Single point analyzer

Abstract

An inspection system (100) configured to detect and analyze a material (2), the inspection system comprising: illumination means (101) for emitting optical radiation to illuminate the material (2); a detector system (110) having at least one detector (120) adapted to receive and detect the optical radiation; a white reference target element (19); and a switching element (11) comprising at least one inspection zone (12), at least one black reference zone (13) and at least one white reference zone (14). The switching element (11) can be rotated between at least one inspection position in which the inspection zone (12) transmits light radiation originating from the material (2) towards the detector system (110), at least one black reference position in which the inspection zone (12) transmits light radiation originating from the material (2) towards the detector system (110), and at least one white reference position in which the inspection zone (12) transmits light radiation originating from the material (2) towards the detector system (110). The switching element (11) blocks at least a majority of the light radiation originating from the material (2) from reaching the detector system (110), and the black reference region (13) faces the at least one detector (120), in at least one white reference position, in which at least a majority of the light radiation originating from the material (2) reaches the detector system (110). The switching element (11) blocks at least a majority of the optical radiation originating from the material (2) from reaching the detector system (110), and the white reference region (14) redirects and transmits the optical radiation originating from the white reference target element (19) towards the detector system (110).

Description

TECHNICAL FIELD

[0001] The inventive concept described herein relates generally to inspection systems for detecting and analyzing material and to a method for calibrating such inspection systems. BACKGROUND

[0002] The field of automatic detection and analysis of objects is continuously developing and is applied in a wide range of industries. For example, sensor-based sorting systems are used in the recycling and waste management industry. The classification and sorting of objects is based on properties of the objects, which are analyzed by detector systems including, for example, optical spectral measurement systems, laser triangulation measurement systems and / or camera-based systems. To ensure a good quality of the data obtained by such detector systems, the calibration of the detectors must be carried out periodically.

[0003] Generally, for performing the calibration, the measurement of objects is stopped and reference elements are arranged in the inspection area so that these elements are measured by the detector instead of the objects at regular time intervals, for example, every five minutes. A disadvantage of this procedure is that the measurement operation of the system is interrupted during the calibration procedure and no measurements can be made in the inspection area during this time.

[0004] Furthermore, sensor-based sorting systems are typically used in parallel and / or serial configurations in material recycling plants. In the recycling process, especially in the supervision of such material recycling plants, there is a need for continuously optimizing the material analysis. A disadvantage of the existing material analysis in such material recycling plants, which enables monitoring of the recycling process, sorting quality control and / or maintenance or performance control, etc., is that no efficient solution can be found without interrupting the process.

[0005] US5991046 discloses a method and apparatus for measuring and controlling optical properties of moving webs. The apparatus includes a calibration unit comprising: an operating element which is a hole in the calibration unit; a matte non-fluorescent reference of known high diffuse reflectance for white level calibration; and a black reference such as a cavity or other light trap, or a matte non-fluorescent black tile, or a material of known low diffuse reflectance for black level calibration.

[0006] DE10318892A1 discloses a system for continuous online reference calibration of a spectral near-infrared (NIR) measurement system, wherein a movable reference disc is arranged between the measurement head and the plane on which the product under inspection is passed. The disc is rotated or displaced to allow a calibration standard or reference standard to be temporarily positioned in front of the measurement head. SUMMARY

[0007] In view of the above, it is an object of the present inventive concept to provide a device for an inspection system and a method for calibration and a cost-effective arrangement for factory supervision and monitoring, wherein such inspection system has advantages in providing reliable calibration and / or factory supervision and monitoring without interrupting the measurement operation.

[0008] According to a first aspect of the present inventive concept, there is provided an inspection system configured to detect and analyze a material arranged in an inspection region, the inspection system comprising: - an illumination device for emitting light radiation in a first predetermined wavelength range, such as UV, VIS, MIR and / or NIR, to illuminate the material, - a detector system having at least one detector adapted to receive and detect characteristic radiation in a second predetermined wavelength range, such as UV, VIS, MIR and / or NIR, which is light radiation reflected, scattered and / or emitted by the material, - a switching element arranged rotatable around an axis of rotation between at least one inspection position, at least one black reference position and at least one white reference position, - a white reference target element configured to be illuminated by reference radiation, which is light radiation emitted by the illumination device, and configured to redirect the reference radiation towards the switching element, and - optical means for redirecting the characteristic radiation towards the switching element, wherein the switching element comprises a plate comprising: - at least one inspection zone, each inspection zone being an opening or a window in the plate, - at least one black reference zone, each black reference zone being an opaque portion of the plate, and - at least one white reference zone, each white reference zone comprising an opening or an optical window in the plate and an associated reflective element comprising a reflective surface, the reflective element being arranged such that, in the at least one white reference position of the switching element, the reflective surface of the reflective element is illuminated by the reference radiation and redirects the reference radiation towards the detector system, and the reflective element blocks the characteristic radiation to prevent it from reaching the detector system, and wherein the switching element is arranged rotatable around the axis of rotation such that: - in each of the at least one inspection position of the switching element, a respective one of the at least one inspection zone transmits the characteristic radiation that has been redirected by the optical means and transmits the characteristic radiation towards the detector system, - in each of the at least one black reference position of the switching element, a respective one of the at least one black reference zone blocks all or at least most of the characteristic radiation to prevent it from reaching the detector system, - At each of the at least one white reference positions of the switching element, a corresponding associated reflective element associated with the corresponding white reference region is configured to be irradiated by the characteristic radiation, and the associated reflective element is configured to block the characteristic radiation to prevent it from reaching the detector system. The reflective surface of the corresponding associated reflective element is configured to be irradiated by reference radiation and redirect the reference radiation toward the corresponding white reference region, and the opening or optical window of the corresponding white reference region is configured to transmit the reference radiation toward the detector system.

[0009] In the statement "the corresponding associated reflective element associated with the corresponding white reference area is configured to be irradiated by characteristic radiation", "corresponding white reference area" should be understood as a corresponding white reference area among at least one white reference area. Furthermore, it should be understood that the associated reflective element is configured to be irradiated by characteristic radiation.

[0010] In the context of this disclosure, the expression "light radiation originating from the material" should be interpreted as light radiation reflected, scattered, and / or emitted by the material. This may be referred to as "characteristic radiation." The expression "light radiation originating from the white reference target element" should be interpreted as light radiation redirected by the white reference target element.

[0011] Alternatively, an inspection system is provided configured to detect and analyze materials arranged in an inspection area, the inspection system comprising: - An irradiation device for emitting light radiation within a first predetermined wavelength range, such as UV, VIS, MIR, and / or NIR, to irradiate materials. - A detector system having at least one detector adapted to receive and detect characteristic radiation within a second predetermined wavelength range, such as UV, VIS, MIR, and / or NIR, which is light radiation reflected, scattered, and / or emitted by a material. - Optical device for redirecting light radiation reflected, scattered, and / or emitted by a material toward at least one detector. - White reference target element, and - A switching element, including at least one inspection area, at least one black reference area and at least one white reference area.

[0012] The switching element can be arranged to rotate about a rotation axis between at least one inspection position, at least one black reference position, and at least one white reference position, such that: - At each of the at least one inspection positions of the switching element, a corresponding inspection area in at least one inspection zone allows light radiation originating from the material and redirected by the optical device to be transmitted toward the detector system. - At each of the at least one black reference positions of the switching element, the switching element blocks at least a majority of light radiation originating from the material to prevent it from reaching the detector system, and a corresponding black reference area in at least one black reference area faces at least one detector. - At each of the at least one white reference positions of the switching element, the switching element blocks at least most of the light radiation originating from the material to prevent it from reaching the detector system, and a corresponding white reference area in at least one white reference area redirects and transmits the light radiation originating from the white reference target element toward the detector system.

[0013] According to a second aspect of the invention, a method for calibrating an inspection system is provided, the inspection system being configured to detect and analyze materials disposed in an inspection area, the inspection system comprising: - An irradiation device for emitting light radiation within a first predetermined wavelength range, such as UV, VIS, MIR, and / or NIR. - A detector system having at least one detector adapted to receive and detect characteristic radiation, which is light radiation reflected, scattered, and / or emitted by a material, and - A switching element, arranged to rotate about a rotation axis between at least one inspection position, at least one black reference position, and at least one white reference position, wherein the switching element includes a plate comprising: at least one inspection area, each inspection area being an opening or window in the plate; at least one black reference area, each black reference area being an opaque portion of the plate; and at least one white reference area, each white reference area including an opening or optical window in the plate and an associated reflective element, the associated reflective element including a reflective surface. - White reference target element, and - Optical device for redirecting characteristic radiation toward the switching element. The method includes: The irradiation device emits light radiation within a first predetermined wavelength range, such as UV, VIS, MIR, and / or NIR, to irradiate the material. The optical device redirects the characteristic radiation toward the switching element. The step of rotating the switching element to the inspection position of the switching element, wherein characteristic radiation is received from the optical device and transmitted through a corresponding inspection area in at least one inspection area of ​​the switching element, and then received by at least one detector. The step of rotating the switching element to the black reference position of the switching element, wherein a corresponding black reference region in at least one black reference region blocks all or at least most of the characteristic radiation to prevent it from reaching the detector system, and the black reference level is measured by at least one detector on the corresponding black reference region in at least one black reference region of the switching element. The steps of rotating the switching element to the white reference position of the switching element and illuminating the white reference target element with reference radiation, wherein the reference radiation is light radiation emitted by the illuminating device, wherein a reflective element of a corresponding white reference region in at least one white reference region blocks at least most of the characteristic radiation to prevent it from reaching the detector system, and the reference radiation: Redirection from the white reference target element to the switching element. Then the reflective surface of the reflective element is redirected toward the detector system, and Then, it is transmitted toward the detector system through an opening or optical window in at least one of the corresponding white reference areas, and The white reference level is measured on the white reference target element using at least one detector.

[0014] Alternatively, a method is provided for calibrating an inspection system configured to detect and analyze materials arranged in an inspection area, the inspection system comprising: - A detector system having at least one detector adapted to receive and detect light radiation originating from a material, and - A switching element, including at least one inspection area, at least one black reference area and at least one white reference area.

[0015] The method may include: - The step of rotating the switching element to the inspection position of the calibration element and receiving light radiation originating from the material and transmitted through at least one inspection area of ​​the switching element via at least one detector. - The steps of rotating the switching element to its black reference position, such that the switching element blocks at least most of the light radiation originating from the material to prevent it from reaching the detector system, and measuring the black reference level on at least one black reference region of the switching element, and - The step of rotating the switching element to the white reference position of the switching element such that the switching element blocks at least most of the light radiation originating from the material to prevent it from reaching the detector system, and measuring the white reference level on the white reference target element, wherein the light radiation originating from the white reference target element is redirected by at least one white reference area of ​​the switching element and transmitted toward the detector system.

[0016] According to a third aspect of the present invention, a sorting system for sorting objects is provided, the sorting system comprising: - An upstream conveying device and at least a first downstream conveying device and a second downstream conveying device, each of the upstream conveying device and at least the first downstream conveying device and the second downstream conveying device including at least one of a conveyor belt, a chute, or a free fall path. - An analysis device configured to analyze and determine at least one characteristic of an object being transported on an upstream conveying device. - Sorting device, configured as follows: o According to a first criterion and a second criterion based on at least one characteristic, sort objects into at least one of a first category and a second category, and o provides objects sorted into the first category to the first downstream conveyor and objects sorted into the second category to the second downstream conveyor. The sorting system may further include an inspection system according to the first aspect, the inspection system being arranged such that the inspection area overlaps with at least a portion of the first downstream conveyor. The inspection system may be configured to: o Determine at least one characteristic of the object in the inspected area, o Determine whether at least one characteristic of an object in the inspected area satisfies a first criterion, and A quality score is established based on the ratio of the number of times an object passing through the inspection area satisfies at least one characteristic of the first criterion to the number of times at least one characteristic of the object passing through the inspection area is determined.

[0017] Preferred embodiments of the present invention are set forth in the dependent claims.

[0018] The present invention offers at least the following advantages: - Provides continuous white and black calibration for the detection system. - Only one moving element is needed to provide white and black calibration. Therefore, the system is very reliable, and - The inventive concept allows for the compact design of the inspection system.

[0019] In the context of this disclosure, continuous calibration means that the calibration process is performed simultaneously with the measurement process during the operation of the inspection system according to the first aspect. More specifically, the detector of the detector system can operate at a given sampling rate (e.g., 40 kHz). When the switching element is in its inspection position, the detector receives and detects characteristic radiation from the material in the inspection area, and the detected light radiation is integrated over the time during which the switching element is in its inspection position. This can be referred to as a measurement. When the switching element is in its black reference position, a black calibration of the detector is performed. When the switching element is in its white reference position, a white calibration is performed. Thus, each measurement can be calibrated using the black calibration and / or white calibration performed within one rotation of the switching element.

[0020] Therefore, from the operator's perspective, the calibration process is not separate from the measurement process. This increases the available time for measurement, as the measurement process does not need to be interrupted to perform black and / or white calibration.

[0021] A switching element may include two or more inspection areas, two or more black reference areas, and two or more white reference areas. For example, a switching element may include 2 to 8 inspection areas, 2 to 8 black reference areas, and 2 to 8 white reference areas. A switching element may have an even number of inspection areas, black reference areas, and / or white reference areas. A switching element may have a non-even number of inspection areas, black reference areas, and / or white reference areas.

[0022] In embodiments where the switching element has two or more inspection areas, two or more black reference areas, and two or more white reference areas, each inspection position of the switching element is associated with a corresponding inspection area in the inspection areas, each black reference position of the switching element is associated with a corresponding black reference area in the black reference areas, and each white reference position of the switching element is associated with a corresponding white reference area in the white reference areas.

[0023] In some example implementations, the switching element can be arranged to rotate at a speed of 1400 rpm, 2000 rpm, 2500 rpm, or 3000 rpm, or any speed in the range of 1 rpm to 10000 rpm. When the inspection system is used to inspect a stream of samples conveyed by a conveyor in a sorting workshop, a rotational speed in the range of 100 rpm to 10000 rpm may be suitable. When the inspection system is used to inspect a small number of samples conveyed by a conveyor in a sorting station, a rotational speed in the range of 10 rpm to 5000 rpm may be suitable. When the inspection system is part of a handheld unit, a rotational speed in the range of 1 rpm to 1000 rpm may be suitable.

[0024] The rotational speed of the switching element is preferably adapted to the number of inspection zones included in the switching element to obtain a suitable number of measurements per minute, depending on the application at hand.

[0025] The inspection system can be adapted to perform single-point analysis. Therefore, the inspection system can be arranged such that the light radiation emitted by the irradiation device is guided to the material in the inspection area along a fixed optical path. In other words, during the operation of the inspection system, the optical path of the light radiation emitted by the irradiation device remains unchanged, and the light radiation emitted by the irradiation device does not scan the inspection area.

[0026] Material may be conveyed through the inspection area, for example, on a conveyor belt. Additionally or alternatively, material may be conveyed through the inspection area on a chute or slide or by free fall. Additionally or alternatively, material may be static in the inspection area, at least during measurement.

[0027] The inspection area can be defined as a 2D area. For example, the inspection area can be part of a conveyor belt, chute, or slide on which material is conveyed through the inspection area. The inspection area can also be a platform of the inspection system. The platform can be movable to convey material to the appropriate measurement location. The platform can be static during measurement.

[0028] In an embodiment where the inspection area is the portion of the conveyor belt through which material is transported, the inspection system can be configured to shut off the irradiation device when the conveyor belt stops. This prevents heat buildup on the surface of the conveyor belt in the inspection area.

[0029] In embodiments where the inspection system's platform is static, the inspection area can be provided, for example, by utilizing a honeycomb structure for heat protection, on which the material to be inspected is arranged. The honeycomb structure can be positioned above air-filled voids or boxes. Therefore, irradiation from the irradiation device can at least partially penetrate the honeycomb structure, preventing heat buildup. This allows the surface temperature at the inspection area to remain within acceptable finger-touch levels, thereby improving operator safety.

[0030] In embodiments where the inspection system platform is static, the inspection area may be equipped with a device to dissipate heat from the inspection area, such as using a cooling system for example, convection, airflow, or water, to allow for safe operation by the operator.

[0031] The inspection system can be a handheld measuring device for portable use. In this configuration, the inspection area can be changed according to the orientation of the handheld measuring device (i.e., the position the handheld measuring device is pointing).

[0032] For example, an inspection system can be configured to analyze materials conveyed on conveyor belts in a sorting workshop. The inspection system is a single-point analyzer and may not analyze all materials conveyed on the conveyor; that is, the inspection system's field of view does not cover the entire width of the conveyor belt. However, it can provide valuable statistical data. For instance, if the materials conveyed on the conveyor are randomly distributed across the width of the conveyor, a sufficiently large sample collected by the single-point analyzer (i.e., a sufficient number of measurements over a sufficient time frame) can be representative of the materials conveyed in the conveyor.

[0033] According to one example, such a system can be used downstream of a sorting device in a sorting workshop to, for example, control the quality of the sorting process. The sorting process can separate a material stream into two separate material streams with different properties. For example, a stream of PET bottles can be sorted into a first stream of clear PET bottles and a second stream of colored PET bottles; multiple streams selected from, for example, the group consisting of: streams containing clear plastic, streams containing white plastic, streams containing red plastic, streams containing blue plastic, streams containing foreign matter, and combinations thereof.

[0034] The inspection system conceived according to the present invention can be arranged to inspect a portion of the first flow and assess the quality of sorting: the system detects any colored PET bottles or other residues, which means an error has occurred during the sorting process.

[0035] Inspection systems can also be offline inspection systems, meaning they operate outside the material flow within the sorting room. For example, in a sorting room, there may be materials in the correct location that the system has not detected correctly. A sample of this material can be analyzed offline to obtain training data for the sorting system. The results are then fed into a learning algorithm to build a classifier and configure the sorting system.

[0036] The irradiation device preferably includes at least one irradiation / illumination source selected from the group consisting of LEDs, halogen lamps, and / or lasers. For example, the irradiation source can be a broadband spectral source, such as a halogen light source. A suitable halogen light source can have a spectral distribution starting from about 400 nm and significantly attenuating at about 2.5 μm. The maximum emission power can occur at about 1.3 μm. Alternatively, a xenon arc light source can be used as the irradiation source. Shorter wavelengths, such as 200 nm and above, can be achieved by using a xenon arc light source. As another alternative, an LED light source can be used as the irradiation source.

[0037] Additionally or alternatively, illumination sources suitable for spectroscopy can be used as illumination sources. For example, LED light sources can be advantageously used for UV fluorescence spectroscopy. Heating elements can be advantageously used for mid-infrared spectroscopy. Supercontinuum lasers can be used as illumination sources for high spatial and spectral resolution spectrometry systems. Multiple wavelength lasers can be combined for high spatial and spectral resolution multispectral measurement systems. LEDs and pulsed LEDs can be used as illumination sources for highly spatially optimized multispectral measurement systems. Different types of illumination sources can also be combined.

[0038] According to at least one example embodiment, the switching element includes a plate. Each inspection area may be an opening or window in the plate, each black reference area may be an opaque portion of the plate, and each white reference area may include an opening or optical window in the plate and an associated reflective element including a reflective surface. The reflective element may be arranged such that at at least one white reference position of the switching element, the reflective element blocks light radiation from the material to prevent it from reaching the detector system, and the reflective surface of the reflective element redirects light radiation originating from or redirected by the white reference target element toward the opening or window of the white reference area for transmission toward the detector system.

[0039] In this implementation, the switching element plate can be arranged close to the detector system. This provides a compact solution. Furthermore, when in the black reference position, this can increase the amount of characteristic radiation that is blocked by the switching element from reaching the detector system.

[0040] The switching element can have a generally circular shape. Therefore, the board of the switching element can include a main board or disk, which includes openings or windows for the inspection area and the white reference area, respectively. For each white reference area, the switching element may also include a protrusion containing a reflective element.

[0041] The plate can have a diameter of 100 mm to 300 mm, or 150 mm to 250 mm, or 175 mm to 225 mm, or 5 mm to 100 mm, the latter size being suitable, for example, for a handheld scanner. For example, the plate can have a diameter of 200 mm to 210 mm. The plate can have a material thickness of 1 mm to 10 mm or 0.1 mm to 1 mm. For example, the plate can have a material thickness of 3 mm.

[0042] According to at least one example embodiment, the switching element includes at least two white reference areas, each white reference area including an optical window that includes a filter. The at least two white reference areas are preferably arranged in pairs, radially opposite to each other, relative to the axis of rotation.

[0043] This allows for the verification, monitoring, or control of the spectral alignment of the detector system.

[0044] According to at least one example embodiment, at least one white reference position includes at least a first white reference position and a second white reference position, a white reference target element includes a first portion and a second portion, and at least one white reference region includes a first white reference region and a second white reference region. The switching element is further arranged such that, when arranged at the first white reference position of the switching element, the first white reference region redirects and transmits light radiation originating from or reflected or redirected by the first portion of the white reference target element toward the detector system. The switching element is further arranged such that, when arranged at the second white reference position of the switching element, the second reference region redirects and transmits light radiation originating from or reflected or redirected by the second portion of the white reference target element toward the detector system.

[0045] According to at least one example embodiment, at least one white reference position includes at least a first white reference position and a second white reference position, a white reference target element includes a first portion and a second portion, and at least one white reference region includes a first white reference region and a second white reference region. The switching element is further arranged such that when arranged at the first white reference position of the switching element, the first white reference region will reflect or redirect reference radiation reflected or redirected by the first portion of the white reference target element toward the detector system and transmit it. The switching element is further arranged such that when arranged at the second white reference position of the switching element, the second reference region will reflect or redirect reference radiation reflected or redirected by the second portion of the white reference target element toward the detector system and transmit it. Therefore, in each of the first and second white reference regions, only the corresponding one of the first and second portions of the white reference target element will redirect radiation toward the detector.

[0046] Therefore, the reference target element may include at least two parts with different properties. Reflective elements in different white reference regions may be arranged to reflect or redirect light radiation originating from or reflected by different parts of the reference target element.

[0047] For example, the corresponding reflective elements of the first subset of the white reference area may extend from the main plane of the plate at a first angle relative to the main plane, and the corresponding reflective elements of the second subset of the white reference area may extend from the main plane of the plate at a second angle relative to the main plane.

[0048] This arrangement allows for monitoring or controlling the spectral alignment of the detector system.

[0049] According to at least one example embodiment, the switching element includes at least two inspection areas, at least two black reference areas, and at least two white reference areas, and each inspection area, black reference area, and white reference area is arranged radially opposite to another inspection area, another black reference area, and another white reference area, respectively, relative to the axis of rotation.

[0050] In other words, the inspection area, black reference area, and white reference area can be arranged symmetrically around the rotation axis of the switching element.

[0051] In this configuration, the switching element can also be arranged such that all planes containing the axis of rotation divide the switching element into two parts of substantially equal mass.

[0052] This reduces the swaying and / or vibration of switching components during the operation of the inspection system. This is beneficial for the accuracy of the inspection system.

[0053] According to at least one example embodiment, the reflective element of each white reference area extends from the main plane of the plate such that the normal of the reflective surface forms an angle of 10° to 85°, or 20° to 75°, or 30° to 65°, or 40° to 50° relative to the main plane.

[0054] This provides ease of setting up the white reference target. In particular, it provides a good balance between the ability of the reflective element to block characteristic radiation from the material to prevent it from reaching the detector system and the ability of the reflective surface of the reflective element to reflect or redirect light radiation originating from or reflected or redirected by the white reference target element toward the opening or window of the white reference area so that it can be transmitted to the detector system.

[0055] According to at least one example embodiment, the switching element further includes at least one or more encoder elements associated with the area, the encoder elements being used in operation to identify the inspection area, the black reference area, or the white reference area.

[0056] This can improve the reliability of the system and ensure that the detector system and switching elements are properly synchronized.

[0057] According to at least one exemplary embodiment, the white reference target element is arranged to be irradiated by the irradiation device of the inspection system.

[0058] This allows the system to operate using only a single source of illumination. Consequently, this can provide lower energy consumption.

[0059] According to at least one example implementation, the detector system is a spectral measurement system.

[0060] In the context of this application, a spectral measurement system is a system that includes a prism or diffraction grating for separating light radiation into different wavelength ranges, measuring wavelengths and intensities, in order to analyze and identify materials.

[0061] According to one embodiment, the spectral measurement system includes a detector that is sensitive to different spectral bands due to, for example, the properties of the detector material, and / or a filter disposed in front of or directly in front of the detector material.

[0062] The method according to the second aspect can be appropriately implemented using the inspection system described in conjunction with the first aspect. It should be understood that any feature and implementation method of the first aspect can be implemented in the method according to the second aspect, provided it is compatible with this method. Attached Figure Description

[0063] The inventive concept and some non-limiting embodiments, including specific features and advantages, will now be further described with reference to the accompanying drawings, in which: Figure 1 This is a perspective view of an inspection system including the equipment conceived according to the present invention. Figures 2a to 2b These are illustrations of two different implementations of the switching element. Figures 3a to 3c These are schematic diagrams of the cross-sections of the inspection system with the switching element in its inspection position, black reference position, and white reference position, respectively. Figures 4a to 4d These are different views of an example arrangement of an inspection system based on the present invention, which is an independent offline system. Figure 5 A switching element with four white reference areas is shown, two of which include optical windows that include filters. Figure 6 A schematic diagram of a sorting system is shown, which is equipped with an inspection system based on the present invention. Detailed Implementation

[0064] Figure 1 An inspection system 100 according to the present invention is shown.

[0065] Typically, the inspection system 100 includes: irradiation devices 101, 140 for emitting light radiation within a first predetermined wavelength range, such as UV, VIS, MIR, and / or NIR, to irradiate the material. - Detector system 110, having at least one detector adapted to receive and detect characteristic radiation within a second predetermined wavelength range, such as UV, VIS, MIR, and / or NIR, which is light radiation reflected, scattered, and / or emitted by a material. - Switching element 11 is arranged to rotate about the rotation axis R between at least one inspection position, at least one black reference position, and at least one white reference position. - A white reference target element 19, configured to be irradiated by reference radiation and configured to redirect or reflect the reference radiation toward the switching element 11, the reference radiation being light radiation emitted by the irradiation device 101, and - Optical device 130, for redirecting characteristic radiation toward switching element 11, The switching element 11 includes a board, which includes: - At least one inspection area, each inspection area being an opening or window in the panel. - At least one black reference area, each black reference area being the opaque portion of the plate, and - At least one white reference area, each white reference area including an opening or optical window in a plate and an associated reflective element, the associated reflective element including a reflective surface, the reflective element being arranged such that at at least one white reference position of the switching element, the reflective surface of the reflective element is irradiated by reference radiation and redirects the reference radiation toward the detector system 110, and the reflective element blocks characteristic radiation to prevent it from reaching the detector system 110, and The switching element 11 is arranged to rotate about the rotation axis R, such that: - At each of the at least one inspection positions of the switching element 11, a corresponding inspection area in at least one inspection zone transmits the characteristic radiation after the characteristic radiation has been redirected by the optical device 130, and transmits the characteristic radiation toward the detector system. - At each of the at least one black reference positions of the switching element, a corresponding black reference region in at least one black reference region blocks all or at least most of the characteristic radiation to prevent it from reaching the detector system 110. - At each of the at least one white reference positions of the switching element 11, a corresponding associated reflective element associated with the corresponding white reference region is configured to be irradiated by the characteristic radiation, and the associated reflective element is configured to block the characteristic radiation to prevent it from reaching the detector system 110, and The reflective surface of the corresponding associated reflective element is configured to be irradiated by reference radiation and to redirect or reflect the reference radiation toward the corresponding white reference region, and the opening or optical window of the corresponding white reference region is configured to transmit the reference radiation toward the detector system 110.

[0066] The inspection system may include an illumination source 101 and an associated parabolic reflector 140 for guiding light radiation from the illumination source 101 toward the material 2 disposed in the inspection area. Optionally, the parabolic reflector may be replaced with another type of focusing reflector. In other words, in Figure 1 In one example, the inspection system 100 includes an illumination device that includes an illumination source 101 and a parabolic reflector 140.

[0067] The optical device, including the folding mirror 130, is arranged to redirect characteristic radiation (i.e., light radiation reflected, scattered, and / or emitted by the material) toward at least one detector of the detector system 110.

[0068] The optical path from the irradiation device to the material is in Figures 3a to 3c Marked by a dashed line 102'. See also: Figures 3a to 3c The light radiation (hereinafter referred to as characteristic radiation) reflected, scattered and / or emitted by the material in the inspection area follows the light path 103 and is redirected by the folding reflector 130 toward the detector of the inspection system 100.

[0069] return Figure 1 The detector system 110 includes at least one detector ( Figure 1 (not shown in the image), the at least one detector is adapted to receive and detect light radiation in a second predetermined wavelength range, such as UV, VIS, MIR and / or NIR, which is reflected, scattered and / or emitted by the material. Figure 1 Only the housing 111 of the detector system is shown. The housing 111 has an opening 115 in its side 113 (in... Figure 1 (Not visible in the center) to allow light radiation to reach the detector system 110 inside the housing 111, detector 120.

[0070] The inspection system also includes a switching element 11 capable of rotating about a rotation axis R and an actuator for rotating the switching element. (This will be combined with...) Figure 2a and Figure 2b A more detailed description of the switching element. In Figure 1 In the diagram, the switching element is shown in its white reference position.

[0071] Figure 2a An embodiment of the switching element 11 is shown. The switching element 11 has a main circular plate or disk that is rotatable about the rotation axis R. Figure 2a The switching element has two inspection areas 12, two black reference areas 13, and two white reference areas 14. The inspection areas 12 are openings 15 or windows in the plate through which characteristic radiation from the material can be transmitted. Figure 2a In the example, each inspection zone 12 covers a circular segment of approximately 120° and has a constant radial width on the circular segment (except for the circular edges at each end of the inspection zone).

[0072] As an example, the main board of switching element 11 can have a diameter of 207 mm. The opening of each inspection area can have a width of 30 mm, as viewed in the radial direction of the board.

[0073] Each white reference area 14 includes an opening 17 or optical window in the plate, the size of which is similar to that of the opening 15 of the inspection area 12. Each white reference area 14 also includes an associated reflective element 18, which extends from the plate at an angle of 10° to 85°, or 20° to 75°, or 30° to 65°, or 40° to 50°. The reflective element 18 is arranged such that its edge closest to the center of the plate (i.e., closest to the axis of rotation R) is connected to the plate, wherein the opposite edges of the reflective element 18 are furthest from the center of the plate and furthest from the surface of the plate. Thus, light radiation following, for example, a light path parallel to the surface of the plate can be redirected by the reflective element 18 to pass through the opening 17 associated with the reflective element 18 in the white reference area.

[0074] Therefore, the switching element 11 includes the same number of openings 17 or optical windows (in the white reference area) as the reflecting element 18; each reflecting element 18 is associated with a corresponding opening 17 or optical window. Figure 2a In one implementation, there are two white reference areas 14, and therefore two openings 17 or optical windows, and two reflective elements 18, each of which is associated with a corresponding one of the two openings 17 or optical windows.

[0075] The black reference area 13 of the switching element 11 is the opaque part of the switching element 11.

[0076] The switching element also includes an encoder element 20. Here, each white reference area is associated with an encoder element 20. Therefore, the encoder element 20 allows the inspection system to determine the switching element's position at the white reference each time. Thus, the detector system and the switching element can be continuously synchronized during the operation of the inspection system to avoid drift.

[0077] The encoder element may be additionally or alternatively arranged to be associated with the inspection area 12 and / or black reference area 13 of the switching element 11.

[0078] Figure 2b An alternative embodiment of the switching element 11 is shown, which includes four inspection areas 12, four black reference areas 13, and four white reference areas 14. Figure 2b Implementation methods and Figure 2a The difference in the implementation is that the inspection area 12 is smaller, that is, a smaller circular segment of the plate covering the switching element 11, to make room for additional black and white reference areas. As shown in the figure, Figure 2b Each inspection area 12 covers an angle of approximately 33°, each black reference area 13 covers an angle of approximately 35°, and each white reference area 14 covers an angle of approximately 20°. By integrating these areas into the optics, electronics, or software, longer inspection areas can be used to improve the spectral quality of the measurements.

[0079] existFigure 2b In one implementation, there are four white reference areas 14, and therefore four openings 17 or optical windows 17 and four reflective elements 18, each of which is associated with a corresponding one of the four openings 17 or optical windows.

[0080] It should be noted that Figure 2b The encoder element is not shown. However, the encoder element can be configured and associated with each inspection area 12, black reference area 13, and / or white reference area 14, as per the description of the encoder element. Figure 2a As described.

[0081] Figures 3a to 3c This is a schematic diagram of the cross-section of the switching element 11 when the switching element is in the inspection position, the black reference position, and the white reference position, respectively.

[0082] Typically, the method for calibrating an inspection system according to the present invention can be derived from... Figures 3a to 3c As shown. The inspection system 100 includes: - Irradiation device 101, for emitting light radiation within a first predetermined wavelength range such as UV, VIS, MIR and / or NIR, - Detector system 110, having at least one detector 120, the at least one detector being adapted to receive and detect characteristic radiation, which is light radiation reflected, scattered, and / or emitted by a material, and - Switching element 11, arranged to be able to rotate around axis R in at least one inspection position (in Figure 3a (shown in), at least one black reference position (in) Figure 3b (as shown in) and at least one white reference position (in) Figure 3c (shown in the diagram) The switching element 11 rotates between the two locations, wherein the switching element 11 includes a plate comprising: at least one inspection area 12, each inspection area 12 being an opening 15 or window in the plate; at least one black reference area 13, each black reference area 13 being an opaque portion 16 of the plate; and at least one white reference area 14, each white reference area 14 including an opening 17 or optical window in the plate and an associated reflective element 18, the associated reflective element including a reflective surface. - White reference target element 19, and - Optical device 130 for redirecting characteristic radiation toward switching element 11.

[0083] The method includes: The irradiation device 101 emits light radiation within a first predetermined wavelength range, such as UV, VIS, MIR, and / or NIR, for irradiating the material. The optical device 130 redirects the characteristic radiation toward the switching element 11. The step of rotating the switching element 11 to the inspection position of the switching element 11, wherein the characteristic radiation is received from the optical device 130 and transmitted through a corresponding inspection area in at least one inspection area 12 of the switching element 11, and then received by at least one detector 120. The step of rotating the switching element 11 to the black reference position of the switching element 11 includes the following: a corresponding black reference region in at least one black reference region 13 blocks all or at least most of the characteristic radiation to prevent it from reaching the detector system 110, and the black reference level is measured by at least one detector 120 on the corresponding black reference region in at least one black reference region 13 of the switching element. The step of rotating the switching element 11 to the white reference position and illuminating the white reference target element 19 with reference radiation, wherein the reference radiation is light radiation emitted by the illuminating device 101, wherein a reflective element 18 of at least one white reference region 14 blocks at least most of the characteristic radiation to prevent it from reaching the detector system 110, while the reference radiation: The white reference target element is redirected or reflected towards the switching element. Received by the reflective surface of the reflective element 18 and redirected or reflected toward the detector system 110, and Received by an opening 17 or optical window in a corresponding white reference region of at least one white reference region 14 and transmitted toward the detector system 110, and The white reference level is measured on the white reference target element 19 by at least one detector 120.

[0084] The complete path from the irradiation device to the detector, as seen from the detector, can be read as follows: at the white reference position, after the radiation is incident on the reflective surface of the reflective element 18 and redirected by the reflective element, the detector receives the radiation, prior to which the radiation is incident on the white reference target element 19 and redirected by it, and prior to which the irradiation originates from the irradiation device.

[0085] In application texts, and for the sake of readability, the complete path from the irradiation source to a certain element (such as a white reference element) is sometimes omitted; instead, it is simply stated that the irradiation originates from that element. In other words, the statement "light radiation originating from the white reference target element" refers to light radiation originating from the light source and redirected by the white reference target element, for example, through reflection and optional scattering by the white reference target element. Furthermore, depending on, for example, the configuration of the inspection system and the type of material present in the inspection area, light from the irradiation device can be reflected, scattered, and / or transmitted through that material. Additionally, if the material is, for example, fluorescent or phosphorescent, the material can emit light in response to irradiation by, for example, UV radiation from the irradiation device. Regarding the inventive concept, the statement "light radiation originating from the material in the inspection area" refers to light radiation originating from the light source and reflected, scattered, and / or transmitted through the material, as well as light emitted by the material.

[0086] exist Figures 3a to 3c In each of the diagrams, the illumination source is schematically shown as 101. The light radiation emitted by illumination source 101 and directed towards the inspection area is marked by arrow 102'. It should be noted that, for clarity, Figure 1 The parabolic mirror 140 shown is not in Figures 3a to 3c As shown in the image.

[0087] The white reference element 19 is continuously irradiated by light radiation from the irradiation source 101. The light radiation from the irradiation source 101 to the white reference target element is indicated by arrow 102".

[0088] Implementations of discontinuous irradiation of the white reference target element are also conceivable. For example, the white reference target element may be irradiated only when the switching element is in the white reference position. For example, the irradiation device may include an irradiation source for emitting light radiation toward the inspection area and a separate irradiation source for irradiating the white reference target element. For example, the separate irradiation source may be turned on only when measuring the white reference level, i.e., when the switching element is in the white reference position.

[0089] exist Figure 3a The inspection position of the switching element 11 shown is such that the opening 15 of the inspection area 12 is aligned with the opening or window 115 of the housing of the detector system 110. Therefore, the characteristic radiation from the material in the inspection area and redirected by the folding reflector 130 has an unobstructed optical path 103 to the detector 120 of the detector system 110.

[0090] exist Figure 3bThe black reference position of the switching element 11, as shown, is aligned with the opening 115 of the housing of the detector system 110, forming a black reference region 13 comprised of the opaque portion 16 of the switching element 11. Therefore, characteristic radiation from material in the inspection area, redirected by the folded reflector 130, is blocked from reaching the detector 120 of the detector system at least along the optical path 103. If the switching element 11 is arranged sufficiently close to the housing of the detector system 110, at least a majority of the light radiation originating from outside the detector system 110 is blocked from reaching the detector 120. Thus, black reference calibration can be performed.

[0091] exist Figure 3c At the white reference position of the switching element 11 shown, the opening 17 of the white reference region 14 is aligned with the opening 115 of the housing 111 of the detector system 110. Characteristic radiation from the material in the inspection area and redirected by the folding reflector 130 is blocked by the reflective element 18 at least along the optical path 103 and reaches the detector 120 of the detector system 110. Reference radiation reflected or redirected by the white reference target element 19 travels along the optical path 104 and is redirected by the reflective surface of the reflective element 18 toward the detector 120 of the detector system, passing through the opening 17 of the white reference region 14. Therefore, white reference calibration can be performed.

[0092] In other words, when the inspection system is used, the irradiation source 101 is turned on and irradiates the material in the inspection area. Figure 1 In this configuration, the parabolic reflector 140 redirects radiation from source 101 toward the inspection area. Figures 3a to 3c The diagram at 102' shows the optical path or radiation from source 101 toward the material in the inspection area, where the parabolic reflector is omitted for clarity. The folding reflector 130 reflects or redirects the characteristic radiation (i.e., the light radiation scattered, reflected, and / or emitted by the material) along the optical path 103 toward the switching element 11.

[0093] At the same time, the irradiation source 101 also irradiates the white reference target element 19, such as Figures 3a to 3c The optical path 102'' is shown in the diagram.

[0094] The switching element 11 rotates about axis R. Therefore, at different times, different parts of the switching element 11 are aligned with the opening 115 of the housing 111 of the detector system 110. Figures 3a to 3c The inspection area, black reference area, and white reference area are aligned with opening 115, respectively.

[0095] When the switching element 11 is in such a state Figure 3a When the inspection position is shown, the characteristic radiation reflected or redirected by the folding reflector 130 is transmitted toward the detector 120 through the opening or window 15 in the switching element 11. Thus, the characteristic radiation can be measured by the detector 120.

[0096] Radiation received by the white reference target element 19 is redirected or preferably diffusely reflected by the white reference target element 19. However, these elements are positioned and oriented such that reference radiation reflected or redirected by the white reference target element 19 does not reach the detector 120. The term diffuse reflection refers to radiation that is reflected and scattered.

[0097] When the switching element 11 is in such a state Figure 3b At the indicated black reference position, the characteristic radiation reflected or redirected by the folded reflector 130 is blocked by the switching element 11, for example by the opaque surface of the switching element, and therefore does not reach the detector 120. Preferably, the opaque portion 16 of the switching element 11 is aligned with the opening 115 and blocks the characteristic radiation to prevent it from reaching the detector 120.

[0098] Any radiation received by the white reference target element 19 is redirected or diffusely reflected by it in the same way as when the switching element 11 is in the inspection position, and the reference radiation does not reach the detector 120. In fact, if the switching element 11 is arranged closer to the housing 111 of the detector system 110 than the optical path from the white reference target element, then when the switching element 11 is in the black reference position, most of the light from outside the housing 111 is blocked from entering the housing 111 through the opening 115 and reaching the detector 120 during black reference calibration. There are cases where it is conceivable to arrange the switching element further away and still achieve acceptable measurement results.

[0099] Notice, Figure 3a and Figure 3b Reference radiation reflected or redirected by white reference target element 19 is not shown.

[0100] When the switching element 11 is in such a state Figure 3c At the white reference position shown, the characteristic radiation reflected or redirected by the folding mirror 130 is blocked by the switching element 11 and therefore does not reach the detector 120. At this position of the switching element 11, a reflective element 18, protruding at an angle from the main board of the switching element 11, extends across the optical path, thereby blocking the characteristic radiation to prevent it from reaching the opening 115 of the housing 111 of the detector system 110. Therefore, after the characteristic radiation has been reflected or redirected by the folding mirror 130, the reflective element 18 blocks the characteristic radiation to prevent it from reaching the detector 120.

[0101] Radiation received by the white reference target element 19 is redirected or diffusely reflected by the white reference target element 19 in the same manner as when the switching element 11 is in the check position or in the black reference position. Therefore, as described above, photons or light particles emitted by the illumination source 101 can travel along the light path 102'' toward the white reference target element 19. Upon reaching the white reference target element 19, the photons are then reflected or redirected along the light path 104 toward the reflecting element 18 (more precisely, the reflecting surface of the reflecting element 18). Thus, the photons are received by the reflecting surface of the reflecting element 18 and reflected or redirected toward the opening or optical window 17, which is aligned with the opening 115 of the housing 111 of the detector system 110. Upon reaching the opening or optical window 17, the photons thus continue along the light path 104 through the opening 17, then through the opening 115, and finally reach the detector 120. It should be understood that when one such photon is, for example, on a path from the reflective surface of reflective element 18 toward detector 120, another photon is emitted by illumination source 101 and subsequently reflected or redirected by white reference target element 19, following the same path described above for the first photon. It should also be understood that when the reference radiation is diffusely reflected by white reference target element 19, not all photons redirected by white reference target element 19 will reach reflective element 18. Therefore, at least a portion of the reference radiation redirected by white reference target element 19 follows optical path 104 and is redirected toward detector 120. Thus, detector 120 can perform white reference calibration.

[0102] An example of the offline inspection system 200 conceived according to the present invention is shown in Figures 4a to 4d As shown in the image.

[0103] An offline system refers to an inspection system that is not part of a fixed facility, such as a sorting device, but can be arranged, for example, at an inspection table or a movable frame. Inspection system 200 is arranged on a movable frame 201 equipped with wheels 202 for easy transport. Detector system 110 is arranged within housing 111, wherein the inspection area (in...) Figures 4a to 4d (Not visible in the middle) is located below the shell 111.

[0104] The inspection area is located inside cabinet 203. Door 204 in cabinet 203 provides access to the inspection area for introducing materials to be inspected.

[0105] Figures 4a to 4d The inspection system depicted also includes a Tomra gain unit 205 for classifying materials through image analysis. The conveyor (in...) Figures 4a to 4d (Not visible in the center) can be set inside the cabinet 203 for conveying materials through the inspection area and / or between the field of view of the detector system 110 and the field of view of the gain unit 205.

[0106] The offline inspection system 200 includes a control cabinet 206 for controlling the inspection system (e.g., controlling the detector system 110, gain unit 205, and / or transmitter).

[0107] The frame 201 is provided with a laptop stand 207 for convenient placement of a laptop during system inspection operations.

[0108] Figure 5 Another example of the switching element 11 is shown, which includes at least two white reference areas, each white reference area including an optical window including a filter, and the at least two white reference areas are preferably arranged in pairs radially opposite each other relative to the axis of rotation.

[0109] In more detail, Figure 5 A switching element 11 is shown, comprising four inspection areas 12, four black reference areas 13, and four white reference areas 14a-d. Figure 5 In the view, only the windows 17a-d corresponding to the white reference area are visible.

[0110] Two opposing windows 17a and 17c are provided with filters. The filters of windows 17a and 17c may optionally be identical, that is, they may optionally have the same optical properties.

[0111] In this configuration, the white reference regions 14b and 14d without filters can be used as pure white references. Compared to reference regions 14b and 14d, reference regions 14a and 14c with filters will give different measurement results through the detector system. For example, reference regions 14a and 14c can be used to monitor or control the spectral alignment of the detector system.

[0112] Figure 6 A schematic diagram of a sorting system 300 equipped with an inspection system 100 according to an embodiment of the present invention is shown. The sorting system 300 is adapted to compile information about an object 2 and / or to classify the object 2 into, for example, at least a first category and a second category.

[0113] Inspection system 100 is adapted to inspect object 2 within inspection area 4. Inspection system 100 can be adapted to inspect the object within inspection area 4 when the object 2 is stationary or moving. In one embodiment, inspection system 100 is adapted to inspect object 2 within inspection area 4 when object 2 is continuously moving. The object 2 to be inspected can move along a predetermined path that starts, ends, or passes through inspection area 4. Figure 6 In the sorting system 300 depicted, object 2 travels through inspection area 4 along a path (in the direction T indicated by the arrow) by means of conveyor system 108.

[0114] The object 2 to be inspected can move along this path in other ways, some of which are non-limiting examples including, for example, sliding (along a horizontal or inclined plane) or free fall. Therefore, Figure 6 The conveyor system 108 is optional. Objects can move continuously or intermittently along the travel path. Figure 6 In the diagram, inspection system 100 is shown arranged to inspect objects that are normally located below inspection system 100. However, inspection system 100 is not limited to being arranged only to inspect objects that are normally located below inspection system 100 or moving below inspection system; alternatively, inspection system 100 may be arranged and / or oriented to be able to inspect objects 2 that are normally located on the side of inspection system 100 or moving to the side of inspection system.

[0115] The inspection system 100 may include a housing 105 for accommodating at least some of the components of the inspection system 100. The housing 105 may be positioned above or to the side of the object 2 to be inspected along a predetermined path of travel. Figure 6 In this configuration, housing 105 is positioned above conveyor system 108. Inspection system 100 is discussed in more detail with reference to, for example, Figure 2 and the other figures above.

[0116] Figure 6 The depicted sorting system 300 also includes an optional sorting device 112 disposed downstream of the inspection area 4. The sorting device 112 can be configured to sort the object 2 into at least one of a first category and a second category. The sorting device 112 may include a discharge device for delivering the sorted object 2 to one of at least two destinations, such as a first conveyor and a second conveyor disposed downstream of the sorting device.

[0117] The object 2 conveyed by the conveyor system 108 through the inspection area 4 in direction T may be unsorted. Alternatively, the object 2 conveyed by the conveyor system 108 through the inspection area 4 in direction T may be sorted, i.e., it may have already been sorted upstream of the conveyor system 108.

[0118] Figure 6 The depicted sorting system 300 may also include a control cabinet 109. The control cabinet 109 may be positioned above the conveyor system 108. The control cabinet 109 includes equipment for controlling the sorting system 300. This equipment typically includes a processing unit 114 or control unit for controlling the conveyor system 108, the sorting device 112, and the equipment within the housing 105. The processing unit 114 is typically used to determine one or more characteristics of the object 2 based on measurements performed by the equipment within the housing 105.

[0119] Those skilled in the art will recognize that the present invention is by no means limited to the embodiments described above. Features of the embodiments can be combined in different ways, and many variations and modifications are possible within the scope of the appended claims. The word "comprising" does not exclude other elements or steps, and the indefinite articles "a" and "an" preceding an element do not exclude the presence of a plurality of such elements.

[0120] List of Terms for Implementation

[0121] Clause 1. An inspection system configured to detect and analyze materials arranged in an inspection area, the inspection system comprising: - An irradiation device for emitting light radiation within a first predetermined wavelength range, such as UV, VIS, MIR, and / or NIR, to irradiate materials. - A detector system having at least one detector adapted to receive and detect optical radiation within a second predetermined wavelength range, such as UV, VIS, MIR, and / or NIR, which is reflected, scattered, and / or emitted by a material. - Optical device for redirecting light radiation reflected, scattered, and / or emitted by a material toward at least one detector. - White reference target element, and - Switching element, including at least one inspection area, at least one black reference area, and at least one white reference area. The switching element is arranged to rotate about a rotation axis between at least one inspection position, at least one black reference position, and at least one white reference position, such that: - At each of the at least one inspection positions of the switching element, at least one corresponding inspection area in at least one inspection zone transmits light radiation originating from the material and redirected by the optical device toward the detector system. - At each of the at least one black reference positions of the switching element, the switching element blocks at least a majority of light radiation originating from the material to prevent it from reaching the detector system, and a corresponding black reference area in at least one black reference area faces at least one detector. - At each of the at least one white reference positions of the switching element, the switching element blocks at least most of the light radiation originating from the material to prevent it from reaching the detector system, and a corresponding white reference area in at least one white reference area redirects the light radiation originating from the white reference target element and transmits it to the detector system.

[0122] Clause 2. The inspection system according to Clause 1, wherein the switching element includes a board and wherein: - Each inspection area is an opening or window in the plate. - Each black reference area is the opaque portion of the board, and - Each white reference area includes an opening or optical window in the plate and an associated reflective element, the associated reflective element including a reflective surface, the reflective element being arranged such that, at at least one white reference position of the switching element, the reflective element blocks light radiation from the material to prevent it from reaching the detector system, and the reflective surface of the reflective element redirects light radiation originating from the white reference target element toward the opening or window of the white reference area to be transmitted to the detector system.

[0123] Clause 3. The inspection system according to Clause 2, wherein the switching element includes at least two white reference areas, each white reference area including an optical window including a filter, and the at least two white reference areas are preferably arranged in pairs relative to the axis of rotation in a radially opposite manner to each other.

[0124] Clause 4. The inspection system according to any one of the preceding clauses, wherein: - At least one white reference position includes at least a first white reference position and a second white reference position. - The white reference target element includes at least a first part and a second part. - At least one white reference region includes a first white reference region and a second white reference region. Furthermore, the switching element is arranged such that, - When positioned at the first white reference location of the switching element, the first white reference region redirects the light radiation originating from the first portion of the white reference target element and transmits it towards the detector system, and - When positioned at the second white reference location of the switching element, the second white reference region redirects the light radiation originating from the second part of the white reference target element and transmits it toward the detector system.

[0125] Clause 5. The inspection system pursuant to any one of Clauses 1 to 4, The switching element includes at least two inspection areas, at least two black reference areas, and at least two white reference areas. Each inspection area, each black reference area, and each white reference area are arranged radially relative to another inspection area, another black reference area, and another white reference area, respectively, with respect to the axis of rotation.

[0126] Clause 6. The inspection system according to Clause 5, wherein the switching element is arranged such that all planes containing the axis of rotation divide the switching element into two parts of substantially equal mass.

[0127] Clause 7. The inspection system according to any one of Clauses 2 to 6, wherein the reflective element of each white reference area extends from the main plane of the plate such that the normal of the reflective surface forms an angle of 10° to 85°, or 20° to 75°, or 30° to 65°, or 40° to 50° relative to the main plane.

[0128] Clause 8. The inspection system according to any one of the preceding clauses, wherein the switching element further includes at least one or more encoder elements associated with the area, the encoder elements being used in operation to identify the inspection area, the black reference area, or the white reference area.

[0129] Clause 9. The inspection system according to any one of the preceding clauses, wherein the white reference target element is arranged to be irradiated by the irradiation device.

[0130] Clause 10. The inspection system according to any one of the preceding clauses, wherein the detector system is a spectral measurement system.

[0131] Clause 11. A method for calibrating an inspection system configured to detect and analyze materials arranged in an inspection area, the inspection system comprising: - A detector system having at least one detector adapted to receive and detect light radiation originating from a material, and - Switching element, including at least one inspection area, at least one black reference area, and at least one white reference area. The method includes: The steps include rotating the switching element to the inspection position of the calibration element and receiving light radiation originating from the material and transmitted through at least one inspection area of ​​the switching element via at least one detector. The steps include rotating the switching element to its black reference position, such that the switching element blocks at least most of the light radiation originating from the material to prevent it from reaching the detector system, and measuring the black reference level in at least one black reference region of the switching element. The steps of rotating the switching element to the white reference position of the switching element such that the switching element blocks at least most of the light radiation originating from the material to prevent it from reaching the detector system, and measuring the white reference level on the white reference target element, wherein the light radiation originating from the white reference target element is redirected by at least one white reference area of ​​the switching element and transmitted toward the detector system.

[0132] Clause 12. A sorting system for sorting objects, comprising: - An upstream conveying device and at least a first downstream conveying device and a second downstream conveying device, wherein each of the upstream conveying device and at least the first downstream conveying device and the second downstream conveying device includes at least one of a conveyor belt, a chute, or a free-fall path. - An analysis device configured to analyze and determine at least one characteristic of an object being transported on an upstream conveying device. - Sorting device, configured as follows: o According to a first criterion and a second criterion based on at least one characteristic, sort objects into at least one of a first category and a second category, and The first downstream conveyor provides objects sorted into the first category, and the second downstream conveyor provides objects sorted into the second category. - The inspection system according to any one of clauses 1 to 10 is arranged such that the inspection area overlaps with at least a portion of the first downstream conveying device, wherein the inspection system is configured to: o Determine at least one characteristic of the object in the inspected area, o Determine whether at least one characteristic of an object in the inspected area satisfies a first criterion, and A quality score is established based on the ratio of the number of times an object passing through the inspection area satisfies at least one characteristic of the first criterion to the number of times at least one characteristic of the object passing through the inspection area is determined.

Claims

1. An inspection system, wherein, The inspection system is configured to detect and analyze materials arranged in the inspection area, the inspection system comprising: - An irradiation device for emitting light radiation within a first predetermined wavelength range, such as UV, VIS, MIR, and / or NIR, to irradiate the material. - A detector system having at least one detector adapted to receive and detect characteristic radiation within a second predetermined wavelength range, such as UV, VIS, MIR, and / or NIR, said characteristic radiation being light radiation reflected, scattered, and / or emitted by the material. - A switching element, arranged to rotate about a rotation axis between at least one inspection position, at least one black reference position, and at least one white reference position. - A white reference target element, configured to be irradiated by reference radiation and configured to redirect the reference radiation toward the switching element, the reference radiation being light radiation emitted by the irradiation device, and - Optical device for redirecting the characteristic radiation toward the switching element. The switching element includes a board, and the board includes: - At least one inspection area, each of said inspection areas being an opening or window in the plate. - At least one black reference area, each of said black reference areas being an opaque portion of said plate, and - At least one white reference area, each of the white reference areas including an opening or optical window in the plate and an associated reflective element, the associated reflective element including a reflective surface, the reflective element being arranged such that at the at least one white reference position of the switching element, the reflective surface of the reflective element is irradiated by the reference radiation and redirects the reference radiation toward the detector system, and the reflective element blocks the characteristic radiation from reaching the detector system. The switching element is arranged to rotate about the rotation axis, such that: - At each of the at least one inspection positions of the switching element, a corresponding inspection area of ​​the at least one inspection region allows the characteristic radiation already redirected by the optical device to be transmitted, and transmits the characteristic radiation toward the detector system. - At each of the at least one black reference positions of the switching element, a corresponding black reference region in the at least one black reference region blocks all or at least most of the characteristic radiation from reaching the detector system. - At each of the at least one white reference positions of the switching element, a corresponding associated reflective element associated with the corresponding white reference region is configured to be irradiated by the characteristic radiation, and the associated reflective element is configured to block the characteristic radiation from reaching the detector system. The reflective surface of the corresponding associated reflective element is configured to be irradiated by the reference radiation and redirect the reference radiation toward the corresponding white reference region, and the opening or optical window of the corresponding white reference region is configured to transmit the reference radiation toward the detector system.

2. The inspection system according to claim 1, wherein, The switching element includes at least two white reference areas, each white reference area including an optical window, the optical window including a filter, and the at least two white reference areas are preferably arranged in pairs with respect to the rotation axis in a radially opposite manner to each other.

3. The inspection system according to any one of the preceding claims, wherein: - The at least one white reference position includes at least a first white reference position and a second white reference position. - The white reference target element includes at least a first part and a second part. - The at least one white reference region includes a first white reference region and a second white reference region. Furthermore, the switching element is arranged such that, - When positioned at the first white reference location of the switching element, the first white reference region will be redirected by the reference radiation redirected by the first portion of the white reference target element and transmitted toward the detector system, and When positioned at the second white reference location of the switching element, the second white reference region will be redirected by the reference radiation redirected by the second portion of the white reference target element and transmitted toward the detector system.

4. The inspection system according to any one of claims 1 to 3, in, The switching element includes at least two inspection areas, at least two black reference areas, and at least two white reference areas, and Each inspection area, each black reference area, and each white reference area are arranged radially opposite to another inspection area, another black reference area, and another white reference area, respectively, relative to the rotation axis.

5. The inspection system according to claim 4, wherein, The switching element is arranged such that all planes containing the axis of rotation divide the switching element into two parts of substantially equal mass.

6. The inspection system according to any one of the preceding claims, wherein, The reflective element of each white reference area extends from the main plane of the plate such that the normal of the reflective surface forms an angle of 10° to 85°, or 20° to 75°, or 30° to 65°, or 40° to 50° relative to the main plane.

7. The inspection system according to any one of the preceding claims, wherein, The switching element further includes at least one or more encoder elements associated with the area, the encoder elements being used in operation to identify the inspection area, the black reference area, or the white reference area.

8. The inspection system according to any one of the preceding claims, wherein, The detector system is a spectral measurement system.

9. A method for calibrating an inspection system configured to detect and analyze materials arranged in an inspection area, the inspection system comprising: - An irradiation device for emitting light radiation within a first predetermined wavelength range, such as UV, VIS, MIR, and / or NIR. - A detector system having at least one detector adapted to receive and detect characteristic radiation, said characteristic radiation being light radiation reflected, scattered, and / or emitted by said material, and - A switching element, arranged to rotate about a rotation axis between at least one inspection position, at least one black reference position, and at least one white reference position, wherein the switching element comprises a plate, the plate including: at least one inspection area, each inspection area being an opening or window in the plate; at least one black reference area, each black reference area being an opaque portion of the plate; and at least one white reference area, each white reference area including an opening or optical window in the plate and an associated reflective element, the associated reflective element including a reflective surface. - White reference target element, and - Optical device for redirecting the characteristic radiation toward the switching element. The method includes: The material is irradiated by light radiation within a first predetermined wavelength range, such as UV, VIS, MIR, and / or NIR, emitted by the irradiation device. The optical device redirects the characteristic radiation toward the switching element. The step of rotating the switching element to the inspection position of the switching element includes receiving the characteristic radiation from the optical device and transmitting the characteristic radiation through a corresponding inspection area in at least one inspection area of ​​the switching element, and then receiving it by the at least one detector. The step of rotating the switching element to the black reference position of the switching element, wherein a corresponding black reference region in the at least one black reference region blocks all or at least most of the characteristic radiation from reaching the detector system, and the at least one detector measures the black reference level on the corresponding black reference region in the at least one black reference region of the switching element. The step of rotating the switching element to the white reference position of the switching element and illuminating the white reference target element with reference radiation, wherein the reference radiation is light radiation emitted by the illuminating device, wherein the reflective element of the corresponding white reference region in the at least one white reference region blocks at least a majority of the characteristic radiation from reaching the detector system, and the reference radiation: Redirected from the white reference target element toward the switching element, Then the reflective surface of the reflective element is redirected toward the detector system, and Then, the light is transmitted toward the detector system through the opening or optical window of the corresponding white reference region in the at least one white reference region, and The white reference level is measured on the white reference target element by the at least one detector.

10. A sorting system for sorting objects, comprising: - An upstream conveying device and at least a first downstream conveying device and a second downstream conveying device, wherein each of the upstream conveying device and the at least first downstream conveying device and the second downstream conveying device includes at least one of a conveyor belt, a chute, or a free-fall path. - An analysis device configured to analyze and determine at least one characteristic of the object being transported on the upstream conveying device. - Sorting device, configured as follows: o According to a first criterion and a second criterion based on at least one of the at least one characteristic, the objects are sorted into at least one of a first category and a second category, and The object sorted into the first category is provided to the first downstream conveyor, and the object sorted into the second category is provided to the second downstream conveyor. - The inspection system according to any one of claims 1 to 8 is arranged such that the inspection area overlaps with at least a portion of the first downstream conveying device, wherein the inspection system is configured to: o Determine at least one characteristic of the object passing through the inspection area. o Determine whether at least one characteristic of the object passing through the inspection area satisfies the first criterion, and A quality score is established based on the ratio between the number of times that at least one characteristic of an object passing through the inspection area satisfies the first criterion and the number of times that at least one characteristic of an object passing through the inspection area is determined.

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