Copier with bookbinding function

A copier having a function of binding copy papers, comprising:

• a copying device including an inverting mechanism for inverting the copy papers each carrying a copied image on the face thereof, and an intermediate tray for temporarily storing said copy papers to prepare for duplication on the other faces of the copy papers;
• a recirculation type document handling device including a document tray for accommodating documents, and an inverting mechanism neighboring a glass platen of said copying device, said document handling device returning the documents fed out of said document tray back to the document tray after both faces, if necessary, of the documents have been illuminated by the copying device;
• and
• a bookbinding device conjugate with a transport path along which the copy papers are discharged from the copying device, said bookbinding device including a folding mechanism for creasing each of the copy papers at a central portion, and a binding mechanism conjugate with said folding mechanism.