Solid state light assembly having light sources in a ring

• US 8,419,218 B2
• Filed: 06/29/2011
• Issued: 04/16/2013
• Est. Priority Date: 06/24/2009
• Status: Active Grant

• Current Assignee: Elumigen Llc
• Original Assignee: Elumigen Llc
• Inventors: Dassanayake, Mahendra, De Mel, Srini, Samarabandu, Jagath
• Primary Examiner(s): Neils, Peggy A.
• Application Number:
  US13/172,236
• Publication Number:
  US 20110255282A1
• Time in Patent Office: 657 Days
• Field of Search: 362/294, 362/373, 362/249.02, 362/231, 362/346, 362/240, 362/241
• US Class Current: 362/249.02
• CPC Class Codes: F21K 9/232 specially adapted for generating an essentially omnidirectional light distribution, e.g. with a glass bulb
• CPC Class Codes: F21K 9/64 using wavelength conversion means distinct or spaced from the light-generating element, e.g. a remote phosphor layer
• CPC Class Codes: F21V 13/08 the elements being filters or photoluminescent elements and reflectors
• CPC Class Codes: F21V 23/009 the casing being inside the housing of the lighting device
• CPC Class Codes: F21V 29/70 characterised by passive heat-dissipating elements, e.g. heat-sinks
• CPC Class Codes: F21V 29/75 with fins or blades having different shapes, thicknesses or spacing
• CPC Class Codes: F21V 29/767 the planes containing the fins or blades having directions perpendicular to the light emitting axis
• CPC Class Codes: F21V 3/00 Globes; Bowls; Cover glasses with refracting properties F21V5/00; with reflecting properties F21V7/00; characterised by cooling arrangements F21V29/506
• CPC Class Codes: F21V 3/02 characterised by the shape
• CPC Class Codes: F21V 7/0025 Combination of two or more reflectors for a single light source array of reflectors for a cluster of light sources F21V7/0083
• CPC Class Codes: F21V 7/06 with parabolic curvature
• CPC Class Codes: F21V 7/08 with elliptical curvature
• CPC Class Codes: F21V 7/28 characterised by coatings
• CPC Class Codes: F21V 9/06 for filtering out ultraviolet radiation
• CPC Class Codes: F21V 9/08 for producing coloured light, e.g. monochromatic; for reducing intensity of light with provision for controlling the colour F21V9/40
• CPC Class Codes: F21V 9/30 Elements containing photoluminescent material distinct from or spaced from the light source shades F21V1/17; globes, bowls or cover glasses F21V3/08, F21V3/12; refractors F21V5/10; reflectors F21V7/26, F21V7/30; elements with provision for controlling the spectral properties or intensity F21V9/40
• CPC Class Codes: F21V 9/35 at focal points, e.g. of refractors, lenses, reflectors or arrays of light sources
• CPC Class Codes: F21Y 2103/33 annular
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]

Abstract

A light assembly having an axis of symmetry that includes an enclosure comprising at least a base and a cover coupled to the base. The light assembly also includes a plurality of light sources disposed on a circuit board within the enclosure in a first ring having a center point aligned with the axis of symmetry. The light assembly also includes a reflector that has a first focal point within the cover and a plurality of second focal points disposed in a second ring coincident with the first ring.

Claims

1. A light assembly having an axis of symmetry comprising:

an enclosure comprising at least a base and a cover coupled to the base;

a plurality of light-emitting diodes disposed on a circuit board within the enclosure, said plurality of light emitting diodes disposed in a first ring having a ring center point aligned with the axis of symmetry; and

a partial continuous rotated ellipsoidal reflector having a first focal point within the cover and a plurality of second focal points disposed in a continuous second ring coincident with the first ring, said reflector formed by rotating a major axis of an ellipse around the second ring while continually intersecting the first focal point, said reflector reflecting low angle light from the plurality of light-emitting diodes toward the first focal point then through the cover.

2. A light assembly as recited in claim 1 wherein the first focal point is coincident with a cover center point of the cover.

3. A light assembly as recited in claim 1 wherein the circuit board is disposed on a plane perpendicular to the axis of symmetry of the light assembly.

4. A light assembly as recited in claim 1 wherein the enclosure comprises a housing, said housing disposed between the base and the cover, wherein the housing comprises the reflector.

5. A light assembly as recited in claim 4 wherein the reflector comprises an offset ellipsoidal reflector portion with a rotation angle offset from the axis of symmetry.

6. A light assembly as recited in claim 4 wherein the housing comprises an offset ellipsoidal reflector portion transitioning into a heat dissipating element.

7. A light assembly as recited in claim 1 wherein the reflector is coupled to the circuit board and a housing acting as a heat sink.

8. A light assembly as recited in claim 1 further comprising a light-shifting element disposed within the enclosure.

9. A light assembly as recited in claim 8 wherein the light-shifting element comprises a film having a material having a light-shifting gradient having a first light-shifting rate adjacent the cover and a second light-shifting rate adjacent the center point greater than the first light-shifting rate.

10. A light assembly as recited in claim 8 wherein the light-shifting element is disposed between the first focal point and the plurality of light-emitting diodes.

11. A light assembly as recited in claim 8 wherein the light-shifting element is spherical.

12. A light assembly as recited in claim 8 wherein the light-shifting element comprises a dome coupled to the circuit board.

13. A light assembly as recited in claim 1 wherein the plurality of light-emitting diodes generates heat, said circuit board conducting heat in a radially outward direction to a heat sink, said heat conducting through the heat sink toward the base.

14. A method comprising:

generating light from light-emitting diodes (LEDs) disposed in a first ring on a circuit board within a light assembly;

transmitting high angle light from the LEDs directly through a cover;

reflecting low angle light from the LEDs at a reflector, said reflector having a partial continuous rotated ellipsoidal shape having a common first focal point and a second ring of second focal points coincident with the first ring said reflector formed by rotating a major axis of an ellipse around the second ring while continually intersecting the first focal point; and

directing the low angle light to the first focal point from the reflector.

15. A method as recited in claim 14 further comprising shifting a low angle light frequency using a light-shifting element disposed between the reflector and the common first focal point.

16. A method as recited in claim 14 further comprising positioning a light-shifting film within the light assembly.

17. A method as recited in claim 14 further comprising shifting a low angle light frequency using a light-shifting element disposed at the common first focal point.

18. A method as recited in claim 14 further comprising positioning a light-shifting element at the common first focal point using a standoff extending from the circuit board.

19. A method as recited in claim 14 further comprising positioning a spherical light-shifting element at the common first focal point using a standoff extending from the circuit board.