A medium conveying apparatus includes a feed roller, a brake roller, a motor to generate a driving force, a first transmission mechanism to transmit the driving force to the brake roller through a first torque limiter, to rotate the brake roller in a direction opposite to a medium feeding direction, a second transmission mechanism to transmit the driving force to the brake roller through a second torque limiter, bypassing the first torque limiter, to rotate the brake roller in the direction opposite to the medium feeding direction, and a processor to detect media multi-feed, and perform control in such a way as to transmit the driving force to the brake roller by the second transmission mechanism and also cause the feed roller to be driven to rotate in the direction opposite to the medium feeding direction by the brake roller, when the media multi-feed is detected.

A sheet feeding device includes a conveyance rotator, a separation rotator, a torque applier, a torque control circuit, and a torque transmission switcher. The conveyance rotator conveys a sheet in a sheet feeding direction. The separation rotator sandwiches the sheet together with the conveyance rotator. The torque applier applies a reverse torque to the separation rotator in a sheet reversing direction to reverse the sheet. The torque control circuit controls the reverse torque applied to the separation rotator to be equal to or less than a given value. The torque transmission switcher switches, between a transmission state and a non-transmission state, a state of a torque transmission path between the torque applier and the separation rotator. The transmission state is a state in which the reverse torque is transmitted. The non-transmission state is a state in which the reverse torque is not transmitted.

A sheet feeding device includes a conveyance rotator, a separation rotator, a torque applier, a torque control circuit, and a torque transmission switcher. The conveyance rotator conveys a sheet in a sheet feeding direction. The separation rotator sandwiches the sheet together with the conveyance rotator. The torque applier applies a reverse torque to the separation rotator in a sheet reversing direction to reverse the sheet. The torque control circuit controls the reverse torque applied to the separation rotator to be equal to or less than a given value. The torque transmission switcher switches, between a transmission state and a non-transmission state, a state of a torque transmission path between the torque applier and the separation rotator. The transmission state is a state in which the reverse torque is transmitted. The non-transmission state is a state in which the reverse torque is not transmitted.

A sheet processing apparatus including a sheet feeder, a sheet processing device, a sheet ejection device, a purge unit, a multifeed sensor, a sheet sensor, and circuitry. The circuitry stops an operation of the sheet processing apparatus when the multifeed sensor has not detected multifeed of the sheet and the sheet sensor does not detect a trailing end of the sheet after a first set time from detection of a leading end of the sheet, stop the operation when the multifeed sensor has detected the multifeed and the sheet sensor does not detect the trailing end of the sheet after a second set time from the detection, and conveys the sheet toward the purge unit without stopping the operation when the multifeed sensor has detected the multifeed and the sheet sensor detects the trailing end of the sheet before the second set time elapses from the detection.

A sheet processing apparatus including a sheet feeder, a sheet processing device, a sheet ejection device, a purge unit, a multifeed sensor, a sheet sensor, and circuitry. The circuitry stops an operation of the sheet processing apparatus when the multifeed sensor has not detected multifeed of the sheet and the sheet sensor does not detect a trailing end of the sheet after a first set time from detection of a leading end of the sheet, stop the operation when the multifeed sensor has detected the multifeed and the sheet sensor does not detect the trailing end of the sheet after a second set time from the detection, and conveys the sheet toward the purge unit without stopping the operation when the multifeed sensor has detected the multifeed and the sheet sensor detects the trailing end of the sheet before the second set time elapses from the detection.

A conveying apparatus includes a conveyor and a conveyed object receptor. The conveyor includes a conveyance surface facing downward and configured to convey a conveyed object having a sheet-like shape. The conveyed object receptor is arranged below the conveyor and configured to receive the conveyed object having fallen from the conveyor.

A conveying apparatus includes a conveyor and a conveyed object receptor. The conveyor includes a conveyance surface facing downward and configured to convey a conveyed object having a sheet-like shape. The conveyed object receptor is arranged below the conveyor and configured to receive the conveyed object having fallen from the conveyor.

Embodiments of a system and method for shingulating, singulating, and synchronizing articles in an article feeder system are disclosed. The article feeder system may include a shingulating device configured to receive a stack of articles and to produce a positively lapped stack of articles, a plurality of picking devices configured to pick one or more articles from the positively lapped stack of articles and to produce one or more singulated articles, and one or more synchronization devices configured to deliver the one or more singulated articles to one or more sorter windows.

Embodiments of a system and method for shingulating, singulating, and synchronizing articles in an article feeder system are disclosed. The article feeder system may include a shingulating device configured to receive a stack of articles and to produce a positively lapped stack of articles, a plurality of picking devices configured to pick one or more articles from the positively lapped stack of articles and to produce one or more singulated articles, and one or more synchronization devices configured to deliver the one or more singulated articles to one or more sorter windows.

An image processing apparatus includes a transmitter, a receiver, a comparison circuit, and a control unit. The transmitter transmits an ultrasonic wave to a conveyance path through which a sheet is conveyed. The receiver faces the transmitter with the conveyance path in between, and receives the ultrasonic wave transmitted by the transmitter. The comparison circuit compares a level signal indicating a reception level of the ultrasonic wave received by the receiver with a threshold signal for determining whether or not the sheet is double-fed in the conveyance path, and outputs a comparison result signal according to the comparison result. The control unit determines whether or not there is a possibility of a defect in the double feed detection function of detecting double feed based on the comparison result signal and the level signal.