Abstract:
Luminaires are disclosed that include refractive and/or reflective structures that can provide or distribute lighting for a given area with high uniformity and efficiency. The structures can be used to distribute light from one or more light sources for lighting target areas with a desired light distribution. The lighting structures can be included in light strips or luminaires. Such luminaire can be utilized in place of fluorescent lights and can facilitate quick and easy retrofit for previous fluorescent lighting applications. The disclosed techniques and systems (including components and structures) can be particularly useful when employing one or more LEDs as light sources.

Description:
FIELD OF THE DISCLOSURE 
     The present disclosure is directed generally to the use of light sources. More particularly the present disclosure is directed to lighting structures that include reflective and refractive elements that can be used to distribute light from one or more light sources in desired directions. 
     BACKGROUND OF THE DISCLOSURE 
     Different strategies have been designed to provide uniform and efficient light distribution over a given area. For example, display cases are commonly used in retail applications, such as the refrigerated cases in supermarkets and convenience stores, to display merchandise and are commonly arranged into banks of shelving displays or showcase displays for holding goods. Typically, such display cases are illuminated by fluorescent light fixtures. While providing certain benefits over incandescent lighting, fluorescent lights themselves have inherent power and maintenance requirements and related costs. Fluorescent lights also contain mercury causing substantial environmental concerns and costs. 
     Certain techniques have been employed to install alternate sources of lighting in place of fluorescent lights. Such techniques typically require contemporaneous altering of the structural support adjacent to the fluorescent light fixtures, such as by drilling holes. For applications including refrigerated food and beverage displays, such techniques can lead to unnecessary wasted cooling energy, excess labor, and possibly spoiling of the refrigerated items themselves as well as costs related to each. 
     Light emitting diodes (LEDs) have been used in various applications where incandescent or fluorescent lights have been used. Because individual LEDs are essentially point light sources, as opposed to continuous elements, such as incandescent and fluorescent lights, lighting uniformity has proven challenging to achieve for many applications. 
     SUMMARY OF THE DISCLOSURE 
     The present disclosure is directed to lighting structures including refractive and/or reflective structures that can provide or distribute lighting for a given area with high uniformity and efficiency. The lighting structures can include a reflector, configured to reflect light from an adjacent light source, the reflector defining one or more apertures configured to allow light from the light source to pass therethrough. The structures can be used to distribute light from one or more light sources for lighting target areas with a desired light distribution. Other aspects, embodiments, and details of the present disclosure will be apparent from the following description when read together with the accompanying drawings. 
     The lighting structures can be included in light strips or luminaires. Such light strips or luminaires can be utilized in place of fluorescent lights and can facilitate quick and easy retrofit for previous fluorescent lighting applications. The disclosed techniques and systems (including components and structures) can be particularly useful when employing one or more LEDs or the like as light sources. 
     Light distribution structures according to the present disclosure can include a refractive element and a reflective element. 
     An exemplary embodiment can include a luminaire including any of the previously mentioned reflective elements or reflectors may be configured to reflect a first portion of light received from a light source in one or more desired directions and to allow a second portion of light from the light source to pass therethrough in one or more desired directions; and a refractive element configured to receive one or both of the first and second portions of light and transmit both in desired directions. 
     Another exemplary embodiment can include a luminaire having a light source for emitting light, a reflector having a first side and a second side, the reflector configured and situated such that a first portion of the light emitted by the light source passes through the reflector from the first side to the second side, and a second portion of the light emitted by the light source is reflected by the first side of the reflector. The luminaire can be configured such the first portion of light emitted by the light source passes through an aperture defined in the reflector. The reflector may optionally be generally V-shaped and the luminaire may be configured such that the light source is situated adjacent to the vertex of the V-shaped reflector. The reflector may optionally be generally V-shaped and the luminaire and the first portion of light emitted by the light source may be configured such that the first portion of light passes through an aperture defined approximately at the vertex of the V-shaped reflector. The luminaire may be configured such that a third portion of light emitted by the light source does not pass through the reflector and is not reflected by the first side of the reflector. The luminaire may optionally comprise a second light source wherein a first portion of light emitted by the second light source passes through the aperture defined in the reflector. The luminaire may also optionally comprise a refractor lens having a central lens portion configured to receive at least a portion of the first portion of light emitted by the light source and the central lens portion may optionally be contoured to refract light. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Aspects and embodiments of the present disclosure may be more fully understood from the following description when read together with the accompanying drawings, which are to be regarded as illustrative in nature, and not as limiting. The drawings are not necessarily to scale, emphasis instead being placed on the principles of the disclosure. In the drawings: 
         FIG. 1  depicts a perspective view of a portion of an example of a luminaire, in accordance with the present disclosure; 
         FIG. 2  depicts a cross section of another example of a luminaire including light ray traces, in accordance with the present disclosure; 
         FIG. 3A  depicts a cross sectional view of an exemplary embodiment of a luminaire, and  FIG. 3B  depicts a perspective view of an end of one exemplary embodiment of a luminaire, both in accordance with the present disclosure; 
         FIG. 4  depicts a cross section view of an example of a luminaire, showing variable design parameters; 
         FIG. 5  is a cutout view of detail A of  FIG. 4 ; 
         FIG. 6  is a cutout view of detail B of  FIG. 4 ; 
         FIG. 7  depicts a cross sectional view of a further embodiment of a luminaire, in accordance with the present disclosure; 
         FIG. 8  is a cutout view of detail A of  FIG. 7 ; and 
         FIG. 9  is a cutout view of detail B of  FIG. 7 . 
     
    
    
     The embodiments depicted in the drawing are merely illustrative. Variations of the embodiments shown in the drawings, including embodiments described herein, but not depicted in the drawings, may be envisioned and practiced within the scope of the present disclosure. 
     DETAILED DESCRIPTION 
     Aspects and embodiments of the present disclosure provide luminaires and lighting structures. Luminaires according to the present disclosure can be used for new installations or to retro-fit existing lighting assemblies and applications, such as those that utilize fluorescent lighting. Use of such lighting techniques can afford reduced energy and maintenance as well as reduced installation time and costs when compared to existing techniques. 
     In exemplary embodiments, alternative light sources to fluorescent lights may be utilized. While the preferred embodiment employs LEDs as light sources, other light sources may also be employed or alternatively used within the scope of the present disclosure. By way of example only, other light sources such as plasma light sources may be used. Further, the term “LEDs” is intended to refer to all types of light emitting diodes including organic light emitting diodes or “OLEDs”. 
     While the luminaire depicted in the Figures is generally applicable to any application that would benefit from strip lighting, it is well-suited, in one example, for application to display cases where the luminaire can be mounted to various of the elongated structural elements of the display case to be hidden from the view of customers viewing items in the display case. One exemplary application is refrigerated food cases such as those commonly found in supermarkets and convenience stores. The depicted luminaire lends itself to application in food cases because its elongated structure facilitates mounting to mullions between doors permitting access to the food case. Such refrigerated cases, can include cases for chilled foods and/or drinks, as well as those used to display frozen foods. Other embodiments may be particularly well-suited for use in display cases for displaying non-food items, e.g., those used to display merchandise goods such as jewelry, watches, and the like. Use in such non-food display cases is advantageous because of the luminaires ability to be mounted to various of the elongated structural components of the display case to illuminate the display case while remaining at least mostly hidden from view of those persons viewing items in the display case. As will be discussed below, the reflector of the present disclosure, while elongated, is applicable to other luminaires such as by using multiple of these reflectors to guide the light from various matrices of light sources. 
       FIG. 1  depicts a perspective view of a portion of an example of a luminaire  100 , in accordance with the present disclosure. Luminaire  100  may include a reflective element (or reflector)  104  (e.g., a V-shaped element as shown), which has one or more apertures  105  defined at its vertex. The one or more apertures  105  are configured to pass some of the light emitted from one or more light sources  108  (e.g., LEDs) associated therewith. One or more reflector mounting structures  106  (e.g., spring clips) may hold the reflective element  104  relative to the light sources  108  depicted as LEDs mounted or formed on a printed circuit board (“PCB”)  112  supported on a frame  114 . The frame  114  may have any suitable size, shape and cross-sectional configuration. Any suitable materials may be used for the described components. Luminaire  100  may, optionally, be used with or include a lens or refractive element such as that described and/or shown in the figures herein. 
     In operation while the one or more light sources  108  of the luminaire  100  depicted in  FIG. 1  are producing light, a first portion of light from each individual light source  108  passes through an associated aperture  105  and a second portion of light is directed laterally relative to the luminaire  100 ; some of which passes directly as emitted from the light source  108  and some of which is reflected by the reflective element  104  after being emitted from the light source  108 , e.g., as shown and described for  FIG. 2 . 
       FIG. 2  depicts a cross section of another exemplary luminaire in accordance with the present disclosure. Luminaire  200  may include a reflector or reflective element  202  and one or more suitable light sources (e.g., LEDs)  204 . A lens or refractive element  206  may also be included. The reflective element  202  defines one or more apertures  208  that are configured to permit passage of a portion of light from the one or more light sources  204 . One or more reflector mounting structures (e.g., spring clips)  210  hold the reflective element  202  relative to the associated light source  204  mounted on or part of a PCB  212  and the PCB  212  is situated on a frame  214 .  FIG. 2  depicts an arbitrary structure  1  to which the luminaire  200  is mounted. 
     Light emanating from the one or more light sources travels though the refractive element in accordance with Snell&#39;s law. For ease of comprehension, light ray traces in the area indicated at reference numeral  3  indicates light passing through the depicted aperture  208  then the lens  206 . Light ray traces in the two areas indicated at reference numeral  2 , indicates light emanating from the one or more light sources  204  and passing laterally through the lens either directly from the light source  204  or after reflecting from the reflective element  202 . 
     The lens or refractive element  206  may include a portion  206   a  that is configured to receive a portion of light from the one or more light sources  204  passing through the one or more apertures  208 . 
     The reflector mounting structure  210 , comprises the same configuration as the reflector mounting structure  106  shown in  FIG. 1 . In the embodiment of the reflector mounting structure  106 ,  210  depicted in  FIGS. 1 and 2  is comprised of first and second receiving legs  106   a  joined at one end to form an inverted V. Each receiving leg  106   a  comprises receiving slots  106   b  on opposing sides to receive the reflector  104 ,  202  as shown. A mounting leg  106   c  extends from each of the receiving legs  106   a  for standing on the PCB  112 ,  212  and allowing the receiving slots  106   b  to hold the reflector  104 ,  202  apart from the PCB  112 ,  212 . Springs clips formed by spring legs  106   d  and  106   e  extend from each mounting leg  106   c  as shown. 
     Frame  214  may have any desired shape. For example, frame  214  preferably includes one or more arms forming channels ( 214   a ,  214   b ) having a partially circular cross-section configured to receive fasteners such as screws, dowels, pins, or the like to assist with assembly or mounting of the luminaire  200 . Frame  214  also preferably includes one or more arms ( 214   c - 214   e ), that are configured to receive and/or contact one or more respective portions of the luminaire  200 . For example, in the embodiment depicted in  FIG. 2 , horizontal arm  214   e  extends outward from the remaining portions of the frame  214 . Arm  214   c  extends upward from arm  214   e  and bends inward to define a mounting structure channel  214   f . Each mounting structure channel  214   f  receives the spring legs  106   d  and  106   e  of the reflector mounting structure  106 ,  210  to secure the reflector mounting structure  210  to the frame  214 . In one embodiment, the spring legs  106   d  and  106   e  are flexed to fit the spring clip they form into the mounting structure channel  214   f . Once the spring clip formed by spring legs  106   d  and  106   e  on each side of the mounting structure  106 ,  210  are secured in their respective mounting structure channels  214   f , the mounting structure  106 ,  210  is secured in place to the frame  114 ,  214 . Furthermore, arm  214   d  extends downward from arm  214   e  to define a lens mounting channel  214   g  to receive a portion of the lens  206  to facilitate securement of the lens  206  to the frame  214 , described in more detail below. In one embodiment, frame  214  is constructed by extrusion to provide the frame  214  with all required rigidity. The frame  214  may be constructed from any suitable material. Examples include, but are not limited to, anodized aluminum, chromed steel, plastic, and the like. 
       FIG. 3A  depicts a cross sectional view of an exemplary embodiment of a luminaire  300 A, in accordance with the present disclosure. Luminaire  300 A may include a refractor, or refractive element,  302 . Refractor  302  may have a central lens portions  303  comprising variable thickness that is configured to distribute or refract light. The central lens portion  303  has a thickness profile and inner surface  303   a  to distribute light from a light source (e.g. LED)  308  in a desired distribution pattern. Refractor  302  may also be referred to as a means for refracting or a refractive means. Luminaire  300 A may also include a reflective element or reflector  304 . The refractive element  302  and the reflective element  304  may together or individually be referred to as light distribution means. 
     Continuing with the description of  FIG. 3A , a mounting structure  306  may hold the reflector  304  relative to a frame  314  and the light source  308  mounted thereon. Frame  314  may be any suitable shape and may be made of any suitable material. For exemplary embodiments, frame  314  may be adapted to fit within the footprint of a pre-existing fluorescent light fixture and, optionally, use the same mounting holes or equipment as the pre-existing fluorescent light fixture to facilitate simple replacement of the pre-existing fluorescent light fixture with the light fixture of the present disclosure. One or more light elements or light sources  308  may be present (one is shown in  FIG. 3A ). The one or more light sources  308  may be positioned adjacent or on a supporting member, e.g., a PCB  312 . For some applications, the one or more light sources may be enclosed in or disposed on a protective die or a mounting element. If one or more of the light sources are enclosed in a die, then the die may have appropriate sections that are transparent or translucent to allow light from the lights source(s) to pass through. 
     With further reference to  FIG. 3A , the reflector  304  can have one or more apertures  305  for passing light from a light source  308  to refractor  302 . In the embodiment depicted in  FIGS. 1 ,  2 ,  3 A,  4 - 5  and  7 , the reflector  104  (in  FIG. 1 ) is configured with a V-shape having first and second arms  304   a  spread at a desired included angle α. In exemplary embodiments the included angle, α, may be 100 degrees; of course other included angles may be used as suitable. In the depicted embodiment, the first and second arms are straight, but could be replaced with curved, stepped or other known reflector configurations to facilitate a desired light distribution, Various surface treatments are also contemplated to provide desired reflectance. 
     Each aperture  305  may be configured (e.g., sized and/or shaped) as desired. For example, a single aperture  305  may be sized to have a length (measured along the vertex of the reflector  304 ) that is or is substantially the length of PCB  312  so as to provide an opening at the vertex of the reflector  304  at each light source along the length of the PCB  312 . In other embodiments, multiple apertures (a plurality of)  305  may be disposed in a desired configuration, e.g., linearly with a constant or varying linear density (e.g., one every foot, one every light source, one every two light sources, etc.). Each individual aperture  305  may have a shape (e.g., of its perimeter) that is selected as desired. For example, an aperture may be elliptical in shape with any degree of eccentricity, circular, rectangular, irregular (any shape) square, triangular, etc. 
     In exemplary embodiments, the central lens portion  303  of refractor  302  may be positioned to receive light from a light source  308  by way of aperture  305 . The luminaire  300 A may be configured such that all light passing through the aperture  305  passes through the central lens portion  303 . Alternatively, luminaire  300 A may be configured such that only a portion of the light passing through the aperture  305  passes through the central lens portion  303 . In yet a further alternative embodiment, the luminaire may comprise a refractor  302  with no central lens portion  303 , in which case the refractor  302  is of the substantially the same thickness in all portions through which light from the light source  308  travels. Refractor  302  may have one or more lateral faces  307 , as shown, which may have varying thicknesses to direct the light passing therethrough, or be of constant thickness to serve primarily as protection for the elements of the luminaire  300 A. Refractor  302  may optionally have inwardly directed members  318 , as shown. In one embodiment not depicted, optional inwardly directed member  318  may be configured so as to clamp the PCB  312  to the frame  314  when the refractor  302  is connected to the frame  314  as depicted in  FIG. 3A . In order to facilitate clamping of the PCB  312  in this manner, the configuration of the optional inwardly directed member  318  must take into consideration no only the configuration of the frame  314 , but also the configuration of the PCB  312 . In yet another alternative embodiment, not depicted, the optional inwardly directed member  318  may be configured so as to clamp down on top of the mounting structure  306 , providing additional stability to the mounting structure  306  and the reflector  304  held by the mounting structure  306 . 
     Refractor  302  may include a central face  315  in which the central lens portion  303  resided, if a central lens portion  303  is present. Central face  315  may be relatively or substantially flat in some embodiments, though it may comprise one or more curvatures or other shapes. The central face  315  may have a desired width, shown by “a,” and may be of any length suitable for the luminaire  300 A and its application. For example, the length of face  315  may be 3 ft., 6 ft., 9 ft., etc. In some embodiments, central face  315  may have a diffusive surface  316  on the interior or exterior thereof, which may facilitate uniformity of light intensity and distribution. The diffusive surface  316  can span the entirety of central face  315  or portions of central face  315  as needed, e.g., as indicated by width “b” in the  FIG. 3A . In exemplary embodiments, diffusive surface  316  can be or include a diffusive acrylic layer approximately 8 mils thick (0.008 in.) covering a desired width of the central face  315 , e.g., 0.7 inch. In one embodiment, the diffusive surface  316  can be provided by co-extruding refractor  302  to comprise a layer of diffusive material (not depicted) at the diffusive surface  316 . In one example, the diffusive layer is 8 mils thick and comprised of an acrylic sold under the trade name Acrylite® 8Ndf23 at the outermost surface of the refractor  302  at the central face  315 . In an alternative embodiment, the diffusive surface  316  can be provided by applying a film of diffusive material to the outside of central face  315 . For example, a length of Scotch tape or other tape may be applied to the outer surface of the central face  315 . In exemplary embodiments, luminaire  300 A may be symmetric with respective to a plane intersecting midline z, as shown. 
     In operation, light source  308  can produce light, which may emanate from the light source  308  in a three-dimensional distribution pattern, e.g., a hemisphere of 271 steradians of solid angle, or a cone of other given included solid angle, etc. Of the light constituting this distribution, some may travel directly out of the refracting element  302 , for example, through lateral face  307 , as shown by representative rav trace R 1 . Some of the light from the light source  308  may be reflected by reflective element  304  and then pass through refractive element  302  as shown by representative ray trace R 2 . Still, another portion of the light from light source  308  may pass through aperture  305  and then through refractive element  302 , e.g., through contoured portion  303 , as shown by representative ray trace R 3 . Ray traces R 1 -R 3  are merely representative, and other optical paths may occur, e.g., ones including total internal reflection in accordance with Snell&#39;s law. 
     Refractor  302  may be made from any suitable transparent, substantially transparent, and/or translucent material, e.g., glass, Lexan, or acrylic such as sold under the trade name Optix® CA-1000E, or suitable functional equivalent. The material used for the refractor  302  may have any suitable clarity. In exemplary embodiments, the material may be about 85% transmissive, though higher values, e.g., 90% or higher, may be preferred. The diffusive surface  316  or the central face  315  and exemplary materials therefore are discussed above. Any suitable reflective material may be used for reflector  304 . Examples include, but are not limited to, specular aluminum, chromed steel, aluminized or aluminum-coated plastic, painted plastic, and the like. In exemplary embodiments, a specular aluminum sheet is used that is about 95% reflective; of course, other values of reflectivity (e.g., 70%, 85%, 90% or thereabouts) may be used or implemented for a reflective element. Alanod Miro—4400 GP is considered suitable. If the reflector  304  is comprises of a metal, the reflector can be constructed by one or more stamping operations to form the apertures  305  and one or more bending operations to form the desired V-shape. It is further noted that the reflector  304  shape need not be an absolute V. Rather various variations and deviations from the absolute V, such as curved legs extending from the vertex, are contemplated. 
     In an exemplary embodiment, light source(s)  308  may include one or more LEDs suitable for the light distribution and intensity necessary for the application. The light sources  308  could be LEDs made commercially available by Osram Opto Semiconductor, Model Oslon LUW CP7P-LXLY-7P7E. Other suitable lights sources  308  may include, but are not limited to, Cree XPEWHT-01-0000-00EC, Philips LumiLEDS Rebel LXML-PWN1-0100, or suitable equivalent. The length (e.g., into or out of the plane of  FIG. 3A ) of an aperture may be about 0.5 inches in exemplary embodiments. The approximate range of angular rays emanating from the apertures  305  may be 45 degrees, plus or minus five degrees, for exemplary embodiments. 
     In exemplary embodiments, luminaire  300 A may have a rectangular shape in plan view and may be configured for retrofitting into a lighting application that previously included fluorescent lighting. Of course, luminaire  300 A may have other shapes in plan view, e.g., circular, oval, square, etc. 
     For use in illuminating a desired area, the luminaires of the present disclosure may be mounted to a structure or surface by any suitable mounting devices, structures, fasteners, or the like. 
       FIG. 3B  depicts a perspective view of a portion of a luminaire  300 B, similar to luminaire  300 A of  FIG. 3A , with a mounting bracket  301  for mounting the luminaire to a structure, e.g., an underlying mullion, support structure, or the like. The mounting bracket  301  may be formed from any suitable material, e.g., sheet metal, plastic, or the like. The end cap  301  may include one or more holes or apertures. For example, apertures  330  and  332  may be present for accommodating a power chord. For further example, one or more apertures may be formed in the end cap for use with fasteners, e.g., screws, as shown by  334  and  336 . An end cap  303  may be present to cover the mounting bracket  301 . 
     For operation, in some applications, a power cable/chord from the luminaire  300 B may be run through a hole (e.g.,  332 ) in the mounting bracket  301  out the back and through a hole formed into an underlying structures such as a cooler mullion to which the luminaire  300 B is to be mounted. The other end (not shown) of the luminaire  300 B may optionally include a hole, e.g., a breather hole for venting the interior of the fixture. The cooler mullion can act as a passageway for the power cable and possible mounting location of a related power supply. The luminaire  300 B may be attached (e.g., screwed) into place, e.g., on the cooler mullion, top and bottom. The end cap (e.g., a molded plastic cap)  303  may be snapped over this mounting bracket  301  to hide the screws, cables, etc. The back of the luminaire  300 B and the cap  303  may rest flush against an underlying structure, e.g., cooler mullion. In this way, all potential crevices may be hidden or minimized, e.g., for NSF compliance. 
       FIG. 4  depicts a cross section view of a further example of a luminaire  400 , showing variable design parameters that may be selected or specified as desired, e.g., for a particular installation or application. As shown, luminaire  400  may include a refractor  402  with a central lens portion  403  having a curved surface  403   a . Luminaire  400  can also include a reflector  404 . Reflector  404  may have one or more lateral reflective faces  404   a . Reflector  404  may have one or more apertures  405  that are configured to allow light to pass through the reflective element  404 . Apertures  405  may be holes, e.g., as drilled or stamped through reflective element  404 , or may be portions of reflective element that are transparent or translucent instead of reflective, for example, portions that are not painted with reflective paint. Reflector  404  may be held by a support member (not depicted in  FIG. 4 ). One or more light sources  408  may be present and configured adjacent to aperture  405 , e.g., disposed on support surface or PCB  412 , as shown. The refractor  402  may also have one or more lateral faces  407 , as shown. For some applications, lateral face(s)  407  may have a desired radius of curvature “R.” For example, lateral faces  407  may have a radius of curvature relative to the optical center of one or more light sources  408 . R may have any suitable value (e.g., 0.5 in., 0.590 in., 1.0 in., etc). 
     For luminaire  400 , a number of design parameters (c-j) are shown, which may be selected as desired for various applications. The design parameters shown include the following: (c)—the distance or height between the top of the refractive element  402  at the central face  415  and the optical center  408 ; (d)—the distance or height between the lowest portion of the curved surface  403   a  of the central lens portion  403 ; (e)—the distance or height between the optical center of the light source  408  and the proximal portion of the apex of the reflector  404  at the aperture  405 ; (f)—the thickness of the central face  415 ; (g)—angle between the faces  404   a  of the reflector  404  and the horizontal reference plane; (h)—the distance or height between the optical center of the light source  408  and the distal or top portion of the optical source housing, e.g., LED package; (i)—angular range of rays emanating from aperture (either solid angle or 2D angle); (j)—distance or diameter across trench or circle formed by the curved surface  403   a  of the central lens portion  403 ; and (k)—distance or length of lateral reflective surface(s)  404   a.    
       FIG. 5  is a cutout view of detail A of  FIG. 4 , while  FIG. 6  is a cutout view of detail B of  FIG. 4 .  FIG. 5  shows the following design parameters: (l)—height between optical center of light source  408  and the aperture  405 , on the distal side, away from light source  408 ; (m)—width of aperture  405 , on the distal side, away from light source  408 ; (n)—half-distance or radius of aperture  405 , on distal side, away from light source  408 ; (o)—radius of curvature of fillet between lateral reflective faces  404   a ; and (p)—thickness of lateral reflective faces  404   a.    
       FIG. 6  shows the central lens portion  403  with a curved surface  403   a  that is symmetrical about a center line. Curved surface  403   a  may subtend any suitable angle, “q” for various applications. In exemplary embodiments, the profile of curved surface  403   a  may be an elliptical profile, e.g., approximated by the curve y=0.706x 0.664 ; other curves and and/or profiles may of course be used. For the profile of curved surface  403   a , two flats may be angled toward a vertex, e.g., vertex  601  in  FIG. 6  finished by a smooth curve or fillet. Of course, any other desired profile may be used for curved surface  403   a , e.g., saw-tooth pattern, sinusoidal, etc. 
     In an exemplary embodiment, luminaire  400  as shown in  FIGS. 4-6  may have the following values for design parameters (c-p): 
     
       
         
               
               
               
             
           
               
                   
                   
               
             
             
               
                   
                 c 
                 0.450″ 
               
               
                   
                 d 
                 0.334″ 
               
               
                   
                 e 
                 0.092″ 
               
               
                   
                 f 
                 0.050″ 
               
               
                   
                 g 
                 40° 
               
               
                   
                 h 
                 0.062″ 
               
               
                   
                 i 
                 45° 
               
               
                   
                 j 
                 0.240″ 
               
               
                   
                 k 
                 0.407″ 
               
               
                   
                 l 
                 0.122″ 
               
               
                   
                 m 
                 0.048″ 
               
               
                   
                 n 
                 0.024″ 
               
               
                   
                 o 
                 R = 0.03″ 
               
               
                   
                 p 
                 0.020″ 
               
               
                   
                 q 
                 112°  
               
               
                   
                   
               
             
          
         
       
     
       FIG. 7  depicts a cross sectional view of a further embodiment of a luminaire  700 , in accordance with the present disclosure.  FIG. 8  is a cutout view of detail A of  FIG. 7 , while  FIG. 9  is a cutout view of detail B of  FIG. 7 . In operation, luminaire  700  can distribute light similarly to luminaire  400  of  FIG. 4 . 
     As shown, luminaire  700  may include a refractor  702  and a reflector  704 . Refractor  702  may include a central lens portion  703  that has a profiled surface  703   a . Reflector  704  may include one or more lateral reflective faces  704   a . The included angle between the lateral reflective faces  704   a  may be selected as desired for the sought light distribution. For example, the angle may be about 100 degrees, about 90 degrees, about 95 degrees, about 110 degrees, 80 degrees, about 105 degrees, etc. Luminaire  700  may also include a frame element  706  with one or more secondary reflective surfaces  706   a , as indicated. Frame element  706  may also have a base  706   b , as shown. Reflective element  704  may include one or more apertures  707 . Aperture(s)  707  may be configured adjacent to, and pass or receive light from, one or more light sources  708 . Light source(s)  708  may be positioned on a support surface  712 , e.g., a PCB. 
     With continued reference to  FIG. 7 , refractor  702  may include a central lens portion  703  having a profiled surface  703   a . The profiled surface  703   a  may have any desired surface profile. In exemplary embodiments, the contour or shape of profiled surface  703   a  may facilitate even or roughly even light intensity distribution of light outside of the luminaire  700  in a desired area or region. Examples include but are not limited to concentric circles or ovals or ellipses, with a saw tooth or curved profile in cross-section. Refractive element  702  may also include a shaped portion  705  that has a varying thickness in cross section. As shown in  FIG. 7 , the shaped portion may  705  facilitate reception of the reflective element  704  by the refractive element  702 . 
     As further shown in  FIG. 7 , refractor  702  may be shaped to provide a viewing angle “r” of desired size or range of sizes. For example, in exemplary embodiments, refractor  702  may have a bend at or near shaped portion  705  such that the viewing angle, r, is 5° or approximately 5°; which may facilitate hiding, or preventing direct viewing of, light source  708  by people in an area or region outside of the luminaire  700 . 
     In exemplary embodiments, luminaire  700  has a rectangular shape in plan view and may be configured for retrofitting into a lighting application that previously included fluorescent lighting. Of course, luminaire  700  may have other shapes in plan view, e.g., circular, oval, square, etc. 
     In an exemplary embodiment, the lateral faces  104   a  are 0.517 inches long, the viewing angle is 7 degrees, base  706   b  is 1.136 inches wide, the secondary reflective surfaces  706   a  have a radius of curvature of 1.250 inches, and overall frame width is 2.821 inches, with a height to the top of the frame of 0.490 inches, while the overall height of the luminaire is 0.635 inches. 
     In another exemplary embodiment, luminaire  700  as shown in  FIGS. 7-9  may have the following values for design parameters (r-bb): 
     
       
         
               
               
               
             
           
               
                   
                   
               
             
             
               
                   
                 R 
                  5° 
               
               
                   
                 S 
                 35° 
               
               
                   
                 T 
                 32° 
               
               
                   
                 U 
                 27° 
               
               
                   
                 V 
                 22° 
               
               
                   
                 W 
                 15° 
               
               
                   
                 X 
                 22° 
               
               
                   
                 Y 
                 18° 
               
               
                   
                 Z 
                 13° 
               
               
                   
                 aa 
                  8° 
               
               
                   
                 bb 
                  4° 
               
               
                   
                   
               
             
          
         
       
     
     The LEDs of this exemplary embodiment can be of any kind, color (e.g., emitting any color or white light or mixture of colors and white light as the intended lighting arrangement requires) and luminance capacity or intensity, preferably in the visible spectrum. Color selection can be made as the intended lighting arrangement requires. In accordance with the present disclosure, LEDs can comprise any semiconductor configuration and material or combination (alloy) that produce the intended array of color or colors. The LEDs can have a refractive optic built-in with the LED or placed over the LED, or no refractive optic; and can alternatively, or also, have a surrounding reflector, e.g., that re-directs low-angle and mid-angle LED light outwardly. In one suitable embodiment, the LEDs are white LEDs each comprising a gallium nitride (GaN)-based light emitting semiconductor device coupled to a coating containing one or more phosphors. The GaN-based semiconductor device can emit light in the blue and/or ultraviolet range, and excites the phosphor coating to produce longer wavelength light. The combined light output can approximate a white light output. For example, a GaN-based semiconductor device generating blue light can be combined with a yellow phosphor to produce white light. Alternatively, a GaN-based semiconductor device generating ultraviolet light can be combined with red, green, and blue phosphors in a ratio and arrangement that produces white light (or another desired color). In yet another suitable embodiment, colored LEDs are used, such are phosphide-based semiconductor devices emitting red or green light, in which case the LED assembly produces light of the corresponding color. In still yet another suitable embodiment, the LED light board may include red, green, and blue LEDs distributed on the printed circuit board in a selected pattern to produce light of a selected color using a red-green-blue (RGB) color composition arrangement. In this latter exemplary embodiment, the LED light board can be configured to emit a selectable color by selective operation of the red, green, and blue LEDs at selected optical intensities. Clusters of different kinds and colors of LED is also contemplated to obtain the benefits of blending their output. 
     Each PCB, e.g.,  212  of  FIG. 2 , can include an onboard driver to run the light sources, e.g., LEDs, with a desired current. For example, a current suitable for an LED may be used. For example, a representative current range could include, but is not limited to about 250 mA to about 800 mA; one exemplary current is about 350 mA and another is 600 mA. A circuit board can have a bus, e.g., a 24V DC bus, going from one end to the other. Other voltages may of course be used for a bus. Any suitable number of suitable LEDs can be disposed on a light strip board. In one illustrative example, two (2) Rebel LEDs (LUXEON® Rebel LEDs as made commercially available by the Philips Lumileds Lighting Company)—per foot, operational at 80 Lumens minimum may be employed with the luminaire of the present disclosure. Other suitable LEDs or alternative light sources and output values may be used within the scope of the present disclosure. 
     In exemplary embodiments, a lens or refractive element may be made of an extrusion of polycarbonate or acrylic. Such polycarbonate or other plastic may be selected as desired and may possess a desired degree of transparency (and, therefore, opaqueness) and may have a desired color. 
     In further embodiments, the formation of at least one support member can include forming a circuit board supporting face in the support member that is configured and arranged to support the circuit board (and attached light sources) in a desired orientation, e.g., as when the related assembly is placed in a retrofit application. A visual cutoff shield may also be mounted to a support member for some applications. 
     Accordingly, lighting assemblies and luminaires according to the present disclosure can distribute light from one or more light sources in desired ways. Exemplary embodiments of lighting techniques according to the present disclosure can be used to retro-fit existing lighting assemblies and applications that were initially constructed to utilize fluorescent lighting. Such lighting according to the present disclosure can afford reduced energy, maintenance, and installation costs, as well as reduced installation time when compared to existing techniques. As described previously, exemplary embodiments of the present disclosure may utilize LEDs as light sources. 
     While certain embodiments have been described herein, it will be understood by one skilled in the art that the methods, systems, and apparatus of the present disclosure may be embodied in other specific forms without departing from the spirit thereof. For example, while aspects and embodiments herein have been described in the context of retrofit applications for refrigerated display cases, the present disclosure is not limited to such; for example, embodiments of the present disclosure may be utilized generally for any light distribution applications. 
     Accordingly, the embodiments described herein, and as claimed in the attached claims, are to be considered in all respects as illustrative of the present disclosure and not restrictive.