BACKLIGHT ASYMMETRIC LIGHT INPUT WEDGE

• US 20110099864A1
• Filed: 01/14/2011
• Published: 05/05/2011
• Est. Priority Date: 05/24/2006
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Destain, Patrick R., Meis, Michael A., Bryan, William J., Schultz, John C.
• Granted Patent: US 8,059,933 B2
• Time in Patent Office: Days
• US Class Current: 40/582
• CPC Class Codes: G02B 6/0028 Light guide, e.g. taper
• CPC Class Codes: G02B 6/0031 Reflecting element, sheet or layer
• CPC Class Codes: G02B 6/0043 provided on the surface of the light guide
• CPC Class Codes: G02B 6/0046 Tapered light guide, e.g. wedge-shaped light guide
• CPC Class Codes: G02B 6/0055 Reflecting element, sheet or layer

Abstract

A backlight is disclosed and includes a visible light transmissive body primarily propagating light by TIR with a light input surface and a light output surface and a light guide portion and a light input portion. The light guide portion has a light reflection surface and a light emission surface. The light input portion has opposing side surfaces that are not parallel. One of the opposing surfaces is co-planar with either the light emission surface or the light reflection surface. A light source is disposed adjacent to the light input surface. The light source emits light into the light input portion. A reflective layer is disposed adjacent to or on the opposing side surfaces.

Claims

1. An illumination assembly, comprising:

an asymmetric diverging wedge defined by a narrow end surface and a wide end surface, and opposing side surfaces that are not parallel and extend between the narrow end and the wide end;

a solid state light source extending into the asymmetric diverging wedge at the narrow end surface, the solid state light source emitting light into the narrow end surface of the diverging wedge;

a light guide optically coupled to the wide end surface, the light guide having a light reflection surface and a light emission surface, and one of the opposing side surfaces being co-planar from the narrow end surface to the wide end surface with either the light emission surface or the light reflection surface; and

a reflective layer disposed parallel with and adjacent to or on each of the opposing side surfaces,

wherein the diverging wedge and the light guide form a unitary body, and

wherein the light emission surface functions as a luminaire.

2. The illumination assembly of claim 1, further comprising a reflective layer on the light reflection surface, wherein the reflective layer includes a plurality of light extraction elements.

3. The illumination assembly of claim 1, wherein the solid state light source comprises a light emitting diode.

4. The illumination assembly of claim 1, wherein the light emission surface and the light reflection surface are parallel.

5. The illumination assembly of claim 1, wherein the light emission surface and the light reflection surface are non-parallel.

6. An illumination assembly, comprising:

an asymmetric diverging wedge defined by a narrow end surface and a wide end surface, and opposing side surfaces that are not parallel and extend between the narrow end and the wide end;

a solid state light source extending into the asymmetric diverging wedge at the narrow end surface, the solid state light source emitting light into the narrow end surface of the diverging wedge;

a light guide optically coupled to the wide end surface, the light guide having a light reflection surface and a light emission surface, and one of the opposing side surfaces being co-planar from the narrow end surface to the wide end surface with either the light emission surface or the light reflection surface; and

a reflective layer disposed parallel with and adjacent to or on each of the opposing side surfaces,

wherein the diverging wedge and the light guide are separate bodies having an interface surface where the light guide is optically coupled to the diverging wedge, and

wherein the light emission surface functions as a luminaire.

7. The illumination assembly of claim 6, further comprising a reflective layer on the light reflection surface, wherein the reflective layer includes a plurality of light extraction elements.

8. The illumination assembly of claim 6, wherein the solid state light source comprises a light emitting diode.

9. The illumination assembly of claim 6, wherein the light emission surface and the light reflection surface are parallel.

10. The illumination assembly of claim 6, wherein the light emission surface and the light reflection surface are non-parallel.

11. A backlight assembly for a sign, comprising:

an asymmetric diverging wedge defined by a narrow end surface and a wide end surface, and opposing side surfaces that are not parallel and extend between the narrow end and the wide end;

a solid state light source extending into the asymmetric diverging wedge at the narrow end surface, the solid state light source emitting light into the narrow end surface of the diverging wedge;

a light guide optically coupled to the wide end surface, the light guide having a light reflection surface and a light emission surface, and one of the opposing side surfaces being co-planar from the narrow end surface to the wide end surface with either the light emission surface or the light reflection surface;

a reflective layer disposed parallel with and adjacent to or on each of the opposing side surfaces; and

a graphic film positioned adjacent the light emission surface, wherein the light emission surface provides backlighting for the graphic film.

12. The backlight assembly of claim 11, further comprising a reflective layer on the light reflection surface, wherein the reflective layer includes a plurality of light extraction elements.

13. The backlight assembly of claim 11, wherein the solid state light source comprises a light emitting diode.

14. The backlight assembly of claim 11, wherein the light emission surface and the light reflection surface are parallel.

15. The backlight assembly of claim 11, wherein the light emission surface and the light reflection surface are non-parallel.