OPTICAL ARRANGEMENT FOR OPTOELECTRONIC REFLECTIVE MEASUREMENT AND SENSOR DEVICE

The following relates to an optical arrangement for optoelectronic reflective measurements and to a sensor device comprising such optical arrangement .

BACKGROUND

Optoelectronic refection measurements are used in a plurality of sensing applications such as optical spectroscopy and material analysis . For optical spectroscopy and material analysis in the NIR (near infrared) to MWIR (mid-infrared region) range , a filament light source/bulb is typically used for illumination . An advantage of this kind of light source is the wide band of spectra ( similar to a thermal lamp/black body spectra ) that is not possible to reali ze with LEDs or to mix with a set of LEDs . A bulb has a light emission in the whole solid angle and needs to focus on a target spot or area .

Reflective measurement typically need a homogeneous distribution of light on a target area in a limited angular range , or angle of incidence AOI , to get only di f fuse reflective light to a spectral optoelectronic sensor . Often a so called 45 ° / 0 ° or 0 ° / 45 ° geometry is employed to set up the measurements . Simple arrangements use light emitters and optoelectronic sensor and allow for large targets to be illuminated . However, such simple setups often lack in suf ficient overlap with the field of view, FOV, of the optoelectronic sensor . Additionally, there is may be a large gradient of power distribution in the FOV area of the optoelectronic sensor . This may also happen i f additional optics is used . To compensate for gradients , a second source may be used on the opposite side of the optoelectronic sensor to overlap the gradients . This can be optimi zed up to a ring light being arranged around the optoelectronic sensor, but a large number of light sources is needed to implement the ring light configuration and, as a consequence , the cost of the system increases .

Elliptical or parabolic reflective optics are state of the art for several lamps and proj ection devices . Variations in shape are able to solve various collimation or focusing requirements . There have been attempts to use such reflective optics to ef ficiently collect light on a target obj ect using filament light source/bulb . However, these solutions rely on focusing the illumination on the target . I f the target is structured or includes inhomogeneous ef fects , an integral reflectance measurement needs to be restricted over a speci fic si ze of target field . Also a setup using a slight di f fuser is recommended but this will not generate a homogenous power distribution to a restricted target illumination area . Because of absorbing a classical di f fuser will decrease the ef ficiency and that ' s why it needs new approaches .

Thus , an obj ect to be achieved is to provide an optical arrangement for optoelectronic reflective measurement that overcomes the aforementioned limitations and provides improved homogeneous illumination at the reflection target . This obj ective is achieved with the sub ect-matter of the independent claims . Further developments and embodiments are described in dependent claims .

SUMMARY OF THE DISCLOSURE

The following relates to an improved concept in the field of optical sensing, in particular optoelectronic reflective measurements , which may be used for optical spectroscopy, material analysis , etc . The proposed concept suggests the use of a light source and optoelectronic sensor, which are arranged inside a reflective optical device . The reflective optical device is modi fied in various ways to provide a highly homogenous radiance power distribution on a target field . For example , optical components are added to the reflective optical device in order to spread homogeneously the light distribution over a required field si ze . Another aspect involves splitting the reflective optical device into multiple facet areas that follow tangential the elliptical shape , for example . Each si ze of a facet may define a spread of light on the target area .

In at least one embodiment , an optical arrangement for optoelectronic reflective measurement comprises a light source for emitting light and an optoelectronic sensor for detecting said light after being reflected at an external target . The optical arrangement further comprises a reflective optical device , which comprises at least one optical reflector . The optical device has an illumination plane , which is to be coupled to the external target . The light source and the optoelectronic sensor are arranged along an optical axis inside the reflective optical device . In operation, light is emitted by the light source and reflected by the optical reflector . The reflected light illuminates the illumination plane downstream the optical axis with a homogenous radiance power distribution . Furthermore , light emitted by the light source is blocked by the optoelectronic sensor from directly reaching the illumination plane . A field of view of the optoelectronic sensor at least partially overlaps with the illumination plane to be coupled to the target .

To conduct an optoelectronic reflective measurement the external target is coupled to , or placed at , the illumination plane . Thus , the target is illuminated with the homogenous radiance power distribution provided by the optical device at the location of the illumination plane . Light provided in this way is reflected at a target area of the external target and back into the optical device . This reflected light can then be detected by the optoelectronic sensor . Finally, the light detected by the sensor provides a sensor signal , which can be analyzed for optical spectroscopy and/or material analysis , e . g . in the NIR (near infrared) to MWIR (midinfrared region) range .

The proposed optical arrangement for optoelectronic reflective measurement allows a highly homogenous target illumination, which is not limited to small surface features but rather allows for integral reflectance measurement on granular, structured or inhomogeneous targets . Moreover, the proposed approach enables a rotation symmetric angle of incidence (AOI ) on the external target obj ect . The arrangement further provides high ef ficiency, because the arrangement needs only one light source , for example a filament lamp/bulb . Furthermore , the optoelectronic sensor needs no additional FOV limiting, as undesired light is blocked from the sensor .

Hereinafter the term optical path, or beam path, relates to the traj ectory that a light ray emitted by the light source follows as it propagates through the optical device , i . e . along the optical axis . The term "homogenous" describes a similar or uni form illumination over a given area, such as a target field . For example , illumination which is constant within 10% , 5% or 1 % is considered homogenous .

In at least one embodiment , the optical device comprises a casing . The optical reflector is formed as a portion of the casing .

The casing thus enables capturing the reflected and direct light portion of the light emitted by the light source . The light source and optoelectronic sensor are arranged inside the casing, thereby providing a closed optical device , or reflector .

In at least one embodiment , the casing has an optical axis . The light source and optoelectronic sensor are arranged on and along the optical axis . The optical device essentially has circular symmetry with respect to the optical axis .

In at least one embodiment , the casing has a first wall , which closes the casing at a first side . The casing has a second wall at a second side of the casing opposite to the first side , which may close the casing except for an aperture . The casing has a third wall , which surrounds a complete area between the first wall and the second wall . The light source is arranged inside the casing and mounted to the first wall . The optical reflector is configured as a light-reflective surface of the third wall . The optoelectronic sensor is arranged inside the casing so that a front side of the optoelectronic sensor is directed towards the illumination plane .

In at least one embodiment , the third wall is formed as a portion of a spheroid or paraboloid having a first opening closed by the first wall and a second opening limited by the second wall . The light-reflective surface covering the third wall inside the casing is formed as a portion of the spheroid or paraboloid to provide reflection .

In at least one embodiment , the optical device is free of a di f fuser . This is to say that no di f fuser is needed to spread light along the optical axis to provide homogenous radiance power distribution at the illumination plane .

In at least one embodiment , a shape of the optical device is arranged to spread the light onto the illumination plane . The shape can be implemented or limited by the third wall of the casing for example . The shape may be chosen such as to move a focal point away from the illumination plane , i . e . the emitted light is not focused onto the illumination plane but rather spread out to establish the homogenous radiance power distribution at the illumination plane .

In at least one embodiment , an optical element is arranged in the beam path of the optical device to spread the light onto the illumination plane . The optical element provides optical means to alter optical paths through the optical device . Similar to the shape of the optical device the optical element moves a focal point away from the illumination plane , i . e . the emitted light is not focused onto the illumination plane but rather spread out to establish the homogenous radiance power distribution at the illumination plane .

In at least one embodiment , the optical element comprises a concave ring lens . The concave ring lens spreads the emitted light to have a homogeneously light distribution over a required field si ze of the illumination plane . The concave ring lens may have several sections which act as concave lenses . This has the further advantage that the optoelectronic sensor may be integrated, or mounted, into the concave ring lens , which besides its optical ef fect serves as a means to hold the optoelectronic sensor in place .

In at least one embodiment , the optical element comprises a convex ring lens . For example , the convex ring lens can be implemented as a glass plate with several sections which act as convex lenses . Each of these sections collects light in two di f ferent focal spots , which all lie outside the illumination plane . Beams leaving the convex ring lens , or the sections of the convex ring lens , point towards the illumination plane , which is located downstream the lens . After passing the focal spots , the light spreads out again and homogenously illuminates the illumination plane .

In at least one embodiment , the optical element comprises a lens plate , in particular, a Fresnel lens or wave form ring lens . The lens plate spreads the emitted light to have a homogeneously light distribution over a required field si ze of the illumination plane . The lens plate may resemble any wave form, which spreads out the emitted light to have a homogeneously light distribution . This can be determined by means of optical design software. The optoelectronic sensor may be integrated, or mounted, into the plate, which besides its optical effect serves as a means to hold the optoelectronic sensor in place.

In at least one embodiment, the optical reflector comprises mirror sections. Each mirror section has a linear or nonshape and follows along the shape of the optical device. Mirrors are not affected by chromatic aberration.

In at least one embodiment, facet sizes of the mirror sections change their size along the optical axis symmetrically or asymmetrically. The facet sizes are changing symmetrically from left to right with respect to a center and optical axis of the optical device. The change may be implemented by smaller facet sizes towards the left and right, and bigger size towards the center, or vice versa. However, the facet sizes are changing asymmetrically from left to right with respect to the center and optical axis. The change may be implemented by smaller sizes towards the left, and bigger size towards the right, or vice versa. However, the facet sizes are changing asymmetrically from left to right with respect to the center and optical axis. The change may be implemented by smaller sizes towards the left, and bigger size towards the right, or vice versa.

In at least one embodiment, the optical arrangement further comprising a supporting device having a supporting area for supporting the target object. The supporting device is connected to the optical device, e.g. at the second wall.

The supporting device enables the collection of diffuse reflective light reflected from a target object supported in the supporting area of the supporting device on the photosensitive area of the optoelectronic sensor . The configuration reali zes a roughly circular 45 ° / 0 ° or 0 ° / 45 ° measurement geometry .

An embodiment of a sensor device comprising an optical arrangement for optoelectronic reflective measurement according to one of the embodiments explained above is speci fied in claim 15 . The sensor device may be configured, for example for optical spectroscopy or material analysis in the NIR to MWIR range .

Further embodiments of the sensor device become apparent to the skilled reader from the aforementioned embodiments of the optoelectronic device , and vice-versa .

The following description of figures may further illustrate and explain aspects of the optoelectronic device and the sensor device . Components and parts of the devices that are functionally identical or have an identical ef fect are denoted by identical reference symbols . Identical or ef fectively identical components and parts might be described only with respect to the figures where they occur first .

Their description is not necessarily repeated in successive figures .

In the figures :

Figure 1 shows an example embodiment of an optical arrangement for optoelectronic reflective measurement , Figure 2 shows another example embodiment of an optical arrangement for optoelectronic reflective measurement ,

Figure 3 shows an example embodiment of an optical arrangement for optoelectronic reflective measurement with a concave ring lens ,

Figure 4 shows an example embodiment of the optical arrangement with a convex ring lens ,

Figure 5 shows an example embodiment of the optical arrangement with a Fresnel lens or wave form ring lens ,

Figure 6 shows an example embodiment of the optical arrangement with a faceted reflector,

Figure 7 shows another example embodiment of the optical arrangement with a faceted reflector,

Figure 8 shows another example embodiment of the optical arrangement with a faceted reflector, and

Figure 9 shows an example embodiment of a sensor device .

DETAILED DESCRIPTION

In the following, a number of embodiments of an optical arrangement for optoelectronic reflective measurement will be described with reference to Figures 1 to 8 . Basically, the embodiments share a similar design, which will be discussed in general terms first . Structurally di f ferent features between the embodiments will be highlighted in the context of the Figures .

The designs employ a reflective optical device 30 which is arranged for collecting light of a light source 10 onto a target obj ect to be mounted on a supporting area 61 of a supporting device 60 . The collected light illuminates a illumination plane 32 at which the target obj ect can be mounted via the supporting area 61 and is reflected of f the target back into the optical device . An optoelectronic sensor 20 is arranged inside the optical device 30 in order to collect and detect the light reflected by the target obj ect .

The light source 10 may be implemented as a wide angular emission light source , for example a filament lamp or bulb source . An advantage of this light source for illuminating the target obj ect is the wide band of wavelengths similar to a thermal lamp or black body spectra . The optoelectronic sensor 20 comprises a semiconductor photodetector, such as individual photodiodes or an array of photo-elements , e . g . a CMOS photodetector or charge coupled device . The optoelectronic sensor typically is sensitive within the wide band provided by the light source . However, the optoelectronic sensor may also be implemented as a spectral sensor to provide spectrally resolved reflectance measurements . The light source and the optoelectronic sensor are arranged along an optical axis 33 inside the reflective optical device 30 . The target obj ect may be aligned with or centered on the optical axis , when mounted to the support surface 61 .

The optical device 30 comprises a casing 50 . The optical reflector 31 is formed as a portion of the casing 50 . The casing 50 has a first wall 51 closing the casing at a first side , and a second wall 52 closing the casing 50 at a second side opposite to the first side . The light source 10 is arranged inside the casing and mounted to the first wall 51 . A supporting device 60 is mounted to the second wall 52 of the casing 50 . For example , the supporting device 60 is mounted to the second wall 52 of the casing 50 such that a supporting area 61 for supporting the target obj ect is located in an aperture of the second wall 52 .

The casing 50 has a third wall 53 surrounding a complete area between the first wall 51 and the second wall 52 . The optical reflector 31 is configured as a light-reflective surface of the third wall 53 . The light-reflective surface forms an inner surface of the casing 50 . The third wall 53 may be formed as a portion of a spheroid having a first opening closed by the first wall 51 and a second opening closed by the second wall 52 . This is to say that also the light- reflective surface covering the third wall inside the casing 50 is formed as a portion of the spheroid to provide reflection . The spherical or parabolic form may resemble an ellipse or parabola, for example . As will be discussed in further detail below, the form may also comprise faceted mirrors . The optical axis 33 forms an axis of symmetry, so that the optical device 30 essentially has circular symmetry .

The optical device 30 , by way of the light-reflective surface 31 of the third wall 53 , and its geometrical shape , defines an illumination plane 32 . With the light source 10 mounted to the first wall 51 light emitted by the light source and reflected by the optical reflector 31 illuminates the illumination plane 32 downstream the optical axis with a homogenous radiance power distribution . The illumination plane 32 may be located inside or outside the casing 50 , i . e . before or after the second wall 52 ( along the optical axis 32 ) . Preferably, the target obj ect is arranged at the illumination plane 32 to conduct a reflectance measurement . It may be noted that light is not focused on the illumination plane 32 . In fact , a focus may be located inside or outside the casing, i . e . before or after the second wall 52 ( as seen along the optical axis 33 ) .

The optoelectronic sensor 20 is arranged inside the casing 50 so that a front side 21 of the optoelectronic sensor 20 is directed towards the supporting area 61 of supporting device 60 . A back side 22 of the optoelectronic sensor 20 is directed towards the light source 10 . The front side 21 of the optoelectronic sensor 20 comprises a photosensitive area 23 .

The back side 22 of the optoelectronic sensor 20 obstructs an angular range of optical paths along the optical axis . As a consequence , light emitted by the light source 10 is blocked by the optoelectronic sensor 20 from directly reaching the illumination plane . Unobstructed rays of light emitted by the light source 10 are reflected by the optical reflector 31 towards the illumination plane 32 downstream the optical axis 33 . As a consequence , the light source 10 illuminates the illumination plane 32 with a homogenous radiance power distribution . With such a configuration, a large part of emission is able to homogenously illuminate a target area on the target obj ect .

For a reflectance measurement , the target obj ect is mounted to the supporting area 61 . A field of view of the optoelectronic sensor 20 at least partially overlaps with the illumination plane 32 . Thus , light which is reflected back along the optical axis 33 may strike the photosensitive area 23 and can be detected by the optoelectronic sensor 20 .

According to a possible embodiment , the back side 22 of the optoelectronic sensor 20 may be configured as a lightabsorbing printed circuit board (not shown) . This configuration allows direct rays emitted from light source 20 towards supporting area 61 to be ef ficiently absorbed by the light-absorbing PCB of the optoelectronic sensor and reduce unwanted reflections of f of the back side 22 .

The angular spread, or obstruction, in the incidence on the illumination area can be defined by the si ze of the back side of the optoelectronic sensor 20 , for example an absorbing PCB, and the position of the optoelectronic sensor 20 between light source 10 and supporting area 61 /target obj ect .

The proposed concept allows for a high degree of homogeni zation of target illumination of a highly ef ficient optical setup for optoelectronic reflective measurement that uses geometrically shaped reflective optic for collecting light of a light source such as filament lamp (wide angular emission source ) to a target and having a optoelectronic sensor inbetween the target and the light source , thus implementing a highly homogenous target illumination with a rotation symmetric AOI ( angle of incidence ) .

The optical arrangements suggested herein only need a single light source , for example a filament lamp or bulb with a solid angle of 90 ° , for example a one-side mirrored bulb for illuminating the target obj ect mounted to the supporting area 61 of the supporting device 60 . Moreover, the optoelectronic sensor 20 needs no additional FOV limiting elements or diffusers. The proposed concept thus allows light emitted by a single light source, for example only one filament lamp or bulb, to be collected in a highly efficient way, i.e. up to 90%, to an illumination plane coupled to a target object, e.g. having a circular homogenous angular distribution of the reflected light in the plane.

The homogenous illumination of the illumination plane 32 can be affected by spreading out the light emitted by light source using several optical means, or combinations thereof. For example, the spread in a defined way over a required field size can be done in specific setup solutions:

• optical elements instead of diffuser ring for defined spread, including radial lens (e.g., concave or convex) , special radial wave form (e.g., cosine) shape, Fresnel lens (critical because of two light orientations (direct from source and from reflector)

• adjust shape of reflector to more or less parabolic,

• non ideal reflector surface (e.g., roughening of mirror surface) to spread by a desired bit.

Figure 1 shows an example embodiment of an optical arrangement for optoelectronic reflective measurement. The drawing indicates an elliptical reflection optic, i.e. the third wall 53 of the casing 50 is formed as a spheroid. The casing has a first opening closed by the first wall 51 and a second opening closed or limited by the second wall 52. The reflective surface 31 covering the third wall inside the casing 50 is formed as a portion of the spheroid to provide reflection . The light source 10 is located in the first focus of the spheroid . The second focus of the spheroid does not coincide with the illumination plane 32 . In fact , along the optical axis 33 the second focus lies upstream the illumination plane , e . g . outside the casing 50 . The illumination plane is homogenously illuminated as a consequence of the shape of the spheroid . In a certain sense , the elliptical reflector is adj usted to have a more flat shape .

Figure 2 shows another example embodiment of an optical arrangement for optoelectronic reflective measurement . Similar to Figure 1 the shape of the spheroid can be adj usted so that the second focus of the spheroid does not coincide with the illumination plane 32 but is shi fted inside the casing 50 . In fact , along the optical axis 33 the second focus lies upstream the illumination plane . The illumination plane is homogenously illuminated as a consequence of the shape of the spheroid . In other words , the elliptical reflector is adj usted to have a bowl-like shape .

Figure 3 shows an example embodiment of an optical arrangement for optoelectronic reflective measurement with a concave ring lens 34 . The concave ring lens spreads the emitted light to have a homogeneously light distribution over a required field si ze of the illumination plane 32 . The concave ring lens can be implemented as a glass plate , similar to catadioptric telescopes or similar optical devices . The plate may have several sections which act as concave lenses . This has the further advantage that the optoelectronic sensor 20 may be integrated, or mounted, into the plate , which besides its optical ef fect serves as a means to hold the optoelectronic sensor 20 in place . The concave ring lens can be arranged in the sensor plane , for example . Figure 4 shows an example embodiment of the optical arrangement with a convex ring lens . A convex ring lens 35 can be used instead of a concave ring lens . In this example , the convex ring lens defines a number of focal spots , which all lie inside the casing 50 . For example , the convex ring lens can be implemented as a glass plate with several sections which act as convex lenses . Each of these sections collects light in two di f ferent focal spots . For example , light which is collected in the first focal spot is reflected by means of the reflector 31 after passing a corresponding section or convex lens . Light which is collected in the second focal spot is not reflected by means of the reflector but rather propagates directly downstream the optical axis 33 after passing a corresponding section or convex lens . The beams leaving the convex ring lens , or the sections of the convex ring lens , point towards the illumination plane 32 , which is located downstream the lens at wall 52 . After passing the focal spots , the light spreads out again and homogenously illuminates the illumination plane .

Figure 5 shows an example embodiment of the optical arrangement with a lens plate , e . g . a Fresnel lens or wave form ring lens . The lens plate 36 spreads the emitted light to have a homogeneously light distribution over a required field si ze of the illumination plane . The lens plate can be implemented as a glass plate . The plate may have several sections of a Fresnel lens . The sections may also resemble any wave form, which spreads out the emitted light to have a homogeneously light distribution . This can be determined by means of optical design software . The optoelectronic sensor 20 may be integrated, or mounted, into the plate , which besides its optical ef fect , serves as a means to hold the optoelectronic sensor in place . The lens plate can be arranged in the sensor plane , for example .

Alternatively, or in addition, the optical device can be faceted in multiple mirror sections 37 . The closed elliptical or parabolic reflector, or optical device , essentially is split into multiple facet areas that follows tangential the shape of the third wall 53 . Each si ze of a facet defines the spread of the light on the target area . The shaped mirror sections may follow the elliptical or parabolic shape of the third wall 53 of the casing 50 and adapting the facet si ze of individual mirror sections to the target area si ze . Furthermore , the mirror sections may have a linear or nonlinear shape . Variations in shape are able to solve various collimation or focusing requirements . Faceted parabolic optics with various shape can be open reflector system with a maximum 50% length of a ellipse . However, a non closed system includes a signi ficant portion of direct light to the target that is not part of the reflection .

Figure 6 shows an example embodiment of the optical arrangement with a faceted reflector . The drawing shows several mirror sections 37 which are arranged along the third wall 53 . Each mirror section has a linear shape and follow along the elliptical or parabolic shape of the third wall 53 of the casing 50 . The drawing also shows corresponding beam paths of light emitted by the light source 10 . The individual mirror sections are arranged so that they reflect incident light towards the illumination plane . The si ze of the mirror section, or facet si ze , is adapted to the desired si ze of target area to be illuminated . In this example , the facet si zes is smaller towards the first and second walls 51 , 52 and bigger towards and at the center . The facet si ze is one structural parameter which can be changes in order to af fect the desired si ze of target area to be illuminated and a degree of homogeneous illumination .

Figure 7 shows another example embodiment of the optical arrangement with a faceted reflector . The design is similar to that of Figure 6 . The facet si zes are changing symmetrically from left to right with respect to the center and optical axis , i . e . from the first wall , along the third wall 52 towards the second wall along the optical axis . The change may be implemented by smaller si zes towards the left and right , and bigger si ze towards the center, or vice versa .

Figure 8 shows another example embodiment of the optical arrangement with a faceted reflector . This embodiment is based on the one in Figure 6 . However, the facet si zes are changing asymmetrically from left to right with respect to the center and optical axis . The change may be implemented by smaller si zes towards the left , and bigger si ze towards the right , or vice versa .

In further embodiments (not shown) a variation of circular facet width can depend on the orientation of the filament in the bulb . Furthermore , the mirror sections may be Hexagon base geometry to get more circular distribution . Also , the mirror sections may have non-linear shape to better follow along the elliptical or parabolic shape of the third wall 53 of the casing 50 .

Figure 9 shows a sensor device 100 comprising an optical arrangement for optoelectronic reflective measurement , according to one of the embodiments as illustrated in one of Figures 1 to 8 . The sensor device 100 may be configured for optical spectroscopy and material analysis , for example , in the NIR to the MWIR range . The sensor device 100 allows reflective measurement with a homogenous light distribution in a limited angular range (AOI ) to get only di f fuse reflective light to a spectral optoelectronic sensor of the optical arrangement .

While this speci fication contains many speci fics , these should not be construed as limitations on the scope of the invention or of what may be claimed, but rather as descriptions of features speci fic to particular embodiments of the invention . Certain features that are described in this speci fication in the context of separate embodiments can also be implemented in combination in a single embodiment . Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination . Moreover, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a sub-combination or variation of a sub-combination .

Similarly, while operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results . In certain circumstances , multitasking and parallel processing may be advantageous . Features recited in separate dependent claims may be advantageously combined . Moreover, reference signs used in the claims are not limited to be construed as limiting the scope of the claims .

Furthermore , as used herein, the term "comprising" does not exclude other elements . In addition, as used herein, the article "a" is intended to include one or more than one component or element , and is not limited to be construed as meaning only one .

This patent application claims the priority of the German patent application 102022115052 . 6 , the disclosure content of which is hereby incorporated by reference .

References

1 optical arrangement

10 light source

20 optoelectronic sensor

40 optoelectronic sensor

21 front side

22 back side

23 photosensitive area

24 light-absorbing printed circuit board

30 optical device

31 optical reflector

32 illumination plane

33 optical axis

34 concave ring lens

35 convex ring lens

36 lens plate

50 casing

51 wall

52 wall

53 wall

54 aperture

60 supporting device

61 supporting area

100 sensor device