Turning film using array of roof prism structures

• US 20060072203A1
• Filed: 10/01/2004
• Published: 04/06/2006
• Est. Priority Date: 10/01/2004
• Status: Active Grant

• Current Assignee: SKC Hi-Tech & Marketing Co., Ltd.
• Original Assignee: Eastman Kodak Company
• Inventors: Lee, Junwon
• Granted Patent: US 7,775,700 B2
• Time in Patent Office: Days
• US Class Current: 359/625
• CPC Class Codes: G02B 5/045 Prism arrays
• CPC Class Codes: G02B 6/0053 Prismatic sheet or layer; Brightness enhancement element, sheet or layer

Abstract

The invention generally relates to an optical turning film for providing light redirection, comprising: (a) an input surface for accepting incident light comprising a a plurality of roof prism structures arranged in a two-dimensional array; and, (b) a substantially planar output surface.

Claims

1. An optical turning film for providing light redirection, comprising:

(a) an input surface for accepting incident light comprising a plurality of roof prism structures arranged in a two-dimensional array; and

,

(b) a substantially planar output surface.

2. An optical turning film according to claim 1 wherein, relative to a normal to the output surface of the turning film, roof prism facets for the roof prism structures are inclined at an angle between 25 and 60 degrees.

3. An optical turning film according to claim 1 wherein said, relative to a normal to the output surface of the turning film, roof prism facets for the roof prism structures are inclined at an angle between 35 and 45 degrees.

4. An optical turning film according to claim 1 wherein roof prism facets for each of the roof prism structures intersect at an angle between 50 and 100 degrees.

5. An optical turning film according to claim 1 wherein roof prism facets for each of the roof prism structures intersect at an angle between 60 and 80 degrees.

6. An optical turning film according to claim 1 fabricated from any of a group of materials including polyolefins, polyesters, polyamides, polycarbonates, cellulosic esters, polystyrene, polyvinyl resins, polysulfonamides, polyethers, polyimides, polyvinylidene fluoride, polyurethanes, polyphenylenesulfides, polytetrafluoroethylene, polyacetals, polysulfonates, polyester ionomers, polyolefin ionomers, copolymers, and polymer mixtures.

7. An optical turning film for providing light collimation along a first direction and light redirection in a second direction substantially orthogonal to the first direction, the optical turning film comprising a plurality of roof prism structures arranged in a two-dimensional array, wherein each roof prism structure comprises:

(i) an output facet substantially coplanar with the output surface of the turning film;

(ii) an input facet for accepting incident light, the input facet substantially orthogonal to the output facet;

(iii) roof facets meeting at a ridge, the roof facets intersecting at a peak angle in the range from about 60 to about 80 degrees;

wherein the roof facets are inclined, relative to a normal to the output facet, at a ridge angle between about 25 and 60 degrees from normal.

8. An optical turning film according to claim 7 wherein the roof facets are inclined, relative to a normal to the output facet, at a ridge angle between about 35 and 45 degrees from normal.

9. An optical turning film according to claim 7 fabricated from any of a group of materials including polyolefins, polyesters, polyamides, polycarbonates, cellulosic esters, polystyrene, polyvinyl resins, polysulfonamides, polyethers, polyimides, polyvinylidene fluoride, polyurethanes, polyphenylenesulfides, polytetrafluoroethylene, polyacetals, polysulfonates, polyester ionomers, polyolefin ionomers, copolymers, and polymer mixtures.

10. An illumination system for providing light from a surface comprising:

(a) a light source;

(b) a light guiding plate comprising;

(i) an input edge for accepting incident light from the light source;

(ii) an output surface for providing redirected light;

(iii) a reflecting surface for directing light incident thereon toward the

output surface as redirected light;

(c) a turning film optically coupled with the output surface of the light guiding plate, the turning film comprising a plurality of roof prism structures arranged in a two-dimensional array.

11. An illumination system according to claim 10 wherein, relative to a normal to the output surface of the turning film, roof prism facets for the roof prism structures are inclined at an angle between 25 and 60 degrees.

12. An illumination system according to claim 10 wherein said, relative to a normal to the output surface of the turning film, roof prism facets for the roof prism structures are inclined at an angle between 35 and 45 degrees.

13. The illumination system of claim 10 wherein roof prism facets for each of the roof prism structures intersect at an angle between 60 and 80 degrees.

14. The illumination system of claim 10 wherein said turning film is fabricated from any of a group of materials including polyolefins, polyesters, polyamides, polycarbonates, cellulosic esters, polystyrene, polyvinyl resins, polysulfonamides, polyethers, polyimides, polyvinylidene fluoride, polyurethanes, polyphenylenesulfides, polytetrafluoroethylene, polyacetals, polysulfonates, polyester ionomers, polyolefin ionomers, copolymers, and polymer mixtures.

16. A display apparatus according to claim 11 wherein the display device comprises a liquid crystal display.

15. A display apparatus comprising:

(a) a display device for forming an image;

(b) an illumination system for providing light to the display device comprising;

(i) a light source;

(ii) a light guiding plate comprising;

(1) an input edge for accepting incident light from the light source;

(2) an output surface for providing redirected light;

(3) a reflecting surface for directing light incident thereon toward the output surface as redirected light;

(iii) a turning film optically coupled with the output surface of the light guiding plate, the input surface of the turning film comprising a plurality of roof prism structures arranged in a two-dimensional array.

17. The display apparatus according to claim 15 wherein, relative to a normal to the output surface of the turning film, roof prism facets for the roof prism structures are inclined at an angle between 25 and 60 degrees.

18. The display apparatus according to claim 15 wherein said, relative to a normal to the output surface of the turning film, roof prism facets for the roof prism structures are inclined at an angle between 35 and 45 degrees.

19. The display apparatus of claim 15 wherein roof prism facets for each of the roof prism structures intersect at an angle between 60 and 80 degrees.

20. The display apparatus of claim 15 wherein said turning film fabricated from any of a group of materials including polyolefins, polyesters, polyamides, polycarbonates, cellulosic esters, polystyrene, polyvinyl resins, polysulfonamides, polyethers, polyimides, polyvinylidene fluoride, polyurethanes, polyphenylenesulfides, polytetrafluoroethylene, polyacetals, polysulfonates, polyester ionomers, polyolefin ionomers, copolymers, and polymer mixtures.

can be used.