US 7,563,004 B2
Volumetric downlight light fixture
Paul Kenneth Pickard, Conyers, Ga. (US); James Michael Lay, Cumming, Ga. (US); Doyle Scott Butler, Dunwoody, Ga. (US); Mark Campbell Logan, Atlanta, Ga. (US); and Leslie Charles King, Loganville, Ga. (US)
Assigned to Acuity Brands, Inc., Atlanta, Ga. (US)
Filed on Jan. 16, 2007, as Appl. No. 11/653,781.
Claims priority of provisional application 60/759365, filed on Jan. 17, 2006.
Prior Publication US 2007/0177389 A1, Aug. 02, 2007
Int. Cl. F21V 5/02 (2006.01); F21V 5/04 (2006.01)
U.S. Cl. 362—309  [362/308; 362/329; 362/339] 20 Claims
OG exemplary drawing
 
1. A downlight fixture for directing light toward an area desired to be illuminated, comprising:
a reflector assembly comprising a base member having a bottom peripheral edge and defining an opening positioned in a central portion of the base member, wherein the bottom peripheral edge extends circumferentially substantially symmetrically about the central portion of the base member;
a light source for generating the light, the light source being mountable at least partially therein the opening of the reflector assembly; and
a lens assembly selectively mountable to a recessed portion of the base member of the reflector assembly thereabout the opening of the reflector assembly, the lens assembly comprising:
a) a lens having a curved central lens portion, the central lens portion having a substantially smooth exterior surface and an opposed prismatic surface that defines a concave face spaced from and facing the light source; and
b) a means for generating a plurality of spaced regions of reduced brightness to control high angle glare optically comprising a plurality of adjoining elongate prismatic elements formed on the prismatic surface of the central lens portion, wherein each prismatic element has a curved surface facing toward the light source, wherein each pair of adjoining elongate prismatic elements form a common elongate cusp edge, wherein each elongate prismatic element of the plurality of adjoining elongate prismatic elements is configured such that a reverse ray impacting the elongate prismatic element proximate the common cusp edge at an angle of incidence ω of at least about 40° will undergo total internal reflection and be reflected back into the area to be illuminated to form a region of reduced brightness on the exterior surface of the lens.