Patent ID: 8052137

Claim:
A sheet stopping mechanism of an automatic document feeder, said automatic document feeder comprising a sheet input tray and a sheet pick-up roller, at least one paper sheet being placed on said sheet input tray, said sheet stopping mechanism comprising: a guiding element comprising a sheathing part and an extension arm, wherein said sheathing part is sheathed around an axle of said sheet pick-up roller; a sheet stopping element comprising a stopping part, at least one protrusion part and a contact part, wherein said extension arm of said guiding element is upwardly sustained against at said contact part of said sheet stopping element; and at least one guiding slot for accommodating said at least one protrusion part of said sheet stopping element, wherein said guiding slot is a profiled slot comprising a linear part and a curved part; wherein when said sheet pick-up roller is moved toward said sheet input tray, said guiding element is uplifted through the transmission of said sheathing part and said sheet pick-up roller, so that said protrusion part of said sheet stopping element is shifted and rotated in said guiding slot, and a front edge of said paper sheet is no longer hindered by said stopping part of said sheet stopping element but permitted to be transported into a sheet-guiding path.