Inspection System for a Sheet-Fed Recto-Verso Printing Press

There is described a sheet inspection system for a sheet-fed recto-verso printing press of the type comprising two printing cylinders (10, 20) for carrying out simultaneous recto-verso printing of the sheets, said sheet inspection system comprising at least one inspection device (200; 300; 400) for taking an image of one side of the printed sheets. The sheet inspection system comprises first and second transfer cylinders (60, 65) interposed between a first (10) of the two printing cylinders (10, 20) and a chain gripper system (5) of the printing press, printed sheets being transferred successively from the first printing cylinder (10) to the first transfer cylinder (60), to the second transfer cylinder (65), and to the chain gripper system (5). The inspection device (200; 300; 400) comprises a line image sensor (210; 310; 410) for performing line-scanning image acquisition of the one side of the printed sheets, this line image sensor (210; 310; 410) visually acquiring an image of a printed sheet while the printed sheet is being transported on the first or second transfer cylinder (60; 65).