When the machine applies a corner staple to a paper stack, the other end of the stack is hanging out of the exit. At this time, to prevent the paper stack from dropping to the upper tray, the edge guide [D] comes out of the unit. The edge guide operates in the following way:

  1. When a job starts, the upper tray guide plate [A] shifts up.
  2. The edge guide motor [B] turns on to push the edge guide [D] out. The edge guide retreats to the machine when the last sheet of a job is output (the edge guide HP sensor [C] detects the edge guide).