Sheet processing device and sheet processing method

An apparatus for binding together side surfaces of a plurality of sheets, comprising;

• a sheet storage tray for receiving a plurality of sheets thereon;
• a stop positionable at a first position preventing movement of a plurality of sheets located on the sheet storage tray and a second position allowing movement of the plurality of sheets from the sheet storage tray;
• a first roller having a first axis of rotation and a second roller having a second axis of rotations;
• a movement unit operatively coupled to at least one of the first and second rollers so as to control the first and second rollers to be spaced from each other by different distances;
• a tape binding unit;
• a path selector located between the first and second rollers, wherein the path selector is movable to select a first path for the plurality of sheets that are conveyed off the sheet storage tray in a direction apart from the first and second rollers, and a second path for the plurality of sheets that are conveyed off the sheet storage tray toward the tape binding unit, wherein,
• the first and second rollers comprise outer surfaces, and the outer surface of the second roller is more compliant than the outer surface of the first roller, and
• the movement unit controls the first and second rollers to be spaced from each other by a first distance at which the plurality of sheets are located between the outer surfaces of the first and second rollers and the plurality of sheets extend inwardly of an indentation formed in the outer surface of the second roller, and by a second distance at which the plurality of sheets are located between the first and second rollers and the indentation is not formed in the outer surface of the second roller.