Preserved image electrostatic copier - uses control grid and cleaner cut=off to preserve latent image on drum for up to 200 good quality copies

摘要

An electrostatic copier of the drum transfer type is such that the electrostatic latent image is not destroyed., by choice, so that several prints may be made from it at high speed and of high quality. The latent image on the drum surface passes through a magnetic brush developer so that a picture is formed on the drum surface which can be transferred to the copy material. Between the conducting rollers there is an electrically conducting grid mesh situated between drum and corona discharge electrode. Controlling the potential applied to this grid and the conducting rollers from two potential sources determines whether the copier produces single or up to 200 good quality copies and whether the latent image cleaning brush and electrode removes the image ready for another exposure.