A medium transporting apparatus includes a feeding roller that rotates to transport a medium along a transportation path, an electrode installed downstream of the feeding roller on the transportation path and having conductivity, and an electric charge detecting circuit that outputs a signal having a magnitude corresponding to an amount of an electric charge, which moves from the medium to the electrode after the medium being transported along the transportation path comes into contact with the electrode.

A sheet discharging device includes: a medium supporting portion configured to support a transported medium, the medium supporting portion being configured to swing; a stacking portion which is provided vertically below the medium supporting portion and on which the medium dropped from the medium supporting portion is stacked, the stacking portion being configured to move up and down; and a detecting portion that detects swinging of the medium supporting portion, in which the detecting portion detects the swinging of the medium supporting portion when the medium on the rising stacking portion comes into contact with a lower surface of the medium supporting portion.

A sheet discharging device includes: a medium supporting portion configured to support a transported medium, the medium supporting portion being configured to swing; a stacking portion which is provided vertically below the medium supporting portion and on which the medium dropped from the medium supporting portion is stacked, the stacking portion being configured to move up and down; and a detecting portion that detects swinging of the medium supporting portion, in which the detecting portion detects the swinging of the medium supporting portion when the medium on the rising stacking portion comes into contact with a lower surface of the medium supporting portion.

An image reading apparatus includes a first stacking unit having a stacking surface, and an abutment portion that abuts a document stacked on the stacking surface, a feeding unit, a reading unit, a second stacking unit, a first detection unit, a rotating shaft, a drive unit, and a control unit. The second stacking unit receives the document fed by the feeding unit and read by the reading unit. The first detection unit detects presence or absence of the document stacked on the first stacking unit. The drive unit rotates the first stacking unit around the rotating shaft rotatably supporting the first stacking unit. At a predetermined timing after the first detection unit detects the absence of the document on the first stacking unit, the control unit controls the drive unit to rotate the first stacking unit in a direction with which the abutment portion is lowered.

An image reading apparatus includes a first stacking unit having a stacking surface, and an abutment portion that abuts a document stacked on the stacking surface, a feeding unit, a reading unit, a second stacking unit, a first detection unit, a rotating shaft, a drive unit, and a control unit. The second stacking unit receives the document fed by the feeding unit and read by the reading unit. The first detection unit detects presence or absence of the document stacked on the first stacking unit. The drive unit rotates the first stacking unit around the rotating shaft rotatably supporting the first stacking unit. At a predetermined timing after the first detection unit detects the absence of the document on the first stacking unit, the control unit controls the drive unit to rotate the first stacking unit in a direction with which the abutment portion is lowered.

An image reading apparatus includes a stacking unit having an abutment portion, a feeding unit, a conveyance unit, a reading unit, a rotating shaft, and a drive unit. The abutment portion abuts a document end in a widthwise direction of a document stacked on the stacking unit. The conveyance unit conveys the stacked document fed by the feeding unit in a feeding direction perpendicularly intersecting the document widthwise direction. The reading unit reads an image of the document. The drive unit rotates the stacking unit, rotatably supported by the rotating shaft, around the rotating shaft. The rotating shaft is disposed at a position where at least a part of the rotating shaft exists between one end and other end in the document widthwise direction of a document having a maximum width conveyable by the conveyance unit in a state where the maximum width document abuts on the abutment portion.

An image reading apparatus includes a stacking unit having an abutment portion, a feeding unit, a conveyance unit, a reading unit, a rotating shaft, and a drive unit. The abutment portion abuts a document end in a widthwise direction of a document stacked on the stacking unit. The conveyance unit conveys the stacked document fed by the feeding unit in a feeding direction perpendicularly intersecting the document widthwise direction. The reading unit reads an image of the document. The drive unit rotates the stacking unit, rotatably supported by the rotating shaft, around the rotating shaft. The rotating shaft is disposed at a position where at least a part of the rotating shaft exists between one end and other end in the document widthwise direction of a document having a maximum width conveyable by the conveyance unit in a state where the maximum width document abuts on the abutment portion.

An image reading apparatus includes a first stacking unit having a stacking surface, and an abutment portion that abuts a document stacked on the stacking surface, a feeding unit, a reading unit, a second stacking unit, a detection unit, a rotating shaft, a drive unit, and a control unit. The second stacking unit receives the document fed by the feeding unit and read by the reading unit. The detection unit detects presence or absence of the document stacked on the second stacking unit. The drive unit rotates the first stacking unit around the rotating shaft rotatably supporting the first stacking unit. Based on the detection of the absence of the document on the second stacking unit by the detection unit, the control unit controls the drive unit to rotate the first stacking unit in a direction with which the abutment portion is lowered.

An image reading apparatus includes a first stacking unit having a stacking surface, and an abutment portion that abuts a document stacked on the stacking surface, a feeding unit, a reading unit, a second stacking unit, a detection unit, a rotating shaft, a drive unit, and a control unit. The second stacking unit receives the document fed by the feeding unit and read by the reading unit. The detection unit detects presence or absence of the document stacked on the second stacking unit. The drive unit rotates the first stacking unit around the rotating shaft rotatably supporting the first stacking unit. Based on the detection of the absence of the document on the second stacking unit by the detection unit, the control unit controls the drive unit to rotate the first stacking unit in a direction with which the abutment portion is lowered.

A method of grouping sheet units, which belong together in sheet groups, a sheet stream comprising two superposed sheet units each by means of a grouping unit, a grouping unit for a sheet handling system, and a sheet handling system that allow a high processing speed and a high cycle efficiency of a sheet handling system are disclosed. A sheet unit can be held back in the grouping unit. Depending on whether the downstream subsequent sheet units transferred into the grouping unit belong to a sheet group, the held-back sheet unit can be released by itself and together with one or together with both downstream subsequent sheet units.