Patent ID: 6997456

Claim:
A sheet processing device comprising: a pair of sheet-conveying rotating members for conveying a sheet; an upper conveying guide provided on the downstream side of said pair of the sheet-conveying rotating members in sheet conveying direction for guiding an upper surface of the sheet conveyed by said pair of sheet-conveying rotating members, said upper conveying guide being shiftable in the vertical direction; a lower conveying guide provided below said upper conveying guide and opposed thereto for guiding a lower surface of the sheet conveyed by said pair of sheet-conveying rotating members and receiving and stacking the sheets; upper guide shifting means for shifting said upper conveying guide; and a sheet lift preventing member being shiftable in the vertical direction in conjunction with the shifting movement of said upper conveying guide; wherein said sheet lift preventing member is shifted to an upper position in spaced relationship to the sheet when a downstream end of said upper conveying guide is shifted downward, and is shifted to a lower position for preventing the sheet from lifting when the downstream end of said upper conveying guide is shifted upward.