IT1098120B - Ion generator for electrostatic printing - uses gas breakdown in electric field between two electrodes separated by dielectric - Google Patents

Abstract

An ion generator includes a solid dielectric plate (21) with a first electrode (22-2) on one face and an air gap (21-h) at a junction of the electrode and dielectric plate. A second electrode (22-1) is supported on the opposite surface of the plate, and an AC potential (24A) is applied between the electrodes to produce a discharge by breakdown of the air gap. The ions are extracted and used for electrostatic printing by forming an electrostatic latent image with the extracted ions, and the latent image is toned and fused. The latent image is formed on a dielectric layer (25-d) and the toned latent image is transferred onto plain paper (25) to form a visible image. The ions may be extracted by a DC voltage (24B) applied to the first electrode, with a gap patterned in accordance with the shape of a character for which a charge image is required. The generator produces ions of high current density in a stable manner over long periods without periodic maintenance. The ion source is multiplicable using different voltage sources to supply the AC breakdown field and the ion extraction field. The source enables uniform charge images to be achieved, which can be toned with good definition and dot fill.