Image forming apparatus that can form images on both sides of sheet by inverting sheet

An image forming apparatus comprising:

• a main conveyance path configured to convey a sheet;
• an image forming unit configured to form images on a first surface and a second surface of the sheet to be conveyed on the main conveyance path;
• a switchback unit provided at an end portion of the main conveyance path and configured to switch back the sheet having the image formed on the first surface by a roller pair;
• a sub conveyance path configured to convey the switched back sheet to the main conveyance path in order to form the image on the second surface of the sheet;
• a motor configured to be controlled to drive the roller pair provided in the switchback unit and to rotate in only one direction;
• a transmission unit configured to transmit a driving force to be supplied from the motor to the roller pair;
• a switching unit configured to act on the transmission unit to switch a rotation direction of the roller pair by the driving force between a normal rotation and a reverse rotation;
• and
• a control unit configured to control a rotation speed of the motor to convey the sheet, wherein the sheet having the image formed on the first surface by the image forming unit is conveyed in a first direction by the roller pair in a first time period, and the sheet is conveyed in a second direction different from the first direction by the roller pair in a second time period, the control unit changes the rotation speed from a first rotation speed to a second conveyance speed so that the sheet is conveyed at the second rotation speed in a part of the first time period, the second conveyance speed is lower than the first conveyance speed, and the first conveyance speed is a conveyance speed at which the sheet is conveyed in the image forming unit.