Polarization luminaire and projection display

Abstract

A polarization luminaire is disclosed having a light source, a system of the optical integrator, a polarized light splitting device for splitting a light emitted from the light source into two kinds of polarized lights whose polarization directions are perpendicular to each other and whose traveling directions are apart from each other by an angle of less than 90 degrees, and a polarization conversion device for causing the two kinds of polarized lights to have the same polarization direction. The polarized light splitting device is placed on one of the entrance side and the outputting side of the first lens plate of the system of the optical integrator or is placed within the second lens plate. A prism beam splitter having a polarized light splitting film constituted by a thermally stable dielectric multi-layer film is suitable for the polarized light splitting device. Most of the polarized lights can be utilized by causing the polarized lights to have the same polarization direction. Further, the polarized lights, which have uniform brightness, can be emitted. Consequently, the polarization luminaire is suited to be a luminaire for use in a projection display that has liquid crystal light valves.

What is claimed is:  
     
         1 . A polarization luminaire, comprising: 
 a light source that emits light having random polarization directions;    a lens plate that includes a plurality of condenser lenses;    a polarization beam splitting prism array that splits each light emitted from each of the plurality of condenser lenses into a p-polarized light and an s-polarized light, the polarization beam splitting prism array including a plurality of polarizing beam splitters and a plurality of reflecting mirrors alternately arranged; and    a half-wave plate placed on an exit side of the polarization beam splitting prism array.    
     
     
         2 . The polarization luminaire according to  claim 1 , further comprising an exit side lens disposed on the exit side of the polarization beam splitting prism array.  
     
     
         3 . The polarization luminaire according to  claim 1 , further comprising a condenser lens array disposed on an incident side of the polarization beam splitting prism array, the condenser lens array having a plurality of condenser lenses.  
     
     
         4 . The polarization luminaire according to  claim 1 , further comprising a condenser lens array disposed on the exit side of the polarization beam splitting prism array, the condenser lens array having a plurality of condenser lenses.  
     
     
         5 . The polarization luminaire according to  claim 1 , wherein a region to be illuminated by the luminaire has an oblong shape, and the polarization beam splitting prism array splits the light along a longitudinal direction of the region.  
     
     
         6 . A projector, comprising: 
 a luminaire;    modulation device that modulates a polarized light outputted from the luminaire; and    a projection optical system that projects a modulated light, wherein the luminaire comprises: 
 a light source that emits light having random polarization directions,  
 a lens plate that includes a plurality of condenser lenses,  
 a polarization beam splitting prism array that splits each light emitted from each of the plurality of condenser lenses into a p-polarized light and an s-polarized light, the polarization beam splitting prism array including a plurality of polarizing beam splitters and a plurality of reflecting mirrors alternately arranged, and  
 a half-wave plate placed on an exit side of the polarization beam splitting prism array.  
   
     
     
         7 . The projector according to  claim 6 , further comprising an exit side lens disposed on the exit side of the polarization beam splitting prism array.  
     
     
         8 . The projector according to  claim 6 , further comprising a condenser lens array disposed on an incident side of the polarization beam splitting prism array, the condenser lens array having a plurality of condenser lenses.  
     
     
         9 . The projector according to  claim 6 , further comprising a condenser lens array disposed on the exit side of the polarization beam splitting prism array, the condenser lens array having a plurality of condenser lenses.  
     
     
         10 . The projector according to  claim 6 , wherein a region to be illuminated by the luminaire has an oblong shape, and the polarization beam splitting prism array splits the light along a longitudinal direction of the region.