Magnetomechanical EAS components integrated with a retail product or product packaging

• US 5,499,015 A
• Filed: 09/28/1994
• Issued: 03/12/1996
• Est. Priority Date: 09/28/1994
• Status: Expired due to Term

• Current Assignee: Tyco Fire & Security GmbH (Johnson Controls International plc)
• Original Assignee: Sensormatic Electronics Corporation (Johnson Controls International plc)
• Inventors: Winkler, Stephen, Witzky, Hans, Willard, Alan
• Primary Examiner(s): SWANN III, GLEN R
• Application Number:
  US08/314,087
• Time in Patent Office: 531 Days
• Field of Search: 340/551, 340/572
• US Class Current: 340/572.2
• CPC Class Codes: G08B 13/2408 using ferromagnetic tags
• CPC Class Codes: G08B 13/2445 Tag integrated into item to be protected, e.g. source tagging

Abstract

An inventory of goods is protected from theft by means of electronic article surveillance (EAS) markers integrated with items of the inventory. Each such item has a structural member in which a cavity is integrally formed. A respective magnetostrictive element is housed, free of mechanically clamping constraint, in each cavity. A respective biasing element is located adjacent to the cavity on each such item of inventory. The biasing element provides a magnetic field to bias the respective magnetostrictive element. EAS equipment is provided at a retail store where the inventory is maintained. The EAS equipment generates an alternating electromagnetic interrogation field, and when an item of inventory having the integrated EAS marker is exposed to the interrogation field, the biased magnetostrictive element is excited into mechanical resonance that is detected by the EAS equipment. Alternatively, the integrated EAS marker includes a magnetic element that provides a harmonic signal in response to the interrogation field, and a lubricant coating is provided on the magnetic element to prevent transmission of mechanical stress to the magnetic element.

Claims

1. A method of protecting an inventory of goods from theft, comprising the steps of:

(a) forming at least some items of said inventory such that each of said at least some items has a member having a cavity integrally formed in said member;

(b) housing a respective magnetostrictive element in each said cavity;

(c) providing a respective biasing element located adjacent to and outside of each said cavity, said biasing element for providing a magnetic field to bias the respective magnetostrictive element in each said cavity;

(d) generating an alternating electromagnetic field at a selected frequency, said biased magnetostrictive element being mechanically resonant when exposed to said alternating electromagnetic field; and

(e) detecting said mechanical resonance of said magnetostrictive element;

each said cavity being sized and shaped to house the respective magnetostrictive element without constraining the mechanical resonance of the magnetostrictive element.

3. A method according to claim 1, wherein the said member of said at least some of said items is a housing for defining a second cavity which encloses functional components of said at least some of said items.

4. A method according to claim 1, further comprising the step of sealing each said cavity with a respective sealing member after housing said respective magnetostrictive element in said cavity.

5. A method according to claim 4, wherein said step of providing said respective biasing element includes affixing said respective biasing element to an outer surface of said respective sealing member.

6. A method according to claim 4, wherein said step of providing said respective biasing element includes forming a magnetic layer on an outer surface of said respective sealing member and magnetically biasing said magnetic layer.

7. A method according to claim 6, wherein said forming of said magnetic layer on said outer surface of said sealing member includes a process selected from the group consisting of printing with magnetic ink, vapor deposition, electro-deposition, and sputtering.

2. A method according to claim wherein said step of providing the respective biasing element includes printing magnetic ink adjacent the respective cavity.

8. A method of manufacturing an article to be sold in a retail store, comprising the steps of:

(a) forming a member of the article so that a cavity is integrally provided in said member;

(b) housing a magnetostrictive element in said cavity; and

(c) providing a biasing element located adjacent to and outside of said cavity, said biasing element, when magnetically biased, for causing said magnetostrictive element to be mechanically resonant when exposed to an alternating electromagnetic field generated at a selected frequency by an electronic article surveillance system;

said cavity being shaped and sized to house said magnetostrictive element without constraining said mechanical resonance of said magnetostrictive element.

9. A method according to claim 8, wherein said step of providing the biasing element includes forming a magnetic layer adjacent the cavity.

10. A method according to claim 9, wherein said forming of said magnetic layer adjacent the cavity includes a process selected from the group consisting of printing with magnetic ink, vapor deposition, electro-deposition, and sputtering.

11. A method according to claim 8, wherein said member is a housing for defining a second cavity which encloses functional components of said article.

12. An article of merchandise to be protected from theft, the article comprising a member having a cavity formed integrally in said member, a magnetostrictive element housed in said cavity, and a biasing element located adjacent to and outside of said cavity, said biasing element, when magnetically biased, for causing said magnetostrictive element to be mechanically resonant when exposed to an alternating electromagnetic field generated at a selected frequency by an electronic article surveillance system, said cavity being shaped and sized to house said magnetostrictive element without constraining said mechanical resonance of said magnetostrictive element.

13. An article according to claim 12, wherein said biasing element comprises a layer of magnetic material formed adjacent to said cavity.

14. An article according to claim 13, wherein said layer of magnetic material is formed by a process selected from the group consisting of printing with magnetic ink, vapor deposition, electro-deposition, and sputtering.

15. An article according to claim 12, wherein said member is a housing for defining a second cavity which encloses functional components of said article.

16. An article according to claim 12, further comprising a sealing member positioned for sealing said cavity.

17. An article according to claim 16, wherein said biasing element comprises a layer of magnetic material formed on an outer surface of said sealing member.

18. An article according to claim 17, wherein said layer of magnetic material is formed by a process selected from the group consisting of printing with magnetic ink, vapor deposition, electro-deposition, and sputtering.

19. A magnetomechanical electronic article surveillance system for protecting an inventory of goods from theft, comprising:

(a) generating means for generating a magnetic field alternating at a selected frequency in an interrogation zone;

(b) an item of said inventory of goods, said item including a member having a cavity formed integrally in said member, a magnetostrictive element housed in said cavity, and a biasing element located adjacent to and outside of said cavity, said biasing element being magnetically biased to cause said magnetostrictive element to be mechanically resonant when exposed to said alternating field, said cavity being sized and shaped to house said magnetostrictive element without constraining said mechanical resonance of said magnetostrictive element; and

(c) detecting means for detecting said mechanical resonance of said magnetostrictive element.

20. A magnetomechanical electronic article surveillance system according to claim 19, wherein said biasing element comprises a layer of magnetic material formed adjacent to said cavity.

21. A magnetomechanical electronic article surveillance system according to claim 20, wherein said layer of magnetic material is formed by a process selected from the group consisting of printing with magnetic ink, vapor deposition, electrodeposition, and sputtering.

22. A magnetomechanical electronic article surveillance system according to claim 19, wherein said member is a housing for defining a second cavity which encloses functional components of said item of said inventory.

23. A magnetomechanical marker integrated with an article of merchandise to be protected by an electronic article surveillance system, comprising:

(a) a member of said article having a cavity integrally formed in said member;

(b) a magnetostrictive element housed in said cavity; and

(c) a biasing element located adjacent to and outside of said cavity, said biasing element, when magnetically biased, for causing said magnetostrictive element to be mechanically resonant when exposed to an alternating electromagnetic field generated at a selected frequency by said electronic article surveillance system;

said cavity being sized and shaped to house said magnetostrictive element without constraining said mechanical resonance of said magnetostrictive element.

24. An integrated marker and article of merchandise according to claim 23, wherein said biasing element comprises a layer of magnetic material formed adjacent to said cavity.

25. An integrated marker and article of merchandise according to claim 24, wherein said layer of magnetic material is formed by a process selected from the group consisting of printing with magnetic ink, vapor deposition, electro-deposition, and sputtering.

26. An integrated marker and article of merchandise according to claim 23, wherein said member of said article is a housing for defining a second cavity which encloses functional components of said article.

27. A wrapping structure for containing during shipment an article appointed for surveillance by a magnetomechanical electronic article surveillance system, comprising:

(a) a plurality of walls defining a first cavity for enclosing said article appointed for surveillance, one of said walls having a second cavity integrally formed therein;

(b) a magnetostrictive element housed in said second cavity; and

(c) a biasing element located adjacent to said second cavity, said biasing element, when magnetically biased, for causing said magnetostrictive element to be mechanically resonant when exposed to an alternating electromagnetic field generated at a selected frequency by said electronic article surveillance system;

said second cavity being sized and shaped to house said magnetostrictive element without constraining said mechanical resonance of said magnetostrictive element.

28. A wrapping structure according to claim 27, wherein said biasing element comprises a layer of magnetic material formed adjacent to said cavity.

29. A wrapping structure according to claim 28, wherein said layer of magnetic material is formed by a process selected from the group consisting of printing with magnetic ink, vapor deposition, electro-deposition, and sputtering.

30. A wrapping structure according to claim 27, further comprising a sealing member positioned for sealing said cavity.

31. A wrapping structure according to claim 30, wherein said biasing element comprises a layer of magnetic material formed on an outer surface of said sealing member.

32. A magnetomechanical electronic article surveillance system for protecting an inventory of goods from theft, comprising:

(a) generating means for generating a magnetic field alternating at a selected frequency in an interrogation zone;

(b) an item of said inventory of goods, said item including an article of merchandise and a wrapping structure for said article of merchandise, said wrapping structure including a plurality of walls defining a first cavity in which said article of merchandise is enclosed, one of said walls having a second cavity integrally formed therein, said wrapping structure also including a magnetostrictive element housed in said second cavity and a biasing element located adjacent to said second cavity, said biasing element being magnetically biased to cause said magnetostrictive element to be mechanically resonant when exposed to said alternating field, said second cavity being sized and shaped to house said magnetostrictive element without constraining said mechanical resonance of said magnetostrictive element; and

(c) detecting means for detecting said mechanical resonance of said magnetostrictive element.

33. A magnetomechanical electronic article surveillance system according to claim 32, wherein said biasing element comprises a layer of magnetic material formed adjacent to said second cavity.

34. A magnetomechanical EAS marker integrated with a packing fixture for protecting an article of merchandise from damage during shipment, comprising:

(a) a body having a first portion formed to fit a contour of said article of merchandise and a second portion formed to fit a carton in which said article is to be shipped, said body having a cavity integrally formed therein;

(b) a magnetostrictive element housed in said cavity; and

(c) a biasing element located adjacent to said cavity, said biasing element, when magnetically biased, for causing said magnetostrictive element to be mechanically resonant when exposed to an alternating electromagnetic field generated at a selected frequency by an electronic article surveillance system;

said cavity being sized and shaped to house said magnetostrictive element without constraining said mechanical resonance of said magnetostrictive element.

35. An integrated EAS marker and packing fixture according to claim 34, wherein said biasing element comprises a layer of magnetic material formed adjacent to said cavity.

36. An integrated EAS marker and packing fixture according to claim 35, wherein said layer of magnetic material is formed by a process selected from the group consisting of printing with magnetic ink, vapor deposition, electro-deposition, and sputtering.

37. An integrated EAS marker and packing fixture according to claim 36, wherein said body is formed of molded plastic foam.

38. A magnetomechanical electronic article surveillance system for protecting an inventory of goods from theft, comprising:

(a) generating means for generating a magnetic field alternating at a selected frequency in an interrogation zone;

(b) an item of said inventory of goods, said item including a packing fixture, an article of merchandise supported in said packing fixture, and a carton containing said packing fixture and said article of merchandise, said packing fixture including a body having a first portion formed to fit a contour of said article of merchandise and a second portion formed to fit said carton, said body having a cavity integrally formed therein, said packing fixture also including a magnetostrictive element housed in said cavity and a biasing element located adjacent to said cavity, said biasing element being magnetically biased to cause said magnetostrictive element to be mechanically resonant when exposed to said alternating field, said cavity being sized and shaped to house said magnetostrictive element without constraining said mechanical resonance of said magnetostrictive element; and

(c) detecting means for detecting said mechanical resonance of said magnetostrictive element.

39. A magnetomechanical electronic article surveillance system according to claim 38, wherein said biasing element comprises a layer of magnetic material formed adjacent to said cavity.

40. A magnetomechanical electronic article surveillance system according to claim 38, wherein said body of said packing fixture is formed of molded plastic foam.

41. A method of verifying the authenticity of an article of merchandise, comprising the steps of:

forming a magnetic element that is a magnetostrictive element selected to provide a signal that is detectable by a magnetomechanical electronic article surveillance system;

integrating said magnetic element into said article of merchandise by forming a member of the article so that a cavity is integrally provided in said member, housing the magnetic element in said cavity, and providing a biasing element located adjacent to and outside of said cavity, said biasing element when magnetically biased, for causing said magnetic element to be mechanically resonant when exposed to an alternating electromagnetic field generated at a selected frequency by said magnetomechanical electronic article surveillance system, said cavity being shaped and sized to house said magnetic element without constraining said mechanical resonance of said magnetic element; and

detecting the presence of said magnetic element integrated in said article of merchandise.

42. A method according to claim 41, wherein said detecting step includes exposing said article of merchandise to an interrogation signal and detecting a response signal generated by said magnetic element in response to said interrogation signal.

43. A method according to claim 41, wherein said detecting step includes visual inspection of said article of merchandise.

44. A method of verifying the authenticity of an article of merchandise, comprising the steps of:

forming a magnetic element selected to provide a signal that is detectable by an electronic article surveillance system which generates an interrogation signal at a predetermined frequency, said magnetic element responding to said interrogation signal by generating a response signal that includes substantial harmonics of said predetermined frequency;

providing a lubricant coating on said magnetic element;

embedding said magnetic element With said lubricant coating directly into a member of said article of merchandise by forming said member of a material molded around said magnetic element with said lubricant coating; and

detecting the presence of said magnetic element embedded in said article of merchandise.

45. A method according to claim 44, wherein said material molded around said magnetic element is plastic.

46. An article of merchandise to be protected from theft, the article comprising a member formed of a molded material having directly embedded therein a magnetic element selected to provide a signal that is detectable by an electronic article surveillance system, said magnetic element having a lubricant coating thereon for limiting transmission of mechanical stress from said member to said magnetic element.

47. An article according to claim 46, wherein said molded material is plastic.

48. An article according to claim 46, wherein said magnetic element is selected to respond to an alternating EAS interrogation signal by generating a signal pulse which includes harmonics of the interrogation signal.

49. An article according to claim 46, wherein said member in which said magnetic element is embedded is a housing for defining a cavity which encloses functional components of said article.

50. A method of manufacturing an article to be sold in a retail store, comprising the steps of:

forming a magnetic element selected to provide a signal that is detectable by an electronic article surveillance system;

providing a lubricant coating on said magnetic element; and

embedding said magnetic element with said lubricant coating directly into a member of said article by forming said member of a material molded around said magnetic element with said lubricant coating.

51. A method according to claim 50, wherein said material molded around said magnetic element is plastic.

52. A method according to claim 50, wherein said magnetic element is selected to respond to an alternating EAS interrogation signal by generating a signal pulse which includes harmonics of the interrogation signal.

53. A method according to claim 50, wherein said member in which said magnetic element is embedded is a housing for defining a cavity which encloses functional components of said article.

54. An electronic article surveillance system for protecting an inventory of goods from theft, comprising:

(a) generating means for generating a magnetic field alternating at a selected frequency in an interrogation zone;

(b) an item of said inventory of goods, said item including a member formed of a molded material and having embedded directly therein a magnetic element having a lubricant coating for limiting transmission of mechanical stress from said member to said magnetic element, said magnetic element being selected to provide a signal that is detectable by said electronic article surveillance system; and

(c) detecting means for detecting harmonic signals generated by said magnetic element in response to said alternating magnetic field.

55. An electronic article surveillance system according to claim 54, wherein said molded material is plastic.

56. An electronic article surveillance system according to claim 54, wherein said magnetic element, upon exposure to said magnetic field generated by said generating means, generates a signal pulse which includes harmonics of said selected frequency.

57. An electronic article surveillance system according to claim 54, wherein said member in which said magnetic element is embedded is a housing for defining a cavity which encloses functional components of said article.

58. A wrapping structure for containing during shipment an article appointed for surveillance by an electronic article surveillance system, comprising:

(a) a plurality of walls defining a first cavity for enclosing said article appointed for surveillance;

(b) a magnetic element selected to provide a signal that is detectable by said electronic article surveillance system and incorporated into one of said plurality of walls; and

(c) means for limiting transmission of mechanical stress from said one of said plurality of walls to said magnetic element.

59. A wrapping structure according to claim 58, wherein said means for limiting transmission of mechanical stress comprises a lubricant coating on said magnetic element.

60. A wrapping structure according to claim 58, wherein said means for limiting transmission of mechanical stress comprises a second cavity integrally formed in said one of said plurality of walls and shaped and sized to house said magnetic element therein so that said magnetic element is permitted to move within said second cavity.

61. An EAS marker integrated with a packing fixture for protecting an article of merchandise from damage during shipment, comprising:

(a) a body having a first portion formed to fit a contour of said article of merchandise and a second portion formed to fit a carton in which said article is to be shipped;

(b) a magnetic element selected to provide a signal that is detectable by said electronic article surveillance system and incorporated into said body; and

(c) means for limiting transmission of mechanical stress from said body to said magnetic element.

62. An integrated EAS marker and packing fixture according to claim 61, wherein said means for limiting transmission of mechanical stress comprises a lubricant coating on said magnetic element.

63. An integrated EAS marker and packing fixture according to claim 61, wherein said means for limiting transmission of mechanical stress comprises a cavity integrally formed in said body and shaped and sized to house said magnetic element therein so that said magnetic element is permitted to move within said cavity.

64. An article of merchandise to be protected from theft, the article comprising:

a member having a cavity formed integrally in said member, said cavity being defined by walls formed integrally in said member and by a first surface of a sealing member;

a magnetostrictive element housed in said cavity; and

a biasing element applied on a second surface of said sealing member, said biasing element, when magnetically biased, for causing said magnetostrictive element to be mechanically resonant when exposed to an electromagnetic field generated at a selected frequency by an electronic article surveillance system,

said cavity being shaped and sized to house said magnetostrictive element without constraining said mechanical resonance of said magnetostrictive element.

65. An article according to claim 64, wherein said biasing element comprises a layer of magnetic material formed on said second surface of said sealing member.

66. An article according to claim 64, wherein said member is a housing for defining a second cavity which encloses functional components of said article.