit is according to V_senxAnd V_senyDetermine position on resistive film, the touch point or determine whether to press switch.

7. method as claimed in claim 6, described key circuit is multiple, the resistance of resistance the most not phase in multiple key circuits With, it is characterised in that the method farther includes:

After described testing circuit determines and presses switch, the lead terminal being not connected with key circuit in X-direction is connected button with Y-direction Voltage is applied, by the magnitude of voltage V between the two of X-direction lead terminals on the lead terminal of circuit_senz1,kDetermine and pressed Switch；Or

After described testing circuit testing circuit determines and presses switch, connect the lead terminal of key circuit with Y-direction not in X-direction Connect and on the lead terminal of key circuit, apply voltage, by the magnitude of voltage V between the two of Y-direction lead terminals_senz2,kReally The fixed switch pressed.

Method the most as claimed in claims 6 or 7, it is characterised in that predetermined touch point is in the maximum of the X-direction of resistive film The maximum coordinates magnitude of voltage V2 of coordinate voltage value V1 and Y-direction, and the coordinate voltage value of X-direction when either switch is pressed V_senx,kCoordinate voltage value V with Y-direction_seny,k；

Then testing circuit is according to V_senxAnd V_senyDetermine position on resistive film, the touch point or determine whether to press switch, specifically Including:

Determine V_senxMore than V1 and and V_senx,kDifference in set point, V_senyMore than V2 and and V_seny,kDifference set In the range of time, determine that switch is pressed；

Otherwise determine that resistive film is touched, and according to V_senxAnd V_senyDetermine position on resistive film, the touch point.

9. method as claimed in claim 7, it is characterised in that

Predefine and be not connected with the lead terminal of key circuit in X-direction and be connected on the lead terminal of key circuit with Y-direction and execute Making alive, when the switch in each key circuit is depressed, the nominal detection magnitude of voltage that this switch is corresponding；

After the most described testing circuit determines and presses switch, according to V_senz1,kThe nominal detection magnitude of voltage corresponding with each switch determines The switch pressed；Or

Predefine the lead terminal at X-direction connection key circuit to be not connected with on the lead terminal of key circuit executing with Y-direction Making alive, when the switch in each key circuit is depressed, the nominal detection magnitude of voltage that this switch is corresponding；

After the most described testing circuit determines and presses switch, according to V_senz2,kThe nominal detection magnitude of voltage corresponding with each switch determines The switch pressed.

10. method as claimed in claim 9, it is characterised in that predefine the lead end being not connected with key circuit in X-direction Son is connected on the lead terminal of key circuit applying voltage, when the switch in each key circuit is depressed, this switch with Y-direction Corresponding nominal detection magnitude of voltage, specifically includes:

Determine that be not connected with the lead terminal of key circuit in X-direction is connected on the lead terminal of key circuit applying electricity with Y-direction Pressure, nominal detection magnitude of voltage corresponding when being pressed for the switch k1 in arbitrary key circuit:

$V_{senz1,k1}=V_{ref}\frac{R_{x1}+R_{x2}+2R_{contx}}{R_{x1}+R_{x2}+2R_{contx}+R_{k1}}$

Determine that nominal detection magnitude of voltage corresponding when being pressed for the switch kn in other key circuits is:

$V_{senz1,kn}=V_{ref}\frac{\frac{V_{senz1,k1}}{V_{ref}-V_{senz1,k1}}{R}_{k1}}{\frac{V_{senz1,k1}}{V_{ref}-V_{senz1,k1}}{R}_{k1}+R_{kn}}$

Wherein, R_contxFor the resistance of the lead resistance of X-direction, R_x1+R_x2For the resistive film at X-direction connecting lead wire resistance etc. Effect resistance, V_refIt is connected on the lead terminal of key circuit with Y-direction executes for being not connected with the lead terminal of key circuit in X-direction The voltage added；

Predefine the lead terminal at X-direction connection key circuit to be not connected with on the lead terminal of key circuit executing with Y-direction Making alive, when the switch in each key circuit is depressed, the nominal detection magnitude of voltage that this switch is corresponding, specifically include:

Determine that the lead terminal at X-direction connection key circuit is not connected with on the lead terminal of key circuit applying electricity with Y-direction Pressure, nominal detection magnitude of voltage corresponding when being pressed for the switch k1 in arbitrary key circuit:

$V_{senz2,k1}=V_{ref}\frac{R_{y1}+R_{y2}+2R_{conty}}{R_{y1}+R_{y2}+2R_{conty}+R_{k1}}$

Determine that nominal detection magnitude of voltage corresponding when being pressed for the switch kn in other key circuits is:

$V_{senz2,kn}=V_{ref}\frac{\frac{V_{senz2,k1}}{V_{ref}-V_{senz2,k1}}{R}_{k1}}{\frac{V_{senz2,k1}}{V_{ref}-V_{senz2,k1}}{R}_{k1}+R_{kn}}$

Wherein, R_contyFor the resistance of the lead resistance of Y-direction, R_y1+R_y2For connecting lead wire resistance in the Y direction resistive film etc. Effect resistance, V_refIt is not connected with on the lead terminal of key circuit executing with Y-direction for connecting the lead terminal of key circuit in X-direction The voltage added；

R_k1The resistance of the resistance for being connected with switch k1, R_knThe resistance of the resistance for being connected with switch kn.

11. methods as claimed in claim 6, it is characterised in that when accuracy of detection not up to sets ratio, increase drawing of X-direction The resistance value of the lead resistance of line resistance and Y-direction.