Capacitive acceleration detector having reduced mass portion
First Claim
Patent Images
1. An acceleration detector comprising:
- (a) a pair of substrates respectively having electrically insulating surfaces disposed opposite to each other;
(b) fixed electrodes respectively provided on said electrically insulating surfaces of said pair of substrates;
(c) a cantilever having a fixed end supported between said pair of substrates, and a free end which is freely swingable in an area between said pair of substrates; and
(d) an electrically conductive mass substance formed at said free end of said cantilever so as to be freely swingable in between said fixed electrodes and containing at least two spaces in its inside, in which said spaces inside of said mass substance respectively communicate by way of openings formed in surfaces of said mass substance which are opposite to said fixed electrodes, the diameter of said openings being smaller than the dimension of said spaces in a direction parallel to said surfaces.
1 Assignment
0 Petitions
Accused Products
Abstract
Disclosed is an acceleration detector which has an electrically conductive mass portion formed at a free end of a cantilever, and fixed electrodes arranged opposite to the mass portion through a gap so that the value of acceleration is detected on the basis of the change of capacitance between the mass portion and the fixed electrodes, and in which at least one space is formed in the inside of the mass portion to lighten the weight of the mass portion to thereby widen the range of measurement.
37 Citations
10 Claims
-
1. An acceleration detector comprising:
-
(a) a pair of substrates respectively having electrically insulating surfaces disposed opposite to each other; (b) fixed electrodes respectively provided on said electrically insulating surfaces of said pair of substrates; (c) a cantilever having a fixed end supported between said pair of substrates, and a free end which is freely swingable in an area between said pair of substrates; and (d) an electrically conductive mass substance formed at said free end of said cantilever so as to be freely swingable in between said fixed electrodes and containing at least two spaces in its inside, in which said spaces inside of said mass substance respectively communicate by way of openings formed in surfaces of said mass substance which are opposite to said fixed electrodes, the diameter of said openings being smaller than the dimension of said spaces in a direction parallel to said surfaces. - View Dependent Claims (2, 3)
-
-
4. An acceleration detector comprising:
-
first and second fixed electrodes disposed in spaced relation to each other; and a third movable electrode having a mass portion interposed between and spaced from said first and second fixed electrodes by predetermined gaps and a fixed cantilever portion supporting said mass portion for free movement toward and away from said first and second fixed electrodes in response to an acceleration force; wherein said mass portion of said third movable electrode is provided with a plurality of internal empty cavities which each communicate with a surface of the mass portion by way of a hole which is smaller than the size of the cavity. - View Dependent Claims (5, 6, 7, 8, 9, 10)
-
Specification