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:
Jun. 10, 2008
Filed:
Jan. 23, 2006
Norihiko Shibata, Chigasaki, JP;
Fumiaki Tsuchiya, Ichikawa, JP;
Toshihiro Nozawa, Hitachi, JP;
Shinya Ishi, Hitachi, JP;
Norihiko Shibata, Chigasaki, JP;
Fumiaki Tsuchiya, Ichikawa, JP;
Toshihiro Nozawa, Hitachi, JP;
Shinya Ishi, Hitachi, JP;
Sanki Eng., Co., Ltd., Tokyo, JP;
Abstract
Intrusion by climbing or jumping over a fence can be detected, and intrusion is detected in a wide area without large-scale equipment. FBGs (grating sections) of different types having different refractive indexes of fiber glass are arranged at predetermined intervals in a longitudinal direction of optical fibersA, andB, the optical fibers are laid down between poles on the top of a fence or a side thereof, reflected waves from the FBGs are issued by photodetection devicesA, andB in response to an optical input to the optical fibers, and a wavelength shift detection devicedetects a position of an FBG which exhibits a wavelength shift by swinging of the optical fibers by a stress acting on the fence. A pattern recognition devicefetches positions of the wavelength-shifted FBGs as differences between timings of the pulse signals and discriminates swinging of the fence caused by intrusion from swinging of the fence caused by other factors on the basis of output patterns of the pulse signals.