| 摘要 |
<p>PURPOSE:To detect even the object which cannot be detected by an RFID tag. CONSTITUTION:A tag 1 resonates to the electromagnetic wave having a specific frequency, and a transmission part 20 transmits the electromagnetic wave having this frequency. when an article 5 to which the tag 1 is attached passes between the transmission part 20 and a reception part 21, the electromagnetic wave is transmitted from the tag 1 also by resonance. Then, the level of the electromagnetic wave is raised, and the reception part 21 emits an alarm tone. A transmission part 30 generates lines of magnetic force having a high frequency. A reception part 31 emits an alarm tone when lines of magnetic force are changed by passage of metal. Thus, the tag 1 passing between gates 4 is detected or even a metallic article which cannot be detected by the tag is detected by a metal detector 3 to prevent the theft.</p> |
