JPH04204314A - Surface defect inspection instrument - Google Patents

Abstract

PURPOSE:To accurately detect the position, height and depth of a surface defect by illuminating light which has either of the intensity or the wavelength changed in sequence, great to small, along a light emission face onto an inspected face and receiving the reflected light. CONSTITUTION:For example, when several fluorescent lamps as light sources 13 are arranged in a box and light intensity distribution is uniformly changed by a light filter to one direction of a light emission face 13a formed by a diffusion screen, a light illumination area S which has illumination change corresponding to intensity change in the direction of an arrow mark A1 appears in an inspected face 11, it is trapped into a view F of a video camera 14 and a light receiving picture 15 is obtained which is changed in brightness, strong to weak, in the direction of an arrow mark A2 corresponding to the arrow mark A1. If there is a defective portion 12 on the inspected face 11, light is changed in positive reflection direction. That is, if the defective portion 12 is protruded, it is originally brighter than that in other areas in the direction of the arrow mark A2 tending from a bright area to a dark area and gets dark after passing therethrough. So, if a change in the brightness of the defective portion 12 in the picture 15 is analyzed, the position, height and depth can be detected.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a surface defect inspection device for inspecting surface defects present on the painted surface of a smooth plate having a curved shape such as the body of an automobile. The present invention relates to an apparatus that irradiates a surface to be inspected with light and inspects surface defects based on information contained in the reflected light from the surface to be inspected.

(Prior Art) In a manufacturing line for vehicles such as automobiles, painting of vehicle bodies is generally performed at a painting station provided in the manufacturing line.

At such stations, after the car body has been painted, inspection for defects caused by this painting has traditionally been carried out by
This was done through human visual inspection. In such an inspection, the inspector must discover minute defects from the coating surface, which places a large neurological burden on the inspector and is forced to perform physically demanding work.

In view of these circumstances in inspection of paint defects, we have developed a system that irradiates light onto the surface of an object to be inspected, projects the reflected light onto a screen, and automatically detects surface defects on the surface to be inspected based on the sharpness of the projected image. A surface inspection device has been proposed that detects the surface of the surface (for example, see Japanese Patent Application Laid-Open No. 62-233710).

If this surface inspection device is applied to the inspection 8 of paint defects on vehicle bodies, the above-mentioned paint defects can be detected automatically, and the inspector can be freed from the conventional visual inspection work.

By the way, when applying the above-mentioned surface inspection technology using light irradiation to automatic inspection of car body coatings, as shown in FIG. Apply linear (or spot) light to the coating surface 1.
A conceivable device is to create a light irradiation area that is sufficiently smaller than the camera field of view F of the video camera 3, which will be described next, and to receive reflected light from this light irradiation area by the video camera 3.

In this device, the light reception image created by the video camera 3 is as shown in Fig. 10, in which the light reflected from the light irradiation area of the coating surface 1 enters the camera field of view F (see Fig. 9). The light-irradiated area of the coating surface 1 is captured as a bright line image 6 in the light-receiving image 5 which is dark as a whole. Then, in this light irradiation area, there is a defective part 7 (9th part) of the coating.
(see figure), the direction of specular reflection of light changes at the defective part 7 of the coating, and the light that would normally be reflected and enter the camera field of view F if it were not for the defective part 7 changes. It won't fit into F. For this reason, a black defective portion 7 (see FIG. 10) appears in the above-mentioned bright line image 6.

Therefore, the defective portion 7 can be detected by identifying the defective portion 7 that appears black using image processing technology. Further, according to this device, since the coating surface 1'' is irradiated narrowly in a linear manner, the amount of irradiated light is small, and the direction of specular reflection at the defective portion 7 of the light incident on the light irradiated area changes, causing the video camera 3 There is a clear difference in the amount of light entering the defective area 7 and the non-defective area, and even minute defects can be detected.

However, with narrow light irradiation as in the above device, the light irradiation area is too small with respect to the camera field of view F, and on the other hand, the defective part 7 that can be captured by the video camera 3 is the light irradiation area (i.e. 1. Since it is only within or near the line image 6) in image 5, surface inspection can only be performed using only a part of the camera field of view F, resulting in a problem of poor inspection efficiency.

Furthermore, when the surface to be inspected is the body of a vehicle such as an automobile, the inspection is carried out while moving the light source 2 and video camera 3 shown in FIG. 9 along the surface of the vehicle body using a robot device (not shown). Ru.

However, in this case, since the car body consists of many curved surfaces, if the inspection point moves to these curved surfaces, the linear illumination shape formed on the car body surface by the light source 2 will be distorted. The line image 6 among the received light images of No. 3 is also the first one.
As shown in Figure 1, there will be distortion, and in extreme cases, the camera will deviate from the field of view F.

For this reason, it is difficult to properly inspect the coating surface 1 on the body of a vehicle such as an automobile, and the control of the robot device is complicated in order to ensure that the line image 6 always falls within the camera field of view F. There was a problem.

In order to solve the above-mentioned difficulties, as shown in Fig. 12, the coating surface 1 is illuminated widely by a light source 2' in an area equal to or larger than the camera field of view F, and this wide light irradiation area is It is conceivable that the video camera 3 captures the image.

However, when the coating surface 1 is irradiated widely in this way, the amount of irradiated light increases significantly, which causes light halation at the defective area 7, making it impossible for the video camera 3 to clearly capture the minute defective area 7. .

For example, the light beam L2 from the light source 2' is reflected by the coating surface 1, and the reflected light enters the light receiving surface of the video camera 3. However, assuming that there is no defect 7 in the light irradiation area, the amount of light entering the light receiving surface is Since the light is the same in all parts, the received light image is bright all over.

On the other hand, if there is a defect 7 in the light irradiation area, the direction of specular reflection of the light incident on the light irradiation area changes at this defect 7, and the amount of incident light on the light receiving surface portion corresponding to the defect 7 changes. It should decrease and appear as a black dot in the received light image.

However, since the light source 2' widely irradiates the coating surface 1 as described above, the light L3 from other parts of the light source 2'.
The light is reflected by the defective parts 7, 7 and enters the light receiving surface where the amount of light is supposed to decrease.

Therefore, the brightness in the received light image does not decrease significantly,
Therefore, when the defective part 7.7 is minute, there is less difference in brightness between the defective part 7, 7 and the other part, and it is difficult to identify the defective part 7, 7 even by image processing. It becomes difficult.

Figure 1 (a) is a device that solves this problem.
, A light capable of emitting light whose luminous intensity m gradually changes from large to small in one predetermined direction along the light exit surface 13a (the magnitude of the luminous intensity is expressed by the length of the line m) as shown in (b). Irradiation means 13
The light irradiated from the light irradiation means 13 and the surface to be inspected 11
The light reflected by the light is received by the light receiving means 14, and the received image is converted into a video signal, and then this video signal is differentiated.If the level of this differential signal is above a predetermined value, a surface defect is detected. It is possible to consider a technology that recognizes that there is such a thing.

According to the second technique, there is an exit surface 13 on the surface to be inspected 11.
Light irradiation means 13 whose luminous intensity changes with respect to one direction of a
Therefore, when a defect 12 exists on the surface to be inspected 11, this defect causes a large disturbance in the intensity of the reflected light, and this is differentiated from the video signal output from the video signal generating means. By detecting the value, it is possible to easily and accurately determine the presence or absence of a surface defect.

(Problems to be Solved by the Invention) However, although it is possible to recognize the position where a surface defect exists depending on the technique described above, it is difficult to recognize the height or depth of the surface defect.

In particular, when it comes to paint defects on automobile bodies, we automatically polish the defective area for convex defects and the area around the defective area for concave defects. It is necessary to detect the height or depth of the defective portion in advance.

Further, in order to efficiently inspect such a defective portion, it is desirable to detect the height or depth of the defective portion at the same time as detecting the position of the defective portion.

The present invention was made in view of the above circumstances, and an object of the present invention is to provide a surface defect inspection device that can accurately and efficiently detect the height or depth of a surface defect existing on a surface to be inspected. It is something.

(Means for Solving the Problems) The surface defect inspection device of the present invention converts a received light image from a surface to be inspected into a video signal, and obtains a
This method is characterized in that the height or depth of a surface defect on the surface to be inspected is calculated based on size information of the surface defect and information on changes in luminous intensity or wavelength.

That is, this device includes a light irradiation means for irradiating the surface to be inspected with light whose luminous intensity or wavelength gradually changes from large to small along the light exit surface, and a light irradiation means for irradiating the surface to be inspected with light whose luminous intensity or wavelength gradually changes from large to small along the light exit surface, a light-receiving surface that receives reflected light, and a video signal converting means that converts a light-receiving image from the light irradiation area received by the light-receiving surface into a video signal, the surface being inspected based on the video signal. A surface defect inspection device for detecting surface defects on a surface, the video signal being inputted,
calculation means for calculating the height or depth of the surface defect based on the size information of the surface defect on the surface to be inspected and the change information of the luminous intensity or wavelength in this one surface defect obtained from the video signal; It is characterized by being prepared.

(Function) According to the above configuration, a light source is used as the light irradiation means, which emits light whose luminous intensity or wavelength gradually changes from large to small along the light exit surface. If there is a surface defect on the surface, the light intensity or wavelength of the incident light entering the video signal converting means from the surface defect portion changes due to a change in the direction of light reflection at that portion. This luminous intensity or wavelength changes depending on the curvature of the defect. Therefore, by analyzing this luminous intensity or wavelength change information, it is possible to know the curve shape of the surface defect.

However, for surface defects with different curvature radii but with similar curved shapes, the luminous intensity or wavelength change information described above will be the same, so this can be determined by analyzing the surface defect size information in addition to the luminous intensity or wavelength change information. It becomes possible to calculate the height or depth of surface defects. - Therefore, according to the above configuration, the height or depth of the surface defect is calculated based on the size information of the surface defect carried in the video signal and the information on the change in luminous intensity or wavelength.

□ Since the video signal information from the light-receiving image of the inspected surface is used in this way, the height or depth of the surface defect can be detected at the same time as the position of the surface defect, which improves inspection efficiency. It is also preferable.

(Example) Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

First, the principle of the present invention will be explained in FIGS. 1(a) and 1(b).
).

FIG. 1(a) shows a case where the surface to be inspected 11 has a convex defect portion 12, and FIG. 1(b) shows a case where the surface to be inspected 11 has a concave defect portion 12.

In FIG. 1(a) and FIG. 1(b), the light source 13 as a light irradiation means is configured to measure the luminous intensity (represented by the length of line m) of the light emitted from the light emitting surface 13a or the emitted light. It changes from strong to weak in one direction shown by the arrow A1 on the surface. The light source 13 irradiates the light irradiation area S of the surface to be inspected 11 with light emitted from the a-plane 13a.

As described above, the light emitted from the light emitting surface 13a of the light source 13 has the following characteristics:
The luminous intensity variation is marked with respect to one direction of a. Therefore, a light irradiation area S having a change in illuminance is generated on the surface to be inspected 11 in the direction corresponding to the arrow Al, which corresponds to the change in light intensity. Then, the light is captured in the camera field of view F of the video camera 14 as a video signal generating means, which has the camera field of view F included in this light irradiation area S.

Therefore, as shown in FIG. 2(a) and FIG. 2(b), in the light reception image 15 of the video camera 14 that captures the reflected light of such a light irradiation area S, the light from the light exit surface 13a of the light source 13 is The brightness of the emitted light changes from strong to weak in the direction shown by arrow A2, corresponding to the direction shown by arrow A1, in which the luminous intensity of the emitted light changes from strong to weak.

In such a state, if a defective portion 12 occurs on the surface to be inspected 11, the direction of specular reflection of light from the light source 13 changes at this defective portion 12. Due to this change in the direction of specular reflection of light, the received light image 15 of the video camera 14 has an illuminance of arrow A2.
In the state where the brightness changes in the direction shown by , the state of change in brightness of the defective portion 12 is different from that of other parts.

As shown in FIG. 1(a), the defective portion 12 is
In the case of a convex shape, the exit surface 13 of the light source 13
The light from the position 16 where the luminous intensity is large primarily hits the surface 12a of the defective portion 12 facing the exit surface 13a, the direction of specular reflection changes, and a portion of the light is incident on the video camera 14. However, only the light from the position 17 where the luminous intensity of the exit surface 13a is relatively low enters the surface 12b on the back side of the defective portion 12 with respect to the exit surface 18a, and the video camera 14
, almost no reflected light from the rear surface 12b of the defective portion 12 enters.

Therefore, the light-receiving image 15 of the video camera 14 is
As shown in Figure (a), if the defective part 12 is convex,
In the direction indicated by the arrow A2, which goes from a bright spot to a dark spot in the light-receiving image 15 of the video camera 14, the defective part 12 is initially brighter than the other parts, and after passing this bright part, it becomes darker than the other parts.

Incidentally, the brightness of the defective portion 12 in the light-receiving image 15 of the video camera 14 changes depending on the height of the defective portion 12 and the curved shape of the outer surface. In other words, if the defective portion 12 is a convex portion 121 with a small height, the slope thereof will be gentle;
It is specularly reflected on the negative side 12a and the video camera 14
Since the incident angle of the light incident on this negative side 12a becomes small, the brightness of this one side 12a becomes slightly brighter. Similarly, the other side 12b of this convex portion 121
The brightness will be a little dark.

On the other hand, if the defective portion 12 is a convex portion 122 with a large height, the slope thereof is steep, and the light that is specularly reflected at the negative side 12a and enters the video camera 14 is
Since the incident angle at 2a becomes large, this one side 1
The brightness of 2a is extremely bright. Similarly,
The brightness of the other side 12b of the convex portion 122 is extremely dark.

Therefore, by analyzing the change in brightness of the defective part 12 in the light-receiving image 15 of the video camera 14, the height of the defective part 12 can be detected.

However, as shown in FIG. 4, the convex portions 12 [i
, 127 , 128 , if their curve shapes (inclinations) are equal, these convex portions 126 , 127 ,
The convex portions 126 , 127 , 128 of the light beam 13 b that is specularly reflected on one side of 128 and enters the video camera 14
Since the angles of incidence on the defective portions 12 are equal to each other, when detecting the height described above, it is necessary to analyze the size (outer diameter) of the defective portion 12 in addition to the change in brightness.

Note that when the defective portion 12 is concave, the light from the position 16 of the exit surface 13a of the light source 13 where the luminous intensity is high mainly hits the surface 12c of the defective portion 12 on the side opposite to the exit surface 13a. The direction of specular reflection changes, and a part of it enters the video camera 14. However, the defective part 12
The surface 12d opposite to the surface 12c includes the exit surface 1.
Only light enters from a position where the luminous intensity of 3a is relatively low,
The video camera 14 is provided with the above-mentioned opposite surface 1 of the defective portion 12
Almost no light enters from 2d.

Therefore, the light-receiving image 15 of the video camera 14 is
As shown in Figure (b), if the defective part 12 is concave,
In the direction indicated by an arrow A2 from a bright area to a dark area of the light-receiving image 15 of the video camera 14, the defective part 12 first becomes darker than other areas, and after passing this dark area, it becomes brighter than other areas.

Even when the defect 12 is concave, the depth can be determined by analyzing the change in brightness of the defect 12 in the light-receiving image 15 of the video camera 14 and the size (outer diameter) of the defect 12. can be calculated. The video camera 14 outputs a video signal that changes according to changes in the brightness of the received light image 15.

Thereafter, the video signal output from the video camera 14 is manually input to the calculation section 18. The signal level on one scanning line in the vicinity of the defective part 12 of the video signal input to the calculation unit 18 is as shown in FIG. 5(a) when the defective part 12 is convex; When the defective portion 12 is concave, it has a shape as shown in FIG. 5(b).

The video signal is subjected to differential processing in this arithmetic unit 18, and then the absolute value is taken.

Therefore, the video signals having signal levels as shown in FIGS. 5(a) and 5(b) are converted into signals having three peaks as shown in FIG. 6. Of these three peaks, peak A and peak C are
It represents the external shape of peak B.
indicates a portion where the signal level changes significantly in the region of the defective portion 12.

From these peaks A and C, the position of the surface defect and the size (outer shape) of this defective portion 12 can be detected.

In addition, the calculation unit 18 detects the brightness of the defective part 12 in the received light image based on the signal level of the video signal at the position of the defective part 12, and combines this detected brightness with the defect obtained as described above. The height (depth) of the defective portion 12 is calculated from the size (outer shape) of the portion 12.

The above-mentioned position of the defective part 12 and height (depth) of the defective part 12 are outputted from this calculation section 18 and sent to a predetermined defective part processing device or the like.

Next, FIGS. 7 and 8 show an example configuration using the above-mentioned principle.
This will be explained using figures.

The vehicle body paint inspection station 20 is equipped with a robot device 21 mounted on a pedestal B, as shown in FIG.

The robot device 21 includes a light irradiation means 23 corresponding to the light source 13 (see FIGS. 1(a) and 1(b)) on its tip arm 22, and a light irradiation means 23 (see FIG. 1(a) and FIG. 1(b)), and the video camera 14 (first
A CCD camera 24 corresponding to the one shown in FIG. 1(a) and FIG. 1(b) is attached via a support fitting 25. These light irradiation means 23 and CCD camera 24 of the robot device 21 are used to detect the coating surface 27 (the surface to be inspected 11 in FIGS. 1(a) and 1(b) of the vehicle body 26 carried into the coating inspection station 20). (equivalent to) is traced, and at that time, the light irradiated by the light irradiation means 23 is reflected by the coating surface 27 on the surface of the vehicle body 26 and enters the CCD camera 24.

In addition, in such a coating defect inspection using the light irradiation means 23 and the CCD camera 24, the host computer 31
The robot controller 32 is driven by the command given by. The resulting signal from the robot controller 32 is then sent to the robot device 21.

In the robot device 21, a built-in actuator (not shown) operates, and thereby the robot device 21
The light irradiation means 23 and the CCD camera 24 are arranged so that the light irradiation means 23 and the CCD camera 24 trace the surface of the vehicle body 26.
While moving the D camera 24, the CCD camera 24
The video signal obtained by the image processing processor 33
Output to.

In the image processing processor 33, as already mentioned,
After amplifying the video signal, it is differentiated, and the scanning line of the video signal where the differential signal exceeds a preset threshold value and the timing on this scanning line are checked, and the data is transmitted to the host computer 31. and analyze it. As a result, the coordinates of the position of the defective part 12 and whether the defective part 12 is convex or concave are detected.

Next, data regarding the brightness of the defective portion 1 of the video signal, the size of the defective portion 12 obtained as described above, and whether it is convex or concave is sent to the host computer 31.
It is transmitted to and analyzed, and the height (depth) of the defective portion 12 is calculated.

Based on the detection results obtained through such operations, the vehicle body 2
Repair is carried out according to the unevenness of the paint defect 12 existing on the painted surface of B. As described below, when the defect 12 is convex, the protruding part is scraped off to a small size and the defect is removed. When 12 is concave, the coating film is scraped off over a relatively wide range including the defective portion 12.

This repair can be done manually, but usually
This is automatically performed by the robot device 21 or a repair robot device (not shown) provided separately.

As shown in FIG. 8, the light irradiation means 23 includes a plurality of fluorescent lamps 42 (not particularly limited to fluorescent lamps 42) installed inside a box 41.

A front filter 43 is installed in front of these fluorescent lamps 42, and a diffusion screen 44 is further installed so as to cover the entire surface of this optical filter 43.

The optical filter 48 adjusts the luminous intensity distribution of the light emitted from the fluorescent lamp 42 to the light exit surface 1 formed by the diffusion screen 44.
This is for changing the light in a negative direction with respect to one direction of 3a, and the light at a point having the same x-coordinate value of the xy coordinate set on the light exit surface 13a as shown in FIG. The transmittance of light is the same, and the transmittance of light at points having different y-coordinate values is different. With this, the seventh
The light irradiation area S (FIG. 1(a) and FIG. 1(
b)) is formed.

On the other hand, the diffusion screen 44 diffuses the light transmitted from the optical filter 43 and prevents areas of low illuminance from occurring on the coating surface 27 by arranging the fluorescent lamps 42 at intervals. be.

Note that the change (gradient) of the light intensity applied to the light irradiation means 23 is as follows:
As shown by the dotted line in FIG. 7, the light irradiation means] controller 3
4, and according to instructions from the post computer 31,
It can also be created by changing the voltage applied to each fluorescent lamp 42 using the light irradiation means/controller 34. In this case, the pre-filter 43 can be omitted.

In the above paint defect inspection device, the paint inspection station 2
As the painted vehicle body 26 is brought into the vehicle, inspection work for paint defects begins. That is, the robot device 21 is controlled by the robot controller 32, and the light irradiation means 23
The light irradiation means 23 and the CCD camera 2 are kept in an integral relationship, and the light irradiation means 23 and the CCD camera 2 are placed on the surface of the vehicle body 28.
4 along the surface shape of the vehicle body 26 with an appropriate distance between them.

At this time, the light irradiation means 23 illuminates the camera field of view F as explained in FIG. 1(a) and FIG.
The coating surface 27 of the vehicle body 26 is irradiated with light whose luminous intensity distribution changes uniformly in one direction.

Therefore, on the coating surface 27, the illuminance distribution changes uniformly in one direction, as shown in FIGS. 1(a) and 1(b).
A light irradiation area S shown in is formed. Furthermore, in the CCD camera 24 into which the reflected light from the light irradiation area S is incident, a light reception image 15 whose brightness uniformly changes in one direction corresponding to the luminous intensity distribution of the light irradiation means 23 is created. Become.

Therefore, if a defective portion 12 occurs on the surface to be inspected 11, the direction of specular reflection of light from the light source 13 changes at that portion.
As described in the principle explanation of FIGS. 1(a) and 1(b), FIGS. 2(a) and 2(b), for example, when the defective portion 12 is convex, , video camera 1
As shown in FIG. 2(a), in the light reception image 15 of No. 4, the defective part 12 is initially larger than other parts in the direction indicated by the arrow A2 from the bright part to the dark part of the light reception image 15 of the video camera 14. It becomes brighter, and after this brighter part it becomes darker than other parts.

In addition, if the defective portion 12 is concave, the second
As shown in Figure (b), the light reception image 1 of the video camera 14
In the direction shown by the arrow A2 from the bright part to the dark part of 5, the defective part 12 first becomes darker than other parts, and after passing this dark part, it becomes brighter than other parts.

The video camera 14 outputs a video signal that changes according to changes in the brightness of the received light image 15.

When this video signal is input to the image processing processor 33, the image processing processor 33 detects C due to the presence of the defective portion 12.
A scanning line of the video signal in which the differential signal of the video signal output from the CD camera 24 exceeds a preset value, the timing at which the differential signal exceeds the threshold value on this scanning line, and the sign of the differential signal near this timing. Detect changes in As a result, the defective part 12 in the light-receiving image 15
The position, size, and uneven shape of the defective portion 12 are detected. This detection data and the tip arm 22 of the robot device 21
Store the location in memory. When repairing the defective portion 12, the contents stored in this memory are taken out and the defective portion 12 is repaired as described above.

In this manner, the defective portion 12 is repaired based on the height (depth) data of the defective portion 12 obtained in advance, so that accurate and quick repair can be performed.

Note that in the above embodiment, the luminous intensity of the light emitted from the light emitting surface 13a of the light source 13 is changed;
If the wavelength of the light emitted from the light exit surface 13a of the light source 13 or the wavelength and the light source are simultaneously changed, and a color scanner is used as the video signal conversion means, the same effect as in the above embodiment can be obtained. be able to.

(Effects of the Invention) As explained above, according to the surface defect inspection device of the present invention, the surface defect inspection device of the present invention can obtain images of the surface to be inspected that are necessary for detecting the positions of surface defects on the surface to be inspected. The height (depth) of the surface defect is calculated by analyzing the size information and brightness information of the surface defect carried in the video signal. Therefore, since the height (depth) of the surface defect can be detected at the same time as the position of the surface defect, this height (depth) detection can be performed efficiently. Further, since the defective portion can be polished using this height (depth) data, the polishing process can be performed accurately.

[Brief explanation of the drawing]

FIG. 1(a) and FIG. 1(b) are respectively diagrams explaining the principle of the surface defect inspection apparatus according to the present invention, and FIGS. 2(a) and 2(b) are diagrams showing convex and An explanatory diagram of the camera image when there is a concave defect. Figures 3(a) and 3(b) show the incident direction of the light beam when there is a small convex defect and a large convex defect on the inspection surface, respectively. 4 is a schematic diagram illustrating how the specular reflection angle of a light beam is determined depending on the curved shape of a surface defect, and FIGS. A graph showing the signal level of the video signal when there are convex and concave defects on the surface. FIG. 7 is an explanatory diagram of an embodiment in which the surface defect inspection device according to the present invention is applied to a coating defect inspection device for an automobile body. FIG. 8 is an exploded perspective view of the light irradiation means. Fig. 9 is an explanatory diagram of a conventional surface defect inspection device, Fig. 10 is an explanatory diagram of an image obtained by the camera of the surface defect inspection device of Fig. 9, and Fig. 11 is an explanatory diagram of an image obtained when the surface to be inspected is a curved surface. An explanatory diagram of an image obtained by a camera. FIG. 12 is an explanatory diagram of a conventional surface defect inspection apparatus different from the apparatus shown in FIG. 9. 11... Surface to be inspected 12.121.122, 128-128... Defect portion 13... Light source 14... Video camera 15... Light received image 16... Position with high luminous intensity 17... Luminous intensity Small position 18... calculation unit 21
...Robot device 23...Light irradiation means 24.
...CCD camera 25...support metal fittings 2B...
Vehicle body 27... Paint surface 31... Host computer 32... Robot controller 33... Image processing processor 41... Box 42... Fluorescent lamp 43...
...Light filter 44...Diffusion screen 2nd
Figure (Phantom Figure 2 (b) Figure 3 (11') Figure 3 (B Figure 4 Figure 5 0) Position Figure 5 (b) Standing Figure 6 Figure 8 Figure 9 Figure 10 Figure 71-Figure 12

Claims (1)

[Scope of Claims] Light irradiation means for irradiating a surface to be inspected with light whose luminous intensity or wavelength gradually changes from large to small along a light exit surface, and from a light irradiation area of the surface to be inspected. a light-receiving surface for receiving reflected light, and a video signal converting means for converting a light-receiving image received by the light-receiving surface from the light irradiation area into a video signal; In a surface defect inspection device that detects surface defects on a surface, the video signal is inputted, and information on the size of the surface defect on the surface to be inspected and the luminous intensity or wavelength of the surface defect obtained from the video signal is input. A surface defect inspection device comprising a calculation means for calculating the height or depth of the surface defect based on change information.