Input device

Abstract

Provided is an input device capable of accurately detecting a press.　In a proximity detection mode, the input device applies an AC first drive voltage (Vdrv) to one or more drive electrodes (112) by means of a first drive voltage source (141), and applies a DC second drive voltage (Vdc) to a third electrode (130) by means of a second drive voltage source (143), and in a press detection mode, the input device applies an AC second drive voltage (Vdrv) to the third electrode (130) by means of a second drive voltage source (141), and applies an AC first drive voltage (Vcmp) having the same frequency and the opposite phase to the AC second drive voltage to the one or more drive electrodes (112) by means of the first drive voltage source (141, 142), wherein, in the press detection mode, the first drive voltage source (141, 142) is electrically connected to one or more detection electrodes (111) via a capacitance (Ccmp) and / or a resistance (Rcmp) adjusted such that the amplitude of a detection signal is not saturated in an output limit range of a detecting circuit.

Description

Input Devices

[0001] The present disclosure relates to an input device.

[0002] Conventionally, there has been a display device that includes a first electrode section including a plurality of cell electrodes arranged in a matrix, a second electrode section including a base electrode (solid electrode) facing the first electrode section, and a gap section between the first electrode section and the second electrode section that is deformable in the thickness direction. This display device has a pressure detection period and a touch detection period, and during the pressure detection period, a sensor drive signal is applied to the base electrode of the second electrode section, and a pressure is detected based on a change in capacitance value between the first electrode section and the second electrode section. Meanwhile, during the touch detection period, a drive signal is applied to a part of the first electrode section, and a detection signal is detected from another part of the first electrode section, thereby detecting the presence or absence of a touch and the touch position based on the change in capacitance value between the first electrode section and a finger (see, for example, Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2017-167694

[0004] However, if the detection signal representing the capacitance value between the first electrode portion and the second electrode portion is saturated within the output limit range of the detection circuit, there is a risk that the pressure cannot be detected accurately.

[0005] Therefore, an object of the present invention is to provide an input device that can accurately detect pressure.

[0006] an input device according to an embodiment of the present disclosure, the input device comprising: a first conductive layer having a first electrode group in which a plurality of first electrodes extending in a first direction are arranged in a second direction perpendicular to the first direction; and a second electrode group in which a plurality of second electrodes extending in the second direction are arranged in the first direction; a second conductive layer having a third electrode; a deformation layer formed between the first conductive layer and the second conductive layer and capable of elastically deforming; a detection circuit connected to the first electrode group, detecting the capacitance of one or more detection electrodes selected from a plurality of the first electrodes, and outputting a detection signal corresponding to the detected capacitance; a first drive voltage source connected to the second electrode group, applying a first drive voltage to one or more drive electrodes selected from the plurality of the second electrodes; a second drive voltage source connected to the third electrode, applying a second drive voltage to the third electrode; and a control circuit for controlling the first drive voltage source and the second drive voltage source, wherein the third electrode is arranged to form a capacitance between the third electrode and the first electrode; The circuit is characterized in that it switches between a proximity detection mode in which the proximity of an object to be detected to the one or more detection electrodes is detected based on the detection signal, and a pressure detection mode in which the pressure of the object to be detected on the one or more detection electrodes is detected, and in the proximity detection mode, the first drive voltage source applies the first AC drive voltage to the one or more drive electrodes, and the second drive voltage source applies the second DC drive voltage to the third electrode, and in the pressure detection mode, the second drive voltage source applies the second AC drive voltage to the third electrode, and the first drive voltage source applies the first AC drive voltage, which has the same frequency as the second AC drive voltage but is opposite in phase to the one or more drive electrodes, and in the pressure detection mode, the first drive voltage source is electrically connected to the one or more detection electrodes via a capacitance and / or resistance adjusted so that the amplitude of the detection signal does not saturate within the output limit range of the detection circuit.

[0007] It is possible to provide an input device that can accurately detect pressure.

[0008] 1 is a diagram showing a planar configuration of an input device according to an embodiment; FIG. 2 is a diagram showing an example of a cross-sectional structure and circuit configuration of a portion of the input device according to an embodiment; FIG. 3 is a diagram showing an example of a cross-sectional structure and circuit configuration of a portion of the input device according to an embodiment; FIG. 4 is a diagram showing a flowchart illustrating an example of a mode switching control process (part 1) executed by a control circuit of the input device according to an embodiment; FIG. 5 is a diagram showing an example of a mode switching control process (part 2) executed by a control circuit of the input device according to an embodiment; FIG. 6 is a diagram showing an example of an equivalent circuit of the input device according to an embodiment in a pressure detection mode; FIG. 7 is a diagram showing an example of waveforms in a detection circuit of an input device for comparison; FIG. 8 is a diagram showing an example of waveforms in a detection circuit of the input device according to an embodiment;

[0009] Hereinafter, an embodiment to which the input device of the present disclosure is applied will be described.

[0010] <Embodiment> FIG. 1 is a diagram showing the planar configuration of an input device 100 according to an embodiment. The following description will define an XYZ coordinate system. The direction parallel to the X axis (X direction), the direction parallel to the Y axis (Y direction), and the direction parallel to the Z axis (Z direction) are perpendicular to each other. For ease of explanation, the −Z direction may be referred to as the lower side or bottom, and the +Z direction may be referred to as the upper side or top, but this does not represent a universal vertical relationship. Planar view refers to viewing from the XY plane. The following description may exaggerate the length, width, thickness, etc. of each part to make the configuration easier to understand.

[0011] The input device 100 includes a top panel 101 and a front-side electrode group 110. The input device 100 also includes a drive circuit and a detection circuit. The input device 100 also includes a control circuit and the like that detects the proximity, contact, and pressure of a user's fingertip or the like to the top panel 101, but these are omitted in Fig. 1, which shows only the planar configuration of the top panel 101 and the front-side electrode group 110.

[0012] The top panel 101 is, for example, a plate-like member made of transparent glass or resin that can bend when pressed from above, and is rectangular in plan view. The top surface is an operation surface on which a user can input operations by touching it with a fingertip or the like. The user can also press the top surface of the top panel 101 downward.

[0013] The front-side electrode group 110 has a plurality of front-side electrodes 110A. The plurality of front-side electrodes 110A are arranged on the underside of the top panel 101 and are arranged in a matrix in the X and Y directions. As an example, the plurality of front-side electrodes 110A are independent of one another and connected to a detection unit (described later) or the like via wiring (not shown) that is routed between them in a plan view.

[0014] Each of the multiple front-side electrodes 110A has a planar diamond shape, for example. However, each of the multiple front-side electrodes 110A may also have a square or rectangular, circular, or elliptical shape in a planar view, for example. The multiple front-side electrodes 110A are classified into an electrode group in which the electrodes are connected in the X direction and arranged in the Y direction, and an electrode group in which the electrodes are connected in the Y direction and arranged in the X direction. If the X direction is the first direction and the Y direction is the second direction, the electrode group in which the electrodes are connected in the X direction and arranged in the Y direction is an example of a first electrode group, and each electrode extending in the X direction is a first electrode. Furthermore, the electrode group in which the electrodes are connected in the Y direction and arranged in the X direction is an example of a second electrode group, and each electrode extending in the Y direction is a second electrode. Furthermore, if the Y direction is the first direction and the X direction is the second direction, an electrode group connected in the Y direction and having a plurality of electrodes arranged in the X direction is an example of a first electrode group, and an electrode group connected in the X direction and having a plurality of electrodes arranged in the Y direction is an example of a second electrode group. In other words, the front-side electrode group 110 (multiple front-side electrodes 110A) has a first electrode group and a second electrode group. Furthermore, the layer having the first electrode group and the second electrode group is an example of a first conductive layer.

[0015] The input device 100 selects one or more detection electrodes from one of the first electrode group and the second electrode group among the plurality of front-side electrodes 110A, and selects one or more drive electrodes from the other of the first electrode group and the second electrode group among the plurality of front-side electrodes 110A, to detect the XY coordinates of a position where an operation is being performed by a fingertip, etc. For this reason, Fig. 1 shows a drive circuit / detection circuit connected to each of an electrode group in which a plurality of electrodes are connected in the X direction and arranged in the Y direction, and an electrode group in which a plurality of electrodes are connected in the Y direction and arranged in the X direction.

[0016] In FIG. 1 , the plurality of front-side electrodes 110A are shown transparently. The plurality of front-side electrodes 110A are configured, for example, by transparent electrodes such as ITO (Indium Tin Oxide). Note that, here, a configuration in which the top panel 101 and the plurality of front-side electrodes 110A are transparent will be described assuming that a display panel such as a liquid crystal display or organic electroluminescence (EL) display is disposed below the input device 100. However, if, for example, a display panel is not disposed, the top panel 101 and the plurality of front-side electrodes 110A do not need to be transparent and may be made of a conductive material. In this case, the plurality of front-side electrodes 110A may be a metal plate or the like.

[0017] 2 and 3 are diagrams showing an example of a cross-sectional structure and circuit configuration of a portion of the input device 100. The input device 100 detects the proximity, contact, and pressure of a fingertip or the like by switching between a proximity detection mode that detects the proximity and contact of a fingertip or the like and a pressure detection mode that detects pressure by a fingertip or the like.

[0018] FIG. 2 shows an example of the state of the circuit in the proximity detection mode, and FIG. 3 shows an example of the state of the circuit in the pressure detection mode.

[0019] 2 and 3 show a cross-sectional structure of a portion where three front-side electrodes 110A arranged in the X direction are present. Here, as an example, a description will be given of a mode in which a user performs an operation input to the input device 100 using a fingertip FT. The fingertip FT is an example of a detection target. The user performs an operation input by bringing the fingertip FT close to the top panel 101 or by touching (contacting) the top panel 101 with the fingertip FT. Bringing the fingertip FT close to the top panel 101 means that the fingertip FT is not in contact with the top panel 101, but is close enough to the top panel 101 that the input device 100 can detect the coordinates of the fingertip FT and the distance between the fingertip FT and the top panel 101 based on electrostatic capacitance. In FIGS. 2 and 3, an inverted triangle represents ground.

[0020] <Input Device 100> In addition to the top panel 101 and the front-side electrode group 110, the input device 100 further includes a substrate 102, a conductor portion 110B, an elastic dielectric 120, a back-side electrode 130, a voltage source 140, a detection circuit 150, switches 161-166, and a control circuit 170. The elastic dielectric 120 is an example of an elastically deformable deformation layer. Note that the deformation layer does not necessarily have to be an elastic body; for example, even a layer of air surrounded by an elastic body can be considered an elastically deformable deformation layer. The back-side electrode 130 is an example of a third electrode and is arranged to form a capacitance with the first electrode. Furthermore, the layer having the back-side electrode 130 is an example of a second conductive layer. In other words, the elastic dielectric 120 can be considered to be formed between the first conductive layer and the second conductive layer. The detection circuit 150 is a circuit that can serve as the detection circuit of the drive circuit / detection circuit shown in FIG. 1.

[0021] 2 and 3 , the central surface side electrode 110A is a detection electrode 111, and the two surface side electrodes 110A on either side of the detection electrode 111 are drive electrodes 112. For this reason, the detection electrode 111 and the drive electrode 112 are denoted by the reference numeral 110A in parentheses. Note that, hereinafter, when the term "surface side electrode 110A" is used, it refers to a case where the detection electrode 111 and the drive electrode 112 are not particularly distinguished from each other, and when describing the surface side electrodes 110A other than the detection electrode 111 and the drive electrode 112.

[0022] The connection relationship between all of the multiple front-side electrodes 110A and the drive circuit / detection circuit is the same, but Figures 2 and 3 show the connection relationship between one front-side electrode 110A selected as the detection electrode 111 and two front-side electrodes 110A selected as the drive electrode 112.

[0023] <Detection electrodes 111> The detection electrodes 111 are electrodes used to detect the proximity, contact, and pressure of the user's fingertip FT on the top panel 101. The input device 100 detects the proximity, contact, and pressure of the fingertip FT by sequentially selecting the multiple front-side electrodes 110A one by one as the detection electrodes 111 and detecting the capacitance. When contact or pressure is detected by the selected detection electrode 111, it means that an operation input has been made at the position (coordinates) corresponding to that detection electrode 111.

[0024] Here, a description will be given of a configuration in which the plurality of surface-side electrodes 110A are selected one by one in turn as the detection electrodes 111, but two or more surface-side electrodes 110A may be simultaneously selected as the detection electrodes 111, and the proximity, contact, and pressure of the fingertip FT may be simultaneously detected by the two or more detection electrodes 111. Therefore, the plurality of surface-side electrodes 110A includes one or more detection electrodes 111.

[0025] <Driving electrode 112> The driving electrode 112 is a surface-side electrode 110A adjacent in the X direction to the detecting electrode 111. When the input device 100 selects the surface-side electrodes 110A one by one in order as the detecting electrodes 111, it selects the surface-side electrode 110A adjacent in the X direction to the detecting electrode 111 as the driving electrode 112.

[0026] Here, we will explain a form in which two surface electrodes 110A located on either side of the detection electrode 111 in the X direction are used as the driving electrodes 112. However, a total of four surface electrodes 110A, including two surface electrodes 110A located on either side of the detection electrode 111 in the X direction and two surface electrodes 110A located on either side of the detection electrode 111 in the Y direction, may also be used as the driving electrodes 112.

[0027] Furthermore, for example, when a surface-side electrode 110A located at an end in the X direction is used as the detection electrode 111, the two surface-side electrodes 110A on either side of the detection electrode 111 in the Y direction may be used as the two drive electrodes 112, or the surface-side electrode 110A adjacent to the detection electrode 111 on the +X direction side and the surface-side electrode 110A adjacent to the detection electrode 111 on the −Y direction side or the +Y direction side may be used as the two drive electrodes 112. Furthermore, when a surface-side electrode 110A located at a corner of a plurality of surface-side electrodes 110A arranged in a matrix is ​​used as the detection electrode 111, the surface-side electrode 110A adjacent to the detection electrode 111 in the X direction and the surface-side electrode 110A adjacent to the detection electrode 111 in the Y direction may be used as the two drive electrodes 112.

[0028] Furthermore, one surface side electrode 110A adjacent to the detection electrode 111 in the X direction may be used as a drive electrode, or one surface side electrode 110A adjacent to the detection electrode 111 in the Y direction may be used as a drive electrode.

[0029] <Conductor portion 110B> The conductor portion 110B is a conductor having a capacitance Ccmp between itself and the detection electrode 111, and has a resistance Rcmp. The resistance Rcmp is, for example, the resistance value of the conductor portion 110B itself. The resistance Rcmp and the capacitance Ccmp are connected in series. The resistance Rcmp is an example of a correction resistor, and the capacitance Ccmp is an example of a correction capacitance.

[0030] 2 and 3 show one conductor portion 110B coupled to one detection electrode 111, but in reality, one conductor portion 110B may be provided corresponding to each detection electrode 111, or a wide range of conductor portions 110B may be arranged such that a capacitance Ccmp is formed with respect to all the detection electrodes 111.

[0031] The input device 100 may have a configuration that does not include the conductor portion 110B, but here, a configuration that includes the conductor portion 110B will be described.

[0032] The capacitance Ccmp between the conductor portion 110B and the detection electrode 111 may be any of the following three configurations.

[0033] In the first configuration, the conductor portion 110B is coupled (capacitively coupled) to the detection electrode 111, and the capacitance Ccmp is the electrostatic capacitance between the conductor portion 110B and the detection electrode 111.

[0034] In the second configuration, the conductor portion 110B is connected to the detection electrode 111 via a capacitor having a capacitance Ccmp.

[0035] In the third configuration, the conductor portion 110B is connected to the wiring from the detection electrode 111 to the inverting input terminal of the operational amplifier 152 via a capacitor with a capacitance Ccmp.

[0036] Regarding the resistance Rcmp, a configuration in which the conductor portion 110B has the resistance Rcmp will be described as an example here, but a resistor having a resistance value Rcmp may be connected to the conductor portion 110B. Furthermore, the resistance value Rcmp may be a value that includes the resistance value of wiring or the like that is added in conjunction with the provision of the conductor portion 110B.

[0037] Such a conductor portion 110B may be a conductor or electrode that is included in the front-side electrode group 110 and arranged together with the plurality of front-side electrodes 110A, or may be a conductor or electrode that is provided outside the front-side electrode group 110. For example, the conductor portion 110B may be an electrode that is provided on the upper side of the front-side electrode group 110.

[0038] <Elastic Dielectric 120> The elastic dielectric 120 is provided below the plurality of front-side electrodes 110A (see FIGS. 1 to 3). The elastic dielectric 120 is, for example, a transparent, elastically deformable dielectric material, such as a urethane resin. The elastic dielectric 120 is provided at a position overlapping all of the plurality of front-side electrodes 110A in plan view, and has a uniform thickness in the Z direction. Because the elastic dielectric 120 is elastically deformable, when a user presses downward with a fingertip FT on a portion of the upper surface of the top panel 101 directly above the detection electrode 111, the elastic dielectric 120 flexes and contracts, causing the detection electrode 111 to be slightly displaced downward.

[0039] <Back-side electrode 130> The back-side electrode 130 is provided below the elastic dielectric 120, with the back-side electrode 130 being provided on the upper surface of the substrate 102. When viewed from the front-side electrode 110A side, the side below the elastic dielectric 120 is the back side of the elastic dielectric 120. The back-side electrode 130 is provided with the elastic dielectric 120 sandwiched between it and the plurality of front-side electrodes 110A.

[0040] The rear electrode 130 is made of a transparent conductive material such as an ITO film, for example. The substrate 102 is a transparent substrate that holds the rear electrode 130. For example, if a display panel is not placed underneath, the rear electrode 130 and the substrate 102 that holds the rear electrode 130 do not need to be transparent.

[0041] <Voltage source 140> The voltage source 140 has an AC voltage output unit 141, an inverting amplifier 142, and a DC voltage output unit 143. The AC voltage output unit 141, the inverting amplifier 142, the DC voltage output unit 143, and the switches 161 to 165 are circuits that can serve as the drive circuit of the drive circuit / detection circuit shown in FIG.

[0042] <AC voltage output unit 141> The AC voltage output unit 141 is connected to the front electrode 110A via a switch 163 and a switch 161. The AC voltage output unit 141 is connected to the back electrode 130 via a switch 164. The AC voltage output unit 141 is connected to the front electrode 110A via an inverting amplifier 142, a switch 162, and a switch 161. The AC voltage output unit 141 is connected to the front electrode 110A and the inverting input terminal of the operational amplifier 152 via the inverting amplifier 142, a switch 166, a conductor unit 110B (resistance Rcmp), and a capacitance Ccmp. The AC voltage output unit 141 outputs an AC voltage Vdrv.

[0043] As an example, the AC voltage output unit 141 is configured to be connectable to all of the plurality of front-side electrodes 110A via the switches 163 and 161. In the proximity detection mode, the AC voltage output unit 141 switches the connections of the switches 163 and 161 between the AC voltage output unit 141 and all of the plurality of front-side electrodes 110A, thereby connecting the AC voltage output unit 141 to two front-side electrodes 110A selected as the drive electrodes 112 as shown in FIG.

[0044] Also, as one example, the AC voltage output unit 141 is configured to be connectable to all of the plurality of front-side electrodes 110A via the inverting amplifier 142 and the switches 162 and 161. In the pressure detection mode, the AC voltage output unit 141 switches the connections of the switches 162 and 161 between itself and all of the plurality of front-side electrodes 110A, thereby connecting to the front-side electrode 110A selected as the drive electrode 112 as shown in FIG.

[0045] <Inverting amplifier 142> Inverting amplifier 142 has an input terminal connected to AC voltage output unit 141. Inverting amplifier 142 has output terminals connected to switch 162 and switch 166. A wire connected to the output terminal of inverting amplifier 142 branches into two wires, one of which is connected to switch 162 and the other of which is connected to switch 166.

[0046] The inverting amplifier 142 inverts the phase of and amplifies the AC voltage Vdrv input from the AC voltage output unit 141, and outputs the AC voltage Vcmp from the output terminal. The AC voltages Vcmp and Vdrv have opposite phases and the same frequency.

[0047] Note that two or more front-side electrodes 110A that are not adjacent to each other may be simultaneously selected as the detection electrodes 111 to simultaneously detect the proximity, contact, and pressure of the fingertip FT. In this case, an AC voltage Vdrv is applied to the drive electrode 112 that is capacitively coupled to one or more detection electrodes 111 in the proximity detection mode, and an AC voltage Vcmp is applied to the drive electrode 112 in the pressure detection mode.

[0048] <DC Voltage Output Unit 143> The DC voltage output unit 143 is connected to the back electrode 130 via the switch 165. The DC voltage output unit 143 outputs a DC voltage Vdc.

[0049] <Detection Circuit 150> The detection circuit 150 has an input terminal 151, an operational amplifier 152, a voltage output unit 152A, a capacitor 153, a resistor 154, and an output terminal 155. The detection circuit 150 detects the proximity, contact, and pressure of the user's fingertip FT using the detection electrodes 111. That is, the detection circuit 150 is connected to the first electrode group, detects the capacitance of one or more detection electrodes 111 selected from the plurality of first electrodes, and outputs a detection signal according to the detected capacitance.

[0050] As an example, the input terminal 151 is configured to be connectable to all of the plurality of surface electrodes 110A, and is connected to the surface electrode 110A selected as the detection electrode 111 by switching the wiring connection between the input terminal 151 and all of the plurality of surface electrodes 110A.

[0051] The operational amplifier 152 is an operational amplifier circuit having an inverting input terminal (-) connected to the detection electrode 111 via the input terminal 151, and a non-inverting input terminal (+) to which the voltage output unit 152A is connected and to which the reference voltage Vref is applied.

[0052] The voltage output unit 152A is connected to the non-inverting input terminal (+) of the operational amplifier 152 of the detection circuit 150, and outputs the reference voltage Vref. The reference voltage Vref is a DC voltage having a voltage value of Vref.

[0053] The capacitor 153 is connected between the inverting input terminal (-) and the output terminal of the operational amplifier 152. The capacitance (electrostatic capacitance) of the capacitor 153 is Cfb. The resistor 154 is connected in parallel with the capacitor 153. The resistance value of the resistor 154 is Rfb.

[0054] The output terminal 155 is connected to the output terminal of the operational amplifier 152. The output voltage of the output terminal 155 is V ０ The output voltage V ０is an example of a detection signal of the detection circuit 150. The operational amplifier 152 performs negative feedback operation using the feedback elements, capacitor 153 and resistor 154, and therefore performs amplification operation so that the voltage difference between the inverting input terminal (-) and the non-inverting input terminal (+) becomes zero. In other words, due to the virtual short circuit, the voltage at the inverting input terminal (-) becomes equal to the voltage applied to the non-inverting input terminal (+). Therefore, a reference voltage Vref is applied to the detection electrode 111.

[0055] Here, the multiple front-side electrodes 110A are arranged at equal intervals in the X and Y directions, and a capacitance (electrostatic capacitance) exists between adjacent front-side electrodes 110A. That is, the detection electrode 111 and the drive electrode 112 are coupled via a capacitance. In other words, the drive electrode 112 is coupled to the detection electrode 111 via a capacitance. Here, the capacitance between the detection electrode 111 and the drive electrode 112 on the -X direction side is defined as Cp1, and the capacitance between the detection electrode 111 and the drive electrode 112 on the +X direction side is defined as Cp2.

[0056] Furthermore, the capacitance (electrostatic capacitance) generated between the detection electrode 111 and the fingertip FT is denoted as Crg. The closer the fingertip FT is to the detection electrode 111, the larger the capacitance Crg becomes. Because the top panel 101 is located between the detection electrode 111 and the fingertip FT, the capacitance Crg becomes maximum when the fingertip FT is in contact with the upper surface of the top panel 101 directly above the detection electrode 111. Even when a pressing operation is performed in which the top panel 101 is pressed downward with the fingertip FT, the capacitance Crg remains approximately constant.

[0057] Furthermore, the capacitance (electrostatic capacitance) between the detection electrode 111 and the rear electrode 130 is defined as Crs. When a user presses downward with a fingertip FT a portion of the upper surface of the top panel 101 directly above the detection electrode 111, the elastic dielectric 120 bends and contracts, thereby shortening the distance d between the detection electrode 111 and the rear electrode 130. Therefore, when a pressing operation is performed, the capacitance Crs increases in accordance with the distance d between the detection electrode 111 and the rear electrode 130.

[0058] <Switches 161 to 166> The switches 161 to 166 are controlled to be turned on and off by the control circuit 170. Turning on any of the switches (161 to 166) means bringing the switch into a conductive state (closed state), and turning off any of the switches (161 to 166) means bringing the switch into a non-conductive state (open state).

[0059] The number of switches 161 provided is the same as the number of all the front-side electrodes 110A, and one switch 161 is connected to each front-side electrode 110A. One end of each switch 161 (the terminal on the right side in FIGS. 2 and 3) is connected to the front-side electrode 110A. The other ends of all the switches 161 (the terminals on the left side in FIGS. 2 and 3) are connected to switches 162 and 163.

[0060] The switch 162 is connected between the other ends (the left terminals in FIGS. 2 and 3) of all the switches 161 and the output terminal of the inverting amplifier 142. The number of the switch 162 is one.

[0061] The switch 163 is connected between the other ends (the left terminals in FIGS. 2 and 3) of all the switches 161 and the output terminal of the AC voltage output unit 141. The number of the switch 163 is one.

[0062] The switch 164 is connected between the back electrode 130 and the output terminal of the AC voltage output unit 141. The number of the switch 164 is one.

[0063] The switch 165 is connected between the rear electrode 130 and the output terminal of the DC voltage output unit 143. The number of the switch 165 is one.

[0064] The number of switches 166 provided is the same as the number of all the plurality of front-side electrodes 110A, and one switch 166 is connected to each front-side electrode 110A. When the number of conductor portions 110B provided is the same as the number of all the plurality of front-side electrodes 110A, one switch 166 is provided to each conductor portion 110B.

[0065] Each switch 166 is connected between the output terminal of the inverting amplifier 142 and the corresponding conductor portion 110B (resistance Rcmp), and is connected to the corresponding front electrode 110A and the input terminal 151 of the detection circuit 150 via the corresponding conductor portion 110B (resistance Rcmp) and capacitance Ccmp.

[0066] <Control circuit 170> The control circuit 170 is connected to the output terminal 155 of the detection circuit 150, and controls the output voltage V ０ Based on this, the proximity, contact, and pressure of the fingertip FT to the top panel 101 are detected.

[0067] The control circuit 170 is realized by, for example, a computer including a central processing unit (CPU), random access memory (RAM), read only memory (ROM), an input / output interface, an internal bus, and the like.

[0068] The control circuit 170 controls switching between a proximity detection mode and a pressure detection mode. Specifically, the control circuit 170 switches between a proximity detection mode in which the proximity of a detection object to one or more detection electrodes 111 is detected based on a detection signal, and a pressure detection mode in which the pressure of the detection object on one or more detection electrodes 111 is detected. The control circuit 170 also controls the voltage source 140 and controls the on / off switching of the switches 161 to 166 depending on the mode (either the proximity detection mode or the pressure detection mode). While performing these controls, the control circuit 170 controls the output voltage V ０ Based on this, the proximity, contact, and pressure of the fingertip FT to the top panel 101 are detected.

[0069] The control circuit 170 uses three thresholds to distinguish between proximity, contact, and pressure when detecting proximity, contact, and pressure. The control circuit 170 controls the output voltage V ０ becomes equal to or greater than the first threshold value V1, the control circuit 170 detects that the fingertip FT is approaching the top panel 101. ０becomes equal to or greater than the second threshold V2, the control circuit 170 detects the contact of the fingertip FT with the top panel 101. The second threshold V2 is greater than the first threshold V1. ０ becomes equal to or greater than the third threshold V3, the pressing of the fingertip FT on the top panel 101 is detected.

[0070] The first threshold V1 and the second threshold V2 are values ​​set for a voltage according to the distance from the top panel 101 to the fingertip FT. Detecting proximity and contact using the first threshold V1 and the second threshold V2 is synonymous with detecting proximity and contact according to the distance from the top panel 101 to the fingertip FT. Furthermore, because the distance between the top panel 101 and the front-side electrode 110A is constant, detecting proximity and contact according to the distance from the top panel 101 to the fingertip FT is synonymous with detecting proximity and contact according to the distance from the front-side electrode 110A to the fingertip FT.

[0071] Furthermore, the third threshold V3 is a value set for a voltage according to the distance between the front electrode 110A and the back electrode 130, which changes with pressure while maintaining contact. Detecting a pressure using the third threshold V3 is equivalent to detecting a pressure from the fingertip FT on the top panel 101. Furthermore, because the distance between the top panel 101 and the front electrode 110A is constant, detecting a pressure from the fingertip FT on the top panel 101 is equivalent to detecting a pressure according to the distance between the front electrode 110A and the back electrode 130.

[0072] Hysteresis may also be provided when detecting proximity, contact, and pressure. For example, in the proximity detection mode, the control circuit 170 controls the detection signal (output voltage V ０ ), when it is detected that the object to be detected has approached within a first predetermined distance from any of the one or more detection electrodes 111, the mode is switched from the proximity detection mode to the pressure detection mode, and in the pressure detection mode, a detection signal (output voltage V ０) that the detection object has moved away from any of the one or more detection electrodes 111 by a second predetermined distance or more, the pressure detection mode may be switched to the proximity detection mode. By making the first predetermined distance shorter than the second predetermined distance, hysteresis can be provided in the determination when switching to the proximity detection mode. Even if the detection object moves away a little after switching to the pressure detection mode, the determination in the pressure detection mode can be stably performed without immediately switching from the pressure detection mode.

[0073] The second threshold value V2 can be used as a value corresponding to the first predetermined distance. For example, the control circuit 170 may set the output voltage V ０ When the output voltage V becomes equal to or greater than a second threshold V2, the control circuit 170 detects contact and switches from the proximity detection mode to the pressure detection mode. The first threshold V1 can also be used as a value corresponding to the second predetermined distance. For example, the control circuit 170 may detect the output voltage V ０ becomes equal to or smaller than the first threshold V1, the mode may be switched from the pressure detection mode to the proximity detection mode.

[0074] <Flowchart of Mode Switching Control (Part 1)> FIG. 4A is a flowchart illustrating an example of a mode switching control process (part 1) executed by control circuit 170. As shown in FIG.

[0075] The control circuit 170 starts processing when the input device 100 is started, and executes the proximity detection mode (step S1). Since operations are performed in the order of proximity, contact, and pressure, immediately after start-up, the control circuit 170 sets the input device 100 to the proximity detection mode, which detects proximity and contact.

[0076] The control circuit 170 determines whether or not a contact has been detected (step S2). Whether or not a contact has been detected is determined by the output voltage V ０ becomes equal to or greater than the second threshold V2. In the proximity detection mode, the control circuit 170 always executes the process of step S2.

[0077] When the control circuit 170 determines that contact has been detected (S2: Yes), it switches to the pressure detection mode (step S3). After contact has been made, there is a possibility that pressure may occur, so the control circuit 170 transitions to the pressure detection mode.

[0078] The control circuit 170 determines whether or not a pressure is detected (step S4). Whether or not a pressure is detected is determined by the output voltage V ０ becomes equal to or greater than the third threshold V3.

[0079] If the control circuit 170 determines that a pressure has been detected (S4: Yes), it returns the flow to step S3 and continues the pressure detection mode in order to determine whether pressure is still being applied.

[0080] If the control circuit 170 determines in step S2 that contact has not been detected (S2: No), the control circuit 170 returns the flow to step S1 in order to continue the proximity detection mode until contact is detected.

[0081] Furthermore, if the control circuit 170 determines in step S4 that no pressure has been detected (S4: No), the control circuit 170 returns the flow to step S1 and transitions to the proximity detection mode.

[0082] Control circuit 170 repeatedly executes the processes of steps S1 to S4, while controlling voltage source 140 and controlling the on / off switching of switches 161 to 166. Details of the control of voltage source 140 and the on / off switching control of switches 161 to 166 will be described later.

[0083] <Flowchart of Mode Switching Control (Part 2)> Fig. 4B is a flowchart illustrating an example of the mode switching control process (Part 2) executed by the control circuit 170. The control circuit 170 may execute the process shown in Fig. 4B instead of the process shown in Fig. 4A.

[0084] When the input device 100 is started, the control circuit 170 starts processing and executes the intermittent proximity detection mode (step S1A).

[0085] The control circuit 170 intermittently determines whether proximity or contact has been detected (step S2A). In the intermittent proximity detection mode, the control circuit 170 does not constantly determine whether proximity or contact has been detected, but performs the determination intermittently, for example, every 3 to 10 seconds. Whether proximity has been detected is determined by the output voltage V ０ is equal to or greater than the first threshold value V1, and whether or not contact has been detected is determined by the output voltage V ０ becomes equal to or greater than the second threshold value V2.

[0086] When the control circuit 170 determines that proximity or contact has been detected (S2A: Yes), it switches to the proximity detection mode (step S2B). After either proximity or contact has occurred, the control circuit 170 switches to the proximity detection mode and determines whether contact has been detected. Step S2B is the same process as step S1 in FIG. 4A.

[0087] After switching to the proximity detection mode in step S2B, the control circuit 170 determines whether contact has been detected (step S2C). Step S2C is the same process as step S2 in FIG. 4A. If the control circuit 170 determines that contact has been detected (S2B: Yes), it switches to the pressure detection mode (step S3). After contact has been made, there is a possibility that pressure may occur, so the control circuit 170 transitions to the pressure detection mode. Step S3 in FIG. 4B is the same as step S3 in FIG. 4A.

[0088] The control circuit 170 determines whether or not a pressure is detected (step S4). Step S4 in Fig. 4B is the same as step S4 in Fig. 4A.

[0089] If the control circuit 170 determines that a pressure has been detected (S4: Yes), it returns the flow to step S3 and continues the pressure detection mode in order to determine whether pressure is still being applied.

[0090] If the control circuit 170 determines in step S2A that proximity or contact has not been detected (S2A: No), the control circuit 170 returns the flow to step S1A in order to continue the indirect proximity detection mode until proximity is detected.

[0091] If the control circuit 170 determines in step S2C that contact has not been detected (S2C: No), the control circuit 170 returns the flow to step S2A in order to continue the proximity detection mode until contact is detected.

[0092] Furthermore, if the control circuit 170 determines in step S4 that no pressure has been detected (S4: No), the flow returns to step S2B in order to transition to the proximity detection mode until contact is detected.

[0093] Control circuit 170 repeatedly executes the processes of steps S1A to S4, while controlling voltage source 140 and controlling the on / off switching of switches 161 to 166. Details of the control of voltage source 140 and the on / off switching control of switches 161 to 166 will be described later.

[0094] <Proximity Detection Mode (FIG. 2)> In the proximity detection mode, as shown in FIG. 2, the control circuit 170 turns on the switches 161 connected to two drive electrodes 112 (the other switches 161 are off), turns off the switch 162, and turns on the switch 163. The control circuit 170 also turns off the switch 164, turns on the switch 165, and turns off all the switches 166.

[0095] In the proximity detection mode, the control circuit 170 controls the AC voltage output unit 141 and the DC voltage output unit 143 of the voltage source 140 to output the AC voltage Vdrv and the DC voltage Vdc, respectively.

[0096] Therefore, in the proximity detection mode, no voltage is applied to the detection electrode 111 from the voltage source 140, an AC voltage Vdrv is applied to the drive electrode 112 from the AC voltage output unit 141 of the voltage source 140, and a DC voltage Vdc is applied to the back electrode 130 from the DC voltage output unit 143.

[0097] At this time, a current (detection current) flows from the drive electrode 112 to the detection electrode 111 as shown by the arrow through the capacitances Cp1 and Cp2 between the two drive electrodes 112 and one detection electrode 111. Since the detection current flows to the detection electrode 111 only through the capacitances Cp1 and Cp2, the output voltage V０ becomes a voltage value that accurately reflects the change in capacitances Cp1 and Cp2 due to the proximity or contact of the fingertip FT.

[0098] Therefore, in the proximity detection mode, the coordinates of the fingertip FT can be detected accurately.

[0099] Of the voltage sources 140, the AC voltage output unit 141 that applies Vdrc (first drive voltage) to the drive electrodes 112 in the proximity detection mode is an example of a first drive voltage source. That is, the AC voltage output unit 141 is connected to the second electrode group and applies the first drive voltage to one or more drive electrodes 112 selected from the plurality of second electrodes. The DC voltage output unit 143 is an example of a second drive voltage source that is connected to the back electrode 130 and applies Vdc (second drive voltage) to the back electrode 130 in the proximity detection mode.

[0100] <Press Detection Mode (FIG. 3)> In the press detection mode, as shown in FIG. 3, the control circuit 170 turns on switches 161 connected to two drive electrodes 112 (the other switches 161 are off), turns on switch 162, and turns off switch 163. The control circuit 170 also turns on switch 164, turns off switch 165, and turns on switch 166 connected to the detection electrode 111 (the other switches 166 are off).

[0101] In the pressure detection mode, the control circuit 170 drives the AC voltage output unit 141 of the voltage source 140 to output the AC voltage Vdrv. In the pressure detection mode, the control circuit 170 turns off the DC voltage output unit 143.

[0102] Therefore, in the pressure detection mode, an AC voltage Vcmp is applied to the detection electrode 111 from the inverting amplifier 142 via the conductor portion 110B and the capacitance Ccmp, an AC voltage Vcmp is applied to the drive electrode 112 from the inverting amplifier 142, and an AC voltage Vdrv is applied to the back electrode 130 from the AC voltage output unit 141. The AC voltages Vcmp and Vdrv are in opposite phases and have the same frequency.

[0103] Of the voltage source 140, the AC voltage output unit 141 and the inverting amplifier 142, which apply Vcmp (first drive voltage) to the drive electrodes 112 in the pressure detection mode, are an example of a first drive voltage source. In this case, the inverting amplifier 142 is connected to the second electrode group and applies the first drive voltage to one or more drive electrodes 112 selected from the plurality of second electrodes. Also, in the pressure detection mode, the AC voltage output unit 141 is an example of a second drive voltage source and is connected to the back electrode 130 and applies Vdrv (second drive voltage) to the back electrode 130. In other words, the control circuit 170 controls the first drive voltage source and the second drive voltage source by controlling each switch. In the proximity detection mode, the control circuit 170 applies an AC first drive voltage to one or more drive electrodes 112 using the first drive voltage source and applies a DC second drive voltage to the back electrode 130 using the second drive voltage source. Furthermore, in the pressure detection mode, the control circuit 170 causes the second drive voltage source to apply a second AC drive voltage to the back electrode 130, and causes the first drive voltage source to apply a first AC drive voltage, which has the same frequency as the second AC drive voltage but is opposite in phase to the second AC drive voltage, to one or more drive electrodes 112. Furthermore, in the pressure detection mode, the first drive voltage source is electrically connected to one or more detection electrodes 111 via capacitance and / or resistance adjusted so that the amplitude of the detection signal does not saturate within the output limit range of the detection circuit 150. In FIG. 3 , the AC voltage output unit 141 and the inverting amplifier 142 correspond to the first drive voltage source, and therefore the inverting amplifier 142 can be said to be electrically connected to the detection electrode 111 via the drive electrode 112 and capacitance Cp1 (or Cp2). Therefore, the resistance values ​​of the detection electrode 111 and the drive electrode 112, as well as the capacitance value of capacitance Cp1 (or Cp2), are adjusted so that the amplitude of the detection signal does not saturate within the output limit range of the detection circuit 150. In addition, the resistance value of the resistor Rcmp of the conductor portion 110B and the capacitance value of the capacitor Ccmp between the conductor portion 110B and the detection electrode 111 are also adjusted so that the amplitude of the detection signal does not saturate within the output limit range of the detection circuit 150.

[0104] <Details of Operation in Pressure Detection Mode (FIG. 5)> FIG. 5 is a diagram showing an example of an equivalent circuit of the input device 100 in the pressure detection mode. FIG. 5 shows the detection electrode 111, the drive electrode 112, the conductor portion 110B, the back electrode 130, the AC voltage output portion 141, the inverting amplifier 142, and the detection circuit 150 (input terminal 151, operational amplifier 152, voltage output portion 152A, capacitor 153, resistor 154, and output terminal 155). The detection electrode 111, the drive electrode 112, and the back electrode 130 are shown as resistors. Furthermore, two drive electrodes 112 are collectively shown as one drive electrode 112.

[0105] FIG. 5 also shows the capacitances Crs0 and Crs between the detection electrode 111 and the back electrode 130, the capacitance Cp between the detection electrode 111 and the drive electrode 112, the capacitance Crg between the detection electrode 111 and the fingertip FT, the capacitance Crgl between the detection electrode 111 and ground (GND), and the capacitance Ccmp between the conductor portion 110B and the detection electrode 111.

[0106] The capacitance Crs0 is the capacitance between the detection electrode 111 and the rear electrode 130 when the top panel 101 is not pressed by the fingertip FT. The capacitance Crs is the increased capacitance between the detection electrode 111 and the rear electrode 130 when the top panel 101 is pressed by the fingertip FT and displaced downward. For this reason, the capacitance Crs is represented by the symbol for a variable capacitor. Furthermore, the capacitance Cp is the combined capacitance of the capacitances Cp1 and Cp2 shown in FIGS. 2 and 3, and is the capacitance represented by the sum of the capacitances Cp1 and Cp2.

[0107] In the input device 100 in the pressure detection mode, an AC voltage Vcmp having the opposite phase and the same frequency as the AC voltage Vdrv applied as a drive voltage to the rear electrode 130 is applied to the drive electrode 112 and also to the detection electrode 111 via the conductor portion 110B.

[0108] Therefore, in the detection electrode 111 coupled to the rear electrode 130 via the capacitances Crs0 and Crs, a part of the AC current (first AC current) flowing from the rear electrode 130 via the capacitances Crs0 and Crs is cancelled out by the AC current (second AC current) of the same frequency and in the opposite phase flowing from the drive electrode 112 and the conductor portion 110B. As a result, the output voltage V０ The amplitude of becomes smaller.

[0109] In this way, the output voltage V of the detection circuit 150 ０ When the amplitude of becomes smaller, when the capacitance Crs changes due to pressure, the output voltage V ０ Since the change in amplitude of can be made large, the output voltage V ０ In particular, the dynamic range of the output voltage V ０ If the capacitance Crs0 of the output voltage V is offset by a current of the same frequency and in the opposite phase flowing from the driving electrode 112 and the conductor portion 110B to the detection electrode 111, the output voltage V ０ This can maximize the dynamic range of the image. Details of this will be described later with reference to FIGS. 6A and 6B.

[0110] In addition, if the input device 100 does not include the conductor portion 110B, it is possible to cancel out a portion of the current component flowing from the rear electrode 130 into the detection electrode 111 in this manner by a current of the same frequency but in the opposite phase flowing from the drive electrode 112 into the detection electrode 111.

[0111] Furthermore, when the input device 100 includes the conductor portion 110B, the following becomes even more possible. When realizing current cancellation as described above, if the resistance values ​​of the detection electrode 111 and the drive electrode 112 are large, the phase of the current flowing from the drive electrode 112 into the detection electrode 111 via the capacitance Cp may not be opposite to the phase of the current flowing from the back electrode 130 via the capacitances Crs0 and Crs. This is because the phase of the current flowing from the drive electrode 112 into the detection electrode 111 via the capacitance Cp is shifted due to the large resistance values ​​of the detection electrode 111 and the drive electrode 112.

[0112] In such a case, by setting the resistance Rcmp and capacitance Ccmp of the conductor portion 110B to appropriate values, it is possible to adjust the phase of the current flowing from the drive electrode 112 to the detection electrode 111 via the capacitance Cp so that it is in the opposite phase to the phase of the current flowing from the back electrode 130 via the capacitances Crs0 and Crs.

[0113] <Output voltage V of the detection circuit 150 of the input device for comparison ０ 6A, the dynamic range of the output voltage V ０ 6A shows the dynamic range of the AC voltage Vdrv (dash-dotted line) applied to the back electrode 130 in the detection circuit 150 of the comparative input device, and the output voltage V ０ (dashed line), and the maximum amplitude output voltage V when pressure is applied (hereinafter referred to as "pressed"). ０ FIG. 10 is a diagram showing an example of the solid line.

[0114] 6A, the horizontal axis represents time, and the vertical axis represents voltage (amplitude). The vertical axis of FIG. 6A also represents the voltage range of the detection circuit. The voltage range of the detection circuit represents the range of maximum voltage (amplitude) that can be detected by the detection circuit 150, and is an example of the output limit range of the detection circuit 150.

[0115] The comparative input device is configured by omitting the conductor portion 110B, the switch 166, the inverting amplifier 142, and the switch 162 from the input device 100 shown in Figure 3, and in the pressure detection mode, no voltage is applied to the drive electrode 112, and an AC voltage Vdrv is applied to the back electrode 130.

[0116] In such a comparative input device, as shown in FIG. 6A, the output voltage V ０ Since the amplitude of (dashed line) becomes larger, the output voltage V ０ The amplitude of (solid line) exceeds the voltage range of the detection circuit, and the output voltage V ０ In this case, the waveform of the output voltage V ０ The dynamic range of the output voltage V ０ (dashed line) and the output voltage V ０ The difference (double arrow) between the amplitude of the (solid line) and the amplitude of the (solid line) is very small.

[0117] <Output voltage V of the detection circuit 150 of the input device 100 according to the embodiment ０6B shows the dynamic range of the AC voltage Vdrv (dashed line) applied to the rear electrode 130 in the detection circuit 150 of the input device 100, the AC voltage Vcmp (dashed line) applied to the drive electrode 112, and the output voltage V ０ (Dotted line) Maximum amplitude output voltage V when pressed ０ 6B is a diagram showing an example of a voltage range of the detection circuit 150 (solid line), which is the range of maximum voltages (amplitudes) that can be detected by the detection circuit 150, as in the case of FIG.

[0118] 6B, the AC voltage Vdrv (dashed line) applied to the back electrode 130 and the AC voltage Vcmp (dashed line) applied to the drive electrode 112 are in opposite phase, have the same frequency, and are equal in amplitude. When the AC voltages Vdrv and Vcmp have the same amplitude, the configuration of the inverting amplifier 142 and the like can be simplified.

[0119] In the input device 100, a part of the current component flowing from the rear electrode 130 to the detection electrode 111 via the capacitances Crs0 and Crs is cancelled by a current of the same frequency and in opposite phase flowing from the drive electrode 112 to the detection electrode 111. ０ The amplitude of the (dashed line) becomes smaller. ０ The amplitude of the output voltage V (solid line) is within the voltage range of the detection circuit and is not saturated. ０ The dynamic range of the output voltage V ０ (dashed line) and the output voltage V ０ This is the difference (double arrow) between the amplitude of the (solid line) and the amplitude of the (double arrow) and can be made very large.

[0120] In the input device 100, when the conductor portion 110B is not included, the output voltage V ０ The capacitance Cp (Cp1+Cp2) can be adjusted so that the maximum amplitude of the signal (solid line) falls within the voltage range of the detection circuit. ０ In addition to the capacitance Cp (Cp1+Cp2), the electrode resistances of the detection electrode 111 and the drive electrode 112 may be adjusted so that the maximum amplitude of the (solid line) falls within the voltage range of the detection circuit.

[0121] In addition, in the input device 100, in the case where the conductor portion 110B is included, as shown in FIG. 6B, the output voltage V ０ The capacitances Cp (Cp1+Cp2), Ccmp, and Rcmp may be adjusted so that the maximum amplitude of the signal (solid line) falls within the voltage range of the detection circuit. Furthermore, the electrode resistances of the detection electrode 111 and the drive electrode 112 may be adjusted.

[0122] <Effects> The input device 100 includes a surface-side electrode group 110 having a first electrode group in which a plurality of first electrodes (surface-side electrodes 110A) extending in a first direction are arranged in a second direction perpendicular to the first direction, and a second electrode group in which a plurality of second electrodes (surface-side electrodes 110A) extending in the second direction are arranged in the first direction, a second conductive layer having a back-side electrode 130, an elastically deformable elastic dielectric 120 formed between the surface-side electrode group 110 and the back-side electrode 130, and a detection electrode 111 connected to the first electrode group, which detects the capacitance of one or more detection electrodes 111 selected from the plurality of first electrodes (surface-side electrodes 110A), and outputs a detection signal (output voltage V ０ ), a first drive voltage source connected to the second electrode group and applying a first drive voltage to one or more drive electrodes 112 selected from a plurality of second electrodes (front-side electrodes 110A), a second drive voltage source connected to the back-side electrode 130 and applying a second drive voltage to the back-side electrode 130, and a control circuit 170 controlling the first drive voltage source and the second drive voltage source, the back-side electrode 130 being disposed so as to form a capacitance with the first electrode (front-side electrode 110A), and the control circuit 170 outputs a detection signal (output voltage V ０), the device switches between a proximity detection mode in which proximity of an object to be detected to one or more detection electrodes 111 is detected, and a pressure detection mode in which pressure of the object to be detected on one or more detection electrodes 111 is detected. In the proximity detection mode, a first AC drive voltage is applied to one or more drive electrodes 112 by a first drive voltage source, and a second DC drive voltage is applied to the back electrode 130 by a second drive voltage source. In the pressure detection mode, a second AC drive voltage is applied to the back electrode 130 by a second drive voltage source, and a first AC drive voltage having the same frequency as the second AC drive voltage but an opposite phase to the second AC drive voltage is applied to one or more drive electrodes 112 by a first drive voltage source. In the pressure detection mode, the device outputs a detection signal (output voltage V ０ ) is electrically connected to one or more detection electrodes 111 via a capacitance and / or a resistance adjusted so that the amplitude of the detection signal (output voltage V ０ ) can be kept within the output limit range of the detection circuit 150. As explained above, the conductor portion 110B is not an essential component, and even without the conductor portion 110B, the output voltage V can be reduced by adjusting the capacitance Cp (Cp1+Cp2), the resistance value of the drive electrode 112, or the resistance value of the detection electrode 111. ０ However, by providing the conductor portion 110B and adjusting the resistance Rcmp and capacitance Ccmp, an even greater effect can be obtained.

[0123] Therefore, it is possible to provide the input device 100 that can accurately detect pressure.

[0124] The control circuit 170 may be characterized by entering a proximity detection mode upon startup. Since operations are performed in the order of proximity, contact, and pressure, proximity or contact can be detected early by entering the proximity detection mode immediately after startup.

[0125] In addition, in the proximity detection mode, the control circuit 170 generates a detection signal (output voltage V ０), when it is detected that the object to be detected has approached within a first predetermined distance from any of the one or more detection electrodes 111, the mode is switched to the pressure detection mode, and in the pressure detection mode, a detection signal (output voltage V ０ ) that the object to be detected is at a distance equal to or greater than a second predetermined distance from any one or more of the detection electrodes 111. Switching to and from the proximity detection mode can be reliably performed depending on the distance between the object to be detected and the detection electrodes 111.

[0126] The first predetermined distance may be shorter than the second predetermined distance, so that even if the object to be detected moves a little further away after switching to the proximity detection mode, the mode can be stably switched from the proximity detection mode without immediately switching from the proximity detection mode.

[0127] The sensor may further include a conductor 110B connected to a first drive voltage source. The dynamic range can be increased by utilizing the capacitance between the conductor 110B and the detection electrode 111.

[0128] The conductor portion 110B also outputs a detection signal (output voltage V ０ The detection signal (output voltage V) may be electrically connected to one or more detection electrodes 111 via a second correction resistor (Rcmp) and a second correction capacitor (Ccmp) that are adjusted so that the amplitude of the detection signal (output voltage V) is not saturated within the output limit range of the detection circuit 150, or may be connected to wiring from one or more detection electrodes 111 to the detection circuit 150 via the second correction resistor (Rcmp) and the second correction capacitor (Ccmp). ０ ) to adjust the amplitude of the detection signal (output voltage V ０ ) can be reliably adjusted so that it does not saturate within the output limit range of the detection circuit 150.

[0129] The conductor portion 110B also outputs a detection signal (output voltage V ０The detection circuit 150 may have a second correction resistor that is adjusted so that the amplitude of the detection signal (output voltage V ０ ) to adjust the amplitude of the detection signal (output voltage V ０ ) can be reliably adjusted so that it does not saturate within the output limit range of the detection circuit 150.

[0130] Furthermore, in the pressure detection mode, the control circuit 170 applies to the conductor portion 110B a first AC drive voltage (Vcmp) having the same frequency but the opposite phase to the second AC drive voltage, and the correction resistor and correction capacitor may be set to resistance values ​​and capacitance values ​​that correct a phase shift of the second AC current flowing into one or more detection electrodes 111 due to the first AC drive voltage (Vcmp) having the same frequency but the opposite phase to the second AC drive voltage (Vdrv) applied to the conductor portion 110B, relative to the first AC current flowing into one or more detection electrodes 111 due to the second AC drive voltage (Vdrv) applied to the backside electrode 130 in the pressure detection mode. When the resistance values ​​of the detection electrodes 111 and the drive electrodes 112 are large and the phase shift between the first AC current and the second AC current is large, the phase shift between the first AC current and the second AC current is corrected, thereby canceling out the first AC current and the second AC current, and generating a detection signal (output voltage V ０ ) can definitely improve the dynamic range.

[0131] The above describes an input device according to an exemplary embodiment of the present disclosure, but the present disclosure is not limited to the specifically disclosed embodiment, and various modifications and variations are possible without departing from the scope of the claims.

[0132] This international application claims priority based on Japanese Patent Application No. 2024-065582, filed on April 15, 2024, the entire contents of which are incorporated herein by reference.

[0133] 100 Input device 101 Top panel 102 Substrate 110 Front electrode group 110A Front electrode 110B Conductor portion 120 Elastic dielectric 130 Back electrode 140 Voltage source 141 AC voltage output portion 142 Inverting amplifier 143 DC voltage output portion 150 Detection circuit 151 Input terminal 152 Operational amplifier 152A Voltage output portion 153 Capacitor 154 Resistor 155 Output terminal 161 to 166 Switch 170 Control circuit

Claims

1. A device comprising: a first conductive layer having a first electrode group in which a plurality of first electrodes extending in a first direction are arranged in a second direction perpendicular to the first direction; and a second electrode group in which a plurality of second electrodes extending in the second direction are arranged in the first direction; a second conductive layer having a third electrode; a deformation layer formed between the first conductive layer and the second conductive layer and capable of elastically deforming; a detection circuit connected to the first electrode group, detecting the capacitance of one or more detection electrodes selected from a plurality of the first electrodes, and outputting a detection signal corresponding to the detected capacitance; a first drive voltage source connected to the second electrode group, applying a first drive voltage to one or more drive electrodes selected from the plurality of the second electrodes; a second drive voltage source connected to the third electrode, applying a second drive voltage to the third electrode; and a control circuit for controlling the first drive voltage source and the second drive voltage source, wherein the third electrode is arranged to form a capacitance between the third electrode and the first electrode, and the control circuit an input device which switches between a proximity detection mode in which the proximity of a detection object to the one or more detection electrodes is detected based on the detection signal, and a pressure detection mode in which the pressure of the detection object on the one or more detection electrodes is detected; in the proximity detection mode, the first drive voltage source applies the first AC drive voltage to the one or more drive electrodes, and the second drive voltage source applies the second DC drive voltage to the third electrode; in the pressure detection mode, the second drive voltage source applies the second AC drive voltage to the third electrode, and the first drive voltage source applies the first AC drive voltage, which has the same frequency as the second AC drive voltage but is opposite in phase to the one or more drive electrodes; and in the pressure detection mode, the first drive voltage source is electrically connected to the one or more detection electrodes via a capacitance and / or resistance adjusted so that the amplitude of the detection signal does not saturate within the output limit range of the detection circuit.

2. The input device of claim 1, wherein the control circuit is in the proximity detection mode upon activation.

3. The input device of claim 1, wherein the control circuit switches to the pressure detection mode when it detects, based on the detection signal, that the object to be detected has come within a first predetermined distance of any of the one or more detection electrodes in the proximity detection mode, and switches from the proximity detection mode when it detects, based on the detection signal, that the object to be detected has come away from any of the one or more detection electrodes by a second predetermined distance or more in the pressure detection mode.

4. The input device according to claim 3, wherein the first predetermined distance is shorter than the second predetermined distance.

5. An input device according to any one of claims 1 to 4, further comprising a conductor portion connected to said first drive voltage source.

6. An input device as described in claim 5, characterized in that the conductor portion is connected to the one or more detection electrodes via a compensation resistor and a compensation capacitor that are adjusted so that the amplitude of the detection signal does not saturate within the output limit range of the detection circuit, or is connected to wiring from the one or more detection electrodes to the detection circuit via the compensation resistor and the compensation capacitor.

7. An input device as described in claim 5, characterized in that the conductor portion has a compensation resistor adjusted so that the amplitude of the detection signal does not saturate within the output limit range of the detection circuit, and is connected to the one or more detection electrodes via a compensation capacitance, or has the compensation resistor and is connected to wiring from the one or more detection electrodes to the detection circuit via the compensation capacitance.

Images