Abstract: In an electrostatic ink jet printer, all nozzles of a printhead are spaced generally the same distance from a moving paper print substrate. Three voltage levels are selectively applied to each nozzle of the printhead. As the paper moves past the printhead, a bias voltage Vb is applied to all nozzles which have a static protruding meniscus which shape is determined by a balance between the internal pressure, surface tension, and bias voltage. When the paper arrives at a print row, nonprinting nozzles have a shadow voltage pulse Vs, the "shadow pulse," applied thereto, and printing nozzles have a higher magnitude print pulse Vp applied thereto. The magnitude of the shadow pulse Vs causes an additional excursion of the ink meniscus to form at each non-printing nozzle. The higher magnitude of print pulse Vp causes an ink filament to move from a printing nozzle to the paper.
Type:
Grant
Filed:
October 23, 1995
Date of Patent:
July 13, 1999
Assignee:
imaging Technology international
Inventors:
Ross Neal Mills, James Elwood Kerr, Jon-Christophe Bernard Febvre