Sheet post-processing device

A sheet post-processing device, comprising:

• a folding portion that applies a predetermined folding process to a sheet;
• a discharge portion that discharges the sheet through a sheet discharge port;
• a stacking tray on which the sheet discharged through the sheet discharge port is stacked;
• a shift unit that shifts a discharge position of the sheet on the stacking tray in a sheet width direction orthogonal to a discharge direction;
• a pair of alignment members including
• a first alignment member disposed at one side in the sheet width direction so as to be reciprocatable in the sheet width direction and
• a second alignment member disposed at another side in the sheet width direction so as to be reciprocatable in the sheet width direction,
• the pair of alignment members configured to contact the sheet stacked on the stacking tray to align a position of the sheet in the sheet width direction;
• and
• a controller that controls the folding portion, the shift unit, and the pair of alignment members,
• wherein
• the controller performs
• an alignment process in which the controller makes the pair of alignment members reciprocate between a predetermined aligning position and a position outward of the aligning position with respect to the sheet width direction, thereby to align the sheet discharged at a predetermined discharge position on the stacking tray and
• a sorting process in which the controller, when a plurality of copies of sheet bundles each including a plurality of the sheets are discharged, drives the shift unit to shift the discharge position of the sheet bundles discharged on the stacking tray alternately, between a first shift position at one side in the sheet width direction and a second shift position at another side in the sheet width direction,
• in the sorting process,
• the alignment process is performed in a state where the first alignment member disposed at a first position corresponding to the first shift position and the second alignment member disposed at a second position corresponding to the second shift position,
• when the sheet bundle stacked on the stacking tray does not include the sheet subjected the folding process, executes a first alignment mode in which the alignment process is performed with the first and second alignment members,
• when the sheet bundles stacked on the stacking tray includes the sheet subjected the folding process,
• executes a second alignment mode in which,
• for the sheet bundle shifted to the first shift position, the alignment process is performed with only the first alignment member and
• for the sheet bundle shifted to the second shift position, the alignment process is performed with only the second alignment member, or
• does not perform the alignment process.