An image forming apparatus includes an image forming unit configured to form an image on a sheet, a duplex conveyance path through which the sheet having the image formed by the image forming unit on a first side passes when an image is formed on a second side that is a back side of the first side, a guiding member provided along the duplex conveyance path, a reversing roller pair capable of rotating in a forward direction and in a reverse direction, h, and a conveyance roller pair provided on the duplex conveyance path, wherein at least one of the reversing roller pair is inclined to the width direction so that, in the width direction, the side end of the sheet being conveyed by the reversing roller pair rotating in the reverse direction moves closer to the contact portion.

Provided is the sheet bundle transport apparatus including: an abutment unit that performs switching between an abutment state at a predetermined position and a non-abutment state; first and second press units that press the sheet bundle against first and second transport units; a press switching unit that performs switching between a first press state where the first and second press units press the sheet bundle in a predetermined region located upstream from the predetermined position in the transport direction and a second press state where the first press unit does not press the sheet bundle in the predetermined region; and a control unit that controls the abutment unit and the press switching unit to switch the non-abutment state to the abutment state and switch the first press state to the second press state so as to change an angle relative to the width direction of a predetermined sheet bundle.

A guide mechanism including a guide that regulates a position of a paper sheet stacked includes a power transmitter that moves the guide to three or more positions by means of power obtained from a separate mechanism, which is different from the guide mechanism, and a switching drive that switches the power transmitter between a transmission state in which the power of the separate mechanism is transmitted to the guide and a non-transmission state in which the power of the separate mechanism is not transmitted.