Abstract: An electrophotographic printing system incorporates two sets of moving optical components, one on each side of a projection lens. A document on a platen is scanned by a first set of moving mirrors with the scanned image projected by a lens towards a photoreceptor. A second set of moving mirrors precesses the image onto the photoreceptor. In one embodiment, a drive system commonly drives both the object side and the image side mirrors to provide the required document scan and precess motions. In a second embodiment, the image side system is driven as a function of the photoreceptor (process) speed.

Abstract: The invention discloses the use of a corrector element placed in an imaging system to selectively vignette energy emanating from the exit pupil of a lens as a function of the field angle of the lens. Several imaging systems are disclosed which illustrate the technique used in determining optimum design and location of the corrector elements.

Abstract: Briefly, the present invention is concerned with a low inertia scanning system for projecting an image of a stationary object on a flat platen onto a rotating photoreceptor drum. An aperture plate located adjacent the photoreceptor drum moves in a direction opposite the direction of the drum. A carriage disposed between a stationary lens and the photoreceptor drum supports a pair of mirrors. The light image is projected from the lens to one of the pair of mirrors for reflection to the second mirror rotating about a pivot point to scan the image through the aperture onto the photoreceptor drum. During scanning of the platen, the carriage moves in a linear direction toward and away from the photoreceptor drum and together with the rotation of the second mirror maintains a constant magnification ratio.