Sheet processing apparatus and image forming system

An image forming system comprising:

• an image forming unit configured to form an image on a sheet;
• a pair of conveyance rollers configured to convey the sheet in a conveyance direction;
• a tray on which the sheet conveyed by the pair of conveyance rollers is placed;
• a sheet dropping portion configured to drop a sheet onto the tray by moving between a receiving position where the sheet conveyed toward the tray by the pair of conveyance rollers is received and a dropping position where the sheet dropping portion is located below the receiving position in a vertical direction;
• an abutment portion against which an upstream end in the conveyance direction of the sheet placed on the tray abuts;
• a conveyance portion configured to convey the sheet on the tray toward the abutment portion in a state where the sheet dropping portion is located at the dropping position;
• a guide portion configured to guide the sheet toward the abutment portion when the sheet conveyed by the conveyance portion comes into contact with the guide portion;
• and
• a stapler configured to bind a plurality of the sheets abutted against the abutment portion;
• wherein the sheet dropping portion includes a guide surface configured to guide the sheet toward the guide portion when the sheet conveyed by the conveyance portion comes into contact with the guide surface of the sheet dropping portion located at the dropping position, and
• wherein the guide surface overlaps a part of the guide portion when viewed in a rotational axis direction of the pair of conveyance rollers.