Abstract:
The present invention provides a lighting assembly that incorporates a high intensity LED package into an integral housing for further incorporation into other useful lighting devices. The present invention primarily includes three housing components, namely an inner mounting die, an outer enclosure and an outer housing that cooperate to enhance the heat management of the overall assembly. The inner and outer components cooperate to retain the LED package, provide electrical and control connections, provide integral heat sink capacity and includes an integrated reflector cup. Surface area enhancements on the outer surface of the outer enclosure are aligned with openings in the outer housing to allow efficient air flow around the LED assembly to enhance cooling. In this manner, high intensity LED packages can be incorporated into lighting assemblies with reduced risk of overheating and malfunction.

Description:
CROSS PREFERENCE TO RELATED APPLICATIONS 
   This application is related to and claims priority from earlier tired provisional patent application No. 60/338,893, filed Dec. 10, 2001 and is a continuation-in-part of U.S. patent application Ser. No. 10/796,360, filed Mar. 9, 2004, which is a continuation-in-part of U.S. patent application Ser. No. 10/659,575, filed Sep. 10, 2003, which is a continuation-in-part of U.S. patent application Ser. No. 10/315,336, filed Dec. 10, 2002 now U.S. Pat. No. 6,827,468. 

   BACKGROUND OF THE INVENTION 
   The present invention relates to a new assembly for packaging a high intensity LED lamp for further incorporation into a lighting assembly. More specifically, this invention relates to an assembly for housing a high intensity LED lamp that provides integral electrical connectivity, integral heat dissipation and an integral reflector device in a compact and integrated package for further incorporation into a lighting device and more specifically for use in a flashlight. 
   Currently, several manufacturers are producing high brightness light emitting diode (LED) packages in a variety of forms. These high brightness packages differ from conventional LED lamps in that they use emitter chips of much greater size, which accordingly have much higher power consumption requirements. In general, these packages were originally produced for use as direct substitutes for standard LED lamps. However, due to their unique shape, size and power consumption requirements they present manufacturing difficulties that were originally unanticipated by the LED manufacturers. One example of a high brightness LED of this type is the Luxeon™ Emitter Assembly LED (Luxeon is a trademark of Lumileds Lighting, LLC). The Luxeon LED uses an emitter chip that is four times greater in size than the emitter chip used in standard LED lamps. While this LED has the desirable characteristic of producing a much greater light output than the standard LED, it also generates a great deal more heat than the standard LED. If this heat is not effectively dissipated, it may cause damage to the emitter chip and the circuitry required to drive the LED. 
   Often, to overcome the buildup of heat within the LED, a manufacturer will incorporate a heat dissipation pathway within the LED package itself. The Luxeon LED, for example, incorporates a metallic contact pad into the back of the LED package to transfer the heat out through the back of the LED. In practice, it is desirable that this contact pad in the LED package be placed into contact with further heat dissipation surfaces to effectively cool the LED package. In the prior art attempts to incorporate these packages into further assemblies, the manufacturers that used the Luxeon LED have attempted to incorporate them onto circuit boards that include heat transfer plates adjacent to the LED mounting location to maintain the cooling transfer pathway from the LED. While these assemblies are effective in properly cooling the LED package, they are generally bulky and difficult to incorporate into miniature flashlight devices. Further, since the circuit boards that have these heat transfer plates include a great deal of heat sink material, making effective solder connections to the boards is difficult without applying a large amount of heat. The Luxeon LED has also been directly mounted into plastic flashlights with no additional heat sinking. Ultimately however, these assemblies malfunction due to overheating of the emitter chip, since the heat generated cannot be dissipated. 
   There is therefore a need for an assembly that provides for the mounting of a high intensity LED package that includes a great deal of heat transfer potential in addition to providing a means for further incorporating the LED into the circuitry of an overall lighting assembly. 
   BRIEF SUMMARY OF THE INVENTION 
   In this regard, the present invention provides an assembly that incorporates a high intensity LED package, such as the Luxeon Emitter Assembly described above, into an integral housing for further incorporation into other useful lighting devices. The present invention can be incorporated into a variety of lighting assemblies including but not limited to flashlights, specialty architectural grade lighting fixtures and vehicle lighting. The present invention primarily includes two housing components, namely an inner mounting die, and an outer enclosure. The inner mounting die is formed from a highly thermally conductive material. While the preferred material is brass, other materials such as thermally conductive polymers or other metals may be used to achieve the same result. The inner mounting die is cylindrically shaped and has a recess in the top end. The recess is formed to frictionally receive the mounting base of a high intensity LED assembly. A longitudinal groove is cut into the side of the inner mounting die that may receive an insulator strip or a strip of printed circuitry, including various control circuitry thereon. Therefore, the inner mounting die provides both electrical connectivity to one contact of the LED package and also serves as a heat sink for the LED. The contact pad at the back of the LED package is in direct thermal communication with the inner surface of the recess at the top of the inner mounting die thus providing a highly conductive thermal path for dissipating the heat away from the LED package. 
   The outer enclosure of the present invention is preferably formed from the same material as the inner mounting die. In the preferred embodiment, this is brass but may be thermally conductive polymer or other metallic materials. The outer enclosure slides over the inner mounting die and has a circular opening in the top end that receives the clear optical portion of the Luxeon LED package therethrough. The outer enclosure serves to further transfer heat from the inner mounting die and the LED package, as it is also highly thermally conductive and in thermal communication with both the inner mounting die and the LED package. The outer enclosure also covers the groove in the side of the inner mounting die protecting the insulator strip and circuitry mounted thereon from damage. 
   Another feature of the outer enclosure of the present invention is that the end that receives the optical portion of the LED package also serves as a reflector for collecting the light output from the LED package and further focusing and directing it into a collimated beam of light. After assembly, it can be seen that the present invention provides a self contained packaging system for the Luxeon Emitter Assembly or any other similar packaged high intensity LED device. Assembled in this manner, the present invention can be incorporated into any type of lighting device. 
   In particular, the assembled package is then placed into a flashlight housing. The flashlight housing of the present invention is further modified in accordance with the present disclosure to further enhance the heat management of the overall flashlight assembly in that the housing has vent openings in the side wall thereof. The vent openings are provided in the side wall at locations adjacent the outer enclosure of the package. In this manner, improved air circulation and heat dissipation is provided by facilitating the circulation of free air around the heat dissipating surfaces of the outer enclosure. 
   Accordingly, one of the objects of the present invention is the provision of an assembly for packaging a high intensity LED. Another object of the present invention is the provision of an assembly for packaging a high intensity LED that includes integral heat sink capacity. A further object of the present invention is the provision of an assembly for packaging a high intensity LED that includes integral heat sink capacity while further providing means for integral electrical connectivity and control circuitry. Yet a further object of the present invention is the provision of an assembly for packaging a high intensity LED that includes integral heat sink capacity, a means for electrically connectivity and an integral reflector cup that can creates a completed flashlight head for further incorporation into a flashlight housing or other lighting assembly. 
   Other objects, features and advantages of the invention shall become apparent as the description thereof proceeds when considered in connection with the accompanying illustrative drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the drawings which illustrate the best mode presently contemplated for carrying out the present invention: 
       FIG. 1  is a perspective view of the LED lighting assembly of the present invention; 
       FIG. 2  is a front view thereof; 
       FIG. 3  is rear view thereof; 
       FIG. 4  is an exploded perspective thereof; 
       FIG. 5  is a cross-sectional view thereof as taken along line  5 — 5  of  FIG. 1 ; 
       FIG. 6  is a schematic diagram generally illustrating the operational circuitry of present invention as incorporated into a complete lighting assembly. 
       FIG. 7  is an exploded perspective view of a first alternate embodiment of the present invention; 
       FIG. 8  is a cross-sectional view thereof as taken along line  8 — 8  of  FIG. 7 ; 
       FIG. 9  is an exploded perspective view of a second alternate embodiment of the present invention; 
       FIG. 10  is a cross-sectional view thereof as taken along line  10 — 10  of  FIG. 9 ; 
       FIG. 11  is an exploded perspective view of a third alternate embodiment of the present invention; 
       FIG. 12  is a cross-sectional view thereof as taken along line  12 — 12  of  FIG. 11 ; 
       FIG. 13  is an exploded perspective view of a fourth alternate embodiment of the present invention; 
       FIG. 14  is a cross-sectional view thereof as taken along line  14 — 14  of  FIG. 13 ; 
       FIG. 15  is a perspective view of the LED lighting assembly installed into the ventilated housing of the present invention; 
       FIG. 16  is a cross-sectional view thereof as taken along line  16 — 16  of  FIG. 15 ; 
       FIG. 17  is a perspective view of the LED head assembly removed from the ventilated housing of the present invention; and 
       FIG. 18  is a cross-sectional view thereof as taken along line  18 — 18  of  FIG. 17 . 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Referring now to the drawings, the light emitting diode (LED) lighting assembly of the present invention is illustrated and generally indicated at  10  in  FIGS. 1–5 . Further, a schematic diagram is shown in  FIG. 6  generally illustrating the present invention incorporated into a flashlight circuit. As will hereinafter be more fully described, the present invention illustrates an LED lighting assembly  10  for further incorporation into a lighting device. For the purposes of providing a preferred embodiment of the present invention, the device  10  will be shown incorporated into a flashlight, however, the present invention also may be incorporated into any other lighting device such as architectural specialty lighting or vehicle lighting. In general, the present invention provides a means for packaging a high intensity LED lamp that includes integral heat sink capacity, electrical connectivity and an optical assembly for controlling the light output from the LED. The present invention therefore provides a convenient and economical assembly  10  for incorporating a high intensity LED into a lighting assembly that has not been previously available in the prior art. 
   Turning to  FIGS. 1 ,  2  and  3 , the LED package assembly  10  can be seen in a fully assembled state. The three main components can be seen to include a high intensity LED lamp  12 , an inner mounting die  14  and an outer enclosure  16 . In  FIGS. 1 and 2 , the lens  18  of the LED  12  can be seen extending through an opening in the front wall of the outer enclosure  16 . Further, in  FIG. 3  a rear view of the assembled package  10  of the present invention can be seen with a flexible contact strip shown extending over the bottom of the interior die  14 . 
   Turning now to  FIGS. 4 and 5 , an exploded perspective view and a cross sectional view of the assembly  10  of the present invention can be seen. The assembly  10  of the present invention is specifically configured to incorporate a high intensity LED lamp  12  into a package that can be then used in a lighting assembly. The high intensity LED lamp  12  is shown here as a Luxeon Emitter assembly. However, it should be understood that the mounting arrangement described is equally applicable to other similarly packaged high intensity LED&#39;s. The LED  12  has a mounting base  20  and a clear optical lens  18  that encloses the LED  12  emitter chip (not shown). The LED  12  also includes two contact leads  22 ,  24  that extend from the sides of the mounting base  20 , to which power is connected to energize the emitter chip. Further, the LED lamp  12  includes a heat transfer plate  26  positioned on the back of the mounting base  20 . Since the emitter chip in this type of high intensity LED lamp  12  is four times the area of a standard emitter chip, a great deal more energy is consumed and a great deal more heat is generated. The heat transfer plate  26  is provided to transfer waste heat out of the LED lamp  12  to prevent malfunction or destruction of the chip. In this regard, the manufacturer has provided the heat transfer plate  26  for the specific purpose of engagement with a heat sink. However, all of the recommended heat sink configurations are directed to a planar circuit board mount with a heat spreader or a conventional finned heat sink. Neither of these arrangements is suitable for small package integration or a typical tubular flashlight construction. 
   In contrast, the mounting die  14  used in the present invention is configured to receive the LED lamp  12  and further provide both electrical and thermal conductivity to and from the LED lamp  12 . The mounting die  14  is fashioned from a thermally conductive and electrically conductive material. In the preferred embodiment the mounting die  14  is fashioned from brass, however, the die  14  could also be fabricated from other metals such as aluminum or stainless steel or from an electrically conductive and thermally conductive polymer composition and still fall within the scope of this disclosure. The mounting die  14  has a recess  28  in one end thereof that is configured to frictionally receive and retain the base  20  of the LED lamp  12 . While the base  20  and the recess  28  are illustrated as circular, it is to be understood that this recess is intended to receive the housing base regardless of the shape. As can be seen, one of the contact leads  22  extending from the base  20  of the LED lamp  12  must be bent against the LED lamp  12  base  20  and is thus trapped between the base  20  and the sidewall of the recess  28  when the LED lamp  12  is installed into the recess  28 . When installed with the first contact lead  22  of the LED  12  retained in this manner, the lead  22  is in firm electrical communication with the mounting die  14 . A channel  30  extends along one side of the mounting die  14  from the recess to the rear of the die  14 . When the LED lamp  12  is installed in the mounting die  14 , the second contact lead  24  extends into the opening in the channel  30  out of contact with the body of the mounting die  14 . The heat transfer plate  26  provided in the rear of the LED lamp  12  base  20  is also in contact with the bottom wall of the recess  28  in the mounting die  14 . When the heat transfer plate  26  is in contact with the die  14 , the heat transfer plate  26  is also in thermal communication with the die  14  and heat is quickly transferred out of the LED lamp  12  and into the body of the die  14 . The die  14  thus provides a great deal of added heat sink capacity to the LED lamp  12 . 
   An insulator strip  32  is placed into the bottom of the channel  30  that extends along the side of the mounting die  14 . The insulator strip  30  allows a conductor to be connected to the second contact lead  24  of the LED lamp  12  and extended through the channel  30  to the rear of the assembly  10  without coming into electrical contact with and short circuiting against the body of the die  14 . In the preferred embodiment, the insulator strip  32  is a flexible printed circuit strip with circuit traces  34  printed on one side thereof. The second contact lead  24  of the LED lamp  12  is soldered to a contact pad  36  that is connected to a circuit trace  34  at one end of the insulator strip  32 . The circuit trace  34  then extends the length of the assembly and terminated in a second contact pad  38  that is centrally located at the rear of the assembly  10 . Further, control circuitry  40  may be mounted onto the flexible circuit strip  32  and housed within the channel  30  in the die  14 . The control circuitry  40  includes an LED driver circuit as is well known in the art. 
   With the LED lamp  12  and insulator strip  32  installed on the mounting die  14 , the mounting die  14  is inserted into the outer enclosure  16 . The outer enclosure  16  is also fashioned from a thermally conductive and electrically conductive material. In the preferred embodiment the outer enclosure  16  is fashioned from brass, however, the outer enclosure  16  could also be fabricated from other metals such as aluminum or stainless steel or from an electrically conductive and thermally conductive polymer composition and still fall within the scope of this disclosure. The outer enclosure  16  has a cavity that closely matches the outer diameter of the mounting die  14 . When the mounting die  14  is received therein, the die  14  and the housing  16  are in thermal and electrical communication with one another, providing a heat transfer pathway to the exterior of the assembly  10 . As can also be seen, electrical connections to the assembly  10  can be made by providing connections to the outer enclosure  16  and the contact pad  38  on the circuit trace  34  at the rear of the mounting die  14 . The outer enclosure  16  includes an aperture  42  in the front wall thereof through which the optical lens portion  18  of the LED lamp  12  extends. The aperture  42  is fashioned to provide optical control of the light emitted from the LED lamp  12 . The aperture  42  in the preferred embodiment is shaped as a reflector cone and may be a simple conical reflector or a parabolic reflector. The walls of the aperture  42  may also be coated with an anti-reflective coating such as black paint or anodized to prevent the reflection of light, allowing only the image of the LED lamp  12  to be utilized in the finished lighting assembly. 
   Finally, an insulator disk  44  is shown pressed into place in the open end of the outer enclosure  16  behind the mounting die  14 . The insulator disk  44  fits tightly into the opening in the outer enclosure  16  and serves to retain the mounting die  14  in place and to further isolate the contact pad  38  at the rear of the mounting die  14  from the outer enclosure  16 . 
   Turning now to  FIG. 6 , a schematic diagram of a completed circuit showing the LED assembly  10  of the present invention incorporated into functional lighting device is provided. The LED assembly  10  is shown with electrical connections made thereto. A housing  46  is provided and shown in dashed lines. A power source  48  such as a battery is shown within the housing  46  with one terminal in electrical communication with the outer enclosure  15  of the LED assembly  10  and a second terminal in electrical communication with the circuit trace  38  at the rear of the housing  16  via a switch assembly  50 . The switching assembly  50  is provided as a means of selectively energizing the circuit and may be any switching means already known in the art. The housing  46  of the lighting device may also be thermally and electrically conductive to provide additional heat sink capacity and facilitate electrical connection to the outer enclosure  16  of the LED assembly  10 . 
   Turning to  FIGS. 7 and 8 , an alternate embodiment of the LED assembly  100  is shown the outer enclosure is a reflector cup  102  with an opening  104  in the center thereof. The luminescent portion  18  of the LED  12  is received in the opening  104 . The reflector cup  102  includes a channel  106  that is cleared in the rear thereof to receive the mounting base  20  of the LED  12  wherein the rear surface of the mounting base  20  is substantially flush with the rear surface  108  of the reflector cup  102  when the LED in  12  is in the installed position. The mounting die is replaced by a heat spreader plate  110 . The spreader plate  110  is in thermal communication with both the heat transfer plate on the back of the LED  12  and the rear surface  108  of the reflector cup  102 . In this manner when the LED  12  is in operation the waste heat is conducted from the LED  12  through the spreader plate  110  and into the body of the reflector cup  102  for further conduction and dissipation. The spreader plate  110  may be retained in its operative position by screws  112  that thread into the back  108  of the reflector cup  102 . Alternatively, a thermally conductive adhesive (not shown) may be used to hold the LED  12 , the reflector cup  102  and the spreader plate  110  all in operative relation. 
     FIGS. 7 and 8  also show the installation of a circuit board  114  installed behind the spreader plate  110 . The circuit board  114  is electrically isolated from the spreader plate  110  but has contact pads thereon where the electrical contacts  22  of the LED  12  can be connected. Further a spring  116  may be provided that extends to a plunger  118  that provides an means for bringing power from one battery contact into the circuit board  114 . Power from the second contact of the power source may be conducted through the outer housing  120  and directed back to the circuit board. While specific structure is shown to complete the circuit path, it can be appreciated that the present invention is primarily directed to the assembly including merely the reflector cup  102 , the LED  12  and the spreader plate  110 . 
   Turning now to  FIGS. 9 and 10 , a second alternate embodiment is shown where the slot is replaced with a circular hole  202  that receives a Luxeon type LED  12  emitter. Further, a lens  204  is shown for purposes of illustration. In all other respects this particular embodiment is operationally the same as the one described above. It should be note that relief areas  206  are provided in the spreader plate  208  that are configured to correspond to the electrical leads  22  of the LED  12  being used in the assembly. In this manner, the contacts  22  can be connected to the circuit board  210  without contacting the spreader plate  208 . 
   Turning to  FIGS. 11 and 12 , a third alternate embodiment of the LED assembly  300  is shown. The reflector cup  302  includes both a circular hole  304  and a slot  206  in the rear thereof. The important aspect of the present invention is that the spreader plates  110 ,  210  or  308  are in flush thermal communication with both the rear surface of the LED  12  and the rear surface of the reflector cups  102 ,  200  and  302  to allow the heat to be transferred from the LED  12  to the reflector cup  102 ,  200  and  302 . 
   Turning to  FIGS. 13 and 14 , a fourth alternate embodiment of the LED assembly  400  is shown. The reflector cup  402  is configured to receive the entire LED  12  within the front of the reflector cup  402 . The important aspect of the present invention is that the reflector cup  402  is metallic and thermal and electrically conductive. The rear surface of the LED  12  and one contact  22  thereof are in contact rear wall  404  of the reflector cup  402 . In this manner, the reflector cup  402  provides both means for heat transfer from the LED  12  and electrical conductivity to one lead  22  of the LED  12 . The second lead  24  of the LED  12  extends through a hole  406  in the reflector cup  402  and is in electrical communication with the circuit board  408 . A battery contact  410  and spring  412  transfer electricity from one terminal of the power source to the rear of the circuit board  408  while power from the other terminal is introduced into the reflector cup  402  and to the front of the circuit board  408 . The entire subassembly is connected together using plastic retainers  414  and  416  and heat staked together to provide a completed assembly  400 . 
     FIGS. 15–18  illustrate another alternate embodiment of the LED assembly  500  with improved heat management of the present invention. This embodiment utilizes any one of the foregoing packaged head assemblies and incorporates the head assembly  500  into a novel housing  502  for use in a finished device such as a flashlight. Similarly, while  FIG. 15  illustrates a flashlight it can be appreciated by one skilled in the art that a variety of housings  502  could be utilized to allow the assembly to be incorporated into any lighting environment. Further, the housing  502  may be thermally conductive and formed from a material such as aluminum or stainless steel. Further, by manufacturing the housing  502  and LED assembly  500  in accordance with the present disclosure, the housing  502  may be a nonconductive material such as a polymer. The important feature of the housing  502 , as can be best seen in  FIG. 15 , is the provision of vent openings  504  in the side walls of the housing  502 . The vent openings  504  in the side of the housing  502  are placed in a location so as to correspond to and align with the outer enclosure  506  of the LED assembly  500 . In this manner, the heat being dissipated by the outer enclosure  506  of the LED assembly  500  is exposed to free and circulating air. Specifically, air is allowed to flow freely into the flashlight housing  502  via the vent openings  504  provided therein to conduct waste heat away from the LED head assembly  500 . This feature allows for enhanced heat management and dissipation thereby providing a high intensity LED lighting assembly with increased performance and reliability. 
     FIG. 16  shows a cross-sectional view take through the flashlight of the present invention. As can be seen, the housing  502  is configured to receive a LED lighting assembly  500  into one end thereof. The opposite end of the housing  502  receives and encloses a power source  508  such as batteries and an end cap  510  that also includes the operable elements necessary to provide multi-function switching. As was stated above, while a flashlight is shown, the present invention can also be utilized in other environments that may include hard wired connections. In those cases the rear of the housing  502  would be modified to accommodate power connections to line voltage such as 120 volt residential supply voltage or the low voltage supply side of a transformer. 
   Turning now to  FIGS. 17 and 18 , the particularly novel features associated with the present invention are shown and illustrated. A fifth alternate embodiment of the LED assembly  500  is shown. As described above, a mounting die  512  is provided as the central element of the assembly. The mounting die  512  is both thermally and electrically conductive and includes a receiving end to which the high powered LED  514  is mounted with the heat transfer plate in contact with the mounting die  512 . In this manner, heat is conducted directly from the LED  514  into the mounting die  512 . The exterior enclosure  506  is a thermally conductive material that includes an opening in the rear to receive the mounting die  512  with the LED  514  mounted thereon. The exterior enclosure  506  includes an opening in the opposite end thereof to allow the optical element  516  of the LED  514  to extend therethrough. Further, the exterior enclosure  506  is configured to surround the entire mounting die  512  providing a large contact surface area for heat transfer. The outer surface of the exterior enclosure  506  is further modified with surface area enhancements  518 . The surface area enhancements  518  are shown as substantially concentric disk shaped fins extending outwardly from the wall of the exterior enclosure  506 . While the surface area enhancements  518  are shown as disk shaped fins, clearly they also could be spiral, longitudinal or oblique fins. Further the surface area enhancements  518  could also be pins or ribs and still fall within the present disclosure. The surface area enhancements  518  are placed on the outer wall of the exterior enclosure  506  so as to correspond with the vent openings  504  in the side wall of the outer housing  502 . In this manner, cooling air is allowed to circulate in through the openings  504  in the side wall  502 , around the surface area enhancements  518  to collect waste and then back out through the vent openings  504 . In this manner the heat management properties of the present invention are greatly enhanced as compared to the flashlights of the prior art. It is the placement of the vent openings  504  in close proximity adjacent to the thermally conductive exterior enclosure  506  that allows free air flow and effective cooling of the LED assembly  500  that makes the present invention more effective that similar devices found in the prior art. 
   It can therefore be seen that the present invention  10  provides a compact package assembly for incorporating a high intensity LED  12  into a lighting device. The present invention provides integral heat sink capacity and electrical connections that overcome the drawbacks associated with prior art attempts to use LED&#39;s of this type while further creating a versatile assembly  10  that can be incorporated into a wide range of lighting devices. For these reasons, the instant invention is believed to represent a significant advancement in the art, which has substantial commercial merit. 
   While there is shown and described herein certain specific structure embodying the invention, it will be manifest to those skilled in the art that various modifications and rearrangements of the parts may be made without departing from the spirit and scope of the underlying inventive concept and that the same is not limited to the particular forms herein shown and described except insofar as indicated by the scope of the appended claims.