Abstract: A squeegee roller system for removing excess developer liquid from the developed-image-bearing photoconductive surface of a drum or the like in which a freely rotatable squeegee roller having a covering of predetermined hardness is biased against the drum to cause excess developer to flow into a receptacle having a weir over which the liquid flows back to the supply tank and in which a fur or pile-covered cleaning roller contacting the squeegee roller is driven in the opposite direction from and at a speed slightly greater than that at which the drum drives the squeegee roller with lower portions of both rollers passing through developer liquid retained by the weir and in which a cleaning blade is biased into engagement with the cleaning roller.

Abstract: A self-cleaning developer applicator system for applying liquid developer to a latent electrostatic image carried by an organic photoconductor supported on a conductive substrate which moves relative to a developer station in which a biasing potential is applied between the substrate and a conductive developer applicator electrode to reduce the effect of the background potential of the latent image while adequately developing desired image areas together with means for cleaning the applicator electrode continuously during operation of the system to remove toner particles which collect thereon under the influence of the biasing potential. In a preferred embodiment the applicator is arranged to flow a film of developer liquid at the speed of movement of the photoconductive surface over a relatively extended area of the image during development thereof.