Multi-color image forming apparatus with black and white image forming mode

摘要

In a multi-image forming apparatus having a plurality of electrophotographic photosensitive members and adapted to form a multi-image by sequentially transferring image formed on the photosensitive drums onto a transfer sheet, it is possible to the service life of the photosensitive member having the higher frequency in use. To this end, the photosensitive member having the higher frequency in use has a different construction which differs from those of the other photosensitive members. Further, if necessary, an image forming method by the photosensitive member having such different construction is differentiated from those by the other photosensitive members.