Non-continuous holograms, methods of making them and articles incorporating them

• US 5,145,212 A
• Filed: 12/23/1988
• Issued: 09/08/1992
• Est. Priority Date: 02/12/1988
• Status: Expired due to Term

• Current Assignee: Viavi Solutions, Inc. (Lumentum Holdings Inc.)
• Original Assignee: American Bank Note Holographics, Inc. (Lumentum Holdings Inc.)
• Inventors: Mallik, Donald W.
• Primary Examiner(s): Bell, Paul A.
• Application Number:
  US07/291,247
• Time in Patent Office: 1,355 Days
• Field of Search: 283/72, 283/86, 283/904, 283/91, 283/94, 352/2
• US Class Current: 283/86
• 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 1/0236 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 1/265 Angle multiplexing; Multichannel holograms G03H1/268 takes precedence
• CPC Class Codes: G03H 2001/187 Trimming process, i.e. macroscopically patterning the hologram shape of hologram G03H1/0236
• CPC Class Codes: G03H 2001/2223 Particular relationship between light source, hologram and observer
• CPC Class Codes: G03H 2001/2228 adapted for reflection and transmission reconstruction
• CPC Class Codes: G03H 2001/2615 in physical contact, i.e. layered holograms
• CPC Class Codes: G03H 2223/25 Index matching material
• 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 2250/36 Conform enhancement layer
• CPC Class Codes: G06K 19/16 the marking being a hologram or diffraction grating
• CPC Class Codes: Y10S 283/904 Credit card

Abstract

Non-continuous reflective holograms or diffraction gratings are provided in various forms for authenticating documents and things, and for decorative and product packaging applications. In one specific authentication application, such a hologram or diffraction grating is firmly attached to a surface that contains visual information desired to be protected from alteration. Examples of such information include written personal data and photograph on a passport, driver'"'"'s license, identity card and the like. The reflective discontinuous hologram is formed in a pattern that both permits viewing the protected information through it and the viewing of an authenticating image or other light pattern reconstructed from it in reflection. In another specific authentication application, a non-transparent structure of two side-by-side non-continuous holograms or diffraction patterns, each reconstructing a separate image or other light pattern, increases the difficulty of counterfeiting the structure.

Claims

1. In an article having a substrate with visual information carried on at least a portion of one surface area thereof, and a holographic diffractive device attached to said one surface, the improvement comprising said device being attached to said at least one substrate surface area over at least a portion of said visual information, said device being substantially transparent across said at least a portion of said visual information except for a plurality of discontinuous reflective portions across an area thereof that, when illuminated with light, reflect at least a portion of such light to form a reconstruction of a light pattern recorded on said device, said discontinuous reflective device portions having a spacing in excess of 25 such portions per inch in at least one direction across said device area, thereby to both render said visual information visible through the device and allow viewing of the light pattern reconstructed from the device.

2. The improved article according to claim 1 wherein said discontinuous reflective device portions have a spacing in excess of 85 such portions per inch in at least one direction across said device area, whereby the size of the discontinuous reflective device portions and their spacing is such that said portions are substantially invisible at a normal reading distance.

3. The improved article according to claim 1 wherein said discontinuous reflective device portions have a density such that the total area covered by said reflective device portions is within a range of from ten to ninety percent of said device area.

4. The improved article according to claim 1 wherein said device includes a continuous surface relief pattern across at least said device area and containing information which forms a light pattern formed upon illuminating the device with polychromatic light, and wherein said discontinuous reflective device portions are formed of a pattern of substantially reflective areas applied to the surface relief pattern.

5. The improved article according to claim 1 wherein the visual information which is visible through said device includes characters representing information about an individual and a photograph of that individual.

6. The improved article according to claim 1 wherein said substrate includes at least one opaque surface area that carries at least some of said visual information.

7. The improved article according to claim 1 wherein said discontinuous reflective device portions have a spacing within a range of substantially 85 to 200 such portions per inch in at least one direction across said device area, and with a density such that the total area covered by said reflective device portions is within a range of from 30 to 60 percent of said device area.

8. The improved article according to claim 1 wherein said discontinuous reflective device portions have a spacing within a range of substantially 65 to 130 such portions per inch in at least one direction across said device area, and with a density such that the total area covered by said reflective device portions is within a range of from 15 to 30 percent of said device area.

9. The improved article according to claim 1 wherein said discontinuous reflective device portions have a spacing within a range of substantially 65 to 200 such portions per inch in at least one direction across said device area, and with a density such that the total area covered by said reflective device portions is within a range of from 15 to 60 percent of said device area.

10. The improved article according to any one of claims 3, 7, 8 or 9 wherein said reflective device portions are substantially circularly shaped spots.

11. The improved article according to any one of claims 1, 3, 5, or 9 wherein said device includes a hologram characterized by the image reconstructed from said surface relief pattern having a three dimensional aspect.

12. The protected document according to any one of claims 1, 3, 5, or 9 wherein said device is attached over substantially the entire extent of said article one surface area.

13. A document having at least some visual information thereon protected from alteration, comprising a holographic diffractive device firmly attached to said document over said at least some visual information, said device comprising a continuous surface relief pattern across a surface area of a substantially transparent layer, said surface relief pattern containing information of an image or other light pattern, and a discontinuous pattern carried by said surface relief pattern or at least 25 substantially completely reflective material regions per inch in at least one direction across at least a portion of said surface area and said at least some visual information, said device being characterized by permitting, when illuminated with light, both the viewing of said at least some visual information therethrough and an image or other light pattern reconstructed from said surface relief pattern.

14. The protected document according to claim 13 wherein said reflective material consists primarily of a two-dimensional array of spots of said reflective material having a periodic spacing in excess of 25 spots per inch across said at least a portion of said device surface area in any direction and a density such that said spots cover a range of from ten to ninety percent of said at least a portion of the device surface area.

15. The protected document according to claim 13 wherein said discontinuous pattern of reflective material consists essentially of individual discrete areas of reflective material having a spacing in excess of 85 such portions per inch in at least one direction across said device area, whereby said individual discrete areas are small enough to result in them not being resolved by a viewer observing the visual information covered by the device at a normal viewing distance.

16. The protected document according to claim 13 wherein said document is any of a passport, personal identification card or driver'"'"'s license.

17. The protected document according to claim 13 wherein said device is further characterized by permitting reconstruction of said image or other light pattern with a maximum brightness substantially only when said document is reoriented from a normal position for viewing said visual information on the document.

18. The protected document according to claim 13 wherein said device is further characterized by permitting viewing of said image or other light pattern reconstructed from said surface relief pattern substantially only upon the document being tilted by the viewer to a position where the document is observed other than straight on.

19. The protected document according to claim 13 wherein the visual information on the document is oriented for observation with the document in a first rotatable position with respect to a line of vision from an observer and the document, and wherein said device is further characterized by permitting viewing of said image or other light pattern reconstructed from said surface relief pattern substantially only upon the document being rotated about said line of vision through an angle to a second rotatable position.

20. The protected document according to claim 19 wherein said first and second rotatable positions are substantially ninety degrees apart from each other.

21. The protected document according to claim 13 wherein said reflective material is arranged in a pattern consisting primarily of a two-dimensional array of spots of said reflective material having a spacing within a range of substantially 85 to 200 spots per inch across said at least a portion of the device surface area and a density such that said spots cover substantially from 30 to 60 percent of said at least a portion of the device surface area.

22. The protected document according to claim 13 wherein said reflective material is arranged in a pattern consisting primarily of a two-dimensional array of spots of said reflective material having a spacing within a range of substantially 65 to 130 spots per inch across said at least a portion of the device surface area and a density such that said spots cover substantially from 15 to 30 percent of said at least a portion of the device surface area.

23. The protected document according to claim 13 wherein said reflective material is arranged in a pattern consisting primarily of a two-dimensional array of spots of said reflective material having a spacing within a range of substantially 65 to 200 spots per inch across said at least a portion of the device surface area and a density such that said spots cover substantially from 15 to 60 percent of said at least a portion of the device surface area.

24. The protected document according to any one of claims 14, 21, 22 or 23 wherein said spots are substantially circular in shape.

25. The protected document according to any one of claims 14, 21, 22 or 23 wherein said spots are made of an aluminum material and are of a thickness substantially within a range of from 200 to 400 Angstroms.

26. The protected document according to any one of claims 13, 14, 15, 16, or 23 wherein said device includes a hologram characterized by the image reconstructed from said surface relief pattern having a three dimensional aspect.

27. The protected document according to any one of claims 13, 14, 15, 16, or 23 wherein said device is attached to said document with its said surface relief pattern and reflective material positioned on a side of said transparent layer which faces said document.

28. The protected document according to any one of claims 13, 14, 15, 16, or 23 wherein said device is attached over substantially the entire extent of said document.

29. A composite structure, comprising:

a substrate containing visual information across at least a portion of a first surface thereof,

a substantially transparent layer attached to said first substrate surface over at least a portion of said visual information,

a relief pattern formed substantially continuously across at least a portion of a surface of said layer that faces said first substrate surface, said surface relief pattern being characterized by diffracting incident light into a recognizable image or other light pattern, and

a discontinuous, substantially regular pattern of at least sixty-five reflective and substantially opaque material areas per inch extending in at least one direction across said substrate surface over said at least a portion of said visual information and positioned between said substrate and said substantially transparent layer, said reflective areas covering less than 60 per-cent of said at least a portion of said visual information,

thereby to render viewable in light reflected from the composite structure both said recognizable image or other light pattern and the substrate visual information.

30. The composite structure according to claim 29 wherein said reflective device portions are substantially circularly shaped spots in a two-dimensional pattern across said substrate surface.

31. The composite structure according to claim 30 wherein said surface relief pattern is a replica of a hologram and wherein the recognizable image or other light pattern diffracted therefrom includes an image having a three dimensional aspect.

32. The composite structure according to claim 30 wherein said layer is attached over substantially all of said first substrate surface.

33. The composite structure according to claim 30 wherein the visual information carried by said at least a portion of the first surface of the substrate is arranged to be viewed when the structure is oriented in one direction with respect to the viewer and wherein said surface relief pattern is further characterized by forming said image or other light pattern with a maximum brightness substantially only when the structure is oriented in a second position with respect to the viewer, said second position being significantly different from said first position.

34. The composite structure according to any one of claims 29-33 wherein said substrate is one of a group including a passport, personal identification card and driver'"'"'s license.

35. The combination structure according to any one of claims 29-33 wherein said reflective material areas are substantially totally reflective.