Image forming apparatus

An image forming apparatus, comprising:

• a main casing including an image forming unit and a discharge tray;
• and
• an optional device configured to be removably attached to the main casing,
• wherein the main casing includes:
• a conveying path through which a sheet is conveyed from the image forming unit;
• a discharge path through which the sheet is conveyed toward one of the discharge tray in a discharge direction and the optional device, the discharge path diverging from the conveying path;
• and
• a return path including a first path through which the sheet is conveyed temporarily out of the main casing via an opening formed in the main casing, and a second path through which the sheet is conveyed toward the image forming unit, the first path diverging from the conveying path, the second path diverging from the first path, and
• wherein the optional device is disposed downstream to the opening in the discharge direction;
• and
• wherein the image forming apparatus further comprises:
• a cover configured, when the optional device is removed from the main casing, to selectively change between a first state in which the cover covers the opening and a second state in which the cover uncovers the opening and the optional device is attachable;
• and
• a pivot shaft that supports the cover to allow the cover to pivotally move between the first state and the second state, and
• wherein the cover in the first state defines a guide surface configured to guide the sheet conveyed through the first path to a position above the discharge tray.

An image forming apparatus, comprising:

• a main casing including an image forming unit and a discharge tray;
• and
• an optional device including a roller configured to convey a sheet conveyed from the main casing through an optional path in the optional device, the optional device being configured to be removably attached to the main casing, the optional device having a first side and a second side that is opposite from the first side, the first side extending in a first direction,
• wherein the main casing includes:
• a conveying path through which a sheet is conveyed from the image forming unit;
• a discharge roller configured to discharge a sheet in a discharge direction toward the discharge tray;
• a discharge path including a first discharge path through which the sheet is conveyed toward the discharge tray, and a second discharge path through which the sheet is conveyed toward the optional device via a first opening formed in the main casing, the discharge path diverging from the conveying path;
• and
• a return path including a first path through which the sheet is conveyed temporarily out of the main casing and the optional device and along the first side of the optional device in the first direction via a second opening formed in the main casing, and a second path through which the sheet is conveyed toward the image forming unit,
• the first path diverging from the conveying path, the second path diverging from the first path, and
• wherein when the optional device is removably attached to the main casing, the optional device is disposed downstream to the second opening in the discharge direction and includes an optional discharge tray that extends from the second side.