NONCONTACT TYPE INFORMATION STORAGE MEDIUM AND ITS ISSUE DEVICE, EXTERNAL COMMUNICATION DEVICE AND COMMUNICATION METHOD OF THE STORAGE MEDIUM

摘要

PROBLEM TO BE SOLVED: To provide a noncontact type information storage medium which can perform the long-distance communication with no adjustment required among resonance frequencies of plural media even when they are put on each other and also to provide an issue device of the information storage medium, an external communication device and a communication method of the information storage medium. SOLUTION: The resonance frequency is previously stored in a resonance frequency storage circuit contained in an IC chip 13 of a contactless IC card 10 when the card 10 is issued. When the card 10 is used, an R/W 20 reads out the resonance frequency when the communication is started and sets communication electromagnetic frequency at the resonance frequency via a voltage controlled oscillation circuit 25. Thus, the communication is possible with the R/W 20 by means of the resonance frequency of the card 10 and with no adjustment of this frequency by adjusting the capacity of a capacitor 12 of the card 10. As a result, a long communication distance is secured.