JP2012083211A - Surface state inspection device, surface state inspection method and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately detect a fault regardless of the shape of a surface of an inspection object and the fault.SOLUTION: Two or more kinds of pattern lights having at least cross-shaped and ring-shaped irradiation patterns produced on a surface of an inspection object are emitted on the surface of the inspection object from a light-emitting portion 601. The pattern lights are emitted on the surface of the inspection object while scanning in a predetermined direction. On the other hand, an imaging portion 602 shoots an image including the irradiation pattern produced by the emitted pattern lights, and an image processing portion 603 detects a fault on the surface of the inspection object on the basis of changes of the shape of the irradiation pattern included in the shot image.

Description

  The present invention relates to a surface state inspection apparatus, a surface state inspection method, and a program suitable for use, for example, for optically inspecting the surface of an inspection object.

  Conventionally, various methods for optically inspecting irregularities on the surface of various industrial products such as the surface state of a painted surface of a vehicle by non-contact and non-destructive methods have been developed. For example, according to the technology described in Patent Document 1, first, a striped pattern illumination is performed on the surface of the inspection object so that a bright / dark boundary is generated. When the light / dark boundary is moved with respect to the surface of the inspection object, a phenomenon occurs in which the light / dark is reversed at the uneven defect portion, and the light / dark image being picked changes to detect the uneven defect.

JP 2001-349716 A

Nature, Vol. 441, p. 946, 2006

  However, in the technique disclosed in Patent Document 1 described above, depending on the inclination angle of the concavo-convex defect present on the surface of the inspection object, there is a case where the shadow due to the concavo-convex defect does not occur and inversion does not occur in light and dark. is there. Also, if the surface of the inspection object is a curved surface, moving the light / dark boundary line also causes the light / dark boundary line to bend according to the curvature of the inspection surface, and this boundary line curve is erroneously detected as an uneven defect. Resulting in. As described above, there is a problem in that the accuracy of defect detection is lowered depending on the shape of the inspection surface and the concavo-convex defect.

  An object of the present invention is to make it possible to detect a defect with high accuracy regardless of the surface of the inspection object and the shape of the defect.

  The surface condition inspection apparatus of the present invention includes an irradiation unit that irradiates the surface of the inspection object while scanning a plurality of types of light having different irradiation pattern shapes generated on the surface of the inspection object in a predetermined direction; An imaging unit that captures an image including an irradiation pattern generated by the light irradiated by the irradiation unit, and a surface of the inspection object based on a change in the shape of the irradiation pattern included in the image captured by the imaging unit And detecting means for detecting a defect.

  ADVANTAGE OF THE INVENTION According to this invention, it can prevent that the precision of defect detection falls with the shape of a test | inspection surface or an uneven | corrugated defect, and a defect can be detected accurately.

It is a perspective view which shows the external appearance structural example of the surface state inspection apparatus in embodiment. It is a figure which shows an example of the irradiation pattern when pattern light overlaps with a convex defect. It is a figure which shows an example of the irradiation pattern by a linear pattern light. It is a figure which shows an example of the irradiation pattern in the case of a square shape and a cross shape. It is a figure which shows an example of the irradiation pattern in the case of a cross shape and a ring shape. It is a block diagram which shows the function structural example of the surface state inspection apparatus which concerns on embodiment. It is a flowchart which shows an example of the detection processing procedure of an uneven | corrugated defect. It is a figure which shows an example of the irradiation pattern and light source which were arranged in the array form.

Hereinafter, a surface condition inspection method according to an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a perspective view showing an external configuration example of the surface state inspection apparatus 10 according to the present embodiment.
In FIG. 1, when pattern light is irradiated from the light source 1 to the inspection surface 2, an irradiation pattern 6 is projected on the inspection surface 2. The projected irradiation pattern 6 is photographed by a camera 3 such as a CCD camera, for example, and image processing is performed by a personal computer (PC) 4 connected to the camera 3.

  When a moving device 5 such as a loader or a robot to which the light source 1 and the camera 3 are attached is moved in the direction of the arrow, the irradiation pattern 6 moves so as to trace the inspection surface 2. And the unevenness | corrugation defect of the test | inspection surface 2 is detectable by discriminating in the computer 4 the change of the pattern shape of the irradiation pattern 6 image | photographed with the camera 3. FIG.

  Here, the detection process of the concavo-convex defect on the inspection surface 2 will be described. In the case where the inspection surface 2 is flat with no irregularities, even if the inspection surface 2 is scanned, the shape of the irradiation pattern 6 does not change and is constant, and no defect is detected.

  FIG. 2 shows an example of illumination of a convex defect by the surface condition inspection apparatus 10 shown in FIG. 1, and FIG. 2 (a) shows an irradiation when a part of the pattern light overlaps the convex defect of the inspection surface 2. It is a figure which shows an example of a pattern and a captured image. 2 shows an example in which, as shown in FIG. 1, an irradiation pattern 6 is generated on the inspection surface 2 by irradiating pattern light from the upper left side by an angle α, and the irradiation pattern 6 is scanned rightward. ing.

  As shown in FIGS. 2 (a) and 2 (b), when the pattern light is irradiated while being tilted from the vertical direction of the inspection surface 2, the irradiation pattern 22 and the irradiation pattern 22 depend on the height of the convex defect and the irradiation angle of the pattern light. An overlapping area with the top of the convex defect 21 is determined. Therefore, the captured image 23 of the irradiation pattern 22 has a shape in which a part of the original pattern shape is missing. When the irradiation pattern 22 is scanned rightward with respect to the convex defect 21, no irradiation pattern is generated on the flat portion of the inspection surface 2 as shown in FIGS. An area, that is, a shadow area 24 of the convex defect 21 is formed. Even in this case, the captured image 23 has a shape change in which a part of the original pattern shape is missing. As described above, it is possible to detect a defect on the inspection surface 2 from the shape change of the captured image 23 caused by the irradiation pattern 22.

  When the inspection surface 2 includes a curved surface shape, when the irradiation pattern 6 scans the inspection surface 2, the inspection surface 2 is irradiated from the irradiation angle α and the light source 1 according to the curvature of the inspection surface 2. The optical path length d to the irradiation pattern 6 changes. Thereby, when the pattern light from the light source 1 is not parallel light, the size of the irradiation pattern 6 generated on the inspection surface 2 changes according to the change in the optical path length d.

  Further, since the optical path length of each light spot forming the pattern light changes depending on the irradiation angle α, regardless of the parallelism of the pattern light from the light source 1, the region of the inspection surface 2 irradiated with the pattern light changes. The shape of the irradiation pattern 6 changes. Thus, the shape of the irradiation pattern 6 changes according to the curvature of the inspection surface 2. However, such a shape change is different from the shape change of the irradiation pattern 22 due to the minute convex defect 21 shown in FIG. 2, and a part of the irradiation pattern is lost as the irradiation light moves. It does not appear as a large shape change in the partial area. Due to the difference in the shape change of the irradiation pattern, even when the inspection surface is a curved surface, it is possible to accurately detect a minute defect.

  In the present embodiment, the case where the light source 1 and the camera 3 are moved is shown. On the other hand, the light source 1 and the camera 3 may be fixed and the inspection surface 2 may be moved. In this case, although not shown, for example, a conveying device such as a belt conveyor serves as the moving means. In the present embodiment, an example in which the camera 3 is installed in an oblique direction with respect to the irradiation pattern 6 has been described. On the other hand, the position of the camera 3 is not limited to the oblique direction with respect to the irradiation pattern 6, and may be installed in the vertical direction, for example, as long as the pattern shape change of the irradiation pattern 6 can be imaged. .

Next, the shape of the irradiation light pattern suitable for detecting defects on the inspection surface 2 will be described.
FIG. 3 is a diagram illustrating an example of an irradiation pattern and a captured image by linear pattern light. Here, the positional relationship between the light source and the camera is the same as that shown in FIG.
As shown in FIG. 3A, when the linear irradiation pattern 32 is generated in parallel with the array of the pixels 34 of the camera 3, the irradiation pattern image 33 captured by the camera 3 is aligned in the array of the pixels 34. Lined up.

  When the irradiation pattern 32 moves and overlaps the convex defect 31, as shown in FIG. 3B, the position where the irradiation pattern 32 is generated shifts according to the height of the convex defect 31. In addition, since the irradiation pattern 32 is not generated in the shadowed area of the convex defect 31, the irradiation pattern image 33 is changed by four pixels as compared with the case where there is no convex defect 31.

  Further, when the irradiation pattern 32 is inclined with respect to the arrangement of the pixels 34, as shown in FIG. 3C, more pixels than the case where the irradiation pattern 32 is irradiated in parallel to the arrangement of the pixels 34. 34 is used to form an irradiation pattern image 33. As a result, the change of the irradiation pattern image 33 due to the convex defect 31 is only for three pixels as shown in FIG. As described above, when the contour portion of the irradiation pattern 32, that is, the light / dark boundary portion is parallel to the arrangement of the pixels 34, the shape change due to the convex defect of the irradiation pattern image 33 occurs more greatly, and defect detection is performed. Sensitivity can be increased.

Next, the shape of the irradiation pattern suitable for detecting a defect on the inspection surface when the contour portion of the irradiation pattern is parallel to the pixel array of the camera to be imaged will be described.
FIG. 4 is a diagram illustrating an illumination example when the irradiation pattern has a quadrangular shape and a cross shape. The positional relationship between the light source and the camera is the same as that shown in FIG.

  FIG. 4A shows an illumination example of the convex defect 41 on the inspection surface 2 when the irradiation pattern 42 has a quadrangular shape. When the irradiation pattern 42 overlaps a part of the convex defect 41, as described above, the bright and dark boundary region of the irradiation pattern 42 that overlaps the convex defect 41 and the portion of the region that is a shadow of the convex defect 41, A shape change occurs. On the other hand, when the irradiation pattern 42 is further moved to completely cover the convex defect 41, the shape change of the captured image 43 occurs only in the area of the shadowed area of the convex defect 41 as shown in FIG. Absent. For this reason, the amount of change in the shape of the entire captured image 43 decreases, and the defect detection sensitivity decreases.

  On the other hand, when the shape of the irradiation pattern 42 is a cross shape, as shown in FIGS. 4C and 4D, the cumulative shape change of the captured image 43 that occurs while the irradiation pattern 42 scans the convex defect 41. The amount increases as compared with the case where the irradiation pattern 42 is rectangular. In this way, the irradiation pattern 42 can be improved in defect detection sensitivity in the cross shape rather than the square shape.

  In the present embodiment, the defect detection process on the inspection surface 2 has been described using convex defects. However, the defect that can be detected in the present embodiment is not limited to the convex defect, and the concave defect can be detected by the same detection process.

  Next, the relationship between the inclination angle of the concavo-convex defect, the shape of the irradiation light pattern, and the detection sensitivity will be described. As shown in FIG. 1, when the pattern light emitted from the light source 1 is applied to the inspection surface 2 at an angle α, the angle formed between the inclined surface of the convex defect on the inspection surface and the inspection surface is an angle (90− In the case of exceeding α), the pattern light is irradiated onto the convex defect, and a shadow region due to the convex defect occurs. In this case, the cross-shaped irradiation pattern 52 shown in FIG. 5A has higher defect detection sensitivity than the ring-shaped irradiation pattern not parallel to the pixel arrangement shown in FIG. 5B. Can do.

  On the other hand, when the angle formed between the inclined surface of the convex defect and the inspection surface is equal to or smaller than the angle (90-α), even if the pattern light is irradiated to the convex defect, a shadow region due to the convex defect does not occur. FIG. 5C shows a pattern in which the normal vector of the contour portion of the cross-shaped irradiation pattern 52 and the orthogonal projection vector of the gradient vector of the inclined surface of the convex defect 51 onto the inspection surface 2 are parallel or perpendicular. It is a figure which shows the example of illumination with which the light is irradiated to the convex defect 51. FIG.

  As shown in FIG. 5C, the orthogonal projection vector of the gradient vector of the inclined surface of the convex defect 51 onto the inspection surface 2 and the normal vector of the contour portion of the irradiation pattern 52 are in a parallel or vertical relationship. . For this reason, when the contour portion of the irradiation pattern 52 (in this case, the contour parallel to the convex defect 51) does not overlap the convex defect 51, no change in shape occurs in the captured image 53. That is, the shape change occurs only when the contour portion of the irradiation pattern 52 is irradiated on the convex defect 51. As a result, the cumulative shape change amount of the captured image 53 that occurs while the irradiation pattern 52 scans the convex defect 51 is small, and the detection sensitivity of the convex defect 51 is low.

FIG.5 (d) is a figure which shows the example of illumination of the convex defect 51 in case the irradiation pattern 52 is ring shape.
As shown in FIG. 5D, the directions of the normal vectors of the contour portions of the ring-shaped irradiation pattern 52 are all different depending on the location. In this case, as the irradiation pattern 52 is scanned, the normal vector of the outline of the irradiation pattern 52 and the orthogonal projection vector of the gradient vector of the inclined surface of the convex defect 51 on the inspection surface 2 do not become parallel. Therefore, a region of the irradiation pattern 52 that overlaps the convex defect 51 always occurs. As a result, as the irradiation pattern 52 is scanned, the shape of the irradiation pattern 52 always changes in the region of the irradiation pattern 52 that overlaps the convex defect 51.

  As described above, when the irradiation pattern 52 has a ring shape, since the contour portion of the irradiation pattern 52 is not parallel to the pixel arrangement of the camera 3, the defect detection sensitivity decreases. However, since there is no dead zone in the shape change of the irradiation pattern 52 while the irradiation pattern 52 scans the convex defect 51, the accumulated shape change amount during the scanning is large, and for the convex defect having various shapes and inclination angles. Detection sensitivity can be increased.

  As described above, it has been described that the irradiation pattern 52 preferably has a ring shape or a disk shape in which the directions of the normal vectors of the contour portion of the irradiation pattern 52 are all different depending on the location. However, the shape of the irradiation pattern 52 is not particularly limited to the ring shape, and may be, for example, an X shape, a triangular shape, a hexagonal shape, or the like. In this case, the direction of the irradiation pattern 52 is adjusted so that the moving direction of the irradiation pattern 52 and the direction of the normal vector at an arbitrary point in the outline portion of the irradiation pattern 52 are continuously or intermittently different. For this reason, while the irradiation pattern 52 scans the convex defect 51, the orthogonal projection vector of the gradient vector of the inclined surface of the convex defect 51 onto the inspection surface and the normal vector of the contour portion of the irradiation pattern 52 are not parallel. Further, the irradiation pattern 52 is applied to the convex defect 51. Thus, as in the case of the ring shape described above, since there is no dead zone in the shape change of the irradiation pattern 52, it is possible to increase the detection sensitivity for convex defects.

  Further, as described above, with respect to the concave defect, when the angle formed by the inclined surface of the concave defect and the inspection surface 2 is equal to or larger than the angle (90 + α), the detection sensitivity can be increased by using the ring-shaped irradiation pattern. it can. Also in this case, the irradiation pattern is not limited to the ring shape, and may be, for example, an X shape, a triangular shape, a hexagonal shape, or the like.

FIG. 6 is a block diagram illustrating a functional configuration example of the surface state inspection apparatus 10 according to the present embodiment.
In FIG. 6, a light emitting unit 601 functions as the light source 1 that irradiates pattern light. When pattern light is irradiated from the light emitting unit 601 to the inspection surface 2 of the inspection object, an irradiation pattern is formed on the inspection surface 2. Generated. The imaging unit 602 captures the generated irradiation pattern with the camera 3 and sends the received light image to the image processing unit 603. At this time, the irradiation angle of the pattern light irradiated from the light emitting unit 601 with respect to the inspection surface 2 is in a range of 0 ° <α <90 °. The image processing unit 603 performs binarization processing and the like on the captured captured image, detects an uneven defect portion of the inspection target based on a shape change of the irradiation pattern generated along with the scanning of the pattern light, The result is stored in the storage unit 604.

  The storage unit 604 is a memory that stores information on the shape of the irradiation pattern and information on the detected uneven defect portion. The arm control unit 605 controls the moving device 5 to which the light source 1 and the camera 3 are attached to move in the direction of the arrow in FIG. 1 while scanning the pattern light from the light source 1 at a predetermined speed. . A control unit 606 controls the operation of the entire apparatus.

  The light emitting unit 601 includes an illumination source including, for example, a fluorescent lamp, an incandescent lamp, and a light emitting diode, and a light shielding mask for forming pattern-shaped irradiation light. The light-shielding mask is a light-transmitting sheet, plastic plate, acrylic plate, glass plate, etc., which is coated with a non-light-transmitting sheet other than a pattern-shaped window, or a non-light-transmitting paint. It is made up of things. Furthermore, the light source 1 which irradiates pattern light can be formed by installing a light shielding mask in front of the illumination source. A configuration in which pattern light is emitted from an illumination source without using a light shielding mask may be used.

  Note that the illumination source in the present embodiment may be a laser light source. In this case, since the laser is coherent light, the spread of the light can be suppressed, and even if the distance between the light source 1 and the inspection surface 2 slightly varies, the change in the size of the irradiated pattern light becomes small. Thereby, it can suppress that the precision of the defect detection in the surface direction of the test | inspection surface 2 deteriorates. Moreover, since the irradiation light intensity is high, the contrast of light and dark at the boundary of the pattern light can be increased, and the sensitivity of defect detection can be improved.

  The pattern shape of the pattern light applied to the inspection surface 2 is set to a pattern corresponding to the uneven defect to be detected when the shape and size of the uneven defect to be detected is determined. As described above, the angle formed between the inclined surface of the convex defect and the inspection surface 2 exceeds the angle (90-α), or the angle formed between the inclined surface of the concave defect and the inspection surface 2 is less than the angle (90 + α). In this case, it is preferable that the irradiation pattern light has a cross-shaped irradiation pattern.

  On the other hand, when the angle formed between the inclined surface of the convex defect and the inspection surface 2 is equal to or smaller than the angle (90-α), or when the angle formed between the inclined surface of the concave defect and the inspection surface 2 is equal to or larger than the angle (90 + α). The pattern light to be irradiated preferably has a ring shape or a disk shape. Also, when it is desired to detect irregularities having various shapes while maintaining a certain level of detection sensitivity, it is preferable that the irradiation pattern light has a ring shape or a disk shape.

  In addition, the pattern surface irradiated to the test | inspection surface 2 may be two or more instead of one. For example, as shown in FIG. 8A, pattern light may be irradiated so that the irradiation pattern 81 is arranged in an array on the inspection surface 2. In this way, by arranging a plurality of irradiation patterns 81 in a triangular lattice in two rows and moving them in the direction of the arrows, it is possible to irradiate pattern light to a wide area of the inspection surface 2 without omission, and to reduce the time required for inspection. It can be expected to shorten significantly.

  In the example shown in FIG. 8A, an example in which a plurality of one type of irradiation pattern is generated is shown. However, this example shows a case where the shape of the concavo-convex defect is grasped to some extent, or a concavo-convex of a specific shape. This is a case where a defect is detected. On the other hand, there are various irregularities on the inspection surface, and the shape is not specified. Therefore, in this embodiment, two or more types of irradiation patterns are used. For example, as shown in FIG. 8B, pattern light is irradiated so that irradiation patterns 82 having different shapes are arranged in an array on the inspection surface 2. In this case, when the ring-shaped and cross-shaped irradiation patterns 82 are arranged in a triangular lattice pattern and moved in the direction of the arrow for one period, the respective pattern lights are irradiated into the moving range without omission. Thereby, it can be expected that defects of various shapes are detected with high accuracy while maintaining high detection sensitivity. In addition, the combination of the shape of the irradiation pattern 82 may be another combination.

  In order to form a ring-shaped or cross-shaped irradiation pattern as described above, for example, a two-dimensional photonic crystal surface emitting laser is used. Irradiation patterns such as a ring shape and a cross shape can be formed by a two-dimensional photonic crystal arrangement method as disclosed in Non-Patent Document 1. That is, when the holes of the two-dimensional photonic crystal are arranged in a square shape, ring-shaped pattern light can be formed. In addition, in a square array of holes in the two-dimensional photonic crystal, if the holes are not provided in a cross shape, cross-shaped pattern light can be formed.

  Further, when the irradiation patterns are arranged in an array, as shown in FIG. 8C, the same two-dimensional photonic crystal surface emitting laser 83 or a plurality of two types of two-dimensional photonic crystals with different arrangements are used. A two-dimensional photonic crystal surface emitting laser 83 is arranged in an array. Thus, by generating an irradiation pattern from the two-dimensional photonic crystal surface emitting laser 83, it is possible to accurately detect defects of various shapes. Further, the laser light source in the present embodiment is not particularly limited to one oscillation wavelength, and a plurality of laser light sources having different oscillation wavelengths may be used. By using a plurality of laser light sources having different oscillation wavelengths as the light source 1, it is possible to compensate when the reflected light intensity of the pattern light is reduced due to the material of the inspection object, and the defect detection accuracy is deteriorated. Can be suppressed.

FIG. 7 is a flowchart showing an example of the processing procedure for detecting irregularities by the image processing unit 603 and the like.
First, the process is started by irradiating the inspection surface 2 with pattern light from the light source 1. In step S701, the arm control unit 605 starts the movement of the moving device 5 so as to scan at a predetermined speed. Next, in step S <b> 702, the imaging unit 602 captures from the camera 3 a received light image obtained by imaging the irradiation pattern projected on the inspection surface 2.

  Next, in step S <b> 703, the image processing unit 603 performs binarization processing on the captured received light image to detect the outline of the irradiation pattern, and temporarily stores information on the obtained irradiation pattern shape in the storage unit 604. In step S704, the arm control unit 605 determines whether or not the movement distance set in advance as one cycle has been reached. If the result of this determination is that one cycle has not been reached, the process returns to step S702.

  On the other hand, if one cycle has been reached as a result of the determination in step S704, in step S705, the image processing unit 603 performs difference detection using information on the shape of the irradiation pattern for one cycle temporarily stored in the storage unit 604. Do. In the difference detection, the difference is detected by comparison with the shape of the irradiation pattern in the case where the uneven defect portion does not exist. In step S706, as a result of the difference detection, a difference area having a difference in the shape of the irradiation pattern is determined, and the difference areas are numbered.

  Next, in step S707, with respect to the numbered difference areas, as described above, a partial defect in the shape of the irradiation pattern or a region in which a local shape change has occurred is determined as an uneven defect portion, and the pattern light The position of the concavo-convex defect portion is determined by calculating backward from the scanning speed. In step S708, the position information of the determined uneven defect portion is stored in the storage unit 604, and the process is terminated. Since each of the above processes is performed at a processing speed that follows the scanning speed of the pattern light, the scanning of the pattern light is continuously performed without being interrupted every cycle.

  As described above, according to the present embodiment, the inspection surface is irradiated with the pattern light generated in a cross shape and the pattern light generated in a ring shape in a predetermined direction. Thereby, it can prevent that the precision of defect detection falls by the shape of a test | inspection surface or an uneven | corrugated defect, and can detect a defect accurately.

(Other embodiments)
The present invention can also be realized by executing the following processing. That is, software (program) that realizes the functions of the above-described embodiments is supplied to a system or apparatus via a network or various storage media, and a computer (or CPU, MPU, or the like) of the system or apparatus reads the program. It is a process to be executed.

601 Light emitting unit, 602 imaging unit, 603 image processing unit, 604 storage unit, 605 arm control unit, 606 control unit

Claims (10)

Irradiation means for irradiating the surface of the inspection object while scanning a plurality of types of light having different shapes of irradiation patterns generated on the surface of the inspection object in a predetermined direction;
Photographing means for photographing an image including an irradiation pattern generated by the light irradiated by the irradiation means;
A surface condition inspection apparatus comprising: a detection unit configured to detect a defect on a surface of the inspection object based on a change in shape of an irradiation pattern included in an image captured by the imaging unit.   The surface state inspection apparatus according to claim 1, wherein the irradiation unit irradiates light that generates an irradiation pattern having a shape including at least a contour portion parallel to the pixel array of the imaging unit.   The said irradiation means irradiates the light which produces | generates the irradiation pattern of the shape from which the direction of the normal vector in the arbitrary points of an outline part differs continuously or intermittently. Surface condition inspection device.   The surface condition inspection apparatus according to claim 1, wherein the irradiation unit irradiates at least light that generates a cross-shaped irradiation pattern and light that generates a ring-shaped irradiation pattern.   The said irradiation means irradiates the surface of the said test target object with multiple types of light so that the irradiation pattern produced | generated may be arranged in an array form, The any one of Claims 1-4 characterized by the above-mentioned. Surface condition inspection device.   The surface condition inspection apparatus according to claim 1, wherein the irradiation unit irradiates light from a laser light source.   The surface condition inspection apparatus according to claim 6, wherein the irradiation unit irradiates light from a plurality of laser light sources having different oscillation wavelengths.   The surface condition inspection apparatus according to claim 6, wherein the irradiation unit irradiates light from a light source using a two-dimensional photonic crystal surface emitting laser. An irradiation step of irradiating the surface of the inspection object while scanning a plurality of types of light having different shapes of irradiation patterns generated on the surface of the inspection object in a predetermined direction;
A photographing step of photographing an image including an irradiation pattern generated by the light irradiated in the irradiation step;
And a detection step of detecting a defect on the surface of the inspection object based on a change in the shape of the irradiation pattern included in the image captured in the imaging step. An irradiation step of irradiating the surface of the inspection object while scanning a plurality of types of light having different shapes of irradiation patterns generated on the surface of the inspection object in a predetermined direction;
A photographing step of photographing an image including an irradiation pattern generated by the light irradiated in the irradiation step;
A program causing a computer to execute a detection step of detecting a defect on a surface of the inspection object based on a change in shape of an irradiation pattern included in an image captured in the imaging step.

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