LED light collection and uniform transmission system using a conical reflector with a roughed up inner surface

• US 20060092643A1
• Filed: 10/29/2004
• Published: 05/04/2006
• Est. Priority Date: 10/29/2004
• Status: Active Grant

• Current Assignee: Applied Innovative Technologies Incorporated
• Original Assignee: Applied Innovative Technologies Incorporated
• Inventors: Yim, Steven Yauhong, Vetorino, Steven Robert, Wong, Man Sheung, Sibell, Russell E.
• Granted Patent: US 7,125,160 B2
• Time in Patent Office: Days
• US Class Current: 362/308
• CPC Class Codes: F21V 13/04 the elements being reflectors and refractors for vehicle rear lights F21S43/40
• CPC Class Codes: F21V 5/048 the lens being a simple lens adapted to cooperate with a point-like source for emitting mainly in one direction and having an axis coincident with the main light transmission direction, e.g. convergent or divergent lenses, plano-concave or plano-convex lenses
• CPC Class Codes: F21V 7/28 characterised by coatings
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: G02B 27/0927 Systems for changing the beam intensity distribution, e.g. Gaussian to top-hat
• CPC Class Codes: G02B 27/0977 Reflective elements
• CPC Class Codes: G02B 5/0221 the surface having an irregular structure G02B5/0226 takes precedence
• CPC Class Codes: G02B 5/0268 characterized by the fabrication or manufacturing method
• CPC Class Codes: G02B 5/0284 used in reflection
• CPC Class Codes: Y10S 362/80 Light emitting diode

Abstract

Apparatus for collecting light from an LED and transmitting it in a near-uniform column incudes a conical reflector having a roughed up inner surface about the base of the LED for collecting light emitted to the sides of the LED, and a lens specially designed to focus the collected light into a near-collimated beam. The lens has opposite, substantially elliptical surfaces to collect and collimate the rapidly diverging light from the LED and the reflector, and each lens surface includes a flat spot to prevent shadows from forming, thereby producing a more uniform beam.

Claims

1. Apparatus for collecting and transmitting light in a near-uniform column from an LED of the type having a base, a light element and a domed transparent plastic housing attached to the base and covering the light element, the apparatus comprising:

a conical reflector disposed about the base of the LED for collecting sideband light from the LED light element and transmitting it forward;

wherein the conical reflector includes a roughed up inside surface in order to scatter the transmitted light;

a lens disposed opposite and apart from the housing of the LED for focusing the direct and reflected light from the LED, wherein the distance between the center of the lens and the center of the domed housing on the LED is (d);

wherein the lens is bounded by two opposite, substantially elliptical surfaces, where (a) is the half thickness of the lens and (b) is the half diameter of the lens and wherein each surface includes a flat spot having diameter (s).

2. The apparatus of claim 1 wherein flat spot diameter (s) is between about 5% and 10% of separation distance (d).

3. The apparatus of claim 1 wherein the conical reflector forms a cone angle of about 70°

.

4. The apparatus of claim 1 wherein the conical reflector intersects the LED at an offset distance (c) of about 0.04 inches from the center of the domed housing on the LED toward the base.

5. The apparatus of claim 1 wherein the half diameter (b) of the lens is greater than or equal to about 70% of separation distance (d).

6. The apparatus of claim 1 wherein the half thickness of the lens (a) is approximately equal to the spot diameter (s).

7. The apparatus of claim 1 wherein the half thickness of the lens (a) is approximately equal to 1.5 times the edge thickness (e) of the lens.

8. The apparatus of claim 1 wherein (d) is approximately 1 inch, half thickness (a) is about 0.24 inches, half diameter (b) is about 0.70 inches, and edge thickness (e) of the lens is about 0.16 inches.

9. The apparatus of claim 1 wherein the surface roughness was formed by bead blasting.

10. The apparatus of claim 8 wherein the bead blasting was performed with beads on the order of 0.001 inch in diameter.

11. The apparatus of claim 8 wherein the bead blasting was applied to a mold used to form the reflector.

12. The apparatus of claim 1 further including one of either a metallic or a dielectric coating formed over the roughed up surface.

17. The apparatus of claim 12 wherein the half thickness of the lens (a) is approximately equal to the spot diameter (s).

18. The apparatus of claim 12 wherein the half thickness of the lens (a) is approximately equal to 1.5 times the edge thickness (e) of the lens.

19. The apparatus of claim 12 wherein the surface roughness was formed by bead blasting.

20. The apparatus of claim 19 wherein the bead blasting was performed with beads on the order of 0.001 inch in diameter.

21. The apparatus of claim 19 wherein the bead blasting was applied to a mold used to form the reflector.

13. Apparatus for collecting and transmitting light in a near-uniform column from an LED of the type having a base, a light element and a domed transparent plastic housing attached to the base and covering the light element, the apparatus comprising:

a conical reflector disposed about the base of the LED for collecting sideband light from the LED light element and transmitting it forward, wherein the conical reflector includes an inside surface that is slightly roughed up in order to scatter the transmitted light;

a lens disposed opposite and apart from the housing of the LED for focusing the direct and reflected light from the LED, wherein the distance between the center of the lens and the center of the domed housing on the LED is (d);

wherein the lens is bounded by two opposite, substantially elliptical surfaces, where (a) is the half thickness of the lens and (b) is the half diameter of the lens and wherein each surface includes a flat spot having diameter (s); and

wherein flat spot diameter (s) is between about 5% and 10% of separation distance (d).

14. The apparatus of claim 13 wherein the conical reflector forms a cone angle of about 70°

.

15. The apparatus of claim 13 wherein the conical reflector intersects the LED at an offset (c) of about 0.04 inches from the center of the domed plastic housing toward the base.

16. The apparatus of claim 13 wherein the half diameter (b) of the lens is greater than or equal to about 70% of separation distance (d).

22. The apparatus of claim 13 further including one of either a metallic or a dielectric coating formed over the roughed up surface.

23. A method of fabricating apparatus for collecting and transmitting light in a near-uniform column from an LED of the type having a base, a light element and a domed transparent plastic housing attached to the base and covering the light element, the method comprising the steps of:

forming a conical reflector;

roughing up an inside surface of the reflector;

disposing the reflector about the base of the LED for collecting sideband light from the LED light element and transmitting it forward;

forming a lens bounded by two opposite, substantially elliptical surfaces, wherein each surface includes a flat spot; and

placing the lens opposite and apart from the housing of the LED for focusing the direct and reflected light from the LED.

24. The method of claim 23 wherein the step of roughing up the surface is performed by bead blasting.

25. The method of claim 24 wherein the bead blasting step is performed with beads on the order of 0.001 inch in diameter.

26. The method of claim 23 wherein the step of forming the reflector is performed with a mold, and the bead blasting step is performed on the mold.

27. The method of claim 23 further including the step of applying one of either a metallic or a dielectric coating over the roughed up surface.