Electrostatic capacitance detection device

Abstract

An electrostatic capacitance detection device detects an electrostatic capacitance between an object approaching a detection electrode and the detection electrode, the electrostatic capacitance detection device including: the detection electrode that detects the electrostatic capacitance with the object; an active shield electrode that is disposed close to the detection electrode; a voltage output circuit that outputs an alternating voltage supplied to the active shield electrode; a first adjustment circuit that adjusts an amplitude of the alternating voltage output by the voltage output circuit; and a first operational amplifier that amplifies and outputs a voltage difference between an inverting input terminal connected to one end of the detection electrode and a voltage of a non-inverting input terminal to which the alternating voltage adjusted by the first adjustment circuit is applied, the detection electrode having a resistance value of 5 kΩ or more and 270 kΩ or less between the one end and the other end.

Description

Technical Field

[0001] The present invention relates to an electrostatic capacitance detection device. Background Art

[0002] The following patent document 1 discloses the following technology: a wiring substrate has a plurality of electrode portions, a plurality of terminal portions, and terminal wiring portions respectively connected to each other in a conductive portion arranged on the surface of an insulating substrate. In this wiring substrate, noise current is prevented from flowing into a control circuit by setting conditions for the line width and resistance value of the terminal wiring portion.

[0003] In addition, the following patent document 2 discloses the following technology: a first sensor group and a second sensor group oriented in mutually intersecting directions are provided on each surface of a substrate, and in a touch sensor panel in which a rectangular touch sensor effective area is formed by the first sensor group and the second sensor group, by determining the conditions for determining the sensor length, a reduction in touch sensitivity associated with the elongation of the touch sensor effective area can be prevented, and an area that does not contribute to touch detection can be avoided from being interposed therebetween.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: International Publication No. 2015 / 005319

[0007] Patent Document 2: International Publication No. 2019 / 064595 Summary of the Invention

[0008] -Problems to be solved by the invention-

[0009] However, in existing electrostatic capacitance detection devices that utilize the mutual capacitance method, the lower the resistance value of the detection electrode, the less the detection value of the electrostatic capacitance decreases. Therefore, generally speaking, although a detection electrode with suppressed resistance value is preferred, there is no clear specification for the resistance value of the detection electrode, and the specification needs to be determined each time a simulation is performed.

[0010] On the other hand, the electrostatic capacitance detection device using the absolute self-capacitance method uses the fact that the electrostatic capacitance of the detection electrode changes according to the resistance value of the detection electrode. Therefore, there are limitations in the range of the resistance value of the detection electrode and the electrostatic capacitance between the detection electrode and the active shielding electrode. When exceeding this range, there is a problem that the detection performance cannot be fully exerted.

[0011] -Methods for solving the problem-

[0012] An electrostatic capacitance detection device according to one embodiment detects electrostatic capacitance between an object and an electrostatic capacitance detection device, the electrostatic capacitance detection device comprising: a detection electrode that detects electrostatic capacitance between the object and an active shielding electrode; an active shielding electrode that is arranged in proximity to the detection electrode; a voltage output circuit that outputs an AC voltage supplied to the active shielding electrode; a first adjustment circuit that adjusts the amplitude of the AC voltage output by the voltage output circuit; and a first operational amplifier that amplifies and outputs a voltage difference between an inverting input terminal connected to one end of the detection electrode and a non-inverting input terminal to which an AC voltage adjusted by the first adjustment circuit is applied, wherein the detection electrode has a resistance value between one end and the other end of the detection electrode of not less than 5 kΩ and not more than 270 kΩ.

[0013] -Effects of the Invention-

[0014] According to one embodiment, in a capacitance detection device capable of detecting the approaching position of an object based on a change in capacitance value in a detection electrode having a resistance gradient, good capacitance value detection can be performed according to the operating range of the detection circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a diagram showing an example of the configuration of an electrostatic capacitance detection device according to an embodiment.

[0016] Figure 2 This is a diagram showing an example of a stacked structure of an electrostatic capacitance detection unit included in an electrostatic capacitance detection device according to an embodiment.

[0017] Figure 3 This is a diagram showing an example of changes in capacitance values ​​detected by the first AFE block and the second AFE block according to one embodiment.

[0018] Figure 4 This is a diagram showing an example of changes in output voltage values ​​in the first AFE block and the second AFE block according to one embodiment.

[0019] Figure 5 This is a diagram showing simulation results in which the voltage range of the offset voltage is 2 V or less in the electrostatic capacitance detection unit according to one embodiment.

[0020] Figure 6 This is a diagram showing the structure of a slider which is a first application example of the electrostatic capacitance detection device according to one embodiment.

[0021] Figure 7 This is a diagram showing the structure of a touch panel which is a second application example of the electrostatic capacitance detection device according to one embodiment. DETAILED DESCRIPTION

[0022] Hereinafter, one embodiment will be described with reference to the drawings.

[0023] (Example of the Configuration of the Electrostatic Capacitance Detection Device 100)

[0024] Figure 1 1 is a diagram showing an example of the configuration of an electrostatic capacitance detection device 100 according to an embodiment. Figure 1 The illustrated capacitance detection device 100 is, for example, a touch panel that utilizes self-capacitance capacitance detection, and detects capacitance between the touch panel and the object 10. Specifically, the capacitance detection device 100 can detect the proximity of the object 10 (e.g., an operator's finger) to the detection electrode 111 through self-capacitance capacitance detection.

[0025] like Figure 1 As shown, the capacitance detection device 100 includes a capacitance detection unit 110 , a first AFE (Analog Front End) block 120 , a second AFE block 130 , a first voltage output circuit 141 , and a second voltage output circuit 142 .

[0026] The electrostatic capacitance detection unit 110 has a detection electrode 111 and an active shielding electrode 112. The detection electrode 111 is a thin plate-shaped and strip-shaped (longitudinally long) component formed using a conductive material. The detection electrode 111 detects the electrostatic capacitance between the detection electrode 111 and the object 10. Specifically, the electrostatic capacitance between the detection electrode 111 and the object 10 changes as the object 10 approaches. In the present embodiment, the detection electrode 111 includes resistive ITO (Indium Tin Oxide). Thus, the detection electrode 111 has a resistance inclination between one end in the long side direction and the other end. In addition, in the present embodiment, the detection electrode 111 has a resistance value of greater than 5 kΩ and less than 270 kΩ between one end and the other end.

[0027] The active shielding electrode 112 is a thin plate-shaped and strip-shaped component formed using a conductive material. The active shielding electrode 112 is arranged close to the detection electrode 111. In this embodiment, the active shielding electrode 112 is arranged to overlap the back side of the detection electrode 111. The active shielding electrode 112 is driven to the same potential as the detection electrode 111 by supplying an AC voltage from the first voltage output circuit 141 and the second voltage output circuit 142. In addition, the active shielding electrode 112 is configured so that the electrostatic capacitance Crs between it and the detection electrode 111 is greater than 30pF and less than 130pF. In addition, in Figure 1, the first voltage output circuit 141 and the second voltage output circuit 142 are described as separate voltage output circuits, but a single voltage output circuit may be used for the first voltage output circuit 141 and the second voltage output circuit 142 .

[0028] The first AFE block 120 is connected to one end of the electrostatic capacitance detection unit 110. The first AFE block 120 detects the electrostatic capacitance between the detection electrode 111 and the object 10 from one end side of the electrostatic capacitance detection unit 110. The first AFE block 120 has an ATT 121 and a first operational amplifier 122. The ATT 121 is an example of a "first adjustment circuit" that adjusts the amplitude of the AC voltage output by the first voltage output circuit 141. In other words, the ATT 121 adjusts the amplitude of the AC voltage output from the first voltage output circuit 141 and supplied to one end of the active shielding electrode 112. The first operational amplifier 122 amplifies the voltage difference between the inverting input terminal (-) connected to one end of the detection electrode 111 and the non-inverting input terminal (+) to which the AC voltage adjusted by the ATT 121 is applied, and outputs it as an output signal AFEOUT1 to a higher-level controller (not shown).

[0029] The second AFE block 130 is connected to the other end of the electrostatic capacitance detection unit 110. The second AFE block 130 detects the electrostatic capacitance between the detection electrode 111 and the object 10 from the other end side of the electrostatic capacitance detection unit 110. The second AFE block 130 has an ATT 131 and a second operational amplifier 132. The ATT 131 is an example of a "second adjustment circuit" that adjusts the amplitude of the AC voltage output by the second voltage output circuit 142. In other words, the ATT 131 adjusts the amplitude of the AC voltage output from the second voltage output circuit 142 and supplied to the other end of the active shielding electrode 112. In addition, when the first voltage output circuit 141 and the second voltage output circuit 142 are composed of the same (single) voltage output circuit, it can be said that the ATT 131 adjusts the amplitude of the AC voltage output by the first voltage output circuit 141. The second operational amplifier 132 amplifies the voltage difference between the inverting input terminal (-) connected to the other end of the detection electrode 111 and the non-inverting input terminal (+) to which the AC voltage adjusted by the ATT131 is applied, and outputs it to the upper controller as an output signal AFEOUT2.

[0030] (Example of a Laminated Structure of the Capacitance Detection Unit 110)

[0031] Figure 2 This is a diagram showing an example of a stacked structure of the capacitance detection unit 110 included in the capacitance detection device 100 according to one embodiment.

[0032] like Figure 2As shown in FIG. 1 , the electrostatic capacitance detection unit 110 has a stacked structure in which a plurality of thin plate-shaped members are stacked. Figure 2 In the example shown, the electrostatic capacitance detection unit 110 has, from the surface side (upper side in the figure), a panel 113, an OCA (Optical Clear Adhesive) 114, a detection electrode 111, a PET (Polyethylene Terephthalate) 115, an OCA 116, an active shielding electrode 112 and a PET 117.

[0033] The surface of the panel 113 is provided on the outermost surface of the capacitance detection unit 110. The surface of the panel 113 serves as a detection surface 113A for performing an approach operation of an object.

[0034] PET 115 is provided on the back side of panel 113. PET 115 is a thin film-shaped flexible substrate. Detection electrodes 111 are formed on the surface of PET 115. The surface of PET 115 is bonded to the back side of panel 113 via OCA 114. OCA 114 is a thin film-shaped adhesive sheet.

[0035] PET 117 is provided on the back side of PET 115. PET 117 is a thin film-like flexible substrate. Active shield electrode 112 is formed on the surface of PET 117. The surface of PET 117 is bonded to the back side of PET 115 via OCA 116, a thin film-like adhesive sheet.

[0036] (Example of Change in Electrostatic Capacitance Value)

[0037] Figure 3 This is a diagram showing an example of changes in capacitance values ​​detected by the first AFE block 120 and the second AFE block 130 according to one embodiment. As already described, the detection electrode 111 has a resistance gradient between one end and the other end.

[0038] Therefore, as the object 10 approaches the detection electrode 111, the object 10 moves closer to one end of the detection electrode 111 ( Figure 3 As shown in FIG. 1B , the resistance value between one end of the detection electrode 111 and the object 10 gradually decreases, that is, the electrostatic capacitance value ( Figure 3 The solid line in the figure) gradually increases.

[0039] On the contrary, as the approach position of the object 10 in the detection electrode 111 approaches one end ( Figure 3 B), the other end of the detection electrode 111 ( Figure 3The resistance value between the electrode 111 and the object 10 gradually increases, that is, the capacitance value ( Figure 3 The dotted line in the figure) gradually decreases.

[0040] Therefore, the upper controller can determine the proximity position of the object 10 in the detection electrode 111 based on the ratio of the electrostatic capacitance value detected by the first AFE block 120 and the electrostatic capacitance value detected by the second AFE block 130 .

[0041] (Example of Change in Output Voltage Value)

[0042] Figure 4 This is a diagram showing an example of changes in output voltage values ​​of the first AFE block 120 and the second AFE block 130 according to one embodiment.

[0043] In this embodiment, the voltage supplied to the first AFE block 120 and the second AFE block 130 is 5V, which is the minimum voltage capable of hover detection. Figure 4 In the illustrated example, 0-4 V is used as the operating range of the output voltage values ​​of the first AFE block 120 and the second AFE block 130 .

[0044] The voltage range of the offset voltage generated according to the parasitic capacitance of the detection electrode 111 is 0-2 V. The voltage range of the detection region in which the voltage value changes linearly according to the detection position of the object 10 is 2-4 V.

[0045] Specifically, in order to satisfactorily detect the position of the object 10, including hovering operations, using the output voltage values ​​of the first AFE block 120 and the second AFE block 130 according to one embodiment, a voltage range of 2 V is required as the detection area. To achieve this, the offset voltage range must be suppressed to 2 V or less.

[0046] (Suitable Ranges of Resistance Rp and Capacitance Crs)

[0047] Figure 5 The electrostatic capacitance detection unit 110 (having Figure 2 Graph showing simulation results for a region where the offset voltage range is 2 V or less (a range of resistance values ​​and a range of electrostatic capacitance values) in the stacked structure shown in FIG.

[0048] exist Figure 5 In the graph shown, the vertical axis represents the resistance value Rp from one end to the other end of the detection electrode 111. Figure 5In the graph shown, the horizontal axis represents the electrostatic capacitance Crs between the detection electrode 111 and the active shield electrode 112 .

[0049] according to Figure 5 The simulation results shown in FIG. 4 show that the first AFE block 120 and the second AFE block 130 according to one embodiment can reduce the offset voltage range to 2 V or less by setting the resistance value Rp from one end to the other of the detection electrode 111 to 5 kΩ or more and 270 kΩ or less, and by setting the capacitance Crs between the detection electrode 111 and the active shield electrode 112 to 30 pF or more and 130 pF or less. Consequently, the capacitance detection device 100 according to one embodiment can successfully detect the position of the object 10, including hovering operations, based on the output voltage values ​​of the first AFE block 120 and the second AFE block 130.

[0050] In actual products, the resistance value Rp and the capacitance Crs are adjusted to fall within the above-mentioned appropriate ranges by adjusting the size of the detection electrode 111 , the gap between the detection electrode 111 and the active shield electrode 112 , and the like.

[0051] Here, a case where the resistance value Rp and the capacitance Crs are outside the above-described appropriate ranges will be described.

[0052] For example, if the resistance value Rp is less than 5 kΩ, the offset voltage will no longer converge to 2 V, and the sensor's detection range may be reduced. Furthermore, if the resistance value Rp is less than 5 kΩ, the change in capacitance caused by a change in the proximity of the object 10 is too small, and the proximity of the object 10 may no longer be accurately detected from the capacitance.

[0053] Furthermore, when the resistance value Rp is 270 kΩ or greater, the offset voltage no longer converges to 2 V, potentially reducing the sensor's detection range. Furthermore, when the resistance value Rp is 270 kΩ or greater, the resistance is too high, and the change in capacitance is no longer linear, making it impossible to accurately detect the approaching position of the object 10 based on the capacitance value. Furthermore, when the resistance value Rp is 270 kΩ or greater, the high impedance of the detection electrode 111 may degrade the SN ratio.

[0054] Furthermore, if the capacitance Crs is less than 30 pF, the offset voltage no longer converges to 2 V, potentially reducing the sensor's detection range. To expand this range, the value of the level shift capacitor for the active shield electrode 112 within the IC must be increased, potentially constraining IC design.

[0055] Furthermore, if the capacitance Crs exceeds 130pF, the offset voltage will no longer converge to 2V, potentially reducing the sensor's detection range. In this case, while reducing the value of the internal adjustment capacitor does not pose a design constraint, the phase lag caused by the capacitance may prevent the offset from being completely eliminated. While this can be improved by adding a phase adjustment circuit, this may increase circuit size.

[0056] (First Application Example of the Capacitance Detection Device 100)

[0057] Figure 6 FIG. 1 is a diagram showing the structure of a slider 20 as a first application example of the electrostatic capacitance detection device 100 according to one embodiment. Figure 6 As shown, the slider 20 includes: a detection electrode 111A extending linearly in the horizontal direction; and an active shield electrode 112A provided on the back side of the detection electrode 111. The detection electrode 111A has one end and the other end connected to the control circuit 22 via a connection line 118. In addition, the active shield electrode 112A is connected to the control circuit 22 via the connection line 118. The control circuit 22 is provided with a first AFE block 120, a second AFE block 130, a first voltage output circuit 141, and a second voltage output circuit 142 (all refer to FIG. Figure 1 ) etc. For example, the detection electrode 111A has Figure 2 The cross-sectional structure of the detection electrode 111 shown is the same as the cross-sectional structure.

[0058] In the slider 20 thus configured, the capacitance value of the detection electrode 111A changes in response to the proximity of the object 10 to the detection electrode 111A. This causes the output voltage values ​​of the first AFE block 120 and the output voltage values ​​of the second AFE block 130 to change in the control circuit 22. The control circuit 22 can detect the proximity of the object 10 to the detection electrode 111A based on the ratio of the output voltage values ​​of the first AFE block 120 to the output voltage values ​​of the second AFE block 130.

[0059] In particular, in the slider 20 , the resistance value Rp from one end to the other end of the detection electrode 111A is 5 kΩ to 270 kΩ, and the capacitance Crs between the detection electrode 111A and the active shield electrode 112 is 30 pF to 130 pF.

[0060] Thus, the control circuit 22 can accurately detect the proximity position of the object 10 from one end of the detection electrode 111A based on the output voltage value of the first AFE block 120, and can accurately detect the proximity position of the object 10 from the other end of the detection electrode 111A based on the output voltage value of the second AFE block 130. Therefore, the control circuit 22 can accurately detect the proximity position of the object 10 relative to the detection electrode 111A based on the ratio of the output voltage value of the first AFE block 120 to the output voltage value of the second AFE block 130.

[0061] (Second Application Example of the Capacitance Detection Device 100)

[0062] Figure 7 FIG. 1 is a diagram showing the structure of a touch panel 30 as a second application example of the electrostatic capacitance detection device 100 according to one embodiment. Figure 7 As shown, the touch panel 30 includes a plurality of first detection electrodes 111X and a plurality of second detection electrodes 111Y.

[0063] The plurality of first detection electrodes 111X are all detection electrodes 111 that extend linearly in the horizontal direction (X-axis direction, an example of the “first direction”). The plurality of first detection electrodes 111X have a fixed interval and are arranged side by side in parallel with each other in the vertical direction (Y-axis direction). The plurality of first detection electrodes 111X are arranged orthogonally to the plurality of second detection electrodes 111Y. The plurality of first detection electrodes 111X each have one end and the other end connected to the control circuit 32 via a connecting line 118. In the control circuit 32, a first AFE block 120, a second AFE block 130, a first voltage output circuit 141, and a second voltage output circuit 142 (all refer to Figure 1 ) etc. For example, the plurality of first detection electrodes 111X each have Figure 2 The cross-sectional structure of the detection electrode 111 shown in FIG. Figure 7 In the illustrated example, the touch panel 30 includes four first detection electrodes 111X, but the number of the first detection electrodes 111X is not limited thereto.

[0064] The plurality of second detection electrodes 111Y are all detection electrodes 111 that extend linearly in the longitudinal direction (the Y-axis direction, an example of the “second direction”). The plurality of second detection electrodes 111Y have a fixed interval and are arranged side by side in parallel with each other in the transverse direction (the X-axis direction). The plurality of second detection electrodes 111Y are arranged orthogonally to the plurality of first detection electrodes 111X. The plurality of second detection electrodes 111Y each have one end and the other end connected to the control circuit 32 via a connecting line 118. In the control circuit 32, a first AFE block 120, a second AFE block 130, a first voltage output circuit 141, and a second voltage output circuit 142 (all refer to Figure 1 ) etc. For example, the plurality of second detection electrodes 111Y each have Figure 2 The cross-sectional structure of the detection electrode 111 shown in FIG. Figure 7 In the illustrated example, the touch panel 30 includes five second detection electrodes 111Y, but the number of the second detection electrodes 111Y is not limited thereto.

[0065] The touch panel 30 configured in this manner changes the capacitance value of each of the plurality of first detection electrodes 111X in response to the proximity position of the object 10 relative to each of the plurality of first detection electrodes 111X (i.e., the proximity position in the lateral direction (X-axis direction)). In this manner, the control circuit 32 changes the output voltage value of the first AFE block 120 connected to one end of each of the plurality of first detection electrodes 111X and the output voltage value of the second AFE block 130 connected to the other end of each of the plurality of first detection electrodes 111X. Consequently, the control circuit 32 can detect the proximity position of the object 10 relative to the touch panel 30 in the lateral direction (X-axis direction) based on the ratio between the output voltage value of the first AFE block 120 and the output voltage value of the second AFE block 130.

[0066] Furthermore, in the touch panel 30 thus configured, the capacitance value of each of the plurality of second detection electrodes 111Y changes in response to the proximity position of the object 10 relative to each of the plurality of second detection electrodes 111Y (i.e., the proximity position in the longitudinal direction (Y-axis direction)). This causes the control circuit 32 to change the output voltage value of the first AFE block 120 connected to one end of each of the plurality of second detection electrodes 111Y and the output voltage value of the second AFE block 130 connected to the other end of each of the plurality of second detection electrodes 111Y. Consequently, the control circuit 32 can detect the proximity position of the object 10 relative to the touch panel 30 in the longitudinal direction (Y-axis direction) based on the ratio between the output voltage value of the first AFE block 120 and the output voltage value of the second AFE block 130.

[0067] In particular, in the touch panel 30 , the resistance value Rp from one end to the other end of each of the plurality of first detection electrodes 111X and the plurality of second detection electrodes 111Y is greater than or equal to 5 kΩ and less than or equal to 270 kΩ, and the electrostatic capacitance Crs between the active shield electrode 112 is greater than or equal to 30 pF and less than or equal to 130 pF.

[0068] Thus, the control circuit 32 can accurately detect the lateral (X-axis direction) proximity position of the object 10 from one end of each of the first detection electrodes 111X based on the output voltage value of the first AFE block 120 connected to each of the first detection electrodes 111X. Furthermore, the control circuit 32 can accurately detect the lateral (X-axis direction) proximity position of the object 10 from the other end of each of the first detection electrodes 111X based on the output voltage value of the second AFE block 130 connected to each of the first detection electrodes 111X. Therefore, the control circuit 32 can accurately detect the lateral (X-axis direction) proximity position of the object 10 relative to the touch panel 30 based on the ratio between the output voltage value of the first AFE block 120 and the output voltage value of the second AFE block 130.

[0069] Furthermore, the control circuit 32 can accurately detect the longitudinal (Y-axis) proximity position of the object 10 from one end of each of the second detection electrodes 111Y based on the output voltage value of the first AFE block 120 connected to each of the second detection electrodes 111Y. Furthermore, the control circuit 32 can accurately detect the longitudinal (Y-axis) proximity position of the object 10 from the other end of each of the second detection electrodes 111Y based on the output voltage value of the second AFE block 130 connected to each of the second detection electrodes 111Y. Therefore, the control circuit 32 can accurately detect the longitudinal (Y-axis) proximity position of the object 10 relative to the touch panel 30 based on the ratio between the output voltage value of the first AFE block 120 and the output voltage value of the second AFE block 130.

[0070] As described above, an electrostatic capacitance detection device 100 according to one embodiment detects the electrostatic capacitance between an object 10 approaching a detection electrode 111 and the detection electrode 111. The electrostatic capacitance detection device 100 includes: a detection electrode 111 that detects the electrostatic capacitance between the object 10 and the detection electrode 111; an active shielding electrode 112 that is arranged close to the detection electrode 111; a first voltage output circuit 141 that outputs an AC voltage supplied to the active shielding electrode 112; an ATT 121 that adjusts the amplitude of the AC voltage output by the first voltage output circuit 141; and a first operational amplifier 122 that amplifies and outputs a voltage difference between an inverting input terminal connected to one end of the detection electrode 111 and a non-inverting input terminal to which the AC voltage adjusted by the ATT 121 is applied. The detection electrode 111 has a resistance value between one end and the other end of the detection electrode 111 of not less than 5 kΩ and not more than 270 kΩ.

[0071] Thus, by defining the resistance value range of the detection electrode 111 as described above, the capacitance detection device 100 according to one embodiment can appropriately obtain a voltage range within the detection region for optimally detecting the position of the object 10, including hovering operations, within the operating range of the first operational amplifier 122. Therefore, the capacitance detection device 100 according to one embodiment can optimally detect the position of the object 10, including hovering operations, based on the output voltage value of the first operational amplifier 122.

[0072] In addition, the electrostatic capacitance detection device 100 involved in one embodiment includes: ATT131, which adjusts the amplitude of the AC voltage output by the second voltage output circuit 142; and a second operational amplifier 132, which amplifies and outputs the voltage difference between the inverting input terminal connected to the other end of the detection electrode 111 and the non-inverting input terminal to which the AC voltage adjusted by ATT131 is applied.

[0073] Thus, the capacitance detection device 100 according to one embodiment can more effectively detect the position of the object 10, including during a hovering operation, based on the output voltage value of the second operational amplifier 132. Therefore, the capacitance detection device 100 according to one embodiment can more accurately detect the position of the object 10 based on the ratio between the output voltage value of the first operational amplifier 122 at one end of the detection electrode 111 and the output voltage value of the second operational amplifier 132 at the other end of the detection electrode 111.

[0074] Furthermore, in the capacitance detection device 100 according to one embodiment, the capacitance between the detection electrode 111 and the active shield electrode 112 is greater than or equal to 30 pF and less than or equal to 130 pF.

[0075] Thus, by defining the capacitance range between the detection electrode 111 and the active shield electrode 112 as described above, the capacitance detection device 100 according to one embodiment can more appropriately obtain a voltage range within the detection region for optimally detecting the position of the object 10, including hovering operations, within the operating range of the first operational amplifier 122 and the second operational amplifier 132. Therefore, the capacitance detection device 100 according to one embodiment can more optimally detect the position of the object 10, including hovering operations, based on the output voltage values ​​of the first operational amplifier 122 and the second operational amplifier 132.

[0076] Furthermore, in the capacitance detection device 100 according to one embodiment, the detection electrode 111 is made of ITO.

[0077] Thus, the capacitance detection device 100 according to one embodiment can provide a resistance gradient in the detection electrode 111 , and thus can satisfactorily detect the position of the object 10 including a hovering operation by utilizing the resistance gradient.

[0078] As mentioned above, although one embodiment of the present invention has been described in detail, the present invention is not limited to these embodiments, and various modifications and changes can be made within the scope of the gist of the present invention described in the claims.

[0079] For example, in the capacitance detection device 100, the detection electrode 111 may be connected to the AFE block at only one end or the other. In this case, the capacitance detection device 100 can also accurately detect the proximity of the object 10 to the detection electrode 111 based on the output voltage value of the AFE block by setting the resistance value Rp and the capacitance Crs within the above-mentioned appropriate ranges.

[0080] This international application claims the benefit of priority based on Japanese Patent Application No. 2020-173382, filed on October 14, 2020, the entire contents of which are incorporated herein by reference.

[0081] -Explanation of symbols-

[0082] 10 Objects

[0083] 20 Slide

[0084] 22 Control Circuit

[0085] 30 Touch Panel

[0086] 32 Control Circuit

[0087] 100 Electrostatic Capacitance Detection Device

[0088] 110 Electrostatic capacitance detection unit

[0089] 111, 111A, 111X, 111Y detection electrodes

[0090] 112, 112A active shield electrode

[0091] 113 Panel

[0092] 114, 116 OCA

[0093] 115, 117 PET

[0094] 118 Wiring

[0095] 120 1st AFE block

[0096] 121 ATT

[0097] 122 No. 1 operational amplifier

[0098] 130 2nd AFE block

[0099] 131 ATT

[0100] 132 Second Operational Amplifier

[0101] 141 1st voltage output circuit

[0102] 142 Second voltage output circuit.

Claims

1. An electrostatic capacitance detection device for detecting electrostatic capacitance between a device and an object, the electrostatic capacitance detection device comprising: a detection electrode for detecting electrostatic capacitance between the electrode and the object; an active shielding electrode disposed proximate to the detection electrode; a voltage output circuit that outputs an AC voltage supplied to the active shielding electrode; a first adjustment circuit for adjusting the amplitude of the AC voltage output by the voltage output circuit; and a first operational amplifier that amplifies and outputs a voltage difference between an inverting input terminal connected to one end of the detection electrode and a non-inverting input terminal to which an AC voltage regulated by the first regulating circuit is applied; The detection electrode has a resistance value between one end and the other end thereof of 5 kΩ or more and 270 kΩ or less, The active shield electrode is arranged so that the electrostatic capacitance between the active shield electrode and the detection electrode is greater than or equal to 30 pF and less than or equal to 130 pF.

2. The electrostatic capacitance detection device according to claim 1, wherein: The electrostatic capacitance detection device comprises: a second adjustment circuit for adjusting the amplitude of the AC voltage output by the voltage output circuit; and The second operational amplifier amplifies and outputs a voltage difference between an inverting input terminal connected to the other end of the detection electrode and a non-inverting input terminal to which the AC voltage regulated by the second regulating circuit is applied.

3. The electrostatic capacitance detection device according to claim 1 or 2, wherein: The detection electrode comprises ITO (indium tin oxide).

4. The electrostatic capacitance detection device according to claim 1 or 2, wherein: The electrostatic capacitance detection device includes a slider composed of a single detection electrode.

5. The electrostatic capacitance detection device according to claim 1 or 2, wherein: The electrostatic capacitance detection device includes a touch panel including a plurality of first detection electrodes extending in a first direction and a plurality of second detection electrodes extending in a second direction orthogonal to the first direction.

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