JP2001033228A - Surface inspecting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a surface inspecting device capable of suppressing illuminance irregularities on an inspection surface caused by a material forming an inspection object and the shape of the inspection surface and capable of improving the recognition precision of detects existing on the inspection surface when the photographed image data are image-processed. SOLUTION: This surface inspecting device 1 makes a defect inspection for an O-ring 51 serving as an inspection object having a curved inspection surface. The surface inspecting device 1 is provided with a lighting system 31 serving as an illuminating means illuminating illumination light to the seal face 51a of the O-ring 51, a diffusing plate 2 transmitting and diffusing the illumination light, CCD cameras 21, 22, 23 serving as image pickup means photographing the seal face 51a of the O-ring 51, and an image processing device 41 extracting the defects existing on the seal face 51a based on the light receiving quantity of each picture element of image data photographed by the CCD cameras. The diffusing plate 2 has a shape for nearly unifying the illuminance distribution on the curved seal face 51a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface inspection apparatus for inspecting a defect such as a scratch present on an inspection object having an inspection surface having a curvature such as an O-ring sealing surface.

[0002]

2. Description of the Related Art For example, a sealing member such as an O-ring is
Before the product is shipped, it is necessary to inspect the sealing surface for defects such as scratches in order to exert the original function of the sealing member. Conventionally, the inspection of the seal surface of the O-ring has been performed by an inspection device as shown in FIG. FIG. 14A is a top view of the inspection apparatus, and FIG. 14B is a side view. In FIG. 14, an O-ring 101 is mounted on a rotation shaft 105a of a drive motor 105, and an image of the inspection surface 101a is taken on a side of the inspection surface 101a of the O-ring 101. For example, a CCD using a charge-coupled device is used. The camera 102 is arranged. Also, C
On both sides of the CD camera 102, illumination devices 103 for irradiating illumination light toward the inspection surface 101a of the O-ring 101 are arranged. Image data captured by the CCD camera 102 is input to the image processing device 106.

In the inspection apparatus having the above configuration, an image of the inspection surface 101 a of the O-ring 101 illuminated with illumination light from the illumination device 103 is captured by a CCD camera 102, and the image data is input to an image processing device 106. You. The image processing device 106 extracts a defect existing on the inspection surface 101a of the O-ring 101 based on the amount of received light of each pixel of the image data. For example, if there is a defect such as a deformation or a scratch on the inspection surface 101a, which is the seal surface of the O-ring 101, the brightness of the image in the defect area in the image data of the inspection surface 101a of the O-ring 101 is changed to another normal area. , The region having the different brightness is extracted as a defect.

[0004]

By the way, since rubber products such as the above-mentioned O-ring 101 generally contain a large amount of additives, their particles are not completely dispersed, and the surface has a light reflection characteristic of light. Not uniform. In addition, the surface is often rough even at a level where there is no problem in performance due to the influence of a molding die and raw materials. Further, micro-level dust that does not affect the performance but cannot be removed by blowing air or the like may adhere to the surface. Even if the inspection surface 101a of the O-ring 101 having such characteristics is directly irradiated with the illumination light, or if the illumination light is simply diffused by a flat diffusion plate, the reflection characteristics of the surface become non-uniform, Irradiation unevenness is likely to occur on the inspection surface 101a due to the influence of roughness of the surface, adhesion of micro-level dust, and the like. Difficult to identify. Further, the inspection surface 101a of the O-ring 101 is curved and not flat. Inspection surface 10 of O-ring 101
Recognizing a defect existing on the inspection surface 101a from the image is to capture the depth of the defect existing on the non-flat surface, which makes it more difficult to identify the defect existing on the inspection surface 101a.

SUMMARY OF THE INVENTION The present invention has been made in view of such a conventional problem, and has been developed in consideration of the surface characteristics of the surface to be inspected based on the material forming the object to be inspected and the shape of the surface to be inspected. Provided is a surface inspection apparatus capable of suppressing uneven illuminance and improving recognition accuracy of a defect such as a minute scratch existing on a surface to be inspected when performing image processing on image data of the surface to be inspected. The purpose is to:

[0006]

SUMMARY OF THE INVENTION The present invention relates to a surface inspection apparatus for inspecting a defect having a curved surface to be inspected, which irradiates illumination light toward the surface to be inspected. Lighting means to transmit illumination light from the lighting means,
And a diffusion plate for diffusing, imaging means for imaging the inspected surface of the inspected object, and a defect existing on the inspected surface based on an amount of light received by each pixel of the image data imaged by the imaging means. Image processing means for extracting, and the diffuser plate has a shape that makes the illuminance distribution on the curved inspection surface substantially uniform.

[0007] The diffusion plate has a curved portion curved in accordance with the curvature of the surface to be inspected.

[0008] The diffusion plate is provided with an opening for imaging the surface to be inspected by the imaging means.

The illuminating means has an opening for imaging the surface to be inspected in a central region, and is configured to irradiate an annular illumination light. The diffuser plate has a cylindrical light transmitting member. One end side is accommodated in the opening, and the annular end face on the other end side is arranged so as to surround the inspection surface to be imaged by the imaging means, and the illumination light incident on the side surface is And irradiates the surface to be inspected.

According to the present invention, when performing a defect inspection on an inspection object having a curved inspection surface, the illumination light from the irradiating means is diffused through the diffusion plate and irradiated on the inspection surface of the inspection object. At this time, the diffuser not only diffuses the illumination light but also diffuses the illumination light so that the illuminance distribution becomes substantially uniform in accordance with the curved surface to be inspected. In this way, by diffusing the illuminance distribution so as to be substantially uniform in accordance with the shape of the curved surface to be inspected, the curvature of the surface to be inspected, the non-uniformity of the reflection characteristics of the surface to be inspected, the rough surface, The effect of adhesion of dust at a micro level or the like is suppressed, and defects in images are easily identified.

[0011]

Embodiments of the present invention will be described below in detail with reference to the drawings. First Embodiment FIG. 1 is a configuration diagram showing a configuration of an embodiment of a surface inspection apparatus according to the present invention, and FIG. 2 is a top view of the surface inspection apparatus shown in FIG. Note that, for example, an O-ring W will be described as an object to be inspected by the surface inspection apparatus according to the present embodiment.

As shown in FIG. 1, a surface inspection apparatus 1 according to the present embodiment includes a driving device 10 provided on a base 5 for rotating a mounting shaft 11 and holding the driving shaft 10 at a predetermined position on the base 5. Diffused plate 2 and O-ring 51 mounted on mounting shaft 11
Three CCD cameras 21, 21, and 23 as imaging means for capturing an image of the surface of
An image processing device 41 is provided as image processing means for extracting a defect existing on the surface of the O-ring 51 based on the image data captured by the devices 21 and 23. Further, as shown in FIG. 2, on both sides of each of the CCD cameras 21, 21, and 23, an illumination device 31 as illumination means for irradiating illumination light toward the O-ring 51 is provided. Each illumination device 31 is arranged such that the optical axis of the illumination light to be irradiated intersects the sealing surface of the O-ring 51. As the light source of the illumination device 31, for example, a halogen lamp having a wavelength characteristic compatible with the CCD camera can be used.

Here, FIG. 3 shows the diffusion plate 2 and the O-ring 5.
FIG. 4 is an enlarged side view showing the periphery of FIG.
It is sectional drawing of the -A line direction. As shown in FIGS. 3 and 4, the O-ring 51 has a sealing surface 51a having a substantially circular cross section and curved in a convex shape, and is made of, for example, a black rubber material. The O-ring 51 has a mounting portion 11 whose inner peripheral portion is formed in a concave shape on the mounting shaft 11 of the driving device 10.
a. One end of the diffusion plate 2 is connected and held by a support member 6 fixed on a base 5, and an O-ring 5
1 has a curved portion 2a whose section is curved in an arc shape along the peripheral surface. As shown in FIG. 3, the curved portion 2a of the diffusion plate 2
Slit portion 3 opened substantially along the center of curved portion 2a
Having. The width of the slit 3 is determined by the CCD camera 2 that captures an image of the seal surface of the O-ring 51 through the slit 3
The setting is made according to the widths of the imaging areas 1, 22, and 23.

The diffusion plate 2 diffuses the illumination light L from the illumination device 31 as shown in FIG. The diffusion plate 2 is made of, for example, a material that transmits light, such as an acrylic resin, and may be, for example, one that has a large number of fine irregularities formed on the surface. Alternatively, a resin colored with a coloring material such as milky white may be used.

As shown in FIG. 1, the CCD camera 21
Are arranged so as to image the seal surface outside the O-ring 51, and are arranged so as to image the seal surface of the O-ring 51 through the slit portion 3 of the curved portion 2 a of the diffusion plate 2. The CCD cameras 22 and 23 are arranged symmetrically with respect to the CCD camera 21 at a position inclined at an angle θ, for example, 70 degrees, and are arranged in a slit portion of the curved portion 2 a of the diffusion plate 2 from an oblique direction of the sealing surface of the O-ring 51. 3 is arranged so as to image the seal surface of the O-ring 51. As the CCD cameras 21, 22, and 23, those generally used in the field of image processing are used. For example, a CCD camera having one million pixels is used. In addition, each C
The CD cameras 21, 22, and 23 and the illuminating devices 31 arranged on both sides of each CCD camera correspond to the optical axis of the illuminating device 31 arranged on both sides of each CCD camera and the optical axis of the CCD camera. It is a positional relationship to intersect.

The driving device 10 comprises, for example, a driving motor for rotating the mounting shaft 11 at a predetermined angle, and is imaged by each of the CCD cameras 21, 22 and 23 through the slit 3 of the curved portion 2a of the diffusion plate 2. O-ring 51
The O-ring 51 is sequentially rotated at a rotation angle corresponding to each inspection area, and finally rotated 360 degrees.

The image processing device 41 is composed of, for example, a personal computer,
The image data captured by 2 and 23 are input, respectively, and these image data are quantized, and predetermined image processing is performed on the image data quantized by necessary built-in software. The predetermined image processing in the image processing device 41 is performed, for example, by identifying a light and dark area in the image data based on the amount of light received by each pixel of the input image data, and detecting a scratch or the like existing on the sealing surface 51 a of the O-ring 51. Extract defects.

Next, an example of the operation of the surface inspection apparatus 1 having the above configuration will be described. First, an O-ring 51 as an object to be inspected is mounted on the mounting shaft 11. The O-ring 51 can be mounted on the mounting shaft 11 by, for example, an operator or by an automatic mounting device (not shown).

Next, illumination light is emitted from each illumination device 31 toward the O-ring 51. As shown in FIG. 4, the illumination light L emitted from each illumination device 31 enters the curved portion 2 a of the diffusion plate 2, is diffused, and is applied to the sealing surface of the O-ring 51. At this time, since the curved portion 2a of the diffusion plate 2 is curved along the curved sealing surface 51a of the O-ring 51, the illumination light incident on the curved portion 2a of the diffusion plate 2 It diffuses substantially uniformly to the surface 51a. Therefore, the curved sealing surface 51 of the O-ring 51
The illuminance distribution at a becomes substantially uniform. In particular, the curved portion 2a of the diffusion plate 2 in the present embodiment is curved along the curved sealing surface 51a of the O-ring 51,
Since the distance from each position of the curved sealing surface 51a to the curved portion 2a of the diffusion plate 2 is substantially uniform, the sealing surface 51a is more diffused than when the illumination light is simply diffused by the flat diffusion plate. The uniformity of the illuminance distribution is high.

In this state, each CCD camera 21,
22 and 23 image the sealing surface 51 a of the O-ring 51 through the slit 3 formed in the curved portion 2 a of the diffusion plate 2. Here, FIG. 5 shows an example of the surface inspection apparatus according to the present embodiment,
FIG. 6 is an example of an image of the seal surface of the ring 51, and FIG. 6 is an example of an image of the seal surface of the O-ring 51 directly irradiated with the illumination light without using the diffusion plate 2. As shown in FIG. 6, when the sealing surface 51 a of the O-ring 51 is directly irradiated with illumination light without using the diffusion plate 2, the image of the sealing surface 51 a includes the white shining defect K and the defect K in the same manner. There is an area G that glows white. The white shining region G is the sealing surface 51a.
Are curved, the O-ring 51 is a rubber product, the light reflection characteristics of the sealing surface 51a of the O-ring 51 are not uniform, the surface is rough at a level where there is no problem in the performance, and the micro level. It is generated by the influence of dust adhesion. When such an area G exists, a difference does not easily occur in the amount of light received by pixels corresponding to the area G and the defect K in the image data, and it is difficult to distinguish the defect K from the area G.

On the other hand, when the illuminating light is diffused using the diffusion plate 2 according to the present embodiment and is applied to the sealing surface 51a of the O-ring 51, the illuminance on the sealing surface 51a of the O-ring 51 is increased as described above. Since the distribution becomes substantially uniform, the curvature K of the sealing surface 51, the unevenness of the light reflection characteristics of the sealing surface 51a, the roughness of the surface, the influence of the adhesion of micro-level dust, and the like, and the difference between the defect K occur. As shown in FIG.
In the image data, there is a difference in brightness between the area G and the defect K. For example, the defect K is darker than the area G. That is, by making the illuminance distribution of the sealing surface 51a of the O-ring 51 uniform, the curvature of the sealing surface 51a,
1a, the reflection characteristics of the light are not uniform, the roughness of the surface, the attachment of micro-level dust, and the like may cause a difference in the amount of light received by the pixels corresponding to the region G and the defect K that glow white. it can.

Image data picked up by each of the CCD cameras 21, 22 and 23 is input to an image processing device 41, quantized, and subjected to predetermined image processing. For example, regions having different brightness are extracted by a predetermined image processing algorithm based on the amount of received light of each pixel of the image data input to the image processing device 41. In this embodiment,
In the image data input to the image processing device 41, the brightness of the region G and the defect K are different, so that the defect K can be easily identified in the image processing, and the shape of the defect K can be reliably extracted. Becomes

When the inspection of the inspection area within a predetermined range on the sealing surface 51a of the O-ring 51 is completed, the O-ring 51 is rotated by a predetermined angle by the driving device 10, and the same processing as above is performed again. The entire surface 51a is inspected for defects on the sealing surface 51a.

As described above, according to the surface inspection apparatus of the present embodiment, the illumination light from the illumination device 31 is transmitted by the diffusion plate 2 having the curved portion 2a curved along the sealing surface 51a of the O-ring 51. Since the irradiation is performed in a diffused manner, a uniform illuminance distribution can be obtained over a wide range of the inspection area of the seal surface 51a of the O-ring 51. Seal surface 5 of O-ring 51
By making the illuminance distribution of 1a uniform, the O-ring 5 in the image data obtained by imaging the sealing surface 51a of the O-ring 51 is obtained.
It is possible to easily identify a defect existing on the first sealing surface 51a, and it is possible to improve detection accuracy of a defect existing on the sealing surface 51a of the O-ring 51. Further, according to the surface inspection apparatus according to the present embodiment, the slit 3 is formed in the curved portion 2a curved along the seal surface 51a of the O-ring 51.
Is formed, a wide range of the sealing surface 51a can be inspected at the same time, and the inspection efficiency of the sealing surface 51a of the O-ring 51 can be improved. Further, according to the surface inspection device according to the present embodiment, when imaging the seal surface 51a of the O-ring 51 from a plurality of positions through the slit 3, the illuminance conditions are substantially the same for each region of the seal surface 51a.
The inspection accuracy based on the image data captured by each of the CCD cameras 21, 22, and 23 can be made uniform. Further, when imaging the seal surface 51a of the O-ring 51 from a plurality of positions through the slit 3, since the illuminance condition is substantially the same for each region of the seal surface 51a, each CCD camera 2
It is also easy to combine the image data of the images 1, 22, and 23.

Second Embodiment FIG. 7 is a configuration diagram showing the configuration of a second embodiment of the surface inspection apparatus according to the present invention. The surface inspection device 61 according to the present embodiment is fixed on a base 62 as shown in FIG.
Mounting shaft 6 on which seal member 81 as a test object is mounted
5, a driving device 64, a CCD camera 71 as an imaging unit supported by a support member 63 provided on the base 62, and fixed to the support member 63 and provided above the seal member 81. A ring illumination 67 as illumination means, a roll-type diffusion plate 66 provided above the seal member 81, a light source 70 of the ring illumination 67, and an image processing device 75 are provided.

Here, FIG. 8 shows a seal member 81 for a gas valve as an inspection object of the surface inspection apparatus 61 shown in FIG.
FIG. 3 is a cross-sectional view showing the structure of FIG. The seal member 81 is a disk-shaped member having a through hole 81b at the center, and has an annular seal surface 81a on one end surface side. Annular sealing surface 81a
For example, as shown in FIG. 9, the profile of the cross section is formed to be curved in a convex shape, and the sealing surface 81a comes into close contact with other members to perform a sealing function. Seal member 81
If a defect such as a scratch is present on the sealing surface 81a, the sealing surface 81a does not perform its original function. Therefore, the presence or absence of a defect is inspected by the surface inspection device 61 according to the present embodiment.

The ring illumination 67 is an annular body having an opening 67a in the center area thereof, and incorporates a bundle of optical fibers arranged in an annular shape (not shown). These optical fibers are led out from the side of the ring illumination 67 toward the light source. The light supplied from the light source 70 is emitted as annular illumination light downward from the lower surface 67b of the ring illumination 67 through an optical fiber arranged annularly inside the ring illumination 67. The ring illumination 67 is preferably arranged such that the center of the opening 67 a is located on the sealing surface 81 a of the sealing member 81. In addition, ring illumination 67
The diameter of the opening 67a is set sufficiently larger than the radial width of the sealing surface 81a. The light source 70 includes
For example, a halogen lamp compatible with the CCD camera 71 as an image pickup means with respect to wavelength characteristics can be used.

The roll diffusion plate 66 is a cylindrical body having an opening 66a at the center. Roll type diffuser 66
The center of the opening 66a is the opening 67 of the ring illumination 67.
The ring light 67 is disposed so as to substantially coincide with the center line of a, and a part on the upper end side is inserted into the opening 67 a of the ring illumination 67. Further, the roll-type diffusion plate 66 has an opening 66.
The center of “a” is disposed so as to be located substantially at the center of the seal surface 81 a of the seal member 81. Roll diffuser 6
6 guides the annular illumination light emitted from the ring illumination 67 toward the outer peripheral surface 66c from the lower end surface 66b to the sealing surface 81a of the sealing member 81 through the annular solid portion. At this time, the annular lower end surface 66 of the roll diffusion plate 66
The illumination light diffused from b is diffused in various directions. As a material for forming the roll-type diffusion plate 66, for example, a translucent acrylic resin colored milky white or the like can be used, and this material is formed into a cylindrical shape. In addition, the diameter of the roll-type diffusion plate 66 is set to a value that can ensure the visual field range of the CCD camera 71 and the inspection range of the seal surface 81a of the seal member 81.

The driving device 64 includes, for example, the sealing member 8
1 comprises a drive motor for rotating the mounting shaft 65 at a predetermined angle, and sequentially rotates the seal member 81 at a rotation angle corresponding to each inspection area of the seal surface 81a of the seal member 81 imaged by the CCD camera 71. The seal member 81 is finally rotated 360 degrees.

The CCD camera 71 is arranged so that the field of view faces the sealing surface 81a of the sealing member 81 through the opening 66a of the roll diffusion plate 66. CCD camera 7
For 1, a camera generally used in the field of image processing is used, for example, a 1 million pixel CCD camera is used.

The image processing device 75 is composed of, for example, a personal computer, receives image data picked up by the CCD camera 71, quantizes the image data, and quantizes the image data by necessary built-in software. The image data is subjected to predetermined image processing. The predetermined image processing in the image processing device 75 is performed, for example, by identifying a light and dark area in the image data based on the amount of received light of each pixel of the input image data,
The defect such as a scratch existing on the sealing surface 81a is extracted.

Next, an example of a procedure for inspecting the seal surface 81a of the seal member 81 by the surface inspection apparatus 61 having the above-described configuration will be described. First, the through-hole 81 b of the seal member 81 is mounted on the mounting shaft 65 of the driving device 64. Next, illumination light is emitted from the ring illumination 67. Part of the annular illumination light emitted from the ring illumination 67 enters, for example, the outer peripheral surface 66c of the roll diffuser 66, as shown in FIG. The annular illumination light incident on the outer peripheral surface 66c of the roll diffuser 66 is introduced into the roll diffuser 66 and diffuses from the lower end surface 66b of the roll diffuser 66. For example, as shown in FIG.
1a, an annular lower end surface 66b of the roll diffusion plate 66
, The inspection area includes the lower end face 66.
The diffused light scattered from b is applied. Therefore, the illuminance distribution in the inspection area of the seal surface 81a of the seal member 81 is substantially uniform even if the seal surface 81a is curved.

In this state, the sealing surface 8 of the sealing member 81 is
An image of the inspection area is captured by the CCD camera 71 provided above the inspection area 1a. Here, FIG. 12 is an example of an image of the sealing surface 81a of the sealing member 81 taken by the CCD camera 71 of the surface inspection device 61 according to the present embodiment, and FIG. It is an example of the image of the sealing surface 81a of the sealing member 81 to which the annular illumination light from the illumination 67 was directly irradiated.
As shown in FIGS. 12 and 13, when a defect J such as a scratch is present on the sealing surface 81a of the sealing member 81, the area where the defect J exists has a different brightness from other normal areas on the image data.

As can be seen from FIG.
When the illumination light is directly applied to the sealing surface 81a of the sealing member 81 without using the roll-type diffusion plate 66, in addition to the defect J, a striped bright and dark area caused by illuminance unevenness on the sealing surface 81a of the sealing member 81 is generated. appear. Such a striped bright and dark region caused by uneven illuminance on the seal surface 81a of the seal member 81 is, for example, curved when the seal surface 81a is formed or when the seal member 81 is formed of, for example, a rubber material. This is generated based on uneven illuminance of the seal surface 81a due to surface roughness or the like. For example, a stripe-like light and dark area is a defect J
, Or overlap with the defect J, it is difficult to specify the boundary of the shape of the defect J, and it is difficult to specify the shape of the defect J accurately.

On the other hand, as shown in FIG. 12, the annular illumination light from the ring illumination 67 is diffused by using the roll diffusion plate 66 according to the present embodiment, and the illuminance distribution of the sealing surface 81a of the curved sealing member 81 is distributed. Is made substantially uniform, it is difficult to generate a stripe-like bright and dark area due to uneven illuminance of the seal surface 81a of the seal member 81 described above. Therefore, it is easy to specify the boundary of the shape of the defect J, and the accuracy of specifying the shape of the defect J can be improved.

The image data picked up by the CCD camera 71 is input to an image processing device 75, quantized,
Predetermined image processing is performed. For example, the image processing device 7
A defective area is extracted by a predetermined image processing algorithm on the basis of the amount of light received by each pixel of the image data input to 5. Also, if it is determined that a defect exists,
By performing a tracking process for tracking the boundary of the shape of this defect,
Identify the shape of the defect. For this tracking processing, for example, a known tracking method such as graph tracking or local Huff tracking can be used. In the present embodiment, since the image data captured by the CCD camera 71 is unlikely to have a striped bright and dark area due to uneven illuminance due to the curvature and surface roughness of the sealing surface 81a of the sealing member 81, the above-described tracking is performed. During the processing, it is suppressed that the boundary of the shape of the defect is difficult to be specified by the stripe-like light and dark areas, and the shape of the defect can be specified more accurately.

When the inspection of the inspection area within a predetermined range of the seal surface 81a of the seal member 81 is completed, the seal member 81 is rotated by a predetermined angle by the driving device 64, and the same processing as above is performed again. A defect on the sealing surface 81a is inspected.

As described above, according to the present embodiment, like the sealing member 81 for a gas valve, the sealing surface 81 having a curved surface shape formed annularly on one end surface of a disk-shaped member.
a when the surface is inspected by image processing.
By diffusing the annular illumination light radiated to a by the roll-type diffusion plate 66, it is possible to make the illuminance distribution on the curved sealing surface 81a uniform. As a result, the sealing surface 81 captured by the CCD camera 71
In the image data a, it is possible to suppress the occurrence of bright and dark areas due to uneven illuminance due to the curvature of the seal surface 81a and the light reflection characteristics of the surface of the seal member 81. As a result, it is possible to detect a defect existing on the sealing surface 81a of the sealing member 81 and improve the accuracy of specifying the shape of the defect.

The present invention is not limited to the above embodiment. For example, in the above-described embodiment, the seal surface 51a of the O-ring 51 and the seal surface 81a of the seal member 81 have been described as the inspection surfaces of the inspection object. However, the present invention is not particularly limited thereto. The surface inspection apparatus of the present invention can be applied to an inspection object having an inspection surface. Further, in the above-described embodiment, as an example of a material to be inspected, a black rubber material has been described. However, when the surface inspection apparatus of the present invention is applied to an inspected object made of such a material, It is particularly effective, but can be applied to other materials.

[0040]

According to the surface inspection apparatus of the present invention, unevenness in illuminance on the surface to be inspected due to the material forming the object to be inspected and the shape of the surface to be inspected can be suppressed. In this case, it is possible to improve the recognition accuracy of a defect such as a minute scratch existing on the inspection surface.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a configuration of a first embodiment of a surface inspection apparatus according to the present invention.

FIG. 2 is a top view of the surface inspection apparatus shown in FIG.

FIG. 3 is an enlarged side view showing the periphery of a diffusion plate 2 and an O-ring 51;

FIG. 4 is a sectional view taken along the line AA of FIG. 3;

FIG. 5 is an example of an image of a seal surface of an O-ring 51 taken by a CCD camera 21;

FIG. 6 is a view showing C directly irradiated with illumination light without using the diffusion plate 2;
3 is an example of an image of a seal surface of an O-ring 51 taken by a CD camera 21.

FIG. 7 is a configuration diagram showing a configuration of a second embodiment of the surface inspection apparatus according to the present invention.

8 is a cross-sectional view illustrating an example of a structure of a seal member as an object to be inspected in the surface inspection apparatus of FIG.

FIG. 9 is an enlarged cross-sectional view of the seal surface shown in FIG.

FIG. 10 is a diagram showing a positional relationship among a seal member, a roll-type diffusion plate, and ring illumination.

FIG. 11 is a diagram illustrating a positional relationship between an inspection region of a seal member and a roll-type diffusion plate.

FIG. 12 is a diagram showing an example of an image of a sealing surface 81a of a sealing member 81 taken by a CCD camera 71 of a surface inspection device 61.

FIG. 13 shows a ring illumination 6 without using the roll diffusion plate 66;
Seal member 81 directly irradiated with the annular illumination light from 7
It is a figure which shows an example of the image of the sealing surface 81a of FIG.

FIG. 14 is a configuration diagram illustrating an example of a conventional surface inspection apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1, 61 ... Surface inspection device 2 ... Diffusion plate 3 ... Slit part 10 ... Drive device 11 ... Mounting shaft 21, 22, 23 ... CCD camera 31 ... Illumination device 41 ... Image processing device 51 ... O-ring 51a ... Seal surface 66 ... Roll diffuser 67 ... Ring illumination 81 ... Seal member 81a ... Seal surface

Claims (4)

[Claims] 1. A surface inspection apparatus for performing a defect inspection of an object to be inspected having a curved surface to be inspected, comprising: illuminating means for irradiating illumination light toward the inspected surface of the object to be inspected; A diffuser plate that transmits and diffuses illumination light from the imaging device that captures an image of the surface to be inspected of the object to be inspected, and a light-receiving amount of each pixel of image data captured by the imaging device. An image processing means for extracting a defect present on the surface to be inspected, wherein the diffusion plate has a shape that makes the illuminance distribution on the curved surface to be inspected substantially uniform. 2. The surface inspection apparatus according to claim 1, wherein the diffusion plate has a curved portion curved along the surface to be inspected. 3. The surface inspection apparatus according to claim 1, wherein the diffusion plate is provided with an opening for imaging the surface to be inspected by the imaging means. 4. The illuminating means has an opening for imaging the surface to be inspected in a central area, and is configured to irradiate annular illumination light. One end side is accommodated in the opening, and the annular end surface on the other end side is arranged so as to surround the surface to be inspected imaged by the imaging means, and the illumination light incident on the side surface is 2. The device according to claim 1, wherein the surface to be inspected is diffused from the annular end surface.
Surface inspection apparatus according to 1.