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:
Sep. 07, 1999
Filed:
Nov. 21, 1997
Applicant:
Inventors:
Assignee:
Hitachi Cable, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G02B / ;
U.S. Cl.
CPC ...
385 14 ; 385 45 ;
Abstract
An optical filter is provided to be on a side of the output ports relative to a branch port of the first stage in an optical branch apparatus. The optical filter transmits a signal light and reflects a monitor light, so that signal lights are obtained at output ports, and the monitor light is returned to an optical transmitter to detect an abnormal state of an optical fiber transmission line.