The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 19, 1993
Filed:
Jul. 17, 1992
Henry V Allen, Freemont, CA (US);
Stephen C Terry, Palo Alto, CA (US);
Diederik W De Bruin, Santa Clara, CA (US);
I C Sensors, Milpitas, CA (US);
Abstract
An apparatus and method of operation for a self-testable accelerometer having a housing, a diaphragm for detecting movement in response to an applied force, a mass on the diaphragm, at least one capacitive plate attached to the housing and disposed such that a potential difference between the capacitive plate and the mass causes a movement of the mass, electrodes for applying a potential difference between the mass and the capacitive plate, and at least one piezoresistive element attached to the housing and the diaphragm for sensing movement of the mass. The accelerometer's housing comprises a frame, a base and a cap with air gaps providing squeeze film damping and mechanical stops for inhibiting movements of the mass. The combination of the capability to electrostatically produce a movement of the mass and the piezoresistive sensing of that movement allows testing and calibration of the accelerometer at any stage in its manufacture or deployment without the need for external equipment such as shakers.