Shaped light guide illumination devices

Patent metadata

Field	Value
Publication number	US-10267972-B2
Application number	US-201715793755-A
Country	US
Kind code	B2
Filing date	Oct 25, 2017
Priority date	Oct 25, 2016
Publication date	Apr 23, 2019
Grant date	Apr 23, 2019

Abstract

A shaped illumination panel having a broad-area sheet-form configuration and including a flexible sheet of an optically transmissive material and one or more light sources optically coupled to an edge of the flexible sheet. The flexible sheet may include forward-deflecting or forward-scattering elements configured to extract light from one location of the flexible sheet and direct the extracted light to a second location of the flexible sheet where the extracted light can be transversely propagated through and reemitted from the flexible sheet.

First claim

What is claimed is:

1. An edge-lit illumination device, comprising:
a flexible sheet of an optically transmissive material having at least one curvature about an axis and defining a concave broad-area surface, an opposing convex broad-area surface extending parallel to said concave broad-area surface, a first edge, and an opposing second edge;
a LED source optically coupled to said first edge;
a plurality of forward-deflecting or forward-scattering light extraction elements formed in either one of the concave and convex broad-area surfaces, said light extraction elements being discrete surface relief features distributed over a broad area of said flexible sheet according to a two-dimensional pattern and separated from each other by smooth surface portions;
a reflector conformably positioned on a convex side of said flexible sheet, and
light scattering particles disposed between said flexible sheet and said reflector;
wherein said flexible sheet is configured to guide light from said first edge toward said second edge in response to optical transmission and a total internal reflection, wherein at least one of said light extraction elements is configured to extract light from said concave broad-area surface at a first location of said flexible sheet and direct at least a portion of the extracted light toward a second location of the flexible sheet that is distant from said first location, wherein said flexible sheet is configured to receive the extracted light on said concave broad-area surface at said second location and propagate the received light transversely through said flexible sheet to exit from said convex broad-area surface, and wherein the reflector is configured to reflect the extracted light toward said flexible sheet such that at least a portion of the extracted light is re-emitted from said second location away from said concave broad-area surface.

2. An edge-lit illumination device as recited in claim 1 , comprising an elongated heat dissipating structural element extending parallel to said first edge, and comprising an opaque elongated housing at least partially enclosing said LED source, and wherein said LED source is attached to said elongated heat dissipating structural element.

3. An edge-lit illumination device as recited in claim 1 , wherein said forward-deflecting or forward-scattering light extraction elements are formed in both said concave and convex broad-area surfaces.

4. An edge-lit illumination device as recited in claim 1 , wherein said LED source is optically coupled to said flexible sheet using a layer of an index matched optically transmissive material.

5. An edge-lit illumination device as recited in claim 1 , wherein said flexible sheet is characterized by a bend angle of greater than 20° and at most 90°.

6. An edge-lit illumination device as recited in claim 1 , wherein said flexible sheet is characterized by a bend angle of greater than 90° and less than 180°.

7. An edge-lit illumination device as recited in claim 1 , wherein said flexible sheet has the shape of a thin curved wedge.

8. An edge-lit illumination device as recited in claim 1 , wherein said sheet is configured to emit light with a cutoff angle of at least 10°.

9. An edge-lit illumination device as recited in claim 1 , wherein at least one of said light extraction elements comprises a prismatic groove having a low-angle refractive facet.

10. An edge-lit illumination device as recited in claim 1 , wherein at least one of said light extraction elements comprises a surface relief feature formed by a forward-scattering material.

11. An edge-lit illumination device as recited in claim 10 , wherein said surface relief feature is configured to forward scatter at least 20% and backscatter at least 20% of incident light energy.

12. An edge-lit illumination device as recited in claim 10 , wherein said forward-scattering material is configured to forward scatter at least 20% and backscatter at least 20% of incident light energy at a layer thickness equal to an average thickness of said surface relief feature.

13. An edge-lit illumination device as recited in claim 1 , wherein said flexible sheet comprises two symmetrical sections cooperatively forming a trough shape.

14. An edge-lit illumination device as recited in claim 1 , comprising an index-matched light coupling layer between said LED source and said first edge, wherein at least a portion of light coupled through said first edge exits from said concave broad-area surface near said first edge and is received by said flexible sheet near said second edge.

15. An edge-lit illumination device as recited in claim 1 , wherein a radius R C of curvature of said flexible sheet is less than 3 times a length L of a curved profile of said flexible sheet in a cross-section perpendicular to said first edge.

16. An edge-lit illumination device as recited in claim 1 , wherein said second edge is configured to emit light to a range of directions, wherein a prevailing direction of light emitted from said second edge is different from a prevailing direction of light emitted by said LED source.

17. An edge-lit illumination device as recited in claim 1 , wherein at least one of said light extraction elements has a total volume between 1000 cubic micrometers and 500000 cubic micrometers, a size between 20 to 200 micrometers, and an irregular shape.

18. An edge-lit illumination device as recited in claim 1 , wherein an angle α p of a peak surface emission from said light guide measured near said first edge and a bend angle β of said light guide are bounded by the following relation: 90°−α p <2β.

19. An edge-lit illumination device, comprising:
a flexible sheet of an optically transmissive material having at least one curvature about an axis and defining a concave broad-area surface, an opposing convex broad-area surface extending parallel to said concave broad-area surface, a first edge, and an opposing second edge;
an elongated heat dissipating structural element extending parallel to said first edge;
a LED source attached to said elongated heat dissipating structural element and optically coupled to said first edge;
a plurality of forward-deflecting or forward-scattering light extraction elements formed in either one of the concave and convex broad-area surfaces, said light extraction elements being discrete surface relief features distributed over a broad area of said flexible sheet according to a two-dimensional pattern and separated from each other by smooth surface portions;
an opaque elongated housing at least partially enclosing said LED source;
wherein said flexible sheet is configured to guide light from said first edge toward said second edge in response to optical transmission and a total internal reflection, wherein at least one of said light extraction elements is configured to extract light from said concave broad-area surface at a first location of said flexible sheet and direct at least a portion of the extracted light toward a second location of the flexible sheet that is distant from said first location, wherein said flexible sheet is configured to receive the extracted light on said concave broad-area surface at said second location and propagate the received light transversely through said flexible sheet to exit from said convex broad-area surface.

20. An edge-lit illumination device as recited in claim 19 , comprising a reflector conformably positioned on a convex side of said sheet and configured to reflect the extracted light toward said flexible sheet such that at least a

Assignees

• Vasylyev Sergiy
• Svv Tech Innovations Inc

Inventors

• Vasylyev Sergiy

Classifications

• G02B6/0053

  Prismatic sheet or layer; Brightness enhancement element, sheet or layer · CPC title

• G09F13/18

  Edge-illuminated signs · CPC title

• G02B6/002 Primary

  by shaping at least a portion of the light guide, e.g. with collimating, focussing or diverging surfaces · CPC title

• G02B6/0028

  Light guide, e.g. taper · CPC title

• G02B6/0055

  Reflecting element, sheet or layer · CPC title