TW201339569A - Defect testing method - Google Patents

Abstract

A defect testing method is provided, which tests for the existence of defects in a tested sample by a defect testing device. The defect testing device includes an illuminating device, a line sensor camera and a plate-shaped light shielding component. A central area and an end area are disposed in the light shielding component. In a moving direction X of the tested sample, the central area has a straight line-shaped margin as an edge and covers a light-emitting surface partially, wherein the straight line-shaped margin intersects with a moving direction of the tested sample by a predetermined angle. In the end area, a hole of a predetermined pattern is formed at the light shielding area covering overall the end area of the light-emitting surface on the moving direction of the tested sample. The tested sample is evaluated for the existence of defects in the central area, and a relative position of the light shielding component relative to the line sensor camera is tested in the end area.

Description

Defect inspection method

The present invention relates to a defect inspection method.

For the presence or absence of a defect in a transparent web or sheet-like object, an online inspection can be performed in a non-contact manner. The line inspection is performed by continuously moving the subject, scanning light in the width direction, or illuminating a line-like light that traverses the width direction, and photoelectrically monitoring the source. The level of transmitted light of the specimen changes. Regarding the defect to be inspected, there are various defects such as pin holes, granules, scratches, or optical strain depending on the material, quality grade, or use of the product.

In the inspection apparatus of the Japanese Patent No. 4,132,046, the moving transparent transparent sheet is used as the object, and an illumination device having a light-emitting surface elongated in the width direction is disposed on the lower surface side of the transparent sheet. And a line sensor camera is disposed on the upper surface side. The illuminating device has a light-shielding plate that partially shields the light-emitting surface from the light-emitting surface in such a manner that the edge of the light-shielding plate is parallel to the longitudinal direction of the light-emitting surface. Group into line sensor phase The arrangement direction of the pixels of the line sensor of the machine is aligned in parallel with the edge of the visor. Adjust the optical axis of the camera in a manner consistent with the edge of the visor. Also, the focus of the line sensor camera is aligned near the surface of the subject. Therefore, on the line sensor, the boundary between the light and the dark due to the edge of the visor becomes blurred and unclear, and when the subject is a normal transparent body, the bright and dark portions due to the visor The middle 50% concentration of gray light is incident on the line sensor.

According to the above-described inspection apparatus using a visor, if there is no defect in the subject, a photoelectric signal corresponding to 50% of gray light can be obtained from the line sensor over the full width of the subject. On the other hand, when the subject contains certain defects, the photoelectric signal obtained from the line sensor changes due to light absorption or light scattering or the like. Further, in the process in which the defective portion passes through the edge of the light shielding plate, a density pattern corresponding to the type of the defect appears in the moving direction and the width direction of the subject. According to this method, the change of the inspection light obtained in the process of passing the defective portion is obtained as two-dimensional pattern information, and the change in the inspection light can also be used as information for discriminating the type of the defect. Moreover, in order to obtain pattern information of the intensity change of the inspection light in the width direction with high precision, it is necessary to increase the resolution of each pixel of the line sensor.

On the other hand, in the above-described inspection apparatus, it is generally used in a standard setting in which the optical axis of the line sensor camera is aligned with the edge of the light shielding plate. However, even if it is initially set as a standard, during the period of repeated use, there may be a case where a part of the configuration of the inspection device, for example, a frame or a bracket supporting the illumination device or the line sensor camera. Deformed due to changes in ambient temperature, etc. As a result, the optical axis of the wired sensor camera may be deviated from the edge of the visor, or the direction in which the pixel of the line sensor is arranged may be lost in parallel with the edge.

Thus, if the boundary line of the light and dark due to the edge of the visor is offset with respect to the line sensor, the result is that the photoelectric output obtained from the line sensor increases or decreases according to the direction of the offset. Therefore, the accuracy of the defect inspection is reduced. In particular, if the pixel size is reduced in order to increase the resolution of each pixel of the line sensor, the sensitivity with respect to the spatial positional shift becomes sensitive, and thus the standard setting is made. It is impossible to detect the photoelectric signal that can be detected at an appropriate level, and it is difficult to maintain the inspection accuracy stable. Further, with respect to the variation in the amount of light of the illumination device itself, the stabilization of the amount of light can be achieved by ordinary feedback control. However, the variation in the amount of light accompanying the change in the relative position of the optical axis of the camera and the edge of the visor cannot be handled by the light amount control of the illumination device.

Therefore, an object of the present invention is to provide a defect inspection method in which a subject such as a transparent sheet is continuously moved while irradiating light to one side thereof, and the line sensor camera passes over the edge of the light shielding plate. When the inspection light transmitted from the other surface is received to check for the presence or absence of the defect, the edge of the visor is prevented from shifting with respect to the optical axis of the line sensor camera or tilted around the optical axis, thereby keeping the inspection accuracy stable.

In order to achieve the above object, the defect inspection method of the present invention includes a continuous moving step, an irradiation step, a setting step, a light receiving step, and an evaluation step. The continuous moving step is to continuously move the transparent mesh or sheet-like subject. The illuminating step is a test in which the illuminating device of the illuminating device having a rectangular illuminating surface is continuously moved. One side of the body illuminates the light. The long side of the light emitting surface is a length exceeding the width of the subject. The longitudinal direction of the light-emitting surface of the illumination device is arranged at a predetermined angle in the moving direction of the subject. The setting step is to arrange the light shielding plate between the light emitting surface and the object in a state of being positioned. The visor includes a central area and an end area. The central region integrally covers the light-emitting surface in the width direction of the subject, and partially covers the light-emitting surface at a boundary between the moving edge of the subject and the linear edge intersecting at a predetermined angle with the moving direction. The end region is formed with a through hole having a predetermined pattern in a light-shielding region in which the end portion of the light-emitting surface is entirely covered in the moving direction of the subject. The visor is positioned in such a way that the edge of the visor is aligned with the optical axis of the line sensor camera. The light receiving step is to receive the inspection light transmitted through the subject and the end light from the end of the light emitting surface outside the width of the subject by the line sensor of the line sensor camera. The line sensor camera is disposed so as to face the other side of the subject, and the arrangement direction of the pixels of the line sensor is made parallel to the longitudinal direction of the light emitting surface. The evaluation step is based on evaluating the presence or absence of defects of the subject based on the photoelectric signals of the central region obtained from the line sensor camera, and evaluating the relative position of the visor relative to the line sensor camera based on the photoelectric signals of the end regions.

Preferably, referring to both the photoelectric signal of the central region and the photoelectric signal of the end region, the visor is evaluated by whether the optical axis of the visor relative to the optical axis of the line sensor camera is shifted from the standard position to the moving direction of the object. Relative position relative to the line sensor camera.

Preferably, the relative position of the visor relative to the line sensor camera is evaluated by comparing the relative parallelism of the arrangement direction of the pixels of the line sensor camera with the edge of the visor.

Preferably based on the relative position of the visor relative to the line sensor camera As a result of the evaluation, a misalignment warning is issued when the edge of the visor is not aligned with the optical axis of the line sensor camera.

Preferably, based on the evaluation result of the relative position of the visor relative to the line sensor camera, the illuminating plate is aligned with the optical axis using an adjustment unit such that the edge of the visor and the optical axis of the line sensor camera The alignment is mechanically or optically adjusted.

Preferably, the optically adjusted adjustment unit rotates the transparent member having a uniform refractive index and a thickness which are provided so as to cover the entire width direction of the subject. Preferably, a concave cylindrical lens is provided on the optical path of the end light between the subject and the light shielding plate. It is preferable to adjust the amount of light irradiated from the illumination device such that the photoelectric signal intensity in the central region is substantially constant.

According to the present invention, the presence or absence of a defect of the object can be evaluated based on the photoelectric signal obtained from the central region, and the relative position of the visor relative to the line sensor camera can be detected based on the photoelectric signal obtained from the end region. Therefore, it is possible to prevent the edge of the light shielding plate from being displaced with respect to the optical axis of the line sensor camera or tilting about the optical axis, so that the inspection accuracy can be kept stable.

2, 60, 70‧‧‧ defect inspection device

3‧‧‧The subject

3A, 3D‧‧‧ Defects

3B, 3C‧‧‧Dark defects

4‧‧‧Lighting device

4A‧‧‧Lighting surface

4B‧‧‧Lighting diode

4C‧‧‧Diffuser

6‧‧‧ line sensor camera

6A‧‧ lens

6B‧‧‧ line sensor

8‧‧‧ shading members

8A‧‧‧ edge

10‧‧‧ optical axis

11‧‧‧System Controller

12‧‧‧Light intensity adjustment department

14‧‧‧ Camera Action Department

16‧‧‧Signal Processing Department

18‧‧‧Defect Determination Department

19‧‧‧Defect Display Department

21‧‧ ‧ visor position detection department

22‧‧‧Warning Department

23‧‧ ‧ visor position adjustment department

25‧‧ Record Department

27A, 27B, 27C, 27D‧‧‧ Determination line

30, 40, 50‧ ‧ visors

30A, 50A‧‧‧ edge

30B, 50B‧‧‧Central Area

30C, 50C‧‧‧ end area

30D, 50D1, 50D2, 50D3, 50D4‧‧ slit

32A, 32B, 34A, 34B, 36A, 36B, 38A, 38B, 40A, 40B, 40C, 40D, 42A, 42B, 42C, 42D, 44A, 44B, 44C, 44D, 46A, 46B, 46C, 46D, 48A, 48B, 48C, 48D, 52A, 52B, 54A, 54B, 56A, 56B, 58A, 58B‧‧‧ Signal strength

62‧‧‧Transparent components

72‧‧‧ concave cylindrical lens

P‧‧‧Normal signal

Q‧‧‧ Defect signal

X‧‧‧ moving direction

Fig. 1 is a schematic perspective view of a defect inspection device according to an embodiment of the present invention.

Figure 2 is a cross-sectional view of the defect inspection device of Figure 1.

3 is an explanatory view of a defect inspection example of the defect inspection device according to the embodiment of the present invention.

4(A) and 4(B) are views for explaining a first embodiment of a light shielding member used in the defect inspection device according to the embodiment of the present invention.

FIG. 5 is a view for explaining a change in a signal of a line sensor with respect to a change in an optical axis surface in the first embodiment of the light shielding member used in the defect inspection device according to the embodiment of the present invention.

6(A) and 6(B) are views for explaining a second embodiment of a light shielding member used in the defect inspection device according to the embodiment of the present invention.

FIG. 7 is a view for explaining a change in a signal of a line sensor with respect to a change in an optical axis surface, in a second embodiment of a light shielding member used in the defect inspection device according to the embodiment of the present invention.

8(A) and 8(B) are views for explaining a third embodiment of a light shielding member used in the defect inspection device according to the embodiment of the present invention.

FIG. 9 is a view for explaining a change in a signal of a line sensor with respect to a change in an optical axis surface, in a third embodiment of a light shielding member used in the defect inspection device according to the embodiment of the present invention.

Fig. 10 is a cross-sectional view showing another defect inspection device according to an embodiment of the present invention.

Fig. 11 is a schematic perspective view of another defect inspection device according to an embodiment of the present invention.

Figure 12 is a cross-sectional view of the defect inspection device of Figure 11 .

As shown in Fig. 1, the defect inspection device 2 of the present invention continuously moves a transparent mesh or sheet-like subject 3, and irradiates light to one surface of the subject 3 based on the transmitted subject 3 Check the light to check the subject for defects. As The subject 3 includes, for example, a film, a glass, and the like. The defect inspection device 2 includes an illumination device 4, a line sensor camera 6, and a plate-shaped light shielding member 8. The illuminating device 4 is provided on one side (the lower side in the drawing) of the subject 3, and illuminates the subject 3 with light. The line sensor camera 6 is disposed on the opposite side (upper side of the drawing) of the illumination device 4 with respect to the subject 3, and receives inspection light. The light shielding member 8 is provided between the subject 3 and the illumination device 4, and partially shields the light irradiated from the illumination device 4.

The illuminating device 4 has a rectangular light-emitting surface 4A that is longer than the width of the subject 3, and is disposed such that the longitudinal direction of the light-emitting surface 4A is orthogonal to the moving direction X of the subject 3. The light emitting surface 4A is parallel to the passed subject 3 . The width of the subject 3 refers to the length of the subject 3 in a direction orthogonal to the moving direction of the subject 3 . Further, as shown in FIG. 2, in the illumination device 4, a plurality of light-emitting diodes 4B are arranged side by side in the longitudinal direction of the light-emitting surface 4A toward the light-emitting surface 4A, and are provided on the light-emitting surface 4A side. Diffuser plate 4C. Therefore, the illumination device 4 irradiates light having a small coordinate dependency of the luminous intensity from the light-emitting surface 4A. Further, other light-emitting elements may be used instead of the light-emitting diodes 4B.

As shown in FIG. 2, the line sensor camera 6 has a lens 6A and a line sensor 6B. The line sensor 6B includes a plurality of sensors (not shown) and the like arranged in a line in the width direction of the subject 3, and receives light from a linear inspection region having a fixed width. The lens 6A of the line sensor camera 6 is disposed to face the light-emitting surface 4A, and the optical axis of the lens 6A and the optical axis 10 of the line sensor camera 6 pass through the light-emitting surface 4A in the moving direction X of the subject 3 center. The light irradiated from the illumination device 4 to the subject 3 passes through the subject 3 and is received by the respective sensors of the line sensor 6B via the lens 6A, and is converted into an electro-optical signal. Further, the focus of the line sensor camera 6 is aligned with the surface of the subject 3.

Moreover, the light shielding member 8 integrally covers the light emitting surface 4A in the width direction of the subject 3. The light shielding member 8 includes a central region that partially covers the light-emitting surface 4A with a linear edge 8A orthogonal to the movement direction X in the moving direction X of the subject 3, and an end region. A through hole in which a predetermined pattern is formed in a light-shielding region in which the end portion of the light-emitting surface is entirely covered in the moving direction of the subject. The details of the central area and the end area are described below using other drawings. The light shielding member 8 is positioned in a state where the edge 8A is aligned with the optical axis 10 of the line sensor camera 6. For the light-shielding member 8, for example, the light-shielding plate 30 (see FIGS. 4(A), 4(B), and 5) of the first embodiment, and the light-shielding plate 40 of the second embodiment are used (see FIG. 6(A), 6(B), 7) or the light shielding plate 50 of the third embodiment (see FIGS. 8(A), 8(B), and 9). The first, second, and third embodiments will be specifically described below.

Here, a case where the subject 3 is a mesh-shaped transparent film will be described as an example. However, the subject 3 may be a non-retic transparent film or a transparent glass plate or the like, and may be other articles as long as the required conditions are satisfied. In the case where the subject 3 is a mesh-shaped transparent film, a supply roller such as a mesh-shaped transparent film is provided, and a roll of the transparent film is provided in order to stably move the subject 3 in one direction. A conveying system such as a roller and a conveying roller of the transparent film.

Further, as shown in FIG. 1, the defect inspection device 2 of the present invention includes a system controller 11, a light intensity adjustment unit 12, a camera operation unit 14, a signal processing unit 16, a defect determination unit 18, and a defect display unit. 19. The system controller 11 controls the overall system of the defect inspection device 2. The light intensity adjustment unit 12 adjusts the light intensity radiated from the illumination device 4. The camera action unit 14 operates the line sensor camera 6. The signal processing unit 16 pairs the light obtained by the line sensor 6B of the line sensor camera 6 The electrical signal is processed. The defect determination unit 18 determines the defect of the subject 3 based on the processing result of the photoelectric signal in the central region. The defect display unit 19 displays the defect of the subject 3 determined by the defect determination unit 18. Moreover, as shown in FIG. 1, the defect inspection apparatus 2 includes the visor position detecting unit 21, the alarm unit 22, the visor position adjusting unit 23, and the recording unit 25. The visor position detecting unit 21 detects the position of the light shielding member 8 based on the processing result of the photoelectric signal in the end portion. The alarm portion 22 issues an alarm indicating misalignment when the edge 8A of the light shielding member 8 is not aligned with the optical axis 10 of the line sensor camera 6. The visor position adjusting portion 23 mechanically or optically adjusts the light shielding member 8 and the line sensor camera 6 to a state in which the edge 8A of the light shielding member 8 is aligned with the optical axis 10 of the line sensor camera 6. In this adjustment, the light shielding plate position adjusting portion 23 adjusts at least one of the posture of the light shielding member 8 and the inspection region of the line sensor camera 6 to a state in which the edge 8A is parallel to the linear inspection region. The state in which the edge 8A is aligned with the inspection region refers to a state in which the edge 8A enters the inspection region when the light shielding member 8 is observed from the line sensor camera 6. The recording unit 25 records the signal-processed photoelectric signal, the light intensity information of the illumination device 4, the position information of the light-shielding member 8, and the like. Furthermore, the alarm issued by the alarm unit 22 may be any alarm such as an alarm using sound or an alarm using light.

The photoelectric signal in the central region in the case where the subject 3 has the bright defect 3A, the bright defect 3D, the dark defect 3B, and the dark defect 3C will be described with reference to FIG. The bright defect 3A and the bright defect 3D are portions where the intensity of the photoelectric signal obtained by the portion of the subject 3 that does not have a defect is obtained. The dark defect 3B and the dark defect 3C are portions which obtain a weaker intensity than the photoelectric signal obtained by passing through the portion having no defect. Photoelectricity in the central region on the measurement line (A), the measurement line (B), the measurement line (C), the measurement line (D), and the measurement line (E) across the defect The signals are as shown in (A), (B), (C), (D), and (E) of Fig. 3, respectively. As shown in (F) of FIG. 3, the photoelectric signal in the central region on the measurement line (F) that does not cross the defect is a straight line having no fixed level such as a peak. More specifically, when the bright portion of the edge 8A of the light-shielding member 8 is set to a white color having a concentration of 0% and the dark portion is set to a black color having a density of 100%, the subject 3 is normally inspected without defects. In the case of the body 3, the normal signal P maintained at the normal signal level can be obtained throughout the full width of the subject 3. This normal signal level corresponds to a gray photoelectric signal of 50% concentration obtained from the line sensor 6B. On the other hand, when the subject 3 is defective, as shown in FIG. 3 (A) to FIG. 3 (E), each defect signal Q can be obtained at the corresponding portion of the subject 3. In the defect inspection device 2 of the present invention, the photoelectric signals are processed and expressed as a two-dimensional pattern or a line scan image having a density distribution, thereby detecting a bright defect 3A in the subject 3, Defect 3D and dark defect 3B, dark defect 3C. Furthermore, the measurement line is the above-described inspection area.

As shown in FIG. 4(A), the light shielding plate 30 of the first embodiment as the light shielding member 8 includes a central portion 30B having an edge 30A and an end portion 30C provided at both ends in the width direction of the light shielding plate 30. The width direction of the light shielding plate 30 is a direction that coincides with the longitudinal direction of the light-emitting surface 4A, and is also the same for each of the light shielding plate 40 and the light shielding plate 50 described below. The end regions 30C each include a light-shielding region; and a slit 30D having a fixed length spanning the extension of the edge 30A and having a fixed width.

In the width direction of the light shielding plate 30, the subject 3 is evaluated for the presence or absence of defects in the central portion 30B provided with the edge 30A, and the relative position of the light shielding plate 30 with respect to the line sensor camera 6 is evaluated at the end portion region 30C. Further, the measurement line 27A indicates that the edge 30A is orthogonal to the moving direction X of the subject 3 and the optical axis 10 of the line sensor camera 6 The measurement line at the time of alignment, that is, the measurement line when the visor 30 is in an appropriate position at the time of inspection.

In the first embodiment, when the measurement line is the measurement line 27A, the line sensor camera 6 obtains the photoelectric signal as shown in FIG. 4(B). For the photoelectric signal, in the central region 30B, the signal intensity at the defect-free position is 32 A, and a photoelectric signal having a stronger signal intensity 32A can be obtained at a position where the defect 3A and the bright defect 3D are present, and there is a dark defect 3B, dark. The position of the defect 3C can obtain a photoelectric signal that is weaker than the signal intensity 32A. Further, in the end portion region 30C, the photoelectric signal is not obtained in the light-shielding region, and the photoelectric signal 32B far stronger than the signal intensity 32A can be obtained in the region having the slit 30D.

As shown in FIG. 6(A), the light shielding plate 40 of the second embodiment as the light shielding member 8 includes a central portion 40B having an edge 40A and an end portion 40C provided at both ends in the width direction of the light shielding plate 40. Each of the end regions 40C includes a light-shielding region, and a wedge-shaped void 40D that extends across the extension line of the edge 40A and continuously changes in the moving direction X of the subject 3 .

In the width direction of the light shielding plate 40, the subject 3 is evaluated for the presence or absence of defects in the central portion 40B provided with the edge 40A, and the relative position of the light shielding plate 40 with respect to the line sensor camera 6 is evaluated at the end portion region 40C. In the same manner as in the first embodiment, the measurement line 27A is a measurement line indicating that the edge 40A is orthogonal to the movement direction X of the subject 3 and aligned with the optical axis 10 of the line sensor camera 6, that is, the visor 40 A measurement line when it is in the proper position at the time of measurement.

In the second embodiment, when the measurement line is 27A, the line sensor camera 6 obtains the photoelectric signal as shown in Fig. 6(B). For the photoelectric signal, in the central region 40B, the signal intensity at the defect-free position is 42 A, and there is a clear defect 3A, The position of the bright defect 3D can obtain a photoelectric signal stronger than the signal intensity 42A, and a photoelectric signal weaker than the signal intensity 42A can be obtained at the position where the dark defect 3B and the dark defect 3C are present. Further, in the end portion region 40C, the photoelectric signal is not obtained in the light-shielding region, and the signal intensity 42B having a signal intensity of 42 A and a signal width of 42 C can be obtained in the region having the wedge-shaped void 40D.

As shown in FIG. 8(A), the light shielding plate 50 of the third embodiment as the light shielding member 8 includes a central portion 50B having an edge 50A and an end portion 50C provided at both ends in the width direction of the light shielding plate 50. The end region 50C is provided with a light-shielding region, and the slit 50D1, the slit 50D2, the slit 50D3, and the slit 50D4 have a fixed length in the moving direction X of the subject 3 and have a fixed width. The slit 50D1, the slit 50D2, the slit 50D3, and the slit 50D4 are provided in this order from the central portion 50B side, and the length of the moving direction of the subject 3 changes in accordance with the order. The slit 50D1 and the slit 50D2 are designed to extend across the length of the extension of the edge 50A, and the slit 50D3 and the slit 50D4 are designed to be shorter than the extension of the edge 50A.

In the width direction of the visor 50, the subject 3 is evaluated for presence or absence of defects in the central portion 50B provided with the edge 50A, and the relative position of the visor 50 with respect to the line sensor camera 6 is evaluated at the end portion 50C. Further, similarly to the first and second embodiments, the measurement line 27A is a measurement line indicating that the edge 50A is orthogonal to the moving direction of the subject 3 and aligned with the optical axis 10 of the line sensor camera 6, that is, The measurement line when the visor 50 is in an appropriate position at the time of measurement.

In the third embodiment, when the measurement line is 27A, the line sensor camera 6 obtains the photoelectric signal as shown in Fig. 8(B). For the photoelectric signal, in the central region 50B, the signal intensity at the defect-free position is 52 A, and there is a defect 3A, The position of the 3D of the defect is obtained as a photoelectric signal stronger than the signal intensity 52A, and a photoelectric signal having a weaker signal intensity 52A can be obtained at the position where the dark defect 3B and the dark defect 3C are present. Further, in the end portion region 50C, the photoelectric signal is not obtained in the light-shielding region, and the signal intensity 52B far stronger than the signal intensity 52A can be obtained in the region having the slit 50D1 and the slit 50D2. On the other hand, in the region having the slit 50D3 and the slit 50D4, the photoelectric signal cannot be obtained in the same manner as the light-shielding region.

Hereinafter, the action of the present invention will be described. First, the mesh-shaped transparent film as the subject 3 is stably moved in the longitudinal direction by the transport system provided in the defect inspection device 2 of the present invention. For example, the mesh-shaped transparent film as the subject 3 moves at a constant speed from the lower right direction in FIG. 1 toward the upper left direction, and passes between the defect inspection devices 2 at a constant speed.

As shown in FIG. 1 and FIG. 2, when the light shielding member 8 is disposed at a relatively appropriate position with respect to the line sensor camera 6 with respect to the line sensor camera 6 so that the edge 8A overlaps with the optical axis 10, the self-illuminating device 4 The light-emitting surface 4A irradiates light to one surface of the subject 3 via the light-shielding member 8, and the inspection light transmitted through the subject 3 is received by the line sensor 6B via the lens 6A disposed in the line sensor camera 6, and is converted. Obtained for photoelectric signals. Further, the illumination device 4 controls the illumination intensity such that the signal intensity 32A, the signal intensity 42A, and the signal intensity 52A are always fixed by the light intensity adjustment unit 12 controlled by the system controller 11. Further, the line sensor camera 6 receives, converts, and acquires the camera operation unit 14 controlled by the system controller 11.

The photoelectric signal obtained by the line sensor 6B is applied to the signal processing unit 16 The processing is performed in such a manner as to be distributed in the plane, and the processing result is recorded in the recording unit 25. Further, according to the photoelectric signals of the central region 30B, the central region 40B, and the central region 50B, the detection conforms to a clear defect (for example, symbol 3A and symbol 3D in FIG. 3). The waveform of the dark defect (for example, symbol 3B and symbol 3C in FIG. 3) is determined by the defect determining unit 18 as a defect. Then, on the defect display unit 19, the portion determined to be defective, the type of the defect, and the like are displayed on the display.

Further, the light shielding plate position detecting unit 21 detects the light shielding plate 30, the light shielding plate 40, and the light shielding plate 50 with respect to the line sensor camera 6 based on the photoelectric signals of the end portion region 30C, the end portion region 40C, and the end portion region 50C. The relative position of the optical axis 10. If the relative position is not a position suitable for inspection, an alarm is issued by the alarm unit 22, and the relative position is mechanically or optically adjusted by the visor position adjusting unit 23. As a method of position adjustment, there is a method of moving the light shielding plate 30, the light shielding plate 40, and the light shielding plate 50 to a mechanical position at an appropriate relative position, which is suitable for inspection, and moving the optical axis 10 to the optical member 10 using the optical member. An optical method or the like suitable for the position to be inspected. Hereinafter, a method of detecting the position of each of the light shielding plate 30, the light shielding plate 40, and the light shielding plate 50 will be described.

Here, the measurement line 27B shown in FIG. 5, FIG. 7, and FIG. 9 is a measurement line when the edge 30A is shifted in parallel from the measurement line 27A to one side of the light shielding plate 30, and the measurement line 27C is relative to the measurement. The line 27A is a measurement line when it is shifted to the side opposite to the measurement line 27B. In addition, the measurement line 27D is a measurement line when the measurement line 27A is shifted counterclockwise around the midpoint of the edge 30A (the center in the lateral direction of the drawing). The measurement line 27B, the measurement line 27C, and the measurement line 27D are measurement lines that are not aligned with the optical axis 10 of the line sensor camera 6.

When the light shielding plate 30 of the first embodiment is used for the light shielding member 8, a change in the photoelectric signal caused by a change in the measurement line will be described with reference to FIG. 5 . The photoelectric signal in the case of the measurement line 27A is as shown in FIG. 5(A) as described above. At the moment when the measurement line is shifted from 27A to 27B, the center The signal strength 34A of the region 30B is reduced compared to the signal strength 32A, and the signal strength 34B of the end region 30C is maintained such that the signal strength 32B does not change. Immediately thereafter, the light intensity adjusting unit 12 adjusts the illumination intensity of the illumination device 4 in a direction in which the signal intensity 34A is equal to the signal intensity 32A. Corresponding to this, the signal strength 34B becomes smaller than the signal strength 32. As a result, the photoelectric signal in the case of the measurement line 27B is as shown in FIG. 5(B).

The photoelectric signal in the case of the measurement line 27C is changed completely opposite to the measurement line 27B, so that the signal intensity 36A of the central region 30B is equal to the signal intensity 32A, and the illumination intensity of the illumination device 4 is adjusted in the weakened direction. . Corresponding to this, the signal intensity 36B of the end region 30C becomes larger than the signal strength 32. As a result, the photoelectric signal in the case of the measurement line 27C is as shown in FIG. 5(C).

The photoelectric signal in the case of the measurement line 27D generates a width direction coordinate dependency in the signal intensity 38A of the central region 30B. Further, the signal intensity 38 is equal to the signal intensity 38A when the average value of the width direction coordinates is taken, so that the illumination intensity of the illumination device 4 is not particularly adjusted. Therefore, the signal strength 38B of the end region 30C does not change from the signal strength 32B. As a result, the photoelectric signal in the case of the measurement line 27D is as shown in (D) of FIG. 5 .

According to the above, the direction and size of the deviation of the measurement line with respect to the optical axis 10 due to the parallel movement can be based on the signal intensity of the end portion 30C relative to the measurement line at the signal intensity 32B at 27A. And read. When it is less than the signal intensity 32B, the measurement line can be read in the direction of 27B. When it is greater than the signal intensity 32B, the measurement line can be read in the direction of 27C, and can be read according to the intensity difference from the signal strength 32B. Offset width. Also, for the measurement line relative to The offset caused by the rotational movement of the optical axis can be read according to the width direction coordinate dependence of the signal intensity in the central region 30B. In this way, the offset caused by the parallel movement and the rotational movement of the measurement line with respect to the optical axis can be read based on the photoelectric signal.

When the light shielding plate 40 of the second embodiment is used for the light shielding member 8, a change in the photoelectric signal caused by a change in the measurement line will be described with reference to FIG. 7 . The photoelectric signal in the case of the measurement line 27A is as shown in FIG. 7(A) as described above. At the moment when the measurement line is shifted from 27A to 27B, the signal intensity 44A of the central region 40B is reduced compared to the signal intensity 42A, and the signal intensity 44B of the end region 40C is maintained at the signal intensity 42B. On the other hand, the signal width 44C and the signal width 44D of the end region are wider than the signal width 42C and the signal width 42D, respectively. Immediately thereafter, the light intensity adjusting unit 12 adjusts the illumination intensity of the illumination device 4 in a direction in which the signal intensity 44A becomes equal to the signal intensity 42A. Accordingly, the signal intensity 44B becomes smaller than the signal intensity 42B. . As a result, the photoelectric signal in the case of the measurement line 27B is as shown in FIG. 7(B).

The photoelectric signal in the case of the measurement line 27C is changed completely opposite to the measurement line 27B, and the illumination intensity of the illumination device 4 is adjusted in a weakened direction so that the signal intensity 46A of the central region 40B becomes equal to the signal intensity 42A. Corresponding to this, the signal intensity 46B of the end region 40C becomes larger than the signal strength 42B. On the other hand, the signal width 46C and the signal width 46D of the end region are narrower than the signal width 42C and the signal width 42D, respectively. As a result, the photoelectric signal in the case of the measurement line 27C is as shown in FIG. 7(C).

The photoelectric signal at the time of the measurement line 27D generates a width direction coordinate dependency in the signal intensity 48A of the central region 40B. Also, for signal strength 48A, If the average value of the coordinates in the width direction is equal to the signal intensity 42A, the illumination intensity of the illumination device 4 is not particularly adjusted. Therefore, the signal strength 48B of the end region 40C does not change from the signal strength 42B. On the other hand, for the signal width of the end region, on the one hand, the signal width 48C is wider than the signal width 42C, and on the other hand, the signal width 48D is narrower than the signal width 42D. That is, when the measurement line is displaced with respect to the optical axis due to the rotational movement, a difference occurs in the respective signal widths 48C, 48D of the end portion region 40C. As a result, the photoelectric signal in the case of the measurement line 27D is as shown in (D) of FIG. 7 .

According to the above, the direction and size of the deviation of the measurement line due to the parallel movement with respect to the optical axis 10 can be read according to the following two elements. One of the elements is the signal intensity 42B when the signal intensity of the end region 40C is at 27A with respect to the measurement line, and the two elements are the signal width 42C when the signal width of the end region 40C is at 27A with respect to the measurement line. The size of the signal width 42D. When it is less than the signal intensity 42B, the measurement line can be read in the direction of 27B, and when it is greater than the signal intensity 42B, the measurement line can be read in the direction of 27C, and can be read according to the intensity difference from the signal intensity 42B. Take the offset width. Moreover, when it is larger than the signal width 42C and the signal width 42D, the measurement line can be read in the direction of 27B, and when it is smaller than the signal width 42C and the signal width 42D, the measurement line can be read in the direction of 27C, and The offset width is read based on the difference in intensity from the signal strength 42B. Further, the deviation of the measurement line with respect to the optical axis 10 due to the rotational movement can be read based on the width direction coordinate dependence of the signal intensity in the central region 40B. Further, it is also possible to read based on the difference in the respective signal widths of the end regions 40C. In this manner, the offset of the measurement line with respect to the optical axis 10 due to the parallel movement and the rotational movement can be read based on the photoelectric signal. Furthermore, in the second embodiment, since the measurement line is read There are two kinds of information on the offset with respect to the optical axis 10, so that the offset can be read with higher precision than the first embodiment.

In the case where the light shielding plate 50 as the third embodiment is used for the light shielding member 8, a change in the photoelectric signal caused by a change in the measurement line will be described with reference to FIG. The photoelectric signal in the case of the measurement line 27A is as shown in FIG. 9(A) as described above. At the instant when the measurement line is shifted from 27A to 27B, the signal intensity 54A of the central region 50B is reduced compared to the signal strength 52A, and the signal strength 54B of the end region 50C is maintained at the signal strength 52B. On the other hand, since the measurement line 27B traverses the slit 50D3 in addition to the slit 50D1 and the slit 50D2, the number of signals of the end portion is increased from two to three. Immediately thereafter, the light intensity adjusting unit 12 adjusts the illumination intensity of the illumination device 4 in a direction in which the signal intensity 54A becomes equal to the signal intensity 52A, and accordingly, the signal intensity 54B becomes smaller than the signal intensity 52B. . As a result, the photoelectric signal in the case of the measurement line 27B is as shown in FIG. 9(B).

The photoelectric signal in the case of the measurement line 27C is changed completely opposite to the measurement line 27B, and the illumination intensity of the illumination device 4 is adjusted in a weakened direction so that the signal intensity 56A of the central region 50B becomes equal to the signal intensity 52A. Corresponding to this, the signal intensity 56B of the end region 50C becomes larger than the signal strength 52B. On the other hand, since the measurement line 27C traverses only the slit 50D1 and does not traverse 50D2, the number of signals of the end portion is reduced from two to one. As a result, the photoelectric signal in the case of the measurement line 27C is as shown in FIG. 9(C).

The photoelectric signal at the time of the measurement line 27D generates a width direction coordinate dependency in the signal intensity 58A of the central region 50B. Moreover, for the signal strength 58A, if the average value of the width direction coordinates is taken, it becomes equal to the signal strength 52A, and thus The illumination intensity of the illumination device 4 is not particularly adjusted. Therefore, the signal strength 58B of the end region 50C does not change from the signal strength 52B. On the other hand, since the measurement line 27D traverses the slit 50D1 only on one side of the end portion 50C and does not traverse 50D2, the number of signals of the end portion is reduced from two to one. Since the measurement line 27D traverses 50D3 in addition to the slit 50D1 and the slit 50D2 on the other side of the end portion 50C, the number of signals of the end portion is increased from 2 to 3. That is, when the measurement line is shifted with respect to the optical axis due to the rotational movement, the number of the respective signals in the end portion 50C is different. As a result, the photoelectric signal in the case of the measurement line 27D is as shown in (D) of FIG.

According to the above, the direction and size of the deviation of the measurement line due to the parallel movement with respect to the optical axis can be read according to the following two elements. One of the elements is the magnitude of the signal intensity 52B when the signal intensity of the end region 50C is at 27A with respect to the measurement line, and the two elements are the number of signals at the end region 50C relative to the measurement line at 27A. The increase or decrease of the number. When it is less than the signal intensity 52B, the measurement line can be read in the direction of 27B, and when it is greater than the signal intensity 52B, the measurement line can be read in the direction of 27C, and can be read according to the intensity difference from the signal strength 52B. Offset width. Moreover, when the number of signals increases, the measurement line can be read in the direction of 27B, and when the number of signals decreases, the direction of the measurement line can be read in the direction of 27C, and the number of signals can be read according to the number of signals. The difference reads the offset width. Further, the deviation of the measurement line with respect to the optical axis 10 due to the rotational movement can be read based on the width direction coordinate dependence of the signal intensity in the central region 50B. Further, it is also possible to read based on the difference in the number of signals of the end regions 50C. In this manner, the offset of the measurement line with respect to the optical axis 10 due to the parallel movement and the rotational movement can be read based on the photoelectric signal. In the third embodiment, as in the second embodiment, Since there are two kinds of information that can read the deviation of the measurement line from the optical axis, the offset can be read with higher accuracy than the first embodiment.

A defect inspection device 60 according to an embodiment of the present invention will be described with reference to Fig. 10 . The defect inspection device 60 is a first modification of the defect inspection device 2. In addition to the configuration of the defect inspection device 2, the defect inspection device 60 is provided with a refractive index and a thickness between the subject 3 and the line sensor camera 6 so as to cover the entire width direction of the subject 3. A uniform transparent member 62. The transparent member 62 is rotatably provided, and as shown in FIG. 10, the transparent member 62 functions as an optical axis refraction mechanism that refracts the optical axis 10 by controlling the rotation angle thereof. In FIG. 10, members having the same functions as those of the defect inspection device 2 are denoted by the same reference numerals as those in FIG. 1, and description thereof will be omitted.

The example shown in FIG. 10 is an example in which it is not necessary to make the light shielding member 8 and the light shielding plate 30, the light shielding plate 40, and the light shielding plate as described in the defect inspection device 2 with respect to the displacement caused by the parallel movement of the optical axis surface. The 50 moves in parallel with respect to the optical axis plane, and the optical axis 10 is moved in parallel by the rotation of the transparent member 62 to perform adjustment. In this case, the position adjustment of the light shielding member 8 and the light shielding plate 30, the light shielding plate 40, and the light shielding plate 50 is only the movement corresponding to the offset by the rotational movement.

A defect inspection device 70 according to an embodiment of the present invention will be described with reference to Figs. 11 and 12 . The defect inspection device 70 is a second modification of the defect inspection device 2. As shown in FIG. 11, the defect inspection device 70 is provided with a concave cylindrical lens 72 in addition to the configuration of the defect inspection device 2. The concave lenticular lenses 72 are respectively provided on the optical path between the subject 3 and the light shielding member 8 that is irradiated to the end portion region of the light shielding member 8 and detected as the end light. In FIG. 11 and FIG. 12, members having the same functions as those of the defect inspection device 2 are denoted by the same reference numerals as those in FIG. Bright.

As shown in FIG. 12, the concave cylindrical lens 72 has a function of shifting the optical axis to spatially magnify when an optical axis shift occurs. Thereby, the optical axis shift amount can be detected with higher precision, thereby maintaining high sensitivity to fine defects. Further, the first modification and the second modification may be used in combination.

Further, in the embodiment of the present invention, in the above-described embodiment, a method and an apparatus for inspecting a defect such as a surface thereof while moving the film as a transparent film having a mesh shape are performed. Description. However, the invention is not limited thereto. For example, a method of detecting defects such as a surface thereof while moving a transparent glass plate and an apparatus thereof are also within the scope of the invention. Moreover, in the case of inspecting a very thick and transparent glass block for a sink or a submarine of an aquarium, the defect inspection device is designed to be movable in consideration of its large mass, and the defect inspection device is moved while moving. Methods of inspecting defects are also within the scope of the invention.

Further, in the embodiment of the present invention, it is possible to change the passage of light emitted from the illumination device by moving the light shielding plate and the optical axis in accordance with the needs of the user who is more likely to check the type of defect or the like. It is also within the scope of the invention to appropriately design changes in the manner of the ratio. Further, in the embodiment of the present invention, the focus of the line sensor camera 6 is aligned with the surface of the subject 3, but it is not limited thereto. For example, even if the focus is aligned with the edge 8A of the light shielding member 8, an equivalent inspection can be performed. Further, the alignment position of the focus may be the vicinity of the surface of the subject 3 and the edge 8A, and in actual use, even if it is aligned between the subject 3 and the edge 8A, the same inspection can be performed.

Further, in the embodiment of the present invention, the subject 3 is irradiated with light from the illumination device 4 via the light shielding member 8, and is received by the line sensor camera 6 The inspection light of the sample 3 and the end light passing through the width of the subject 3 are light. However, it is also within the scope of the present invention to change the design in such a manner that when the subject 3 has strong reflectivity, the reflected light is used as the inspection light instead of the transmitted light, in the width of the subject. A mirror is placed outside, and the reflected light from the total reflection mirror is taken as end light and received by the line sensor camera 6.

Further, in the above-described embodiment, the moving direction of the subject 3 is perpendicular to the longitudinal direction of the light-emitting surface 4A of the illumination device 4, and the moving direction of the subject 3 is perpendicular to the angle of the edge 8A of the light-shielding member 8. Situation, but not limited to this. For example, the case where the angles are predetermined angles other than 90 degrees such as 60 degrees or 45 degrees is also within the scope of the invention.

Further, in the embodiment of the present invention, the case where only one line sensor camera 6 is provided has been described. However, the present invention is not limited thereto, and the case where a plurality of cameras are arranged in the measurement width direction is also within the scope of the present invention. . That is, the line sensor camera in the specification of the present application and the patent application of the present application includes a case where a plurality of cameras are arranged in the measurement width direction.

2‧‧‧ Defect inspection device

3‧‧‧The subject

4‧‧‧Lighting device

4A‧‧‧Lighting surface

6‧‧‧ line sensor camera

8‧‧‧ shading members

8A‧‧‧ edge

11‧‧‧System Controller

12‧‧‧Light intensity adjustment department

14‧‧‧ Camera Action Department

16‧‧‧Signal Processing Department

18‧‧‧Defect Determination Department

19‧‧‧Defect Display Department

21‧‧ ‧ visor position detection department

22‧‧‧Warning Department

23‧‧ ‧ visor position adjustment department

25‧‧ Record Department

X‧‧‧ moving direction

Claims (8)

A defect inspection method comprising the steps of: continuously moving a transparent mesh or sheet-like object; and irradiating light from a side of the subject in continuous movement from a light-emitting surface of the illumination device, wherein the illumination device The light-emitting surface has a rectangular shape in which the long side is longer than the width of the subject, and the longitudinal direction of the light-emitting surface is disposed at a predetermined angle in a moving direction of the subject; and the light-shielding plate is formed on the light-shielding plate a state in which the edge is positioned in alignment with the optical axis of the line sensor camera, and is disposed between the light emitting surface and the object, and the light shielding plate includes a central region and an end region, wherein the central region is The light-emitting surface is entirely covered in the width direction of the subject, and is partially covered by the edge of the linear light-shielding plate that intersects the moving direction at a predetermined angle in the moving direction of the subject. In the light-emitting surface, the end portion region is formed in a light-shielding region shape that entirely covers the end portion of the light-emitting surface in the moving direction of the subject a through hole having a predetermined pattern; the line sensor of the line sensor camera receives the inspection light transmitted through the object and the light emitting surface end from the width of the object The end light of the portion, the line sensor camera is disposed to face the other side of the subject, and the arrangement direction of the pixels of the line sensor is arranged to be parallel to the longitudinal direction of the light emitting surface And evaluating the presence or absence of the defect based on the photoelectric signal of the central region obtained from the line sensor camera, and evaluating the visor relative to the line sensor camera based on the photoelectric signal of the end region Relative position. The defect inspection method described in claim 1 of the patent application, wherein Whether the photoelectric signal of the central region and the photoelectric signal of the end region are opposite to the moving direction of the object from a standard position with respect to the optical axis of the line sensor camera Move to evaluate the relative position above. The defect inspection method according to claim 1 or 2, wherein the alignment direction of the pixels of the line sensor camera and the above-mentioned light shielding plate are compared with each of the photoelectric signals of the end region The relative parallelism of the edges is used to evaluate the relative position described above. The defect inspection method according to claim 1 or 2, wherein the edge of the visor is not aligned with the optical axis of the line sensor camera based on the evaluation result of the relative position Alignment warning. The defect inspection method according to claim 1 or 2, wherein the adjustment unit is used to align the light shielding plate with the optical axis based on an evaluation result of the relative position, and the adjustment unit is configured to make the light shielding plate The edge is mechanically or optically adjusted in a manner that is aligned with the optical axis of the line sensor camera. The defect inspection method according to claim 5, wherein the adjustment unit that is optically adjusted has a refractive index and a uniform thickness transparent member that are provided so as to cover the entire width direction of the subject. Rotate. The defect inspection method according to the first or second aspect of the invention, wherein a concave cylindrical lens is provided on an optical path of the end light between the subject and the light shielding plate. The defect inspection method according to the first or second aspect of the invention, wherein the amount of light irradiated from the illumination device is adjusted such that the photoelectric signal intensity in the central region is substantially constant.