A latent image formed on a photosensitive member in exposure operations is developed
into a toner image, which is then transferred onto an image bearing member in primary
transfer operations. Afterward, the toner image is transferred onto a recording
sheet in secondary transfer operations. A cleaning unit for cleaning the image
bearing member by removing residual toner therefrom is brought into and out of
contact with the surface of the image bearing member at a time when neither the
exposure operations nor primary transfer operations are being performed.
