| 摘要 |
PROBLEM TO BE SOLVED: To surely detect an abnormal missing or abrasion state of chips in any case. SOLUTION: A CCD camera 5 for photographing a bevel-worked face 1a of a steel pipe 1 and a controller 7 for processing an image obtained by the CCD camera 5 are provided. After the state of a good face and a state of a defective face are converted to be at, for instance, a white level and a black level respectively, an instrumentation window is set, e.g. at the central part within a detected instrumentation screen, ad an area ration of the white level reduced by influences of the black level is calculated. The area ratio is compared with a reference area ratio preliminarily set for the state of the good face. When the deviation is not smaller than a predetermined value, the face is judged to be abnormal by the controller 7. |
