Holographic diffraction grating patterns and methods for creating the same

• US 5,291,317 A
• Filed: 07/12/1990
• Issued: 03/01/1994
• Est. Priority Date: 07/12/1990
• Status: Expired due to Term

• Current Assignee: Illinois Tool Works Inc.
• Original Assignee: Applied Holographics Corporation
• Inventors: Newswanger, Craig
• Primary Examiner(s): Arnold, Bruce Y.
• Assistant Examiner(s): PARSONS, DAVID
• Application Number:
  US07/552,258
• Time in Patent Office: 1,328 Days
• Field of Search: 359/1, 359/22, 359/3, 359/15, 359/25, 359/566, 359/567, 359/558, 359/569, 359/572, 359/575, 359/28, 359/30
• US Class Current: 359/15
• CPC Class Codes: G02B 5/1842 Gratings for image generation G02B5/1847 takes precedence
• 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 1/028 by embossing
• CPC Class Codes: G03H 1/0476 Holographic printer G03H1/268 takes precedence
• CPC Class Codes: G03H 1/265 Angle multiplexing; Multichannel holograms G03H1/268 takes precedence
• CPC Class Codes: G03H 1/268 Holographic stereogram
• CPC Class Codes: G03H 2001/0055 in advertising or decorative art
• CPC Class Codes: G03H 2001/0482 Interference based printer
• CPC Class Codes: G03H 2001/0497 Dot matrix holograms
• CPC Class Codes: G03H 2210/52 Alphanumerical
• CPC Class Codes: G03H 2224/02 Mechanical means, e.g. diamond tool
• CPC Class Codes: G03H 2230/10 Microhologram not registered to the substrate
• CPC Class Codes: G03H 2250/10 arranged to be transferred onto a carrier body adhesive layer G03H2250/35
• CPC Class Codes: G03H 2260/61 Producing material deformation
• CPC Class Codes: G03H 2270/24 Having particular size, e.g. microscopic

Abstract

Methods for creating a plurality of holographic diffraction grating patterns in a raster scan fashion. In accordance with the method, the desired pattern is made up of a large plurality of individual spots, each spot comprising a holographic diffraction grating of a predetermined grating spacing and angular orientation for that spot. Variation of the angular orientation and/or grating spacing between spots and/or groups of spots provide the desired holographic effect. The spot locations may vary as desired, including locations drawing out a desired pattern, and two-dimensional orthogonal matrices in which a pattern is drawn by variations between spots or group of spots as in a raster scan type image. Various embodiments and methods for creating the same are disclosed.

Claims

1. A method of forming holographic diffraction grating patterns comprising the steps of:

(a) providing a member having a photosensitive region thereon;

(b) generating a pair of beams from a diffraction grating;

(c) directing said beams with a lens to a spot on said photosensitive region such that a holographic diffraction grating is created within said spot of said photosensitive region; and

,

(d) repeating step (c) a plurality of times for a plurality of spots having different locations on the photosensitive region to define a pattern thereon.

2. The method of claim 1 wherein at least some of the holographic diffraction gratings contain lines that extend in different directions.

3. The method of claim 1 wherein at least some of the holographic diffraction gratings are varied by varying an angle of said beams measured from an axis perpendicular to a surface of the photosensitive region.

4. The method of claim 1 wherein in steps (c) and (d), said holographic diffraction gratings are created in a manner so as to trace out a specific decorative pattern.

5. The method of claim 1 wherein in steps (c) and (d), the holographic diffraction gratings are created in a raster scan pattern.

6. The method of claim 1 wherein the spots are round.

7. The method of claim 1 wherein the spots are polygonal.

8. The method of claim 1 wherein in steps (c) and (d), the length of exposure of said beams is varied between at least some spots.

9. A method of forming holographic diffraction grating patterns, comprising the steps of:

a) directing a beam of light through a diffraction grating to create a pair of pattern beams;

b) focusing said pattern beams onto a first spot of a photosensitive member such that a holographic diffraction grating is created onto said first spot of said photosensitive member;

c) moving said photosensitive member such that a second spot can be exposed to said pattern beams;

d) rotating said diffraction grating; and

e) directing a beam of light through said diffraction grating, to create a pair of pattern beams which are focused onto said photosensitive member such that a second holographic diffraction grating is created onto said second spot.

10. The method of claim 9 wherein said diffraction grating is rotated so that said first spot has lines that extend in a different direction from lines in said second spot.

11. The method of claim 9 wherein the holographic diffraction grating is varied between the first spot and the second spot by varying an angle of said beams measured from an axis perpendicular to a surface of the photosensitive region.

12. The method of claim 9 wherein the holographic diffraction grating is varied between the first spot and the second spot by varying the spacing of the lines of the diffraction grating.

13. The method of claim 9 wherein the holographic diffraction grating is varied between the first spot and the second spot by varying the angle thereof about an axis perpendicular to the local surface of the photosensitive region and at the same or other times varying the spacing of the lines of the diffraction grating.

14. The method of claim 9 wherein the holographic diffraction gratings are created in a predetermined manner.

15. The method of claim 9 wherein steps (c) through (e) are repeated in a number of times such that the spots trace out a specific decorative pattern.

16. The method of claim 9 wherein the spots are impressed in a raster scan pattern.

17. The method of claim 9 wherein the spots are round.

18. The method of claim 9 wherein the spots are polygonal.

19. The method of claim 9 wherein the length of exposure of said beams is varied between the first and second spots spots.