A direct electrostatic printing device and method for printing an image to an information carrier with increased density harmonization. By continuously keeping track of the amount of pigment particles each aperture has available and thereafter using this information and the desired print density to control...http://www.google.de/patents/US6102525?utm_source=gb-gplus-sharePatent US6102525 - Method and apparatus for controlling the print image density in a direct electrostatic printing apparatus
