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. 21, 2008
Filed:
Jul. 24, 2007
Donald C. Arns, Jr., Sonoma, CA (US);
Pablo Garcia, Menlo Park, CA (US);
Donald C. Arns, Jr., Sonoma, CA (US);
Pablo Garcia, Menlo Park, CA (US);
SRI International, Menlo Park, CA (US);
Abstract
A position-sensing system magnetically senses the position of a first component moving with respect to a second component. A magnetically hard layer on the first component provides a recording medium. Information is magnetically recorded in regions of the magnetically hard layer. These regions provide a relative encoding scheme for determining the position of the first component. Magnetic-field sensors are positioned over redundant tracks of magnetically recorded regions. Each magnetic-field sensor positioned over a given track senses the same magnetized regions while the first component moves with respect to the second component. Other magnetic-field sensors can sense ambient fields for use in performing common-mode rejection. A write head can dynamically repair damaged or erased regions detected by the magnetic-field sensors. Energized by a battery-backup power source, the magnetic-field sensors and associated circuitry can continue to track movement of the first component when the machinery is off.