High efficiency compound parabolic concentrators and optical fiber powered spot luminaire

• US 5,727,108 A
• Filed: 09/30/1996
• Issued: 03/10/1998
• Est. Priority Date: 09/30/1996
• Status: Expired due to Term

• Current Assignee: Troy Investments, Inc.
• Original Assignee: Troy Investments, Inc.
• Inventors: Hed, Aharon Zeev
• Primary Examiner(s): Ullah, Akm E.
• Application Number:
  US08/724,069
• Time in Patent Office: 526 Days
• Field of Search: 385/54, 385/102, 385/58, 385/69, 385/74, 385/31, 385/33, 385/146, 385/901, 174/70 R, 439/206, 439/271, 439/578, 362/32, 362/347
• US Class Current: 385/133
• CPC Class Codes: G02B 6/0001 specially adapted for lighting devices or systems lighting or signalling on vehicles using light guides B60Q1/00; lighting devices for vehicle dashboards B60Q3/10; lighting devices for vehicle interior using light guides B60Q3/62; lighting devices mounted on the vehicle rear part using light guides F21S43/235; measuring arrangements having light conducting pointers G01D13/265; illumination of liquid crystal displays G02F1/1336; illuminated signs G09F13/00
• CPC Class Codes: G02B 6/0008 the light being emitted at the end of the fibre
• CPC Class Codes: G02B 6/262 Optical details of coupling light into, or out of, or between fibre ends, e.g. special fibre end shapes or associated optical elements

Abstract

A compound parabolic concentrator which can be used as an optical connector or in a like management system or simply as a concentrator or even as a spotlight, has a hollow body formed with an input aperture and an output aperture and a wall connecting the input aperture with the output aperture and diverting from the smaller of the cross sectional areas to the larger cross sectional areas of the apertures. The wall is composed of contiguous elongated prisms of a transparent dielectric material so that the single reflection from the inlet aperture to the outlet aperture takes place within the prisms and thus the losses of purely reflective reflectors can be avoided.

Claims

1. An optical device comprising:

a hollow body formed at one side with an input aperture of a first cross sectional area and connectable to a light source, and formed at an opposite side with an output aperture of a second cross sectional area different from said first area for delivery of light at said second cross sectional area; and

wall means connecting said input aperture with said output aperture and diverging from a smaller of said cross sectional areas to a larger of said cross sectional areas, said wall means consisting of contiguous elongated prisms facing the hollow of said body and of a transparent dielectric material extending between said apertures and defining internal reflection paths along a cross section of the material between said apertures and enabling single-reflection transmission of light from said inlet aperture to said outlet aperture within said wall means whereby the light flux is greater at said smaller of said cross sectional areas than at said larger of said cross sectional areas each of said prisms has a base flank defining a surface of said hollow body bounding an interior space thereof, and a pair of flanks including angles of 45°

with said base flank and 90°

with one another.

2. The optical device defined in claim 1 wherein said input aperture is said larger of said cross sectional areas and has a small acceptance angle, said output aperture has a large emission angle, and said device is an optical concentrator.

3. The optical device defined in claim 1 wherein said input aperture is said smaller of said cross sectional areas and has a large acceptance angle and said output aperture has a small emission angle.

4. The optical device defined in claim 1 wherein said body has a closed periphery around an axis connecting said input aperture with said output aperture.

5. The optical device defined in claim 1 wherein said wall means is formed with a pair of walls extending symmetrically on opposite sides of a median plane connecting said input aperture with said output aperture and said apertures are rectangular.

6. The optical device defined in claim 1 wherein said prisms periodically spaced larger prisms mechanically stiffening said body.

7. The optical device defined in claim 1 wherein said base flanks of adjoining prisms angularly adjoin one another.

8. The optical device defined in claim 1 wherein said base flanks of adjoining prisms merge smoothly into one another.

9. The optical device defined in claim 1 wherein the hollow of said body is a surface of revolution of generally parabolical shape.

10. The optical device defined in claim 9 wherein said surface of revolution is partly conical.

11. The optical device defined in claim 9 wherein said surface of revolution is partly hyperbolical.

12. The optical device defined in claim 1, further comprising at least one optical fiber coupled to said body at one of said apertures.

13. The optical device defined in claim 1 wherein said transparent dielectric material has a refractive index in excess of √

2.

14. The optical device defined in claim 1 wherein said transparent dielectric material has a refractive index in excess of 1.5.

15. An optical connector comprising two devices as defined in claim 1, the hollow body of one of said devices forms a light concentrator receiving light at its larger cross sectional area aperture, the other of said devices comprising another hollow body connectable to the first-mentioned hollow body with the larger cross sectional area apertures of said bodies being in alignment and said other hollow body receiving light at the smaller cross sectional area aperture thereof.

16. The optical connector defined in claim 15, further comprising a light modulator received between said larger cross sectional area apertures of said hollow bodies.

17. The optical connector defined in claim 15, further comprising means for moving one of said hollow bodies relative to the other hollow body to selectively bring said larger cross sectional area apertures of said hollow bodies into and out of alignment.

18. The optical device defined in claim 1, further comprising a protective housing enclosing said wall means out of contact therewith.

19. The optical device defined in claim 1, further comprising a window spanning said larger cross sectional area aperture.