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:
Oct. 30, 1990
Filed:
Jul. 10, 1989
Etsuo Yamada, Sagamihara, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A laser driving device is disclosed. The laser driving device includes a semiconductor laser, a current source for supplying an electric current to the semiconductor laser, a photodetector for monitoring light emitted from the semiconductor laser, a plurality of setting circuits for outputting reference signals of different levels, a switching circuit for selecting one of the outputs of the setting circuits, a comparing circuit for comparing the output selected by the switching circuit with the output of the photodetector, and a control circuit for controlling the electric current supplied to the semiconductor laser on the basis of the output of the comparing circuit so that the two outputs become equal to each other. Also disclosed is an optical information recording apparatus using such a laser driving device.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile