Patent ID: 8902270
Filing Date: 2014-12-02
Classification: G03G

Abstract:
1. An image forming apparatus comprising: an image forming unit which exposes a photoreceptor using a polygon mirror and transfers an image obtained by developing an electrostatic latent image formed on the photoreceptor to paper through a carrier; and a control unit which changes a rotation speed of the polygon mirror at an intermediate area on the carrier to change a reduction/magnification ratio of an image to be formed, wherein when a patch image is formed in the intermediate area, the control unit changes the rotation speed of the polygon mirror in a stepwise manner in such a way that the change of the rotation speed in each step is within a range to allow a stable rotation of the polygon mirror; and controls the image forming unit to form a corrected patch image in parallel with the stepwise change of the rotation speed, the corrected patch image being obtained through correction of an original patch image in accordance with the stepwise change of the rotation speed to be the same as a patch image formed when the rotation speed is not changed.