Patent ID: 6109729
Filing Date: 2000-08-29
Classification: B41J,G03G

Abstract:
A device for direct electrostatic printing on a substrate, comprising:a back electrode disposed on one side of said substrate, and supplied with a back electrode voltage;a toner source arranged on an opposite side of said substrate from said back electrode, and supplied with a source voltage different from said back electrode voltage, for causing a flow of toner particles from said toner source toward said substrate and said back electrode; anda printhead structure disposed between said substrate and said toner source, said printhead structure comprising (i) an insulating layer having a first side and a second side separated by an elongated slit aperture, said slit aperture having a lengthwise dimension and a widthwise dimension, the lengthwise dimension of said slit aperture extending along said sides and the widthwise dimension of said aperture extending between said sides, and said insulating layer being made of at least one insulating sheet, and (ii) control electrodes disposed only on said first side and along the lengthwise dimension of said slit aperture, said control electrodes being supplied with a first control voltage substantially equal to said source voltage to permit maximum flow of toner particles through said slit or a second control voltage, having polarity with respect to said source voltage which is opposite from said back electrode voltage to stop said flow of toner particles.