IMAGE FORMING APPARATUS AND PROGRAM

PROBLEM TO BE SOLVED: To provide an image forming apparatus that hardly causes a difference in size between an image formed on a first face and an image formed on a second face of a recording material even when images are formed on both of the first face and the second face of the recording material.SOLUTION: The image forming apparatus includes: toner image forming means forming a toner image; a transfer device 15 transferring the toner image onto a sheet by using a photoreceptor drum 11; a fixing unit 20 fixing the toner image to the sheet; a sheet inverting mechanism 40 inverting the sheet from a first face to a second face of the sheet after the toner image is fixed to the first face of the sheet by the fixing unit 20, and again supplying the sheet to the transfer device 15; a control unit 500 controlling the rotational speed of the photoreceptor drum 11. The control unit 500 adjusts the magnification of a toner image in a sub-scanning direction by decreasing the rotational speed of the photoreceptor drum 1 upon transferring a toner image on the second face of the sheet than the rotational speed of the photoreceptor drum 11 during transferring a toner image on the first face of the sheet.