Abstract:
The present disclosure is directed to inventive methods and apparatus for a lighting unit having a plurality of substantially linearly arranged solid state light sources ( 34, 134, 234, 334 ). A first reflector ( 40, 140, 240, 340 ) and a second reflector ( 50, 150, 250, 350 ) flank the solid state light sources ( 34, 134, 234, 334 ). A lens ( 60, 160, 260, 360 ) is provided over and spaced apart from a plurality of the solid state light sources ( 34, 134, 234, 334 ).

Description:
TECHNICAL FIELD 
       [0001]    The present invention is directed generally to a lighting unit having a plurality of substantially linearly arranged solid state light sources. More particularly, various inventive methods and apparatus disclosed herein relate to a lighting unit having a plurality of linearly arranged LEDs, a first and second reflector flanking the LEDs, and a lens provided over and spaced apart from the LEDs. 
       BACKGROUND 
       [0002]    Digital lighting technologies, i.e. illumination based on semiconductor light sources, such as light-emitting diodes (LEDs), offer a viable alternative to traditional fluorescent, HID, and incandescent lamps. Functional advantages and benefits of LEDs include high energy conversion and optical efficiency, durability, lower operating costs, and many others. Recent advances in LED technology have provided efficient and robust full-spectrum lighting sources that enable a variety of lighting effects in many applications. 
         [0003]    Many lighting fixtures have been designed that implement LEDs to reap one or more of the advantages and benefits of LEDs. For example, some lighting fixtures have been designed that implement a plurality of LEDs, with each individual LED having an associated LED optic thereover. For example, each individual LED may have an individual reflector that surrounds the LED and reflects light output from the LED into a desired beam distribution and an associated individual lens coupled to the reflector that refracts light output from the LED in a desired direction. The LEDs may be appropriately positioned and each LED optic may be appropriately paired with a desired of the LEDs in order to obtain a desired light output from the lighting fixture. While such lighting fixtures generally enable a desired light output to be obtained, they may cause individual imaging of each optic on the target illumination area, thereby causing a non-uniform illumination pattern. Likewise, such lighting fixtures may employ fixed, unremovable LED optics, thereby preventing the lighting fixtures from being easily adapted to provide a selected of a plurality of distinct optical outputs. 
         [0004]    Thus, there is a need in the art for a lighting unit having a plurality of solid state light sources (e.g., LEDs), which has reduced imaging of individual LED optics on the target illumination area and which can provide a plurality of distinct optical outputs. 
       SUMMARY 
       [0005]    The present disclosure is directed to inventive methods and apparatus for a lighting unit having a plurality of substantially linearly arranged solid state light sources such as, for example, LEDs. More particularly, various inventive methods and apparatus disclosed herein relate to a lighting unit having a plurality of linearly arranged LEDs, a first and second reflector flanking the LEDs, and a lens provided over and spaced apart from the LEDs. Optionally, the lens may be removably coupled over the LEDs, thereby allowing for interchanging with a lens having alternative optical characteristics. For example, a lens that has optical characteristics that provide for a spot target narrow distribution may be interchanged with a lens that provides for a distinct linear spot target distribution. The lens may be formed from a single longitudinally extending piece or may include a plurality of lens pieces. For example, the lens may include a plurality of longitudinally extending lens pieces and/or a plurality of non-longitudinally extending lens pieces that collectively form a longitudinally extending lens. Each lens piece may be provided over a single or multiple of the LEDs. The lighting unit may optionally be designed to enable the orientation of the LEDs to be selectively adjustable by a user. The present disclosure may provide a LED lighting unit that may be manipulated by a user (e.g., by changing out the lens and/or adjusting the orientation of the LEDs) to provide a desired optical output from the LED light unit, thereby allowing for a variety of lighting configurations from the lighting unit. 
         [0006]    Generally, in one aspect, a LED-based lighting unit is provided that includes a plurality of substantially linearly arranged LEDs, a longitudinally extending first reflector, and a longitudinally extending second reflector. The longitudinally extending first reflector is along a first side of the LEDs and has a first generally concave reflective surface extending outward and away from adjacent the LEDs. The longitudinally extending second reflector is along a second side of the LEDs and has a second generally concave reflective surface extending outward and away from adjacent the LEDs. The lens is provided over and spaced apart from a plurality of the LEDs and extends between the first reflector and the second reflector. The lens is removably coupled over the LEDs. 
         [0007]    In some embodiments the lens has a substantially planar first side facing the LEDs and a non-planar second side opposite the first side. In some versions of those embodiments the first concave reflective surface and the second concave reflective surface have substantially similar concavities. In some versions of those embodiments the first concave reflective surface extends outward a first distance from the LEDs and the second concave reflective surface extends outward a second distance from the LEDs; the second distance being at least one and a half times the first distance. In some versions of those embodiments the first concave reflective surface extends away from the LEDs approximately the same distance as the second concave reflective surface. 
         [0008]    In some embodiments the lens is removably coupled to the first reflector and the second reflector. 
         [0009]    In some embodiments the lens is a singular longitudinally extending piece provided over each of the plurality of LEDs. 
         [0010]    In some embodiments the lens includes a plurality of adjacent individual lens pieces. In some versions of those embodiments each of the individual lens pieces is provided over a single of the LEDs. 
         [0011]    Generally, in another aspect a LED-based lighting unit includes a support surface, a plurality of LEDs, a longitudinally extending first reflector, a longitudinally extending second reflector, and a lens. The plurality of LEDs are coupled to the support surface in a substantially linear arrangement. The longitudinally extending first reflector is coupled to the support surface on a first side of the LEDs and has a first generally concave reflective surface extending outward and away from adjacent the LEDs. The longitudinally extending second reflector is along a second side of the LEDs and has a second generally concave reflective surface extending outward and away from adjacent the LEDs. The lens is provided over and spaced apart from each of the LEDs. The lens extends between the first reflector and the second reflector and has a substantially planar first side facing the LEDs and a non-planar second side opposite the first side. 
         [0012]    In some embodiments the lens is removably coupled over the LEDs. In some versions of those embodiments the lens is removably coupled to the first reflector and the second reflector. 
         [0013]    In some embodiments the lens includes at least one longitudinally extending lens piece provided over each of the plurality of LEDs. In some versions of those embodiments the lens includes two the longitudinally extending lens piece, each the lens piece provided over at least a portion of each of the plurality of LEDs. 
         [0014]    In some embodiments the lens includes a plurality of lens pieces. In some versions of those embodiments each of the lens pieces is provided over a single of the LEDs. 
         [0015]    In some embodiments the support surface is repositionable to a plurality of user selectable orientations. 
         [0016]    Generally, in another aspect A LED-based lighting unit system includes a plurality of LEDs, a longitudinally extending first reflector, a longitudinally extending second reflector, and a plurality of lens having unique optical characteristics. The LEDs are substantially linearly arranged and the first reflector and the second reflector flank the LEDs. The first reflector has a first reflective surface extending outward and away from adjacent the LEDs. The second reflector has a second reflective surface extending outward and away from adjacent the LEDs. Each lens may be removably coupled over and spaced apart from a plurality of the LEDs and extend between the first reflector and the second reflector. 
         [0017]    As used herein for purposes of the present disclosure, the term “LED” should be understood to include any electroluminescent diode or other type of carrier injection/junction-based system that is capable of generating radiation in response to an electric signal. Thus, the term LED includes, but is not limited to, various semiconductor-based structures that emit light in response to current, light emitting polymers, organic light emitting diodes (OLEDs), electroluminescent strips, and the like. In particular, the term LED refers to light emitting diodes of all types (including semi-conductor and organic light emitting diodes) that may be configured to generate radiation in one or more of the infrared spectrum, ultraviolet spectrum, and various portions of the visible spectrum (generally including radiation wavelengths from approximately 400 nanometers to approximately 700 nanometers). It should also be understood that the term LED does not limit the physical and/or electrical package type of an LED. 
         [0018]    The term “light source” should be understood to refer to any one or more of a variety of radiation sources, including, but not limited to, LED-based sources (including one or more LEDs as defined above), incandescent sources (e.g., filament lamps, halogen lamps), fluorescent sources, phosphorescent sources, high-intensity discharge sources (e.g., sodium vapor, mercury vapor, and metal halide lamps), lasers, other types of electroluminescent sources, pyro-luminescent sources (e.g., flames), candle-luminescent sources (e.g., gas mantles, carbon arc radiation sources), photo-luminescent sources (e.g., gaseous discharge sources), cathode luminescent sources using electronic satiation, galvano-luminescent sources, crystallo-luminescent sources, kine-luminescent sources, thermo-luminescent sources, triboluminescent sources, sonoluminescent sources, radioluminescent sources, and luminescent polymers. 
         [0019]    The term “lighting fixture” is used herein to refer to an implementation or arrangement of one or more lighting units in a particular form factor, assembly, or package. The term “lighting unit” is used herein to refer to an apparatus including one or more light sources of same or different types. A given lighting unit may have any one of a variety of mounting arrangements for the light source(s), enclosure/housing arrangements and shapes, and/or electrical and mechanical connection configurations. Additionally, a given lighting unit optionally may be associated with (e.g., include, be coupled to and/or packaged together with) various other components (e.g., control circuitry) relating to the operation of the light source(s). An “LED-based lighting unit” refers to a lighting unit that includes one or more LED-based light sources as discussed above, alone or in combination with other non LED-based light sources. 
         [0020]    It should be appreciated that all combinations of the foregoing concepts and additional concepts discussed in greater detail below (provided such concepts are not mutually inconsistent) are contemplated as being part of the inventive subject matter disclosed herein. In particular, all combinations of claimed subject matter appearing at the end of this disclosure are contemplated as being part of the inventive subject matter disclosed herein. It should also be appreciated that terminology explicitly employed herein that also may appear in any disclosure incorporated by reference should be accorded a meaning most consistent with the particular concepts disclosed herein. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0021]    In the drawings, like reference characters generally refer to the same parts throughout the different views. Also, the drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the invention. 
           [0022]      FIG. 1  illustrates a bottom front exploded perspective view of a first embodiment of a lighting unit. 
           [0023]      FIG. 2  illustrates a rear plan view of the first embodiment of the lighting unit. 
           [0024]      FIG. 3  illustrates a section view of the first embodiment of the lighting unit taken along the section line  3 - 3  of  FIG. 2 . 
           [0025]      FIG. 4  illustrates a bottom front exploded perspective view of a second embodiment of a lighting unit. 
           [0026]      FIG. 5  illustrates a front plan view of the second embodiment of the lighting unit. 
           [0027]      FIG. 6  illustrates a section view of the second embodiment of the lighting unit taken along the section line  6 - 6  of  FIG. 5 . 
           [0028]      FIG. 7  illustrates a bottom front exploded perspective view of a third embodiment of a lighting unit. 
           [0029]      FIG. 8  illustrates a front plan view of the third embodiment of the lighting unit. 
           [0030]      FIG. 9  illustrates a section view of the third embodiment of the lighting unit taken along the section line  9 - 9  of  FIG. 8 . 
       
    
    
     DETAILED DESCRIPTION 
       [0031]    In the following detailed description, for purposes of explanation and not limitation, representative embodiments disclosing specific details are set forth in order to provide a thorough understanding of the claimed invention. However, it will be apparent to one having ordinary skill in the art having had the benefit of the present disclosure that other embodiments according to the present teachings that depart from the specific details disclosed herein remain within the scope of the appended claims. Moreover, descriptions of well-known apparatuses and methods may be omitted so as to not obscure the description of the representative embodiments. Such methods and apparatuses are clearly within the scope of the claimed invention. For example, various embodiments of the apparatus disclosed herein are particularly suited for installation in a ceiling grid, such as, for example, a ceiling grid employing a low-voltage ceiling grid power supply system. Accordingly, for illustrative purposes, the claimed invention is discussed in conjunction with a lighting unit that may be adapted for such installation. However, other configurations and applications of the apparatus are contemplated without deviating from the scope or spirit of the claimed invention. 
         [0032]    Referring initially to  FIG. 1  through  FIG. 3 , a first embodiment of a lighting unit  110  is shown. The lighting unit  110  has a plurality of LEDs  134  mounted in a linear arrangement on a circuit board  132 . The circuit board  132  may be coupled to a support surface  112  of a heatsink  110 . A plurality of heat fins  114  extend rearwardly from the support surface of the heatsink  110  and assist in dissipation of heat generated by the LEDs  134 . Optionally, a thermal material (e.g., thermal paste and/or a thermal pad) may be interposed between the circuit board  132  and the support surface  112 . In alternative embodiments the LEDs  134  may each be mounted on individual circuit boards or may be mounted directly to the support surface  112 . 
         [0033]    A longitudinally extending first reflector  140  is provided along a first side of the LEDs  134 . The first reflector  140  is a singular piece and extends longitudinally from a first end  141  to a second end  142  thereof along each of the LEDs  134 . In alternative embodiments the first reflector  140  may comprise multiple reflector pieces and/or may extend along less than all of the LEDs  134 . The first reflector  140  has an inner concave surface  144  that extends from adjacent the LEDs  134  in a direction outward and away from the LEDs  134  toward a flange  146  of the first reflector  140 . The away direction is the direction generally perpendicular to the surface on which the LEDs  134  are mounted. In other words, in the first embodiment of the lighting unit  10  the away direction is generally perpendicular to the surface of the circuit board  132  to which the LEDs  134  are mounted. The outward direction is the direction peripheral of the LEDs  134 . In other words, the outward direction is generally perpendicular to the away direction. 
         [0034]    A longitudinally extending second reflector  150  is provided along a second side of the LEDs  134 . The second reflector  150  is a singular piece and extends longitudinally from a first end  151  thereof to a second end  152  thereof along each of the LEDs  134 . In alternative embodiments the second reflector  150  may comprise multiple reflector pieces and/or may extend along less than all of the LEDs  134 . The second reflector  150  has an inner concave surface  154  that extends from adjacent the LEDs  134  in a direction outward and away from the LEDs  134 . The inner concave surface  154  and the inner concave surface  144  extend away from the LEDs  134  approximately the same distance. However, the inner concave surface  154  extends outward from the LEDs  134  approximately twice the distance as the inner concave surface  144 . Accordingly, the inner concave surface  154  has a greater degree of curvature than the inner concave surface  144 . 
         [0035]    First reflector  140  and/or second reflector  150  may, in some embodiments be coupled to the circuit board  132 . For example, in some embodiments the first reflector  140  and/or the second reflector  150  may be fixedly or removably coupled to the circuit board  132  using mechanical affixation methods, including, but not limited to adhesives, welding, soldering, prongs, fasteners, and/or structure that may extend from first reflector  140 , second reflector  150 , and/or circuit board  132 . In some other embodiments the first reflector  140  and/or the second reflector  150  may be coupled to a frame  120  using mechanical affixation methods. The frame  120  may be coupled to the heatsink  110  and includes a frame sidewall  122  that surrounds the first reflector  140 , the second reflector  150 , the LEDs  134 , and the circuit board  132 . A first flange  124  and a second flange  125  extend perpendicular to and peripherally of the frame sidewall  122  and are substantially co-planar with the edges of first reflector  140  and second reflector  150  that are distal the circuit board  132 . The frame  120  may be relatively small in some embodiments such as, for example, five inches in longitudinal length and one inch in latitudinal width. Optionally, the lighting unit  10  may be adapted to be attached to a ceiling grid such as, for example, a low voltage powered ceiling grid system currently being advanced by the Emerge Alliance. 
         [0036]    A longitudinally extending lens  160  is provided over and spaced apart from the LEDs  134 . The lens  160  may be constructed from a proper optical medium. For example, in some embodiments the lens  160  may be molded optical grade acrylic. The lens  160  is longitudinally extending from a first end  161  thereof to a second end  162  thereof. A substantially planar first side  167  of the lens  160  extends between the first end  161  and second end  162  and faces the LEDs  134 . The first side  167  is substantially co-planar with the circuit board  132 . A non-planar second side  166  is provided opposite the first side  167  and extends between the first end  161  and the second end  162 . A front longitudinal side  165  and a rear longitudinal side  164  extend between the first side  167  and the second side  166 . The rear longitudinal side  164  and the front longitudinal side  165  are oriented substantially perpendicular to the first side  167 . The front longitudinal side  165  is taller (in a direction from the first side  167  to the second side  166 ) than respective longitudinal locations of the rear longitudinal side  164 . The lens  160  extends between and beyond the first reflector  140  and the second reflector  150 . The lens  160  may be coupled to the flange  146 , the edge of the second reflector  150 , and/or portions of the frame utilizing an adhesive, for example. In other embodiments the lens  160  may be coupled to the first reflector  140 , the second reflector  150 , and/or the frame  120  using alternative mechanical affixation methods, including, but not limited to welding, soldering, prongs, fasteners, and/or structure that may extend from first reflector  140 , second reflector  150 , and/or circuit board  132 . Optionally, the mechanical affixation methods may allow for the lens  160  to be removably coupled to respective structure. A Gaussian filter  169  may optionally extend between the first reflector  140  and the second reflector  150  and be interposed between the LEDs  134  and the lens  160 . 
         [0037]    In operation, appropriate electrical connections (e.g. from a LED driver and/or a low voltage ceiling grid) may be made to LEDs  134 . Some light output from LEDs  134  will be directly incident on Gaussian filter  169  and then lens  160 . Some light output will first reflect off first reflector  140 , second reflector  150 , and/or an interior facing portion of frame sidewall  122  and redirected toward filter  169  and then lens  160 . The first reflector  140 , second reflector  150 , and the lens  160  are configured for wall washing. A majority of the light emitted from the LEDs  134  will be directed out front longitudinal side  165  and second side  166  and directed generally toward an area that is in a direction that front longitudinal side  165  faces. As will be understood by one of ordinary skill in the art, having had the benefit of the present disclosure, variations may be made to the first reflector  140 , second reflector  150 , and or lens  160  to achieve a desired light output that varies from the light output achieved by lighting unit  110 . For example, in some embodiments the degree of curvature of the first concave surface  144  may be decreased to increase forward throw of light output and/or the contour of second surface  166  may be altered to achieve a different amount of internal reflection and/or different characteristics of internal reflection. 
         [0038]    Referring to  FIG. 4  through  FIG. 6 , a second embodiment of a lighting unit  210  is shown. The lighting unit  210  has a plurality of LEDs  234  mounted in a linear arrangement on a circuit board  232 . The circuit board  232  may be coupled to a support surface  212  of a heatsink  210 . Optionally, a thermal material (e.g., thermal paste and/or a thermal pad) may be interposed between the circuit board  232  and the support surface  212 . In alternative embodiments the LEDs  234  may be mounted directly to the support surface  212 . The heatsink  210  has a ball socket shaft  215  extending from a rear surface thereof that is coupled to a ball socket  216 . The ball socket  216  is movably coupleable to a ball  206  that is coupled to a ball shaft  205  extending from an attachment piece  204 . The attachment piece  204  may be configured for installation in a ceiling grid such as, for example, a low voltage powered ceiling grid system. The movable coupling between the ball  206  and ball socket  216  enables the heatsink  210  and the attached circuit board  232  to be movably positioned at a desired orientation by a user. In alternative embodiments one or more hinges may be utilized in lie of the ball  206  and ball socket  216  to enable circuit board  232  to be movably positioned at a desired orientation by a user. 
         [0039]    A longitudinally extending first reflector  240  is provided along a first side of the LEDs  234 . The first reflector  240  is a singular piece and extends longitudinally from a first end  241  to a second end  242  thereof along each of the LEDs  234 . In alternative embodiment the first reflector  240  may comprise multiple reflector pieces and/or may extend along less than all of the LEDs  234 . The first reflector  240  has an inner concave surface  244  that extends from adjacent the LEDs  234  in a direction outward and away from the LEDs  234  toward a flange  246  of the first reflector  240 . 
         [0040]    A longitudinally extending second reflector  250  is provided along a second side of the LEDs  234 . The second reflector  250  is a singular piece and extends longitudinally from a first end  251  thereof to a second end  252  thereof along each of the LEDs  234 . In alternative embodiments the second reflector  250  may comprise multiple reflector pieces and/or may extend along less than all of the LEDs  234 . The second reflector has an inner concave surface  254  that extends from adjacent the LEDs  234  in a direction outward and away from the LEDs  234  toward a flange  256  of the second reflector  250 . The inner concave surface  254  and the inner concave surface  244  share a substantially common degree of curvature and extend away from the LEDs  234  approximately the same distance and outward from the LEDs  234  approximately the same distance. 
         [0041]    First reflector  240  and/or second reflector  250  may, in some embodiments be coupled to circuit board  232 . For example, in some embodiments the first reflector  240  and/or the second reflector  250  may be coupled to the circuit board  232  using mechanical affixation methods. In some other embodiments the first reflector  240  and/or the second reflector  250  may be coupled to the heatsink  210  using mechanical affixation methods. Although not depicted, an end plate may optionally be placed between first ends  241  and  251  of first and second reflectors  240  and  250  and/or second ends  242  and  252  of first and second reflectors  240  and  250 . The end plate may optionally be interiorly reflective or semi-reflective. 
         [0042]    A longitudinally extending lens  260  is provided over and spaced apart from the LEDs  234 . The lens  260  is longitudinally extending from a first end  261  thereof to a second end  262  thereof. A substantially planar first side  267  of the lens  260  extends between the first end  261  and second end  262  and faces the LEDs  234 . The first side  267  is substantially co-planar with the circuit board  232 . A non-planar second side includes a first protruding portion  266 A and a second protruding portion  266 B that are substantially similar in shape, are provided opposite the first side  267 , and extend between the first end  261  and the second end  262 . A front longitudinal side  265  and a rear longitudinal side  264  extend between the first end  261  and the second end  262 . The front longitudinal side  265  and the rear longitudinal side  261  are substantially perpendicular to the first side  267 . The first protruding portion  266 A and the second protruding portion  266 B are substantially basin shaped. The distance between the outer surface of each protruding portion  266 A and  266 B and the first side  267  decreases when moving longitudinally (e.g., along longitudinal side  264  or  265 ) or latitudinally (e.g., along first end  261  or second end  262 ) from the longitudinal and latitudinal center point of each protruding portion  266 A and  266 B. 
         [0043]    The lens  260  extends between and beyond the inner concave surfaces  244  and  254 . In some embodiments the lens  260  may optionally comprise a first longitudinally extending lens having the first protruding portion  266 A and a second longitudinally extending lens having the second protruding portion  266 B. A Gaussian filter  269  may optionally extend between the first reflector  240  and the second reflector  250  and be interposed between the LEDs  234  and the lens  260 . The lens  260  has four attachment legs  272  extending from the lens generally in a direction away from the protruding portions  266 A and  266 B. The attachment legs  272  are provided on each corner of the lens  260  and have a chamfered locking protrusion  274  extending therefrom. Lens  260  may be coupled to first and second reflectors  240  and  250  by engaging the chamfered locking protrusions  274  against respective of flanges  246  and  256 , thereby causing the attachment legs  272  to be forced outward until the chamfered locking protrusions  274  lock with respective of flanges  246  and  256  as depicted in  FIG. 6 . The lens  260  may be removed from the first and second reflectors  240  and  250  by forcing the locking protrusions  274  outward by a hand, tool, or otherwise, and pulling the lens  260  away from the first and second reflectors  240  and  250 . The lens  260  may be interchanged with another lens having alternative optical characteristics (e.g., lens  160 ) and optionally having similar attachment legs. 
         [0044]    In operation, the LEDs  234  may be electrically coupled to a power source. Some light output from LEDs  234  will be directly incident on Gaussian filter  269  and then lens  260 . Some light output will first reflect off first reflector  240 , second reflector  250 , and/or an interior facing portion of one or more endplates and redirected toward filter  269  and then lens  260 . The first reflector  240 , second reflector  250 , and the lens  260  are configured for a square target medium distribution. The light output may be directed in substantially a batwing distribution pattern. A majority of the light emitted from the LEDs  234  will be directed out first protruding portion  266 A and second protruding portion  266 B and directed generally toward an area in a direction that first protruding portion  266 A and second protruding portion  266 B face. As will be understood by one of ordinary skill in the art, having had the benefit of the present disclosure, variations may be made to the first reflector  240 , second reflector  250 , and or lens  260  to achieve a desired light output that varies from the light output achieved by lighting unit  210 . 
         [0045]    Referring to  FIG. 7  through  FIG. 9 , a third embodiment of a lighting unit  310  is shown. The lighting unit  310  has a plurality of LEDs  334  mounted in a linear arrangement on a circuit board  332 . The circuit board  332  may optionally be coupled to a heatsink or other support surface. A longitudinally extending first reflector  340  is provided along a first side of the LEDs  334 . The first reflector  340  is a singular piece and extends longitudinally from a first end  341  to a second end  342  thereof along each of the LEDs  334 . In alternative embodiment the first reflector  340  may comprise multiple reflector pieces and/or may extend along less than all of the LEDs  334 . The first reflector  340  has an inner concave surface  344  that extends from adjacent the LEDs  334  in a direction outward and away from the LEDs  334  toward a flange  346  of the first reflector  340 . The flange  346  has a plurality of threaded apertures  349  extending therethrough. 
         [0046]    A longitudinally extending second reflector  350  is provided along a second side of the LEDs  334 . The second reflector  350  is a singular piece and extends longitudinally from a first end  351  thereof to a second end  352  thereof along each of the LEDs  334 . In alternative embodiments the second reflector  350  may comprise multiple reflector pieces and/or may extend along less than all of the LEDs  334 . The second reflector has an inner concave surface  354  that extends from adjacent the LEDs  334  in a direction outward and away from the LEDs  334  toward a flange  356  of the second reflector  350 . The flange  356  has a plurality of threaded apertures  359  extending therethrough. The inner concave surface  354  and the inner concave surface  344  share a substantially common degree of curvature and extend away from the LEDs  334  approximately the same distance and outward from the LEDs  334  approximately the same distance. The inner concave surface  354  and the inner concave surface  344  also share a substantially common degree of curvature wither inner concave surfaces  244  and  254  of the lighting unit  310 . 
         [0047]    First reflector  340  and/or second reflector  350  may, in some embodiments be coupled to circuit board  332 . For example, in some embodiments the first reflector  340  and/or the second reflector  350  may be coupled to the circuit board  332  using mechanical affixation methods. Although not depicted, an end plate may optionally be placed between first ends  341  and  351  of first and second reflectors  340  and  350  and/or second ends  342  and  352  of first and second reflectors  340  and  350 . The end plate may optionally be interiorly reflective or semi-reflective. 
         [0048]    A longitudinally extending lens  360  is provided over and spaced apart from the LEDs  334 . The lens  360  includes five individual lens pieces  360 A-E placed adjacent one another in a longitudinal relationship. The lens  360  is longitudinally extending from lens  360 A thereof to lens  360 E thereof. Each of the individual lens pieces  360 A-E share a common configuration and are placed over a single of the LEDs  334 . For ease and clarity in description, individual lens piece  360 A is the only of the individual lens pieces  360 A-E that is numbered in additional detail in the Figures and that will be described in additional detail herein. Individual lens piece  360 A is placed over a single of the LEDs  334 . A substantially planar first side  367 A of the individual lens piece  360 A extends between a first end  361 A and second end  362 A and faces the single of the LEDs  334 . The first side  367 A is substantially co-planar with the circuit board  332 . A non-planar second side  366 A has a substantially half-barrel shape, is provided opposite the first side  367 A and extends between the first end  361 A and the second end  362 A. A front longitudinal side  365 A and a rear longitudinal side  364 A extend between the first side  367 A and the second side  366 A. The front longitudinal side  365 A and the rear longitudinal side  364 A are substantially perpendicular to the first side  367 A. 
         [0049]    A pair of flanges  368 A extend peripherally of the rear longitudinal side  364 A and front longitudinal side  365 A and each have a fastener aperture  369 A provided therethrough. The individual lens piece  360 A may be coupled to first reflector  340  and second reflector  350  by placing threaded fasteners  309  through fastener apertures  369 A and threading the threaded fasteners  309  into respective of the threaded apertures  349  and  359 . The individual lens piece  360 A may be removed from first reflector  340  and second reflector  350  by unthreading the threaded fasteners  309  from respective of the threaded apertures  349  and  359 . The lens  360  may be interchanged with another lens having alternative optical characteristics and optionally having similar apertures for receiving threaded fasteners  309 . For example, the lens  360  may be interchanged with lens  160  or lens  260 , either of which may optionally incorporate apertures for receiving threaded fasteners  309 . One or more individual lens pieces  360 A-E may be interchanged with other lens pieces having alternative characteristics and optionally having similar apertures for receiving threaded fasteners  309 . In some embodiments a Gaussian filter may optionally be interposed between the LEDs  334  and at least some of the lens  360 . 
         [0050]    In operation, the LEDs  334  may be electrically coupled to a power source. Some light output from LEDs  334  will be directly incident on the lens  360 . Some light output will first reflect off first reflector  340 , second reflector  350 , and/or an interior facing portion of one or more end plates and redirected toward lens  360 . The first reflector  340 , second reflector  350 , and the lens  360  are configured for a spot target narrow distribution. A majority of the light emitted from the LEDs  334  will be directed out the second sides  366 A-E of the individual lens pieces  360 A-E and directed generally toward an area generally in a direction that the second sides  366 A-E face. As will be understood by one of ordinary skill in the art, having had the benefit of the present disclosure, variations may be made to the first reflector  340 , second reflector  350 , and or one or more of individual lens pieces  360 A-E to achieve a desired light output that varies from the light output achieved by lighting unit  310 . 
         [0051]    While several inventive embodiments have been described and illustrated herein, those of ordinary skill in the art will readily envision a variety of other means and/or structures for performing the function and/or obtaining the results and/or one or more of the advantages described herein, and each of such variations and/or modifications is deemed to be within the scope of the inventive embodiments described herein. More generally, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are meant to be exemplary and that the actual parameters, dimensions, materials, and/or configurations will depend upon the specific application or applications for which the inventive teachings is/are used. Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific inventive embodiments described herein. It is, therefore, to be understood that the foregoing embodiments are presented by way of example only and that, within the scope of the appended claims and equivalents thereto, inventive embodiments may be practiced otherwise than as specifically described and claimed. Inventive embodiments of the present disclosure are directed to each individual feature, system, article, material, kit, and/or method described herein. In addition, any combination of two or more such features, systems, articles, materials, kits, and/or methods, if such features, systems, articles, materials, kits, and/or methods are not mutually inconsistent, is included within the inventive scope of the present disclosure. 
         [0052]    All definitions, as defined and used herein, should be understood to control over dictionary definitions, definitions in documents incorporated by reference, and/or ordinary meanings of the defined terms. 
         [0053]    The indefinite articles “a” and “an,” as used herein in the specification and in the claims, unless clearly indicated to the contrary, should be understood to mean “at least one.” 
         [0054]    The phrase “and/or,” as used herein in the specification and in the claims, should be understood to mean “either or both” of the elements so conjoined, i.e., elements that are conjunctively present in some cases and disjunctively present in other cases. Multiple elements listed with “and/or” should be construed in the same fashion, i.e., “one or more” of the elements so conjoined. Other elements may optionally be present other than the elements specifically identified by the “and/or” clause, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, a reference to “A and/or B”, when used in conjunction with open-ended language such as “comprising” can refer, in one embodiment, to A only (optionally including elements other than B); in another embodiment, to B only (optionally including elements other than A); in yet another embodiment, to both A and B (optionally including other elements); etc. 
         [0055]    As used herein in the specification and in the claims, “or” should be understood to have the same meaning as “and/or” as defined above. For example, when separating items in a list, “or” or “and/or” shall be interpreted as being inclusive, i.e., the inclusion of at least one, but also including more than one, of a number or list of elements, and, optionally, additional unlisted items. Only terms clearly indicated to the contrary, such as “only one of” or “exactly one of,” or, when used in the claims, “consisting of,” will refer to the inclusion of exactly one element of a number or list of elements. In general, the term “or” as used herein shall only be interpreted as indicating exclusive alternatives (i.e. “one or the other but not both”) when preceded by terms of exclusivity, such as “either,” “one of,” “only one of,” or “exactly one of.” “Consisting essentially of,” when used in the claims, shall have its ordinary meaning as used in the field of patent law. 
         [0056]    As used herein in the specification and in the claims, the phrase “at least one,” in reference to a list of one or more elements, should be understood to mean at least one element selected from any one or more of the elements in the list of elements, but not necessarily including at least one of each and every element specifically listed within the list of elements and not excluding any combinations of elements in the list of elements. This definition also allows that elements may optionally be present other than the elements specifically identified within the list of elements to which the phrase “at least one” refers, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, “at least one of A and B” (or, equivalently, “at least one of A or B,” or, equivalently “at least one of A and/or B”) can refer, in one embodiment, to at least one, optionally including more than one, A, with no B present (and optionally including elements other than B); in another embodiment, to at least one, optionally including more than one, B, with no A present (and optionally including elements other than A); in yet another embodiment, to at least one, optionally including more than one, A, and at least one, optionally including more than one, B (and optionally including other elements); etc. 
         [0057]    In the claims, as well as in the specification above, all transitional phrases such as “comprising,” “including,” “carrying,” “having,” “containing,” “involving,” “holding,” “composed of,” and the like are to be understood to be open-ended, i.e., to mean including but not limited to. Only the transitional phrases “consisting of” and “consisting essentially of” shall be closed or semi-closed transitional phrases, respectively, as set forth in the United States Patent Office Manual of Patent Examining Procedures, Section 2111.03.