Image-forming device and image-forming method

An image-forming device capable of image-forming on both sides of a sheet comprising:

• an image-forming unit configured to form an image on the sheet;
• a sheet supplying unit configured to supply the sheet;
• an image-forming control unit configured to control, according to print job information transmitted from an image data processing unit, image-forming operations on the sheet;
• an image data processing unit configured to transmit the print information to the image-forming control unit;
• and wherein, in the event that the sheet is not supplied from the sheet supplying unit during image formation on both sides of the sheet in accordance with the print information,
• the image-forming control unit transmits information corresponding to the unsupplied sheet to the image data processing unit, temporarily stops an image forming operation on a sheet that stays in the image-forming device, and executes a post-processing operation of the image-forming unit, wherein the image data processing unit edits the print information using the information corresponding to the unsupplied sheet transmitted from the image-forming control unit and retransmits the edited print information to the image-forming control unit, and wherein the image-forming control unit restarts image-forming operations on the sheet that stays in the image-forming device on the basis of the print information retransmitted from the image data processing unit.