Lightguide and light source incorporating same

Patent metadata

Field	Value
Publication number	US-9989691-B2
Application number	US-201013379829-A
Country	US
Kind code	B2
Filing date	Jun 25, 2010
Priority date	Jun 29, 2009
Publication date	Jun 5, 2018
Grant date	Jun 5, 2018

Abstract

A lightguide ( 100 ) is disclosed. The lightguide includes a plurality of light extractors ( 120 - 123 ). Each light extractor is designed primarily to extract light that propagates within the lightguide and is incident on the light extractor from a first direction and reflect light that propagates within the lightguide and is incident on the light extractor from a second direction different than the first direction, toward another light extractor, where the other light extractor extracts the reflected light.

First claim

What is claimed is:

1. A lightguide extending along a light emitting surface having a surface normal thereof, the lightguide comprising a plurality of light extractors configured to extract light out of the light emitting surface, each light extractor comprising:
a first portion tilted with respect to the light emitting surface for light extraction; and
a second portion having an associated surface substantially perpendicular to the light emitting surface to reflect light toward the first portion of at least one other light extractor,
wherein the lightguide further comprises an edge to receive an incident light propagating within the lightguide along a general direction, and one or more lamps disposed along the edge to emit the incident light, and
wherein the plurality of light extractors comprises a first plurality of light extractors and a second plurality of light extractors, the first plurality of light extractors are oriented to have the first portions to face the one or more lamps to receive light therefrom and with a twisted angle with respect to the received light from the lamps such that a general emission direction of light extracted by the first portions is tilted toward a side of the lightguide and has an angle relative to the surface normal of the light emitting surface in a range from about 10 degrees to about 40 degrees, and the second plurality of light extractors are oriented to have the associated surfaces of the second portions to face the one or more lamps to reflect light toward the first portion of at least one another light extractor for light extraction.

2. The lightguide of claim 1 , wherein the light extractors in the plurality of light extractors are depressions.

3. The lightguide of claim 1 , wherein the light extractors in the plurality of light extractors form a regular array.

4. The lightguide of claim 1 , wherein the first portion of each light extractor comprises a planar portion, or is piecewise planar.

5. The lightguide of claim 1 , wherein the first portion of each light extractor comprises a curved portion, or is piecewise curved.

6. The lightguide of claim 1 , wherein the first portion of each light extractor is aspheric.

7. The lightguide of claim 1 , wherein
the first portions of the first plurality of light extractors face a first incident light from a first edge of the lightguide and the second portions of the first plurality of light extractors face away from the first incident light from the first edge; and
the first portions of the second plurality of light extractors face a second incident from a second edge of the lightguide and the second portions of the second plurality of light extractors face away from the second incident light from the second edge.

8. The lightguide of claim 7 , wherein:
the second portions of the first plurality of light extractors face the second incident light from the second edge of the lightguide; and
the second portions of the second plurality of light extractors face the first incident light from the first edge of the lightguide.

9. The lightguide of claim 7 , wherein the first and second pluralities of light extractors are mirror images of each other.

10. The lightguide of claim 7 , wherein the first and second edges are opposite to each other, and the associated surfaces of the second portions are twisted neither parallel nor perpendicular to either the first edge or the second edge.

11. The lightguide of claim 1 comprising:
a structured surface opposite to the light emitting surface comprising the plurality of light extractors.

12. The lightguide of claim 11 , wherein the light extractors in the plurality of light extractors form depressions in the structured bottom surface.

13. A light source comprising:
the lightguide of claim 11 ;
a back reflector disposed proximate the structured surface of the lightguide; and
the one or more lamps disposed along the edge of the lightguide.

14. A rear window assembly or a trunk lid of a motor vehicle comprising the light source of claim 11 .

15. The lightguide of claim 1 , wherein each light extractor comprises a third portion not designed to either extract light or reflect light toward the first portion of at least one other light extractor for light extraction.

16. A light source comprising:
a lightguide extending along a light emitting surface having a surface normal thereof, the lightguide comprising a plurality of light extractors configured to extract light out of the light emitting surface, each light extractor comprising a first portion tilted with respect to the light emitting surface to extract light from the lightguide and a second portion having an associated surface substantially perpendicular to the light emitting surface to reflect light toward the first portion of another light extractor for extraction from the lightguide;
a first lamp disposed along a first edge of the lightguide to emit light entering the lightguide along a first general direction; and
a second lamp disposed along a second edge of the lightguide different than the first edge to emit light entering the lightguide along a second general direction, wherein the plurality of light extractors comprises:
a first plurality of light extractors being oriented to have the first portions thereof to face the first lamp to receive light therefrom and with a twisted angle with respect to the received light from the first lamp such that a general emission direction of light extracted by the first portions is tilted toward a side of the lightguide and has an angle relative to the surface normal of the light emitting surface in a range from about 10 degrees to about 40 degrees, and have the associated surfaces of the second portions thereof to face the second lamp to reflect light that is emitted by the second lamp toward the first portion of at least one other light extractor for extraction from the lightguide; and
a second plurality of light extractors different from the first plurality of light extractors, the second plurality of light extractors being oriented to have the first portions thereof to face the second lamp to receive light therefrom and with a twisted angle with respect to the received light from the second lamp such that a general emission direction of light extracted by the first portions is tilted toward the same side of the lightguide and has an angle relative to the surface normal of the light emitting surface in a range from about 10 degrees to about 40 degrees, and have the associated surfaces of the second portions thereof to face the first lamp to reflect light that is emitted by the first lamp toward the first portion of at least one other light extractor for extraction from the lightguide.

17. The light source of claim 16 , wherein the first and second edges are opposite to each other, and the associated surfaces of the second portions are twisted neither parallel nor perpendicular to either the first edge or the second edge.

Assignees

• Ender David A
• 3M Innovative Properties Co

Inventors

• Ender David A

Classifications

• F21S43/249

  with two or more light sources being coupled into the light guide · CPC title

• F21S43/245

  emitting light from one or more of its major surfaces · CPC title

• F21S43/239

  plate-shaped · CPC title

• F21S43/14

  Light emitting diodes [LED] · CPC title

• G02B6/0036 Primary

  2-D arrangement of prisms, protrusions, indentations or roughened surfaces · CPC title