Optical inspection method, non-transitory storage medium, and optical inspection apparatus
According to an embodiment, an optical inspection method includes: causing a wavelength selection portion to selectively pass light components including at least two different wavelength spectra from an object point and causing an imaging portion including at least two color channels configured to receive the light components of the wavelength spectra to capture the object point; defining the light components of the at least two different wavelength spectra as signal vectors having different directions based on light reception data in the at least two color channels for the object point; and estimating spread of a direction distribution of light at the object point based on the directions of the signal vectors.
1 . An optical inspection method comprising:
causing a wavelength selection portion to selectively pass light components including at least two different wavelength spectra from an object point and causing an imaging portion including at least two color channels configured to receive the light components of the wavelength spectra to capture the object point;
defining the light components of the at least two different wavelength spectra as signal vectors having different directions based on light reception data in the at least two color channels for the object point; and
estimating spread of a direction distribution of light at the object point based on the directions of the signal vectors,
wherein:
the wavelength selection portion includes:
a first set in which a plurality of wavelength selection regions different from each other are arranged; and
a second set in which the plurality of wavelength selection regions are arranged in the same array as the first set, and
the wavelength selection portion introduces a periodic background noise component into a captured image.
2 . The optical inspection method according to claim 1 , wherein the signal vectors are vectors having, as an end point, a point on a color coordinate space on which pixel values of the at least two color channels are plotted on coordinates orthogonal to each other.
3 . The optical inspection method according to claim 1 , wherein the estimating includes collating a captured image by the light reception data with a reference image and estimating the spread of the direction distribution of the light at the object point.
4 . The optical inspection method according to claim 1 , wherein the wavelength selection portion is positioned closer to the object point than the imaging portion.
5 . A non-transitory storage medium storing an optical inspection program configured to cause a computer to execute:
causing a wavelength selection portion to selectively pass light components including at least two different wavelength spectra from an object point and causing an imaging portion including at least two color channels configured to receive the light components of the wavelength spectra to capture the object point;
defining the light components of the at least two different wavelength spectra as signal vectors having different directions based on light reception data in the at least two color channels for the object point; and
estimating spread of a direction distribution of light at the object point based on the directions of the signal vectors,
wherein:
the wavelength selection portion includes:
a first set in which a plurality of wavelength selection regions different from each other are arranged; and
a second set in which the plurality of wavelength selection regions are arranged in the same array as the first set, and
the wavelength selection portion introduces a periodic background noise component into a captured image.
6 . The non-transitory storage medium according to claim 5 , wherein the wavelength selection portion is positioned closer to the object point than the imaging portion.
7 . An optical inspection apparatus comprising one or more processors configured to read out the optical inspection program defined in claim 5 from the non-transitory storage medium and execute the optical inspection program.
8 . An optical inspection apparatus comprising one or more processors configured to
cause a wavelength selection portion to selectively pass light components including at least two different wavelength spectra from an object point and cause an imaging portion including at least two color channels configured to receive the light components of the wavelength spectra to capture the object point;
define the light components of the at least two different wavelength spectra as signal vectors having different directions based on light reception data in the at least two color channels for the object point; and
estimate spread of a direction distribution of light at the object point based on the directions of the signal vectors,
wherein:
the wavelength selection portion includes:
a first set in which a plurality of wavelength selection regions different from each other are arranged; and
a second set in which the plurality of wavelength selection regions are arranged in the same array as the first set, and
the wavelength selection portion introduces a periodic background noise component into a captured image.
9 . The optical inspection apparatus according to claim 8 , further comprising an optical system configured to make the signal vectors corresponding to the light components of the at least two different wavelength spectra linearly independent of each other.
10 . The optical inspection apparatus according to claim 8 , further comprising:
the imaging portion including the color channels controlled by the one or more processors;
the wavelength selection portion configured to selectively pass the light components including the at least two different wavelength spectra from the object, the wavelength selection portion being provided between the object point and the imaging portion; and
a shielding portion configured to shield light that is configured to be captured without passing through the wavelength selection portion.
11 . The optical inspection apparatus according to claim 10 , wherein
the first set and the second set of the wavelength selection portion respectively include:
a first wavelength selection region that is configured to shield a light component of at least one wavelength not included in a light component of a first wavelength spectrum and
a second wavelength selection region that is configured to shield a light component of at least one wavelength not included in a light component of a second wavelength spectrum in light components including at least two different wavelength spectra, and
the shielding portion includes a shielding region provided between the first wavelength selection region and the second wavelength selection region and configured to shield the light component of the first wavelength spectrum and the light component of the second wavelength spectrum.
12 . The optical inspection apparatus according to claim 8 , wherein the first set and the second set are arranged on the same surface.
13 . The optical inspection apparatus according to claim 8 , wherein the wavelength selection portion is positioned closer to the object point than the imaging portion.