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. 08, 1983
Filed:
Mar. 31, 1981
Robert M Shoji, Gardena, CA (US);
John S Chudy, Long Beach, CA (US);
Discovision Associates, Costa Mesa, CA (US);
Abstract
A control system for use in controllably adjusting a prescribed characteristic of a beam scanning a record medium. In the preferred embodiments, the control system is embodied in a tracking apparatus for use in a playback system for recovering information from a selected recording track on an optical record medium such as a video disc. The tracking apparatus produces a tracking error signal representative of the deviation of a scanning reading beam from the centerline of the selected track, and couples this error signal to a movable tracking mirror to form a servo for controllably positioning the beam in alignment with the track. The tracking apparatus further includes a dimple compensation circuit for monitoring the tracking error signal and producing a tracking loop disable signal whenever it determines that the reading beam is scanning a video disc defect, such as a dimple. This disable signal is used to uncouple the tracking error signal from the tracking mirror, so that the reading beam is maintained at its current position until the dimple has been passed.