A sheet separation device separates a non-bonding portion of a two-ply sheet in which two sheets are overlapped and bonded together at one end of the two-ply sheet. The sheet separation device includes a separator that includes a first separator and a second separator. The first separator is inserted into a gap between the two sheets of the two-ply sheet. The second separator is inserted between the two sheets at said another end of the two-ply sheet that is opposite to the one end of the two-ply sheet and moves in a width direction of the two-ply sheet after the first separator is inserted into the gap and relatively moves from the one end to said another end.

A sheet separation device separates a non-bonding portion of a two-ply sheet in which two sheets are overlapped and bonded together at one end of the two-ply sheet. The sheet separation device includes a separator that includes a first separator and a second separator. The first separator is inserted into a gap between the two sheets of the two-ply sheet. The second separator is inserted between the two sheets at said another end of the two-ply sheet that is opposite to the one end of the two-ply sheet and moves in a width direction of the two-ply sheet after the first separator is inserted into the gap and relatively moves from the one end to said another end.

A sheet separation device separates a non-bonding portion of a two-ply sheet in which two sheets are overlapped and bonded together at one end of the two-ply sheet. The sheet separation device includes a separator that includes a first separator and a second separator. The first separator is inserted into a gap between the two sheets of the two-ply sheet. The second separator is inserted between the two sheets at said another end of the two-ply sheet that is opposite to the one end of the two-ply sheet and moves in a width direction of the two-ply sheet after the first separator is inserted into the gap and relatively moves from the one end to said another end.

A sheet separation device separates a non-bonding portion of a two-ply sheet in which two sheets are overlapped and bonded together at one end of the two-ply sheet. The sheet separation device includes a separator that includes a first separator and a second separator. The first separator is inserted into a gap between the two sheets of the two-ply sheet. The second separator is inserted between the two sheets at said another end of the two-ply sheet that is opposite to the one end of the two-ply sheet and moves in a width direction of the two-ply sheet after the first separator is inserted into the gap and relatively moves from the one end to said another end.

A sheet behavior monitor for a sheet processor includes: a folding machine processing a sheet; and a camera taking an image once for each signature (Wb) folded by the folding machine. The camera takes every image at a folding machine rotation phase different from that of the image immediately before taken.

A sheet bundle discharging apparatus including: a conveyance belt configured to convey and discharge a sheet bundle in a conveyance direction; an attitude changing unit configured to change an attitude of the sheet bundle from a first attitude in which the sheet bundle is apart from the conveyance belt to a second attitude in which the sheet bundle is placed on the conveyance belt; and a receiving member configured to receive an end portion of the sheet bundle, wherein the attitude changing unit allows the end portion of the sheet bundle to pass through a region in which the conveyance belt is provided, in a belt width direction perpendicular to the conveyance direction, and thereafter reach a region in which the receiving member is provided, a friction coefficient between the sheet bundle and the receiving member being smaller than a friction coefficient between the sheet bundle and the conveyance belt.

A sheet separation device separates a non-bonding portion of a two-ply sheet in which two sheets are overlapped and bonded together at one end of the two-ply sheet. The sheet separation device includes a separator that includes a first separator and a second separator. The first separator is inserted into a gap between the two sheets of the two-ply sheet. The second separator is inserted between the two sheets at said another end of the two-ply sheet that is opposite to the one end of the two-ply sheet and moves in a width direction of the two-ply sheet after the first separator is inserted into the gap and relatively moves from the one end to said another end.

A sheet separation device separates a non-bonding portion of a two-ply sheet in which two sheets are overlapped and bonded together at one end of the two-ply sheet. The sheet separation device includes a separator that includes a first separator and a second separator. The first separator is inserted into a gap between the two sheets of the two-ply sheet. The second separator is inserted between the two sheets at said another end of the two-ply sheet that is opposite to the one end of the two-ply sheet and moves in a width direction of the two-ply sheet after the first separator is inserted into the gap and relatively moves from the one end to said another end.

A sheet bundle discharging apparatus including: a conveyance belt configured to convey and discharge a sheet bundle in a conveyance direction; an attitude changing unit configured to change an attitude of the sheet bundle from a first attitude in which the sheet bundle is apart from the conveyance belt to a second attitude in which the sheet bundle is placed on the conveyance belt; and a receiving member configured to receive an end portion of the sheet bundle, wherein the attitude changing unit allows the end portion of the sheet bundle to pass through a region in which the conveyance belt is provided, in a belt width direction perpendicular to the conveyance direction, and thereafter reach a region in which the receiving member is provided, a friction coefficient between the sheet bundle and the receiving member being smaller than a friction coefficient between the sheet bundle and the conveyance belt.

An image forming apparatus includes an image forming unit to form an image on a sheet, an intermediate processing tray where sheets conveyed through a first conveyance path are stacked as a sheet bundle, a sensor disposed at a second conveyance path to detect a conveyed sheet bundle, and a stacking tray in which sheets discharged through a discharging path diverging from the first conveyance path are stacked. In response to a sensor detected paper jam, a control unit determines the intermediate processing tray as the discharging destination for a sheet among the remaining sheets, and determines the stacking tray as the discharging destination for a sheet among the remaining sheets. After the paper jam is cleared, the control unit causes execution of bookbinding and cutting for a sheet bundle including the remaining sheets stacked in the intermediate processing tray.