JPH09138201A - Surface inspection apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a surface inspection apparatus by which flaw can be detected even when the direction of the visual line of a camera is deviated by a method wherein beams of light at different wavelengths are separated from a light source for specular reflection and that for diffused reflection, a face to be inspected is imaged by the beams of light at the different wavelengths and image data is processed. SOLUTION: An imaging lens 13 focuses the image of a face, to be inspected, on imaging elements 15a, 15b. However, beams of light at wavelengths λ1, λ2 separated by a beam splitter 14, the image of the face, to be inspected, which is illuminated with a light source 11 at the wavelength λ1 is focused on the element 15a, and its image by a light source 12 at the wavelength λ2 is formed on the element 15b. Due to the difference in their illumination directions, the image in a specular reflection direction is formed on the element 15a, and the image in a diffused reflection direction is focused on the element 15b. Imaging outputs 16a, 16b from both elements have an opposite characteristic with reference to a change in reflection directivity, and the difference in the directivity is enlarged and detected by the difference between both outputs. Since the image in the two reflection directions is imaged by the same visual line of a camera 7, a difference image is obtained even when an object 17 to be inspected is changed up and down and the direction of the visual line of the camera 7 is changed, and a flaw can be detected.

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 having an improved detection rate of flaws or the like formed on a generally flat surface to be inspected such as a steel plate.

[0002]

2. Description of the Related Art Generally, the surface of a cold-rolled steel sheet or surface-treated steel sheet may have flaws due to minute irregularities in the production process. In particular, when the surface of the steel sheet is processed into a satin finish, the flaws of minute unevenness are unrecognizable because they are mixed in with the satin finish, but they become visible by post-treatment such as painting, so inspection at the time of shipping is not possible. It is essential. In order to inspect such flaws, at present, an inspection line is provided in addition to the production line, and an inspector performs a grindstone work on the surface at a predetermined position of the steel sheet, and visually inspects the flaw determination.
Such a whetstone is for raising flaws,
The convex flaws, which are smaller than those in the normal area, are strongly covered by the whetstone and become a glossy surface after the whetstone is applied. Therefore, a slight difference in gloss appears depending on the illumination direction and the line-of-sight direction, and inspection can be performed.

However, such a flaw inspection work is
It is necessary to uniformly grind the surface of the steel plate with as little unevenness as possible, and it takes skill to grind the stone according to the shape, hardness, tension, etc. of the steel plate surface, and the steel plate has a large area. Therefore, it is a labor-intensive work in addition to the heavy labor, so that productivity is limited, and automation of such flaw inspection work is required. For this reason, with respect to the grindstone mounting, an apparatus has been proposed in which a robot holds the grindstone and grinds the steel plate surface by a certain amount.

As a method of inspecting the surface of a steel sheet having a difference in gloss, two specular reflections of two image pickup elements are used by using specular reflection light and scattered reflection light as disclosed in Japanese Patent Application Laid-Open No. 5-188010. A method of enlarging the contrast by arranging in the regular reflection direction and the scattering reflection direction with respect to the light and the illumination of the scattered reflection light, capturing an image, and performing a difference calculation between the image data obtained from these two image sensors. Is proposed. This inspection method takes advantage of the phenomenon that the intensity of specular reflection light on the glossy surface is higher than that on the scattering surface, so the glossy surface is imaged brighter in the direction of specular reflection and conversely the glossy surface is imaged darker in the direction of scattering reflection. Therefore, by taking the difference, it is possible to extract only the information that depends on the difference in gloss, and it is possible to capture an image with a high contrast with respect to a flaw having a light gloss difference.

On the other hand, it is impossible to completely eliminate the unevenness of the application of the grindstone, and there is always a difference in gloss due to the unevenness of the application on the surface after the application of the grindstone. This gloss difference appears as noise for flaw detection, and removing it is important in terms of improving detection accuracy. Since the whetstone is applied by sweeping and polishing the whetstone in a certain direction, the noise also has the directionality of the certain direction, and the removal of the noise in the certain direction is disclosed in Japanese Patent Publication No. 7-21462. It is shown that the noise component can be deleted by using a smoothed image in the noise direction by such image processing.

[0006]

Since the conventional surface inspection apparatus is constructed as described above, the above-mentioned Japanese Patent Laid-Open No. 5-18 has been proposed.
With the configuration disclosed in Japanese Patent No. 8010, as a result of each imaging camera observing an inspection object from different line-of-sight directions, the inspection surface location where both imaging cameras can observe the same point is at the intersection of the line-of-sight of both imaging cameras. If there is only one point, for example, if the holding positions of both imaging cameras change, the observation points of the imaging cameras will differ, and for small area flaws, there will be common flaws between both specular and scattered reflection images. There is a problem that the image may not be captured and the contrast may be deteriorated. Such a phenomenon is more remarkable as the line-of-sight direction of the image pickup camera, a so-called prospective angle, is shallower with respect to the surface to be inspected, and particularly when the image pickup camera is held on a movable body to scan the surface to be inspected. In addition, the inspection performance is greatly impaired by vibration during scanning.

The smoothing method by image processing disclosed in Japanese Patent Publication No. 7-21462 is effective when the amount of calculation is relatively small, but when the area of a flaw is large, the smoothing range is large. Has to be increased, and when it is necessary to inspect over a large area such as the surface of a steel sheet, there are problems such as an increase in memory capacity and calculation time.

Further, the surface of the steel sheet is 1 mm or less to several meters.
A spot-like flaw having a relatively small size of about m but having a high contrast and a flaw having a low contrast but a relatively large area appear in a mixed manner. There are linear flaws and striped flaws in large areas with low contrast. For example, a linear flaw has a flaw with a width of several mm to 10 mm, and a striped flaw has a stripe pattern of about 1 cm pitch. Appears in an area of several tens cm square or more. When image processing these flaws, it is necessary to perform processing over a large area for large flaws to make the features stand out,
If the number of pixels to be processed is large, the amount of memory must be large, and the processing time and the cost of the processing circuit also increase, but there is a problem that the pixels cannot be roughened in order to detect a flaw in a small area.

The present invention has been made to solve the above problems, and a surface inspection apparatus capable of maintaining a good detection rate for a flaw on a surface to be inspected even if a shift occurs in the line-of-sight direction of an imaging camera. Aim to get.

Further, according to the present invention, the image output for the flaws appearing as the above-mentioned striped pattern which becomes noise in the image processing for the flaw detection using the smoothed image and the non-smoothed image is eliminated to obtain the target flaw. The object is to obtain a surface inspection device that can accurately detect only

It is another object of the present invention to provide a surface inspection apparatus capable of performing image processing for detecting a flaw at high speed regardless of the size of the flawed area on the surface to be inspected.

Another object of the present invention is to provide a surface inspection device which can efficiently perform inspection work without manually performing inspection work including grindstone mounting.

[0013]

According to a first aspect of the present invention, there is provided a surface inspection apparatus having a first wavelength arranged in a regular reflection direction in which an irradiation angle of light is equal to an angle of view when an image of a surface to be inspected is picked up. Light source for irradiating regular reflection light, and light having a second wavelength different from the first wavelength and arranged in a scattering reflection direction in which the irradiation angle of the light is different from the perspective angle when the surface to be inspected is imaged. A light source for scattering reflection for irradiating, and a separating means for separating the light of each of the different wavelengths captured by the imaging optical system coaxial from the oblique prospective angle position with respect to the surface to be inspected, for each wavelength. An image pickup element on which an image of the surface to be inspected is formed by the light of different wavelengths separated by the separating means, and image data of the surface to be inspected imaged by the image pickup element for each light of the different wavelength is processed. However, the flaws on the surface to be inspected or It is obtained so as to include an image data processing means for detecting a detection point.

In the surface inspection apparatus according to the second aspect of the present invention, an image for detecting a flaw or a detected point on the surface to be inspected by obtaining difference image data of image data of the surface to be inspected for each different wavelength. The data processing means is provided.

A surface inspection apparatus according to a third aspect of the present invention is a light source for irradiating the surface to be inspected with light, and a dividing means for dividing the light taken in from an oblique angle position oblique to the surface to be inspected. And a plurality of image pickup devices on which images of the surface to be inspected are formed based on the respective lights divided by the dividing means, and when detecting a flaw on one of the plurality of image pickup devices A filter provided in the image forming optical path of the image pickup device for forming a smoothed image smoothed in the noise direction on a linear or striped flaw in a certain direction on the surface to be inspected, which becomes a noise component. Element, image data obtained from the image pickup element in which the smoothed image is formed in the same visual field as the visual field in which the smoothed smoothed image is obtained, and the image pickup element not passing through the filter element Of the unsmoothed image Performs arithmetic processing with the image data, wherein the said noise component of the surface to be inspected is obtained by configured with the image data processing means for detecting flaws of different shapes.

A surface inspection apparatus according to a fourth aspect of the present invention is configured to include a one-dimensional low-pass filter formed of a one-dimensional grating or a cylindrical lens as a filter element.

In the surface inspection apparatus according to the invention of claim 5, in order to detect a flaw having a shape different from the noise component of the surface to be inspected, an image of a non-smoothed image obtained by an image pickup element without a filter element. The image data processing means for subtracting the image data of the smoothed image obtained by the image pickup element through the filter element from the data is configured.

A surface inspection apparatus according to a sixth aspect of the present invention is composed of a light-transmissive scattering medium having a scattering property only in the radial direction with one point as the center, and is arranged in the image forming optical path of the imaging lens. The scattering center position is located in a plane including the optical axis of the image pickup lens and perpendicular to the surface to be inspected, and passing through the center of the image pickup lens and parallel to the surface to be inspected. It is configured to include the filtered filter element.

According to a seventh aspect of the present invention, there is provided a surface inspection apparatus including a filter element having a surface perpendicular to a principal ray.

According to the eighth aspect of the present invention, in a surface inspection apparatus, image data of a non-smoothed image obtained by an image pickup device not passing through a filter element is subjected to a smoothed image obtained by an image pickup device passing through the filter element. The image data processing means for performing the subtraction processing of the image data and detecting a flaw having a shape different from the noise component of the surface to be inspected.

According to a ninth aspect of the present invention, there is provided a surface inspecting apparatus having a filter element which is light-transmissive and has concentric concavo-convex patterns formed on the surface thereof.

A surface inspection apparatus according to a tenth aspect of the present invention is a brightness average value measuring means for measuring a brightness average value of a smoothed image and a non-smoothed image, and the smoothness measured by the brightness average value measuring means. Amplification of the image output of the smoothed image and the non-smoothed image for equalizing the average brightness of the smoothed image and the non-smoothed image based on the average brightness value of the non-smoothed image And a variable amplification rate amplifying means for adjusting the degree.

The surface inspection apparatus according to the invention of claim 11 separates light of different wavelengths captured by the coaxial imaging optical system from the oblique angle position with respect to the surface to be inspected through the imaging lens. The separating means, the dividing means for dividing the light amounts of the different wavelengths separated by the separating means, and the images of the surface to be inspected are formed based on the light of the respective wavelengths divided by the dividing means. A pair of imaging elements provided for each wavelength to be imaged, and a line in a certain direction on the surface to be inspected, which becomes a noise component when a flaw is detected on one of the pair of imaging elements. Filter element provided in the image forming optical path of the image pickup device for forming a smoothed image smoothed in the noise direction with respect to a linear or striped flaw, and the irradiation angle of light images the surface to be inspected. And the angle of view A regular reflection light source that is arranged in the direction of regular reflection and irradiates light of one of the different wavelengths, and a scattering reflection direction in which the irradiation angle of light is different from the perspective angle for imaging the surface to be inspected. Non-smooth non-smooth image data obtained from the scattered reflection light source that is disposed and emits light having a wavelength different from the one wavelength, image data obtained from the image pickup device on which the smoothed image is formed in the same field of view, and the filter device. The image data processing means for performing an arithmetic operation with the image data of the digitized image is configured.

The surface inspection apparatus according to the twelfth aspect of the present invention is composed of a light-transmissive scattering medium having a scattering property only in the radiation direction centering on one point, and is arranged in the image forming optical path of the imaging lens. The scattering center position is located in a plane including the optical axis of the image pickup lens and perpendicular to the surface to be inspected, and passing through the center of the image pickup lens and parallel to the surface to be inspected. Or a filter element whose surface is perpendicular to the chief ray.

The surface inspection apparatus according to the thirteenth aspect of the present invention is a brightness average value measuring means for measuring a brightness average value of a smoothed image and a non-smoothed image, and the smoothness measured by the brightness average value measuring means. Amplification of the image output of the smoothed image and the non-smoothed image for equalizing the average brightness of the smoothed image and the non-smoothed image based on the average brightness value of the non-smoothed image The image data processing means having the amplification factor variable amplification means for adjusting the degree is provided.

According to a fourteenth aspect of the present invention, in the surface inspection apparatus, the difference calculation result between the smoothed image and the non-smoothed image obtained on the basis of the light source for regular reflection and the light source for scattering reflection are obtained for the same visual field. An image data processing means for obtaining a difference calculation result between the smoothed image and the non-smoothed image obtained based on the above and further performing a difference calculation between both the difference calculation results.

A surface inspection apparatus according to a fifteenth aspect of the present invention is provided with at least two series of image processing circuits for detecting flaws or detected points on the surface to be inspected, and one of the image processing circuits is provided. The series of image processing circuits creates an image in which the average value of the intensity values of all adjacent pixels of the original image is compressed into one pixel as a new intensity value, and the image is generated based on the compressed image. Processing and detection of flaws on the surface to be inspected are performed, and another series of image processing circuits in the image processing circuit are configured to perform local image processing and flaws on the surface to be inspected for each set of a fixed number of adjacent pixels. Is configured to be sequentially detected.

According to a sixteenth aspect of the present invention, in a surface inspecting apparatus, at least a light source, an image pickup lens and an image pickup element are provided for a polishing section for sweep polishing a surface to be inspected in a fixed direction at a predetermined pressure and a predetermined amount. A movable arm mounted on the same arm tip or a different arm tip from the optical system that it has, and a drive for moving the movable arm and moving the polishing section and the optical system on the surface to be inspected. And a mechanism.

The surface inspection apparatus according to the seventeenth aspect of the present invention is such that the image data processing means is not attached to the movable arm and is provided non-movably separately from the optical system.

[0030]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below. Embodiment 1 FIG. 1 is a partial configuration diagram showing a surface inspection apparatus according to a first embodiment of the present invention. In the figure, 11 is a light source for irradiating parallel rays of light emission wavelength λ1 (light source for specular reflection), 12 is a light source for irradiating parallel light rays of emission wavelength λ2 (light source for scattering reflection), and 13 is an imaging lens. Reference numeral 14 is a beam splitter (separating means) having different reflection characteristics depending on the wavelength. In this embodiment, the wavelength λ
It has a characteristic of transmitting light of wavelength 1 and reflecting light of wavelength λ2. 15a and 15b are image pickup devices such as CCD,
Reference numeral 7 denotes an object to be inspected, such as a steel plate, whose flaws appearing on the surface are inspected.

Next, the operation will be described. DUT 1
When 7 has a certain scattering property and its scattering directivity differs depending on the position, the reflected light intensity is concentrated in the specular reflection direction as the scattering property shows a sharp directivity closer to a mirror surface. For this reason, when a surface close to a mirror surface is viewed from the direction of regular reflection with respect to the light emitted from the light source, it looks bright, but if the line-of-sight direction deviates from the direction of regular reflection, the amount of reflected light decreases sharply and appears dark. Become. On the other hand, on the surface having a strong scattering property, the light amount in the specular reflection direction is small, but the light amount is different from the specular reflection direction, that is, the decrease in the light amount in the scatter reflection direction is relatively small. Therefore, when the subject is observed from the specular reflection direction, the portion close to the mirror surface appears bright and rises, and when observed from the scattering reflection direction, the portion close to the mirror surface appears dark and sunk. Light source 11 in this embodiment
Is arranged at an angular position where the line-of-sight direction of the image pickup camera is specular reflection, and the light source 12 is arranged at an angular position where scatter reflection is caused.

The image pickup lens 13 forms an image of the surface to be inspected on the image pickup device 15a and the image pickup device 15b. Since the beam splitter 14 separates the light of wavelengths λ1 and λ2, the image pickup device 15a has a wavelength of λ1 and λ2. An image of the surface to be inspected illuminated by the light from the light source 11 having the wavelength λ1 and an image of the surface to be inspected being illuminated by the light from the light source 12 having the wavelength λ2 are formed on the imaging element 15b. Due to the difference in the illumination direction, an image in the specular reflection direction is captured by the image sensor 15a, and an image in the scattered reflection direction is captured by the image sensor 15b. Imaging output 16a and imaging element 15b from these imaging elements 15a
Since the image pickup output 16b from the above shows the opposite characteristic with respect to the change of the reflection directivity of the surface as described above, the difference in the directivity characteristics can be enlarged and detected by taking the difference between the outputs of the two.

As described above, in this embodiment, images in two reflection directions at the same line of sight of the image pickup camera, that is, an image of the surface to be inspected by regular reflection and the same surface to be inspected as the surface to be inspected by scattering reflection are the same. Since the image of the surface can be taken, even if the object 17 to be inspected fluctuates up and down or the line-of-sight direction of the imaging camera is tilted, the respective images do not differ and a good difference image can be obtained. Therefore, it becomes possible to detect a flaw appearing on the surface to be inspected with good contrast. Further, the image pickup lens 13 may be provided after the beam splitter 14, and in this case, the distance between the image pickup lens and the image pickup devices 15a and 15b can be shortened, so that an image with a wide field of view can be easily obtained. Two lenses are required, and the line of sight of each imaging lens must be adjusted accurately.

Embodiment 2 2 is a partial configuration diagram showing a surface inspection device according to a second embodiment of the present invention. In the figure, the same or corresponding parts as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. 21 is a light source for illuminating the surface to be inspected, 23 is a half mirror (dividing means), and 24 is 1
The dimensional low-pass filter elements 26a and 26b are image outputs from the image pickup elements 15a and 15b.

Next, the operation will be described. In the inspection of cold-rolled steel sheets, a surface inspection method is generally known in which a small amount of unevenness is polished in a certain direction with a grindstone of appropriate roughness, and microscopic unevenness is raised to visually inspect it. Since it is possible to visually identify and detect flaws because there are uniform whetstone traces and uneven whetstone strength in the same direction, it becomes a noise source when performing automatic inspection by image processing, and the inspection is performed. It becomes an obstacle. In this embodiment,
The imaged surface of the object 27 to be inspected, which is illuminated by the light source 21 and has a grindstone trace in a certain direction, is imaged by the imaging lens 13, but the half mirror 23 is provided after the imaging lens 13 and the surface to be inspected. Of the image of the image pickup device 15a and the image pickup device 15b.
One-dimensional low-pass filter element 2 is provided on the optical path on the 5a side.
4 are arranged. The one-dimensional low-pass filter element 24 has a property of generating a blurred image in the grindstone trace direction on the image pickup element 15a and is configured by a one-dimensional grating or a cylindrical lens. Since the image output 26a from the image pickup device 15a is an image blurred in the grindstone trace direction as described above, that is, a smoothed image, only uniform information remains in the grindstone mounting direction due to the grindstone mounting, and the others are smooth. Disappears and disappears. This image output 26a is subtracted from the non-smoothed image that is the regular image output 26b that does not pass through the one-dimensional low-pass filter element 24, and only the noise component caused by the grinding stone is erased.

Therefore, in this embodiment, since the smoothed image is optically created and the noise component caused by the grinding stone is removed from the non-smoothed image, the noise component caused by the grinding stone is removed. It is possible to obtain an image of the surface to be inspected of the object to be inspected, in which the target flaw is satisfactorily imaged, and high-speed inspection becomes possible.

Embodiment 3 3 is a plan view showing the configuration of a filter element used in a surface inspection apparatus according to Embodiment 3 of the present invention, and FIG. 4 is an explanatory view showing the optical arrangement position of the filter element in an image pickup camera. The arrangement of the imaging system and the illumination system is the same as in FIG. 2 described in the second embodiment.
Is the same as 4, parts that are the same as or correspond to those in FIG. 2 are given the same reference numerals, and descriptions thereof will be omitted. In the figure, reference numeral 53 indicates an image pickup element surface.

Next, the operation will be described. The optical axis A of the imaging lens 13 is at a predetermined angle θ with respect to the normal line of the inspection object 27.
It is installed in a tilted state. In this case, the inspection object 27
The image on the image pickup element surface 53 for the image of the line segment indicated by the points O1 and O2 above is formed at the intersection of the chief ray passing through the center of the image pickup lens 13 and the image pickup element surface 53, and I1 and I2. It becomes the image of the line segment shown by. Here, the points O1 and O2 are the inspection object 27 on the optical axis A of the imaging lens 13.
And a line segment parallel to the line B indicating the direction of inclination of the optical axis A. At this time, considering the extension of the line segment represented by the points O1 and O2 toward infinity in the direction of the point O2,
When the point at infinity is O ∞, the image at that point is the intersection position I ∞ between the chief ray C parallel to the line B and the image pickup element surface 53. That is, the semi-infinite line represented by the points O1, O2, and O∞ is projected on the image pickup element surface 53 as a line segment represented by the points I1, I2, and I∞, and the straight line B All line segments parallel to are converted into radial line segments centered on the point I ∞ on the image pickup element surface 53. As described above, in an image pickup system having an obliquely inclined line of sight, parallel lines in the direction of the straight line B are not parallel on the image pickup element surface 53, and smoothing of the image in the direction of the straight line B cannot be configured by a one-dimensional low-pass filter. .

On the other hand, the filter element shown in FIG. 3 is made of a light-transmissive plate material having concentric minute irregularities on the surface as shown in the figure, and the transmitted light is scattered by the irregularities. The scattering direction of the scattered light is radial from the center of the concentric circles of the irregularities. This filter element is arranged between the image pickup lens 13 and the image pickup element surface 53 with the surface perpendicular to the principal ray C, with the chief ray C in FIG. At this time, the light rays that have passed through the filter element are scattered in a radial pattern centered on the point I ∞ on the image pickup element surface 53. That is, the image of the surface of the object 27 to be inspected picked up by the image pickup element surface 53 becomes an image smoothed in the direction parallel to the straight line B.

As described above, in this embodiment, the filter element is made of the light-transmitting plate material having concentric concavo-convex projections and depressions, so that the object to be inspected even in an imaging system having an obliquely inclined line of sight. Since it is possible to uniformly smooth the direction of inclination of the line of sight of the surface to be inspected 27, if the filter element is used instead of the one-dimensional low-pass filter 24 in the second embodiment, the direction of the straight line B It is possible to effectively remove the noise component caused by the whetstone.

Embodiment 4 FIG. FIG. 5 is an image data processing means 60 in the surface inspection apparatus according to the fourth embodiment of the present invention.
FIG. 3 is a block diagram showing the configuration of FIG. In the figure, reference numeral 61a denotes a smoothed image pickup means, which is shown in FIG.
5 corresponds to the filter element 24 and the image pickup element 15a shown in FIG. 3, and the filter element and the image pickup element surface 53 shown in FIGS. Reference numeral 61b denotes a non-smoothed image pickup means, which corresponds to the image pickup element 15b without the filter element 24 in the second embodiment shown in FIG. 2 or the image pickup element surface without the filter element in the third embodiment not shown. . Reference numeral 62a is a brightness average value measuring means for measuring the brightness average value of the smoothed image output from the smoothed image capturing means 61a, and 62b is the brightness average value of the non-smoothed image output from the non-smoothed image capturing means 61b. Luminance average value measuring means 63a for measuring, amplification factor variable amplifier (amplification factor variable amplification means) 63a for amplifying the smoothed image output outputted from the smoothed image capturing means 61a, and 63b non-smoothed image capturing means 61b.
A variable amplification factor amplifier (amplification factor variable amplification means) for amplifying the non-smoothed image output outputted from the reference numeral 64, a smoothed image and a non-smoothed image which are respectively amplified by the variable amplification factor amplifiers 63a and 63b and outputted. It is a subtracter that performs a subtraction process between the image data of.

Next, the operation will be described. The smoothed image output is sent to and amplified by the variable amplification factor amplifier 63a, and the non-smoothed image output is sent to and amplified by the variable amplification factor amplifier 63b. The average brightness value is measured by the average value measuring means 62a and 62b. The brightness average value measuring means has a configuration in which an optical path separating means such as a half mirror is installed in front of the image pickup device to divide the light quantity into two equal parts and the total light quantity after separation is measured by a photodetector or the like. . It is also possible to electrically integrate and average the output of the smoothed image and the output of the non-smoothed image after imaging. This luminance average value is sent to the variable amplification factor amplifiers 63a and 63b so that the average luminance values of the smoothed image output from the variable amplification factor amplifier 63a and the non-smoothed image output from the variable amplification factor amplifier 63b become equal. , The amplification factor of the amplification factor variable amplifier 63a is a constant multiple of the reciprocal of the brightness average value measured by the brightness average value measuring means 62a, and the amplification factor variable amplifier 6
The amplification factor of 3b is automatically adjusted to a constant multiple of the reciprocal of the average brightness value measured by the average brightness value measuring means 62b. Further, the image output output from the variable gain amplifier 63a is subtracted from the image output output from the variable gain amplifier 63b.
The subtraction process is performed by 4, and the difference between the two image outputs is obtained and output.

When the noise component caused by the grinding stone described in the second and third embodiments is removed by using the smoothed image and the non-smoothed image, the brightness of the image output values must be equal. The noise component cannot be made completely zero, but by using the configuration of this embodiment, the image output values of the smoothed image and the non-smoothed image are controlled so that they are always equal to each other. When applied as a processing circuit of No. 3, a good noise removing effect can be obtained with respect to a noise component caused by grinding stones.

Embodiment 5 FIG. FIG. 6 is a partial configuration diagram showing a surface inspection device according to a fifth embodiment of the present invention. In the figure, the same or corresponding parts as those in FIGS. 1 and 2 are designated by the same reference numerals, and the description thereof will be omitted. 23a and 23
b is a half mirror, 76a and 76b are the filter elements described in the second or third embodiment, and 77a to 77d are image pickup elements.

In this embodiment, the specular reflection image, the scattered reflection image, and the smoothed image of each image of the object 17 to be inspected are picked up with the same line of sight. The light source 11 is arranged at an angular position where the line-of-sight direction of the imaging camera is specularly reflected, and the beam splitter 14 separates the light of the wavelength λ1 and the wavelength λ2, and the separated light of the wavelength λ1 is reflected by the half mirror 23b. The light having the wavelength λ2 goes toward the half mirror 23a. The half mirror 23b splits the optical path into two, and one of the split light beams passes through the filter element 76b and the image pickup element 77c.
The smoothed specular reflection image is displayed on the other side, and the other light is imaged by the image sensor 7.
A specular reflection image is formed on 7d. Further, the light source 12 is arranged at an angular position where the line-of-sight direction of the imaging camera is scattered and reflected, is reflected by the beam splitter 14, and is further divided into two optical paths by the half mirror 23a, and one light is imaged by the imaging element 77a. The scattered reflection image smoothed above,
The other light also forms a scattered reflection image on the image sensor 77b.

Therefore, in this embodiment, the non-smoothed image and the smoothed image for the two reflection directions of the specular reflection direction and the scattering reflection direction are picked up with respect to the light of wavelength λ1 and the light of wavelength λ2 in the same line of sight of the image pickup camera. By performing the subtraction process between the non-smoothed image and the smoothed image, it is possible to obtain a good noise removal effect with respect to the noise component caused by the whetstone in the two reflection directions of the regular reflection direction and the scattering reflection direction. By further performing the subtraction process between the image outputs from which these noises have been removed, the effect of highlighting the flaw appearing on the surface to be inspected described in the first embodiment can be obtained. A surface inspection apparatus that can synergistically achieve the effect described in the second or third embodiment and the effect described in the first embodiment can be obtained. Even if the body 17 fluctuates up and down or the line-of-sight direction of the imaging camera is tilted, it is possible to always obtain a good image from which the noise component has been removed with respect to the image in the same region.

Embodiment 6 FIG. FIG. 7 is an image data processing means 80 in the surface inspection apparatus according to the sixth embodiment of the present invention.
FIG. 3 is a block diagram showing the configuration of FIG. This image processing circuit
For example, it is applied to the image output obtained as a result of the subtraction processing by the subtractor 64 described in the fourth embodiment. In the figure, 81 and 83 are frame memories, 82 is an averaging circuit for averaging intensity values of a predetermined number N of pixels,
Reference numeral 84 is an image compression circuit (a series of image processing circuits) that compresses an image to a pixel number of 1 / N by averaging by an averaging circuit 82, 85 is a local image processing circuit (a series of image processing circuits), Reference numeral 86 is a local image processing circuit (another series of image processing circuits), and 87 is a defect recognizing circuit such as a flaw appearing on the surface to be inspected.

Next, the operation will be described. The image information sent from the subtractor 64 is accumulated in the frame memory 81, and then the image compression circuit 84 and the local image processing circuit 86.
And sent to. With respect to the image information sent to the image compression circuit 84, an average value of intensity values is calculated for each predetermined number N of pixels by the averaging circuit 82, and this average value is stored in the frame memory 83. At this time, since the image information obtained by compressing the average value of the predetermined number N of pixels as the intensity value of one pixel is stored in the frame memory 83, the frame memory 8
The number of pixels of the image information stored in 3 is 1 with respect to the total number of pixels.
Will be compressed to / N. Further, the image information accumulated in the frame memory 83 is sent to a local image processing circuit 85, processed and sent to a defect recognition circuit 87 for recognizing a defect such as a flaw.

On the other hand, in the local image processing circuit 86, all pixels are subjected to local processing and sent to the defect recognition circuit 87, and the detection result of the flaw appearing on the surface to be inspected is output.

Therefore, in this embodiment, the image information that has passed through the image compression circuit 84 is used to detect a flaw that is very large with respect to the pixel size. For example, when filtering is performed, the original image is directly processed. In case of doing, it is necessary to operate on a very large number of pixels, whereas
Processing can be performed with a filter size of 1 / N pixel, which enables high-speed processing and cost reduction of circuit configuration.

Embodiment 7 FIG. FIG. 8 is a perspective view showing the structure of the surface inspection apparatus according to the seventh embodiment of the present invention. In the figure, 91 is a holding arm (movable arm) that holds the imaging unit of the surface inspection apparatus described in the fifth embodiment, 92 is a holding arm (movable arm) that holds a grindstone mounting head (polishing unit) 92a, and 93. Is a drive mechanism for the holding arm, and 94 is an image processing unit having the image data processing means for performing the image data processing described in the fifth embodiment and the image data processing means described in the fourth and sixth embodiments. ,
Reference numeral 95 is a drive mechanism control unit, 96 is a system control unit, and 97 is a steel plate to be inspected.

Next, the operation will be described. The drive mechanism control unit 95 controls the drive mechanism 93 to grind the surface of the steel plate 97 to be inspected with a predetermined pressure for a predetermined number of times by the grindstone mounting head held by the holding arm 92. continue,
The drive mechanism control unit 95 controls the drive mechanism 93 to scan the surface of the steel sheet to be inspected 97 on which the grindstone is applied with the imaging unit held by the holding arm 91 at a constant speed.
The imaging device 91 transmits the captured image information to the image processing unit 94. The image processing unit 94 is the sixth embodiment.
The image pickup section held by the holding arm 91 has a one-dimensional image pickup element arranged perpendicularly to the feeding direction of the steel sheet to be inspected by the drive mechanism 93.
A two-dimensional image of the surface of the steel plate 97 to be inspected is formed by scanning.

The image processing unit 94 detects noise components from the specular reflection image and the scattered reflection image sent from the image pickup device shown in FIG. 6 of the fifth embodiment, and the smoothed image and the smoothed image of each of them. The removed difference image is produced, the flaw appearing on the surface of the steel plate 97 to be inspected is detected by the two-system image processing circuit shown in the sixth embodiment, and the inspection result is output to the system control unit 96. The system control unit 96 manages the thickness, material, and surface condition of the steel plate 97 to be inspected, in addition to ranking the steel plate 97 to be inspected and notifying the inspection workers, and the drive mechanism control unit 95 controls the polishing pressure and the number of times of polishing. And so on.

[0054]

As described above, according to the first aspect of the present invention, the specular reflection light source arranged in the direction of specular reflection equal to the prospective angle when the surface to be inspected is imaged and the scattering different from the prospective angle. The scattering reflection light source arranged in the direction of reflection irradiates the surface to be inspected with light having different wavelengths, and the imaging optical system coaxially captures the light at different angles from the oblique angle to the surface to be inspected. The light having the wavelength is separated for each wavelength by the separating means, and the image data of the surface to be inspected imaged by the image sensor for each of the different wavelengths is processed by the image data processing means to detect a flaw or a detected point on the surface to be inspected. Since the image data of the surface to be inspected, which is picked up by the light emitted from the light source for specular reflection and the light source for scattering reflection, is processed by the image data processing means, the object to be inspected is detected. It is possible to emphasize the characteristics of the reflection directivity for the same region of, it becomes possible to particularly emphasize the difference between the region of the surface to be inspected close to the mirror surface and the area of the surface to be inspected with irregularities, It is possible to easily and reliably detect flaws appearing on the surface to be inspected, and further, even if the surface to be inspected fluctuates up and down or the direction of the line of sight at the time of imaging is inclined, the specular reflection light source and the scattering The image of the region of the surface to be inspected, which is picked up by the light emitted from the light source for reflection, is not displaced, and the effect on the inspection of the surface to be inspected can be eliminated.

According to the second aspect of the invention, the image data processing means obtains the difference image data of the image data of the surface to be inspected for each different wavelength, and detects the flaws appearing on the surface to be inspected. In particular, the image of the area of the surface to be inspected, which is imaged by the light emitted from the light source for scattered reflection, with respect to the image of the area of the surface to be inspected, which is imaged by the light emitted from the light source for specular reflection. Difference image, the area of the surface to be inspected close to the mirror surface becomes an image of outstanding brightness compared to the area of the surface to be inspected with unevenness,
A flaw appearing on the surface to be inspected can be easily and surely detected, and even if the surface to be inspected fluctuates up and down or the line-of-sight direction at the time of imaging is inclined, the specular reflection light source and the The image of the region of the surface to be inspected that is imaged by the light emitted from the light source for scattering reflection does not shift,
There is an effect that it is possible to eliminate adverse effects on the inspection of the surface to be inspected.

According to the third aspect of the invention, the light source for irradiating the surface to be inspected with light, the dividing means for dividing the light taken in from the oblique angle position with respect to the surface to be inspected, A plurality of image pickup elements on which images of the surface to be inspected are formed based on the respective lights divided by the dividing means,
A smoothed image smoothed in the noise direction on a linear or striped flaw in a certain direction of the surface to be inspected, which becomes a noise component when a flaw is detected on one of the plurality of image pickup elements. A filter element provided in the image forming optical path of the image pickup device for forming an image, and the image pickup in which the smoothed image is formed in the same visual field as the visual field in which the smoothed smoothed image is obtained. An arithmetic process is performed between image data obtained from an element and image data of a non-smoothed image obtained by the image pickup element that does not pass through the filter element, and a flaw having a shape different from the noise component of the surface to be inspected is generated. Since it is configured to include an image data processing unit for detecting, to the surface to be inspected excluding an image of a linear or striped flaw in a certain direction of the surface to be inspected, which becomes a noise component during flaw detection. , Said Neu It is possible to detect a flaw different from a flaw as a component, and further it is possible to eliminate an adverse effect on the inspection of the surface to be inspected due to the vertical movement of the surface to be inspected or the inclination of the line of sight when imaging. effective.

According to the fourth aspect of the present invention, since the one-dimensional low-pass filter constituted by the one-dimensional grating or the cylindrical lens is provided as the filter element, the inspected object which becomes a noise component at the time of flaw detection. It is possible to detect a flaw different from the flaw that is the noise component that excludes an image of a linear or striped flaw in a certain direction of the surface, and further, the line of sight when the surface to be inspected fluctuates vertically or is imaged. There is an effect that it is possible to eliminate an adverse effect on the inspection of the surface to be inspected due to the inclination of the direction.

According to the fifth aspect of the invention, the image data processing means is configured to subtract the image data of the smoothed image from the image data of the non-smoothed image. It is possible to detect a flaw different from the flaw that is the noise component with respect to the surface to be inspected, by eliminating the image of a linear or striped flaw in a certain direction of the surface to be inspected, and further, the surface to be inspected Has the effect of eliminating the adverse effect on the inspection of the surface to be inspected due to the vertical movement of the vertical axis or the inclination of the line-of-sight direction during imaging.

According to the sixth aspect of the present invention, the light-transmitting type scattering medium having a scattering property only in the radiation direction centering on one point is disposed in the image forming optical path of the imaging lens, and the scattering A filter whose center position is located in a plane including the optical axis of the imaging lens and perpendicular to the surface to be inspected, and on a line of a principal ray passing through the center of the imaging lens and parallel to the surface to be inspected. Since it is configured to include elements,
Even in an imaging system having an obliquely inclined line of sight, it is possible to effectively remove noise components caused by, for example, grinding stones, compared to the case where a one-dimensional low-pass filter is used, and a good image of the surface to be inspected is actually obtained. It can be obtained in a short time, and has the effect of enabling high-speed and reliable inspection.

According to the seventh aspect of the present invention, since the surface is provided with the filter element arranged perpendicularly to the principal ray, even an image pickup system having an obliquely inclined line of sight is caused by, for example, grindstone mounting. It is possible to more effectively remove a noise component and the like, and it is possible to obtain a good image of the surface to be inspected in real time, which has the effect of enabling high-speed and reliable inspection.

According to the invention described in claim 8, since the image data processing means is configured to perform the subtraction processing of the smoothed image with respect to the non-smoothed image, even in an image pickup system having an obliquely inclined line of sight, for example, a whetstone is applied. It is possible to effectively remove the noise component caused by the subtraction process, and it is possible to obtain a good image of the surface to be inspected in real time. is there.

According to the ninth aspect of the present invention, since the filter element is formed of a light transmission type scattering medium and has concentric concavo-convex patterns formed on the surface thereof, an image having an oblique line of sight is picked up. Even in the system, it is possible to effectively remove noise components such as those caused by grinding stones on the surface to be inspected, and a good image of the surface to be inspected can be obtained in real time, enabling high-speed and reliable inspection. Has the effect of

According to a tenth aspect of the present invention, a brightness average value measuring means for measuring the brightness average value of the smoothed image and the non-smoothed image, the smoothed image measured by the brightness average value measuring means, and Based on the luminance average value of the non-smoothed image, the amplification degree of the image output of the smoothed image and the non-smoothed image for adjusting the luminance average value of the smoothed image and the non-smoothed image is adjusted. And a variable amplification means for changing the amplification factor. Therefore, excellent noise removal capable of reducing the noise component to almost zero by image data processing between the image outputs of the smoothed image and the non-smoothed image having the same average brightness value. There is an effect that can be done.

According to the eleventh aspect of the present invention, the light having one of different wavelengths is irradiated to the surface to be inspected from the light source for specular reflection arranged in the direction of specular reflection equal to the angle of view, and the light is irradiated. The light having a wavelength different from the one wavelength is radiated from the light source for scattering reflection arranged in the direction of scattering reflection having an angle different from the prospective angle, and through the imaging lens from a prospective angle position oblique to the surface to be inspected. The light of different wavelengths captured by the coaxial imaging optical system is separated by the respective separating means, the separated light amounts of the different wavelengths are further divided by the dividing means, and the surface to be inspected is based on the divided light of each different wavelength. Image on each pair of imaging elements provided for each wavelength, and becomes a noise component at the time of flaw detection on the optical path of one of the paired imaging elements. Inspected A filter element for forming a smoothed image smoothed in the noise direction with respect to a linear or striped flaw in a certain direction, is arranged between the smoothed image and the non-smoothed image for the same visual field. Since it is configured to perform image data calculation processing by the image data processing means at the same time, it is possible to effectively remove noise components and to detect flaws and the like appearing on the surface to be inspected, which is a detection target, in a conspicuous manner. There is an effect.

According to the twelfth aspect of the invention, the light-transmitting type scattering medium having a scattering property only in the radiation direction centering on one point is disposed in the image forming optical path of the image pickup lens, and the scattering The center position is arranged in a plane including the optical axis of the imaging lens and perpendicular to the surface to be inspected, and on a line of a principal ray passing through the center of the imaging lens and parallel to the surface to be inspected, or Since the filter element is arranged so that its surface is perpendicular to the chief ray, it is possible to remove noise components caused by, for example, grinding stones even in an imaging system having an oblique line of sight. Therefore, the processing for obtaining a good image of the surface to be inspected can be brought close to the real-time processing, and there is an effect that a high-speed and reliable inspection can be performed.

According to the thirteenth aspect of the present invention, a brightness average value measuring means for measuring the brightness average value of the smoothed image and the non-smoothed image, the smoothed image measured by the brightness average value measuring means, and Based on the luminance average value of the non-smoothed image, the amplification degree of the image output of the smoothed image and the non-smoothed image for adjusting the luminance average value of the smoothed image and the non-smoothed image is adjusted. Since the image data processing means having the variable amplification factor amplification means is provided, it is possible to effectively perform the calculation between the image data of the smoothed image and the non-smoothed image in the image data processing means. It is possible to effectively remove, for example, a noise component caused by a grindstone even in an imaging system having a line of sight that is obliquely inclined, and a good image of the surface to be inspected can be obtained in real time. It has the effect of allowing the testing of fast and reliable test surface.

According to the fourteenth aspect of the invention, for the same field of view, the difference calculation result between the smoothed image and the non-smoothed image obtained based on the regular reflection light source and the scattering reflection light source are used. Since the image data processing means for obtaining the difference calculation result between the obtained smoothed image and the non-smoothed image and further performing the difference calculation between the difference calculation result are arranged, the line of sight inclined Even in the imaging system having, for example, there is an effect that a noise component caused by the grinding stone can be effectively and almost completely removed and the flaw can be surely detected.

According to the fifteenth aspect of the present invention, at least two series of image processing circuits for detecting flaws or detected points on the surface to be inspected are provided, and one series of images of the image processing circuits is provided. The processing circuit creates an image in which one pixel is compressed with an average value of the intensity values of all pixels of a predetermined number of adjacent pixels of the original image as a new intensity value, and the image processing and the image processing are performed based on the compressed image. Defects on the surface to be inspected are detected, and another series of image processing circuits in the image processing circuit performs local image processing and detection of defects on the surface to be inspected for each set of a fixed number of adjacent pixels. Since it is configured so as to include image data processing means that performs sequentially, it is possible to deal with both the flaws appearing in the wide area of the surface to be inspected and the flaws appearing in the narrow area, especially for the flaws appearing in the wide area of the inspected surface. Image data to be processed is compressed Without increasing the filter size of the image processing from Rukoto is effective to reduce the cost of the image processing circuit can be shortened image data processing time.

According to the sixteenth aspect of the present invention, there is provided an optical unit having a polishing section for sweep-polishing a surface to be inspected in a predetermined direction at a predetermined pressure by a predetermined amount, and at least a light source, an image pickup lens and an image pickup element for the surface to be inspected. A movable arm mounted to the same arm tip or a different arm tip from the system, and a drive mechanism for moving the movable arm and moving the polishing section and the optical system on the surface to be inspected. Since it is configured to be provided, there is an effect that a flaw or a detection point on the surface to be inspected can be efficiently detected without requiring a manual inspection work including a grindstone, and labor saving and stable inspection can be performed.

According to the seventeenth aspect of the present invention, since the image data processing means is not mounted on the movable arm and is provided non-movably separately from the optical system, the image data processing means moves the movable arm. There is an effect that reliability can be improved without being adversely affected by vibration and the like.

[Brief description of the drawings]

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

FIG. 2 is a partial configuration diagram showing a surface inspection device according to a second embodiment of the present invention.

FIG. 3 is a plan view showing a configuration of a filter element used in a surface inspection device according to a third embodiment of the present invention.

FIG. 4 is an explanatory diagram showing optical arrangement positions of an imaging lens and a filter element used in a surface inspection device according to a third embodiment of the present invention.

FIG. 5 is a block diagram showing a configuration of image data processing means in a surface inspection device according to a fourth embodiment of the present invention.

FIG. 6 is a partial configuration diagram showing a surface inspection device according to a fifth embodiment of the present invention.

FIG. 7 is a block diagram showing a configuration of image data processing means in a surface inspection device according to a sixth embodiment of the present invention.

FIG. 8 is a perspective view showing a configuration of a surface inspection device according to a seventh embodiment of the present invention.

[Explanation of symbols]

11 light sources (regular reflection light sources), 12 light sources (scatter reflection light sources), 13 imaging lenses, 14 beam splitters (separation means), 15a, 15b, 77a to 77d imaging elements, 21 light sources, 23 half mirrors (splitting means) Two
4, 76a, 76b filter element, 60, 80 image data processing means, 62a, 62b luminance average value measuring means, 63a, 63b variable amplification factor amplifier (amplification factor variable amplification means), 84 image compression circuit (one series of image processing Circuit), 85 local image processing circuit (one series of image processing circuit), 86 local image processing circuit (other one series of image processing circuit), 91, 92 holding arm (movable arm), 92
a grindstone mounting head (polishing part), 93 drive mechanism, 94
Image processing unit.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yasuo Kushida 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Japan Steel Pipe Co., Ltd. (72) Kozo Maeda 1-2-1 Marunouchi, Chiyoda-ku, Tokyo Main Steel Pipe Co., Ltd.

Claims (17)

[Claims] 1. A surface inspection apparatus for imaging a surface to be inspected and detecting a flaw or a point to be detected on the surface to be inspected, wherein a light reflection angle is equal to a prospective angle when the surface to be inspected is imaged. And a light source for specular reflection arranged in the direction of the first wavelength for irradiating light of a first wavelength, and a first direction in which the irradiation angle of the light is arranged in a scattering reflection direction different from the perspective angle when the surface to be inspected is imaged. A light source for scattering reflection for irradiating light of a second wavelength different from the wavelength, and light of the different wavelengths captured by the imaging optical system coaxial from the prospective angle position oblique to the surface to be inspected for each wavelength. Separation means for separating, an image pickup element on which an image of the surface to be inspected is formed by the light having different wavelengths separated by the separation means, and the image pickup element picked up for each light having the different wavelength. Processing the image data of the surface to be inspected An image data processing means for detecting a flaw or a detected point on the surface to be inspected. 2. The surface inspection apparatus according to claim 1, wherein the image data processing means obtains differential image data of the image data of the surface to be inspected captured for each different wavelength. 3. A surface inspection apparatus for imaging a surface to be inspected and detecting a flaw or a detected point on the surface to be inspected, wherein a light source for irradiating the surface to be inspected with a light source oblique to the surface to be inspected. Dividing means for dividing the light taken in from the expected angular position, a plurality of image pickup elements on which images of the surface to be inspected are formed based on the respective light divided by the dividing means, and A smoothed image smoothed in the noise direction is formed on one of the image pickup elements of the image pickup element, which is a noise component when a flaw is detected and which is a linear or striped flaw in a certain direction of the surface to be inspected. From a filter element provided in the image forming optical path of the image pickup device for forming an image, and from the image pickup device on which the smoothed image is formed for the same visual field as the visual field from which the smoothed smoothed image is obtained. The obtained image data and the filter element Performs arithmetic processing with the image data of the non-smoothed image obtained by the image pickup device not through,
An image data processing unit for detecting a flaw having a shape different from that of the noise component on the surface to be inspected. 4. The surface inspection apparatus according to claim 3, wherein the filter element is a one-dimensional low-pass filter including a one-dimensional grating or a cylindrical lens. 5. The arithmetic processing performed by the image data processing unit to detect a flaw having a shape different from the noise component of the surface to be inspected is performed on the image data of the non-smoothed image obtained by the image pickup element not passing through the filter element. The surface inspection apparatus according to claim 3 or 4, wherein the subtraction process is performed on image data of a smoothed image obtained by an image pickup device via the filter element. 6. The filter element is made of a light transmissive scattering medium having a scattering property only in the radiation direction centered on one point, and is arranged in the image forming optical path of the imaging lens, and the center position of the scattering is A filter element disposed in a plane including the optical axis of the image pickup lens and perpendicular to the surface to be inspected, and on a line of a principal ray passing through the center of the image pickup lens and parallel to the surface to be inspected. The surface inspection apparatus according to claim 3, wherein 7. The surface inspection apparatus according to claim 6, wherein the filter element is arranged with its surface perpendicular to the chief ray. 8. The arithmetic processing performed by the image data processing means for detecting a flaw having a shape different from the noise component of the surface to be inspected is performed on the image data of the non-smoothed image obtained by the image pickup element not passing through the filter element. 8. The subtraction process of the image data of the smoothed image obtained by the image pickup device via the filter device, according to claim 6 or 7.
The surface inspection apparatus according to claim 1. 9. The filter element according to claim 6, wherein concavity and convexity on a concentric circle are formed on the surface of the filter element.
The surface inspection apparatus according to claim 1. 10. The image data processing means, a brightness average value measuring means for measuring a brightness average value of the smoothed image and the non-smoothed image, and the smoothed image and the non-smooth image measured by the brightness average value measuring means. Amplification that adjusts the amplification degree of the image output of the smoothed image and the non-smoothed image for equalizing the brightness average value of the smoothed image and the non-smoothed image based on the brightness average value of the smoothed image 10. The surface inspection apparatus according to claim 3, further comprising variable rate amplification means. 11. A surface inspection apparatus for imaging a surface to be inspected and detecting a flaw or a point to be detected on the surface to be inspected, which is coaxial with the surface to be inspected through an imaging lens from an oblique angle position. Separation means for separating light of different wavelengths captured by the imaging optical system, dividing means for dividing light amounts of different wavelengths separated by the separation means, and the different wavelengths divided by the dividing means Defect detection on a pair of image pickup devices provided for each wavelength at which an image of the surface to be inspected is formed based on the light of each of the images, and on one of the pair of image pickup devices. Provided in the image forming optical path of the image pickup device for forming a smoothed image smoothed in the noise direction on a linear or striped flaw in a certain direction on the surface to be inspected, which becomes a noise component at the time of Filter element and light A specular reflection light source having an irradiation angle arranged in a direction of specular reflection equal to the prospective angle for imaging the surface to be inspected and irradiating light of one of the different wavelengths, and an irradiation angle of light indicates the surface to be inspected. Regarding the same field of view as the scatter reflection light source that is arranged in the direction of scatter reflection different from the angle of view to be imaged and irradiates light of a wavelength different from the one wavelength, and the field of view from which the smoothed image is obtained. The image data obtained from the image pickup device on which the smoothed image is formed and the image data of the non-smoothed image obtained by the image pickup device that does not pass through the filter device are operated to perform the calculation on the surface to be inspected. A surface inspection apparatus, comprising: an image data processing means for detecting a flaw having a shape different from that of a noise component. 12. The filter element is made of a light-transmissive scattering medium having a scattering property only in the radiation direction with one point as the center, is arranged in the image forming optical path of the imaging lens, and the center position of the scattering is A filter element arranged in a plane that includes the optical axis of the imaging lens and is perpendicular to the surface to be inspected and that is located on a line of a principal ray that passes through the center of the imaging lens and is parallel to the surface to be inspected, or The surface inspection apparatus according to claim 11, further comprising a filter element whose surface is arranged perpendicular to the chief ray. 13. An image data processing means, a brightness average value measuring means for measuring a brightness average value of a smoothed image and a non-smoothed image, and the smoothed image and the non-smooth image measured by the brightness average value measuring means. Amplification that adjusts the amplification degree of the image output of the smoothed image and the non-smoothed image for equalizing the brightness average value of the smoothed image and the non-smoothed image based on the brightness average value of the smoothed image 13. The surface inspection apparatus according to claim 11 or 12, further comprising variable rate amplification means. 14. The image data processing means obtains the difference calculation result between the smoothed image and the non-smoothed image obtained based on the regular reflection light source and the scattered reflection light source for the same visual field. 14. The difference calculation result between the smoothed image and the non-smoothed image is obtained, and the difference calculation is further performed between the difference calculation results.
The surface inspection apparatus according to claim 1. 15. The image data processing means comprises at least two series of image processing circuits for detecting a flaw or a detected point on a surface to be inspected, and one series of image processing circuits among the image processing circuits. Creates an image in which the average value of the intensity values of all pixels of a predetermined number of adjacent pixels of the original image is used as a new intensity value and compressed into one pixel, and image processing and the inspection are performed based on the compressed image. A surface flaw is detected, and another series of image processing circuits in the image processing circuit sequentially performs local image processing and detection of flaws on the surface to be inspected for each set of adjacent fixed number of pixels. The surface inspection apparatus according to any one of claims 1 to 14, characterized in that 16. A polishing part for sweep-polishing a surface to be inspected in a predetermined direction at a predetermined pressure by a predetermined amount and an optical system having at least a light source, an imaging lens and an image pickup element for the surface to be inspected are the same arm tip or It is characterized in that it comprises a movable arm attached to each of different arm tips, and a drive mechanism for moving the movable arm to move the polishing section and the optical system on the surface to be inspected. The surface inspection apparatus according to claim 15. 17. The surface inspection apparatus according to claim 16, wherein the image data processing means is not attached to the movable arm and is non-movably provided separately from the optical system.