Electrostatic copier with dual purpose development unit - containing charge-neutralising electrode to enable residual toner to be removed from drum

摘要

An electrostatic copier uses the same magnetic brush development unit to develop the latent image as well as clean off any residual toner. The unit comprises a rotating non-magnetic outer sleeve (410) over stationary permanent magnets (420). The toner (430) continuously feeds past a regulator plate (440) to form a cloud around the rotating cylinder carried into proximity with the image carrying drum (1). The copier uses two compont-toner and has a charge-neutralising electrode to enable residual toner to be removed from the drum by the dual purpose development unit.