Discrete light guide-based planar illumination area

• US 8,064,743 B2
• Filed: 09/23/2010
• Issued: 11/22/2011
• Est. Priority Date: 12/19/2007
• Status: Active Grant

• Current Assignee: Oree Advanced Illumination Solutions Ltd.
• Original Assignee: Oree, Inc.
• Inventors: Zimmermann, Micha, Meir, Noam, Shani, Yosi
• Primary Examiner(s): Rahll; Jerry
• Application Number:
  US12/888,932
• Publication Number:
  US 20110013415A1
• Time in Patent Office: 425 Days
• Field of Search: 385/31, 349/65, 362/616, 362/628
• US Class Current: 385/31
• CPC Class Codes: G02B 6/0065 Manufacturing aspects; Material aspects
• CPC Class Codes: G02B 6/0068 Arrangements of plural sources, e.g. multi-colour light sources
• CPC Class Codes: G02B 6/0073 Light emitting diode [LED]
• CPC Class Codes: G02B 6/008 of the partially overlapping type
• CPC Class Codes: G02B 6/0088 of the light guide or other optical sheets in the package

Abstract

In one aspect, a planar illumination area includes two light-guide elements, each with an out-coupling region. At least a portion of each out-coupling region overlaps with at least a portion of the other. The overlapping region emits a substantially uniform light output power.

Claims

1. A planar illumination area comprising:

a first discrete light-guide element comprising (i) first and second adjoining non-parallel sidewalls spanning top and bottom surfaces, the first sidewall being reflective, and (ii) an out-coupling region partially bounded by the sidewalls; and

a second discrete light-guide element comprising (i) first and second adjoining non-parallel sidewalls spanning top and bottom surfaces, the first sidewall being reflective, and (ii) an out-coupling region partially bounded by the sidewalls, the first sidewall of the second light-guide element being adjacent and opposed to the first sidewall of the first light-guide element,

wherein (i) light in the first light-guide element striking its first sidewall substantially reflects therefrom rather than travelling into the second light-guide element, and (ii) light in the second light-guide element striking its first sidewall substantially reflects therefrom rather than travelling into the first light-guide element.

2. The planar illumination area of claim 1, further comprising a diffuser sheet disposed over the first and second light-guide elements.

4. The planar illumination area of claim 1, wherein the first sidewalls of the first and second light-guide elements are polished.

5. The planar illumination area of claim 4, wherein the first sidewalls of the first and second light-guide elements are polished to a tolerance less than approximately 600 nm peak-to-peak.

6. The planar illumination area of claim 1, wherein the first sidewalls of the first and second light-guide elements have a reflective coating thereon.

7. The planar illumination area of claim 1, wherein the first and second sidewalls of the first light-guide element are perpendicular to the top and bottom surfaces of the first light-guide element, and the first and second sidewalls of the second light-guide element are perpendicular to the top and bottom surfaces of the second light-guide element.

8. The planar illumination area of claim 7, wherein the first and second sidewalls of the first light-guide element form right angles to the top and bottom surfaces of the first light-guide element, and the first and second sidewalls of the second light-guide element form right angles with the top and bottom surfaces of the second light-guide element.

9. The planar illumination area of claim 1, wherein each of the out-coupling regions comprises at least one of an optical element, a microlens, or a plurality of light-scattering particles.

10. The planar illumination area of claim 1, wherein each of the first and second light-guide elements comprises, spatially distinct from its out-coupling region, an in-coupling region, whereby light entering the in-coupling region is substantially retained within the light-guide element for emission from the out-coupling region.

11. The planar illumination area of claim 10, wherein each of the first and second light-guide elements comprises a light-emitting diode embedded within the in-coupling region.

12. The planar illumination area of claim 11, further comprising, disposed in each in-coupling region, an optical element for in-coupling light from the light-emitting diode.

13. The planar illumination area of claim 10, wherein each of the first and second light-guide elements comprises a propagation region through which light from the in-coupling region travels before reaching the out-coupling region.

14. The planar illumination area of claim 10, further comprising, (i) joined to each of the first and second light-guide elements, a sub-assembly platform, the connection between the sub-assembly platform and the light-guide element forming a socket therebetween in the in-coupling region, and (ii) a discrete light source disposed within each socket.

15. The planar illumination area of claim 14, wherein each discrete light source comprises a bare-die light-emitting diode.

16. The planar illumination area of claim 14, further comprising an encapsulation material disposed within each socket.

17. The planar illumination area of claim 14, wherein each discrete light source is electrically and thermally connected to its respective sub-assembly platform.

18. The planar illumination area of claim 1, wherein the second sidewalls of the first and second discrete light-guide elements are reflective.

19. The planar illumination area of claim 1, further comprising:

a third discrete light-guide element comprising (i) first and second adjoining non-parallel sidewalls spanning top and bottom surfaces, the first sidewall being reflective, and (ii) an out-coupling region partially bounded by the sidewalls, the first sidewall of the third light-guide element being adjacent and opposed to the second sidewall of the first light-guide element,

wherein (i) the second sidewall of the first discrete light-guide element is reflective, (ii) light in the first light-guide element striking its second sidewall substantially reflects therefrom rather than travelling into the third light-guide element, and (ii) light in the third light-guide element striking its first sidewall substantially reflects therefrom rather than travelling into the first light-guide element.

3. A planar illumination area comprising:

a first discrete light-guide element comprising (i) first and second adjoining non-parallel sidewalls spanning top and bottom surfaces, the first sidewall being reflective, and (ii) an out-coupling region partially bounded by the sidewalls; and

a second discrete light-guide element comprising (i) first and second adjoining non-parallel sidewalls spanning top and bottom surfaces, the first sidewall being reflective, and (ii) an out-coupling region partially bounded by the sidewalls, the first sidewall of the second light-guide element being adjacent and opposed to the first sidewall of the first light-guide element,

wherein (i) light in the first light-guide element striking its first sidewall substantially reflects therefrom rather than travelling into the second light-guide element, and (ii) light in the second light-guide element striking its first sidewall substantially reflects therefrom rather than travelling into the first light-guide element,

and further comprising additional discrete light-guide elements forming, with the first and second light-guide elements, an array extending in first and second non-parallel directions, wherein the light-guide elements do not overlap in the first or second direction.

20. A planar illumination area comprising:

a first discrete light-guide element comprising (i) first and second adjoining non-parallel sidewalls spanning top and bottom surfaces, the first sidewall being reflective, and (ii) an out-coupling region partially bounded by the sidewalls; and

a second discrete light-guide element comprising (i) first and second adjoining non-parallel sidewalls spanning top and bottom surfaces, the first sidewall being reflective, and (ii) an out-coupling region partially bounded by the sidewalls, the first sidewall of the second light-guide element being adjacent and opposed to the first sidewall of the first light-guide element,

wherein (i) light in the first light-guide element striking its first sidewall substantially reflects therefrom rather than travelling into the second light-guide element, (ii) light in the second light-guide element striking its first sidewall substantially reflects therefrom rather than travelling into the first light-guide element, (iii) each of the first and second light-guide elements comprises, spatially distinct from its out-coupling region, an in-coupling region, whereby light entering the in-coupling region is substantially retained within the light-guide element for emission from the out-coupling region, and (iv) each in-coupling region comprises a reflector to redirect light toward the out-coupling region.

21. A planar illumination area comprising:

a first discrete light-guide element comprising (i) first and second adjoining non-parallel sidewalls spanning top and bottom surfaces, the first sidewall being reflective, and (ii) an out-coupling region partially bounded by the sidewalls; and

a second discrete light-guide element comprising (i) first and second adjoining non-parallel sidewalls spanning top and bottom surfaces, the first sidewall being reflective, and (ii) an out-coupling region partially bounded by the sidewalls, the first sidewall of the second light-guide element being adjacent and opposed to the first sidewall of the first light-guide element,

wherein (i) light in the first light-guide element striking its first sidewall substantially reflects therefrom rather than travelling into the second light-guide element, (ii) light in the second light-guide element striking its first sidewall substantially reflects therefrom rather than travelling into the first light-guide element, (iii) each of the first and second light-guide elements comprises, spatially distinct from its out-coupling region, an in-coupling region, whereby light entering the in-coupling region is substantially retained within the light-guide element for emission from the out-coupling region, and (iv) in each of the first and second light-guide elements, light is emitted into the in-coupling region in a first direction, light propagates through the light-guide element in a second direction substantially perpendicular to the first direction, and is emitted from the out-coupling region in a third direction substantially perpendicular to the second direction.