| 摘要 |
PROBLEM TO BE SOLVED: To provide a burglar preventive gate that detects a radio wave disturbed between the gates by a wireless tag attached to goods to prevent from shoplifing installed at an entrance of a shop, and that dose not harm a fashion of a shop and does not malfunction. SOLUTION: For gates 1a and 1b, transparent acrylic plates which an optical signal is passed through are used and behind the gates 1a and 1b a transmitting antenna pole 2 and a receiving antenna pole 3 made of transparent materials are stood and also the upper end of the transmitting antenna pole 2 has an inclined face 8, at the lower end of the transmitting antenna pole 2 there is a transmitter for optical signals and at the lower end of the receiving antenna pole 3 there is a receiver.
|
