COMMUNICATION STORAGE MEDIUM AND COMMUNICATION SYSTEM USING THE SAME

摘要

A communication system using a communication storage/recording medium (common card) for which different resonance frequencies can be used and a communication storage/recording medium (common card). When a common card (10) that resonates at a resonance frequency of 8.2 MHz is used by means of a reader/writer (45) that operates at a resonance frequency of 13.56 MHz, the common card (10) is placed on a resonance tag (20) having a resonance frequency different from that of the common card (10) and both are put on the reader/writer (45). The resonance frequency of the common card (10) is changed from 8.2 MHz to 13.56 MHz. The reader/writer (45) operating at a resonance frequency of 13.56 MHz reads and rewrites the content of the memory of the common card (10).