Patent Publication Number: US-6908211-B1

Title: Magnified lighting device

Description:
BACKGROUND OF THE INVENTION 
   The instant invention is directed to a flashlight illuminator which employs an LED light source in combination with a light ray assimilating and magnifying adapter or barrel which acts to accumulate and project the light emitted by the LED in a concentrated light beam over extended distances. 
   Traditional incandescent flashlights all have the ability to produce and project a confined light beam over a great distance while maintaining high intensity. The traditional flashlights use light bulbs and power sources i.e., batteries which have a limited life expectancy. 
   On the other hand, flashlights using Light Emitting Diodes (LED&#39;s) operate with a life expectancy which is typically a hundred fold greater than the incandescent products. The LED devices all have the same limitations i.e., a lack of light projection or light projection over limited distances and light projection of limited intensity. 
   There have been attempts to improve light projection and intensity of LED flashlights by using a concave reflecting dish, similar to that used in incandescent flashlights. These dishes were found to provide a more uniform light beam, however, it is highly defused and dim. 
   Accordingly, the instant invention has for its primary object to provide an adapter for use with an LED light source which acts to amplify, magnify and project the light produced by the light emitting diode. 
   Another object of the invention is the provision a flashlight with an LED light source which projects a light beam a distance substantially equivalent to that of an ordinary flashlight. 
   Another object of the invention is a penlight adapter capable of concentrating and magnifying the light emitted by the penlight in the form of a compact beam. 
   Another object of the invention is an adapter for attachment with a penlight having an LED light source which is capable of concentrating, magnifying and directing the light in the form of a concentrated beam. 
   Another object of the invention is the provision of an inexpensive adapter for use with LED lighting units. 

   
     DESCRIPTION OF THE DRAWINGS 
     The construction designed to carry out the invention will hereinafter be described, together with other features thereof. 
     The invention will be more readily understood from a reading of the following specification and by reference to the accompanying drawings forming a part thereof, wherein an example of the invention is shown and wherein: 
       FIG. 1  is a cutaway side view of the adapter in position with a penlight. 
       FIG. 2  is a cutaway side view of a variation of the arrangement shown in  FIG. 1 . 
       FIG. 3  is a cutaway side view of the penlight with adapter showing light beams paths through the chamber and magnifying glass of the adapter. 
   

   DESCRIPTION OF A PREFERRED EMBODIMENT 
   Referring now to the drawings, the invention will now be described in more detail. 
   As can best be seen in  FIG. 1 , the adapter  10  is shown connected with a penlight  12  which is of the type which uses LED light source  14 . Penlight  12  comprises a casing or body portion which carries a usual power supply. An on/off switch  16  is provided to direct power to the LED and to interrupt the power to the LED as desired. While a penlight is shown, it is noted that the adapter concept of the invention is equally usable with other types of LED flashlight illuminators. 
   Adapter or barrel  10  comprises an elongate tube or cylindrical encasement  18  preferably formed of plastic and formed to a length of about 1.5 to 3 inches with an inner diameter sufficient to receive forward end  19  of penlight  12 . Tube  18  carries adjacent one end at least one “O” ring  20  for engaging with the outer surface of the penlight for securing and maintaining the adapter in position on the penlight. It is noted any other known securing or retaining arrangement may be substituted for “O” ring  20 . Adjacent the opposite end and formed in the inner surface of adapter  10  is groove  22  which is about 0.03 inches in depth. Groove  22  is adapted to receive and secure magnifying lens  24  in position within the bore of tube  18 . Between groove  22  and “O” ring  20 , a raised ring  26  is formed about the inner surface of tube  18 . Ring  26 , along with lens  24  and the inner wall  31  of tube  18  define a substantially cylindrical cavity  30 . The inner wall  31  of tube  18  is covered or lined with a reflecting member  32  which extends from ring  26  to lens  24 . 
   Reflector  32  may be a separate piece formed of metal, plastic or paper with a glossy reflective inner surface or it may simply be a coating applied to inner wall  31 . It is preferred that the reflecting surface be white although other colors or a mirror surface could be used. 
   Inner opening  28  of ring  26  is designed to engage and position the forward end of penlight  12  and more particularly, LED  14  in fixed position relative to lens  24 . This is because the size of cavity  30  is critical. 
   It has been found to be most desirable that the diameter of cavity  30  be within a range of 0.375 to 1.25 inches and that the cavity length be 0.749 to 0.751 inches. Also, it has been found that lens  24  be a plano-convex lens with a diameter just slightly larger than the diameter of cavity  30  and a focal length of between 0.50 to 1.5 inches is most desirable. Further, it is preferred that the convex side of lens  24  have a radius of between 0.361 and 1.765 inches. Preferably, the lens is clear acrylic. 
   As earlier noted, the length of cavity  30 , which defines the focal length of the adapter, is critical. For that reason, it is preferred that tube  18  be formed as a single unit. Ring  26  along with “O” ring  20  act to secure the penlight and more particularly LED  14  in fixed position relative to reflector  32  and lens  24 . 
   In operation, penlight  12  is activated by switch  16  causing LED  14  to emit light. As best shown in  FIG. 3 , the light rays  34  emerging from LED  14  are defused in all directions. The light rays when engaging reflector  32  are redirected and collected into lens  24 . Lens  24  then acts to magnify the collected light rays delivering a condensed light beam  36  over a distance more than 10 times the normal projection length of a LED penlight and with an increase in brightness of at least 25%. It is preferred that the beam diameter be controlled to have a diameter of no more than 12 inches at a distance of 8 feet from lens  24 . The adapter is capable of controlling the beam diameter to be between 2 to 120 inches at a distance of 150 feet. The beam diameter selected is dependent upon the intended use. 
   It is noted that any of the known LED chips may be used with adapter  10  with similar results. 
   Turning now to  FIG. 3 , adapter  10  is shown substantially as described in  FIG. 1  with the exception being the structure the bore forming cavity  30 . In the arrangement shown in  FIG. 3 , inner wall  31  is formed with a slight step down  33  adjacent inner ring  26 . Step down  33  is very slight reducing the diameter of cavity  30  by between 0.75 and 0.25 inches. Reflector  32  is again arranged over the entire inner wall  31 . Primarily, the purpose of step down  33  is to provide for a lens with a slightly larger diameter which is sometimes desirable. 
   Turning now to  FIG. 2  adapter  10  is shown with tube  18  formed as two interconnected members  38   a  and  38   b  interconnected with a threaded connection  40  which allows for longitudinal adjustment of cavity  30  by simply turning outer member  38   b  in the desired direction. 
   Again like elements are identified with the same numerals throughout to include lens  24 , LED  14  and penlight  12 . Reflector  32  may comprise overlapping pieces  42   a ,  42   b  which completely cover the inner surface of tube  18  and yet have the capability of slight longitudinal movement to accommodate axial adjustment of the cavity. It is intended that axial adjustment be limited to between 0.361 and 1.765 inches. 
   While a preferred embodiment of the invention has been described using specific terms, such description is for illustrative purposes only, and it is to be understood that changes and variations may be made without departing from the spirit or scope of the following claims.