JP2009047517A - Inspection apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inspection apparatus which easily detects inferior portions in inspection objects with high accuracy. <P>SOLUTION: A copper foil inspection apparatus 10 includes a light 12, a CCD camera 14, guide rollers 16 and a control section 18. The light 12 irradiating a copper foil 20 with light is disposed at a site irradiating a reading point O of the copper foil 20 positioned at a central portion between guide rollers 16 and irradiates the reading point O with light. The light, mirror-reflected at the reading point O by being irradiated from the light 12, progresses toward an arrow P. The CCD camera 14 of this embodiment is provided to receive the light on a face perpendicular to the direction of an arrow Q which differs several degrees from the direction of the arrow P and outputs image data transformed to 8-bit luminance signal, for example, per pixel to the control section 18 depending on the intensity of the received light. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an inspection apparatus, and more particularly to an inspection apparatus that inspects the deformation of a three-dimensional shape on the surface of an article.

  Conventionally, various inspections for optically detecting defects existing on the surface of the inspection object are performed by irradiating light on the surface of the inspection object such as a thin copper plate and analyzing the reflected light from the surface of the inspection object. A method has been proposed.

For example, Patent Document 1 discloses a defect caused by the adhesion of copper powder that does not have significant unevenness, based on the amount of specularly reflected light from the surface of the inspection target and the amount of scattered light. Techniques for detection are disclosed.
Republished patent WO2003 / 054530

  However, in order to accurately detect defects existing on the surface of the inspection target, it is necessary to capture the inspection target with a plurality of optical systems as in the technique described in Patent Document 1.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an inspection apparatus that easily and accurately detects a defective portion to be inspected.

  The present invention includes an irradiating unit that irradiates light to an inspection target, and an imaging unit that captures an image of light received from a direction different from the traveling direction of the light irradiated by the irradiating unit and regularly reflected by the inspection target; A dark region having a density exceeding a first threshold and a bright region having a density less than a second threshold smaller than the first threshold are extracted from the image captured by the imaging unit, and the dark region Detecting means for detecting a defective portion based on a positional relationship with the bright region.

  According to the present invention, the irradiating means irradiates light to the inspection object, and the imaging means is an image of light received from a direction different from the traveling direction of the light irradiated by the irradiating means and regularly reflected by the inspection object. Image. The detection means extracts a dark area whose density exceeds the first threshold and a bright area whose density is lower than the first threshold and less than the second threshold from the image captured by the imaging means, A defective portion is detected based on the positional relationship with the bright area.

  As described above, according to the present invention, it is possible to easily detect a defective portion to be inspected with high accuracy.

  The detecting means may detect a defective portion based on the positional relationship and the shapes of the dark area and the bright area.

  The detecting means may detect the dark area and the bright area as a defective part when the distance between the position of the dark area and the position of the bright area is equal to or less than a predetermined distance.

  Furthermore, when the position of the bright area with respect to the position of the dark area is on the side where the irradiation means is arranged, the detecting means deforms the three-dimensional shape that projects the dark area and the bright area to the surface side of the inspection object. When the position of the bright area with respect to the position of the dark area is on the side where the image pickup means is arranged, the dark area and the bright area are detected as a three-dimensional deformation in which the surface of the inspection object is recessed. can do.

  Moreover, the detection means detects a defective portion of the copper foil by irradiating the copper foil between the plurality of rollers with light as the copper foil wound around the plurality of rollers as the inspection object. It may be configured. By setting it as such a structure, both the deformation | transformation of the three-dimensional shape which protruded on the surface side of copper foil, and the deformation | transformation of the three-dimensional shape which dented on the back surface side of copper foil are detectable.

  Moreover, it is good to set it as the structure which a detection means detects the defective part of a copper foil because an irradiation means irradiates light to the copper foil on a roller. By comprising in this way, foreign materials, such as copper powder adhering between a roller and copper foil, can be detected. It is very difficult to detect foreign matter such as copper powder, but by detecting deformation of the copper foil due to adhesion of foreign matter such as copper powder, it is possible to inspect for the presence of foreign matter such as copper powder. It can be performed with high accuracy.

  According to the present invention, it is possible to easily detect a defective portion to be inspected with high accuracy.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
<First Embodiment>
As shown in FIG. 1, the copper foil inspection apparatus 10 according to the first embodiment includes a light 12, a CCD camera 14, a guide roller 16, and a control unit 18.

  The copper foil 20 to be inspected is discharged from a copper foil manufacturing apparatus (not shown) and guided to the copper foil inspection apparatus 10 through a plurality of rollers. Examples of the size of the copper foil 20 include those having a width of 1300 mm, 1350 mm, and a thickness of 12 μm, 18 μm, 35 μm, and 70 μm. The copper foil 20 is wound around the upper outer periphery of each guide roller 16 with the surface facing outward. Each guide roller 16 rotates in the direction of arrow X and transports the copper foil 20 in the direction of arrow Y.

  The light 12 that irradiates light to the copper foil 20 is installed at a position that irradiates the reading position O of the copper foil 20 that is located at the center between the guide rollers 16, and irradiates the reading position O with light. The light regularly reflected at the reading position O by being irradiated by the light 12 travels in the direction of the arrow P. The CCD camera 14 of the present embodiment is provided so as to receive light on a plane that is different from the direction of the arrow P and is perpendicular to the direction of the arrow Q where the light intensity is smaller than that of the regularly reflected light. The image data converted into, for example, an 8-bit luminance signal for each pixel according to the intensity of the received light is output to the control unit 18.

  As shown in FIG. 2, the control unit 18 includes a CPU (Central Processing Unit) 22, a ROM (Read Only Memory) 24, a RAM (Random Access Memory) 26, a reading device 28, an I / O port 30, and an HDD ( (Hard Disk Drive) 32, each of which is connected via a bus so as to be able to exchange signals.

  The CPU 22 governs the overall operation of the copper foil inspection apparatus 10 and executes a copper foil 20 inspection process to be described later according to a program.

  The ROM 24 is a nonvolatile storage device that stores a boot program that operates when the copper foil inspection apparatus 10 is started up.

  The RAM 26 is a volatile storage device that stores programs used in the execution of the CPU 22, parameters that change as appropriate during the execution, and various log data acquired during operation of the copper foil inspection apparatus 10.

  The reading device 28 is mounted with a storage medium such as a memory card made of semiconductor memory, a magneto-optical disk, an optical disk, and a magnetic disk, and reads the storage contents from the storage medium. The card for reading the storage contents of the memory card A reader, a magneto-optical disk device for reading the storage content of the magneto-optical disk, an optical disk device for reading the storage content of the optical disk, a magnetic disk device for reading the storage content of the magnetic disk, and the like can be used.

  The HDD 32 is a non-volatile storage device that stores a program for executing an inspection process of the copper foil 20 described later, data used for executing the program, and the like. Image data output from the CCD camera 14 is stored in the HDD 32 via the I / O port 30.

  In such a control unit 18, the CPU 22 reads the inspection program stored in the HDD 32 and executes the inspection program.

  In the present embodiment, the inspection process of the copper foil 20 is executed by the CPU 22 executing the inspection program.

  The program stored in the HDD 32, the data used for executing the program, and the like may be stored in a storage medium and read by the reading device 28. As described above, when the program, data used for executing the program, and the like are stored in the storage medium, when the storage medium is attached to the reading device 28, the CPU 22 stores the program stored in the storage medium, and Data used for executing the program is read and stored in the HDD 32.

  Next, with reference to FIGS. 3 and 4, the reflected light irradiated by the light 12 and reflected by the reading position O and the image picked up by the CCD camera 14 will be described.

  The copper foil 20 shown in FIG. 3A has a three-dimensional deformation (hereinafter referred to as convex dents) protruding on the surface side of the copper foil 20. As shown in FIG. 3A, in this embodiment, an inverted V-shaped convex dents will be described as an example, but the shape of the convex dents inspected by the copper foil inspection apparatus 10 is an inverse V. It is not limited to a letter shape.

  FIG. 3A shows the optical path of the light irradiated from the upstream side in the transport direction of the copper foil 20 by the light 12 and reflected at the reading position O.

  An arrow A1 indicates an optical path when the light beam irradiated by the light 12 is reflected in a region where no convex dents are generated. As indicated by the arrow A1, the reflected light reflected in the region where the convex dents does not occur travels in an oblique direction with respect to the optical axis of the CCD camera 14 indicated by the arrow Q, and therefore enters the CCD camera 14. The light intensity is small.

  An arrow A2 indicates an optical path when the light beam irradiated by the light 12 is reflected by the slope region on the upstream side of the convex dents. As indicated by the arrow A2, the reflected light reflected by the slope region on the upstream side of the convex dents travels along the optical axis of the CCD camera 14 indicated by the arrow Q. Therefore, the intensity of the light incident on the CCD camera 14 Is big.

  An arrow A3 indicates an optical path when the light beam irradiated by the light 12 is reflected by the slope region on the downstream side of the convex dents. As indicated by the arrow A3, the reflected light reflected by the slope region on the downstream side of the convex dents travels in a direction substantially perpendicular to the optical axis of the CCD camera 14 indicated by the arrow Q. The intensity of incident light is very small.

  FIG. 3B shows an outline of a change in the intensity of light that is irradiated by the light 12, reflected by a region including convex dents, and incident on the CCD camera 14. The horizontal axis indicates the reading position O, and the vertical axis indicates the intensity. The intensity when reflected by the upstream slope region is large, and the intensity when reflected by the downstream slope region is small.

  From this, when an area including convex dents is imaged by the CCD camera 14, an image as illustrated in FIG. 3C is obtained. The bright area L indicates the slope area portion on the upstream side of the convex dents, and the dark area D indicates the slope area on the downstream side of the convex dents.

  The copper foil 20 shown in FIG. 4A has a three-dimensional deformation (hereinafter referred to as concave dents) that is recessed on the back side of the copper foil 20. As shown in FIG. 4A, in this embodiment, a V-shaped concave dents will be described as an example, but the shape of the concave dents to be inspected by the copper foil inspection apparatus 10 is V-shaped. Not limited to.

  FIG. 4A shows an optical path of light irradiated from the upstream side in the transport direction of the copper foil 20 by the light 12 and reflected at the reading position O. FIG.

  An arrow A4 indicates an optical path when the light beam irradiated by the light 12 is reflected in an area where no concave dents are generated. As indicated by the arrow A4, the reflected light reflected in the region where the concave dents are not generated travels in an oblique direction with respect to the optical axis of the CCD camera 14 indicated by the arrow Q, and therefore enters the CCD camera 14. The light intensity is small.

  An arrow A5 indicates an optical path when the light beam irradiated by the light 12 is reflected by the slope region on the upstream side of the concave dents. As indicated by the arrow A5, the reflected light reflected by the slope region upstream of the concave dents travels in a direction substantially perpendicular to the optical axis of the CCD camera 14 indicated by the arrow Q. The intensity of incident light is large.

  An arrow A6 indicates an optical path when the light beam irradiated by the light 12 is reflected by the slope region on the downstream side of the concave dents. As indicated by the arrow A6, the reflected light reflected by the slope region on the downstream side of the concave dents proceeds along the optical axis of the CCD camera 14 indicated by the arrow Q, so that the intensity of the light incident on the CCD camera 14 is increased. Is very small.

  FIG. 4B shows an outline of a change in the intensity of light that is irradiated by the light 12, reflected by a region including concave dents, and incident on the CCD camera 14. The horizontal axis indicates the reading position O, and the vertical axis indicates the intensity. The intensity when reflected by the upstream slope region is small, and the intensity when reflected by the downstream slope region is large.

  From this, when an area including the concave dents is imaged by the CCD camera 14, an image as illustrated in FIG. 4C is obtained. A dark region D indicates a slope region on the upstream side of the concave dents, and a bright region L indicates a slope region portion on the downstream side of the concave dents.

  Therefore, in this embodiment, it is possible to detect the deformation of the three-dimensional shape by extracting a pair of a bright region and a dark region from the captured image. Furthermore, it is possible to determine whether the deformation of the three-dimensional shape is convex or concave from the positional relationship between the bright area and the dark area.

  Next, a routine for the inspection process of the copper foil 20 performed by the control unit 18 will be described with reference to the flowchart of FIG.

  In step 50, the image data output from the CCD camera 14 is received.

  In step 52, the average luminance value of the pixels arranged in the transport direction is obtained, the difference between the own luminance value and the average luminance value is obtained for each pixel, and the own luminance value is replaced with this difference value. Thereby, the striped pattern which arises in the conveyance direction in an image can be excluded.

  As described above, when the three-dimensional shape deformation has occurred in the copper foil 20, the image of the region corresponding to the three-dimensional shape deformation includes a pair of a region having a large luminance value and a region having a small luminance value. Occurs. Therefore, in step 54, the luminance value of each pixel replaced in step 52 is subjected to threshold processing. For example, when the luminance value is expressed by 256 gradations from −128 to 128, “3” is the first threshold value and “−3” is the second threshold value, and the luminance value of the pixel whose luminance value exceeds the first threshold value Is converted to “128”, the luminance value of the pixel whose luminance value is equal to or lower than the first threshold value and equal to or higher than the second threshold value is converted to “0”, and the luminance value of the pixel whose luminance value is less than the second threshold value is converted to Convert to “−128”. An example of the image data that has undergone the processing of step 54 is shown in FIG. Hereinafter, a pixel region having a luminance value of “128” is referred to as a bright region, and a pixel region having a luminance value of “−128” is referred to as a dark region.

  In step 56, the image data subjected to the threshold processing in step 54 is subjected to a noise filter to remove noise from the image data. Specifically, the brightness value of the bright area or the dark area where the same pixel value does not continue in the direction orthogonal to the transport direction or the transport direction in the bright area or the dark area is converted to “0”. First, the brightness value of a bright region or a dark region that is not continuous in the direction orthogonal to the transport direction is converted to “0” to obtain image data shown in FIG. Further, the brightness value of the bright area or dark area that is not continuous in the transport direction is converted to “0” to obtain the image data shown in FIG.

  In step 58, each of the dark area and the bright area is labeled and identified.

  In step 60, the dark area and the bright area are paired so that the distance between the position of the bright area and the position of the dark area is within a predetermined distance. This predetermined distance is set to a value by which it is possible to determine that the target bright region and dark region are three-dimensional deformation regions.

  In step 62, based on the size (for example, area) and shape of each dark region and light region paired in step 60, whether each dark region and light region pair is a three-dimensional shape deformation region or not. Determine whether. For example, when the size of the dark region and the bright region is too different, for example, when the areas of the dark region and the bright region differ by a predetermined value or more, it is determined that the deformation is not a three-dimensional shape. This predetermined value is set to a value by which it is possible to determine that the target bright region and dark region are three-dimensional deformation regions. In the determination based on the shape, for example, when at least one of the dark region and the bright region is too thin, it is determined that the deformation is not a three-dimensional shape.

  Further, in step 62, it is determined whether the deformation of the three-dimensional shape is convex or concave based on the positional relationship between the dark area and the bright area. That is, when the position of the bright area relative to the position of the dark area is on the side where the light 12 at the reading position O is installed, the dark area and the bright area are determined as convex dents. Further, when the position of the dark area with respect to the position of the bright area is on the side where the light 12 at the reading position O is installed, the dark area and the bright area are determined to be concave dents.

  Further, the control unit 18 can determine the size of the deformation of the three-dimensional shape based on the sizes of the dark region and the bright region. For example, it is possible to obtain the size of the deformation of the three-dimensional shape from the areas of the dark region and the bright region by obtaining a correspondence relationship between the areas of the dark region and the bright region and the size of the deformation of the three-dimensional shape in advance. it can.

  Further, the luminance value of the reflected light (before the threshold processing in step 54) differs depending on the slope angle of the three-dimensional shape deformation. From this, the correspondence between the luminance value of the reflected light and the slope angle of the three-dimensional shape deformation is obtained in advance, thereby obtaining the slope angle of the three-dimensional shape deformation from the luminance value of the reflected light. Can do. Further, the control unit 18 can determine the height of the three-dimensional shape deformation from the magnitude of the three-dimensional shape deformation and the slope angle of the three-dimensional shape deformation.

  Although the light and the CCD camera are installed at positions facing the upstream side and the downstream side in the copper foil transport direction, the light and the CCD camera need only be installed at positions facing each other with the reading position as the center. . For example, when the installation positions of the light and the CCD camera are switched, the positional relationship between the position where the dark area appears and the position where the bright area appears changes. In addition, when the light and the CCD camera are installed at opposing positions in the direction orthogonal to the copper foil conveyance direction, the position where the dark area appears and the position where the bright area appear are aligned in a direction perpendicular to the copper foil conveyance direction.

As described above, in the image captured by the CCD camera provided so as to receive light on a plane perpendicular to the direction different from the direction of the optical axis of the regularly reflected light, a region having a large luminance value and a region having a small luminance value And determining based on each extracted positional relationship, it is possible to accurately inspect whether or not a three-dimensional deformation has occurred in the copper foil.
<Second Embodiment>
Then, the copper foil test | inspection apparatus which concerns on the 2nd Embodiment of this invention is demonstrated.

  In the first embodiment, a case has been described in which whether or not a three-dimensional deformation has occurred in the copper foil based on the image of the copper foil being conveyed between the guide rollers has been described. In the embodiment, a case will be described in which it is inspected whether or not a three-dimensional deformation has occurred in the copper foil based on an image of the copper foil wound around the guide roller. In the following, differences from the first embodiment will be described.

  As shown in FIG. 7, the copper foil inspection apparatus 100 according to the second embodiment includes a light 102, a CCD camera 104, a guide roller 106, and a control unit 18.

  The copper foil 20 is wound around the upper outer periphery of the guide roller 106 with the surface facing outside. The guide roller 106 rotates in the direction of arrow X, and conveys the copper foil 20 in the direction of arrow Y.

  The light 102 that irradiates light to the copper foil 20 is installed at a position that irradiates the reading position R of the copper foil 20 that is located above the horizontal direction of the central portion of the guide roller 16, and irradiates the reading position R with light. To do. The light that is regularly reflected at the reading position R by being irradiated by the light 102 travels in the direction of the arrow S. The CCD camera 104 according to the present embodiment is provided so as to receive light on a plane perpendicular to the direction of the arrow T that is different from the direction of the arrow S by several degrees, and for each pixel according to the intensity of the received light. For example, the image data converted into an 8-bit luminance signal is output to the control unit 18.

  The copper foil inspection apparatus 100 configured as described above can detect foreign matter such as copper powder adhered between the guide roller 106 and the copper foil 20.

  Next, the reflected light that is irradiated by the light 102 and reflected by the reading position R and the image that is captured by the CCD camera 104 will be described with reference to FIG.

  The copper foil 20 shown in FIG. 8A has a three-dimensional deformation (hereinafter referred to as a copper powder portion) that protrudes to the surface of the copper foil 20 due to the adhesion of foreign matter such as copper powder 108. As shown in FIG. 8A, in this embodiment, an inverted V-shaped copper powder part is described as an example, but the shape of the copper powder part inspected by the copper foil inspection apparatus 100 is as follows. It is not limited to an inverted V shape.

  FIG. 8A shows an optical path of light irradiated from the upstream side in the transport direction of the copper foil 20 by the light 102 and reflected at the reading position R.

  An arrow A7 indicates an optical path when the light beam irradiated by the light 102 is reflected by a region that is not a copper powder portion. As indicated by the arrow A7, the reflected light reflected by the region that is not the copper powder portion proceeds in an oblique direction with respect to the optical axis of the CCD camera 104 indicated by the arrow T. The strength is small.

  An arrow A8 indicates an optical path when the light beam irradiated by the light 102 is reflected by the slope region on the upstream side of the copper powder portion. As indicated by the arrow A8, the reflected light reflected by the slope region on the upstream side of the copper powder portion travels along the optical axis of the CCD camera 104 indicated by the arrow T. The strength is great.

  An arrow A9 indicates an optical path when the light beam irradiated by the light 102 is reflected by the slope region on the downstream side of the copper powder portion. As indicated by the arrow A9, the reflected light reflected by the slope region on the downstream side of the copper powder portion travels in a direction substantially perpendicular to the optical axis of the CCD camera 104 indicated by the arrow T. The intensity of light incident on is very small.

  FIG. 8B shows an outline of a change in the intensity of light that is irradiated by the light 102, reflected by the region including the copper powder portion, and incident on the CCD camera 104. The horizontal axis indicates the reading position R, and the vertical axis indicates the intensity. The intensity when reflected by the upstream slope region is large, and the intensity when reflected by the downstream slope region is small.

  From this, when an area including the copper powder portion is imaged by the CCD camera 104, an image as illustrated in FIG. 8C is obtained. The bright region L indicates the slope region base portion on the upstream side of the copper powder portion, and the dark region D indicates the slope region on the downstream side of the copper powder portion.

  The control unit 18 performs the inspection process of the copper foil 20 shown in the flowchart of FIG.

  As described above, in the image captured by the CCD camera provided so as to receive light on a plane perpendicular to the direction different from the direction of the optical axis of the regularly reflected light, a region having a large luminance value and a region having a small luminance value Is extracted, and it is possible to accurately inspect whether or not a foreign matter such as copper powder is attached to the copper foil.

  Although it is very difficult to detect the copper powder itself, in this embodiment, it is possible to accurately inspect by detecting the deformation of the copper foil due to the adhesion of foreign matters such as copper powder.

It is a figure which shows the principal part of the copper foil test | inspection apparatus concerning the 1st Embodiment of this invention. It is a schematic block diagram of the control part of a copper foil test | inspection apparatus. It is a figure explaining the reflected light reflected by the convex dents which generate | occur | produced in copper foil. It is a figure explaining the reflected light reflected by the concave dent which generate | occur | produced in copper foil. It is a flowchart which shows the routine of the inspection process of copper foil. An example of an image obtained by performing image processing on a captured image is shown. It is a figure which shows the principal part of the copper foil test | inspection apparatus concerning the 2nd Embodiment of this invention. It is a figure explaining the reflected light reflected by the copper foil which deform | transformed with copper.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Copper foil inspection apparatus 12 Light 14 CCD camera 16 Guide roller 18 Control part 20 Copper foil 100 Copper foil inspection apparatus 102 Light 104 CCD camera 106 Guide roller

Claims (7)

Irradiating means for irradiating the inspection object with light;
An imaging unit that captures an image by light received from a direction different from a traveling direction of the light irradiated by the irradiation unit and regularly reflected by the inspection target;
Extracting from the image captured by the imaging means a dark region having a density exceeding a first threshold and a bright region having a density less than a second threshold smaller than the first threshold, and the dark region and the Detecting means for detecting a defective portion based on a positional relationship with a bright region;
Inspection device with   The inspection apparatus according to claim 1, wherein the detection unit detects a defective portion based on the positional relationship and shapes of the dark region and the bright region.   The detection unit detects the dark area and the bright area as the defective portion when a distance between the position of the dark area and the position of the bright area is equal to or smaller than a predetermined distance. Or the inspection apparatus of Claim 2.   The detection means has a three-dimensional structure in which the dark area and the bright area protrude from the surface of the inspection object when the position of the bright area with respect to the position of the dark area is on the side where the irradiation means is disposed. The inspection apparatus according to any one of claims 1 to 3, wherein the inspection apparatus detects the deformation as a shape.   When the position of the bright region with respect to the position of the dark region is on the side where the imaging unit is disposed, the detection unit has a three-dimensional shape in which the surface of the inspection object is recessed between the dark region and the bright region. The inspection device according to claim 1, wherein the inspection device is detected as a deformation of the inspection. The inspection object is a copper foil wound around a plurality of rollers,
The inspection apparatus according to claim 1, wherein the irradiation unit irradiates light to a copper foil between the plurality of rollers. The inspection object is a copper foil wound around a roller,
The said irradiation means irradiates light to the copper foil on the said roller, The inspection apparatus in any one of Claims 1-5 characterized by the above-mentioned.