JPH11271038A - Painting defect inspection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect painting defect with high precision, and with a simple device configuration, without depending on height or tilt of car's outer peripheral surface. SOLUTION: A painting defect inspection device for optically inspecting a painting condition comprises a stripe light source which projects a specified stripe pattern on an outer peripheral surface 1a of a car body 1, and a CCD camera 6 which, while moving relative to the outer peripheral surface 1a including the stripe light source, images the outer peripheral surface 1a vertically to the moving direction, and the image taken by the CCD camera 6 in time- series manner is processed to detect a painting defect of the outer peripheral surface 1a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating defect inspection apparatus for optically inspecting the state of a painted surface of a vehicle body, for example, in a production process of an automobile. The present invention relates to a coating defect inspection apparatus capable of detecting a defect with high accuracy even on a surface.

[0002]

2. Description of the Related Art In a coating defect inspection apparatus for optically inspecting a coating state of a vehicle body surface, a stripe pattern is formed on a vehicle body surface by projecting stripe-like light (stripe light). 2. Description of the Related Art There is an image capturing apparatus that captures an image of a vehicle body surface while relatively moving the vehicle body surface, and detects a defect from the captured image.

In such a coating defect inspection apparatus, for example, as shown in FIG. 12 (A), light from a light source 30 is projected through a sheet 32 provided with alternating transparent and black patterns, so that the inspection target surface s is exposed. A stripe pattern is formed. The inspection surface s on which the stripe pattern is formed
Is imaged from obliquely above by the camera 60, and the image is processed to detect a defect p.

When a paint defect inspection is performed on a vehicle body, the surface of the vehicle body is usually curved.
Changes, and the number of stripe patterns reflected in the image captured by the camera 60 changes.
When the surface to be inspected s is curved, the number of stripe patterns reflected in the image is larger than when the surface to be inspected s is flat. (FIG. 12 (B)). At this time, in the image processing, the defect on the boundary of the stripe pattern is not detected as an isolated point, and thus, the detection accuracy of the defect decreases when the number of boundary lines increases.

In order to suppress such a change in the number of stripe patterns and increase the accuracy of defect inspection, the pitch of a stripe pattern formed by a difference in the shape of the upper surface or the side surface of the vehicle body is changed, and an image to be picked up is obtained. There is a coating defect inspection apparatus in which a constant number of stripe patterns are always formed (Japanese Patent Application Laid-Open No. 9-184713).

[0006]

However, the coating defect inspection apparatus is generally used in a defect inspection process. Therefore, the paint defect inspection apparatus is applied to a plurality of types of vehicle bodies, and it is necessary to prepare sheets 32 of various patterns in order to match the stripe pattern to the vehicle body shape of all the types of vehicles. Need to be replaced.

Further, in the conventional paint defect inspection apparatus, since the camera 60 is directed obliquely to the inspection surface s, the measurement visual field v becomes relatively large. It is also necessary to increase the illumination area u for projecting light according to the measurement visual field. In addition, FIG.
In the case where the inspection surface s is curved as in (B), the measurement visual field v is larger than that in the case where the inspection surface s is a flat surface (FIG. 12A). The illumination area u must be designed in accordance with the maximum measurement visual field v.

Further, when inspecting a paint defect of a vehicle body, it is necessary to inspect the inspected surfaces s having different heights such as a hood and a roof as shown in FIG. In order to image the surfaces to be inspected s having different heights with the camera 60 fixed obliquely to the surface to be inspected, the illumination areas u1 and u2 are formed in order to form a stripe pattern in the measurement visual fields v1 and v2. This necessitates an increase in the size of the coating defect inspection apparatus.

Further, some recent paint defect inspection apparatuses have a function of displaying the position of a detected defect on a developed view of a vehicle body. In the development view of the vehicle body, a vehicle body viewed from the side or directly above is usually used.
Therefore, if the position of a defect detected by an image obtained by obliquely capturing the vehicle body is displayed on the developed view, the position of the detected defect is shifted from the position of the defect on the developed view.

For this reason, the conventional paint defect inspection apparatus requires a process of correcting the position of the detected defect according to the angle at which the defect is detected in addition to the process of detecting the defect from the captured image. Device configuration and processing time are required.

The present invention has been made in view of the above-mentioned problems in the conventional paint defect inspection apparatus, and can detect a paint surface defect with high accuracy regardless of the height or inclination of the surface to be inspected.
Moreover, an object of the present invention is to provide a coating defect inspection apparatus having a simple apparatus configuration.

[0012]

In order to achieve the above object, an invention according to claim 1 is directed to a coating defect inspection apparatus for optically inspecting a coating state of an object to be inspected. A light-dark pattern irradiating means for irradiating a predetermined light-dark pattern, and an outer peripheral surface including a light-dark pattern illuminated on the object to be inspected in the moving direction while relatively moving with respect to the object together with the light-dark pattern irradiating means Image processing means for processing a dynamic image of a light and dark pattern taken in time series by the imaging means to detect a coating defect on the outer peripheral surface of the inspection object. It is a feature.

With this configuration, when the outer peripheral surface of the inspection object is not inclined with respect to the moving direction, the imaging area imaged by the imaging means is minimized, and when the outer peripheral surface is inclined. In addition, it is possible to minimize the change in the imaging area.

Therefore, even when the surface to be inspected is tilted, it is possible to reduce the change in the light and dark pattern in the imaging area, and in particular, to reduce the change in the number of boundaries between the light and dark patterns, thereby keeping the accuracy of the defect inspection constant. it can.

Further, even when the surface to be inspected is tilted, the variation of the area of the irradiating means used for forming the light and dark pattern is reduced, and the light and dark pattern irradiating means for irradiating the light and dark pattern on the imaging area is reduced in size. Can be something.

In the invention according to a second aspect, the light and dark pattern includes a light source for uniformly irradiating the inspection object with light;
A light-dark pattern forming unit in which light patterns that transmit light emitted by the light source and dark patterns that block light are alternately arranged, and the imaging unit is provided in an area of the dark pattern. Things.

With this configuration, the imaging means can be provided perpendicular to the moving direction of the inspection object without damaging the light and dark patterns on the inspection object. Therefore, the coating defect inspection of the present invention can be realized with a relatively simple configuration.

Further, the invention according to claim 3 is characterized in that a scattered light suppressing member for suppressing scattering of light on the imaging means is provided on the front surface of the imaging means.

With this configuration, scattering of light occurring on the image pickup means is suppressed, and the quality of an image picked up by the image pickup means can be improved, and the accuracy of defect detection can be improved.

The invention according to claim 4 is characterized in that the defect detecting means has graphic processing means for displaying a result of the defect detecting means on a development view of the inspection object.

With this configuration, the position of a paint defect detected based on an image of the inspection object viewed from the side or directly above can be displayed on a developed view.

Therefore, the position of the detected paint defect can be displayed on the developed view without correcting it based on the angle at which the object to be inspected is imaged, and the process of displaying the position of the paint defect on the developed view is simplified. can do.

[0023]

According to the first aspect of the present invention, the accuracy of defect inspection can be made constant regardless of the inclination of the inspection surface. Further, the light and dark pattern irradiating means for irradiating the light and dark pattern onto the imaging area can be made small, and the painting defect inspection apparatus can be downsized.

Accordingly, it is possible to provide a paint defect inspection apparatus which can detect a defect on a paint surface with high accuracy and has a simple apparatus configuration.

According to the second aspect of the present invention, the coating defect inspection of the present invention can be realized with a relatively simple configuration.

According to the third aspect of the present invention, it is possible to improve the image quality of the image picked up by the image pickup means, and thus to improve the accuracy of defect detection.

Further, according to the present invention, it is possible to simplify the process of displaying the position of the coating defect on the developed view, and thus to simplify the configuration of the coating defect inspection apparatus. it can.

[0028]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram of an optical system of a coating defect inspection apparatus according to an embodiment of the present invention, and FIG.
FIG. 3B shows an example of installation of a light source (stripe light source) 40 for projecting a belt-like light on the vehicle body, and FIG.
Is shown.

The vehicle body 1 as an object to be measured is conveyed from a coating booth to an inspection stage by a conveyor in a direction perpendicular to the plane of the drawing, while being placed on the carriage 2.
A tunnel-shaped lighting device 40 is provided on the inspection stage so as to surround the transported vehicle body 1, and a stripe sheet 5 is further provided inside the lighting device 40.

The illuminating device 40 has a light source 4 arranged on the outer peripheral surface 1a of the vehicle body 1 so as to be able to emit light all over. The stripe sheet 5 is configured to transmit or block the light of the illumination device 40 emitted from the outside to form a stripe pattern on the outer peripheral surface 1a of the vehicle body 1. The illumination device 40 and the stripe sheet 5 are combined to form a stripe light source.

The inspection stage includes a CCD camera 6
Is provided with a stripe light source (FIG. 1B), and an image of the outer peripheral surface 1a on which the stripe pattern is formed is taken.

The detailed configurations of the lighting device 40, the stripe sheet 5, and the camera stand 7 will be described later.

The width C of the illuminating device 40 can be adjusted within a certain range so as to correspond to various types of vehicles having different vehicle sizes (the same applies to the stripe sheet 5 and the camera stand 7). . Also, here, the form in which the vehicle body 1 is moved has been described, but the present invention is not limited to this, and the lighting device 40, the stripe sheet 5,
Alternatively, the imaging site on the outer peripheral surface 1a of the vehicle body 1 may be changed with time by moving the CCD camera 6 (camera stand 7).

The CCD camera 6 of the present embodiment is similar to that of FIG.
(B) As shown in the drawing, the vehicle body 1 is fixed vertically all in the length direction, that is, in the transport direction. Therefore, C
The area of the surface to be inspected imaged by the CD camera 6 (field of view)
And the change of the stripe pattern in the measurement visual field caused by the undulation of the outer peripheral surface 1a is reduced. Therefore, a substantially constant width with respect to all the outer peripheral surfaces 1a of the vehicle body 1,
An image in which the pitch stripe pattern is captured can be captured, and the paint defect inspection conditions can be made the same for the entire vehicle body 1.

In addition, when the CCD camera 6 is provided perpendicular to the direction of transport of the vehicle body 1, the above-mentioned measurement field of view becomes smaller than when the CCD camera 6 is provided at an angle, and the change in the measurement field of view due to the inclination of the surface to be inspected. Becomes smaller. Therefore, the light source area can be relatively small, and the stripe light source can be downsized.

Hereinafter, the paint defect inspection apparatus of the present embodiment shown in FIG. 1 will be described in more detail.

FIG. 2 is a perspective view for explaining the stripe sheet 5. The striped sheet 5 includes a diffusing plate (not shown) that scatters and diffuses light to create a light source similar to a surface light source, and a sheet portion 5a that forms a striped pattern on the outer peripheral surface 1a of the vehicle body 1. It is configured to be attached to the part 5b. The sheet portion 5a is a sheet in which a stripe pattern including a transparent portion 51 and a black portion 52 is formed by applying, for example, a matte black masking tape to a transparent substrate at equal intervals.

FIG. 3 is a view of the illuminating device 40 viewed from the direction of the arrow D shown in FIG. The lighting device 40
It has two units 14, each unit 14
The frame 3 includes a background plate 3 a having a surface treated to diffuse and reflect light of white or light, and a plurality of straight tube-type fluorescent lamps as the light source 4. An inverter 90 for supplying high frequency power to the light source 4 is attached to the back surface of the background plate 3a (FIG. 4).

In this embodiment, a camera stand 7 in which the CCD cameras 6 are mounted in a line is disposed between the units 14. Since the above-mentioned stripe sheet 5 is provided inside the lighting device 40 (FIG. 1),
The light from each light source 4 is diffused by the stripe sheet 5 and becomes light of a planar stripe pattern (stripe light), which is emitted onto the outer peripheral surface (the inspection surface that is a painted surface) 1a of the vehicle body 1. Therefore, a stripe pattern similar to that of the sheet portion 5a of the stripe sheet 5 is formed on the outer peripheral surface 1a of the vehicle body 1.

The camera stand 7 includes a seat 5a.
The black portion 52 is disposed behind the black portion 52. Camera stand 7
The front black portion 52 is provided with a hole 6b for the CCD camera 6 to image the inspection surface s. The camera stand 7 also has an arched shape surrounding the vehicle body 1 (FIG. 1B), and the number and position of the CCD cameras 6 attached to the camera stand 7 are Appropriate settings are made so that the entire outer peripheral surface 1a can be imaged.

That is, each CCD camera 6 has a predetermined measurement field of view, and the measurement fields of view of adjacent CCD cameras 6 are continuous. Therefore, all the outer peripheral surfaces 1a of the vehicle body 1 are completely projected by all the installed CCD cameras 6.

FIGS. 4 and 5 show the stripe sheet 5 and the CC.
FIG. 4 is a diagram for explaining a positional relationship with the D camera 6.
5 is a sectional view taken along line AA of the configuration described in FIG.
FIG. 2 is a top view schematically showing the vehicle body 1 and the CCD camera 6 on the inspection stage.

As described above, the CCD camera 6 is disposed behind the black portion 52 of the sheet portion 5a, and receives the reflected light from the surface s to be inspected to image the surface s to be inspected. The optical path of the reflected light is covered with a light shielding plate 41, and the CCD camera 6
Is not affected by disturbance light or the like. Therefore, the CCD camera 6 receives only the reflected light passing through the hole 6b. The CCD camera 6 is mounted on the vehicle body 1 as shown in FIG.
Is fixed so as to receive reflected light having an optical axis (broken line) perpendicular to the traveling direction E, and an image of the inspection surface s is taken from a direction perpendicular to the traveling direction E.

When the portion corresponding to the hole 6b is formed in a mesh shape, scattering of reflected light occurring on the lens of the CCD camera 6 can be reduced, and an image with higher image quality can be taken.

Hereinafter, an image captured by the CCD camera 6 fixed as described above will be described with reference to FIG.

FIGS. 6A, 6B, and 6C show images taken by the CCD camera 6 fixed vertically to the traveling direction of the vehicle body 1. FIG. In FIG. 6A, the measurement visual field v1 is captured on the horizontal inspection surface s1, and
An image d1 is obtained. At this time, reflected light whose reflection angle is close to a right angle, that is, reflected light having a so-called reflection angle enters the CCD camera 6. Since the reflection angle and the incident angle are the same, C
Of the light projected from the stripe light source, light having an incident angle with respect to the inspection target surface s1 enters the CD camera 6.

That is, the inspection target surface s1 is
6 is taken from directly above, and FIG.
When the image of the inspection surface s2 curved as described above is taken, the change in the position and width of the stripe pattern of the image d2 becomes smaller with respect to the change in the angle of the inspection surface s2.

Accordingly, the number of stripe patterns (the number of boundaries between black and white patterns) reflected in an image is less likely to fluctuate, and the accuracy of defect inspection can be prevented from lowering, and the inspection accuracy can be stabilized.

Further, even when the angle of the surface to be inspected changes, the change in the angle of light reflected by the surface to be inspected is small, so that the change in the measurement visual fields v1 and v2 is small. Therefore, it is not necessary to increase the area of the stripe light source for forming the stripe pattern in the measurement visual field, and the length of the stripe light source along the longitudinal direction of the vehicle body (hereinafter referred to as the width) is shortened, and thus the coating defect inspection. The device can be miniaturized.

Further, when the surfaces to be inspected s3 and s4 having different heights are imaged by the same CCD camera 6 as shown in FIG. 6 (C), if there is a stripe light source region where a stripe pattern can be formed in the measurement visual field v4. The stripe pattern can be formed in any of the measurement visual field v3 on the inspection surface s3 and the measurement visual field v4 on the inspection surface s4. Thus, the coating defect inspection apparatus according to the present embodiment can reduce the width of the stripe light source, and thus can downsize the coating defect inspection apparatus.

FIGS. 7 and 8 show the inclination of the surface to be inspected,
Data obtained by measuring the relationship with the area of the stripe light source is shown for reference. FIG. 7 is a diagram illustrating an example in which the camera is arranged at an angle of 65 degrees with respect to a horizontal inspection surface (painted surface). FIG. 8 is a diagram illustrating an example of the present apparatus in which a camera is arranged at an angle of 90 degrees with respect to a horizontal inspection surface.

Next, a method for detecting a paint defect from an image picked up by the paint defect inspection apparatus having the above-described configuration will be described. FIG. 9 is a block diagram showing a configuration of a signal processing system of the present apparatus. Each of the n CCD cameras 6 is connected to a camera control unit 8, and each of these camera control units 8 is connected to an image processing device 9 as defect detection means.

Each CCD camera 6 outputs an image (stripe image) in which the stripe pattern of the measurement visual field is captured at a predetermined time interval (for example, 1/30 second) to an image processing apparatus via a camera control unit described later. I am going to send it. At this time, since the vehicle body is moving at a constant speed in the constant direction B, the stripe image captured by the CCD camera 6 at regular intervals is the vehicle body 1
Is an image in which the measurement visual field on the outer peripheral surface 1a is shifted at regular intervals.

The stripe image on the outer peripheral surface 1a of the vehicle taken by the CCD camera 6 at regular intervals is sent to the image processing device 9 via the camera control unit 8 as a video signal. Each image processing device 9 has a function of processing a stripe image captured by the CCD camera 6 to detect a coating defect and to detect the presence or absence of the vehicle body 1. The position and extent (size or rank) of the detected paint defect and the presence / absence (including position) of the detected vehicle body 1 are stored in a predetermined area of the internal memory as defect data and vehicle presence / absence data, respectively.

Each image processing device 9 is connected to a host computer 10 as graphic processing means. The host computer 10 has a function of counting the defect data and the vehicle presence / absence data sent from each image processing device 9, detecting a vehicle type, and displaying the position and the degree of the detected defect on a development view of the vehicle type. doing. Therefore, the built-in memory of the host computer 10 stores development view data for each vehicle type,
Registered pattern data for each vehicle type, position (angle) data of each CCD camera 6, and the like are stored in advance.

The processing result of the host computer 10 is output to the monitor 11 and the printer 12. An example of the output is as shown in FIG.

Hereinafter, the defect detection processing in each image processing apparatus 9 will be described. First, the principle of detection is as follows. When a light and dark pattern is applied to the painted surface, light is irregularly reflected at the defective portion and appears as an isolated point. Therefore, this is CCD
An image is taken by the camera 6, high-speed image processing is performed, and a defect is detected from an isolated point (a defect candidate point) and its movement. That is, when a plurality of stripe images having different imaging times are arranged so as to be arranged at regular intervals, the actual defect among the defect candidate points moves together with the vehicle body 1, but the erroneously detected point does not move. From this, the defect candidate point detected is tracked, and it is determined whether or not it is a defect. Specifically, the defect candidate point is actually located on the inspection surface 1a of the vehicle body 1 only when the movement amount of the extracted defect candidate point is equal to the actual movement amount of the vehicle body 1 obtained from the output of the pulse generator 14. Is determined to be a defect that exists in By tracking the movement of the defect candidate point in this manner, a coating defect can be detected with high accuracy.

As described above, the host computer 10 has a function of displaying the detected defect on the developed view of the inspected vehicle type. In addition, the model of the inspected car is
The image taken during the defect inspection can be determined by the host computer. Alternatively, the body shape data of the vehicle type may be stored in the host computer 10 in advance, and the inspector may select the corresponding vehicle type data from the data according to the vehicle type to be inspected.
Alternatively, the vehicle type may be determined by copying the body shape to a CCD camera and processing this data by the host computer 10.

Here, a development view for displaying a defect is shown for each CC.
In this embodiment, all the CCD cameras 6 are directed perpendicular to the moving direction of the vehicle body 1 as described above. Therefore, the CCD camera 6 facing the side of the vehicle body 1 captures an image of the vehicle body 1 as viewed from the side, and the CCD camera 6 facing the upper surface of the vehicle body 1 captures an image of the vehicle body 1 as viewed from directly below. Will be.

Therefore, the defect position detected by the present apparatus can be displayed as it is on the developed view on the data, and the actual position of the defect can be matched with the position on the developed view.
Therefore, in the present apparatus, the configuration and processing for correcting the defect position are not required, and the configuration for data processing can be simplified and the processing time can be reduced.

Next, the operation of the present apparatus configured as described above will be described with reference to the flowchart of FIG. When the limit switch 15 detects that the vehicle body 1 has entered the inspection stage (step S1), the host computer 10 outputs an image processing ON signal to each image processing device 9 to start measurement (step S2). . Here, each light source 4 is turned on at the same time as the vehicle body IN, and the power of each CCD camera 6 is turned on. Note that each light source 4 and each CCD camera 6 are not turned on / off in response to IN / OUT to the inspection stage. It may be turned on.

When the measurement starts, each image processing device 9 performs the above-described defect detection processing (step S3). That is, an image of the measurement visual field of the inspection target surface 1a is fetched from the corresponding CCD camera 6, and defect candidate points are extracted. And
After performing this extraction process a predetermined number of times at regular intervals, based on the positions and sizes of the defect candidate points extracted from each of the plurality of images, how the defect candidate points move in each image in time series Is calculated, and the amount of movement is
If it is determined that the defect candidate point is synchronized with the actual movement, the defect candidate point is determined to be an actual defect. The position and size (degree) of the defect thus detected are stored as defect data in another predetermined area of the built-in memory.

In this flowchart, the type of the vehicle body 1 to be inspected simultaneously with the detection of a defect by the image processing device 9 is automatically detected by the following processing. That is, each image processing device 9 detects from the image data of the corresponding CCD camera 6 whether or not an image of the vehicle body 1 is shown, and stores the result together with the imaging position data in a predetermined area of the built-in memory as vehicle presence / absence data. Memorize (Step S
4). The processes in steps S3 and S4 are repeated until the vehicle body 1 passes (step S5). Thereby, defects on the entire outer peripheral surface 1a of the vehicle body 1 are detected,
Also, a set of vehicle body patterns (vehicle type data) is measured.

When the vehicle body 1 passes, the host computer 10 sums up the processing results of each image processing device 9. In addition, here, in order to save energy,
Each light source 4 is turned off, and the power of each CCD camera 6 is turned off.

When the vehicle body 1 passes through the inspection stage, first, the vehicle type is detected from the vehicle type data. This is for selecting a development view for displaying a defect. (Step S
6). Next, unnecessary defects are deleted. That is, the detected defect located at a position other than the body in the developed view of the vehicle body is deleted and is not displayed (step S7). Then, the vehicle development view showing all the defects except the unnecessary defects obtained in step S7 is displayed on the screen of the monitor 11 or printed out from the printer 12 (step S8).

FIG. 11 shows an example of a developed view of a vehicle body with a defect display output from the host computer 10 via the monitor 11 and the printer 12. Thus, the operator can easily check at a glance which position of the vehicle body has a defect and how much.

According to the embodiment described above, when the outer peripheral surface of the vehicle body is not inclined with respect to the transport direction of the vehicle body, the measurement visual field captured by the CCD camera is minimized, and the outer peripheral surface is reduced. Even when tilted, the change in the measurement visual field can be minimized. Therefore, even when the vehicle body surface has an inclined shape, the change in the light and dark pattern in the imaging area is reduced, and the change in the number of boundaries between the light and dark patterns is particularly reduced, thereby keeping the accuracy of the defect inspection constant. be able to.

Further, according to the present embodiment, even when the surface to be inspected is inclined, the displacement of the position of the stripe light source used to form the stripe pattern in the measurement visual field becomes small, and the stripe light source can be reduced in size. It can be something.

Further, according to the present embodiment, the CCD camera can be provided perpendicularly to the moving direction of the vehicle body without damaging the stripe pattern on the outer peripheral surface of the vehicle body. Therefore, the main inspection can be realized with a relatively simple configuration.

Further, according to the present embodiment, the scattering of light occurring in the CCD camera is suppressed, the image quality of the captured image can be improved, and the accuracy of defect detection can be improved.

Further, according to the present embodiment, the position of the detected paint defect can be displayed on the developed view without correcting it based on the angle at which the vehicle body is imaged, and the process of displaying the position of the paint defect on the developed view is performed. Can be simplified.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an optical system of a coating defect inspection apparatus according to an embodiment of the present invention. FIG. 1A shows an example of installation of a stripe light source for projecting a belt-like light on a vehicle body. 1
(B) shows an example of installation of a CCD camera.

FIG. 2 is a perspective view illustrating a stripe sheet according to an embodiment of the present invention.

FIG. 3 shows the coating defect inspection apparatus shown in FIG.
It is the figure seen from the direction of arrow D shown in (A).

4 is a sectional view taken along line AA of the configuration shown in FIG.

FIG. 5 is a top view schematically showing a vehicle body and a CCD camera on an inspection stage according to one embodiment of the present invention.

FIG. 6 is a view showing an image picked up by a CCD camera according to an embodiment of the present invention, wherein FIGS.
(C) is an image captured by the CCD camera 6 which is fixed vertically to the traveling direction of the vehicle body.

FIG. 7 is a reference diagram showing data obtained by actually measuring the relationship between the inclination of the inspection surface and the area of the stripe light source.

FIG. 8 is another reference diagram showing data obtained by actually measuring a change in a region of a stripe light source which forms a stripe pattern in a measurement visual field caused by a tilt of a surface to be inspected.

FIG. 9 is a block diagram showing a configuration of a signal processing system of the paint defect inspection apparatus according to one embodiment of the present invention.

FIG. 10 is a flowchart illustrating an operation of the coating defect inspection apparatus according to the embodiment of the present invention.

FIG. 11 is a view showing an example of a developed view of a vehicle body with a defect display outputted by the paint defect inspection apparatus according to one embodiment of the present invention.

FIG. 12 is a view for explaining a problem of a conventional paint defect inspection apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Body 2 ... Car 4 ... Light source 5 ... Stripe sheet 6 ... CCD camera 7 ... Camera stand 8 ... Camera control unit 9 ... Image processing apparatus 10 ... Host computer 11 ... Monitor 12 ... Printer 13 ... Conveyor motor 14 ... Pulse generator 15 , 16, 24, 25 ... limit switch 40 ... lighting device 51 ... transparent part 52 ... black part

Claims (4)

[Claims] 1. A coating defect inspection apparatus for optically inspecting a coating state of an object to be inspected, comprising: a light and dark pattern irradiating means for irradiating a predetermined light and dark pattern on an outer peripheral surface of the object to be inspected; Imaging means for imaging an outer peripheral surface including a light and dark pattern illuminated on the inspection object perpendicularly to a moving direction while relatively moving with respect to the inspection object; A coating defect inspection device, comprising: a defect detection unit that processes a dynamic image of a light and dark pattern to detect a coating defect on an outer peripheral surface of the inspection object. 2. The light-dark pattern, wherein a light source for uniformly irradiating the object to be inspected with light, and a light pattern for transmitting light irradiated by the light source and a dark pattern for shielding light are alternately arranged. The coating defect inspection apparatus according to claim 1, further comprising a forming unit, wherein the imaging unit is provided in an area of the dark pattern. 3. The coating defect inspection apparatus according to claim 1, further comprising a scattered light suppressing member for suppressing light scattering on the image pickup means on a front surface of the image pickup means. 4. The paint defect inspection apparatus according to claim 1, wherein said defect detection means has a graphic processing means for displaying a result of said defect detection means on a development view of said inspection object.