JP6964305B2 - Package content inspection method and inspection equipment - Google Patents

Description

The present invention relates to a method for inspecting the contents of a packaged product and an inspection device, and is particularly suitable for inspecting the state of the contents enclosed in a packaging material that does not transmit light (visible light or infrared rays).

As a technology for inspecting the contents of a packaged product, that is, the contents (food, etc.) stored in the packaging material, the packaged product is irradiated with visible light or infrared rays, and the reflected light from the contents is received to receive the contents. Techniques for assessing the condition are known. Further, Patent Document 1 discloses a technique for inspecting whether or not an abnormality in the stored state of the contents is present (that is, whether or not a piece of the contents is bitten as a foreign substance in the seal portion of the package). .. In the same document, a lighting unit and a camera are arranged across the package, and while the image transmitted through the package is acquired by the camera, foreign matter on the seal unit is based on the binarized image of the image and the background image. A technique for determining the presence or absence of biting is described.

Further, Patent Document 2 discloses a food X-ray foreign matter inspection device.

Further, Patent Document 3 describes a method of acquiring a temperature distribution generated by simultaneously adding different thermal elements of heating and cooling to an inspection object with an infrared imaging device and identifying the presence or absence of defects and a site based on the temperature distribution. Is disclosed.

In addition, Patent Document 4 discloses a technique for detecting an internal defect using a phase image.

Japanese Unexamined Patent Publication No. 2013-7597 JP-A-2009-229100 Japanese Unexamined Patent Publication No. 2008-216159 Japanese Unexamined Patent Publication No. 2017-369777

http://www.avio.co.jp/products/infrared/lineup/ir-thermo/r300sr-ss/

However, conventional content inspection devices or methods for packaged products, including those disclosed in Patent Document 1, utilize light transmission, and it is premised that the packaging material can transmit the light to be used. Become. On the other hand, packaging materials for storing foods and the like include those called aluminum bags and those with dark-colored printing, which do not transmit visible light and infrared rays, and are therefore referred to in Patent Document 1 and the like. The contents cannot be inspected by the disclosed technology. On the other hand, in the X-ray foreign matter inspection device for foods disclosed in Patent Document 2, although it is possible to inspect the contents, strict control, operation and maintenance are required in order to use X-rays. ..

Further, in the technique disclosed in Patent Document 3, heating or heating and cooling of only the surface of the object are performed at the same time, but in this case, the temperature change is limited to the vicinity of the surface of the object, so that the object is subject. It becomes difficult to accurately detect defects and foreign substances inside an object. Further, the technique disclosed in Patent Document 4 requires repeated heating at a constant frequency and extraction processing of an image signal synchronized with the frequency, which makes the device configuration complicated and expensive. Moreover, the techniques disclosed in Patent Documents 3 and 4 are not suitable for rapidly inspecting the contents of packaged products containing foods and the like, which are generally mass-produced.

On the other hand, the present inventors have also considered applying a passive thermography technique as disclosed in Non-Patent Document 1, but this technique observes the heat conduction state appearing on the surface of the object to be photographed by the infrared camera. Therefore, the state of the contents existing in non-contact on the back side of the object to be photographed cannot be observed.

The present invention has been made in view of the problems of the background technology as described above.

That is, an object of the present invention is to provide a technique capable of inspecting the state of the contents stored in a packaging material that does not transmit infrared rays.

Another object of the present invention is to contribute to the construction of a system for inspecting the contents of packaged products, which is simple and easy to manage, operate and maintain.

A further object of the present invention is to provide a technique that enables rapid inspection of the contents and also enables inspection of the contents in a state where they are not in contact with the packaging material.

Therefore, the present invention is a method for inspecting the contents of a packaged product in which the contents are stored in a packaging material, wherein the packaged product at a uniform first temperature has a second temperature different from the first temperature. The contents are inspected based on the distribution of the surface temperature of the packaging material after being exposed to the above conditions.

Further, the present invention is an apparatus for inspecting the contents of a packaged product in which the contents are sealed in a packaging material, wherein the packaged product at a uniform first temperature has a second temperature different from the first temperature. It is characterized by including means for exposing the contents to conditions and subsequent means for inspecting the contents based on the distribution of the surface temperature of the packaging material.

According to the present invention, the contents are inspected based on the temperature distribution caused by the conduction heat and the radiant heat from the contents that appear on the surface of the packaging material after being exposed to the second temperature. That is, since the configuration is not premised on the transmission of infrared rays, it is possible to inspect the contents even if the packaging material does not transmit visible light or infrared rays. In addition, the basic configuration is only to acquire infrared images from packaged products exposed to two temperatures, high and low, and does not require a light source such as visible light or infrared light or an X-ray source, so an inspection system is performed. The configuration of the is simple, and its management, operation and maintenance are easy. Furthermore, since the contents can be inspected in a series of steps, quick inspection processing is possible, and the temperature change due to heat radiation also appears on the surface of the packaging material, so that the contents are not in contact with the packaging material. Even if there is, the inspection becomes possible.

It is a schematic diagram which shows an example of the content inspection apparatus of a package article to which the basic concept of this invention is applied. It is a figure for demonstrating the inspection principle of the contents by the structure of FIG. It is a figure which shows one application example of this invention, (a) shows the image of the package obtained through the process according to this invention, and (b) shows the stored state of the contents of a package. It is explanatory drawing for demonstrating another application example of this invention.

Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic view showing an example of a content inspection device for a packaged product to which the basic concept of the present invention is applied.

The package product 1 is formed by storing a plurality of contents 13 in the packaging material 11 as shown by breaking a part thereof. As the packaging material 11, a laminated bag (hereinafter referred to as an aluminum bag) using, for example, an aluminum foil that does not transmit visible light or infrared rays may be used. The content 13 can take various forms and may be, for example, a small confectionery, but in order to follow the principle of the present invention, it is strongly desirable that the content 13 has a higher specific heat or heat capacity than the packaging material 11.

It is assumed that the package product 1 is initially exposed to the environmental temperature which is the first temperature T1, and therefore the packaging material 11 and the content 13 exhibit the same temperature T1. Here, the environmental temperature may be, for example, the environmental temperature of the storage location of the manufactured package product 1. The package product 1 is conveyed toward the inspection device side by, for example, a belt conveyor BC.

A low temperature chamber 20 maintained at a second temperature T2 whose internal temperature is lower than the first temperature T1 is arranged in the transport path, and by passing through the low temperature chamber 20, the packaging material 11 starts from the first temperature T1. It is exposed to the second temperature T2. That is, in the present embodiment, the low temperature chamber 20 is a means for exposing the packaging material 11 to a second temperature lower than the first temperature. The low temperature chamber 20 is preferably configured so that the cold air does not directly hit the surface of the packaging material 11, and for example, a Perche element or the like may be arranged. What is important here is that the transit time and the temperature T2 are set so that the influence of the low temperature extends only to the packaging material 11. An infrared image of the package product 1 that has passed through the low temperature chamber 20 is taken by the infrared camera 30, and the content 13 is inspected by the inspection unit 40 based on the temperature distribution that appears in the image.

The inspection principle of this embodiment will be described with reference to FIG. The contents 13 stored in the packaging material 11 include those that are in contact with the side surface 11a of the packaging material to be photographed by the infrared camera 30 (indicated by reference numeral C1) and those that are not in contact with the side surface 11a (indicated by reference numeral C2). Can exist. Since the packaging material 11 which is an aluminum bag has a relatively small specific heat or heat capacity and is generally small in thickness of about several tens of μm, it responds sensitively to temperature changes, and in the process of passing through the low temperature chamber 20, it easily reaches a second temperature. The temperature drops to close to T2. On the other hand, the content 13 passes through the low temperature chamber 20 while maintaining substantially the first temperature T1 without being substantially cooled.

Then, heat is transferred to the side surface 11a of the packaging material by conduction from the content C1 in contact with the side surface 11a and by radiation from the content C2 not in contact with the side surface 11a, and the temperature rises, and the content exists directly underneath. A temperature difference will occur with the portion of the side surface 11a of the packaging material that is not used. That is, on the surface of the side surface 11a of the packaging material, the temperature is different between the region Hc in which the temperature rises due to the conduction heat, the region Hr in which the temperature rises due to the radiant heat, and the region Hn in which the contents do not exist directly below. Moreover, a distribution in which the temperature decreases appears in this order. Since the illustrated content exemplifies a lemon-shaped content, radiant heat is transmitted from the non-contact portion of the content C1 with respect to the side surface 11a of the packaging material.

The state of the content 13 can be known by photographing the surface of the side surface 11a of the packaging material exhibiting such a temperature distribution with an infrared camera, acquiring an image of the temperature distribution, and analyzing the temperature distribution with the inspection unit 40. ..

FIG. 3A shows an infrared image obtained by the present inventors by an experiment. This is a photograph of a packaged product in which a lemon-shaped confectionery "gummy" is stored in a packaging material 11 which is an aluminum bag. The lower part B is distributed. Therefore, these portions R, Y, and B correspond to the region Hc in which the temperature rise is caused by the conduction heat, the region Hr in which the temperature rise is caused by the radiant heat, and other regions, respectively. The present inventors have confirmed that if the difference between the first temperature T1 and the second temperature T2 is about 10 ° C., it is sufficient to obtain an image as shown in FIG. 3A.

From the image thus obtained, at least one of the shape, size, number, and the like of the content 13 can be inspected. In particular, if contour extraction is performed as shown in FIG. 3B, the shape can be easily recognized, and it can be used for determining whether or not the content 13 is defective. Alternatively, by determining the position of the contents with respect to the packaging material 11, the sealing property of the sealing portion of the packaging material 11 is hindered, and the contents that may cause putrefaction are bitten. It is also possible to inspect whether or not it is present. That is, for example, as shown in FIG. 4, if the position of the packaging material 3 with respect to the seal portion 4 is confirmed with respect to the content 5 such as smoked product that is torn linearly, the presence or absence of the content 6 that is bitten into the seal portion 4 can be determined. Can be inspected.

This embodiment has the advantage that even if the contents are stored in a packaging material that does not transmit visible light or infrared rays, the state of the contents can be inspected without using X-rays. Have. This is because the inspection does not assume the transmission of light. In addition, the basic configuration is only to acquire infrared images from packaged products exposed to two temperatures, high and low, and does not require a light source such as visible light or infrared light or an X-ray source, so an inspection system is performed. The configuration of the is simple, and its management, operation and maintenance are easy. Further, as shown in FIG. 1, since the inspection of the content 13 can be carried out in a series of flows, a quick inspection process becomes possible. In addition, as shown in FIGS. 2 and 3A, a temperature change due to heat radiation also appears on the packaging material surface 11a, so that even if there is a content C2 that is not in contact with the packaging material 11, it can be found. It becomes possible to carry out an inspection.

(others)
In the above-described embodiment, the aluminum bag is exemplified as the packaging material 11, and the food is exemplified as the content 13, but the present invention is not limited to these examples. The material of the packaging material is not particularly limited, but the present invention can be effectively applied to a packaging material that does not transmit infrared rays, and therefore, for example, a colored plastic material may be used. Further, the content may be any material having a heat capacity or specific heat larger than that of the packaging material, and may be not limited to foods but may be tablets or the like.

Further, the system configuration shown in FIG. 1 is also merely an example, and the packaged product is continuously conveyed (transferred) by one belt conveyor from the region exhibiting the first temperature T1 to the region where an infrared image is acquired. It is not limited to. For example, some transfers may be performed manually or by manipulating a robot arm. Further, the infrared camera also has a line sensor-like form in addition to a camera that captures the entire packaged product at a time, and relatively scans the surface of the side surface 11a of the packaging material as the packaged product moves. There may be.

In addition, in the above-described embodiment, the first temperature T1 is set to the environmental temperature (environmental temperature of the storage location), and the second temperature T2 is provided by the low temperature chamber 20. However, in the configuration of the above embodiment, the first temperature T1 which is relatively high temperature and the second temperature T2 which is relatively low temperature (for example, about 10 ° C. lower) may be provided. It is also possible that the temperature T1 is provided by the high temperature chamber and the second temperature T2 is the ambient temperature (the ambient temperature of the inspection site). Alternatively, a constant temperature chamber that provides a first temperature T1 and a second temperature T2 may be provided, respectively. On the contrary, if the temperature of the manufacturing site of the packaged product 1 is sufficiently higher than the temperature of the external environment and the temperature of the packaged product 1 is uniform at the time of manufacturing, the packaged product 1 is used. The inspection may be performed after being brought out to the external environment, and in this case, a means for positively providing the first temperature T1 and the second temperature T2 may be unnecessary. Further, as long as the temperature distribution caused by the conduction heat and radiant heat from the contents appearing on the surface of the packaging material after being exposed to the second temperature can be effectively observed, the relationship of T1 <T2 may be satisfied.

1 Package product 11 Packaging material 13, C1, C2 Contents 20 Low temperature chamber 30 Infrared camera 40 Inspection unit

Claims (8)

It is a method of inspecting the contents of a packaged product in which the contents are stored in a packaging material.
The packaging material is made of a material having a heat capacity smaller than that of the contents.
After exposing the packaged product at a uniform first temperature to a second temperature condition lower than the first temperature to change the packaging material to a temperature lower than the contents.
Obtaining the surface temperature distribution of the packaging material,
The temperature change region of the surface of the packaging material that is affected by the amount of heat of the contents that are in contact with the packaging material, and the surface of the packaging material that is affected by the amount of heat of the contents that are not in contact with the packaging material. A method for inspecting the contents of a packaged product, which comprises identifying the temperature change region and inspecting the state of the contents. The content inspection of the packaged product according to claim 1, wherein at least the change in the surface temperature of the packaging material from the second temperature to the first temperature is acquired and the content is inspected. Method. The temperature change of the packaging material, which is affected by the amount of heat of the content that is not in contact with the packaging material, is due to the radiant heat from the content.
The claim is characterized in that the temperature change of the packaging material, which is affected by the amount of heat of the content in contact with the packaging material, is caused by the conduction heat from the content. The method for inspecting the contents of a packaged product according to 1 or 2. The method for inspecting the contents of a packaged product according to any one of claims 1 to 3, wherein the distribution of the surface temperature of the packaging material is acquired by using an infrared camera. The method for inspecting the contents of a packaged product according to any one of claims 1 to 4, wherein the first temperature is an environmental temperature. The method for inspecting the contents of a packaged product according to any one of claims 1 to 5, wherein the packaging material is made of a material that does not transmit infrared rays. Shape before Symbol contents, size, number, and package according to any one of claims 1 to 5 at least one of the storage position, characterized in that the target of inspection of the contents with respect to the packaging material Product content inspection method. It is a content inspection device for packaged products in which the contents are enclosed in a packaging material.
The contents include those in contact with the packaging material and those in contact with the packaging material.
The packaging material is made of a material having a heat capacity smaller than that of the contents.
Means for exposing the packaged product at a uniform first temperature to a second temperature condition lower than the first temperature to change the packaging material to a temperature lower than the contents.
An infrared camera that acquires the surface temperature distribution of the packaging material,
A temperature change region on the surface of the packaging material that is affected by the amount of heat of the content that comes into contact with the packaging material after being exposed to the second temperature, and the amount of heat of the content that is not in contact with the packaging material. A means for identifying the temperature change region on the surface of the packaging material affected by the above and inspecting the state of the contents.
A device for inspecting the contents of packaged products, which is characterized by being equipped with.

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