Patent ID: 6199971
Filing Date: 2001-03-13
Classification: B41J

Abstract:
A direct electrostatic printing device comprising:a pigment particle source, which provides pigment particles;a voltage source;a control unit;at least one 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 at least one printhead structure move relative to each other during printing, resulting in a relative movement of the at least one printhead structure and the image receiving member;the image receiving member has a first face and a second face;the at least one 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 at least one printhead structure are responsive to the control unit to thereby selectively open or close the apertures through the at least one printhead structure to permit or restrict the transport of pigment particles during print sequences, a predetermined number of which print sequences are included in a print cycle, to thereby enable the formation of a pigment image on the first face of the image receiving member; andthe at least one printhead structure includes deflection electrodes connected to the control unit for controlling the deflection of pigment particles in transport to thereby be able to deflect pigment particles against predetermined locations on the first face of the image receiving member in view of the image which is to be printed by means of predetermined deflection voltages related to each one of the predetermined number of print sequences, where a change of the predetermined deflection voltages of a previous print sequence to the predetermined deflection voltages of a current print sequence is time displaced relative to the beginning of the current print sequence, to thereby enable a faster print speed.