Polarization recovery system using redirection

Abstract

A polarization recovery system includes a polarizing beam splitter transmitting light of a useful polarization in an output direction and reflecting light of a non-useful polarization in a first orthogonal direction substantially orthogonal to the output direction. An initial reflector may reflect the non-useful polarization light in a second orthogonal direction substantially orthogonal to the output direction and the first orthogonal direction, and a final reflector may reflect the non-useful polarization light in the output direction. The non-useful polarization light may be rotated substantially to light of the useful polarization by the initial and final reflectors.

1 . A polarization recovery apparatus comprising: 
 a polarizing beam splitter transmitting a light of a useful polarization in an output direction and reflecting a light of a non-useful polarization in a first orthogonal direction substantially orthogonal to said output direction;    an initial reflector disposed reflectably to said orthogonal direction, said initial reflector reflecting said non-useful polarization light in a second orthogonal direction substantially orthogonal to said output direction and said first orthogonal direction; and    a final reflector disposed reflectably to said second orthogonal direction, said final reflector reflecting said non-useful polarization light in said output direction;    wherein said non-useful polarization light is rotated substantially to light of said useful polarization by said initial and final reflectors.    
   
   
       2 - 6 . (canceled)  
   
   
       7 . The polarization recovery apparatus of  claim 1 , comprising further: 
 an input light pipe having an input surface and an output surface, said output surface disposed proximate to an input face of said polarizing beam splitter, said input light pipe receiving substantially un-polarized light at said input surface and transmitting said un-polarized light at said output surface to said polarizing beam splitter.    
   
   
       8 . The polarization recovery apparatus of  claim 7 , wherein a shape of said input surface is selected from the group consisting of: 
 flat,    convex,    concave,    toroidal, and    spherical.    
   
   
       9 . The polarization recovery apparatus of  claim 7 , wherein a shape of said output surface is selected from the group consisting of: 
 flat,    convex,    concave,    toroidal, and    spherical.    
   
   
       10 . The polarization recovery apparatus of  claim 7 , wherein said input light pipe is comprised of a material selected from the group consisting of quartz, glass, plastic, or acrylic.  
   
   
       11 . The polarization recovery apparatus of  claim 7 , wherein said input light pipe is selected from the group consisting of: 
 a straight light pipe (SLP), and    a tapered light pipe (TLP).    
   
   
       12 - 16 . (canceled)  
   
   
       17 . The polarization recovery apparatus of  claim 1 , wherein said initial reflector is selected from the group consisting of: 
 a prism,    a right angle prism,    a mismatched impedance, and    a mirror.    
   
   
       18 . (canceled)  
   
   
       19 . The polarization recovery of  claim 1 , wherein said final reflector is selected from the group consisting of: 
 a prism,    a right angle prism,    a mismatched impedance, and    a mirror.    
   
   
       20 . (canceled)  
   
   
       21 . The polarization recovery apparatus of  claim 1 , comprising further: 
 a shell reflector having a first and a second focal points;    a source of electromagnetic radiation disposed proximate to said first focal point of said shell reflector to emit rays of light that reflect from said shell reflector and converge substantially at said second focal point;    wherein said input surface is disposed proximate to said second focal point to collect and transmit substantially all of said light.    
   
   
       22 . The polarization recovery apparatus of  claim 21 , wherein said shell reflector comprises at least a portion of a shape selected from the group consisting of: 
 a substantially elliptical surface of revolution,    a substantially spherical surface of revolution, and    a substantially toric surface of revolution.    
   
   
       23 - 30 . (canceled)  
   
   
       31 . The polarization recovery apparatus of  claim 21 , wherein said source of electro-magnetic radiation comprises an arc lamp.  
   
   
       32 . The polarization recovery apparatus of  claim 31 , wherein said arc lamp comprises a lamp selected from the group consisting of a xenon lamp, a metal halide lamp, a UHP lamp, a HID lamp, or a mercury lamp.  
   
   
       33 . The polarization recovery apparatus of  claim 21 , wherein said source of electromagnetic radiation is selected from the group consisting of a halogen lamp, and a filament lamp.  
   
   
       34 . The polarization recovery apparatus of  claim 1 , comprising further: 
 an image projection apparatus disposed proximate to said output direction to collect substantially said useful polarization light.    
   
   
       35 . The polarization recovery apparatus of  claim 34 , wherein said image projection apparatus is selected from the group consisting of: 
 an LCOS imager,    a DMD chip, and    a transmissive LCD panel.    
   
   
       36 . The polarization recovery apparatus of  claim 21 , wherein a shape of said polarizing beam splitter is matched substantially to an aperture of said source of electro-magnetic radiation.  
   
   
       37 . The polarization recovery apparatus of  claim 1 , wherein said polarizing beam splitter comprises a wire-grid polarizing beam splitter.  
   
   
       38 . A method of polarization recovery comprising: 
 polarizing substantially light into light of a useful polarization and light of a non-useful polarization;    transmitting said useful polarization light in an output direction;    reflecting said non-useful polarization light in a first orthogonal direction substantially orthogonal to said output direction;    reflecting said non-useful polarization light in a second orthogonal direction substantially orthogonal to said output direction and said first orthogonal direction; and    reflecting said non-useful polarization light in said output direction.    
   
   
       39 . A system of polarization recovery comprising: 
 means for polarizing substantially light into light of a useful polarization and light of a non-useful polarization;    means for transmitting said useful light in an output direction;    means for reflecting said non-useful light in a first orthogonal direction substantially orthogonal to said output direction;    means for reflecting said non-useful light in a second orthogonal direction substantially orthogonal to said output direction and said first orthogonal direction; and    means for reflecting said non-useful light in said output direction.