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:
Jul. 27, 1988
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
An optical information processing apparatus comprises an optical head having an optical system contained in a frame and effecting at least one of recording and reproduction of information by applying a light beam condensed by the optical system to a recording medium, a detector for detecting at least one of a tracking signal and a focusing signal, a controller for moving at least a portion of the optical system in accordance with at least one of the tracking signal and the focusing signal, a detector for detecting the postion of the moving portion of the optical system relative to the frame, a position controller for controlling the moving portion so as to be held in a predetermined position, on the basis of the output signal of the position detecting detector, a detector for detecting the abnormality of at least one of the tracking and focusing controls, and a switching device for alternatively operating the tracking and focusing controller and the position controller and rendering the tracking and focusing controller inoperative and operating the position controller when the abnormality of the tracking or focusing control is detected.