Abstract:
In various embodiments, a system for providing an LED illumination source on a surface includes a light module comprising (i) an illumination area for receiving one or more light-emitting diodes (LEDs) and (ii) slip joints at first and second ends of the light module, each slip joint comprising a slip joint slot, and at least one bracket for mounting the light module to the surface, the at least one bracket having (i) a fitting frictionally receivable within one of the slip joint slots and (ii) a mounting region engageable to the surface.

Description:
RELATED APPLICATION 
       [0001]    This application claims the benefit of and priority to U.S. Provisional Patent Application No. 61/725,588, filed Nov. 13, 2012, the entire disclosure of which is hereby incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    In various embodiments, the present invention relates to illumination devices, in particular mounting systems for illumination devices incorporating light-emitting diodes. 
       BACKGROUND 
       [0003]    Illumination modules based on light-emitting diodes (LEDs) represent an attractive alternative to incandescent lamps due to their smaller form factor, lower energy consumption, longer operational lifetime, and/or enhanced mechanical robustness. LED light modules also tend to generate less waste heat than incandescent lamps. LED chips approximate point sources of light and may be contained within packages that direct the LED light having a variety of different form factors and sizes. While such design flexibility can lead to innovative products difficult to reproduce with incandescent bulbs, LED lighting modules do present challenges. For example, while LEDs tend to produce less heat than incandescent lighting, they do produce heat that may require dissipation in order to preserve the operational capabilities of the LED light over an expected lifetime. Furthermore, each individual LED or LED-based lighting module may produce insufficient light for particular applications (e.g., illumination of large areas or of paths with complicated footprints or shapes). While multiple LED-based light sources may be utilized in such applications, the packaging for many conventional LED-based light sources is not designed to facilitate the interconnection of several different light sources to form a single illumination region emitting light that is of substantially uniform intensity over its area. 
         [0004]    In light of the foregoing, there is a need for LED-based lighting devices having a modular mounting system that can accommodate multiple LED light modules without risking damage to any of them, facilitate heat conduction away from the modules, and produce uniform illumination, the emission direction of which may be easily changed on a module-by-module basis. 
       SUMMARY 
       [0005]    In accordance with various embodiments of the invention described herein, a mounting system is used to facilitate attachment of multiple LED light modules together and/or to a lighting fixture (e.g., a flat metal surface) that may include a heat sink, thereby forming an illumination system. An illumination system in accordance with the current invention may include multiple LED modules. Each module may include slip joint slots in both ends that connect to another module using, e.g., mounting brackets, thereby allowing a new module to attach to or detach from the illumination system conveniently and with no damage thereto. Each module may be secured, and thus be oriented to emit light, in either the horizontal or vertical direction independent of the orientation of the other modules. Additionally, the distance between each LED module in the illumination system is limited such that the system produces spatially uniform light. 
         [0006]    In one aspect, embodiments of the invention feature a system for providing an LED illumination source on a surface. The system includes or consists essentially of a light module comprising (i) an illumination area for receiving one or more light-emitting diodes (LEDs) and (ii) slip joints at first and second ends of the light module, each slip joint comprising a slip joint slot, and at least one bracket for mounting the light module to the surface, the at least one bracket having (i) a fitting frictionally receivable within one of the slip joint slots and (ii) a mounting region engageable to the surface. 
         [0007]    Embodiments of the invention feature one or more of the following in any of a variety of combinations. The fitting of the at least one bracket may be rotatable within the slip joint slot when frictionally engaged therein. At least a portion of slip joint slot may have a circular shape. A first distance between a center of the circular shape and a first edge of the slip joint may be substantially equal to a second distance between the center of the circular shape and a second edge of the slip joint perpendicular to the first edge of the slip joint. The fitting may include a shaft projecting from the bracket and a disc, affixed to a distal end of the shaft, for sliding into the slip joint slot. The mounting region may include a mounting feature having a flat surface substantially perpendicular to a surface of the disc. The illumination area may include or consist essentially of one or more LEDs disposed beneath a substantially transparent or substantially translucent cover. 
         [0008]    In another aspect, embodiments of the invention feature an illumination system that includes or consists essentially of (a) a plurality of light modules each including or consisting essentially of (i) an illumination area for receiving one or more light-emitting diodes (LEDs) and (ii) slip joints at first and second ends of the light module, each slip joint including a slip joint slot, (b) a first bracket for interconnecting two light modules, the first bracket including or consisting essentially of (i) an arm, (ii) a first disc disposed at a first end of the arm on a first side thereof, (iii) a second disc disposed at the first end of the arm on a second side thereof opposite the first side, the second disc opposing the first disc and being substantially parallel thereto, and (iv) a mounting feature disposed at a second end of the arm, (c) a second bracket for mounting the plurality of light modules to the surface, the second bracket including or consisting essentially of (i) an arm, (ii) a disc disposed at a first end of the arm on a first side thereof, and (iii) a mounting feature disposed at a second end of the arm, and (d) a third bracket for mounting the plurality of light modules to the surface, the third bracket including or consisting essentially of (i) an arm, (ii) a disc disposed at a first send of the arm on a first side thereof, and (iii) a mounting feature disposed at a second end of the arm. When the mounting feature of the third bracket and the mounting feature of the second bracket are disposed on the surface substantially parallel to each other, the discs of the third bracket and the second bracket face in opposite directions. The slip joint slots of the light modules are configured for frictionally and rotatably engaging (i) the first disc of the first bracket, (ii) the second disc of the first bracket, (iii) the disc of the second bracket, and/or (iv) the disc of the third bracket. 
         [0009]    Embodiments of the invention feature one or more of the following in any of a variety of combinations. The illumination areas of at least two light modules may be oriented to emit light in directions substantially perpendicular to each other. The illumination areas of at least two light modules may be oriented to emit light in substantially the same direction. The first disc of the first bracket, the second disc of the first bracket, the disc of the second bracket, and/or the disc of the third bracket may be circular. Any two of (or even all of) the first disc of the first bracket, the second disc of the first bracket, the disc of the second bracket, and/or the disc of the third bracket may have substantially identical diameters. Rach light module may approximately define a regular rectangular solid having the illumination area disposed on one surface thereof. The slip joints of the light module may be disposed at first and second opposing ends of the light module substantially perpendicular to the illumination area. The illumination area may include or consist essentially of one or more LEDs and a curved, substantially transparent or substantially transparent cover disposed over the one or more LEDs. 
         [0010]    These and other objects, along with advantages and features of the invention, will become more apparent through reference to the following description, the accompanying drawings, and the claims. Furthermore, it is to be understood that the features of the various embodiments described herein are not mutually exclusive and can exist in various combinations and permutations. As used herein unless otherwise indicated, the terms “substantially” and “approximately” mean ±10%, and, in some embodiments, ±5%. The term “consists essentially of” means excluding other materials that contribute to function, unless otherwise defined herein. Nonetheless, such other materials may be present, collectively or individually, in trace amounts. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    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. In the following description, various embodiments of the present invention are described with reference to the following drawings, in which: 
           [0012]      FIGS. 1A and 1B  are isometric representations of LED-based lighting modules usable in accordance with various embodiments of the invention; 
           [0013]      FIG. 2  is a depiction of the attachment of the lighting module of  FIG. 1A  to a planar fixture in accordance with various embodiments of the invention; 
           [0014]      FIGS. 3A-3C  are depictions of different mounting brackets usable in accordance with various embodiments of the invention; 
           [0015]      FIG. 3D  is a side-view of the lighting module of  FIG. 1A  in accordance with various embodiments of the invention; and 
           [0016]      FIG. 4  is a depiction of an illumination system feature three lighting modules linked together and mounted to a common fixture in accordance with various embodiments of the invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0017]      FIG. 1A  illustrates an LED light module  100  that has a surface  105  for supporting and securing an LED illumination element  110 , a module body  112 , and two slip joints  115  at opposed ends of the light module body  112 . The slip joints  115  may be portions of the module body  112  as opposed to, e.g., discrete parts attached to module body  112 . In some embodiments the light module  100  has a slip joint on only one end of the module body  112 , and the opposing end may thus not be configured for attachment thereto. As shown in  FIG. 1B , the LED illumination element  110  may include one or more discrete bare-die and/or packaged LEDs  117  that may be disposed beneath a cover  120  (e.g., a substantially transparent or translucent cover such as a lens). (Although  FIG. 1B  illustrates LEDs  117  disposed in a single linear array, embodiments of the present invention include other arrangements of one or more LEDs  117  within the LED illumination element  110 , including two-dimensional regular and pseudo-random arrays.) The slip joints  115  typically each feature a slot  125  that allows the light module  100  to be mounted to a light fixture (e.g., a flat surface such as a metal surface, or a surface within a lamp or other lighting device) or to be connected to another light module  100  via, for example, a mounting bracket as detailed below. 
         [0018]    The light module body  112  preferably contains electronics that transform electrical power into a form suitable to drive the LEDs  117  (e.g., DC current). Light module body  112  may also include dimmers, transformers, rectifiers, or ballasts suitable for operation with the LEDs  117 , as understood by those of skill in the art, and such components (and/or any other circuitry) of light module body  112  may be disposed on a printed circuit board. In preferred embodiments, the light module body  112  also provides for thermal feedback (or “foldback”) to protect the LEDs 117, as described in, e.g., U.S. Pat. No. 7,777,430 and U.S. Patent Application Publication Nos. 2010/0320499, 2010/0176746 (the &#39;6746 application), and 2011/0121760, the entire disclosures of which are incorporated by reference herein. For example, the temperature sensed at the lighting module  100  may be utilized to provide over-temperature protection (i.e., reduction in the power supplied to the LEDs  117 ) and/or switch and control any active cooling system (e.g., a fan) incorporated within light module body  112  via, e.g., thermal control electronics. The light module body  112  may even incorporate features described in the &#39;6746 application to enable two-wire temperature sensing and, thus, the maintaining of the LEDs  117  within a safe operating temperature range. The module body  112  may also contain a power source (e.g., one or more batteries) and/or wiring and/or a socket for interconnection of the module  100  to an external power source (e.g., an AC main). The module body  112  may also include an exterior panel  118  for displaying module-related information such as a part number, a company logo (see  FIG. 2 ), decorative text and/or graphics, etc. 
         [0019]      FIG. 2  depicts an LED light module  100  being secured to a flat fixture  200 . The LED light module  100  is mounted to fixture  200  via two through-hole mounting brackets  210  extending from the module body  112 ; using the brackets  210  and screws  220  (or other fasteners such as nails, staples, etc.), the module  100  is attached to the fixture  200 . As shown, the fixture  200  may incorporate therein or thereon a thermally conductive material such as a heat sink  230 . The heat produced by module  100  during operation may then be effectively conducted away from the LED module  100 . As shown, when module  100  is fastened to the flat fixture  200 , the light emitted from the LED module  100  is typically emitted in only one direction (e.g., the vertical direction away from fixture  200 ); alteration of the light-emission direction typically requires detachment and reattachment of the lighting module  100 . One potential disadvantage of the use of through-hole mounting brackets  210  is their size and lateral extent away from the sides of the module body  112 , which results from the need to accommodate the screw  220  for attachment. Thus, if multiple LED light modules  100  are arranged end-to-end in this manner, the space between each pair of modules  100  is at least two times of the width of the brackets  210 ; this spacing may result in visibly non-uniform light output and/or inefficient utilization of illumination area. 
         [0020]    Referring to  FIGS. 3A-3C , in various embodiments of the present invention, mounting brackets  300 ,  310 ,  320  each have a disc feature  330  on one side or both sides of one end, a flat mounting foot  340  on the other end and an arm  350  therebetween. The disc  330  connects to the arm  350  via a shaft  360  having a cross-sectional diameter or width smaller than the diameter of the disc  330 . As shown, the mounting brackets may have various geometries, for example, a left-facing single-mounting configuration  300 , a multi-mounting configuration  320  with an opposed pair of discs  330 , or a right-facing single-mounting configuration  310 , depending on space requirements and the geometry of the slip joint slots  125 . If one LED light module  100  is sufficient for lighting, the mounting bracket  300  and/or the mounting bracket  310  each having only a single disc  330  on one end may be used to mount the light module  100  to the fixture via the flat mounting foot  340 . The disc  330  first slides into the slip joint slot  125  with the shaft  360  passing through a keyhole  130 . The keyhole  130  has a diameter or width larger than that of the shaft  360  but smaller than that of the disc  330 , so that the disc  330  is retained within the slip joint slot  125 ; desirably, the slip joint slot  125  is wide enough to accommodate the disc  330  but frictionally engages it as the disc  330  is received therein. The flat mounting foot  340  of the bracket  300 ,  310 , or  320  may be mechanically fastened to the fixture or, e.g., a heat sink, using, for example, a screw, nail, staple, or other fastener, thereby securing the light module  100  to the fixture. Once the flat mounting foot  340  is fastened to a surface or fixture, the bracket  300 ,  310 , and/or  320  prevents physical translation of the light module  100  without the light module  100  itself being otherwise fastened (e.g., by an adhesive) to the surface or fixture. At least portions of the slip joint slot  125  and/or the keyhole  130  may each have a circular shape conforming to the disc  330  and the shaft  360 , respectively. With reference to  FIG. 3D , the distance W 1  between the center of the keyhole  130  (or a circular-shaped portion thereof) and a bottom surface  135  of the slip joint slot  125  may be approximately equal to the distance W 2  between the center of the keyhole  130  (or a circular-shaped portion thereof) and a side surface  140  such that LED light modules attached together may be rotatable about a single axis. Thus, light modules  100  having the same orientation will be approximately coplanar even if separated by one or more other light modules  100  having different orientations. Furthermore, the emission directions of the LED light modules  100  may be independently oriented in a vertical direction (e.g., an x-direction) or a horizontal direction (e.g., a y-direction), or any orientation therebetween, thereby generating various focal points of light as desired. 
         [0021]    Referring to  FIG. 4 , if a lighting system  400  requires multiple LED light modules  100 , these modules may be connected by sliding a mounting bracket  320  with discs  330  on both sides into the slip joint slots  125  of adjacent modules  100 . The orientation of the light modules  100  (and consequently, the primary emission direction of the LED light therefrom) may be arranged independently, thereby generating various focal points of light. For example, as illustrated in  FIG. 4 , light modules  100 - 1  and  100 - 3  emit vertical light (in the x-direction) and light module  100 - 2  emits horizontal light (in the y-direction). Additionally, because the end-to-end distance between the consecutive light fixtures is limited (approximately a width D of the bracket arm  350 , as shown in  FIG. 3C ), the LED light generated by the integrated lighting system  400  is uniform and distributed evenly. Further, because a new module may be attached to an existing module by simply sliding the slip joint slot onto the free disc of the mounting bracket  320 , embodiments of the current invention obviate the need for disassembly of the existing system  400  when expanding it, thereby preventing potential damage to the light modules and/or sensitive optics therein. In one embodiment, various parameters of the module  100 , such as the size of the slip joint slot, and/or the geometry of the mounting bracket, such as the diameter of the disc and the width and length of the arm, are standardized such that various sizes of light modules with standardized slot sizes may be integrated together into a single illumination system. 
         [0022]    At both ends of the lighting system  400 —i.e., the slip joint slots  125  that do not connect to other light modules—a mounting bracket  300  and/or a mounting bracket  310  that has a disc  330  on one side only may be received within slots and then used to mount the entire lighting system  400  to a fixture via flat mounting feet  340 . The flat mounting feet  340  of the mounting brackets  320  that each connect two light fixtures  100  together may be mechanically fastened to the fixture to provide additional support for the weight of lighting system  400  and to dissipate at least some of the heat generated by the modules  100 . If it is desirable to attach a new module to the existing chain of modules, one of the mounting brackets  300 ,  310  may first be detached from the fixture and replaced by a bracket  320  that has two discs  330 . 
         [0023]    The terms and expressions employed herein are used as terms of description and not of limitation, and there is no intention, in the use of such terms and expressions, of excluding any equivalents of the features shown and described or portions thereof, but it is recognized that various modifications are possible within the scope of the invention claimed.