Setting up LED temperature measurement via a buffered direct injection (BDI) circuit

Abstract

A spectroscopic device (110) and a method for obtaining spectroscopic information of at least one object (112) are disclosed. The spectroscopic device (110) includes the following components: i. at least one light source (114) that generates illumination light (116) that illuminates an object (112); ii. at least one detector (128) that detects the detection light (130) from the object (112) and generates at least one detector signal; iii. at least one driving unit (138) for electrically driving the light source (114); iv. at least one multi-channel readout integrated circuit (139), each channel of the multi-channel readout integrated circuit (139) comprising at least one buffered direct injection (BDI) circuit (141), configured for readout of a detector signal, the BDI circuit (141) configured to generate at least one information related to an electrically measurable quantity required to drive the light source (114), the multi-channel readout integrated circuit (139) including at least one multi-channel readout application-specific integrated circuit (ASIC) (142), the ASIC (142) configured to synchronously sample the detector signal and the information related to the electrically measurable quantity required to drive the light source (114); and v. At least one evaluation unit (136) for evaluating at least one detector signal generated by the detector (128) and deriving spectroscopic information of the object (112) from the detector signal, wherein the evaluation unit (136) is configured to take into account information regarding electrically measurable quantities required to drive the light source (114) when deriving the spectroscopic information from the detector signal.

Description

[Technical Field]

[0001] The present invention relates to a spectroscopic device for obtaining spectroscopic information about at least one object and a method for obtaining spectroscopic information about at least one object. Furthermore, the present invention relates to a computer program and a computer-readable storage medium for carrying out the method. Such devices and methods are typically used for surveillance or monitoring purposes, particularly in the infrared (IR) spectral region, especially the near-infrared (NIR) spectral region, and in the visible (VIS) spectral region, e.g., spectral regions that mimic human color vision. However, further applications are possible. [Background technology]

[0002] Spectroscopic devices are known as efficient tools for obtaining the spectral characteristics of an object when it emits, illuminates, reflects, or absorbs light, and thus can aid in the analysis of samples and other tasks where information about the object's spectral characteristics is important.

[0003] Typically, in a spectroscopic device, spectral information is obtained via one or more detectors and one or more wavelength-selective optical elements (e.g., one or more dispersive optical elements, bandpass filters, prisms, gratings, interferometers, etc.). The detectors can include any type of light-sensitive element, such as single or multiple pixel detectors, line detectors, or array detectors with one- or two-dimensional pixel arrays. Furthermore, the spectroscopic device may include one or more light sources. Thus, spectroscopy typically uses tunable light sources (e.g., lasers) and / or broadband emitting light sources (e.g., halogen gas-filled bulbs and / or hot wires). However, additionally or alternatively, other light sources have also been proposed in the visible light range, such as light-emitting diodes (LEDs).

[0004] For example, US 2010 / 208261 A1 describes an apparatus for measuring at least one optical property of a sample. The apparatus includes an adjustable excitation light source for irradiating the sample with excitation light. The apparatus further includes a detector for detecting detection light emanating from the sample. The excitation light source includes a light emitting diode array, at least a portion of which is configured as a single crystal light emitting diode array. The single crystal light emitting diode array includes at least three light emitting diodes, each having a different emission spectrum.

[0005] US 8,164,050 B2 describes a multi-channel light source assembly for downhole spectroscopy having individual light sources that generate optical signals across a range of wavelengths. A combining assembly optically combines the generated signals into a combined signal, and a routing assembly splits the combined signal into a reference channel and a measurement channel. Control circuitry electrically connected to the light sources modulates each light source at a unique or independent frequency during operation.

[0006] Furthermore, US Pat. No. 7,061,618 B2 describes an integrated spectroscopy system, in some examples of which an integrated tunable detector is provided using one or more Fabry-Perot tunable filters. In other examples, an integrated tunable light source is used, combining one or more diodes, such as superlaminant light emitting diodes (SLEDs), with a Fabry-Perot tunable filter or etalon.

[0007] Furthermore, US Pat. No. 5,475,221 A describes an optical device that uses an array of light-emitting diodes controlled in a multiplexing manner to replace conventional broadband light sources in devices such as spectrometers.

[0008] Generally, spectroscopic devices are subject to internal and external factors, including environmental factors, which can affect the results of spectroscopic measurements. To correct or compensate for these effects, various calibration and / or correction methods are known. These calibration methods may be performed once or multiple times under laboratory conditions, e.g., during production. However, several online calibration techniques are also known, which may perform one or more correction and / or calibration steps between or during two spectroscopic measurements.

[0009] Patent document 5 (US 09360366 B1) discloses a self-referencing spectrometer that uses a shared aperture as an optical input to simultaneously automatically calibrate and measure the optical spectrum of a physical object. The simultaneous measurement and self-calibration capabilities allow the spectrometer to be used as a spectrometer that can be attached to a mobile computing device without the need for offline calibration using an external reference light source. The acquired spectral information and image data can be distributed via a wireless communication network through the mobile computing device.

[0010] Patent document 6 (DE 102014013848 B4) discloses a microspectrometer system and calibration method, including a near-infrared (NIR) microspectrometer for mobile applications for battery-powered terminals, which overcomes the miniaturization and portability limitations of the aforementioned system configurations. A miniaturized NIR spectrometer should be designed without active temperature stabilization. Instead, according to the invention, the spectral sensitivity function (QE) is recorded at multiple levels within the expected operating temperature range as part of a temperature calibration process at the factory. λ) = f(T); measured by the integrated temperature sensor).

[0011] Patent Document 7 (WO 2019 / 191698 A2) relates to a self-referencing spectrometer for simultaneously measuring a background or reference spectral density and a sample or other spectral density. The self-referencing spectrometer includes an optically coupled interferometer that receives an input beam and generates a first interference beam along a first optical path and a second interference beam along a second optical path. Each interference beam is generated prior to output from the interferometer. The spectrometer further includes a detector that simultaneously detects a first interference signal generated from the first interference beam and a second interference signal generated from the second interference beam, and a processing unit configured to process the first interference signal and the second interference signal and use the second interference signal as a reference signal in processing the first interference signal.

[0012] Patent Document 8 (US 20210293620 A1) discloses a spectrometer having the following components: an illumination device that illuminates a spectroscopic measurement region; a detection unit that detects electromagnetic radiation from the spectroscopic measurement region; and a spectroscopic element arranged in an optical path between the illumination device and the detection unit. The illumination device has the following components: a light-emitting diode having a first central wavelength that is designed to emit a first electromagnetic wave having a first spectrum; and a light-emitting element that converts a first component of the first electromagnetic wave having the first spectrum into a second electromagnetic wave having a second spectrum. The first central wavelength is 550 nm, 3000 nm, or a value between 550 nm and 3000 nm. The first spectrum and the second spectrum overlap.

[0013] Patent document 9 (US 06667802 B2) discloses a method for calibrating a spectroscopic inspection system, the method including the steps of providing a plurality of packages, each package containing a group of items, each group of items having a known composition, measuring the reflectance values ​​of each group of items to obtain a reference reflectance value set, normalizing the reference reflectance value set to create a normalized reference reflectance value set, and storing the normalized reference reflectance value set.

[0014] Patent document 10 (US 06717669 B2) discloses an auto-calibration spectrometer and method for measuring the transmittance or reflectance of a sample against wavelength without requiring long-term calibration. Reflection and transmission spectrometers, as well as auto-calibration methods for use therewith, are disclosed. A lens or similar optical element is used to focus light onto a sample, reflect the light that strikes the sample, and transmit the light reflected from the sample. Monitoring the light reflected from the first lens and sample provides very useful information about the system response versus time. The light reflected from the first lens and sample is monitored and used to correct for changes in the system over time.

[0015] Patent document 11 (US 09448114 B2) discloses a spectrometer including multiple isolated optical channels. These isolated optical channels include multiple isolated optical paths. The isolated optical paths reduce crosstalk between the optical paths, improving resolution while shortening the overall length of the spectrometer. In many embodiments, the isolated optical paths include isolated parallel optical paths, which can significantly shorten the overall length of the device. In many embodiments, each isolated optical path travels from a filter in a filter array, through a lens in a lens array, through a channel in a support array, and to a region of a sensor array. Each region of the sensor array includes multiple sensor elements, and the position of each sensor element corresponds to the wavelength of light received based on the angle of light received at that position, the focal length of the lens, and the center wavelength of the filter.

[0016] Patent document 12 (US 10,841,563 B1) discloses a sensor and a sensor platform for an autonomous system. The sensor and its platform detect and collect data, process signals or data, and make decisions locally at the detection point. More specifically, the sensor and its platform combines data from different sensor data sets and mimics human-like decision-making capabilities through a series of data processing processes that enable autonomous decision-making. Additionally, the sensor platform combines multiple sensors as a meta-sensor with the functionality of multiple sensors arranged on a common carrier or platform.

[0017] Tetzlaff T. et al. (2018) in their paper entitled "Hardware Implementation of Junction Temperature Estimation by Measuring the Forward Voltage of an LED" (19th International Conference on Thermal, Mechanical, and Multiphysics Simulation and Experiments in Microelectronics and Microsystems (EuroSimE)) describe how to extend an LED driver circuit with measurement components and signal processing hardware to accurately detect the junction temperature of an LED. This information can be used by the driver to control the current and therefore the temperature of the LED device. The focus of this scientific paper is the measurement of LED temperature based on measuring the forward voltage of the LED, as described in .

[0018] Despite the advantages offered by known methods and devices, several technical challenges remain in the field of spectroscopy and spectroscopic devices, especially in the near-infrared region. In particular, optoelectronic components such as light sources, detectors, and readout electronics generally have a strong temperature dependency. If the temperature dependency is not corrected, drift due to temperature changes can cause a decrease in the measurement reproducibility of the spectroscopic device.

[0019] Generally, these technical challenges can be avoided by stabilizing the temperature-sensitive optoelectronic components with additional hardware (e.g., thermoelectric coolers) or by monitoring and compensating for temperature changes (e.g., by direct monitoring or by monitoring changes in the electrical and optical properties of the components).

[0020] However, in the latter case, the monitored characteristics (e.g., voltage, current, resistance, power consumption, optical efficiency, spectral shift, etc.) may have different characteristics. Monitoring each of these characteristics may require different electrical circuits and different electrical components. Furthermore, the changes in these characteristics due to temperature changes may be very small compared to their initial values. Therefore, the resolution of the monitoring system must generally be high. In summary, these constraints can lead to complex, expensive systems with large footprints. Such complex systems are generally not feasible for size- and cost-sensitive applications. [Prior art documents] [Patent documents]

[0021] [Patent Document 1] US 2010 / 208261 A1 [Patent Document 2] US 8,164,050 B2 [Patent Document 3] US 7,061,618 B2 [Patent Document 4] US 5,475,221 A [Patent Document 5] US 09360366 B1 [Patent Document 6] DE 102014013848 B4 [Patent Document 7] WO 2019 / 191698 A2 [Patent Document 8] US 20210293620 A1 [Patent Document 9] US 06667802 B2 [Patent Document 10] US 06717669 B2 [Patent Document 11] US 09448114 B2 [Patent Document 12] US 10 841 563 B1 [Non-patent literature]

[0022] [Non-Patent Document 1] (Tetzlaff T. et al. (2018), "Hardware Implementation of LED Junction Temperature Estimation by Measuring Forward Voltage," Paper presented at the 19th International Conference on Thermal, Mechanical, and Multiphysics Simulation and Experimentation in Microelectronics and Microsystems (EuroSimE) Summary of the Invention [Problem to be solved by the invention]

[0023] It is therefore desirable to provide an apparatus and a method that at least partially solves the above technical problems. In particular, it is an object of the present invention to provide a spectroscopic apparatus and a method for acquiring spectroscopic information of at least one object that minimizes the hardware effort for correcting external and / or internal influences, such as temperature, on the spectroscopic apparatus. [Means for solving the problem]

[0024] This problem is solved by a spectrometer device for obtaining spectroscopic information about at least one object, a method for obtaining spectroscopic information about at least one object, a computer program and a computer-readable storage medium, which have the features of the independent claims. Advantageous embodiments having the features of the independent claims are set out in the dependent claims and throughout the description.

[0025] In a first aspect of the present invention, a spectroscopic device for obtaining spectroscopic information from at least one object is disclosed.

[0026] The term "spectroscopic device" as used herein is a broad term and is intended to have the meaning commonly understood by those skilled in the art, without being limited to a specific or customized meaning. This term may particularly refer to an optical device configured to acquire at least one spectral information from at least one object. Specifically, the at least one spectral information may represent at least one optical or optically measurable characteristic determined as a function of wavelength (one or more different wavelengths). More particularly, the optical or optically measurable characteristic and the at least one spectral information may relate to characteristics characterizing at least one of transmission, absorption, reflection, or emission of the at least one object. These characteristics include when the object is alone or when illuminated with external light. The at least one optical characteristic may be determined for one or more wavelengths. The spectroscopic device may particularly form a device for recording signal intensities at wavelengths corresponding to a spectrum or a portion thereof (e.g., a wavelength range), which may be provided as an electrical signal that can be used for further evaluation.

[0027] The spectroscopic device may be, for example, a device that allows the measurement of at least one spectrum, e.g., for measuring the spectral flux (as a function of wavelength or detection wavelength). The spectrum may be acquired, for example, in absolute units or relative units (relative to at least one reference measurement). For example, the acquisition of at least one spectrum may be performed for measuring the spectral flux (units W / nm) or for measuring a spectrum for at least one reference material (units 1), which describes a material property, e.g., reflectance versus 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 reference signal calculated from literature) and / or a reference device.

[0028] In particular, the at least one spectroscopic device may be a diffuse reflectance spectroscopic device configured to obtain spectral information from light diffusely reflected by at least one object (e.g., at least one sample). Additionally or alternatively, the at least one spectroscopic device may be or include an absorption spectrometer and / or a transmission spectrometer. In particular, measuring the spectrum with the spectroscopic device may include measuring absorption in a transmission configuration. In particular, the spectroscopic device may be configured to measure absorption in a transmission configuration. However, as explained above, other types of spectroscopic devices are also possible.

[0029] The spectroscopic device includes at least one light source, such as a tunable light source, a light source having at least one fixed emission wavelength, or a broadband light source, as described in detail below. The spectroscopic device further includes at least one detector, as described in detail below, configured to detect light transmitted, reflected, or emitted from the at least one object. The spectroscopic device may also include at least one wavelength-selective element, such as a grating, prism, or filter (e.g., a variable-length filter whose transmission characteristics vary in a lateral extension direction), as described in detail below. The wavelength-selective element may be used to separate the incident light into a spectrum of constituent wavelength signals and measure the respective intensities using a detector (e.g., a detector having a detector array), as described in detail below.

[0030] The spectroscopic device may particularly be a portable spectroscopic device. The term "portable" as used herein is a broad term and is intended to have the meaning commonly understood by those skilled in the art, without being limited to any specific or customized meaning. In particular, the term may refer to, but is not limited to, the property of at least one object being movable by human force (e.g., by a single user). Specifically, an object characterized by the term "portable" may include an object having a weight of not more than 10 kg, particularly not more than 5 kg, even more particularly not more than 1 kg, or not more than 500 g. Additionally or alternatively, the dimensions of an object characterized by the term "portable" may be configured to not exceed 0.3 m in any dimension, particularly not more than 0.2 m in any dimension. An object may particularly have a volume of 0.03 m or less. 3 not exceeding, in particular 0.01 m 3 not exceeding, more particularly, 0.001 m 3 Not exceeding 500 mm3 The spectroscopic device may include a portable spectroscopic device having dimensions of, for example, 10 mm x 10 mm x 5 mm. In particular, the portable spectroscopic device may be part of or attachable to a mobile device, such as a laptop, tablet, mobile phone (including a smartphone), smartwatch, or wearable computer (e.g., a body-worn computer such as a wristband or watch). In particular, the weight of the spectroscopic device, in particular the portable spectroscopic device, is in the range of 1 g to 100 g, more particularly in the range of 1 g to 10 g.

[0031] The term "spectroscopic information," also referred to herein as "spectroscopic data" or "spectroscopic data item," is a broad term intended to have a general meaning commonly understood by those skilled in the art and is not limited to any particular or customized meaning. This term may refer, without limitation, to information about at least one object and / or radiation emitted by at least one object, e.g., information characterizing at least one optical property of the object, and more particularly, at least one piece of information characterizing, e.g., qualitatively or quantitatively evaluating, at least one of transmission, absorption, reflection, or emission of the object. For example, the at least one piece of spectral information may include at least one piece of intensity information, e.g., information about the intensity of light transmitted, absorbed, reflected, or emitted by the object, e.g., as a function of one or more wavelengths, e.g., wavelength subranges, e.g., wavelength ranges. Specifically, the intensity information corresponds to or is derived from a signal intensity, particularly an electrical signal, recorded by a spectroscopic device for a spectral wavelength or wavelength range.

[0032] The spectrometer device may be configured to acquire a spectrum, or a portion thereof, of detected light propagating from an object to the spectrometer. The spectrum may describe a radiometric unit of spectral flux, e.g., in watts per nanometer (W / nm), or may be expressed in other units, e.g., as a function of wavelength of the detected light. Thus, the spectrum may describe the optical power of light in a particular wavelength band, e.g., in the near-infrared (NIR) spectral range. The spectrum may include one or more optical variables as a function of wavelength, e.g., a power spectral density, an electrical signal derived from the optical measurement, etc. The spectrum may, e.g., indicate the power spectral density and / or spectral flux of the object (e.g., sample), e.g., the transmittance and / or reflectance of the object (e.g., sample) relative to a reference sample (e.g., transmittance and / or reflectance).

[0033] The spectrum may, for example, include at least one measurable optical variable or property of the detected light and / or the object, in particular as a function that depends on the illuminating light and / or the detected light. For example, the at least one measurable optical variable or property may include at least one radiant quantity, such as spectral density, power spectral density, spectral flux, radiant flux, radiant intensity, spectral radiant intensity, illuminance, spectral irradiance. In particular, for example, the spectroscopic device, in particular the detector, may measure power in watts per square meter (W / m 2 ) の Measures illuminance, more specifically in watts per square meter per nanometer (W / m 2 The spectral irradiance in watts per nanometer (W / nm) can be measured. Based on the measured quantity, and taking into account the area of ​​the detector, the spectral flux in watts per nanometer (W / nm) and / or the radiant flux in watts (W) can be calculated.

[0034] The term "object" as used herein is a broad term and is intended to have a general meaning commonly understood by those skilled in the art, without being limited to any specific or customized meaning. The term "object" is not particularly limited and may refer to any object selected from living and non-living things. For example, at least one object may include one or more articles and / or parts of one or more articles, where at least one article or at least one part thereof may include at least one component that provides a spectrum suitable for investigation. Additionally or alternatively, the object may include one or more living organisms and / or parts thereof, such as a human body part (e.g., a user) and / or an animal. The object may, in particular, include at least one sample that can be fully or partially analyzed by spectroscopy. For example, the object may include any one or more of the following: human skin or animal skin; edible objects such as fruit; plastics and fibers.

[0035] The spectroscopic device includes at least one light source that generates illumination light for illuminating the object.

[0036] The term "light" is used broadly herein and is intended to have the ordinary meaning commonly understood by those skilled in the art, without being limited to any special or customized meaning. The term "light" is specifically, but not exclusively, limited to, and may refer to electromagnetic radiation in any one or more of the infrared, visible, and ultraviolet spectral ranges. As used herein, the "ultraviolet spectral range" generally refers to electromagnetic radiation having wavelengths ranging from 1 nm to 380 nm, preferably from 100 nm to 380 nm. Furthermore, in accordance with, in part, the ISO-21348 standard in effect 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 "infrared spectral range" (IR) generally refers to electromagnetic radiation having wavelengths between 760 nm and 1000 μm, with the range of 760 nm to 1.5 μm commonly referred to as the "near-infrared spectral range" (NIR), the range of 1.5 μm to 15 μm as the "mid-infrared spectral range" (MidIR), and the range of 15 μm to 1000 μm as the "far-infrared spectral range" (FIR). Light used in typical applications of the present invention is preferably light in the infrared (IR) spectral range, more preferably light in the near-infrared (NIR) and / or mid-infrared spectral range (MidIR), particularly light with wavelengths between 1 μm and 5 μm, preferably between 1 μm and 3 μm. This is because many properties related to the physical or chemical makeup of substances can be derived from the near-infrared spectral range. However, it should be noted that spectroscopy in other spectral ranges is also possible and within the scope of the present invention.

[0037] Thus, the term "light source" as used herein is a broad term and is intended to have the general meaning commonly understood by those skilled in the art, without being limited to any specific or customized meaning. In particular, the term may refer to, without limitation, any device that generates or provides light within the above definition. A light source may, in particular, include an electric light source (e.g., an electrically powered light source) or may include at least one electric light source.

[0038] The term "illuminate" is used herein in a broad sense and is used in the sense commonly understood by those skilled in the art, without any specific or customized meaning. This term is particularly, but not exclusively, intended to refer to the process of exposing at least one element to light.

[0039] In spectroscopy, a distinction is made between the source and propagation path of light. In the context of the present invention, first, light propagating from a light source to an object is referred to as "illumination light" or "illumination light ray." Second, light propagating from an object to a detector is referred to as "detected light." Detected light can include illumination light reflected by the object, illumination light scattered by the object, illumination light transmitted by the object, and luminescence light generated by the object (e.g., fluorescence or phosphorescence generated by the object after optical, electrical, or acoustic stimulation by the illumination light). Thus, detected light may be generated directly or indirectly through illumination of the object by the illumination light.

[0040] Furthermore, as will be explained in more detail below, it is also possible to distinguish between different light sources within the light source itself, such as primary and secondary light sources. Thus, as will be explained in more detail below, "primary light" (also referred to as "pump light") may be generated by a primary light source, such as at least one light-emitting diode, and then converted to "secondary light" by photoconversion (e.g., through one or more phosphor materials). Illumination light may be or include primary light or a portion thereof, secondary light or a portion thereof, or a mixture of both.

[0041] The light sources can generally be realized in a variety of forms. For example, the light sources may be part of the spectroscopic device and located within the housing of the spectroscopic device. However, at least one light source may be located outside the housing, for example as a stand-alone light source. The light sources may also be located remotely from the object and configured to illuminate the object.

[0042] The light source may in particular also be configured to emit light in a spectral range comprising part or all of the infrared spectral range, in particular the near-infrared spectral range, more particularly in the spectral range from 760 nm to 3 μm, more particularly in the spectral range from 1 μm to 3 μm, preferably in the spectral range from 1.3 μm to 2.5 μm, more preferably in the spectral range from 1.5 μm to 2.2 μm.

[0043] The light source may comprise at least one light source selected from the following group: incandescent lamps; light-emitting diodes (LEDs); lasers, in particular laser diodes, solid-state lasers, gas lasers, quantum cascade lasers; plasma light sources; low-pressure discharge lamps, in particular low-pressure fluorescent lamps; high-pressure discharge lamps; electric light sources. Low-pressure discharge lamps refer to gas discharge lamps which operate under normal conditions with a gas pressure below 1% of atmospheric pressure. High-pressure discharge lamps refer to gas discharge lamps which, under normal conditions, have a gas pressure above 10% of atmospheric pressure. Electric light sources refer to any type of light source which can be driven by an electric current and voltage.

[0044] The light source may include at least one light emitting diode and one luminescent material that photoconverts primary light generated by the light emitting diode. Specifically, the illumination light can be a combination of the primary light generated by the light emitting diode and light generated by photoconversion by the luminescent material (also called secondary light).

[0045] The term "light-emitting diode" or abbreviation "LED" is used broadly herein and is intended to have the ordinary meaning commonly understood by those skilled in the art, without being limited to any special or customized meaning. This term may particularly, but not exclusively, refer to an optoelectronic semiconductor device that emits light when an electrical current passes through the device. The optoelectronic semiconductor device may be configured to generate light by one or more physical processes, such as spontaneous emission, induced emission, or decay of a metastable excited state. Thus, for example, a light-emitting diode may include one or more of the following: a light-emitting diode based on spontaneous emission (particularly an organic light-emitting diode), a light-emitting diode based on superluminescence (sLED), or a laser diode (LD). Hereinafter, the abbreviation "LED" is used for any type of light-emitting diode, without limiting possible embodiments of the light-emitting diode to any of the aforementioned physical principles or configurations. Specifically, an LED may include at least two layers of semiconductor material and be configured to generate light at the interface of the at least two layers of semiconductor material, particularly by recombination of positive and negative electrical charges, e.g., electron-hole recombination. The at least two layers of semiconductor material may have different electrical properties, for example, at least one layer may be an n-type doped semiconductor material and at least one layer may be a p-type doped semiconductor material. Thus, for example, the LED may include at least one p-n junction and / or at least one p-i-n structure. However, other device structures are also possible. The at least one semiconductor material may in particular be or include at least one inorganic semiconductor material. However, organic semiconductor materials may also be used additionally or alternatively.

[0046] In general, an LED may convert electrical current into light, specifically into primary light, more specifically into blue primary light, as described in more detail below. Thus, the LED may specifically be a blue LED. The LED may be configured to generate primary light (also referred to as pump light). Thus, the LED may also be referred to as a "pump LED." The LED may include at least one LED chip and / or at least one LED die. Thus, the semiconductor element of the LED may include a bare LED chip.

[0047] Various LEDs suitable for generating primary light are well known to those skilled in the art and are applicable to the present invention. In particular, pn diodes may be used. For example, one or more LEDs selected from indium gallium nitride (InGaN)-based LEDs, GaN-based LEDs, LEDs based on InGaN / GaN alloys or combinations thereof, or other LEDs may be used. Additionally or alternatively, quantum well LEDs may be used, for example, one or more quantum well LEDs based on InGaN. Additionally or alternatively, superluminescent LEDs (sLEDs) and / or quantum cascade lasers may be used.

[0048] The term "luminescence" as used herein is a broad term and is intended to have the general meaning commonly understood by those skilled in the art, without being limited to a specific or customized meaning. Specifically, it includes, but is not limited to, the spontaneous emission of light from a substance without thermal origin. In particular, luminescence may refer to "cold body radiation." More specifically, luminescence can be induced or excited by light irradiation, in which case luminescence is also referred to as "photoluminescence." In the context of the present invention, the ability of a substance to emit light is expressed by the adjective "luminescent." At least one luminescent material may specifically be a photoluminescent material, i.e., a material capable of emitting light after absorbing photons or excitation light. Specifically, the luminescent material may have a positive Stokes shift, which generally indicates that the secondary light is red-shifted relative to the primary light.

[0049] Thus, the at least one luminescent material may form at least one converter (also called an optical converter) that converts primary light into secondary light having spectral characteristics different from those of the primary light. In particular, the spectral width of the secondary light may be wider than that of the primary light, and / or the central wavelength of the secondary light may be shifted (particularly red-shifted) relative to the primary light. In particular, the at least one luminescent material may absorb in the ultraviolet and / or blue spectral region and emit in the near-infrared and / or infrared spectral region. Thus, in general, the luminescent material or converter may form at least one component of a phosphor LED that converts primary or pump light (particularly in the blue spectral region) into light of a longer wavelength (e.g., in the near-infrared or infrared spectral region).

[0050] Various types of conversion and / or emission are known and may be used in the context of the present invention. Thus, in particular, conversion may occur via a dipole-allowed transition (fluorescence) in the luminescent material, or via a dipole-forbidden (and therefore long-lived) transition in the luminescent material, the latter also commonly referred to as fluorescence.

[0051] The luminescent material may thus form at least one converter or light converter. The luminescent material may form at least one converter plate, as a phosphor and phosphor coating on an LED, or as a phosphor coating on an LED. The luminescent material may, for example, comprise one or more of the following materials: cerium-doped YAG (YAG:Ce3+, or Y3Al5O12:Ce3+); rare-earth-doped sialon; copper- and aluminum-doped zinc sulfide (ZnS:Cu,Al).

[0052] The LED and luminescent material may form a so-called "phosphor LED." Therefore, the term "phosphor light-emitting diode" or abbreviated "phosphor LED" as used herein is a broad term and is intended to have the meaning commonly understood by those skilled in the art and is not limited to any specific or customized meaning. This term may specifically, but is not limited to, a combination of at least one light-emitting diode (LED) and at least one luminescent material (phosphor) for photoconverting the primary or pump light generated by the LED. A phosphor LED may form a packaged LED light source that includes an LED die (e.g., a blue LED emitting blue pump light) and a phosphor (e.g., configured to fully or partially cover the LED and convert the primary or blue light to light with different spectral characteristics, particularly near-infrared light). Generally, phosphor LEDs may be encapsulated in a single housing or may be unencapsulated. Therefore, the LED and at least one phosphor for photoconverting the primary light generated by the LED may be housed in a common housing. Alternatively, the LED may be an unpackaged or bare LED and may be fully or partially coated with luminescent material, for example, by disposing one or more layers of luminescent material on the LED die. Phosphor LEDs generally form the light emitting element or light source by themselves.

[0053] In a light source, particularly a phosphor LED, at least one luminescent material may be disposed in a position that allows heat transfer from the light emitting diode to the luminescent material. More specifically, the luminescent material may be disposed to allow heat transfer by thermal radiation and / or thermal conduction, more preferably by thermal conduction. For example, the luminescent material may be disposed in thermal and / or physical contact with the light emitting diode. For example, the luminescent material may form one or more coatings or layers in contact with or adjacent to the light emitting diode, and in contact with one or more of the semiconductor materials of the light emitting diode. This generally allows the temperature of the luminescent material to be coupled to the temperature of the light emitting diode.

[0054] The at least one luminescent material may form at least one layer. Generally, various alternatives for disposing the luminescent material relative to the light-emitting diode are possible, alone or in combination. First, the luminescent material (e.g., at least one layer of luminescent material, e.g., phosphor) may be disposed directly on the light-emitting diode, also referred to as "direct attachment." This may be the case, for example, when there is no material between the LED and the luminescent material, or when one or more transparent materials (e.g., one or more transparent materials transparent to the primary light) are disposed between the LED and the luminescent material. For example, a coating of luminescent material may be disposed directly or indirectly on the LED. Additionally or alternatively, the luminescent material may form, for example, at least one converter body (e.g., at least one converter disk), which may be disposed on the LED, for example, by adhesively fixing the converter body to the LED. Additionally or alternatively, the luminescent material may be disposed remotely, such that the primary light from the LED must pass through an intermediate optical path before reaching the luminescent material. This arrangement may also be referred to as "remote attachment" or "remote phosphor." For example, the luminescent material in the remote location can form a solid body or converter body, such as a disk or converter disk. Furthermore, in the remote location, the luminescent material can also function as a coating. In particular, a phosphor can be coated on a light-transmitting object (e.g., a thin plate made of or fabricated from glass or plastic, such as a glass substrate or a module window). Alternatively, a reflective surface can be coated with the phosphor. This can be a flat or rough mirror made of or fabricated from a substrate of a highly reflective material, such as silicon, or a flat or rough surface, such as glass or plastic, coated with gold, silver, aluminum, or chromium. One or more optical elements, including lenses, prisms, gratings, mirrors, apertures, or combinations thereof, can also be disposed in the intermediate optical path. Specifically, an optical system with imaging properties can be disposed in the intermediate optical path between the LED and the luminescent material. This can, for example, focus or bundle the primary light into the converter body.

[0055] The spectroscopic device further comprises at least one detector that detects the detected light from the object and generates at least one detector signal.

[0056] The verb "detect" is used herein as a broad term and is intended to have the ordinary meaning commonly understood by those skilled in the art, without being limited to any special or customized meaning. This term may particularly, without limitation, refer to the process of qualitatively and / or quantitatively measuring, measuring, or monitoring at least one parameter (e.g., a physical parameter, a chemical parameter, a biological parameter, etc.). Specifically, the physical parameter may be or may include an electrical parameter. Accordingly, the term "detector" as used herein is a broad term and is given its ordinary and customary meaning to those of ordinary skill in the art, without being limited to any special or customized meaning. Specifically, this term may refer to any device for qualitatively and / or quantitatively measuring, measuring, or monitoring at least one parameter (e.g., a physical parameter, a chemical parameter, or a biological parameter). The detector may also be configured to generate at least one detector signal, more particularly at least one electrical detector signal (including analog and / or digital detector signals), which may provide information about the at least one parameter measured by the detector. The detector signal may include at least one detected current indicative of accumulated photocurrent from the detector, particularly at least one detected current from each pixel of the detector. The detector signal may be provided directly or indirectly from the detector to an evaluation unit, and the detector and evaluation unit may be directly or indirectly connected. The detector signal may be used as a "raw" detector signal, or may be processed or pre-processed before further use, for example by filtering. Accordingly, the detector may also include at least one processing unit and / or at least one pre-processing unit, such as at least one of an amplifier, an analog-to-digital converter, an electrical filter, or a Fourier transform.

[0057] In this embodiment, the detector is configured to detect light propagating from the object to the spectroscopic device or, more particularly, to the detector of the spectroscopic device; according to the terminology described above, this light is referred to as "detected light." Therefore, in particular, the detector may be or may include at least one optical detector. The optical detector may be configured to measure at least one optical parameter, such as the intensity and / or power of light irradiating at least one light-sensitive area of ​​the detector. More particularly, the optical detector may include at least one light-sensitive element and / or at least one optical sensor, such as at least one of a photodiode, a photocell, a photosensitive resistor, a phototransistor, a thermosensitive sensor, a photoacoustic sensor, a pyroelectric sensor, a photomultiplier, or a bolometer. The detector may therefore be configured to generate at least one detector signal, more particularly at least one electrical detector signal, in the above sense, providing information about at least one optical parameter, such as the power and / or intensity of light irradiating the detector or the light-sensitive area of ​​the detector.

[0058] The detector may comprise a single light-sensitive element or region, or a plurality of light-sensitive elements or regions (hereinafter also referred to as "light-sensitive elements"). In particular, the detector may be or comprise components of at least one detector array, more particularly an array of light-sensitive elements, as will be explained in more detail below. Each light-sensitive element may comprise at least one light-sensitive region adapted to generate an electrical signal depending on the intensity of the incident light, which electrical signal is provided to, in particular, an evaluation unit, which will be explained in more detail below.

[0059] The light sensitive area contained in each light sensitive element may be a single uniform light sensitive area specifically configured to receive incident light that illuminates the individual light sensitive element, although other arrangements of light sensitive elements are also contemplated.

[0060] The array of light-sensitive elements may be designed to generate a detector signal (preferably an electronic signal) corresponding to the intensity of incident light impinging on each individual light-sensitive element. The detector signal may be an analog signal and / or a digital signal. The electronic signals of adjacent pixelated sensors can thus be generated simultaneously or sequentially in time. For example, during a row or line scan, it is possible to generate a sequence of electronic signals corresponding to a series of linearly arranged individual light-sensitive elements. Furthermore, the individual light-sensitive elements are preferably active pixel sensors, which can be adapted to amplify the electronic signals before supplying them to the evaluation unit. For this purpose, the detector may also include one or more signal processing devices (e.g., one or more filters and / or analog-to-digital converters) for processing and / or preprocessing the electronic signals.

[0061] If the detector includes an array of light-sensitive elements, the detector may be selected, for example, from known pixel sensors, particularly pixelated organic camera elements, preferably pixelated organic camera chips, or pixelated inorganic camera elements, preferably pixelated inorganic camera chips, more preferably CCD or CMOS chips, which are currently commonly used in various cameras. Alternatively, the detector may generally be or include a photoconductor, particularly an inorganic photoconductor, in particular PbS, PbSe, Ge, InGaAs, InGaAs, InSb, or HgCdTe. As a further alternative, it may include at least one element comprising a pyroelectric, bolometric, or thermophilic detector element. Thus, camera chips with a matrix of 1×N pixels or M×N pixels may also be used, where, for example, M is less than 10 and N may be in the range of 1 to 50, preferably 2 to 20, and more preferably 5 to 10. Furthermore, monochrome camera elements, preferably monochrome camera chips, can be used, which can be different for each optically sensitive element depending on the wavelength that varies along the optical sensor sequence. The array is therefore adaptable to provide a plurality of electrical signals generated by the light sensitive regions of the light sensitive elements that make up the array. The electrical signals provided by the array of spectroscopic devices may be transmitted to an evaluation unit.

[0062] The spectroscopic device further includes at least one driving unit for electrically driving the light source.

[0063] The term "drive" as used herein is a broad term and is intended to have the meaning commonly understood by those skilled in the art, without being limited to a specific or customized meaning. In particular, this term may refer to, but is not limited to, the process of providing at least one control parameter and / or electrical power to another device. Accordingly, the term "drive unit" as used herein is a broad term and is intended to have the meaning commonly understood by those skilled in the art, without being limited to a specific or customized meaning. In particular, this term may refer to, but is not limited to, any device or combination of devices that provides at least one control parameter and / or electrical power to another device (e.g., in this embodiment, to at least one light source). The drive unit may be configured to, in particular, control one or more electrical parameters of the electrical power provided to the light source. In particular, the drive unit may be configured to control parameters of the electrical power provided to at least one light-emitting diode. For example, the drive unit may be configured to supply an electrical current to an LED, in particular to control the electrical current through the LED. In that case, for example, the driving unit may be configured to adjust the voltage supplied to the LED, which voltage is required to achieve a specific electrical current through the LED. The driving unit may also include one or more of a current source and a voltage source. In particular, the driving unit may include at least one current source for supplying at least one predetermined current to the LED, where the current source may be configured to adjust or control the voltage applied to the LED to generate the predetermined current. The driving unit may include one or more electrical components, such as, for example, an integrated circuit for driving the light source. The driving unit may be fully or partially integrated into the light source, or may be separate from the light source.

[0064] The spectrometer device includes at least one multi-channel readout integrated circuit. Each channel of the multi-channel readout integrated circuit includes at least one buffered direct injection (BDI) circuit. The BDI circuit is configured for readout of a detector signal. The BDI circuit is configured to generate at least one electrically measurable quantity necessary to drive a light source. The multi-channel readout integrated circuit includes at least one multi-channel read-only integrated circuit (ASIC) configured to synchronously sample the detector signal and the electrically measurable quantity necessary to drive the light source.

[0065] The term "readout", also referred to herein as "reading", is a broad term and is intended to have the general meaning commonly understood by those skilled in the art, without being limited to any specific or customized meaning. In particular, but without being limited to, the term may refer to the act or process of quantifying and / or processing at least one physical property and / or a change in at least one physical property by at least one device, particularly at least one component of a spectroscopic device.

[0066] The term "integrated circuit" (IC) is a broad term used herein and is intended to have a general meaning commonly understood by those skilled in the art, without being limited to a specific or customized meaning. In particular, the term may refer to, but is not limited to, a set of electronic circuits on a chip. The chip may include at least one substrate made of a semiconductor material, and may be formed on at least one substrate made of silicon. The term "readout integrated circuit" (ROIC) is a broad term used herein and is intended to have a general meaning commonly understood by those skilled in the art, without being limited to a specific or customized meaning. In particular, the term may refer to, but is not limited to, an integrated circuit configured to read at least one component of a spectroscopic device. For example, the ROIC may be configured to read a detector, where reading the detector may include accumulating photocurrent from each pixel of the detector to generate a detector signal and transmitting the detector signal to at least one output for further evaluation. Furthermore, the ROIC is configured to generate electrically measurable quantities of information necessary to drive a light source. The ROIC may include at least one channel for reading at least one channel of the detector (specifically, at least one channel corresponding to each pixel of the detector) and at least one channel for generating information about the electrically measurable quantity required to drive the light source, as described in more detail below.

[0067] The readout integrated circuit may in particular be an analog integrated circuit, i.e. comprising a set of electrical circuits including active elements such as transistors and passive elements such as capacitors, resistors and / or inductors, which is an integrated circuit configured for processing continuous signals, in particular continuous analog signals.

[0068] A multi-channel readout integrated circuit can include at least two channels, for example, at least one channel for reading out a detector signal and at least one channel for generating an electrically measurable quantity of information required to drive a light source. Therefore, a readout integrated circuit including at least two channels is also referred to as a multi-channel readout integrated circuit. The term "channel" is used herein in a broad sense and is intended to have a general meaning commonly understood by those skilled in the art, without being limited to a specific or customized meaning. In particular, the term may refer, without limitation, to an electrical circuit or set of electrical circuits associated with at least one component of a spectroscopic device. Specifically, a multi-channel readout integrated circuit can include at least one channel associated with a detector, which channel is specifically configured for reading out a detector signal generated by the detector. Additionally, a multi-channel readout integrated circuit can include at least one additional channel associated with another component, such as a resistor, as described below, which channel is specifically configured for generating an electrically measurable quantity of information required to drive a light source. As described above, a detector can include multiple light-sensitive elements. In this case, the multi-channel readout integrated circuit may include at least one channel associated with each light sensitive element, said channel being specifically configured for readout of the detector signal of the associated light sensitive element.

[0069] Each channel includes at least one BDI circuit, as described above. The term "buffered direct injection circuit" (BDI circuit) is used herein in a broad sense and is intended to have the meaning commonly understood by those skilled in the art, without any specific or customized meaning. In particular, the term may refer to, but is not limited to, an electronic device comprising at least one electrical circuit and providing a buffering function. Specifically, a BDI circuit may include a single electrical circuit or a set of electrical circuits, where at least one electrical circuit may comprise at least one feedback circuit, particularly at least one feedback circuit configured to reduce the input impedance of the BDI circuit's input signal. For this purpose, the BDI circuit may include at least one buffer amplifier (e.g., at least one voltage buffer and / or at least one current buffer). The BDI circuit may be implemented as an ASIC with multiple channels for generating electrically measurable quantities of information necessary for detector readout and for driving multiple parallel light sources.

[0070] As used herein, the term "electrically measurable quantity" is a broad term and is intended to have the meaning commonly understood by those skilled in the art, without being limited to any specific or customized meaning. In particular, the term may refer, without limitation, to an electrically measurable parameter required to drive a light source. Thus, an "item of information related to an electrically measurable quantity" may refer to a numerical representation that quantifies the electrically measurable quantity. For example, the information related to the electrically measurable quantity required to drive a light source may include at least one piece of information selected from the following group: forward voltage at the light source; voltage drop at the light source; current at the light source; electrical input power to the light source; resistance of the light source; and impedance of the light source.

[0071] The term "application-specific integrated circuit (ASIC)" is used herein in a broad sense and is intended to have the meaning commonly understood by those skilled in the art, without being limited to a specific or customized meaning. In particular, the term is not limited and may refer to an integrated circuit configured for a specific application. Specifically, in the context of the present invention, an ASIC is configured to perform synchronous sampling of detector signals and information about electrically measurable quantities necessary to drive a light source. Thus, a specific application of the ASIC may be synchronous sampling of detector signals and information about electrically measurable quantities necessary to drive a light source.

[0072] The term "sampling" is used broadly herein and is intended to have the general meaning commonly understood by those skilled in the art, without being limited to any particular or customized meaning. Specifically, the term may refer to the process of obtaining measurements from a continuous-time signal. Specifically, sampling may include the process of obtaining measurements, such as an electrically measurable detector signal and / or an item of information required to drive a light source, from the continuous-time signal provided to a BDI circuit (especially an ASIC). The continuous-time signal may also include an electrical signal from a detector (e.g., a photocurrent and / or a photovoltage that varies depending on the intensity of light irradiating the detector) and / or an electrically measurable electrical signal required to drive a light source. The term "synchronization" as used herein is a broad term and is intended to have the general meaning commonly understood by those skilled in the art and is not limited to any particular or customized meaning. In particular, the term may refer to, but is not limited to, the property of two or more processes being executed in an at least partially overlapping manner. Specifically, the synchronous execution of two or more processes may include starting and completing the two or more processes simultaneously, or starting at least one process before at least one other process, and further, starting at least one other process before the completion of the previously started process. Synchronous sampling of the detector signal and information about the electrically measurable quantity required to drive the light source may include reading out the detector signal and generating information about the electrically measurable quantity required to drive the light source in an at least partially overlapping manner, particularly simultaneously. For example, synchronous sampling of the detector signal and information about the electrically measurable quantity required to drive the light source may include reading out the detector signal and generating information about the electrically measurable quantity required to drive the light source in parallel.

[0073] A multi-channel read-only integrated circuit (ASIC) may also include at least one skimming circuit for current skimming of the current in the detector. The term "skimming circuit" is used herein in a broad sense and has the meaning commonly understood by those skilled in the art, without being limited to any specific or customized meaning. In particular, the term may refer to, but is not limited to, an electrical circuit configured for current skimming to remove a portion of the current in another electrical circuit. Specifically, the skimming circuit may be configured to skim the current in the detector, i.e., the detector current. As described above, the detector signal may include a detector current indicative of the accumulated photocurrent from the detector. Thus, the skimming circuit may function as a current sink, particularly a current sink for the detector current. The skimming circuit may be included in at least one channel of a multi-channel read-only integrated circuit (especially a multi-channel read-only integrated circuit (ASIC)) configured for reading out the detector signal. The skimming circuit may be optional. For example, if the light source is an LED, the skimming circuit may not be required. In this case, the input voltage to the BDI circuit is within the positive voltage range of the LED, so skimming may not be required. However, for other light sources, for example when the BDI input voltage is lower than the voltage applied to the light source (e.g., 0 V), a skimming circuit located in the ASIC can be advantageously used to remove the DC component of the voltage applied to the light source. The skimming circuit may particularly include at least one programmable current sink (comprising one or more transistors, particularly multiple transistors). These transistors may be of the same size and, when connected in parallel, may function as equal-weight transistors when programmed, or alternatively, transistors of twice the size may be connected in series and, when programmed, may function as binary-weight transistors.

[0074] A typical channel of a multi-channel readout integrated circuit includes a BDI circuit and can be configured for readout of the detector signal. The input of the BDI circuit can be connected to the output of the detector, specifically the output of a pixel of the detector. The BDI circuit is connected to a bias voltage VBias By applying a voltage to the detector, the voltage applied to the detector can be kept constant. The multi-channel readout integrated circuit can further include an analog-to-digital converter (ADC). A change in the resistance of the detector due to illumination can result in an increase in current flow, which can be digitized by the analog-to-digital converter. Optionally, the ROIC (especially the multi-channel readout-only integrated circuit) can include at least one skimming circuit for skimming the current in the detector, which is particularly useful for removing signal offsets, especially when the light source is a light source other than an LED.

[0075] Additionally or alternatively, an exemplary channel of the multi-channel readout integrated circuit may include a BDI circuit and be configured to generate an electrically measurable quantity of information necessary to drive the light source. For example, the light source may include an LED. The spectroscopic device may further include at least one resistor electrically connecting the anode of the LED and the ROIC. For example, the resistor may have a resistance value in the range of 1 MΩ to 10 MΩ, and specifically R=2 MΩ. The spectroscopic device may also include a shunt resistor. In this example, the spectroscopic device may include at least two resistors, and these two or more resistors may have similar or different configurations. Each end of the shunt resistor may be electrically connected to the multi-channel readout integrated circuit via one of the resistors. This allows the voltage drop across the shunt resistor and the current through the light source to be measured. An example of a shunt resistor is one with a resistance value in the range of 1 MΩ to 10 MΩ, and specifically R=1 Ω.

[0076] The spectroscopic device comprises at least one evaluation unit for evaluating at least one detector signal generated by the detector and for deriving spectroscopic information of the object from the detector signal, the evaluation unit being configured to take into account information of electrically measurable quantities necessary for driving the light source when deriving the spectroscopic information from the detector signal.

[0077] The term "evaluate" as used herein is a broad term and is intended to have the ordinary meaning commonly understood by those skilled in the art, without being limited to a specific or customized meaning. In particular, this term may refer to, but is not limited to, a process of processing at least one first item of information to generate at least one second item of information. Accordingly, the term "evaluation unit" as used herein is a broad term and is intended to have the ordinary meaning commonly understood by those skilled in the art, without being limited to a specific or customized meaning. This term "evaluation unit" may refer to, but is not limited to, any device or combination of devices configured to evaluate or process at least one first item of information to thereby generate at least one second item of information. Accordingly, the evaluation unit may be configured to process at least one input signal and thereby generate at least one output signal. The at least one input signal may, for example, include at least one detector signal provided directly or indirectly from at least one detector, and may further include at least one signal provided directly or indirectly from a multi-channel readout integrated circuit, the signal specifically including at least one item of information related to at least one electrically measurable quantity.

[0078] For example, the evaluation unit may be or include one or more integrated circuits (e.g., one or more application-specific integrated circuits (ASICs)) and / or one or more data processing devices (e.g., one or more computers, digital signal processors (DSPs), field programmable gate arrays (FPGAs), preferably one or more microcomputers and / or microcontrollers). Additional components may also be included, such as one or more pre-processing and / or data acquisition devices (e.g., one or more devices for receiving and / or pre-processing the detector signals, such as one or more analog-to-digital converters (AD converters) and / or one or more filters). Furthermore, the evaluation unit may also 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.

[0079] The evaluation unit may be adapted to execute at least one computer program, which, for example, performs or assists in the generation of an information item. For example, at least one algorithm may be implemented, which uses at least one detector signal and at least one piece of information related to at least one electrically measurable quantity as input variables to perform a predetermined transformation for deriving spectroscopic information of the object (e.g., for deriving a corrected spectrum and / or for deriving at least one piece of spectroscopic information describing at least one property of the object). For this purpose, the evaluation unit may in particular include at least one data processing device (also referred to as processor), in particular an electronic data processing device, designed to evaluate the information items related to the detector signal and the at least one electrically measurable quantity to generate the desired information. The evaluation unit may use any processing to generate the required information, for example, calculations and / or at least one stored and / or known relationship. The evaluation unit may be configured to perform at least one digital signal processing (DSP) technique, in particular at least one Fourier transform, on the primary detector signal or the secondary detector signal derived therefrom. Additionally or alternatively, the evaluation unit may be configured to perform one or more additional digital signal processing techniques, including, for example, windowing, filtering, a Goldsel algorithm, cross-correlation, or autocorrelation, on the primary detector signal or the secondary detector signal derived therefrom. In addition to information about the detector signal and the at least one electrically measurable quantity, one or more additional parameters and / or information may influence the relationship. The relationship may be determined or determinable empirically, analytically, or semi-empirically. For example, the relationship may comprise a model or calibration curve, a set of at least one calibration curve, at least one function, or a combination of the above possibilities. The one or more calibration curves may be stored in a data storage device and / or a table, for example in the form of a set of values ​​and their corresponding function values.However, alternatively or additionally, the at least one calibration curve can also be stored in parameterized form and / or as a function. Separate relations for converting the detector signals into information items can also be used. Alternatively, at least one unified relation for processing the detector signals can be employed. Various possibilities are conceivable, which can also be combined.

[0080] The evaluation unit can also be configured, for example, by software programming, to determine at least one correction value from information about at least one electrically measurable quantity. Thus, for example, the evaluation unit can be configured to determine a spectrum from at least one detector signal provided by the detector, the spectrum including a luminous intensity or radiance parameter as a function of wavelength. The spectrum is corrected by applying at least one correction function (e.g., a correction factor, e.g., a wavelength-dependent correction function) to the spectrum, thereby generating a corrected spectrum. Thus, for example, the correction factor can be or include at least one correction factor that depends on the color temperature of the detected light and the at least one electrically measurable quantity. The detector signal, for example, provides a signal that is a function of the wavelength of the detected light, and the correction factor can be used to multiply each function value of the detector signal by a corresponding correction factor determined by the at least one electrically measurable quantity.

[0081] For example, the detector signal may include multiple detector signals that are at least a function of the wavelength of the detected light, and may also include a time-dependent detector signal that is also dependent on time, if desired. These multiple detector signals may form a digital or analog spectrum. Thus, for example, each detector signal may summarize information from a given spectral range defined by the detector's spectral resolution. As noted above, a detector may include multiple light-sensitive elements, each sensitive to a different spectral range, or may include light-sensitive elements exposed to different portions of the detected light spectrum. The detector signals of the light-sensitive elements may form the detector signal, or may collectively define, for example, spectral information, a portion thereof, or a precursor thereof. Because the spectral range of sensitivity of each light-sensitive element is known, the detector signals may allow the detection of the intensity of the detected light for a detected wavelength, which may be derived by combining data pairs including the signal of each light-sensitive element and the wavelength of sensitivity. The signal of each light-sensitive element may be corrected using a correction factor for the corresponding wavelength. The correction factor is provided by the evaluation unit as a function of at least one electrically measurable quantity, in particular the forward voltage. However, other methods of generating spectral information are possible, such as sequentially exposing the same detector to different spectral regions of the detected light (e.g., using a scannable wavelength-selective element). Correction of these sequentially measured spectra can be performed in a similar manner using a correction factor as a function of wavelength to appropriately correct the spectra.

[0082] The spectroscopic device may further include at least one resistor electrically connecting the light source and a multi-channel readout integrated circuit (ROIC). Specifically, if the light source is an LED, the resistor may electrically connect the anode of the LED and the ROIC. The spectroscopic device may further include at least two resistors and at least one shunt resistor. Each end of the shunt resistor (bypass resistor) may be electrically connected to the multi-channel readout integrated circuit via at least one resistor. This allows the voltage drop across the shunt resistor to be measured, thereby enabling the current through the light source to be measured. The resistor and / or shunt resistor may have a temperature coefficient of less than 1000 ppm / K, specifically less than 100 ppm / K, more specifically less than 50 ppm / K, and even more specifically less than 10 ppm / K.

[0083] As described above, the detector may include a plurality of light-sensitive elements, particularly an array of light-sensitive elements, each configured to generate at least one detector signal. The evaluation unit may be configured to consider information on electrical measurements required to drive the light source corresponding to the detector signal of each light-sensitive element individually and to derive spectroscopic information by combining the detector signals. Specifically, the spectroscopic device may be configured such that the light-sensitive elements are sensitive to different spectral ranges of light from the object. For example, the spectroscopic device may include at least one wavelength-selective element arranged in the detection light path. The wavelength-selective element may be configured such that each light-sensitive element is exposed to a respective spectral range of the detected light from the object.

[0084] Additionally or alternatively, the detector may include a single detector, and the light source may include multiple light sources having different spectral ranges. Each light source may be configured to generate illumination light for illuminating the object in a specific spectral range. The detector may be configured to detect detected light from the object (particularly, illumination light reflected from multiple light sources in different spectral ranges) and may be configured to generate at least one time-dependent detector signal. The evaluation unit may be configured to evaluate the time-dependent detector signals by frequency multiplexing, particularly to derive at least one detector signal corresponding to each different spectral range from the time-dependent detector signals. The detector signals for each different spectral range may be used to derive spectroscopic information about the object. Specifically, the evaluation unit may be configured to derive the spectroscopic information by combining the detector signals, taking into account separately information on electrically measurable quantities necessary to drive the light sources corresponding to each detector signal. Additionally or alternatively, multiple light-sensitive elements and multiple light sources may be used in combination, as described above. A multi-channel readout circuit allows in each case synchronous sampling of the detector signal and the electrically measurable quantities of information required to drive the light source.

[0085] The spectrometer device may also include at least one wavelength-selective element. The wavelength-selective element may include at least one of a wavelength-selective element disposed in the optical path of the illumination light and a wavelength-selective element disposed in the optical path of the detection light. The wavelength-selective element may be selected from the group of tunable wavelength-selective elements or wavelength-selective elements having a fixed transmission spectrum. The wavelength-selective element having a fixed transmission spectrum may include at least one filter element, particularly at least one absorption filter element, more particularly a bandpass filter element. The tunable wavelength-selective element may include at least one tunable interferometer, particularly at least one of a MEMS Fabry-Perot interferometer or a MEMS Michelson interferometer.

[0086] In yet another aspect of the present invention, a method for obtaining spectroscopic information of at least one object using a spectroscopic device is disclosed. For specific embodiments of the spectroscopic device and definitions of terms, reference is made to the description of the spectroscopic device above.

[0087] The method may perform the following steps in a given order, although different orders are also possible. In particular, one, several, 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 a time-overlapping, parallel, or combined manner. The method may also include additional method steps not listed.

[0088] The method includes the following steps: a. electrically driving at least one light source using at least one driving unit; b. illuminating the object with illumination light generated by the light source; c. detecting the detection light from the object using at least one detector and generating at least one detector signal; d. generating at least one information related to an electrically measurable quantity required to drive the light source using at least one multi-channel readout integrated circuit, each channel of the multi-channel readout integrated circuit including at least one buffered direct injection (BDI) circuit, wherein the BDI circuit is configured for readout of the detector signal, the BDI circuit being configured to generate the at least one information related to the electrically measurable quantity required to drive the light source, wherein the multi-channel readout integrated circuit (ASIC) includes at least one multi-channel readout application-specific integrated circuit (ASIC) configured to synchronously sample the detector signal and the at least one information related to the electrically measurable quantity required to drive the light source; e. Evaluating at least one detector signal generated by the detector using at least one evaluation unit and deriving spectroscopic information of the object from the detector signal taking into account information about electrically measurable quantities necessary to drive the light source.

[0089] In particular, the method may use a spectroscopic device of the present invention according to any of the embodiments described above or disclosed in detail below.

[0090] Steps c. and d. may be performed with suitable timing overlap, in particular in parallel.

[0091] The method can be performed online in situ. As used herein, the term "online" is a broad term and is intended to have the ordinary meaning commonly understood by those skilled in the art, without being limited to any special or customized meaning. This term may particularly refer to, but is not limited to, the nature of a process being performed as part of another process, including, for example, a process that is performed during another process and does not need to be separately initiated or activated by a user. Thus, specifically, the correction of the detector signal can be performed as an online calibration or correction when acquiring spectroscopic information of at least one target object using information of at least one electrically measurable quantity, without the need to perform a separate calibration process.

[0092] Furthermore, in step e, at least one correction can be determined from at least one information related to the electrically measurable quantity required to drive the light source, and wherein further, at least one detector signal can be corrected using said correction. The correction can in particular include at least one temperature correction. The temperature correction can depend at least in part on the information related to the electrically measurable quantity required to drive the light source. The correction can include multiplying the at least one detector signal by at least one correction factor. The corrected detector signal can be used to derive spectroscopic information.

[0093] The term "correction" as used herein is a broad term and is intended to have the meaning commonly understood by those skilled in the art and is not limited to a specific or customized meaning. This term particularly includes, but is not limited to, the process of modifying or altering at least one feature of interest according to one or more pieces of information indicative of parameters known to affect the feature of interest. Accordingly, the measured spectrum may be corrected so that the corrected spectrum corresponds to a spectrum under precisely known or standardized conditions, e.g., a specific temperature and / or predetermined electrically measurable quantity. As an example, the correction may include modifying the measured spectrum contained in the detector signal to correspond to standardized conditions under a predetermined electrically measurable quantity and / or a predetermined temperature required to drive the light source. Accordingly, step e. may include modifying the measured spectrum derived from the detector signal to correspond to a corrected spectrum (particularly, a corrected spectrum estimated to be obtained under predetermined standard conditions), e.g., a spectrum under a predetermined electrically measurable quantity and / or a predetermined temperature required to drive the light source. The standard conditions can be defined using any suitable conditions, for example, using room temperature as the preset temperature and / or using a specific measurement required to drive the light source (measured at a given forward current at room temperature), although other standard conditions are possible, so that the corrected spectrum can be compared to a reference spectrum determined under precisely known or standardized conditions.

[0094] To determine the correction factor, particularly the correction function, one or more calibration measurements can be performed. The correction can then be based on one or more calibration measurements. For example, the calibration measurement can determine at least one detector signal for an electrically measurable quantity, optionally as a function of the detected wavelength. As described above, at least one condition can be determined as a standard condition, e.g., at least one specific electrically measurable quantity required to drive the light source. For example, an electrically measurable quantity measured at room temperature can be predetermined for each wavelength to define the standard condition. The correction factor can then be determined for each wavelength by determining the ratio of the detector signal measured for the specific electrically measurable quantity to the detector signal measured for the predetermined standard electrically measurable quantity. Thus, particularly when the information indicative of the electrically measurable quantity indicates that the quantity deviates from the standard electrically measurable quantity, the correction factor can be selected so that the corrected detector signal corresponds to the detector signal measured when the conditions are identical to the predetermined standard condition (e.g., room temperature). Additionally or alternatively, the temperature can be intentionally varied, e.g., set or adjusted to two or more target temperatures. Specifically, the standard conditions may include a set of two or more predefined target temperatures and / or corresponding sets of electrically measurable quantities. At each temperature, the electrically measurable quantities and detector signals are measured (e.g., for each wavelength). Correction factors can then be determined as described above.

[0095] In particular, the correction may be based on a model that describes the spectral characteristics of the light source as a function of the electrically measurable quantity and / or temperature. The model may be empirical, semi-empirical, or theoretical. For example, as described in more detail below, the effect on the spectrum of a change in the electrically measurable quantity required to drive the light source may be measured by one or more calibration measurements using a standardized or reference object and measuring the spectrum as the electrically measurable quantity. A correction may then be determined, for example, by using a particular electrically measurable quantity as a reference and correcting spectra measured with other electrically measurable quantities to correspond to the standardized spectrum.

[0096] At least one model describing the changes in the spectrum and / or spectroscopic information in the object relative to the electrically measurable quantities and / or at least one model describing the corrections required to correct the spectrum and / or spectroscopic information in the object depending on the electrically measurable quantities can be determined in advance and stored, for example, in at least one data storage device of the spectroscopic device.

[0097] As further described above, the evaluation unit can be configured to correct at least one detector signal using a correction. For example, the evaluation unit can be configured, via software programming, to convert the detector signal (e.g., a spectrum derived therefrom) directly or indirectly into a corrected detector signal (e.g., a corrected spectrum). For example, as further described above, the correction can specifically include multiplying the at least one detector signal (i.e., a "raw" detector signal or a derivative thereof, e.g., a spectrum generated using the detector signal) by at least one correction factor. This allows for spectral correction that takes into account electrically measurable quantities required to drive the light source as correction parameters. The evaluation unit can particularly be configured to derive spectroscopic information using the corrected detector signal. For example, the detector may be configured to generate detector signals in at least one spectral range, in particular in at least two different spectral ranges in the light emitted from the object, particularly in at least one spectral range sequentially or simultaneously. For example, a detector configured as described above may include an array of light-sensitive elements, each of which is sensitive to a different spectral range or configured to be exposed to light in a different spectral range. The evaluation unit may be configured to individually correct the detector signals in the different spectral ranges and to derive the spectroscopic information by combining the individually corrected detector signals. Thereby, the individually corrected detector signals may be combined, for example, to generate a corrected spectrum.

[0098] Thus, in general, the detector may comprise an array of light-sensitive elements, each of which may be configured to generate at least one detector signal. The evaluation unit may generally be configured to correct each detector signal individually and to derive spectroscopic information by combining the detector signals. In particular, if each light-sensitive element is sensitive to a different spectral range or is exposed to light in different spectral ranges (e.g., by one or more appropriate filters arranged in the detection light path), the influence of the correction parameter as an electrically measurable quantity and / or the influence of temperature can be corrected for each light-sensitive element individually.

[0099] This method, in particular step e. of the method, may be computer-implementable. The term "computer-implementable" is used herein in a broad sense and has the meaning normally understood by a person skilled in the art, without being limited to any specific or customized meaning. This term may particularly, but without limitation, describe a process that is fully or partly performed using a processing means, e.g., a data processing means including at least one processing unit. This method, in particular step e., may be computer-implementable or at least computer-controlled or computer-assisted, using an evaluation unit of the spectroscopic device.

[0100] In yet another aspect of the present invention, a computer program is disclosed that includes instructions that, when executed by a spectroscopic device according to the present invention (e.g., according to any of the embodiments disclosed in detail above or in more detail below), cause the spectroscopic device to perform a method of the present invention (e.g., according to any of the embodiments disclosed in detail above or in more detail below).

[0101] Similarly, computer-readable storage media, and particularly non-transitory computer-readable storage media, are disclosed that include instructions stored thereon that, when executed by a spectroscopic device in accordance with the present invention (e.g., according to any one of the embodiments disclosed in detail above or any one of the embodiments disclosed in more detail below), cause the spectroscopic device to perform a method in accordance with the present invention (e.g., according to any one of the embodiments described above or any one of the embodiments disclosed in more detail below).

[0102] In this specification, the terms "computer-readable data carrier," "computer-readable storage medium," and "non-transitory computer-readable medium" are broad terms and are intended to have the meanings that are commonly understood by those skilled in the art, and are not limited to any particular or customized meaning. These terms may particularly, but not exclusively, refer to data storage means, especially non-transitory data storage means, such as hardware storage media that store computer-executable instructions. A computer-readable data carrier or storage medium or computer-readable medium may in particular be or include storage media such as random access memory (RAM) and / or read-only memory (ROM).

[0103] The spectroscopic device and method of the present invention, in one or more of the embodiments described above and / or in one or more of the embodiments described in detail below, offer numerous advantages over similar devices and methods. Specifically, the spectroscopic device and method for acquiring spectroscopic information of at least one object minimize hardware efforts to correct for external and / or internal influences, such as temperature, on the spectroscopic device. Based on BDI circuits, the spectroscopic device can provide a measurement device capable of measuring different physical quantities with high resolution with little additional hardware adjustment. One or more BDI circuits can be used to generate electrically measurable quantity information required to read out detectors (particularly one or more photoconductive detectors) and drive light sources. Such a multi-channel readout ASIC allows synchronous sampling of optical and electrical signals. This allows corresponding measurements of other components to be performed for each optical measurement and used for compensation. The ROIC can particularly include multiple channels, each containing one or more BDI circuits. The BDI circuits can be connected to a bias voltage V Bias By applying a bias voltage, the voltage applied to the detector can be kept constant. Current due to the applied voltage can be removed by current skimming, eliminating signal offset. Changes in detector resistance due to illumination can cause an increase in current, which can be digitized by an analog-to-digital converter (ADC) with relatively high time and voltage resolution. The bias voltage can be adjustable depending on the measurement task.

[0104] As an example, the light source may include an LED. The current in the LED is controlled by a constant current I setThe voltage change is minimized within the selected current range, especially when the LED is set to maintain a constant output power level. For example, the LED current can be selected so that the LED's forward voltage varies between 2.7 V and 2.9 V depending on the temperature. The ROIC can set the BDI input voltage to a constant value of 2.6 V. This allows for accurate analysis of the electrically measurable quantity required to drive the light source within the approximately 0.1 V to 0.3 V range of interest by connecting a resistor (especially one with a low temperature coefficient) between the LED anode and the ROIC input. However, different input voltages may be appropriate for other light sources. Therefore, the BDI may function as an offset cancellation circuit.

[0105] Specifically, V LED driver -V Bias may be applied to a resistor to generate a current that can be digitized. This allows the change in the forward voltage of the LED due to temperature changes to be measured with high precision. For example, the temperature may change from 20°C to 30°C. The voltage drop across the resistor may be determined by:

[0106]

number

[0107]

number

[0108]

number

[0109] Using an exemplary resistor of R=2 MΩ, a measurement current of 50 nA to 150 nA may be achieved. The ROIC may be configured to have 24-bit resolution in this voltage and current range. Thus, in this example, the voltage and current resolution is

number

number

[0110] Although the absolute accuracy of the measured voltage may be reduced by several factors, such as the tolerance of the BDI voltage and the tolerance of the resistors, it is nevertheless possible to monitor the relative change in the forward voltage with high accuracy, which can be used to compensate for changes in the LED output power and thus for changes in the detector optical signal.

[0111] In yet another example, the spectrometer device can further include at least one shunt resistor to measure the LED voltage drop and LED current. In this case, the input current of the ROIC can be ignored. This allows the electrical input power to the LED to be monitored in addition to the forward voltage, which can improve the accuracy of optical signal compensation. In this type of operation mode, matched readout IC channels may be required to prevent inherent offsets from causing current offsets. Each side of the shunt resistor may be electrically connected to a multi-channel readout integrated circuit via at least one resistor. This configuration enables a high-resolution, short-term, time-based power drift compensation method, particularly improving the accuracy of the detector reading. While overall power measurement is not necessarily highly accurate, high resolution is available for relative compensation methods. Additionally, if the thermal characteristics of the light source (thermal capacity and / or conductivity to the PCB and / or conversion efficiency) are known, the temperature of the light source can be estimated from the power consumed by the light source.

[0112] Both measurement examples (specifically the light source forward voltage measurement and / or power measurement) can be performed at different stages in the spectrometer device's life (e.g., final inspection, open port measurement, measurement itself, calibration measurement, etc.) Additionally, when using multiple light sources, potential drift effects may be common to all light sources or may be specific to a single light source, allowing for determination of whether the drift occurs in the ROIC or in the light source itself.

[0113] Additionally or alternatively, the ROIC can be used to monitor additional light source types with different electrical and optical characteristics. For example, the light source may include an incandescent light source. The filament of an incandescent lamp may be a metallic resistor. Therefore, the heating of the light source may follow Joule's law, and the emitted radiation may follow Planck's law. By measuring the current through the filament and the applied voltage, the resistance of the filament may be determined, which may be temperature dependent. By keeping the filament resistance constant through a current and voltage control loop, the spectrum emitted by the light source can also be stabilized. This skimming current compensation is applicable to both forward voltage measurements and power consumption measurements.

[0114] Alternatively or additionally, a negative thermal coefficient thermistor (NTC) may be used for direct temperature measurement. By placing the NTC next to or in direct contact with the light source, it is possible to monitor the temperature, and therefore the light output of the light source, by measuring the resistance of the NTC.

[0115] The spectroscopic devices and methods of the present invention allow for particularly high speed sampling, which may allow high frequency noise of the light source input via voltage and power measurements to be correlated with the light source output via the detector signal, thereby improving the signal-to-noise ratio of the measured detector signal.

[0116] In this specification, the terms "have," "include," "or," or any grammatical variations thereof are used in a non-exclusive sense. Thus, these terms refer to both a situation in which the subject matter described in this context has no other features other than the features introduced by these terms, and a situation in which one or more additional features are present. For example, the expressions "A has B," "A includes B," and "A encompasses B" can refer to both a situation in which no other elements are present in A other than B (i.e., a situation in which A consists only of B), and a situation in which one or more additional elements are present in A other than B (e.g., element C, elements C and D, or further elements).

[0117] Furthermore, the use of "at least one," "one or more," or similar phrases indicating that a feature or element may be present more than one time will typically only be used once to introduce that feature or element. In most cases, the phrase "at least one" or "one or more" will not be repeated when referring to that feature or element, even if the feature or element is present more than one time.

[0118] Furthermore, in this specification, the terms "preferably," "more preferably," "particularly," "more particularly," "particularly," "more particularly," or similar terms are used to indicate optional features and do not limit alternative possibilities. Features introduced with these terms are therefore optional features and are not intended to limit the scope of the claims in any way. As one skilled in the art will recognize, the present invention can be practiced using alternative features. Similarly, features introduced with "in one embodiment of the present invention" or similar expressions are intended as optional features, without any limitations on alternative embodiments of the invention, on the scope of the invention, or on the possibility of combining features introduced in this way with other optional or required features of the invention.

[0119] In summary and without excluding further possible embodiments, the following embodiments are envisaged: "Embodiment 1" 1. A spectroscopic device for obtaining spectroscopic information of at least one object, comprising: i. at least one light source for generating illumination light for illuminating an object; ii. at least one detector that detects the detected light from the object and generates at least one detector signal; iii. at least one driving unit for electrically driving the light source; iv. at least one multi-channel readout integrated circuit, each channel of the multi-channel readout integrated circuit including at least one buffered direct injection (BDI) circuit configured for readout of a detector signal, the BDI circuit configured to generate at least one electrically measurable quantity necessary to drive a light source (114), the multi-channel readout integrated circuit including at least one multi-channel readout application-specific integrated circuit (ASIC) configured for synchronously sampling the detector signal and the electrically measurable quantity necessary to drive the light source (114); and v. at least one evaluation unit for evaluating at least one detector signal generated by the detector and deriving spectroscopic information of the object from the detector signal, the evaluation unit being configured to take into account information about an electrically measurable quantity necessary to drive the light source when deriving the spectroscopic information from the detector signal; 1. A spectroscopic device comprising:

[0120] "Embodiment 2" 2. The spectroscopic device of embodiment 1, wherein the light source is configured to emit light in a spectral range that includes at least a part of the infrared spectral range, in particular the near-infrared spectral range, more in particular the spectral range from 760 nm to 3 μm, even more in particular the spectral range from 1 μm to 3 μm, preferably the spectral range from 1.3 μm to 2.5 μm, more preferably the spectral range from 1.5 μm to 2.2 μm.

[0121] "Embodiment 3" The spectroscopic device of embodiment 1 or 2, wherein the light source comprises at least one light source selected from the following group: incandescent lamps; light-emitting diodes (LEDs); lasers, particularly laser diodes, solid-state lasers, gas lasers, quantum cascade lasers; plasma light sources; low-pressure discharge lamps, particularly low-pressure fluorescent lamps; high-pressure discharge lamps; and electric light sources.

[0122] "Embodiment 4" 4. The spectroscopic device of any one of embodiments 1 to 3, wherein the light source comprises at least one light emitting diode and at least one luminescent material for photoconversion of primary light generated by the light emitting diode.

[0123] "Embodiment 5" A spectrometer device described in any one of embodiments 1 to 4, wherein the information on the electrically measurable quantity required to drive the light source includes at least one piece of information selected from the following group: forward voltage at the light source; voltage drop at the light source; current at the light source; electrical input power at the light source; resistance of the light source; impedance of the light source.

[0124] "Embodiment 6" 6. The spectroscopic device of any one of embodiments 1 to 5, wherein the multi-channel read-only integrated circuit (ASIC) comprises at least one skimming circuit configured for current skimming of the current in the detector.

[0125] "Embodiment 7" The spectrometer device of embodiment 6, wherein the skimming circuit includes one or more programmable current sinks including one or more transistors, particularly multiple transistors, which are arranged in parallel with the same size or in series with double the size.

[0126] "Embodiment 8" The spectroscopic device according to any one of embodiments 1 to 7, further comprising at least one resistor electrically connecting the light source and the multi-channel readout integrated circuit.

[0127] "Embodiment 9" The spectrometer device according to any one of embodiments 1 to 8, further comprising at least two resistors electrically connecting the light source and the multi-channel readout integrated circuit, and at least one shunt resistor, each end of the shunt resistor being electrically connected to the multi-channel readout integrated circuit via at least one resistor.

[0128] "Embodiment 10" 10. The spectroscopic device of embodiment 8 or 9, wherein the resistor and / or shunt resistor has a temperature coefficient of less than 1000 ppm / K, in particular less than 100 ppm / K, more in particular less than 50 ppm / K, more in particular less than 10 ppm / K.

[0129] "Embodiment 11" A spectroscopic device according to any one of embodiments 1 to 10, wherein the detector comprises a plurality of light-sensitive elements, in particular an array of light-sensitive elements, each light-sensitive element being configured to generate at least one detector signal, and the evaluation unit is configured to derive spectroscopic information by individually considering the information of electrically measurable quantities required to drive the light source corresponding to the detector signal of each light-sensitive element and combining the detector signals.

[0130] "Embodiment 12" 12. The spectroscopic device of embodiment 11, wherein the light-sensitive elements are configured to be sensitive to different spectral ranges of light from the object.

[0131] "Embodiment 13" The spectroscopic device of embodiment 12, wherein the spectroscopic device comprises at least one wavelength-selective element disposed in the detection light path, the wavelength-selective element being configured to expose each light-sensitive element to a respective spectral range of the detected light from the object.

[0132] "Embodiment 14" The spectrometer device according to any one of embodiments 1 to 13, further comprising at least one wavelength selection element, the wavelength selection element including at least one of a wavelength selection element arranged in the optical path of the illumination light and a wavelength selection element arranged in the optical path of the detection light.

[0133] "Embodiment 15" 15. The spectroscopic device of embodiment 14, wherein the wavelength-selective element is selected from the group of an adjustable wavelength-selective element and a wavelength-selective element having a fixed transmission spectrum.

[0134] "Embodiment 16" 16. The spectroscopic device of embodiment 15, wherein the wavelength-selective element having a fixed transmission spectrum comprises at least one filter element, particularly at least one absorption filter element, more particularly a bandpass filter element.

[0135] "Embodiment 17" 17. The spectroscopic device of embodiment 15 or 16, wherein the tunable wavelength-selective element comprises at least one tunable interferometer, in particular at least one MEMS Fabry-Perot interferometer or MEMS Michelson interferometer.

[0136] "Embodiment 18" 1. A method for obtaining spectroscopic information of at least one object using a spectroscopic device, comprising the steps of: a. electrically driving at least one light source using at least one driving unit; b. illuminating the object with illumination light generated by the light source; c. generating at least one detector signal by detecting the detection light from the object with at least one detector; d. generating at least one information related to an electrically measurable quantity required to drive the light source using at least one multi-channel readout integrated circuit, each channel of the multi-channel readout integrated circuit including at least one buffered direct injection (BDI) circuit, the BDI circuit configured to read out a detector signal, the BDI circuit configured to generate information related to the at least one electrically measurable quantity required to drive the source, the multi-channel readout integrated circuit including at least one multi-channel readout application-specific integrated circuit (ASIC) configured to synchronously sample the detector signal and the at least one information related to the electrically measurable quantity required to drive the light source; and e. evaluating at least one detector signal generated by the detector using at least one evaluation unit and deriving spectroscopic information of the object from the detector signal taking into account information about electrically measurable quantities necessary for driving the light source; A method comprising:

[0137] "Embodiment 19" The method according to embodiment 18, wherein the spectrometer device according to any one of embodiments 1 to 17 is used.

[0138] "Embodiment 20" 20. The method according to embodiment 18 or 19, wherein steps c. and d. are performed overlappingly, in particular in parallel, as appropriate.

[0139] "Embodiment 21" 21. The method according to any one of embodiments 18 to 20, which is performed online on-site.

[0140] "Embodiment 22" 22. A method according to any one of embodiments 18 to 21, wherein in step e., at least one correction is determined from an item of information of an electrically measurable quantity required to drive the light source, and further, the at least one detector signal is corrected using said correction.

[0141] "Embodiment 23" 23. The method of embodiment 22, wherein the corrections include at least one temperature correction, the temperature corrections depending at least in part on information of an electrically measurable quantity required to drive the light source.

[0142] "Embodiment 24" 24. The method of embodiment 22 or 23, wherein the correction comprises multiplying at least one detector signal by at least one correction factor.

[0143] "Embodiment 25" 25. The method according to any one of embodiments 22 to 24, wherein the corrected detector signal is used to derive spectroscopic information.

[0144] "Embodiment 26" 26. The method according to any one of embodiments 18 to 25, wherein at least step e of the method is computer-implemented.

[0145] "Embodiment 27" A computer program including instructions, which when executed by a spectroscopic device according to any one of embodiments 1 to 17, cause the spectroscopic device to carry out a method according to any one of embodiments 18 to 26.

[0146] "Embodiment 28" A computer-readable recording medium, in particular a non-transitory computer-readable recording medium, comprising instructions that, when executed by a spectroscopic device according to any one of embodiments 1 to 17, cause the spectroscopic device to perform the method according to any one of embodiments 18 to 26. [Brief explanation of the drawings]

[0147] Furthermore, optional features and embodiments are disclosed in the detailed description of the embodiments, preferably in combination with the dependent claims. In this case, each optional feature may be realized in an isolated form or in any feasible combination, as understood by those skilled in the art. The scope of the invention is not limited to the preferred embodiments. The embodiments are illustrated schematically in the drawings. In these drawings, the same reference numerals represent the same or functionally equivalent elements. [Figure 1] FIG. 1 shows a schematic diagram of the spectrometer setup. [Figure 2] FIG. 2 shows a schematic cross-sectional view of a light source. [Figure 3] FIG. 3 shows a schematic flow chart illustrating the generation and processing of detector signals. [Figure 4] FIG. 4 shows a diagram illustrating the infrared emission spectrum superposition of a phosphor LED. [Figure 5]FIG. 5 shows a diagram illustrating the temperature-dependent change in light output for a selected number of wavelengths. [Figure 6] FIG. 6 shows a plot of forward voltage versus temperature at selected currents. [Figure 7] 7A and 7B show the spectra of two different phosphor LEDs. [Figure 8] 8A and 8B show graphs illustrating the wavelength dependence of the decay constant (FIG. 8A) and growth constant (FIG. 8B) of a phosphor LED emitting in the wavelength range of 1.3 μm to 2 μm. [Figure 9] 9A and 9B show the decay constant (FIG. 9A) and growth constant (FIG. 9B) as a function of wavelength for a phosphor LED emitting in the wavelength range of 1.6 μm to 2.1 μm. [Figure 10] FIG. 10 shows a plot of normalized light output as a function of forward current. [Figure 11] FIG. 11 shows a flow chart illustrating an embodiment of a method for obtaining spectroscopic information of at least one object using a spectroscopic device. [Figure 12] 12A-12D show different embodiments of exemplary channels of a ROIC. [Figure 13] FIG. 13 shows a diagram illustrating the current-voltage characteristics of a light-emitting diode (LED). DETAILED DESCRIPTION OF THE INVENTION

[0148] FIG. 1 shows a schematic diagram of a spectroscopic device 110 for obtaining spectroscopic information of at least one object 112. As shown in FIG. 1, the spectroscopic device 110 may include multiple components. The components of the spectroscopic device 110 and their interactions are described below with reference to FIG. 1. The spectroscopic device 110 includes at least one light source 114 that generates illumination light 116 for illuminating the object 112. The light source 114 may be a tunable light source, a light source having at least one fixed emission wavelength, or a broadband light source, or a combination thereof. The light source 114 may be or include at least one electric light source. The light source 114 includes a light-emitting diode 118 and at least one luminescent material 120 for photoconverting primary light generated by the light-emitting diode 118. For example, the light-emitting diode 118 may include one or more of the following: a light-emitting diode (LED) based on spontaneous emission, a light-emitting diode based on superluminescence (sLED), or a laser diode (LLED).

[0149] The LED 118 may specifically include at least two semiconductor material layers 121 configured such that light is generated by recombination of positive and negative electrical charges at the interface between the at least two semiconductor material layers 121. The at least two semiconductor material layers 121 may have different electrical properties, for example, at least one layer being an n-type doped semiconductor material 121 and at least one layer being a p-type doped semiconductor material 121. Thus, for example, the LED 118 may include at least one pn junction and / or at least one pin arrangement, although other device structures are also possible.

[0150] The light-emitting diode 118 generates primary light, also referred to as "pump light." The primary light may be converted into "secondary light," for example, by photoconversion via one or more luminescent materials 120 (e.g., phosphor materials). Thus, at least one luminescent material 120 may form at least one converter (also referred to as an optical converter), which converts the primary light into secondary light having spectral characteristics different from those of the primary light. In particular, the spectral width of the secondary light may be wider than that of the primary light, and / or the central wavelength of the secondary light may be shifted (e.g., red-shifted) relative to the primary light. In particular, the at least one luminescent material 120 may have absorption in the ultraviolet and / or blue spectral region and emission in the near-infrared and / or infrared spectral region. The illumination light 116 may be or include a mixture of the primary light or a portion thereof, the secondary light or a portion thereof, or both.

[0151] As shown in FIG. 1 , the light source 114 may specifically include a phosphor light-emitting diode 122 (also referred to as a phosphor LED 122). The phosphor LED 122 may be a combination of at least one light-emitting diode 118 configured to generate primary light or pump light and at least one luminescent material 120 (phosphor) configured to photoconvert the primary light generated by the light-emitting diode 118. The phosphor LED 122 may form a packaged LED light source, which includes an LED die 124 (e.g., a blue LED emitting blue pump light) and a phosphor, which, for example, fully or partially coats the LED 118 and is configured to convert the primary light or blue light into light with different spectral characteristics, specifically near-infrared light. FIG. 2 shows a more detailed view of the light source 114 implemented as a phosphor LED 122.

[0152] In general, the light source 114 can be realized in various forms. Thus, for example, as shown in Figure 1, the light source 114 can be configured as part of the spectroscopic device 110, disposed within a housing 126 of the spectroscopic device 110. However, alternatively or additionally, at least one light source 114 can be disposed outside the housing 126, e.g., as a separate light source 114 not shown. The light source 114 can be disposed at a location remote from the object 112 and configured to illuminate the object 112 (see Figure 1).

[0153] Illumination light 116 generated by light source 114 may propagate from light source 114 to object 112. In Figure 1, the illumination light 116 generated by light source 114 and propagating to object 112 is indicated by an arrow. Object 112 may, among other things, include at least one sample that can be analyzed completely or partially by spectroscopy.

[0154] As can be seen in FIG. 1 , the spectroscopic device 110 includes at least one detector 128 for detecting detected light 130 detected from the object 112. Light propagating from the light source 114 to the object 112 can be referred to as “illumination light 116,” while light propagating from the object 112 to the detector 128 is referred to as “detected light 130.” In FIG. 1 , the detected light 130 is indicated by an arrow. The detected light 130 may include illumination light 116 reflected by the object 112, illumination light 116 scattered by the object 112, illumination light 116 transmitted by the object 112, luminescence light generated by the object 112, e.g., fluorescent light or fluorescence light generated by the object 112 after the object 112 is optically, electrically, or acoustically stimulated by the illumination light 116 or similar light. Thus, the detected light 130 may be generated directly or indirectly by illuminating the object 112 with the illumination light 116.

[0155] The detector 128 may be or may include at least one optical detector 132. The optical detector 132 may be configured to measure at least one optical parameter, such as the intensity and / or power of light irradiating at least one photosensitive area of ​​the detector 128. More particularly, the optical detector 132 may include at least one light-sensitive element and / or at least one optical sensor, such as at least one of a photodiode, a photocell, a photosensitive resistor, a phototransistor, a thermophilic sensor, a photoacoustic sensor, a pyroelectric sensor, a photomultiplier, or a bolometer. The detector 128 may therefore be configured to generate at least one detector signal in the above sense, more particularly at least one electrical detector signal, which provides information about at least one optical parameter, such as the power and / or intensity of light irradiating the detector 128 or a photosensitive area of ​​the detector 128.

[0156] The detector 128 may include a single light-sensitive element or region, or multiple light-sensitive elements or regions. As shown in FIG. 1, the detector 128 may include at least one detector array, more particularly an array of light-sensitive elements 134. Each light-sensitive element 134 may also be configured to generate at least one detector signal. In particular, each light-sensitive element 134 may include at least one light-sensitive region adapted to generate an electrical signal in response to the intensity of the incident light, which electrical signal is provided to an evaluation unit 136 of the spectroscopic device 110, as described below.

[0157] If the detector 128 comprises an array of light-sensitive elements 134, the detector 128 may be selected, for example, from known pixel sensors, and in particular from CCD or CMOS chips. Alternatively, the detector 128 may be or include a photoconductor in general, in particular an inorganic photoconductor, in particular PbS, PbSe, Ge, InGaAs, extended InGaAs, InSb, or HgCdTe. As a further alternative, it may include at least one of pyroelectric, bolometer, or thermopile detector elements.

[0158] The spectroscopic device 110 includes at least one evaluation unit 136 for evaluating at least one detector signal generated by the detector 128 and deriving spectroscopic information of the object 112 from the detector signal. The detector 128 may provide the detector signal to the evaluation unit 136 directly or indirectly. Thus, the detector 128 and the evaluation unit 136 may be directly or indirectly connected, as shown by the arrows in FIG. 1 . The detector signal may be used as a “raw” detector signal and / or may be processed or pre-processed (e.g., filtered, etc.) before further use. Thus, the detector 128 may include at least one processing unit and / or at least one pre-processing unit (e.g., amplifier, analog-to-digital converter, electrical filter, Fourier transform, etc.).

[0159] As shown in FIG. 1 , the spectroscopic device 110 further includes at least one driving unit 138 for electrically driving the light source 114. In particular, the driving unit 138 may be configured to supply an electric current to the LED 118 and control the electric current through the LED 118. For example, the driving unit 138 may be configured to adjust a voltage supplied to the LED 118, the voltage being required to achieve a specific electric current through the LED 118. The driving unit 138 may specifically include at least one of the following: a current source 140, a voltage source. In particular, the driving unit 138 may include at least one current source 140 for supplying at least one predetermined current to the LED 118, where the current source 140 is configured to adjust or control the voltage applied to the LED 118 to generate the predetermined current. The driving unit 138 may also include one or more electrical components, such as an integrated circuit, for driving the light source 114. The drive unit 138 may be fully or partially integrated into the light source 114, or may be separate from the light source 114, the latter configuration being shown in FIG.

[0160] The spectrometer device 110 further includes at least one multi-channel readout integrated circuit 139. Each channel of the multi-channel readout integrated circuit 139 includes at least one buffered direct injection (BDI) circuit 141. The BDI circuit 141 is configured for readout of the detector signal. The BDI circuit 141 is configured to generate at least one electrically measurable quantity necessary to drive the light source 114. The multi-channel readout integrated circuit 139 includes at least one multi-channel read-only integrated circuit (ASIC) 142 configured to synchronously sample the detector signal and the electrically measurable quantity necessary to drive the light source 114. Possible embodiments of the multi-channel readout integrated circuit 139 are shown in Figures 12A to 12D. Therefore, for a detailed description of the ROIC, reference is made to the descriptions of Figures 12A to 12D.

[0161] As described above, the BDI circuit 141 may also be configured to generate at least one electrically measurable quantity, particularly a positive voltage, necessary to drive the light source 114 (particularly the light emitting diode 118). The positive voltage may be applied to the LED 118 in a direction (positive direction) connecting the positive terminal of the voltage or current source 140 to the p-layer of the LED 118 and the negative terminal to the n-layer of the LED 118, thereby causing a predetermined electrical current to flow through the LED 118. For example, the predetermined current defining the positive voltage may be a current known to produce a predetermined light output of the light source 114 and / or the light emitting diode 118.

[0162] As explained above, as shown in FIG. 1 , the spectroscopic device 110 includes at least one evaluation unit 136 that evaluates at least one detector signal generated by the detector 128 and derives spectroscopic information of the object 112 from the detector signal. The evaluation unit 136 is configured to take into account information related to at least one electrically measurable quantity, in particular the forward voltage, when deriving the spectroscopic information from the detector signal. In particular, the evaluation unit 136 may also be configured to process at least one input signal and generate its at least one output signal. The at least one input signal may, for example, include at least one detector signal provided directly or indirectly from the at least one detector 128 and at least one signal provided directly or indirectly from the ROIC 139, which signal includes at least one item of information related to the at least one electrically measurable quantity, in particular the forward voltage. In the embodiment shown in FIG. 1, the arrow between the drive unit 138 (which at least partly includes the ROIC 139) and the evaluation unit 136 in FIG. 1 indicates the provision of a signal to and / or the acquisition of a signal by the evaluation unit 136, which signal includes at least one item of information relating to at least one electrically measurable quantity, in particular information relating to the forward voltage.

[0163] The evaluation unit 136 may be or may include one or more integrated circuits (e.g., one or more application-specific integrated circuits (ASICs)) and / or one or more data processing devices 144 (e.g., one or more computers, digital signal processors (DSPs), field-programmable gate arrays (FPGAs), preferably one or more microcomputers and / or microcontrollers). Additional components may also be included, such as one or more pre-processing devices 146 and / or data acquisition devices (e.g., one or more devices for receiving and / or pre-processing detector signals, such as one or more AD converters and / or one or more filters). Furthermore, the evaluation unit may also include one or more data storage devices 148, as shown in FIG. 1 . Furthermore, the evaluation unit 136 may include one or more interfaces, such as one or more wireless interfaces and / or one or more wired interfaces.

[0164] In particular, the evaluation unit 136 may be configured, for example by software programming, to determine at least one correction from information related to the at least one electrically measurable quantity, in particular a correction based on a model describing the spectral characteristics of the light source 114 as a function of the at least one electrically measurable quantity, in particular the forward voltage. The evaluation unit 136 may further be configured to correct the at least one detector signal using the correction. The correction may include multiplying the at least one detector signal by at least one correction factor, as described in detail above and exemplarily further described below. The evaluation unit 136 may be configured, in particular, to derive spectroscopic information using the corrected detector signal.

[0165] As described in detail above, the detector 128 may specifically include an array of light-sensitive elements 134. Each light-sensitive element may be configured to generate at least one detector signal. The evaluation unit 136 may be configured to individually correct each detector signal and combine the detector signals to derive spectroscopic information. The spectroscopic device 110 may be configured such that the light-sensitive elements of the detector 128 are sensitive to different spectral ranges of light from the object 112. In particular, the detector 128 may be configured to generate detector signals corresponding to at least two different spectral ranges of light from the object 112, and may be configured to generate detector signals corresponding to at least one spectral range sequentially or simultaneously. The spectroscopic device 110 may specifically include at least one filter element 150 arranged in the optical path of the light from the object 112. The filter element 150 may be configured such that each light-sensitive element is exposed to a respective spectral range of light from the object 112.

[0166] The spectroscopic device 110 may further include one or more optical components 151, such as at least one mirror, at least one lens, at least one aperture, and at least one wavelength-selecting element 152. Specifically, the one or more optical components 151 may be arranged in at least one of the optical path of the illumination light 116 or the optical path of the detection light 130. The spectroscopic device 110 may, in particular, include at least one wavelength-selecting element 152. The wavelength-selecting element 152 may, in particular, be selected from the group consisting of an adjustable wavelength-selecting element 152 and a wavelength-selecting element 152 with a fixed transmission spectrum. For example, when an adjustable wavelength-selecting element 152 is used, different wavelength ranges can be selected sequentially. On the other hand, when a wavelength-selecting element 152 with a fixed transmission spectrum is used, the selection of the wavelength range is fixed but may depend, for example, on the position of the detector. The wavelength-selective element 152 may be used to separate the incident light into a spectrum of constituent wavelength signals and measure the intensity of each wavelength signal using a detector (e.g., detector 128 of the spectroscopic device 110), which may include the array of light-sensitive elements 134. The at least one wavelength-selective element 152 may include, for example, at least one of a filter, a diffraction grating, or a prism. The wavelength-selective element 152 may include, among other things, at least one wavelength-selective element 152 disposed in the optical path of the illumination light 116 and at least one wavelength-selective element 152 disposed in the optical path of the detection light 130. FIG. 1 illustrates an embodiment of the spectroscopic device 110 in which one wavelength-selective element 152 is disposed in the optical path of the illumination light 116 and one wavelength-selective element 152 is disposed in the optical path of the detection light 130.

[0167] 1 is configured to acquire spectroscopic information about at least one object 112. In particular, the spectroscopic device 110 can be configured to acquire information about the at least one object 112 and / or radiation emitted by the at least one object 112, i.e., information characterizing at least one optical property of the object 112, more particularly information characterizing at least one optical property of the at least one object 112, e.g., information qualitatively or quantitatively assessing at least one of transmission, absorption, reflection, or emission of the at least one object 112. For example, the at least one spectral information can also include at least one intensity information, e.g., information about the intensity of light transmitted, absorbed, reflected, or emitted by the object 112, e.g., as a function of one or more wavelengths, e.g., at wavelength or wavelength sub-ranges, e.g., at wavelength ranges. Accordingly, the spectroscopic device 110 may be configured to acquire at least one spectrum, or at least a portion of a spectrum, of the detected light 130 propagating from the object 112 to the detector 128. The spectrum may describe the spectral flow in units of radiant energy, e.g., in watts per nanometer (W / nm), or may be expressed in other units, e.g., as a function of wavelength of the detected light 130. Thus, the spectrum may describe the optical power of light in a particular wavelength band, e.g., within the near-infrared (NIR) spectral range. The spectrum may include one or more optical variables as a function of wavelength, e.g., power spectral density, an electrical signal derived from an optical measurement, etc. Examples of spectra are shown, e.g., in FIGS. 4, 7A, and 7B. The spectroscopic device 110 may be a portable spectroscopic device 110, particularly one that can be used in the field.

[0168] FIG. 2 shows a schematic cross-sectional view of a light source 114. The at least one light source 114 of the spectroscopic device 110 may be configured to generate or provide electromagnetic radiation in one or more of the infrared, visible, or ultraviolet spectral ranges. Because many properties related to the material properties or chemical composition of the object 112 are derived from the near-infrared spectral range, the light used in typical applications of the present invention is light in the infrared (IR) spectral range, more preferably light in the near-infrared (NIR) and / or mid-infrared (Mid-IR) spectral range, particularly light with wavelengths between 1 μm and 5 μm, preferably between 1 μm and 3 μm. The light source 114 includes at least one light-emitting diode 118 and at least one luminescent material 120 for photoconversion of primary light generated by the light-emitting diode 118. The LED 118 and luminescent material 120 may comprise a phosphor LED 122, as described above.

[0169] The phosphor LED 122 shown in FIG. 2 may include one or more functional components. Specifically, the phosphor LED 122 may include one or more substrates 154, particularly one or more electrically insulating substrates 154. In particular, the phosphor LED 122 may include one or more ceramic substrates 156, as shown in FIG. 2. The substrates 154 may be configured to support at least one LED die 124 and at least one luminescent material 120. Furthermore, the at least one substrate 154 may support or include at least one contact pad 158 and / or at least one electrical connection component (e.g., at least one metal contact and / or at least one metal lead), as shown in FIG. 2. The substrate 154 may also be configured to function as a heat sink. Heat may be generated in the LED die 124 due to limited conversion of electrical energy to light energy, and heat may also be generated in the luminescent material 120, for example, during the conversion process. The heat may be dissipated by the substrate 154, such as a ceramic substrate.

[0170] As shown in FIG. 2, the phosphor LED 122 can include a light-emitting diode 118. The light-emitting diode 118 can be configured to convert an electrical current into primary light (e.g., blue primary light) using at least one LED chip and / or at least one LED die 124, as shown in FIG. 2. Specifically, a pn diode can be used. For example, one or more LEDs 118 selected from indium gallium nitride (InGaN)-based LEDs 118, GaN-based LEDs 118, InGaN / GaN alloy or combination thereof-based LEDs 118, and / or other LEDs 118 can be used. Additionally or alternatively, a quantum well LED 118 can be used, for example, one or more quantum well LEDs 118 based on indium gallium nitride (InGaN). Additionally or alternatively, a superluminescent LED (sLED) and / or a quantum cascade laser can be used. As further apparent from FIG. 2, the phosphor LED 122 can include at least one luminescent material 120 configured to photoconvert the primary light generated by the light emitting diode 118. Various types of conversion and / or luminescence are known and can be used in the context of the present invention. Specifically, the luminescent material 120 can include at least one of the following: cerium-doped YAG (YAG:Ce3 + , or Y3Al5O 12 :Ce 3+ ); rare earth doped sialon; copper and aluminum doped zinc sulfide (ZnS:Cu,Al).

[0171] The luminescent material 120 may be configured to form at least one layer. Generally, various alternatives for disposing the luminescent material 120 relative to the light-emitting diode 118 are possible, alone or in combination. First, the luminescent material 120 (e.g., at least one layer of the luminescent material 120, e.g., a phosphor) can be disposed directly on the light-emitting diode 118. This includes, for example, cases where no material is present between the LED 118 and the luminescent material 120, or cases where one or more transparent materials (e.g., one or more transparent materials transparent to the primary light) are present between the LED 118 and the luminescent material 120. For example, a coating of the luminescent material 120 can be disposed directly or indirectly on the LED 118 (not shown). Additionally or alternatively, the luminescent material 120 can form, for example, at least one converter body 160 (at least one converter disk), also referred to as a converter platelet. The converter body 160 may be disposed above the LED 118, for example, by adhesively securing the converter body 160 to the LED 118; this arrangement is shown in FIG. 2 . Additionally or alternatively, the luminescent material 120 may be remotely disposed such that primary light emitted from the LED 118 passes through an intermediate optical path before reaching the luminescent material 120 (not shown). For example, the luminescent material 120 in a remote location may form a solid body, such as a disk or converter disk, or the converter body 160. The intermediate optical path may include one or more optical elements, including lenses, prisms, gratings, mirrors, apertures, or combinations thereof. Thus, specifically, an optical system having imaging properties may be disposed in the intermediate optical path between the LED 118 and the luminescent material 120, thereby, for example, focusing or focusing the primary light into the converter body 160.

[0172] In the light source 114, particularly the phosphor LED 122, the at least one luminescent material 120 may be disposed relative to the light emitting diode 118 in a position that allows heat transfer from the light emitting diode 118 to the luminescent material 120. More specifically, the luminescent material 120 may be disposed in a position that allows heat transfer by thermal radiation and / or thermal conduction, more preferably by thermal conduction. Thus, for example, as shown in FIG. 2, the luminescent material 120 may be disposed in thermal and / or physical contact with the light emitting diode 118. This generally couples the temperature of the luminescent material 120 to the temperature of the light emitting diode 118.

[0173] As shown in FIG. 2 , the light source 114, particularly the phosphor LED 122, may include at least one side coating 162 covering at least one side (e.g., top) and at least one side coating 162 covering the bottom and / or at least one side (e.g., at least one side of the substrate 154, contact pads 158, light-emitting diode 118, and luminescent material 120). Specifically, the side coating 162 may cover gaps and / or gaps that may exist in the layered structure of the light source 114, as shown in FIG. 2 . Other components of the light source 114, particularly components not shown in FIG. 2 , are possible. In general, the light source 114, particularly the phosphor LED 122, may be encapsulated (not shown) in a housing 126 not shown in FIG. 2 , or may be configured unencapsulated. Thus, the LED 118 and at least one luminescent material 120 for photoconverting the primary light generated by the LED 118 may be housed within a common housing 126. However, as shown in FIG. 2, the LED 118 may be a bare LED 118 without a housing.

[0174] The schematic flowchart of FIG. 3 illustrates the process of generating a detector signal and processing the detector signal (e.g., generating a correction signal). Specifically, hardware components 164 that may participate in generating and / or preprocessing the detector signal and software components 166 that may participate in processing and / or correcting the detector signal are illustrated in FIG. 3. The hardware components 164 (also referred to simply as "hardware" 164) may include, among other things, at least one light-emitting diode 118 (particularly, blue LED 118) of the spectrometer device 110, which is configured to emit blue primary light. The hardware components 164 may further include a phosphor material 120 (also referred to as phosphor LED 122), an object 112, and one or more optical components 151 (e.g., at least one wavelength-selecting element 152), as well as a detector 128.

[0175] As part of the corrections performed by evaluation unit 136, corrections may be made for temperature changes, including local temperature changes within light source 114, which may affect the light emission characteristics of light source 114. FIG. 3 illustrates hardware component 164 as well as the temperatures of selected components of hardware component 164. Hardware components 164 may have different or the same temperatures depending on their location, e.g., relative position and distance within spectrometer apparatus 110. In particular, as discussed above, the temperature of light emitting material 120 and the temperature of light emitting diode 118 may be mutually affected by heat transfer between light emitting diode 118 and light emitting material 120, either by thermal radiation or thermal conduction, or both. Thus, in particular, the temperature of light emitting diode 118 (hereinafter "T pn ) and the temperature of the luminescent material 120 (hereinafter referred to as 「 T Ph 3, the temperature of the LED 118 is indicated by reference numeral 168, the temperature of the luminescent material 120 is indicated by reference numeral 170, and the temperature of the detector 128 (T D (also referred to as the "internal interface") is designated by reference numeral 172.

[0176] The LED 118 may emit the primary light when an electrical current flows through the LED 118, for example, as a result of the driving unit 138 applying an appropriate voltage to the LED 118 to generate a constant electrical current (e.g., a predetermined electrical current). For example, as shown in FIG. 3, the driving unit 138 may receive a target signal S t may be provided by reference numeral 174. The target signal S t 174 is a predetermined current value to be provided through the LED 118, which may be generated, for example, by applying an appropriate voltage. The predetermined current value may be in the range of 10 mA to 500 mA, more particularly in the range of 100 mA to 300 mA, for example 50 mA. Thus, a predetermined current may be known to generate a predetermined light output (e.g., blue primary light) of the LED 118. The LED 118 is maintained at a temperature "T" indicated by reference numeral 168. pn The blue primary light may be converted by the luminescent material 120 into secondary light (e.g., light in the infrared spectral range). The luminescent material 120 may be at a temperature "T ph ". The illumination light 116 generated by the light source 114 may include the primary light or a portion thereof, the secondary light or a portion thereof, or a mixture thereof, and illuminates the object 112. One or more optical components 151 (e.g., one or more mirrors, lenses, wavelength-selective elements 152, or other optical components 151) may be used to guide the illumination light 116, for example, by disposing these optical components 151 in the optical path of the illumination light 116. The detection light 130 (e.g., reflected light) emitted from the object 112 may be guided to the detector 128. One or more optical elements 151 may also be used in the optical path of the detection light 130, as needed. For example, one or more wavelength-selective elements 152 (e.g., dispersive elements) may be used to split the detection light 130 into its spectral components.

[0177] As described in detail above, the detector 128 may include, for example, an array of light-sensitive elements 134. In particular, the detector 128 may be or include a pixel sensor (e.g., a CCD chip or a CMOS chip) including a plurality of pixels arranged on a chip. For example, each pixel may be configured to correspond to, e.g., be sensitive to, a predetermined spectral range. This allows the detector 128 to generate a detector signal S 1 including a plurality of detector signals, as shown by reference numeral 176 in FIG. 3 . px,i 176. Thus, each of the plurality of detector signals may correspond to an electronic signal generated by one of the plurality of pixels of the detector 128. Each of the plurality of detector signals may be given, for example, as a numerical value corresponding to the number of counts of each pixel measured during a predetermined time interval. Thus, the detector signal S px,i The index "px" indicates that signal S 176 may be a function that depends on the wavelength of the detected light 130. px,i 176 may also be a function of time, as indicated by the index "i", such as in the case of a time-dependent detector signal.

[0178] Detector signal S px,i The multiple signals that make up 176 may be generated simultaneously or in a time-sequential manner. px,i 176 can be determined using readout electronics 178 as shown in FIG. px,i 176 may be processed, for example, as part of pre-processing or as part of a further processing step. For example, the pixels included in detector 128 generate an electronic detector signal S px,i 176, and the electronic detector signal S px,i 176 is amplified, for example, as part of a pre-processing process before further processing, which may be performed by one or more of the software components 166.

[0179] The signal S generated by the detector 128 px,i 176 also refers to the "frame signal Spx,i 176”. As shown in FIG. 3, the signal S px,i 176 to one of the software components 166. Specifically, the detector signal S px,i A software component 166 configured to process and / or correct 176 is 、 The software may include at least one first software 180 (hereinafter also referred to as "software 1") and at least one second software 182 (hereinafter also referred to as "software 2"). The first software 180 is configured to generate a detector signal S px,i 176, which may be configured to perform at least one first processing step 184 (hereinafter also referred to as "Process 1"), which may involve, for example, px,i 176. In particular, the first processing step 184 may include correction of at least one transient or time-dependent effect. For example, the first processing step 184 may include one or more of the following: correction of dark current; correction of dark current drift; correction of fluctuation effects; correction of the photodetector response at individual detector elements or at individual time steps; correction of changes in the photodetector response due to environmental factors (e.g., temperature); extraction of information for subsequent processing; addition or multiplication with a parameter generated from information about at least one electrically measurable quantity (particularly forward voltage) or device temperature. The first software 180 may be configured to perform at least one additional step on the detector signal, including at least one fast Fourier transform 186. Thus, the detector signal S px,i 176 is subjected to a first processing step 184 and / or a fast Fourier transform 186 to obtain a time-independent signal S px 188 (the so-called "pixel signal S px 188") can be generated. Specifically, a frame signal S px,i The time dependence of 176 is removed by one or more steps constituting the first software component 1, while the wavelength dependence is removed by one or more steps constituting the first software component 1, as indicated by the index "pn". 、 signal Spx 3 shows the signal S px 188 to the second software 182. The second software 182 receives the signal S px 188, may be configured to perform at least one second processing step 190 (so-called "Process 2"), which is specifically performed on the signal S px 188 and applying at least one algorithm to generate at least one correction signal S px, corr 191. In particular, the second processing step 190 may include one or more of the following: correction of the dark current signal; correction of dark current drift; correction of fluctuation effects; correction of the photodetector response at individual detector elements or individual time steps; correction of changes in the photodetector response due to environmental factors (e.g., temperature); extraction of information for subsequent processing; operations including addition or multiplication with at least one parameter (e.g., a parameter generated from information about at least one electrically measurable quantity, in particular the forward voltage or the device temperature). In particular, the corrected signal S px, corr 191 can include a plurality of corrected signals (e.g., a plurality of corrected electronic signals), each of which can specifically correspond to a corrected count number for a corresponding pixel.

[0180] The spectroscopic device 110 includes at least one evaluation unit 136 for evaluating at least one detector signal generated by the detector 128 and deriving spectroscopic information of the object 112 from the detector signal. The evaluation unit 136 is configured to take into account information about at least one electrically measurable quantity, in particular the forward voltage, when deriving the spectroscopic information from the detector signal. The evaluation unit 136 may be configured by software programming to evaluate and / or process the detector signal, in particular as part of a first processing step 184 of at least one first software 180. The evaluation unit 136 may be particularly configured to determine at least one correction from the information item about the at least one electrically measurable quantity, in particular the forward voltage, and may further be configured to correct the at least one detector signal using the correction. Thus, the evaluation unit 136 determines the signal S px 188 can be processed and corrected 、 signal S px, i, corr It is good to generate 、 This signal may be further processed, for example by applying a fast Fourier transform 186 .

[0181] The light-emitting diode 118 and the luminescent material 120 may be based on different materials and / or different compositions of materials, which may generally affect the spectrum 192 of the phosphor LED 122, for example, as described in detail above. However, the spectrum 192 or spectral characteristics of a particular phosphor LED 122 may change with temperature, even when operating at a particular preset current. These changes may include a shift in the emission peak 193, a broadening or narrowing of the spectrum 192, an increase or decrease in the amount of light emitted, etc. In many cases, the emission at certain wavelengths is affected more than the emission at other wavelengths. This effect is illustrated in the diagram shown in FIG. 4, which shows an overlay of the spectrum 192 of the infrared emission of the phosphor LED 122 at various temperatures. Specifically, the diagram in FIG. 4 shows wavelength 198 in nanometers on the x-axis 200 and power spectral density (PDS) 194 in microwatts per nanometer (μW / nm) on the y-axis 196 as a function of wavelength 198. In the illustrated spectrum 192, the temperature of the phosphor LED 122 generating the illumination light 116 ranges from 25°C to 50°C. Typically, there is a specific center wavelength within spectrum 192 that is independent of temperature changes. Therefore, each wavelength has its own temperature coefficient for increasing or decreasing power output. Therefore, as is evident from FIG. 4, the shape of spectrum 192 changes with temperature. To more clearly visualize this effect, four specific wavelength ranges across spectrum 192 are shown in FIG. 4, each centered around one of the four specific wavelengths. The wavelength ranges are delimited by dashed lines. Specifically, the following four wavelengths and their corresponding intervals are marked with the following reference symbols: 1643 nm, reference symbol 202; 1750 nm, reference symbol 204; 1802 nm, reference symbol 206; and 1950 nm, reference symbol 208. For each of these wavelengths, the normalized change in luminous power relative to the change in luminous power at 25°C is shown as a function of temperature in the temperature range of 25°C to 50°C in the diagram of FIG. 5. In FIG. 5, the percentage change in luminous power relative to the change in luminous power at 25° C. is shown on the y-axis 196 at 219 and temperature (° C.) is shown on the x-axis 200 at 220 .The line in Figure 5 shows the fitted curve 236. As is evident from Figure 5, the luminous output at the central wavelength of 1802 nm may vary little (i.e., the change in luminous output is zero or close to zero) within the observed temperature range, whereas at other wavelengths (e.g., 1643 nm and 1953 nm), the change in luminous output may be significantly different.

[0182] For a particular current to flow through the light-emitting diode 118 (e.g., a particular, predefined value of electrical current obtained by applying a forward voltage to the light-emitting diode 118), the appropriate forward voltage may be a function of the temperature of the light-emitting diode 118. Thus, for the same current applied to the light-emitting diode 118, the forward voltage of the light-emitting diode 118 typically decreases as the temperature increases. Each type of light-emitting diode 118 has a characteristic curve of the forward voltage versus temperature. Typically, the forward voltage of the light-emitting diode 118 decreases linearly with increasing temperature, e.g., 1·10 -4 ~1·10 -3 The temperature varies with a slope in the range of V / K. Figure 6 illustrates this relationship for a particular LED 118. Specifically, Figure 6 plots the temperature of the LED 118 on the horizontal axis and the forward voltage applied to the LED 118 on the vertical axis when a DC current of 150 mA is applied to the LED 118. The forward voltage (in volts) is represented by reference character 224 on the y-axis 196. The temperature (in degrees Celsius) is represented by reference character 220 on the x-axis 200. As can be seen from Figure 6, in this case the forward voltage decreases linearly with increasing temperature. The curve in Figure 6 can be expressed by the following equation:

number

[0183] where U frepresents forward voltage, and T represents temperature. In Figure 6, measurement points 221 are represented by gray filled circles, and a dashed line corresponding to the fitted curve 236 given above is displayed. Instead of the equation or curve relating forward voltage to temperature as illustratively described above, the relationship between temperature and another electrically measurable quantity required to drive light source 114 can also be used, such as input power, current, resistance, inductance, capacitance, etc.

[0184] In this way, at least one electrically measurable quantity, in particular the forward voltage, can be used as a correction parameter to perform individual temperature corrections of the spectrum 192 at different wavelengths. 、 Detector signal S px,i The spectroscopic information can be derived by individually correcting the detector signals of the plurality of detectors 131 and combining the individually corrected detector signals. As described above, the individual corrections can be performed using the light sensitive element array 134, where each light sensitive element can be configured to generate at least one detector signal, and each detector signal can be individually corrected using at least one electrically measurable quantity, in particular a forward voltage, as a correction parameter. Finally, the corrected detector signals can be combined to derive the spectroscopic information.

[0185] To derive spectroscopic information, in particular the spectrum, of the object 112, the spectroscopic device 110, and in particular the evaluation unit 136, may take into particular account the properties of the luminescent material 120 used in the light source 114. As explained in detail above, the luminescent material 120 may be configured to absorb primary photons generated by the light emitting diode 118, which in response emits secondary photons either immediately or after a delayed or decay time. The signal or luminescence after switching off the forward current of the phosphor LED 122 can be described using equations (1) and (2) explained above.

[0186] Therefore, a particularly characteristic property of the luminescent material 120 is the decay constant τ , which represents the typical time for the afterglow of the luminescent material 120. d228 and the growth constant τ, which represents the typical time until the converted light emission reaches saturation. g The time constant τ d and τ g is typically different between different phosphor LEDs 122 and / or different types of phosphor materials 120. Furthermore, the decay constant τ d and the growth constant τ g may depend on wavelength. These time constants are usually extracted from the step response of the optical signal due to the application / cutoff of a forward current. Figures 7A and 7B show spectra 192 of two different phosphor LEDs 122 emitting light in the near-infrared region. Specifically, these are graphs plotting wavelength (nm) on the horizontal axis and power spectral density on the vertical axis. As is clear from Figures 7A and 7B, the spectra 192 of the two different phosphor LEDs 122 are different. For example, the spectrum 192 shown in Figure 7B shows high emission in the wavelength range of 1850 nm to 1950 nm, while the phosphor LED 122 having the spectrum 192 shown in Figure 7A has negligible emission in this wavelength range. The decay constant τ of the phosphor LED 122 having the spectrum shown in Figure 7A is d and the growth constant τ g are shown as a function of wavelength in Figures 8A and 8B, respectively. The decay constant τ of the phosphor LED 122 having the spectrum shown in Figure 7B d and the growth constant τ g is shown as a function of wavelength in Figures 9A and 9B, respectively. Specifically, Figures 8A and 9A each show the attenuation constant τ d 8B and 9B show the growth constant τ g The wavelength (in ms) is plotted on the y-axis 196 as reference symbol 230, and the wavelength (in nm) is plotted on the x-axis 200. Data points for different replicate measurements are marked with different shades of grey.

[0187] Another characteristic of an LED 118 is its light output power versus forward current. Generally, increasing the forward current (particularly the input current) increases the power emitted by the LED 118. The light output curve (e.g., slope) is a characteristic unique to each individual LED 118. FIG. 10 shows an example of such a curve. Specifically, the diagram of FIG. 10 shows the normalized light output 232 of a phosphor LED 122 as a function of the positive current 234, given in amperes.

[0188] 11 is a flow chart illustrating an embodiment of a method for obtaining spectroscopic information of an object 112 using a spectroscopic device 110. In particular, the method may use a spectroscopic device 110 of the present invention based on the embodiment described with reference to FIG. 1 and / or other embodiments disclosed herein. Accordingly, reference is made to the description of FIG. 1 for a detailed description of the spectroscopic device 110 used in the method.

[0189] The method may perform the following steps in a given order, although different orders are possible. In particular, one, more, 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, parallel, or combined fashion where appropriate. The method may also include additional method steps not listed.

[0190] The method includes the following steps: a. electrically driving the light source 114 using a driving unit 138 (denoted by reference numeral 238); b. (indicated by reference numeral 240) illuminating the object 112 with illumination light 116 generated by the light source 114; c. detecting the detected light 130 from the object 112 using the detector 128 (denoted by reference numeral 242) and generating at least one detector signal; d. generating at least one information of an electrically measurable quantity required to drive the light source 114 using at least one multi-channel readout integrated circuit 139 (designated by reference numeral 244), each channel of the multi-channel readout integrated circuit 139 comprising at least one buffered direct injection (BDI) circuit 141, the BDI circuit 141 configured for readout of the detector signal, the BDI circuit 141 configured to generate at least one information of the electrically measurable quantity required to drive the light source 114, the multi-channel readout integrated circuit 139 including at least one multi-channel readout application specific integrated circuit (ASIC) 142 configured to synchronously sample the detector signal and the information of the electrically measurable quantity required to drive the light source 114; and e. Evaluating at least one detector signal generated by the detector 128 (denoted by reference numeral 246) using the evaluation unit 136 and deriving spectroscopic information of the object 112 from the detector signal, taking into account information about the electrically measurable quantities required to drive the light source 114.

[0191] In particular, as shown in FIG. 11, steps c. and d. may be performed with suitable timing overlapping, in particular so as to be performed in parallel.

[0192] Further, in step e., information about the electrically measurable quantities necessary to drive the light source 114 may be used to determine at least one correction, and at least one detector signal may be corrected using the correction. The correction may include, in particular, at least one temperature correction. The temperature correction may depend at least in part on information about the electrically measurable quantities necessary to drive the light source 114. The correction may include multiplying the at least one detector signal by at least one correction factor. The corrected detector signal may be used to derive spectroscopic information.

[0193] 12A-12D illustrate different embodiments of exemplary channels of ROIC 139. In particular, Figures 12A and 12B illustrate exemplary embodiments of channels of multi-channel readout integrated circuit 139 configured for readout of detector signals, while Figures 12C and 12D illustrate exemplary embodiments of channels of multi-channel readout integrated circuit 139 configured to generate electrically measurable quantities of information necessary to drive light source 114.

[0194] 12A, an exemplary channel of a multi-channel readout integrated circuit 139 includes a buffered direct injection circuit 141. The buffered direct injection circuit 141 is coupled to a bias voltage V Bias By applying a voltage across the detector 128, the voltage across the detector 128 can be kept constant. The current due to the applied voltage can be removed by current skimming, thereby eliminating the signal offset. Thus, as shown in FIG. 12A , the ROIC 139 (specifically the multi-channel read-only integrated circuit 142) can include at least one skimming circuit 248 for current skimming the current in the detector 128. Changes in the detector resistance due to illumination cause an increase in current flow, which can be digitized by an analog-to-digital converter (ADC) 250 with relatively high time and voltage resolution.

[0195] 12B, the skimming circuit 248 may include at least one programmable current sink 252 that includes multiple transistors (not shown), which may be of the same size and configured in parallel or in a size-doubled series configuration.

[0196] As mentioned above, FIG. 12C illustrates an exemplary channel of the multi-channel readout integrated circuit 139 configured to generate an electrically measurable quantity of information necessary to drive the light source 114. In this example, the light source 114 includes an LED 118. As shown in FIG. 12C, the spectrometer device 110 can further include at least one resistor 254 electrically connecting the light source 114 and the multi-channel readout integrated circuit 139. Specifically, in this case, the resistor 254 electrically connects the anode of the LED 118 and the ROIC 139. Furthermore, in this example, the resistor 254 may have a resistance value of R=2 MΩ.

[0197] Additionally, as shown in FIG. 12D , the spectroscopic device 110 can also include at least one shunt resistor 256. In this example, as shown in FIG. 12D , the spectroscopic device 110 can include at least two resistors 254. Each end of the shunt resistor 256 can be electrically connected to the multi-channel readout integrated circuit 139 via one of the resistors 254. This can allow both the voltage drop across the shunt resistor 256 and the current through the light source 114 to be measured. The shunt resistor 256 can have a resistance value R=1 Ω, for example, and the resistor 254 connecting the shunt resistor 256 to the ROIC 139 can have a resistance value R=1 MΩ. In the example of FIGS. 12C and 12D , the resistor 254 and / or the shunt resistor 256 can have a temperature coefficient of less than 1000 ppm / K, specifically less than 100 ppm / K, more specifically less than 50 ppm / K, and even more specifically less than 10 ppm / K.

[0198] 13 is a diagram illustrating the current-voltage characteristics of a light emitting diode (LED) 118. Specifically, this diagram shows the current 258 in the LED 118 as a function of voltage 260. As can be seen in FIG. 13, the current 258 in the LED 118 is driven by a constant current I setAdjusting the LED 118 current to maintain a constant power output level, specifically the LED 118, minimizes voltage variations within the selected current range. For example, the LED 118 current 258 can be selected to provide a temperature-dependent forward voltage of 2.7 V to 2.9 V for the LED 118. The ROIC 139 may set the input voltage of the BDI 141 to a constant voltage of 2.6 V. Therefore, by connecting a resistor 254 (with a low temperature coefficient, as described above) between the anode of the LED 118 and the input of the ROIC 139, it is possible to accurately analyze the electrically measurable quantity required to drive the light source 114 within a region of interest of approximately 0.1 V to 0.3 V. However, other input voltages may be applicable to other light sources 114. Thus, the BDI 141 may function as an offset cancellation circuit. [Explanation of symbols]

[0199] 110 Spectrometer equipment 11 Object 114 Light source 116 Illumination 118 Light Emitting Diode 120 Luminescent Materials 121 Semiconductor Materials 122 Phosphor light-emitting diode 124 LED dies 126 Housing 128 detectors 130 Detected Light 132 Optical Detector 134 Array of light-sensitive elements 136 evaluation units 138 Drive Unit 139 Multi-channel readout integrated circuit 140 Current source 141 Buffered Direct Injection (BDI) Circuit 142 Multi-Channel Read-Only Integrated Circuit (ASIC) 144 Data Processing Device 146 Pretreatment equipment 148 Data Storage Devices 150 filter elements 151 Optical Components 152 Wavelength selection element 154 PCB 156 Ceramic Substrate 158 contact pads 160 Converter Body 162 Side Coat (Side Coating) 164 Hardware Components 166 Software Components 168 LED Temperature 170 Temperature of the luminescent material 172 Detector temperature 174 Target signal S t 176 Electronic detector signal S px,i 178 Readout Electronics 180 Software 1 182 Software 2 184 First Processing Step 186 Fast Fourier Transform 188 pixel signal S px 190 Second Processing Step 191 Signal S px, corr 192 Spectrum 193 Peak 194 microwatts per nanometer power spectral density 196 y-axis 198 wavelengths (nanometers) 200 x axis 202 1643nm 204 1750nm 206 1802nm 208 1950nm 219 Change in luminous output normalized to 25°C (expressed as a percentage) 220 Temperature (℃) 221 measurement points 224 Forward voltage (V) 226 Signal Counting 228 Attenuation constant τ d (milliseconds) 230 Growth constant (τ g ) Unit: ms 232 normalized optical output 234 Forward Current (Amperes) 236 Fitted curve 238 Electrical drive of light sources 240 Illuminating the Object 242 Generate detector signal 244 Generate the electrically measurable amount of information needed to drive the light source 246 Detector Signal Evaluation 248 Skimming Circuit 250 Analog to Digital Converter 252 Programmable Current Sink 254 resistor 256 Shunt Resistor 258 Current 260 Voltage

Claims

1. A spectroscopic device (110) for obtaining spectroscopic information of at least one object (112), comprising: i. at least one light source (114) for generating illumination light (116) to illuminate the object (112), the light source (114) including at least one electrically powered light source; ii. at least one detector (128) for detecting the detected light (130) from the object (112) and generating at least one detector signal; iii. at least one driving unit (138) for electrically driving the light source (114); iv. at least one multi-channel readout integrated circuit (139), each channel of the multi-channel readout integrated circuit (139) including at least one buffered direct injection (BDI) circuit (141), configured for readout of detector signals, the BDI circuit (141) configured to generate at least one electrically measurable quantity necessary to drive the light source (114), the multi-channel readout integrated circuit (139) including at least one multi-channel readout application-specific integrated circuit (ASIC) (142); the ASIC (142) is configured to synchronously sample the detector signal and information on an electrically measurable quantity required to drive the light source (114), where the information on the electrically measurable quantity required to drive the light source (114) includes at least one of the following: a forward voltage across the light source (114); a voltage drop across the light source (114); a current across the light source (114); an electrical input power to the light source (114); a resistance of the light source (114); and an impedance of the light source (114); and v. at least one evaluation unit (136) for evaluating at least one detector signal generated by the detector (128) and deriving spectroscopic information of the object (112) from the detector signal, the evaluation unit (136) being configured to take into account information items related to electrically measurable quantities necessary to drive the light source (114) when deriving the spectroscopic information from the detector signal, the evaluation unit (136) being configured to determine at least one correction from the information related to the at least one electrically measurable quantity, and the evaluation unit (136) being configured to correct the at least one detector signal using said correction; A spectroscopic device (110) comprising the components:

2. 10. The spectroscopic device of claim 1, wherein the light source is configured to emit light in a spectral range that includes at least a portion of the infrared spectral range.

3. 3. The spectroscopic device (110) of claim 1 or 2, wherein the light source (114) comprises at least one light source selected from the group consisting of: an incandescent lamp; a light emitting diode (LED) (118); a light emitting diode (LED) (118) and at least one luminescent material (120) for photoconverting primary light generated by the light emitting diode (118); a laser, a solid-state laser, a gas laser, a quantum cascade laser; a plasma light source; a low-pressure discharge lamp; a high-pressure discharge lamp; and an electric light source.

4. 3. The spectrometer device (110) of claim 1 or 2, wherein the multi-channel read-only integrated circuit (ASIC) (142) comprises at least one skimming circuit (248) configured for current skimming of the current in the detector (128).

5. 3. The spectroscopic device (110) of claim 1 or 2, further comprising at least one resistor (254) electrically connecting the light source (114) and the multi-channel readout integrated circuit (139).

6. 3. The spectroscopic device (110) of claim 1 or 2, further comprising at least two resistors (254) and at least one shunt resistor (256) that electrically connect the light source (114) and the multi-channel readout integrated circuit (139), each end of the shunt resistor (256) being electrically connected to the multi-channel readout integrated circuit (139) via the at least one resistor (254).

7. 6. The spectroscopic device (110) of claim 5, wherein the resistor (254) and / or the shunt resistor (256) have a temperature coefficient of less than 1000 ppm / K.

8. 3. The spectroscopic device (110) of claim 1 or 2, wherein the detector (128) comprises a plurality of light-sensitive elements, each light-sensitive element being configured to generate at least one detector signal, and the evaluation unit (136) is configured to individually take into account the electrically measurable quantity of information necessary to drive the light source (114) for each detector signal of the light-sensitive elements and necessary to combine the detector signals to derive spectroscopic information.

9. 9. The spectroscopic device (110) of claim 8, wherein the light-sensitive elements are configured to be sensitive to different spectral ranges of light from the object (112), and the spectroscopic device (110) comprises at least one wavelength-selective element (152) arranged in the optical path of the detected light (130), and the wavelength-selective element (152) is configured so that each light-sensitive element is exposed to a respective spectral range of the detected light (130) from the object (112).

10. A method for obtaining spectroscopic information of at least one object (112) using a spectroscopic device (110), comprising the steps of: a. electrically driving at least one light source (114) using at least one driving unit (138), the light source (114) comprising at least one electrically driven light source; b. illuminating the object (112) with illumination light (116) generated by a light source (114); c. generating at least one detector signal by detecting the detection light (130) from the object (112) using at least one detector (128); d. generating at least one information regarding an electrically measurable quantity required to drive the light source (114) using at least one multi-channel readout integrated circuit (139), each channel of the multi-channel readout integrated circuit (139) including at least one buffered direct injection (BDI) circuit (141), wherein the BDI circuit (141) is configured to read out the detector signal, and the BDI circuit (141) is configured to generate at least one information regarding the electrically measurable quantity required to drive the light source (114), wherein the multi-channel readout integrated circuit (139) includes at least one multi-channel readout application specific integrated circuit (ASIC) (142) configured to synchronously sample the detector signal and at least one information of an electrically measurable quantity required to drive the light source (114), wherein the information of the electrically measurable quantity required to drive the light source (114) includes at least one information selected from the group consisting of: a forward voltage at the light source (114); a voltage drop at the light source (114); a current at the light source (114); an electrical input power to the light source (114); a resistance of the light source (114); and an impedance of the light source (114); and e. evaluating at least one detector signal generated by the detector (128) using at least one evaluation unit (136) and deriving spectroscopic information of the object (112) from the detector signal, taking into account the electrically measurable quantity of information required to drive the light source (114); Including, wherein in step e) at least one correction is determined from the item of information of the electrically measurable quantity required to drive the light source (114), and further at least one detector signal is corrected using said correction.

11. The method of claim 10 , wherein the corrections include at least one temperature correction, the temperature corrections depending at least in part on information of an electrically measurable quantity required to drive the light source (114).

12. 12. The method of claim 10 or 11, wherein the corrected detector signal is used to derive spectroscopic information.

13. 12. A computer program comprising instructions, when said program is executed by a spectroscopic device (110) according to claim 1 or 2, to cause the spectroscopic device (110) to perform the method according to claim 10 or 11.

14. 12. A computer readable storage medium containing instructions that, when executed by a spectroscopic device (110) according to claim 1 or 2, cause the spectroscopic device (110) to perform the method according to claim 10 or 11.

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