An image forming apparatus includes an image forming device, a transport route, a purge transport route, an image forming transport route, a transport roller, and a blowing machine. The image forming device forms an image on a sheet. The transport route extends to a predetermined position. The purge transport route extends to a downstream side in a sheet transport direction, from the predetermined position. The image forming transport route is branched from the purge transport route at the predetermined position, and extends toward the image forming device. The transport roller transports the sheet along the transport route, and along one of the purge transport route and the image forming transport route. The blowing machine delivers the sheet to one of the purge transport route and the image forming transport route, by blowing air to the sheet being transported along the transport route.

An image forming apparatus includes an image forming device, a transport route, a purge transport route, an image forming transport route, a transport roller, and a blowing machine. The image forming device forms an image on a sheet. The transport route extends to a predetermined position. The purge transport route extends to a downstream side in a sheet transport direction, from the predetermined position. The image forming transport route is branched from the purge transport route at the predetermined position, and extends toward the image forming device. The transport roller transports the sheet along the transport route, and along one of the purge transport route and the image forming transport route. The blowing machine delivers the sheet to one of the purge transport route and the image forming transport route, by blowing air to the sheet being transported along the transport route.

An image forming apparatus includes a sheet accommodation unit, a feed roller to feed a sheet along a conveyance path, a first encoder to detect rotation of the feed roller, a conveying roller downstream of the feed roller, a second encoder to detect rotation of the conveying roller, and a motor to drive the feed roller and the conveying roller. A first clutch switches between connecting and disconnecting the paper feed roller to the motor. A second clutch switches between connecting and disconnecting the motor to the conveying roller. A first sensor detects the sheet at a first position. A second sensor detects the sheet at a second position. A control unit controls the motor based on output from the first encoder when the sheet is at the first position and output from the second encoder when the sheet is at the second position.

An image forming apparatus includes a sheet accommodation unit, a feed roller to feed a sheet along a conveyance path, a first encoder to detect rotation of the feed roller, a conveying roller downstream of the feed roller, a second encoder to detect rotation of the conveying roller, and a motor to drive the feed roller and the conveying roller. A first clutch switches between connecting and disconnecting the paper feed roller to the motor. A second clutch switches between connecting and disconnecting the motor to the conveying roller. A first sensor detects the sheet at a first position. A second sensor detects the sheet at a second position. A control unit controls the motor based on output from the first encoder when the sheet is at the first position and output from the second encoder when the sheet is at the second position.

A printing apparatus includes: a printing section; a print conveyor conveying a medium in the printing section; a constant-speed conveyor conveying the medium at a variable constant conveying speed in a circulation route for duplex printing; a registration roller pair against which the medium to be conveyed to the printing section is caused to abut; and a processor determining a conveyance schedule for the medium based on at least one of a first conveyance route length between a downstream end portion in a conveying direction of the print conveyor and an upstream end portion in the conveying direction of the constant-speed conveyor and a second conveyance route length between a downstream end portion in the conveying direction of the constant-speed conveyor and the registration roller pair, and a medium length in the conveying direction of the medium.

A printing apparatus includes: a printing section; a print conveyor conveying a medium in the printing section; a constant-speed conveyor conveying the medium at a variable constant conveying speed in a circulation route for duplex printing; a registration roller pair against which the medium to be conveyed to the printing section is caused to abut; and a processor determining a conveyance schedule for the medium based on at least one of a first conveyance route length between a downstream end portion in a conveying direction of the print conveyor and an upstream end portion in the conveying direction of the constant-speed conveyor and a second conveyance route length between a downstream end portion in the conveying direction of the constant-speed conveyor and the registration roller pair, and a medium length in the conveying direction of the medium.

A document receiving apparatus comprises a receiving port configured to receive a document into an apparatus main body, a document stopper configured to be pivotable between a first posture in which reception of the document is suppressed and a second posture in which the reception is permitted, a holding portion configured to hold the document stopper in the first posture, and a biasing portion configured to bias the document stopper held in the first posture to be set in the second posture

A document receiving apparatus comprises a receiving port configured to receive a document into an apparatus main body, a document stopper configured to be pivotable between a first posture in which reception of the document is suppressed and a second posture in which the reception is permitted, a holding portion configured to hold the document stopper in the first posture, and a biasing portion configured to bias the document stopper held in the first posture to be set in the second posture

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.

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.