Methods and ink compositions for invisibly printed security images having multiple authentication features

• US 20040233465A1
• Filed: 04/05/2004
• Published: 11/25/2004
• Est. Priority Date: 04/04/2003
• Status: Active Grant

• Current Assignee: Angstrom Technologies, Inc.
• Original Assignee: Angstrom Technologies, Inc.
• Inventors: Coyle, William J., Smith, John C.
• Granted Patent: US 7,821,675 B2
• Time in Patent Office: Days
• US Class Current: 358/1.9
• CPC Class Codes: B41M 3/008 Sequential or multiple printing, e.g. on previously printed background; Mirror printing; Recto-verso printing; using a combination of different printing techniques; Printing of patterns visible in reflection and by transparency; by superposing printed artifacts
• CPC Class Codes: B41M 3/06 Veined printings; Fluorescent printings; Stereoscopic images; Imitated patterns, e.g. tissues, textiles
• CPC Class Codes: B41M 3/144 using fluorescent, luminescent or iridescent effects
• CPC Class Codes: B82Y 10/00 Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: C09D 11/32 characterised by colouring agents
• CPC Class Codes: C09D 11/50 Sympathetic, colour changing or similar inks

Abstract

An article is marked with image indicia for authentication, information, or decoration by providing a plurality of inks having a plurality of fluorescence colors when exposed to excitation energy, separating colors of the image indicia into a plurality of image levels in accordance with the fluorescence colors of the inks, and printing each image level in mutual registration on the article using the corresponding ink. The image printed with each ink may be substantially invisible under illumination within the visible spectrum. The invisibly printed images have multiple authentication features, including the use of covert UV-fluorescent materials, IR-fluorophores, microparticles, and other chemical taggants. Ink compositions, methods for making the inks, and methods and apparatus for using the inks are also disclosed.

Claims

1. A method of marking an article with image indicia for authentication, information, or decoration, the method comprising the steps of:

a) providing a plurality of inks that, when printed as image indicia on an article, fluoresce with a color when exposed to excitation energy and are substantially invisible under illumination within the visible spectrum;

b) separating colors of the image indicia into a plurality of image levels; and

c) printing each image level of said plurality of image levels in mutual registration on the article using said plurality of inks.

2. The method of claim 1, wherein said plurality of inks comprises inkjet inks and the step c) of printing is performed using an inkjet print head.

3. The method of claim 2, wherein the step c) of printing is performed using an inkjet printer, the method further comprising the steps of:

d) converting indicia to be printed to a color negative form; and

e) providing a set of red, green and blue additive-color inks within said plurality of inks that are complementary, respectively, to cyan, magenta and yellow subtractive-color inks.

4. The method of claim 2, wherein the step c) of printing is performed using an inkjet printer intended for use with subtractive-color ink cartridges, the method further including the step of using cartridges in the inkjet printer having red, green and blue additive-color inks that are complementary, respectively, to cyan, magenta and yellow subtractive-color inks.

5. The method of claim 2, wherein the step c) of printing is performed using an inkjet printer intended for use with reservoirs containing subtractive-color ink, the method further including the step of using red, green and blue additive-color inks in the reservoirs that are complementary, respectively, to cyan, magenta and yellow subtractive-color inks.

6. The method of claim 3, further comprising the step of:

f) disabling any black-ink print head of an inkjet printer used in step c) of printing.

7. The method of claim 3, further including the step of selecting a suitably weighted combination of colors selected from said set of red, green and blue additive colors to create white additive color.

8. The method of claim 2, wherein the step c) of printing is performed using an inkjet printer, the method further comprising the steps of:

d) converting indicia to be printed to a color negative form; and

e) providing a set of additive-color inks including at least two colors from the group consisting of red, green and blue inks, wherein said colors within said set are complementary to ones from the group consisting of cyan, magenta and yellow subtractive-color inks.

9. The method of claim 3, wherein said set of additive color inks includes red, blue, and green additive primary colors compatible in accordance with an RGB standard.

10. The method of claim 9, wherein said RGB standard is selected from the list consisting of:

a) International Radio Consultative Committee (CCIR) Standard 601;

b) International Telecommunications Union, Radiocommunications Sector (ITU-R) “

Studio encoding parameters of digital television for standard 4;

3 and wide screen 16;

9 aspect ratios”

Standard BT.601;

c) Electronic Industries Association (EIA) Standard RS-170A;

d) Video Electronics Standards Association (VESA) Standard 1.2; and

e) their successor standards and versions.

11. The method of claim 3, wherein said set of additive-color inks comprises at least two components from the group consisting of:

a) a red component having a dominant emissive wavelength between about 590 and about 680 nanometers;

b) a green component having a dominant emissive wavelength between about 500 and about 550 nanometers; and

c) a blue component having a dominant emissive wavelength between about 420 and about 480 nanometers.

12. The method of claim 3, wherein the set of additive color inks comprises at least two components from the group consisting of:

a) a red component having CIE 1931 chromaticity coordinates of about (+/−

0.05);

(0.48, 0.22) (0.48, 0.43), and (0.67, 0.26);

b) a green component having CIE 1931 chromaticity coordinates of about (+/−

0.05);

(0.14, 0.42) (0.12, 0.72), and (0.43, 0.46); and

c) a blue component having CIE 1931 chromaticity coordinates of about (+/−

0.05);

(0.16, 0.10) (0.15, 0.38), and (0.30, 0.15).

13. The method of claim 1, wherein the step b) of separating colors of the image indicia into a plurality of image levels is performed by a suitably programmed computer.

14. The method of claim 1, wherein the step b) of separating colors of the image indicia into a plurality of image levels is performed by a printer used to perform the printing step c).

15. The method of claim 1, wherein the image indicia include human skin tones.

16. The method of claim 1, wherein the color gamut of the image indicia includes hues having RGB values of about (190, 147, 127), (205, 163, 144), (92, 67, 52), and (129, 96, 82), and by hue/saturation/value (HSV) indices of about (18.7, 0.298, 0.804) and (17.9, 0.364, 0.506).

17. The method of claim 1, wherein the image indicia comprise at least one image of a human subject.

18. The method of claim 1, wherein the image indicia fulfill the official format requirements of a passport photograph.

19. The method of claim 1, wherein one or more of the plurality of inks includes a plurality of fluorescence colors includes microparticles of a size not resolvable by the unaided human eye.

20. The method of claim 19, wherein said microparticles are coded by a specific pattern of color bands.

21. The method of claim 19, wherein said microparticles are coded by chemical signature tagging.

22. The method of claim 19, wherein said microparticles have diameters of about one micrometer or less.

23. The method of claim 1, wherein the image indicia printed on the article is for authentication, the method further including the steps of:

illuminating the article with excitation energy to display resultant color image indicia by emission of fluorescent light having a plurality of fluorescence colors; and

comparing the resultant color image indicia with colored reference indicia.

24. The method of claim 23, further comprising the step of:

passing the emitted fluorescent light through an optical filter before comparing the resultant color image indicia with colored reference indicia.

25. The method of claim 24, wherein the optical filter selectively blocks light according to criteria selected from the list consisting of:

specific light wavelength(s), light wavelengths above a first predetermined limit, light wavelengths below a second predetermined limit, a bandwidth range of light wavelengths, light having a range of colors, and fluorescent light emitted by one or more known fluorescent chromophores.

26. The method of claim 23, wherein the step of comparing the resultant color image indicia with colored reference indicia is performed visually.

27. The method of claim 23, wherein the step of comparing the resultant color image indicia with colored reference indicia is performed by a suitably programmed computer.

28. The method of claim 1, wherein the image indicia marked on the articles include multiple authentication features.

29. The method of claim 28, wherein said multiple authentication features comprise multiple chromophores having distinguishable wavelengths, linewidths, intensities, and decay times of fluorescent light emission.

30. The method of claim 29, wherein at least one chromophore of said multiple chromophores does not contribute to visual appearance of the image but selectively masks the fluorescent light from other chromophores.

31. The method of claim 1, wherein the image indicia marked on the articles include primary, secondary and tertiary authentication features.

32. The method of claim 31, further including the steps of:

a) defining as tertiary authentication features a relationship between (i) at least two of said primary authentication features, (ii) at least two of said secondary authentication features or (iii) at least one of said primary authentication features and at least one of said secondary authentication features; and

b) exposing the article to said excitation energy and comparing said color with said tertiary authentication feature.

33. A method of marking an article with image indicia for authentication, information, or decoration, the method comprising the steps of:

a) providing black ink;

b) providing a plurality of color inks that, when printed as indicia on an article, fluoresce with a color when exposed to excitation energy and are substantially invisible under illumination within the visible spectrum;

c) separating colors of the image indicia into a black image level and a plurality of color image levels; and

d) printing said black image level and said plurality of color image levels in mutual registration on the article using said black ink and said plurality of color inks.

34. A method of marking an article with image indicia for authentication, information, or decoration, the method comprising the steps of:

a) providing a plurality of inkjet inks that, when printed as indicia on an article, fluoresce with a color when exposed to excitation energy and are substantially invisible under illumination within the visible spectrum;

b) converting color indicia to be printed to a color negative form;

c) separating colors of the image indicia into a plurality of image levels;

d) providing an inkjet printer intended for use with subtractive-color ink; and

e) printing each image level of said plurality of image levels in mutual registration on the article using said plurality of inkjet inks and said inkjet printer.

35. The method of claim 34, wherein each of the plurality of inkjet inks comprises, by weight percent:

distilled or deionized water;

0 to 95.0%;

a biocide;

0 to 3.0%;

N-methyl-2-pyrrolidinone [872-50-4];

0 to 20.0%;

non-ionic surfactant;

0 to 1.0%;

butyl carbitol [112-34-5];

0 to 30.0%;

glycerol [56-81-5];

0 to 40.0%;

diethylene glycol [11-46-6];

0 to 40.0%;

2-pyrrolidinone;

0 to 20.0%;

polyethylene glycols;

0 to 40.0%;

ethanol;

0 to 40.0%;

propanol;

0 to 40.0%;

other anionic, cationic, and non-ionic surfactants;

0 to 15.0%;

buffer salts;

0 to 20.0%;

fluorescent chromophore;

0 to 20.0%; and

semiconductor nanocrystal, microparticle or other chemical taggant;

0 to 20.0%.

36. The method of claim 35, wherein the fluorescent chromophore fluoresces under excitation by ultraviolet (UV) light.

37. The method of claim 35, wherein the fluorescent chromophore fluoresces under excitation by infrared (IR) light.

38. The method of claim 35, wherein the fluorescent chromophores of the plurality of inkjet inks fluoresce in additive colors that are complementary to the colors of conventional cyan, magenta, and yellow subtractive-color inks.

39. The method of claim 35, wherein the fluorescent chromophores of the plurality of inkjet inks fluoresce in red, green, and blue portions of the visible spectrum.

40. The method of claim 39, wherein the plurality of inkjet inks comprises:

a) a red fluorescence color component having a dominant emissive wavelength between about 590 and about 680 nanometers;

b) a green fluorescence color component having a dominant emissive wavelength between about 500 and about 550 nanometers; and

c) a blue fluorescence color component having a dominant emissive wavelength between about 420 and about 480 nanometers.

41. The method of claim 34, wherein the plurality of inkjet inks comprises:

a) a red fluorescence color component having CIE 1931 chromaticity coordinates of about (+/−

0.05);

(0.48, 0.22) (0.48, 0.43), and (0.67, 0.26);

b) a green fluorescence color component having CIE 1931 chromaticity coordinates of about (+/−

0.05);

(0.14, 0.42) (0.12, 0.72), and (0.43, 0.46); and

c) a blue fluorescence color component having CIE 1931 chromaticity coordinates of about (+/−

0.05);

(0.16, 0.10) (0.15, 0.38), and (0.30, 0.15).

44. A method of authenticating articles, comprising the steps of:

a) marking authentic articles with invisible full-color image indicia by the method of claim 34;

b) using suitable illumination, illuminating articles to be authenticated; and

c) comparing any resultant fluorescent emissive indicia with the predetermined full-color image indicia marked on authentic articles.

42. A set of inkjet cartridges for use in an inkjet printer for printing fluorescent image indicia, the set of inkjet cartridges comprising:

a) a first ink cartridge carrying a first ink invisible under ordinary white-light illumination, said first ink being fluorescent with a color complementary to cyan;

b) a second ink cartridge carrying a second ink invisible under ordinary white-light illumination, said second ink being fluorescent with a color complementary to magenta; and

c) a third ink cartridge carrying a third ink invisible under ordinary white-light illumination, said third ink being fluorescent with a color complementary to yellow.

43. The set of inkjet cartridges of claim 42, further comprising:

d) a fourth ink cartridge carrying black ink.

45. A method of authenticating articles, comprising the steps of:

a) marking authentic articles with invisible predetermined full-color image indicia by performing the substeps of;

i) providing a plurality of inkjet inks that, when printed as indicia on the article, fluoresce with a color when exposed to excitation energy and are substantially invisible under illumination within the visible spectrum;

ii) converting color indicia to be printed to a color negative form;

iii) separating colors of the image indicia into a plurality of image levels; and

iv) providing an inkjet printer intended for use with subtractive-color ink; and

v) printing each image level of said plurality of image levels in mutual registration on the article using said plurality of inkjet inks and said inkjet printer;

b) using suitable excitation energy, exposing articles to be authenticated to said excitation energy; and

c) comparing any resultant fluorescent emissive indicia with the predetermined full-color image indicia marked on authentic articles.

46. An ink composition, comprising by weight percent:

distilled or deionized water;

0 to 95.0%;

a biocide;

0 to 3.0%;

N-methyl-2-pyrrolidinone [872-50-4];

0 to 20.0%;

non-ionic surfactant;

0 to 1.0%;

butyl carbitol [112-34-5];

0 to 30.0%;

glycerol [56-81-5];

0 to 40.0%;

diethylene glycol [11-46-6];

0 to 40.0%;

2-pyrrolidinone;

0 to 20.0%;

polyethylene glycols;

0 to 40.0%;

ethanol;

0 to 40.0%;

propanol;

0 to 40.0%;

other anionic, cationic, and non-ionic surfactants;

0 to 15.0%;

buffer salts;

0 to 20.0%;

fluorescent chromophore;

0 to 20.0%, with semiconductor nanocrystal, microparticle or other component;

0 to 15.0%, said fluorescent chromophore having an emission color that corresponds to a portion of the visible spectrum complementary to one of the colors of conventional cyan, magenta, and yellow subtractive-color inks.

47. The ink composition of claim 46, wherein said fluorescent chromophore fluoresces in one of the red, green, and blue portions of the visible spectrum respectively.

48. The ink composition of claim 46, wherein the fluorescent chromophore has a red dominant emissive wavelength between about 590 and about 680 nanometers.

49. The ink composition of claim 46, wherein the fluorescent chromophore has a green dominant emissive wavelength between about 500 and about 550 nanometers.

50. The ink composition of claim 46, wherein the fluorescent chromophore has a blue dominant emissive wavelength between about 420 and about 480 nanometers.

51. The ink composition of claim 46, wherein the fluorescent chromophore has a red fluorescence color having CIE 1931 chromaticity coordinates of about (+/−

0.05);

(0.48, 0.22) (0.48, 0.43), and (0.67, 0.26).

52. The ink composition of claim 46, wherein the fluorescent chromophore has a green fluorescence color having CIE 1931 chromaticity coordinates of about (+/−

0.05);

(0.14, 0.42) (0.12, 0.72), and (0.43, 0.46).

53. The ink composition of claim 46, wherein fluorescent chromophore has a blue fluorescence color having CIE 1931 chromaticity coordinates of about (+/−

0.05);

(0.16, 0.10) (0.15, 0.38), and (0.30, 0.15).

54. An ink composition for an inkjet printer, the composition comprising by weight:

distilled or deionized water;

0-95%;

a biocide;

0 to 3.0%;

a non-ionic surfactant;

0 to 1.0%;

organic humectants;

0 to 40%;

ethanol;

0 to 40%;

propanol;

0 to 40%;

buffer salts;

0 to 20.0%;

at least one of a fluorophore pigment, a fluorophore dye, and quantum dots;

0 to 20%.

55. An ink composition according to claim 54, wherein said quantum dot component has a fluorescent emission under illumination outside the visible spectrum.

56. Image indicia comprising:

a) a plurality of image levels, at least two of which are created with an inkjet ink having a composition by weight of;

distilled or deionized water;

0-95%;

a biocide;

0 to 3.0%;

a non-ionic surfactant;

0 to 1.0%;

organic humectants;

0 to 40%;

ethanol;

0 to 40%;

propanol;

0 to 40%;

buffer salts;

0 to 20.0%;

fluorophore pigment or dye;

0 to 20%; and

b) a plurality of quantum dots.

57. Image indicia according to claim 56, further including secondary and tertiary authentication features.

58. Image indicia comprising:

a) a plurality of image levels, at least two of which are created with an inkjet ink having a composition by weight of;

distilled or deionized water;

0-95%;

a biocide;

0 to 3.0%;

a non-ionic surfactant;

0 to 1.0%;

organic humectants;

0 to 40%;

ethanol;

0 to 40%;

propanol;

0 to 40%;

buffer salts;

0 to 20.0%;

fluorophore pigment or dye;

0 to 20%; and

b) a plurality of microparticles.

59. Image indicia comprising:

a) a plurality of image levels, at least two of which are created with an inkjet ink having a composition by weight of;

distilled or deionized water;

0-95%;

a biocide;

0 to 3.0%;

a non-ionic surfactant;

0 to 1.0%;

organic humectants;

0 to 40%;

ethanol;

0 to 40%;

propanol;

0 to 40%;

buffer salts;

0 to 20.0%;

fluorophore pigment or dye;

0 to 20%; and

b) a plurality of immunochemical taggants.

60. An additive color inkjet ink that fluoresces with a color under illumination outside of the visible spectrum, said ink having a red component with CIE 1931 chromaticity coordinates of about (+/−

0.05);

(0.48, 0.22) (0.48, 0.43), and (0.67, 0.26).

61. An additive color inkjet ink that fluoresces with a color under illumination outside of the visible spectrum, said ink having a green component with CIE 1931 chromaticity coordinates of about (+/−

0.05);

(0.14, 0.42) (0.12, 0.72), and (0.43, 0.46).

62. An additive color inkjet ink that fluoresces with a color under illumination outside of the visible spectrum, said ink having a blue component with CIE 1931 chromaticity coordinates of about (+/−

0.05);

(0.16, 0.10) (0.15, 0.38), and (0.30, 0.15).

63. A set of additive color inkjet inks that fluoresce with colors under illumination outside of the visible spectrum, said inks together color gamut with CIE 1931 chromaticity coordinates of about (+/−

0.05);

(0.16, 0.10) (0.12, 0.72) (0.67, 0.27).

64. A set of additive color inkjet inks that fluoresce with colors under illumination outside of the visible spectrum, said inks together color gamut with CIE 1931 chromaticity coordinates of about (+/−

0.05);

(0.1, 0.7) (0.16, 0.17) (0.23, 0.008) (0.62, 0.27) (0.46, 0.5).

65. Image indicia comprising:

a. a first image layer formed with a first additive-color inkjet printer ink having fluorescent emission upon excitation, said first image layer having a first primary authentication feature and a first secondary authentication feature;

b. a second image layer formed with a second additive-color inkjet printer ink having fluorescent emission upon excitation, said second image layer having a second primary authentication feature and a second secondary authentication feature;

wherein at least one of (i) said first and second primary authentication features and (ii) said first and second secondary authentication features are different.

66. Image indicia according to claim 65, wherein at least one of said first and second secondary authentication features includes a plurality of quantum dots.

67. Image indicia according to claim 65, wherein said first secondary authentication feature includes a plurality of quantum dots having a first emission attribute when subjected to illumination outside the visible spectrum and said second secondary authentication feature includes plurality of quantum dots having a second emission attribute when subjected to illumination outside the visible spectrum, wherein said first emission attribute differs from said second emission attribute.

68. Image indicia according to claim 65, wherein at least one of said first and second secondary authentication features includes a plurality of microparticles.

69. Image indicia according to claim 68, wherein said plurality of microparticles is coded by specific color bands or with chemical taggants.

70. Image indicia according to claim 65, wherein said first secondary authentication feature includes a plurality of microparticles having a first specific pattern of color bands or chemical taggant and said second secondary authentication feature includes plurality of microparticles having a second specific pattern of color bands or chemical taggant, wherein said first pattern of color bands or chemical taggant is different than said second pattern of color bands or chemical taggant.

71. Image indicia according to claim 65, wherein at least one of said first and second secondary authentication features includes scent.

72. Image indicia according to claim 65, wherein said first secondary authentication feature includes a first scent and said second secondary authentication feature includes a second scent that is different than said first scent.

73. Image indicia according to claim 65, wherein at least one of said first and second secondary authentication features includes an immunochemical component.

74. Image indicia according to claim 65, wherein said first secondary authentication feature includes a first immunochemical component and said secondary authentication feature includes a second immunochemical component that is different than said first immunochemical component.

75. Image indicia according to claim 65, further including at least one tertiary authentication feature.

76. Image indicia according to claim 75, wherein said at least one tertiary authentication feature is defined by a relationship between selected ones of (i) said first and second primary authentication features and (ii) said first and second secondary authentication features.

77. Image indicia according to claim 65, wherein said fluorescent emission of at least one of said first and second image layers is in the UV range.

78. Image indicia according to claim 65, wherein said fluorescent emission of at least one of said first and second image layers is in the NIR range.

79. Image indicia according to claim 65, wherein said fluorescent emission of at least one of said first and second image layers is in the IR range.

80. Image indicia according to claim 65, wherein said fluorescent emission of at least one of said first and second image layers is in the visible spectrum range.

81. Image indicia according to claim 65, wherein at least one of said first and second secondary authentication features includes IR-absorbing materials.

82. A full-color, high-resolution image created from a plurality of image layers, said plurality of image layers comprising:

a. a first image layer created with an inkjet ink that fluoresces with a red color under illumination outside the visible spectrum;

b. a second image layer created with an inkjet ink that fluoresces with a green color under illumination outside the visible spectrum; and

c. a third image layer created with an inkjet ink that fluoresces with a blue color under illumination outside the visible spectrum.

83. A full-color, high-resolution image according to claim 82, wherein said red color is complementary to cyan subtractive-color ink, said green color is complementary to magenta subtractive-color ink and said blue color is complementary to yellow subtractive-color ink.

84. An article with authentication features, the features comprising:

a. alpha-numeric information;

b. image indicia having a plurality of image levels, wherein one of said image levels has first authentication features and another of said image levels has second authentication features that differ from said first authentication features, wherein said first and second authentication features do not include fluorescent color emission.

85. An article according to claim 84, wherein one of said first and second authentication features are selected from the group comprising:

scent, IR-absorbing materials, microparticles, and materials that emit electromagnetic radiation other than in the NIR, IR, UV and visible spectrum ranges.

86. A barcode comprising:

a. a substrate; and

b. a plurality of bands printed on said substrate with an additive color inkjet ink that has a fluorescent emission when exposed to excitation energy;

c. wherein portions of said substrate between said plurality of bands have substantially no fluorescent emission when exposed to said excitation energy.

87. A barcode according to claim 86, wherein said portions of said substrate are covered with a fluorescent quencher.

88. A barcode according to claim 86, wherein said portions of said substrate do not include optical brighteners.

89. A barcode according to claim 86, wherein said ink has a white fluorescent emission when exposed to said excitation energy.

90. An inkjet ink having a fluorophore that emits in the red spectrum, the fluorophore comprising the structure:

91. An inkjet ink having a fluorophore that emits in the red spectrum, the fluorophore comprising the structure:

92. An inkjet ink having a fluorophore that emits in the red spectrum, the fluorophore comprising the structure: