Security device

• US 6,903,850 B2
• Filed: 06/27/2001
• Issued: 06/07/2005
• Est. Priority Date: 06/28/2000
• Status: Expired due to Term

• Current Assignee: De La Rue International Limited (De La Rue PLC)
• Original Assignee: De La Rue International Limited (De La Rue PLC)
• Inventors: Holmes, Brian William, Kay, Ralph
• Primary Examiner(s): Boutsikaris, Leonidas
• Application Number:
  US10/297,391
• Publication Number:
  US 20040100707A1
• Time in Patent Office: 1,441 Days
• Field of Search: 359/2, 359/567, 430 1- 2, 430/321, 283/72, 283/86, 283/94
• US Class Current: 359/2
• CPC Class Codes: B41M 3/14 Security printing securities B42D25/29
• CPC Class Codes: B42D 25/29 Securities; Bank notes
• CPC Class Codes: G03H 1/0011 for security or authentication holograms on information-bearing cards B42D25/328; testing papers with holograms G07D7/0032
• CPC Class Codes: G03H 1/02 Details of features involved during the holographic process; Replication of holograms without interference recording
• CPC Class Codes: G03H 1/0236 Form or shape of the hologram when not registered to the substrate, e.g. trimming the hologram to alphanumerical shape substrates bearing a hologram G03H1/0272
• CPC Class Codes: G03H 1/0244 Surface relief holograms replicating hologram without interference recording G03H1/0276
• CPC Class Codes: G03H 1/0256 having specific functional layer
• CPC Class Codes: G03H 1/028 by embossing
• CPC Class Codes: G03H 1/18 Particular processing of hologram record carriers, e.g. for obtaining blazed holograms photographic processing in general G03C, G03D
• CPC Class Codes: G03H 2001/0016 Covert holograms or holobjects requiring additional knowledge to be perceived, e.g. holobject reconstructed only under IR illumination microholograms G03H2230/10
• CPC Class Codes: G03H 2001/187 Trimming process, i.e. macroscopically patterning the hologram shape of hologram G03H1/0236
• CPC Class Codes: G03H 2001/188 Demetallisation, i.e. removing the enhancing metallic layer enhancement layer G03H2250/36
• CPC Class Codes: G03H 2210/53 Coded object not directly interpretable, e.g. encrypted object, barcode
• CPC Class Codes: G03H 2250/10 arranged to be transferred onto a carrier body adhesive layer G03H2250/35
• CPC Class Codes: G03H 2250/12 Special arrangement of layers
• CPC Class Codes: G03H 2250/34 Colour layer
• CPC Class Codes: G03H 2250/36 Conform enhancement layer
• CPC Class Codes: G03H 2250/40 Printed information overlapped with the hologram
• CPC Class Codes: G03H 2250/42 Reflective layer G03H2250/36 takes precedence

Abstract

A security device has a substrate formed with a surface relief defining an optically variable effect generating structure. At least two different reflection enhancing materials are provided on, or on the same side of, substrate with respect to the surface relief, whereby the optically variable effect can be viewed against a background defined by the reflection enhancing materials.

Claims

1. A security device, comprising:

a substrate formed with a surface relief defining an optically variable effect generating structure; and

at least two different opaque reflection enhancing materials, at least one of which is discontinuous, on the same side of the substrate with respect to the surface relief, each of the at least two reflection enhancing materials having the surface relief profile and having different hues, whereby the optically variable effect can be viewed against a background defined by the at least two reflection enhancing materials.

2. A device according to claim 1, wherein the surface relief defines at least one of a holographic image and a diffraction grating generating microstructure.

3. A device according to claim 1, wherein the at least two opaque reflection enhancing materials contact said surface relief.

4. A device according to claim 1, wherein the at least two opaque reflection enhancing materials are provided in respective, different layers on the substrate.

5. A device according to claim 4, wherein at least one transparent layer having the surface relief profile is provided between the opaque reflection enhancing materials.

6. A device according to claim 5, wherein the at least one transparent layer between the opaque reflection enhancing materials is a metal oxide having dielectric properties.

7. A device according to claim 1, wherein the at least two opaque reflection enhancing materials are discontinuous.

8. A device according to claim 1, further comprising an ink layer between the surface relief and at least one of the at least two opaque reflection enhancing materials.

9. A device according to claim 1, wherein at least one of the at least two opaque reflection enhancing materials is provided at least in part in a predetermined pattern.

10. A device according to claim 9, wherein the predetermined pattern is defined by dots or lines having a regular periodicity.

11. A device according to claim 10, wherein at least one of the at least two opaque reflection enhancing materials is provided in a form so as to define a covert image, which is viewable with a microlens array, lenticular array, or other appropriate optical decoder matched to the periodicity.

12. A device according to claim 9, wherein at least one of the at least two opaque reflection enhancing materials is provided such that its optical density varies in one or more lateral dimensions.

13. A device according to claim 1, wherein no opaque reflection enhancing material is provided on a border region of the substrate.

14. A device according to claim 1, wherein at least one of the at least two opaque reflection enhancing materials is a metal.

15. A device according to claim 14, wherein the metal is one of aluminum and copper or copper rich alloy.

16. A device according to claim 15, wherein the metal has been demetallised using an acidic solution based on hydrochloric, sulphuric or nitric acid.

17. A device according to claim 14, wherein the metal is provided in a pattern which defines a rf resonant circuit.

18. A device according to claim 14, wherein each of the at least two opaque reflection enhancing materials are metals separated by an insulating layer to define a capacitance.

19. A device according to claim 1, further comprising a printed image on the surface relief.

20. A document or article of value carrying a security device according to claim 1.

21. A device according to claim 1, wherein each of the at least two opaque reflection enhancing materials comprise metals or alloys.

22. A device according to claim 21, wherein the at least two opaque reflection enhancing materials are discontinuous.

23. A device according to claim 21, wherein the at least two opaque reflection enhancing materials have been vacuum deposited.

24. A device according to claim 9, wherein the predetermined pattern is at one of a bar code and indicia.