| 摘要 |
<P>PROBLEM TO BE SOLVED: To make a stable communication even if a variance exists in a resonance frequency on a production. <P>SOLUTION: A communication device (noncontact IC card) changes the resonance frequency in response to a distance between the communication device and an external device (reader/writer device). The resonance frequency is changed on the communication device side, so that a dead zone is evaded. For example, even if the manufactured noncontact IC card carries the resonance frequency in which the dead zone occurs in the vicinity of a proximity distance, the resonance frequency is changed to one which evades the dead zone in response to a distance, so that an uncommunicable distance does not generate at a proximity position. <P>COPYRIGHT: (C)2009,JPO&INPIT |
