Method for adjusting sensitivity of acceleration sensor
AssigneesNGK Insulators, Ltd., NGK Optoceramics Co., Ltd.
InventorsHiroyuki Takahashi, Kazuyoshi Shibata, Hideki Andoh
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Abstract
The present invention provides a method for adjusting the sensitivity of an acceleration detecting device comprising a pair of piezoelectric elements, of an acceleration sensor device for detecting an externally acting acceleration. According to this method, electric charges produced in the pair of piezoelectric elements placed at positions being symmetric with respect to a weight are made to be equal to each other. The electric outputs of the piezoelectric elements are changed by varying the electrostatic capacity of the acceleration sensor device. Thus, noise sensitivity is suppressed.
Claims22
A method for adjusting sensitivity of an acceleration sensor device having an acceleration detecting device comprising a pair of piezoelectric elements for detecting an externally acting acceleration along a first axis direction, said method comprising the step of:
- changing an electric output of said piezoelectric elements by changing electrostatic capacity of said acceleration sensor device, such that a difference between absolute values of excitation outputs respectively generated in said piezoelectric elements of said acceleration detecting device become small when said acceleration sensor device is oscillated in a second axis direction perpendicular to the first axis direction.
A method for adjusting sensitivity of an acceleration sensor device having an acceleration detecting device comprising a pair of piezoelectric elements for detecting an externally acting acceleration, said method comprising the step of:
- changing an electric output of said piezoelectric elements by changing electrostatic capacity of said acceleration sensor device, said acceleration detecting device comprising:
- a weight;
- a support, installed around said weight, having a hollow portion;
- a flexible substrate put on said support so that said weight is suspended in said hollow portion of said support;
- and
- a pair of piezoelectric elements;
- wherein when said acceleration detecting device is adapted to detect an acceleration component in the X-direction or the Y-direction, the electrostatic capacity is changed so that a difference between absolute values of excitation outputs respectively generated in said piezoelectric elements of said acceleration detecting device become small when said acceleration sensor device is oscillated in the Z-direction, and when said acceleration detecting device is adapted to detect an acceleration component in the Z-direction, the electrostatic capacity is changed so that a difference between absolute values of excitation outputs respectively generated in said piezoelectric elements of said acceleration detecting device becomes small when said acceleration sensor device is oscillated in the X-direction or the Y-direction.
A method for adjusting sensitivity of an acceleration sensor device having an acceleration detecting device comprising a pair of piezoelectric elements for detecting an externally acting acceleration, said method comprising the step of:
- changing an electric output of said piezoelectric elements by changing electrostatic capacity of said acceleration sensor device,
- said acceleration detecting device comprising:
- a weight;
- a support, installed around said weight, having a hollow portion;
- a flexible substrate put on said support so that said weight is suspended in said hollow portion of said support;
- and
- a pair of piezoelectric elements;
- wherein when said acceleration detecting device is adapted to detect an acceleration component in the X-direction, the electrostatic capacity is changed so that shapes of said piezoelectric elements are symmetric with respect to the X-axis and so that a difference between absolute values of excitation outputs respectively generated in said piezoelectric elements of said acceleration detecting device becomes small when said acceleration sensor device is oscillated in the Z-direction, and when said acceleration detecting device is adapted to detect an acceleration component in the Y-direction, the electrostatic capacity is changed so that shapes of said piezoelectric elements are symmetric with respect to the Y-axis and so that a difference between absolute values of excitation outputs respectively generated in said piezoelectric elements of said acceleration detecting device becomes small when said acceleration sensor device is oscillated in the Z-direction.
Dependencies are inferred from the claim text.