Abstract: A sheet processing apparatus includes a conveyance roller pair that rotates in a certain direction to convey a sheet, a first normal-reverse rotation roller pair that is capable of rotating in a normal direction and a reverse direction and rotates to convey the sheet, a first driver that drives the first normal-reverse rotation roller pair to rotate, and a first driving force transmitter that transmits a driving force of the first driver for rotating the first normal-reverse rotation roller pair in a first specific direction to the conveyance roller pair so as to rotate the conveyance roller pair in the certain direction, and blocks a driving force of the first driver for rotating the first normal-reverse rotation roller pair in the direction opposite to the first specific direction from being transmitted to the conveyance roller pair.

Abstract: A sheet processing apparatus includes a conveyance roller pair that rotates in a certain direction to convey a sheet, a first normal-reverse rotation roller pair that is capable of rotating in a normal direction and a reverse direction and rotates to convey the sheet, a first driver that drives the first normal-reverse rotation roller pair to rotate, and a first driving force transmitter that transmits a driving force of the first driver for rotating the first normal-reverse rotation roller pair in a first specific direction to the conveyance roller pair so as to rotate the conveyance roller pair in the certain direction, and blocks a driving force of the first driver for rotating the first normal-reverse rotation roller pair in the direction opposite to the first specific direction from being transmitted to the conveyance roller pair.

Abstract: A paper processing apparatus includes: a discharging unit that discharges the paper onto a staple tray; a paper returning unit that reverses the paper discharged by the discharging unit and performs alignment in a conveying direction by abutting the paper against a rear end reference fence; a supporting unit that supports the discharging unit in a state capable of coming in contact with or separating from the paper; a contact and separation unit by which the discharging unit comes in contact with or separates from the paper; and a pressurizing unit that is moved by the contact and separation unit, does not load the discharging unit in a standby state where the discharging unit is held apart from the paper, and applies contact pressure in a state where the discharging unit is in contact with the paper.

Abstract: A sheet processing apparatus includes: a staple tray on which sheets are stacked temporarily and stapled after being aligned together and from which the stapled sheets are discharged to a discharge tray; a discharger to discharge the sheets to the staple tray; a rear end reference against which rear ends of the sheets are abutted to be aligned together; a returner to return the sheets discharged by the discharger and to align the sheets together in a conveying direction based on the rear end reference fence; a lifter to lift and lower the returner with respect to a sheet; and a guide configured to guide the sheets toward the rear end reference fence when the sheets are returned and to be lifted and lowered in synchronization with the lifting and lowering by the lifter.

Abstract: A paper processing apparatus includes: a discharging unit that discharges the paper onto a staple tray; a paper returning unit that reverses the paper discharged by the discharging unit and performs alignment in a conveying direction by abutting the paper against a rear end reference fence; a supporting unit that supports the discharging unit in a state capable of coming in contact with or separating from the paper; a contact and separation unit by which the discharging unit comes in contact with or separates from the paper; and a pressurizing unit that is moved by the contact and separation unit, does not load the discharging unit in a standby state where the discharging unit is held apart from the paper, and applies contact pressure in a state where the discharging unit is in contact with the paper.

Abstract: A sheet processing apparatus includes: a staple tray on which sheets are stacked temporarily and stapled after being aligned together and from which the stapled sheets are discharged to a discharge tray; a discharger to discharge the sheets to the staple tray; a rear end reference against which rear ends of the sheets are abutted to be aligned together; a returner to return the sheets discharged by the discharger and to align the sheets together in a conveying direction based on the rear end reference fence; a lifter to lift and lower the returner with respect to a sheet; and a guide configured to guide the sheets toward the rear end reference fence when the sheets are returned and to be lifted and lowered in synchronization with the lifting and lowering by the lifter.