LED illumination device with a highly uniform illumination pattern

• US 8,814,382 B2
• Filed: 06/29/2012
• Issued: 08/26/2014
• Est. Priority Date: 10/16/2009
• Status: Active Grant

• Current Assignee: Dialight Corporation (Dialight PLC)
• Original Assignee: Dialight Corporation (Dialight PLC)
• Inventors: Peck, John P.
• Primary Examiner(s): Hanley, Britt D
• Application Number:
  US13/537,212
• Publication Number:
  US 20120262919A1
• Time in Patent Office: 788 Days
• Field of Search: None
• US Class Current: 362/235
• CPC Class Codes: F21K 9/68 Details of reflectors forming part of the light source
• CPC Class Codes: F21V 7/005 with an elongated shape to cooperate with linear light sources
• CPC Class Codes: F21V 7/04 Optical design
• CPC Class Codes: F21V 7/09 with a combination of different curvatures
• CPC Class Codes: F21W 2131/103 of streets or roads
• CPC Class Codes: F21Y 2103/10 comprising a linear array of point-like light-generating elements
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]

Abstract

An LED (light emitting diode) illumination device that can generate a uniform light output illumination pattern. The illumination device includes an array of LEDs, each having a LED central axis. The LED central axis of the array of LEDs is angled approximately toward a central point. The illumination source includes a reflector with a conic or conic-like shape. The reflector wraps around the front of the LED to redirect the light emitted along a LED central axis.

Claims

1. An illumination source comprising:

a plurality of light emitting diode (LED) illumination devices arranged to emit light in a circular illumination pattern having a uniform illumination pattern, wherein each one of the LED illumination devices comprises;

a plurality of LED light sources arranged in an array, wherein each one of the plurality of LED light sources comprises an LED central axis at 0 degrees; and

a reflector, wherein a cross section of the reflector is projected along a line, wherein the reflector comprises a conic-like cross section, wherein each one of the plurality of LED light sources is positioned relative to the reflector such that a maximum illumination of each one of the plurality of LED illumination devices is at a distance to a mounting height ratio greater than 1 and at least a portion of light emitted by each one of the plurality of LED light sources between −

10 degrees and −

40 degrees is reflected by the reflector to angles between −

100 degrees and −

180 degrees.

2. The illumination source according to claim 1, wherein the plurality of LED illumination devices comprises three or more LED illumination devices.

3. The illumination source according to claim 2, wherein the plurality of LED illumination devices comprises six LED illumination devices arranged about 60 degrees apart between each one of the six LED illumination devices.

4. The illumination source according to claim 1, wherein the illumination devices are connected together.

5. The illumination source according to claim 1, wherein the plurality of LED illumination devices is angled relative to each other on approximately the same plane.

6. The illumination source according to claim 1, wherein each one of the plurality of LED light sources is positioned on a plane in a line.

7. The illumination source according to claim 1, wherein each one of the plurality of LED light sources is staggered about a line.

8. The illumination source according to claim 1, wherein the LED central axis of each of the plurality of LED light sources is angled approximately toward a central point of the illumination source.

9. The illumination source according to claim 1, wherein at least a second portion of light emitted by each one of the plurality of LED light sources is not reflected by the reflector.

10. The illumination source according to claim 1, wherein the reflectors are shaped such that a light emitted from each one of the plurality of LED light sources is redirected away from the central axis by the reflectors.

11. The illumination source according to claim 1, wherein light emitted from each one of the plurality of LED light sources has a cosine-like intensity profile.

12. The illumination source according to claim 1, wherein light emitted from each one of the plurality of LED light sources at positive angles is reflected by the reflector to negative angles with respect to the LED central axis.

13. The illumination source according to claim 1, further comprising:

a housing; and

a lens coupled to the housing and enclosing the plurality of LED illumination devices arranged in a 360 degree arrangement.

14. An illumination device, comprising:

a plurality of LED light sources arranged in an array, wherein each one of the plurality of LED light sources comprises an LED central axis at 0 degrees; and

a reflector, wherein a cross section of the reflector is projected along a line, wherein the reflector comprises a conic-like cross section, wherein at least a portion of the reflector reflects a light emitted by each one of the plurality of LED light sources such that a maximum illumination of the illumination device is at a distance to a mounting height ratio greater than 1 and at least a portion of the light emitted by the each one of the plurality of LED light sources between −

10 degrees and −

40 degrees to angles between −

100 degrees and −

180 degrees.

15. The illumination device of claim 14, wherein the plurality of LED illumination devices is angled relative to each other on approximately the same plane.

16. The illumination device of claim 14, wherein each one of the plurality of LED light sources is positioned on a plane in a line.

17. The illumination device of claim 14, wherein each one of the plurality of LED light sources is staggered about a line.

18. The illumination device of claim 14, wherein at least a second portion of light emitted by each one of the plurality of LED light sources is not reflected by the reflector.

19. The illumination device of claim 14, wherein light emitted from each one of the plurality of LED light sources has a cosine-like intensity profile.