MOBILE OBJECT IDENTIFICATION SYSTEM

摘要

PROBLEM TO BE SOLVED: To realize a compact and inexpensive device having a long communication distance and reducing interference with other devices. SOLUTION: An auxiliary coil 103 is arranged on the upper part of an interrogator side coil antenna 102. When a responder 104 is held on the upper part of the interrogator 101, the interrogator 101 executes communication with the responder 104 and reads out/writes data from/in the responder 104. Since the distribution of a magnetic field on the upper part of the interrogator 101 is concentrated into the position the responder 104, power to be transmitted to the responder 104 is increased and the communication distance is extended. Since magnetic flux is concentrated into the required responder 104, the magnetic field is weakened in other positions so that the influence of the magnetic field to other devices can be reduced.