Temperature-resistant calibration path optics design

Abstract

A spectrometer device (110) for obtaining spectroscopic information regarding at least one object (112), the spectrometer device (110) comprising: - at least one detector (116) for detecting detection light (118) from the object (112); - at least one optical filter (120) configured to transfer incident light within at least one selected wavelength range to the detector (116), the transmission profile of the optical filter (120) being dependent on the angle of incidence, the at least one optical filter (120); - at least one light source (124) configured to emit irradiation light (126) within at least one optical spectrum range; - at least one sample interface (130) configured to enable the irradiation light (126) to irradiate the object (112) and to enable light from the object (112) to propagate to the detector (116) via the optical filter (120); - at least one first optical path (132), the first optical path (132) being configured such that the irradiation light (126) passes through the sample interface (130) at least once and thereby propagates to the detector (116) via the optical filter (120), the optical filter (120) having a first transmission profile T 1,NBP for the first optical path (132); - at least one internal calibration target (134) and at least one second optical path (136), the second optical path (136) being configured such that the irradiation light (126) interacts with the internal calibration target (134) at least once and thereby propagates to the detector (116) via the optical filter (120), the optical filter (120) having a second transmission profile T 1,NBP for the second optical path (136); comprising The transmission profiles of the optical filters (120) of the first optical path (132) and the second optical path (136) are relative to each other. 1,NBP (λ) = d·T 2,NBP A spectrometer (110) in which (λ) is proportional and d does not depend on one or more of temperature, wavelength, or angle of incidence.

Description

[Technical Field]

[0001] The present invention relates to a spectrometer, a method for calibrating the spectrometer, and a method for determining at least one spectral piece of information of at least one object using the spectrometer. Furthermore, the present invention relates to a computer program for performing the calibration method of the spectrometer and a computer-readable storage medium. Such methods and apparatus can generally be used for investigation or monitoring purposes, particularly in the infrared (IR) spectral region, especially in the near-infrared (NIR) spectral region, and in the visible (VIS) spectral region. However, further applications are possible. [Background technology]

[0002] In general, spectrometers are known to collect information about the spectral optical composition of an object when it is irradiated with, reflected, and / or absorbed with light. Spectrometers need to be calibrated so that spectra from multiple spectrometers can be compared. Generally, spectrometers require calibration of wavelength or wavenumber (e.g., x-axis calibration of the recorded spectrum) and calibration of signal, reflectance, transmittance, and / or absorbance (i.e., y-axis calibration of the recorded spectrum). For example, y-axis calibration of the recorded spectrum in reflectance measurements, which is commonly required in the field of diffuse reflectance near-infrared spectroscopy, may be performed using an external reflectance standard placed at the sample position. Alternatively, calibration may be performed using an internal calibration target that is automatically moved into the measurement field by the spectrometer itself to calibrate the spectrometer's response.

[0003] However, in the field of mobile spectroscopy, the use of external calibration standards and / or movable internal calibration targets may not be feasible. Therefore, calibration schemes are known that place external calibration standards at the sample position and / or do not require movable internal calibration targets. These calibration schemes may utilize internal calibration pathways.

[0004] US2017 / 153142A1 describes a method and apparatus for a spectrometer to measure the spectrum of an object. In many cases, one or more of the calibration cover, accessories, or the spectrometer are each associated with a unique identifier and corresponding calibration data. The calibration data associated with the unique identifier can be stored in a database used to determine spectral information from measurements of an object obtained with an individual spectrometer device. The spectrum of the object can be determined according to the unique identifier and the associated calibration data.

[0005] US2022 / 187124A1 describes an optical measurement device including a light source; a emission optical system configured to guide a first portion of the light generated by the light source to a measurement target; a condensing optical system configured to receive light from the measurement target; a light guide tube configured to guide a second portion of the light generated by the light source to a spectral reference; a spectral reference; a sensor; and a filter. A first portion of the filter can be provided between the condensing optical system and a first portion of the sensor. A second portion of the filter can be provided between the spectral reference and a second portion of the sensor.

[0006] Despite the advantages achieved by known methods and apparatuses, some technical problems remain. Generally, the calibration of a spectrometer aims for a constant c i =S 1,i / S 2,i =const, where c i refers to the calibration coefficient of the filter at wavelength λ i . If the calibration constant c i is not constant, the calibration of the spectrometer usually fails. In a calibration scheme using an internal calibration path, the calibration coefficient can generally be determined using signals S1 and S2 that depend on the spectral emission beam of a light source Φ Light that depends on temperature. Further, the signals are the reflectance R ext of an external reflection target in an external path, the reflectance R int of an internal reflection target in an internal path, as well as the transmittance T 2,filter of an optical filter in an external path and the transmittance T of an optical filter in an internal path1,filter It may depend on:

number

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[0007] Therefore, light source Φ Light The spectral radiant flux is weighted differently as the spectral radiant flux changes with temperature. Due to this different weighting, R ext ≠R int and / or T 1,filter ≠T 2,filter In either of these cases, a change in the calibration coefficient c may occur. Therefore, when using a temperature-dependent light source in a spectrometer in combination with an angle-of-incident (AOI)-dependent optical filter, temperature changes can cause drift in the spectrometer's calibration coefficient. Specifically, this drift in the calibration coefficient may involve temperature changes in the ratio of light through the internal and external paths. As a result, this drift in the calibration coefficient can cause temperature-induced drift in the recorded spectrum. This can be particularly significant if the temperature dependence of the light source varies across its emission spectrum. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] US2017 / 153142A1 [Patent Document 2] US2022 / 187124A1 [Overview of the project] [Problems that the invention aims to solve]

[0009] Therefore, it is desirable to provide a method and apparatus that at least partially solves the above-mentioned technical problems of known methods and apparatuses. Specifically, it is desirable to provide a spectrometer apparatus and a calibration method for a spectrometer apparatus that enable temperature-robust internal calibration. [Means for solving the problem]

[0010] This problem is solved by a spectrometer apparatus having the features of an independent patent claim, by a method for calibrating the spectrometer apparatus, by a method for determining at least one spectroscopic piece of information, and by a computer program and a computer-readable storage medium for performing these methods. Advantageous embodiments that can be realized in any single aspect or in any combination are described in the dependent claims and throughout the specification.

[0011] In a first aspect of the present invention, a spectrometer device for acquiring spectral information relating to at least one object is disclosed.

[0012] As used herein, the term “spectrometer” is a broad term and should be given its usual and conventional meaning to those skilled in the art, and should not be limited to any special or customized meaning. The term may, in particular, refer to an optical device configured to acquire at least one item of spectral information relating to at least one object. Specifically, at least one item of spectral information may refer to at least one optical property or optically measurable property determined as a function of wavelength at one or more different wavelengths. More specifically, the optical property or optically measurable property, and at least one item of spectral information, may relate to at least one property characterizing at least one of transmission, absorption, reflection, or emission, either by the object itself or after irradiation by external light. At least one optical property may be determined for one or more wavelengths. Specifically, a spectrometer can form a device capable of recording signal intensity with respect to a corresponding wavelength or band of the spectrum, e.g., a wavelength interval, where the signal intensity may be provided specifically as an electrical signal that can be used for further evaluation.

[0013] A spectrometer may be, or may be equipped with, a device that enables the measurement of at least one spectrum (e.g., the measurement of spectral radiant flux as a function of wavelength or detection wavelength). The spectrum may be acquired, for example, in absolute units or relative units (e.g., in relation to at least one reference measurement). Thus, for example, the acquisition of at least one spectrum may be performed, in particular, for the measurement of spectral radiant flux (unit: W / nm) or for the measurement of a spectrum against at least one reference substance (unit: 1), which can describe the properties of the substance, such as reflectance with respect to wavelength. Additionally or alternatively, the reference measurement may be based on a reference light source, an optical reference path, a calculated reference signal (e.g., a calculated reference signal from literature), and / or a reference device.

[0014] The spectrometer may be a diffuse reflectance spectrometer configured to acquire spectral information from light diffusely reflected by at least one object (e.g., at least one sample). Additionally or alternatively, at least one spectrometer may be an absorption spectrometer and / or a transmission spectrometer, or may include both. In particular, spectral measurements by the spectrometer may include reflectance measurements in a reflectance configuration. Specifically, the spectrometer may be configured to perform reflectance measurements in a reflectance configuration. However, as mentioned above, other types of spectrometers are also possible.

[0015] The spectrometer may comprise at least one light source, as will be outlined in more detail below, for example, at least one of a tunable light source, a light source having at least one fixed emission wavelength, and a broadband light source. The spectrometer may further comprise at least one detector device configured to detect light, such as at least one of light transmitted, reflected, or emitted from at least one object, as will be outlined in more detail below. The spectrometer may comprise at least one wavelength-selective element, such as a diffraction grating, a prism, and an optical filter (for example, a variable-length filter having transmission characteristics that vary over its lateral extension), as will be outlined in more detail below. The wavelength-selective element may be used to separate incident light into the spectrum of constituent wavelength signals, and the intensity of each signal of the constituent wavelength signals is determined by employing a detector, such as a detector having a detector array, as will be outlined in more detail below.

[0016] The spectrometer may specifically be a portable spectrometer. For example, the portable spectrometer may be part of a mobile device, or it may be attachable to a mobile device such as a notebook computer, tablet, mobile phone (smartphone, etc.), smartwatch, and / or wearable computer.

[0017] As used herein, the term “spectroscopic information” is also called “spectral information” or “an item of spectral information” and is a broad term that should be given a common and conventional meaning to those skilled in the art, and should not be limited to any special or customized meaning. The term may, without limitation, specifically refer to an item of information relating to radiation emitted by at least one object and / or at least one object, which characterizes at least one optical property of the object, more specifically, at least one item of information that characterizes at least one of the transmission, absorption, reflection and emission of at least one object, for example, qualitatively and / or quantitatively. As an example, at least one item of spectral information may include information relating to the intensity of light transmitted, absorbed, reflected or emitted by an object, for example, as a function of at least one intensity piece of information, for example, one wavelength, or a subrange of wavelengths over one or more wavelengths, such as over a wavelength range. Specifically, intensity information corresponds to, or can be derived from, signal intensity, specifically signal intensity recorded by a spectrometer with respect to the wavelength or wavelength range of the spectrum, in particular an electrical signal.

[0018] A spectrometer may be configured to acquire at least one spectrum or at least a portion of a spectrum of detected light propagating from an object to the spectrometer. The spectrum can describe the radiative unit of spectral radiance, for example, in units of watts per nanometer (W / nm) or other units, such as a function of the wavelength of the detected light. Thus, the spectrum can describe the optical output of light in a specific wavelength band in the near-infrared (NIR) spectral range, for example. The spectrum may include one or more optical variables (e.g., power spectral density, electrical signals obtained by optical measurement, etc.) as a function of wavelength. The spectrum can show, for example, the power spectral density and / or spectral radiance of an object, particularly a sample, relative to a reference sample, such as the transmittance and / or reflectance of the object, particularly a sample.

[0019] A spectrometer may be configured to acquire spectra in a wavelength range that at least partially includes one or more of the infrared, visible, and ultraviolet spectral ranges. The spectrometer may be a near-infrared spectrometer. For example, a spectrometer may be configured to acquire spectra in a wavelength range that at least partially includes the near-infrared spectral range, for example, the wavelength range from 760 nm to 5 μm, specifically the wavelength range from 1 μm to 3 μm.

[0020] The spectrum may include, for example, at least one measurable optical variable or property of the detected light and / or object, particularly as a function of the irradiated light and / or detected light. For example, the at least one measurable optical variable or property may include at least one radiometric quantity, such as spectral density, power spectral density, spectral flux, radiant flux, radiant intensity, spectral radiant intensity, irradiance, or spectral irradiance. Specifically, as an example, a spectrometer, particularly a detector, may have watts per square meter (W / m²). 2 Illuminance is expressed in watts per square meter per nanometer (W / m²). More specifically, in watts per square meter per nanometer (W / m²). 2 The spectral irradiance can be measured in watts per nanometer (W / nm). Based on the measured quantity, the spectral radiant flux in watts per nanometer (W / nm) and / or radiant flux in watts (W) can be determined (e.g., calculated) by taking into account the detector area.

[0021] As used herein, the term “object” is a broad term and should be given its usual and idiomatic meaning to those skilled in the art, and should not be limited to any special or customized meaning. Specifically, the term can refer to any object selected from living and non-living things. Thus, as an example, at least one object may include one or more articles and / or one or more parts of articles, and such at least one article or at least one part may include at least one component that can provide a spectrum suitable for investigation. Additionally or alternatively, an object may be, or include, one or more living things and / or one or more parts thereof, a human, e.g., a user, and / or one or more body parts of an animal. Specifically, an object may include one or more samples that can be analyzed completely or partially by spectroscopy. For example, an object may be, or include: human or animal skin; edible items such as fruit; and at least one of plastics and textile products.

[0022] A spectrometer apparatus comprises at least one detector for detecting detection light from an object. The term “detect” as used herein is a broad term and should be given its usual and idiomatic meaning to those skilled in the art, and should not be limited to any special or customized meaning. Specifically, the term may refer to at least one process of qualitatively and / or quantitatively determining, measuring, and monitoring at least one parameter, such as a physical parameter, a chemical parameter, or a biological parameter. Specifically, a physical parameter may be an electrical parameter or may include electrical parameters. Accordingly, the term “detector” as used herein is a broad term and should be given its usual and idiomatic meaning to those skilled in the art, and should not be limited to any special or customized meaning. Specifically, the term may refer to any apparatus configured to qualitatively and / or quantitatively detect, i.e., determine, measure, and monitor at least one parameter, such as at least one of a physical parameter, a chemical parameter, or a biological parameter. The detector may be configured to generate at least one detector signal, more specifically at least one electrical detector signal (such as an analog detector signal and / or a digital detector signal), the detector signal providing information about at least one parameter measured by the detector. The detector signal may be provided directly or indirectly by the detector to at least one evaluation unit, and the detector and evaluation unit may be connected directly or indirectly. The detector signal may be used as a “raw” detector signal and / or may be used after being processed or preprocessed by filtering, etc. Thus, the detector may include at least one processing unit and / or at least one preprocessing unit, e.g., at least one of an amplifier, an analog-to-digital converter, and an electrical filter.

[0023] In this case, the detector is configured to detect light propagating from an object to a spectrometer, more specifically to the detector of the spectrometer, which is referred to as "detection light" according to the nomenclature described above. Specifically, the detector is at least one photodetector or may comprise at least one photodetector. The photodetector may be configured to determine at least one optical parameter, such as the intensity and / or output of light irradiated onto at least one sensitive area of ​​the detector. More specifically, the photodetector may comprise at least one photosensitive element and / or at least one photosensor, such as a photodiode, photocell, photoresistor, phototransistor, thermoelectric sensor, photoacoustic sensor, pyroelectric sensor, photomultiplier tube, and bolometer. Thus, the detector may be configured to generate at least one detector signal, more specifically at least one electrical detector signal in the sense described above, and to provide information about at least one optical parameter, such as the output and / or intensity of light irradiated onto the detector or the sensitive area of ​​the detector.

[0024] The detector may comprise a single optically sensitive element or area, or multiple optically sensitive elements or areas. Specifically, the detector may comprise at least one detector array, more specifically an array of photosensitive elements, or comprise both. Each photosensitive element may comprise at least one photosensitive area adapted to generate an electrical signal in response to the intensity of incident light, which may be provided to an evaluation unit, in particular, as outlined in more detail below.

[0025] The photosensitive region included by each photosensitive element may be a single, uniform photosensitive region configured to receive incident light irradiated onto each individual photosensitive element. However, other arrangements of photosensitive elements are also possible.

[0026] An array of photosensitive elements may be designed to generate a detector signal, preferably an electronic signal, related to the intensity of incident light irradiated onto each individual photosensitive element. The detector signal may be an analog and / or digital signal. Thus, the electronic signals of adjacent pixelated sensors may be generated simultaneously or sequentially in time. For example, during row scanning or line scanning, it is possible to generate a sequence of electronic signals corresponding to a series of individual photosensitive elements arranged in a row. Furthermore, each individual photosensitive element may preferably be an active pixel sensor adaptable to amplify the electronic signal before supplying it to an evaluation unit. For this purpose, the detector may include one or more signal processing devices, such as one or more filters and / or analog-to-digital converters, for processing and / or preprocessing the electronic signal.

[0027] If the detector includes an array of photosensitive elements, the detector can be selected, for example, from any known pixel sensor, particularly from pixelated organic camera elements, preferably from pixelated organic camera chips, or from pixelated inorganic camera elements, preferably from pixelated inorganic camera chips, more preferably from CCD chips or CMOS chips, which are currently commonly used in various cameras. Alternatively, the detector is generally a photoconductor, particularly an inorganic photoconductor, particularly PbS, PbSe, Ge, InGaAs, extended InGaAs, InSb, or HgCdTe, or may include these. Further alternatively, it may include at least one of pyroelectric, bolometer, or thermoelectric detector elements. Thus, a camera chip having a 1×N pixel or M×N pixel matrix can be used here, for example, where M is less than 10 and N is in the range of 1 to 50, preferably in the range of 2 to 20, more preferably in the range of 5 to 10. Furthermore, a monochrome camera element, preferably a monochrome camera chip, can be used, and this monochrome camera element may be selected to have different wavelengths for each photosensitive element, particularly according to the series of the photosensor. The array can be adapted to provide multiple electrical signals that can be generated by the photosensitive regions of the photosensitive elements comprising the array. The electrical signals provided by the array in the spectrometer can be transferred to an evaluation unit.

[0028] The spectrometer apparatus comprises at least one optical filter configured to transfer incident light within at least one selected wavelength range to a detector, wherein the transmission profile of the optical filter depends on the angle of incidence. The term “optical filter” as used herein is a broad term and should be given in a common and conventional sense to those skilled in the art, and should not be limited to any special or customized meaning. Specifically, the term may refer to any optical element configured to selectively transmit light having different wavelengths. Specifically, an optical filter may be configured to transmit light having wavelengths within at least one selected wavelength range, where the transmission of light having wavelengths outside the selected wavelength range can be prevented at least partially, such as by reducing the transmittance outside the selected wavelength range compared to the transmittance within the selected wavelength range. Therefore, the term “selected wavelength range” as used herein is a broad term and should be given in a common and conventional sense to those skilled in the art, and should not be limited to any special or customized meaning; specifically, the term may refer to at least one wavelength range that the optical filter allows the transmission of light. For example, light having wavelengths within a selected wavelength range can pass through the optical filter, while light having wavelengths outside the selected wavelength range may be at least partially blocked, such as by a decrease in light intensity after passing through the optical filter. The optical filter may include at least one filter selected from the group consisting of interference filters, absorption filters, dichroic filters, and MEMS Fabry-Perot interferometers. Specifically, the optical filter may include at least one narrowband-pass filter, or more specifically, a set of narrowband-pass filters. The narrowband-pass filter may be configured to transmit only light within a narrowly selected wavelength range, such as, for example, the range from 10 to 100 nm, specifically the range from 10 to 50 nm, more specifically a wavelength range with a width of 20 nm, or most specifically a wavelength range with a width of 15 nm. For example, in a set of narrowband-pass filters, each narrowband-pass filter may have a narrowband-selective wavelength range that is at least partially different from one another.

[0029] As used herein, the term “transmission profile” is a broad term and should be given its usual and conventional meaning to those skilled in the art, and should not be limited to any special or customized meaning. Specifically, the term may refer to transmittance as a function of wavelength, without limitation. Specifically, a transmission profile can indicate the light transmission capability of an optical filter as a function of wavelength. A transmission profile may include a numerical representation of the light transmission capability of an optical filter as a function of wavelength. For example, a transmission profile may include a numerical representation that quantifies the portion of transmitted light that passes through the optical filter for each wavelength within a selected wavelength range. Specifically, a transmission profile may include a ratio that quantifies the amount of light transmitted by the optical filter to the amount of incident light. For example, a transmission profile may include a ratio that quantifies the output of light transmitted by the optical filter compared to the output of incident light. Specifically, a transmission profile may have wavelength dependence, such as having different transmission ratios for different wavelengths of incident light.

[0030] The transmission profile of an optical filter depends on the angle of incidence. As used herein, the term “angle of incidence” is broad and should be given its usual and conventional meaning to those skilled in the art, and should not be limited to any special or customized meaning. Specifically, the term may refer, without limitation, to the angle at which incident light is incident on the normal to the surface of an optical element. The surface normal may refer to the direction perpendicular to a particular surface. Specifically, the angle of incidence may be the angle of incident light with respect to the surface normal of the surface of the optical filter.

[0031] The spectrometer further comprises at least one light source configured to emit light in at least one optical spectral range. The term “light” as used herein is a broad term and should be given in a common and conventional sense to those skilled in the art, and should not be limited to any special or customized meaning. Specifically, the term may refer, without limitation, to electromagnetic radiation in one or more of the infrared spectral range, the visible spectral range, and the ultraviolet spectral range. Here, the term “ultraviolet spectral range” generally refers to electromagnetic radiation having wavelengths from 1 nm to 380 nm, preferably from 100 nm to 380 nm. Furthermore, in part in accordance with the version of the standard ISO-21348 effective as of the date of this document, the term “visible spectral range” generally refers to the spectral range from 380 nm to 760 nm. The term "infrared spectral range" (IR) generally refers to electromagnetic radiation from 760 nm to 1000 μm, with the range from 760 nm to 1.5 μm usually denoted as the "near-infrared spectral range" (NIR), the range from 1.5 μm to 15 μm as the "mid-infrared spectral range" (MidIR), and the range from 15 μm to 1000 μm as the "far-infrared spectral range" (FIR). Preferably, the light used for typical purposes of the present invention is light in the infrared (IR) spectral range, more preferably near-infrared (NIR) and / or mid-infrared spectral range (MidIR), particularly light with wavelengths from 1 μm to 5 μm, preferably 1 μm to 3 μm. This is due to the fact that many material properties or chemical compositional properties of objects can be obtained from the near-infrared spectral range. However, it should be noted that spectroscopy in other spectral ranges is also possible and falls within the scope of the present invention.

[0032] Therefore, the term “light source” as used herein is a broad term and should be given the usual and conventional meaning to those skilled in the art, and should not be limited to any special or customized meaning. Specifically, the term may refer to any device configured to generate or provide light as defined above, without limitation. Specifically, a light source may be or include at least one electric light source, such as an electrically driven light source. For example, a light source may comprise at least one light-emitting diode (LED).

[0033] In spectroscopy, it is necessary to distinguish between various light sources and light paths. In the context of this invention, first, the light propagating from the light source to the object is referred to as "irradiation light." Next, the light propagating from the object to the detector is referred to as "detection light." Detection light can include at least one of the following: irradiation light reflected by the object, irradiation light scattered by the object, irradiation light transmitted by the object, and emission light generated by the object, such as phosphorescence or fluorescence generated by the object after optical, electrical, or acoustic excitation of the object by the irradiation light. Therefore, detection light can be generated directly or indirectly through the irradiation of the object with the irradiation light.

[0034] As used herein, the term “spectral range” is a broad term and should be given its usual and conventional meaning to those skilled in the art, and should not be limited to any special or customized meaning. Specifically, the term may refer, without limitation, to a wavelength range that includes one or more of the infrared, visible, and ultraviolet spectral ranges defined above.

[0035] The irradiated light has an optical spectral range that is at least partially located in the near-infrared spectral range. For example, the optical spectral range of the irradiated light can include a wavelength range from 760 nm to 5 μm, specifically a wavelength range from 1 μm to 3 μm.

[0036] The spectrometer further comprises at least one sample interface configured to allow irradiation light to irradiate an object and to allow light to propagate from the object through an optical filter to a detector. The term “sample interface” as used herein is a broad term and should be given its usual and conventional meaning to those skilled in the art, and should not be limited to any special or customized meaning. Specifically, the term may refer to, without limitation, a port of the spectrometer through which light within a specific optical spectral range, e.g., light from at least one partition or the entire optical spectral range, can be incident upon the spectrometer for the purpose of spectral detection and / or de-exit from the spectrometer for the purpose of irradiating, for example, at least one object. The sample interface can, for example, define an optical surface of the spectrometer (e.g., a material surface or a virtual surface) through which irradiation light from a first optical path can travel to an object, and / or detection light from an object can travel to a detector, for example, to generate a detector signal. The sample interface may be a virtual plane. The sample interface may or may not consist of a physical element and / or barrier, such as a transparent element, e.g., a glass or quartz window. The sample interface may be the sample surface itself, or a plane on which the sample can be placed or aligned. For example, the sample interface may be at least one element containing, or including, at least one transparent material that is transparent within the optical spectral range, e.g., at least one partition of the optical spectral range, or at least partially within the optical spectral range. The sample interface may be configured to transmit light within the optical spectral range. The sample interface is positioned in the optical path of the spectrometer, specifically in the first optical path, allowing the illumination light emitted from the light source to illuminate an object positioned in front of the spectrometer, specifically in front of the sample interface.The transparent material may include, for example, one or more glass materials such as silica, soda lime, or borosilicate, and / or polymer materials such as polymethyl methacrylate or polystyrene.

[0037] The spectrometer further comprises at least one first optical path, the first optical path configured such that the irradiated light passes through the sample interface at least once and propagates through an optical filter to the detector, the optical filter having a first transmission profile T for the first optical path 1,NBP It has.

[0038] The spectrometer further includes at least one internal calibration target and at least one second optical path, the second optical path configured to allow the irradiated light to propagate to the detector via an optical filter by interacting with the internal calibration target at least once, the optical filter having a second transmission profile T for the second optical path 2,NBP It has.

[0039] As used herein, the term “optical path” is a broad term and should be given its usual and conventional meaning to those skilled in the art, and should not be limited to any special or customized meaning. Specifically, the term may refer, without limitation, to the trajectory of light within a spectrometer. The optical path of light within a spectrometer may be affected by reflection, refraction, dispersion and / or absorption in one or more optical elements included in the spectrometer, such as lenses, prisms, mirrors, diffraction gratings, etc. The terms “first” and “second” as commonly used herein are not intended to indicate ranking or numbering, but are simply used for nomenclature.

[0040] As used herein, the term “first optical path” is a broad term and should be given its usual and conventional meaning to those skilled in the art, and should not be limited to any special or customized meaning. Specifically, the term may refer to an optical path that interacts with the irradiating light in an object, without limitation. Specifically, the detector signal obtained through the first optical path may be affected by the presence and / or absence of the object in the spectrometer, specifically in the sample interface of the spectrometer. For example, the detector signal obtained through the first optical path in which an object is applied to the spectrometer may differ from the detector signal obtained through the first optical path in which an object is not applied to the spectrometer, in particular, regardless of certain environmental conditions. In particular, the first optical path may be configured such that the irradiating light emitted from the light source can pass through the sample interface at least once and propagate to the detector via an optical filter. Specifically, the first optical path may be configured such that the irradiating light emitted from the light source can propagate to the sample interface and then propagate to the detector via an optical filter. Through a first optical path, the illumination light emitted from the light source is guided to the sample interface directly or indirectly by reflection, refraction, and / or dispersion. The first optical path may be partially located outside the spectrometer, such as outside the housing of the spectrometer. Specifically, the illumination light in the first optical path can illuminate an object located outside the spectrometer, particularly at the sample interface, after leaving the housing of the spectrometer. The first optical path may be configured to recombine (couple) the detection light reflected by the object into the spectrometer. The detection light can be guided directly from the sample interface or indirectly by reflection, refraction, and / or dispersion to an optical filter, and then to a detector. Reflection at the sample interface may include diffuse reflection. Specifically, the detection light in the first optical path that illuminates the optical filter and then the detector may be light diffusely reflected by the object. The detector may be configured to generate at least one detector signal in response to illumination by incident light through the first optical path.

[0041] As used herein, the term “passing through the sample interface” is a broad term and should be given a common and idiomatic meaning to those skilled in the art, and should not be limited to any special or customized meaning. Specifically, the term may refer, without limitation, to one or more of the following: propagation to and from the sample interface, crossing the sample interface, or interaction with the sample interface. Emitted light may be incident on the sample interface, for example, at the angle of incidence. Emitted light may interact with the sample interface and leave the sample interface, for example, at the angle of exit. The point of incidence or region to the sample interface may be on the same side as the point of exit or region from the sample interface, or on the opposite side.

[0042] As used herein, the term “second optical path” is a broad term and should be given a common and conventional meaning to those skilled in the art, and should not be limited to any special or customized meaning. Specifically, the term may refer to an optical path that does not interact with the irradiating light at an object, without limitation. Specifically, the detector signal obtained through the second optical path may be unaffected by the presence and / or absence of an object in the spectrometer. For example, the detector signal obtained through the second optical path with an object applied to the spectrometer, specifically the sample interface, may be equal to the detector signal obtained through the second optical path with no object applied to the spectrometer, specifically assuming constant environmental conditions. In particular, the second optical path may be configured so that irradiating light emitted from a light source can propagate to the detector via an optical filter without passing through the sample interface, specifically without being reflected by an object. Through the second optical path, irradiating light emitted from a light source can reach an internal calibration target, followed by an optical filter and a detector, without interacting with an object. The second optical path may be entirely located within the spectrometer, such as inside the housing of the spectrometer. The illumination light following the second optical path is emitted from the light source and can be guided directly or indirectly to an internal calibration target by reflection, refraction, and / or dispersion, etc., and then to an optical filter and detector. For example, the second optical path may include a fiber-coupled optical path that transfers light from the light source to an internal calibration target that reflects the illumination light to an optical filter. Alternatively or additionally, the second optical path may be configured to directly illuminate the internal calibration target with illumination light emitted from the light source. The detector may be configured to generate at least one detector signal in response to illumination by incident light through the second optical path.

[0043] As used herein, the term “interacting with the internal calibration target” is a broad term and should be given its usual and idiomatic meaning to those skilled in the art, and should not be limited to any special or customized meaning. Specifically, the term may refer to at least one of the processes of reflection, absorption, or transmission, without limitation.

[0044] As used herein, the term “first transmission profile” is a broad term and should be given a common and conventional meaning to those skilled in the art, and should not be limited to any special or customized meaning. Specifically, the term may refer, without limitation, to the transmission profile of an optical filter in the first optical path. Similarly, as used herein, the term “second transmission profile” may refer, without limitation, to the transmission profile of an optical filter in the second optical path. The designations “first” and “second” are used solely as names and do not imply any order or suggest the existence of further transmission profiles of further optical elements.

[0045] The transmission profiles of the optical filters in the first and second optical paths are proportional to each other, T 1,NBP (λ) = d·T 2,NBP (λ) is such that d does not depend on one or more of the temperature, wavelength, or angle of incidence.

[0046] The transmission profile of the first optical path is:

number

[0047] The transmission profile of the second optical path is:

number

[0048] Here, θ can be the angle of incidence of light relative to the surface normal of the optical filter, and T(θ, λ, λ i) can be the transmission profile of the optical filter at a given incident angle θ, and ρ i (θ) can be the angular distribution on the surface of the optical filter in the first optical path i=1 and the second optical path i=2, respectively.

[0049] Specifically, the first and second optical paths may have an angular distribution on the optical filter surface in units of 1 / degree, and the first optical path is represented by i=1 and the second optical path by i=2. i (θ) is denoted by the angular distribution ρ on the surface of the optical filter. i (θ) is,

number

number

number

[0050] As used herein, the term “calibration target” is a broad term and should be given its usual and conventional meaning to those skilled in the art, and should not be limited to any special or customized meaning. Specifically, the term may refer, without limitation, to a reference object having known (e.g., predetermined and / or predefined) interactions with light. Calibration targets can be used for calibrating spectrometer instruments.

[0051] As used herein, the term “internal calibration target” is a broad term and should be given its usual and conventional meaning to those skilled in the art, and should not be limited to any special or customized meaning. Specifically, the term may refer, without limitation, to at least one calibration target integrated into a spectrometer, specifically into the second optical path of the spectrometer. Specifically, an internal calibration target may be configured to interact with the irradiated light in a predetermined or predefined manner within the second optical path. An internal calibration target may be configured to receive the irradiated light emitted from a light source and transfer the irradiated light to an optical filter via the second optical path. In particular, an internal calibration target may be configured to ensure that the irradiated light emitted from a light source propagates to the optical filter via the second optical path by interacting with the irradiated light, for example by reflecting and / or filtering the irradiated light on the optical filter, without passing through the sample interface. The internal calibration target may include optical elements used to interact with light, such as by at least partially transmitting and / or guiding the light so that the transmitted light follows a second optical path, specifically by reflecting and / or filtering the light. In particular, the internal calibration target may include at least one of a light reflector, a mirror, a diffuse reflect target, an optical filter such as an element having optical filtering properties, and a dispersion element. Additionally or alternatively, the internal calibration target may be an active optical calibration target such as an active optical modulator. For example, the internal calibration target may be one or more of a switchable mirror, a switchable polarizing filter, such as a liquid crystal display (LCD), or a material having a switchable and / or variable refractive index (e.g., switchable and / or variable by switching and / or changing between a crystalline phase and a liquid phase), or include them. The internal calibration target may be mounted within the spectrometer instrument, for example, within the housing of the spectrometer instrument. The internal calibration target may be a calibration target built into the spectrometer instrument.

[0052] As used herein, the term “external calibration target” is a broad term and should be given a common and idiomatic meaning to those skilled in the art, and should not be limited to any special or customized meaning. Specifically, the term may refer to at least one calibration target located outside the spectrometer. Specifically, an external calibration target may be applied to the sample interface of the spectrometer, for example, by the user or the manufacturer of the spectrometer. Thus, an external calibration target may be configured to interact with the irradiated light in the first optical path in a predetermined or predefined manner. As an example, an external calibration target may include a standard reflective target having predetermined or predefined reflective properties.

[0053] The internal calibration target may include at least one pattern. The term “pattern” as used herein is broad and should be given in a common and idiomatic sense to those skilled in the art, and should not be limited to any special or customized sense. Specifically, the term may refer to any structured element, specifically any structured optical element, without limitation. The pattern may specifically be an optical element having transmission and / or reflection properties. The pattern may be positioned to partially cover the sample interface. Specifically, the pattern may be positioned to partially reflect the illumination light emitted by the light source, allowing the reflected light to propagate through the optical filter to the detector in the second optical path. The pattern may be at least one pattern selected from the group consisting of dot patterns, checkerboard patterns, or random patterns. The pattern may cover 0.1 to 50% of the surface of the sample interface, specifically 0.5 to 25%, and more specifically 1 to 10% of the surface of the sample interface. The internal calibration target, which includes a pattern, specifically allows the angular distribution of the optical filters in the first and second optical paths to be proportional to each other, for example, ρ1(θ) = e * ρ2(θ), where e is a dimensionless constant.

[0054] Alternatively or additionally, the internal calibration target may be translucent. The term “translucent” as used herein is a broad term and should be given in a common and conventional sense to those skilled in the art, and should not be limited to any special or customized meaning. Specifically, the term may refer to the property of an optical element that partially transmits incident light in at least one wavelength range, without limitation. Specifically, a translucent optical element may be configured to transmit a portion of the incident light, and the other portion of the incident light may be reflected by the translucent optical element. Specifically, the internal calibration target is at least translucent in a selected wavelength range. The internal calibration target may be positioned such that it at least partially covers the sample interface. Specifically, a translucent internal calibration target may produce an angular distribution of optical filters such that the angular distributions of the optical filters in the first and second optical paths are proportional to each other (e.g., ρ1(θ) = e*ρ2(θ), where e is a dimensionless constant).

[0055] Alternatively or additionally, the optical filter, light source, sample interface, and internal calibration target may be arranged such that the angular distribution of the first optical path on the surface of the optical filter is the mirror image angular distribution of the second optical path, or vice versa. Alternatively, the optical filter, light source, sample interface, and internal calibration target may be arranged such that the angular distribution of the first optical path on the surface of the optical filter is the diagonal mirror image angular distribution of the second optical path, or vice versa. The angular distributions of the first and second optical paths may be inversely proportional. The optical filter, light source, sample interface, and internal calibration target may be arranged such that the transmission profiles of the optical filter for the first and second optical paths are proportional to each other.

[0056]

number

[0057] Alternatively or additionally, the optical filters, light source, sample interface, and internal calibration target may be arranged such that the transmission profiles of the first and second optical paths are identical. Specifically, the optical filters, light source, sample interface, and internal calibration target may be arranged such that

number

[0058] Alternatively or additionally, the internal calibration target may be opaque. The term “opaque” as used herein is a broad term and should be given its usual and conventional meaning to those skilled in the art, and should not be limited to any special or customized meaning. Specifically, the term may refer to, without limitation, the property of an optical element that at least partially obstructs the transmission of incident light within at least one wavelength range. Specifically, an opaque optical element may have at least one wavelength range that at least partially obstructs the transmission of light, for example, by transmitting less than 10%, specifically less than 5%, and more specifically less than 1% of the intensity and / or output of the incident light. Specifically, the internal calibration target may be at least opaque in a selected wavelength range. The spectrometer may include an additional reference light source configured to illuminate the internal calibration target. Specifically, the reference light source may be embodied in the same way as the light source. The light source and the reference light source may be arranged such that the angle of incidence of light from the first optical path to the optical filter is symmetrical with respect to the angle of incidence of light from the second optical path.

[0059] A spectrometer may include at least one evaluation unit for evaluating at least one detector signal generated by a detector and for determining spectral information of an object using the detector signal. The term “evaluation unit” as used herein is a broad term and should be given in a common and idiomatic sense to those skilled in the art, and should not be limited to any special or customized sense. Specifically, the term may refer to any device or combination of devices configured to evaluate or process at least one first information item to generate at least one second information item. Thus, specifically, an evaluation unit may be configured to process at least one input signal and generate at least one output signal. The at least one input signal may include, for example, at least one detector signal provided directly or indirectly by at least one detector. As an example, an evaluation unit may be, or include, one or more integrated circuits, such as one or more application-specific integrated circuits (ASICs), and / or one or more data processing devices, such as a computer, a digital signal processor (DSP), a field-programmable gate array (FPGA), preferably one or more microcomputers and / or microcontrollers. Additional components may consist of, for example, one or more preprocessing devices and / or data acquisition devices, such as one or more devices for receiving and / or preprocessing detector signals, such as one or more AD converters and / or one or more filters, and so on. Furthermore, the evaluation unit may include one or more data storage devices. Furthermore, the evaluation unit may include one or more interfaces, such as one or more wireless interfaces and / or one or more wired interfaces.

[0060] At least one evaluation unit may be adapted to run at least one computer program, for example, at least one computer program that performs or supports the step of generating information items. For example, one or more algorithms may be implemented that perform a predetermined transformation, such as to determine spectral information about an object using at least one detector signal, for example, to determine a modified spectrum and / or to determine at least one piece of spectral information describing at least one property of the object. For this purpose, the evaluation unit may specifically comprise at least one data processing device (also called a processor), in particular an electronic data processing device that can be designed to generate desired information by evaluating detector signals. The evaluation unit may use any processing to generate the required information, for example, by computation and / or by using at least one stored and / or known relationship. Specifically, the evaluation unit may be configured to perform at least one digital signal processing (DSP) technique (in particular at least one Fourier transform) on a primary detector signal or a secondary detector signal derived therefrom. Additionally or alternatively, the evaluation unit may be configured to perform one or more further digital signal processing techniques (e.g., winding, filtering, Gerzel algorithm, cross-correlation, and autocorrelation) on the primary detector signal or the secondary detector signal derived therefrom. In addition to the detector signal, one or more further parameters and / or information items may influence the relationship. The relationship is determined or can be determined empirically, analytically, or semi-empirically. As an example, the relationship may include a model or calibration curve, at least one set of calibration curves, at least one function, or at least one combination of the aforementioned possibilities. One or more calibration curves may be stored, for example, in the form of a set of values ​​and their associated function values, for example, in a data storage device and / or table. However, alternatively or additionally, at least one calibration curve may also be stored, for example, in a parameterized form and / or as a functional equation.Individual relationships can be used to process detector signals into information items. Alternatively, at least one combined relationship can be used to process detector signals. Various possibilities exist, and they can be combined.

[0061] The spectrometer device transmits at least one wavelength λ through at least one first optical path i The detector is irradiated with light having and at least one first detector signal S 1,i The object may be configured to obtain the following. The object may include at least one external calibration target. The external calibration target may be applied by the user to the sample interface of the spectrometer. The spectrometer has at least one wavelength λ through at least one second optical path. i The detector is irradiated with light having and at least one calibration signal S 2,i The evaluation unit can be configured to obtain the first detector signal S. 1,i and calibration signal S 2,i By using this, at least one calibration information item c i The system may be configured to determine the calibration information items. The determination of the calibration information items is also called "initial calibration". Specifically, the calibration information items may be determined according to the following:

[0062]

number

[0063] As used herein, the term “calibration information item” is a broad term and should be given a common and idiomatic meaning to those skilled in the art, and should not be limited to any special or customized meaning. Specifically, the term may refer to any information item suitable for the calibration of a spectrometer, without limitation. For example, a calibration information item may include one or more of the following: wavelength calibration, dark current calibration, and intensity calibration. Calibration information items can be used to correct, adjust, and / or compensate for the measurement signal in a spectrometer. Specifically, a calibration information item may include information regarding the relationship between the measurement signal of the spectrometer and a known calibration standard, specifically an external calibration target.

[0064] Calibration information items can be determined during the initial calibration of the spectrometer (e.g., factory calibration). Furthermore, the calibration information items can be re-determined at the user site or other location by repeating the initial calibration procedure using an external calibration target. Calibration information items can be stored, for example, in the spectrometer's data storage device and / or in a data storage device accessible to the spectrometer, and can be used to determine the spectral information of an object using the spectrometer. Specifically, calibration information items can be applied to the measurement signal of the spectrometer, specifically to modify, adjust, and / or compensate the measurement signal to obtain a calibrated measurement signal, for example, to obtain a measurement signal calibrated against a known calibration standard, specifically an external calibration target. The calibrated measurement signal can directly provide the spectral information of an object, or can be used to derive the spectral information of an object.

[0065] The spectrometer device transmits at least one wavelength λ through at least one first optical path i The detector is irradiated with light having the following properties, and at least one measurement signal S meas,i It can be configured to obtain. In this example, the object may include at least one object to be measured, for example, at least one object to be investigated using a spectrometer. The spectrometer may further include at least one wavelength λ through at least one second optical path iThe detector is irradiated with light having the following properties, and at least one reference signal S ref,i The evaluation unit can be configured to obtain calibration information item c. i , reference signal S ref,i The system may be configured to determine spectral information about an object using the first detector signal and the reflectance R object,i And here,

number

[0066] In the calibration of a spectrometer (e.g., factory calibration), objects applied to the spectrometer, for example with the assistance of the user, may include an external calibration target. The reflectance R of the external calibration target... λ, ext and the reflectance R of the internal calibration target λ, int They can be in a proportional relationship with each other,

number

[0067] Reflectance R of the external calibration target λ, ext and the reflectance R of the internal calibration target λ, int These constants may be proportional to each other at each wavelength within the selected wavelength range. The constant a may be independent of temperature and / or wavelength.

[0068] External calibration targets may include standardized diffuse reflectance targets having a reflectance of over 99% (>99%) in the 400nm to 1500nm range and over 95% (>95%) in the 250nm to 2500nm range. For example, external calibration targets may include commercially available calibration targets such as Spectralon® diffuse reflectance targets. These reflectance targets may include thermally and / or chemically stable reflectance panels. These reflectance targets may include plates of white or gray material up to 24 × 24 inches mounted on a robust anodized aluminum frame. The reflectance of these reflectance targets may typically be over 99% (>99%) in the 400nm to 1500nm wavelength range and over 95% (>95%) in the 250nm to 2500nm wavelength range. Spectralon® diffuse reflectance standards are available in plates up to 24 x 24 inches with the following reflectance values: 99%, 80%, 60%, 40%, 20%, 10%, 5%, and 2% (up to 10-inch targets).

[0069] The internal calibration target may be specifically designed to emulate the reflectance of the external calibration target. For example, the external calibration target may have a first material and the internal calibration target may have a second material. The first and second materials have the reflectance R of the external calibration target. λ, ext and the reflectance R of the internal calibration target λ, int They may be matched to each other so that they are proportional to each other. The internal calibration target may include at least one diffuse reflecting material. The internal calibration target may include: at least one layer of polytetrafluoroethylene (PTFE), at least one optical coating, such as a white surface coating like Nextel® Suede Coating 3101, a dielectric coating, at least one partially reflective dielectric mirror, at least one mirror with a metallic coating including one or more of gold, silver, aluminum, and chromium, and at least one beam splitter.

[0070] An internal calibration target and / or an external calibration target may have at least one diffuse reflective surface. The term “diffusive reflective surface” as used herein is a broad term and should be given in a common and conventional sense to those skilled in the art, and should not be limited to any special or customized meaning. Specifically, the term may refer to a surface configured to scatter incident light at several different angles (e.g., Lambertian reflection in the ideal case), without limitation. An internal calibration target and / or an external calibration target may have diffuse scattering properties and a non-zero reflectivity. Specifically, an internal calibration target and / or an external calibration target may function as a diffuse mirror. An internal calibration target and / or an external calibration target may have a surface roughness configured to produce a Lambertian reflection profile. The surface roughness may be selected such that the specular reflection on the surface has a Lambertian profile based on the ratio of the wavelength of the incident radiation to the surface roughness, thereby forming a “diffusive mirror.” The surface roughness can be selected, for example, depending on the wavelength of the incident light, such that the reflection (e.g., Fresnel reflection produced by a metal, or partial Fresnel and partial diffuse reflection produced by a dielectric material) has a Lambertian profile.

[0071] Further aspects of the present invention disclose a method for calibrating a spectrometer. The terms “calibrating” (also known as “calibration”) as used herein are broad terms and should be given in a common and idiomatic sense to those skilled in the art, and should not be limited to any special or customized sense. Specifically, the term may refer, without limitation, to the process of correcting, adjusting, and / or compensating for a measurement signal in a spectrometer. A calibration process may include determining at least one calibration information item, which may include at least one information item relating to the results of the calibration process, such as a calibration function, calibration coefficient, or calibration matrix, and may be used to convert one or more measurements into one or more calibrated or “true” values. Calibration of a spectrometer may include at least one of wavelength calibration, dark current calibration, or intensity calibration. Calibration may involve at least one two-step process, in which information regarding the relationship between the spectrometer's measurement signal and a known calibration standard, specifically an external calibration target, is determined; and in the second step, this information is used to correct and / or adjust the spectrometer's measurement signal, for example, to reduce, minimize, and / or eliminate the deviation of the measurement signal from the known calibration standard. Thus, calibration may include applying calibration information items to, for example, the spectrometer's measurement signal and / or measurement spectrum. Calibration of a spectrometer can improve and / or maintain the accuracy of measurements performed using the calibrated spectrometer.

[0072] In this method, the spectrometer being calibrated is a spectrometer according to the present invention, for example, a spectrometer according to any one of the embodiments disclosed above and / or any one of the embodiments disclosed in more detail below. Therefore, for possible embodiments and definitions related to the spectrometer, please refer to the description of the spectrometer.

[0073] This method includes the following steps, which may be performed in a given order. However, different orders are also possible. In particular, one, more than one, or all of the method steps may be performed once or repeatedly. Furthermore, the method steps may be performed sequentially, or one or more method steps may be performed in overlapping or parallel order and / or in combination. This method may further include additional method steps not described.

[0074] Book: I. A step of providing an object to the sample interface of a spectrometer, wherein the object includes at least one external calibration target; II. At least one wavelength λ through at least one first optical path i The detector is irradiated with light having and at least one first detector signal S 1,i To obtain, steps; III. At least one wavelength λ through at least one second optical path i The detector is irradiated with light having and at least one calibration signal S 2,i To obtain, steps; IV. First detector signal S 1,i and calibration signal S 2,i By using this, at least one calibration information item c i The steps to decide, Includes.

[0075] Specifically, the calibration information items are:

number

[0076] This method may, in particular, include repeating steps II. to IV. for multiple wavelengths i.

[0077] In a further aspect of the present invention, a method is disclosed for determining at least one spectral piece of information of at least one object by using a spectrometer. In this method, the spectrometer used is a spectrometer according to the present invention, for example, a spectrometer according to any one of the embodiments disclosed above and / or any one of the embodiments disclosed in further detail below. Accordingly, for possible embodiments and definitions relating to the spectrometer, please refer to the description of the spectrometer.

[0078] This method includes the following steps, which may be performed in a given order. However, different orders are also possible. In particular, one, more than one, or all of the method steps may be performed once or repeatedly. Furthermore, the method steps may be performed sequentially, or one or more method steps may be performed in overlapping or parallel order and / or in combination. This method may further include additional method steps not described.

[0079] Book: i. A step of providing an object to a sample interface, wherein the object includes at least one measuring object; ii. Through the first optical path, at least one wavelength λ i The detector is irradiated with light having the following properties, and at least one measurement signal S meas,i To obtain, steps; iii. Through the second optical path, at least one wavelength λ i The detector is irradiated with light having the following properties, and at least one reference signal S ref,i To obtain, steps; iv. Measurement signal S meas,i , reference signal S ref,i and calibration information item c determined by using a method for calibrating a spectrometer apparatus according to the present invention (e.g., any one of the embodiments disclosed above and / or any one of the embodiments disclosed in further detail below). i The steps involve determining the spectral information of an object by using [this method]. Includes.

[0080] The spectral information of an object can specifically be one or more of its reflectance, transmittance, and absorptance. For example, the spectral information of an object may be its reflectance R object,i And here

number

[0081] This method may include repeating steps ii. to iv. for multiple wavelengths i.

[0082] In a further aspect of the present invention, a computer program is disclosed which, when the program is executed by a computer or computer network, includes instructions for the computer or computer network to perform a method for calibrating a spectrometer apparatus according to the present invention (e.g., one of the embodiments disclosed above and / or one of the embodiments disclosed in further detail below), and / or a method for determining at least one spectroscopic piece of information of at least one object according to the present invention (e.g., one of the embodiments disclosed above and / or one of the embodiments disclosed in further detail below).

[0083] In a further aspect of the present invention, a computer-readable storage medium, specifically a non-temporary computer-readable storage medium, is disclosed, which contains instructions to cause a computer or computer network to perform a method for calibrating a spectrometer device according to the present invention (e.g., one of the embodiments disclosed above and / or one of the embodiments disclosed in further detail below) and / or a method for determining at least one spectroscopic piece of information of at least one object according to the present invention (e.g., one of the embodiments disclosed above and / or one of the embodiments disclosed in further detail below), when the instructions are executed by a computer or computer network.

[0084] As used herein, the term “computer-readable storage medium” may specifically refer to non-temporary data storage means such as hardware storage media on which computer executable instructions are stored. Specifically, the storage medium may be, or may include, random access memory (RAM) and / or read-only memory (ROM).

[0085] The spectrometer apparatus and method according to the present invention offer numerous advantages over similar known apparatuses and methods in one or more of the embodiments described above and / or in one or more of the embodiments described in more detail below. Specifically, a spectrometer apparatus in which the transmission profiles of the first and second optical paths are proportional to each other may provide an internal calibration path specifically designed such that the temperature-induced drift of the second optical path is identical to the temperature-induced drift of the first optical path having an object applied to the spectrometer apparatus. Thus, the spectrometer apparatus can provide reduced temperature dependence.

[0086] The spectrometer apparatus and method according to the present invention can specifically provide an optical design for the internal calibration path of a spectrometer apparatus (e.g., a spectrometer apparatus having an angle-dependent dispersion element) that exhibits a spectrum dependence of, for example, the x-axis and / or y-axis, with respect to the direction from which the light is collected (e.g., the direction from the angle of incidence). As an example, the dispersion element may be a set of optical filters, specifically interference filters, such as narrow-band-pass filters. The spectrometer apparatus and method according to the present invention can specifically be applied to a spectrometer apparatus that uses an open-port optical and / or reference emitter for calibration of the spectrometer apparatus.

[0087] The spectrometer apparatus according to the present invention may specifically include matching the transmission profiles of the optical filters for the first optical path and the second optical path, where T 1,NBP =d·T 2,NBPHere, d is a constant independent of temperature, wavelength, and / or angle. The transmission profile of the optical filter may depend on the angular distribution of the light irradiated onto the optical filter. Therefore, in order to match the transmission profiles in the first and second optical paths, the spectrometer according to the present invention can provide matched angular distributions of light in the first and second optical paths on the optical filter. The matched transmission profiles of the optical filter for both optical paths can provide improved temperature compensation for the light source. Furthermore, if the reflectance of the internal calibration target matches the reflectance of the external calibration target, then R is available at all wavelengths in the wavelength region of interest. λ,ext =a*R λ,int Therefore, temperature compensation for the light source is further improved, specifically, the calibration information items become constant across all temperatures.

[0088] The spectrometer apparatus according to the present invention can, in particular, provide the same effective transmission profile for light in the first and second optical paths. The transmission profile of the optical filter may depend on the distribution of incident light to the optical filter. In one embodiment, the internal calibration target may be positioned in a specific manner to match the transmission profile, which can provide an improved open-port calibration scheme, in particular for the spectrometer apparatus. In one embodiment, the spectrometer apparatus may include a reference light source positioned symmetrically with respect to the light source with respect to the optical filter, which can provide an improved calibration scheme, in particular for using a second reference light source. The constant d is specifically the calibration information item c i This may result in scaling, but without the undesirable temperature dependence.

[0089] The terms “have,” “equip,” and “include,” as used herein, or any grammatical variations thereof, are used in a non-exclusive manner. Thus, these terms can refer to both situations in which the entity described in this context has no further features in addition to the features introduced by these terms, and situations in which one or more further features exist. For example, the expressions “A has B,” “A equips B,” and “A includes B” can refer to both situations in which A has no other elements other than B (i.e., A is composed solely of B), and situations in which entity A has one or more further elements other than B, such as elements C, C and D, or further elements.

[0090] Furthermore, it should be noted that the terms “at least one,” “one or more,” or similar expressions indicating that a feature or element may exist more than once, are typically used only once when introducing each feature or element. In most cases, when referring to each feature or element, the expressions “at least one” or “one or more” are not repeated, regardless of the fact that each feature or element may exist once or more times.

[0091] Furthermore, the terms “preferably,” “more preferably,” “specifically,” “more specifically,” “particularly,” “even more specifically,” or similar terms used herein are used in combination with any feature without limiting the possibility of alternatives. Thus, any feature introduced by these terms is any feature and is not intended to limit the scope of the claims in any sense. The present invention may also be carried out by using alternative features, as will be recognized by those skilled in the art. Similarly, any feature introduced by “in one embodiment of the present invention” or similar expression is intended to be any feature, without limiting alternative embodiments of the present invention, without limiting the scope of the present invention, and without limiting the possibility of combining such introduced features with any or non-any other features of the present invention.

[0092] In summary, without prejudice to further possible embodiments, the following embodiments may be conceivable: Embodiment 1: A spectrometer device for acquiring spectral information relating to at least one object, wherein the spectrometer device is — with at least one detector for detecting light from an object; —At least one optical filter configured to transfer incident light within at least one selected wavelength range to the detector, wherein the transmission profile of the optical filter is dependent on the angle of incidence; — with at least one light source configured to emit illumination light within at least one optical spectral range; —At least one sample interface configured to allow the illumination light to illuminate the object and to allow light from the object to propagate through the light filter to the detector; — At least one first optical path, the first optical path is configured to allow the illumination light to propagate to the detector via the optical filter by passing through the sample interface at least once, and the optical filter has a first transmission profile T for the first optical path 1,NBP Having at least one first optical path; — At least one internal calibration target and at least one second optical path, the second optical path configured to allow the illumination light to propagate to the detector via the optical filter by interacting with the internal calibration target at least once, the optical filter having a second transmission profile T for the second optical path 2,NBP Having at least one internal calibration target and at least one second optical path; Equipped with, The transmission profiles of the optical filters in the first and second optical paths are relative to each other. 1,NBP (λ) = d·T 2,NBP A spectrometer in which (λ) is proportional and d is independent of one or more of the temperature, wavelength, or angle of incidence.

[0093] Embodiment 2: A spectrometer according to the preceding embodiment, wherein the spectrometer is a near-infrared spectrometer.

[0094] Embodiment 3: A spectrometer according to any one of the preceding embodiments, wherein the irradiated light has an optical spectral range that is at least partially located in the near-infrared spectral range.

[0095] Embodiment 4: The transmission profile of the first optical path is

number

number

[0096] Embodiment 5: A spectrometer apparatus according to any one of the preceding embodiments, wherein the internal calibration target includes at least one pattern, the pattern being arranged such that it partially covers the sample interface.

[0097] Embodiment 6: A spectrometer apparatus according to a prior embodiment, wherein the pattern is at least one pattern selected from the group consisting of a dot pattern, a checkerboard pattern, or a random pattern.

[0098] Embodiment 7: A spectrometer according to one of the two preceding embodiments, wherein the pattern covers 0.1 to 50% of the surface of the sample interface, more specifically 0.5 to 25% of the surface of the sample interface, and more specifically 1 to 10% of the surface of the sample interface.

[0099] Embodiment 8: A spectrometer apparatus according to any one of the prior embodiments, wherein the internal calibration target is translucent and is positioned such that the internal calibration target at least partially covers the sample interface.

[0100] Embodiment 9: A spectrometer apparatus according to any one of the preceding embodiments, wherein the optical filter, the light source, the sample interface, and the internal calibration target are arranged such that the angular distribution of the first optical path on the surface of the optical filter is the mirror image angular distribution of the second optical path, or vice versa.

[0101] Embodiment 10: A spectrometer apparatus according to any one of the preceding embodiments, wherein the optical filter, the light source, the sample interface, and the internal calibration target are arranged such that the angular distribution of the first optical path on the surface of the optical filter is the diagonal mirror-image angular distribution of the second optical path, or vice versa.

[0102] Embodiment 11: A spectrometer apparatus according to any one of the preceding embodiments, wherein the optical filter, the light source, the sample interface, and the internal calibration target are arranged such that the transmission profiles of the first optical path and the second optical path are identical.

[0103] Embodiment 12: A spectrometer according to any one of the preceding embodiments, wherein the internal calibration target is non-transmissive, and the spectrometer comprises an additional reference light source configured to illuminate the internal calibration target, wherein the light source and the reference light source are arranged such that the angle of incidence of light from the first optical path and the angle of incidence of light from the second optical path are symmetrical on the optical filter.

[0104] Embodiment 13: The spectrometer device according to any one of the preceding embodiments, comprising at least one evaluation unit for evaluating at least one detector signal generated by the detector and determining the spectroscopic information of the object using the detector signal.

[0105] Embodiment 14: The spectrometer device irradiates the detector with light having at least one wavelength λ via the at least one first optical path to obtain at least one first detector signal S, the object includes at least one external calibration target, the spectrometer device irradiates the detector with light having at least one wavelength λ via the at least one second optical path to obtain at least one calibration signal S, and the evaluation unit is configured to determine at least one calibration information item c by using the first detector signal S and the calibration signal S. The spectrometer device according to the preceding embodiment. i 1,i i 2,i 1,i 2,i i

[0106] Embodiment 15: The spectrometer device further irradiates the detector with light having at least one wavelength λ via the at least one first optical path to obtain at least one measurement signal S, the object includes at least one measurement object, the spectrometer device further irradiates the detector with light having at least one wavelength λ via the at least one second optical path to obtain at least one reference signal S, and the evaluation unit is configured to determine the spectroscopic information about the object by using the calibration information item c, the reference signal S, and the first detector signal. The spectrometer device according to the preceding embodiment. i meas,i i ref,i i ref,i

[0107] ​​​​​​​​​​​​​ Embodiment 16: The spectroscopic information of the object is the reflectance R object,i and

Number

[0108] Embodiment 17: The object includes at least one external calibration target, and the reflectance R of the external calibration target λ, ext and the reflectance R of the internal calibration target λ, int are in a proportional relationship with each other,

Number

[0109] Embodiment 18: The reflectance R of the external calibration target λ, ext and the reflectance R of the internal calibration target λ, int are in a proportional relationship with each other at each wavelength within the selected wavelength range, is a spectrometer device according to the preceding embodiment.

[0110] Embodiment 19: The constant a does not depend on temperature and / or wavelength, is a spectrometer device according to any one of the two preceding embodiments.

[0111] Embodiment 20: The external calibration target includes a standardized diffuse reflection target having a reflectance of more than 99% (>99%) in the range of 400 nm to 1500 nm and a reflectance of more than 95% (>95%) in the range of 250 nm to 2500 nm, is a spectrometer device according to any one of the three preceding embodiments.

[0112] Embodiment 21: The internal calibration target is designed to emulate the reflectance of the external calibration target, is a spectrometer device according to any one of the four preceding embodiments.

[0113] Embodiment 22: The external calibration target has a first material, and the internal calibration target has a second material, wherein the first material and the second material have a reflectance R of the external calibration target. λ, ext and the reflectance R of the internal calibration target λ, int A spectrometer apparatus according to one of the five preceding embodiments, wherein the elements are matched to each other so as to be proportional to each other.

[0114] Embodiment 23: A spectrometer apparatus according to any one of the six preceding embodiments, wherein the internal calibration target comprises at least one diffuse reflectance material, and the internal calibration target comprises at least one layer of polytetrafluoroethylene (PTFE), at least one optical coating (e.g., a white surface coating), a dielectric coating, at least one partially reflective dielectric mirror, at least one mirror with a metallic coating including one or more of gold, silver, aluminum, and chromium, and at least one beam splitter.

[0115] Embodiment 24: A method for calibrating a spectrometer, wherein the spectrometer is a spectrometer according to any one of the preceding embodiments, and the method is: I. A step of providing an object to the sample interface of the spectrometer, wherein the object includes at least one external calibration target; II. At least one wavelength λ through at least one first optical path i The detector is irradiated with light having and at least one first detector signal S 1,i To obtain, steps; III. The at least one wavelength λ through at least one second optical path i The detector is irradiated with light having and at least one calibration signal S 2,i To obtain, steps; IV. The first detector signal S 1,i and the calibration signal S 2,iBy using this, at least one calibration information item c i The steps to determine, Methods that include...

[0116] Embodiment 25: The method according to a prior embodiment, comprising repeating steps II. to IV. for a plurality of wavelengths i.

[0117] Embodiment 26: A method for determining at least one spectral piece of information of at least one object by using a spectrometer according to any one of the prior embodiments relating to a spectrometer, wherein the method is: i. A step of providing an object to a sample interface, wherein the object includes at least one measuring object; ii. Through the first optical path, at least one wavelength λ i The detector is irradiated with light having the following properties, and at least one measurement signal S meas,i To obtain, steps; iii. Through the second optical path, at least one wavelength λ i The detector is irradiated with light having the following properties: at least one reference signal S ref,i To obtain, steps; iv. The measurement signal S meas,i , the aforementioned reference signal S ref,i , and calibration information item c determined by using the method for calibrating a spectrometer device according to any one of the preceding embodiments. i The steps include determining the spectral information of the object by using the following: Methods that include...

[0118] Embodiment 27: A method according to a prior embodiment, wherein the spectral information of the object includes one or more of the reflectance, transmittance, and absorptance of the object.

[0119] Embodiment 28: The method according to one of the two preceding embodiments, comprising repeating steps ii. to iv. for a plurality of wavelengths i.

[0120] Embodiment 29: A computer program, which, when executed by a computer or computer network, specifically by a spectrometer according to any one of the prior embodiments relating to a spectrometer, more specifically by an evaluation unit of a spectrometer according to Embodiment 13, includes instructions causing the computer or computer network, specifically the spectrometer, to perform a method for calibrating a spectrometer according to any one of the prior embodiments relating to a method for calibrating a spectrometer, and / or a method for determining at least one spectral piece of information of at least one object according to any one of the prior embodiments relating to a method for determining at least one spectral piece of information of at least one object.

[0121] Embodiment 30: A computer-readable storage medium containing instructions, specifically a non-temporary computer-readable storage medium containing instructions, wherein when the instructions are executed by a computer or computer network, specifically by a spectrometer according to any one of the prior embodiments relating to a spectrometer, more specifically by an evaluation unit of a spectrometer according to Embodiment 13, the instructions cause the computer or computer network to execute a method for calibrating a spectrometer according to any one of the prior embodiments relating to a method for calibrating a spectrometer, and / or a method for determining at least one spectral piece of information of at least one object according to any one of the prior embodiments relating to a method for determining at least one spectral piece of information of at least one object. [Brief explanation of the drawing]

[0122] Further optional features and embodiments are disclosed in more detail in the description following the embodiments, preferably in conjunction with dependent claims, where each optional feature may be implemented in independent forms as well as in any feasible combination, as will be understood by those skilled in the art. The scope of the present invention is not limited by preferred embodiments. Embodiments are schematically shown in the figures, where the same reference numerals in these figures refer to the same or functionally equivalent elements.

[0123] In the diagram: [Figure 1] This figure schematically illustrates different embodiments of a spectrometer device for acquiring spectral information about at least one object. [Figure 2] This figure schematically illustrates different embodiments of a spectrometer device for acquiring spectral information about at least one object. [Figure 3] This figure schematically illustrates different embodiments of a spectrometer device for acquiring spectral information about at least one object. [Figure 4] This figure schematically illustrates different embodiments of a spectrometer device for acquiring spectral information about at least one object. [Figure 5] This figure schematically illustrates different embodiments of a spectrometer device for acquiring spectral information about at least one object. [Figure 6] This figure schematically illustrates different embodiments of a spectrometer device for acquiring spectral information about at least one object. [Figure 7] This diagram shows a flowchart illustrating an embodiment of a method for calibrating a spectrometer. [Figure 8] This figure shows a flowchart of an embodiment of a method for determining at least one spectral piece of information of at least one object. [Modes for carrying out the invention]

[0124] Detailed description of the embodiment Figure 1 schematically shows a first embodiment of a spectrometer device 110 for acquiring spectral information about at least one object 112. The spectrometer device 110 may specifically be a near-infrared spectrometer 114.

[0125] The spectrometer 110 comprises at least one detector 116 for detecting detection light 118 from an object 112. The detector 116 may comprise a single optically sensitive element or area, or multiple optically sensitive elements or areas (not shown). Specifically, the detector 116 may comprise at least one detector array, more specifically an array of photosensitive elements, or comprise such arrays. Each photosensitive element may comprise at least one photosensitive area adapted to generate an electrical signal in response to the intensity of incident light, which may in particular be provided to an evaluation unit 119. Specifically, the spectrometer 110 may comprise at least one evaluation unit 119 for evaluating at least one detector signal generated by the detector 116 and for determining spectral information about the object 112 using the detector signal.

[0126] The spectrometer device 110 further includes at least one optical filter 120 configured to transfer incident light within at least one selected wavelength range to the detector 116. The transmission profile of the optical filter 120 depends on the angle of incidence. As shown in Figure 1, the optical filter 120 can be positioned adjacent to the detector 116, for example by placing the optical filter 120 on top of the detector 116. The optical filter 120 may include, as an example, at least one narrowband-pass filter 122, more specifically a set of narrowband-pass filters 122. The narrowband-pass filter 122 is configured to transmit only light within a narrowly selected wavelength range, such as, for example, 10 to 100 nm, specifically 10 to 50 nm, more specifically a wavelength range with a width of 20 nm, most specifically a wavelength range with a width of 15 nm. For example, in a set of narrowband-pass filters 122, each narrowband-pass filter 122 may have a narrowband-selective wavelength range that is at least partially different from one another.

[0127] The spectrometer 110 further includes at least one light source 124 configured to emit illumination light 126 in at least one optical spectral range. For example, the light source 124 may include at least one light-emitting diode (LED) 128. In the example of Figure 1, the illumination light 126 has an optical spectral range that is at least partially located in the near-infrared spectral range. The spectrometer 110 also includes at least one sample interface 130 configured to allow the illumination light 126 to illuminate an object 112 and to allow light from the object 112 to propagate to the detector 116 via an optical filter 120.

[0128] The spectrometer device 110 further comprises at least one first optical path 132. The first optical path 132 is configured such that the irradiation light 126 passes through the sample interface 130 at least once and propagates to the detector 116 via the optical filter 120. The optical filter 120 has a first transmission profile T for the first optical path 132. 1,NBPThe spectrometer device 110 also includes at least one internal calibration target 134 and at least one second optical path 136. The second optical path 136 is configured to allow the illumination light 126 to propagate to the detector 116 via the optical filter 120 by interacting with the internal calibration target 134 at least once. The optical filter 120 has a second transmission profile T for the second optical path 136. 2,NBP The transmission profiles of the optical filters 120 of the first optical path 132 and the second optical path 136 are proportional to each other, and T 1,NBP (λ) = d·T 2,NBP (λ) is such that d does not depend on one or more of the temperature, wavelength, or angle of incidence.

[0129] The transmission profile of the first optical path 132 is:

number

[0130] The transmission profile of the second optical path 136 is:

number

[0131] Here, θ can be the angle of incidence of light relative to the surface normal of the optical filter 120, and T(θ,λ,λ i ) can be the transmission profile of the optical filter 120 at a predetermined incident angle θ, ρ i (θ) can be the angular distribution on the surface of the optical filter 120 in the first optical path 132 i=1 and the second optical path 136 i=2, respectively.

[0132] As shown in Figure 1, the internal calibration target 134 may include at least one pattern 138. The pattern 138 may be positioned to partially cover the sample interface 130. Specifically, the pattern 138 may be positioned to partially reflect the illumination light 126 emitted by the light source 124, allowing the reflected light to propagate through the optical filter 120 to the detector 116 in the second optical path 136. The pattern 138 may be at least one pattern selected from the group consisting of dot patterns, checkerboard patterns, or random patterns. The pattern 138 may cover 0.1 to 50% of the surface of the sample interface 130, more specifically 0.5 to 25%, and more specifically 1 to 10% of the surface of the sample interface 130. The internal calibration target 134, including pattern 138, can specifically generate angular distributions such that the angular distribution of the optical filter 120 in the first optical path 132 and the angular distribution of the optical filter 120 in the second optical path 136 are proportional to each other (for example, ρ1(θ) = e * ρ2(θ), where e is a dimensionless constant).

[0133] Figure 2 schematically shows another exemplary embodiment of the spectrometer 110. The embodiment of the spectrometer 110 in Figure 2 can broadly correspond to the embodiment of the spectrometer 110 shown in Figure 1. Therefore, please refer to the description of Figure 1 for a description of the spectrometer 110.

[0134] In the embodiment shown in Figure 2, the internal calibration target 134 may be semi-transparent. Specifically, the internal calibration target 134 may be semi-transparent in at least a selected wavelength range. The internal calibration target 134 may be positioned such that it at least partially covers the sample interface 130. The semi-transparent internal calibration target 134 can specifically produce an angular distribution such that the angular distribution of the optical filter 120 in the first optical path 132 and the angular distribution of the optical filter 120 in the second optical path 136 are proportional to each other (for example, ρ1(θ) = e * ρ2(θ), where e is a dimensionless constant).

[0135] Figure 3 schematically shows another exemplary embodiment of the spectrometer 110. The embodiment of the spectrometer 110 in Figure 3 can broadly correspond to the embodiment of the spectrometer 110 shown in Figure 1. Therefore, please refer to the description of Figure 1 for a description of the spectrometer 110. Figure 3 shows a schematic top view of the spectrometer 110.

[0136] In the embodiment shown in Figure 3, the optical filter 120, light source 124, sample interface 130, and internal calibration target 134 may be arranged such that the angular distribution of the first optical path 132 on the surface of the optical filter 120 is the mirror image angular distribution of the second optical path 136, or vice versa.

[0137] Figure 4 schematically shows another exemplary embodiment of the spectrometer 110. The embodiment of the spectrometer 110 in Figure 4 can broadly correspond to the embodiment of the spectrometer 110 shown in Figure 1. Therefore, please refer to the description of Figure 1 for a description of the spectrometer 110. Figure 4 shows a schematic top view of the spectrometer 110.

[0138] In the embodiment shown in Figure 4, the optical filter 120, light source 124, sample interface 130, and internal calibration target 134 may be arranged such that the angular distribution of the first optical path 132 on the surface of the optical filter 120 is the diagonal mirror-image angular distribution of the second optical path 136, or vice versa. In the exemplary embodiments shown in Figures 3 and 4, the angular distributions of the first optical path 132 and the second optical path 136 may be non-proportional to each other. However, the transmission profiles of the optical filter 120 for the first optical path 132 and the second optical path 136 are still proportional to each other.

[0139] Figure 5 schematically shows another exemplary embodiment of the spectrometer 110. The embodiment of the spectrometer 110 in Figure 5 can broadly correspond to the embodiment of the spectrometer 110 shown in Figure 1. Therefore, please refer to the description of Figure 1 for a description of the spectrometer 110. Figure 5 shows a schematic top view of the spectrometer 110.

[0140] As shown in Figure 5, the optical filter 120, light source 124, sample interface 130, and internal calibration target may not be symmetrically arranged, and therefore the angular distributions of the first optical path 132 and the second optical path 136 may not be identical. However, the optical filter 120, light source 124, sample interface 130, and internal calibration target 134 may be arranged so that the transmission profiles of the first optical path 132 and the second optical path 136 are identical. Specifically, the optical filter 120, light source 124, sample interface 130, and internal calibration target 134 may be arranged such that,

number

[0141] Figure 6 schematically shows another exemplary embodiment of the spectrometer 110. The embodiment of the spectrometer 110 in Figure 6 can broadly correspond to the embodiment of the spectrometer 110 shown in Figure 1. Therefore, please refer to the description of Figure 1 for a description of the spectrometer 110.

[0142] In the embodiment of Figure 6, the internal calibration target 134 may be opaque. Specifically, the internal calibration target 134 may be at least opaque in a selected wavelength range. The spectrometer 110 may include an additional reference light source 140 configured to illuminate the internal calibration target 134. Specifically, the reference light source 140 may be embodied similarly to the light source 124. The light source 124 and the reference light source 140 may be arranged on the optical filter 120 such that the angle of incidence of light from the first optical path 132 and the angle of incidence of light from the second optical path 136 are symmetrical. Thus, although light may be collected from different directions, the angular distribution of the optical filter 120 in the first optical path 132 and the angular distribution of the optical filter 120 in the second optical path 136 are proportional to each other, for example, ρ1(θ) = e * ρ2(θ), where e is a dimensionless constant.

[0143] Figure 7 shows a flowchart of an exemplary embodiment of a method for calibrating the spectrometer 110. In this method, the spectrometer 110 to be calibrated is the spectrometer 110 according to the present invention, which is, for example, one of the embodiments disclosed above with respect to Figures 1 to 6 and / or any other embodiment disclosed herein. Therefore, for a description of the spectrometer 110, please refer to the description of Figures 1 to 6.

[0144] This method includes the following steps, which can be performed in a given order. However, different orders are also possible. In particular, one, more, or all method steps can be performed once or repeatedly. Furthermore, the method steps can be performed sequentially, or one or more method steps can be performed in overlapping or parallel manner, and / or in combination. This method may also include additional method steps not described.

[0145] Book: I. A step of providing object 112 (referred to as reference no. 142) to the sample interface 130 of a spectrometer 110, wherein object 112 includes at least one external calibration target; II. At least one wavelength λ through at least one first optical path 132 (shown in reference number 144) i The detector 116 is irradiated with light having the following properties, and at least one first detector signal S 1,i To obtain, steps; III. At least one wavelength λ through at least one second optical path 136 (shown in reference number 146) i The detector 116 is irradiated with light having the following properties, and at least one calibration signal S 2,i To obtain, steps; IV. The first detector signal S (shown in reference number 148) 1,i and the calibration signal S 2,i By using this, at least one calibration information item c i The steps to determine, Includes.

[0146] Specifically, the calibration information items are:

number

[0147] This method may, in particular, include repeating steps II. to IV. for multiple wavelengths i.

[0148] Figure 8 shows a flowchart of an embodiment of a method for determining at least one spectral piece of information of at least one object 112. This method involves using a spectrometer 110, the spectrometer 110 used being, for example, one of the embodiments disclosed above with respect to Figures 1 to 6, and / or any of the other embodiments disclosed herein. Therefore, for a description of the spectrometer 110, please refer to the description of Figures 1 to 6.

[0149] This method includes the following steps, which may be performed in a predetermined order. However, different orders are also possible. In particular, one, more than one, or all of the method steps may be performed once or repeatedly. Furthermore, the method steps may be performed sequentially, or one or more method steps may be performed in overlapping or parallel order and / or in combination. This method may further include additional method steps not described.

[0150] Book: i. A step of providing object 112 (indicated by reference number 150) to a sample interface 130, wherein object 112 includes at least one measuring object; ii. Through the first optical path 132 (indicated by reference number 152), at least one wavelength λ i The detector 116 is irradiated with light having the following properties, and at least one measurement signal S meas,i To obtain, steps; iii. Through the second optical path 136 (indicated by reference number 154), at least one wavelength λ i The detector 116 is irradiated with light having the following properties, and at least one reference signal S ref,i To obtain, steps; iv. The measurement signal S (indicated by reference number 156) meas,i , the aforementioned reference signal S ref,i and calibration information item c determined by using a method for calibrating the spectrometer apparatus 110 according to the present invention, such as the exemplary embodiment shown in Figure 7 and / or other embodiments disclosed herein. i The steps include determining the spectral information of object 112 by using, Includes.

[0151] The spectral information of object 112 may specifically be one or more of the reflectance, transmittance, and absorptance of object 112. For example, the spectral information of object 112 may be the reflectance R object,i And here

number

[0152] This method may include repeating steps ii. to iv. for multiple wavelengths i. [Explanation of Symbols]

[0153] List of reference numbers 110 Spectrometer equipment 112 Object 114 Near-infrared spectrometer 116 detectors 118 Detection light 119 evaluation units 120 Light Filters 122 Narrowband Pass Filter 124 Light source 126 Irradiation light 128 Light-Emitting Diodes 130 Sample Interface 132 1st optical path 134 Internal Calibration Targets 136 Second optical path 138 patterns 140 Reference light source 142 Providing an object to the sample interface 144 Irradiating the detector through the first optical path 146 Irradiate the detector through the second optical path. 148 Calibration Information Item c i To decide 150. Providing objects to the sample interface. 152 Irradiating the detector through the first optical path 154 Irradiating the detector through the second optical path 156 Determining the spectral information of an object

Claims

1. A spectrometer device (110) for acquiring spectral information relating to at least one object (112), wherein the spectrometer device (110) — with at least one detector (116) for detecting detected light (118) from the object (112); —At least one optical filter (120) configured to transfer incident light within at least one selected wavelength range to the detector (116), wherein the transmission profile of the optical filter (120) depends on the angle of incidence; — comprising at least one light source (124) configured to emit illumination light (126) within at least one optical spectral range; —At least one sample interface (130) configured to allow the irradiation light (126) to irradiate the object (112) and to allow light from the object (112) to propagate to the detector (116) via the light filter (120); - At least one first optical path (132) is configured to allow the irradiation light (126) to propagate to the detector (116) via the optical filter (120) by passing through the sample interface (130) at least once, and the optical filter (120) has a first transmission profile T for the first optical path (132) 1,ＮＢＰ Having at least one first optical path (132); - At least one internal calibration target (134) and at least one second optical path (136), the second optical path (136) is configured to allow the illumination light (126) to propagate to the detector (116) via the optical filter (120) by interacting with the internal calibration target (134) at least once, and the optical filter (120) has a second transmission profile T for the second optical path (136) 2,ＮＢＰ Having at least one internal calibration target (134) and at least one second optical path (136); Equipped with, The transmission profiles of the optical filters (120) of the first optical path (132) and the second optical path (136) are relative to each other. 1,ＮＢＰ (λ) = d・T 2,ＮＢＰ A spectrometer (110) wherein the optical filter (120), the light source (124), the sample interface (130), and the internal calibration target (134) are arranged such that the transmission profiles of the first optical path (132) and the second optical path (136) are identical, with d being proportional to (λ) and independent of one or more of the temperature, wavelength, or angle of incidence.

2. The spectrometer apparatus (110) according to claim 1, wherein the internal calibration target (134) includes at least one pattern (138), the pattern (138) is arranged such that the pattern (138) partially covers the sample interface (130).

3. The spectrometer apparatus (110) according to claim 2, wherein the pattern (138) is at least one pattern selected from the group consisting of a dot pattern, a checkerboard pattern, or a random pattern.

4. The spectrometer apparatus (110) according to claim 1 or 2, wherein the internal calibration target (134) is translucent and is positioned such that the internal calibration target (134) at least partially covers the sample interface (130).

5. The spectrometer apparatus (110) according to claim 1 or 2, wherein the optical filter (120), the light source (124), the sample interface (130), and the internal calibration target (134) are arranged such that the angular distribution of the first optical path (132) on the surface of the optical filter (120) is the mirror image angular distribution of the second optical path (136), or vice versa.

6. The spectrometer apparatus (110) according to claim 1 or 2, wherein the optical filter (120), the light source (124), the sample interface (130), and the internal calibration target (134) are arranged such that the angular distribution of the first optical path (132) on the surface of the optical filter (120) is the diagonal mirror image angular distribution of the second optical path (136), or vice versa.

7. The spectrometer apparatus (110) according to claim 1 or 2, wherein the internal calibration target (134) is non-transmissive, and the spectrometer apparatus (110) comprises an additional reference light source (140) configured to illuminate the internal calibration target (134), and the light source (124) and the reference light source (140) are arranged such that the angle of incidence of light from the first optical path (132) and the angle of incidence of light from the second optical path (136) are symmetrical on the optical filter (120).

8. The spectrometer (110) according to claim 1 or 2, further comprising at least one evaluation unit (119) for evaluating at least one detector signal generated by the detector (116) and for determining the spectral information of the object (112) using the detector signal.

9. The spectrometer device (110) irradiates the detector (116) with light having at least one wavelength λ via the at least one first optical path (132) and is configured to obtain at least one first detector signal S ｉ The object (112) includes at least one external calibration target. The spectrometer device (110) irradiates the detector (116) with light having at least one wavelength λ via the at least one second optical path (136) and is configured to obtain at least one calibration signal S 1,ｉ The evaluation unit (119) is configured to determine at least one calibration information item c by using the first detector signal S ｉ and the calibration signal S 2,ｉ The spectrometer device (110) according to claim 8, wherein 1,ｉ and the calibration signal S 2,ｉ and is configured to determine at least one calibration information item c ｉ by using the first detector signal S and the calibration signal S

10. The spectrometer device (110) further transmits at least one wavelength λ through the at least one first optical path (132) ｉ The detector (116) is irradiated with light having the property, and at least one measurement signal S ｍｅａｓ,ｉ The spectrometer (110) is configured to obtain, wherein the object (112) includes at least one measuring object, and the spectrometer (110) further obtains at least one wavelength λ through the at least one second optical path (136) ｉ The detector (116) is irradiated with light having the following properties, and at least one reference signal S ｒｅｆ,ｉ The evaluation unit (119) is configured to obtain calibration information item c ｉ , reference signal S ｒｅｆ,ｉ The spectrometer device (110) according to claim 9, configured to determine the spectral information relating to the object (112) using the first detector signal.

11. A method for calibrating a spectrometer (110), wherein the spectrometer (110) is the spectrometer (110) described in claim 1 or 2, and the method is: I. A step of providing an object (112) to the sample interface (130) of the spectrometer (110), wherein the object (112) includes at least one external calibration target; II. At least one wavelength λ through at least one first optical path (132) ｉ The detector (116) is irradiated with light having the following properties, and at least one first detector signal S 1,ｉ To obtain, steps; III. At least one wavelength λ through at least one second optical path (136) ｉ The detector (116) is irradiated with light having the following properties, and at least one calibration signal S 2,ｉ To obtain, steps; IV. The first detector signal S 1,ｉ and the positive Calc signal S 2,ｉ By using this, at least one calibration information item c ｉ The steps to determine, Methods that include...

12. A method for determining at least one spectral piece of information of at least one object (112) by using a spectrometer (110) according to claim 1 or 2 relating to a spectrometer (110), wherein the method is: i. A step of providing an object (112) to a sample interface (130), wherein the object (112) includes at least one object to be measured; ii. Through the first optical path (132), at least one wavelength λ ｉ The detector (116) is irradiated with light having the following properties, and at least one measurement signal S ｍｅａｓ,ｉ To obtain, steps; iii. Through the second optical path (136), at least one wavelength λ ｉ The detector (116) is irradiated with light having the following properties, and at least one reference signal S ｒｅｆ,ｉ To obtain, steps; iv. The measurement signal S ｍｅａｓ,ｉ , the aforementioned reference signal S ｒｅｆ,ｉ and calibration information item c determined by using the method for calibrating the spectrometer apparatus (110) described in claim 11. ｉ The steps include determining the spectral information of the object (112) by using the following: Methods that include...

13. A computer program, which, when executed by a computer or computer network, includes instructions to cause the computer or computer network to perform a method for calibrating a spectrometer device (110) as described in claim 11, and / or a method for determining at least one spectral piece of information of at least one object (112) as described in claim 12.

14. A computer-readable storage medium containing instructions, wherein when the instructions are executed by a computer or computer network, the instructions cause the computer or computer network to execute a method for calibrating a spectrometer device (110) according to claim 11, and / or a method for determining at least one spectral piece of information of at least one object (112) according to claim 12.

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