EP0664456A1
Expired / Lapsed
EP
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Acceleration sensor
Assignee: Honda Motor Co Ltd
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Filing: 1995-01-20
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Granted: —
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Expires: 2015-01-20
Abstract
Abstract An acceleration sensor, incorporating a gas-filled closed space in which are disposed resistor elements for heating and/or sensing temperature, is fabricated on a semiconductor or insulating substrate through photoengraving to provide a small, accurate and reliable sensor. Various arrangements of heaters, temperature-sensing resistors and heating and temperature-sensing resistors are described, which detect acceleration direction as well as strength, and are advantageously but not necessarily fabricated using semiconductor technology. In the shown arrangement, heater (12) heats gas in a space (4). An acceleration leftwards causes gas to move to the right, so that resistor (14) heats up and increases its resistance, whilst resistor (13) cools and reduces its resistance. Thus, detection of resistance changes gives acceleration amount and direction. One of the temperature-sensing elements (13,14) may be removed. All three elements (12-14) may be replaced by two elements which both heat the gas and sense temperature.
Inventors
- 👤 Takashi Hosoi
- 👤 Satoshi Hiyama
- 👤 Sukeyuki Shinotuka
- 👤 Mizuho Doi
- 👤 Hiroshi Yamakawa
- 👤 Nariaki Kuriyama
- 👤 Tomoyuki Nishio
- 👤 Atsushi Inaba
- 👤 Nobuhiro Fueki
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-31 05:04
CPC Classifications
G; G01; G01P; G01P15/00; G01P15/18; G01P15/006; G01P15/008; G01P15/02; G01P15/08; G01P15/12
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
88 words
An acceleration sensor comprising a temperature-sensing resistor means disposed, in use, within a closed space, gas in the space being heated, and wherein the resistance of the resistor means changes when an acceleration acts on the sensor due to flow of the gas over the resistor means, characterised in that the sensor comprises a semiconductor or insulating substrate having a cavity therein, with the resistor means extends at least part way across the cavity, and in that the cavity and resistor means are fabricated using a photoengraving process.
Claim 2
Dependent Claim
24 words
The sensor of claim 1, wherein a second substrate is mounted on the cavitied substrate to close the cavity and form the closed space.
Claim 3
Dependent Claim
28 words
The sensor of claim 1 or 2, wherein the resistor means is integrally formed on a projection of the semiconductor or insulating substrate extending into the closed space.
Claim 4
Dependent Claim
32 words
The sensor of claim 3, wherein the resistor means is formed by the deposition of a metal onto the projection and by etching of the metal to form a desired resistive pattern.
Claim 5
Dependent Claim
31 words
The sensor of any preceding claim, wherein the resistor means is a heat-type temperature sensing resistor element which is used to both heat the gas and indicate acceleration by changing resistance.
Claim 6
Dependent Claim
71 words
An acceleration sensor comprising a temperature-sensing resistor means disposed, in use, within a closed space, gas in the space being heated, and wherein the resistance of the resistor means changes when an acceleration acts on the sensor due to flow of the gas over the resistor means, characterised in that the sensor comprises heater means for heating the gas, and in that the resistor means is spaced from the heater means.
Claim 7
Dependent Claim
28 words
The sensor of claim 6, wherein the sensor comprises a further temperature-sensing resistor means disposed on the opposite side of the heater means to the first resistor means.
Claim 8
Dependent Claim
72 words
An acceleration sensor comprising a heat-type temperature-sensing resistor means disposed, in use, within a closed space, the resistor means heating the gas and indicating acceleration of the sensor through a change in its resistance caused by gas flow thereacross, characterised in that the sensor comprises a further heat-type temperature-sensing resistor means, spaced from the first heat-type temperature-sensing resistor means, which also heats the gas and indicates acceleration through a change in resistance.
Claim 9
Dependent Claim
42 words
The sensor of claim 6, 7 or 8, wherein besides the heater means and temperature-sensing resistor means, or the pair of heat-type temperature-sensing resistor means, the sensor includes further such means in order to sense accelerations in two or three orthogonal directions.
Claim 10
Dependent Claim
39 words
The sensor of any of claims 6-9, wherein the sensor comprises a semiconductor or insulating substrate having a cavity therein for defining a portion of said closed space, the cavity and resistor means being fabricated using a photoengraving process.
Claim 11
Dependent Claim
24 words
The sensor of any preceding claim, including a bridge circuit for detecting the change in resistance of one or more of the resistor means.
Claim 12
Dependent Claim
22 words
The sensor of claim 11, wherein reference resistors of the bridge circuit comprise further temperature-sensing resistor means disposed in the closed space.
Claim 13
Dependent Claim
31 words
The sensor of any of claims 1 to 10, including comparator means to compare the output of a resistor means with a reference, in order to determine a change in resistance.
Claim 14
Dependent Claim
32 words
The sensor of any preceding claim, comprising a further temperature-sensing resistor means for detecting ambient temperature, with means being provided to correct the sensor output in accordance with the detected ambient temperature.
Claim 15
Dependent Claim
18 words
The sensor of any preceding claims, wherein one or more further heaters are provided in the closed space.
Claim 16
Dependent Claim
15 words
The sensor of any preceding claim, wherein the gas has a low heat transfer coefficient.
Claim 17
Dependent Claim
10 words
The sensor of claim 16, wherein the gas is pressurised.
Claim 18
Independent Claim
34 words
A method of fabricating an acceleration sensor, comprising the steps of forming by a photoengraving process a cavity in a semiconductor or insulating substrate and heater and temperature-sensing resistor means extending into the cavity.
Claim 19
Dependent Claim
21 words
The method of claim 18, including the step of mounting a further substrate on the first substrate to close the cavity.
Claim 20
Dependent Claim
36 words
The method of claim 18, wherein the cavity is formed to extend completely through the substrate and is closed at least at one of its open ends by a further substrate mounted on the first substrate.
Claim 21
Dependent Claim
54 words
An acceleration sensor comprising a pair of spaced apart resistor means disposed, in use, in a gas-filled closed space, gas in the space being heated by at least one of the elements, and an acceleration acting on the sensor being detected by monitoring the resistance of at least the other of the resistor means.
References Cited (Backward Citations)
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