A feeder includes: a mount board that moves vertically while allowing sheet-shaped media to be stacked thereon; a transport device that allows an uppermost one of the sheet-shaped media stacked on the mount board to be sucked by a suction portion to transport the uppermost sheet-shaped medium to a transporter and to feed the uppermost sheet-shaped medium to a destination; left and right edge air blowers that blow air to left and right edge portions, when viewed from an upstream side in a transportation direction, of upper ones of the sheet-shaped media stacked; and left and right detectors that are disposed on left and right sides of the suction portion at the same position in the transportation direction, and that individually detect downward or upward bend amounts of left and right edge portions of the uppermost sheet-shaped medium.

A sheet conveying device includes a sheet placement table, a sheet discharge table, a conveyance mechanism, raising/lowering mechanism, and a raising/lowering control portion. The sheet discharge table is located below the sheet placement table. The conveyance mechanism conveys a sheet placed on the sheet placement table onto the sheet discharge table via an execution position at which image processing is executed by an image processing portion. The raising/lowering mechanism raises and lowers the sheet placement table. The raising/lowering control portion controls the raising/lowering mechanism in accordance with a clearance that is defined by a height from the sheet on the sheet discharge table to the sheet placement table, so as to maintain the clearance to be equal to or higher than a set value.

A sheet conveying device includes a sheet placement table, a sheet discharge table, a conveyance mechanism, raising/lowering mechanism, and a raising/lowering control portion. The sheet discharge table is located below the sheet placement table. The conveyance mechanism conveys a sheet placed on the sheet placement table onto the sheet discharge table via an execution position at which image processing is executed by an image processing portion. The raising/lowering mechanism raises and lowers the sheet placement table. The raising/lowering control portion controls the raising/lowering mechanism in accordance with a clearance that is defined by a height from the sheet on the sheet discharge table to the sheet placement table, so as to maintain the clearance to be equal to or higher than a set value.

A rotation device rotates a sheet on an upstream side of, in a sheet conveyance orientation, a working device positioned in a middle of a conveyance path, thereby changing an orientation of the sheet. An information acquiring portion acquires sheet size information and sheet orientation information representing a size and the orientation of the sheet in a sheet storing portion, and working position information representing a working position on the sheet. A rotation control portion controls the rotation device in accordance with the sheet orientation information and the working position information. The working control portion controls the working device in accordance with the orientation of the sheet after passing through the rotation device, and the sheet size information and the working position information.

A rotation device rotates a sheet on an upstream side of, in a sheet conveyance orientation, a working device positioned in a middle of a conveyance path, thereby changing an orientation of the sheet. An information acquiring portion acquires sheet size information and sheet orientation information representing a size and the orientation of the sheet in a sheet storing portion, and working position information representing a working position on the sheet. A rotation control portion controls the rotation device in accordance with the sheet orientation information and the working position information. The working control portion controls the working device in accordance with the orientation of the sheet after passing through the rotation device, and the sheet size information and the working position information.

In an example, a method may include determining a range of motion of a pick arm during lifting of the pick arm from a media stack position to a hard stop position in an image forming apparatus. The pick arm may have a pick roller at one end for picking a media sheet from a media stack and pivotally mounted at an opposite end to enable angular movement of the pick arm relative to the media stack. Further, the method may include estimating a height of the media stack based on the determined range of motion of the pick arm from the media stack position to the hard stop position. Furthermore, the method may include indicating an amount of media sheets remaining in the media stack corresponding to the estimated height.

A sheet stacker includes a sheet stacking portion, a pair of sheet restrictors, a sheet feeder, and a position detector. A bundle of sheets is stacked on the sheet stacking portion in a stacking direction, and the sheet stacking portion moves in the stacking direction. The pair of sheet restrictors move in a width direction to regulate a position of the bundle of sheets in the width direction. The sheet feeder feeds a top sheet of the bundle of sheets at a sheet feeding position in a sheet feeding direction. The sheet feeding position is disposed at a top of the bundle of sheets in the stacking direction. The position detector is disposed between the pair of sheet restrictors in the width direction and above the sheet feeding position in the stacking direction. The position detector detects a position of the pair of sheet restrictors in the width direction.

A sheet stacker includes a sheet stacking portion, a pair of sheet restrictors, a sheet feeder, and a position detector. A bundle of sheets is stacked on the sheet stacking portion in a stacking direction, and the sheet stacking portion moves in the stacking direction. The pair of sheet restrictors move in a width direction to regulate a position of the bundle of sheets in the width direction. The sheet feeder feeds a top sheet of the bundle of sheets at a sheet feeding position in a sheet feeding direction. The sheet feeding position is disposed at a top of the bundle of sheets in the stacking direction. The position detector is disposed between the pair of sheet restrictors in the width direction and above the sheet feeding position in the stacking direction. The position detector detects a position of the pair of sheet restrictors in the width direction.

A post-processing apparatus includes: a processing unit configured to pull in a recording medium transported from an upstream apparatus and perform processing on the recording medium; a discharge unit to which the recording medium processed by the processing unit is discharged; and a lifting drive device configured to, in a case where a folded recording medium is pulled into the processing unit, move the discharge unit downward such that a height of the discharge unit is lower than a height of the discharge unit in a case where an unfolded recording medium is pulled into the processing unit.

An image forming apparatus includes a paper feeding cassette, a first conveying unit, a lift mechanism, a motor, a second conveying unit, and a control unit. The controller drives the motor and, if a value indicating a movement amount of the tray moving from when the lift mechanism starts the lifting of the tray until when a position of the top part reaches a first position is a first value, matches a position of the first conveying unit, which comes into contact with the top part to thereby rise together with the tray, with a second position and, if the value indicating the movement amount is a second value larger than the first value, matches the position of the first conveying unit, which comes into contact with the top part to thereby rise together with the tray, with a third position lower than the second position.