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:
Aug. 30, 2011
Filed:
Feb. 07, 2008
Yasuhiro Uchiyama, Yokohama, JP;
Yukio Hayashi, Yokohama, JP;
Chanthan Winh, Yokohama, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
There is provided a shutdown controller that monitors the temperature of an optical multiplexer and maximizes the loss of an optical attenuator when a temperature monitor result is abnormal. An optical level change detection circuit section is disposed with respect to an optical level monitor of individual monitors in an optical add/drop multiplexer. An optical level monitor of a total main signal is disposed downstream of the optical multiplexer. The inconsistency of the wavelength number is detected by comparing the total of the optical level monitors of the individual channels with the optical level value of the optical level monitor, upon which shutdown control is performed in which the loss of the optical attenuator is maximized in only the channel whose optical level change is detected by the optical level change detection circuit section.