Counting system for use in a copying machine

摘要

A copy machine includes an optical device for forming an electrostatic latent image of an original document on a photosensitive member, first and second developing apparatuses for developing the latent image on the photosensitive member and a setting system for setting a copying operation mode utilizing the first and second developing units in alternating and sequential operations during a single scanning operation of the optical device. An apparatus is provided for determining whether or not the color developer in the first and second developing units is the same and a prohibiting device prohibits the copying machine from copying through use of both developing units when the determining apparatus determines that the first and second developing units contain the same color developer.