Abstract: An image forming apparatus includes an image bearing member for bearing a toner image, a transfer member for forming a transfer portion for transferring the toner image onto a recording material in contact with the image bearing member, a vibration imparting portion for imparting vibration at a variable frequency to the recording material having passed through the transfer portion, and a control portion for controlling the frequency by the vibration imparting portion so that the frequency is decreased with an increasing length of the recording material having passed through the transfer portion during a process of passing the recording material through the transfer portion.

Abstract: When a switch displayed on an operation panel is operated, a control portion starts aging control in which image formation is stopped and yellow toner is applied onto an intermediary transfer belt and a secondary transfer roller. A toner band is formed, on full circumference of the intermediary transfer belt at a position in which toner images for control are formed, with a width correspondingly to widths of the toner images for control.

Abstract: In an image forming apparatus, when backside contamination of a recording material occurs, a control portion carries out control so that a plurality of restoring toner bands having a length L1 longer than a circumference L3 of a secondary transfer roller is formed at an interval L2 at positions in which the restoring toner bands can overlap with control images with respect to a longitudinal direction of the secondary transfer roller and then is transferred onto the secondary transfer roller through an intermediary transfer belt. The restoring toner bands transferred onto the secondary transfer roller stagnate on a fur brush rubbing against the secondary transfer roller to remove an electric discharge product deposited on the secondary transfer roller. The toner stagnating on the fur brush is inverted in charge polarity and then is re-transferred onto the intermediary transfer belt through the secondary transfer roller.