Sensor device and electronic instrument

Abstract

This sensor device comprises a sensor sheet, a front surface layer, a rear surface layer, a deformation layer, and a control unit. The sensor sheet is configured to be capable of detecting a pressure distribution. The front surface layer has an input operation surface, is disposed on one surface of the sensor sheet, and is composed of a non-conductive material. The rear surface layer is disposed on the other surface of the sensor sheet, has a conductive layer in at least a part thereof, and is composed of a material having higher rigidity than the front surface layer. The deformation layer is provided between the sensor sheet and the rear surface layer, and changes a distance between the sensor sheet and the rear surface layer according to a pressing force acting on the input operation surface. The control unit is configured to be capable of executing, on the basis of an output of the sensor sheet, a first detection process for detecting contact of a detection target with the input operation surface, and a second detection process for detecting a pressing force applied to the input operation surface.

Description

Sensor Device and Electronic Device

[0001] The present technology relates to a sensor device and an electronic device capable of detecting a touch operation and a pressing operation.

[0002] As a capacitance sensor capable of detecting a touch operation and a pressing operation, for example, Patent Document 1 discloses a ground electrode, a first electrode provided on the ground electrode and composed of a plurality of first sub-electrodes, a deformation layer provided between the installation electrode and the first electrode, a second electrode provided on the first electrode and composed of a plurality of second sub-electrodes, and a surface layer provided on the second electrode and having an operation surface.

[0003] Further, Patent Document 2 discloses a headset in which a touch sensor is provided in a housing portion worn on a user's ear.

[0004] [[ID=X]]WO 2018 / 025690, JP 2020-108166

[0005] In recent years, in this type of capacitance sensor, there is a demand for a sensor structure that can separate the touch function and the pressure-sensitive function, divide the pressure-sensitive function into multiple stages, and assign different functions according to the pressing operation amount. For this purpose, it is necessary that the pressing sensitivity when the operation surface is pressed with a finger is sufficiently large compared to the touch sensitivity when a finger touches the operation surface.

[0006] For example, in an acoustic device such as a headset provided with a pressure-sensitive sensor that uses the housing itself as a pressure-sensitive surface, the housing itself often has to be made of a hard material due to its strength requirements. In this case, since the housing itself is hard and the amount of deformation is small, it is difficult to detect pressing.

[0007] In view of the above circumstances, an object of the present technology is to provide a sensor device and an electronic device that enable pressing detection on a pressure-sensitive surface without reducing the strength of the housing itself.

[0008] A sensor device according to one embodiment of this technology comprises a sensor sheet, a surface layer, a back layer, a deformation layer, and a control unit. The sensor sheet is configured to detect pressure distribution. The surface layer has an input operating surface, is located on one side of the sensor sheet, and is made of a non-conductive material. The back layer is located on the other side of the sensor sheet, has at least a conductive layer in part, and is made of a material with higher rigidity than the surface layer. The deformation layer is provided between the sensor sheet and the back layer and changes the distance between the sensor sheet and the back layer in accordance with the pressing force acting on the input operating surface. The control unit is configured to perform a first detection process for detecting contact of an object to be detected with the input operating surface, and a second detection process for detecting the pressing force applied to the input operating surface, based on the output of the sensor sheet.

[0009] According to this technology, since the back layer is made of a material with higher rigidity than the surface layer, the deformation layer can be deformed by an amount corresponding to the amount of pressure applied. This makes it possible to detect pressure on the pressure-sensitive surface without reducing the strength of the housing itself.

[0010] The back surface layer may include a reference electrode layer connected to a reference potential and a rigid layer made of a non-conductive material having higher bending strength than the surface layer.

[0011] In this case, the surface layer may have a flat plate portion that forms the input operating surface and leg portions provided on the periphery of the flat plate portion to support the rigid layer.

[0012] The deformation layer may be made of a flexible material.

[0013] Alternatively, the deformation layer may include a spacer that forms a volume-variable spatial layer between the sensor sheet and the back surface layer.

[0014] In this case, the spacer may be provided on the peripheral edge of the surface layer.

[0015] On the other hand, the surface layer may have a thickness greater than the thickness of the deformation layer.

[0016] For example, the surface layer may have a thickness of twice or more the thickness of the deformation layer.

[0017] In this case, the surface layer may have a laminated structure of a non-conductive material and an elastic material.

[0018] The surface layer may have easily deformable regions including elastic portions, grooves, or slits.

[0019] The sensor sheet may have a sensor electrode layer comprising a flexible substrate and a plurality of capacitive elements arranged in a matrix on one surface of the substrate. Each of the plurality of capacitive elements may have a comb-shaped electrode pair facing each other in a direction parallel to one surface of the substrate.

[0020] The control unit may be configured to set a plurality of thresholds for determining the magnitude of the pressing force in multiple stages during the second detection process.

[0021] An electronic device according to one embodiment of this technology comprises a sensor device. The sensor device includes a sensor sheet, a surface layer, a back layer, a deformation layer, and a control unit. The sensor sheet is configured to detect pressure distribution. The surface layer has an input operating surface, is located on one side of the sensor sheet, and is made of a non-conductive material. The back layer is located on the other side of the sensor sheet, has at least a conductive layer in part, and is made of a material with higher rigidity than the surface layer. The deformation layer is provided between the sensor sheet and the back layer and changes the distance between the sensor sheet and the back layer in accordance with the pressing force acting on the input operating surface. The control unit is capable of performing a first detection process to detect contact of a target to be detected with the input operating surface based on the output of the sensor sheet, and a second detection process to detect the pressing force applied to the input operating surface. In the second detection process, a plurality of thresholds are set to determine the magnitude of the pressing force in multiple stages.

[0022] The surface layer may be part of the housing that houses the sensor device.

[0023] The aforementioned electronic device may be a head-mounted electronic device.

[0024] The aforementioned electronic device may be headphones.

[0025] This is a schematic front view showing headphones as an electronic device according to one embodiment of this technology. This is a schematic perspective view of the main part of the headphones. This is a schematic side cross-sectional view showing the internal structure of the main part of the headphones. This is a schematic rear view of the housing of the headphones showing a sensor device arranged inside the input operation surface. This is a schematic side cross-sectional view showing the basic configuration of the sensor device. This is a schematic plan view showing one example of the configuration of the sensor sheet in the sensor device. This is a schematic plan view showing one example of the configuration of the sensing part in the sensor device. This is a functional block diagram of the control unit in the sensor device. This is an explanatory diagram showing an example of the relationship between touch sensitivity and pressure sensitivity. This is an explanatory diagram showing the relationship between touch sensitivity and pressure sensitivity set in the sensor device. This is an experimental result showing the dependence of the thickness of the surface layer on displacement sensitivity. This is an experimental result showing the dependence of the structure (thickness, flexibility) of the surface layer on load sensitivity. This is a schematic side cross-sectional view showing a sensor device according to Configuration Example 1. This is a schematic side cross-sectional view showing a sensor device according to Configuration Example 2. This is a schematic side cross-sectional view showing a sensor device according to Configuration Example 3. This is a schematic side cross-sectional view showing a sensor device according to Configuration Example 4. This is a schematic side cross-sectional view showing a sensor device according to Configuration Example 5. This is a schematic side cross-sectional view showing a sensor device according to Configuration Example 6. This is a schematic side cross-sectional view showing a sensor device according to configuration example 7. This is a diagram showing another configuration example of the surface layer in the above sensor device, and is a perspective view showing the internal structure of the main part of the headphones. This is a perspective view showing the configuration example of the surface layer shown in Figure 20, and the simulation results explaining its operation. This is a perspective view showing another configuration example of the surface layer shown in Figure 20, and the simulation results explaining its operation. This is a schematic side cross-sectional view showing another configuration example of the surface layer in the above sensor device, and the simulation results explaining its operation. This is a schematic side cross-sectional view of the main part showing another configuration example of the sensor device attached to the headphones. This is a schematic side cross-sectional view showing a modified version of the sensor device shown in Figure 13.

[0026] The embodiments of this technology will be described below with reference to the drawings.

[0027] [Headphones] Figure 1 is a schematic front view showing headphones 1 as an electronic device according to one embodiment of this technology. Headphones 1 are worn on the head of user U and primarily reproduce the sound of content such as music. Headphones 1 may also have an ambient sound capture function (monitoring function) that captures and reproduces ambient sounds.

[0028] The headphones 1 have a housing portion 2R that is attached to the right ear of user U, a housing portion 2L that is attached to the left ear of user U, and a headband portion 3 that connects these two housing portions 2R and 2L.

[0029] Figure 2 is a schematic perspective view of the main parts of the headphones 1 as seen from the housing portion 2R side. One side of the housing portion 2R has an input operation surface (pressure-sensitive surface) S for performing various operations on the headphones 1, such as play / stop / volume adjustment / track skipping. In this embodiment, the housing 4 of the housing portion 2R is formed in a generally frustoelliptical shape, and the input operation surface S corresponds to a substantially elliptical flat surface that forms the apex of the frustoelliptical shape on the side of the housing 4 opposite to the user U side (earpad 5 side).

[0030] However, the input operation surface S may also be provided on the peripheral surface 4s of the housing 4, as shown by the dashed line in Figure 2, and the details thereof will be described later (see Figure 24).

[0031] Figure 3 is a schematic side cross-sectional view showing the internal structure of the housing portion 2R. The housing portion 2R includes a sensor device 100 that detects input operations on the input operation surface S and a drive unit 7 that reproduces audio signals.

[0032] The sensor device 100 is located on the back side of the housing 4, which forms the input operation surface S. The sensor device 100 has a control unit 60. As will be described later, the control unit 60 consists of a semiconductor chip component connected to the sensor sheet 11 that constitutes the sensor device 100, or a circuit board on which it is mounted (see Figure 6). The control unit 60 is located at any position inside the housing 4, for example, on the upper surface of the drive unit 7.

[0033] The drive unit 7 includes a controller 71, a speaker device 72, etc. The controller 71 includes a communication module for receiving audio signals, a drive circuit for driving the speaker device 72 based on detection signals from the sensor device 100, etc. The communication module may be a wireless module. The drive unit 7 may further include a battery, etc.

[0034] The drive unit 7 is located at the bottom of the housing 4 on the earpad 5 side and controls the entire headphones 1. The drive unit 7 is electrically connected to the sensor device 100 and performs various operations such as play / stop / volume adjustment / track skipping based on input operations on the input operation surface S.

[0035] The housing portion 2R may further include one or more physical switches, such as buttons, although these are not shown. The other housing portion 2L is configured in the same way as the housing portion 2R described above. The sensor device 100 is located only in the housing portion 2R, but it may also be located in the other housing portion 2L.

[0036] [Basic Configuration of the Sensor Device] Figure 4 is a schematic rear view of the housing 4 showing the sensor device 100 arranged inside the input operation surface S. As described above, the sensor device 100 is arranged on the back side of the housing 4 that forms the input operation surface S. The sensor device 100 is composed of a sheet-like member in which a plurality of capacitive elements (sensing parts N) capable of detecting the pressure distribution acting on the input operation surface S are arranged in a matrix. The details of the sensor device 100 will be described below.

[0037] Figures 5A and 5B are schematic side cross-sectional views showing the basic configuration of the sensor device 100, and Figure 6 is a schematic plan view showing one example of the configuration of the sensor sheet 10 in the sensor device 100. Figures 5A and 5B have common configurations except for the difference in the configuration of the deformation layer 40.

[0038] In Figures 5A, 5B, and 6, the X-axis and Y-axis directions are parallel to the input operation surface S (hereinafter also referred to as the in-plane direction), and the Z-axis direction is perpendicular to the input operation surface S (hereinafter also referred to as the perpendicular direction). Also, in Figure 5, the upper side corresponds to the front side to which the external force is applied, and the lower side corresponds to the opposite back side.

[0039] The sensor device 100 comprises a pressure sensor 6 and a rigid layer 32. The pressure sensor 6 is positioned on the inner surface of the housing 4 facing the input operation surface S. The pressure sensor 6 has a planar shape corresponding to the input operation surface S, and in this embodiment, it has a substantially elliptical or oblong flat plate structure (see Figure 4). As shown in Figures 5A and 5B, the pressure sensor 6 is composed of a laminate having a sensor sheet 10, a surface layer 20, a reference electrode layer 31, and a deformation layer 40.

[0040] (Sensor Sheet) The sensor sheet 10 is made of a flexible printed circuit board or the like having a base material 11 and a sensor electrode layer 12. The sensor electrode layer 12 has a plurality of capacitive elements (sensing section N) arranged in a matrix on the back surface of the base material 11 facing the reference electrode layer 31, and is configured to detect the pressure distribution acting on the input operation surface S. The thickness of the sensor sheet 10 is, for example, 50 μm or more and 300 μm or less, and in this embodiment it is 125 μm.

[0041] As shown in Figure 6, the base material 11 has a main body portion 111 with an elliptical or oblong planar shape, and a pull-out portion 112 extending outward from a part of the periphery of the main body portion 111. The material of the base material 11 is not particularly limited as long as it is a flexible insulating material, and polymer resins such as polyethylene terephthalate, polyimide, polycarbonate, and acrylic resin can be used.

[0042] The sensing units N correspond to nodes on the sensor sheet 10 and are arranged regularly in a matrix at predetermined intervals in the vertical and horizontal directions (vertical: Y-axis direction, horizontal: X-axis direction). The number of sensing units N is not particularly limited and can be arbitrarily set according to the size and shape of the input operation surface S, the resolution of the pressure distribution to be detected, etc. The sensing units N are composed of capacitive elements (detection elements) that can detect changes in the distance between them and the reference electrode layer 31 as changes in capacitance.

[0043] FIG. 7 is a schematic plan view showing a configuration example of the sensing unit N. The sensor electrode layer 12 has an electrode pair including a comb-shaped pulse electrode 121 and a comb-shaped sense electrode 122 that face each other in a direction parallel to the back surface of the base material 11 (the Y-axis direction in FIG. 7). The pulse electrode 121 and the sense electrode 122 are arranged such that their respective comb teeth face each other, and each sensing unit N is composed of a region (node area) arranged such that the comb teeth of one side enter between the comb teeth of the other side.

[0044] Each pulse electrode 121 is connected to a wiring portion 121a extending in the Y-axis direction, and each sense electrode 122 is connected to a wiring portion 122a extending in the X-axis direction. The wiring portions 121a are arranged at intervals in the X-axis direction on the back surface of the base material 11, and the wiring portions 122a are arranged at intervals in the Y-axis direction on the front surface of the base material 11. Each sense electrode 122 is electrically connected to the wiring portion 122a through a through hole 123 provided in the base material 11.

[0045] Alternatively, both the wiring portion 121a and the wiring portion 122a may be formed on the back surface of the base material 11, and these intersection portions may be insulated from each other using, for example, a jumper member. Since the pulse electrode 121 (wiring portion 121a) and the sense electrode 122 (wiring portion 122a) are formed on the back surface of the base material 11 (the surface facing the reference electrode layer 31), the distance between each of these electrodes 121, 122 and the input operation surface S increases by the thickness of the base material 11. Therefore, for example, the touch sensitivity can be suppressed to be small with respect to the pressure sensitivity.

[0046] The sensor electrode layer 12 may have a ground line. The ground line is provided, for example, at the outer peripheral portion of the sensor electrode layer 12 or at a portion where the wiring portions 121a and 122a run parallel to each other.

[0047] Note that the structure of the sensing unit N is not limited to the above example, and any structure may be used. For example, a laminate of a first electrode sheet having a lattice-shaped first electrode pattern extending in the X-axis direction and a second electrode sheet having a lattice-shaped second electrode pattern extending in the Y-axis direction may form the sensor electrode layer 12. In this case, the sensing unit N is formed at the intersection of the first electrode pattern and the second electrode pattern.

[0048] (Reference Electrode Layer) The reference electrode layer 31 is disposed to face one surface (back surface) of the sensor sheet 10. The reference electrode layer 31 is a conductive layer connected to a reference potential. In the present embodiment, the reference electrode layer 31 is a so-called ground electrode and is connected to the ground potential as the reference potential. The thickness of the reference electrode layer 31 is, for example, about 0.03 mm to 0.5 mm. As the material of the reference electrode layer 31, for example, an inorganic conductive material, an organic conductive material, a conductive material containing both an inorganic conductive material and an organic conductive material, or the like is used.

[0049] Examples of the inorganic conductive material include metals such as aluminum, copper, and silver, alloys such as stainless steel, and metal oxides such as zinc oxide and indium oxide. Examples of the organic conductive material include carbon materials such as carbon black and carbon fiber, and conductive polymers such as substituted or unsubstituted polyaniline and polypyrrole. The reference electrode layer 31 may be composed of a thin metal plate such as stainless steel or aluminum, conductive fibers, a conductive non-woven fabric, or the like. The reference electrode layer 31 may be formed on a plastic film by a method such as vapor deposition, sputtering, adhesion, coating, or the like.

[0050] (Deformation Layer) The deformation layer 40 is disposed between the sensor sheet 10 and the reference electrode layer 31. The deformation layer 40 has a function of changing the distance between the sensor sheet 10 and the reference electrode layer 31 in accordance with the pressing force acting on the input operation surface S. The thickness of the deformation layer 40 is, for example, about 100 μm to 1000 μm, and in the present embodiment, it is 500 μm or less.

[0051] The lower limit value of the thickness of the deformation layer 40 is not particularly limited as long as it is greater than 100 μm, but this lower limit value may be, for example, 150 μm or more, 200 μm or more, 250 μm or more, 300 μm or more, or the like. The upper limit value of the thickness of the deformation layer 40 is not particularly limited as long as it is 1000 μm or less, but this upper limit value may be, for example, 950 μm or more, 900 μm or less, 850 μm or less, 800 or less, or the like.

[0052] The deformation layer 40 may be made of a flexible material that can be elastically deformed in response to an external force, as shown in Figure 5A, or it may be made of a spacer 41 and a space layer 42 formed by the spacer 41, as shown in Figure 5B.

[0053] Examples of flexible materials include foamed materials (elastic foam), rubber, gels, nonwoven fabrics, and nanofibers. To facilitate deformation in the Z-axis direction, the flexible material may be constructed with a patterned structure that includes, for example, a columnar structure. This patterned structure can employ various structures such as matrix, stripe, mesh, radial, geometric, and helical patterns.

[0054] On the other hand, the spacer 41 is a frame-shaped or grid-shaped rigid body provided on at least a part of the peripheral edge of the sensor sheet 10, and is made of a metal material such as stainless steel or aluminum alloy, or a plastic material such as ABS resin or acrylic resin. The spacer 41 has an opening 41a that forms a volume-variable space layer 42 between the sensor sheet 10 and the reference electrode 31. The shape of the opening is not particularly limited and may be rectangular, circular, elliptical, etc. The space layer 42 may be an air layer or may be filled with the flexible material described above.

[0055] The spacer 41 is not limited to being bonded to the sensor sheet 10, but may also be bonded to the back side of the surface layer 20 (the side opposite to the input operation surface S). In this case, the spacer 41 is positioned outside the peripheral edge of the sensor sheet 10 and is formed with a greater thickness than the sensor sheet 10, thereby forming a space layer 42 between the sensor sheet 10 and the back layer 30 (reference electrode 31) (see Figure 13).

[0056] When an external force is applied perpendicular to the sensor sheet 10, the deformation layer 40 elastically deforms in response to the external force, causing the reference electrode layer 31 to move closer to the sensor electrode layer 12. At this time, the capacitance between the pulse electrode 121 and the sense electrode 122 changes in the sensing unit N, and the sensing unit N can detect this change in capacitance as a pressure value.

[0057] The deformation layer 40 is bonded to the sensor sheet 10 and the reference electrode layer 31 via a bonding material. As the bonding material, one or more adhesives selected from the group consisting of, for example, acrylic adhesives, silicone adhesives, and urethane adhesives can be used.

[0058] (Surface Layer) The surface layer 20 functions as the outer layer of the sensor device 100 and has an input operation surface S that is operated by the user. The input operation surface S also functions as a detection surface that comes into contact with the object to be detected by the sensor device 100 (such as the user's fingers) and detects touch and press operations on the sensor device 100 by the object to be detected. In this embodiment, the surface layer 20 corresponds to a part of the housing 4 of the housing portion 2R of the headphones 1 (see Figures 2 and 3).

[0059] The surface layer 20 is placed on one side (the top surface) of the sensor sheet 10. The surface layer 20 is made of a non-conductive material. Examples of non-conductive materials include electrically insulating materials such as synthetic resins, rubber, foamed materials (elastic foam), and nonwoven fabrics. As long as the entire surface layer 20 is electrically insulating, composite materials such as those in which conductive particles such as metal particles or metal flakes are mixed into a synthetic resin material may also be used.

[0060] The surface layer 20 is not particularly limited as long as it can detect touch operations on the input operation surface S. In this embodiment, the thickness of the surface layer 20 is greater than that of the deformation layer 40, which will be described later (for example, 2 to 3 times the thickness of the deformation layer 40). This makes it possible to increase the pressure sensitivity when the detection target presses on the input operation surface S compared to the touch sensitivity when the detection target contacts the input operation surface S. Furthermore, as will be described later, by making the pressure sensitivity sufficiently greater than the touch sensitivity, it becomes easier to divide the pressure-sensitive function into multiple stages.

[0061] Here, touch sensitivity corresponds to the change in capacitance of the sensing unit N when the object to be detected comes into contact with the input operation surface S, and pressure sensitivity corresponds to the change in capacitance of the sensing unit N when the object to be detected presses against the input operation surface S.

[0062] The thickness of the surface layer 20 is preferably at least twice the thickness of the deformation layer 40. This makes it easier to divide the pressure-sensitive function into multiple stages by making the pressure sensitivity significantly greater than the touch sensitivity, as will be described later.

[0063] The surface layer 20 may be made of a material with a higher elastic modulus than the deformation layer 40. In other words, by making the surface layer 20 of a harder material than the deformation layer 40, it becomes easier to separate the touch operation detection function from the press operation detection function, thereby suppressing malfunctions.

[0064] (Rigid Layer) The rigid layer 32 is configured as a support layer for supporting the pressure sensor 6. The rigid layer 32 is located on the other side (bottom surface) of the sensor sheet 10 and is made of a material that is more rigid than the surface layer 20. The rigid layer 32 is formed integrally with the reference electrode layer 31 to constitute the back surface layer 30 of the sensor device 100.

[0065] Since the rigid layer 32 is made of a material with higher bending rigidity than the surface layer 20, when the input operating surface S is subjected to a pressing force, the deformation amount of the rigid layer 32 is suppressed to be smaller than that of the pressure sensor 6 (sensor sheet 10, surface layer 20, and deformation layer 40). As a result, even if the deformation amount of the surface layer 20 is small, the deformation layer 40 can be deformed by an amount corresponding to the pressing force.

[0066] The rigid layer 32 is not particularly limited as long as it is made of a material with higher bending rigidity than the surface layer 20. For example, it can be made of a metallic material such as stainless steel or aluminum alloy, or a plastic material (non-conductive material) such as ABS resin or acrylic resin. The thickness of the rigid layer 32 is not particularly limited. For example, if the rigid layer 32 is made of metal, it is 0.2 mm or more, and if the rigid layer 32 is made of plastic, it is 1 mm or more.

[0067] If the rigid layer 32 is made of a metallic material, the installation of the reference electrode layer 31 may be omitted, and the rigid layer 32 itself may function as the reference electrode. Alternatively, the rigid layer 32 may be made of the same material as the surface layer 20. In this case, the rigid layer 32 can be formed with a greater thickness than the surface layer 20, thereby increasing its bending rigidity.

[0068] (Control Unit) The control unit 60 is typically a computer including a CPU (Central Processing Unit) and memory, and is composed of an integrated circuit such as an IC chip. The control unit 60 is mounted on the sensor sheet 10 (pull-out section 112) and is configured to drive the pressure sensor 6 and to receive the output signal from the pressure sensor 6.

[0069] Figure 8 is a functional block diagram of the control unit 60. The control unit 60 includes a calculation unit 61, a determination unit 62, and a threshold setting unit 63.

[0070] The calculation unit 61 calculates the change in capacity of each sensing unit N on the sensor sheet 10 based on the output of the pressure sensor 1. Based on the change in capacity, the calculation unit 61 calculates the pressure distribution on the input operating surface S.

[0071] The determination unit 62 determines which of the multiple categories, defined by a plurality of pre-set thresholds, the pressing force, which is the volume change amount calculated by the calculation unit 61, belongs to, and outputs the determination result to the controller 71 of the drive unit 7.

[0072] The threshold setting unit 63 sets the above-mentioned multiple thresholds. The control unit 60 may be configured as part of the controller 71 of the drive unit 7.

[0073] The control unit 60 is configured to perform a first detection process that detects contact between the target to be detected (user U's fingers) and the input operating surface S, based on the output of the pressure sensor 1 (sensor sheet 10), and a second detection process that detects the pressure distribution on the input operating surface S and its change over time. In the second detection process, the control unit 60 detects the pressing force applied to the input operating surface S and sets multiple thresholds for determining the magnitude of that pressing force in multiple stages.

[0074] While a typical touch sensor limits a single tap operation to one type of assignment, the sensor device 100 of this embodiment, which has both touch and pressure-sensitive functions, allows for four types of assignments, for example, divided into touch, low pressure, medium pressure, and high pressure. As a specific example of use, while a typical touch sensor can only turn the power on / off with a tap, this embodiment allows for not only turning the power on / off, but also, for example, slightly increasing / decreasing the volume, normally increasing / decreasing the volume, and significantly increasing / decreasing the volume.

[0075] Other examples of its operation include song selection (fast forward, skip tracks, skip albums). It can also be used for zoom level in cameras, multi-level detection of controller pressure in game consoles, and brightness adjustment of display screens and lights in mobile devices.

[0076] In order to assign multi-stage operations using touch and pressure sensitivity functions, the pressure sensitivity when pressing the input operation surface S with a finger must be sufficiently greater than the touch sensitivity when touching the input operation surface S with a finger. When assigning one operation each for touch sensitivity and pressure sensitivity (a total of two operations), a threshold Th1 is set in the touch sensitivity region and a threshold Th2 is set in the pressure sensitivity region, as shown in Figure 9. In Figure 9, 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.

[0077] Thresholds Th1 and Th2 must be sufficiently far apart to prevent false detections (malfunctions). Preferably, threshold Th2 is at least twice the value of threshold Th1 (Th2 ≥ 2 * Th1). Furthermore, when assigning multi-stage operations, since only one threshold can be set in the touch sensitivity area, it is necessary to set multiple thresholds in the sensitivity area.

[0078] For example, when assigning four operations, as shown in Figure 10, a threshold Th1 (touch sensitivity) is set in the touch area, and three thresholds Th2 (first pressure sensitivity), Th3 (second pressure sensitivity), and Th4 (third pressure sensitivity) are set in the pressure-sensitive area. In this case, it is preferable that Th2 ≥ 2 * Th1, Th3 ≥ 3 * Th1, and Th4 ≥ 4 * Th1. When setting multiple thresholds under such conditions, the sensor structure must be such that the pressure sensitivity is sufficiently greater than the touch sensitivity.

[0079] Displacement sensitivity will now be explained. Displacement sensitivity refers to the relationship between the amount of displacement of the object to be detected (e.g., the user's fingers) relative to the input operating surface S and the detection sensitivity. Figure 11 shows an experimental result illustrating the dependence of displacement sensitivity on the thickness of the surface layer 20. In this figure, the sensitivity at a displacement of 0 corresponds to touch sensitivity, and the region where the displacement is positive corresponds to pressure sensitivity. The material of the surface layer 20 is a single layer of acrylic plate.

[0080] In Figure 11, A1 shows the displacement sensitivity when the thickness of the surface layer 20 is the same as the thickness of the deformation layer 40 (0.5 mm), and A2 shows the displacement sensitivity when the thickness of the surface layer 20 is three times the thickness of the deformation layer 40 (1.5 mm). In A1, the touch sensitivity is high, so the pressure sensitivity threshold becomes high, making it difficult to separate the touch function from the pressure sensitivity function. In contrast, in A2, since the touch sensitivity can be lowered, the pressure sensitivity threshold can be set to be sufficiently larger than the touch sensitivity threshold, making it easier to separate the touch function from the pressure sensitivity function, and allowing multiple thresholds to be set in the pressure-sensitive area.

[0081] Next, we will explain load sensitivity. Load sensitivity refers to the relationship between the vertical load acting on the input operating surface S and the detection sensitivity. Figure 12 shows an experimental result illustrating the dependence of the structure (thickness, flexibility) of the surface layer 20 on load sensitivity.

[0082] In Figure 12, B1 shows the load sensitivity when the thickness of the surface layer 20 is the same as the thickness of the deformation layer 40 (0.5 mm). B2 shows the load sensitivity when the surface layer 20 has a laminated structure consisting of an outer layer that forms the input operation surface S and an inner layer on the sensor sheet 10 side, with the outer layer being an acrylic plate with a thickness of 0.5 mm and the inner layer being a rubber plate with a thickness of 1.0 mm. B3 shows the load sensitivity when the thickness of the surface layer 20 is three times the thickness of the deformation layer 30 (1.5 mm) and it is an acrylic plate.

[0083] As shown in Figure 12, the load sensitivity tends to decrease in the order of B1, B2, and B3. This is because increasing the thickness of the surface layer 20 makes it harder. Therefore, in order to suppress the decrease in load sensitivity, the surface layer 40 needs to be soft. By making the surface layer 40 soft, it becomes easier to separate the touch function and the pressure-sensitive function in terms of load sensitivity.

[0084] In the sensor device 100 of this embodiment, as described above, the surface layer 40 is formed with a greater thickness than the deformation layer 30. Therefore, as described above, compared to the case where the surface layer 40 has the same thickness as the deformation layer 30, the pressure sensitivity can be made sufficiently greater than the touch sensitivity, and the pressure-sensitive function can be divided into multiple stages.

[0085] [Details of the Sensor Device] In audio equipment such as headphones equipped with a pressure sensor that uses the housing itself as a pressure-sensitive surface, the housing itself is often made of a hard material due to its strength requirements. In this case, because the housing itself is hard and the amount of deformation is small, it becomes difficult to detect pressure. On the other hand, if one tries to increase the pressure detection sensitivity by reducing the strength of the housing itself and increasing the amount of deformation, there is a risk that the rigidity of the housing will be insufficient and the desired acoustic performance cannot be secured. To solve these problems, in this embodiment, the sensor device is configured as follows in order to enable pressure detection on the pressure-sensitive surface without reducing the strength of the housing itself.

[0086] Figures 13 to 19 are schematic side cross-sectional views showing the details of the sensor device 100. In each figure, parts corresponding to those in Figure 5 are denoted by the same reference numerals, and their descriptions are omitted or simplified.

[0087] (Configuration Example 1) Figure 13 shows a sensor device 101 according to Configuration Example 1. In this figure, the surface layer 20 forms a part of the housing portion 2R and is integrally formed with the back surface layer 30, which is a laminate of the reference electrode layer 31 and the rigid layer 32, via the spacer 41 of the deformation layer 40. The sensor sheet 10 faces the back surface layer 30 via the space layer 42, and the distance between the sensor sheet 10 and the back surface layer 30 is configured to be variable according to the pressing force applied to the input operation surface S.

[0088] In the sensor device 101 configured in this way, the back layer 30 has higher rigidity than the surface layer 20 which is integrally connected via the spacer 41. Therefore, when the surface layer 20 deforms due to a pressing operation on the input operation surface S, the back layer 30 faces the sensor sheet 10 with a smaller amount of deformation (or without deformation) than the surface layer 20. As a result, even when the amount of deformation of the surface layer 20 is small, the deformation layer 40 can be deformed by an amount of deformation corresponding to the amount of pressing operation on the input operation surface S (reducing the distance between the sensor sheet 10 and the back layer 30), making it possible to detect pressing on the input operation surface S without reducing the strength of the housing portion 2R.

[0089] The back layer 30 is not limited to a structure supported by the front layer 20, but may also be configured as part of the housing 4.

[0090] (Configuration Example 2) Figure 14 shows a sensor device 102 according to Configuration Example 2. In this figure, the housing 4 has an annular recess 4a that supports the surface layer 20 and a bottomed recess 4b that supports the back layer 30. The back layer 30 is integrally formed with the housing 4 by being joined to the bottomed recess 4b. The surface layer 20 supports the sensor sheet 10 facing the back layer 30 via a space layer 42 (deformation layer 40), and the peripheral edge of the surface layer 20 is joined to the annular recess 4a, forming it as part of the housing 4.

[0091] The stepped portion between the annular recess 4a and the bottomed recess 4b functions as a spacer 41 that forms a space layer 42. In other words, the spacer 41 is formed as part of the housing 4. The surface layer 20 may be made of the same material as the housing 4 (a non-conductive material), but in order to increase the amount of deformation of the surface layer 20, the surface layer 20 may be made of any material that is less rigid than the constituent material of the housing 4. For example, the surface layer 20 may be made of the same material as the housing 4 but thinner than the thickness of the housing 4, or the material itself may be made of a soft material, etc.

[0092] In the sensor device 102 configured in this way, the back layer 30 is integrally formed with the housing 4. Therefore, when the surface layer 20 deforms due to a pressing operation on the input operation surface S, the back layer 30 remains undeformed and faces the sensor sheet 10. As a result, even if the amount of deformation of the surface layer 20 is small, the deformation layer 40 can be deformed by an amount corresponding to the amount of pressing operation on the input operation surface S (reducing the distance between the sensor sheet 10 and the back layer 30). This enables pressure detection on the input operation surface S without reducing the strength of the housing portion 2R.

[0093] Furthermore, since the surface layer 20 can be made of a separate material from the housing 4, the surface layer 20 can be formed from a material with lower rigidity than the housing 4. This allows for a larger deformation of the surface layer 20, thereby improving sensitivity during pressure detection and making it easy to set multiple thresholds for executing different control modes depending on the amount of pressure.

[0094] Furthermore, by allowing a larger deformation of the surface layer 20 (input operation surface S), the gap distance between the sensor sheet 10 and the reference electrode layer 31 (back surface layer 30) can be increased. This increased gap distance allows for a relaxation of the assembly precision requirements for the sensor device, and consequently, a relaxation of the precision requirements for the components. This reduces the difficulty of mass production, enabling increased feasibility of mass production, stable mass production quality, and reduced procurement costs through reduced management man-hours. Moreover, even with the same pressing force as before, the increased deformation allows for the desired operation to be performed with less operating force, thereby improving the usability of the headphones 1.

[0095] (Configuration Example 3) Figure 15 shows a sensor device 103 according to Configuration Example 3. In this figure, the housing 4 has an annular recess 4a that supports the surface layer 20 and an annular projection 4c that supports the back layer 30. The annular recess 4a forms the upper surface of the annular projection 4c. The back layer 30 is integrally formed with the housing 4 by being joined to the back surface of the projection 4c (the surface opposite to the annular recess 4a). The surface layer 20 supports the sensor sheet 10 facing the back layer 30 via a space layer 42 (deformation layer 40), and the peripheral edge of the surface layer 20 is joined to the annular recess 4a, forming it as part of the housing 4. This makes it possible to obtain the same effects as in Configuration Example 2.

[0096] The annular projection 4c functions as a spacer 41 that forms the space layer 42. In other words, the spacer 41 is formed as part of the housing 4. The surface layer 20 may be made of the same material as the housing 4 (a non-conductive material), but in order to increase the amount of deformation of the surface layer 20, the surface layer 20 may be made of any material that has lower rigidity than the constituent material of the housing 4, as described above. Since the thickness of the annular projection 4c corresponds to the opposing distance (gap) between the sensor sheet 10 and the back layer 30, the dimension control of the above gap becomes relatively easy by having the annular projection 4c function as a spacer 41.

[0097] (Configuration Example 4) Figure 16 shows a sensor device 104 according to Configuration Example 4. In the figure, the surface layer 20 has a main surface portion 21 that forms the input operation surface S, leg portions 22 formed on the periphery of the main surface portion 21, and an annular elastic portion 23 disposed between the main surface portion 21 and the leg portions 22.

[0098] The main surface portion 22 supports the sensor sheet 10. The shape of the main surface portion 22 is flat, but is not limited to this, and may be a curved shape (curved shape) that is convex upward or downward in the figure. The leg portion 22 is configured as part of the housing 4 and is composed of a cylindrical body or a plurality of columnar bodies that can support the back surface layer 30 at its lower end. The leg portion 22 also functions as a spacer 41 that forms the space layer 42. The elastic portion 23 is composed of an annular component such as rubber that connects the main surface portion 21 and the leg portion 22, and forms an easily deformable region that elastically supports the main surface portion 21 relative to the leg portion 22.

[0099] With the sensor device 104 configured in this way, the same effects as in configuration examples 1 to 3 can be obtained, and because the surface layer 20 has an easily deformable region including the elastic portion 23, the amount of deformation of the input operation surface S can be increased, thereby enabling accurate detection of the amount of pressing operation.

[0100] (Configuration Example 5) Figure 17 shows a sensor device 105 according to Configuration Example 5. In this figure, the surface layer 20 has, similar to Configuration Example 4, a main surface portion 21 that forms the input operation surface S, leg portions 22 formed on the periphery of the main surface portion 21, and an annular elastic portion 24 disposed between the main surface portion 21 and the leg portions 22.

[0101] In this example, the elastic portion 24 is positioned between the lower peripheral edge of the main surface portion 21 and the leg portion 22, which is different from the above-described configuration example 4. In this example as well, the elastic portion 24 forms an easily deformable region that elastically supports the main surface portion 21 relative to the leg portion 22. This allows for the same effects as in configuration example 4 to be obtained.

[0102] (Configuration Example 6) Figure 18 shows a sensor device 106 according to Configuration Example 6. In this figure, the surface layer 20 constitutes a part of the housing 4, and differs from Configuration Example 1 in that the input operation surface S is formed by an uneven surface 25. The uneven surface 25 includes thin-walled portions that are cut out in a mesh-like, multiple concentric, spiral, or grid pattern on the upper surface (outer surface) of the surface layer 20, thereby forming the input operation surface S as an easily deformable region. This configuration also reduces the rigidity of the surface layer 20, so that the same effects as Configuration Examples 4 and 5 can be obtained. Note that the uneven surface 25 is not limited to being formed on the upper surface of the surface layer 20, but may also be formed on the lower surface (inner surface) of the surface layer 20 (see Figure 20).

[0103] (Configuration Example 7) Figure 19 shows a sensor device 107 according to Configuration Example 7. In this figure, the surface layer 20 constitutes a part of the housing 4 and differs from Configuration Example 1 in that the surface layer 20 has a multilayer structure in which an elastic layer 26 is sandwiched between non-conductive materials such as plastic. Even when the surface layer 20 has a laminated structure of a non-conductive material and an elastic material, the input operation surface S can be formed as an easily deformable region, so the same effects as in Configuration Examples 4 to 6 can be obtained. Furthermore, this configuration example may be combined with Configuration Example 6, which makes the input operation surface S even easier to deform.

[0104] [Other Examples of Surface Layer Configuration] Next, with reference to Figures 20 to 22, other examples of the surface layer 20 configuration will be described.

[0105] Figure 20 is a perspective view of the housing 4 of the housing portion 2R, seen from its inner surface. In this configuration example, a recessed portion 27 is provided in the center of the inner surface of the surface layer 20. The recessed portion 27 is formed by two or more concentric circles with a cross-sectional shape of a square groove or a round groove.

[0106] The uneven surface 27 forms an easily deformable region on the input operation surface S, thereby providing the same effects as in the configuration example 6. Furthermore, since the uneven surface 27 is provided on the back surface (inner surface) of the surface layer 20 opposite to the input operation surface S, a slide operation can be properly performed on the input operation surface S to move the touch position or press position in the direction intended by the user, without being affected by the uneven shape.

[0107] As an example, the difference in deformation amount depending on the presence or absence of the uneven portion 27 and the number of uneven portions will be explained with reference to Figures 21A to C.

[0108] Figure 21A is a perspective view showing the back side of the surface layer 20. Sample A1 shows a surface layer 20 without any irregularities, Sample A2 shows a surface layer 20 with irregularities 27 consisting of two concentric circles, and Sample A3 shows a surface layer 20 with irregularities 27 consisting of three concentric circles. Figure 21B shows the simulation results comparing the amount of deformation in response to the pressing load applied under the same conditions for the three surface layer 20 samples A1 to A3. Figure 21C is a schematic side cross-sectional view of the surface layer 20 having the irregularities 27.

[0109] Here, a surface layer 20 made of ABS resin with a thickness of 1.7 mm (Young's modulus E = 2.4 GPa) was used, and a pressing force of 3 N was applied perpendicularly (normal to the surface layer 20) to the center of the surface layer 20. In sample A2, the width of the grooves G forming the uneven portion 27 was 1.5 mm, the thickness (thickness of the thin portion forming the bottom of the groove G; the same applies hereinafter) was 0.3 mm, and the central radii of each groove G were 10 mm and 25 mm. In sample A3, the width of the grooves G forming the uneven portion 27 was 1.5 mm, the thickness was 0.2 mm, and the central radii of each groove G were 10 mm, 21 mm, and 32 mm.

[0110] As shown in Figure 21B, samples A2 and A3, which have surface layers 20 with uneven surfaces 27, exhibit greater deformation than sample A1, which has surface layers 20 without uneven surfaces 27. For example, comparing sample A1 and sample A3, it was confirmed that the deformation of sample A3 was approximately twice that of sample A1. Furthermore, it was found that sample A3, which has a larger number of grooves G forming the uneven surfaces 27 and a larger central radius of the grooves G, exhibits greater deformation than sample A2. In addition, for sample A3, it was confirmed that the smaller the wall thickness at the bottom of the grooves G, the greater the deformation in the center. Thus, by optimizing the number and size of grooves G according to the type of material constituting the surface layer 20, the desired deformation can be obtained.

[0111] Figure 22A is a perspective view showing another configuration example of the surface layer 20, in which a helical slit portion 28 forming an easily deformable region is provided in the center of the input operating surface S. In the same figure, samples A4 and A5 both have a pair of helical slit portions 28 arranged concentrically, with sample A4 showing a surface layer 20 in which the rotation angle of each slit portion 28 is 360°, and sample A5 showing a surface layer 20 in which the rotation angle of each slit portion 28 is 540°. Figure 22B is a simulation result showing a comparison of the amount of deformation in response to the pressing load applied under the same conditions in samples A4 and A5 of the two surface layers 20.

[0112] In this experiment, a surface layer 20 made of ABS resin with a thickness of 1.7 mm (Young's modulus E = 2.4 GPa) was used, and a pressing force of 3 N was applied perpendicularly (normal to the surface layer 20) to the center of the surface layer 20. The width of each slit portion 28 was set to 1 mm.

[0113] As shown in Figure 22B, the deformation of sample A5 is greater than that of sample A4, approximately five times greater in this example. This confirms that the larger the rotation angle of the helical slit portion 28, the greater the deformation. In this way, the desired deformation can be obtained by optimizing the rotation angle of the slit portion 28 according to the type of material constituting the surface layer 20.

[0114] Figure 23A is a schematic side cross-sectional view of a sensor device 108 showing yet another configuration example of the surface layer 20. Figure 23B is a simulation result comparing the deformation amounts of the surface layer 20 and the back layer 30 when a vertical load of 3N is pressed onto the center of the input operating surface S of this sensor device 108.

[0115] The surface layer 20 (input operation surface S) is formed in a curved (dome) shape with its central part convex outward. The surface layer 20 is formed, for example, from an ABS plate with a thickness of 1.7 mm. The radius of curvature of the surface layer 20 can be arbitrarily set within the range in which the desired amount of deformation can be obtained, and in this case it is set to 500 mm or less. For example, if the planar shape of the surface layer 20 is elliptical, the radius of curvature in the direction of the major axis and the radius of curvature in the direction of the minor axis may be different from each other.

[0116] The sensor sheet 10 is bonded to the inner surface of the surface layer 20 so as to conform to the curved shape of the surface layer 20. The back layer 30 (reference electrode 31) is supported by the inner circumference 4d of the housing 4, which also serves as a spacer 41, so as to face the sensor sheet 10 across the space layer 42. The thickness of the space layer 42 is, for example, 0.1 mm to 0.5 mm. The back layer 30 is made of a flat plate made of a material (for example, metal) with higher rigidity than the surface layer 20.

[0117] In the sensor device 108 configured as described above, as shown in Figure 23B, the deformation amount of the surface layer 20 is about three times greater than the deformation amount of the back layer 30. Moreover, because the surface layer 20 has a curved shape, when a pressing operation is performed perpendicular to the input operating surface S, the surface layer 20 deforms not only in that perpendicular direction but also in a direction that flattens the surface layer 20, thereby allowing for a large change in the distance between the sensor sheet 10 and the back layer 30. As a result, it is possible to detect the amount of pressure with high sensitivity even when the deformation amount of the surface layer 20 is small.

[0118] [Other configuration examples of the sensor device] As described above, the input operation surface S may be provided on the peripheral surface portion 4s (see Figure 2) of the housing 4 of the housing 2R. Figure 24 is a side cross-sectional view of the main part showing one configuration example of a sensor device 109 provided on the peripheral surface portion 4s of the housing 4.

[0119] The peripheral surface portion 4s of the housing 4 has an opening 4h that accommodates the input operating surface of the sensor device 109. The surface layer 20 of the sensor device 109 is fitted into the opening 4h from the inside of the peripheral surface portion 4s, and the flange portion 29 provided on the peripheral edge of the surface layer 20 is joined to the inside of the peripheral surface portion 4s, thereby forming an integral part with the housing 4. The back surface layer 30 (reference electrode 31) is joined to the bottom surface of the flange portion 29, thereby forming an integral part with the surface layer 20. The sensor sheet 10 and the deformation layer 40 are arranged between the surface layer 20 and the back surface layer 30.

[0120] The sensor device 109 configured in this way performs the same function as the sensor device 101 according to Configuration Example 1 (Figure 13). That is, since the back layer 30 has higher rigidity than the surface layer 20 which is integrally connected via the flange portion 29, when the surface layer 20 deforms due to a pressing operation on the input operation surface S, the back layer 30 faces the sensor sheet 10 with a smaller amount of deformation than the surface layer 20 (or without deformation at all). As a result, even if the amount of deformation of the surface layer 20 is small, the deformation layer 40 can be deformed by an amount of deformation corresponding to the amount of pressing operation on the input operation surface S (reducing the distance between the sensor sheet 10 and the back layer 30), so that pressing detection on the input operation surface S is possible without reducing the strength of the housing portion 2R.

[0121] In the sensor device 109, the planar shape of the surface layer 20 is formed as a rectangle with a longer side in the circumferential direction of the peripheral surface portion 4s. In this case, the sensing portions N of the sensor sheet 10 are not limited to being arranged two-dimensionally (in a matrix), but may be arranged one-dimensionally in the direction of the longer side. In this case, the headphones 1 may be configured so that the desired control mode is executed according to the contact position (pressing position) on the input operation surface S, or by a sliding operation along the direction of the longer side.

[0122] [Modifications] In the above embodiments, headphones were used as an example of an electronic device on which the sensor device 100 is mounted. However, the technology is not limited to headphones, and can be applied to other head-mounted electronic devices such as earphones and head-mounted displays, as well as camera grips, game controllers, remote controllers, and other handheld electronic devices.

[0123] Furthermore, although the sensor sheet 10 (sensor electrode layer 12) was made of a separate material from the surface layer 20 in the above embodiment, the invention is not limited to this. For example, as schematically shown in Figure 25, the sensor electrode layer 13, which serves as the sensor sheet 10, may be integrally formed on the inner side of the surface layer 20 (the side opposite to the input operation surface S). This reduces the number of components and allows for a larger gap distance between the sensor sheet 10 and the reference electrode layer 31 (back surface layer 30). As a method for forming the sensor electrode layer 13, for example, a method such as LDS (Laser Direct Structuring) can be employed.

[0124] Furthermore, this technology can also take the following configurations: (1) A sensor device comprising: a sensor sheet capable of detecting pressure distribution; a surface layer having an input operating surface and disposed on one side of the sensor sheet, and made of a non-conductive material; a back layer disposed on the other side of the sensor sheet, having at least a conductive layer in part, and made of a material with higher rigidity than the surface layer; a deformation layer provided between the sensor sheet and the back layer, which changes the distance between the sensor sheet and the back layer in accordance with the pressing force acting on the input operating surface; and a control unit configured to perform a first detection process for detecting contact of an object to be detected to the input operating surface and a second detection process for detecting the pressing force applied to the input operating surface, based on the output of the sensor sheet. (2) The sensor device according to (1) above, wherein the back layer comprises: a reference electrode layer connected to a reference potential; and a rigid layer made of a non-conductive material having higher bending strength than the surface layer. (3) A sensor device according to (2) above, wherein the surface layer comprises a main surface portion that forms the input operating surface, and a leg portion provided on the periphery of the main surface portion that supports the rigid layer. (4) A sensor device according to any one of (1) to (3) above, wherein the deformation layer is made of a flexible material. (5) A sensor device according to any one of (1) to (3) above, wherein the deformation layer includes a spacer that forms a volume-variable space layer between the sensor sheet and the back surface layer. (6) A sensor device according to (5) above, wherein the spacer is provided on the periphery of the surface layer. (7) A sensor device according to any one of (1) to (6) above, wherein the surface layer has a thickness greater than the thickness of the deformation layer. (8) A sensor device according to (7) above, wherein the surface layer has a thickness of twice or more the thickness of the deformation layer. (9) A sensor device according to (7) or (8) above, wherein the surface layer has a laminated structure of a non-conductive material and an elastic material.(10) A sensor device according to any one of (7) to (9) above, wherein the surface layer has an easily deformable region including an elastic portion, a groove portion, or a slit portion. (11) A sensor device according to (1) to (10) above, wherein the sensor sheet has a sensor electrode layer having a flexible substrate and a plurality of capacitive elements arranged in a matrix on one surface of the substrate, and each of the plurality of capacitive elements has a comb-shaped electrode pair facing each other in a direction parallel to one surface of the substrate. (12) A sensor device according to any one of (1) to (11) above, wherein the control unit sets a plurality of thresholds for determining the magnitude of the pressing force in multiple stages in the second detection process. (13) Electronic device comprising a sensor sheet capable of detecting pressure distribution; a surface layer having an input operating surface and disposed on one side of the sensor sheet and made of a non-conductive material; a back layer disposed on the other side of the sensor sheet and having at least a conductive layer in part and made of a material with higher rigidity than the surface layer; a deformation layer provided between the sensor sheet and the back layer and changing the distance between the sensor sheet and the back layer in accordance with the pressing force acting on the input operating surface; and a control unit capable of performing a first detection process to detect contact of an object to be detected to the input operating surface and a second detection process to detect the pressing force on the input operating surface based on the output of the sensor sheet, wherein the second detection process sets a plurality of thresholds for determining the magnitude of the pressing force in multiple stages. (14) Electronic device according to (13) above, wherein the surface layer is part of a housing that houses the sensor device. (15) Electronic device according to (14) above, wherein the electronic device is a head-mounted electronic device. (16) Electronic device according to (15) above, wherein the electronic device is headphones.

[0125] 1...Headphones 4...Housing 10...Sensor sheet 12...Sensor electrode layer 20...Surface layer 21...Main surface 22...Legs 30...Back surface layer 31...Reference electrode layer 32...Rigid layer 40...Deformation layer 41...Spacer 42...Vacuum layer 60...Control unit 100-109...Sensor device

Claims

1. A sensor device comprising: a sensor sheet capable of detecting pressure distribution; a surface layer having an input operating surface and disposed on one side of the sensor sheet, made of a non-conductive material; a back layer disposed on the other side of the sensor sheet, having at least a conductive layer in part, and made of a material with higher rigidity than the surface layer; a deformation layer provided between the sensor sheet and the back layer, which changes the distance between the sensor sheet and the back layer in accordance with the pressing force acting on the input operating surface; and a control unit configured to perform a first detection process for detecting contact of an object to be detected to the input operating surface and a second detection process for detecting the pressing force applied to the input operating surface, based on the output of the sensor sheet.

2. A sensor device according to claim 1, wherein the back surface layer comprises a reference electrode layer connected to a reference potential and a rigid layer made of a non-conductive material having higher bending strength than the surface layer.

3. A sensor device according to claim 2, wherein the surface layer comprises a main surface portion that forms the input operating surface, and a leg portion provided on the peripheral edge of the main surface portion and supporting the rigid layer.

4. A sensor device according to claim 1, wherein the deformation layer is made of a flexible material.

5. A sensor device according to claim 1, wherein the deformation layer includes a spacer that forms a volume-variable space layer between the sensor sheet and the back surface layer.

6. A sensor device according to claim 5, wherein the spacer is provided on the peripheral edge of the surface layer.

7. A sensor device according to claim 1, wherein the surface layer has a thickness greater than the thickness of the deformation layer.

8. A sensor device according to claim 7, wherein the surface layer has a thickness of twice or more the thickness of the deformation layer.

9. A sensor device according to claim 7, wherein the surface layer has a laminated structure of a non-conductive material and an elastic material.

10. A sensor device according to claim 7, wherein the surface layer has an easily deformable region including an elastic portion, a groove portion, or a slit portion.

11. A sensor device according to claim 1, wherein the sensor sheet has a sensor electrode layer having a flexible substrate and a plurality of capacitive elements arranged in a matrix on one surface of the substrate, and each of the plurality of capacitive elements has a comb-shaped electrode pair facing each other in a direction parallel to one surface of the substrate.

12. A sensor device according to claim 1, wherein the control unit sets a plurality of thresholds for determining the magnitude of the pressing force in multiple stages in the second detection process.

13. Electronic device comprising a sensor sheet capable of detecting pressure distribution; a surface layer having an input operating surface and disposed on one side of the sensor sheet, and made of a non-conductive material; a back layer disposed on the other side of the sensor sheet, having at least a conductive layer in part, and made of a material with higher rigidity than the surface layer; a deformation layer provided between the sensor sheet and the back layer, which changes the distance between the sensor sheet and the back layer in accordance with the pressing force acting on the input operating surface; and a control unit capable of performing a first detection process to detect contact of a target to be detected with the input operating surface based on the output of the sensor sheet, and a second detection process to detect the pressing force applied to the input operating surface, wherein the second detection process sets a plurality of thresholds for determining the magnitude of the pressing force in multiple stages.

14. An electronic device according to claim 13, wherein the surface layer is part of a housing that houses the sensor device.

15. The electronic device according to claim 14, wherein the electronic device is a head-mounted electronic device.

16. The electronic device according to claim 15, wherein the electronic device is a pair of headphones.

Images