Image printing apparatus

Abstract

An image printing apparatus includes a number of image forming units for forming toner images of different colors in alignment on image receiving material in accordance with electronic image information signals fed to each image forming unit. Each image forming unit includes an image forming element rotatable about an axis of rotation and provided with a dielectric surface layer with adjacent electrode tracks in the direction of rotation. Each image forming unit further includes developing devices which include a linear developing magnet situated near the outer surface and parallel to the axis of rotation of the image forming element, toner feed devices for feeding a complete covering of electrically conductive and magnetically attractable toner powder to the image forming element, electrode track activating devices for applying a first or a second printing voltage between an electrode track and the magnet system in accordance with the image information signals to be fed to the image forming units. Toner powder on the passage of the electrode track along the developing magnet remains either on the image forming element or does not remain thereon in the event of a first or second printing voltage respectively on the electrode track. The image printing apparatus also includes at least one image forming unit provided with electronic image line correction devices for feeding image line correction signals to the electrode track activating devices in order to shift in time for each electrode track a printing period in which a printing voltage is applied to the electrode track in accordance with an image information signal.