SHEET FOLDING DEVICE AND IMAGE FORMING SYSTEM

PROBLEM TO BE SOLVED: To perform high accurate folding by preventing the generation of deviation of a folding width and wrinkles, even when sheet folding thickness becomes thick without generating turn-up and tear, etc. at a distal end of folded-up sheet, regardless of the size, a folding way and thickness of the sheet. SOLUTION: This sheet folding device includes first and second folding roller pairs 3 and 4 for folding the sheet 8, a conveying roller pair 1 for feeding the sheet 8 to the folding roller pairs 3 and 4, a sheet guide member 2 for switching a folding direction of the sheet 8 conveyed on the conveying roller pair 1, and a sheet lower surface guide 5 for guiding the sheet 8 guided by the sheet guide member 2 to the first or second folding roller pair 3 or 4. The sheet folding device includes a height adjusting mechanism 10 for adjusting the interval of the first or second folding roller pair 3 or 4 and advancing positions of the sheet 8 into the folding roller pairs 3 and 4 by changing the height of the sheet lower surface guide 5. COPYRIGHT: (C)2011,JPO&INPIT