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:
Jan. 01, 1991
Filed:
Aug. 17, 1988
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
An apparatus for applying a light beam to an optical recording medium having tracks provided thereon and effecting at least one of recording and reproduction of information includes a light source emitting the light beam, an optical system for directing the light beam emitted from the light source to the medium, a device for receiving the light flux reflected by or transmitted through the medium and detecting a tracking error signal indicative of the deviation between the applied position of the light beam and a track, a tracking servo for moving at least a portion of the optical system on the basis of the tracking error signal and correcting the applied position of the light beam, a detector for detecting abnormality of tracking servo from the velocity of the moved portion of the optical system.