A sheet processing apparatus comprises a roller disposed in a sheet conveyance path; a sheet sensor disposed in the sheet conveyance path and configured to detect conveyance of sheets and generate sensor information indicative of detection; and a controller. The controller is configured to, for each sheet of a predetermined number of sheets of a plurality of sheets conveyed by the roller, use the sensor information to generate an individual sheet-conveyance dataset indicating a sheet passage interval; and store the individual sheet-conveyance dataset in data storage. The controller is further configured to, after the roller conveys the predetermined number of sheets, calculate a summary sheet-conveyance dataset including sheet passage interval statistics for the predetermined number of sheets; store the summary sheet-conveyance dataset in the data storage; discard the individual sheet-conveyance datasets from the data storage; and evaluate the sheet passage interval statistics to determine whether to modify the predetermined number of sheets.

A sheet conveying device includes a sheet loader, a sheet feeder, an optical sensor, and a rotary member. The sheet loader is configured to load a sheet. The sheet feeder is configured to feed the sheet loaded on the sheet loader. The optical sensor is configured to detect the sheet at a predetermined position on the sheet loader in a width direction of the sheet and at a predetermined position in a sheet conveyance passage in the width direction of the sheet. The rotary member is configured to rotate to a first position when the sheet is not at the predetermined position on the sheet loader and a second position when the sheet is at the predetermined position. The rotary member has a detection target portion configured to be detected by the optical sensor when the rotary member is located at the first or second position.

An image forming apparatus includes a control unit and an attachment detection unit to detect attachment of a cassette having a stacking portion that may be lifted by a motor. The control unit drives the motor to start lifting the stacking portion when cassette attachment is detected and stops when the stacked uppermost sheet is detected at a sheet feed position, at which time the presence or absence of the stored sheet is determined based on a detection signal output by a sheet presence/absence detection unit. In a case where there is no change in the detection signal output from the sheet presence/absence detection unit when the attachment of the cassette is detected, the control unit determines that a failure of the sheet presence/absence detection flag occurred.

An image forming apparatus includes a control unit and an attachment detection unit to detect attachment of a cassette having a stacking portion that may be lifted by a motor. The control unit drives the motor to start lifting the stacking portion when cassette attachment is detected and stops when the stacked uppermost sheet is detected at a sheet feed position, at which time the presence or absence of the stored sheet is determined based on a detection signal output by a sheet presence/absence detection unit. In a case where there is no change in the detection signal output from the sheet presence/absence detection unit when the attachment of the cassette is detected, the control unit determines that a failure of the sheet presence/absence detection flag occurred.

A medium conveying apparatus includes a storage device, a feed roller to feed a medium, and a processor to determine whether a conveyance abnormality of the medium fed by the feed roller has occurred, store in the storage device that the conveyance abnormality has occurred and stop feeding of the medium when the processor determines that the conveyance abnormality has occurred, and notify a user of a cleaning instruction or a replacement instruction of the feed roller based on an occurrence degree of the conveyance abnormality for a plurality of media fed by the feed roller.

A transporting device sends a sheet with the rotation of a first drive roller with the sheet sandwiched between a first drive roller and a driven roller. The sheet is sent to a direction to which a back surface thereof is pressed against a guide surface, and is transported to a second drive roller in a state of being pressed against the guide surface after the guide surface pushing and bending a transport path toward a front surface side. A lifted amount of the sheet from the guide surface is monitored by a sensor, and the transportation is stopped in a case where the lifted amount is equal to or larger than a predetermined amount.

A transporting device sends a sheet with the rotation of a first drive roller with the sheet sandwiched between a first drive roller and a driven roller. The sheet is sent to a direction to which a back surface thereof is pressed against a guide surface, and is transported to a second drive roller in a state of being pressed against the guide surface after the guide surface pushing and bending a transport path toward a front surface side. A lifted amount of the sheet from the guide surface is monitored by a sensor, and the transportation is stopped in a case where the lifted amount is equal to or larger than a predetermined amount.

A conveying device includes a rotating carrier, an inlet rotary body, an outlet rotary body, a downstream conveyor, and an inching controller. The rotating carrier carries a sheet. The inlet rotary body transfers the sheet to the rotary carrier from upstream of the rotary carrier in a conveyance direction of the sheet. The outlet rotary body transfers the sheet to a downstream area from the rotary carrier in the conveyance direction. The downstream conveyor conveys the sheet downstream from the outlet rotary body in the conveyance direction. The inching controller performs an inching operation to convey the sheet on a conveyance path including at least the downstream conveyor. The inching controller causes at least the outlet rotary body and the downstream conveyor to perform a conveying operation in conjunction with each other in the inching operation.

A medium processing apparatus includes a liquid applier, a crimper, a stapler, and circuitry. The liquid applier applies liquid to a liquid application position of a medium. The crimper presses and deforms at least a part to which the liquid is applied by the liquid applier, to bind a plurality of media including the medium to which the liquid is applied. The stapler performs stapling with a staple on a medium bundle in which the plurality of media is bound by the crimper. The circuitry controls operations of the crimper, the liquid applier, and the stapler, and selectively switches between first binding performed by the liquid applier and the crimper and second binding performed by only the stapler, in accordance with information on the medium or a binding position at which the medium bundle is bound by the crimper.

A sheet conveyance apparatus includes a conveyance roller, an abutment member including an abutment surface against which a side edge, in a width direction, of the sheet abuts, and configured to correct a skew of the sheet, an obliquely conveying roller configured to convey the sheet such as the side edge of the sheet is conveyed toward the abutment surface, a sheet side edge detection portion configured to detect a position of the side edge of the sheet, and a control unit configured to control that a conveyance force, in the width direction, by the obliquely conveying roller in response to a detection result of the sheet side edge detection portion becomes smaller than that in an abutment movement.