Method and apparatus for controlling ion trajectory perturbations in ionographic devices

摘要

In an ionographic device projecting a stream of ions towards a moving imaging surface, modulated in imagewise fashion, an array of control electrodes corresponding to the ion stream modulating array of electrodes, is arranged adjacent to the path of the ion stream and between the source of the modulated ion stream and the imagaing surface, biased with a voltage preventing previously deposited charge from pertubing the trajectory of subsequently projected ions to limit the amount of ion beam deflection caused by the presence of electrostatic charge patterns on the electroreceptor. The control electrode voltage increases with the period over which the modulation electrode has allowed the flow of ions therepast.