| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a reader/writer for a non-contact type IC card for achieving data communication with an IC card even if it is not possible to communicate data with a non-contact type IC card located at a specific communication position. <P>SOLUTION: A CPU section 20 first makes communication via a first antenna coil 13a when communication with an IC card 4 located at a specific communication position. In this case, when it is not possible to communicate with the IC card 4, an antenna selection section 14 is switched to execute communication with the IC card 4 via a second antenna coil 13b. If the communication is disabled, communication with the IC card 4 is executed through a third antenna coil 13c. As a result, a communication feature by an antenna coil 13 is successively switched, thus returning a resonance frequence to its original state even if the resonance frequency is affected by ambient environment and deviates from a target resonance frequency. <P>COPYRIGHT: (C)2003,JPO |
