According to an embodiment, a stacking apparatus includes: a first precedent-stage conveyor unit that conveys first sheets; a second precedent-stage conveyor unit that conveys second sheets; a merging unit that guides, to a merge point, the first sheets output from the first precedent-stage conveyor unit and guides, to the merge point, the second sheets output from the second precedent-stage conveyor unit; a subsequent-stage conveyor unit that sequentially receives, at the merge point, the conveyed first sheets and the conveyed second sheets, and conveys the received first sheets and the received second sheets in order of the reception while lining up in a conveying direction; and a stacking unit that sequentially catches each of the first sheets and each of the second sheets and stacks, at a predetermined position, each of the first sheets and each of the second sheets in order of the catch.

According to an embodiment, a stacking apparatus includes: a first precedent-stage conveyor unit that conveys first sheets; a second precedent-stage conveyor unit that conveys second sheets; a merging unit that guides, to a merge point, the first sheets output from the first precedent-stage conveyor unit and guides, to the merge point, the second sheets output from the second precedent-stage conveyor unit; a subsequent-stage conveyor unit that sequentially receives, at the merge point, the conveyed first sheets and the conveyed second sheets, and conveys the received first sheets and the received second sheets in order of the reception while lining up in a conveying direction; and a stacking unit that sequentially catches each of the first sheets and each of the second sheets and stacks, at a predetermined position, each of the first sheets and each of the second sheets in order of the catch.

A medium conveying apparatus includes a floating sensor located on an upstream side of a first roller in the medium conveying direction to detect a floating of the medium placed on a medium tray, a skew sensor located on a downstream side of a second roller in the medium conveying direction to detect a skew of the medium conveyed by the second roller, and a processor to determine whether the floating of the medium has occurred based on an output signal from the floating sensor, determine whether the skew of the medium has occurred based on an output signal from the skew sensor, and determine that a conveyance abnormality of the medium has occurred when the processor determines that the floating of the medium has occurred and the processor determines that the skew of the medium has occurred.

A medium conveying apparatus includes a floating sensor located on an upstream side of a first roller in the medium conveying direction to detect a floating of the medium placed on a medium tray, a skew sensor located on a downstream side of a second roller in the medium conveying direction to detect a skew of the medium conveyed by the second roller, and a processor to determine whether the floating of the medium has occurred based on an output signal from the floating sensor, determine whether the skew of the medium has occurred based on an output signal from the skew sensor, and determine that a conveyance abnormality of the medium has occurred when the processor determines that the floating of the medium has occurred and the processor determines that the skew of the medium has occurred.

A sheet feeding apparatus includes a detection unit provided to be movable with respect to a sheet stacking portion and configured to detect a sheet by causing a contact portion to come into contact with an uppermost sheet stacked on a stacking surface, wherein a bottom portion of the sheet stacking portion forms a part of a bottom portion of the sheet feeding apparatus, the sheet stacking portion is provided with a through hole configured to be expose in the case where no sheet is stacked on the stacking surface, the through hole penetrating the stacking surface to a bottom surface of the sheet stacking portion, and the contact portion is positioned inside the through hole in the case where no sheet is stacked on the stacking surface.

Each of the sheets is conveyed by a horizontal conveyance unit in a state of being overlapped with a next sheet from above. Each of the sheets is conveyed out of the horizontal conveyance unit in a state of being folded along a fold line with the fold line oriented upward, the fold line extending in a conveyance direction of the horizontal conveyance unit. An oblique conveyance unit receives the sheet from the horizontal conveyance unit and successively conveys the sheets in an oblique downward direction. A sensor is arranged to detect passage of the sheets at a position where steps pass. Each of the steps is formed by two sheets adjacent to each other diverted to the oblique downward direction by the oblique conveyance unit.

Each of the sheets is conveyed by a horizontal conveyance unit in a state of being overlapped with a next sheet from above. Each of the sheets is conveyed out of the horizontal conveyance unit in a state of being folded along a fold line with the fold line oriented upward, the fold line extending in a conveyance direction of the horizontal conveyance unit. An oblique conveyance unit receives the sheet from the horizontal conveyance unit and successively conveys the sheets in an oblique downward direction. A sensor is arranged to detect passage of the sheets at a position where steps pass. Each of the steps is formed by two sheets adjacent to each other diverted to the oblique downward direction by the oblique conveyance unit.

A medium feeding device includes: a medium mounting section that a medium is mounted; a feeding unit that feeds the medium in a feeding direction; a separation unit that separates the medium with the feeding unit; an operation detection unit that is disposed at a position facing a surface of the medium in the medium mounting section and detects a movement of the medium in the feeding direction; an interval forming unit that forms an interval in the feeding direction between a trailing end of a first medium which is the lowest medium fed among media mounted on the medium mounting section and a trailing end of a second medium which is bound with the first medium and stacked on the first medium; and a control unit that stops feeding of the medium based on a detection interval by a detection value of the operation detection unit.

An image forming apparatus includes: a sheet feeding conveyor that feeds and conveys a recording medium to a conveyance path; an image former that performs image formation on the recording medium; a medium sensor that is disposed on an upstream side of the recording medium from the image former on the conveyance path and measures one or more sheet physical properties regarding the recording medium conveyed; a first hardware processor that determines a type of the recording medium on a basis of the sheet physical properties measured by the medium sensor; a second hardware processor that determines conveyance performance for the recording medium; and a third hardware processor that determines whether or not to perform the image formation on a basis of the conveyance performance in a case where the type of the recording medium determined by the first hardware processor is a type out of product specifications.

In an image forming apparatus, a sheet is guided into a first conveyor path or a second conveyor path selectively when a first cover is in a closed position, and is ejected onto the first cover when the first cover is in an open position. Upon power-up, a controller causes a first conveyor roller to rotate but if the first cover is in the open position, when a sheet sensor detects a sheet, the controller does not cause a second conveyor roller to rotate, and causes a flapper to swing from a first position to a second position, and when a front end of the sheet reaches a position downstream of an upstream end of the flapper in a conveyance direction of the sheet conveyed by the first conveyor roller, the controller causes the flapper to swing from the second position to the first position.