Discrete lighting elements and planar assembly thereof
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.
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.