| US 7,602,293 B2 | ||
| Interrogator for RFID tag | ||
| Kazunari Taki, Nagoya (Japan); Tsuyoshi Ohashi, Hashima (Japan); Takuya Nagai, Nagoya (Japan); and Kentaro Ushiyama, Nagoya (Japan) | ||
| Assigned to Brother Kogyo Kabushiki Kaisha, Nagoya-shi, Aichi-ken (Japan) | ||
| Filed on Dec. 15, 2006, as Appl. No. 11/611,468. | ||
| Application 11/611468 is a continuation in part of application No. PCT/JP2005/010776, filed on Jun. 13, 2005. | ||
| Claims priority of application No. 2004-176411 (JP), filed on Jun. 15, 2004. | ||
| Prior Publication US 2007/0080787 A1, Apr. 12, 2007 | ||
| Int. Cl. G08B 13/14 (2006.01) | ||
| U.S. Cl. 340—572.1 [340/572.4; 340/572.7] | 14 Claims |
| 1. An interrogator for a RFID tag communication system, comprising:
a plurality of antenna elements configured to perform information communication in a non-contact manner with an IC circuit
part of a RFID circuit element to be interrogated; and
a directivity control portion configured to control a directivity of said plurality of antenna elements in accordance with
at least a communication distance of said information communication, wherein:
said directivity control portion comprises a direction switching portion configured to retain said directivity of said plurality
of antenna elements so as to be strong in only one direction while sequentially changing the direction with respect to which
the directivity is made strong, and
said direction switching portion makes an angular interval for switching said direction of directivity that is to be sequentially
changed large when said communication distance is short, and makes the angular interval for switching said direction of directivity
that is to be sequentially changed small when said communication distance is long.
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