| 摘要 |
PROBLEM TO BE SOLVED: To accurately detect a surface defect of an inspection object.SOLUTION: An imaging device 6 picks up a surface image of a housing W illuminated with light from a first illumination device 51, a luminance of the surface image is compared with a luminance of a non-defective image without a defect for each pixel, and a position of the housing W is corrected so that the luminance of the surface image can match that of the non-defective image. Subsequently, the imaging device 6 picks up a surface image of the housing W at the corrected position while illuminating the housing W with the light from the first illumination device 51, the luminance of the surface image is compared with the luminance of the non-defective image without a defect for each pixel, determines a region low in a degree of matching as a defect, and determines that the housing W is defective if such a defect is present. |
