Projector

Abstract

To provide a thin projector, such as a rear projector, formed by a less expensive projection optical system which is easy to assemble and install, and performing a highly accurate projection, projection light PL projected with a projection optical system onto a screen is linearly polarized light having a polarization azimuth along the longitudinal direction of the screen. With this arrangement, the right and left ends of the rear surface of the screen maintain a low reflectance, thereby reducing a loss in quantity of illumination light when passing through the screen, in other words, achieving high luminance of an image projected onto the screen while maintaining its uniformity of brightness.

1 . A projector, comprising: 
 an illumination device to emit illumination light;    spatial light modulation devices illuminated with illumination light emitted from the illumination device;    a projection optical system including an L-shaped optical unit to bend a light path, having a pair of lens groups and reflecting device interposed therebetween and which projects image light emitted from the spatial light modulation devices via the optical unit; and    a screen onto which the image light passing through the projection optical system is projected.    
     
     
         2 . The projector according to  claim 1 , the screen being a rear projection screen, and the optical unit directly focuses the image light emitted from the spatial light modulation devices onto the screen.  
     
     
         3 . The projector according to  claim 1 , the optical unit having an optical axis bent on a vertically extending plane orthogonal to the screen.  
     
     
         4 . The projector according to  claim 3 , the illumination device disposed such that the optical axis of a lamp serving as a light source to generate illumination light lies horizontally.  
     
     
         5 . The projector according to  claim 1 , an exit-side optical axis of the projection optical system being orthogonalized to a surface of the screen extending along the central part of the screen.  
     
     
         6 . The projector according to  claim 1 , further comprising: 
 a color modulation device including the spatial light modulation devices for corresponding colors, each device being illuminated with corresponding illumination light emitted from the illumination device; and a light-separation modulation device which includes a light-synthesizing member to synthesize corresponding kinds of color image light emitted from the color modulation device and which emits the synthesized image light,    the projection optical system projecting the image synthesized with the light-synthesizing member onto the screen.