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:
Jun. 11, 1985
Filed:
Aug. 26, 1982
Applicant:
Inventors:
Takeshi Maeda, Kokubunji, JP;
Yasumitsu Mizoguchi, Odawara, JP;
Masahiro Takasago, Odawara, JP;
Tokuya Kaneda, Odawara, JP;
Yoshito Tsunoda, Mitaka, JP;
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G01J / ; H01S / ;
U.S. Cl.
CPC ...
250205 ; 372 38 ;
Abstract
A driving circuit for driving a semiconductor laser by a driving signal containing a pulse signal representing given information and superposed on a DC bias signal includes means for monitoring intensity of laser light emitted when the DC bias is applied, and means for monitoring the intensity of laser light emitted when the pulse signal is applied. The DC bias signal and the pulse signal are varied in dependence on the result of comparisons between the outputs of the monitoring means and respective predetermined reference values.