JP4901578B2 - Surface inspection system and diagnostic method for inspection performance of surface inspection system - Google Patents

Description

  The present invention relates to a surface inspection system including a light source that irradiates light onto the surface of a belt-shaped object to be transported, and an imaging device that receives reflected light from the belt-shaped object to be imaged, and a surface inspection system. The present invention relates to a diagnostic method for inspection performance.

  In conveying lines such as steel plates, non-ferrous metal plates, paper or non-woven fabrics, the surface of these thin strip-shaped inspected objects is optically inspected by a surface inspection device to detect wrinkles, etc. .

  As a surface inspection apparatus, for example, a surface of a strip-like object is scanned while moving a point light source such as a laser in a direction (width direction) perpendicular to the transport direction of the strip-like subject, and the reflected light is photomultiplier tube What receives light with optical elements, such as, is known. In addition, a light source that irradiates a belt-like light source in the width direction of the surface of the belt-like object to be inspected and receives the reflected light by an imaging device such as a CCD array sensor is known. The signal obtained as a result is subjected to various types of signal processing to detect wrinkles on the surface of the strip-like object, and further to determine the type and degree of wrinkles.

  By the way, the inspection performance of the surface inspection system is based on the positional deviation and dirt of the light source, light receiver or lens, mirror, etc. existing on the optical path, dirt on the light projection window and light receiving window of the light source, and the amount of light due to deterioration over time of the light source. It is inevitable that it will decrease due to a decrease. Furthermore, it changes due to various factors such as characteristics change or failure of the conversion / input unit when the signal of the light receiver is taken into the signal processing unit, characteristic change or setting failure or failure in the signal processing unit.

  In addition, in a compound eye type imaging system that separately detects regular reflection and irregular reflection with a plurality of imaging devices, if the position being inspected by regular reflection and irregular reflection shifts due to plate thickness fluctuation or mechanical deviation, The correct inspection cannot be performed.

  On the other hand, the surface inspection system can detect minute defects on high-speed lines that cannot be handled by human visual inspection. Therefore, even if an abnormality such as a sensitivity change occurs in the surface inspection system, There is a risk that a large amount of defects may flow out or the work efficiency of the line may be significantly reduced due to erroneous detection.

  Until now, it has been common to periodically diagnose inspection performance from the optical system to signal processing when the line is stopped at a timing of 6 to 12 times / year, called regular repair. .

  On the other hand, as a technique for diagnosing the inspection performance of the surface inspection system, Patent Document 1 provides an opening penetrating the strip-shaped object (steel plate), and surface inspection is performed based on the magnitude of reflected light intensity in the opening. It is disclosed to calibrate the optical system of the apparatus.

  Further, in Patent Document 2, a self-diagnosis device receives a signal when a welding line of a thin steel plate is detected by a surface flaw detection unit, detects whether it is a specified pattern, It is disclosed that when a normal pattern is obtained, it is determined that the surface defect inspection apparatus is normal.

  Further, in Patent Document 3, an artificial defect having a specific size is provided at a specific position of the strip-shaped object to be inspected, and the size of the detected artificial defect is compared with a known value. Inspection is disclosed.

JP-A-11-132967 JP 2001-165867 A JP 2002-90306 A

However, the method disclosed in Patent Document 1 has the following problems.
(1) Since an opening penetrating the strip-shaped object to be inspected (steel plate) must be provided, and equipment and work for that purpose are required, this imposes a large cost burden.
(2) In general production lines, products with a wide variety of surface skin are often produced, and illumination light sources often deteriorate over time. In general, the light receiving sensitivity is automatically adjusted so that the level becomes constant. Therefore, it is not possible to know the sensitivity change of the device only by measuring the absolute signal intensity of the measurement target, and measuring the signal intensity before the sensitivity is automatically adjusted greatly affects the degree of deterioration of the light source. Therefore, even if the light source deterioration level is within an allowable range, it is recognized as abnormal.
(3) Although the resolution of the surface inspection apparatus is not specified in Patent Document 1, for example, when the resolution is sufficiently smaller than the size of the opening, the reflected light intensity is 0. Since the reflected light intensity changes depending on the background, the roughness of the processed surface of the opening, etc., the sensitivity cannot be measured stably.
(4) In addition, Patent Document 1 proposes a technique for supporting a belt-like object under test with a support material having a reflectance different from that of the belt-like object under examination in order to solve the problem (3). In the support material as proposed, the reflectance changes due to secular change or dirt, so that the sensitivity cannot be measured stably. In addition, installing such equipment is a heavy burden in terms of cost.

In addition, the technique disclosed in Patent Document 2 has the following problems.
(1) The weld line (weld mark) does not always have a fixed shape. For this reason, the welding trace is normal, but the surface inspection device is not operating properly, so the specified pattern due to the welding trace is not output, or the surface inspection device is operating normally, but the welding trace is abnormal. For this reason, it is impossible to determine whether a prescribed pattern due to welding marks is not output.

In addition, the technique disclosed in Patent Document 3 can avoid the problems caused by the magnitude of the reflected light intensity as in Patent Document 1, but has the following problems.
(1) When a linear flaw is provided as an artificial defect, or when a dot-like defect is provided using a punch or the like, facilities and work for it are necessary, which is a heavy burden in cost. End up.
(2) Since artificial defects of a specific size are provided, it is not possible to guarantee the inspection performance for wrinkles of various sizes and shapes.
(3) Since an artificial defect is provided at a specific position, the inspection performance at an arbitrary position in the width direction of the strip-shaped object cannot be guaranteed.

  Further, for example, when the plate thickness fluctuates due to a plurality of types of steel plates (coils) as the band-shaped object to be inspected, the position of the defect on the surface of the band-shaped object to be measured varies. For this reason, in a compound eye type imaging system that images regular reflection and irregular reflection separately, an inspection position shift in the captured image occurs due to regular reflection and irregular reflection. In order to calibrate this deviation, information on the plate thickness of the coil to be manufactured (upper information) is received from a higher-level device such as a higher-level computer that manages the production line, and a captured image is obtained by a preset position change based on the plate thickness. In general, calibration is performed by shifting the coordinates in the image, and the correspondence between the positions of the regular reflection and the irregular reflection in the captured image is generally maintained. However, because the upper information transmitted for each coil is the plate thickness that is scheduled to be manufactured, the accuracy is low, and the plate thickness of the upper information is reduced by the coil number deviation or transmission error due to the failure of the upper device. Abnormalities such as “zero” may occur. If it is a complicated system, it is difficult to perform the above calibration of each coil appropriately and flexibly. Even when the plate thickness fluctuates in the surface inspection system of the strip-like object, the inspection performance is accurate, flexible, and It was difficult to perform stably.

  The present invention has been made in view of the above points, and avoids problems in diagnosing the inspection performance by providing an opening in the strip-shaped object to be inspected or using a weld line, and stops the line. It is a first object of the present invention to make it possible to stably diagnose inspection performance without any problems. It is a second object of the present invention to ensure the inspection performance for wrinkles of various sizes and shapes and the inspection performance at an arbitrary position in the width direction of the strip-shaped object. Furthermore, the third object is to flexibly diagnose the inspection performance of the surface inspection system even when the plate thickness of the strip-shaped object to be inspected fluctuates.

A surface inspection system according to the present invention is a surface inspection system including a light source that irradiates light on the surface of a belt-shaped object to be transported and an imaging device that receives reflected light from the belt-shaped object to be imaged. And when diagnosing the inspection performance of the surface inspection system, a spot irradiation device that irradiates the surface of the strip-shaped inspection object with light having a luminance different from that of the light of the light source, and the strip-shaped inspection target The lighting time control means for controlling the lighting time of the spot irradiation device according to the conveyance speed, and determining one or both of the image shape and the image luminance due to the spot irradiation appearing in the captured image, thereby allowing the surface inspection system to and a diagnostic means for diagnosing the test performance, the imaging device is a multiple, imaging the same spot irradiating the surface of the strip to be inspected, the spot irradiation instrumentation The shape of the spot irradiation is a straight line that is oblique with respect to the transport direction of the strip-shaped object, and the diagnostic means determines the imaging from the difference in the position of the spot irradiation image in each captured image of the imaging device. It is characterized in that a deviation in the installation state of the apparatus is detected .
Another feature of the surface inspection system according to the present invention is that it further includes a lighting intensity control means for controlling the lighting intensity of the spot irradiation device that irradiates the strip-shaped object to be inspected.
Further, another feature of the surface inspection system of the present invention is that the lighting time control means controls the lighting time of the spot irradiation device with a plurality of patterns.
Another feature of the surface inspection system of the present invention is that the position of spot irradiation by the spot irradiation apparatus can be moved in the width direction of the strip-shaped object to be inspected.
Another feature of the surface inspection system according to the present invention is that a plurality of imaging devices are arranged in the width direction of the band-shaped object to be inspected, and spot irradiation can be simultaneously performed on the imaging range of each imaging device. In the point.
Another feature of the surface inspection system of the present invention is that the spot irradiation device is a laser pointer.
The diagnostic method of the inspection performance of the surface inspection system according to the present invention includes a light source that irradiates light on a surface of a belt-like object to be transported, and an imaging device that receives reflected light from the belt-like object and images it. A method for diagnosing the inspection performance of a surface inspection system provided using a spot irradiation device that spot-irradiates light having a luminance different from that of the light from the light source onto the surface of the band-shaped object to be inspected. The surface inspection system by determining one or both of a lighting time control step for controlling a lighting time of the spot irradiation device in accordance with a conveyance speed of the image and an image shape and an image luminance due to spot irradiation appearing in the captured image. A diagnostic step for diagnosing the inspection performance, wherein the imaging device includes a plurality of imaging devices, and images the same spot irradiation on the surface of the strip-shaped object to be inspected. The shape of the spot irradiation of the shooting device is a straight line oblique to the transport direction of the strip-shaped object, and in the diagnostic step, from the difference in the position of the spot irradiation image in each captured image of the imaging device, It is characterized in that a shift in the installation state of the imaging device is detected .

  According to the present invention, when diagnosing the inspection performance of the surface inspection system, the surface of the band-shaped object to be inspected is irradiated with a spot. Therefore, an opening is provided in the band-shaped object to be inspected or a welding line is used. Therefore, it is possible to avoid problems in diagnosing the inspection performance and to stably diagnose the inspection performance without stopping the line.

  Furthermore, if the spot irradiation position is moved in the width direction of the steel plate, the inspection performance at an arbitrary position in the width direction can be guaranteed. Further, if the control pattern of the lighting time of the spot irradiation device is changed, the spot irradiation pattern can be changed, so that the inspection performance for wrinkles of various sizes and shapes can be guaranteed.

  Furthermore, by making the spot irradiation shape of the spot irradiation device a straight line oblique to the conveying direction of the steel sheet, images of the same part of the belt-like object to be inspected that move regular reflection and irregular reflection with a plurality of imaging devices can be obtained. When imaging, it is possible to diagnose the inspection performance of the surface inspection system by detecting the presence / absence of the imaging position of each imaging apparatus, that is, the inspection position, and the magnitude of the deviation.

  As described above, the present invention is suitable for flexibly diagnosing the inspection performance of the surface inspection system even when the plate thickness of the strip-shaped inspection object varies.

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.
(First embodiment)
FIG. 1 shows a schematic configuration of the surface inspection system according to the first embodiment. The present embodiment is an example in which a surface inspection system is installed on a continuous production line for steel plates. In a continuous production line for steel sheets, the front and rear ends of each lot (coil) to be processed continuously are welded at the entry side of the line, and this is conveyed at high speed, rolling, pickling, plating, annealing, etc. The above process is performed, and the welded portion is cut on the exit side of the line to be wound into a coil shape for each lot. The surface inspection of the steel sheet is performed on the exit side of the production line in order to inspect abnormalities occurring in the line.

  As shown in FIG. 1, the surface inspection system includes a light source 103 that irradiates light onto the surface of a steel plate 102 that is conveyed on a roll 101. For example, a fluorescent lamp or a halogen lamp is used as the light source 103.

  Moreover, the camera 104 which receives the reflected light from the steel plate 102 and images it is provided. In the present embodiment, two cameras 104 are arranged in the width direction of the steel plate 102. As the camera 104, for example, a line sensor camera that obtains a captured image by receiving reflected light from the steel plate 102 and performing photoelectric conversion with a CCD is used.

  Furthermore, a laser pointer 105 is provided as a spot irradiation device that irradiates the surface of the steel plate 102 with laser light at an appropriate angle. The laser pointer 105 irradiates the surface of the steel plate 102 with light having a luminance higher than that of the light from the light source 103. In the present embodiment, a total of two laser pointers 105 are arranged above each camera 104. As the laser pointer 105, a semiconductor laser is preferable because it is inexpensive and easy to control the lighting time, but a helium neon laser or the like may be used. In this case, a shutter for controlling the transmission of the laser beam may be provided before the helium neon laser or the like.

  Although not specifically shown, each laser pointer 105 is slidable in the width direction of the steel plate 102, and the irradiation position of the laser beam can be moved in the width direction of the steel plate 102. In addition, you may make it move the irradiation position of a laser beam to the width direction of the steel plate 102 by swinging each laser pointer 105. FIG.

  In the present embodiment, the same number of laser pointers 105 are arranged corresponding to the number of cameras 104. However, for example, by dividing the laser light emitted from one laser pointer via a half mirror, the field of view of each camera 104 is displayed. You may make it irradiate a laser beam simultaneously to (imaging range).

  The image processing circuit 106 includes a preprocessing unit that performs various correction processes such as shading correction on a signal input from the camera 104, an extraction unit that extracts a wrinkle candidate from an image processed by the preprocessing unit, and the like. When the camera 104 has an analog output, an A / D converter that converts an analog signal into a digital signal is also included.

  The feature amount calculation unit 107 calculates feature amounts such as the length, width, area, and luminance of the wrinkle candidate extracted by each image processing circuit 106.

  The wrinkle determination unit 108 determines the type and degree of a wrinkle candidate extracted by each image processing circuit 106 according to a predetermined algorithm based on the feature amount calculated by the feature amount calculation unit 107. The type and degree of wrinkles determined by the wrinkle determination unit 108 are output to the display device 109.

  The lighting control unit 110 controls the lighting time of each laser pointer 105 according to the conveyance speed of the steel plate 102, specifically, the PLG pulse signal acquired from the roll 101. The lighting control unit 110 may control the lighting intensity of each laser pointer 105.

  The diagnosis unit 111 diagnoses the inspection performance of the surface inspection system by determining the image shape and / or the image brightness due to the irradiation of the laser beam appearing in the captured image. The result diagnosed by the diagnosis unit 111 is output to the display device 109.

  Hereinafter, diagnosis of the inspection performance of the surface inspection system will be described in detail with reference to FIGS. 2A to 2D and FIG. 3. In this example, the width of the laser light irradiated from the laser pointer 105 onto the surface of the steel plate 102 is 0.5 mm (corresponding to 2 pixels). Further, the steel plate 102 is conveyed by 0.25 mm in one cycle of the PLG pulse signal.

  As shown in FIG. 2A (a), when the lighting control unit 110 turns on the laser pointer 105 for two periods of the PLG pulse signal, the laser beam is 0.5 mm wide × length on the surface of the steel plate 102. Irradiation is in the form of 0.5 mm square dots.

  In this case, if the inspection performance of the surface inspection system is normal, as shown in FIGS. 2A (b) and 2 (c), the captured image obtained through each image processing circuit 106 has a width of the image obtained by laser light irradiation. Appears as dots of 0.5 mm x 0.5 mm in length. Therefore, the diagnosis unit 111 determines that the inspection performance of the surface inspection system is normal when it can be correctly determined that the image of the laser light irradiation is point-like. On the other hand, when it cannot be correctly determined that the image by the laser light irradiation is point-like, or when the image itself by the laser light irradiation is not detected, it is determined that the detection performance is abnormal.

  Further, as shown in FIG. 2B (a), when the lighting control unit 110 turns on the laser pointer 105 for a period of 200 cycles of the PLG pulse signal, the laser beam has a width of 0.5 mm × Irradiation is in the form of a line having a length of 50 mm.

  In this case, if the inspection performance of the surface inspection system is normal, as shown in FIGS. 2B (b) and 2 (c), the captured image obtained through each image processing circuit 106 has a width obtained by irradiation with laser light. Appears in a line of 0.5 mm x 50 mm in length. Therefore, the diagnosis unit 111 determines that the inspection performance of the surface inspection system is normal when the image by the laser light irradiation can be correctly determined to be linear. On the other hand, when it cannot be correctly determined that the image by laser light irradiation is linear, or when the image itself by laser light irradiation is not detected, it is determined that the detection performance is abnormal.

  Further, as shown in FIG. 2C (a), when the lighting control unit 110 repeatedly turns on the time laser pointer 105 of the four cycles of the PLG pulse signal and turns off the time laser pointer 105 of the subsequent four cycles, The surface of the steel plate 102 is irradiated with laser light in a dotted line shape having a width of 0.5 mm and a length of 1 mm.

  In this case, if the inspection performance of the surface inspection system is normal, as shown in FIGS. 2C (b) and 2 (c), the captured image obtained through each image processing circuit 106 has a width obtained by irradiation with laser light. Appears as a dotted line of 0.5 mm × 1 mm in length. Therefore, the diagnosis unit 111 determines that the inspection performance of the surface inspection system is normal when it can be correctly determined that the image by laser light irradiation is dotted. On the other hand, when it cannot be correctly determined that the image by laser light irradiation is dotted, or when the image itself by laser light irradiation is not detected, it is determined that the detection performance is abnormal.

  Also, as shown in FIG. 2D (a), the lighting control unit 110 repeatedly turns on the time laser pointer 105 of the four cycles of the PLG pulse signal and turns off the time laser pointer 105 of the subsequent four cycles. When the laser intensity is controlled stepwise, the surface of the steel plate 102 is irradiated with laser light having a dotted line shape having a width of 0.5 mm and a length of 1 mm that gradually increases in luminance.

  In FIGS. 2A to 2D, images (dots, lines, dotted lines) by laser light irradiation are shown in black, but in reality, they appear white because of high luminance. Further, although an example in which the same irradiation pattern is used by the two laser pointers 105 is illustrated, different irradiation patterns may be used.

  When diagnosing the inspection performance of the surface inspection system described above, without suspending the production line, for example, by irradiating the tip or tail of the steel plate 102 of each coil with laser light in real time for each coil. Inspection performance can be diagnosed. Therefore, if an abnormality is found in the inspection performance, the surface inspection system can be immediately investigated and repaired, and the coil immediately before the occurrence of the abnormality and the current flowing coil can be re-inspected. That's fine.

  In this case, as shown in FIG. 3, for example, the inspection performance at an arbitrary position in the width direction can be ensured by moving the irradiation position of the laser beam for each coil in the width direction of the steel plate 102. In the illustrated example, the irradiation position of the laser beam is moved for each coil, such as the left side of the field of view for the first coil, the center of the field of view for the second coil, the right side of the field of view for the third coil, and so on. Yes.

  In addition, for example, by changing the control pattern of the lighting time of the laser pointer 105 for each coil, the irradiation pattern can be changed to a dot shape, a line shape, a dotted line shape, etc., so that inspection performance for wrinkles of various sizes and shapes Can be guaranteed.

  As described above, when diagnosing the inspection performance of the surface inspection system, the laser beam is irradiated to the surface of the steel plate 102 by the laser pointer 105. Therefore, an opening is provided in the steel plate or a welding line is used. Thus, problems in diagnosing the inspection performance can be avoided, and the inspection performance can be stably diagnosed without stopping the line. That is, since it is not necessary to provide an opening penetrating the steel plate, there is no need for equipment and work for that purpose, and a simple configuration in which an inexpensive laser pointer 105 is simply installed can be achieved. Further, unlike welding marks, laser light can be stably irradiated in a certain shape (for example, a dot shape, a line shape, or a dotted line shape).

(Second Embodiment)
In the second embodiment, as shown in FIG. 4, a regular reflection camera 104 a installed in the regular reflection direction of the reflected light from the steel plate 102 by the light source 103 and a irregular reflection camera 104 b installed in the irregular reflection direction. It is an example provided. In addition, the same code | symbol is attached | subjected and demonstrated to the component similar to the said 1st Embodiment, and the detailed description is abbreviate | omitted.

  In the present embodiment, the laser pointer 105 is disposed between the regular reflection camera 104a and the irregular reflection camera 104b. Both the regular reflection camera 104a and the irregular reflection camera 104b are arranged in the width direction of the steel plate 102 (direction perpendicular to the paper surface of FIG. 4), as in the first embodiment. .

  In this way, by using the pair of regular reflection cameras 104a and the irregular reflection cameras 104b, images of the same location are taken at different angles. It is possible to perform high-precision wrinkle determination by extracting feature amounts from images of the regular reflection camera 104a and the irregular reflection camera 104b and superimposing or taking a difference. Furthermore, it is also possible to perform high-precision wrinkle determination by directly superimposing the images of the regular reflection camera 104a and the irregular reflection camera 104b or taking the difference. That is, the pair of regular reflection cameras 104a and the irregular reflection cameras 104b are set so as to capture the same point on the surface of the steel plate 102.

  By applying the present invention, it is possible to correct the shift of the imaging point between the pair of regular reflection cameras 104a and the irregular reflection cameras 104b. That is, as shown in FIG. 5, a laser beam is emitted from the laser pointer 105 and a captured image (see FIG. 5A) obtained by the regular reflection camera 104a and a captured image (see FIG. 5A) (see FIG. 5). (See FIG. 5B).

  In the regular reflection image and the irregular reflection image, the diagnosis unit 111 determines that there is no shift of the imaging points by these cameras 104a and 104b when images by laser light irradiation appear in both. On the other hand, if only one image by laser light irradiation appears in either regular reflection or irregular reflection, it is determined that there is a shift in the imaging points by these cameras 104a and 104b. In the example of FIG. 5, since a spot appears for both the regular reflection image and the irregular reflection image for the camera 1, it is OK (no shift), whereas for the camera 2, no spot appears for the irregular reflection image. (There is a gap).

Next, the shape of the spot irradiation is changed to a linear shape, and the laser beam is irradiated onto the steel plate 102 in an oblique straight line having an angle θ (degrees) with respect to the conveying direction of the steel plate 102 as shown in FIG. . For example, when the laser pointer 105 is turned on for a period of 200 cycles of the PLG pulse signal, as shown in FIG. 7, a regular reflection image (see FIG. 7A) and a diffuse reflection image (see FIG. 7B) are used. A difference appears in the image position of spot irradiation, and a line having a length of 50 mm shifted by Δ pixels as shown in the OR image of FIG. 7C is photographed.

here,
S = Δtan (90−θ)
Therefore, the camera installation state can be determined to be abnormal, for example, by calculating a finite-value camera displacement amount S and comparing it with a management value set based on the resolution of the captured image and the desired inspection accuracy. Furthermore, the installation state of the imaging apparatus such as the camera installation position and the optical axis can be corrected based on the deviation amount S.

  Furthermore, the laser beam is irradiated on the steel plate 102 in an oblique linear shape that forms an angle -θ (degrees) together with the laser beam in an oblique linear shape that forms an angle θ (degree) with respect to the conveying direction of the steel plate 102. Thus, the displacement amount of the camera in the direction perpendicular to the conveyance direction can be calculated together with the finite amount of displacement S in the conveyance direction of the camera. As a result, it can be determined that the camera installation state is abnormal. Furthermore, the installation state of the imaging apparatus such as the camera installation position and the optical axis can be corrected based on the deviation amount S.

  When the diagnosis unit 111 determines that there is a shift in the imaging points of the cameras 104a and 104b, as shown in FIG. 7D, the OR image is corrected so that there is one image by the laser beam irradiation line. By shifting the image of at least one of the reflection camera 104a and the irregular reflection camera 104b, it is possible to correct the shift of the imaging point by the cameras 104a and 104b.

  Even for inspection position shifts due to regular reflection and irregular reflection caused by fluctuations in the plate pressure of the steel plate to be photographed, the spot irradiation shape is changed to a linear shape, and oblique lines forming an angle θ in the conveying direction are irradiated on the steel plate 102. By doing this, as described above, the displacement S of the camera can be calculated and the displacement of the imaging point can be corrected.

  In the above two embodiments, when there is a problem with the image, it is determined that the imaging unit or the image processing circuit 106 is abnormal. When the image is normal, there is a problem with the determination of the eyelid inspection apparatus. Since it is possible to determine that the feature amount calculation unit 107 or the wrinkle determination unit 108 is abnormal, it is possible to specify a failure location.

  As mentioned above, although this invention was demonstrated with various embodiment, this invention is not limited only to these embodiment, A change etc. are possible within the scope of the present invention. For example, the number of cameras 104 and laser pointers 105 is not limited to that of the embodiment.

It is a figure showing a schematic structure of a surface inspection system concerning a 1st embodiment. It is a figure for demonstrating the irradiation pattern of a laser beam. It is a figure for demonstrating the irradiation pattern of a laser beam. It is a figure for demonstrating the irradiation pattern of a laser beam. It is a figure for demonstrating the irradiation pattern of a laser beam. It is a figure which shows the state which moves the irradiation position of a laser beam for every coil to the width direction of a steel plate. It is a figure which shows schematic structure of the surface inspection system which concerns on 2nd Embodiment. It is a figure for demonstrating the diagnosis of the inspection performance of the surface inspection system in 2nd Embodiment. It is a figure for demonstrating the irradiation pattern of the laser beam which concerns on 2nd Embodiment. It is a figure for demonstrating the diagnosis of the inspection performance of the surface inspection system in 2nd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Roll 102 Steel plate 103 Light source 104 Camera 105 Laser pointer 106 Image processing circuit 107 Feature amount calculation part 108 Haze determination part 109 Display apparatus 110 Lighting control part (time or intensity)
111 Diagnostic Department

Claims (7)

A surface inspection system comprising a light source for irradiating light on the surface of a belt-shaped object to be transported, and an imaging device for receiving and imaging reflected light from the belt-shaped object,
When diagnosing the inspection performance of the surface inspection system, a spot irradiation device that irradiates the surface of the strip-shaped inspection object with light having a luminance different from that of the light of the light source ; and
Lighting time control means for controlling the lighting time of the spot irradiation device according to the transport speed of the strip-shaped object;
A diagnostic means for diagnosing the inspection performance of the surface inspection system by determining one or both of the image shape and the image luminance due to spot irradiation appearing in the captured image ;
The imaging device is a plurality, and images the same spot irradiation on the surface of the strip-shaped object to be inspected,
The shape of spot irradiation of the spot irradiation device is a straight line oblique to the transport direction of the strip-shaped object to be inspected,
2. The surface inspection system according to claim 1, wherein the diagnostic unit detects a shift in an installation state of the imaging device from a difference in position of an image of spot irradiation in each captured image of the imaging device . The surface inspection system according to claim 1 , further comprising a lighting intensity control unit that controls a lighting intensity of the spot irradiation device that irradiates the strip-shaped object to be inspected. The lighting time control means, the surface inspection system according to claim 1 or 2, characterized in that to control the lighting time of the spot irradiation device in a plurality of patterns. Surface inspection system according to any one of claims 1 to 3, characterized in that it is possible to move the position of the spot irradiation by the spot irradiation device in the width direction of the belt-shaped object to be inspected. The strip being disposed a plurality of imaging devices in the width direction of the inspection object, the to any one of claims 1 to 4, wherein at the same time that the spot can be irradiated to the imaging range of the imaging devices The described surface inspection system. Surface inspection system according to any one of claims 1 to 5, wherein the spot irradiation device is a laser pointer. A method for diagnosing the inspection performance of a surface inspection system, comprising: a light source that irradiates light on a surface of a belt-shaped object to be transported; and an imaging device that receives reflected light from the belt-shaped object to be imaged. ,
Using a spot irradiation device that irradiates the surface of the strip-shaped object with light having a luminance different from that of the light from the light source, and controls the lighting time of the spot irradiation device according to the transport speed of the strip-shaped inspection object A lighting time control step,
A diagnostic step of diagnosing the inspection performance of the surface inspection system by determining either or both of the image shape and the image luminance due to spot irradiation appearing in the captured image;
The imaging device is a plurality, and images the same spot irradiation on the surface of the strip-shaped object to be inspected,
The shape of spot irradiation of the spot irradiation device is a straight line oblique to the transport direction of the strip-shaped object to be inspected,
In the diagnosis step, a method for diagnosing the inspection performance of the surface inspection system is characterized in that a shift in the installation state of the imaging device is detected from the difference in the position of the image of spot irradiation in each captured image of the imaging device .

Images