| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a wireless tag communication device capable of realizing a practical security system, using a simple configuration. <P>SOLUTION: The device comprises a directivity control part 54 for controlling the directivity of communication with a radio tag 14; and a communication state change detecting part 66 for detecting change of the communication state in a predetermined area, based on a return signal from the radio tag 14 in each of the directivities provided by the directivity control part 54. Thus, it is possible to easily detect the movement of a mobile body 94 in the predetermined area, by observing the communication interference between the radio tag 14, formation of multipath and so on, caused by the movement of the mobile body 94 that acts as a radio wave shield or a radio wave reflector. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
