Decurling device and image forming apparatus including the same

A decurling device provided on a downstream side with respect to a fixing device in a medium transporting direction and straightening a curl formed in a medium transported to the decurling device, the decurling device comprising:

• a bending unit extending across the medium transporting direction and having a guiding surface that guides a leading end of the medium, the leading end coming into contact with the guiding surface, the bending unit bending the medium in a decurling direction by using the guiding surface;
• an urging spring that urges the bending unit toward the medium;
• a single or a plurality of rotating members provided on a part of the guiding surface of the bending unit and rotating by coming into contact with the medium that is in contact with the guiding surface, and
• a transporting unit that is provided between the fixing device and the bending unit and that transports the medium while nipping the medium, wherein the transporting unit includes a plurality transporting rollers,
• wherein the bending unit is provided on the downstream side with respect to the transporting unit in the medium transporting direction,
• wherein the rotating member is positioned in contact with the transporting unit, and,
• wherein if the medium is a thick medium having a thickness greater than or equal to a predetermined threshold, the guiding surface of the bending unit is retracted against the urging force of the urging unit in such a manner as to follow a movement of the medium, and
• if the medium is a thin medium having a thickness smaller than the predetermined threshold, the guiding surface of the bending unit is retained at a predetermined position.