To make examinable electric characteristics with high reliability at a high speed and to make improvable the efficiency of IC card issuing by contactlessly and magnetically detecting current characteristics received at an antenna part on the basis of electromagnetic waves.
While controlling an oscillator 303, a magnetic flux is generated from an antenna 301 for transmission while being changed between frequencies f1-f2 including a power transmission frequency f0. A voltage induced by the magnetic flux generated on the basis of a current flowing to the antenna of the IC card as an object to be examined at the frequencies f1, f0 and f2 is detected by a coil 401 for detection and preserved in respective hold circuits 404a, 404b and 404c. Resonance frequency characteristics on the side of the resonance frequencies f1 and f2 of the IC card as the object to be examined are examined by comparator circuits 403a and 403b, the outputs of the comparator circuits 403a and 403b are ANDed by an AND circuit 405 and it is examined whether the maximum value of the antenna current value exists or not. The output of the hold circuit 404b is compared with a set voltage by a comparator circuit 403c and the characteristics of a connection between the antenna and an IC chip or the like are examined.
SUGA TAKU
YOSHINO RYOZO
| JPH10288643A | 1998-10-27 | |||
| JPH0991391A | 1997-04-04 | |||
| JPH11353433A | 1999-12-24 | |||
| JPH0526938A | 1993-02-05 |
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