Optical film having a structured surface with concave pyramid-shaped structures

• US 20060146566A1
• Filed: 12/30/2004
• Published: 07/06/2006
• Est. Priority Date: 12/30/2004
• Status: Active Grant

• Current Assignee: Byung-Soo Ko, Dongwon Chae, Leland R. Whitney, Mark E. Gardiner
• Original Assignee: Byung-Soo Ko, Dongwon Chae, Leland R. Whitney, Mark E. Gardiner
• Inventors: Gardiner, Mark E., Ko, Byung-Soo, Whitney, Leland R., Chae, Dongwon
• Granted Patent: US 7,320,538 B2
• Time in Patent Office: Days
• US Class Current: 362/611
• CPC Class Codes: G02B 5/045 Prism arrays
• CPC Class Codes: G02B 6/0036 2-D arrangement of prisms, protrusions, indentations or roughened surfaces
• CPC Class Codes: G02F 1/133607 the light controlling member including light directing or refracting elements, e.g. prisms or lenses

Abstract

Optical films are disclosed, which have a structured surface comprising a plurality of concave pyramid-shaped structures, each structure having a base including at least two first sides and at least two second sides. In addition, optical devices are disclosed that incorporate the optical films, for example, such that a first surface of the optical film is disposed to receive light from a light source and the structured surface faces away from the light source.

Claims

1. An optical device comprising:

a light source and an optical film having a first surface disposed to receive light from the light source and a structured surface facing away from the light source, the structured surface comprising a plurality of concave pyramid-shaped structures, each structure having a base including at least two first sides and at least two second sides.

2. The optical device as recited in claim 1, wherein the two first sides are disposed opposite to each other along a first general direction and the two second sides are disposed opposite to each other along a second general direction,

wherein the optical film transmits a substantial portion of light incident thereon along the first general direction when an angle of incidence is within a first angle with respect to an axis disposed at an angle to the first surface and reflects a substantial portion of light when the angle of incidence is outside the first angle and

wherein the optical film transmits a substantial portion of light incident thereon along the second general direction when an angle of incidence is within a second angle with respect to the axis and reflects a substantial portion of light when the angle of incidence is outside the second angle.

3. The optical device as recited in claim 2, wherein the axis is generally orthogonal to the first surface.

4. The optical device according to claim 2, wherein the first angle is different from the second angle.

5. The optical device according to claim 1, wherein the base has a generally rectangular or a generally square shape.

6. The optical device according to claim 1, wherein each of the plurality of concave pyramid-shaped structures is further characterized by an apex angle that lies within a range of about 60 degrees to about 120 degrees.

7. The optical device according to claim 1, wherein each concave pyramid-shaped structure is arranged in a substantial contact with at least one other concave pyramid-shaped structure.

8. The optical device according to claim 1, wherein the bases of the plurality of concave pyramid-shaped structures are disposed so that at least one of the first and second sides are substantially parallel to one another.

9. The optical device according to claim 1, wherein the optical film further comprises a substrate portion disposed between the light source and the structured surface, the substrate portion having an additional optical characteristic different from an optical characteristic of the structured surface.

10. The optical device according to claim 9, wherein the substrate portion comprises at least one of:

a polarizer, a diffuser, a brightness enhancing film, a turning film and any combination thereof.

11. The optical device according to claim 1, wherein each of the plurality of concave pyramid-shaped structures comprises at least four surfaces and at least two of the at least four surfaces meet.

12. The optical device according to claim 1, wherein each of the plurality of concave pyramid-shaped structures comprises five surfaces, four surfaces being attached to the base and a fifth surface being adjacent to the four surfaces.

13. The optical device according to claim 1, further comprising a light valve arrangement disposed to receive light transmitted through the optical film.

14. The optical device according to claim 1, further comprising a lightguide optically connected to the light source and disposed between the light source and the optical film.

15. An optical film having a first surface and a structured surface, the structured surface comprising a plurality of concave pyramid-shaped structures, each structure having a base including at least two first sides and at least two second sides;

wherein at least one of the first and second sides of at least one concave pyramid-shaped structures is offset with respect to at least one of the first and second sides of at least one other concave pyramid-shaped structure.

16. The optical film according to claim 15, wherein the base has a generally rectangular or a generally square shape.

17. The optical film according to claim 15, wherein the optical film further comprises a substrate portion disposed between the light source and the structured surface, the substrate portion having an additional optical characteristic different from an optical characteristic of the structured surface.

18. The optical film according to claim 15, wherein each of the plurality of concave pyramid-shaped structures comprises five surfaces, four surfaces being attached to the base and a fifth surface being adjacent to the four surfaces.

19. An optical film having a first surface and a structured surface, the structured surface comprising a plurality of concave pyramid-shaped structures, each structure having a base including at least two first sides disposed opposite to each other along a first direction and at least two second sides disposed opposite to each other along a second general direction;

wherein at least one of the first and second directions of at least one concave pyramid-shaped structure is different from the respective direction of at least one other concave pyramid-shaped structure.

20. The optical film according to claim 19, wherein the base has a generally rectangular or a generally square shape.

21. The optical film according to claim 19, wherein the optical film further comprises a substrate portion disposed between the light source and the structured surface, the substrate portion having an additional optical characteristic different from an optical characteristic of the structured surface.

22. The optical film according to claim 19, wherein each of the plurality of concave pyramid-shaped structures comprises five surfaces, four surfaces being attached to the base and a fifth surface being adjacent to the four surfaces.