Spectrometer device for acquiring spectral information about at least one object

Abstract

A spectrometer device (110) for acquiring spectral information relating to at least one object (112) is disclosed. The spectrometer device (110) is: — with at least one detector (116) for detecting light from an object (112); — comprising at least one optical filter (122) configured to transfer incident light within at least one selected wavelength range to the detector (116); — with at least one light source (126) configured to emit light in at least one optical spectral range; —At least one sample interface (132) configured to allow light emitted from the light source (126) to illuminate an object (112) held by the sample interface (132), and to allow light from the object (112) held by the sample interface (132) to propagate to the detector (116) via the light filter (122), wherein the sample interface (132) comprises at least one module cover window (134) including at least one substrate (136), and the module cover window (134) comprises at least one internal calibration target (138) that partially covers the substrate (136); —At least one first optical path (140), the first optical path (140) is configured to allow light emitted from the light source (126) to propagate to the detector (116) via the optical filter (122) by passing through the sample interface (132) at least once; —At least one second optical path (142), the second optical path (142) is configured to allow light emitted from the light source (126) to propagate to the detector (116) via the optical filter (122) by interacting with the internal calibration target (138) at least once, It is equipped with.

Description

Technical Field

[0001] The present invention relates to a spectrometer apparatus and several applications. Such an apparatus can generally be used for investigation or monitoring purposes, particularly in the infrared (IR) spectral region, specifically in the near-infrared (NIR) spectral region, and in the visible (VIS) spectral region. However, further applications are possible.

Background Art

[0002] Generally, a spectrometer is known to collect information regarding the spectral light composition from an object when irradiating, reflecting, and / or absorbing light. In order to be able to compare spectra from multiple spectrometers, it is necessary to calibrate the spectrometers. 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, the y-axis calibration of the recorded spectrum in a spectrum in reflectance measurements, which is generally required in the field of diffuse reflectance near-infrared spectroscopy, may use an external reflection standard placed at the object position. Alternatively, the calibration may use an internal calibration target that is automatically moved into the measurement field by the spectrometer itself in order to calibrate the response of the spectrometer.

[0003] However, in the field of mobile spectroscopy, it may be impossible to use an external calibration standard and / or a movable internal calibration target. For this reason, calibration schemes that do not require placing an external calibration standard at the object position and / or a movable internal calibration target are known. These calibration schemes may use an internal calibration path.

[0004] US2021 / 0063241A1 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 the light from the measurement target; an optical duct 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.

[0005] US2021 / 0356322A1 describes a method for calibrating an optical sensor, the method including obtaining a first characteristic of an external light source via a detector of the optical sensor with an internal light source of the optical sensor turned off; driving the internal light source; obtaining a second characteristic of the internal light source and the external light source via the detector based on driving of the internal light source; and obtaining a reference characteristic of the internal light source based on the first characteristic and the second characteristic for calculating an absorbance of an object.

[0006] Despite the advantages achieved by known methods and devices, some technical problems remain. Generally, the calibration of a spectrometer aims at a constant c i =S 1,i / S 2,i =const, where c i is 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 radiant flux of a temperature-dependent light source Φ Light . Further, the signals can depend on 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 the external path and the transmittance T 1,filter of an optical filter in the internal path:

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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. This different weighting is 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 a change in the ratio of light across the temperature of the internal and external paths. As a result, the 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.

[0008] Furthermore, while compact spectrometers require a small footprint and a compact design, high-performance spectrometers require blocking stray light to achieve a high dynamic range. To prevent light from leaking out of the module from the designated optical path, the material must be opaque. [Prior art documents] [Patent Documents]

[0009] [Patent Document 1] US2021 / 0063241A1 [Patent Document 2] US2021 / 0356322A1 [Overview of the project] [Problems that the invention aims to solve]

[0010] Therefore, it is desirable to provide a spectrometer that at least partially solves the above-mentioned technical problems of known devices. Specifically, it is desirable to provide a spectrometer that enables temperature-robust internal calibration for miniaturized NIR spectroscopy. [Means for solving the problem]

[0011] This problem is solved by a spectrometer device having the features of an independent patent claim. Advantageous embodiments that can be realized in a single aspect or in any combination are described in the dependent claims and throughout the specification.

[0012] In a first aspect of the present invention, a spectrometer device for acquiring spectral information relating to at least one object is disclosed.

[0013] The spectrometer is: — with at least one detector for detecting light from an object; — with at least one optical filter configured to transfer incident light within at least one selected wavelength range to a detector; — with at least one light source configured to emit light in at least one optical spectral range; —At least one sample interface configured to allow light emitted from a light source to illuminate an object held by the sample interface, and to allow light from the object held by the sample interface to propagate to a detector via an optical filter, the sample interface comprising at least one module cover window including at least one substrate, the module cover window comprising at least one internal calibration target partially covering the substrate, and the at least one sample interface; —At least one first optical path, the first optical path being configured to allow light emitted from the light source to propagate to the detector via the optical filter by passing through the sample interface at least once; —At least one second optical path, the second optical path being configured to allow light emitted from the light source to propagate through the optical filter to the detector by interacting with the internal calibration target at least once, It is equipped with.

[0014] 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.

[0015] 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, as well as at least one item of spectral information, may relate to at least one property characterizing at least one of transmission, absorption, reflection, and 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. The spectrometer device can specifically be formed to record signal intensity with respect to the corresponding wavelength or band of the spectrum, for example, the wavelength interval, where the signal intensity may specifically be provided as an electrical signal that can be used for further evaluation.

[0016] A spectrometer may be, or may comprise, a device that enables the measurement of at least one spectrum, e.g., spectral radiant flux, particularly 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 (unit: 1) relative to at least one reference material, which can describe the properties of the material, e.g., 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.

[0017] 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 object). Additionally or alternatively, at least one spectrometer may be an absorption spectrometer and / or a transmission spectrometer, or may include them. In particular, spectral measurement by the spectrometer may include measuring reflectance 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.

[0018] The spectrometer may comprise at least one light source, for example, which may be 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 configured to detect electromagnetic radiation, in particular 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 further comprise at least one wavelength-selective element, such as at least one of a diffraction grating, a prism, and an optical filter (e.g., 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 can be used to separate incident light into the spectrum of constituent wavelength signals, the intensity of each of these 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.

[0019] 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.

[0020] As used herein, the term “spectroscopic information” (also called “spectral information” or “an item of spectral information”) 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, without limitation, specifically refer to an item of information relating to radiation emitted by an 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 characterizing (e.g., qualitatively and / or quantitatively) at least one of the transmission, absorption, reflection, and emission of at least one object. For example, at least one item of spectral information may include, for example, at least one piece of intensity information, e.g., information relating to the intensity of light transmitted, absorbed, reflected, or emitted by an object, as a function of one wavelength or a subrange of wavelengths over one or more wavelengths, e.g., 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.

[0021] A spectrometer may be configured to acquire at least one spectrum or at least a portion of a spectrum of detection light propagating from an object to the spectrometer. The spectrum can describe the units of the radiative measurement of the spectral radiant flux in units of, for example, watts per nanometer (W / nm), or in other units, such as a function of the wavelength of the detection light. Thus, the spectrum can describe the optical output of light in a particular wavelength band, such as the near-infrared (NIR) spectral region. 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 also show the power spectral density and / or spectral radiant flux of an object (e.g., of the object, with respect to a reference object, specifically of the object), such as the transmittance and / or reflectance of the object.

[0022] 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.

[0023] 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 area of ​​the detector.

[0024] 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 both 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, such as a human being, 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.

[0025] A spectrometer apparatus comprises at least one detector for detecting light from an object, in particular detection light. 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 at least one of physical, chemical, or biological parameters. 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 physical, chemical, or biological parameters. 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 by the detector directly or indirectly to at least one evaluation unit, and thus 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 processed or preprocessed before further use by filtering, etc. Thus, the detector may comprise 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.

[0026] 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 also called "detection light." 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 at least one of 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, which provides 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.

[0027] 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.

[0028] 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.

[0029] An array of photosensitive elements may be designed to generate detector signals, preferably electronic signals, related to the intensity of incident light irradiated onto each individual photosensitive element. The detector signals may be analog and / or digital signals. 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 be an active pixel sensor, preferably adapted 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.

[0030] 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 contained within the array. The electrical signals provided by the array of the spectrometer can be transferred to an evaluation unit.

[0031] The spectrometer apparatus further comprises at least one optical filter configured to transfer incident light within at least one selected wavelength range to a detector. 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 sense. 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, and the transmission of light having wavelengths outside the selected wavelength range may be prevented at least partially, such as by having a reduced 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 sense, and specifically, the term may refer to at least one wavelength range that the optical filter allows light to transmit. 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 having reduced 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 a wavelength range of 10 to 100 nm, specifically 10 to 50 nm, more specifically a width of 20 nm, most specifically 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.

[0032] The transmission profile of an optical filter may depend on the angle of incidence. 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, without limitation, to transmittance as a function of wavelength. Specifically, a transmission profile can indicate the optical transmission capability of an optical filter as a function of wavelength. A transmission profile may include a numerical representation of the optical transmission capability of an optical filter as a function of wavelength. For example, a transmission profile may include a numerical representation quantifying 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 quantifying the amount of light transmitted by the optical filter to the amount of incident light. For example, a transmission profile may include a ratio quantifying 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. As used herein, the term “angle of incidence” 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 angle at which incident light is incident on the surface normal of the surface of an optical element. The surface normal of a surface 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 an optical filter.

[0033] The spectrometer further comprises at least one light source configured to emit light, also referred to herein as irradiant 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 sense. 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, where the range from 760 nm to 1.5 μm is 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), in particular light with wavelengths from 1 μm to 5 μm, preferably from 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.

[0034] As used herein, the term “light source” 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 any device configured to produce or provide light in the sense defined above. 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).

[0035] 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 irradiation of the object with the irradiation light.

[0036] 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.

[0037] 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.

[0038] The spectrometer apparatus comprises at least one sample interface configured to allow light emitted from a light source to irradiate an object held by the sample interface, and to allow light from the object held by the sample interface to propagate to a detector via an optical filter. As used herein, the term “sample interface” 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 a port of the spectrometer apparatus through which light within the optical spectral range, for example, light from at least one partition of the optical spectral range or the entire optical spectral range, can be incident on the spectrometer apparatus specifically for the purpose of spectral detection and / or de-exit from the spectrometer apparatus for the purpose of irradiating, for example, at least one object. The sample interface can, for example, define an optical surface of a spectrometer (e.g., a surface of a material or a virtual surface) through which irradiated light from the first optical path can travel to reach an object, and / or detected light from the object can travel to reach 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 transparent element, a physical element such as a glass or quartz window, and / or a barrier. The sample interface may be the sample surface itself, or a plane on which the sample can be placed or aligned. The sample interface is located in the optical path of the spectrometer, specifically in the first optical path, and allows irradiated light emitted from a light source to illuminate an object located in front of the spectrometer, specifically in front of the sample interface. As used herein, the term “passing through the sample interface” 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.This term can specifically refer to, without limitation, one or more of the following: propagation to and from the sample interface, crossing the sample interface, and interaction with the sample interface. The emitted light may be incident on the sample interface, for example, at an angle of incidence. The emitted light may interact with the sample interface and leave the sample interface, for example, at an angle of departure. The point of incidence or region to the sample interface may be on the same side as the point of departure or region from the sample interface, or on the opposite side.

[0039] The sample interface comprises at least one module cover window. The term “module” 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, without limitation, to a composite element that provides at least one function within the sample interface. The term “cover” 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, without limitation, to an element configured to at least partially surround at least one other element. The term “window” 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, without limitation, to an optically transparent optical element having a defined refractive index and thickness. The window may provide an interface to the outside of the spectrometer, for example, to the outside of the spectrometer housing. As used herein, the term “module cover window” 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 a module configured to provide at least one covering function and at least one window.

[0040] The module cover window includes at least one substrate. The term “substrate” 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 a base element on which further elements of the sample interface may be applied, such as by coating.

[0041] The substrate may be at least partially transparent in at least one given wavelength range. Specifically, the substrate may contain at least one translucent material. As used herein, the term “translucent” 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 the property of an optical element that partially transmits incident light in at least one wavelength range. Specifically, a translucent optical element may be configured to transmit a portion of the incident light, while the other portion of the incident light may be reflected by the translucent optical element. Specifically, the material of the substrate may be translucent in at least a selected wavelength range. The wavelength range in which the substrate is translucent may be selected to at least partially match the wavelength range of the light source.

[0042] However, the wavelength range of the substrate may differ from that of the light source, and may be, for example, a narrower range. Therefore, the substrate can function at least partially as a window. The substrate may be configured to allow light of at least one wavelength range to pass through according to Snell's law. For example, the substrate may be a glass substrate, such as a transparent glass window. For example, the glass substrate may contain at least one material selected from the group consisting of fused silica, soda lime, borosilicate, sapphire, silicon, germanium, calcium fluoride, magnesium fluoride, barium fluoride, etc. The top and / or bottom surfaces may include an anti-reflective coating (AR coating) to increase the total transmittance, for example, in the wavelength range and angle of incidence (AOI) of interest.

[0043] The substrate may be at least partially structured, for example, by sandblasting. For example, the substrate may be at least partially structured in the region containing the internal calibration target. This structure can ensure a desired reflection profile, such as Lambertian reflection characteristics.

[0044] The module cover window includes at least one internal calibration target that partially covers the substrate.

[0045] 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.

[0046] 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 a spectrometer, and more specifically to at least one calibration target integrated 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 scattering and / or filtering the irradiated light onto the optical filter, without passing through the sample interface.

[0047] An internal calibration target may comprise 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 an ideal case), without limitation. An internal calibration target may have diffuse scattering properties and a non-zero reflectivity. Specifically, an internal calibration target may function as a diffuse mirror. An internal calibration target may include 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 may be selected depending on the wavelength of the incident light, for example, 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.

[0048] 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.

[0049] For example, an internal calibration target may include: at least one layer of polytetrafluoroethylene (PTFE), at least one optical coating such as a white surface coating available from Nextel® Suede Coating 3101, a dielectric coating, at least one partially reflective dielectric mirror, at least one metallic coating or metallic foil including one or more of gold, silver, aluminum, and chromium, and at least one beam splitter. For example, the internal calibration target may be applied to the substrate by one or more of spray coating, stamping, printing, bonding, and at least one squeegee process.

[0050] The substrate is at least partially covered by an internal calibration target. The internal calibration target can cover 0.1 to 99.9% of the substrate, more specifically 0.5 to 25%, and more specifically 1 to 10%. For example, 1 to 10% of the substrate may be covered by the internal calibration target, and the remainder, for example 99 to 90%, can be used for the first optical path for measuring the object.

[0051] The internal calibration target may include at least one white reflective element, such as a coating, film, or foil. As used herein, the term “white” is broad 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, without limitation, characterize the reflection of the element, i.e., the reflection is essentially wavelength-independent in a wavelength range of interest, and in particular, there may be no major absorption peak in the reflection spectrum of the element in a given wavelength range. As used herein, the term “white reflective element” is broad 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, without limitation, refer to a material layer having at least a partially diffuse reflective surface. A white reflective element can provide a diffuse reflective surface. A white reflective element may be translucent in at least one given wavelength range. The wavelength range in which the white reflective element is translucent may be selected to at least partially match the wavelength range of the light source. However, the wavelength range of the white reflector may differ from that of the light source, for example, it may be a narrower range. The white reflector may be configured to reflect and / or transmit incident light at least partially. The white reflector may include at least one layer of polytetrafluoroethylene (PTFE) and one or more optical coatings, such as a white surface coating (e.g., a white surface varnish available from Nextel® Suede Coating 3101).

[0052] The white reflective element may be directly placed on the substrate. As used herein, the term “direct placement” 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 applications where no further elements are interposed between the substrate and the white reflective element. For example, the white reflective element may be coated on the substrate, e.g., spray coated. However, other processes such as stamping, printing, bonding, or at least one squeegee step are also possible.

[0053] The internal calibration target is a carrier element, which may include at least one carrier element for positioning a white reflector on a substrate via it. The term “carrier element” 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 at least one element and / or layer positioned between two other elements, e.g., the substrate and the white reflector. The carrier element may be configured to provide at least one support function for mounting at least one further element of the internal calibration target on the substrate. For example, the white reflector and the carrier element may function together as an internal calibration target, and / or the carrier element may support the white reflector. The carrier element may be diffusely reflective in at least one wavelength range. The carrier element may include at least one reflective material. The white reflector may be translucent. The carrier element may be configured to scatter light upon transmission through the white reflector. Thus, reflective carriers can increase the overall reflectivity. The white reflective element can be attached to the carrier element by, for example, using a transparent adhesive such as epoxy adhesive, or by at least one spray coating (varnish) process. However, other processes are also possible.

[0054] In one embodiment, the module cover window may include a stack. The stack may include at least a white reflective element, a carrier element, and a substrate. In one embodiment, the stack may comprise a carrier element on which a white reflective element is coated, and the carrier element is coated directly onto the substrate. For example, the carrier element comprises at least one metal layer containing one or more of gold, silver, aluminum, and chromium, and the metal layer is coated onto the substrate by, for example, at least one thin-film process. In one embodiment, the stack may comprise a carrier element on which a white reflective element is coated, and is attached to the substrate by using at least one adhesive. For example, the carrier element comprises a metal film fixed to the substrate by an adhesive. In one embodiment, the stack may comprise a carrier element attached to the substrate by using at least one adhesive, and a white reflective element attached to the carrier element by using at least one transparent adhesive. For example, the carrier element comprises a metal film fixed to the substrate by an adhesive, where the white reflective element is a reflective coating fixed to the carrier element by a transparent adhesive.

[0055] For example, a white reflective element may include at least one layer of PTFE, and a carrier element may further include at least one piece of aluminum foil that functions as a reflector. The PTFE layer may be attached to the aluminum foil using a transparent adhesive. The PTFE may function as a diffuser and, in combination with the reflector, function as an internal calibration target.

[0056] The module cover window is structured at least partially. As used herein, the term “structured” 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, without limitation, a non-uniform distribution of a single element.

[0057] For example, the internal calibration targets may be unevenly distributed on the substrate. For instance, the internal calibration targets may include at least one pattern. As used herein, the term “pattern” 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, without limitation. The pattern may be at least one pattern selected from the group consisting of dot patterns, checkerboard patterns, random patterns, or other patterns, and characterizes macroscopic two-dimensional uniformity across the surface area of ​​the calibration target. The pattern may be embodied to cover only a portion of the substrate. For example, a white reflective element may be structured to scatter light within a given wavelength range.

[0058] As described above, the substrate may be structured at least partially by sandblasting or the like. The substrate may be partially or completely structured to have a desired reflection profile (e.g., Lambertian reflection). The substrate may be partially covered with a metal layer, which may also function as a shielding layer.

[0059] 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 by 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.

[0060] As used herein, the term “first 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 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 the 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 then 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 leave the spectrometer, particularly at the sample interface, from the housing of the spectrometer in order to illuminate an object located outside 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, and then to the optical filter and subsequently to the 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.

[0061] As used herein, the term “second 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 an optical path that does not interact with the irradiating light at an object. 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 the irradiating light emitted from the 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, the irradiating light emitted from the light source can reach the detector via an internal calibration target and then an optical filter 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 can be directed directly or indirectly to an internal calibration target by reflection, refraction, and / or dispersion from a light source, 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 a 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.

[0062] The module cover window may include at least one stray light suppression element configured to suppress unwanted light striking an object and / or to suppress stray light. The substrate may be at least partially covered by the stray light suppression element. As used herein, the term “stray light” 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, without limitation, light originating from at least one light source distinct from the object that produces a signal in addition to a measurement signal dedicated to a selected wavelength range. For example, stray light may be generated by one or more of interference, reflection, and scattering in at least one element of the spectrometer (e.g., an optical grating, housing, etc.). As used herein, the term “stray light suppression element” 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, without limitation, at least one element configured to reduce stray light. The stray light suppression element may be made of a black material. The stray light suppression element may have near-zero reflectance and transmittance. The stray light suppression element can cover a portion of the substrate, for example, the area where the internal calibration target is located. The stray light suppression element may be part of the module cover window. The stray light suppression element may include a coating, which may be made from a black varnish, e.g., Nextel® Black Velvet. The stray light suppression element may be applied to the substrate by one or more of the following: spray coating, stamping, printing, or at least one squeegee process. For example, the stray light suppression element may be placed directly on the substrate. For example, the stray light suppression element may be placed on the substrate via at least one further carrier element. For example, the further carrier element may include at least one element selected from the group consisting of at least one metal foil, e.g., aluminum foil (e.g., Acktar®), at least one plastic foil, or at least one plastic film. The further carrier element may be attached to the substrate using at least one adhesive material.Since the coating shape can be pre-treated and / or masks are not required, the use of additional carrier elements may be advantageous.

[0063] The white reflective element may be placed adjacent to the stray light suppression element. For example, the white reflective element and the stray light suppression element may be placed in parallel on the substrate. For example, both the white reflective element and the stray light suppression element may be a coating on the substrate (they are adjacent to each other).

[0064] For example, a white reflective element and a stray light suppression element are arranged within a stack of the module cover window. The white reflective element may be positioned to at least partially cover the stray light suppression element. For example, the stack may include a white reflective element applied on the stray light suppression element and may optionally be attached to further carrier elements mounted on a substrate. For example, the white reflective element is attached to the stray light suppression element via at least one transparent adhesive. Alternatively, the stray light suppression element may be at least one opaque adhesive, or may include one. The white reflective element can be bonded to (further) carrier elements via an opaque adhesive. This prevents partial absorption of light in the adhesive layer. This prevents the absorption spectrum of the adhesive from appearing in the reflectance spectrum of the white reflective material.

[0065] A spectrometer apparatus may include at least one evaluation unit configured to evaluate at least one detector signal generated by a detector. 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. 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.

[0066] 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, which may perform a predetermined transformation to determine spectral information about an object using at least one detector signal, for example, to determine at least one spectral piece of 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.

[0067] 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:

[0068]

number

[0069] 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.

[0070] 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. The calibration information items may be stored in the spectrometer's data storage device and / or a data storage device accessible to the spectrometer, and can be used to determine the spectral information of an object using the spectrometer. Specifically, the calibration information items may 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, such as 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.

[0071] 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

[0072] 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

[0073] 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.

[0074] 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).

[0075] 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 with each other in such a proportional manner.

[0076] 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 the measurement spectrum. Calibration of a spectrometer can improve and / or maintain the accuracy of measurements performed using the calibrated spectrometer.

[0077] 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.

[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 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.

[0080] Specifically, the calibration information items are:

number

[0081] This method may, in particular, include repeating steps II. to IV. for multiple wavelengths i.

[0082] 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.

[0083] 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.

[0084] 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 device according to the present invention (e.g., any one of the embodiments disclosed above and / or any one of the embodiments disclosed in more detail below). i The steps involve determining the spectral information of an object by using [this method]. Includes.

[0085] 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

[0086] This method may include repeating steps ii. to iv. for multiple wavelengths i.

[0087] 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 to cause the 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 further 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 further below).

[0088] In a further aspect of the present invention, a computer-readable storage medium, specifically a non-temporary computer-readable storage medium, is disclosed, which, when executed by a computer or computer network, contains instructions causing the computer or computer network to perform a method for calibrating a spectrometer device according to the present invention (e.g., any one of the embodiments disclosed above and / or any one of the embodiments disclosed further 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., any one of the embodiments disclosed above and / or any one of the embodiments disclosed further below).

[0089] 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).

[0090] 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.

[0091] 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 dispersive element) that exhibits a dependence of the spectrum on, for example, the x-axis and / or y-axis, on the direction from which the light is collected (e.g., the direction from the angle of incidence). As an example, the dispersive element may be an optical filter, specifically an interference filter (e.g., a set of 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.

[0092] 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.

[0093] 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, an 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 can, specifically, result in scaling of the calibration information item ci, but can be made so as not to result in undesirable temperature dependence.

[0094] Further aspects of the present invention disclose the use of a spectrometer apparatus according to the present invention in applications selected from the group consisting of: infrared detection applications; spectroscopic applications; exhaust gas monitoring applications; combustion process monitoring applications; pollution monitoring applications; industrial process monitoring applications; mixing or blending process monitoring applications; chemical process monitoring applications; food processing process monitoring applications; food preparation process monitoring applications; water quality monitoring applications; air quality monitoring applications; quality control applications; temperature control applications; motion control applications; exhaust control applications; gas detection applications; gas analysis applications; motion detection applications; chemical detection applications; mobile applications; medical applications; mobile spectroscopic applications; food analysis applications; agricultural applications, particularly characterization of soil, silage, feed, crops or agricultural products, and monitoring of plant health; plastic identification and / or recycling applications; healthcare and / or beauty applications, particularly measurement of skin moisture content and / or oxygen saturation (e.g., animal or human skin), measurement of oxygen saturation in blood, urine, saliva or other bodily fluids, non-invasive blood glucose measurement or tracking applications, long-term blood glucose measurement or tracking applications, and body temperature measurement or tracking applications.

[0095] 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.

[0096] 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.

[0097] 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 can 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.

[0098] In summary, without prejudice to further possible embodiments, the following embodiments may be conceivable: Embodiment 1: A spectrometer apparatus for acquiring spectral information relating to at least one object, comprising: — with at least one detector for detecting light from an object; — comprising at least one optical filter configured to transfer incident light within at least one selected wavelength range to the detector; — with at least one light source configured to emit light in at least one optical spectral range; —At least one sample interface configured to allow light emitted from the light source to illuminate an object held by the sample interface, and to allow light from the object held by the sample interface to propagate through the light filter to the detector, the sample interface comprising at least one module cover window including at least one substrate, the module cover window comprising at least one internal calibration target partially covering the substrate, and the at least one sample interface; —At least one first optical path, the first optical path being configured to allow light emitted from the light source to propagate to the detector via the optical filter by passing through the sample interface at least once; —At least one second optical path, the second optical path being configured to allow light emitted from the light source to propagate through the optical filter to the detector by interacting with the internal calibration target at least once, A spectrometer device equipped with the following features.

[0099] Embodiment 2: A spectrometer apparatus according to a prior embodiment, wherein the internal calibration target includes at least one diffuse reflecting surface.

[0100] Embodiment 3: A spectrometer apparatus according to any one of the prior embodiments, wherein the internal calibration target functions as a diffuse mirror and the internal calibration target has a surface roughness configured to produce a Lambertian reflection profile.

[0101] Embodiment 4: A spectrometer apparatus according to any one of the preceding embodiments, wherein the internal calibration target comprises: at least one layer of polytetrafluoroethylene (PTFE), at least one optical coating such as a white surface coating, a dielectric coating, at least one partially reflective dielectric mirror, at least one metallic coating or metal foil including one or more of gold, silver, aluminum, and chromium, and at least one beam splitter.

[0102] Embodiment 5: A spectrometer apparatus according to any one of the prior embodiments, wherein the internal calibration target includes at least one white reflective element, or at least one white reflective element and at least one carrier element.

[0103] Embodiment 6: A spectrometer apparatus according to a prior embodiment, wherein the carrier element is diffusely reflective in at least one wavelength range, and the white reflective element is semi-transparent in at least one given wavelength range.

[0104] Embodiment 7: A spectrometer apparatus according to any one of the preceding embodiments, wherein the module cover window is at least partially structured, the internal calibration target includes at least one pattern, the pattern is arranged to partially cover the substrate, and the pattern is at least one pattern selected from the group consisting of a dot pattern, a checkerboard pattern, a random pattern, or any other pattern, and is a pattern that characterizes macroscopic two-dimensional uniformity across the surface area of ​​the calibration target.

[0105] Embodiment 8: A spectrometer apparatus according to any one of the preceding embodiments, wherein the substrate is a glass substrate.

[0106] Embodiment 9: A spectrometer apparatus according to any one of the prior embodiments, wherein the substrate is at least partially covered by the internal calibration target, the internal calibration target covering 0.1 to 99.9% of the substrate, specifically 0.5 to 25% of the substrate, and more specifically 1 to 10% of the substrate.

[0107] Embodiment 10: A spectrometer apparatus according to any one of the prior embodiments, wherein the module cover window includes at least one stray light suppression element configured to suppress unwanted light striking an object and / or to suppress stray light.

[0108] Embodiment 11: A spectrometer apparatus according to a prior embodiment, wherein the stray light suppression element has a reflectance and transmittance of approximately zero.

[0109] Embodiment 12: A spectrometer apparatus according to one of the two preceding embodiments, wherein the stray light suppression element covers a portion of the substrate.

[0110] Embodiment 13: A spectrometer apparatus according to any one of the three preceding embodiments, wherein the stray light suppression element is disposed directly on the substrate, or the stray light suppression element is disposed on the substrate via at least one further carrier element.

[0111] Embodiment 14: A spectrometer apparatus according to any one of the four preceding embodiments, wherein the stray light suppression element includes a coating, and the coating is made from black varnish.

[0112] Embodiment 15: A spectrometer apparatus according to any one of the five preceding embodiments, wherein the stray light suppression element is applied to the substrate by one or more of the following processes: spray coating, stamping, printing, and at least one squeegee process.

[0113] Embodiment 16: A spectrometer apparatus according to any one of the six preceding embodiments, wherein the stray light suppression element is arranged on the substrate via a further carrier element, and the further carrier element includes at least one element selected from the group consisting of: at least one metal foil such as aluminum; at least one plastic foil; and at least one plastic film.

[0114] Embodiment 17: A spectrometer apparatus according to a prior embodiment, wherein the further carrier elements are attached to the substrate using at least one adhesive material.

[0115] Embodiment 18: A spectrometer according to any one of the preceding embodiments, wherein the spectrometer is a near-infrared spectrometer.

[0116] Embodiment 19: A spectrometer according to any one of the prior embodiments, wherein the emitted light has an optical spectral range that is at least partially located in the near-infrared spectral range.

[0117] Embodiment 20: A spectrometer according to any one of the prior embodiments, comprising at least one evaluation unit configured to evaluate at least one detector signal generated by the detector.

[0118] Embodiment 21: 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 iThe 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,i By using this, at least one calibration information item c i The steps to determine, Methods that include...

[0119] Embodiment 22: 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, the 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. 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 a prior embodiment. i The steps include determining the spectral information of the object by using the following: Methods that include...

[0120] Embodiment 23: Use of a spectrometer apparatus according to any one of the preceding embodiments relating to a spectrometer apparatus, the use of a spectrometer apparatus selected from the group consisting of: infrared detection applications; spectroscopic applications; exhaust gas monitoring applications; combustion process monitoring applications; pollution monitoring applications; industrial process monitoring applications; mixing or blending process monitoring; chemical process monitoring applications; food processing process monitoring applications; food preparation process monitoring; water quality monitoring applications; air quality monitoring applications; quality control applications; temperature control applications; motion control applications; exhaust control applications; gas detection applications; gas analysis applications; motion detection applications; chemical detection applications; mobile applications; medical applications; mobile spectroscopic applications; food analysis applications; agricultural applications, in particular characterization of soil, silage, feed, crops or agricultural products, monitoring of plant health; plastic identification and / or recycling applications; healthcare and / or cosmetic applications, in particular determination of moisture content and / or oxygen saturation of skin, e.g., animal or human skin, determination of oxygen saturation in blood, urine, saliva or other body fluids, non-invasive blood glucose measurement or tracking applications, long-term blood glucose measurement or tracking applications, body temperature measurement or tracking applications. [Brief explanation of the drawing]

[0121] 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.

[0122] In the diagram: [Figure 1]This figure schematically illustrates an embodiment of a spectrometer device for acquiring spectral information about at least one object. [Figure 2] This figure schematically illustrates various embodiments of the sample interface of a spectrometer. [Figure 3] This figure schematically illustrates various embodiments of the sample interface of a spectrometer. [Figure 4] Figures 4A to 4C schematically illustrate various embodiments of the sample interface of a spectrometer. [Figure 5] Figures 5A to 5C schematically illustrate various embodiments of the sample interface of a spectrometer. [Figure 6] This diagram shows a flowchart illustrating an embodiment of a method for calibrating a spectrometer. [Figure 7] This figure shows a flowchart of an embodiment of the method. [Modes for carrying out the invention]

[0123] Detailed description of the embodiment Figure 1 schematically shows an exemplary embodiment of a spectrometer 110 for acquiring spectral information about at least one object 112. The spectrometer 110 may specifically be a near-infrared spectrometer 114.

[0124] The spectrometer 110 comprises at least one detector 116 for detecting light, in particular detection light 118 from an object 112. The detector 116 may comprise a single optically sensitive element or area, or a plurality of 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 120. Specifically, the spectrometer 110 may comprise at least one evaluation unit 120 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.

[0125] The spectrometer device 110 further includes at least one optical filter 122 configured to transfer incident light within at least one selected wavelength range to the detector 116. The transmission profile of the optical filter 122 may depend on the angle of incidence. As shown in Figure 1, the optical filter 122 can be positioned adjacent to the detector 116, for example by placing the optical filter 122 on top of the detector 116. The optical filter 122 may include, as an example, at least one narrowband-pass filter 124, more specifically a set of narrowband-pass filters 124. The narrowband-pass filter 124 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 124, each narrowband-pass filter 124 may have a narrowband-selective wavelength range that is at least partially different from one another.

[0126] The spectrometer device 110 further includes at least one light source 126 configured to emit light, specifically irradiation light 128, in at least one optical spectral range. For example, the light source 126 may include at least one light-emitting diode (LED) 130. In the example in Figure 1, the irradiation light 128 has an optical spectral range that is at least partially located in the near-infrared spectral range.

[0127] The spectrometer apparatus 110 further comprises at least one sample interface 132 configured to allow light emitted from a light source 126 to irradiate an object 112 held by the sample interface 132, and to allow light from the object 112 held by the sample interface 132 to propagate to the detector 116 via an optical filter 122. The sample interface 132 comprises at least one module cover window 134 including at least one substrate 136, the module cover window 134 including at least one internal calibration target 138 that partially covers the substrate 136. Different embodiments of the sample interface 132 and module cover window 134 are shown in Figures 2 to 6. Therefore, for a detailed description of the sample interface 132 and module cover window 134, please refer to the description in Figures 2 to 6.

[0128] The spectrometer apparatus 110 further comprises at least one first optical path 140 and at least one second optical path 142. The first optical path 140 is configured to allow light emitted from the light source 126, specifically the irradiation light 128, to propagate to the detector 116 via the optical filter 122 by passing through the sample interface 132 at least once. The second optical path 142 is configured to allow light emitted from the light source 126, specifically the irradiation light 128, to propagate to the detector 116 via the optical filter 122 by interacting with the internal calibration target 138 at least once.

[0129] Figures 2 to 6 schematically show different exemplary embodiments of the sample interface 132 of the spectrometer 110. In these exemplary embodiments shown in Figures 2 to 6, the substrate 136 may be a glass substrate.

[0130] In the example in Figure 2, the internal calibration target 138 may include at least one white reflective element 144, such as a coating, film, or foil. The white reflective element 144 can provide a diffuse reflective surface. As shown in Figure 2, the white reflective element 144 may be placed directly on the substrate 136. Furthermore, the module cover window 134 may include at least one stray light suppression element 146 configured to suppress unwanted light hitting the object 112 and / or to suppress stray light. The stray light suppression element 146 may be made of a black material. The stray light suppression element 146 may have near-zero reflectivity and transmittance. The stray light suppression element 146 may cover a portion of the substrate 136, for example, the area where the internal calibration target 138 is located. The stray light suppression element 146 may be part of the module cover window 134. The substrate 136 may be at least partially covered by the stray light suppression element 146. The stray light suppression element 146 may include a coating, which may be made from a black varnish, for example, Nextel® Black Velvet. The stray light suppression element 146 may be applied to the substrate 136 by one or more of the following processes: spray coating, stamping, printing, or at least one squeegee process. For example, as shown in Figure 2, the stray light suppression element 146 may be placed directly on the substrate 136. In the exemplary embodiment of Figure 2, the white reflective element 144 may be placed adjacent to the stray light suppression element 146. For example, the white reflective element 144 and the stray light suppression element 146 may be placed side by side on the substrate 136. For example, both the white reflective element 144 and the stray light suppression element 146 may be coatings placed adjacent to each other on the substrate 136. However, other alternative arrangements are also possible.

[0131] Figure 3 shows an exemplary embodiment of a sample interface 132 similar to the embodiment in Figure 2, in which the stray light suppression element 146 is located on the substrate 136 via at least one further carrier element 148, in which case there is no internal calibration target. For example, the further carrier element 148 may include at least one element selected from the group consisting of: at least one metal foil such as Acktar aluminum foil; at least one plastic foil; and at least one plastic film. The further carrier element 148 can be attached to the substrate 136 using at least one adhesive material 150. The use of the further carrier element 148 may be advantageous because the shape of the coating can be pre-treated and / or masks, etc., are not required.

[0132] In the exemplary embodiments shown in Figures 4A to 5C, the module cover window 134 may include a stack 152. Furthermore, the internal calibration target 138 may include at least one carrier element 154 through which a white reflector 144 is placed on the substrate 136. The stack 152 may include at least the white reflector 144, the carrier element 154, and the substrate 136.

[0133] For example, as shown in Figure 4A, the stack 152 may comprise a carrier element 154 on which a white reflective element 144 is coated, and the carrier element 154 is coated directly onto the substrate 136. For example, the carrier element 154 includes at least one metal layer 156 containing one or more of gold, silver, aluminum, and chromium, and the metal layer 156 is coated onto the substrate 136 by, for example, at least one thin-film process.

[0134] Additionally or alternatively, as shown in Figure 4B, the stack 152 may include a carrier element 154 on which a white reflective element 144 is coated. The carrier element 154 is attached to the substrate 136 by using at least one adhesive 158. For example, the carrier element 154 includes a metal film 160 fixed to the substrate 136 by the adhesive 158.

[0135] Additionally or alternatively, as shown in Figure 4C, the stack 152 may include a carrier element 154 attached to the substrate 136 by using at least one adhesive 158, and a white reflective element 144 attached to the carrier element 154 by using at least one transparent adhesive 162. For example, the carrier element 154 includes a metal film 160 fixed to the substrate 136 by adhesive 158, where the white reflective element 144 is a reflective coating fixed to the carrier element 154 by transparent adhesive 162.

[0136] In the exemplary embodiments shown in Figures 5A to 5C, a white reflective element 144 and a stray light suppression element 146 may be additionally or alternatively arranged within the stack 152 of the module cover window 134. The white reflective element 144 may be positioned to at least partially cover the stray light suppression element 146.

[0137] For example, as shown in Figure 5A, the stack 152 may include a white reflective element 144 coated on a stray light suppression element 146 mounted on a further carrier element 148, which is attached to the substrate 136, for example, via an adhesive 158. The white reflective element 144 can be attached to the stray light suppression element 146 via at least one transparent adhesive 162.

[0138] Alternatively, as shown in Figure 5B, the stray light suppression element 146 may be or include at least one opaque adhesive 164. The white reflective element 144 can be bonded to a further carrier element 148 via the opaque adhesive 164. This prevents partial absorption of light in the adhesive layer 158. This prevents the absorption spectrum of the adhesive 158 from appearing in the reflection spectrum of the white reflective material.

[0139] For example, as shown in Figure 5C, the stack 152 may be implemented similarly to the stack 152 in Figure 5A, and the white reflective element 144 may be positioned to partially cover the stray light suppression element 146.

[0140] Figure 6 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, for example, the embodiment shown in Figure 1 and / or other embodiments disclosed herein. Therefore, please refer to the description of Figure 1 for a description of the spectrometer 110.

[0141] 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 further include additional method steps not described.

[0142] Book: I. A step of providing object 112 (referred to as reference no. 166) to the sample interface 132 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 140 (shown in reference number 168) iThe 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 142 (shown in reference number 170) 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 172) 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.

[0143] Specifically, the calibration information items are:

number

[0144] This method may, in particular, include repeating steps II. to IV. for multiple wavelengths i.

[0145] Figure 7 shows a flowchart of an exemplary embodiment of a method for determining at least one spectral piece of information of at least one object 112 by using a spectrometer 110. In this method, the spectrometer 110 used is a spectrometer 110 according to the present invention, such as according to the embodiment shown in Figure 1 and / or any other embodiment disclosed herein. Therefore, refer to the description of Figure 1 for a description of the spectrometer 110.

[0146] This method includes the following steps that can be executed in a given order. However, different orders are also possible. In particular, one, more than one, or all of the method steps can be carried out once or repeatedly. Furthermore, the method steps may be executed continuously, or one or more of the method steps can be executed with temporal overlap or in parallel and / or in combination. The method can further include additional method steps not described.

[0147] The method is: i providing the object 112 (shown by reference numeral 174) to the sample interface 132, wherein the object 112 includes at least one measurement object; ii irradiating the detector 116 with light having at least one wavelength λ via the first optical path 140, to obtain at least one measurement signal S; i meas,i iii irradiating the detector 116 with light having at least one wavelength λ via the second optical path 142, to obtain at least one reference signal S; i ref,i iv determining the spectroscopic information of the object 112 by using the measurement signal S, the reference signal S, and a calibration information item c determined by using a method for calibrating the spectrometer device 110 according to the present invention, such as the embodiment shown in FIG. 6 and / or other embodiments disclosed in this specification; meas,i ref,i i and includes.

[0148] The spectroscopic information of the object 112 can specifically be one or more of the reflectivity, transmittance, and absorptance of the object 112. For example, the spectroscopic information of the object 112 is the reflectivity R object,i where

Equation

[0149] This method may include repeating steps ii. to iv. for multiple wavelengths i. [Explanation of Symbols]

[0150] List of reference numbers 110 Spectrometer equipment 112 Object 114 Near-infrared spectrometer 116 detectors 118 Detection light 120 evaluation units 122 Light Filters 124 Narrowband Pass Filter 126 Light source 128 Irradiation light 130 Light-Emitting Diodes 132 Sample Interface 134 Module Cover Window 136 circuit boards 138 Internal Calibration Targets 140 1st optical path 142 Second optical path 144 White Reflective Element 146 Stray light suppression element 148 Further carrier elements 150 Adhesive materials 152 stacks 154 carrier elements 156 Metal layer 158 Adhesive 160 Metal Film 162 Transparent Adhesive 164 Opaque Adhesive 166. Provide an external calibration target. 168 Irradiating the detector through the first optical path 170 Irradiate the detector through the second optical path. 172 Determine at least one calibration information item. 174 To provide a measuring object 176 Irradiating the detector through the first optical path 178 Irradiating the detector through the second optical path 180 Determining the spectral information of an object.

Claims

1. A spectrometer (110) for acquiring spectral information relating to at least one object (112): — with at least one detector (116) for detecting light from an object (112); — comprising at least one optical filter (122) configured to transfer incident light within at least one selected wavelength range to the detector (116); — with at least one light source (126) configured to emit light in at least one optical spectral range; - At least one sample interface (132) configured to allow light emitted from the light source (126) to illuminate an object (112) held by the sample interface (132), and to allow light from the object (112) held by the sample interface (132) to propagate to the detector (116) via the light filter (122), wherein the sample interface (132) includes at least one module cover window (1) including at least one substrate (136) 34) comprising, the module cover window (134) comprising at least one internal calibration target (138) that partially covers the substrate (136), the module cover window (134) comprising at least one stray light suppression element (146) configured to suppress unwanted light and / or stray light that strikes the object (112), the stray light suppression element (146) having substantially zero reflectance and transmittance, the stray light suppression element (146) having at least one sample interface (132) that covers a portion of the substrate (136); —At least one first optical path (140), the first optical path (140) is configured to allow light emitted from the light source (126) to propagate to the detector (116) via the optical filter (122) by passing through the sample interface (132) at least once; —At least one second optical path (142), the second optical path (142) is configured to allow light emitted from the light source (126) to propagate through the optical filter (122) to the detector (116) by interacting with the internal calibration target (138) at least once, A spectrometer (110) is provided with the following:

2. The spectrometer apparatus (110) according to claim 1, wherein the internal calibration target (138) includes at least one diffuse reflecting surface.

3. The spectrometer apparatus (110) according to claim 1 or 2, wherein the internal calibration target (138) functions as a diffuser, and the internal calibration target (138) has a surface roughness configured to produce a Lambertian reflection profile.

4. The spectrometer apparatus (110) according to claim 1 or 2, wherein the internal calibration target (138) comprises one or more of: at least one layer of polytetrafluoroethylene (PTFE), at least one optical coating such as a white surface coating, a dielectric coating, at least one partially reflective dielectric mirror, at least one metallic coating or metal foil comprising one or more of gold, silver, aluminum, and chromium, and at least one beam splitter.

5. The spectrometer apparatus (110) according to claim 1 or 2, wherein the internal calibration target (138) comprises at least one white reflector (144), or at least one white reflector (144) and at least one carrier element (154), wherein the carrier element (154) is diffusely reflective in at least one wavelength range, and the white reflector (144) is semi-transparent in at least one given wavelength range.

6. The spectrometer apparatus (110) according to claim 1 or 2, wherein the module cover window (134) is at least partially structured, the internal calibration target (138) includes at least one pattern, the pattern is arranged to partially cover the substrate (136), and the pattern is at least one pattern selected from the group consisting of a dot pattern, a checkerboard pattern, a random pattern, or any other pattern, and is a pattern that characterizes macroscopic two-dimensional uniformity over the surface area of ​​the calibration target.

7. The spectrometer apparatus (110) according to claim 1 or 2, wherein the substrate (136) is a glass substrate.

8. The spectrometer apparatus (110) according to claim 1 or 2, wherein the substrate (136) is at least partially covered by the internal calibration target (138), and the internal calibration target (138) covers 0.1 to 99.9% of the substrate (136).

9. The spectrometer apparatus (110) according to claim 1 or 2, wherein the stray light suppression element (146) is disposed directly on the substrate (136), or the stray light suppression element (146) is disposed on the substrate (136) via at least one further carrier element (148).

10. The spectrometer apparatus (110) according to claim 1 or 2, wherein the stray light suppression element (146) includes a coating, the coating is made of black varnish, and / or the stray light suppression element (146) is applied to the substrate (136) by one or more of the following processes: spray coating, stamping, printing, and at least one squeegee process.

11. The spectrometer apparatus (110) according to claim 1 or 2, wherein the stray light suppression element (146) is disposed on the substrate (136) via a further carrier element (148), the further carrier element (148) comprises at least one element selected from the group consisting of: at least one metal foil such as aluminum; at least one plastic foil; and at least one plastic film, and the further carrier element (148) is attached to the substrate (136) using at least one adhesive material (150).

12. A method for calibrating a spectrometer (110), wherein the spectrometer (110) is a spectrometer (110) according to claim 1 or 2, and the method is: I. A step of providing an object (112) to the sample interface (132) 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 (140) 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 (142) 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...

13. 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 the object (112) to a sample interface (132), wherein the object (112) includes at least one measuring object; ii. irradiating the detector (116) with light having at least one wavelength λ via the first optical path (140) to obtain at least one measurement signal S ｉ ; and ｍｅａｓ,ｉ a step iii. Through the second optical path (142), 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 device (110) according to claim 12. ｉ The steps include determining the spectral information of the object (112) by using the following: Methods that include...

14. Use of the spectrometer (110) according to claim 1 or 2 relating to the spectrometer (110), the use of the spectrometer (110) according to claim 1 or 2, the use of the spectrometer (110) according to: infrared detection applications; spectroscopic applications; exhaust gas monitoring applications; combustion process monitoring applications; pollution monitoring applications; industrial process monitoring applications; mixing or blending process monitoring; chemical process monitoring applications; food processing process monitoring applications; food preparation process monitoring; water quality monitoring applications; air quality monitoring applications; quality control applications; temperature control applications; motion control applications; exhaust control applications; gas detection applications; gas analysis applications; motion detection applications; chemical detection applications; mobile applications; medical applications; mobile spectroscopic applications; food analysis applications; agricultural applications, in particular characterization of soil, silage, feed, crops or agricultural products, monitoring of plant health; plastic identification and / or recycling applications; healthcare and / or cosmetic applications, in particular determination of moisture content and / or oxygen saturation of skin, e.g., animal or human skin, determination of oxygen saturation in blood, urine, saliva or other bodily fluids, non-invasive blood glucose measurement or tracking applications, long-term blood glucose measurement or tracking applications, body temperature measurement or tracking applications.

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