Illumination system for non-imaging reflective collector

• US 4,956,759 A
• Filed: 12/30/1988
• Issued: 09/11/1990
• Est. Priority Date: 12/30/1988
• Status: Expired due to Fees

• Current Assignee: North American Philips Corp. (Koninklijke Philips N.V.)
• Original Assignee: North American Philips Corp. (Koninklijke Philips N.V.)
• Inventors: Winston, Roland, Goldenberg, Jill F.
• Primary Examiner(s): Lazarus, Ira S.
• Assistant Examiner(s): Cox, D. M.
• Application Number:
  US07/292,593
• Time in Patent Office: 620 Days
• Field of Search: 362/297, 362/298, 362/310, 362/341, 362/346, 362/347, 362/350, 362/296, 350/619, 350/620, 350/628, 353/120, 353/109
• US Class Current: 362/297
• CPC Class Codes: F21S 41/36 Combinations of two or more separate reflectors
• CPC Class Codes: G02B 19/0023 at least one surface having optical power
• CPC Class Codes: G02B 19/0047 for use with a light source G02B19/009, G02B19/0095 take precedence; details of lighting devices in general F21V; non-semiconductor lasers having optical devices external to the laser cavity H01S3/005

Abstract

A first concave mirror collects the light emitted by a light source in a first half space and forms a first image of the light source at a point proximate thereto. A second larger concave mirror opposite the first mirror forms second and third images from the respective source and first image. The second and third images are formed at the input aperture of a non-imaging reflector, which in turn emits the light uniformly through the output aperture thereof.

Claims

1. An illumination system comprising

a light source,

a first concave mirror positioned to collect substantially all of the luminous flux emitted within a first half space and to reflect it toward a second opposite half space, said first concave mirror being profiled to form a first image of said light source proximate to said light source,

a second concave mirror positioned to collect all the light emitted by the light source within said second half space as well as all the light reflected by said first concave mirror through said first image into said second half space, said second concave mirror being profiled to form a second image of said light source at a point remote therefrom and to form a third image proximate to said second image, said third image being formed from said first image,

a non-imaging reflector having an input aperture positioned to receive substantially all the light from said second and third images of said light source.

2. An illumination system as in claim 1, wherein said first and second concave mirrors are profiled so that said second and third images are accommodated by the input aperture of the non-imaging reflector.

3. An illumination system as in claim 1, wherein said first concave mirror is a spherical mirror having a center of curvature, said light source being located proximate to said center of curvature.

4. An illumination system as in claim 3, wherein said second concave mirror is a spherical mirror having a center of curvature offset from the center of curvature of said first mirror toward said input aperture by a given distance, whereby said second and third images are focussed near a point approximately twice said given distance from said light source.

5. An illumination system as in claim 4, wherein said light source, said centers of curvature, and all of said images lie substantially in a common plane.

6. An illumination system as in claim 1 wherein said second concave mirror is a spherical mirror.

7. An illumination system as in claim 1 wherein said second concave mirror is an elliptical mirror having a first focus proximate to said light source and a second focus proximate to said input aperture of said non-imaging reflector.

8. An illumination system as in claim 7 wherein said first concave mirror is an elliptical mirror having a first focus at said light source and a second focus at said first image, the major axes of the first and second concave mirrors being at least substantially coincident.

9. An illumination system as in claim 1 wherein said first concave mirror is an elliptical mirror having a focus proximate to said light source.

11. An illumination system as in claim 1, characterized in that said first and second concave mirrors are profiled so that said second and third images are accommodated by the input aperture of the non-imaging reflector.

12. An illumination system as in claim 1, characterized in that said first concave mirror is a spherical mirror having a center of curvature, said light source being located proximate to said center of curvature.

13. An illumination system as in claim 3, characterized in that said second concave mirror is a spherical mirror having a center of curvature offset from the center of curvature of said first mirror toward said input aperture by a given distance, whereby said second and third images are focused near a point approximately twice said given distance from said light source.

14. An illumination system as in claim 4, characterized in that said light source, said centers of curvature, and all of said images lie substantially in a common plane.

15. An illumination system as in claim 1 characterized in that said second concave mirror is a spherical mirror.

16. An illumination system as in claim 1 characterized in that said second concave mirror is an elliptical mirror having a first focus proximate to said light source and a second focus proximate to said input aperture of said non-imaging reflector.

17. An illumination system as in claim 7 characterized in that said first concave mirror is an elliptical mirror having a first focus proximate to said light source and a second focus proximate to said first image, the major axes of the first and second concave mirrors being at least substantially coincident.

18. An illumination system as in claim 1 characterized in that said first concave mirror is an elliptical mirror having a focus proximate to said light source.

10. An illumination system of the type comprising a light source and a first concave mirror positioned to collect substantially all the luminous flux emitted by said light source within a first half space and to reflect it toward a second opposite half space, said system further comprising a non-imaging reflector having an input aperture positioned to receive substantially all of the light emitted by said light source in said second half space as well as substantially all the light reflected by said first concave mirror into said second half space, characterized in that

said first concave mirror is profiled to form a first image of said light source at a point proximate thereto and in that said system further comprises a second concave mirror positioned to collect all the light emitted by the light source in the second half space as well as all the light reflected by said first concave mirror through said first image into said second half space, said second concave mirror being profiled to form a second image of said light source at a point remote therefrom and to form a third image at a point proximate to said second image, said third image being formed from said first image, said input aperture receiving substantially all the light from the second and third images of the light source.