Imaging device for article and inspection device for article

Abstract

To provide an imaging device for an article and an inspection device for an article, capable of enhancing identification accuracy of an inspection target area of an article.SOLUTION: An imaging device 11 includes: a first light source 21 for irradiating a container 99 with light of a first wavelength region; a second light source 22 for irradiating the container 99 with light of a second wavelength region; a camera 23; and an optical filter 24 arranged on an optical path between the camera 23 and the container 99. Fluorescence emitted from the container 99 excited by the light of the first wavelength region includes visible light of a third wavelength region. The optical filter 24 has an optical characteristic of transmitting the light of the second wavelength region and the visible light of the third wavelength region. The camera 23 images a first image Img by the visible light of the third wavelength region capable of identifying an inspection target area of the container 99 and the light of the second wavelength region capable of inspecting the inspection target area of the container 99 as an image of the container 99 by the light transmitted through the optical filter 24.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to an object imaging device and an object inspection device. [Background technology]

[0002] For example, Patent Document 1 discloses an imaging device for capturing an image of a light-transmitting object. This imaging device includes multiple cameras that can capture an image of the entire outer periphery of the object. The object is inspected based on the images captured by the multiple cameras. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-157121 Summary of the Invention [Problem to be solved by the invention]

[0004] However, with such imaging devices, depending on the shape of the object, it can be difficult for the inspector to identify the object's desired inspection area. In particular, when there is not a large difference in brightness between the image in the object's inspection area and the image outside the object's inspection area, it becomes difficult to identify the object's inspection area. Thus, there is a need to improve the accuracy of identifying the object's inspection area. [Means for solving the problem]

[0005] The means for solving the above problems and their effects will be described below. The object imaging device that solves the above problem is an object imaging device that images a transparent object having a transparent portion through which light can pass, and includes: a first light source that irradiates the object with light in a first wavelength range; a second light source that irradiates the transparent portion of the object with light in a second wavelength range; a camera that images the object at a position where light from the second light source that has passed through the transparent portion can be incident; and an optical filter that is arranged on an optical path between the camera and the object, wherein the light in the first wavelength range includes ultraviolet light, and the object excited by the light in the first wavelength range is imaged. The fluorescence emitted by the article includes visible light in a third wavelength range, the second wavelength range being longer than the first wavelength range and the third wavelength range, the optical filter having optical properties of blocking light in the first wavelength range and transmitting light in the second wavelength range and visible light in the third wavelength range, and the camera capturing a first image of the article using light transmitted through the optical filter, the first image being made up of visible light in the third wavelength range with which an inspection target area of ​​the article can be identified and light in the second wavelength range with which the inspection target area of ​​the article can be inspected.

[0006] According to this configuration, a first image can be captured by the camera using visible light in the third wavelength range as fluorescence excited by irradiating the object with light in the first wavelength range from the first light source and light in the second wavelength range from the second light source. In particular, when the thickness of the object differs between the inspection target area and the area outside the inspection target area, the inspection target area can be identified by varying the brightness of the visible light in the third wavelength range excited from the object, and the inspection target area can be inspected based on the light in the second wavelength range. Therefore, the accuracy of identifying the inspection target area of ​​the object can be improved.

[0007] In the imaging device, the second wavelength range may include a wavelength range of near-infrared light, and the third wavelength range may include a wavelength range of blue light. According to this configuration, the inspection target area can be identified based on the blue light, and the inspection target area can be inspected based on the near-infrared light, thereby improving the accuracy of identifying the inspection target area of ​​the article.

[0008] In the above-mentioned imaging device, the object may be a container having a threaded portion with a mouth at its end surface and a cylindrical neck extending along an axis, with a thread formed on the threaded portion, and a body portion formed on the opposite side of the neck from the end surface, the second light source irradiates the neck with light in the second wavelength range from a direction tilted at a predetermined angle from the axis, the optical filter is positioned on the optical path between the camera and the neck, and the camera may capture the first image including an image of the neck from the end surface side.

[0009] According to this configuration, the camera captures a first image in which the brightness of the visible light in the third wavelength range excited at the mouth portion is different from the brightness of the visible light in the third wavelength range excited at the thread portion. This makes it possible to obtain a first image in which the mouth portion and the thread portion can be easily distinguished. Therefore, the accuracy of identifying the inspection target area of ​​the article can be improved.

[0010] In the above-described imaging device, the second light source may include two light sources that irradiate the neck portion with light in the second wavelength range from directions tilted at different angles from the axis, and the second light sources may be configured such that one light source emits light at a first timing while the other light source is turned off, and one light source emits light at a second timing while the other light source is turned off, and the camera may capture one of the first images at the first timing and capture the other of the first images at the second timing.

[0011] According to this configuration, two light sources are used as the second light source, and light in the second wavelength range can be emitted from directions tilted at different angles from the axis. By causing the two light sources to emit light at different times, it is possible to capture a first image appropriate for the incidence conditions of the light in the second wavelength range from each of the two light sources. Therefore, it is possible to improve the accuracy of identifying the inspection target area of ​​the article.

[0012] In the above imaging device, the camera may include two cameras that capture images of the neck from different angles on the end face side, and one of the cameras may capture one of the first images, and the other of the cameras may capture the other of the first images.

[0013] This configuration allows the two cameras to capture images of the neck from different angles. This allows the first image to be captured appropriately depending on the incidence conditions of light in the second wavelength range and visible light in the third wavelength range on the two cameras. This improves the accuracy of identifying the inspection target area of ​​the article.

[0014] The above-mentioned inspection device comprises the imaging device and an inspection processing unit that inspects the item based on an image obtained by the imaging device capturing an image of the item, and the inspection processing unit identifies an inspection target area of ​​the item based on a first image captured by visible light in the third wavelength range, and inspects the inspection target area of ​​the item based on a second image captured by light in the second wavelength range.

[0015] According to this configuration, the inspection processing unit inspects the item based on the image obtained by the imaging device, and therefore, by improving the accuracy of identifying the inspection target area of ​​the item, it is possible to improve the inspection accuracy of the inspection target area of ​​the item. [Effects of the Invention]

[0016] According to the present invention, it is possible to improve the accuracy of identifying an inspection target area of ​​an article. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is a block diagram showing an inspection device according to the first embodiment. [Figure 2] FIG. 2(a) is a side view of the article in the first embodiment, and FIG. 2(b) is a plan view of the article in the first embodiment. [Figure 3] FIG. 3 is a schematic plan view showing the imaging device according to the first embodiment. [Figure 4]FIG. 4 is a schematic side view showing the imaging device according to the first embodiment. [Figure 5] FIG. 5 is a diagram showing the configuration of a camera according to the first embodiment, and a graph showing the relationship between the wavelength of light received and the relative sensitivity of the image sensor according to the first embodiment. [Figure 6] FIG. 6 is a graph showing the fluorescence spectral characteristics of polyethylene terephthalate in the first embodiment. [Figure 7] FIG. 7 is a graph showing the emission spectrum of the light source and the emission spectrum of the fluorescent light in terms of the relationship between wavelength and output power. [Figure 8] FIG. 8 is a graph showing the light transmittance characteristics of the optical filter according to the first embodiment. [Figure 9] FIG. 9 is a graph showing the sensitivity characteristics of the camera in the first embodiment as a relationship between wavelength and relative output. [Figure 10] FIG. 10 is a schematic diagram showing the control content in the first embodiment. [Figure 11] 11(a) to 11(f) are diagrams showing captured images of the mouth end face of a container in the example. [Figure 12] FIG. 12 is a graph showing the sensitivity characteristics of the camera after correction in the second embodiment as a relationship between wavelength and relative output. [Figure 13] FIG. 13 is a schematic side view showing an imaging device according to the third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0018] [First embodiment] Below, we will explain the article imaging device and article inspection device. Hereinafter, the article imaging device will be simply referred to as the imaging device. The article inspection device will be simply referred to as the inspection device. Furthermore, red may be referred to as R, green as G, and blue as B.

[0019] <Basic Configuration of Inspection Device 10 and Imaging Device 11> 1, the inspection device 10 is configured to inspect an article, which is an example of an inspection target, by capturing an image of the article. More specifically, the inspection device 10 is configured to inspect a transparent article.

[0020] The inspection device 10 includes an imaging device 11 and an inspection processing unit 15. The inspection device 10 may also include a display unit 16. The imaging device 11 is configured to capture an image of an article, which is an example of a subject. More specifically, the imaging device 11 is configured to capture an image of a transparent article.

[0021] The imaging device 11 includes a control processing unit 12, a transport unit 20, a first light source 21, a second light source 22, a camera 23, and an optical filter 24. The transport unit 20, the first light source 21, the second light source 22, and the camera 23 are controlled by the control processing unit 12.

[0022] The transport unit 20 is configured to transport articles. The transport unit 20 includes a conveyor 20a, a transport drive unit 20b, and an article detection unit 20c. The conveyor 20a is configured to transport articles. The transport drive unit 20b is a drive source for driving the conveyor 20a to transport articles. The article detection unit 20c is a sensor that detects articles transported to the imaging position SP.

[0023] The first light source 21 is configured to irradiate the article with light in a first wavelength range. In particular, the first light source 21 is configured to irradiate a transparent portion of the article with light in the first wavelength range. The first wavelength range includes the wavelength range of ultraviolet light UV.

[0024] The second light source 22 is configured to irradiate the article with light in a second wavelength range. In particular, the second light source 22 is configured to irradiate a transparent portion of the article with light in the second wavelength range. The second wavelength range includes the wavelength range of near-infrared light NI. The second wavelength range is longer than the first wavelength range. The second light source 22 includes multiple light sources 22a and 22b. The second light source 22 includes two light sources 22a and 22b, but may include three or more light sources.

[0025] The camera 23 is configured to capture an image of an article. In particular, the camera 23 is configured to capture an image of a transparent portion of the article. The camera 23 is configured to capture an image of the article through an optical filter 24, which will be described in detail later. The camera 23 outputs an image signal S to the control processing unit 12 as a result of capturing an image of the article. The camera 23 is a color camera.

[0026] The control processing unit 12 is configured with one or more computers. The control processing unit 12 is configured to control the imaging device 11. The control processing unit 12 includes a control unit 13 and a signal processing unit .

[0027] The control unit 13 is configured to control the transport unit 20, the first light source 21, the second light source 22, and the camera 23. The control unit 13 controls the transport unit 20 to transport an article. The control unit 13 controls the first light source 21, the second light source 22, and the camera 23 based on a detection signal from the article detection unit 20c.

[0028] The signal processing unit 14 is configured to process the imaging signal S output by the camera 23. The signal processing unit 14 performs signal processing on the imaging signal S. As a result of the signal processing, the signal processing unit 14 generates an image signal IS including the first image Img. The signal processing unit 14 outputs the generated image signal IS to the inspection processing unit 15.

[0029] The inspection processing unit 15 is composed of one or more computers. The inspection processing unit 15 is configured to inspect an item based on an image obtained by the imaging device 11 capturing an image of the item. Specifically, the inspection processing unit 15 is configured to inspect the quality of the item based on the image capturing results captured by the imaging device 11. The display unit 16 is configured to display an image. Specifically, the display unit 16 is configured to display the inspection results by the inspection processing unit 15.

[0030] <Item composition> Here, the configuration of the article will be described with reference to FIG. 2(a) and 2(b), the article has a transparent portion through which light can pass. The article may be a transparent container 99. The container 99 may be entirely transparent, or may be partially transparent.

[0031] The container 99 is made of, for example, a resin material, but is not limited to, a resin material. Specifically, the container 99 is, for example, a so-called PET bottle, whose resin material is primarily made of polyethylene terephthalate (PET), but is not limited to this. Hereinafter, polyethylene terephthalate may be referred to as PET.

[0032] The resin material of the container 99 may be other known resin materials such as polystyrene (PS), polypropylene (PP), perfluoroalkoxyalkane (PFA), acrylic (MA), polycarbonate (PC), polyvinyl chloride (PVC), etc. The container 99 may be made of an inorganic material such as glass (amorphous material) or a crystalline material.

[0033] The container 99 includes a body 99a, a neck 99b, and a threaded portion 99c. The body 99a extends along the axis of the container 99. The body 99a is cylindrical and has a bottom. The body 99a includes a bottom 99e. The body 99a is formed on the opposite side of the neck 99b from the end face.

[0034] Hereinafter, the axis of the container 99 may be simply referred to as the axis. The direction along the axis is referred to as the axial direction, and the direction intersecting the axial direction is referred to as the radial direction. The image is taken with the container 99 in an upright position. Therefore, the axial direction is the direction along the vertical direction, and the radial direction is the direction along the horizontal direction.

[0035] The neck 99b has a cylindrical shape. The neck 99b is formed above the body 99a. The diameter of the neck 99b is smaller than the diameter of the body 99a, but is not limited to this. The neck 99b extends along the axis.

[0036] The threaded portion 99c is a portion where a screw is formed. The threaded portion 99c is formed on the outer peripheral surface of the upper portion of the neck portion 99b. The threaded portion 99c is formed to protrude in the radial direction. The threaded portion 99c is configured so that a cap (not shown) can be screwed onto it.

[0037] The neck portion 99b has a mouth portion 99d. The mouth portion 99d is formed on an end surface of the neck portion 99b. That is, the neck portion 99b has the mouth portion 99d on its end surface. The mouth portion 99d is ring-shaped.

[0038] In the container 99, the neck portion 99b is a portion that is relatively thick in the axial direction. In particular, the neck portion 99b is a portion that is thicker in the axial direction than the threaded portion 99c. The neck portion 99b has a relatively high proportion of foreign matter and voids mixed in the resin material. This portion is an important target area for inspection, but is also difficult to inspect using images because the brightness tends to be relatively dark due to its large thickness.

[0039] In addition, in the axial direction, the mouth portion 99d is located on the end face of the neck portion 99b, while the thread portion 99c is located closer to the body portion 99a than the end face of the neck 99b. Thus, when the first image Img is captured from the end face side of the neck 99b in the axial direction, it is difficult to distinguish between the area corresponding to the thread portion 99c and the area corresponding to the mouth portion 99d. In other words, when inspecting an article with the mouth portion 99d as the inspection target area, it is difficult to distinguish between the areas of the thread portion 99c and the mouth portion 99d.

[0040] The container 99 is divided into a plurality of regions in the radial direction. More specifically, the container 99 is divided into four regions in the radial direction: a first region R1, a second region R2, a third region R3, and a fourth region R4. Each of the regions R1 to R4 is divided into four regions, with 360° divided into four regions, and the four regions are divided every 90°. The first region R1 and the third region R3 are regions separated by the center of the container 99 in the radial direction. The second region R2 and the fourth region R4 are regions separated by the center of the container 99.

[0041] <Detailed configuration of the imaging device 11> Next, the detailed configuration of the imaging device 11 will be described with reference to FIGS. As shown in Figure 3, the conveyor 20a is configured to convey articles in a conveying direction MD. The conveyor 20a conveys multiple articles in the conveying direction MD with regular or irregular intervals between them. The conveyor 20a conveys the articles along a path that passes through the imaging position SP.

[0042] The conveyor 20a may be, for example, a belt conveyor, a roller conveyor, or the like. The conveyor 20a may be one that grasps and transports an article, or one that transports an article in a suspended state. Note that the transport unit 20 may not be equipped with the conveyor 20a, but may instead be equipped with a robot that places the articles one by one at the imaging position SP. The articles may be placed at the imaging position SP by an operator.

[0043] As shown in FIGS. 3 and 4, the first light source 21 is located on the optical path between the camera 23 and the article. The first light source 21 includes a window portion 21a and a light-emitting portion 21b. The window portion 21a is located in the center of the first light source 21. The window portion 21a has a hole shape, but is not limited to this and may be formed, for example, from a transparent resin having translucency. The light-emitting portion 21b is capable of emitting light from the periphery of the window portion 21a toward the center. The light-emitting portion 21b may be an LED.

[0044] When the article is irradiated with ultraviolet light UV from the first light source 21, it is excited to emit fluorescence FR. The fluorescence FR is light in a third wavelength range. The light in the third wavelength range includes visible light. In particular, the light in the third wavelength range includes visible light in the wavelength range of blue light. Thus, the third wavelength range includes fluorescence excited from the article by irradiating the article with light in the first wavelength range. The third wavelength range is longer than the first wavelength range and shorter than the second wavelength range.

[0045] 3, one light source 22a of the second light sources 22 is located closer to the conveying direction MD than the imaging position SP. The light source 22a is provided at a position where its optical axis is inclined at a first angle θ1 with respect to the direction along the conveying direction MD in the horizontal direction. The first angle θ1 is 45°, but is not limited to this. The light source 22a is disposed so that its optical axis is located in the first region R1 and the third region R3.

[0046] The other light source 22b of the second light sources 22 is located on the opposite side of the conveying direction MD from the imaging position SP. The other light source 22b is provided at a position where its optical axis is inclined by a first angle θ1 with respect to the direction along the conveying direction MD in the horizontal direction. The other light source 22b is disposed so that its optical axis is located in the second region R2 and the fourth region R4.

[0047] 4, the second light source 22 is located closer to the body 99a than the neck 99b in the axial direction Z. The second light source 22 is provided at a position where its optical axis is inclined by a second angle θ2 with respect to the axial direction Z. The second angle θ2 is 45°, but is not limited to this and may be any angle, such as an angle greater than 0° and equal to or less than 90°.

[0048] In this way, the second light source 22 irradiates the neck portion 99b with light in the second wavelength range from a direction tilted at a predetermined angle from the axial direction Z. In particular, the light sources 22a and 22b irradiate the neck portion 99b with light in the second wavelength range from directions tilted at different angles from the axial direction Z. Furthermore, the light sources 22a and 22b themselves irradiate the neck portion 99b with light in the second wavelength range from angles different from each other.

[0049] Camera 23 captures an image of the article at a position where light from second light source 22 that has passed through a transparent portion of the article can be incident. Camera 23 is disposed on the end face side of neck portion 99b along the axis of the article. As a result, camera 23 captures a first image Img including an image of neck portion 99b from the end face side. Camera 23 is positioned on the optical path between camera 23 and the article, sandwiching an optical filter 24 (described later).

[0050] The optical filter 24 is disposed on the optical path between the camera 23 and the article. Specifically, the optical filter 24 is disposed on the optical path between the camera 23 and the neck portion 99b. The optical filter 24 has the optical property of blocking light in a first wavelength range. The optical filter 24 has the optical property of transmitting light in a second wavelength range. The optical filter 24 has the optical property of transmitting light in a third wavelength range.

[0051] In this way, the camera 23 captures the first image Img as an image of the article using light transmitted through the optical filter 24. That is, the first image Img is a transmission image of the article using blue light included in the visible light in the third wavelength range and near-infrared light NI in the second wavelength range.

[0052] <Configuration of Camera 23> Next, the configuration and imaging characteristics of the camera 23 will be described with reference to FIG. 5, the camera 23 is based on, for example, a general-purpose camera that captures RGB color images. The camera 23 of this embodiment is configured by removing the near-infrared light cut filter 98 from the general-purpose camera. The near-infrared light cut filter 98 blocks near-infrared light NI.

[0053] The camera 23 is not limited to a configuration based on a general-purpose color camera. For example, it may be a dedicated camera manufactured specifically for this purpose, as long as it has RGB imaging characteristics that can receive near-infrared light NI and has sensitivity equal to or greater than a predetermined value in the wavelength band of near-infrared light NI.

[0054] The camera 23 includes a lens barrel 30, a lens 31, and an image sensor 32. The lens 31 is attached to the lens barrel 30. The image sensor 32 captures an image of light that has passed through the lens 31.

[0055] The image sensor 32 includes an R light receiving element 32R, a G light receiving element 32G, and a B light receiving element 32B. In the image sensor 32, the R light receiving element 32R, the G light receiving element 32G, and the B light receiving element 32B are arranged in a predetermined array. The image sensor 32 includes a color filter 33. The color filter 33 includes an R filter 33R, a G filter 33G, and a B filter 33B.

[0056] The R light receiving element 32R receives red light that has passed through the R filter 33R. The R light receiving element 32R outputs an R imaging signal that corresponds to the amount of red light received. The G light receiving element 32G receives green light that has passed through the G filter 33G. The G light receiving element 32G outputs a G imaging signal that corresponds to the amount of green light received. The B light receiving element 32B receives blue light that has passed through the B filter 33B. The B light receiving element 32B outputs a B imaging signal that corresponds to the amount of blue light received.

[0057] As shown in graph 40, the R light receiving element 32R, the G light receiving element 32G, and the B light receiving element 32B are sensitive to light in their respective wavelength bands. In this embodiment, by using a camera 23 in which the near-infrared light cut filter 98 has been removed from a general-purpose camera, the image sensor 32 has RGB imaging characteristics with sensitivity equal to or greater than a predetermined value in the wavelength band of near-infrared light NI. In other words, the R light receiving element 32R, the G light receiving element 32G, and the B light receiving element 32B are sensitive to light in the visible wavelength region VA and the near-infrared wavelength region NIRA.

[0058] The light receiving elements 32R, 32G, and 32B receive the light that has passed through the filters 33R, 33G, and 33B according to their respective sensitivities, out of the light that has passed through the optical filter 24. The image sensor 32 outputs an imaging signal S in which imaging signals having R values, G values, and B values ​​corresponding to the amount of light received by the R light receiving element 32R, G light receiving element 32G, and B light receiving element 32B, respectively, are arranged serially in a predetermined order.

[0059] In this way, camera 23 captures a first image Img formed by incident light that has passed through an object and passes through optical filter 24 and is then focused on image sensor 32 through lens 31. In particular, optical filter 24 blocks ultraviolet light UV from camera 23. Therefore, camera 23 captures a first image Img formed by incident light that includes near-infrared light NI and fluorescent light FR and is focused on image sensor 32 through lens 31. Camera 23 outputs an imaging signal S that includes the first image Img captured by image sensor 32.

[0060] The color filter 33 may be a complementary color filter of Mg, Ye, or Cy instead of the primary color filter of RGB. In addition to the primary color filter or the complementary color filter, a near-infrared light cut filter that selectively transmits near-infrared light NI may be mixed. Furthermore, the primary color filter may be R, G1, G2, or B filters, and the color filter 33 may be a combination of a complementary color filter and a primary color filter. Furthermore, three or more types of filters may be combined.

[0061] <Fluorescence spectroscopic characteristics of the product> 6, when the resin material of an article is PET, the article has fluorescence spectroscopic characteristics as shown in graph 41. The vertical axis of graph 41 represents the excitation wavelength (nm) incident on the resin material, and the horizontal axis of graph 41 represents the fluorescence wavelength (nm) of the fluorescence FR emitted by the resin material.

[0062] In graph 41, line UL indicates the line where the excitation wavelength and the fluorescence wavelength are the same value. In other words, line UL indicates the line where no fluorescence FR is generated. In graph 41, fluorescence distribution FD indicates the distribution of wavelengths of fluorescence FR emitted due to excitation at the molecular level of the resin material when ultraviolet light UV is incident.

[0063] The fluorescence distribution FD indicates the distribution in which fluorescence FR with a longer wavelength than the incident light is generated. The fluorescence distribution FD exists to the right of the line UL (on the longer wavelength side). In this way, when ultraviolet light UV is incident on a resin material, fluorescence FR is generated in a wavelength range that includes the wavelengths of visible light.

[0064] Specifically, PET emits fluorescent light FR containing blue light when exposed to ultraviolet light UV. The wavelength range of blue light is approximately 400 to 500 nm. When ultraviolet light UV is applied to a resin material, the resin material itself emits visible light with a shorter wavelength, such as blue light. In this embodiment, unlike light transmission or reflection from an article, the fluorescent light FR emitted by the article material itself is used to acquire an image suitable for a specific process, such as inspection.

[0065] Although an example in which the resin material is PET has been shown, a configuration in which ultraviolet light UV of a wavelength determined by the fluorescent spectroscopic characteristics of the resin material that constitutes the article is irradiated onto the article can also be adopted for articles made of other resin materials.

[0066] In this way, the wavelength of the ultraviolet light UV emitted by the first light source 21 is selected as an excitation wavelength that can emit fluorescence FR indicated by a fluorescence distribution FD specified from the fluorescence spectral characteristics of the resin material that constitutes the article to be imaged.

[0067] <Emission spectrum of light source, etc.> 7, graph 42 shows the combined emission spectrum of ultraviolet light UV from first light source 21 and near-infrared light NI from second light source 22. In graph 42, the emission spectrum LS2 of near-infrared light NI irradiated from second light source 22 has an output power of 0.1 or more in the range of approximately 800 to 880 nm.

[0068] In graph 42, the emission spectrum LS1 of the ultraviolet light UV irradiated from first light source 21 has an output power of 0.1 or more in the range of approximately 350 to 390 nm. The peak of the emission spectrum LS1 is approximately 365 nm. This wavelength of approximately 365 nm is a value at which fluorescence FR of a predetermined intensity or more can be emitted, as determined from the fluorescence spectral characteristics of PET shown in FIG. 6. Therefore, when ultraviolet light UV with the emission spectrum LS1 is irradiated onto a PET article, the article itself emits fluorescence FR with a wavelength of approximately 400 to 500 nm, as shown in FIG. 7, resulting in a fluorescence spectrum FL. The fluorescence spectrum FL is in the blue light wavelength range, which is the wavelength range of blue light.

[0069] <Spectral transmittance characteristics of optical filter 24> 8, an example of the optical characteristics of optical filter 24 is a spectral transmittance characteristic having a blocking region in the ultraviolet wavelength region UVA and a transmission region in the blue light wavelength region and the near-infrared wavelength region NIRA within the visible light wavelength region VA. In particular, graph 43 shows that optical filter 24 also has a blocking region in a wavelength region other than the blue light wavelength region in the visible light wavelength region VA. Therefore, optical filter 24 blocks ultraviolet light UV and visible light other than the blue light wavelength region, while allowing the transmission of fluorescence FR in the blue light wavelength region and near-infrared light NI.

[0070] FIG. 9 shows the sensitivity characteristics of camera 23 via optical filter 24. That is, graph 44 shows the sensitivity characteristics of image sensor 32 constituting camera 23. In graph 44, R light receiving element 32R has a relative output close to 0 in the visible light wavelength range VA, and a relative output of 0.2 or more in the range of approximately 780 to 960 nm included in the near-infrared wavelength range NIRA. G light receiving element 32G has a relative output of 0.2 or more in the near-infrared wavelength range NIRA.

[0071] The B light receiving element 32B has a relative output of 0.2 or more in the range of approximately 400 to 540 nm included in the visible light wavelength range VA, and a relative output of 0.2 or more in the range of approximately 780 to 960 nm included in the near-infrared wavelength range NIRA. In other words, the B light receiving element 32B is sensitive to the wavelength range of blue light and the wavelength range of near-infrared light NI. As shown in FIGS. 6 and 7, the fluorescence FR has a wavelength in the wavelength range of blue light. Therefore, the B light receiving element 32B is sensitive to the wavelength range of the fluorescence FR.

[0072] <Control processing unit 12> As shown in FIG. 10, the control unit 13 causes the first light source 21 to emit light, and causes multiple light sources 22a, 22b of the second light source 22 to emit light at different emission timings. Specifically, in a first period, the control unit 13 causes one light source 22a to emit light and the other light source 22b not to emit light. In a second period, the control unit 13 does not cause one light source 22a to emit light and causes the other light source 22b to emit light. The first period and the second period are different periods. The first period is a period that includes the first timing. The second period is a period that includes the second timing.

[0073] In this way, the control unit 13 controls the light sources 22a so that when one of the light sources 22a emits light at the first timing, the other light source 22b is turned off, and when one of the light sources 22a is turned off at the second timing, the other light source 22b is turned on.

[0074] The control unit 13 causes the camera 23 to capture a first image Img in the first period and the second period. As a result, the control unit 13 causes the camera 23 to capture a first frame as the first image Img with one light source 22a emitting light in the first period. The control unit 13 causes the camera 23 to capture a second frame as the first image Img with the other light source 22b emitting light in the second period.

[0075] In this way, the control unit 13 controls the camera 23 to capture one first image Img with one light source 22a emitting light at a first timing, and to capture the other first image Img with the other light source 22b emitting light at a second timing.

[0076] When the signal processing unit 14 is configured to receive an RGB color image signal S from the camera 23, it divides the image signal S into an R image signal, a G image signal, and a B image signal, each of which is one band. The signal processing unit 14 may perform brightness adjustment using nonlinear processing such as normalization and gamma correction, and edge enhancement processing on the image signal S as needed. The signal processing unit 14 outputs image signals IS each including an RGB color image, an R image, a G image, and a B image to the inspection processing unit 15. The signal processing unit 14 may output an image signal IS including a B image and an R image for inspection to the inspection processing unit 15, or may output an image signal IS including an RGB color image for inspection to the inspection processing unit 15.

[0077] <Inspection processing unit 15> The inspection processing unit 15 inspects the quality of the article based on the image signal IS input from the signal processing unit 14. In particular, the inspection processing unit 15 inspects the quality of the mouth portion 99d as viewed from the end face side of the neck portion 99b, for example. The inspection processing unit 15 displays the inspection results on the display unit 16.

[0078] The inspection processing unit 15 inspects the item based on the image signal IS including the B image and the R image. In this case, the inspection processing unit 15 inspects the item based on the image signal IS including the B image including fluorescence FR in the wavelength range of blue light and near-infrared light NI, and the R image including near-infrared light NI.

[0079] The fluorescence FR in the blue light wavelength range becomes brighter as the thickness in the axial direction increases. Therefore, the fluorescence FR in the blue light wavelength range becomes brighter at the mouth portion 99d, which has a thicker axial direction, than at the thread portion 99c, which has a thinner axial direction. Therefore, the fluorescence FR in the blue light wavelength range makes it possible to distinguish between the mouth portion 99d, which is the inspection target area, and the thread portion 99c, which is outside the inspection target area.

[0080] The fluorescent light FR in the blue wavelength range can be used to inspect the neck portion 99b, which has a large axial thickness, for defects such as foreign matter or pores mixed in the resin material, while the near-infrared light NI can be used to inspect the mouth portion 99d for defects such as chips or cracks.

[0081] In this way, the inspection processing unit 15 identifies the inspection target area of ​​the item based on the first image formed by visible light in the third wavelength range, and inspects the inspection target area of ​​the item based on the second image formed by light in the second wavelength range.

[0082] In other words, camera 23 captures a first image Img using visible light in the third wavelength range and light in the second wavelength range via optical filter 24. That is, camera 23 captures a first image Img using visible light in the third wavelength range with which an inspection target area of ​​the article can be identified and light in the second wavelength range with which an inspection target area of ​​the article can be inspected, as an image of the article using light that has passed through optical filter 24.

[0083] In particular, the inspection processing unit 15 inspects the second region R2 and the fourth region R4 of the article based on the image signal IS including the first frame of the first image Img. In this way, the inspection processing unit 15 inspects the second region R2 and the fourth region R4 of the article that do not include the optical axis of one light source 22a while one light source 22a is emitting light during the first period.

[0084] The inspection processing unit 15 inspects the first region R1 and the third region R3 of the article based on the image signal IS including the second frame of the first image Img. In this way, the inspection processing unit 15 inspects the first region R1 and the third region R3 of the article that do not include the optical axis of the other light source 22b while the other light source 22b is emitting light during the second period.

[0085] The inspection processing unit 15 may inspect the item based on the image signal IS of an RGB color image. In this case, the inspection processing unit 15 inspects the item based on the image signal IS of an RGB color image including fluorescence FR in the wavelength range of blue light and near-infrared light NI.

[0086] In this way, the inspection processing unit 15 identifies the inspection target area of ​​the article based on the first image Img formed by the visible light in the third wavelength range and the light in the second wavelength range, and then inspects the inspection target area of ​​the article based on the first image Img formed by the visible light in the third wavelength range and the light in the second wavelength range.

[0087] <Operation of the First Embodiment> Next, the operation of the first embodiment will be described. As shown in Fig. 3, an article is conveyed in a conveying direction MD by a conveyor 20a. When an article is detected by the article detection unit 20c shown in Fig. 1, a trigger signal is input to the control unit 13. The control unit 13 that has input the trigger signal controls the first light source 21, the second light source 22, and the camera 23.

[0088] The article is irradiated with ultraviolet light UV from the first light source 21. Some of the ultraviolet light UV is reflected from the surface of the article, and some enters the interior of the article. The ultraviolet light UV incident on the article excites electrons that make up the molecules of the resin material that makes up the article, causing the article to emit fluorescence FR.

[0089] The article is irradiated with near-infrared light NI from the second light sources 22. In particular, in the first period, the near-infrared light NI is irradiated from one light source 22a of the second light sources 22. In the second period, the near-infrared light NI is irradiated from the other light source 22b of the second light sources 22.

[0090] Fluorescent light FR emitted by the article itself is incident on camera 23. If the opening 99d has a defect such as a chip or crack, near-infrared light NI is diffused or refracted at the defect and incident on camera 23. Ultraviolet light UV is blocked by optical filter 24.

[0091] The camera 23 captures a first image Img of the article using near-infrared light NI and fluorescent light FR, viewed from the end surface side. In particular, the camera 23 captures a first frame as the first image Img during a first period in a state in which the article is irradiated with near-infrared light NI from one light source 22a. The camera 23 captures a second frame as the first image Img during a second period in a state in which the article is irradiated with near-infrared light NI from the other light source 22b.

[0092] An imaging signal S captured by the camera 23 is input to the signal processing unit 14. The imaging signal S is subjected to predetermined processing by the signal processing unit 14, thereby generating an RGB color image, an R image, a G image, and a B image. An image signal IS including the generated RGB color image, the R image, the G image, and the B image is output to the inspection processing unit 15.

[0093] The inspection processing unit 15 inspects the item based on the R image and the B image. In particular, the inspection processing unit 15 identifies an inspection target area based on the B image, and inspects the inspection target area based on the R image.

[0094] Furthermore, the inspection of the item is performed based on the RGB color image by the inspection processing unit 15. In particular, the inspection processing unit 15 identifies an inspection target area based on the RGB color image and performs inspection of the inspection target area.

[0095] As shown in FIGS. 11(a) and 11(d), as a result of capturing images using the camera 23, in Image B, the mouth portion 99d has a high brightness and the thread portion 99c has a low brightness. The mouth portion 99d has a large thickness in the axial direction, and the brightness thereof due to the excited fluorescence FR is high. The thread portion 99c has a small thickness in the axial direction, and the brightness thereof due to the excited fluorescence FR is low. Therefore, in the first image Img captured from the axial direction, the mouth portion 99d and the thread portion 99c can be easily distinguished. In other words, in the first image Img captured from the axial direction, the mouth portion 99d, which is the inspection target region, can be distinguished. Furthermore, in Image B, the fluorescence FR excited in the neck portion 99b can be used to detect foreign matter or pores that have entered the neck portion 99b.

[0096] 11(b) and 11(e), if there is a defect such as a chip or crack on the end face side of the mouth portion 99d, the defect can be detected by the diffuse reflection or refraction of the near-infrared light NI in the R image. In particular, defects can be detected by the R image for the mouth portion 99d, which is the inspection target area identified in the B image.

[0097] 11(c) and 11(f), in the RGB color image, the opening 99d has a high brightness and the threaded portion 99c has a low brightness, just like in the B image. In particular, in the RGB color image, the opening 99d shines light blue (white in the figure). This makes it possible to identify the opening 99d, which is the inspection target area, in the first image Img captured from the axial direction.

[0098] In the RGB color image, as with the R image, if there is a defect on the end face side of the mouth portion 99d, the defect can be detected by the diffuse reflection or refraction of near-infrared light NI. Also, in the RGB color image, as with the B image, foreign matter or pores in the neck portion 99b can be detected by the fluorescence FR excited in the neck portion 99b.

[0099] 11(a) to 11(c), in the first frame of the first image Img, the first region R1 and the third region R3 include high-brightness regions, while in the first frame of the first image Img, the second region R2 and the fourth region R4 do not include high-brightness regions.

[0100] In the first frame of the first image Img, the first region R1 and the third region R3 are regions that include the optical axis of one light source 22a. In the first frame of the first image Img, the second region R2 and the fourth region R4 are regions that do not include the optical axis of one light source 22a.

[0101] In this way, the first frame of the first image Img is used to inspect the article in the second region R2 and the fourth region R4 that do not include the optical axis of one light source 22a, while the first frame of the first image Img is not used to inspect the article in the first region R1 and the third region R3 that include the optical axis of one light source 22a.

[0102] 11(d) to 11(f), in the second frame of the first image Img, the second region R2 and the fourth region R4 include high-brightness regions, while in the second frame of the first image Img, the first region R1 and the third region R3 do not include high-brightness regions.

[0103] In the second frame of the first image Img, the second region R2 and the fourth region R4 are regions that include the optical axis of the other light source 22b. In the second frame of the first image Img, the first region R1 and the third region R3 are regions that do not include the optical axis of the other light source 22b.

[0104] In this way, the second frame of the first image Img is used to inspect the article in the first region R1 and the third region R3, which do not include the optical axis of the other light source 22b. The second frame of the first image Img is not used to inspect the article in the second region R2 and the fourth region R4, which include the optical axis of the other light source 22b.

[0105] <Effects of the first embodiment> According to the first embodiment described above in detail, the following effects can be obtained. (1-1) When the first light source 21 irradiates an object with ultraviolet light UV, the excited object emits blue light as fluorescence FR. The camera 23 captures a first image Img of the object using light transmitted through the optical filter 24, consisting of blue light that can identify the inspection target area of ​​the object and near-infrared light NI that can inspect the inspection target area of ​​the object. According to this configuration, the camera 23 captures the first image Img using the blue light contained in the fluorescence FR and near-infrared light NI from the second light source 22. In particular, when the thickness of the object differs between the inspection target area and outside the inspection target area, the inspection target area can be identified by varying the brightness of the blue light excited from the object. This makes it possible to inspect the inspection target area based on the near-infrared light NI. Therefore, the accuracy of identifying the inspection target area of ​​the object can be improved.

[0106] (1-2) Specifically, when the thickness of the object differs between the mouth portion 99d and the thread portion 99c, which are the inspection target areas, the inspection target areas can be identified by varying the brightness of the fluorescence FR excited from the object, and the inspection target areas can be inspected based on the near-infrared light NI. Therefore, the accuracy of identifying the inspection target areas of the object can be improved.

[0107] (1-3) Furthermore, in the past, defects were difficult to find in images captured of light passing through a transparent object when the difference between light and dark was small. In particular, in parts of a transparent object that are thick in the light transmission direction, the amount of light that passes through the object and reaches the camera is relatively small compared to other thinner parts due to light attenuation, absorption, refraction, reflection, etc. For this reason, the brightness of parts of a transparent object that are thick in the imaging direction of the camera tends to be dark, making it difficult to obtain images of a quality suitable for specific processing such as inspection.

[0108] Therefore, the camera 23 captures a first image Img, which is an image of the object using light transmitted through the optical filter 24. With this configuration, even in parts of the object that are thick in the imaging direction, the object emits blue light excited by irradiation with ultraviolet light UV. This makes it possible to obtain an image with small differences in brightness due to differences in the object's thickness in the imaging direction. This therefore improves the accuracy of object inspection.

[0109] (1-4) The second light source 22 includes two light sources 22a and 22b that irradiate the neck portion 99b with near-infrared light NI from directions tilted at different angles from the axis. During a first period, when one light source 22a emits light, the other light source 22b is turned off, and during a second period, when one light source 22a is turned off, the other light source 22b emits light. The camera 23 captures a first frame as one first image Img during the first period and a second frame as the other first image Img during the second period. This configuration allows the two light sources 22a and 22b as the second light source 22 to irradiate near-infrared light NI from directions tilted at different angles from the axis. By causing the two light sources 22a and 22b to emit light at different times, it is possible to capture a first image Img appropriate for the incidence conditions of the near-infrared light NI from each of the two light sources 22a and 22b. Therefore, the accuracy of identifying the inspection target area of ​​the article can be improved.

[0110] (1-5) The inspection processing unit 15 identifies the inspection target area of ​​the item based on the B image captured by blue light, and inspects the inspection target area of ​​the item based on the R image captured by near-infrared light NI. According to this configuration, the inspection processing unit 15 inspects the item based on the image obtained by the imaging device 11. Therefore, by improving the accuracy of identifying the inspection target area of ​​the item, it is possible to improve the inspection accuracy of the inspection target area of ​​the item.

[0111] [Second embodiment] Next, a second embodiment will be described. In the following description, the same configuration as in the already described embodiment will be omitted or simplified, and only the configuration different from the already described embodiment will be described.

[0112] In the second embodiment, the signal processing unit 14 may correct the R image, the G image, and the B image. The signal processing unit 14 may perform a matrix operation based on the R image, the G image, and the B image to generate corrected X image, Y image, and Z image. The signal processing unit 14 outputs the corrected X image, Y image, and Z image to the inspection processing unit 15.

[0113] As shown in FIG. 12, in graph 45, the corrected X image is an image based on the R image. The X image may be an image obtained by amplifying the output of the R image. The Y image is an image based on the G image. The Z image is an image based on the R image and the B image. The Z image may be an image obtained by amplifying the output of the B image, or may be an image obtained by subtracting the R image from the B image. Specifically, the Z image is an image obtained by attenuating the output of the near-infrared wavelength region NIRA from the B image by subtracting the R image from the B image.

[0114] The inspection processing unit 15 detects the inspection target area where the brightness of the fluorescence FR in the visible light wavelength range VA is high based on the Z image in which the relative output in the near-infrared wavelength range NIRA is attenuated, thereby enabling the inspection processing unit 15 to improve the accuracy of identifying the mouth 99d, which is the inspection target area.

[0115] The inspection processing unit 15 inspects the inspection target area based on the presence or absence of an area with high brightness of near-infrared light NI in the near-infrared wavelength region NIRA, based on the inspection target area identified based on the Z image in the X image where the relative output in the near-infrared wavelength region NIRA is high.

[0116] <Effects of the second embodiment> According to the second embodiment described above in detail, the following effects can be obtained. (2-1) The signal processing unit 14 corrects the R image, G image, and B image separated from the RGB color image captured as the first image Img. In particular, the signal processing unit 14 subtracts the R image from the B image to generate a Z image in which the output of the near-infrared wavelength region NIRA is attenuated from the B image. The inspection processing unit 15 identifies the inspection target area based on the Z image. With this configuration, the inspection processing unit 15 can identify the inspection target area based on the Z image captured using blue light. Therefore, the identification accuracy and inspection accuracy of the inspection target area of ​​the item can be improved.

[0117] [Third embodiment] Next, a third embodiment will be described. 13, in the third embodiment, the imaging device 11 may include a plurality of cameras 23. The imaging device 11 includes two cameras 23a and 23b as the plurality of cameras 23, but may include three or more cameras.

[0118] The two cameras 23a, 23b are arranged so as to be inclined in different directions by a third angle θ3 with respect to the axial direction Z. That is, the two cameras 23a, 23b are configured to capture images of the neck portion 99b on the end face side from different angles.

[0119] The control unit 13 controls the one camera 23a and the other camera 23b of the cameras 23 so that they capture the first images Img at the same timing, whereby the one camera 23a of the cameras 23 captures one first image Img, and the other camera 23b of the cameras 23 captures the other first image Img.

[0120] <Effects of the third embodiment> According to the third embodiment described above in detail, the following effects can be obtained. (3-1) The camera 23 includes two cameras 23a and 23b that capture images of the neck portion 99b from different angles on the end face side of the neck portion 99b. One camera 23a captures one first image Img, and the other camera 23b captures the other first image Img. This configuration allows the two cameras 23a and 23b to capture images of the neck portion 99b from different angles. This makes it possible to capture first images Img appropriate for the incidence conditions of the near-infrared light NI and blue light on the two cameras 23a and 23b. This improves the accuracy of identifying the inspection target area of ​​the article.

[0121] [Example of change] This embodiment can be modified as follows: This embodiment and the following modifications can be combined and implemented within the scope of technical compatibility.

[0122] In the third embodiment, the control unit 13 may control the one camera 23a to capture the first image Img with the one light source 22a emitting light during the first period. The control unit 13 may control the other camera 23b to capture the first image Img with the other light source 22b emitting light during the second period.

[0123] In this case, the camera 23a is positioned at a position and angle where the angle of incidence of light from the light source 22a is smaller than those of the camera 23b and the camera 23 of the first embodiment. The camera 23b is positioned at a position and angle where the angle of incidence of light from the light source 22b is smaller than those of the camera 23a and the camera 23 of the first embodiment. This allows the cameras 23a and 23b to capture a first image Img that can identify a defect in the opening 99d, even if the angle of diffuse reflection or refraction of the near-infrared light NI at the defect is small. This improves the inspection accuracy of the inspection target area of ​​the article.

[0124] The second light source 22 may include one light source or three or more light sources. That is, the second light source 22 may include one or more light sources. When the second light source 22 includes M light sources as the multiple light sources, the light sources are preferably arranged so as to be inclined at an angle obtained by dividing 180° by M in the radial direction. As a specific example, when the second light source 22 includes three light sources as the multiple light sources, the three light sources may be arranged so as to be inclined at 60° each in the radial direction.

[0125] In this case, the control unit 13 causes the first light source to emit light in a first period, the second light source to emit light in a second period, and the third light source to emit light in a third period. The camera 23 captures a first frame of the first image Img in the first period, a second frame of the first image Img in the second period, and a third frame of the first image Img in the third period. The inspection processing unit 15 may inspect the item based on the image signal IS including each frame of the first image Img.

[0126] The second light source 22 may be disposed in any position and may illuminate the article from any direction. For example, the second light source 22 may be disposed on the radial side of the container 99 and irradiate the neck portion 99b with near-infrared light NI along the radial direction. For example, the second light source 22 may be disposed on the neck portion 99b side of the container 99 and irradiate the near-infrared light NI toward the neck portion 99b by reflecting it off a mirror. The second wavelength range is not limited to the wavelength range of near-infrared light NI as long as it is a wavelength range longer than the first wavelength range and the third wavelength range, and may be, for example, a wavelength range of visible light that does not include the wavelength range of near-infrared light NI.

[0127] The optical filter 24 may allow the transmission of visible light in wavelength ranges other than the blue light wavelength range in the visible light wavelength range VA, as long as it blocks at least ultraviolet light UV and allows the transmission of fluorescence FR in the blue light wavelength range and near-infrared light NI. In other words, the optical filter 24 may allow the transmission of visible light and near-infrared light NI.

[0128] The camera 23 may be placed in any position and may capture an image of the article from any direction. For example, the camera 23 may capture an image of the article by reflecting, with a mirror, the fluorescence FR excited by the article and the near-infrared light NI transmitted through the article.

[0129] The number of colors of the color filters 33 constituting the image sensor 32 is not limited to three or four, but may be five or six. At least one of the colors may be a filter that does not transmit visible light but transmits near-infrared light NI.

[0130] The arrangement pattern of the color filters 33 that make up the image sensor 32 is not limited to the RGB Bayer arrangement, but may be any other arrangement pattern such as a stripe arrangement. The imaging device 11 does not need to include the conveying unit 20. In this case, the imaging device 11 may be able to communicate with a conveying device that includes the conveying unit 20. The control unit 13 controls the conveyor 20a by communicating with the conveying device, and a trigger signal is input from the item detection unit 20c. For example, the imaging device 11 may be configured such that an operator places an item, which is the subject of the image, at the imaging position SP.

[0131] In addition to the camera 23 that captures an image from the end face side of the neck portion 99b, the inspection device 10 may also include another camera, such as a camera that captures an image of the article from a radial direction. Such a camera may be configured to capture an image of at least one of the body portion 99a and the neck portion 99b from a radial direction. Furthermore, the camera 23 and the other camera may be installed at the same imaging position SP, or may be installed at different imaging positions. The inspection device 10 may inspect the article based on an image captured by the camera 23 and an image captured by the other camera.

[0132] The inspection device 10 may include a discharge device (not shown). The discharge device is configured to remove the articles transported by the conveyor 20a from the conveyor 20a. If the article is a defective product, the control unit 13 may control the discharge device to remove the defective article from the conveyor 20a.

[0133] The inspection target area of ​​the article is not limited to the neck portion 99b, and may be any area. The inspection target area of ​​the article may be an area having a different thickness in the imaging direction compared to the outside of the inspection target area of ​​the adjacent article. The inspection target area of ​​the article may be an area having a greater thickness in the imaging direction compared to the outside of the inspection target area of ​​the adjacent article, or an area having a smaller thickness in the imaging direction.

[0134] The object being photographed is not limited to a PET bottle, as long as it has a transparent or translucent portion. The object may be, for example, a plastic bottle or container made of a resin material other than PET, tableware, cups, flexible packaging, beverages, cases, everyday items, parts, components, or liquid ingredients. Furthermore, the object may be a decorative object, glassware, acrylic product, decorative aquarium, beaker, or a transparent or translucent bag containing a transparent or translucent object. It may also be a food product such as jelly or a processed food product.

[0135] The article is not limited to an empty container, but may be a container containing a liquid or other substance that is transmissive to near-infrared light NI. In this case, the liquid may be translucent or opaque to visible light as long as it is transmissive to near-infrared light NI.

[0136] The imaging device 11 is used for the purpose of acquiring images suitable for inspection, but may also be used to acquire images suitable for predetermined processing other than inspection. For example, the imaging device 11 may be used to acquire images suitable for purposes such as measurement, analysis, evaluation, and expression.

[0137] The image output by the imaging device 11 may be visually inspected by an inspector. [Explanation of symbols]

[0138] 10...inspection device, 11...imaging device, 12...control processing unit, 13...control unit, 14...signal processing unit, 15...inspection processing unit, 16...display unit, 20...transport unit, 20a...conveyor, 20b...transport drive unit, 20c...article detection unit, 21...first light source, 21a...window unit, 21b...light emitting unit, 22...second light source, 22a, 22b...light source, 23, 23a, 23b...camera, 24...optical filter, 30...lens barrel, 31...lens, 32...image sensor, 32B...B light receiving element, 32G...G light receiving element, 32R...R light receiving element, 33...color filter, 33B...B filter, 33G...G filter, 33R...R filter, 40-45...G Rough, 98...near-infrared light cut filter, 99...container, 99a...body, 99b...neck, 99c...screw portion, 99d...mouth, 99e...bottom, FD...fluorescence distribution, FL...fluorescence spectrum, FR...fluorescence, Img...first image, IS...image signal, LS1...emission spectrum, LS2...emission spectrum, MD...conveying direction, NI...near-infrared light, NIRA...near-infrared wavelength region, R1...first region, R2...second region, R3...third region, R4...fourth region, S...imaging signal, SP...imaging position, UV...ultraviolet light, UVA...ultraviolet light wavelength region, VA...visible light wavelength region, Z...axial direction, θ1...first angle, θ2...second angle, θ3...third angle.

Claims

1. An object imaging device for imaging a transparent object having a transparent portion through which light can pass, a first light source that irradiates the article with light in a first wavelength range; A second light source that irradiates the transparent portion of the article with light in a second wavelength range; a camera that captures an image of the object at a position where light from the second light source that has passed through the transparent portion can be incident; an optical filter disposed in an optical path between the camera and the article; Equipped with the light in the first wavelength range includes ultraviolet light, The fluorescence emitted by the article excited by the light in the first wavelength range includes visible light in a third wavelength range, the second wavelength range is longer than the first wavelength range and the third wavelength range; the optical filter has optical properties of blocking light in the first wavelength range and transmitting light in the second wavelength range and visible light in the third wavelength range, The camera captures a first image of the item using visible light in the third wavelength range that can identify the inspection target area of ​​the item and light in the second wavelength range that can inspect the inspection target area of ​​the item, as an image of the item using light that has passed through the optical filter.

2. the second wavelength range includes a wavelength range of near-infrared light, The object imaging device according to claim 1 , wherein the third wavelength range includes a wavelength range of blue light.

3. The article is a container having a threaded portion on which a screw is formed on a cylindrical neck portion having a mouth portion on an end surface and extending along an axis, and a body portion formed on the neck portion on the opposite side to the end surface, the second light source irradiates the neck portion with light in the second wavelength range from a direction inclined at a predetermined angle from the axis, the optical filter is disposed on an optical path between the camera and the neck; The object imaging device according to claim 1 , wherein the camera captures the first image including the image of the neck portion from the end face side.

4. the second light source includes two light sources that irradiate the neck portion with light in the second wavelength range from directions inclined at different angles from the axis, the second light source is configured such that when one light source emits light at a first timing, the other light source is turned off, and when one light source is turned off at a second timing, the other light source emits light; 4. The object imaging device according to claim 3, wherein the camera captures one of the first images at the first timing and captures the other of the first images at the second timing.

5. The camera includes two cameras that capture images of the neck from different angles on the end surface side, 4. The object imaging device according to claim 3, wherein one of the cameras captures one of the first images, and the other of the cameras captures the other first image.

6. The imaging device according to any one of claims 1 to 5; an inspection processing unit that inspects the item based on an image obtained by the imaging device capturing an image of the item; Equipped with The inspection processing unit identifies an inspection target area of ​​the item based on a first image captured by visible light in the third wavelength range, and inspects the inspection target area of ​​the item based on a second image captured by light in the second wavelength range.

Images