Surface defect inspection apparatus and surface defect inspection method for hot dip galvanized steel sheet

摘要

Classifying and determining multiple types of surface defects with high accuracy without relying on information such as the area and shape of surface defects that are likely to vary. The regular reflection light imaging unit 4 and the irregular reflection light imaging unit 5 simultaneously capture the reflected light from the imaging target site on the steel plate 2. The image signal processing unit 6 extracts a part having a luminance lower than a predetermined threshold as a surface defect part from the regular reflection image signal T1 obtained by imaging by the regular reflection light imaging unit 4. For the part corresponding to the extracted surface defect part, the defect type of the extracted surface defect part is classified by performing threshold processing on the irregular reflection image signal T2 obtained by imaging by the irregular reflection light imaging unit 5 judge.