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:
Mar. 29, 2011
Filed:
Aug. 05, 2008
Applicant:
Takeshi Irie, Yokohama, JP;
Inventor:
Takeshi Irie, Yokohama, JP;
Assignee:
Sumitomo Electric Industries, Ltd., Osaka-Shi, JP;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01S 3/00 (2006.01);
U.S. Cl.
CPC ...
Abstract
A control circuit for a laser diode is disclosed, in which the driving current may be suppressed even when the monitor PD breaks down to make the APC feedback control inoperable. The control circuit comprises an LD driver to supply the driving current to the LD, a monitor PD to detect a portion of output light from the LD, and the APC controller to adjust the driving current. The current limiter, when the driving current reaches or exceeds the threshold, controls the driving current Id so as to keep the current in a preset value or a value just before the extraordinary increase of the driving current occurs.