APPARATUS AND METHOD FOR IMPROVED ILLUMINATION AREA FILL

• US 20090021945A1
• Filed: 09/13/2008
• Published: 01/22/2009
• 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
• Granted Patent: US 7,581,855 B2
• Time in Patent Office: Days
• US Class Current: 362/296.10
• 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

1-24. -24. (canceled)

25. A method for illuminating a surface comprising:

radiating light from 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

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

where the reflector has a defined shape derived from a transfer function, which has as inputs;

the three dimensional radiation pattern of the light source;

beam parameters, such as light source-to-surface distance and beam diameter;

system parameters of the reflector such as reflector size and aperture size of the reflector; and

a desired composite energy distribution on the surface; and

which has as outputs;

an amount of directly radiated energy propagating through the aperture of the reflector;

a remainder of the total available radiated energy from the light source less the energy of the light directly radiating to the surface through the reflector aperture; and

a calculated position and orientation of each point on the reflector as a function of angle needed to provide the desired composite energy distribution on the surface, which calculation defines the shape of the reflector necessary to provide a reflected energy pattern to overlay the directly radiated energy pattern to form the designer controlled composite energy distribution on the surface.

26. The method of claim 25 where directly radiating and reflecting light substantially transmits all the light generated from the light source into the designer controlled composite energy distribution pattern on the surface.

27. The method of claim 25 where directly radiating and reflecting light transmits at least 90% of the light generated from the light source into the designer controlled composite energy distribution pattern on the surface.

28. A method of computerized design of a shape of a reflector having a three dimensional surface, a base and aperture, the reflector for reflecting light from a light source whose intensity varies as a function of three dimensional angles of light rays radiated from the light source comprising defining a shape for the reflector which shape is derived from a transfer function in a computer, which transfer function comprises inputting:

the three dimensional radiation pattern of the light source;

beam parameters, such as light source-to-surface distance and beam diameter;

system parameters of the reflector such as reflector size and aperture size of the reflector; and

a desired composite energy distribution on the surface; and

outputting;

an amount of directly radiated energy propagating through the aperture of the reflector;

a remainder of the total available radiated energy from the light source less the energy of the light directly radiating to the surface through the reflector aperture; and

a calculated position and orientation of each point on the reflector as a function of angle needed to provide the desired composite energy distribution on the surface, which calculation defines the shape of the reflector necessary to provide a reflected energy pattern to overlay the directly radiated energy pattern to form the designer controlled composite energy distribution on the surface.

29. An apparatus for illuminating a surface with an arbitrarily selected composite energy distribution comprising:

a light source, and

a reflector having an aperture, the reflector being proximate to the light source, light being directly radiated from the light source through the aperture of the reflector to the surface to provide a directly radiated energy distribution pattern on the surface,

where the reflector has a selectively defined shape at each point with a selectively defined spatial position and selectively defined orientation derived from the arbitrarily selected composite energy distribution, which reflector generates a reflected energy distribution onto the surface, which when overlaid onto the directly radiated energy distribution pattern on the surface produces the arbitrarily selected composite energy distribution on the surface.

30-34. -34. (canceled)