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:
Nov. 17, 2009
Filed:
Apr. 10, 2008
Applicants:
Yimin Guo, San Jose, CA (US);
Grace Gorman, San Jose, CA (US);
Inventors:
Yimin Guo, San Jose, CA (US);
Grace Gorman, San Jose, CA (US);
Assignee:
MagIC Technologies, Inc., Milpitas, CA (US);
Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
G01B 7/30 (2006.01); G01R 33/09 (2006.01);
U.S. Cl.
CPC ...
Abstract
The invention discloses a rotation sensor suitable for gear wheels. MR (magneto-resistive) sensors are placed inside a zero field region generated by at least two permanent magnets. The sensors are divided into two groups that are immersed in different locally generated magnetic environments. A differential signal taken between the two groups then senses the movement of the wheel's teeth. A single wafer method for manufacturing the device is also briefly described.