INSPECTION METHOD FOR PRINTED MATTER

摘要

PURPOSE:To obtain an inspection method for a printed matter by which the defect of the printed matter can be correctly detected in an in-line system, and the edge part that has been an uninspectable area in a prior art can be inspected. CONSTITUTION:Image pattern information of a printed matter fed from a printing part 1 is received by a detection part 4 per pixel in accordance with a sampling timing obtained from a rotary encoder 5 to be inputted to a processing circuit 6. The processing circuit 6 receives image pattern information of a normal printed matter, forms an image thereform, and filters it through a minimum value filter and/or a maximum value filter to form a reference image. A difference value is found by comparing this image with an image to be inspected. A defect is detected by comparing the difference value with an allowable value (a threshold).