Patent ID: 8744613

Claim:
A sheet processing apparatus comprising: a stacking control unit configured to control stacking of a small sheet, which has a small size, on one of a plurality of stacking units, including a first stacking unit, a second stacking unit, a third stacking unit, and a fourth stacking unit, and stacking of a large sheet, which has a larger size than the small sheet, on the first stacking unit and the fourth stacking unit, which is adjacent to first stacking unit, or the second stacking unit and the third stacking unit, which is adjacent to the second stacking unit, among the plurality of stacking units, so that the large sheet is set across the first stacking unit and the fourth stacking unit, or the second stacking unit and the third stacking unit; a determination unit configured to, in a case where a first sheet, which is a small sheet with the small size, is stacked on the first stacking unit, and a second sheet, which is also a small sheet with the small size, is designated to be stacked on the second stacking unit, determine whether or not any sheet is stacked on the third stacking unit, which is adjacent to the second stacking unit; and a control unit configured to select the fourth stacking unit, which is adjacent to the first stacking unit, for the second sheet, in a case where the determination unit determines that no sheet is stacked on the third stacking unit.