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. 26, 1999
Filed:
Nov. 06, 1997
Applicant:
Inventor:
Toshiro Yoshida, Tokyo, JP;
Assignee:
NEC Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01S / ;
U.S. Cl.
CPC ...
372 38 ; 372 29 ; 372 31 ;
Abstract
In the apparatus for driving a laser diode, a light receiving element detects a light output level of the laser diode to produce an electric signal. That is, the light receiving element detects a first electric signal when the laser diode is driven based upon an ON signal, and a second electric signal when the laser diode is driven based upon an OFF signal. A control circuit outputs a control signal in response to the signal. A driving circuit drives the laser diode in response to the control signal such that a difference between the first electric signal and the second electric signal is maintained at a constant value.