JP2017198473A - Pressure sensitive sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pressure sensitive sensor capable of properly detecting pressure.SOLUTION: A pressure sensitive sensor 1 is equipped with: a first electrode sheet 10 which has a first electrode 12; a second electrode sheet 20 which has a second electrode 22 opposing to the first electrode 12; a spacer 30 which is interposed between the first electrode sheet 10 and the second electrode sheet 20, and has a first opening portion 31 between the first electrode 12 and the second electrode 22; and a reinforcing sheet 40 which is disposed on the opposite surface side to a surface on the spacer 30 side of the first electrode sheet 10, and has stiffness larger than that of the first electrode sheet 10. The reinforcing sheet 40 has an outside part 40A disposed on the outer side than a position overlapped with an opening edge of the first opening portion 31 in a direction orthogonal to a surface of the first electrode sheet 10, an inside part 40 disposed on an inner side than the position, rand a second opening portion 41 overlapped with at least a center of the first opening portion 31 on the inner side of the inside part 40B.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a pressure sensitive sensor.

  As one of safety systems in vehicles, an alarm system for warning that a seat belt is not worn when riding is put into practical use. In this alarm system, a warning is issued when the seat belt is not detected while a person is seated. As a device for detecting the seating of the person, a pressure-sensitive sensor that detects a pressure caused by the seating may be used.

  There exists what is described in the following patent document 1 as such a pressure-sensitive sensor. In the pressure-sensitive sensor disclosed in Patent Document 1, a sheet-like spacer is interposed between a pair of resin sheets, and a pair of electrodes formed on the pair of sheets are spaced apart from each other within an opening of the spacer. Facing each other.

  In addition, in the pressure-sensitive sensor of Patent Document 1 below, when a pressure due to seating is applied, the upper sheet, which is the side that mainly receives pressure, of the pair of resin sheets is deformed so as to bend toward the lower sheet. . Due to the deformation of the upper sheet, the electrode formed on the upper sheet comes into contact with the electrode formed on the lower sheet, so that the switch constituted by the pair of electrodes is switched from OFF to ON.

JP 2013-216277 A

  By the way, pressure may be applied to a position shifted from a portion of the upper sheet that is directly above the opening of the spacer. Even in this case, since the resin sheet is easily bent, the upper sheet tends to be deformed toward the lower sheet. Therefore, there is a concern that when a pressure that should not be detected is applied, the switch is turned on and erroneous detection is performed.

  Then, an object of this invention is to provide the pressure sensor which can detect a pressure appropriately.

  In order to solve the above problems, a pressure sensor of the present invention includes a first electrode sheet having a first electrode, a second electrode sheet having a second electrode facing the first electrode, the first electrode sheet, A spacer interposed between the second electrode sheets and having a first opening between the first electrode and the second electrode; and a surface side of the first electrode sheet opposite to the surface on the spacer side A reinforcing sheet having a rigidity higher than that of the first electrode sheet, wherein the reinforcing sheet overlaps with an opening edge of the first opening in a direction perpendicular to the surface of the first electrode sheet. An outer portion disposed on the outer side, an inner portion disposed on the inner side from a position overlapping the opening edge of the first opening, and a second inner portion overlapping at least the center of the first opening. And having an opening To.

In this pressure-sensitive sensor, when pressure is applied to the first electrode sheet from the surface of the reinforcing sheet on the side opposite to the surface on the first electrode sheet side, the pressure is applied to the first electrode sheet. Accordingly, the first electrode sheet bends toward the second electrode sheet. As a result, the first electrode and the second electrode separated by the spacer come into contact with each other through the first opening of the spacer, and the switch constituted by the electrode is switched from OFF to ON.
Here, when pressure is applied to a position shifted from a portion directly above the second opening of the reinforcing sheet, the first electrode sheet does not receive pressure through the second opening of the reinforcing sheet, but the reinforcing sheet It will receive pressure. Since the reinforcing sheet has higher rigidity than the first electrode sheet, it is difficult to bend. Therefore, when the reinforcing sheet receives pressure deviating from the portion directly above the second opening of the reinforcing sheet, the first electrode sheet in the second opening of the reinforcing sheet is bent toward the second electrode sheet. This can be suppressed. As a result, the switch is switched from OFF to ON due to the pressure being applied to the position shifted from the portion directly above the second opening of the reinforcing sheet, and erroneous detection is suppressed.
Thus, the pressure-sensitive sensor of the present invention can appropriately detect the pressure.

  By the way, it is preferable that the inner portion is not bonded to the first electrode sheet.

  Since the inner part is not bonded to the first electrode sheet, when pressure is applied from a part directly above the second opening of the reinforcing sheet, the first electrode sheet located below the inner part is It can be flexibly bent toward the two-electrode sheet. Therefore, the pressure at which the switch should be switched from OFF to ON can be detected more accurately than when the inner portion is bonded to the first electrode sheet.

  The length of the inner portion from the opening edge of the first opening to the second opening is preferably longer than the interelectrode distance between the first electrode and the second electrode.

  In this case, the switch is turned off when pressure is applied to a position shifted from the portion directly above the second opening of the reinforcing sheet, compared to the case where the length of the inner portion is shorter than the distance between the electrodes. It is suppressed that the pressure of the grade which switches from ON to ON is applied to the first electrode sheet. Therefore, the pressure can be detected more appropriately.

  In addition, the outer shape of the first opening and the second opening is circular, and the central axis of the second opening coincides with the central axis of the first opening. It is preferable to be provided.

  Compared with the case where the second opening is provided in a state where the central axis of the second opening of the reinforcing sheet smaller than the first opening of the spacer is shifted from the central axis of the first opening of the spacer, the switch is turned off. The pressure to be switched on can be detected more accurately.

  The reinforcing sheet is preferably made of metal.

  Since there is little influence of heat on the reinforcing sheet, even if the pressure sensor is used in a high temperature environment or a low temperature environment, the sensitivity of the pressure sensor is stabilized. In addition, since the reinforcing sheet is made of metal, it is possible to reduce damage caused by pressure applied to a position shifted from the portion directly above the second opening of the reinforcing sheet, and to improve durability.

  In addition, such a pressure-sensitive sensor can be arrange | positioned under the elastic member, and the said elastic member can also be made to be a seat cushion.

  As described above, according to the present invention, a pressure-sensitive sensor capable of appropriately detecting pressure is provided.

It is an exploded view which shows the pressure sensor in this embodiment. It is sectional drawing of the pressure sensitive sensor in this embodiment. It is the figure which planarly viewed the pressure sensitive sensor from the reinforcement sheet side. It is a figure which shows a mode that the pressure-sensitive sensor of this embodiment was attached to the seat apparatus. It is sectional drawing which shows a mode that a pressure-sensitive sensor turns on.

(1) Embodiment Hereinafter, a preferred embodiment of a pressure-sensitive sensor according to the present invention will be described in detail with reference to the drawings. For ease of understanding, the scale of each figure may be different from the scale described in the following description.

  FIG. 1 is an exploded view of a pressure sensitive sensor in the present embodiment, and FIG. 2 is a cross-sectional view of the pressure sensitive sensor in the present embodiment. As shown in FIGS. 1 and 2, the pressure-sensitive sensor 1 includes a first electrode sheet 10, a second electrode sheet 20, a spacer 30, and a reinforcing sheet 40 as main components.

  The first electrode sheet 10 includes a first insulating sheet 11, a first electrode 12, and a terminal 13.

  The first insulating sheet 11 is a film-like insulating sheet having flexibility. Examples of the material of the first insulating sheet 11 include resins such as polyethylene terephthalate (PET), polyimide (PI), and polyethylene naphthalate (PEN). The first insulating sheet 11 of the present embodiment includes a rectangular main block 11a in which the first electrode 12 is disposed and a rectangular sub-block 11b in which the terminal 13 is disposed. The sub block 11b is smaller than the main block 11a and is connected to an end portion in the longitudinal direction of the main block 11a.

  The first electrode 12 is one switch element that forms a switch, and is disposed on one surface of the main block 11a. The first electrode 12 of the present embodiment is a substantially circular metal print layer.

  The terminal 13 is one terminal element connected to an electronic circuit outside the pressure-sensitive sensor 1, and is disposed on one surface of the sub-block 11b on the same side as the surface on which the first electrode 12 is disposed. . The terminal 13 is electrically connected to the first electrode 12 through the first wiring 14. The terminal 13 of this embodiment is a substantially rectangular metal layer.

  Similar to the first electrode sheet 10, the second electrode sheet 20 includes a second insulating sheet 21, a second electrode 22, and a terminal 23.

  The second insulating sheet 21 is a flexible film-like insulating sheet. As the material of the second insulating sheet 21, as in the first insulating sheet 11, resins such as PET, PI, PEN, and the like can be given. The material of the second insulating sheet 21 may be the same as or different from the material of the first insulating sheet 11. The second insulating sheet 21 of the present embodiment includes a main block 21a in which the second electrode 22 is disposed and a sub-block 21b in which the terminal 23 is disposed. The main block 21a has the same shape and size as the main block 11a of the first insulating sheet 11, and the sub block 21b has the same shape and size as the sub block 11b of the first insulating sheet 11. The connection position of the sub block 21b connected to the main block 21a is a position relatively different from the connection position of the sub block 11b connected to the main block 11a of the first insulating sheet 11.

  The second electrode 22 is the other switch element that forms a switch, and is disposed on one surface of the main block 21a. The arrangement position of the second electrode 22 with respect to the main block 21a and the arrangement position of the first electrode 12 with respect to the main block 11a are relatively the same position. The second electrode 22 of the present embodiment is a metal printing layer having the same shape and size as the first electrode 12.

  The terminal 23 is the other terminal element connected to an electronic circuit outside the pressure sensor 1, and is disposed on one surface of the sub-block 21b on the same side as the surface on which the second electrode 22 is disposed. . The terminal 13 is electrically connected to the second electrode 22 through the second wiring 24. The terminal 23 of the present embodiment is a metal layer having the same shape and size as the terminal 13.

  The spacer 30 is a film-like insulating sheet and is interposed between the first electrode sheet 10 and the second electrode sheet 20. The spacer 30 of the present embodiment has the same shape and size as the main block 11 a of the first insulating sheet 11 and the main block 21 a of the second insulating sheet 21. Examples of the material of the spacer 30 include resins such as PET, PI, and PEN, similarly to the first insulating sheet 11 and the second insulating sheet 21. The material of the spacer 30 may be the same as or different from the material of the first insulating sheet 11 or the second insulating sheet 21.

  The spacer 30 has a first opening 31 that penetrates from one surface of the spacer 30 to the other surface. The peripheral shape (outer shape) of the first opening 31 of the present embodiment is substantially circular, and the diameter of the first opening 31 is slightly smaller than the diameters of the first electrode 12 and the second electrode 22. The arrangement position of the first opening 31 with respect to the spacer 30, the arrangement position of the first electrode 12 with respect to the main block 11a, and the arrangement position of the second electrode 22 with respect to the main block 21a are relatively the same position.

  The first electrode sheet 10 is attached to one surface of the spacer 30, and the second electrode sheet 20 is attached to the other surface of the spacer 30. The spacer 30 and the first electrode sheet 10 and the second electrode sheet 20 are attached by the same adhesive layer as the adhesive layer 50 (FIG. 2), but for convenience, the adhesive layer is omitted in FIG. .

  The reinforcing sheet 40 is a metal sheet having a rigidity higher than that of the first electrode sheet 10, and is disposed on the surface side of the first electrode sheet 10 opposite to the surface on the spacer 30 side. Examples of the metal material include copper, stainless steel, and alloys. The reinforcing sheet 40 of the present embodiment has the same shape and size as the spacer 30.

  FIG. 3 is a plan view of the pressure sensor from the reinforcing sheet side. As shown in FIG. 3, the reinforcing sheet 40 is disposed outside the position P that overlaps the opening edge of the first opening 31 of the spacer 30 in the direction orthogonal to the surface of the first insulating sheet 11 in the first electrode sheet 10. An outer portion 40A and an inner portion 40B disposed on the inner side from the position P. In FIG. 3, for easy understanding, the outer portion 40A is indicated by a diagonal line from the upper left to the lower right, and the inner portion 40B is indicated by an oblique line from the upper right to the lower left of the paper. In this embodiment, since the first opening 31 of the spacer 30 is circular, the position P is circular.

  The outer portion 40A is bonded to the first electrode sheet 10 by the adhesive layer 50 (FIG. 2), and the inner portion 40B is not bonded to the first electrode sheet 10. The adhesive layer 50 is a layered member that bonds the first electrode sheet 10 and the reinforcing sheet 40 together. In the present embodiment, the adhesive layer 50 has the same size as the outer portion 40 </ b> A of the reinforcing sheet 40. The material of the adhesive layer 50 may be any material as long as the first electrode sheet 10 and the reinforcing sheet 40 can be bonded together. For example, a thermoplastic resin, a thermosetting resin, a photo-curing resin, or the like Is mentioned. The glass transition point Tg of the adhesive layer 50 is preferably 85 ° C. or higher. Since the glass transition point Tg is 85 ° C. or higher, it is difficult for the glass transition point Tg to flow even in an environment where the temperature is high, such as the interior of a car under hot weather. Therefore, the first electrode sheet 10 and the reinforcing sheet are caused by the flow of the adhesive layer 50. It can suppress that the position with 40 changes relatively.

  Further, the reinforcing sheet 40 has a second opening 41 that is inside the inner portion 40 </ b> B and overlaps the center of the first opening 31 of the spacer 30. The second opening 41 is directed toward the position P on the basis of a central axis AX1 (FIG. 2) that passes through the center of the first opening 31 of the spacer 30 and extends in a direction orthogonal to the surface of the first electrode sheet 10. It is open. The second opening 41 penetrates the reinforcing sheet 40 from one surface of the reinforcing sheet 40 to the other surface, has the same shape as the first opening 31 of the spacer 30, and the first opening 31. Is made smaller.

  In the present embodiment, the second opening 41 of the reinforcing sheet 40 and the first opening 31 of the spacer 30 are both cylindrical and have a circular outer shape, and the second opening 41 is the first opening. The central axis AX2 (FIG. 2) of the second opening 41 is provided so as to coincide with the central axis AX1 (FIG. 2) of the portion 31.

  Further, the length D1 of the inner portion 40B, which is a linear distance from the position P to the second opening 41, is shorter than the radius D2 (FIG. 2) of the first opening 31 of the spacer 30, and the first electrode 12 and the first opening It is made longer than the distance D3 (FIG. 2) between the two electrodes 22.

  Next, an example of mounting the pressure sensor 1 will be described. FIG. 4 is a diagram illustrating a state in which the pressure-sensitive sensor according to the present embodiment is attached to the seat device. In FIG. 4, the pressure sensor 1 is shown in a simplified manner for convenience.

  As shown in FIG. 4, a seat cushion 70 that is an elastic member is placed on a plurality of springs 60 that are stretched over openings in a frame (not shown), and two adjacent ones of the plurality of springs 60. The pressure sensitive sensor 1 is placed on a pedestal 80 attached to a part of the spring 60.

  That is, in the example shown in FIG. 4, the pressure-sensitive sensor 1 is supported by the spring 60 via the pedestal 80, and is disposed between the adjacent springs 60 with a gap from the lower surface of the seat cushion 70 that is an elastic member. For this reason, the pressure-sensitive sensor 1 disposed below the seat cushion 70 that is an elastic member is in a state in which no pressure is applied by the seat cushion 70. In this state, the first electrode 12 and the second electrode 22 constituting the switch SW of the pressure sensor 1 are opposed to each other with the first opening 31 of the spacer 30 being separated.

  When a person sits on the seat cushion 70, the lower surface of the seat cushion 70 falls between adjacent springs and comes into contact with the pressure sensor 1, and pressure is applied from the seat cushion 70 to the pressure sensor 1. The pressure distribution applied from the seat cushion 70 to the pressure-sensitive sensor 1 in response to the seating is greatest at a portion of the pressure-sensitive sensor 1 that is directly above the second opening 41 of the reinforcing sheet 40.

  FIG. 5 is a cross-sectional view showing how the pressure sensor is turned on. As shown in FIG. 5, when the pressure of the pressure distribution that becomes the largest at the portion directly above the second opening 41 of the reinforcing sheet 40 is applied to the pressure sensor 1, the reinforcing sheet 40 of the pressure sensor 1 is made of metal. Because there is, it hardly bends.

  On the other hand, the seat cushion 70 enters the second opening 41 of the reinforcing sheet 40 and presses the first electrode sheet 10 below the reinforcing sheet 40, and pressure is applied to the first electrode sheet 10 from the seat cushion 70. Since the first electrode sheet 10 has flexibility, it bends toward the second electrode sheet 20 in accordance with the pressure applied from the seat cushion 70. As a result, the first electrode 12 and the second electrode 22 separated by the spacer 30 come into contact with each other through the first opening 31 of the spacer 30, and the switch SW is switched from off to on.

  By the way, when a load or the like is placed on the seat cushion 70, there is a tendency that the pressure of the pressure distribution that becomes the largest at a portion shifted from the portion directly above the second opening 41 of the reinforcing sheet 40 is applied to the pressure sensor 1. In this case, since the reinforcing sheet 40 is made of metal, it hardly bends. In addition, the second opening 41 of the reinforcing sheet 40 is smaller than the first opening 31 of the spacer 30, and the seat cushion 70 is The entry into the two openings 41 is suppressed.

  Note that the length D1 of the inner portion 40B, which is a linear distance from the position P to the second opening 41, is longer than the inter-electrode distance D3 (FIG. 2) between the first electrode 12 and the second electrode 22. For this reason, even if the seat cushion 70 enters the second opening 41, it is possible to suppress the pressure applied to the first electrode sheet 10 from the seat cushion 70 so that the switch SW is switched from OFF to ON.

  As described above, in the pressure-sensitive sensor 1 of the present embodiment, the reinforcing sheet 40 made of a metal having higher rigidity than the resin is provided on the surface of the first electrode sheet 10 made of resin opposite to the surface on the spacer 30 side. Is provided.

  The reinforcing sheet 40 is an outer portion that is disposed outside from a position P that overlaps the opening edge of the first opening 31 of the spacer 30 in a direction orthogonal to the surface of the first electrode sheet 10 when the reinforcing sheet 40 is viewed in plan. 40A and an inner portion 40B disposed on the inner side from the position P. Further, the reinforcing sheet 40 has a second opening 41 that is inside the inner portion 40 </ b> B and overlaps the center of the first opening 31 of the spacer 30.

  As described above, when pressure is applied to a position shifted from the portion of the reinforcing sheet 40 that is directly above the second opening 41, the first electrode sheet 10 receives pressure through the second opening 41 of the reinforcing sheet 40. Instead, the reinforcing sheet 40 receives pressure. Since the reinforcing sheet 40 has higher rigidity than the first electrode sheet 10, it is difficult to bend. Therefore, when the reinforcing sheet 40 receives pressure deviating from the portion directly above the second opening 41 of the reinforcing sheet 40, the first electrode sheet 10 in the second opening 41 of the reinforcing sheet 40 is the second electrode sheet. It can suppress that it curves toward. As a result, the switch SW is switched from OFF to ON and erroneous detection is suppressed due to the pressure being applied to the position shifted from the portion directly above the second opening 41 of the reinforcing sheet 40.

  Thus, the pressure-sensitive sensor 1 of the present embodiment can appropriately detect the pressure. In addition, since the 2nd opening part 41 of the reinforcement sheet 40 is smaller than the 1st opening part 31 of the spacer 30, the range which receives the pressure which switch SW should switch from OFF can be determined more correctly.

  By the way, in the case of this embodiment, the inner side part 40B in the reinforcing sheet 40 is not bonded to the first electrode sheet 10.

  Since the inner portion 40B is not bonded to the first electrode sheet 10, when pressure is applied from a portion directly above the second opening 41 of the reinforcing sheet 40, the inner portion 40B is located below the inner portion 40B. The 1 electrode sheet 10 can be flexed flexibly toward the second electrode sheet. Therefore, the pressure at which the switch SW should be switched from OFF to ON can be detected more accurately than when the inner portion 40B is bonded to the first electrode sheet 10.

  In the case of the present embodiment, when the reinforcing sheet 40 is viewed in plan, the length of the inner portion 40B from the position P that overlaps the opening edge of the first opening 31 of the spacer 30 to the second opening 41 in the reinforcing sheet 40. D1 is longer than the interelectrode distance D3 between the first electrode 12 and the second electrode 22.

  Compared to the case where the length D1 of the inner portion 40B is shorter than the inter-electrode distance D3, when pressure is applied to a position shifted from the portion directly above the second opening 41 of the reinforcing sheet 40, the seat cushion It is suppressed that the pressure which the switch SW is switched from OFF to ON from 70 is applied to the first electrode sheet 10. Therefore, the pressure can be detected more appropriately.

  In the case of this embodiment, the outer shape of the second opening 41 of the reinforcing sheet 40 and the first opening 31 of the spacer 30 is circular, and the second opening 41 is the central axis AX1 of the first opening 31. In contrast, the central axis AX2 of the second opening 41 is provided to coincide.

  For this reason, the second opening 41 is in a state in which the central axis AX2 of the second opening 41 of the reinforcing sheet 40 smaller than the first opening 31 is displaced from the central axis AX1 of the first opening 31 of the spacer 30. Compared with the case where it arrange | positions, the pressure which switch SW should switch from OFF to ON can be detected more correctly.

  In the present embodiment, the reinforcing sheet 40 is made of metal. For this reason, since there is little influence by the heat | fever in the reinforcement sheet | seat 40, even if the pressure sensor 1 is used in high temperature environment or a low temperature environment, the sensitivity of the said pressure sensor 1 is stabilized. Moreover, the breakage | damage etc. of the said reinforcement sheet 40 resulting from the pressure given to the position which shifted | deviated from the site | part which directly hits the 2nd opening part 41 of the reinforcement sheet 40 can be reduced, and durability can be improved.

(2) Modified Example Although the present embodiment has been described as an example, the present invention is not limited to the above embodiment.

  For example, in the above embodiment, the reinforcing sheet 40 is made of metal, and the rigidity of the reinforcing sheet 40 is made larger than that of the first electrode sheet 10 made of resin. However, for example, a reinforcing sheet made of the same resin as that of the first electrode sheet 10 is employed, and the thickness of the reinforcing sheet is made larger than the thickness of the first electrode sheet 10, thereby reinforcing the first electrode sheet 10. The rigidity of the sheet may be increased. As another example, a reinforcing sheet made of a resin having higher rigidity than the first electrode sheet 10 may be employed. Examples of the resin material having higher rigidity than the first electrode sheet 10 include polycarbonate, polyamide, polybutylene terephthalate, phenol resin, and epoxy resin. Moreover, although the reinforcement sheet 40 was one layer, you may be made into two or more layers. In short, any reinforcing sheet having higher rigidity than the first electrode sheet 10 may be used.

  In the above embodiment, the outer shape of the second opening 41 in the reinforcing sheet 40 is the same circle as the first opening 31 of the spacer 30. However, the outer shape of the second opening 41 may be different from that of the first opening 31 of the spacer 30, and a shape other than a circle may be adopted.

  In the above-described embodiment, the second opening 41 of the reinforcing sheet 40 is disposed in a state where the central axis AX2 of the second opening 41 of the reinforcing sheet 40 coincides with the central axis AX1 of the first opening 31 of the spacer 30. It was done. However, even if the second opening 41 of the reinforcing sheet 40 is arranged in a state where the central axis AX2 of the second opening 41 of the reinforcing sheet 40 is shifted from the central axis AX1 of the first opening 31 of the spacer 30. good. However, as described above, in order to more accurately detect the pressure at which the switch SW should be switched from OFF to ON, the central axis AX2 of the second opening 41 coincides with the central axis AX1 of the first opening 31. In the state, the second opening 41 of the reinforcing sheet 40 is preferably disposed.

  Moreover, in the said embodiment, the whole outer side part 40A of the reinforcement sheet 40 was fixed by adhere | attaching with the 1st electrode sheet 10 with the contact bonding layer 50 (FIG. 2). However, a part of the outer portion 40A of the reinforcing sheet 40 may be bonded to the first electrode sheet 10 by the adhesive layer 50 (FIG. 2). Further, the outer portion 40 </ b> A of the reinforcing sheet 40 and the first electrode sheet 10 may be fixed by a member other than the adhesive layer 50. Further, for example, if there is a member that regulates the relative displacement between the outer portion 40A and the first electrode sheet 10 such as a pin that penetrates the outer portion 40A and the first electrode sheet 10, the outer portion 40A and the 1st electrode sheet 10 do not need to be fixed.

  In the above embodiment, the inner portion 40B of the reinforcing sheet 40 is not bonded. However, the inner portion 40B may be fixed by the adhesive layer 50 or other members. However, as described above, when pressure is applied from a portion directly above the second opening 41 of the reinforcing sheet 40, the first electrode sheet 10 in the second opening 41 is directed toward the second electrode sheet. In order to bend flexibly, it is preferable that the inner portion 40B is not bonded.

  In the above embodiment, the length D1 of the inner portion 40B, which is the linear distance from the position P to the second opening 41, is shorter than the radius D2 of the first opening 31 of the spacer 30, and the first electrode 12 and the second electrode The second opening 41 was provided so as to be longer than the interelectrode distance D3 with the electrode 22. However, when the reinforcing sheet 40 is viewed in plan, the reinforcing sheet 40 has a second opening that overlaps at least the opening edge of the first opening 31 of the spacer 30 inside the inner portion 40B of the reinforcing sheet 40. If so, various conditions such as the length D1 and the shape of the inner portion 40B are not limited to the above embodiment.

  Moreover, in the said embodiment, the 2nd electrode 22 was comprised by one conductor layer. However, the second electrode is composed of the first comb-shaped electrode piece and the second tooth-shaped electrode piece disposed so as to mesh with the first comb-shaped electrode piece with a gap. It may be configured.

  The constituent elements of the pressure sensor 1 described above may be appropriately combined, omitted, changed, or added with a well-known technique within the scope not departing from the purpose of the present application, in addition to the contents shown in the above-described embodiments and modifications. it can.

  The present invention can be used as long as the pressure from the detection object is detected. That is, in the above-described embodiment, the pressure-sensitive sensor 1 is disposed below the seat cushion 70 of the vehicle, and the pressure-sensitive sensor 1 detects the pressure caused by the seating of the person. However, the present invention is not limited to the above-described embodiment. It can be adopted. For example, the form which arrange | positions the pressure-sensitive sensor 1 under the seat cushion of a nursing bed is mentioned. Even if it is such a form, it can show whether the person exists in a seat cushion using the pressure-sensitive sensor 1. FIG. An elastic member other than the seat cushion 70 may be employed instead of the seat cushion 70. That is, the pressure-sensitive sensor 1 may be provided below an elastic member other than the seat cushion 70. As the elastic member, any material may be used as long as it has an elastic force and can transmit the pressure from the detection target to the pressure-sensitive sensor 1, but examples of the material of the elastic member include urethane, silicon, And ethylene propylene. Moreover, the pressure-sensitive sensor 1 of this invention does not need to be arrange | positioned under elastic members, such as a seat cushion. The present invention can also be used to detect the pressure applied when the pressure sensor 1 is arranged as a part of a switch of an electronic device or the like and the switch is pressed with a human finger or the like.

DESCRIPTION OF SYMBOLS 1 ... Pressure sensor 10 ... 1st electrode sheet 11 ... 1st insulating sheet 12 ... 1st electrode 13,23 ... Terminal 20 ... 2nd electrode sheet 21 ... 1st 2 insulating sheet 22 ... 2nd electrode 30 ... spacer 31 ... 1st opening part 40 ... reinforcement sheet 40A ... outside part 40B ... inside part 41 ... 2nd opening part 50 ... Adhesive layer SW ... Switch

Claims (7)

A first electrode sheet having a first electrode;
A second electrode sheet having a second electrode facing the first electrode;
A spacer interposed between the first electrode sheet and the second electrode sheet and having a first opening between the first electrode and the second electrode;
A reinforcing sheet disposed on the opposite side of the spacer side surface of the first electrode sheet and having a rigidity higher than that of the first electrode sheet;
With
The reinforcing sheet includes an outer portion disposed on the outer side from a position overlapping the opening edge of the first opening in a direction orthogonal to the surface of the first electrode sheet, and a position overlapping the opening edge of the first opening. A pressure-sensitive sensor, comprising: an inner part disposed inside; and a second opening that is at least inside the inner part and overlaps at least the center of the first opening. The pressure-sensitive sensor according to claim 1, wherein the inner portion is not bonded to the first electrode sheet. The length of the inner part from the opening edge of the first opening to the second opening is longer than the inter-electrode distance between the first electrode and the second electrode. 2. The pressure-sensitive sensor according to 2. The outer shapes of the first opening and the second opening are circular,
The said 2nd opening part is provided so that the center axis | shaft of the said 2nd opening part may correspond with the center axis | shaft of the said 1st opening part. Pressure sensor. The pressure sensor according to any one of claims 1 to 4, wherein the reinforcing sheet is made of metal. The pressure-sensitive sensor according to any one of claims 1 to 5, wherein the pressure-sensitive sensor is disposed below the elastic member. The pressure-sensitive sensor according to claim 6, wherein the elastic member is a seat cushion.

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