ELECTRONIC ARTICLE SUPERVISORY EQUIPMENT WITH HIGH TAG-INACTIVATION FUNCTION

摘要

PROBLEM TO BE SOLVED: To provide a magnetic angular momentum marker which does not generate a harmonic signal with a substantial amplitude in response to calling by a harmonic EAS system at the time of being inactivated. SOLUTION: The marker 10 used for a magnetic angular momentum electronic article supervisory(EAS) system is generated by placing a magnetostriction element 12 near a bias element 16 within a housing 14, and the bias element 16 is magnetized to an extent lower than saturation. The resonance frequency of the marker 10 is detected. When the detected resonance frequency does not coincide with the already fixed operation frequency of EAS, the intensity of the magnetizing of the bias element 16 is adjusted to make the resonance frequency of the marker 10 with the already fixed operation frequency.