| 摘要 |
PROBLEM TO BE SOLVED: To provide a sheet folding device capable of further reducing the displacement of a second fold.SOLUTION: A sheet folding device performs a second bending treatment and a second folding treatment. In the second bending treatment, after a first fold f1 is formed on a sheet bundle B by performing a first bending treatment and a first folding treatment, only a first folding roller 256a of a pair of folding rollers 256 is rotatably driven in the reverse direction to newly bend the part of the sheet bundle different from the first fold f1 while unfolding the first fold f1. In the second folding treatment, after the second bending treatment, the pair of folding rollers 256 are rotatably driven in the directions reverse to each other at equal speeds to pass the newly bent part C of the sheet bundle B through a folding nip from the outlet to the inlet to provide a second fold on the sheet bundle B. |
