CORRECTION OF POSITIONAL DEVIATION

摘要

PURPOSE:To achieve a highly reliable image processing inspection for the inspection of a long-sized object by detecting a positional displacement of an object to be inspected with a mark for positional correction and a window for positional correction to dislocate an inspection window according to a positional displacement thus obtained. CONSTITUTION:An image signal obtained with a camera 3 is taken into an image processor 4 starting from the detection of a reflecting tape 11 with an optical switch 12 as a drawing board 2 is being fed in a direction A. At this point, when a mark 10 for positional correction is displaced with a positional deviation of the drawing board 2, the position of a mark image 10' for positional correction flowing crossing a window 20 for positional correction is displaced downward on a screen. When this displacement is identified, an inspection window 21 is shifted downward automatically to the same extent as the displacement of the image 10'. Thus, an object to be inspected is placed accurately in a data within an area surrounded by a window 21 free from a deviation in a direction B, thereby enabling accurate inspection.