Antipilferage system and marker therefor
Patent 3938125 Issued on February 10, 1976. Estimated Expiration Date: 
February 10, 1993. 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.
February 10, 1993. 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 ReferencesInventorApplicationNo. 443954 filed on 02/20/1974US Classes:340/572.3, Deactivatable by means other than mere removal340/572.4, Specified processing arrangement for detected signal340/572.6, Having "soft" magnetic element (e.g., Permalloy)428/601, Discontinuous surface component428/652, Next to Group VIII or IB metal-base component428/653, Fe428/686, Adjacent functionally defined components428/900, MAGNETIC FEATURE428/92Particular shape or structure of pileExaminersPrimary: Trafton, David L.Attorney, Agent or FirmInternational ClassG08B 13/24 (20060101)AbstractAn antipilferage system utilizing markers comprising a sheet having both ferromagnetic and electrically conductive characteristics, which markers are detected upon passage through an interrogation zone within which are sequentially generated magnetic fields orthogonally disposed with respect to each other. The marker sheet is preferably a laminate of a ferromagnetic layer and a conductive metal layer, each of which layers exhibits a maximum sensitivity to fields perpendicular to each other. Interrogation of the markers by fields in three dimensions ensures the production of signal components associated with both characteristics of the marker regardless of the orientation of the marker upon passage through the zone. Accordingly, a highly reliable and false alarm free system is provided. | |
