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:
Mar. 16, 1999
Filed:
Jun. 25, 1997
Eisaku Akutsu, Susono, JP;
Yoshihiro Ohkuwa, Susono, JP;
Abstract
A system for detecting an object located on a travelling path even in bad weather or during nighttime in which conducting wires having a predetermined impedance value are laid along a travelling path, and a signal is supplied to the conducting wires from a signal source. If a vehicle exists on the path, the impedance of the conducting wires changes at the position where the vehicle is present. A signal reflected from the impedance change position is detected by a detector. The position of the vehicle can be determined from the timing of the received reflection signal. It is also possible to detect a vehicle changing lanes or the like by means of a plurality of conductive wires laid along the travelling path. Instead of a conducting wire, an optical fiber may be provided for determining the position of a vehicle using the refractive index change in the optical fiber due to the weight of the vehicle.