Electrostatographic apparatus

摘要

An improved method for varying the Gamma in a TESI electrostatic imaging system is disclosed which provides for positioning a surface of a photoconductive body and a surface of a dielectric body in virtual contact whereby an air gap exists between a portion of the surfaces. The photoconductive body is imaged by exposure to electromagnetic radiation in image configuration while an electric potential difference is simultaneously established across the photoconductive and dielectric bodies. The resulting field in illuminated areas has a magnitude for causing ionization in the air gap and causing a charge pattern to transfer to the dielectric body. The process Gamma is controlled by employing a pulse imaging technique. Pulse imaging is provided by repeatedly interrupting the potential difference, the exposure or both.