Patent ID: 8532515
Filing Date: 2013-09-10
Classification: G03G

Abstract:
1. An image forming apparatus comprising: a photosensitive member; a charging unit for electrically charging a surface of said photosensitive member; an exposure unit for forming an electrostatic latent image by exposing the charged surface of said photosensitive member to light; a developing unit for developing the formed electrostatic latent image into a toner image; a rotatable endless intermediary transfer belt; a primary transfer member for primary-transferring the toner image from said photosensitive member onto said intermediary transfer belt at a primary transfer position; a secondary transfer member for secondary-transferring the toner image, primary-transferred on said intermediary transfer belt, onto a transfer material at a secondary transfer position, wherein said image forming apparatus is operable in a mode in which a speed of said intermediary transfer belt is changed after all of the toner images are primary-transferred onto said intermediary transfer belt, and the toner image primary-transferred on said intermediary transfer belt is passed through the secondary transfer position and the primary transfer position in this order to reach the secondary transfer position, where the toner image is secondary-transferred onto the transfer material; and a controller for making, before said image forming apparatus is operated in the mode to change the speed of said intermediary transfer belt, a potential difference between said intermediary transfer belt and said photosensitive member at the primary transfer position smaller than a potential difference between said intermediary transfer belt and said photosensitive member when the toner image is primary-transferred from said photosensitive member onto said intermediary transfer belt.