Three dimensional television system and projection television receiver

Claim 1

A three dimensional projection television system including a pair of television cameras each viewing a scene from different predetermined positions and each generating picture signals which upon receipt by an associated television receiver would produce picture fields on its receiver; a transmission system; a switch receiving the picture signals from each camera, said switch alternately connecting said cameras to said transmission system so that the picture signals received from said cameras alternate field by field between those generated by one camera and those generated by the other, a projection television receiver with red, green and blue projectors and a screen, said receiver receiving said transmitted field signals and projecting the associated fields on said screen; polarizer means disposed in front of said screen, said fields being transmitted through said polarizer means; electro-optical apparatus disposed in front of said screen, said apparatus including a separate electro-optical crystal device for each projector, said fields being transmitted through said electro-optical crystal devices; and control means connected to said electro-optical crystal devices and controlling their characteristics from field to field so that said screen alternately receives a field as polarized by said polarizer means and a field which is orthogonally polarized with respect to the fields polarized by said polarizer means whereby a viewer viewing said screen through glasses, the lenses of which are appropriately orthogonally polarized with respect to each other, perceives the screen to be providing a three dimensional image, said control means applying a different voltage to each of the crystal devices for the red, green and blue projectors during every other field, each said different voltage being different from each other.