Inspection system for inspecting the quality of printed sheets

摘要

There is described an inspection system (10) for inspecting the quality of printed sheets being transported by a sheet conveyor system comprising at least one sheet gripper system (3a, 3b) including a plurality of spaced-apart gripper bars (32) for holding the printed sheets by a leading edge thereof. The inspection system (10) is placed along the path of the at least one sheet gripper system (3a, 3b) transporting the printed sheets and comprises an optical quality control apparatus for carrying out inspection of a first side of the printed sheets while the printed sheets are being transported by the sheet gripper system (3b). The optical quality control apparatus includes a line camera (11) for scanning the first side of the printed sheets. The inspection system (10) further comprises a suction roller (50) that is placed in front of the optical path (B) of the line camera (11) along the path (A) of the printed sheets being transported by the sheet gripper system (3b), which suction roller (50) contacts a second side of the printed sheets opposite to the first side which is being scanned by the line camera (11), and a suction box (60) located immediately before the suction roller (50) and cooperating with the second side of the printed sheets for aspirating at least a portion of the second side of the printed sheets against a substantially flat surface (60a) of the suction box (60) before contacting the suction roller (50).