Light diffuser with colored variable diffusion
View Patent ↗The invention provides a light diffuser comprising a macro diffusion efficiency variation wherein at least part of the diffuser is colored. The invention also provides light diffuser comprising a macro diffusion efficiency variation wherein at least part of the diffuser is colored for rear projection displays, back-lighted imaging media, and a liquid crystal display component and device. The invention further provides a process for preparing such a diffuser.
1. A light diffuser polymeric film comprising a macro diffusion efficiency variation of greater than 5% over an in plane distance of at least 2 cm using an integrating sphere with a light entry port of 25.4 mm diameter, the diffuser having a total light transmission of at least 80% and wherein at least part of the diffuser is selectively colored.
2. The light diffuser of claim 1 wherein said color has a density of greater than 0.2.
3. The light diffuser of claim 1 wherein specular areas of said macro diffusion efficiency variation are colored.
4. The light diffuser of claim 1 wherein diffuse areas of said macro diffusion efficiency variation are colored.
5. The light diffuser of claim 1 wherein gradient areas of said macro diffusion efficiency variation are colored.
6. The light diffuser of claim 1 wherein said colored part of the diffuser comprises dye based colorants.
7. The light diffuser of claim 1 wherein said colored part of the diffuser comprises pigment based colorants.
8. The light diffuser of claim 1 wherein said colored part of the diffuser comprises fluorescent materials.
9. The light diffuser of claim 1 wherein said part of the diffuser corresponds to color wavelength band of from 10 to 70 nm.
10. The light diffuser of claim 1 wherein said colored part of the diffuser comprises text.
11. The light diffuser of claim 1 wherein said colored part of the diffuser comprises graphics.
12. The light diffuser of claim 1 wherein said colored part of the diffuser comprise an image.
13. The light diffuser of claim 1 wherein said part of the diffuser comprises chromatic transmission.
14. The light diffuser of claim 13 wherein the chromatic transmission comprises yellow light at 570 to 620 nm.
15. The light diffuser of claim 13 wherein the chromatic transmission comprises magenta light at 630 to 690 and 425 to 480 nm.
16. The light diffuser of claim 13 wherein the chromatic transmission comprises cyan light at 480 to 520 nm.
17. The light diffuser of claim 13 wherein the chromatic transmission comprises red light at 630 to 690 nm.
18. The light diffuser of claim 13 wherein the chromatic transmission comprises green light at 525 to 590 nm.
19. The light diffuser of claim 13 wherein the chromatic transmission comprises blue light at 425 to 480 nm.
20. The light diffuser of claim 1 wherein the diffusion efficiency varies more than 50 percent in two different locations of the diffuser.
21. The light diffuser of claim 1 wherein the diffusion efficiency variation comprises a gradient.
22. The light diffuser of claim 1 that is rectangular in shape wherein there is diffusion efficiency variation along a diagonal of the rectangle.
23. The light diffuser of claim 1 that is rectangular in shape wherein there is diffusion efficiency variation along the width or height.
24. The light diffuser of claim 1 wherein there is diffusion efficiency variation from the center to the perimeter.
25. The light diffuser of claim 1 wherein there is diffusion efficiency variation along the perimeter.
26. The light diffuser of claim 1 wherein the diffusion efficiency variation is such that iso-efficiency exhibits an elliptical pattern.
27. The light diffuser of claim 1 wherein the diffusion efficiency variation comprises a repeating pattern.
28. The light diffuser of claim 1 wherein the diffusion efficiency variation comprises a specular component.
29. The light diffuser of claim 1 wherein the diffusion efficiency variation provides values is at least 10% less on the edges than in the center of said light diffuser.
30. The light diffuser of claim 1 further comprising a base and a plurality of convex or concave complex lenses of the surface of said base.
31. The plurality of complex lenses of claim 30 wherein the said convex or concave complex lenses are randomly distributed on the surface of the base.
32. The plurality of complex lenses of claim 30 wherein said concave or convex complex lenses have an average width in the x and y direction of 3 to 60 microns.
33. The plurality of complex lenses of claim 30 wherein said concave or convex complex lenses have a height/diameter ratio of 0.03 to 1.0.
34. The light diffuser of claim 1 further comprising a microvoided polymer sheet.
35. The light diffuser of claim 34 wherein the microvoided polymer sheet comprises substantially circular voids.
36. The light diffuser of claim 1 wherein said light diffuser comprises a surface diffuser.
37. The light diffuser of claim 1 wherein said light diffuser comprises a bulk diffuser.
38. The light diffuser of claim 1 wherein said light diffuser comprises a base comprising a surface microstructure.