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:
May. 16, 1995
Filed:
Apr. 16, 1992
Junichi Ohta, Kanagawa, JP;
Toshinori Wakami, Kanagawa, JP;
Kazuhiro Okamoto, Kanagawa, JP;
Ryusuke Miki, Osaka, JP;
Yoshiaki Kanbe, Osaka, JP;
Sumitomo Electric Industries, Ltd., Osaka, JP;
Matsushita Electric Works, Ltd., Kadoma, JP;
Abstract
A security system, including a cable having a groove formed in the inside thereof to accommodate therein an optical fiber with an excessive length, a plurality of supports having mandrels to support the optical cable so as to provide a fence, a light transmitter to inject light into one end of the optical cable and a light receiver to detect the light projecting out of the other end of the optical cable so that any transmission loss through the optical cable due to an intrusion of the fence may be measured. The cable is formed so that when tension is applied to the optical cable, a transmission loss is detected. The resulting system has a threshold capability which distinguishes valid from false intrusions.