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:
Jan. 13, 2004
Filed:
Sep. 22, 1998
Junichi Matsuda, Tokyo, JP;
Shuntaro Yamazaki, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
In a spatial transmission optical transceiver, signals of two lines from a feeder-affixed twisted pair line which is a data transmission line based on IEEE1394 standard are converted to signals of one line by a code conversion circuit , and further converted to optical signals and emitted to space by a optical transmitter . The optical signal transmitted through the space is converted to an electrical signal by a optical receiver . The code conversion circuit receiving the electrical signal of one line thus converted to signals of two lines, and transmits the signals onto the feeder-affixed twisted pair line . The electrical signal from the optical receiver is input to an interception and insertion/removal detection circuit to detect the presence or absence of the optical signal and judge whether the received signal is a reflection signal, thereby detecting the interception of a communication path and the insertion/removal of a signal line connected to a confronting optical transceiver. The detection result is transmitted to a bias circuit , and when no optical signal is received or the reception signal is the reflection signal, the bias circuit stops the bias voltage application to the feeder-affixed twisted pair line