JP2022146623A - Inspection device - Google Patents

Abstract

To provide an inspection device suitable for a three-dimensional analysis capable of accurately detecting minute irregularities on a surface.SOLUTION: An inspection device 22 includes: a light source 10 for emitting light having different wavelengths; a first fiber optic plate 20; an optical member 40 allowing light to enter at a predetermined angle and emitting light at different angles depending on light wavelengths; a third fiber optic plate 24 having plural optical fibers in which only light having a predetermined wavelength from among emission light from a core of a second fiber optic plate 22 is incident on the core and advances within the core for reflection light reflected in a second direction D2 from an inspected surface S from the optical member 40; and an image sensor 50 on which emission light from the core of the third fiber optic plate 24 is incident. The maximum light reception angle of the third fiber optic plate 24 is smaller than the maximum light reception angle of the second fiber optic plate 22.SELECTED DRAWING: Figure 1

Description

The present invention relates to an inspection apparatus capable of detecting minute irregularities on a surface.

2. Description of the Related Art An inspection device capable of detecting minute irregularities on a surface is known. Among such inspection apparatuses, a holographic diffractive optical element is used to irradiate a surface to be inspected with light at different irradiation angles depending on the color of the light. A surface inspection apparatus for inspecting unevenness has been proposed (see, for example, Patent Document 1).

JP 2018-91770

However, in the surface inspection apparatus described in Patent Document 1, the light emitted from the white light source is incident on the incident surface of the holographic diffraction optical element from the normal direction, so that the light emitted from the holographic diffraction optical element , it may not be possible to sufficiently vary the emission angle for each color of light. For this reason, there is a possibility that minute irregularities on the surface cannot be detected accurately. In addition, since the light incident on the lens incorporated in the camera is detected, the photographed image becomes a striped gradation in which red, green, and blue continuously change. In other words, even a flat surface will reflect light of different colors at different locations. For this reason, it takes an enormous amount of analysis time to detect unevenness due to color changes, and is not suitable for three-dimensional analysis.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an inspection apparatus suitable for three-dimensional analysis capable of accurately detecting minute irregularities on a surface.

One aspect of the present invention is
a light source that emits light of different wavelengths;
a first fiber optic plate having a plurality of optical fibers in which the light emitted from the light source enters the core and travels through the core;
an optical member in which the light emitted from the core of the first fiber optic plate is incident at a predetermined angle with respect to the normal to the incident surface, and the light is emitted at different angles depending on the wavelength of the light;
A fiber optic plate having a plurality of optical fibers, in which light emitted from the optical member enters and travels inside in a first direction, i. a second fiber optic plate in which reflected light reflected in a second direction different from the first direction is incident on and travels through the core of the optical fiber;
a third fiber optic plate having a plurality of optical fibers, in which only light of a predetermined color out of the light emitted from the core of the second fiber optic plate enters the core and travels through the core;
an image sensor into which light emitted from the core of the third fiber optic plate is incident;
with
In the inspection device, the maximum light receiving angle of the third fiber optic plate is smaller than the maximum light receiving angle of the second fiber optic plate.

Another aspect of the invention is
a light source that emits light of different wavelengths;
a fourth fiber optic plate having a plurality of optical fibers in which the light emitted from the light source enters the core and travels through the core;
an optical member in which the light emitted from the core of the fourth fiber optic plate is incident at a predetermined angle with respect to the normal to the incident surface, and the light is emitted at different angles depending on the wavelength of the light;
a fifth fiber optic plate having a plurality of optical fibers in which the light emitted from the optical member is incident on the core and travels through the core, and the light emitted from the core is incident on the first surface to be inspected of the sample;
A sixth optical fiber having a plurality of optical fibers in which the light incident on the first surface to be inspected travels through the sample, and the light emitted from the second surface to be inspected of the sample enters a core and travels through the core. a fiber optic plate of
a seventh fiber optic plate having a plurality of optical fibers in which only light of a predetermined wavelength out of the light emitted from the core of the sixth fiber optic plate enters the core and travels through the core;
an image sensor into which light emitted from the core of the seventh fiber optic plate is incident;
with
In the inspection apparatus, the maximum light receiving angle of the seventh fiber optic plate is smaller than the maximum light receiving angle of the sixth fiber optic plate.

As described above, in the above aspect, it is possible to provide an inspection apparatus suitable for three-dimensional analysis that can accurately detect minute irregularities on a surface.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram which shows the outline|summary of the inspection apparatus which concerns on the 1st Embodiment of this invention. FIG. 4 is a schematic diagram for explaining an outline of a method for detecting unevenness of a surface to be inspected of a sample; It is a schematic diagram which shows the outline|summary of the test|inspection apparatus which concerns on the 2nd Embodiment of this invention. It is a schematic diagram which shows the outline|summary of the test|inspection apparatus which concerns on the 3rd Embodiment of this invention. It is a schematic diagram which shows the outline|summary of the test|inspection apparatus which concerns on the 4th Embodiment of this invention. FIG. 4 is a diagram schematically showing a case where the inspection device 2 is applied to a thin film modification process by irradiation with a pulse laser;

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. Corresponding members having the same function are denoted by the same reference numerals in each drawing. In consideration of the explanation of the main points or the ease of understanding, the embodiments may be shown separately for the sake of convenience, but partial replacement or combination of the configurations shown in different embodiments is possible. In the embodiments to be described later, descriptions of matters common to the above-described embodiments will be omitted, and only different points will be described. In particular, similar actions and effects due to similar configurations will not be mentioned sequentially for each embodiment.

(Inspection apparatus according to the first embodiment)
First, an inspection apparatus according to a first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a schematic diagram showing an overview of an inspection apparatus according to a first embodiment of the present invention.
The inspection device 2 according to the present embodiment is a compact device that can be carried to the site, and is an inspection device that can detect minute irregularities on a surface. FIG. 1 shows that the inspection device 2 is brought into contact with the surface S to be inspected of the sample 100 to detect minute unevenness existing on the surface. The inspection apparatus 2 according to the first embodiment, a second embodiment, and modified examples 1 and 2 thereof, which will be described later, uses reflected light from the surface S to be inspected to detect unevenness.

The inspection apparatus 2 includes a light source 10, a first fiber optic plate 20 connected to the light source 10, an optical member 40 connected to the first fiber optic plate 20, and an optical member 40 connected to the optical member 40 in order of light travel. a second fiber optic plate 22 connected, a third fiber optic plate 24 connected to the second fiber optic plate 22, and an image sensor 50 connected to the third fiber optic plate 24.

<Light source>
The light source 10 can employ a light source that emits light of any wavelength detectable by the image sensor 50 . Examples of light emitted from the light source 10 include ultraviolet light, visible light, near-infrared light, and infrared light.

In this embodiment, as the light source 10, a white light source including LED chips that emit light of the three primary colors of blue, green, and red is used. However, it is not limited to this, and a light source having LED chips of two colors out of blue, green, and red, or a combination of an LED chip that emits blue light and a phosphor that emits yellow light when blue light is incident. It is also possible to use a white light source, or a light source that combines an arbitrary number of LED chips and phosphors. A light source that emits not only visible light but also ultraviolet light, near-infrared light, middle-infrared light, far-infrared light, and the like can be used. In particular, as will be described later, when a photonic crystal element is used as the optical member 40, the angle at which light travels can be greatly changed within a narrow wavelength band. It is also possible to use only In order to improve the directivity of emitted light, a light source having a reflecting surface on the emission side of the LED chip is preferable. It is also possible to use a laser diode (LD), in which case emitted light with high directivity can be obtained. Furthermore, the light source is not limited to a surface light source, and a combination of a point light source and a lens or fiber optic plate can also be used.

<First Fiber Optic Plate>
A fiber optic plate is an optical member composed of a bundle of a plurality of optical fibers in which a core glass is covered with a clad glass, and an absorbing glass that fills the spaces between the optical fibers. Each optical fiber extends in the same direction. Light within the maximum acceptance angle of the optical fiber causes total reflection at the boundary between the core (glass) and the clad (glass), so the light is transmitted through the core with high transmission efficiency. Light exceeding the maximum acceptance angle does not enter the core, but is absorbed by the absorbing glass, so there is no risk of affecting other optical fibers.

The first fiber optic plate 20 has its entrance surface in contact with the exit surface of the light source 10 . The direction of the optical axis of the light source 10 substantially coincides with the direction of the optical axis of each optical fiber forming the first fiber optic plate 20 . The first fiber optic plate 20 according to this embodiment preferably has a large maximum acceptance angle so that light of all wavelengths emitted from the light source 10 enters the core. In this embodiment, the maximum light receiving angle is 180 degrees (full angle) (numerical aperture NA=1.0). The light that has entered the core advances through the core, thereby increasing the directivity of the light.
The exit surface of the first fiber optic plate 20 is in contact with the entrance surface of the optical member 40 . It should be noted that the optical axis of each optical fiber that constitutes the first fiber optic plate 20 has a predetermined angle with respect to the normal to the incident surface of the optical member 40 . That is, the emitted light from each optical fiber constituting the first fiber optic plate 20 is obliquely incident on the incident surface of the optical member 40 .

<Optical member>
In this embodiment, a photonic crystal element is used as the optical member 40 . When light is obliquely incident on the surface of a photonic crystal, the direction of the light traveling through the crystal changes very sensitively according to the wavelength and angle of incidence of the light, so the light resolving power is 100 to 1000 times that of glass. It can be made nearly twice as large. This is also called a super prism effect.
As described above, the light emitted from the first fiber optic plate 20 is obliquely incident on the optical member 40, which is a photonic crystal element. It can be emitted from the exit surface of the optical member 40 . In this embodiment, blue light (B), green light (G), and red light (R) are emitted from the emission surface of the optical member 40 at different angles. As for the angle, the difference in angle between the blue light and the red light is the largest, and the green light has an intermediate angle. Lights of the same color (wavelength) are emitted substantially in parallel. Here, blue light, green light, and red light are used for explanation, but in the photonic crystal device, a difference of 10 nm in light wavelength causes a change in the refraction angle of about 60 degrees, so light in a narrow wavelength band can be used. can also be used.

Although a photonic crystal element is used as the optical member 40 in this embodiment, it is not limited to this. For example, a holographic diffraction optical element can also be used as the optical member 40 . Even if the holographic diffraction optical element is used, blue light, green light, and red light can be emitted from the emission surface of the optical member 40 at different angles in the same manner as described above.

<Second Fiber Optic Plate>
The exit surface of the optical member 40 is in contact with the entrance surface 22A of the second fiber optic plate 22 . However, the entrance surface 22A of the second fiber optic plate 22 is not in contact with the entrance surface of the core of the second fiber optic plate 22 . The second fiber optic plate 22 further has an exit/entrance surface 22B in contact with the inspected surface S of the sample 100 and an exit surface 22C in contact with the entrance surface of the third fiber optic plate 24 . Thereby, it has a substantially triangular side shape. The exit/entrance surface 22</b>B in contact with the inspected surface S is in contact with the entrance surface of the core of the second fiber optic plate 22 . Also, the exit surface of the core of the second fiber optic plate 22 is in contact with the entrance surface of the core of the third fiber optic plate 24 .

Light emitted from the optical member 40 travels in the direction from the upper right to the lower left in the drawing, which is the direction intersecting the optical axis of the optical fiber inside the second fiber optic plate 22 . This direction is called the first direction (see arrow D1). The light emitted from the optical member 40 travels at different angles depending on the color of the light, but generally travels in the first direction indicated by the arrow D1.
By appropriately adjusting the amount of the absorbent added to the absorbing glass of the second fiber optic plate 22, the function of the fiber optic plate can be achieved and the light can pass through the second fiber optic plate 22 in the first direction D1. you can let it go.

The emitted light from the optical member 40 travels in the first direction D1 through the second fiber optic plate 22 and obliquely enters the surface S to be inspected from the incident/exiting surface 22B in contact with the surface S to be inspected of the sample 100. do. A flat surface such as a wall surface can be exemplified as the surface S to be inspected of the sample 100 . The light incident on the surface S to be inspected is obliquely reflected by the surface S to be inspected, and enters the core of the second fiber optic plate 22 from the incident/exiting surface 22B. The second fiber optic plate 22 according to the present embodiment is designed so that blue light (B), green light (G), and red light (R) emitted from the inspection surface S and traveling at different angles all enter the core. Additionally, it is preferable to have a large maximum acceptance angle. In this embodiment, the maximum light receiving angle of the second fiber optic plate 22 is 180 degrees (full angle). The light incident on the core of the third fiber optic plate 24 travels through the core, increasing the directivity of the light.

In order to prevent the light emitted from the optical member 40 from hitting the surface S to be inspected of the sample 100 and not directly entering the image sensor 50, the sizes of the entrance surface 22A, the exit/incidence surface 22B, and the exit surface 22C are The placement angle and core angle are properly adjusted. In addition, the outer surface of the second fiber optic plate 22, which is not in contact with other members, is sealed with a covered member 60 so that light does not leak to the outside.

<Third Fiber Optic Plate>
Light traveling through the core of the second fiber optic plate 22 reaches the entrance surface of the third fiber optic plate 24 that is in contact with the exit surface of the second fiber optic plate 22 .
Here, the third fiber optic plate 24 has a smaller maximum acceptance angle compared to the second fiber optic plate 22 . For example, the maximum acceptance angle of the third fiber optic plate 24 can be approximately 51 degrees (numerical aperture NA=0.43).

In the light reflected from the flat plane of the inspected surface S, the green light (G) in the center among the three colors of light traveling at different angles is within the maximum light receiving angle of the core, so it is incident on the core. However, since the blue light (B) and red light (R) on both sides of the core exceed the maximum light receiving angle of the core, they do not enter the core and are basically absorbed by the absorbing glass. Since the directivity of the light of each color is high while traveling through the core of the second fiber optic plate 22, only light of a predetermined color (here, green light (G)) is reliably selectively emitted to the second fiber optic plate 22. 3 fiber optic plate 24 .

If the surface S to be inspected has unevenness, the angle at which the reflected light travels differs, so the green light (G) does not enter the core, and the blue light (B) and the red light (R) do not enter the core. It may or may not be incident on the core of any color. Using this, the unevenness of the surface S to be inspected can be detected. This will be discussed in detail later.
The maximum light-receiving angle of the third fiber optic plate 24 is not limited to about 51 degrees. Preferably, a fiber optic plate with corners is used.

<Image sensor>
When only light of a predetermined color (for example, green light (G)) from the second fiber optic plate 22 enters the incident surface of the third fiber optic plate 24, it travels through the core and emerges from the core. is incident on the light receiving surface of the image sensor 50 in contact with the third fiber optic plate 24 . Image data for inspection can be obtained from light incident on the image sensor 50 from the third fiber optic plate 24 . As the image sensor 50, any light-receiving element such as CMOS and CCD can be used.

The following summarizes how light travels in the inspection apparatus 2 configured as described above.
Emitted light from the light source 10 is incident on the core of the first fiber optic plate 20 , travels through the core, and is obliquely incident on the incident surface of the optical member 40 . Blue light (B), green light (G), and red light (R) are emitted from the emission surface of the optical member 40 at different angles for each light color. Blue light (B), green light (G) and red light (R) travel through the second fiber optic plate 22 in the first direction, i. Incident on the surface S obliquely.

Reflected light (blue light (B), green light (G), and red light (R)) from the inspected surface S enters the core of the second fiber optic plate 22 and travels through the core. Then, in the third fiber optic plate 24, only light of a predetermined color (green light (G)) enters the core, and light of other colors is absorbed by the absorbing glass. As a result, only light of a predetermined color (green light (G)) is incident on the light receiving surface of image sensor 50 .

When the surface S to be inspected of the sample 100 is a flat plane without irregularities, the image obtained by the image sensor 50 is shown in green. On the other hand, if the first surface S to be inspected has unevenness, the angle at which the light travels changes. 50 may not be incident. Therefore, in an area having unevenness, the color of the image obtained by the image sensor 50 is different from that of an area without unevenness (for example, blue, red, and black), and unevenness can be detected based on the color.

(Method for detecting unevenness)
Next, with reference to FIG. 2, an outline of a method for detecting unevenness of the surface S to be inspected, which is a substantially flat surface of the sample 100, using the inspection apparatus 2 will be described. FIG. 2 is a schematic diagram for explaining an overview of a method for detecting unevenness on the inspected surface of a sample. (a) is a side view schematically showing how light travels, and (b) is a plan view showing an image obtained by an image sensor.

As described above, the emitted light from the optical member 40 is obliquely incident on the inspection surface S of the sample 100 at different angles for the blue light (B), green light (G), and red light (R). Blue light (B), green light (G), and red light (R) are reflected at different angles when incident on the flat plane Sa on the surface to be inspected S, but the second fiber optic plate 22 has a maximum acceptance angle of 180 degrees (full angle), so everything is incident on and into the core of the second fiber optic plate 22 . When the incident surface of the third fiber optic plate 24 is reached, the maximum acceptance angle of the third fiber optic plate 24 is about 51 degrees, so only the green light (G) in the center of the three colors of light traveling at different angles is incident on the core. Other colors of light do not enter the core and are absorbed by the absorbing glass. Therefore, since only the green light (G) is incident on the light receiving surface of the image sensor 50, a green image can be obtained on the inspected surface Sa without unevenness as shown in FIG. 2(b).

FIG. 2 shows irregularities having a triangular side sectional shape existing on the surface S to be inspected of the sample 100 . Here, when blue light (B), green light (G), and red light (R) are incident on the obliquely raised surface Sb, the red light (R) is reflected from the surface to be inspected Sa without unevenness. A case is shown in which light is reflected in a direction substantially parallel to the direction in which light travels. For this reason, when the blue light (B), green light (G) and red light (R) reflected by the surface Sa to be inspected reach the incident surface of the third fiber optic plate 24, three colors traveling at different angles are emitted. Of the lights, the red light (R) is within the maximum light receiving angle of the core and therefore enters the core, but the other blue light (B) and green light (G) do not enter the core and are absorbed by the absorbing glass. Therefore, since only red light is incident on the light receiving surface of the image sensor 50, a red image is obtained on the obliquely raised inspection surface Sb as shown in FIG. 2(b).

In FIG. 2, when blue light (B), green light (G), and red light (R) are incident on the obliquely raised surface Sc, the blue light (B) is reflected from the inspection surface Sa without unevenness. 4 shows a case where the reflected green light is reflected in a direction substantially parallel to the traveling direction of the emitted green light. For this reason, when the blue light (B), green light (G) and red light (R) reflected by the surface to be inspected Sc reach the incident surface of the third fiber optic plate 24, three colors traveling at different angles are emitted. Of the light, blue light (B) is within the maximum light receiving angle of the core, so it enters the core, but other green-blue (G) light and red light (R) do not enter the core and are absorbed by the absorbing glass. . Therefore, since only blue light (B) is incident on the light receiving surface of the image sensor 50, a blue image can be obtained on the obliquely protruded inspection surface Sc as shown in FIG. 2(b).

As described above, as shown in FIG. 2(b), it is possible to easily detect unevenness existing on the planar surface S to be inspected from the change in color. In the example shown in FIG. 2, for the sake of simplification, the projections formed of obliquely inclined planes are illustrated as the projections and recesses, but other arbitrary projections including projections having curved surfaces are also possible. , there may be recesses of any shape with recessed planes. When blue light (B), green light (G), and red light (R) are incident on such protrusions and recesses, the reflected light of any color will enter the core of the second fiber optic plate 22. There may be a case where the light does not enter. In that case, it appears black on the image obtained by the image sensor 50 . Even in such a case, it is possible to easily detect unevenness existing on the flat surface S to be inspected.

In the above description, the case where three primary colors of light having large wavelength differences are used to detect unevenness is described, but the present invention is not limited to this. Concavities and convexities can also be detected using light within a narrower wavelength range. For example, if the difference in wavelength of light is 10 nm, the angle at which the optical member 40, which is a photonic crystal element, can be changed by about 60 degrees. The maximum acceptance angle of the second fiber optic plate 22 is 180 degrees, while the maximum acceptance angle of the third fiber optic plate 24 is about 51 degrees, so the half angle changes from 90 degrees to about 25.5 degrees. Therefore, even if light in a narrow wavelength band with a wavelength difference of 10 nm is used, the third fiber optic plate 24 can select only light with a predetermined wavelength. Thus, by selectively sending light to the image sensor 50 with the third fiber optic plate 24, unevenness can be detected even with light in a narrow wavelength band. Since light within a wide wavelength range and light within a narrow wavelength range can be applied, the optimum wavelength range can be selected according to the light absorbing properties of the surface to be inspected.

(Inspection device according to the second embodiment)
Next, an inspection apparatus according to a second embodiment of the present invention will be described with reference to FIG. FIG. 3 is a schematic diagram showing an outline of an inspection apparatus according to a second embodiment of the present invention. This embodiment differs from the above-described first embodiment in that an additional light source 12 is provided behind the image sensor 50 . Other configurations are basically the same as those of the first embodiment.
The image sensor 50 of this embodiment is made of a translucent member. The rear surface of the image sensor 50 opposite to the light receiving surface is attached so that the output surface of the additional light source 12 is in contact therewith. As the further light source 12, a white light source using an LED can be exemplified.

Light emitted from the additional light source 12 is incident on and travels into the core of the third fiber optic plate 24 . Although the maximum acceptance angle of the third fiber optic plate 24 is not large, the light emitted from the additional light source 12 does not pass through the optical member 40, so that all wavelengths of light are reflected by the third fiber optic plate 24. incident on the core. Then, the light enters the core of the second fiber optic plate 22 , travels through the core, and obliquely enters the inspection surface S of the sample 100 .

The incident light is obliquely reflected by the surface S to be inspected, but since the maximum light receiving angle of the second fiber optic plate 22 is 180 degrees (full angle), almost all the reflected light passes through the core of the second fiber optic plate 22 , and travels in the core 180 degrees opposite to the time of incidence. Then, it enters the core of the third fiber optic plate 24 and advances into the core. Although the maximum acceptance angle of the third fiber optic plate 24 is not large, all wavelengths of light are incident on the core of the third fiber optic plate 24 because they do not pass through the optical member 40 . The white light incident on the core of the third fiber optic plate 24 travels through the core and strikes the light receiving surface of the image sensor 50 .

Thereby, a planar color image of the inspection surface S of the sample 100 obtained by irradiating the white light can be obtained. As described above, in this embodiment, it is possible to obtain an image showing unevenness existing on the surface S to be inspected by a change in color and a planar color image of the surface S to be inspected in one shot. When blue light (B), green light (G) and red light (R) are incident on the image sensor 50 by area through the second fiber optic plate 22, as in the example shown in FIG. , a normal map of the surface S to be inspected can be obtained by known image software.

As an application example using the inspection device 2 according to the above-described embodiment, the inspection device 2 can be relatively easily brought to the site of visual inspection of infrastructure such as tunnels, which can be exemplified by inspection of clutches on tunnel planes and the like. can. In addition to the detection of the unevenness of the wall surface by the light source 10, a planar color map can be acquired by the further light source 12. Therefore, it is possible to quickly determine whether the unevenness of the wall surface is due to scratches, cracks, or attachments. be able to distinguish.

Further, for example, by detecting unevenness using the light source 10 that emits near-infrared rays, it can be applied to high-definition fingerprint authentication. Also in this case, the normal map by the additional light source 12 can be effectively utilized.

Furthermore, the inspection apparatus 2 according to the above embodiment can also be applied to a thin film modification process as described in Japanese Patent No. 4208941 registered by the applicant of the present application. This will be described with reference to FIG. FIG. 6 is a diagram schematically showing the case where the inspection device 2 is applied to the thin film modification process by irradiation with a pulse laser.
As shown in FIG. 6, the thin film 100 of liquid crystal polymer can be modified by irradiating it with pulsed laser light from a laser diode (LD) 200 . When irradiated with a pulsed laser, a crosslinked structure is randomly formed between polymers, increasing mechanical strength and electromagnetic (light) sealing performance.

At this time, as shown in FIG. 6, the inspection device 2 can be installed on the surface of the thin film 200 opposite to the laser irradiation surface to detect structural changes on the surface of the thin film 100 . By using an appropriate wavelength band, it is possible to obtain an image of a three-dimensional structure with the inspection device 2 and capture changes in the optical properties of the thin film 100 caused by irradiation of the pulse laser in real time.

(general inspection equipment that reflects light on the surface to be inspected)
Summarizing the above first and second embodiments, the inspection apparatus 2 in which light is reflected by the surface S to be inspected is
A light source 10 that emits light of different wavelengths, a first fiber optic plate 20 having a plurality of optical fibers in which the light emitted from the light source 10 enters the core and travels through the core, and the first fiber optic plate 20. A fiber optic plate having an optical member 40 in which the light emitted from the core is incident at a predetermined angle with respect to the normal to the incident surface and the light is emitted at different angles depending on the wavelength of the light, and a plurality of optical fibers, The emitted light from the optical member 40 is incident, travels inside in a direction intersecting the optical axis of the optical fiber, which is the first direction D1, and travels from the surface S to be inspected in a second direction different from the first direction D1. The second fiber optic plate 22 in which the reflected light reflected by D2 enters the core of the optical fiber and travels through the core, and the light emitted from the core of the second fiber optic plate 22 has a predetermined wavelength. A third fiber optic plate 24 having a plurality of optical fibers in which only light enters the core and travels through the core, and an image sensor 50 into which light emitted from the core of the third fiber optic plate 24 enters. , the maximum acceptance angle of the third fiber optic plate 24 (eg, 51 degrees) is smaller than the maximum acceptance angle of the second fiber optic plate 22 (eg, 180 degrees).

Since the inspection device 2 is a device in which the light source 10, the image sensor 50, and the optical members 20, 40, 22, 24 are combined, a compact and lightweight device can be realized. In addition, the third fiber optic plate 24, which has a small maximum light-receiving angle, allows the image sensor 50 to capture only light of a predetermined wavelength (for example, green light (G)). It is possible to detect minute irregularities existing on the surface S to be inspected from the change in the color (wavelength) of . Regardless of where it is on the surface, if the structure (angle) of the defect is the same, the reflected light of the same color (wavelength) can be captured. Therefore, since the change in color (wavelength) of the image obtained by the image sensor 50 is uniquely caused only by the structure of the surface, three-dimensional reconstruction becomes possible more easily. Therefore, it is possible to provide an inspection apparatus 2 suitable for three-dimensional analysis that can accurately detect minute irregularities on the surface.

In such a detection device 2, the exit surface of the light source 10 and the entrance surface of the first fiber optic plate 20 are in contact, and the exit surface of the first fiber optic plate 20 and the entrance surface of the optical member 40 are in contact. , the exit surface of the optical member 40 and the entrance surface 22A of the second fiber optic plate 22 are in contact, the exit/incidence surface 22B of the second fiber optic plate 22 is in contact with the inspected surface S, and the second fiber The exit surface 22C of the optic plate 22 and the entrance surface of the third fiber optic plate 24 are in contact, and the exit surface of the third fiber optic plate 24 and the light receiving surface of the image sensor 50 are in contact.

Thereby, a compact and robust inspection device 2 is obtained. Furthermore, since outside air does not enter between the light emitting surface and the light receiving surface (light receiving surface), it is excellent in dustproof performance and can be used under various wavelengths and environments.

In a second embodiment, a further light source 12 is provided opposite to the entrance surface of the translucent image sensor 50 . The direction of the optical axis of the further light source 12 substantially coincides with the direction of the optical axis of the core of the third fiber optic plate 24 , and the emitted light is emitted from the image sensor 50 and the core of the third fiber optic plate 24 to the third fiber optic plate 24 . The reflected light that travels through the core of the second fiber optic plate 22 and is incident on the surface S to be inspected and is reflected from the surface S to be inspected travels from the core of the second fiber optic plate 22 to the third fiber optic plate 24 . , and enter the image sensor 50 .

As a result, in addition to the image showing the fine unevenness existing on the surface S to be inspected by the light source 10 in color, a planar color image by the light source 12 can be obtained in one shot. Further, it is possible to determine the cause of the detected unevenness by using a planar image from the light source 12, so that an effective inspection can be realized with a single photographing.

Further, when the optical member 40 is a photonic crystal element, even a slight difference in the wavelength of the light can greatly change the angle at which the light travels. Unevenness can be detected.

(Inspection device according to the third embodiment)
Next, an inspection apparatus according to a third embodiment of the present invention will be described with reference to FIG. FIG. 4 is a schematic diagram showing an outline of an inspection apparatus according to a third embodiment of the present invention.
The inspection device 2 according to this embodiment is also a small device that can be carried to the site. The inspection apparatus 2 according to the present embodiment and a fourth embodiment described later uses light transmitted through the sample 100 to detect irregularities on the outer surface of the sample 100, objects existing inside the sample 100, and the like. .

Although this embodiment differs in that inspection is performed by transmitting light through the sample 100, the majority of constituent members are the same as those of the reflective first embodiment. Therefore, detailed descriptions of similar constituent members are omitted.
The inspection apparatus 2 includes a light source 10, a fourth fiber optic plate 30 connected to the light source 10, an optical member 40 connected to the fourth fiber optic plate 30, and an optical member 40 connected to the optical member 40 in order of light travel. a fifth fiber optic plate 32 in contact with the first inspected surface S1 of the sample 100, a sixth fiber optic plate 34 in contact with the second inspected surface S2 of the sample 100, and a sixth fiber optic plate a seventh fiber optic plate 36 connected to 34 and an image sensor 50 connected to the seventh fiber optic plate 36 .

The fifth fiber optic plate 32 and the sixth fiber optic plate 34 are fixed to each other by a connecting member (not shown) with a predetermined gap therebetween. A sample 100 is inserted into the space between the fifth fiber optic plate 32 and the sixth fiber optic plate 34 . It is preferable to have a mechanism to change the distance between the fifth fiber optic plate 32 and the sixth fiber optic plate 34 according to the thickness of the sample 100 .

The light source 10 is the same as in the above embodiment, and uses a white light source provided with LED chips that emit light of the three primary colors of blue, green, and red. The fourth fiber optic plate 30 is similar to the first fiber optic plate 20 described above and has a maximum acceptance angle of 180 degrees (full angle). The optical member 40 is a photonic crystal element similar to that described above.
A fifth fiber optic plate 32 and a sixth fiber optic plate 34 are optical members corresponding to the second fiber optic plate 22 described above. The sample 100 has a plate-like shape in which the first surface to be inspected S1 and the second surface to be inspected S2 are substantially parallel.

The fifth fiber optic plate 32 is in contact with the first inspected surface S1 of the sample 100 on the lower side of the drawing, and the sixth fiber optic plate 34 is in contact with the second inspected surface S2 of the sample 100 on the upper side of the drawing. ing. The maximum acceptance angle of the fifth fiber optic plate 32 and the sixth fiber optic plate 34 is 180 degrees (full angle). The directions of the optical axes of the optical fibers of the fifth fiber optic plate 32 and the sixth fiber optic plate 34 are substantially parallel to the normals of the first surface to be inspected S1 and the second surface to be inspected S2. , has a predetermined angle. However, it is not limited to this, and the optical axes of the optical fibers of the fifth fiber optic plate 32 and the sixth fiber optic plate 34 are parallel to the first surface to be inspected S1 and the second surface to be inspected S2. In some cases, the line direction substantially coincides.
The seventh fiber optic plate 36 is similar to the third fiber optic plate 24 above and has a maximum acceptance angle of about 51 degrees.

How light travels in the inspection apparatus 2 configured as described above will be described. Light emitted from the light source 10 is incident on the core of the fourth fiber optic plate 30 , travels through the core, and is obliquely incident on the incident surface of the optical member 40 . Blue light (B), green light (G), and red light (R) are emitted from the emission surface of the optical member 40 at different angles for each light color. Blue light (B), green light (G), and red light (R) enter the core of the fifth fiber optic plate 32, travel through the core, and obliquely reach the first inspection surface S1 of the sample 100. Incident. Then, it advances through the sample 100 and emerges from the second surface S2 of the sample 100 to be inspected.

The emitted light (blue light (B), green light (G), and red light (R)) from the inspected surface S2 enters the core of the sixth fiber optic plate 34 and travels through the core. In the seventh fiber optic plate 36, basically only light of a predetermined color (green light (G)) is incident on the core, and light of other colors is absorbed by the absorbing glass. Thereby, only the predetermined color (green light (G)) is incident on the light receiving surface of the image sensor 50 .

When the first inspected surface S1 and the second inspected surface S2 of the sample 100 are flat surfaces with no unevenness and there is no object inside the sample 100 that interferes with the progress of light, the image sensor 50 The resulting image is shown in green. On the other hand, when the first surface to be inspected S1 and the second surface to be inspected S2 are uneven, or when impurities or the like are present inside the sample 100, the angle at which the light travels changes, so blue or red color is used. Areas shown and areas shown in black are produced, from which irregularities and impurities can be detected.

(Inspection device according to the fourth embodiment)
Next, an inspection apparatus according to a fourth embodiment of the present invention will be described with reference to FIG. FIG. 5 is a schematic diagram showing an overview of an inspection apparatus according to a fourth embodiment of the present invention.
This embodiment differs from the above-described third embodiment in that an additional light source 12 is provided behind the image sensor 50 . Other configurations are basically the same as those of the third embodiment.

The image sensor 50 of the present embodiment is similar to that of the second embodiment described above and is made of a translucent member. The rear surface of the image sensor 50 opposite to the light receiving surface is attached so that the output surface from the light source 12 is in contact therewith. As the further light source 12, a white light source using an LED can be exemplified.
Further emitted light from the light source 12 is reflected by the first inspection surface S<b>1 of the sample 100 and enters the light receiving surface of the image sensor 50 . As a result, a planar color image of the surface to be inspected S1, which ranks first, is obtained. The path along which the light travels to obtain the planar color image of the first inspection surface S1 is the same as in the second embodiment, so further detailed description will be omitted.

(general inspection equipment in which light passes through the sample)
Summarizing the above third and fourth embodiments, the inspection apparatus 2 in which light passes through the sample 100 is
A light source 10 that emits light of different wavelengths, a fourth fiber optic plate 30 having a plurality of optical fibers in which the light emitted from the light source 10 enters a core and travels through the core, and a fourth fiber optic plate 30 An optical member 30 in which light emitted from the core is incident at a predetermined angle with respect to the normal line of the incident surface and the light is emitted at different angles depending on the wavelength of the light, and the light emitted from the optical member 30 is incident on the core. A fifth fiber optic plate 32 having a plurality of optical fibers that travels through the core and the light emitted from the core is incident on the first surface to be inspected S1 of the sample 100, and the light incident on the first surface to be inspected S1. travels through the sample 100, the light emitted from the second surface to be inspected S2 of the sample enters the core and travels through the core, a sixth fiber optic plate 34 having a plurality of optical fibers, and a sixth fiber A seventh fiber optic plate 36 having a plurality of optical fibers in which only light of a predetermined wavelength out of the light emitted from the core of the optic plate 34 enters the core and travels through the core, and the seventh fiber optic plate 36 and an image sensor 50 into which light emitted from the core of is incident, wherein the maximum acceptance angle of the seventh fiber optic plate 36 (for example, about 51 degrees) is equal to the maximum acceptance angle of the sixth fiber optic plate 34 (for example, 180 degrees).

Since the inspection device 2 is a device in which the light source 10, the image sensor 50, and the optical members 30, 40, 32, 34, and 36 are combined, a compact and lightweight device can be realized. In addition, the seventh fiber optic plate 36 having a small maximum light receiving angle allows the image sensor 50 to capture only light of a predetermined color (for example, green light (G)). A slight unevenness existing on the first and second surfaces S1 and S2 to be inspected and an object existing in the sample 100 can be detected from the change in color. In particular, since the change in color (wavelength) of the image obtained by the image sensor 50 is uniquely caused only by the surface or internal structure, three-dimensional reconstruction becomes possible more easily. Therefore, it is possible to provide an inspection apparatus 2 suitable for three-dimensional analysis that can accurately detect minute irregularities on the surface and objects in the sample.

In such a detection device 2, the exit surface of the light source 10 and the entrance surface of the fourth fiber optic plate 30 are in contact, and the exit surface of the fourth fiber optic plate 30 and the entrance surface of the optical member 40 are in contact. , the exit surface of the optical member 40 is in contact with the entrance surface of the fifth fiber optic plate 32, the exit surface of the fifth fiber optic plate 32 is in contact with the first inspected surface S1, and the second inspected surface S1 is in contact with the exit surface of the fifth fiber optic plate 32. The inspection surface S2 is in contact with the entrance surface of the sixth fiber optic plate 34, the exit surface of the sixth fiber optic plate 34 is in contact with the entrance surface of the seventh fiber optic plate 36, and the seventh fiber optic plate The output surface of the plate 36 and the light receiving surface of the image sensor 50 are in contact with each other.

Thereby, a compact and robust inspection device 2 is obtained. Furthermore, since outside air does not enter between the light emitting surface and the light receiving surface (light receiving surface), it is excellent in dustproof performance and can be used under various wavelengths and environments.

In a fourth embodiment, a further light source 12 is provided opposite the incident surface of the translucent image sensor 50 . The direction of the optical axis of the further light source 12 substantially coincides with the direction of the optical axis of the core of the seventh fiber optic plate 36 , and the emitted light is emitted from the image sensor 50 and the core of the seventh fiber optic plate 36 to the 7th fiber optic plate 36 . The reflected light that travels through the core of the fiber optic plate 34 of No. 6 and is incident on the second surface S2 to be inspected and reflected from the second surface S2 to be inspected travels from the core of the sixth fiber optic plate 34 to the second surface S2. 7 to enter the image sensor 50 through the core 36 of the fiber optic plate.

As a result, in one photographing operation, in addition to the image showing the minute irregularities present on the surface S to be inspected by the light source 10 and the objects present in the sample 100 in color, it is also possible to obtain a planar image by the light source 12 . . Furthermore, since it is possible to discriminate what caused the detected unevenness or the object by using the planar image by the light source 12, it is possible to realize an effective inspection with one-time photographing.

Although embodiments and embodiments of the present invention have been described, the disclosure may vary in details of construction, and changes in the combination and order of elements in the embodiments and embodiments, etc., will not affect the claimed invention. without departing from the scope and spirit of

2 inspection device 10 light source 12 further light source 20 first fiber optic plate 22 second fiber optic plate 24 third fiber optic plate 26 translucent member 30 fourth fiber optic plate 32 fifth fiber optic plate 34 sixth fiber optic plate 36 seventh fiber optic plate 40 optical member 50 image sensor 100 sample S surface to be inspected S1 first surface to be inspected S2 second surface to be inspected

Claims (7)

a light source that emits light of different wavelengths;
a first fiber optic plate having a plurality of optical fibers in which the light emitted from the light source enters the core and travels through the core;
an optical member in which the light emitted from the core of the first fiber optic plate is incident at a predetermined angle with respect to the normal to the incident surface, and the light is emitted at different angles depending on the wavelength of the light;
A fiber optic plate having a plurality of optical fibers, in which light emitted from the optical member enters and travels inside in a first direction, i. a second fiber optic plate in which reflected light reflected in a second direction different from the first direction is incident on and travels through the core of the optical fiber;
a third fiber optic plate having a plurality of optical fibers, in which only light of a predetermined color out of the light emitted from the core of the second fiber optic plate enters the core and travels through the core;
an image sensor into which light emitted from the core of the third fiber optic plate is incident;
with
The inspection apparatus, wherein the maximum light receiving angle of the third fiber optic plate is smaller than the maximum light receiving angle of the second fiber optic plate. The exit surface of the light source is in contact with the entrance surface of the first fiber optic plate, the exit surface of the first fiber optic plate is in contact with the entrance surface of the optical member, and the exit surface of the optical member is in contact. The entrance surface of the second fiber optic plate is in contact with the surface to be inspected, the exit surface of the second fiber optic plate is in contact with the surface to be inspected, and the exit surface of the second fiber optic plate is in contact with the third fiber optic plate. 2. The inspection apparatus according to claim 1, wherein the entrance surface of said fiber optic plate is in contact with said third fiber optic plate and said light receiving surface of said image sensor is in contact with said exit surface of said third fiber optic plate. A light source disposed on the opposite side of the incident surface of the image sensor having translucency, the direction of the optical axis of which substantially coincides with the direction of the optical axis of the core of the third fiber optic plate, and emitted light advances from the core of the image sensor and the third fiber optic plate to the core of the second fiber optic plate and enters the surface to be inspected, and the reflected light reflected from the surface to be inspected is the 3. Inspection apparatus according to claim 1 or 2, comprising a further light source that travels from within the core of the second fiber optic plate to within the core of the third fiber optic plate and impinges on the image sensor. a light source that emits light of different wavelengths;
a fourth fiber optic plate having a plurality of optical fibers in which the light emitted from the light source enters the core and travels through the core;
an optical member in which the light emitted from the core of the fourth fiber optic plate is incident at a predetermined angle with respect to the normal to the incident surface, and the light is emitted at different angles depending on the wavelength of the light;
a fifth fiber optic plate having a plurality of optical fibers in which the light emitted from the optical member is incident on the core and travels through the core, and the light emitted from the core is incident on the first surface to be inspected of the sample;
A sixth optical fiber having a plurality of optical fibers in which the light incident on the first surface to be inspected travels through the sample, and the light emitted from the second surface to be inspected of the sample enters a core and travels through the core. a fiber optic plate of
a seventh fiber optic plate having a plurality of optical fibers in which only light of a predetermined wavelength out of the light emitted from the core of the sixth fiber optic plate enters the core and travels through the core;
an image sensor into which light emitted from the core of the seventh fiber optic plate is incident;
with
The inspection apparatus, wherein the maximum light receiving angle of the seventh fiber optic plate is smaller than the maximum light receiving angle of the sixth fiber optic plate. The exit surface of the light source is in contact with the entrance surface of the fourth fiber optic plate, the exit surface of the fourth fiber optic plate is in contact with the entrance surface of the optical member, and the exit surface of the optical member is in contact. The entrance surface of the fifth fiber optic plate is in contact, the exit surface of the fifth fiber optic plate is in contact with the first surface to be inspected, and the second surface to be inspected and the sixth surface are in contact. The entrance surface of the fiber optic plate is in contact with the exit surface of the sixth fiber optic plate and the entrance surface of the seventh fiber optic plate is in contact with the exit surface of the seventh fiber optic plate and the image. 5. The inspection apparatus according to claim 4, wherein the light receiving surfaces of the sensors are in contact with each other. A light source disposed on the opposite side of the incident surface of the image sensor having translucency, the direction of the optical axis of which substantially coincides with the direction of the optical axis of the core of the seventh fiber optic plate, and emitted light travels from within the core of the image sensor and the seventh fiber optic plate to within the core of the sixth fiber optic plate, enters the second surface to be inspected, and is reflected from the second surface to be inspected. 6. A further light source from which reflected light travels from within the core of said sixth fiber optic plate to within the core of said seventh fiber optic plate and enters said image sensor. The inspection device described in . 7. The inspection apparatus according to claim 1, wherein said optical member is a photonic crystal element.

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