| 摘要 |
PURPOSE:To surely decide the operation abnormality of a photoirradiating means or photoelectric detectors. CONSTITUTION:A light scattering means 20 is installed on nearly the same plane as the plane of a surface to be inspected and the scattered light from a light scattering means 20 by the photoirradiating means 30 is detected by the photoelectric detecting means 7, 8 to decide the abnormality in the operation of at least either of the photoirracliating means 30 or the photoelectric detecting means 7, 8, by which the operations of the photoirradiating means 30 or the photoelectric detecting means 7, 8 are checked surely at need. |
