JP5776467B2 - Defect inspection equipment - Google Patents

Description

  The present invention relates to an inspection apparatus for inspecting a defect of a container having a seal portion that closes an opening.

  It is conceivable to detect only a specific area on an image obtained by imaging the inspection object and use inspection means and inspection parameters suitable for the detected area, such as an improvement in inspection accuracy and a reduction in false detection. FIG. 1A is a diagram schematically showing an image obtained by imaging the upper surface of a container having a seal portion that closes the opening, and FIG. 1B is a view showing a cross section of the container having the seal portion that closes the opening. . As shown in FIG. 1A, in the seal portion 12 of the packaging container existing on the inspection object 11 of the image 10 taken, the seal edge portion 13 sets the inspection threshold strictly for detecting the leakage of the contents. There is a need to. In addition, the area | region enclosed with the broken line shown with the code | symbol 13a is a peripheral area | region of the seal edge part 13, and does not appear in the imaged image.

  In this case, it is easy to set the seal edge portion 13 and the packaging container wall surface sticking portion 15 as a special region if the position of the seal is known. However, a circular object such as the object to be inspected 11 that is continuously conveyed on the production line is subject to a minute rotation due to the influence of the transfer process or the previous process during the conveyance process, and the position of the special region. Therefore, it is necessary to specify a special area from the inspection area for each inspection object.

  In particular, in the case of a packaging container for beverages, the sanitary condition of the drinking mouth is important, and it is necessary to inspect whether the wall surface of the packaging container is dirty. However, the wall surface 14 of the packaging container has a packaging container wall surface sticking portion (a portion where the seal is attached) 15, and it is often difficult to discriminate between a seal and dirt from the luminance information of the image. Further, based on the color information of the image, if the seal color and the stain color are the same, it becomes impossible to determine. Therefore, it is necessary to specify the seal part affixed to the packaging container wall surface as a special area and set it as a non-inspection area.

  Conventionally, Patent Document 1 and Patent Document 2 are known as countermeasures for the problem of specifying a special area. The means of Patent Document 1 is a means for preparing a reference image in advance and specifying a special area by comparing the target image with the reference image. The means of Patent Document 2 is a means for preparing a reference image for each rotation angle in order to cope with rotation of a special area to be specified, and for specifying and determining a special area corresponding to the rotation from comparison with each image. Yes. In any case, both means require a reference image preparation step. In addition, image processing such as comparison processing with a reference image is a process that requires a relatively long time. In order to apply it to a production line that requires continuous inspection in a short time, parallel processing using multi-core or hardware It is necessary to consider processing using hardware. In addition, the characters and patterns printed on the seal portion are different depending on the cutting position at the time of producing the seal even in the same product type, and there is a case where the method of comparison processing using the reference image cannot be used.

JP 2006-005813 A JP 2004-037415 A

The present invention has been made in view of the above problems, and does not require a preparatory process for specifying a special area for an object to be inspected having a seal portion that closes an opening that is continuously conveyed through a production line. An object of the present invention is to provide an inspection apparatus with excellent inspection performance that can greatly reduce the inspection time.

The invention according to claim 1 of the present invention is an inspection apparatus for inspecting a defect of a container having a seal portion that closes an opening,
Means for transporting the container;
A first optical means having a first illuminating means for illuminating the container, a first imaging means for imaging the container, and a first container detecting means for detecting the container;
A second illuminating means for illuminating the container; a second imaging means for imaging the container; and a second container detecting means for detecting the container. A second optical means comprising:
Obtaining the edge coordinates of the seal part from the image captured by the first imaging means, first special area specifying means for specifying the first special area from the edge coordinates of the seal part,
First inspection means for detecting a liquid leakage defect of the seal portion based on a first special region of the image captured by the first imaging means;
The edge coordinates, the angle difference between the mounting angle of the first imaging means and the mounting angle of the second imaging means, the center coordinates of the inspection area in the captured image obtained from the first imaging means, and the second imaging means A second special area specifying means for specifying a second special area of the image obtained by the second imaging means from the center coordinates of the inspection area in the picked-up image obtained from:
A defect inspection apparatus comprising: a second inspection unit that detects a foreign object defect in a container based on a second special region of an image captured by the second imaging unit.

  The invention according to claim 2 of the present invention is characterized in that the first special area specifying means specifies the first special area from the luminance step of the one-dimensional luminance distribution on the circumference from which the luminance is to be read. A defect inspection apparatus according to claim 1.

  The invention according to claim 3 of the present invention is the defect inspection apparatus according to claim 1 or 2, wherein the second inspection means performs inspection by masking the second special area.

  The invention according to claim 4 of the present invention is the defect inspection apparatus according to claim 1, wherein the first imaging means is an infrared camera.

  According to the inspection apparatus of the present invention, it is possible to suppress the occurrence of erroneous inspection without requiring complicated processing for defect detection on the inspection object continuously conveyed by the conveyance device. .

(A) is a schematic diagram of the image which imaged the upper surface of the container which has a seal part which block | closes opening. (B) is a figure which shows the cross section of the container which has a seal part which plugs up opening. The figure which shows schematic structure of the defect inspection apparatus which concerns on this invention. The figure which shows an example of the image imaged by the imaging part 221 which concerns on this invention. The figure which showed acquisition of the circumference (collection of an upper point) which should read luminance on the image data used when specifying the seal | sticker part 12 of a 1st special area. (A) is a figure which shows the luminance distribution of the circumference which should read the acquired luminance. (B) is a figure which shows the brightness | luminance level | step difference on the brightness distribution obtained from the circumference which should read a brightness | luminance. The figure which shows judging the position and orientation of the seal part in a to-be-inspected object from the specified seal edge part 113. FIG. The flow of image processing in the second optical means using the image processing of the image obtained by the first optical means according to the present invention and the specified seal edge information obtained by the first optical means is shown. Figure. The figure for demonstrating the method of calculating | requiring the coordinate point of the seal edge part of a 2nd optical means from the coordinate point of the seal edge part acquired from the 1st optical means which concerns on this invention.

  Embodiments of the present invention will be specifically described below with reference to the drawings.

FIG. 2 is a diagram showing a schematic configuration of the defect inspection apparatus according to the present invention. The defect inspection apparatus includes a transport unit 25 that transports the container 20, a reflection light source unit 231 that is a first illumination unit that illuminates the container, and an imaging unit 221 that is a first image capturing unit that images the container. And a first optical means having a container detecting unit 241 that is a first container detecting means for detecting the container, and a second optical device that is provided downstream of the first optical means in the container transport direction and illuminates the container. A second light source unit 232 that is a illuminating unit, an imaging unit 222 that is a second imaging unit that images the container, and a container detection unit 242 that is a second container detection unit that detects the container. The image processing unit 26-is a first special region specifying unit that obtains the edge coordinates of the seal portion from the image picked up by the optical means and the first image pickup means, and specifies the first special region from the edge coordinates of the seal portion. 1 and the first imaging means An inspection unit 27-1, which is a first inspection unit that detects a liquid leakage defect of the seal unit based on a first special region of the captured image, the edge coordinates, the mounting angle of the first imaging unit, and the first From the angle difference between the mounting angles of the second imaging means, the center coordinates of the inspection area in the captured image obtained from the first imaging means, and the center coordinates of the inspection area in the captured image obtained from the second imaging means, Based on the image processing unit 26-2, which is a second special region specifying unit that specifies the second special region of the image obtained by the second imaging unit, and the second special region of the image captured by the imaging unit 221. And an inspection unit 27-2 which is a second inspection unit for detecting a foreign matter defect in the container.
The image processing unit 26-1 and the image processing unit 26-2 are integrated as an image processing unit 26. The inspection unit 27-1 and the inspection unit 27-2 are integrated as the inspection unit 27.

  As described above, there are two sets of imaging units, reflected light source units, and container detection units. The first set captures an image for specifying the first special region. The first set includes the imaging unit 221, the reflection light source unit 231, the container detection unit 241, and the specified first special area. The second special region obtained by reflecting the coordinate information from the region is masked to capture an image for inspecting the packaging container wall surface. From the imaging unit 222, the reflected light source unit 232, and the container detection unit 242 The second optical means.

  The role of the first optical means is to capture an image for specifying the first special area, and for this purpose, the imaging section needs to be hardly affected by the color or pattern of the seal section, such as InGaAs. An infrared camera using a light receiving element that captures the difference in absorption wavelength is suitable. Since an image is formed with a difference in absorption wavelength, it is possible to specify a special region stably without being affected by characters or patterns printed on the seal portion. Moreover, since the difference in absorption wavelength is utilized, it is suitable for detecting leakage of contents attached to the top surface of the container.

The role of the second optical means is to capture an image for inspecting the packaging container wall surface part by reflecting the specified special region information. In other words, the imaging unit 222 is for detecting foreign matter (dirt) adhering to the container wall surface portion of the seal unit. For this purpose, a camera capable of imaging in the visible light region is used. However, if an image is captured in the visible light region, the seal edge portion cannot be specified when there is a pattern on the seal portion. In addition, the imaging unit 222 needs to use a lens with a large angle of view such as a fish-eye lens or a wide-angle lens in order to image the detection container wall surface. Regardless of which lens is used, it is difficult to uniformly illuminate the wall surface and the top surface because it must be close to the object to be imaged in order to image the wall surface. Need to be separated.

  As the reflected light source units 231 and 232, for example, light sources such as LEDs, halogen lamps, and xenon lamps are used. Furthermore, when infrared illumination suitable for the absorption wavelength of water is used, the infrared camera can detect liquid more effectively. Is possible. The imaging unit 221 is preferably an infrared camera that is not easily affected by characters and patterns on the object to be inspected. If the image capturing unit 222 can detect dirt from the luminance information and color information of the image, the CCD, An area camera or a line camera using a light receiving element such as a CMOS is used.

  The mounting angle between the imaging unit 221 and the imaging unit 222 has an angle difference due to restrictions on the space of the mounting location and adjustment errors, and the center coordinates of the inspection area in the captured image are also different.

  The captured image is converted into digital data of 256 gradations or 4096 gradations by an image data processing unit (not shown). Image data obtained by identifying a special area from image data captured by the first optical means in the image processing section based on the digital data converted by the image data processing section and capturing the special area information by the second optical means. The position of the seal portion overlapping the container wall surface portion is specified, the seal portion is masked, and the inspection portion 27 inspects the container wall surface portion and the image data captured by the first optical means is used for the container ceiling. Perform surface inspection.

  In addition, since the object to be inspected is moved by the transport device, container detection units 241 and 242 are provided that generate an external trigger signal for detecting the movement of the object to be inspected and releasing the shutter with good timing. An optical sensor can be used for the container detection unit.

  FIG. 3 is a diagram schematically illustrating an example of an image captured by the imaging unit 221. In the image 110, a seal portion 112 having a different position for each inspection object is provided on the inspection object 111. The seal attaching portion 115 overlapping the edge portion 113 of the seal portion 112 and the packaging container wall surface portion 114 becomes a special region such as a portion where the inspection threshold is to be tightened or a portion where the inspection threshold is to be loosened in order to improve inspection accuracy. In addition, the area | region enclosed with the broken line shown with the code | symbol 113a is a peripheral area | region of the seal edge part 113, and does not appear in the imaged image.

  FIG. 4 is a diagram illustrating acquisition of a circumference (a collection of upper points) 30 from which luminance is to be read on image data used when specifying the seal portion 12 of the first special region. In order to detect the position of the seal portion 112, a one-dimensional luminance distribution on the circumference on the inner side by a specified distance from the outer circumference of the inspection object 111 is created. 31 and 32 corresponding to the seal edge portion are detected from the circumference 30 from which the luminance is to be read, and the position of the seal portion is specified.

  FIG. 5A shows the luminance distribution of the circumference from which the acquired luminance is to be read. Since the seal portion is made of a material different from other regions of the object to be inspected, a luminance step 40 corresponding to the position of the seal edge portions 31 and 32 on the luminance distribution obtained from the circumference 30 from which the luminance is to be read. 41 occurs.

  Further, when a differentiation process is performed on this luminance distribution, it is possible to obtain a distribution showing peaks 42 and 43 at the maximum and minimum luminance steps as shown in FIG. 5B. Therefore, if the maximum and minimum luminance step peaks 42 and 43 shown in FIG. 5B are detected, it is possible to detect different seal positions for each object to be inspected. It becomes possible to specify the packaging container wall surface sticking part 115).

FIG. 6 is a diagram showing that the position and orientation of the seal portion in the inspection object are determined from the identified seal edge portion 113. An edge having a length L1 from the coordinate 50 _max to the inside on the inspection object, an edge having a length L2 from the coordinate 50 _min to the inside on the inspection object, and a known length connecting the points of these two edges The seal edge portion 113 is specified by obtaining the edge of L3. In the inspection section 27-1, which is the first inspection means, the specified seal edge section 113 performs inspection with a strictly set inspection threshold value in order to detect leakage of contents.

  Next, since the image picked up by the first optical means is used and the specified seal edge information is used for image processing of the image data picked up by the second optical means, the inspection portion for the second optical means The seal edge information is transmitted to. Since the inspection of the first optical means and the inspection of the second optical means can be performed with the same software, the seal edge information can be easily shared.

  FIG. 7 is a view showing a flow of processing in the first optical means and processing in the second optical means using the seal edge portion information specified by the first optical means.

  First, the seal edge is specified as the first special region using the image acquired by the first optical means. And the specified seal edge part information is transmitted to the image picked up by the second optical means, the wall surface sticking part is specified as the second special area based on this information, and the specified wall face sticking part Is set as a special area that is not inspected to suppress false detection. In this way, it is possible to perform a high-performance inspection without determining that the character or pattern printed on the wall surface sticking portion is a defect.

The coordinates 50 _max and coordinates 50 _min , which are seal edge information acquired from the image processing unit of the image obtained by the first optical means shown in FIG. 6, are obtained by the second optical means using the following equations. It is reflected in the obtained image data. The acquired coordinate points of the seal edge portion are _defined as (X50 _max1 , Y50 _max1 ) and (X50 _min1 , Y50 _min1 ). Then, the coordinate points (X50 _max 2, Y50 _max 2) and (X50 _min 2, Y50 _min2 ) of the seal edge obtained by the second optical means are calculated.

FIG. 8 shows the seal edge of the image obtained by the second optical means from the coordinate points ((X _max1 , Y _max1 ) and (X _min1 , Y _min1 )) of the seal edge portion of the image obtained from the first optical means. It is a figure for _{demonstrating the} method of calculating _| requiring the coordinate point (( _Xmax2 , _Ymax2 ) and ( _Xmin2 , _Ymin2 )) of a part.
First, the coordinates are rotated by an angle D from (X _max1, Y _max1 ) to (X _max2, Y _max2 ) with the rotation center as the origin (S1). The angle D in this case is due to a difference in installation angle between the imaging unit 221 and the imaging unit 222, and the angle D is known from an image captured in advance. Next, it is adjusted to the magnification of the second optical means (not shown).
in this case,
Magnification PW in the width direction = (resolution in the X direction of the image captured by the second optical means) / (resolution in the X direction of the image captured by the first optical means)
Magnification PH in the height direction = (resolution in the Y direction of the captured image of the second optical means) / (resolution in the Y direction of the captured image of the first optical means).
Further, the image of the second optical means is translated around the center (not shown) (in this case, the first and second optical means need not be moved if the rotation center is the image center).
From the above results, the following equation is obtained.
X _max2 = PW (CX _max1 · cosD−CY _max1 · sinD) + CX ₂
Y _max2 = PH (CX _max1 · sinD + CY _max1 · cosD) + CY ₂
here,
CX _max1 = X _max1 -CX ₁
CY _max1 = Y _max1 -CY ₁
CX ₁ and CY ₁ are coordinates when the center of the inspection area of the image in the first optical means is the rotation center. CX ₂ and CY ₂ are coordinates when the center of the inspection area of the image in the second optical means is the rotation center. The reason for considering the rotation is that the imaging unit 221 of the first optical unit and the imaging unit 222 of the second optical unit may be installed in different directions due to installation restrictions or the like. For example, when the imaging unit 222 is installed 180 degrees inverted with respect to the imaging unit 221, the rotation angle D is 180 degrees.

That is, the coordinates of the seal edge 50 _max2 of the second optical means from the seal edge 50 _max1 imaged and obtained by the first optical means shown in FIG.
_{X50 max2 = PW {(X50 max1} -CX 1) · cosD
− (Y50 _max1− CY ₁ ) · sinD} + CX _{2
Y50 max2 = PH {(X50 max1} -CX 1) · sinD
+ (Y50 _max1 -CY ₁ ) · cosD} + CY ₂

Similarly, when the coordinate point (X50 _min2 , Y50 _min2 ) is calculated, the following equation is obtained.
X50 _min2 = PW {(X50 _min1 -CX ₁ ) · cosD
− (Y50 _min1 −CY ₁ ) · sinD} + CX ₂
Y50 _min2 = PH {(X50 _min1 -CX ₁ ) · sinD
_{+ (Y50 min1 -CY 1) ·} cosD} + CX 2
However, the image captured by the image capturing unit 221 and the image capturing unit 222 may be slightly different depending on the lens or the like, so it is desirable to finely adjust the position in the image capturing unit to be used.

  Using the seal edge portion information reflected on the second optical means by the second inspection means, affixing the packaging container wall surface seal at a known distance and range from the seal edge portion to the outside direction of the object to be inspected. The part 15 is specified, and this area is masked as an area not to be inspected.

  The inspection unit 27-2 as the second inspection means inspects the top surface of the packaging container from the special area specified by the above means, and the second optical means inspects the packaging container wall surface.

  As described above, according to the defect inspection apparatus of the present invention, it is possible to suppress the occurrence of erroneous detection without requiring complicated processing for defect detection on the inspection object continuously conveyed by the conveyance device. Is possible.

DESCRIPTION OF SYMBOLS 10 ... Captured image 11 ... Test object 12 ... Seal part 13 ... Seal edge part 13a ... Peripheral area | region 14 ... Sealing container wall surface part 15 ... Packaging Container wall surface sticking unit 20 ... Container 21 ... Arrow 25 indicating the direction in which the container is conveyed 25 ... Conveying unit 26 ... Image processing unit 27 ... Inspection unit 30 ... Circumferential luminance distribution 31 and 32 ... seal detection positions 40 and 41 ... luminance step 42 and 43 ... luminance step peak 50 ... seal edge part detection position 110 ... captured image 111 ... inspection object 112 ... Seal part 113 ... Seal edge part 113a ... Peripheral region 114 of the seal edge part ... Packaging container wall surface part 115 ... Packaging container wall surface sticking part 221 ... Imaging part 222・ Image pickup unit 231. Light source unit 232 ... reflective light source portion 241 ... container detecting unit 242 ... container detector

Claims (4)

An inspection apparatus for inspecting a defect of a container having a seal portion that closes an opening,
Means for transporting the container;
A first optical means having a first illuminating means for illuminating the container, a first imaging means for imaging the container, and a first container detecting means for detecting the container;
A second illuminating means for illuminating the container; a second imaging means for imaging the container; and a second container detecting means for detecting the container. Having second optical means;
Obtaining the edge coordinates of the seal part from the image captured by the first imaging means, first special area specifying means for specifying the first special area from the edge coordinates of the seal part,
First inspection means for detecting a liquid leakage defect of the seal portion based on a first special region of the image captured by the first imaging means;
The edge coordinates, the angle difference between the mounting angle of the first imaging means and the mounting angle of the second imaging means, the center coordinates of the inspection area in the captured image obtained from the first imaging means, and the second imaging means A second special area specifying means for specifying a second special area of the image obtained by the second imaging means from the center coordinates of the inspection area in the picked-up image obtained from:
A defect inspection apparatus comprising: a second inspection unit that detects a foreign object defect in a container based on a second special region of an image captured by the second imaging unit.   2. The defect inspection apparatus according to claim 1, wherein the first special area specifying unit specifies the first special area from a luminance step of a one-dimensional luminance distribution on a circumference from which luminance is to be read.   The defect inspection apparatus according to claim 1, wherein the second inspection unit inspects the second special area by masking.   The defect inspection apparatus according to claim 1, wherein the first imaging unit is an infrared camera.

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