Capacitive input device

Abstract

To provide a capacitive input device that enables a user to sense input by touch.SOLUTION: An operation switch 10A includes a surface sheet 20, a soft member 30, and a sensor sheet 40 that detects changes in capacitance. The surface sheet 20 has an operation area 21 that is operated by touch and a peripheral area 22 around the operation area 21. The soft member 30 is disposed between the operation area 21 and the sensor sheet 40. The sensor sheet 40 includes a sensor electrode 42 at a position corresponding to the operation area 21. When the operation area 21 is pressed by a touch operation, at least one of the surface sheet 20 and the soft member 30 is compressed and deformed toward the sensor sheet 40, displacing the surface sheet 20 toward the sensor sheet 40, and the capacitance is detected by the sensor electrode 42. The peripheral area 22 is harder than the operation area 21.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The disclosure according to the present application relates to a capacitive input device.

Background Art

[0002] As an input device for an electronic device, a touch input device including a capacitance sensor is known. Such a capacitive input device (capacitive touch input device) detects a change in capacitance caused by a user touching an operation area arranged on a housing of an electronic device with a finger (for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Push button switches (physical keys) that are physically displaced for input are also widely used as input devices for electronic devices. In an input operation using such a push button switch, there is an operation feeling associated with physical displacement, so that a user can sense that an input has been made by touch.

[0005] On the other hand, in a capacitive touch input device, the housing of the electronic device is hard and there is no change in the touch feeling even when touched with a finger, so it is difficult for the user to confirm that an input operation has been performed.

Means for Solving the Problems

[0006] Some aspects disclosed in the present application are configured to have the following features.

[0007] That is, one aspect disclosed in the present application includes a surface member, a soft member, and a sensor sheet that detects a change in capacitance. The surface member has an operation area for touch operation. The soft member is disposed between the operation area and the sensor sheet. The sensor sheet has sensor electrodes at positions corresponding to the operation area. When the operation area is pushed in by a touch operation, the surface member and the soft member are displaced toward the sensor sheet, and the capacitance is detected by the sensor electrodes. This is a capacitive input device.

[0008] In one aspect of the present disclosure, the capacitive input device includes a soft member between an operation area where a user performs a touch operation and a sensor sheet having sensor electrodes at positions corresponding to the operation area. And, in one aspect of the present disclosure, the capacitive input device is configured such that when the user pushes in the operation area by a touch operation, the surface member and the soft member are displaced toward the sensor sheet, and the capacitance is detected by the sensor electrodes. Therefore, according to one aspect of the present disclosure, it is possible for the user to tactilely sense that an input has been made to the capacitive input device.

[0009] In one aspect of the present disclosure, the soft member can be configured to have a conductive portion that increases the capacitance value in order to enhance the detection sensitivity in a portion between the operation area and the sensor electrodes.

[0010] When a soft member is provided between the operation area and the sensor electrodes, it is necessary to ensure a longer distance between the operation area and the sensor electrodes by at least that much, so there is a possibility that the sensitivity and detection accuracy of the sensor will decrease. However, in one aspect of the present disclosure, the soft member has a conductive portion in a portion between the operation area and the sensor electrodes. The conductive material constituting the conductive portion generally has a higher dielectric constant than an insulating material. And by increasing the dielectric constant of the soft member, the capacitance value between the finger touching the operation area and the sensor electrodes also increases.

[0011] Therefore, in one aspect of the present disclosure, the capacitive input device can have both a soft touch feeling due to the soft member and conductivity due to the conductive portion. Thus, according to one aspect of the present disclosure, while configuring the capacitive input device to be able to let the user sense by touch that an input has been made, the sensitivity and detection accuracy of its sensor can be improved. Further, when a plurality of operation areas and pairs of sensor electrodes are provided side by side, it is possible to prevent misdetection of an input operation to an operation area different from the operation area where the sensor electrodes are paired.

[0012] In one aspect of the present disclosure, the conductive portion can be configured to be a conductive medium contained in the soft member made of a polymer matrix.

[0013] In one aspect of the present disclosure, the conductive portion is constituted by a conductive medium contained in the polymer matrix. For this reason, according to one aspect of the present disclosure, the conductive portion can be easily formed with respect to the insulating polymer matrix constituting the soft member.

[0014] In one aspect of the present disclosure, the conductive portion can be configured to be an alignment portion in which the conductive medium is aligned in the soft member.

[0015] In one aspect of the present disclosure, the conductive portion is constituted by an alignment portion in which the conductive medium is aligned. For this reason, according to one aspect of the present disclosure, even if the concentration of the conductive medium is lowered, the conductivity between the operation area and the sensor electrode can be easily ensured. Further, since it is possible to lower the concentration of the conductive medium, the flexibility of the soft member can be easily ensured.

[0016] In one aspect of the present disclosure, the soft member can be configured such that the operation area is formed of a light-transmissive material capable of being illuminated.

[0017] In one aspect of the present disclosure, the soft member is made of a light-transmissive material that can illuminate the operation area by an internal light source disposed, for example, near the sensor electrode. Therefore, according to one aspect of the present disclosure, the capacitance input device can clearly show the position of the operation area to the user. Thus, according to one aspect of the present disclosure, the user can surely press the operation area.

[0018] In one aspect of the present disclosure, the operation area has a first operation area and a second operation area, the sensor electrode has a first electrode corresponding to the first operation area and a second electrode corresponding to the second operation area, and the soft member can be configured to have an insulating portion between a first portion located between the first operation area and the first electrode and a second portion located between the second operation area and the second electrode.

[0019] In one aspect of the present disclosure, a first portion located between the paired first operation area and the first electrode and a second portion located between another paired second operation area and the second electrode are separated by an insulating portion. Therefore, according to one aspect of the present disclosure, each sensor electrode can be less affected by areas other than the paired operation areas. Thus, according to one aspect of the present disclosure, it is possible to improve the sensitivity and detection accuracy of the sensor of the capacitance input device and prevent false detection when the capacitance input device has a plurality of operation areas.

[0020] Furthermore, in one aspect of the present disclosure, the insulating portion makes it difficult for light to pass between the first portion and the second portion. Therefore, in one aspect of the present disclosure, light incident on the soft member from near the sensor electrode is likely to reach the operation area paired with the sensor electrode. Thus, according to one aspect of the present disclosure, it is possible to intensively illuminate the operation area paired with the sensor electrode. Further, when a plurality of pairs of the operation area and the sensor electrode are provided side by side, it is possible to prevent the sensor electrode from illuminating an area different from the operation area that forms a pair.

[0021] In one aspect of the present disclosure, the capacitive input device can be further configured to have a first rigid support member on a surface of the sensor sheet opposite to the surface on which the soft member is disposed.

[0022] In one aspect of the present disclosure, the first rigid support member supports the soft member via the sensor sheet. Therefore, according to one aspect of the present disclosure, the shape of the soft member having flexibility and the thin and easily deformable sensor sheet can be maintained. Further, according to one aspect of the present disclosure, when the operation area is pushed in, the rigid support member generates a repulsive force against compressive deformation in the soft member, and the sinking of the soft member and the sensor sheet can be moderately suppressed.

[0023] In one aspect of the present disclosure, the capacitive input device can be further configured to have a second rigid support member having a hole between the surface member and the sensor sheet, and the soft member can be configured to be disposed in the hole.

[0024] In one aspect of the present disclosure, the rigid support member surrounds the soft member disposed in the hole. Therefore, according to one aspect of the present disclosure, a soft touch can be given in the operation area, and a hard touch can be given in the peripheral area around the operation area. Therefore, according to one aspect of the present disclosure, the user can perform an input operation at the correct position without visually observing the capacitive input device.

[0025] In one aspect of the present disclosure, the capacitive input device has an outer surface having a three-dimensional shape, and the operation area can be configured to be formed on the outer surface.

[0026] In one aspect of the present disclosure, the operation area is formed on the outer surface having a three-dimensional shape. Therefore, according to one aspect of the present disclosure, the application range of the capacitive input device can be expanded.

[0027] In one aspect of the present disclosure, the capacitive input device can be configured such that the soft member is formed by laminating a plurality of members.

[0028] In one aspect of the present disclosure, the soft member is formed by laminating a plurality of members. Therefore, according to one aspect of the present disclosure, the thickness, conductivity, etc. of the soft member can be adjusted.

[0029] In one aspect of the present disclosure, the capacitive input device can be configured such that the plurality of members are a combination of an insulating soft member and a conductive soft member.

[0030] In one aspect of the present disclosure, a soft member in which an insulating soft member and a conductive soft member are laminated is used. Therefore, according to one aspect of the present disclosure, the repulsive load against the pressing operation and the sensor sensitivity (DIFF value) can be adjusted without adjusting the blending of the conductive medium of the conductive soft member.

Brief Description of the Drawings

[0031]

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Mode for Carrying Out the Invention

[0032] Hereinafter, one aspect of the present disclosure will be described in detail with reference to the drawings. Note that the embodiments described below do not unduly limit the scope of the claims, and not all of the configurations described in the embodiments are essential as the solution means.

[0033] Regarding the configurations common to the following embodiments, the same reference numerals are given and duplicate explanations in the specification are omitted. Furthermore, duplicate explanations are also omitted for the usage methods and operational effects common to each embodiment. Here, in this specification and the scope of the claims, when described as "first", "second", "third", "fourth", "fifth", and "sixth", they are used to distinguish different components and are not used to indicate a specific order, superiority or inferiority, etc.

[0034] The "capacitive input device" disclosed in this application is an input device that is operated by a user to activate a desired function in an electronic device. The electronic device in which the "capacitive input device" is disposed is provided, for example, in a vehicle, specifically mounted on a vehicle including an automobile, a railway, etc. The "capacitive input device" of the present embodiment is an input device of an electronic device disposed on an in-vehicle interior panel equipped in an automobile as an example.

[0035] The automobile 1 illustrated in FIG. 1 is a right-hand drive vehicle having a driver's seat 2 on the right side in the traveling direction and a passenger seat 3 on the left side in the traveling direction, and a steering wheel 4 on the right side in the traveling direction. Various in-vehicle interior panels are equipped around the driver's seat 2 and the passenger seat 3 of the automobile 1. Examples of the in-vehicle interior panels include, as shown in FIG. 1, a center console 5, a center cluster 6 at the center of the instrument panel, and an armrest portion 7 of the door. The in-vehicle interior panel serves as an operation panel for the electronic device. Here, an example of an embodiment of an operation switch 10 as the "capacitive input device" disposed on the center console 5 will be described with reference to the drawings.

[0036] In this specification and the claims, for convenience, as shown in FIGS. 2, 3, etc., the left-right direction of the operation switch 10 as the "capacitive input device" is described as the X direction, the depth direction (front-rear direction) as the Y direction, and the height direction (vertical direction) as the Z direction. Further, in the operation switch 10 shown in FIG. 3, the side of the surface sheet 20 as the "surface member" exposed on the surface of the center console 5 is described as the upper side (surface layer side) in the Z direction. And the side of the sensor sheet 40 shielded by the surface sheet 20 etc. is described as the lower side (deep layer side) in the Z direction. However, they do not limit the orientation of the arrangement of the operation switch 10, the push-in input operation direction, etc.

[0037] First Embodiment [Figs. 1 to 8]

[0038] As shown in FIG. 3, the operation switch 10 includes a surface sheet 20, a soft member 30, and a sensor sheet 40 that detects a change in capacitance. The operation switch 10 has a layer shape in which the surface sheet 20, the soft member 30, and the sensor sheet 40 are arranged in order from the surface layer side exposed on the surface of the center console 5. When the surface sheet 20 is pushed in from the surface side of the center console 5 by a touch operation by the user, the operation switch 10 is configured such that the surface sheet 20 and the soft member 30 are displaced toward the sensor sheet 40 to make an input. The operation switch 10 of the present embodiment has a surface along a rectangular XY plane that is longer in the X direction than in the Y direction. However, the shape of the surface along the XY plane of the operation switch 10 is not particularly limited.

[0039] The surface sheet 20 forms the outer surface of the operation switch 10 and is the part where the finger I of the user as the "operating body" comes into contact. As shown in FIG. 2, the surface sheet 20 has an operation area 21 and a peripheral area 22. The surface sheet 20 has a thickness (plate thickness) in the Z direction and is in the shape of a thin plate (film, sheet) having a surface along the XY plane. The surface sheet 20 has flexibility that can be deformed such that the operation area 21 is displaced downward in the Z direction when pushed in by a touch operation by the user. The surface sheet 20 may have stretchability.

[0040] The operation area 21 is the part that is pushed in by a touch operation by the user when various functions of the electronic device are selected and executed. That is, the operation area 21 is configured as the input part of the operation switch 10. In the operation switch 10 of the present embodiment, two square operation areas 21 in plan view are provided side by side along the X direction of the surface sheet 20. The operation area 21 may be provided with one or more in the operation switch 10, and the number thereof is not particularly limited. The operation area 21 is surrounded by the peripheral area 22 in plan view.

[0041] On the surface sheet 20, characters, symbols, patterns, etc. indicating the position and function of the operation area 21 are displayed. The operation area 21 may be configured to be illuminated by an internal light source (backlight). When the operation area 21 is illuminated, the characters, symbols, patterns, etc. may be illuminated so as to glow, the periphery thereof may be illuminated so as to glow, or the entire operation area 21 may be illuminated. The decoration such as the position, characters, symbols, patterns, and light-shielding layer of the operation area 21 is provided on at least one of the front and back surfaces of the surface sheet 20 by painting, printing, etc. The position, characters, symbols, patterns, etc. of the operation area 21 may be provided by embossing (concave or convex characters, etc.). By providing uneven shapes, frame shapes, etc. indicating the position of the operation area 21 by embossing, even if the user is groping (blind touch), the user can find the operation area 21 with a fingertip.

[0042] It is preferable that at least the operation area 21 of the surface sheet 20 is soft. By the operation area 21 being soft, when it is pushed in by a touch operation by the user, it can be deformed so as to be displaced downward. On the other hand, it is more preferable that the surface sheet 20 is particularly hard in the peripheral area 22 compared to the soft member 30. By the peripheral area 22 being hard compared to the soft member 30, even if the user is groping, the operation area 21 and the peripheral area 22 can be distinguished. The operation area 21 of the operation switch 10 being soft is easily realized by the surface sheet 20 of the operation area 21 being soft and flexible, and further the soft member 30 below it being soft.

[0043] As the surface sheet 20, a resin film, a resin sheet, a rubber sheet (film), etc., which are flexible materials capable of being bent and deformed, are used. Examples of the resin sheet (film) that can be used for the surface sheet 20 include thermoplastic resins such as polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polycarbonate (PC), acrylic (AC), and polyvinyl chloride (PVC). Examples of the rubber sheet that can be used for the surface sheet 20 include synthetic rubbers (thermosetting elastomers) such as silicone and urethane (polyurethane), and thermoplastic elastomers.

[0044] As other materials for the surface sheet 20, fabric, woven fabric, non-woven fabric, net-like material, mesh sheet, foam sheet, synthetic leather, etc. can also be used. As a result, the surface sheet 20 has a surface on which a texture such as fabric appears. When the fabric or the like has large gaps between the constituent fibers or the like, if a soft resin film such as an elastic urethane film or a thin film is laminated on the lower surface side of the fabric or the like, or a fine non-woven fabric with no gaps is laminated, it is preferable. This can avoid the seepage of the soft member 30 into the surface sheet 20.

[0045] By having a thickness of 0.005 mm or more, the surface sheet 20 can ensure its strength, and by having a thickness of 2 mm or less, it can be easily deformed. Therefore, the surface sheet 20 preferably has a thickness of 0.005 mm to 2 mm, and particularly preferably has a thickness of 0.05 mm.

[0046] The sensor sheet 40 that performs capacitive input is a capacitance sensor that detects the approach of the user's finger I. The sensor sheet 40 has a base sheet 41, a sensor electrode 42, and a protective layer 43.

[0047] The base sheet 41 is a part that forms the basis of the structure of the sensor sheet 40. The base sheet 41 has a thickness (plate thickness) in the Z direction and is in the shape of a thin sheet (sheet) having a surface along the XY plane. The base sheet 41 and the surface sheet 20 are arranged such that the surfaces along their respective XY planes face each other.

[0048] For the base sheet 41, a resin sheet (film) or the like is used as a light-transmissive electrically insulating material. Examples of resin sheets that can be used for the base sheet 41 include thermoplastic resins such as polyethylene terephthalate (PET), polycarbonate (PC), acrylic (AC), and polyimide (PI). When light transmittance is not required for the base sheet 41, it is also possible to use a glass fiber epoxy resin laminate.

[0049] The sensor electrode 42 is an electrode for generating capacitance with the user's finger I. The sensor electrode 42 has a thickness (film thickness) in the Z direction and is in the shape of a film having a surface along the XY plane. The sensor electrode 42 is provided at a position corresponding to the operation region 21 on the surface of the base sheet 41 that faces the surface sheet 20. The sensor electrode 42 may be formed on the surface of the base sheet 41 that faces the surface sheet 20 or on the back surface as long as it is at a position corresponding to the operation region 21. Both sensor electrodes 42 are connected to the sensor control IC via circuit wiring formed on the base sheet 41.

[0050] For the sensor electrode 42, a metal paste such as silver, a conductive coating film such as a carbon paste, a conductive metal foil, etc. can be used. Further, for the sensor electrode 42, PEDOT / PSS (Poly(3,4-EthyleneDiOxyThiophene) / PolyStyrene Sulfonate (dispersion of polyethylene dioxythiophene and polystyrene sulfonic acid)), ITO (Indium Tin Oxide), or a paste containing conductive nanoparticles such as nanoscale fine conductive powder or fine conductive fiber can be used. When the sensor electrode 42 is a transparent conductive film using PEDOT / PSS, a thin film made of ITO, a paste, or a paste containing conductive nanoparticles, it has translucency and can transmit backlight illumination. For the circuit wiring as well, a metal foil, a conductive coating film, etc. can be used in the same manner as the sensor electrode 42.

[0051] The protective layer 43 (resist) is a part that protects the sensor electrode 42 and the circuit wiring. The protective layer 43 has a thickness (plate thickness) in the Z direction and has a thin plate (film) shape with a surface along the XY plane. The protective layer 43 is provided on the surface of the base sheet 41, the sensor electrode 42, and the circuit wiring facing the surface sheet 20 and covers them. Alternatively, when the sensor electrode 42 and the circuit wiring are provided on the back surface of the base sheet 41, it covers them on the back side. For the protective layer 43, an electrically insulating resin film, a resin coating film, etc. are used.

[0052] By having a thickness of 10 μm or more, the sensor sheet 40 can ensure its strength, and by having a thickness of 2500 μm or less, it can ensure translucency and make the operation switch 10 thinner. Therefore, it is preferable that the sensor sheet 40 has a thickness of 10 μm to 2500 μm.

[0053] The soft member 30 is a part that imparts a soft pushing operation feeling to the user who touches the operation area 21. The soft member 30 is disposed between the surface sheet 20 and the sensor sheet 40. The soft member 30 is provided at least between the paired operation area 21 and the sensor electrode 42. The soft member 30 has a thickness (plate thickness) in the Z direction and is in a thin plate shape having a surface along the XY plane. The soft member 30 has flexibility that allows deformation downward of the operation area 21 in response to a touch operation by the user.

[0054] According to the operation switch 10 having such a configuration, when the operation area 21 is pushed in by a touch operation, the surface sheet 20 and the soft member 30 are displaced toward the sensor sheet 40, and the sensor electrode 42 can act to detect capacitance. Thus, the operation switch 10 includes the soft member 30 at least between the paired operation area 21 and the sensor electrode 42. For this reason, the user can obtain a soft touch feeling at the fingertip during the pushing operation of the operation area 21 and can obtain an input feeling. And according to the present embodiment, the user can be made to sense by touch that an input has been made to the operation switch 10.

[0055] The operation switch 10 of the present embodiment is disposed on the left center console 5 with respect to the driver's seat 2 of the right-hand drive vehicle as described above. For this reason, many drivers will push in the operation area 21 with their left hand, which is not their dominant hand. However, in the operation switch 10 of the present embodiment, since a soft pushing operation feeling is imparted to the operation area 21, even if the user uses their left hand and gropes, they can find the operation area 21 and surely perform a touch operation.

[0056] For the soft member 30, rubber-like, gel-like polymer matrices, grease-like soft fillers, soft plates, etc. are used as ultra-low hardness materials. Examples of rubbers that can be used for the soft member 30 include synthetic rubbers such as silicone rubber. Examples of gels that can be used for the soft member 30 include silicone gel, urethane gel, acrylic gel, and hydrogel. Examples of greases that can be used for the soft member 30 include those based on oil such as silicone-based grease.

[0057] An ultra-low hardness member is used for the soft member 30. The soft member 30 preferably has a hardness of A10 or less (measurement value by a type A durometer conforming to JIS K 6253:2012). Further, the soft member 30 more preferably has a hardness with a penetration of 50 or more (measurement value by a penetrometer conforming to JIS K 2207:2006). Further, the soft member 30 more preferably has a hardness of 10 N / mm 2 or less (measurement value conforming to ISO14577-1 and JIS Z 2255:2003). The nanoindentation hardness is obtained from the test force that indents a dent on the test surface and the surface area of the indented dent, and is measured by applying a maximum indentation load (pressing load) of 1 mN, which is the test force, in 10000 msec. Thereby, the soft member 30 can give a flexible indentation operation feeling to the operation region 21.

[0058] By having a thickness of 1 mm or more, the soft member 30 can give a soft touch feeling and an indentation amount to the fingertips of the user who touches the operation region 21, and by having a thickness of 5 mm or less, it is possible to suppress a decrease in the sensitivity of the sensor. For this reason, the soft member 30 preferably has a thickness of 1 mm to 5 mm, and particularly preferably has a thickness of 2 mm to 3 mm. Thus, the soft member 30 requires a thickness of a certain amount or more in order to give a flexible indentation operation feeling to the user who touches the operation region 21.

[0059] When unloaded, the soft member 30 preferably has a shape recovery property of returning to its original shape without permanent (plastic) deformation. The compression set of the material used for the soft member 30 is preferably 70% or less, more preferably 50% or less. Thereby, the soft member 30 is likely to return to its original shape. The compression set can be measured at room temperature after compressing it from its initial thickness by 25% in accordance with JIS K 6262:2013 and leaving it at a temperature of 70°C for 22 hours.

[0060] Here, when the soft member 30 is provided between the operation region 21 and the sensor electrode 42, it is necessary to ensure a longer distance between the operation region 21 and the sensor electrode 42 by at least that much, so there is a possibility that the sensitivity and detection accuracy of the sensor will decrease.

[0061] On the other hand, the soft member 30 more preferably has conductivity in order to suppress a decrease in the sensitivity and detection accuracy of the sensor. For this reason, the soft member 30 can be configured to have a conductive portion 31 in a portion between the operation region 21 and the sensor electrode 42. The conductive material constituting the conductive portion 31 generally has a higher dielectric constant than an insulating material. By increasing the dielectric constant of the soft member 30, the value of the capacitance between the finger I touching the operation region 21 and the sensor electrode 42 also increases. Therefore, since the detection value of the capacitance sensor increases, the sensitivity and detection accuracy of the sensor can be improved.

[0062] In this way, the soft member 30 can be configured to have a conductive portion 31 that increases the capacitance value in order to enhance the detection sensitivity in the portion between the operation region 21 and the sensor electrode 42. The operation switch 10 having such a configuration can have both the flexibility of the soft member 30 and the conductivity of the conductive portion 31. Therefore, according to the present embodiment, while having the configuration of the operation switch 10 that allows the user to sense by touch that an input has been made, the sensitivity and detection accuracy of the sensor can be improved. Further, when a plurality of pairs of the operation region 21 and the sensor electrode 42 are provided side by side, it is possible to prevent misdetection of an input operation on an operation region 21 different from the operation region 21 for which the sensor electrodes 42 are paired.

[0063] The soft member 30 preferably has a volume resistivity of, for example, 1.0×10 6 Ω·cm or less so that the detectability of the capacitance sensor is not hindered, and more preferably has a volume resistivity of 1.0×10 4 Ω·cm or less.

[0064] The conductive portion 31 can be configured to be, for example, a conductive medium contained in the soft member 30 made of a polymer matrix. Thereby, the conductive portion 31 can be easily formed with respect to the insulating polymer matrix constituting the soft member 30.

[0065] Examples of the conductive medium that can be used for the conductive portion 31 include metal powder, carbon powder, graphite powder, conductive polymer powder, ITO powder, and the like. When the soft member 30 is a hydrogel, various electrolytes and the like can also be used as the conductive portion 31. In order to form the conductive portion 31 on the soft member 30, in addition to containing a conductive medium in the polymer matrix, a conductive polymer may be used for the base material itself of the soft member 30.

[0066] The soft member 30 is preferably formed of a light-transmissive material through which the operation area 21 can be illuminated. By configuring the soft member 30 with a light-transmissive material, it becomes possible to illuminate the operation area 21, for example, by an internal light source (backlight) disposed near the sensor electrode 42. Therefore, the operation switch 10 can clearly indicate the position of the operation area 21 to the user. Thus, with such a configuration, the user can surely press in the operation area 21. It is preferable that the soft member 30 has a visible light transmittance of 3% or more and 95% or less, so that the backlight illumination can pass through and the characters, symbols, patterns, etc. displayed in the operation area 21 can be illuminated.

[0067] As the backlight illumination, a light-emitting element such as an LED (Light Emitting Diode) or a light guide such as a light guide plate can be used to illuminate toward the display in the operation area 21. The light-emitting element may be disposed below in the Z direction of the operation area 21 for illumination, or may be disposed far away such as laterally and the light may be guided by a light guide to illuminate the display in the operation area 21.

[0068] It is preferable that the soft member 30 has both conductivity and light-transmittance in the portion between the operation area 21 and the sensor electrode 42. That is, by having conductivity and light-transmittance from the sensor electrode 42 toward the operation area 21 in the soft member 30, even if there is a thickness that gives a soft touch feeling, the detectability of the sensor is not reduced, and an operation switch 10 capable of backlight illumination for the display in the operation area 21 can be realized. By using a light-transmissive material as the material of the soft member 30 and the conductive medium, the soft member 30 can have both conductivity and light-transmittance. By using nano-scale fine powder or fine fibers as the conductive medium, the soft member 30 can also have both conductivity and light-transmittance.

[0069] The conductive portion 31 can be configured to be an orientation portion 32 in which a conductive medium is oriented in the soft member 30. The conductive medium may be, for example, an orientation portion 32 in which spherical particles 33 are oriented so as to be chained in the Z direction (thickness direction), as shown in FIG. 4A. Further, the conductive medium may be, for example, an orientation portion 32 in which fibrous particles 34 are oriented so as to be chained in the Z direction, as shown in FIG. 4B. And the conductive medium may be, for example, an orientation portion 32 in which long fibrous particles 35 are oriented so as to be continuous in the Z direction, as shown in FIG. 4C. Any of these spherical particles 33, fibrous particles 34, and long fibrous particles 35 are electrically connected in the Z direction by conductive media densely arranged in the Z direction compared to the XY direction (plane direction). And in the soft member 30, a conductive portion 31 having conductivity in the Z direction is formed in a portion between the operation region 21 and the sensor electrode 42.

[0070] On the other hand, the conductive medium may be, for example, an orientation portion 32 in which fibrous particles 36 are discontinuously oriented in the Z direction, as shown in FIG. 4D. In this case, before the operation region 21 and the soft member 30 are pushed in by a touch operation, the fibrous particles 36 do not contact each other and are not electrically connected. However, when the operation region 21 and the soft member 30 are pushed in by a touch operation, the fibrous particles 36 contact each other and are electrically connected in the Z direction. Therefore, also in this case, a conductive portion 31 having conductivity in the Z direction is formed in the soft member 30 in a portion between the operation region 21 and the sensor electrode 42.

[0071] The conductive medium is oriented in the Z direction to form the oriented portion 32, and the conductive media are chained and continuously conductively connected to each other. Thus, even when the concentration of the conductive medium is low, conductivity between the operation region 21 and the sensor electrode 42 can be easily ensured. In the soft member 30 in which the conductive portion 31 is formed by the oriented portion 32 in this way, since conductivity is ensured, it is possible to sparsely arrange the conductive medium in the XY direction. And since it is possible to sparsely arrange the conductive medium, which tends to have lower translucency than, for example, a polymer matrix that is the main material of the soft member 30, in the XY direction, the soft member 30 can also have high translucency in the Z direction. Furthermore, since the concentration of the conductive medium can be lowered, the flexibility of the soft member 30 can be easily ensured, and the soft member 30 can also have an ultra-low hardness. The orientation of the conductive medium in the Z direction can be performed by fixing the position in a state where the direction and chained arrangement of the conductive medium are determined using a force such as a magnetic field, an electric field, or a flow field.

[0072] For the soft member 30, a material that has high conductivity and translucency in the Z direction and low conductivity and translucency in the XY direction, that is, a material having anisotropy in conductivity and translucency can be used. The soft member 30 preferably has a volume resistivity of, for example, 1.0×10 8 Ω·cm or more in the XY direction. Since the soft member 30 has relatively low conductivity in the XY direction, the capacitance sensor is less likely to erroneously detect a touch operation on an operation region 21 different from the operation region 21 paired with the sensor electrode 42. The soft member 30 preferably has a visible light transmittance of less than 3%, for example, in the XY direction. Since the soft member 30 has relatively low translucency in the XY direction, it is difficult to irradiate an unintended operation region 21, and only the target operation region 21 can be brightly irradiated to stand out.

[0073] Note that the soft member 30 may be configured such that a conductive soft member having the conductive portion 31 and an insulating soft member not having the conductive portion 31 are laminated in the Z direction. In that case, the conductive soft member and the insulating soft member may be alternately laminated, or either one may be continuously laminated.

[0074] Furthermore, the operation switch 10 can be configured to include a structure for holding the surface sheet 20, the soft member 30, and the like. For example, the operation switch 10 can be configured to have a first rigid support member 51 on a surface opposite to the arrangement surface of the soft member 30 in the sensor sheet 40. The first rigid support member 51 has a thickness (plate thickness) in the Z direction and is in the shape of a thin plate (sheet) having a surface along the XY plane. The first rigid support member 51 has rigidity capable of supporting the soft member 30 and the sensor sheet 40 that tend to be displaced downward in the Z direction.

[0075] In this way, the first rigid support member 51 supports the soft member 30 via the sensor sheet 40. Therefore, the first rigid support member 51 can hold the shape of the soft member 30 having flexibility and the thin and easily deformable sensor sheet 40 and prevent them from flowing out. Furthermore, when the operation area 21 is pushed in, the first rigid support member 51 can generate a repulsive force against compressive deformation in the soft member 30, appropriately suppress the sinking of the soft member 30 and the sensor sheet 40, and maintain a desired soft touch feeling.

[0076] First Modification Example [Fig. 5]

[0077] Furthermore, as shown in FIG. 5, the operation switch 10A can have, for example, a second rigid support member 52 having a hole between the surface sheet 20 and the sensor sheet 40, and the soft member 30 can be configured to be arranged in the hole. The second rigid support member 52 has a thickness (plate thickness) in the Z direction and is in the shape of a thin plate (sheet) having a surface along the XY plane. And, in the second rigid support member 52, a hole penetrating along the Z direction is formed at a position corresponding to the sensor electrode 42. That is, here, the operation switch 10A has an arrangement in which the soft members 30 are individually arranged on the sensor electrodes 42 and surrounded by the frame-shaped second rigid support member 52. As a result, the soft member 30 is arranged only between the operation area 21 and the sensor sheet 40.

[0078] Thus, the second rigid support member 52 surrounds the soft member 30 disposed in the hole. Therefore, the second rigid support member 52 can position the soft member 30 from the side. Further, the second rigid support member 52 can provide a soft touch feeling in the operation area 21 and a hard touch feeling in the peripheral area 22 around the operation area 21. Therefore, according to one aspect of the present disclosure, the user can perform an input operation at the correct position without visually observing the operation switch 10A.

[0079] Second Modification Example [Fig. 6]

[0080] Furthermore, as shown in FIG. 6, the operation switch 10B can be configured to have a third rigid support member 53 on the facing surface with the soft member 30 in the peripheral area 22 of the surface sheet 20, for example. The third rigid support member 53 has a thickness (plate thickness) in the Z direction and is in the shape of a thin plate (sheet) having a surface along the XY plane. A hole penetrating in the Z direction is formed in the third rigid support member 53 at a position corresponding to the operation area 21. That is, the operation switch 10B here is configured such that the peripheral area 22 of the surface sheet 20 and the third rigid support member 53 are laminated. As a result, in the peripheral area 22, a member harder than the soft member 30 is thicker in the Z direction than in the operation area 21.

[0081] Thus, the third rigid support member 53 hardens the peripheral area 22 by increasing the thickness of the hard member in the peripheral area 22. Therefore, the third rigid support member 53 can provide a soft touch feeling in the operation area 21 and a hard touch feeling in the peripheral area 22 around the operation area 21. Therefore, according to one aspect of the present disclosure, the user can perform an input operation at the correct position without visually observing the operation switch 10B. It is preferable that the third rigid support member 53 has a thickness of, for example, 0.5 mm so that the peripheral area 22 can be hardened.

[0082] For the first rigid support member 51 and the second rigid support member 52, a rigid thermoplastic resin, a rigid thermosetting resin, synthetic rubber, a thermoplastic elastomer, etc. can be used. The materials used for the first rigid support member 51 and the second rigid support member 52 are preferably electrically insulating. In particular, for the first rigid support member 51, it is preferable that the material has translucency so that backlight illumination can be transmitted through it.

[0083] Note that the first rigid support member 51 may be combined with either the second rigid support member 52 or the third rigid support member 53.

[0084] Third Modification Example [Figs. 7 to 8]

[0085] As shown in FIGS. 7 and 8, the operation switch 10C according to the third modification can be configured to have an insulating groove 37 as an "insulating portion" for preventing false detection with an adjacent operation region 21. Here, the operation region 21 has a first operation region 21A and a second operation region 21B. Further, the sensor electrode 42 has a first electrode 42A corresponding to the first operation region 21A and a second electrode 42B corresponding to the second operation region 21B. And the soft member 30 has an insulating groove 37 that forms a gap between a first portion 38A located between the first operation region 21A and the first electrode 42A and a second portion 38B between the second operation region 21B and the second electrode 42B. The insulating groove 37 has a groove width in the X direction and has a rectangular cross section in side view.

[0086] The first portion 38A positioned between the paired first operation region 21A and the first electrode 42A and the second portion 38B positioned between the paired second operation region 21B and the second electrode 42B are separated by the insulating groove 37. The conductivity between the first portion 38A and the second portion 38B separated by the insulating groove 37 is extremely low. Therefore, each sensor electrode 42 can be less affected by regions other than the paired operation regions 21. Thus, according to the configuration in which the soft member 30 has the insulating groove 37, the sensitivity and detection accuracy of the sensor of the operation switch 10C can be improved, and false detection can be prevented when the operation switch 10C has a plurality of operation regions 21.

[0087] Furthermore, the insulating groove 37 makes it difficult for light to pass between the first portion 38A and the second portion 38B. Therefore, light incident on the soft member 30 from the vicinity of the sensor electrode 42 easily reaches the operation region 21 paired with the sensor electrode 42. Thus, according to the configuration in which the soft member 30 has the insulating groove 37, the operation region 21 paired with the sensor electrode 42 can be intensively illuminated. Furthermore, when a plurality of pairs of the operation region 21 and the sensor electrode 42 are provided side by side, it is possible to prevent the operation region 21 other than the operation region 21 paired with the sensor electrode 42 from being illuminated.

[0088] The insulating groove 37 as an "insulating portion" that separates the first portion 38A and the second portion 38B can be made of a material different from the soft member 30, not limited to a gap. For the "insulating portion", an electrically insulating gel, rubber, resin, etc. can be used. Even with such a "insulating portion" made of such materials, each sensor electrode 42 can be less affected by areas other than the paired operation regions 21. Therefore, it is possible to improve the sensitivity and detection accuracy of the sensors of the operation switch 10C, and to prevent false detection when the operation switch 10C has a plurality of operation regions 21. Similarly, even with the "insulating portion" made of an electrically insulating gel, rubber, resin, etc., the operation region 21 paired with the sensor electrode 42 can be intensively illuminated. Further, when a plurality of pairs of the operation region 21 and the sensor electrode 42 are provided side by side, it is possible to prevent the sensor electrode 42 from illuminating an operation region 21 different from the operation region 21 that is paired.

[0089] Second Embodiment [Figs. 9 to 13]

[0090] The operation switches 10, 10A, 10B, and 10C as "capacitive input devices" are not limited to being embedded below the flat surface sheet 20 without unevenness, and can also be applied to an electronic device having an outer surface in a three-dimensional shape and having an input portion. That is, the operation switch 10D of the present embodiment has a three-dimensional outer surface, and the operation region 21 is formed on the outer surface. As shown in FIGS. 9 and 10, the surface sheet 20 has a cylindrical three-dimensional surface. And the operation region 21 is provided on the top surface of the cylindrical shape. Here, the sensor sheet 40 is arranged upside down compared to the first embodiment. That is, in the sensor sheet 40, the base material sheet 41 is arranged to face the soft member 30. A disk-shaped first rigid support member 51 is provided on the surface of the sensor sheet 40 opposite to the surface facing the soft member 30.

[0091] Thus, in this embodiment, the operation area 21 is formed on the outer surface of a three-dimensional shape. Therefore, according to this embodiment, the applicable range of the operation switch 10 can be expanded. The three-dimensional shape on which the operation area 21 is provided is not limited to a cylindrical shape, and can be provided on various three-dimensional shapes such as, for example, a convex surface, a concave surface, a prismatic shape, a frustum of a cone shape, a frustum of a pyramid shape, and an annular shape.

[0092] Fourth Modification Example [Figs. 11 to 13]

[0093] The outer surface on which the operation area 21 is formed is not limited to the top surface of the three-dimensional shape. In the operation switch 10E according to the fourth modification example shown in FIGS. 11 and 12, the operation area 21 is provided on the side surface (outer peripheral surface) of a cylindrical shape. The operation areas 21 are provided at four locations at 90° intervals in the circumferential direction. A base material sheet 41 is provided concentrically with the surface sheet 20 inward in the radial direction of the operation area 21. And sensor electrodes 42 are provided at positions corresponding to the respective operation areas 21 in the radial direction on the inner peripheral surface of the base material sheet 41. A soft member 30 is provided between the surface sheet 20 and the base material sheet 41.

[0094] As shown in FIG. 13A, the soft member 30 may be continuously arranged in a cylindrical shape. On the other hand, as shown in FIG. 13B, the soft member 30 may be provided at four locations at 90° intervals in the circumferential direction corresponding to the operation area 21 and the sensor electrode 42. In this case, a frame-shaped fourth rigid support member 54 is provided between adjacent soft members 30.

[0095] Thus, in this embodiment, the operation area 21 is formed on the side surface (outer peripheral surface) of a three-dimensional shape. Therefore, according to this embodiment, the applicable range of the present disclosure can be expanded to an input device of an electronic device that performs a pushing operation in a direction intersecting the direction from the top surface downward like the operation switch 10E.

[0096] The sensor sheet 40 here is arranged with the front and back reversed compared to the first embodiment. That is, in the sensor sheet 40, the base material sheet 41 is arranged facing the soft member 30. However, the sensor sheet 40 of this embodiment may be arranged in the same direction as the first embodiment.

[0097] Third Embodiment [Figs. 14 to 17]

[0098] The "capacitive input device" can also be configured to widely cover the outer surface of the electronic device with the surface sheet 20 so that its surface is continuously connected to the surrounding exterior member 60 (housing). That is, as shown in FIG. 14 and the like, the surface sheet 20 of this embodiment continuously covers all the surfaces between the arranged operation switches 10 (displaying the operation switch 10F and the operation switch 10H) and the exterior member 60, and constitutes the outer surface of the electronic device.

[0099] The operation switch 10F according to the third embodiment shown in FIG. 15 is arranged so as to protrude from the outer surface of the exterior member 60 with a slight gap at the edge of the exterior member 60. The sensor electrode 42 is not shown. The operation switch 10F is configured such that the entire top surface of the protruding surface sheet 20 becomes the operation area 21. The soft member 30 is in a disc shape. And the soft member 30 is supported by the top surface of the fifth rigid support member 55 so as to be entirely arranged on the back surface side of the surface sheet 20 in the area of the operation switch 10F. The sensor sheet 40 is provided on the surface of the fifth rigid support member 55 opposite to the surface on which the soft member 30 is arranged. Or the sensor sheet 40 may be provided between the fifth rigid support member 55 and the soft member 30.

[0100] Fifth Modification Example [Fig. 16]

[0101] The soft member 30 of the operation switch 10G according to the fifth modification example shown in FIG. 16 has a hollow cylindrical shape. The surface sheet 20 is directly supported by the fifth hard support member 55. And the soft member 30 is supported by the outer peripheral surface of the fifth hard support member 55 so as to be disposed entirely on the inner peripheral surface side of the side surface of the surface sheet 20.

[0102] Sixth Modification Example [Fig. 17]

[0103] The operation switch 10H according to the sixth modification example shown in FIG. 17 is arranged so as not to protrude from the outer surface of the exterior member 60 through a slight gap at the edge of the exterior member 60. That is, the surface sheet 20 is provided to be flat in both the regions of the operation switch 10H and the exterior member 60. The soft member 30 has a rectangular flat plate shape. And the soft member 30 is supported by the top surface of the sixth hard support member 56 so as to be disposed entirely on the back surface side of the surface sheet 20 in the region of the operation switch 10H. A sensor sheet 40 is provided on the surface of the sixth hard support member 56 opposite to the surface on which the soft member 30 is disposed. Or a sensor sheet 40 may be provided between the sixth hard support member 56 and the soft member 30.

[0104] In the operation switch 10F etc. of the present embodiment, the operation switch 10F etc. and the exterior member 60 are continuously covered by a single surface sheet 20. Therefore, according to the operation switch 10F etc. of the present embodiment, a seamless appearance without gaps and joints between the surface members can be achieved.

[0105] If the surface sheet 20 is soft or sufficiently thin, the surface sheet 20 in the gap between the operation switch 10F etc. and the exterior member 60 can be stretched or bent to push in the operation region 21 of the operation switch 10F etc. against the exterior member 60. However, since the surface sheet 20 at the location adjacent to the soft member 30 can obtain a pressing tactile sensation when the soft member 30 is crushed, it is not necessary to configure the surface sheet 20 to be deformed against the exterior member 60 by the pushing operation of the operation region 21.

[0106] In the "capacitive input device" disclosed in this application, the configurations shown in each embodiment and modification can be freely combined within a range where no contradiction occurs. For example, the second rigid support member 52, the third rigid support member 53, etc. in the first embodiment may be combined with the configuration of the second embodiment.

[0107] Although each embodiment has been described in detail as above, those skilled in the art will easily understand that many modifications are possible without substantially departing from the novel matters and effects of the present invention. Therefore, all such modifications are intended to be included within the scope of the present invention.

Example

[0108] Examples are shown below to explain the operation switch 10 etc. as the "capacitive input device" in this embodiment in more detail and specifically. However, this embodiment is not limited to the following examples.

[0109] What was used in the example was the operation switch 10 in which the surface sheet 20 shown in FIG. 3 etc., the sensor sheet 40, and the soft member 30 were arranged therebetween. For the surface sheet 20, a soft polyurethane sheet with a thickness of 0.05 mm was used. For the sensor sheet 40, what covered a plurality (two or more) of sensor electrodes 42 and circuit wirings formed on the base material sheet 41 with the protective layer 43 was used. As the base material sheet 41, a PET sheet with a thickness of 0.1 mm was used. The plurality of sensor electrodes 42 are conductive coating films formed using PEDOT / PSS conductive paste. Further, the circuit wiring is a conductive coating film formed using a silver powder-containing paste. As the protective layer 43, an electrically insulating resin coating film was formed.

[0110] As the soft member 30, for each of the configuration examples shown in Table 1, a member formed of one material or a member formed by combining members of different materials was used. The soft member 30 here was provided so as to cover across two adjacent sensor electrodes 42. The total thickness of the soft member 30 was adjusted to be 3 mm in total.

[0111] The volume resistivity [Ω·cm] in the thickness direction (Z direction) and the plane direction (XY direction) of each of the fabricated soft members 30 was measured. The volume resistivity was obtained by measuring the electrical resistance values [Ω] in the thickness direction and the plane direction of the soft member 30 and then multiplying each by the cross-sectional area and dividing by the length. For the measurement of the electrical resistance value, a digital multimeter (R6552 manufactured by ADVANTEST) was used. When measuring the electrical resistance value of a member having a thickness of 1.0 mm as in Configuration Example 2 described later, five sheets were stacked in the thickness direction so that the total thickness was 0.5 cm, and then the electrical resistance value was measured.

[0112] Each of the obtained operation switches 10 was placed on the measurement table S as shown in FIG. 18, and various measurements were performed. For each operation switch 10, a pusher P imitating a human finger I as an "operating body" was pressed against the center of each sensor electrode 42 from above as a measuring element, and the repulsive load [N] with respect to the pushing distance (stroke) [mm] and the sensor sensitivity of each sensor electrode 42 were measured. The pusher P was made of conductive rubber having a hardness of A60 and had a cylindrical shape with a diameter of 6 mm. The repulsive load was detected by a load cell connected to the pusher P having the above-described conductive rubber at its tip.

[0113] Here, in this embodiment, a wide variety of materials are used for the soft member 30. Therefore, the pushing distance for each soft member 30 was 1.0 mm, and the repulsive load at the time when the soft member 30 was compressed by 33% was defined as an index of the unified hardness in this embodiment. And it has been previously confirmed that when the repulsive load at this 33% compression is 6 N or less, it is preferable as a material for the soft member 30 with a soft touch at a low load.

[0114] The sensor sensitivity of each sensor electrode 42 was measured by connecting the terminal of the sensor sheet 40 that conducts with the sensor electrode 42 to a control IC (Integrated Circuit). As the control IC, a PSoC (registered trademark) IC (microcontroller CY8C24894 56-pin QFN (Quad Flat Non-leaded package) manufactured by Cypress Semiconductor Corporation) was used. For the parameters of the PSoC IC, settings were used with a Resolution of 12 bits (4096), a Ref Value of 2, a Prescaler Period of 3, a Scanning Speed of Normal, and a PRS Polynomial (Pseudo Random Sequence Polynomial) of Short.

[0115] As an index indicating the sensor sensitivity of each sensor electrode 42, a DIFF value [-] based on the change amount of capacitance was used. Here, the DIFF value is the difference value between the detected value (RAW value) of capacitance and the baseline value (DIFF value = measured value (RAW value) - baseline value). For each operation switch 10, the DIFF value of the sensor electrode 42 corresponding to the operation region 21 where the pusher P is located and the DIFF value of another sensor electrode 42 adjacent to the sensor electrode 42 to be operated were measured.

[0116] (Configuration Example 1)

[0117] In Configuration Example 1, a non-conductive gel was used as the insulating soft member 30 as an insulating soft member. As the non-conductive gel, a two-component addition reaction type silicone gel (TSE3070 manufactured by Momentive) was used. The soft member 30 in Configuration Example 1 is an insulating silicone gel having an electrical resistivity of 1×10 15 Ω·cm and can be regarded as having substantially the same resistivity values in the thickness direction and the surface direction. Further, this silicone gel had a penetration of 65 after curing and a low hardness. And this silicone gel was colorless and transparent and had good light transmittance.

[0118] (Configuration Example 2)

[0119] In Configuration Example 2, a conductive gel was used as the soft member 30. As the conductive gel, an adhesive pad for low-frequency therapy devices (HV-PAD-3 manufactured by Omron Healthcare Co., Ltd.) using a conductive hydrogel was used. A non-woven fabric was used as the intermediate base material for this hydrogel. The electrical resistance value of the soft member 30 in Configuration Example 2 was 3×10 5 Ω, and the volume resistivity was 6×10 5 Ω·cm. The values of the volume resistivity in the thickness direction and the surface direction could be regarded as substantially the same. And this hydrogel had good light transmissibility. The soft member 30 in Configuration Example 2 was arranged by laminating three sheets of the same kind of sheet-shaped adhesive pads having a thickness of 1.0 mm. Therefore, the overall thickness of the soft member 30 became 3 mm.

[0120] (Configuration Example 3)

[0121] In Configuration Example 3, the non-conductive gel of Configuration Example 1 and the conductive gel of Configuration Example 2 were combined and used for the soft member 30. Here, a soft member 30 was used in which the conductive gel was arranged in the upper layer on the side of the surface sheet 20 and the non-conductive gel was arranged in the lower layer on the side of the sensor electrode 42 and laminated. Since the thickness of the silicone gel was formed to be 2 mm and a hydrogel having a thickness of 1.0 mm was laminated thereon, the overall thickness of the soft member 30 in Configuration Example 3 became 3 mm. The volume resistivity of the soft member 30 in Configuration Example 3 was 1×10 15 Ω·cm. The values of the volume resistivity in the thickness direction and the surface direction on the lower layer side where the non-conductive gel was arranged could be regarded as substantially the same. Since the volume resistivity on the lower layer side of the soft member 30 was a high value in this way, the influence on the sensitivity to the adjacent sensor electrode 42 was reduced.

[0122] (Configuration Example 4)

[0123] In Configuration Example 4, as the soft member 30, an anisotropic conductive gel in which a conductive medium is blended in an insulator (non-conductor) base material and the conductive medium is oriented in the thickness direction of the soft member 30, so that higher conductivity is imparted in the thickness direction than in the surface direction of the soft member 30, was used. As the base material of the anisotropic conductive gel, the same two-component addition reaction type silicone gel (TSE3070 manufactured by Momentive) as in Configuration Example 1 described above was used. As the conductive filler which is a substance for imparting conductivity, silver-plated nickel powder with an average particle size of 30 μm formed by plating silver on the base material nickel was used.

[0124] The soft member 30 in Configuration Example 4 was formed by blending silver-plated nickel powder in an insulating silicone gel and subjecting it to crosslinking and curing after applying a magnetic field in a certain direction. As a result, as the soft member 30 in Configuration Example 4, an anisotropic conductive silicone gel sheet having an orientation portion 32 in which silver-plated nickel particles are continuously arranged in the thickness direction in a sheet shape having a thickness of 3 mm was obtained. And, the soft member 30 in Configuration Example 4 has a volume resistivity of 1.5×10 -1 Ω·cm in its thickness direction and a volume resistivity of 1×10 8 Ω·cm in its surface direction.

[0125] (Configuration Example 5)

[0126] In Configuration Example 5, as the soft member 30, an insulating rubber of an insulator (non-conductor) was used. As the insulating rubber, a two-component liquid silicone rubber (KE-1950-10A / B manufactured by Shin-Etsu Chemical Co., Ltd.) cured by an addition reaction was used. The soft member 30 in Configuration Example 5 is an insulating silicone rubber having an electrical insulation with a volume resistivity of 1×10 15 Ω·cm, and the values of the volume resistivity in its thickness direction and surface direction can be regarded as substantially the same. Further, this silicone rubber has a hardness of A10 and is of low hardness. And, the thickness of the soft member 30 in Configuration Example 5 was adjusted to be 3 mm.

[0127] (Comparative Example)

[0128] In the comparative example, as the member corresponding to the soft member 30, insulating rubber of an insulator (non-conductor) was used. As the insulating rubber, a two-component liquid silicone rubber (KE-1950-20A / B manufactured by Shin-Etsu Chemical Co., Ltd.) cured by an addition reaction was used. In the comparative example, the hardness of the member corresponding to the soft member 30 in the above-described Configuration Example 5 was A20. Otherwise, it was the same as in the above-described Configuration Example 5.

[0129]

Table 1

[0130] Repulsive Load and DIFF Value

[0131] (Configuration Example 1)

[0132] In Configuration Example 1, the repulsive load with respect to the pushing operation changed to a low value. That is, the repulsive load in Configuration Example 1 was only 0.1 N, which was much lower than 6 N even when the pushing distance was 1.0 mm (33% compression), and the low-load state was maintained. Therefore, according to Configuration Example 1, it was found that a flexible pushing operation feeling was imparted.

[0133] On the other hand, in Configuration Example 1, the DIFF value became extremely high when the pushing distance exceeded a predetermined amount. That is, the DIFF value in Configuration Example 1 was 57.4 when the pushing distance was 0.2 mm, and did not reach 100 even when the pushing distance was 0.5 mm, whereas it became 447 when the pushing distance was 1.0 mm. Further, although it was at a lower level compared with the sensor electrode 42 of the operation target, the DIFF value was also detected at the other adjacent sensor electrodes 42. However, by setting a threshold value such as a DIFF value of 100 or 40% of the maximum value of the DIFF value, only the operation on the desired sensor electrode 42 can be detected.

[0134] From the above results, it was found that configuration example 1 provides an operation switch 10 that has a soft feel when initially pressed and detects the operation when pressed to a certain extent, and has good pressure sensitivity characteristics.

[0135] (Configuration Example 2)

[0136] In Configuration Example 2, the repulsive load increased in value in a sensitive response to the pressing distance. That is, the repulsive load in Configuration Example 2 was 0.2 N when the pressing distance was 0.2 mm, and was 1.8 N when the pressing distance was 1.0 mm (33% compression). It was presumed that the reason the repulsive load of Configuration Example 2 was higher than that of Configuration Example 1 was due to the influence of the nonwoven fabric contained in the soft member 30. However, the repulsive load of Configuration Example 2 when the soft member 30 was compressed 33% was significantly lower than 6 N. Therefore, it was found that Configuration Example 2 maintained a low repulsive load against the pressing operation, and had a soft and pleasant feel.

[0137] On the other hand, in the configuration example 2, the DIFF value also became high in response to the pressing distance. That is, the DIFF value in the configuration example 2 was already 95 when the pressing distance was 0.2 mm, and became 440 when the pressing distance became 1.0 mm. Therefore, it was found that the pressing operation can be detected even with a small pressing distance according to the configuration example 2. Furthermore, in the configuration example 2, the DIFF value was hardly detected in other adjacent sensor electrodes 42.

[0138] From the above results, it was found that configuration example 2 enables highly reliable detection in which an operation is detected only in a narrow range corresponding to a desired sensor electrode 42, that is, only at the pressed location, and not at other adjacent sensor electrodes 42. It was also found that this high reliability can be achieved even in a range where the pressing distance is small.

[0139] (Configuration Example 3)

[0140] In Configuration Example 3, the repulsive load changed over time at a lower value compared to Configuration Example 2. That is, the repulsive load in Configuration Example 3 was significantly lower than 6N, such that it was 0.04N when the pushing distance was 0.2 mm and 0.5N even when the pushing distance reached 1.0 mm. Therefore, according to Configuration Example 3, it was found that the repulsive load could be reduced, and a flexible pushing operation feeling was imparted.

[0141] On the other hand, in Configuration Example 3, the DIFF value became high by responding sensitively to the pushing distance. That is, the DIFF value in Configuration Example 3 had already reached 210 when the pushing distance was 0.2 mm, and it became 503 when the pushing distance reached 1.0 mm. Therefore, according to Configuration Example 3, it was found that the pushing operation could be detected even with a small amount of pushing distance. Furthermore, in Configuration Example 3, the DIFF value in the other adjacent sensor electrodes 42 was maintained at 100 or less.

[0142] From the above results, in Configuration Example 3, compared to Configuration Example 2 using a conductive gel for the soft member 30, the repulsive load against the pushing operation could be reduced. Furthermore, in Configuration Example 3, compared to Configuration Example 1 using a non-conductive gel for the soft member 30, it was found that the DIFF value showed a high value even at the initial stage of pushing with a small pushing distance, and the pushing operation could be detected. Therefore, according to Configuration Example 3, it was shown that the repulsive load against the pushing operation and the sensor sensitivity (DIFF value) could be adjusted by the combination of the members laminated on the soft member 30, without adjusting the blending of the conductive medium in a conductive gel such as in Configuration Example 2.

[0143] (Configuration Example 4)

[0144] In Configuration Example 4, the repulsive load was a higher value compared to Configuration Example 1. That is, the repulsive load in Configuration Example 4 was 3.4 N when the pushing-in distance was 1.0 mm (33% compression). It was presumed that the reason the repulsive load of Configuration Example 4 was a higher value compared to that of Configuration Example 1 was due to the influence of the conductive medium contained in the soft member 30. However, the repulsive load at 33% compression of the soft member 30 in Configuration Example 4 was far below 6 N. Therefore, according to Configuration Example 4, it was found that the repulsion against the pushing-in operation was maintained at a low load state, and the touch feeling was soft and good.

[0145] On the other hand, in Configuration Example 4, the DIFF value became a high value by responding sensitively to the pushing-in distance. That is, the DIFF value in Configuration Example 4 was already 291 when the pushing-in distance was 0.2 mm, and it became 525 when the pushing-in distance reached 1.0 mm. Therefore, according to Configuration Example 4, it was found that even with a small amount of pushing-in distance, the pushing-in operation could be detected. Furthermore, in Configuration Example 4, substantially no DIFF value was detected in the other adjacent sensor electrodes 42.

[0146] From the above results, in Configuration Example 4, since the soft member 30 has anisotropic conductivity, it was found that for the operation region 21 where the pushing-in operation was performed, the alignment portion 32 extended and the sensor sensitivity of the sensor electrode 42 located in the thickness direction of the soft member 30 with a low volume resistivity was high. On the other hand, in Configuration Example 4, it was found that the sensor sensitivity of the other sensor electrodes 42 adjacent to the sensor electrode 42 of the operation target was extremely low. Therefore, in Configuration Example 4, it was found that it was possible to perform a more reliable detection that detected the operation only in a narrow range corresponding to the desired sensor electrode 42, that is, only at the pushed-in location, and did not detect it in the other adjacent sensor electrodes 42. And it was found that this high reliability was also realized in a range where the pushing-in distance was small.

[0147] (Configuration Example 5)

[0148] In Configuration Example 5, the repulsive load was a high value compared to other configuration examples. That is, the repulsive load in Configuration Example 5 was 5.2 N when the pushing distance was 1.0 mm (33% compression). However, the repulsive load at 33% compression of the soft member 30 in Configuration Example 5 was 6 N or less. Therefore, according to Configuration Example 5, it was found that the repulsion against the pushing operation was maintained at a low load state, and the touch feeling was soft and good.

[0149] On the other hand, in Configuration Example 5, the DIFF value became extremely high when the pushing distance exceeded a predetermined amount. That is, the DIFF value in Configuration Example 5 was 65.6 when the pushing distance was 0.2 mm, whereas it became 447 when the pushing distance was 1.0 mm. Further, although it was at a lower level compared to the sensor electrode 42 of the operation target, DIFF values were also detected in other adjacent sensor electrodes 42. However, by setting a threshold value such as DIFF value 100 or 40% of the maximum value of the DIFF value, only the operation on the desired sensor electrode 42 can be detected.

[0150] From the above results, it was found that in Configuration Example 5, the repulsive load against the pushing operation was low and the touch feeling was soft, and by setting an appropriate threshold value for the DIFF value, the pushing operation can be reliably detected.

[0151] (Comparative Example)

[0152] In the comparative example, the repulsive load was a high value compared to each configuration example. That is, the repulsive load in the comparative example was 9.3 N when the pushing distance was 1.0 mm (33% compression). Therefore, the repulsive load at 33% compression of the member corresponding to the soft member 30 in the comparative example did not become 6 N or less. Therefore, in the comparative example, the repulsion against the pushing operation was not maintained at a low load state, and the touch feeling could not be made soft.

[0153] The following findings were obtained from the above examples.

[0154] From the results of Configuration Example 2 and Configuration Example 4, when a conductive gel is used as the soft member 30, the sensor sensitivity of the sensor electrode 42 corresponding to the operation region 21 increases, and conversely, it was confirmed that the influence on other sensor electrodes 42 adjacent to the sensor electrode 42 of the operation target is small. Further, from the results of Configuration Example 4, when a conductive gel having anisotropy with higher conductivity in the thickness direction than in the plane direction is used as the soft member 30, this tendency becomes even greater, and it was confirmed that only the sensor electrode 42 corresponding to the operation region 21 reacts.

[0155] On the other hand, from the results of Configuration Example 1, Configuration Example 3, and Configuration Example 5, it was confirmed that when a non-conductive material is present in the layer configuration of the soft member 30, other sensor electrodes 42 adjacent to the sensor electrode 42 of the operation target may react simultaneously. And from the results of Configuration Example 1, when a non-conductive gel is used as the soft member 30, the sensor sensitivity does not increase and it is difficult to detect in a region where the repulsive load is low. Moreover, it was found that the tendency for another adjacent sensor electrode 42 to react simultaneously increases.

Explanation of Signs

[0156] 1 Automobile 2 Driver's seat 3 Passenger seat 4 Steering wheel 5 Center console 6 Center cluster 7 Door armrest part 10 Operation switch (capacitive input device) 10A Operation switch (first modification example) (capacitive input device) 10B Operation switch (second modification example) (capacitive input device) 10C Operation switch (third modification example) (capacitive input device) 10D Operation switch (second embodiment) (capacitive input device) 10E Operation switch (fourth modification example) (capacitive input device) 10F Operation switch (third embodiment) (capacitive input device) 10G Operation Switch (Fifth Modified Example) (Capacitive Input Device) 10H Operation Switch (Sixth Modified Example) (Capacitive Input Device) 20 Surface Sheet (Surface Member) 21 Operation Region 21A First Operation Region 21B Second Operation Region 22 Peripheral Region 30 Soft Member 31 Conductive Portion 32 Alignment Portion 33 Spherical Particles 34 Fiber-shaped Particles 35 Long Fiber-shaped Particles 36 Fiber-shaped Particles 37 Insulation Groove (Insulation Portion) 38A First Portion 38B Second Portion 40 Sensor Sheet 41 Base Sheet 42 Sensor Electrode 42A First Electrode 42B Second Electrode 43 Protection Layer 51 First Rigid Support Member 52 Second Rigid Support Member 53 Third Rigid Support Member 54 Fourth Rigid Support Member 55 Fifth Rigid Support Member 56 Sixth Rigid Support Member 60 Exterior Member I Finger (Operating Body) P Pusher S Measuring Table X Left-Right Direction Y Front-Rear Direction Z Height Direction, Up-Down Direction

Claims

1. A surface member; A soft member; a sensor sheet for detecting a change in capacitance; the surface member has an operation area for touch operation and a peripheral area surrounding the operation area, the soft member is disposed between the operation area and the sensor sheet, the sensor sheet has a sensor electrode at a position corresponding to the operation area, When the operation area is pressed by a touch operation, at least one of the surface member and the soft member is compressively deformed toward the sensor sheet, whereby the surface member is displaced toward the sensor sheet, and the capacitance is detected by the sensor electrode. The peripheral region is harder than the operation region. Capacitive input device.

2. The peripheral region is constituted by a hard support member having a rigidity capable of supporting the soft member.

2. The capacitive input device according to claim 1.

3. The hard support member is disposed so as to surround the soft member disposed on the sensor electrode.

3. The capacitive input device according to claim 2.

4. The soft member is disposed only between the operation area and the sensor sheet.

4. The capacitive input device according to claim 2 or 3.

5. the rigid support member is a second rigid support member that defines an aperture between the surface member and the sensor sheet; The soft member is a soft filler that fills the hole.

5. The capacitance type input device according to claim 2, wherein the capacitance type input device is a capacitance type input device having a capacitance of 1 to 4.

6. the rigid support member is a frame-shaped second rigid support member, The soft member is a soft filler that is filled in a frame surrounded by the second hard support member.

5. The capacitance type input device according to claim 2, wherein the capacitance type input device is a capacitance type input device having a capacitance of 1 to 4.

7. the rigid support member is a second rigid support member; The second hard support member contacts the soft member to laterally position and fix the soft member.

7. The capacitive input device according to claim 2, wherein the capacitance is a capacitance of the first electrode.

8. The rigid support member is laminated to the flexible member in the peripheral region.

4. The capacitive input device according to claim 2 or 3.

9. the surface member is laminated on the soft member, and the hard support member is a third hard support member provided between the soft member and a surface facing the soft member in the peripheral region; The third hard support member is configured to have a harder tactile feel in the peripheral region where the soft member and the third hard support member are laminated than in the operation region.

4. The capacitive input device according to claim 2 or 3.

10. The surface member has a flat configuration in which the operation area and the peripheral area are free of irregularities.

10. The capacitance type input device according to claim 1.

11. The surface member has an outer surface that is uneven and / or has a non-flat three-dimensional shape.

9. The capacitance type input device according to claim 1, wherein the capacitance type input device is a capacitance type input device having a capacitance of 1 to 8.

12. The operation area is formed at a plurality of locations on the outer surface, The soft member is laminated on the surface member at a plurality of locations corresponding to the operation area.

12. The capacitive input device according to claim 11.

13. the soft member has a conductive portion therein, The conductive portion increases the value of the capacitance to increase the detection sensitivity in a portion between the operation area and the sensor electrode.

13. The capacitive input device according to claim 1.

14. The conductive portion is a conductive medium contained in the soft member made of a polymer matrix.

14. The capacitive input device according to claim 13.

15. The conductive portion is an orientation portion in which the conductive medium is oriented in the soft member.

15. The capacitive input device according to claim 14.

16. The orientation portion orients the conductive medium so that the conductive medium is chained in the thickness direction of the soft member.

16. The capacitive input device according to claim 15.

17. The orientation portion is such that the conductive medium is discontinuously oriented, When the operation area is pressed by a touch operation, the conductive media come into contact with each other and are electrically connected.

16. The capacitive input device according to claim 15.

18. The soft member is formed of a light-transmitting material that allows the operation area to be illuminated.

18. The capacitive input device according to claim 1.

19. The operation area includes: A first operation area; A second operation area, The sensor electrode is a first electrode corresponding to the first manipulation area; a second electrode corresponding to the second manipulation area; The soft member is a first portion located between the first manipulation area and the first electrode; a second portion located between the second steering area and the second electrode; an insulating groove forming a gap separating the first portion and the second portion; The insulating groove provides electrical insulation between the first portion and the second portion to prevent erroneous detection of the first operation area and the second operation area adjacent to each other.

19. The capacitive input device according to claim 1.

20. The sensor sheet further includes a first hard support member on a surface opposite to the surface on which the soft member is disposed.

20. The capacitance type input device according to claim 1, wherein the capacitance type input device is a capacitance type input device having a capacitance of 100.degree.

21. The soft member is formed by laminating a plurality of members.

21. The capacitive input device according to claim 1.

22. The plurality of members are a combination of insulating soft members and conductive soft members.

22. The capacitive input device of claim 21.

23. The soft member is a gel-like polymer matrix.

23. The capacitive input device according to claim 1.

24. The soft member has a plate shape having a plate thickness in a thickness direction of the soft member and a surface along a plane in a direction intersecting the thickness direction.

24. The capacitive input device according to claim 1, wherein the capacitance is set to a predetermined value.

25. The soft member has a thickness of 1 mm to 5 mm.

25. The capacitive input device according to claim 1.

26. Furthermore, the capacitive input device has a resin film, which is either an elastic urethane film or a thin film, on the soft member side of the surface member.

26. The capacitive input device according to claim 1.

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