Patent Publication Number: US-7585089-B2

Title: Light engine

Description:
TECHNICAL FIELD 
     This invention relates to light engines and more particularly to solid-state light engines for providing backlighting. 
     BACKGROUND ART 
     Backlighting for signage has often employed incandescent, fluorescent or neon light sources. Recently, solid-state lighting devices such as, for example, light emitting diodes (LED or LEDs) have made inroads as lighting sources for these applications, because of their low power requirements and long life. However, such LED light sources are frequently difficult to mount or to replace. 
     DISCLOSURE OF INVENTION 
     Therefore, it is an object of the invention to obviate the disadvantages of the prior art. 
     It is another object of the invention to enhance lighting devices. 
     These objects are accomplished, in one aspect of the invention, by the provision of a light engine that comprises; a light engine subassembly having a housing having a longitudinal axis, the housing including a tubular portion with a surrounding wall and a closed end; a slot formed in the surrounding wall terminating at the closed end; a solid-state light source mounted adjacent the closed end, the solid-sate light source having energizing wires attached thereto and exiting the housing via the slot; and a light dispenser having a first end fixed in the tubular portion and extending for a given distance along the longitudinal axis. 
     This light engine can be made in modular format for multiple arrangements and provides easy mounting and maintenance. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side elevational view of an embodiment of the invention; 
         FIG. 2  is an enlarged, sectional view of a light engine subassembly; 
         FIG. 3  is an end view of the light engine subassembly; 
         FIG. 4  is a perspective view of sealer for use with the subassembly; and 
         FIG. 5  is an end view of a reflector housing. 
     
    
    
     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 light engine  10  comprising a light engine subassembly  12  comprising a housing  14  having a longitudinal axis  16 . The housing  14  is formed from a material having good thermal conductivity and die-cast zinc is preferred. The housing  14  includes a tubular portion  18  with a surrounding wall  20  and a closed end  22 . A slot  24  is formed in the surrounding wall  20  and terminates at the closed end  22 . 
     A solid-state light source  26 , preferably a light emitting diode, is mounted adjacent the closed end  22  by a thermal adhesive  40 . The solid-sate light source has energizing wires  26   a  and  26   b  attached thereto and exit the housing via the slot  24  for connection to an appropriate power source. 
     A light dispenser  36  in the form of an acrylic rod  27  has a first end  37  fixed in the tubular portion  18  and extends for a given distance along the longitudinal axis  16  to a second end  42  fixed in a reflector housing  44 . 
     The reflector housing  44  has a tubular body  46  with a closed end  48  having a reflector coating  50  thereon and is preferably constructed of ABS. 
     Both the light engine subassembly housing  14  and the reflector housing  44  have a plurality of crush ribs  28  spaced about the interior surfaces thereof to grasp and center the acrylic rod  27 , which is subsequently sealed in position by the application of a clear acrylic potting material that is dispensed into the interior of the cup-shaped portions formed by the closed ends and surrounding sidewalls. 
     Prior to dispensing the acrylic potting material, the wire-receiving slot  24  is sealed by a plug  34 . Alternatively, the slot  24  can be sealed by the application of a piece of tape. 
     The light engine subassembly housing  14  and the reflector housing  44  are provided with mounting means  30 . The mounting means  30  can preferably comprise extending flanges  30   a  having elongated mounting apertures  30   b  formed therein for receiving threaded studs such as bolts or screws. 
     Thus there is provided a light engine that is easy to mount, has long life and ready adaptability to many lighting applications. The length of the acrylic rod, as well as its shape can be varied to fit many situations. Further, multiple light engines can be arranged in arrays to provide lighting over a wide area. The power, color and number of LEDs can be varied to supply many solutions. 
     While there have been shown and described what are at 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.