Patent ID: 6361148
Filing Date: 2002-03-26
Classification: B41J,G03G

Abstract:
A direct electrostatic printing device comprising at least two pigment particle sources providing pigment particles, a voltage source, at least one printhead structure, and a control unit, the at least one printhead structure and an image receiving member moving relative to each other during printing, the image receiving member having a first face and a second face, the at least one printhead structure being placed in between the at least two pigment particle sources and the first face of the image receiving member, the voltage source being connected to the pigment particle sources and a back electrode to create an electrical field for transport of pigment particles from the pigment particle sources toward the first face of the image receiving member, the at least one printhead structure including control electrodes connected to the control unit to selectively open or close apertures through the at least one printhead structure to permit or restrict the transport of pigment particles to enable the formation of a multiple pigment image on the first face of the image receiving member, the apertures being aligned in at least one row per pigment particle source in a direction substantially perpendicular to the relative movement between the image receiving member and the at least one printhead structure, each pigment particle source being associated with a part bit map in the control unit for formation of a part pigment image, the control unit being arranged to virtually adjust at least one part bit map positionally to align the part pigment images with each other to enable the formation of a correctly aligned multiple pigment image even though the at least one row of apertures related to one particle source and the at least one row of apertures related to the at least one other particle source are mechanically misaligned.