| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To reduce probability of mutual interference among a plurality of readers/writers. <P>SOLUTION: An active non-contact information storage device (204), in an information access system, performs the carrier sense of the RF signal (f<SB>11</SB>) of a first frequency in a first prescribed period by each prescribed cycle and performs the carrier sense of the RF signal (f<SB>12</SB>) of a second frequency in a second prescribed period by each prescribed cycle. When the carrier sense of the RF signal of either the first or the second frequency is performed in a certain prescribed period so as to detect the signal, the non-contact information storage device further receives an ID request signal and transmits the response signal of one corresponding frequency between the third and the fourth frequencies including the ID of the non-contact information storage device stored in a memory, in response to the ID request signal. <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
