STITCHES ELIMINATION STRUCTURE AND METHOD TO PROVIDE THE SAME

• US 20090162015A1
• Filed: 11/26/2008
• Published: 06/25/2009
• Est. Priority Date: 12/19/2007
• Status: Active Grant

• Current Assignee: Oree Advanced Illumination Solutions Ltd.
• Original Assignee: Oree, Advanced Illumination Solutions Inc.
• Inventors: Zimmermann, Micha, Meir, Noam, Shani, Yosi
• Granted Patent: US 7,907,804 B2
• Time in Patent Office: Days
• US Class Current: 385/49
• 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 light-guide element comprising a first out-coupling region; and

a second light-guide element comprising a second out-coupling region, at least a portion of the second out-coupling region overlapping at least a portion of the first out-coupling to define an overlapping region having an area,

wherein the overlapping region emits a substantially uniform light output power over the area.

2. The planar illumination area of claim 1, wherein the light output power of the overlapping region differs from the light output power of the first and second out-coupling regions by no more than 10%.

3. The planar illumination area of claim 2, wherein the change in light output power between the overlapping region and the first and second out-coupling regions is gradual.

4. The planar illumination area of claim 1, wherein the first out-coupling region comprises light-scattering elements therein and the first and second out-coupling regions overlap only partially, a density of the light-scattering elements outside the overlapping region being greater than a density of the light-scattering elements inside the overlapping region.

5. The planar illumination area of claim 4, wherein the density of the light-scattering elements inside the overlapping region decreases along one direction.

6. The planar illumination area of claim 1, wherein the second out-coupling region is transparent in the overlapping region.

7. The planar illumination area of claim 6, wherein, in the overlapping region, light emitted from the first out-coupling region passes through the second out-coupling region.

8. The planar illumination area of claim 1, wherein the first and second out-coupling regions overlap only partially, and further comprising a third light-guide element comprising a third out-coupling region, a portion of the third out-coupling region overlapping a second portion of the second out-coupling region to define a second overlapping region having a second area, wherein the second overlapping region emits a substantially uniform light output power over the second area.

9. The planar illumination area of claim 1, wherein the first light-guide element comprises a non-vertical sidewall and the second light-guide element comprises a second, complementary non-vertical sidewall within the overlapping region.

10. The planar illumination area of claim 9, wherein a top surface of the planar illumination area is substantially flat.

11. The planar illumination area of claim 1, further comprising additional light-guide elements forming, with the first and second light-guide elements, an array extending in first and second directions, wherein the light-guide elements overlap in the first direction and do not overlap in the second direction.

12. The planar illumination area of claim 1, further comprising additional light-guide elements forming, with the first and second light-guide elements, an array extending in first and second directions, wherein the light-guide elements overlap in the first and second directions.

13. The planar illumination area of claim 1, wherein the overlapping region comprises a light-absorbing material.

14. A method of forming a planar illumination area, the method comprising:

providing a first light-guide element comprising a first out-coupling region; and

overlapping at least a portion of the first light-guide element with a second light-guide element comprising a second out-coupling region, thereby forming an overlapping region comprising at least a portion of the first out-coupling region and the second out-coupling region,

wherein the overlapping region emits a substantially uniform light output power.

15. A planar illumination area comprising:

a first light-guide element comprising a first sidewall;

a second light-guide element comprising a second sidewall; and

an index-matching material covering the first and second sidewalls, an index of refraction of the index-matching material being approximately equal to an index of refraction of at least one of the first light-guide element or the second light-guide element.

16. The planar illumination area of claim 15, wherein the second sidewall is adjacent to the first sidewall and the index-matching material is located between the first and second sidewalls.

17. The planar illumination of claim 15, wherein the first and second light-guide elements overlap, the index-matching material covering the first and second light-guide elements to create a smooth surface thereover.

18. A planar illumination area comprising:

a first light-guide element comprising a first polished sidewall; and

a second light-guide element comprising a second polished sidewall, the second polished sidewall being adjacent to the first polished sidewall,

wherein the second light-guide element receives light from the first light-guide element through the first polished sidewall and the second polished sidewall.

19. The planar illumination area of claim 18, further comprising an index-matching material located between the first and second sidewalls, an index of refraction of the index-matching material being approximately equal to an index of refraction of at least one of the first light-guide element or the second light-guide element.