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. 08, 2002
Filed:
Jul. 19, 2000
Hideaki Tsushima, Komae, JP;
Masahiro Ojima, Tokyo, JP;
Masaya Horino, Niihari, JP;
Kazutaka Sato, Kashiwa, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A light emitted from the supervisory light source is supplied to the input port of any one of a plurality of switching sections provided in the optical switching device. A light emitted from the output port of the switching section is converted into electric signals and then compared with the threshold value by a supervisory receiver. The supervisory control circuit discriminates the state of connection at each switching section in the optical switching device according to the compared result obtained by the supervisory receiver, whereby each switching section in the optical switching device is supervised.