A light beam deflection system for producing diffracted light having a holographic light beam deflection disc bearing a record of unidimensional fringe patterns along the radial axis on a time division basis over a circumferential portion of the disc, and having means for focusing coherent light beams...http://www.google.com/patents/US3940202?utm_source=gb-gplus-sharePatent US3940202 - Light beam deflection system
