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. 24, 2009
Filed:
Jul. 21, 2004
Makoto Takakuwa, Kawasaki, JP;
Futoshi Izumi, Kawasaki, JP;
Masahiro Yoshimoto, Kawasaki, JP;
Takahiro Hosokawa, Kawasaki, JP;
Makoto Takakuwa, Kawasaki, JP;
Futoshi Izumi, Kawasaki, JP;
Masahiro Yoshimoto, Kawasaki, JP;
Takahiro Hosokawa, Kawasaki, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
A power-down delay unit for delaying cutoff of a voltage is provided in a power supply line which supplies electrical power to an optical module of a transponder unit for each optical wavelength. The power-down delay unit assigns different delays for each wavelength. The length of the delay is a time required by an AMP unit to change from an ALC mode to an AGC mode or longer. When the power sources for supplying electrical power to the transponder units becomes faulty and outputs of several wavelengths are simultaneously going to stop, the power-down delay unit delays cutoff of the supply voltage to the optical modules by keeping supply voltage for a while to the optical modules on behalf of power sources enabling the optical modules to operate after the power sources shutdown, so that the actual optical signals gradually stop one by one.