EP4305447A1

EP4305447A1 - Optical system for obtaining 3d spatial information

Info

Publication number: EP4305447A1
Application number: EP22709973.6A
Authority: EP
Inventors: Julian Berlow
Original assignee: Scoobe3d GmbH
Current assignee: Scoobe3d GmbH
Priority date: 2021-03-11
Filing date: 2022-02-14
Publication date: 2024-01-17
Also published as: CN117178195A; DE102021105888A1; WO2022189094A1; US20240125938A1

Abstract

The invention relates to an optical system for obtaining 3D spatial information within a spatial region, in particular for detecting 3D information regarding an object, comprising: - a light receiving device (110) comprising at least one light detector which can be or is oriented towards the spatial region; - an optical modulator unit (106) for rotating a polarisation of light passing through the modulator unit (106); and - at least one polarisation filter (111) which is situated optically downstream of the modulator unit; wherein at least one bandpass filter is provided which is situated optically downstream of the polarisation filter and/or wherein the modulator unit comprises at least two optical modulators.

Description

Optical system for obtaining 3D spatial information

description

The invention relates to an optical system for acquiring 3D spatial information within a spatial region, in particular for acquiring 3D information about an object, a corresponding image processing system and a corresponding optical method.

WO 2018/033446 A1 describes an optical device, preferably based on the time-of-flight principle, for obtaining 3D spatial information. Light is influenced (or rotated) with regard to its polarization by means of an optical modulator, with the optical modulator being followed by a polarization filter which only allows the light influenced (rotated) by the modulator in certain cases. As a result, it is fundamentally possible to obtain 3D spatial information quickly and precisely.

Proceeding from this state of the art, it is the object of the invention to propose an optical system for acquiring 3D spatial information within a spatial region, in particular for acquiring 3D information of an object, which in a comparatively simple manner enables precise acquisition of the 3D spatial information enabled. Furthermore, it is the object of the invention to propose a corresponding image processing system and a corresponding optical method. In particular, one should Inexpensive 3D imaging with a comparatively high level of accuracy (in particular in the millimeter or micrometer range) can be made possible.

This object is achieved in particular by the features of claim 1.

In particular, the object is achieved by an optical system for obtaining 3D spatial information within a spatial area, in particular for acquiring 3D information of an object (in particular from its outer surface), comprising: a light receiving device with at least one light detector which is directed to the spatial area ( or the object) can be aligned or aligned, at least one optical modulator unit for (variably) rotating a polarization of a light passing through the modulator unit, and at least one polarization filter which is optically connected before or (preferably) after the modulator unit.

According to a first particularly preferred aspect of the invention, at least one color filter, in particular a bandpass filter, is provided, which is optically connected before or (preferably) after the polarization filter. It has been shown that by using such a color filter, in particular a bandpass filter, the precision in obtaining the 3D information can be improved in a comparatively simple manner. In particular, such a color filter, in particular a bandpass filter, can reduce noise and thus increase accuracy by a comparatively significant amount.

According to a second particularly preferred aspect of the invention, the modulator unit comprises at least two (optically cascaded) optical modulators (each individually configured to rotate a polarization of a light passing through). In this context, comparatively inexpensive modulators (e.g. liquid crystal cells, in particular TN cells) can be used, with a comparatively high Number of possible angles of rotation for the rotation of the light beam can be realized. For example, with four modulators (liquid crystal cells), each of which can be switched on and off individually, 2 ⁴ =16 different (polarization) angles of rotation can be realized. This multiplicity of modulators in combination is particularly preferred used with the color, especially bandpass filter. Such a combination can easily reduce a possible unsharpness resulting from the plurality of modulators or a corresponding noise (of the specific modulator unit).

According to a third particularly preferred aspect of the invention, the system has at least one 3D information acquisition unit, in particular at least one RGB camera. With such an (additional) 3D information acquisition unit, in particular in the form of an RGB camera, precise acquisition of 3D information under different conditions (or properties of objects to be acquired) can be achieved in a particularly simple manner. In this respect, the advantages of the 3D information acquisition unit (RGB camera) complement each other synergistically with the advantages resulting from the arrangement of the optical modulator unit and polarization filter. Alternatively or additionally, the system or the 3D information acquisition unit can have a fringe projection device and/or a laser scanning device and/or a laser triangulation device and/or a ToF (time of flight) camera for acquiring 3D information exhibit.

According to a fourth preferred aspect of the invention, at least one position detection unit (for detecting a position or orientation of the light receiving device, for example an RGB camera in relation to the spatial area to be detected or the object to be detected), in particular at least one gyroscope and/or accelerometer, intended. Such a measure makes it possible for the light detection unit to be or can be guided (e.g. automatically and/or by appropriate action by the operator of the system) at such an angle (e.g. around the object) that a comparatively good (in particular optimized) recording of the 3D information is made possible. A control unit is particularly preferably provided which is configured to determine and/or to output when a position (of the light detection unit) that is advantageous for measuring the spatial area is present relative to the spatial area to be measured, and/or a display is provided which shows the operator if there is a position (of the light detection unit) that is advantageous for measuring the spatial area in relation to the spatial area to be measured. The respective modulator unit comprises at least one modulator, preferably multiple modulators.

The (respective) modulator can preferably assume at least or exactly two states, preferably an inactive state in which the modulator does not (at least not significantly) rotate passing light and an active state in which the modulator can rotate the passing light by a certain angle (Possibly depending on the direction of polarization of the incident light).

The (respective) modulator (in particular liquid crystal device) can be anti-reflection coated.

The (respective) modulator (in particular liquid crystal device) can be arranged inside an objective.

The (respective) modulator unit can have a large number of modulators for pixel-by-pixel modulation of the polarization, e.g. B. a microsystem comprising a liquid crystal micro-array.

Preferably, at least one light generating device is provided for sending light into the spatial area. The light generating device can have at least one light emitter (eg an LED or several LEDs).

In embodiments, the light generating device comprises at least one LED, for example a white light LED. Alternatively or additionally, the light generating device can comprise at least or precisely one IR light transmission device (in particular NIR light transmission device).

Alternatively or additionally, the light-generating device can have at least one light-transmitting device (in particular an RGB light-transmitting device, e.g. in the form of at least three LEDs in the colors R, G and B), which is used to emit at least two, preferably at least or exactly three ( or at least or exactly four) different colors is configured.

The light generating device preferably comprises at least one diffuser. In particular, a combination of at least one LED and at least one diffuser ensures and/or the "unpolarized world assumption" that is advantageous for processing the acquired data can ensure sufficient brightness in a corresponding wave range, in particular to enable a comparatively short exposure time of a camera(s). In particular, this means that the system can also be used in a mobile (hand-held) manner.

In specific embodiments, the system can have a display, for example for displaying an app, which can be stored (stored) within the system, for example. The display can be designed as a touch screen.

According to the embodiment, the modulator unit can comprise one or more, in particular at least or exactly three or at least or exactly four, preferably optically connected in series, liquid crystal device(s), preferably as TN effect-based device(s), as modulator(s). A TN effect-based device is to be understood in particular as a device which is based on the twisted nematic effect (TN effect) (such as in particular a TN cell or Schadt-Halfrich cell). Such devices based on the TN effect (liquid crystals) are comparatively inexpensive. A large number of polarization angles or directions of the light can be achieved in particular with a large number of such devices based on the TN effect (by utilizing the respective change or rotation of the polarization of the light passing through).

The modulator unit preferably has at least or exactly two or at least or exactly three or at least or exactly four modulators optically connected in series, in particular liquid crystal devices (TN cells). These are preferably configured and arranged in relation to one another such that the respective optically downstream modulator (in particular with regard to its transmission behavior and/or a transmitted intensity) is matched, in particular optimized, to at least one polarization direction emerging from the upstream modulator. An input of the downstream modulator is particularly preferably optimized for the polarization directions (usually) emerging from the upstream modulator (in particular with regard to manufacture or configuration and positioning/orientation). The system preferably comprises an evaluation unit, in particular comprising a (micro)processor and/or (micro)controller, for evaluating data recorded by the light detection unit. The evaluation unit is configured in particular to determine (in particular to calculate) 3D spatial information about the 3D structure of the spatial region from the recorded data, in particular to determine (in particular to calculate) 3D information about an object (in particular on the surface of the same) and, if necessary, .

In principle, the system (in particular the evaluation unit and/or the control unit explained below) can comprise at least one processor (CPU) and/or at least one (micro)controller and/or at least one (electronic) memory.

In embodiments, the color, in particular bandpass filter can be a single color, in particular bandpass filter and/or a multiple, preferably triple color, in particular bandpass filter, in particular for at least two colors (channels, preferably the colors (channels) red, green and blue) comprise/comprise or be formed from.

A single color filter, in particular a bandpass filter, can be combined in particular with at least one IR illumination (illuminating unit), particularly preferably NIR illumination (ie illumination with light in the near infrared range). Alternatively or additionally, a triple color filter, in particular a bandpass filter, can be combined with multicolored lighting, in particular RGB lighting. With such solutions, scattered light (particularly from deeper areas of the material) can also be recorded particularly effectively and evaluated accordingly. As a result, the accuracy in determining the 3D structures can be improved.

The (optional) light generating device preferably emits polarized light or light with a preferred polarization direction. Alternatively or additionally, the light generating device can also be configured to emit unpolarized light or light without a preferred direction of polarization. In addition or as an alternative to light from a light generating device, other light (eg sunlight and/or room lighting) can also be used. An (electronic) control device/control unit is preferably provided for controlling the optical modulator unit.

The system can be partially or fully implemented by a mobile terminal.

The system is preferably housed in a common assembly, for example defined by a housing. The above evaluation unit can also be accommodated (partially or completely) in this assembly group. Alternatively or additionally, the evaluation unit can be provided externally to the assembly and/or at least the light detection unit (for example by a server or other, in particular electronic, computing unit) that communicates with the other components of the system. This communication does not (but can) take place immediately. It would also be conceivable for corresponding data to be initially recorded by the system, then stored in a memory (in particular in the system) and evaluated by the evaluation unit at a later point in time. The assembly and/or the housing can have a (maximum) diameter (defined in particular as the distance between two points of the pair of points that are the greatest distance from one another) of no more than 50 cm or no more than 30 cm or no more than 14 cm and/or at least 5 cm . The assembly may weigh no more than 4.0 kg, or no more than 1.0 kg, or no more than 500 g, and/or at least 40 g.

The system can have several polarization filters (possibly as a polarization filter unit and/or assembly). If this is the case, they may have a different orientation.

The (respective) color filter, in particular the bandpass filter, can be provided within a camera module.

The system can be expandable with external optics (e.g. a lens). The system can have at least one additional device, in particular at least one plug-in module, such as at least one camera, at least one remote release and/or at least one power bank.

The system (the unit) can be used to communicate with at least one other system and/or a (other) external device, in particular wirelessly, preferably via WLAN and/or Bluetooth, and/or wired, e.g. g. via USB/USB-C.

Several (intercommunicating systems/units) can be deployed simultaneously, for example at different angles and/or distances to the structure to be measured. This means that faster and/or larger 3D scans can be carried out if necessary. The above-mentioned object is also achieved in particular by an image processing system for obtaining 3D spatial information, which comprises an optical system of the above type.

The above object is also achieved by an optical method for obtaining 3D spatial information using an optical system as described above and/or below. Further optional method steps result from the description above and below, in particular from the functional features described, which can be implemented in terms of method by corresponding method steps.

The above-mentioned object is also achieved in particular by using an optical system of the type described above and/or below for obtaining 3D spatial information.

In embodiments, the system can preferably work according to the time-of-flight principle and/or have at least one TOF camera (possibly in addition to at least one RGB camera).

In principle, it is assumed that the polarization properties of the light reflected from a surface and/or scattered in layers close to the surface allow conclusions to be drawn about the nature of the reflecting surface. It is important that the nature of light to form a transverse wave must be fulfilled. The invention is based on the evaluation of polarization information of the light reflected (or backscattered) from the surface of an object. In particular, a number of (3D) images can be recorded using the optical device, with a different polarization state being able to be emphasized in each case. This filtering of the polarization component can be adjusted quickly (in the range of microseconds, ie in particular 1 to 1000 microseconds or even nanoseconds, in particular 1 to 1000 ns), precisely, reliably and with little maintenance. A central component can be seen in the optical modulator unit, which can enable this rapid adjustment. Theoretically, a similar effect could also be achieved with the mechanical movement (rotation) of a (commercially available) polarization filter. However, such a mechanical movement (rotation) is not comparable or insufficient in terms of speed, precision and reliability.

In particular, one idea is that light impinging on a filter is (before) rotated in its polarization with an optical modulator unit (instead of rotating a polarization filter). After the polarization has been filtered, such a rotation can optionally be rotated back again by a further optical modulator unit (comprising one or more modulator(s)).

Overall, an optical device can be provided that allows an increase in accuracy through fast, precise, reliable and low-maintenance filtering of the corresponding polarization component. The filtering is achieved in particular by a combination of an optical modulator (or several optical modulators) and a polarization filter (or several polarization filters). Furthermore, the device according to the invention creates a possibility of effectively influencing the contrast in a camera image during an image recording or between image recordings. This is particularly advantageous precisely in image processing, since the contrast can be optically adjusted in the event of a change in the corresponding examination object (eg by software command by a computing unit). This enables a comparatively high degree of flexibility and a comparatively stable application. In summary, polarization information (eg gray value images) is obtained in an advantageous manner as a function of the filtered polarization state. In this way, rapid switching between the polarization states (angles of rotation) to be filtered is achieved. This in turn enables the polarization information to be used effectively in the (industrial) application.

Further preferred embodiments are the subject matter of the dependent claims and/or the following parts of the description.

Optionally, the polarization manipulator (between the polarization filter and the light receiving device) comprises at least one (additional/second) optical modulator unit. This allows the polarization to be rotated back if necessary (at least partially, at any angle) after rotation and filtering, so that the effect of rotating a standard polarizing filter by 90 degrees can be approximated or (identically) simulated if necessary. As a result, the overall influence of the optical modulation units may be limited to the fact that filtering is carried out according to the polarization and no (actually unnecessary and/or possibly even undesirable) permanent rotation of the polarization is brought about. This may be advantageous if the light detector has polarization-dependent sensitivity.

In alternative embodiments, at least one (additional) camera, preferably at least one time-of-flight camera (in particular a PMD camera, preferably comprising a PMD sensor, in particular PMD chip, where PMD stands for Photonic Mixing Device), can be provided, which may

Can be part of the light detection unit. Images delivered by a time of flight already contain distance information, which is why one can also speak of 3D images. The use of a time-of-flight camera in the device according to the invention is particularly advantageous because in this way 3D images can be produced with an accuracy in the micrometer range (1 micrometer to 1000 micrometers) or even in the nanometer range (1 nanometer to 1000 nanometers) (e.g. 1 nanometer - 1,000 micrometers, preferably 1 nanometer - 500 micrometers, more preferably 1 nanometer - 200 micrometers, even more preferably 1 nanometer - 1000 nanometers). In one embodiment, a further polarization and filter unit (comprising at least one modulator unit and at least one polarization filter) (directly and/or at a small distance) is constructed in the reverse order, in particular with regard to the order of the components (i.e. in particular with regard to the order of the optical modulator and polarization filter). of, for example, less than 10 mm) arranged in front of the light generating device. Such a further (second) polarization and filter unit can be arranged and configured such that the light first passes through the polarization filter and then through the optical modulator unit. In particular when optically active materials are illuminated and examined, the incident polarization is changed by the optically active material.

In this case, this means that when (unpolarized) light is radiated in, the evaluation device may not be able to obtain reliable analyzes from the polarization-dependent images of the light receiving unit, since the change in polarization is caused both by the geometric shape of the reflecting object and by the optically active material (and therefore may not be clearly assigned). In this case, the use of the (additional) polarization and filter unit in front of the light generation unit is particularly advantageous since the entire polarization information can continue to be separated and processed here.

In an alternative embodiment, the light-generating device emits polarized light (or light with an, in particular clear, preferred direction of polarization). In a further preferred embodiment, the light-generating device emits unpolarized light (or light without a, in particular clear, preferred direction in the polarization). Especially when using unpolarized light, the desired information can be determined quickly and precisely.

In one embodiment, the light generating unit comprises (at least one) laser. This is particularly advantageous in the case of larger distances, since lasers produce a strong light that can be easily collimated. According to an alternative embodiment, the light generating unit comprises at least one LED, possibly at least 10 LEDs, optionally at least 100 LEDs. Preferably, the light generating device (in particular the LEDs are) operated in a pulsed and/or modulated manner (particularly preferably according to the PWM principle) (with a corresponding pulse generation and/or modulation device being provided can be). Pulsed operation of the LEDs allows them to (briefly) absorb a higher current, which means that greater light intensities are possible.

A comparatively large number of LEDs enables homogeneous illumination of the reflecting object, which means that larger objects can also be detected in their geometric shape. Furthermore, it is advantageous that pulsed operation of the LED lighting or the flashing of the LEDs reduces the influence of extraneous light that does not originate from the light generating device, and the quality of the image information is thus increased.

The respective optical modulator preferably comprises, in particular an electro-optically controlled, liquid crystal arrangement or consists of such. This has the advantage that the polarization can be rotated very quickly and reliably. Alternatively or additionally, the respective optical modulator can comprise at least (or precisely) one electro-optical and/or at least (or precisely) one magneto-optical and/or at least (or precisely) one acousto-optical device.

Optionally, the polarization manipulator (before the light enters) includes a quarter-wave plate. This allows circularly polarized light to be used (instead of linearly polarized light). As an alternative or in addition, parallelization optics for parallelizing incoming light beams can be arranged in front of the polarization manipulator.

The respective optical modulator may (in an active state) have a slow axis which is preferably designed to be oriented or orientable perpendicular to the direction of light propagation and/or at a 45 degree angle to the transmission direction of the polarization filter. The optical modulator (in the active state) can act like a half-wave plate. Furthermore, the at least one optical modulator (in an active state) can have a slow axis, which is preferably designed in such a way that it is aligned or can be aligned in the longitudinal direction (i.e. in particular in the direction of propagation of the light passing through it), the optical Modulator possibly a (continuous) phase shift (and thus polarization rotation) allows. The optical device can have a control device for (time-dependent) control of the respective modulator unit or the respective optical modulator.

Overall, the image recording can be made possible for a number of different polarization states (or polarization angles), with one image being able to be recorded for each polarization state. This is advantageous in that (possibly one after the other) all the polarization information contained in the light can be recorded and, if necessary, individual images can be processed (separately from one another), so that the information can be used effectively. Furthermore, if necessary, redundancies can be generated in this way, which make it possible to obtain more precise and more reliable information from an algorithm that processes the images.

Further embodiments emerge from the dependent claims.

The invention is described below using exemplary embodiments which are explained in more detail using the figures. Here show:

Fig. 1 an optical system according to the invention in a schematic

Opinion; and

Fig. 2 shows a detail of the system according to the invention in a schematic

Opinion.

In the following description, the same reference numerals are used for the same parts and parts with the same effect.

1 shows an embodiment of the optical system 9 according to the invention. This includes an RGB camera 10 (RGB camera module) and a polarization and filter unit 11. The system 9 is configured to determine 3D information regarding an object 12 to be measured. In this case, the object 12 is illuminated by sunlight 13 (a light-generating device would also be conceivable for reference number 13, in particular as a component of the system). The polarization and filter unit 11 is shown in greater detail in FIG. Accordingly, the polarization and filter unit 11 comprises a plurality of modulators 14 (in this case four, which is optional, however) (which can in particular be in the form of liquid crystals), a polarization filter 15 and a color filter, in particular a bandpass filter 16.

It should be noted that polarized light basically contains 3D spatial information (cf. also WO 2018/033446 A1).

The system 9 can also have a gyroscope 18 and, as a light generation unit 19, specifically an LED light with a diffuser (not shown in the figures).

The mode of operation of the invention is explained below (in part with reference to the concrete exemplary embodiment according to FIGS. 1 and 2).

Accordingly, the object 12 can be irradiated with (at least essentially) unpolarized light from the light source (for example LED with diffuser). Basically, the integrated LED-based light source and/or an external light source (e.g. sun, room lighting and/or the like) can be used.

The light is now (in interaction with the object 12) partially polarized by reflection and/or scattering. When considering the light beams running from the object 12 to the light detection unit (specifically RGB camera), the strength (or extent) of the polarization depends on the angle of the beams to the scattering or reflecting surface. Specifically, it is assumed here that not only reflection but also scattering polarizes light beams. Polarization is generally present with scattering and/or diffuse reflection.

A first modulator 14 (far right in FIG. 2) can (if it is in an optically active state or is switched accordingly) rotate the polarization of all individual photons by a specific angle. When this modulator 14 is inactive, the polarization is not (or at least not substantially) changed. An input of a second modulator 14 (half right in FIG. 2) can preferably be adapted, in particular optimized, to the polarization directions which usually emerge from the modulator 14 on the far right. The second modulator (half right in FIG. 14) can also rotate the polarization if it is switched optically active. Again, no (or no significant) rotation occurs when the second modulator is not switched optically active.

A third (half-blink in FIG. 2) and fourth (far left in FIG. 2) modulators are preferably configured and constructed analogously to the first and second modulators, respectively.

With the configuration shown in FIG. 2, a total of ⁴ (ie 16) different states for the polarization (or angle of rotation for the same) can be realized by switching the individual modulators 24 on and off. 3D spatial information can then be obtained from this (as shown in greater detail in WO 2018/033446 A1).

The polarization filter 15 can now let through photons of a (specific) polarization direction. Overall, the polarization and filter unit 11 according to FIGS. 1 and 2 can supply data of a quality comparable to that of a rotatable polarization filter. In contrast to such a rotatable polarization filter, however, the present solution is comparatively inexpensive, requires little maintenance and has a comparatively high level of repeatability.

Since a distance (or an extent) of the rotation of the polarization in the respective modulator 14 can fundamentally be wavelength-dependent, the polarization directions (states) can possibly be determined somewhat less precisely (or noise can be comparatively high). By using the color filter, in particular bandpass filter 16, noise can be suppressed by reducing a wavelength range that is passed through, and thus accuracy can be increased (the use of a triple color filter, in particular bandpass filter for the colors or Red, green and blue channels are used). After passing through (if not filtered out) the polarization and filter unit 11, the photons hit the RGB camera 10 and can optionally be converted into an image there (or in an optionally external evaluation unit). Spatial information can be extracted with comparatively high accuracy from (successive) intensity comparisons.

Basically, a combination of LED and diffuser (as a light generating unit) ensures a simple and effective "unpolarized world assumption" (unpolarized world assumption) and can ensure a comparatively high brightness in a corresponding wavelength range, in particular to ensure a short exposure time of the camera 10 In this way, in particular, the system 9 can also be used in a mobile (hand-held) manner.

For example, the system can be designed as a mobile terminal, in particular comprising a processor, an electronic memory and a display. A weight of the system can be less than 1 kg, possibly less than 500 g.

As already explained above, polarization can also occur with diffuse radiation and contain spatial information (even if the literature often only speaks of polarization through reflection). The use of polarization by scattering has not been described in the present context.

Instead of using a complex modulator (liquid crystal), a combination of several (simple) liquid crystal cells is particularly preferred and particularly economical.

The color filter, in particular the bandpass filter, preferably reduces noise and can increase the accuracy, for example, by at least a factor of 2 or even at least a factor of 3. The color, in particular bandpass, filter preferably has a transmission width of at most 200 nm, more preferably at most 120 nm, even more preferably at most 80 nm, even more preferably at most 60 nm, even more preferably at most 40 nm and/or at least 1 nm or at least 10 nm. Since scattering can occur in a comparatively deep area of material (compared to reflection), a respective color of the object to be measured (or a color of the same) can have a relevant effect on the measurement. For this reason in particular, a system with a single color, in particular bandpass filter and NIR lighting and/or a triple color, in particular bandpass filter and RGB lighting is particularly preferred.

At this point it should be pointed out that all the parts described above, viewed individually and in any combination, in particular the details shown in the drawings, are claimed to be essential to the invention.

Modifications of this are familiar to those skilled in the art.

Reference sign

9 systems

10 RGB camera

11 polarization and filter unit

12 object

13 sunlight

14 modulator

15 polarizing filters

16 color, especially bandpass filter

18 gyroscope

19 light generating unit

Claims

Expectations

1. Optical system (9) for obtaining 3D spatial information within a spatial area, in particular for detecting 3D information of an object (12), comprising:

- A light receiving device, comprising at least one light detector, which can be aligned or is aligned with the spatial area;

- at least one optical modulator unit for rotating a polarization of a light passing through the modulator unit; and

- At least one polarization filter (15) which is optically connected downstream of the modulator unit; wherein at least one color filter, in particular bandpass filter (16), is provided, which is optically connected upstream or downstream of the polarization filter (15), and/or wherein the modulator unit comprises at least two optical modulators.

2. Optical system, in particular according to claim 1, for obtaining 3D spatial information within a spatial region, in particular for detecting 3D information of an object (12), comprising:

- A light receiving device, comprising at least one light detector, which can be aligned or is aligned with the spatial area; - an optical modulator unit for rotating a polarization of a light passing through the modulator unit; and

- At least one polarization filter (15) which is optically connected downstream of the modulator unit; at least one 3D information acquisition and/or position acquisition unit, in particular at least one RGB camera and/or at least one gyroscope, being provided.

3. System (9) according to claim 1 or 2, dad u rch geken nzeich net that a light generating device having at least one light transmitter for sending light into the spatial area is provided, wherein the light generating device preferably: at least one LED, z . B. white light LED, and/or at least one diffuser and/or at least or precisely one IR light emitting device and/or at least one light emitting device, in particular RGB light emitting device, for emitting at least two, preferably at least or precisely three different colors.

4. System (9) according to one of the preceding claims, dad u rch geken nzeich net that a display is provided.

5. System (9) according to one of the preceding claims, characterized in that the modulator unit has one or more, in particular at least or exactly three or at least or exactly four, preferably optically connected in series, liquid crystal device(s), preferably as a TN - Effect-based device(s) included as modulator(s).

6. System (9) according to any one of the preceding claims, dad u rch g eken nzeich net that the modulator unit at least or exactly two or at least or exactly three or at least or exactly four optically cascaded modulators, in particular Liquid crystal devices, which are preferably configured and arranged in relation to one another in such a way that the respective optically downstream modulator (14) is matched, in particular optimized, to at least one polarization direction emerging from the upstream modulator (14).

7. System (9) according to one of the preceding claims, dad u rch geken nzeich net that an evaluation unit, in particular comprising a processor, is provided for evaluating data recorded by the light detection unit.

8. System (9) according to one of the preceding claims, dad u rch geken nzeich net that the color filter, in particular bandpass filter, a single color filter, in particular single bandpass filter (16), and / or a multiple Color filters, in particular multiple, preferably triple color filters, in particular triple bandpass filters, in particular for at least two colors, preferably the colors red, green and blue, comprise/comprise or are formed from them.

9. System (9) according to one of the preceding claims, d a d u rc h g e ke n n ze i c h net that the light generating device emits polarized light or light with a preferred direction of polarization, or that the light generating device emits unpolarized light or light without a preferred direction of polarization emits.

10. System (9) according to one of the preceding claims, d a d u rc h g e ke n n ze i c h n et that a control device for controlling the optical modulator unit is provided.

11. System (9) according to one of the preceding claims, dadu rc hge kenn ze net that the system, with or without an evaluation unit, is housed in a common assembly, preferably defined by a housing.

12. Image processing system for obtaining 3D spatial information, comprising an optical system (9) according to any one of the preceding claims.

13. Optical method for obtaining 3D spatial information using an optical system according to any one of the preceding claims.

14. Use of an optical system according to any one of the preceding claims for obtaining 3D spatial information.