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:
Feb. 04, 2003
Filed:
Jul. 07, 2001
Mark W. Chang, Palos Verdes, CA (US);
Scott D. Dalton, Berkeley, CA (US);
Michael J. Daneman, Pacifica, CA (US);
Timothy Beerling, Berkeley, CA (US);
Stephen F. Panyko, Novato, CA (US);
Gary M. Zalewski, Oakland, CA (US);
Onix Microsystems, Inc., Richmond, CA (US);
Abstract
A method and apparatus for maintaining the state of a MEMS device in the event of a power failure are disclosed. The apparatus and method may be used with a MEMS device generally having one or more MEMS elements moveably coupled to a substrate that uses electrostatic clamping force to sustain the state of the MEMS element. According to the method, a capacitive or other charge-storing circuit is coupled between a clamping surface and an electrical ground. During normal operation, a clamping voltage is applied between the clamping surface and at least one MEMS element to retain the at least one MEMS element against the clamping surface. In the event of a power failure, the source of the clamping voltage and other circuit paths to ground are isolated from the clamping surface. The charge-storing circuit maintains an electric charge on the clamping surface. Leaky circuit paths to ground may be isolated from the clamping surface by an isolator element configured to electrically isolate the clamping surface in the event of a power failure. The isolator element may include an opto-isolator or a low leakage diode.