JP2001289788A - Surface-flaw inspecting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent wrong detections of a boundary part of an oil adhering part as an edge in image processing due to excessive oil adhering to an inspected face, when a vehicle body panel is inspected in-line in a pressing process, for example, by means of a conventional surface-flaw inspecting device. SOLUTION: This surface-flaw inspecting device is provided with an inspected body conveying means 1 for conveying an inspected body P, a pantoscopic lighting means 2 radiating illumination light to the inspected surface, photographing means 3 and 4 photographing the inspected surface, an inspection processing means 5 for detecting a surface flaw from a received optical image, a surface inspecting means 51 for inspecting a surface condition of the inspected surface, an oil condition determining means 52 determining an oil adhering condition on the basis of the surface condition of the inspected surface, and an oil countermeasure directing means 53 for outputting a countermeasure instruction directing one of a change of illumination light irradiation angle, a change of a photographing angle, and control of an oil adhering amount on the inspected surface, according to the determination result from the oil condition determining means 52, and consequently, influence due to excessive oil causing erroneous detection is surface flaw inspection can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for inspecting a surface defect of an object to be inspected, for example, for inspecting a surface defect such as unevenness on the surface of a press-formed body panel in manufacturing an automobile. The present invention relates to a surface defect inspection device used for a device.

[0002]

2. Description of the Related Art A conventional surface defect inspection apparatus is disclosed in, for example, Japanese Patent Application Laid-Open No. 8-5573.

The surface defect inspection apparatus disclosed in the publication is
As shown in FIG. 24A, a surface light source 101 that is positioned diagonally above one side of the device under test 100 and irradiates the surface of the device under test 100 with planar illumination light, and the other of the device under test 100. An area sensor camera 102, which is positioned diagonally above and side and captures an image of the surface of the device under test 100, is provided to detect foreign substances and protrusions present on the surface of the device under test 100. Another surface defect inspection apparatus disclosed in the publication is shown in FIG.
As shown in FIG. 4 (b), a linear light source 103 positioned diagonally above one side of the device under test 100 and irradiating linear illumination light to the surface of the device under test 100, and the other side of the device under test 100 A line sensor camera 104 that is positioned diagonally above and captures an image of the surface of the device under test 100 is provided, and also detects minute protrusions and the like existing on the surface of the device under test 100.

In the above two-surface defect inspection apparatus, the illumination angle α of the illumination light from the light sources 101 and 103 and the camera 10
2 and 104, the imaging angle β is a low angle of 10 degrees or less, and both are almost the same angle. Therefore, the captured image 105 captures the specular reflection light of the illumination light, and captures a foreign object or a defect existing on the surface of the inspection object 100 as a shadow, that is, an image captured as a dark spot 105b in the bright portion 105a. Becomes

[0005]

However, in the above-described conventional surface defect inspection apparatus, if it is installed on a press line of a body panel of an automobile and the body panel is to be inspected in-line, for example, There was such a problem. That is, there is a large variation in the state (amount and distribution) of the cleaning oil adhered by the cleaning performed in the previous process of the press. Since the boundary is erroneously detected as an edge, surface defects cannot be detected with high accuracy, and the reliability of defect detection decreases, so that it is difficult to perform in-line processing.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional situation, and when excessive oil is adhered to a surface to be inspected, excessive oil adherence which is a cause of erroneous detection. It is an object of the present invention to provide a surface defect inspection apparatus capable of minimizing the influence and performing highly accurate defect detection in-line.

[0007]

According to a first aspect of the present invention, there is provided a surface defect inspection apparatus for transporting an object to be inspected in one direction and a surface to be inspected of a moving object to be inspected. An illumination unit that irradiates the illumination light at a predetermined illumination angle, an imaging unit that captures reflected light of the illumination light at an imaging angle larger than the illumination angle of the illumination light, and an inspection target based on a light reception image from the imaging unit. Inspection processing means for detecting surface defects of the surface, surface inspection means arranged upstream of the illumination means and the imaging means in the transport direction of the object to be inspected, and inspecting the surface condition of the surface to be inspected; Oil state determining means for determining the state of oil adhesion based on the surface state of the surface to be inspected, and changing the irradiation angle of illumination light, changing the imaging angle, and Some of the controls on the amount of oil on the inspection surface At least one is provided with oil countermeasure instructing means for outputting as a countermeasure instruction. As a second aspect, the illuminating means is capable of irradiating illumination light on the upstream side and the downstream side in the inspection object transport direction, and Wide-angle illumination means for irradiating the inspection surface of the moving inspection object with illumination light at a predetermined irradiation angle, and the imaging means is located upstream of the inspection object transport direction with the wide-angle illumination means interposed therebetween. And upstream-side and downstream-side imaging means for imaging reflected light of the illumination light at an imaging angle larger than the illumination angle of the illumination light opposite to the wide-angle illumination means. This is a means for solving the conventional problem. In the above-described configuration, the irradiation angle of the illumination light by the illumination means may be adjusted so as to increase the directivity of the reflected light distribution and obtain a high reflectance. ) Is preferably set to 10 degrees or less, and the imaging angle by the imaging unit is also preferably in the range of 10 to 30 degrees with respect to the surface to be inspected.

According to a third aspect of the present invention, there is provided a surface defect inspection apparatus according to the third aspect of the present invention, wherein each of the illuminating means and the imaging means has a predetermined value so that the irradiation angle and the imaging angle of the illuminating light with respect to the moving inspection surface become predetermined values. A configuration including illumination / imaging control means for controlling the angle and each height and controlling the angle and height of at least one of the illumination means and the imaging means based on a countermeasure instruction from the oil countermeasure instruction means; According to a fourth aspect of the present invention, the surface inspection means is means for optically inspecting the surface to be inspected and outputting a surface state at a luminance level, and the oil adhesion state determination means is configured to determine the luminance and the luminance obtained from the surface inspection means. The inspection means is configured to determine an oil adhesion state on the surface to be inspected based on a relationship between the luminance and the oil adhesion amount obtained in advance. An oil adhering amount control means disposed on the upstream side and controlling the oil adhering amount on the surface to be inspected based on a countermeasure instruction from the oil countermeasure instructing means is provided. An oil-squeezing roll that is in rotational contact with the surface to be inspected, and a pressing force control unit that controls a pressing force of the oil-squeezing roll against the surface to be inspected,
According to a seventh aspect of the present invention, there is provided an oil which is disposed upstream of the illumination means and the imaging means in the transport direction of the test object and which evaporates oil on the surface to be inspected based on a measure instruction from the oil measure instruction means and an oil evaporation characteristic. According to claim 8, the oil evaporation control means includes a blower that blows air to the surface to be inspected, an air volume switching device that changes an amount of air from the blower, and a blower. And a heat quantity switching means for changing the temperature of the air, wherein a measure instruction from the oil measure instruction means is disposed upstream of the illumination means and the image pickup means in the test object transport direction with respect to the illumination means and the image pickup means. And an oil wiping means for wiping the oil on the surface to be inspected based on the above.

[0009]

In the surface defect inspection apparatus according to the first aspect of the present invention, the inspection object is transported at a constant speed by the inspection object transporting means such as a belt conveyor, and the illumination is provided above the inspection object transporting means. The means and the imaging means are opposed to each other so that the angle can be adjusted and the height can be adjusted, and the illuminating means illuminates the surface to be inspected of the moving object to be inspected at a predetermined irradiation angle from an obliquely upper side on one side in the transport direction. While irradiating the light, the imaging means images the reflected light from the surface to be inspected at an imaging angle larger than the irradiation angle from obliquely above the other side in the transport direction with respect to the surface to be inspected. At this time, the illuminating means and the imaging means are controlled in angle and height so that the irradiation angle of the illuminating light on the surface to be inspected and the imaging angle always have predetermined values. The illumination angle of the illumination light by the illumination means is a shallow angle of 10 degrees or less with respect to the inspection surface, and the imaging angle of the imaging means is 1 with respect to the inspection surface.
The range is 0 to 30 degrees. In other words, of the illumination light irradiated at the predetermined irradiation angle, the light that hits a portion having no surface defect is not reflected by the image pickup means because it is regularly reflected at the same angle as the irradiation angle, and hits the surface defect and is smaller than the irradiation angle. Only the light diffusely reflected at a large angle is imaged by the imaging means. Therefore, a light receiving image in which the surface defect is captured with high luminance can be obtained by the imaging means.

The light-receiving image thus obtained is taken into the inspection processing means, which performs image processing such as edge extraction processing, smoothing processing, binarization processing, and surface defect extraction processing. . The detection result of the surface defect can be displayed on a display such as a CRT or a printer.

Here, when the object to be inspected is, for example, a car body panel, the object to be inspected is press-molded into a predetermined shape after being cleaned with a cleaning oil. When such a surface defect inspection apparatus is used inline for such a press line, oil adheres to the surface to be inspected of the press-formed inspection object, and if the oil remains excessively, the surface is inspected. This causes erroneous detection of defects. That is, as shown in FIG. 10, the intensity of the diffuse reflection light of the illumination light on the surface to be inspected clearly increases in the part of the regular reflection light.
In contrast to the oil-free surface shown in FIG. 10A, the oil-coated surface shown in FIG. 10B has a reduced overall intensity and an increased intensity of the specularly reflected light. For this reason, if the oil is excessively adhered to the surface to be inspected, the intensity of light captured by the imaging means decreases, and the accuracy of detecting surface defects decreases.

On the other hand, in the surface defect inspection apparatus, before detecting the surface defect of the inspected surface from the received light image, the surface inspecting unit inspects the surface state of the inspected surface, and the oil state determining unit inspects the surface state of the inspected surface. Based on the surface state of the surface to be inspected from the surface inspection means, the adhesion state such as the amount of oil adhesion is determined, and in the oil countermeasure instruction means, the irradiation angle of the illumination light is determined based on the oil adhesion state from the oil state determination means. At least one of the change of the image pickup angle, the change of the imaging angle, and the control of the amount of oil adhering to the surface to be inspected is selected and output as a countermeasure instruction.

That is, in FIG. 10, the irradiation angle of the illumination light is α, the imaging angle is β, the intensity of the diffuse reflection light on the oil-free surface is Φ1, and the intensity of the diffuse reflection light on the oil-attached surface is In the case of Φ2, to accurately inspect the oil-adhered surface where the light receiving intensity of the imaging means decreases, the difference ΔΦ between the intensity Φ1 of the diffuse reflected light on the oil-free surface and the intensity Φ2 of the diffuse reflected light on the oil-applied surface is used. May be reduced, and the difference ΔΦ may be reduced by making the imaging angle β closer to the regular reflection angle (α) of the illumination light.

In the surface defect inspection apparatus, for example, when the oil adhesion amount determined by the oil state determination means is relatively small, the oil countermeasure instruction means changes the irradiation angle of the illumination light and / or changes the imaging angle. The change is output as a countermeasure instruction. More specifically, in FIG. 10B, a countermeasure instruction for increasing the illumination angle α of the illumination light and / or
Alternatively, a countermeasure instruction to reduce the imaging angle β is output. As a result, the imaging angle β approaches the regular reflection angle (α) of the illumination light, the light receiving intensity of the imaging unit increases, and the defect detection on the oil adhering surface is performed with high accuracy.

If the amount of oil adhering determined by the oil condition judging means is large, the oil countermeasure instructing means outputs removal of oil from the surface to be inspected as a countermeasure instruction, or the amount of oil adhering to the surface to be inspected is output. In addition to the control, the change of the irradiation angle α and the imaging angle β is output as a countermeasure instruction. At this time, the oil on the surface to be inspected is removed from the surface to be inspected before the press or from the surface to be inspected after the press when the surface defect inspection apparatus is used in a press in-line. It is possible to remove most of the oil, or to perform control to reduce the amount of oil adhesion. in this way,
If the countermeasure instruction for controlling the amount of oil adhering to the surface to be inspected is selected, it is possible to control the amount of oil adhering, which is the cause of erroneous detection. Defect detection is performed with high accuracy.

In the surface defect inspection apparatus according to a second aspect of the present invention, the wide-angle illumination means is directed upstream in the transport direction of the inspection object while the inspection object is moved in one direction by the inspection object transport means. In addition, the surface to be inspected is irradiated with illumination light, and the surface to be inspected is imaged by the imaging means on the upstream side. And
When the object to be inspected has moved by a predetermined distance, the wide-angle illumination unit irradiates the surface to be inspected with illumination light toward the downstream side in the transport direction of the object to be inspected, and an image of the surface to be inspected is captured by the imaging unit on the downstream side. In other words, if the object to be inspected is, for example, a vehicle body panel, the surface to be inspected is curved, and the inclined direction of the surface to be inspected is opposite before and after the transport direction, the surface to be inspected is divided into the front and rear inspection ranges. Then, after inspecting the second half of the surface to be inspected by the wide-angle illumination unit and the upstream imaging unit, the first half of the inspection surface is inspected by the wide-angle illumination unit whose direction has been changed and the downstream imaging unit. . This makes it possible to maintain the predetermined irradiation angle and the imaging angle of the illumination light with respect to the curved surface to be inspected without largely changing the heights of the illumination unit and the imaging unit.

In the surface defect inspection apparatus according to a third aspect of the present invention, in the illumination / imaging control means, the illuminating means and the imaging means are arranged such that the irradiation angle and the imaging angle of the illuminating light on the moving inspected surface become predetermined values. Control each angle and each height of the means. For such control, the position data of the inspection object moved by the inspection object transporting means and the previously input curved surface shape data of the inspection surface can be used, and the angles and heights of the illuminating means and the imaging means can be adjusted stepwise. Target or continuously. In the lighting / imaging control means, based on the countermeasure instruction from the previous oil countermeasure instruction means,
The angle and height of at least one of the illumination means and the imaging means are controlled, thereby changing the illumination angle and / or the imaging angle of the illumination light so that the defect detection on the oil-adhered surface can be accurately performed. .

In the surface defect inspection apparatus according to the fourth aspect of the present invention, when an image of the surface to be inspected is taken by an optical means, the luminance of the portion to which almost no oil adheres and the luminance of the portion to which oil adheres are determined. In addition, since the luminance also differs depending on the amount of oil adhered (the thickness of the oil film), the surface inspection means optically inspects the surface to be inspected and outputs the surface state at a luminance level. That is, the larger the amount of oil attached, the higher the luminance. Then, the oil adhesion state determination means determines the oil adhesion state of the surface to be inspected, that is, the degree of the oil adhesion amount, based on the luminance obtained from the surface inspection means and the relationship between the previously obtained luminance and the oil adhesion amount. The judgment result is sent to the oil measure instruction means.

In the surface defect inspection apparatus according to claim 5 of the present invention, the oil adhesion amount control means controls the oil adhesion amount on the surface to be inspected based on the countermeasure instruction from the oil countermeasure instruction means. In the defect detection of the inspected surface, the influence of excess oil which causes erroneous detection is reduced.

In the surface defect inspection apparatus according to claim 6 of the present invention, the oil adhering amount control means includes an oil squeezing roll and a pressing force control means, and the oil squeezing roll is brought into rotational contact with the surface to be inspected. The oil adhering excessively to the surface to be inspected is removed by squeezing, and at this time, the amount of oil adhering is changed by changing the pressing force of the oil squeezing roll against the surface to be inspected in accordance with the amount of oil adhering. Make it small and uniform.

In the surface defect inspection apparatus according to a seventh aspect of the present invention, the oil evaporation control means evaporates excess oil adhering to the surface to be inspected based on the countermeasure instruction from the oil countermeasure instruction means and the oil evaporation characteristic. Therefore, in the subsequent defect detection of the surface to be inspected, the influence of excess oil, which causes erroneous detection, is reduced.

In the surface defect inspection apparatus according to claim 8 of the present invention, the oil evaporation control means includes an air blowing means, an air flow rate switching means and a heat quantity switching means. Excessive oil adhering to the surface to be inspected is evaporated and removed. At this time, the amount of oil adhering is reduced and uniform by changing the amount of air from the blower and the temperature of the air according to the amount of oil adhering. Something.

In the surface defect inspection apparatus according to the ninth aspect of the present invention, the excess oil adhering to the surface to be inspected is wiped by the oil wiping means based on the countermeasure instruction from the oil countermeasure instruction means, and the inspection is performed thereafter. In detecting a defect on a surface to be inspected, the influence of excess oil which causes erroneous detection is reduced.

[0024]

According to the surface defect inspection apparatus according to the first aspect of the present invention, illumination light irradiation and imaging are performed on the inspected surface while moving the inspected object, and the inspected surface is inspected based on the received light image. When detecting surface defects such as unevenness of
By adopting the surface inspection means, oil state determination means and oil countermeasure instruction means, according to the oil adhesion state on the inspection surface,
By setting at least one of the change of the irradiation angle of the illumination light, the change of the imaging angle, and the control of the amount of oil adhering to the surface to be inspected as a countermeasure instruction, the influence of the excessive oil adhering to the erroneous detection can be reduced. This makes it possible to reduce as much as possible, thereby enabling highly accurate defect detection. Therefore, when oil is attached to the surface to be inspected, for example, even when the object to be inspected is a vehicle body panel and the surface to be inspected with oil is inspected in-line in a press line of the vehicle body panel. In addition, it is possible to perform the defect detection while reducing the influence of the excessively attached oil, and it is possible to stably perform the highly accurate defect detection.

According to the surface defect inspection apparatus of the second aspect of the present invention, the same effects as those of the first aspect can be obtained, and a wide angle illumination means is employed as the illumination means, and the upstream side is employed as the imaging means. By adopting the imaging means on the downstream side and the downstream side, it becomes very suitable for inspection of a curved surface to be inspected. For example, as in a car body panel of an automobile, the inclination direction of the surface to be inspected is reversed before and after in the transport direction. Even when the inspection target is oriented, the inspection surface is divided into front and rear portions in the transport direction to perform the inspection, so that the illumination on the inspection surface can be performed without largely changing the height of the illumination unit and the imaging unit. The light irradiation angle and the imaging angle can be maintained at predetermined values, which can contribute to improving the accuracy of defect detection.

According to the surface defect inspection apparatus according to the third aspect of the present invention, the same effects as those of the first and second aspects can be obtained, and further, since the illumination / imaging control means is employed, the inspection target surface is inspected. Is curved, high-accuracy defect detection can be performed while maintaining the irradiation angle and the imaging angle of illumination light on the surface to be inspected at predetermined values. By controlling the angle and the height of at least one of the illumination means and the imaging means based on the countermeasure instruction, when an image of the surface to be inspected with excessive oil is taken and image processing is performed, The edge detection level at the boundary between the portions is reduced, and the influence of excessive oil that causes erroneous detection is eliminated, so that the defect detection on the oil-adhered surface can be performed with high accuracy.

According to the surface defect inspection apparatus of the fourth aspect of the present invention, the same effects as those of the first to third aspects can be obtained. Surface inspection means for outputting at a level of oil, and oil adhesion state determination means for determining the oil adhesion state of the inspected surface based on the luminance obtained from the surface inspection means and the relationship between the previously obtained luminance and the oil adhesion amount. This makes it possible to accurately determine the oil adhesion state on the surface to be inspected with a very simple structure. As a result, the subsequent countermeasure instruction in the oil countermeasure instruction unit can be made more appropriate, which can contribute to higher accuracy of defect detection.

According to the surface defect inspection apparatus according to the fifth aspect of the present invention, the same effects as those of the first to fourth aspects can be obtained.
The excess oil on the surface to be inspected can be squeezed and removed early,
This can contribute to higher accuracy of the defect detection of the inspection surface performed thereafter.

According to the surface defect inspection apparatus according to the sixth aspect of the present invention, the same effect as that of the fifth aspect can be obtained, and in particular, the oil adhesion amount control means controls the oil pressing roll and the pressing force control. By adopting the means, the oil can be squeezed and removed in accordance with the amount of oil adhered to the surface to be inspected, and the amount of oil adhered to the surface to be inspected can be reduced and made uniform.

According to the surface defect inspection apparatus according to the seventh aspect of the present invention, the same effects as those of the first to sixth aspects can be obtained. Excess oil can be removed by evaporation at an early stage, which contributes to higher accuracy of a defect detection of a surface to be inspected performed later.

According to the surface defect inspection apparatus according to the eighth aspect of the present invention, the same effect as that of the seventh aspect can be obtained, and in particular, in the oil evaporation control means, the blowing means, the air flow rate switching means, and the heat quantity switching means. By employing the means, the oil can be evaporated and removed in accordance with the amount of oil adhered to the surface to be inspected, and the amount of oil adhered to the surface to be inspected can be reduced and made uniform.

According to the surface defect inspection apparatus according to the ninth aspect of the present invention, the same effects as those of the first to eighth aspects can be obtained, and the use of oil wiping means makes the surface to be inspected extra. Oil can be wiped off and removed at an early stage, which can contribute to higher accuracy of the subsequent detection of defects on the surface to be inspected.

[0033]

1 to 13 are views for explaining an embodiment of a surface defect inspection apparatus according to the present invention. The surface defect inspection apparatus according to this embodiment uses a body panel of a press-formed automobile as an object to be inspected, and inspects surface defects such as irregularities on the surface to be inspected in-line in a pressing process.

The surface defect inspection apparatus shown in FIG.
In D, the inspection object transporting means 1 such as a belt conveyor for transporting the inspection object P at a constant speed in the horizontal direction indicated by the arrow L in the drawing, and the upstream and downstream of the inspection object transporting means 1 in the transport direction. A wide-angle illuminating unit 2 as an illuminating unit that irradiates light at a predetermined irradiation angle α to an upper surface of a moving object P, that is, a surface to be inspected, which is capable of irradiating light.
Illumination light at an imaging angle β larger than the illumination angle α of the illumination light, which is disposed upstream and downstream in the transport direction of the inspection object with the wide-angle illumination means 2 interposed therebetween and faces the wide-angle illumination means 2 Upstream imaging means 3 and downstream imaging means 4 as imaging means for imaging reflected light from the light source, and inspection processing means 5 for detecting surface defects on the surface to be inspected based on the light receiving images obtained by the respective imaging means 3 and 4. It has a configuration with.

In the surface defect inspection apparatus, the inspection unit ED detects the position information of the surface to be inspected in the transport direction in the inspection section ED. Side position detecting means 6 and downstream position detecting means 7, and each position detecting means 6,
Based on the position data from 7, switching of the direction of illumination light irradiation by the wide-angle illumination means 2, switching between the two imaging means 3 and 4, and detection of surface defects by the inspection processing means 5 are performed.

The inspection processing means 5 includes an image input switching means 5A for switching image input from the upstream and downstream imaging means 3 and 4 according to signals from the upstream and downstream position detecting means 6 and 7, An image processing unit 5B that performs a process to detect a surface defect and a display unit 5C such as a CRT or a printer that outputs a detection result are provided.

Further, the surface defect inspection apparatus includes an inspection unit ED
In the above, the inspection surface type input means 8 for inputting the type of the inspection surface, and the inspection surface shape selection means 9 for selecting the curved surface shape data of the inspection surface corresponding to the type data from the inspection surface type input means 8 And controls the angles and heights of the illumination means and the imaging means based on the position data from the position detection means 6 and 7 and the curved surface shape data from the inspection surface shape selection means 9. An illumination / imaging control unit 10 is provided.

The inspected surface type input means 8 has various dimensions of various vehicle body panels as type data since the inspected body P is a vehicle body panel in this embodiment. CAD data used for the design can be used. The inspected surface shape selecting means 9 calculates the degree of curvature (angle, height) of the inspected surface in accordance with the input from the inspected surface type input means 8, and uses this as curved surface shape data for illumination / imaging control. Input to means 10. The illumination / imaging control unit 10 includes an illumination control unit 10A that controls the angle and height of the wide-angle illumination unit 2 and an imaging control unit 10B that controls the angle and height of both imaging units 3 and 4.
Irradiation angle α and imaging angle β of illumination light to the surface to be inspected
Is controlled to a predetermined value at all times, the wide-angle illumination means 2 and both imaging means 3 and 4 are controlled. The inspection surface shape selection means 9 and the illumination / imaging control means 10 can be incorporated in a host computer.

Further, the surface defect inspection apparatus includes an inspection unit ED
A surface inspection unit 51 that is arranged on the upstream side in the inspection object transport direction with respect to the upstream imaging unit 3 in the inspection object transport direction and that inspects the surface state of the inspection surface;
An oil state determining unit 52 that determines the state of oil adhesion based on the surface state of the surface to be inspected from the surface inspection unit 51, and an irradiation angle α of the illumination light based on the oil adhesion state from the oil state determining unit 52. An oil countermeasure instructing unit 53 is provided which outputs at least one of the change, the change of the imaging angle β, and the control of the oil adhesion amount on the surface to be inspected as a countermeasure instruction.

In this embodiment, the illumination / imaging control means 10 controls the angles and heights of the imaging means 3 and 4 based on the countermeasure instruction from the oil countermeasure instruction means 53. . The surface inspection means 51 includes an irradiating unit 51A for irradiating the inspection surface with illumination light, and an imaging unit 51B for imaging reflected light from the inspection surface. Inspect and output the surface condition at the luminance level. At this time, the luminance level tends to increase as the amount of oil adhesion, that is, the thickness of the oil film increases.
The oil adhesion state determination means 52 starts processing according to a signal from the position sensor 54 which detects the position of the moving inspection object P, and determines the luminance obtained from the surface inspection means 51 and the luminance obtained in advance and the oil adhesion amount. The state of oil adhesion on the inspection surface is determined based on the relationship.

The wide-angle illumination means 2 and the two image pickup means 3 and 4 in the above configuration will be described more specifically.

The wide-angle illuminating means 2 irradiates illumination light to the second half Pr in the transport direction of the surface to be inspected of the inspection object P between the wide-angle illuminating means 2 and the downstream-side imaging means 4. In step (1), illumination light is applied to the first half Pf in the transport direction of the surface to be inspected. At this time, the wide-angle illuminating means 2 irradiates the illumination light to two fixed positions on the upstream side and the downstream side in the transport direction of the inspection object. That is, the inspection of the surface defect is performed by passing the inspection object P to the two irradiation positions of the illumination light by the wide-angle illumination unit 2.

As shown in FIGS. 2 and 3, the wide-angle illuminating means 2 includes an illuminating means 12 for forming a linear illuminating light transverse to the inspection object transport direction (L), and an illuminating light from the illuminating means 12. Mirror reflecting means 13 for reflecting and irradiating the light, illumination rotation driving means 14 for rotating the mirror reflecting means 13 to change the irradiation direction of the illumination light, and illumination for integrally raising and lowering each means 12, 13, 14 Lifting drive means 15 is provided.

The illumination raising / lowering drive means 15 is provided with a drive mechanism 17 having a built-in motor (not shown) for vertically moving the slide body 16 on a beam (not shown) above the inspection object transporting means 1. At the lower end of the slide body 16, a frame (not shown) is provided.
It holds the mirror reflection means 13 and the illumination rotation drive means 14.

The irradiating means 12 includes four sets of an optical fiber cable 18 for transmitting light from a light source (not shown) and a light guide 19 having a built-in optical mechanism using a lens and condensing the light from the optical fiber cable 18 into a line. In addition, these are arranged in series, and are illuminated downward with linearly formed illumination light. As described above, light is transmitted from the light source installed at another fixed portion to the light guide 19 via the optical fiber cable 18 to form the illuminating unit 12 that forms linear illumination light. The structure of the part is simplified and the weight is reduced, and a wide range of surfaces to be inspected can be dealt with.

For the irradiating means 12, for example, a powerful light source such as a halogen lamp, a metal halide lamp, and a xenon metal halide lamp is used. Further, by using the light guide 19 having a relatively large width (about 200 to 300 mm), the number of the light guides 19 itself is reduced.

The mirror reflecting means 13 is a lightweight one mainly composed of a mirror body, is disposed below the irradiating means 12, that is, along the irradiation port of the illuminating light, and is provided with an illumination rotary driving means 14 provided on a frame. , And the other end is rotatably held by a bearing 20 also provided on the frame. Lighting rotation driving means 1
A motor 4 is used to rotate the mirror reflection means 13 around its longitudinal axis in a range of 180 degrees or more.

The wide angle illuminating means 2 having the above configuration is
The illumination control means 10A of the illumination / imaging control means 10 described above.
, The illumination rotation drive means 14 and the illumination elevation drive means 15 are driven in a predetermined direction, and the illumination light irradiation directions are switched with respect to the upstream and downstream sides of the test object transport direction, and the moving curved surface is moved. The irradiation direction (angle) and the height are adjusted so that the irradiation angle α is always set to a predetermined value with respect to the inspection target surface.

As shown in FIG. 2, both imaging means 3 and 4
As shown in FIG. 4, the plurality of CCD cameras 21 serving as cameras for receiving reflected light of the illumination light are arranged so as to face each other with substantially the same configuration.
And an imaging rotation drive unit 22 that rotates each CCD camera 21 to change the imaging direction, and an imaging elevation drive unit 23 that integrally moves each CCD camera 21 and imaging rotation drive unit 22 up and down. I have.

The imaging elevation drive means 23 includes a drive mechanism 25 including a motor 24 on a beam (not shown) above the inspection object transporting means 1 and a frame 26 driven up and down by the drive mechanism 25. The frame 26 holds a beam 27 arranged in a direction crossing the inspection object transport direction. One end of the beam 27 is held on one side of the frame 26 by the rotation driving means 22 for imaging, and the other end is rotatably held on the other end of the frame 26. And four C
The CD cameras 21 are mounted at equal intervals with the same imaging direction. The imaging rotation drive unit 22 uses motors, and simultaneously rotates the CCD cameras 21 together with the beam 27. As described above, by using the plurality of CCD cameras 21, the structures of the imaging units 3 and 4 are simplified and lightened, and a wide range of surfaces to be inspected can be dealt with.

The front and rear imaging means 3 and 4 having the above configuration
Is the imaging control unit 1 of the illumination / imaging control unit 10 described above.
0B, the imaging rotation drive unit 22 and the imaging elevation drive unit 23 are driven in a predetermined direction, and the imaging angle β is always set to a predetermined value with respect to the moving curved inspection surface. Adjustment of the imaging direction (angle) and height is performed.

Here, in the above configuration, the wide-angle illuminating means 2 has an irradiation angle α of 10 degrees or less with respect to the tangent line of the irradiation point of the illumination light because the surface to be inspected has a curved shape with the middle being the top region. The irradiation direction (angle) and the height are controlled so that the angle is low, while each of the imaging units 3 and 4 is controlled.
Is opposite to the irradiation position by the wide-angle illumination means 2, and the imaging angle β with respect to the tangent of the irradiation point of the illumination light is 10 to 3
The imaging direction (angle) and height are controlled so as to be in a range of 0 degrees, that is, an intermediate angle larger than the irradiation angle α.

The irradiation angle α and the imaging angle β as described above
By setting, it is possible to irradiate the illumination light at a low angle close to the side, and to capture irregularly reflected light due to a surface defect such as unevenness with high luminance.

This principle will be described with reference to FIG. When the wide-angle illuminating means 2 irradiates the inspection surface of the inspection object P with illumination light at the illumination angle α, the light reflected at the portion having no surface defect has a positive reflection angle (α) equal to the illumination angle α. It becomes reflected light. On the other hand, light reflected by the convex surface defect Q having the inclination angle θ is irregularly reflected light having a reflection angle (α + θ = β) larger than the irradiation angle α. In other words, among the illumination light irradiated at the predetermined irradiation angle α, the specular reflection light hitting a portion having no surface defect is not received by the imaging units 3 and 4,
Only the irregularly reflected light having a reflection angle (α + θ = β) larger than the irradiation angle α upon the surface defect is received by the imaging means 3 and 4. As a result, surface defects on the surface to be inspected can be captured with high luminance by the imaging means 3 and 4.

At this time, since the irradiation angle α of the illumination light by the wide-angle illumination means 2 is as low as 10 degrees or less with respect to the surface to be inspected, a high reflectivity due to a scene phenomenon in which the directivity of the reflected light distribution increases. Is obtained. This makes it possible to clearly distinguish the distribution of the reflected light at the angle of reflection by the scattering surface other than the defect portion and the distribution of the reflected light at the angle of reflection by the surface defect Q. Then, as shown in FIG. 6, if the irradiation angle α of the illumination light is 10 degrees or less, an image of the surface defect Q can be obtained with high luminance as shown in FIG. As shown in the figure, the smaller the irradiation angle α becomes, the more remarkable.

The sensitivity at the time of image pickup by the image pickup means 3 and 4 is highest when the image pickup angle β is an angle at which irregularly reflected light having a reflection angle α + θ is captured, but the reflected light has an angular distribution. Furthermore, since the regular reflection angle and the irregular reflection angle become closer as the inclination angle θ of the surface defect Q becomes gentler, the imaging angle β is set as far as possible from the reflection angle of the regular reflection light, and the reflection angle of the irregular reflection light (α + θ). ) Is preferred. For example, as shown in FIG. 7, by setting the imaging angle β in a range of 10 degrees to 30 degrees, a defect or the like can be captured with high luminance.

Incidentally, the CCD camera 21 of the imaging means 3, 4
Is installed at an angle with respect to the inspection surface of the inspection object P, so that the depth of field is shallow and the images at the front and rear ends may be blurred. In this case, while increasing the illuminance of the illuminating light and irradiating it strongly, the aperture of the CCD camera 21 is squeezed to increase the depth of field as much as possible, so that the defect angle is gentle and the height is very low. However, only this defective portion can be captured as a high luminance portion.

Next, the operation of the surface defect inspection apparatus having the above configuration will be described. As described above, the surface defect inspection apparatus inspects the object P, which is a vehicle body panel, in-line in the pressing process. Oil that may be a cause is attached, and the inspection is performed on the inspection surface in such a state. Therefore, in the surface defect inspection apparatus,
First, the surface condition of the surface to be inspected is inspected, and the inspection result is used in a process of detecting a surface defect by the inspection unit ED.
First, a process of detecting a surface defect by the inspection unit ED will be described.

When the inspection object P is carried in by the inspection object transport means 1, the inspection object P is detected by the upstream position detecting means 6, and the transport direction of the inspection object P from the wide angle illumination means 2 is detected. The second half Pr is irradiated with linear illumination light, and imaging by the upstream imaging means 3 is started. The irradiation of the illumination light and the imaging are started from the center of the panel in the second half Pr in the transport direction.

On the other hand, the type data of the inspected surface is input from the inspected surface type input means 8 to the inspected surface shape selecting means 9, and the inspected surface shape selecting means 9 checks the inspected surface corresponding to the type data. Is selected and input to the illumination / imaging control means 10, and the illumination / imaging control means 1 is selected.
With 0 (10A, 10B), control is performed such that the irradiation angle α of the illumination light of the wide-angle illumination unit 2 with respect to the inspection surface and the imaging angle β of the upstream imaging unit 3 with respect to the inspection surface are set to predetermined values. The irradiation direction (angle) of the wide-angle illuminating means 2 and the irradiation angle α and the imaging angle β of the illumination light with respect to the surface to be inspected are always maintained at predetermined values with the movement of the object P. The height, the imaging direction (angle) and the height of the upstream imaging means 3 are changed.

The image picked up by the upstream image pick-up means 3 is input to the image processing means 5B via the image input switching means 5A in the inspection processing means 5, where the image processing is performed. As shown in the processing flow of FIG. 8, when an image is captured in step S1, the image processing unit 5B performs edge extraction in step S2, performs binarization in step S3, and performs step S4. Performs a defect extraction process. The image from which the defect has been extracted is displayed on the display unit 5C.

Next, when the inspection of the second half Pr of the inspection object P in the transport direction is completed, the inspection object P that continues to move is detected by the downstream position detection means 7, and the detection signal is output from the inspection processing means 5. It is input to the input switching means 5A and the illumination / imaging control means 10. Thereby, the wide angle illumination means 2
The irradiation direction of the illumination light from is quickly switched to the downstream side, and the linear illumination light is transferred to the first half P of the inspection object P in the transport direction.
At the same time, the imaging by the downstream imaging means 4 is started. The forward irradiation of the illumination light and the imaging are started from the front end side of the panel in the first half part Pf in the transport direction.

Then, similarly to the previous inspection of the rear half Pr in the transport direction, the irradiation angle α and the imaging angle β of the illumination light with respect to the inspection surface are always maintained at predetermined values as the inspection object P moves. As a result, the irradiation direction (angle) and height of the illumination light by the wide-angle illumination unit 2 and the imaging direction (angle) and height of the downstream-side imaging unit 4 are changed. In the inspection processing means 5, the image input switching means 5A switches the input image from the upstream imaging means 3 to the input image from the downstream imaging means 4, and performs the image processing.

The control of the irradiation direction (angle) and height of the wide-angle illumination means 2 accompanying the movement of the object P, and the control of the imaging direction (angle) and height by each of the image pickup means 3 and 4 are as follows. 9, the imaging angle β and the imaging height ΔZ as shown in FIG.
2, and the irradiation angle α and the irradiation height ΔZ1 are controlled by switching stepwise in a pulsed manner. Such a control method is performed because the irradiation angle of the linear illumination light by the wide-angle illumination unit 2 and the imaging angle of the imaging units 3 and 4 both have a width (margin) at which the inspection can be performed. It is only necessary to control so as not to deviate to an impossible angle, and for the height,
Since the line-shaped illumination light has a certain allowable width (directivity), it is sufficient to control the illumination light to irradiate the surface to be inspected in accordance with the height that changes depending on the curved surface of the object P. is there. However, if the angles α and β and the heights △ Z2 and △ Z1 are linearly controlled along the surface of the inspection object P, a more optimal inspection can be performed. Of course.

As described above, in the surface defect inspection apparatus, the inspection object P is a vehicle body panel, the inspection surface is curved, and the inclination direction of the inspection surface is opposite before and after the transport direction. Even in this case, the inspection surface is divided into front and rear inspection ranges, and the wide-angle illumination unit 2 and the imaging unit 3 on the upstream side inspect the rear half Pr of the inspection surface, and then change the direction of the wide angle. The first half Pf of the surface to be inspected is inspected by the illumination means 2 and the imaging means 4 on the downstream side. Thereby, the predetermined irradiation angle α and the imaging angle β of the illumination light with respect to the curved inspection surface can be maintained without largely changing the heights of the wide-angle illumination unit 2 and the imaging units 3 and 4. Thus, in-line, while the test object P is being conveyed, a surface defect in the entire surface of the curved test surface can be detected with high accuracy and reliability.

By the way, as described above, the oil adheres to the inspection surface of the press-formed inspection object P, as shown in FIG.
When the light receiving image of the oil adhering surface as shown in FIG. 1A is image-processed, the boundary of the oil adhering portion is erroneously detected as an edge as shown in FIG. 11B. That is, as shown in FIG. 10, the intensity of the diffuse reflection light of the illumination light on the surface to be inspected clearly increases at the portion of the specular reflection light. Thus, on the oil-adhered surface shown in FIG. 10B, the overall intensity decreases and the intensity of the specularly reflected light portion increases. For this reason, if the oil is excessively attached to the surface to be inspected, the intensity of the light captured by the imaging units 3 and 4 decreases, and the detection accuracy of surface defects decreases.

In order to reduce such detection accuracy, in FIG. 10, the irradiation angle of the illumination light is α, the imaging angle is β, the intensity of the diffuse reflection light on the oil-free surface is Φ1, Assuming that the intensity of the diffuse reflection light on the surface is Φ2, in order to accurately inspect the oil-adhered surface where the received light intensity of the imaging means 3 and 4 decreases, the intensity of the diffuse reflection light Φ1 on the oil-free surface and the oil-adhered surface The difference ΔΦ from the intensity Φ2 of the diffuse reflection light may be reduced, and the difference ΔΦ may be reduced by making the imaging angle β closer to the regular reflection angle (α) of the illumination light.

Therefore, in the surface defect inspection apparatus, the surface inspection means 51 inspects the surface state of the surface to be inspected before the inspection, and the oil state determination means 52 inspects the surface inspection means 5.
1 is determined based on the surface state of the surface to be inspected from No. 1 and the oil adhesion state and distribution is determined by the oil countermeasure instructing means 53 based on the oil adhesion state from the oil state determination means 52.
The change of the imaging angle β is selected and output as a countermeasure instruction.

The countermeasure instruction from the oil countermeasure instruction unit 53 is taken into the imaging control unit 10B of the illumination / imaging control unit 10 in the inspection unit ED.
Based on the control characteristics of the imaging angle with respect to the luminance as shown in FIG.
4 is controlled. As a result, the imaging angle β approaches the regular reflection angle (α) of the illumination light, the light receiving intensity of the imaging units 3 and 4 increases, and the defect detection on the oil-adhered surface is performed with high accuracy. Further, when the imaging angle β is reduced, FIG.
A light receiving image as shown in FIG. 12A is obtained from the light receiving image shown in FIG.
As shown in FIG. 12B, the boundary between the oil-adhered portions is eliminated, and surface defects can be captured with high luminance.

As described above, in the surface defect inspection apparatus, even if the oil is excessively adhered to the surface to be inspected, the oil adhesion state is determined before the inspection, and the oil adhesion state is determined according to the adhesion state. By changing the imaging angle β of the imaging means 3 and 4, the inspection can be performed while minimizing the influence of excessive oil which causes erroneous detection, and surface defects can be detected with high accuracy and reliability in-line. It can be done.

In the above embodiment, the oil measure instructing means 5
Although the case where the imaging angle β is controlled to be small according to the countermeasure instruction from 3 has been described, the imaging angle β may be made closer to the regular reflection angle (α) of the illumination light by controlling the irradiation angle α of the illumination light to be large. And the imaging angle β
Of course, it is also possible to change both the irradiation angle α and the irradiation angle α.

Further, in the above-described embodiment, an example in which the inspection object transporting means 1 is entirely flat has been described. However, when the inspection target surface is a curved surface, the inspection object transporting means 1 A configuration is provided in which an inclined portion inclined downward toward the upstream at a position corresponding to the lower side of the side imaging means 3 and / or an inclined portion inclined downward toward the downstream at a position corresponding to the lower side of the downstream imaging means 4. With this configuration, it is also possible to enlarge the lowering limit of the imaging means 3 and 4 to easily secure a predetermined imaging angle β with respect to the curved surface to be inspected.

FIGS. 14 to 16 are diagrams for explaining another embodiment of the surface defect inspection apparatus according to the present invention. Note that the inspection unit ED of the surface defect inspection apparatus has basically the same configuration as that of the previous embodiment, and a description thereof will be omitted.

FIG. 14 is a view showing a press line including the surface defect inspection apparatus. A transfer apparatus 61 is provided on the right side of the drawing, on the upstream side of the test object transporting means 1, and an inspection unit. On the downstream side of the ED, an inspection object sorting device 62 including a robot or the like is provided. The inspection object classification device 62 receives the inspection results from the inspection processing means 5 of the inspection unit ED, and separates the inspection object P into non-defective products having no surface defects and defective products having surface defects.

The transfer device 61 carries in the test object P, which is a steel plate washed in a cleaning step (not shown), press-forms the test object P into a predetermined shape, and carries it out. As shown in the figure, a plurality of oil drawing rolls 63 for feeding the object P by rotating the object P, which is a steel plate, from above and below, and the pressing force of the oil drawing roll 63 against the surface to be inspected. , A conveyor 65, and a press device 66.

In the surface defect inspection apparatus of this embodiment, the oil squeezing roll 63 and the pressing force control means 64
An oil adhering amount control means 67 for controlling the oil adhering amount on the surface to be inspected based on a countermeasure instruction from the oil countermeasure instruction means 53 is provided. In addition, the surface inspection means 51 includes the transfer device 6
1 is arranged so as to inspect the surface to be inspected of the object P to be inspected carried out from 1. Further, the oil state determining means 52 and the oil measure instructing means 53 are incorporated in the host computer 68. The oil countermeasure instructing unit 53 outputs the adhesion amount control for removing excess oil to the oil adhesion amount control unit 67 as a countermeasure instruction, and the illumination / imaging control unit of the inspection unit ED described in the previous embodiment. The change of the illumination angle α and the imaging angle β of the illumination light can be output to the counterpart 10 as a countermeasure instruction.

The surface defect inspection apparatus having the above-described configuration optically inspects the surface state of the surface to be inspected by the surface inspection means 51 on the inspection object P after the press molding, and the oil state determination means 52 The adhesion state such as the amount and distribution of oil adhesion is determined, and the oil countermeasure instruction means 53 outputs a countermeasure instruction for removing excess oil to the oil adhesion amount control means 67.

In the oil adhering amount controlling means 67, the pressing force controlling means 64 outputs a command determined based on the characteristics of the luminance and the roll pressing force as shown in FIG. Then, the pressing force of the oil squeezing roll 63 against the surface to be inspected is changed. That is, when the amount of oil adhesion is larger than a predetermined value, the pressing force is increased, and when the amount of oil adhesion is smaller than the predetermined value, the pressing force is decreased. As a result, excess oil is squeezed and removed by the oil squeezing roll 63 from the inspection object P of the steel plate to be inspected next, and the amount of adhered oil is small and uniform. Therefore, in the subsequent detection of a defect on the surface to be inspected by the inspection unit ED, the influence of excess oil causing erroneous detection is greatly reduced.

It is also possible to inspect the state of oil adhesion of the steel plate inspection object P carried into the transfer device 61 by the surface inspection means 51 and to control the oil adhesion amount control means 67 based on the inspection result. Although it is possible, since the amount of adhering oil changes due to the press molding and the surface defect is inspected on the press-formed inspection object P, the inspection after the press molding is performed as in the above embodiment. By inspecting the surface to be inspected of the body P and controlling the oil adhering amount control means 67 to remove excess oil from the inspected body P of the steel plate to be inspected next, The effect of excess oil at the time of defect detection can be sufficiently reduced.

FIGS. 17 to 19 illustrate still another embodiment of the surface defect inspection apparatus according to the present invention.

FIG. 17 is a view showing a press line including the surface defect inspection apparatus. The basic configuration is the same as that of the embodiment shown in FIG. Further, there is provided an oil evaporation control means 69 for evaporating excess oil on the surface to be inspected based on a countermeasure instruction from the oil countermeasure instruction means 53 and an oil evaporation characteristic.

As shown in FIG. 18, the oil evaporating control means 69 blows air to the surface to be inspected.
0, an air volume switching unit 71 for changing the air volume from the blowing unit 70, and a heat amount switching unit 72 for changing the temperature of the air from the blowing unit 70. Blowing means 70
Is composed of, for example, a motor and a fan,
In this case, the air volume switching means 71 controls the motor in the air blowing means 70, and the heat volume switching means 72
Is for controlling a heater provided adjacent to the fan in the blowing means 70.

In the surface defect inspection apparatus having the above structure, the surface state of the surface to be inspected is optically inspected by the surface inspecting means 51 on the inspected object P after the press molding, and the oil state determining means 52 The state of adhesion, such as the amount and distribution of oil adhesion, is determined, and the oil countermeasure instruction unit 53 outputs a countermeasure instruction to the oil evaporation control unit 69 to remove excess oil.

In the oil evaporation control means 69, air is blown to the surface to be inspected by the air blowing means 70, and the air volume switching means 71 performs the air evaporation based on the relationship between the brightness and the air flow as shown in FIG. The amount is controlled, and the temperature of the air is controlled by the calorie switching means 72. That is, the larger the amount of oil adhered, the greater the amount of air and the temperature of the air. As a result, excessive oil is removed from the surface to be inspected by evaporation, and the amount of oil adhered is small and uniform. Therefore, in the subsequent detection of a defect on the surface to be inspected by the inspection unit ED, the influence of excess oil causing erroneous detection is greatly reduced.

FIGS. 20 and 21 are views for explaining still another embodiment of the surface defect inspection apparatus according to the present invention.

FIG. 20 is a view showing a press line including the surface defect inspection apparatus. The basic configuration is the same as that of the embodiment shown in FIG. Further, an oil wiping unit 73 for wiping excess oil on the surface to be inspected based on a countermeasure instruction from the oil countermeasure instruction unit 53 is provided. This oil wiping means 73 is provided in FIG.
As shown in FIG. 1, a plurality of oil wiping rolls 74 held so as to be able to move up and down with respect to the surface to be inspected are provided.

The surface defect inspection apparatus having the above-described structure optically inspects the surface state of the surface to be inspected by the surface inspection means 51 on the inspection object P after the press molding, and the oil state determination means 52 The adhesion state, such as the amount and distribution of oil adhesion, is determined, and the oil measure instruction means 53 outputs a measure instruction to the oil wiping means 73 to remove excess oil.

The oil wiping means 73 lowers the oil wiping roll 74 when the oil adhesion amount is larger than a predetermined value, and makes the oil wiping roll 74 come into contact with the surface to be inspected while rotating. Wipe off excess oil on the surface to be inspected. As a result, the amount of oil adhered to the surface to be inspected is small and uniform. Therefore, in the subsequent detection of defects on the surface to be inspected by the inspection unit ED,
The effect of excess oil, which causes erroneous detection, is greatly reduced.

Here, in the embodiment shown in FIGS.
A case in which the countermeasure instruction output from the oil countermeasure instruction unit 53 is a change in the imaging angle β with respect to the imaging control unit 10B will be described. In the embodiment illustrated in FIGS. The case where the instruction is to squeeze out excess oil to the oil adhesion amount control means 67 will be described with reference to FIG.
In the embodiment shown in FIG. 19 to FIG. 19, the case where the countermeasure instruction output from the oil countermeasure instructing means 53 is the removal of excess oil by evaporation to the oil evaporation control means 69 will be described.
In the embodiment shown in FIG. 7, the case where the countermeasure instruction output from the oil countermeasure instruction unit 53 is wiping and removal of excessive oil with respect to the oil wiping unit 73 has been described. As an example, as shown in FIG. 22, an illumination control unit 10A, an imaging control unit 10A,
The oil control unit 67, the oil evaporation control unit 69, and the oil wiping unit 73 are all provided, and the countermeasure instruction unit 53 can selectively output a countermeasure instruction to these units.

That is, when the surface to be inspected is imaged by the surface inspection means 51, as shown in FIG. 23, the luminance varies depending on the amount of oil adhesion (the thickness of the oil film), and as the amount of oil adhesion increases, Brightness tends to increase. Therefore, as shown in FIG. 23, the degree of the oil adhesion state is determined in advance, such as a normal oil film area, a multi-oil film area, and an excessive oil film area. It is determined to which region the state corresponds, and the result of the determination is sent to the oil measure instructing means 53. Then, the oil measure instruction means 53
Accordingly, a countermeasure instruction most suitable for avoiding erroneous detection due to oil is performed. That is, the illumination control unit 10A, the imaging control unit 10A, the oil adhesion amount control unit 67, the oil evaporation control unit 6
The countermeasure instruction is output to one or a plurality of units selected from the group 9 and the oil wiping unit 73. This makes it possible to significantly reduce the influence of excessively attached oil in the subsequent detection of defects on the surface to be inspected by the inspection unit ED.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view showing one embodiment of a surface defect inspection apparatus according to the present invention.

FIG. 2 is a perspective view illustrating an inspection object transporting unit, a wide-angle illumination unit, and upstream and downstream imaging units;

FIG. 3 is a perspective view illustrating a structure of a wide-angle lighting unit.

FIG. 4 is a perspective view illustrating the structure of an imaging unit.

FIG. 5 is a diagram illustrating the principle of surface defect inspection.

FIG. 6 is a graph showing a relationship between an irradiation angle of illumination light by a wide-angle illumination unit and luminance of a received image.

FIG. 7 is a graph showing a relationship between an imaging angle by an imaging unit and a detection level (luminance ratio) of a received light image.

FIG. 8 is a flowchart illustrating image processing performed in an inspection processing unit.

FIG. 9 is a diagram illustrating an example of control of an angle and a height position of a wide-angle illumination unit and an imaging unit.

FIG. 10A illustrates the intensity characteristics of scattered and reflected light of illumination light on a surface to be inspected to which no oil is attached, and the intensity of scattered and reflected light of illumination light on the surface to be inspected to which oil is attached. FIG. 7B is a diagram illustrating characteristics.

FIGS. 11A and 11B are a view showing a light receiving image of a surface to be inspected to which oil has adhered, and a view showing an image after binarization processing; FIGS.

12A is a diagram illustrating a received light image in a state where an imaging angle is reduced with respect to FIG. 11, and FIG. 12B is a diagram illustrating an image after binarization processing;

FIG. 13 is a graph illustrating control characteristics of an imaging angle with respect to luminance.

FIG. 14 is a schematic explanatory view showing another embodiment of the surface defect inspection apparatus according to the present invention.

FIG. 15 is an explanatory diagram showing the inside of the transfer device shown in FIG. 14;

FIG. 16 is a graph showing the relationship between the luminance of the surface to be inspected by the surface inspection means and the pressing force of the oil drawing roll.

FIG. 17 is a schematic explanatory view for explaining still another embodiment of the surface defect inspection apparatus according to the present invention.

18 is an explanatory diagram showing the inside of the oil evaporation control means shown in FIG.

FIG. 19 is a graph showing the relationship between the brightness of the surface to be inspected by the surface inspection means and the amount of air blown by the air blowing means.

FIG. 20 is a schematic explanatory view for explaining still another embodiment of the surface defect inspection apparatus according to the present invention.

FIG. 21 is an explanatory diagram showing the inside of the oil wiping unit shown in FIG. 20;

FIG. 22 is a block diagram illustrating still another embodiment of the surface defect inspection apparatus according to the present invention.

FIG. 23 is a graph showing the relationship between the thickness of the oil film and the brightness when the surface to be inspected is imaged by the surface inspection means.

24A and 24B are diagrams illustrating the principle of illumination light irradiation and imaging in a conventional surface defect inspection apparatus, and are an explanatory diagram when a planar light source is used, and a description when a linear light source is used. FIG.

[Explanation of symbols]

 P Inspection object 1 Inspection object conveying means 2 Wide-angle illumination means (illumination means) 3 Upstream imaging means (imaging means) 4 Downstream imaging means (imaging means) 5 Inspection processing means 10 Illumination / imaging control means 10A Illumination control Means 10B Imaging control means 51 Surface inspection means 52 Oil state determination means 53 Oil countermeasure instruction means 67 Oil adhesion amount control means 63 Oil squeezing roll 64 Pressure contact force control means 69 Oil evaporation control means 70 Blowing means 71 Air volume switching means 72 Heat quantity switching Means 73 Oil wiping means

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kazuhide Itami 2 Takaracho, Kanagawa-ku, Yokohama, Kanagawa Prefecture Inside Nissan Motor Co., Ltd. (72) Inventor Kazuo Yamada 2 Takaracho, Kanagawa-ku, Yokohama, Kanagawa Nissan Motor In-house F-term (reference) 2F065 AA49 BB15 CC11 DD12 FF04 FF44 GG02 HH12 HH13 HH14 JJ03 JJ05 JJ08 JJ09 JJ26 LL01 LL03 LL13 LL30 MM03 QQ04 QQ25 QQ32 SS13 TT08 2G051 AA37 AB01 CA01 AB01 CA01 AB01 DA06 EA11 EB01 EB02 FA10

Claims (9)

[Claims] 1. An inspection object transporting means for transporting an inspection object in one direction, an illumination means for irradiating illumination light on a surface to be inspected of a moving inspection object at a predetermined illumination angle, Imaging means for imaging reflected light of the illumination light at an imaging angle larger than the irradiation angle; inspection processing means for detecting a surface defect on the surface to be inspected based on a light reception image from the imaging means; Surface inspection means for inspecting the surface condition of the surface to be inspected, which is arranged on the upstream side in the transport direction of the object to be inspected, and an oil state for judging the adhesion state of the oil based on the surface condition of the surface to be inspected from the surface inspection means Determining means for outputting at least one of a change in the illumination angle of the illumination light, a change in the imaging angle, and a control of the amount of oil adhering to the surface to be inspected, based on the oil adhering state from the oil state judging means. Equipped with oil measures instruction means A surface defect inspection device characterized by the above-mentioned. 2. The illumination device according to claim 1, wherein the illumination unit is capable of irradiating the illumination light on the upstream side and the downstream side in the transport direction of the inspection object, and illuminates the inspection surface of the moving inspection object at a predetermined irradiation angle. The wide-angle illumination means for irradiating, and the imaging means are arranged on the upstream side and the downstream side in the transporting direction of the inspection object with the wide-angle illumination means therebetween, and the irradiation angle of the illumination light is opposed to the wide-angle illumination means. 2. The surface defect inspection apparatus according to claim 1, wherein the upstream and downstream imaging units capture the reflected light of the illumination light at a larger imaging angle. 3. An angle and a height of each of the illuminating means and the imaging means are controlled so that the irradiation angle and the imaging angle of the illuminating light with respect to the moving inspected surface have predetermined values.
3. The apparatus according to claim 1, further comprising an illumination / imaging control unit that controls an angle and a height of at least one of the illumination unit and the imaging unit based on a countermeasure instruction from the oil countermeasure instruction unit. Surface defect inspection equipment. 4. A surface inspection means for optically inspecting a surface to be inspected and outputting a surface state at a luminance level, and an oil adhering state determination means for determining a luminance obtained from the surface inspection means and a predetermined value. The surface defect inspection apparatus according to any one of claims 1 to 3, further comprising means for determining an oil adhesion state of the surface to be inspected based on a relationship between the obtained luminance and an oil adhesion amount. 5. An oil adhering amount control which is disposed upstream of the illumination means and the image pickup means in the transport direction of the inspected object and controls the oil adhering amount on the inspected surface based on a countermeasure instruction from the oil countermeasure instructing means. 5. The method according to claim 1, further comprising:
A surface defect inspection device according to any one of the above. 6. The oil adhering amount control means includes an oil squeezing roll that is in rotational contact with the surface to be inspected, and a pressing force control unit that controls a pressing force of the oil squeezing roll against the surface to be inspected. The surface defect inspection apparatus according to claim 5, wherein 7. An oil disposed upstream of the illumination means and the imaging means in the transport direction of the inspection object and evaporating oil on the inspection surface based on a countermeasure instruction from the oil countermeasure instruction means and an oil evaporation characteristic. The surface defect inspection apparatus according to any one of claims 1 to 6, further comprising an evaporation control unit. 8. An air evaporation control unit, wherein the oil evaporation control unit blows air to the surface to be inspected, an air volume switching unit for changing the amount of air from the air blowing unit, and a heat amount switching unit for changing the temperature of the air from the air blowing unit. The surface defect inspection apparatus according to claim 7, further comprising a unit. 9. An oil wiping unit disposed upstream of the illumination unit and the imaging unit in the transport direction of the inspection object and wiping oil on the inspection surface based on a countermeasure instruction from the oil countermeasure instruction unit. The surface defect inspection apparatus according to any one of claims 1 to 8, wherein