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:
Nov. 02, 1999
Filed:
Jan. 02, 1997
Kenichi Nomura, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
A light transmitting circuit of a light wave length multiplexing apparatus comprises a LD module 2 including a semi-conductor laser device, a temperature control circuit 3 and a driving current generating circuit for providing the semi-conductor laser device with a driving current. A temperature control circuit 3 generates a temperature error signal, when the difference between a temperature monitor signal and a temperature set signal is too great, that is, while the wave length is not normal. The temperature error signal is input to a LD driver 1, a bias circuit 4 or a light amplifier 6, and the light output signal stops. The light transmitting circuit has no influence on the output signal of the light transmitting circuit of a remaining wavelength for the light wave length multiplexing operation, when the temperature of the semi-conductor laser device differs significantly the temperature set value because of the set-up process or a failure.