Sheet folding device, post-processing device, and image forming system

摘要

Provided is a sheet folding device including a folding roll that has a convex portion spirally provided on an outer periphery surface and is rotatably provided, and performs a folding process while pressing the convex portion on a sheet, and a phase change unit that makes a phase of the folding roll when the sheet on which the folding process is performed by the folding roll passes through the folding roll again different from a phase when the sheet passes through the folding roll for the last time.

主权项

1. A sheet folding device comprising:
a folding roll that has a convex portion spirally provided on an outer periphery surface and is rotatably provided, and performs a folding process on a sheet while pressing a pressing portion of the convex portion on the sheet; a phase change unit that changes from a first phase of the folding roll during which the sheet on which the folding process is performed by the folding roll passes through the folding roll a first time to a second phase during which the sheet passes through the folding roll for a second time, such that a first pressed position on the sheet by the convex portion in the first phase is different from a second pressed position on the sheet by the convex portion in the second phase; a transport portion that transports the sheet to the folding roll the second time after the sheet on which the folding process is performed by the folding roll is pulled back to an upstream side from the folding roll in a transporting direction; and a drive portion that supplies a driving force of the folding roll and the transport portion, wherein the transport portion rotates in one direction while receiving drive by the drive portion and rotates in a direction opposite to the one direction while receiving the drive by the drive portion after pulling back the sheet on which the folding process is performed by the folding roll on the upstream side in the transporting direction, and transports the sheet to the folding roll, and wherein the phase change unit does not transmit the drive from the drive portion to the folding roll when the drive portion rotates the transport portion in the one direction, and transmits the drive from the drive portion to the folding roll when the drive portion rotates the transport portion in the opposite direction.