Image forming apparatus

An image forming apparatus comprising:

• an image forming unit configured to form an image on a sheet;
• a first discharge tray onto which the sheet on which the image is formed by the image forming unit is discharged through a first conveyance path;
• a first branched path branched from the first conveyance path;
• a second branched path branched from the first conveyance path on an upstream side of the first branched path;
• a reverse conveying roller which is provided in the second branched path and configured to convey the sheet on which the image is formed on a first surface of the sheet by the image forming unit, in a first direction and a second direction opposite to the first direction so as to reverse a front surface and a back surface of the sheet;
• a discharge unit configured to be removably mounted to a mounting portion provided in the image forming apparatus, the discharge unit including:
• a reverse conveying path, which is to be connected to the second branched path in a case in which the discharge unit is mounted to the mounting portion, and through which the sheet is conveyed by a conveying force applied by the reverse conveying roller without having a drive portion for applying a conveying force to the sheet to be conveyed by the reverse conveying roller;
• an openable and closable member configured to open and close the reverse conveying path;
• an open/close sensor configured to detect opening and closing of the openable and closable member;
• a second conveyance path which is to be connected to the first branched path in the case in which the discharge unit is mounted to the mounting portion;
• a second discharge tray;
• a sheet conveyance unit which is provided in the second conveyance path and configured to convey the sheet so as to discharge the sheet to the second discharge tray;
• and
• a failure detector configured to detect a failure of the sheet conveyance unit;
• and
• a controller,
• wherein in a case in which the controller determines that the sheet conveyance unit is in failure based on a detection result of the failure detector and determines that the openable and closable member is closed based on a detection result of the open/close sensor, the controller prohibits discharge of the sheet to the second discharge tray and permits conveyance of the sheet to the reverse conveying path, and
• wherein in a case in which the controller determines that the sheet conveyance unit is in failure and determines that the openable and closable member is open based on the detection result of the open/close sensor, the controller prohibits the conveyance of the sheet to the reverse conveying path.