TAMPER INDICATING OPTICAL SECURITY DEVICE

• US 20110019283A1
• Filed: 08/12/2010
• Published: 01/27/2011
• Est. Priority Date: 11/21/2003
• Status: Active Grant

• Current Assignee: Visual Physics LLC (Crane Company)
• Original Assignee: Visual Physics LLC (Crane Company)
• Inventors: Cape, Samuel M., Hurt, Mark J., Steenblik, Richard A., Jordan, Gregory R.
• Granted Patent: US 8,773,763 B2
• Time in Patent Office: Days
• US Class Current: 359/622
• CPC Class Codes: B29D 11/00278 Lenticular sheets B29D11/00269 takes precedence
• CPC Class Codes: B29D 11/0073 Optical laminates
• CPC Class Codes: B42D 2035/20 Optical effects
• CPC Class Codes: B42D 2035/44 Miniaturised markings
• CPC Class Codes: B42D 25/21 for multiple purposes
• CPC Class Codes: B42D 25/29 Securities; Bank notes
• CPC Class Codes: B42D 25/351 Translucent or partly translucent parts, e.g. windows
• CPC Class Codes: B42D 25/373 Metallic materials
• CPC Class Codes: B42D 25/47 using adhesives
• CPC Class Codes: D21H 21/40 Agents facilitating proof of genuineness or preventing fraudulent alteration, e.g. for security paper watermarking B41M3/10, D21F1/44; security printing B41M3/14; securities or banknotes characterised by colour effects B42D25/29, B42D25/30; testing paper currency or valuable papers for genuineness G07D7/00
• CPC Class Codes: D21H 21/44 Latent security elements, i.e. detectable or becoming apparent only by use of special verification or tampering devices or methods
• CPC Class Codes: G02B 3/0031 Replication or moulding, e.g. hot embossing, UV-casting, injection moulding
• CPC Class Codes: G02B 3/0056 arranged along two different directions in a plane, e.g. honeycomb arrangement of lenses G02B3/0043 takes precedence; miniaturised objectives for electronic devices employing wafer level optics G02B13/0085
• CPC Class Codes: G02B 3/0075 characterized by non-optical structures, e.g. having integrated holding or alignment means
• CPC Class Codes: G02B 30/27 involving lenticular arrays
• CPC Class Codes: G03H 1/0256 having specific functional layer
• CPC Class Codes: G03H 2223/19 Microoptic array, e.g. lens array
• CPC Class Codes: G09F 3/0376 using a special technique to detect tampering, e.g. by ultrasonic or optical means
• CPC Class Codes: Y10T 156/1153 Temperature change for delamination [e.g., heating during delaminating, etc.]
• CPC Class Codes: Y10T 156/1158 Electromagnetic radiation applied to work for delamination [e.g., microwave, uv, ir, etc.]

Abstract

A tamper indicating optical security device that operates to produce one or more synthetic images is provided. Any attempt to detach (e.g., forcibly remove) this device from an underlying base material will cause one or more layers of the security device to separate or delaminate, rending the device partially or totally inoperable. The inventive device is contemplated for use with, among other things, currency or banknotes, secure documents such as bonds, checks, travelers checks, identification cards, lottery tickets, passports, postage stamps, and stock certificates, as well as non-secure documents such as stationery items and labels. The inventive device is also contemplated for use with consumer goods as well as bags or packaging used with consumer goods.

Claims

1. A tamper indicating security device that operates to produce one or more synthetic images, the device being adhered or bonded to a base material, wherein the device separates or delaminates when an attempt is made to detach the device from the base material, rendering the device partially or totally inoperable.

2. The tamper indicating security device of claim 1, wherein when an attempt is made to detach the device from the base material, the device no longer operates to produce one or more synthetic images.

3. The tamper indicating security device of claim 1, wherein when an attempt is made to detach the device from the base material, the device produces a reduced number of synthetic images.

4. The tamper indicating security device of claim 1, which comprises an optical film material that is made up of at least one layer containing focusing elements, at least one layer containing image elements, and at least one optical spacer or spacer layer positioned between the at least one focusing element layer and the at least one image element layer, wherein the focusing elements form one or more synthetic images of at least a portion of the image elements, wherein the security device separates or delaminates within a target layer and/or at a target interface within the security device when an attempt is made to detach the device from the base material.

5. The tamper indicating security device of claim 4, wherein (a) the cohesive strength of the target layer in the security device is less than the cohesive strength of the other layers in the security device, and/or (b) the bond strength of the target interface in the security device is less than the bond strengths of interfaces between the other layers in the security device and between the security device and the base material.

6. The tamper indicating security device of claim 1, which comprises:

(a) an optical film material comprising at least one layer containing focusing elements, at least one layer containing image elements, at least one optical spacer or spacer layer positioned between the at least one focusing element layer and the at least one image element layer, and optionally, one or more layers selected from the group of bond weakening layers, primer or adhesive layers, and combinations thereof, the at least one focusing element layer being disposed a substantially uniform distance from the at least one image element layer, with the focusing elements forming one or more synthetic images of at least a portion of the image elements; and

(b) optionally, one or more layers selected from the group of print layers, partially or totally metalized layers, primer or adhesive layers, sealing or coating layers, stiffening layers, and combinations thereof.

7. The tamper indicating security device of claim 6, wherein the at least one layer containing focusing elements is a partially or totally embedded layer.

8. The tamper indicating security device of claim 7, wherein the focusing elements of the optical film material are refractive focusing elements having a focal length, the optical film material having a refractive index from an outer surface to refracting interfaces that is varied between a first and a second refractive index, the first refractive index being substantially or measurably different than the second refractive index.

9. The tamper indicating security device of claim 8, wherein the difference between the first refractive index and the second refractive index causes a change of at least about 0.1 micron in the focal length of the focusing elements.

10. The tamper indicating security device of claim 7, wherein the at least one focusing element layer is formed from a first material having a refractive index, wherein the optical film material further comprises a second material having a different refractive index that fills interstitial spaces between and/or covers the focusing elements, a distinct interface being formed between the first and second materials.

11. The tamper indicating security device of claim 10, wherein the second material totally embeds the at least one focusing element layer.

12. The tamper indicating security device of claim 11, wherein the second material forms an outer boundary or layer of the at least one image element layer, thereby also totally embedding this layer.

13. The tamper indicating security device of claim 7, wherein the at least one focusing element layer is formed from a first material having a refractive index and a second material having a different refractive index, the second material diffusing into the first material thereby forming a gradient interface with the first material.

14. The tamper indicating security device of claim 6, wherein the focusing elements are selected from the group of refractive focusing elements, reflective focusing elements, hybrid refractive/reflective focusing elements, and combinations thereof.

15. The tamper indicating security device of claim 14, wherein the focusing elements are refractive focusing elements.

16. The tamper indicating security device of claim 14, wherein the focusing elements are reflective focusing elements or focusing reflectors.

17. The tamper indicating security device of claim 16, wherein the focusing reflectors are metalized focusing reflectors.

18. The tamper indicating security device of claim 14, wherein the focusing elements are hybrid refractive/reflective focusing elements.

19. The tamper indicating security device of claim 6, wherein the image elements are microstructures in the form of voids or recesses in a polymeric substrate, with the voids or recesses optionally filled with a contrasting substance selected from the group of dyes, coloring agents, pigments, powdered materials, inks, powdered minerals, metal materials and particles, magnetic materials and particles, magnetized materials and particles, magnetically reactive materials and particles, phosphors, liquid crystals, liquid crystal polymers, carbon black or other light absorbing materials, titanium dioxide or other light scattering materials, photonic crystals, non-linear crystals, nanoparticles, nanotubes, buckeyballs, buckeytubes, organic materials, pearlescent materials, powdered pearls, multilayer interference materials, opalescent materials, iridescent materials, low refractive index materials or powders, high refractive index materials or powders, diamond powder, structural color materials, polarizing materials, polarization rotating materials, fluorescent materials, phosphorescent materials, thermochromic materials, piezochromic materials, photochromic materials, tribolumenscent materials, electroluminescent materials, electrochromic materials, magnetochromic materials and particles, radioactive materials, radioactivatable materials, electret charge separation materials, and combinations thereof.

20. The tamper indicating security device of claim 6, wherein the image elements are microstructures in the form of raised areas or shaped posts, with regions surrounding the raised areas or shaped posts optionally filled with a contrasting substance selected from the group of dyes, coloring agents, pigments, powdered materials, inks, powdered minerals, metal materials and particles, magnetic materials and particles, magnetized materials and particles, magnetically reactive materials and particles, phosphors, liquid crystals, liquid crystal polymers, carbon black or other light absorbing materials, titanium dioxide or other light scattering materials, photonic crystals, non-linear crystals, nanoparticles, nanotubes, buckeyballs, buckeytubes, organic materials, pearlescent materials, powdered pearls, multilayer interference materials, opalescent materials, iridescent materials, low refractive index materials or powders, high refractive index materials or powders, diamond powder, structural color materials, polarizing materials, polarization rotating materials, fluorescent materials, phosphorescent materials, thermochromic materials, piezochromic materials, photochromic materials, tribolumenscent materials, electroluminescent materials, electrochromic materials, magnetochromic materials and particles, radioactive materials, radioactivatable materials, electret charge separation materials, and combinations thereof.

21. The tamper indicating security device of claim 6, wherein the at least one layer containing image elements comprises stress inducing components.

22. The tamper indicating security device of claim 6, wherein the optical film material comprises two or more focusing element layers that form two or more synthetic images, wherein when an attempt is made to detach the device from the base material, the device produces a reduced number of synthetic images.

23. The tamper indicating security device of claim 6, wherein the optical film material comprises two or more image element layers, the focusing elements forming two or more synthetic images, wherein when an attempt is made to detach the device from the base material, the device produces a reduced number of synthetic images.

24. The tamper indicating security device of claim 6, wherein the optical film material comprises one optical spacer or spacer layer located between and adhered to the at least one focusing element layer and the at least one image element layer.

25. The tamper indicating security device of claim 24, wherein separation or delamination of the security device occurs between the at least one focusing element layer and the optical spacer or spacer layer of the optical film material when an attempt is made to detach the device from the base material.

26. The tamper indicating security device of claim 24, wherein separation or delamination of the security device occurs between the optical spacer or spacer layer and the at least one image element layer of the optical film material when an attempt is made to detach the device from the base material.

27. The tamper indicating security device of claim 6, wherein the optical film material comprises two optical spacer or spacer layers that are adhered together by a primer or adhesive layer, the two optical spacer or spacer layers located between and adhered to the at least one focusing element layer and the at least one image element layer.

28. The tamper indicating security device of claim 27, wherein separation or delamination of the security device occurs between one optical spacer or spacer layer and the primer or adhesive layer of the optical film material when an attempt is made to detach the device from the base material.

29. The tamper indicating security device of claim 24, wherein the optical spacer or spacer layer is formed using one or more essentially transparent or translucent polymers selected from the group of polycarbonate, polyester, polyethylene, polyethylene napthalate, polyethylene terephthalate, polypropylene and polyvinylidene chloride.

30. The tamper indicating security device of claim 27, wherein the two optical spacer or spacer layers are formed using one or more essentially transparent or translucent polymers selected from the group of polycarbonate, polyester, polyethylene, polyethylene napthalate, polyethylene terephthalate, polypropylene and polyvinylidene chloride.

31. The tamper indicating security device of claim 27, wherein the primer or adhesive layer is formed using one or more adhesives selected from the group of hot melt adhesives, heat activatable adhesives, pressure sensitive adhesives, and polymeric laminating films.

32. The tamper indicating security device of claim 31, wherein the primer or adhesive layer is formed using a cured acrylic material.

33. The tamper indicating security device of claim 31, wherein the primer or adhesive layer is formed using a cured epoxy material.

34. The tamper indicating security device of claim 6, wherein the optical film material further comprises one or more bond weakening layers located between and adhered to at least one of the at least one focusing element layer and the at least one image element layer.

35. The tamper indicating security device of claim 34, wherein the one or more bond weakening layers is a uniform bond weakening layer.

36. The tamper indicating security device of claim 34, wherein the one or more bond weakening layers is a patterned bond weakening layer.

37. The tamper indicating security device of claim 34, wherein the one or more bond weakening layers is a metal layer.

38. The tamper indicating security device of claim 37, wherein the metal layer is a vapor deposited metal layer.

39. The tamper indicating security device of claim 34, wherein the one or more bond weakening layers is a dielectric coating.

40. The tamper indicating security device of claim 34, wherein intralayer failure is designed to occur within the one or more bond weakening layers.

41. The tamper indicating security device of claim 34, wherein interlayer failure is designed to occur between the one or more bond weakening layers and a contiguous layer.

42. The tamper indicating security device of claim 6, wherein the focusing elements are reflective focusing elements or focusing reflectors, and wherein the security device further comprises a reflective layer located on the focusing reflectors.

43. The tamper indicating security device of claim 42, wherein interlayer failure is designed to occur between the reflective layer and the focusing reflectors.

44. The tamper indicating security device of claim 6, which further comprises one or more sealing or coating layers.

45. The tamper indicating security device of claim 44, wherein the one or more sealing or coating layers is applied to the at least one image element layer of the optical film material opposite the at least one focusing element layer, the one or more sealing or coating layers having at least a portion that is transparent, translucent, tinted, pigmented, opaque, metallic, magnetic or optically variable.

46. The tamper indicating security device of claim 45, wherein the at least one sealing or coating layer is prepared using a radiation curable resin selected from the group of acrylics, epoxies, polyesters, acrylated polyesters, polypropylenes, urethanes, acrylated urethanes, and combinations thereof.

47. The tamper indicating security device of claim 44, wherein the one or more sealing or coating layers comprises stress inducing components.

48. The tamper indicating security device of claim 6, wherein one or more primer or adhesive layers form part of the optical film material and/or are applied to one or opposing sides of the security device.

49. The tamper indicating security device of claim 48, wherein the one or more primer or adhesive layers is prepared using a material selected from the group of hot melt adhesives, heat activatable adhesives, pressure sensitive adhesives, and polymeric laminating films.

50. The tamper indicating security device of claim 49, wherein the one or more primer or adhesive layers is formed using a cured acrylic material.

51. The tamper indicating security device of claim 49, wherein the one or more primer or adhesive layers is formed using a cured epoxy material.

52. The tamper indicating security device of claim 6, which further comprises one or more stiffening layers applied to the one or more image element layers of the optical film material.

53. The tamper indicating security device of claim 52, wherein the one or more stiffening layers is prepared using a multifunctional acrylate monomer or oligomer selected from the group of polyester tetraacrylate, bisphenol A epoxy diacrylate, dipropylene glycol diacrylate, and combinations thereof.

54. The tamper indicating security device of claim 52, wherein interlayer failure is designed to occur between the optical spacer or spacer layer and the at least one image element layer.

55. The tamper indicating security device of claim 6, which is in the form of a security strip, thread, patch, inlay, or overlay.

56. The tamper indicating security device of claim 6, wherein the base material is selected from the group of currency, banknotes, bonds, checks, travelers checks, identification cards, lottery tickets, passports, postage stamps, stock certificates, stationery items, labels, consumer goods, and bags or packaging used with consumer goods.

57. The tamper indicating security device of claim 56, wherein the base material is a banknote.

58. The tamper indicating security device of claim 56, wherein the base material is a passport.

59. A sheet material having opposing surfaces and comprising at least one tamper indicating security device of claim 1 mounted on a surface of, or at least partially embedded within, the sheet material.

60. A sheet material having opposing surfaces and comprising at least one tamper indicating security device of claim 6 mounted on a surface of, or at least partially embedded within, the sheet material.

61. A document made from the sheet material of claim 59.

62. A document made from the sheet material of claim 60.

63. The document of claim 61, which is selected from the group of banknotes, passports, identification cards, credit cards, and labels.

64. The document of claim 63, which comprises a banknote.

65. The document of claim 63, which comprises a passport.

66. A method for revealing or indicating tampering with a security device adhered or bonded to a base material when an attempt is made to detach the device from the base material, wherein the security device comprises an optical film material that is made up of at least one layer containing focusing elements, at least one layer containing image elements, and at least one optical spacer or spacer layer positioned between the at least one focusing element layer and the at least one image element layer, the at least one focusing element layer being disposed a substantially uniform distance from the at least one image element layer, the focusing elements forming one or more synthetic images of at least a portion of the image elements, the method comprising increasing the ability of one or more layers in the optical film material to concentrate applied or induced stress such that when an attempt is made to detach the security device from the base material, the one or more layers will separate or delaminate, rendering the security device partially or totally inoperable, thereby indicating that tampering has occurred.

67. A method for causing a security device that is adhered or bonded to a base material to separate or delaminate when an attempt is made to detach the device from the base material, wherein the security device comprises an optical film material that is made up of at least one layer containing focusing elements, at least one layer containing image elements, and at least one optical spacer or spacer layer positioned between the at least one focusing element layer and the at least one image element layer, the at least one focusing element layer being disposed a substantially uniform distance from the at least one image element layer, the focusing elements forming one or more synthetic images of at least a portion of the image elements, the method comprising one or more of the following steps:

(a) increasing or decreasing the stiffness, bond strength, or crosslink density of one or more layers or interfaces of the security device relative to remaining layers or interfaces of the security device;

(b) incorporating stress inducing components into one or more layers of the security device; and

(c) introducing a bond weakening layer at an interface between two layers of the security device.

68. The method of claim 67, wherein the stiffness and crosslink density of one or more layers of the security device is increased by (a) increasing exposure of either the security device, or one or more layers of the security device to radiation during manufacture, or (b) increasing exposure of either the security device, or one or more layers of the security device to radiation once the device is in place on a base material.

69. The method of claim 67, wherein stress inducing components are incorporated into the one or more layers of the security device, the stress inducing components being selected from the group of those components that shrink or evolve gas upon curing, those components that swell when exposed to certain liquids or gases, and those components that undergo a phase change or phase separation with a change in temperature.

70. The method of claim 69, wherein the stress inducing component is a component that shrinks or evolves gas upon curing.

71. The method of claim 70, wherein the component that shrinks or evolves gas upon curing is an expanding polyurethane foam.

72. The method of claim 69, wherein the stress inducing component is a component that swells when exposed to certain liquids or gases.

73. The method of claim 69, wherein the stress inducing component is a component that undergoes a phase change or phase separation with a change in temperature.

74. The method of claim 73, wherein the component that undergoes a phase change or phase separation with a change in temperature is an amorphous polymer that undergoes a phase change to become polycrystalline or crystalline.

75. The method of claim 69, wherein stress inducing components are incorporated into the at least one image element layer.

76. The method of claim 69, wherein the security device further comprises one or more sealing or coating layers, wherein stress inducing components are incorporated into the one or more sealing or coating layers.