Optical system demonstrating improved resistance to optically degrading external effects

• US 8,867,134 B2
• Filed: 06/22/2010
• Issued: 10/21/2014
• Est. Priority Date: 11/21/2003
• Status: Active Grant

• Current Assignee: Visual Physics LLC (Crane Company)
• Original Assignee: Visual Physics LLC (Crane Company)
• Inventors: Hurt, Mark J., Cape, Samuel M., Jordan, Gregory R., Steenblik, Richard A.
• Primary Examiner(s): Harrington, Alicia M
• Application Number:
  US12/820,320
• Publication Number:
  US 20100308571A1
• Time in Patent Office: 1,582 Days
• Field of Search: 359618-626
• US Class Current: 359/619
• CPC Class Codes: B42D 15/0073 characterised by shape or material of the sheets
• 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 25/324 Reliefs
• CPC Class Codes: B42D 25/355 Security threads
• 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 30/27 involving lenticular arrays

Abstract

A system for projecting one or more synthetic optical images, which demonstrates improved resistance to optically degrading external effects, is provided. The inventive system serves to lock the focal length of the focusing elements in place. In other words, no other transparent materials or layers brought into contact with the inventive system will serve to materially alter the focal length or the optical acuity of synthetic images formed by the system.

Claims

1. A system for projecting one or more synthetic optical images, which demonstrates improved resistance to optically degrading external effects, and which comprises:

(a) one or more arrangements of microstructured image icons; and

(b) one or more embedded arrangements of image icon focusing elements, wherein interstitial spaces between at least a portion of the image icon focusing elements are filled and the focusing elements are covered,

wherein the one or more arrangements of image icon focusing elements is disposed above the one or more arrangements of microstructured image icons such that at least a portion of the image icon focusing elements forms at least one synthetic image of at least a portion of the image icons,

wherein all interfaces responsible for focus are embedded within the system,

wherein the microstructured image icons are selected from the group consisting of (a) optionally coated and/or filled voids or recesses formed on or within a substrate, wherein the voids or recesses each measure from about 0.5 to about 8 microns in total depth, and (b) shaped posts formed on a surface of a substrate, wherein the shaped posts each measure from about 0.5 to about 8 microns in total height.

2. The system of claim 1, wherein the image icon focusing elements are refractive focusing elements having a focal length, the system 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.

3. The system of claim 2, 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.

4. The system of claim 1, which comprises:

(a) an array of image icons;

(b) an array of image icon focusing elements formed from a first material having a refractive index (n1); and

(c) a second material having a different refractive index (n2) that fills interstitial spaces between and covers the focusing elements, a distinct interface being formed between the first and second materials.

5. The system of claim 4, wherein the second material forms an outer boundary or layer of the array of image icons, thereby also embedding the array of image icons.

6. The system of claim 1, which comprises:

(a) an array of image icons; and

(b) an array of image icon focusing elements formed from a first material having a refractive index (n1) and a second material having a different refractive index (n2), the second material diffusing into the first material thereby forming a gradient interface with the first material.

7. The system of claim 4 or 6, wherein the first material has a refractive index ranging from about 1.5 to about 1.8.

8. The system of claim 7, wherein the first material is selected from the group of acrylated urethanes, epoxy acrylates and acrylic oligomers.

9. The system of claim 7, wherein the first material has a refractive index ranging from about 1.549 to about 1.56.

10. The system of claim 9, wherein the first material is a modified epoxy acrylate.

11. The system of claim 4 or 6, wherein the second material has a refractive index ranging from about 1.35 to about 1.49.

12. The system of claim 11, wherein the second material is selected from the group of urethane acrylates and acrylate monomers.

13. The system of claim 11, wherein the second material has a refractive index ranging from about 1.44 to about 1.45.

14. The system of claim 13, wherein the second material is isodecyl acrylate.

15. The system of claim 4 or 6, wherein the second material is a transparent or translucent adhesive.

16. A sheet material made from the system for projecting one or more synthetic optical images of claim 4 or 6.

17. A base platform made from the system for projecting one or more synthetic optical images of claim 4 or 6.

18. The base platform of claim 17, wherein the first material has a refractive index ranging from about 1.35 to about 1.49.

19. The base platform of claim 18, wherein the first material is selected from the group of urethane acrylics and acrylic monomers.

20. The base platform of claim 18, wherein the first material has a refractive index ranging from about 1.449 to about 1.46.

21. The base platform of claim 20, wherein the first material is tri(propylene glycol) diacrylate.

22. The base platform of claim 17, wherein the second material has a refractive index ranging from about 1.5 to about 1.8.

23. The base platform of claim 22, wherein the second material is selected from the group of epoxy acrylates, polyester oligomers, poly(aromatic carbonates), and poly(aliphatic carbonates).

24. The base platform of claim 22, wherein the second material has a refractive index ranging from about 1.584 to about 1.685.

25. The base platform of claim 24, wherein the second material is polycarbonate.

26. The base platform of claim 17, wherein the second material is a transparent or translucent adhesive.

27. A security device made from the system for projecting one or more synthetic optical images of claim 4 or 6.

28. The system of claim 4 or 6, wherein the first material is a high refractive index, colored or colorless material having a refractive index of more than 1.7.

29. The system of claim 4 or 6, wherein the second material is a high refractive index, colored or colorless material having a refractive index of more than 1.7.

30. The system of claim 4 or 6, wherein the focusing elements are selected from the group of converging lenses and diverging lenses.

31. The system of claim 1, wherein the one or more embedded arrangements of image icon focusing elements includes image icon focusing elements selected from the group of cylindrical lenses and non-cylindrical lenses.

32. The system of claim 31, wherein the one or more embedded arrangements of image icon focusing elements includes cylindrical lenses.

33. The system of claim 31, wherein the one or more embedded arrangements of image icon focusing elements includes non-cylindrical lenses.

34. The system of claim 31, wherein the lenses have spheric or aspheric surfaces.

35. The system of claim 31, wherein the lenses have widths or base diameters of less than or equal to about 1 millimeter.

36. The system of claim 35, wherein the lenses have widths or base diameters ranging from about 200 to about 500 microns.

37. The system of claim 35, wherein the lenses have widths or base diameters ranging from about 50 to about 199 microns.

38. The system of claim 35, wherein the lenses have widths or base diameters of less than about 50 microns.

39. The system of claim 38, wherein the lenses have widths or base diameters of less than about 45 microns.

40. The system of claim 39, wherein the lenses have widths or base diameters ranging from about 10 to about 40 microns.

41. The system of claim 1 or 31, wherein the system has a thickness of less than or equal to about 1 millimeter.

42. The system of claim 41, wherein the system has a thickness ranging from about 200 to about 500 microns.

43. The system of claim 41, wherein the system has a thickness ranging from about 50 to about 199 microns.

44. The system of claim 41, wherein the system has a thickness of less than about 50 microns.

45. A sheet material made from the system for projecting one or more synthetic optical images of claim 1.

46. The sheet material of claim 45, which is selected from the group of substrates for subsequent printing or personalization, sheet materials for security documents, and base platforms for identification cards and security documents.

47. The sheet material of claim 46, which is a sheet material for security documents.

48. The sheet material of claim 46, which is a base platform for identification cards and security documents.

49. The sheet material of claim 45 or 46, wherein the sheet material has a thickness of less than or equal to about 1 millimeter.

50. The sheet material of claim 49, wherein the sheet material has a thickness of from about 200 to about 500 microns.

51. The sheet material of claim 49, wherein the sheet material has a thickness of from about 50 to about 199 microns.

52. The sheet material of claim 49, wherein the sheet material has a thickness of less than about 50 microns.

53. A security device made from the system for projecting one or more synthetic optical images of claim 1.

54. The security device of claim 53, which is selected from the group of security strips, threads, patches, and overlays, for mounting on a surface of, or at least partially embedding within, a sheet material.

55. The security device of claim 53 or 54, wherein the security device has a thickness of less than about 50 microns.

56. The security device of claim 55, wherein the security device has a thickness of less than about 45 microns.

57. The security device of claim 56, wherein the security device has a thickness of from about 10 to about 40 microns.

58. A sheet material having opposing surfaces and comprising at least one security device of claim 54 mounted on a surface of, or at least partially embedded within, the sheet material.

59. A document made from the sheet material of claim 58.

60. The document of claim 59, which is selected from the group of banknotes, passports, identification cards, credit cards, and labels.

61. The document of claim 60, which comprises a banknote.

62. The system of claim 1, wherein optical separation between the arrangements of image icons and image icon focusing elements is achieved using an optical spacer.

63. The system of claim 62, wherein the optical spacer is formed using a material selected from the group consisting of polycarbonates, polyesters, polyethylenes, polyethylene napthalates, polyethylene terephthalates, polypropylenes, polyvinylidene chlorides, and combinations thereof.

64. The system of claim 1, wherein an outer boundary of the one or more embedded arrangements of image icon focusing elements is a planar surface.

65. The system of claim 1, wherein the one or more embedded arrangements of image icon focusing elements are refractive image icon focusing elements.

66. A sheet material made from a system for projecting one or more synthetic optical images, wherein the system comprises:

(a) an array of image icons;

(b) an array of refractive image icon focusing elements disposed above the array of image icons and formed from a first material having a refractive index (n1); and

(c) a second material having a different refractive index (n2) that fills interstitial spaces between and covers the focusing elements, a distinct interface being formed between the first and second materials,

wherein the microstructured image icons are selected from the group consisting of (a) optionally coated and/or filled voids or recesses formed on or within a substrate, wherein the voids or recesses each measure from about 0.5 to about 8 microns in total depth, and (b) shaped posts formed on a surface of a substrate, wherein the shaped posts each measure from about 0.5 to about 8 microns in total height.

67. A sheet material made from a system for projecting one or more synthetic optical images, wherein the system comprises:

(a) an array of image icons; and

(b) an array of refractive image icon focusing elements disposed above the array of image icons and formed from a first material having a refractive index (n1) and a second material having a different refractive index (n2), the second material filling interstitial spaces between at least a portion of the image icon focusing elements, covering the focusing elements, and diffusing into the first material thereby forming a gradient interface with the first material,

wherein the microstructured image icons are selected from the group consisting of (a) optionally coated and/or filled voids or recesses formed on or within a substrate, wherein the voids or recesses each measure from about 0.5 to about 8 microns in total depth, and (b) shaped posts formed on a surface of a substrate, wherein the shaped posts each measure from about 0.5 to about 8 microns in total height.

68. A sheet material having opposing surfaces and comprising at least one security device mounted on a surface of, or at least partially embedded within, the sheet material, wherein the security device is made from a system for projecting one or more synthetic optical images, the system comprising:

(a) one or more arrangements of image icons; and

(b) one or more embedded arrangements of refractive image icon focusing elements, wherein interstitial spaces between at least a portion of the image icon focusing elements are filled and the focusing elements are covered,

wherein the one or more arrangements of refractive image icon focusing elements is disposed above the one or more arrangements of image icons such that at least a portion of the image icon focusing elements forms at least one synthetic image of at least a portion of the image icons,

wherein all interfaces responsible for focus are embedded within the system,

wherein the microstructured image icons are selected from the group consisting of (a) optionally coated and/or filled voids or recesses formed on or within a substrate, wherein the voids or recesses each measure from about 0.5 to about 8 microns in total depth, and (b) shaped posts formed on a surface of a substrate, wherein the shaped posts each measure from about 0.5 to about 8 microns in total height.

69. A document made from the sheet material of claim 68.

70. The document of claim 69, which is selected from the group of banknotes, passports, identification cards, credit cards, and labels.

71. The document of claim 70, which comprises a banknote.

72. A system for projecting one or more synthetic optical images, which demonstrates improved resistance to optically degrading external effects, and which comprises:

(a) one or more arrangements of image icons; and

(b) one or more embedded arrangements of refractive image icon focusing elements, wherein interstitial spaces between at least a portion of the image icon focusing elements are filled and the focusing elements are covered,

wherein the one or more arrangements of refractive image icon focusing elements is disposed above the one or more arrangements of image icons such that at least a portion of the image icon focusing elements forms at least one synthetic image of at least a portion of the image icons,

wherein all interfaces responsible for focus are embedded within the system, and

wherein optical separation between the arrangements of image icons and refractive image icon focusing elements is achieved using an optical spacer,

wherein the microstructured image icons are selected from the group consisting of (a) optionally coated and/or filled voids or recesses formed on or within a substrate, wherein the voids or recesses each measure from about 0.5 to about 8 microns in total depth, and (b) shaped posts formed on a surface of a substrate, wherein the shaped posts each measure from about 0.5 to about 8 microns in total height.

73. The system of claim 72, wherein the optical spacer is formed using a material selected from the group consisting of polycarbonates, polyesters, polyethylenes, polyethylene napthalates, polyethylene terephthalates, polypropylenes, polyvinylidene chlorides, and combinations thereof.

74. A system for projecting one or more synthetic optical images, which demonstrates improved resistance to optically degrading external effects, and which comprises:

(a) one or more arrangements of microstructured image icons; and

(b) one or more embedded arrangements of image icon focusing elements, wherein interstitial spaces between at least a portion of the image icon focusing elements are filled and the focusing elements are covered,

wherein the one or more arrangements of image icon focusing elements is disposed above the one or more arrangements of microstructured image icons such that at least a portion of the image icon focusing elements forms at least one synthetic image of at least a portion of the image icons,

wherein all interfaces responsible for focus are embedded within the system,

wherein the microstructured image icons are optionally coated and/or filled voids or recesses formed on or within a substrate, wherein the voids or recesses each measure from about 0.5 to about 8 microns in total depth.

75. The system of claim 74, wherein the image icon focusing elements are refractive focusing elements.

76. The system of claim 74 or 75, wherein the voids or recesses are filled with a submicron particle pigmented coloring material.

77. A system for projecting one or more synthetic optical images, which demonstrates improved resistance to optically degrading external effects, and which comprises:

(a) one or more arrangements of microstructured image icons; and

(b) one or more embedded arrangements of image icon focusing elements, wherein interstitial spaces between at least a portion of the image icon focusing elements are filled and the focusing elements are covered,

wherein the one or more arrangements of image icon focusing elements is disposed above the one or more arrangements of microstructured image icons such that at least a portion of the image icon focusing elements forms at least one synthetic image of at least a portion of the image icons,

wherein all interfaces responsible for focus are embedded within the system,

wherein the microstructured image icons are formed from shaped posts formed on a surface of a substrate, wherein the shaped posts each measure from about 0.5 to about 8 microns in total height.