An image-forming apparatus includes a pre-charge exposure device which removes
electric charge from a photoconductor drum to increase a potential contrast between
the surface of the photoconductor drum and the surface of a charge roller in an
upstream region of a nip region between the photoconductor drum and the charge
roller in the rotating direction of the photoconductor drum, so that toner accumulating
in an upstream region of the nip region in the rotating direction of the photoconductor
drum is restrained and prevented from being discharged onto an image-forming region.
When the toner accumulating in the upstream region of the nip region in the rotating
direction of the photoconductor drum is to be discharged onto a non-image-forming
region, the pre-charge exposure device is turned off so that the potential contrast decreases.