Sheet sorting apparatus and image forming apparatus

An image forming apparatus comprising:

• an image forming unit configured to form an image on a sheet;
• a conveyance guide having a branch point and configured to guide the sheet conveyed from the image forming unit;
• a first discharge roller configured to discharge a sheet conveyed along the conveyance guide through a first discharge port;
• a second discharge roller configured to discharge a sheet conveyed from the branch point of the conveyance guide thorough a second discharge port;
• a first discharge tray, provided at a position corresponding to the first discharge port, for stacking the sheet discharged by the first discharge roller, wherein the first discharge tray is detachable from a main body of the image forming apparatus;
• a second discharge tray, provided at a position corresponding to the second discharge port and arranged below the first discharge tray, for stacking the sheet discharged by the first discharge roller or the sheet discharged the second discharge roller;
• a switch member configured to be moved between a position where a sheet is guided toward the first discharge port and a position where a sheet is guided toward the second discharge port;
• and
• a controller configured to control an execution of a job for forming images on sheets based on print data in which a sorting destination of the sheets is designated by a user,
• wherein, when the first discharge tray has been detached and the sorting destination corresponds to the second discharge tray, the controller moves the switch member so that the sheets of the job are discharged from the first discharge port to the second discharge tray, and, in response to the first discharge tray being attached during the execution of the job, the controller moves the switch member so that remaining sheets of the job are discharged from the second discharge port to the second discharge tray.