Film having transmissive and reflective properties

• US 6,473,220 B1
• Filed: 01/26/2000
• Issued: 10/29/2002
• Est. Priority Date: 01/22/1998
• Status: Expired due to Fees

• Current Assignee: Rambus Delaware LLC (Rambus Inc.)
• Original Assignee: Trinium Technologies
• Inventors: Lubart, Neil D., Clikeman, Richard W., Mayfield, Charles Ronald
• Primary Examiner(s): Dang, Hung Xuan
• Application Number:
  US09/491,450
• Time in Patent Office: 1,007 Days
• Field of Search: 359/245, 359/247, 359/252, 359/253, 359/237
• US Class Current: 359/247
• CPC Class Codes: G02B 5/20 Filters polarising elements G02B5/30
• CPC Class Codes: G02B 6/0038 Linear indentations or grooves, e.g. arc-shaped grooves or meandering grooves, extending over the full length or width of the light guide
• CPC Class Codes: G02B 6/0051 Diffusing sheet or layer
• CPC Class Codes: G02B 6/0053 Prismatic sheet or layer; Brightness enhancement element, sheet or layer
• CPC Class Codes: G02B 6/0065 Manufacturing aspects; Material aspects
• CPC Class Codes: G02F 1/133555 Transflectors

Abstract

A film which simultaneously maximizes light reflectivity from one side of the film while maximizing light transmissivity from the opposite side of the film. This is achieved by configuring the film with distinct regions of transparency and reflectivity where the extended boundary of the reflective region is shaped into a light funnel/pipe and where periodically placed discrete and/or extended/continuous shapes are created (such as extended triangular indentations, or discrete shapes such as a cone, a pyramid, or any polyhedron). The reflective region is composed of mirror-like material such as aluminum or silver, but may be a composite paste, a composite material, or multiple materials with different refractive indices or reflective qualities. In some embodiments, the reflective material is embedded in the transparent material such that the base of each shape is approximately parallel to and coincident with, or slightly recessed from the surface of the transparent material. In other embodiments, the reflective material is embedded in the transparent material such that the base of each shape is set at an angle to the surface of the transparent material. The transparent material will be continuous on at least one surface such that the transparent material forms the boundary for the film. The reflective regions and the transmissive regions may be configured according to application specification.

Claims

1. A transflector having means for reflecting of light impingent thereon from a first direction, and having means for transmitting of light arriving from a direction opposing to said first direction wherein the sum of the percent of light being reflected relative to the light coming from the first direction, and the percent of light being transmitted relative to the amount of light coming from the opposing direction, is greater than 100 percent.

2. The transflector of claim 1 wherein said transflector has a first surface, wherein said reflecting means comprise a reflective material covering at least a part of said first surface.

3. The transflector of claim 2 wherein said means for transmitting light comprises one or more structures associated with said reflective material.

4. The transflector of claim 3 wherein said structure comprise a base and sidewalls, said base associated with said reflective material.

5. The transflector of claim 4 wherein said sidewalls are at an angle relative to said first surface sufficient to reflect light striking said structure from said opposing direction through said first surface.

6. The transflector of claim 5 wherein said structure is a polyhedron.

7. The transflector of claim 5 wherein said structure is a cone.

8. The transflector of claim 5 wherein said angle of said sidewall is between 83 degrees and less than 90 degrees.

9. The transflector of claim 5 wherein the sidewall shape is selected from the group comprising planer, concave, convex, or mixtures thereof.

10. The transflector of claim 5 wherein the number of said structures is greater than one, and wherein said reflective material covers said base of said structures, and is discontinuous with respect to said first surface.

11. The transflector of claim 10 wherein the base of said structure is a elongated rectangle, said rectangle running in one direction across said first surface.

12. The transflector of claim 11 wherein said rectangle of said base has a length and a width, said width being smaller than said length, and having a value of between about 2 and 200 microns.

13. The transflector of claim 12 wherein said structure has a height, and the ratio of said height to said width of said base is between about 6 and 22.

14. The transflector of claim 12 wherein the base of the structures are separated by a distance, said distance being about 0.1 to 1.0 times one half of the width of said base.

15. The transflector of claim 12 wherein the structures are parallel to each other.

16. The transflector of claim 12 wherein the base of said structure is at an angle to said first surface, and at least part of said base extends above said first surface.

17. The transflector of claim 1 wherein said transflector comprises a light transmitting material having a first surface, said first surface having one or more indentations.

18. The transflector of claim 17 wherein said indentations have sidewalls communicating with said first surface.

19. The transflector of claim 18 wherein said sidewalls are at an angle relative to said first surface of between about 83 degrees and less than 90 degrees.

20. The transflector of claim 19 wherein the indentation has the shape of a polyhedron.

21. The transflector of claim 18 wherein the indentation is filled with a reflective material.

22. The transflector of claim 18 wherein the indentation is filled with a material having a different index of refraction relative to the light transmitting material.

23. The transflector of claim 21 wherein the reflective material is selected from the group consisting of aluminum, silver, gold or combinations thereof.

24. The transflector of claim 18 wherein said reflective means is a reflective material, said material covering said indentation on said first surface.

25. The transflector of claim 18 wherein said indentation forms one or more grooves in said light transmitting material, said grooves running in one direction across said first surface.

26. The transflector of claim 25 wherein the grooves have a cross sectional shape, said cross sectional shape being triangular.

27. The transflector of claim 26 wherein said indentation relative to said first surface is in the shape of an elongated rectangle having a width and a length, said length being longer than said width.

28. The transflector of claim 27 wherein said width of said rectangle has a value of between about 2 and 200 microns.

29. The transflector of claim 27 wherein said indentation has a depth, and the ratio of said depth to said width of said indentation is between about 6 and 22.

30. The transflector of claim 27 wherein said indentations are separated by a distance, said distance being about 0.1 to 1.0 times one half of the width of said indentation.

31. The transflector of claim 30 wherein the indentations are parallel to each other.

32. A light transmitting material capable of transmitting light in a first direction, having a first surface, said first surface having reflecting means for reflecting a percentage but not all of the light striking said first surface from an opposing direction, and having one or more reflecting structures associated with said reflector means, said structures having sidewalls extending from said first surface toward said first direction, said sidewalls having an internal angle relative to said first surface of less than 90 degrees, said angle sufficient to reflect light striking said sidewalls from said first direction through said first surface such that a percentage of light from said first direction passes through said first surface, wherein the sum of the percentage of light being reflected relative to the light coming from said opposing direction, and the percentage of light being transmitted relative to the amount of light coming from said first direction is greater than 100 percent.

33. The light transmitting material of claim 32 wherein said reflecting structures are formed in the light transmitting material by treating said material in a manner sufficient to create a different index of refraction from said light transmitting material.

34. A non-emissive display device, said device containing a light transmitting material, said light transmitting material capable of transmitting light in a first direction and having a first surface, said first surface having reflecting means for reflecting a percentage but not all of the light striking said first surface from an opposing direction, and having one or more reflecting structures associated with said reflector means, said structures having sidewalls extending from said first surface toward said first direction, said sidewalls having an internal angle relative to said first surface of less than 90 degrees, said angle sufficient to reflect light striking said sidewalls from said first direction through said first surface such that a percentage of light from said first direction passes through said first surface, wherein the sum of the percentage of light being reflected relative to the light coming from said opposing direction, and the percentage of light being transmitted relative to the amount of light coming from said first direction is greater than 100 percent.

35. An electromagnetic radiation transmitting material capable of transmitting radiation in a first direction, having a first surface, said first surface having reflecting means for reflecting a percentage but not all of said radiation striking said first surface from an opposing direction, and having one or more reflecting structures associated with said reflector means, said structures having sidewalls extending from said first surface toward said first direction, said sidewalls having an internal angle relative to said first surface of less than 90 degrees, said angle sufficient to reflect said radiation striking said sidewalls from said first direction through said first surface such that a percentage of radiation from said first direction passes through said first surface, wherein the sum of the percentage of said radiation being reflected relative to said radiation coming from said opposing direction, and the percentage of said radiation being transmitted relative to the amount of said radiation coming from said first direction is greater than 100 percent.

36. The electromagnetic radiation transmitting material of claim 35 wherein the electromagnetic radiation is selected from the group comprising ultraviolet, visible, infrared and microwave radiation or mixtures thereof.

37. A solar collection device, said device containing a solar radiation transmitting material capable of transmitting solar radiation in a first direction to a solar collector, wherein said collector reflects a portion of said solar radiation back to said material in an opposing direction, said material having a first surface, said first surface having reflecting means for reflecting a percentage but not all of said solar radiation striking said first surface from said opposing direction, and having one or more reflecting structures associated with said reflector means, said structures having sidewalls extending from said first surface toward said first direction, said sidewalls having an internal angle relative to said first surface of less than 90 degrees, said angle sufficient to reflect said solar radiation striking said sidewalls from said first direction through said first surface such that a percentage of solar radiation from said first direction passes through said first surface, wherein the sum of the percentage of said solar radiation being reflected relative to said solar radiation coming from said opposing direction, and the percentage of said solar radiation being transmitted relative to the amount of said solar radiation coming from said first direction is greater than 100 percent.

38. A solar collection device, said device containing a grid and a solar collector, wherein solar radiation passes in a first direction through said grid to said solar collector, and a portion of said solar radiation is reflected from said collector to said grid in an opposing direction, said grid having a first surface, said first surface having reflecting means for reflecting a percentage but not all of the solar radiation striking said first surface from said opposing direction, and having one or more reflecting structures associated with said reflector means, said structures having sidewalls extending from said first surface toward said first direction, said sidewalls having an internal angle relative to said first surface of less than 90 degrees said angle sufficient to reflect said solar radiation striking said structure from said first direction through said first surface such that a percentage of said solar radiation from said first direction passes through said first surface, wherein the sum of the percentage of said solar radiation being reflected relative to the said solar radiation coming from the opposing direction, and the percentage of said solar radiation being transmitted relative to the amount of said solar radiation coming from said first direction is greater than 100 percent.

39. The solar collection device of claim 38 wherein said solar collector generates additional radiation, said additional radiation striking said first surface from said opposing direction, wherein a portion of said additional radiation is reflected back to said solar collector.