| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an access control system in which, when one antenna coil is driven and the other is not driven, probability of exerting adverse influence on each other is eliminated. <P>SOLUTION: One of two antenna coils is arranged behind the other at an entrance path, connected to a reader (20) to form oscillation circuits (30, 31). Either of oscillation circuits (30, 31) including first antenna coils (12, 13) in the entrance direction or the other oscillation circuits including second antenna coils are driven by the reader (20) in order to read data for the purpose of access permission from a transponder having a transponder coil held by a user. The oscillation circuits (30, 31) which are not driven by the reader (20) are detuned or short-circuited. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
