Examples of stalling of operation of imaging devices are described herein. In an example, the imaging device includes an input roller assembly to transport a medium in the imaging device and a line feed roller assembly disengagably coupled to the input roller assembly to selectively drive the input roller assembly. To stall the operation of the imaging device, a line feed shaft of the line feed roller assembly can be automatically disengaged from the input roller assembly to discontinue advance of the medium along a print path.

An image reading apparatus according to an embodiment includes a first sensor, a roller, a correction unit, a second sensor, a control unit, and a scanner. Upstream to downstream positions with regard to a transportation direction of the sheet are determined in the following order: the first position, a second position, a third position. The first sensor detects the presence or absence of a fold of the sheet in the first position. If it is detected in the first position that the fold is present, the roller transports a sheet in a reverse transportation direction. The correction unit corrects the fold in the first position. The second sensor detects the presence or absence of the fold in the second position. If it is detected in the second position that the fold is present, the control unit controls drive of the roller in such a manner that the sheet is transported up to the first position in the reverse transportation direction. The scanner reads an image on the sheet of which the fold is corrected in the first position.

An image reading apparatus according to an embodiment includes a first sensor, a roller, a correction unit, a second sensor, a control unit, and a scanner. Upstream to downstream positions with regard to a transportation direction of the sheet are determined in the following order: the first position, a second position, a third position. The first sensor detects the presence or absence of a fold of the sheet in the first position. If it is detected in the first position that the fold is present, the roller transports a sheet in a reverse transportation direction. The correction unit corrects the fold in the first position. The second sensor detects the presence or absence of the fold in the second position. If it is detected in the second position that the fold is present, the control unit controls drive of the roller in such a manner that the sheet is transported up to the first position in the reverse transportation direction. The scanner reads an image on the sheet of which the fold is corrected in the first position.

A sheet processing apparatus is described. The sheet processing apparatus includes a housing section, a conveyance mechanism and a controller. The housing section accommodates a sheet. The conveyance mechanism conveys the sheet accommodated in the housing section to a predetermined position at the downstream side in a sheet conveyance direction. The controller controls the conveyance mechanism to remove a needle-free binding section of a sheet bundle if a conveyance jam of the sheet occurs.

A sheet processing apparatus is described. The sheet processing apparatus includes a housing section, a conveyance mechanism and a controller. The housing section accommodates a sheet. The conveyance mechanism conveys the sheet accommodated in the housing section to a predetermined position at the downstream side in a sheet conveyance direction. The controller controls the conveyance mechanism to remove a needle-free binding section of a sheet bundle if a conveyance jam of the sheet occurs.

A sheet feeding device includes a stacking unit for stacking a sheet; a feeding member for feeding the sheet stack on the stacking unit; a holding member holding the feeding member; a holder supporting portion, provided above the stacking unit, for detachably supporting the holding member; a raising and lowering unit for raising and lowering the holding member; a detection unit for detecting a topmost surface of the sheet stacked on the stacking unit, by detecting the holding member; a control unit for effecting raising and lowering operation of the holding member using the raising and lowering unit before a feeding operation of the feeding member and detect presence or absence of the holding member on the basis of a signal from the detection unit produced with the raising and lowering operation.

A sheet feeding device includes a stacking unit for stacking a sheet; a feeding member for feeding the sheet stack on the stacking unit; a holding member holding the feeding member; a holder supporting portion, provided above the stacking unit, for detachably supporting the holding member; a raising and lowering unit for raising and lowering the holding member; a detection unit for detecting a topmost surface of the sheet stacked on the stacking unit, by detecting the holding member; a control unit for effecting raising and lowering operation of the holding member using the raising and lowering unit before a feeding operation of the feeding member and detect presence or absence of the holding member on the basis of a signal from the detection unit produced with the raising and lowering operation.

A document conveyance device includes a feed roller, a separation roller, a first motor for generating a first drive force for driving the separation roller, a planet gear, a drive gear, a second motor for generating a second drive force, and a position switching mechanism for switching a position of the planet gear from a first position in which the planet gear is separated from the drive gear and does not transmit the first drive force to the separation roller to a second position in which the planet gear engages with the drive gear and transmits the first drive force to the separation roller, based on the second drive force. The position switching mechanism includes a support member for supporting the planet gear, and a transfer mechanism for moving the support member so that the planet gear engages with the drive gear, based on the second drive force. The further movement of the planet gear is prevented after the planet gear engaged with the drive gear.

A sheet processing apparatus is described. The sheet processing apparatus includes a housing section, a conveyance mechanism and a controller. The housing section accommodates a sheet. The conveyance mechanism conveys the sheet accommodated in the housing section to a predetermined position at the downstream side in a sheet conveyance direction. The controller controls the conveyance mechanism to remove a needle-free binding section of a sheet bundle if a conveyance jam of the sheet occurs.

A sheet processing apparatus is described. The sheet processing apparatus includes a housing section, a conveyance mechanism and a controller. The housing section accommodates a sheet. The conveyance mechanism conveys the sheet accommodated in the housing section to a predetermined position at the downstream side in a sheet conveyance direction. The controller controls the conveyance mechanism to remove a needle-free binding section of a sheet bundle if a conveyance jam of the sheet occurs.