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:
Aug. 11, 1992
Filed:
Nov. 06, 1991
Etsuo Yamada, Sagamihara, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
An optical information recording apparatus according to the present invention prevents the saturation of an output of an amplifier, and thereby effects stable tracking and/or focusing servo. The recording apparatus includes a device for inputting an input signal modulated between at least two levels which are not zero in accordance with recording information, a device for converging a light beam intensity modulated between at least two levels which are not zero into a spot-like shape in accordance with the input signal, for scanning a recording medium, and for recording the information, a device for detecting a signal indicative of a positional error between the light beam spot and the medium in at least one of a focusing direction and a tracking direction, a servo device for correcting the positional error on the basis of the detected signal, a device for changing a gain of the servo in accordance with an intensity level of the light beam, and a device for delaying the gain by a predetermined time corresponding to a time period for a change in the level of the input signal from a higher level to a lower level.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile