JP2014142193A - Load distribution detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a load distribution detector capable of performing highly accurate detection regardless of application even with a simple configuration.SOLUTION: A load distribution detector 1 includes: a plurality of fixed electrodes 30 arrayed along a detection plane; movable electrodes 40 provided in a manner to face the fixed electrodes 30; a plurality of capacitance detection parts 100 constituted by pairs of the fixed electrodes 30 and the movable electrodes 40; and a screening electrode 50 provided on the side of the fixed electrodes 30 relative to the movable electrodes 40. The fixed electrodes 30 which abut each other in a predetermined direction are electrically connected.

Description

  The present invention relates to a load distribution detection apparatus capable of detecting a load distribution by detecting the magnitude of a load for each position, and more particularly to a capacitance type apparatus.

  2. Description of the Related Art Conventionally, for example, a device described in Patent Document 1 is known as a load distribution detection device that detects a load (force) distribution. In the load distribution detection device (surface pressure distribution sensor) described in Patent Document 1, a plurality of electrodes that are orthogonal to each other are disposed on the front side and the back side of a dielectric layer made of urethane rubber, and the intersection of the front side electrode and the back side electrode is detected. (Detection unit).

  Then, the load in each detector is detected based on the change in capacitance caused by the change in the distance between the front electrode and the back electrode due to the compressive deformation of the dielectric layer due to the load, thereby detecting the load distribution. It is configured. Such a load distribution detection device is used as a force sensor attached to, for example, an arm part or a hand part of a robot.

  As a kind of load distribution detection device, a touch panel for detecting an input position on various display screens such as a liquid crystal is used in various fields. Conventionally, in this touch panel, a resistive film type that detects a short-circuit between two electrodes at an input position has been widely used. However, in recent years, with the spread of various smartphones, tablets, and the like, for example, described in Patent Document 2 The use of capacitive touch panels such as those described above is increasing.

  In the touch panel described in Patent Document 2, a plurality of electrodes (sensor lines) orthogonal to each other are arranged on a transparent substrate, and the capacitance between these electrodes and a conductor such as a finger that performs input is used. The input position is detected. Such a capacitance-type touch panel is widely adopted as an input device in a mobile terminal such as a smartphone because multi-touch that allows input to a plurality of positions at the same time is possible.

JP 2010-43881 A JP 2010-267093 A

  However, the conventional capacitance type load distribution detection device has a problem that it is easily affected by noise caused by surrounding static electricity. For this reason, high-precision detection is difficult due to the influence of noise, and applications and installation locations are limited.

  For example, in a load distribution detection device as described in Patent Document 1, since the capacitance between electrodes is easily influenced by a nearby conductor, the load applied by the contact of the conductor is detected. There was a problem that was difficult. In addition, the touch panel as described in Patent Document 2 uses a capacitance between an external conductor and is particularly susceptible to ambient static electricity. There was a problem that it was not possible to detect an input other than the body.

  In addition, the conventional capacitance type load distribution detection device needs complicated control such as mutual capacitance method when detecting a load acting on a plurality of positions such as so-called multi-touch on a touch panel. At the same time, a dedicated one-chip microcomputer or the like may be required, which increases the cost.

  In addition, the conventional capacitance type load distribution detection device can detect the load in the normal direction of the force receiving surface (input surface) that receives the load, but the surface direction of the force receiving surface (the force receiving force). Since it is difficult to detect the load in the direction along the surface with high accuracy, the application is limited.

  In view of such a situation, the present invention intends to provide a load distribution detection device capable of highly accurate detection regardless of the application, while having a simple configuration.

  (1) The present invention is a load distribution detection device that detects a load distribution in a detection surface, and includes a plurality of fixed electrodes arranged along the detection surface, and a movable provided to face the fixed electrodes. An electrode, a plurality of capacitance detection units composed of a pair of the fixed electrode and the movable electrode, and a shield electrode provided on the opposite side of the fixed electrode with respect to the movable electrode, What is adjacent to a predetermined direction is the load distribution detection apparatus characterized by being electrically connected.

  (2) The present invention also includes a substantially sheet-like elastic member made of an elastic material and disposed along the detection surface, wherein the movable electrode and the shield electrode are provided on the elastic member. It is a load distribution detection apparatus as described in said (1).

  (3) In the present invention, the fixed electrode is adjacent to the first fixed electrode in which the ones adjacent in the first direction are electrically connected to each other and in the second direction intersecting the first direction. The load distribution detecting device according to (1) or (2), further comprising: a second fixed electrode that is electrically connected to each other.

  (4) According to the present invention, a plurality of the movable electrodes are provided for each pair of the first fixed electrode and the second fixed electrode, and both the first direction and the second direction are provided. The load distribution detecting device according to (3) above, wherein devices adjacent in different third directions are electrically connected to each other.

  (5) The present invention also provides a position specification for specifying a position of a load in the detection surface based on a change in capacitance in the capacitance detection unit including the pair of the second fixed electrode and the movable electrode. It is a load distribution detection apparatus as described in said (4) characterized by providing a processing means.

  (6) The load distribution detecting device according to (3), wherein the movable electrode is provided as one electrode facing all the fixed electrodes.

  (7) In the present invention, it is also preferable that the fixed electrode is a third fixed electrode in which adjacent ones in a third direction different from both the first direction and the second direction are electrically connected to each other. The load distribution detection device according to (6), further including:

  (8) The present invention also provides a position specification that specifies a position of a load in the detection surface based on a change in capacitance in the capacitance detection unit including the pair of the third fixed electrode and the movable electrode. It is a load distribution detection apparatus as described in said (7) characterized by providing a processing means.

  (9) The present invention also derives a normal direction load acting in a normal direction of the detection surface based on a change in capacitance in the capacitance detection unit, and a plurality of the electrostatic capacitances close to each other. (1) to (8) above, further comprising mechanical quantity conversion processing means for deriving a surface load acting in the surface direction of the detection surface based on a change in capacitance in a capacitance detection unit. It is the load distribution detection apparatus in any one.

  (10) In the present invention, the mechanical quantity conversion processing unit derives the surface direction load by calculating a gravity center position of a capacitance change amount in at least three electrostatic capacitance detection units adjacent to each other. The load distribution detection device according to (9) above, characterized in that:

  (11) The present invention also includes a substantially sheet-like insulating member made of an insulating material and disposed along the detection surface, and the fixed electrode is provided on the insulating member. The load distribution detecting device according to any one of (1) to (10).

  (12) The present invention is also the load distribution detection device according to (11), wherein the insulating member is made of an insulating elastic material.

  (13) The present invention (11) or (11), further comprising a substantially sheet-like auxiliary elastic member made of an elastic material and disposed on the opposite side of the elastic member with respect to the insulating member. The load distribution detection device according to (12).

  (14) The present invention is also characterized in that the auxiliary elastic member is made of an insulating material, and the fixed electrode is provided between the insulating member and the auxiliary elastic member. It is a load distribution detection apparatus as described in above.

  (15) The load according to any one of (1) to (14) above, further comprising an auxiliary shield electrode disposed on the opposite side of the movable electrode with respect to the fixed electrode. This is a distribution detection device.

  According to the load distribution detection device according to the present invention, it is possible to achieve an excellent effect that high-precision detection is possible regardless of the application, though the configuration is simple.

(A) It is a top view of the load distribution detection apparatus which concerns on the 1st Embodiment of this invention. (B) It is a front view of the load distribution detection apparatus. (A) It is a bottom view of the load distribution detection apparatus which concerns on 1st Embodiment. (B) It is the sectional view on the AA line of Fig.1 (a). (A) It is a top view of the elastic member which concerns on 1st Embodiment. (B) It is a bottom view of the elastic member. (C) It is the BB sectional drawing of the figure (a). (D) It is CC sectional view taken on the line of the figure (a). (A) And (b) It is the figure which showed the state which the load of the z direction acted on the force receiving surface of the load distribution detection apparatus which concerns on 1st Embodiment. It is the figure which showed the other form of the load distribution detection apparatus which concerns on 1st Embodiment. It is the figure which showed the other form of the load distribution detection apparatus which concerns on 1st Embodiment. It is the figure which showed the other form of the load distribution detection apparatus which concerns on 1st Embodiment. It is the figure which showed the other form of the load distribution detection apparatus which concerns on 1st Embodiment. (A) It is a top view of the load distribution detection apparatus which concerns on the 2nd Embodiment of this invention. (B) It is a front view of the load distribution detection apparatus. (A) It is a bottom view of the load distribution detection apparatus which concerns on 2nd Embodiment. (B) It is the sectional view on the AA line of Fig.9 (a). (A) It is the figure which showed the state which the load in the xy plane and the load of the z direction acted on the force receiving surface 21 of the load distribution detection apparatus which concerns on 2nd Embodiment. (B) It is the schematic which showed an example at the time of providing the electrode only for the load detection of az direction. (A) It is a top view of the load distribution detection apparatus which concerns on the 3rd Embodiment of this invention. (B) It is a front view of the load distribution detection apparatus. (A) It is a bottom view of the load distribution detection apparatus which concerns on 3rd Embodiment. (B) It is AA sectional view taken on the line of Fig.12 (a). (A) It is the DD sectional view taken on the line of FIG.13 (b). (B) And (c) It is the top view which showed the outline | summary of the load detection which acts on multiple positions. (A) It is a top view of the load distribution detection apparatus which concerns on the 4th Embodiment of this invention. (B) It is a front view of the load distribution detection apparatus. (A) It is a bottom view of the load distribution detection apparatus which concerns on 4th Embodiment. (B) It is AA sectional view taken on the line of Fig.15 (a). (A) It is a top view of the elastic member which concerns on 4th Embodiment. (B) It is a bottom view of the elastic member. (C) It is the BB sectional drawing of the figure (a). (D) It is the EE sectional view taken on the line of the figure (a).

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

<First Embodiment>
First, the load distribution detection apparatus 1 according to the first embodiment of the present invention will be described. FIG. 1A is a plan view of the load distribution detection device 1, and FIG. 1B is a front view of the load distribution detection device 1. Moreover, Fig.2 (a) is a bottom view of the load distribution detection apparatus 1, The same figure (b) is the sectional view on the AA line of Fig.1 (a).

  As shown in these drawings, the load distribution detecting device 1 is provided on the substrate 10, the elastic member 20 fixed to one surface of the substrate 10, and the surface of the substrate 10 opposite to the elastic member 20. A plurality of fixed electrodes 30, a plurality of movable electrodes 40 provided on the surface of the elastic member 20 on the substrate 10 side, a shield electrode 50 provided on the surface of the elastic member 20 on the opposite side of the substrate 10, and the substrate 10 And a connected control device 60.

  In the following description, the surface direction of the substrate 10 is the x direction and the y direction, and the direction orthogonal to the surface of the substrate 10 is the z direction. In addition, although the z direction is assumed to be a vertical direction and the elastic member 20 is fixed to the upper surface 10a of the substrate 10, the posture of the load distribution detection device 1 is not limited to this state. Also, in the drawings, it should be noted that there are portions where the thickness of each portion is exaggerated for easy understanding.

  The substrate 10 is a substantially sheet-like (flat plate) member, and is made of, for example, a resin film such as polyimide or polyethylene terephthalate (PET). As shown in FIGS. 1A and 1B, an elastic member 20 is fixed to the upper surface 10a of the substrate 10 by, for example, an adhesive. Further, as shown in FIG. 2A, on the bottom surface 10b of the substrate 10, four substantially rectangular strip electrodes 12 having a substantially rectangular shape with the x direction as the longitudinal direction are formed. Details will be described later. A part of the x-direction strip electrode 12 is a fixed electrode 30.

  In the present embodiment, the fixed electrode 30 (x-direction band-like electrode 12) is formed on the bottom surface of the substrate 10 so that the substrate 10 is also used as an insulating member disposed between the fixed electrode 30 and the movable electrode 40. Yes. By doing in this way, while being able to comprise the load distribution detection apparatus 1 simply and cheaply, it is possible to make the thickness (z direction dimension) of the load distribution detection apparatus 1 thinner.

  A plurality of wirings 14 that electrically connect the fixed electrode 30 and the movable electrode 40 to the control device 60 are also provided on the bottom surface 10 b of the substrate 10. The movable electrode 40 is connected to the wiring 14 through a connection electrode 16 provided on the upper surface 10 a of the substrate 10 and a through hole 18 penetrating the substrate 10. The x-direction strip electrode 12 (fixed electrode 30), the wiring 14, the connection electrode 16, and the like can be formed by a known method such as screen printing or sputtering.

  The elastic member 20 is a substantially sheet-like member having a substantially rectangular shape in plan view, and is made of an elastic material having an insulating property and elastically deformable, such as various insulating rubbers. The elastic member 20 is disposed along the upper surface 10a of the substrate 10 and is configured to be deformed mainly by receiving a load in the z direction. The upper surface 20a of the elastic member 20 is a force receiving surface 21 that receives a load to be detected. That is, in the present embodiment, the xy plane is a detection surface, and the load distribution detection device 1 is configured to detect a load distribution in the z direction in the xy plane.

  FIG. 3A is a plan view of the elastic member 20, and FIG. 3B is a bottom view of the elastic member 20. FIG. 3C is a cross-sectional view taken along the line BB in FIG. 1A, and FIG. 4D is a cross-sectional view taken along the line CC in FIG. As shown in these drawings, the elastic member 20 has a top surface 20a which is a force receiving surface 21 configured in a substantially smooth surface. The bottom surface 20b of the elastic member 20 is formed with a substantially lattice-shaped convex portion 22 protruding toward the substrate 10 and a concave portion 24 recessed in a substantially rectangular shape between the convex portions 22.

  On the upper surface 10a of the elastic member 20, a shield electrode 50 is formed over substantially the entire surface. Further, on the bottom surface 20 b of the elastic member 20, four substantially rectangular y-direction belt-like electrodes 26 with the y direction as the longitudinal direction are formed. The y-direction band-like electrode 26 is formed so as to extend over the convex portion 22 and the concave portion 24, and is connected to the connection electrode 16 on the upper surface 10a of the substrate 10 at one end portion (the upper end portion in FIG. 2B). It is supposed to be. As will be described in detail later, the portion of the y-direction band electrode 26 located in the recess 24 is a movable electrode 40.

  In this embodiment, the shield electrode 50 and the y-direction band electrode 26 (movable electrode 40) are made of conductive ink applied to the elastic member 20 by a known method such as a screen printing method or a stencil printing method. By doing in this way, although it is a simple and cheap structure, since the freedom degree of a deformation | transformation of the elastic member 20 can be prevented from being impaired, detection accuracy can be improved. The shield electrode 50 and the y-direction band electrode 26 (movable electrode 40) are configured by insert-molding a conductive rubber, a conductive resin, or the like mixed with a conductive filler into the elastic member 20. Also good. Alternatively, the shield electrode 50 and the y-direction band electrode 26 (movable electrode 40) made of an appropriate material may be attached to the elastic member with an appropriate adhesive or the like.

  Returning to FIGS. 1 and 2, the fixed electrode 30 is a part of the x-direction strip electrode 12 as described above, and four fixed electrodes 30 are provided on each of the four x-direction strip electrodes 12. That is, the fixed electrodes 30 are arranged in a matrix along the bottom surface 10b of the substrate 10, that is, along the xy plane that is a detection surface, and those adjacent in the x direction are electrically connected. In addition, the fixed electrode 30 is connected to the control device 60 for each x-direction strip electrode 12 via the wiring 14. That is, the four fixed electrodes 30 adjacent in the x direction are collectively connected to the control device 60 while being electrically connected to each other.

  Similarly, the movable electrode 40 is a part of the y-direction band electrode 26 as described above, and four movable electrodes 40 are provided on each of the four y-direction band electrodes 26. That is, the movable electrodes 40 are arranged in a matrix along the xy plane which is a detection surface, and those adjacent in the y direction are electrically connected. In addition, the movable electrode 40 is connected to the control device 60 for each of the y-direction belt-like electrodes 26 via the wiring 14, and the four movable electrodes 40 adjacent to each other in the y direction are collectively connected to the control device. 60 is connected.

  More specifically, as shown in FIG. 1A, the fixed electrode 30 is a portion that intersects the y-direction band electrode 26 in the x-direction band electrode 12. The movable electrode 40 is a portion that intersects the x-direction band electrode 12 in the y-direction band electrode 26. Accordingly, the fixed electrode 30 and the movable electrode 40 are opposed to each other. In the present embodiment, since the x-direction band electrode 12 and the y-direction band electrode 26 are configured to be substantially orthogonal to each other, the shapes of the fixed electrode 30 and the movable electrode 40 are both rectangular. .

  In the present embodiment, the concave portion 24 of the elastic member 20 is disposed at the intersection of the x-direction strip electrode 12 and the y-direction strip electrode 26 so that the movable electrode 40 is disposed in the concave portion 24 as described above. The fixed electrode 30 and the movable electrode 40 are opposed to each other with a predetermined distance therebetween. As a result, when the elastic member 20 is deformed by receiving a load in the normal direction (that is, the z direction) on the force receiving surface 21, the movable electrode 40 moves (displaces) to move between the fixed electrode 30 and the movable electrode 40. The distance between the two changes, and the capacitance between the two changes. Therefore, the load received on the force receiving surface 21 can be detected by detecting the change in capacitance.

  That is, the pair of fixed electrode 30 and movable electrode 40 facing each other constitute one detection element 100 (that is, a capacitance detection unit) for detecting a load based on a change in capacitance. Then, by detecting capacitance changes in the plurality of detection elements 100, the position and magnitude of the load acting on the force receiving surface 21, that is, the load distribution in the detection plane (in the xy plane) is detected. be able to. Specifically, the position of the load is determined based on which of the x-direction band electrode 12 and the y-direction band electrode 26 the fixed electrode 30 and the movable electrode 40 constituting the detection element 100 whose capacitance has changed. And the magnitude of the load can be detected based on the amount of change in capacitance.

  In the present embodiment, 16 detection elements 100 are provided by providing four x-direction strip electrodes 12 and four y-direction strip electrodes 26, but it goes without saying that the number of detection elements 100 is not limited to this. Yes. That is, by adjusting the number of detection elements 100, an appropriate resolution can be set.

  The shield electrode 50 is formed over the entire upper surface 20a of the elastic member 20 that is the force receiving surface 21 as described above, and serves as a ground electrode that is grounded via a wiring (not shown). In this embodiment, by providing the shield electrode 50 on the upper surface 20a in this manner, the detection element 100 (the fixed electrode 30 and the movable electrode 40) is electrically shielded from the force receiving surface 21 side to which a load is applied. Yes.

  Thereby, in the present embodiment, noise due to static electricity charged on an external object or the like to which a load is applied is cut, and the load is detected regardless of the material of the external object to which the load is applied, that is, the human skin or metal It is possible to detect the load with high accuracy even when the power contacts the force receiving surface directly. In particular, in this embodiment, since the shield electrode 50 is made of conductive ink as described above, the detection element 100 can be electrically shielded without adopting a complicated structure. .

  The shield electrode 50 may be formed, for example, in a mesh shape or a hook shape. Further, an appropriate coating layer, an elastically deformable sheet-like insulating member, or the like may be disposed on the shield electrode 50 (outside), and the upper surface thereof may be used as the force receiving surface 21. That is, the shield electrode 50 may be disposed so as not to directly contact an external object to which a load is applied.

  The control device 60 is connected to the x-direction strip electrode 12 and the y-direction strip electrode 26, detects a change in capacitance in each detection element 100, and derives a load distribution based on the change. The control device 60 of the present embodiment executes capacitance calculation processing means 62 that detects a change in capacitance in each detection element 100 and arithmetic processing based on the detected change in capacitance, and performs a detection process in each detection element 100. And a mechanical quantity conversion processing means 64 for deriving a load in the normal direction (z direction) of the force receiving surface 21.

  The detection of the change in capacitance by the capacitance detection processing means 62 may employ either a self-capacitance method or a mutual capacitance method, or other known methods. It may be. That is, an appropriate method may be adopted according to the use of the load distribution detection device 1 or the like. In addition, any known method may be adopted as a method for deriving the load from the capacitance change in each detection element 100.

  The control device 60 also stores the capacitance change or the derived load distribution in each detection element 100 as necessary, or outputs it to an external device such as a PC. The control device 60 may be provided separately from the load distribution detection device 1. That is, the load distribution detection device 1 may be controlled by an arithmetic processing device such as an external PC.

  Next, the operation of the load distribution detection device 1 of this embodiment will be described. 4A and 4B are views showing a state in which a load Fz in the z direction is applied to the force receiving surface 21 of the load distribution detection device 1, and is a cross-sectional view taken along the line AA in FIG. It is. As described above, the load distribution detection device 1 according to this embodiment detects the magnitude of the load Fz in the z direction (normal direction) applied to the force receiving surface 21 of the elastic member 20 for each position, thereby detecting the load Fz. Detect distribution.

  As shown in FIG. 4A, when a different load Fz is applied to each part of the force receiving surface 21, the elastic member 20 is elastically deformed according to the magnitude of the load Fz. Then, the movable electrode 40 comes close to the fixed electrode 30 according to the magnitude of the load Fz. Further, when the load Fz is released, the elastic member 20 tries to return to the original state by the restoring force of elastic deformation, so that the movable electrode 40 is separated from the fixed electrode 30.

  That is, in each detection element 100, since an electrostatic capacitance changes according to the magnitude | size of the load Fz which acts, based on this, distribution of the load Fz can be calculated | required. At this time, for example, if the amount of change in capacitance in the plurality of detection elements 100 is interpolated, the resolution of load distribution detection can be increased to the number of detection elements 100 or more.

  Further, as shown in FIG. 4B, when the load Fz is locally applied, the position where the load Fz is applied can be specified depending on which capacitance of the detection element 100 has changed. . That is, the load distribution detection device 1 can be used as an input device that detects an input position. Even in this case, if the center position of the load Fz is obtained by interpolating the amount of change in capacitance in the plurality of detection elements 100, the resolution of input position detection can be increased.

  Next, the other form of the load distribution detection apparatus 1 of this embodiment is demonstrated. 5-8 is the figure which showed the other form of the load distribution detection apparatus 1. FIG.

  FIGS. 5A and 5B show an example in which the convex portion 22 of the elastic member 20 is formed in a columnar shape. FIG. 5A is a bottom view of the elastic member 20 and FIG. These are sectional views taken along the line BB of FIG. The shape of the convex portion 22 is not particularly limited. Thus, for example, a plurality of convex portions 22 configured in a columnar shape may be provided.

  By appropriately setting the shape and arrangement of the convex portions 22, the strength of the elastic member 20 and the degree of elastic deformation of the elastic member 20 when the force receiving surface 21 receives a load can be adjusted. Further, by adjusting the gas flow between the substrate 10 and the elastic member 20 according to the shape and arrangement of the protrusions 22, the elastic member 20 is elastically deformed by the compression and expansion of the gas when the elastic member 20 is elastically deformed. It can be prevented from being inhibited.

  In addition, the convex part 22 may be comprised by wall shape, and may be comprised by column shape. Further, the convex portion 22 may be configured in a conical shape, a pyramid shape, a truncated cone shape, a truncated pyramid shape, a hemispherical shape, or the like, or an appropriate air hole in the convex portion 22 configured in a wall shape. May be provided. Further, the elastic member 20 may be configured such that, when receiving a load, both the convex portion 22 and a portion other than the convex portion 22 are elastically deformed, or only the convex portion 22 or a portion other than the convex portion 22. Only the elastic deformation may be adopted.

  Further, in the examples shown in FIGS. 3A to 3D and FIGS. 5A and 5B, the convex portions 22 are provided between the detection elements 100 (around the detection elements 100). However, the convex portion 22 may be provided in the detection element 100. By providing the convex portion 20 in the detection element 100, it is possible to further increase the strength and durability of the elastic member 20 and the entire apparatus. In this case, although not shown, for example, a hole may be provided in the center of the movable electrode 40 and the protrusion 22 may be provided in the hole. Further, the movable electrode 40 may be provided on the convex portion 22 in the detection element 100.

  FIG. 5C is a schematic cross-sectional view showing an example in which the movable electrode 40 is provided on the convex portion 22 in the detection element 100. In this example, a mountain-shaped convex portion 22a configured in a substantially conical shape is provided in the detection element 100, and the movable electrode 40 is provided on the surface of the mountain-shaped convex portion 22a on the substrate 10 side. In this case, as shown in FIG. 6C, the mountain-shaped convex portion 22a is deformed so as to be crushed by the load Fz. The area of the part will change. And the electrostatic capacitance in the detection element 100 will change mainly according to the change of the area of this contact part.

  Thus, by providing the movable electrode 40 on the mountain-shaped convex portion 22a in the detection element 100, not only the strength and durability of the elastic member 20 and the entire apparatus are increased, but also the capacitance of the detection element 100 is changed. It becomes possible to make it more stable. Further, by adjusting the shape of the inclined surface 22a1 (for example, the inclination angle or curved surface shape) of the mountain-shaped convex portion 22a, the amount of change in capacitance and the mode of change (for example, linear change or quadratic curve) Therefore, the detection accuracy can be improved.

  The shape of the mountain-shaped convex portion 22a is not limited to a substantially conical shape, and may be, for example, a pyramid shape or a hemispherical shape, and the height changes, for example, in a step shape instead of the inclined surface 22a1. The shape which has the part to do may be sufficient. That is, the shape of the mountain-shaped convex portion 22a is such that the contact area with the upper surface 10a of the substrate 10 increases by being pressed and crushed by the load, gradually from the substantially center of the detection element 100 toward the outside. Any shape having a portion away from the upper surface 10a may be used. Further, instead of providing the movable electrode 40 on the mountain-shaped convex portion 22a provided on the elastic member 20, the movable electrode 40 itself is formed by forming the movable electrode 40 from an elastically deformable conductive rubber or the like and providing an uneven shape. May be provided with a mountain-shaped convex portion 22a.

  6 (a) and 6 (b) show an example in which an uneven shape is provided on the force receiving surface 21 of the elastic member 20. FIG. 6 (a) is a plan view of the elastic member 20, and FIG. ) Is a cross-sectional view taken along line BB in FIG. The force receiving surface 21 of the elastic member 20 is not limited to the one configured to be a smooth surface. Thus, for example, a plurality of columnar protrusions 21 a may be provided on the force receiving surface 21. . Thus, by providing an appropriate uneven shape on the force receiving surface 21, the elastic deformation state of the elastic member 20 when receiving a load can be set to a more appropriate state.

  The shape of the protruding portion 21a is not particularly limited, and may be other shapes such as a hemispherical shape. 6A and 6B show an example in which the protrusion 21a is provided at a position corresponding to each detection element 100, the arrangement of the protrusion 21a is not limited to this. For example, other arrangements such as arranging the protruding portions 21a between the detection elements 100 may be possible. Further, the shape and size of the protrusion 21a may be varied, or a recess may be provided in place of the protrusion 21a or together with the protrusion 21a.

  FIGS. 7A and 7B show an example in which the auxiliary elastic member 70 is provided on the bottom surface 10b side of the substrate 10, and is a cross-sectional view taken along the line AA in FIG. In this example, a substantially sheet-like auxiliary elastic member 70 is disposed on the bottom surface 10 b side of the substrate 10, that is, on the opposite side of the elastic member 20. The auxiliary elastic member 70 is made of an elastic material having an insulating property and elastically deformable, such as various insulating rubbers, and is fixed to the bottom surface 10b of the substrate 10 with an adhesive or the like.

  Thus, by providing the auxiliary elastic member 70, the strength and rigidity of the load distribution detection device 1 can be appropriately increased even when the substrate 10 is made of a relatively soft material such as a silicon rubber film. It becomes possible. That is, since the auxiliary elastic member 70 is appropriately provided in conjunction with the material selection of the substrate 10, the strength and rigidity of the load distribution detection device 1 can be appropriately set according to the use and the use environment. The versatility of the detection apparatus 1 can be improved. Further, by covering the fixed electrode 30 with the auxiliary elastic member 70, the fixed electrode 30 can be appropriately protected.

  In the case where the auxiliary elastic member 70 is provided, the fixed electrode 30 may be formed not on the substrate 10 but on the auxiliary elastic member 70. Furthermore, the conductive material obtained by applying the fixed electrode 30 to the upper surface 70a of the auxiliary elastic member 70 may be used. You may make it comprise from ink. In addition, both the auxiliary elastic member 70 and the substrate 10 may be made of insulating rubber. In this case, the load distribution detection device 1 can be configured to be extendable and contractable in the xy plane. The versatility of the distribution detection apparatus 1 can be further enhanced.

  FIG. 7B shows an example in which the auxiliary shield electrode 52 is provided on the auxiliary elastic member 70. In this example, the auxiliary shield electrode 52 is formed over substantially the entire bottom surface 70 b of the auxiliary elastic member 70. The auxiliary shield electrode 52 is made of conductive ink applied to the bottom surface 70b of the auxiliary elastic member 70, and is grounded via a wiring (not shown). By providing the auxiliary shield electrode 52 in this way, noise due to surrounding static electricity or the like can be more effectively cut, so that the detection accuracy can be improved and the versatility of the load distribution detection device 1 can be improved. .

  The auxiliary elastic member 70 may be provided in a plurality of layers. In this case, the fixed electrode 30, the auxiliary shield electrode 52, various wirings, and the like may be disposed between the auxiliary elastic members 70. . Further, the auxiliary elastic member 70 may have a dimension in the xy plane that is different from the dimension in the xy plane of the elastic member 70, and covers the wiring 14 formed on the substrate 10, for example. May be. Further, the auxiliary shield electrode 52 may be formed in, for example, a mesh shape or a hook shape. Further, the shield electrode 50 and the auxiliary shield electrode 52 may be electrically short-circuited through a through hole or the like.

  FIG. 8A shows an example of another form of the x-direction band electrode 12, and FIG. 8B shows an example of another form of the y-direction band electrode 26. 1A is a bottom view of the substrate 10 and FIG. 1B is a bottom view of the elastic member 20. The shapes of the x-direction strip electrode 12 including the fixed electrode 30 and the y-direction strip electrode 26 including the movable electrode 40 are not particularly limited. For example, the fixed electrode 30 and the movable electrode 40 are substantially circular as described above. In addition, the widths of the fixed electrode 30 and the movable electrode 40 and other portions may be different.

  Thus, by adjusting the shapes of the x-direction strip electrode 12 and the y-direction strip electrode 26 and the shapes of the fixed electrode 30 and the movable electrode 40, the amount of change in capacitance when the elastic member 20 is elastically deformed and Since it is possible to appropriately set the change mode (for example, a linear change or a quadratic change), the detection accuracy can be increased.

  Needless to say, the shapes of the fixed electrode 30 and the movable electrode 40 may be other shapes such as a polygonal shape and an elliptical shape. Further, the x-direction strip electrode 12 and the y-direction strip electrode 26 are configured not to linearly connect the fixed electrodes 30 and the movable electrodes 40 but to connect, for example, by bypassing the convex portion 22 and the like. It may be a thing.

  Further, the fixed electrode 30 and the movable electrode 40 are not limited to those configured as a part of the x-direction band-shaped electrode 12 and the y-direction band-shaped electrode 26, respectively. The electrodes 40 may be electrically connected. That is, the fixed electrode 30 may be any electrode that is adjacent to the x direction by any known method, and the movable electrode 40 is any electrode that is adjacent to the y direction. What is necessary is just to be electrically connected by such a method.

<Second Embodiment>
Next, a load distribution detection apparatus 2 according to the second embodiment of the present invention will be described. The load distribution detection device 2 according to the present embodiment has a surface direction of the force receiving surface 21, that is, an xy plane (detection) in addition to the distribution of the load acting in the normal direction of the force receiving surface 21, that is, the z direction. It is configured to detect the distribution of loads acting in any direction (in the plane) (direction parallel to the xy plane). In the following description, the same parts as those of the load distribution detection device 1 of the first embodiment are denoted by the same reference numerals and the description thereof is omitted, and the parts different from the first embodiment will be described.

  FIG. 9A is a plan view of the load distribution detection device 2, and FIG. 9B is a front view of the load distribution detection device 2. Moreover, Fig.10 (a) is a bottom view of the load distribution detection apparatus 2, and the same figure (b) is the sectional view on the AA line of Fig.9 (a).

  As shown in these drawings, the load distribution detection device 2 of the present embodiment includes eight x-direction strip electrodes 12 and eight y-direction strip electrodes 26 arranged so as to cross each other. Accordingly, the x-direction strip electrode 12 and the y-direction strip electrode 26 each have eight portions that intersect each other. The x-direction strip electrode 12 is provided with eight fixed electrodes 30 and the y-direction strip electrode 12. Eight movable electrodes 40 are provided at 26. The movable electrode 40 is arranged in one recess 24 as a set of four adjacent in the x direction and the y direction, and the fixed electrode 30 is movable with a predetermined interval. The electrodes 40 are opposed to each other.

  That is, in the present embodiment, one two-axis detection element 110 is configured from the four detection elements 100 adjacent to each other in the x direction and the y direction, and the load in the z direction and the xy plane by the two axis detection element 110. The load can be detected. Therefore, in the present embodiment, the mechanical quantity conversion processing unit 64 of the control device 60 receives the calculation amount based on the amount of change in capacitance in the four detection elements 100 included in the two-axis detection element 110. In addition to the magnitude of the load in the normal direction (z direction) of the force surface 21, the magnitude and direction of the load acting in the surface direction of the force receiving surface 21 (any direction in the xy plane) are derived. To do.

  Moreover, in this embodiment, when the load in an xy plane is received by providing the projection part 21a in the position corresponding to the biaxial detection element 110 of the upper surface 20a (power receiving surface 21) of the elastic member 20. In addition, the elastic member 20 is deformed so that the protrusion 21a and the vicinity thereof are inclined by the moment.

  FIG. 11A is a diagram showing a state in which the load Fxy in the xy plane and the load Fz in the z direction are applied to the force receiving surface 21 of the load distribution detection device 2, and FIG. It is AA sectional view. As shown in FIG. 9, when a load Fxy is applied to the force receiving surface 21, the protruding portion 21 a of the elastic member 20 and the vicinity thereof are elastically deformed so as to be inclined, and the four detection elements included in the biaxial detection element 110. At 100, the distance between the fixed electrode 30 and the movable electrode 40 changes. That is, the capacitances of the four detection elements 100 included in the two-axis detection element 110 change.

  The mechanical quantity conversion processing means 64 of the control device 60 derives the load in the x direction based on the difference in the amount of change in capacitance between the two detection elements 100 adjacent in the x direction in the biaxial detection element 110, for example, y A load in the y direction is derived based on the difference in the amount of change in capacitance between two detection elements 100 adjacent in the direction. Then, the magnitude and direction of the load Fxy are derived by vector synthesis of the x-direction load and the y-direction load. Thereby, since the load Fxy is detected for every biaxial detection element 110, distribution of the load Fxy can be calculated | required based on this.

  On the other hand, when the load Fz is applied to the force receiving surface 21, the protrusion 21 a of the elastic member 20 and its vicinity are deformed so as to be close to the substrate 10, and the load Fxy and the load Fz act on the force receiving surface 21 in a composite manner. In this case, the protrusion 21a of the elastic member 20 and the vicinity thereof are deformed so as to be close to the substrate 10 while being inclined.

  Therefore, in the present embodiment, the mechanical quantity conversion processing means 64 of the control device 60 calculates the magnitude of the load Fz based on the total amount of change in capacitance of the four detection elements 100 included in the biaxial detection element 110. To derive. As a result, the influence of the load Fxy can be eliminated and only the load Fz can be detected for each of the two-axis detection elements 110, so that the distribution of the load Fz can be obtained. That is, according to the load distribution detection device 2 of the present embodiment, the distribution of the load Fxy and the distribution of the load Fz are independent from each other even when the load Fxy and the load Fz act on the force receiving surface 21 in a composite manner. Can be detected.

  Further, in the present embodiment, the adjacent electrodes in the x direction of the fixed electrode 30 are electrically connected to each other, and the adjacent electrodes in the y direction of the movable electrode 40 are electrically connected to each other, so that loads in a plurality of directions are obtained. Although the configuration can detect the distribution of (load Fxy and load Fz), it is possible to efficiently detect a change in capacitance in each detection element 100. That is, the entire apparatus can be configured more simply as compared with a case where a plurality of load detection apparatuses capable of detecting loads in a plurality of directions are individually arranged (for example, the technique described in the background art of Patent Document 1). In addition to being possible, it is possible to detect load distributions in a plurality of directions at higher speeds.

  In addition, the detection of the change in capacitance by the capacitance detection processing means 62 can adopt either the self-capacitance method or the mutual capacitance method, as in the first embodiment, and other known methods. It is also possible to adopt. In addition to the above method, other known methods can be adopted as a method for deriving the load from the capacitance change in each detection element 100. Alternatively, the derivation of the load in the z direction may be omitted, and only the load distribution in the xy plane may be detected.

  Further, the shape of the protruding portion 21a is not limited to a cylindrical shape, and other appropriate shapes such as a hemispherical shape and a conical shape can be employed. In addition, a plurality of protrusions 21a may be provided at positions corresponding to the biaxial detection elements 110, or the protrusions 21a may be provided at portions other than the positions corresponding to the biaxial detection elements 110. Needless to say, the various configurations shown in the first embodiment may be applied to the load distribution detection device 2 of the present embodiment.

  The number of detection elements 100 included in the biaxial detection element 110 is not limited to four, and may be five or more. That is, the biaxial detection element 110 can be configured from an appropriate number of detection elements 100 according to the shape, arrangement, connection direction and the like of the fixed electrode 30 and the movable electrode 40. Further, the biaxial detection element 110 may be configured by three detection elements 100. In this case, as disclosed in Japanese Patent No. 4756097 related to the present applicant, the load in the xy plane is derived by calculating the gravity center position of the capacitance change amount in the three detection elements 100. Can do. Needless to say, even when the number of detection elements 100 is four or more, the load in the xy plane can be derived by calculating the position of the center of gravity of the capacitance change amount in each detection element 100.

  In addition, instead of deriving the magnitude of the load in the z direction based on the total amount of change in capacitance of the plurality of detection elements 100 included in the biaxial detection element 110, an electrode dedicated to load detection in the z direction is provided. You may make it provide. FIG. 11B is a schematic diagram illustrating an example in which an electrode dedicated to load detection in the z direction is provided. In this example, every two additional x-direction band electrodes 12 a are provided between the x-direction band electrodes 12, and every other y-direction band electrode 26 a is provided between the y-direction band electrodes 26. The additional x-direction band-shaped electrode 12a and the additional y-direction band-shaped electrode 26a intersect each other at a substantially central portion of the axis detection element 110.

  Thus, in this example, the intersection of the additional x-direction strip electrode 12a with the additional y-direction strip electrode 26a is used as the z-direction fixed electrode 30a dedicated to load detection in the z direction, and the additional x in the additional y-direction strip electrode 26a. A crossing portion with the direction band electrode 12a is a z-direction movable electrode 40a dedicated to z-direction load detection. The z-direction detection element 102, which is a pair of the z-direction fixed electrode 30a and the z-direction movable electrode 40a, is included in the biaxial detection element 110.

  Therefore, in this example, the mechanical quantity conversion processing means 64 of the control device 60 is based on only the amount of change in the capacitance of the z-direction dedicated detection element 102 disposed substantially at the center of the biaxial detection element 110. , And the load in the xy plane is derived based on the amount of change in capacitance in the four detection elements 100 around the z-direction dedicated detection element 102. In this way, since the load in the z direction can be detected more directly, it may be possible to improve the detection accuracy of the load in the z direction. In addition, it may be possible to simplify the load derivation process in the z direction and speed up the process of the control device 60.

  The additional x-direction strip electrode 12a and the additional y-direction strip electrode 26a may have the same shape and size as the x-direction strip electrode 12 and the y-direction strip electrode 26, or may have different shapes or sizes. Also good. In this example, the intersection 104a between the additional x-direction strip electrode 12a and the y-direction strip electrode 26, and the intersection 104b between the additional y-direction strip electrode 26a and the x-direction strip electrode 12 detect a change in capacitance. Although it is not used as a detection element, a change in electrostatic capacitance at these intersections 104a and 104b may be used for detection of a load in the xy plane or a load in the z direction.

<Third Embodiment>
Next, a load distribution detection apparatus 3 according to the third embodiment of the present invention will be described. The load distribution detection device 3 according to the present embodiment detects the distribution of loads acting in the normal direction of the force receiving surface 21, that is, the z direction, and the fixed electrode 30 that faces the movable electrode 40 with a space therebetween. As described above, by providing two types of electrodes, the first fixed electrode 32 and the second fixed electrode 34, the load acting on a plurality of positions can be easily detected even with a simple control method. In the following description, the same parts as those of the load distribution detection device 1 of the first embodiment are denoted by the same reference numerals and the description thereof is omitted, and the parts different from the first embodiment will be described.

  FIG. 12A is a plan view of the load distribution detection device 3, and FIG. 12B is a front view of the load distribution detection device 3. Moreover, Fig.13 (a) is a bottom view of the load distribution detection apparatus 3, and the same figure (b) is the sectional view on the AA line of Fig.12 (a). 14A is a cross-sectional view taken along the line D-D in FIG. 13B, and FIGS. 14B and C are plan views showing an outline of load detection acting on a plurality of positions. is there.

  As shown in these drawings, the load distribution detection device 3 according to the present embodiment rises to the right in plan view in addition to the x-direction strip electrode 12 continuous in the x direction and the y-direction strip electrode 26 continuous in the y direction. The diagonal direction strip | belt-shaped electrode 13 continuous in the diagonal line L1 direction is provided. The first fixed electrode 32 is provided as a part of the x-direction band electrode 12, and the second fixed electrode 34 is electrically connected to each other in the diagonal L1 direction by the diagonal band electrode 13. At the same time, it is provided so as to be connected to the control device 60 via the wiring 14 collectively.

  In the present embodiment, the y-direction strip electrode 26 is configured in the same shape as the shape shown in FIG. 8B, and the movable electrode 40 is configured in a substantially circular shape as a part of the y-direction strip electrode 26. . On the other hand, as shown in FIGS. 13 (a) and 14 (a), the x-direction strip electrode 12 has a shape in which the first fixed electrode 32 is formed in a substantially annular shape in the shape shown in FIG. 8 (a). In other words, the second fixed electrode 32 is configured to have a shape in which a hole 32 a is provided at the center. Then, as shown in FIG. 14A, a substantially circular second fixed electrode 34 is provided in the hole 42a.

  In the present embodiment, the substrate 10 has a two-layer structure including a first layer 10c on the elastic member 20 side and a second layer 10d on the opposite side of the elastic member 20, and the x-direction strip electrode 12 (fixed electrode 30). As shown in FIG. 14A, the second fixed electrode 34 is formed between the first layer 10c and the second layer 10d. And the diagonal direction strip | belt-shaped electrode 13 is formed in the bottom face 10b (namely, bottom face of the 2nd layer 10d) of the board | substrate 10, as shown to Fig.13 (a) and (b), The second fixed electrode 34 is electrically connected. As a result, the second fixed electrode 34 is configured such that objects adjacent to each other in the diagonal L1 direction different from both the x direction and the y direction are electrically connected. In addition, the second fixed electrode 34 is connected to the control device 60 for each diagonal band-like electrode 13 via the wiring 14.

  As described above, in the present embodiment, the first fixed electrode 32 and the second fixed electrode 34 are provided as the fixed electrode 30, thereby detecting the load for detection composed of the pair of the first fixed electrode 32 and the movable electrode 40. A position specifying detection element 106, which is a pair of the second fixed electrode 34 and the movable electrode 40 and for specifying the position of the load, is provided at substantially the same position as the element 100. As a result, it is possible to detect loads acting on a plurality of positions without requiring complicated control.

  Therefore, the control device 60 according to the present embodiment includes a capacitance detection processing unit 62 that detects a change in capacitance in each detection element 100 and each position specifying detection element 106, and the capacitance of each detection element 100. In addition to the mechanical quantity conversion processing means 64 for deriving the magnitude of the load in the z direction based on the amount of change, a position specifying processing means 66 for specifying the positions of a plurality of loads in the z direction is provided. The position specifying processing unit 66 executes a calculation process based on the amount of change in capacitance in each position specifying detection element 106, so that the position of the load can be determined even when a load in the z direction is applied to a plurality of positions. Identify.

  As shown in FIG. 14B, in the load distribution detection device 1 including only the fixed electrode 30 connected in the x direction and the movable electrode 40 connected in the y direction, for example, the force receiving surface 21 of the elastic member 20. For example, depending on the self-capacitance method, the load Fz is applied to two positions P1 and P2, or the load Fz is applied to two positions P3 and P4. A so-called ghost phenomenon occurs in which it is impossible to determine whether the failure has occurred.

  On the other hand, as shown in FIG. 5B, in the load distribution detection device 3, even when a plurality of loads Fz are applied at a position where the ghost phenomenon occurs, any of the position specifying detection elements 106 is statically detected. Based on whether the capacitance has changed, the positions of the plurality of loads Fz can be specified. Specifically, as shown in FIG. 5B, the position specifying processing unit 66 detects whether the load Fz is applied to, for example, two positions P1 and P2 and two positions P3 and P4. Capacitance of detecting element 106 for position identification connected to any diagonal strip electrode 13 (that is, including second fixed electrode 34 connected to any diagonal strip electrode 13) when element 100 cannot discriminate The positions of the plurality of loads Fz are specified based on whether or not has changed.

  That is, in the example shown in FIG. 5B, the position specifying processing unit 66 is connected to the y-direction band electrode 26-1 passing through the positions P1 and P4 (that is, the movable electrode 40 belonging to the y-direction band electrode 26-1). Among the four position specifying detection elements 106), the capacitance in the position specifying detection element 106 connected to the diagonal band electrode 13-1 passing through the position P1 is changed, and the diagonal band electrode passing through the position P4 is changed. Based on the fact that the capacitance in the position specifying detection element 106 connected to 13-4 does not change, it is detected that the load Fz has acted on the position P1. The position specifying processing unit 66 also specifies the position connected to the diagonal band electrode 13-2 passing through the position P2 among the four position specifying detection elements 106 connected to the y-direction band electrode 26-2 passing through the positions P2 and P3. Based on the fact that the capacitance in the detection element 106 for use changes and the capacitance in the position detection element 106 connected to the diagonal strip electrode 13-3 passing through the position P3 does not change, the load Fz is changed to the position P2. Detecting that it has acted.

  As described above, in the present embodiment, the ghost phenomenon can be avoided without employing complicated control, so that the processing speed can be improved. In addition, since the control device 60 can be configured from a general-purpose one-chip microcomputer or the like without using a dedicated one-chip microcomputer such as a mutual capacitance method, it is possible to reduce costs. In addition, since there is no restriction by a dedicated one-chip microcomputer, the degree of freedom in design is improved.

  Note that the connection direction of the second fixed electrode 34 is not limited to the diagonal L1 direction, and any of the connection direction of the first fixed electrode 32 (x direction) and the connection direction of the movable electrode 40 (y direction). Both directions may be different. Further, other appropriate shapes and arrangements can be adopted as the shapes and arrangements of the first fixed electrode 32 and the second fixed electrode 34. Similarly, other appropriate shapes and arrangements can be adopted for the shapes and arrangements of the movable electrode 40 and the convex portions 22 and the concave portions 24 of the elastic member 20. Further, the capacitance change in the position detection element 106 may be used to derive the load in the z direction. Alternatively, the derivation of the load in the z direction may be omitted, and only the position where the load is applied may be detected. Needless to say, the various configurations shown in the first embodiment and the second embodiment may be applied to the load distribution detection device 3 of the present embodiment.

<Fourth Embodiment>
Next, a load distribution detection apparatus 4 according to the fourth embodiment of the present invention will be described. The load distribution detection device 4 according to the present embodiment detects the distribution of loads acting in the normal direction of the force receiving surface 21, that is, the z direction, and the first fixed electrode 32 and the second fixed electrode 34. In addition, by providing the third fixed electrode 36, it is possible to simplify the configuration of the movable electrode 40 provided on the elastic member 20 that is deformed by receiving a load. In the following description, the same parts as those of the load distribution detection devices 1 and 3 of the first and third embodiments are denoted by the same reference numerals and the description thereof is omitted, and the first and third embodiments are omitted. Different parts will be described.

  FIG. 15A is a plan view of the load distribution detection device 4, and FIG. 15B is a front view of the load distribution detection device 4. FIG. 16A is a bottom view of the load distribution detecting device 4, and FIG. 16B is a cross-sectional view taken along the line AA in FIG. FIG. 17A is a plan view of the elastic member 20 in the present embodiment, and FIG. 17B is a bottom view of the elastic member 20. FIG. 3C is a cross-sectional view taken along the line BB of FIG. 1A, and FIG. 4D is a cross-sectional view taken along the line EE of FIG.

  As shown in FIGS. 15 (a) and 16 (a), the first fixed electrode 32 and the second fixed electrode 34 are each formed in a substantially U-shape and arranged so as to face each other in an oblique direction. Has been. The third fixed electrode 36 is configured in a substantially rectangular shape (substantially diamond shape), and is disposed between the first fixed electrode 32 and the second fixed electrode 34. In other words, the first fixed electrode 32 and the second fixed electrode 34 are configured so as to surround the periphery of the third fixed electrode 36.

  The first fixed electrodes 32 that are adjacent to each other in the x direction via the connection wiring 15 are electrically connected to each other and are collectively connected to the control device 60 via the wiring 14 while being electrically connected to each other. It is connected. The second fixed electrodes 34 are electrically connected to each other adjacent to each other in the y direction via the connection wiring 15 and are collectively connected to each other via the wiring 14 while being electrically connected to each other. 60. The third fixed electrode 36 is configured as a part of the diagonal strip electrode 13 that continues in the diagonally upward diagonal L2 direction in plan view, and is connected to the control device 60 together with the diagonal strip electrode 13 via the wiring 14. Has been.

  In this embodiment, as shown in FIG. 16A, the first fixed electrode 32, the second fixed electrode 34, the third fixed electrode 36 (diagonal band electrode 13), and the connection electrode 15 are attached to the substrate 10. Is provided on the bottom surface 10b. Therefore, in this embodiment, by providing the jumper wiring 15a and the insulating layer 15b in the middle of the connection wiring 15, the connection wiring 15 and the second fixed electrode 34 that connect the first fixed electrodes 32 that intersect each other. Are not electrically short-circuited with the connection wiring 15 and the diagonal strip electrode 13.

  As shown in FIGS. 17A to 17D, the elastic member 20 has a convex portion 22 and a concave portion 24 on the bottom surface 20b in accordance with the shape and arrangement of the first to third fixed electrodes 32, 34, and 36. Is formed. The movable electrode 40 is provided as one electrode facing all of the first to third fixed electrodes 32, 34, 36 on the bottom surface 20 b of the elastic member 20. In other words, the movable electrode 40 is in a state where a plurality of electrodes respectively opposed to the plurality of first to third fixed electrodes 32, 34, 36 are connected to each other.

  With such an electrode configuration, in this embodiment, as the detection element 100 for load detection, the first detection element 100a formed of a pair of the first fixed electrode 32 and the movable electrode 40, the second fixed electrode 34, and A second detection element 100b composed of a pair of movable electrodes 40 is provided at substantially the same position, and a position specifying detection element 106 composed of a pair of the third fixed electrode 36 and the movable electrode 40 is further provided at substantially the same position as these. I am trying to provide it.

  Therefore, the control device 60 according to the present embodiment detects the capacitance change in each first detection element 100a, each second detection element 100b, and each position specifying detection element 106. And a mechanical quantity conversion processing means 64 for deriving the magnitude of the load in the z direction based on the amount of change in capacitance in each first detection element 100a and each second detection element 100b, and each position specifying detection Position specifying processing means 66 for specifying the positions of a plurality of loads in the z direction based on the amount of change in capacitance in the element 106 is provided.

  Thus, in the present embodiment, similarly to the third embodiment, the ghost phenomenon can be avoided without adopting complicated control, so that the processing speed can be improved. That is, even if a ghost phenomenon occurs when detecting the positions of a plurality of loads in the z direction due to capacitance changes in the first detection element 100a and the second detection element 100b, The position of a plurality of loads in the z direction can be specified by a change in capacitance in the detection element 106. In addition, since the control device 60 can be configured from a general-purpose one-chip microcomputer or the like, it is possible to reduce costs and improve design flexibility.

  Furthermore, in this embodiment, since the electrodes that are electrically connected to each other adjacent to each other in a predetermined direction are the fixed electrodes 30 provided on the substrate 10, they are provided on the elastic member 20 that repeatedly deforms under a load. It is possible to simplify the configuration of the movable electrode 40 to be provided. Thereby, while reducing manufacturing cost, the intensity | strength and durability of the elastic member 20 and the movable electrode 40 can be improved. Further, since the degree of freedom of the shape of the elastic member 20 is increased, it is possible to further reduce the thickness and size of the entire device while increasing the strength and durability of the device.

  Note that the connection directions of the first to third fixed electrodes 32, 34, and 36 are not limited to the x direction, the y direction, and the diagonal L2 direction, respectively. Also good. Further, other appropriate shapes and arrangements can be adopted as the shapes and arrangements of the first to third fixed electrodes 32, 34, and 36. Similarly, other appropriate shapes and arrangements can be adopted for the shapes and arrangements of the movable electrode 40 and the convex portions 22 and the concave portions 24 of the elastic member 20. Further, the capacitance change in the position detection element 106 may be used to derive the load in the z direction. Alternatively, the derivation of the load in the z direction may be omitted, and only the position where the load is applied may be detected. Alternatively, the diagonal band electrode 13 and the third fixed electrode 36 may be omitted, and the position specifying detection element 106 and the position specifying processing unit 66 may be omitted. Needless to say, the various configurations shown in the first embodiment and the second embodiment may be applied to the load distribution detection device 3 of the present embodiment.

  Alternatively, the elastic member 20 may be made of a conductive material such as conductive rubber, and the elastic member 20 itself may be used as the movable electrode 40. In this case, it is preferable that the elastic member 20 (that is, the movable electrode 40) and the shield electrode 50 are not electrically short-circuited by providing an insulating layer between the elastic member 20 and the shield electrode 50. . Thus, by making the elastic member 20 itself the movable electrode 40, it becomes possible to further simplify the elastic member 20 and the movable electrode 40. Therefore, while further improving the strength and durability of the device, Furthermore, it becomes possible to make it thin and compact.

  In the present embodiment, the first detection element 100a composed of a pair of the first fixed electrode 32 and the movable electrode 40, the second detection element 100b composed of the pair of the second fixed electrode 34 and the movable electrode 40, and Although the example in which the position specifying detection element 106 including the pair of the third fixed electrode 36 and the movable electrode 40 is provided is shown, the first detection element 100a and the second detection element 100b are replaced by the first detection element 106a. Alternatively, the detection element 100 including the fixed electrode 32 and the second fixed electrode 34 and the movable electrode 40 may be provided. That is, it is detected that the capacitance between the two fixed electrodes 30 (the first fixed electrode 32 and the second fixed electrode 34) changes as the movable electrode 40 moves (displaces). Also good. Further, with respect to the position detection element 106, a pair of the first fixed electrode 32 and the third fixed electrode 36 and the movable electrode 40 or a pair of the second fixed electrode 34 and the third fixed electrode 36 and the movable electrode 40 is used. It may be configured by a pair, and a change in capacitance between the two fixed electrodes 30 accompanying the movement (displacement) of the movable electrode 40 may be detected.

  As described above, the load distribution detection devices 1 to 4 according to the above embodiments are load distribution detection devices that detect a load distribution in the detection surface (xy plane), and follow the detection surface. A plurality of fixed electrodes 30 arranged, a movable electrode 40 provided to face the fixed electrode 30, and a plurality of capacitance detection units (detection elements 100, first electrodes) each including a pair of the fixed electrode 30 and the movable electrode 40. A detection element 100a, a second detection element 100b, a z-direction dedicated detection element 102 and a position detection element 106), and a shield electrode 50 provided on the opposite side of the fixed electrode 30 with respect to the movable electrode 40, The fixed electrodes 30 adjacent to each other in a predetermined direction are electrically connected.

  By adopting such a configuration, the load distribution can be detected with high accuracy regardless of the application, though the configuration is simple and inexpensive. That is, by electrically connecting the fixed electrodes 50 adjacent to each other in a predetermined direction, not only can the load distribution in a wide range be detected at high speed without increasing the processing load, but also by providing the shield electrode 50, the load It is possible to detect the load distribution without being affected by the material of the external object to be applied, static electricity or the like. Furthermore, by devising the configuration and connection mode of the fixed electrode 30, it is possible to realize the detection of the surface direction load, the specification of the positions of the plurality of loads, etc., which are difficult with the conventional apparatus, with a simple and inexpensive configuration. .

  The load distribution detection devices 1 to 4 include a substantially sheet-like elastic member 20 made of an elastic material and disposed along the detection surface. The movable electrode 40 and the shield electrode 50 are provided on the elastic member 20. ing. In this way, the entire apparatus can be configured simply and inexpensively, and can be made thinner and more compact as compared with conventional apparatuses. Furthermore, since it is possible to appropriately set the movement of the movable electrode 40 and the change in electrostatic capacity associated therewith, it is possible to improve the detection accuracy.

  In the load distribution detection devices 3 and 4, the fixed electrode 30 intersects the first fixed electrode 32 to which the adjacent ones in the first direction (x direction) are electrically connected, and the first direction. And a second fixed electrode 34 that is electrically connected to each other in the second direction (the diagonal L1 direction in the load distribution detection device 3 and the y direction in the load distribution detection device 4). In this way, for example, it is possible to easily specify the position of a plurality of loads or to more simply configure the elastic member 20 that receives the load. Can be used for applications.

  In the load distribution detection device 3, a plurality of movable electrodes 40 are provided for each pair of the first fixed electrode 32 and the second fixed electrode 34, and the first direction (x direction) and the second direction are provided. Those adjacent in a third direction (y direction) different from any of (diagonal line L1 direction) are electrically connected. By doing so, it is possible to easily identify a plurality of load positions without employing complicated control.

  Further, the load distribution detection device 3 is based on a change in capacitance in a capacitance detection unit (position specifying detection element 106) composed of a pair of the second fixed electrode 34 and the movable electrode 40. There is provided position specifying processing means 66 for specifying the position. By doing in this way, specification of a some load position can be made easy and the detection of load distribution can be sped up.

  In the load distribution detection device 4, the movable electrode 40 is provided as one electrode facing all the fixed electrodes 30. By doing in this way, since it becomes possible to simplify the structure of the elastic member 20 and to raise the freedom degree of a shape, by improving an intensity | strength and durability, improving a detection precision, etc. The versatility of the apparatus can be further enhanced.

  In the load distribution detection device 4, the fixed electrodes 30 are adjacent to each other in a third direction (diagonal L2 direction) different from both the first direction (x direction) and the second direction (y direction). A third fixed electrode 36 that is electrically connected is further included. By doing in this way, since it becomes possible to identify a some load position easily, without employ | adopting complicated control, the versatility of an apparatus can further be improved.

  Further, in the load distribution detection device 4, the load in the detection surface is based on the change in the capacitance in the capacitance detection unit (position specifying detection element 106) composed of the pair of the third fixed electrode 36 and the movable electrode 40. There is provided position specifying processing means 66 for specifying the position. By doing so, it is possible to easily specify a plurality of load positions and to speed up the detection of the load distribution, thereby further enhancing the versatility of the apparatus.

  In addition, the load distribution detection device 2 generates a normal direction load (a load Fz in the z direction) that acts in the normal direction of the detection surface based on a change in capacitance in the capacitance detection unit (detection element 100). Derived and converted into a mechanical quantity for deriving a surface direction load (load Fxy in the xy plane) acting in the surface direction of the detection surface based on the change in capacitance in a plurality of capacitance detection units adjacent to each other Processing means 66 is provided. In this way, while adopting a simple configuration and control method, it is possible to detect the distribution of the surface direction load, which was difficult to detect with the conventional apparatus, together with the distribution of the normal direction load. Therefore, the versatility of the apparatus can be further enhanced. Needless to say, the load distribution detection devices 3 and 4 may be provided with a function of deriving a surface direction load.

  Further, the mechanical quantity conversion processing means 66 may derive the surface direction load by calculating the gravity center position of the change amount of the capacitance in at least three capacitance detection units close to each other. . In this case, the configuration of the electrode can be further simplified, and the derivation of the surface load can be speeded up and made highly accurate.

  The load distribution detection devices 1 to 4 are made of an insulating material and include a substantially sheet-like insulating member (substrate 10) disposed along the detection surface, and the fixed electrode 30 is provided on the insulating member. ing. By doing in this way, since it becomes unnecessary to provide an insulating layer separately from the board | substrate 10, the whole apparatus can be simplified more and thinned.

  Moreover, in the load distribution detection apparatuses 1 to 4, the insulating member (substrate 10) is made of an insulating elastic material (resin film). In this way, for example, the apparatus can be arranged along a curved surface, or the entire apparatus can be bent and deformed along an object to which a load is applied when receiving a load. Can be further enhanced.

  The load distribution detection devices 1 to 4 include a substantially sheet-like auxiliary elastic member 70 made of an elastic material and disposed on the opposite side of the elastic member 20 with respect to the insulating member (substrate 10). Also good. By doing in this way, the intensity | strength and synthesis | combination of an apparatus can be set suitably according to a use, use environment, etc.

  The auxiliary elastic member 70 may be made of an insulating material, and the fixed electrode 30 may be provided between the insulating member (substrate 10) and the auxiliary elastic member 70. In this way, while the auxiliary elastic member 70 has a simple and compact configuration, the fixed electrode 30 can be appropriately protected and an electrical short circuit with an external device can be appropriately prevented.

  Further, the load distribution detection devices 1 to 4 may include an auxiliary shield electrode 52 disposed on the opposite side of the movable electrode 40 with respect to the fixed electrode 30. By doing so, it is possible to more effectively eliminate the influence of surrounding static electricity and the like, so that the detection accuracy can be enhanced and the versatility of the apparatus can be enhanced.

  As mentioned above, although embodiment of this invention was described, the load distribution detection apparatus of this invention is not limited to above-described embodiment, In the range which does not deviate from the summary of this invention, a various change can be added. Of course.

  For example, the material of the substrate 10 is not limited to the resin, and other appropriate materials such as various insulating rubbers, glasses, ceramics, and the like can be employed. The elastic member 20 is also elastic. Other materials may be used as long as they are deformable. Further, the detection surface is not limited to the xy plane, and may be, for example, an xz plane, a predetermined slope, or the like, and the force receiving surface 21 or the entire apparatus is configured in a curved shape. The detection surface may be a curved surface. Further, the connection between the fixed electrode 30 and the movable electrode 40 and the control device 60 may be via a lead wire or the like.

  In addition, the functions and effects shown in the above embodiment are merely a list of the most preferable functions and effects resulting from the present invention, and the functions and effects of the present invention are not limited to these.

  The load distribution detection apparatus of the present invention can be used in various devices that require detection of load distribution, such as a touch panel and a robot.

1, 2, 3, 4 Load distribution detection device 10 Substrate 20 Elastic member 30 Fixed electrode 30a Fixed z-direction electrode 32 First fixed electrode 34 Second fixed electrode 36 Third fixed electrode 40 Movable electrode 40a Exclusive for z-direction Movable electrode 50 Shield electrode 52 Auxiliary shield electrode 60 Control device 64 Mechanical quantity conversion processing means 66 Position specifying processing means 70 Auxiliary elastic member 100 Detection element 100a First detection element 100b Second detection element 102 z-direction dedicated detection element 106 Position Detection element for identification

Claims (15)

A load distribution detection device that detects a load distribution in a detection plane,
A plurality of fixed electrodes arranged along the detection surface;
A movable electrode provided facing the fixed electrode;
A plurality of capacitance detectors composed of a pair of the fixed electrode and the movable electrode;
A shield electrode provided on the opposite side of the fixed electrode with respect to the movable electrode, and
The fixed electrodes are electrically connected to each other adjacent in a predetermined direction,
Load distribution detection device. It is made of an elastic material, and includes a substantially sheet-like elastic member arranged along the detection surface,
The movable electrode and the shield electrode are provided on the elastic member,
The load distribution detection apparatus according to claim 1. The fixed electrode is
A first fixed electrode in which the ones adjacent in the first direction are electrically connected;
A second fixed electrode that is electrically connected to each other adjacent to the second direction intersecting the first direction,
The load distribution detection device according to claim 1 or 2. A plurality of the movable electrodes are provided for each pair of the first fixed electrode and the second fixed electrode, and are adjacent to a third direction different from both the first direction and the second direction. It is characterized in that things are electrically connected to each other,
The load distribution detection apparatus according to claim 3. It comprises a position specifying processing means for specifying a position of a load in the detection surface based on a change in capacitance in the capacitance detecting unit comprising the pair of the second fixed electrode and the movable electrode. To
The load distribution detection apparatus according to claim 4. The movable electrode is provided as one electrode facing all the fixed electrodes,
The load distribution detection apparatus according to claim 3. The fixed electrode further includes a third fixed electrode that is electrically connected to ones adjacent to each other in a third direction different from both the first direction and the second direction.
The load distribution detection apparatus according to claim 6. And a position specifying processing means for specifying a position of a load in the detection surface based on a change in capacitance in the capacitance detecting unit comprising the pair of the third fixed electrode and the movable electrode. To
The load distribution detection apparatus according to claim 7. Based on the change in capacitance in the capacitance detection unit, a normal direction load acting in the normal direction of the detection surface is derived, and the capacitance in the plurality of capacitance detection units close to each other is derived. Based on a change, characterized in that it comprises a mechanical quantity conversion processing means for deriving a surface direction load acting on the surface direction of the detection surface,
The load distribution detection device according to any one of claims 1 to 8. The mechanical quantity conversion processing means derives the plane direction load by calculating the center of gravity position of the amount of change in capacitance in at least three capacitance detection units adjacent to each other.
The load distribution detection apparatus according to claim 9. Consists of an insulating material, comprising a substantially sheet-like insulating member disposed along the detection surface,
The fixed electrode is provided on the insulating member,
The load distribution detection apparatus according to any one of claims 1 to 10. The insulating member is composed of an insulating elastic material,
The load distribution detection device according to claim 11. It is made of an elastic material and includes a substantially sheet-like auxiliary elastic member disposed on the opposite side of the elastic member with respect to the insulating member.
The load distribution detection device according to claim 11 or 12. The auxiliary elastic member is made of an insulating material,
The fixed electrode is provided between the insulating member and the auxiliary elastic member,
The load distribution detection device according to claim 13. The auxiliary shield electrode disposed on the opposite side of the movable electrode with respect to the fixed electrode,
The load distribution detection apparatus according to any one of claims 1 to 14.

Images