JP2021085658A - Foreign matter detection device and foreign matter detection method - Google Patents

Abstract

To measure depth of foreign matter at low cost.SOLUTION: A foreign matter detection device 100 includes: a mirror 110 provided on one side of a transparent plate 12; a light emitting unit (a second light emitting unit 140) provided on the other surface side of the transparent plate 12; an imaging unit 130 provided on the other surface side of the transparent plate 12; a detection unit 152 that detects depth of foreign matter C contained in the transparent plate 12 based on the distance between the foreign matter and the mirror image of the foreign matter projected on the mirror 110 in the image captured by the imaging unit 130.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to a foreign matter detecting device and a foreign matter detecting method.

A foreign matter detecting device for detecting a foreign matter on a transparent plate is widely used. As a technique for detecting a foreign matter, a foreign matter detecting device including a first inspection device, an adhering foreign matter removing device, and a second inspection device has been developed (for example, Patent Document 1).

In the technique of Patent Document 1, the transparent sheet is moved in the horizontal direction, and the first inspection device, the adhering foreign matter removing device, and the second inspection device are provided in order from the upstream side in the moving direction. The first inspection device and the second inspection device are cameras. The first inspection device detects foreign matter on the transparent body sheet. The adhering foreign matter removing device blows air onto the transparent body sheet to remove the foreign matter adhering to the surface of the transparent body sheet. When the second inspection device detects a foreign substance having the same size and shape as the foreign matter detected by the first inspection device, it is determined that the foreign matter is in the transparent body sheet. On the other hand, when the second inspection device does not detect a foreign substance having the same size and shape as the foreign matter detected by the first inspection device, it is determined that the foreign matter is on the surface of the transparent body sheet.

Japanese Unexamined Patent Publication No. 2007-238261

The technique of Patent Document 1 requires two cameras and a foreign matter removing device, and has a problem that the cost required for measuring the depth of foreign matter increases.

Therefore, in view of such problems, it is an object of the present disclosure to provide a foreign matter detecting device and a foreign matter detecting method capable of measuring the depth of foreign matter at low cost.

In order to solve the above problems, the foreign matter detecting device according to one aspect of the present disclosure includes a mirror provided on one surface side of the transmission plate, a light emitting portion provided on the other surface side of the transmission plate, and a transmission plate. Detection that detects the depth of foreign matter contained in the transmission plate based on the distance between the mirror image of the foreign matter projected on the mirror and the foreign matter in the image captured by the imaging unit provided on the other surface side and the image captured by the imaging unit. It has a part and.

Further, the mirror may come into contact with one surface of the transmission plate.

In order to solve the above problems, the foreign matter detecting device according to another aspect of the present disclosure includes a transmission plate and a mirror provided in contact with one surface side of the transmission plate on the other surface of the inspection object. Inspection based on the distance between the mirror image of the foreign matter projected on the mirror and the foreign matter in the image captured by the light emitting unit provided on the side, the imaging unit provided on the other surface side of the inspection object, and the imaging unit. It is provided with a detection unit that detects the depth of foreign matter contained in the object.

In order to solve the above problems, the foreign matter detection method according to one aspect of the present disclosure includes a step of installing a mirror on one surface side of the transmission plate, a step of irradiating light from the other surface side of the transmission plate, and the like. The depth of the foreign matter contained in the transparent plate is determined based on the distance between the foreign matter and the mirror image of the foreign matter projected on the mirror in the step of imaging from the other surface side of the transmission plate and the image captured in the imaging step. Includes a step of detecting.

According to the present disclosure, it is possible to measure the depth of foreign matter at low cost.

It is a figure explaining the foreign matter detection apparatus of embodiment. It is a flowchart which shows the flow of the foreign matter detection method of embodiment. It is a figure explaining the position (first position) of the image pickup part in the 1st image pickup process. It is a figure explaining the position (second position) of the imaging part in the 2nd imaging step. FIG. 5A is a diagram illustrating the position P1 of the inspection object. FIG. 5B is a diagram illustrating an image when there is a foreign substance at the position P1. FIG. 5C is a diagram for explaining the position P2 in the inspection object. FIG. 5D is a diagram illustrating an image when there is a foreign object at the position P2. FIG. 5E is a diagram for explaining the position P3 in the inspection object. FIG. 5F is a diagram for explaining an image when there is a foreign substance at the position P3. It is a figure explaining the foreign matter detection apparatus of the modification.

The embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in the embodiments are merely examples for facilitating understanding, and the present disclosure is not limited unless otherwise specified. In the present specification and the drawings, elements having substantially the same function and configuration are designated by the same reference numerals, so that duplicate description will be omitted. In addition, elements not directly related to the present disclosure are not shown.

[Foreign matter detection device 100]
FIG. 1 is a diagram illustrating a foreign matter detecting device 100 of the present embodiment. In FIG. 1, the dashed arrow indicates the signal flow. In FIG. 1, the alternate long and short dash line indicates light. Further, in the following figures including FIG. 1 of the present embodiment, the X-axis, the Y-axis, and the Z-axis that intersect vertically are defined as shown in the figure.

As shown in FIG. 1, the foreign matter detecting device 100 includes a foreign matter adhering to the inspection object 10 and a foreign matter contained in the inspection object 10 (hereinafter, both are collectively referred to as "foreign matter contained in the inspection object 10". ”) Is detected. In the present embodiment, the inspection object 10 is moved in the X-axis direction and the Y-axis direction in FIG. 1 by a moving mechanism (not shown).

The inspection object 10 includes a transmission plate 12 and a protective film 14. The transmission plate 12 is a flat plate capable of transmitting light. The transmissive plate 12 and the protective film 14 are made of a material having a light transmittance of 10% or more (for example, a transparent material) in the wavelength band from infrared rays to ultraviolet rays (for example, 10 nm or more and 1000 μm or less) including visible light (360 nm or more and 830 nm or less). , Or a translucent material). Further, the transmission plate 12 and the protective film 14 are made of a material having a higher light transmittance than the foreign matter C.

In FIG. 1, the length of the transmission plate 12 in the X-axis direction and the length in the Y-axis direction are equal to or larger than the thickness (length) in the Z-axis direction.

The protective film 14 is provided over the entire surface of one of the surfaces of the transmission plate 12. The protective film 14 is in close contact with the transparent plate 12.

As shown in FIG. 1, the foreign matter detecting device 100 includes a mirror 110, a first light emitting unit 120, an imaging unit 130, a second light emitting unit 140, and a central control unit 150.

The mirror 110 is provided on one surface (back surface) side of the transmission plate 12. In the present embodiment, the mirror 110 is provided on the surface of the transmission plate 12 opposite to the surface on which the protective film 14 is provided. Further, the mirror 110 comes into contact with one surface of the transmission plate 12.

In the present embodiment, the mirror 110 is a beam splitter that reflects a part of the incident light and transmits a part of the incident light. A beam splitter is, for example, a half mirror in which the intensity of reflected light and the intensity of transmitted light are substantially equal.

The first light emitting unit 120 is provided on one surface side of the transmission plate 12. The first light emitting unit 120 is provided farther than the mirror 110 with reference to the inspection object 10. The first light emitting unit 120 irradiates the mirror 110 (one surface of the inspection object 10) with light in a wavelength band from infrared rays to ultraviolet rays including visible light. The first light emitting unit 120 irradiates, for example, visible light. The first light emitting unit 120 is turned on and off by the central control unit 150, which will be described later.

The image pickup unit 130 is provided on the other surface (surface) side of the transmission plate 12. That is, the imaging unit 130 is provided on the protective film 14 side of the inspection object 10. The imaging unit 130 is moved to a first position (indicated by a solid line in FIG. 1) and a second position (indicated by a broken line in FIG. 1) by a displacement mechanism (not shown). In this embodiment, the first position and the second position are on substantially the same YZ plane.

The first position is a position where the optical axis K of the imaging unit 130 is orthogonal to the XY plane in FIG. That is, the first position is a position where the optical axis K of the imaging unit 130 is orthogonal to the surface of the inspection object 10 (the surface of the protective film 14). Further, the imaging unit 130 faces the first light emitting unit 120 at the first position. In the present embodiment, the optical axis K of the imaging unit 130 at the first position and the central axis M of the light emitted by the first light emitting unit 120 are arranged coaxially.

The second position is the light emitted by the second light emitting unit 140, which will be described later, at an angle formed by the optical axis K of the imaging unit 130 at the first position and the optical axis K of the imaging unit 130 at the second position. This is the position where the light reflected by the inspection object 10 (foreign matter C) and the mirror 110 is reflected (that is, the incident angle θ). That is, the image pickup unit 130 at the second position is an angle at which the light emitted by the second light emitting unit 140 and reflected by the foreign matter C and the light reflected by the mirror image D of the foreign matter projected on the mirror 110 are incident. It is provided so as to be. In the present embodiment, in the imaging unit 130, the optical axis K of the imaging unit 130 at the first position and the optical axis K of the imaging unit 130 at the second position are on the surface of the mirror 110 (transmission plate 12 in the mirror 110). It is moved so as to intersect at the contact surface).

The second light emitting unit 140 (light emitting unit) is provided on the other surface side of the transmission plate 12. That is, the second light emitting unit 140 is provided on the same side as the imaging unit 130 with reference to the inspection object 10. Further, the second light emitting unit 140 is provided on the side opposite to the image pickup unit 130 at the second position with reference to the image pickup unit 130 at the first position. In the present embodiment, the second light emitting unit 140 is provided on a YZ plane substantially the same as the imaging unit 130.

The second light emitting unit 140 irradiates the other surface (protective film 14) of the inspection object 10 with light in a wavelength band from infrared rays to ultraviolet rays including visible light. The second light emitting unit 140 irradiates, for example, visible light.

The second light emitting unit 140 irradiates the inspection object 10 with light so that the incident angle is θ (0 degree <θ <90 degree). The second light emitting unit 140 is turned on and off by the central control unit 150.

The central control unit 150 is composed of a semiconductor integrated circuit including a CPU (Central Processing Unit). The central control unit 150 reads out a program, parameters, and the like for operating the CPU itself from the ROM. The central control unit 150 manages and controls the entire foreign matter detection device 100 in cooperation with the RAM as a work area and other electronic circuits.

In the present embodiment, the central control unit 150 drives the moving mechanism, drives the displacement mechanism, and turns on / off the first light emitting unit 120 and the second light emitting unit 140.

Further, in the present embodiment, the central control unit 150 functions as a detection unit 152. The detection unit 152 acquires an image captured by the image pickup unit 130. Further, the detection unit 152 detects the depth of the foreign matter C contained in the inspection object 10 based on the acquired image.

[Foreign matter detection method]
Subsequently, a foreign matter detecting method using the foreign matter detecting device 100 will be described. FIG. 2 is a flowchart showing the flow of the foreign matter detecting method of the present embodiment. As shown in FIG. 2, the foreign matter detection method includes an installation step S110, an inspection end determination step S120, a moving step S130, a first imaging step S140, a foreign matter presence / absence determination step S150, a displacement step S160, a second imaging step S170, and a foreign matter depth. It includes a pass determination step S180, a fail determination step S190, and a pass determination step S200. Hereinafter, each step will be described.

[Installation process S110]
The installation step S110 is a step in which the central control unit 150 drives an installation mechanism (not shown) to install (contact) one surface side of the inspection object 10 on the mirror 110.

[Inspection end determination step S120]
The inspection end determination step S120 is a step in which the central control unit 150 determines whether or not the foreign matter inspection has been completed on the entire surface (XY plane in FIG. 1) of the inspection object 10. Specifically, the central control unit 150 determines whether or not the imaging of the entire surface of the inspection object 10 by the imaging unit 130 at the first position has been completed. As a result, when it is determined that the foreign matter inspection is completed (YES in S120), the central control unit 150 shifts the process to the pass determination step S200. On the other hand, when it is determined that the foreign matter inspection is not completed (NO in S120), the central control unit 150 shifts the process to the moving step S130.

[Movement step S130]
In the moving step S130, first, the central control unit 150 drives the displacement mechanism to move the imaging unit 130 to the first position. Then, the central control unit 150 drives the moving mechanism to move the inspection object 10 together with the mirror 110 by a predetermined distance in either one or both of the X direction and the Y direction in FIG. The predetermined distance is the distance from the imaging range of the imaging unit 130 when the first imaging step S140 was executed last time to the imaging range of the adjacent imaging unit 130. The imaging range is the range of the inspection object 10 that can be imaged by the imaging unit 130.

[First Imaging Step S140]
FIG. 3 is a diagram illustrating a position (first position) of the imaging unit 130 in the first imaging step S140. As shown in FIG. 3, the first imaging step S140 is a step in which the central control unit 150 drives the imaging unit 130 at the first position to image the inspection object 10. At this time, the central control unit 150 turns on the first light emitting unit 120. Further, the central control unit 150 turns off the second light emitting unit 140.

[Foreign matter presence / absence determination step S150]
The foreign matter presence / absence determination step S150 is a step in which the detection unit 152 analyzes the image obtained by the first imaging step S140 to detect the presence / absence of the foreign matter C in the imaging range. For example, the detection unit 152 binarizes the image and determines that there is a foreign matter C when a predetermined number or more of black pixels are continuous. Then, when the central control unit 150 determines that the foreign matter C is present (YES in S150), the central control unit 150 shifts the process to the displacement step S160. On the other hand, when the central control unit 150 determines that there is no foreign matter (NO in S150), the process returns to the inspection end determination step S120.

[Displacement step S160]
The displacement step S160 is a step in which the central control unit 150 drives the displacement mechanism to move the imaging unit 130 from the first position to the second position.

[Second imaging step S170]
FIG. 4 is a diagram illustrating a position (second position) of the imaging unit 130 in the second imaging step S170. As shown in FIG. 4, the second imaging step S170 is a step in which the central control unit 150 drives the imaging unit 130 at the second position to image the inspection object 10. At this time, the central control unit 150 turns on the second light emitting unit 140. Further, the central control unit 150 turns off the first light emitting unit 120.

[Foreign matter depth determination step S180]
The foreign matter depth determination step S180 is a step in which the detection unit 152 analyzes the image obtained by the second imaging step S170 to detect the depth of the foreign matter C contained in the inspection object 10. In the present embodiment, the detection unit 152 binarizes the image and calculates the distance between the foreign matter C and the mirror image D on the image.

FIG. 5 is a diagram for explaining the difference in the distance between the foreign matter C and the mirror image D on the image according to the depth of the foreign matter C in the inspection object 10. FIG. 5A is a diagram for explaining the position P1 of the inspection object 10. FIG. 5B is a diagram illustrating an image when a foreign matter C is present at the position P1. FIG. 5C is a diagram for explaining the position P2 in the inspection object 10. FIG. 5D is a diagram illustrating an image when a foreign matter C is present at the position P2. FIG. 5E is a diagram for explaining the position P3 in the inspection object 10. FIG. 5F is a diagram for explaining an image when a foreign matter C is present at the position P3.

As shown in FIG. 5A, the position P1 is a predetermined position on the other surface of the inspection object 10, that is, the surface of the protective film 14 (the XY plane in FIG. 5A). The position P1 is separated from the surface of the mirror 110 in the Z-axis direction in FIG. Therefore, the position P1a on the mirror 110 on which the mirror image D is formed is separated from the position P1 of the foreign matter C in the Y-axis direction in FIG. Therefore, an optical path difference L1 is generated between the light Rc reflected by the foreign matter C and the light Rd reflected by the mirror image D. As a result, as shown in FIG. 5B, in the image 132, the foreign matter C and the mirror image D are separated by a distance L1a. The distance between the foreign matter C and the mirror image D in the image 132 is the distance between the end Ec of the foreign matter C and the end Ed corresponding to the end Ec of the foreign matter C in the mirror image D.

As shown in FIG. 5C, the position P2 is a predetermined position on one surface of the inspection object 10, that is, the contact surface with the mirror 110. The position P2 is substantially equal to the surface of the mirror 110 in the Z-axis direction in FIG. Therefore, the position P2a on the mirror 110 on which the mirror image D is formed is substantially equal to the position P2 of the foreign matter C. Therefore, the optical path difference between the light Rc reflected by the foreign matter C and the light Rd reflected by the mirror image D becomes substantially zero. As a result, as shown in FIG. 5D, the foreign matter C and the mirror image D are superimposed on the image 132. That is, when there is a foreign matter C at the position P2, the distance between the foreign matter C and the mirror image D in the image 132 becomes substantially zero.

As shown in FIG. 5E, the position P3 is a predetermined position in the inspection object 10. The position P3 is separated from the surface of the mirror 110 in the Z-axis direction in FIG. Therefore, the position P3a on the mirror 110 on which the mirror image D is formed is separated from the position P3 of the foreign matter C in the Y-axis direction in FIG. Therefore, an optical path difference L3 is generated between the light Rc reflected by the foreign matter C and the light Rd reflected by the mirror image D. As a result, as shown in FIG. 5F, in the image 132, the foreign matter C and the mirror image D are separated by a distance L3a.

Therefore, in the foreign matter depth determination step S180, the detection unit 152 first calculates the distance La (for example, the number of pixels) between the foreign matter C on the image 132 obtained by the second imaging step S170 and the mirror image D. Then, the detection unit 152 has a thickness T (length in the Z-axis direction in FIG. 5E), a distance L1a (for example, the number of pixels), and a second light emitting unit 140 of the inspection object 10 held in a memory (not shown). Depth of foreign matter C from the other surface (surface of the protective film 14) of the inspection object 10 using the following equations (1) and (2) based on the incident angle θ and the calculated distance La. Derivation of F.
W = La × cos θ… Equation (1)
F = T-W ... Equation (2)
In the above formula (1), W represents a distance (length in the Z-axis direction in FIG. 5E) from one surface (contact surface with the mirror 110) of the inspection object 10 to the foreign matter C. In the above formula (2), F represents the distance (the length in the Z-axis direction in FIG. 5E) from the other surface (the surface of the protective film 14) of the inspection object 10 to the foreign matter C.

Then, the central control unit 150 determines whether the depth F of the derived foreign matter C is on the surface of the inspection object 10 (protective film 14), inside the protective film 14, or between the protective film 14 and the transmission plate 12. To judge. As a result, the central control unit 150 determines that the depth F of the foreign matter C is the surface of the inspection object 10 (protective film 14), the inside of the protective film 14, or between the protective film 14 and the transmission plate 12 ( YES in S180), the process is transferred to the inspection end determination step S120. On the other hand, in the central control unit 150, when the depth F of the foreign matter C is not on the surface of the inspection object 10 (protective film 14), inside the protective film 14, or between the protective film 14 and the transmission plate 12 (S180). NO), the process is transferred to the rejection determination step S190.

[Failure determination step S190]
Returning to FIG. 2, the failure determination step S190 is a step in which the central control unit 150 determines that the inspection object 10 has failed. The inspection object 10 determined to be unacceptable is, for example, discarded.

[Pass determination step S200]
The pass determination step S200 is a step in which the central control unit 150 determines that the inspection object 10 has passed. The inspection object 10 determined to pass is transported or shipped to the next process.

As described above, the foreign matter detecting device 100 according to the present embodiment and the foreign matter detecting method using the foreign matter detecting device 100 include a mirror 110, an imaging unit 130, and a second light emitting unit 140. As a result, the foreign matter detection device 100 can measure the depth F of the foreign matter C with a simple configuration such that the image pickup unit 130 at the second position simply performs an image.

Further, the foreign matter detection device 100 can share the image pickup unit 130 (the image pickup unit 130 at the first position) for detecting the foreign matter C and the image pickup unit 130 for measuring the depth F of the foreign matter C. Therefore, the foreign matter detecting device 100 can detect the foreign matter C at low cost and measure the depth F of the foreign matter C.

Further, as described above, the mirror 110 is provided in contact with the inspection object 10. As a result, the imaging unit 130 can eliminate disturbance. Therefore, the imaging unit 130 can accurately image the foreign matter C and the mirror image D.

Further, as described above, the mirror 110 is a beam splitter. As a result, the foreign matter detecting device 100 can guide the light transmitted through the inspection object 10 to the imaging unit 130 at the first position. Therefore, the boundary of the foreign matter C can be clarified by the first light emitting unit 120, and the accuracy of determining the presence or absence of the foreign matter C in the foreign matter presence / absence determination step S150 can be improved. Therefore, the foreign matter detecting device 100 can efficiently determine the presence or absence of the foreign matter C and measure the depth F of the foreign matter C.

Further, as described above, the detection unit 152 sets the distance between the end Ec of the foreign matter C in the image 132 and the end Ed of the mirror image D as the distance between the foreign matter C and the mirror image D in the image 132. As a result, the detection unit 152 can accurately measure the distance between the foreign matter C and the mirror image D in the image 132 regardless of the shape of the foreign matter C.

[Modification example]
In the above embodiment, the configuration in which the foreign matter detecting device 100 includes the mirror 110 is given as an example. However, depending on the configuration of the inspection object 20, the mirror 110 can be omitted. FIG. 6 is a diagram illustrating a foreign matter detecting device 200 of a modified example. In FIG. 6, the dashed arrow indicates the signal flow. In FIG. 6, the alternate long and short dash line indicates light. As shown in FIG. 6, the foreign matter detecting device 200 includes a first light emitting unit 120, an imaging unit 130, a second light emitting unit 140, and a central control unit 150. The components substantially the same as the foreign matter detecting device 100 are designated by the same reference numerals and the description thereof will be omitted.

In the modified example, the inspection object 20 includes a transmission plate 12 and a protective film 24. The protective film 24 is provided in contact with one surface side of the transmission plate 12. In a modified example, the protective film 24 is a beam splitter. That is, in the foreign matter detecting device 200 of the modified example, the protective film 24 that is peeled off when the inspection object 20 (transmissive plate 12) is used functions as the mirror 110 of the foreign matter detecting device 100.

As a result, the foreign matter detecting device 200 measures the depth F of the foreign matter C with a simple configuration such that the image pickup unit 130 at the second position only takes an image of the inspection object 20 without the mirror 110. be able to.

Although the embodiments have been described above with reference to the accompanying drawings, it goes without saying that the present disclosure is not limited to the above embodiments. It is clear to those skilled in the art that various modifications or modifications can be conceived within the scope of the claims, and it is understood that they also naturally belong to the technical scope of the present disclosure. Will be done.

For example, in the above-described embodiments and modifications, the case where the mirror 110 and the protective film 24 are composed of a beam splitter has been described as an example. However, the mirror 110 or the protective film 24 may totally reflect the incident light, or may reflect a part of the incident light and absorb a part of the incident light. In this case, the first light emitting unit 120 is provided on the other side of the inspection objects 10 and 20, that is, on the same side as the imaging unit 130.

Further, in the above embodiment, the case where the inspection object 10 (transmission plate 12) is a flat plate is taken as an example. However, the transmission plate 12 may be curved. In this case, the mirror 110 may be made of a flexible material. Further, at this time, the mirror 110 may be pressed against the transmission plate 12 by air or the like.

Further, in the above embodiment, the case where the mirror 110 is provided in contact with the inspection object 10 is given as an example. However, the mirror 110 and the inspection object 10 may be separated from each other. In this case, T is a value obtained by adding the separation distance between the mirror 110 and the inspection object 10 to the thickness of the inspection object 10.

Further, in the above embodiment, the distance between the end Ec of the foreign matter C in the image 132 and the end Ed of the mirror image D is defined as the distance between the foreign matter C and the mirror image D in the image 132. However, the distance between the center of gravity of the foreign matter C in the image 132 and the center of gravity of the mirror image D may be the distance between the foreign matter C and the mirror image D in the image 132.

Further, in the above embodiment, the configuration in which the imaging unit 130 is fixed at the first position and the second position and the inspection object 10 and the mirror 110 are moved is given as an example. However, the inspection object 10 and the mirror 110 may be fixed, and the imaging unit 130 may be moved (scanned) at the first position and the second position.

Further, in the above embodiment, the case where the first light emitting unit 120 and the second light emitting unit 140 irradiate visible light is given as an example. However, the first light emitting unit 120 and the second light emitting unit 140 may irradiate light in the wavelength band from infrared rays to ultraviolet rays. In this case, the imaging unit 130 only needs to be able to receive the light emitted by the first light emitting unit 120 and the second light emitting unit 140 and the reflected light of the light. Further, the first light emitting unit 120 and the second light emitting unit 140 may irradiate electromagnetic waves. In this case, the imaging unit 130 only needs to be able to receive electromagnetic waves.

Further, in the above embodiment, the case where the inspection object 10 includes the protective film 14 is given as an example. However, the inspection object 10 may include at least a transmission plate 12. In this case, the foreign matter detecting device 100 detects the depth F of the foreign matter C adhering to the transmission plate 12 and the foreign matter C contained in the transmission plate 12 (foreign matter C contained in the transmission plate 12).

It should be noted that each step of the foreign matter detection method of the present specification does not necessarily have to be processed in chronological order in the order described as a flowchart, and may include processing in parallel or by a subroutine.

The present disclosure can be used for a foreign matter detecting device and a foreign matter detecting method.

C Foreign matter D Mirror image 12 Transmission plate 20 Inspection object 24 Protective film 100 Foreign matter detection device 110 Mirror 130 Imaging unit 140 Second light emitting unit (light emitting unit)
152 Detection unit 200 Foreign matter detection device S110 Installation process S170 Second imaging step S180 Foreign matter depth determination step

Claims (4)

A mirror provided on one side of the transmission plate and
A light emitting portion provided on the other surface side of the transmission plate and
An imaging unit provided on the other surface side of the transmission plate and
A detection unit that detects the depth of the foreign matter contained in the transmission plate based on the distance between the foreign matter and the mirror image of the foreign matter projected on the mirror in the image captured by the imaging unit.
Foreign matter detection device. The foreign matter detection device according to claim 1, wherein the mirror contacts one surface of the transmission plate. A light emitting portion provided on the other surface side of the inspection object including the transmission plate and a mirror provided in contact with one surface side of the transmission plate.
An imaging unit provided on the other surface side of the inspection object and
A detection unit that detects the depth of the foreign matter contained in the inspection object based on the distance between the foreign matter and the mirror image of the foreign matter projected on the mirror in the image captured by the imaging unit.
Foreign matter detection device. The process of installing a mirror on one side of the transparent plate and
The step of irradiating light from the other surface side of the transmission plate and
The step of imaging from the other surface side of the transmission plate and
A step of detecting the depth of the foreign matter contained in the transmission plate based on the distance between the mirror image of the foreign matter projected on the mirror and the foreign matter in the image captured in the imaging step.
Foreign matter detection method including.

Images