DE102018128993A1 - Spectroscopy arrangement and method for spectroscopy - Google Patents

Abstract

The present invention relates to a spectroscopy device and a method for spectroscopy.
In particular, a spectroscopic device for measuring the spectral reflectance of a sample (300) is described, comprising:
- an illumination beam path (100) having a light source (10) adapted to direct the light emitted by the light source (10) to an illumination segment on the surface of the sample (300),
a detection beam path (200) configured to detect the light reflected from the illumination segment spectrally resolved,
characterized in that
- The light source (10) is constructed as an inverse spectrometer (110), wherein the light generated by a diode light source array (68) is spectrally combined to a common illumination beam.

Description

The present invention relates to a spectroscopy device and a method for spectroscopy. In particular, the invention relates to a spectroscopy arrangement for measuring the spectral reflection of a sample and to a method for measuring the spectral reflection of a sample by means of such a spectroscopy arrangement.

State of the art

A typical arrangement for measuring the spectral reflection of a sample (so-called spectral reflection measurement) according to the prior art (see. 1 ) comprises a white light source (eg, a halogen or xenon lamp) as a light source for the illumination of the sample, imaging optics each within an illumination and a detection beam path, a detecting spectrograph (also referred to as a spectrometer) and a means for evaluation. The evaluation means may in particular be an evaluation computer which reads out and evaluates the intensity values measured at the detector array of the spectrograph. Furthermore, the means for evaluation can suitably adjust the control parameters of the detector array in order to allow improved measurement performance.

Such an arrangement for measuring the spectral reflection of a sample has some disadvantages. Thus, a classic white light source has only a limited life (typically 2,000 to 10,000 hours) and has only a low energy efficiency. The spectral distribution of the light emitted by the white light source is fixed and can be adapted to the respective measuring task only with great difficulty (for example by expensive filters). In addition, an additional mechanical chopper / shutter must usually be used to suppress stray light. Furthermore, in the spectrograph, all wavelengths of the reflected light propagate simultaneously and produce undesirable stray light offsets on the pixels of the detector array (e.g., by light scattering at the diffraction grating). In particular, at the edge of the spectrum, where low intensities of the diffracted light actually to be detected are present on the pixels of the detector array, the unwanted scattered light can lead to significant error offsets. The low intensities at the edge of the spectrum are often unavoidable because the integration time of the detector array must always be adjusted to the signal maximum (often in the middle of the spectrum) in order to avoid overdriving in this region of the spectrum.

Disclosure of the invention

It is therefore an object of the present invention to provide a spectroscopy device and method for spectroscopy which overcome or at least significantly mitigate the problems encountered in the prior art. In particular, an improved spectroscopy arrangement for measuring the spectral reflection of a sample and a method for measuring the spectral reflection of a sample by means of such a spectroscopy arrangement are to be provided.

These objects are achieved by the features of claims 1 and 7. Advantageous embodiments of the invention are contained in the subclaims.

• - einen Beleuchtungsstrahlengang mit einer Lichtquelle, dazu ausgebildet, das von der Lichtquelle ausgesandte Licht auf ein Beleuchtungssegment auf der Oberfläche der Probe zu leiten,
• - einen Detektionsstrahlengang, dazu ausgebildet, das (von dem mit dem Beleuchtungsstrahlengang beleuchteten) Beleuchtungssegment (an der Oberfläche der Probe) reflektierte Licht spektral aufgelöst zu detektieren, wobei die Lichtquelle als inverses Spektrometer (sog. SpektroRadiometer, auch als SpektroRadiator bezeichnet) aufgebaut ist. Bei einem inversen Spektrometer wird das von einem Dioden-Lichtquellen-Array erzeugte Licht spektral zu einem gemeinsamen Beleuchtungsstrahl vereint. Die einzelnen Dioden des Arrays emittieren Licht dabei in unterschiedlichen Spektralbereichen.

A spectroscopy arrangement according to the invention for measuring the spectral reflection of a sample comprises:

• an illumination beam path having a light source adapted to direct the light emitted by the light source to an illumination segment on the surface of the sample,
• a detection beam path designed to detect spectrally resolved light reflected from the illumination segment illuminated by the illumination beam path (on the surface of the sample), the light source being constructed as an inverse spectrometer (so-called spectro radiometer, also referred to as a spectro radiator). In an inverse spectrometer, the light generated by a diode light source array is spectrally combined into a common illumination beam. The individual diodes of the array emit light in different spectral ranges.

This means that an array of point light sources (eg LED, sLED or LD array, ie light emitting diode, super light emitting diode or laser array) is positioned at the point where in a "normal" spectrometer the Array detector is located (see. 2 ). In the context of this description, such a light source array is referred to in short as a diode light source array. The light generated by the diode light source array in the inverse spectrometer can be spectrally combined by an optical grating to form a common illumination beam when the appropriately arranged individual diodes of the LED array emit their light in different and suitably selected spectral ranges.

The illumination beam path can have further optical elements in addition to the spectro-radiometer light source. In particular, the illumination beam path can be an optical Imaging system or a single lens for imaging. The illumination beam path may comprise an optical fiber for beam guidance. According to the invention, the illumination beam path is designed to guide the light emitted by the light source to an illumination segment on the surface of the sample. By directing the light emitted by the light source onto an illumination segment on the surface of the sample, the beam guidance of the light emitted by the light source and the mapping of the output of the light source to a single illumination segment are to be understood (in contrast to a multifocal or structured image). ,

In this case, the illumination segment can be in particular punctiform (i.e., the illumination segment is a point), linear or generally flat. A punctiform illumination segment may be a substantially circular or elliptical focal point (spot) or a correspondingly designed imaging surface (imaging out of focus). A punctiform illumination segment with a dot diameter of more than 5 μm is referred to as a flat (that is to say a flat dot or a dot-shaped area). Correspondingly, a line-shaped illumination segment with a line thickness of more than 5 μm is also referred to as flat (that is to say as a flat line or linear line). The surface extent of the illumination segment, which can be set via the imaging properties of the illumination beam path, determines the region, which can be evaluated for measuring the spectral reflection of a sample, at the surface of the sample.

The detection beam path may comprise optical elements. In particular, the detection beam path may comprise an optical imaging system or a single lens for imaging. The detection beam path may comprise an optical fiber for beam guidance. The detection beam path is designed to detect the light reflected from the illumination segment on the surface of the sample spectrally resolved. In particular, the detection beam path for spectrally resolved detection may comprise a spectrometer, configured to spectrally resolve and detect the light reflected from the illumination segment on the surface of the sample. For example, it may be a grating spectrometer, in which a spectral decomposition of incident light takes place on a diffraction grating.

A spectrometer is any type of optical arrangement which is generally adapted to detect the spectrally resolved light reflected from the illumination segment on the surface of the sample. Such an arrangement may, for example, be a combination of different optical filter elements, each with an associated detector. In combination with a spectroRadiometer according to the invention in the illumination beam path and a single detector in the detection beam path can measure the spectral reflection of the illumination segment by the wavelengths of the spectroRadiometer seriell - are controlled sequentially.

According to the invention, the light source is constructed as an inverse spectrometer. An inverse spectrometer is to be understood as meaning an optical structure in which, instead of a spectral decomposition of an incident light beam into an "ordinary" spectrometer onto an array detector (see the preceding paragraph), a spectral union of the light emitted from the diode light source array (FIG. which is at the location of the array detector in the "normal" spectrometer) each spectrally narrow-band light is emitted. This combination to an emergent light beam by means of a classical spectrometer exactly reversed beam path, for which the appropriate spectral selection and arrangement of the diodes of the diode light source array is crucial. Preferably, therefore, an inverse spectrometer is geometrically constructed substantially identical to a "normal" spectrometer, wherein only the array detector of the spectrometer is exchanged with a correspondingly structured diode light source array and the beam direction is reversed.

Preferably, an inverse spectrometer includes a diffraction grating for spectrally combining the individual beams from the diode light source array (inverse grating spectrometer), but other dispersive or diffractive elements (e.g., prism, transmission gratings, etc.) may also be used. Furthermore, it is possible to illuminate the output gap of the spectro-radiometer through a complete 2D array of corresponding diodes of suitable arrangement and emission wavelength in order to increase the light intensity. This then corresponds to an inverse hyperspectral camera.

The individual diodes of the diode light source array emit light in different, usually narrowband spectral segments whose central wavelength is referred to as the emission wavelength of the diode. In particular, their arrangement may be such that the order of the emission wavelengths in the diode light source array results in a spectral distribution of the emission which is capable of being spectrally completely united by the inverse spectrometer into an outgoing white light beam. This means the spatial arrangement of the individual diodes of the diode light source array with their different emission wavelengths corresponds to the spatial distribution of the wavelengths of the spectrum imaged by a corresponding "normal" spectrometer on an array detector. Depending on the control and spectral composition of the emission of the individual diodes of the array, the light beam emerging from the spectrograph can be, in particular, white light, generally colored light or monochromatic light (eg corresponding to the spectral profile of a single driven diode).

The white light source of a conventional spectroscopy device is thus replaced by an inverted spectrometer (inverted spectrograph), a light source called a spectro radiometer. In this case, an array of individual diode light sources, whose emission wavelengths and emission characteristics are exactly matched to the diffraction characteristics of the diffraction grating in the inverted spectrometer, can be positioned in place of the array detector in a classical grating spectrograph. As a result, color mixed "white light" preferably leaves the spectro radiometer, which can be used with spectrally selective modulation and intensity adjustment options (compared to the conventional white light source) for spectral reflectance measurements.

Advantages of the invention

A spectroscopy arrangement according to the invention has several advantages over conventional spectroscopy arrangements.

The lifetime of diode light sources is very high compared to the lifetimes of conventional white light sources. As a result, the useful life of the light source used is significantly increased and their maintenance costs are reduced. To suppress stray light, the diodes can be electronically modulated without an additional mechanical chopper / shutter, whereby very high modulation frequencies are possible. The sensitivity of the detector array in the detection beam path can also be optimally adjusted across the full width of the spectrum by adjusting the illumination spectral distribution of the spectro radiometer to the measurement task (i.e., the sample and detector properties).

Preferably, the individual diodes of the diode light source array for independent intensity control and / or for a single serial operation can each be individually controlled. The spectral distribution of the light can thus be flexibly and inexpensively adapted to the respective measuring task by suitable control of the currents through the individual diodes.

The detection beam path preferably comprises a detector configured to detect the light reflected by the illumination segment on the surface of the sample in a spectrally correlated manner in a single serial operation of the individual diodes of the diode light source array. This detector can, depending on the measurement task, from a single detection element (0D single detector), from a 1D array detector (eg 1024 pixels) or from a 2D array or area detector (eg 1024x1024 pixels of a camera detector ) consist.

A spectrally correlated detection means the temporal assignment of the measured intensity at one or more detector elements (pixels) in the detection beam path with respect to the individually driven diodes of the diode light source array (i.e., their different spectral ranges) in the spectro radiometer. In particular, this includes the temporal assignment of the measured intensity either at the single detector or for the individual detector pixels of the 1D / 2D array / camera detectors with respect to the individually driven diodes of the diode light source array (ie their different spectral ranges). to be understood in the spectro radiometer. A time allocation can be made via a means for evaluation over which the detector is correspondingly, i. for spectrally correlated detection.

In the case of a 0D single detector, a large-area spectral detection, which is robust against vibrations of the sample ("sample tumbling"), can be carried out by the abovementioned method. In the case of a 1D array detector, unwanted scattered light offsets on the pixels of a detector array in the detection beam path can be almost completely suppressed by said method within a spectrometer in the detection beam path, in particular at the edge of the spectrum, by the diodes of the array in the spectroRadiometer not at the same time, but suitably one after the other are excited to shine and then additionally in the spectrometer of the detection beam path several scatter light single spectra are recorded, which are finally combined in an evaluation, eg in a computer as a means of evaluation, to a common range of results. The same stray light suppression is applicable when a 2D-camera detector is operated in the hyperspectral mode by the output light of the spectro-radiometer is imaged by suitable optical elements in a line-shaped illumination segment on the sample and the sections of this line through a suitable imaging system in the detection beam path individual lines of the 2D camera detector (hyperspectral detection) are mapped.

With the mentioned method, in the case of 1 D-array detectors, the unwanted scattered light behavior of the respective detecting spectrograph arrangement can be completely quantified and compensated by spectral-serial illumination. For this purpose, in the sense of a measuring system self-calibration, first a 2D scattered light matrix is measured, which contains the relative scattered light transfer to all other detection pixels for each detection pixel in the case of spectrally pure illumination. By suitable modeling and well-known mathematical algorithms, a real-time numerical correction of scattered light artifacts in the spectrograph with a 1-D array detector can thus also be carried out in the later regular measuring operation with parallel white-light illumination (all diodes of the spectro-radiometer shine simultaneously). This scattered light compensation method can also be transferred to hyperspectral detection systems with a 2D camera detector, albeit with increased numerical complexity.

Preferably, a spectroscopy arrangement according to the invention comprises a means for evaluation, designed, in particular in the case of 1D and 2D array detectors, to numerically correct scattered light artefacts based on model data (eg in parallel white light illumination) and / or the control parameters of the electronic components for determine the operation of the spectroscopy arrangement, in particular the electronic components for the operation of the spectroRadiometers, and preferably such that by appropriate serial illumination stray light artifacts are minimized in 1D or 2D detector systems. A definition of control parameters of the electronic components for the operation of the spectroscopy arrangement is considered as part of the evaluation, since this definition results as the result of the evaluation of a reference measurement for scattered light behavior. In particular, the device for evaluating can also be used to set up a detector for a spectrally correlated detection.

The evaluation means may be connected via an optional signal line to the control of the electronic components for the operation of the spectroscopy device, in particular to the control of the diode light source array of the spectro-radiometer. Other electronic components for operating the spectroscopy assembly may include controlling a diffraction grating in the inverse spectrometer (e.g., rotational angle control), controlling a diffraction grating in the spectrometer (e.g., rotational angle control), or controlling the position of the sample. The signal line serves to transmit the control parameters of the electronic components for the operation of the spectroscopy arrangement determined by the means for evaluation to the latter.

In an alternative embodiment of the invention, the light emitted by the light source is transmitted through the illumination beam path onto a surface, i. a flat extended lighting segment (preferably an area with a diameter of 0.1 millimeters to several centimeters), passed to the surface of the sample. The detection beam path comprises a 2D camera, configured to spatially resolve the light reflected from the surface illuminated by the illumination beam path on the surface of the sample in a single serial operation of individual diodes of the array and to correlate the time spectrally. The light reflected from the illuminated area on the surface of the sample is imaged directly onto the 2D camera, i. before detection no spectral decomposition of the reflected light takes place. Instead, by a serial individual operation according to the invention of individual diodes of the diode light source array per wavelength or per wavelength segment (due to a spectral width of the emission of the individual diodes) in each case a lighting.

This is equivalent to full-spectral photography, because the 2D camera detector is used to record spectra almost simultaneously on all pixels (e.g., in only 0.3 seconds if 256 wavelengths in the SpectroRadiometer illuminate only 1 ms each). A suitable spectral evaluation of these spectra then provides, for each pixel, information about the subregions of the illumination segment (for example, for a local layer thickness measurement) assigned by the optical image to this camera pixel.

In this case, the temporal assignment of the intensity measured in serial, rapidly successive individual images at the individual pixels of the 2D detector in the detection beam path in relation to the individually driven diodes of the diode light source array (ie their different emission wavelengths) is referred to as spectrally correlated detection SpektroRadiometer to understand. The spatial resolution results from the fact that preferably the entire illuminated area is imaged on the surface of the sample on the 2D detector and on the geometry of this figure, an exact mapping between the individual pixels of the 2D detector and individual sub-segments of the illuminated area is possible ,

If one illuminates a surface with the spectro radiometer and maps this surface onto a suitable 2D camera, then through serial electronic control of the diodes with different emission wavelengths (ie, individually driving the diodes of the diode light source array emitting in different spectral ranges) and synchronized images with the (eg black and white) 2D camera for each pixel of the 2D camera, ie for the sub-segments of the illuminated area on the sample imaged onto the individual pixels of the 2D camera, a spectrum are recorded. Alternatively, the use of a color 2D camera may be useful to shorten the measurement time. For such RGB cameras, preferably up to three diodes in different RGB segments of the SpectroRadiometer may be lit simultaneously, so that the entire SpectroRadiometer spectrum can be scanned in up to three times shorter time. Thus, when using a SpectroRadiometer light source and suitable software also fully spectral photography and spatially resolved spectroscopy with very simple camera detectors (eg in smartphones) possible.

It is a way to record complete 2D distributions of spectra without any mechanical movement of sample or probe. The speed of this 2D measurement is not dependent on mechanical movements, but is determined solely by the electronic scanning speed of the diode light source array in the spectro radiometer and by the sensitivity or time resolution of the 2D camera. So far, spatially resolved white light reflectance measurements are mainly performed by 2D mapping (ie, scanning the sample surface) in conjunction with a spectrometer (requires mechanical motion in two axes) or as 2D white light reflectance measurement with a hyperspectral camera (requiring mechanical motion in one axis) , On the other hand, a spectroscopy arrangement according to the invention has, in particular, a reduced measuring duration and increased reliability. However, the spectroscopy arrangement according to the invention can not only be used for reflection measurements, but can also be used for all comparable spectral methods which work with white-light illumination and spectrometers (transmission measurement, color measurement, etc.).

Another aspect of the invention relates to a method for measuring the spectral reflection of a sample by means of a spectroscopy arrangement according to one of claims 1 to 6. The advantages of a method according to the invention are analogous to the described advantages of the particular embodiment of the spectroscopy. Reference is made to the procedural functional features mentioned in the description.

• - Bereitstellen einer erfindungsgemäßen Spektroskopieanordnung,
• - Beleuchten der Oberfläche einer Probe (d.h. eines Beleuchtungssegments) mit dem Beleuchtungsstrahlengang und spektral aufgelöste Detektion des (vom Beleuchtungssegment) an der Oberfläche der Probe reflektierten Lichtes (über den Detektionsstrahlengang). Das Verfahrens basiert somit auf der Bereitstellung und Anwendung einer erfindungsgemäßen Spektroskopieanordnung, wobei die Lichtquelle als inverses Spektrometer aufgebaut ist, bei dem das von einem Dioden-Lichtquellen-Array erzeugte Licht spektral zu einem gemeinsamen Beleuchtungsstrahl vereint wird.

A method according to the invention comprises the following steps:

• Providing a spectroscopy arrangement according to the invention,
• Illuminating the surface of a sample (ie a lighting segment) with the illumination beam path and spectrally resolved detection of the light (reflected by the illumination segment) on the surface of the sample (via the detection beam path). The method is thus based on the provision and application of a spectroscopy arrangement according to the invention, wherein the light source is constructed as an inverse spectrometer, in which the light generated by a diode light source array is combined spectrally into a common illumination beam.

Preferably, the illumination is carried out on a lighting segment, preferably punctiform (point-shaped illumination segment), on the surface of the sample and the detection of the light reflected at the surface of the sample with a spectrometer.

The illumination (i.e., the corresponding illumination segment) may also be linear or generally planar. A punctiform illumination segment may be a substantially circular or elliptical focal point (spot) or a correspondingly designed imaging surface (imaging out of focus). A punctiform illumination segment with a dot diameter of more than 5 μm is referred to as a flat (that is, as a flat dot). Correspondingly, a line-shaped lighting segment with a line thickness of more than 5 μm is also referred to as flat (that is, as a flat line shape).

Preferably, the illumination is carried out on a lighting segment, preferably punctiform, on the surface of the sample, the illumination of the surface of the sample in a single serial operation of the individual diodes of the diode light source array and the detection of the light reflected on the surface of the sample spectrally correlated with a detector. A spectrally correlated detection is understood to be the temporal assignment of the measured intensity at a detector in the detection beam path in relation to the individually controlled diodes of the diode light source array (ie their different spectral ranges). In particular, the temporal assignment of the measured intensity for the individual pixels of the array detector of a spectrometer arranged in the detection beam path in relation to the individually driven diodes of the diode light source array (ie their different Spectral regions). The further comments on this can be found in the description section for the corresponding spectroscopy arrangement analogously.

Preferably, the illumination is flat (ie dot-flat or generally planar illumination segment) on the surface of the sample, illuminating the surface of the sample in a single serial operation of the individual diodes of the diode light source array and the detection of the reflected on the surface of the sample Light spatially resolved and spectrally correlated with a 2D camera. The light reflected from the surface illuminated by the illumination beam path on the surface of the sample is imaged directly onto the 2D camera, i. before detection no spectral decomposition of the reflected light takes place. Instead, in each case one illumination takes place by the individual serial operation according to the invention of individual diodes of the diode light source array per spectral range. The further comments on this can be found in the description section for the corresponding spectroscopy arrangement analogously.

Another aspect of the invention relates to a spectroscopic device for measuring the spectral reflectance of a sample, comprising an illumination beam path with a light source adapted to direct the light emitted by the light source to a point on the sample surface, a detection beam path, adapted to that of the With the illumination beam path illuminated point on the sample surface reflected light to detect spectrally resolved, wherein the light source is constructed as an inverse spectrometer, in which the light generated by an LED array or LD array is combined spectrally to a common illumination beam, wherein the individual diodes of the array emit light in different spectral ranges.

Advantageous developments of the invention are specified in the subclaims and described in the description.

list of figures

• 1 eine schematische Darstellung einer Spektroskopieanordnung gemäß dem Stand der Technik,
• 2 eine schematische Darstellung einer ersten Ausführungsform einer erfindungsgemäßen Spektroskopieanordnung, und
• 3 eine schematische Darstellung einer zweiten Ausführungsform einer erfindungsgemäßen Spektroskopieanordnung.

Embodiments of the invention will be explained in more detail with reference to the drawings and the description below. Show it:

• 1 a schematic representation of a spectroscopy according to the prior art,
• 2 a schematic representation of a first embodiment of a spectroscopy arrangement according to the invention, and
• 3 a schematic representation of a second embodiment of a spectroscopy arrangement according to the invention.

Embodiments of the invention

1 shows a schematic representation of a spectroscopy according to the prior art. The spectroscopy arrangement comprises an illumination beam path 100 with a light source 10 , designed to be that of the light source 10 emitted light to a point on the surface of the sample 300 to lead. For this purpose, the illustration shown has a first appearance 20 on, which may be in particular a lens system or a single lens.

Furthermore, the spectroscopy arrangement comprises a detection beam path 200 , adapted to detect the light reflected from the point spectrally resolved. The illustration shown has a second optic 30 on, which may be in particular a lens system or a single lens. Furthermore, the figure shows a spectrometer 210 in the detection beam path 200 , In the spectrometer 210 is first through an aperture 40 incident background light hidden. That through the aperture 40 incident light is then transmitted through a first mirror 42 on a diffraction grating 44 deflected and spectrally dissected there. The spectrally decomposed light is then connected via a second mirror 46 to an array detector 48 diverted. At this it will be on the surface of the sample 300 reflected light detected spectrally resolved. The from the array detector 48 measured intensity values are then evaluated by a means 50 , eg a measuring computer with appropriate evaluation software, evaluated. The construction shown is an example of a variety of different spectrometer types. What is essential is that of the with the illumination beam path 100 illuminated point on the surface of the sample 300 reflected light is detected spectrally resolved.

2 shows a schematic representation of a first embodiment of a spectroscopy arrangement according to the invention. The illustration corresponds in essential parts to the illustration in FIG 1 , the reference numerals and their assignment therefore apply accordingly. In contrast to the representation in 1 became the light source 10 in the illumination beam path 100 according to the invention by an inverted spectrometer 110 (also known as SpectroRadiometer) replaced. Preferably, the inverse spectrometer 110 Radiotechnically as substantially identical to the spectrometer 210 in the detection beam path 200 formed, wherein only the array detector 48 of the spectrometer 210 with a correspondingly structured diode light source array 68 is exchanged and the beam direction is reversed. That of the diode light source array 68 emitted light is transmitted through a second mirror 66 on a diffraction grating 64 redirected and there spectrally united. The spectrally combined light is then connected via a first mirror 62 in the direction of a panel 60 diverted. At the aperture 60 background light is hidden. The means of evaluation 50 can via an optional signal line 52 with the control of the electronic components for the operation of the spectroscopy device, in particular with the control of the diode light source array 68 be connected. Other electronic components for the operation of the spectroscopy arrangement may include the control of the diffraction grating 64 in the inverse spectrometer 110 (eg rotation angle control), the control of the diffraction grating 44 in the spectrometer 210 (eg rotation angle control) or the control of the position of the sample 300 include. The signal line 52 serves the purpose of evaluation by the means 50 specified control parameters of the electronic components for the operation of the spectroscopy to this.

3 shows a schematic representation of a second embodiment of a spectroscopy arrangement according to the invention. The illustration corresponds in essential parts to the illustration in FIG 2 , the reference numerals and their assignment therefore apply accordingly. In contrast to the representation in 2 became the spectrometer 210 in the detection beam path 200 through a 2D camera 70 replaced. Furthermore, the illumination of the sample is flat, ie punctiform-flat, linear-flat or generally flat. Preferably takes place in the detection beam path 200 a picture of this area on the 2D camera 70 , For spectroscopy, the light reflected from the surface in a single serial operation of individual diodes of the diode light source array 68 spatially resolved and spectrally correlated with the 2D camera 70 detected.

LIST OF REFERENCE NUMBERS

10

light source

20

first optics (illumination beam path)

30

second optics (detection beam path)

40

cover

42

first mirror

44

diffraction grating

46

second mirror

48

Array detector

50

Means for evaluation

52

signal line

60

cover

62

first mirror

64

diffraction grating

66

second mirror

68

Diode light source array

70

2D camera

100

Illumination beam path

110

inverse spectrometer ("SpectroRadiometer")

200

Detection beam path

210

spectrometer

300

sample

Claims (10)

A spectroscopic device for measuring the spectral reflectance of a sample (300), comprising: - an illumination beam path (100) with a light source (10) adapted to project the light emitted by the light source (10) onto an illumination segment on the surface of the sample (300) a detection beam path (200), designed to detect the light reflected from the illumination segment in a spectrally resolved manner, characterized in that - the light source (10) is constructed as an inverse spectrometer (110) in which the light emitted by a diode Light source array (68) light is spectrally combined into a common illumination beam. Spectroscopy arrangement according to Claim 1 , wherein the individual diodes of the diode light source array (68) for independent intensity control and / or for a single serial operation can each be controlled individually. Spectroscopy arrangement according to Claim 1 or 2 wherein the spectroscopy arrangement further comprises a means for evaluation (50), adapted to perform a numerical correction of scattered light artifacts based on model data and / or set the control parameters of the electronic components for the operation of the spectroscopy. A spectroscope assembly according to any one of the preceding claims, wherein the detection beam path (200) comprises a spectrometer (210) adapted to that of the illumination segment to spectrally resolve and detect reflected light. Spectroscopy arrangement according to one of the preceding claims, wherein the detection beam path (200) comprises a detector (48), adapted to detect the spectrally correlated by the illumination segment in a single serial operation of the individual diodes of the diode light source array (68). Spectroscopy arrangement according to one of the preceding claims, wherein the light emitted by the light source (110) is guided through the illumination beam path (100) onto a surface on the surface of the sample (300), and the detection beam path (200) is guided by a 2D camera (70). comprises, configured to spatially resolved and spectrally correlated to detect the light reflected from the surface in a single serial operation of individual diodes of the diode light source array (68). Method for spectroscopy, comprising the following steps: Providing a spectroscopy arrangement according to one of the preceding claims, Illuminating the surface of a sample (300) with the illumination beam path (100) and spectrally resolved detection of the light reflected at the surface of the sample (300). Method according to Claim 7 , wherein the illumination takes place on a lighting segment and the detection of the reflected light with a spectrometer (210). Method according to Claim 7 , Wherein the illumination takes place on a lighting segment, the lighting is carried out in a single serial operation of the individual diodes of the diode light source array (68) and the detection of the reflected light is spectrally correlated with a detector (48). Method according to Claim 7 , Wherein the illumination is flat, the illumination is carried out in a single serial operation of the individual diodes of the diode light source array (68) and the detection of the reflected light with a 2D camera (70) spatially resolved and spectrally correlated takes place.

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