Patent ID: 7414764

Claim:
A duplex/simplex automatic sheet feeder having a simplex feeding mode and a duplex feeding mode, and comprising: a sheet input tray in which a plurality of sheets to be fed is placed; a sheet output tray in which the sheets are placed after being fed; a first sheet-feeding path communicating with the sheet input tray and being formed with a first image processing region; a temporary storage region that may communicate with the first sheet-feeding path; a first sheet-feeding mechanism for feeding one of the sheets in the sheet input tray through the first sheet-feeding path and then to the temporary storage region; a second sheet-feeding path that may communicate with the temporary storage region and is formed with a second image processing region located at a predetermined distance from the first image processing region; and a second sheet-feeding mechanism for feeding the sheet in the temporary storage region through the second sheet-feeding path and then to the sheet output tray in the duplex feeding mode, wherein the temporary storage region and the first sheet-feeding mechanism are configured such that: in the simplex feeding mode the sheet from the first sheet-feeding path is transferred to the sheet output tray through the temporary storage region; and in both the duplex and the simplex feeding modes the sheets in the sheet output tray are arranged in the same order as in the sheet input tray.