Print inspection apparatus, printing apparatus, and printing inspection method

Abstract

SOLUTION: A print inspection device for inspecting an image printed on an inspection object container comprises: a first irradiation unit which irradiates the inspection object container with first irradiation light in a predetermined first waveband; a second irradiation unit which irradiates the inspection object container with second irradiation light including irradiation light in the first waveband and irradiation light in a second waveband different from the first waveband; and a light reception unit which receives regular reflection light of the first irradiation light reflected by the inspection object container and receives irregular reflection light of the second irradiation light reflected by the inspection object container.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a printing inspection apparatus, a printing apparatus, and a printing inspection method.

Background Art

[0002] Conventionally, it is known to determine whether printing on the surface of a container is acceptable or not based on RGB images and near-infrared light images (see, for example, Patent Document 1). [Prior Art Documents] [Patent Documents] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-142256

Summary of the Invention

Problems to be Solved by the Invention

[0003] There is provided a printing inspection apparatus that determines whether printing on the surface of a container is acceptable or not using first irradiation light in a first wavelength band and second irradiation light in the first wavelength band and a second wavelength band.

Means for Solving the Problems

[0004] In a first aspect of the present invention, there is provided a printing inspection apparatus for inspecting an image printed on an inspection target container, the printing inspection apparatus including: a first irradiation unit for irradiating the inspection target container with first irradiation light in a predetermined first wavelength band; a second irradiation unit for irradiating the inspection target container with second irradiation light including the irradiation light in the first wavelength band and irradiation light in a second wavelength band different from the first wavelength band; and a light receiving unit for receiving specularly reflected light of the first irradiation light reflected by the inspection target container and diffusely reflected light of the second irradiation light reflected by the inspection target container.

[0005] The first wavelength band may be in the visible light range. The second wavelength band may be in the infrared range.

[0006] The second irradiation unit may have a first light source that irradiates the container to be inspected with irradiation light in the first wavelength band. The second irradiation unit may have a second light source that mixes with the irradiation light from the first light source to irradiate the container to be inspected with irradiation light in the second wavelength band.

[0007] The second irradiation unit may have a first light source that irradiates the container to be inspected with irradiation light in the first wavelength band. The second irradiation unit may have a second light source that irradiates the container to be inspected with irradiation light in the second wavelength band without mixing it with the irradiation light from the first light source.

[0008] The light-receiving unit may have a first sensor for receiving specularly reflected light of the first wavelength band from the first irradiation unit and diffusely reflected light of the first wavelength band from the second irradiation unit. The light-receiving unit may have a second sensor for receiving diffusely reflected light of the second wavelength band from the second irradiation unit.

[0009] The first sensor may include three types of photodetectors, RGB, for receiving visible light. The second sensor may include a photodetector for receiving infrared light.

[0010] The light-receiving unit may have a line camera in which the light-receiving elements of the first sensor and the second sensor are arranged in a predetermined direction.

[0011] The print inspection apparatus may include an image data acquisition unit that acquires first image data from the first sensor and second image data from the second sensor. The print inspection apparatus may also include a determination unit that performs a pass / fail determination process for the image printed on the container to be inspected based on the first image data and the second image data.

[0012] The determination unit may perform a pass / fail determination process based on the data in the second image data that corresponds to the white area of ​​the image printed on the container to be inspected.

[0013] The image data acquisition unit may acquire image data in the visible light range as the first image data and image data in the infrared range as the second image data.

[0014] The container to be inspected may be a metal can.

[0015] A second embodiment of the present invention provides a printing apparatus comprising: a printing unit for printing a predetermined image onto a container to be inspected; a rotating unit for rotating the container on which the image has been printed; and the printing inspection device.

[0016] A third aspect of the present invention provides a printing inspection method for inspecting an image printed on a container to be inspected, comprising the steps of: irradiating the container to be inspected with a first irradiation light of a predetermined first wavelength band; irradiating the container to be inspected with a second irradiation light including the irradiation light of the first wavelength band and the irradiation light of a second wavelength band different from the first wavelength band; and receiving specularly reflected light of the first irradiation light reflected by the container to be inspected and receiving diffusely reflected light of the second irradiation light reflected by the container to be inspected.

[0017] The printing inspection method may include a step of simultaneously receiving the specularly reflected light of the first irradiation light and the diffusely reflected light of the second irradiation light.

[0018] The printing inspection method may include the steps of: acquiring first image data based on specular reflected light and diffuse reflected light of the first wavelength band; acquiring second image data based on diffuse reflected light of the second wavelength band; and performing a pass / fail determination process for the image printed on the container to be inspected based on the first image data and the second image data.

[0019] It should be noted that the above summary of the invention does not list all the necessary features of the present invention. Furthermore, subcombinations of these features may also constitute an invention. [Brief explanation of the drawing]

[0020] [Figure 1] An example of the configuration of the printing inspection device 100 is shown. [Figure 2] An example of an inspection target container 300 having a defective portion is shown. [Figure 3] This is an example of an inspection method by the printing inspection device 100. [Figure 4A] This is an example of an inspection method by the printing inspection device 500 which is a comparative example. [Figure 4B] This is an example of an inspection method by the printing inspection device 500 which is a comparative example. [Figure 5A] An example of the configuration of the second irradiation unit 20 is shown. [Figure 5B] A modified example of the second irradiation unit 20 is shown. [Figure 6] This is an example of a specific configuration of the light receiving unit 30. [Figure 7A] This is an example of a printing device 200 for printing an image on the inspection target container 300. [Figure 7B] An example of the configuration during inspection of the inspection target container 300 is shown.

Embodiments for Carrying Out the Invention

[0021] Hereinafter, the present invention will be described through embodiments of the invention. However, the following embodiments do not limit the invention according to the claims. Also, not all combinations of features described in the embodiments are essential for the solution means of the invention.

[0022] FIG. 1 shows an example of the configuration of the printing inspection device 100. The printing inspection device 100 inspects an image printed on an inspection target container 300. The printing inspection device 100 includes a first irradiation unit 10, a second irradiation unit 20, a light receiving unit 30, an image data acquisition unit 40, and a determination unit 50.

[0023] The container to be inspected 300 may be a can, PET bottle, glass bottle, pouch, box, paper carton, cup, or tube. The container to be inspected 300 may also be a lid or cap. In this example, the container to be inspected 300 is a metal can before the lid is attached. The container to be inspected 300 may be a two-piece can or a three-piece can. The metal material of the container to be inspected 300 may be an alloy such as aluminum or iron. Furthermore, the container to be inspected 300 may be a trim can formed by surface treatment, bending and stretching, ironing, or impact processing on a base material.

[0024] The image printed on the container 300 to be inspected may be a picture or a background. The image printed on the container 300 to be inspected may be a symbol, code, letter, number, figure, color, or a combination thereof. The image printed on the container 300 to be inspected may include white areas or areas of other colors.

[0025] The first irradiation unit 10 irradiates the container 300 to be inspected with a first irradiation light L1 in a predetermined first wavelength band B1. In this example, the first wavelength band B1 is in the visible light range, but is not limited thereto. The first irradiation unit 10 may have an LED or other light-emitting element. The first irradiation unit 10 functions as a light source for specularly reflected light received by the light-receiving unit 30. Specularly reflected light is reflected light from light incident on a reflective surface at a predetermined incident angle, and is reflected at the same reflection angle as the incident angle. Specularly reflected light may be generated by adjusting the optical relationship using a half mirror or the like.

[0026] The second irradiation unit 20 irradiates the container 300 to be inspected with a second irradiation light L2. The second irradiation light L2 may include irradiation light in the first wavelength band B1 and irradiation light in the second wavelength band B2 which is different from the first wavelength band B1. In this example, the second wavelength band B2 is in the infrared region, but is not limited to this. The first wavelength band B1 and the second wavelength band B2 may overlap in part or not. The first wavelength band B1 and the second wavelength band B2 may be wavelength bands that do not interfere with each other. The second irradiation unit 20 may have an light-emitting element such as an LED. The second irradiation unit 20 functions as a light source for diffusely reflected light received by the light-receiving unit 30. Diffusely reflected light may refer to reflected light other than specularly reflected light from the light incident on the reflective surface.

[0027] The light-receiving unit 30 receives light reflected from the outer circumference of the container 300 to be inspected, using the first irradiation unit 10 and the second irradiation unit 20 as light sources. In this example, the light-receiving unit 30 receives specularly reflected light Lr1 and diffusely reflected light Ld2. Specularly reflected light Lr1 is the specularly reflected light of the first irradiation light L1 reflected by the container 300 to be inspected. Diffusely reflected light Ld2 is the diffusely reflected light of the second irradiation light L2 reflected by the container 300 to be inspected. That is, the light-receiving unit 30 receives reflected light from both the first wavelength band B1 and the second wavelength band B2. In this example, the light-receiving unit 30 has a first sensor 31 and a second sensor 32.

[0028] The first sensor 31 has a light-receiving element for receiving light in the first wavelength band B1. In this example, the first sensor 31 receives specularly reflected light Lr1 in the first wavelength band B1 from the first irradiation unit 10 and diffusely reflected light Ld2 in the first wavelength band B1 from the second irradiation unit 20. The first sensor 31 receives light in the first wavelength band B1 but does not need to receive light in the second wavelength band B2. The first sensor 31 may be a visible light sensor for receiving visible light.

[0029] The second sensor 32 has a light-receiving element for receiving light in the second wavelength band B2. In this example, the second sensor 32 receives diffusely reflected light Ld2 in the second wavelength band B2 from the second irradiation unit 20. The second sensor 32 receives light in the second wavelength band B2, but does not need to receive light in the first wavelength band B1. The second sensor 32 may be an infrared light sensor for receiving infrared light.

[0030] The image data acquisition unit 40 acquires first image data D1 from the first sensor 31 and second image data D2 from the second sensor 32. Here, the first image data D1 includes information corresponding to the specular reflected light Lr1 and diffuse reflected light Ld2 of the first wavelength band B1. The second image data D2 includes information corresponding to the diffuse reflected light Ld2 of the second wavelength band B2. That is, the image data acquisition unit 40 can acquire the first image data D1 of the first wavelength band B1 and the second image data D2 of the second wavelength band B2 separately. The image data acquisition unit 40 may acquire image data in the visible light range as the first image data D1 and image data in the infrared range as the second image data D2.

[0031] The determination unit 50 performs pass / fail determination processing on the image printed on the container 300 to be inspected based on the first image data D1 and the second image data D2. The determination unit 50 may have a display unit such as a display for displaying the first image data D1 and the second image data D2. The user may make a pass / fail determination of the image based on the information displayed by the determination unit 50. The determination unit 50 may output the pass / fail determination result of the image to an external source. The determination unit 50 may have a speaker and output the pass / fail determination result of the image by voice.

[0032] The determination unit 50 may perform a pass / fail judgment process based on data in the second image data D2 that corresponds to the white areas of the image printed on the container 300 to be inspected. This allows the print inspection device 100 to inspect for white ink repellency on the container 300 to be inspected. The determination unit 50 may acquire positional information of the white areas of the image to be printed on the container 300 to be inspected in advance. For example, the determination unit 50 may identify the white areas from the original print image data and determine the pass / fail status of the image based on the identified areas. Alternatively, the determination unit 50 may identify the white areas from a visible light image of a container 300 that is free of defects.

[0033] In this example, the first wavelength band B1 is set to the visible light range and the second wavelength band B2 to the infrared range, but these can be appropriately changed depending on the image of the container 300 to be inspected. For example, the first wavelength band B1 may be set to the red range and the second wavelength band B2 to the blue range. In other words, the light used by the printing inspection device 100 can be separated and received by the light receiving unit 30, and is not limited to the visible light range and the infrared range, as long as it is light in a wavelength range that can distinguish the image to be inspected.

[0034] In this example, the second irradiation unit 20 irradiates with second irradiation light L2 in two wavelength bands, the first wavelength band B1 and the second wavelength band B2, but the irradiation light in the first wavelength band B1 may be omitted. However, the print inspection device 100 can inspect the visible light image more accurately by using diffusely reflected light Ld2 in the first wavelength band B1. In addition, since both the first image data D1 and the second image data D2 include diffusely reflected light Ld2, it becomes easier to adjust the images between the first image data D1 and the second image data D2.

[0035] Figure 2 shows an example of a container 300 to be inspected that has a defect. In this example, the container 300 to be inspected has a printed area 310 and a repelled area 312.

[0036] The printing area 310 is the area that the printing inspection device 100 is required to determine whether the print is acceptable or not. In this example, the printing area 310 is the area where white ink is printed.

[0037] The repelled area 312 is an area in the printed area 310 where the ink has been repelled due to a printing defect. The repelled area 312 may include areas with metallic luster, such as areas where the underlying metal material is exposed due to a printing defect. The repelled area 312 can be caused by the adhesion of water, oil, or dirt. The repelled area 312 can also be caused by dirt adhering to the container 300 under inspection. The repelled area 312 may also be caused by dirt adhering to the printing blanket or plate.

[0038] In the inspection using the first image data D1, which uses specular and diffuse reflected light, the white printed area 310 and the repelled area 312 of the metallic base material may be captured as the same color, making them indistinguishable. On the other hand, in the second image data D2, which uses only diffuse reflected light, the white area becomes brighter and the metallic base material becomes darker. As a result, the print inspection device 100 can distinguish between the white area and the repelled area. Areas other than white may be inspected using the first image data D1.

[0039] In this example, we have described the case where white ink is applied to a metal base, but the container 300 to be inspected by the printing inspection device 100 is not limited to this. The container 300 to be inspected may be an area on a white base to which an image of another color has been printed. By a similar principle, the printing inspection device 100 can distinguish between areas with different L values ​​in Lab space and make a pass / fail determination. In this case, the printing inspection device 100 can inspect areas with different ink thicknesses as areas with different L values ​​in Lab space.

[0040] Figure 3 shows an example of an inspection method using the print inspection device 100. In this example, the print inspection device 100 irradiates the container 300 to be inspected with a first irradiation light L1 in the first wavelength band B1 and a second irradiation light L2 in the first wavelength band B1 and the second wavelength band B2.

[0041] The light-receiving unit 30 receives specularly reflected light Lr1 in the first wavelength band B1 and diffusely reflected light Ld2 in both the first wavelength band B1 and the second wavelength band B2. Therefore, the light-receiving unit 30 can receive reflected light from multiple wavelength bands with a single irradiation. Since the light-receiving unit 30 has a first sensor 31 that receives light in the first wavelength band B1 and a second sensor 32 that receives light in the second wavelength band B2, it can acquire first image data D1 from specularly reflected light Lr1 (B1) and diffusely reflected light Ld2 (B1) in the first wavelength band B1, and second image data D2 from diffusely reflected light Ld2 (B2) in the second wavelength band B2, with a single imaging. In other words, the light-receiving unit 30 can simultaneously receive specularly reflected light Lr1 from the first irradiation light L1 and diffusely reflected light Ld2 from the second irradiation light L2. Furthermore, the specularly reflected light Lr2 from the second irradiation unit 20 does not need to be received by the light receiving unit 30.

[0042] Figure 4A shows an example of an inspection method using a comparative example, the print inspection apparatus 500. The comparative example print inspection apparatus 500 comprises a first irradiation unit 510, a second irradiation unit 520, and a light receiving unit 530. The first irradiation unit 510 and the second irradiation unit 520 irradiate the container 300 to be inspected with visible light. The light receiving unit 530 is a visible light sensor.

[0043] In this example, the printing inspection device 500 illuminates the container to be inspected 300 with both the first irradiation unit 510 and the second irradiation unit 520. The printing inspection device 500 receives specularly reflected light Lr510(VL) and diffusely reflected light Ld520(VL) in the visible light range and acquires a visible light image of the container to be inspected 300. That is, since all the light incident on the light receiving unit 530 is visible light, the printing inspection device 500 needs to switch off the light source of the first irradiation unit 510 and acquire an image in order to extract the image data of the diffusely reflected light Ld520(VL).

[0044] Figure 4B shows an example of an inspection method using a comparative example, the print inspection apparatus 500. In this example, the print inspection apparatus 500 turns off the first irradiation unit 510 and irradiates the container to be inspected 300 with only the second irradiation unit 520. The light receiving unit 530 separates the diffusely reflected light Ld520(VL) from the specularly reflected light Lr510(VL) and receives the light. As a result, the print inspection apparatus 500 can detect the rejection region 312 of the container to be inspected 300. Thus, in the comparative example print inspection apparatus 500, it is necessary to switch the light source in order to acquire only the diffusely reflected light image.

[0045] In contrast, the printing inspection device 100 uses a second irradiation light L2 in the first wavelength band B1 and the second wavelength band B2, eliminating the need to switch light sources and allowing inspection to be performed with a single irradiation. This reduces the inspection time for the container 300 to be inspected. Furthermore, since the printing inspection device 100 can perform inspection with a single irradiation, it simplifies image data processing compared to cases where two sets of image data are used.

[0046] Figure 5A shows an example of the configuration of the second irradiation unit 20. In this example, the second irradiation unit 20 has a first light source 21 and a second light source 22.

[0047] The first light source 21 irradiates the container 300 to be inspected with illumination light in the first wavelength band B1. In this example, the first light source 21 irradiates the container 300 to be inspected with visible light from the second illumination light L2. The second light source 22 irradiates the container 300 to be inspected with illumination light in the second wavelength band B2 without mixing it with the illumination light from the first light source 21. In this example, the second light source 22 irradiates the container 300 to be inspected with illumination light in the infrared region from the second illumination light L2.

[0048] The second irradiation unit 20 may be arranged with the first light source 21 and the second light source 22 in close proximity. Alternatively, the second irradiation unit 20 may be arranged with the first light source 21 and the second light source 22 spaced apart, irradiating the container 300 to be inspected from different positions. In this example, the second irradiation unit 20 allows for free positioning of the first light source 21 and the second light source 22, thus improving the flexibility of the mounting layout.

[0049] Figure 5B shows a modified example of the second irradiation unit 20. In this example, the second irradiation unit 20 has a first light source 21, a second light source 22, and a mixing unit 23.

[0050] The first light source 21 irradiates the container 300 to be inspected with light in the first wavelength band B1. In this example, the first light source 21 irradiates with visible light. The second light source 22 mixes with the light from the first light source 21 to irradiate the container 300 to be inspected with light in the second wavelength band B2. In this example, the second light source 22 uses a mixing unit 23 to mix with the light from the first wavelength band B1 to irradiate the container 300 to be inspected with light from the second wavelength band B2.

[0051] The mixing unit 23 is connected to the first light source 21 and the second light source 22. The mixing unit 23 may mix the irradiation light from the first light source 21 and the second light source 22 by mixing fibers internally. That is, the mixing unit 23 irradiates with a second irradiation light L2 that includes a first wavelength band B1 and a second wavelength band B2. In this example, the second irradiation unit 20 can irradiate the container 300 to be inspected from the same direction by mixing the first irradiation light L1 and the second irradiation light L2.

[0052] Figure 6 shows an example of the specific configuration of the light-receiving unit 30. The light-receiving unit 30 has a line camera in which the light-receiving elements of the first sensor 31 and the second sensor 32 are arranged in a predetermined direction. However, the type of light-receiving unit 30 is not limited to a line camera.

[0053] The first sensor 31 includes three types of photodetectors, RGB, for receiving visible light. The letters RGB in the figure indicate the positions of the respective photodetectors. The first sensor 31 has a photodetector R arranged in a predetermined arrangement direction, a photodetector G arranged in the same arrangement direction, and a photodetector B arranged in the same arrangement direction. The three RGB photodetectors may be arranged in a direction perpendicular to the arrangement direction.

[0054] The second sensor 32 includes a photodetector for receiving infrared light. The letters IR in the figure indicate the position of the photodetector for receiving infrared light. The second sensor 32 has photodetector IR arranged in a predetermined arrangement direction. The arrangement method of the photodetector may be other arrangement methods such as a Bayer array.

[0055] Figure 7A shows an example of a printing device 200 for printing an image onto a container 300 to be inspected. The printing device 200 comprises a printing unit 210 and a container supply / discharge unit 220, and prints a predetermined image onto the container 300 to be inspected. The image printed on the container 300 to be inspected is then inspected by a print inspection device 100.

[0056] The printing unit 210 prints a predetermined image onto the container 300 to be inspected. The printing unit 210 comprises an ink station 212, a plate cylinder 214, a blanket 215, a blanket cylinder 217, and a rotating shaft 218. In this example, the printing unit 210 has six types of ink stations 212 and plate cylinders 214, but the type of ink is not limited thereto.

[0057] The ink station 212 stores ink of a predetermined color and supplies it to the plate supported by the plate cylinder 214. The ink station 212 may have a foam roller for supplying ink. The ink station 212 supplies ink to the plate on the plate cylinder 214 via the foam roller.

[0058] The blanket 215 is a rubber-like component that transfers the ink placed by each ink station 212. The blanket 215 is supported on the outer circumference of the blanket cylinder 217. The blanket 215 is moved to a position corresponding to each ink station 212 in accordance with the rotation of the blanket cylinder 217 around the rotation axis 218. The blanket 215 successively comes into contact with the plate body of each plate cylinder 214, and ink is placed on the blanket 215.

[0059] The blanket 215 is moved between the blanket cylinder 217 and the mandrel turret 224 and pressed between the blanket cylinder 217 and the container 300 to be inspected. As a result, the ink placed on the blanket 215 is transferred to the container 300 to be inspected.

[0060] The container supply and discharge unit 220 includes a chute 222, a mandrel turret 224, a transfer turret 226, a vanish coating unit 228, and a discharge path 229. The containers to be inspected 300 pass through the chute 222 and are transported to the mandrel turret 224.

[0061] The mandrel turret 224 is positioned opposite the blanket cylinder 217. The mandrel turret 224 holds the container to be inspected 300 and rotates it to a position opposite the blanket 215. Then, the container to be inspected 300 is printed between the mandrel turret 224 and the blanket cylinder 217.

[0062] Subsequently, the container 300 to be inspected is transported to the transport route 229 via the transfer turret 226. The vanish coating section 228 is located adjacent to the mandrel turret 224 and may apply an over-vanish to the container 300 to be inspected after the printing process.

[0063] Figure 7B shows an example of the configuration during inspection of the container 300 to be inspected. The print inspection device 100 may inspect the image of the container 300 at any step after the printing process of the container 300. The print inspection device 100 may be installed after the container has been discharged via the discharge route 229.

[0064] The rotating unit 230 rotates the container 300 on which the image is printed. In this example, the rotating unit 230 has a mandrel sleeve for supporting and rotating the inside of the container 300. The printing inspection device 100 inspects the container 300 by photographing it as it is rotated by the rotating unit 230. However, the printing inspection device 100 may also inspect the container 300 by photographing it while it is stationary.

[0065] The printing inspection device 100 may continuously or intermittently irradiate a single container 300 to be inspected with light. If the container 300 to be inspected is a metal can, the metal can may be inspected before the can lid is attached to the container 300, or it may be inspected after the contents have been filled into the metal can.

[0066] Although the present invention has been described above using embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. It will be apparent to those skilled in the art that various modifications or improvements can be made to the above embodiments. It will be clear from the claims that such modified or improved forms may also be included in the technical scope of the present invention.

[0067] It should be noted that the execution order of operations, procedures, steps, and stages in the apparatus, systems, programs, and methods shown in the claims, specifications, and drawings is not explicitly stated as "before," "prior to," etc., and that these can be implemented in any order unless the output of a previous process is used in a later process. Even if the operation flow in the claims, specifications, and drawings is described using phrases such as "first," "next," etc. for convenience, it does not mean that it is essential to perform the operations in that order. [Explanation of symbols]

[0068] 10...First irradiation unit, 20...Second irradiation unit, 21...First light source, 22...Second light source, 23...Mixing unit, 30...Light receiving unit, 31...First sensor, 32...Second sensor, 40...Image data acquisition unit, 50...Determination unit, 100...Print inspection device, 200...Printing device, 210...Printing unit, 212...Ink station, 214...Plate cylinder, 215...Blanket, 217...Blanket 218... Rotating shaft, 222... chute, 224... mandrel turret, 226... transfer turret, 228... vanish coating section, 229... discharge path, 220... container supply and discharge section, 230... rotating section, 300... container to be inspected, 310... printing area, 312... rejection area, 510... first irradiation section, 520... second irradiation section, 530... light receiving section, 500... printing inspection device

Claims

1. A print inspection device for inspecting an image printed on a container to be inspected, A first irradiation unit for irradiating the container to be inspected with a first irradiation light in a predetermined first wavelength band, A second irradiation unit for irradiating the container to be inspected with irradiation light in the first wavelength band and irradiation light in a second wavelength band different from the first wavelength band, A light receiving unit that receives specularly reflected light of the first irradiation light reflected by the container to be inspected, and receives diffusely reflected light of the second irradiation light reflected by the container to be inspected, Equipped with, The second irradiation unit is, A first light source that irradiates the container to be inspected with irradiation light in the first wavelength band, A second light source that irradiates the container to be inspected with light in the second wavelength band, A printing inspection device having the following features.

2. A print inspection device for inspecting an image printed on a container to be inspected, A first irradiation unit for irradiating the container to be inspected with a first irradiation light in a predetermined first wavelength band, A second irradiation unit for irradiating the container to be inspected with irradiation light in the first wavelength band and irradiation light in a second wavelength band different from the first wavelength band, A light receiving unit that receives specularly reflected light of the first irradiation light reflected by the container to be inspected, and receives diffusely reflected light of the second irradiation light reflected by the container to be inspected, Equipped with, The first wavelength band is the visible light region, and the second wavelength band is the infrared region. Print inspection device.

3. A mixing unit connected to the first light source and the second light source, which mixes the light emitted from the first light source and the second light source and irradiates the container to be inspected with it. The printing inspection apparatus according to claim 1.

4. The second light source irradiates the container to be inspected with light of the second wavelength band without mixing it with the light of the first light source. The printing inspection apparatus according to claim 1.

5. The light receiving unit is A first sensor for receiving specularly reflected light in the first wavelength band from the first irradiation unit and diffusely reflected light in the first wavelength band from the second irradiation unit, A second sensor for receiving diffusely reflected light of the second wavelength band from the second irradiation unit, A printing inspection apparatus according to any one of claims 1 to 4.

6. The first sensor includes three types of RGB light-receiving elements for receiving visible light, The second sensor includes a photodetector for receiving light in the infrared region. The printing inspection apparatus according to claim 5.

7. The light-receiving unit has a line camera in which the light-receiving elements of the first sensor and the second sensor are arranged in a predetermined direction. The printing inspection apparatus according to claim 5 or 6.

8. An image data acquisition unit that acquires first image data from the first sensor and second image data from the second sensor, A determination unit performs a pass / fail determination process on the image printed on the container to be inspected based on the first image data and the second image data, A printing inspection apparatus according to any one of claims 5 to 7, comprising:

9. The determination unit performs a pass / fail determination process based on the data in the second image data that corresponds to the white area of ​​the image printed on the container to be inspected. The printing inspection apparatus according to claim 8.

10. The image data acquisition unit acquires image data in the visible light range as the first image data and image data in the infrared range as the second image data. The printing inspection apparatus according to claim 8 or 9.

11. The container to be inspected is a metal can. A printing inspection apparatus according to any one of claims 1 to 10.

12. A printing unit for printing a predetermined image onto the container to be inspected, A rotating part for rotating the container to be inspected, on which the aforementioned image is printed, A printing inspection apparatus according to any one of claims 1 to 11, A printing device equipped with the following features.

13. A print inspection method for inspecting an image printed on a container to be inspected, The steps include irradiating the container to be inspected with a first irradiation light in a predetermined first wavelength band, A step of irradiating the container to be inspected with a second irradiation light including irradiation light in the first wavelength band and irradiation light in a second wavelength band different from the first wavelength band, The steps include receiving the specularly reflected light of the first irradiation light reflected by the container to be inspected, and receiving the diffusely reflected light of the second irradiation light reflected by the container to be inspected, Equipped with, The step of irradiating with the second irradiation light is, The steps include: irradiating the container to be inspected with irradiation light in the first wavelength band from the first light source; The steps include: irradiating the container to be inspected with light in the second wavelength band from the second light source; A printing inspection method having [specific features].

14. The process includes a step of simultaneously receiving the specularly reflected light of the first irradiation light and the diffusely reflected light of the second irradiation light. The printing inspection method according to claim 13.

15. A step of acquiring first image data based on specularly reflected light in the first wavelength band and diffusely reflected light in the first wavelength band, A step of acquiring a second image data based on diffusely reflected light in the second wavelength band, A step of performing a pass / fail determination process on the image printed on the container to be inspected based on the first image data and the second image data, The printing inspection method according to claim 13 or 14, comprising:

16. A print inspection method for inspecting an image printed on a container to be inspected, The steps include irradiating the container to be inspected with a first irradiation light in a predetermined first wavelength band, A step of irradiating the container to be inspected with a second irradiation light including irradiation light in the first wavelength band and irradiation light in a second wavelength band different from the first wavelength band, The steps include receiving the specularly reflected light of the first irradiation light reflected by the container to be inspected, and receiving the diffusely reflected light of the second irradiation light reflected by the container to be inspected, Equipped with, A printing inspection method wherein the first wavelength band is in the visible light range and the second wavelength band is in the infrared range.

Images