Waveguide bodies including redirection features and methods of producing same

• US 9,442,243 B2
• Filed: 12/09/2013
• Issued: 09/13/2016
• Est. Priority Date: 01/30/2013
• Status: Active Grant

• Current Assignee: IDEAL Industries Lighting, LLC (Ideal Industries Incorporated)
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Tarsa, Eric J.
• Primary Examiner(s): PEACE, RHONDA S
• Application Number:
  US14/101,132
• Publication Number:
  US 20140211503A1
• Time in Patent Office: 1,009 Days
• US Class Current: 1/1
• CPC Class Codes: G02B 6/0016 Grooves, prisms, gratings, scattering particles or rough surfaces
• 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 6/0031 Reflecting element, sheet or layer
• CPC Class Codes: G02B 6/0036 2-D arrangement of prisms, protrusions, indentations or roughened surfaces
• CPC Class Codes: G02B 6/0068 Arrangements of plural sources, e.g. multi-colour light sources
• CPC Class Codes: G02B 6/0076 Stacked arrangements of multiple light guides of the same or different cross-sectional area

Abstract

According to one aspect, a waveguide includes a body exhibiting a total internal reflectance characteristic and having a first face and a second face opposite the first face wherein the first and second faces extend along a lateral direction and a coupling cavity adapted to receive a light emitting diode (LED) that is configured to direct light into the body. The body additionally includes an extraction feature disposed on one of the first and second faces and configured to direct light traveling through the body out of at least one of the first and second faces. The body further includes a redirection feature disposed at least in part between the first and second faces and disposed between the coupling cavity and the extraction feature along the lateral direction, and configured to redirect light traveling through the body laterally within the body.

Claims

1. A waveguide, comprising:

a body made of at least one optically transmissive material and exhibiting a total internal reflectance characteristic wherein the body comprises a first plate and a second plate, the body comprising a first face and a second face opposite the first face wherein the first and second faces extend along a lateral direction and a coupling cavity adapted to receive a light emitting diode (LED) that is configured to direct light into the body;

wherein the body comprises an extraction feature disposed on one of the first and second faces and configured to direct light traveling through the body out of at least one of the first and second faces; and

wherein the body further comprises a redirection feature disposed at least in part between the first and second faces and disposed between the coupling cavity and the extraction feature along the lateral direction, and wherein the redirection feature is formed in the at least one optically transmissive material of the body such that the redirection feature is integral with the body and is configured to redirect light traveling through the body laterally within the body.

2. The waveguide of claim 1, wherein the redirection feature redirects light emitted from the LED such that the light is extracted at a modified extraction point.

3. The waveguide of claim 1, wherein the redirection feature promotes enhanced light uniformity within the body.

4. The waveguide of claim 3, wherein multiple color LEDs are disposed in the coupling cavity.

5. The waveguide of claim 4, wherein the redirection feature promotes enhanced color uniformity within the body.

6. The waveguide of claim 1, wherein the coupling cavity comprises a light coupling feature extending into the body.

7. The waveguide of claim 1, wherein the redirection feature directs some light out of the body.

8. The waveguide of claim 1, wherein the body comprises a width that is substantially greater than an overall thickness thereof.

9. The waveguide of claim 8, wherein each of the first and second plates comprise a width that is substantially greater than an overall thickness thereof, and wherein the first and second plates are secured together along the width thereof.

10. The waveguide of claim 1, wherein the redirection feature comprises a thickness of no greater than about 1 um.

11. The waveguide of claim 1, wherein the redirection feature comprises a thickness between about 10 um and about 10 mm.

12. The waveguide of claim 1, wherein the redirection feature comprises a thickness between about 1 mm and about 10 mm.

13. The waveguide of claim 1, wherein the redirection feature comprises a thickness between about 1% or less to 100% of a thickness of the body.

14. The waveguide of claim 1, wherein the redirection feature extends away from the coupling cavity.

15. The waveguide of claim 14, wherein the redirection feature comprises a shape comprising one of a rectangle, a V-shape, and two opposing arcs.

16. The waveguide of claim 1, wherein the body comprises a plurality of redirection features, wherein the plurality of redirection features extend away from the coupling cavity.

17. The waveguide of claim 1, wherein the redirection feature comprises a void that is filled with one or more of air, acrylic, an acrylic material with scattering particles, polycarbonate, glass, molded silicone, and a cyclic olefin copolymer.

18. The waveguide of claim 17, wherein at least one of a specular and reflective material is disposed on a surface at least in part defining the void.

19. The waveguide of claim 1, in combination with an LED disposed in a coupling cavity wherein the redirection feature collimates light developed by the LED.

20. The waveguide of claim 1, in combination with an LED disposed in a coupling cavity wherein the redirection feature causes light to avoid a feature in the body.

21. A waveguide body, comprising:

a first plate exhibiting a total internal reflectance characteristic and comprising a first face and a second face opposite the first face;

a second plate exhibiting a total internal reflectance characteristic and comprising a third face and a fourth face opposite the third face; and

a redirection feature integrally formed in the first plate and associated with the second face and configured to redirect light traveling laterally within the body and wherein the redirection feature directs some light traveling laterally in the waveguide body and emitted from a light source out of the waveguide body;

wherein the second face of the first plate is secured to the third face of the second plate.

22. The waveguide body of claim 21, wherein a further redirection feature is formed in the second plate and is associated with the third face of the second plate.

23. The waveguide body of claim 21, further comprising a coupling cavity adapted to receive the light source and configured to direct light into the waveguide body.

24. The waveguide body of claim 21, further comprising an extraction feature on one of the first and fourth faces.

25. The waveguide body of claim 21, wherein the first and second plates comprise the same material.

26. The waveguide body of claim 21, wherein the first and second plates comprise the different materials.

27. A method of producing a waveguide, the method comprising the steps of:

providing first and second light transmissive bodies each exhibiting a total internal reflectance characteristic wherein each of the first and second light transmissive bodies comprises a pair of opposed major faces;

forming a redirection feature extending into the first light transmissive body from a surface thereof such that at least a portion of the redirection feature engages with the surface and disposing the redirection feature in one of the major faces of the first light transmissive body; and

securing the second light transmissive body to the surface of the first light transmissive body.

28. The method of claim 27, wherein the step of providing comprises the step of supplying substantially planar first and second light transmissive bodies.

29. The method of claim 27, wherein the step of securing comprises the step of securing a major face of the second light transmissive body to the one major face of the first light transmissive body.

30. The method of claim 27, further comprising the step of disposing a further redirection feature in one of the major faces of the second light transmissive body, and wherein the step of securing comprises the step of bonding the one major face of the second light transmissive body to the one major face of the first light transmissive body.

31. The method of claim 27, further comprising the step of providing a light extraction feature associated with at least one of the first and second light transmissive bodies.

32. The method of claim 27, further comprising the steps of forming a coupling cavity in at least one of the first and second light transmissive bodies and disposing an LED in the coupling cavity.

33. The method of claim 27, further comprising the steps of forming a coupling cavity in at least one of the first and second light transmissive bodies and disposing a plurality of LEDs in the coupling cavity.

34. The method of claim 33, wherein the plurality of LEDs comprises first and second LEDs of different colors and wherein the light redirection feature promotes mixing of the different colors.

35. The method of claim 33, wherein the plurality of LEDs comprises first and second LEDs of a same color and wherein the light redirection feature promotes mixing of light produced by the first and second LEDs.

36. The method of claim 33, wherein the light redirection feature extends away from the plurality of LEDs.

37. The method of claim 33, wherein the coupling cavity is disposed at an interior portion of the first and second light transmissive bodies.