Apparatus and method for improved illumination area fill

• US 7,438,447 B2
• Filed: 12/04/2006
• Issued: 10/21/2008
• Est. Priority Date: 03/30/2004
• Status: Active Grant

• Current Assignee: Signify Holding B.V. (Signify N.V.)
• Original Assignee: Illumination Management Solutions Incorporated (Eaton Corporation PLC.)
• Inventors: Holder, Ronald G., Rhoads, Greg
• Primary Examiner(s): Choi; Jacob Y
• Application Number:
  US11/633,877
• Publication Number:
  US 20070076414A1
• Time in Patent Office: 687 Days
• Field of Search: 362/514, 362/516, 362/518, 362/215, 362/296, 362/297, 362/341, 362/346
• US Class Current: 362/346
• CPC Class Codes: F21K 9/233 specially adapted for generating a spot light distribution, e.g. for substitution of reflector lamps
• CPC Class Codes: F21V 13/04 the elements being reflectors and refractors for vehicle rear lights F21S43/40
• CPC Class Codes: F21V 7/0091 using total internal reflection
• CPC Class Codes: F21V 7/04 Optical design
• CPC Class Codes: F21V 7/09 with a combination of different curvatures
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: G02B 19/0028 refractive and reflective surfaces, e.g. non-imaging catadioptric systems
• CPC Class Codes: G02B 19/0061 the light source comprising a LED semiconductor devices with at least one potential-jump barrier or surface barrier specially adapted for light emission H01L33/00
• CPC Class Codes: H01L 33/58 Optical field-shaping elements
• CPC Class Codes: H01L 33/60 Reflective elements

Abstract

A reflector for a light source, such as an LED, is provided with a shape which efficiently collects and directs energy to an illumined surface whereby almost 100% of the light is collected and distributed into a designer composite beam. The shape in one embodiment is comprised of three zones beginning with a parabolic surface of revolution at the base of the reflector, followed by a transition or straight conic zone and ending with an elliptical zone. In another embodiment the reflector shape is determined according to a transfer function which allows for arbitrary designer control of the reflected rays at each point on the reflector, which when combined with direct radiation from the source, results in a designer controlled composite beam or illumination. The device is more than 90% energy efficient and allows replacement of higher power, less energy efficient light sources with no loss in illumination intensity.

Claims

1. An apparatus for illuminating a illumined surface comprising:

a light source whose intensity varies as a function of the angles of the light rays radiated from the light source in a three dimensional radiation pattern, and

a reflector having a base and aperture, the reflector being proximate to the light source, defining a system half angle by the optical aperture of the reflector and allowing directly radiated energy to propagate from the light source through the optical aperture of the reflector to the illumined surface to provide a directly radiated energy distribution pattern on the illumined surface,

the reflector having three distinct shaped zones, each zone providing a surface of revolution, the first zone being a parabolic surface of revolution, the second zone being a straight line surface of revolution and the third zone being an elliptical surface of revolution, in that order, beginning with the base of the reflector and moving toward the optical aperture of the reflector, without necessity of smooth transitions between the adjacent zones to allow freely controlled reflected energy distribution pattern to be overlaid onto the directly radiated energy distribution pattern on the illumined surface, which reflected energy distribution pattern combines with the directly radiated energy distribution pattern to produce a freely controlled composite energy distribution pattern on the illumined surface.

2. The apparatus of claim 1 where the three zones are arranged and configured so that substantially all the light generated from the light source is in the controlled composite energy distribution pattern on the illumined surface.

3. The apparatus of claim 1 where the three zones are arranged and configured so that at least 90% of the light generated from the light source is in the controlled composite energy distribution pattern on the illumined surface.

4. The apparatus of claim 1 where the reflector comprises a total internal reflector (TIR).

5. The apparatus of claim 4 where the light source comprises an LED light source and where the total internal reflector (TIR) is integrally manufactured as a package covering for or is optically integrated with the LED light source.

6. The apparatus of claim 4 where the total internal reflector has an exterior surface and further comprising a reflective coating disposed on a selected portion of the total internal reflector to insure internal reflection of light therein.

7. The apparatus of claim 5 where the total internal reflector has an exterior surface and further comprising a reflective coating disposed on a selected portion of the total internal reflector to insure internal reflection of light therein.

8. An apparatus for illuminating a surface comprising:

a light source whose intensity varies as a function of the three dimensional solid angles of the light rays radiated from the light source, and

a reflector having a base and optical aperture, the reflector being proximate to the light source, defining a system angle by the optical aperture of the reflector and allowing directly radiated energy to propagate from the light source through the optical aperture of the reflector to the surface to provide a directly radiated energy distribution pattern on the surface,

the reflector having at least two conic shaped zones and another zone, each providing a surface of revolution, the first zone being parabolic, the second zone being a flat transition surface and the third zone being elliptical, in that order, beginning with the base of the reflector and moving toward the optical aperture of the reflector, the flat transition surface extending between the first and third zones, without necessity of any smoothness where the first, second and third zones join each other, to provide a freely controlled reflected energy distribution pattern overlaid onto the directly radiated energy distribution pattern on the surface, which reflected energy distribution pattern combines with the directly radiated energy distribution pattern to produce a freely controlled composite energy distribution pattern on the surface.

9. An apparatus for illuminating a surface comprising:

a light source whose intensity varies as a function of the angles of the light rays radiated from the light source in a three dimensional radiation pattern, and

means for reflecting light, the means having a base and an optical aperture, the means being proximate to the light source, defining a system half angle by the optical aperture of the means and allowing directly radiated energy to propagate from the light source through the optical aperture of the means to the surface to provide a directly radiated energy distribution pattern on the surface, the means having three distinct shaped zones, each providing a surface of revolution, the first zone being parabolic, the second zone being linear and the third zone being elliptical, in that order, beginning with the base of the means and moving toward the optical aperture of the means without necessity for smoothness between zones, to provide a freely controlled reflected energy distribution pattern overlaid onto the directly radiated energy distribution pattern on the surface, which reflected energy distribution pattern combines with the directly radiated energy distribution pattern to produce a freely controlled composite energy distribution pattern on the surface.

10. A method for illuminating a surface comprising:

providing a size and shape of a parabolic zone, linear zone and elliptical zone of a reflector to produce an arbitrarily designed illumination pattern;

radiating light from a light source whose intensity varies as a function of the three dimensional solid angles of the light rays radiated from the light source, and

directly radiating light from the light source to the surface to provide a directly radiated energy distribution pattern on the surface,

reflecting light from the light source from the first parabolic zone of the reflector proximate to the light source onto a composite energy distribution pattern on the surface, the first parabolic zone being a surface of revolution using a segment of a parabola;

reflecting light from the light source from the second linear zone of the reflector adjacent to the first parabolic zone onto the composite energy distribution pattern on the surface, the second linear zone being a surface of revolution using a line segment; and

reflecting light from the light source from the third elliptical zone of the reflector adjacent to the second linear zone onto the composite energy distribution pattern on the surface, the third elliptical zone being a surface of revolution using a segment of an ellipse.

11. The method of claim 10 where directly radiating and reflecting light substantially transmits all the light generated from the light source into the arbitrarily designed illumination pattern on the surface.

12. The method of claim 10 where directly radiating and reflecting light transmits at least 90% of the light generated from the light source into the arbitrarily designed illumination pattern on the surface.