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:
Dec. 31, 1991
Filed:
Oct. 11, 1989
Machiko Matsushita, Yokohama, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
An optical information processing apparatus includes a device for scanning tracks formed on an optical recording medium by a light beam, a device for moving the applied position of the light beam in a direction across the tracks, a device for detecting a tracking error signal indicative of the deviation between the applied position of the light beam and the tracks, a tracking servo device for feeding the tracking error signal back to the moving means, a switching device for selectively rendering the tracking servo device operative or inoperative, and a control device for measuring the time for which the tracking error signal exceeds a predetermined level, and switching the tracking servo device from its inoperative state to its operative state by the switching device after the aforementioned time exceeds a predetermined time.