Abstract:
A light fixture includes multiple light emitting diode (“LED”) modules. Each LED module includes a substrate on which one or more LED&#39;s are disposed. The LED modules can interface with one another in a variety of different configurations including an end-to-end configuration in which adjacent ends of the LED modules interface with one another. When adjacent LED modules interface with one another, there is a substantially continuous array of LED&#39;s across the LED modules. For example, one or more rows or alignment patterns of the LED&#39;s may continue, substantially uninterrupted, within and across the LED modules. Electrical connectors or other means for powering the LED modules are disposed remote from the interfacing locations. For example, electrical connectors may couple to side ends of the LED modules, away from interfacing ends of the LED modules. Thus, the electrical connectors do not impact the continuity of light across adjacent LED modules.

Description:
TECHNICAL FIELD 
       [0001]    The invention relates generally to light emitting diodes (“LED&#39;s”) and more particularly to LED modules that interface with one another in a variety of different configurations to provide a substantially continuous array of LED&#39;s across the LED modules. 
       BACKGROUND 
       [0002]    The use of LED&#39;s in place of conventional incandescent, fluorescent, and neon lamps has a number of advantages. LED&#39;s tend to be less expensive and longer lasting than conventional incandescent, fluorescent, and neon lamps. In addition, LED&#39;s generally can output more light per watt of electricity than incandescent, fluorescent, and neon lamps. 
         [0003]    Linear light fixtures are popular for a variety of different residential and commercial lighting applications, including cabinet lighting, shelf lighting, cove lighting, and signage. Cove lighting is a form of indirect lighting in which lamps are built into ledges, recesses, or valences in a ceiling or high on the walls of a room. Linear light fixtures can provide primary lighting in an environment or serve as aesthetic accents or designs that complement other lighting sources. 
         [0004]    Conventional linear LED light fixtures include modules or strips of LED&#39;s that are mechanically and electrically coupled to one another in an end-to-end relationship.  FIG. 1  illustrates two conventional LED strips  105  and  106  that could be used in such a light fixture. Each strip  105 ,  106  includes multiple LED&#39;s  108 . A second end  105   b  of strip  105  is electrically and mechanically coupled to a first end  106   a  of strip  106  via a connector  110 . Adjacent pairs of LED&#39;s  108   a - 108   d  on strip  105  are spaced apart from one another by a distance X. Adjacent pairs of LED&#39;s  108   e - 108   h  on strip  106  are spaced apart from one another by the same distance X. 
         [0005]    Adjacent LED&#39;s  108   d  and  108   e  across the LED strips  105  and  106  are spaced apart from one another by a distance Y. The distance Y is significantly larger than the distance X. This space between the LED&#39;s  108   d  and  108   e  causes the light output by the LED strips  105  and  106  to be discontinuous. In particular, the light output by the LED strips  105  and  106  includes an undesirable break or shadow that corresponds to the space between the LED strips  105  and  106 . 
         [0006]    Therefore, a need exists in the art for an improved linear LED light fixture. In particular, a need exists in the art for LED modules that interface with one another in a way that produces continuous light output across the LED modules. A further need exists in the art for such light output to be devoid of undesirable shadows and breaks. 
       SUMMARY 
       [0007]    The invention provides an improved linear LED light fixture. In particular, the invention provides LED modules that interface with one another in a variety of different configurations to provide a substantially continuous array of LED&#39;s across the LED modules. This continuity in the array of the LED&#39;s enables the LED modules to output continuous light across the LED modules, without any undesirable shadows or breaks. 
         [0008]    Each LED module includes a substrate on which one or more LED&#39;s are disposed. The LED modules can interface with one another in a substantially continuous, end-to-end relationship. For example, each substrate can include a notch or protrusion in which a corresponding protrusion or notch of an adjacent substrate may be disposed. When adjacent LED modules interface with one another, there is a substantially continuous array of LED&#39;s across the LED modules. For example, one or more rows or patterns of LED&#39;s may continue, substantially uninterrupted, within and across the LED modules. 
         [0009]    The LED modules may be powered using electrical connectors, which electrically couple together adjacent LED modules. Each electrical connector can be coupled to its associated LED modules at locations other than the ends at which the LED modules interface with one another. Thus, unlike with the conventional LED strips  105  and  106  depicted in  FIG. 1 , the electrical connectors do not impact the continuity of light across adjacent LED modules. In addition to, or instead of, electrical connectors, powered surfaces, such as rails and tracks, may power the LED modules. For example, the LED modules may be coupled to the powered surfaces. 
         [0010]    A light fixture may include multiple LED modules mounted to a surface. For example, the LED modules may be removably coupled to the surface using screws, nails, or other fastening devices. The light fixture may be a linear or non-linear light fixture used in residential, commercial, or other lighting applications. 
         [0011]    These and other aspects, features and embodiments of the invention will become apparent to a person of ordinary skill in the art upon consideration of the following detailed description of illustrated embodiments exemplifying the best mode for carrying out the invention as presently perceived. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]    For a more complete understanding of the present invention and the advantages thereof, reference is now made to the following description, in conjunction with the accompanying figures briefly described as follows. 
           [0013]      FIG. 1  is a block diagram that illustrates conventional LED strips of a linear light fixture. 
           [0014]      FIG. 2  is a top elevational view of an LED assembly, which includes linear LED modules, in accordance with certain exemplary embodiments. 
           [0015]      FIG. 3  is a side elevational view of one of the linear LED modules depicted in  FIG. 2 , in accordance with certain exemplary embodiments. 
           [0016]      FIG. 4  is a top elevational view of an LED assembly, which includes multiple groupings of the linear LED modules depicted in  FIG. 2 , in accordance with certain exemplary embodiments. 
           [0017]      FIG. 5  is a top elevational view of an LED assembly, which includes LED modules arranged in an “L” shape, in accordance with certain exemplary embodiments. 
           [0018]      FIG. 6  is a top elevational view of an LED assembly of linear LED modules, in accordance with certain alternative exemplary embodiments. 
           [0019]      FIG. 7  is an elevational bottom view of a light fixture that includes the linear LED modules depicted in  FIG. 2 , in accordance with certain exemplary embodiments. 
       
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
       [0020]    The invention is directed to LED modules that interface with one another in a variety of different configurations to provide a substantially continuous array of LED&#39;s across the LED modules. This continuity in the array of the LED&#39;s enables the LED modules to output continuous light across the LED modules, without any undesirable shadows or breaks. The LED modules can provide light in any of a number of different residential and commercial lighting applications. For example, the LED modules can be installed on any surface to provide cabinet lighting, shelf lighting, cove lighting, and signage. 
         [0021]    Turning now to the drawings, in which like numerals indicate like elements throughout the figures, exemplary embodiments of the invention are described in detail.  FIG. 2  is a top elevational view of an LED assembly  290 , which includes LED modules  200 , in accordance with certain exemplary embodiments.  FIG. 3  is a side elevational view of one of the LED modules  200 , in accordance with certain exemplary embodiments. With reference to  FIGS. 2 and 3 , each LED module  200  is configured to create artificial light or illumination via multiple LED&#39;s  205 . For purposes of this application, each LED  205  may be a single LED die or may be an LED package having one or more LED dies on the package. In certain exemplary embodiments, the number of dies on each LED package ranges from 1-312. For example, each LED package may include 2 dies. 
         [0022]    Each LED module  200  includes at least one substrate  207  to which the LED&#39;s  205  are coupled. Each substrate  207  includes one or more sheets of ceramic, metal, laminate, circuit board, flame retardant (FR) board, mylar, or other material. Although depicted in  FIGS. 2 and 3  as having a substantially rectangular shape, a person of ordinary skill in the art having the benefit of the present disclosure will recognize that the substrate  207  can have any linear or non-linear shape. Each LED  205  is attached to its respective substrate  207  by a solder joint, a plug, an epoxy or bonding line, or other suitable provision for mounting an electrical/optical device on a surface. Each LED  205  includes semi-conductive material that is treated to create a positive-negative (p-n) junction. When the LED&#39;s  205  are electrically coupled to a power source  220 , such as a driver, current flows from the positive side to the negative side of each junction, causing charge carriers to release energy in the form of incoherent light. 
         [0023]    The wavelength or color of the emitted light depends on the materials used to make each LED  205 . For example, a blue or ultraviolet LED typically includes gallium nitride (GaN) or indium gallium nitride (InGaN), a red LED typically includes aluminum gallium arsenide (AlGaAs), and a green LED typically includes aluminum gallium phosphide (AlGaP). Each of the LED&#39;s  205  is capable of being configured to produce the same or a distinct color of light. In certain exemplary embodiments, the LED&#39;s  205  include one or more white LED&#39;s and one or more non-white LED&#39;s, such as red, yellow, amber, green, or blue LED&#39;s, for adjusting the color temperature output of the light emitted from the LED modules  200 . A yellow or multi-chromatic phosphor may coat or otherwise be used in a blue or ultraviolet LED  205  to create blue and red-shifted light that essentially matches blackbody radiation. The emitted light approximates or emulates “white,” light to a human observer. In certain exemplary embodiments, the emitted light includes substantially white light that seems slightly blue, green, red, yellow, orange, or some other color or tint. In certain exemplary embodiments, the light emitted from the LED&#39;s  205  has a color temperature between 2500 and 6000 degrees Kelvin. 
         [0024]    In certain exemplary embodiments, an optically transmissive or clear material (not shown) encapsulates at least some of the LED&#39;s  205 , either individually or collectively. This encapsulating material provides environmental protection while transmitting light from the LED&#39;s  205 . For example, the encapsulating material can include a conformal coating, a silicone gel, a cured/curable polymer, an adhesive, or some other material known to a person of ordinary skill in the art having the benefit of the present disclosure. In certain exemplary embodiments, phosphors are coated onto or dispersed in the encapsulating material for creating white light. 
         [0025]    Each LED module  200  includes one or more rows of LED&#39;s  205 . The term “row” is used herein to refer to an arrangement or a configuration whereby one or more LED&#39;s  205  are disposed approximately in or along a line. LED&#39;s  205  in a row are not necessarily in perfect alignment with one another. For example, one or more LED&#39;s  205  in a row might be slightly out of perfect alignment due to manufacturing tolerances or assembly deviations. In addition, LED&#39;s  205  in a row might be purposely staggered in a non-linear or non-continuous arrangement. Each row extends along a longitudinal axis of the LED module  200 . 
         [0026]    Although depicted in  FIG. 2  as having two staggered rows of LED&#39;s  205 , a person of ordinary skill in the art having the benefit of the present disclosure will recognize that the LED&#39;s  205  can be arranged in any number of different rows, shapes, and configurations without departing from the spirit and scope of the invention. For example, the LED&#39;s  205  can be arranged in four different rows, with each row comprising LED&#39;s  205  of a different color. In certain exemplary embodiments, each row and/or each LED  205  is separately controlled by the driver so that each row can independently be turned on and off or otherwise reconfigured. 
         [0027]    In the exemplary embodiment depicted in  FIG. 2 , each LED module  200  includes 16 LED&#39;s  205 . The number of LED&#39;s  205  on each LED module  200  may vary depending on the size of the LED module  200 , the size of the LED&#39;s  205 , the amount of illumination required from the LED module  200 , and/or other factors. For example, a larger LED module  200  with small LED&#39;s  205  may include more LED&#39;s  205  than a smaller LED module  200  with large LED&#39;s  205 . 
         [0028]    Adjacent pairs of LED&#39;s  205  on each LED module  200  are spaced apart from one another by a distance Z. Adjacent LED&#39;s  205   p  and  205   q  across LED modules  200 A and  200 B are spaced apart from one another by the same or substantially the same distance Z. Similarly, adjacent LED&#39;s  205   r  and  205   s  across LED modules  200 B and  200 C are spaced apart from one another by the same or substantially the same distance Z. Thus, all adjacent pairs of LED&#39;s  205  across the LED modules  200  are spaced apart by the same or substantially the same distance Z. This equal or substantially equal spacing across the LED modules  200  provides a continuous array of LED&#39;s  205  across the LED modules  200 . Because the array is continuous, light output from the LED modules  200  is continuous, without any undesirable breaks or shadows. As described below with reference to  FIG. 5 , in certain alternative exemplary embodiments, the LED modules  200  can be configured to provide a substantially continuous array of LED&#39;s  205  without each adjacent pair of LED&#39;s  205  being equally spaced apart. 
         [0029]    Ends  210  and  211  of each LED module  200  have profiles that enable adjacent pairs of the LED modules  200  to interface with one another. For example, in the embodiment depicted in  FIG. 2 , a first side end  210  of each LED module  200  includes a protrusion  210   a  that is sized and configured to be at least partially disposed adjacent a corresponding notch  211   a  in a second side end  211  of an adjacent LED module  200 . Similarly, the second side end  211  of each LED module  200  includes a protrusion  211   b  that is sized and configured to be at least partially disposed adjacent a corresponding notch  210   b  in the first side end  210  of an adjacent LED module  200 . Although depicted in  FIG. 2  as substantially rectangular, the notches  210   b  and  211   a  and protrusions  210   a  and  211   b  in the LED modules  200  can have any size or shape. In addition, although depicted in  FIG. 2  in an end-to-end relationship, adjacent LED modules  200  may interface one another in other configurations. For example, LED modules  200 B and  200 C may be arranged such that the protrusion  210   a  of LED module  200 C rests at least partially adjacent the notch  211   a  or protrusion  211   b  of LED module B and a longitudinal axis of LED module  200 C is disposed substantially perpendicular to a longitudinal axis of LED module  200 B, substantially as described below with reference to  FIG. 5 . 
         [0030]    A person of ordinary skill in the art having the benefit of the present disclosure will recognize that any of a number of other configurations of the adjacent ends  210  and  211  may be used to interface adjacent LED modules  200 . For example, in certain alternative exemplary embodiments, the end of one LED module  200  can include multiple protrusions that are sized and configured to be disposed within corresponding notches in an adjacent LED module  200 . Alternatively, in certain exemplary embodiments, one or both of the ends of each LED module  200  may have a substantially flat edge with not notches or protrusions. In certain alternative exemplary embodiments, only one of the ends  210  and  211  of each LED module  200  may have a profile that enables the LED module  200  to interface with another LED module  200 . In certain exemplary embodiments, a top side end  212  of each LED module  200  includes one or more protrusions  212   a  and notches  212   b  sized and configured to engage one or more of the notches  210   b  and  211   a  and protrusions  210   a  and  211   b  in the side ends  210  and  211  of another, adjacent LED module  200 . 
         [0031]    In certain exemplary embodiments adjacent LED modules  200  are electrically coupled to one another via a connector  225 . Each connector  225  can include one or more electrical wires, plugs, sockets, and/or other components that enable electrical transmission between electrical devices. In these exemplary embodiments, each connector  225  includes a first end  226  that is coupled to a protrusion  212   a  in a top side end  212  of one LED module  200  and a second end  227  that is coupled to a protrusion  212   a  in a top side end  212  of an adjacent LED module  200 . 
         [0032]    Because the connectors  225  extend from top side ends  212  of the LED modules  200 , and not from interfacing side ends  210  and  211  of the LED modules  200 , the LED modules  200  can engage one another without any significant gaps between the LED modules  200  or the pattern of LED&#39;s  205  on the LED modules  200 . Thus, the LED modules  200  can provide a substantially continuous array or pattern of LED&#39;s  205  across the LED modules  200 . A person of ordinary skill in the art having the benefit of the present disclosure will recognize that, in alternative exemplary embodiments, each connector  225  may be coupled to its corresponding LED modules  200  at other locations. For example, one or more of the connectors  225  can be connected to a bottom end  213  of an LED module  200 . In certain alternative exemplary embodiments, the LED modules  200  can be mounted to a powered rail, track, or other device, which powers the LED modules  200  without using any connectors  225 . 
         [0033]    Each LED module  200  is configured to be mounted to a surface (not shown) to illuminate an environment associated with the surface. For example, each LED module  200  may be mounted to, or within, a wall, counter, cabinet, sign, light fixture, or other surface. Each LED module  200  may be mounted to its respective surface using solder, braze, welds, glue, epoxy, rivets, clamps, screws, nails, or other fastening means known to a person of ordinary skill in the art having the benefit of the present disclosure. In certain exemplary embodiments, one or more of the LED modules  200  are removably mounted to their corresponding surfaces to enable efficient repair, replacement, and/or reconfiguration of the LED module(s)  200 . For example, each LED module  200  may be removably mounted to its corresponding surface via one or more screws extending through openings  215   a  defined in protrusions  215  in the top side end  212  of the LED module  200 . 
         [0034]    To remove one of the LED modules  200 , a person can simply disconnect the connector(s)  225  associated with the LED module  200  and unscrew the screws associated with the LED module  200 . In certain exemplary embodiments, once the LED module  200  is removed, the remaining LED modules  200  may be electrically coupled to one another using one or more of the disconnected connectors  215 . For example, if a person removes LED module  200 B, he can electrically couple LED module  200 A to LED module  200 C by connecting the connector  225   a  to the LED module  200 C in place of the connector  225   b.    
         [0035]    The level of light a typical LED  205  outputs depends, in part, upon the amount of electrical current supplied to the LED  205  and upon the operating temperature of the LED  205 . Thus, the intensity of light emitted by an LED  205  changes when electrical current is constant and the LED&#39;s  205  temperature varies or when electrical current varies and temperature remains constant, with all other things being equal. Operating temperature also impacts the usable lifetime of most LED&#39;s  205 . 
         [0036]    As a byproduct of converting electricity into light, LED&#39;s  205  generate a substantial amount of heat that raises the operating temperature of the LED&#39;s  205  if allowed to accumulate on the LED&#39;s  205 , resulting in efficiency degradation and premature failure. Each LED module  200  is configured to manage heat output by its LED&#39;s  205 . Specifically, each LED module  200  includes a conductive member  305  that is coupled to the substrate  207  and assists in dissipating heat generated by the LED&#39;s  205 . Specifically, the member  305  acts as a heat sink for the LED&#39;s  205 . The member  305  receives heat conducted from the LED&#39;s  205  through the substrate  207  and transfers the conducted heat to the surrounding environment (typically air) via convection. 
         [0037]      FIG. 4  is a top elevational view of an LED assembly  400 , which includes multiple groupings of the LED modules  200  depicted in  FIG. 2 , in accordance with certain exemplary embodiments. In addition to the interfaces at the side ends  210  and  211  of the LED modules, interfaces exist at bottom ends  213  of the LED modules  200 . Specifically, a bottom end  213  of each LED module  200  engages a bottom end  213  of another, adjacent LED module  200 . By interfacing the bottom ends  213 , two adjacent LED modules  200  having a particular width can effectively constitute a single, continuous LED source that has a width that is twice the width of a single LED module. 
         [0038]    The options for configuring and arranging multiple LED modules  200  with respect to one another are infinite. For example, multiple LED modules  200  can be arranged to form any of a variety of numbers, letters, shapes, etc. For example,  FIG. 5  is a top elevational view of an LED assembly  500 , which includes LED modules  200  arranged in an “L” shape, in accordance with certain exemplary embodiments. Thus, the LED modules  200  provide a flexible and efficient lighting option for both new lighting application installations and retro-fit applications. For example, in certain exemplary embodiments, LED modules  200  may be arranged on, and secured to, a member to be retro-fit into an existing light fixture. 
         [0039]      FIG. 6  is a top elevational view of an LED assembly  600 , which includes linear LED modules  610 A and  610 B, in accordance with certain alternative exemplary embodiments. Like the LED modules  200 A- 200 C depicted in  FIG. 2 , each of the LED modules  610  includes one or more rows of LED&#39;s  205 . Unlike the LED&#39;s  205  in the LED modules  200 A- 200 C, the LED&#39;s  205  in the LED modules  610 A and  610 B are not equally spaced apart. Instead, the LED&#39;s  205  in the LED modules  610 A and  610 B are arranged in a pattern in which adjacent pairs of LED&#39;s  205  have different spacings. In certain exemplary embodiments, the pattern is predictable and repeated on the same LED module  610 . In addition, or in the alternative, because the LED modules  610  interface one another without any gaps between the LED modules  610 , the pattern may be repeated continuously across adjacent modules  610 A and  610 B. 
         [0040]      FIG. 7  is an elevational bottom view of a light fixture  700  that includes the linear LED modules  200  depicted in  FIG. 2 , in accordance with certain exemplary embodiments. The light fixture  700  includes a troffer  705  that includes a frame  710  having side ends  715   a  and  715   b  and a top  720  extending between the side ends  715   a  and  715   b . In certain exemplary embodiments, each side end  715   a  and  715   b  extends from the top  720  at a substantially orthogonal angle. The side ends  715   a  and  715   b  and top  720  define an interior region  725 . 
         [0041]    Rows  730   a  and  730   b  of LED modules  200  extend within the interior region  725 , substantially between the side ends  715   a  and  715   b . Each LED module  200  is mounted to the top  720  via solder, braze, welds, glue, epoxy, rivets, clamps, screws, nails, or other fastening means known to a person of ordinary skill in the art having the benefit of the present disclosure. In certain exemplary embodiments, one or more of the LED modules  200  are removably mounted to the top  720  to enable efficient repair, replacement, and/or reconfiguration of the LED module(s)  200 . For example, each LED module  200  may be removably mounted to the top  720  via one or more screws  735  extending through protrusions  215  of each LED module  200 , substantially as described above. The LED modules  200  are electrically coupled to one another and to a power source (not shown) via one or more wires  740 , substantially as described above. 
         [0042]    The LED fixture  700  outputs light from the LED modules  200  into an environment associated with the LED fixture  700 . Although  FIG. 7  depicts a troffer LED fixture  700 , a person of ordinary skill in the art having the benefit of the present disclosure will recognize that the LED modules  200  may be used in any other light fixture. For example, the LED modules  200  may be used in light fixtures for indoor and/or outdoor, commercial and/or residential applications. 
         [0043]    Although specific embodiments of the invention have been described above in detail, the description is merely for purposes of illustration. It should be appreciated, therefore, that many aspects of the invention were described above by way of example only and are not intended as required or essential elements of the invention unless explicitly stated otherwise. Various modifications of, and equivalent steps corresponding to, the disclosed aspects of the exemplary embodiments, in addition to those described above, can be made by a person of ordinary skill in the art, having the benefit of this disclosure, without departing from the spirit and scope of the invention defined in the following claims, the scope of which is to be accorded the broadest interpretation so as to encompass such modifications and equivalent structures.