Importance

Loading Importance Indicators...

Abstract

Optical multiplexer configurations are designed to minimize the volume of the multiplexer or minimize back focal distance of the lens of a multi-color projection system. The multiplexer employs three liquid crystal modulators under computer control to respectively and selectively transmit beams of three different colors for combination within the multiplexer which projects the combined modulated beams to a projection lens for focusing an image on a display screen. Optical light paths are chosen within the multiplexer by arrangement and configuation of mirrors and dichroic filters to direct the beams along folded paths within the multiplexer for combination and projection through a multiplexer exit window. For minimized volume of the multiplexer all beams are folded within the multiplexer, but two of the color beams are each folded twice in a single common plane which is perpendicular to a plane of folding of the third beam. For a multiplexer configuration providing a minimum back focal distance two of the beams are each folded in two mutually orthogonal planes while the third beam is not folded at all but is projected directly from the modulator to the projector lens together with the two other combined beams. In this minimum back focal length arrangement the point of combination of all three means is positioned close to the multiplexer exit window and is equidistant from each of the modulators.

Loading the Abstract Image...

First Claim