| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a communication system between a non-contact IC tag and a reader/writer, and to provide the reader/writer used together with the non-contact IC tag, wherein interference can be restrained from occurring between the reader/writers by the utilization of a frequency table without giving an excessive load to the capacity of a memory in a frequency hopping system. <P>SOLUTION: The reader/writer 40 used together with the non-contact IC tag is equipped with a frequency table that stores a random frequency generation pattern for frequency hopping or a frequency table in which its frequencies are rearranged in accordance with a certain rule in the memory 30 of a control unit, and provided with a means 19 which switches the frequency hopping order from a forward to a backward direction or from a backward to a forward direction when frequency interference occurs. <P>COPYRIGHT: (C)2007,JPO&INPIT |
