Device for measuring distance and method for its manufacture

Abstract

A device (14) for distance measurement comprises a light source (16), a photonically integrated circuit (50) which includes an arrangement of free-space couplers (40) and is rigidly attached to a support (54), and a deflection optic (44) in whose focal plane (43) the free-space couplers (40) are arranged. The deflection optic (44) is rigidly attached to a mount (52) which has a flange (62) with a circumferential outer surface (63). According to the invention, the flange (62) is welded to the support (54) at several weld points (80) which are radially offset inwards from the outer surface (63). This reduces the impact of any distortion of the components associated with the welding process on their alignment.

Description

BACKGROUND OF THE INVENTION 1. Field of the invention

[0001] The invention relates to a distance measuring device comprising a photonic integrated circuit (PIC) and a deflection optic. Such devices can be used, for example, in autonomous vehicles. The invention also relates to a method for manufacturing such a device and, in particular, to fixing the position of the photonic integrated circuit relative to the deflection optic after the two components have been aligned. 2. Description of the state of the art

[0002] For optical distance measurement, a measurement principle known as FMCW LiDAR is known, in which optical signals with a time-varying frequency (FMCW stands for frequency-modulated continuous wave) are directed from a measuring device in different directions towards an object to be measured. After reflection from the object, the signals return to the measuring device and are superimposed with a signal that was either not emitted or reflected by a reflector at a known distance and is therefore called the local oscillator (LO). Due to the path traveled by the light, the signal reflected from the object has a slightly different frequency than the LO signal. When the two signals are superimposed, a low-frequency beat frequency is generated, which is detected by a detector in the measuring device and used to calculate the distance between the measuring device and the object.If the Doppler shift is also taken into account, the relative velocity between the measuring device and the object can also be calculated.

[0003] Measuring devices based on this principle must be very robust and reliable if they are to be used in motor vehicles. This is especially true for autonomous vehicles, as safety in autonomous driving depends crucially on how reliably a sufficiently high-resolution three-dimensional image of the environment can be generated.

[0004] Therefore, at least for scanning in horizontal planes, measuring devices that do not require rotating scan mirrors or other moving components are preferred. US 2021 / 0316756 A1 and US 11,009,593 B1 disclose architectures for the photonically integrated circuit in which a distribution matrix with several tree-like active switches and / or passive splitters distributes the FMCW signals to different free-space couplers. A deflection optic, in whose focal plane the free-space couplers are arranged, collimates the optical signals emerging from the free-space couplers and radiates them in different directions.

[0005] To ensure proper functioning, the photonic integrated circuit with the free-space couplers must be precisely aligned and fixed in position relative to the deflection optics. If the alignment is inaccurate from the outset or becomes inaccurate after a certain period of operation, this can lead, for example, to objects being detected seemingly in locations where they are not. This is because even a slight lateral displacement of a free-space coupler from its intended position results in a change in the beam angle. At distances of 300 m and more, even the smallest angular changes translate into deviations of several meters. Tilting of the deflection optics relative to the photonic integrated circuit can lead to inadequate collimation and thus to a reduced range and / or spatial resolution.

[0006] Precise alignment can be achieved with known optical measuring devices in an active adjustment process with reasonable effort. However, the problem of maintaining this alignment over the long term, despite the high mechanical and thermal stresses to which such measuring devices are subjected in vehicles, remains unsatisfactorily solved. Therefore, an age-resistant yet cost-effective positioning fix between the photonically integrated circuit and the deflection optics is required.

[0007] Similar problems arise with camera sensors, which must be aligned and fixed in position relative to a lens. Various fastening techniques are known in the prior art for fixing the position of camera sensors, including screwing, welding, soldering, and gluing.

[0008] German patent DE 10 2016 208 547 A1 concerns a camera module for a motor vehicle and proposes bonding to attach a sensor carrier to a lens holder. However, adhesive bonds have low thermal and chemical resistance. If the mechanical properties of the bond are temperature-dependent, changes in lens alignment and thus functional impairments can occur at varying ambient temperatures. Furthermore, adhesive bonds are often not age-resistant, as most adhesives tend to deform over time (so-called "creep").

[0009] Therefore, DE 10 2019 216 283 A1, in connection with camera modules for motor vehicles, proposes welding the lens holder to a carrier of the image sensor after the lens has been aligned relative to the image sensor. While welded joints are mechanically and thermally stable and highly resistant to aging, the components often warp relative to each other during welding due to the high heat input. This warping can impair the precise alignment between the lens and the image sensor and thus negatively affect the function.

[0010] Similar problems arise when a soldered connection is chosen instead of a welded one.

[0011] According to the German patent application DE 10 2024 101 761.9, filed on January 22, 2024, and still unpublished, the bracket for the deflection optics is first bonded to the carrier after alignment and then welded. The bonding prevents the alignment from being affected by the welding. The welding, in turn, ensures very good aging resistance, which is why this approach is superior to bonding alone. This two-stage process has proven very successful, but requires more effort in manufacturing due to the two different process steps of bonding and welding. SUMMARY OF THE INVENTION

[0012] The object of the invention is to provide a device for distance measurement characterized by a precise and age-resistant, yet easily manufactured, position fixation between a photonically integrated circuit relative to a deflection optic. The object of the invention is also to provide a method for manufacturing such a device.

[0013] With regard to the device, the problem is solved by a distance-measuring device that has a light source configured to generate an optical signal. The device also includes a photonically integrated circuit comprising an arrangement of free-space couplers, each configured to emit the optical signal into the surrounding free space. A deflection optic has a focal plane in which the free-space couplers are arranged, with an optical axis of the deflection optic defining an axial direction. The device further comprises a carrier to which the photonically integrated circuit is rigidly attached, and a mount to which the deflection optic is rigidly attached and which has a flange with a circumferential outer surface. According to the invention, the flange of the mount is welded to the carrier at several weld points that are radially offset inwards from the outer surface.

[0014] The inventor recognized that the aforementioned problem with welding—namely, a loss of alignment due to temperature-induced deformation of one or both workpieces—can be significantly reduced by offsetting the weld points radially inwards. When welding a flange to a beam or other plate-like workpiece, the usual procedure is to apply a continuous weld or several individual weld points along the circumferential joint between the flange and beam where the two parts meet. When heat is introduced to the circumferential outer surface during the welding process, the resulting deformations cause the flange and beam to begin to gape apart on the opposite side, similar to an opening seashell.Even if the deformations are minimal and the widening of the butt joint is often barely visible to the naked eye, they can be easily measured and cause an alignment that has been set to be lost as soon as the first weld is made.

[0015] However, if the weld points are positioned radially inwards, i.e., towards the optical axis of the deflection optics, as described in the invention, the widening of the butt joint is significantly smaller due to the resulting more symmetrical deformation and stress distribution. The effect of the resulting distortion on the alignment can be so minimal that the alignment can be considered maintained within the required accuracy range. If, in cases of particularly high accuracy requirements, the alignment must be considered lost after the first weld point has been applied, it can be subsequently corrected by simple measures, such as a judicious selection of locations for further weld points.

[0016] In accordance with common usage, a flange is defined here as a projecting element, preferably extending at right angles to the axial direction, that connects a beam and a support, with the flange and beam abutting flush. Flanges are often annular and rotationally symmetrical with respect to the axial direction. However, flanges with an outer surface having an oval or polygonal contour in horizontal section are also possible, as are flanges that extend only along specific directions from the axial direction, forming, for example, a cloverleaf-like arrangement. The flange can be integrally formed with the support or rigidly connected to a hollow cylinder or another part of the support. The connection between the flange and the other part of the support can be achieved, for example, by threading, gluing, soldering, or welding.

[0017] By moving the weld points away from the outer surface of the flange, special access points for the welds must be created. One option is to provide the flange and the support with radially extending and corresponding grooves. When the flange and support are joined, radially extending, channel-like recesses are created where the grooves meet. If a laser beam is directed into such a channel-like recess, a weld point can be created at the bottom of the recess, offset radially inwards from the outer surface, possibly after a filler material, e.g., a spherical one, has been inserted into the channel.

[0018] One disadvantage of such internally hidden weld points is that they are difficult to access, which also leads to difficulties in the metrological monitoring and verification of the welding process.

[0019] It is therefore preferred that the flange has openings on the inner surfaces of which the welds are formed. In the area of ​​the openings, the beam adjacent to the flange is directly accessible, allowing the welds to be easily made and inspected. The openings are preferably distributed around the circumference of the flange at equal distances from the axis of symmetry. The openings can, for example, have a circular, polygonal, or ring-segment shape.

[0020] In the simplest case, the openings have a longitudinal axis parallel to the axial direction, causing the inner surfaces of the openings to be perpendicular to a surface of the beam. The weld points are then located in the circumferential edges formed by the inner surfaces of the openings and the surface of the beam. In principle, however, openings whose longitudinal axis is inclined to the axial direction are also possible.

[0021] In a preferred embodiment, the support has projections in the area of ​​the openings that extend into the openings. Gaps remain between the inner surfaces of the openings and the outer surfaces of the projections, the width of which decreases along the axial direction towards the support. These gaps, formed by the projections, make it possible to position the weld points at locations where the surfaces to be welded form an angle of less than 90°, yet are still easily accessible. It has been found that welding in such tapered gaps is particularly easy to control. Furthermore, since the surfaces to be welded are closely adjacent, less heat needs to be supplied for melting during the welding process, resulting in less deformation of the components involved.

[0022] Gaps with decreasing width can be defined by arranging the inner surfaces of the openings and / or the outer surface of the protrusions at an angle to the axial direction. For reasons of symmetry, an opposite but equal inclination of both surfaces is preferred. In particular, the openings and protrusions can have the form of oppositely oriented, right truncated cones, with the protrusions centered in the openings. Openings and protrusions designed in this way define circumferential gaps whose width tapers continuously towards the support.

[0023] Filler materials can be placed in the gaps of decreasing width. These materials are inserted into the gaps before welding and, after welding, connect the openings with the protrusions. In the case of circumferential and tapered gaps, such as those formed by frustoconical openings and protrusions, the filler materials can be added, for example, in the form of small spheres that circulate within the gaps and can be freely positioned. The use of filler materials has the advantage that the material for bridging the gap does not need to be taken from the parts being joined. This reduces the tendency of the parts to deform during welding and thus affect their alignment.

[0024] The openings and protrusions can also reverse their roles. This means that the support, rather than the flange, has openings on whose inner surfaces the weld points are formed. Preferably, protrusions are then formed on the flange in the area of ​​the openings, projecting into them. Here, too, gaps remain between the inner surfaces of the openings and the outer surfaces of the protrusions, but their width decreases along the axial direction towards the flange. The welding is then carried out from the opposite side.

[0025] In one embodiment, the device includes a detector configured to detect the superposition of an optical signal generated by the light source, which was not reflected by the object being measured, with an optical signal reflected by the object being measured. An evaluation unit is configured to determine the distance to the object from the superposition detected by the detector. Such a device operates according to the aforementioned FMCW principle, which is significantly more efficient than conventional devices that operate according to the time-of-flight principle.

[0026] With regard to the method, the problem is solved by a method for manufacturing a device for measuring distance, wherein the method comprises the following steps: a) Providing a light source designed to produce an optical signal; b) rigidly fixing a deflection optic in a holder having a flange with a circumferential outer surface; c) rigidly mounting a photonically integrated circuit to a support, wherein the photonically integrated circuit comprises an arrangement of free-space couplers, each configured to emit the optical signal generated by the light source into the surrounding free space; d) Aligning the mount and the support relative to each other such that the free-space couplers are arranged in a focal plane of the deflection optics; and e) Welding the flange of the bracket to the support at several weld points that are radially offset inwards from the outer surface of the flange.

[0027] In a preferred embodiment, the flange has openings, and the support has projections in the area of ​​the openings that extend into the openings, leaving gaps between the inner surfaces of the openings and the outer surfaces of the projections. The width of these gaps decreases along the axial direction towards the support. A filler material, which may be spherical, for example, can be filled into these gaps before welding. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Exemplary embodiments of the invention are explained in more detail below with reference to the drawings. These show: Fig. 1 a schematic side view of a vehicle approaching an object that is detected by a measuring device according to the invention; Fig. 2 a top view of the in the Fig. 1 measuring device shown; Fig. 3. The construction of the measuring device according to an exemplary embodiment in a schematic representation; Fig. 4 a graph showing the frequency of the emitted optical signals over time; Fig. 5 a switching matrix and the deflection optics of the in the Fig. 3 measuring device shown; Fig. 6 a schematic longitudinal section through the housing of the measuring device with the photonically integrated circuit enclosed therein; and Fig. 7 a perspective view of parts of the in the Fig. 6 Measuring device shown during welding using a laser beam. DESCRIPTION OF PREFERRED EXECUTION EXAMPLES 1. Application Example

[0029] The Fig. Figure 1 shows a schematic side view of a vehicle 10 approaching an object 12, which is located in the Fig. The object 12 is a tree. The vehicle 10 is equipped with a measuring device 14 that uses light beams L11, L21, L31, and L41 to scan the area in front of the vehicle 10 in order to obtain distance values. A three-dimensional image of the surroundings is reconstructed from these distance values. The measuring device 14 also determines the relative speed to the object 12. This information is particularly important if the object 12 is another vehicle or an animal and is also moving.

[0030] The information about the vehicle 10's surroundings, as determined by the measuring device 14, can be used, for example, to assist the driver of the vehicle 10 in controlling the vehicle by generating warning messages when a collision between the vehicle 10 and the object 12 is imminent. If the vehicle 10 is driving autonomously, the information about the surroundings is required by the control algorithms that control the vehicle 10.

[0031] As in the Fig. As can be seen, the measuring device 14 emits in a vertical plane (in the Fig. (1. This is the paper plane) the light rays L11 to L41 are directed in different directions, thus scanning the surroundings vertically. Simultaneously, scanning also takes place in a horizontal direction, as described by the Fig. Figure 2 shows a top view of the measuring device 14. Four light beams L11, L12, L13 and L14 are shown, emitted in different directions in a horizontal plane.

[0032] For the sake of clarity, the following is included: Fig. 1 and Fig. 2 assumes that only four light beams Ln1 to Ln4 each in four different planes, i.e., a total of 16 light beams, are generated by the scanning device 14. Preferably, the measuring device 14 emits many more light beams. Preferably, for example, k·2 n Light rays, where n is a natural number between 7 and 13 and indicates how many rays are emitted in one of k planes, where k is a natural number between 1 and 16. 2. Measuring device

[0033] The Fig. Figure 3 schematically shows the setup of the measuring device 14 according to an embodiment of the invention. The measuring device 14 is designed as a LiDAR system and comprises an FMCW light source 16 which, during operation of the measuring device 14, emits measuring light with a varying frequency f. chirp generated. How the Fig. 4 illustrates how the frequency f varies (“chirps”). chirp periodically over time t between a lower frequency f l and a higher frequency f h .

[0034] Each measurement interval with a chirp duration T is divided into two halves of equal length T / 2. During the first interval, the frequency f increases. chirp linear with a constant and positive upchirp rate r chirp , dh df chirp / dt = r chirp During the second interval, the frequency f decreases chirp linear with a constant negative downchirp rate -r chirp , dh df chirp / dt = -r chirpThe frequency of the measuring light can therefore be described by a periodic triangular function. However, other functional relationships are also possible, e.g., sawtooth functions.

[0035] As from the Fig. As shown in Figure 3, the light source 16 is connected to a splitter 22, which splits the measuring light into reference light (local oscillator) and output light. In the illustrated embodiment, the output light is amplified in an optical amplifier 24 and then passes to an optical circulator 26, which directs the amplified measuring light to a deflection unit 28. The optical circulator 26 can, for example, comprise a polarization-sensitive beam splitter that interacts with other polarization-optical elements, as is known in the prior art. Instead of the circulator, a 2x2 coupler can also be used, for example, but this leads to higher light losses.

[0036] The deflection unit 28 directs the output light onto the object 12 - in Fig. 3 represented by a moving car - along different directions, as shown above with reference to the Fig. 1 and Fig. As explained in section 2. The optical signal emitted by the deflection unit 28 is typically at least partially diffusely reflected by the object 12. A small portion of the reflected signal returns to the measuring device 14, where it couples back into the deflection unit 28.

[0037] The optical circulator 26 directs the coupled light onto a combiner 30, which superimposes the reference light, separated from the measuring light by the splitter 22, with the coupled light. Since the frequencies of the superimposed light components differ slightly from one another, a beat signal is generated, which is detected by a detector 32, preferably a symmetrical photodetector. The electrical signals generated by the detector 32 are fed to a processing unit 34, which calculates the distance R to the object and the relative velocity ν between the scanning device 14 and the object 12 from the analysis of beat frequencies.

[0038] The Fig. Figure 5 shows parts of the deflection unit 28 in a simplified schematic representation. The deflection unit 28 comprises an optical switching matrix M in which several optical switches S11, S21, and S22 are arranged in a tree-like configuration. Using the optical switching matrix M, optical signals received at an input 36 of the switching matrix M can be successively distributed to several output waveguides 38. For clarity, the optical switching matrix M in the illustrated embodiment has only three optical switches, so that a total of four output waveguides 38 can be controlled. In actual measuring devices 14, eight or more switching levels can be arranged in series, so that, for example, 256 output waveguides 38 can be selectively connected to the input 36.

[0039] In other embodiments, the switching matrix M is located before the amplifier 24 or between the amplifier 24 and the circulator 26. Alternative configurations for integrating switching matrices into the measuring device 14 can be found in the two documents already mentioned at the beginning, US 2021 / 0316756 A1 and US 11,009,593 B1.

[0040] The output waveguides 38 terminate in free-space couplers 40, which allow optical signals guided in the output waveguides 38 to be coupled into free space. Such couplers are known in the prior art and can, for example, be designed as grid couplers, which have a widening waveguide section to which a grid structure is attached. Alternatively, the free-space couplers 40 can be edge couplers, which have a higher coupling efficiency than grid couplers.

[0041] The free-space couplers, or more precisely their exit windows, are arranged in the focal plane 43 of a collecting deflection optic 44, which also belongs to the deflection unit 28 and in the Fig. 5 is indicated, for the sake of simplicity, only by a single lens. As in the Fig. As can be seen in Figure 5, the deflection optics 44 thus acts as a collimator, collimating the light beams emerging divergently from the free-space couplers 40 and emitting them in different directions. The further a free-space coupler 40 is positioned from the optical axis 45 of the deflection optics 44, the larger the angle at which the collimated optical signals are emitted by the deflection optics 44.

[0042] In the illustrated embodiment, the deflection unit 28 also serves to receive the optical signals reflected from the object 12. For this purpose, the reflected optical signals are coupled back into the output waveguides 38 via the free-space couplers 40. In other embodiments, the reflected signals are received by separate free-space couplers and fed to the detector 32 via separate waveguides.

[0043] At least the circulator 26, the combiner 30, the detector 32, the switching matrix M, and the output waveguides 38 with the end-end free-space couplers 40 are photonically integrated and arranged on a common substrate, thereby forming a photonically integrated circuit. In this embodiment, the free-space couplers 40 are arranged on a surface of the photonically integrated circuit and preferably distributed along a linear or two-dimensional grid. If the free-space couplers 40 are arranged in a one-dimensional, i.e., linear, configuration, an additional mechanical scanner can be arranged behind the deflection optics 44 to provide the second scanning direction.

[0044] The light source 16 and the amplifier 24 can be hybridly mounted as separate components on the circuit substrate, e.g., by flip-chip bonding. Alternatively, although technologically considerably more complex, these components can also be epitaxially fabricated on the common substrate. 3. Housing

[0045] The Fig. Figure 6 shows the photonically integrated circuit designated 50, the deflection optics indicated at 44, and a surrounding housing 51 in a schematic longitudinal section along the optical axis 45. The housing 51 comprises a holder 52 for the deflection optics 44 and a support 54, which has the form of a planar plate and carries the photonically integrated circuit 50.

[0046] In the illustrated embodiment, the bracket 52 is constructed in two parts and consists of a hollow cylinder 56 with an annular cross-section and an angled collar piece 58. The collar piece has a short hollow cylindrical section 60 into which the hollow cylinder 56 is inserted. The hollow cylinder 56 can be rigidly connected to the surrounding section 60 by screwing, gluing, soldering, or welding (not shown in the illustration). Fig. (Figure 6). A flange 62 is integrally formed on the hollow cylindrical section 60, with which the bracket 52 bears flat against the support 54. A circumferential outer surface of the flange 62 is designated 63.

[0047] The flange 62 is provided with several openings 66, the longitudinal axes of which run parallel to the optical axis 45. As can best be seen in the enlarged section 64, each opening 66 has the shape of a right truncated cone, the inner surface 68 of which is inclined to the optical axis 45. Projections 70, formed integrally with the top of the support 54, extend into the openings 66. Each projection 70 also has the shape of a right truncated cone and thus outer surfaces 72 inclined to the optical axis 45, with this truncated cone being oriented opposite to the openings 66. This leaves a tapered circumferential gap 74 between the inner surface 68 of an opening 66 and the outer surface 72 of a projection 70 centered therein. Tapered here means that the width of the gap 74 decreases along the optical axis 45 towards the support 54.In the illustrated embodiment, the inclinations of the inner surfaces 68 and the outer surfaces 72 are chosen symmetrically, whereby the circumferential gap 74 is V-shaped in cross-section, if one disregards the flat surface at the bottom of the gap 74.

[0048] Before welding, balls 76 made of a metallic filler material are inserted into the gap 74. Since the balls can rotate within the gap 74, they can be easily positioned and fixed in the desired position by light pressure. This condition is present in the Fig. 6 and in the perspective representation of the Fig. 7 reproduced, in which the arrangement of Fig. 6 without hollow cylinder 56 and deflection optics 44, but with a laser welding device 77 is shown.

[0049] If a laser beam 78 generated by the laser welding device 77 is directed at a sphere 76, as shown on the right in the Fig. As indicated in Figure 7, the heat introduced by absorption of the laser beam 78 causes the sphere 76 and the adjacent areas of the inner surface 68 and the outer surface 72 to melt. After solidification, the filler material of the sphere 76 forms a bridge-like structure in the cutout 64 of the Fig. 6. The weld 80 shown on the right connects the inner wall 68 of the opening 66 to the outer wall of the protrusion 70. After assembly, the measuring device 14 no longer contains any spheres 76, but only welds 80. 4. Assembly

[0050] During the assembly of the measuring device 14, the photonically integrated circuit 50 is rigidly attached to the carrier 54 and the deflection optics 44 are rigidly attached to the holder 52. The flange 62 of the holder 52 is then placed onto the carrier 54 such that the projections 70 formed on the carrier 54 are centered in the openings 66 of the flange 62. This allows the holder 52 to be aligned relative to the carrier 54 within certain limits.

[0051] Such alignment is necessary because, for the measuring device 14 to function correctly, the free-space couplers 40 contained in the photonically integrated circuit 50 must be located precisely in the focal plane 43 of the deflection optics 44. If this condition is not met, the light emerging from the free-space couplers 40 will not be precisely collimated, resulting in the measurement points becoming too large at greater distances. Furthermore, tilting of the measuring beams can occur, disrupting the correlation between the free-space couplers 40 and the scan direction.

[0052] The correct relative arrangement between the bracket 52 and the support 54 is achieved by an active alignment process. For this purpose, the photonically integrated circuit 50 can emit measuring beams, the propagation direction of which is detected behind the deflecting optics 44 by an external measuring device. The alignment typically occurs in all degrees of freedom, i.e., displacements along the three spatial directions x, y, z and rotations about these spatial directions.

[0053] After alignment, the flange 62 is welded to the support 54 in the manner already described above. Due to the weld points 80 being offset radially inwards from the outer surface 63, the distortion caused by the heat input, which is unavoidable during the welding process, is less than with conventional welding on the outer surface 63. In particular, there is only a slight widening of the butt joint 82 on the side opposite the weld point. Fig. 6, with the first weld 80 shown on the right, is the part of the butt joint shown on the left. If the effect of the distortion is so small that any deviations from the desired alignment can still be tolerated, further welds 80 are created by successively directing the laser beam 78 onto other spheres 76. As soon as deviations from the desired alignment can no longer be tolerated, subsequent welds must be selected more precisely. Tests have shown that, in some cases, even a further weld within the same gap 74 leads to a counteracting effect, which improves the alignment again. The locations and sequence in which welds 80 must be created depend on a multitude of parameters and can be easily determined through testing.

[0054] Based on the Fig. 6 and Fig. Figure 7 clearly shows that the openings 66 and the protrusions 70 can also exchange their roles, such that the openings are formed on the support 54 and the protrusions on the flange 62. In the Fig. 6 indicates such an opening and such a protrusion, respectively, by dashed lines 66' and 70'. The welding then does not take place as in the Fig. Figure 7 shows the view from above, not from below. A combination of openings / protrusions on different sides is also possible in principle, but not preferred, as welding would then have to be carried out from both above and below. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] US 2021 / 0316756 A1 [0004, 0039] US 11,009,593 B1 [0004, 0039] DE 10 2016 208 547 A1

[0008] DE 10 2019 216 283 A1

[0009] DE 10 2024 101 761.9

[0011]

Claims

[1] Device (14) for distance measurement, with a light source (16) which is configured to produce an optical signal, a photonically integrated circuit (50) comprising an arrangement of free-space couplers (40) each configured to emit the optical signal into the surrounding free space, a deflection optic (44) with a focal plane (43) in which the free-space couplers (40) are arranged, wherein an optical axis (45) of the deflection optic (44) defines an axial direction, a carrier (54) to which the photonically integrated circuit (50) is rigidly attached, and with a bracket (52) to which the deflecting optic (44) is rigidly attached and which has a flange (62) with a circumferential outer surface (63), characterized by, that the flange (62) of the bracket (52) is welded to the support (54) at several weld points (80) which are radially offset inwards from the outer surface (63). [2] Device according to claim 1, characterized by , that the flange (62) has openings (66) on whose inner surfaces (68) the weld points (80) are formed. [3] Device according to claim 2, characterized by , that on the support (54) in the area of ​​the openings (66) projections (70) are formed which project into the openings (66), and that gaps (74) remain between the inner surfaces (68) of the openings (6) and outer surfaces (72) of the projections (70), the width of which decreases along the axial direction towards the support (54). [4] Device according to claim 3, characterized by , that the openings (66) and the protrusions (70) have the form of oppositely oriented straight truncated cones, with the protrusions (70) being centered in the openings (66). [5] Device according to one of claims 3 or 4, characterized by , that there is an additional material (76) in the columns (74) which connects the openings (66) with the protrusions (70). [6] Device according to claim 1, characterized by , that the support (54) has openings (66') on the inner surfaces of which the weld points are formed. [7] Device according to claim 6, characterized by , that on the flange in the area of ​​the openings (66') protrusions (70') are formed which project into the openings (66'), and that gaps remain between the inner surfaces of the openings (66') and outer surfaces of the protrusions (70') the width of which decreases along the axial direction towards the flange. [8] Device according to any one of the preceding claims, characterized bya detector (32) which is configured to detect a superposition of an optical signal generated by the light source (16) that was not reflected by an object to be measured with an optical signal that was reflected by the object to be measured, and by an evaluation device (34) which is configured to determine a distance to the object (12) from the superposition detected by the detector (32). [9] Method for manufacturing a device (14) for measuring distance, the method comprising the following steps: a) Providing a light source (16) designed to produce an optical signal; b) rigidly fixing a deflection optic (44) in a holder (52) which has a flange (62) with a circumferential outer surface (63); c) rigidly mounting a photonically integrated circuit (50) to a support (54), wherein the photonically integrated circuit comprises an arrangement of free-space couplers (40) each configured to emit the optical signal generated by the light source (16) into the surrounding free space; d) Aligning the holder (52) and the support (54) relative to each other such that the free-space couplers (40) are arranged in a focal plane (43) of the deflection optics (44); characterized by the following further step: e) Welding the flange (62) of the bracket (52) to the support (54) at several weld points (80) which are radially offset inwards from the outer surface (63) of the flange (62). [10] Method according to claim 9, characterized by, that the flange (62) has openings (66) and that projections (70) are formed on the support (52) in the area of ​​the openings (66) which project into the openings (66), so that gaps (74) remain between the inner surfaces (68) of the openings (66) and outer surfaces (72) of the projections (70), the width of which decreases along the axial direction towards the support (52), and that an additional material (76) is filled into the gap. [11] Method according to claim 10, characterized by , that the additive material (76) is spherical.

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