Sensor device and electronic apparatus

Abstract

A sensor device according to an embodiment of the present technology comprises: a sensor sheet; a reference electrode layer; a deformation layer; a surface layer; and a control unit. The sensor sheet is configured to detect a pressure profile. The reference electrode layer is disposed to face a surface of one side of the sensor sheet, and is connected to a reference potential. The deformation layer is disposed between the sensor sheet and the reference electrode layer, and is made of a flexible material. The surface layer has an input operation surface, is disposed on the surface of the other side of the sensor sheet, and is composed of a non-conductive material thicker than the deformation layer. The control unit sets a plurality of thresholds for determining a magnitude of a pressing force to be applied to the input operation surface across a plurality of levels based on an output from the sensor sheet.

Description

Technical Field

[0001] This technology relates to sensor devices and electronic devices capable of detecting touch and press operations. Background Technology

[0002] As a capacitive sensor capable of detecting touch and press operations, for example, Patent Document 1 discloses a sensor that includes a ground electrode, a first electrode disposed on the ground electrode and composed of a plurality of first sub-electrodes, a deformable layer disposed between a mounting electrode and the first electrode, a second electrode disposed on the first electrode and composed of a plurality of second sub-electrodes, and a surface layer disposed on the second electrode and having an operating surface.

[0003] Reference List

[0004] Patent documents

[0005] Patent Document 1: WO 2018 / 025690 Summary of the Invention

[0006] Technical issues

[0007] In recent years, there has been a growing demand for capacitive sensors with a sensor structure that can distinguish between touch and pressure sensing functions, classify pressure sensing functions into multiple levels, and assign different functions according to the amount of pressure applied. To achieve this, the pressure sensitivity when a finger presses on the operating surface must be sufficiently higher than the touch sensitivity when the finger touches the operating surface.

[0008] In view of this situation, this technology has achieved the goal of providing sensor devices and electronic devices that can set pressure sensitivity to be sufficiently higher than touch sensitivity and divide pressure sensing functions into multiple levels.

[0009] Solution to the problem

[0010] The sensor device according to embodiments of the present technology includes: a sensor chip; a reference electrode layer; a deformable layer; a surface layer; and a control unit.

[0011] The sensor chip is configured to detect the distribution of pressure.

[0012] The reference electrode layer is arranged on one side of the sensor sheet and connected to a reference potential.

[0013] The deformable layer is disposed between the sensor sheet and the reference electrode layer and is made of a flexible material.

[0014] The surface layer has an input operation surface, which is disposed on the surface on the other side of the sensor sheet, and is made of a non-conductive material that is thicker than the deformable layer.

[0015] The control unit is capable of performing a first detection process based on the output from the sensor chip to detect the contact between the object being detected and the input operating surface, and a second detection process to detect the pressure applied by the object being detected to the input operating surface. The control unit sets multiple thresholds to determine the magnitude of the pressure across multiple levels in the second detection process.

[0016] According to this technology, because the surface layer is configured to be thicker than the deformable layer, the pressure sensitivity can be sufficiently higher than the touch sensitivity. Therefore, the pressure sensing function can be divided into multiple levels.

[0017] The surface layer typically has a thickness two or more times that of the deformable layer.

[0018] The surface layer may be made of a material with an elastic modulus higher than that of the deformable layer.

[0019] The sensor chip may include

[0020] Flexible substrate, and

[0021] A sensor electrode layer, comprising a plurality of capacitive elements arranged in a matrix on a surface of one side of the substrate, and

[0022] Each of the plurality of capacitive elements may include a pair of comb-shaped electrodes facing each other in a direction parallel to one side of the substrate.

[0023] The sensor electrode layer can be disposed on the surface of the sensor sheet, the surface facing the reference electrode layer.

[0024] The sensor device may further include a support layer.

[0025] The support layer is disposed between the mounting surface on which the sensor device is mounted and the reference electrode layer, and the support layer is made of a flexible material.

[0026] The surface layer may include

[0027] The outer portion forming the input operation surface, and

[0028] The inner layer is disposed between the outer layer and the sensor sheet, and has an elastic modulus different from that of the outer layer.

[0029] The deformable layer may include

[0030] The first deformable layer disposed on one side surface of the sensor sheet, and

[0031] A second deformable layer is disposed between the first deformable layer and the reference electrode layer, and has an elastic modulus different from that of the first deformable layer.

[0032] The surface layer may include

[0033] The flat plate portion forming the input operation surface, and

[0034] The legs are positioned on the periphery of the flat plate portion and supported by a mounting surface on which the sensor device is mounted.

[0035] The control unit may include a determining portion that determines which segment among a plurality of segments defined according to the plurality of thresholds the pressing pressure belongs to.

[0036] The plurality of thresholds may include

[0037] The first pressure sensitivity is two or more times the touch sensitivity, which is the detection sensitivity of the sensor sheet, and the touch sensitivity is measured when the object being detected is in contact with the input operation surface.

[0038] The second pressure sensitivity is three times or more the same as the touch sensitivity.

[0039] The plurality of thresholds may further include a third pressure sensitivity, which is four or more times the touch sensitivity.

[0040] The control unit may further include a threshold setting section, which is capable of individually adjusting the plurality of thresholds.

[0041] The threshold setting section can adjust the first pressure sensitivity and the second pressure sensitivity according to the area of ​​the operation performed by the detected object on the input operation surface.

[0042] An electronic device according to another embodiment of the present technology includes a sensor device.

[0043] The sensor device includes: a sensor chip; a reference electrode layer; a deformation layer; a surface layer; and a control unit.

[0044] The sensor chip is configured to detect the distribution of pressure.

[0045] The reference electrode layer is arranged on one side of the sensor sheet and connected to a reference potential.

[0046] The deformable layer is disposed between the sensor sheet and the reference electrode layer and is made of a flexible material.

[0047] The surface layer has an input operation surface, which is disposed on the surface on the other side of the sensor sheet, and is made of a non-conductive material that is thicker than the deformable layer.

[0048] The control unit is capable of performing a first detection process based on the output from the sensor chip to detect the contact between the object being detected and the input operating surface, and a second detection process to detect the pressure applied by the object being detected to the input operating surface. The control unit sets multiple thresholds to determine the magnitude of the pressure across multiple levels in the second detection process. Attached Figure Description

[0049] [ Figure 1 The illustration shows a schematic cross-sectional side view of the configuration of a sensor device according to an embodiment of the present technology.

[0050] [ Figure 2 This illustration shows a schematic plan view of an example configuration of sensor chips in a sensor device.

[0051] [ Figure 3 The illustration shows a schematic plan view of an example configuration of the sensing portion in a sensor chip.

[0052] [ Figure 4 The illustration shows a schematic cross-sectional side view of another configuration example of the sensor device.

[0053] [ Figure 5 This illustration shows a schematic cross-sectional side view of yet another configuration example of a sensor device.

[0054] [ Figure 6 The illustration shows a schematic cross-sectional side view of another configuration example of the sensor device.

[0055] [ Figure 7 The illustration shows a schematic cross-sectional side view of another configuration example of the sensor device.

[0056] [ Figure 8 A functional block diagram of the control unit that constitutes the sensor device.

[0057] [ Figure 9 An illustrative graph showing an example of the relationship between touch sensitivity and pressure sensitivity is provided.

[0058] [ Figure 10 This illustrates another relationship between touch sensitivity and pressure sensitivity to be set for a sensor device.

[0059] [ Figure 11 Experimental results on the dependence of surface layer thickness on displacement sensitivity.

[0060] [ Figure 12 Experimental results on the dependence of surface layer structure (thickness and flexibility) on load sensitivity.

[0061] [ Figure 13 Load-displacement curve when the input operating surface of the sensor device is pressed.

[0062] [ Figure 14 The graph shows the relationship between displacement and the maximum sensitivity of the sensor device.

[0063] [ Figure 15 The diagram illustrates the operating area on the input operating surface.

[0064] [ Figure 16 The diagram shows examples of load-displacement curves in the operating area.

[0065] [ Figure 17 This shows a lookup table illustrating the various relationships between the operating region and the correction factor.

[0066] [ Figure 18 [Illustrated] Figure 1 An explanatory diagram showing the thickness of the deformable layer and the surface layer of the sensor device.

[0067] [ Figure 19 This represents the simulation results showing the relationship between the thickness ratio of the deformed layer and the surface layer and the maximum deformation rate of the deformed layer. Detailed Implementation

[0068] In the following description, embodiments of the present technology are illustrated with reference to the accompanying drawings.

[0069] Figure 1 This is a schematic cross-sectional side view illustrating the configuration of a sensor device 100 according to an embodiment of the present technology. Figure 2 This is a schematic plan view illustrating an example configuration of sensor chip 10 in sensor device 100.

[0070] exist Figure 1 and Figure 2 In the diagram, the X-axis and Y-axis directions are parallel to the input operation surface S (hereinafter referred to as in-plane directions), and the Z-axis direction is perpendicular to the input operation surface S (hereinafter referred to as the perpendicular direction). Furthermore, in... Figure 1 In the middle, the upper side corresponds to the front side where the external force is applied, and the lower side corresponds to the rear side opposite to it.

[0071] [Overall configuration of sensor equipment]

[0072] The sensor device 100 has a planar shape that is essentially a rectangular flat plate structure. The planar shape of the sensor device 100 is not particularly limited, as long as it is appropriately oriented to correspond to the shape of the location where the sensor device 100 is positioned. For example, the planar shape of the sensor device 100 can be a polygonal shape other than a quadrilateral, circle, ellipse, etc.

[0073] like Figure 1 As shown, the sensor device 100 includes a pressure sensor 1 and a control unit 60. The pressure sensor 1 is composed of a stack including a sensor sheet 10, a reference electrode layer 20, a deformable layer 30, and a surface layer 40.

[0074] The sensor device 100 is configured as an input device, for example, installed in an electronic device. Examples of electronic devices include not only information processing devices (such as tablet PCs) and audio devices (such as headphones and in-ear headphones), but also imaging devices (digital cameras and camcorders) and gaming devices.

[0075] (Sensor chip)

[0076] The sensor chip 10 is made of, for example, a flexible printed circuit board including a substrate 11 and a sensor electrode layer 12. The sensor electrode layer 12 includes a plurality of capacitive elements (sensing portions 13) arranged in a matrix on the rear surface of the substrate 11, the rear surface facing the reference electrode layer 20 and configured to detect the distribution of pressure applied to the input operating surface S.

[0077] like Figure 2 As shown, the substrate 11 includes a main body portion 111 having a rectangular planar shape, and an extension portion 112 extending outward from the periphery of the edge of the main body portion 111. Note that the planar shape of the substrate 11 is not limited to a rectangle and can be of any shape. The material of the substrate 11 is not particularly limited, as long as the material is a flexible insulating material, and a polymer resin such as polyethylene terephthalate, polyimide, polycarbonate, and acrylic resin is used.

[0078] The sensing section 13 corresponds to the nodes of the sensor patch 10 and is arranged in a uniform matrix with predetermined vertical and horizontal intervals (vertical: Y-axis direction, horizontal: X-axis direction). Figure 2 In the example shown, the number of sensing elements 13 (number of nodes) is 9×9 (vertical×horizontal), that is, a total of 81. Note that the number of sensing elements 13 can be varied appropriately. The sensing elements 13 are composed of capacitive elements (detection elements) capable of detecting changes in distance from the reference electrode layer 20 as changes in capacitance.

[0079] Figure 3This is a schematic plan view illustrating an example configuration of the sensing section 13. The sensing section 13 has a direction including the rear surface parallel to the substrate 11. Figure 3 An electrode pair consisting of a comb-shaped pulse electrode 281 and a comb-shaped sensing electrode 282 facing each other in the Y-axis direction. The pulse electrode 281 and the sensing electrode 282 are arranged such that their respective comb teeth face each other. Each sensing part 28 is composed of a region (node ​​region) in which the comb teeth on the other side are arranged to enter the gap between the comb teeth on one side.

[0080] Each pulse electrode 281 is connected to a wiring portion 281a extending in the Y-axis direction, and each sensing electrode 282 is connected to a wiring portion 282a extending in the X-axis direction. The wiring portions 281a are arranged along the X-axis direction on the rear surface of the substrate 11, and the wiring portions 282a are arranged along the Y-axis direction on the front surface of the substrate 11. The sensing electrodes 282 are electrically connected to the wiring portions 282a via through-holes 283 disposed through the substrate 29.

[0081] Alternatively, both wiring portions 281a and 282a can be formed on the rear surface of the substrate 11, and their intersections can be isolated from each other, for example, using jumper components. When the pulse electrode 281 (wiring portion 281a) and the sensing electrode 282a (wiring portion 282a) are formed on the rear surface of the substrate 11 (the surface facing the reference electrode layer 20), the distance between each of electrodes 281 and 282 and the input operating surface S increases the thickness of the substrate 11. Therefore, touch sensitivity can be suppressed to a lower level relative to pressure sensitivity. Note that touch sensitivity and pressure sensitivity are described below.

[0082] The sensor electrode layer 30 may include a ground wire. The ground wire is disposed, for example, in the peripheral portion of the sensor electrode layer 12 or in the portion of the wiring portions 281a and 282a that extends along the ground wire.

[0083] Note that the sensing portion 13 does not necessarily need to be constructed as in the example described above, and can adopt any construction. For example, the sensor electrode layer 12 can be composed of a stack of a first electrode sheet having a grid-like first electrode pattern extending in the X-axis direction and a second electrode sheet having a grid-like second electrode pattern extending in the Y-axis direction. In this case, the sensing portion 13 is formed at the intersection of the first electrode pattern and the second electrode pattern.

[0084] (Reference electrode layer)

[0085] The reference electrode layer 20 is arranged as a surface (back surface) facing the sensor sheet 10. The reference electrode layer 20 is connected to a reference potential. In this embodiment, the reference electrode layer 20 is a so-called ground electrode and is connected to a ground potential, which serves as the reference potential. The reference electrode layer 20 is flexible and has a thickness of, for example, approximately 0.05 mm to 0.5 mm. Examples of materials that can be used for the reference electrode layer 20 include inorganic conductive materials, organic conductive materials, and conductive materials comprising both inorganic and organic conductive materials.

[0086] Examples of inorganic conductive materials include metals (such as aluminum, copper, and silver), alloys (such as stainless steel), and metal oxides (such as zinc oxide and indium oxide). Furthermore, examples of organic conductive materials include carbon materials (such as carbon black and carbon fibers), and conductive polymers (such as substituted or unsubstituted polyaniline and polypyrrole). The reference electrode layer 20 may be composed of, for example, a thin metal sheet (such as stainless steel or aluminum), or conductive fibers or conductive nonwoven fabric. The reference electrode layer 20 may be formed on a plastic film, for example, by methods such as deposition, sputtering, bonding, or coating.

[0087] (Deformation layer)

[0088] A deformable layer 30 is disposed between the sensor sheet 10 and the reference electrode layer 20. The deformable layer 30 has a thickness of, for example, about 100 μm to 1000 μm, and in this embodiment, 500 μm or less.

[0089] The lower limit of the thickness of the deformable layer 30 is not particularly limited, as long as the thickness is greater than 100 μm. This lower limit can be, for example, 150 μm or greater, 200 μm or greater, 250 μm or greater, 300 μm or greater, etc. Meanwhile, the upper limit of the thickness of the deformable layer 30 is not particularly limited, as long as the thickness is 1000 μm or less. This upper limit can be, for example, 950 μm or greater, 900 μm or less, 850 μm or less, 800 μm or less, etc.

[0090] The deformable layer 30 has, for example, 50 mg / cm³. 2 Or even smaller mass per unit area. When the thickness and mass per unit area of ​​the deformable layer 30 are set within these ranges, the detection sensitivity of the pressure sensor 100 in the vertical direction can be enhanced.

[0091] The deformable layer 30 is made of a flexible material capable of elastic deformation in response to external forces, such as foam (elastic foam), rubber, gel, nonwoven fabric, nanofibers, etc. When an external force is applied to the sensor sheet 10 in the vertical direction, the deformable layer 30 elastically deforms in response to the external force, bringing the reference electrode layer 20 closer to the sensor electrode layer 12. At this time, a change in capacitance occurs between the pulse electrode 281 and the sensing electrode 282 in the sensing section 13. Therefore, the sensing section 13 can detect the capacitance change as a pressure value.

[0092] To facilitate deformation in the Z-axis direction, the deformation layer 30 can be composed of a patterned structure, for example, including columnar structures. Such a patterned structure can take various forms, such as matrix, strip, mesh, radial, geometric, or spiral structures.

[0093] The deformable layer 30 is applied to the sensor sheet 10 and the reference electrode layer 20 via a bonding material. Examples of bonding materials that can be used include one or more adhesives selected from the group consisting of acrylic adhesives, silicone adhesives, polyurethane adhesives, etc.

[0094] The deformable layer 30 can be a laminated structure comprising multiple materials with different elastic moduli (hardness) to each other. Figure 4 It is a schematic cross-sectional side view of a sensor device 101 including a deformable layer 30 consisting of a stacked structure including a first deformable layer 31 and a second deformable layer 32.

[0095] A first deformable layer 31 is disposed on the rear surface of the sensor sheet 10. A second deformable layer 32 is disposed between the first deformable layer 31 and the reference electrode layer 20, and has an elastic modulus different from that of the first deformable layer 31. The first deformable layer 31 may be made of a material with an elastic modulus higher than that of the second deformable layer 32, or it may be made of a material with an elastic modulus lower than that of the second deformable layer 32. The thicknesses of the first deformable layer 31 and the second deformable layer 32 are not particularly limited, and they may be formed to have the same thickness as each other, or they may be formed to have different thicknesses than each other.

[0096] When the deformable layer 30 is composed of a stack of flexible materials with different hardnesses, the threshold of pressure sensitivity can be set by utilizing the capacitance change (load sensitivity) of the sensing portion 13 in response to the deformation of the first deformable layer 31 and the capacitance change (load sensitivity) of the sensing portion 13 in response to the deformation of the second deformable layer 32.

[0097] (Surface layer)

[0098] The surface layer 40 serves as the outer layer of the sensor device 100 and has an input operation surface S to be operated by the user. Furthermore, the input operation surface S serves as a detection surface that contacts a detection object (e.g., a user's finger) of the sensor device 100 and detects touch and press operations of the detection object on the sensor device 100.

[0099] A surface layer 40 is disposed on the surface of the other side (front surface) of the sensor sheet 10. The surface layer 40 is made of a non-conductive material. Examples of non-conductive materials include electrically insulating materials such as synthetic resins, rubber, foam plastics (elastic foam), and non-woven fabrics. Note that when the entire surface layer 40 is electrically insulating, a composite material obtained, for example, by mixing conductive particles (such as metal particles or metal sheets) into a synthetic resin material can be used.

[0100] The surface layer 40 is not particularly limited, as long as a touch operation on the input operation surface S can be detected. In this embodiment, the surface layer 40 has a thickness greater than that of the deformable layer 30 (e.g., two to three times the thickness of the deformable layer 30). This allows the pressure sensitivity when the detected object presses on the input operation surface S to be higher than the touch sensitivity when the detected object touches the input operation surface S. Here, touch sensitivity corresponds to the capacitance change of the sensing portion 13 when the detected object touches the input operation surface S, and pressure sensitivity corresponds to the capacitance change of the sensing portion 13 when the detected object presses on the input operation surface S.

[0101] The thickness of surface layer 40 is expected to be two times or more than the thickness of deformable layer 30. As described below, this allows for pressure sensitivity that is sufficiently higher than touch sensitivity, and pressure sensing functionality can be easily divided into multiple levels.

[0102] The surface layer 40 can be made of a material with a higher elastic modulus than the deformable layer 30. In other words, when the surface layer 40 is made of a material that is harder than the deformable layer 30, the functions of detecting touch operations and detecting press operations can be easily distinguished from each other. This can suppress malfunctions.

[0103] The surface layer 40 can be a laminated structure of multiple materials with different elastic moduli (hardness) to each other. Figure 5 This is a schematic cross-sectional side view of a sensor device 102 including a surface layer 40 having an outer layer portion 41 and an inner layer portion 42. The outer layer portion 41 forms an input operating surface S. The inner layer portion 42 is disposed between the outer layer portion 41 and the sensor sheet 10, and has an elastic modulus different from that of the outer layer portion 41.

[0104] The outer layer 41 can be made of a material with a higher elastic modulus than the inner layer 42, or it can be made of a material with a lower elastic modulus than the inner layer 42. For example, when the outer layer 41 is formed to be thicker than the inner layer 42, the thicker outer layer 41 is made of a material with a lower elastic modulus than the inner layer 42 (a soft material). Conversely, when the outer layer 41 is formed to be thinner than the inner layer, the thinner outer layer 41 is made of a material with a higher elastic modulus than the inner layer 42 (a hard material). Examples of soft materials to be used include flexible materials (such as gels, rubber, elastomers, and elastic foams). Examples of hard materials to be used include plastic materials (such as acrylic).

[0105] The surface layer 40 may be part of the housing of the electronic device on which the sensor device 100 is mounted. In this case, the sensor device 40 is mounted in the housing of the electronic device, and the surface of the housing serves as the input operating surface S. The housing is made of, for example, a translucent or opaque plastic material.

[0106] Figure 6 This is a schematic cross-sectional side view of a sensor device 103, where the surface layer 40 is part of the housing of an electronic device. As shown, in the sensor device 103, the surface layer 40 includes a flat plate portion 401 forming an input operation surface S, and legs 402 disposed on the periphery of the flat plate portion 401. The flat plate portion 401 is a non-conductive layer configured to face the front surface of the sensor sheet 10, corresponding to… Figure 1 The surface layer 40 in the middle. The legs 402 protrude downward from the outer periphery of the flat plate portion 401 to the mounting surface T of the sensor device 103, and their end portions are supported by the mounting surface T.

[0107] In the sensor device 103 configured as described above, the flat plate portion 401 elastically deforms while being supported by the leg portion 402. Consequently, a pressing operation on the input operation surface S is input to the sensor plate 10. This allows the pressing force to be detected based on the capacitance change of the sensing layer 13 in response to the deformation of the deformation layer 30.

[0108] The pressure sensitivity of the sensor device 103 can be adjusted by the elastic modulus of the plate portion 401 or by the elastic modulus of the leg portion 402. In this case, the plate portion 401 and the leg portion 402 can be made of materials with different elastic moduli, or the leg portion 402 can be made of a stack of non-conductive materials with different elastic moduli.

[0109] (Support layer)

[0110] like Figure 1As shown, the sensor device 100 also includes a support layer 50. The support layer 50 is disposed between the mounting surface T on which the sensor device 100 is mounted and the reference electrode layer 20. The support layer 50 is made of an electrically insulating adhesive material or an electrically insulating pressure-sensitive adhesive material, and serves as a bonding layer for fixing the reference electrode layer 20 to the mounting surface T.

[0111] The support layer 50 can be made of a flexible material. In this case, for example, the surface layer 40 is configured as... Figure 4 In the case of the housing of the illustrated electronic device, the touch sensitivity or initial capacitance of the sensing portion 13 of the sensor device 101 mounted on the mounting surface T is easily adjustable. In other words, dimensional tolerances in the distance between the flat portion 401 of the surface layer 40 and the mounting surface T, as well as variations in the thickness of the sensor device 101, can be absorbed by the support layer 50. This allows the initial capacitance or touch sensitivity in the sensing portion 13 to be stably set to its target capacitance value.

[0112] The support layer 50 can be a laminated structure comprising multiple materials with different elastic moduli (hardness) to each other. Figure 7 It is a schematic cross-sectional side view of a sensor device 104 including a support layer 50 consisting of a stacked structure including a first support layer 51 and a second support layer 52.

[0113] A first support layer 51 is disposed on the rear surface of the reference electrode layer 20. A second support layer 52 is disposed between the first support layer 51 and the mounting surface T, and has an elastic modulus different from that of the first support layer 51. The first support layer 51 may be made of a material with an elastic modulus higher than that of the second support layer 52, or it may be made of a material with an elastic modulus lower than that of the second support layer 52. The thicknesses of the first support layer 51 and the second support layer 52 are not particularly limited, and they may be formed to have the same thickness or to have different thicknesses.

[0114] When the support layer 50 is composed of a stack of flexible materials with varying hardness, similar functionality and advantages as when the support layer 50 is a single layer can be achieved. Furthermore, robustness in responding to pressure input on the input operation surface S can be enhanced.

[0115] (Control unit)

[0116] The control unit 60 is typically a computer including a CPU (central processing unit) and is composed of integrated circuits such as IC chips. The control unit 60 is attached to the sensor chip 10 (its lead-out portion 112) and is configured to drive the pressure sensor 1 and receive output signals from the pressure sensor 1.

[0117] Figure 8This is a functional block diagram of the control unit 60. The control unit 60 includes an arithmetic section 61, a determination section 62, and a threshold setting section 63.

[0118] The calculation unit 61 calculates the capacitance change of each sensing portion 13 on the sensor chip 10 based on the output from the pressure sensor 1. The determination unit 62 determines which segment among multiple segments defined according to multiple preset thresholds the capacitance change belongs to, and outputs the determination result to the control device 71 of the electronic device 70 on which the sensor devices 100 to 104 are installed. The threshold setting unit 63 sets the multiple thresholds. Note that the control unit 60 may be configured as part of the control device 71 of the electronic device 70.

[0119] As described above, electronic device 70 is configured as an input device to be installed in an electronic device. Examples of electronic devices include not only information processing devices (such as tablet PCs) and audio devices (such as headphones and in-ear headphones), but also imaging devices (such as digital cameras and camcorders) and gaming devices.

[0120] The control unit 60 is capable of performing a first detection process, which detects contact between the object being tested and the input operating surface S, and a second detection process, which detects the pressure applied by the object being tested to the input operating surface S, based on the output from the pressure sensor 1 (sensor plate 10). In the second detection process, the control unit 60 sets multiple thresholds for determining the magnitude of the pressure across multiple levels.

[0121] While the assignment of tapping operations on a conventional touch sensor is limited to one type, the sensor device according to this embodiment, which has both touch and pressure sensing capabilities, allows assignment to four different types, such as touch, low pressure, medium pressure, and high pressure. As a specific example of use, for instance, when the electronic device 70 is an audio device, although a touch sensor only allows power on / off via tapping, in this embodiment, the touch sensor not only allows power on / off but also allows, for example, slightly increasing / decreasing volume, moderately increasing / decreasing volume, and drastically increasing / decreasing volume.

[0122] Other examples of operations include track selection (fast forward, skip track, skip album). Other examples include zoom level in a camera, multi-level detection of controller intensity in gaming devices, and brightness adjustment of lights or display screens in mobile information terminals.

[0123] To assign operations at multiple levels via touch and pressure sensing, the touch sensitivity when the input surface S is touched by a finger needs to be sufficiently higher than the pressure sensitivity when the input surface S is pressed by a finger. To assign an operation via each of touch sensitivity and pressure sensitivity (two in total), such as... Figure 9 As shown, threshold Th1 is set for the touch sensitivity region and threshold Th2 is set for the pressure sensitivity region. Figure 9 In the diagram, the horizontal axis represents the displacement of the finger being detected, the vertical axis represents the maximum sensitivity among all nodes, and "0" on the horizontal axis corresponds to the position where the detected object contacts the input operation surface S.

[0124] Thresholds Th1 and Th2 need to be set to values ​​that are far apart from each other. To avoid false alarms (malfunctions), threshold Th2 is expected to be two or more times that of threshold Th1 (Th2 ≥ 2·Th1). To assign a greater number of operation levels, multiple thresholds need to be set for the sensitivity area since only one threshold can be set for the sensitivity area.

[0125] For example, to assign four operations, such as Figure 10 As shown, a threshold Th1 (touch sensitivity) is set for the touch area, and three thresholds are set for the pressure sensing area: Th2 (first pressure sensitivity), Th3 (second pressure sensitivity), and Th4 (third pressure sensitivity). In this case, it is desirable that Th2 ≥ 2·Th1, Th3 ≥ 3·Th1, and Th4 ≥ 4·Th1 are all satisfied. When setting multiple thresholds under these conditions, the sensor structure needs to allow the pressure sensitivity to be sufficiently higher than the touch sensitivity.

[0126] Now, let's describe displacement sensitivity. Displacement sensitivity refers to the relationship between the amount of displacement of the detected object (e.g., a user's finger) relative to the input operating surface S and the detection sensitivity. Figure 11 Experimental results showing the dependence of the thickness of surface layer 40 on displacement sensitivity are presented. In this figure, the sensitivity at a displacement of 0 corresponds to touch sensitivity, and the region where the displacement is positive (positive sign) corresponds to pressure sensitivity. The material of surface layer 40 is a single layer of acrylic sheet.

[0127] exist Figure 11In the diagram, A1 represents the displacement sensitivity when the thickness of the surface layer 40 is the same as the thickness of the deformed layer 30 (0.5 mm), and A2 represents the displacement sensitivity when the thickness of the surface layer 40 is three times the thickness of the deformed layer 30 (1.5 mm). In case A1, the touch sensitivity is high, therefore the pressure sensitivity threshold is high. Thus, the touch function and the pressure sensing function are difficult to distinguish from each other. Conversely, in case A2, the touch sensitivity can be reduced, so the pressure sensitivity threshold can be set sufficiently higher than the touch sensitivity threshold. Therefore, the touch function and the pressure sensing function are easily distinguishable from each other, and multiple levels of thresholds can be set for the pressure sensing area.

[0128] Next, we will describe the load sensitivity. Load sensitivity refers to the relationship between the vertical load applied to the input operating surface S and the detection sensitivity. Figure 12 Experimental results show the dependence of the structure (thickness and flexibility) of surface layer 40 on load sensitivity.

[0129] exist Figure 12 In this context, B1 represents the load sensitivity when the thickness of the surface layer 40 is the same as the thickness of the deformed layer 30 (0.5 mm), and B2 represents the load sensitivity when the surface layer 40 has... Figure 5 The load sensitivity is shown in the case of the laminated structure, where the outer layer 41 is a 0.5 mm thick acrylic sheet and the inner layer 42 is a 1.0 mm thick rubber sheet. Note that the same load sensitivity is also obtained when the outer layer 41 is a 1.0 mm thick rubber sheet and the inner layer 42 is a 0.5 mm thick acrylic sheet. Furthermore, B3 indicates the load sensitivity when the surface layer 40 is an acrylic sheet with a thickness three times that of the deformable layer 30 (1.5 mm).

[0130] like Figure 12 As shown, the load sensitivity tends to decrease in the order of B1, B2, and B3. This is because the surface layer 40 becomes harder as its thickness increases. Therefore, to suppress the decrease in load sensitivity, the surface layer 40 needs to be soft. When the surface layer 40 is soft, it is also related to the load sensitivity, making touch and pressure sensing functions easier to distinguish from each other.

[0131] In the sensor device 100 according to this embodiment, as described above, the surface layer 40 is formed to be thicker than the deformable layer 30. Therefore, as described above, compared to the case where the surface layer 40 and the deformable layer 30 have the same thickness, the pressure sensitivity can be sufficiently higher than the touch sensitivity. Therefore, the pressure sensing function can be divided into multiple levels.

[0132] (Threshold setting method 1)

[0133] Next, a specific example of a method for setting a threshold is described. Here, a description is given using a sensor device 104 including a surface layer 40 with legs 402 (see reference). Figure 7 The process of setting fixed thresholds (1.5 N and 3 N load) in the threshold setting section 63.

[0134] First, the load, displacement, and maximum sensitivity at all nodes of the pressure sensor 1 are measured when the input operating surface S of the sensor device 104 is pressed. An aluminum pressing tool with a diameter of 10 mm, close to the size of a finger, is used. The deformation of the pressure sensor 1 in the Z-axis direction is measured until the load reaches 5 N from 5 mm above the center position of the input operating surface S, which is the upper surface of the surface layer 40.

[0135] Figure 13 The load-displacement curve is shown when the input operating surface S is pressed, and Figure 14 The relationship between displacement and maximum sensitivity is shown. Note that in Figure 14 In the middle, the displacement is -5 mm at the beginning position and 0 mm when the load is first detected.

[0136] Then, the displacement Z1 when the load is 1.5 N and the displacement Z2 when the load is 3 N are measured (reference). Figure 13 Furthermore, the maximum sensitivity (hereinafter referred to simply as sensitivity) was measured when the displacement was 0, Z1, and Z2 (see reference). Figure 14 ).

[0137] Next, in the threshold setting section 63, the sensitivity (touch sensitivity) is set to threshold Th1 when the displacement is 0, the sensitivity is set to threshold Th2 (first pressure sensitivity) when the load is 1.5 N, and the sensitivity is set to Th3 (second pressure sensitivity) when the load is 3 N. From the viewpoint of suppressing false alarms, as mentioned above, it is desirable to satisfy Th2 ≥ 2·Th1 and Th3 ≥ 3·Th1.

[0138] For example, the determination process in part 62 is performed based on sensitivity through the following procedure:

[0139] • Operation 1: When the sensitivity is Th1 or higher and remains no more than Th2 for a certain period of time (e.g., 0.5 seconds).

[0140] • Operation 2: When the sensitivity is Th2 or higher and remains no more than Th3 for a certain period of time (e.g., 0.5 seconds).

[0141] • Operation 3: When the sensitivity is Th3 or higher and remains at Th3 or higher for a certain period of time (e.g., 0.5 seconds).

[0142] (Threshold setting method 2)

[0143] The thresholds set in threshold setting section 63 can be individually configured to be variable for each user. This allows the thresholds to be optimized for each user, thus enhancing operability for each user. The process for this setting is as follows.

[0144] When the user performs an operation on the touch input surface S (touch operation), the maximum sensitivity measurement (hereinafter also referred to as sensitivity measurement) of all nodes of the pressure sensor 1 is performed three times, and the average value is set as threshold Th1 in threshold setting section 63. Next, when the user performs an operation on the light pressure input surface S (pressure amount: small), the sensitivity measurement is performed three times, and the average value is set as threshold Th2 in threshold setting section 63. Subsequently, when the user performs an operation on the heavy pressure input surface S (pressure amount: large), the sensitivity measurement is performed three times, and the average value is set as threshold Th3 in threshold setting section 63.

[0145] In the same scenario, from the perspective of suppressing false alarms, the expected thresholds Th2 and Th3 are set to satisfy Th2 ≥ 2·Th1 and Th3 ≥ 3·Th1. When these conditions are not met, a similar measurement (calibration) can be performed again.

[0146] As described above, the determination section 62 performs the determination process based on sensitivity, for example, through the following procedure.

[0147] • Operation 1: When the sensitivity is Th1 or higher and remains no more than Th2 for a certain period of time (e.g., 0.5 seconds).

[0148] • Operation 2: When the sensitivity is Th2 or higher and remains no more than Th3 for a certain period of time (e.g., 0.5 seconds).

[0149] • Operation 3: When the sensitivity is Th3 or higher and remains at Th3 or higher for a certain period of time (e.g., 0.5 seconds).

[0150] (Threshold setting method 3)

[0151] The magnitude of the load to be detected by pressure sensor 1 can vary depending on the position of the operation on the input operating surface S. For example, in Figure 7 In the sensor device 104 shown, since the legs 402 of the surface layer 40 are supported by the mounting surface T, the detection sensitivity is prone to differ between the center position of the input operating surface S and the peripheral position near the legs 402 (see reference). Figure 15 and Figure 16Therefore, in this embodiment, the threshold setting portion 63 is configured to correct the pressure sensitivity based on the area of ​​the operation performed by the detected object on the input operation surface S.

[0152] Figure 15 This is a schematic diagram illustrating the operating area on the input operating surface S, and Figure 16 The load-displacement curves for each operating region are shown. For example... Figure 16 As shown, in the sensor device 104 including the surface layer 40 with legs 402, even under the same vertical load, the displacement in the operating regions S2 and S3 of the peripheral portion of the input operating surface S tends to be less than the displacement in the operating region S1 at the center of the input operating surface S, and therefore the detection sensitivity tends to be lower. Therefore, in order to obtain uniform detection sensitivity in each of the operating regions S1 to S3, the threshold setting section 63 sets a threshold through the following process.

[0153] First, the relationship between load and displacement is measured when the operating areas S1 to S3 on the input operating surface S of the sensor device 104 are pressed. Figure 16 An aluminum pressure tool with a diameter of 10 mm, close to the size of a finger, is used. The slopes of the measured load-displacement curves for the operating areas S1 to S3 are then calculated, and these slopes are used as correction coefficients. Based on these correction coefficients, the threshold setting section 63 corrects, for example, the first pressure sensitivity (Th2) and the second pressure sensitivity (Th3) according to the area of ​​the operation performed by the detected object on the input operating surface S.

[0154] The operating area is divided into nine regions. Operating area S1 corresponds to the center of the input operating surface S, operating area S2 corresponds to the area between the center of each side of the input operating surface S and operating area S1, and operating area S3 corresponds to the areas at the four corners of the input operating surface S. For example, ... Figure 17 The lookup tables shown represent the calculated correction coefficients for operation areas S1 to S3. In the example shown, nine area numbers are assigned to the divided operation areas, with a correction coefficient of 0.5 for area numbers 1 and 3, 0.7 for area numbers 2 and 8, 0.8 for area numbers 4 and 6, 1 for area number 5, and 0.6 for area numbers 7 and 9.

[0155] The position of contact between the detected object and the input operation surface S is calculated based on the centroid position of the pressure distribution applied to pressure sensor 1 (sensor piece 10). The corrected pressure sensitivity (threshold) is obtained by multiplying the uncorrected pressure sensitivity (threshold) by the aforementioned correction coefficients assigned to each region. For example, when a press operation is detected in region 1, the press force is determined using the corrected thresholds (Th2' and Th3') obtained by multiplying the uncorrected pressure sensitivities (Th2 and Th3) by 0.5. When a press operation is detected in region 6, the press force is determined using the corrected thresholds (Th2' and Th3') obtained by multiplying the uncorrected thresholds (Th2 and Th3) by 0.8. This reliably ensures that the input operation matches the user's intention without compromising the user's sense of operation.

[0156] Note that when the material or thickness of surface layer 40 varies by region, a similar technique to the one described above can be used to correct the touch sensitivity Th1. For example, when the correction factor for the region with the smallest thickness of surface layer 40 is set to 1, the correction factor for other regions with larger thicknesses is set to less than 1. Conversely, when the correction factor for the region with the largest thickness of surface layer 40 is set to 1, the correction factor for other regions with smaller thicknesses is set to greater than 1.

[0157] (The relationship between touch sensitivity and pressure sensitivity)

[0158] Next, by using Figure 1 The example of sensor device 100 shown illustrates why the desired pressure sensitivity Th2 is set to be two or more times the touch sensitivity Th1.

[0159] like Figure 18 As shown, the thickness of the deformable layer 30 is represented by d, and the thickness of the surface layer 40 is represented by D. When the entire sensor sheet 10 is considered as an electrode (sensor electrode layer 13), the touch sensitivity C1 when the detected object contacts the input operation surface S is expressed by the following formula.

[0160] C1=εA / D ... (1)

[0161] Where ε is the dielectric constant of surface layer 40, and A is the area of ​​contact between the detected object and the sensor plate 10. Equation (1) corresponds to the change in capacitance between the detected object and the sensor plate 10 when the detected object moves from a point significantly away from the sensor plate 10 to a distance D (the position of the input operation surface S).

[0162] When the deformable layer 30 is deformed by x%, and when the dielectric constant of the deformable layer 30 is the same as the dielectric constant (ε) of the surface layer 40, the pressure sensitivity C2 is expressed by the following formula.

[0163] C2=εA / {d(1-x / 100)}-εA / d... (2)

[0164] Equation (2) corresponds to the capacitance change when the sensor sheet 10 moves closer to the reference electrode layer 20 from a distance d to a distance d(1-x / 100).

[0165] When the setting of touch sensitivity × 2 < maximum pressure sensitivity is applied to the thresholds for setting touch sensitivity and pressure sensitivity,

[0166] (εA / D)×2<εA / {d(1-x / 100)}-εA / d

[0167] 2 / D<1 / {d(1-x / 100)}-1 / d=x / d(100-x)

[0168] ∴ D / d>2(100-x) / x... (3)

[0169] Figure 19 The function represented by equation (3) is shown.

[0170] The deformable layer 30 does not need to be deformed 100%, therefore the deformation rate of the deformable layer 30 is limited. For example, when a foam matrix is ​​used as the deformable layer 30, the volume fraction of the material constituting the foam matrix is ​​typically 20% or greater. Furthermore, materials generally have a thickness variation of ±10%, therefore a maximum variation of approximately 20% in the thickness of the deformable layer 30 needs to be allowed. Additionally, considering the integration of the sensor device 100 into the housing of the electronic device, a mechanical variation (tolerance) of approximately 10% in the housing needs to be allowed.

[0171] Considering the three factors mentioned above, the maximum deformation rate of the deformable layer 30 within its actual application range is 50% or less. Therefore, as... Figure 19 As shown, it can be said that the expected value of D / d (thickness D of surface layer 40) ÷ (thickness d of deformable layer 30) is 2 or greater.

[0172] Note that this technology can also be configured as follows.

[0173] (1) A sensor device, comprising:

[0174] A sensor chip capable of detecting pressure distribution;

[0175] A reference electrode layer, wherein the reference electrode layer is arranged on a surface facing the side of the sensor chip and is connected to a reference potential;

[0176] A deformable layer is disposed between the sensor sheet and the reference electrode layer and is made of a flexible material;

[0177] A surface layer having an input operation surface is disposed on the surface of the sensor sheet on the other side and is composed of a non-conductive material thicker than the deformable layer; and

[0178] The control unit is capable of performing a first detection process, which detects contact between a detection object and an input operating surface, and a second detection process, which detects the pressure applied by the detection object to the input operating surface, based on the output from the sensor chip. The control unit sets multiple thresholds to determine the magnitude of the pressure across multiple levels in the second detection process.

[0179] (2) The sensor device according to (1), wherein

[0180] The surface layer has a thickness that is two or more times that of the deformable layer.

[0181] (3) The sensor device according to (2), wherein

[0182] The surface layer is made of a material with an elastic modulus higher than that of the deformable layer.

[0183] (4) The sensor device according to (2) or (3), wherein

[0184] The sensor chip includes

[0185] Flexible substrate, and

[0186] A sensor electrode layer, comprising a plurality of capacitive elements arranged in a matrix on a surface of one side of the substrate, and

[0187] Each of the plurality of capacitive elements includes a pair of comb-shaped electrodes facing each other in a direction parallel to one side of the substrate.

[0188] (5) The sensor device according to (4), wherein

[0189] The sensor electrode layer is disposed on the surface of the sensor sheet, the surface facing the reference electrode layer.

[0190] (6) The sensor device according to any one of (1) to (5) further includes

[0191] A support layer is disposed between the mounting surface on which the sensor device is mounted and the reference electrode layer, and the support layer is made of a flexible material.

[0192] (7) The sensor device according to any one of (1) to (6), wherein

[0193] The surface layer includes

[0194] The outer portion forming the input operation surface, and

[0195] The inner layer is disposed between the outer layer and the sensor sheet, and has an elastic modulus different from that of the outer layer.

[0196] (8) The sensor device according to any one of (1) to (6), wherein

[0197] The deformable layer includes

[0198] A first deformable layer is disposed on the surface of one side of the sensor sheet, and

[0199] A second deformable layer is disposed between the first deformable layer and the reference electrode layer, and has an elastic modulus different from that of the first deformable layer.

[0200] (9) The sensor device according to any one of (1) to (6), wherein

[0201] The surface layer includes

[0202] The flat plate portion forming the input operation surface, and

[0203] The legs are positioned on the periphery of the flat plate portion and supported by a mounting surface on which the sensor device is mounted.

[0204] (10) The sensor device according to any one of (1) to (9), wherein

[0205] The control unit includes a determining portion that determines which segment of a plurality of segments, defined according to a plurality of thresholds, the pressing pressure belongs to.

[0206] The plurality of thresholds include

[0207] The first pressure sensitivity is two or more times the touch sensitivity, which is the detection sensitivity of the sensor sheet, and the touch sensitivity is measured when the object being detected is in contact with the input operation surface.

[0208] The second pressure sensitivity is three times or more the same as the touch sensitivity.

[0209] (11) The sensor device according to (10), wherein

[0210] The plurality of thresholds further includes a third pressure sensitivity, which is four or more times the sensitivity of the touch sensitivity.

[0211] (12) The sensor device according to (10) or (11), wherein

[0212] The control unit further includes a threshold setting section, which is capable of individually adjusting the plurality of thresholds.

[0213] (13) The sensor device according to (12), wherein

[0214] The threshold setting section modifies the first pressure sensitivity and the second pressure sensitivity based on the area of ​​the operation performed by the detected object on the input operation surface.

[0215] (14) An electronic device, comprising

[0216] The sensor device includes:

[0217] A sensor chip capable of detecting pressure distribution;

[0218] A reference electrode layer, wherein the reference electrode layer is arranged on a surface facing the side of the sensor chip and is connected to a reference potential;

[0219] A deformable layer is disposed between the sensor sheet and the reference electrode layer and is made of a flexible material;

[0220] A surface layer having an input operation surface is disposed on the surface of the sensor sheet on the other side and is composed of a non-conductive material thicker than the deformable layer; and

[0221] The control unit is capable of performing a first detection process, which detects contact between a detection object and an input operating surface, and a second detection process, which detects the pressure applied by the detection object to the input operating surface, based on the output from the sensor chip. The control unit sets multiple thresholds to determine the magnitude of the pressure across multiple levels in the second detection process.

[0222] Reference Symbol List

[0223] 1. Pressure sensor

[0224] 10 sensor chips

[0225] 11. Base

[0226] 12 Sensor electrode layer

[0227] 13. Sensing Section

[0228] 20 Reference electrode layer

[0229] 30 Deformation Layer

[0230] 31 First Deformation Layer

[0231] 32 Second Deformation Layer

[0232] 40 Surface layer

[0233] 41 Outer layer

[0234] 42 Inner layer

[0235] 50 Support layers

[0236] 60 Control Unit

[0237] 61. Arithmetic Section

[0238] 62. Determining Part

[0239] 63 Threshold Setting Section

[0240] 70 Electronic devices

[0241] 71 Control equipment

[0242] Sensor devices 101, 102, 103, 104

[0243] 401 Flat Panel

[0244] 402 Legs

[0245] S Input Operation Surface

Claims

1. A sensor device, comprising: A sensor chip capable of detecting pressure distribution; A reference electrode layer, wherein the reference electrode layer is arranged on a surface facing the side of the sensor chip and is connected to a reference potential; A deformable layer is disposed between the sensor sheet and the reference electrode layer and is made of a flexible material; A surface layer having an input operation surface is disposed on the surface on the other side of the sensor sheet and is made of a non-conductive material that is thicker than the deformable layer; as well as The control unit is capable of performing a first detection process, which detects contact between a detection object and an input operating surface, and a second detection process, which detects the pressure applied by the detection object to the input operating surface, based on the output from the sensor chip. The control unit sets multiple thresholds to determine the magnitude of the pressure across multiple levels in the second detection process.

2. The sensor device according to claim 1, wherein... The surface layer has a thickness that is two or more times that of the deformable layer.

3. The sensor device according to claim 2, wherein... The surface layer is made of a material with an elastic modulus higher than that of the deformable layer.

4. The sensor device according to claim 2, wherein... The sensor chip includes Flexible substrate, and A sensor electrode layer, comprising a plurality of capacitive elements arranged in a matrix on a surface of one side of the substrate, and Each of the plurality of capacitive elements includes a pair of comb-shaped electrodes facing each other in a direction parallel to the surface of said side of the substrate.

5. The sensor device according to claim 4, wherein... The sensor electrode layer is disposed on the surface of the sensor sheet facing the reference electrode layer.

6. The sensor device according to claim 1, further comprising: A support layer is disposed between the mounting surface on which the sensor device is mounted and the reference electrode layer, and the support layer is made of a flexible material.

7. The sensor device according to claim 1, wherein... The surface layer includes The outer portion forming the input operation surface, and The inner layer is disposed between the outer layer and the sensor sheet, and has an elastic modulus different from that of the outer layer.

8. The sensor device according to claim 1, wherein... The deformable layer includes A first deformable layer disposed on the surface of said one side of the sensor sheet, and A second deformable layer is disposed between the first deformable layer and the reference electrode layer, and has an elastic modulus different from that of the first deformable layer.

9. The sensor device according to claim 1, wherein... The surface layer includes The flat plate portion forming the input operation surface, and The legs are positioned on the periphery of the flat plate portion and supported by a mounting surface on which the sensor device is mounted.

10. The sensor device according to claim 1, wherein... The control unit includes a determining portion that determines which segment of a plurality of segments, defined according to a plurality of thresholds, the pressing pressure belongs to. The plurality of thresholds include The first pressure sensitivity is two or more times the touch sensitivity, which is the detection sensitivity of the sensor sheet, and the touch sensitivity is measured when the object being detected is in contact with the input operation surface. The second pressure sensitivity is three times or more the same as the touch sensitivity.

11. The sensor device according to claim 10, wherein The plurality of thresholds further includes a third pressure sensitivity, which is four or more times the touch sensitivity.

12. The sensor device according to claim 10, wherein The control unit further includes a threshold setting section, which is capable of individually adjusting the plurality of thresholds.

13. The sensor device according to claim 12, wherein... The threshold setting section modifies the first pressure sensitivity and the second pressure sensitivity based on the area of ​​the operation performed by the detected object on the input operation surface.

14. An electronic device comprising Sensor device, the sensor device comprising: A sensor chip capable of detecting pressure distribution; A reference electrode layer, wherein the reference electrode layer is arranged on a surface facing the side of the sensor chip and is connected to a reference potential; A deformable layer is disposed between the sensor sheet and the reference electrode layer and is made of a flexible material; A surface layer having an input operation surface is disposed on the surface on the other side of the sensor sheet and is made of a non-conductive material that is thicker than the deformable layer; as well as The control unit is capable of performing a first detection process, which detects contact between a detection object and an input operating surface, and a second detection process, which detects the pressure applied by the detection object to the input operating surface, based on the output from the sensor chip. The control unit sets multiple thresholds to determine the magnitude of the pressure across multiple levels in the second detection process.

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