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:
Feb. 06, 1990
Filed:
Dec. 02, 1988
Isamu Shibata, Fuchu, JP;
Takahiro Asai, Yokohama, JP;
Kiyoto Nagasawa, Yokohama, JP;
Kenichirou Asada, Tokyo, JP;
Ricoh Co., Ltd., Tokyo, JP;
Abstract
A semiconductor laser control apparatus for controlling an optical output of a semiconductor laser to a predetermined value comprises a switching part coupled in series with the semiconductor laser and controlled by an N-bit image signal, N constant current supply circuits coupled in parallel to each other and in series with the switching part for supplying currents to the switching part so that a driving current is supplied to the semiconductor laser from the switching part, a detector for detecting the optical output of the semiconductor laser and for outputting a detection signal indicative of the detected optical output, and a control part responsive to the detection signal from the detector for controlling the driving current by controlling the N constant current supply circuits so that the optical output of the semiconductor laser becomes the predetermined value.