SHEET STORAGE DEVICE, AND POST-PROCESSING DEVICE AND IMAGE FORMING SYSTEM USING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a sheet storage device capable of reliably conveying a sheet, even in either paper discharge mode of carrying out a sheet on sheets stacked on a processing tray from a paper discharge port and of discharging the sheet to a stack tray, and eliminating the occurrence of problems such as ink friction of an image sheet and fouling.SOLUTION: In a paper discharge port, an upper roller engaging with a sheet top surface and a lower roller engaging with a sheet lower surface are disposed to be brought into press-contact and separation with each other. The upper roller is constituted of a flexible roll surface of a large diameter and a hard roll surface of a small outer diameter, and also a pressing force of roller lifting means for bringing the upper roller into press-contact and separation with the lower roller is changed into a large and small magnitude.