JPS5532062A - Electrophotographic method - Google Patents

Abstract

PURPOSE:To suitably select the elastic layer of an elastic roller and make possible high speed developing by pressure contacting the roller to an electrostatic latent image carrier, squeezing out and supplying developing solution through its compression and restoration and recovering excess solution thereby performing developing. CONSTITUTION:A developing roller 14 is partly dipped in developing solution 12 in a liquid vessel 13 and a refresh roller is pressure contacted thereto. The developing roller 14 comprises providing a porous elastic material 17 such as foamed polyurethane or other around the central body 16 and enclosing said material with netting 18 in endless form. When a photosensitive drum 6 and developing roller 14 are pressure-contacted and revolved, the developing roller 14 contains the developing solution sufficiently and makes contact with the photoreceptor 6 to form a nip part a. Developing is accomplished by the developing solution squeezed out (c part) and the developing solution in the a part. At the time when the developing roller 14 detaches from the photoreceptor 6, the elastic material 17 restores from the compressed state and therefore it draws in the excess developing solution near the photoreceptor and further the exchanging and replenishing of the developing solution is accomplished through pressure contact of the refresh roller 15. The layer thickness of the abovementioned elastic body 17 is made 1.0-10mm, whereby solution suction action is made sufficient and high speed developing made possible.