Reflector and system

• US 8,162,504 B2
• Filed: 04/15/2009
• Issued: 04/24/2012
• Est. Priority Date: 04/15/2009
• Status: Expired due to Fees

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Zhang, Tong, Montgomery, David
• Primary Examiner(s): MAY, ROBERT J
• Application Number:
  US12/423,898
• Publication Number:
  US 20100265720A1
• Time in Patent Office: 1,105 Days
• Field of Search: 362222-224, 36221702-21709, 362297-309, 362326-327, 362335-338, 362/311.01, 362/296.01, 36229605-29608, 362/341, 362/347
• US Class Current: 362/217.05
• CPC Class Codes: F21V 13/04 the elements being reflectors and refractors for vehicle rear lights F21S43/40
• CPC Class Codes: F21V 7/005 with an elongated shape to cooperate with linear light sources
• CPC Class Codes: F21V 7/0091 using total internal reflection
• CPC Class Codes: F21V 7/24 characterised by the material
• CPC Class Codes: F21V 7/28 characterised by coatings
• CPC Class Codes: F21Y 2103/00 Elongate light sources, e.g. fluorescent tubes
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]

Abstract

An illumination system includes a light source and a reflector. The reflector includes a first optical interface adjacent the light source which redirects light emitted from the light source and incident on the first optical interface via Fresnel reflection. In addition, the reflector includes a second optical interface adjacent the first optical interface on a side opposite the light source, which reflects light passing through the first optical interface via total internal reflection back towards the first optical interface. Also, a light collection system includes such a reflector.

Claims

1. An illumination system, comprising:

a light source; and

a reflector having a focal point, the reflector including;

a first optical interface adjacent the light source which redirects light emitted from the light source and incident on the first optical interface via Fresnel reflection; and

a second optical interface adjacent the first optical interface on a side opposite the light source, which reflects light passing through the first optical interface via total internal reflection back towards the first optical interface,

wherein the reflector includes an optically transparent material which is curved in relation to the focal point with the light source located proximate the focal point, the optically transparent material having a flat surface on one side which forms a part of the first optical interface and redirects the light emitted from the light source via the Fresnel reflection toward the focal point, and a surface having a prism structure on an opposite side forming a part of the second optical interface to totally internally reflect the light passing through the first optical interface back towards the first optical interface and the focal point, and

wherein the light source is a linear light source and the reflector runs parallel the linear light source, and the prism structure comprises parallel grooves which run in a direction orthogonal to an axis of the linear light source.

2. The system of claim 1, wherein the reflector is shaped to compress the light reflected via Fresnel reflection generally in a first plane in which the focal point lies, and the prism structure is arranged to compress the light reflected via total internal reflection generally in a second plane in which the focal point lies and orthogonal to the first plane.

3. The system of claim 1, wherein the reflector compresses the light reflected via Fresnel reflection generally in a first plane in which the focal point lies, and compresses light which passes through the second optical interface without being totally internally reflected in generally a second plane in which the focal point lies orthogonal to the first plane.

4. The system of claim 1, further comprising an outer reflector adjacent the reflector on a side opposite the light source which reflects light which was incident on the second optical interface but not totally internally reflected.

5. The system of claim 4, wherein the outer reflector is coated with a highly reflective material.

6. The system of claim 4, wherein the outer reflector comprises a third optical interface adjacent the reflector which redirects light passing through the reflector via Fresnel reflection;

and

a fourth optical interface adjacent the third optical interface on a side opposite the reflector, which reflects light passing through the third optical interface via total internal reflection back towards the third optical interface.

7. The system of claim 4, wherein the reflector and outer reflector are each elliptical, circular or parabolic in cross section and share a same focal point where the light source is located.

8. The system of claim 4, wherein the reflector and outer reflector are each elliptical, circular or parabolic in cross section and have different respective focal points proximate where the light source is located.

9. The system of claim 4, wherein the second optical interface diffracts the light which was not totally internally reflected towards an angle near normal to the outer reflector.

10. The system of claim 1, wherein the reflector is made only of optically transparent material.

11. The system of claim 10, wherein the material is at least one of a glass material or a plastic material.

12. The system according to claim 1, wherein the first optical interface and second optical interface each comprise an air/substrate interface.

13. The system according to claim 1, wherein the prism structure comprises grooves having at least one varying alignment, pitch, top angle or top angle orientation.

14. The system of claim 1, wherein the second optical interface comprises parallel grooves which run in a direction parallel to an axis of the linear light source.

15. A lighting system, comprising a plurality of illumination systems according to claim 1 each representing a unit arranged in an array.

16. A lighting system according to claim 15, wherein features of the respective reflectors of the units vary to maintain uniformity of the light provided by the lighting system.

17. A light collection system, comprising:

a photo-electric light receiving element; and

a reflector having a focal point, the reflector including;

a first optical interface adjacent the light receiving element which redirects light incident on the first optical interface via Fresnel reflection towards the light receiving element; and

a second optical interface adjacent the first optical interface on a side opposite the light receiving element, which reflects light passing through the first optical interface via total internal reflection back towards the first optical interface,

wherein the reflector includes an optically transparent material which is curved in relation to the focal point with the light receiving element located proximate the focal point, the optically transparent material having a flat surface on one side which forms a part of the first optical interface and redirects the light incident on the first optical surface via the Fresnel reflection toward the focal point, and a surface having a prism structure on an opposite side forming a part of the second optical interface to totally internally reflect the light passing through the first optical interface back towards the first optical interface and the focal point, and

wherein the light receiving element is a linear light receiving element and the reflector runs parallel the linear light receiving element, and the prism structure comprises parallel grooves which run in a direction orthogonal to an axis of the linear light receiving element.

18. The system of claim 17, wherein the reflector is shaped to compress the light reflected via Fresnel reflection generally in a first plane, including the focal point, and the prism structure is arranged to compress the light reflected via total internal reflection generally in a second plane including the focal point orthogonal to the first plane.

19. The system of claim 17, wherein the reflector compresses the light reflected via Fresnel reflection generally in a first plane including the focal point, and compresses light which passes through the second optical interface without being totally internally reflected in generally a second plane including the focal point orthogonal to the first plane.