Patent ID: 6102525
Filing Date: 2000-08-15
Classification: B41J,G03G

Abstract:
A direct electrostatic printing device comprising:a pigment particle source, which provides pigment particles;a voltage source;a control unit;a printhead structure having a plurality of apertures through the printhead structure and having control electrodes proximate to the apertures, the control electrodes being coupled to the control unit;a back electrode; andan image receiving member;wherein:the image receiving member and the printhead structure move relative to each other during printing;the image receiving member has a first face and a second face;the printhead structure is positioned between the pigment particle source and the first face of the image receiving member;the voltage source is connected to the pigment particle source and the back electrode to thereby create an electrical field for transport of pigment particles from the pigment particle source toward the first face of the image receiving member;the control electrodes of the printhead structure are responsive to the control unit to thereby selectively open or close the apertures through the printhead structure to permit or restrict the transport of pigment particles to thereby enable the formation of a pigment image on the first face of the image receiving member; andthe control unit controls the control electrodes of the apertures in view of an available amount of pigment particles to the apertures in relationship to the image to be printed to thereby harmonize a printed image density in view of a desired image density.