| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of efficiently and accurately correcting image magnification at the time of both-side printing. <P>SOLUTION: The image forming apparatus is provided with: an image carrier carrying an electrostatic latent image; an exposure means exposing the image carrier; a means changing the image magnification of both surfaces at the time of both-side printing; a means arranged on the upstream side of a transfer section and detecting recording paper size; and a means calculating an image magnification correction value, on the basis of the expansion and contraction rate of the recording paper size of both surfaces in both-side printing detected by the detecting means. In the image forming apparatus, during a print job, when the image magnification correction value is not obtained since the recording paper size of the second surface is not detected yet, the exposure to the image carrier is stopped until the image magnification correction value is calculated and is resumed according to that the image magnification correction value is calculated, meanwhile, a recording paper to which an image for the first surface is transferred is stopped on the upstream of the transfer section and conveyance of the recording paper is started after the prescribed timing from the calculation of the image magnification correction value, to transfer the image for the second surface to the recording paper in the transfer section. <P>COPYRIGHT: (C)2007,JPO&INPIT |
