Asymmetric alternating prism arrays

• US 20010040799A1
• Filed: 11/29/2000
• Published: 11/15/2001
• Est. Priority Date: 12/02/1999
• Status: Active Grant

• Current Assignee: Reflexite
• Original Assignee: Reflexite
• Inventors: Munro, James F., Futhey, John A.
• Granted Patent: US 6,854,855 B2
• Time in Patent Office: Days
• US Class Current: 362/26
• CPC Class Codes: G02B 6/0038 Linear indentations or grooves, e.g. arc-shaped grooves or meandering grooves, extending over the full length or width of the light guide
• CPC Class Codes: G02B 6/0058 varying in density, size, shape or depth along the light guide

Abstract

A luminaire is provided which includes a light source, a light guide that receives light radiating from the light source, and a plurality of prisms adjacent the light guide that redirect the light from the light guide substantially perpendicular to a longitudinal axis of the light guide. The prism angles, in one embodiment, are 25°-90°-65°. The fine pitch prism arrays preferably alternate or flip-flop every few millimeters, for example, one to two millimeters to create the visual appearance of bright and dark bands which cause the structure to appear like macro prisms.

Claims

1. A luminaire, comprising:

a light source;

a light guide that receives light radiating from the light source; and

a plurality of tilted prism arrays for redirecting the light in a first direction, wherein the plurality of prism arrays periodically alternate orientation along the light guide.

2. The luminaire of

claim 1

wherein the plurality of prism arrays include linear prisms.

3. The luminaire of

claim 2

wherein the linear prisms have included angles of 25, 90, and 65 degrees.

4. The luminaire of

claim 1

wherein the prism arrays include peaks and valleys along a first axis.

5. The luminaire of

claim 1

wherein the prism arrays include peaks and valleys along a second axis different than the first axis.

6. The luminaire of

claim 5

wherein the second axis is substantially perpendicular to the first axis.

7. The luminaire of

claim 5

wherein the second axis is offset about 60 degrees relative to the first axis.

8. The luminaire of

claim 5

wherein the prism arrays include peaks and valleys along a third axis that is different than the second axis and the first axis.

9. The luminaire of

claim 8

wherein the third axis is offset about 60 degrees relative to the second axis.

10. The luminaire of

claim 1

wherein the light guide is substantially solid.

11. The luminaire of

claim 10

wherein the light guide includes polymethyl methacrylate.

12. The luminaire of

claim 1

wherein the plurality of prism arrays are disposed on a top surface of the light guide.

13. The luminaire of

claim 1

further comprising a reflective surface below the light surface for redirecting light into the light guide.

14. The luminaire of

claim 1

further comprising a reflective surface adjacent at least one end of the light guide for redirecting light toward the light guide.

15. The luminaire of

claim 1

further comprising a baffle for scattering light into the light guide.

16. The luminaire of

claim 1

wherein the prism arrays include prism facets having more than one plane on at least one facet.

17. The luminaire of

claim 1

wherein the prism arrays include curved prism tips.

18. The luminaire of

claim 1

wherein the prism arrays include curved valleys.

25. The luminaire of

claim 1

wherein the prism arrays include curved prism tips.

26. The luminaire of

claim 1

wherein the prism arrays include curved valleys.

19. An optical microstructure comprising a plurality of tilted prism arrays that periodically alternate orientation of the tilted prism arrays along a first axis.

20. The optical microstructure of

claim 19

wherein the prism arrays periodically alternate orientation of the tilted prism arrays along a second axis.

21. The optical microstructure of

claim 19

wherein the prism arrays periodically alternate orientation of the tilted prism arrays along a third axis.

22. The optical microstructure of

claim 19

wherein the optical microstructure is disposed on first surface of a film, further comprising a plurality of prism arrays on a second surface of the film.

23. The optical microstructure of

claim 22

wherein the plurality of prism arrays on the second surface are tilted and periodically alternate orientation along at least one axis.

24. The luminaire of

claim 19

wherein the prism arrays include prism facets having more than one plane on at least one facet.

27. A luminaire comprising:

a light source;

a light guide that receives light radiating from the light source; and

a plurality of tilted prism arrays for redirecting the light exiting the light guide, the prism arrays periodically alternating orientation along a first axis.

28. The luminaire of

claim 27

wherein the prism arrays periodically alternate orientation along a second axis.

29. The luminaire of

claim 28

wherein the prism arrays periodically alternate orientation along a third axis.

30. The luminaire of

claim 27

wherein the plurality of prism arrays are disposed on a top surface of the light guide.

31. A method for redirecting light comprising:

providing a light source;

receiving light radiating from the light source in a light guide; and

redirecting the light in a first direction with a plurality of tilted prism arrays that periodically alternate orientation along a first axis.

32. The method of

claim 31

further comprising the step of periodically alternating the plurality of tilted prism arrays along a second axis different than the first axis.

33. The method of

claim 31

further comprising the step of periodically alternating the plurality of tilted prism arrays along a third axis different than the second axis and the first axis.

34. The method of

claim 31

further comprising the step of redirecting the light radiating from the light source toward the plurality of tilted prism arrays.