Image forming apparatus and sheet stacking device with lifter

Abstract

A sheet stacking device including a stacking tray for stacking and containing sheets, and a lifting and lowering device for moving the staking tray up and down. In this case, the lifting and lowering device includes a driving force converting device for changing the distance of moving the stacking tray as an input and output ratio with respect to a predetermined driving force from a driving source, and changing the elevating speed of the stacking tray according to the input and output ratio. The driving force converting device includes a suspension member for suspending the stacking tray and a winding member having a conical winding portion for winging the suspension member, and lifts and lowers the stacking tray by rotating the winding member, and the elevating speed of the stacking tray is changed according to the winding length of the suspension member, which is changed depending on the diameter difference of the winding portion.

Dependencies are inferred from the claim text.