JP2010025652A - Surface flaw inspection device - Google Patents

Abstract

[PROBLEMS] To detect, in real time, a minute uneven surface or color tone surface that can obtain a luminance change only at a predetermined light receiving angle with a simple configuration, and even if the belt is a shape wound around a roll, Provided is a wrinkle inspection device capable of recognizing edges appropriately and accurately.
Two-dimensional imaging for imaging a two-dimensional irradiation area LA on the surface of a band-like body that is irradiated with a band-like light L1 on the surface of the band-like body 1 that moves in a shape wound around a roll 2 in opposition to the incidence of the band-like light. The two-dimensional imaging apparatus includes an apparatus 20, and conveys the image signal of only the reflected light specified at two or more different light receiving angles β among the reflected light from the irradiation area of the belt. Generated by including an image processing device 32 that synthesizes image signals obtained from pixel rows partially read out simultaneously in synchronization with the velocity in the longitudinal direction of the strip, and an edge calculation device 31 that calculates edge positions from the image rows. Real-time defect detection with multiple light receiving angles according to the defect.
[Selection] Figure 1

Description

  The present invention relates to a wrinkle inspection device for the surface of a belt-like body such as a metal plate, and more particularly to a technique suitable for a wrinkle inspection device that uses a photographed image to inspect various wrinkles on the surface of a belt-like body.

  In the manufacturing process of strips such as steel plates that are one of the metal plates, defects that may impair the quality of the product are discovered early in the manufacturing stage, and the manufacturing conditions of the manufacturing process or the upper process are changed. It is necessary to prevent the occurrence of defects in subsequent products. For this purpose, for example, the inspection of the flaw is performed while moving the steel plate in the production line. Numerous inspection methods, such as electromagnetic and optical methods, have been developed as inspection methods for wrinkles. In particular, optical inspection methods can detect wrinkles on the surface without touching the steel sheet, and the wrinkle image is fast and easy. It is widely used to obtain

  The optical inspection method illuminates a portion to be inspected on a surface of a steel plate or the like to be passed, and based on an image signal obtained by continuously photographing with an imaging device such as a CCD camera,疵 is detected. In general, in such an optical surface defect inspection method, in order to perform bright-field imaging, there is no or little difference (about 0 ° to 5 °) between the incident angle of the illumination on the steel plate and the reflection angle. A regular reflection optical system for imaging, and a scattering reflection optical system for imaging in the range (20 ° to 70 °) where the angle difference between the incident angle and the reflection angle of the illumination on the steel plate is large in order to perform dark field imaging (hereinafter, respectively) In many cases, two systems of optical systems (referred to as “regular reflection optical system” or “diffuse reflection optical system”) are used. It is known that the regular reflection optical system is effective for detecting relatively large uneven ridges on the surface, and the scattering reflection optical system is effective for detecting colored foreign matters and dirt defects on the surface of the steel sheet.

  However, in recent years, from the viewpoint of implementing quality inspections at the time of shipment of products such as steel sheets and early prevention of wrinkles by early detection of wrinkles, compared to the formation that is the normal part of the surface of steel sheets, It is becoming increasingly important to detect wrinkles with slight differences in color and unevenness. In the surface inspection method having two systems of specular reflection optical system and irregular reflection optical system, the imaging device is fixed, that is, the light receiving angle of the imaging device is uniquely fixed within the light receiving angle range that satisfies the above two systems of optical systems. Therefore, there is a problem that it is difficult to detect wrinkles with slight differences in color tone and unevenness in imaging at a fixed light receiving angle. For example, in the case of minute uneven ridges such as pressing rods, and dirt that adheres thinly to the steel plate surface, a certain light receiving angle depends on the slight irregular reflection that occurs on the ridge surface, the angle dependence of the reflectance, or the surface properties of the texture. In some cases, the luminance change can only be obtained, and the detection becomes difficult.

  Therefore, as a device for inspecting surface defects on a steel plate or the like by changing the light receiving angle of the imaging device, the light receiving unit of the two-dimensional CCD camera is used as a pixel array of a two-dimensional CCD element as in the technique disclosed in Patent Document 1. Are arranged opposite to a flat steel plate so that the scanning direction substantially coincides with the width direction of the steel plate, and is obtained by scanning the pixel row at two or more successive times, and is long in the width direction of the steel plate. An apparatus for synthesizing two or more images of a specific portion to create inspection images with different light receiving angles is known.

JP 2005-274325 A JP 2002-181719 A JP 2006-292593 A

However, the above prior art has the following problems.
In the technique disclosed in Patent Document 1, a specific portion that is long in the width direction of the steel sheet moves on the production line by conveyance. This utilizes the fact that the light receiving angle of a certain imaging device changes. A plurality of images taken at a plurality of light receiving angles, respectively, taken with a two-dimensional CCD camera so that an image including a specific portion of a steel plate overlaps in an imaging region on a production line taken with a two-dimensional CCD camera. Combine the images of. Accordingly, in order to obtain two or more different steel plate images having a plurality of predetermined light receiving angles set in advance, the specific portion must be photographed at least twice at a predetermined light receiving angle in the photographing region. is there. In other words, it is always necessary to capture a two-dimensional image including a specific portion with two or more imaging times. For this reason, efficient image photography cannot be performed. In addition, when using a two-dimensional CCD having a large number of pixels in order to obtain a light receiving angle with a large amount of change, it is necessary to further increase the frame rate of the two-dimensional CCD camera, and it is applied to a line that carries at high speed. Have difficulty. Furthermore, when performing the process of synthesizing the above image with the image processing apparatus in the subsequent process from the two-dimensional image data of the frame unit obtained by photographing the specific part of the steel plate at least twice in the imaging region, The image data including the image data of the unnecessary light reception angle is transmitted to the image processing apparatus in the subsequent process, and only the image data (for one pixel column) of the specific portion imaged at the predetermined light reception angle is image data for each frame. Must be extracted from. For this reason, processing of two-dimensional image data in units of frames necessitates data transmission time and image composition processing time. Therefore, in the technique disclosed in Patent Document 1, there is a problem that it is difficult to detect real-time wrinkles when a steel plate is passed, and in addition, there is a problem that an apparatus cost for high-speed image processing increases. . Furthermore, it only assumes wrinkle inspection when the shape of the steel plate is flat, and the light receiving angle varies due to fluctuations in the pass line of the steel plate being conveyed and waviness of the steel plate (large uneven shape of the steel plate itself). For this reason, there has been a problem that stable wrinkle detection cannot be performed.

  In order to suppress fluctuations in the pass line and the undulation of the steel sheet, the above problem can be solved if the steel sheet is configured to perform a wrinkle inspection in a shape wound around the transport roll so that tension is applied to the steel sheet. However, since the surface of the steel plate and the surface of the transport roll are photographed at the same time, it is necessary to detect the left and right edge positions of the steel plate, the area between the left and right edges is recognized as a steel plate, and the left and right edge detection positions are detected. The necessity of recognizing the outside as a transport roll was not considered at all.

  When performing wrinkle detection from an image captured in a state where the steel plate is wound around the transport roll, a method of distinguishing the steel plate from the transport roll is performed. This is because, by specifying the position of wrinkles on the steel plate and picking up all parts other than the steel plate (the surface of the transport roll) as wrinkle candidates, the processing of the computer exceeds the allowable amount, or the processing is unnecessary. This is to solve the situation where the wrinkle generation position information becomes inaccurate. As a method of distinguishing between the transport roll and the steel plate, the outside of the left and right edge positions is recognized as the transport roll based on the image processing of the captured image or the left and right edge position information obtained from the separately provided edge detector. The method of reflecting in an image has generally been performed.

  As a method for detecting the edge position based on the image signal obtained by photographing the surface of the steel plate, for example, there is a technique disclosed in Patent Document 2, and the edge of the steel plate is appropriately detected even if the luminance varies greatly within one steel plate. For the purpose of recognizing the threshold, the threshold value for performing edge detection based on the luminance information within one scan or several scans of the steel plate surface image composed of data obtained by scanning a plurality of steel plate width directions is set as the luminance average in the steel plate width direction. By changing according to the value, the edge detection threshold is calculated using the maximum or minimum value after passing the low-pass filter through the luminance information for one scan after detecting the steel plate edge according to the state of the steel plate Thus, a method of detecting a steel plate edge according to the brightness of the steel plate is performed.

  However, in the technique disclosed in Patent Document 2, when the difference between the luminance information on the steel plate surface and the luminance information on the conveyance roll surface is calculated, the edge of the steel plate can be detected. Steel, rubber, urethane, etc. are used as the material, and the surface of the transport roll varies depending on the surface treatment such as thermal spraying and polishing treatment such as buffing from the viewpoint of durability and prevention of slipping on the steel plate. Since the surface properties (surface roughness, color tone) are high, the brightness of the steel plate and the brightness of the transport roll are equivalent on the inspection image taken at a predetermined light receiving angle set for the purpose of wrinkle detection. There was a problem that an edge could not be detected.

  In addition, as another method for obtaining edge position information, an edge detector is separately installed, and from the left and right edge position information of the obtained steel plate, the outside of the left and right edge positions is recognized as a transport roll. It may be reflected in the captured image. As the edge detector, a method is generally used in which projected light from the rear surface of the steel plate is detected by a one-dimensional line camera or the like, and the edge position is calculated from the amount of received light. In this case, it is difficult to install an edge detector adjacent to the flaw inspection position due to restrictions on the arrangement of equipment on the production line, and it is necessary to install the edge detector at some distance from the flaw inspection apparatus. Often not. Therefore, when the steel plate wound around the roll is meandering, if there is a time lag of the passing plate between the position of the edge detector and the position of the wrinkle inspection position, the edge position obtained by the edge detector There is a problem that the edge position on the inspection image of the eyelid inspection apparatus does not completely match. In addition, since a separate edge detector is installed, there is a problem that the wrinkle inspection device is expensive.

  In view of the above-described problems of the prior art, the object of the present invention is to reduce the amount of scattered / reflected light in the formation, which is a normal part of the band, and to detect slight irregular reflection differences and reflectivity due to minute wrinkles on the surface of the band Luminance modulation at a light reception angle suitable for the angle dependence of the image can be efficiently imaged at a plurality of arbitrarily set light reception angles, and image detection can be performed at high speed without using a plurality of imaging devices. A device for inspecting the wrinkle of a belt-like body at a lower cost than in the past, with a simpler device arrangement than before, and even when the belt-like body is wound around a roll, the edge of the belt-like body can be recognized appropriately and accurately. Is to provide.

The surface flaw inspection apparatus of the present invention that solves the above-mentioned problems irradiates the band-shaped light on the entire width direction of the surface of the band-shaped body at the portion of the band-shaped body that is conveyed by the roll and wound around the roll. A surface wrinkle inspection device that images the reflected light of the band light from the band light irradiation region, which is a region irradiated with light, and inspects wrinkles on the surface of the band,
An illumination device that irradiates a band-shaped light that converges in accordance with a roll diameter so that a vertical incident angle of the band-shaped light with respect to the band-shaped body is equal to a predetermined value set in advance at all points in the band-shaped light irradiation region. When,
A plurality of partial regions that are arranged opposite to the illumination device across the band-shaped light irradiation region and that are different in position in the moving direction of the band-shaped body in the band-shaped light irradiation region in synchronization with the movement of the band-shaped body. A partially readable two-dimensional imaging device that captures images at a plurality of different vertical reflection angles and outputs a plurality of column unit images;
Luminance information from at least one column unit image of the plurality of column unit images while a frame image is configured from each of at least two column unit images of the plurality of column unit images. Using an edge calculating device for calculating the edge position of the strip,
A wrinkle image processing device that performs image processing on the frame image to detect wrinkles on the surface of the strip;
It is characterized by providing.

The two-dimensional imaging device includes a two-dimensional CMOS camera having a two-dimensional pixel array composed of a plurality of CMOS image sensors, and outputs the column unit image of an arbitrary pixel column from the pixel array according to an instruction from a control device. Is what
The control device designates a plurality of pixel columns of the two-dimensional CMOS camera to the two-dimensional imaging device in order to image the plurality of partial regions corresponding to the plurality of vertical reflection angles set in advance. And further arranging and synthesizing at least two column unit images of the plurality of column unit images corresponding to the plurality of partial regions input from the two-dimensional imaging device, Constructing a frame image obtained by imaging the belt-shaped light irradiation region by each of the vertical reflection angle represented by each of the above column-unit images,
The edge calculation device uses the luminance information from one or more column unit images of the plurality of column unit images while the frame images of the vertical reflection angles are formed, and Calculate the edge position,
It is characterized by that.

Further, the control device is different from the partial areas respectively corresponding to the at least two or more column-unit images used to configure the frame image, and the image brightness of the roll surface and the image of the belt-like body surface The pixel of the two-dimensional CMOS camera is used to capture a partial region corresponding to the vertical reflection angle at which the difference from the luminance is greater than or equal to a preset edge luminance difference threshold value, at least once during the formation of the frame image. Specify the column and instruct the 2D imaging device;
The two-dimensional imaging device outputs a column unit image corresponding to a partial region corresponding to the vertical reflection angle to the edge calculation device,
The edge calculation device may calculate the edge position of the strip from the luminance information of the column unit image input from the secondary imaging device.

In addition, the control device is configured to use the at least two column-unit images used to form the frame image at a time point when a front end portion immediately after the connecting portion of the strips that are connected to each other is imaged. In order to photograph a plurality of partial areas respectively corresponding to a plurality of vertical reflection angles, which are different from the partial areas corresponding respectively to the two-dimensional CMOS camera, a pixel column of the two-dimensional CMOS camera is designated and a two-dimensional imaging apparatus is instructed. ,
The two-dimensional imaging device outputs a plurality of column unit images respectively corresponding to a plurality of partial regions respectively corresponding to the plurality of vertical reflection angles to the edge calculation device;
The edge calculation device is configured such that a difference between an image luminance of the roll surface and an image luminance of the belt-like body surface is set as a predetermined edge luminance difference from the plurality of column unit images input from the secondary imaging device. You may determine the vertical direction reflection angle which becomes more than a threshold value.

In addition, the control device is configured to detect the band-like body according to width information of the band-like body input from a host computer at the time when the front end portion immediately after the connecting portion of the band-like bodies that are connected to each other is imaged. In order to image a predetermined two-dimensional region in the vicinity of the edge, set pixels in predetermined rows and columns and instruct the two-dimensional imaging device;
The two-dimensional imaging device outputs a predetermined two-dimensional region image near the edge to the edge calculation device,
The edge calculation device is configured such that a difference between the image luminance of the roll surface and the image luminance of the band-like surface is a preset edge luminance difference threshold value from the two-dimensional region image input from the secondary imaging device. The vertical reflection angle as described above may be determined.

Further, the surface flaw inspection method of the present invention irradiates the band-like light to the entire width direction of the surface of the band-like body at the portion of the band-like body conveyed by the roll and wound around the roll. A surface wrinkle inspection method for inspecting wrinkles on the surface of the belt-like body by imaging the reflected light of the belt-like light from the belt-shaped light irradiation region,
With the illuminating device, the band-shaped light that converges in accordance with the roll diameter is adjusted so that the vertical incident angle of the band-shaped light with respect to the band-shaped body is equal to a predetermined value set in advance at all points of the band-shaped light irradiation region. Irradiating step;
Movement of the band-like body within the band-like light irradiation area is performed in synchronization with the movement of the band-like body by a two-dimensional imaging device that is arranged opposite to the illumination device with the band-like light irradiation area interposed therebetween and capable of partial reading. Imaging a plurality of partial regions having different positions in the direction at a plurality of different vertical reflection angles, and outputting a plurality of column unit images;
While the frame image is constructed from each of at least two or more column unit images of the plurality of column unit images by the edge calculation device, at least one or more column units of the plurality of column unit images Calculating the edge position of the strip using luminance information from the image;
A step of image-processing the frame image by a heel image processing device to detect a fold on the surface of the strip;
It is characterized by including.

Furthermore, the computer program of the present invention is
In the portion of the belt-like body conveyed by the roll, the belt-like light is irradiated on the entire surface in the width direction of the surface of the belt-like body, and the belt-like light is irradiated from the belt-like light irradiation region. A computer that controls a surface wrinkle inspection device having an illumination device, a two-dimensional imaging device, an edge calculation device, and a wrinkle image processing device for imaging reflected light of the band light and inspecting wrinkles on the surface of the band. ,
Strip light that converges in accordance with the roll diameter so that the vertical incident angle of the strip light on the strip is equal to a predetermined value at all points in the strip light irradiation region by the illumination device. Irradiating with
The two-dimensional imaging device that is disposed opposite to the illumination device with the band-shaped light irradiation region interposed therebetween and is capable of partially reading out, in synchronization with the movement of the band-shaped body, of the band-shaped light irradiation region. A process of imaging a plurality of partial areas with different positions in the moving direction at a plurality of different vertical reflection angles and outputting a plurality of column unit images;
While the frame image is formed from each of at least two or more column unit images of the plurality of column unit images by the edge calculation device, at least one or more columns of the plurality of column unit images. Using the luminance information from the unit image, a process for calculating the edge position of the strip,
Processing to detect wrinkles on the surface of the strip by performing image processing on the frame image by the wrinkle image processing device;
Is executed.

  As described above, according to the present invention, the surface of the strip can be inspected at a plurality of light receiving angles at the same time even when the strip is wound around the roll without using a plurality of imaging means. Since multiple light receiving angles can be selected according to the generated wrinkles, real-time detection of wrinkles that can only change the brightness at a predetermined light receiving angle is possible, and an edge detector is added. It is possible to recognize the edge of the belt-like body properly, prevent the function of the wrinkle detection device from being deteriorated, and further reduce the size and cost of the device, so that the wrinkle inspection device can be easily introduced. become.

  Exemplary embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In addition, in this specification and drawing, about the component which has the substantially same function structure, duplication description is abbreviate | omitted by attaching | subjecting the same code | symbol.

<Related technologies>
Prior to describing the embodiments of the present invention, the related art of the present invention will be described.
The surface defect inspection apparatus according to the related art is different from the above-described conventional technique in that the surface of a steel plate that moves in a flat shape is partially read out in a two-dimensional irradiation area irradiated with the planar light and opposed to the planar light incidence. A pixel in which the image signal of only the reflected light specified by two or more different light receiving angles in the reflected light from the irradiation area is partially read out in synchronization with the transport speed of the steel plate with a possible two-dimensional CMOS camera By synthesizing and arranging the image signals obtained from the columns in the longitudinal direction of the steel plate, inspection images at two or more light receiving angles are simultaneously created in real time.

  The surface defect inspection apparatus according to this related technology includes an imaging device including a two-dimensional CMOS camera having a two-dimensional image array including a plurality of partially readable CMOS imaging elements, and has a planar shape extending in the width direction of the steel plate. Inspection images can be obtained at a plurality of light receiving angles at the same time from within the planar light irradiation region irradiated on the light irradiation region. Therefore, by selecting a plurality of light receiving angles arbitrarily according to the generated wrinkles, real-time detection of wrinkles that can obtain a change in luminance only at a predetermined light receiving angle is supported. However, it is only assumed that wrinkle inspection is performed when the shape of the steel plate is flat, and the light receiving angle depends on fluctuations in the pass line of the steel plate being transported and the waviness of the steel plate (large uneven shape of the steel plate itself). Due to fluctuations, there was a risk that stable soot detection could not be performed.

  Even in this related technology, if the steel sheet is configured to perform the wrinkle inspection while being wound around the transport roll, the tension is applied to the steel sheet, so that fluctuations in the pass line and undulation of the steel sheet can be suppressed and the advantages can be utilized. be able to. However, as in the prior art, it is necessary to detect the left and right edge positions of the steel sheet, and the area between the left and right edges is recognized as a steel sheet, and the outside of the left and right edge detection positions is still recognized as a transport roll. difficult.

  As a result of earnest research on such improvements of the related art, the present inventor has found that a plurality of strips are wound around a roll without using a plurality of imaging means at the same time. The surface of the band-shaped body can be inspected at a certain light receiving angle, and a plurality of light receiving angles can be selected according to the generated wrinkles. In addition to being able to recognize the edge of the belt-like body appropriately without adding an edge detector, it is possible to prevent the function of the wrinkle detection device from being degraded, and further downsizing and cost reduction of the device. Since this is possible, the present inventors have arrived at the present invention, which facilitates the introduction of wrinkle inspection. Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

<Embodiment>
FIG. 1 shows an example of an embodiment of the present invention. A strip of an object to be inspected is a plurality of steel plates in which the rear end and the front end of each steel plate are connected by welding at welding points. FIG. 1 is a schematic configuration diagram of a surface flaw inspection apparatus disposed in a steel plate production line (hereinafter referred to as “steel plate line”) that is processed while the steel plate moves while being wound around a roll.

  The surface defect inspection apparatus includes an illumination device 10 that illuminates an imaging region (also referred to as a “band-like light irradiation region”) LA on the surface of the steel plate 1, and a two-dimensional imaging device 20 that images the imaging region and outputs image data. A control device 30 that controls the two-dimensional imaging device 20, an edge calculation device 31 that calculates an edge of the steel plate 1, and a heel image processing device 32 that performs image processing on the image data to detect wrinkles on the surface of the steel plate 1. And an operator wrinkle display device 33 for displaying the detected wrinkle information on the screen. Furthermore, a sensor such as a rotary encoder for detecting the movement of the steel sheet in the steel plate line, by closely contacting and rotating the roll 2 on the back surface of the steel sheet 1 and outputting a pulse signal for each set rotation angle of the roll 2 ( Hereinafter, it is referred to as “PLG40”). This surface flaw inspection apparatus measures the portion where the steel plate 1 is wound around the roll 2, and can inspect with little error due to pass line fluctuation.

(Lighting device 10)
The illuminating device 10 includes a light source 11 formed of a fluorescent lamp or an incandescent lamp, an optical fiber bundle 12, an input end 13 that guides light emitted from the light source into the optical fiber, and an output end 14 that emits light from the optical fiber. ing. In the optical fiber bundle 12, a large number of optical fibers are aligned, the light source 11 is close to the input end 13, and the strip-shaped light L <b> 1 is emitted from the output end 14 arranged in parallel with the width direction of the steel plate 1.

  FIG. 2 is a plan view of the steel plate surface on the steel plate line as viewed from above, and shows a planar arrangement of the illumination device 10, the strip-shaped light irradiation surface LA, and the two-dimensional imaging device 20. FIG. 3 is a side view of the steel plate line viewed from the side, that is, from the roll axis direction, and shows the arrangement of the side surfaces of the illumination device 10, the strip-shaped light irradiation region LA, and the two-dimensional imaging device 20.

  In addition, the vertical direction of the steel plate surface that is wound around the roll and curved in the present application refers to the vertical direction of the tangential plane. As shown in FIG. 3, the band-like light L1 is a rod lens or cylindrical lens (not shown) provided at the output end 14, and the angle α (vertical incident angle) formed with the vertical direction of the steel plate surface of the steel plate 1 is The light is converged according to the roll diameter so as to be equal at each point of the band-shaped light irradiation area LA, and the band-shaped light irradiation area LA is irradiated at a vertical incident angle α of about 45 to 70 °. The band-shaped light L1 is irradiated with uniform illuminance over the entire width of the band-shaped light irradiation area LA so that the irradiation width in the moving direction of the steel plate 1 satisfies the imaging range of the two-dimensional imaging device 20. For example, the illuminating device 10 is an illuminating device at the output end of a fiber bundle using one 180 W halogen lamp as a light source. The illuminating device 10 is set to irradiate the steel plate surface with a vertical incident angle α of 45 degrees. The upper strip-shaped light irradiation area LA is 1700 mm in the width direction and 70 mm in the length direction. Although the distance from the output end 14 of the optical fiber bundle 12 to the strip light irradiation area LA on the steel plate surface of the strip light L1 is determined by the apparatus configuration of the steel plate line, it is about 200 to 400 mm in the present embodiment. The lighting device 10 may use other belt-like light sources other than those described above, such as a commercially available LED laser light lighting device.

(Two-dimensional imaging device 20)
The optical axis of the two-dimensional imaging device 20 that images the strip-shaped light irradiation area LA on the steel plate has an angle β (vertical reflection angle) with the vertical direction of the steel plate surface of the steel plate 1 of, for example, 45 degrees, and the vertical direction. The two-dimensional imaging device 20 is installed so as to be equal to the incident angle α (see FIG. 3).

  The two-dimensional imaging device 20 is located at a position facing the illumination device 10 across the band-shaped light irradiation area LA, and one or a plurality of the two-dimensional imaging devices 20 are usually arranged in parallel in the width direction of the steel plate 1. The number of the two-dimensional imaging devices 20 is determined according to the required resolution of how much wrinkles are detected based on the inspection width of the steel plate 1 and the number of pixels in the horizontal direction of the imaging element. Normally, there are a plurality of types of steel plates 1 through which the steel plate line passes, and the widths of each are about 1 m to 3 m, and accordingly, three or four imaging devices are usually arranged in parallel. Note that the distance from the two-dimensional imaging device 20 to the belt-shaped light irradiation area LA on the steel plate surface of the strip-shaped light L1 is the inspection width of the steel plate 1, the viewing angle of the imaging device 20, the required resolution, and the like. It is determined by the arrangement of the apparatus and is usually about 300 to 1200 mm. For example, when the width of the steel plate is 1500 mm and the two-dimensional imaging device uses a camera having an imaging element having 2352 horizontal pixels and 200 vertical pixels, the plate width direction is 0.35 mm pixel size, and the line size pixel size is 0. To obtain an image of 35 mm, if the optical conditions are set so that the width direction field of view of one camera is 820 mm, the size of the field of view in the camera width direction is 1640 mm with two cameras, and an image of the entire plate width can be obtained. Can do.

  The two-dimensional imaging device 20 includes a two-dimensional pixel array in which a plurality of CMOS (Complementary Metal Oxide Semiconductor) imaging elements 22 are two-dimensionally arranged (rows and columns) on the light receiving unit 21 as schematically shown in FIG. The optical axis is directed so that the width direction of the steel plate 1 is parallel to the scanning direction of the image sensor and the moving direction of the steel plate 1 is perpendicular to the scanning direction of the image sensor. It has been. During one imaging operation, a plurality of different pixel columns (hereinafter referred to as “pixel columns”) are arbitrarily selected, and image signals of the pixel columns (hereinafter referred to as “column-unit images”) are partially Means for reading is provided.

  Therefore, the p-column unit image obtained from the p-th pixel column of the CMOS image sensor 22 and the q-column unit image obtained from the q-th pixel column of the CMOS image sensor 22 can be obtained during the same imaging operation. (Where p and q represent any two different column numbers of the CMOS image sensor 22).

  In the embodiment of the present invention, the band-shaped light converged in accordance with the roll diameter is reflected by the band-shaped light irradiation region LA so that the light is irradiated from the output end 14 of the lighting device 10 with the vertical incident angle α inclined. An image is formed on the light receiving unit 21 of the two-dimensional imaging device 20 and the strip light irradiation area LA is imaged. At this time, a plurality of partial areas having different positions in the moving direction of the band-like body in the band-like light irradiation area LA are imaged by the two-dimensional imaging device 20 at a plurality of different vertical direction reflection angles. More specifically, as shown in FIGS. 2 and 3, the reflected light having a constant vertical reflection angle βp is always two-dimensionally from the partial region Lp long in the width direction of the steel plate 1 on the strip-shaped light irradiation region LA. Light is received at the p-th row of the CMOS image sensor 22 of the light receiving unit 21 of the imaging device 20. Similarly, reflected light having a constant vertical reflection angle βq is always received from the partial region Lq on the strip-shaped light irradiation region LA by the q-th column of the CMOS image sensor 22 of the light-receiving surface 21 of the two-dimensional imaging device 20. become. The correspondence between the partial areas Lp and Lq on the band-shaped light irradiation area LA and the p-row and q-column on the CMOS image sensor 22 is determined by imaging the band-shaped light irradiation area LA from the CMOS image sensor 22 in advance using the optical system. Obtain and calibrate the image. By the way, since the band-shaped light irradiation area LA forms an image on the light receiving unit 21 of the two-dimensional imaging device 20, the vertical reflection angle is always constant from the partial area Lp where the band-shaped light is incident at the vertical direction incident angle α. Since an image of one scanning line is incident at βp, if the pixel row of the CMOS image sensor is arbitrarily selected, the vertical reflection angle is always uniquely defined within the band-shaped light irradiation area LA. It is possible to select. Although the case where the partial areas Lp and Lq are imaged is described here, the number of the partial areas may be plural and may be three or more.

(Control device 30)
The control device 30 sets the line speed so that the pixel size in the steel plate line direction on one image picked up by the two-dimensional image pickup device 20 is equal to the length of the moving steel plate during the time of one image pickup operation. In response to the pulse signal output from the PLG 40, the two-dimensional imaging device 20 outputs an imaging drive signal for imaging once. Further, the control device 30 selects and sets a plurality of pixel columns of the CMOS image sensor 22 from which an image signal is read out by processing that will be described in detail later. A frame image is created by sequentially synthesizing each column unit image obtained from the two-dimensional imaging device 20 during one imaging operation in the longitudinal direction of the steel plate, and sequentially outputting the frame image processing device 32.

  FIG. 5 is an explanatory diagram for explaining an example of processing when two pixel columns (p-th column and q-th column) on the CMOS image sensor 22 are selected when the steel sheet 1 is inspected. FIG. 5A shows a column unit image (p column unit image or q column unit image) captured by the p-th pixel column and the q-th pixel column of the two-dimensional imaging device 20, each steel plate 1. The partial area (Lp or Lq), which is the upper imaging position, and the conveying direction of the steel sheet 1 are upward, the time axis is rightward, and each imaging time t, t + i, t + 2i (where i is required for imaging) A state of movement of the steel plate 1 in (time) is schematically shown. In the embodiment of the present invention, the imaging drive signal output from the control device 30 includes the length of the steel plate that the two-dimensional imaging device 20 moves during one imaging time, and the pixel size in the steel plate line direction on the image to be captured. As shown in FIG. 5 (b), each column unit image (p column unit images or q column unit images) obtained by sequential imaging operation is displayed at each imaging time. The frame image Ip obtained by combining the p-row unit images in the longitudinal direction of the steel plate and the frame image Iq obtained by combining the q-row unit images in the longitudinal direction of the steel plate can be created simply by arranging and synthesizing them sequentially.

  The selectable pixel columns of the column-unit image that can be obtained during the same imaging operation are the two p-th image columns and the q-th column corresponding to the two different vertical reflection angles βp and βq in the above. Although the case where an image sequence is used has been described, the number of pixel columns corresponding to a plurality of different vertical reflection angles β is not limited to two, and the number of image columns included in the light receiving unit 21 can be selected.

(Edge calculation device 31)
Next, in order to obtain a frame image used for wrinkle detection, an operation in which the edge calculation device 31 calculates an edge position when edge detection is possible from a captured column-unit image will be described. The control device 30 inputs the p-row unit image or the q-row unit image captured by the two-dimensional imaging device 20 to the edge calculation device 31 at least once during the creation of the frame image. The edge calculation device calculates a steel plate edge position by searching for a step between the roll surface luminance and the steel plate surface luminance (hereinafter referred to as “edge luminance difference”) from the luminance profile of the input p-row unit image or q-row unit image, The edge position is output to the image processing apparatus 32. Here, assuming that the luminance range of the column unit image is 0 to 255, the edge luminance difference threshold value Δy can be detected without mistake if the edge luminance difference threshold value Δy is, for example, 10 or more. .

  In order to calculate the edge position, the edge luminance difference of the column unit image may be searched by a known technique. For example, after removing high-frequency components from the column unit image through a low-pass filter, the difference between adjacent luminance values is sequentially obtained, the maximum difference is set as the edge luminance difference, and the position is calculated as the edge position. Alternatively, a position exceeding the edge luminance difference threshold value Δy may be searched for the first time from the roll surface of the row unit image, and the edge position may be used.

  In the embodiment of the present invention, since a plurality of column unit images can be selected to obtain a plurality of frame images used for wrinkle detection, an edge luminance difference is obtained from each selected column unit image. The edge luminance difference calculated from the column unit image is sequentially compared with the edge luminance difference threshold value Δy, the position of the edge luminance difference satisfying the condition equal to or larger than Δy is selected, and output to the heel image processing device 32 as edge position information. can do.

  As an example, a case where a steel plate is wound around a steel roll that has been subjected to a black baking coating will be described. FIG. 6A shows the luminance profile of the p-column unit image, and FIG. 6B shows the luminance profile of the q-column unit image. Here, the p-column unit image is a column-unit image when the pixel column of the CMOS image sensor 22 is selected so as to capture the reflected light with the vertical reflection angle satisfying the irregular reflection optical system, and the q-column unit image is This is a column-unit image when the pixel column of the CMOS image sensor 22 is selected so as to image the reflected light having a vertical reflection angle that satisfies the regular reflection optical system. Accordingly, FIG. 6A shows the luminance profile of the column-unit image captured by the irregular reflection optical system, and FIG. 6B shows the luminance profile of the column-unit image captured by the regular reflection optical system. In FIG. 6B, since the steel roll surface has the same surface roughness as the steel plate surface to be inspected, the brightness of the image captured by the regular reflection optical system is the same for the steel plate and the roll. That is, the edge luminance difference of the column-unit image captured by the regular reflection optical system does not exceed the edge luminance difference threshold value Δy, so that the edge position cannot be selected. However, in FIG. 6A, since there is a difference in color tone between the roll surface and the steel plate surface, the luminance difference appears remarkably in the luminance of the image captured by the irregular reflection optical system. That is, the edge luminance difference obtained from the p-row unit image is equal to or greater than the edge luminance difference threshold Δy, and the edge position can be easily determined. As described above, according to the embodiment of the present invention, the column unit images captured to obtain the frame image to be used have different vertical reflection angles, and therefore the column unit images having different brightness differences between the roll and the steel plate. Can be obtained, it is possible to select a column unit image having an edge luminance difference sufficient to select an edge position, and as a result, it is possible to accurately calculate edge position information.

  Next, the vertical reflection angle at which edge detection cannot be performed and edge positions can be calculated from the column unit images (for example, p column unit images and q column unit images) selected to obtain the frame image used for wrinkle detection A case where βe is known will be described. For example, it is not possible to obtain an edge luminance difference satisfying the edge luminance difference threshold Δy or more from each column-unit image selected and imaged to create a frame image necessary for wrinkle detection, and obtain an edge position. This is the case when you cannot. In such a case, the controller 30 captures the partial area Le corresponding to the vertical reflection angle βe that can obtain an edge luminance difference equal to or greater than the edge luminance difference threshold value Δy, in order to capture the e of the CMOS image sensor 22. Select and set the pixel column. Then, the edge calculation device 31 calculates the edge position from the e-row unit image output by the two-dimensional imaging device, and outputs it to the eyelid image processing device 31 as described above. Note that the number of e-row unit images input to the edge calculation device 31 by the control device 30 is the interval between creation of a plurality of frame images necessary for wrinkle inspection, that is, the frame images Ip and Iq are created in FIG. The number of times of input can be easily controlled using the imaging drive signal of the PLG 40. Further, the pixel column e set by the CMOS image sensor 22 may be determined in advance by examining the off-line experiment or when the line is stopped, corresponding to the roll surface and the type of steel plate. . Therefore, even when the edge cannot be detected from the column unit image selected to obtain the frame image used for wrinkle detection, it is possible to detect the edge with high accuracy from the column unit image that can be separately detected. .

  Further, a case where the vertical reflection angle βe capable of calculating the edge is detected online will be described. In the embodiment of the present invention, the plurality of steel plates of the object to be inspected are those in which the rear end and the front end of each steel plate are connected by welding at the welding point, and before and after the welding point, it is necessary to perform a flaw inspection. Since it is low, a plurality of column-unit images other than the plurality of column-unit images selected to obtain the frame image used for wrinkle detection at the top of the steel plate can be used to calculate the optimum edge position. What is necessary is just to select an image. Specifically, the control device 30 receives a signal (welding point detection signal) in which a welding point is detected by a welding point detection unit (not shown), and at the time when the area being imaged is switched to the steel plate top portion, In order to photograph a plurality of partial regions Lm corresponding to a plurality of vertical direction reflection angles βm different from the vertical direction reflection angle selected for haze detection, a plurality of pixel columns are set in the two-dimensional CMOS image sensor 22. . Then, the edge calculation device 31 corresponds to the vertical reflection angle βe that satisfies the edge luminance difference threshold Δy or more by sequentially calculating and comparing the edge luminance differences from the plurality of m-column unit images output by the two-dimensional imaging device. The obtained e-row unit image is obtained. In order to select the e column unit image, when sequentially comparing the edge luminance difference, a column unit image that first satisfies the edge luminance difference threshold value Δy may be selected, or a plurality of edge luminance difference threshold values may be selected. You may select the thing with the largest edge brightness | luminance difference from the row | line | column images which satisfy (DELTA) y or more. In this manner, the e-th pixel column of the two-dimensional CMOS image sensor 22 can be selected.

  Alternatively, in addition to the above-described welding point detection signal, when the steel plate width information is also input to the control device 30 from a host computer (not shown), at the time when the imaged area is switched to the steel plate head portion, The control device 30 instructs to set pixels in a predetermined rectangular area of the two-dimensional CMOS image sensor 22 in order to image a predetermined edge search area LE (FIG. 2) near the edge of the steel plate. Since the pixel row of the two-dimensional CMOS image sensor is uniquely determined at which position in the width direction of the steel plate is photographed when the two-dimensional CMOS camera is installed, the center of one side in the scanning direction of the rectangular area is As the pixels corresponding to the edge position coordinates calculated from the steel plate width information, the number of pixels on one side in the scanning direction of the rectangular region is set in consideration of the meandering amount called the steel plate walk amount. For example, in a normal steel plate line, the walk amount is about ± 50 mm. Therefore, when the pixel size in the plate width direction is 0.35 mm, 286 pixels (≈100 mm / 0.35 mm) are set. In addition, the length of one side perpendicular to the scanning direction of the rectangular area can be arbitrarily set up to the irradiation width in the moving direction of the steel plate in the band-shaped light irradiation area LA, but is usually set to about half the irradiation width in the moving direction. To do. Then, the edge calculation device 31 uses the image of the edge search region LE imaged and output by the two-dimensional imaging device to sequentially obtain the edge luminance difference for each column unit, and satisfies the edge luminance difference threshold Δy or more. By obtaining an e-row unit image corresponding to the direction reflection angle βe, a pixel row may be selected as the corresponding 2-dimensional CMOS image sensor 22e row. In this way, the size of the image to be handled can be reduced, so that it is possible to efficiently search for the column unit image necessary for calculating the optimum edge position. As described above, the surface flaw inspection apparatus according to the embodiment of the present invention includes the edge calculation device 31 as described above, so that the edge of the steel plate can be more accurately and easily used by using the captured column unit image or the like. Can be recognized. Therefore, it is possible to accurately recognize the edge without using a separate edge detector or the like that has been difficult to detect an accurate edge position due to restrictions on the arrangement of equipment on the production line, and the like. Since such a separate edge detector is not necessary, it is possible to reduce the manufacturing cost of the entire eyelid inspection apparatus.

(Examples of actions and effects)
As described above, in the embodiment of the present invention, the two-dimensional imaging device 20 reads out image signals of a plurality of predetermined different pixel columns selected by the control device 30 during one imaging operation. Therefore, if the control device 30 selects the p-th column of the CMOS image sensor 22 and the q-th column of the CMOS image sensor 22 in advance, the p-column of the vertical reflection angle βp is obtained by one imaging operation. A unit image and a q-row unit image having a vertical reflection angle βq can be obtained at the same time, and an optimum row-unit image for calculating the edge position can be obtained at the same time.

  The control device 30 can correspond to the type and surface properties of the steel plate 1 in advance and accurately capture the steel plate at any vertical reflection angle (determined uniquely by the pixel row read by the CMOS image sensor 22). A database (not shown) built in as a vertical reflection angle or a pixel row number for each type of the steel plate 1 by examining beforehand whether it can be detected or the edge position can be calculated by the edge calculation device 31 through experiments or the like. Register with. Then, when actually inspecting with the steel plate line, the vertical reflection angle suitable for the type and surface property of the steel plate to be inspected is determined based on the database, and the readout pixel column setting signal of the CMOS image sensor 22 is determined. Is output to the two-dimensional imaging device 20 to control imaging.

  Furthermore, as described above, the imaging operation is repeated by the imaging drive signal that is output from the control device 30 and synchronized with the pulse signal PLG corresponding to the movement of the steel plate 1, so that imaging is easily performed at the vertical reflection angle βp. The frame image (FIG. 5, Ip) and the frame image (FIG. 5, Iq) captured at the vertical reflection angle βq can be obtained continuously for the entire area in the longitudinal direction of the steel sheet. The above accurate edge position information can be calculated. Therefore, it is possible to construct an arbitrary irregular reflection optical system suitable for the surface of the steel plate 1, and the luminance change only at a predetermined light receiving angle due to a slight irregular reflection difference occurring on the surface of the ridge and the angle dependency of the reflectance. It is possible to pick up an image at an optimal light receiving angle (that is, a vertical reflection angle) and to detect an edge position in real time for the soot that could not be obtained.

  Also, as shown in FIG. 3, the optical axis of the two-dimensional imaging device 20 reflects at a vertical reflection angle β (difference from the vertical incident angle is 0 ° to 5 °) substantially equal to the vertical incident angle α. If the control device 30 selects a pixel row so as to receive light at the r-th row of the CMOS image sensor 22 of the light receiving surface 21 of the two-dimensional imaging device 20 that receives reflected light, a regular reflection optical system can be constructed. It becomes easy to detect the irregularity wrinkles. Here, in order to construct the regular reflection optical system, in order to select the r-th column of the CMOS image sensor 22, the intensity of the reflected light may be measured and the pixel column having the highest intensity may be selected. In addition, when the steel plate formation is a mirror surface, intense reflected light from the formation is obtained by selecting a pixel row that satisfies the condition (twisting zone) shifted by about ± 1 to 2 ° from the regular reflection optical system. As a result, it is possible to obtain a result that the fine concavo-convex characteristic flaws can be realized. FIG. 5B shows, as an example, an image obtained when photographing regular reflection unevenness wrinkles (疵 H) and foreign matter adhesion (疵 G) that is colored wrinkles. In FIG. 5B, Ip is a frame image obtained by the regular reflection optical system (that is, an example in which p = r), and Iq is a frame image obtained by the irregular reflection optical system. From the image obtained with the regular reflection optical system, it is possible to reliably detect minute irregularities and the like, and from the image obtained from the irregular reflection optical system, colored wrinkles such as foreign matter adhesion.

(Operator 疵 display device 33)
The operator wrinkle display device 33 is configured by a display device such as a computer display, for example, and superimposes a signal including the detected wrinkle image sent from the wrinkle image processing device 32 and a feature amount extracted from the wrinkle image, The image and feature amount of the cocoon are displayed. Here, for example, the feature amount includes data such as the type of soot, the occurrence position on the steel plate, the size, and the degree of harmfulness.

(Wrinkle image processing device 32)
The image processing device 32 receives the frame image created from the plurality of column unit images by the control device 30 and the edge position information from the edge calculation device 31, and improves the image quality such as shading correction on the frame image. Image processing such as image analysis such as labeling processing and geometric feature extraction, and wrinkle determination processing are performed to detect harmful flaws. For example, as disclosed in Patent Document 3 by the present applicant, an image including a pattern having a specific shape is extracted from the extracted candidate image from the obtained frame image, and a predetermined image is added to the extracted image. By performing image processing to detect harmful flaws, it is possible to narrow down the image processing target to detect harmful flaws and to detect wrinkles at high speed and with high accuracy and to efficiently perform image processing only on the steel plate surface portion. Even if the steel plate moving on the roll causes a meander called a so-called walk, the occurrence position of harmful flaws can be accurately calculated from the steel plate edge.

(Program etc.)
The control device 30, the edge calculation device 31, and the eyelid image processing device 32 may be configured by individual dedicated devices, but a keyboard, a mouse, and the like for each operator to input setting values for the eyelid detection described above. It is also possible to configure the computer with an input device, an input / output interface with the operator display device 33, an internal memory including an image memory, an external recording device such as a DVD-RAM or HDD, and a computer display. The control device 30, the edge calculation device 31, and the eyelid image processing device 32 may be configured by separate computers, respectively, or may be configured by a single unit in order to reduce the installation location and production cost. In addition, a process for controlling a production line for steel plates, etc. = an I / O board connected to a computer or a LAN or a dedicated cable, etc., so that information on the type of steel plate to be inspected can be obtained from the process computer Alternatively, the wrinkle detection result may be output to the process computer. The above-described control and each data processing (information processing) performed by the control device 30, the edge device 31, and the eyelid image processing device 32 in the apparatus configured by a computer or the like in this way are the eyelid image measurement program and the eyelid image processing created in advance. The program is loaded into the HDD and internal memory and executed.

<Summary>
As described above, according to the embodiment of the present invention, by selecting the pixel column of the light receiving unit 21 of the two-dimensional imaging device 20, the number of imaging devices can be increased at a plurality of light receiving angles at the same time without increasing the number of imaging devices. Multiple captured images can be obtained, and regular reflection optical systems and diffuse reflection optical systems can be easily constructed, enabling real-time detection of wrinkles that can only change brightness at a predetermined light receiving angle. Therefore, it is possible to perform inspection corresponding to various wrinkles generated on the steel plate at low cost and easily.

  As mentioned above, although preferred embodiment of this invention was described in detail, referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to this example. It is obvious that a person having ordinary knowledge in the technical field to which the present invention pertains can come up with various changes or modifications within the scope of the technical idea described in the claims. Of course, it is understood that these also belong to the technical scope of the present invention.

It is a figure which shows the outline of the wrinkle inspection apparatus of one embodiment of this invention. It is a top view which shows arrangement | positioning of the illuminating device and 2D imaging device which were seen from the upper direction of the eyelid inspection apparatus of embodiment shown in FIG. It is a side surface layout diagram of the wrinkle inspection apparatus of embodiment shown in FIG. It is a figure which shows typically the CMOS image sensor of the light-receiving part of a two-dimensional imaging device. It is explanatory drawing of the outline of the method of deriving | requiring a frame image from two column unit images. It is a figure which shows the brightness | luminance profile of two column unit images.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Steel plate 2 Roll 10 Illuminating device 11 Light source 12 Optical fiber bundle 13 Optical fiber bundle input terminal 14 Light is a fiber bundle output terminal 20 Two-dimensional imaging device 21 Light receiving part 22 CMOS imaging element 30 Control device 31 Edge calculation device 32 疵 Image processing device 33 Operator疵 Display device 40 PLG
L1 Band-shaped light LA Band-shaped light irradiation region LE Edge calculation search region Lp, Lq Imaging position (partial region) in the band-shaped light irradiation region

Claims (7)

In the portion of the belt-like body conveyed by the roll, the belt-like light is irradiated on the entire surface in the width direction of the surface of the belt-like body, and the belt-like light is irradiated from the belt-like light irradiation region. An apparatus for inspecting wrinkles on the surface of the band-shaped body by imaging reflected light of the band-shaped light,
An illumination device that irradiates a band-shaped light that converges in accordance with a roll diameter so that a vertical incident angle of the band-shaped light with respect to the band-shaped body is equal to a predetermined value set in advance at all points in the band-shaped light irradiation region. When,
A plurality of partial regions that are arranged opposite to the illumination device across the band-shaped light irradiation region and that are different in position in the moving direction of the band-shaped body in the band-shaped light irradiation region in synchronization with the movement of the band-shaped body. A partially readable two-dimensional imaging device that captures images at a plurality of different vertical reflection angles and outputs a plurality of column unit images;
Luminance information from at least one column unit image of the plurality of column unit images while a frame image is configured from each of at least two column unit images of the plurality of column unit images. Using an edge calculating device for calculating the edge position of the strip,
A wrinkle image processing device that performs image processing on the frame image to detect wrinkles on the surface of the strip;
A surface defect inspection apparatus comprising: The two-dimensional imaging device includes a two-dimensional CMOS camera having a two-dimensional pixel array composed of a plurality of CMOS image sensors, and outputs the column unit image of an arbitrary pixel column from the pixel array according to an instruction from a control device. And
The control device designates a plurality of pixel columns of the two-dimensional CMOS camera to the two-dimensional imaging device in order to image the plurality of partial regions corresponding to the plurality of vertical reflection angles set in advance. And further arranging and synthesizing at least two column unit images of the plurality of column unit images corresponding to the plurality of partial regions input from the two-dimensional imaging device, Constructing a frame image obtained by imaging the belt-shaped light irradiation region by each of the vertical reflection angle represented by each of the above column-unit images,
The edge calculation device uses the luminance information from one or more column unit images of the plurality of column unit images while the frame images of the vertical reflection angles are formed, and Calculate the edge position,
The surface flaw inspection apparatus according to claim 1. The control device is different from the partial areas corresponding to the at least two or more column-unit images used to construct the frame image, and the image brightness of the roll surface and the image brightness of the belt-like body surface, In order to capture a partial region corresponding to the vertical reflection angle at which the difference between the two is equal to or greater than a preset edge luminance difference threshold value, at least once during the construction of the frame image, the pixel array of the two-dimensional CMOS camera is Specify and instruct the 2D imaging device;
The two-dimensional imaging device outputs a column unit image corresponding to a partial region corresponding to the vertical reflection angle to the edge calculation device,
The edge calculation device calculates the edge position of the strip from the luminance information of the column unit image input from the secondary imaging device.
The surface inspection apparatus according to claim 1 or 2, wherein The controller is configured to each of the at least two column-unit images used to form the frame image at a time point when the front end portion immediately after the connecting portion of the belt-like bodies that are connected to each other is imaged. In order to photograph a plurality of partial areas respectively corresponding to a plurality of vertical reflection angles different from the corresponding partial areas, a pixel column of the two-dimensional CMOS camera is designated and a two-dimensional imaging device is instructed.
The two-dimensional imaging device outputs a plurality of column unit images respectively corresponding to a plurality of partial regions respectively corresponding to the plurality of vertical reflection angles to the edge calculation device;
The edge calculation device is configured such that a difference between an image luminance of the roll surface and an image luminance of the belt-like body surface is set as a predetermined edge luminance difference from the plurality of column unit images input from the secondary imaging device. Determine the vertical reflection angle that is above the threshold,
The surface flaw inspection apparatus according to claim 3. The control device detects the edge of the strip according to the width information of the strip input from the host computer at the time when the tip portion immediately after the connecting portion of the strip transported connected to each other is imaged. In order to image a predetermined two-dimensional region in the vicinity, set pixels in predetermined rows and columns and instruct the two-dimensional imaging device;
The two-dimensional imaging device outputs a predetermined two-dimensional region image near the edge to the edge calculation device,
The edge calculation device is configured such that a difference between the image luminance of the roll surface and the image luminance of the band-like surface is a preset edge luminance difference threshold value from the two-dimensional region image input from the secondary imaging device. Determine the vertical reflection angle to be above,
The surface inspection apparatus according to claim 3. In the portion of the belt-like body conveyed by the roll, the belt-like light is irradiated on the entire surface in the width direction of the surface of the belt-like body, and the belt-like light is irradiated from the belt-like light irradiation region. It is a surface wrinkle inspection method for imaging reflected light of a band-shaped light and inspecting wrinkles on the surface of the band-shaped body,
With the illuminating device, the band-shaped light that converges in accordance with the roll diameter is adjusted so that the vertical incident angle of the band-shaped light with respect to the band-shaped body is equal to a predetermined value set in advance at all points of the band-shaped light irradiation region. Irradiating step;
Movement of the band-like body within the band-like light irradiation area is performed in synchronization with the movement of the band-like body by a two-dimensional imaging device that is arranged opposite to the illumination device with the band-like light irradiation area interposed therebetween and capable of partial reading. Imaging a plurality of partial regions having different positions in the direction at a plurality of different vertical reflection angles, and outputting a plurality of column unit images;
While the frame image is constructed from each of at least two or more column unit images of the plurality of column unit images by the edge calculation device, at least one or more column units of the plurality of column unit images Calculating the edge position of the strip using luminance information from the image;
A step of image-processing the frame image by a heel image processing device to detect a fold on the surface of the strip;
A method for inspecting surface wrinkles, comprising: In the portion of the belt-like body conveyed by the roll, the belt-like light is irradiated on the entire surface in the width direction of the surface of the belt-like body, and the belt-like light is irradiated from the belt-like light irradiation region. A computer that controls a surface wrinkle inspection device having an illumination device, a two-dimensional imaging device, an edge calculation device, and a wrinkle image processing device for imaging reflected light of the band light and inspecting wrinkles on the surface of the band. ,
Strip light that converges in accordance with the roll diameter so that the vertical incident angle of the strip light on the strip is equal to a predetermined value at all points in the strip light irradiation region by the illumination device. Irradiating with
The two-dimensional imaging device that is disposed opposite to the illumination device with the band-shaped light irradiation region interposed therebetween and is capable of partially reading out, in synchronization with the movement of the band-shaped body, of the band-shaped light irradiation region. A process of imaging a plurality of partial areas with different positions in the moving direction at a plurality of different vertical reflection angles and outputting a plurality of column unit images;
While the frame image is formed from each of at least two or more column unit images of the plurality of column unit images by the edge calculation device, at least one or more columns of the plurality of column unit images. Using the luminance information from the unit image, a process for calculating the edge position of the strip,
Processing to detect wrinkles on the surface of the strip by performing image processing on the frame image by the wrinkle image processing device;
A program for running