JP7589415B2 - Sensor device and vehicle seat - Google Patents

Description

The present invention relates to a sensor device and a vehicle seat.

The following Patent Document 1 discloses a sensor device installed in a vehicle seat, in which a sheet-like electrode and a wiring pattern on a circuit board are connected by soldering.

International Publication No. 2019/116919

However, because the sensor device in Patent Document 1 is incorporated into a vehicle seat, when a user sits in the vehicle seat, there is a possibility that a large load will be applied to the soldered connection between the sheet-like electrode and the wiring pattern on the board, and the connection must be designed to prevent breakage even in such a case.

The sensor device according to one embodiment includes an insulating sheet-like substrate, a sheet-like first electrode that is overlaid on a first surface of the substrate and adhered to the first surface by a first adhesive means, and a flexible substrate that is overlaid on the first surface of the substrate, the first electrode having a non-adhesive area that is not adhered to the first surface in a portion that overlaps with the first surface of the substrate, the flexible substrate having an extension that extends to a position that overlaps with the non-adhesive area of the first electrode, and the extension has a first contact portion that is in non-fixed contact with the non-adhesive area in the portion that overlaps with the non-adhesive area of the first electrode.

According to one embodiment of the sensor device, when a large load is applied to the connection between the sheet-like electrode and the wiring pattern of the flexible substrate, damage to the connection can be suppressed.

FIG. 1 is an external perspective view of a vehicle seat according to an embodiment; FIG. 1 is an exploded perspective view of a sensor device according to an embodiment; 1 is a cross-sectional view of a sensor device according to an embodiment; FIG. 13 is an exploded perspective view of a sensor device according to a modified example of an embodiment.

One embodiment of the present invention will be described below with reference to the drawings.

(Configuration of the vehicle seat 10)
Fig. 1 is an external perspective view of a vehicle seat 10 according to one embodiment. As shown in Fig. 1, the vehicle seat 10 includes a backrest portion 11 and a seat portion 12. Each of the backrest portion 11 and the seat portion 12 has a plurality of sensor devices 100 on the inside of the surface. Each of the plurality of sensor devices 100 can detect an electrical signal emitted by the body of a user seated in the vehicle seat 10.

(Configuration of sensor device 100)
Fig. 2 is an exploded perspective view of the sensor device 100 according to one embodiment. Fig. 3 is a cross-sectional view of the sensor device 100 according to one embodiment, taken along a plane passing through the center of the through-hole 111 on the XY plane in Fig. 2 and parallel to the XZ plane.

As shown in Figures 2 and 3, the sensor device 100 according to one embodiment includes a substrate 110, a sensor electrode 120, a shield electrode 130, and a flexible substrate 140.

The substrate 110 is a sheet-like member that is insulating and flexible. A through hole 111 is provided in the center of the substrate 110. The through hole 111 has a circular shape in a plan view. In this embodiment, the substrate 110 is made of nonwoven fabric, an example of a "sheet-like member." The nonwoven fabric is a sheet-like member in which insulating fibers are entangled and stretched out in a plane. The nonwoven fabric is made of synthetic fibers such as polyester and polyethylene.

The sensor electrode 120 is a sheet-like electrode having electrical conductivity that is provided over the second surface 110B (the surface on the positive side of the Z axis) of the substrate 110. The sensor electrode 120 is an example of a "second electrode." The sensor electrode 120 is capable of detecting electrical signals such as electrocardiogram signals emitted by the body of a user seated in the vehicle seat 10 by capacitively coupling with the body of the user.

The shield electrode 130 is a sheet-like electrode having electrical conductivity that is provided over the first surface 110A (the surface on the negative side of the Z axis) of the substrate 110. The shield electrode 130 is an example of a "first electrode." The shield electrode 130 functions as a shield for the surface (the surface on the negative side of the Z axis) of the sensor electrode 120 opposite to the surface facing the body, and is provided to prevent the effects of capacitive coupling with an object located on the opposite side of the surface of the sensor electrode 120 facing the body and noise, and to suppress the noise components from being superimposed on the electrical signal detected by the sensor electrode 120.

The top surface 130A (the surface on the positive side of the Z axis) of the shield electrode 130 is attached to the first surface 110A of the substrate 110 by double-sided tape 151 (an example of a "first adhesive means"). However, the double-sided tape 151 has a cutout portion 151A in which a portion of the positive side of the X axis is cut out in a rectangular shape. This forms a rectangular non-adhesive region 131 on the top surface 130A of the shield electrode 130 at a position overlapping with the cutout portion 151A, which is not attached to the first surface 110A of the substrate 110.

In this embodiment, the sensor electrode 120 and the shield electrode 130 use conductive cloth as an example of a "sheet-like electrode." Examples of conductive cloth include cloth material whose surface is coated with a conductive material (e.g., metal, carbon, etc.), and cloth material that contains a conductive material.

The flexible substrate 140 is a flexible sheet-like member that is overlaid on the first surface 110A of the substrate 110. The flexible substrate 140 is a film-like resin substrate that is insulating and flexible, such as a polyimide film, on which a wiring pattern such as copper foil is provided, and on which various electronic components are mounted. The flexible substrate 140 has a base portion 141 and an extension portion 142.

The base 141 is a rectangular portion with its length in the Y-axis direction and its width in the X-axis direction. The base 141 is disposed on the positive side of the X-axis relative to the shield electrode 130. A processing circuit 143 is mounted on the base 141. The processing circuit 143 drives the sensor electrode 120 and the shield electrode 130, and amplifies electrical signals detected by the sensor electrode 120. The flexible substrate 140 is attached to the first surface 110A of the substrate 110 at the base 141 with double-sided tape 152 (an example of a "second adhesive means").

The extension 142 extends linearly in the positive direction of the X-axis from the middle position of the base 141 in the Y-axis direction to within the cutout 151A of the double-sided tape 151. The tip (end on the negative side of the X-axis) of the extension 142 overlaps with the non-adhesive region 131 of the shield electrode 130 within the cutout 151A of the double-sided tape 151. A first contact 144 and a second contact 145 made of a conductive material are provided at the tip (end on the negative side of the X-axis) of the extension 142.

The first contact portion 144 is provided at the tip of the lower surface 142B (the surface on the negative side of the Z axis) of the extension portion 142. The first contact portion 144 is provided at a position overlapping the through hole 111 of the base material 110 in a plan view, and has a circular shape with a diameter smaller than that of the through hole 111. The first contact portion 144 is provided to protrude slightly downward from the lower surface 142B of the extension portion 142. The first contact portion 144 is disposed in the cutout portion 151A of the double-sided tape 151, so that it faces the non-adhesive region 131 of the shield electrode 130 and is in non-fixed contact with the non-adhesive region 131 of the shield electrode 130. The first contact portion 144 is connected to the processing circuit 143 provided on the base portion 141 via a wiring pattern (not shown) provided on the lower surface 142B of the extension portion 142. The first contact portion 144 is formed by printing a conductive film (e.g., silver paste, carbon, etc.) on the wiring pattern. In this embodiment, the first contact portion 144 is formed separately from the wiring pattern and protrudes slightly downward from the lower surface 142B of the extension portion 142, but the first contact portion 144 may be part of the wiring pattern.

The second contact portion 145 is provided at the tip of the upper surface 142A (the surface on the positive side of the Z axis) of the extension portion 142. The second contact portion 145 is provided at a position overlapping with the through hole 111 of the base material 110 in a plan view, and has a circular shape with a diameter smaller than that of the through hole 111. The second contact portion 145 is provided to protrude slightly upward from the upper surface 142A of the extension portion 142. The second contact portion 145 is disposed in the cutout portion 151A of the double-sided tape 151, so that it faces the lower surface (the surface on the negative side of the Z axis) of the sensor electrode 120 through the through hole 111 of the base material 110, and can contact the lower surface (the surface on the negative side of the Z axis) of the sensor electrode 120. The second contact portion 145 is connected to the processing circuit 143 provided on the base 141 via a wiring pattern (not shown) provided on the upper surface 142A of the extension portion 142. The second contact portion 145 is formed by printing a conductive film (e.g., silver paste, carbon, etc.) on the wiring pattern. In this embodiment, the second contact portion 145 is formed separately from the wiring pattern and protrudes slightly upward from the upper surface 142A of the extension portion 142, but the second contact portion 145 may be part of the wiring pattern.

(Installation example of sensor device 100)
The sensor device 100 according to one embodiment is disposed inside the vehicle seat 10, as shown in Fig. 3. Specifically, the vehicle seat 10 has a seat body 14 formed of urethane or the like, and a seat cover 15 that covers the seat body 14. The sensor device 100 is disposed between the seat body 14 and the seat cover 15 such that the sensor electrode 120 is on the seat cover 15 side, and the shield electrode 130 is on the seat body 14 side.

(Operation of the sensor device 100)
In the sensor device 100 according to one embodiment, when a user is not seated in the vehicle seat 10, the sensor electrode 120 is not in contact with the second contact portion 145 provided on the extension portion 142 of the flexible substrate 140. In addition, the first contact portion 144 provided on the extension portion 142 is in non-fixed contact with the non-adhesive region 131 of the shield electrode 130.

On the other hand, in the sensor device 100 according to one embodiment, when a user sits on the vehicle seat 10, the sensor electrode 120 is pressed by the user, so that the sensor electrode 120 contacts the second contact portion 145 provided on the extension portion 142 of the flexible substrate 140 via the through hole 111 of the base material 110. As a result, the sensor electrode 120 is electrically connected to the wiring pattern provided on the extension portion 142 of the flexible substrate 140. Therefore, the electrical signal detected from the user by the sensor electrode 120 is output to the processing circuit 143 mounted on the base portion 141 of the flexible substrate 140 via the wiring pattern provided on the extension portion 142 of the flexible substrate 140. Then, the electrical signal detected from the user by the sensor electrode 120 is amplified by the processing circuit 143.

At this time, since the extension 142 of the flexible substrate 140 is not fixed to either the sensor electrode 120 or the shield electrode 130, the first contact 144 provided on the extension 142 can move horizontally (in a direction parallel to the XY plane) within the cutout 151A of the double-sided tape 151 while remaining in non-fixed contact with the non-adhesive region 131 of the shield electrode 130. As a result, the sensor device 100 according to one embodiment can release the load applied to the connection between the first contact 144 and the shield electrode 130 by the horizontal movement of the extension 142 when the user sits down, and therefore the connection between the first contact 144 and the shield electrode 130 does not break. Therefore, according to the sensor device 100 according to one embodiment, when a large load is applied to the connection between the sheet-like shield electrode 130 and the wiring pattern of the flexible substrate 140, damage to the connection can be suppressed.

Moreover, in the sensor device 100 according to one embodiment, the flexible substrate 140 has a base 141 and an extension 142 extending from the base 141, and the base 141 is configured to be adhered to the first surface 110A of the substrate 110 by double-sided tape 152.
As a result, the sensor device 100 according to one embodiment can hold the shield electrode 130 and the flexible substrate 140 by the base material 110, and can displace (horizontally move) the extension portion 142 of the flexible substrate 140 relative to the shield electrode 130. In this way, the sensor device 100 according to one embodiment holds the shield electrode 130 and the flexible substrate 140 on the base material 110, and therefore can allow large displacement (horizontally move) of the shield electrode 130 and the flexible substrate 140.

(Modification)
Fig. 4 is an exploded perspective view of a sensor device 100 according to a modified example of an embodiment. The sensor device 100 shown in Fig. 4 includes a flexible substrate 140 having a base portion 141 and an extension portion 142 provided separately, and a connection member 146 that electrically connects the base portion 141 and the extension portion 142. The connection member 146 may be, for example, an electric cable or a flexible substrate.

The base 141 is equipped with a processing circuit 143 that amplifies the electrical signal detected by the sensor electrode 120. The base 141 is attached to the first surface 110A of the substrate 110 with double-sided tape 152.

The extension 142 is provided at a distance in the positive direction of the X-axis from the midpoint of the base 141 in the Y-axis direction, and extends linearly in the positive direction of the X-axis until it reaches the cutout 151A of the double-sided tape 151. The tip of the extension 142, where the first contact 144 and the second contact 145 are provided, is disposed in the cutout 151A of the double-sided tape 151. The extension 142 is not fixed to any member and is movable in the horizontal direction. The electrical signal detected by the sensor electrode 120 is supplied to the processing circuit 143 mounted on the base 141 via the extension 142 and the connection member 146.

In the sensor device 100 according to a modified embodiment, the base 141 and the extension 142 of the flexible substrate 140 are provided separately, so that the base 141 can be fixed to the substrate 110, and the substrate 110 does not interfere with the horizontal movement of the base 141, so that the degree of freedom of horizontal movement of the extension 142 within the cutout 151A of the double-sided tape 151 can be increased.

Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to these embodiments, and various modifications and variations are possible within the scope of the gist of the present invention as described in the claims.

For example, in this embodiment, the sensor electrode 120 and the shield electrode 130 are formed using conductive cloth, but they may each be formed from a flexible substrate. In that case, the surface of the flexible substrate on which the electrodes are formed is arranged to face the flexible substrate 140, so that the sensor electrode 120 or the shield electrode 130 can come into contact with the second contact portion 145 or the first contact portion 144.

The sensor device 100 may also have a protrusion 153 at a position on the seat body 14 or the seat cover 15 that overlaps with the first contact portion 144 and the second contact portion 145 in a plan view.

3, the vehicle seat 10 may have a protrusion 153 on the surface (the surface on the positive side of the Z axis) of the seat body 14 at a position overlapping with the first contact portion 144 in a plan view. This allows the vehicle seat 10 to deform a part of the shield electrode 130 (the contact portion with the first contact portion 144) into a convex shape, thereby making it easier for the part of the shield electrode 130 to come into contact with the first contact portion 144. The protrusion 153 may be formed integrally with the vehicle seat 10, or may be formed separately and integrated by being attached, etc.

Although not shown, for example, the vehicle seat 10 may have a protrusion 153 on the rear surface (the surface on the negative side of the Z axis) of the seat cover 15 at a position overlapping with the second contact portion 145 in a plan view. This allows the vehicle seat 10 to deform a part of the sensor electrode 120 (the contact portion with the second contact portion 145) into a convex shape, thereby making it easier for the part of the sensor electrode 120 to come into contact with the part of the sensor electrode 120. The protrusion 153 may be formed integrally with the seat cover 15, or may be formed separately and integrated by being attached, etc.

For example, the protrusion 153 may be formed by rubber molding, printing, UV resin, etc.

A similar protrusion 153 may be provided at a position on the sensor electrode 120 that overlaps with the second contact portion 145 in a plan view, or at a position on the shield electrode 130 that overlaps with the first contact portion 144 in a plan view. The protrusion 153 may be formed separately and integrated with the sensor electrode 120 or the shield electrode 130 by, for example, attaching it.

In addition, in the sensor device 100, the first contact portion 144 may be provided at a position that does not overlap with the through hole 111 of the substrate 110 in a plan view. This allows the sensor device 100 to prevent the pressing force applied to the first contact portion 144 from being attenuated by the through hole 111, and therefore allows the first contact portion 144 to more reliably contact the shield electrode 130.

In addition, in the sensor device 100, the shield electrode 130 (first electrode) may have a conductive film (e.g., silver paste, carbon, etc.) formed by printing on the contact portion with the first contact portion 144. This allows the sensor device 100 to more reliably bring the shield electrode 130 into contact with the first contact portion 144.

In addition, in the sensor device 100, the sensor electrode 120 (second electrode) may have a conductive film (e.g., silver paste, carbon, etc.) formed by printing or the like on the contact portion with the second contact portion 145. This allows the sensor device 100 to more reliably bring the sensor electrode 120 into contact with the second contact portion 145.

REFERENCE SIGNS LIST 10 Vehicle seat 11 Backrest portion 12 Seat portion 14 Seat body portion 15 Seat cover 100 Sensor device 110 Base material 110A First surface 110B Second surface 111 Through hole 120 Sensor electrode (second electrode)
130 Shield electrode (first electrode)
131 Non-adhesive region 140 Flexible substrate 141 Base 142 Extension 142A Upper surface 142B Lower surface 143 Processing circuit 144 First contact 145 Second contact 146 Connection member 151 Double-sided tape 151A Cutout 152 Double-sided tape 153 Protruding portion

Claims (10)

A sheet-like base material having insulating properties;
a sheet-like first electrode provided on a first surface of the base material and adhered to the first surface by a first adhesive means;
a flexible substrate provided on and overlapping the first surface of the base material;
The first electrode is
a non-adhesive region that is not adhered to the first surface in a portion of the portion of the base material that overlaps the first surface;
The flexible substrate is
an extension portion that extends to a position overlapping the non-adhesive region of the first electrode;
The extension portion is
A sensor device comprising: a first contact portion that is in non-fixed contact with the non-bonded region of the first electrode at a portion that overlaps the non-bonded region. The flexible substrate is
The device has a base and the extension extending from the base,
The sensor device of claim 1 , wherein the base is adhered to the first surface of the substrate by a second adhesive means. The flexible substrate is
a base having a processing circuit thereon;
The extension portion is separate from the base portion;
The sensor device according to claim 1 , further comprising: a connection member that electrically connects the base portion and the extension portion. The electrochemical cell further includes a sheet-like second electrode provided on the second surface of the substrate,
The extension portion is
a second contact portion that is in contact with the second electrode and is disposed in a portion that overlaps the second electrode;
The substrate is
The sensor device according to claim 1 , further comprising a through hole at a position overlapping with the second contact portion. The first contact portion is
The sensor device according to claim 4 , wherein the sensor is provided at a position that does not overlap the through hole of the base material in a plan view. The first electrode is
The sensor device according to claim 1 , further comprising a conductive film formed on a contact portion with the first contact portion. The sensor device according to claim 1 , further comprising a protrusion portion that deforms a part of the first electrode into a convex shape at a position that overlaps with the first contact portion in a plan view. The second electrode is
The sensor device according to claim 4 , wherein a conductive film is formed on a contact portion with the second contact portion. The sensor device according to claim 4 , further comprising a protrusion portion for deforming a part of the second electrode into a convex shape at a position overlapping the second contact portion in a plan view. A vehicle seat comprising the sensor device according to any one of claims 1 to 9.

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