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:
Nov. 27, 2007
Filed:
Oct. 18, 2005
Shizuka Ishimura, Gunma-ken, JP;
Akira Iketani, Gunma-ken, JP;
Shizuka Ishimura, Gunma-ken, JP;
Akira Iketani, Gunma-ken, JP;
Sanyo Electric Co., Ltd., Osaka, JP;
Abstract
In a position detection system, a plurality of first communication devices each comprise a transmitter for transmitting a distance-calculation signal for calculating distance to the second communication device; a detector for detecting, by receiving from the second communication device a signal corresponding to the distance-calculation signal, phase difference between the distance-calculation signal when transmitted and the signal corresponding to the distance-calculation signal when received; and a calculator for calculating the distance to the second communication device, based on the phase difference. A second communication device comprises a transmitter for transmitting the signal corresponding to the distance-calculation signal. The position detection system comprises a determining unit for determining whether the multiple distances are below a predetermined distance; and a position detector for detecting the position of a relay device corresponding to the multiple distances when the determining unit has determined that the multiple distances are at or above the predetermined distance.