Patent ID: 6304378
Filing Date: 2001-10-16
Classification: G03B

Abstract:
A rear projection screen assembly comprising:an image source for projecting light image beams;a projection screen having a rear side and a front side, the rear side facing the image source, the front side comprising a light dispersing material for receiving beams from the image source and for deflecting the individual beams to project an image with a substantially homogeneous luminosity over a wide viewing angle;said light dispersing material comprising a plurality of closely arranged, substantially parallel, longitudinally extending reflecting rib lens elements, each having a plane of symmetry and two lateral surface portions;the lateral surface portions of the reflecting rib lenses being total-reflecting with respect to light from the image source, the central portions of the reflecting rib lenses being light transmitting, and the lateral surface portions of neighboring reflecting rib lenses being adjoined by transmitting lenses; andwherein the reflecting rib lenses comprise:first reflecting rib lenses having a plane of symmetry inclined at an angle .psi. with respect to a plane normal to the screen,second reflecting rib lenses having a plane of symmetry inclined at an angle -.psi. with respect to a plane normal to the screen,third reflecting rib lenses having a plane of symmetry normal to the screen, andwherein .psi. differs from 0.degree..