JP2019152599A - Sensor, sensor control method, and control program - Google Patents

Abstract

To provide a sensor, a sensor control method, and a control program of a simple structure with which it is possible to detect displacement in a compression direction and displacement in a shear direction more accurately than possible before.SOLUTION: A sensor 100 comprises a plurality of independent electrodes 130, a common electrode 140, a dielectric substance 150, a detection unit 171 for detecting electrostatic capacitance, a compression displacement calculation unit 172 for calculating the amount of compression displacement on the basis of the sum of detected electrostatic capacitances, and a shear displacement calculation unit 173 for calculating the amount of shear displacement on the basis of the sum of detected electrostatic capacitances. When the common electrode 140 is at an initial position, each independent electrode 131 includes a region that faces a common counterface surface 141 and a region that does not, and in at least a portion of a range in which the common electrode 140 is movable, the sum total of area of the common counterface surface 141 that faces a plurality of independent counterface surfaces 131 is constant.SELECTED DRAWING: Figure 2

Description

  The present disclosure relates to a sensor, a sensor control method, and a control program, and more particularly, to a sensor that detects displacement of an electrode, a sensor control method, and a control program.

  There is known a sensor that detects a force applied to an electrode by detecting a relative displacement between the electrodes from a change in capacitance between the electrodes.

  For example, the tactile sensor of Patent Document 1 includes a compression force detection unit that detects a compression force along the compression direction and a shear force detection unit that detects a shear force in a shear direction orthogonal to the compression direction. Each of the compressive force detector and the shear force detector is configured by sandwiching a dielectric layer between two parallel flat plates. The compressive force detector detects the compressive force according to the distance between the two flat plates. The shearing force detection unit detects the shearing force according to the deviation along the direction in which the two flat plates spread.

  Patent Document 2 discloses a tactile sensor including a plurality of sets of parallel first electrodes and second electrodes. The relative positions of the first electrode and the second electrode differ between sets. When a compressive force is applied, the distance between the first electrode and the second electrode changes while the area where the first electrode and the second electrode overlap remains constant. When a shearing force is applied, the area where the first electrode and the second electrode overlap changes while the distance between the first electrode and the second electrode remains constant. As a result, the compression force and the shearing force can be detected by a common electrode by detecting the capacitance for each set.

Japanese Patent Application Laid-Open No. 2010-122018 Japanese Patent Application Laid-Open No. 2014-115282 JP 2015-45552 specification

  However, in the tactile sensor disclosed in Patent Document 1 in which two sensors, ie, a compressive force detector and a shear force detector, are stacked, a force in the shearing direction is applied to the two flat plates of the compressive force detector. The force alone cannot be measured. Furthermore, since a compressive force is applied to the two flat plates of the shear force detection unit, it is impossible to strictly measure only the shear force.

  Moreover, in the tactile sensor of patent document 2, since each set requires the 1st electrode and the 2nd electrode 1 each, a structure is complicated and a large area is required. Moreover, since it is necessary to arrange | position a 1st electrode and a 2nd electrode correctly with a some set, manufacture is difficult. Moreover, since there are many electrodes, the consideration which prevents a disconnection is needed.

  Therefore, an object of the present disclosure is to provide a sensor, a sensor control method, and a control program having a simple structure that can detect a displacement in a compression direction and a displacement in a shearing direction more accurately than conventional ones.

  The sensor according to the first aspect of the present disclosure includes a plurality of independent electrodes, and a common electrode supported so as to be displaceable in a compression direction and a shearing direction orthogonal to the compression direction from an initial position with respect to the plurality of independent electrodes; Based on a dielectric located between the common electrode and the plurality of independent electrodes, a detection unit for detecting capacitance between each of the common electrode and the plurality of independent electrodes, and the sum of the detected capacitances A compression displacement amount calculation unit for calculating a relative compression displacement amount between the common electrode and the plurality of independent electrodes in the compression direction, and the common electrode and the plurality of independent electrodes in the shear direction based on the detected capacitance A shear displacement amount calculation unit that calculates a relative shear displacement amount, and each of the plurality of independent electrodes has an independent facing surface that extends perpendicular to the compression direction, and all the independent facing surfaces are the same. Spread along the plane of the common electrode, compressed When the common electrode is in the initial position, each of the independent facing surfaces includes a region facing the common facing surface and a region not facing in the compression direction, and the common electrode can move. In at least a part of such a range, the total of the areas facing the plurality of independent facing surfaces among the common facing surfaces is constant.

  According to the sensor according to the first aspect, since the electrostatic capacitances of a plurality of common independent electrodes are used in the calculation of the compression displacement amount and the shear displacement amount, the compression displacement amount and the shear displacement amount are separately calculated. Compared with the prior art that prepares the electrode, it is possible to accurately detect the amount of compressive displacement and the amount of shear displacement with a simple structure. Further, since it is not necessary to overlap the dielectric for detecting the amount of compressive displacement and the dielectric for detecting the amount of shear displacement, the amount of compressive displacement and the amount of shear displacement can be accurately distinguished.

  The sensor according to the second aspect of the present disclosure is the sensor according to the first aspect, wherein the first section and the second section divided by the first virtual center line and the second virtual center line intersecting the first virtual center line. One independent electrode is located in each of the compartment, the third compartment, and the fourth compartment, the first virtual center line is parallel to the first shear direction orthogonal to the compression direction, and the second virtual center line is compressed A first independent electrode that is parallel to a second shear direction perpendicular to the direction and the first shear direction and is an independent electrode located in the first section; and a second independent electrode that is an independent electrode located in the second section; Are arranged in the first shear direction, and the third independent electrode, which is an independent electrode located in the third section, and the fourth independent electrode, which is an independent electrode located in the fourth section, are arranged in the first shear direction. The electrode and the third independent electrode are arranged in the second shear direction, and the second independent electrode and the fourth independent electrode are Aligned in the shear direction, the detection unit detects a first capacitance that is a capacitance between the first independent electrode and the common electrode, and the detection unit detects the static capacitance between the second independent electrode and the common electrode. A second electrostatic capacity that is a capacitance is detected, a detection unit detects a third electrostatic capacity that is a capacitance between the third independent electrode and the common electrode, and a detection unit is the fourth independent electrode. A fourth capacitance that is a capacitance between the first electrode, the second electrode, the third capacitor, and the fourth capacitor. The amount of compressive displacement is calculated based on the sum of the capacitance, and the shear displacement amount calculation unit calculates the sum of the first capacitance and the third capacitance, the second capacitance, and the fourth capacitance. A first shear displacement amount, which is a shear displacement amount in the first shear direction, is calculated based on the sum of the first capacitance and the second capacitance. 3 capacitance and 4 on the basis of the sum of the capacitance, and calculates a second shear displacement is shear displacement amount in the second shear direction.

  According to the sensor of the second aspect, the displacement amount in multiple directions, that is, the compression displacement amount, the first shear displacement amount in the first shear direction, and the second shear direction in a simple structure as compared with the prior art. The second shear displacement amount can be accurately detected.

  The sensor according to the third aspect of the present disclosure is the sensor according to the second aspect, wherein the independent facing surface of the first independent electrode and the independent facing surface of the third independent electrode are lines with respect to the first virtual center line. The independent opposing surface of the second independent electrode and the independent opposing surface of the fourth independent electrode are axisymmetric with respect to the first virtual center line, and the independent opposing surface of the first independent electrode and the second independent electrode Are independent of the second virtual center line, and the independent opposing surface of the third independent electrode and the independent opposing surface of the fourth independent electrode are line symmetrical with respect to the second virtual center line. It is.

  According to the sensor according to the third aspect, since the independent facing surfaces of the plurality of independent electrodes have symmetry, manufacturing is easier than in the asymmetric case, and the amount of displacement can be easily calculated.

  A sensor according to a fourth aspect of the present disclosure is the sensor according to the third aspect, wherein each independently facing surface has a rectangle having two sides parallel to the first shearing direction and two sides parallel to the second shearing direction. The common facing surface is a rectangle having two sides parallel to the first shearing direction and two sides parallel to the second shearing direction.

  According to the sensor of the fourth aspect, since the plurality of independent electrodes are rectangular, manufacturing is easier than in a complicated shape, and calculation of the capacitance is easy.

  A sensor according to a fifth aspect of the present disclosure is the sensor according to the third aspect, wherein each independent facing surface has a fan shape having a common virtual center point, the common facing surface is circular, and the common electrode Is at the initial position, the center point of the common facing surface overlaps the virtual center point in the compression direction.

  According to the sensor of the fifth aspect, since the plurality of independent electrodes are fan-shaped, manufacturing is easier than in a complicated shape, and calculation of capacitance is easy. Further, when the common electrode is displaced from the initial position, the maximum displaceable amount can be made the same in any direction.

  The sensor according to a sixth aspect of the present disclosure is the sensor according to the third aspect, wherein the common facing surface is parallel to the first shearing direction and extends from the first section into the second section, A second edge extending parallel to the second shear direction and extending from the first compartment into the third compartment; and a curved edge; when the common electrode is in the initial position, the curved edge is within the first compartment. A 90 ° center defined between the first and second shear directions, the curved edge connecting one end of the first edge and one end of the second edge. An area in the first section of the common facing surface when the fan has a corner, the curved edge is convex outward in a plane orthogonal to the compression direction, and the common electrode is in the initial position. Has a shape that continuously extends from the first edge and the curved edge to the third section in the second shear direction, and the common electrode is in the initial position. A region in the first section of the common facing surface has a shape that continuously extends from the second edge and the curved edge to the second section in the first shear direction, and the independent facing surface of the first independent electrode is A first outer edge parallel to the first edge, a second outer edge parallel to the second edge, and a curved outer edge. The curved outer edge includes one end of the first outer edge and the second outer edge. The curved outer edge is in the shape of a fan having a central angle of 90 degrees defined between the first shearing direction and the second shearing direction, and the curved outer edge is in a plane perpendicular to the compression direction. In which the independent facing surface of the first independent electrode continuously extends from the first outer edge and the curved outer edge toward the third section in the second shear direction, The independent facing surface of one independent electrode is continuously widened from the second outer edge and the curved outer edge toward the second section in the first shear direction. Having a shape, when the common electrode is in the initial position, in the compression direction, the fan-shaped virtual center point of the curved edge overlaps the fan-shaped virtual center point of the curved outer edge, and when the common electrode is in the initial position, The distance between the first outer edge and the first edge in the second shear direction is the same as the distance between the second outer edge and the second edge in the first shear direction, and the common electrode is in the initial position. Sometimes, the difference between the radius of the curved outer edge and the radius of the curved edge is the same as the separation distance between the first outer edge and the first edge in the second shear direction.

  According to the sensor of the sixth aspect, when the common electrode is displaced from the initial position, the maximum displaceable amount can be made the same in any direction.

  The sensor according to a seventh aspect of the present disclosure is the sensor according to any one of the first to sixth aspects, wherein the dielectric is an elastic body that fills a space between the plurality of independent electrodes and the common electrode in the compression direction. The common electrode is supported by the dielectric so as to be relatively displaceable in the compression direction and the shear direction from the initial position with respect to the plurality of independent electrodes.

  According to the sensor of the seventh aspect, the configuration becomes simple compared to the case where the common electrode is supported by a material different from the dielectric. Further, since the dielectric is an elastic body, the common electrode can be automatically returned to the original position when the force is released.

  A sensor according to an eighth aspect of the present disclosure is the sensor according to the seventh aspect, wherein the compression applied from the common electrode to the dielectric in the compression direction based on the amount of compressive displacement and the material properties of the dielectric. Applied to the dielectric in the shear direction from the common electrode based on the compression force calculation unit for calculating the force, the compression displacement, the first shear displacement, the second shear displacement, and the material properties of the dielectric And a shear force calculation unit that calculates a shear force.

  According to the sensor of the eighth aspect, since the electrostatic capacity of a plurality of common independent electrodes is used in the calculation of the compression force and the shear force, separate electrodes are prepared for the calculation of the compression force and the shear force. Therefore, it is possible to accurately detect the compressive force and the shear force with a simple structure as compared with the conventional technology. Further, unlike the prior art, it is not necessary to overlap the dielectric for detecting the compressive force and the dielectric for detecting the shear force, so that the compressive force and the shear force can be accurately distinguished.

  A sensor according to a ninth aspect of the present disclosure is the sensor according to the eighth aspect, wherein a dielectric constant calculating unit that calculates a dielectric constant of a dielectric based on a capacitance when the common electrode is at an initial position; An elastic modulus calculation unit that calculates an elastic modulus from a calculated dielectric constant based on predetermined relationship information representing a relationship between a dielectric constant and an elastic modulus of a dielectric, and a compressive force The material property used for the calculation includes the elastic modulus, and the compressive force calculating unit calculates the compressive force using the calculated elastic modulus.

  According to the sensor of the ninth aspect, it is possible to accurately detect the compressive force in consideration of the change in the elastic modulus of the dielectric due to temperature or the like.

  A sensor according to a tenth aspect of the present disclosure is the sensor according to any one of the seventh to ninth aspects, further comprising a stopper that limits a movement range of the common electrode with respect to the plurality of independent electrodes, The body is elastically deformable within the movement range.

  According to the sensor of the tenth aspect, it is possible to prevent plastic deformation of the dielectric and maintain accurate detection.

  A sensor according to an eleventh aspect of the present disclosure is the sensor according to any one of the first to tenth aspects, wherein the plurality of electrodes connected to each of the first substrate, the second substrate, and the plurality of independent electrodes. A sensor comprising a first wiring and a second wiring connected to a common electrode, wherein at least a part of each of the plurality of first wirings and the plurality of independent electrodes are fixed to the first substrate, At least a part of the second wiring and the common electrode are fixed to the second substrate.

  According to the sensor of the eleventh aspect, since the plurality of first wirings and the plurality of independent electrodes are fixed to the first substrate, it is easy to prevent disconnection. Further, since the second wiring and the common electrode are fixed to the second substrate, it is easy to prevent disconnection.

  A sensor according to a twelfth aspect of the present disclosure is the sensor according to any one of the seventh to ninth aspects, wherein a stopper that limits a movement range of the common electrode with respect to the plurality of independent electrodes, and a stopper fixed to the stopper. A sensor comprising: a substrate; a plurality of first wirings connected to each of the plurality of independent electrodes; and a second wiring extending between the first substrate and the common electrode, wherein the dielectric moves It is elastically deformable within the range, and at least a part of each of the plurality of first wirings is fixed to the first substrate, and at least a part of the second wiring is fixed to the stopper.

  According to the sensor of the twelfth aspect, since the first wiring and the second wiring are fixed, it is easy to prevent disconnection.

  A sensor according to a thirteenth aspect of the present disclosure is the sensor according to any one of the first to twelfth aspects, includes an auxiliary electrode, and the auxiliary electrode has an auxiliary facing surface that extends perpendicular to the compression direction, The area of the auxiliary facing surface is smaller than the area of the common facing surface, and the entire auxiliary facing surface faces the common facing surface in the compression direction.

  According to the sensor of the thirteenth aspect, since the entire auxiliary facing surface faces the common facing surface in the compression direction, the capacitance between the auxiliary electrode and the common electrode is constant regardless of the displacement in the shearing direction. Thus, the displacement in the compression direction can be detected stably.

  A sensor control method according to a fourteenth aspect of the present disclosure is a sensor control method executed by a sensor, wherein the sensor includes a plurality of independent electrodes and a compression direction and a compression direction from an initial position with respect to the plurality of independent electrodes. A common electrode supported so as to be displaceable in a shearing direction orthogonal to the first electrode, and a dielectric positioned between the common electrode and the plurality of independent electrodes, and each of the plurality of independent electrodes is orthogonal to the compression direction. Each having an independent facing surface that spreads out, all the independent facing surfaces spread along the same plane, the common electrode has a common facing surface that extends perpendicular to the compression direction, and the common electrode is in the initial position. The independent facing surface includes a region facing the common facing surface in the compression direction and a region not facing the common facing surface, and faces a plurality of independent facing surfaces of the common facing surface in at least a part of the movable range of the common electrode. Of area The meter is constant and the sensor control method is based on the sensor detecting the capacitance between the common electrode and each of the plurality of independent electrodes, and the sensor is based on the sum of the detected capacitances. Calculating the relative amount of compressive displacement between the common electrode and the plurality of independent electrodes in the compression direction, and the sensor detects the common electrode and the plurality of independent electrodes in the shear direction based on the detected capacitance. Calculating a relative amount of shear displacement.

  A control program according to a fifteenth aspect of the present disclosure is a control program that causes a computer to execute the sensor control method according to the fourteenth aspect.

  According to the present disclosure, it is possible to provide a sensor having a simple structure, a sensor control method, and a control program that can detect a displacement in a compression direction and a displacement in a shear direction more accurately than in the past.

It is a perspective view of the sensor of a 1st embodiment. It is a top view of the sensor shown in FIG. FIG. 3 is a cross-sectional view of the sensor in a cross section passing through line 3-3 in FIG. It is a top view for demonstrating the positional relationship of the independent electrode shown in FIG. 2, and a common electrode. It is a block diagram which shows the independent electrode shown in FIG. 2, a common electrode, and a control apparatus. It is a flowchart for demonstrating the sensor control method which the sensor shown in FIG. 1 implements. It is a flowchart for demonstrating the calibration method which the sensor shown in FIG. 1 implements. It is a top view of a common electrode of a 2nd embodiment, an independent electrode, and a dielectric. It is a top view of the common electrode of 3rd Embodiment, an independent electrode, and a dielectric material. It is a top view of a common electrode of a 4th embodiment, an independent electrode, and a dielectric. It is a top view of a common electrode of a 5th embodiment, an independent electrode, and an auxiliary electrode. It is a block diagram which shows the independent electrode of 5th Embodiment, a common electrode, an auxiliary electrode, and a control apparatus.

  Hereinafter, sensors according to the first to fifth embodiments will be described. In the sensor of the first embodiment, the hundreds of each component is represented by 1. Similarly, each component of the second to fifth embodiments is represented by 2 to 5 in hundreds. Unless otherwise noted, components that differ by only a hundred in different embodiments each represent a similar component. In the second and subsequent embodiments, differences from the first embodiment will be mainly described.

(First embodiment)
FIG. 1 is a perspective view of a sensor 100 according to the present embodiment. FIG. 2 is a plan view of the sensor 100 shown in FIG. FIG. 3 is a cross-sectional view of the sensor 100 taken along a line 3-3 in FIG. The sensor 100 shown in FIG. 1 detects the magnitude of the force applied to the electrodes by detecting the relative displacement amount between the electrodes. A force is applied to the electrode by, for example, a human finger.

  In this specification, the x direction, the y direction, and the z direction orthogonal to each other are defined. The x direction is expressed without distinguishing the x1 direction and the x2 direction that are opposite to each other. The y direction represents the y1 direction and the y2 direction that are opposite to each other without distinction. The z direction represents the z1 direction and the z2 direction that are opposite to each other without distinction. Further, the z1 side may be expressed as the upper side and the z2 side may be expressed as the lower side. These directions are defined for convenience in order to explain the relative positional relationship, and do not limit the directions in actual use. Regardless of whether there is a description of “substantially”, the shape of the component is a strict geometric shape based on the described expression as long as the technical idea of the embodiment disclosed in this specification is realized. It is not limited.

  The z2 direction is called the compression direction, the x direction is called the first shear direction, and the y direction is called the second shear direction. The first shearing direction and the second shearing direction may be referred to as the shearing direction without distinction. The first shear direction is orthogonal to the compression direction. The second shear direction is orthogonal to the compression direction and the first shear direction. That is, the compression direction and the shearing direction are orthogonal. The shear direction includes a combination of the first shear direction and the second shear direction.

  As shown in FIG. 2, the sensor 100 includes a first substrate 110, a frame-shaped stopper 111 fixed to the first substrate 110, a plurality of first wirings 112 connected to the first substrate 110, and the first substrate 110. A second substrate 120 separated from the second substrate 120, a second wiring 121 connected to the second substrate 120, and a first independent electrode 130-1 to a fourth independent electrode 130-4 fixed to the first substrate 110 (hereinafter, not distinguished). 3), a common electrode 140 fixed to the second substrate 120, a dielectric 150 (FIG. 3) positioned between the four independent electrodes 130 and the common electrode 140, and a sensor. And a control device 160 for controlling the operation of 100.

(substrate)
As shown in FIG. 1, the first substrate 110 is a circuit substrate whose base material is a flat hard material that extends parallel to the xy plane. The second substrate 120 is a circuit substrate whose base material is a flat hard material that extends parallel to the xy plane. The second substrate 120 is a rectangle having two sides parallel to the x direction and two sides parallel to the y direction when viewed from the z direction. The second substrate 120 is positioned away from the first substrate 110 in the z1 direction.

(Stopper)
As shown in FIG. 1, the stopper 111 is fixed to the first substrate 110 and extends from the first substrate 110 in the z1 direction. The stopper 111 is made of hard resin, for example. As shown in FIG. 2, the stopper 111 defines a rectangular space having two sides parallel to the x direction and two sides parallel to the y direction when viewed from the z direction. As shown in FIG. 1, the space inside the stopper 111 is a rectangular parallelepiped surrounded by two planes parallel to the yz plane and two planes parallel to the zx plane, and is open in the z1 direction. The stopper 111 limits the movement range of the common electrode 140 with respect to the plurality of independent electrodes 130.

(Independent electrode)
As shown in FIG. 3, the four independent electrodes 130 are fixed to the z1 side surface of the first substrate 110 in the space surrounded by the stopper 111. Each independent electrode 130 is a thin-film flat plate metal that extends parallel to the xy plane.

  FIG. 4 is a plan view for explaining the positional relationship between the four independent electrodes 130 and the common electrode 140. When viewed from the z direction, the first virtual center line 101 parallel to the x direction and the second virtual center line 102 parallel to the y direction and intersecting the first virtual center line 101 make the space a first section 103-1. And the second section 103-2, the third section 103-3, and the fourth section 103-4 (hereinafter, sometimes referred to as section 103 without distinction). The four sections 103 are a virtual concept, and there is no need to actually have a partition.

  One independent electrode 130 is located in each of the four compartments 103. The first independent electrode 130-1 is located in the first section 103-1. The second independent electrode 130-2 is located in the second section 103-2. The third independent electrode 130-3 is located in the third section 103-3. The fourth independent electrode 130-4 is located in the fourth section 103-4. The first independent electrode 130-1 and the second independent electrode 130-2 are arranged in the x direction. The third independent electrode 130-3 and the fourth independent electrode 130-4 are arranged in the x direction. The first independent electrode 130-1 and the third independent electrode 130-3 are arranged in the y direction. The second independent electrode 130-2 and the fourth independent electrode 130-4 are arranged in the y direction.

  The first independent electrode 130-1 has a first independent facing surface 131-1. The second independent electrode 130-2 has a second independent facing surface 131-2. The third independent electrode 130-3 has a third independent facing surface 131-3. The fourth independent electrode 130-4 has a fourth independent facing surface 131-4. Hereinafter, the first independent facing surface 131-1 to the fourth independent facing surface 131-4 may be referred to as the independent facing surface 131 without being distinguished. That is, each of the plurality of independent electrodes 130 has an independent facing surface 131 that extends perpendicular to the z direction and faces the z1 direction. All the independent facing surfaces 131 extend along the same plane. Each independent facing surface 131 is a rectangle having two sides parallel to the x direction and two sides parallel to the y direction.

  The first independent facing surface 131-1 and the third independent facing surface 131-3 are line symmetric with respect to the first virtual center line 101. The second independent facing surface 131-2 and the fourth independent facing surface 131-4 are line symmetric with respect to the first virtual center line 101. The first independent facing surface 131-1 and the second independent facing surface 131-2 are line symmetric with respect to the second virtual center line 102. The third independent facing surface 131-3 and the fourth independent facing surface 131-4 are line symmetric with respect to the second virtual center line 102.

  The overall outer shape of the four independent facing surfaces 131 is a rectangle having two sides parallel to the x direction and two sides parallel to the y direction. The four independent facing surfaces 131 are close to each other and are separated by a thin cross-shaped insulating region along the first virtual center line 101 and the second virtual center line 102. In another example, the corners of the independent facing surface 131 may be rounded.

(Common electrode)
As shown in FIG. 3, the common electrode 140 is fixed to the z2 side surface of the second substrate 120 in the space surrounded by the stopper 111. The common electrode 140 is a thin-film flat plate metal that extends parallel to the xy plane. The common electrode 140 has a common facing surface 141 that extends in a direction perpendicular to the z direction and faces the z2 direction. The common facing surface 141 is a rectangle having two sides parallel to the x direction and two sides parallel to the y direction. When viewed from the z direction, the outer shape of the common facing surface 141 is smaller than the entire outer shape of the four independent facing surfaces 131.

  1 to 3, the common electrode 140 is in the initial position. The common electrode 140 shown by the solid line in FIG. 4 is in the initial position. In the initial position, the center of gravity of the common facing surface 141 overlaps the entire center of gravity of the four independent facing surfaces 131 in the z direction. When the common electrode 140 is in the initial position, each independent facing surface 131 includes a region facing the common facing surface 141 and a region not facing in the z direction. In the initial position, the areas of the opposing regions of the independent facing surfaces 131 and the common facing surface 141 are equal.

(Dielectric)
As shown in FIG. 3, the dielectric 150 is located between the common electrode 140 and the four independent electrodes 130 in the z direction. The dielectric 150 is an elastic body that fills the space between the common electrode 140 and the region of the four independent electrodes 130 facing the common electrode 140 in the z direction. As shown in FIG. 1, the dielectric 150 is generally a rectangular parallelepiped surrounded by two surfaces parallel to the xy plane, two surfaces parallel to the yz plane, and two surfaces parallel to the zx plane.

  As shown in FIG. 2, when viewed from the z direction, the dielectric 150 extends slightly outward from the common electrode 140 on both sides in the x direction and both sides in the y direction. The dielectric 150 does not reach the inner surface of the stopper 111 on both sides in the x direction and the y direction.

  The common electrode 140 can be relatively displaced from the initial position with respect to the four independent electrodes 130 by the dielectric 150 in the x direction, the y direction, the z direction, and the combined direction of the x direction, the y direction, and the z direction. Supported. When the common electrode 140 is pushed in the z2 direction, the dielectric 150 is compressed. When the common electrode 140 is pushed in a direction perpendicular to the z direction, the z1 side surface of the dielectric 150 is displaced in the direction of the force while the z2 side surface of the dielectric 150 is fixed to the four independent electrodes 130. . When the force is released, the common electrode 140 returns to the initial position.

  The dielectric 150 can be elastically deformed within the movement range of the common electrode 140 limited by the stopper 111. That is, the movement range of the common electrode 140 is limited by the stopper 111 so that the dielectric 150 is not plastically deformed. As shown in FIG. 3, before and after the movement, the independent facing surface 131 and the common facing surface 141 are generally kept parallel.

  A two-dot chain line common electrode 140 shown in FIG. 4 shows an exemplary position after the solid line common electrode 140 is moved. The entire surface of the common facing surface 141 always faces the independent facing surface 131 before and after the movement regardless of the amount of movement. In at least a part of the movable range of the common electrode 140, the total area of the common facing surface 141 facing the plurality of independent facing surfaces 131 is substantially constant. That is, in this embodiment, the gap between the independent electrodes 130 is negligible. In another example, in the calculation, the area of the gap may be subtracted from the area of the common facing surface 141 facing the four independent facing surfaces 131.

(Control device)
As shown in FIG. 1, the control device 160 is fixed on the first substrate 110 and electrically performs the operation described below in the sensor 100. The controller 160 may be in other positions and may be distributed in multiple positions.

(wiring)
As shown in FIG. 2, each of the four first wirings 112 connects each of the four independent electrodes 130 to the control device 160. The first wiring 112 is, for example, a metal wiring. The entire first wiring 112 is fixed to the first substrate 110. In another example, at least a part of each of the four first wirings 112 is fixed to the first substrate 110.

  The second wiring 121 extends between the first substrate 110 and the common electrode 140 and connects the common electrode 140 and the control device 160. At least a part of the second wiring 121 is fixed to the second substrate 120. At least a part of the second wiring 121 is fixed to the stopper 111.

(Size)
The components in each drawing are exaggerated for easy understanding. In one example, the area of the common facing surface 141 is 10 mm × 10 mm. In one example, the thickness of the dielectric 150 in the z direction is 1 mm.

(Details of control device)
FIG. 5 is a block diagram showing the independent electrode 130, the common electrode 140, and the control device 160. The control device 160 includes a detection circuit 161, a storage device 162, and an arithmetic processing device 163.

  Hereinafter, referring to FIG. 4 together with FIG. 5, the common electrode 140 is displaced by the displacement amount A in the x direction from the initial position of the solid line to the position after the movement of the two-dot chain line, and is displaced by the displacement amount B in the y direction. An example of calculation in this case will be described as an example. The dielectric constant of the dielectric 150 (FIG. 3) is expressed as ε. The area of the common facing surface 141 (FIG. 3) is represented as S. As shown in FIG. 4, the width of the common facing surface 141 in the x direction is represented by 2w. The length of the common facing surface 141 in the y direction is expressed as 2h. ε, S, w, h are set in advance.

(Detection circuit)
The detection circuit 161 shown in FIG. 5 detects the amount of charge accumulated between each independent electrode 130 and the common electrode 140 when a voltage is applied between each independent electrode 130 and the common electrode 140. The detection circuit 161 determines, based on the detected charge amount, a first capacitance (= C1) that is a capacitance between the first independent electrode 130-1 and the common electrode 140, and a second independent electrode 130-2. And a second capacitance (= C2) that is a capacitance between the third independent electrode 130-3 and the common electrode 140 (= C2). = C3) and a signal representing a fourth capacitance (= C4) that is a capacitance between the fourth independent electrode 130-4 and the common electrode 140 is detected. In one example, the detection method is the same as the capacitance detection method in the capacitive touch pad.

(Storage device)
The storage device 162 stores a control program 164 and relationship information 165. The control program 164 is read by the arithmetic processing device 163 and causes the arithmetic processing device 163 to implement a function for performing a part of the sensor control method and the calibration method, and other functions. When the arithmetic processing device 163 performs various functions, the storage device 162 is controlled by the arithmetic processing device 163 and stores necessary information as appropriate. The relationship information 165 represents the relationship between the dielectric constant and elastic modulus of the dielectric 150 (FIG. 1), as will be described later.

  The storage device 162 includes a volatile or non-volatile storage device such as a ROM (Read only memory) and a RAM (Random access memory). The storage device 162 may include a non-transitory tangible storage medium such as an optical disk or a USB memory. The storage device 162 may be removable or non-removable.

(Arithmetic processing unit)
The arithmetic processing device 163 reads out and executes the control program 164 stored in the storage device 162, whereby a detection unit 171, a compression displacement amount calculation unit 172, a shear displacement amount calculation unit 173, a dielectric constant calculation unit 176, which will be described later, And a computer functioning as the elastic modulus calculation unit 177. Note that the arithmetic processing unit 163 performs at least a part of processing on dedicated hardware such as an application specific integrated circuit (ASIC) or other circuits that can implement each function described in the present embodiment. It may be executed with.

(Detection unit)
The detection unit 171 detects the electrostatic capacitance (that is, C1, C2, C3, and C4) between the common electrode 140 and each of the four independent electrodes 130 by controlling the detection circuit 161 described above.

(Compression displacement calculation unit)
The compression displacement amount calculation unit 172 calculates the relative displacement amounts of the common electrode 140 and the four independent electrodes 130 in the z direction based on the detected capacitance sum (ie, C1 + C2 + C3 + C4).

The compression displacement amount d represents the displacement amount of the common electrode 140 in the z2 direction from the initial position. The distance between the independent facing surface 131 and the common facing surface 141 in the z direction at the initial position is d1 (equal to the thickness of the dielectric 150 before deformation), and the independent facing surface 131 and the common facing surface 141 in the z direction after the movement. Is the distance d2 (equal to the thickness of the dielectric 150 after deformation), the amount of compressive displacement d (equal to the amount of change in the thickness of the dielectric 150) is expressed as in equation (1). . D1 at the initial position is set in advance. The sum C of the electrostatic capacitance at the initial position is expressed as shown in Equation (2). ε represents the dielectric constant of the dielectric 150. The sum CAB of the capacitance after movement is expressed as shown in Equation (3).
d = d1-d2 Formula (1)
C = ε × S / d1 Formula (2)
CAB = ε × S / d2 Equation (3)
Therefore, the compression displacement amount d is calculated as in Expression (4).
d = d1 (CAB-C) / CAB (4)

(Shear displacement calculation unit)
The shear displacement amount calculation unit 173 calculates the shear displacement amount (that is, A and B) based on the detected capacitance (that is, C1, C2, C3, and C4). The shear displacement amount is a relative displacement amount between the common electrode 140 and the four independent electrodes 130 in each of the x direction and the y direction. The first shear displacement amount (= A) is a shear displacement amount in the x direction calculated based on the sum of C1 and C3 (= CL) and the sum of C2 and C4 (= CR). The second shear displacement amount (= B) is a shear displacement amount in the y direction calculated based on the sum of C1 and C2 (= CU) and the sum of C3 and C4 (= CB).

The sum CL of C1 and C3 is expressed as shown in Equation (5). The sum CR of C2 and C4 is expressed as in Equation (6). The capacitance CAB after the movement is expressed as shown in Equation (7). Using formula (5), formula (6), and formula (7), CL-CR is expressed as formula (8).
CL = C1 + C3 = ε2h × (w + A) / (d1−d) (5)
CR = C2 + C4 = ε2h × (w−A) / (d1−d) Equation (6)
CAB = ε2h × 2w / (d1−d) (7)
CL-CR = ε2h × 2A / (d1-d) = CAB × A / w (8)

Therefore, the first shear displacement amount A is calculated as in equation (9). Similarly, the second shear displacement amount B is calculated as in Expression (10).
A = w × (CL-CR) / CAB (9)
B = h × (CU−CB) / CAB (10)
Accordingly, the total shear displacement q is calculated as shown in Equation (11). Note that sqrt calculates the square root of the expression in parentheses.
q = sqrt (A ² + B ² ) (11)

(Compression force calculation unit)
The compressive force calculator 174 calculates the compressive force f1 applied in the z2 direction from the common electrode 140 to the dielectric 150 based on the amount of compressive displacement d and the material characteristics of the dielectric 150. The material properties used for calculating the compressive force include the elastic modulus E of the dielectric 150. The elastic modulus E is set in advance.

The elastic modulus E of the dielectric 150 is expressed as in Expression (12). The stress σ1 in the compression direction applied to the dielectric 150 is expressed as in Expression (13). The compressive strain o of the dielectric 150 is expressed as in Expression (14).
E = σ1 / o Equation (12)
σ1 = f1 / S (13)
o = d / d1 Formula (14)
Accordingly, the compressive force f1 is calculated as in Expression (15) from Expression (12), Expression (13), and Expression (14).
f1 = E × S × d / d1 (15)

(Shearing force calculation unit)
The shear force calculation unit 175 performs the z-direction from the common electrode 140 to the dielectric 150 based on the compression displacement d, the first shear displacement A, the second shear displacement B, and the material characteristics of the dielectric 150. The shearing force f2 applied in the orthogonal direction is calculated. The material properties used for calculating the shear force include the shear modulus G of the dielectric 150.

The shear elastic modulus G of the dielectric 150 is expressed as in Expression (16). The shear stress σ2 is expressed as in Expression (17).
G = σ2 × d2 / q (16)
σ2 = f2 / S (17)
Therefore, the total shearing force f2 is calculated as in Expression (18) from Expression (16), Expression (17), and Expression (1). The first shear force fx, which is the shear force in the x direction, is calculated as in Expression (19). The second shear force fy, which is a shear force in the y direction, is calculated as in Expression (20).
f2 = G × S × sqrt (A ² + B ² ) / (d1−d) Equation (18)
fx = f2 × A / q Equation (19)
fy = f2 × B / q (20)

(Dielectric constant calculator)
The dielectric constant calculator 176 calculates the dielectric constant of the dielectric 150 based on the capacitance when the common electrode 140 is in the initial position. The fact that the common electrode 140 is in the initial position is recognized by, for example, the fact that the detected capacitance has not changed for a predetermined period, that there is a notification from another input, or that it has just started.

(Elastic modulus calculator)
The elastic modulus calculation unit 177 calculates the elastic modulus from the calculated dielectric constant based on the predetermined relationship information 165 that represents the relationship between the dielectric constant and the elastic modulus of the dielectric 150. The relationship information 165 is a calculation formula representing the relationship between the dielectric constant and the elastic modulus in one example, and is a table representing the relationship between the dielectric constant and the elastic modulus in another example. The compressive force calculating unit 174 calculates the compressive force using the elastic modulus calculated by the elastic modulus calculating unit 177.

(Sensor control method)
FIG. 6 is a flowchart for explaining a sensor control method performed by the sensor 100 shown in FIG. Note that the order of steps is not limited to that shown in the figure as long as the calculation is possible.

  First, in step 181 shown in FIG. 6, the detection unit 171 (FIG. 5) detects capacitance (that is, C1, C2, C3, and C4). Next, in step 182 shown in FIG. 6, the compression displacement amount calculation unit 172 (FIG. 5) calculates the compression displacement amount d based on the equation (4). Next, in step 183 shown in FIG. 6, the shear displacement amount calculation unit 173 (FIG. 5) calculates the first shear displacement amount A based on the equation (9) and the second shear amount based on the equation (10). The displacement amount B is calculated, and the total shear displacement amount q is calculated based on the equation (11).

  Next, in step 184 shown in FIG. 6, the compression force calculation unit 174 (FIG. 5) calculates the compression force f1 based on the equation (15). Next, in step 185 shown in FIG. 6, the shear force calculation unit 175 (FIG. 5) calculates the overall shear force f2 based on the equation (18), and the first shear force fx based on the equation (19). And the second shearing force fy is calculated based on the equation (20).

(Calibration method)
FIG. 7 is a flowchart for explaining a calibration method performed by the sensor 100 shown in FIG.

  First, in step 186, the dielectric constant calculator 176 (FIG. 5) determines whether or not the common electrode 140 (FIG. 4) is in the initial position. The common electrode 140 (FIG. 4) is in the initial position because, for example, the detected capacitance does not change for a predetermined period, there is a notification from another input, or it is shortly after starting. recognize. If it is determined in step 186 that the common electrode 140 (FIG. 4) is not in the initial position, the calibration method ends. If it is determined in step 186 that the common electrode 140 (FIG. 4) is at the initial position, the process proceeds to step 187.

  In step 187, the dielectric constant calculation unit 176 (FIG. 5) calculates the equation (C1, C2, C3, and C4) based on the electrostatic capacitance when the common electrode 140 (FIG. 4) is in the initial position (ie, 2), the dielectric constant of the dielectric 150 (FIG. 3) is calculated. Next, in step 188, the elastic modulus calculator 177 (FIG. 5) calculates the elastic modulus based on the relationship information 165 (FIG. 5) and the calculated dielectric constant. After the elastic modulus is calculated, the compressive force calculating unit 174 (FIG. 5) calculates the compressive force using the calculated elastic modulus.

  As described above, when the displacement amount A of the common electrode 140 in the x1 direction increases, the opposing area between the first independent electrode 130-1 and the common electrode 140 becomes equal to the opposing area between the third independent electrode 130-3 and the common electrode 140. The area SL including the area monotonously increases, and the area SR obtained by adding the facing area of the fourth independent electrode 130-4 and the common electrode 140 to the facing area of the second independent electrode 130-2 and the common electrode 140 is as follows: Monotonically decreases at the same rate of change as SL. Similar to Equation (3), when d2 is constant, the capacitance CL is proportional to SL, and the capacitance CR is proportional to SR.

  Therefore, since A and CL correspond one-to-one and A and CR correspond one-to-one, if d2 is known, A is uniquely calculated from CL and CR. The same applies to the x2, y1, and y2 directions.

(Summary)
The sensor 100 according to this embodiment includes a plurality of independent electrodes 130, a common electrode 140 that is supported so as to be displaceable in the compression direction and the shearing direction orthogonal to the compression direction from the initial position with respect to the plurality of independent electrodes 130, A dielectric 150 positioned between the electrode 140 and the plurality of independent electrodes 130; a detection unit 171 that detects a capacitance between each of the common electrode 140 and the plurality of independent electrodes 130; Based on the sum of the capacities, a compression displacement amount calculation unit 172 that calculates a relative compression displacement amount between the common electrode 140 and the plurality of independent electrodes 130 in the compression direction, and based on the detected capacitance, the shear direction A shear displacement amount calculation unit 173 that calculates a relative shear displacement amount between the common electrode 140 and the plurality of independent electrodes 130 in each of which the plurality of independent electrodes 130 are orthogonal to the compression direction. With the independent facing surfaces 131 spreading, all the independent facing surfaces 131 spread along the same plane, the common electrode 140 has the common facing surface 141 extending perpendicular to the compression direction, and the common electrode 140 is in the initial position. In some cases, each independent facing surface 131 includes a region facing the common facing surface 141 in the compression direction and a region not facing the common facing surface 141. In at least a part of a range in which the common electrode 140 can move, Among them, the total area facing the plurality of independent facing surfaces 131 is constant.

  According to the present embodiment, the capacitance of the plurality of common independent electrodes 130 is used in the calculation of the compression displacement amount and the shear displacement amount. Therefore, separate electrodes are used for the calculation of the compression displacement amount and the shear displacement amount. It is possible to accurately detect the amount of compressive displacement and the amount of shear displacement with a simple structure as compared with the conventional technology to be prepared. In addition, since it is not necessary to overlap the dielectric 150 for detecting the amount of compressive displacement and the dielectric 150 for detecting the amount of shear displacement, it is possible to accurately distinguish between the amount of compressive displacement and the amount of shear displacement.

  In the present embodiment, the first section 103-1, the second section 103-2, and the third section 103- divided by the first virtual center line 101 and the second virtual center line 102 that intersects the first virtual center line 101. 3 and the fourth section 103-4, one independent electrode 130 is located, the first virtual center line 101 is parallel to the first shear direction orthogonal to the compression direction, and the second virtual center line 102 is The first independent electrode 130-1 that is the independent electrode 130 that is parallel to the second shearing direction orthogonal to the compression direction and the first shearing direction and is located in the first section 103-1, and the second section 103-2. The third independent electrode 130-3, which is the independent electrode 130 located in the third section 103-3, and the second independent electrode 130-2, which is the independent electrode 130 located in the third section 103-3, are arranged in the first shear direction. Independent electrode 130 located at 103-4 The fourth independent electrode 130-4 is arranged in the first shear direction, the first independent electrode 130-1 and the third independent electrode 130-3 are arranged in the second shear direction, and the second independent electrode 130-2 and the second independent electrode 130-2 are arranged in the first shear direction. 4 independent electrodes 130-4 are arranged in the second shear direction, and the detection unit 171 detects a first capacitance that is a capacitance between the first independent electrode 130-1 and the common electrode 140, The detection unit 171 detects a second capacitance that is a capacitance between the second independent electrode 130-2 and the common electrode 140, and the detection unit 171 detects the third independent electrode 130-3 and the common electrode 140. A third capacitance that is a capacitance between the fourth independent electrode 130-4 and the common electrode 140, and a detection unit 171 detects a fourth capacitance that is a capacitance between the fourth independent electrode 130-4 and the common electrode 140. The compression displacement amount calculation unit 172 includes a first capacitance, a second capacitance, a third capacitance, and a fourth capacitance. Based on the sum, the compression displacement amount is calculated, and the shear displacement amount calculation unit 173 calculates the sum of the first capacitance and the third capacitance, and the sum of the second capacitance and the fourth capacitance. Based on the above, the first shear displacement amount that is the shear displacement amount in the first shear direction is calculated, and the shear displacement amount calculation unit 173 calculates the sum of the first capacitance and the second capacitance, and the third Based on the sum of the capacitance and the fourth capacitance, a second shear displacement amount that is a shear displacement amount in the second shear direction is calculated.

  According to this embodiment, the displacement amount in multiple directions, that is, the compression displacement amount, the first shear displacement amount in the first shear direction, and the second shear displacement in the second shear direction has a simple structure as compared with the prior art. The amount can be accurately detected.

  In the present embodiment, the independent facing surface 131 of the first independent electrode 130-1 and the independent facing surface 131 of the third independent electrode 130-3 are axisymmetric with respect to the first virtual center line 101, and are second independent. The independent opposing surface 131 of the electrode 130-2 and the independent opposing surface 131 of the fourth independent electrode 130-4 are axisymmetric with respect to the first virtual center line 101, and the independent opposing surface of the first independent electrode 130-1 131 and the independent opposing surface 131 of the second independent electrode 130-2 are axisymmetric with respect to the second virtual center line 102, and the independent opposing surface 131 of the third independent electrode 130-3 and the fourth independent electrode 130- The four independent facing surfaces 131 are axisymmetric with respect to the second virtual center line 102.

  According to the present embodiment, since the independent facing surfaces 131 of the plurality of independent electrodes 130 have symmetry, manufacturing is easier than in the asymmetric case, and the amount of displacement can be easily calculated.

  In the present embodiment, each independent facing surface 131 is a rectangle having two sides parallel to the first shearing direction and two sides parallel to the second shearing direction, and the common facing surface 141 is parallel to the first shearing direction. And a rectangle having two sides parallel to the second shear direction.

  According to the present embodiment, since the plurality of independent electrodes 130 are rectangular, manufacturing is easier than in a complicated shape, and calculation of capacitance is facilitated.

  In the present embodiment, the dielectric 150 is an elastic body that fills the space between the plurality of independent electrodes 130 and the common electrode 140 in the compression direction, and the common electrode 140 is initially applied to the plurality of independent electrodes 130 by the dielectric 150. It is supported so as to be relatively displaceable from the position in the compression direction and the shearing direction.

  According to the present embodiment, the configuration is simple as compared to the case where the common electrode 140 is supported by a material different from the dielectric 150. Further, since the dielectric 150 is an elastic body, the common electrode 140 can be automatically returned to the original position when the force is released.

  The sensor 100 according to the present embodiment includes a compression force calculation unit 174 that calculates a compression force applied from the common electrode 140 to the dielectric 150 in the compression direction based on the amount of compressive displacement and the material characteristics of the dielectric 150. Based on the compression displacement amount, the first shear displacement amount, the second shear displacement amount, and the material properties of the dielectric 150, the shear that calculates the shear force applied in the shear direction from the common electrode 140 to the dielectric 150 is calculated. A force calculation unit 175.

  According to the present embodiment, since the electrostatic capacity of a plurality of common independent electrodes 130 is used in the calculation of the compression force and the shearing force, the conventional technique in which separate electrodes are prepared for the calculation of the compression force and the shearing force. It is possible to accurately detect the compressive force and the shearing force with a simple structure. Further, unlike the prior art, it is not necessary to overlap the dielectric 150 for detecting the compressive force and the dielectric 150 for detecting the shearing force, so that the compressive force and the shearing force can be accurately distinguished.

  The sensor 100 according to the present embodiment includes a dielectric constant calculator 176 that calculates the dielectric constant of the dielectric 150 based on the capacitance when the common electrode 140 is in the initial position, and the dielectric constant and the elastic modulus of the dielectric 150. An elastic modulus calculation unit 177 that calculates an elastic modulus from the calculated dielectric constant based on the predetermined relationship information 165 that represents the relationship between The compression force calculation unit 174 calculates the compression force using the calculated elastic modulus.

  According to the present embodiment, the compressive force can be accurately detected in consideration of the change in the elastic modulus of the dielectric 150 due to temperature or the like.

  The sensor 100 of this embodiment includes a stopper 111 that limits the movement range of the common electrode 140 with respect to the plurality of independent electrodes 130, and the dielectric 150 is elastically deformable within the movement range.

  According to the present embodiment, plastic deformation of the dielectric 150 can be prevented and accurate detection can be maintained.

  The sensor 100 according to the present embodiment includes a first substrate 110, a second substrate 120, a plurality of first wires 112 connected to each of the plurality of independent electrodes 130, and a second wire 121 connected to the common electrode 140. And at least a part of each of the plurality of first wirings 112 and the plurality of independent electrodes 130 are fixed to the first substrate 110, and at least a part of the second wirings 121 and the common electrode 140 are , Fixed to the second substrate 120.

  According to this embodiment, since the plurality of first wirings 112 and the plurality of independent electrodes 130 are fixed to the first substrate 110, it is easy to prevent disconnection. In addition, since the second wiring 121 and the common electrode 140 are fixed to the second substrate 120, it is easy to prevent disconnection.

  The sensor 100 according to the present embodiment is connected to each of the stopper 111 that limits the movement range of the common electrode 140 with respect to the plurality of independent electrodes 130, the first substrate 110 on which the stopper 111 is fixed, and the plurality of independent electrodes 130. A plurality of first wirings 112, and a second wiring 121 extending between the first substrate 110 and the common electrode 140. The dielectric 150 is elastically deformable within a moving range, and the plurality of first wirings At least a part of each of the wirings 112 is fixed to the first substrate 110, and at least a part of the second wiring 121 is fixed to the stopper 111.

  According to the present embodiment, since the first wiring 112 and the second wiring 121 are fixed, it is easy to prevent disconnection.

(Second Embodiment)
FIG. 8 is a plan view of the common electrode 240, the four independent electrodes 230, and the dielectric 250 according to this embodiment.

  Each independent facing surface 231 is generally fan-shaped having a common virtual center point 204. The independent facing surface 231 generally has a central angle of 90 degrees defined by the x direction and the y direction. That is, the four independent facing surfaces 231 are approximately one circle divided into four equal parts. The common facing surface 241 is circular. When the common electrode 240 is in the initial position, the center point of the common facing surface 241 overlaps the virtual center point 204 in the z direction.

  The dielectric 250 is an elastic body that fills a space between the common electrode 240 and a region of the four independent electrodes 230 facing the common electrode 240 in the z direction. The dielectric 250 is generally a cylinder having a central axis extending in the z direction. When viewed from the z-direction, the dielectric 250 generally extends slightly outward from the common electrode 240, but is smaller than the overall outline of the four independent electrodes 230.

  The calculation method of the capacitances (CL, CR) on both sides of the second virtual center line 202 is different from the equations (5) and (6). However, each area where the common facing surface 241 and the independent facing surface 231 face each other on both sides of the first virtual center line 201 is mathematically a function of the amount of displacement in the x direction. Conversely, the amount of displacement is calculated from the area. Is done. Therefore, if the capacitance is known, the area can be known, and as a result, the displacement amount is calculated. The same applies to the amount of displacement in the y direction. If the amount of displacement in the x direction and the y direction is known, the compression force and the shear force can be calculated as in the first embodiment (FIG. 4).

  In another example, as in the first embodiment, a cylindrical stopper that surrounds the four independent electrodes 230 along the outer shape of the four independent electrodes 230 limits the movement range of the common electrode 240.

(Summary)
In the present embodiment, each independent facing surface 231 has a fan shape with a common virtual center point 204, the common facing surface 241 has a circular shape, and the common electrode 240 is in the initial position. The center point of the facing surface 241 overlaps the virtual center point 204.

  According to the present embodiment, since the plurality of independent electrodes 230 have a fan shape, manufacturing is easier than in a complicated shape, and calculation of capacitance is facilitated. Further, when the common electrode 240 is displaced from the initial position, the maximum displaceable amount can be made the same in any direction.

(Third embodiment)
FIG. 9 is a plan view of the common electrode 340, the four independent electrodes 330, and the dielectric 350 according to this embodiment. The description of the shape of the common electrode 340 is based on the positional relationship when in the initial position.

  The common facing surface 341 of the common electrode 340 includes a first curved edge 392-1 located in the first section 303-1, a second curved edge 392-2 located in the second section 303-2, and a third. A third curved edge 392-3 located in the section 303-3 and a fourth curved edge 392-4 located in the fourth section 303-4 (hereinafter, referred to as a curved edge 392 without distinction). There is). The curved edge 392 has a fan shape with a central angle of 90 degrees defined between the x direction and the y direction. The four curved edges 392 are generally equal to one circle divided into four equal parts. The curved edge 392 is convex outward in a plane orthogonal to the compression direction.

  The common facing surface 341 is parallel to the x direction and extends from the first section 303-1 into the second section 303-2, and is parallel to the y direction from the first section 303-1. A second edge 391-2 extending into the third section 303-3, a third edge 391-3 extending in parallel to the y direction from the second section 303-2 into the fourth section 303-4, and x A fourth edge 391-4 extending parallel to the direction and extending from the third section 303-3 into the fourth section 303-4.

  In the first section 303-1, the first curved edge 392-1 connects one end of the first edge 391-1 and one end of the second edge 391-2. In the second section 303-2, the second curved edge portion 392-2 connects the other end of the first edge portion 391-1 and one end of the third edge portion 391-3. In the third section 303-3, the third curved edge 392-3 connects the other end of the second edge 391-2 and one end of the fourth edge 391-4. In the fourth section 303-4, the fourth curved edge 392-4 connects the other end of the third edge 391-3 and the other end of the fourth edge 391-4.

  A region in the first section 303-1 of the common facing surface 341 has a shape that continuously extends from the first edge 391-1 and the curved edge 392 to the third section 303-3 in the second shear direction. . A region in the first section 303-1 of the common facing surface 341 has a shape that continuously extends from the second edge 391-2 and the curved edge 392 to the second section 303-2 in the first shear direction. . The entire common facing surface 341 has a shape that is line-symmetric with respect to the first virtual center line 301 and a shape that is line-symmetric with respect to the second virtual center line 302. That is, the common facing surface 341 as a whole has a shape with rounded rectangular corners.

  The first independent facing surface 331-1 of the first independent electrode 330-1 located in the first section 303-1 includes a first outer edge portion 393 parallel to the first edge portion 391-1 and a second edge portion 391-. 2, a second outer edge 394 parallel to 2, a curved outer edge 395, a third outer edge 396 parallel to the x direction, and a fourth outer edge 397 parallel to the y direction. The curved outer edge portion 395 connects one end on the x1 side of the first outer edge portion 393 and one end on the y2 side of the second outer edge portion 394. The curved outer edge 395 has a fan shape having a central angle of 90 degrees defined between the x direction and the y direction. The curved outer edge 395 is convex outward in a plane orthogonal to the compression direction.

  One end of the third outer edge portion 396 on the x1 side is connected to one end of the second outer edge portion 394 on the y1 side. One end of the fourth outer edge portion 397 on the y2 side is connected to one end of the first outer edge portion 393 on the x2 side. One end of the third outer edge portion 396 on the x2 side is connected to one end of the fourth outer edge portion 397 on the y1 side. The intersection of the third outer edge 396 and the fourth outer edge 397 is located near the intersection of the first virtual center line 301 and the second virtual center line 302.

  The first independent facing surface 331-1 has a shape that continuously extends from the first outer edge portion 393 and the curved outer edge portion 395 to the third outer edge portion 396 toward the third section 303-3 in the y direction. The first independent facing surface 331-1 has a shape that continuously extends from the second outer edge portion 394 and the curved outer edge portion 395 toward the fourth outer edge portion 397 toward the second section 303-2 in the x direction. As a whole, the first independent electrode 330-1 has a rounded shape at a corner farthest from the intersection of the first virtual center line 301 and the second virtual center line 302 of the rectangle.

  The external shape of the four independent opposing surfaces 331 as a whole has a shape in which rectangular corners are rounded. Further, the four independent facing surfaces 331 are separated by a cross-shaped thin insulating region along the first virtual center line 301 and the second virtual center line 302. When the common electrode 340 is at the initial position, the fan-shaped virtual center point of the curved edge portion 392 overlaps the fan-shaped virtual center point of the curved outer edge portion 395 at the point 305 in the z direction. When viewed from the z direction, the outer shape of the common facing surface 341 is smaller than the entire outer shape of the four independent facing surfaces 331.

  When the common electrode 340 is in the initial position, the separation distance L1 between the first outer edge 393 and the first edge 391-1 in the y direction is equal to the second outer edge 394 and the second edge 391-2 in the x direction. Is the same as the separation distance L2. When the common electrode 340 is in the initial position, the difference L3 between the radius of the curved outer edge portion 395 and the radius of the curved edge portion 392 is the separation distance L1 between the first outer edge portion 393 and the first edge portion 391-1 in the y direction. Is the same.

  The first independent facing surface 331-1 and the third independent facing surface 331-3 are axisymmetric with respect to the first virtual center line 301. The second independent facing surface 331-2 and the fourth independent facing surface 331-4 are line symmetric with respect to the first virtual center line 301. The first independent facing surface 331-1 and the second independent facing surface 331-2 are line symmetric with respect to the second virtual center line 302. The third independent facing surface 331-3 and the fourth independent facing surface 331-4 are line symmetric with respect to the second virtual center line 302.

  The dielectric 350 is an elastic body that fills the space between the common electrode 340 and a region facing the common electrode 340 among the four independent electrodes 330 in the z direction. The dielectric 350 is generally a columnar body extending in the z direction, and a cross section parallel to the xy plane is substantially similar to the common facing surface 341. When viewed from the z direction, the dielectric 350 generally extends slightly outward from the common electrode 340, but is smaller than the overall shape of the four independent electrodes 330.

  The calculation method of the capacitances (CL, CR) on both sides of the second virtual center line 302 is different from the equations (5) and (6). However, each area where the common facing surface 341 and the independent facing surface 331 face each other on both sides of the first virtual center line 301 is a function of the amount of displacement in the x direction. Conversely, the amount of displacement is calculated from the area. Is done. Therefore, if the capacitance is known, the area can be known, and as a result, the displacement amount is calculated. The same applies to the amount of displacement in the y direction. If the amount of displacement in the x direction and the y direction is known, the compression force and the shear force can be calculated as in the first embodiment (FIG. 4).

(Summary)
In the present embodiment, the common facing surface 341 is parallel to the first shear direction and the first edge 391-1 extending from the first section 303-1 into the second section 303-2 and parallel to the second shear direction. The second edge 391-2 extending from the first section 303-1 into the third section 303-3 and the curved edge 392, and when the common electrode 340 is in the initial position, the curved edge 392 is The curved edge 392 connects one end of the first edge 391-1 and one end of the second edge 391-2, and the curved edge 392 is a first shear. The curved edge 392 is convex outward in a plane orthogonal to the compression direction, and has a central shape of 90 degrees defined between the direction and the second shear direction. When 340 is in the initial position, the region in the first section 303-1 in the common facing surface 341 When the common electrode 340 is in the initial position, it has a shape that continuously extends from the first edge portion 391-1 and the curved edge portion 392 to the third section 303-3 in the second shear direction. Of these, the region in the first section 303-1 has a shape that continuously extends from the second edge 391-2 and the curved edge 392 to the second section 303-2 in the first shear direction, and the first independent electrode The independent facing surface 331 of 330-1 includes a first outer edge 393 parallel to the first edge 391-1, a second outer edge 394 parallel to the second edge 391-2, and a curved outer edge 395. In other words, the curved outer edge portion 395 connects one end of the first outer edge portion 393 and one end of the second outer edge portion 394, and the curved outer edge portion 395 is defined between the first shearing direction and the second shearing direction 90. It has a fan shape with a central angle of degrees, and the curved outer edge 395 is straight in the compression direction. The independent facing surface 331 of the first independent electrode 330-1 is convex in the second shear direction from the first outer edge portion 393 and the curved outer edge portion 395 in the second shearing direction 303-3. The independent facing surface 331 of the first independent electrode 330-1 is directed from the second outer edge portion 394 and the curved outer edge portion 395 toward the second section 303-2 in the first shear direction. When the common electrode 340 is in the initial position, the fan-shaped virtual center point of the curved edge 392 overlaps the fan-shaped virtual center point of the curved outer edge 395 in the compression direction. When the electrode 340 is in the initial position, the separation distance between the first outer edge portion 393 and the first edge portion 391-1 in the second shearing direction is the second outer edge portion 394 and the second edge portion 391-in the first shearing direction. Distance from 2 When the common electrode 340 is in the initial position, the difference between the radius of the curved outer edge 395 and the radius of the curved edge 392 is the first outer edge 393 and the first edge 391- in the second shear direction. 1 is the same as the distance from 1.

  According to the present embodiment, when the common electrode 340 is displaced from the initial position, the maximum displaceable amount can be made the same in any direction.

(Fourth embodiment)
FIG. 10 is a plan view of the common electrode 440, the three independent electrodes 430, and the dielectric 450 of the present embodiment. Unlike the first embodiment (FIG. 4), there are three independent electrodes 430, which are positioned rotationally symmetrical. The three independent electrodes 430 include a first independent electrode 430-1, a second independent electrode 430-2, and a third independent electrode 430-3.

  The first virtual line 406-1, the second virtual line 406-2, and the third virtual line 406-3 are defined counterclockwise at 120 degree intervals. The first virtual line 406-1 is parallel to the y direction. The first section 403-1 is located between the second virtual line 406-2 and the third virtual line 406-3, and the second section 403-1 is located between the third virtual line 406-3 and the first virtual line 406-1. The section 403-2 is located, and the third section 403-3 is located between the first virtual line 406-1 and the second virtual line 406-2.

  The entire first independent electrode 430-1 is located in the first section 403-1. The first independent electrode 430-1 includes a first edge 498-1 parallel to the x direction, a second edge 498-2 extending in the y2 direction from one end on the x2 side of the first edge 498-1, A third edge 498-3 extending in the y2 direction from one end of the first edge 498-1 on the x1 side, a fourth edge 498-4 parallel to the second imaginary line 406-2, and a third imaginary line And a fifth edge 498-5 parallel to 406-3.

  The 2nd edge part 498-2 and the 3rd edge part 498-3 are the same length. The fourth edge 498-4 is connected to the y2 side end of the second edge 498-2 at one end. The fifth edge 498-5 is connected to the y2 side end of the third edge 498-3 at one end. The other end of the fourth edge 498-4 is connected to the other end of the fifth edge 498-5. The fourth edge 498-4 and the fifth edge 498-5 have the same length and define an internal angle of 120 degrees.

The second independent electrode 430-2 located in the second section 403-2 has a shape obtained by rotating the first independent electrode 430-1 by 120 degrees clockwise. The third independent electrode 430-3 located in the third section 403-3 has a shape obtained by rotating the first independent electrode 430-1 by 120 degrees counterclockwise.
The first independent electrode 430-1, the second independent electrode 430-2, and the third independent electrode 430-3 are positioned with their apexes forming an angle of 120 degrees close to each other.

  The shapes of the common electrode 440 and the dielectric 450 are the same as the shapes of the common electrode 140 and the dielectric 150 of the first embodiment (FIG. 4). When the common electrode 440 is in the initial position, the center of gravity of the common electrode 440 overlaps the intersection of the first virtual line 406-1, the second virtual line 406-2, and the third virtual line 406-3 in the z direction. When viewed from the z direction, the outer shapes of the common electrode 440 and the dielectric 450 do not come out of the outer shapes of the three independent electrodes 430.

(Summary)
According to the present embodiment, it is possible to detect the amount of displacement of the common electrode 440 in three shear directions orthogonal to the compression direction.

(Fifth embodiment)
FIG. 11 is a plan view of the common electrode 540, the four independent electrodes 530, and the auxiliary electrode 532 according to this embodiment. The shape of the common electrode 540 of this embodiment is the same as the shape of the common electrode 140 of the first embodiment (FIG. 4).

  Each independent electrode 530 of the present embodiment is cut out into a rectangle at an angle close to the intersection of the first virtual center line 101 and the second virtual center line 102 in the independent electrode 130 of the first embodiment (FIG. 4). It has a different shape. As shown in FIG. 11, the four independent electrodes 530 have two sides parallel to the x direction and two sides parallel to the y direction so as to overlap with the intersection of the first virtual center line 501 and the second virtual center line 502. A free area 534 surrounded by The area of the empty area 534 is smaller than the area of the common facing surface 541.

  The auxiliary electrode 532 is located in the empty area 534 so as to overlap the intersection of the first virtual center line 501 and the second virtual center line 502. The auxiliary electrode 532 is a thin-film flat metal that extends parallel to the xy plane. The auxiliary electrode 532 has an auxiliary facing surface 533 that extends in a direction perpendicular to the z direction and faces the z1 direction. The auxiliary facing surface 533 is a rectangle having two sides parallel to the x direction and two sides parallel to the y direction. The independent facing surface 531 and the auxiliary facing surface 533 extend along the same plane.

  When viewed from the z direction, the outer shape of the auxiliary facing surface 533 is smaller than the entire outer shape of the common facing surface 541. The area of the auxiliary facing surface 533 is smaller than the area of the common facing surface 541. The entire auxiliary facing surface 533 faces the common facing surface 541 in the z direction. In one example, the entire auxiliary facing surface 533 faces the common facing surface 541 in the z direction in at least a part of the movable range of the common electrode 540. In another example, the entire auxiliary facing surface 533 faces the common facing surface 541 in the z direction in the entire movable range of the common electrode 540.

  FIG. 12 is a block diagram showing the independent electrode 530, the common electrode 540, the auxiliary electrode 532, and the control device 560. Unlike the first embodiment, the detection circuit 561 further determines the auxiliary electrode from the amount of charge accumulated between the auxiliary electrode 532 and the common electrode 540 when a voltage is applied between the auxiliary electrode 532 and the common electrode 540. The electrostatic capacitance C5 between 532 and the common electrode 540 is detected. The compression displacement amount calculation unit 572 calculates the compression displacement amount based on C5 in addition to the compression displacement amount calculated in the first embodiment or instead of the compression displacement amount calculated in the first embodiment. .

  The auxiliary electrode 532 is bisected in the y direction by the first virtual center line 501 and bisected in the x direction by the second virtual center line 502. Further, the distance between the auxiliary electrode 532 and the independent electrode 530 is negligible. Compared to the CL and CR of the first embodiment, the CL and CR of the present embodiment are respectively C5 / 2 smaller. However, if the difference is taken as in equation (8), C5 / 2 is canceled out, so A is obtained from the first and second terms of equation (8) without using C5. The same applies to B. In the present embodiment, C5 can also be used for calculating the shear displacement amount by rewriting Equation (9) and Equation (10) by using the fact that the right side of Equation (7) represents CAB + C5. .

(Summary)
The sensor of the present embodiment includes an auxiliary electrode 532, the auxiliary electrode 532 has an auxiliary facing surface 533 that extends in a direction perpendicular to the compression direction, and the area of the auxiliary facing surface 533 is smaller than the area of the common facing surface 541. The entire facing surface 533 faces the common facing surface 541 in the compression direction.

  According to this embodiment, since the entire auxiliary facing surface 533 faces the common facing surface 541 in the compression direction, the capacitance between the auxiliary electrode 532 and the common electrode 540 is constant regardless of the displacement in the shearing direction. Thus, the displacement in the compression direction can be detected stably.

  The present invention is not limited to the embodiment described above. That is, those skilled in the art may make various modifications, combinations, subcombinations, and alternatives regarding the components of the above-described embodiments within the technical scope of the present invention or an equivalent scope thereof.

  The present invention can be applied to various sensors that detect displacement by capacitance.

100 ... sensor, 101 ... first virtual center line, 102 ... second virtual center line,
103 ... Section (103-1 ... 1st section-103-4 ... 4th section), 110 ... 1st board | substrate,
111 ... stopper, 112 ... first wiring, 120 ... second substrate, 121 ... second wiring,
130 ... Independent electrode (130-1 ... 1st independent electrode-130-4 ... 4th independent electrode),
131: Independently facing surface (131-1, ... 1st independently facing surface to 131-4 ... 4th independently facing surface),
140 ... Common electrode, 141 ... Common facing surface, 150 ... Dielectric, 160 ... Control device,
161... Detection circuit, 162... Storage device, 163.
164 ... Control program, 165 ... Related information, 171 ... Detection part,
172 ... Compression displacement calculation unit, 173 ... Shear displacement calculation unit, 174 ... Compression force calculation unit,
175 ... Shear force calculation unit, 176 ... Dielectric constant calculation unit, 177 ... Elastic modulus calculation unit,
204 ... Virtual center point, 305 ... Point, 391-1 ... First edge, 391-2 ... Second edge,
391-3 ... third edge, 391-4 ... fourth edge,
392 ... curved edge (392-1 ... first curved edge to 392-4 ... fourth curved edge),
393 ... first outer edge part, 394 ... second outer edge part, 395 ... curved outer edge part,
396 ... Third outer edge, 397 ... Fourth outer edge,
403-1 ... 1st division, 403-2 ... 2nd division, 403-3 ... 3rd division,
406-1 ... 1st virtual line, 406-2 ... 2nd virtual line, 406-3 ... 3rd virtual line,
430 ... independent electrode (430-1 ... first independent electrode to 430-3 ... third independent electrode),
431 ... independent facing surface (431-1 ... first independent facing surface to 431-3 ... third independent facing surface),
498-1 ... 1st edge part, 498-2 ... 2nd edge part, 498-3 ... 3rd edge part,
498-4 ... 4th edge part, 498-5 ... 5th edge part,
532 ... auxiliary electrode, 533 ... auxiliary facing surface

Claims (15)

A plurality of independent electrodes;
A common electrode supported so as to be displaceable in a compression direction and a shear direction perpendicular to the compression direction from an initial position with respect to the plurality of independent electrodes;
A dielectric positioned between the common electrode and the plurality of independent electrodes;
A detection unit for detecting a capacitance between the common electrode and each of the plurality of independent electrodes;
A compression displacement amount calculation unit that calculates a relative compression displacement amount between the common electrode and the plurality of independent electrodes in the compression direction based on the detected sum of the capacitances;
A shear displacement amount calculation unit that calculates a relative shear displacement amount between the common electrode and the plurality of independent electrodes in the shear direction based on the detected capacitance;
With
Each of the plurality of independent electrodes has an independent facing surface extending perpendicular to the compression direction,
All the independent facing surfaces extend along the same plane;
The common electrode has a common facing surface extending perpendicular to the compression direction;
When the common electrode is in the initial position, each of the independent facing surfaces includes a region facing the common facing surface in the compression direction and a region not facing the region.
In at least a part of the movable range of the common electrode, the total area facing the plurality of independent facing surfaces among the common facing surfaces is constant.
Sensor. One independent electrode is located in each of the first section, the second section, the third section, and the fourth section divided by the first virtual center line and the second virtual center line that intersects the first virtual center line. And
The first virtual center line is parallel to a first shear direction orthogonal to the compression direction;
The second virtual center line is parallel to a second shear direction perpendicular to the compression direction and the first shear direction;
A first independent electrode that is the independent electrode located in the first section and a second independent electrode that is the independent electrode located in the second section are aligned in the first shear direction,
A third independent electrode that is the independent electrode located in the third compartment and a fourth independent electrode that is the independent electrode located in the fourth compartment are aligned in the first shear direction,
The first independent electrode and the third independent electrode are arranged in the second shear direction,
The second independent electrode and the fourth independent electrode are arranged in the second shear direction;
The detection unit detects a first capacitance which is the capacitance between the first independent electrode and the common electrode;
The detection unit detects a second capacitance which is the capacitance between the second independent electrode and the common electrode;
The detection unit detects a third capacitance which is the capacitance between the third independent electrode and the common electrode;
The detection unit detects a fourth capacitance which is the capacitance between the fourth independent electrode and the common electrode;
The compression displacement amount calculation unit calculates the compression displacement amount based on a sum of the first capacitance, the second capacitance, the third capacitance, and the fourth capacitance;
The shear displacement amount calculation unit is configured to calculate the first capacitance based on a sum of the first capacitance and the third capacitance and a sum of the second capacitance and the fourth capacitance. Calculating a first shear displacement amount that is the shear displacement amount in the shear direction;
The shear displacement amount calculation unit is configured to calculate the second capacitance based on a sum of the first capacitance and the second capacitance and a sum of the third capacitance and the fourth capacitance. Calculating a second shear displacement amount that is the shear displacement amount in the shear direction;
The sensor according to claim 1. The independent opposing surface of the first independent electrode and the independent opposing surface of the third independent electrode are axisymmetric with respect to the first virtual center line;
The independent opposing surface of the second independent electrode and the independent opposing surface of the fourth independent electrode are axisymmetric with respect to the first virtual center line;
The independent opposing surface of the first independent electrode and the independent opposing surface of the second independent electrode are axisymmetric with respect to the second virtual center line;
The independent opposing surface of the third independent electrode and the independent opposing surface of the fourth independent electrode are axisymmetric with respect to the second virtual center line;
The sensor according to claim 2. Each independently facing surface is a rectangle having two sides parallel to the first shear direction and two sides parallel to the second shear direction;
The common facing surface is a rectangle having two sides parallel to the first shear direction and two sides parallel to the second shear direction;
The sensor according to claim 3. Each of the independent facing surfaces has a fan shape having a common virtual center point,
The common facing surface is circular;
When the common electrode is at the initial position, a center point of the common facing surface overlaps the virtual center point in the compression direction.
The sensor according to claim 3. The common facing surface is parallel to the first shear direction and extends from the first section into the second section, and is parallel to the second shear direction and from the first section to the third section. Having a second edge extending inward and a curved edge;
When the common electrode is in the initial position, the curved edge is located in the first compartment;
The curved edge connects one end of the first edge and one end of the second edge;
The curved edge has a fan shape having a central angle of 90 degrees defined between the first shear direction and the second shear direction;
The curved edge is convex outward in a plane perpendicular to the compression direction;
When the common electrode is in the initial position, a region in the first section of the common facing surface continues from the first edge and the curved edge to the third section in the second shear direction. And has a shape that spreads,
When the common electrode is in the initial position, a region in the first section of the common facing surface is continuous from the second edge and the curved edge to the second section in the first shear direction. And has a shape that spreads,
The independent facing surface of the first independent electrode has a first outer edge parallel to the first edge, a second outer edge parallel to the second edge, and a curved outer edge;
The curved outer edge connects one end of the first outer edge and one end of the second outer edge;
The curved outer edge has a fan shape having a central angle of 90 degrees defined between the first shear direction and the second shear direction;
The curved outer edge is convex outward in a plane perpendicular to the compression direction;
The independent facing surface of the first independent electrode has a shape that continuously extends from the first outer edge portion and the curved outer edge portion toward the third section in the second shear direction,
The independent facing surface of the first independent electrode has a shape that continuously extends from the second outer edge portion and the curved outer edge portion toward the second section in the first shear direction,
When the common electrode is in the initial position, in the compression direction, the fan-shaped virtual center point of the curved edge overlaps the fan-shaped virtual center point of the curved outer edge;
When the common electrode is in the initial position, a separation distance between the first outer edge portion and the first edge portion in the second shear direction is equal to the second outer edge portion and the second edge in the first shear direction. It is the same as the distance from the part,
When the common electrode is in the initial position, the difference between the radius of the curved outer edge portion and the radius of the curved edge portion is a separation distance between the first outer edge portion and the first edge portion in the second shear direction. Is the same as
The sensor according to claim 3. The dielectric is an elastic body that fills the compression direction between the plurality of independent electrodes and the common electrode,
The common electrode is supported by the dielectric so as to be relatively displaceable in the compression direction and the shear direction from the initial position with respect to the plurality of independent electrodes.
The sensor as described in any one of Claims 1 thru | or 6. A compression force calculation unit that calculates a compression force applied in the compression direction from the common electrode to the dielectric based on the compression displacement amount and material characteristics of the dielectric;
A shear force applied from the common electrode to the dielectric in the shear direction based on the compression displacement, the first shear displacement, the second shear displacement, and the material properties of the dielectric. A shear force calculation unit for calculating
The sensor according to claim 7, comprising: A dielectric constant calculator that calculates a dielectric constant of the dielectric based on the capacitance when the common electrode is in the initial position;
An elastic modulus calculator that calculates the elastic modulus from the calculated dielectric constant based on pre-defined relationship information that represents the relationship between the dielectric constant and the elastic modulus of the dielectric;
With
The material properties used to calculate the compression force include the elastic modulus;
The compression force calculating unit calculates the compression force using the calculated elastic modulus;
The sensor according to claim 8. Comprising a stopper for limiting a movement range of the common electrode with respect to the plurality of independent electrodes;
The dielectric is elastically deformable within the moving range;
The sensor as described in any one of Claim 7 thru | or 9. A first substrate;
A second substrate;
A plurality of first wirings connected to each of the plurality of independent electrodes;
A second wiring connected to the common electrode;
With
At least a part of each of the plurality of first wirings and the plurality of independent electrodes are fixed to the first substrate;
At least a part of the second wiring and the common electrode are fixed to the second substrate;
The sensor according to any one of claims 1 to 10. A stopper for limiting a movement range of the common electrode with respect to the plurality of independent electrodes;
A first substrate on which the stopper is fixed;
A plurality of first wirings connected to each of the plurality of independent electrodes;
A second wiring extending between the first substrate and the common electrode;
With
The dielectric is elastically deformable within the moving range;
At least a part of each of the plurality of first wirings is fixed to the first substrate;
At least a part of the second wiring is fixed to the stopper;
The sensor as described in any one of Claim 7 thru | or 9. With an auxiliary electrode,
The auxiliary electrode has an auxiliary facing surface extending perpendicular to the compression direction,
An area of the auxiliary facing surface is smaller than an area of the common facing surface;
The entire auxiliary facing surface faces the common facing surface in the compression direction.
The sensor according to any one of claims 1 to 12. A sensor control method executed by a sensor,
The sensor is
The plurality of independent electrodes;
A common electrode supported so as to be displaceable in a compression direction and a shear direction perpendicular to the compression direction from an initial position with respect to the plurality of independent electrodes;
A dielectric positioned between the common electrode and the plurality of independent electrodes;
With
Each of the plurality of independent electrodes has an independent facing surface extending perpendicular to the compression direction,
All the independent facing surfaces extend along the same plane;
The common electrode has a common facing surface extending perpendicular to the compression direction;
When the common electrode is in the initial position, each of the independent facing surfaces includes a region facing the common facing surface in the compression direction and a region not facing the region.
In at least a part of the movable range of the common electrode, the total area facing the plurality of independent facing surfaces among the common facing surfaces is constant,
The sensor control method comprises:
The sensor detects a capacitance between the common electrode and each of the plurality of independent electrodes;
The sensor calculates a relative amount of compressive displacement between the common electrode and the plurality of independent electrodes in the compression direction based on the detected sum of the capacitances;
The sensor calculates a relative shear displacement amount between the common electrode and the plurality of independent electrodes in the shear direction based on the detected capacitance;
A sensor control method.   A control program for causing a computer to execute the sensor control method according to claim 14.

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