Patent ID: 7731187

Claim:
A method of operating a sheet medium adjustment apparatus, the method comprising: ejecting a conveyed sheet of a printable medium; stacking the ejected sheet into a stack on a tray; shifting a stack that includes the stacked sheet in a movement direction perpendicular to a sheet-ejecting direction; aligning, via an aligning member, ends of the sheets in the stack that are parallel to the sheet-ejecting direction; evacuating the aligning member by an amount representing an evacuation displacement in the movement direction at a timing of aligning the sheet; and determining the evacuation displacement adaptively according to at least one of an attribute of a given sheet in the stack, an attribute of the stack as a whole and an attribute of the tray, wherein the evacuating displacement is determined as a percentage of a maximum evacuating displacement, wherein the attribute of the stack is the number of sheets in the stack, and when the number of sheets in the stack is fewer than 3, the evacuation displacement is set to a first percentage (P 1 ) of the maximum evacuation displacement, when the number of sheets in the stack is between 3 and 4, the evacuation displacement is set to a second percentage (P 2 ) of the maximum evacuation displacement, where P 2 >P 1 , and when the number of sheets in the stack exceeds 4, the evacuation displacement is set to the maximum evacuation displacement.