Light redirecting films and film systems

• US 20040114346A1
• Filed: 12/05/2003
• Published: 06/17/2004
• Est. Priority Date: 02/23/1999
• Status: Active Grant

• Current Assignee: Rambus Delaware LLC (Rambus Inc.)
• Original Assignee: Jeffery R. Parker, Robert M. Ezell, Timothy A. Mccollum
• Inventors: McCollum, Timothy A., Parker, Jeffery R., Ezell, Robert M.
• Granted Patent: US 7,090,389 B2
• Time in Patent Office: Days
• US Class Current: 362/31
• 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 include a pattern of individual optical elements of well defined shape on the light exit surface of the films for refracting the light entering the entrance surface of the films from a backlight toward a direction normal to the exit surface. The individual optical elements overlap and intersect each other. Also, the orientation, size and/or shape of the optical elements may be tailored to redirect more of the incident light from the backlight within a desired viewing angle.

Claims

1. A method of selecting a light redirecting film for a particular application comprising the steps of providing a length of film having a pattern of optical elements on or in the film that varies, selecting an area of the pattern that best suits a particular application, and removing the selected area from the film to provide the light redirecting film.

2. The method of claim 1 wherein the pattern varies along the length of the film.

3. The method of claim 1 wherein the pattern varies along the width of the film.

4. The method of claim 1 wherein the pattern varies along the length and width of the film.

5. The pattern of claim 1 wherein the length of the film comprises a roll of the film from which the selected area is removed.

6. The method of claim 1 wherein the selected area is die cut from the length of the film.

7. The method of claim 1 wherein the pattern is a repeating pattern on the film.

8. The method of claim 7 wherein the length of the film comprises a roll of the film from which the selected area is removed.

9. The method of claim 8 wherein the selected area is die cut from the roll of the film.

10. A method of selecting a light redirecting film for a particular application comprising the steps of providing a length of film having a pattern of individual optical elements of well defined shape on or in the film that varies, the optical elements being quite small in relation to a width and length of the film, selecting an area of the film that has a pattern of the optical elements that best suits a particular application, and removing the selected area from the film to provide the light redirecting film.

11. The method of claim 10 wherein the pattern is a repeating pattern.

12. The method of claim 10 wherein the pattern varies at different locations on the film.

13. The method of claim 10 wherein at least some of the optical elements overlap, intersect or interlock each other.

14. The method of claim 10 wherein at least some of the optical elements have different shapes.

15. The method of claim 10 wherein at least some of the optical elements have a different beam profile at different locations on the film.

16. The method of claim 10 wherein at least some of the optical elements are randomly distributed on the film.

17. The method of claim 10 wherein at least some of the optical elements are oriented at different angles on the film.

18. The method of claim 10 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.

19. The method of claim 10 wherein at least some of the optical elements are arranged in groupings across the film, with at least some of the optical elements in at least some of the groupings having a different size or shape characteristic that collectively produce an average size or shape characteristic for each of the groupings that varies across the film.

20. A method of selecting an optical panel for a particular application comprising the steps of providing a length of substrate having a pattern of optical elements on or in the substrate that varies, selecting an area of the pattern that best suits a particular application, and removing the selected area from the substrate to provide the optical panel.

21. The method of claim 20 wherein the pattern varies along the length of the substrate.

22. The method of claim 20 wherein the pattern varies along the width of the substrate.

23. The method of claim 20 wherein the pattern varies along the length and width of the substrate.

24. The pattern of claim 20 wherein the length of the substrate comprises a roll of the substrate from which the selected area is removed.

25. The method of claim 20 wherein the selected area is die cut from the length of the substrate.

26. The method of claim 20 wherein the pattern is a repeating pattern on the substrate.

27. The method of claim 26 wherein the length of the substrate comprises a roll of the substrate from which the selected area is removed.

28. The method of claim 27 wherein the selected area is die cut from the roll of the substrate.

29. The method of claim 20 wherein the optical panel is a backlight.

30. A method of selecting an optical panel for a particular application comprising the steps of providing a length of substrate having a pattern of individual optical elements of well defined shape on or in the substrate that varies, the optical elements being quite small in relation to a width and length of the substrate, selecting an area of the substrate that has a pattern of the optical elements that best suits a particular application, and removing the selected area from the substrate to provide the optical panel.

31. The method of claim 30 wherein the pattern is a repeating pattern.

32. The method of claim 30 wherein the pattern varies at different locations on the substrate.

33. The method of claim 30 wherein at least some of the optical elements have different shapes.

34. The method of claim 30 wherein at least some of the optical elements have a different beam profile at different locations on the film.

35. The method of claim 30 wherein at least some of the optical elements are randomly distributed on the film.

36. The method of claim 30 wherein at least some of the optical elements are oriented at different angles on the film.

37. The method of claim 30 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.