Sheet storage apparatus and image formation system using the apparatus

A sheet storage apparatus comprising:

• a placement tray to load a sheet fed from a sheet discharge outlet;
• a take-in rotating body disposed on the placement tray to guide the sheet fed from the sheet discharge outlet to a predetermined position on the tray;
• a support member that supports the take-in rotating body swingably to engage in an uppermost sheet;
• alignment means for width-shifting and aligning the sheet fed in by the take-in rotating body in a sheet-discharge orthogonal direction;
• and
• a paper-pressing guide having a paper-pressing surface for pressing a top surface of the sheet on the placement tray,
• wherein the paper-pressing guide is supported by an apparatus frame swingably so as to float upward from the sheet corresponding to a curl of the sheet on the placement tray, and
• when the paper-pressing surface floats a predetermined amount or more from the top surface of the sheet on the placement tray, the paper-pressing guide engages in the support member to move upward integrally with the take-in rotating body.