Duplicating system comprising electrophotographic copier and option device

摘要

A duplicating system comprises an electrophotographic copier which includes a first document detecting switch, a first optical scanning system for making a slit exposure, a first document feeder for feeding a first document to be copied at a first speed with respect to the first optical scanning system, a rotating photosensitive drum for forming an electrostatic latent image corresponding to the image of document, and apparatus for forming a duplicated copy with the aid of the latent image. An option device is detachably mounted onto the copying apparatus and comprises a second document detecting switch, a second optical scanning system for making a slit exposure, a second document feeder for feeding a second document to be copied at a second speed with respect to the second optical scanning system and an optional optical system for projecting the image of the second document onto the photosensitive drum. The first document feeder in the copier and the second document feeder in the option device are so constructed that one of them is inhibited to operate for a given time period after the other has been operated.