Flat-panel area illumination system

• US 20060083004A1
• Filed: 10/15/2004
• Published: 04/20/2006
• Est. Priority Date: 10/15/2004
• Status: Abandoned Application

• Current Assignee: Global OLED Technology LLC (LG Display Co., Ltd.)
• Original Assignee: Eastman Kodak Company
• Inventors: Cok, Ronald S.
• Application Number:
  US10/966,210
• Publication Number:
  US 20060083004A1
• Time in Patent Office: Days
• US Class Current: 362/330
• CPC Class Codes: G02B 5/045 Prism arrays
• CPC Class Codes: G02B 6/0053 Prismatic sheet or layer; Brightness enhancement element, sheet or layer
• CPC Class Codes: H10K 50/858 comprising refractive means, e.g. lenses
• CPC Class Codes: H10K 59/879 comprising refractive means, e.g. lenses

Abstract

A flat-panel area illumination system is described, comprising: a) a flat-panel lamp having a substrate and one or more non-pixellated light-emitting areas formed on the substrate emitting light in every direction from at least one light-emitting side of the lamp; and b) a light-directing optical film located on the at least one light-emitting side over the light-emitting area of the flat-panel lamp, wherein the light-directing optical film preferentially directs light away from a direction perpendicular to the surface of the light-emitting side of the flat-panel lamp. The flat-panel lamp system of the present invention provides light direction capability for a flat-panel OLED lamp while preserving a thin profile.

Claims

1. A flat-panel area illumination system, comprising:

a) a flat-panel lamp having a substrate and one or more non-pixellated light-emitting areas formed on the substrate emitting light in every direction from at least one light-emitting side of the lamp; and

b) a light-directing optical film located on the at least one light-emitting side over the light-emitting area of the flat-panel lamp, wherein the light-directing optical film preferentially directs light away from a direction perpendicular to the surface of the light-emitting side of the flat-panel lamp.

2. The flat-panel area illumination system claimed in claim 1, wherein the light-directing optical film includes a structured surface located adjacent to the light-emitting side of the flat-panel lamp.

3. The flat-panel area illumination system claimed in claim 2, wherein the light-directing optical film includes a flat surface located opposite to the light-emitting side of the flat-panel lamp.

4. The flat-panel area illumination system of claim 3, wherein a plurality of structures are associated with each light emitting area.

5. The flat-panel area illumination system claimed in claim 3, wherein the structured surface comprises triangular prisms.

6. The flat-panel area illumination system claimed in claim 3, wherein the structured surface comprises cylindrical lenses.

7. The flat-panel area illumination system claimed in claim 3, wherein the structured surface comprises a plurality of wedge-shaped structures having a long axis and in which the axes of the wedge-shaped structures are aligned in a common direction.

8. The flat-panel area illumination system claimed in claim 7, wherein the wedge-shaped structures are formed into parallel lines.

9. The flat-panel area illumination system claimed in claim 7, wherein the wedge-shaped structures are not formed into parallel lines.

10. The flat-panel area illumination system claimed in claim 7, wherein the wedge-shaped structures are formed in pairs of facing wedge-shaped structures.

11. The flat-panel area illumination system claimed in claim 1, wherein the light-directing optical film comprises a plastic or a glass.

12. The flat-panel area illumination system of claim 1, wherein the flat-panel lamp is an OLED lamp.

13. The flat-panel area illumination system of claim 1, further comprising a diffuser located between the light-directing optical film and the flat-panel lamp.

14. The flat-panel area illumination system of claim 1, further comprising a second light-directing optical film located over the light directing optical film and parallel to the light-directing optical film

15. The flat-panel area illumination system of claim 14, wherein light-directing structures of the second light-directing optical film are at a different angle to light-directing structures of the light-directing optical film.

16. The flat-panel area illumination system of claim 15, wherein the structures of the second light-directing optical film are at 90 degrees to the structures of the light-directing optical film.

17. The flat-panel area illumination system of claim 1, wherein the light-directing optical film is divided into a plurality of regions and light-directing structures in one region are oriented at a different angle from light-directing structures in a second region.

18. The flat-panel area illumination system of claim 17, wherein the structures within the regions alternate in orientation.

19. The flat-panel area illumination system of claim 17, wherein the structures within one region are oriented at 90 degrees with respect to the structures in another region.

20. The flat-panel area illumination system of claim 17, having at least four regions and wherein the structures within one region are oriented at multiples of 45 degrees with respect to the structures in another region.

21. The flat-panel area illumination system of claim 1, wherein the light-directing optical film is flexible.

22. The flat-panel area illumination system of claim 1, wherein the flat-panel lamp is flexible.

23. The flat-panel area illumination system of claim 1, wherein the light-emitting areas emit light in every direction from the light-emitting side in approximately the same amount.

24. The flat-panel area illumination system of claim 1, wherein the flat-panel lamp emits light from more than one side and a light-directing optical film is located over each light-emitting side.

25. The flat-panel area illumination system of claim 1, wherein the flat-panel lamp emits light through the substrate.

26. The flat-panel area illumination system of claim 1, wherein the flat-panel lamp further comprises an encapsulating cover located over the substrate and the light emitting area.

27. The flat-panel area illumination system of claim 26, wherein the emitted light is emitted through the cover.

28. The flat-panel area illumination system of claim 27, wherein the optical film is formed in the inside of the cover.

29. The flat-panel area illumination system of claim 27, wherein the optical film is located on the inside of the cover.

30. A method of making a flat-panel area illumination system, comprising the steps of:

a) providing a flat-panel lamp having a substrate with at least one non-pixellated light-emitting area formed on the substrate emitting light in every direction from at least one light-emitting side of the lamp;

b) providing a light-directing optical film that preferentially directs light away from a direction perpendicular to the surface of the light-emitting side of the flat-panel lamp; and

c) locating the optical film over the light-emitting area on the at least one light-emitting side of the flat-panel lamp.

31. The method claimed in claim 30, wherein the flat-panel lamp and the light-directing optical film are formed from a web in a continuous roll.

32. The method claimed in claim 31, wherein the light-directing optical film is formed by injection roll molding.