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:
Apr. 20, 2004
Filed:
Jul. 16, 2001
Wai-Hon Lee, Cupertino, CA (US);
Other;
Abstract
An optical track sensing device, and in particular to an optical sensor for detecting optical tracking information on a moving medium (or stationary medium and moving sensor). The sensing device relies on self-imaging, rather than optics, and obtains a very acceptable detected signal at other than the self imaging plane of the reflection off a moving medium. This provides more flexibility in the placement of the sensor, while still allowing the elimination of optical components by relying on self-imaging instead. In addition, by providing a pattern over the photodetector with a smaller period, higher frequency harmonics are detected, allowing more precise detection of the position of the medium. In one embodiment, the period of the detector pattern is selected to detect the higher harmonics of the grating on the moving medium.