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:
Feb. 22, 2005
Filed:
Mar. 01, 2002
Naoyuki Kurita, Kokubunji, JP;
Hiroshi Kondoh, Fuchu, JP;
Mikito Tsubota, Yokohama, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
In a position detecting system used to monitor a suspicious person and to give an alarm by using a radar which transmits/receives a microwave or a millimeterwave, the shape of a detectable area of the radar and that of the area to be monitored are not always equal to each other, and thus, an alarm may be erroneously given in response to the object outside the area to be monitored. For its solution, the area to be monitored is surrounded by a plurality of reflectors, and the coordinate values of the reflectors and the detecting object are calculated based on the signals reflected from the reflectors and the detecting object and then compared. When the coordinate value of the detecting object is inside the area to be monitored, it is determined that the detecting object is an intruding person or the like and an alarm is given. When the coordinate value of the detecting object is outside the area to be monitored, it is determined that the detecting object is not an intruding person or the like and no alarm is given. In addition, if the calibration and self diagnosis of the radar are periodically performed by using at least one of the reflectors, it is possible to maintain the performance of the radar in an optimal state.