JP7397544B1 - Plastic determination device - Google Patents

Abstract

An object of the present invention is to appropriately determine a material to be determined. SOLUTION: In a PET bottle determination device 10, a light source unit 20 irradiates a determination target 14 with near-infrared rays, and a light receiving unit 22 receives the near-infrared rays partially absorbed by the determination target 14. Then, based on the near-infrared rays received by the light receiving unit 22, it is determined whether the determination target 14 is a plastic bottle 16. Here, the light receiving section 22 is provided with a diffuser plate 22A and a pipe 22B, and the diffuser plate 22A diffuses the near infrared rays received by the light receiving section 22, and the pipe 22B diffusely reflects the near infrared rays diffused by the diffuser plate 22A. let Therefore, the amount of near-infrared rays that the light receiving section 22 receives can be increased, and the material of the determination target 14 can be appropriately determined. [Selection diagram] Figure 1

Description

TECHNICAL FIELD The present invention relates to a plastic determination device that determines the material of a plastic determination target.

In the plastic determination device described in Patent Document 1 below, a light source irradiates the plastic and partially absorbed light is received by a spectral sensor, and a determination unit determines the material of the plastic based on the light received by the spectral sensor. do.

Here, it is preferable that such a plastic determining device be able to appropriately determine the material of the plastic.

Patent No. 6947447

The present invention takes the above-mentioned facts into consideration and aims to provide a plastic determining device that can appropriately determine the material of the target material.

A plastic determination device according to a first aspect of the present invention includes: an irradiation unit that irradiates light to a plastic determination target; and a light reception unit that receives light irradiated from the irradiation unit and partially absorbed by the determination target. , a diffusing section provided in the light receiving section to diffuse the light received by the light receiving section; a diffuse reflection section provided in the light receiving section to diffusely reflect the light diffused by the diffusing section; A determination mechanism that determines the material of the determination target based on light.

A plastics determination device according to a second aspect of the present invention includes: a conveyance mechanism that conveys a plastic determination target; an irradiation unit that irradiates the determination target with light in an oblique direction with respect to the conveyance direction of the determination target by the conveyance mechanism; The apparatus includes a light receiving section that receives light emitted from an irradiation section and partially absorbed by a determination target, and a determination mechanism that determines the material of the determination target based on the light received by the light receiving section.

In the plastic determining device according to the third aspect of the present invention, in the plastic determining device according to the first or second aspect of the present invention, the light receiving section receives the light transmitted through the target to be determined.

A plastic determining device according to a fourth aspect of the present invention is the plastic determining device according to any one of the first to third aspects of the present invention, in which the determining mechanism determines the absorbance of the liquid to be determined.

In the plastic determination device according to the first aspect of the present invention, the irradiation unit irradiates light onto the plastic determination target, and the light receiving unit receives light irradiated from the irradiation unit and partially absorbed by the determination target. . Furthermore, the determination mechanism determines the material to be determined based on the light received by the light receiving section.

Here, the light receiving section is provided with a diffusing section and a diffused reflection section, and the diffusing section diffuses the light received by the light receiving section, and the diffused reflecting section diffusely reflects the light diffused by the diffusing section. Therefore, the light receiving section can receive more light, and the material to be determined can be appropriately determined.

In the plastic determination device according to the second aspect of the present invention, the conveyance mechanism conveys the plastic determination target. Further, the irradiation unit irradiates the determination target with light, and the light receiving unit receives the light irradiated from the irradiation unit and partially absorbed by the determination target. Furthermore, the determination mechanism determines the material to be determined based on the light received by the light receiving section.

Here, the irradiation unit irradiates light in a direction oblique to the direction in which the determination target is transported by the transport mechanism. Therefore, the amount of light irradiated from the irradiation unit onto the determination target can be increased, and the material of the determination target can be appropriately determined.

In the plastic determination device according to the third aspect of the present invention, the light receiving section receives the light transmitted through the determination target. Therefore, more light can be absorbed by the object to be determined, and the material of the object to be determined can be appropriately determined.

In the plastic determining device according to the fourth aspect of the present invention, the determining mechanism determines the absorbance of the liquid to be determined. Therefore, it is possible to determine the presence of liquid in the determination target.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view from above showing a PET bottle determining device according to a first embodiment of the present invention. FIG. 2 is a block diagram showing the hardware configuration of a spectroscopic analyzer of the PET bottle determination device according to the first embodiment of the present invention. FIG. 2 is a block diagram showing an example of the functional configuration of a spectroscopic analyzer of the PET bottle determination device according to the first embodiment of the present invention. It is a flow chart showing plastic bottle judgment processing in a plastic bottle judgment device concerning a 1st embodiment of the present invention. It is a flow chart showing judgment processing in a PET bottle judgment device concerning a 1st embodiment of the present invention. It is a top view showing the plastics judgment device concerning a 2nd embodiment of the present invention seen from above.

[First embodiment]
FIG. 1 shows a top plan view of a plastic bottle determining device 10 as a plastic determining device according to a first embodiment of the present invention.

As shown in FIG. 1, the PET bottle determination device 10 according to the present embodiment is provided with a conveyor 12 as a conveyance mechanism, and an endless belt 12A is provided around the conveyor 12. ing. The upper part of the belt 12A is arranged perpendicularly to the up-down direction and extends in the direction perpendicular to the up-down direction, and when the conveyor 12 is operated, the upper part of the belt 12A is arranged in the extending direction. It is moved in the transport direction A.

A determination object 14, which is a beverage container, is supplied to the belt 12A from above. When the conveyor 12 is operated, the determination target 14 is placed on the belt 12A in a state where the longitudinal direction (vertical direction) of the determination target 14 is approximately parallel to the extending direction (conveying direction A) of the upper portion of the belt 12A. The pieces are conveyed one by one in the conveying direction A at intervals. The determination target 14 includes a PET bottle 16 made of plastic PET (polyethylene terephthalate), and the PET bottle 16 includes an empty PET bottle that does not contain any residual liquid (content, liquid), and an empty PET bottle that contains residual liquid. Contains plastic bottles to accommodate.

An NIR sensor 18 (near infrared sensor) as a measuring mechanism is installed around the conveyor 12.

The NIR sensor 18 is provided with a light source section 20 as an irradiation section, and the light source section 20 is arranged on one side above the belt 12A of the conveyor 12 and irradiates near-infrared rays from a circular light emitting surface 20A. do. The light emitting surface 20A of the light source section 20 is arranged parallel to the transport direction A and the vertical direction, and the light source section 20 emits near infrared rays from the light emitting surface 20A in a direction perpendicular to the light emitting surface 20A. For this reason, near-infrared rays are irradiated from the light source section 20 to the determination target 14 conveyed by the conveyor 12.

The NIR sensor 18 is provided with a light receiving section 22, and the light receiving section 22 is arranged on the other side above the belt 12A. 14), including near-infrared rays that are partially absorbed by the rays. The light receiving section 22 is provided with a disc-shaped diffusion plate 22A as a diffusion section, and the diffusion plate 22A is coaxially opposed to the light emitting surface 20A of the light source section 20. The diffusion plate 22A is made of glass, and the diffusion plate 22A diffuses and transmits the near-infrared rays emitted by the light source section 20. A bottomed cylindrical pipe 22B as a diffused reflection section is fixed on the opposite side of the diffuser plate 22A from the light source section 20. The pipe 22B is arranged coaxially with the diffuser plate 22A, and has a diffuser inside. It is closed by plate 22A. The pipe 22B is made of metal, and the inner surface of the pipe 22B diffuses and uniformizes the near infrared rays diffused and transmitted by the diffusion plate 22A. One end of an optical fiber 24 is coaxially connected to the bottom wall of the pipe 22B, and the near-infrared rays within the pipe 22B are received by the light receiving surface of the one end of the optical fiber 24. Further, the diameter of the diffuser plate 22A and the inner diameter of the pipe 22B are made sufficiently larger than the light receiving surface of the optical fiber 24.

A spectroscopic analyzer 26 as a determination mechanism is connected to the other end of the optical fiber 24, and the spectroscopic analyzer 26 receives near infrared light (judgment target 14) received by the light receiving section 22 via the optical fiber 24. (including near-infrared rays that are partially absorbed) is input.

As shown in FIG. 2, the spectrometer 26 includes a CPU 28 (Central Processing Unit), a ROM 30 (Read Only Memory), a RAM 32 (Random Access Memory), a storage 34, and a user interface 36. Each component is communicably connected to each other via a bus 38.

The CPU 28 is a central processing unit that executes various programs and controls various parts. That is, the CPU 28 reads the program from the ROM 30 or the storage 34 and executes the program using the RAM 32 as a work area. The CPU 28 controls each of the above components and performs various arithmetic operations according to programs recorded in the ROM 30 or the storage 34. In this embodiment, the ROM 30 or the storage 34 stores a PET bottle determination program for determining the material of the determination target 14 and the like.

The ROM 30 stores various programs and various data. The RAM 32 temporarily stores programs or data as a work area. The storage 34 is configured with an HDD (Hard Disk Drive) or an SSD (Solid State Drive), and stores various programs and various data.

The user interface 36 is an interface used when a user uses the spectroscopic analyzer 26. The user interface 36 includes, for example, at least one of a liquid crystal display equipped with a touch panel that allows touch operations by the user, a voice input reception unit that receives voice input from the user, and a button that the user can press. .

When executing the above-mentioned PET bottle determination program, the spectroscopic analyzer 26 uses the above-mentioned hardware resources to realize various functions. The functional configuration realized by the spectroscopic analyzer 26 will be explained.

As shown in FIG. 3, the spectroscopic analyzer 26 has a storage section 40 (library) and a determination section 42 as functional components. Each functional configuration is realized by the CPU 28 reading out a plastic bottle determination program stored in the ROM 30 or the storage 34, loading it into the RAM 32, and executing it.

The storage unit 40 stores in advance the following library data lib, which is a spectrum waveform of near-infrared rays partially absorbed by PET, which is plastic. Further, the storage unit 40 stores in advance a dark value D and a reference value R, which are constants when determining the absorbance abs of the determination target 14 described below.

The storage unit 40 also stores a threshold value PB of the PET index described below for determining the material of the determination target 14, and a threshold value WT of the residual liquid index described below for determining whether residual liquid is contained in the determination target 14. are stored in advance.

The determining unit 42 determines the material of the target 14 by near-infrared spectroscopy based on the spectrum of near-infrared rays partially absorbed by the target 14 measured by the NIR sensor 18 .

Next, the operation of this embodiment will be explained.

In the PET bottle determination device 10 having the above configuration, the conveyor 12 conveys the determination target 14 in the conveyance direction A using the upper portion of the belt 12A. Further, in the NIR sensor 18 , a light source section 20 irradiates near-infrared rays onto the object 14 to be determined, and a light receiving section 22 receives the near-infrared rays that has passed through the object 14 . The near-infrared rays partially absorbed by the determination target 14 are input to the spectroscopic analyzer 26 via the optical fiber 24.

In the spectroscopic analyzer 26, a plastic bottle determination process (see FIG. 4) is performed. The plastic bottle determination process is performed by the CPU 28 reading a plastic bottle determination program from the ROM 30 or the storage 34, loading it into the RAM 32, and executing it.

In the PET bottle determination process, in step 100, the PET index threshold PB and the residual liquid index threshold WT are input into the storage unit 40 of the spectroscopic analyzer 26.

Then, in step 102, each time the NIR sensor 18 detects passage of the determination target 14 between the light source section 20 and the light receiving section 22 (every time the amount of near-infrared light received by the light receiving section 22 is decreased by the determination target 14). Then, a determination process (see FIG. 5) is performed.

In the determination process, in step 104, the measurement value MX of the NIR sensor 18 for the determination target 14 (near infrared rays partially absorbed by the determination target 14) is received.

Next, in step 106, the absorbance abs of the determination target 14 is determined. When the dark value is D and the reference value is R, abs=log ₁₀ ((RD)/(MX-D)).

Next, in step 108, the absorbance abs is subjected to SNV (Standard Normal Variate) processing to obtain abs'.

Next, in step 110, abs' is subjected to SG filter processing to obtain abs''. As a result, noise in the waveform of abs' is removed.

Next, in step 112, "abs" is subjected to second-order differential processing to obtain the SD.

Next, in step 114, the PET index corr, which is the correlation coefficient (correlation value, so-called Pearson's product-moment correlation coefficient), between the SD and the library data lib (spectral waveform of near-infrared rays partially absorbed by PET) is determined. seek.

Next, in step 116, it is determined whether the PET index corr exceeds the PET index threshold PB (whether the material of the determination target 14 is PET).

In step 116, if the PET index corr does not exceed the PET index threshold PB, then in step 118, it is determined that the determination target 14 is not a plastic bottle 16 and is output.

Further, in step 120 following step 108, abs' is subjected to SG filter processing to obtain absW''. This removes noise in the waveform of abs'.

Next, in step 122, absW'' is subjected to second-order differential processing to obtain SW.

Next, in step 124, the values of SW at 1880 nm and 1950 nm, which are the wavelengths of infrared absorption of water (liquid), are converted to absolute values and the sum is calculated, thereby calculating the residual liquid index ZW (near-infrared water (Absorption degree)

Next, in step 126, the residual liquid index ZW is output.

Then, in step 116, if the PET index corr exceeds the PET index threshold PB (if it is determined that the determination target 14 is a PET bottle 16), in step 128, the residual liquid index ZW is higher than the residual liquid index ZW. It is determined whether the index threshold value WT is exceeded (whether the PET bottle 16 contains residual liquid).

In step 128, if the residual liquid index ZW does not exceed the residual liquid index threshold value WT, in step 130, it is determined that the determination target 14 is an empty plastic bottle and is output.

On the other hand, in step 128, if the residual liquid index ZW exceeds the residual liquid index threshold value WT, in step 132, it is determined that the determination target 14 is a contained PET bottle and is output.

Here, in the NIR sensor 18, the light receiving unit 22 is provided with a diffusion plate 22A and a pipe 22B, and the diffusion plate 22A diffuses the near infrared rays received by the light receiving unit 22, and the near infrared rays diffused by the diffusion plate 22A The inner surface of the pipe 22B diffusely reflects the near infrared rays in the pipe 22B, thereby making the near infrared rays inside the pipe 22B uniform. Therefore, the near-infrared information received by the spectrometer 26 via the optical fiber 24 can be converted into near-infrared information in the range of the axis-perpendicular cross section inside the pipe 22B. As a result, even if the near-infrared rays from the light source section 20 are diffusely reflected by the unevenness of the judgment target 14 (for example, the unevenness of the circumferential wall of the PET bottle 16), the amount of near-infrared rays received by the spectrometer 26 can be increased. The spectroscopic analyzer 26 can appropriately determine the material of the plastic bottle 14 and the amount of residual liquid contained in the plastic bottle 16. Furthermore, unlike the case where near-infrared rays are focused on the light-receiving surface of one end of the optical fiber 24 using a lens, an expensive lens can be eliminated, making the light-receiving section 22 less expensive, and focusing of the lens can be eliminated and the light can be diffused. By being able to easily adjust the axial position of the plate 22A, the light receiving section 22 can be handled roughly, and the ease of maintenance such as replacement of the light receiving section 22 can be improved.

Further, in the NIR sensor 18, the light receiving section 22 receives the light transmitted through the determination target 14. Therefore, more near-infrared rays can be absorbed by the determination target 14, and the material of the determination target 14 can be appropriately determined.

Furthermore, the spectroscopic analyzer 26 determines the absorbance (residual liquid index ZW) due to the residual liquid in the PET bottle 16. Therefore, it is possible to determine whether the remaining liquid is contained in the PET bottle 16.

[Second embodiment]
FIG. 6 shows a top plan view of a plastic bottle determining device 50 as a plastic determining device according to a second embodiment of the present invention.

The PET bottle determination device 50 according to this embodiment has almost the same configuration as the first embodiment, but differs in the following points.

As shown in FIG. 6, in the PET bottle determination device 50 according to the present embodiment, in the NIR sensor 18, the light emitting surface 20A of the light source section 20 and the diffusion plate 22A of the light receiving section 22 are arranged at a distance of, for example, ° It is slanted. The light emitting surface 20A and the diffuser plate 22A are coaxially opposed to each other, and the direction in which the light emitting surface 20A and the diffuser plate 22A face each other is inclined by 45°, for example, with respect to the conveyance direction A of the determination target 14.

Here, in this embodiment as well, the same operation and effect as in the first embodiment can be achieved.

Furthermore, in the NIR sensor 18, the direction in which the light emitting surface 20A of the light source section 20 and the diffusion plate 22A of the light receiving section 22 face each other is inclined with respect to the conveying direction A of the determination target 14, so that the near-infrared rays irradiated from the light source section 20 The direction is inclined with respect to the longitudinal direction (vertical direction) of the determination target 14. Therefore, by increasing the near-infrared irradiation range (transmission range) for the determination target 14 in the longitudinal direction of the determination target 14, it is possible to increase the near-infrared rays irradiated from the light source unit 20 to the determination target 14. The amount of near-infrared rays absorbed can be increased, and the material of the determination target 14 and the residual liquid contained in the PET bottle 16 can be appropriately determined.

In the first and second embodiments described above, the CPU 28 reads software (program) and executes the plastic bottle determination process. However, the plastic bottle determination process may be executed by various processors other than the CPU. In this case, the processor includes a PLD (Programmable Logic Device) whose circuit configuration can be changed after manufacturing, such as an FPGA (Field-Programmable Gate Array), and an ASIC (Application Specific Integrated Circuit). Dedicated to execute specific processing such as cuit) An example is a dedicated electric circuit that is a processor having a circuit configuration designed to. Furthermore, the plastic bottle determination process may be executed by one of these various processors, or by a combination of two or more processors of the same type or different types (for example, multiple FPGAs, and a combination of a CPU and an FPGA). combinations etc.). Further, the hardware structure of these various processors is, more specifically, an electric circuit that is a combination of circuit elements such as semiconductor elements.

Further, in the first and second embodiments described above, the PET bottle determination program is stored (installed) in the ROM 30 or the storage 34 in advance, but the program is not limited thereto. The program is recorded on recording media such as CD-ROM (Compact Disk Read Only Memory), DVD-ROM (Digital Versatile Disk Read Only Memory), and USB (Universal Serial Bus) memory. It may be provided in the form of Further, the program may be downloaded from an external device via a network.

Furthermore, in the first and second embodiments described above, the material of the determination target 14 (plastic) determined by the spectroscopic analyzer 26 is PET. However, the material of the determination target 14 determined by the spectroscopic analyzer 26 may be other plastics (for example, PE (polyethylene) or PP (polypropylene)).

10 PET bottle determination device (plastic determination device)
12 Conveyor (transport mechanism)
14 Judgment target 20 Light source section (irradiation section)
22 Light receiving section 22A Diffusion plate (diffusion section)
22B pipe (diffuse reflection part)
26 Spectroscopic analyzer (judgment mechanism)
50 PET bottle determination device (plastic determination device)

Claims (2)

a transport mechanism that transports a plastic judgment target;
an irradiation unit that is disposed on one side of the transport mechanism and irradiates the determination target with light in a direction oblique to a direction in which the determination target is transported by the transport mechanism;
a light receiving unit disposed on the other side of the transport mechanism and receiving light emitted from the irradiation unit , transmitted through the determination target, and partially absorbed by the determination target;
a diffusion section that is provided in the light receiving section and that diffuses the light received by the light receiving section;
a diffused reflection section provided in the light receiving section and configured to diffusely reflect the light diffused by the diffusion section;
a determination mechanism that determines a material to be determined based on the light received by the light receiving section;
A plastic determination device comprising: The plastic determining device according to claim 1 , wherein the determining mechanism determines the absorbance of the liquid to be determined .