Magnetomechanical article surveillance marker with a tunable resonant frequency
Patent 5495230 Issued on February 27, 1996. Estimated Expiration Date: 
August 10, 2014. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
August 10, 2014. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 2792532 3747086 Surveillance system having magnetomechanical marker Selector for AC magnetic inductive field receiver coils Heat treatment process and soft magnetic alloys produced thereby Patent #: 5252144 InventorAssigneeApplicationNo. 288556 filed on 08/10/1994US Classes:340/572.1, Detectable device on protected article (e.g., "tag")340/551, Disturbance of magnetic field340/572.3, Deactivatable by means other than mere removal361/143, Systems for magnetizing, demagnetizing, or controlling the magnetic field361/149DemagnetizingExaminersPrimary: Swann, GlenAttorney, Agent or FirmInternational ClassG08B 013/24AbstractA marker for use in a magnetomechanical electronic article surveillance (EAS) system is made by mounting a magnetostrictive element in a housing adjacent to a biasing element that is magnetized to a degree of magnetization that is less than saturation. The resonant frequency of the marker is detected. If the detected resonant frequency does not match a predetermined operating frequency of the EAS system, the degree of magnetization of the biasing element is adjusted so as to tune the resonant frequency of the marker to the predetermined operating frequency. | |
