Encoded security document

• US 4,455,039 A
• Filed: 06/24/1982
• Issued: 06/19/1984
• Est. Priority Date: 10/16/1979
• Status: Expired due to Fees

• Current Assignee: Coulter Systems Corporation
• Original Assignee: Coulter Systems Corporation
• Inventors: Weber, Harold J., D'Amato, Salvatore F., Kuehnle, Manfred R., Weitzen, Edward H., Fleming, Robert M., Kruse, Jurgen, Ekman, C. Frederick
• Primary Examiner(s): Bell, Paul A.
• Application Number:
  US06/391,690
• Time in Patent Office: 726 Days
• Field of Search: 283/82, 283/83, 283/84, 283/901, 283/58, 283/904
• US Class Current: 283/83
• CPC Class Codes: B41M 3/14 Security printing securities B42D25/29
• CPC Class Codes: G06K 19/10 at least one kind of marking being used for authentication, e.g. of credit or identity cards verification of coded identity or credit cards in mechanisms actuated by them G07F7/12
• CPC Class Codes: G07D 7/02 Testing electrical properties of the materials thereof G07D7/01 takes precedence
• CPC Class Codes: G07F 7/086 by passive credit-cards adapted therefor, e.g. constructive particularities to avoid counterfeiting, e.g. by inclusion of a physical or chemical security-layer for security documents G07D7/00; for the reading of record-carriers in general G06K7/00; for the design of coded credit-cards G06K19/10
• CPC Class Codes: Y10S 283/901 Concealed data
• CPC Class Codes: Y10S 283/904 Credit card

Abstract

Documents are encoded with at least one thin, transparent coating, normally invisible, but having a readily detectable physical characteristic such as, electrical conductivity, electrical impedance, electrical capacitance, electroluminescence. Each document consists of a substrate on which is applied (1) at least one of the thin coatings, and (2) conventional printing, preferably intaglio. The thin coating may be applied before or after the printing. The coating includes particles driven into the surface to a substantial depth. The uncoated substrate is free of the detectable physical characteristic. The coating is confined to a limited area of the substrate surface and itself constitutes a code or is laid down in a pattern for identification. A second coating can be applied so that all areas of the surface have the same appearance to mask visual detection of the first coating. The first coating can be of such a nature as to defeat electrostatic copying, particular, color copying, by effecting a discernible difference between the original and the copy. Each coded coating is detectable by a machine which is capable of quickly distinguishing a genuine document from a counterfeit document.

Claims

1. A security document of value having a mark detectable by apparatus responsive to electrical capacitance as a particular physical characteristic of the mark and thereby distinguishable from a counterfeit document lacking such a mark, comprising:

a substrate of a first material free from said physical characteristic,

a mark formed as a coating of a second material having said physical characteristic, said coating consisting of a particulate generally invisible very thin surface layer sputter-deposited on a portion only of one surface of said substrate and a sub-surface region below said very thin layer formed of discrete particles of said second material embedded within said first material arrayed in nonelectrically conductive relationship one relative to the others as a continuation of said thin surface layer, there being a greater number of particles of said second material in the sub-surface region than in the surface layer, the physical characteristic of said particulate material being electrical capacitance, said mark being nondetectable except by said apparatus and

visually observable matter overprinted on said document.

2. The security document as claimed in claim 1 in which said overprinted matter extends at least in part over the coating.

3. The security document as claimed in claim 1 in which said document is an elongated sheet and said coating is a pattern of at least one band extending across the short dimension of the sheet.

4. The security document as claimed in claim 1 in which said coating having the physical characteristic is confined to a limited area of the substrate surface.

5. The security document as claimed in claim 1 in which said coating extends over at least one area of said document.

6. The security document as claimed in claim 1 in which said coating is less than 500 Angstrom units in thickness.

7. The security document as claimed in claim 1 in which said coating comprises at least a pair of spaced bands extending across the narrow dimension of said document.

8. The security document as claimed in claim 1 in which said coating is located in different limited areas of the document, the location depending upon the nature of said document and each location being different for different documents.

9. The security document as claimed in claim 1 in which said coating is sputtered onto said substrate.

10. The security document as claimed in claim 1 in which said overprinting is in registry with said coating.

11. The security document as claimed in claim 1 in which said visually observable matter overprinted on said document extends over said coating onto the substrate substantially surrounding said mark.

12. The security document as claimed in claim 1 in which there is a second coating over said substrate, said physical characteristic being absent from said second coating.

13. The security document as claimed in claim 12 in which there is a non-conductive coating over the substrate and the first coating.

14. The security document as claimed in claim 1 in which said coating covers completely one surface of the substrate so that all parts of the surface not covered by printed matter have a uniform finish.

15. The security document as claimed in claim 1 in which said coating is formed of indium tin oxide particles.

16. A security document of value having a mark detectable by apparatus responsive to a particular physical characteristic of the mark and thereby distinguishable from a counterfeit document lacking such a mark, comprising:

a substrate of a first material free from said physical characteristic,

a mark-defining coating of a second material having said physical characteristic, said coating consisting of a particulate generally invisible very thin layer sputter-deposited on a portion only of one surface of the substrate and a sub-surface region below said thin layer formed of discrete particles of said second material embedded within said first material under said coating as a continuation of said thin surface layer,

the physical characteristic of said particulate material being electrical capacitance, visually nondetectable but its presence capable of being sensed only by said detecting apparatus and

a layer of visually observable material on said document between said substrate and the coating of the second material.

17. A security document of value having a mark detectable by apparatus responsive to a particular physical characteristic of the mark and thereby distinguishable from a counterfeit document lacking such a mark, comprising:

a substrate of a first material free from said physical characteristic,

a mark-defining coating of a second material having said physical characteristic, said coating consisting of a particulate generally invisible very thin layer sputter-deposited on a portion only of one surface of the substrate and a sub-surface region below said thin layer formed of discrete particles of said second material embedded within said first material under said coating as a continuation of said thin surface layer, the physical characteristic of said particulate material being electrical capacitance, visually nondetectable but its presence capable of being sensed only by said detecting apparatus,

visually observable matter printed on said document, and

said coating is formed as a plurality of transparent thin layers each of different particulate materials other than said first material on one surface of the substrate and each layer of said particulate material having a substantial number of the particles embedded in a subsurface region of the substrate, one only of said layers comprising said coating and covering only a portion of said one surface and being detectable only by apparatus insensitive to the presence of the other of said layers.

18. The security document as claimed in claim 17 in which at least part of said visually observable matter is printed over at least one of said layers.

19. The security document as claimed in claim 17 in which at least one layer is applied over at least a part of the visually observable printed matter.

20. The security document as claimed in claim 17 and an outer layer formed of wear resistant material.

21. The security document as claimed in claim 17 in which all of said one surface is covered by the outer one of said layers.

22. The security document as claimed in claim 17 in which only the portion of said one surface not covered by said one layer is covered by a second of the layers.

23. The security document as claimed in claim 17 in which said coating is located on more than one portion of said one surface of the substrate, the characteristic of said coating at one portion being different than the characteristic of said coating at another portion of the said one surface.

24. A security document of value having a mark detectable by apparatus responsive to a particular physical characteristic of the mark and thereby distinguishable from a counterfeit document lacking such a mark, comprising:

a substrate of a first material free from said physical characteristic,

a mark defining coating of a second material having said physical characteristic,

said coating consisting of a particulate generally invisible very thin layer sputter-deposited on a portion only of one surface of the substrate and a sub-surface region below said thin layer formed of discrete particles of said second material embedded within said first material under said coating as a continuation of said thin surface layer,

the physical characteristic of said particulate material being electrical capacitance, visually nondetectable but is presence capable of being sensed only by said detecting apparatus,

visually observable matter printed on said document and

a transparent second coating of machine detectable material on a portion of the opposite surface of said substrate from said first mentioned coating and partially embedded in a subsurface region of said opposite surface.

25. The security document as claimed in claim 24 in which the machine detectable material of said transparent second coating is independently detectable relative to the machine detectable material of said first mentioned coating.

26. A sheet material suitable for printing a security document of a value and having a mark detectable by apparatus responsive to electrical capacitance as a particular physical characteristic of the mark, comprising:

a substrate of a first material free from said physical characteristic,

said mark being formed of a coating of a second material having said physical characteristic, said coating comprising particulate generally invisible thin surface layer deposited on a portion only of one surface of said substrate and a sub-surface region of particles of said second material embedded below said thin surface layer as a continuation of said thin surface layer, said subsurface region being substantially thicker than said thin surface layer,

said coating being invisible and nondetectable physically except by said apparatus, the particles of at least the said subsurface layer consisting of particles arrayed in nonelectrically conductive relationship, one relative the other, and embedded therein.

27. A sheet material as claimed in claim 26 in which said first material is an elongated web and said coating is least one band extending lengthwise of the web.

28. A security document of value having a mark detectable by apparatus responsive to a particular physical characteristic of the mark and thereby distinguishable from a counterfeit document lacking such a mark, comprising:

a substrate of a first material free from said physical characteristic,

a mark-defining coating of a second material having said physical characteristic, said coating consisting of a particulate generally invisible very thin layer sputter-deposited on a portion only of one surface of the substrate and a sub-surface region below said thin layer formed of discrete particles of said second material embedded within said first material under said coating as a continuation of said thin surface layer, the depth of the sub-surface region being greater than the thickness of the thin layer, the physical characteristic of said particulate material being electrical capacitance, visually nondetectable but its presence capable of being sensed only by said detecting apparatus and

visually observable matter printed on said document.

29. The security document as claimed in claim 28 in which said coating is applied over at least part of the visually observable matter and over a part of the substrate not covered by the observable matter.