Large area light source and large area luminaire

Patent metadata

Field	Value
Publication number	US-10677981-B2
Application number	US-201515755391-A
Country	US
Kind code	B2
Filing date	Aug 28, 2015
Priority date	Aug 28, 2015
Publication date	Jun 9, 2020
Grant date	Jun 9, 2020

Abstract

A light source (25) for emitting collimated light (29) in particular for a large area luminaire (21) comprises a light guide unit (43) comprising a plurality of light guide strips (91) configured for guiding light received at the at least one lateral coupling face (47), for example, by total internal reflection. The light guide strips comprise a plurality of localized light source regions (57) at a main front face (55A) for having light pass there through, wherein the light source regions (57) are provided along the light guide strip (91) within a non-source region (59). The light source (25) further comprising a plurality of light emitting units (41) for emitting light into the light guide strips (91) through respective portions of the at least one coupling face (47), and a collimation unit (45) extending along the main front face (55A) and comprising a plurality of collimating elements. Each collimating element comprises an input side and an output side, is optically associated to one of the plurality of light source regions (57), and is configured to receive light emerging from the associated light source region (57) at its input side and to emit collimated light (29) from a respective collimated light emitting region (61) formed at its output side.

First claim

The invention claimed is:

1. A light source for emitting collimated light, the light source comprising:
a light guide unit having a main front face, a main back face, and at least one lateral coupling face connecting the main front face and the main back face in a thickness direction, wherein
the light guide unit is configured for guiding light received at the at least one lateral coupling face by total internal reflection between the main front face and the main back face, and
the main front face comprises a plurality of localized light source regions for having light pass there through, wherein the light source regions are provided substantially uniformly distributed within and respectively surrounded by a non-source region,

a plurality of light emitting units configured to emit light into the light guide unit through each of the at least one coupling face; and
a collimation unit extending along the main front face and comprising a plurality of collimating elements, wherein each collimating element comprises an input side and an output side, is optically associated to one of the plurality of light source regions, and is configured to receive light emerging from the associated light source region at its input side, and to emit collimated light from a respective collimated light emitting region formed at its output side;
wherein the light source is configured to provide a light beam originating from each of the collimated light emitting regions that has a substantially round shape at a far field; and
wherein the collimated light from the plurality of collimating elements forms a low-diverging light beam, having a full-width beam angle less than or equal to 5°.

2. A light source for emitting collimated light, the light source comprising:
a light guide unit having a main front face, a main back face, and at least one lateral coupling face connecting the main front face and the main back face in a thickness direction, wherein
the light guide unit is configured for guiding light received at the at least one lateral coupling face by total internal reflection between the main front face and the main back face, and
the main front face comprises a plurality of localized light source regions for having light pass there through, wherein the light source regions are provided substantially uniformly distributed within and respectively surrounded by a non-source region,

a plurality of light emitting units configured to emit light into the light guide unit through each of the at least one coupling face;
a collimation unit extending along the main front face and comprising a plurality of collimating elements, wherein each collimating element comprises an input side and an output side, is optically associated to one of the plurality of light source regions, and is configured to receive light emerging from the associated light source region at its input side, and to emit collimated light from a respective collimated light emitting region formed at its output side; and
a plurality of reflective structures, each reflective structure being associated with a light source region;
wherein the light source is configured to provide a light beam originating from each of the collimated light emitting regions that has a substantially round shape at a far field; and
wherein a reflective structure of the plurality of reflective structures has a triangular cross section when looked at from the side and a round cross section when looked at from the respective collimating element and includes a planar reflecting side that has a shape of a half of an ellipse or of a half of a circle.

3. The light source of claim 2 , wherein the plurality of collimating elements comprises a plurality of compound parabolic concentrators or TIR lenses having their input sides lined up at the side of the main front face at the positions of the light source regions.

4. The light source of claim 3 , further comprising a plurality of down-conversion elements respectively associated with one of the plurality of compound parabolic concentrators or TIR lenses and positioned at the respective input sides, and wherein the plurality of compound parabolic concentrators or TIR lenses comprise respective dichroic reflective output sides reflective to the wavelength of the light emitted from the light emitting units.

5. The light source of claim 3 , wherein the plurality of collimating elements comprises a plurality of secondary lenses respectively associated with the compound parabolic concentrators or TIR lenses.

6. The light source of claim 2 , wherein the light source regions are provided in a substantially regular pattern or a regular grid structure over the non-source region in at least sections of the main front face, and/or
wherein the regular grid structure is based on one or more types of grid units, each type of grid unit having an essentially identical dimension, and/or wherein a shape of a grid unit comprises points at equal distances.

7. The light source of claim 2 , wherein the plurality of light source regions is distributed over the non-source region at equal distances.

8. The light source of claim 2 , wherein the light guide unit comprises two opposite lateral light coupling faces each being associated with a subgroup of light emitting units of the plurality of light emitting units for coupling counter-propagating light into the light guide unit.

9. The light source of claim 2 , wherein a continuous light emitting face is formed by the collimated light emitting regions, and the continuous light emitting face comprises non-emitting regions between the collimated light emitting regions, and the area ratio between the non-emitting regions and the collimated light emitting regions is essentially constant over the light emitting face of the light source.

10. The light source of claim 2 , wherein the distance between neighboring light source regions is in the range from 0.5 mm to 50 mm, and/or wherein the light source is configured such that the flux of light emitted from the light source regions is at least 10 times or at least 20 times or at least 50 times as much as any leakage flux of light through the non-source regions.

11. The light source of claim 2 , wherein the extension of the light guide unit in directions defined by the shape of the main front face is larger than the thickness of the light guide unit in the thickness direction.

12. The light source of claim 2 , wherein the light guide unit comprises a plurality of light guide strips, each light guide strip comprising at least one lateral coupling face section optically coupled to at least one of the plurality of light emitting units, and a subgroup of the plurality of light source regions is arranged linearly along the light guide strip at equal distances, wherein the pitch between neighboring light source regions along the strip is in the range from 1 mm to 50 mm or about 3 mm, and/or
wherein each light guide strip of the plurality of light guide strips has a rectangular cross-section with a thickness in the range from 0.1 mm to 5 mm, a lateral width in the range from 0.1 mm to 5 mm and a length in the range from 0.1 m to 2 m, and/or
wherein each light guide strip of the plurality of light guide strips is mounted to a substrate at the respective side of each light guide strip that is associated with the main back face of the light guide unit.

13. The light source of claim 2 , wherein the light source regions have a lateral extension in the range from 10 μm to 500 μm or about 100 μm, or
the light source regions have a lateral extension in the range up to 2 mm or up to 3 mm, and/or
the collimated light emitting regions have a lateral ext

Assignees

• Coelux Srl

Inventors

• Di Trapani Paolo
• Magatti Davide
• Lotti Antonio
• Krames Michael Ragan

Classifications

• F21Y2113/13

  comprising an assembly of point-like light sources · CPC title

• G02B6/0051

  Diffusing sheet or layer · CPC title

• G02B6/0078 Primary

  Side-by-side arrangements, e.g. for large area displays · CPC title

• F21S8/04

  intended only for mounting on a ceiling or the like overhead structures (F21S8/02 takes precedence; {details of ceiling bases F21V21/03}) · CPC title

• G02B6/0013

  Means for improving the coupling-in of light from the light source into the light guide (coupling light into light guides in general G02B6/42) · CPC title