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. 16, 1993
Filed:
Jun. 09, 1992
Applicant:
Inventors:
Hajime Abe, Kokubunji, JP;
Atsushi Takai, Kokubunji, JP;
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G02B / ; G02B / ;
U.S. Cl.
CPC ...
385115 ; 25022712 ; 356-5 ; 385 12 ;
Abstract
An optical transmission time measuring device for an optical transmission path includes an optical bidirectional coupler having at least two input ports and at least two output ports. A pulse light source is connected to one of the input ports of the coupler and photodetector is connected to another one of the input ports. A timing control unit is used to time the pulse light source and the photodetector. A first optical connector is connected to one of the output ports for connecting a reference optical waveguide thereto and a second optical connector is connected to another one of the output ports for connecting a measured optical waveguide thereto.