JP2004085204A - Buckling inspection device and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To optically inspect the deformation of a cylindrical object from the reflected light from the object even if the inspected object has a pattern. <P>SOLUTION: This buckling inspection device comprises a plurality of light sources of different colors for generating linear illuminating light, and a plurality of image pickup devices for picking up the image of reflected light, reflected by the object, of the light emitted from the plurality of light sources. A pair of the plurality of light sources and the plurality of image pickup devices are arranged on one side with respect to the conveying direction of the cylindrical object, in a position where a plurality of specular reflected light from the same cylindrical object by the illuminating light from each light source are simultaneously photographed by the plurality of image pickup devices. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to optical detection of deformation of an inspection object.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, various methods for irradiating a cylindrical inspection object with light to detect its deformation (for example, buckling) have been known. For example, the object is irradiated with a laser beam or the like, and whether the object is deformed is determined based on whether the reflected light from the object is normal or abnormal. For example, as shown in FIG. 1, light having a very strong directivity (slit-shaped laser light) is applied to an object, and reflected light from the object is imaged by a camera. Various methods have been adopted as image processing methods. In a captured image, for example, if a normal image should be observed if it is normal, and if a broken line, a curve, or the like is observed, it can be determined that the object is deformed.
[0003]
[Problems to be solved by the invention]
In this optical inspection system, what is imaged by the camera is the diffuse reflection light reflected from the inspection object. The diffuse reflection light is light containing a large amount of color components of the object, and therefore, a good result can be obtained when the target object has no pattern or pattern. However, if the target object has a color pattern, the inspection is strongly affected by the color pattern, making inspection difficult. For example, when a linear image is to be observed, an intermittent line may be observed despite being normal.
[0004]
SUMMARY OF THE INVENTION It is an object of the present invention to optically inspect the deformation of a cylindrical object from reflected light of the object even when the object to be inspected has a pattern or pattern.
[0005]
[Means for Solving the Problems]
A buckling inspection device according to the present invention includes a plurality of light sources of different colors for irradiating a cylindrical object with linear illumination light, and a plurality of color imaging devices for imaging reflected light from the cylindrical object. One set of the plurality of light sources and the plurality of color imaging devices is disposed on one side with respect to the transport direction of the cylindrical object, and each light source and each color imaging device are provided by one light source. A plurality of specularly reflected lights from the same cylindrical object are installed at positions where the plurality of color image pickup devices respectively photograph the same.
[0006]
In the buckling inspection device, for example, the set of the plurality of light sources and the plurality of color imaging devices can be respectively disposed on both sides in the transport direction of the cylindrical object. A plurality of light sources and a plurality of imaging devices can be arranged as one set along the transport direction of the cylindrical object.
[0007]
The buckling inspection device preferably further includes an image processing device that processes the image data received from the imaging device and enables detection of deformation of the cylindrical object.
[0008]
In the buckling inspection method according to the present invention, a plurality of light sources of different colors for irradiating the cylindrical object with linear illumination light, and a plurality of cameras for imaging reflected light from the cylindrical object at the first predetermined position are provided. One set of the color imaging device is placed on one side with respect to the transport direction of the cylindrical object, and each light source and each color imaging device are connected to a plurality of specularly reflected lights from the same cylindrical object by one light source. Each is installed at a position where the image is captured by the plurality of color imaging devices. Next, when the conveyed cylindrical object reaches the first predetermined position, the plurality of imaging devices photograph the specularly reflected light from the cylindrical object.
[0009]
In the buckling inspection method, further, for a cylindrical object at a second predetermined position on the downstream side of the first predetermined position, a plurality of different colors for irradiating the cylindrical object with linear illumination light. Another set of a light source and a plurality of color imaging devices for imaging the reflected light from the cylindrical object, the cylindrical shape irradiated by each light source on one side with respect to the transport direction of the cylindrical object. A plurality of specularly reflected lights from the object are installed at positions where the plurality of color image pickup devices respectively photograph the plurality of specularly reflected lights. Then, the cylindrical object further conveyed from the first predetermined position is rotated, and when the rotated cylindrical object reaches the second predetermined position, the cylindrical object is moved from the cylindrical object. The specular reflected light is photographed by the plurality of imaging devices.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
In the buckling inspection apparatus according to the present invention, light is irradiated to a cylindrical inspection object, and the mirror-reflected light is imaged by a camera to inspect the deformation of the object. FIG. 2 schematically shows a buckling inspection apparatus according to one embodiment of the present invention. In this system, two different color light sources 10r, 10g, and 10b, each of red (R), green (G), and blue (B), apply linear diffused illumination light of a different color to the cylindrical inspection object 12. Irradiate. As the light source 10, a linear fluorescent lamp, an LED, an optical fiber, or the like is used. The inspection object 12 is conveyed on the conveyor belt 14. The optical system shown in FIG. 2 is installed on one side of the conveyor belt 14 in the transport direction. When the object 12 is irradiated with diffuse illumination light by the color light source 10, the illumination light is reflected from the object 12 in multiple directions. The reflected light includes specular reflected light and diffuse reflected light. Only specularly reflected light traveling along an optical path determined by the geometrical positional relationship between the light source 10, the camera 18, and the inspection object 12 is reflected by the reflection mirror 16 and enters the camera 18. Image data from the two cameras 18 is read into the image processing device 20. The image processing device 20 is a computer, and performs inspection based on an input image by a known image analysis technique. Here, a detailed description of the image processing device 20 is omitted. The image picked up by the camera 18 is an image formed by specular reflection light from the object 12, and the specular reflection light is the light of the light source 10 itself, so the color of the object 12 itself (color pattern formed on the surface of the object, etc.) ). Therefore, even if the object 12 is a printed color pattern, deformation can be detected in principle and effectively.
[0011]
In order to inspect a wide range of the surface shape of the object 24, the object 12 is irradiated with a large number (six in this example) of color light sources 10, and the specular reflected light from the inspection object 12 is transmitted to the upstream side in the transport direction. The light is reflected by a reflection mirror 16 installed on the downstream side, and is imaged by two color cameras 18. The plurality of light sources 10 and the two color cameras 18 are installed at positions where specular reflected light traveling along an optical path determined by the geometrical positional relationship between the light sources 10, the camera 18 and the inspection object 12 simultaneously enters each camera 18. You. The color light sources 10 are arranged so that light sources of the same illumination light do not adjoin each other. Two specularly reflected lights by the diffuse illumination light from each light source 10 are reflected from different positions on the surface of the object 12 and are incident on two cameras 18. In this example, the angle between the two cameras 18 and the object 12 is 120 °, and the positions of the six light sources 10 are determined by geometric calculation. However, the angle formed by the camera and the number of light sources are not limited thereto. Further, the number of cameras (therefore, the number of reflection mirrors) is not limited to two.
[0012]
FIG. 3 schematically shows an image of one color camera 18. In this image, linear specularly reflected light (bright lines) from light sources 10 of different colors are arranged in the order of red, green, and blue corresponding to the color of the illumination light. If this bright line is not linear, it can be determined that deformation has occurred.
[0013]
As shown in FIG. 4, actually, one set of optical systems shown in FIG. 2 is installed on both sides of the conveyor belt with the inspection object 12 interposed therebetween. Thereby, a wide range of the outer shape of the inspection object 12 can be inspected. The object 12 is conveyed between the guides 15 on both sides of the conveyor belt 14, but the guide 15 is not installed at a position where the illumination light and the specular reflected light are blocked. When the object 24 moves on the conveyor, the object 24 reaches a first imaging position where specularly reflected light is incident on the color camera due to the geometric positional relationship between the light source 10, the object 12, and the color camera 18. Here, the four cameras 18 capture the specular reflected light at the first capturing position. The image processing device 20 reads image data from the four cameras 18 respectively.
[0014]
When the object is further conveyed on the conveyor belt 14, the object is rotated by the rotation mechanism 22. In this example, the rotation mechanism 22 is a contact plate with which the inspection object 12 contacts. By touching this, it is rotated about 90 °. Further, as the object 24 moves on the conveyor, the object 24 reaches the second imaging position where the specularly reflected light is incident on the color camera due to the geometric positional relationship between the light source 10, the object 12, and the color camera 18. A set of optical systems shown in FIG. 2 is also installed on both sides of the second imaging position, and similarly, specular reflected light is imaged. In this way, by rotating the inspection target and imaging a plurality of times, the entire circumference of the outer shape of the inspection target 12 can be photographed, and the outer shape can be inspected.
[0015]
【The invention's effect】
Since the specular reflected light is imaged, the inspection can be performed without being affected by the color components of the cylindrical object itself. In addition, since a plurality of color light sources having different colors are used, the influence of diffuse reflected light captured together with specular reflected light can be reduced.
Furthermore, by connecting the image processing device to the imaging device, it is possible to process the image data and detect the deformation of the object.
[Brief description of the drawings]
FIG. 1 is a diagram of a buckling inspection device using diffuse reflection light. FIG. 2 is a diagram of a buckling inspection device using specular reflection light. FIG. 3 is a diagram schematically showing an image of a camera. Diagram of another buckling inspection device using reflected light [Explanation of symbols]
10r, 10g, 10b Linear red, green, and blue color light sources, 12 inspection objects, 14 conveyor belts, 16 reflection mirrors, 18 color cameras, 20 image processing devices.

Claims (5)

A plurality of light sources of different colors for illuminating a cylindrical object with linear illumination light,
Consists of a plurality of color imaging devices that image reflected light from a cylindrical object,
One set of the plurality of light sources and the plurality of color imaging devices is disposed on one side with respect to the transport direction of the cylindrical object, and each light source and each color imaging device are provided by one light source. A buckling inspection device installed at a position where a plurality of specularly reflected lights from the same cylindrical object are respectively imaged by the plurality of color imaging devices. The buckling inspection device according to claim 1, wherein the one set of a plurality of light sources and the plurality of color imaging devices are arranged on both sides along a conveying direction of the cylindrical object. 3. The buckling device according to claim 1, further comprising an image processing device configured to process image data received from the color imaging device and detect a deformation of the cylindrical object. Inspection equipment. A set of a plurality of light sources of different colors for irradiating a cylindrical object with line-shaped illumination light and a plurality of color imaging devices for imaging reflected light from the cylindrical object at a first predetermined position, On one side with respect to the conveying direction of the object, and each light source and each color imaging device, a plurality of specularly reflected lights from the same cylindrical object by one light source are respectively provided by the plurality of color imaging devices. A seat that is installed at a position where an image is captured and captures mirror-reflected light from the cylindrical object by the plurality of imaging devices when the conveyed cylindrical object reaches the first predetermined position. Crook inspection method. Further, for a cylindrical object at a second predetermined position downstream of the first predetermined position, a plurality of light sources of different colors for irradiating the cylindrical object with linear illumination light, Another pair of a plurality of color imaging devices for imaging the reflected light is provided on one side with respect to the transport direction of the cylindrical object, and a plurality of specularly reflected lights from the cylindrical object illuminated by the respective light sources on one side. Is installed at a position where each of the plurality of color imaging devices is photographed,
Rotating the cylindrical object further conveyed from the first predetermined position, and when the rotated cylindrical object reaches the second predetermined position, the specular reflection from the cylindrical object The buckling inspection method according to claim 4, wherein the light is photographed by the plurality of imaging devices.

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