Electrophotographic copying apparatus

In an electrophotographic copying apparatus comprising a photoreceptor having a photoconductive outer surface which photoreceptor is rotatably disposed and movable along a path relative to a plurality of processing stations, such as a corona charging station provided with corona charging means for preliminarily charging said photoconductive outer layer of said photoreceptor, an exposure station including illuminating means for an original to be copied and an optical system for directing a light image of said original onto said preliminarily charged photoconductive surface of said photoreceptor so as to form an electrostatic latent image of said original on said photoconductive surface, a developing station including developing means for developing said latent image into a visible toner powder image, a transfer station including means for transferring said toner powder image onto a transfer material which is fed to said transfer station through a transfer material sheet feed device, and a cleaning station including means for removing residual toner particles on said photoconductive outer surface of said photoreceptor, and a fixing station following said transfer station in the path of the transfer material and including a fixing device for fixing said transferred visible toner powder image on said transfer material, an improvement of said copying apparatus for facilitating maintenance, repairs and replacing components thereof comprising:

• a unit casing in which said photoreceptor, said developing means and said residual toner removing means are integrally and operatively incorporated, and a receptable portion formed in said housing of said copying apparatus for releasably receiving said unit casing.