JP2001122010A - Sitting sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a sitting sensor capable of judging existence of sitting and size of a sitting human body. SOLUTION: This sitting sensor 1 is provided with a first and a second electrodes 11, 12 arranged opposite to each other with the predetermined gap, and a dielectric member 13 having elasticity and provided between the first and the second electrodes 11, 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seating sensor, and more particularly to a seating sensor capable of determining the size of a seated person in detail.

[0002]

2. Description of the Related Art In recent years, an airbag is generally installed in a motor vehicle to protect a driver in a driver's seat and a passenger's seat from the impact of a collision accident. However, if the passenger in the front passenger seat is a child, an accident may cause unexpected injuries when the airbag is activated by a collision accident. It is desired to stop.

In Japanese Patent Application No. 10-119122, the present applicant installs a detection unit having a plurality of switch elements on a passenger seat, and sits on the passenger seat depending on the number of closed switches. It discloses a seating sensor for determining whether a person who has made an adult or a child. In this case, the detection unit is configured using, for example, a membrane sheet, and determines whether the occupant is an adult or a child based on the number of closed switches as a seating area.

[0004]

Since such a seating sensor uses a mechanical switch, it is necessary to depress the seating portion with a predetermined stroke in order to turn on the switch. Depending on the weight of the person, the predetermined stroke may be insufficient, and the seating area may not be accurately determined.

The present invention has been made in view of the above problems, and has as its object to provide a seating sensor capable of determining the size of a seated person in detail.

[0006]

In order to achieve the above object, in a seating sensor according to the present invention, a first and a second electrode, which are opposed to each other with a predetermined gap, are provided.
And an elastic dielectric member provided between the second electrodes. According to the present invention, the size of a seated person can be determined in detail.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A seating sensor according to the present invention comprises first and second electrodes which are disposed opposite each other with a predetermined gap therebetween, and a dielectric member provided between the first and second electrodes. The presence or absence of the seat and the size of the seated person are determined from the change in the capacitance formed between the first and second electrodes.

First, the operation principle of the seating sensor according to the present invention will be described. FIG. 1 is a diagram showing the principle of the present invention. The seating sensor 1 according to the present invention has an area S (hereinafter referred to as an area S)
A first electrode 11 having an electrode facing area) and a second electrode 11
Of the first electrode 1 are arranged at a predetermined distance L (hereinafter, referred to as an electrode facing distance) via the support member 3.
A dielectric material 13 is sealed between the first and second electrodes 12. The first electrode 11 is made of a flexible material. A capacitance C is generated between the first electrode 11 and the second electrode 12, and this value is proportional to the electrode facing area S and the electrode facing distance L when the dielectric constant ε of the dielectric substance 13 is constant. Inversely proportional. The support member 3 is made of an insulating material.

FIG. 2 is a schematic diagram when the user is seated. The first electrode 11 and the second electrode 12 face each other at an electrode facing distance L, and when the passenger is seated, the first electrode 11 is bent, and the electrode facing area S and the electrode facing distance L are respectively equal to those before sitting. It shows different values and therefore the capacitance C changes. According to the present invention, when the capacity C exceeds a predetermined first threshold value, it is determined that the occupant is seated. Here, FIG.
2 shows a case where the passenger is an adult 15, and FIG. 2 (b) shows a case where the passenger is a child 16. Since the capacity C changes depending on the weight and seating area of the passenger, the boarding is performed by the capacity C. It is also possible to determine whether the person is an adult or a child. In this case, for example, if it is larger than the predetermined second threshold value, it may be determined that it is an adult, and if it is smaller, it is determined that it is a child. As a detection circuit for the capacitance C and a determination circuit for determining the magnitude of the value of the capacitance C, a known capacitance meter can be used.

When the occupant leaves the seat, the first electrode 11
It is restored to a state without seating, and the electrode facing area S and the electrode facing distance L need to return to the values in the initial state. The restoring function for this purpose will be described later in the form of a seat, the first electrode 11. , The dielectric substance 13, a combination thereof, or further restoring means. However, despite the above-described restoring function, if the occupant is repeatedly seated and unseat, the configuration of the seating sensor at the time of unseat is deformed due to deterioration of each component, and the occupant's seat can be accurately detected. May be gone. Therefore, in the seating sensor according to the present invention,
Each time the passenger stands from the seat, the value of the capacity C at that time is taken as an initial value and used as a reference value for detection of the next seating. This function can be realized by, for example, a software configuration in the control IC in the above-described determination circuit.

As described above, according to the seating sensor of the present invention, it is possible to not only determine whether the passenger in the passenger seat is an adult or a child, but also to classify in detail both the seating area and the weight of the passenger. It is also possible to control vehicle airbags and the like more finely and improve safety. Further, in a conventional example using a mechanical switch, it is necessary to press down a seating portion with a predetermined stroke to turn on the switch. Depending on the weight of the person sitting, such as when sitting, it may not be possible to accurately determine the seating area due to insufficient predetermined stroke, but according to the present invention, if the passenger is seated, Capacity C
, The seating can be reliably detected.

The first electrode 11 and the second electrode 12
Is a thin film or foil of a metal such as gold, silver, copper, nickel, aluminum or tin, a thin film of carbon or graphite, or indium tin oxide (ITO). As a substance sealed between the first electrode 11 and the second electrode 12, a short circuit does not occur between the first electrode 11 and the second electrode 12, and the first electrode 11 and the second Any fluid that can measure the magnitude of the capacitance generated between the two electrodes 12 or a solid whose thickness is deformable can be used.
Examples thereof include gases such as air, nitrogen or other inert gas, liquids such as silicon oil, pure water or chlorofluorocarbon, gelatinous substances such as gelatin or glycerin, sponge rubber sheets, urethane foam, foamed silicone, and foamed styrene. Alternatively, there is an elastic solid such as foamed polyethylene terephthalate. For example, when foamed plastic is used, the plastic may be filled between the first and second electrodes while foaming the plastic.

The base member of the seat 2 is made of a plastic film such as polyethylene terephthalate, polyethylene naphthalate, polyetheretherketone, polycarbonate, polyethylene, polyvinyl chloride or the like, a thin plate of plastic, reinforced glass, paper, nonwoven fabric, or the like.
There are cloth, leather, synthetic leather, rubber, and synthetic rubber. Further, the base member may be formed integrally with the first electrode 11 and the second electrode 12, and in this case, metal or carbon is kneaded in cloth woven with conductive fibers, or rubber or plastic. Composite materials are conceivable.

The support member 3 is a thin insulating material,
For example, polyethylene terephthalate, polyethylene naphthalate, polyetheretherketone, polycarbonate, polyethylene, polyvinyl chloride and other plastic films or plastic thin plates, tempered glass,
Examples include paper, nonwoven fabric, cloth, leather, synthetic leather, rubber, and synthetic rubber. It may be formed integrally with the base member of the seat 2 described above.

The seating sensor according to the present invention can be realized by appropriately selecting constituent materials of each electrode, dielectric substance, base member, support member and the like from such materials. Although the structure of the seating sensor according to the present invention varies widely depending on the combination of the constituent materials, it is particularly affected by what kind of dielectric substance is. That is, when a gas other than a liquid, air, or a gel substance is used as the dielectric, it is preferable to have an airtight structure in order to prevent such substances from leaking out of the seating sensor.

Of these, the specific structure of the seating sensor of the present invention will be described with reference to several embodiments. FIG.
FIG. 2 is a diagram showing a first embodiment according to the present invention. FIG.
FIG. 3A is a perspective view of an automobile seat, and FIG.
1 is a sectional view of a seating sensor according to the present embodiment. According to the seating sensor 1 of the present embodiment, the first electrode 11 and the second electrode 12 are arranged to face each other. In this embodiment, the first electrode 11 and the second electrode 12 are made of carbon. However, the present invention is not limited to this. Gold, silver, copper, nickel,
It may be a thin film or foil of a metal such as graphite, tin, or aluminum, or indium tin oxide. Also,
A cloth in which conductive fibers are woven or a composite material in which metal, carbon, or the like is kneaded in rubber or plastic may be used.

In the present embodiment, polyvinyl chloride is used for the base member 21 of the seat. However, the present invention is not limited to this, and plastics such as polyethylene terephthalate, polyethylene naphthalate, polyether ether ketone, polycarbonate, and polyethylene are used. Thin film or plastic, tempered glass, paper, non-woven fabric,
It may be cloth, leather, synthetic leather, rubber, synthetic rubber, or the like.

A dielectric material 13, which is a fluid, is sealed between the first electrode 11 and the second electrode 12. In the present embodiment, silicon oil which is a liquid is used as the dielectric substance 13. However, the present invention is not limited to this. Liquid such as pure water or chlorofluorocarbon, gel substance such as gelatin or glycerin, or air , Nitrogen or other inert gas.

In order to prevent the dielectric substance 13 from flowing out of the seating sensor 1, an airtight structure is formed by the sealing member 22, and the dielectric substance 13 is sealed. In this embodiment, a double-sided tape is used as the sealing member 22, but an adhesive or other sealing agent may be used. An opening 23 is provided in a part of the sealing member 22 so that the dielectric substance 13
An external fluid reservoir 24 accommodating a part of is connected through an opening 23.

The external fluid reservoir 24 is made of an elastic substance such as rubber, and has a function of restoring the shape of the first electrode 11 when the user leaves the seat together with the elastic force of the base member 21. That is, when the occupant sits on the seat 2, the shape of the first electrode 11 is deformed, and an amount of the dielectric substance 13 corresponding to the occupant's weight and seating area is accumulated in the external fluid reservoir 24.
However, when the occupant leaves the seat, the flowed dielectric substance 13 is pushed back by the elastic force of the external fluid reservoir 24, and the shape of the first electrode 11 is restored.

In the case where a gas such as air, nitrogen or other inert gas is used as the dielectric substance 13 as in this embodiment, the shape of the first electrode 11 is changed to the initial state when the user leaves the desk. As the returning restoring means, a means having a cylinder or a pump (not shown) may be used. For example,
When a pump is used as the restoring means, the shape of the first electrode 11 is restored by pressurizing the pump when the user leaves the seat.

In particular, when a pump is used as the restoring means when the dielectric substance 13 is air, an exhaust valve (not shown) is further provided in a part of the airtight structure, and the air is supplied to the outside through the exhaust valve when seated. The first electrode 11 may be returned to its original shape by pressurizing with a pump when leaving the seat. By the way, when air is used as the dielectric substance 13 in particular, an elastic body such as a spring or rubber is used as a restoring unit instead of the sealing member 22 without providing an airtight structure by the sealing member 22, so that the user can sit and leave the seat. The occasional outflow and inflow of air may be left to exchange with an external space via an intake port or the like.

FIG. 4 is a diagram showing a second embodiment according to the present invention. FIG. 4A is a top view of the seating sensor according to the present embodiment, and FIG. 4B is a cross-sectional view of the seating sensor according to the present embodiment. The first electrode 11 and the second electrode 12 are formed integrally with the base member of the sheet. In this embodiment, silicon rubber in which carbon and silver are kneaded is used, but a conductive material such as metal, carbon, or graphite is kneaded in a cloth in which conductive fibers are woven, or rubber, plastic, or glass. It may be composed of embedded composite material.

A support member 31 is provided between the first electrode 11 and the second electrode 12, and is filled with a dielectric substance 13. For the support member 31, for example, a thin film of plastic film or plastic such as polyethylene terephthalate, polyethylene naphthalate, polyetheretherketone, polycarbonate, polyethylene or polyvinyl chloride, or tempered glass, paper, nonwoven fabric,
There are thin insulating materials such as cloth, leather, synthetic leather, rubber or synthetic rubber.

In this embodiment, air is used as the dielectric substance 13. An O-ring 32 made of rubber is provided to prevent air as the dielectric substance 13 from leaking from the seating sensor 1, and a stopper 33 made of plastic (FIG. 4A)
(Not shown) is fitted to the outside thereof, thereby forming an airtight structure. The dielectric substance 13 may be a liquid such as silicon oil, pure water or chlorofluorocarbon, a gel substance such as gelatin or glycerin, or a gas such as nitrogen or another inert gas.

When the occupant sits on the seat 2, the shape of the first electrode 11 is deformed, but an amount of air corresponding to the occupant's weight and seating area is surrounded by the support member 31 and the O-ring 32. Flow into When the user leaves the seat, the flowing air is pushed back by the elastic force of the O-ring 32, and the shape of the first electrode 11 is restored. Note that a cylinder or a pump as described in the first embodiment may be further provided as restoring means for returning the shape of the first electrode 11 to the initial state when the user leaves the seat (not shown). Further, it may be an elastic insulating solid such as rubber.

In the seating sensor having the structure shown in FIG. 4, a sponge rubber sheet is used as the dielectric substance 13.
An elastic solid such as urethane foam, silicone foam, styrene foam, or polyethylene terephthalate foam may be used. In this case, the dielectric substance 13 does not need to be sealed in an airtight structure, and a means other than a cylinder or a pump is used as a further restoring means.

FIG. 5 is a diagram showing a third embodiment according to the present invention. FIG. 5A is a top view of the seating sensor according to the present embodiment, and FIG. 5B is a cross-sectional view of the seating sensor according to the present embodiment. In this embodiment, the first electrode 11 and the second electrode 12 are made of aluminum foil. Besides this, gold,
A thin film or foil of a metal such as silver, copper, nickel, carbon, graphite, or tin, or indium tin oxide may be used. Further, a cloth in which conductive fibers are woven, or a composite material in which metal, carbon, or the like is kneaded in rubber or plastic may be used.

Foamed silicone is sealed between the first electrode 11 and the second electrode 12 as a dielectric substance 13. The sponge rubber sheet, urethane foam, foamed silicone, foamed styrene, foamed polyethylene terephthalate, etc. It may be. Polyethylene terephthalate is used for the base member 21 and the support member 31 of the sheet, and a plastic film such as polyethylene naphthalate, polyetheretherketone, polycarbonate, polyethylene, polyvinyl chloride or a thin plate of plastic, reinforced glass, cloth, leather , Synthetic leather, rubber, or synthetic rubber may be used.

The base member 21 and the support member 31 are thermocompressed or caulked. The support member 31 has an opening 23. When the occupant sits on the seat 2, the shape of the first electrode 11 is deformed, and the foamed silicone is also deformed according to the occupant's weight and seating area. When the user leaves, the shape of the first electrode 11 is restored by the elastic force of the foamed silicone. Air flows in or out through the opening 23 according to the deformation of the foamed silicone.

Incidentally, as a restoring means for returning the shape of the first electrode 11 to the initial state when leaving the seat, an elastic solid such as rubber, a spring or the like may be further provided. FIG. 6 is a diagram showing a fourth embodiment according to the present invention. FIG. 6A is a perspective view of the seating sensor according to the present embodiment, and FIG. 6B is a cross-sectional view of the seating sensor according to the present embodiment.

In this embodiment, the first electrode 11 and the second electrode 12 made of indium tin oxide are arranged to face each other, but the first electrode 11 is divided into predetermined regions. Each capacitance formed between the divided first electrode 11 and the second electrode is individually detected, and a detection circuit therefor can be realized by a known technique. Also,
In this embodiment, a logic circuit for judging the seating state from the individually detected capacitance is further provided. By dividing the electrodes into a plurality of areas in this manner, for example, when two or more children are seated on the seat, the number of the children can be detected in detail.

The first electrode 11 and the second electrode 12 are made of aluminum foil in addition to indium tin oxide, but are made of metal such as gold, silver, copper, nickel, carbon, graphite, tin, and aluminum. May be a thin film or foil. Also, cloth woven with conductive fibers, or rubber,
A composite material in which metal, carbon, or the like is kneaded in plastic may be used.

Glycerin, which is a gel-like substance, is sealed between the first electrode 11 and the second electrode 12 as a dielectric substance 13. The dielectric substance 13 is a gas such as air, nitrogen or other inert gas, silicon, or the like. It may be an oil, a liquid such as pure water or Freon, a gel substance such as gelatin, or an elastic solid such as a sponge rubber sheet, urethane foam, silicone foam, styrene foam or polyethylene terephthalate foam.

In the present embodiment, polyethylene naphthalate is used for the base member 21 and the support member 31 of the sheet. A plastic film such as polyethylene terephthalate, polyether ether ketone, polycarbonate, polyethylene, polyvinyl chloride, or a thin plate of plastic is used. , Tempered glass, cloth, leather, synthetic leather, rubber, synthetic rubber, or the like may be used.

The outside of the base member 21 and the support member 31 is an adhesive as a sealing member 22 (not shown in FIG. 6A).
Are provided so as to surround the dielectric material 1.
3 is sealed, and an airtight structure is maintained. Note that when an elastic solid such as a sponge rubber sheet, foamed urethane, foamed silicone, foamed styrene, or foamed polyethylene terephthalate is used as the dielectric substance 13, it is not necessary to have an airtight structure.

As a restoring means for returning the shape of the first electrode 11 to the initial state when leaving the seat, a cylinder or a pump as described in the first embodiment may be further provided.
Further, an elastic solid such as rubber may be used as the restoration means. When an elastic solid such as sponge rubber sheet, foamed urethane, foamed silicone, foamed styrene, or foamed polyethylene terephthalate is used as the dielectric substance 13, as a further restoring means, an elastic solid such as rubber, spring, or the like is used. May be further provided.

Other than a cylinder or a pump will be used.

[0039]

As described above, according to the present invention,
The seating sensor is provided with electrodes arranged opposite to each other with a predetermined gap and a dielectric member provided between the electrodes, and determines the presence or absence of seating and the size of the seated person based on a change in capacitance formed between the electrodes. Since it is determined, for example, when used in an in-vehicle airbag or the like, it is not only possible to determine whether the passenger in the passenger seat is an adult or a child, but also to detect the size of the passenger in terms of both the seating area and the weight. It is possible.

Further, by dividing the electrode into a plurality of regions, for example, when two or more children are seated on the seat, the number of the children can be detected in detail. Furthermore, the seating sensor according to the present invention may be used for seats of railways, aircraft, hairdressing and beauty equipment, medical equipment, and the like, in addition to onboard airbags and the like.

[Brief description of the drawings]

FIG. 1 is a principle configuration diagram of the present invention.

FIG. 2 is a schematic diagram when the user is seated.

FIG. 3 is a diagram showing a first embodiment according to the present invention.

FIG. 4 is a diagram showing a second embodiment according to the present invention.

FIG. 5 is a diagram showing a third embodiment according to the present invention.

FIG. 6 is a diagram showing a fourth embodiment according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Seating sensor 2 ... Seating part 3, 31 ... Support member 11 ... 1st electrode 12 ... 2nd electrode 13 ... Dielectric substance 21 ... Base member 22 ... Sealing member 23 ... Opening 24 ... External fluid pool 32 ... O-ring 33 ... Stopper C ... Capacitance L ... Electrode facing distance S ... Electrode facing area

[Procedure amendment]

[Submission Date] February 8, 2000 (200.2.8)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

Claims (24)

[Claims] 1. A semiconductor device comprising: first and second electrodes arranged to face each other with a predetermined gap therebetween; and an elastic dielectric member provided between the first and second electrodes. Seating sensor. 2. The seating sensor according to claim 1, wherein at least one of the first and second electrodes is divided for each predetermined area. 3. The seating sensor according to claim 1, wherein the first and second electrodes are elastic members woven with conductive fibers. 4. A base member provided on a side opposite to a surface of the first and second electrodes opposite to each other.
The seating sensor according to any one of the preceding claims. 5. The seating sensor according to claim 1, wherein the dielectric member is sealed in a closed structure. 6. The seating sensor according to claim 5, further comprising an external fluid reservoir for accommodating a part of the dielectric member flowing out at the time of sitting. 7. The seating sensor according to claim 6, wherein the external fluid reservoir is formed of an elastic body. 8. The seating sensor according to claim 6, wherein the external fluid reservoir has a cylinder structure. 9. The method according to claim 1, wherein the dielectric member is a gas.
The seating sensor according to any one of claims 8 to 13. 10. The seating sensor according to claim 9, wherein the gas is air. 11. The gas according to claim 9, wherein the gas is an inert gas.
2. The seating sensor according to 1. 12. The method according to claim 1, wherein the dielectric member is a liquid.
The seating sensor according to any one of claims 1 to 8. 13. The seating sensor according to claim 1, wherein the dielectric member is a gel material. 14. The dielectric member according to claim 1, wherein said dielectric member is solid.
The seating sensor according to any one of claims 1 to 5. 15. The seating sensor according to claim 14, wherein the solid is a sponge rubber sheet. 16. The seating sensor according to claim 14, wherein the solid is a foamed plastic material. 17. The apparatus according to claim 1, further comprising a restoring means for returning the shapes of the first and second electrodes to the shapes before sitting after leaving the seat.
The seating sensor according to any one of claims 13 to 13. 18. The apparatus according to claim 1, further comprising restoring means for returning the shape of the first and second electrodes to the shape before sitting after leaving the seat.
The seating sensor according to any one of claims 4 to 16. 19. The apparatus according to claim 1, wherein said restoring means is a pump.
A seating sensor according to claim 7. 20. The seating sensor according to claim 17, wherein the restoring means is a cylinder. 21. The seating sensor according to claim 17, wherein the restoring means is an elastic member. 22. The restoration means according to claim 17, wherein the restoration means is a spring.
Or the seating sensor according to 18. 23. The apparatus according to claim 1, further comprising capacitance detecting means for detecting a capacitance formed between said first and second electrodes.
23. The seating sensor according to claim 22. 24. A capacity for each leaving is stored as an initial value,
The seating sensor according to any one of claims 1 to 23, further comprising a capacity change detection unit configured to detect a change in capacity based on the initial value.