Patent Publication Number: US-10767836-B2

Title: Linear luminaire with optical control

Description:
TECHNICAL FIELD 
     The present disclosure relates generally to lighting fixtures, and more particularly to uniformity of light provided by lighting fixtures. 
     BACKGROUND 
     Some linear lighting fixtures, such as suspended light fixtures, emit light in directions above and/or below the lighting fixtures. In general, the down-light and up-light provided by such linear lighting fixtures may have non-uniformity lengthwise as well as widthwise. For example, such linear lighting fixtures may often have visual breaks in the emitted light because of sockets such as fluorescent bulb sockets of the lighting fixtures. Some linear lighting fixtures may also have seams between multiple lenses that are disposed along the lengths of the lighting fixtures. Approaches such as large distances between light sources and the lenses to reduce non-uniformity of the down-light may result in undesirably tall lighting fixtures. 
     Thus, a solution that provides uniformity of the light provided by linear lighting fixtures may be desirable. 
     SUMMARY 
     This present disclosure relates to uniformity of light provided by linear lighting fixtures. In some example embodiments, a linear luminaire includes a housing and a light emitting diode (LED) light source attached to the housing. The luminaire further includes an over-optic piece covering the LED light source, and a lens spaced from the over-optic piece and covering the over-optic piece from view. A distribution of light provided by the luminaire through the lens depends on the over-optic piece. 
     In another example embodiment, a linear luminaire includes a housing and a down-light light emitting diode (LED) light source attached to the housing. The down-light LED light source is positioned to emit a first light toward an area below the luminaire. The luminaire further includes an up-light LED light source and an over-optic piece covering the down-light LED light source. The up-light LED light source is positioned to emit a second light toward an area above the luminaire. The luminaire also includes a lens spaced from the over-optic piece and covering the over-optic piece from view. The over-optic piece changes a distribution of the first light passing through the over-optic piece. 
     These and other aspects, objects, features, and embodiments will be apparent from the following description and the claims. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       Reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein: 
         FIG. 1  illustrates a bottom isometric view of a linear luminaire according to an example embodiment; 
         FIG. 2  illustrates the linear luminaire of  FIG. 1  without the lens according to an example embodiment; 
         FIG. 3  illustrates the linear luminaire of  FIG. 1  without the lens and an over-optic piece according to an example embodiment; 
         FIG. 4  illustrates polar plots of intensity distributions of a light from an LED light source of the luminaire of  FIG. 1  with and without the over-optic according to an example embodiment; 
         FIG. 5  illustrates plots of direct luminance on the inside of the lens of the luminaire of  FIG. 1  with and without the over-optic according to an example embodiment; 
         FIG. 6  illustrates an end view of the linear luminaire of  FIG. 1  according to an example embodiment; 
         FIG. 7  illustrates a bottom isometric view of the linear luminaire of  FIG. 1  without the lens according to an example embodiment; 
         FIG. 8  illustrates a bottom isometric view of the linear luminaire of  FIG. 1  without the lens and over-optic pieces according to an example embodiment; 
         FIG. 9  illustrates an end view of the linear luminaire of  FIG. 1  with up-light and down-light sources according to an example embodiment; 
         FIG. 10  illustrates a bottom isometric view of the linear luminaire of  FIG. 1  with up-light and down-light sources and without the lens according to an example embodiment; 
         FIG. 11  illustrates a top isometric view of the linear luminaire of  FIG. 1  with up-light and down-light sources and without the lens according to an example embodiment; and 
         FIG. 12  illustrates a top isometric view of the linear luminaire of  FIG. 1  with up-light and down-light sources and without the lens and some over-optic pieces according to an example embodiment. 
     
    
    
     The drawings illustrate only example embodiments and are therefore not to be considered limiting in scope. The elements and features shown in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the example embodiments. Additionally, certain dimensions or placements may be exaggerated to help visually convey such principles. In the drawings, reference numerals designate like or corresponding, but not necessarily identical, elements. 
     DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS 
     In the following paragraphs, particular embodiments will be described in further detail by way of example with reference to the figures. In the description, well known components, methods, and/or processing techniques are omitted or briefly described. Furthermore, reference to various feature(s) of the embodiments is not to suggest that all embodiments must include the referenced feature(s). 
     In some example embodiments, a light source of a low-profile luminaire utilizing optical control can uniformly light a wide, seamless, continuous lens of the low-profile luminaire. A linear light engine, an over-optic, and a seamless lens allow for even illumination along the length and width of a linear luminaire. In some example embodiments, the luminaire may provide an up-light utilizing a light engine and an over-optic that can produce high angle light to uniformly illuminate a ceiling above the luminaire. 
     Turning now to the drawings,  FIG. 1  illustrates a bottom isometric view of a linear luminaire  100  according to an example embodiment. In some example embodiments, the linear luminaire  100  includes a housing  102 , a first end cap  104 , and second end cap  106 . The luminaire  100  also includes a lens  108 . The end cap  104  is attached to the housing  102  at a first end of the housing  102 , and the end cap  106  is attached to the housing  102  at a second opposite end of the housing  102 . The housing  102  may be made from aluminum or another suitable material using methods such as extrusion or other means as may be contemplated by those of ordinary skill in the art with the benefit of this disclosure. 
     In some example embodiments, the lens  108  extends along the length of the housing  102  between the end caps  104 ,  106 . For example, the lens  108  may be a single piece structure. To illustrate, the lens  108  may be a continuous lens that is seamless for the entire length of the lens  108 . The lens  108  may also be seamless for the entire width of the lens  108 . The lens  108  may be made from plastic, an acrylic or other suitable material. For example, the lens  108  may be a thin plastic that is unrolled for attachment to the housing  102 . 
       FIG. 2  illustrates the linear luminaire  100  of  FIG. 1  without the lens  108  according to an example embodiment. Referring to  FIGS. 1 and 2 , in some example embodiments, the linear luminaire  100  includes over-optic pieces  202 ,  204 ,  206 ,  208  that are covered from view by the lens  108  as illustrated in  FIG. 1 . The over-optic pieces  202 - 208  control distribution of light along the length and width of the luminaire  100 . For example, the over-optic pieces  202 ,  204 ,  206 ,  208  may cover the light source of the luminaire  100  and more evenly distribute the light provided by the light source of the luminaire  100  along the width of luminaire  100 , which allows the luminaire  100  to have a low-profile. The over-optic pieces  202 ,  204 ,  206 ,  208  may also distribute the light more evenly such that the light does not appear excessively brighter directly beneath the light source of the luminaire  100  as compared to at other locations as viewed through the lens  108  that covers the over-optic pieces  202 ,  204 ,  206 ,  208 . 
     In some example embodiments, the over-optic pieces  202 - 208  may be formed as a single over-optic piece that extends along the length of the housing  102 . For example, a linear single-piece optic that is seamless along the length of the housing  102  may be used instead of the individual over-optic pieces  202 ,  204 ,  206 ,  208 . The over-optic pieces  202 - 208 , as separate components or as a single component, may be made from plastic, acrylic, or another suitable material using methods such as extrusion, injection molding, etc. 
       FIG. 3  illustrates the linear luminaire  100  of  FIG. 1  without the lens  108  and an over-optic piece  202  according to an example embodiment. Referring to  FIGS. 1-3 , in some example embodiments, the linear luminaire  100  includes a light emitting diode (LED) light source  302  that includes LEDs  304  that are disposed on an LED circuit board  306 . In some example embodiments, the LED light source  302  may extend for the entire length of the housing  102 . For example, the LED circuit board  306  may include a single-piece circuit board or multiple circuit boards that together extend the length of the housing  102 , avoiding shadows as viewed through the lens  108 . The LEDs  304  may be distributed evenly along the length of the LED light source  302 . In some example embodiments, the LEDs  304  may have a different configuration than shown without departing from the scope of this disclosure. 
     The linear LED light source  302  and the over-optic pieces  202 - 208  allow the luminaire  100  to have a low-profile (i.e., a shorter height) and to evenly illuminate a wider lens, which results in a wide distribution of light along the entire length of the housing  102 . For example, the luminaire  100  can have a height of approximately 2.5 inches. 
       FIG. 4  illustrates polar plots of intensity distributions of a light from the LED light source  302  of the luminaire  100  of  FIG. 1  according to an example embodiment. Referring to  FIGS. 1-4 , the plot  402  illustrates an example distribution of the light from the LED light source  302  without the over-optic pieces  202 - 208 . The plot  404  illustrates an example distribution of the light from the LED light source  302  with the over-optic pieces  202 - 208 . As illustrated by the plots  402 ,  404 , the over-optic pieces  202 - 208  result in a wider distribution of the light from the light source  302 , which allows the lens  108  to have a wide dimension and the luminaire  100  to have a low-profile. 
       FIG. 5  illustrates plots of direct luminance on the inside of the lens  108  of the luminaire  100  of  FIG. 1  with and without the over-optic according to an example embodiment. Referring to  FIGS. 1-3 and 5 , the plot  502  illustrates an example direct luminance of the light from the LED light source  302  on the inside of the lens  108  without the over-optic pieces  202 - 208 . The plot  504  illustrates an example direct luminance of the light from the LED light source  302  on the inside of the lens  108  with the over-optic pieces  202 - 208 . As illustrated by the plots  502 ,  504 , the over-optic pieces  202 - 208  result in a wider distribution of the light from the light source  302 , which allows the lens  108  to have a wide dimension and the luminaire  100  to have a low-profile. 
       FIG. 6  illustrates an end view of the linear luminaire  100  of  FIG. 1  with the end caps  104 ,  106  according to an example embodiment, and  FIG. 7  illustrates a bottom isometric view of the linear luminaire  100  of  FIG. 1  without the lens  108  according to an example embodiment. Referring to  FIGS. 1-7 , in some example embodiments, the LED light source  302  that includes the LED board  306  may be attached to a back section  602  of the housing  102 . For example, the LED board  306  may be attached to the back section  602  of the housing  102  by an adhesive and/or one or more fasteners. 
     In some example embodiments, the lens  108  may be positioned on a ledge  628  on a first longitudinal side of the luminaire  100  and on a ledge  630  on a second opposite longitudinal side of the luminaire  100 . For example, the lens  108  may be slid or pulled along the ledges  628 ,  630  that may be extend for an entire or parts of the housing  102 . In some example embodiments, the lens  108  may be slightly arched, for example, upward after attachment to the housing  102 . In some alternative embodiments, the lens  108  may be attached to the housing  102  by other means as may be contemplated by those of ordinary skill in the art with the benefit of this disclosure. 
     In some example embodiments, the over-optics  202 - 208  may each include snaps  614 ,  616  that snap over a respective ledge of the housing  102  to securely attach the over-optics  202 - 208  to the housing  102 . In some alternative embodiments, the over-optics  202 - 208  may be attached to the housing  102  using other means as may be contemplated by those of ordinary skill in the art with the benefit of this disclosure. 
     In some example embodiments, the luminaire  100  may include a driver  606  that provides power to the LED light source  302  including the LEDs  304 . For example, the driver  606  may be coupled to one or more connectors  604  of the LED board  306  by one or more electrical wires (not shown). The luminaire  100  may also include another driver  608  that provides power to the LED light source  302 . For example, the driver  606  may provide power to some of the LEDs  304 , and the driver  608  may provide power to remaining ones of the LEDs  304 . Alternatively, the outputs of the drivers  606 ,  608  may be combined to provide power to the LED light source  302 . In some example embodiments, one or more of drivers  606 ,  608  may have wireless communication capability, for example, to control the power provided to the LED light source  302 . In some alternative embodiments, the luminaire  100  may include more or fewer drivers than shown. 
     In some example embodiments, the drivers  606 ,  608  may be positioned in cavities of the housing  102 . For example, the driver  606  may be attached to the housing  102  by a fastener  610  in one cavity, and the driver  608  may be attached to the housing  102  by a fastener  612  in another cavity. Alternatively, the drivers  606 ,  608  may be positioned in the same cavity of the housing  102 . 
     In some example embodiments, luminaire  100  may include cover structures  618 ,  620  that cover the cavities of the housing  102 . The luminaire  100  may also include a center cover piece  622  that may extend behind as well as on longitudinal sides of the LED light source  302 . The center cover piece  622  may be attached to the housing  102  by one or more fasteners such as fasteners  624 ,  626  or by other means as may be contemplated by those of ordinary skill in the art with the benefit of this disclosure. The center cover piece  622  may provide a defined conduit for routing electrical wires along the length of the housing  102 . For example, the center cover piece  622  may include openings or slots that allow the routing of wires to/from the one or more drivers  606 ,  608 . The cover structures  618 ,  620  and the center cover piece  622  may be made from sheet metal, plastic, or another material. 
     In some example embodiments, the luminaire  100  may be suspended from a ceiling or another structure using a suspension structure  632  that has cables that extend out and attach to the housing  102 . In some example embodiments, another suspension structure may be used at the opposite end of the housing  102  to similarly suspend the luminaire  100  from a ceiling or another structure. 
     In some alternative embodiments, the housing  102  may have a different shape than shown without departing from the scope of this disclosure. In some alternative embodiments, the luminaire  100  may be suspended by means other than shown without departing from the scope of this disclosure. In some alternative embodiments, one or more of the over-optic pieces  202 - 208  may have a different shape than shown without departing from the scope of this disclosure. 
       FIG. 8  illustrates a bottom isometric view of the linear luminaire  100  of  FIG. 1  without the lens and over-optic pieces  204 ,  206  according to an example embodiment. Referring to  FIGS. 1-8 , in some example embodiments, the LED circuit board  306  of the light source  302  may include multiple LED circuit boards such as LED circuit boards  802 ,  804 . For example, each LED circuit board  802 ,  804  may include respective LEDs  806 ,  808 , where the LEDs at adjacent edges of the LED circuit boards  802 ,  804  are spaced by substantially the same distance from each other as the other LEDs on the respective LED circuit board  802 ,  804 . In some alternative embodiments, the LED circuit board  306  may be a single circuit board that extends the entire length of the housing  102 . 
     The linear LED light source  302  and the over-optic pieces  202 - 208  allow the luminaire  100  to have a relatively wide dimension and a low-profile, where the lens  108  is relatively wide and close to the LED light source  302 . By providing more evenly distributed lighting, the number of luminaires that are needed to adequately illuminate an area may be reduced. 
     In some example embodiments, the luminaire  100  may have a length (i.e., generally between the end caps  104 ,  110 ) in the range of 4 ft. to 12 ft. For example, the luminaire  100  may have a length of approximately 4 ft. As another example, the luminaire  100  may have a length of approximately 8 ft. As another example, the luminaire  100  may have a length of approximately 12 ft. In some alternative embodiments, the luminaire  100  may have a length that is less than 4 ft. or more than 12 ft. 
     In some example embodiments, the number of over-optic pieces may depend on the length of the luminaire  100 . The number of individual circuit boards that the LED circuit board  306  includes may also depend on the length of the luminaire  100 . For example, the LED circuit board  306  may include a single circuit board when the luminaire  100  is 4 ft. long and may include two linearly adjacent circuit boards when the luminaire  100  is 8 ft. long. The lens  108  may be a linearly single-piece lens regardless of the length of the luminaire  100 . 
       FIG. 9  illustrates an end view of the linear luminaire  100  of  FIG. 1  with up-light and down-light sources according to an example embodiment, and  FIG. 10  illustrates a bottom isometric view of the linear luminaire  100  of  FIG. 1  with up-light and down-light sources and without the lens  108  according to an example embodiment. Referring to  FIGS. 1-10 , in some example embodiments, the luminaire  100  includes the lens  108 , the over-optic pieces  202 - 208 , and the LED light source  302  that provides the down-light from the luminaire  100 . The LED light source  302  includes the LEDs  304  that are disposed on the LED board  306  as described above. 
     In some example embodiments, the luminaire  100  may also include an LED light source  904  that is covered by one or more over-optic pieces including an over-optic piece  902  and that provides an up-light of the luminaire  100 . The LED light source  904  may include LEDs  906  that are disposed on one or more LED circuit boards  908 . For example, the LED light source  904  may emit an up-light toward a ceiling when the luminaire  100  is suspended from the ceiling by one or more suspension structures such as the suspension structure  632 . The LEDs  906  may be distributed evenly along the LED circuit board  908 . 
     In some example embodiments, the over-optic piece  902  and other over-optic pieces covering the LEDs  906  of the light source  904  may be attached to the center cover piece  622 . For example, the LED light source  904  may be positioned on the center cover piece  622 . The over-optic piece  902  and other over-optic pieces may include snaps  912 ,  914  that are inserted in respective slots formed in the center cover piece  622 . Alternatively, the over-optic piece  902  and the other over-optic pieces may be attached by other means without departing from the scope of this disclosure. 
     In some example embodiments, the luminaire  100  includes one or more of the drivers  606 ,  608  that are disposed in one or more cavities of the housing  102 . For example, the driver  606  may provide power to the LED light source  302 , and the driver  608  may provide power to the LED light source  904 . Alternatively, the drivers  606 ,  608  may together provide power to the LED light sources  302 ,  904 . In some alternative embodiments, the luminaire  100  may include fewer or more drivers than shown. 
     In some example embodiments, the luminaire  100  may include a support structure  910  that supports to the LED light source  904  as well as the over-optic pieces including the over-optic piece  902 . For example, the support structure  910  may be positioned between the housing  102  and the center cover piece  622 . Electrical wires may be routed through the support structure  910  between the drivers  606 ,  608  and the LED light sources  302 ,  904 . The support structure  910  may be made from sheet metal, plastic, or another suitable material. In some alternative embodiments, the center cover piece  622  may be omitted without departing from the scope of this disclosure. 
       FIG. 11  illustrates a top isometric view of the linear luminaire  100  of  FIG. 1  with up-light and down-light sources and without the lens  108  according to an example embodiment. Referring to  FIGS. 1-11 , in some example embodiments, the luminaire  100  includes the over-optic pieces  902 ,  1102 ,  1104 ,  1106 . The over-optic pieces  902 ,  1102 ,  1104 ,  1106  control distribution of the up-light provided by the LED light source  904  along the length and width of the luminaire  100 . For example, the over-optic pieces  902 ,  1102 ,  1104 ,  1106  may cover the LEDs  906  of the LED light source  904  and more evenly distribute the light provided by the LED light source  904  of the luminaire  100  along the width of luminaire  100  for the length of the housing  102 . The over-optic pieces  902 ,  1102 ,  1104 ,  1106  may distribute the light more evenly such that the light does not appear excessively bright directly above the light source  904  as compared to at other locations above the light source  904 . 
     In some example embodiments, the luminaire  100  may include a single-piece over-optic instead of multiple over-optic pieces  902 ,  1102 ,  1104 ,  1106 . In some alternative embodiments, the luminaire  100  may include more or fewer over-optic pieces than shown without departing from the scope of this disclosure. In some example embodiments, the over-optic pieces  902 ,  1102 ,  1104 ,  1106  may have the same shape and may be made in the same or similar manner as the over-optic pieces  202 - 208 . Alternatively, the over-optic pieces  902 ,  1102 ,  1104 ,  1106  may have a different shape than the over-optic pieces  202 - 208 . 
     In some example embodiments, the luminaire  100  provides both up-light and down-light that have wider and more even distributions than otherwise provided by a linear luminaire that does not have the over-optic pieces. For example, the luminaire  100  can uniformly light a ceiling without bright spots and may allow larger distances between luminaires. 
       FIG. 12  illustrates a top isometric view of the linear luminaire  100  of  FIG. 1  with up-light and down-light sources and without over-optic pieces  902 ,  1102  according to an example embodiment. Referring to  FIGS. 1-12 , the LED circuit board  908  may be a single circuit board that extends along the length of the housing  102  or may include multiple circuit boards. In embodiments where the LED circuit board  908  includes multiple circuit boards, each LED circuit board may include respective LEDs  906  such that the LEDs at adjacent edges of the multiple LED circuit boards are spaced by substantially the same distance from each other as the other LEDs on the respective LED circuit board. 
     In some example embodiments, the number of over-optic pieces covering the LEDs  906  of the LED light source  904  and the number of LED circuits of the LED light source  904  depend on the length of the luminaire  100  in a similar manner as described above. In some example embodiments, the LEDs  906  may have a different configuration than shown without departing from the scope of this disclosure. 
     Although particular embodiments have been described herein in detail, the descriptions are by way of example. The features of the embodiments described herein are representative and, in alternative embodiments, certain features, elements, and/or steps may be added or omitted. Additionally, modifications to aspects of the embodiments described herein may be made by those skilled in the art without departing from the spirit and scope of the following claims, the scope of which are to be accorded the broadest interpretation so as to encompass modifications and equivalent structures.