Apparatus for enhancing the brightness of an image and method of making the same

• US 5,475,533 A
• Filed: 08/02/1993
• Issued: 12/12/1995
• Est. Priority Date: 08/02/1993
• Status: Expired due to Term

• Current Assignee: Printpack Illinois, Inc. (Printpack Holdings Incorporated)
• Original Assignee: Applied Physics Research, L.P.
• Inventors: Shearman, Samuel D., Hurt, Mark J., Steenblik, Richard A.
• Primary Examiner(s): Epps, Georgia Y.
• Assistant Examiner(s): Robbins, Thomas
• Application Number:
  US08/101,560
• Time in Patent Office: 862 Days
• Field of Search: 359/454, 359/455, 359/459, 359/542, 359/619, 359/620, 359/621, 359/622, 359/623, 359/624, 359/625, 359/626, 359/627, 359/628
• US Class Current: 359/628
• CPC Class Codes: G02B 5/00 Optical elements other than lenses light guides G02B6/00; optical logic elements G02F3/00
• CPC Class Codes: G02B 5/021 the diffusion taking place at the element's surface, e.g. by means of surface roughening or microprismatic structures
• CPC Class Codes: G02B 5/0215 the surface having a regular structure
• CPC Class Codes: G02B 5/0268 characterized by the fabrication or manufacturing method
• CPC Class Codes: G02B 5/0284 used in reflection

Abstract

A light control material generally comprising a transparent substrate for carrying a print or photographic image and a plurality of focusing elements which provide a field of view over which the brightness of the print or photographic image is enhanced. The field of view is controlled by the geometry of the focusing elements including radius, width, and degree of symmetry. By providing a field of view over which the brightness of the image is enhanced, the image may be viewed at angles which avoid the angles of specular reflection, which are usually seen as unwanted glare. Furthermore, selected portions of an image may be brightness enhanced more than others or selected portions may be brightness enhanced while others are not.

Claims

1. A light control material for enhancing the brightness of a print or photographic image, said light control material comprising:

a transparent substrate suitable for carrying the print or photographic image;

a plurality of focusing elements formed in a polymer layer, said plurality of focusing elements having predetermined physical characteristics, wherein said polymer layer is bonded to said transparent substrate and wherein, said plurality of focusing elements control light impinging on said focusing elements in accordance with said physical characteristics such that a field of view is provided over which the brightness of the print or photographic image is enhanced.

2. A light control material for enhancing the brightness of a print or photographic image according to claim 1 wherein said focusing elements are coated with a reflective layer of metal and wherein said light control material operates in a reflective mode.

3. A light control material for enhancing the brightness of a print or photographic image according to claim 1 wherein said focusing elements are transparent and wherein said light control material operates in a transmissive mode.

4. A light control material for enhancing the brightness of a print or photographic image according to claim 1 wherein said physical characteristics include radius, width, and degree of symmetry.

5. A light control material for enhancing the brightness of a print or photographic image according to claim 1 wherein said focusing elements are symmetric in shape.

6. A light control material for enhancing the brightness of a print or photographic image according to claim 1 wherein said focusing elements are asymmetric in shape.

7. A light control material for enhancing the brightness of a print or photographic image according to claim 2 wherein the focusing elements are concave with respect to the print or photographic image.

8. A light control material for enhancing the brightness of a print or photographic image according to claim 2 wherein said focusing elements are convex with respect to the print or photographic image.

9. A light control material for enhancing the brightness of a print or photographic image according to claim 3 wherein said focusing elements are concave with respect to the print or photographic image.

10. A light control material for enhancing the brightness of a print or photographic image according to claim 3 wherein said focusing elements are convex with respect to the print or photographic image.

11. A light control material for enhancing the brightness of a print or photographic image according to claim 1 wherein the image can be viewed over the field of view from angles which avoid angles of specular reflection from said transparent substrate.

12. A light control material for enhancing the brightness of a print or photographic image according to claim 11 wherein the field of view does not include the angles of specular reflection.

13. A light control material for enhancing the brightness of a print or photographic image according to claim 11 wherein the field of view includes at least some of the angles of specular reflection.

14. A light control material for enhancing the brightness of a print or photographic image according to claim 11 wherein the enhanced brightness of the image is much greater than the specular reflection such that glare is reduced.

15. A light control material for enhancing the brightness of a print or photographic image according to claim 1 wherein said light control material further comprises at least one focusing element formed in said polymer layer in addition to said plurality of focusing elements and wherein said at least one focusing element has physical characteristics which are different from the physical characteristics of said plurality of focusing elements and wherein said at least one focusing element controls light impinging thereon in accordance with the physical characteristics of said at least one focusing element to provide a field of view which is different from the field of view provided by said plurality of focusing elements.

16. A light control material for enhancing the brightness of a print or photographic image according to claim 15 wherein said at least one focusing element is asymmetric in shape and wherein said plurality of focusing elements are symmetric in shape and wherein said at least one focusing element and said plurality of focusing elements provide a focusing element pattern which reduces diffractive effects.

17. A light control material for enhancing the brightness of a print or photographic image according to claim 16 wherein the different fields of view provide a gradual change in said brightness of said image.

18. A light control material for enhancing the brightness of a print or photographic image according to claim 15 wherein the brightness of the image is enhanced over the different fields of view and wherein the image can be viewed over the fields of view from angles which avoid angles of specular reflection from said transparent substrate.

19. A light control material for enhancing the brightness of a print or photographic image according to claim 18 wherein the fields of view do not include the angles of specular reflection.

20. A light control material for enhancing the brightness of a print or photographic image according to claim 18 wherein at least one of said fields of view include at least some of the angles of specular reflection.

21. A light control material for enhancing the brightness of a print or photographic image according to claim 18 wherein the enhanced brightness of the image over the fields of view is much greater than the specular reflection such that glare is reduced.

22. A light control material, for enhancing the brightness of a print or photographic image according to claim 15 wherein said at least one focusing element and said plurality of focusing elements are symmetric in shape and wherein the image is brightness enhanced to different degrees over the different fields of view and wherein the physical characteristics of the focusing elements determine the brightness of the image over the fields of view.

23. A light control material for enhancing the brightness of an image, said light control material comprising:

a plurality of focusing elements formed in a polymer layer, said plurality of focusing elements having predetermined physical characteristics, and a reflective layer of metal covering said focusing elements thereby making said focusing elements reflective, wherein said plurality of focusing elements control light impinging on said focusing elements in accordance with said physical characteristics to provide a field of view over which the brightness of said image is enhanced.

24. A light control material for enhancing the brightness of an image according to claim 23 wherein said physical characteristics include radius, width, and degree of symmetry.

25. A light control material for enhancing the brightness of an image according to claim 23 wherein said focusing elements are symmetric in shape.

26. A light control material for enhancing the brightness of an image according to claim 23 wherein said focusing elements are asymmetric in shape.

27. A light control material for enhancing the brightness of an image according to claim 23 wherein the focusing elements are convex in shape with respect to the print or photographic image.

28. A light control material for enhancing the brightness of an image according to claim 23 wherein the focusing elements are concave in shape with respect to the print or photographic image.

29. A light control material for enhancing the brightness of an image according to claim 23 wherein said light control material further comprises at least one focusing element formed in said polymer layer in addition to said plurality of focusing elements and wherein said at least one focusing element has physical characteristics which are different from the physical characteristics of said plurality of focusing elements and wherein said at least one focusing element controls light impinging thereon in accordance with the physical characteristics of said at least one focusing element to provide a field of view which is different from the field of view provided by said plurality of focusing elements.

30. A light control material for enhancing the brightness of an image according to claim 29 wherein said at least one focusing element is asymmetric in shape and wherein said plurality of focusing elements are symmetric in shape and wherein said at least one focusing element and said plurality of focusing elements provide a focusing element pattern which reduces diffractive effects.

31. A light control material for enhancing the brightness of an image according to claim 30 wherein the different fields of view provide a gradual change in said brightness of said image.