JP2016114494A - Electrostatic capacitance type sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrostatic capacitance type sensor with which it is possible to suppress noise from the periphery, and in which detection sensitivity is not susceptible to reduction.SOLUTION: An electrostatic capacitance type sensor 1 comprises: a sensor unit F having a surface-side electrode part FX, a reverse-side electrode part FY, and a dielectric layer 280 disposed between the surface-side electrode part FX and the reverse-side electrode part FY; an insulating spacer 251 disposed on a surface side and/or a reverse side of the sensor unit F and consisting of a plurality of insulating films 251d, 251e that are limited in a surface-reverse direction; a plurality of spot-shaped coupling part 295 for partially coupling the plurality of insulating films 251d, 251e with each other and disposed in a form of a dot pattern as seen from the surface side or reverse side; an earth electrode 241 disposed on the outside in the surface-reverse direction of the insulating spacer 251 and grounded to earth; and a control device 22F, electrically connected to the sensor unit F, for applying a voltage to the sensor unit F, and to which is transmitted an amount of electricity pertaining to an electrostatic capacitance of the sensor unit F.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a capacitive sensor used as, for example, a load sensor or a touch sensor.

  For example, as shown in Patent Document 1, a capacitive sensor includes a plurality of front-side electrodes, a plurality of back-side electrodes, and a dielectric layer. The plurality of front electrodes are arranged on the front side of the dielectric layer. The plurality of backside electrodes are disposed on the backside of the dielectric layer. When viewed from the front side or the back side, the plurality of front-side electrodes and the plurality of back-side electrodes are orthogonal to each other. A plurality of detection units are set in a portion where the plurality of front-side electrodes and the plurality of back-side electrodes overlap. When a load is applied to the detection unit from the front side, the dielectric layer is compressed in the front and back direction. For this reason, the interelectrode distance between the front side electrode and back side electrode which comprises the said detection part becomes small. Therefore, the capacitance of the detection unit is increased.

  As described above, when the capacitance type sensor is used, the load applied to the detection unit can be detected based on the change in the capacitance due to the change in the distance between the electrodes. Further, the load distribution in the surface direction of the capacitive sensor can be detected by detecting the load in the plurality of detection units. For this reason, an electrostatic capacitance type sensor is used, for example in bedclothes, such as a bed and a futon, when measuring the body pressure distribution of the person who is sleeping.

JP 2012-173100 A

  However, when the capacitive sensor is arranged on the bedding, the detection accuracy of the capacitive sensor is lowered due to the influence of noise from peripheral devices (for example, an electric blanket). In this regard, noise can be suppressed by arranging a ground electrode in the capacitive sensor. However, if the ground electrode is arranged, current may escape from the detection unit of the capacitive sensor to the ground via the ground electrode. That is, the current from the detection unit that is originally used for measuring the capacitance may escape to the ground. For this reason, the detection accuracy of a capacitance type sensor will fall. SUMMARY OF THE INVENTION An object of the present invention is to provide a capacitance type sensor that can suppress noise from the surroundings and that does not easily reduce detection accuracy.

  (1) In order to solve the above problems, a capacitive sensor of the present invention includes a front side electrode part, a back side electrode part disposed on the back side of the front side electrode part, the front side electrode part, and the back side electrode part. A dielectric layer disposed between the sensor unit, an insulating spacer made of a plurality of insulating films disposed on at least one of the front side and the back side of the sensor unit and stacked in the front-back direction, A plurality of spot-like connecting portions that are partially connected to each other and are arranged in a dot pattern when viewed from the front side or the back side, a ground electrode that is arranged on the outer side in the front and back direction of the insulating spacer, and is grounded; And a control device that is electrically connected to the sensor unit, applies a voltage to the sensor unit, and transmits an electric quantity related to the capacitance of the sensor unit.

  Hereinafter, in the insulating spacer, a portion where a plurality of insulating films are constrained to each other is appropriately referred to as a “constraint portion”. In the insulating spacer, a portion where the plurality of insulating films are not constrained to each other is appropriately referred to as a “non-constraining portion”.

  The capacitive sensor of the present invention includes a ground electrode. For this reason, noise from peripheral devices can be suppressed. An insulating spacer is interposed between the ground electrode and the sensor unit. For this reason, the detection accuracy of the capacitive sensor is unlikely to decrease.

  The insulating spacer is composed of a plurality of insulating films. For this reason, the thickness of the insulating spacer in the front and back direction (that is, the distance between the ground electrode and the sensor unit) can be easily adjusted by changing the number of laminated insulating films.

  In addition, the insulating spacer of the capacitive sensor of the present invention includes a restraining portion. For this reason, it can control that a plurality of insulating films shift mutually. In addition, the insulating spacer of the capacitive sensor of the present invention includes an unconstrained portion. For this reason, it can suppress that a deformation | transformation (for example, bending deformation) of a some insulating film restrains mutually. Moreover, it can accept | permit that the non-restraining part of arbitrary adjacent pairs of insulating films mutually slides.

  Further, when the insulating film is bent and deformed, the amount of expansion of the outer surface in the radius direction of curvature relative to the inner surface in the radius direction of curvature is smaller as the thickness of the insulating film in the front and back direction is smaller. For example, when a load is applied to the insulating film from the front side, the extension amount of the back surface with respect to the surface of the insulating film may be smaller as the thickness of the insulating film in the front-back direction is smaller. Thus, the smaller the front and back direction thickness of the insulating film is, the easier it is for the insulating film to bend.

  In this regard, according to the capacitance type sensor of the present invention, the insulating spacer is composed of a plurality of insulating films instead of a single insulating film. The insulating spacer includes a non-restraining portion. For this reason, compared with the insulating spacer which consists of a single insulating film (the thickness in the front and back direction of the insulating film is the sum of the thicknesses in the front and back directions of the plurality of insulating films), the insulation of the capacitive sensor of the present invention. The spacer is easy to bend.

  Thus, according to the capacitance type sensor of the present invention, the insulating spacer can be easily bent and deformed while sufficiently securing the thickness of the insulating spacer in the front and back direction (that is, the distance between the ground electrode and the sensor portion). can do.

  Moreover, in the restraint part, the some insulating film is restrained mutually. For this reason, a restraint part is harder to bend than a non-restraint part. In other words, the restraint portion is less flexible (for example, apparent bending rigidity) than the non-restraint portion. Therefore, the detection accuracy is likely to vary between the portion corresponding to the restraining portion and the portion corresponding to the non-restraining portion.

  In addition, the plurality of insulating films are in close contact with each other at the restraining portion. For this reason, the thickness of the insulating spacer in the front-back direction tends to be small. On the other hand, the plurality of insulating films are independent from each other in the unconstrained portion. For this reason, each insulating film is easily deformed independently. Accordingly, the thickness of the insulating spacer in the front and back direction tends to increase. Also in this respect, the detection accuracy is likely to vary between the portion corresponding to the restraining portion and the portion corresponding to the non-restraining portion.

  In this regard, the capacitive sensor of the present invention includes a plurality of spot-like connecting portions. The plurality of spot-like connecting portions are arranged in a dot pattern when viewed from the front side or the back side of the insulating spacer. The restraint portions are distributed and arranged over the entire surface of the insulating spacer. For this reason, the constraining portion (a portion having low flexibility and a portion having a small thickness in the front and back direction) is difficult to continue over the entire surface of the insulating spacer. Moreover, it is easy to improve the flatness of the insulating spacer. Therefore, the detection accuracy of the capacitive sensor is unlikely to decrease.

  (1-1) In the configuration of (1), the spot-like connecting portion is preferably formed by welding a plurality of the insulating films to each other. According to this configuration, the spot-like connecting portion can be easily formed using a means called welding.

  (1-2) In the configuration of (1), the front side electrode portion includes a plurality of front side electrodes arranged in parallel to each other, and the back side electrode portion includes a plurality of back side electrodes arranged in parallel to each other. The plurality of front-side electrodes and the plurality of back-side electrodes extend in directions intersecting each other, and the plurality of front-side electrodes and the plurality of back-side electrodes overlap when viewed from the front side or the back side. It is better to have a configuration in which a plurality of detection units are set in the portion to be performed.

  According to this configuration, the load can be detected by the plurality of detection units. For this reason, the load distribution in the surface direction (direction orthogonal to the front and back directions) of the capacitive sensor can be detected.

  (2) In the configuration of (1), it is preferable that the three adjacent spot-like connecting portions are arranged at the apexes of an equilateral triangle when viewed from the front side or the back side. According to this configuration, the constraining portion and the non-constraining portion can be evenly distributed over the entire surface of the insulating spacer. Further, the restraining portion and the non-restraining portion can be isotropically arranged over the entire surface of the insulating spacer.

  (3) In the configuration of (1) above, it is preferable that the plurality of spot-like connecting portions be arranged at intersections of orthogonal lattices when viewed from the front side or the back side. According to this configuration, the constraining portion and the non-constraining portion can be evenly distributed over the entire surface of the insulating spacer. Further, the restraining portion and the non-restraining portion can be isotropically arranged over the entire surface of the insulating spacer.

  (4) In any one of the constitutions (1) to (3), the area of the front or back surface of the insulating spacer is 100%, and the total area of the plurality of spot-like connecting portions is 0.5% or more and 50 It is better to have a configuration that is set to% or less.

  The reason why the total area of the plurality of spot-like connecting portions occupying the front or back surface of the insulating spacer is 0.5% or more is that when it is less than 0.5%, the plurality of insulating films tend to be displaced in the plane direction. is there. The total area of the plurality of spot-like connecting portions in the insulating spacer is set to 50% or less because when it exceeds 50%, flexibility tends to decrease over the entire surface of the insulating spacer.

  (5) In any one of the constitutions (1) to (4), in the insulating spacer, the surface of the insulating film laminated on the front side is the outer surface, and the back surface of the insulating film laminated on the back side is Out of a pair of the insulating films adjacent to each other in the outer and rear surfaces, the back surface of the insulating film on the front side is the inner back surface, and the surface of the insulating film on the back side is the inner surface, and at least one of the inner back surface and the inner surface The friction coefficient is preferably smaller than that of the outer surface and the outer back surface.

  According to this configuration, the outer surface and the contact surface adjacent to the outer surface in the stacking direction are not easily displaced from each other in the surface direction. In addition, the outer back surface and the contact surface adjacent to the outer back surface in the stacking direction are less likely to be displaced in the surface direction. For this reason, it can suppress that an insulation spacer and adjacent members (for example, a sensor part, a ground electrode, etc.) mutually shift in the surface direction. Further, according to this configuration, the inner back surface and the inner surface adjacent to the inner back surface in the stacking direction are likely to be displaced in the surface direction. For this reason, the flexibility of the insulating spacer can be ensured.

  (6) In the configuration of (5) above, the plurality of insulating films include a first film and a second film, and the friction coefficient of the front and back surfaces of the second film is the front and back of the first film. It is better to make the configuration smaller than the friction coefficient on both sides.

  According to this structure, it can suppress that an insulating spacer and an adjacent member shift | deviate to a surface direction mutually by combining two types of insulating films (a 1st film, a 2nd film). In addition, the flexibility of the insulating spacer can be ensured.

  (7) In the configuration of (6) above, in the insulating spacer, the insulating film laminated on the most front side and the insulating film laminated on the most back side are the first film, and a pair of the first films It is better that the insulating film laminated therebetween is the second film.

  According to this structure, it can suppress that an insulating spacer and an adjacent member shift | deviate to a surface direction mutually by inserting at least 1 2nd film between a pair of front and back 1st films. In addition, the flexibility of the insulating spacer can be ensured.

  (8) In the configuration of (6) or (7), the first film is made of polyethylene not containing a slip agent, and the second film is made of polyethylene containing a slip agent. Is good.

  According to this structure, a 1st film and a 2nd film can be made separately with the presence or absence of a slip agent. The first film and the second film are both made of PE (polyethylene). For this reason, a plurality of insulating films can be easily connected (for example, welded) to each other. That is, the spot-like connecting portion can be easily formed. PE is inexpensive, has a low Young's modulus, and a low dielectric constant. For this reason, the insulating film of this structure has low manufacturing cost, is flexible and easily bends, and has high insulation.

  (9) In the configuration of any one of (1) to (8), the sensor unit is preferably arranged on the back side of the surface of the bedding. The capacitive sensor of the present invention is highly flexible. For this reason, according to this structure, it is hard for a person to feel discomfort.

  (10) In the configuration of any one of (1) to (9), one of the front side electrode portion and the back side electrode portion is an input side electrode portion to which the voltage is applied from the control device, and the other Is an output side electrode part that transmits the amount of electricity to the control device, and the output side electrode part is arranged closer to the ground electrode than the input side electrode part. Better.

  According to this structure, it can suppress that the noise from a peripheral device mixes in the electric quantity regarding the electrostatic capacitance of a sensor part. In addition, the earth electrode hardly affects the amount of electricity related to the capacitance of the sensor unit.

  (11) In the configuration of any one of (1) to (10), a positioning hole penetrating the sensor portion, the insulating spacer, and the ground electrode in the front and back direction, the sensor portion, the insulating spacer, and the ground electrode It is better that the front and back layers of the cover are joined on the radially inner side of the positioning hole.

  According to this configuration, the sensor part, the insulating spacer, and the ground electrode inside the cover can be easily fixed and positioned with respect to the cover by joining both the front and back layers of the cover inside the positioning hole in the radial direction. .

  (11-1) In the configuration of (11), it is preferable that the front and back layers of the cover are welded. According to this configuration, both the front and back layers of the cover can be easily and firmly joined. Moreover, according to this structure, when joining a cover, another members, such as a clip, are unnecessary, for example. For this reason, when a person gets on the upper surface of the cover, riding comfort (for example, sitting comfort, sleeping comfort, etc.) is good.

  According to the present invention, it is possible to provide a capacitance type sensor that can suppress noise from the surroundings and that does not easily reduce detection accuracy.

It is a permeation | transmission top view of the capacitive type sensor of 1st embodiment. It is the II-II direction sectional drawing of FIG. It is a disassembled perspective view of the same capacitive sensor. It is a block diagram of the capacitance type sensor. It is a top view of a back side insulating spacer. FIG. 6 is a cross-sectional view in the VI-VI direction of FIG. 5. It is a permeation | transmission top view of the capacitive type sensor of 2nd embodiment. It is a disassembled perspective view of the same capacitive sensor. It is an enlarged view in the frame IX of FIG. It is XX direction sectional drawing of FIG. (A) is a top view of the back side insulating spacer of other embodiment (the 1). (B) is a top view of the back side insulation spacer of other embodiment (the 2).

  Hereinafter, embodiments of the capacitive sensor of the present invention will be described. In the following drawings, the upper side corresponds to the “front side” of the present invention, and the lower side corresponds to the “back side” of the present invention.

<< First Embodiment >>
<Configuration of capacitive sensor>
First, the configuration of the capacitive sensor of this embodiment will be described. FIG. 1 shows a transparent top view of the capacitive sensor of the present embodiment. FIG. 2 shows a cross-sectional view in the II-II direction of FIG. FIG. 3 shows an exploded perspective view of the capacitance type sensor. FIG. 4 shows a block diagram of the capacitance type sensor. FIG. 5 shows a top view of the back-side insulating spacer. FIG. 6 is a cross-sectional view in the VI-VI direction of FIG.

  As shown in FIG. 1, the capacitive sensor 1 is laid under the bed sheet 9. The capacitance type sensor 1 is based on the fact that the distance between the electrodes of the detection unit CF (distance between the front electrode unit FX and the back electrode unit FY), which will be described later, changes according to the weight of the sleeping person M. The body pressure distribution of the upper body of the person M is measured. Note that another capacitive sensor (not shown) of the same type as the capacitive sensor 1 is disposed below the sheet 9. The capacitance type sensor measures the body pressure distribution of the lower body of the sleeping person M.

  As shown in FIGS. 1 to 4, the capacitive sensor 1 includes a sensor unit F, a connector 20 </ b> F, a harness 21 </ b> F, a control device 22 </ b> F, a cover 23, a front side ground electrode 240, and a back side ground electrode 241. A front-side insulating spacer 250, a back-side insulating spacer 251, a back-end base material 262, four overall connecting portions 293, and a large number of spot-like connecting portions 295.

  The back side ground electrode 241 is included in the concept of the “ground electrode” of the present invention. The back side insulating spacer 251 is included in the concept of “insulating spacer” of the present invention.

[Cover 23]
The cover 23 is made of a flexible soft urethane foam and has a bag shape. The cover 23 has an insulating property. Inside the cover 23, members other than the connector 20F, the harness 21F, and the control device 22F among the members constituting the capacitive sensor 1 are accommodated.

[Sensor part F]
The sensor part F includes a front side electrode part FX, nine front side wirings Fx, a back side electrode part FY, nine back side wirings Fy, a front side base material 260, a back side base material 261, and a front side cover coat 270. The rear cover coat 271, the dielectric layer 280, the reinforcing layer 281, and the detection unit CF are provided. The front side electrode portion FX corresponds to the “input side electrode portion” of the present invention. The back side electrode part FY corresponds to the “output side electrode part” of the present invention.

(Dielectric layer 280, reinforcing layer 281)
The dielectric layer 280 is made of a flexible flexible urethane foam (specifically, PORON (registered trademark of Roger Sinoac Co., Ltd.)) and has a rectangular film shape. The dielectric layer 280 has an insulating property.

  The reinforcing layer 281 is disposed below the dielectric layer 280. The reinforcing layer 281 is made of PET (polyethylene terephthalate) and has a quadrangular film shape. The reinforcing layer 281 is harder (having a higher Young's modulus) than the dielectric layer 280. The reinforcing layer 281 has an insulating property.

(Front side base material 260, front side electrode part FX, front side wiring Fx, front side cover coat 270)
The front substrate 260 is disposed on the upper side of the dielectric layer 280. The front-side base material 260 is made of PET and has a quadrangular film shape. The front side base material 260 has insulating properties.

  The nine front side wirings Fx are screen-printed on the lower surface of the front side base material 260. The front-side wiring Fx is made of silver paste and has conductivity. The front-side wiring Fx electrically connects a later-described front-side electrode FXa and a later-described connector 20F.

  The front side electrode portion FX includes nine front side electrodes FXa. The front side electrode FXa is linear, and is screen-printed on the lower surface of the front side base material 260. The front side electrode FXa extends in the front-rear direction. The nine front electrodes FXa are arranged in the left-right direction. The front electrode FXa is made of carbon paste and has conductivity. The front side electrode FXa partially covers the front side wiring Fx from the lower side. The front side wiring Fx is disposed over the entire length in the longitudinal direction of the front side electrode FXa.

  The front side cover coat 270 is made of polyester and has a quadrangular film shape. The front side cover coat 270 has an insulating property. The front side cover coat 270 is screen-printed on the lower surface of the front side base material 260. The front cover coat 270 covers nine front wirings Fx and nine front electrodes FXa from below.

(Back side base material 261, back side electrode part FY, back side wiring Fy, back side cover coat 271)
The back side substrate 261 is disposed below the reinforcing layer 281. The back side base material 261 is made of PET and has a quadrangular film shape. The back side base material 261 has an insulating property.

  The nine back side wirings Fy are screen-printed on the upper surface of the back side base material 261. The back side wiring Fy is made of silver paste and has conductivity. The back side wiring Fy electrically connects a back side electrode FYa described later and a connector 20F described later.

  The back-side electrode part FY includes nine back-side electrodes FYa. The back side electrode FYa is linear and is screen-printed on the upper surface of the back side base material 261. The back side electrode FYa extends in the left-right direction. The nine back electrodes FYa are arranged in the front-rear direction. The back electrode FYa is made of carbon paste and has conductivity. The back side electrode FYa partially covers the back side wiring Fy from above. The back side wiring Fy is disposed over the entire length in the longitudinal direction of the back side electrode FYa.

  The back side cover coat 271 is made of polyester and has a quadrangular film shape. The back side cover coat 271 has insulating properties. The back side cover coat 271 is screen-printed on the upper surface of the back side base material 261. The back side cover coat 271 covers nine back side wirings Fy and nine back side electrodes FYa from above.

(Detector CF)
When viewed from above, the nine front electrodes FXa and the nine back electrodes FYa are arranged in a lattice pattern. A detection unit CF is set in a portion where the front side electrode FXa and the back side electrode FYa overlap. A total of 81 detectors CF are arranged.

[Front-side insulating spacer 250, Front-side ground electrode 240]
The front side insulating spacer 250 is disposed on the upper side of the front side base material 260. The front-side insulating spacer 250 is made of PE and has a quadrangular film shape. The front insulating spacer 250 has an insulating property.

  On the upper surface (surface on the outer side in the front-back direction) of the front-side insulating spacer 250, front-side ground wiring (not shown) made of silver paste is screen-printed on the entire surface. The front-side ground electrode 240 is made of carbon paste and has a rectangular film shape. The front side ground electrode 240 has conductivity. The front side ground electrode 240 is entirely screen-printed on the upper surface of the front side ground wiring. The front side ground electrode 240 is electrically grounded via the front side ground wiring.

[Back-side insulating spacer 251, back-side ground electrode 241, back-end base material 262]
The back side insulating spacer 251 is disposed below the back side base material 261. As shown in FIGS. 3 and 6, the back insulating spacer 251 is composed of two first films 251 d and two second films 251 e. The first film 251d and the second film 251e are each made of PE and have a quadrangular film shape. The first film 251d and the second film 251e each have insulating properties.

  The first film 251d does not contain a slip agent. On the other hand, the second film 251e contains a slip agent. For this reason, the friction coefficients (static friction coefficient and dynamic friction coefficient) of the upper and lower surfaces of the second film 251e are smaller than the friction coefficients (static friction coefficient and dynamic friction coefficient) of the upper and lower surfaces of the first film 251d.

  One of the two first films 251d is laminated on the uppermost side of the back-side insulating spacer 251. The other of the two first films 251d is laminated on the lowermost side of the back-side insulating spacer 251. The two second films 251e are interposed between the two first films 251d. A slipping agent is exposed on the upper and lower surfaces of the second film 251e.

  The back end base material 262 is disposed below the back side insulating spacer 251. The back end base material 262 is made of PET and has a quadrangular film shape. The back end base material 262 has an insulating property.

  On the upper surface of the back end base material 262, a back side ground wiring (not shown) made of silver paste is screen-printed on the entire surface. The back side ground electrode 241 is made of carbon paste and has a quadrangular film shape. The back side ground electrode 241 has conductivity. The back side ground electrode 241 is screen-printed on the entire upper surface of the back side ground wiring. The back-side ground electrode 241 is disposed below the back-side insulating spacer 251 (outside in the front-back direction). The back side ground electrode 241 is electrically grounded via the back side ground wiring.

[Overall connection portion 293, spot-like connection portion 295]
As shown by the solid line hatching in FIG. 5, among the many spot-like connecting portions 295, the three adjacent spot-like connecting portions 295 are arranged at the apexes of an equilateral triangle when viewed from the upper side. The spot-like connecting portion 295 is formed by welding four insulating films (two first films 251d and two second films 251e). As described above, the four insulating films are integrated by the large number of spot-like connecting portions 295 so as not to be displaced in the surface direction (horizontal direction). The spot-like connecting portion 295 has an annular shape (a donut shape).

  As shown in FIG. 3, the four overall connecting portions 293 are arranged at the four corners of the front-side ground electrode 240 when viewed from above. The overall connecting portion 293 is a resin-made binding tool having retaining portions at both upper and lower ends. The entire connecting portion 293 passes through the front side ground electrode 240, the front side insulating spacer 250, the sensor unit F, the back side insulating spacer 251, the back side ground electrode 241, and the back end base material 262 from the upper side to the lower side. As described above, these members are integrated by the four overall connecting portions 293 so as not to be displaced from each other in the surface direction.

  In the back-side insulating spacer 251, a portion where a large number of spot-like connecting portions 295 and four whole connecting portions 293 are arranged is a restraining portion 251b. In the restraining portion 251b, the four insulating films are restrained to each other. For this reason, each insulating film cannot shift | deviate to a surface direction with respect to another insulating film.

  On the other hand, in the back-side insulating spacer 251, the portion where the large number of spot-like connecting portions 295 and the four overall connecting portions 293 are not disposed is the non-restraining portion 251c. In the unconstrained portion 251c, the four insulating films are not restrained from each other. For this reason, each insulating film can shift | deviate to a surface direction with respect to another insulating film.

[Connector 20F, harness 21F, control device 22F]
As shown in FIG. 1, the connector 20 </ b> F is disposed at the left front corner of the capacitive sensor 1. Nine front-side wirings Fx and nine back-side wirings Fy are electrically connected to the connector 20F in a state where insulation is ensured. The harness 21F electrically connects the connector 20F and a control device 22F described later.

  As illustrated in FIG. 4, the control device 22 </ b> F includes a power source 220, an input side switching circuit 221, an output side switching circuit 222, and a capacitance detection unit 223. The power supply 220 applies an alternating voltage (specifically, a rectangular wave voltage) to the nine front electrodes FXa via the nine front wirings Fx.

  The input side switching circuit 221 includes nine switches (not shown). One end of the input side switching circuit 221 is connected to the power source 220. The other end of the input side switching circuit 221 is connected to nine front side wirings Fx. The input side switching circuit 221 switches and connects the nine front side wirings Fx to the power source 220 in order.

  The output side switching circuit 222 includes nine switches (not shown). One end of the output side switching circuit 222 is connected to nine back wirings Fy. The other end of the output side switching circuit 222 is connected to the capacitance detection unit 223. The output side switching circuit 222 switches and connects the nine back side wirings Fy to the capacitance detection unit 223 in order.

  The capacitance detection unit 223 includes the detection unit CF of the total of 81 detection units CF, which is related to the front side electrode FXa to which the voltage is applied and the back side electrode FYa connected to the capacitance detection unit 223. Measure the capacitance. Specifically, the capacitance detection unit 223 converts the charging current of the detection unit CF into capacitance. And the said electrostatic capacitance is measured. The charging current is included in the concept of “amount of electricity related to capacitance” of the present invention. A total of 81 detectors CF are sequentially applied with voltages in a scanning manner. For this reason, the body pressure distribution of the upper body of the sleeping person M can be measured.

[Effects of capacitive sensor]
Next, the function and effect of the capacitive sensor of this embodiment will be described. According to the capacitive sensor 1 of the present embodiment, the sensor unit F includes a total of 81 detection units CF in the surface direction. For this reason, the body pressure distribution of the upper body of the person M can be detected.

  In addition, the capacitive sensor 1 of this embodiment includes a front-side insulating spacer 250 and a front-side ground electrode 240. For this reason, the environmental noise resulting from the bedding (for example, electric blanket etc.) hung on the person M can be suppressed. Therefore, the detection accuracy can be increased.

  Further, the capacitive sensor 1 of this embodiment includes a back side insulating spacer 251 and a back side ground electrode 241. For this reason, the environmental noise resulting from the bedding and floor which the person M has spread can be suppressed. Therefore, the detection accuracy can be increased.

  In addition, when the inter-electrode distance between the back electrode FYa and the back side ground electrode 241 is less than a certain value with respect to the capacitance Ca of the detection unit CF, the current caused by the capacitance Ca causes the back side ground electrode 241 to flow. Escape to the ground. In this regard, the capacitive sensor 1 of this embodiment includes a back-side insulating spacer 251. For this reason, the electric current resulting from the electrostatic capacitance Ca can be sent to the electrostatic capacitance detection unit 223 of the control device 22F via the back side electrode FYa and the back side wiring Fy.

  Similarly, when the inter-electrode distance between the front side electrode FXa and the front side ground electrode 240 is less than a certain value with respect to the capacitance Ca of the detection unit CF, the current caused by the capacitance Ca is the front side ground. It escapes to the ground through the electrode 240. In this regard, the capacitive sensor 1 of this embodiment includes a front-side insulating spacer 250. For this reason, the electric current resulting from the electrostatic capacitance Ca can be sent to the electrostatic capacitance detection unit 223 of the control device 22F via the back side electrode FYa and the back side wiring Fy.

  Further, according to the capacitive sensor 1 of the present embodiment, the nine front wirings Fx, the nine front electrodes FXa, and the front cover coat 270 are screen-printed on the lower surface of the front substrate 260. For this reason, the shape accuracy and position accuracy of these members increase.

  Similarly, according to the capacitive sensor 1 of the present embodiment, the nine back wirings Fy, the nine back electrodes FYa, and the back cover coat 271 are screen-printed on the upper surface of the back substrate 261. For this reason, the shape accuracy and position accuracy of these members increase.

  Further, a front side laminate including the “front side base material 260, nine front side wirings Fx, nine front side electrodes FXa, front side cover coat 270” and the above “back side base material 261, nine back side wirings Fy, 9”. The configuration of the back side laminated body including the back side electrode FYa of the book and the back side cover coat 271 "is the same. That is, when the front side laminate is turned upside down and rotated appropriately in the horizontal plane, the back side laminate is obtained. Similarly, when the back side laminate is turned upside down and rotated appropriately in the horizontal plane, the front side laminate is obtained. For this reason, the laminated body of the same structure can be used as a front side laminated body and a back side laminated body.

  Further, according to the capacitive sensor 1 of the present embodiment, the reinforcing layer 281 is disposed below the dielectric layer 280. For this reason, the durability of the dielectric layer 280 is increased. Further, as compared with the case where the reinforcing layer 281 is disposed on the upper side of the dielectric layer 280, the dielectric layer 280 can be locally compressed only in a portion to which a load is applied. For this reason, the detection accuracy of the body pressure distribution can be increased.

  Further, according to the capacitive sensor 1 of the present embodiment, wiring (over the entire surface of the electrodes (front side electrode FXa, back side electrode FYa, front side ground electrode 240, back side ground electrode 241) as viewed from the front side or the back side) Front side wiring Fx, back side wiring Fy, front side ground wiring, back side ground wiring) are arranged. The wiring has a smaller electric resistance than the electrode. For this reason, it is possible to reduce the electrical resistance of the entire electrode by spreading the wiring over the entire electrode. In addition, variation in electrical resistance of the entire electrode can be reduced. In addition, it is possible to reduce variations in detection values between a plurality of detection units CF (for example, between the detection unit CF at the front end and the detection unit CF at the rear end). Therefore, the detection accuracy of the body pressure distribution can be increased.

  Further, according to the capacitive sensor 1 of the present embodiment, the back-side insulating spacer 251 is composed of a plurality of insulating films (two first films 251d and two second films 251e) stacked in the vertical direction. It is configured. For this reason, the vertical thickness of the back side insulating spacer 251 (that is, the distance between the back side ground electrode 241 and the back side electrode FYa) can be easily adjusted by changing the number of laminated insulating films.

  As shown in FIGS. 3, 5, and 6, the back-side insulating spacer 251 of the capacitive sensor 1 of this embodiment includes a restraining portion 251b. For this reason, it can control that a plurality of insulating films shift mutually. Further, the back side insulating spacer 251 includes a non-restraining portion 251c. For this reason, it can suppress that a deformation | transformation (for example, bending deformation) of a some insulating film restrains mutually. Moreover, it can accept | permit that the non-restraining part 251c of arbitrary pairs of adjacent insulating films slides mutually.

  When the insulating film is bent and deformed, the amount of expansion of the outer surface in the radius direction of the curvature relative to the inner surface in the radius direction of the curvature may be smaller as the vertical thickness of the insulating film is smaller. For example, when a load is applied to the insulating film from above, the extension amount of the lower surface relative to the upper surface of the insulating film may be smaller as the vertical thickness of the insulating film is smaller. Thus, the smaller the vertical thickness of the insulating film, the easier the insulating film bends.

  In this regard, according to the capacitive sensor 1 of the present embodiment, the back-side insulating spacer 251 is composed of a plurality of insulating films instead of a single insulating film. Further, the back side insulating spacer 251 includes a non-restraining portion 251c. For this reason, compared with the back side insulation spacer 251 which consists of a single insulation film (the vertical thickness of the said insulation film is the sum total of the vertical direction thickness of four insulation films), the back side insulation spacer of this embodiment Each of the four insulating films 251 is easy to bend. Therefore, the back side insulating spacer 251 of this embodiment is easy to bend. Therefore, the sleeping comfort is good.

  Thus, according to the capacitive sensor 1 of the present embodiment, the vertical thickness of the back insulating spacer 251 (that is, the distance between the back ground electrode 241 and the back electrode FYa) is sufficiently secured. The bending deformation of the back side insulating spacer 251 can be facilitated.

  Moreover, as shown in FIG. 6, in the restraint part 251b, the some insulating film is restrained mutually. For this reason, the restraining part 251b is less likely to bend than the non-restraining part 251c. In other words, the restraining portion 251b is less flexible (apparent bending rigidity) than the non-restraining portion 251c. Therefore, the detection accuracy is likely to vary between the detection unit CF corresponding to the constraint unit 251b and the detection unit CF corresponding to the non-restriction unit 251c.

  In addition, in the restraining portion 251b, the plurality of insulating films are in close contact with each other. For this reason, the vertical thickness tends to be small. On the other hand, in the non-restraining portion 251c, the plurality of insulating films are independent from each other. For this reason, each insulating film is easily deformed independently. Therefore, the vertical thickness tends to increase. Also in this respect, the detection accuracy is likely to vary between the detection unit CF corresponding to the constraint unit 251b and the detection unit CF corresponding to the non-restriction unit 251c.

  In this regard, the capacitive sensor 1 of the present embodiment includes a large number of spot-like connecting portions 295 arranged in a dot pattern when viewed from the upper side or the lower side. For this reason, the detection accuracy is unlikely to vary between the detection unit CF corresponding to the constraint unit 251b and the detection unit CF corresponding to the non-restriction unit 251c. Therefore, the detection accuracy of the capacitive sensor 1 is unlikely to decrease.

  Further, the spot-like connecting portion 295 is formed by welding a plurality of insulating films to each other. For this reason, many spot-like connection parts 295 can be formed easily.

  Further, as shown in FIG. 5, the three spot-like connecting portions 295 adjacent to each other are arranged at the apexes of an equilateral triangle when viewed from the upper side or the lower side. For this reason, the restraining part 251b and the non-restraining part 251c can be evenly distributed over the entire surface of the back-side insulating spacer 251. Further, the restraining portion 251b and the non-restraining portion 251c can be disposed isotropically over the entire surface of the back side insulating spacer 251.

  Further, assuming that the area of the upper surface or the lower surface of the back-side insulating spacer 251 is 100%, the total area of all spot-like connecting portions 295 is set to 0.5% or more and 50% or less. Specifically, it is set to 25%. For this reason, a plurality of insulating films are unlikely to be displaced in the plane direction. In addition, the flexibility is unlikely to decrease over the entire surface of the back insulating spacer 251.

  The back-side insulating spacer 251 is composed of two first films 251d and two second films 251e. The first film 251d does not contain a slip agent. On the other hand, the second film 251e contains a slip agent. For this reason, the friction coefficients (static friction coefficient and dynamic friction coefficient) of the upper and lower surfaces of the second film 251e are smaller than the friction coefficients (static friction coefficient and dynamic friction coefficient) of the upper and lower surfaces of the first film 251d.

  In the back side insulating spacer 251, one of the two first films 251d is laminated on the uppermost side. For this reason, the upper surface (outer surface) of the upper first film 251d and the lower surface of the sensor unit F (specifically, the lower surface of the back-side base material 261) are not easily displaced in the surface direction (horizontal direction). Therefore, it is difficult for the person M to feel “slip”.

  The other of the two first films 251d is laminated on the lowermost side. For this reason, the lower surface (outer back surface) of the lower first film 251d and the upper surface of the back end base material 262 (back side ground electrode 241) are not easily displaced in the surface direction. Therefore, it is difficult for the person M to feel “slip”.

  In addition, the two second films 251e are interposed between the two first films 251d. A slipping agent is exposed on the upper and lower surfaces of the second film 251e. For this reason, the upper surface (inner surface) of the upper second film 251e and the lower surface (inner surface) of the upper first film 251d are likely to be displaced in the surface direction. Further, the lower surface (inner back surface) of the lower second film 251e and the upper surface (inner surface) of the lower first film 251d are liable to be displaced in the surface direction. Further, the lower surface (inner back surface) of the upper second film 251e and the upper surface (inner surface) of the lower second film 251e are liable to be displaced in the surface direction. Therefore, the flexibility of the back side insulating spacer 251 can be ensured.

  Further, according to the capacitive sensor 1 of the present embodiment, “first film 251d → second film 251e → second film 251e → first film 251d” from the upper side to the lower side by the following lamination method. In this order, four insulating films can be easily laminated. That is, first, the first film 251d and the second film 251e are each formed into a cylindrical shape. Next, a double cylindrical film is produced by relatively inserting the second film 251e inside the first film 251d in the radial direction. Finally, the double cylindrical film is crushed in the radial direction, and both ends in the diametrical direction are cut over the entire length in the axial direction. By the lamination method, four insulating films can be easily laminated.

  Further, according to the capacitive sensor 1 of the present embodiment, the first film 251d and the second film 251e can be made separately depending on the presence or absence of a slip agent. Further, the base material (main component) of the first film 251d and the second film 251e is both PE. For this reason, a plurality of insulating films (two first films 251d and two second films 251e) can be easily welded together. That is, a large number of spot-like connecting portions 295 can be easily formed. PE is inexpensive, has a low Young's modulus, and a low dielectric constant. For this reason, an insulating film has low manufacturing cost, is flexible and easily bends, and has high insulating properties. Moreover, as shown in FIG. 1, the sensor part F is laid under the bed sheet 9 of the bed. For this reason, it is difficult for the person M to feel uncomfortable.

  Hereinafter, as shown by dotted hatching in FIG. 5, a capacitive sensor (hereinafter referred to as “pre-improved sensor”) in which a strip-shaped coupling portion 294 is arranged in place of the spot-shaped coupling portion 295. The operation and effect of the capacitive sensor 1 of the present embodiment will be described.

  In the case of the sensor before improvement, the plurality of strip-like connecting portions 294 are arranged in a stripe shape when viewed from the upper side or the lower side. The strip-shaped connecting portion 294 extends in the front-rear direction. The restraining portions 251b and the non-restraining portions 251c are alternately arranged in the left-right direction over the entire surface of the back-side insulating spacer 251. In the case of the sensor before improvement, the low flexibility portion (restraint portion 251b) and the high flexibility portion (non-restraint portion 251c) are alternately arranged in the left-right direction over the entire surface of the back insulating spacer 251. Will be. For this reason, flexibility tends to vary over the entire surface of the back-side insulating spacer 251. In addition, the thickness in the vertical direction tends to vary over the entire surface of the back-side insulating spacer 251. Therefore, detection accuracy tends to vary over the entire surface of the back insulating spacer 251. Therefore, the detection accuracy of the sensor before improvement tends to be lowered.

  On the other hand, the capacitive sensor 1 of this embodiment includes a plurality of spot-like connecting portions 295 arranged in a dot pattern when viewed from the upper side or the lower side. The restraining portions 251b are distributed and arranged over the entire surface of the back side insulating spacer 251. For this reason, flexibility and vertical thickness are less likely to vary across the entire surface of the back-side insulating spacer 251. Therefore, the detection accuracy is unlikely to vary over the entire surface of the back insulating spacer 251. Therefore, the detection accuracy of the capacitive sensor 1 is unlikely to decrease.

  Moreover, in the case of the sensor before improvement, all the strip | belt-shaped connection parts 294 are extended in the front-back direction. For this reason, anisotropy is likely to occur in the flexibility of the back-side insulating spacer 251. Therefore, in order to ensure good sleeping comfort, the extending direction (front-rear direction) of the belt-like connecting portion 294 and the height direction of the sleeping person M need to be matched. Accordingly, the degree of freedom in relative arrangement between the back-side insulating spacer 251 and the direction in which the person M sleeps (the arrangement direction of the bedding (bed, futon, etc.)) decreases.

  On the other hand, the capacitive sensor 1 of this embodiment includes a plurality of spot-like connecting portions 295 arranged in a dot pattern when viewed from the upper side or the lower side. For this reason, anisotropy hardly occurs in the flexibility of the back-side insulating spacer 251. Therefore, it is not necessary to consider the arrangement of the plurality of spot-like connecting portions 295 in order to ensure good sleeping comfort. Therefore, the relative freedom of relative arrangement between the back-side insulating spacer 251 and the direction in which the person M sleeps is unlikely to decrease.

  Further, in the pre-improved sensor, when the front electrode FXa shown in FIG. 7 and the strip-like connecting portion 294 shown in FIG. 5 are parallel to each other, the front electrode FXa ( That is, it is conceivable that the nine detection units CF) arranged in the front-rear direction and the restraint unit 251b overlap in the vertical direction. This part is less flexible. In addition, the vertical thickness of this portion is reduced. In addition, regarding another front electrode FXa, it is conceivable that the front electrode FXa (that is, nine detection parts CF arranged in the front-rear direction) and the non-restraining part 251c overlap in the vertical direction over the entire length in the front-rear direction. This part is more flexible. In addition, the vertical thickness of this portion increases.

  As described above, in the pre-improved sensor, when the front electrode FXa and the strip-shaped connecting portion 294 are parallel to each other, the constraining portion 251b (the portion with low flexibility, the thickness in the vertical direction is small) over the entire surface of the back side insulating spacer 251. Part) tends to continue in the front-rear direction. In addition, the unconstrained portion 251c (a portion having high flexibility and a portion having a large vertical thickness) tends to continue in the front-rear direction over the entire surface of the back insulating spacer 251. Further, it is difficult to improve the flatness of the back insulating spacer 251. Therefore, the detection accuracy of the sensor before improvement tends to be lowered. Note that, similarly, when the back electrode FYa and the belt-like connecting portion 294 are parallel to each other, the detection accuracy of the sensor before improvement is likely to decrease.

  Here, in the pre-improved sensor, in order to suppress a decrease in detection accuracy, the front electrode FXa and the strip-shaped connecting portion 294 are arranged non-parallel to each other, and the back-side electrode FYa and the strip-shaped connecting portion 294 are not parallel to each other. Need to be placed in. For example, it is necessary to extend the belt-like connecting portion 294 in the right front-left rear direction or the left front-right rear direction shown in FIG. However, if it carries out like this, the freedom degree of relative arrangement | positioning with the sensor part F and the back side insulation spacer 251 will fall.

  On the other hand, as shown in FIGS. 3 and 5, the capacitive sensor 1 of the present embodiment includes a large number of spot-like connecting portions 295 arranged in a dot pattern when viewed from the upper side or the lower side. ing. The restraining portions 251b are dispersed and arranged intermittently over the entire surface of the back-side insulating spacer 251. For this reason, the constraining portion 251b (a portion having a low flexibility and a portion having a small vertical thickness) is difficult to continue over the entire surface of the back-side insulating spacer 251. In addition, the unconstrained portion 251c (a portion with high flexibility and a portion with a large vertical thickness) is difficult to continue over the entire surface of the back-side insulating spacer 251. Further, it is easy to improve the flatness of the back insulating spacer 251. Therefore, the detection accuracy of the capacitive sensor 1 is unlikely to decrease. Further, the degree of freedom of relative arrangement between the sensor unit F and the back-side insulating spacer 251 is unlikely to decrease.

  In the case of the sensor before improvement, as shown in FIG. 5, the arbitrary non-restraining portion 251c of the back side insulating spacer 251 is a pair of restraining portions 251b (band-like connecting portions 294) extending from the left and right sides over the entire length in the front-rear direction. It is sandwiched between. For this reason, when the strip | belt-shaped connection part 294 is formed by welding four insulating films mutually, restraint part 251b (over the full length in the front-back direction from right and left both sides with respect to arbitrary non-restraint parts 251c ( The heat at the time of welding will be transmitted in the strip | belt-shaped connection part 294). Therefore, in the non-restraining part 251c, each insulating film is easily thermally deformed into a wave shape (wrinkle shape). Therefore, the detection accuracy of the capacitive sensor 1 tends to decrease.

  Further, in the unconstrained portion 251c, when the upper first film 251d is deformed in a wave shape, a portion of the dielectric layer 280 corresponding to the peak portion (portion protruding upward) of the first film 251d is Easy to deform. On the other hand, the portion of the dielectric layer 280 corresponding to the valley portion (portion protruding downward) of the first film 251d is not easily deformed. Also in this point, the detection accuracy of the capacitive sensor 1 is likely to be lowered.

  In this regard, the capacitive sensor 1 of the present embodiment includes a large number of spot-like connecting portions 295 arranged in a dot pattern when viewed from the upper side or the lower side. For this reason, the arbitrary non-restraining portion 251c is not easily surrounded by the restraining portion 251b (spot-shaped connecting portion 295). Therefore, in the non-restraining portion 251c, each insulating film is not easily thermally deformed into a wave shape (wrinkle shape). Therefore, the detection accuracy of the capacitive sensor 1 tends to decrease.

<< Second Embodiment >>
The difference between the capacitive sensor of the present embodiment and the capacitive sensor of the first embodiment is that the entire connecting portion is formed by welding the upper and lower layers of the cover. Further, the front side insulating spacer and the front side ground electrode are not arranged. Here, differences will be mainly described.

  FIG. 7 shows a transparent top view of the capacitive sensor of the present embodiment. FIG. 8 shows an exploded perspective view of the capacitance type sensor. FIG. 9 shows an enlarged view in the frame IX of FIG. FIG. 10 is a cross-sectional view in the XX direction of FIG.

  In FIG. 7, members corresponding to those in FIG. 8, members corresponding to those in FIG. 3 are denoted by the same reference numerals. 10, members corresponding to those in FIG. 2 are denoted by the same reference numerals. In FIG. 7, the sheet 9 and the person M shown in FIG. 1 are omitted.

  As shown in FIGS. 7 to 10, four cover holes 230 are formed in the cover 23 of the capacitive sensor 1. As shown in FIG. 10, the cover hole 230 penetrates the upper and lower layers (front and back layers) of the cover 23 in the vertical direction.

  As shown in FIGS. 8 and 10, four positioning holes 8 are formed in the members (specifically, the sensor unit F, the back side ground electrode 241, and the back side insulating spacer 251) accommodated in the cover 23. ing. As shown in FIG. 10, the positioning hole 8 penetrates the member accommodated in the cover 23 in the up-down direction. The hole diameter (diameter) D1 of the positioning hole 8 is larger than the hole diameter (diameter) D2 of the cover hole 230. An entire connecting portion 293 is disposed on the radially inner side of the positioning hole 8 and on the radially outer side of the cover hole 230. The entire connecting portion 293 is formed by welding the upper and lower layers of the cover 23. As shown by hatching in FIG. 9, when viewed from above, the entire connecting portion 293 has an annular shape (doughnut shape) with the cover hole 230 as the center. The overall connecting portion 293 positions the cover 23 and the member accommodated in the cover 23. Moreover, the whole connection part 293 positions the members accommodated in the cover 23 with respect to each other.

  In the back-side insulating spacer 251, a portion where a large number of spot-like connecting portions 295 and four whole connecting portions 293 are arranged is a restraining portion 251b. In the restraining portion 251b, a plurality of insulating films (two first films 251d and two second films 251e) are restrained to each other. For this reason, each insulating film cannot shift | deviate to a surface direction with respect to another insulating film.

  On the other hand, in the back-side insulating spacer 251, the portion where the large number of spot-like connecting portions 295 and the four overall connecting portions 293 are not disposed is the non-restraining portion 251c. In the non-restraining portion 251c, the plurality of insulating films are not restrained from each other. For this reason, each insulating film can shift | deviate to a surface direction with respect to another insulating film.

  The capacitive sensor of the present embodiment has the same effects as the capacitive sensor of the first embodiment with respect to the parts having the same configuration. Further, according to the capacitive sensor 1 of the present embodiment, as shown in FIG. 10, the upper and lower layers of the cover 23 are welded on the radially inner side of the positioning hole 8. For this reason, it is possible to easily fix and position the sensor portion F, the back side insulating spacer 251 and the back side ground electrode 241 inside the cover 23 with respect to the cover 23. Moreover, when joining the cover 23, another member, such as a clip, is unnecessary, for example. For this reason, when the person M rides on the upper surface of the cover 23, riding comfort (for example, sitting comfort, sleeping comfort, etc.) is good.

  As shown in FIG. 10, the upper and lower layers of the cover 23 are welded and sealed on the outer side in the radial direction of the cover hole 230. For this reason, foreign matter (solid, liquid, etc.) can be prevented from entering the cover 23.

  Further, the cover hole 230 penetrates the cover 23 in the vertical direction. For this reason, the cover hole 230 can ensure air permeability and moisture permeability in the up-down direction of the cover 23. Therefore, for example, when the cover 23 is laid, it is easy to vent the air below the cover 23. For this reason, it is easy to install the capacitive sensor 1. In addition, moisture tends to escape from the upper side to the lower side of the cover 23. For this reason, the person M on the capacitive sensor 1 is unlikely to become uncomfortable.

  Further, as shown in FIGS. 7 and 9, the cover hole 230, the positioning hole 8, and the entire connecting portion 293 are arranged avoiding the front side electrode FXa and the back side electrode FYa. For this reason, the detection accuracy of the capacitive sensor 1 is unlikely to decrease.

  As shown in FIG. 10, the back side electrode part (output side electrode part) is arranged closer to the back side ground electrode 241 than the front side electrode part (input side electrode part) FX. For this reason, it can suppress that the noise from a peripheral device mixes in the electric quantity regarding the electrostatic capacitance of the sensor part F. FIG. Further, the back-side ground electrode 241 hardly affects the amount of electricity related to the capacitance of the sensor unit F.

  As shown in FIG. 10, the capacitive sensor 1 of the present embodiment is not provided with the front-side insulating spacer 250 and the front-side ground electrode 240 shown in FIG. For this reason, the vertical thickness of the capacitive sensor 1 can be reduced.

<< Other >>
The embodiment of the capacitive sensor of the present invention has been described above. However, the embodiment is not particularly limited to the above embodiment. Various modifications and improvements that can be made by those skilled in the art are also possible.

  The structure of the insulating film (first film 251d, second film 251e) is not particularly limited. An uneven shape may be imparted to at least one of the upper surface and the lower surface. Moreover, you may insert a slit in at least one among an upper surface and a lower surface. Moreover, you may use the embossing sheet | seat which has an uneven | corrugated shape as an insulating film. That is, the friction coefficient of the upper surface and the lower surface (included in the concept of “outer surface”, “outer back surface”, “inner back surface”, “inner surface”) of the present invention may be adjusted according to the structure of the insulating film.

  In the said embodiment, the back side insulating spacer 251 was comprised with the some insulating film. However, the front-side insulating spacer 250 may be composed of a plurality of insulating films. Moreover, you may comprise the front side insulating spacer 250 and the back side insulating spacer 251 with a plurality of insulating films.

  The number of arrangement of the insulating spacers (front side insulating spacer 250, back side insulating spacer 251) is not particularly limited. An insulating spacer may be disposed only on the front side or only on the back side of the sensor unit F. That is, insulating spacers may be disposed on at least one of the upper and lower sides of the sensor unit F. Similarly, the number of ground electrodes (the front side ground electrode 240 and the back side ground electrode 241) is not particularly limited. You may arrange | position a ground electrode only in the front side of the sensor part F, or only in the back side. That is, the ground electrode may be disposed on at least one of the upper and lower sides of the sensor unit F.

  Further, the number of laminated insulating films in the back side insulating spacer 251 is not particularly limited. The number of laminated insulating films may be plural (at least two). Further, the thickness in the vertical direction of each insulating film may or may not be constant.

  The structure of the whole connection part 293 and the spot-like connection part 295 is not specifically limited. Each member may be fixed by welding, adhesion, a hook-and-loop fastener, an adhesive tape (for example, a double-sided tape), a stapler, a clip, or the like. There are no particular limitations on the number, shape, and arrangement pattern of the overall connecting portions 293 and spot-like connecting portions 295. For example, an elliptical shape or a polygonal shape (regular triangle, regular square, regular hexagon, etc.) may be used. FIG. 11A shows a top view of a back-side insulating spacer according to another embodiment (part 1). FIG. 11B is a top view of the back-side insulating spacer of the other embodiment (part 2). In addition, about the site | part corresponding to FIG. 5, it shows with the same code | symbol.

  As shown in FIGS. 11A and 11B, a plurality of spot-like connecting portions 295 may be arranged at the intersections of orthogonal lattices when viewed from the upper side or the lower side. As shown in FIG. 11 (a), the orientation of the orthogonal lattice composed of a plurality of spot-like connecting portions 295 and the orthogonality composed of a plurality of capacitance electrodes (9 front electrodes FXa and 9 back electrodes FYa). You may make the direction of a grating | lattice (refer FIG. 1) correspond. As shown in FIG. 11 (b), the orientation of the orthogonal lattice made up of the plurality of spot-like connecting portions 295 and the direction of the orthogonal lattice made up of the plurality of capacitance electrodes (see FIG. 1) are 45 ° to each other. It may be shifted. Thus, the difference in the orientation of both orthogonal lattices is not particularly limited. Further, as shown in FIGS. 11A and 11B, a round spot-like connecting portion 295 may be arranged instead of an annular shape.

  Moreover, the joining method of the upper and lower layers of the cover 23 shown in FIG. 10 is not particularly limited. For example, the upper and lower layers may be joined using welding, adhesion, a hook-and-loop fastener, an adhesive tape (for example, a double-sided tape), a stapler, a clip, or the like. Moreover, the cover hole 230 shown in FIG.

  The number, shape, and arrangement pattern of the front side electrode FXa and the back side electrode FYa are not particularly limited. It is only necessary to set at least one detection unit CF. In the case where a plurality of detection units CF are arranged, the arrangement density of the detection units CF may not be constant over the entire detection area (area where the body pressure distribution can be detected). For example, the detection unit CF may be arranged densely in a portion where body pressure tends to concentrate and sparsely in a portion where body pressure is difficult to concentrate. Further, one of the front side electrode FXa and the back side electrode FYa may be arranged concentrically. In addition, the other may be arranged radially concentrically with one.

  In the above-described embodiment, nine front-side wirings Fx, nine front-side electrodes FXa, and a front-side cover coat 270 are screen-printed on the lower surface of the front-side base material 260. In addition, nine backside wirings Fy, nine backside electrodes FYa, and a backside cover coat 271 were screen-printed on the upper surface of the backside base material 261. However, each member may be printed by other printing methods such as an inkjet printing method, a flexographic printing method, a gravure printing method, a pad printing method, a lithography method, and a dispenser printing method. Moreover, you may arrange | position each said member by other arrangement | positioning methods, such as adhesion | attachment, sticking, and shaping | molding.

  Further, nine front-side wirings Fx, nine front-side electrodes FXa, and a front-side cover coat 270 may be printed on the upper surface of the dielectric layer 280. Similarly, nine backside wirings Fy, nine backside electrodes FYa, and a backside cover coat 271 may be printed on the lower surface of the dielectric layer 280. This increases the positional accuracy of the detection unit CF.

  Further, the front and back direction of the capacitive sensor of the present invention may not be the vertical direction. For example, the front and back direction may be the front-rear direction and the left-right direction (for example, when a capacitive sensor is arranged on a wall surface). The capacitive sensor of the present invention may be arranged on a curved surface as well as a flat surface. When arranged on a curved surface, the capacitive sensor bends along the shape of the curved surface.

  In the above embodiment, the front electrode portion FX is connected to the input side switching circuit 221 and the back side electrode portion FY is connected to the output side switching circuit 222. However, the connection destination of the front side electrode portion FX and the back side electrode portion FY is There is no particular limitation. For example, the front side electrode unit FX may be connected to the output side switching circuit 222, and the back side electrode unit FY may be connected to the input side switching circuit 221.

  Insulating member (for example, cover 23, front side insulating spacer 250, back side insulating spacer 251, front side base material 260, back side base material 261, back end base material 262, front side cover coat 270, back side cover coat 271 and dielectric layer 280 The material of the reinforcing layer 281 and the like is not particularly limited. What is necessary is just to have the softness | flexibility of the grade which curves with the weight of the person M. For example, a resin or an elastomer can be used. As the resin, PET, PE, PI (polyimide), PEN (polyethylene naphthalate), or the like can be used. Elastomers include silicone rubber, acrylonitrile-butadiene copolymer rubber, acrylic rubber, epichlorohydrin rubber, chlorosulfonated polyethylene rubber, chlorinated polyethylene rubber, urethane rubber, ethylene propylene copolymer rubber, natural rubber, styrene-butadiene rubber. Etc. can be used. Further, as the material of the member having insulating properties, a resin or elastomer foam (for example, urethane foam, polyethylene foam, polystyrene foam, etc.) may be used. Further, a woven fabric or a nonwoven fabric of resin fibers (for example, polyester fibers, polyamide fibers, etc.) may be used as the material for the insulating member.

  The material of the conductive member (for example, the front side electrode FXa, the back side electrode FYa, the front side wiring Fx, the back side wiring Fy, the front side ground electrode 240, the back side ground electrode 241 and the like) is not particularly limited. What is necessary is just to have the softness | flexibility of the grade which curves with the weight of the person M. For example, an electrode material in which a conductive filler is contained in an elastomer as a base material may be used. In this case, the elastomer includes silicone rubber, ethylene-propylene copolymer rubber, natural rubber, styrene-butadiene copolymer rubber, acrylonitrile-butadiene copolymer rubber, acrylic rubber, epichlorohydrin rubber, chlorosulfonated polyethylene, chlorinated polyethylene. Urethane rubber or the like can be used. Moreover, as an electroconductive filler, what consists of 1 or more types chosen from a carbon material and a metal can be used. As the metal, highly conductive silver, copper, or the like is preferable. For example, as the conductive filler, fine particles such as silver and copper, or fine particles having a surface plated with silver or the like can be used. Carbon materials have good conductivity and are relatively inexpensive. For this reason, when the conductive filler made of a carbon material is used, the manufacturing cost of the capacitive sensor 1 can be reduced. As the carbon material, for example, conductive carbon black, carbon nanotubes, carbon nanotube derivatives, graphite, conductive carbon fibers, and the like can be used. In particular, conductive carbon black, graphite, and conductive carbon fiber have good conductivity and are relatively inexpensive. For this reason, when these materials are used, the manufacturing cost of the capacitive sensor 1 can be reduced. Moreover, you may use the woven fabric of a conductive fiber, a nonwoven fabric, etc. as a material of the member which has electroconductivity.

  The capacitive sensor of the present invention may be embodied as a mutual capacitive touch sensor. In this case, one of the front-side electrode portion FX and the back-side electrode portion FY may be set as the reception electrode and the other as the transmission electrode.

1: Capacitance type sensor 20F: Connector, 21F: Harness, 22F: Control device, 23: Cover, 220: Power supply, 221: Input side switching circuit, 222: Output side switching circuit, 223: Capacitance detection unit, 230: Cover hole, 240: Front side ground electrode, 241: Back side ground electrode (ground electrode), 250: Front side insulating spacer, 251: Back side insulating spacer (insulating spacer), 251b: Restraint part, 251c: Non-restraint part, 251d: First film, 251e: second film, 260: front substrate, 261: back substrate, 262: back substrate, 270: front cover coat, 271: back cover coat, 280: dielectric layer, 281: reinforcement layer 293: Overall connection part, 294: Strip-like connection part, 295: Spot-like connection part 8: Positioning hole 9: Sheet CF: Detection part, D1: Hole diameter, D2 : Hole diameter, F: sensor part, FX: front side electrode part (input side electrode part), FXa: front side electrode, FY: back side electrode part (output side electrode part), FYa: back side electrode, Fx: front side wiring, Fy: back side Wiring, M: Person

Claims (11)

A sensor unit having a front side electrode unit, a back side electrode unit disposed on the back side of the front side electrode unit, and a dielectric layer disposed between the front side electrode unit and the back side electrode unit;
An insulating spacer composed of a plurality of insulating films disposed on at least one of the front side and the back side of the sensor unit and stacked in the front and back direction;
A plurality of the insulating films partially connected to each other, and a plurality of spot-like connecting portions arranged in a dot pattern when viewed from the front side or the back side;
An earth electrode disposed on the outer side in the front and back direction of the insulating spacer and grounded;
A controller that is electrically connected to the sensor unit, applies a voltage to the sensor unit, and transmits an electrical quantity related to the capacitance of the sensor unit;
A capacitive sensor comprising:   The capacitive sensor according to claim 1, wherein the three adjacent spot-like connecting portions are arranged at the apexes of an equilateral triangle when viewed from the front side or the back side.   2. The capacitive sensor according to claim 1, wherein the plurality of spot-like connecting portions are arranged at intersections of orthogonal lattices when viewed from the front side or the back side.   4. The total area of the plurality of spot-like connecting portions is set to 0.5% or more and 50% or less, where the area of the front or back surface of the insulating spacer is 100%. 5. Capacitance type sensor. In the insulating spacer, the surface of the insulating film laminated on the most front side is the outer surface, the back surface of the insulating film laminated on the most back side is the outer back surface,
Of the pair of insulating films adjacent to each other in the stacking direction, the back surface of the insulating film on the front side is the inner back surface, and the surface of the insulating film on the back side is the inner surface.
5. The capacitance type sensor according to claim 1, wherein a friction coefficient of at least one of the inner back surface and the inner surface is smaller than a friction coefficient of the outer surface and the outer back surface. The plurality of insulating films have a first film and a second film,
The capacitive sensor according to claim 5, wherein a friction coefficient of both front and back surfaces of the second film is smaller than a friction coefficient of both front and back surfaces of the first film.   In the insulating spacer, the insulating film laminated on the most front side and the insulating film laminated on the most back side are the first film, and the insulating film laminated between a pair of the first films is The capacitive sensor according to claim 6, which is a second film. The first film is made of polyethylene containing no slip agent,
The capacitive sensor according to claim 6 or 7, wherein the second film is made of polyethylene containing a slip agent.   The capacitive sensor according to claim 1, wherein the sensor unit is disposed on the back side of the surface of the bedding. Of the front-side electrode part and the back-side electrode part, one is an input-side electrode part to which the voltage is applied from the control device, and the other is an output-side electrode part that transmits the amount of electricity to the control device,
The capacitive sensor according to any one of claims 1 to 9, wherein the output side electrode portion is disposed closer to the ground electrode than the input side electrode portion. A positioning hole penetrating the sensor part, the insulating spacer, and the ground electrode in the front and back direction; and
A bag-like cover for housing the sensor unit, the insulating spacer, and the ground electrode;
With
The capacitive sensor according to any one of claims 1 to 10, wherein both front and back layers of the cover are joined on the radially inner side of the positioning hole.

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