Non-imaging light source for uniform illumination applications

• US 6,422,718 B1
• Filed: 11/18/1999
• Issued: 07/23/2002
• Est. Priority Date: 11/18/1999
• Status: Expired due to Term

• Current Assignee: Radiant Research Limited
• Original Assignee: Integrated Systems Technologies Limited
• Inventors: Baldwin, Kurt, Archenhold, Geoffrey, Neal, Andrew, Anderson, Keith
• Primary Examiner(s): O'Shea, Sandra
• Assistant Examiner(s): Negron, Ismael
• Application Number:
  US09/442,913
• Time in Patent Office: 978 Days
• Field of Search: 362/551, 362/552, 362/554, 362/580, 362/583, 362/227, 362/235, 362/236, 362/247, 362/294, 362/296, 362/310, 362/317, 362/341, 362/347, 362/350, 362/307, 362/297, 362/298, 362/300, 362/558
• US Class Current: 362/296.03
• CPC Class Codes: F21V 11/00 Screens not covered by groups F21V1/00, F21V3/00, F21V7/00 or F21V9/00 characterised by cooling arrangements F21V29/502
• CPC Class Codes: F21V 13/10 the elements being reflectors and screens
• CPC Class Codes: F21V 7/0008 providing for indirect lighting
• CPC Class Codes: F21V 7/04 Optical design
• CPC Class Codes: F21V 7/24 characterised by the material
• CPC Class Codes: F21V 7/28 characterised by coatings
• CPC Class Codes: G02B 6/4298 coupling with non-coherent light sources and/or radiation detectors, e.g. lamps, incandescent bulbs, scintillation chambers

Abstract

A light source system in which light scattered inside a chamber (2) exits from a hole (3) to provide a light output from the system. The interior wall of the chamber (2) consists of a material which is very efficient at scattering incident light. Light emitted from a light source (1) undergoes at least one scattering event within the chamber (2) before escaping from the chamber (2) through the exit hole (3). Any geometrical attributes of the light from the source (1) are removed before the light exists from the chamber (2). The exit hole (3) can have a tube inside (4) and/or outside (5) the chamber (2) for collimating the light output. A mechanical shutter (7, 8) can be used as a simple dimmer mechanism for the light output from the system. The light source (1) can be positioned inside or outside the chamber (2).

Claims

1. Apparatus comprising a light source, a chamber surrounding said light source, said chamber having an inner surface for scattering light from said light source, and an exit port in said chamber which provides for a light output, the arrangement being such that there is no direct path for light emitted from said light source to said exit port,

wherein said exit port is provided with means for collimating said light output, and

wherein said collimating means comprises a tube.

2. Apparatus according to claim 1 wherein said tube extends into said chamber and has an outer surface for scattering and/or reflecting light incident on said outer surface within said chamber.

3. Apparatus according to claim 1 wherein said tube extends out of said chamber and has an inner surface for reflecting light incident on said inner surface.

4. Apparatus according to claim 1 further comprising means for transmitting visible light from said light output and reflecting infra-red light from said light output, whereby heat in said light output is reduced.

5. Apparatus according to claim 1 wherein light from said light source is scattered by glass powder on an inner surface of said chamber.

6. Apparatus according to claim 1 wherein said light source is offset relative to the exit port.

7. Apparatus according to claim 1 wherein said light source is aligned with said exit port and is shielded from said exit port.

8. Apparatus according to claim 1 wherein said tube has an inner surface adapted to transmit light incident on said inner surface for further scattering and/or reflection within said chamber.

9. Apparatus according to claim 8 wherein said tube is formed with inclined slats providing openings for transmitting light incident on said inner surface.

10. Apparatus according to claim 1 wherein means is provided for vaying said light output intensity.

11. Apparatus according to claim 10 wherein said light output intensity vary means comprises an adjustable shutter or cover for said light source.

12. Apparatus according to claim 11 wherein said shutter or cover is controlled by a motor or manually.

13. Apparatus comprising a chamber and a light source external of said chamber, said chamber having an inner surface for scattering light from the light source, an entrance port for light from said light source to enter said chamber, and an exit port for a light output, wherein the arrangement of the light source, the entrance port, and the exit port is such that there is no direct path for light emitted from the light source to the exit port,

wherein said exit port is provided with means for collimating said light output, and

wherein said collimating means comprises a tube.

14. Apparatus according to claim 13 wherein said entrance port transmits visible light and reflects infrared radiation.

15. Apparatus according to claim 13 including a reflector for reflecting light from said light source towards said entrance port.

16. Apparatus according to claim 15 wherein said reflector reflects visible light and transmits infrared radiation.

17. Apparatus comprising:

a light source;

a chamber surrounding said light source, said chamber having an inner surface for scattering light from said light source, and an exit port in said chamber which provides for a light output, the arrangement being such that there is no direct path for light emitted from said light source to said exit port;

optic fibres for collecting said light output for fibre lighting; and

means for focusing said light output into said optic fibres comprising ball lenses and spacers between said optic fibres forming pockets for locating said ball lenses.

18. Apparatus comprising a light source, a chamber surrounding said light source, said chamber having an inner surface for scattering light from said light source, and an exit port in said chamber which provides for a light output, the arrangement being such that there is no direct path for light emitted from said light source to said exit port,

wherein said chamber is provided with means for reducing heat build-up within said chamber,

said chamber heat reduction means comprising a window provided in a wall of said chamber, said window having a reflection/transmission characteristic for reflecting visible radiation back into said chamber and transmitting infra-red radiation from said chamber.

19. Apparatus comprising a light source, a chamber surrounding said light source, said chamber having an inner surface for scattering light from said light source, and an exit port in said chamber which provides for a light output, the arrangement being such that there is no direct path for light emitted from said light source to said exit port,

wherein light from said light source is scattered by glass powder on an inner surface of said chamber, and

wherein said glass powder has a particle size of less than 10 microns approximately.