JP2021071302A - Object inspection device and object inspection method - Google Patents

Abstract

To provide an object inspection device and an object inspection method which can inspect an inspection object on a thing having a rugged shape, with high accuracy.SOLUTION: The object inspection device has: an emission system which emits light to an object: and an imaging system including at least a spectral camera which acquires a monochrome image and a spectrum image on the basis of reflected light reflected from the object. When the spectrum image is acquired, the emission system and the imaging system are arranged to have a relationship of mirror reflection with respect to a normal of the object.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to an object inspection device and an object inspection method for inspecting an object based on spectral information.

By utilizing the spectral information of a large number of bands (for example, several tens of bands or more), each of which is a narrow band, it is possible to grasp the detailed physical properties of a substance (for example, liquid or thin film), which was impossible with conventional RGB images. can do. A camera that acquires this multi-wavelength information is called a "hyperspectral camera". Hyperspectral cameras are used in all fields such as food inspection, biopsy, drug development, and mineral component analysis.

Conventional hyperspectral cameras capable of measuring multi-wavelength images or reflectance can be roughly classified into the following five methods.
(A) Line sensor method (b) Electronic filter method (c) Fourier transform method (d) Interference filter method (e) Compressed sensing method

(A) The line sensor method will be described. In the line sensor method, one-dimensional information of an object is acquired by using a member having a line-shaped slit. The light that has passed through the slit is separated according to the wavelength by a spectroscopic element such as a diffraction grating or a prism. The separated light for each wavelength is detected by an image sensor (image sensor) having a plurality of pixels arranged in two dimensions. In the line sensor method, only one-dimensional information of the object to be measured can be obtained at one time, so two-dimensional spectral information can be obtained by scanning the entire camera or the object to be measured perpendicularly to the slit direction. The line sensor method has an advantage that a high-resolution multi-wavelength image can be obtained. A line sensor type hyperspectral camera is disclosed in, for example, Patent Document 1.

(B) The electronic filter method will be described. The electronic filter method includes a method using a liquid crystal tunable filter (LCTF) and a method using an acoustic optical element (Acousto-Optic Tunable Filter: AOTF). A liquid crystal tunable filter is an element in which a linear polarizer, a birefringence filter, and a liquid crystal cell are arranged in multiple stages. The liquid crystal tunable filter can eliminate light of an unnecessary wavelength only by voltage control and can extract only light of an arbitrary specific wavelength. The acoustic optical element is composed of an acoustic optical crystal to which a piezoelectric element is adhered. When an electric signal is applied to an acoustic-optical crystal, ultrasonic waves are generated and a sparse and dense standing wave is formed in the crystal. Due to the diffraction effect resulting from this, only light of an arbitrary specific wavelength can be extracted. The electronic filter method has an advantage that high-resolution moving image data can be acquired although the wavelength is limited.

(C) The Fourier transform method will be described. The Fourier transform method is a method using the principle of a two-luminous flux interferometer. The luminous flux from the measurement target is split by a beam splitter, each luminous flux is reflected by a fixed mirror and a moving mirror, recombined, and then observed by a detector. By changing the position of the moving mirror with time, it is possible to acquire data showing the change in the intensity of interference depending on the wavelength of light. Spectral information can be obtained by Fourier transforming the obtained data. The advantage of the Fourier transform method is that multi-wavelength information can be acquired at the same time. A Fourier transform type hyperspectral camera is disclosed in, for example, Patent Document 2.

(D) The interference filter method will be described. The interference filter method is a method using the principle of the Fabry-Perot interferometer. A configuration is used in which an optical element having two surfaces having high reflectance separated by a predetermined interval is arranged on the sensor. The distance between the two surfaces of the optical element varies from region to region and is determined to match the interference conditions of light of a desired wavelength. The interference filter method has an advantage that multi-wavelength information can be acquired simultaneously and as a moving image.

(E) The compressed sensing method will be described. In the compressed sensing method, a plurality of images separated for each wavelength band of light from the measurement object are estimated from the prism-spectroscopic image and the non-spectral image. The compressed sensing method has an advantage that hyperspectral data having a large amount of data can be compressed and stored. A compressed sensing type hyperspectral camera is disclosed in, for example, Patent Document 3.

The five methods of the hyperspectral camera have been described above.

The hyperspectral camera described above is used, for example, for inspecting an object. For example, in Patent Document 4, for the purpose of detecting abnormalities (states having different physical properties) of liquids filled in a container, the container is irradiated with measurement light from the outside of the container, and the reflection spectrum and absorption spectrum are measured. The method is disclosed.

In the method of Patent Document 4, first, in the first step, from all the pixels included in the spectral image obtained by imaging, the object imaging pixel containing information on the inspection object (for example, the liquid in the container). Is extracted. Next, in the second step, the average of the spectral intensities for each wavelength in the object imaging pixel is obtained, and the average reflection spectrum is calculated. Then, the abnormality is determined using the calculated average reflection spectrum.

Japanese Unexamined Patent Publication No. 2011-088955 Japanese Unexamined Patent Publication No. 2008-309706 Japanese Unexamined Patent Publication No. 2016-090576 Japanese Unexamined Patent Publication No. 2012-173174

However, conventionally, when an object to be inspected (for example, a liquid or a thin film) exists on an object having an uneven shape, a blind spot is generated due to the uneven shape when irradiating illumination light or imaging with a hyperspectral camera. There is. Therefore, it has been difficult to inspect the inspection object with high accuracy.

An object of one aspect of the present disclosure is to provide an object inspection apparatus and an object inspection method capable of inspecting an inspection object on an uneven object with high accuracy.

The object inspection apparatus according to one aspect of the present disclosure includes at least an imaging system that irradiates an object with light and a spectrum camera that acquires a monochrome image and a spectrum image based on the reflected light reflected from the object. When the system and the spectrum image are acquired, the illumination system and the imaging system are arranged for normal reflection with respect to the normal line of the object.

The object inspection apparatus according to one aspect of the present disclosure includes at least an imaging system that irradiates an object with light and a spectrum camera that acquires a monochrome image and a spectrum image based on the reflected light reflected from the object. It has a system, a half mirror that aligns an optical axis of light emitted from the irradiation system and irradiated on the object, and an optical axis of reflected light from the object incident on the imaging system.

The object inspection method according to one aspect of the present disclosure uses a lighting step of irradiating an object with light and a spectrum camera to acquire a monochrome image and a spectrum image based on the reflected light reflected from the object. It has an imaging step, and in the imaging step, when the spectrum image is acquired, the illumination system and the imaging system are arranged with normal reflection with reference to the normal line of the object.

The object inspection method according to one aspect of the present disclosure uses a lighting step of irradiating an object with light and a spectrum camera to acquire a monochrome image and a spectrum image based on the reflected light reflected from the object. The imaging step includes an optical axis of light emitted from the irradiation system and applied to the object by using a half mirror, and reflection from the object incident on the imaging system. Align with the optical axis of light.

According to the present disclosure, it is possible to inspect an inspection object on an uneven object with high accuracy.

Schematic diagram showing a configuration example of the object inspection device according to the first embodiment of the present disclosure. A flowchart showing the flow of the object inspection method according to the first embodiment of the present disclosure. Schematic diagram showing a configuration example of the spectrum camera according to the first embodiment of the present disclosure. Schematic diagram showing a configuration example of the phase shifter according to the first embodiment of the present disclosure. Schematic diagram showing an example of the positional relationship between the movable mirror portion and the fixed mirror portion according to the first embodiment of the present disclosure. Schematic diagram showing an example of the positional relationship between the movable mirror portion and the fixed mirror portion according to the first embodiment of the present disclosure. Schematic diagram showing an example of the positional relationship between the movable mirror portion and the fixed mirror portion according to the first embodiment of the present disclosure. The figure which shows an example of the infrared monochrome image which concerns on Embodiment 1 of this disclosure. The figure which shows an example of the spectrum image which concerns on Embodiment 1 of this disclosure. The figure which shows an example of the spectrum image which concerns on Embodiment 1 of this disclosure. Schematic diagram showing a configuration example of the object inspection device according to the second embodiment of the present disclosure.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. The components common to each figure are designated by the same reference numerals, and the description thereof will be omitted as appropriate.

(Embodiment 1)
The first embodiment of the present disclosure will be described.

<Structure of object inspection device 10>
First, the configuration of the object inspection device 10 of the present embodiment will be described with reference to FIG. FIG. 1 is a schematic view showing a configuration example of the object inspection device 10 of the present embodiment.

The object inspection device 10 is a device that inspects the object 100 (object 102). The term "inspection" as used herein may include meanings such as "judgment", "discrimination", or "specification".

The object inspection device 10 includes a sample drive system 20, a lighting system 30, an imaging system 40, and an image processing device (not shown). The sample drive system 20 and the image processing device do not have to be components of the object inspection device 10.

[Object 100]
The object 100 includes a concave-convex shape object 101 and an object 102. The object 102 is arranged on the uneven shape object 101.

The uneven shape object 101 is a substance having a specular reflectance of 5% or more with respect to the amount of incident light (for example, a metal surface, a smooth resin surface, etc.).

The object 102 is an object having a total light transmittance of 50% or more and a haze value of 50% or less. For example, the object 102 includes a transparent thin film such as acrylic or vinyl chloride, an overcoating agent or adhesive on liquid crystal or glass, a thin film for a touch panel, a metal film, a liquid of a transparent organic solvent, and the like.

The above-mentioned reflectance, total light transmittance, and haze value are assumed to be in the visible light region.

[Sample drive system 20]
The sample drive system 20 includes an X stage 201 driven in the left-right direction in the figure, a Y stage 202 driven in the front-rear direction in the figure, a Z stage 203 driven in the vertical direction in the figure, and a vertical direction in the figure. It has a θ stage 204 that rotates about its axis. As a result, the object 100 can be moved so that a blind spot does not occur when the object 102 on the uneven shape object 101 is imaged.

[Irradiation system 30]
The illumination system 30 has a light source (thermal light source) 301 that emits infrared parallel light. The light source 301 may be, for example, a flat panel surface light source, or a light source including a point light source and a collimating optical system (lens system, mirror system).

Since the object 102 has a property of appearing transparent in the visible light region, it is desirable that the light source 301 is a light source (for example, a halogen light source, a xenon light source, etc.) that emits infrared parallel light having an emission wavelength of 2500 nm to 15000 nm. Alternatively, the light source 301 may be realized by, for example, an infrared LED (Light Emitting Diode), which has been developed in recent years.

Alternatively, the light source 301 may be realized by a far-infrared heater or the like. Since the object 102 has a property of appearing transparent in the visible light region, it is desirable that the light source 301 can obtain the maximum efficiency at the infrared wavelength (high transmittance and reflectance) when the light source 301 includes a collimating optical system. Specifically, it is desirable to coat the lens group and mirror group of the collimating optical system with gold.

Further, the illumination system 30 can change the irradiation angle of infrared parallel light by an illumination rotation axis (not shown) that rotates in the horizontal direction in the drawing about the vertical direction in the drawing.

The illumination system 30 irradiates the object 100 with infrared parallel light. The reflected light from the object 100 is acquired by the imaging system 40. The illumination angle of the illumination system 30 and the imaging angle of the imaging system 40 will be described later.

[Imaging system 40]
The image pickup system 40 includes an image pickup optical system 401 and a spectrum camera 402.

The spectrum camera 402 is the hyperspectral camera described above. The emission wavelength of the spectrum camera 402 is 2500 nm to 15000 nm.

The reflected light from the object 100 passes through the imaging optical system 401 and reaches the spectrum camera 402. The spectrum camera 402 obtains an infrared monochrome image Mn and a spectroscopic spectrum image In based on the reflected light. These images are used in an image processing apparatus. The configuration of the spectrum camera 402 and the details of each image will be described later.

[Number of wavelength regions (number of bands)]
When a plurality of types of objects 102 having different material compositions are to be inspected, the number of bands in the narrow band of the spectrum camera 402 is preferably 10 bands or more. On the other hand, when one type of object 102 is to be inspected, the number of bands in the narrow band of the spectrum camera 402 may be about 3 bands.

Further, for the same reason as described in the illumination system 30, it is desirable that the imaging optical system 401 can obtain the maximum efficiency (high transmittance) at the infrared wavelength. Further, it is desirable that the spectrum camera 402 also obtains the maximum efficiency (high light receiving sensitivity) at the near infrared wavelength.

Specifically, it is desirable to suppress the surface reflectance by coating the lens group of the imaging optical system 401 with gold. Further, as the sensor of the spectrum camera 402, for example, it is desirable to adopt a quantum type sensor such as InGaAs, CdS, CdSe, PbS or a thermistor, or a thermal type sensor such as a bolometer.

The configuration of the object inspection device 10 has been described above.

<Object inspection method>
Next, an object inspection method using the object inspection apparatus 10 will be described with reference to FIGS. 1 and 2. FIG. 2 is a flowchart showing the flow of the object inspection method.

At the time of imaging the monochrome image Mn, the imaging system 40 is at the position (A) shown in FIG. When in position (A), the imaging system 40 is parallel to the vertical direction of FIG. 1 and perpendicular to the object 100.

The infrared parallel light emitted from the light source 301 irradiates the object 100 with an optical axis at an angle θα with reference to the optical axis of the imaging system 40 at the position (A). The angle θα is preferably 45 degrees or less so that the reflected light from the object 100 increases.

The light diffusely reflected from the object 100 passes through the imaging optical system 401 and reaches the spectrum camera 402. Then, the spectrum camera 402 captures an infrared monochrome image Mn (S101). The details of this imaging method will be described later.

The captured infrared monochrome image Mn is stored in, for example, an image processing apparatus (not shown; the same applies hereinafter) (S102).

The image processing apparatus identifies the position of the object 102 by using the stored infrared monochrome image Mn (S103).

For example, an image processing device uses AI image processing technology typified by general image processing such as noise removal, smoothing, sharpening, edge detection, and binarization to determine the position of an object 102. It is desirable to identify.

Next, the mechanism for moving the imaging system 40 (not shown) moves the imaging system 40 to the position shown in FIG. 1 based on the position of the specified object 102 and the shape information of the concave-convex shape object 101 set in advance. Move to (B). That is, the imaging system 40 is arranged so as to satisfy the relationship of the following mathematical formula (1). As a result, the irradiation system 30 and the imaging system 40 are arranged to have specular reflection with respect to the normal of the object 100. Therefore, the infrared parallel light emitted from the irradiation system 30 is specularly reflected and incident on the imaging system 40. In the following, the position (B) is also referred to as a "specular reflection position".

Next, the axis of the sample drive system 20 (the vertical axis in FIG. 1) is driven so that the object 102 does not become a blind spot (S104).

Next, the spectrum camera 402 captures a spectrum image In for each wavelength band (S105). The details of this imaging method will be described later.

The captured spectral image In is stored in, for example, an image processing apparatus (S106).

Next, the image processing apparatus converts each pixel of the spectrum image In into a wavelength spectrum Sp (S107).

Next, the image processing apparatus normalizes the wavelength spectrum Sp and averages the difference in spectral intensity due to the light amount distribution of the illumination system 30 (S108).

Next, the image processing apparatus determines the physical characteristics of the object 102 by using a general statistical method for the spectrum (S109).

Examples of the statistical method used here include PLS-DA (Partial Least Squares Regression Discriminant Analysis), SFF (Spectral Feature Fitting), and SAM (Spectral Angle Mapper).

The object inspection method using the object inspection apparatus 10 has been described above.

<Structure of spectrum camera 402>
Next, the configuration of the spectrum camera 402 will be described with reference to FIGS. 3 and 4. FIG. 3 is a schematic view showing a configuration example of the spectrum camera 402. FIG. 4 is a schematic view showing a configuration example of the phase shifter 4010 shown in FIG.

In the following, a case where the spectrum camera 402 is a Fourier transform type hyperspectral camera (see Patent Document 2) in which acquisition and switching between the infrared monochrome image Mn and the spectrum image In can be easily performed will be described as an example. However, the spectrum camera 402 is not limited to this, and may be a hyperspectral camera of another method (for example, a line sensor method, an electronic filter method, an interference filter method, a compressed sensing method, etc.).

As shown in FIG. 3, the reflected light from the bright spot of the object 100 enters the imaging optical system 401 and is converted into parallel light. The luminous flux after passing through the imaging optical system 401 does not have to be a perfect parallel luminous flux. As will be described later, it suffices if the group of light rays generated from one bright spot can be expanded to the extent that it can be divided into two or more. However, when the luminous flux after passing through the imaging optical system 401 is not a parallel luminous flux, an error is likely to occur in the amount of phase difference generated according to the amount of phase shift described later. Therefore, in order to obtain higher spectral measurement accuracy, it is desirable that the luminous flux after passing through the imaging optical system 401 is a parallel luminous flux.

As shown in FIG. 3, the parallel light flux transmitted through the image pickup lens system 401 reaches the phase shifter 4010.

As shown in FIG. 4, the phase shifter 4010 has a rectangular plate-shaped fixed mirror portion 4011, a columnar movable mirror portion 4012 inserted into the circular hole portion 4011a in the center thereof, and a holding portion 4013 for holding the movable mirror portion 4012. , A drive stage 4014 for moving the holding portion 4013 is provided. The surfaces of the fixed mirror unit 4011 and the movable mirror unit 4012 are optically flat and are optical mirror surfaces capable of reflecting the wavelength band of light to be measured by the spectrum camera 402.

In the following description, among the parallel light beams that have reached the phase shifter 4010, the light beams that reach the reflection surface of the fixed mirror unit 4011 and are reflected are referred to as "fixed light beam groups" and reach the reflection surface of the movable mirror unit 4012. The light beam reflected by the light beam is also called a "movable light beam group".

The drive stage 4014 is composed of a piezoelectric element including, for example, a capacitance sensor. The drive stage 4014 moves the holding unit 4013 in the direction of arrow A based on the control signal received from the control unit 4020. As a result, the movable mirror unit 4012 moves in the direction of arrow A with an accuracy corresponding to the wavelength of light. Although it depends on the spectroscopic measurement capability, for example, in the visible light region, highly accurate position control of about 10 nm is required.

For example, the movable mirror unit 4012 moves in the order of FIGS. 5A, 5B, 5C or 5C, 5B, 5A. As shown in FIG. 5B, a state in which the reflecting surface of the movable mirror portion 4012 coincides with the reflecting surface of the fixed mirror portion 4011 is referred to as a “phase shift origin”.

Further, as shown in FIG. 3, the phase shifter 4010 is arranged so that the reflecting surfaces of the fixed mirror portion 4011 and the movable mirror portion 4012 are tilted by 45 degrees with respect to the optical axis of the parallel luminous flux from the imaging optical system 401. .. The drive stage 4014 moves the movable mirror unit 4012 while maintaining the inclination of the reflective surface of the movable mirror unit 4012 with respect to the optical axis at 45 degrees.

With such a configuration, the amount of movement of the movable mirror unit 4012 in the optical axis direction is 1 / √2 of the amount of movement of the drive stage 4014. Further, the optical path length difference that gives a relative phase change between the two luminous fluxes of the fixed light beam group and the movable light ray group is twice the amount of movement of the movable mirror portion 4012 in the optical axis direction.

By arranging the fixed mirror unit 4011 and the movable mirror unit 4012 at an angle with respect to the optical axis of the parallel luminous flux from the imaging optical system 401 in this way, a beam splitter for splitting the light beam becomes unnecessary, so that the object light It is possible to increase the utilization efficiency of. Further, by tilting the movable mirror unit 4012, the amount of movement of the movable mirror unit 4012 in the optical axis direction with respect to the amount of movement of the drive stage 4014 becomes smaller. Therefore, the influence of deterioration of the stage movement error on the spectral measurement accuracy can be reduced.

As shown in FIG. 3, the fixed ray group and the movable ray group that have reached the phase shifter 4010 and are reflected by the reflecting surfaces of the fixed mirror portion 4011 and the movable mirror portion 4012 are converged and detected by the imaging lens 4022, respectively, as shown in FIG. Enter the image plane of the sensor 4024.

The detection unit 4024 is composed of, for example, a quantum sensor or thermistor such as InGaAs, CdS, CdSe, or PbS, or a thermal sensor such as a bolometer.

The reflective surface of the fixed mirror unit 4011 and the reflective surface of the movable mirror unit 4012 are configured to be parallel to each other on the image plane of the detection unit 4024 with an accuracy such that the focusing positions of the two light rays are not displaced.

The configuration of the spectrum camera 402 has been described above.

<Method of imaging infrared monochrome image Mn and spectral image In>
Next, imaging methods (which may be called acquisition methods) for each of the infrared monochrome image Mn and the spectral image In according to the present embodiment will be described.

First, an imaging method of the spectrum image In will be described.

Here, a group of light rays whose initial phases of the reflected light are not necessarily aligned are focused on one point as waves having the same phase on the imaging surface of the detection unit 4024 via the imaging optical system 401 and the imaging lens 4022. The description will be based on an optical model that forms a bright spot image (interference image).

As described above, the group of light rays emitted from one bright spot of the object 100 reaches the surfaces of the fixed mirror portion 4011 and the movable mirror portion 4012 of the phase shifter 4010 via the imaging optical system 401.

At this time, the light group reaches the surface of the fixed mirror portion 4011 and the surface of each of the movable mirror portions 4012 in two parts. The area of the surface of the movable mirror unit 4012 is set so that the amount of light of the group of light rays reaching the surface of the fixed mirror unit 4011 and the amount of light of the group of light rays reaching the surface of the movable mirror unit 4012 are substantially equal to each other. There is.

However, the present invention is not limited to this, and for example, a dimming filter is installed in at least one of the optical path from the bright spot of the object 100 to the fixed mirror portion 4011 and the optical path from the bright spot of the object 100 to the movable mirror portion 4012. By doing so, it is also possible to adjust the relative light amount difference to equalize the light amount.

The group of light rays reflected on the surface of the fixed mirror unit 4011 (that is, the group of fixed light rays) and the group of light rays reflected on the surface of the movable mirror unit 4012 (that is, the group of movable rays) are transferred to the imaging lens 4022, respectively. It is incident and forms an interference image on the image plane of the detection unit 4024.

At this time, the group of light rays emitted from the object 100 includes light of various wavelengths, and the initial phases of the light of each wavelength are not always aligned. Therefore, the movable mirror portion 4012 is moved in the order of FIGS. 5A, 5B, and 5C to change the optical path length difference between the fixed ray group and the movable ray group. As a result, it is possible to obtain a waveform of an imaging intensity change (interference light intensity change) called an interferogram.

By Fourier transforming this interferogram, it is possible to obtain the spectral characteristics which are the relative intensities of the light emitted from the bright spot of the object 100 for each wavelength. If the spectral characteristics can be obtained in all the pixels of the detection unit 4024, the two-dimensional spectroscopic measurement of the object 100 becomes possible, and the spectral image In can be obtained.

Next, a method of capturing an infrared monochrome image Mn will be described.

For example, the image at the phase shift origin (see FIG. 5B) may be used as it is as the infrared monochrome image Mn. Alternatively, for example, the drive stage 4014 may be stationary at the phase shift origin, and the image acquired at that time may be used as the infrared monochrome image Mn.

6A, 6B, and 6C show an example of the infrared monochrome image Mn and the spectral image In. 6A to 6C show images of the same coin (an example of the uneven shape object 101).

FIG. 6A shows an infrared monochrome image Mn. FIG. 6B shows the spectral image In captured in the specular arrangement. FIG. 6C shows the spectral image In captured when the arrangement is not specular (for example, the same position as the imaging position of the infrared monochrome image Mn). As is clear from the comparison between FIGS. 6B and 6C, in order to obtain the spectral image In of the object 102 on the uneven shape object 101 having a high specular reflection component, it is necessary to arrange the specular reflection.

(Embodiment 2)
The second embodiment of the present disclosure will be described.

The configuration of the object inspection device 10 of the present embodiment will be described with reference to FIG. 7. FIG. 7 is a schematic view showing a configuration example of the object inspection device 10 of the present embodiment. In FIG. 7, the same components as those in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted as appropriate below.

The object inspection device 10 shown in FIG. 7 is different from the object inspection device 10 shown in FIG. 1 in that it includes a half mirror 60. In the object inspection device 10 shown in FIG. 7, coaxial epi-illumination is realized by using the half mirror 60. The coaxial epi-illumination is an illumination method in which the optical axis of the light emitted from the irradiation system 30 irradiating the object 100 and the optical axis of the reflected light from the object 100 incident on the imaging system 40 are aligned with each other.

In FIG. 7, the infrared parallel light emitted from the illumination system 30 hits the half mirror 60, is bent 90 degrees with respect to the incident direction of the infrared parallel light, and reaches the object 100. Then, the light reflected by the object 100 passes straight through the half mirror 60 and is guided to the imaging system 40.

As a result, the illumination system 30 and the imaging system 40 are arranged for specular reflection from the initial stage. Therefore, the infrared monochrome image Mn and the spectral image In can be obtained without driving the axes of the illumination system 30 and the imaging system 40, respectively. Therefore, the inspection of the object 100 can be realized at a higher speed.

As the half mirror 60, for example, it is desirable to use a mirror that is close to 50% transmission and 50% reflection in the infrared region such as a dielectric multilayer film.

As described above, according to the object inspection device 10 of the first and second embodiments, monochrome based on the illumination system 30 that irradiates the object 100 with light and the reflected light reflected from the object 100. An imaging system 40 including at least a spectrum camera 402 for acquiring an image Mn and a spectrum image In, and when the spectrum image In is acquired, the illumination system 30 and the imaging system 40 refer to the normal line of the object 100. It becomes the arrangement of normal reflection. Therefore, it is possible to acquire a spectral image having a good SN ratio for an inspection object (for example, a liquid or a thin film) on an object having an uneven shape. As a result, it is possible to inspect the inspection target on the uneven object with high accuracy.

The present disclosure is not limited to the description of the above embodiment, and various modifications can be made without departing from the spirit of the present embodiment.

The object inspection apparatus and object inspection method of the present disclosure can be applied not only to inspections for abnormalities of liquids or thin films on uneven-shaped products, but also to inspections of surface plating of metals and the like, for example.

10 Object inspection device 20 Sample drive system 30 Lighting system 40 Imaging system 60 Half mirror 100 Object 101 Concavo-convex shape object 102 Object 201 X stage 202 Y stage 203 Z stage 204 θ stage 301 Light source 401 Imaging optical system 402 Spectrum camera 4010 Phase shifter 4011 Fixed mirror part 4012 Movable mirror part 4013 Holding part 4014 Drive stage 4020 Control part 4022 Imaging lens 4024 Detection part

Claims (6)

A lighting system that irradiates an object with light,
It has an imaging system including at least a spectral camera that acquires a monochrome image and a spectral image based on the reflected light reflected from the object.
When the spectral image is acquired, the illumination system and the imaging system are arranged for specular reflection with respect to the normal of the object.
Object inspection device. A lighting system that irradiates an object with light,
An imaging system including at least a spectrum camera that acquires a monochrome image and a spectrum image based on the reflected light reflected from the object.
It has a half mirror that aligns the optical axis of the light emitted from the irradiation system and irradiates the object with the optical axis of the reflected light from the object incident on the imaging system.
Object inspection device. The light receiving wavelength of the spectrum camera is 2500 nm to 15000 nm.
The object inspection apparatus according to claim 1 or 2. The lighting process that irradiates the object with light,
It has an imaging step of acquiring a monochrome image and a spectrum image based on the reflected light reflected from the object by using a spectrum camera.
In the imaging step, when the spectrum image is acquired, the illumination system and the imaging system are arranged with specular reflection with reference to the normal of the object.
Object inspection method. The lighting process that irradiates the object with light,
It has an imaging step of acquiring a monochrome image and a spectrum image based on the reflected light reflected from the object by using a spectrum camera.
In the imaging step, a half mirror is used to align the optical axis of the light emitted from the irradiation system and irradiating the object with the optical axis of the reflected light from the object incident on the imaging system. ,
Object inspection method. The light receiving wavelength of the spectrum camera is 2500 nm to 15000 nm.
The object inspection method according to claim 4 or 5.

Images