New recording equipment and reproduction electrographic, new methods for recording electrographic and draws thus obtained

摘要

An electrographic apparatus and process for producing, on a record medium having a layer of insulating material in contact with an electrically conductive backing member, an electrostatic charge image corresponding to an image to be recorded comprises an image grid and at least one control grid arranged between a corona discharge device and the layer of insulating material. The image grid comprises an electrically conductive core having insulating and conducting areas defining the image to be produced. The control grid is electrically conductive and arranged in spaced and generally parallel relation to the image grid and between the latter and the corona discharge device. When the core of the image grid and control grid are individually biased to a potential for establishing electrical fields of different strengths between the respective areas and the backing member and a flow of ions is directed toward the grids and the record medium, the flow of ions through the grids is modulated by the electrical fields to produce an electrostatic charge image on the layer of insulating material.