41 the reverse conveyor path 41 reverses and guides paper sheets p in a direction toward the secondary transfer roller 25 the reverse conveyor path 41 is used when carrying out double sided printing operation of the image forming apparatus shown in fig1 and 2 will be described next as image forming is started image information is inputted from a scanner personal computer terminal or the like then photosensitive drums 12 rotate and the image forming sections 2 y to 2 k sequentially form images referring to the image forming section 2 y as an example the photosensitive drum 12 y is irradiated with a laser beam in accordance with image information for yellow y thereby forming an electrostatic latent image from the electrostatic latent image a toner image for yellow y is formed by the developing device 14 y subsequently the photosensitive drum 12 y makes contact with the intermediate transfer belt 11 being rotated thereby primarily transferring the toner image for yellow y to the intermediate transfer belt 11 by the primary transfer roller 15 y in a similar manner to the toner image forming process for yellow y toner images for magenta m cyan c and black k are formed by the image forming section 2 m 2 c and 2 k and are sequentially transferred to the same position on the intermediate transfer belt 11 as the toner image for yellow y has been formed thus toner images for yellow y magenta m cyan c and black k are transferred to the intermediate transfer belt 11 multi layered on one another so that a full color toner image is obtained further the intermediate transfer belt 11 secondarily transfers the.