Illumination device utilizing displaced radiation patterns

Abstract

In one embodiment, the invention is directed to an illumination device. The illumination device includes a light emitting diode that emits a radiation pattern, wherein a maximum luminous intensity of the radiation pattern is displaced relative to a center axis of the light emitting diode. The illumination device may also include a number of light guides positioned to be illuminated by the light emitting diode. The invention utilizes the “batwing” radiation pattern of a light emitting diode to effectively illuminate a number of light guides with a single light emitting diode. Each light guide is offset from a center axis of the light emitting diode to capture light that is annularly displaced. This offset positioning of the light guides allows the light guides to effectively capture light from the light emitting diode where light intensity is greatest.

1 . A sign comprising: 
 a frame;    a light emitting diode housed within the frame;    a first light guide positioned to be illuminated by the light emitting diode, wherein the first light guide provides directional side lighting in a first direction; and    a second light guide positioned to be illuminated by the light emitting diode, wherein the second light guide provides directional side lighting in a second direction.    
   
   
       2 . The sign of  claim 1 , wherein the frame is formed with holes and the each light guide protrudes through at least one of the holes.  
   
   
       3 . The sign of  claim 1 , wherein the light emitting diode is a first light emitting diode, the sign further comprising a second light emitting diode housed within the frame, wherein the first and second light guides are positioned to be illuminated by the second light emitting diode.  
   
   
       4 . The sign of  claim 1 , wherein the first and second light guides provide lighting in different colors.  
   
   
       5 . The sign of  claim 1 , wherein the light emitting diode emits a radiation pattern, wherein a maximum luminous intensity of the radiation pattern is displaced relative to a center axis of the light emitting diode.  
   
   
       6 . The sign of  claim 5 , wherein each of the first and second light guides is positioned to be illuminated by the light emitting diode at offset locations relative to the center axis of the light emitting diode.  
   
   
       7 . The sign of  claim 6 , wherein each of the first and second light guides is positioned such that a cross-sectional center of each light guide substantially corresponds to locations of the maximum luminous intensity of the radiation pattern of the light emitting diode.