Waveguide sheet containing in-coupling, propagation, and out-coupling regions

• US 8,542,964 B2
• Filed: 07/05/2012
• Issued: 09/24/2013
• Est. Priority Date: 12/19/2007
• Status: Active Grant

• Current Assignee: Oree Advanced Illumination Solutions Ltd.
• Original Assignee: Oree, Inc.
• Inventors: Meir, Noam, Fine, Eran
• Primary Examiner(s): PAK, SUNG H
• Application Number:
  US13/542,089
• Publication Number:
  US 20130003348A1
• Time in Patent Office: 446 Days
• Field of Search: None
• US Class Current: 385/39
• CPC Class Codes: G02B 6/0041 provided in the bulk of the light guide
• CPC Class Codes: G02B 6/0065 Manufacturing aspects; Material aspects
• CPC Class Codes: G02B 6/0076 Stacked arrangements of multiple light guides of the same or different cross-sectional area
• CPC Class Codes: G02B 6/0078 Side-by-side arrangements, e.g. for large area displays

Abstract

In one aspect, an illumination structure includes a substantially non-fiber waveguide, which itself includes a discrete in-coupling region for receiving light, a discrete propagation region for propagating light, and a discrete out-coupling region for emitting light.

Claims

1. An illumination structure comprising one or more optical elements for at least one of in-coupling or out-coupling light, the illumination structure comprising:

a substantially non-fiber waveguide having an index of refraction and comprising;

a discrete in-coupling region for receiving light,

a discrete propagation region for retaining light therein and propagating light from the in-coupling region to an out-coupling region, light being retained within at least a portion of the propagation region via only total internal reflection at a boundary between the waveguide and air or a cladding material having an index of refraction lower than the index of refraction of the waveguide,

a discrete out-coupling region for emitting light, the in-coupling, propagation, and out-coupling regions being spatially distinct, light entering the in-coupling region being substantially retained within the waveguide for emission from the out-coupling region,

wherein light emitted from a surface of the waveguide in the out-coupling region has a predetermined optical profile comprising both (i) substantial uniformity of color profile and (ii) substantial uniformity of intensity.

2. The illumination structure of claim 1, wherein the propagation region is substantially free of the one or more optical elements.

3. The illumination structure of claim 1, wherein the one or more optical elements comprises at least one microlens.

4. The illumination structure of claim 1, wherein the one or more optical elements comprises a plurality of photoluminescent particles.

5. The illumination structure of claim 1, wherein the color profile comprises white light.

6. The illumination structure of claim 1, wherein an optical mean free path of light in the in-coupling region is different from an optical mean free path of light in the propagation region.

7. The illumination structure of claim 6, wherein the optical mean free path of light in the in-coupling region is less than the optical mean free path of light in the propagation region.

8. The illumination structure of claim 1, wherein the out-coupling region comprises the one or more optical elements.

9. The illumination structure of claim 8, wherein the one or more optical elements comprises a plurality of hemispheres.

10. The illumination structure of claim 9, wherein the hemispheres have a concentration that varies across at least one dimension of the out-coupling region.

11. The illumination structure of claim 10, wherein the concentration of the hemispheres increases with distance from the in-coupling region.

12. The illumination structure of claim 9, wherein the hemispheres have a dimension that varies across at least one dimension of the out-coupling region.

13. The illumination structure of claim 9, wherein the out-coupling region comprises a plurality of core structures, at least some of which comprise hemispheres, and wherein at least one of a size, a concentration, or a type of the hemispheres varies among at least two of the core structures.

14. The illumination structure of claim 9, wherein the in-coupling region comprises a microlens.

15. The illumination structure of claim 1, further comprising a light emitter disposed proximate the in-coupling region.

16. The illumination structure of claim 1, further comprising a light emitter disposed within the waveguide.

17. The illumination structure of claim 16, wherein the light emitter consists essentially of a bare-die light-emitting diode.

18. The illumination structure of claim 1, further comprising a reflector disposed proximate a surface of the in-coupling region.

19. The illumination structure of claim 1, wherein the waveguide is substantially planar.

20. The illumination structure of claim 1, wherein an optical mean free path of light in the propagation region is substantially constant, and an optical mean free path of light in the out-coupling region varies substantially monotonically.

21. The illumination structure of claim 1, wherein the in-coupling region receives light entering in a first direction, the propagation region propagates light in a second direction perpendicular to the first direction, and the out-coupling region emits light in a third direction perpendicular to the second direction.

22. The illumination structure of claim 1, further comprising a photoluminescent layer disposed on a light-emitting surface of the out-coupling region.

23. The illumination structure of claim 22, further comprising a light emitter proximate the in-coupling region, the light emitter having substantially no direct line-of-sight to the photoluminescent layer.

24. The illumination structure of claim 22, further comprising a light emitter proximate the in-coupling region, the light emitter having a direct line-of-sight to the photoluminescent layer.