Patent ID: 7530565

Claim:
An apparatus for processing printed sheets connected to an image forming apparatus, the apparatus for processing printed sheets comprising: a processing tray on which the sheets are aligned with one another in a width direction and a longitudinal direction to form a pile of sheets; a standby tray having a pair of tray members arranged away from each other in the width direction above the processing tray, the tray members being movable in the width direction, the tray members moving between a first position at which a sheet is placed on the tray members and a second position at which the sheet on the tray members is dropped onto the processing tray; a tray driving mechanism which moves the pair of tray members between the first and second positions in synchronism with each other, a roller mechanism placed near a rear end of the standby tray to feed the sheets from the image forming apparatus onto the standby tray; an assist arm which is movable in a vertical direction around an arm shaft placed near the roller mechanism, the assist arm rising in contact with the sheet being fed from the roller mechanism onto the standby tray, lowering when the sheet has been fed onto the standby tray, and pressing a rear end of the sheet toward the processing tray when the tray members move from the first position to the second position; a stapler placed behind the processing tray to staple the pile of sheets; and a paddle mechanism placed near the rear end of the standby tray, the paddle mechanism has a paddle member which rotates around a shaft, and the paddle member strikes the rear end of the sheet when the pair of tray members of the standby tray moves from the first position to the second position, the paddle member having: a short paddle which strikes the rear end of the sheet downward as the pair of tray members of the standby tray moves from the first position to the second position; and a long paddle which rubs the sheet on the processing tray toward the stapler.