Patent Publication Number: US-8992043-B2

Title: Constructive occlusion lighting system and applications thereof

Description:
FIELD OF THE INVENTION 
     The present invention relates to lighting systems and, in particular, to lighting systems employing constructive occlusion. 
     BACKGROUND OF THE INVENTION 
     Constructive occlusion techniques have been developed to provide tailored light intensity distributions from luminaires, including low intensity illumination in regions not covered by direct illumination. Current luminaire systems utilize a mask and cavity structure to achieve constructive occlusion. Radiant energy from one or more light sources, for example, reflects and diffuses within the volume between the mask and the cavity. The mask constructively occludes the aperture of the cavity, and the reflected light emerging from between the mask and the cavity provides a desired illumination. 
     However, using a mask to occlude the aperture of the cavity results in losses in lighting efficiency from the luminaire. 
     SUMMARY OF EMBODIMENTS OF THE INVENTION 
     In view of the efficiency disadvantages of current constructive occlusion luminaires, the present invention, in some embodiments, provides luminaires having constructive occlusion light distributions while demonstrating increased lighting efficiencies. 
     In some embodiments, a luminaire described herein comprises at least one light source, at least one reflector cavity and an optical element positioned to receive light reflected from the at least one reflector cavity, wherein the luminaire does not comprise a mask at least partially occluding the aperture of the at least one reflector cavity. In some embodiments, the at least one reflector cavity is semi toroidal. Moreover, in some embodiments, the optical element comprises a reflective optical element, a refractive optical element or a combination thereof. 
     In another aspect, the present invention provides methods of lighting a surface. In some embodiments, a method of lighting a surface comprises providing a luminaire comprising at least one light source, at least one reflector cavity and an optical element positioned to receive light reflected from the at least one reflector cavity, wherein the luminaire does not comprise a mask at least partially occluding the aperture of the at least one reflector cavity, reflecting light from the light source off the at least one reflector cavity to the optical element and reflecting or refracting the light received from the at least one reflector cavity out of the luminaire with the optical element. 
     These and other embodiments are discussed in greater detail in the detailed description which follows. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side elevation view of a reflector according to an embodiment of the present invention. 
         FIG. 2  is a top perspective view of a reflector according to the embodiment of  FIG. 1 . 
         FIG. 3  is another top perspective view of a reflector according to the embodiment of  FIG. 1  wherein inner edges are shown with dotted lines. 
         FIG. 4  is a partial cross-sectional view of a reflector according to the embodiment of  FIG. 1 . 
         FIG. 5  is a top perspective view of a specular inner ring or lining configured to be disposed within a reflector according to an embodiment of the present invention. 
         FIG. 6  is a side elevation view of a luminaire according to one embodiment of the present invention wherein inner edges are shown with dotted lines. 
         FIG. 7  is a top perspective view of a luminaire according to an embodiment of the present invention wherein inner edges are shown with dotted lines. 
         FIG. 8  is a side elevation view of an optical element of a luminaire according to one embodiment of the present invention. 
         FIG. 8A  is a top perspective view of an optical element of a luminaire according to the embodiment of  FIG. 8 . 
         FIG. 9  is a side elevation view of an optical element of a luminaire according to one embodiment of the present invention. 
         FIG. 9A  is a top perspective view of an optical element of a luminaire according to the embodiment of  FIG. 9 . 
         FIG. 10  is a side elevation view of an optical element of a luminaire according to one embodiment of the present invention. 
         FIG. 10A  is a bottom perspective view of an optical element of a luminaire according to the embodiment of  FIG. 10 . 
         FIG. 11  is a side elevation view of an optical element of a luminaire according to one embodiment of the present invention. 
         FIG. 11A  is a bottom perspective view of an optical element of a luminaire according to the embodiment of  FIG. 11 . 
         FIG. 12  is a side elevation view of an optical element of a luminaire according to one embodiment of the present invention. 
         FIG. 12A  is a bottom perspective view of an optical element of a luminaire according to the embodiment of  FIG. 12 . 
         FIG. 13  is a side elevation view of an optical element of a luminaire according to one embodiment of the present invention. 
         FIG. 13A  is a top perspective view of an optical element of a luminaire according to the embodiment of  FIG. 13 . 
         FIG. 14  is a side elevation view of an optical element of a luminaire according to one embodiment of the present invention. 
         FIG. 14A  is a bottom perspective view of an optical element of a luminaire according to the embodiment of  FIG. 14 . 
         FIG. 15  is a side elevation view of a light-emitting diode (LED) mask for an annular arrangement of LED light sources of a luminaire according to one embodiment of the present invention. 
         FIG. 16  is a top perspective view of an annular arrangement of LED light sources of a luminaire wherein inner edges are shown with dotted lines. 
         FIG. 17  is a top perspective view of a heat sink for an annular arrangement of LED light sources of a luminaire according to one embodiment of the present invention wherein inner edges are shown with dotted lines. 
         FIG. 18  is a top perspective view of a circuit board for an annular arrangement of LED light sources of a luminaire according to an embodiment of the present invention. 
         FIG. 19  is a top perspective view of an occlusion shield of a luminaire according to one embodiment of the present invention wherein inner edges are shown with dotted lines. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION 
     The present invention can be understood more readily by reference to the following detailed description and drawings and their previous and following descriptions. Elements, apparatus and methods of the present invention, however, are not limited to the specific embodiments presented in the detailed description and drawings. It should be recognized that these embodiments are merely illustrative of the principles of the present invention. Numerous modifications and adaptations will be readily apparent to those of skill in the art without departing from the spirit and scope of the invention. 
     As described herein, the present invention, in some embodiments, provides luminaires having constructive occlusion light distributions without employing the traditional architectures used to achieve such distributions. As a result, luminaires described herein can demonstrate enhanced lighting efficiencies in comparison to prior luminaires utilizing constructive occlusion architectures. 
     In some embodiments a luminaire described herein comprises at least one light source, at least one reflector cavity and an optical element positioned to receive light reflected from the at least one reflector cavity, wherein the luminaire does not comprise a mask at least partially occluding the aperture of the at least one reflector cavity. Because the luminaire does not include a mask, the light can exit the luminaire unimpeded—in other words, light exiting the luminaire is not blocked (or masked) by any structure located within the opening of the luminaire. 
     With reference to  FIGS. 1-4 , in some embodiments, the at least one reflector cavity  110  comprises a plurality of reflector cavities, such as in a semi toroidal reflector  100 . Moreover, in some embodiments, a semi toroidal reflector  100  can further comprise a specular inner ring  120  as illustrated in  FIG. 5 . A specular inner ring  120  in some embodiments is positioned along the rim  102  of the semi toroidal reflector  100 , as shown in  FIG. 4 . 
     With reference to  FIGS. 6 and 7 , in some embodiments, the optical element  130  of a luminaire  200  is at least partially disposed in the at least one reflector cavity  110 . In some embodiments, an optical element  130  is centered in the reflector cavity  110 . In some embodiments, an optical element  130  is coupled to a surface  140  of the at least one reflector cavity  110 . 
     In some embodiments, an optical element  130  is removably coupled to the surface  140  of the at least one reflector cavity  110 , thereby permitting interchangeability with other optical elements to create different light distributions, surface effects and/or color. The size and shape of the optical element  130 , in some embodiments, can vary to create different sized distributions and output larger or smaller candle power distributions. The optical element  130 , in some embodiments, can protrude outside the reflector cavity  110  to widen the light distribution above 180 degrees. 
     As described herein, an optical element  130  is operable to receive light reflected from the at least one reflector cavity  110  and reflect and/or refract the received light out of the luminaire  200 . In reflecting and/or refracting light received from one or more reflector cavities  110 , the optical element  130  can tailor the light distribution of the luminaire  200 . Moreover, as the optical element  130  does not block light as a mask does in prior luminaires that utilize constructive occlusion, the optical element  130  increases lighting efficiencies. In some embodiments, luminaires described herein have an efficiency of at least 60% or at least 65%. In some embodiments, luminaires have an efficiency of at least 70% or at least 80%. 
     An optical element  130  can have any desired shape not inconsistent with the objectives of the present invention.  FIGS. 8-14A  illustrate various non-limiting shapes of optical elements  130  according to some embodiments of the present invention. In particular, the optical element may be a conical shape with a tapered side and smooth distal tip ( FIGS. 8 and 8A ), a dual-conical shape ( FIGS. 9 and 9A ), a conical shape with a rounded base ( FIGS. 10 and 10A ), a dual-pyramidal shape ( FIGS. 11 and 11A ), a conical shape with a tapered side and pointed distal tip ( FIGS. 12 and 12A ), an hourglass shape ( FIGS. 13 and 13A ) or a modified hourglass shape ( FIGS. 14 and 14A ). Additionally, an optical element  130  can be made from any material not inconsistent with the objectives of the present invention. In some embodiments, an optical element  130  comprises a metal, polymeric material or glass. In some embodiments, an optical element  130  is overcoated with one or more materials. An optical element  130 , in some embodiments, is finished with one or more treatments such as specular, semi-specular or textured features. In some embodiments, an optical element  130  is painted one or more colors or infused with a color. In other embodiments, an optical element  130  is colorless or radiation transmissive. 
     More specifically, at least a portion (or the entirety) of the optical element  130  and/or surface  140  of reflector cavity  110  may have extremely high surface reflectivity, preferably, but not necessarily, between 96%-99.5%, inclusive and more preferably 98.5-99%. To achieve the desired reflectivity, in one embodiment the optical element  130  and/or surface  140  of reflector cavity  110  is coated with a diffuse, reflective material, including, but not limited to, reflective paints. Alternatively, the optical element  130  and/or surface  140  of reflector cavity  110  could include a layer of a reflective flexible sheet of material such as one or more of the materials sold under the tradenames GL-22, GL-80, GL-30 or Optilon™, all available from DuPont. Alternative materials include Miro® reflective aluminum materials, available from Alanod, and micro cellular polyethylene (“MCPET”), available from Furukawa. Specular materials would also be suitable. The reflective material may be substantially glossy or substantially flat. In one example, the reflective material is preferably matte white to diffusely reflect incident light. Other embodiments may utilize textured or colored paints or impart a baffled shape to the interior optical element  130  and/or surface  140  of reflector cavity  110  to obtain a desired reflection. Alternatively, the optical element  130  and/or surface  140  of reflector cavity  110  can be formed from a reflective material so that the surface of the optical element  130  and/or surface  140  of reflector cavity  110  need not be separately treated to attain the desired reflectivity. 
     It will be recognized that some light may, but need not necessarily, reflect directly off the surface  140  of reflector cavity  110  and exit the luminaire  200  without first reflecting off the optical element  130 . 
     In some embodiments, a light source for a luminaire described herein comprises one or more LEDs  150 . In some embodiments, a plurality of LEDs  150  are arranged on a printed circuit board  170  (see  FIG. 18 ) in an annular arrangement as illustrated in  FIGS. 15 and 16 . The printed circuit board  170  may include a beveled portion  155  that partially extends into the reflector cavity  110  when the printed circuit board  170  is installed in the luminaire so that direct light from the plurality of LEDs  150  is not visible from outside the luminaire  200 . 
     In one embodiment a heat sink  160  (see  FIG. 17 ) is attached to the luminaire, as illustrated in  FIG. 6 . The heat sink  160  may be provided for thermal management of heat generated by the plurality of LEDs  150 . As shown in  FIG. 6 , the heat sink is directly attached to the luminaire  200  for conductive removal of heat from the plurality of LEDs  150 . Convective removal of heat from the plurality of LEDs  150  may be achieved by circulation of air within the reflector cavity  110  of the luminaire  200 . 
     In some embodiments, a luminaire  200  described herein further comprises an occlusion shield  180 . An occlusion shield  180 , in some embodiments, can widen or narrow the distribution of light out of the luminaire  200 . As the occlusion shield  180  is cylindrical and hollow. In some embodiments, the occlusion shield  180  does not function as a mask in traditional constructively occluded architectures.  FIG. 19  illustrates an occlusion shield  180  according to one embodiment of the present invention. 
     With reference to  FIGS. 6 and 7 , an exemplary assembly of a luminaire  200  according to the present invention will now be described. The luminaire includes a reflector  100  having a reflector cavity  110 . An optical element  130  is removably attached to a surface  140  of the reflector  100 . A specular inner ring  120  may be positioned along the rim  102  of the reflector  100  (see  FIG. 4 ). An annular-shaped printed circuit board  170  having mounted thereon a plurality of LEDs  150  may be attached to the reflector  100  within the reflector cavity  110 . A heat sink  160  may be attached to the luminaire  200  to facilitate removal of heat generated by the plurality of LEDs  150 . An occlusion shield  180  may be installed along the inside perimeter of the reflector  100  to widen or narrow the distribution of light out of the luminaire  200 . 
     In another aspect, the present invention provides methods of lighting a surface. In some embodiments, a method of lighting a surface comprises providing a luminaire  200  comprising at least one light source, at least one reflector  100  having a reflector cavity  110  and an optical element  130  positioned to receive light reflected from the at least one reflector cavity  110 , wherein the luminaire  200  does not comprise a mask at least partially occluding the aperture of the at least one reflector cavity  110 , reflecting light from the light source off the at least one reflector cavity  110  to the optical element  130  and reflecting or refracting the light received from the at least one reflector cavity  110  out of the luminaire. 
     Various embodiments of the invention have been described in fulfillment of the various objectives of the invention. It should be recognized that these embodiments are merely illustrative of the principles of the present invention. Numerous modifications and adaptations thereof will be readily apparent to those skilled in the art without departing from the spirit and scope of the invention.