Abstract: An electrostatic copying machine includes a reservoir for liquid developer made up of toner particles in a dispersant. A photoconductive drum, adapted after receiving a latent electrostatic image thereon to pass through the liquid developer in the reservoir and to have an electrostatic image developed on the drum. A metering roller for removing excess dispersant is positioned between the reservoir and an air knife which projects a sharp thin jet of pressurized air at about a 45 degree angle with respect to the surface of the drum. The air pressure produced by the air knife drives any remaining spent dispersant on the surface of the drum back to the reservoir by way of the metering roller and the latent image on the drum is subsequently transferred to paper.

Abstract: A multi-jet ink printer comprises a drum having rows of pointed jet formers, or prongs, mounted about its outside surface. The drum is successively rotated such that the tips of the prongs are dipped into a reservoir of ink and thereafter pointed toward a recording carrier, such as paper. When the prongs are directed toward the carrier, an electrostatic field is established between the drum and electrodes located on the opposite side of the carrier. The ink is thereby caused to leave the sharp points and form ink jets composed of very small droplets of ink. The ink is thereby deposited on the carrier. There is an electrode located opposite each prong which is selectively energized to produce dots on the carrier when the prong is in selected positions relative to the carrier. In this respect, the drum is moved axially (horizontally) to scan rows on the carrier, and the carrier is moved longitudinally (vertically) to scan vertically on the carrier.

Abstract: To develop a latent image, which exists in the form of different potential values on different areas of a substrate, an auxiliary substrate is coated with toner by charging the toner triboelectrically and applying a potential to propel the charged toner onto the auxiliary substrate. This toner-coated substrate is brought into close proximity with the image forming substrate, while being maintained at a potential which lies between the different potential values of the latent image.