Method, system and apparatus for use in article surveillance

• US 4,686,516 A
• Filed: 08/01/1985
• Issued: 08/11/1987
• Est. Priority Date: 11/26/1984
• Status: Expired due to Term

• Current Assignee: Sensormatic Electronics Corporation (Johnson Controls International plc)
• Original Assignee: Sensormatic Electronics Corporation (Johnson Controls International plc)
• Inventors: Humphrey, Floyd B.
• Primary Examiner(s): Swann, III, Glen R.
• Application Number:
  US06/761,611
• Time in Patent Office: 740 Days
• Field of Search: 340/572, 340/551
• US Class Current: 340/572.3
• CPC Class Codes: G08B 13/2408 using ferromagnetic tags
• CPC Class Codes: G08B 13/2437 Tag layered structure, processes for making layered tags
• CPC Class Codes: G08B 13/244 Tag manufacturing, e.g. continuous manufacturing processes
• CPC Class Codes: G08B 13/2442 Tag materials and material properties thereof, e.g. magnetic material details

Abstract

An electronic surveillance system marker comprises an active component responsive to incident magnetic energy for causing an associated article surveillance system to render an output alarm and deactivatable, through change in the molecular organization of the active component, without requirement for disruption of the unitary character of the component or change in its chemical composition. The marker component is selected to be of molecularly unorganized, e.g., amorphous, matter and the deactivation step involves molecularly organizing such matter, e.g., by rendering crystalline at least a portion of the component. The amorphous matter is preferably selected to be a metal composition. The deactivation step is desirably practiced by maintaining such portion of the marker component at a temperature above the crystallization temperature of the component and thereby to crystallize a coercive force in the portion different from the coercive force in the remainder of the component. Alternatively, the marker component is selected to have retained stress which is mechanically constrained therein, the deactivation step involving the relieving of such retained mechanical stress.

Claims

1. A method for deactivating an article surveillance marker having a component responsive, in the absence of deactivation, to incident magnetic energy for causing an associated article surveillance system to render an output alarm, said method including the deactivation step of modifying the molecular organization of at least a portion of said component.

2. A method for deactivating an article surveillance marker having a component responsive, in the absence of deactivation, to incident magnetic energy for causing an associated article surveillance system to render an output alarm, said method including the step of selecting said component to be of amorphous material, and a deactivation step rendering crystalline at least a portion of said amorphous material.

3. The invention claimed in claim 2 wherein said amorphous matter is selected to exhibit large Barkhausen discontinuities prior to such deactivation.

4. The invention claimed in claim 2 wherein such deactivation step is practiced by maintaining such portion of said component at a temperature above the crystallization temperature of said component, thereby to provide a coercive force in said portion different from the coercive force in the remainder of said component.

5. The invention claimed in claim 4 wherein said deactivation step is practiced by conducting electric current through said component.

6. The invention claimed in claim 4 wherein said deactivation step is practiced by conducting electric current selectively through said component portion.

7. The invention claimed in claim 4 wherein said deactivation step is practiced by applying radiant energy to said component.

8. The invention claimed in claim 4 wherein said deactivation step is practiced in part by applying radiant energy to said component and in part by conducting electric current through said component.

9. The invention claimed in claim 8 wherein such radiant energy applying step is practiced to pre-crystallize such portion of said component.

10. An electronic surveillance system marker comprising a component responsive to incident magnetic energy for causing an associated article surveillance system to render an output alarm and deactivatable by modification of the molecular organization of at least a portion of said component.

11. An electronic surveillance system deactivatable marker comprising a component responsive to incident magnetic energy for causing an associated article surveillance system to render an output alarm wherein said component is of amorphous matter adapted to be rendered crystalline in at least a portion thereof on such deactivation.

12. The invention claimed in claim 11 wherein said amorphous matter is selected to be a metal composition.

13. An electronic article surveillance system operative with an article marker of type comprising an unitary component responsive to incident magnetic energy for causing an associated article surveillance system to render an output alarm and deactivatable by modification of the molecular organization of at least a portion of said component, said system comprising:

(a) transmitting means for establishing an alternating magnetic field in a control zone of interest;

(b) receiving means for detection in said control zone of the presence of such marker if same is not deactivated; and

(c) means for modifying the molecular organization of said marker component, thereby deactivating said marker.

14. The invention claimed in claim 13 wherein such means (c) includes means for modifying the molecular organization of a portion of said marker component.

15. An electronic article surveillance system operative with an article marker of type comprising an unitary deactivatable component responsive to incident magnetic energy for causing an associated article surveillance system to render an output alarm and deactivatable by modification of the molecular organization of at least a portion of said component, said system comprising:

(a) transmitting means for establishing an alternating magnetic field in a control zone of interest;

(b) receiving means for detection in said control zone of the presence of such marker if same is not deactivated; and

(c) means for deactivating said component comprising an electric current supply for selective electrical connection to at least a portion of said marker component to thereby deactivate said marker.

16. The invention claimed in claim 15 wherein said current supply is operable at such current level as to maintain such portion of said marker component at a temperature above the crystallization temperature of said component and thereby to crystallize a coercive force in said portion different from the coercive force in the remainder of said component.

17. An electronic article surveillance system operative with an article marker of type comprising an unitary deactivatable component responsive to incident magnetic energy for causing an associated article surveillance system to render an output alarm, said system comprising:

(a) transmitting means for establishing an alternating magnetic field in a control zone of interest;

(b) receiving means for detection in said control zone of the presence of such marker if same is not deactivated; and

(c) means for deactivating said marker component by applying radiant energy to said marker component.

18. The invention claimed in claim 17 wherein said radiant energy applying means comprises a laser.

19. The invention claimed in claim 17 wherein said radiant energy applying means comprises a source of heat.

20. An electronic surveillance system deactivatable marker comprising a component responsive to incident magnetic energy for causing an associated article surveillance system to render an output alarm wherein said component has retained mechanical stress and is adapted to be relieved of said retained mechanical stress on such deactivation.

21. An electronic article surveillance system operative with an article marker of type comprising a deactivatable component having amorphous material therein responsive to incident magnetic energy for causing an associated article surveillance system to render an output alarm, said system comprising:

(a) transmitting means for establishing an alternating magnetic field in a control zone of interest;

(b) receiving means for detection in said control zone of the presence of such marker if same is not deactivated; and

(c) means for crystallizing at least a portion of said amorphous material to alter such response of said component, thereby deactivating said marker.