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. 18, 2001
Filed:
Nov. 18, 1998
Noritaka Egami, Tokyo, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
A band pass filter,for detecting a component in the vicinity of a frequency (1 kHz) having the highest propagation efficiency among oscillations generated when a train runs, a band pass filter,for detecting a component in the vicinity a frequency (5.5 kHz) having the lowest propagation efficiency and a microcomputer,are provided, the microcomputer,being arranged to determine a state in which the train has approached a relatively near location, a state in which the train has approached a very near location, a state in which the train has passed through and exists at a very near location or a state in which the train exists at a relatively near location. A conventional track circuit must, as a matter of course, have insulating portions for rails and incorporate a signal cable for communicating a result of the detection, causing the cost to be enlarged. The present invention is able to eliminate the foregoing necessities and reduce the cost.