PURPOSE: To obtain a surface flaw inspector with higher reliability in the detec tion of flaws by enabling the detecting of even a small flaw with a smaller width.
CONSTITUTION: This apparatus is made up of a transmitting system in which a laser light 5 is focused onto a surface 9 to be inspected to perform a scanning 10 in one direction and a photodetecting system which detects scattered light 11 as reflected from the surface 9 to be inspected to judge the presence of a flaw from the intensity of the scattered light 11. Laser light sources 1a and 1b, a combiner 4, a condeser lens 6 and a vibration mirror 8 are arranged to use a laser light 2a with a wavelength λ, and a laser light 2b with a wavelength λ2 so that it irradiates the surface to be inspected as one laser light 5 and a bundle fiber 14, a dichroic mirror 15, and optoelectrical transducers 19a and 19b to receive the scattered light 11 with wavelengths λ1 and λ2 separately and an arithmetic device 22 to obtain a correlation of scattered light signals 20a and 20b gained from the wavelengths λ1 and λ2 so that the presence of a flaw is judged from a correlation function thereof.
ETSU MIYUKI
HORI JUNICHIRO
KAWAHARA KENICHI
FUKADA SEI
