DE102021202164B3 - Tandem diaphragm architecture for increasing the filling factor of compact multi-channel imaging systems - Google Patents

Abstract

Multi-channel imaging system (10, 10'), having the following features: an image sensor (12); and at least one first channel (10_1), which has a lens system (14) with an aperture stop (14) and a tandem stop structure (16), and at least one second channel (10_2) with a further lens system with an aperture stop (14) and a further tandem stop structure ( 16); wherein the aperture diaphragm (14) is designed to image light in the direction of incidence (10e) from different spatial directions onto the image sensor (12), wherein the tandem diaphragm structure (16) and the further tandem diaphragm structure (16) each have a first diaphragm (16a), which in the direction of incidence (10e) is seen upstream of the aperture stop (14), and each has a second stop (16b), which is arranged between the aperture stop (14) and the image sensor (12).

Description

• ■ Alle abbildenden Multikanalabbildungssysteme, bei denen mehrere einzelne Bilder auf einem gemeinsamen Bildsensor (zusammenhängendes 2D-Pixelarray) abgebildet werden, benötigen mehrere Blendenlagen, um die Abbildung auf definierte Bildflächen zu begrenzen. Um kein Übersprechen der einzelnen Bildkanäle zu gewährleisten, ist die Abnahme der relativen Helligkeit bei Anschluss des Nachbarkanals auf 0 designet. Prinzipiell lassen sich flächig dicht gepackte Anordnungen (rund, rechteckig, dreieckig, hexagonal, ...) realisieren.
• ■ Die Abgrenzung der Einzelbildkanäle zur Verhinderung von Überlagerungen benachbarter Bildkreise durch eine physische Barriere in einem Multikanalabbildungssystem führt zu einer starken Vignettierung für die Randbereiche eines Bildkanals. Die Vignettierung erfordert das Absenken der relativen Helligkeit eines Kanals für den maximalen Feldwinkel des Systems unter 0,2.

Embodiments of the present invention relate to a multi-channel imaging system. Preferred exemplary embodiments relate to a tandem diaphragm architecture for increasing the fill factor of compact multi-channel imaging systems.

• ■ All imaging multi-channel imaging systems, in which several individual images are imaged on a common image sensor (connected 2D pixel array), require multiple aperture positions in order to limit imaging to defined image areas. In order to ensure no crosstalk between the individual image channels, the reduction in relative brightness is designed to be 0 when the adjacent channel is connected. In principle, densely packed arrangements (round, rectangular, triangular, hexagonal, ...) can be realized.
• ■ The delimitation of the individual image channels to prevent overlapping of adjacent image circles by a physical barrier in a multi-channel imaging system leads to strong vignetting for the edge areas of an image channel. Vignetting requires lowering the relative brightness of a channel below 0.2 for the maximum field angle of the system.

1. 1. Bei allen Abbildungssystemen mit Zwischenbild-Abbildung kann eine echte Feldblende in die Zwischenbildebene eingebracht werden, wie zum Beispiel bei klassischen Lichtfeldkameras (vgl. Raytrix oder das Fraunhofer Ultra-Flach-Mikroskop/Facet Vision).
2. 2. Eine 3D-Baffle-Struktur zwischen Optik und Sensor kann eingebracht werden, wobei der Füllfaktor hier entsprechend limitiert ist, z. B. durch das Deckglas vor dem Sensor oder die Strukturgröße des Baffle-Arrays, Aspektverhältnis von Stegbreite zu Öffnung und Dicke (zwischen Linsen und Deckglas/Sensor) kann technologisch nicht beliebig groß gewählt werden, um Fertigbarkeit zu erhalten. Eine Anwendung für Multispektralelemente beziehungsweise eine Multiaperturkamera ist in [1] gezeigt.
3. 3. Ferner kann ein dünnes Baffle-Grid in der Bildsensorebene verwendet werden, wie es beispielsweise in der US 9 202 833 B2 gezeigt ist. Das ist technologisch sehr aufwendig herzustellen. Ferner muss die Absorption nicht zwangsläufig gewährleistet sein, da Stege sehr dünn, z. B. auf der Pixelebene, sind.

There are also approaches to increasing the filling factor in multi-channel imaging systems in the prior art. In principle, a distinction is made between three variants for positioning a field diaphragm structure:

1. 1. In all imaging systems with intermediate image imaging, a real field stop can be introduced into the intermediate image plane, such as in classic light field cameras (cf. Raytrix or the Fraunhofer ultra-flat microscope/Facet Vision).
2. 2. A 3D baffle structure can be introduced between the optics and the sensor, whereby the fill factor is correspondingly limited here, e.g. B. by the cover glass in front of the sensor or the structure size of the baffle array, aspect ratio of web width to opening and thickness (between lenses and cover glass / sensor) can not be chosen arbitrarily large technologically to maintain manufacturability. An application for multispectral elements or a multiaperture camera is shown in [1].
3. 3. Furthermore, a thin baffle grid can be used in the image sensor plane, as is the case, for example, in FIG U.S. 9,202,833 B2 is shown. This is technologically very complex to produce. Furthermore, the absorption does not necessarily have to be guaranteed, since webs are very thin, e.g. B. at the pixel level.

Furthermore, it would also be conceivable for the object field to be delimited, for example by means of adapted lighting (object field smaller than the actual field of view).

the U.S. 5,696,371 A discloses a diffractive/reflective lens array. the DE 10 2009 049 387 A1 describes a device, image processing device and method for optical imaging. In addition, be on the DE 10 2009 047 361 A1 , and the DE 10 2013 209 246 A1 referred.

The object of the present invention is to create a multi-channel imaging system that creates an improved compromise between an increase in fill factor, manufacturability and cost efficiency.

The object is solved by the subject matter of the independent patent claims.

Exemplary embodiments of the present invention create a multi-channel imaging system with an image sensor and at least one first and second channel, each of which has at least one lens or aperture diaphragm layer (generally lens system) and a tandem diaphragm structure. The lens system/aperture diaphragm layer is designed to image light in the direction of incidence from different spatial directions onto the image sensor, with the tandem diaphragm structure being designed to delimit the different spatial directions. For this purpose, it has a first diaphragm, which is located in front of the lens when viewed in the direction of incidence, and a second diaphragm, which is arranged between the lens and the diaphragm sensor.

According to a further exemplary embodiment, the multi-channel imaging system can have a plurality of further channels, each channel having a further lens and a further tandem diaphragm structure.

Exemplary embodiments of the present invention are based on the finding that a significant increase in the fill factor can be achieved by a so-called tandem diaphragm structure in an array arrangement using a tandem diaphragm structure in an array arrangement. The tandem diaphragm structure includes a diaphragm in front of and a diaphragm behind the aperture diaphragm layer for each channel. Assuming that the two or more channels are arranged side by side, the tandem aperture structure of the multiple channels is formed by using an aperture array structure in front and a diaphragm array structure is arranged behind the aperture diaphragm layer, the diaphragm array structure in front of the aperture layer having the first diaphragms and the diaphragm array structure behind the aperture layer having the second diaphragms. By using two apertures per channel, a three-dimensional aperture structure is created for each channel, so that on the one hand good separation from adjacent channels is achieved and on the other hand vignetting effects in the image sections to be detected are minimized. Further advantages are the increase of the non-vignetted field despite dimming. Overall, the design as a 3D panel structure leads to the suppression of scattered light.

According to exemplary embodiments, the two channels or the plurality of channels can be constructed in the same way. This is achieved, for example, in that the first diaphragm array structure used according to the exemplary embodiments (in front of the aperture diaphragm layer) contains the same openings and the second diaphragm array structure (behind the aperture diaphragm layer) contains the same second diaphragm array structures. The aperture diaphragm layers, that is to say the lenses, are also constructed in the same way.

At this point it should be noted that, according to exemplary embodiments, the optical axes of the aperture diaphragm position, the first or second diaphragm and z. B. the first and / or second channel, can be arranged coincidentally. According to further exemplary embodiments, the optical axes in the first diaphragm position, the first diaphragm and the second diaphragm of the first and/or second channel can be arranged offset to one another. This arrangement advantageously makes it possible to shape different spatial directions for different channels.

According to further exemplary embodiments, different channel implementations of the plurality of channels can also be formed, e.g. B. by different shape, size, aspect ratio, orientation and / or relative position to each other. For example, the optical axes of the different channels (eg defined by the first and second apertures) can be aligned at an angle to one another. A parallel alignment would of course also be possible according to other examples.

As already indicated above, several channels are preferably formed. These channels all use a common image sensor and are arrayed along this common image sensor, e.g. B. arranged in an NxM array arrangement. According to exemplary embodiments, it would be conceivable for all first apertures to be formed by a common first aperture array structure and all second apertures to be formed by a common second aperture array structure.

According to exemplary embodiments, the first and/or the second aperture can have a structure that changes in the direction of incidence, e.g. with regard to size and/or shape, e.g. B. have a 3D structure. A preferred exemplary embodiment for this would be a cone for the first and/or second diaphragm in the aperture. According to further exemplary embodiments, it would be conceivable for the first and/or second screen to be formed by a screen structure with a plurality of screen layers. According to exemplary embodiments, these multiple screen layers of the first and/or second screen can be arranged spaced one behind the other and/or coincidentally. According to a further exemplary embodiment, it would also be conceivable for the multiple diaphragm layers to each have different apertures. According to exemplary embodiments, these different apertures could taper, that is to say narrow or widen. A cone of the conical diaphragm arrangement has, for example, a taper extending in the direction of incidence. This is preferred for the first aperture. According to further exemplary embodiments, a cone of the conical diaphragm structure has a widening extending in the direction of incidence. This is preferred for the second aperture. In summary, it should be noted that the cone-shaped widening or narrowing can be formed either by several screen layers or by a 3D screen structure. As a result, for example, the opening angle is cut on both sides, which leads to stronger vignetting of interfering field areas without influencing the image section to be detected. This significantly increases the fill factor. At this point it should be noted that the increase in the fill factor of independent image channels can be achieved on an image sensor/or array.

• 1a eine schematische Darstellung eines Multikanalabbildungssystems mit einem dargestellten Kanal gemäß einem Basisausführungsbeispiel;
• 1b eine schematische Darstellung eines Multikanalabbildungssystems mit einem dargestellten Kanal gemäß erweiterten Ausführungsbeispielen;
• 1c eine schematische Draufsicht auf ein Multikanalabbildungssystem mit vier Kanälen;
• 2 eine schematische Darstellung von unterschiedlichen einzelnen Kanälen in einem Multikanalabbildungssystem gemäß weiteren Ausführungsbeispielen;
• 3 eine schematische Darstellung von zwei unterschiedlich ausgerichteten Kanälen (verschiedene Blickrichtungen) eines Multikanalabbildungssystems gemäß weiteren Ausführungsbeispielen;
• 4 eine schematische Darstellung einer Sensoraufteilung gemäß Ausführungsbeispielen;
• 5a und 5b schematische Darstellungen einer Frontansicht eines Aperturarrays (regulär und irregulär);
• 6 eine schematische Darstellung eines relativen Helligkeitsverlaufs zur Illustration von Ausführungsbeispielen.

Further formations are defined in the dependent claims. Exemplary embodiments of the present invention are explained below with reference to the attached drawings. Show it:

• 1a a schematic representation of a multi-channel imaging system with a channel shown according to a basic embodiment;
• 1b a schematic representation of a multi-channel imaging system with a channel shown according to extended embodiments;
• 1c a schematic plan view of a multi-channel imaging system with four channels;
• 2 a schematic representation of different individual channels in a multi-channel imaging system according to further embodiments;
• 3 a schematic representation of two differently aligned channels (different viewing directions) of a multi-channel imaging system according to further exemplary embodiments;
• 4 a schematic representation of a sensor division according to embodiments;
• 5a and 5b schematic representations of a front view of an aperture array (regular and irregular);
• 6 a schematic representation of a relative brightness profile to illustrate exemplary embodiments.

Before exemplary embodiments of the present invention are explained below with reference to the attached drawings, it is pointed out that elements and structures that remain the same are provided with the same reference symbols, so that the description of them can be applied to one another or are interchangeable.

1a 12 shows a multi-channel imaging system 10 with a detector 12, a lens 14 and a so-called tandem diaphragm structure 16. Alternatively, a lens system or lens system with an aperture diaphragm can be used instead of the lens 14 shown here in simplified form. The lens system or lens system with aperture stop includes, for example, one or more lenses 14. In the section of multi-channel imaging system 16 shown here, only one channel 10_1 is shown, it being assumed that one or more further channels 10_2 can be provided in addition to this channel 10_1. As a rule, several channels share one detector 12.

The tandem diaphragm structure 16 comprises two diaphragm elements 16a and 16b. The stop 16a is positioned in front of the aperture layer/lens 14, while the stop 16b is positioned between the lens 14 and the detector 12. In this exemplary embodiment, it is assumed that the apertures of the diaphragms 16a and 16b are constant when viewed in the direction of incidence 10e and are also aligned coincidentally with respect to the direction of incidence 10e. For example, stop 16a, stop 16b, and lens 14 may be coincidentally aligned on an optical axis. This optical axis can run parallel to the direction of incidence 10e or to the main direction of incidence 10e (cf. collimated bundle of rays 18p). A transverse collimated bundle of rays/transverse beam path (slightly angled) to the direction of incidence 10e is provided with the reference number 18q. The functioning of the multi-channel imaging system 10 is explained below with reference to the channel 10_1.

The multi-channel imaging system 10 is used for the targeted miniaturization of an image to be imaged (cf. incident rays 18p and 18q). In the illustrated schematic side view of the individual channel 10_1, the two collimated bundles of rays 18p and 18q illustrate the incidence on the lens 14 for the different field angles (18p field angle approximately 0°, 18q field angle ≠ 0°). The bundle of rays 18q (field angle ≠ 0 ) is vignetted by the upper-side aperture structure 16a and the image-side aperture structure 16b, so that the bundle of rays 18q is cut symmetrically about the principal ray 18p of the field angle ≠ 0 from above (cf. 16ao) and from below (cf. 16ba). Beam 18q trimmed by two stops 16a and 16b and main beam 18p are focused onto detector 12 using lens 16.

At this point it should be noted that, according to exemplary embodiments, the detector or the detector array for the multiple channels 10_1 and 10_2 can have multiple layers. A cover glass layer 12d and the actual detector array 12a are shown here.

Corresponding to exemplary embodiments, the diaphragms designed here as diaphragms 16a and 16b with constant aperture openings 16aa and 16bo' can also be designed differently. Is in 1b shown.

1b Figure 1 shows the multi-channel imaging system 10', which is essentially the same as the multi-channel imaging system 10, but has different apertures 16a' and 16b'.

The diaphragm 16a' and also the diaphragm 16b' have a 3D structure, which means that the aperture openings 16aa' and 16ba' widen or narrow conically, for example. In this exemplary embodiment, it is assumed that the aperture openings 16aa′ and 16ab′ have a cone shape, although other shapes would of course also be conceivable.

In this exemplary embodiment, the aperture opening 16aa' of the aperture 16a' tapers in the direction of light incidence 10e (ie in the direction from the first aperture 16a' via the lens 14 to the second aperture 16b' and to the detector 12). For example, assuming that the two collimated beams 18p and 18q shown here enclose an angle α, the taper of the opening 16aa' can also enclose an angle β, with β and α being the same or different can be equal. According to the exemplary embodiments, the aperture 16b' can expand conically in the direction 10e, e.g. B. by the angle δ. This angle δ can be equal to or comparable to the angle β.

In other words, it means that the 3D structure of the diaphragm 16a' narrows at the opening 16a'' towards the lens 14, while the diaphragm 16b' with its aperture 16ab' also narrows towards the lens 14 (the means, conversely, to the detector 12 widens). This arrangement results in vignetting of the bundle of rays 18p and 18q on both sides (side of the stop 16a' and side of the stop 16b') for maximum field angles.

In summary, it can be stated that both the miniaturized multi-channel imaging system 10 and the multi-channel imaging system 10' are characterized by a diaphragm array structure 16a or 16a' in front of the aperture diaphragm 14 and by a diaphragm array structure 16b or 16b' behind the aperture diaphragm.

Both in the embodiment 1a as well as in the embodiment 1b it was assumed in each case that only one channel 10_1 is shown. Of course, the miniaturized multi-channel imaging system 10 or 10' can also have multiple channels 10_1 and 10_2, e.g. B. arranged linearly next to each other or two-dimensionally or flatly. A plan view is in 1c shown.

Here the four channels 10_1, 10_2, 10_3 and 10_4 are shown in an NxM matrix with two rows and two columns. In the plan view of the four channels 10_1 to 10_4, the first aperture 16a_1, 16a_2, 16a_3 and 16a_4 is illustrated in each case, with the detector layer 12 being illustrated behind the first aperture. At this point it should be noted that a detector layer 12 is used for the multi-channel imaging system 10 or 10', while each channel 10_1 to 10_4 has its own aperture 16a_1 to 16a_4. Of course, each channel 10_1 to 10_4 also has its own second diaphragm and/or its own lens (not shown).

The screens 16a_1 to 16a_4 could be formed by a screen layer or a common screen layer, ie a screen layer with four aperture openings. This panel layer is provided with the reference number 161 . Of course, a separate screen layer could also be formed for the second screen (not shown).

This therefore means that, according to exemplary embodiments, the diaphragm array structure can be implemented by a linear or two-dimensional diaphragm array, comprising, for example, identical and/or different individual diaphragm structures. In accordance with exemplary embodiments, the apertures 16a_1 to 16a_4 or the respective second apertures can differ between the individual aperture structures, for example in terms of shape, size, aspect ratio, alignment and relative position to one another, as will be explained below. Such a variant is, for example, in 3 shown.

2 shows the design options for the diaphragm structures using three channels 10_1, 10_2 and 10_3 shown side by side, each with three different diaphragm variants (variant A, variant B, variant C). It is assumed that the three channels 10_1, 10_2 and 10_3 shown here all also image the same detector 12 with the two layers 12a and 12b. All channels 10_1, 10_2 and 10_3 and variants A, B and C have in common that they have a lens/lens system 14. The lens 14 is arranged in front of the detector 12, viewed counter to the direction of incidence 10e, with the first aperture 16a or 16a' or 16a" being arranged in front of the lens 14, viewed in the direction of incidence 10e, while the apertures 16b, 16b' or 16b" are arranged between lens 14 and detector plane 12 are arranged. It is assumed that each channel 10_1, 10_2 and 10_3 has a comparable width b10, so that the total width g10 results from the three widths b10. Here the channels 10_1 to 10_3 are arranged directly adjacent to one another, e.g. B. perpendicular to the direction of incidence 10e.

In the case of variant A (cf. channel 10_1), two individual diaphragm layers 16a and 16b are assumed, as in connection with 1a was explained. Variant B (cf. channel 10_2) is based on a 3D aperture structure with conical openings, both on the object side and on the image side, as in connection with 1b was explained. Variant C (see channel 10_1) is a further development of Variant B or a combination of Variant B with Variant A. Three individual screen positions are used here, 16a" or 16b" for each screen. The individual diaphragm layers, here three diaphragm layers, are one behind the other, e.g. B. coincidentally one behind the other, at the respective position of the aperture 16a" or 16b". Furthermore, the diaphragm positions of the diaphragms 16a" and 16b" can be spaced apart from one another. As shown here, the individual diaphragm layers differ in their aperture size. In the case of the diaphragm position 16a", the aperture size of the three diaphragm positions shown is selected, for example, in such a way that the The first diaphragm layer seen in the direction of incidence 10e has a large aperture opening, the aperture opening in the middle is smaller and the aperture opening on the lens 14 is the smallest. In the case of the diaphragm 16b", the diaphragm layer has the smallest dimensions with regard to its aperture opening, which faces the lens 14, while the diaphragm layer has the largest dimensions with regard to its aperture opening, which faces the detector 12. The diaphragm layer in between has a medium-sized Aperture opening. Corresponding to exemplary embodiments, cone-shaped structures are formed by the different diaphragm layers, each diaphragm 16a "or 16b". Both cones are in turn arranged in such a way that the constriction faces the lens 14. In other words, the two diaphragms 16a "and 16b " be described in that they each have at least two diaphragm layers, which differ in terms of their aperture opening or the dimensioning of the aperture opening. According to exemplary embodiments, the diaphragm layer with the smaller aperture opening, per diaphragm 16a" or 16b", faces the lens 14. Correspondingly execution ment examples, this arrangement can be formed either for both screens 16a" or 16b" or also only for one screen 16a" and 16b".

3 shows two channels 10_1 and 10_2 in different variants A and B. Each channel is based on the aperture 16a' or 16b' 2 . In the case of channel 10_1, the optical axes 16ao', 14o' and 16bo' are arranged to be coincident with one another.

In contrast to this, the optical axes 16ao', 14o' and 16bo' are shifted in their position relative to one another. For example, the three optical axes 16ao', 14o' and 16bo' can be shifted obliquely, ie along a line. This enables channel 10_2 to have an inclined channel (cf. 18q from 1a , 1b and 2 ) can be detected.

In connection with 4 a sensor division of an element 10 or 10' will now be explained. 4 shows a top view of a 3x3 sensor array. A total of nine channels 10_1 to 10_9 are shown here, assuming one angular aperture opening for each channel. This therefore means that the sensor field 10 or 10' has individual image channels 10_1 to 10_9 arranged squarely, which image the channels onto the sensor surface (not shown). The sensor area is specified by the sensor height 12h and the sensor width 12b. The image circle 11 of each channel 10_1 to 10_9 is cropped by the aperture structure 16a*, here with a square aperture opening 16ao*, and leads to vignetting of the individual image channel or to spatial delimitation in accordance with the aperture width. This results in so-called dead zones 16ab* (vignetted or unusable area) on the sensor, as shown hatched here. The width of these dead zones are related to the fill factor of the sensor. The wider these dead zones, the lower the fill factor. The aim of this tandem aperture structure is to increase the fill factor (reduce dead zones) and thus make better use of the sensor area.

According to embodiments, different aperture arrays (regular and irregular) can be used. In connection with 5 two different variants A and B are shown. The following discussion focuses on the aperture stop 17a, which has the aperture stops 16a**. This is in each case the first screen, with the second screen of course being able to be constructed analogously. The aperture diaphragm array 17a here has a regular array arrangement with periodically spaced diaphragms 16a**, both in the x and in the y direction. Alternatively, an irregular array arrangement would of course also be conceivable. The distances are illustrated with A16a**, whereby it is assumed here, for example, that both the distances in the x-direction and the distances in the y-direction are the same (optional feature).

In the an irregular array arrangement 19a is shown. This has different apertures 16a**, 16a***, 16a**** and 16a*****. As can be seen, the screen elements 16a** to 16a***** differ in terms of their size, shape (square and rectangular) and the distance from one another.

Referring to 6 the resulting advantage of using two apertures is explained. in the in 6 The diagram shown shows the relative brightness over the normalized field angle, namely for a diaphragm structure on the image side 30b and a tandem diaphragm structure 30t according to exemplary embodiments. This representation illustrates the measured values around the aperture position. The change in the relative brightness of an individual image channel through the combined use of an object-side and image-side diaphragm structure (tandem diaphragm structure) is significantly improved, as the comparison of curves 30b and 30t shows, especially at larger angles (for example from 0.6).

Due to the diaphragm structure on the object and image side (cf. curve 30t), the non-vignetted field increases by a factor of X, with both curves having the same zero crossing at a normalized field angle of 1.

The above embodiments are for classic multi-aperture imaging systems, especially very compact multi-aperture imaging systems such. B. multi-/hyperspectral cameras and polarization cameras, multimodal imaging iA cameras with field of view division (z. B. electronic cluster eye) or multi-channel cameras for super resolution applicable. Further applications are, for example, in optical imaging systems from the UV to LWIR range.

The explanations of the above exemplary embodiments are only illustrative and do not limit the scope of protection. The scope of protection is defined by the subject matter of the claims.

Sources

• [1] M. Hubold, R. Berlich, C. Gassner, R. Brüning, and R. Brunner, "Ultra-compact micro-optical system for multispectral imaging," in MOEMS and Miniaturized Systems XVII, W. Piyawattanametha, Y. -H. Park, H. Zappe, eds. (SPIE, 2018), p. 29. and Hubold, M., Montag, E., Berlich, R., Brunner, R., and Brüning, R., "Multi-aperture system approach for snapshot multispectral imaging applications," Opt. Express 29, 7361-7378 (2021), respectively.

Claims (13)

Multi-channel imaging system (10, 10'), having the following features: an image sensor (12); and at least one first channel (10_1), which has a lens system with an aperture stop (14) and a tandem stop structure (16), and at least one second channel (10_2) with a further lens system with an aperture diaphragm (14) and a further tandem diaphragm structure (16); wherein the lens system (14) is designed to image light in the direction of incidence (10e) from different spatial directions onto the image sensor (12), wherein the tandem diaphragm structure (16) and the further tandem diaphragm structure (16) each have a first diaphragm (16a), which in the direction of incidence (10e) is seen upstream of the aperture stop (14) and has a second stop (16b) in each case, which is arranged between the aperture stop (14) and the image sensor (12); the first (16a) and second aperture (16b) having an aperture structure or 3D aperture structure (16a', 16a", 16b', 16b") that changes in the direction of incidence (10e); or wherein the first (16a) and second aperture (16b) is conical in the direction of incidence (10e). Multi-channel imaging system (10, 10') according to claim 1 , wherein the multi-channel imaging system (10, 10') has a plurality of further channels, each channel having a further aperture diaphragm (14) and a further tandem diaphragm structure (16). Multi-channel imaging system (10, 10') according to claim 1 or 2 , wherein the first (10_1) and second channel (10_2) or the first (10_1) and the plurality of further channels form similar channels or form different channel implementations based on shape, size, aspect ratio, alignment and/or relative position to one another. Multi-channel imaging system (10, 10') according to one of claims 2 or 3 , wherein the plurality of further channels has a common image sensor (12) and wherein the plurality of further channels are arranged along the common image sensor (12) in a linear array arrangement or NxM array arrangement. Multi-channel imaging system (10, 10') according to one of the preceding claims, wherein the first (16a) and/or second aperture (16b) is/are formed by an aperture structure with a plurality of aperture layers. Multi-channel imaging system (10, 10') according to claim 5 , wherein the plurality of screen layers for each first (16a) and/or for each second screen (16b) are spaced one behind the other and/or are arranged coincidentally. Multi-channel imaging system (10, 10') according to claim 5 or 6 , wherein the multiple diaphragm layers each have a different aperture. Multi-channel imaging system (10, 10') according to claim 7 , whereby the different apertures of the diaphragm layers taper conically. Multi-channel imaging system (10, 10') according to one of Claims 1 until 8th , wherein a cone of the conical diaphragm arrangement of the first diaphragm (16a) has a taper in the direction of incidence (10e). Multi-channel imaging system (10, 10') according to one of Claims 1 until 9 , wherein a cone of the conical diaphragm structure of the second diaphragm (16b) has a widening in the direction of incidence (10e). Multi-channel imaging system (10, 10') according to one of Claims 1 until 10 , wherein the optical axes of the different channels are oriented parallel or oriented at an angle to each other. Multi-channel imaging system (10, 10') according to any one of the preceding claims, wherein the opti cal axes of the aperture stop (14), the first stop (16a) and the second stop (16b) of the first (10_1) and/or second channel (10_2) are arranged coincidentally. Multi-channel imaging system (10, 10') according to one of Claims 1 until 11 , wherein the optical axes of the first aperture stop (14), the first stop (16a) and the second stop (16b) of the first (10_1) and/or second channel (10_2) are offset, laterally offset or angled relative to one another.

Images