Identification device, identification method, and article manufacturing method

Abstract

This identification device comprises: a first irradiation unit and a second irradiation unit that irradiate an object with light; a light receiving unit that receives light from the object; and an identification unit that identifies the type of the object on the basis of the result of light reception by the light receiving unit. The first irradiation unit and the light receiving unit are arranged such that the light receiving unit receives light due to reflection of the irradiation light of the first irradiation unit on the surface of the object. The illuminance of the light with which the object is irradiated by the first irradiation unit is lower than the illuminance of the light with which the object is irradiated by the second irradiation unit.

Description

Identification device, identification method, and method for manufacturing articles

[0001] The present invention relates to an identification device, an identification method, and a method for manufacturing articles.

[0002] In recent years, as part of efforts to realize a decarbonized society and mitigate global warming, the recycling of waste plastic resources has been promoted in various industries, including the automotive and home appliance industries. Since waste plastic resources contain various types of plastics, it is necessary to identify and classify them by type.

[0003] Patent Document 1 discloses a technique for identifying the type of plastic piece by spectrally analyzing the reflected infrared light irradiated onto the plastic piece.

[0004] Japanese Patent Publication No. 2023-25463

[0005] However, because different plastic pieces (objects) have different infrared light reflection properties, there can be significant differences in the intensity of reflected light, making it difficult to accurately identify the type of object.

[0006] An identification device as one aspect of the present invention comprises a first irradiating unit and a second irradiating unit that irradiate an object with light, a light receiving unit that receives light from the object, and an identification unit that identifies the type of object based on the result of receiving light from the light receiving unit, wherein the first irradiating unit and the light receiving unit are arranged so that the light receiving unit receives light reflected from the irradiated light of the first irradiating unit on the surface of the object, and the illuminance of the light irradiated onto the object by the first irradiating unit is lower than the illuminance of the light irradiated onto the object by the second irradiating unit.

[0007] According to the present invention, it is possible to provide an identification device that is advantageous for accurately identifying the type of object.

[0008] A diagram showing the sorting device in the first embodiment. A flowchart showing each step of the sorting method in the first embodiment. A diagram showing the configuration of the measuring unit in the first embodiment. A diagram showing the configuration of the measuring unit in the first embodiment. A diagram showing the configuration of the measuring unit in the first embodiment. A diagram showing the arrangement of infrared light illumination in the first embodiment. A diagram showing the configuration of the infrared light spectrometer in the first embodiment. A diagram showing the arrangement of infrared light illumination in a comparative example. A diagram showing the reflectivity characteristics of the resin. A diagram to explain the relationship between illumination angle and reflected light amount. A diagram to explain the relationship between illumination angle and reflected light amount. A diagram to explain the relationship between illumination angle and reflected light amount. A diagram to explain the relationship between illumination angle and reflected light amount. A diagram to explain the relationship between illumination angle and reflected light amount. A diagram to explain the relationship between illumination angle and reflected light amount. A diagram showing the relationship between irradiation intensity ratio and reflected light amount in the first embodiment. A diagram showing the arrangement of infrared light illumination in the second embodiment. A diagram showing the arrangement of infrared light illumination in the third embodiment. A diagram showing the configuration of the identification device in the fourth embodiment. A flowchart showing each step of the identification method in the fourth embodiment.

[0009] The embodiments will be described in detail below with reference to the attached drawings. Note that the following embodiments do not limit the invention as defined in the claims. While the embodiments describe multiple features, not all of these features are essential to the invention, and the features may be combined in any way. Furthermore, in the attached drawings, identical or similar configurations are given the same reference numerals, and redundant descriptions are omitted.

[0010] <First Embodiment> A sorting device 100 according to the first embodiment of the present invention will be described. The sorting device 100 is a device that, for example, identifies the type of object being transported along a transport path and sorts the object by type based on the identification result. In this embodiment, an example of sorting transported objects will be described. The type of object is, for example, the material (raw material) or size of the object. The sorting device 100 identifies at least one of the material and size and sorts based on the identification result.

[0011] In this embodiment, an example is described in which a belt conveyor is used as a conveying mechanism for transporting objects, and the transport path of the objects is defined by the upper surface of the belt conveyor. However, the conveying mechanism is not limited to a belt conveyor, as it can transport objects, for example, a hand that holds and transports objects. Similarly, the transport path is not limited to the upper surface of a belt conveyor, as it can be any path through which objects are transported, for example, a path through which objects are transported by a hand.

[0012] Figure 1 shows a sorting device 100 according to this embodiment. The sorting device 100 includes an identification device 10 that identifies the type of object being transported on a belt conveyor, and a sorting unit 19 that sorts objects according to desired material and size. Specifically, the sorting device 100 may include a belt conveyor 11, a measuring unit 12, a discriminating unit 14 (sorting mechanism), a sorting box 15, an identification processing unit 17 (identification unit), a drive unit 18, and objects 16 that are transported on the belt conveyor.

[0013] The belt conveyor 11 moves a belt made of rubber, resin, or metal at a predetermined speed, and a predetermined size and belt movement speed are set according to the processing capacity of the sorting system. The measuring unit 12 includes an infrared light illumination unit that irradiates (illuminates) with infrared wavelength light, and an infrared light spectroscopic camera (light receiving unit) that is sensitive to infrared wavelengths and equipped with a spectrometer. In this specification, the light receiving unit includes an image sensor and a light receiving optical system. The infrared light illumination irradiates within the illumination range 13 on the belt, which is shown by the dashed line in Figure 1, and the infrared light spectroscopic camera receives reflected light from the object 16.

[0014] The sorting unit 14 has multiple openings distributed in the width direction of the belt conveyor 11, and each opening is an air nozzle that releases compressed air at an independent timing. The sorting boxes 15 are prepared for each type to be sorted and are containers for storing the objects sorted by the sorting unit 14.

[0015] Object 16 is a thermoplastic or thermosetting plastic crushed to a size of approximately 5 to 100 mm, such as PP resin (polypropylene resin) or ABS resin (a resin containing acrylonitrile, butadiene, and styrene). The sorting device 100 is fed onto a belt conveyor by a quantitative cutting device (not shown) that crushes plastic products and supplies a fixed amount of crushed plastic pieces at a time, and by a vibrating feeder that suppresses overlapping of objects through vibration. The identification processing unit 17 is a computing device such as a computer or a programmable logic controller.

[0016] The system includes a signal input / output unit based on information from the measurement unit 12, and after identifying the material of the object, it sends a drive signal to the drive unit 18. The drive unit 18 is a pneumatic device equipped with multiple solenoid valves, which open and close the solenoid valves based on the drive signal from the identification processing unit 17 and send compressed air to the valve separation unit 14. Next, each step of the sorting method in the sorting device 100 will be explained with reference to Figures 1 and 2.

[0017] The sorting method may include steps S301 to S307 in the flowchart of Figure 2. Each step in the flowchart is controlled by a main control unit (not shown). In step S301, objects 16 are fed onto the belt conveyor 11 by a quantitative cutting device or a vibrating feeder (not shown).

[0018] In step S302, the measuring unit 12 irradiates the object 16 passing through the irradiation range 13 with infrared light (irradiation step). In step S303, the measuring unit 12 receives the infrared light reflected from the surface of the object 16 (light receiving step).

[0019] In step S304, the wavelength distribution of the reflected light is imaged via a spectrometer in the measurement unit and sent to the identification processing unit 17. The identification processing unit 17 performs calculation processing on the wavelength distribution image to convert it into a spectral waveform that shows the light intensity for each wavelength. In addition, the identification processing unit 17 stores a reference spectral waveform of the plastic to be sorted in its internal memory, compares it with the spectral waveform of the reflected light to calculate a correlation value, and identifies objects that have a correlation value equal to or greater than a predetermined value as the target material (identification step).

[0020] In step S305, a main control unit (not shown) determines whether the object 16 is of a specific type based on the identification result in step S304. If it is of a specific type, the process proceeds to step S306; otherwise, the process proceeds to step S307. In step S306, the identification processing unit 17 calculates the timing and position of the identified object 16 on the belt conveyor 11 as it passes over the discrimination unit 14, and sends a drive signal to the drive unit 18.

[0021] The drive unit 18 opens and closes a predetermined solenoid valve based on a drive signal to release compressed air to the sorting unit 14. As a result, when an object 16 sent from the belt conveyor 11 passes over the sorting unit 14, compressed air is discharged from the sorting unit 14 toward the object 16, changing its trajectory, and it is stored in a sorting box 15 prepared for each material, completing the sorting process (sorting step). In step S307, the drive unit 18 does not release compressed air to the sorting unit 14, and the object is stored in a collection box (not shown), completing the sorting process (sorting step).

[0022] Furthermore, in order for the identification processing unit 17 to calculate the timing at which the identified object 16 passes over the discrimination unit 14, it is preferable to obtain speed information in addition to position information on the belt conveyor 11. Speed ​​information may be obtained from a rotating part such as a motor that drives the belt conveyor 11 using a device such as an encoder, but other means may also be used. For example, the conveying speed of the belt conveyor 11 may be directly measured by a speed sensor that measures the conveying speed of the belt conveyor 11.

[0023] Next, the means for identifying the object 16 in this embodiment will be described. Figure 3A is an XZ plan view showing the configuration of the measuring unit 12. In Figure 3A, when the object 16 passes below the measuring unit 12, infrared light is emitted from the infrared light illuminator 33 (first illumination unit) and the infrared light illuminator 35 (second illumination unit) provided inside the measuring unit 12.

[0024] Infrared light emitted from infrared illuminator 33 (optical axis 43) and infrared light emitted from infrared illuminator 35 (optical axis 44) are reflected by the surface of object 16, and the reflected light (optical axis 24) is incident on the infrared spectrophotometer 25. The reflected light (optical axis 24) includes reflected light (first reflected light) not shown from the infrared light emitted from infrared illuminator 33 (optical axis 43) and reflected light (second reflected light) not shown from the infrared light emitted from infrared illuminator 35 (optical axis 44). Furthermore, the infrared spectrophotometer 25 receives each of the reflected lights.

[0025] Here, the light sources for infrared illumination 33 and infrared illumination 35 are, for example, lamps, LEDs, or laser oscillators that emit light of infrared wavelengths. Furthermore, infrared illumination 33 and infrared illumination 35 are line illuminations, making it possible to illuminate the entire width of the belt conveyor 11 at once. In object sorting using infrared light, the characteristic that light of a specific wavelength is absorbed by the material of the object 16 when irradiated with infrared light, and light of components that are not easily absorbed is reflected is utilized.

[0026] Therefore, the wavelength of the infrared light is adjusted so that it includes a wavelength range that is absorbed by the material of the object 16 to be identified. For example, if the object 16 is made of ABS resin, a wavelength range of 3.5 to 5.0 μm is suitable for the infrared light. In addition, optical filters that transmit only the target wavelength may be inserted into the irradiation optical systems of the infrared light illumination 33 and infrared light illumination 35 as needed, to cut out unwanted infrared light wavelengths that may cause heat generation.

[0027] Next, the arrangement of the infrared light illumination 33 and infrared light illumination 35 is shown. The number of infrared light illumination 33 and infrared light illumination 35 can be one or more, and in this embodiment, an example in which one of each is arranged will be described. Infrared light illumination 33 is advantageous for gloss illumination when measuring objects with high gloss, and infrared light illumination 35 is advantageous for diffuse illumination when mainly measuring objects with high gloss (objects with rough surfaces).

[0028] The angle (first angle, θ) between the optical axis 43 of the light emitted from the infrared light illumination 33 and the normal 21 of the mounting surface 22 passing through the object 16. １), and the angle (second angle, θ) between the optical axis 44 of the light emitted from the infrared light illumination 35 and the normal 21 of the mounting surface 22 passing through the object 16. ２ These angles are all different. Specifically, the first angle is the angle between the optical axis 24 and the normal 21 of the mounting surface 22 passing through the object (the third angle, θ) which is different from the second angle. ３ The lighting positioned to be close to the ) is the infrared light illumination 33 (glossy lighting).

[0029] Furthermore, the optical axis of the optical system of the infrared light illumination 33 is synonymous with the optical axis of the light emitted from the infrared light illumination 33, and the optical axis of the optical system of the infrared light illumination 35 is synonymous with the optical axis of the light emitted from the infrared light illumination 35. Also, the optical axis of the optical system of the infrared light spectrometer camera 25 is synonymous with the optical axis of the light incident on the infrared light spectrometer camera 25. Moreover, the optical axis of the light incident on the light receiving unit is synonymous with the normal to the imaging surface passing through the center of the imaging surface of the light receiving unit, and is synonymous with the optical axis of the light incident on the light receiving optical system of the light receiving unit. The imaging surface of the light receiving unit is synonymous with the light receiving surface of the sensor that receives the light that is reflected off the surface of the object 16 from the infrared light illumination 33 or infrared light illumination 35 and incident on the infrared light spectrometer camera 25.

[0030] Furthermore, it is desirable that the infrared light illumination 33 (gloss illumination) be positioned within an angular range in which the light reflected from the surface of the object by the infrared light illumination 33 can be captured by the infrared light spectrometer 25. Specifically, in this embodiment, the infrared light illumination 33 is positioned with respect to the infrared light spectrometer 25, straddling the normal 21 of the mounting surface 22 that passes through the object, as shown in the arrangement in Figure 3A.

[0031] Note that the light reflected by the infrared light illumination 33 (first illumination unit) represents the specular reflection component. Also, Figure 3B is an XY plan view showing the configuration of the measurement unit 12, and it shows that the infrared light illumination 33, infrared light illumination 35, and infrared light spectrophotometer 25 are arranged along the transport direction of the object 16.

[0032] Note that in the present embodiment, as shown in FIG. 3B, the infrared light illumination 33, the infrared light illumination 35, and the infrared light spectroscopic camera 25 are arranged along the conveyance direction of the object 16, but they may be arranged along a predetermined direction parallel to the placement surface 22 (not shown) as shown in FIG. 3C. Specifically, when the placement surface 22 is viewed from above in a direction perpendicular to the placement surface 22, the centers of the infrared light illumination 33, the infrared light illumination 35, and the infrared light spectroscopic camera 25 are arranged to be substantially on the same straight line within a virtual XY plane (not shown) parallel to the placement surface 22.

[0033] Note that during arrangement, each of the infrared light illumination 33, the infrared light illumination 35, and the infrared light spectroscopic camera 25 may be arranged offset in the Z-axis direction. Further, the infrared light illumination 33 is arranged such that the light obtained by specularly reflecting the irradiation light of the infrared light illumination 33 on the surface of the object (first reflected light) can be received by the spectroscopic camera. It is desirable that the infrared light illumination 33 be arranged such that the incident angle and the reflection angle are equal as the angular range in which the specularly reflected light can be received.

[0034] On the other hand, when the NA (numerical aperture) of the infrared light spectroscopic camera 25 is set to 0.1, as shown in FIG. 4, the infrared light illumination 33 may be arranged to approach the infrared light spectroscopic camera 25 up to 11.5°, or the infrared light illumination 33 may be arranged to be offset away from the infrared light spectroscopic camera 25 up to 11.5°. That is, the first angle θ １ may have a maximum error of 11.5°. Further, the illuminance of the infrared light illumination 33 (hereinafter sometimes also referred to as intensity) is set lower than the illuminance of the infrared light illumination 35. In addition, the object 16 conveyed on the belt conveyor is simultaneously irradiated by the infrared light illumination 33 and the infrared light illumination 35, and the reflected light (optical axis 24) thereof is acquired by the infrared light spectroscopic camera 25.

[0035] FIG. 5 is a diagram showing the configuration of the infrared light spectroscopic camera. The object 16 is arranged on the belt conveyor 11, and the object 16 is conveyed in the direction of the arrow in FIG. 5. In FIG. 5, the region surrounded by the dashed-dotted line is the irradiation range 13 of the infrared light illumination, and the dotted line shown within the irradiation range (illumination range) is the field-of-view range 34 of the infrared light spectroscopic camera 25.

[0036] A visual field range 34 is defined by a slit 38 to be described later. Reflected light 6 from the visual field range 34 passes through a lens 36, a mirror 37, the slit 38, a lens 39, and a diffraction grating 40, and enters an image sensor 42 of an area camera 41 having sensitivity to infrared light. Here, the plane of the visual field range 34, the plane of the slit 38, and the image sensor 42 are each in an imaging relationship, and the focal lengths of the lens 36 and the lens 39 are set such that a desired region on the belt conveyor 11 can be imaged onto the image sensor 42.

[0037] The diffraction grating 40 has a characteristic of diffracting passing light at different angles for each wavelength of the light, and the wavelength distribution included in the reflected light is projected two-dimensionally onto the image sensor 42. Through the above operations, the reflected light from the object 16 passing through the visual field range 34 is continuously imaged to acquire an image of the wavelength distribution, which is sent to the identification processing unit 17.

[0038] Next, simulation results showing that the material of an object can be identified with high accuracy by the configuration of the present embodiment will be described. For comparison with the present embodiment, FIG. 6 shows the arrangement of infrared illumination of a comparative example. In FIG. 6, two infrared illuminations 51 and 52 of the same type are arranged line-symmetrically with respect to the optical axis 46 of light incident on the infrared spectroscopic camera 25.

[0039] Further, in order to compare the comparative example and the present embodiment, the amounts of reflected light in the illumination arrangements of the comparative example and the present embodiment were respectively simulated based on the angular dependence (15 patterns) of the amount of reflected light of plastics having various surface properties and reflectances as shown in FIG. 7. Then, the maximum value and the minimum value of the reflected light amounts of the 15 patterns were calculated, and the dynamic range of the camera required to measure the 15 patterns of plastics was calculated from the ratio thereof.

[0040] FIGS. 8A to 8F respectively show the simulation results of the comparative example (FIG. 8A) and the present embodiment (FIG. 8B). FIGS. 8A and 8B show illumination arrangement conditions, and FIGS. 8C and 8D show the angular dependence of the reflected light amount of 15 patterns of resin (horizontal axis: illumination angle, vertical axis: reflected light amount). Further, FIGS. 8E and 8F respectively show the angular dependence of the ratio between the maximum value and the minimum value of the reflected light amounts of the 15 patterns (horizontal axis: illumination angle, vertical axis: maximum / minimum ratio).

[0041] Note that the vertical axes (reflected light amount) in FIGS. 8C and 8D are values normalized by taking the reflected light amount of a perfect diffuse surface (isotropically reflecting surface) as 1, which is an arbitrary unit (a.u.). In addition, θ in FIGS. 8A to 8F is the angle formed by the optical axis 47 of the infrared light illumination 52 and the optical axis 46 of the infrared light spectroscopic camera 25, and θ in FIGS. 8A to 8F ２ is the angle formed by the optical axis 44 of the infrared light illumination 35 and the normal line 21 of the mounting surface 22 on which the object 16 is mounted.

[0042] Further, in the present embodiment, the angle θ ２ being positive means that the optical axis 44 of the infrared light illumination 35 is on the same side as the infrared light spectroscopic camera 25 with respect to the normal line 21 of the mounting surface 22 on which the object is mounted. In addition, the angle θ ２ being negative means that the optical axis 44 of the infrared light illumination 35 is on the opposite side of the infrared light spectroscopic camera 25 with respect to the normal line 21 of the mounting surface 22 on which the object 16 is mounted.

[0043] That is, the angle θ ２ being positive means that in FIG. 8B, the infrared light illumination 35 is on the same side as the infrared light spectroscopic camera 25 with respect to the surface (the normal line 21 on the XZ plane) that passes through the intersection of the optical axis 44 and the mounting surface 22 on which the object 16 is mounted and intersects the mounting surface 22. In addition, the angle θ ２ being negative means that in FIG. 8B, the infrared light illumination 35 is on the opposite side of the infrared light spectroscopic camera 25 with respect to the surface (the normal line 21 on the XZ plane in FIG. 8B) that passes through the intersection of the optical axis 44 and the mounting surface 22 on which the object 16 is mounted and intersects the mounting surface 22.

[0044] The simulation results of this embodiment shown in Figures 8A to 8F were calculated under the following conditions: The angle between the optical axis 24 and the normal 21 of the light incident on the infrared light spectrometer 25 is 45°, the angle between the optical axis 43 and the normal 21 of the infrared light illumination 33 is 45°, and the intensity ratio of the infrared light illumination 35 to the infrared light illumination 33 is 0.15. Furthermore, as a physical arrangement constraint for the infrared light spectrometer 25 and each illumination, it is desirable, but not limited to, that the difference in the arrangement angles between adjacent cameras and illuminations be 10° or more to avoid interference. In other words, it is desirable, but not limited to, that the angle between adjacent optical axes within optical axis 43, optical axis 44, and optical axis 24 be 10° or more.

[0045] As shown in Figures 8A to 8F, the minimum dynamic range of the camera required to identify all 15 patterns of objects is 16.7 in the comparative example and 6.1 in this embodiment. This demonstrates that this embodiment can reduce the required dynamic range of the camera compared to the comparative example. In other words, this result shows that it is possible to identify the material of object 16 with high accuracy, regardless of the surface properties or reflectivity of object 16, and that it is possible to select objects of a specific material from objects containing various materials.

[0046] Figure 9 is a graph showing the relationship between the "intensity ratio of infrared illumination 35 to infrared illumination 33" and the "maximum / minimum ratio of reflected light" in this embodiment. In Figure 3A, the infrared illumination 33 and the infrared spectroscopic camera 25 are arranged approximately symmetrically with respect to the normal 21 of the mounting surface 22 on which the object 16 is placed. Therefore, if the intensity ratio of infrared illumination 35 to infrared illumination 33 is 1 or more, the dynamic range becomes large, and high-precision object identification may become difficult.

[0047] Therefore, in this embodiment, as shown in Figure 9, by setting the intensity ratio of infrared light illumination 35 to infrared light illumination 33 to less than 1, the dynamic range can be reduced compared to a configuration where the intensity ratio is 1 or more. When the intensity ratio is 0.8 or less (80% or less), the dynamic range becomes 13, and the effect is demonstrated by reducing the dynamic range more effectively than in the comparative example. Furthermore, under conditions where the intensity ratio is 0.5 or less (50% or less), the effect of reducing the dynamic range by this embodiment is significant, and the number of resins that can be identified increases. Therefore, it is more preferable to set the illuminance of infrared light illumination 33 to 50% or less of that of infrared light illumination 35.

[0048] As described above, in this embodiment, the identification device 10 is arranged such that the infrared light illuminator 33 and the infrared light spectrophotometer 25 are received by the infrared light spectrophotometer 25 after the light emitted from the infrared light illuminator 33 is specularly reflected by the object 16. Furthermore, by setting the illuminance of the infrared light illuminator 33 lower than that of the infrared light illuminator 35, the identification device 10 can identify and sort objects by material with high precision, regardless of the surface properties or reflectance of the objects. This reduces the dynamic range required for the camera. In other words, it becomes possible to sort objects that could not be sorted in the comparative example, resulting in the effect of being able to identify objects with high precision.

[0049] <Second Embodiment> In this embodiment, an example is described in which the infrared light illumination 35 is positioned on the same side as the spectroscopic camera with respect to the normal 21 of the mounting surface 22 on which the object 16 is placed. The configuration of the infrared light spectroscopic camera 25 is the same as in the first embodiment, so its description is omitted. Furthermore, matters not mentioned in this embodiment follow those of the first embodiment.

[0050] First, the infrared light illumination 35 in this embodiment is at the angle θ of the infrared light illumination 35 in Figure 8B. ２ The arrangement is such that the angle θ is positive, and a schematic diagram of this is shown in Figure 10. Furthermore, in this embodiment, the angle θ ２ A positive value means that the optical axis 44 of the infrared light illumination 35 is on the same side as the infrared light spectrometer 25 with respect to the normal 21 of the mounting surface 22 on which the object 16 is placed. Also, the angle θ ２A negative value means that the optical axis 44 of the infrared light illumination 35 is on the opposite side of the infrared light spectroscopic camera 25 from the normal 21 of the mounting surface 22 on which the object 16 is placed.

[0051] The infrared light illumination 35 is used to illuminate the infrared spectrometer 25 so that diffusely reflected light (scattered light) can be received by the infrared spectrometer 25 when the surface of the object is rough. Since the diffusely reflected light (second reflected light) is emitted isotropically and a portion of it enters the infrared spectrometer 25, it is preferable, but not required, for the infrared light illumination 35 to be positioned on the opposite side of the infrared spectrometer 25 with respect to the normal 21 to achieve the maximum effect of the invention. For example, as shown in Figure 10, the angle θ between the optical axis of the light emitted from the infrared light illumination 35 and the normal 21 of the mounting surface 22 passing through the object. ２ The infrared light illumination 35 may be placed within the region where the value is positive.

[0052] In other words, the infrared light illumination 35 may be positioned on the same side as the spectroscopic camera with respect to the normal 21 of the mounting surface 22 passing through the object. Furthermore, as a physical constraint on the placement of the infrared light spectroscopic camera 25 and each illumination, it is desirable, but not limited to, that the difference in the placement angle between adjacent cameras and illuminations be 10° or more to avoid interference with each other.

[0053] The above is a description of this embodiment. As described above, the identification device 10 of this embodiment has the effect of being able to position the infrared light illuminator 35 regardless of the physical constraints associated with the positioning of the infrared light illuminator 33, by positioning the infrared light illuminator 35 on the opposite side of the infrared light spectroscopic camera 25 with respect to the normal 21.

[0054] <Third Embodiment> In this embodiment, an example in which the number of infrared light illuminators 35 is set to two will be described. Matters not mentioned in this embodiment will follow those of the first embodiment.

[0055] First, as an example, the two infrared light illuminators 35 in this embodiment have an angle θ of the infrared light illuminators 35 in Figures 8A to 8F. ２The arrangement is such that the angle θ is negative, and a schematic diagram of this is shown in Figure 11. Since diffuse reflected light is emitted isotropically and a portion of it is incident on the infrared light spectrometer 25, it is preferable, but not required, that the infrared light illumination 35 be positioned on the opposite side of the infrared light spectrometer 25. For example, one diffuse illumination is positioned at the angle θ in Figures 8A to 8F. ２ They are arranged so that it becomes negative, and the other one is θ ２ They may be arranged so that is positive, or both are θ ２ They may be arranged so that the result is positive.

[0056] Furthermore, in this embodiment, the angle θ ２ A positive value means that the optical axis 44 of the infrared light illumination 35 is on the same side as the infrared light spectrometer 25 with respect to the normal 21 of the mounting surface 22 on which the object 16 is placed. Also, the angle θ ２ A negative value means that the optical axis 44 of the infrared light illumination 35 is on the opposite side of the infrared light spectroscopic camera 25 from the normal 21 of the mounting surface 22 on which the object 16 is placed.

[0057] Furthermore, as a physical constraint on the placement of the infrared light spectroscopic camera 25 and the two infrared light illuminators 35, it is desirable, but not limited to, that the difference in the placement angle between adjacent cameras and illuminators be 10° or more to prevent interference. In this embodiment, an example with two infrared light illuminators 35 is described, but there is no limit to the number of illuminators, as long as there are two or more.

[0058] The above is a description of this embodiment. As described above, the identification device 10 of this embodiment has the effect of increasing the intensity of diffusely reflected light by using two infrared light illuminators 35, thereby reducing the required dynamic range of the camera.

[0059] <Fourth Embodiment> In this embodiment, a desktop identification device 20 that identifies the type of object using infrared light illumination will be described. Figure 12 is a schematic diagram showing the configuration of the identification device 20. The identification device 20 is a device for taking a small sample of a large number of resin pieces that have been sorted by a sorting device and checking the sorting results in a simple manner.

[0060] The identification device 20 identifies the type of each object based on the measurement results from the measuring unit 12 for multiple objects 16 placed on a stationary tray 5.

[0061] Next, each step of the identification method in the identification device 20 will be described. The identification method may include steps S308 to S314 in the flowchart of Figure 13. Each step in the flowchart is controlled by a main control unit (not shown).

[0062] In step S308, the tray 5 on which the object is placed is moved from the loading / unloading section 4 into the irradiation area and the tray 5 is brought to a stop. In step S309, the recognition unit 2 recognizes the object 16 on the tray 5. In step S310, the measurement unit 12 irradiates the object recognized by the recognition unit 2 in step S309 with infrared light (irradiation step).

[0063] In step S311, the measuring unit 12 receives infrared light reflected from the surface of the object 16 (light receiving step). In step S312, the wavelength distribution of the reflected light is imaged via a spectrometer in the measuring unit 12 and sent to the identification processing unit 17. The identification processing unit 17 performs calculation processing on the wavelength distribution image to convert it into a spectral waveform that shows the light intensity for each wavelength.

[0064] In addition, the identification processing unit 17 stores a standard spectral waveform of the plastic to be sorted in its internal memory, compares it with the spectral waveform of the reflected light to calculate a correlation value, and identifies objects that have a correlation value equal to or greater than a predetermined value as the target material (identification step).

[0065] In step S313, the identification processing unit 17 outputs the identification result, which is information about the types of multiple objects 16, onto the display unit 8 for display. The display unit 8 is a liquid crystal display, an organic EL display, or the like, and is used to display the information necessary for the identification device 20.

[0066] In step S314, the tray 5 is unloaded from the loading / unloading section 4, and the object 16 is removed from the device. Each step is performed by the main control unit (not shown) of the identification device 20.

[0067] Furthermore, the field of view of the recognition unit 2 may be configured to include the illumination range of the infrared illumination light used to identify the object 16, so that the position of the object 16 can be recognized after it has come to a standstill. In addition, depending on the position of the object being illuminated, the main control unit may control the angular arrangement of at least one of the two types of infrared light illumination (not shown) and the spectroscopic camera (not shown) within the measurement unit 12.

[0068] Furthermore, while the description includes a configuration in which the objects 16 are placed on a tray 5 and transported into the identification device 20 as a means of transporting and stationing multiple objects 16 within the irradiation range, a tray is not required. For example, multiple objects may be arranged in a line on a belt conveyor belt and transported into the irradiation range, and the objects may be stationary within the irradiation range.

[0069] <Embodiment of Article Manufacturing Method> The identification device 10 according to the above embodiment can be used in an article manufacturing method to identify the type of object 16 and to manufacture an article such as a plastic product from the identified object. This article manufacturing method includes, for example, an identification step of identifying the type using the identification device 10, a sorting step of sorting objects based on the identification result of the identification step, and a processing step of processing the objects. An article is then manufactured by the processing step.

[0070] Furthermore, the identification device 20 according to the above embodiment can be used in a method for manufacturing articles, which involves identifying the type of object 16 and manufacturing articles such as plastic products from the identified object. This article manufacturing method includes, for example, an identification step of identifying the type using the identification device 10, and a processing step of processing the object based on the identification result of the identification step. The article is then manufactured by the processing step.

[0071] The processing of the plastic piece may include, for example, melting, molding, cutting, assembly, and inspection. The method for manufacturing the article of this embodiment is advantageous compared to conventional methods in at least one of the following: article performance, quality, productivity, and production cost.

[0072] Although preferred embodiments of the present invention have been described above, it goes without saying that the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of its essence.

[0073] The present invention is not limited to the embodiments described above, and various modifications and variations are possible without departing from the spirit and scope of the invention. Accordingly, the following claims are attached to make the scope of the invention public.

[0074] This application claims priority based on Japanese Patent Application No. 2025-068607, filed on 18 April 2025, and all of its contents are incorporated herein by reference.

[0075] 10, 20 Identification device 16 Object 17 Identification processing unit (identification unit) 25 Infrared light spectrophotometer (light receiving unit) 33 Infrared light illumination (first illumination unit) 35 Infrared light illumination (second illumination unit)

Claims

1. An identification device comprising: a first irradiating unit and a second irradiating unit for irradiating an object with light; a light receiving unit for receiving light from the object; and an identification unit for identifying the type of object based on the result of receiving light from the light receiving unit, wherein the first irradiating unit and the light receiving unit are arranged so that the light receiving unit receives light reflected from the irradiating light of the first irradiating unit on the surface of the object, and the illuminance of the light irradiated onto the object by the first irradiating unit is lower than the illuminance of the light irradiated onto the object by the second irradiating unit.

2. The identification device according to claim 1, characterized in that the first angle formed by the normal to the mounting surface on which the object is placed and the optical axis of the light emitted from the first irradiation unit is different from the second angle formed by the normal to the surface and the optical axis of the light emitted from the second irradiation unit.

3. The identification device according to claim 1 or 2, characterized in that the first illuminating unit, the second illuminating unit, and the light-receiving unit are each arranged such that the difference between the first angle and the third angle formed by the normal and the normal of the imaging surface passing through the center of the imaging surface of the light-receiving unit is smaller than the difference between the second angle and the third angle.

4. The identification device according to any one of claims 1 to 3, characterized in that the light receiving unit is arranged to receive light scattered from light irradiated onto the object by the second irradiation unit.

5. The identification device according to any one of claims 1 to 3, characterized in that the light receiving unit is arranged so as not to receive light that is specularly reflected on the surface of the object from the light emitted from the second irradiation unit.

6. The identification device according to any one of claims 1 to 5, characterized in that the illuminance of the light irradiated onto the object by the first irradiating unit is 80% or less of the illuminance of the light irradiated onto the object by the second irradiating unit.

7. The identification device according to any one of claims 1 to 6, characterized in that the light receiving unit simultaneously receives a first reflected light emitted from the first irradiation unit that is reflected on the surface of the object, and a second reflected light emitted from the second irradiation unit that is reflected on the surface of the object.

8. The identification device according to any one of claims 1 to 7, characterized in that the object is positioned between the second irradiation unit and the light receiving unit in a predetermined direction parallel to the mounting surface.

9. The identification device according to any one of claims 1 to 7, characterized in that the second irradiation unit is positioned between the object and the light receiving unit in a predetermined direction parallel to the mounting surface.

10. The identification device according to any one of claims 1 to 9, further comprising a transport mechanism for transporting the object in the transport direction.

11. The identification device according to claim 10, characterized in that each of the first irradiation unit, the second irradiation unit, and the light receiving unit is arranged along the transport direction.

12. The identification device according to any one of claims 1 to 11, characterized in that the angle between the optical axis of the light emitted from the first irradiation unit and the optical axis of the light emitted from the second irradiation unit is 10° or more.

13. An identification device comprising: a first irradiation unit and a second irradiation unit for irradiating an object with light; a light receiving unit for receiving light from the object; and an identification unit for identifying the type of object based on the result of receiving light from the light receiving unit, wherein the difference between a first angle formed by the normal of the mounting surface on which the object is placed and the optical axis of the light emitted from the first irradiation unit, and a third angle formed by the normal of the mounting surface and the normal of the imaging surface passing through the center of the imaging surface of the light receiving unit, is smaller than the difference between a second angle formed by the normal of the mounting surface and the optical axis of the light emitted from the second irradiation unit, and a third angle formed by the normal of the mounting surface and the normal of the imaging surface, and the illuminance of the light irradiated onto the object by the first irradiation unit is lower than the illuminance of the light irradiated onto the object by the second irradiation unit.

14. A sorting device comprising: an identification device according to any one of claims 1 to 13; and a sorting unit for sorting objects based on the results identified by the identification device.

15. An identification method comprising: an illumination step of illuminating an object with light from a first irradiating unit and a second irradiating unit; a light receiving step of receiving light from the object with a light receiving unit; and an identification step of identifying the type of object based on the result of receiving light in the light receiving step, wherein the first irradiating unit and the light receiving unit are arranged so that the light receiving unit receives light reflected from the irradiating light of the first irradiating unit on the surface of the object, and in the illumination step, the illuminance of the light irradiated onto the object from the first irradiating unit is lower than the illuminance of the light irradiated onto the object from the second irradiating unit.

16. A sorting method characterized by comprising: an identification step of identifying an object using the identification method described in claim 15; and a sorting step of sorting the object based on the identification result of the identification step.

17. A method for manufacturing an article, comprising: an identification step of identifying an object using the identification method described in claim 15; and a processing step of processing the object identified in the identification step, wherein an article is manufactured from the object processed in the processing step.

18. The method for manufacturing an article according to claim 17, further comprising a sorting step for sorting the objects after the identification step.

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