Damage inspection device

Abstract

This damage inspection device (31) inspects a container (11) that has an opening part (14) in which an opening is formed, said inspection device (31) comprising: a light source (34) that irradiates the container with ultraviolet light; an imaging unit (35) that images the container using fluorescence which is emitted from the container due to the ultraviolet light; and an inspection circuit (38) that inspects the container on the basis of a captured image which has been captured by the imaging unit, wherein the imaging unit has an optical filter (37) that blocks ultraviolet light and a camera (36) that images the container through the optical filter, and the camera is positioned so as to receive, through the opening, the fluorescence emitted from the opening part.

Description

Scratch inspection equipment

[0001] The present invention relates to a flaw inspection device.

[0002] Patent Document 1 describes an inspection device for inspecting the mouth of a container. The inspection device includes an imaging unit that captures an image of the container using light that passes through the container. The inspection device determines whether or not there is a scratch on the outer surface of the mouth based on the image captured by the imaging unit.

[0003] JP 2012-103020 A

[0004] In the inspection device described in Patent Document 1, the imaging unit images the container from the side of the container. That is, the imaging unit images the container so that the front portion of the container facing the imaging unit overlaps with the back portion of the container opposite the front portion. This may make it difficult for the inspection device to determine from the image whether or not there is a scratch on the outer surface of the opening.

[0005] A flaw inspection device that solves the above problem is a flaw inspection device for inspecting a container having a mouth portion with an opening, and includes a light source that irradiates the container with ultraviolet light, an imaging unit that images the container using fluorescence emitted from the container in response to the ultraviolet light, and an inspection circuit that inspects the container based on the image captured by the imaging unit. The imaging unit has an optical filter that blocks ultraviolet light and a camera that images the container through the optical filter, and the camera is positioned to receive the fluorescence emitted from the mouth portion through the opening. If there is a flaw on the outer surface of the mouth portion, the fluorescence generated at the mouth portion is reflected by the flaw. As a result, the fluorescence is more likely to be emitted from the inner surface of the mouth portion. With the above configuration, because the camera is positioned to receive the fluorescence emitted from the mouth portion through the opening, flaws on the outer surface of the mouth portion are more likely to appear in the captured image. Therefore, the inspection device can easily determine the presence or absence of flaws on the outer surface of the mouth portion from the captured image. Therefore, the inspection device can easily inspect the presence or absence of flaws on the outer surface of the mouth portion.

[0006] In the flaw inspection device, the camera may be positioned so that the fluorescence emitted from the opening portion directly enters the camera. With this configuration, the inspection device can more easily obtain a clearer image than when, for example, the fluorescence emitted from the inner surface is reflected by a mirror and then enters the camera.

[0007] In the flaw inspection device, the camera may be positioned so that its optical axis is inclined with respect to an axis extending through the center of the mouth. According to the above configuration, the camera captures an image of the container by looking into the inside surface of the mouth. This makes it easier for the inspection device to obtain an image that captures the inside surface of the mouth.

[0008] The flaw inspection device may include a plurality of cameras, and the camera may be one of the plurality of cameras, and the plurality of cameras may be positioned to surround an axis extending through the center of the mouth portion. With the above configuration, the plurality of cameras increases the imaging range of the inner surface of the mouth portion, thereby increasing the range for determining flaws on the outer surface of the mouth portion.

[0009] In the above-described flaw inspection device, the opening portion may include a cylindrical portion having an outer peripheral surface and a protruding portion extending along the outer peripheral surface, the cylindrical portion having an edge forming an opening, and the inspection circuit may extract an inspection area surrounded by the edge from the captured image, identify a protrusion area representing the protrusion portion and an outer peripheral surface area representing the non-protrusion portion in the inspection area, and determine the presence or absence of a flaw in each of the protrusion area and the outer peripheral surface area based on a threshold value determined for each identified area. The protrusion area tends to appear brighter than the outer peripheral surface area. Therefore, if the inspection circuit determines the presence or absence of a flaw using a common threshold value for both the protrusion area and the outer peripheral surface area, the accuracy of the determination may decrease. According to the above configuration, the inspection circuit determines the presence or absence of a flaw in each of the protrusion area and the outer peripheral surface area based on a threshold value determined for each area, thereby improving the accuracy of the determination.

[0010] In the above-described flaw inspection device, the protrusion portion may have a threaded portion for attaching a lid that closes the mouth portion and a support portion that supports the lid, and the inspection circuit may identify a threaded region indicating the threaded portion and a support region indicating the support portion in the protrusion region, and determine the presence or absence of a flaw in each of the outer circumferential surface region, the threaded region, and the support region based on a threshold value determined for each identified region. A lid may be attached to a container to close the mouth portion. Therefore, the mouth portion may have a threaded portion and a support region. The threaded region and the support region are likely to have different light intensities. Therefore, with the above configuration, the inspection circuit determines the presence or absence of a flaw in each of the outer circumferential surface region, the threaded region, and the support region based on a threshold value determined for each region, thereby improving the accuracy of the determination.

[0011] In the flaw inspection device, the inspection circuit may distinguish between a tip region indicating the tip of the thread portion and an extension region indicating the portion of the thread portion other than the tip in the thread region, and determine the presence or absence of flaws in each of the outer circumferential surface region, the tip region, the extension region, and the support region based on a threshold value determined for each distinguished region. The tip region tends to appear brighter than the extension region. Therefore, with the above configuration, the inspection circuit determines the presence or absence of flaws in each of the outer circumferential surface region, the tip region, the extension region, and the support region based on a threshold value determined for each region, thereby improving the accuracy of the determination.

[0012] According to the present invention, the scratch inspection device can inspect the opening of a container with high accuracy for scratches.

[0013] FIG. 1 is a side view of a container. FIG. 2 is a top view of a container. FIG. 3 is a side view showing one embodiment of a scratch inspection device. FIG. 4 is a top view of the scratch inspection device. FIG. 5 is a cross-sectional view of a mouth portion. FIG. 6 is an image captured using fluorescent light. FIG. 7 is an image captured of a container different from that shown in FIG. 6. FIG. 8 is an image captured of a container different from that shown in FIGS. 6 and 7. FIG. 9 is an image captured after inspection processing has been performed. FIG. 10 is a flowchart showing an example of inspection processing. FIG. 11 is an image showing a comparative example of a captured image. FIG. 12 is an image showing a comparative example of a container different from that shown in FIG. 11. FIG. 13 is a side view showing a modified example of the scratch inspection device. FIG. 14 is a top view of the scratch inspection device shown in FIG. 13. FIG. 15 is a side view showing another modified example different from that shown in FIG. 13. FIG. 16 is a top view of the scratch inspection device shown in FIG. 15.

[0014] An embodiment of a scratch inspection device will be described below with reference to the drawings. The scratch inspection device is a device that inspects the appearance of a container. More specifically, the scratch inspection device inspects the presence or absence of scratches on the outer surface of a container. In the following description, the scratch inspection device will be simply referred to as the inspection device.

[0015] <Container> First, the container to be inspected by the inspection device will be described. As shown in FIG. 1 , the container 11 has a cylindrical shape. In one example, the container 11 has a cylindrical shape. The container 11 may also have a cylindrical shape with a polygonal bottom. The container 11 may be made of a transparent material. The container 11 may be made of, for example, a transparent resin material. Therefore, visible light passes through the container 11. In one example, the container 11 is a plastic bottle. The container 11 may also be made of a translucent material. The container 11 is not limited to a resin material and may be made of other materials, such as fluorescent glass. Although a plastic bottle is preferred as the container 11, other transparent or translucent containers may also be used, such as a fluorescent glass bottle. The container 11 may also be configured so that a lid 12 can be attached. The container 11 is inspected without the lid 12 attached.

[0016] As shown in Figures 1 and 2, the container 11 has a body portion 13. The body portion 13 is a portion into which the contents are filled. After inspection of the container 11, the body portion 13 is filled with, for example, a beverage. In one example, the body portion 13 has a cylindrical shape. The body portion 13 is not limited to a cylindrical shape, and may be a rectangular tube shape or another shape.

[0017] The container 11 has a mouth portion 14. The mouth portion 14 is a portion that connects to the body portion 13. The body portion 13 is filled with contents through the mouth portion 14. The mouth portion 14 has a cylindrical shape. The mouth portion 14 extends along an axis A1. The axis A1 is the central axis of the mouth portion 14. In one example, the body portion 13 also extends along the axis A1. The axis A1 may coincide with the central axis of the body portion 13.

[0018] The mouth portion 14 has an outer surface 15. The outer surface 15 is a surface that faces outward in the mouth portion 14. The outer surface 15 is a surface that has projections and depressions. The mouth portion 14 has an inner surface 16. The inner surface 16 is a surface that faces inward in the mouth portion 14. The inner surface 16 is a surface opposite to the outer surface 15 in the mouth portion 14. Compared to the outer surface 15, the inner surface 16 is a uniform surface without projections and depressions.

[0019] The mouth portion 14 has a cylindrical portion 17. The cylindrical portion 17 is a portion of the mouth portion 14 that extends along the axis A1. An opening 18 is formed in the cylindrical portion 17. The opening 18 is formed in a circular shape centered on the axis A1. The cylindrical portion 17 has a rim 19 that forms the opening 18. The rim 19 is a portion that is annular about the axis A1. The rim 19 is located at the tip of the cylindrical portion 17.

[0020] The cylindrical portion 17 has an outer peripheral surface 20. The outer peripheral surface 20 is the surface of the cylindrical portion 17 that faces outward. The outer peripheral surface 20 constitutes the outer side surface 15. More specifically, the outer peripheral surface 20 is the portion of the outer side surface 15 excluding the surface of a protruding portion 21, which will be described later. The cylindrical portion 17 has an inner peripheral surface. The inner peripheral surface coincides with the inner side surface 16.

[0021] The mouth portion 14 has a protruding portion 21. The protruding portion 21 is a portion that protrudes from the outer peripheral surface 20. The protruding portion 21 protrudes in the radial direction around the axis A1. The surface of the protruding portion 21 forms the outer surface 15. The protruding portion 21 forms unevenness on the outer surface 15. The protruding portion 21 extends in the circumferential direction around the axis A1. The protruding portion 21 extends on the outer peripheral surface 20 so as to form a ring or an arc around the axis A1.

[0022] The protruding portion 21 may include a threaded portion 22. The threaded portion 22 is a portion that engages with the lid 12. The lid 12 is attached to the container 11 by engaging the threaded portion 22 with the lid 12. The threaded portion 22 extends, for example, in an arc shape on the outer circumferential surface 20. The threaded portion 22 may also extend in a spiral shape.

[0023] The threaded portion 22 has a tip portion 23. The tip portion 23 is a portion located at the tip of the threaded portion 22. More specifically, the tip portion 23 is a portion located at the tip of the threaded portion 22 in the circumferential direction.

[0024] The threaded portion 22 has an extending portion 24. The extending portion 24 is a portion of the threaded portion 22 other than the tip. More specifically, the extending portion 24 is a portion of the threaded portion 22 that extends in the circumferential direction. The extending portion 24 is connected to the tip portion 23.

[0025] The protruding portion 21 may include a support portion 25. The support portion 25 is a portion that supports the lid 12. The support portion 25 supports the lid 12 that is attached to the mouth portion 14. The support portion 25 extends in an annular shape on the outer circumferential surface 20, for example.

[0026] Scratches 26 may occur on the outer surface 15 of the container 11. That is, scratches 26 may occur on the surface of the cylindrical portion 17 and the surface of the protruding portion 21. The scratches 26 may occur, for example, when the containers 11 come into contact with each other or when the container 11 comes into contact with various devices.

[0027] If the container 11 is a plastic beverage bottle, the mouth 14 may come into contact with the user's mouth. In particular, the outer surface 15 is likely to come into contact with the user's mouth. If there are scratches 26 on the outer surface 15, this will affect the mouthfeel. Therefore, it is important to inspect the outer surface 15 for scratches 26.

[0028] <Inspection Device> Next, the inspection device will be described. As shown in FIGS. 3 and 4 , the inspection device 31 may include a transport device 32. The transport device 32 is configured to transport the container 11. The transport device 32 has, for example, a conveyor. The transport device 32 transports the container 11 by the conveyor. The transport device 32 is not limited to a conveyor, and may transport the container 11 by, for example, a robot arm. In one example, the transport device 32 transports the container 11 in an upright position. More specifically, the transport device 32 transports the container 11 in an position where the opening 18 faces upward. The transport device 32 may also transport the container 11 in an orientation where the container 11 is lying on its side. The transport device 32 may also transport the container 11 in an orientation where the opening 18 faces sideways.

[0029] The conveying device 32 conveys the container 11 so that the container 11 passes through an inspection position P1. The inspection position P1 is a position where the container 11 is inspected. More specifically, the inspection position P1 is a position where the container 11 is imaged by an imaging device 33, which will be described later. The conveying device 32 may temporarily stop the container 11 at the inspection position P1. The inspection position P1 may be, for example, on a workbench. In this case, the container 11 may be placed at the inspection position P1 by an operator.

[0030] The inspection device 31 includes an imaging device 33. The imaging device 33 is configured to capture an image of the container 11. The imaging device 33 is configured to capture an image of the container 11 using fluorescent light emitted from the container 11. The imaging device 33 is configured to cause the container 11 to emit fluorescent light, and to receive the fluorescent light.

[0031] The imaging device 33 has one or more light sources 34. In one example, the imaging device 33 has one light source 34. The light source 34 is configured to emit ultraviolet light. In one example, the light source 34 is a ring light. The light source 34 may also be a bar light. The light source 34 has, for example, an LED with a peak wavelength of 365 nm. The light source 34 may be configured to emit visible light or infrared light in addition to ultraviolet light. It is sufficient that the light source 34 is configured to emit at least ultraviolet light.

[0032] The light source 34 is positioned to irradiate the container 11 with ultraviolet light. The light source 34 is positioned to irradiate the mouth portion 14 with ultraviolet light. The light source 34 is positioned, for example, on the axis A1 of the container 11 positioned at the inspection position P1. The light source 34 is positioned so that the distance between the light source 34 and the mouth portion 14 on the axis A1 is smaller than the distance between the light source 34 and the body portion 13. In one example, the light source 34 is positioned directly above the container 11 positioned at the inspection position P1.

[0033] As shown in Fig. 5, the container 11 emits fluorescence when exposed to ultraviolet light. Specifically, the molecules constituting the container 11 are excited by the ultraviolet light. The molecules then transition from the excited state to the ground state. At this time, fluorescence is generated in the container 11.

[0034] The wavelength of the fluorescence is longer than the wavelength of ultraviolet light. For example, when the container 11 is exposed to ultraviolet light, it emits fluorescence with a visible light wavelength. In one example, when the container 11 is exposed to ultraviolet light, it emits blue light. Specifically, the container 11 emits fluorescence with a wavelength of 400 nm or more and 500 nm or less.

[0035] Fluorescence is generated inside the container 11. In particular, when the light source 34 irradiates the mouth portion 14 with ultraviolet light, fluorescence is likely to be generated inside the mouth portion 14. The fluorescence is reflected from the point indicated by the black circle in FIG. 5 as shown by the arrow. That is, the fluorescence is reflected by the scratches 26. When the outer surface 15 has scratches 26, the fluorescence is likely to be reflected by the outer surface 15. More specifically, when the outer surface 15 has scratches 26, the angle of incidence of the fluorescence with respect to the outer surface 15 is likely to be large, and the reflectance of the fluorescence at the outer surface 15 is therefore large. This increases the amount of fluorescence reflected at the outer surface 15. As a result, the fluorescence is likely to be emitted from the inner surface 16. Therefore, when the outer surface 15 has scratches 26, the amount of fluorescence emitted from the inner surface 16 is large.

[0036] 3 and 4, the imaging device 33 includes an imaging unit 35. The imaging unit 35 is configured to capture an image of the container 11 using fluorescence emitted from the container 11 in response to ultraviolet light.

[0037] The imaging unit 35 has one or more cameras 36. In one example, the imaging unit 35 has a plurality of cameras 36. More specifically, the imaging unit 35 has six cameras 36.

[0038] The camera 36 is configured to capture an image of the container 11. The camera 36 is positioned so as to capture an image of the mouth portion 14. More specifically, the camera 36 is positioned so as to capture an image of the mouth portion 14 through the opening 18. The camera 36 is positioned so that the optical axis G1 of the camera 36 passes through the opening 18 and intersects with the inner surface 16. In one example, the camera 36 is positioned so as to look into the inside of the container 11 from above the container 11. In other words, the camera 36 is positioned so as to capture an image of the inner surface 16. The camera 36 outputs a captured image in which the inner surface 16 is captured.

[0039] The camera 36 is positioned so that the fluorescence emitted from the inner surface 16 directly enters the camera 36. In this case, the camera 36 can capture an image of the container 11 with higher accuracy than when the camera 36 receives fluorescence reflected by a mirror, for example.

[0040] The multiple cameras 36 are positioned to capture images of the inner surface 16 from multiple directions. The multiple cameras 36 are positioned, for example, symmetrically around the axis A1 of the container 11 positioned at the inspection position P1. In one example, six cameras 36 are positioned to surround the container 11 when viewed from the direction in which the axis A1 extends. Specifically, the six cameras 36 are positioned at 60-degree intervals around the axis A1 when viewed from the direction in which the axis A1 extends. This allows the imaging unit 35 to capture images of the inner surface 16 from multiple directions. Therefore, the imaging range of the imaging unit 35 is increased. When the imaging unit 35 has four cameras 36, the four cameras 36 are preferably positioned at 90-degree intervals around the axis A1 when viewed from the direction in which the axis A1 extends.

[0041] The camera 36 captures an image of the container 11 using the fluorescence emitted from the container 11. The camera 36 is configured to be sensitive to fluorescence. In one example, the camera 36 is configured to be sensitive to blue light. More specifically, the camera 36 is configured to be sensitive to light between 400 nm and 500 nm. That is, the camera 36 is configured to be sensitive to visible light. The camera 36 is, for example, a monochrome camera capable of capturing monochrome images using blue light. The camera 36 has a light-receiving element sensitive to blue light. The camera 36 is not limited to a monochrome camera, and may be a color camera capable of capturing RGB color images. In this case, the camera 36 is configured to be sensitive to red light, green light, and blue light. The camera 36 may have a light-receiving element sensitive to red light, a light-receiving element sensitive to green light, and a light-receiving element sensitive to blue light. The camera 36 is only required to be sensitive to at least fluorescence.

[0042] The imaging unit 35 has one or more optical filters 37. In one example, the imaging unit 35 has a plurality of optical filters 37. More specifically, the imaging unit 35 has the same number of optical filters 37 as the number of cameras 36. The imaging unit 35 has six optical filters 37.

[0043] The optical filter 37 is positioned between the container 11 located at the inspection position P1 and the camera 36. The optical filter 37 is positioned on the optical axis G1. The optical filter 37 is configured to transmit fluorescent light. The camera 36 captures an image of the container 11 through the optical filter 37.

[0044] The optical filter 37 is configured to block ultraviolet light. The optical filter 37 blocks ultraviolet light so that it does not enter the camera 36. The wavelength range of the ultraviolet light emitted by the light source 34 and the wavelength range of the fluorescence emitted by the container 11 may overlap with each other. Therefore, the camera 36 may be configured to be sensitive to fluorescence, and may also be sensitive to ultraviolet light. Generally, monochrome cameras and color cameras are sensitive not only to visible light but also to ultraviolet light. By blocking ultraviolet light with the optical filter 37, the camera 36 can accurately capture an image of the container 11 using fluorescence. The optical filter 37 may be a cutoff filter that blocks light of 400 nm or less.

[0045] The optical filter 37 may be configured to block other light in addition to ultraviolet light. The optical filter 37 may be configured to block, for example, light other than fluorescence. The optical filter 37 may be configured to block red and green visible light, or may be configured to block infrared light. The optical filter 37 may be a bandpass filter that transmits light from 400 nm to 500 nm. In this case, the influence of ambient light on the imaging unit 35 is reduced. That is, the camera 36 can accurately capture images of the container 11 even in an environment where lighting other than the light source 34 is present. The inspection device 31 may inspect the container 11 in a dark place where the only illumination is the light source 34. In this case, the influence of visible light, infrared light, etc. on the imaging unit 35 is reduced. If the camera 36 is a monochrome camera, the optical filter 37 may be a bandpass filter that transmits light from 400 nm to 500 nm. If the camera 36 is a color camera, the optical filter 37 may be a cutoff filter that blocks light below 400 nm. This is because a color camera normally has a blue filter that blocks red light, green light, etc. from a light receiving element that is sensitive to blue light.

[0046] The inspection device 31 includes an inspection circuit 38. The inspection circuit 38 may be configured with one or more processors operating according to a computer program. The inspection circuit 38 may be configured with a dedicated hardware circuit that executes at least some of the various processes. The inspection circuit 38 may be configured with a circuit that includes a combination of a processor and a hardware circuit. The processor includes a CPU and memory such as RAM and ROM. The memory stores program code or instructions configured to cause the CPU to execute processes. The memory, i.e., computer-readable medium, includes any medium that can be accessed by a general-purpose or dedicated computer.

[0047] The inspection circuit 38 is configured to inspect the container 11 for the presence or absence of scratches 26. The inspection circuit 38 inspects the outer surface 15 for the presence or absence of scratches 26. The inspection circuit 38 inspects the container 11 for the presence or absence of scratches 26 based on the captured image.

[0048] As shown in Figures 6, 7, and 8, the captured image is a fluorescent image of the mouth portion 14. The inner surface 16 is captured in the captured image. In the region of the captured image where the inner surface 16 is captured, the scratch 26 occurring on the outer surface 15 appears bright. In the captured images shown in Figures 6, 7, and 8, the scratch 26 appears as a white streak or white dot. The inspection circuit 38 can determine the presence of the scratch 26 by detecting the bright portion in the region of the captured image where the inner surface 16 is captured.

[0049] The inspection circuit 38 determines whether or not a scratch 26 is present on the outer surface 15 based on the brightness of the captured image. Specifically, the inspection circuit 38 determines that a scratch 26 is present when the area of ​​the captured image that shows the inner surface 16 has a brightness greater than a threshold value. The inspection circuit 38 stores the threshold value in advance. The inspection circuit 38 may read the threshold value from another device.

[0050] Depending on the shape, structure, etc. of the mouth portion 14, the brightness may not be uniform in the region of the captured image where the inner surface 16 is captured. For example, in the region of the captured image where the inner surface 16 is captured, the region where the protruding portion 21 is captured is brighter than the region where everything other than the protruding portion 21 is captured. This is because the protruding portion 21 is more likely to reflect fluorescence than the cylindrical portion 17. Furthermore, the protruding portion 21 tends to have a larger volume than the cylindrical portion 17, and therefore tends to emit a larger amount of fluorescence. Therefore, in the region of the captured image where the inner surface 16 is captured, the region where the protruding portion 21 is captured is brighter than the region where everything other than the protruding portion 21 is captured. Furthermore, in the region of the captured image where the inner surface 16 is captured, the region where the thread portion 22 is captured is brighter than the region where the support portion 25 is captured. In the region of the captured image where the inner surface 16 is captured, the region where the tip portion 23 is captured is brighter than the region where the extension portion 24 is captured. Therefore, depending on the shape, structure, etc. of the mouth portion 14, it may be difficult to inspect for the presence or absence of scratches 26 based on a single threshold value.

[0051] The inspection circuit 38 may store in advance a plurality of thresholds set for each region. For example, the inspection circuit 38 may store a threshold corresponding to a region of the captured image in which the protruding portion 21 appears. The inspection circuit 38 may store a threshold corresponding to a region of the captured image in which parts other than the protruding portion 21 appear. The inspection circuit 38 may store a threshold corresponding to a region of the captured image in which the screw portion 22 appears. The inspection circuit 38 may store a threshold corresponding to a region of the captured image in which the support portion 25 appears. The inspection circuit 38 may store a threshold corresponding to a region of the captured image in which the tip portion 23 appears. The inspection circuit 38 may store a threshold corresponding to a region of the captured image in which the extension portion 24 appears. The inspection circuit 38 may read out the plurality of thresholds set for each region from another device.

[0052] 9, the inspection circuit 38 is configured to perform image processing on the captured image. The inspection circuit 38 identifies an inspection area 41 from the captured image. The inspection area 41 is an area in the captured image in which the inner surface 16 is captured. The inspection area 41 is an area to be inspected in the captured image. The inspection area 41 is an area surrounded by an edge 19 in the captured image. The inspection circuit 38 identifies the inspection area 41 by, for example, detecting the edge 19 from the feature amount of the captured image.

[0053] The inspection circuit 38 may divide the inspection area 41 into a plurality of areas. The inspection circuit 38 may identify a plurality of areas in the inspection area 41. The inspection circuit 38 may identify a protrusion area 42 and an outer peripheral surface area 43 in the inspection area 41. The protrusion area 42 is an area in which the protrusion portion 21 is captured. The outer peripheral surface area 43 is an area in which everything other than the protrusion portion 21 is captured. The outer peripheral surface area 43 can also be said to be an area in which the protrusion portion 21 is not captured. The inspection circuit 38 may, for example, detect the protrusion portion 21 from the feature amount of the captured image to identify the protrusion area 42 and the outer peripheral surface area 43. The inspection circuit 38 may also detect the edge of the protrusion portion 21 to identify the protrusion area 42 and the outer peripheral surface area 43.

[0054] The inspection circuit 38 may divide the protrusion region 42 into a plurality of regions. The inspection circuit 38 may identify a plurality of regions in the protrusion region 42. The inspection circuit 38 may identify a thread region 44 and a support region 45 in the protrusion region 42. The thread region 44 is a region in which the thread portion 22 is captured. The support region 45 is a region in which the support portion 25 is captured. The inspection circuit 38 may identify the thread region 44 and the support region 45 by detecting the thread portion 22 and the support portion 25 from feature amounts of the captured image, for example. The inspection circuit 38 may identify the thread region 44 and the support region 45 by detecting the edges of the thread portion 22 and the support portion 25.

[0055] The inspection circuit 38 may divide the thread region 44 into a plurality of regions. The inspection circuit 38 may identify a plurality of regions in the thread region 44. The inspection circuit 38 may identify a tip region 46 and an extension region 47 in the thread region 44. The tip region 46 is a region in which the tip portion 23 is captured. The extension region 47 is a region in which the extension portion 24 is captured. The inspection circuit 38 may identify the tip region 46 and the extension region 47 by detecting the tip portion 23 and the extension portion 24 from feature amounts of the captured image, for example. The inspection circuit 38 may identify the tip region 46 and the extension region 47 by detecting the edges of the tip portion 23 and the extension portion 24.

[0056] The inspection circuit 38 determines the presence or absence of scratches 26 in each region based on a threshold value set for each region. For example, the inspection circuit 38 may determine the presence or absence of scratches 26 in the protrusion region 42 based on a threshold value corresponding to the protrusion region 42. The inspection circuit 38 may determine the presence or absence of scratches 26 in the outer peripheral surface region 43 based on a threshold value corresponding to the outer peripheral surface region 43. The inspection circuit 38 may determine the presence or absence of scratches 26 in the threaded region 44 based on a threshold value corresponding to the threaded region 44. The inspection circuit 38 may determine the presence or absence of scratches 26 in the support region 45 based on a threshold value corresponding to the support region 45. The inspection circuit 38 may determine the presence or absence of scratches 26 in the tip region 46 based on a threshold value corresponding to the tip region 46. The inspection circuit 38 may determine the presence or absence of scratches 26 in the extension region 47 based on a threshold value corresponding to the extension region 47.

[0057] The inspection circuit 38 may extract, for each region, a location whose brightness is greater than a threshold value as a candidate location for the scratch 26. In this case, the inspection circuit 38 determines whether the candidate location for the scratch 26 is the scratch 26. For example, the inspection circuit 38 determines whether the candidate location for the scratch 26 is the scratch 26 based on the position, shape, etc. of the candidate location for the scratch 26. The container 11 may have a parting line from a mold created during manufacturing. Therefore, the parting line may appear bright in the captured image. The inspection circuit 38 may determine whether the candidate location for the scratch 26 is the parting line or the scratch 26.

[0058] <Inspection Processing> Next, an example of the inspection processing executed by the inspection circuit 38 will be described. The inspection processing is processing in which the inspection circuit 38 determines the presence or absence of scratches 26 based on a captured image. The inspection processing includes the image processing described above. The inspection circuit 38 executes the inspection processing, for example, by causing the CPU to execute a program stored in memory.

[0059] 10 , in step S11, the inspection circuit 38 identifies an inspection area 41 from the captured image. In step S12, the inspection circuit 38 identifies a plurality of areas in the inspection area 41. In one example, the inspection circuit 38 identifies a protrusion area 42, an outer peripheral surface area 43, a thread area 44, a support area 45, a tip area 46, and an extension area 47 in the inspection area 41.

[0060] In step S13, the inspection circuitry 38 reads out a plurality of thresholds determined for each of the identified regions. In one example, the inspection circuitry 38 reads out a threshold value for the outer peripheral surface region 43, a threshold value for the support region 45, a threshold value for the tip region 46, and a threshold value for the extension region 47.

[0061] In step S14, the inspection circuit 38 determines whether there is a location in each region that exhibits a brightness greater than the threshold value. At this time, the inspection circuit 38 extracts candidate locations for the flaw 26. The inspection circuit 38 may determine, as the flaw 26, a location in each region that exhibits a brightness greater than the threshold value.

[0062] In step S15, the inspection circuit 38 determines whether the candidate location for the scratch 26 indicates the scratch 26. The inspection circuit 38 determines whether the candidate location extracted in step S14 indicates the scratch 26. This allows the inspection circuit 38 to accurately determine whether the scratch 26 is present. If the inspection circuit 38 determines that the scratch 26 is present, it may notify the manager of the inspection device 31 that it has been determined that the scratch 26 is present. This allows the manager to know that the container 11 has the scratch 26. The inspection circuit 38 may notify the manager of the position of the scratch 26.

[0063] Comparative Example Next, an image captured using transmitted light will be described as a comparative example. As shown in FIGS. 11 and 12 , the scratch 26 appears dark in the image captured using transmitted light. In FIGS. 11 and 12 , the scratch 26 appears as a black streak. The image captured in the comparative example was captured by the camera 36 from the side of the mouth portion 14. Therefore, in the captured image, the front portion of the container 11 facing the camera 36 overlaps the back portion of the container 11 opposite the front portion. This tends to reduce the brightness of the area capturing the mouth portion 14 in the captured image. Furthermore, the scratch 26 may appear to overlap the threaded portion 22 in the captured image. In this case, the brightness difference between the scratch 26 and the threaded portion 22 is reduced. Therefore, in the image captured using transmitted light, the inspection circuit 38 may have difficulty recognizing the scratch 26. In response to this issue, the inspection device 31 described above performs inspection based on an image captured of the mouth portion 14 in which the front portion of the container 11 and the back portion of the container 11 do not overlap, making it easier to recognize the scratch 26.

[0064] <Functions and Effects of the Example> Next, the functions and effects of the above-described example will be described. (1) The camera 36 is positioned so as to receive the fluorescence emitted from the mouth portion 14 through the opening 18. If a scratch 26 is present on the outer surface 15, the fluorescence generated at the mouth portion 14 is reflected by the scratch 26. As a result, the fluorescence is more likely to be emitted from the inner surface 16. According to the above configuration, the camera 36 is positioned so as to receive the fluorescence emitted from the mouth portion 14 through the opening 18, so that the scratch 26 generated on the outer surface 15 is more likely to appear in the captured image. Therefore, the inspection device 31 can easily determine the presence or absence of the scratch 26 on the outer surface 15 from the captured image. Therefore, the inspection device 31 can easily inspect the presence or absence of the scratch 26 on the outer surface 15.

[0065] (2) The camera 36 is positioned so that the fluorescence emitted from the mouth portion 14 directly enters the camera 36. According to the above configuration, the inspection device 31 can more easily obtain a clear captured image than when, for example, the fluorescence emitted from the inner surface 16 is reflected by a mirror and then enters the camera 36.

[0066] (3) The camera 36 is positioned so that the optical axis G1 of the camera 36 is inclined with respect to the axis A1 extending through the center of the mouth portion 14. According to the above configuration, the camera 36 captures an image of the container 11 while looking into the inner surface 16. This makes it easier for the inspection device 31 to obtain an image that captures the inner surface 16.

[0067] (4) The multiple cameras 36 are positioned so as to surround the axis A1 extending through the center of the mouth portion 14. According to the above configuration, the multiple cameras 36 increase the imaging range of the inner surface 16. This increases the range over which scratches 26 on the outer surface 15 can be identified.

[0068] (5) The inspection circuit 38 extracts the inspection area 41 from the captured image. The inspection circuit 38 identifies the protrusion area 42 and the outer peripheral surface area 43 in the inspection area 41. The inspection circuit 38 determines the presence or absence of scratches 26 in each of the protrusion area 42 and the outer peripheral surface area 43 based on a threshold value determined for each identified area. The protrusion area 42 tends to appear brighter than the outer peripheral surface area 43. Therefore, if the inspection circuit 38 determines the presence or absence of scratches 26 using a common threshold value for the protrusion area 42 and the outer peripheral surface area 43, the accuracy of the determination may decrease. According to the above configuration, the inspection circuit 38 determines the presence or absence of scratches 26 in each of the protrusion area 42 and the outer peripheral surface area 43 based on a threshold value determined for each area, thereby improving the accuracy of the determination.

[0069] (6) The inspection circuit 38 identifies the threaded region 44 and the support region 45 in the protrusion region 42. The inspection circuit 38 determines the presence or absence of scratches 26 in each of the outer circumferential surface region 43, the threaded region 44, and the support region 45 based on a threshold value determined for each identified region. The container 11 may be fitted with a lid 12 to close the mouth portion 14. Therefore, the mouth portion 14 may have a threaded portion 22 and a support portion 25. The threaded region 44 and the support region 45 tend to have different amounts of light. Therefore, with the above configuration, the inspection circuit 38 determines the presence or absence of scratches 26 in each of the outer circumferential surface region 43, the threaded region 44, and the support region 45 based on a threshold value determined for each region, thereby improving the accuracy of the determination.

[0070] (7) The inspection circuit 38 distinguishes between the tip region 46 and the extension region 47 in the thread region 44. The inspection circuit 38 determines the presence or absence of scratches 26 in each of the outer circumferential surface region 43, the tip region 46, the extension region 47, and the support region 45 based on a threshold value determined for each distinguished region. The tip region 46 tends to appear brighter than the extension region 47. Therefore, with the above configuration, the inspection circuit 38 determines the presence or absence of scratches 26 in each of the outer circumferential surface region 43, the tip region 46, the extension region 47, and the support region 45 based on a threshold value determined for each region, thereby improving the accuracy of the determination.

[0071] 13 and 14, the imaging unit 35 may have a plurality of plane mirrors 51. In this modification, the imaging unit 35 has six plane mirrors 51. The six plane mirrors 51 are positioned so as to surround the container 11 when viewed from the axis A1. The six plane mirrors 51 are positioned symmetrically about the axis A1. The six plane mirrors 51 are positioned at 60-degree intervals about the axis A1.

[0072] The plane mirror 51 is positioned so as to reflect fluorescence emitted from the inner surface 16 toward the camera 36. The six plane mirrors 51 are positioned so that the cameras 36 can image the inner surface 16 from multiple directions. In this modified example, the imaging unit 35 positions one camera 36 on the axis A1. That is, the camera 36 is positioned directly above the container 11 positioned at the inspection position P1. The optical filter 37 is positioned between the container 11 positioned at the inspection position P1 and the camera 36. The plane mirror 51 increases the imaging range of the camera 36 with respect to the inner surface 16. Furthermore, the plane mirror 51 improves the degree of freedom in the position of the camera 36.

[0073] 15 and 16 , the imaging unit 35 may include a curved mirror 52. The curved mirror 52 has a cylindrical shape. The curved mirror 52 is positioned so as to surround the container 11 when viewed from the axis A1.

[0074] The curved mirror 52 is positioned so as to reflect fluorescence emitted from the inner surface 16 toward the camera 36. The curved mirror 52 is positioned so that the camera 36 can capture images of the entire circumference of the inner surface 16. In this modified example, the imaging unit 35 has one camera 36 on the axis A1. The camera 36 and the optical filter 37 are positioned similarly to the modified examples shown in Figures 13 and 14. The curved mirror 52 increases the imaging range of the camera 36 relative to the inner surface 16. Furthermore, the curved mirror 52 improves the degree of freedom in the position of the camera 36.

[0075] 11...container, 14...mouth portion, 18...opening, 31...inspection device, 34...light source, 35...imaging unit, 36...camera, 37...optical filter, 38...inspection circuit

Claims

1. A flaw inspection device for inspecting containers having a mouth portion with an opening formed therein, comprising: a light source that irradiates the container with ultraviolet light; an imaging unit that images the container using fluorescence emitted from the container in response to the ultraviolet light; and an inspection circuit that inspects the container based on the image captured by the imaging unit, wherein the imaging unit has an optical filter that blocks ultraviolet light; and a camera that images the container through the optical filter, and the camera is positioned so as to receive the fluorescence emitted from the mouth portion through the opening.

2. The flaw inspection device according to claim 1, wherein the camera is positioned so that the fluorescent light emitted from the mouth portion directly enters the camera.

3. A flaw inspection device according to claim 1, wherein the camera is positioned so that the optical axis of the camera is inclined with respect to an axis extending through the center of the mouth portion.

4. A flaw inspection device as described in claim 1, comprising a plurality of cameras, said camera being one of said plurality of cameras, said plurality of cameras being positioned so as to surround an axis extending through the center of said mouth portion.

5. A flaw inspection device as claimed in any one of claims 1 to 4, wherein the mouth portion has a cylindrical portion having an outer peripheral surface and a protrusion portion extending along the outer peripheral surface, the cylindrical portion having an edge forming an opening, and the inspection circuit performs the following operations: extracting an inspection area which is an area surrounded by the edge from the captured image; identifying protrusion areas which indicate the protrusion portions and outer peripheral surface areas which indicate areas other than the protrusion portions in the inspection area; and determining the presence or absence of flaws in each of the protrusion areas and the outer peripheral surface areas based on a threshold value determined for each identified area.

6. A flaw inspection device as described in claim 5, wherein the protrusion portion has a threaded portion for attaching a lid that closes the mouth portion, and a support portion that supports the lid, and the inspection circuit performs the following operations: identifying a threaded region that indicates the threaded portion and a support region that indicates the support portion in the protrusion region; and determining the presence or absence of flaws in each of the outer surface region, the threaded region, and the support region based on a threshold value determined for each identified region.

7. The flaw inspection device of claim 6, wherein the inspection circuit: identifies a tip region indicating the tip of the threaded portion and an extension region indicating the portion of the threaded portion other than the tip in the threaded region; and determines the presence or absence of flaws in each of the outer circumferential surface region, the tip region, the extension region, and the support region based on a threshold value determined for each identified region.

Images