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:
Sep. 22, 1992
Filed:
Nov. 18, 1991
Satoshi Shikichi, Tokyo, JP;
Shigeto Kanda, Machida, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
An optical information recording apparatus includes a recording device for condensing a light beam into a spot-like shape, the light beam having been intensity-modulated between at least two levels which are not zero, scanning the light beam on a recording medium and recording information thereon; a detector for detecting a signal indicative of the position error between the light beam spot and the medium in the focusing direction perpendicular to the surface of the medium or the tracking direction in a plane parallel to the surface of the medium which is perpendicular to tracks formed on the medium; a servo device for correcting the position error on the basis of the detected signal; a device for varying the gain of the servo device in conformity with the intensity level of the light beam for producing a gain output; and a device for sampling and holding the gain output as the intensity of the light beam shifts between different levels.