Light management films of differing refractive indices

• US 20060269214A1
• Filed: 08/09/2006
• Published: 11/30/2006
• Est. Priority Date: 02/11/2005
• Status: Abandoned Application

• Current Assignee: Rohm and Haas Denmark Finance A/S
• Original Assignee: Rohm and Haas Denmark Finance A/S
• Inventors: Sudol, Ronald J.
• Application Number:
  US11/501,398
• Publication Number:
  US 20060269214A1
• Time in Patent Office: Days
• US Class Current: 385/146
• CPC Class Codes: G02B 5/045 Prism arrays
• CPC Class Codes: G02F 1/133507 Films for enhancing the luminance
• CPC Class Codes: G02F 1/133606 including a specially adapted diffusing, scattering or light controlling members
• CPC Class Codes: G02F 1/133607 the light controlling member including light directing or refracting elements, e.g. prisms or lenses

Abstract

An optical layer includes a first light management film having a first index of refraction (n₁) and a second light management film having a second index of refraction (n₂). The first index of refraction and the second index of refraction are not the same, and a plurality of optical features is disposed over each of the light management films. A light management film is also disclosed.

Claims

1. An optical layer, comprising:

a first light management film having a first index of refraction (n₁);

a second light management film having a second index of refraction (n₂), wherein the first index of refraction and the second index of refraction are not the same; and

a plurality of optical features disposed over each of the light management films.

2. The optical layer of claim 1, wherein both the first and second light management films each include a plurality of optical features.

3. The optical layer of claim 2, wherein the first film includes a first side and the second film includes a second side, and optical features are disposed over the first and second sides.

4. The optical layer of claim 2, wherein the optical features include prism-shaped features.

5. The optical layer of claim 2, wherein the optical features include wedge-shaped features.

6. The optical layer of claim 5, wherein the wedge-shaped features comprise at least one curved surface.

7. The optical layer of claim 1, wherein the first index of refraction is greater than the second index of refraction.

8. The optical layer of claim 1, wherein the second index of refraction is greater than the first index of refraction.

9. The optical layer of claim 1, wherein the first light management film, or the second light management film, or both are a nanocomposite material.

10. The optical layer of claim 1, wherein (n₁.×

n₂)^1/2 is less than or equal to 1.796.

11. The optical layer of claim 1, wherein (n₁.×

n₂)^1/2 is greater than 1.796.

12. An optical layer as recited in claim 2, wherein the first light management film includes first ridges and the second light management film includes second ridges;

the optical features of the first film are substantially parallel to the first ridges and the optical features of the second film are substantially parallel to the second ridges; and

the first ridges are substantially parallel to the second ridges.

13. An optical layer as recited in claim 2, wherein the first light management film includes first ridges and the second light management film includes second ridges;

the optical features of the first film are substantially parallel to the first ridges and the optical features of the second film are substantially parallel to the second ridges; and

the first ridges are substantially perpendicular to the second ridges.

14. An optical layer as recited in claim 1, wherein (n₁.×

n₂)^1/2 is less than or equal to approximately 1.635.

15. A display device, comprising:

a light management layer including;

a first light management film having a first index of refraction (n₁);

a second light management film having a second index of refraction (n₂), wherein the first index of refraction and the second index of refraction are not the same; and

a plurality of optical features disposed over each of the light management films.

16. The display device of claim 15, wherein (n₁.×

n₂)^1/2 is greater than 1.796.

17. The display device of claim 15, further comprising one or more light sources.

18. The display device of claim 15, further comprising a light valve.

19. The display device of claim 18, wherein the light valve is one of:

a liquid crystal device (LCD);

a liquid crystal on silicon (LCOS) device;

or a digital light processing (DLP) light valve.

20. The display device of claim 15, wherein the first film includes a first side and the second film includes a second side, and optical features are disposed over the first and second sides.

21. The display device of claim 20, wherein the optical features are prism-shaped.

22. The display device of claim 20, wherein the optical features are wedge-shaped.

23. The display device of claim 20, wherein the first index of refraction is greater than the second index of refraction.

24. The display device of claim 20, wherein the second index of refraction is greater than the first index of refraction.

25. The display device of claim 15, wherein the display device is an edge-illuminated device.

26. The display device of claim 15, wherein the display device is a direct-illuminated device.

27. The display device of claim 17, further comprising a light guide disposed between the light source and the light management layer.

28. The display device of recited in claim 27, wherein the second index of refraction is greater than the first index of refraction and the second film is disposed between the first film and the light guide.

29. The display device of recited in claim 27, wherein the second index of refraction is less than the first index of refraction and the second film is disposed between the first film and the light guide.

30. The display device of claim 15, wherein (n₁.×

n₂)^1/2 is less than or equal to 1.796.

31. The display device of claim 15, wherein (n₁.×

n₂)^1/2 is less than approximately 1.635.

32. A display device as recited in claim 20, wherein the first light management film includes first ridges and the second light management film includes second ridges;

and the optical features of the first film are substantially parallel to the first ridges and the optical features of the second film are substantially parallel to the second ridges; and

the first ridges are substantially parallel to the second ridges.

33. A display device as recited in claim 20, wherein the first light management film includes first ridges and the second light management film includes second ridges;

and the optical features of the first film are substantially parallel to the first ridges and the optical features of the second film are substantially parallel to the second ridges; and

the first ridges are substantially perpendicular to the second ridges.

34. The display device of claim 20, wherein the plurality of features include features that are prism-shaped.

35. The display device of claim 20, wherein the plurality of features include features that are wedge-shaped.

36. An optical layer, comprising:

a first light management film having a first index of refraction (n₁);

a second light management film having a second index of refraction (n₂), wherein the first index of refraction and the second index of refraction are not the same; and

a plurality of optical features comprising wedge-shaped or prism-shaped features disposed over each of the light management films.

37. An optical layer as recited in claim 36, wherein the first light management film includes first ridges and the second light management film includes second ridges;

the optical features of the first film are substantially parallel to the first ridges and the optical features of the second film are substantially parallel to the second ridges; and

the first ridges are substantially parallel to the second ridges.

38. An optical layer as recited in claim 36, wherein the first light management film includes first ridges and the second light management film includes second ridges;

the optical features of the first film are substantially parallel to the first ridges and the optical features of the second film are substantially parallel to the second ridges; and

the first ridges are substantially perpendicular to the second ridges.

39. The optical layer of claim 36, wherein the light management films include optical features that vary in one or more of size, shape, orientation, and spacing, disposed on one or more surfaces of one or more of the light management films

40. The optical layer of claim 36, wherein the wedge-shaped features comprise at least one curved surface.

41. An optical layer, comprising:

a first light management film having a first index of refraction (n₁);

a second light management film having a second index of refraction (n₂), wherein the first index of refraction and the second index of refraction are not the same; and

a plurality of optical features comprising wedge-shaped and prism-shaped features disposed over each of the light management films.

42. An optical layer as recited in claim 41, wherein the first light management film includes first ridges and the second light management film includes second ridges;

the optical features of the first film are substantially parallel to the first ridges and the optical features of the second film are substantially parallel to the second ridges; and

the first ridges are substantially parallel to the second ridges.

43. An optical layer as recited in claim 41, wherein the first light management film includes first ridges and the second light management film includes second ridges;

the optical features of the first film are substantially parallel to the first ridges and the optical features of the second film are substantially parallel to the second ridges; and

the first ridges are substantially perpendicular to the second ridges.

44. The optical layer of claim 41, wherein the wedge-shaped features comprise at least one curved surface.

45. The optical layer of claim 41 wherein the light management films include optical features that vary in one or more of size, shape, orientation, and spacing, disposed on one or more surfaces of one or more of the light management films

46. A display device, comprising a light management layer including:

a first light management film having a first index of refraction (n₁);

a second light management film having a second index of refraction (n₂), wherein the first index of refraction and the second index of refraction are not the same; and

a plurality of optical features comprising wedge-shaped or prism-shaped features disposed over each of the light management films.

47. A display device, comprising:

a light management layer including;

a first light management film having a first index of refraction (n₁);

a second light management film having a second index of refraction (n₂), wherein the first index of refraction and the second index of refraction are not the same; and

a plurality of optical features comprising wedge-shaped and prism-shaped features disposed over each of the light management films.