Abstract: A sheet feeding apparatus includes a sheet stacker, an air blower, a suction feeder, a lifting mechanism, an elevation detection sensor, an elevation detection sensor, a feed detection sensor, and processing circuitry. The air blower blows air to float an uppermost sheet of sheets stacked on the sheet stacker. The processing circuitry drives the lifting mechanism such that the sheet stacker is lifted by an elevation amount determined based on a sheet thickness of the sheets stacked on the sheet stacker, each time a sheet is detected when a number of sheets detected is smaller than a threshold number of sheets, and stops lifting of the sheet stacker until a sheet is not detected when the number of sheets reaches the threshold number of sheets, while repeatedly feeding the uppermost sheet and counting the number of sheets.

Abstract: A sheet separating device includes a stacker, a pickup member, an air supplier, and a sheet floating restraint. The stacker is configured to stack a plurality of sheets. The pickup member is configured to convey the plurality of sheets one by one from the stacker. The air supplier includes an air outlet, at a downstream side of the stacker in a sheet conveyance direction. The air supplier is configured to blow air toward a downstream end of the plurality of sheets in the sheet conveyance direction. The sheet floating restraint is configured to restrict floating of a part of the plurality of sheets separated by air blown from the air outlet. The sheet floating restraint is replaceable with another sheet floating restraint. The sheet floating restraint and said another sheet floating restraint have respective shapes different from each other.

Abstract: A sheet separating device includes a stacker, a pickup member, an air supplier and a sheet floating restraint. The stacker is configured to stack a plurality of sheets. The pickup member is configured to convey the plurality of sheets one by one from the stacker. Tile air supplier includes ail air outlet, at a downstream side of the stacker in a sheet conveyance direction. The air supplier is configured to blow air toward a downstream end of the plurality* of sheets in the sheet conveyance direction. The sheet floating restraint is configured to restrict floating of a part of the plurality of sheets separated by air blown from the air outlet. The sheet floating restraint is replaceable with another sheet floating restraint. The sheet floating restraint and said another sheet floating restraint have respective shapes different from each other.

Abstract: A sheet feeding device, which is included in an image forming apparatus and an image forming system, includes a sheet loader, an air drawing body, an attracting and conveying device, an air duct and a blocking device. The sheet loader is a device on which a bundle of sheets is loaded. The air drawing body is configured to generate suction air. The attracting and conveying device is configured to attract a sheet on top of the bundle of sheets by the suction air and convey the sheet. The air duct is configured to intake the suction air drawn by the air drawing body, to the attracting and conveying device. The blocking device is configured to block the suction air in the air duct.

Abstract: A sheet feeding device, which is included in an image forming apparatus and an image forming system, includes a sheet loader, an air drawing body, an attracting and conveying device, an air duct and a blocking device. The sheet loader is a device on which a bundle of sheets is loaded. The air drawing body is configured to generate suction air. The attracting and conveying device is configured to attract a sheet on top of the bundle of sheets by the suction air and convey the sheet. The air duct is configured to intake the suction air drawn by the air drawing body, to the attracting and conveying device. The blocking device is configured to block the suction air in the air duct.