JP2019148461A - Near infrared ray inspection device - Google Patents

Abstract

To provide a near infrared ray inspection device capable of accurately inspecting whether a trapped matter exists in the sealed part of a package.SOLUTION: A near infrared ray inspection device 1 for inspecting whether in an article 10 having a package 11 and a content 12, a trapped matter F exists in the sealed part 11a of the package 11 comprises: a light irradiating part 3 for irradiating a conveyed articles 10 with a first near infrared ray IR1 having a first wavelength and a second near infrared ray IR2 having a second wavelength; an imaging part 4 for imaging a first image IM1 of the article 10 by the first near infrared ray IR1 and a second image IM2 of the article 10 by the second near infrared ray IR2; and an image formation part 5 for forming a difference image IM3 between the first image IM1 and the second image IM2. The absorptivity of the first near infrared ray IR1 by the trapped matter F is higher than that of the second near infrared ray IR2 by the trapped matter F.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a near-infrared inspection apparatus.

  In the production line of articles having contents such as food packaging and other packages such as film packaging materials, the product is transported by an optical inspection device in order to prevent the shipment of articles that have bites in the sealing part of the package. In some cases, it is inspected whether or not there is a bite in the package sealing portion of the article (see, for example, Patent Document 1).

JP 2012-189563 A

  In the production line as described above, it is desirable to be able to accurately inspect whether there is a bite in the sealed portion of the package without depending on the form of the package (for example, whether or not printing is performed). ing.

  An object of this invention is to provide the near-infrared inspection apparatus which can test | inspect accurately whether the biting thing exists in the sealing part of a package.

  A near-infrared inspection apparatus according to the present invention is a near-infrared inspection apparatus for inspecting whether or not a bite exists in a sealing portion of a package in an article having a package and contents. A light irradiation unit that irradiates a first near-infrared ray having a first wavelength and a second near-infrared ray having a second wavelength, and an imaging that takes a first image of the article by the first near infrared ray and a second image of the article by the second near infrared ray. And an image generation unit that generates a difference image between the first image and the second image, and the absorption rate of the first near infrared ray by the biting object is greater than the absorption rate of the second near infrared ray by the biting object Is also expensive.

  According to this near-infrared inspection apparatus, by generating a difference image between the first image of the article using the first near infrared and the second image of the article using the second near infrared, for example, printing is performed on the sealing portion of the package. Even in such a case, the biting object existing in the sealed portion of the package can be emphasized in the difference image. Therefore, according to this near infrared ray inspection apparatus, it is possible to accurately inspect whether or not a biting object exists in the sealing portion of the package.

  In the near-infrared inspection apparatus of the present invention, the imaging unit captures the first reflected light image of the article by the first near infrared as the first image, and the second reflected light image of the article by the second near infrared as the second image. You may image. For example, the package is configured by sticking a film-like seal transparent to the first near infrared ray and the second near infrared ray on a tray that is opaque to the first near infrared ray and the second near infrared ray. It is effective in such a case.

  In the near-infrared inspection apparatus of the present invention, a first material transparent to each of the first near-infrared light and the second near-infrared light, and a second material opaque to each of the first near-infrared light and the second near-infrared light, When the sealing part is configured by overlapping, the light irradiation part irradiates the sealing part with the first near infrared ray and the second near infrared ray from the first material side, and the imaging part The first near infrared ray and the second near infrared ray that are transmitted through the first material and reflected by the second material may be detected. For example, the package is configured by sticking a film-like seal transparent to the first near infrared ray and the second near infrared ray on a tray that is opaque to the first near infrared ray and the second near infrared ray. It is effective in such a case.

  In the near-infrared inspection apparatus of the present invention, the imaging unit captures the first transmitted light image of the article by the first near infrared as the first image, and the second transmitted light image of the article by the second near infrared as the second image. You may image. This configuration is effective, for example, when the package is formed of a film packaging material that is transparent to the first near infrared ray and the second near infrared ray.

  In the near-infrared inspection apparatus of the present invention, when a sealing part is configured by superimposing a transparent material on each of the first near-infrared ray and the second near-infrared ray, the imaging part is sealed. You may detect the 1st near infrared ray and the 2nd near infrared ray which permeate | transmitted the stop part. This configuration is effective, for example, when the package is formed of a film packaging material that is transparent to the first near infrared ray and the second near infrared ray.

  The near-infrared inspection apparatus of the present invention may further include a determination unit that determines whether there is a bite in the sealing unit based on the difference image. According to this configuration, an article in which a bite is present in the sealed portion of the package can be automatically discharged from the production line.

  In the near-infrared inspection apparatus of the present invention, the determination unit extracts a region corresponding to the sealing unit in the difference image, and when a portion having a predetermined luminance value difference exists in the region, the biting object is in the sealing unit. You may determine that it exists. According to this configuration, it can be easily and accurately determined whether or not a biting object exists in the sealing portion of the package.

  In the near-infrared inspection apparatus of the present invention, the light irradiating unit alternately irradiates the first near-infrared ray and the second near-infrared ray at a predetermined cycle, and the imaging unit is at least one arranged in a direction corresponding to the conveyance width direction. You may image with a predetermined period for every pixel row | line | column of a row | line | column. According to this configuration, the first image and the second image can be captured by one imaging unit.

  In the near-infrared inspection apparatus of the present invention, the image generation unit may generate a difference image by complementing regions corresponding to missing pixel columns in each of the first image and the second image. According to this configuration, a difference image can be generated easily and accurately.

  In the near-infrared inspection apparatus of the present invention, the first wavelength may be longer than the wavelength obtained by multiplying the second wavelength by 0.8, and may be shorter than the wavelength obtained by multiplying the second wavelength by 1.2. According to this configuration, while sufficiently ensuring the difference between the absorption rate of the first near-infrared ray by the biting object and the absorption rate of the second near-infrared ray by the biting object, the influence of the aberration in the imaging unit is suppressed, A differential image can be generated with high accuracy.

  The near-infrared inspection apparatus of the present invention may further include a transport unit that transports articles. According to this configuration, the imaging of the first image of the article using the first near infrared ray and the second image of the article using the second near infrared ray can be appropriately interlocked with the conveyance of the article.

  ADVANTAGE OF THE INVENTION According to this invention, it can test | inspect accurately whether the biting thing exists in the sealing part of a package.

It is a perspective view of the near-infrared inspection apparatus of one embodiment of the present invention. It is a bottom view of the light irradiation part of the near-infrared inspection apparatus of FIG. It is a figure which shows the image imaged by the imaging part of the near-infrared inspection apparatus of FIG. It is a figure which shows the image imaged by the imaging part of the near-infrared inspection apparatus of FIG. It is a figure which shows the image imaged by the imaging part of the near-infrared inspection apparatus of FIG. It is a figure which shows the image imaged by the imaging part of the near-infrared inspection apparatus of FIG. It is a front view of the modification of the near-infrared inspection apparatus of FIG. It is a side view of the modification of the near-infrared inspection apparatus of FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, in each figure, the same code | symbol is attached | subjected to the same or an equivalent part, and the overlapping description is abbreviate | omitted.

  As shown in FIG. 1, the near-infrared inspection apparatus 1 uses a product 11 having a package 11 and contents 12 as an inspection target in a production line of the product 10, and a sealed portion 11 a of the package 11 in the product 10 to be conveyed. It is an apparatus for inspecting whether or not the bitten object F exists in the. The article 10 determined by the near-infrared inspection apparatus 1 that the bite F exists in the sealing part 11a is discharged from the production line of the article 10 as a defective product. As an example, the package 11 is configured by attaching a film-like seal 14 to a tray 13, and the content 12 is food such as rice.

  The near-infrared inspection apparatus 1 includes a transport unit 2, a light irradiation unit 3, an imaging unit 4, an image generation unit 5, and a determination unit 6. The transport unit 2 is configured by, for example, a belt conveyor, and transports the article 10 along the transport direction A. The article 10 is transported in a state where the tray 13 is disposed on the transport surface 2 a of the transport unit 2. Hereinafter, a direction parallel to the transport surface 2a and perpendicular to the transport direction A is referred to as a transport width direction B.

  The light irradiation unit 3 is disposed above the transport surface 2 a of the transport unit 2. The light irradiation unit 3 irradiates the article 10 conveyed by the conveyance unit 2 with the first near-infrared IR1 having the first wavelength and the second near-infrared IR2 having the second wavelength. As an example, the light irradiation part 3 has the 1st light source 31 and the 2nd light source 32 which are located in a line along the conveyance width direction B, as FIG. 2 shows. The first light source 31 includes a plurality of first LEDs 31 a arranged along the transport width direction B. Each first LED 31a irradiates the transport surface 2a with the first near-infrared IR1. The second light source 32 includes a plurality of second LEDs 32 a arranged along the transport width direction B. Each 2nd LED32a irradiates 2nd near-infrared IR2 with respect to the conveyance surface 2a.

  The absorption rate of the first near-infrared IR1 by the biting matter F is higher than the absorption rate of the second near-infrared IR2 by the biting matter F. That is, the first near-infrared IR1 is more easily absorbed by the bite F than the second near-infrared IR2, and the second near-infrared IR2 is less likely to be absorbed by the bite F than the first near-infrared IR1. In other words, the reflectance of the first near-infrared IR1 due to the biting object F is lower than the reflectance of the second near-infrared IR2 due to the biting object F. That is, the first near-infrared IR1 is less likely to be reflected by the biting matter F than the second near-infrared IR2, and the second near-infrared IR2 is more likely to be reflected by the biting matter F than the first near-infrared IR1.

  The first wavelength of the first near infrared ray IR1 is longer than the wavelength obtained by multiplying the second wavelength of the second near infrared ray IR2 by 0.8 and the wavelength obtained by multiplying the second wavelength of the second near infrared ray IR2 by 1.2. Also short. More preferably, the first wavelength of the first near-infrared IR1 is longer than the wavelength obtained by multiplying the second wavelength of the second near-infrared IR2 by 0.85, and 1.15 is added to the second wavelength of the second near-infrared IR2. Shorter than the multiplied wavelength. More preferably, the first wavelength of the first near-infrared IR1 is longer than the wavelength obtained by multiplying the second wavelength of the second near-infrared IR2 by 0.88, and the first wavelength of the second near-infrared IR2 is 1.12. Shorter than the multiplied wavelength. For example, when the bitten matter F contains moisture such as rice, the first wavelength of the first near infrared IR1 is 1450 nm, and the second wavelength of the second near infrared IR2 is 1300 nm. In addition, when 1st near-infrared IR1 is light which has a wavelength range, 1st wavelength means the center wavelength (peak wavelength) of the said wavelength range. Similarly, when the second near-infrared IR2 is light having a wavelength range, the second wavelength means the center wavelength (peak wavelength) of the wavelength range.

  Here, the tray 13 is a material (second material) that is opaque to each of the first near-infrared IR1 and the second near-infrared IR2, and each of the first near-infrared IR1 and the second near-infrared IR2 by the tray 13 is used. The reflectivity of is comparable. The seal 14 (including the printed region) is a material (first material) that is transparent to each of the first near-infrared IR1 and the second near-infrared IR2, and the seal 14 (the region that has been printed). The transmittance of each of the first near-infrared IR1 and the second near-infrared IR2 is approximately the same. The sealing portion 11a of the package 11 is irradiated with the first near-infrared IR1 and the second near-infrared IR2 from the seal 14 side (that is, from the side opposite to the tray 13).

  As shown in FIG. 1, the imaging unit 4 is disposed above the transport surface 2 a of the transport unit 2. That is, the light irradiation unit 3 and the imaging unit 4 are disposed on the same side (the side on which the seal 14 is attached to the tray 13) with respect to the conveyance surface 2 a of the conveyance unit 2. The imaging unit 4 captures a first image of the article 10 by the first near infrared IR1 and a second image of the article 10 by the second near infrared IR2. Here, the imaging unit 4 captures the first reflected light image of the article 10 by the first near infrared IR1 as the first image, and captures the second reflected light image of the article 10 by the second near infrared IR2 as the second image. To do. As an example, the imaging unit 4 is a line sensor including a plurality of PDs arranged along the conveyance width direction B. In FIG. 1, the imaging unit 4 is disposed on the upstream side of the light irradiation unit 3 in the transport direction A, but the light irradiation unit 3 may be disposed on the upstream side of the imaging unit 4 in the transport direction A. .

  The light irradiation unit 3 alternately irradiates the first near-infrared IR1 and the second near-infrared IR2 with a predetermined period T. Here, in the light irradiation unit 3, the first light source 31 and the second light source 32 are alternately turned on and off in a cycle T. The imaging unit 4 captures an image with a period T for each pixel column arranged in a direction corresponding to the conveyance width direction B. As a result, as shown in FIG. 3, one pixel row constituting the first image IM1 of the article 10 by the first near-infrared IR1 and the second image IM2 of the article 10 by the second near-infrared IR2 are constituted. One pixel column is imaged with a period T. As an example, the period T is 2000 μs, and the conveyance speed V of the article 10 by the conveyance unit 2 is 250 mm / s.

  The period T (that is, the operation timing of the light irradiation unit 3 and the imaging unit 4) and the conveyance speed V are controlled by a control unit (not shown) that controls the operation of the near-infrared inspection apparatus 1. The control unit is configured as a computer apparatus including a processor, a memory, a storage, a communication device, and the like, for example. In this case, in the control unit, the processor executes predetermined software (program) read into the memory or the like, and controls reading and writing of data in the memory and the storage, and communication between the control devices by the communication device. Thus, the function of the control unit is realized.

  The image generation unit 5 generates a difference image between the first image IM1 and the second image IM2. Here, as shown in FIG. 4A, the first image IM1 is composed of a plurality of pixel columns arranged every other column. Similarly, as shown in FIG. 4B, the second image IM2 includes a plurality of pixel columns arranged every other column. Therefore, the image generation unit 5 complements the regions corresponding to the missing pixel columns in each of the first image IM1 and the second image IM2, and the second image IM2 complemented with the complemented first image IM1. A difference image is generated. As an example, the image generation unit 5 sandwiches each pixel in the direction corresponding to the transport direction A with the luminance value of each pixel included in each missing pixel row in each of the first image IM1 and the second image IM2. By setting the average value of the luminance values of the two pixels (may be an estimated value based on the change tendency of the luminance value in the conveyance direction A), the regions corresponding to the missing pixel columns are complemented. For example, the image generation unit 5 is functionally configured in the above-described control unit.

  FIG. 5A shows a first image IM1 of the article 10 based on the first near infrared IR1, and FIG. 5B shows a second image IM2 of the article 10 based on the second near infrared IR2. More specifically, the first image IM1 shown in FIG. 5A is a reflected light image of the article 10 by the first near-infrared IR1 having a wavelength of 1450 nm, and the second image shown in FIG. 5B. The image IM2 is a reflected light image of the article 10 by the second near-infrared IR2 having a wavelength of 1300 nm. Actually, there is a bite F in the upper left corner of the sealing portion 11a of the package 11 (the portion circled in FIGS. 5A and 5B), but even in the first image IM1 It is difficult to determine the bitten object F even in the second image IM2. Since the absorption rate of the first near-infrared IR1 by the biting matter F is higher than the absorption rate of the second near-infrared IR2 by the biting matter F, the portion circled in FIG. The bite F appears dark.

  FIG. 6 is a difference image IM3 between the first image IM1 shown in (a) of FIG. 5 and the second image IM2 shown in (b) of FIG. In the difference image IM3, the effects of printing applied to the sealing portion 11a of the package 11, shadows, etc. generated on the sealing portion 11a of the package 11 are canceled, and the upper left corner of the sealing portion 11a of the package 11 is canceled. The biting thing F existing in (the part circled in FIG. 6) is emphasized. Note that the image generation unit 5 performs a process of aligning the luminance value of the first image IM1 and the luminance value of the second image IM2 in order to generate the difference image IM3. Specifically, when the maximum brightness value of the first image IM1 is N1 and the maximum brightness value of the second image IM2 is N2, the brightness value of each pixel of the second image IM2 is set to N1 /. N2 times. Alternatively, when the average value of the luminance values of the first image IM1 is AVE1 and the average value of the luminance values of the second image IM2 is AVE2, the luminance value of each pixel of the second image IM2 is multiplied by AVE1 / AVE2. .

  The determination unit 6 determines whether or not the bitten object F exists in the sealing unit 11a of the package 11 based on the difference image IM3. Here, the determination unit 6 extracts a region corresponding to the sealing unit 11a in the difference image IM3 by, for example, mask processing, and a portion having a predetermined luminance value difference is converted into the sealing unit 11a by, for example, binarization processing. When it exists in a corresponding area | region, it determines with the biting thing F existing in the sealing part 11a. The determination unit 6 is downstream of the near-infrared inspection apparatus 1 in the transport direction A so that the article 10 determined to have the bitten object F in the sealing part 11a is discharged from the production line of the article 10 as a defective product. A signal is transmitted to a sorting device (not shown) arranged in the box. The determination unit 6 is functionally configured, for example, in the control unit described above. Note that the determination unit 6 can also detect wrinkles, folds, deformations, etc. (defects during molding) generated in the package 11 based on at least one of the first image IM1, the second image IM2, and the difference image IM3.

  As described above, in the near-infrared inspection apparatus 1, when the article 10 is irradiated with the first near-infrared IR 1 and the second near-infrared IR 2 from the seal 14 side, the first near-infrared light is emitted from the sealing portion 11 a of the package 11. IR1 and second near-infrared IR2 pass through the seal 14 and are reflected by the tray 13. At this time, since the absorption rate of the first near-infrared IR1 by the bite F is higher than the absorption rate of the second near-infrared IR2 by the bite F, the bite F exists in the sealing portion 11a. The first near-infrared IR1 is absorbed by the bitten matter F more than the second near-infrared IR2. Therefore, in the difference image IM3 between the first image IM1 of the article 10 by the first near infrared IR1 and the second image IM2 of the article 10 by the second near infrared IR2, for example, the sealing portion 11a seems to be printed. Even in this case, the bite F existing in the sealing portion 11a is emphasized. Therefore, according to the near-infrared inspection apparatus 1, it is possible to accurately inspect whether or not the bite F exists in the sealing portion 11 a of the package 11.

  Even if the seal 14 is transparent to visible light in the sealing portion 11a, the tray 13 and the biting object F are the same color, or the biting object F is transparent to visible light. Then, it is difficult to find the bite F with visible light. In addition, when the seal 14 is printed with red, for example, in the sealing portion 11a, for example, although the near infrared ray has high transparency with respect to the red print, the biting matter F is found with visible light. Have difficulty. Therefore, as described above, it is extremely effective to inspect the presence or absence of the biting object F with the first near infrared IR1 and the second near infrared IR2.

  Further, in the near-infrared inspection apparatus 1, the imaging unit 4 captures the first reflected light image of the article 10 by the first near infrared IR1 as the first image IM1, and the article 10 by the second near infrared IR2 as the second image IM2. The second reflected light image is taken. More specifically, in the near-infrared inspection apparatus 1, the first material transparent to each of the first near-infrared IR1 and the second near-infrared IR2, and the first near-infrared IR1 and the second near-infrared IR2, respectively. On the other hand, when the sealing part 11a is configured by overlapping the opaque second material, the light irradiation part 3 moves from the first material side to the sealing part 11a in the first near infrared IR1. The imaging unit 4 detects the first near-infrared IR1 and the second near-infrared IR2 that are transmitted through the first material and reflected by the second material. As described above, for example, the configuration is such that the tray 13 that is opaque to the first near-infrared IR1 and the second near-infrared IR2 has a film-like shape that is transparent to the first near-infrared IR1 and the second near-infrared IR2. It is effective when the package 11 is configured by sticking the seal 14.

  Moreover, in the near-infrared inspection apparatus 1, the determination part 6 determines whether the bitten thing F exists in the sealing part 11a of the package 11 based on the difference image IM3. With this configuration, the article 10 in which the bite F exists in the sealing portion 11a of the package 11 can be automatically discharged from the production line.

  Moreover, in the near-infrared inspection apparatus 1, the determination part 6 extracts the area | region corresponding to the sealing part 11a in the difference image IM3, and the part which has a predetermined luminance value difference exists in the area | region corresponding to the sealing part 11a. In this case, it is determined that the bite F exists in the sealing portion 11a. With this configuration, it is possible to easily and accurately determine whether or not the bite F exists in the sealing portion 11a of the package 11.

  Moreover, in the near-infrared inspection apparatus 1, the light irradiation part 3 irradiates 1st near-infrared IR1 and 2nd near-infrared IR2 by the period T alternately, and the imaging part 4 follows the direction corresponding to the conveyance width direction B. Imaging is performed at a period T for each pixel row arranged in a row. With this configuration, it is possible to capture the first image IM1 and the second image IM2 with one imaging unit 4. Therefore, for example, when the first image IM1 and the second image IM2 are imaged by the two imaging units 4, sensitivity correction and alignment between the first image IM1 and the second image IM2 are necessary. In this configuration, such processing is not necessary. For example, when the first image IM1 and the second image IM2 are captured by the two imaging units 4, the second imaging unit 4 that captures the first image IM1 of the article 10 by the first near-infrared IR1 is included in the second imaging unit 4. A filter that cuts the near-infrared IR2 is required, and the other imaging unit 4 that captures the second image IM2 of the article 10 by the second near-infrared IR2 needs a filter that cuts the first near-infrared IR1. In the configuration, such a filter is also unnecessary.

  Further, in the near-infrared inspection apparatus 1, the image generation unit 5 complements regions corresponding to the missing pixel columns in each of the first image IM1 and the second image IM2, and generates a difference image IM3. . With this configuration, the difference image IM3 can be generated easily and accurately.

  Further, in the near-infrared inspection apparatus 1, the first wavelength of the first near-infrared IR1 is longer than the wavelength obtained by multiplying the second wavelength of the second near-infrared IR2 by 0.8, and the second wavelength of the second near-infrared IR2 Shorter than the wavelength multiplied by 1.2. With this configuration, the influence of the aberration in the imaging unit 4 can be reduced while ensuring a sufficient difference between the absorption rate of the first near-infrared IR1 by the biting object F and the absorption rate of the second near-infrared IR2 by the biting object F. The difference image IM3 can be generated with high accuracy.

  In the near-infrared inspection apparatus 1, the transport unit 2 transports the article 10. With this configuration, the imaging of the first image IM1 and the second image IM2 and the conveyance of the article 10 can be appropriately interlocked.

  The present invention is not limited to the embodiment described above. For example, the near-infrared inspection apparatus 1 may be configured as shown in FIG. In the near-infrared inspection apparatus 1 shown in FIG. 7, the light irradiation unit 3 and the imaging unit 4 face each other through the gap between the belt conveyors 21 and 22 that constitute the transport unit 2. That is, the light irradiation unit 3 and the imaging unit 4 are arranged on one side and the other side with respect to the conveyance surface 2a of the conveyance unit 2, respectively. In the near-infrared inspection apparatus 1 shown in FIG. 7, the imaging unit 4 captures the first transmitted light image of the article 10 by the first near-infrared IR1 as the first image IM1, and the second near-infrared IR2 as the second image IM2. A second transmitted light image of the article 10 is taken. More specifically, in the near-infrared inspection apparatus 1 shown in FIG. 7, the sealing material 11a is configured by superimposing a transparent material on each of the first near-infrared IR1 and the second near-infrared IR2. If it is, the imaging unit 4 detects the first near-infrared IR1 and the second near-infrared IR2 that have passed through the sealing unit 11a. In this configuration, for example, the package 11 is configured by a film packaging material (transparent material) 15 (including a printed region) that is transparent to each of the first near-infrared IR1 and the second near-infrared IR2. It is effective in such a case.

  Moreover, the near-infrared inspection apparatus 1 may be configured as shown in FIG. In the near-infrared inspection apparatus 1 shown in FIG. 8, the first light source 31 of the light irradiation unit 3 is arranged on one side of the imaging unit 4 in the transport width direction B, and the second light source 32 of the light irradiation unit 3 is It is arranged on the other side of the imaging unit 4 in the conveyance width direction B. In the near-infrared inspection apparatus 1 shown in FIG. 8, among the line sensors 40 of the imaging unit 4, a plurality of PDs (first imaging regions) 41 located on one side of the center in the transport width direction B are irradiated with light. The second near-infrared IR2 emitted from the second light source 32 of the unit 3 is detected, and among the line sensors 40 of the imaging unit 4, a plurality of positions located on the other side of the center of the line sensor 40 in the transport width direction B The PD (second imaging region) 42 detects the first near-infrared IR1 emitted from the first light source 31 of the light irradiation unit 3. According to this structure, the 1st light source 31 and the 2nd light source 32 can be lighted simultaneously, and the 1st image IM1 and the 2nd image IM2 can be imaged simultaneously. Furthermore, when the difference image IM3 is generated, alignment between the first image IM1 and the second image IM2 is facilitated.

  In the near-infrared inspection apparatus 1 shown in FIG. 8, the light irradiation unit 3 includes lenses 33 and 34 in addition to the first light source 31 and the second light source 32, and the imaging unit 4 includes the line sensor 40. In addition, filters 43 and 44 and lenses 45 and 46 are provided. The lens 33 expands the first near-infrared IR1 emitted from the first light source 31 so that the article 10 being conveyed is efficiently irradiated with the first near-infrared IR1. The lens 34 expands the second near-infrared IR2 emitted from the second light source 32 so that the second near-infrared IR2 is efficiently irradiated onto the article 10 being conveyed. The lens 45 condenses the second near-infrared IR2 reflected by the conveyed article 10 so that the second near-infrared IR2 efficiently enters the plurality of PDs 41. The filter 43 passes the second near-infrared IR2 between the lens 45 and the plurality of PDs 41 and cuts the first near-infrared IR1. The lens 46 condenses the first near-infrared IR1 reflected by the conveyed article 10 so that the first near-infrared IR1 efficiently enters the plurality of PDs 42. The filter 44 passes the first near-infrared IR1 between the lens 46 and the plurality of PDs 42, and cuts the second near-infrared IR2.

  Moreover, the light irradiation part 3 may be comprised so that 3 or more types of near infrared rays may be irradiated, and the imaging part 4 is comprised so that the image of the articles | goods by each of 3 or more types of near infrared rays may be imaged. It may be. In that case, a plurality of types of biting objects F can be detected by generating difference images with different combinations. Further, when the package 11 is printed, by irradiating a near-infrared ray having a wavelength that is easily absorbed by the print region, taking an image of the article by the near-infrared ray, and correcting the difference image, It is possible to generate a difference image in which the print area is emphasized or excluded.

  Further, the imaging unit 4 may perform imaging with a period T for each of a plurality of pixel columns arranged along a direction corresponding to the conveyance width direction B. The imaging unit 4 may be configured with a plurality of cameras. For example, when the imaging unit 4 is configured by two cameras, the first near-infrared IR1 and the second near-infrared IR2 reflected by the article 10 are divided and the first image IM1 is captured by one camera. The second camera IM2 is picked up by the other camera. Alternatively, the first near-infrared IR1 and the second near-infrared IR2 transmitted through the article 10 are separated, and the first image IM1 is captured by one camera, and the second image IM2 is captured by the other camera. In this case, it is not necessary for the light irradiation unit 3 to alternately irradiate the first near-infrared IR1 and the second near-infrared IR2 with the period T.

  Further, the near-infrared inspection apparatus 1 may be configured to be installed on an existing conveyance conveyor without including the conveyance unit 2. Moreover, the structure which displays the test result based on the difference image IM3 on the display may be sufficient as the near-infrared test | inspection apparatus 1 is not provided with the determination part 6. FIG. In that case, the image of the article 10 may be displayed in a state where the bitten matter F is emphasized, such as by surrounding the bitten matter F with a square.

  Moreover, the wavelength of the near infrared ray used in the near infrared ray inspection apparatus 1 can be appropriately selected according to the type of the biting object F. For example, when the bite F contains water such as rice, the first wavelength of the first near infrared IR1 is 1450 nm and the second wavelength of the second near infrared IR2 is 1300 nm. When F contains alcohol, or when the bitten F contains oil, the near-infrared wavelength used in the near-infrared inspection apparatus 1 can be selected as appropriate. As for the wavelength of the first near infrared ray, about 1900 nm can be selected for water, about 1700 nm can be selected for oil, and about 2100 nm can be selected for alcohol. An appropriate wavelength of the first near infrared ray is determined in consideration of an absorption band that varies depending on the chemical formula (group) of the substance included in the bitten matter F, the temperature of the bitten matter F, and the like. In addition, near infrared means light with a wavelength of 750 nm to 2500 nm.

  Further, when generating the difference image IM3, the image generation unit 5 does not have to complement regions corresponding to the missing pixel columns in each of the first image IM1 and the second image IM2. Such complementation by the image generation unit 5 can be made unnecessary, for example, by shortening the imaging period T in the imaging unit 4.

  DESCRIPTION OF SYMBOLS 1 ... Near-infrared inspection apparatus, 2 ... Conveyance part, 3 ... Light irradiation part, 4 ... Imaging part, 5 ... Image generation part, 6 ... Determination part, 10 ... Article, 11 ... Package, 11a ... Sealing part, 12 ... Contents: A ... Conveying direction, B ... Conveying width direction, F ... Clogged object, IR1 ... First near infrared ray, IR2 ... Second near infrared ray, IM1 ... First image, IM2 ... Second image, IM3 ... Differential image .

Claims (11)

A near-infrared inspection apparatus for inspecting whether or not there is a biting substance in the sealing portion of the package in an article having a package and contents,
A light irradiation unit for irradiating the conveyed article with a first near-infrared ray having a first wavelength and a second near-infrared ray having a second wavelength;
An imaging unit that captures a first image of the article by the first near infrared ray and a second image of the article by the second near infrared ray;
An image generation unit that generates a difference image between the first image and the second image;
The near-infrared inspection apparatus, wherein the absorption rate of the first near infrared ray by the biting object is higher than the absorption rate of the second near infrared ray by the biting object.   The imaging unit captures a first reflected light image of the article by the first near infrared as the first image, and captures a second reflected light image of the article by the second near infrared as the second image. The near-infrared inspection apparatus according to claim 1. A first material that is transparent to each of the first near infrared ray and the second near infrared ray and a second material that is opaque to each of the first near infrared ray and the second near infrared ray are superimposed. In the case where the sealing portion is configured,
The light irradiation unit irradiates the first near infrared ray and the second near infrared ray to the sealing portion from the first material side,
The near-infrared inspection apparatus according to claim 2, wherein the imaging unit detects the first near-infrared light and the second near-infrared light that are transmitted through the first material and reflected by the second material.   The imaging unit captures a first transmitted light image of the article by the first near infrared as the first image, and captures a second transmitted light image of the article by the second near infrared as the second image. The near-infrared inspection apparatus according to claim 1. In the case where the sealing part is configured by overlapping a transparent material for each of the first near infrared ray and the second near infrared ray,
The near-infrared inspection apparatus according to claim 4, wherein the imaging unit detects the first near-infrared ray and the second near-infrared ray that have passed through the sealing portion.   The near-infrared inspection apparatus according to any one of claims 1 to 5, further comprising a determination unit that determines whether or not the bite exists in the sealing unit based on the difference image.   The determination unit extracts an area corresponding to the sealing portion in the difference image, and determines that the biting object is present in the sealing portion when a portion having a predetermined luminance value difference exists in the region. The near-infrared inspection apparatus according to claim 6. The light irradiation unit alternately irradiates the first near infrared ray and the second near infrared ray at a predetermined cycle,
The near-infrared inspection apparatus according to any one of claims 1 to 7, wherein the imaging unit performs imaging at the predetermined cycle for each of at least one pixel row arranged in a direction corresponding to a conveyance width direction. .   The near-infrared ray according to claim 8, wherein the image generation unit complements regions corresponding to missing pixel columns in each of the first image and the second image, and generates the difference image. Inspection device.   10. The first wavelength according to claim 1, wherein the first wavelength is longer than a wavelength obtained by multiplying the second wavelength by 0.8 and shorter than a wavelength obtained by multiplying the second wavelength by 1.2. Near infrared inspection equipment.   The near-infrared inspection apparatus as described in any one of Claims 1-10 further provided with the conveyance part which conveys the said article | item.