A sheet conveying apparatus includes an abutment member against which a leading end of a sheet conveyed by a conveying roller abuts, a phase determiner that determines a rotation phase of a rotor of a motor driving the conveying roller, a controller that controls the motor by controlling the value of a torque current component and the value of an excitation current component so that a difference between an instruction phase and the rotation phase is decreased, and a torque determiner that determines load torque exerted on the rotor. The controller continues driving of the motor if the load torque is lower than predetermined torque in a state in which the leading end of the sheet abuts against the abutment member to deflect the sheet and stops the driving of the motor if the load torque is higher than or equal to the predetermined torque.

A conveying mechanism has a pair of nipping members configured to nip a sheet from both sides thereof at a nipping position and to convey the sheet from upstream to downstream side. The pair of nipping members includes a conveying roller. A controller performs: a motor controlling process of controlling the motor to perform a conveying operation of the sheet by rotation of the conveying roller; a reaction-force calculating process of calculating a reaction-force inference value which corresponds to reaction force that acts on the motor, by removing a friction component generated due to rotation of the motor from a disturbance inference value, the disturbance inference value being calculated from both a control input to the motor and a control output relative to the control input; and a warning process of outputting warning in response to occurrence of multiple feeding of the sheet, based on the reaction-force inference value.

A conveying mechanism has a pair of nipping members configured to nip a sheet from both sides thereof at a nipping position and to convey the sheet from upstream to downstream side. The pair of nipping members includes a conveying roller. A controller performs: a motor controlling process of controlling the motor to perform a conveying operation of the sheet by rotation of the conveying roller; a reaction-force calculating process of calculating a reaction-force inference value which corresponds to reaction force that acts on the motor, by removing a friction component generated due to rotation of the motor from a disturbance inference value, the disturbance inference value being calculated from both a control input to the motor and a control output relative to the control input; and a warning process of outputting warning in response to occurrence of multiple feeding of the sheet, based on the reaction-force inference value.

A sheet feeding apparatus includes an endless attraction member (200) attracting a sheet and rotating, and the attraction member (200) includes a plurality of electrode pattern areas. Each of the electrode pattern areas includes first and second electrodes (510 and 511) supplied the voltages from a power feed portion respectively. The electrode pattern areas are arrayed in the circumferential direction in such a manner that the electrode pattern areas are electrically insulated each other, and each circumferential direction length of the electrode pattern areas is set shorter than a circumferential direction length, between the power feed portion and the discharge portion, of the attraction member.

A sheet feeding apparatus includes an endless attraction member (200) attracting a sheet and rotating, and the attraction member (200) includes a plurality of electrode pattern areas. Each of the electrode pattern areas includes first and second electrodes (510 and 511) supplied the voltages from a power feed portion respectively. The electrode pattern areas are arrayed in the circumferential direction in such a manner that the electrode pattern areas are electrically insulated each other, and each circumferential direction length of the electrode pattern areas is set shorter than a circumferential direction length, between the power feed portion and the discharge portion, of the attraction member.

Provided is a transport device including a transport unit that transports a recording medium by interposing the recording medium, a driving unit that drives the transport unit, a detection unit that detects a peak value of a load of the driving unit when the recording medium is discharged from the transport unit, and a derivation unit that derives a thickness of the recording medium based on the peak value detected by the detection unit.

Provided is a transport device including a transport unit that transports a recording medium by interposing the recording medium, a driving unit that drives the transport unit, a detection unit that detects a peak value of a load of the driving unit when the recording medium is discharged from the transport unit, and a derivation unit that derives a thickness of the recording medium based on the peak value detected by the detection unit.

A sheet feeder is provided. The sheet feeder includes a roller to feed a sheet, a motor to rotate the roller, and a motor controller to control rotation of the motor by a feedback control. The motor controller detects a condition of the sheet based on a value acquired in the feedback control at the time a load is applied from the sheet to the roller, while performing a stop control to stop the roller at a designated stop position. The stop control is performed after the motor is rotated in a direction opposite to a direction of feed of the sheet.

A sheet feeder is provided. The sheet feeder includes a roller to feed a sheet, a motor to rotate the roller, and a motor controller to control rotation of the motor by a feedback control. The motor controller detects a condition of the sheet based on a value acquired in the feedback control at the time a load is applied from the sheet to the roller, while performing a stop control to stop the roller at a designated stop position. The stop control is performed after the motor is rotated in a direction opposite to a direction of feed of the sheet.

A sheet feed cassette monitor includes an actuator with another end portion, a detecting circuit, a plurality of protrusions, a signal monitoring circuit, and a signal determining circuit. When the one end portion is in contact with a paper sheet, the other end portion swings in a first direction. When the one end portion is not in contact with the paper sheet, the other end portion swings in a second direction opposite direction to the first direction. The detecting circuit detects the swinging of the other end portion on the actuator. The plurality of protrusions are convexly installed in an asymmetric manner with respect to a putting-in/taking-out direction of the feed cassette. The signal determining circuit determines a presence/absence state of the paper sheet housed in the sheet feed cassette and an open/close state of the sheet feed cassette based on a pattern of change in the monitored signal.