CN-122029420-A - Inspection apparatus

Abstract

An inspection device (1) for detecting a foreign object (F) as a transparent body in an object (S) is provided with an irradiation unit (3) for irradiating the object (S) with inspection light (L0) having a plurality of wavelengths, a spectroscopic detection unit (4) for detecting light (L1) from an irradiation position (R) of the inspection light (L0) of the object (S) and outputting a spectroscopic spectrum (D) indicating the brightness of each wavelength at the irradiation position (R), and a determination unit (5) for determining the presence or absence of the foreign object (F) at the irradiation position (R) based on information on the periodicity of the spectroscopic spectrum (D).

Inventors

• KUNIHIKO TSUCHIYA
• Otsuka Xianyi
• MATSUDA SHUN
• Nearly rattan show good fortune

Assignees

• 浜松光子学株式会社

Dates

Publication Date

20260512

Application Date

20240624

Priority Date

20231017

Claims (11)

1. 1. An inspection apparatus, wherein, Is an inspection device for detecting foreign matter as a transparent body in an object, The device is provided with: An irradiation unit that irradiates the object with inspection light having a plurality of wavelengths; A spectroscopic detection unit that detects light from an irradiation position of the inspection light of the object, outputs a spectroscopic spectrum indicating brightness for each wavelength at the irradiation position, and And a determination unit configured to determine whether or not the foreign matter is present at the irradiation position based on the information on the periodicity of the spectroscopic spectrum.
2. 2. The inspection apparatus according to claim 1, wherein, The determination unit performs fourier transform on the spectrum, and determines whether the foreign matter is present at the irradiation position based on comparison between a peak value of intensity after fourier transform and a predetermined threshold value.
3. 3. The inspection apparatus according to claim 2, wherein, The determination unit integrates the luminance of the spectrum in a predetermined wavelength band, and performs fourier transform on the spectrum when the integrated value exceeds a predetermined threshold.
4. 4. The inspection apparatus according to claim 1 to 3, wherein, The wavelength range included in the inspection light is 1000nm or more and less than 2500nm.
5. 5. The inspection apparatus according to claim 1 to 4, wherein, The irradiation section is constituted by linear illumination.
6. 6. The inspection apparatus according to claim 1 to 5, wherein, The illumination section is constituted by dome illumination or flat dome illumination.
7. 7. The inspection apparatus according to claim 1 to 6, wherein, The spectroscopic detection unit is constituted by a multi-wavelength spectrum camera.
8. 8. The inspection apparatus according to claim 1 to 4, wherein, The irradiation section is constituted by linear illumination, The spectroscopic detection unit is constituted by a point spectroscopic detector, A scanner for scanning the detection field of the split-beam detector.
9. 9. The inspection apparatus according to claim 1 to 4, wherein, The illumination portion is constituted by spot-like illumination, The spectroscopic detection unit is constituted by a point spectroscopic detector, A scanner for scanning the irradiation position of the irradiation part and the detection field of the spectroscopic detector.
10. 10. The inspection apparatus according to any one of claim 1 to 9, wherein, The illumination section and the spectroscopic detection section are each provided with a polarizing plate in a parallel nicol relationship.
11. 11. The inspection apparatus according to any one of claim 1 to 10, The apparatus further includes a conveying unit that conveys the object in a predetermined direction.

Description

Inspection apparatus Technical Field The present disclosure relates to inspection devices. Background Conventionally, an inspection apparatus for inspecting the presence or absence of foreign matter in an object by irradiating light to the object is known. As such an inspection apparatus, for example, an inspection apparatus described in patent document 1 is cited. In this conventional inspection apparatus, the transmitted light transmitted through the object and the reflected light reflected on the object are captured by the imaging unit, respectively, and the inspection of the object is performed based on the detection data output from the imaging unit. Prior art literature Patent literature Patent document 1 Japanese patent laid-open No. 2021-189071 Disclosure of Invention Technical problem to be solved by the invention The types of foreign substances in the object are various, but as the foreign substances, for example, a transparent body or the like whose shape is difficult to be specified, such as a plastic sheet, can be envisaged. In the case where the foreign matter is a transparent body, it is expected that it is difficult to detect the presence or absence of the foreign matter by observing only the transmitted light transmitted through the object and the reflected light reflected on the object. The present disclosure has been made to solve the above-described problems, and an object thereof is to provide an inspection apparatus capable of detecting the presence or absence of a foreign matter as a transparent body with high accuracy. Technical means for solving the problems The gist of the present disclosure is as shown in the following [1] to [9 ]. [1] An inspection apparatus for detecting a foreign object as a transparent body in an object includes an irradiation unit for irradiating the object with inspection light having a plurality of wavelengths, a spectroscopic detection unit for detecting light from an irradiation position of the inspection light from the object, and outputting a spectroscopic spectrum indicating the brightness of each wavelength at the irradiation position, and a determination unit for determining the presence or absence of the foreign object at the irradiation position based on information on the periodicity of the spectroscopic spectrum. In this inspection apparatus, for a spectrum of light representing the brightness of each wavelength at the irradiation position of the inspection light, the presence or absence of foreign matter at the irradiation position of the object is determined based on information on the periodicity thereof. In the case where the foreign matter is a transparent body, there are cases where the inspection light enters the foreign matter, specular reflection light that is specularly reflected on the surface of the foreign matter, specular reflection light that is specularly reflected on the back surface through the foreign matter, and multiple reflection light that is multiple-reflected in the foreign matter by the light that has passed through the foreign matter may be generated. Since these reflected lights interfere constructively or destructively depending on the phase difference between them determined by the wavelength and the optical path, the detected reflected lights are split into light beams, and a spectral spectrum having a peak-to-valley periodicity on the wavelength axis can be obtained. Thus, by using the inspection light including a plurality of wavelengths and splitting the reflected light, information on the periodicity of the split spectrum is obtained, and the presence or absence of a foreign substance as a transparent body can be detected with high accuracy. [2] The inspection apparatus according to [1], wherein the determination unit performs fourier transform on the spectrum, and determines whether the foreign matter is present at the irradiation position based on comparison between a peak value of intensity after fourier transform and a predetermined threshold value. By performing fourier transform of the spectrum, it is possible to easily grasp whether or not a periodic interference component is present in the spectrum based on whether or not a peak appears in the intensity after fourier transform. Thus, the presence or absence of foreign matter as a transparent body can be detected with higher accuracy. [3] The inspection apparatus according to [2], wherein the determination unit integrates the luminance of the spectrum in a predetermined wavelength band, and performs fourier transform of the spectrum when the integrated value exceeds a predetermined threshold. When a foreign object is present as a transparent body, specular reflection light from the foreign object can be detected, and therefore the brightness of the detected light tends to be higher than that of a region without the foreign object. Accordingly, by performing fourier transform of the spectrum only when the integrated value of the luminance of the spectrum i