Abstract: Upon occurrence of jamming in an apparatus, an electrification unit 4 ceases electrification of a surface of a photosensitive drum 3 and, simultaneously, an exposure unit 5 starts to expose the entire surface in a width direction to light. Further, a development unit 6 forms a toner adhesion region T on the photosensitive drum 3 and, also, stops a drum motor and a belt motor in such a manner that the toner adhesion region T stops at a transfer nip section N. Thus, it is possible to alleviate a rub between the photosensitive drum 3 and a conveyance belt 8 at the time when jamming is cleared, and to suppress generation of scratches on the photosensitive drum 3 and a surface of the conveyance belt 8.

Abstract: [Object]The object of this invention is to prevent as much as possible the occurrence of uneven image density produced by photoreceptors, in which uneven electrification and uneven sensitivity coexist, without enlargement of an apparatus as well as increase in cost. [Solution] For each of segments of the surface of the photoreceptor, individually memorizing a slope information K1 which defines the slope of when a pixel gradation is approximately linear-transformed into exposure amount, and then, based upon K1 per segment, individually transforming the pixel gradation into the exposure amount (individual exposure amount transformation).