Discrete lighting elements and planar assembly thereof

• US 8,172,447 B2
• Filed: 11/26/2008
• Issued: 05/08/2012
• Est. Priority Date: 12/19/2007
• Status: Active Grant

• Current Assignee: Oree Advanced Illumination Solutions Ltd.
• Original Assignee: Oree, Inc.
• Inventors: Meir, Noam, Zimmermann, Micha
• Primary Examiner(s): Husar, Stephen F
• Application Number:
  US12/324,540
• Publication Number:
  US 20090161361A1
• Time in Patent Office: 1,259 Days
• Field of Search: 362/612, 362/613, 362/616, 362/628, 349/65, 385/31
• US Class Current: 362/616
• 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 light-emitting surface includes a plurality of discrete, substantially flat light-emitting illumination devices arranged in a tiled configuration. Each device has a light-emitting area and an unilluminated area, the light-emitting area of a first device occluding at least a portion of the unilluminated area of a second, adjacent device.

Claims

1. A light-emitting surface comprising a plurality of discrete, substantially flat light-emitting illumination devices arranged in a tiled, partially overlapping configuration to form a non-planar surface step on the light-emitting surface where overlap occurs, each device having a light-emitting area and an unilluminated area from which light is not emitted, the light-emitting area of a first device occluding at least a portion of the unilluminated area of a second, adjacent device, wherein each device comprises a light-guide element including spatially distinct in-coupling and out-coupling regions, whereby light entering the in-coupling region is substantially retained within the light-guide element for emission from the out-coupling region.

2. The light-emitting surface of claim 1 wherein each device comprises at least one LED, light emitted from the LED being coupled to the light-guide element in the in-coupling region.

3. The light-emitting surface of claim 2 wherein the LED is a Lambertian light source.

4. The light-emitting surface of claim 2 wherein each illumination device comprises a single LED.

5. The light-emitting surface of claim 2 wherein each illumination device comprises a plurality of LEDs.

6. The light-emitting surface of claim 5 wherein each illumination device comprises a plurality of adjacent LEDs.

7. The light-emitting surface of claim 1 wherein the light-emitting surface is flexible.

8. The light-emitting surface of claim 1 wherein the light-guide element further comprises a concentration region for directing a substantial fraction of multidirectional light received in the in-coupling region toward the out-coupling region.

9. The light-emitting surface of claim 8 wherein the light-guide element further comprises a propagation region through which light from the concentration region travels before reaching the out-coupling region.

10. The light-emitting surface of claim 1, further comprising a liquid crystal display panel comprising a plurality of pixels and disposed proximate and in front of the light-emitting illumination devices.

11. The light-emitting surface of claim 2, wherein the at least one LED is embedded within the in-coupling region.

12. The light-emitting surface of claim 2, wherein the at least one LED is a bare-die LED.

13. The light-emitting surface of claim 1, wherein each of the illumination devices is substantially notch-free such that the in-coupling and out-coupling regions of the device are substantially coplanar.

14. The light-emitting surface of claim 1, wherein at least a portion of the out-coupling region of the first device is disposed directly over at least a portion of the out-coupling region of the second device.

15. The light-emitting surface of claim 1, wherein a thickness of each device between the in-coupling region and the out-coupling region of the device is substantially constant.

16. The light-emitting surface of claim 1, wherein each illumination device comprises a region, disposed between the in-coupling and out-coupling regions and lacking a reflective coating, from which light is not emitted and in which light is confined only via total internal reflection.

17. A method of forming a light-emitting surface from a plurality of light-guide elements, the method comprising:

providing a first light-guide element comprising a first in-coupling region and a first out-coupling region spatially separated therefrom, whereby light entering the first in-coupling region is substantially retained within the first light-guide element for emission from the first out-coupling region; and

forming a non-planar surface step in the light-emitting surface by overlapping a portion of a second light-guide element above a portion of the first light-guide element to form an overlapping region, the second light-guide element comprising a second in-coupling region and a second out-coupling region spatially separated therefrom, whereby light entering the second in-coupling region is substantially retained within the second light-guide element for emission from the second out-coupling region,

wherein the overlapping region comprises at least the first in-coupling region and at least a portion of the second out-coupling region that completely occludes the first in-coupling region.

18. The method of claim 17, wherein light from the second out-coupling region fully occludes any unilluminated areas of the second light-guide element.

19. The method of claim 17, wherein the first light-guide element further comprises a first propagation region and a first concentration region, the second out-coupling region also occluding the first propagation region and the first concentration region.

20. The method of claim 17, wherein the first light-guide element is part of a first stripe of elements and the second light-guide element is part of a second stripe of elements.

21. The method of claim 20, wherein the first and second stripes of elements are asymmetric and arranged adjacently.

22. The method of claim 17, further comprising:

forming an additional non-planar surface step in the light-emitting surface by overlapping at least a portion of a third light-guide element above at least a portion of the second light-guide element to form a second overlapping region, the third light-guide element comprising a third in-coupling region and a third out-coupling region spatially separated therefrom, whereby light entering the third in-coupling region is substantially retained within the third light-guide element for emission from the third out-coupling region,

wherein the second overlapping region comprises at least a portion of the third out-coupling region.

23. The method of claim 17 further comprising illuminating each light-guide element using an illumination device comprising a socket formed by the union of a sub-assembly platform and the light-guide element, the socket containing a discrete light source coupled to the in-coupling region of the light-guide element.

24. The method of claim 23 wherein the discrete light source is an LED.

25. The method of claim 24 wherein the LED is a Lambertian light source.

26. The method of claim 23 wherein each illumination device comprises a single LED.

27. The method of claim 23 wherein each illumination device comprises a plurality of LEDs.

28. The method of claim 27 wherein each illumination device comprises a plurality of adjacent LEDs.

29. The method of claim 17 further comprising:

providing additional light-guide elements each comprising an in-coupling region and an out-coupling region spatially separated therefrom, whereby light entering an in-coupling region is substantially retained within the corresponding light-guide element for emission from the out-coupling region; and

forming additional non-planar surface steps in the light-emitting surface by overlapping a portion of each additional light-guide element above a portion of an adjacent light-guide element such that an out-coupling region occludes every in-coupling region not disposed at an edge of the planar light-emitting surface thereby formed.