Sheet creaser, sheet finisher, image forming apparatus, sheet folding method, and computer program product

摘要

In a sheet creaser, a sheet set is pushed between a pair of folding rollers to fold the sheet set. Then, a re-pressing roller re-presses the sheet set, which has been folded by the folding rollers, by rolling along the crease. Pressure applied on the sheet set by the folding rollers is released when the re-pressing roller re-presses the sheet set.