Subwavelength optical microstructure light-redirecting films

• US 20040027676A1
• Filed: 05/23/2003
• Published: 02/12/2004
• Est. Priority Date: 11/12/1999
• Status: Active Grant

• Current Assignee: Orafol Americas Inc. (Orafol Europe GmbH)
• Original Assignee: Reflexite
• Inventors: Mullen, Patrick W., Nilsen, Robert B., Lu, Xiao-Jing
• Granted Patent: US 6,891,677 B2
• Time in Patent Office: Days
• US Class Current: 359/619
• CPC Class Codes: G02B 1/11 Anti-reflection coatings
• CPC Class Codes: G02B 1/118 having sub-optical wavelength surface structures designed to provide an enhanced transmittance, e.g. moth-eye structures
• CPC Class Codes: G02B 5/045 Prism arrays
• CPC Class Codes: G02B 5/124 plural reflecting elements forming part of a unitary plate or sheet
• CPC Class Codes: G02B 6/0036 2-D arrangement of prisms, protrusions, indentations or roughened surfaces
• CPC Class Codes: G02B 6/0053 Prismatic sheet or layer; Brightness enhancement element, sheet or layer
• CPC Class Codes: G03B 21/62 Translucent screens

Abstract

A waveguide for use in a back lighting device includes a moth-eye structured surface. A back lighting system includes a lighting device, a display panel, and a waveguide for redirecting light generated by the light source toward the display panel. A first light-redirecting film, which can include a plurality of moth-eye structures, can be positioned between the waveguide and the display panel. The first light-redirecting film can also include a plurality of linear prisms. A second light-redirecting film is also provided that can include a plurality of moth-eye structures and a plurality of linear prisms. The second light-redirecting film can be positioned between the first light-redirecting film and the display panel. A diffuser can be positioned between the first light-redirecting film and the waveguide and/or between the second light-redirecting film and the display panel.

Claims

1. A waveguide for use in a back lighting display device, the waveguide having a moth-eye structured surface thereon.

2. The waveguide of claim 1, wherein the waveguide is wedge-shaped.

3. The waveguide of claim 1, wherein the waveguide is configured to be implemented in a back lighting system.

4. A back lighting system, comprising;

a lighting device;

a display panel; and

a waveguide for redirecting light generated by the lighting device toward the display panel, the waveguide including a plurality of moth-eye structures on at least one surface thereof.

5. The back lighting system of claim 4, further comprising a first light-redirecting film positioned between the waveguide and the display panel.

6. The back lighting system of claim 5, wherein the first light-redirecting film includes a plurality of moth-eye structures on a first side of the first light-redirecting film.

7. The back lighting system of claim 6, wherein the moth-eye structures face the waveguide.

8. The back lighting system of claim 6, wherein the moth-eye structures face the display panel.

9. The back lighting system of claim 6, wherein the first light-redirecting film includes a plurality of linear prisms on a second side of the first light-redirecting film, the linear prisms facing the display panel.

10. The back lighting system of claim 5, further comprising a second light-redirecting film positioned between the first light-redirecting film and the display panel.

11. The back lighting system of claim 10, further comprising a diffuser positioned between the second light-redirecting film and the display panel.

12. The back lighting system of claim 10, wherein the second light-redirecting film includes a plurality of moth-eye structures on a first side of the second light-redirecting film, the moth-eye structures facing the first light-redirecting film.

13. The back lighting system of claim 12, wherein the second light-redirecting film includes a plurality of linear prisms on a second side of the second light-redirecting film, the linear prisms facing the display device.

14. The back lighting system of claim 5, further comprising a diffuser positioned between the first light-redirecting film and the waveguide.

15. The back lighting system of claim 5, further comprising a diffuser positioned between the first light-redirecting film and the display panel.

16. The back lighting system of claim 4, further comprising a reflector for redirecting light toward the waveguide.

17. A light-redirecting film comprising a sheeting having a plurality of prisms on a first side of the film, and a plurality of moth-eye structures on a second side of the film.

18. The light-redirecting film of claim 17, wherein the prisms include linear prisms.

19. The light-redirecting film of claim 18, wherein the moth-eye structures include linear moth-eye structures.

20. An optical structure, comprising:

a) a first light-redirecting film having a first surface with a plurality of linear moth-eye structures thereon and a second surface with first linear prisms having peaks; and

b) a second light-redirecting film having a first surface with a plurality of linear moth-eye structures thereon and a second surface with second linear prisms having peaks.

21. The optical structure of claim 20, further comprising an abrasion reduction layer positioned between the first and second light-redirecting films.

22. The optical structure of claim 20, further comprising a waveguide positioned adjacent to the first light-redirecting film, the waveguide including a moth-eye structured surface.

23. The optical structure of claim 22, further comprising a diffuser positioned between the first light-redirecting film and the waveguide.

24. The optical structure of claim 20, wherein the linear moth-eye structures of the first light-redirecting film are oriented at about ninety degrees relative to the peaks of the first linear prisms.

25. The optical structure of claim 20, wherein the linear moth-eye structures of the second light-redirecting film are oriented at about ninety degrees relative to the peaks of the second linear prisms.

26. The optical structure of claim 20, further comprising a diffuser positioned between the second light-redirecting layer and the display panel.

27. The optical structure of claim 20, wherein the linear moth-eye structures of the second film are substantially parallel to the peaks of the linear prisms of the first film.

28. The optical structure of claim 20, wherein the linear moth-eye structures of the second film are substantially perpendicular to the peaks of the linear prisms of the first film.

29. The optical structure of claim 20, wherein the linear moth-eye structures of the first light-redirecting film are substantially parallel to the peaks of the first linear prisms.

30. The optical structure of claim 20, wherein the linear moth-eye structures of the second light-redirecting film are substantially parallel to the peaks of the second linear prisms.

31. The optical structure of claim 20, wherein the peaks of the first linear prisms are substantially perpendicular to the peaks of the second linear prisms.

32. The optical structure of claim 20, wherein the linear moth-eye structures have a pitch between about 150 and 350 nanometers.

33. An optical structure, comprising:

a) a first light-redirecting film having a plurality of linear prisms on one side and a moth-eye structured surface on an opposing side; and

b) a second light-redirecting film having a plurality of linear prisms on one side and a moth-eye structured surface on an opposing side.

34. The optical structure of claim 33, wherein the moth-eye structured surface of the first and second films includes linear moth-eye structures, the moth-eye structures of the first film being about perpendicular to the linear prisms of the first film and the moth-eye structures of the second film being about perpendicular to the linear prisms of the second film.

35. The optical structure of claim 33, wherein the moth-eye structured surface of the first and second films includes linear moth-eye structures, the moth-eye structures of the first film being about parallel to the linear prisms of the first film and the moth-eye structures of the second film being about perpendicular to the linear prisms of the second film.

36. The optical structure of claim 33, wherein the moth-eye structured surface of the first and second films includes linear moth-eye structures, the moth-eye structures of the first film being about perpendicular to the linear prisms of the first film and the moth-eye structures of the second film being about parallel to the linear prisms of the second film.

37. The optical structure of claim 33, wherein the moth-eye structured surface of the first and second films includes linear moth-eye structures, the moth-eye structures of the first film being about parallel to the linear prisms of the first film and the moth-eye structures of the second film being about parallel to the linear prisms of the second film.