TWI385564B - Device and method for determining positions of multiple touches on a projected capacitive touch panel - Google Patents

Description

Device and method for determining multi-contact position of projected capacitive touch panel

The invention relates to a device for determining the position of a multi-contact and a method thereof, and more particularly to a device for determining a multi-contact position of a projected capacitive touch panel and a method thereof.

There are currently a variety of touch technologies on the market, including resistive, capacitive, surface acoustic wave (SAW) and infrared (IR). Whether it is resistive, capacitive, surface acoustic wave or infrared touch technology, multi-touch function can be realized. Looking further, capacitive touch can be divided into two types: surface capacitive (Surface Capacitive) and projected capacitive (Projected Capacitive). The surface capacitive technology is quite similar to the resistive method. The design is simple and the cost is very high. Cheap, but not the ideal technology for multi-touch. To make the product reach the multi-touch function, it is a better solution to choose the projection capacitive touch technology.

The first A picture is an exploded perspective view of a conventional projected capacitive touch panel. As shown in FIG. A, the capacitive touch panel 10 is formed from a transparent substrate 11, an X transparent sensing layer 12, a transparent dielectric layer 13, and a transparent Y sensing film layer 14 from bottom to top. Forming, wherein the X and Y transparent sensing layers 12, 14 each have a sensing pattern 15 for use with other components to determine the presence of one or more contacts on the panel 10, wherein the sensing pattern 15 is A plurality of external wires 19 are connected, as will be described below.

The first B diagram and the first C diagram are schematic diagrams of the sensing patterns 15 on the X and Y sensing layers 12, 14 of the projected capacitive touch panel shown in the first figure, and the first D diagram is the first B. FIG. 1 is a top plan view showing the sensing pattern of the overlapped X and Y sensing layers of the capacitive touch panel 10 shown in FIG.

As shown in the first B, the first C, and the first D, the sensing pattern 15 includes a plurality of X sensing strips 151 and a plurality of Y sensing strips 152, and each of the X sensing strips 151 Each of the Y sensing strips 152 is composed of a plurality of Y conductive wires 17 and a plurality of sensing plates 18, and each of the Y sensing strips 152 is composed of a plurality of X conductive wires 16 and a plurality of sensing plates 18, The sensing patterns 15 are periodically connected between the adjacent X and Y conductive lines 16, 17. The sensing pattern 15 is disposed under a glass plate (not shown) of the touch panel 10, and together with the plurality of external wires 19 and a sensing signal source 21, constitutes a sensing device 20 of the panel 10. The external wires 19 are respectively disposed between the sensing signal source 21 and the corresponding X and Y conductive line diameters 16, 17.

In actual operation, the sensing signal source 21 sequentially supplies an alternating current sensing voltage Vs to each of the X conductive line diameters 16, and then sequentially supplies the alternating current sensing voltage Vs to each of the Y conductive line diameters 17, thereby The method senses a user's touch position P on the glass panel, as will be described below, wherein the glass plate is where the user's finger actually touches.

There is a capacitive effect between the X and Y sensing strips 151, 152 and the glass panel, and there is another capacitive effect between a virtual ground (not shown). When the user's finger touches a point P on the glass panel, the contact point brings another capacitive effect on the X and Y conductive line diameters 16, 17 , so an equivalent capacitance value under the contact point P is changed. The alternating sense voltage Vs produces a corresponding current I on each of the X and Y sense strips 151, 152 when sensing the amount of change in the equivalent capacitance value. At this time, by using a current detecting unit (not shown) to sense the change of the current I, the position of the contact P on the glass panel is determined, because the change of the current I corresponds to the equivalent The change in capacitance value.

When there is a multi-contact input, the projection capacitive touch panel cannot completely determine the position of the multi-contact, which will be described later with the second figure. The second figure is a schematic diagram showing the top view of a conventional projection capacitive touch panel having multiple contacts, and its structure is the same as that shown in the first A, B and C diagrams. As shown in the second figure, if the user actually produces a set of contacts P1 (x1, y1) and P2 (x2, y2) on the conventional projected capacitive touch panel 10, but for the conventional projection capacitive touch panel 10, it is possible to correctly interpret the set of contacts P1 (x1, y1) and P2 (x2, y2) as shown in the second figure or will be misinterpreted as another set of contacts P3 (x1, y2) With P4 (x2, y1). Therefore, for the conventional projection capacitive touch panel 10, the two contacts input by the user on the projected capacitive touch panel 10 are P1 (x1, y1) and P2 (x2, y2) or P3 (x1, Y2) and P4 (x2, y1) cannot be clarified.

In view of the above problems in the prior art, the present invention proposes a device for determining a multi-contact position of a projected capacitive touch panel and a method thereof, thereby overcoming the disadvantages of the prior art.

The object of the present invention is to clearly determine the position of a multi-contact and find the position of the multi-contact by means of a look-up table.

In order to achieve the above object, the present invention provides a device for determining a multi-contact position on a projection capacitive touch panel, the device for determining a multi-contact position comprising an external lead unit, a sensing voltage supply unit, and a sense of current The measuring unit, a preliminary coordinate determining unit and a position coordinate determining unit.

The external lead unit is respectively provided in a one-to-one relationship to connect a plurality of X and Y external wires to the plurality of X sensing strips and Y sensing strips; a sensing voltage supply unit is used to Providing an alternating sensing voltage to the plurality of X sensing strips, and then sequentially providing the alternating sensing voltage to the plurality of Y sensing strips; a current sensing unit is configured to sequentially sense respectively One X current and one Y current on each of the X and Y sensing strips respectively to obtain the at least one set of X current values and the at least one set of Y current values; a preliminary coordinate determining unit for determining via the a current coordinate sensing unit senses a preliminary coordinate of at least one contact; and a position coordinate determining unit, wherein the position coordinate determining unit stores a lookup table, wherein the position coordinate determining unit obtains the touches by the preliminary coordinate determining unit The x and y coordinates are paired to determine the actual position coordinates of the contacts.

The present invention also provides a method for determining a position of a multi-contact on a projection capacitive touch panel, the method comprising providing a plurality of X external wires and a plurality of Y external wires, respectively for electrically connecting the projections in a one-to-one relationship a plurality of X and Y sensing strips of the capacitive touch panel; sequentially providing an alternating current sensing voltage to the strips of the X sensing strips, and sequentially providing the alternating sensing voltages to the strips of the sensing strips And sensing, respectively, one of the X and Y currents of each of the X and Y sensing strips to obtain the at least one set of X current values and the at least one set of Y current values respectively Determining the initial position coordinates of the contacts on the X sensing strip and the Y sensing strip; and pairing the determined preliminary position coordinates of the contacts according to a lookup table to determine the The actual position of the contact.

The device and method of the present invention can clearly determine the position of the multi-contact, and the position of the multi-contact is determined by the look-up table. Therefore, compared with the prior art, the present invention does not add any hardware cost, and The method of the invention is a very convenient way.

In order to make the technology, means and functions of the present invention suitable for achieving the specific purpose, the following detailed description of the present invention and the accompanying drawings, which are believed to be Specific understanding. The drawings are to be considered in all respects as illustrative and not restrictive.

The present invention is a device for determining a multi-contact position of a projection capacitive touch panel and a method thereof, which will be described in detail by the preferred embodiment in conjunction with the accompanying drawings.

Please refer to the third figure, which is an exploded perspective view of the projected capacitive touch panel of the present invention. As shown in the third figure, the projected capacitive touch panel 30 includes a transparent substrate 31, an X transparent sensing layer 32, a transparent dielectric layer 33, and a transparent sensing layer. The layer 34 is the same as the conventional one, wherein the X transparent sensing layer 32 and the Y sensing film layer 34 each have a sensing pattern 37, and the sensing pattern 37 has a connection of the external wires 59. There are instructions.

Please refer to the fourth figure, which is a functional block diagram of a device for determining a multi-contact position of a projection capacitive touch panel of the present invention.

As shown in the fourth figure, the device 40 for determining the multi-contact position of the projection capacitive touch panel of the present invention comprises an external lead unit 41, a sensing voltage supply unit 42, a current sensing unit 43, and a preliminary coordinate determining unit. 44 and a position coordinate determining unit 45.

5A and 5B are top views of the device for determining a multi-contact position of the projection capacitive touch panel of the present invention when multiple contacts are placed thereon.

Referring to FIG. 3 to FIG. 5B simultaneously, the determining device 40 includes a plurality of X sensing strips arranged along the X direction on the X transparent sensing layer 32 of the projected capacitive touch panel 30 and the Y. A plurality of Y sensing strips arranged in the Y direction on the transparent sensing layer 34, the X sensing strips and the Y sensing strips are collectively referred to as a sensing pattern 37. When the multi-contact P1, P2 (illustrated by taking two points as an example) appears on the projected capacitive touch panel 30, the X transparent sensing film layer 32 and the Y transparent sensing layer 34 are in the plurality of touches. Points P1, P2, P3, and P4 are in contact (not shown), where P1 and P2 are the first group of multi-contacts, and P3 and P4 are the second group of multi-contacts.

First, the external lead wires unit 41 respectively provides a plurality of X and Y external wires in a one-to-one relationship with the X sensing strips and the Y sensing strips.

Then, the sensing voltage supply unit 42 sequentially supplies an alternating current sensing voltage Vx through the X sensing strips corresponding to the external wires 59, and then sequentially supplies the alternating sensing voltage Vy to the Y sensing strips, such as the fifth. Figure A and Figure B are shown. When the alternating sensing voltage Vx is supplied to the X sensing strip, a current I is formed at the positions of the contacts P1, P2, P3, P4, and then the alternating sensing voltage Vy is supplied to the Y sensing strip. At this time, a current I is formed at the positions of the contacts P1, P2, P3, and P4.

Then, the current sensing unit 43 senses the X and Y current pair groups at the positions of the contacts P1, P2, P3, and P4, respectively, and senses the first X current value (Vx1). And a second X current value (Vx2) and the first Y current value (Vy1) and a second Y current value (Vy2). The AC sensing voltage is sequentially given from top to bottom and from left to right, so the sensing current sensed on the X side is from x1 (top) to x2 (bottom). The sensing direction sensed by the Y side is from y1 (left) to y2 (right).

The preliminary coordinate determining unit 44 is configured to determine the preliminary position coordinates (x1, x2, y1, y2) of the contacts P1, P2, P3, P4 sensed by the current sensing unit 43.

On the X-sensing strip or the Y-sensing strip, the above-mentioned contacts P1, P2, P3, P4 are stored, and the distance between the contacts P1, P2, P3, P4 and the current sensing unit 43 will be The determination of the preliminary coordinate determining unit 44 has a considerable influence. When the distance of the contacts is close to the current sensing unit 43, the distance of the sensing current transmitted to the contact is short, so that the impedance on the contact decreases, causing the corresponding current to rise, and vice versa. When the distance of the equal contact is away from the current sensing unit 43, the distance at which the sensing current is transmitted to the contact is far, so that the impedance on the contact rises, causing the corresponding current to drop.

Taking P1 and P2 shown in FIG. 5 as an example, when the user inputs the contact P1 to the projected capacitive touch panel 30, the sense is provided on the X side and the Y side via the sensing voltage supply unit 42. The voltage is measured because the projected capacitive touch panel 30 has a sensing side pattern, and because the contact P1 has a distance between the X side and the Y side and the sensing voltage supply unit 42, the distance is for the sensing side pattern. In this case, an equivalent resistance (not shown) is generated on the X side and the Y side of the contact P1, and the generation of the equivalent resistance will affect the sense that the current sensing unit 43 senses on the contact P1. The current value is so that the current values of Vx2 and Vy1 can be obtained at the contact P1. Similarly, when the user inputs the contact P2 to the projected capacitive touch panel 30, the sensing voltage is provided on the X side and the Y side via the sensing voltage supply unit 42 because the capacitive touch panel 30 is projected. There is a sensing side pattern, and there is a distance between the sensing voltage supply unit 42 on the X side and the Y side due to the contact P2, which is the X side of the contact P2 for the sensing side pattern. An equivalent resistance (not shown) is generated on the Y side, and the generation of the equivalent resistance affects the magnitude of the current sensed by the current sensing unit 43 on the contact P2, so that the contact P2 is available. Current values of Vx1 and Vy2.

Since P1 is closer to the sensing direction of the X-side sensing current than P2, the current value Vx2 obtained at the preliminary coordinate x2 of P1 is higher than the current value Vx1 obtained at the preliminary coordinate x1 of P2, that is, x2> X1. P2 is closer to the sensing direction of the Y-side sensing current than P1, so the current value Vy2 obtained on the preliminary coordinate y2 of P2 is higher than the current value Vy1 obtained on the preliminary coordinate y1 of P1, that is, y2> Y1.

Taking P3 and P4 shown in FIG. 5 as an example, when the user inputs the contact P3 to the projected capacitive touch panel 30, the sense is provided on the X side and the Y side via the sensing voltage supply unit 42. The voltage is measured because the projected capacitive touch panel 30 has a sensing side pattern, and because the contact P3 has a distance between the X side and the Y side and the sensing voltage supply unit 42, the distance is for the sensing side pattern. In this case, an equivalent resistance (not shown) is generated on the X side and the Y side of the contact P3, and the generation of the equivalent resistance will affect the sense that the current sensing unit 43 senses on the contact P3. The current value is so that the current values of Vx1 and Vy1 can be obtained at the contact P3. Similarly, when the user inputs the contact P4 to the projected capacitive touch panel 30, the sensing voltage is provided on the X side and the Y side via the sensing voltage supply unit 42 because the capacitive touch panel 30 is projected. There is a sensing side pattern, and there is a distance between the X side and the Y side and the sensing voltage supply unit 42 which is on the X side and the Y side of the contact P3 for the sensing side pattern. An equivalent resistance (not shown) is generated, and the generation of the equivalent resistance will affect the magnitude of the current sensed by the current sensing unit 43 on the contact P4, so that Vx2 and Vy2 are obtained at the contact P4. Current value.

Since P3 is closer to the sensing direction of the X-side sensing current, the current value Vx1 obtained at the preliminary coordinate x1 of P3 is higher than the current value Vx2 obtained at the preliminary coordinate x2 of P4, that is, x1>x2. Moreover, P3 is also closer to the sensing direction of the Y-side sensing current than P4, so the current value Vy1 obtained on the preliminary coordinate y1 of P3 is higher than the current value Vy2 obtained on the preliminary coordinate y2 of P4, that is, y1 >y2.

With the above described principle, the comparison relationship of the complex array current values can be predefined to create a lookup table for the actual position coordinates to be sought. Take the above as an example to make the following lookup table:

The position coordinate determining unit 45 stores the above-mentioned lookup table. Then, the preliminary coordinates of the contacts P1, P2, P3, and P4 obtained by the preliminary coordinate determining unit 44 by the position coordinate determining unit 45 are further obtained according to the above-mentioned lookup table. The X and Y coordinates x, y of each contact P1, P2, P3, P4 are paired into a complete two-dimensional coordinate to determine the actual position coordinates (x1, y1) of the multi-contact P1, P2, P3, P4. With (x2, y2).

The sixth figure is a flow chart of the method for determining the position of the multi-contact on the projection capacitive touch panel of the present invention, and please cooperate with the description of the fourth to fifth B drawings.

As shown in FIG. 6 , firstly, a plurality of X external wires and Y external wires are provided via the external wire unit 41 and are respectively connected in a one-to-one relationship to a plurality of X sensings on an X side of the projected capacitive touch panel. A plurality of Y sensing strips on the strip and a Y side (S601).

The sensing voltage supply unit 42 sequentially supplies an alternating current sensing voltage Vx to the strips of X sensing strips and the alternating sensing voltage Vy to the strips of sensing strips (S602), wherein the sensing voltage Vs It is sequentially given from top to bottom and from left to right, so as shown in the fifth A and fifth B, the sensing direction of the sensed current sensed on the X side is x1. (upper) to x2 (bottom), the sensing direction sensed on the Y side is from y1 (left) to y2 (right).

Detecting one of the X and Y currents of each of the X and Y sensing strips of the plurality of contacts P1, P2, P3, and P4, respectively, to respectively obtain the at least one set of X current values and the at least one Group Y current value (S603).

Next, the preliminary coordinate determining unit 44 determines the preliminary position coordinates (x1, x2, y1, y2) of the sensed multi-contacts P1, P2, P3, P4 on the X-sensing strip and the Y-sensing strips ( S604).

Finally, the X and Y coordinates of the preliminary position coordinates x and y of the multi-contact P1, P2, P3, and P4 are paired in a lookup table to determine the multi-contact P1, P2, P3, and P4. The actual position coordinates (x1, y1) and (x2, y2) (step 605), wherein the concept of the lookup table establishment has been described above, will now be omitted.

In a different embodiment, the locations of the X and Y transparent sensing layers 32, 34 are interchanged. In a different embodiment, the Y transparent sensing layer 34 is first applied with the alternating sensing voltage Vy, and the X transparent sensing layer 32 is followed by the sensing voltage Vx.

By using the present invention, the position of the multi-contact is completely determined on the capacitive touch panel with the sensing pattern, so that the touch panel can be formally used for multi-touch touch.

The present invention has been described above by way of specific embodiments, and those skilled in the art can devise other possible embodiments by the principles of the embodiments, and the embodiments thus derived are within the spirit of the invention. The actual scope of the invention is defined by the scope of the appended claims.

10. . . Projected capacitive touch panel

11. . . X transparent substrate

12. . . X transparent sensing layer

13. . . Transparent dielectric layer

14. . . Y transparent sensing layer

15. . . Sensing pattern

16. . . X conductive wire diameter

17. . . Y conductive wire diameter

18. . . Sensing board

19. . . External wire

20. . . Sensing device

twenty one. . . Sense voltage source

151. . . X sensor strip

152. . . Y sensor strip

31. . . Substrate

32. . . X transparent sensing layer

33. . . Transparent dielectric layer

34. . . Y transparent sensing layer

37. . . Sensing pattern

40. . . Device for determining multi-contact position

41. . . External conductor unit

42. . . Sense voltage supply unit

43. . . Current sensing unit

44. . . Preliminary coordinate determination unit

45. . . Position coordinate determination unit

59. . . External wire

The first A is a perspective exploded view of a conventional projected capacitive touch panel; the first B and the first C are schematic views of the sensing patterns on the projected capacitive touch panel shown in FIG. A D picture is a top view of the sensing pattern of the first B picture and the first C picture after the overlay; the second figure is a multi-touch on the conventional projection capacitive touch panel shown in the first A picture The top view is a schematic exploded view of the projected capacitive touch panel of the present invention; the fourth figure is a functional block diagram of the projected capacitive touch panel of the present invention; FIG. 5B is a schematic diagram illustrating the determination of the multi-contact position of the projection capacitive touch panel of the present invention; and FIG. 6 is a flow chart of the method for determining the position of the multi-contact on the projection capacitive touch panel of the present invention.

S601~S605. . . Flow chart step description

Claims (8)

A device for determining a multi-contact position of a projected capacitive touch panel, the device for determining a position of a multi-contact comprises: an external lead unit, respectively providing a plurality of X and Y external wires and a pair in a one-to-one relationship a plurality of X sensing strips on the X transparent sensing layer and a plurality of Y sensing strips on a Y transparent sensing layer are connected; a sensing voltage supply unit is configured to sequentially provide an AC sensing voltage to The plurality of X sensing strips are sequentially provided with the alternating sensing voltage to the plurality of Y sensing strips; a current sensing unit is configured to sequentially sense the X and Y sensing strips respectively One X current and one Y current on each to obtain the at least one set of X current values and the at least one set of Y current values respectively; a preliminary coordinate determining unit for determining that the current sensing unit is sensed a preliminary coordinate of the contact; and a position coordinate determining unit, wherein the position coordinate determining unit stores a lookup table, and the position coordinate determining unit pairs the preliminary coordinates of the contacts obtained by the preliminary coordinate determining unit according to the lookup table To determine the touch The actual position coordinates, wherein the lookup table of contents contains preliminary coordinate comparative relationship, than with the initial coordinates The actual position coordinates corresponding to the relationship. The apparatus for determining a multi-contact position of the projection capacitive touch panel of claim 1, wherein the content of the lookup table is a size relationship between the X coordinates x of the preliminary positions of the contacts and a Y coordinate Corresponding combination of size relationships between y. The apparatus for determining a multi-contact position of the projection capacitive touch panel of claim 1 is wherein the positions of the X and Y transparent sensing layers are interchanged. The device for determining a multi-contact position of the projection capacitive touch panel of claim 1, wherein the X transparent sensing layer is first applied with the sensing voltage, and the Y transparent sensing layer is followed by the sensing Voltage. A method for determining a multi-contact position of a projected capacitive touch panel, the method comprising the steps of: providing a plurality of X external wires and a plurality of Y external wires, respectively, for electrically connecting the projection capacitors in a one-to-one relationship One of the X touch panels is a plurality of X sensing strips on the transparent sensing layer and a plurality of Y sensing strips on the Y transparent sensing layer; an alternating sensing voltage is sequentially provided to the strips of X sensing Providing the alternating sensing voltage to the strips of the sensing strips, and sequentially sensing at least one contact on each of the X and Y sensing strips, an X current and a Y Current to obtain the at least one set of X a current value and the at least one set of Y current values; determining a preliminary position coordinate of the X sense strip and the Y sense strip sensed on the touch strip; and determining the contact points according to a lookup table The preliminary position coordinates are paired to determine the actual position coordinates of the contacts, wherein the contents of the lookup table include a preliminary coordinate comparison relationship and an actual position coordinate corresponding to the preliminary coordinate comparison relationship. The method for determining a multi-contact position of a projection capacitive touch panel according to claim 5, wherein the content of the lookup table is a size relationship between the X coordinates x of the preliminary positions of the contacts and a Y coordinate Corresponding combination of size relationships between y. The method for determining a multi-contact position of a projection capacitive touch panel of claim 5, wherein the positions of the X and Y transparent sensing layers are interchanged. The method for determining a multi-contact position of the projection capacitive touch panel of claim 5, wherein the X transparent sensing layer is first applied to the sensing voltage, and the Y transparent sensing layer is post-sensed Voltage.