IMAGE FORMING APPARATUS AND IMAGE FORMING METHOD

PROBLEM TO BE SOLVED: To provide a four-cycle type image forming apparatus which does not cause faulty transfer or blur and by which a high-quality transfer image is obtained, and to provide an image forming method. SOLUTION: The image forming apparatus is equipped with a photoreceptor drum 2, a multicolor developing unit 4, the intermediate transfer belt 5 circulating while a plurality of toner images 21 to 24 are successively intermediately transferred thereto, a 1st laying roll 7 and a 2nd laying roll 8 making the intermediate transfer belt 5 circulate oppositely to slide in contact with the photoreceptor drum 2 on their outer peripheries, an intermediate transfer roll 6 arranged to come into contact with the intermediate transfer belt 5 on an opposite side to the photoreceptor drum 2 while putting the intermediate transfer belt 5 in between and also generating transfer electric field between the photoreceptor drum 2 and the intermediate transfer roll 6, and a circular-arc angle changing means capable of changing circular-arc angles θ1 to θ4 formed by a contact part between the photoreceptor drum 2 and the intermediate transfer belt 5 with the center of the photoreceptor drum 2. COPYRIGHT: (C)2006,JPO&NCIPI