The shift jogger fences wait at the home position (above the paper exit of the finisher shift tray), and then they are lowered just before the finisher discharges the paper. After the paper is discharged, the shift jogger fences align the side edges of the paper. After the discharge of the copy sets is finished, the shift jogger fences are raised in order to return to its home position. The shift jogger fences are lowered/raised whenever the finisher discharges the copy sets.