Security system label

• US 4,686,154 A
• Filed: 03/01/1984
• Issued: 08/11/1987
• Est. Priority Date: 10/20/1983
• Status: Expired due to Term

• Current Assignee: ID Security Systems Canada, Inc. (Sentry Technology Corp.)
• Original Assignee: Sigma Security Incorporated
• Inventors: Mejia, Ezequiel
• Primary Examiner(s): Lesmes, George F.
• Assistant Examiner(s): Atkinson, William M.
• Application Number:
  US06/585,074
• Time in Patent Office: 1,258 Days
• Field of Search: 428/697, 428/916, 428/900, 428/611, 428/636, 428/668, 428/686, 428/212, 428/332, 428/693, 428/692, 340/572, 340/551
• US Class Current: 428/830
• CPC Class Codes: G07F 7/086 by passive credit-cards adapted therefor, e.g. constructive particularities to avoid counterfeiting, e.g. by inclusion of a physical or chemical security-layer for security documents G07D7/00; for the reading of record-carriers in general G06K7/00; for the design of coded credit-cards G06K19/10
• CPC Class Codes: G08B 13/2411 Tag deactivation
• CPC Class Codes: G08B 13/2442 Tag materials and material properties thereof, e.g. magnetic material details
• CPC Class Codes: Y10S 428/90 Magnetic feature
• CPC Class Codes: Y10S 428/916 Fraud or tamper detecting
• CPC Class Codes: Y10S 428/928 Magnetic property
• CPC Class Codes: Y10T 428/12639 Adjacent, identical composition, components
• CPC Class Codes: Y10T 428/12861 Group VIII or IB metal-base component
• CPC Class Codes: Y10T 428/12986 Adjacent functionally defined components
• CPC Class Codes: Y10T 428/24942 including components having same physical characteristic in differing degree
• CPC Class Codes: Y10T 428/26 Web or sheet containing structurally defined element or component, the element or component having a specified physical dimension

Abstract

A security label comprised of at least two magnetically soft materials having different coercivities but similar thresholds of magnetic saturation.

Claims

1. A security label for producing pulses detectable from an applied magnetic field comprised of at least two distinct closely spaced and similarly magnetically oriented elements formed of magnetically soft materials, the elements having different coercivities but equal magnetic saturation thresholds.

2. A security label as defined in claim 1, further including short strips of a third magnetizable material having high coercivity relative to the coercivities of said magnetically soft materials and disposed in fixed spaced positions adjacent to and along at least one face of said magnetically soft materials so as to magnetically bias the magnetically soft materials into saturation when the third magnetizable material has been remanently magnetized, the two magnetically soft materials both being amorphous thin strips of the same alloy Co₆₆ Fe₄ (Mo,Si,B)₃₀, each having been differently heat-treated to obtain different coercivities but equal magnetic saturation thresholds.

3. A security label as defined in claim 2, in which each of said strips are several centimeters long, less than a centimeter wide, less than a millimeter thick, and laminated together.

4. A security label as defined in claim 1 or 2, in which one of the two materials has a shape different from the other whereby equal magnetic saturation thresholds are achieved.

5. A security label as defined in claim 1 in which each of the materials is in the form of a thin strip fixed facing and adjacent the other.

6. A security label as defined in claim 5 in which the strips are both similar materials similarly shaped, each having different coercivities.

7. A security label as defined in claim 1, 5 or 6, further including a third magnetizable material having high coercivity relative to the coercivities of said two materials fixed in adjacency to said soft magnetizable materials so as to magnetically bias the magnetically soft materials into saturation when the third magnetizable material has been remanently magnetized.

8. A security label as defined in claim 1, 5 or 6, further including short strips of a third magnetizable material having high coercivity relative to the coercivities of said magnetically soft materials desposed in fixed spaced positions adjacent to and along at least one face of said magnetically soft materials so as to magnetically bias the magnetically soft materials into saturation when the third magnetizable material has been remanently magnetized.

9. A security label as defined in claim 1, 5 or 6 in which said materials are amorphous metallic alloys.

10. A security label as defined in claim 1, 5 or 6, in which both the materials are strips of the same alloy Co₆₆ Fe₄ (Mo,Si,B)₃₀, each having been differently heat-treated to obtain different coercivities but equal magnetic saturation thresholds.