Nonimaging optical illumination system

• US 6,019,485 A
• Filed: 10/06/1998
• Issued: 02/01/2000
• Est. Priority Date: 04/28/1993
• Status: Expired due to Term

• Current Assignee: Nioptics Corporation
• Original Assignee: 3M Company, ARCH Development Corporation (University of Chicago)
• Inventors: Ries, Harald, Winston, Roland
• Primary Examiner(s): LEE, Y MY QUACH
• Application Number:
  US09/167,373
• Time in Patent Office: 483 Days
• Field of Search: 362/217, 362/347, 362/350, 362/296, 362/341, 362/346
• US Class Current: 362/347
• CPC Class Codes: F21V 7/005 with an elongated shape to cooperate with linear light sources
• CPC Class Codes: F21V 7/04 Optical design
• CPC Class Codes: F24S 2023/838 involutes
• CPC Class Codes: F24S 23/70 with reflectors
• CPC Class Codes: F24S 23/80 having discontinuous faces
• 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
• CPC Class Codes: G02B 19/009 for use with infrared radiation
• CPC Class Codes: G02B 27/0927 Systems for changing the beam intensity distribution, e.g. Gaussian to top-hat
• CPC Class Codes: G02B 27/0983 being curved
• CPC Class Codes: Y02E 10/40 Solar thermal energy, e.g. solar towers

Abstract

A nonimaging illumination optical device for producing a selected far field illuminance over an angular range. The optical device includes a light source 102, a light reflecting surface 108, and a family of light edge rays defined along a reference line 104 with the reflecting surface 108 defined in terms of the reference line 104 as a parametric function R(t) where t is a scalar parameter position and R(t)=k(t)+Du(t) where k(t) is a parameterization of the reference line 104, and D is a distance from a point on the reference line 104 to the reflection surface 108 along the desired edge ray through the point.

Claims

1. A method of manufacturing a collector of light of irradiance I from a radiant source, comprising the steps of:

providing a transducer device for collecting the light; and

providing a light reflecting surface by constructing a reflector contour with a family of edge rays defined along a reference line defined by k(t) and forming a shape for said reflector contour relative to said reference line by tracing a vector R(t) to form said shape where t is a scalar parameter position and wherein;

space="preserve" listing-type="equation">R(t)=k(t)+Du(t)

where k(t)=a parameterization of said reference line;

D=a distance from a point on said reference line to said reflecting surface along a desired edge ray through the point;

n=unit vector along a desired direction of said desired edge ray;

with said reflector contour reflecting said desired edge ray into actual edge ray a(R(t)), where a is a multidimensional unit vector pointing towards an edge of said radiant light, and said D being the solutions of;

space="preserve" listing-type="equation">dD/dt=((dk(t)/dt)·

(a-u)+D(du/dt)·

a)/1-a·

u

2.

2. The method as defined in claim 1 further including the step of providing light refractive medium means characteristic of a dielectric for generating the family of edge rays.

3. The method as defined in claim 1 futher including the step of defining an edge ray having undergone multiple reflections.

4. The method as defined in claim 1 further including light refracting medium means and including the additional step of tailoring the desired edge ray into the actual edge ray.

5. The method as defined in claim 1 wherein said reflector contour is comprised of at least two reflector contours.

6. The method as defined in claim 5 wherein said two reflector contours comprise include a cusp positioned therebetween.

7. The method as defined in claim 6 wherein said two reflector contours comprise a mirror image surface disposed about said cusp.

8. The method as defined in claim 1 wherein said reflector contour is comprised of a compound concentrator reflector.

9. The method as defined in claim 8 wherein said compound concentrator reflector is selected from the group consisting of CHC, CEC and CPC.

10. The method as defined in claim 1 further including the step of defining said reflector contour by generating tangent lines to a surface of the contour, said tangent lines generating a trailing edge ray which is used in conjunction with a function describing the irradiance, I, to calculate a leading edge ray.

11. The method as defined in claim 1 wherein the expression dD/dt is used in conjunction with calculating the leading edge ray to determine a new portion of the reflector contour.

12. A method of collecting light of irradiance I from a radiant source over an angular range, comprising the steps of:

collecting light from the source using a transducer means; and

defining light means for manipulating light received from the source using at least one of the steps (a) using light refracting medium means and (b) using a light reflector contour having a reflective surface established by the step of defining a family of edge rays relative to a reference line expressed as k(t) and a point located on said reference line and further defined by a desired edge ray passing through the point and extending to said reflector contour, wherein t is a scalar parameter position and defining said reflector contour by applying an expression R(t);

space="preserve" listing-type="equation">R(t)=k(t)+Du(t)

where

k(t)=a parameterization of said reference line;

D=a distance from the point on said reference line to at least one of said refracting medium means and said reflecting surface along said desired edge ray through the point;

u=a unit vector along a desired direction of said desired edge ray;

and said reflector contour and said light refracting medium means reflecting and refracting, respectively, said desired edge ray into an actual edge ray a R(t)), where a is a multidimensional unit vector pointing towards an edge of said transducer means and wherein the desired edge ray is tailored into the actual edge ray by at least one of said reflector contour and said retracting medium means.

13. The method as defined in claim 12 further including the step of defining an edge ray having undergone multiple reflections.

14. The method as defined in claim 12 further including light refracting medium means and including the additional step of tailoring the desired edge ray into the actual edge ray.

15. The method as defined in claim 12 wherein said reflector contour comprises at least two reflector contours.

16. The method as defined in claim 15 wherein said two reflector contours include a cusp positioned therebetween.

17. The method as defined in claim 16 wherein said two reflector contours comprise a mirror image surface disposed about said cusp.

18. The method as defined in claim 12 wherein said reflector contour comprises a compound concentrator reflector.

19. The method as defined in claim 18 wherein said compound concentrator reflector is selected from the group consisting of CHC. CEC and CPC.

20. The method as defined in claim 12 further including the step of defining said reflector contour by generating tangent lines to a surface of the reflector contour, said tangent lines generating a trailing edge ray which is used in conjunction with a function describing the irradiance, I, to calculate a leading edge ray.

21. The method as defined claim 20 wherein the expression dD/dt is used in conjunction with calculating the leading edge ray to determine a new portion of the reflector contour.