JP2009015685A - Touch panel device and its operation information generation method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a touch panel device capable of detecting a contact position and electrostatic capacitance of an object inexpensively and having a touch panel thinner than that in a conventional technology. <P>SOLUTION: The touch panel device is provided with: the touch panel 10; a coordinate detection circuit 22; and an electrostatic capacitance detection circuit 23. The touch panel 10 has: a pair of transparent resistance films 11a, 11b opposite to each other; a pair of electrodes 111a, 112a on both edges in the X direction of the transparent resistance film 11a; and a pair of electrodes 111b, 112b on both edges in the Y direction of the transparent resistance film 11b. The coordinate detection circuit 22 applies predetermined voltage between the electrodes 111a and 112a (between the second electrodes 111b and 112b), detects the voltage of the electrode 112b (electrode 112a) and senses an X coordinate (Y coordinate). The electrostatic capacitance detection circuit 23 commonly connects the electrodes 111a, 112a, 111b, 112b and detects the electrostatic capacitance between the touch panel 10 and the contact object. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a touch panel device that detects contact of an object, and more particularly, to a touch panel device that can detect a plurality of contact states and an operation information generation method thereof.

  Conventionally, there are two types of touch panel detection methods: a resistive film method and a capacitance method. Here, in the resistive film method, a pair of opposing resistive films are provided as a touch panel that senses contact of an object. These resistance films are normally separated from each other, and are brought into contact with each other at the pressing position by external pressing. The resistance film method is a method of detecting a position touched by such pressing (touch) by a voltage applied to both ends of one resistance film and a voltage detected by the other resistance film.

  On the other hand, in the capacitive method, a conductive film and an insulating film disposed on the conductive film are provided as a touch panel. Here, when a user's finger touches the insulating film, a capacitor is constituted by the conductive film and the finger (functioning as an electrode). The capacitance method is a method for detecting a change in the capacitance of the capacitor.

  A touch panel device that combines the two methods described above is disclosed in Patent Document 1. According to this touch panel, capacitance information can be obtained in addition to contact position information. For example, an operation with a finger with a sack and an operation with a finger without a sack can be identified. Can be identified.

However, the touch panel device described in Patent Document 1 has a structure in which a resistive touch panel (a pair of resistive films) for resistive film type and an electrostatic touch panel (conductive film, insulating film) for capacitive type are stacked. Have. That is, the thickness of the touch panel as a whole is thicker than the configuration of only the resistive film type or the configuration of only the capacitive type. Moreover, since a resistance touch panel and an electrostatic touch panel are required, there is a problem that the manufacturing cost increases.
JP 7-334308 A

  An object of the present invention is to provide a touch panel device having a touch panel that can detect the contact position and capacitance of an object at a low cost and is thinner than the prior art, and a method for generating operation information thereof.

  A touch panel device according to the present invention includes a first resistance film and a second resistance film that are disposed to face each other with a predetermined gap therebetween, a first electrode pair that is disposed at both ends in the first direction of the first resistance film, and A predetermined voltage is applied between the first electrode pair and a resistive film type touch panel having a second electrode pair disposed at both ends of the second resistance film in a second direction orthogonal to the first direction. And a first direction position detecting means for detecting a contact position in the first direction of the contact object on the touch panel by detecting a voltage of the second electrode pair when the touch panel is pressed by the contact object. , Applying a predetermined voltage between the second electrode pair, and detecting the voltage of the first electrode pair when the touch panel is pressed by the contact object, thereby detecting the second of the contact object in the touch panel. Directional contact position A second direction position detecting means for detecting the capacitance, and a capacitance detecting means for detecting the capacitance between the touch panel and the contact object by commonly connecting the first electrode pair and the second electrode pair. And output means for outputting the contact position information detected by the first direction position detection means and the second direction position detection means and the capacitance detected by the capacitance detection means as operation information. It is characterized by.

  According to the present invention, it is possible to provide a touch panel device that has a touch panel that can detect the contact position and capacitance of an object at a low cost and is thinner than the prior art, and an operation information generation method thereof.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing a touch panel device according to an embodiment of the present invention.

  As shown in FIG. 1, the touch panel device includes a touch panel 10 in which upper and lower resistive films are brought into contact with an object and an electrostatic capacitance is changed between the object and the touch panel 10. And a control unit 20 that generates operation information based on the received signal. The operation information is information regarding the position where the object of the touch panel 10 is in contact and the capacitance between the object and the touch panel.

  The touch panel 10 includes a surface film 12 and a glass plate 13 made of a transparent insulator and arranged to face each other with a predetermined gap, and a first transparent resistance film formed on each of the facing surfaces of the surface film 12 and the glass plate 13. 11a and a second transparent resistance film 11b. The surface film 12 and the glass plate 13 form a predetermined gap by bonding their peripheral portions through a bonding material 15. Further, on the surface of the second transparent resistance film 11b, dot spacers 14 made of an insulator are disposed at a predetermined interval in the surface direction, and the first transparent resistance film 11a and the second transparent resistance film 11b are arranged by the dot spacers 14. To prevent contact with each other under normal conditions. The surface film 12 has flexibility, is curved by pressing an object such as a finger, and contacts the second transparent resistance film 11b at the curved portion. The first transparent resistance film 11 a and the second transparent resistance film 11 b are electrically connected to the control unit 20 via the connector 16.

  FIG. 2 is a diagram for explaining the principle of contact position detection of the touch panel 10.

  The first transparent resistance film 11a includes a first electrode 111a and a second electrode 112a that form a first electrode pair at both ends in the X direction. The second transparent resistance film 11b has a first electrode 111b and a second electrode 112b constituting a second electrode pair at both ends in the Y direction orthogonal to the X direction.

  For example, if the position of P1 in the figure is pressed while the power supply voltage V and the ground voltage 0V are applied to the first electrode pair 111a and 112a, respectively, the resistance value from the first electrode 111a to P1 is Rx1, Since the resistance value from P1 to the second electrode 112a is Rx2, the potential of P1 is V * Rx2 / (Rx1 + Rx2). If the second transparent resistance film 11b is used as the detection electrode, this voltage is changed in the X direction. The contact position can be detected on the second electrode pair 111b, 112b side.

  Similarly, if the position of P1 in the figure is pressed while the power supply voltage V and the ground voltage 0 V are applied to the second electrode pair 111b and 112b, respectively, the resistance value from the first electrode 111b to P1 is Ry1, Since the resistance value from P1 to the second electrode 112b is Ry2, the potential of P1 is V * Ry2 / (Ry1 + Ry2). If the first transparent resistance film 11a is used as the detection electrode, this voltage is reduced in the Y direction. The contact position can be detected on the first electrode pair 111a, 112a side.

  Next, the configuration of the control unit 20 will be described with reference to FIG. As shown in FIG. 3, the control unit 20 mainly includes a power source 21, a coordinate detection circuit 22, a capacitance detection circuit 23, a switching circuit 24, an operation control circuit 25, and a storage unit 26.

  The coordinate detection circuit 22 detects a voltage based on a change in the resistance value of each of the first and second transparent resistance films 11a and 11b, and detects a contact position coordinate of an object on the touch panel 10, for example, analog-digital conversion. An X-coordinate detection unit 221 and a Y-coordinate detection unit 222 that are configured by an analog (ADC: Analog Digital Converter).

  The X coordinate detection unit 221 inputs the voltage of the second electrode 112b when a predetermined voltage is applied between the pair of electrodes 111a and 112a and the touch panel 10 is pressed by the contact object, and the X of the contact object on the touch panel 10 is detected. Outputs the contact position coordinates in the direction.

  The Y coordinate detection unit 222 inputs a voltage of the second electrode 112a when a predetermined voltage is applied between the pair of electrodes 111b and 112b and the touch panel 10 is pressed by the contact object, and the Y of the contact object on the touch panel 10 is input. Outputs the contact position coordinates in the direction.

  The capacitance detection circuit 23 detects the capacitance between the touch panel 10 and the contact object when the pair of electrodes 111a and 112a and the pair of electrodes 111b and 112b are connected in common. That is, the capacitance detection circuit 23 causes the first and second transparent resistance films 11a and 11b to function as one electrode film by common connection.

  The capacitance detection circuit 23 includes a capacitor 231, a charge pump switch 232a, a reset switch 232b, a DA converter 233, a comparator 234, an input port 235, and a counter 236.

  One end of the capacitor 231 is grounded, and the other end of the capacitor 231 is connected to the first node N1. The charge pump switch 232a alternately connects the first and second transparent resistance films 11a and 11b to the power source 21 and the first node N1. The reset switch 232b is provided between the first node N1 and the ground potential, and discharges the charge of the first node N1. The DA converter 233 outputs a predetermined threshold signal converted into an analog signal to the comparator 234. The comparator 234 receives the signal from the first node N1 and the predetermined threshold signal output from the DA converter 233, and outputs a signal obtained by comparing these signals. The input port 235 receives the signal output from the comparator 234 and outputs a digital signal based on the signal. The counter 236 counts the digital signal output from the input port 235. The charge pump switch 232a and the reset switch 232b are controlled by the operation control circuit 25.

  The switching circuit 24 controls switching of signals output from the touch panel 10 and input to the coordinate detection circuit 22 or the capacitance detection circuit 23.

  The changeover circuit 24 includes first to tenth changeover switches 241a to 241j. The first to tenth changeover switches 241 a to 241 j are controlled by the operation control circuit 25.

  The first changeover switch 241a is provided between the power supply 21 and the second node N2 to which the first electrode 111a of the first transparent resistance film 11a is connected. The second changeover switch 241b is provided between the third node N3 connected to the second electrode 111b of the second transparent resistance film 11b and the power supply 21. The third changeover switch 241c is provided between the fourth node N4 connecting the second electrode 112a of the first transparent resistance film 11a and the ground potential. The fourth changeover switch 241d is provided between the fifth node N5 connected to the second electrode 112b of the second transparent resistance film 11b and the ground potential. The fifth changeover switch 241e is provided between the fifth node N5 and the X coordinate detection unit 221. The sixth changeover switch 241f is provided between the fourth node N4 and the Y coordinate detection unit 222. The seventh changeover switch 241g is provided between the second node N2 and the third node N3. The eighth changeover switch 241h is provided between the fourth node N4 and the fifth node N5. The ninth changeover switch 241i is provided between the third node N3 and the fifth node N5. The tenth changeover switch 241j is provided between the third node N3 and one end of the charge pump switch 232a.

  The operation control circuit 25 controls the charge pump switch 232a, the reset switch 232b, and the first to tenth changeover switches 241a to 241j in accordance with a measurement mode to be described later, as well as output data from the coordinate detection circuit 22, and capacitance Output data from the detection circuit 23 is received, operation information is generated from the received information, and output to the outside.

  Next, the operation of the operation control circuit 25 will be described with reference to FIG. FIG. 4 is a flowchart showing the operation of the operation control circuit 25.

  First, the operation control circuit 25 switches the switching circuit 24 to the contact detection mode (step S101). Subsequently, the operation control circuit 25 determines whether or not an object is in contact with the first transparent resistance film 11a in the contact detection mode (step S102).

  In step S102, when the operation control circuit 25 determines that no object is in contact with the first transparent resistance film 11a (step S102, N), the operation control circuit 25 repeatedly performs the operation of step S102. On the other hand, when the operation control circuit 25 determines in step S102 that the object is in contact with the first transparent resistance film 11a (step S102, Y), the switching circuit 24 is switched to the X coordinate resistance detection mode (step S103). . Subsequently, the operation control circuit 25 stores the X coordinate detected in the X coordinate resistance detection mode in the storage unit 26 (step S104).

  Following step S104, the operation control circuit 25 switches the switching circuit 24 to the Y coordinate detection mode (step S105). Subsequently, the operation control circuit 25 stores the Y coordinate detected in the Y coordinate resistance detection mode in the storage unit 26 (step S106).

  Following step S106, the operation control circuit 25 switches the switching circuit 24 to the capacitance detection mode (step S107). Subsequently, the operation control circuit 25 determines whether or not the capacitance is equal to or greater than a predetermined value (step S108). Here, if the operation control circuit 25 determines that the capacitance is equal to or greater than a predetermined threshold (step S108, Y), after determining that the capacitance is in the first state, the operation control circuit 25 stores the data in the storage unit 26 ( Step S109). On the other hand, if the operation control circuit 25 determines that the capacitance is not equal to or greater than the predetermined threshold value (step S108, N), it stores the data in the storage unit 26 after determining that it is in the second state (step S110). ). Then, after the operation of step S109 or step S110, the operation control circuit 25 outputs the operation information obtained as described above (step S111). After step S111, the operation control circuit 25 returns to the operation of step S101 again.

  Next, the contact detection mode, the X coordinate detection mode, the Y coordinate detection mode, and the capacitance detection mode described above will be described with reference to FIG. FIG. 5 is a time chart showing operations of the first to tenth changeover switches 241a to 241j, the charge pump switch 232a, and the reset switch 232b.

  First, the contact detection mode executed in step S101 and step S102 will be described. In the contact detection mode, the first, fourth, and sixth changeover switches 241a, 241d, and 241f are turned on, and the second, third, fifth, and seventh to tenth changeover switches 241b, 241c, 241e and 241g to 241j are set to the “off” state. That is, the first electrode 111a of the first transparent resistance film 11a is connected to the power source 21, and the second electrode 112b of the second transparent resistance film 11b is connected to the ground. Then, the Y coordinate detection unit 222 detects a current value or a voltage change that flows when the first transparent resistance film 11a and the second transparent resistance film 11b come into contact with each other. At this time, the Y coordinate detection unit 222 functions as a contact detection unit. The operation control circuit 25 determines whether or not the object is in contact based on the output signal from the Y coordinate detection unit 222. If the object is in contact, the operation control circuit 25 shifts to the X coordinate detection mode. This contact detection mode can also be realized by setting the fifth changeover switch 241e to “on” and the sixth changeover switch 241f to “off” and detecting a voltage change by the X coordinate detection unit 221. In this case, when the first transparent resistance film 11a and the second transparent resistance film 11b come into contact with each other, the X coordinate detection unit 221 detects a voltage change corresponding to a voltage drop due to the ON resistance of the fourth changeover switch 241d. It will be.

  Next, the X coordinate detection mode executed in steps S103 and S104 will be described. As shown in FIG. 5, in the X coordinate detection mode, the third changeover switch 241c is switched to the “on” state and the fourth changeover switch 241d is switched to the “off” state from the contact detection mode. That is, the first electrode 111a of the first transparent resistance film 11a is connected to the power source 21, and the second electrode 112a is connected to the ground. Further, the first electrode 111b of the second transparent resistance film 11b and the power source 21 are not connected, and the second electrode 112b and the ground are not connected. The voltage of the second electrode 112b of the second transparent resistance film 11b is detected by the X coordinate detection unit 221. The operation control circuit 25 stores the contact position of the object at the X coordinate in the storage unit 26 based on the output signal from the X coordinate detection unit 221.

  Next, the Y coordinate detection mode executed in step S105 and step S106 will be described. As shown in FIG. 5, in the Y-coordinate detection mode, the first, third, and fifth change-over switches 241a, 241c, and 241e are switched to the “off” state from the first resistance detection mode, and the second and fourth The sixth changeover switches 241b, 241d, and 241f are switched to the “on” state. That is, the first electrode 111b of the second transparent resistance film 11b is connected to the power source 21 and the second electrode 112b is connected to the ground. Further, the first electrode 111a of the first transparent resistance film 11a and the power source 21 are not connected, and the second electrode 112a and the ground are not connected. Then, the voltage of the second electrode 112a of the first transparent resistance film 11a is detected by the Y coordinate detection unit 222. The operation control circuit 25 stores the contact position of the object at the Y coordinate in the storage unit 26 based on the output signal from the Y coordinate detection unit 222.

  Subsequently, the capacitance detection mode executed in steps S107 and S108 will be described. As shown in FIG. 5, in this capacitance detection mode, from the Y coordinate detection mode, the second, fourth, and sixth changeover switches 241b, 241d, and 241f are switched to the “off” state, The ten changeover switches 241g to 241j are switched to the “on” state. Further, the charge pump switch 232a is alternately switched between a “1” state and a “0” state every predetermined time, and the reset switch 232b is switched to an “off” state. That is, the electrodes 111a, 112a, 111b, and 112b are connected in common to form one electrode film. Then, a charge is supplied from the power source 21 to the capacitor C formed between the electrode film and the object in contact with it, and then the charge pump switch 232a is switched to the capacitor 231 side, thereby charging the capacitor C. Is distributed to the capacitor 231. By repeating this, the potential of the node N1 rises to the power supply voltage. The rising speed at that time depends on the capacitance of the capacitor C formed between the electrode film and the object. Therefore, the comparator 234 compares the voltage at the node N1 with a predetermined voltage, and the counter 236 measures the time from the start of measurement until the output of the comparator 234 changes. Thereby, the capacitance of the capacitor C is detected, and the determination result of the capacitance is stored in the storage unit 26. Then, the X and Y coordinate values and the capacitance magnitude determination values stored in the storage unit 26 are output to the outside as operation information.

  Next, as an example, a predetermined used for the comparison of the comparator 234 in the case of discriminating the contact of the human finger belly T1 as shown in FIG. 6 and the contact of the human fingernail T2 as shown in FIG. The value will be described.

FIG. 8 shows measurement results obtained by measuring a capacitance due to contact with the finger belly T1 and a capacitance due to contact with the fingernail T2 over a plurality of times using the touch panel device according to the present embodiment. . As shown in FIG. 8, it can be seen that the contact of the finger belly T1 and the contact of the fingernail T2 can be distinguished from the change in capacitance. Therefore, for example, as shown in the following formula (1), the predetermined value used for the comparison of the comparator 234 is an average using the maximum value and the minimum value of the capacitance change of the finger belly T1 and the fingernail T2. It can be obtained by the value method. In Equation (1), D _{f, n} is a predetermined value used for contact identification between the finger belly T1 and the finger nail T2, and L _f is a capacitance change due to the contact between the finger belly T1. H _n is the minimum value, and H _n is the maximum value of the capacitance change upon contact with the fingernail T2.

  As described above, the touch panel device according to an embodiment of the present invention performs the configuration and operation as described above. That is, when an object touches the touch panel 10, the coordinate detection circuit 22 detects the touch position (X coordinate, Y coordinate) of the touch panel 10, and outputs the position information of the touched object as operation information in the operation control circuit 25. can do. At the same time, when an object comes into contact with the touch panel 10, the capacitance detection circuit 23 detects the capacitance of the touch panel 10, and further the state of the object (for example, a finger belly T 1 or a finger nail T 2 Can be output as operation information by the operation control circuit 25.

  The touch panel 10 can detect the contact position and the capacitance of the object only by the first transparent resistance film 11a and the second transparent resistance film 11b by commonly connecting the electrodes 111a, 112a, 111b, and 112b. There is no need to arrange an electrostatic touch panel as in the prior art. That is, the touch panel 10 can be designed to be thinner than before, and can be provided at a low cost.

  Moreover, in this embodiment, since the contact of a finger | toe of a finger | toe or a fingernail is identifiable, two types of determination can be performed by one contact. Therefore, for example, a detailed description of the operation may be displayed in the form of a balloon according to the contact of the fingernail, and the operation may be determined according to the contact of the finger belly. That is, according to this embodiment, the selection menu displayed on the screen can be reduced, a clean and easy-to-see screen can be presented, and an intuitive operation can be performed.

  As mentioned above, although one Embodiment of this invention was described, this invention is not limited to this, A various change, addition, and substitution are possible in the range which does not deviate from the meaning of invention. For example, in the contact detection mode of the above embodiment, the first electrode 111a is connected to the power source 21 and the second electrode 112b is connected to the ground, and the Y coordinate detection unit 222 detects the first electrode. 111b may be connected to the power source 21, and the second electrode 112b may be connected to the ground and detected by the X coordinate detection unit 221.

It is sectional drawing of the touchscreen apparatus which concerns on one Embodiment of this invention. It is a figure which shows schematic structure of the 1st transparent resistive film 11a and the 2nd transparent resistive film 11b of the touchscreen apparatus which concerns on one Embodiment of this invention. It is a circuit diagram of the touch panel device concerning one embodiment of the present invention. It is a flowchart figure which shows operation | movement of the operation control circuit 25 of the touchscreen apparatus which concerns on one Embodiment of this invention. It is a time chart which shows operation | movement of the switching circuit 24 which concerns on one Embodiment of this invention. It is the figure which showed the usage example in the touchscreen apparatus which concerns on one Embodiment of this invention. It is the figure which showed the usage example in the touchscreen apparatus which concerns on one Embodiment of this invention. In the touch panel device concerning one embodiment of the present invention, it is a figure showing electrostatic capacity at the time of making finger touch T1 contact touch panel 10, and electrostatic capacity at the time of making finger nail T2 contact touch panel 10. is there.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Touch panel, 11a ... 1st transparent resistive film, 111a, 112a ... 1st electrode, 11b ... 2nd transparent resistive film, 111b, 112b ... 2nd electrode, 12 ... Surface film, 13 ... Glass plate, 14 ... Dot spacer 15 ... Adhesive member, 16 ... Connector, 20 ... Control unit, 21 ... Power source, 22 ... Coordinate detection circuit, 221 ... X coordinate detection unit, 222 ... Y coordinate detection unit, 23 ... Capacitance detection circuit, 231 ... Capacitor 232a ... charge pump switch, 232b ... reset switch, 233 ... DA converter, 234 ... comparator, 235 ... input port, 236 ... counter, 24 ... switching circuit, 241a to 241j ... first to tenth changeover switches, 25 ... Operation control circuit, 26... Storage unit, N1 to N5... First to fifth nodes, P1.

Claims (4)

The first resistance film and the second resistance film disposed to face each other with a predetermined gap therebetween, the first electrode pair disposed at both ends in the first direction of the first resistance film, and the first resistance film of the second resistance film A resistive film type touch panel including a second electrode pair disposed at both ends in a second direction orthogonal to the one direction;
Applying a predetermined voltage between the first electrode pair, and detecting the voltage of the second electrode pair when the touch panel is pressed by the contact object, the first direction of the contact object on the touch panel First direction position detecting means for detecting the contact position of
Applying a predetermined voltage between the second electrode pair, and detecting the voltage of the first electrode pair when the touch panel is pressed by the contact object, the second direction of the contact object on the touch panel A second direction position detecting means for detecting the contact position of
A capacitance detecting means for commonly connecting the first electrode pair and the second electrode pair to detect a capacitance between the touch panel and the contact object;
Output means for outputting the contact position information detected by the first direction position detection means and the second direction position detection means and the capacitance detected by the capacitance detection means as operation information. A featured touch panel device. Between one of the first electrode pairs and a power source, between the other of the first electrode pair and ground, between one of the second electrode pair and a power source, and the other of the second electrode pair. And a switching circuit for selectively connecting the first electrode pair and the second electrode pair together, and selectively connecting each of the first electrode pair and the ground.
The first direction position detecting means connects the one of the first electrode pair and the power source and the other of the first electrode pair and the ground by the switching circuit, respectively, and By detecting the voltage of one of the second electrode pairs in a state where the connection between one of the electrode pairs and the power source and the other of the second electrode pair and the ground are respectively disconnected. Detecting the contact position of the contact object in the first direction on the touch panel;
The second direction position detecting means connects the one of the second electrode pair and the power source and the other of the second electrode pair and the ground by the switching circuit, respectively. By detecting the voltage of one of the first electrode pair in a state where the connection between one of the electrode pair and the power source and the other of the first electrode pair and the ground are not connected, respectively. The touch panel device according to claim 1, wherein the touch position of the touch object on the touch panel is detected in the second direction.   A power supply is connected to one of the first electrode pair and the second electrode pair, and a ground is connected to the other, and a current value or a voltage change flowing when the first resistance film and the second resistance film are in contact is detected. The touch panel device according to claim 1, further comprising contact detecting means for performing the operation. A contact detection step of detecting contact of a contact object with the touch panel;
A first direction position detecting step of detecting a contact position of the contact object in the first direction to the touch panel;
A second direction position detection step of detecting a contact position of the contact object in the second direction to the touch panel;
The operation information generating method using the touch panel device according to claim 3, further comprising a capacitance measuring step of measuring a capacitance between the touch panel and the contact object.

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