Patent Publication Number: US-2006013004-A1

Title: LED sideward emitting lamp

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
      This application claims priority from Provisional Patent Application Serial No. 60/588,143, filed Jul. 16, 2004. 
    
    
     TECHNICAL FIELD  
      This invention relates to light sources and more particularly to light sources employing light emitting diodes (LED or LEDs) and more particularly to light sources useful in the automotive field such as for headlights, taillights, stoplights, fog lights, turn signals, etc.  
     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      Recently some of the uses have been replaced by LEDs.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. Particular examples of various proposals are shown in U.S. Pat. Nos. 6,641,287; 5,136,483; 6,474,852; 6,672,741; 6,238,073; 5,471,371; 6,840,652; and 6,585,402. While providing workable strategies, the lamps are complex and expensive to produce and require difficult LED mounting structures or alignment procedures. It would be an advance in the art if LED illumination could be expanded to other areas of automotive lighting, particularly if the emission of the light could be adequately controlled for specific purposes and if the mounting procedures were simple, relatively inexpensive, and easy to employ.  
     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 LED light sources.  
      It is another object of the invention to enhance LED and reflector combinations.  
      These objects are accomplished, in one aspect of the invention; by the provision of a lamp comprising a concave reflector arrayed about an axis and having a circumferential rim; and an LED light source mounted upon a support that is associated with said concave reflector, said support being arrayed along said circumferential rim and directing light toward said concave reflector.  
      In an alternative embodiment there is provided a lamp comprising a concave reflector arrayed about an axis and having a circumferential rim and an LED light source mounted upon a support that is associated with said concave reflector, said support having an end that is fixed in said concave reflector.  
      Such lamps provide relative simplicity in construction with ease of alignment. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a diagrammatic view of an embodiment of the invention;  
       FIG. 2  is a diagrammatic view of an alternate embodiment of the invention;  
       FIG. 3  is a diagrammatic view of yet another embodiment of the invention; and  
       FIG. 4  is a diagrammatic view of still another 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 drawings with greater particularity, there is shown in  FIG. 1 a  lamp  10  that comprises a concave reflector  12  arrayed about an axis  14  and having a circumferential rim  16 . An LED light source  18  is mounted upon a support  20  that is associated with the concave reflector  12 , the support  20  having a leg  22  that is fixed in the concave reflector  12 , for example by a press-fit of the leg  22  in a slot  22   a.  The LED light source  18  can be of any suitable style, such as a side emitting LED and the emitted color can be suitable for the lamp&#39;s purpose, for example, red emitting for a tail light or stop light or white for a headlight. More than one LED can be employed if desired. If only one LED is used it is preferably aligned along the axis  14 .  
      An alternate embodiment is shown in  FIG. 2  wherein the support  20  is U-shaped with a bight  24  and legs  22 ,  26 . The LED light source  18  is mounted in the bight  24  of the U-shaped support in a manner to direct light directly toward the concave reflector  12  and the legs  22 ,  26  of the U-shaped support are fixed in said concave reflector  12  in any suitable manner, for example by being press-fitted into slots  22   a  and  26   a.    
      In  FIG. 3  the lamp  10  similarly comprises a concave reflector  12  arrayed about an axis  14  and having a circumferential rim  16 . However, in this instance an LED light source  18  is mounted upon a support  20   a  that is V-shaped and associated with the concave reflector  12  by being arrayed along the circumferential rim with the LED light source  18  directing light toward the concave reflector from the edge instead of from the center.  
      The circumferential rim  16  has a mounting groove  28  that can be in the form of a V-shaped trough as shown in  FIG. 3  or as a series of openings, only one of which is shown, in  FIG. 4 . The V-shaped trough can be continuous circumferentially or be formed as one or more discrete areas, depending upon the number of LEDs to be used. The groove  28  is provided with a support retainer  30  that can be in the form of an extending lip  30   a  as shown in  FIG. 3 . In this case the V-shaped support  20   a  can have an original configuration  20   b  and can be compressed to snap-fit into the housing. Alternatively, an angled surface  30   b  as shown in  FIG. 4  can be provided.  
      The support  20  is thermally conductive to remove operational heat from the LED or LEDs and is also provided with the circuitry  32  (shown diagrammatically) necessary to operate the lamp in its chosen environment.  
      When mounted on or near the rim  16  the LED light source  18  is mounted at an angle θ relative to the axis  14  to insure proper alignment. While the angle will, of course, be dependent upon the curvature of the reflector and the particular LED being used, with a parabolic reflector typical of those used for automotive functions, an angle of approximately 30 degrees will provide good results for directing light from the LED  18  onto the surface of the reflector  12 .  
      As a result the LEDs  18  are widely spread around the reflector rim providing improved heat dispersion while concentrating the emitted light on the reflector.  
      No holes are formed in the center of the reflector so no shadows or gaps are created in the resulting beam pattern. The snap fit assembly assures proper positioning of the LEDs  
      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.