| 摘要 |
<P>PROBLEM TO BE SOLVED: To suppress interference of an answer signal in a radio authentication system for use to detect many users who carry transponders having passed through an arbitrary gate among a plurality of gates disposed in parallel, wherein a plurality of interrogators transmit interrogation signals including identification information (ID) on themselves to narrow authentication areas which are previously and individually set and a transponder entering one of the authentication areas is actuated in response to the interrogation signal to return a response signal including identification information (ID) on itself, so that the respective interrogators authenticate transponders entering the respective authentication areas. <P>SOLUTION: The interrogators TX1 to TX3 intermittently transmit the interrogation signals S1 to S3 in arbitrary timing, and the transponders RX1 to RX3 having received them send back the response signals R1 to R3 immediately. Consequently, a possibility that the response signals R1 to R3 collide against one another is reduced. <P>COPYRIGHT: (C)2008,JPO&INPIT |
