Surveillance marker and method of making same

• US 5,401,584 A
• Filed: 09/10/1993
• Issued: 03/28/1995
• Est. Priority Date: 09/10/1993
• Status: Expired due to Term

• Current Assignee: Knogo North America, Inc. (Sentry Technology Corp.)
• Original Assignee: Knogo Corp (Johnson Controls International plc)
• Inventors: Solaski, Thomas P., Minasy, Arthur J., Zhou, Peter Y., Callaghan, Edward J.
• Primary Examiner(s): Ryan, Patrick J.
• Assistant Examiner(s): LAM, CATHY FONG FONG
• Application Number:
  US08/118,723
• Time in Patent Office: 564 Days
• Field of Search: 340/551, 340/572, 428/611, 428/615
• US Class Current: 428/611
• CPC Class Codes: G08B 13/2411 Tag deactivation
• 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
• CPC Class Codes: G08B 13/2445 Tag integrated into item to be protected, e.g. source tagging
• CPC Class Codes: Y10T 428/12465 having magnetic properties, or preformed fiber orientation coordinate with shape
• CPC Class Codes: Y10T 428/12493 Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]

Abstract

A deactivatable electronic theft detection marker is made from a strip or ribbon of high magnetic permeability strip or ribbon and then high magnetic coercivity material is deposited on the strip or ribbon by electroplating.

Claims

1. A deactivatable electronic article surveillance system marker comprising:

an element of easily magnetizable material having high magnetic permeability and low magnetic coercivity such that said material, when subjected to continuous alternating magnetic interrogation fields, will produce characteristic detectable disturbances of those fields; and

another magnetizable material which has a higher magnetic coercivity than the material of said element, said another magnetizable material being in direct contact with said element on an atom by atom basis, the interface between said magnetic materials being essentially free of any other materials.

2. A deactivatable marker according to claim 1, wherein said another material is electroplated onto the surface of said element.

3. A deactivatable marker according to claim 1, wherein said another material is vacuum deposited onto the surface of said element.

4. A deactivatable marker according to claim 1, wherein said another material is sputtered onto the surface of said element.

5. A deactivatable marker according to claim 1, wherein said another material is arranged at spaced apart locations along said element.

6. A deactivatable marker according to claim 1, wherein said element is a portion of an elongated strip of said high permeability material and wherein said another material is deposited onto said strip.

7. A deactivatable marker according to claim 1, wherein said element is a ring shaped member and wherein said another material is deposited at discrete spaced apart locations around said member.