Abstract: A printing device for recording information in the form of toner images comprising a moveable image-forming medium on a support, the surface of which forms a dielectric layer; an image-forming station disposed along the trajectory of the image-forming medium having a magnetic roller with an electrically conductive nonmagnetic outer sleeve with magnets disposed inside the sleeve; a means for supplying electrically conductive toner particles to a linear zone in the image-forming station; and a plurality of electrodes for generating an electric field corresponding to a desired image pattern, said electrodes extending in the direction of movement of the image-forming medium and disposed so as to be insulated from one another and covered by a dielectric layer wherein each electrode can be actuated by a voltage source and each electrode can generate an electric field across the dielectric layer over part of the zone wherein image formation takes place when in the image-forming station.

Abstract: An exposure system for imagewise exposure of a movable light-sensitive layer, dot by dot along a line on the layer, to an electronically modulated light beam such as that of a laser has a narrow slit disposed near the light-sensitive layer in the path of the light beam, the slit being made with a width less than the dimension at the slit of the light beam in the direction of slit width. In this simple way, the laser beam always describes at least one and the same imaging line relative to the light-sensitive layer, even when beam run-out occurs.