Apparatus for Providing Off-Axis Illumination

Abstract

A light emitting diode can emit light along an axis. An optic can be positioned to direct the emitted light off of the axis. The optic can comprise a base and a projection that rises from the base towards the light emitting diode. The projection can comprise a cavity that is oriented to receive the light emitted by the light emitting diode. The cavity can be slanted relative to the axis of the light emitting diode. A convex surface disposed at the bottom of the cavity can condense, focus, or collimate light. The projection can further comprise sides that totally internally reflect light.

What is claimed is: 
     
         1 . A lighting system comprising:
 a light emitting diode;   a secondary optic that extends along a secondary reference plane; and   a primary optic disposed between the secondary optic and the light emitting diode, the primary optic comprising:
 a base that is adjacent to the secondary optic and that extends along a primary reference plane; 
 a projection that projects from the base away from the secondary optic and towards the light emitting diode, the projection comprising:
 a cavity that extends into the projection, along an axis, and towards the base region, the cavity comprising:
 an aperture that receives light from the light emitting diode; 
 a bottom that receives a first portion of the light from the light emitting diode; and 
 a sidewall that extends circumferentially about the axis; and 
 
 a total internally reflective surface that extends circumferentially with respect to the cavity, and that is oriented to totally internally reflect a second portion of the light that passes through the sidewall, so that the second portion of the light is reflected towards the base, 
 
 wherein the axis forms an acute angle with the primary reference plane. 
   
     
     
         2 . The lighting system of  claim 1 , wherein the axis extends along a center of the cavity. 
     
     
         3 . The lighting system of  claim 1 , wherein the secondary optic comprises grooves. 
     
     
         4 . The lighting system of  claim 1 , wherein the acute angle is in a range between 85 and 55 degrees. 
     
     
         5 . The lighting system of  claim 1 , further comprising:
 a housing in which the light emitting diode, the primary optic and the secondary optic are disposed; and   a trim that is magnetically coupled to the housing.   
     
     
         6 . The lighting system of  claim 1 , wherein the axis is substantially perpendicular to the bottom of the cavity where the axis intersects the bottom. 
     
     
         7 . The lighting system of  claim 1 , wherein the primary optic consists of a unitary piece of optical material. 
     
     
         8 . The lighting system of  claim 1 , wherein the primary optic is configured to emit through the base a pattern of illumination that is skewed relative to the primary reference plane. 
     
     
         9 . The lighting system of  claim 1 , wherein the totally internally reflective surface comprises a first surface region and a second surface region that collectively circumscribe the cavity, with the first surface region extending circumferentially partially about the cavity and the second surface region extending circumferentially partially about the cavity,
 wherein the first surface region and the second surface region meet one another at two circumferential discontinuities.   
     
     
         10 . The lighting system of  claim 1 , wherein the totally internally reflective surface comprises two abrupt changes in form at two circumferential locations. 
     
     
         11 . The lighting system of  claim 1 , wherein the base comprises a rim circumscribes the projection. 
     
     
         12 . A system comprising:
 a light emitting diode;   a secondary optic that extends along a secondary reference plane and that comprises a pattern of grooves operative to refract light; and   a primary optic that is disposed between the light emitting diode and the secondary optic and that comprises:
 a first side that is oriented towards the secondary optic and that extends along a primary reference plane; and 
 a second side that is oriented away from the secondary optic and towards the light emitting diode and that comprises a projection that projects towards the light emitting diode, the projection comprising:
 a cavity that is positioned to receive light emitted by the light emitting diode and that extends along an axis; 
 a convex surface disposed at a bottom of the cavity; and 
 a totally internally reflective surface that circumscribes the cavity. 
 
   
     
     
         13 . The system of  claim 12 , wherein the axis forms:
 a first acute angle with the primary reference plane, and   a second acute angle with the secondary reference plane, the second acute angle larger than the first acute angle.   
     
     
         14 . The system of  claim 12 , wherein the light emitting diode comprises a second axis along which the light emitting diode emits light,
 wherein the convex surface and the totally internally reflective surface are configured to direct the light off the second axis in a direction, and   wherein the pattern of grooves are configured to direct the light further off the second axis in the direction.   
     
     
         15 . The system of  claim 12 , wherein the light emitting diode comprises a second axis along which the light from the light emitting diode is emitted,
 wherein the secondary optic is canted relative to the second axis,   wherein a gap separates the secondary optic from the primary optic, and   wherein the system comprises a luminaire.   
     
     
         16 . The system of  claim 12 , wherein
 the pattern of grooves comprises an array of prisms.   
     
     
         17 . The system of  claim 12 , further comprising a housing in which the light emitting diode, the primary optic, and the secondary optic are mounted,
 wherein the housing, the light emitting diode, the secondary optic and the primary optic comprise a luminaire,   wherein the luminaire is configured for recessed mounting in a ceiling.   
     
     
         18 . The system of  claim 12 , wherein the pattern of grooves are disposed on a side of the secondary optic that faces away from the primary optic and the light emitting diode. 
     
     
         19 . A system comprising:
 at least one light emitting diode;   a secondary optic that extends along a secondary reference plane; and   a primary optic disposed between the at least one light emitting diode and the secondary optic, the primary optic comprising:
 a base forming a first side that extends along a primary reference plane, the primary reference plane and the secondary reference plane forming a first acute angle; and 
 a second side that is opposite the first side and that comprises a projection that projects away from the first side and towards the at least one light emitting diode, the projection comprising:
 a cavity that is configured to receive light emitted by the at least one light emitting diode and that extends along an axis; 
 a bottom of the cavity; and 
 a totally internally reflective surface that circumscribes the cavity, 
 wherein the axis forms a second acute angle with the primary reference plane. 
 
   
     
     
         20 . The system of  claim 19 , further comprising:
 a luminaire housing in which the at least one light emitting diode, the secondary optic, and the primary optic are disposed; and   a trim that is magnetically coupled to the luminaire housing.