HK40008602B - Container inspection device and container inspection method - Google Patents

Description

Container inspection device and container inspection method

Technical Field

The present invention relates to a container inspection device and a container inspection method.

Background Art

As a method for detecting thin bubbles that are extremely rarely generated on the inner surface of a container, particularly a glass bottle, there is an inspection method previously proposed by the applicant of the present application (Patent Document 1).

Thin bubbles form on the inner surface of a glass bottle, formed by a very shallow depression relative to the inner surface and a thin glass film covering the depression. This inspection method uses a stripe filter with multiple horizontal slits arranged vertically and at regular intervals on an opaque plate to detect thin bubbles. Light is transmitted only through the slits, and the light that has passed through the thin bubble is used to capture an image in which the width of the light and dark areas is compressed vertically.

While this method can detect thin bubbles, it is difficult to distinguish between shadows caused by thin bubbles and light and dark caused by uneven wall thickness of the glass bottle, or light and dark caused by the seams of the glass bottle (steps formed at the joints of the mold). Therefore, even qualified glass bottles are often judged as defective, and it is desirable to reduce the rejection rate of qualified products.

In addition, the applicant of the present application has proposed an inspection device for detecting defects such as wrinkles of glass bottles using a light control film (Patent Document 2). This inspection device is difficult to detect very shallow, concave, thin bubbles on the inner surface.

Prior art literature

Patent Literature

Patent Document 1: Japanese Patent Publication No. 7-11490

Patent Document 2: Japanese Patent Application Laid-Open No. 2013-134185

Summary of the Invention

Problems to be solved by the invention

An object of the present invention is to provide an inspection device and an inspection method capable of inspecting containers for defects such as thin bubbles with unclear outlines.

Solutions for solving problems

The present invention has been made to solve at least a part of the above-mentioned problems, and can be implemented as the following aspects or application examples.

[Application Example 1]

The container inspection device of this application example is characterized by comprising:

a light-emitting portion having a light-emitting surface for irradiating light onto the container;

a photographing unit, which is arranged to face the light-emitting unit across the container;

a determination unit that determines the presence or absence of a defect based on the image of the container captured by the imaging unit; and

a light limiting portion disposed on the container side of the light emitting portion;

The light limiting portion includes a light transmitting portion and a light reducing portion extending in a horizontal direction along the light emitting surface.

The light transmitting portion and the light reducing portion are alternately arranged in the vertical direction.

The light-transmitting portion transmits the light emitted from the light-emitting portion toward the container.

The light reducing unit includes a plurality of louvers extending in the horizontal direction in the vertical direction, and limits an incident angle of the light emitted from the light emitting unit with respect to the vertical direction.

According to this application example, the presence or absence of defects such as thin bubbles with unclear outlines can be inspected by utilizing the change in brightness in the vertical direction of the container surface caused by the light transmitting portion and the light reducing portion.

[Application Example 2]

In the container inspection device of this application example, it may be possible to:

The dimming portion is disposed on the light emitting surface of the light emitting portion, and a height of the dimming portion from the light emitting surface is 0 mm to 100 mm.

According to this application example, it is possible to suppress the shadow of the joint and emphasize the shadow of a defect such as a thin bubble with unclear outline in a captured image.

[Application Example 3]

In the container inspection device of this application example, it may be possible to:

The width of the light-transmitting portion in the vertical direction is 3 mm to 6 mm.

According to this application example, the shadow of the outline of a defect such as a thin bubble with unclear outline can be recognized.

[Application Example 4]

In the container inspection device of this application example, it may be possible to:

The light reduction portion is formed by overlapping a plurality of light control films.

According to this application example, by emphasizing the intensity of light in the vertical direction on the container surface, the outline of a defect such as a thin bubble with unclear outline can be emphasized.

[Application Example 5]

In the container inspection device of this application example, it may be possible to:

The light limiting portion is a first light limiting portion disposed at a position corresponding to a region of the container below the predetermined height position in the vertical direction.

The device further includes a second light limiting portion at a position corresponding to an area above the predetermined height position on the container side of the light emitting portion, the second light limiting portion reducing the amount of light emitted from the light emitting portion transmitted.

The second light limiting sections are arranged at predetermined intervals in the horizontal direction.

According to this application example, by using different optical systems to inspect the lower area of the container where defects such as thin bubbles with unclear contours are easily produced and the upper area where such defects are not easily produced, the influence of uneven wall thickness and seams can be eliminated, the contours of defects such as thin bubbles can be easily displayed, and the load of image processing can be suppressed.

[Application Example 6]

In the container inspection device of this application example, it may be possible to:

The above-mentioned judgment unit identifies at least one detection object from the captured image, and sets a prescribed range including the identified detection object in the vertical inspection area extending in the above-mentioned vertical direction and the horizontal inspection area extending in the above-mentioned horizontal direction. When more than two detection objects are included in the above-mentioned vertical inspection area and the above-mentioned horizontal inspection area, it is judged as a defect.

According to this application example, even a detection object whose contour is divided into a plurality of parts and recognized can be determined as a defect.

[Application Example 7]

In the container inspection device of this application example, it may be possible to:

The determination unit recognizes at least one detection object from the captured image, and if the recognized detection object is in the shape of a ring or an arc, determines that the detection object is a defect based on the area associated with the detection object.

According to this application example, a detection object having a ring-shaped outline or a detection object having an arc-shaped outline can also be determined as a defect.

[Application Example 8]

In the container inspection device of this application example, it may be possible to:

The determination unit recognizes at least one detection object from the captured image and determines that the detection object is a defect when a portion having a brightness equal to or greater than a predetermined threshold value is included in a predetermined range including the recognized detection object.

According to this application example, a test object including a portion with a bright outline and a portion with a dark outline can also be determined as a defect.

[Application Example 9]

The container inspection method of this application example is characterized in that:

The light emitted from the light emitting portion and the light that has passed through the dimming portion that limits the incident angle of the light from the light emitting portion relative to the vertical direction using a horizontally extending louver are alternately irradiated toward the container in the vertical direction.

The image of the container is captured by a capturing unit that is arranged to face the light emitting unit across the container.

Bubbles on the inner surface of the container are judged as defects.

According to this application example, the presence or absence of defects such as thin bubbles with unclear outlines can be inspected by utilizing the change in brightness in the vertical direction of the container surface caused by the light transmitting portion and the light reducing portion.

Effects of the Invention

The present invention can provide an inspection device and an inspection method for inspecting containers for defects such as thin bubbles with unclear outlines.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a side view of a container inspection device.

FIG2 is a front view of a light emitting unit, a first light limiting unit, and a second light limiting unit.

FIG. 3 is a diagram showing a container and its image side by side.

FIG4 is an enlarged cross-sectional view of a thin bubble.

FIG. 5 is an enlarged view of A in FIG. 1 .

FIG. 6 is a diagram illustrating the shape of the outline of a thin bubble in a captured image.

FIG. 7 is a diagram illustrating an inspection mode in a determination unit.

FIG8 is a flow chart of a method for inspecting a container.

DETAILED DESCRIPTION

Hereinafter, preferred embodiments of the present invention will be described in detail using the accompanying drawings. In addition, the embodiments described below are not intended to unduly limit the content of the present invention as described in the claims. In addition, all the structures described below are not necessarily essential components of the present invention.

The container inspection device of this embodiment is characterized in that it includes: a light-emitting unit having a light-emitting surface for irradiating light onto the container; a photographing unit arranged to face the light-emitting unit with the container interposed therebetween; a determination unit for determining the presence or absence of defects based on the image of the container photographed by the photographing unit; and a light limiting unit arranged on the container side of the light-emitting unit, the light limiting unit including a light-transmitting unit and a light-reducing unit extending in the horizontal direction along the light-emitting surface, the light-transmitting unit and the light-reducing unit being alternately arranged in the vertical direction, the light-transmitting unit transmitting light emitted from the light-emitting unit toward the container side, the light-reducing unit having a plurality of louvers extending in the horizontal direction in the vertical direction, for limiting the angle of incidence of light emitted from the light-emitting unit with respect to the vertical direction.

1. Overview of container inspection equipment

An overview of an inspection device 1 for a container 10 will be described using Figures 1 to 3. Figure 1 is a side view of the inspection device 1 for a container 10 (hereinafter referred to as "inspection device 1"). Figure 2 is a front view of the light emitting unit 20, the first light limiting unit 24, and the second light limiting unit 26. Figure 3 shows a container and its image side by side.

As shown in Figures 1 to 3, the inspection device 1 includes: a light-emitting unit 20 having a light-emitting surface 22 for irradiating light onto a container 10; an imaging unit 40 arranged to face the light-emitting unit 20 with the container 10 interposed therebetween; a determination unit 52 that determines the presence or absence of defects based on an image 80 (Figure 3) of the container 10 captured by the imaging unit 40; and a first light limiting unit 24 arranged on the container 10 side of the light-emitting unit 20.

The first light limiting unit 24 is positioned at a position corresponding to an area 13a of the container 10 below a predetermined height position H1 ( FIG. 3 ) in the vertical direction Y. The inspection device 1 may further include a second light limiting unit 26. The second light limiting unit 26 is positioned on the container 10 side of the light emitting unit 20, corresponding to an area 13b above the predetermined height position H1. By using different optical systems (the first light limiting unit 24 and the second light limiting unit 26) to inspect the lower area 13a of the container, where defects such as thin bubbles with unclear outlines are likely to occur, and the upper area 13b, where such defects are less likely to occur, the effects of uneven wall thickness and seams can be eliminated, making the outlines of defects such as thin bubbles more clearly visible, and reducing the image processing load. Therefore, as long as the load on the control unit 50 is not a problem, the first light limiting unit 24 may be positioned to correspond to the entire container 10. Defects will be described later.

1 , the container 10 is inspected in an upright position, that is, with its axis 12 aligned with the vertical direction Y. The vertical direction Y is the direction of gravity, and the horizontal direction X is a direction perpendicular to the vertical direction Y.

Inspection device 1 includes a rotation support unit 30 that supports container 10 while rotating it about axis 12, and side rollers 32 that rotate container 10 while contacting the side surfaces of container 10. FIG1 illustrates side rollers 32 positioned between container 10 and imaging unit 40. This is for ease of explanation and is located so as not to obstruct imaging unit 40 from imaging container 10.

Container 10 is a glass bottle and is transparent or translucent. Translucent refers to a degree of transparency that allows the detection of defects on the inner surface 15 of container 10 using light from light-emitting unit 20 transmitted through container 10. The cross-section of container 10 is, for example, circular. Alternatively, the cross-section of container 10 may be polygonal.

The predetermined height position H1 varies depending on the type of container 10, the state of molding, and the like. The predetermined height position H1 can serve as a so-called settle line. The settle line is a portion where the wall thickness changes at the boundary between the portion in contact with the mold and the portion not in contact with the mold, formed by the settle blow used for mouth molding. The settle line can be formed in the horizontal direction X of the container 10. The predetermined height position H1 can be set to the boundary between the region 13a below the container 10, where thin bubbles 18 are likely to form, and the region 13b above the container 10, where thin bubbles 18 are less likely to form.

The inspection device 1 is a light transmission type inspection device 1, which uses light transmitted through the container 10 to capture the main body 13 of the container 10 with the imaging unit 40, and detects the portion darker than the surrounding area in the captured image 80 (Figure 3) as a detection object in the container 10.

2. Defects

Defects to be detected by the inspection apparatus 1 will be described using Figures 3 and 4. Figure 4 is an enlarged cross-sectional view of the thin bubble 18. In Figure 4, the thickness of the arrows indicates the amount of light transmitted.

As shown in Figure 3, when the imaging unit 40 captures the main body 13 of the container 10, an image 80 is obtained. In image 80, for example, seams 16, thin bubbles 18, and uneven wall thickness 19 can be identified as test objects. Seams 16 are not defects, but rather steps in the joints of the mold used to form the container 10, appearing in image 80 as dark lines along the vertical direction Y. Thin bubbles 18 are defects that rarely occur below the predetermined height position H1 of the container 10. Uneven wall thickness 19 is not a defect, but rather a dark area caused by variations in the wall thickness of the main body 13 of the container 10. Other defects include burn marks.

Sometimes, thin bubbles 18 are generated on the inner surface 15 of the container 10 below the predetermined height position H1. Thin bubbles 18 are generated due to differences in the ease of stretching caused by temperature differences in the parison during the molding process of the container 10. Thin bubbles 18 are hollow bubbles with extremely shallow recesses (for example, a depth of less than 100 μm from the inner surface 15) and have a roughly circular outline. Therefore, in the image 80, although the outline of the thin bubble 18 appears slightly darker than the surrounding area, it is difficult to distinguish because it is usually the same brightness as the seam 16 and the uneven wall thickness 19. The inspection device 1 must be able to distinguish the thin bubble 18 from the seam 16, the uneven wall thickness 19, and other parts that are not defects.

However, if only a filter is used to detect thin bubbles 18, as in the conventional method of Patent Document 1, it is possible that the thin bubbles 18 will be detected and the seams 16 will be judged as defects, thus rejecting otherwise acceptable containers 10 as defective. The same applies to the method of Patent Document 2. This is because the difference in brightness between the thin bubbles 18 and the surrounding area is small, and the difference in brightness between the thin bubbles 18 and non-defective seams 16 is not significant.

3. Luminous part

The light emitting unit 20 will be described using FIG. 1 and FIG. 2 .

As shown in Figures 1 and 2 , the light emitting unit 20 is a light source that illuminates the container 10. The light emitting unit 20 is a surface light source having a light emitting surface 22 on the container 10 side and capable of illuminating the container 10 from the side opposite the imaging unit 40. The light emitting unit 20 is set to a size that can illuminate the entirety of the largest container 10 scheduled for inspection by the inspection apparatus 1.

As shown in FIG2 , the light emitting surface 22 of the light emitting unit 20 on the container 10 side is rectangular and emits light almost entirely. The light emitting unit 20 is arranged to face the container 10 and the imaging unit 40 so that light transmitted through the container 10 reaches the imaging unit 40 .

As the light source of the light-emitting unit 20, known light sources such as LEDs and organic EL can be used. The light-emitting unit 20 is a diffuser. If an LED is used, a diffuser plate can be used in front of the light source (light-emitting surface 22) to illuminate the container 10 with uniform light. The diffuser plate can be a known diffuser plate that diffuses light from a light source such as an LED and emits it to the outside. By diffusing the light using a diffuser plate, even when multiple light sources are used, unevenness can be reduced in areas where no light sources are present.

A light limiting portion is provided on the light emitting surface 22 .

4. Light limiting unit

The first light limiting section 24 and the second light limiting section 26 serving as light limiting sections are described using Figures 1, 2, and 5. In Figure 2, the container 10 is shown in dashed lines to illustrate the positional relationship between the first light limiting section 24 and the second light limiting section 26. Figure 5 is an enlarged view of A in Figure 1.

4-1. First Light Limiting Unit

As shown in Figures 1, 2, and 5, the first light limiting portion 24 is positioned corresponding to the region 13a below the predetermined vertical height H1 (Figure 3) of the container 10. This is to reliably detect thin bubbles 18 that tend to form below the container 10. The first light limiting portion 24 includes light-transmitting portions 244 and light-reducing portions 242 extending along the light-emitting surface 22 in the horizontal direction X. The first light limiting portion 244 and light-reducing portions 242 are alternately arranged in the vertical direction Y. This is to allow the first light limiting portion 24 to transmit light that is diffusely emitted from the light-emitting surface 22 toward the container 10 in the horizontal direction X, while limiting the light that is diffusely emitted in the vertical direction Y.

Light-transmitting portion 244 transmits light emitted from light-emitting portion 20. Light-transmitting portion 244 is a slit. Light-transmitting portion 244 does not block light from light-emitting surface 22. To eliminate shadows cast by joint 16, sufficient horizontal light passing through light-transmitting portion 244 illuminates container 10.

As shown in Figure 5, the dimming section 242 includes a plurality of louvers 243 extending in the horizontal direction X in the vertical direction Y, thereby limiting the angle of incidence of light emitted from the light-emitting section 20 in the vertical direction Y. The louvers 243 are formed to extend in the horizontal direction X and the thickness direction of the dimming section 242. The dimming section 242 preferentially transmits light along the louvers 243 from the diffused light from the light-emitting surface 22. Therefore, the diffused light from the light-emitting surface 22 is narrowed by the dimming section 242, and the transmission of light diffused in the vertical direction Y is particularly limited. The louvers 243 extend, for example, in a direction perpendicular to the light-emitting surface 22. Therefore, the dimming section 242 preferentially transmits light emitted from the light-emitting surface 22 in the horizontal direction X.

As shown in image 80 of FIG3 , the brightness variation in the vertical direction Y of the inner surface 15 of the container 10 caused by the light-transmitting portion 244 and the light-reducing portion 242 appears as a striped pattern with a gentle brightness variation. Furthermore, this brightness variation in the vertical direction Y can be used to identify defects such as thin bubbles 18 with unclear outlines in image 80, allowing the inspection device 1 to determine the presence of defects.

Furthermore, due to the light-transmitting portions 244 and light-reducing portions 242 alternately arranged in the vertical direction Y, light diffused in the horizontal direction X sufficiently reaches the container 10. Therefore, dark seams 16 caused by horizontal steps are less likely to appear in the image 80 (changes in brightness are reduced). Uneven wall thickness 19, manifested as variations in wall thickness in the horizontal direction, is also less likely to appear as dark areas in the image 80 (changes in brightness are reduced).

The dimming portion 242 is disposed on the light-emitting surface 22 of the light-emitting unit 20. The height of the dimming portion 242 from the light-emitting surface 22 is 0 mm to 100 mm. The dimming portion 242 has a predetermined thickness, which suppresses the shadow of the joint 16 in the captured image 80 and emphasizes the shadows of defects such as the unclear thin bubbles 18. The height of the dimming portion 242 from the light-emitting surface 22 can also be 0 mm to 100 mm.

The light-reducing portion 242 is formed by overlapping multiple light-controlling films. By emphasizing the intensity of light in the vertical direction Y on the inner surface 15 of the container 10, the outlines of unclear defects such as thin bubbles 18 can be emphasized. Figure 5 shows an example of two 0.5 mm thick light-controlling films overlapped and bonded together in the thickness direction. Commercially available light-controlling films can be used, such as "LIGHT CON FILM 60DEG 12×11" manufactured by 3M.

The width of the light transmitting portion 244 in the vertical direction Y can be 3 mm to 6 mm. The inventors of the present invention have examined various samples of thin bubbles 18 and found that this width is appropriate for identifying the shadow of the outline of defects such as thin bubbles 18 with unclear outlines.

By performing differential processing in the horizontal direction X and the vertical direction Y on the portion of the image 80 corresponding to the lower area 13a in the image processing unit 53 described later, the striped pattern, the seam 16 and the dark portion of the uneven wall thickness 19 caused by the dimming portion 242 and the light transmitting portion 244 can be removed, while retaining the shadow of the outline of the thin bubble 18.

As shown in Figure 2 , the first light limiting section 24 is constructed by alternating light-reducing sections 242 and light-transmitting sections 244 by providing a plurality (three in Figure 2 ) of slits at predetermined intervals in a sheet formed by laminating two light control films. The first light limiting section 24 has elongated holes 246 extending in the vertical direction Y at both ends of its width (horizontal direction X) and is secured to the light-emitting section 20 by bolts 28. The first light limiting section 24 can move in the vertical direction Y along the elongated holes 246, allowing its position to be adjusted to match the height of the container 10.

4-2. Second Light Limiting Unit

As shown in Figure 2, two second light restricting sections 26 are arranged at a predetermined interval in positions corresponding to region 13b above predetermined height position H1. This is because upper region 13b is not a region where very shallow bubbles 18 are generated, as is lower region 13a. The second light restricting sections 26 may be connected or integrally formed, as long as they have a predetermined interval sufficient to allow light from the light emitting section 20 to pass therethrough.

The two second light limiting sections 26 reduce the amount of light emitted from the light emitting section 20 that is transmitted. The two second light limiting sections 26 are arranged with a predetermined spacing in the horizontal direction X. The bubbles generated on the inner surface 15 in the upper region 13b are not extremely shallow bubbles 18 and can therefore be detected even with the structure of the second light limiting sections 26. The predetermined spacing in the horizontal direction X is narrower than the width of the upper region 13b of the trunk 13 in the horizontal direction X. By performing differential processing in the vertical direction Y on the portion of image 80 corresponding to the upper region 13b in the image processing section 53, described later, dark portions of the seam 16 and the uneven wall thickness 19 can be removed.

A light shielding plate can be used as the second light limiting unit 26. As the light shielding plate, a thin metal plate, for example, an iron plate can be used.

The second light restricting member 26 is fixed to the light emitting unit 20 at its end in the horizontal direction X by a bolt 28. The second light restricting member 26 has two elongated holes 264 at its upper and lower sides. The second light restricting member 26 can be moved in the vertical direction Y by loosening the bolts 28, and its position can be adjusted to match the height of the container 10.

5. Rotating support part

1 , the rotation support 30 and the side rollers 32 rotate the container 10 around the axis 12. The rotation support 30 supports the bottom 14 of the container 10. The axis 12 is an imaginary line that serves as the central axis of rotation of the container 10.

The rotating support 30 may also be a member for transporting the container 10 to a predetermined position for inspection as shown in Figures 1 and 2 while supporting the container 10. In this case, the container 10 is sequentially and intermittently transported by the rotating support 30 to the predetermined position for inspection, and after being positioned at the predetermined position, the container 10 is rotated about the axis 12.

According to the instruction of the rotation control unit 62, the driving force of the motor 60 is transmitted to the rotation support unit 30 and the side rollers 32 via the belt 35, etc., and the rotation support unit 30 rotates. When the container 10 is transported to the inspection position, the rotation support unit 30 rotates a predetermined amount at a predetermined speed. The predetermined amount of rotation is sufficient to capture the entire circumference of the container 10. In order to grasp the entire inspection object with one image data, the predetermined amount of rotation is set to more than 1.2 turns. The rotation amount of the rotation support unit 30 is calculated by the control unit 50 based on the output of the rotation detection unit 54. The rotation detection unit 54 can be a rotary encoder directly or indirectly mounted on the motor 60.

6. Photography Department

As shown in FIG1 , the imaging unit 40 is disposed opposite the light emitting unit 20 across the container 10. The imaging unit 40 is configured to image the surface of the container 10 on the axis 12. The imaging unit 40 is configured to image at least the inspection target portion of the container 10, and is here configured so that the entire body portion 13 of the container 10 in the vertical direction Y is within the field of view of the imaging unit 40.

The imaging unit 40 can capture an image of the test object (including the thin bubble 18) using light transmitted through the light emitting unit 20 of the container 10. For example, a known line sensor camera can be used for the imaging unit 40. The imaging unit 4 matches the rotation speed of the rotating support 30 based on the output of the rotation detection unit 54 to perform imaging. Therefore, even if the rotation speed changes for some reason, this does not affect the image 80.

The imaging unit 40 captures the entire circumference of the trunk portion 13 and transmits the resulting data to the image processing unit 53 of the control unit 50, which then performs predetermined processing on the image 80. As shown in FIG3 , in the image 80 before image processing, a striped pattern extending in the horizontal direction X appears in the portion corresponding to the area 13a below the trunk portion 13. This is due to the light reduction portion 242 and light transmission portion 244 of the first light limiting unit 24 shown in FIG1 and FIG2 .

In the portion of image 80 corresponding to lower region 13a, the first light limiting member 24 causes most of the light diffused in the horizontal direction X to illuminate the trunk portion 13, while limiting the light diffused in the vertical direction Y from illuminating the lower region 13a of the trunk portion 13. Therefore, the shadow of joint 16 is hardly visible in image 80. Joint 16 and uneven wall thickness 19 in upper region 13b, corresponding to second light limiting member 26, which does not have a structure similar to first light limiting member 24, appear in image 80.

The image processing unit 53 can perform a known grayscale conversion process on the image 80 in the vertical direction Y to eliminate the streaked pattern caused by the first light limiting unit 24, and can perform a known grayscale conversion process on the image 80 in the horizontal direction X to eliminate the shadows of the seam 16 and the uneven wall thickness 19 in the upper region 13b. Examples of grayscale conversion processes that can be used include shading correction, grayscale conversion based on differences from a reference image, and dynamic thresholding (dynamic binarization). For example, Keyence's real-time shading correction can be used as a grayscale conversion process. Real-time shading correction corrects for variations in background brightness in image data that may occur due to factors such as the lighting conditions of the container 10 being inspected. For example, if the portion of the image 80 corresponding to the bottom 14 is darker than the main body 13, real-time shading correction can be used to correct the brightness to a uniform average across the entire image.

Therefore, it is possible to accurately distinguish between the thin bubbles 18 and the joints 16 and the uneven wall thickness 19, and it is possible to more accurately detect the presence of the thin bubbles 18.

7. Judgment Department

As shown in FIG1 , the determination unit 52 is part of the control unit 50. Therefore, the control unit 50 instructs the subsequent processing of the inspected container 10 based on the determination result of the determination unit 52. The determination unit 52 may also be provided independently of the control unit 50. In this case, the determination result of the determination unit 52 is notified to the control unit 50.

The determination unit 52 will be described in further detail using Figures 6 and 7. Figure 6 illustrates the appearance of the contours 18a to 18d of the thin bubble 18 in the captured image, and Figure 7 illustrates the inspection mode used by the determination unit 52. Figures 6 and 7 show the contours 18a to 18d of the thin bubble 18 after the image processing unit 53 has performed differential processing in the vertical direction Y and the horizontal direction X on the image 80 of Figure 3 .

Inspection of many containers 10 revealed the presence of four types of contours 18a to 18d. Figure 6 schematically illustrates a circular contour 18a, a segmented contour 18b, an arc-shaped contour 18c, and a bright portion 18d. The determination unit 52 has an inspection technique for identifying the four types of contours 18a to 18d as defects (thin bubbles 18).

Based on the processed image data, the determination unit 52 identifies a portion darker than its surroundings as a test object, for example, by determining the brightness of the image. The determination unit 52 then performs all of the following determination processing on each test object. Containers 10 identified as defective by the determination unit 52 are then determined as defective, and the control unit 50 directs the container 10 to the discharge line.

7-1. Ring-shaped outline

The circular outline 18a in the upper left corner of Figure 6 indicates that the detected object has a continuous circular shape. As shown in Figure 7, the determination unit 52 can identify at least one detected object from the captured image 80 (Figure 3). If the detected object has a continuous circular shape, it can be determined as a defect based on the area associated with the detected object. This determination allows the detected object with the circular outline 18a to be determined as a defect, and the container 10 with the defect to be determined as a defective product.

If the test object has an annular contour 18a, an inspection area 81 is set to completely encompass the annular contour 18a. If the area obtained by adding the area of the annular contour 18a within the inspection area 81 to the area of the range surrounded by the annular contour 18a is greater than a predetermined threshold, the annular contour 18a is determined to be a defect, and the container 10 is determined to be defective. This is because if only the area of the annular contour 18a is used to determine whether it is a defect (thin bubble), even a small area of the test object caused by uneven wall thickness 19 that remains even after image processing may be determined as a defect, and this is to be prevented.

7-2. Segmented outline

The two segmented contours 18b in the middle of Figure 6 represent the detected object's shape being segmented into multiple parts. The segmented contour 18b on the left is segmented into two, and the segmented contour 18b on the right is segmented into four. This segmentation makes it impossible to identify the circular contour 18a, necessitating a different process than described in step 7-1 above.

As shown in FIG7 , the determination unit 52 can identify at least one detected object (segmented outline 18 b ) from the captured image 80 ( FIG3 ), and set a vertical inspection area 82 extending in the vertical direction Y and a horizontal inspection area 84 extending in the horizontal direction X within a predetermined range encompassing the identified detected object. If two or more detected objects (segmented outlines 18 b ) are included in the vertical inspection area 82 and the horizontal inspection area 84, the object is determined to be a defect. Detected objects whose outlines are divided into multiple parts can also be determined to be defects.

For example, the width of the vertical inspection area 82 in the horizontal direction X is set to match the width of one divided outline 18 b in the horizontal direction X, and the height of the vertical inspection area 82 in the vertical direction Y is set to match the height of three divided outlines 18 b arranged in an array.

The height of the horizontal inspection area 84 in the vertical direction Y is set to match one divided outline 18 b , and the width of the horizontal inspection area 84 in the horizontal direction X is set to match the width of three divided outlines 18 b arranged in an array.

7-3. Arc-shaped outline

The arc-shaped outline 18c on the left side of the lower row of Fig. 6 is a detected object having an arc-shaped shape. For this arc-shaped outline 18c, a process different from that in 7-1 and 7-2 above is required.

As shown in FIG7 , the determination unit 52 can identify at least one test object from the captured image 80 ( FIG3 ). If the identified test object is an arcuate test object, the determination unit 52 can determine that the test object is a defect based on the area associated with the test object (arc-shaped outline 18 c). This determination allows the test object having the arc-shaped outline 18 c to be determined as a defect, and the container 10 having the defect to be determined as a defective product.

If the test object has an arcuate contour 18c, a circumscribed inspection area 85 is defined that circumscribes the arcuate contour 18c. If the area ratio between the area of the arcuate contour 18c and the area of the circumscribed inspection area 85 exceeds a predetermined threshold, the arcuate contour 18c is determined to be a defect, and the container 10 is determined to be unacceptable. This is because if only the area of the arcuate contour 18c is used to determine whether a defect (thin bubble) is present, even small areas of the test object due to uneven wall thickness 19 that remain even after image processing may be determined as defects, and this is to be prevented.

7-4. Bright part

The bright portion 18d on the right side of the lower row of FIG. 6 is a portion having a brightness equal to or higher than a predetermined threshold value near the detection object (for example, the annular outline 18a).

As shown in FIG7 , the determination unit 52 can identify at least one detection object (e.g., annular outline 18a) from the captured image 80 ( FIG3 ) and determine that the container 10 is defective if a portion (bright portion 18d) with a brightness exceeding a predetermined threshold value is included within a predetermined range encompassing the identified detection object. A detection object containing both bright and dark outlines can also be determined as a defect. This is because, while dirt and the like may have only dark portions, shapes like thin bubbles 18 may also have bright portions 18d. Therefore, even thin bubbles 18 with a small outline can still be identified as such.

The type of the detection object may be a divided outline 18b or an arc-shaped outline 18c.

8. Inspection methods

The inspection method for a container 10 according to the present embodiment is characterized in that light emitted from the light emitting portion 20 and light that has passed through a dimming portion 242 that limits the angle of incidence of the light from the light emitting portion 20 relative to the vertical direction Y using a louver 243 extending in the horizontal direction X are alternately directed toward the container 10 in the vertical direction Y, an image 80 of the container 10 is captured using a camera 40 that is arranged to face the light emitting portion 20 across the container 10, and bubbles on the inner surface 15 of the container 10 are determined to be defects.

According to the method for inspecting the container 10 , the presence of a test object such as a thin bubble 18 with unclear outline can be inspected by utilizing the change in brightness in the vertical direction of the container surface caused by the light transmitting portion and the light reducing portion.

1 to 8 , an inspection method using the inspection device 1 will be described. FIG8 is a flowchart of the inspection method for the container 10 .

S10: The control unit 50 issues a command to the rotation control unit 62 to drive the motor 60, rotating the rotation support 30 and the side rollers 32 at a predetermined speed. The rotation of the rotation support 30 and the side rollers 32 causes the container 10 conveyed to the inspection position to rotate about the axis 12.

S20: The control unit 50 issues a command to start imaging to the imaging unit 40. Following the command from the control unit 50, the imaging unit 40 calculates the rotation angle of the container 10 based on the output from the rotation detector 54 and images the entire circumference of the trunk portion 13.

S30: The control unit 50 instructs the image processing unit 53 to store the image 80 in a storage unit (not shown). The image processing unit 53 stores the image 80 of at least one circumference (eg, 1.5 circumferences) of the container 10.

S40: The control unit 50 causes the determination unit 52 to determine whether the stored image 80 contains a specimen. If the determination result indicates that the specimen is not present in the image 80, the determination unit 52 terminates processing and the container 10 is conveyed to the next process step as a qualified product. Alternatively, if the determination result indicates that the specimen is present in the image 80, the following four inspection algorithms are executed.

S50 (First Inspection Algorithm): The determination unit 52 identifies at least one detection object from the captured image 80. If the detected detection object is a continuous ring (ring-shaped outline 18a), the detection object is determined to be a defect based on the area associated with the detection object. The details of the inspection are as described in 7-1 above and are omitted here.

S60 (Second Inspection Algorithm): The determination unit 52 identifies at least one test object (segmented outline 18b) from the captured image 80. A vertical inspection region 82 extending in the vertical direction Y and a horizontal inspection region 84 extending in the horizontal direction X are set within a predetermined range encompassing the identified test object. If two or more test objects (segmented outlines 18b) are included within the vertical inspection region 82 and the horizontal inspection region 84, the test object is determined to be defective. Details of the inspection are as described above in 7-2 and are therefore omitted.

S70 (Third Inspection Algorithm): The determination unit 52 identifies at least one detection object from the captured image 80 ( FIG. 3 ). If the detected detection object is arcuate, the detection object is determined to be a defect based on the area associated with the detection object (arc-shaped outline 18 c ). Details of the inspection are as described in 7-3 above and are omitted here.

S80 (Fourth Inspection Algorithm): The determination unit 52 identifies at least one detection object (e.g., annular outline 18a) from the captured image 80. If a portion (bright portion 18d) with a brightness exceeding a predetermined threshold value is included within a predetermined range encompassing the identified detection object, the detection object is determined to be a defect. Details of the inspection are as described in 7-4 above and are omitted here.

S90: When the determination unit 52 determines that the test body is defective through any one of the first inspection algorithm to the fourth inspection algorithm, the discharge process (S100) is performed. When the test body is determined not to be defective, the process of the determination unit 52 is terminated, and the control unit 50 transports the container 10 to the next process.

S100: The control unit 50 discharges the container 10 determined by the determination unit 52 to be a defective defective product from a discharge unit (not shown) that is different from the conveyance path to the next step.

The present invention is not limited to the above-mentioned embodiments and can be further modified in various ways. For example, the present invention includes a configuration that is substantially the same as the configuration described in the embodiment (for example, a configuration with the same function, method and result or a configuration with the same purpose and effect). In addition, the present invention includes a configuration in which a non-essential part of the configuration described in the embodiment is replaced. In addition, the present invention includes a configuration that has the same effect as the configuration described in the embodiment or a configuration that can achieve the same purpose. In addition, the present invention includes a configuration in which a known technology is added to the configuration described in the embodiment.

Description of Reference Numerals

1…Inspection device, 10…Container, 11…Mouth, 12…Axis, 13…Main body, 13a…Lower area, 13b…Upper area, 14…Bottom, 15…Inner surface, 16…Joint, 18…Thin bubble, 18a…Annular outline, 18b…Separated outline, 18c…Arcuate outline, 18d…Bright portion, 19…Uneven wall thickness, 20…Luminous portion, 22…Luminous surface, 24…First light limiting portion, 242…Light-reducing portion, 243…Louvre, 244…Light transmission Shooting unit, 246…long hole, 26…second light limiting unit, 264…long hole, 28…bolt, 30…rotation support unit, 32…side roller, 35…belt, 40…shooting unit, 50…control unit, 52…judgment unit, 53…image processing unit, 54…rotation detection unit, 60…motor, 62…rotation control unit, 80…image, 81…inspection area, 82…vertical inspection area, 84…horizontal inspection area, 85…circumscribed inspection area, H1…specified height position, H2…height, W…width.

Claims (8)

1. A container inspection device, characterized in that it comprises: The light-emitting part has a light-emitting surface that irradiates light onto the container; The imaging unit is configured to face the aforementioned light-emitting unit across the container; The determination unit determines whether there is a defect based on the image of the container captured by the aforementioned imaging unit; and A light-limiting part is disposed on the container side of the light-emitting part. The aforementioned light-limiting portion includes a light-transmitting portion and a light-reducing portion extending horizontally along the aforementioned light-emitting surface. The aforementioned light-transmitting parts and the aforementioned light-reducing parts are arranged alternately in the vertical direction. The aforementioned light-transmitting section allows light emitted from the aforementioned light-emitting section to be transmitted toward the container side. The aforementioned light-reducing section has a plurality of louvers extending in the horizontal direction in the aforementioned vertical direction, which restrict the incident angle of the light emitted from the aforementioned light-emitting section relative to the aforementioned vertical direction. The vertical width of the light-transmitting section is 3mm to 6mm, and is wider than the spacing between the adjacent louvers in the light-reducing section. 2. The container inspection device according to claim 1, characterized in that, The light-reducing part is disposed on the light-emitting surface of the light-emitting part, and the height of the light-reducing part from the light-emitting surface is 0mm to 100mm. 3. The container inspection device according to claim 1 or 2, characterized in that, The aforementioned light-reducing section is formed by overlapping multiple light control films. 4. The container inspection device according to claim 1 or 2, characterized in that, The aforementioned light-limiting part is a first light-limiting part disposed at a position corresponding to a region below the specified height position in the vertical direction of the container. At a position corresponding to the area above the specified height on the container side of the light-emitting part, a second light-limiting part is also included to reduce the amount of light transmitted from the light-emitting part. The two aforementioned second light limiting parts are configured to have a predetermined interval in the aforementioned horizontal direction. 5. The container inspection device according to claim 1 or 2, characterized in that, The aforementioned determination unit identifies at least one detection object from the captured image, and sets up a vertical inspection area extending in the vertical direction and a horizontal inspection area extending in the horizontal direction within a predetermined range that includes the identified detection object. When there are two or more detection objects in the vertical inspection area and the horizontal inspection area, it is determined to be a defect. 6. The container inspection device according to claim 1 or 2, characterized in that, The aforementioned determination unit identifies at least one detection object from the captured image. If the identified detection object is a ring-shaped or arc-shaped detection object, it determines it to be a defect based on the area associated with the detection object. 7. The container inspection device according to claim 1 or 2, characterized in that, The aforementioned determination unit identifies at least one detector from the captured image, and if the identified detector is included in a specified range containing a portion with a brightness above a specified threshold, it determines it to be a defect. 8. A method for inspecting a container, characterized in that, It includes: light emitted from the light-emitting part that passes through a light-transmitting part with a vertical width of 3mm to 6mm and light that has passed through a light-reducing part that limits the incident angle of the light from the light-emitting part relative to the vertical direction using louvers that extend in the horizontal direction, alternately irradiating the container in the vertical direction. An image of the container is captured using a camera configured to be positioned opposite the light-emitting part across the container. The process of identifying bubbles on the inner surface of a container as defects. The aforementioned louvers are arranged in multiple vertical directions. The vertical width of the light-transmitting section is wider than the spacing between the adjacent louvers in the light-reducing section.