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:
Jul. 16, 1985
Filed:
Mar. 23, 1983
Ronald A Millar, Sunnyvale, CA (US);
Xerox Corporation, Stamford, CT (US);
Abstract
The synchro-servo zones of the data blocks of an optical disc track are provided with information which will permit the generation of clock synchronization pulses and tracking pulses, with those latter pulses being used with peak detector/sample and hold circuitry of novel design to generate a substantially noise free tracking information servo feedback signal. Specifically, a pair of pulses having respective amplitudes proportional to the displacement of the read/write beam from the center of the track are generated, with the peak amplitudes of those pulses being stored, and then compared to provide, after carrier filtering, a tracking information servo feedback signal which would have an amplitude proportional to the displacement of the read/write beam from the center of the track and a sign or sense indicative of the direction of the displacement. The feedback signal, having the proper corrective sign, could be applied to the tracking adjustment coils of a dual axis optical head or mirror for moving the objective lens or mirror of the optical head so that the read/write beam moves toward the center of the track. A tracking accuracy of less than 0-1 .mu.m has been achieved using this method.