Liquid toner extraction apparatus for electrophotographic equipment

Abstract

An electrophotographic printer such as a laser printer uses a liquid toner solution in order to deliver toner having a small toner particle size. A developer roller is immersion coated with the liquid toner solution, and return fluid is scraped from the developer roller with a scraper blade or other wiper in order to provide a clean surface for re-coating the developer roller. The return fluid is reintroduced into the fluid supply stream without adversely affecting image quality while at the same time maintaining a homogeneous coating on the developer roller of fluid supplied to the optical photoreceptor (OPR). The return fluid is maintained in a homogeneous state by the use of a plurality of nozzles which control flow to an immersion bath for the roller. An absorptive nib roller forms a nib for the purpose of separating toner from the OPR, and a pressure roller forcibly removes excess fluid from the nib roller, thereby increasing the efficiency of the nib roller in removing fluid from the OPR. At the end of the image, pressure of the nib roller against the OPR is reduced and the nib roller decompresses at the nib. The invention is further enhanced by the use of a capillary drain between the developer roller and the absorptive nib roller station. Capillary attraction drains toner fluid from the OPR and reduces the load of non-image toner on the nib roller or other extraction device, and has the further advantage of reducing a tendency of toner fluid to travel transversely toward the edges of the OPR.