Enhanced light fixture

• US 7,431,489 B2
• Filed: 11/17/2005
• Issued: 10/07/2008
• Est. Priority Date: 11/17/2004
• Status: Active Grant

• Current Assignee: Fusion Optix Inc.
• Original Assignee: Fusion Optix Inc.
• Inventors: Yeo, Terence E., Coleman, Zane A.
• Primary Examiner(s): Choi; Jacob Y
• Application Number:
  US11/282,551
• Publication Number:
  US 20060227546A1
• Time in Patent Office: 1,055 Days
• Field of Search: 362/606, 362/607, 362/609, 362/610, 362/614, 362/613, 362/617, 362/618, 362/620, 362/632, 362/615, 362/616, 349/62, 349/63, 349/65
• US Class Current: 362/606
• CPC Class Codes: F21S 6/00 Lighting devices intended to be free-standing F21S9/00, F21S10/00, F21S13/12 take precedence lighting devices specially adapted to be transported from place to place, e.g. lighting devices carried on wheeled supports F21L; details of supports for lighting devices F21V21/00
• CPC Class Codes: F21S 8/08 with a standard F21S6/00 takes precedence
• CPC Class Codes: F21V 1/00 Shades for light sources , i.e. lampshades for table, floor, wall or ceiling lamps
• CPC Class Codes: F21V 2200/10 of light guides of the optical fibres type
• CPC Class Codes: F21V 2200/20 of light guides of a generally planar shape
• CPC Class Codes: F21V 3/049 Patterns or structured surfaces for diffusing light, e.g. frosted surfaces
• CPC Class Codes: F21W 2131/103 of streets or roads
• CPC Class Codes: F21Y 2105/00 Planar light sources
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: G02B 27/0988 Diaphragms, spatial filters, masks for removing or filtering a part of the beam
• CPC Class Codes: G02B 5/0242 by means of dispersed particles
• CPC Class Codes: G02B 5/0257 creating an anisotropic diffusion characteristic, i.e. distributing output differently in two perpendicular axes
• CPC Class Codes: G02B 5/0284 used in reflection
• CPC Class Codes: G02B 6/0041 provided in the bulk of the light guide
• CPC Class Codes: G02B 6/0051 Diffusing sheet or layer
• CPC Class Codes: G02B 6/0055 Reflecting element, sheet or layer

Abstract

An enhanced light fixture containing a volumetric, anisotropic diffuser to control the spatial luminance uniformity and angular spread of light from the light fixture is disclosed. The anisotropic diffuser provides increased spatial luminance uniformity and efficient control over the illuminance such that power reductions, reduced cost or reduced size may be achieved. The anisotropic diffuser contains one or more regions of asymmetrically shaped light scattering particles. The spread of illumination of light from a light emitting source can be efficiently controlled by using a thin, low cost, volumetric, asymmetric diffuser to direct the light in the desired direction. This allows the reduction in number of light sources, a reduction in power requirements, or a more tailored illumination. When the anisotropic diffuser is used in combination with a waveguide to extract light, the light is efficiently coupled out of the waveguide in a thin, planar surface. This transmissive diffuser can be coupled to a reflecting element such that the resulting combination is a light reflecting element with a desired asymmetric light scattering profile.

Claims

1. A light ficture comprising:

a) at least one light emitting source;

b) a light transmitting region comprising a first anisotropic scattering region comprising a first continuous phase material of refractive index n_c1 and a first dispersed phase material of refractive index n_d1 wherein |n_c1−

n_d1|>

0.001 and one or more of the first dispersed phase domains are ellipsoidal in shape disposed to receive light from the light emitting source and scatter light to provide illumination;

c) a housing providing support for the source and light transmitting region; and

d) a substantially planar first light output surface

wherein the first dispersed phase domains are arranged substantially parallel to the first light output surface and the anisotropic light scattering region scatters a predetermined first portion of light from the light emitting source toward the first light output surface and a second predetermined portion of light away from the first light output surface.

2. The light fixture of claim 1 wherein the light fixture emits light in a first light output profile when the anisotropic light scattering element is in a first orientaion and can be re-configured after installation to emit light in a second light output profile different than the first light output profile by rotating the anisotropic light scattering region to a second orientation.

3. The light fixture of claim 1 wherein the shapes of the first dispersed phase domains vary spatially in the anisotropic light scattering region.

4. The light fixture of claim 1 wherein the light fixture is a direct and indirect illumination type.

5. The light fixture of claim 4 wherein the spatial luminance uniformity of apparatus is greater than or equal to 70%.

6. The light fixture of claim 4 wherein the apparatus emits anisotropic light radiation.

7. The light fixture of claim 4 wherein the light source is selected from a group consisting of:

fluorescent lamp, cylindrical cold-cathode fluorescent lamp, flat fluorescent lamp, light emitting diode, organic light emitting diode, field emissive lamp, gas discharge lamp, neon lamp, filament lamp, incandescent lamp, electroluminescent lamp, radiofluorescent lamp, halogen lamp, incandescent lamp, mercury vapor lamp, sodium vapor lamp, high pressure sodium lamp, metal halide lamp, tungsten lamp, carbon arc lamp, electroluminescent lamp, laser, photonic bandgap based light source, quantum dot based light source.

8. The light fixture of claim 7 containing more than one light emitting source with the light emitting sources arranged in an array.

9. The light fixture of claim 8 wherein the cross-section profile of the light source is substantially longer in the x direction than the y direction.

10. The light fixture of claim 8 wherein the array is a linear array.

11. The light fixture of claim 4 further comprising a reflective element.

12. The light fixture of claim 4 wherein the first dispersed phase domains are gaseous.

13. The light fixture of claim 4 wherein the concentration of the first dispersed phase domains varies spatially in the fist anisotropic light scattering region.

14. The light fixture of claim 4 wherein the sizes of the first dispersed phase domains vary spatially in the first anisotropic light scattering region.

15. The light fixture of claim 4 wherein the orientation of the first dispersed phase domains varies spatially in the first anisotropic light scattering region.

16. The light fixture of claim 4 wherein the light transmitting region further comprises substantially spherical particles.

17. The light fixture of claim 4 wherein the light transmitting region further comprises a surface relief light re-directing feature.

18. The light fixture of claim 17 wherein the surface relief light re-directing feature is a collimating feature.

19. The light fixture of claim 18 wherein the surface relief light collimating feature is a linear array of prisms.

20. The light fixture of claim 18 wherein the surface relief light re-directing feature is an array of concave surface relief patterns on a light transmitting material.

21. The light fixture of claim 18, wherein the surface relief light re-directing feature is an array of convex surface relief patterns comprising a coating containing substantially spherical micro-bodies.

22. The light fixture of claim 17, wherein the surface relief light re-directing feature increases the full angular width at half maximum illuminance in at least one direction.

23. The light fixture of claim 1 wherein the light transmitting region further comprises a second anisotropic light scattering region disposed to receive light from the first anisotropic light scattering region and provide illumination comprising a second continuous phase material of refractive index n_c2 and a second dispersed phase material of refractive index n_d2 wherein |n_c2−

n_d2|>

0.001 and one or more of the second dispersed phase domains are ellipsidal in shape and oriented substantially orthogonal to the first disersed phase domains.

24. The light fixture of claim 23, wherein the first anisotropic light scattering region is separated from the second anisotropic light scattering region by a substantially non-scattering region.

25. The light fixture of claim 1 containing refractive materials with one or more refractive indexes selected from a group consisting of:

n_dx1≠

n_dy1, n_dx1≠

n_dz1, n_dy1≠

n_dz1, n_cx1≠

n_cy1, n_cx1≠

n_cz1, n_cy1≠

n_cz1 where n_dx1, n_dy1, n_dz1 are refractive indexes of the dispersed phase material in the x, y, and z direction, respectively, and n_cx1, n_cy1, n_cz1 are the refractive indexed of the first continuous phase material in the x, y, and z directions, respectively and x, y, and z are three mutually orthogonal directions.

26. The light fixture of claim 1 further comprising a substantially non-scatterin light transmitting region of refractive index n_t wherein a first set of light rays from the light emitting source totally internally reflects within the light tranmitting region.

27. The light fixture of claim 26, wherein the first anisotropic light scattering region is disposed such that one or more first dispersed phase domains scatters incident light into an angle θ

such that

28. The light fixture of claim 1 further comprising first surface normal to the first light output surface at angle α

within the light transmitting region and a second light output surface with a second surface normal angle β

within the light transmitting region wherein light exits the light fixture through the first and second surfaces to provide illumination wherein α

≠

β

.

29. The light fixture of claim 28, wherein 0°

≦

|α

−

β

|≦

180°

.

30. The light fixture of claim 1 wherein the light fixture emits light in a first light output profile when the anisotrpic light scattering element is in a first position and can be re-configured by the user of the light fixture to emit light in a second light output profile different than the first light output profile by translating the spatial position of the anisotropic light scattering region to a second position.