INFORMATION ACCESS SYSTEM, ACTIVE TYPE NON-CONTACT INFORMATION STORAGE DEVICE, AND METHOD FOR ACCESSING INFORMATION IN NON-CONTACT INFORMATION STORAGE DEVICE

摘要

PROBLEM TO BE SOLVED: To reduce a possibility of interference among a plurality of reader/writer devices.

SOLUTION: In the information access system, a first reader/writer device (302) periodically iteratively transmits an information request signal of a first frequency (f1) during a first term (t1) and falls into inactive state in a second term (t2), and a second reader/writer device (304) periodically iteratively transmits the information request signal of the first frequency during the second term and falls into inactive state in the first term. A non-contact information storage device (202) performs carrier sensing on an RF signal of the first frequency during a predetermined period in a predetermined cycle (Ts) shorter than the first and second terms.

COPYRIGHT: (C)2008,JPO&INPIT