Touch panel and position detection method

Abstract

To provide a touch panel and a position detection method, capable of detecting a position with high accuracy even when having a button area.SOLUTION: A touch panel 1 includes lower and upper substrates 30 and 10 having an operation area 12 and button areas 11 and 13 adjacent to the operation area in an X direction. The button areas include a plurality of buttons 11a-11d and 13a-13d arranged in a Y direction intersecting the X direction. The lower substrate includes a pair of electrodes 31 and 32 for applying voltage in the Y direction, and the upper substrate includes a pair of electrodes 14 and 17 arranged along the outer periphery of the operation area in the Y direction, first etching patterns 16 and 19 formed between the electrodes close to the button areas in the pair of electrodes 14 and 17 and the button areas and electrodes 15 and 18 formed in the button areas.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a touch panel and a position detection method.

Background Art

[0002] Conventionally, a resistive film type touch panel including a substrate having electrodes arranged at both ends in the X direction and a substrate having electrodes arranged at both ends in the Y direction is known. Also, a touch panel in which a plurality of operation regions are formed by dividing the resistive film on the substrate is known.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0004] Recently, touch panels of various shapes have been demanded. For example, a convex touch panel is used in a POS (Point Of Sales) terminal, a kiosk terminal, a car navigation terminal, or the like. In this case, an operation unit is often arranged in the center, button regions are often arranged in the left and right protruding portions, and the button regions may have a plurality of buttons arranged in a plurality of rows and columns, so high-precision position detection is required.

[0005] However, if electrodes are placed at both ends of the upper substrate in the left-right direction (X direction), the electrodes will sandwich the left button area, the operation area, and the right button area. In this case, the resolution corresponding to the operation area (the ability to detect position with fine precision) will decrease compared to when the electrodes are placed so as to sandwich only the operation area. In addition, in irregularly shaped touch panels that are not rectangular, the curvature of equipotential lines may reduce the accuracy of position detection.

[0006] This disclosure has been made in view of the above-mentioned problems, and provides a touch panel and a position detection method that can perform position detection with high accuracy even when a button area is present. [Means for solving the problem]

[0007] The touch panel of the present disclosure comprises a first substrate having a first conductive film and a second substrate having a second conductive film disposed opposite to the first conductive film, wherein both the first and second substrates have an operating area and a button area adjacent to the operating area in a first direction, the button area includes a plurality of buttons, the second substrate has a pair of first electrodes for applying a voltage in a second direction intersecting the first direction, the first substrate is characterized by having a pair of second electrodes disposed along the outer circumference of the operating area for applying a voltage in the first direction, a first etching pattern formed on the first conductive film between the electrode of the pair of second electrodes closest to the button area and the button area, and a third electrode formed on the button area. [Effects of the Invention]

[0008] According to this disclosure, position detection can be performed with high accuracy even when a button area is present. [Brief explanation of the drawing]

[0009] [Figure 1] This is a configuration diagram showing an example of a touch panel device according to the first embodiment. [Figure 2] (A) is a diagram showing the configuration of the upper circuit board of the touch panel, and (B) is a diagram showing the configuration of the lower circuit board of the touch panel. [Figure 3] (A) is a cross-sectional view of line AA in Figures 2(A) and (B), and (B) is a cross-sectional view of line BB in Figures 2(A) and (B). [Figure 4] This is a flowchart showing the processes performed by the control unit. [Figure 5] (A) is a diagram showing the configuration of the upper substrate of the touch panel according to the first modified example, and (B) is a diagram showing the configuration of the lower substrate of the touch panel according to the first modified example. [Figure 6] (A) is a diagram showing the configuration of the upper circuit board of the touch panel according to the second modified example, and (B) is a diagram showing the configuration of the lower circuit board of the touch panel according to the second modified example. [Figure 7] (A) is a diagram showing the configuration of the upper circuit board of the touch panel according to the third modified example, and (B) is a diagram showing the configuration of the lower circuit board of the touch panel according to the third modified example. [Figure 8] This flowchart shows the processes performed by the control device according to the third modified example. [Figure 9] (A) is a diagram showing the configuration of the upper substrate of the touch panel according to the second embodiment, and (B) is a diagram showing the configuration of the lower substrate of the touch panel according to the second embodiment. [Figure 10] This flowchart shows the process performed by the control device according to the second embodiment. [Modes for carrying out the invention]

[0010] Embodiments of the present invention will be described below with reference to the drawings.

[0011] (First Embodiment) FIG. 1 is a configuration diagram showing an example of a touch panel device. The touch panel device includes a touch panel 1 and a control device 2. The touch panel 1 is a resistive film type touch panel. The control device 2 has a processor 3 such as a DSP (Digital Signal Processor), an ADC (AD converter) 4 that converts the potential corresponding to the pressed point into a digital value, a ROM (Read Only Memory) 5 storing a program for driving the processor 3, and a RAM (Random Access Memory) 6 that functions as a work memory. The processor 3 and the ADC 4 are connected to the touch panel 1. Also, the processor 3 is connected to the ADC 4, the ROM 5, and the RAM 6 via a bus 7. Although only one ADC 4 is shown, a plurality of ADCs are provided.

[0012] When the processor 3 reads a program from the ROM 5 at power-on, for example, it controls a switch for driving the touch panel 1. The ADC 4 detects the potential of the pressed point within the input surface of the touch panel 1, and the processor 3 detects the coordinates of the pressed point based on the potential detected by the ADC 4.

[0013] FIG. 2(A) is a diagram showing the configuration of the upper substrate of the touch panel 1, and FIG. 2(B) is a diagram showing the configuration of the lower substrate of the touch panel 1. In FIGS. 2(A) and 2(B), the left-right direction is taken as the X direction (first direction), the up-down direction is taken as the Y direction (second direction), and the X direction intersects (is orthogonal) with the Y direction.

[0014] The shapes of the upper substrate 10 (first substrate) and the lower substrate 30 (second substrate) of the touch panel 1 are rectangular. The upper substrate 10 is made of, for example, a PET (polyethylene terephthalate) film, and the lower substrate 30 is made of, for example, glass. As shown in FIG. 2(A), in the touch panel 1, an operation area 12 is provided in the center, a first button area 11 is provided to the left adjacent to the operation area 12, and a second button area 13 is provided to the right adjacent to the operation area 12.

[0015] A rectangular area 12a arranged at the center of the operation area 12 is an area capable of detecting a pressing point. The first button area 11 includes a plurality of buttons 11a and 11b arranged in a column in the Y direction, and the second button area 13 includes a plurality of buttons 13a and 13b arranged in a column in the Y direction. The rectangular area 12a, buttons 11a, 11b, 13a, and 13b are shown in the drawings for convenience of explanation, but these are not necessarily shown visibly on the actual touch panel 1. Also, in the operation area 12, the coordinates of the pressing point within the rectangular area 12a are detected, and in the first button area 11 and the second button area 13, the pressing of each button is detected. In the first button area 11 and the second button area 13 in FIGS. 2(A) and (B), the Y coordinate of the pressing point is detected, but the X coordinate of the pressing point is not detected.

[0016] In the operation area 12, a pair of electrodes 14 and 17 (second electrode) are arranged along the Y direction of the rectangular area 12a. An etching pattern 16 (first etching pattern) is formed at the boundary between the first button area 11 and the operation area 12 to insulate the first button area 11 and the operation area 12, and the electrode 14 is formed between the etching pattern 16 and the rectangular area 12a. The first button area 11 includes an electrode 15 (third electrode) for detecting potential. An etching pattern 19 (first etching pattern) is formed at the boundary between the second button area 13 and the operation area 12 to insulate the second button area 13 and the operation area 12, and the electrode 17 is formed between the etching pattern 19 and the rectangular area 12a. The second button area 13 includes an electrode 18 (third electrode) for detecting potential. The etching pattern is provided to individually control the button area and the operation area. In this embodiment, the third electrode is substantially L-shaped, but as long as the potential of the opposing transparent conductive film can be detected, the length and shape are not limited.

[0017] Switches 21-24 are composed of transistors, for example. The bases of switches 21-24 are connected to processor 3 and are controlled on / off by processor 3. The power supply voltage Vcc is applied to the emitter of switch 21, and electrode 17 is connected to the collector of switch 21. Electrodes 15, 14, and 18 are connected to the emitters of switches 22-24, respectively. Multiple ADCs 4 are connected to the emitters of switches 22-24, and the collectors of switches 22-24 are grounded.

[0018] As shown in Figure 2(B), in the lower substrate 30, the electrode 31 (first electrode) is linear and is arranged along the X direction of button 11a, rectangular area 12a, and button 13a. The electrode 32 (first electrode) is convex and is arranged along the X direction on the -Y side of button 11b, rectangular area 12a, and button 13b. This prevents the detection of button presses in areas other than the buttons.

[0019] Switches 41 and 42 are composed of transistors, for example. The bases of switches 41 and 42 are connected to the processor 3 and are controlled on and off by the processor 3. The power supply voltage Vcc is applied to the emitter of switch 41, and electrode 31 is connected to the collector of switch 41. Electrode 32 is connected to the emitter of switch 42. An ADC 4 is connected to the emitter of switch 42, and the collector of switch 42 is grounded. Note that the connections of each switch and each electrode are not limited to the example shown in the figure, as long as the potential can be detected as described above.

[0020] Figure 3(A) is a cross-sectional view of line AA in Figures 2(A) and (B), and Figure 3(B) is a cross-sectional view of line BB in Figures 2(A) and (B).

[0021] The upper substrate 10 and lower substrate 30 of the touch panel 1 face each other with a space between them. An icon sheet 55 with icons and decorations printed on it is attached to the upper surface of the upper substrate 10. A transparent conductive film 51 (first conductive film) of indium tin oxide (ITO) is formed on the lower surface of the upper substrate 10, and a transparent conductive film 52 (second conductive film) of ITO is formed on the upper surface of the lower substrate 30.

[0022] As shown in Figures 3(A) and (B), an insulating layer 54 is formed on the transparent conductive film 52, and double-sided tape 53 is placed between the insulating layer 54 and the transparent conductive film 51 to bond them together. As shown in Figure 3(A), the electrode 31 is formed on the transparent conductive film 52, and the thickness of the electrode 31 is thinner than the thickness of the insulating layer 54. A dot spacer (not shown) is placed on the transparent conductive film 52.

[0023] As shown in Figure 3(B), double-sided tape 53 and an insulating layer 54 are also provided between the first button area 11 and the operating area 12. The etching pattern 16 is formed on the transparent conductive film 51 between the first button area 11 and the operating area 12. The etching pattern 16 is formed between the first button area 11 and the electrode 14. The electrode 14 is formed beneath the transparent conductive film 51, and the thickness of the electrode 14 is thinner than the thickness of the double-sided tape 53.

[0024] Returning to Figures 2(A) and (B), when processor 3 detects the X-coordinate of the pressed point within the rectangular region 12a, it turns on switches 21 and 23 and turns off switches 41 and 42. As a result, the power supply voltage Vcc is applied between electrodes 14 and 17, creating a potential gradient in the X direction of the transparent conductive film 51. At this time, the voltage of the pressed point is input to ADC4 via electrode 32. Also, when processor 3 detects the Y-coordinate of the pressed point within the rectangular region 12a, it turns on switches 41 and 42 and turns off switches 21 and 23. As a result, the power supply voltage Vcc is applied between electrodes 31 and 32, creating a potential gradient in the Y direction of the transparent conductive film 52. At this time, the voltage of the pressed point is input to ADC4 via electrode 14.

[0025] The ADC4 converts the potential of the input press point into a digital value and outputs it to the processor 3. The processor 3 detects the X and Y coordinates of the press point within the rectangular area 12a based on the digital value from the ADC4. The processor 3 alternates between detecting the X coordinate of the press point and detecting the Y coordinate of the press point.

[0026] Furthermore, when the processor 3 detects the Y coordinate of the pressed point within the first button area 11, it turns on switches 41 and 42 and turns off switch 22. As a result, the power supply voltage Vcc is applied between electrodes 31 and 32, creating a potential gradient in the Y direction of the transparent conductive film 52. At this time, the voltage of the pressed point is input to the ADC 4 via electrode 15.

[0027] The ADC4 converts the potential at the point of impact into a digital value, and the processor 3 detects which button was pressed based on the digital value from the ADC4 and information indicating the correspondence between the digital value and buttons 11a and 11b. The information indicating the correspondence between the digital value from the ADC4 and buttons 11a and 11b is pre-stored in the ROM 5.

[0028] Furthermore, when the processor 3 detects the Y coordinate of the pressed point within the second button area 13, it turns on switches 41 and 42 and turns off switch 24. As a result, the power supply voltage Vcc is applied between electrodes 31 and 32, creating a potential gradient in the Y direction of the transparent conductive film 52. At this time, the voltage of the pressed point is input to the ADC 4 via electrode 18.

[0029] The ADC4 converts the potential at the point of impact into a digital value, and the processor 3 detects which button was pressed based on the digital value from the ADC4 and information indicating the correspondence between the digital value and buttons 13a and 13b. The information indicating the correspondence between the digital value from the ADC4 and buttons 13a and 13b is pre-stored in the ROM 5.

[0030] Therefore, by keeping switches 41 and 42 ON and sequentially turning off switches 22, 21 and 23, and 24, the processor 3 can sequentially detect the Y coordinate of the pressed point in the first button area 11, the Y coordinate of the pressed point in the rectangular area 12a, and the Y coordinate of the pressed point in the second button area 13. In other words, the processor 3 can detect which of the first button area 11, the operation area 12, and the second button area 13 has been pressed.

[0031] Figure 4 is a flowchart showing the processes performed by the control device 2.

[0032] First, processor 3 turns on switches 41 and 42 to generate a potential gradient in the Y direction of the transparent conductive film 52 (S1). Processor 3 then turns off switch 22 to determine whether there is a potential input from electrode 15, i.e., whether the first button area 11 has been pressed (S2).

[0033] If the first button area 11 is pressed (YES in S2), the ADC4 converts the potential of the press point into a digital value, and the processor 3 detects which button was pressed based on the digital value from the ADC4 and information indicating the correspondence between the digital value and buttons 11a and 11b (S3), and proceeds to S4.

[0034] If the first button area 11 is not pressed (NO in S2), the processor 3 turns off switches 21 and 23 and determines whether there is a potential input from electrode 14, i.e., whether the operation area 12 is pressed (S4).

[0035] If there is a press in the operating area 12 (YES in S4), ADC4 converts the potential of the press point into a digital value. Processor 3 detects the Y coordinate of the press point based on the digital value from ADC4 (S5). Next, processor 3 turns off switches 41 and 42 and turns on switches 21 and 23. ADC4 converts the potential of the press point into a digital value at this time. Processor 3 detects the X coordinate of the press point based on the digital value from ADC4 (S6) and proceeds to S7.

[0036] If there is no press in the operation area 12 (NO in S4), the processor 3 turns off the switch 24 and determines whether there is a potential input from the electrode 18, that is, whether or not the second button area 13 has been pressed (S7).

[0037] If the second button area 13 is pressed (YES in S7), the ADC4 converts the potential of the press point into a digital value, and the processor 3 detects which button was pressed based on the digital value from the ADC4 and information indicating the correspondence between the digital value and buttons 13a and 13b (S8), and terminates this process. If the second button area 13 is not pressed (NO in S7), this process terminates.

[0038] According to the touch panel 1 in Figures 2(A) and (B), a pair of electrodes 14 and 17 are provided so as to sandwich the rectangular area 12a of the operation area 12 in the X direction, and electrodes 15 and 18 for detecting pressed buttons are separately provided in the first button area 11 and the second button area 13. Compared to the case where electrodes are arranged at both ends in the X direction of the upper substrate, the potential applied to both ends of the operation area 12 is increased, and thus the resolution in the operation area 12 can be improved.

[0039] (First variation) The first modified example of the first embodiment will be described below. Note that the first modified example differs from the first embodiment in the structure of the touch panel, but the other configurations are the same as those of the first embodiment.

[0040] Figure 5(A) shows the configuration of the upper circuit board of the touch panel 1A, and Figure 5(B) shows the configuration of the lower circuit board of the touch panel 1A. The upper circuit board 10 and the lower circuit board 30 of the touch panel 1A are convex in shape. The first button area 11 and the second button area 13 have been modified to a notched shape. Thus, the width in the Y direction of the first button area 11 and the second button area 13 is shorter than the width in the Y direction of the operation area 12.

[0041] According to the first modified example, even in a non-rectangular, irregularly shaped touch panel, a pair of electrodes 14 and 17 are provided so as to sandwich the rectangular area 12a of the operation area 12 in the X direction, and electrodes 15 and 18 for detecting pressed buttons are separately provided in the first button area 11 and the second button area 13. Therefore, compared to the case where electrodes are arranged at both ends of the upper substrate in the X direction, the resolution corresponding to the operation area 12 can be improved.

[0042] (Second variation) The following describes a second modification of the first embodiment. The second modification differs from the first modification in the structure of the touch panel, but the other configurations are the same as those of the first modification.

[0043] Figure 6(A) shows the configuration of the upper substrate of the touch panel 1B, and Figure 6(B) shows the configuration of the lower substrate of the touch panel 1B. On the lower substrate 30, an etching pattern 33 (second etching pattern) is formed on the transparent conductive film 52 between the buttons 11a and 11b and the rectangular region 12a, and an etching pattern 34 (second etching pattern) is formed on the transparent conductive film 52 between the buttons 13a and 13b and the rectangular region 12a. The etching patterns 33 and 34 make the transparent conductive film 52 in the operating region 12 substantially rectangular, which suppresses the curvature of equipotential lines in the Y direction. The etching patterns 33 and 34 may overlap the lower substrate side of the electrodes 31 and 32.

[0044] According to the second modification, the same effects as those of the first modification can be obtained. Furthermore, since the curvature of equipotential lines in the Y direction can be suppressed, uniformity of the potential distribution in the Y direction in the first button area 11, the second button area 13, and the operating area 12 can be ensured, thereby improving position detection accuracy.

[0045] (Third variation) The third modified example of the first embodiment will be described below. Note that the third modified example differs from the second modified example in the structure of the touch panel, but the other configurations are the same as those of the second modified example.

[0046] Figure 7(A) shows the configuration of the upper circuit board of the touch panel 1C, and Figure 7(B) shows the configuration of the lower circuit board of the touch panel 1C.

[0047] As shown in Figures 7(A) and (B), the second button area 13 has a plurality of buttons 13a-13d arranged in two rows and two columns. Therefore, the processor 3 needs to detect the XY coordinates in order to detect which button in the second button area 13 is pressed. For this purpose, a pair of electrodes 18a and 20 (fourth electrodes) are provided in the second button area 13 so as to sandwich the plurality of buttons 13a-13d in the X direction. Electrode 20 extends in the Y direction between the etching pattern 19 and the buttons 13a and 13b.

[0048] Furthermore, in order to ensure uniformity of the potential distribution in the X direction in the second button region 13, the slit 26 is formed parallel to the portion of the electrode 18a that extends in the X direction. The slit is provided to make the potential distribution in the button region uniform.

[0049] Switch 25 is composed of, for example, a transistor. The base of switch 25 is connected to processor 3 and is controlled on / off by processor 3. The power supply voltage Vcc is applied to the emitter of switch 25, and electrode 18a is connected to the collector of switch 25.

[0050] When processor 3 detects the X-coordinate of the pressed point in the second button area 13, it turns on switches 24 and 25 and turns off switches 41 and 42. This applies the power supply voltage Vcc between electrodes 18a and 20, creating a potential gradient in the X direction of the transparent conductive film 51. At this time, the voltage of the pressed point is input to ADC 4 via the transparent conductive film 52. Similarly, when processor 3 detects the Y-coordinate of the pressed point in the second button area 13, it turns on switches 41 and 42 and turns off switches 24 and 25. This applies the power supply voltage Vcc between electrodes 31 and 32, creating a potential gradient in the Y direction of the transparent conductive film 52. At this time, the voltage of the pressed point is input to ADC 4 via the transparent conductive film 51.

[0051] The ADC4 converts the potential at the point of impact into a digital value, and the processor 3 detects which button was pressed based on the digital value from the ADC4 and information indicating the correspondence between the digital value and buttons 13a-13d. The information indicating the correspondence between the digital value from the ADC4 and buttons 13a-13d is pre-stored in the ROM 5.

[0052] In the third modified example, the processor 3 can, while keeping switches 41 and 42 on, sequentially turn off switches 22, 21 and 23, and 24 and 25 to detect which of the first button area 11, the operation area 12, and the second button area 13 has been pressed, and sequentially detect the Y coordinate of the pressed point in the first button area 11, the Y coordinate of the pressed point in the rectangular area 12a, and the Y coordinate of the pressed point in the second button area 13.

[0053] Figure 8 is a flowchart showing the processes executed by the control device 2. Processes identical to those in Figure 4 are denoted by the same reference numerals as in Figure 4, and their descriptions are omitted.

[0054] First, the processes S1-S6 are executed, as in Figure 4. Then, if there is no press in the operation area 12 (NO in S4), the processor 3 turns on switches 41 and 42, turns off switches 24 and 25, and determines whether there is a potential input from electrode 20, that is, whether the second button area 13 has been pressed (S7).

[0055] If the second button area 13 is pressed (YES in S7), the ADC4 converts the potential of the pressed point corresponding to the Y coordinate of the pressed point into a digital value and outputs it to the processor 3 (S9). Furthermore, the processor 3 turns off switches 41 and 42 and turns on switches 24 and 25, and the ADC4 converts the potential of the pressed point corresponding to the X coordinate of the pressed point into a digital value and outputs it to the processor 3 (S10). After that, the processor 3 detects which button was pressed based on the digital value from the ADC4 (digital values ​​in S9 and S10) and information indicating the correspondence between the digital value and buttons 13a-13d (S11), and terminates this process.

[0056] According to the third modification, the same effects as those of the first and second modifications can be obtained. Furthermore, even when the second button area 13 has multiple buttons 13a-13d arranged in multiple rows and multiple columns, the pressed button can be detected with high accuracy.

[0057] Alternatively, instead of the second button area 13, the first button area 11 may be provided with multiple buttons arranged in multiple rows and multiple columns, or both the first button area 11 and the second button area 13 may be provided with multiple buttons arranged in multiple rows and multiple columns.

[0058] (Second Embodiment) The second embodiment will now be described. The second embodiment differs from the first embodiment and the first to third modified examples in the structure of the touch panel, but the other configurations are the same as those of the first embodiment.

[0059] Figure 9(A) shows the configuration of the upper circuit board of the touch panel 1D, and Figure 9(B) shows the configuration of the lower circuit board of the touch panel 1D.

[0060] As shown in Figures 9(A) and (B), the first button area 11 has a plurality of buttons 11a-11d arranged in two rows and two columns, and the second button area 13 has a plurality of buttons 13a-13d arranged in two rows and two columns.

[0061] The processor 3 needs to detect the XY coordinates in order to detect which button is pressed in the first button area 11 and the second button area 13. For this purpose, a pair of electrodes 14 and 15 are provided in the first button area 11 so as to sandwich a plurality of buttons 11a-11d in the X direction, and a pair of electrodes 17 and 18 are provided in the second button area 13 so as to sandwich a plurality of buttons 13a-13d in the X direction.

[0062] Electrodes 14 and 17 are positioned so as to sandwich the rectangular area 12a of the operating area 12 in the X direction. In other words, electrode 14 is shared for detecting coordinates within the rectangular area 12a and the coordinates of the first button area 11, and electrode 17 is shared for detecting coordinates within the rectangular area 12a and the coordinates of the second button area 13. Therefore, as shown in Figure 7(a), it is not necessary to provide a pair of electrodes for each area, and the number of electrodes can be reduced, thereby reducing manufacturing costs.

[0063] Switches 21-24, 25, and 27 are composed of transistors, for example. The bases of switches 21-24, 25, and 27 are connected to processor 3 and are controlled on / off by processor 3. The power supply voltage Vcc is applied to the emitters of switches 21, 25, and 27, and electrodes 17, 18, and 14 are connected to the collectors of switches 21, 25, and 27, respectively. Electrodes 15, 14, and 18 are connected to the emitters of switches 22-24, respectively. An ADC4 is connected to the emitter of switch 22-24, and the collector of switch 22-24 is grounded.

[0064] Furthermore, no etching pattern is formed at the boundary between the first button area 11 and the operation area 12, nor at the boundary between the second button area 13 and the operation area 12. Therefore, the processor 3 can turn on switches 25 and 22, apply a voltage in the X direction between electrodes 15 and 18, and then turn off the other switches 21, 23, 24, 27, 41, and 42, thereby using electrodes 32 to detect which of the first button area 11, operation area 12, and second button area 13 has been pressed.

[0065] However, by applying a voltage in the X direction between electrode 15 and electrode 18, the coordinates of the pressed point in the X direction can be obtained for the entire touch panel 1D, including the first button area 11, the operation area 12, and the second button area 13, but the resolution is distributed across each area. In the example in Figure 9, since the dimensions in the X direction of each area are almost the same, the resolution per area is about 1 / 3, and the accuracy of coordinate detection decreases. Therefore, in the second embodiment, the processor 3 switches the switch so that all the voltage is applied only to the area to which the X coordinate obtained from the entire touch panel 1D belongs, and measures the X coordinate of the pressed point again, thereby detecting the X coordinate within that area with 100% resolution. In addition, since the measurement is performed only on the area where input is detected, the measurement time can be shortened compared to measuring each area individually.

[0066] In this embodiment, electrodes 14, 18 or electrodes 15, 17 correspond to a pair of second electrodes formed to sandwich the operating area and the button area in the X direction. Electrode 17 corresponds to a third electrode formed to sandwich multiple buttons in the X direction between the electrode (electrode 18) of the pair of second electrodes (electrodes 14, 18) that is closer to the button area. Also, electrode 14 corresponds to a third electrode formed to sandwich multiple buttons in the X direction between the electrode (electrode 15) of the pair of second electrodes (electrodes 15, 17) that is closer to the button area.

[0067] Figure 10 is a flowchart showing the process performed by the control device 2 according to the second embodiment.

[0068] First, the processor 3 turns on switches 22 and 25 to generate a potential gradient in the X direction of the transparent conductive film 51 (S21). The processor 3 then turns off switches 41 and 42 and detects which of the first button area 11, the operation area 12, and the second button area 13 has been pressed based on the potential input from the electrode 32 (S22). More specifically, the ADC 4 converts the potential of the pressed point corresponding to the X coordinate of the pressed point into a digital value and outputs it to the processor 3. Subsequently, the processor 3 detects which of the first button area 11, the operation area 12, and the second button area 13 has been pressed based on the digital value from the ADC 4 and information showing the correspondence between the digital value and the first button area 11, the operation area 12, and the second button area 13. The information showing the correspondence between the digital value from the ADC 4 and the first button area 11, the operation area 12, and the second button area 13 is stored in the ROM 5 in advance.

[0069] If the first button area 11 is pressed in S22, the processor 3 turns off switches 41 and 42 and turns on switches 27 and 22 to generate a potential gradient in the X direction between electrodes 14 and 15 (S23). The ADC 4 converts the potential of the pressed point corresponding to the X coordinate of the pressed point into a digital value and outputs it to the processor 3 (S24). Next, the processor 3 turns on switches 41 and 42 and turns off switches 27 and 22 to generate a potential gradient in the Y direction between electrodes 31 and 32 (S25). The ADC 4 converts the potential of the pressed point corresponding to the Y coordinate of the pressed point into a digital value and outputs it to the processor 3 (S26). After that, the processor 3 detects which button was pressed based on the digital value from the ADC 4 (digital values ​​from S24 and S26) and information indicating the correspondence between the digital value and buttons 11a-11d (S27), and terminates this process.

[0070] If a press occurs in the operating area 12 in S22, the processor 3 turns off switches 41 and 42 and turns on switches 21 and 23 to generate a potential gradient in the X direction between electrodes 14 and 17 (S28). The ADC 4 converts the potential at the press point into a digital value, and the processor 3 detects the X coordinate of the press point based on the digital value from the ADC 4 (S29). Furthermore, the processor 3 turns on switches 41 and 42 and turns off switches 21 and 23 to generate a potential gradient in the Y direction between electrodes 31 and 32 (S30). The ADC 4 converts the potential at the press point into a digital value, and the processor 3 detects the Y coordinate of the press point based on the digital value from the ADC 4 (S31), and this process ends.

[0071] If the second button area 13 is pressed in S22, the processor 3 turns off switches 41 and 42 and turns on switches 24 and 25 to generate a potential gradient in the X direction between electrodes 14 and 15 (S32). The ADC 4 converts the potential of the pressed point corresponding to the X coordinate of the pressed point into a digital value and outputs it to the processor 3 (S33). Next, the processor 3 turns on switches 41 and 42 and turns off switches 24 and 25 to generate a potential gradient in the Y direction between electrodes 31 and 32 (S34). The ADC 4 converts the potential of the pressed point corresponding to the Y coordinate of the pressed point into a digital value and outputs it to the processor 3 (S35). After that, the processor 3 detects which button was pressed based on the digital value from the ADC 4 (digital values ​​from S33 and S35) and information indicating the correspondence between the digital value and buttons 13a-13d (S36), and terminates this process.

[0072] As described above, according to the second embodiment, by applying a voltage in the X direction between electrode 15 and electrode 18, it is possible to detect which of the first button area 11, operation area 12, and second button area 13 has been pressed. Then, the switch is turned so that all the voltage is applied only to the pressed area, improving the resolution and measuring the X coordinate of the pressed point again. Therefore, even when the first button area 11 and second button area 13 are adjacent to the operation area 12, precise position detection can be performed. In addition, since the measurement is performed only on the area where input is detected, the measurement time can be shortened.

[0073] In the first embodiment, the first to fourth modifications of the first embodiment, and the second embodiment, each touch panel has two button areas, a first button area 11 and a second button area 13, but the number of button areas may be one or three or more. Also, the first button area 11, the operation area 12, and the second button area 13 are arranged in a single row in the X direction, but they may also be arranged in a single row in the Y direction.

[0074] Furthermore, the present invention is not limited to the embodiments described above, and can be implemented in various modified forms without departing from its essence. [Explanation of Symbols]

[0075] 1. 1A-1D Touch Panel 10 Upper circuit board 11. First button area 11a-11d, 13a-13d buttons 12 Operation area 13. Second button area 14 electrode (second electrode) 15 electrode (3rd electrode) 16, 19 Etching patterns (First etching pattern) 17 electrode (second electrode) 18 electrodes (3rd electrode) 18a Electrode (4th electrode) 20 electrodes (4th electrode) 30 Lower circuit board 31 electrode (1st electrode) 32 electrodes (1st electrode) 33, 34 Etching patterns (2nd etching pattern)

Claims

1. A first substrate having a first conductive film, The device comprises a second substrate having a second conductive film disposed opposite to the first conductive film, The first substrate and the second substrate each have an operating area and a button area adjacent to the operating area in a first direction, provided on the first conductive film and the second conductive film, The aforementioned button area includes multiple buttons, The second substrate has a pair of first electrodes that apply a voltage in a second direction intersecting the first direction, The first substrate is a touch panel characterized by having a pair of second electrodes arranged along the outer circumference of the operating area to which a voltage is applied in a first direction, a first etching pattern formed on the first conductive film between the electrode of the pair of second electrodes that is closer to the button area and the button area, and a third electrode formed in common for the plurality of buttons in the button area.

2. The touch panel according to claim 1, characterized in that the second conductive film comprises a second etching pattern extending in the second direction between the operating area and the button area.

3. The first substrate is provided with a pair of fourth electrodes that extend in the second direction and sandwich the button region in the first direction, The touch panel according to claim 1 or 2, characterized in that the plurality of buttons are arranged in multiple rows in the first direction and the second direction.

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