Sheet processing apparatus, image forming system, and method of additionally folding sheet bundle

摘要

A sheet processing apparatus includes a pressing unit (260) including a first pressing member (261a) and a second pressing member (262a). The pressing unit (260) is configured to sandwich and press a fold part of a folded sheet bundle (SB) between the first pressing member (261a) and the second pressing member (262a). The sheet processing apparatus also includes a moving unit configured to move a position pressed by the pressing unit (260) in a direction of a fold of the sheet bundle (SB). A position pressed by the first pressing member (261a) on the sheet bundle (SB) and another position pressed by the second pressing member (262a) on the sheet bundle (SB) are shifted with respect to each other in the direction of the fold of the sheet bundle (SB).