WO2021004984A1

WO2021004984A1 - Reflector device for an optical analyser and method for operating a reflector device

Info

Publication number: WO2021004984A1
Application number: PCT/EP2020/068935
Authority: WO
Inventors: Andreas Merz; Martin HUSNIK; Eugen BAUMGART; Maximilian Busch
Original assignee: Robert Bosch Gmbh
Priority date: 2019-07-11
Filing date: 2020-07-06
Publication date: 2021-01-14
Also published as: DE102019210253A1

Abstract

The present invention relates to a reflector device (1) for an optical analyser comprising: at least one light source (3); a detector device (4); and a housing (G) with at least one light source mounting (3a), in which the light source (3) is arranged and with a detector mounting (4a), in which the detector device (4) is arranged, wherein the housing (G) further comprises a planar base region (BB) and a side wall region (SB), which comprises material reflecting the light (3b) emitted by the light source (3), wherein the side wall region (SB) extends in a direction away from the base region (BB) and in a light beam emission direction (F) of the light source (3) and at least in areas describes at least one ellipse around the base region (BB), in the first focal point (BP1) of which the light source mounting (3a) is arranged and in the second focal point (BP2) of which the detector mounting (4a) is arranged.

Description

description

title

Reflector device for an optical analysis device and method for

Operation of a reflector device

The present invention relates to a reflector device for an optical analysis device and a method for operating a reflector device for analyzing a sample.

State of the art

Illumination reflectors can be used to radiate light in a broad visible or infrared wavelength range onto a sample, which light can be reflected back or scattered by this sample after an interaction to a detector and contains spectral information about the sample through absorption during the interaction with the sample .

Usual lighting reflectors have a light source with a

Emission area towards the sample and a detection area with a

specific field of view. The radiation area of the light source, i.e. one

Illumination direction, the sample can irradiate in a certain area. However, since the light source and the detector device should be spatially separated from one another, the illumination area and the field of view of the detector can usually only partially overlap. In order to make this overlap as large as possible, a certain distance between the illumination reflector and the sample is usually necessary, which can allow for scattered light from the surroundings in the illumination area. Conventional illuminating reflectors can have a parabolic basic shape in order to collimate light in the direction of the sample. In most cases, collimation can only be achieved when the reflector is 20 times the size of the light source, which is limited

Installation space situations with microspectrometers can be limited. Usual minimum distances between sample and housing, at which a

Illumination spot with an intensity maximum can arise directly in the field of view of the detector, can usually be about 10 mm.

In EP 1508795 Al an absorption spectrometer with a

wavelength dispersive element described. A wavelength-dependent deflection can deflect light of different wavelengths onto different areas of a detector and analyze the light.

Disclosure of the invention

The present invention provides a reflector device for an optical analysis device according to claim 1 and a method for operating a reflector device for analyzing a sample according to claim 15.

Preferred further developments are the subject of the subclaims.

Advantages of the invention

The idea on which the present invention is based consists in specifying a reflector device for an optical analysis device, with which a sample can be illuminated and one from the sample

reflected light can be collected at a detector socket. The reflector device is characterized by a more targeted and thus improved illumination of the sample in that area which can be detected by the detector mount. As a result, a spacing of the illumination area and the detection area on the sample can be reduced or avoided.

According to the invention comprises a reflector device for an optical

Analysis device at least one light source; a detector means; and a housing with at least one light source holder in which the light source is arranged and with a detector holder in which the detector device is arranged, wherein the housing further comprises a planar bottom area and a side wall area, which comprises a material that is reflective for a light emitted by the light source, the side wall area extending in a direction away from the bottom area and in a light emission direction of the light source and its side walls at least regionally Describe an ellipse around the floor area, in whose first focal point the light source holder and in whose second focal point the detector holder is arranged.

The detector device can comprise an optical sensor, for example to generate a spectrum, that is to say, for example, to determine intensities over the wavelength. The detector mount can advantageously represent an optical aperture to the illumination area on the sample.

The light source can be light in a broad range of visible or infrared

Emit wavelength range. The light can interact with the materials of the sample and enter as reflected and / or scattered light

Have absorption spectrum, which can be evaluated by the detector device and by any further evaluation device of an analysis device. Consequently, a material composition of the sample can be determined.

The planar floor area can define a front side of the reflector device and face the sample when it is placed on it or when it approaches it.

The side walls of the side wall area can connect directly to the bottom area and at least in some areas vertical inner walls of the

Comprise side wall portions which can extend vertically from the bottom portion. The elliptical shape of the vertical inner walls of the side wall area can act as a reflector for the light emitted by the light source and is advantageously visible on that front side from the direction of the sample. The light from the light source can partly be radiated directly onto the sample and partly also hit the vertical inner walls, from which it can be emitted with the same angle of incidence and reflection regarding its vertical and horizontal component can be reflected. The light is directed towards the sample in the vertical direction towards the bottom area and the elliptical shape focuses the light advantageously in the second focal point in the horizontal direction. Since the light source can be located vertically offset with respect to the inner walls, a component of the emitted light can thus be vertical in one direction, i.e. perpendicular to the

Bottom area on which the sample is irradiated and the horizontal component is focussed at or around the second focal point of the ellipse. As a result, the emitted light can be concentrated on a region of the sample above the second focal point which can coincide with the field of view of the detector device. The planar bottom area can thus lie essentially parallel to the surface of the sample. Through such a lateral light guide, that is to say the reflection on the elliptical walls, and through the additional vertical component, the sample can therefore be irradiated more intensively in the field of view of the detector device and a distance between the

Housing, advantageously an end face of the housing towards the sample, can be reduced and the housing can advantageously be arranged close to the sample or resting directly on it. A distance between the sample and the housing (the top of which can correspond to an end face) can be reduced from the usual 10 mm to about 2 mm or less.

The planar floor area can also comprise a reflective material. The light source holder and detector holder can comprise a structure, a holder, a shaft, a mounting base, a recess or others in order to arrange, fix or mount the light source and detector device therein.

The housing can be manufactured inexpensively and easily, for example with an injection molding process. The reflector device can be milled, for example, from injection molded parts or from solid material, advantageously from reflective coated or embossed parts. The coating material can comprise gold, silver or aluminum. Furthermore, a protective layer can be applied to the coating in order to protect the coating material from oxidation. According to a preferred embodiment of the reflector device, the side wall area extends in a direction perpendicularly away from the base area and in a light emission direction of the light source.

According to a preferred embodiment of the reflector device, the side wall area extends in a direction deviating from a perpendicular direction to the bottom area away from the latter and in one direction

Light emission direction of the light source, the at least regionally elliptical shape of the side walls varying with a distance above the floor area.

The values of the major (a) and minor semiaxis (b) of the ellipse in each plane above the floor area can vary along the height of the side wall, advantageously in such a way that the side wall differs from a perpendicular

Alignment to the floor area may vary. For example, the major semi-axis a can be replaced by a linear relationship, i.e. approximately a = m * SB-h + aO with the height SB-h of the side wall above the floor area and a slope m, approximately in the range between 0.25 to 1, and a basic value for the semi-major axis aO of the ellipse at the bottom. As the distance between the height of the side wall and the floor area increases, the length of the major semi-axis a can increase or decrease. By transforming the equation, one obtains the expression for the minor semi-axis according to b ² = (m * SB-h + aO) ² - e ² . The position e of the light source to the center of the ellipse can remain constant, the ellipse itself can then become larger and larger with increasing distance and approaches a circle asymptotically.

In every plane parallel to the floor area, the side walls can be described by an elliptical equation with constant e (eccentricity), whereby the focusing property of the reflector can be retained in every plane parallel to the floor area. Bevelling the side walls can bring advantages in terms of production, for example with a diamond milling head. The course of the semi-axes is not limited to a linear relationship but can also form a quadratic or any other mathematical relationship that can produce a non-undercut shape, for example. According to a preferred embodiment of the reflector device, the side wall area has a planar top side on a side facing away from the bottom area, on which a transparent cover is arranged that spans the bottom area, and wherein the planar top side is parallel to a plane of the planar bottom area.

The planar top side can form the end face of the housing, be parallel to the planar bottom area and be placed on the sample or at least face it.

According to a preferred embodiment of the reflector device, the housing is shaped as a TO housing from an underside facing away from the planar bottom area and the side wall area.

The TO housing (transistor oriented) can comprise a material that reflects the emitted light, for example a metal, or it can comprise a reflective coating on the bottom area and the inner walls of the side wall area. The TO housing can also have a base and / or conductor connections for the light source and the detector and / or others

Have connections for a measurement signal.

According to a preferred embodiment of the reflector device, the light source comprises a thermal light bulb or an LED.

An infrared light source can also be used.

According to a preferred embodiment of the reflector device is partially on the planar floor area and laterally around the

Detector mount around a frustoconical elevation is formed, which rises in the light emission direction above the planar bottom area and at most up to a planar top side of the side wall area.

According to a preferred embodiment of the reflector device there is a rotationally symmetrical recess in the frustoconical elevation introduced, which describes an ellipsoid of revolution about an axis of rotation, in whose first focal point the light source is located and in whose second focal point there is an intersection of the rotational axis with a normal through the detector socket.

According to a preferred embodiment of the reflector device, the point of intersection is located at a cutting height above a planar top side of the side wall region.

According to a preferred embodiment of the reflector device, the frustoconical elevation comprises a conical recess laterally around the

Detector socket around which has an opening towards the planar bottom area and comprises side walls on which an absorbent

Coating is applied

According to a preferred embodiment of the reflector device, the light source has a reflective coating on its upper side and / or the cover has the reflective coating in some areas in an area above the light source.

The light source can, for example, have a dome with the metallization on the top (in the direction of radiation), advantageously simple in the case of a light bulb.

The reflective coating can comprise a metallization.

According to a preferred embodiment of the reflector device, it comprises two or more light source sockets, each with a light source, one of the light source sockets and the detector socket being arranged in the first and second focal point of a respective ellipse, the ellipses partially overlapping around the detector socket.

According to a preferred embodiment of the reflector device, the cover comprises a cylindrical recess above the detector mount, in which a protective glass is inserted, through which a normal by means of light refraction through the detector socket, along which light from a sample enters the

Detector mount can be irradiated, is displaceable parallel to this normal.

According to the invention, an optical analysis device comprises a

reflector device according to the invention and furthermore an evaluation device which is set up to evaluate a measurement signal from the detector device.

The optical analysis device can advantageously be designed as a spectrometer, for example as a miniaturized or microspectrometer, the evaluation device and the detector device being set up to generate a spectrum of the detected light from the sample. The measurement signal processed by the evaluation device can, for example, be compared with known data records and the sample can be identified and its materials determined, for example by means of chemometric methods.

According to the invention, the method for operating a

Reflector device for analyzing a sample providing a reflector device according to the invention; placing the reflector device on the sample in such a way that the detector mount and the base area with the light source mount face the specimen and a region of the sample to be analyzed is above the detector mount or above a

The radiation area of the detector socket is located; illuminating the sample with the light source; detecting a light reflected from the sample by the detector device and generating a spectrum; and evaluating the spectrum by an evaluation device and determining a material present in the sample.

According to a preferred embodiment of the method, the housing is placed directly on the sample.

The housing can be placed directly on the sample, so as to

To reduce or even avoid motion artifacts and to be able to better or completely shield ambient light from the area of the sample to be irradiated and analyzed. According to a preferred embodiment of the method, the housing is arranged at a distance above the sample.

The procedure may also be through the in conjunction with the

Characteristic features mentioned reflector device and their advantages and vice versa.

Further features and advantages of embodiments of the invention emerge from the following description with reference to the accompanying drawings.

Brief description of the drawings

The present invention is explained in more detail below with reference to the exemplary embodiments specified in the schematic figures of the drawing.

Show it:

1a-c schematic side views of the reflector device according to an embodiment of the present invention;

2a-b show a schematic top view of the reflector device from FIG. 1;

3 shows a schematic plan view of the reflector device according to a further exemplary embodiment of the present invention;

4 shows a schematic side view of an optical analysis device with the reflector device according to the exemplary embodiment in FIG. 3;

5 shows a schematic side view of the reflector device according to a further exemplary embodiment of the present invention; 6a-b schematic top views of the reflector device according to further exemplary embodiments of the present invention;

7 shows a block diagram of method steps of a method for operating a reflector device for analyzing a sample according to an exemplary embodiment of the present invention;

8 shows a plan view of a side wall area of a reflector device according to a further exemplary embodiment of the present invention; and

9 shows a plan view of a side wall area of a reflector device according to a further exemplary embodiment of the present invention.

In the figures, the same reference symbols denote identical or functionally identical elements.

1a-c show schematic side views of the reflector device according to an embodiment of the present invention.

The figures la, lb and lc all show the same design

Reflector device 1, but from different perspectives

Directions of view.

The reflector device 1 for an optical analysis device comprises at least one light source 3; a detector device 4; and

a housing G with at least one light source holder 3a, in which the light source 3 is arranged, and with a detector holder 4a, in which the detector device 4 is arranged, the housing G further comprising a planar bottom area BB and a side wall area SB, which for one of the Light source 3 emitted light-reflecting material, wherein the side wall area SB extends in one direction, approximately perpendicular, away from the bottom area BB and in a light emission direction F of the light source 3 and whose side walls at least partially describe at least one ellipse around the bottom area BB, in the first Focus the Light source holder 3a and in whose second focal point the detector holder 4a is arranged.

The housing G can be formed as a TO housing from an underside facing away from the planar bottom area BB and the side wall area SB. The light source 3 can comprise a thermal light bulb or an LED.

On the planar floor area BB and laterally around the detector mount 4a, a frustoconical elevation D can be formed, which rises in the light emission direction F above the planar floor area BB and at most up to a planar top side SB1 of the side wall area SB. Here, the planar top side SB1 of the side wall area SB can have a constant height above the bottom area BB in all areas and serve as a flat support surface (front side) of the housing G.

The frustoconical elevation D can correspond to a cone, the central axis of which can correspond to a normal through the detector socket. That part of the bottom region BB which rests directly on the light source mount 3a is preferably planar, in other words it extends

frustoconical elevation D not up to the light source holder 3a. Through the frustoconical elevation D, light which leaves the light source mount can partially impinge on the frustoconical elevation D and be radiated vertically in the direction of the sample, so that less light from the light source can get into the detector mount. The frustoconical elevation D can advantageously be used when a cover rests on the planar upper side SB1, that is to say from this a part of the light from the light source can be scattered back to the floor area. By using the frustoconical elevation D, direct incidence of light from the cover onto the detector device can be reduced or prevented.

A vertical height SB-h of the side wall area SB, advantageously the

Inner walls of the side wall area SB can for example be 3 mm.

2a-b each show a schematic top view of the reflector device from FIG. 1. In FIG. 2a, the housing G is shown opposite to the direction of emission of the light emitted by the light source and perpendicular to the floor area BB.

The frustoconical elevation D can, for example, cover almost half the planar floor area BB. The side wall area SB describes an ellipse adjacent to the bottom area BB and can describe a circular shape on the outer area.

In Fig. 2b, the elliptical geometry of the inner walls is the

Side wall area SB shown in plan view similar to FIG. 2a. The

Principal axes a (major semiaxis) and b (minor semiaxis) of the ellipse as well as the light source mount 3 in the first focal point BPI and the detector mount 4 in the second focus BP2 are shown, wherein the ellipse can have an eccentricity e. The eccentricity e can be selected depending on the application during manufacture. Since the light source mount 3a has a spatial extent, at least one center point of this or of the light source 3 can be arranged in the first focal point BPI. The relationship: e ² = a ² - b ^{2 can} apply here. The same can apply to the detector mount 4a and the light source 4. A distance I between the light source mount 3a and the detector device 4a (approximately between their centers), as shown in FIG. 2b, can be 10 mm, for example.

3 shows a schematic top view of the reflector device according to a further exemplary embodiment of the present invention.

The plan view relates to a sample in accordance with FIGS. 2a and 2b.

The reflector device 1 here comprises two light source sockets 3a1 and 3a2, it also being possible for several to be possible, each with one light source. Here, a first light source mount 3al and the first light source can be arranged in the first focal point and the detector mount 4a in the second focal point of a first ellipse. The second light source and second

Light source mount 3a2 can be in a first focal point of a second ellipse and the same detector device 4 in the second focal point of the second ellipse be arranged, that is to say several ellipses share a detector device and the second focal point, wherein the ellipses can partially overlap around the detector mount 4a. With the detector mount, the two light sources can form an isosceles triangle with an opening angle at the detector mount of, for example, 30 °. Depending on the application, the opening angle can also be up to 180 ° (Fig. 6a).

A rotationally symmetrical recess ELI (EL2) can be made in the frustoconical elevation D, which can describe an ellipsoid of revolution around an axis of rotation, in whose first focal point the light source 3 (3-1, 3-2) can be and in whose second focal point an intersection of the axis of rotation (RAI, RA2) with a normal ND through the detector mount 4a can be located. For several ellipses in the floor area (partial areas BB1 and BB2 are shown), the frustoconical elevation D can have its own from each light source holder

have rotationally symmetrical recess ELI (EL2), wherein the axes of rotation can meet at the intersection. The exemplary

Dimensions can be Dl = 12 mm, D2 = 33 mm and D3 = 30 mm, where Dl can be the height of the isosceles triangle between the light source and detector mounts, D2 can be an outer width and D3 an outer length of the housing.

In addition to the two recesses of the ellipsoids of revolution, further such recesses (as ellipsoids of revolution) can be present, for example forming so-called N-ellipses.

FIG. 4 shows a schematic side view of an optical analysis device with a reflector device according to the exemplary embodiment in FIG. 3.

FIG. 4 shows an embodiment of the reflector device from FIG. 3, which can be included in an optical analysis device 2. The optical analysis device 2 can comprise an evaluation device AE, which is set up to evaluate a measurement signal from the detector device 4. The gradient of the axis of rotation RA can determine a distance 10 by which a sample (the sample 20 is not shown for reasons of clarity) can be spaced from the end face, that is to say the upper side of the side wall region SB1. This distance is important because the elliptical effect concentrates the light from the light sources in the second focal point of the ellipsoid of revolution EL, in addition to the ellipses of the side wall area. The

ellipsoidal recesses can therefore have their own

Elliptical reflection on their respective second focal point the light of their light source in addition to the field of view (FOV) of the common

Direct the detector device onto the sample. In the first focal point of the

The light source can be located here in ellipsoids of revolution (which can be described by the recess). A minor major axis of the

Ellipsoids of revolution can for example be 2 mm or depending on

Application vary. After that, a reflected light can enter the

Detector device 4 are irradiated. This can also increase the proportion of light on the sample and reduce the proportion of scattered light not reflected on the sample on the detector. The light sources can emit different or the same wavelength ranges. The slopes of all ellipsoids are advantageously the same if the elliptical dimensions are the same. The ellipsoids can also have different sizes, the point of intersection 9 always at the second focal point of the respective

Ellipsoids of revolution should lie. The ellipsoids of revolution can thus have the reflection effect of the inner walls of the associated elliptical region of the

Reinforce the side wall area. Due to the reflective effect of the

Ellipsoids of revolution can achieve an additional increase in the illumination intensity of the sample over the field of view of the detector device by up to 50% compared to a known reflector without elliptical shapes. The surfaces of the rotary recesses can therefore also be reflective. The optical analysis device 2 can be designed as a miniaturized spectrometer. The distance 10 can be, for example, 3.5 mm

(Working distance) or vary. The distance 10 can for example also be 2 mm or 3 mm or similar, depending on the orientation of the

Axis of rotation RA, an intensity of the illumination on the sample can decrease significantly with increasing deviation from intersection point 9, since a high degree of Light concentration at the point of intersection 9, that is to say at the distance 10, can be achieved.

The recesses with the ellipsoids of revolution can furthermore increase the stability of the detected measurement signal from the sample

backscattered (reflected) light with respect to small displacements of the sample or the reflector device (sensor system), which can result from slight movements of a manual measurement, for example. The reason for this is that when the reflector device moves relative to the sample, an illumination area moves in the field of view of the detector and can move out of it. It can also be the size of the

Change the illumination area on the sample with the distance (distance 10 in FIG. 4) to the sample. With a more focused and therefore smaller one

The system can become less sensitive to the lighting area, since the area of the distance variation in which the lighting area grows or wanders out of the field of view can also become larger. Should he

The lighting area can be enlarged or more diffuse

Ellipsoids of revolution also have facets. As a result, a continuously rounded shape of the ellipsoid can be discretized and approximated by a large number of small, adjacent square or rectangular planar surfaces.

5 shows a schematic side view of the reflector device according to a further exemplary embodiment of the present invention.

The embodiment of FIG. 5 differs from that of FIG. 3 in that it has a cover glass 5, with a transparent cover 5 also being able to be placed on the end face SB1 of the housing in FIG. 3. The cover 5 over the detector mount 4a can comprise a cylindrical recess ZA, in which a protective glass 12 can be inserted, through which means

Refraction of light by a normal ND through the detector mount 4a, along which light from a sample can be radiated into the detector mount 4a, can be displaced parallel to this normal ND. The normal ND can be shifted laterally outward to the position of a further normal ND 'by a distance d. Due to the refraction, this can be the displacement of the second Effect and take into account the focal point on the sample and the illumination area on the sample. The distance d can be 0.7 mm, for example. The axis of rotation RA, or several axes of rotation, can be aligned with an intersection with the shifted normal ND 'and it can be assumed that the surface of the sample and the top of the protective glass 12 are in the second focal point of the ellipsoid of revolution EL (ELI, EL2) and on the further normal ND 'lie. The cover 5 can be inserted or framed in a projection in the side wall area SB and flush with the upper side SB1 on the upper side. With such a design, the housing with the cover 5 can advantageously be placed directly on the sample and measure in mechanical contact, which can improve the stability of the measurement. The protective glass 12 can be made in different thicknesses, so it can end in a planar manner with the top of the cover or be sunk in the cylindrical recess ZA.

The frustoconical elevation D can comprise a conical recess laterally around the detector mount 4a, which can have an opening towards the planar bottom area and can comprise side walls SW-KA, on which an absorbent coating 11 can be applied, which can comprise a black lacquer, for example . The recess can also be cylindrical or have a different shape.

The light source 3 can have a reflective coating (not shown) on its upper side and / or the cover 5 can have the reflective coating 6 in some areas in an area above the light source 3, whereby light from the light source can be reflected back into the cavity of the housing (more Light can be radiated sideways onto the inner walls of the side wall area and / or the ellipsoid of revolution (its recess surfaces) and the elliptical reflection effect enables a greater yield of light to be radiated onto the field of view of the detector on the sample. The height of the first focal point with the light source in one of the ellipsoids of revolution it can be, for example, 3.3 mm above an underside of the housing.

FIGS. 6a-b each show a schematic top view of the reflector device according to a further exemplary embodiment of the present invention. FIG. 6a shows an arrangement of a side wall area SB which shows the bottom area in plan view (from the direction of the light reflection from the sample) as an overlap of two ellipses. A first light source 3-1 can be arranged in a first light source holder 3al and a second light source 3-2 can be arranged in a second light source holder 3a2. The reflector device 1 can have only one detector device 4 in a detector mount 4a, with the two light source mounts and the detector mount being able to be arranged along a straight line g. The first ellipse around the first light source mount 3al can form a first floor area BB1 with the detector mount, the first light source mount 3al is located in a first focal point of the first ellipse and the detector mount 4a is located in a second focal point of the first ellipse.

The second ellipse around the second light source holder 3a2 can with the

Detector mount 4a form a second floor area BB2, the second

Light source mount 3a2 are located in a first focal point of the second ellipse and the detector mount 4a are located in a second focus of the second ellipse.

The arrangement of the ellipses in the reflector device 1 of FIG. 6b

differs from that of FIG. 6a in that the two

Light source mounts 3al and 3a2 to the detector mount 4a can lie on two different straight lines gl and g2, which with the same

Ellipse size can form an isosceles triangle. It can be possible here for the two ellipses in FIGS. 6a and 6b to each have the same dimensions or different dimensions.

The reflector device 1 can in this way (according to FIG. 6b) also be expanded to include further ellipses.

In all of the above-mentioned embodiments, the light source, the

Detector device, or a filter device can be arranged or integrated on a cover, for example a short-pass, long-pass or band-pass filter. This can, for example, be a coating on the lid include, for example directly in a field of view of the detector device, that is to say the detection aperture (not shown).

7 shows a block diagram of method steps of a method for operating a reflector device for analyzing a sample according to an exemplary embodiment of the present invention.

In the method for operating a reflector device for analyzing a sample, an inventive device is provided S1

Reflector device; a placement S2 of the reflector device on the sample, such that the detector mount and the bottom area with the

Light source holder facing the sample and an area to be analyzed of the sample is above the detector holder or above a

The radiation area of the detector socket is located; illuminating S3 the sample by the light source; detecting S4 a light reflected from the sample by the detector device and generating S5 a spectrum; and an evaluation S6 of the spectrum by an evaluation device and determination S7 of a material present in the sample.

8 shows a plan view of a side wall area of a

Reflector device according to a further embodiment of the present invention.

The side wall area from FIG. 8 shows a shape of so-called N-ellipses, it being possible for more than two focal points to be present

where Ui and v describe the focal points and x and y describe the coordinates in the plane. Such a curve for three focal points is shown in FIG. 8, wherein such a shape with n focal points can be used, in which n-1 points correspond to the positions of light sources and one point corresponds to the position of the detector mount. 8 shows an example of a 3-ellipse with 2

Light sources 3-1, 3-2 at for example -6 mm, 3.5 mm and -6 mm, -3.5 mm and a detector device 4 at, for example, 6 mm, 3.5 mm. The positions of the light source and the detection aperture correspond to those of FIG. 3.

9 shows a plan view of a side wall area of a

Reflector device according to a further embodiment of the

present invention.

In Fig. 9, an ellipse is shown with four focal points, the

Detector device 4 can be arranged in the center and four light sources 3-1, 3-2, 3-3. And 3-4 can be arranged around the outside.

Although the present invention is based on the preferred

Embodiment has been fully described above, it is not limited to it, but can be modified in many ways.

Claims

Expectations

1. Reflector device (1) for an optical analysis device comprising:

at least one light source (3);

a detector device (4); and

a housing (G) with at least one light source holder (3a) in which the light source (3) is arranged and with a detector holder (4a) in which the detector device (4) is arranged, the housing (G) also having a planar bottom area (BB) and a side wall area (SB) which comprises material reflecting for a light (3b) emitted by the light source (3), the side wall area (SB) extending in a direction away from the base area (BB) and in a light emission direction ( F) the light source (3) and whose side walls at least partially describe at least one ellipse around the bottom area (BB), in whose first focal point (BPI) the light source holder (3a) and in whose second focal point (BP2) the detector holder (4a) is arranged is.

2. reflector device (1) according to claim 1, wherein the side wall region (SB) in a direction perpendicular to the bottom region (BB) away and in a

Light emission direction (F) of the light source (3) extends.

3. reflector device (1) according to claim 1, wherein the side wall region (SB) extends in a direction deviating from a perpendicular direction to the

Floor area (BB) extending away from this and in a light emission direction (F) of the light source (3), the at least regionally elliptical shape of the side walls varying with a distance above the floor area (BB).

4. reflector device (1) according to any one of claims 1 to 3, wherein the

Side wall area (SB) has a planar top side (SB1) on a side facing away from the bottom area (BB), on which a transparent cover (5) is arranged which spans the bottom area (BB), and wherein the planar top side (SB1) is parallel to a plane of the planar floor area (BB).

5. reflector device (1) according to one of claims 1 to 4, in which the housing (G) from one of the planar bottom area (BB) and the side wall area (SB) remote bottom is formed as a TO housing.

6. reflector device (1) according to any one of claims 1 to 5, wherein the

Light source (3) comprises a thermal light bulb or an LED.

7. reflector device (1) according to any one of claims 1 to 6, in which

in areas on the planar floor area (BB) and laterally around the

Detector mount (4a) is formed around a frustoconical elevation (D) which rises in the light emission direction (F) above the planar bottom area (BB) and at most up to a planar top side (SB1) of the side wall area (SB).

8. reflector device (1) according to claim 7, in which in the frustoconical elevation (D) a rotationally symmetrical recess (EL) is introduced, which describes an ellipsoid of rotation about an axis of rotation (RA), in whose first focal point the light source (3) is located and at the second focal point there is an intersection (9) of the axis of rotation (RA) with a normal (ND) through the detector socket (4a).

9. reflector device (1) according to claim 8, wherein the point of intersection (9) is located at a cutting height (10) above a planar upper side (SB1) of the side wall region (SB).

10. reflector device (1) according to one of claims 7 to 9, wherein the

frustoconical elevation (D) comprises a conical recess laterally around the detector socket (4a), which has an opening to the planar

Has the bottom area (BB) and comprises side walls (SW-KA) on which an absorbent coating (11) is applied.

11. Reflector device (1) according to one of claims 5 to 10, as far as dependent on claim 4, in which the light source (3) has a reflective coating (6) on its upper side and / or the cover (5) in an area above the light source (3) has the reflective coating (6) in some areas.

12. reflector device (1) according to one of claims 1 to 11, which comprises two or more light source sockets (3al; 3a2; 3an) each with a light source (3-1; 3-2; ...; 3-n), wherein each one of the light source mounts (3al; 3a2; ...; 3an) and the detector mount (4a) are arranged in the first and second focal points of a respective ellipse, the ellipses partially overlapping around the detector mount (4a).

13. Reflector device (1) according to one of claims 5 to 12, as far as dependent on claim 4, in which the cover (5) over the detector socket (4a) comprises a cylindrical recess (ZA) in which a protective glass (12) is inserted , through which a normal (ND) through the detector mount (4a), along which light from a sample can be radiated into the detector mount (4a), can be displaced parallel to this normal (ND) by means of light refraction.

14. Optical analysis device (2) comprising a reflector device (1) according to one of claims 1 to 13, and further comprising an evaluation device (AE) which is set up to evaluate a measurement signal from the detector device (4).

15. A method for operating a reflector device (1) for analyzing a sample (20) comprising the steps:

Providing (Sl) a reflector device (1) according to one of claims 1 to 13;

Placing (S2) the reflector device (1) on the sample (20) in such a way that the detector mount (4a) and the floor area (BB) with the light source mount (3a) face the specimen (20) and an area to be analyzed (FOV) the sample (20) is located above the detector socket (4a) or above an irradiation area (4b) of the detector socket (4a);

Illuminating (S3) the sample (20) by the light source (3);

Detecting (S4) a light (LR) reflected from the sample (20) by the detector device (4) and generating (S5) a spectrum; and

Evaluation (S6) of the spectrum by an evaluation device and determination (S7) of a material present in the sample (20).

16. The method according to claim 15, wherein the housing (G) is placed directly on the sample (20).

17. The method according to claim 15, wherein the housing (G) is arranged at a distance (10) above the sample (20).