LED ILLUMINATION DEVICE WITH A HIGHLY UNIFORM ILLUMINATION PATTERN

• US 20080247170A1
• Filed: 05/08/2007
• Published: 10/09/2008
• Est. Priority Date: 03/03/2005
• Status: Active Grant

• Current Assignee: Dialight Corporation (Dialight PLC)
• Original Assignee: Dialight Corporation (Dialight PLC)
• Inventors: PECK, John P.
• Granted Patent: US 7,658,513 B2
• Time in Patent Office: Days
• US Class Current: 362/297
• CPC Class Codes: F21S 8/033 the surface being a wall or like vertical structure, e.g. building facade
• CPC Class Codes: F21V 7/0008 providing for indirect lighting
• 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 7/005 with an elongated shape to cooperate with linear light sources
• CPC Class Codes: F21V 7/0091 using total internal reflection
• CPC Class Codes: F21V 7/09 with a combination of different curvatures
• CPC Class Codes: F21W 2111/00 Use or application of lighting devices or systems for signalling, marking or indicating, not provided for in codes F21W2102/00 – F21W2107/00
• CPC Class Codes: F21W 2131/10 Outdoor lighting
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: Y10S 362/80 Light emitting diode

Abstract

An LED (light emitting diode) illumination device that can generate a uniform light output illumination pattern. The illumination source includes first and second reflectors with a conic or conic-like shape. One reflector is mounted in the same plane as the LED and wraps around the front of the LED to redirect the light emitted along a central axis of the LED.

Claims

1. An illumination source comprising:

an LED light source with a central axis;

a first reflector having a first reflecting surface with a first conic or conic-like shape, the first reflector passing directly in front of the central axis of the LED light source; and

a second reflector having a second reflecting surface with a second conic or conic-like shape, the second reflector not passing directly in front of the central axis of the LED.

2. An illumination source according to claim 1, wherein the light reflected off the first reflector is redirected from a positive angle to a dominantly negative angle.

3. An illumination source according to claim 1, wherein at least a portion of the light reflected off the second reflector is redirected from a negative angle to a positive angle.

4. An illumination source according to claim 2, wherein at least a portion of the light reflected off the second reflector is redirected from a negative angle to a positive angle.

5. An illumination source according to claim 1, wherein the conic or conic-like shape of each of the first and second reflectors has a shape selected from the group consisting of:

a hyperbola;

a parabola;

an ellipse;

a sphere;

or a modified conic.

6. An illumination source according to claim 1, wherein each of the first and second reflectors is formed of one of:

a metal;

a metalized surface;

or a reflectorized surface.

7. An illumination source according to claim 1, wherein the first and second reflecting surfaces are revolved in a circle.

8. An illumination source according to claim 1, wherein the first and second reflecting surfaces are extruded or projected linearly.

9. An illumination source according to claim 7, wherein the first and second reflecting surfaces are projected along a conic or conic-like curve.

10. An illumination source according to claim 1, wherein each of said first and second reflecting surfaces satisfies:

$z=\frac{{\mathrm{cr}}^2}{1+\sqrt{1-\left(1+k\right)<br><br>c^2<br><br>r^2}}$ $r^2=x^2+y^2,$

in which x, y, and z are positions on a 3-axis system, k is conic constant, and c is curvature.

11. An illumination source according to claim 1, wherein each of said first and second reflecting surfaces satisfies:

$z=\frac{{\mathrm{cr}}^2}{1+\sqrt{1-\left(1+k\right)<br><br>c^2<br><br>r^2}}+F$ $r^2=x^2+y^2,$

in which x, y, and z are positions on a 3-axis system, k is conic constant, c is curvature, and F is an arbitrary function.

12. An illumination source according to claim 8, wherein each of said first and second reflecting surfaces satisfies:

$z=\frac{{\mathrm{cr}}^2}{1+\sqrt{1-\left(1+k\right)<br><br>c^2<br><br>r^2}}$ $r^2=x^2+y^2,$

in which x, y, and z are positions on a 3-axis system, k is conic constant, and c is curvature.

13. An illumination source according to claim 9, wherein each of said first and second reflecting surfaces satisfies:

$z=\frac{{\mathrm{cr}}^2}{1+\sqrt{1-\left(1+k\right)<br><br>c^2<br><br>r^2}}+F$ $r^2=x^2+y^2,$

in which x, y, and z are positions on a 3-axis system, k is conic constant, c is curvature, and F is an arbitrary function.

14. An illumination source according to claim 1, wherein said first and second conic or conic-like reflecting surfaces are represented by a set of points and a basic curve or a spline fit, resulting in a conic-like shape of said first and second portions of the first reflector.