JP2003240725A - Apparatus and method for visual examinination - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus for visual examinination capable of clearly distinctly detecting whether a defect is a defect due to the same material as the stock or a defect due to a material different from the stock. <P>SOLUTION: A diffusing plate 18 is disposed so as to occupy at least a part of a cross section of a geometrical optical path between an illuminator 14 and a photographing unit 16. If an object 12 to be examined does not have the defect and is normal, a light attenuated by the plate 18 from the illuminator 14 arrive at the unit 16 through an examining point of the object 12, and hence the light is detected in the intensity attenuated by the plate 18 by the unit 16. Meanwhile, if the defect of the material different from the object 12 by mixing, for example, a foreign matter, exists at the examining point, the light is shielded by the foreign matter, and hence the defect is detected as a dark defect having a low light intensity. If the defect of the same material as that of the object 12 to be examined such as, for example, a ruggedness, a density unevenness or the like exists, the light detoured at the plate 18 is bent by the defect, and arrived at the unit 16, and hence the defect is detected as a bright defect having a strong light intensity. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a visual inspection apparatus and a visual inspection method for an inspection object, and more particularly to a visual inspection apparatus and a visual inspection method for distinguishing and detecting defects in the inspection object.

[0002]

2. Description of the Related Art Conventionally, this type of appearance inspection apparatus has an illuminating device for illuminating an object to be inspected and an image pickup camera for picking up an image of the object to be inspected.
Defects such as foreign matter, processing scratches, uneven density of materials, and bubbles are detected. When classifying these defects that should be detected by the visual inspection device, those that are the same as the material but have defects (typical examples: uneven scratches, uneven material density, etc.) and those that are different from the material have defects (typical example: Print pattern defects, foreign matter, etc.).

In a commonly used visual inspection device,
Regarding these two types of defects, two separate defects are detected by first inspecting the state of the material and finally inspecting foreign matter after product processing. .

However, such a two-time inspection requires a production lead time, requires two types of inspection devices, and increases the cost of the inspection device. Therefore, one appearance inspection causes two types of defects. There is a strong demand to be able to detect both simultaneously.

For this reason, an inspection apparatus having an illuminating device using a slit and an illuminating device using a light shielding plate has been developed. For example, in the one disclosed in Japanese Patent Laid-Open No. 11-14326, a slit is provided between the illuminating device and the material to be inspected, and the material to be inspected is illuminated with only light rays passing through the slit in a certain direction. There is. When defects such as gel defects due to uneven material density and fish eye defects due to foreign matter are present in the material to be inspected, light rays are bent due to the lens effect of these defects, and the resulting turbulence is imaged with a camera and detected as a defect. It is a thing.

[0006]

However, in the conventional device as described in the above publication, even if two kinds of defects can be detected at the same time, at best, they are simply detected as defects. Therefore, there is a problem that it cannot be distinguished whether the defect is due to the same material as the material or the defect due to a material different from the material.

The present invention has been made in view of the above problems, and an appearance inspection capable of simultaneously distinctly detecting whether it is a defect due to the same material as the material or a defect due to a material different from the material. It is an object of the present invention to provide an apparatus and a visual inspection method.

[0008]

In order to achieve the above object, the invention according to claim 1 is an illuminating device for illuminating an object to be inspected, and an imaging device for imaging the object to be inspected illuminated by the illuminating device. And a visual inspection device for inspecting the external appearance of an object to be inspected by processing an inspection image obtained from the output of the imaging device, wherein at least a part of a cross section of a geometrical optical path between the illumination device and the imaging device. The attenuator is disposed so as to occupy the light, and both the light attenuated by the attenuator from the lighting device and the light that has passed around the attenuator from the lighting device irradiate the object to be inspected and the object to be inspected. An illumination device so that only the light attenuated by the attenuator passes through the inspection point and reaches the imaging device when the inspection point of the object is not defective.
An attenuator and an imaging device are arranged.

When the inspection object has no defects and is normal, the light attenuated by the attenuator from the illuminating device passes through the inspection point of the inspection object and reaches the imaging device. The intensity attenuated by the attenuator is detected. On the other hand, if there are defects of a material different from that of the object to be inspected, such as foreign matter mixed, at the inspection point, the foreign substances block the light and are detected as dark defects with low light intensity. . Further, for example, when there are defects of the same material as the material to be inspected, such as unevenness and uneven density, the light that has passed around the attenuator is bent by the defects and reaches the imaging device. It is detected as a bright defect with high light intensity.

In this way, the defects can be distinguished and detected at the same time as a bright defect and a dark defect according to the type of defect. Since it is not necessary to perform the inspection twice, the lead time can be shortened and the inspection can be performed with one inspection device.
The cost of the device can also be reduced. As the attenuator, a diffusing plate, a reflecting plate, or the inspected object itself other than the inspection point can be used.

According to a second aspect of the present invention, the attenuating member according to the first aspect is arranged so as to be movable relative to an inspection point of an illumination device and an object to be inspected. It is characterized in that the incident angle of the light that has entered the attenuator with respect to the inspection point of the inspection object can be adjusted. By moving the attenuator relatively with respect to the inspection point of the illumination device and the inspection object, the incident angle of the light from the illumination device that goes around the attenuation body with respect to the inspection point of the inspection object is changed. be able to. When the incident angle changes, the detection sensitivity changes depending on the shape of the defect, which is a bright defect, so that the detection sensitivity can have shape selectivity. Therefore, it becomes possible to identify and detect only a defect having a predetermined shape, and thus a defect caused by a predetermined cause.

According to a third aspect of the present invention, the illuminating device according to the first aspect is arranged so as to be movable relative to an inspection point of an attenuator and an object to be inspected, whereby the illuminating device can detect the illuminating device. It is characterized in that the incident angle of the light, which has entered the attenuator, with respect to the inspection point of the inspection object can be adjusted. By moving the illuminating device relative to the inspection point of the attenuator and the object to be inspected, the incident angle of the light from the illuminating device that has entered the attenuator to the inspection point of the object to be inspected is changed. be able to. When the incident angle changes, the detection sensitivity changes depending on the shape of the defect, which is a bright defect, so that the detection sensitivity can have shape selectivity. Therefore, it becomes possible to identify and detect only a defect having a predetermined shape, and thus a defect caused by a predetermined cause.

According to a fourth aspect of the present invention, the damping body according to the first aspect is configured to be replaceable, whereby the damping rate of the damping body can be adjusted. By exchanging the damping body, the damping rate of the damping body can be changed. When the attenuation rate changes, the difference in light intensity between the case where there is no defect and the case where there is a dark defect is changed, so that the detection sensitivity can be changed. Therefore,
With the same threshold, the intensity range of the defect to be detected as a defect can be changed.

According to a fifth aspect of the present invention, the attenuator according to the first aspect is configured to be replaceable, whereby the spectral attenuation factor of the attenuator can be adjusted. By exchanging the attenuator, the spectral attenuation factor of the attenuator can be changed. When the spectral attenuation factor changes, the detection sensitivity changes depending on the color of the defect that is a dark defect, so that it becomes possible to identify and detect only the defect of the desired color.

According to a sixth aspect of the present invention, there is provided an appearance inspection method for inspecting an appearance of an object to be inspected by imaging an illuminated inspection point of the object to be inspected, generating an inspection image and processing the image. Attenuating at least a part of a ray bundle passing through a geometrical optical path between a point and the light source so that both the attenuated light and the unattenuated light illuminate an object to be inspected, When there is no defect in the inspection point of the inspection object, the geometrical arrangement of the light source, the inspection point, and the imaging point is set so as to capture an image of the inspection point irradiated by only the attenuated light. And When the inspection object has no defect and is normal, the light attenuated by the attenuator from the light source passes through the inspection point of the inspection object to be imaged, and the inspection image has the intensity attenuated by the attenuator. . On the other hand, if there is a defect of a material different from the material of the object to be inspected, such as foreign matter mixed, at the inspection point, the light is blocked by the foreign material, so it is detected as a dark defect with low light intensity. . Further, for example, when there is a defect of the same material as the material to be inspected such as unevenness or uneven density, the unattenuated light is bent by the defect and reaches the imaging device, so that the light with a strong light intensity is emitted. Detected as a defect.

In this way, it is possible to simultaneously distinguish and detect a bright defect and a dark defect according to the type of defect. Since it is not necessary to perform the inspection twice, the lead time can be shortened,
The cost for inspection can also be reduced.

Further, the geometrical arrangement of the light source, the inspection point and the imaging point can be changed to adjust the incident angle of the attenuated light to the inspection point of the object to be inspected or to attenuate the attenuated light. The sensitivity can be adjusted according to the shape, size, type, etc. of the defect by adjusting the rate or the spectral attenuation factor, and only the desired defect among the bright and dark defects can be identified and detected. Will be able to.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. The embodiment is not limited to this.

(First Embodiment) FIG. 1 is a schematic perspective view of an appearance inspection apparatus of the present invention. In the figure, the appearance inspection apparatus 10 targets an inspection object 12 made of a transparent sheet material as an example, and an illumination device 1 such as a fluorescent lamp is provided on one side of the inspection object 12 conveyed by a roller R and traveling.
4 is provided, and an image pickup device 16 such as a line CCD camera is provided on the other side to form a transmission type visual inspection device. In this example, the width is 3 in accordance with the width of the inspection object 12.
Although the imaging device 16 including one CCD camera is provided, the invention is not limited to this. The focus of the image pickup device 16 is aligned with the inspection point of the inspection object 12.

As shown in FIG. 2, the illuminating device 14 and the image pickup device 16 are opposed to each other with the object to be inspected 12 sandwiched therebetween, and are placed between the geometrical optical paths connecting the illuminating device 14 and the image pickup device 16. Light emitted from the illumination device 14 on which the inspection object 12 is arranged passes through the inspection point of the inspection object 12 and reaches the imaging device 16. Then, in the geometrical optical path connecting the illuminating device 14 and the imaging device 16, the attenuation is performed so as to cover a part of the cross section of the geometrical optical path between the inspection point of the inspection object 12 and the illuminating device 14. A diffuser plate 18, which is a body, is arranged. Almost all of the light beam bundles emitted from the illumination device 14 and passing through the geometrical optical path connecting the illumination device 14 and the image pickup device 16 are diffuser plates 1.
The light intensity diffused and attenuated by 8 and imaged by the imaging device 16 is set to an intermediate value in a normal state.

Reference numeral 22 is an encoder unit for detecting the traveling position of the inspection object 12.

Imaging device 16 and encoder unit 22
Is sent to the image processing device 20, where an inspection image is generated in the image processing device 20 and image processing for defect detection is performed.

In the appearance inspection apparatus configured as described above, when the object to be inspected 12 has no defect and is in a normal state, as shown in FIG.
The image pickup device 16 is transmitted through the diffusion plate 18 and the inspection object 12.
The light intensity that reaches the point and is imaged by the imaging device 16 becomes an intermediate value as described above.

On the other hand, as shown in FIG. 4, when the object to be inspected 12 has a defect such as inclusion of foreign matter, the diffused light passing through the diffusion plate 18 is blocked by the foreign matter. Therefore, the light intensity imaged by the imaging device 16 is weakened only in the portion corresponding to the foreign matter, and can be detected as a dark defect.

On the other hand, if there are defects such as unevenness and uneven density, the light is bent. Therefore, as shown in FIG. 5, the direct light emitted from the illumination device 14 and circling around the diffuser plate 18 is bent by such a defect, and the imaging device 1
Reach 6. Therefore, the light intensity imaged by the image pickup device 16 is strong because it is the direct light that does not pass through the diffusion plate 18, and can be detected as a bright defect.

The output from the image pickup device 16 is transmitted to the image processing device 20, where an inspection image is generated and processed. In the image processing device 20, the upper limit threshold T _up and the lower limit threshold T _down are set. When the light transmitted through the diffusion plate 18 passes through the defect-free inspection object 12, the density of the pixel is set in advance between the upper threshold T _up and the lower threshold T _down so that the upper threshold T _up , The lower limit threshold T _down is set. In the image processing apparatus 20, when the pixel density is higher than the upper threshold T _up , it is determined as a bright defect, and when the pixel density is lower than the lower threshold T _down , it is determined as a dark defect. In this way, it is possible to distinguish and detect defects that are the same material as the material but have defects as bright defects, and those that have different materials as defects as dark defects, and feed back the results to the production process. You will be able to. In this embodiment, the imaging device 1
When the light intensity reaches 6, the light intensity is clearly distinguished, so that the S / N ratio can be increased, and the subsequent processing of the image processing device 20 is also simplified.

(Second Embodiment) FIGS. 6 to 8 show an example in which the object to be inspected is non-transparent, and an example of a reflection type inspection apparatus. In this case, the illumination device 14 is disposed on one side of the inspection object 12, the imaging device 16 is disposed on the same side as the illumination device 14, and the imaging device 16 is the inspection device 1
It is arranged on the side opposite to the lighting device 14 with respect to the normal line passing through the two inspection points. The object to be inspected 12 is arranged in a geometrical optical path connecting the illuminating device 14 and the imaging device 16, and the illuminating device 14
The light emitted from the light source reflects the inspection point of the inspection object 12 and reaches the imaging device 16. The lighting device 14 and the imaging device 1
In the geometrical optical path connecting 6 and 6, a diffusing plate 18 as an attenuator is arranged so as to cover a part of the cross section of the geometrical optical path between the inspection point of the inspection object 12 and the illuminating device 14. To be done.

In FIG. 6, FIG. 6 shows the case where the inspection object 12 has no defect, FIG. 7 shows the case where foreign matter is mixed in the inspection object 12, and FIG. 8 shows the case where the inspection object 12 has irregularities. Respectively. Also in this embodiment, the same operation and effect as in the first embodiment can be obtained, and in the case of FIG. 7, it is detected as a dark defect, and in the case of FIG. 8, it is detected as a bright defect.

(Third Embodiment) FIG. 9 is an example of a transmission type in which the illumination device 14 is composed of a plurality of illumination devices 14-1, 14-2, 14-3. The illuminating device 14-1 is the same as the illuminating device 14 in FIG. 3, and is arranged on the side opposite to the imaging device 16 with respect to the inspection object 12. On the other hand, the illumination devices 14-2 and 14-3 are arranged on the same side as the imaging device 16 with respect to the inspection object 12.

Further, a reflector 18-1 which is an attenuator is arranged in front of the illuminator 14-1, and the reflector 18-1.
In the geometrical optical path connecting the illumination devices 14-1, 14-2, 14-3 and the imaging device 16 to the inspection point of the inspection object 12 and the illumination devices 14-1, 14-2, 14-3. It is arranged so as to cover a part of the cross section of the geometrical optical path between.
Most of the bundle of rays that exits the illuminating device 14-1 and passes through the geometrical optical path connecting the illuminating device 14-1 and the imaging device 16 is shielded by the reflector 18.

When the inspection object 12 is normal, the illuminating device 14
-2, the light from 14-3 is transmitted through the inspection object 12,
The light is scattered by the reflection plate 18-1, passes through the inspection point of the inspection object 12 again, and reaches the imaging device 16. Since the object to be inspected is transmitted twice and scattered by the reflection plate 18-1, attenuation occurs each time the light is transmitted or scattered, so that the light intensity reaching the imaging device 16 has an intermediate value. Similar to the previous embodiment, when a foreign matter or the like is mixed in the inspection object 12, it does not reach the imaging device 16, and is detected as a dark defect. When unevenness or the like is generated on the inspection object 12, the light that has passed around the reflector 18-1 from the illumination device 14-1 is refracted by the unevenness or the like and reaches the imaging device 16. In this case, since the object 12 to be inspected is transmitted only once, the light intensity reaching the image pickup device 16 is strong and detected as a bright defect. However, in this embodiment, instead of the reflection plate 18-1, the diffusion plate 18 can be used as in the first embodiment.

(Fourth Embodiment) FIG. 10 shows a lighting device 14
Is an example of a reflection type including a plurality of lighting devices 14-1, 14-2, 14-3. The lighting device 14-1 is shown in FIG.
The illumination device 14 is the same as the illumination device 14 of FIG. 1 and is arranged on the same side as the imaging device 16 with respect to the inspection object 12 and on the opposite side of the imaging device 16 with respect to the normal line passing through the inspection point of the inspection object 12. On the other hand, the illumination devices 14-2 and 14-3 have the
It is arranged on the same side as the image pickup device 16 with respect to 2.

Further, a reflector 18-1 which is an attenuator is arranged in front of the illuminating device 14-1, and the reflector 18-1 is provided.
In the geometrical optical path connecting the illumination devices 14-1, 14-2, 14-3 and the imaging device 16 to the inspection point of the inspection object 12 and the illumination devices 14-1, 14-2, 14-3. It is arranged so as to cover a part of the cross section of the geometrical optical path between.
Most of the bundle of rays that exits the illuminating device 14-1 and passes through the geometrical optical path connecting the illuminating device 14-1 and the imaging device 16 is shielded by the reflector 18.

When the inspection object 12 is normal, the illuminating device 14
The light from -2 and 14-3 reflects the object to be inspected 12, is scattered by the reflection plate 18-1, reflects the object to be inspected 12 again, and reaches the imaging device 16. The object to be inspected is reflected twice and scattered by the reflection plate 18-1, and attenuation occurs each time the light is transmitted or scattered. Therefore, the light intensity reaching the image pickup device 16 has an intermediate value. Similar to the previous embodiment, when foreign matter or the like is mixed in the inspection object 12, the imaging device 1
Since 6 is not reached, it is detected as a dark defect. When unevenness or the like is generated on the inspection object 12, the illumination device 14
The light that has passed around the reflection plate 18-1 from −1 is refracted by the unevenness and reaches the imaging device 16. In this case, since the object to be inspected 12 is reflected only once, the light intensity reaching the image pickup device 16 is high and detected as a bright defect. However, in this embodiment, instead of the reflection plate 18-1, the diffusion plate 18 can be used as in the first embodiment.

(Fifth Embodiment) As described above, according to the above-described embodiment, different kinds of defects can be detected separately as a dark defect and a bright defect. However, there is a case where it is desired to further distinguish the defect and feed back the result to the production process. For example, a bright defect is a defect of the same material, but if you want to detect bright defects that are three-dimensionally included in the material as defect shapes, you do not want to detect all of them as defects, but a certain shape. Sometimes you want to selectively detect. More specifically, when the material of the object to be inspected is glass, bubbles or micro cracks may occur in the material, which may cause a clear defect.
Bubbles and microcracks have different shapes, and the bubbles are relatively round and the microcracks are relatively elongated. Therefore, if the detection sensitivity can be made to have shape selectivity, such a difference in shape can be identified.

FIG. 11 is a principle diagram for providing shape selectivity. When defects of various shapes 1 to 3 shown in FIG. 11A are present in the inspected object 12, the inspected object 12 of the light circulated from the illuminating device 14 without passing through the diffusion plate 18.
When the angle of incidence with respect to the inspection point is small, the amount of light from the defect that is relatively long in the vertical direction increases, so the order of the light intensities detected by the imaging device 16 is >>. On the other hand, as shown in FIG. 11B, when the incident angle of the light circling from the illumination device 14 without passing through the diffusion plate 18 with respect to the inspection point of the inspection object 12 is large, the order is large. The order of the light intensities detected by the imaging device 16 is>
>. Therefore, regarding the bright defect, for example, when it is desired to extract only the defect as the defect, the incident angle of the light circling from the illumination device 14 without passing through the diffuser plate 18 to the inspected object 12 is increased, and only the defect is detected. The upper limit threshold in the image processing device 20 may be appropriately adjusted so as to be detected. On the contrary, if only one of them is to be detected as a defect, the incident angle may be made small.

An example of a transmission type device for realizing this principle is shown in FIGS. In the device shown in FIG. 12, the diffuser plate 18 is arranged so as to be movable with respect to the lighting device 14 by a hydraulic, pneumatic, electric or manual drive source 24. The diffusion plate 18 moves in the transverse direction with respect to the inspection point of the inspection object 12 (that is, the imaging point where the imaging device 16 is in focus). With the device shown in FIG.
The diffusing plate 18 is movably arranged with respect to the lighting device 14 by a hydraulic, pneumatic, electric, or manual drive source 24, and the moving direction of the diffusing plate 18 is moved toward or away from the inspection point of the inspection object 12. It is the direction. Alternatively, FIG.
In the device shown in FIG. 1, the lighting device 14 is arranged so as to be movable with respect to the diffusion plate 18 by a hydraulic, pneumatic, electric, or manual drive source 24. To move in the transverse direction and / or the approaching / separating direction. In addition, in the device shown in FIG.
8 is a hydraulic, pneumatic or electric or manual drive source 2
4 is arranged rotatably with respect to the illuminating device 14, and the diffusion plate 18 rotates in the direction of contact and separation with respect to the inspection point of the inspection object 12.

16 to 19 show a reflection type device for realizing this principle. In the device shown in FIG. 16, the diffuser plate 18 is arranged so as to be movable with respect to the lighting device 14 by a hydraulic, pneumatic, electric, or manual drive source 24. The diffusion plate 18 moves in the transverse direction with respect to the inspection point of the inspection object 12. In the device shown in FIG. 17, the diffusion plate 18 is movably arranged with respect to the illumination device 14 by a hydraulic, pneumatic, electric, or manual drive source 24, and the movement direction of the diffusion plate 18 is set to the inspection object. The direction of contact and separation is the 12 inspection points. Alternatively, FIG.
In the device shown in FIG. 1, the lighting device 14 is arranged so as to be movable with respect to the diffusion plate 18 by a hydraulic, pneumatic, electric, or manual drive source 24. To move in the transverse direction and / or the approaching / separating direction. In addition, in the device shown in FIG.
8 is a hydraulic, pneumatic or electric or manual drive source 2
4 is arranged rotatably with respect to the illuminating device 14, and the diffusion plate 18 rotates in the direction of contact and separation with respect to the inspection point of the inspection object 12.

12 to 15 and 16 to 19 described above.
In the device of FIG.
From the illuminating device 14 by moving the illuminating device 14 relative to the inspection point and the illuminating device 14 of FIG. It is possible to change the incident angle of the light reaching the inspection point of the inspection object 12 around the plate 18 with respect to the inspection object 12. Therefore, it becomes possible to adjust the incident angle according to the case where it is particularly desired to detect the defect in the principle diagram (FIG. 11) or the case where the defect is desired to be detected.

(Sixth Embodiment) Next, also with respect to dark defects, it is possible to provide detection sensitivity with selectivity.
As mentioned above, the dark defect is a defect due to different materials,
By changing the thickness of the diffusion plate or the reflection plate 18, it is possible to change the transmittance or the reflectance and control the detection sensitivity of a different material which is a dark defect. For example, the detection sensitivity can be controlled to detect only defects having a predetermined size or more. Alternatively, by changing the color of the diffusing plate or the reflecting plate 18, the spectral transmittance or the spectral reflectance can be changed to control the detection sensitivity due to a different material which is a dark defect. For example, it is possible to detect only defects of a predetermined color.

Therefore, in order to realize this embodiment,
In the device shown in FIG. 2, FIG. 6, FIG. 9 or FIG. 10, the diffuser plate 18 or the reflector plate 18-1 may be replaceable.

(Other Embodiments) As shown in the above embodiments, the diffusion plate 18 or the reflection plate 18-1 is not limited to the one-slit type arranged on only one side of the illuminating device 14, and FIG. Also, as shown in FIG. 21, it may be a double slit type arranged on both sides, or may be a plurality of fine slit types.

Further, in the above embodiment, the image pickup device 16
The line sensor has been described above, but the present invention is not limited to this. As shown in FIG. 22, the imaging device 16
Can also be a two-dimensional camera. In this case, the field of view of the camera is two-dimensional, but the diffuser plate 18 or the reflector plate 18-1 similarly covers a part of the geometrical optical path connecting the illumination device 14 and the imaging device 16. Is placed.

Further, the inspection object 12 is not limited to the sheet-like material as shown in the figure, and may have an arbitrary shape, and the appearance inspection apparatus of the present invention is an inspection object having an arbitrary shape. It can be applied to 12 visual inspections.

[0045]

As described above, according to the present invention,
It is possible to distinguish defects as bright defects and dark defects according to the types of defects and detect them simultaneously. Since it is not necessary to perform the inspection twice, the lead time can be shortened and the cost of the inspection device can be reduced.

[Brief description of drawings]

FIG. 1 is a schematic perspective view of a transmission type visual inspection apparatus according to a first embodiment of the present invention.

FIG. 2 is a side view of the first embodiment.

FIG. 3A is a cross-sectional view showing the principle when the inspection object according to the first embodiment has no defect, and FIG. 3B is an image detected by the imaging device in that case.

FIG. 4A is a cross-sectional view showing the principle in the case where the inspection object of the first embodiment has a defect such as inclusion of foreign matter, and FIG. 4B is an image detected by the imaging device in that case.

FIG. 5A is a cross-sectional view showing the principle when the inspection object of the first embodiment has defects such as unevenness and uneven density;
(B) is a detected image by the imaging device in that case.

FIG. 6 is a cross-sectional view of a reflection type visual inspection device according to a second embodiment of the present invention, and is a diagram showing the principle when an inspection object has no defect.

FIG. 7 is a cross-sectional view showing the principle of the second embodiment when there is a defect such as foreign matter in the inspected object.

FIG. 8 is a cross-sectional view showing the principle when the inspection object of the second embodiment has defects such as unevenness and uneven density.

FIG. 9 is a sectional view of a reflection type visual inspection device according to a third embodiment of the present invention.

FIG. 10 is a sectional view of a reflection type visual inspection device according to a fourth embodiment of the present invention.

FIG. 11 is an explanatory sectional view showing the principle of the fifth embodiment of the present invention.

FIG. 12 is a sectional view of a transmission type visual inspection apparatus according to a fifth embodiment of the present invention.

FIG. 13 is a transmissive type FIG. 12 according to a fifth embodiment of the present invention.
3 is a cross-sectional view of a visual inspection device different from FIG.

FIG. 14 is a transmissive type FIG. 12 according to a fifth embodiment of the present invention.
FIG. 14 is a cross-sectional view of a visual inspection device different from that in FIG. 13.

FIG. 15 is a transmissive type view according to a fifth embodiment of the present invention.
It is sectional drawing of the visual inspection apparatus different from FIG.

FIG. 16 is a sectional view of a reflection type visual inspection device according to a fifth embodiment of the present invention.

FIG. 17 is a reflection type view according to a fifth embodiment of the present invention.
3 is a cross-sectional view of a visual inspection device different from FIG.

FIG. 18 is a reflection type view according to a fifth embodiment of the present invention.
18 is a cross-sectional view of an appearance inspection device different from that in FIG.

FIG. 19 is a reflection type view according to a fifth embodiment of the present invention.
It is sectional drawing of the visual inspection apparatus different from FIG.

FIG. 20 is a perspective view illustrating a lighting device and a diffusion plate or a reflection plate according to another embodiment of the present invention.

FIG. 21 is a perspective view showing a lighting device and a diffusion plate or a reflection plate according to another embodiment of the present invention.

FIG. 22 is a perspective view when the imaging device is a two-dimensional camera.

[Explanation of symbols]

10 Visual inspection device 12 Inspected 14 Lighting device 16 Imaging device 18 Diffuser (Attenuator) 18-1 Reflector (Attenuator)

Claims (6)

[Claims] 1. An inspecting device, comprising: an illuminating device for illuminating an inspecting object; and an imaging device for imaging the inspecting object illuminated by the illuminating device, and processing an inspection image obtained from an output of the imaging device. In the appearance inspection device for inspecting the appearance of, an attenuator is arranged so as to occupy at least a part of a cross section of a geometrical optical path between the illumination device and the imaging device, and When both the attenuated light and the light that has passed around the attenuator from the illumination device irradiate the object to be inspected, and there is no defect at the inspection point of the object to be inspected,
The visual inspection apparatus, wherein the illumination device, the attenuator, and the imaging device are arranged so that only the light attenuated by the attenuator passes through the inspection point and reaches the imaging device. 2. The attenuator is arranged so as to be movable relative to an inspection point of the illumination device and the inspection object, and thereby the inspection object of the light from the illumination device that goes around the attenuation body. 2. The appearance inspection apparatus according to claim 1, wherein the incident angle with respect to the inspection point is adjustable. 3. The aforesaid illumination device is arranged so as to be movable relative to the attenuator and the inspection point of the inspected object, so that the inspected object of the light from the illumination device that goes around the attenuator is inspected. 2. The appearance inspection apparatus according to claim 1, wherein the incident angle with respect to the inspection point is adjustable. 4. The appearance inspection apparatus according to claim 1, wherein the attenuator is configured to be replaceable, and thereby the attenuation rate of the attenuator can be adjusted. 5. The appearance inspection apparatus according to claim 1, wherein the attenuator is configured to be replaceable, and thereby the spectral attenuation factor of the attenuator can be adjusted. 6. A visual inspection method for inspecting the appearance of an inspected object by imaging an illuminated inspection point of the inspected object, generating and processing the inspection image, and a geometrical feature between a light source and the inspection point. At least a part of the light flux passing through the optical path is attenuated so that both the attenuated light and the non-attenuated light from the light source irradiate the inspection object, and the inspection point of the inspection object. If there is no defect, the appearance inspection method is characterized in that the geometrical arrangement of the light source, the inspection point, and the imaging point is set so that the inspection point illuminated by only the attenuated light is imaged.