THEFT PREVENTING TAG AND THEFT PREVENTING SYSTEM

摘要

PROBLEM TO BE SOLVED: To provide a theft preventing tag which is difficult to stand out and to provide a theft preventing system using the theft preventing tag. SOLUTION: A thin film electrode 15 and a coil 11 surrounding the electrode 15 are connected in series and they are formed in the center of the surface of a transparent film 13. A thin film electrode 17 and a lead part 18 are arranged in positions confronted with the electrode 15. The lead part 18 conducts to one end of the coil 11 through a conductive material 19 in a hole passing through the film 13. A capacitor 12 is constituted by arranging the insulating film 13 between a pair of electrodes 15 and 17. The radio wave of the resonance frequency of a resonation circuit 10 is transmitted from a transmission antenna 101. A reception signal from a reception antenna 102 is compared with a transmission signal from the transmission antenna 101, and it is detected that the resonance circuit 10 comes between the transmission antenna 101 and the reception antenna 102.