LIGHTGUIDES HAVING CURVED LIGHT INJECTORS

• US 20080260329A1
• Filed: 04/20/2007
• Published: 10/23/2008
• Est. Priority Date: 04/20/2007
• Status: Abandoned Application

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Epstein, Kenneth A.
• Application Number:
  US11/738,186
• Publication Number:
  US 20080260329A1
• Time in Patent Office: Days
• US Class Current: 385/32
• CPC Class Codes: G02B 6/0021 for housing at least a part of the light source, e.g. by forming holes or recesses
• CPC Class Codes: G02B 6/0028 Light guide, e.g. taper

Abstract

An optical system has a lightguide having a confinement direction and a first light source disposed proximate a periphery of the lightguide. A light injector is disposed to couple light from the first light source into the lightguide. The light injector has a surface formed with a confinement curve for confining light in the confinement direction. The light injector may be disposed at either a recess on the periphery of the lightguide or at a cut corner of the lightguide. A refractive structure, having at least one surface non-perpendicular to an emission axis of the light source may be disposed between the injector and the lightguide. At least a portion of the injector may have a shape corresponding to a confinement curve that is rotated about an axis parallel to the confinement direction.

Claims

1. An optical system, comprising:

a lightguide having a confinement direction;

a first light source disposed proximate a periphery of the lightguide, light from the first light source being directed substantially around an emission axis, the emission axis being perpendicular to the confinement direction; and

a first light injector disposed to couple light from the first light source into the lightguide, the first light injector having a surface formed with a confinement curve for confining light in the confinement direction, and being disposed at one of a recess on the periphery of the lightguide and a cut corner of the lightguide.

2. A system as recited in claim 1, wherein the lightguide has an edge comprising a light coupling section shaped to receive the first light injector.

3. A system as recited in claim 2, wherein the light coupling section comprises a notch in a side of the lightguide, the first light injector having an output surface substantially conforming in shape to the notch of the lightguide.

4. A system as recited in claim 2, wherein the light coupling section comprises a cut at a corner of the lightguide, the first light injector comprising a surface matched to the cut corner of the lightguide.

5. A system as recited in claim 1, wherein lightguide is formed with a confinement curve rotated about an axis parallel to the confinement direction.

6. A system as recited in claim 5, wherein the injector is formed of a first section having a shape corresponding to the confinement curve being rotated about a first axis parallel to the confinement direction, a second section having a shape corresponding to the confinement curve being translated in a direction perpendicular to the confinement direction and a third section having a shape corresponding to the confinement curve being rotated about a second axis parallel to the confinement direction, the second section being positioned between the first and third sections.

7. A system as recited in claim 6, wherein at least a portion of an output face of the second section is substantially perpendicular to the emission axis.

8. A system as recited in claim 6, wherein an output face of the second section has at least one surface portion disposed non-perpendicularly relative to the emission axis.

9. A system as recited in claim 6, wherein the confinement curve of the first section is rotated by 90°

about the axis parallel to the confinement direction and the confinement curve of the third section is rotated by 90°

about the axis parallel to the confinement direction, the first light injector being disposed along an edge of the lightguide.

10. A system as recited in claim 6, wherein the confinement curve of the first section is rotated by 45°

about the axis parallel to the confinement direction and the confinement curve of the third section is rotated by 45°

about the axis parallel to the confinement direction, the first light injector being disposed at a corner of the lightguide.

11. A system as recited in claim 5, wherein the output face of the first injector is substantially semicircular and is located in a semicircular notch of the lightguide.

12. A system as recited in claim 1, wherein the first light injector has a substantially flat output surface that is matched to a substantially flat portion at a cut corner of the lightguide.

13. A system as recited in claim 12, wherein the flat portion of the cut corner is at 45°

relative to edges of the lightguide.

14. A system as recited in claim 1, further comprising a refractive structure disposed between the first injector and the lightguide.

15. A system as recited in claim 14, wherein the refractive structure is formed as a notch on the output surface of the first injector.

16. A system as recited in claim 14, wherein the refractive structure comprises two flat surfaces disposed at different angles relative to the emission axis.

17. A system as recited in claim 14, wherein the refractive structure comprises a curved surface.

18. A system as recited in claim 1, wherein the first light source comprises a light emitting diode (LED).

19. A system as recited in claim 18, wherein the first light source further comprises a phosphor disposed so as to convert at least some of the light emitted by the LED at a first wavelength to light at a second wavelength different from the first wavelength.

20. A system as recited in claim 1, further comprising a display panel disposed beside the lightguide, light from the lightguide illuminating a back side of the display panel.

21. A system as recited in claim 20, further comprising one or more light management films disposed between the lightguide and the display panel and a reflector, the lightguide being disposed between the reflector and the light management films.

22. A system as recited in claim 20, further comprising a controller coupled to control an image displayed by the display panel.

23. A system as recited in claim 1, further comprising second light source and a second confinement curve injector coupling light between the second light source and the lightguide.

24. An optical system, comprising:

a first light emitting diode capable of emitting light generally about an emission axis;

a lightguide having a confinement direction substantially perpendicular to the emission axis;

a first injector coupling light from the first light emitting diode to the lightguide, the first injector having confinement curve-shaped surfaces shaped so as to confine light in a direction parallel to the confinement direction of the lightguide; and

a refractive structure disposed between the first injector and the lightguide, the refractive structure having at least one surface non-perpendicular to the emission axis of the light emitting diode.

25. An optical system as recited in claim 24, wherein the refractive structure has at least two flat surfaces disposed non-perpendicular to the emission axis.

26. An optical system as recited in claim 24, wherein the refractive structure has at least one curved surface.

27. An optical system as recited in claim 24, wherein the refractive structure is air filled.

28. An optical system as recited in claim 24, wherein the first injector has no sides having a confinement curve for confining light in a direction orthogonal to the confinement direction.

29. An optical system, comprising:

a first light emitting diode capable of emitting light generally about an emission axis;

a lightguide having a confinement direction substantially perpendicular to the emission axis;

a first injector coupling light from the first light emitting diode to the lightguide, the first injector having confinement curve-shaped surfaces shaped so as to confine light in a direction parallel to the confinement direction of the lightguide, at least a portion of the first injector having a shape corresponding to a confinement curve that is rotated about an axis parallel to the confinement direction.

30. An optical system as recited in claim 29, wherein the first injector comprises a first section having a shape corresponding to the confinement curve being rotated about a first axis parallel to the confinement direction, a second section having a shape corresponding to the confinement curve being translated in a direction perpendicular to the confinement direction and a third section having a shape corresponding to the confinement curve being rotated about a second axis parallel to the confinement direction, the second section being positioned between the first and third sections.

31. A system as recited in claim 30, wherein at least a portion of an output face of the second section is substantially perpendicular to the emission axis.

32. A system as recited in claim 30, wherein an output face of the second section has at least one surface portion disposed non-perpendicularly relative to the emission axis.

33. A system as recited in claim 30, wherein the confinement curve of the first section is rotated by 90°

about the axis parallel to the confinement direction and the confinement curve of the third section is rotated by 90°

about the axis parallel to the confinement direction, the first light injector being disposed along an edge of the lightguide.

34. A system as recited in claim 30, wherein the confinement curve of the first section is rotated by 45°

about the axis parallel to the confinement direction and the confinement curve of the third section is rotated by 45°

about the axis parallel to the confinement direction, the first light injector being disposed at a corner of the lightguide.