Sheet processing apparatus and image forming system

A sheet processing apparatus comprising:

• a first conveyance portion including a pair of conveyance rollers configured to convey a sheet in a first conveyance direction;
• a placement portion on which the sheet conveyed by the first conveyance portion is placed;
• a sheet dropping portion including a pivot center, provided to extend upstream in the first conveyance direction from the pivot center, capable of pivoting about the pivot center to an upper position and a lower position in a case where the sheet is conveyed by the first conveyance portion, and configured to drop the sheet conveyed by the first conveyance portion onto the placement portion by moving from the upper position toward the lower position, the pivot center being provided downstream of the pair of conveyance rollers in the first conveyance direction, the upper position being a position where the sheet dropping portion allows the sheet to drop onto the placement portion, the lower position being a position below the upper position in a vertical direction;
• an abutment portion against which an upstream end in the first conveyance direction of the sheet placed on the placement portion is caused to abut;
• a second conveyance portion configured to convey the sheet conveyed by the first conveyance portion, in a second direction toward the abutment portion;
• a stapler configured to perform a binding process by using a staple on a sheet bundle constituted by a plurality of sheets abutting against the abutment portion;
• a stapleless binding unit including a sheet receiving portion and configured to perform a binding process without using a staple on the sheet bundle placed on the placement portion and received by the sheet receiving portion, the sheet receiving portion being configured to receive the sheet conveyed by the second conveyance portion;
• and
• a guiding portion provided on the sheet dropping portion and configured to pass the sheet, whose conveyance by the second conveyance portion has been started, onto the sheet receiving portion in a case where the sheet abuts against the guiding portion in a state in which the sheet dropping portion is at a guiding position below the upper position, the guiding portion being disposed at a position that is positioned downstream of a nipping point of the pair of conveyance rollers in the second conveyance direction and below the nipping point in the vertical direction in the state in which the sheet dropping portion is at the guiding position.