Light guide with decoupling portion and shield collecting the decoupled rays

Patent metadata

Field	Value
Publication number	US-9256019-B2
Application number	US-201213535597-A
Country	US
Kind code	B2
Filing date	Jun 28, 2012
Priority date	Jun 29, 2011
Publication date	Feb 9, 2016
Grant date	Feb 9, 2016

Abstract

A light guide comprising an external surface forming a guiding diopter, the guide being suitable for guiding light rays by reflection on the guiding diopter. The guide comprises at least one decoupling portion, with a refraction decoupling diopter arranged so as to refract light rays to decouple them from the guide, and thus transmit them out of the guide through the refraction decoupling diopter.

First claim

What is claimed is:

1. A light guide comprising an external surface forming a guiding diopter, said light guide being suitable for guiding light rays by reflection on said guiding diopter;
wherein said light guide comprises a section comprising at least one decoupling portion, with a refraction decoupling diopter arranged so as to refract light rays to cause at least a portion of said light rays to leave said light guide and transmit them out of said light guide through said refraction decoupling diopter;
said at least one decoupling portion being arranged in substantial proximity to an input end of said light guide and defining a variable cross-section that generally decreases as it extends from an input face of said light guide to an end of said at least one decoupling portion, wherein said at least a portion of said light rays originating from said input end of said light guide are not reflected by said guiding diopter;
said at least one decoupling portion comprising an external surface arranged such that an angle of incidence of said at least a portion of said light rays with said external surface is less than a limiting angle between a refraction and a total reflection so that said at least a portion of said light rays passing through said at least one decoupling portion will be refracted by said at least one decoupling portion out of and away from said light guide;
wherein said light guide further comprises at least one shield spaced apart from and generally opposed to said at least one decoupling portion and arranged so as to collect said portion of said light rays leaving said at least one decoupling portion and reflect them back into said light guide.

2. The light guide according to claim 1 , wherein said light guide comprises at least two decoupling portions which are transversally opposite relative to a thickness of said light guide.

3. The light guide according to claim 2 , wherein said light guide comprises a section of variable cross-section forming a clearance or an unevenness, at least one of said at least two decoupling portions being arranged on said section of variable cross-section.

4. The light guide according to claim 2 , wherein at least one of said at least two decoupling portions forms a prismatic volume.

5. The light guide according to claim 2 , wherein a longitudinal cross-section of at least one of said at least two decoupling portions comprises a curved profile.

6. The light guide according to claim 2 , wherein said external surface comprises, on a rear face of said light guide, a series of reflecting facets intended to decouple by reflection rays passing through said light guide at least one of said at least two decoupling portions of said light guide being arranged on a rear face and/or a front face opposite to said rear face.

7. The light guide according to claim 1 , wherein said variable cross-section is adjacent to said input end of said light guide that comprises said input face admitting light into said light guide.

8. The light guide according to claim 7 , wherein said at least one decoupling portion is arranged in proximity to said input end of said light guide so as to mostly decouple light rays originating from said input end of said light guide without them being reflected by said guiding diopter.

9. The light guide according to claim 7 , wherein said variable cross-section of said light guide comprises means for fastening said light guide.

10. The light guide according to claim 1 , wherein said variable cross-section of said light guide comprises means for fastening said light guide.

11. The light guide according to claim 1 , wherein said refraction decoupling diopter of said at least one decoupling portion is generally inclined relative to an adjacent surface of said guiding diopter.

12. The light guide according to claim 1 , said at least one decoupling portion forms a prismatic volume.

13. The light guide according to claim 1 , wherein a longitudinal cross-section of said at least one decoupling portion comprises a curved profile.

14. The light guide according to claim 1 , wherein said external surface comprises, on a rear face of said light guide, a series of reflecting facets intended to decouple by reflection rays passing through said light guide, said least one decoupling portion of said light guide being arranged on a rear face and/or a front face opposite to said rear face.

15. The light guide according to claim 1 , wherein said variable cross-section of said light guide comprises means for fastening said light guide.

16. A lighting and/or signaling device for a vehicle comprising a light guide intended to be fed with light rays by a light source and having an optical axis corresponding to a main direction of lighting and/or of signaling;
said light guide comprising an external surface forming a guiding diopter, said light guide being suitable for guiding light rays by reflection on said guiding diopter;
wherein said light guide comprises at least one decoupling portion, with a refraction decoupling diopter arranged so as to refract light rays to decouple them from said light guide, and thus transmit them out of said light guide through said refraction decoupling diopter;
wherein said at least one decoupling portion is arranged in substantial proximity to an input end of said light guide so that said at least a portion of said light rays originating from said input end of said light guide are not reflected by said guiding diopter;
said at least one decoupling portion comprising an external surface arranged such that an angle of incidence of said at least a portion of said light rays with said external surface is less than a limiting angle between a refraction and a total reflection so that said at least a portion of said light rays passing through said at least one decoupling portion will be refracted by said at least one decoupling portion out of and away from said light guide; and
at least one shield generally opposed to said at least one decoupling portion near said input end of said light guide so as to collect said portion of said light rays leaving said at least one decoupling portion and reflect them back into said light guide.

17. The lighting and/or signaling device according to claim 16 , wherein said at least one shield is facing a front face of an external surface of said light guide.

18. The lighting and/or signaling device according to claim 16 , wherein said at least one shield is facing a rear face of an external surface of said light guide.

19. A light guide comprising an external surface forming a guiding diopter, said light guide being suitable for guiding light rays by reflection on said guiding diopter;
wherein said light guide comprises at least one decoupling portion, with a refraction decoupling diopter arranged so as to refract light rays to decouple them from said light guide, and thus transmit them out of said light guide through said refraction decoupling diopter;
wherein said at least one decoupling portion is arranged in substantial proximity to an input end of said light guide so that said at least a portion of said light rays originating from said input end of said light guide are not reflected by said guiding diopter, wherein said light guide comprises a rear face having a series of reflecting facets;
said at least one decoupling portion comprising an external surface arranged such that an angle of incidence of said at least a portion of said light rays with said external surface is less than a limiting angle between a refraction and a total reflection so tha

Assignees

• Godbillon Vincent
• Valeo Vision

Inventors

• Godbillon Vincent

Classifications

• F21S48/2268

  Mechanical Engineering · mapped topic

• G02B6/0018

  Redirecting means on the surface of the light guide · CPC title

• G02B6/002 Primary

  by shaping at least a portion of the light guide, e.g. with collimating, focussing or diverging surfaces · CPC title

• F21S48/2237

  Mechanical Engineering · mapped topic

• F21S48/225

  Mechanical Engineering · mapped topic