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. 14, 1997
Filed:
Feb. 28, 1995
Gan Oda, Kawasaki, JP;
Tomohisa Ishikawa, Kawasaki, JP;
Yoshimitsu Sakai, Sapporo, JP;
Akira Okamoto, Kawasaki, JP;
Tatsuro Kunikane, Kawasaki, JP;
Tetsuo Watanabe, Kawasaki, JP;
Sadayuki Miyata, Kawasaki, JP;
Hiroyuki Furukawa, Sapporo, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
A compact, low-cost combined transmitting/receiving optical communications module, which is suitable for use in a TCM system and which is capable of normal operation over a particularly wide temperature range in optical communications equipment, is provided. The optical transmitting/receiving section for this purpose has a laser diode which outputs a transmitted optical signal, a combined monitor/receiving photodiode which not only monitors the optical output signal from the laser diode during a transmitting period, but also receives the input optical signal from the transmission path during the receiving period, and an optical mixer/divider which performs transmitting/receiving mixing and dividing between the transmission path, the laser diode, and the photodiode. A drive section has a transmitting/receiving switching circuit which performs time-division transmitting/receiving switching and a threshold control circuit which performs successive control of the bias current of the laser diode so that the optical noise output monitored by the photodiode is maximized.