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. 15, 1991
Filed:
Nov. 08, 1989
Kazuyoshi Shimizu, Yokohama, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
Disclosed is a bidirectional optical transmission system for effecting bidirectional optical transmission between offices by utilizing a common optical transmission line. Each office comprising: a light transmitting unit for transmitting a light signal to another office; a light receiving unit for receiving a signal from the other office; and a light passing unit for passing the transmission signal from the light transmitting unit to the optical transmission line and for passing the receiving signal from the optical transmission line to the light receiving unit. To discriminate whether the received signal is the signal from the other office or from the same office by crosstalk through the light passing unit, the light transmitting unit comprises a light-interruption detecting signal superimposing unit for superimposing a light-interruption detecting signal on the transmission signal, the frequencies of the light-interruption detecting signals from the first office and from the other office being different from each other; and the light receiving unit comprises a light-interruption detecting signal detecting unit for detecting the light-interruption detecting signal from the other office by identifying the frequency of the light-interruption detecting signal from the other office.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile