Lighting unit, especially for road illumination

Patent metadata

Field	Value
Publication number	US-9383083-B2
Application number	US-201314647516-A
Country	US
Kind code	B2
Filing date	Nov 22, 2013
Priority date	Nov 30, 2012
Publication date	Jul 5, 2016
Grant date	Jul 5, 2016

Abstract

The invention provides a lighting unit ( 100 ) comprising (a) a lighting unit cavity ( 130 ), (b) a light source unit ( 110 ), for light source unit light ( 111 ), wherein the light source unit ( 110 ) comprises a light source ( 1100 ) and a collimator ( 1200 ), and (c) a light exit window ( 120 ), configured to enclose at least part of the lighting unit cavity ( 130 ) and configured to allow transmission of at least part of the light source unit light ( 111 ) as a beam of light ( 101 ), wherein the light exit window ( 120 ) comprises an upstream face ( 125 ) and a downstream face ( 126 ), with the upstream face ( 125 ) directed to the lighting unit cavity ( 130 ); wherein the upstream face ( 125 ) comprises light outcoupling structures ( 140 ), configured to couple the light source unit light ( 111 ) via the light exit window ( 120 ) out of the lighting unit ( 100 ).

First claim

The invention claimed is:

1. A lighting unit comprising:
a lighting unit cavity,
a light source unit, configured to generate light source unit light, wherein the light source unit comprises a light source and a collimator, wherein the light source unit is configured to provide light source unit light in the lighting unit cavity, and
a light exit window, configured to enclose at least part of the lighting unit cavity and configured to allow transmission of at least part of the light source unit light as a beam of light, wherein the light exit window comprises an upstream face and a downstream face, with the upstream face directed to the lighting unit cavity;

wherein the lighting unit has a virtual first lighting unit axis in a virtual first lighting unit cross-sectional plane,
wherein within the cross-sectional plane over a length at least 30% of the light exit window:
the upstream face comprises light outcoupling structures, configured to couple the light source unit light via the light exit window out of the lighting unit, wherein the light outcoupling structures comprise prismatic light outcoupling structures,
the light source unit is configured to illuminate a specific subset of the light extracting structures and to generate the light source unit light at a point at the light exit window with a spread in an angle of incidence (β)≦20° of the light source unit light at said point, and

wherein the lighting unit is configured to generate the beam of light downstream of the light exit window having a beam angle (γ) in the range of 90-170° within the cross-sectional plane.

2. The lighting unit according to claim 1 , wherein further within the cross-sectional plane over a length at least 30% of the light exit window (120):
the light exit window is arranged under a slanting angle (α) in the range of 30-60° with the lighting unit axis.

3. The lighting unit according to claim 2 , wherein within the cross-sectional plane over a length at least 30% of the light exit window:
the light source unit is configured to generate the light source unit light at a point at the light exit window with a spread in an angle of incidence (β)≦10° of the light source unit light at said point.

4. The lighting unit according to claim 3 , wherein the light exit window is V-shaped with two facets arranged under an angle (δ) in the range of 45-90°.

5. The lighting unit according to claim 3 , wherein the light exit window has a curved shape.

6. The lighting unit according to claim 3 , wherein the light exit window comprises a plurality of facets with one facet arranged perpendicular to the first lighting unit axis.

7. The lighting unit according to claim 3 , wherein the light exit window is flat.

8. The lighting unit according to claim 7 , wherein the cavity has a cavity height and a largest cavity width, wherein the ratio of cavity height to cavity width is larger than 0.4.

9. The lighting unit according to claim 8 , wherein the collimator is configured to collimate the light source light in a direction perpendicular to the cross-sectional plane.

10. The lighting unit according to claim 9 , wherein part of the cavity is enclosed by a reflector.

11. The lighting unit according to claim 10 , wherein the upstream face further comprises a region with refractive light outcoupling structures, and wherein at least 50% of the upstream face comprises prismatic light outcoupling structures.

12. The lighting unit according to claim 11 , comprising an array of light source units, and an elongated light exit window, configured to enclose at least part of the lighting unit cavity and configured to allow transmission of at least part of the light source unit light as the beam of light.

13. The lighting unit according to claim 12 , further comprising a plurality of redirecting structures at the downstream face, wherein the redirecting structures are configured to control the spread of the beam of light in a direction perpendicular to the cross-sectional plane.

14. The lighting unit according to claim 13 , wherein the light source unit comprises a solid state LED (light emitting diode) and wherein the lighting unit is configured to generate the beam of light downstream of the light exit window having a beam angle (γ) in the range of 90-140°.

15. Use of the lighting unit according to claim 14 , for illumination of a road.

Assignees

• Koninkl Philips Nv

Inventors

• Pijlman Fetze
• Van Asselt Robert
• Tsang Peter Tjin Sjoe Kong
• Crompvoets Floris Maria Hermansz
• Van Lierop Maarten
• Eggink Hendrik Jan

Classifications

• F21V5/00

  Refractors for light sources (characterised by cooling arrangements F21V29/504) · CPC title

• F21Y2115/10

  Light-emitting diodes [LED] · CPC title

• F21W2131/103

  of streets or roads · CPC title

• F21S8/085 Primary

  of high-built type, e.g. street light · CPC title

• F21V15/01

  Housings, e.g. material or assembling of housing parts (F21V15/02 takes precedence {housings forming signs or letters G09F13/04}) · CPC title