Patent ID: 7697883

Claim:
A sheet processing apparatus comprising: a sheet stacking portion on which sheets are stacked; a conveying portion which conveys a sheet onto the sheet stacking portion; a reference wall against which an upstream end in a sheet conveying direction of the sheet, conveyed onto the sheet stacking portion, is abutted; a first restriction member which has a first lower face crossing the reference wall, the first lower face preventing lift of an upstream end portion of the sheet stacked on the sheet stacking portion; and a second restriction member which has a second lower face located downstream of the reference wall, the second lower face prevents lift of the upstream end portion of the sheet stacked on the sheet stacking portion, wherein the first restriction member and the second restriction member are each moveable by a pushing force of a sheet being conveyed, between a restricting position in which lift of the upstream end portion of the sheet stacked on the sheet stacking portion is prevented and a retracting position to which each restriction member is retracted from the restricting position, and wherein the second restriction member moves from the restricting position to the retracting position after the first restriction member moves from the restricting position to the retracting position as the sheet is introduced to the sheet stacking portion, the first restriction member moves from the retracting position to the restricting position as the sheet passes, the second restriction member then moves from the retracting position to the restricting position.