Light duct tee splitter

Patent metadata

Field	Value
Publication number	US-9360676-B2
Application number	US-201214009556-A
Country	US
Kind code	B2
Filing date	Apr 2, 2012
Priority date	Apr 8, 2011
Publication date	Jun 7, 2016
Grant date	Jun 7, 2016

Abstract

The disclosure generally relates to highly efficient light duct light splitters that are capable of splitting the light propagating within a light duct into two different ducts, with nearly 100 percent efficiency. In particular, the described light splitters are configured in a “Tee” shape with a reflective splitter element.

First claim

What is claimed is:

1. A light duct splitter, comprising: a first light conduit defining a light transport cavity capable of transporting light along a first propagation direction; a second light conduit defining a first light diversion cavity; a third light conduit defining a second light diversion cavity, the second and the third light conduit intersecting the first light conduit such that the light transport cavity and the first and the second light diversion cavities are contiguous; a light diverter, comprising: a first reflector disposed at a first diverter angle to the first propagation direction, the first reflector including a first edge and a second edge; and a second reflector disposed at a second diverter angle to the first propagation direction, the second reflector including a first edge and a second edge, the first reflector and the second reflector further disposed such that the first edge of the first reflector and the first edge of the second reflector intersect at an angle equal to the sum of the first diverter angle and the second diverter angle; wherein a first light ray propagating within a collimation angle of the first propagation direction that intersects the first reflector is diverted to a second light ray propagating within the collimation angle of a second propagation direction in the second light conduit, and wherein a third light ray propagating within the collimation angle of the first propagation direction that intersects the second reflector is diverted to a fourth light ray propagating within the collimation angle of a third propagation direction in the third light conduit, and wherein the first edge of the first reflector and the first edge of the second reflector intersect within a boxed region defined by an output cross section of the first light conduit, a first input cross section of the second light conduit, and a second input cross section of the third light conduit, and wherein at least one of the first and second input cross sections of the second light conduit and the third light conduit is smaller than the output cross section of the first light conduit.

2. The light duct splitter of claim 1 , wherein the first diverter angle and the second diverter angle each comprise an angle of approximately 45 degrees, and the second and third propagation directions are collinear and each perpendicular to the first propagation direction.

3. The light duct splitter of claim 1 , wherein each of the first, the second, and the third light conduits include a first, a second, and a third rectangular cross-section, respectively.

4. The light duct splitter of claim 3 , wherein at least two of the first, the second, and the third rectangular cross sections are the same.

5. The light duct splitter of claim 1 , wherein the intersection of the first edge of the first reflector and the first edge of the second reflector is disposed within a region bounded by the intersection of the light transport cavity and the first and the second light diversion cavities.

6. The light duct splitter of claim 1 , wherein the second edge of the first reflector is disposed adjacent an interior surface of the first light diversion cavity, and the second edge of the second reflector is disposed adjacent an interior surface of the second light diversion cavity.

7. The light duct splitter of claim 1 , wherein the first edge of the first reflector and the first edge of the second reflector intersect along a centerline of the light transport cavity.

8. The light duct splitter of claim 1 , wherein the collimation angle is between about 0 degrees and about 30 degrees.

9. The light duct splitter of claim 1 , wherein the collimation angle is between about 10 degrees and about 20 degrees.

10. The light duct splitter of claim 1 , wherein the collimation angle is about 18.4 degrees.

11. The light duct splitter of claim 1 , wherein the second edge of the first reflector is disposed in the first light diversion cavity outside of the boxed region, and the second edge of the second reflector is disposed in the second light diversion cavity outside of the boxed region.

12. The light duct splitter of claim 1 , wherein the light diverter comprises an isosceles-shaped triangular reflector having a base disposed perpendicular to the first propagation direction, a first side defined by the first reflector, a second side defined by the second reflector, and an apex defined by the intersection of the first reflector and the second reflector.

13. The light duct splitter of claim 1 , wherein at least two of the output cross section of the first light conduit, the first input cross section of the second light conduit, and the second input cross section of the third light conduit have the same dimensions.

14. The light duct splitter of claim 1 , wherein each of the first and the second diverter angles, and each of the first and the second reflectors can be independently adjusted so that a variable portion of light travelling though the light transport cavity can be diverted to the first and the second light diversion cavities.

15. The light duct splitter of claim 1 , wherein the first propagation direction is perpendicular to the second propagation direction and the third propagation direction.

16. The light duct splitter of claim 1 , wherein the second propagation direction is collinear with the third propagation direction.

17. The light duct splitter of claim 1 , wherein the second edge of the first reflector is disposed adjacent an interior surface of the first light diversion cavity outside of the region bounded by the intersection of the light transport cavity and the first and the second light diversion cavities, and
the second edge of the second reflector is disposed adjacent an interior surface of the second light diversion cavity outside of the region bounded by the intersection of the light transport cavity and the first and the second light diversion cavities.

18. The light duct splitter of claim 1 , wherein the interior surfaces of the first, second, and third light conduits comprise a material having a specular reflectivity for visible light of at least 98%.

Assignees

• Corrigan Thomas R J
• Freier David G
• 3M Innovative Properties Co

Inventors

• Corrigan Thomas R J
• Freier David G

Classifications

• G02B27/14 Primary

  operating by reflection only · CPC title

• G02B6/0096

  the lights guides being of the hollow type · CPC title

• G02B6/0018

  Redirecting means on the surface of the light guide · CPC title

• G02B6/2817

  using reflective elements to split or combine optical signals · CPC title

• F21V7/24

  characterised by the material · CPC title