Patent ID: 7584950

Claim:
An image forming apparatus comprising: a print part; a feeding part; a first sheet feeding tray which stores a first sheet having a first size therein, the feeding part feeding the first sheet from the first sheet feeding tray to the print part in a sheet feeding direction; a second sheet feeding tray which is mounted on the first sheet feeding tray and which stores a second sheet having a second size smaller than the first size therein, the feeding part feeding the second sheet from the second sheet feeding tray to the print part in the sheet feeding direction, the second sheet feeding tray receiving a printed sheet printed by the print part and discharged in a direction opposite to the sheet feeding direction, wherein the second sheet feeding tray is configured to selectively move between a first position and a second position, and the second sheet feeding tray covers a larger portion of the first sheet feeding tray when the second sheet feeding tray is at the first position than when the second sheet feeding tray is at the second position a first backward-feed prevention part which prevents the printed sheet from being fed to the print part again when the second sheet feeding tray is at the first position; and a second backward-feed prevention part which prevents the printed sheet from being fed to the print part again when the second sheet feeding tray is at the second position, wherein when the second sheet feeding tray is at the first position, the first sheet feeding tray is configured to place the first sheet in contact with the feeding part, to prevent the second sheet stored in the second sheet feeding tray from being fed by the feeding part, and when the second sheet feeding tray is at the second position, the second sheet feeding tray is configured to place the second sheet in contact with the feeding part, to prevent the first sheet stored in the first sheet feeding tray from being fed by the feeding part.