Patent Abstract:
The present invention relates generally to a light emitting diode lighting fixture. In one embodiment, the light fixture includes an extrusion, a plurality of light emitting diodes (LEDs) and a lens coupled to the extrusion. The plurality of LEDs has a uniform spacing between each one of the plurality of LEDs along the extrusion.

Full Description:
FIELD OF THE INVENTION 
     The present invention relates generally to a lighting fixture, and more specifically, to lighting fixtures that utilize light emitting diodes. 
     BACKGROUND OF THE INVENTION 
     Current light emitting diode (LED) lighting technology creates issues of glare and uniformity when designed to be longer than that of a typical extrusion. When two or more light fixtures currently used in the prior art are connected, they are typically not connected end to end. Moreover, the LEDs are not spaced evenly, i.e. there is an offset in the lighting pattern. The lack of symmetry may create undesirable lighting properties. In addition, hot spots may be created along the light fixture. 
     In addition, current LED lighting technology is generally difficult to mount in existing cabinets, coves or under cabinets where mounting is difficult. For example, the use of external brackets is not easily accessed. Moreover, the external brackets may add undue height to the overall fixture size. 
     SUMMARY OF THE INVENTION 
     The present invention relates generally to a light emitting diode lighting fixture. In one embodiment, the light fixture comprises an extrusion, a plurality of light emitting diodes (LEDs) having a uniform spacing between each one of said plurality of LEDs along said extrusion and a lens coupled to said extrusion. 
     The present invention also provides an end-to-end connector for coupling multiple light fixtures. In one embodiment, the end-to-end connector comprises a spacer, a first side coupled to said spacer for coupling to a first light fixture, said first side comprising a first one or more connecting pins coupled to said first side of said spacer and a first one or more alignment posts coupled to said first side of said spacer and a second side coupled to said spacer for coupling to a second light fixture, said second side comprising a second one or more connecting pins coupled to said first side of said spacer and a second one or more alignment posts coupled to said first side of said spacer. 
     The present invention also provides a second embodiment for an end-to-end connector for coupling multiple light fixtures. In one embodiment, the end-to-end connector comprises a first interface for coupling to a first light fixture, a flexible cord coupled to said first interface and a second interface for coupling to a second light fixture, wherein said end-to-end connector aligns said first light fixture and said second light fixture in parallel. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments. 
         FIG. 1  depicts a top view of one embodiment of a light fixture; 
         FIG. 2  depicts a side view of one embodiment of the light fixture; 
         FIG. 3  depicts a front view of one embodiment of the light fixture; 
         FIG. 4  depicts a side view of one embodiment of an end-to-end connector; 
         FIG. 5  depicts one embodiment of the end-to-end connector coupling two LED light fixtures; 
         FIG. 6  depicts one embodiment of a flex connector; 
         FIG. 7  depicts one embodiment of multiple light fixtures coupled via the end-to-end connector and the flex connector; and 
         FIG. 8  depicts one embodiment of a relationship defining a distance between a light emitting diode and a mounting hole. 
     
    
    
     To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. 
     DETAILED DESCRIPTION 
       FIG. 1  illustrates a top view of one embodiment of a light fixture  100 . In one embodiment, the light fixture comprises a plurality of light emitting diodes (LEDs)  102 , mounting holes  104 , a lens  106  and an extrusion  108 . Although  FIG. 1  illustrates the light fixture  100  having only two LEDs  102  and two mounting holes  104 , one skilled in the art will recognize that the light fixture  100  may have any number of LEDs  102  and mounting holes  104 . 
     In one embodiment, the plurality of LEDs  102  are uniformly spaced. This provides a symmetric illumination pattern on a targeted illumination area and prevents hot spots from forming along the light fixture  100 . The uniform spacing may be any length that maintains symmetric illumination patterns and that does not generate any shadowing or dark spots on the targeted illumination area. In one embodiment, the uniform spacing between each one of the plurality of LEDs  102  may be between 100 millimeters (mm) to 500 mm. For example, the uniform spacing between each one of the plurality of LEDs  102  may be approximately 200 to 300 mm. 
     In one embodiment, the light fixture  100  also includes one or more mounting holes  104 . Notably, the mounting holes  104  are designed into the light fixture  100 . More specifically, the mounting holes  104  are located through the lens  106  and the extrusion  108 . This allows the light fixture  100  to have an ultra low profile that is advantageous for cabinet lighting, under cabinet lighting and cove lighting. In other words, the light fixture  100  does not require additional external brackets that add to an overall height profile of the light fixture  100 . 
     In addition, the mounting holes  104  are strategically placed in the light fixture  100 . More specifically, the mounting holes  104  are spaced relative to the plurality of LEDs  102  such that a light output of each one of the plurality of LEDs  102  is not hindered. For example, the mounting holes  104  are positioned to maximize optical efficiency of the plurality of LEDs  102 . For example, proper placement of the mounting holes  104  prevents glare from the plurality of LEDs  102 . In addition, the mounting holes  104  are positioned to prevent shadowing effects and dark spots on the targeted illumination area. 
     In one embodiment, the relationship of the distance (d) of the mounting holes  104  with respect to the plurality of LEDs  102  may be approximately given as follows in Equation (1):
 
TAN(90−σ)= h/d   (1)
 
     One embodiment of Equation (1) is illustrated by  FIG. 8 .  FIG. 8  illustrates one of the plurality of LEDs  102  (hereinafter referred to interchangeably as LED  102 ) and one of the mounting holes  104  (hereinafter referred to interchangeably mounting hole  104 ) placed adjacent to the LED  102 . The LED  102  sits on top of the extrusion  108  and under the lens  106 . 
     In Equation (1) illustrated in one embodiment by  FIG. 8 , h represents a height of the mounting hole  104  from a top of the extrusion  108 , d represents the distance between the LED  102  and the mounting hole  104 . The symbol σ represents a viewing angle of light from the LED  102 . The symbol a may also represent a viewing angle of light from a combination of the LED  102  and a secondary optic (not shown). For example, a may be an angle of light emitted from the LED  102  spanning from a vertical axis represented by a dashed line  802  of light emitted by one of the plurality of LEDs  102  to the top of the mounting hole  104  represented by a dashed line  804 . The term  90 −σ represents the angle of light blocked by the height of the mounting hole  104 . 
     Generally, the height h of the mounting hole  104  is known. Thus, a may be calculated based on a given height h of the mounting hole  104 . As a result, an approximate distance d for achieving the design goals may be calculated by re-writing Equation (1) above, as follows in Equation (2):
 
 d=h /TAN(90−σ)  (2)
 
In Equation (2), h is a known height of the mounting hole  104  and a may be calculated based on the known height of the mounting hole  104 .
 
     Also adding to the ultra low profile of the lighting fixture  100  is the design of the lens  106  and the extrusion  108 .  FIG. 2  illustrates a side view of the lighting fixture  100  that helps to illustrate the design profile of the lens  106  and the extrusion  108 . In one embodiment, a height  202  of the lens  106  is greater than a height  204  of the extrusion  108 . In other words, the ratio of the height  202  of the lens  106  to the height  204  of the extrusion  108  is greater than one. In addition, a combined height  206  of the height  202  of the lens  106  and the height  204  of the extrusion is less than one inch. In one embodiment, the combined height may be less than 0.5 inches. 
     In achieving the above height ratio between the lens  106  and the extrusion  108 , the extrusion  108  may function as a flat heat sink. The thickness of the heat sink, and thereby the extrusion  108 , may be a function of a spacing length of the uniform spacing the plurality of LEDs  102 . For example, as the length of the uniform spacing between the plurality of LEDs  102  increases, the thickness of the heat sink and the extrusion  108  will decrease. Conversely, as the length of the uniform spacing between the plurality of LEDs  102  decreases, the thickness of the heat sink and the extrusion  108  will increase. 
     In one embodiment the lens  106  may be fabricated from polycarbonate. However, one skilled in the art will recognize that any optical grade material may be used. 
     In addition, the lens  106  may include various optical features depending on the application of the lighting fixture  100 . In one embodiment, a masking (now shown) may be applied on both sides along a length of the lens  106 . The masking helps to achieve a narrower angle of light output from the plurality of LEDs  102  and helps to prevent glare. 
     In addition, a color added pigment recipe may be included in the lens  106  depending on the various lighting requirements. The pigment may be used to precisely control the direction of the photons emitted from the plurality of LEDs  102 . For example, the pigment may help to spread light more uniformly over a wider distance at a cost of lower efficiency. 
     The lens  106  may also be any shape in accordance with a desired application of the light fixture  100 . In one embodiment, the lens  106  is a hemisphere shape to achieve the greatest pass through of light outputted by the plurality of LEDs  102 . However, one skilled in the art will recognize that the lens  106  may be a different shape, for example, depending on if one desires the light output of the plurality of LEDs  102  to be wider or narrower. 
       FIG. 3  illustrates a front view of one end  300  of the light fixture  100 .  FIG. 3  also helps to illustrate the ultra low profile (i.e. the combined height  206  of the lens  106  and the extrusion  108  of the light fixture  100 , as described above. One skilled in the art will recognize that an opposing end of the light fixture  100  will be substantially similar to the end  300  illustrated in  FIG. 3 . 
     In one embodiment, the end  300  comprises one or more holes  302  for receiving an alignment post of an end-to-end connector described below. The end  300  also comprises one or more holes  304  for receiving a connecting pin of the end-to-end connector, also further described below. The end  300  of the lighting fixture  100  is designed such that multiple light fixtures  100  may be coupled together in an end-to-end fashion. In doing so, an end-to-end connector is used to allow the uniform spacing of the plurality of LEDs  102  to be maintained between the multiple light fixtures  100 . 
       FIG. 4  illustrates one embodiment of an end-to-end connector. The end-to-end connector  400  comprises a spacer  406 , a first side  410  coupled to the spacer  406  for coupling to a first light fixture  100  and a second side  412  coupled to the spacer  406  for coupling to a second light fixture  100 . The spacer  406  may be made of any material. The spacer  406  may have a width such that when connecting two light fixtures  100 , the LEDs  102  maintain a uniform spacing across the two light fixtures  100 . 
     The first side  410  and the second side  412  each comprises one or more alignment posts  402  and one or more connecting pins  404  coupled to the respective side. The alignment posts  402  are designed to bear most of stress and weight of the connection to a lighting fixture  100  as the connecting pin  404  may generally be a more delicate piece of hardware. In addition, the alignment posts  402  provide for easier alignment between the end-to-end connector  400  and the light fixture  100 . As discussed above, the alignment posts  402  mate with the holes  302 . Similarly, the connecting pins  404  mate with the holes  304 . As a result, a flush connection is achieved between the light fixture  100  and the end-to-end connector  400 . In one embodiment, the alignment posts  402  may be a single post that is pushed through the first side  410 , the spacer  406  and the second side  412 .  FIG. 5  illustrates one embodiment of the end-to-end connector  400  coupled to two light fixtures  100 A and  10 B. 
     An important feature of the end-to-end connector  400  is that it maintains uniform spacing of the plurality of LEDs (not shown) between the multiple light fixtures  100 A and  100 B, as discussed above. More specifically, the uniform spacing is maintained between a last one of the plurality of LEDs (not shown) of a first light fixture  100 A and a first one of the plurality of LEDs (not shown) of a second light fixture  100 B. In other words, a length between each one of the LEDs across the first light fixture  100 A and the second light fixture  100 B is the same. Notably, multiple spacers  406  may be used to connect any number of light fixtures  100  end-to-end while maintaining uniform spacing between all of the LEDs. 
     In one embodiment, this is achieved by the spacer  406 . Referring back to  FIG. 4 , a width  408  of the spacer  406  is a function of the desired uniform spacing between a plurality of LEDs of each light fixture  100 A and  100 B. For example, if the desired uniform spacing is approximately 275 mm, then the width  408  of the spacer  406  would be the precise length required to maintain the uniform 275 mm spacing between the last one of the LEDs of a first light fixture  100 A and the first one of the plurality of LEDs of a second light fixture  10 B. This may be repeated with numerous light fixtures  100  and end-to-end connectors  400  over a long length, for example, over 20 feet. Thus, the width  408  of the spacer  406  may be manufactured in various sizes in accordance with the desired uniform spacing between the plurality of LEDs across multiple light fixtures  100 A and  10 B. 
       FIG. 6  illustrates a second embodiment of an end-to-end connector  600  used with the light fixture  100  described herein. The end-to-end connector  600  includes a first interface  606  for coupling to a first light fixture  100  and a second interface  608  for coupling to a second light fixture  100 . The first interface  606  and second interface  608  are coupled to a flexible cord  610 . Thus, the end-to-end connector  600  may be used to run parallel rows of light fixtures  100  in conjunction with the end-to-end connector  400  described above. 
     In one embodiment, the first interface  606  may comprise one or more alignment posts  602  and one or more connecting pins  604 . Similar to the end-to-end connector  400 , the alignment posts  602  are designed to bear most of stress and weight of the connection to a lighting fixture  100  as the connecting pin  604  may generally be a more delicate piece of hardware. In addition, the alignment posts  602  provide for easier alignment between the end-to-end connector  600  and the light fixture  100 . As discussed above, the alignment posts  602  mate with the holes  302 . Similarly, the connecting pins  604  mate with the holes  304 . As a result, a flush connection is achieved between the light fixture  100  and the end-to-end connector  600 . The second interface  608  may also comprise one or more alignment posts  602  and one or more connecting pins  604 . 
     The end-to-end connector  600  also serves to maintain uniformity. In one embodiment, the end-to-end connector  600  aligns light fixtures  100  in parallel, as discussed above. For example, this is illustrated by  FIG. 7 . In  FIG. 7 , end-to-end connector  600  is coupled to light fixtures  100 A and  10 B. The flexible cord  610  allows the end-to-end connector  600  to bend, thereby, running light the fixtures  100 A and  100 B in parallel. Notably, the light fixtures  100 A and  100 B are aligned vertically. That is each one of the plurality of LEDs  102 A are vertically aligned with the LEDs  102 B, thus maintaining a symmetric illumination pattern. 
     In addition,  FIG. 7  illustrates the end-to-end connector  400  connected to the light fixture  100 A and the light fixture  100 C. As discussed above, the end-to-end connector  400  maintains a uniform spacing between the last or furthest right LED  102 A of the light fixture  100 A and the first or furthest left LED  102 C of the light fixture  100 C. That is the spacing between each one of the LEDs  102 A and  102 C is uniform, even between the LED  102 A and the LED  102 C across the end-to-end connector  400 . 
     Alternatively, the end-to-end connector  600  may be sized to achieve the same functionality as the end-to-end connector  400 . In other words, the end-to-end connector  600  may be sized to be used interchangeably with the end-to-end connector  400 , if necessary, to maintain a uniform spacing between the plurality of LEDs  102 A and  102 C. 
     While various embodiments have been described above, it should be understood that they have been presented by way of example only, and not limitation. Thus, the breadth and scope of a preferred embodiment should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.

Technology Classification (CPC): 5