US 12,461,026 B2
Optical inspection method, non-transitory storage medium storing optical inspection program, processing device, and optical inspection apparatus
Hiroshi Ohno, Tokyo (JP); Hiroya Kano, Kawasaki Kanagawa (JP); Hideaki Okano, Yokohama Kanagawa (JP); and Takahiro Kamikawa, Tokyo (JP)
Assigned to Kabushiki Kaisha Toshiba, Kawasaki (JP)
Filed by KABUSHIKI KAISHA TOSHIBA, Tokyo (JP)
Filed on Sep. 1, 2022, as Appl. No. 17/823,957.
Claims priority of application No. 2022-045295 (JP), filed on Mar. 22, 2022.
Prior Publication US 2023/0304929 A1, Sep. 28, 2023
Int. Cl. G01N 21/47 (2006.01); G01N 21/25 (2006.01); G01N 21/27 (2006.01)
CPC G01N 21/4738 (2013.01) [G01N 21/255 (2013.01); G01N 21/27 (2013.01)] 12 Claims
OG exemplary drawing
 
1. An optical inspection method comprising:
acquiring an image by capturing the image with an image sensor, using light from a surface of an object in such a manner as to make the light enter a wavelength selection portion configured to selectively pass light components of a plurality of predetermined wavelengths different from each other, and then to allow the light components of the plurality of predetermined wavelengths that have selectively passed through the wavelength selection portion to enter an imaging optical element configured to collect the light from one point of the surface of the object onto a conjugate image point on the image sensor,
the wavelength selection portion being configured to color the light in accordance with a scattering angle at the surface of the object, the light including at least one of scattering light and/or specularly reflected light,
the image sensor including color channels configured to discriminately receive the light components of the plurality of predetermined wavelengths,
performing color count estimation processing to estimate, as the number of colors, the number of channels of the color channels that have received the light in each pixel of the image, and
performing at least one of scattered light distribution identification processing to identify a scattered light distribution as Bidirectional Reflectance Distribution Function (BRDF) from the surface of the object based on the number of colors and surface state identification processing to identify a state of the surface of the object based on the number of colors.