Copying system featuring combined developing-cleaning station alternately activated

摘要: Electrophotographic copying apparatus has charging, imaging, transferring, precleaning, and erasing facilities in a conventional sense but incorporates combined developingcleaning unit that is operable to perform either function at the proper time during sequence. A first version photoconductor drum structure surrounded with necessary electrophotographic elements including single developer-cleaner unit. Another belt movable forwardly reversely. In version, cleaning cycles may alternate developing or be activated following production of high number images on surface. Conveniently, magnetic brush element forms contacting surface for conveying toner onto scavenging residual from by bringing developer mixture into contact cleaning. Appropriate changes biasing are made operation.