Sheet folding apparatus and image formation system provided with the apparatus

摘要

A sheet folding apparatus for forming first folding and second folding in a sheet enables the sheet to be folded in an accurate fold position in second folding, when the front end of the sheet which is first folded in a nip position of a first folding roller pair and transported strikes a stopper member, a guide member guides a fold to undergo second folding of the first-folded sheet to a nip position of a second folding roller pair, and second folding is formed.

主权项

1. A sheet folding apparatus for forming a fold in a sheet transported into a transport path, comprising:
a first folding roller pair for forming first folding in a sheet, comprising a first folding roller positioned on an upstream side in a sheet transport direction in the apparatus, and a second folding roller, positioned on a downstream side in the sheet transport direction in the apparatus, in contact with an outer periphery of the first folding roller to rotate in an opposite direction; a folding deflecting member that comes into press-contact with an outer periphery of the second folding roller to guide a fold of the sheet to a nip position of the first folding roller pair; a second folding roller pair for forming second folding in the sheet with the first folding formed, comprising the second folding roller, and a third folding roller in contact with the outer periphery of the second folding roller to rotate in an opposite direction; a stopper member provided to strike, in a predetermined position, a front end of the sheet with the first folding formed; and a guide member movable between an operating position for guiding the sheet with the first folding formed to a nip position of the second folding roller pair and to waiting position retracted from the operating position, the guide member moving towards the nip position of the second folding roller pair to guide the sheet with the first folding formed to form the second folding after the front end of the sheet with the first folding arrives at the stopper member, wherein the guide member is in the waiting position when the sheet that is first folded in the first folding roller pair is transported to the stopper member, and moves to the operating position when the front end of the sheet arrives at the stopper member.