Projection display apparatus

Abstract

A projection display apparatus that is lightweight and provides bright, high quality images is provided. The projection display apparatus comprising a color separation and synthesis optical system 4 , that performs color synthesis, generating an image, after separating light of the three primary colors of determined polarities into the respective three colors, and modulating those three color lights in relation to respective image signals therefor, and a projection lens 106 . The color separation and synthesis optical system 4 comprises polarized light separating means 8, 9, 11 and 16 disposed in respective diagonal directions therein and reflecting spatial light modulating elements 12, 13 and 14 disposed to perform light modulation coordinated to an image signal for each respective color, for light separated according to polarization by the four polarized light separating means 8, 9, 11 . Three spatial light modulating elements 12, 13 and 14 are disposed on the outer side of the polarized light separating means 9, 11 and 16 , other than the polarized light separating means 8 , that is disposed on that side of incident light, at least two from among the four polarized light separating means 8, 9, 11 and 16 are wire grid polarized light separating plates and an astigmatism correcting lens 21 is provided between the polarized light separating means 16 disposed on that side at which projection is performed and at least one of the spatial light modulating elements.

1 - 3 . (canceled)  
   
   
       4 . A projection display apparatus comprising: 
 a color separating and synthesis optical system comprising a first light separating means, a second light separating means, a third light separating means and a fourth light separating means wherein said first, second, third and fourth light separating means are disposed in respective diagonal directions therein, said first light separating means is disposed on that side on which illuminating light is incident and said fourth light separating means is disposed on that side at which projection is performed, a first reflective type spatial light modulating elements disposed on either the opposite side with respect to that side of said second light separating means on which said first light separating means is disposed or the opposite side with respect to that side on which said fourth light separating means is disposed, a second reflective type spatial light modulating elements disposed on the opposite side with respect to that side of said third light separating means on which said first light separating means is disposed, and a third reflective type spatial light modulating elements disposed on the opposite side with respect to that side of said third light separating means on which said fourth light separating means is disposed, in which color separating and synthesis optical system, after light including light of the three primary colors is separated into the respective primary colors by said first, second and third light separating means, and after each respective color undergoes modulation coordinated to an image signal for each respective color and is reflected by the respective said first, second and third reflective type spatial light modulating elements, color synthesis is performed and a color image is generated by said second, third and fourth light separating means; and    a projection lens for expansively projecting said color image generated by said color separating and synthesis optical system;    wherein said first light separating means is a first dichroic separating means, said fourth light separating means is a second dichroic separating means or a polarized light beam splitter means, said other light separating means are wire grid polarized light separating plates, and a lens for correcting astigmatism is disposed near the side of the reflective surface of at least one from among said first, second and third reflective type spatial light modulating elements.    
   
   
       5 . A projection display apparatus according to  claim 4  wherein said astigmatism correcting lens is a cylindrical lens.  
   
   
       6 . A projection display apparatus according to  claim 5  wherein the surface of said cylindrical lens is an aspheric, toroidal surface.  
   
   
       7 - 10 . (canceled)