Transmitting unit for a lidar sensor, lidar sensor and method for emitting primary light into a field of view

Abstract

A transmitting unit for emitting primary light into a field of view of a lidar sensor, a lidar sensor and a method for emitting primary light, the transmitting unit having at least one emitter unit configured to emit primary light in the form of an illumination pattern, the illumination pattern having at least a first and a second extension dimension oriented orthogonal to each other, the first being larger or smaller than the second extension dimension, the emitted illumination pattern being oriented along an orientation vector parallel to the first extension dimension; and the transmitting unit having at least one first turning mirror configured to turn the primary light onto a movable mirror and at least one movable mirror configured to scan the primary light in the field of view along a first direction and along a second direction oriented perpendicular to the first direction; the first turning mirror being arranged in the primary light beam path, the primary light emitted by the emitter unit being incident at a first angle of incidence of less than ±12°, preferably less than ±9°, particularly preferably less than ±7°, with respect to a surface normal of the first turning mirror.

Description

Technical Field

[0001] The present invention relates to a transmitting unit for a lidar sensor, a lidar sensor, and a method for transmitting primary light into a field of view by means of a lidar sensor. Background Technology

[0002] DE102017123878A1 discloses a transmitting device, which preferably comprises at least two laser diodes and a scanning mirror deflectable about its center point, the scanning mirror being arranged within a housing having a transparent covering element. The covering element is formed at least in the coupled output region by a segment of a single-centered hemispherical shell having a center point of curvature and in the coupled input region by an optical block, the single-centered hemispherical shell covering the scanning mirror and arranged such that the center point of curvature coincides with the center point of the scanning mirror. The optical block has a toroidal entry surface, at least one toroidal exit surface, and at least one first mirror disposed therebetween, the first mirror being used for steering and pre-collimating the laser beam. Summary of the Invention

[0003] This invention relates to a transmitting unit for a lidar sensor, the transmitting unit being used to emit primary light into the field of view of the lidar sensor. The transmitting unit has at least one transmitter unit configured to emit primary light in the form of an illumination pattern, wherein the illumination pattern has at least first and second extension scales orthogonally oriented to each other, wherein the first extension scale is greater than or less than the second extension scale, and wherein the emitted illumination pattern is oriented along an orientation vector parallel to the first extension scale. The transmitting unit also has at least one first steering mirror and at least one movable mirror. The first steering mirror is configured to direct the primary light onto the movable mirror. The movable mirror is configured to scan the primary light in the field of view along a first direction and along a second direction oriented perpendicular to the first direction. The first steering mirror is arranged in the beam path of the primary light such that the primary light emitted by the transmitter unit is incident at a first incident angle of less than ±12°, preferably less than ±9°, and particularly preferably less than ±7° relative to the surface normal of the first steering mirror.

[0004] The first angle of incidence relative to the surface normal of the first steering mirror should be understood here in particular as a vertical angle of incidence. The primary light can simultaneously enter the steering mirror at a second angle of incidence relative to the surface normal of the first mirror. The second angle of incidence should be understood here in particular as a horizontal angle of incidence. The second angle of incidence can, for example, reach ±20°.

[0005] The first direction is preferably oriented perpendicular to the orientation vector of the illumination pattern. The second direction is preferably oriented parallel to the orientation vector of the illumination pattern. The orientation vector of the illumination pattern is preferably perpendicular to the first direction and parallel to the second direction.

[0006] The transmitter unit can have at least one laser. The at least one laser can be configured as a DFB laser (Distributed Feedback), a DBR laser (Distributed Bragg Reflector), an edge or surface emitter, or a solid-state laser. The laser of the transmitter unit can be configured to be temperature stable. The transmitter unit can have a single laser with high divergence along a first direction. The transmitter unit can have a single laser with high divergence along a second direction. The transmitter unit can have multiple lasers configured to generate an illumination pattern. For this purpose, the multiple lasers can be arranged, for example, in columns or rows. The transmitting unit can have additional optical elements, such as optical lenses, mirrors, beam splitters, etc. The illumination pattern can also be constructed using such optical elements. In the optical path of the transmitting unit, shortly after leaving the lidar sensor (immediately or within a few centimeters), the illumination pattern can generate a field of view with increasingly uniform and continuous illumination at the distance to the lidar sensor. The transmitter unit is particularly configured to emit primary light in a pulsed manner. The transmitter unit is particularly configured to emit an illumination pattern in a pulsed manner. The illumination pattern is particularly configured as lines, rectangles, or patterns, such as a checkerboard pattern.

[0007] The first steering mirror is specifically constructed to be immovable. The first steering mirror can also be called a folding mirror. As an alternative to the first steering mirror, the transmitting unit can also have other first steering elements. Such first steering elements can be, for example, prisms or diffractive optical elements with steering functions. The movable mirror can be moved by means of an electric, electromagnetic, and / or piezoelectric drive unit. The movable mirror can be constructed as a micromechanical mirror. The movable mirror can have dimensions ranging from several to multiple 100 μm. The movable mirror can have dimensions in the millimeter range. By moving the movable mirror along its two axes, the field of view of the lidar sensor can be scanned.

[0008] The primary beam is arranged vertically in the field of view along a first direction of its scanning primary beam. It is also arranged horizontally in the field of view along a second direction of its scanning primary beam. Alternatively, it may be arranged horizontally in the first direction and vertically in the second direction in the field of view.

[0009] The advantage of this invention is that the structural size of the transmitting unit can be kept small by means of the first steering mirror. Correspondingly, the structural size of the lidar sensor can also be kept small by means of the first steering mirror. Since the primary light emitted by the transmitter unit is incident at an angle of less than ±12° relative to the surface normal of the first steering mirror, the orientation vector can be rotated by an angle close to 0° or close to 90° due to reflection on the first steering mirror. Other angular rotations, especially those significantly different from 0° or 90°, can be avoided. Thus, the orientation vector of the illumination pattern can be oriented perpendicular to the first direction and parallel to the second direction when leaving the lidar sensor. The orientation vector of the illumination pattern can be oriented almost perpendicular to the first direction and almost parallel to the second direction when leaving the lidar sensor. Twisting of the orientation vector can be avoided. Especially in the case of a large field of view, this can lead to a more uniform scanning of the field of view. Specifically, areas of the lidar sensor's field of view that are far from the lidar sensor (e.g., at a distance of 100m) can be scanned uniformly. This allows for virtually seamless illumination during field-of-view scanning, avoiding unlit areas within the field of view. Consequently, the risk of failing to detect small objects within the field of view is significantly reduced.

[0010] In an advantageous configuration of the invention, the movable mirror is arranged in the beam path of the primary light such that the primary light, deflected by the first deflecting mirror, enters at a first angle of incidence less than ±12° relative to the surface normal of the movable mirror. This first angle of incidence relative to the surface normal of the movable mirror is here understood in particular as a vertical angle of incidence. The primary light can simultaneously enter the movable mirror at a second angle of incidence relative to the surface normal of the movable mirror. This second angle of incidence is here understood in particular as a horizontal angle of incidence. The advantage of this configuration is that it also avoids significant angular rotations of the orientation vector of the illumination pattern that differ from 0° or 90°.

[0011] In another advantageous configuration of the invention, both the first extension dimension and the second extension dimension are greater than 7 mm. The advantage of this configuration is that the extension dimension of the illumination pattern is therefore larger than the pupil of the eye. It is possible to emit primary light with higher energy and thus a greater effective range using the transmitting unit, while still meeting eye safety requirements. The size of the extension dimension also does not conflict with the small structural size of the lidar sensor having such a transmitting unit. On the contrary, it is possible to achieve a lidar sensor with a side length of less than 20 cm using the current transmitting unit.

[0012] In another advantageous configuration of the invention, a movable mirror is configured to scan the primary light along a first direction at an angle greater than ±3° within the field of view. The advantage of this configuration is that it can scan the largest possible field of view. This also enables uniform illumination of the field of view.

[0013] In another advantageous configuration of the invention, the transmitting unit has a first and at least one second transmitter unit. The first transmitter unit is configured to emit primary light in the form of a first illumination pattern. The second transmitter unit is configured to emit primary light in the form of a second illumination pattern. The first and second illumination patterns can be similar or nearly identical in their extended scale and spatial orientation. Here, the first transmitter unit is configured to scan a first segment of the field of view. The second transmitter unit is configured to scan a second segment of the field of view. The first segment of the field of view can be directly adjacent to the second segment of the field of view. The first and second segments of the field of view can at least partially overlap. The illumination pattern emitted by the first transmitter unit can be adjacent to or overlap with the illumination pattern emitted by the second transmitter unit. The advantage of this configuration is that it can scan a larger field of view.

[0014] In another advantageous configuration of the invention, a first steering mirror is configured to direct primary light emitted by the first transmitter unit and at least one second transmitter unit onto a movable mirror. Thus, not only the primary light emitted by the first transmitter unit but also the primary light emitted by at least one second transmitter unit can be directed by the first mirror. This configuration has the advantage of keeping the structural size of the transmitting unit small, and consequently, the structural size of the lidar sensor can also be kept small.

[0015] In another advantageous configuration of the invention, the transmitting unit further includes at least one second first steering mirror, wherein the first steering mirror is configured to redirect primary light emitted by the first transmitter unit onto a movable mirror; and wherein the at least one second first steering mirror is configured to redirect primary light emitted by the at least one second transmitter unit onto a movable mirror. The at least one second first steering mirror can be configured to be immovable. The advantage of this configuration is that the arrangement of additional optical elements of the first and second transmitter units and the transmitting unit can be more flexible.

[0016] In another advantageous configuration of the invention, the transmitting unit has at least one second steering mirror, wherein the second steering mirror is configured to redirect primary light emitted by the transmitting unit onto the first steering mirror when the orientation vector is rotated by a first angle, and wherein the first steering mirror is further configured to redirect the primary light onto a movable mirror when the orientation vector is rotated by a second angle; and wherein the first angle and the second angle are different from 0° and 90°, respectively. The second steering mirror can be configured to be immovable. As an alternative to the second steering mirror, the transmitting unit can also have other second steering elements. Such second steering elements can be, for example, prisms or diffractive optical elements with steering functions. The advantage of this configuration is that it allows for better realization that at least one orientation vector of the illumination pattern is oriented perpendicular to the first direction and parallel to the second direction when leaving the lidar sensor. It is more effective to avoid angular rotation of the orientation vector to angles significantly different from 0° or 90°. For example, one of the steering mirrors can be configured to compensate for angular rotations different from 0° or 90° that occur on the other steering mirrors. For example, the first steering mirror can be configured to compensate for angular rotations other than 0° or 90° occurring on the second steering mirror. Similarly, the second steering mirror can be configured to compensate for angular rotations other than 0° or 90° occurring on the first steering mirror. Particularly preferably, one of the steering mirrors can be configured to counteract angular rotations other than 0° or 90° occurring on the other steering mirrors.

[0017] In a particularly preferred configuration of the invention, the transmitting unit has at least one third steering mirror, which is arranged in the optical beam path of the transmitting unit between the second and first steering mirrors such that primary light, deflected by the second steering mirror, is incident on the third steering mirror, and wherein the third steering mirror is configured to deflect the primary light onto the first steering mirror with a third angle of rotation of the orientation vector, and wherein the third angle is different from 0° and 90°. Alternatively, the transmitting unit can also have other third steering elements. Such third steering elements can be, for example, prisms or diffractive optical elements with steering functions. The third steering mirror can be configured to be immovable. This makes it possible to compensate for angular rotations other than 0° or 90° by means of more than two steering mirrors. This advantageously achieves greater flexibility in the structure of the transmitting unit.

[0018] The present invention also relates to a lidar sensor for optical field detection, the lidar sensor having a transmitting unit as described above and at least one detector unit for detecting secondary light reflected and / or scattered by an object in the field of view.

[0019] The detector unit can be configured as a single-photon detector unit. A single-photon detector unit can have at least one single-photon detector. At least one single-photon detector can be configured, for example, as a SPAD (Single Photon Avalanche Diode) or a SiPM (Silicon Photon Multiplier). A SiPM detector unit, especially in a special circuit, has multiple SPADs. The single-photon detector unit is configured for single-photon counting. A single-photon detector unit can have multiple single-photon detector cells. A single-photon detector unit can, for example, be configured as a one-dimensional arrangement of multiple single-photon detector cells. The single-photon detector unit can be constructed using BSI (backside illumination) technology. For this purpose, each single-photon detector cell can be arranged with a degree of seamlessness on a very small chip surface. The detector unit is particularly configured for detecting a detection pattern identical to the illumination pattern. The detector unit here specifically receives secondary light from a predetermined segment of the field of view into which primary light has previously been emitted by the transmitter unit. The emission of primary light and the reception of secondary light preferably occur simultaneously through the predetermined segment of the field of view.

[0020] The optical paths of the transmitting unit and the detector unit can extend biaxially, coaxially, or partially coaxially to each other.

[0021] The lidar sensor also includes at least one analysis and processing unit. This unit is configured to determine the light propagation time of the emitted primary light and the subsequently received secondary light. The distance between the lidar sensor and an object in the field of view can be determined, for example, based on the time of flight (TOF). Time-of-flight methods include pulse methods or phase methods, where the pulse method determines the reception time of the reflected laser pulse, and the phase method emits an amplitude-modulated light signal and determines the phase shift relative to the received light signal. Time-correlated single-photon counting (TCSPC) can be implemented for ToF systems.

[0022] The present invention also relates to a method for emitting primary light into the field of view of a lidar sensor. The method includes the step of emitting primary light in the form of an illumination pattern by means of an emitting unit, wherein the illumination pattern has at least first and second extension scales, the first and second extension scales being orthogonally oriented to each other, and wherein the first extension scale is greater than or less than the second extension scale, and wherein the emitted illumination pattern is oriented along an orientation vector parallel to the first extension scale. In another step, the primary light emitted by the emitting unit is incident on a first steering mirror at a first incident angle of less than ±12°, preferably less than ±9°, particularly preferably less than ±7°, relative to the surface normal of a first steering mirror. In another step, the primary light is directed onto a movable mirror by means of the first steering mirror. In yet another step, the primary light is scanned in the field of view along a first direction and along a second direction oriented perpendicular to the first direction by means of the movable mirror.

[0023] It is understood that, without departing from the scope of the present invention, the features mentioned above and the features to be described below can be used not only in the combination described separately, but also in other combinations or individually. Attached Figure Description

[0024] Embodiments of the invention are described in more detail below with reference to the accompanying drawings. The same reference numerals in the drawings denote the same elements or elements having the same effect. The drawings show:

[0025] Figure 1 Example of a transmitting unit, wherein the orientation vector of the illumination pattern is rotated;

[0026] Figure 2: A: Ideal illumination of the field of view of the lidar sensor, and B: Real illumination of the field of view of the lidar sensor;

[0027] Figure 3: A: An embodiment of a transmitting unit with an advantageous arrangement of a first steering mirror is shown in overview form; B: Details.

[0028] Figure 4 Another embodiment of the transmitting unit with an advantageous arrangement of a first steering mirror;

[0029] Figure 5: A: Illumination pattern of the first transmitter unit, and B: Illumination pattern of the second transmitter unit;

[0030] Figure 6 Another embodiment of the transmitting unit with an advantageous arrangement of a first steering mirror;

[0031] Figure 7 One embodiment of a lidar sensor having a transmitting unit, the transmitting unit having an advantageous arrangement of a first steering mirror;

[0032] Figure 8 Another embodiment of the transmitting unit with an advantageous arrangement of a first steering mirror;

[0033] Figure 9 Another embodiment of the transmitting unit with an advantageous arrangement of a first steering mirror;

[0034] Figure 10 An embodiment of a method for emitting primary light into a field of view; and

[0035] Figure 11: Possible orientation vectors of the illumination pattern. Detailed Implementation

[0036] Figure 1 An exemplary transmission unit 100 for a lidar sensor is shown, the transmission unit being used to transmit primary light 102 into a field of view 106. The transmission unit 100 includes a first transmitter unit 101-1 and a second transmitter unit 101-2, a steering mirror 103, and a movable mirror 104. The first transmitter unit 101-1 and the second transmitter unit 101-2 are configured to transmit primary light 102-1 in the form of a first illumination pattern 107-1 and to transmit primary light 102-2 in the form of a second illumination pattern 107-2. In the example shown here, illumination patterns 107-1 and 107-2 are respectively constructed as lines oriented along orientation vector 108-1 or orientation vector 108-2. Primary beams 102-1 and 102-2 emitted by transmitter units 101-1 and 101-2 are directed onto a steering mirror 103, which is configured to redirect the primary beams 102-1 and 102-2 onto a movable mirror 104. The movable mirror 104 is configured to scan the primary beams 102-1 and 102-2 within a field of view 106 along a first direction x and a second direction y oriented perpendicular to the first direction x. The movable mirror 104 can scan the field of view 106 by moving along its two axes 105-1 and 105-2. The movable mirror 104 is configured such that it can redirect the primary light 102-1 to scan the first segment 106-1 of the field of view 106; and the movable mirror can redirect the primary light 102-2 to scan the second segment 106-2 of the field of view 106. Figure 1 As can be seen, the orientation vectors 108-1 and 108-2 are no longer perpendicular to and parallel to the first direction x or the second direction y. This leads to the problem that becomes clear in Figure 2.

[0037] Figure 2A This illustrates ideal illumination 200-A of the field of view illuminated by the transmitting unit using a lidar sensor. If... Figure 1If the orientation vectors 108-1 and 108-2 are oriented parallel to or perpendicular to the first direction x or the second direction y, then this gapless illumination 200-A can be achieved. Here, line 201-A indicates, for example, in... Figure 1 The movable mirror 104 moves along its axis 105-2 in the forward direction, scanning parallel to the x-axis. Line 201-B indicates a scan parallel to the x-axis during the movable mirror 104's movement along its axis 105-2 in the backward direction. After line 201-A is scanned along the forward direction, the movable mirror 104 moves along its axis 105-1 such that line 202-A is shifted along the y-axis with respect to the previously scanned line 201-A. After line 201-B is scanned along the backward direction, the movable mirror 104 moves along its axis 105-1 such that line 201-A is shifted along the y-axis with respect to the previously scanned line 202-A. In this way, the entire field of view 106 can be scanned by means of the movement of the movable mirror 104. The field of view 106 can be scanned in a grid pattern. Alternatively, it can also be understood as follows: Figure 2A That is, not only line 201-A but also line 202-A indicate, for example, in Figure 1 The movable mirror 104 performs a scan parallel to the x-axis during its movement along the forward direction on its axis 105-2. When moving along the backward direction, no primary light is emitted in this case. In this alternative, the movable mirror 104 can, for example, move in a zigzag pattern.

[0038] on the contrary, Figure 2B This illustrates the actual illumination 200-B of the field of view 106 illuminated by the transmitting unit 100 of the lidar sensor, as shown in... Figure 1 As shown in the diagram, gapless illumination can no longer be guaranteed due to the arrangement of the transmitter units 101-1 and 101-2, the steering mirror 103 and the movable mirror 104, and the resulting tilting of the orientation vectors 108-1 and 108-2. Because the orientation vectors 108-1 and 108-2 are rotated on the steering mirror by angles significantly different from 0° or 90°, unilluminated areas appear in the field of view 106. This problem may be amplified, especially in large fields of view. This poses a risk of overlooking small objects 203 within the field of view 106.

[0039] Figure 3AAn embodiment of a transmitting unit 300-A for emitting primary light 302-1 into a field of view 306 is shown, the transmitting unit being configured to prevent such problems. The transmitting unit 300-A has a transmitter unit 301-1 configured to emit primary light 302-1 in the form of an illumination pattern. Here, the illumination pattern has a first extension scale 311 and a second extension scale (not shown), the first and second extension scales being orthogonally oriented to each other. Here, the first extension scale 311 can be larger or smaller than the second extension scale. The emitted illumination pattern is also oriented along an orientation vector parallel to the first extension scale (see description of FIG. 5). The transmitting unit 300-A also has a first steering mirror 303-1 and a movable mirror 304. The first steering mirror 303-1 is configured to direct the primary light 302-1 onto the movable mirror 304. The movable mirror 304 is configured to scan the primary light 302-1 in the field of view 106 along a first direction (not shown here) and along a second direction 314 perpendicular to the first direction. In this example, the dashed line 310 marks the central optical axis of the output beam of the primary light 102-1 from the transmitting unit 300-A. The movable mirror 304 can be configured to scan the primary light 302-1 in the field of view 306 along the first direction at an angle greater than ±3°. The movable mirror 304 can also be configured to scan the primary light 302-1 in the field of view 306 along the second direction 314 at an angle 313 greater than ±3°.

[0040] Furthermore, the transmitting unit 300-A has an optical element 309-1. The optical element 309-1 can be, for example, an optical lens, a mirror, or a beam splitter. The illumination pattern can be constructed, for example, using the optical element 309-1. The optical element 309-1 can be configured alternatively or additionally for beam guidance.

[0041] exist Figure 3A The area marked with a box 318 in the middle Figure 3B The image is shown in magnified form. Here it can be seen that the first steering mirror 303-1 is arranged in the beam path of the primary light 302-1 such that the primary light 302-1 emitted by the transmitter unit 301-1 is incident at a first incident angle 312 of less than ±7° relative to the surface normal 317 of the first steering mirror 303. In the example shown here, the first incident angle 312 is 6°. For better illustration, the intermediate region between the primary light 302-1 incident on the steering mirror 303-1 and the primary light 302-1 deflected by the steering mirror 303-1 is shown as arrow 316. The first incident angle 312 relative to the surface normal 317 of the steering mirror 303-1 can here be understood in particular as a vertical incident angle. Furthermore, in Figure 3AAs can be seen, the primary light 302-1, which is deflected by the first deflecting mirror 303-1, can be incident at a first incident angle 315 of less than ±12° relative to the surface normal of the movable mirror 304. The first incident angle 315 relative to the surface normal of the movable mirror 304 can be understood here as the vertical incident angle.

[0042] Since the angle of incidence 312 relative to the surface normal 317 of the first steering mirror 303 is less than ±7°, it is possible to achieve that the orientation vector is rotated by only 0° or 90° by reflection on the first steering mirror. This is illustrated exemplarily in Figure 11. Figure 11A The diagram illustrates the possible orientation vectors of the illumination pattern and the angular rotation of these vectors upon reflection on a mirror. The mirror can be either the aforementioned steering mirror or the aforementioned movable mirror. The orientation vector can be parallel to the first plane, as schematically shown by line 706. The orientation vector can also be perpendicular to the plane, as schematically shown by circle 705. If the illumination pattern is now projected onto mirror 709 along direction 708-1, the illumination pattern can be reflected by mirror 709 onto direction 708-2. The orientation vector can be rotated by 0° or 90° through reflection on mirror 709. In this case, the orientation vector, after reflection, is parallel to the first plane, as schematically shown by line 711, or perpendicular to the plane, as schematically shown by circle 710. Figure 11B As shown, line 711, oriented parallel to the first plane, can have the same orientation as before reflection or can be rotated exactly 90°. This is indicated by lines 711-A and 711-B. If orientation vector 706 is parallel to the first plane before reflection, it may also be perpendicular to the first plane after reflection, and vice versa. This also corresponds to an angle rotation of 90°. In all these variations, it is possible to achieve as seamless as possible illumination of the field of view by means of the transmitting unit. Other angular rotations, such as those significantly different from 0° or 90°, can be avoided. Figure 11B As exemplarily shown by centerline 707, rotation by the angle will result in unlit areas appearing in the field of view.

[0043] The embodiment in Figure 3 can be understood as a transmitting unit having only one transmitter unit 301-1. Alternatively, the embodiment in Figure 3 can also be understood as a side view of a transmitting unit having at least two transmitter units (301-1 and 301-2), as shown, for example, in [the figure]. Figure 4 As shown in the diagram.

[0044] Figure 4Another embodiment of the transmitting unit 300-B is shown. Here, the structure of the transmitting unit 300-B is similar to that of the transmitting unit 300-A in FIG. 3, therefore the differences will be mainly discussed below. In addition to the transmitter unit 301-1, optical element 309-1, first steering mirror 303-1, and movable mirror 304 already described above, the transmitting unit 300-B also has a second transmitter unit 301-2, configured to emit primary light 302-2 in the form of an illumination pattern. This illumination pattern also has at least a first extension scale and a second extension scale 401, which are orthogonally oriented to each other. Here, the first extension scale is also larger than or smaller than the second extension scale. The illumination pattern emitted by the transmitting unit 301-2 is also oriented along an orientation vector parallel to the first extension scale. The transmitting unit 300-B now has a second first steering mirror 303-2. The second first steering mirror 303-2 is configured to redirect the primary light 302-2 emitted by the second transmitter unit 301-2 onto the movable mirror 304. The second first steering mirror 303-2 is also arranged in the beam path of the primary light 302-2 such that the primary light 302-2 emitted by the transmitter unit 301-2 is incident at a first incident angle of less than ±12° relative to the surface normal of the second first steering mirror 303-2. The movable mirror 304 is configured to scan the primary light 302-2 in the field of view 306 along a first direction 403 and along a second direction perpendicular to the first direction. Thus, ultimately, not only the primary light 302-1 but also the primary light 302-2 is redirected into the field of view by the same movable mirror 304. The first segment 403-1 of the field of view 306 is scanned by means of the primary light 302-1. The second segment 403-2 of the field of view 306 is scanned by means of the primary light 302-2. Here, the movable mirror 304 can be configured to scan the primary light 302-1 at an angle 402-1 greater than ±3° along the first direction 403 in the field of view, particularly in the first segment 403-1. The movable mirror 304 can also be configured to scan the primary light 302-2 at an angle 402-2 greater than ±3° along the first direction 403 in the field of view, particularly in the second segment 403-2. Furthermore, the transmitting unit 300-B can have an optical element 309-2 in the beam path of the primary light 302-2, as exemplarily shown here.

[0045] exist Figure 4 The transmitting unit 300-B shown can also be understood as a top view of a transmitting unit having two transmitter units 301-1 and 301-2. A corresponding side view would be the transmitting unit 300-A shown in Figure 3. Figure 4The transmitting unit 300-B shown can also have more than two transmitter units. For example, the structure can be mirrored at dashed line 404. In this case, the transmitting unit 300-B will have four transmitter units, four first steering mirrors 303, four optical elements 309, and a common movable mirror 304.

[0046] Figure 5 shows the illumination pattern of the described transmitting unit 300, such as that it can be projected onto a screen at a distance of 100m from the corresponding transmitting unit. Figure 5A Irradiation pattern 507-1 is shown here, as it can be emitted by the first emitter unit 301-1. Irradiation pattern 507-1 has a first extension scale 501 and a second extension scale 502, which are orthogonally oriented to each other. In the example shown here, the first extension scale 501 is larger than the second extension scale 502. Here, the first extension scale 501 can be greater than 7 mm. The second extension scale 502 can also be greater than 7 mm. The emitted irradiation pattern 507-1 is oriented along an orientation vector 508-1. The orientation vector 508-1 is parallel to the first extension scale 501. Figure 5B An illumination pattern 507-2 with orientation vector 508-2 is shown, as it can be emitted by the second emitter unit 301-2 of the described transmitting unit 300. Orientation vector 508-1 is oriented parallel to the x-axis. Orientation vector 508-2 is also oriented almost parallel to the x-axis. Therefore, when primary light 302-1 is emitted by the transmitting unit 300, orientation vector 507-1 is rotated by only 0° or 90° in terms of reflection on the first steering mirror 303. When primary light 302-2 is emitted by the transmitting unit 300, orientation vector 507-2 is rotated by almost 0° or 90°. Thus, with the described transmitting unit 300, the field of view 306 can be illuminated as seamlessly as possible.

[0047] As another embodiment, Figure 6 Showing with Figure 3AThe transmitting unit 300-A is similar to the transmitting unit 300-C. Only the differences will be discussed below. In addition to the first steering mirror, designated 303-A here, the transmitting unit 300-C also has a second steering mirror 303-B. The second steering mirror 303-B is configured here to redirect the primary light 302-1 emitted by the transmitting unit 301-1 onto the first steering mirror 303-A after the orientation vector is rotated by a first angle. The first steering mirror 303-A is configured to redirect the primary light 102-1 onto a movable mirror 304 after the orientation vector is rotated by a second angle. Here, the first and second angles are different from 0° and 90°, respectively. In the transmitting unit 300-C shown here, the first steering mirror 303-A is also arranged in the beam path of the primary light 302-1, such that the primary light 302-1 emitted by the transmitter unit 301-1 is incident at a first incident angle 312-A of less than ±12° relative to the surface normal 317 of the first steering mirror 303-A. In the example shown here, the angle 312-A is 8°. The primary light 302-1 emitted by the transmitter unit 101-1 can be incident at an incident angle 312-B of greater than ±12° relative to the surface normal of the second steering mirror 303-B. In the example shown here, the angle 312-B is 29°. Arrow 601 can indicate the extension dimension of the transmitting unit 300-C. For example, the dimension of the transmitting unit in this direction is 200 mm.

[0048] Figure 7 An embodiment of a lidar sensor 700 with transmitting units 300-D is shown. In the current example, the transmitting unit 300-D has four transmitter units 301. For simplicity, in Figure 7Only transmitter unit 301-1 is shown. Primary light 302-1 emitted by transmitter unit 301-1 passes through beam splitter 309-1-A and optical lens 109-1-B before hitting mirror 309-1-C. Mirror 309-1-C redirects primary light 302-1 onto another mirror 309-1-C via another optical lens 309-1-B. This other mirror 309-1-C redirects primary light 302-1 onto mirror 309-D. Mirror 309-D is configured to redirect primary light 302-1 through optical lens 309-1-B onto mirror 309-1-E. Here, the incident angles on mirrors 309-1-A, 309-1-C, 309-1-D, and 309-1-E are chosen such that the orientation vector rotates by only an angle close to 0° or 90° due to the corresponding reflections. Mirror 309-E-1 is further designed to redirect primary light 302-1 onto the first steering mirror 303 such that primary light 302-1 is incident on the first steering mirror 303 at a first incident angle of less than ±12° relative to the surface normal of the first steering mirror 303. The first steering mirror 303 is configured to redirect primary light 302-1 onto a movable mirror 304. The movable mirror is configured to scan primary light 102-1 in the field of view 306 along a first direction and along a second direction perpendicular to the first direction. Here, primary light 102-1 can pass through the front glass 703 of the lidar sensor 700. The beam path of the primary light from the additional transmitter unit (not shown here) corresponds to the beam path just described. Here, the transmitting unit 300-D has a mirror 309-D common to all primary light and a first steering mirror 303 common to all primary light. Conversely, other optical elements, such as mirrors 309-E-2 to 309-E-4, exist individually in each beam path. The lidar sensor 700 also has a detector unit 701 for detecting secondary light reflected and / or scattered by an object in the field of view 306. Figure 7 The detector unit 701 shown detects secondary light 704, the beam path of which extends largely coaxially with the primary light 302-1. At the beam splitter 309-1-A, the secondary light 704 is redirected onto the detector unit 701. The lidar sensor 700 can have additional detector units. The lidar sensor 700 particularly has additional detector units whose beam paths extend coaxially with the primary light emitted by three additional emitter units.

[0049] The 700 lidar sensor in Figure 7The components enclosed by frame 702 are arranged such that they protrude from the plane of the paper. Spatially, all unenclosed components are arranged within the plane of the paper. This particular configuration of the transmitting unit 300-D, or the lidar sensor 700, offers geometric advantages. In this configuration, the transmitting unit 300-D, or the lidar sensor 700, can be implemented more flat. This is especially advantageous if the lidar sensor is to be used in a small mounting location.

[0050] As another embodiment, Figure 8 The transmitting unit 300-E is shown. This transmitting unit is largely similar to... Figure 7 The transmitting unit 300-D is shown. For simplicity, the first part of the beam path is omitted here, and only the second part of the beam path, starting from mirror 309-D, is shown. Unlike the transmitting unit 300-D, the transmitting unit 300-E does not have a common mirror 309-D, but instead has individual mirrors 309-D-1 to 309-D-4 in the respective beam paths of the primary light emitted by the four transmitting units. The advantage of this configuration is that it does not require as much space in width as the transmitting unit 300-D, enabling the implementation of a smaller lidar sensor.

[0051] The transmitting unit, having a first steering mirror 303-A and a second steering mirror 303-B, can also have multiple transmitter units. This is, for example, by means of... Figure 9 The transmitting unit 300-F shown in the diagram illustrates this. The transmitting unit 300-F has a first transmitter unit 301-1 for emitting primary light 302-1 and a second transmitter unit 301-2 for emitting primary light 302-2. The emitted primary light 302-1 and 302-2 are directed onto a common steering mirror 303-B, which is configured to redirect the primary light 302-1 and 302-2 onto their respective first steering mirrors when the orientation vector is rotated by a first angle. Here, primary light 302-1 is redirected onto first steering mirror 303-A-1. Primary light 302-2 is redirected onto first steering mirror 303-A-2. The respective first steering mirrors 303-A-1 and 303-A-2 are also configured to redirect primary light 302-1, or 302-2, onto a movable mirror 304 when the orientation vector is rotated by a second angle. The first and second angles are different from 0° and 90°.

[0052] Figure 10An embodiment of a method 1000 for emitting primary light into a field of view is shown. The method begins at step 1001. In step 1002, primary light in the form of an illumination pattern is emitted by means of an emitter unit, wherein the illumination pattern has at least first and second extension scales, which are orthogonally oriented to each other. Here, the first extension scale is larger than or smaller than the second extension scale. Furthermore, the emitted illumination pattern is oriented along an orientation vector parallel to the first extension scale. In another step 1003, the primary light emitted by the emitter unit is incident on the first steering mirror at a first incident angle of less than ±12°, preferably less than ±9°, and particularly preferably less than ±7° relative to the surface normal of the first steering mirror. In another step 1004, the primary light is directed onto a movable mirror by means of the first steering mirror. In step 1005, the primary light is scanned in the field of view along a first direction and along a second direction oriented perpendicular to the first direction by means of the movable mirror. The method ends at step 1006.

Claims

1. A transmitting unit for a lidar sensor (700), the transmitting unit being configured to transmit primary light (302) into the field of view (306) of the lidar sensor (700), the transmitting unit comprising: At least one emitter unit (301) configured to emit primary light (302) in the form of an illumination pattern (507), wherein, The illumination pattern (507) has at least a first extension scale (311, 501) and a second extension scale (401, 502), the first extension scale and the second extension scale being orthogonally oriented to each other, wherein the first extension scale (311, 501) is greater than or less than the second extension scale (401, 502), and wherein the emitted illumination pattern (507) is oriented along an orientation vector (508) parallel to the first extension scale (311, 501); and At least one first steering mirror (303) and at least one movable mirror (304); in, The first steering mirror (303) is configured to direct the primary light (302) onto the movable mirror (304); wherein, The movable mirror (304) is configured to scan the primary light (302) in the field of view (306) along a first direction (403) and along a second direction (314) perpendicular to the first direction; and wherein, The first steering mirror (303) is arranged in the beam path of the primary light (302) such that the primary light (302) emitted by the transmitter unit (301) is incident at a first incident angle (312) greater than -12° and less than +12° relative to the surface normal (317) of the first steering mirror (303).

2. The transmitting unit according to claim 1, wherein, The movable mirror (304) is arranged in the beam path of the primary light (302) such that the primary light (302) deflected by the first deflecting mirror (303) is incident at a first incident angle (315) greater than -12° and less than +12° relative to the surface normal of the movable mirror (304).

3. The transmitting unit according to claim 1 or 2, wherein, The first extension dimension (311, 501) is greater than 7 mm, and the second extension dimension (401, 502) is greater than 7 mm.

4. The transmitting unit according to claim 1 or 2, wherein, The movable mirror (304) is configured to scan the primary light (302) in the field of view (306) along the first direction (403) at an angle greater than +3° or less than -3°.

5. The transmitting unit according to claim 1 or 2, wherein, The transmitting unit has a first transmitter unit (301-1) and at least one second transmitter unit (301-2).

6. The transmitting unit according to claim 5, wherein, The first steering mirror (303) is configured to direct primary light (302-1, 302-2) emitted by the first emitter unit (301-1) and by the at least one second emitter unit (301-2) onto the movable mirror (304).

7. The transmitting unit according to claim 5, wherein the transmitting unit further comprises at least one second first steering mirror (303-2); and wherein, The first steering mirror (303-1) is configured to redirect the primary light (302-1) emitted by the first transmitter unit (301-1) onto the movable mirror (304); and wherein the at least one second first steering mirror (303-2) is configured to redirect the primary light (302-2) emitted by the at least one second transmitter unit (301-2) onto the movable mirror (304).

8. The transmitting unit according to claim 1 or 2, wherein the transmitting unit has at least one second steering mirror (303-B), wherein, The second steering mirror (303-B) is configured to redirect the primary light (302) emitted by the transmitter unit (301) onto the first steering mirror (303), wherein the orientation vector (508) is rotated by a first angle, and wherein the first steering mirror (303) is also configured to redirect the primary light (302) onto the movable mirror (304), wherein the orientation vector (508) is rotated by a second angle; and wherein the first angle is different from 0° and 90°, and the second angle is different from 0° and 90°.

9. The transmitting unit according to claim 1, wherein, The first incident angle is greater than -9° and less than +9°.

10. The transmitting unit according to claim 9, wherein, The first incident angle is greater than -7° and less than +7°.

11. A lidar sensor (700) for optically detecting a field of view, the lidar sensor having: The transmitting unit according to any one of claims 1 to 10; and At least one detector unit (701) is used to detect secondary light (704) reflected and / or scattered by an object in the field of view.

12. A method (1000) for emitting primary light into a field of view using a lidar sensor, the method comprising the following steps: A primary light in the form of an illumination pattern is emitted by a transmitter unit (1002), wherein, The illumination pattern has at least a first extension scale and a second extension scale, the first extension scale and the second extension scale are orthogonally oriented to each other, wherein the first extension scale is greater than or less than the second extension scale, and wherein the emitted illumination pattern is oriented along an orientation vector parallel to the first extension scale. The primary light emitted by the transmitter unit is incident on the first steering mirror at a first incident angle greater than -12° and less than +12° relative to the surface normal of the first steering mirror (1003); The primary light is directed (1004) onto the movable mirror by means of the first steering mirror; Using the movable mirror, the primary light is scanned (1005) in the field of view along a first direction and along a second direction oriented perpendicular to the first direction.

13. The method according to claim 12, wherein, The first incident angle is greater than -9° and less than +9°.

14. The method according to claim 13, wherein, The first incident angle is greater than -7° and less than +7°.

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