Image forming apparatus

An image forming apparatus comprising:

• an image forming unit configured to form a toner image;
• a transfer unit configured to transfer the toner image formed by the image forming unit in a transfer portion;
• a fixing unit configured to perform a fixing process to an unfixed toner image on a recording material;
• a first rotatable member configured to convey the recording material to the image forming unit in a conveyance direction as a first direction;
• a second rotatable member provided downstream of the fixing unit in the first direction;
• a driving source configured to drive the fixing unit and the second rotatable member;
• a detecting unit provided between the first rotatable member and the second rotatable member and configured to detect a leading end and a trailing end of the recording material;
• and
• a control unit configured to (1) determine an actual length of the recording material in the first direction based on a detection result of the detecting unit and (2) switch between a first control in which the second rotatable member is controlled so as to convey the recording material in the first direction and a second control in which the second rotatable member is controlled so as to convey the recording material in a second direction opposite to the first direction,
• wherein in performing a double-side printing in which an image is formed on a first side and a second side different from the first side of the recording material, the control unit is capable of conveying the recording material to the transfer portion again by switching the second rotatable member from the first control to the second control and conveying the recording material to a double-side conveyance path, and
• wherein the control unit performs a reciprocating control in which the first control and the second control are alternately switched at least one time when the recording material is being conveyed in the double-side conveyance path based on a determination by the control unit that the actual length of the recording material which is determined is shorter than a length of the recording material in the conveyance direction reserved in a print start.