Patent ID: 7248829

Claim:
A sheet output apparatus comprising: a sheet set generating unit which generates a set of sheets by stapling a plurality of sheets stacked on a predetermined loading surface; an information obtaining unit which obtains image forming information showing that an image is formed on any one of a front side of each sheet, a backside opposite to the front side, and both sides with respect to each of the plurality of sheets constituting the set of sheets generated by the sheet set generating unit; a decision unit which decides whether a pair of sheets including two sheets in which the formed images face each other exists or not in the plurality of sheets constituting the set of sheets generated by the sheet set generating unit based on the image forming information obtained by the information obtaining unit; an output unit which comes into contact with at least one of the uppermost sheet and the lowermost sheet in the set of sheets generated by the sheet set generating unit to apply a force outputting the set of sheets in a predetermined output direction to the sheet, the output unit outputting the set of sheets in the output direction by one of a predetermined first output force and a second output force smaller than the first output force; and a control unit which controls the output unit to output the set of sheets by the first output force when the decision result by the decision unit shows that the pair of sheets does not exist in the plurality of sheets constituting the set of sheets, the control unit controlling the output unit to output the set of sheets by the second output force when the decision result by the decision unit shows that the pair of sheets exists in the plurality of sheets constituting the set of sheets.