A medium supply apparatus includes: a placement mount on which a plurality of media are placed; a transportation mechanism that transports an uppermost medium of the plurality of media placed on the placement mount; and an aspiration mechanism that aspirates air to attract the uppermost medium to the transportation mechanism, wherein the aspiration mechanism includes a blocking means for blocking air aspiration performed by the aspiration mechanism, in such a manner as to prevent another medium of the plurality of media that is located below the uppermost medium from being attracted to the transportation mechanism.

Disclosed is a paper feeding device (10) comprising a storage surface (14) for a stack of papers (12), with a leading edge (14a), a trailing edge (14b), and a first and a second side edge (14c, 14d). The surface (14) is adapted to be moved vertically. The device further comprises a vacuum feeder (16) for feeding papers from their position on the storage surface (14) and imparting on an uppermost sheet of paper (12a) a horizontal displacement, and a blower arrangement (18, 20) adapted to provide a curtain of air separating the uppermost sheet of paper (12a) from the rest of the stack of papers. The device further comprises a sensor arrangement (22) arranged to determine where the upper paper sheets in the stack of papers (12) start to separate from the rest of the paper sheets, the sensor arrangement (22) comprising a plurality of infrared reflective sensors (22a).

A suction fan of a sheet feeder sucks in air through a sheet feeding belt to generate flotation air. The suction fan uses the flotation air to attract set sheets by suction. A belt motor rotates a sheet feeding belt and feeds out a sheet of the set sheets. An interval measurer measures a sheet-to-sheet interval when the suction fan is attracting the sheet by suction. Based on an output of the interval measurer, a controller recognizes the sheet-to-sheet interval. Based on the recognized sheet-to-sheet interval, the controller adjusts a flow rate of the flotation air.

A sheet feeding apparatus includes a sheet loader, a rear end holder, an air blower, a front end holder, a sender and an air controller. The sheet loader stores stacked sheets. The rear end holder holds a rear end of a topmost sheet on the sheet loader. The air blower blows air to the loaded sheets to raise a sheet. The front end holder holds a front end of the raised topmost sheet. The sender sends the sheet in the sheet feeding direction. The air controller controls the air blower to start blowing a raising air to raise the sheet after the rear end holder holds the rear end of a next sheet that is stacked under the topmost sheet before a rear end of the topmost sheet sent in the sheet feeding direction by the sender passes through the front end holder.

A medium supply apparatus includes: a placement mount on which a plurality of media are placed; a transportation mechanism that transports an uppermost medium of the plurality of media placed on the placement mount; and an aspiration mechanism that aspirates air to attract the uppermost medium to the transportation mechanism, wherein the aspiration mechanism includes a blocking means for blocking air aspiration performed by the aspiration mechanism, in such a manner as to prevent another medium of the plurality of media that is located below the uppermost medium from being attracted to the transportation mechanism.

A sheet feeding device includes a sheet stacker configured to stack a sheet bundle; a blower configured to float a sheet on an upper portion of the sheet bundle; a conveyor configured to convey the sheet floated by the blower; a lift configured to lift up and down the sheet stacker; a first reflective optical sensor configured to detect the sheet floated by the blower; a second reflective optical sensor configured to detect the sheet bundle and a side face of the sheet stacker, the side face including a detection region to be detected by the second reflective optical sensor and a non-detection region not to be detected by the second reflective optical sensor; and circuitry configured to control the lift based on a detection result of the first reflective optical sensor and a detection result of the second reflective optical sensor. The circuitry is configured to cause the lift to lift up the sheet stacker in response to a change from a detection state to a non-detection state of the second reflective optical sensor.

A suction fan of a sheet feeder sucks in air through a sheet feeding belt to generate flotation air. The suction fan uses the flotation air to attract set sheets by suction. A belt motor rotates a sheet feeding belt and feeds out a sheet of the set sheets. An interval measurer measures a sheet-to-sheet interval when the suction fan is attracting the sheet by suction. Based on an output of the interval measurer, a controller recognizes the sheet-to-sheet interval. Based on the recognized sheet-to-sheet interval, the controller adjusts a flow rate of the flotation air.

Disclosed is a paper feeding device comprising a storage surface for a stack of papers, with a leading edge, a trailing edge, and a first and a second side edge. The surface is adapted to be moved vertically. The device further comprises a vacuum feeder for feeding papers from their position on the storage surface and imparting on an uppermost sheet of paper a horizontal displacement, and a blower arrangement adapted to provide a curtain of air separating the uppermost sheet of paper from the rest of the stack of papers. The blower arrangement comprises a front blower unit having air openings with a first portion adapted to create first air cones and second portions adapted to create second air cones, wherein the first air cones are different from the second air cones.

A feeding device includes a suction feeding unit having a belt for feeding a sheet in a suction state and a belt driving unit, a sheet detection sensor, and a control unit. The control unit controls the belt drive unit so as to feed the sheet in a feeding direction at a first speed. If the sheet does not arrive at the sheet detection sensor, the control unit controls the belt drive unit so as to execute a low-speed feeding of moving the belt in the feeding direction at a second speed lower than the first speed or so as to execute a reverse feeding of moving the belt in a reverse feeding direction opposite to the feeding direction.

A sheet feeding device includes a sheet stacking table, an air blower, a feeder, and an air sucker. The sheet stacking table stacks a bundle of sheets. The air blower blows air to the bundle of sheets to float an uppermost sheet from the bundle of sheets. The feeder feeds the uppermost sheet. The air sucker sucks air in such a direction that a sheet in vicinity of the uppermost sheet moves away from the feeder. The air sucker includes a suction nozzle to suck air, a suction fan to generate a negative pressure, a suction duct to communicate the suction nozzle with the suction fan, and an opening-and-closing mechanism to shut off and release ventilation in the suction duct.