Recessed wall wash light fixture with glare control

Patent metadata

Field	Value
Publication number	US-9702522-B2
Application number	US-201514924233-A
Country	US
Kind code	B2
Filing date	Oct 27, 2015
Priority date	May 1, 2015
Publication date	Jul 11, 2017
Grant date	Jul 11, 2017

Abstract

A recessed wall wash light fixture includes a light source and a hollow light guide. The hollow light guide has a reflective internal surface and forms upper and lower apertures along its upper and lower boundaries. The lower aperture is slanted upwardly in the forward direction. The hollow light guide includes a forward section and a rear section having respective centerlines and wall surfaces. Both of the centerlines are concave with respect to one another, and the wall surfaces extend laterally from the centerlines and curve toward one another. The forward and rear wall surfaces substantially meet one another at midlines that extend downwardly from the upper aperture to the lower aperture.

First claim

What is claimed is:

1. A recessed wall wash light fixture that emits light downwardly and preferentially toward a forward azimuthal direction into a space beneath a ceiling, the light fixture comprising:
a light source that emits the light downwardly, defining an emitter axis that passes through a centroid of the light source and extends toward nadir;
a hollow light guide that reflects at least a portion of the light, wherein the hollow light guide substantially encloses a space between:
an upper aperture, wherein the light source is configured and oriented so as to emit the light through the upper aperture, and
a lower aperture that is slanted upwardly in the forward direction so as to have an upper, forward side and a lower, rearward side;

the hollow light guide consisting essentially of:
a first reflective sheet that is curved to form a forward section having:
a forward wall centerline that extends downwardly from a forward side of the upper aperture to the upper, forward side of the lower aperture, and is concave with respect to the emitter axis, and
forward wall surfaces that extend laterally from both sides of the forward wall centerline, and curve rearwardly; and

a second reflective sheet that is curved to form a rear section having:
a rear wall centerline that is concave with respect to the forward wall centerline, and curves downwardly from a rearward side of the upper aperture to the lower, rearward side of the lower aperture, and
rear wall surfaces that extend laterally from both sides of the rear wall centerline, and curve forwardly;

such that the forward and rear wall surfaces substantially meet one another at midlines that extend downwardly from the upper aperture to the lower aperture.

2. The recessed wall wash light fixture of claim 1 , further comprising a diffuser disposed across the lower aperture such that substantially all of the light passes through the diffuser.

3. The recessed wall wash light fixture of claim 1 , wherein the forward wall centerline tilts rearwardly such that the forward wall centerline is nearer the emitter axis at the lower aperture than at the upper aperture.

4. The recessed wall wash light fixture of claim 2 , further comprising a housing that includes a mounting flange that defines an output aperture for the light fixture, wherein:
the housing is configured to couple with the ceiling when an upper surface of the mounting flange abuts a lower surface of the ceiling;
the output aperture is an opening within a lowermost planar surface of the mounting flange;
the housing supports the diffuser, the hollow light guide and the light source such that, when the mounting flange couples with the ceiling:
the upper aperture of the hollow light guide defines a plane that is substantially parallel with the upper surface of the mounting flange; and
the lower aperture of the hollow light guide is disposed above the output aperture, and forms an angle of 10 to 50 degrees with respect to the upper surface of the mounting flange.

5. The recessed wall wash light fixture of claim 1 , wherein:
an azimuthal angle of any point on the hollow light guide is defined as an angle in a plane that is perpendicular to the emitter axis, between a reference line extending from the light source to an intersection of the forward wall centerline with the upper aperture, and the point on the hollow light guide, such that the forward wall centerline consists of a set of points having an azimuthal angle of zero;
a polar angle is defined as an angle between the plane that is perpendicular to the emitter axis and a line extending from the light source to the point on the hollow light guide; and
the forward wall centerline extends downwardly from the forward side of the upper aperture through a polar angle range from zero to at least seventy degrees.

6. The recessed wall wash light fixture of claim 5 , wherein the rear wall centerline extends downwardly from the rear side of the upper aperture through a polar angle range from zero to at least sixty degrees.

7. The recessed wall wash light fixture of claim 1 , wherein the forward and rear sections are disposed such that a portion of the light that reflects from the forward section along the forward wall centerline reflects from the rear section along the rear wall centerline and exits the lower aperture in the forward azimuthal direction.

8. The recessed wall wash light fixture of claim 5 , wherein the forward section and the rear section curve in both azimuthal and polar directions relative to the light source.

9. The recessed wall wash light fixture of claim 1 , wherein:
the forward section reflects a first portion of the light from the light source toward the rear section of the hollow light guide;
and the rear section:
re-reflects the first portion of the light from the light source such that it passes forwardly through the lower aperture of the hollow light guide, and
reflects a second portion of the light from the light source downwardly.

10. The recessed wall wash light fixture of claim 9 , wherein:
the first portion of the light extends azimuthally across a range of about ±30 degrees from the forward wall centerline, and
substantially all of the first portion of the light that reflects from the forward section re-reflects from the rear section.

11. The recessed wall wash light fixture of claim 1 , wherein the upper aperture is centered about the emitter axis.

12. The recessed wall wash light fixture of claim 1 , wherein the forward and rear sections are discrete physical sections that are joined to form the hollow light guide.

13. The recessed wall wash light fixture of claim 1 , wherein at least one of the forward section and the rear section is formed of a metal that is coated at least on an internally facing surface thereof with one or more reflection-enhancing films, such that a reflectance of the internally facing surface exceeds 94%.

14. The recessed wall wash light fixture of claim 13 , wherein at least one of the reflection-enhancing films comprises silver, and the reflectance of the internally facing surface exceeds 97%.

15. The recessed wall wash light fixture of claim 13 , wherein the rear section is formed of a planar sheet of the metal having the one or more reflection-enhancing films, wherein:
the planar sheet comprises tabs having sides that are separated by substantially triangular slots when the sheet is unbent, and
the sides of the tabs substantially meet when the sheet is bent to form the rear section.

16. The recessed wall wash light fixture of claim 7 , wherein the circuit board is disposed proximate to the upper aperture, and wherein the light enters through the upper aperture without passing through optics.

Assignees

• Abl Ip Holding Llc

Inventors

• Chen Jie
• Hughes Jeffrey Paige
• Marquardt Craig Eugene
• Onda Joseph J
• Juda Mike Ken
• Reilly John M

Classifications

• F21Y2115/10

  Light-emitting diodes [LED] · CPC title

• F21S8/026

  intended to be recessed in a ceiling or like overhead structure, e.g. suspended ceiling · CPC title

• F21V7/09 Primary

  with a combination of different curvatures · CPC title

• F21V7/0016

  on lighting devices that also provide for direct lighting, e.g. by means of independent light sources, by splitting of the light beam, by switching between both lighting modes · CPC title