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. 12, 1999
Filed:
Aug. 21, 1997
Tomohisa Ishikawa, Kawasaki, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
An optical beam splitting device which selectively disables a faulty output port to stop further emission of the optical beam therefrom. When an optical fiber cable is broken or a cable plug is disconnected, some part of the optical beam is reflected at the fiber end face that is left open. An optical sensing device, such as a photodiode, equipped in the beam splitting device receives this reflected light and transduces it into an electrical signal. A reflection detection controller examines this electrical signal and recognizes the presence of the back reflection if the electrical signal exceeds a predetermined reference level. The reflection detection controller then sends a beam control signal to an external modulator disposed at that faulty output port. With the beam control signal, the external modulator varies the intensity of the light beam so that only a limited power will be delivered to the faulty port where the back reflection is observed.