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. 17, 1996
Filed:
Sep. 09, 1994
Applicant:
Inventor:
Setsuo Misaizu, Yokohama, JP;
Assignee:
Fujitsu Limited, Kanagawa, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04B / ;
U.S. Cl.
CPC ...
359187 ; 359180 ; 359162 ; 372 38 ;
Abstract
An optical signal transmitter has a laser diode, and an automatic bias current control circuit by which the relation between a light output of the laser diode, a threshold current and bias current are kept constant. The automatic bias current control circuit includes a circuit for modulating a bias current of the laser diode in amplitude with a signal of frequency f1, which is lower than that of the input signal, and a circuit for detecting the signal component of the frequency f1 included in the light output of the laser diode and controlling so as that a detected output becomes a fixed value.