Patent Publication Number: US-2006012999-A1

Title: Molded-in light emitting diode light source

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
      This application claims priority from Provisional Patent Application No. 60/588,869, filed Jul. 16, 2004. 
    
    
     TECHNICAL FIELD  
      This invention relates to electric lamps and particularly to electric lamps utilizing a single light emitting diode (hereafter LED or LEDs) light source. More particularly the invention is concerned with an electric lamp with an LED light source coupled to a heat sink with rapid mounting features.  
     BACKGROUND ART  
      In the past, most automotive light sources have involved the use of incandescent bulbs. While working well and being inexpensive, these bulbs have a relatively short life and, of course, the thin filament employed was always subject to breakage due to vibration.  
      Recently some of the automotive uses, particularly the stoplight, have been replaced by LEDs. These solid-state light sources have incredible life times, in the area of 100,000 hours, and are not as subject to vibration failures. However, these LED sources have been hard-wired into their appropriate location, which increases the cost of installation. Additionally, the light sources have employed multiple LEDs, which increased the cost. It would therefore be an advance in the art if an LED light source could be provided that had the ease of installation of the incandescent light sources. Alternatively, it would be advantageous to have a light source that could be permanently mounted without the need for any specific orientation.  
     DISCLOSURE OF INVENTION  
      It is, therefore, an object of the invention to obviate the disadvantages of the prior art.  
      It is another object of the invention to enhance lighting operations.  
      These objects are accomplished, in one aspect of the invention, by a lamp assembly comprising: a base having an axially extending post with a first surface, said base being thermally conductive; a single light emitting diode operatively affixed to said first surface; a reflector in optical communication with said light emitting diode, said reflector being mechanically fixed to said thermally conductive base; and electrical connections extending through said base to said light emitting diode.  
      Excellent heat dissipation is provided by the direct attachment of the light emitting diode to a thermally conductive post that is an integral part of the heat-sinking base. Further, by forming the base and the reflector as a single unit, the number of parts, and thereby the necessary assembling operations, is reduced, lessening the cost of the lamp. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a diagrammatic view of an embodiment of the invention; and  
       FIG. 2  is a similar view of an alternate embodiment of the invention. 
    
    
     BEST MODE FOR CARRYING OUT THE INVENTION  
      For a better understanding of the present invention, together with other and further objects, advantages and capabilities thereof, reference is made to the following disclosure and appended claims taken in conjunction with the above-described drawings.  
      Referring now to the drawing with greater particularity, there is shown in the figure lamp assembly  10  that comprises a base  12  having an axially extending post  14  with a first surface  16  on the distal end of the post  14 . The base and integral post are thermally conductive and are preferably constructed of copper or aluminum.  
      A thermally conductive but electrically insulating member  19  can be affixed to the first surface  16  of the post  14  and a single light emitting diode  18  can be operatively affixed to the insulating member  19 , for example by a thermally conductive cement. For optimal effect the light emitting diode is side-emitting one that is axially centered on the post  14 . A reflector  20  is in optical communication with the light emitting diode  18 , the reflector  20  being mechanically fixed to the base  12 . In a preferred embodiment of the invention the mechanical fixation comprises the reflector  20  and the base  12  being insert-molded together. With insert molding a superb watertight seal is provided along with the more than adequate mechanical strength provided. Alternatively, the mechanical fixation can comprise the base  12  and the reflector  20  being compression-fitted together. The latter approach allows the reflector to be installed in a desired location and the light emitting diode to be inserted at a later time.  
      The post  14  can be solid, with passages provide for the LED connections  22 ,  24 , as shown in  FIG. 1 , or it can be tubular such as post  14   a,  as shown in  FIG. 2 . In the latter embodiment the first surface  16  can be on a plug  16   a  fitted into the distal end of the cylindrical post  14   a.    
      Still another alternative allows the post  16  and the base  12  to be glued into the appropriate opening in the reflector. In any case, the electrical connections  22 ,  24  extend through the base  12 , for example, by being insulatingly threaded through the post  14 , to the light emitting diode.  
      The electrical connections  22 ,  24  emanate from a housing  26  that is attached to the base  12 . The housing  26  contains the necessary circuitry  28 , which can be mounted on a printed circuit board  29 , and a suitable connector  31  for attachment to a power source. Of course, the circuitry can be contained in other locations, as necessitated or desired by the end use of the lamp assembly.  
      At least one surface  30  of the base  12  is exposed to air along the exterior of the assembly  10  for heat dissipation.  
      In a preferred embodiment of the invention, the light emitting diode  18  is substantially a side emitting diode that is axially centered on the post  14  for maximum optical convenience. Such diodes are available on the open market.  
      Thus there is provided a new lamp assembly that is convenient to employ to supply various forms of automotive lighting, such as taillights, stoplights or turn signals. The assembly is virtually vibration-free and can be mounted in many ways, providing great flexibility.  
      While there have been shown and described what are present considered to be the preferred embodiments of the invention, it will be apparent to those skilled in the art that various changes and modifications can be made herein without departing from the scope of the invention as defined by the appended claims.