Patent ID: 8243336

Claim:
An image forming apparatus comprising: a first class data memory section that stores a first class data that is common to a sheet to be printed; a second class data memory section that stores the second class data to be embedded in the first class data at the time of printing, the second class data being different from sheet to sheet to be printed; a first unfolding section that unfolds the first class data and the second class data to a first image data; a second unfolding section that unfolds the first class data and the second class data to a second image data, the second unfolding section being different from the first unfolding section; a first image carrier that carries a first image formed by the first image data unfolded by the first unfolding section; a second image carrier that carries a second image formed by the first image data unfolded by the first unfolding section; a transfer medium that is held in contact with the first image carrier and the second image carrier and to which the first image formed on the first image carrier and the second image formed on the second image carrier are transferred; an image pickup section of the image carrier that picks up the first image of the first image carrier and prepares a first picked up image data; an image pickup section of the transfer medium that picks up an image transferred to the transfer medium and prepares a second picked up image data; an image examination section of the image carrier that examines an image corresponding to the second class data by comparing the second image data unfolded by the second unfolding section and the first picked up image data prepared by the image pickup section of the image carrier; and an image examination section of the transfer medium that examines an image corresponding to the first class data by comparing the second image data unfolded by the second unfolding section and the second picked up image data prepared by the image pickup section of the transfer medium.