Light tube system for distributing sunlight or artificial light singly or in combination

Abstract

Hybrid lighting systems use light distributor tubes to distribute artificial light and natural sunlight through the same distributor tubes. Devices for gathering uncollimated light from conventional sources (such as electrically energized arcs or filaments housed in evacuated or gas filled glass envelopes) and directing the light into the ends of tubes designed to distribute such light. Devices for gathering and concentrating inherently collimated sunlight to be fed into the same light distributing tubes used by the artificial light. One preferred embodiment comprises a light gathering and concentrating system in the form of a pair of opposed parabolic reflectors, one which is preferably large, e.g. having a diameter of five feet, and the other much smaller, e.g. the size of the much smaller distribution tubes. This light gathering system is connected to the light distribution tubes through a pair 90° elbows which are rotatable in the X and Y axis in order to track the location of the sun in the sky. The two parabolic reflectors are positioned to share a common focal point so that the larger reflector will direct the sunlight through the focal point of the smaller reflector, which will, reflect the light as concentrated, collimated light. A central aperture in the larger reflector passes the concentrated beam on its way to the distribution tubes.

1 . A hybrid lighting system comprising: 
 means for concentrating sunlight;    a light distributor tube comprising two ends, a longitudinal axis and means for redirecting light entering an end of said tube out of said tube away from said longitudinal axis; and    means for directing concentrated sunlight into said light distributor tube.    
   
   
       2 - 14 . (canceled)  
   
   
       15 . A hybrid lighting system according to  claim 1  comprising means for aiming said sunlight concentrating means toward the sun.  
   
   
       16 . A hybrid lighting system according to  claim 15  wherein said aiming means comprises at least two reflectors disposed in two relatively rotatable supports, wherein a first rotatable support is rotatable about a first axis and a second rotatable support is rotatable about a second axis which is perpendicular to said first axis.  
   
   
       17 . A device for changing the size of a substantially collimated beam of light comprising: 
 a first generally parabolic reflector comprising a first focal length;    a second generally parabolic reflector comprising a second focal length which is different from said first focal length, wherein said first reflector and said second reflector are positioned to have a common focal point.    
   
   
       18 . A device for changing the size of a substantially collimated beam of light according to  claim 17  wherein said first reflector and said second reflector are positioned to have a common longitudinal axis.  
   
   
       19 . A device for providing collimated artificial light comprising: 
 an elliptical reflector comprising a first focal point and a second focal point;    a parabolic reflector comprising a focal point;    a source of artificial light positioned at said first focal point of said elliptical reflector;    wherein said elliptical reflector and said parabolic reflector are positioned so that said second focal point of said elliptical reflector is common to said focal point of said parabolic reflector.    
   
   
       20 - 44 . (canceled)