Patent ID: 8353504

Claim:
A sheet folding apparatus comprising: a blade member including an edge configured to push a surface of a sheet so as to push the sheet into a sheet folding unit configured to fold the sheet; a pair of nipping members included in the sheet folding unit, to nip the sheet pushed into the sheet folding unit by the blade member; a blade member moving unit configured to move the blade member between a pushing position where the blade member pushes the sheet into the sheet folding unit and a position retracted from the pushing position; a pressure releasing member configured to be inserted between the pair of nipping members and to be moved away from between the pair of nipping members, the pressure releasing member configured to separate the pair of nipping members if inserted between the pair of nipping members and configured to move the pair of nipping members closer to each other if the pressure releasing member is moved away from between the pair of nipping members; and a nipping member moving unit configured to move the pair of nipping members between a nipping position where the pair of nipping members nip the sheet and a position retracted from the nipping position, the sheet folding apparatus being configured to fold the sheet by nipping the sheet between the pair of nipping members, and the blade member moving unit and the nipping member moving unit being driven by a shared driving unit.