Patent Publication Number: US-10309637-B2

Title: Low profile light with improved thermal management

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The present application claims priority of U.S. Provisional Application No. 62/006,166, entitled “LOW PROFILE LIGHT WITH IMPROVED THERMAL MANAGEMENT” and filed Jun. 1, 2015, the entire contents of which are hereby incorporated by reference. 
    
    
     TECHNICAL FIELD 
     The present invention relates to lighting, and more specifically, to low profile lights including solid state light sources. 
     BACKGROUND 
     Increased usage of solid state light sources (such as but not limited to light emitting diodes (LEDs), organic light emitting diodes (OLEDs), polymer light emitting diodes (PLEDs), organic light emitting compounds (OLECs), and the like, including combinations thereof) has resulted in the creation of many lighting devices that take advantage of the benefits of these light sources. One such lighting device is a low profile lighting device, which typically (but not always) occupies a recessed ceiling fixture, but has a low profile portion that sits beneath the ceiling, small enough to minimize disruptiveness and maintain aesthetics. Thus, it does not intrude very far into the room. 
     Such lights typically use thermal management elements designed to put as much heat as possible outside of the recessed ceiling fixture—that is, beneath the ceiling, where ambient air is available. In addition to removing the need to use a typical large, multiple-finned heat sink, this design also allows the low profile light to be installed within a junction box, instead of a recessed ceiling fixture, in locations where a recessed ceiling fixture is not available. 
     SUMMARY 
     Conventional techniques for managing heat in low profile lighting devices suffer from a variety of deficiencies. For example, the thermal elements and structure of such devices to bring heat to the outside ambient air are either complicated and expensive, or are somewhat limited in the amount of heat they can dissipate; i.e., they are not as efficient. Complicated systems are not desirable in such lights, due to the potentially limited space in which the light is installed, and the desire to keep the profile of the light that is exposed beneath a surface such as a ceiling to a minimum for aesthetic reasons. 
     Embodiments improve such lights by extending one or more fins up (that is, above the ceiling) from the housing of the low profile light without removing the ability to install the low profile light within a junction box. The fin(s) and the housing are manufactured as a single part. This(these) fin(s) does(do) not like a traditional finned heat sink and, particularly in embodiments where the fin(s) correspondingly surround a driver housing, maintain a clean look for the light while showing improved heat dissipation. 
     In an embodiment, there is provided a low profile light. The low profile light includes: one or more solid state light sources; a cover disposed in relation to the one or more solid state light sources such that light emitted by the one or more solid state light sources passes through the cover; a driver to supply electrical power to the one or more solid state light sources, wherein the driver is contained within a driver housing; and a housing including: a central portion having a first side and a second side; a lip, wherein the lip extends around an outer edge of the housing; a cover receptacle configured to receive the cover; an outer face, wherein the outer face extends from the lip inward towards the cover receptacle; an inner surface, wherein the inner surface extends downward away from the central portion and upward towards the lip, so as to form a valley; and a fin, extending perpendicularly up from the central portion. 
     In a related embodiment, the central portion of the housing may be substantially flat. In another related embodiment, the central portion of the housing may be substantially flat on the first side. In a further related embodiment, the central portion of the housing may include a raised portion on the second side. In a further related embodiment, the raised portion may include a Y-shaped raised portion formed of three legs, the three legs meet at a center of the second side of the central portion, and the three legs each extend beyond the central portion to an inner edge of the lip. 
     In still another related embodiment, the one or more solid state light sources may be coupled to the first side and the driver housing may be coupled to the second side. In yet another related embodiment, the fin may be integrally formed with the central portion of the housing. In a further related embodiment, the fin may be shaped to at least partially surround a portion of the driver housing. In another further related embodiment, the fin may be substantially curved. In a further related embodiment, the driver housing may be correspondingly curved. 
     In another further related embodiment, the fin may include a first fin and a second fin, the first fin may be shaped to at least partially surround a first portion of the driver housing and the second fin may be shaped to at least partially surround a second portion of the driver housing. In a further related embodiment, the second fin may include a first raised portion, a second raised portion, and a connecting portion that joins the first raised portion to the second raised portion. In a further related embodiment, the connection portion may be lower in height than the first raised portion and the second raised portion. In a further related embodiment, the lowered height of the connection portion may be configured to receive a wire extending from the driver housing to a power source for the low profile light. 
     In still yet another related embodiment, the central portion, the lip, the cover receptacle, the outer face, the inner surface, and the fin may be integrally formed. In a further related embodiment, the central portion, the lip, the cover receptacle, the outer face, the inner surface, and the fin may be integrally formed of the same material. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing and other objects, features and advantages disclosed herein will be apparent from the following description of particular embodiments disclosed herein, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles disclosed herein. 
         FIG. 1  shows a rear ceiling facing perspective view of a low profile light according to embodiments disclosed herein. 
         FIG. 2  illustrates various components of the low profile light of  FIG. 1 , including how they fit together, according to embodiments disclosed herein. 
         FIG. 3  shows a rear ceiling facing perspective view of an embodiment of the housing of the low profile light according to embodiments disclosed herein. 
         FIGS. 4A-4B  show other rear ceiling facing views of embodiments of the housing of the low profile light according to embodiments disclosed herein. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  shows a low profile light  100  from a rear, ceiling facing perspective view. That is, the portion of the low profile light  100  shown in  FIG. 1  would generally not be visible when the low profile light  100  was installed, either in a recessed luminaire housing, a junction box, or the like. Because lighting devices such as the low profile light  100  are typically installed in a ceiling, so as to illuminate an area beneath the ceiling, this view is said to be a ceiling facing view. However, this term is used for convenience of description only and is not limiting. That is, a low profile light according to embodiments described throughout may be installed in other surfaces that are not ceilings. The view shown in  FIG. 1 , whatever the surface the low profile light  100  is installed in, is the portion generally not visible. The low profile light  100  includes one or more solid state light sources  102  and a cover  104  (both not visible in  FIG. 1  but shown in  FIG. 2 ). The cover  104  is disposed in relation to the one or more solid state light sources  102 , such that light emitted by the one or more solid state light sources  102  passes through the cover  104 . The cover  104 , in some embodiments, is made of a semi-transparent, diffusive material. The low profile light also includes a driver  106 , which is contained within a driver housing  108 . Due to the driver housing  108 , it is not possible to see the driver itself  106  in  FIG. 1 . The driver  106  is any driver or power supply that supplies electrical power to the one or more solid state light sources  102 . The driver  106  itself receives power via a wire  109 , which in some embodiments as shown in  FIG. 1  is attached to a screw base  110  capable of interfacing with a typical electrical lamp socket. 
     The low profile light  100  also includes a housing  120 . The housing  120  provides structure for the low profile light  100 . The housing  120  includes a central portion  122  and a lip  124 . The central portion  122  has a first side  126  (not shown in  FIG. 1  but shown in  FIG. 2 ) and a second side  128 . The lip  124  extends around an outer edge  128  of the housing  120 . The housing  120  also includes a cover receptacle  130  configured to receive the cover  104  and an outer face  132  (neither shown in  FIG. 1  but shown in  FIG. 2 ). The outer face  132  extends from the lip  124  inward towards the cover receptacle  130 . The housing  120  also includes an inner surface  134 , which extends downward away from the central portion  122  and upward towards the lip  124 , so as to form a valley  136 , as seen in  FIG. 1 . The housing  120  also includes a fin  138 , which extends perpendicularly up from the central portion  122 . 
     The central portion  122 , in some embodiments, is substantially flat. As shown in  FIG. 2 , in some embodiments, the central portion  122  is substantially flat on the first side  126 . Similarly, in some embodiments as shown in  FIGS. 3, 4A, and 4B , the second side  128  of the central portion  122  includes a raised portion  140 . In some embodiments, as shown in  FIGS. 3, 4A, and 4B , the raised portion  140  is a Y-shaped raised portion  140  formed of three legs  142 ,  144 ,  146 . The three legs  142 ,  144 ,  146 , in some embodiments, meet at a center  148  of the second side  128  of the central portion  122 . In some embodiments, the three legs  142 ,  144 ,  146  each terminate at the central portion  122 . The three legs  142 ,  144 ,  146 , in some embodiments, each extend beyond the central portion  122  to an inner edge  148  of the lip  124 . The three legs  142 ,  144 ,  146  provide structural support for the housing  120  as well as enabling various connection systems (not shown) for the low profile light  100 . 
       FIG. 2  shows an embodiment of the low profile light  100  with some of its component parts separated, so as to show how these connect together. Thus,  FIG. 2  includes the cover  104 , the one or more solid state light sources  102 , the housing  120 , the driver housing  108  (with the driver  106  contained therein), and the wire  109  with attached screw base  110 . As seen in  FIG. 2 , the one or more solid state light sources  102  are coupled to the first side  126  of the central portion  122  and the driver housing  108  is coupled to the second side  128  of the central portion  122 . 
     As shown throughout the figures, the fin  138  is integrally formed with the central portion  122  of the housing  120 . In other words, the fin  138  is not a separate part of the housing  120  that could be mechanically unattached and then reattached without anything more. To remove the fin  138  from the housing  120  would require breaking the fin  138  off of the housing  120 . In some embodiments, all of the components of the housing (i.e., the central portion  122 , the lip  124 , the cover receptacle  130 , the outer face  132 , the inner surface  134 , and the fin  138 ) are all integrally formed as a single piece. In some embodiments, the central portion  122 , the lip  124 , the cover receptacle  130 , the outer face  132 , the inner surface  134 , and the fin  138  are integrally formed of the same material, such as but not limited to any known type of metal or plastic. 
     As shown throughout the figures but most clearly in  FIG. 3 , the fin  138  of the housing  120  is, in some embodiments, substantially curved. As shown in  FIGS. 1 and 2 , in some embodiments, the driver housing  108  is correspondingly curved. That is, an arc of the fin  138  is similar to an arc of the driver housing  108 . As is seen in  FIGS. 1 and 2 , in some embodiments, the entirety of the driver housing  108  is not curved, but only portions thereof. 
       FIGS. 4A and 4B  show embodiments of the low profile light  100  that include a first fin  138  and a second fin  139 . As shown the first fin  138  is shaped to at least partially surround a first portion  108 - 1  of the driver housing  108 . Similarly, the second fin  139  is shaped to at least partially surround a second portion  108 - 2  of the driver housing  108 . In some embodiments, as shown in  FIGS. 4A and 4B , the second fin  139  comprises a first raised portion  900 , a second raised portion  901 , and a connecting portion  902 . The connecting portion  902  joins the first raised portion  900  to the second raised portion  901 . In some embodiments, the connecting portion  902  is lower in height than the first raised portion  900  and the second raised portion  901 . In some embodiments, the connecting portion  902  is lower in height than one of the first raised portion  900  and the second raised portion  901 . In some embodiments, the connecting portion  902  is substantially the same height as one of or both of the first raised portion  900  and the second raised portion  901 . In some embodiments, the lowered height of the connecting portion  902  is configured to receive the wire  109  extending from the driver housing  108  to a power source for the low profile light  100 . 
     Though embodiments have been described as having one or two fins, embodiments are not so limited. Indeed, any number of perpendicularly extending fins that are integrally formed with the central portion of the housing are possible without departing from the scope of this disclosure. 
     Measurements were taken of two versions of a low profile light according to embodiments disclosed herein. One version required 10 W to operate and the other version required 13 W to operate. Each version was tested while lacking one or more upwardly extending fins as disclosed herein, and while having such one or more such fins. The measurements are shown in Table 1 below and indicate a drop in temperature both at the one or more solid state light sources and at the housing. 
     
       
         
           
               
               
               
               
               
             
               
                 TABLE 1 
               
               
                   
               
               
                   
                 Temperature at 
                   
                   
                   
               
               
                   
                 one or more 
                   
                   
                   
               
               
                   
                 solid state light 
                 Temperature at  
                 Change  
                 Change  
               
               
                   
                 sources (T1) 
                 housing (T2) 
                 in T1 
                 in T2 
               
               
                   
               
             
            
               
                 10 W, no fin 
                 52.8° C. 
                 38.8° C. 
                   
                   
               
               
                 10 W, with fin 
                 50.6° C. 
                   37° C. 
                 2.2° C. 
                 1.8° C. 
               
               
                 13 W, no fin 
                 61.1° C. 
                 44.9° C. 
                   
                   
               
               
                 13 W, with fin  
                 57.9° C. 
                 42.2° C. 
                 3.2° C. 
                 2.7° C. 
               
               
                   
               
            
           
         
       
     
     Unless otherwise stated, use of the word “substantially” may be construed to include a precise relationship, condition, arrangement, orientation, and/or other characteristic, and deviations thereof as understood by one of ordinary skill in the art, to the extent that such deviations do not materially affect the disclosed methods and systems. 
     Throughout the entirety of the present disclosure, use of the articles “a” and/or “an” and/or “the” to modify a noun may be understood to be used for convenience and to include one, or more than one, of the modified noun, unless otherwise specifically stated. The terms “comprising”, “including” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. 
     Elements, components, modules, and/or parts thereof that are described and/or otherwise portrayed through the figures to communicate with, be associated with, and/or be based on, something else, may be understood to so communicate, be associated with, and or be based on in a direct and/or indirect manner, unless otherwise stipulated herein. 
     Although the methods and systems have been described relative to a specific embodiment thereof, they are not so limited. Obviously many modifications and variations may become apparent in light of the above teachings. Many additional changes in the details, materials, and arrangement of parts, herein described and illustrated, may be made by those skilled in the art.