A medium conveying apparatus includes a conveyance roller to convey a medium, an imaging device to image the medium, a DC motor to drive the conveyance roller, a processor to detect that a front end of the medium reaches between the conveyance roller and the imaging device, set a current limit value of the DC motor to a first limit value until the front end of the medium reaches between the conveyance roller and the imaging device, and change the current limit value to a second limit value larger than the first limit value after the front end of the medium has reached between the conveyance roller and the imaging device, and drive the conveyance roller by rotating the DC motor based on the second limit value when the imaging device performs imaging.

In a case where starting feeding of a subsequent sheet by a feed roller after reaching of the trailing edge of a preceding sheet is detected by a post-registration sensor, a control unit of a sheet feeder controls the feed roller to rotate at a first feeding speed, and in a case where the leading edge of the subsequent sheet has passed through a nip position between the feed roller and a separation roller, the control unit controls the feed roller to rotate at a second feeding speed.

A sheet conveying device includes a first roller, a second roller, and a controller. The first roller is configured to rotate in a forward direction for sheet conveyance along a sheet conveying direction. The second roller is disposed downstream with respect to the first roller in the sheet conveying direction and configured to rotate in a forward direction along the sheet conveying direction and in a reverse direction. The controller is configured to control the second roller to rotate in the reverse direction at a timing when a leading end of a sheet that is nipped and conveyed by the first roller reaches a nip of the second roller.

A sheet conveying device includes a first roller, a second roller, and a controller. The first roller is configured to rotate in a forward direction for sheet conveyance along a sheet conveying direction. The second roller is disposed downstream with respect to the first roller in the sheet conveying direction and configured to rotate in a forward direction along the sheet conveying direction and in a reverse direction. The controller is configured to control the second roller to rotate in the reverse direction at a timing when a leading end of a sheet that is nipped and conveyed by the first roller reaches a nip of the second roller.

A sheet conveying apparatus includes a stacking unit, a feeding unit, a conveying path, a first conveying roller, a second conveying roller, a controller configured to execute first driving for executing a driving of the first conveying roller and a driving of the second conveying roller, a discriminator configured to determine a position of the sheet based on a value of a parameter corresponding to a load torque applied to a motor for driving a conveying roller driven during the first driving, and a storage unit configured to store information regarding the position.

A sheet conveying apparatus includes a stacking unit, a feeding unit, a conveying path, a first conveying roller, a second conveying roller, a controller configured to execute first driving for executing a driving of the first conveying roller and a driving of the second conveying roller, a discriminator configured to determine a position of the sheet based on a value of a parameter corresponding to a load torque applied to a motor for driving a conveying roller driven during the first driving, and a storage unit configured to store information regarding the position.

A sheet-processing machine and a method for operating a sheet-processing machine are disclosed. Sheets from a stack are separated and are accelerated, by a primary acceleration device, to a first speed and are then accelerated by a secondary acceleration device, to a second speed and then are processed by a processing module at a processing speed. The first speed is at least 20% lower than the processing speed. A drive of the primary acceleration device and a drive of the secondary acceleration device and a drive of the processing module, each have dedicated drive control systems which are connected, by circuitry, to a machine controller of the sheet-processing machine.

The sheet feeding apparatus includes an encoder configured to output a signal according to the rotation state of a retard roller, a feed motor configured to drive a pick-up roller, and a control unit configured to control the feed motor, make the pick-up roller feed a first sheet, and change the timing at which the pick-up roller is made to feed a second sheet following the first sheet, based on a signal output from the encoder after the trailing edge of the first sheet passes a separation nip portion.

The sheet feeding apparatus includes an encoder configured to output a signal according to the rotation state of a retard roller, a feed motor configured to drive a pick-up roller, and a control unit configured to control the feed motor, make the pick-up roller feed a first sheet, and change the timing at which the pick-up roller is made to feed a second sheet following the first sheet, based on a signal output from the encoder after the trailing edge of the first sheet passes a separation nip portion.

A medium transport apparatus includes: a medium mounting section configured to mount a medium; a feed roller configured to feed the medium from the medium mounting section; a separation roller configured to nip and separate the medium from the feed roller; a plurality of sensors disposed at positions facing a surface of the medium and configured to detect movement of the medium; and a control unit configured to stop feeding of the medium based on detection values received from the sensors, wherein the plurality of sensors are disposed upstream of a nipping position by the feed roller and the separation roller with a gap in a width direction being a direction intersecting a medium feed direction and detect movement of the medium in the width direction.