LED devices for offset wide beam generation

• US 7,854,536 B2
• Filed: 08/13/2009
• Issued: 12/21/2010
• Est. Priority Date: 08/14/2008
• Status: Active Grant

• Current Assignee: Signify Holding B.V. (Signify N.V.)
• Original Assignee: Cooper Technologies Company (Eaton Corporation PLC.)
• Inventors: Holder, Ronald G., Rhoads, Greg
• Primary Examiner(s): TSO, LAURA K
• Application Number:
  US12/541,060
• Publication Number:
  US 20100039810A1
• Time in Patent Office: 495 Days
• Field of Search: 362/800, 362/249.02, 362/311.02, 362/545, 362/431
• US Class Current: 362/311.02
• CPC Class Codes: F21K 9/68 Details of reflectors forming part of the light source
• CPC Class Codes: F21K 9/90 Methods of manufacture
• CPC Class Codes: F21V 13/04 the elements being reflectors and refractors for vehicle rear lights F21S43/40
• CPC Class Codes: F21V 17/101 permanently, e.g. welding, gluing or riveting
• CPC Class Codes: F21V 17/164 the parts being subjected to bending, e.g. snap joints
• CPC Class Codes: F21V 3/02 characterised by the shape
• CPC Class Codes: F21V 5/04 of lens shape
• CPC Class Codes: F21V 7/00 Reflectors for light sources characterised by cooling arrangements F21V29/505
• CPC Class Codes: F21V 7/0066 specially adapted to cooperate with point like light sources; specially adapted to cooperate with light sources the shape of which is unspecified F21V7/16 - F21V7/30 take precedence
• CPC Class Codes: F21W 2131/103 of streets or roads
• CPC Class Codes: F21Y 2101/00 Point-like light sources
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: Y10S 362/80 Light emitting diode

Abstract

A light source is combined with an optic and a reflector. Light incident onto to the reflector is reflected with a single reflection. The reflector occupies a portion of a solid angle around the light source to the exclusion of the optic at least with respect to any optical function. The reflector directly receives a second portion of light. The optic occupies substantially all of the remaining portion of the predetermined solid angle to directly receive a first portion of light from the light source. A reflected beam from the reflector is reflected into a predetermined reflection pattern. The inner and/or outer surface of the optic is shaped to refract or direct light which is directly transmitted into the optic from the light source from a first portion of light and/or reflected into the optic from the reflector from the reflected beam into a predetermined beam.

Claims

1. An apparatus for illuminating a target surface with a predetermined composite pattern of light comprising:

a light source generating light having a predetermined radiation pattern radiated into a predetermined solid angle;

a reflector onto which light from the light source is incident and which incident light is reflected from the reflector with a single reflection to form a reflection pattern; and

an optic having an inner and outer surface, the reflector occupying a portion of the predetermined solid angle around the light source to the exclusion of the optic at least with respect to any optical function to directly receive a second portion of light from the light source, the optic occupying substantially all of the remaining portion of the predetermined solid angle to directly receive a first portion of light from the light source, a reflected beam from the reflector including substantially all of the second portion of light and being reflected into a predetermined reflection pattern, the inner or outer surface of the optic being shaped to refract or direct light which is directly transmitted into the optic from the light source from the first portion of light and reflected into the optic from the reflector from the reflected beam into a predetermined beam, which when incident on the target surface forms the predetermined composite pattern of light on the target surface,

where the optic is spatially configured with respect to the light source to directly receive substantially all of the light in the predetermined radiation pattern of the light source other than that portion directly incident on the reflector, which portion is reflected onto the inner surface of the optic, so that substantially all of the light in the predetermined radiation pattern, which is not absorbed or misdirected as a result of imperfect optical properties of the optic and reflector, is directed by the optic into the predetermined beam.

2. The apparatus of claim 1 where the predetermined radiation pattern of the light source is substantially hemispherical, and where the solid angle subtended by the reflector with respect to the light source is less than 2π

steradians.

3. The apparatus of claim 1 where the predetermined radiation pattern of the light source is substantially hemispherical, where the light source is positioned on an imaginary reference plane with the reflector subtending an azimuthal angle in the imaginary reference plane relative to the light source of less than 360°

.

4. The apparatus of claim 3 where the reflector subtends an azimuthal angle in the imaginary reference plane relative to the light source of approximately 315°

±

15°

so that the predetermined composite pattern of light on the target surface has an azimuthal beam spread on the target surface of approximately 45°

±

15°

.

5. The apparatus of claim 3 where the reflector subtends an azimuthal angle in the imaginary reference plane relative to the light source of approximately 300°

±

15°

so that the predetermined composite pattern of light on the target surface has an azimuthal beam spread on the target surface of approximately 60°

±

15°

.

6. The apparatus of claim 3 where the reflector subtends an azimuthal angle in the imaginary reference plane relative to the light source of approximately 270°

±

15°

so that the predetermined composite pattern of light on the target surface has an azimuthal beam spread on the target surface of approximately 90°

±

15°

.

7. The apparatus of claim 3 where the reflector subtends an azimuthal angle in the imaginary reference plane relative to the light source of approximately 240°

±

15°

so that the predetermined composite pattern of light on the target surface has an azimuthal beam spread on the target surface of approximately 120°

±

15°

.

8. The apparatus of claim 3 where the reflector subtends an azimuthal angle in the imaginary reference plane relative to the light source of approximately 0°

±

15°

so that the predetermined composite pattern of light on the target surface has an azimuthal beam spread on the target surface of approximately 180°

±

15°

.

9. The apparatus of claim 3 where the reflector subtends an azimuthal angle in the imaginary reference plane relative to the light source of approximately 90°

±

15°

so that the predetermined composite pattern of light on the target surface has an azimuthal beam spread on the target surface of approximately 270°

±

15°

.

10. The apparatus of claim 1 where the light source and reflector are positioned inside the optic.

11. The apparatus of claim 1 where the light source, optic and reflector comprise a lighting device, and further comprising a plurality of lighting devices and a carrier, the lighting devices arranged on the carrier to form an array of lighting devices to additively produce a predetermined collective beam which illuminates the target surface with the predetermined composite pattern of light.

12. The apparatus of claim 11 further comprising a fixture in which at least one array is disposed.

13. The apparatus of claim 12 further comprising a plurality of arrays disposed in the fixture to additively produce the predetermined collective beam which illuminates the target surface with the predetermined composite pattern of light.

14. The apparatus of claim 1 where the light source has a primary axis around which the predetermined radiation pattern is defined, an intensity of light of the predetermined radiation pattern being defined as a function of an azimuthal angle and polar angle with respect to the primary axis of the light source, where the reflector is positioned with respect to the light source, has a curved surface and has a shaped outline which are selected to substantially control at least one of either the azimuthal or polar angle dependence of the intensity of light of the predetermined composite pattern.

15. The apparatus of claim 1 where the light source has a primary axis around which the predetermined radiation pattern is defined, an intensity of light of the predetermined radiation pattern being defined as a function of an azimuthal angle and polar angle with respect to the primary axis of the light source, where the optic is positioned with respect to the light source, the shape of the inner and outer surfaces of the optic is selected to substantially control at least one of either the azimuthal or polar angle dependence of the intensity of light of the predetermined composite pattern.

16. The apparatus of claim 15 where the reflector is positioned with respect to the light source, has a curved surface, and has a shaped outline selected to substantially control the other one of either the azimuthal or polar angular dependence of the light intensity of the predetermined composite pattern.

17. The apparatus of claim 1 where the outer surface of the optic is shaped to have a smooth surface resistant to the accumulation or collection of dust, dirt, debris or any optically occluding material from the environment.

18. The apparatus of claim 1 where the reflector comprises a first surface mirror.

19. The apparatus of claim 1 where the reflector comprises a second surface mirror.

20. The apparatus of claim 1 where the optic has receiving surfaces defined therein and where the reflector is a reflector mounted into and oriented relative to the light source by the receiving surfaces of the optic.

21. The apparatus of claim 20 where the receiving surfaces of the optic and the reflector have interlocking shaped portions which are heat staked together when assembled.

22. The apparatus of claim 1 where a hemispherical space into which the predetermined beam is directed is defined into a front half hemisphere and a back half hemisphere and where the reflector is positioned relative to the light source, curved and provided with an outline such that a majority of the energy of the light in the predetermined radiation pattern is directed by the reflector and optic into the front half of the hemisphere.