Image display apparatus of liquid crystal valve projection type

A liquid crystal light valve projection image display apparatus comprising:

• an electro-optic element including a pair of substrates, a nematic liquid crystal layer and a photoconductive layer arranged in series and interposed between said substrates, said nematic liquid crystal layer having a dielectric and optic anisotropy, a light blocking mask having striped openings at a fixed spatial period disposed on an input light side of said photoconductive layer, a first means including said mask and photoconductive layer for supplying a first electric field in a two-dimensional voltage pattern having a fixed striped spatial period to said liquid crystal layer to produce first areas of said layer where the molecules thereof are reoriented away from a predetermined molecular orientation by a voltage potential of said electric field and second areas of said layer not exposed to a voltage potential of said electric field where said molecules continue to have said predetermined molecular orientation, thus forming a phase diffraction grating in said liquid crystal layer, and second means for supplying said liquid crystal layer with a second electric field having a spatially distributed intensity corresponding to an electrical or optical input image signal representing a two-dimensional image;
• image supply means for electrically or optically supplying said input image signal to said electro-optic element;
• and,
• a Schlieren optical system for projecting image information formed in said liquid crystal layer as said phase diffraction grating on a screen by using light diffracted from said phase diffraction grating.