A scanner includes a reading unit that reads an image of a paper, a medium feeding portion that is capable of selecting a first feeding mode in which a separation feeding for separately feeding a paper bundle in which a plurality of sheets of paper is overlapped with each other is performed and a second feeding mode in which a non-separation feeding for collectively feeding the paper bundle without separating is performed, and a pair of first transporting rollers and a pair of second transporting rollers that transport the paper fed by the medium feeding portion, in a case in which the medium feeding portion feeds the paper in the second feeding mode, a first driven roller and a second driven roller respectively constituting the pair of first transporting rollers and the pair of second transporting rollers are driven in a rotation direction where the paper is transported.

A sheet processing device separates a two-ply sheet in which two sheets are overlapped and partially bonded and sandwich a sheet medium between the two sheets. The sheet processing device includes a relay conveyance path, a sheet loader, and control circuitry. The sheet medium is fed from an image forming apparatus connected upstream of the sheet processing device through the relay conveyance path. The sheet loader loads at least one of the two-ply sheet and the sheet medium. The control circuitry performs a mixing mode to feed the two-ply sheet or the sheet medium from the sheet loader.

A sheet processing apparatus is configured to sandwich one or more sheet media in a two-ply sheet in which two sheets are overlaid and bonded together at a portion of the two-ply sheet. The sheet processing apparatus includes circuitry configured to control insertion processing to insert the one or more sheet media into the two-ply sheet based on a length of the two-ply sheet in a conveyance direction, a length of one of the one or more sheet media in the conveyance direction, and a number of the one or more sheet media.

A sheet separation device separates a non-bonding portion of a two-ply sheet in which two sheets are overlapped and bonded together at a bonding portion of the two-ply sheet. The sheet separation device includes a winding roller and a gripper. The winding roller rotates and winds the two-ply sheet to separate the two-ply sheet. The gripper is disposed in the winding roller and configured to grip a gripped portion of the two-ply sheet at one end of the two-ply sheet without abutting a tip of the gripped portion at the one end of the two-ply sheet on a member.

A sheet processing device sandwiches a sheet-shaped medium in a two-ply sheet in which two sheets are overlaid and partially bonded. The sheet processing device includes a separator, a conveyor, and a switching member. The separator separates the two sheets of the two-ply sheet. The conveyor is disposed downstream from the separator in a sheet conveyance direction and conveys the two-ply sheet. The switching member is disposed downstream from the conveyor in the sheet conveyance direction. The switching member switches a conveyance path of the two-ply sheet to convey the two-ply sheet to a fixing path on which fixing processing is performed on the two-ply sheet or a non-fixing path on which no fixing processing is performed on the two-ply sheet.

A sheet processing device separates a two-ply sheet in which two sheets are overlapped and partially bonded and sandwich a sheet medium between the two sheets. The sheet processing device includes a relay conveyance path, a sheet loader, and control circuitry. The sheet medium is fed from an image forming apparatus connected upstream of the sheet processing device through the relay conveyance path. The sheet loader loads at least one of the two-ply sheet and the sheet medium. The control circuitry performs a mixing mode to feed the two-ply sheet or the sheet medium from the sheet loader.

A sheet separation device separates a non-bonding portion of a two-ply sheet in which two sheets are overlapped and bonded together at a bonding portion of the two-ply sheet. The sheet separation device includes a separator, an abnormality detection device, and circuitry. The separator is configured to move to be inserted into a gap formed between the two sheets of the two-ply sheet. The abnormality detection device is configured to detect an abnormal state in which the gap larger than a predetermined size is not formed between the two sheets before the separator is inserted into the gap. The circuitry is configured to control movement of the separator based on a result detected by the abnormality detection device.

A sheet processing device sandwiches a sheet-shaped medium in a two-ply sheet in which two sheets are overlaid and partially bonded. The sheet processing device includes a separator, a conveyor, and a switching member. The separator separates the two sheets of the two-ply sheet. The conveyor is disposed downstream from the separator in a sheet conveyance direction and conveys the two-ply sheet. The switching member is disposed downstream from the conveyor in the sheet conveyance direction. The switching member switches a conveyance path of the two-ply sheet to convey the two-ply sheet to a fixing path on which fixing processing is performed on the two-ply sheet or a non-fixing path on which no fixing processing is performed on the two-ply sheet.

A sheet processing apparatus is configured to sandwich one or more sheet media in a two-ply sheet in which two sheets are overlaid and bonded together at a portion of the two-ply sheet. The sheet processing apparatus includes circuitry configured to control insertion processing to insert the one or more sheet media into the two-ply sheet based on a length of the two-ply sheet in a conveyance direction, a length of one of the one or more sheet media in the conveyance direction, and a number of the one or more sheet media.

A sheet processing device inserts a sheet-shaped medium into a two-ply sheet in which two sheets are overlaid and partially bonded. The sheet processing device includes control circuitry to execute a single insertion mode in which one sheet-shaped medium is inserted into the two-ply sheet and a multiple insertion mode in which a plurality of sheet-shaped media are inserted into the two-ply sheet along a conveyance direction. The control circuitry inserts the one sheet-shaped medium into the two-ply sheet in the single insertion mode and the plurality of sheet-shaped media into the two-ply sheet in the multiple insertion mode, with the two-ply sheet being stopped.