Sheet postprocessing device that performs postprocessing on plurality of sheets stacked, and image forming system including same

A sheet postprocessing device comprising:

• a table that receives a sheet;
• a delivery roller that delivers the sheet to the table;
• a leading edge cursor provided on the table, and to which a leading edge of the sheet in a delivery direction in which the sheet is delivered, is abutted against;
• a stapling device that binds a central position in the delivery direction, of a plurality of the sheets stacked on the table;
• a center folding device that folds the sheets, the central position of which has been bound by the stapling device, at the central position;
• and
• a first pressing member located on an upper side of the table, and supported so as to pivot in a direction toward and away from the table, about an end portion on an upstream side in the delivery direction serving as a pivotal fulcrum,
• wherein the first pressing member makes contact with the sheet being delivered to the table, by pivoting toward the table, allows the leading edge of the sheet to pass toward the leading edge cursor, and holds the sheet at a position upstream of the leading edge cursor in the sheet delivery direction,
• wherein the sheet postprocessing device further comprising a pair of side-edge cursors, provided on the table, at respective sides with respect to the leading edge cursor in a width direction orthogonal to the delivery direction, and configured to receive the sheets delivered to the table, and align positions of respective side edges of the sheets with each other, by contacting the side edges of the sheets in the width direction,
• wherein the pair of side-edge cursors each include a bottom plate on which the sheet is placed, the bottom plate being oriented parallel to an upper face of the table, a side-edge plate erected along an outer edge of the bottom plate in the width direction, and configured to make contact with the side edge of the sheet, and a second pressing member provided along the side-edge plate on an upper side of the bottom plate, and supported so as to pivot in a direction toward and away from the bottom plate, about an end portion on an upstream side in the delivery direction serving as a pivotal fulcrum,
• the second pressing member is configured to pivot toward the bottom plate, allow the leading edge of the sheet delivered to the bottom plate to pass, and press the side edge of the sheet received between the pair of side-edge cursors, at a position upstream of the leading edge cursor in the delivery direction, and
• the pair of side-edge cursors are each located closer to a side edge of the table in the width direction, than is the first pressing member, and a first pressing position where the first pressing member presses the sheet, and a second pressing position where the second pressing member presses the sheet are shifted from each other, in the delivery direction.