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. 01, 1994
Filed:
Aug. 25, 1992
Tadasu Ishikawa, Tokyo, JP;
Mikio Maeda, Tokyo, JP;
Kimiyuki Oyamada, Tokyo, JP;
Shuichi Fujisawa, Tokyo, JP;
Yozo Utsumi, Tokyo, JP;
Kunihara Takizawa, Tokyo, JP;
Nippon Hoso Kyokai, Tokyo, JP;
Abstract
A bidirectional light transmission system comprises a transmitting station having a light source for intensity-modulating a transmission signal, a first light branching portion for branching intensity-modulated light of the light source in a predetermined ratio and a first light receiving portion, and a receiving station having a second light branching portion, a light phase-modulating portion, a light reflecting portion and a second light receiving portion. The transmitting station transmits the intensity-modulated light via a single optical fiber transmission line to the receiving station connected thereto and receives a returned signal returned from the receiving station via the single optical fiber transmission line in the first light receiving portion, and the receiving station branches the transmitted light into first branched light and second branched light in the second light branching portion, phase-modulates at least one of the first branched light and second branched light in the light phase-modulating portion, transmits part of the first branched light and second branched light to the second light receiving portion via the light reflecting portion and simultaneously intensity-modulates reflected part of the first branched light and second branched light as a returned signal in the light phase-modulating portion and the second light branching portion, and returns the returned signal to the transmitting station via the single optical fiber transmission line.