Light redirecting films pattern of variable optical elements

• US 7,364,342 B2
• Filed: 07/11/2006
• Issued: 04/29/2008
• Est. Priority Date: 02/23/1999
• Status: Expired due to Fees

• Current Assignee: Innovative Display Technologies LLC (Acacia Research Corporation)
• Original Assignee: Solid State Opto Limited (Global Lighting Technologies Inc.)
• Inventors: McCollum, Timothy A., Parker, Jeffery R., Ezell, Robert M.
• Primary Examiner(s): Negron; Ismael
• Application Number:
  US11/484,063
• Publication Number:
  US 20060256577A1
• Time in Patent Office: 658 Days
• Field of Search: 362/615, 362/618, 362/619, 362/620, 362/624, 362/625, 362/626, 362/606, 362/608, 362/627, 385/131, 349/65, 349/69, 349/70
• US Class Current: 362/626
• CPC Class Codes: A61B 2090/309 using white LEDs
• CPC Class Codes: A61M 2021/0044 by the sight sense
• CPC Class Codes: A61M 21/02 for inducing sleep or relaxation, e.g. by direct nerve stimulation, hypnosis, analgesia for massage A61H; electrotherapy A61N, e.g. applying alternating or intermittent electric currents for producing anaesthesia A61N1/36021
• CPC Class Codes: A61N 2005/063 comprising light transmitting means, e.g. optical fibres
• CPC Class Codes: A61N 2005/0652 Arrays of diodes
• CPC Class Codes: A61N 5/0621 Hyperbilirubinemia, jaundice treatment
• CPC Class Codes: F21V 11/00 Screens not covered by groups F21V1/00, F21V3/00, F21V7/00 or F21V9/00 characterised by cooling arrangements F21V29/502
• CPC Class Codes: F21V 5/10 comprising photoluminescent material
• CPC Class Codes: G02B 6/0018 Redirecting means on the surface of the light guide
• CPC Class Codes: G02B 6/002 by shaping at least a portion of the light guide, e.g. with collimating, focussing or diverging surfaces
• CPC Class Codes: G02B 6/0021 for housing at least a part of the light source, e.g. by forming holes or recesses
• CPC Class Codes: G02B 6/0028 Light guide, e.g. taper
• CPC Class Codes: G02B 6/0031 Reflecting element, sheet or layer
• CPC Class Codes: G02B 6/0036 2-D arrangement of prisms, protrusions, indentations or roughened surfaces
• 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 6/0043 provided on the surface of the light guide
• CPC Class Codes: G02B 6/0053 Prismatic sheet or layer; Brightness enhancement element, sheet or layer
• CPC Class Codes: G02B 6/006 to produce indicia, symbols, texts or the like
• CPC Class Codes: G02B 6/0061 to provide homogeneous light output intensity
• CPC Class Codes: G02B 6/0065 Manufacturing aspects; Material aspects
• CPC Class Codes: G02B 6/0068 : Arrangements of plural sources, e.g. multi-colour light sources
• CPC Class Codes: H01H 2219/062 : Light conductor
• CPC Class Codes: H01H 2221/07 : transparent

Abstract

Light redirecting films and film systems include a thin optically transparent substrate having a pattern of individual optical elements of well defined shape on or in the substrate. At least some of the optical elements may vary at different locations on the substrate to redistribute or redirect light passing through the substrate.

Claims

1. A light redirecting film comprising a thin optically transparent substrate having a pattern of individual optical elements of well defined shape on or in the substrate, the optical elements being quite small in relation to a width and length of the substrate, at least some of the optical elements varying at different locations on the substrate to redistribute light passing through the substrate toward a direction normal to the substrate, wherein the substrate has multiple layers and at least some of the multiple layers have different indices of refraction.

2. The film of claim 1 wherein at least some of the optical elements vary in at least one of the following characteristics:

slope angle, density, position, orientation, height or depth, shape, and size, to tailor the film to the light output distribution of different backlights.

3. The film of claim 1 wherein at least some of the optical elements have a different beam profile at different locations on the substrate.

4. The film of claim 1 wherein the size and shape of the optical elements are tailored to redistribute more of the light emitted by a light source within a desired viewing angle.

5. The film of claim 1 wherein at least some of the optical elements overlap, intersect, or interlock each other.

6. The film of claim 1 wherein at least some of the optical elements are oriented at different angles across the substrate for redirecting the light along different axes.

7. The film of claim 1 wherein the size of at least some of the optical elements varies across the substrate.

8. The film of claim 1 wherein the shape of at least some of the optical elements varies across the substrate.

9. The film of claim 1 wherein the height or depth of at least some of the optical elements varies across the substrate.

10. The film of claim 1 wherein the position of at least some of the optical elements varies across the substrate.

11. The film of claim 1 wherein the density of the optical elements varies across the substrate.

12. The film of claim 1 wherein at least some of the optical elements vary in a predetermined pattern to redistribute light within a desired optical distribution.

13. The film of claim 1 wherein at least some of the optical elements have at least one curved surface and at least one planar surface.

14. The film of claim 1 wherein at least some of the optical elements are randomly distributed across the substrate.

15. The film of claim 1 wherein at least some of the optical elements have an angled surface that varies in area across the substrate.

16. The film of claim 1 wherein the individual optical elements are on opposite sides of the substrate.

17. The film of claim 1 wherein at least some of the optical elements include a combination of planar and curved surfaces, the ratio of the areas of the planar and curved surfaces being selected to produce a desired viewing angle.

18. The film of claim 1 in combination with a backlight including a panel surface having a light ray output distribution that varies at different locations on the panel surface, wherein the light redirecting film is in close proximity to the panel surface, and wherein the backlight includes perimeter lighting, and the optical elements are arranged in a pattern that is tailored to redistribute the light ray output distribution of the backlight that receives light from the perimeter lighting.

19. The film of claim 1 in combination with a backlight including a panel surface having a light ray output distribution that varies at different locations on the panel surface, wherein the light redirecting film is in close proximity to the panel surface, and wherein the backlight includes at least one corner light, and the optical elements are arranged in a radial type pattern that is tailored to redistribute the light ray output distribution of the backlight that receives light from the corner light.

20. The film of claim 1 in combination with a light source, wherein one side of the light redirecting film substrate is in close proximity to the light source with an air gap therebetween, and wherein at least some light that is emitted by the light source passes through the one side of the substrate and out an opposite side of the substrate to redistribute the light toward a direction normal to the substrate.

21. The film of claim 1 wherein the substrate has a coating to produce a specific effect.

22. The film of claim 21 wherein the coating is selective.

23. The film of claim 1 wherein at least some of the optical elements have at least two different shaped surface parameters.

24. The film of claim 23 wherein one of the different shaped surfaces is curved, and the other of the different shaped surfaces is planar.

25. The film of claim 1 wherein at least some of the optical elements have only two surfaces, both of which intersect each other to form a ridge and both of which intersect the substrate or another optical element.

26. The film of claim 25 wherein the ridges of at least some of the optical elements have ends that intersect the substrate or other optical elements where the ridges end.

27. The film of claim 1 in combination with a backlight including a panel surface having a light ray output distribution that varies at different locations on the panel surface, wherein the light redirecting film is in close proximity to the panel surface, and wherein the backlight includes at least one cold cathode fluorescent light source and at least one input edge that receives light from the light source, and the optical elements are arranged in a pattern that is tailored to redistribute the light ray output distribution of the backlight that receives light from the cold cathode fluorescent light source toward a direction normal to the substrate.

28. The film and backlight of claim 27 wherein the backlight includes two or more cold cathode fluorescent light sources and two or more input edges that receive light from the light sources, and the optical elements are arranged in a pattern that is tailored to redistribute the light ray output distribution of the backlight that receives light from the two or more cold cathode fluorescent light sources toward a direction normal to the substrate.

29. The film of claim 1 in combination with a backlight including a panel surface having a light ray output distribution that varies at different locations on the panel surface, wherein the light redirecting film is in close proximity to the panel surface, and wherein the backlight includes a single focused light source, and the optical elements are arranged in a radial type pattern that is tailored to redistribute the light ray output distribution of the backlight that is lighted by the single focused light source.

30. The film and backlight of claim 29 wherein the light source is a light emitting diode.

31. The film of claim 1 in combination with a backlight including a panel surface having a light ray output distribution that varies at different locations on the panel surface, wherein the light redirecting film is in close proximity to the panel surface, and wherein the backlight includes a single light emitting diode light source and an input edge that receives light from the light source, and the optical elements are arranged in a pattern that is tailored to redistribute the light ray output distribution of the backlight that receives light from the light source.

32. The film and backlight of claim 31 wherein the backlight includes a plurality of light emitting diode light sources and at least one input edge that receives light from the light sources, and the optical elements are arranged in a pattern that is tailored to redistribute the light ray output distribution of the backlight that receives light from the plurality of light sources.

33. The film and backlight of claim 32 wherein the light emitting diode light sources are different colored light sources that produce different colors of light that are mixed to provide a substantially white light output distribution.

34. The film and backlight of claim 32 wherein the backlight includes two or more input edges that receive light from two or more of the light emitting diode light sources.

35. A light redirecting film comprising a thin optically transparent substrate having a pattern of individual optical elements of well defined shape on or in the substrate, the optical elements being quite small in relation to a width and length of the substrate, at least some of the optical elements varying at different locations on the substrate to redistribute light passing through the substrate toward a direction normal to the substrate, wherein at least some of the optical elements have a pair of oppositely angled sides and a pair of oppositely curved ends.

36. The film of claim 35 wherein the oppositely angled sides intersect each other.

37. The film of claim 35 wherein at least some of the optical elements have a curved top surface intersecting the oppositely angled sides and oppositely curved ends.

38. The film of claim 35 in combination with a light source, wherein one side of the light redirecting film substrate is in close proximity to the light source with an air gap therebetween, and wherein at least some light that is emitted by the light source passes through the one side of the substrate and out an opposite side of the substrate to redistribute the light toward a direction normal to the substrate.

39. A light redirecting film comprising a thin optically transparent substrate having a pattern of individual optical elements of well defined shape on or in the substrate, the optical elements being quite small in relation to a width and length of the substrate, at least some of the optical elements varying at different locations on the substrate to redistribute light passing through the substrate toward a direction normal to the substrate, wherein the substrate has a coating to produce a specific effect and the coating has a different index of refraction than the substrate.

40. The film of claim 39 in combination with a light source, wherein one side of the light redirecting film substrate is in close proximity to the light source with an air gap therebetween, and wherein at least some light that is emitted by the light source passes through the one side of the substrate and out an opposite side of the substrate to redistribute the light toward a direction normal to the substrate.

41. A light redirecting film comprising a thin optically transparent substrate having a pattern of individual optical elements of well defined shape on or in the substrate, the optical elements being quite small in relation to a width and length of the substrate, at least some of the optical elements varying at different locations on the substrate to redistribute light passing through the substrate toward a direction normal to the substrate, wherein at least some of the optical elements have different slope angles.

42. The film of claim 41 in combination with a light source, wherein one side of the light redirecting film substrate is in close proximity to the light source with an air gap therebetween, and wherein at least some light that is emitted by the light source passes through the one side of the substrate and out an opposite side of the substrate to redistribute the light toward a direction normal to the substrate.