In order to properly suppress a discharge defect corresponding to an image ratio of a sheet, in the case where a coefficient of friction is different according to the image ratio of an image on the sheet, an air blowing section is arranged to blow air toward a downstream side in a transport direction from between a downstream-side end portion of a first stacking section and an upstream-side end portion of a second stacking section. When an image ratio of an image on a sheet by an image forming apparatus is a first value, the air blowing section sets an air quantity blown to the sheet at a first air quantity F1, while when the image ratio is a second value higher than the first value, setting the air quantity blown to the sheet at a second air quantity F2 larger than the first air quantity F1.

A paper stacking device includes: a stacker on which paper is stacked; a paper ejector that ejects the paper; an aligning plate that is provided on a side of the paper, and aligns a side end of the paper; a paper floating member that is provided in the aligning plate, and supports, from below, the side end of the paper; and a blower that is provided on the side of the paper across the aligning plate, and blows air, wherein the aligning plate includes a blowing opening through which air from the blower is blown, the paper floating member is switched between: a paper floating position; and a retreat position, when the paper floating member is located in the paper floating position, the blowing opening is opened, and when the paper floating member is located in the retreat position, the blowing opening is shielded.

A paper stacking device includes: a stacker on which paper is stacked; a paper ejector that ejects the paper; an aligning plate that is provided on a side of the paper, and aligns a side end of the paper; a paper floating member that is provided in the aligning plate, and supports, from below, the side end of the paper; and a blower that is provided on the side of the paper across the aligning plate, and blows air, wherein the aligning plate includes a blowing opening through which air from the blower is blown, the paper floating member is switched between: a paper floating position; and a retreat position, when the paper floating member is located in the paper floating position, the blowing opening is opened, and when the paper floating member is located in the retreat position, the blowing opening is shielded.

A sheet feeding apparatus includes a sheet supporting portion, a sheet feeding portion configured to feed a sheet supported on the sheet supporting portion in a sheet feeding direction, an air blow unit including an air blower, an opening portion, a duct configured to form a flow path through which air flows, an adjustment portion configured to vary an opening dimension, the air blow unit being configured to separate a plurality of sheets, including an uppermost sheet, a drive source configured to drive the adjustment portion, and a control unit configured to execute a first mode in which the drive source is controlled such that the opening dimension is set to a first dimension, and a second mode in which the drive source is controlled such that the opening dimension is set to a second dimension that is smaller than the first dimension.

A feeding apparatus comprises a blower unit that is able to perform a first air blowing operation on sheets which are stacked on a stacking unit, and a second air blowing operation in which the volume of air blowing is smaller than volume of air blowing in the first air blowing operation; a feeding unit, brought into contact with the sheets stacked on the stacking unit and located on a feeding position to which feeding is performed while pressing the sheets from above, for feeding the sheets on which the first air blowing operation has been performed; and a control unit for controlling the blower unit to perform the first air blowing operation until a start of feeding by the feeding unit so as to separate the sheets stacked on the stacking unit.

A feeding apparatus comprises a blower unit that is able to perform a first air blowing operation on sheets which are stacked on a stacking unit, and a second air blowing operation in which the volume of air blowing is smaller than volume of air blowing in the first air blowing operation; a feeding unit, brought into contact with the sheets stacked on the stacking unit and located on a feeding position to which feeding is performed while pressing the sheets from above, for feeding the sheets on which the first air blowing operation has been performed; and a control unit for controlling the blower unit to perform the first air blowing operation until a start of feeding by the feeding unit so as to separate the sheets stacked on the stacking unit.

A paper feeding apparatus includes a tray, an air blower, a floating detector, and a hardware processor. In the tray, a sheet of paper is loaded. The air blower blows air to the sheet loaded in the tray to float the sheet. The floating detector is provided above the sheet loaded in the tray and detects the floating of the sheet to a predetermined level. The hardware processor causes the air blower to blow the air and determines a basis weight of the sheet loaded in the tray from an air amount that has caused the floating detector to detect the floating of the sheet.

A paper feeding apparatus includes a tray, an air blower, a floating detector, and a hardware processor. In the tray, a sheet of paper is loaded. The air blower blows air to the sheet loaded in the tray to float the sheet. The floating detector is provided above the sheet loaded in the tray and detects the floating of the sheet to a predetermined level. The hardware processor causes the air blower to blow the air and determines a basis weight of the sheet loaded in the tray from an air amount that has caused the floating detector to detect the floating of the sheet.

A paper feeding parameter management system may include air paper feeding devices and a management device. Each of the air paper feeding devices may be provided with an air paper feeder which may feed paper by blowing air and by absorption to paper and which may be provided with a paper feeding parameter capable of being switched. Each of the air paper feeding devices may be provided with a paper type information obtaining unit and a hardware processor. The paper type information obtaining unit may obtain paper type information of paper to be fed. The hardware processor (i) may adjust the paper feeding parameter of the air paper feeder and (ii) may transmit the paper type information, device configuration information regarding a device configuration of the air paper feeding device, and the adjusted paper feeding parameter to the management device.

A paper feeding parameter management system may include air paper feeding devices and a management device. Each of the air paper feeding devices may be provided with an air paper feeder which may feed paper by blowing air and by absorption to paper and which may be provided with a paper feeding parameter capable of being switched. Each of the air paper feeding devices may be provided with a paper type information obtaining unit and a hardware processor. The paper type information obtaining unit may obtain paper type information of paper to be fed. The hardware processor (i) may adjust the paper feeding parameter of the air paper feeder and (ii) may transmit the paper type information, device configuration information regarding a device configuration of the air paper feeding device, and the adjusted paper feeding parameter to the management device.