Hologon Laser Scanners For Nonimpact Printing

A novel holographic laser beam deflector is described which is invariant with regard to deflector wobble and centration errors, has high radiometric efficiency and provides a bow free scan. The deflector's insensitivity to mechanical error and absence of facet pyramidal error enables a flat field, linearized, high resolution image to be generated utilizing only a simple spherical optical system. In addition to the cost benefits derived from using spherical optical elements, the inherent symmetry they provide readily enables the deflector system to be extended to two dimensional scanning applications. Performance data for a hologon deflector system operating at 633 nm will be presented. Also, a procedure for determining what parameters must be incorporated into the hologon deflector element for nonimpact printing applications will be outlined.