OPTICAL SHEET AND METHOD FOR FABRICATING THE SAME

• US 20080137367A1
• Filed: 10/31/2007
• Published: 06/12/2008
• Est. Priority Date: 12/12/2006
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: KIM, Dong Hoon, CHOI, Jin Sung
• Granted Patent: US 8,158,040 B2
• Time in Patent Office: Days
• US Class Current: 362/607
• CPC Class Codes: B29C 33/3878 used as masters for making successive impressions
• CPC Class Codes: B29D 11/00278 Lenticular sheets B29D11/00269 takes precedence
• CPC Class Codes: B29L 2011/00 Optical elements, e.g. lenses, prisms
• CPC Class Codes: G02B 5/02 Diffusing elements; Afocal elements
• CPC Class Codes: G02B 6/0053 Prismatic sheet or layer; Brightness enhancement element, sheet or layer
• CPC Class Codes: G02B 6/0065 Manufacturing aspects; Material aspects

Abstract

An optical sheet and a method for fabricating the optical sheet, wherein a diffusion pattern is formed to diffuse and condense light. The optical sheet includes a prism pattern having a plurality of mountains and ravines to condense light generated from a light source and a plurality of diffusion patterns irregularly formed on the prism pattern to diffuse the light.

Claims

1. An optical sheet, comprising:

a prism pattern comprising a plurality of mountains and ravines to condense light generated from a light source; and

a plurality of diffusion patterns irregularly formed on the prism pattern to diffuse the light.

2. The optical sheet of claim 1, wherein the diffusion pattern has a concave or convex shape.

3. The optical sheet of claim 2, wherein the diffusion pattern has a curved surface or a polyhedral surface.

4. The optical sheet of claim 3, wherein a diffusion pattern has a different cross-sectional area size than an adjacent diffusion pattern.

5. The optical sheet of claim 4, wherein the mountains of the prism pattern have a pitch of about 20 □

m to 200 □

m.

6. The optical sheet of claim 5, wherein the mountains are uniformly formed in a straight line or a curved line.

7. The optical sheet of claim 6, wherein the mountains of the prism pattern are formed at irregular intervals.

8. The optical sheet of claim 7, wherein each mountain has a scalene triangular cross section in which two sides are different in length.

9. The optical sheet of claim 7, wherein a peak of each mountain is round.

10. A method for fabricating an optical sheet, comprising:

preparing a sub master by forming a prism pattern having a plurality of mountains and ravines in turn and forming irregular diffusion patterns on sides of the mountains;

preparing a main master having mountains, ravines, and irregular diffusion patterns corresponding to the mountains, ravines, and irregular diffusion patterns of the sub master; and

pressurizing a film using the main master to form an optical sheet.

11. The method of claim 10, wherein preparing the sub master comprises:

scattering beads on a substrate;

pressurizing the beads;

removing the beads from the substrate to form the irregular diffusion patterns; and

forming the prism pattern on the irregular diffusion pattern.

12. The method of claim 11, wherein forming the diffusion patterns comprises forming the diffusion patterns by uniformly scattering at least one of a concave form, a convex form, and a polyhedral form.

13. The method of claim 12, wherein forming the prism pattern comprises uniformly forming the plurality of mountains in one of a straight line and a curved line.

14. The method of claim 13, wherein forming the prism pattern comprises forming the mountains at irregular intervals.

15. The method of claim 14, wherein forming the prism pattern comprises forming each mountain with a round peak.

16. The method of claim 10, wherein forming the sub master comprises:

forming the prism pattern in a substrate;

scattering beads on the prism pattern;

pressurizing the beads; and

removing the beads from the substrate to form an irregular diffusion pattern on the prism pattern.

17. The method of claim 16, wherein forming the diffusion pattern comprises forming the diffusion pattern by uniformly scattering at least one of a concave form, a convex form, and a polyhedral form

18. The method of claim 17, wherein forming the prism pattern comprises uniformly forming the mountains in one of a straight line and a curved line.

19. The method of claim 18, wherein forming the prism pattern comprises forming the mountains at irregular intervals.

20. The method of claim 19, wherein forming the prism pattern comprises forming each mountain with a round peak.