To prevent a failure or the like caused by winding of a tape in a reverse direction to a proper direction, a paper sheet circulation device includes a travelling-direction mark having a pattern that is formed along a travelling-direction of a detection tape and indicates the difference of the travelling-direction of the tape, and a sensor module that detects the travelling-direction mark and outputs a detection signal. The paper sheet circulation device determines a travelling-direction of the tape from a pattern signal in accordance with the travelling-direction of the tape acquired on the basis of a temporal change of the detection signal, and determines a winding direction of the tape on a drum from the travelling-direction of the tape and a rotation direction of the drum.

To prevent a failure or the like caused by winding of a tape in a reverse direction to a proper direction, a paper sheet circulation device includes a travelling-direction mark having a pattern that is formed along a travelling-direction of a detection tape and indicates the difference of the travelling-direction of the tape, and a sensor module that detects the travelling-direction mark and outputs a detection signal. The paper sheet circulation device determines a travelling-direction of the tape from a pattern signal in accordance with the travelling-direction of the tape acquired on the basis of a temporal change of the detection signal, and determines a winding direction of the tape on a drum from the travelling-direction of the tape and a rotation direction of the drum.

An image forming apparatus may comprise the following elements. A stacking unit in which a sheet is stacked. A conveyance unit conveys the sheet. A time-counting unit counts a conveyance time from when the conveyance unit starts to convey the sheet until the sheet arrives at a predetermined position on a conveyance path. A determination unit determines that over stacking has occurred, if the conveyance time of the sheet exceeds a first over stacking threshold value.

An image forming apparatus may comprise the following elements. A stacking unit in which a sheet is stacked. A conveyance unit conveys the sheet. A time-counting unit counts a conveyance time from when the conveyance unit starts to convey the sheet until the sheet arrives at a predetermined position on a conveyance path. A determination unit determines that over stacking has occurred, if the conveyance time of the sheet exceeds a first over stacking threshold value.

A sheet conveying apparatus capable of continuing conveyance of sheets without causing a jam even when a switching member performs an operation for switching a conveyance path again. A switching member is disposed at a branching point of a conveyance path through which the sheet is conveyed by a conveying unit, and is operated by a drive unit for witching a destination of conveyance of the sheet. A controller causes the drive unit to operate the switching member, and performs a checking operation for checking a state of the drive unit based on an output from a sensor that detects a state of the switching member. The controller controls a sheet conveyance interval between a first sheet conveyed by the conveying unit and a second sheet conveyed following the first sheet, according to a result of the checking operation.

A sheet conveying apparatus capable of continuing conveyance of sheets without causing a jam even when a switching member performs an operation for switching a conveyance path again. A switching member is disposed at a branching point of a conveyance path through which the sheet is conveyed by a conveying unit, and is operated by a drive unit for witching a destination of conveyance of the sheet. A controller causes the drive unit to operate the switching member, and performs a checking operation for checking a state of the drive unit based on an output from a sensor that detects a state of the switching member. The controller controls a sheet conveyance interval between a first sheet conveyed by the conveying unit and a second sheet conveyed following the first sheet, according to a result of the checking operation.

A document conveyance apparatus includes a document conveyance section, a cover, an opening and closing detection sensor, a document detection sensor, and a control section. The control section detects opening and closing of the cover on the basis of an output value of the opening and closing detection sensor and detects whether or not there is a document in a predetermined detection position on the basis of the output value of the document detection sensor. If, when the output value of the document detection sensor has changed from a value indicating an opened state of the cover to a value indicating a closed state thereof, the output value of the document detection sensor is a value indicating that there is the document, the control section detects a half-closed state where the cover is not completely closed.

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.

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.

Provided is a paper transporting device and the like capable of suppressing errors in determining jam occurrences. A paper transporting device has: a transport mechanism; an audio signal output unit that outputs an audio signal according to the sound generated during paper transport; an audio jam determination unit that determines, on the basis of the audio signal, whether a jam has occurred; and a control unit that stops paper transport when the audio jam determination unit determines that a jam has occurred. The control unit controls, in the case of card stock or paperboard being transported by the transport mechanism, so that the audio jam determination unit determines whether a jam has occurred at predetermined times using a determination method that is different than the method at other times or so that the audio jam determination unit does not determine whether a jam has occurred.