Three-dimensional acceleration sensor and airbag using the same
First Claim
1. A three-dimensional acceleration sensor having a support on which a stationary electrode is arranged, a central part fixed to said support, a single massive part constituting a movable electrode, a link arrangement for interconnecting said central part and said single massive part, and comprised of diaphragms and beams which are operatively provided around said central part, means for sensing changed electrical capacitance between the stationary electrode and the single massive part at four positions of the sinqle massive part, and means for detecting applied acceleration in response to changes in sensed electrical capacitance at the four positions by addition and subtraction of change electrical capacitance values.
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Accused Products
Abstract
A three-dimensional acceleration sensor capable of detecting a small acceleration value and even an acceleration value amounting up to 100G occurring in the event of a collision comprises a diaphragm for linking a frame and a massive part and diaphragms and beams for linking the massive part and a central part. These elements are formed by working a single crystalline silicon plate. Gaps between the massive part and opposing electrodes are changed by acceleration applied to the massive part. A circuit connected to terminals detects the changes in gaps as changes in capacitances and determines direction and level of the applied acceleration.
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Citations
11 Claims
- 1. A three-dimensional acceleration sensor having a support on which a stationary electrode is arranged, a central part fixed to said support, a single massive part constituting a movable electrode, a link arrangement for interconnecting said central part and said single massive part, and comprised of diaphragms and beams which are operatively provided around said central part, means for sensing changed electrical capacitance between the stationary electrode and the single massive part at four positions of the sinqle massive part, and means for detecting applied acceleration in response to changes in sensed electrical capacitance at the four positions by addition and subtraction of change electrical capacitance values.
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10. A three -dimensional acceleration sensor, comprising a stationary electrode, a support on which the stationary electrode is arranged and a single massive part, constituting a movable electrode,
a frame surrounding said single massive part a link member comprised of a diaphragm and linking said frame and said single massive part, means for sensing changed electrical capacitance between the stationary electrode and the single massive part at four positions of the single massive part, and means for detecting applied acceleration in response to changes in sensed electrical capacitance at the four positions by addition and subtraction of change electrical capacitance values.
Specification