Abstract:
A lightweight and thermally efficient LED lighting module is disclosed for recessed down light can retrofits, or as new down light installations mountable to different size junction boxes consisting of a combination heat sink and trim ring unitary metal dish for the attachment of at least one LED array mounted to a circuit board, or at least one chip-on-board or COB LED array, further including at least two removable springs or clips, junction box mounting screw clearance holes, an optional external dimmable LED driver, and a diffusion lens cover installed to the front of the LED lighting module.

Description:
PRIORITY DOCUMENT 
       [0001]    This patent application claims priority of Provisional Patent Application No. 61/978,313 entitled, “Lightweight and thermally efficient LED down light” filed on Apr. 11, 2014. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates generally to a lightweight LED lighting module with improved thermal efficiency that can be used in retrofit recessed down light can applications or for new down light installations. 
       BACKGROUND OF THE INVENTION 
       [0003]    Incandescent tungsten filament lamps were the first source of light that was created. These incandescent lamps were later used on dimmers that controlled the amount of power going into the lamps to provide dimming of the light output and for energy savings. HID or metal halide lamps and fluorescent lamps were later discovered that offered increased lamp life and brighter outputs over the incandescent lamps. These HID or fluorescent lamps operated with a ballast that first ignited an arc and then limited the power to the lamp to keep the arc operating. Certain HID or fluorescent lamps could be used with special dimming ballasts that could be dimmed for additional energy savings. 
         [0004]    More recently, advances in LED brightness and efficacy have allowed LED lamps and LED modules to be developed that could offer even longer lamp life and brighter outputs when properly configured, to compete with HID or fluorescent lamps. A driver is used to provide the correct power to the LEDs either through PWM, constant voltage, or constant current. The LED lamps and LED modules could be hard-wired directly to the driver in an internal or external configuration, or can be eliminated with the use of dimmable AC LEDs and special IC chips. The drivers could be made dimmable for use with the already inherent nature of energy savings provided by the LEDs. 
         [0005]    For new designs and ease of retrofits, it is desirable to have one LED light or LED module that can be installed into existing incandescent, compact fluorescent or HID fixtures to ultimately create a longer lasting and energy efficient LED light fixture. 
         [0000]    The present invention provides for an LED light or LED module that allows an end user to have a retrofit LED lamp option to existing halogen, compact fluorescent, or HID fixtures. The same present invention also provides for an LED light or LED module option that allows an end user to readily install a new LED light or LED module as a recessed down light for new installations. 
         [0006]    Lastly, the present invention will provide for a thermally efficient, better, and lightweight LED light that can be installed in multiple applications including new recessed down light installations with very low ceiling height clearances. 
       DESCRIPTION OF THE RELATED ART 
       [0007]    Companies including Lighting Science Group and Commercial Electric for Home Depot among many others, offer LED down light fixtures that can be use in existing fixtures as retrofits or as an LED fixture in new recessed down light installations. However, all of these models use external bulky and heavy heat sinks attached to a separate plate positioned at the rear of the fixtures to provide cooling for the LEDs. The additional heat sinks add extra and unnecessary weight, and additional cost to the fixtures. The height of the heat sink in some fixtures also makes the LED down light fixtures higher than necessary, thereby preventing its use in very low profile ceiling or wall mount applications. Some background on a typical two piece configuration for a recessed LED down light can be found in U.S. Pat. No. 8,201,968 issued to Maxik et al. titled, “Low Profile Light” and assigned to Lighting Science Group Corporation, and also in U.S. Pat. No. 8,672,518 issued to Boomgaarden et al. titled, “Low Profile Light and Accessory Kit for the same” that is also assigned to Lighting Science Group Corporation. 
         [0008]    The present invention is an improvement over other inventions. It uses a single unitary metal dish preferably made of aluminum for better thermal conductivity and makes the overall LED fixture more lightweight. The metal dish can be made from different manufacturing processes including, but not limited to deep draw, stamping, spinning, metal forming, and other methods for making this multipurpose combination heat sink and trim assembly for the mounting of an LED board or LED arrays. This metal dish eliminates the need for having a separate trim ring and heat sink, thereby reducing overall weight and cost of the LED light or LED module. Having a single piece also allows for better thermal conductivity of the LED board or LED arrays where heat from the LEDs are cooled directly by the metal dish into the trim ring of the LED light or LED module without the need to go through multiple surfaces offering better and more efficient thermal transfer. In addition, the metal dish also serves as the means for mounting the entire LED light or LED module to a junction box for new installation applications, or the attachment of removable metal springs or clips and brackets for retrofit applications into existing lighting down light can fixtures. 
         [0009]    The device of the present invention consists primarily of a main metal dish. The main metal dish serves multiple purposes. Primarily, it serves as an immediate surface in which to mount an LED printed circuit board or a COB or chip-on-board LED module array, and serve as a thermally conductive heat sink. The circuit board contains at least one string of LEDs or LED arrays. Likewise the COB may contain at least one string of LEDs or LED arrays. The second purpose is to provide a decorative trim ring for LED light fixture for retrofit and new installation applications. Lastly, the main metal dish contains screw clearance holes for mounting to different size junction boxes for new installations, and also has provisions on it for the mounting of removable brackets, clips, and springs, or for the attachment of only springs provided for retrofitting the complete LED light assembly into an existing recessed down light can. Provisions are also provided on the main metal dish for the mounting of an LED light engine, an optional external driver, and a diffusion lens. 
         [0010]    The preferred embodiment of the present invention consists of a main combination heat sink and trim ring metal dish, removable mounting clips or springs, LED light engine, diffusion lens, and an external AC to DC dimmable LED driver. 
         [0011]    An alternate embodiment of the present invention consists of a main combination heat sink and trim ring metal dish, removable mounting clips or springs, dimmable AC LED light engine with internal controller, and a diffusion lens. 
       SUMMARY OF THE INVENTION 
       [0012]    The device of the present invention includes in its most basic form, a main metal dish, removable springs, an LED light engine, an optional LED driver, and a diffusion snap-in lens. 
         [0013]    The preferred embodiment is therefore a dimmable device that has a. combination heat sink and trim ring main metal dish for mounting an LED circuit board or LED light engine to one side of the dish. The circuit board contains at least one string of LEDs or LED arrays. Likewise the COB may contain at least one string of LEDs or LED arrays. Removable brackets containing springs or separate spring clips are attached to the opposite side of the dish for allowing the LED fixture to be installed into an existing down light can in a retrofit application. For new installations of the LED fixture mounted straight to a junction box, the removable brackets containing the springs or separate spring clips are not used. An optional AC to DC dimmable driver is mounted on the same side as the removable brackets containing springs or separate spring clips. This external LED driver is then connected to the LED light engine consisting of at least one string of LEDs or LED arrays mounted to a circuit board, or a chip-on-board (COB) LED array. Lastly, a separate diffusion lens made preferably out of plastic to maintain an overall lower weight to the LED fixture is attached to the main metal dish on the same side as the LED light engine to protect the LEDs from dust and damage and also to diffuse the light that is emitted out the front of the LEDs mounted to a circuit board. 
         [0014]    The alternate embodiment is therefore a dimmable device that has a. combination heat sink and trim ring main metal dish for mounting a dimmable AC LED circuit board or dimmable AC LED light engine to one side of the dish. The circuit board contains at least one string of AC LEDs or AC LED arrays. Likewise the AC COB may contain at least one string of LEDs or LED arrays. Removable brackets containing springs or separate spring clips are attached to the opposite side of the dish for allowing the dimmable AC LED fixture to be installed into an existing down light can in a retrofit application. For new installations of the dimmable AC LED fixture mounted straight to a junction box, the removable brackets containing the springs or separate spring clips are not used. No external driver is used with a dimmable AC LED circuit board. Instead, an on-board controller or ASIC or other means to control the LEDs including transistors or MOSFET devices may be used to operate the LEDs directly. The elimination of an external LED driver removes added weight and cost, and provides for an overall lower profile LED light in general. Lastly, a separate diffusion lens made preferably out of plastic to maintain an overall lower weight to the dimmable AC LED fixture is attached to the main metal dish on the same side as the dimmable AC LED light engine to protect the dimmable AC LEDs from dust and damage and also to diffuse the light that is emitted out the front of the dimmable AC LEDs mounted to a circuit board. 
       OBJECT OF THE INVENTION 
       [0015]    It is an object of the present invention to provide a dimmable device that will work in a retrofit and in a new installation application. 
         [0016]    It is another object of the present invention to provide a dimmable device that will fit into most existing down light can fixtures as a direct retrofit. 
         [0017]    It is yet another object of the present invention to provide a dimmable device that can be installed into a wide variety of different junction boxes for new installations. 
         [0018]    It is also another object of the present invention to provide a dimmable device that will provide a very lightweight LED light option for both retrofit and new installations. 
         [0019]    It is also yet another object of the present invention to provide a dimmable and thermally efficient LED light option for both retrofit and new installations. 
         [0020]    It is a final object of the invention to provide a dimmable device that will have a lower installed height profile for installation in tight overhead ceiling or wall installations. 
         [0021]    While the novel features of the invention are set forth particularly in the appended claims, the invention, both as to organization and content, will be better understood and appreciated along with other objects and features thereof, from the following detailed description taken in conjunction with the drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0022]      FIG. 1  shows the preferred embodiment of the present invention of a 4″ LED light in front, side, and isometric views showing the main metal plate, removable mounting bracket and springs, LED circuit board (not shown), optional external dimmable LED driver, and a diffusion lens. 
           [0023]      FIG. 2  shows the preferred embodiment of the present invention of a 4″ LED light in back, side, and isometric views showing the main metal plate, removable mounting bracket and springs, LED circuit board (not shown), optional external dimmable LED driver, and a diffusion lens. 
           [0024]      FIG. 3  shows an alternate embodiment of the present invention of a 4″ LED light in front, sides, and isometric views showing the main metal plate, removable mounting bracket and springs, dimmable AC LED circuit board (not shown), and a diffusion lens. 
           [0025]      FIG. 4  shows an alternate embodiment of the present invention of a 4″ LED light in back, sides, and isometric views showing the main metal plate, removable mounting bracket and springs, dimmable AC LED circuit board (not shown), and a diffusion lens. 
           [0026]      FIG. 5  shows a typical diffusion lens that can be used in both embodiments of the present inventions of a 4″ LED light as shown in  FIGS. 1, 2, 3, and 4 . 
           [0027]      FIG. 6  shows the preferred embodiment of the present invention of a 6″ LED light in front, side, and isometric views showing the main metal plate, removable mounting bracket and springs, LED circuit board (not shown), optional external dimmable LED driver, and a diffusion lens. 
           [0028]      FIG. 7  shows the preferred embodiment of the present invention of a 6″ LED light in back, side, and isometric views showing the main metal plate, removable mounting bracket and springs, LED circuit board (not shown), optional external dimmable LED driver, and a diffusion lens. 
           [0029]      FIG. 8  shows an alternate embodiment of the present invention of a 6″ LED light in front, sides, and isometric views showing the main metal plate, removable mounting bracket and springs, dimmable AC LED circuit board (not shown), and a diffusion lens. 
           [0030]      FIG. 9  shows an alternate embodiment of the present invention of a 6″ LED light in back, sides, and isometric views showing the main metal plate, removable mounting bracket and springs, dimmable AC LED circuit board (not shown), and a diffusion lens. 
           [0031]      FIG. 10  shows a typical diffusion lens that can be used in both embodiments of the present inventions of a 6″ LED light as shown in  FIGS. 6, 7, 8, and 9 . 
           [0032]      FIG. 11  shows an engineering testing record of the thermals done on the LEDs of a circuit board installed in a 4″ LED light of the preferred embodiment of the present invention as shown in  FIGS. 1 and 2 . 
           [0033]      FIG. 12  shows an engineering testing record of the thermals done on the LEDs of a circuit board installed in a 6″ LED light of the preferred embodiment of the present invention as shown in  FIGS. 6 and 7 . 
       
    
    
       [0034]    The foregoing has outlined rather broadly, the features and technical advantages of the present invention, so that those skilled in the art may better understand the detailed description of the invention that follows. Additional features and advantages of the invention will be described hereinafter that form the subject of the claims of the invention. Those skilled in the art will appreciate that they may readily use the conception and the specific embodiment disclosed as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. Those skilled in the art will also realize that such equivalent constructions do not depart from the spirit and scope of the invention in its broadest form. 
       DETAILED DESCRIPTION 
       [0035]    Although the present invention has been described in terms of the presently preferred embodiments, it is to be understood that such disclosure is not to be interpreted as limiting. Various alterations and modifications will no doubt become apparent to those skilled in the art after having read the above disclosure. Accordingly, it is intended that the appended claims be interpreted as covering all alterations and modifications as fall within the true spirit and scope of the invention. 
         [0036]      FIG. 1  shows the preferred embodiment of the present invention of a 4″ LED light  10  in front, side, and isometric views. LED light  10  consists of a main metal dish  15  with four mounting clips  20  center around the periphery of metal dish  15 . Clips  20  are preferably made of steel spring material and fastened to metal dish  15 . An LED circuit board or COB  25  (not shown) is attached to the opposite side of metal dish  15 . Power wires from LED circuit board or COB  25  (not shown) are fed through a clearance passage hole  30  to the back of metal dish  15  for direct connection to an external LED driver  35 . Mounting screw clearance holes  40  are provided on metal dish  15  for attaching LED light  10  to a standard junction box (not shown). Lastly, diffusion lens  45  (not shown) is attached to the front of metal dish  15  to cover and protect LED circuit board or COB  25  (not shown) from dust and damage and provides the proper optics to project an even and diffused light from LED light  10 . 
         [0037]      FIG. 2  shows the preferred embodiment of the present invention of a 4″ LED light  10  in back, side, and isometric views. LED light  10  consists of a main metal dish  15  with four mounting clips  20  centered on the periphery of metal dish  15 . Clips  20  are preferably made of steel spring material and fastened to metal dish  15 . An LED circuit board or COB  25  (not shown) is attached to the opposite side of metal dish  15 . Power wires from LED circuit board or COB  25  (not shown) are fed through a clearance passage hole  30  to the back of metal dish  15  for direct connection to an external LED driver  35 . Mounting screw clearance holes  40  are provided on metal dish  15  for attaching LED light  10  to a standard junction box (not shown). Lastly, diffusion lens  45  is attached to the front of metal dish  15  to cover and protect LED circuit board or COB  25  (not shown) from dust and damage and provides the proper optics to project an even and diffused light from LED light  10 . 
         [0038]      FIG. 3  shows an alternate embodiment of the present invention of a 4″ LED light  50  in front, side, and isometric views. LED light  50  consists of a main metal dish  55  with four mounting clips  60  centered on the periphery of metal dish  55 . Clips  60  are preferably made of steel spring material and fastened to metal dish  55 . A dimmable AC LED circuit board or AC COB  65  (not shown) is attached to the opposite side of metal dish  55 . Power wires from dimmable AC LED circuit board or AC COB  65  (not shown) are fed through a clearance passage hole  70  to the back of metal dish  55  for direct connection to AC power (not shown). Mounting screw clearance holes  75  are provided on metal dish  55  for attaching LED light  50  to a standard junction box (not shown). Lastly, diffusion lens  80  (not shown) is attached to the front of metal dish  55  to cover and protect dimmable AC LED circuit board or AC COB  65  (not shown) from dust and damage, and provides the proper optics to project an even and diffused light from LED light  50 . 
         [0039]      FIG. 4  shows an alternate embodiment of the present invention of a 4″ LED light  50  in back, side, and isometric views LED light  50  consists of a main metal dish  55  with four mounting clips  60  center around the periphery of metal dish  55 . Clips  60  are preferably made of steel spring material and fastened to metal dish  55 . A dimmable AC LED circuit board or AC COB  65  (not shown) is attached to the opposite side of metal dish  25 . Power wires from dimmable AC LED circuit board or AC COB  65  (not shown) are fed through a clearance passage hole  70  to the back of metal dish  55  for direct connection to AC power (not shown). Mounting screw clearance holes  75  are provided on metal dish  55  for attaching LED light  50  to a standard junction box (not shown). Lastly, diffusion lens  80  is attached to the front of metal dish  55  to cover and protect dimmable AC LED circuit board or AC COB  65  (not shown) from dust and damage, and provides the proper optics to project an even and diffused light from LED light  50 . 
         [0040]      FIG. 5  shows a typical diffusion lens  45 ,  80  that can be used in both preferred and alternate embodiments of the present inventions of a 4″ LED light  10 ,  50  as shown in  FIGS. 1, 2, 3, and 4 . Diffusion lens  45 ,  80  is shown with a front convex side  85  and a back concave side  90 . Back concave side  90  faces the LEDs (not shown) and protects them. Diffusion lens  45 ,  80  is preferably made out of a plastic material to be lightweight and will diffuse the light beam projected out by the LEDs (not shown) from front convex side  85 . There is also provided on diffusion lens  45 ,  80  mounting tabs  95  for secure and tool free attachment of the diffusion lens  45 ,  80  to LED light  10 ,  50 . It should be noted that someone skilled in the arts can use other means for attaching the diffusion lens  45 ,  80  to the LED light  10 ,  50  besides incorporating mounting tabs  95  including, but not limited to glue, adhesive, friction lock, screw and thread, tape, press fit, etc. 
         [0041]      FIG. 6  shows the preferred embodiment of the present invention of a 6″ LED light  100  in front, side, and isometric views. LED light  100  consists of a main metal dish  105  with two sets of mounting brackets  110  and springs  115  each centered on the periphery of metal dish  105 . Mounting brackets  110  are made of metal and springs  115  are preferably made of spring steel attached to mounting brackets  110  and all fastened to metal dish  105 . An LED circuit board or COB  120  (not shown) is attached to the opposite side of metal dish  105 . Power wires from LED circuit board or COB  120  (not shown) are fed through a clearance passage hole (not shown) to the back of metal dish  105  for direct connection to an external dimmable LED driver  125 . Mounting screw clearance holes  130  are provided on metal dish  105  for attaching LED light  100  to a standard junction box (not shown). Lastly, diffusion lens  135  is attached to the front of metal dish  105  to cover and protect LED circuit board or COB  120  (not shown) from dust and damage, and provides the proper optics to project an even and diffused light from LED light  100 . 
         [0042]      FIG. 7  shows the preferred embodiment of the present invention of a 6″ LED light  100  in back, side, and isometric views. LED light  100  consists of a main metal dish  105  with two sets of mounting brackets  110  and springs  115  each centered on the periphery of metal dish  105 . Mounting brackets  110  are made of metal and springs  115  are preferably made of spring steel attached to mounting brackets  110  and all fastened to metal dish  105 . An LED circuit board or COB  120  (not shown) is attached to the opposite side of metal dish  105 . Power wires from LED circuit board or COB  120  (not shown) are fed through a clearance passage hole (not shown) to the back of metal dish  105  for direct connection to an external dimmable LED driver  125 . Mounting screw clearance holes  130  are provided on metal dish  105  for attaching LED light  100  to a standard junction box (not shown). Lastly, diffusion lens  135  is attached to the front of metal dish  105  to cover and protect LED circuit board or COB  120  (not shown) from dust and damage, and provides the proper optics to project an even and diffused light from LED light  100 . 
         [0043]      FIG. 8  shows an alternate embodiment of the present invention of a 6″ LED light  140  in front, side, and isometric views. LED light  140  consists of a main metal dish  145  with two sets of mounting brackets  150  and springs  155  each centered on the periphery of metal dish  145 . Mounting brackets  150  are made of metal and springs  155  are preferably made of spring steel attached to mounting brackets  150  and all fastened to metal dish  145 . A dimmable AC LED circuit board or AC COB  160  (not shown) is attached to the opposite side of metal dish  145 . Power wires from dimmable AC LED circuit board or AC COB  160  (not shown) are fed through a clearance passage hole (not shown) to the back of metal dish  145  for direct connection to AC power (not shown). Mounting screw clearance holes  165  are provided on metal dish  145  for attaching LED light  140  to a standard junction box (not shown). Lastly, diffusion lens  170  is attached to the front of metal dish  145  to cover and protect dimmable AC LED circuit board or AC COB  160  (not shown) from dust and damage, and provides the proper optics to project an even and diffused light from LED light  140 . 
         [0044]      FIG. 9  shows an alternate embodiment of the present invention of a 6″ LED light  140  in back, side, and isometric views. LED light  140  consists of a main metal dish  145  with two sets of mounting brackets  150  and springs  155  each centered on the periphery of metal dish  145 . Mounting brackets  150  are made of metal and springs  155  are preferably made of spring steel attached to mounting brackets  150  and all fastened to metal dish  145 . A dimmable AC LED circuit board or AC COB  160  (not shown) is attached to the opposite side of metal dish  145 . Power wires from dimmable AC LED circuit board or AC COB  160  (not shown) are fed through a clearance passage hole (not shown) to the back of metal dish  145  for direct connection to AC power (not shown). Mounting screw clearance holes  165  are provided on metal dish  145  for attaching LED light  140  to a standard junction box (not shown). Lastly, diffusion lens  170  is attached to the front of metal dish  145  to cover and protect dimmable AC LED circuit board or AC COB  160  (not shown) from dust and damage, and provides the proper optics to project an even and diffused light from LED light  140 . 
         [0045]      FIG. 10  shows a typical diffusion lens  135 ,  170  that can be used in both preferred and alternate embodiments of the present inventions of a 6″ LED light  100 ,  140  as shown in  FIGS. 6, 7, 8, and 9 . Diffusion lens  135 ,  170  is shown with a front convex side  175  and a back concave side  180 . Back concave side  180  faces the LEDs (not shown) and protects them. Diffusion lens  135 ,  170  is preferably made out of a plastic material to be lightweight and will diffuse the light beam projected out by the LEDs (not shown) from front convex side  175 . There is also provided on diffusion lens  135 ,  170  mounting tabs  185  for secure and tool free attachment of the diffusion lens  135 ,  170  to LED light  100 ,  140 . It should be noted that someone skilled in the arts can use other means for attaching the diffusion lens  135 ,  170  to the LED light  100 ,  140  besides incorporating mounting tabs  185  including, but not limited to glue, adhesive, friction lock, screw and thread, tape, press fit, etc. 
         [0046]      FIG. 11  shows an engineering testing record of the thermals done on the LED circuit board installed in a 4″ LED light  10 ,  50  of the preferred embodiment of the present invention as shown in  FIGS. 1 and 2 . The LEDs used in the test are 5630 mid-power LEDs from Seoul Semiconductor with an operational temperature rating of 70.0 deg. C. Note that any industry 5630 or similar LED package can be used and should produce similar results. From the test data, one can see that the maximum temperature measured at the LED was 64.7 degrees Celsius at an ambient temperature of 23.7 degrees C. Normalized to 25.0 deg. C., the maximum LED temperature for the 4″ LED light  10 ,  50  is 66.0 deg. C., which is below the 70.0 deg. C. rated operating temperature of the Seoul Semiconductor 5630 mid-power LEDs. 
         [0047]      FIG. 12  shows an engineering testing record of the thermals done on the LED circuit board installed in a 6″ LED light  100 ,  140  of the preferred embodiment of the present invention as shown in  FIGS. 6 and 7 . The LEDs used in the test are 5630 mid-power LEDs from Seoul Semiconductor with an operational temperature rating of 70.0 deg. C. Note that any industry 5630 or similar LED package can be used and should produce similar results. From the test data, one can see that the maximum temperature measured at the LED was 66.4 degrees Celsius at an ambient temperature of 23.8 degrees C. Normalized to 25.0 deg. C., the maximum LED temperature for the 6″ LED light  100 ,  140  is 67.6 deg. C., which is below the 70.0 deg. C. rated operating temperature of the Seoul Semiconductor 5630 mid-power LEDs. 
         [0048]    It will be understood that various changes in the details, materials, types, values, and arrangements of the components that have been described and illustrated in order to explain the nature of this invention may be made by those skilled in the art without departing from the principle and scope of the invention as expressed in the following claims.