Waveguide and method of smoothing optical surfaces
View Patent ↗Disclosed is a waveguide having a light inlet surface and a viewing surface comprising stacked core layers separated by clad layers to form channels and bearing a smoothing layer on at least one of the light inlet surface or the viewing surface thereof.
1. A waveguide having a light inlet surface and a viewing surface comprising stacked core layers separated by clad layers to form channels and bearing a smoothing layer on at least one of the light inlet surface or the viewing surface thereof.
2. The waveguide of claim 1 wherein said smoothing layer comprises epoxy.
3. The waveguide of claim 2 wherein said epoxy is essentially fully crosslinked.
4. The waveguide of claim 1 wherein said smoothing layer further comprises material to modify its refractive index.
5. The waveguide of claim 4 wherein said material comprises at least one material selected from the group consisting of fluorinated polymer and transparent inorganic particles.
6. The waveguide of claim 1 wherein said surface bearing a smoothing layer is a light inlet surface.
7. The waveguide of claim 6 wherein said light inlet smoothing layer further provides adhesion to a light directing film.
8. The waveguide of claim 1 wherein said smoothing layer comprises a radiation curable compound.
9. The waveguide of claim 1 wherein said surface bearing a smoothing layer has a surface roughness of less than 1 Ra.
10. The waveguide of claim 1 wherein said surface bearing a smoothing layer has a roughness of between 0.001 and 0.5 Ra.
11. The waveguide of claim 1 wherein said inlet smoothing layer has a thickness of less than 200 micrometers.
12. The waveguide of claim 1 wherein said waveguide has a luminous flux of between 70 and 99%.
13. The waveguide of claim 1 wherein said smoothing layer further provides adhesion to a light directing film.
14. The waveguide of claim 1 wherein said surface bearing a smoothing layer is a light viewing surface.
15. The waveguide of claim 1 wherein said smoothing layer has a refractive index that is within ±0.1 different from the refractive index of the core layer.
16. The waveguide of claim 1 wherein said smoothing layer comprises at least one material selected from the group consisting of epoxy and a radiation curable polymer.
17. The waveguide of claim 1 wherein said core layers comprise one material selected from the group consisting of polyolefin, polyester, polycarbonate, polyamide, polymethylmethacrylate, and their copolymer derivatives and glass.
18. The waveguide of claim 1 wherein said core layers comprise a polycarbonate polymer or copolymer.
19. The waveguide of claim 1 wherein said core layers comprise a polymethlymethacrylate compound.
20. The waveguide of claim 1 wherein said core layers comprise a glass.
21. The waveguide of claim 1 wherein said core layers have a gradient refractive index.
22. The waveguide of claim 1 wherein said clad layers are opaque.
23. The waveguide of claim 1 that is a planar waveguide.
24. The waveguide of claim 1 that is a fiber waveguide.
25. A display screen comprising the wavequide of claim 1 .