Light beam deflecting apparatus

摘要

Light beam deflecting apparatus comprised of a hologram formed on the peripheral surface of an open-topped hollow cylinder or on a flat disc rotating at a constant rotational speed. A wavefront control device is provided for adjusting the wavefront of the illuminating light proceeding towards the hologram or that of the scanner light diffracted from the hologram in response to electrical signals applied thereto from a control circuit. These electrical signals are changed in association with the scanning of the diffracted beam so as to enable the diffracted light beam to sweep with its focal point running along a straight line on a flat scanning plane.