Electrographic process of imaging by modulation of ions

An electrographic process of producing, on a dielectric coated record medium, an electrostatic copy latent image by modulating a flow of corona ions with the aid of an electrostatic latent image which has been produced on a photoconductive photosensitive screen, characterized by making a ratio K of a maximum surface potential V volts of the electrostatic copy latent image produced on said dielectric coated record medium to an intensity of the electric field E volts/mm established between said photoconductive photosensitive screen and said dielectric coated record medium, i.e. K=V/E smaller than about 0.18 for the purpose of preventing enlargement of dots of the copy picture image, said intensity of the electric field E established between said photoconductive photosensitive screen and said dielectric coated record medium being about 500 to 1,000 volts/mm.