A sheet binding device includes a sheet shifting unit, a tape cutter, and a tape attachment unit. The sheet shifting unit has a guide and is configured to stack multiple sheets on the guide with edge portions that are shifted from each other to form a sheet bundle. The tape cutter cuts tape with a target length that is varied in accordance with a thickness of the sheet bundle. The tape attachment unit is configured to attach the cut tape having the target length to an edge portion of the sheet bundle.

According to one embodiment, a sheet separator has a first driving roller and a pressing body. The first driving roller rotates about a first rotation shaft. The first driving roller conveys a sheet bundle including a plurality of sheets. The pressing body is capable of approaching the first driving roller. The first driving roller is rotatable in a first direction with the sheet bundle sandwiched between the first driving roller and the pressing body. The pressing body pivots in the first direction about the first rotation shaft with the sheet bundle sandwiched between the first driving roller and the pressing body to cause the plurality of sheets to deviate from one another at edges.

An image forming apparatus includes a first unit, a second unit fixed to the first unit at a portion upstream of the first unit in a conveyance direction in which the sheet is conveyed, and an electric board. In the image forming apparatus, a disposition of the electric board is restricted by the first unit and the second unit.

There is provided a sheet processing apparatus with improved visibility of a sheet bundle discharged without post-processing thereto. The CPU circuit receives the conveyed sheet, drives and controls the sheet-returning paddle, the rack part, the rear end regulation part, the alignment plate and the like and forms sheet bundle comprising of a plural number of sheets as received. Further, the CPU circuit drives and controls the alignment plate when discharging the sheet bundle S from the processing tray, the sheet bundle S exceeding the number of sheets which can be post-processed by the stapler. Therefore, the sheet bundle S which includes sheets equal to the allowable number of sheets for post-processing of the sheet processing unit is discharged to the second discharge position which is different from the first discharge position.

A sheet binding device includes a sheet shifting unit, a tape cutter, and a tape attachment unit. The sheet shifting unit has a guide and is configured to stack multiple sheets on the guide with edge portions that are shifted from each other to form a sheet bundle. The tape cutter cuts tape with a target length that is varied in accordance with a thickness of the sheet bundle. The tape attachment unit is configured to attach the cut tape having the target length to an edge portion of the sheet bundle.

An image forming apparatus includes a main body, a post-printing processing device, and a paper exit part. The main body forms an image on paper. The post-printing processing device is located above the main body and performs post-printing processing on paper. The paper exit part is located on a side surface of the post-printing processing device. Paper is ejected to the paper exit part. The post-printing processing device includes a paper inlet port and a conveyance device. The paper inlet port is located in a rear part of a lower surface of the post-printing processing device. The conveyance device conveys paper conveyed via the paper inlet port into the post-printing processing device in a forward direction thereof to a paper loading tray and conveys the paper therefrom leftward to eject the paper to the paper exit part located on the left side of the post-printing processing device.

A sheet binding method according to an embodiment includes holding a sheet bundle in a state where multiple sheets forming the sheet bundle are shifted relative to each other at an edge portion of the sheet bundle. A pressing region of the edge portion is pressed, in a sheet bundle thickness direction, so that there is substantially no slack along the edge portion. While the sheet bundle is pressed, tape is applied to an edge portion of a sheet bundle at a tape attachment region of the edge portion different from the pressing region.

According to an embodiment, a sheet processing apparatus includes a transport unit and a holding unit. The transport unit transports a first sheet to a first position. The transport unit transports a second sheet, which is transported after the first sheet, to a second position displaced to the upstream side of a sheet transport direction relative to the first position. The transport unit transports a third sheet, which is transported after the second sheet, to a third position displaced to the downstream side of the sheet transport direction relative to the second position. In the case where the second sheet is transported to the second position, the holding unit holds the first sheet at the first position. In the case where the third sheet is transported to the third position, the holding unit holds the second sheet at the second position.

A sheet transport apparatus according to an embodiment includes a roller having a surface formed from an elastic material. The roller transports a sheet. A rotation mechanism rotated the roller around an axis of the roller. A twist mechanism selectively twists the roller with respect to the axis. When the roller is twisted and the rotation mechanism rotates the roller, a sheet transported by the roller is transported in a first direction perpendicular to the axis and in a second direction parallel to the axis. When the roller is not twisted and the rotation mechanism rotates the roller, a sheet transported by the roller is transported in the first direction and not in the second direction.

A sheet conveyance device includes first and second discharge portions to discharge sheets, first and second stacking portions on which sheets are to be stacked, and a control unit to control the second stacking portion to move between a first position and a second position. The first position is that a downstream side of the second stacking portion is positioned and inclined upwardly with respect to an upstream side of the second stacking portion in a sheet conveyance direction of the sheets discharged from the second discharge portion. The second position is that the downstream side of the second stacking portion is positioned on a lower side of the first position of the downstream side of the second stacking portion.