Abstract: A sheet feeding apparatus includes a carrier portion, a suction belt, a servo motor, a blower, a solenoid valve, a pressure sensor, a position sensor, a belt hole sensor, and a controller. The carrier portion feeds a plurality of sheets of different sizes in a direction of their thickness in an upright state. The suction belt has a belt hole for drawing each sheet fed from the carrier portion by suction, so as to feed out each sheet drawn by suction with the belt hole. The servo motor drives the suction belt. The blower generates a pressure for drawing the sheet by suction in the belt hole. The solenoid valve enables/disconnects supply of the negative pressure from the blower to the belt hole. The pressure sensor measures a pressure in the belt hole. The position sensor detects the sheet fed out by the suction belt. The belt hole sensor detects the belt hole after the sheet is fed out.

Abstract: A sheet feed mechanism includes first, second, and third feed rollers, first and second servo motors, a reverse roller, a torque limiter, a pick-up roller, and a plurality of photoelectric sensors. The first, second, and third feed rollers are respectively mounted on a feed path of sheets including mail pieces, on an upstream side of the first feed roller in the feed direction, and on the upstream side of the second feed roller in the feed direction, and are respectively rotated by the one-way clutches in only a feed direction. The first and second servo motors respectively drive the first and second feed rollers, and the second feed roller independently. The reverse roller is pressed against by the first feed roller through the feed path, and is driven to rotate in a counter feed direction. The torque limiter constantly applies a predetermined driving torque to the reverse roller in the counter feed direction.