Sheet processing apparatus

A sheet processing method comprising:

• moving up and moving down a paper discharge tray to stack sheets discharged from a discharge port;
• arranging a sheet member below the discharge port configured to move up and move down in association with the paper discharge tray;
• supporting an edge toward the discharge port side of the sheet stacked on the paper discharge tray with the sheet member;
• and
• ascending a support portion for the sheet of the sheet member in an upward direction in association with the paper discharge tray if the paper discharge tray moves up and descending the support portion for the sheet in a downward direction in association with the paper discharge tray if the paper discharge tray moves down.

A sheet processing apparatus comprising:

• moving means for moving up and moving down a paper discharge tray in order to stack a sheet discharged from a discharge port on the paper discharge tray;
• wherein the moving means further comprising supporting means configured to:
• move up and move down in association with movement of the paper discharge tray, and
• supporting an edge of the sheet stacked on the paper discharge tray, the edge being supported toward the discharge port side of the paper discharge tray;
• and
• driving means for moving the supporting means in association with the paper discharge tray in an upward direction in the event of the paper discharge tray moving up and moving the supporting means in association with the paper discharge tray support portion in a downward direction in the event of the paper discharge tray moving down.