Cover device for radar sensor, radar sensor device, motor vehicle, and method for producing cover device

Abstract

The invention relates to a covering device (10) for a radar sensor (106), comprising a decorative layer (20), which comprises a first section (22) having a first refractive index and a second section (24) having a second refractive index, and a carrier layer (30) on the decorative layer (20), the carrier layer (30) comprises a third section (32) having a third refractive index corresponding to the first section (22) and a fourth section (34) having a fourth refractive index corresponding to the second section (24), the first section (22) and the second section (24) being arranged next to one another when viewed perpendicular to the main surface (F) of the decorative layer (20), the first refractive index being greater than the second refractive index, and the second refractive index being greater than the first refractive index. The third refractive index and the fourth refractive index are equal in magnitude, and wherein the average thickness of the third section (32) is less than the average thickness of the fourth section (34). The invention further relates to a radar sensor device, to a motor vehicle, and to a method for producing a cover device.

Description

Technical Field

[0001] The invention relates to a cover device for a radar sensor, a radar sensor device having a cover device and a radar sensor, a motor vehicle having a cover device or a radar sensor device, and a method for producing a cover device. Background Art

[0002] Modern motor vehicles, in particular high-end or luxury cars, usually include various environmental sensors for detecting the vehicle environment. The data obtained by means of these environmental sensors can be used by driver assistance systems, such as light assistance systems or cruise control systems, to assist the vehicle driver in driving the vehicle. A known example of an environmental sensor is a (motor vehicle) radar sensor. The radar sensor is usually arranged at the front of the vehicle, for example in the area of ​​the bumper guard, and is arranged to emit radar waves in the forward direction and detect the radar waves reflected back from objects.

[0003] In order to prevent the radar sensor from being damaged by moisture ingress, it is known from the prior art to cover the radar sensor. For example, document DE 10 2018 205 739 A1 describes a radar bezel with a colored three-dimensional relief, in which a three-dimensional structure up to one tenth of the radar wavelength is displayed on the front of the bezel based on design elements in the pigment of the bezel material. The chrome appearance is produced based on aluminum or tin. Summary of the invention

[0004] Against this background, the object of the present invention is to provide a cover device for a radar sensor, which can be produced relatively efficiently and still achieves a relatively (phase) homogeneous transmission of radar waves. In addition, the object of the present invention is to provide a corresponding radar sensor device, a corresponding motor vehicle and a corresponding method for producing the cover device.

[0005] This object is achieved by a covering device having the features of claim 1 , a radar sensor device according to claim 9 , a motor vehicle according to claim 11 and a method for producing a covering device according to claim 12 .

[0006] The cover device is provided for a radar sensor, in particular a motor vehicle radar sensor, and comprises a decorative layer and a carrier layer on the decorative layer, wherein the decorative layer comprises a first section having a first refractive index and a second section having a second refractive index. The carrier layer comprises a third section having a third refractive index corresponding to the first section and a fourth section having a fourth refractive index corresponding to the second section. The first section and the second section are arranged side by side when observed perpendicularly to the main surface of the decorative layer. The first refractive index is greater than the second refractive index. The third refractive index and the fourth refractive index are equal in magnitude. The average thickness of the third section is less than the average thickness of the fourth section. The arithmetic mean of the respective thicknesses can be referred to as the average thickness (i.e., the averaged thickness).

[0007] This makes it possible to reduce the phase difference generated by the first section relative to the second section in a simple and effective manner. For radar waves, this phase difference can currently be caused by different phase velocities (the speed of light in a vacuum divided by the corresponding (frequency-dependent) refractive index) in the first and second sections. For example, when the radar wave propagates through the first and second sections in the direction of the environment, the phase of the second part of the radar wave propagated through the second component is offset from the phase of the first part of the radar wave propagated through the first component according to the following equation: Phi=c0*D*[1 / n2-1 / n1]. Here, Phi denotes the phase offset between the first and second parts, c0 denotes the speed of light in a vacuum, D denotes the thickness of the first and second sections (which is the same in this example) and n1 or n2 denotes the first or second refractive index.

[0008] The phase shift of the first part of the radar wave relative to the second part can be at least partially compensated by the smaller average thickness of the third section. As a result, the covered radar sensor can provide a high angular resolution. As a result, the radar sensor device with the covering device can be characterized by high precision. In addition, due to the smaller thickness of the third section, material can be saved. At the same time, optically distinguishable materials with different refractive indices can be used in the decorative layer to achieve a more flexible design of the decorative layer.

[0009] In the context of the present disclosure, a refractive index is understood to be a refractive index for radar radiation, in particular for electromagnetic radiation with a frequency between 20 and 200 GHz, preferably between 60 and 100 GHz (the so-called M-band). The (vacuum) wavelength of the radar waves is therefore preferably between about 3 mm and 5 mm. Since the third and fourth refractive indices are of equal magnitude, what is said about the third refractive index applies accordingly to the fourth refractive index.

[0010] In the present disclosure, the term "corresponding" according to its general definition may mean that the first and third segments or the second and fourth segments are related to each other. This relationship may be designed so that the first segment and the third segment overlap when viewed perpendicularly to the main surface. Similarly, the second segment may overlap with the fourth segment when viewed perpendicularly to the main surface. Therefore, a wavefront propagating through the third segment may also propagate through the first segment and / or a wavefront propagating through the fourth segment may also propagate through the second segment. Overlap may respectively mean completely consistent.

[0011] The covering device may have a front side and a rear side. Accordingly, the terms "front side" and "rear side" may also be used in the context of the present disclosure. The rear side may be the side that faces the radar sensor in a conforming arrangement. That is, radar waves emitted by the radar sensor may impinge on the rear side of the covering device, propagate through the covering device in the direction of the front side of the covering device and, after being reflected back at the object to be detected, propagate through the covering device in the opposite direction, i.e. from the front side in the direction of the rear side. The covering device may therefore preferably be referred to as radar transparent.

[0012] As already mentioned, the carrier layer is arranged on the decorative layer. In particular, the carrier layer can be formed (directly or indirectly) on the rear side of the decorative layer. Preferably, the carrier layer is materially bonded to the decorative layer, so that the third section is in planar contact with the first section. Similarly, the fourth section can be in planar contact with the second section, in particular the first section and the fourth section do not overlap when viewed perpendicularly to the main surface of the decorative layer. Preferably, the first section and the second section each extend over the entire thickness of the decorative layer.

[0013] The third section can have a first relief (so-called surface relief) defining a first intermediate surface on its side opposite to the decorative layer (i.e., the rear side). Similarly, the fourth section can have a second relief defining a second intermediate surface on its side opposite to the decorative layer. The first relief can be formed in the rear surface of the carrier layer and define the first intermediate surface in such a way that the first intermediate surface extends parallel to the main surface of the decorative layer. Similarly, the second relief can be formed in the rear surface of the carrier layer and define the second intermediate surface in such a way that the second intermediate surface also extends parallel to the main surface of the decorative layer.

[0014] If a second relief is present, it can have a different profile cross section than the first relief, so that the third and fourth sections have different average thicknesses. Preferably, the average thickness of the third section is determined by means of the first intermediate surface. The average thickness of the fourth section can be determined by means of the second intermediate surface. In particular, the distance between the end surface of the carrier layer facing the decorative layer and the first intermediate surface can correspond to the average thickness of the third section and / or the distance between the end surface of the carrier layer facing the decorative layer and the first intermediate surface can correspond to the average thickness of the fourth section. In this way, the effective phase velocity in the first and third or second and fourth sections can be determined relatively easily to achieve a high transmission phase homogeneity.

[0015] For example, the first relief can be constructed with prisms or cones arranged side by side and / or the second relief can be constructed with hemispheres arranged side by side. The bottom of the prism, cone or hemisphere is arranged toward the decorative layer. Alternatively, the first and / or second relief can form a scattering glass. In this example, the first spatial volume occupied by the material of the third section between the envelope surface of the decorative layer and the first relief facing away from the decorative layer is smaller than the second spatial volume occupied by the material of the fourth section between the envelope surface of the decorative layer and the second relief facing away from the decorative layer. Correspondingly, the second intermediate surface (assigned to the second relief) can be further away from the front side end face of the carrier layer. Therefore, the above-mentioned conditions between the average thickness of the third section and the average thickness of the fourth section are met. This also applies to the variant scheme that the first section or the second section is not constructed with the first or second relief. In this case, the average thickness of the corresponding section corresponds to its total thickness.

[0016] The third segment can preferably be configured such that the arithmetic refractive index average value of the first and third segments weighted by the thickness of the first segment and the average thickness of the third segment corresponds substantially (preferably with a deviation of up to 10%) to the arithmetic refractive index average value of the second and fourth segments weighted by the thickness of the second segment and the average thickness of the fourth segment. Alternatively, in order to improve the phase homogeneity, the following relationship (relationship between the thickness and the refractive index of the above segments) can be adopted:

[0017] D*(1 / n2-1 / n2)= D2 / n3-D1 / n3

[0018] Here, D denotes the thickness of the decorative layer, n1 to n3 denote the refractive indices of the first to third sections, D1 denotes the average thickness of the third section, and D2 denotes the average thickness of the fourth section. Thus, in this way, the phase jump caused by the different phase velocities in the first and second sections can be reduced (ie, at least partially compensated) by the smaller average thickness of the third section.

[0019] The total thickness of the covering device (measured by the first and third sections or the second and fourth sections) is preferably up to 10 mm, most preferably up to 5 mm. Preferably, the first and second sections have (substantially) the same thickness. This can be achieved in particular by means of a decorative layer constructed as an imprint on the film, in particular a screen print. The carrier layer is preferably thicker and more stable than the decorative layer, in particular harder and can give the covering device stability. The thickness of the carrier layer is preferably between 1.5 mm and 8 mm. The average thickness of the third section can be up to 6 mm here. The first relief height of the first relief and / or the second relief height of the second relief can be respectively less than the wavelength of the radar wave and preferably up to 200 μm, in particular between 50 μm and 150 μm. The distance between the lowest point of the relief and the corresponding envelope surface is referred to as the relief height. In order to more easily determine the phase compensation by means of the first relief and the second relief, the first relief height and the second relief height can be substantially the same.

[0020] A covering device with these features can be manufactured relatively simply by injection molding. In particular, the carrier layer can be simply cast onto the film, in particular the decorative layer (i.e., the decorative layer is back-molded with the material of the carrier layer). Therefore, the carrier layer is preferably constructed in an integral manner (seamlessly / "by a casting"). Accordingly, the third and fourth sections are preferably made of the same material. The carrier layer, the film and / or the cover layer described in more detail below are preferably made of a polymer, in particular polycarbonate (PC) or polymethyl methacrylate (PMMA), respectively. Alternatively, the cover layer can be made of polyurethane. In this case, the cover layer can be constructed thinner. The carrier layer, the film and / or the cover layer can be light-transmissive, in particular transparent, preferably optically transparent, respectively. In particular, in the radar spectrum, the first refractive index and / or the second refractive index can be greater than the third refractive index, respectively. The third refractive index can be between 1.6 and 1.7, preferably between 1.65 and 1.7.

[0021] The cover device can also include a heating layer and / or a covering layer. The heating layer can be made of the same substrate as the carrier layer. Advantageously, the substrate can be molded together with the carrier layer (preferably by injection molding) onto the film with the decorative layer. The heating layer substrate, film, decorative layer and carrier layer as a whole can therefore be manufactured quickly and inexpensively in a single injection molding process, in which the film with the decorative layer can be used as an insert. The heating layer preferably includes a device for electrically heating the cover device. As such a device, a heating wire is preferably considered, which is embedded in the substrate at least in sections. The thickness of the heating wire is preferably less than 2 mm. In this way, high transmission phase uniformity can be achieved while achieving efficient heating and high sealing of the cover device.

[0022] The cover layer is preferably arranged on the side of the decorative layer opposite the carrier layer and / or, if applicable, on the side of the heating layer opposite the carrier layer. If present, the cover layer forms the end face of the cover device. In the installed position of the cover device in the radar sensor device or on the motor vehicle, the end face is the outer surface of the cover device / radar sensor device, via which the radar waves generated by the radar sensor can be emitted into the environment.

[0023] The optical conditions of the covering device are further described below. The optically visible pattern of the covering device can be limited to the decorative layer. In particular, the first section (of the decorative layer) can be optically (contrastively) different from the second section. For example, the first section of the decorative layer can form a pattern that is optically distinguishable from the second section. This difference can be, for example, in color, based on transparency (such as transparent, translucent or opaque) or designed to be reflective. In addition, the first section and / or the second section can each include a plurality of sub-sections, which form a (predetermined, static) pattern respectively. In this case, the third section for local phase compensation can also include a plurality of sub-sections, which overlap with the sub-sections of the first section when observed perpendicular to the main surface of the decorative layer, and in particular are completely consistent with the sub-sections of the first section. This applies similarly to the relationship between the fourth section and the second section.

[0024] In a preferred variant, the decorative layer is backlit by means of the carrier layer. For this purpose, the carrier layer can be constructed as a light-conducting layer and in particular form a so-called planar light conductor. The carrier layer can be provided for conducting (preferably under total reflection) light coupled in at a coupling point spaced apart from the third and / or fourth section inside the light-conducting layer (and in the material). The light can be generated by means of an electrically operated light source having at least one light-emitting device (e.g. a light-emitting diode or a laser diode) with a cover device. In order to couple out the light of the carrier layer / light-conducting layer, the carrier layer can have a light coupling-out device in the third and / or fourth section. The light coupling-out device can be designed in particular to couple out the light propagating in the carrier layer at least partially in the direction of the decorative layer / the front side of the cover device. The coupling-out device can in principle be constructed as a scattered light, a reflected light or a refracted light in order to couple out the light. In a preferred variant, the light coupling-out device comprises a first relief and / or a second relief. Thus, the first / second relief can provide a mixing function in a synergistic manner, namely phase balancing of radar waves and light coupling-out.

[0025] The radar sensor device proposed in this article is arranged for a motor vehicle, in particular a land, ground or water vehicle, preferably a car or a commercial vehicle. The motor vehicle can be an at least partially electrically driven (electric hybrid or fully electric) vehicle. The radar sensor device comprises a cover device as described in detail above, a housing that defines an interior area of ​​the radar sensor device, and a radar sensor covered by the cover device. The radar sensor can also be the above-mentioned radar sensor. The cover device defines the interior area and the radar sensor is arranged at least in sections in the interior area.

[0026] If the carrier layer is designed to be light-conducting, the outer surface can form the light exit surface. The radar sensor is arranged on the rear side of the cover device in accordance with regulations. In particular, the radar sensor can emit radar waves in such a way that the radar waves at least partially pass through the first and second sections and propagate parallel thereto through the third and fourth sections. In other words, the first, second, third and / or fourth section can be arranged in the detection area of ​​the radar sensor.

[0027] In a variant, the radar sensor can extend from the housing on the side opposite to the cover device. The radar sensor can include its own sensor housing. In this way, the radar sensor device can provide high structural space efficiency. Advantageously, the radar sensor can be better cooled here. In addition, the radar sensor device can have a funnel-shaped shield. In a variant, the shield can taper from the housing toward the radar sensor. Accordingly, the shield preferably forms a funnel that absorbs radar waves. The surface of the shield facing the cover device can preferably be constructed as an injection-molded absorber, which is especially made of expanded polypropylene (EPP). In another variant, the radar sensor can be integrated in the cover device, especially injection-molded with the material of the cover device.

[0028] The motor vehicle proposed here comprises the above-described covering device or the above-described radar sensor device. Preferably, the covering device forms a front end surface of the motor vehicle, onto which the driving air flows during driving.

[0029] In the method proposed here, the above-mentioned covering device is produced by means of at least one injection molding process, wherein the injection molding process has the following steps, which are preferably carried out in the order described below: inserting the insert with the decorative layer into the injection mold; injecting the molding compound for the carrier layer into the cavity of the injection mold, wherein the carrier layer is molded onto the insert. The insert can in particular include a decorative layer on a film.

[0030] The carrier layer can preferably be cast directly onto the decorative layer. Most preferably, the step of injecting the molding compound includes forming the carrier layer and forming a layer with a heating layer substrate on the side of the decorative layer opposite the carrier layer. Thus, after the carrier layer has been molded onto the insert, the heating wire is at least partially embedded into the substrate by means of an ultrasonic generator to form the finished heating layer. Relatively expensive heating films can be omitted.

[0031] In the next step, the cover layer can then be formed directly on the front side on the heating layer or (in the absence of a heating layer) directly on the decorative layer. This step can be carried out by reaction injection molding and preferably comprises the following steps, which can be carried out in particular in the order mentioned below: removing the first mold cover of the injection mold after the injection-compression process; placing the second mold cover of the injection mold; filling the cavity of the injection-compression mold with a second molding compound to form the cover layer, wherein the second molding compound contains two (or more) components. In order to form the cover layer from polyurethane, the second molding compound can contain the corresponding polyol and polyisocyanate.

[0032] Both the radar sensor device and the motor vehicle and the method may include any desired features, in particular all of the features described above in conjunction with the cover device. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Preferred variants of a cover device, a radar sensor device, a motor vehicle and a method for producing a cover device are now explained in more detail with reference to the schematic drawings.

[0034] Figure 1 A variant of the covering device is shown in cross section;

[0035] Figure 2 Detailed cross-sectional view showing Figure 1 A variation of , in which the first, second, third and fourth sections are shown enlarged;

[0036] Figure 3 A further variant of the covering device is shown in cross section, wherein a second relief is formed on the fourth section;

[0037] Figure 4 Detailed cross-sectional view showing Figure 3 A variation of , in which the first, second, third and fourth sections are shown enlarged;

[0038] Figure 5 A further variant of the cover device is shown in cross section, in which the first section is designed in multiple parts;

[0039] Figure 6 A variant of a radar sensor device is shown;

[0040] Figure 7 Another variant of a radar sensor device is shown;

[0041] Figure 8 A motor vehicle having a radar sensor device is shown;

[0042] Figure 9a -c shows the manufacturing Figure 1 an intermediate state of the covering device in; and

[0043] Fig.10 Shown for manufacturing Figure 1 A method for covering a device in. DETAILED DESCRIPTION

[0044] Figure 1 and 2 Shown for Figure 6 1. The radar sensor 106 is designed as a motor vehicle radar sensor and is used for Figure 8 The cover device 10 is used in a motor vehicle 200 shown in a simplified manner in FIG. Figure 1 The rear side shown below and Figure 1 The front side is shown above. In a proper installation, the rear side is arranged toward radar sensor 106 (see Figure 6 ).

[0045] The cover device 10 comprises a decorative layer 20 and a carrier layer 30 which is formed on the rear side of the decorative layer 20. Figure 1 In a variant of the invention, the carrier layer 30 is molded directly onto the rear side of the decorative layer 20. The decorative layer 20 is provided as a screen print on the film 21 and comprises a first section 22, which is optically distinguishable from a second section 24. In the present case, the first section 22 is, for example, darker than the second section 24. The first section 22 can be light-transmissive; at least the second section 24 is light-transmissive. The first section 22 has a first refractive index for a predetermined (radar) frequency of electromagnetic radiation and the second section 24 has a second refractive index for a predetermined frequency of electromagnetic radiation. The predetermined frequency is the operating frequency of the radar sensor 106. In the present case, this frequency is, for example, between 70 and 80 GHz.

[0046] When viewed perpendicularly to the main surface F of the decorative layer 20, the third section 32 of the carrier layer 30 completely overlaps the first section 22, preferably, in particular, substantially overlaps. Similarly, the fourth section 34 of the carrier layer 30 completely overlaps the second section 24, preferably, in particular, substantially overlaps. Thus, the third section 32 corresponds to the first section 22 and the fourth section 34 corresponds to the second section 24. Figure 1As shown in FIG. 1 , the first section 22 and the second section 24 are arranged side by side and substantially do not overlap when viewed perpendicularly to the main surface F. This applies analogously to the third section 32 and the fourth section 34 .

[0047] The third section 32 has a third refractive index for a predetermined frequency and the fourth section 34 has a fourth section for a predetermined frequency. The contents described below for the first to fourth refractive indices apply to the predetermined frequency. The third refractive index and the fourth refractive index are equal, while the first refractive index is greater than the second refractive index. That is, the covering device 10 allows the use of pigments with different refractive indices for radar waves. This is achieved by making the average thickness D1 of the third section 32 smaller than the average thickness D2 of the fourth section 34. Accordingly, the phase mutation caused by the decorative layer 20 is compensated by the different average thicknesses D1 and D2 to improve the phase uniformity. In the present case, the carrier layer 30, in particular the third section 32 and the fourth section 34, are made of polycarbonate, in particular transparent, which is cast onto the decorative layer 20. The third and fourth refractive indices are therefore 1.67 respectively. The film 21 is also made of polycarbonate and is light-transmissive, in particular transparent, in this case. The arithmetic mean refractive index along the axis passing through the first and third sections 22 , 32 weighted based on the respective thicknesses may correspond to the arithmetic mean refractive index along the axis passing through the second and fourth sections 24 , 34 also weighted based on the respective thicknesses.

[0048] exist Figure 1 In a variant of , the fourth section 34 has a substantially constant thickness over its width, which thickness thus corresponds to the average thickness D2. In contrast, the third section 32 has a first relief 33 on its side opposite the decorative layer 20, which first relief defines an average first intermediate surface M1. The average thickness D1 of the third section 32 is thus Figure 2 The distance between the interface of the first section 22 and the third section 32 and the first intermediate surface M1 is shown. The height H1 of the first relief 33 is preferably between 50 μm and 200 μm, for example 100 μm. The first relief 33 consists of a plurality of prisms, which form light coupling-out devices and can thus deflect light propagating in the carrier layer 30 configured as a transparent light-conducting layer in the direction of the decorative layer 20. In this case, the light is coupled out from the carrier layer 30. In order to generate light and couple it into the carrier layer 30, the cover device 10 includes a light source 34.

[0049] according to Figure 1 and 2The embodiment of the cover device 10 can compensate for phase differences of more than 3° caused by the first and second sections 22, 24. This phase compensation is explained below by an example calculation of a spatial volume occupied by a first relief 33 with a height H1 (up to the envelope surface) and a corresponding spatial volume of the same height completely occupied by the material of the fourth section 34. In the case of a first height H1 of 100 μm, a refractive index of polycarbonate of 1.67 and a vacuum wavelength of 3.9 mm, a phase jump of 15.4° is calculated for the spatial volume with the height H1 in the region of the fourth section. The phase jump in the spatial volume with the height of the first relief 33 in the region of the third section is 12.3° (since only half of the spatial volume is filled with polycarbonate, an average refractive index of (1.67+1) / 2=1.33 is assumed). The radar wave portion propagating through the third section is therefore phase-shifted by approximately 3° relative to the radar wave portion propagating parallel thereto through the fourth section. The (effective) refractive index of the spatial region can be calculated based on the volume ratio of the two materials (in this case polycarbonate and air).

[0050] The cover device 10 has a heating layer 40 and a cover layer 50 on the front side relative to the carrier layer 30, in which a heating wire 42 is embedded at least in sections, and the cover layer forms an end face 52 of the cover device 10. The light from the carrier layer 30 is emitted from the cover device 10 through the end face 52 on the front side, so the end face 52 can be called a light emission face. The material of the heating layer 40 can be integrally formed with the carrier layer 30, especially integrally formed (integrally). Therefore, the substrate is preferably the same material as the material of the carrier layer 30, that is, polycarbonate in this example. The cover device 10 with these features can be manufactured relatively inexpensively by injection-molding the decorative layer 20 and subsequently embedding the heating wire 42 in the substrate in the heating layer 40 (if necessary before manufacturing the cover layer 50). Although the cover layer 50 can also be made of the same material as the carrier layer 30 in principle, the cover layer 52 is preferably made of polyurethane, which is molded onto the finished heating layer 40 during the reaction injection molding process.

[0051] Figure 3 and 4 Another covering device 10 shown in Figure 1The difference between the cover device 10 in FIG. 1 and FIG. 2 is that the fourth section 34 has a second relief 35 on its side opposite to the decorative layer 20, which defines the second intermediate surface M2. The average thickness D2 of the fourth section 34 is determined by means of the second intermediate surface M2, that is, the distance between the end surface of the carrier layer 30 facing the decorative layer 20 and the second intermediate surface M2 corresponds to the average thickness D2. The second relief 35 has a cross-sectional profile different from the first relief 33. In the present case, the cross-sectional profile of the first relief 33 is configured as a (sawtooth) profile with V-shaped sawteeth arranged side by side, and the cross-sectional profile of the second relief 35 is configured as a profile with U-shaped sections arranged side by side. This difference affects the third and fourth sections 32, 34 in such a way that the interface distance between the second intermediate surface M2 and the second and fourth sections 24, 34 is farther than the interface distance between the first intermediate surface M1 and the first and third sections 22, 32.

[0052] The second relief 34 can compensate for the phase jump caused by the second section 24. Accordingly, the second refractive index of the second section 24 is lower than the first refractive index 22 and higher than the refractive index / or refractive index of the rest of the decorative layer 20. In this variant, the light outcoupling device of the carrier layer 30 comprises a first relief 33 and a second relief 35. In addition, Figure 3 and 4 The covering device 10 comprises Figure 1 and 2 All features of the covering device 10.

[0053] Figure 5 Another covering device 10 shown in Figure 3 The difference between the cover device 10 in FIG. 2 and FIG. 3 is that the first section 22 includes a plurality of regions (so-called sub-segments). These regions can together form a pattern that is optically different from the second section. Therefore, the first relief 33 also includes a plurality of regions corresponding to the regions of the first section 22. Figure 5 In a variant of the present invention, at least two such regions of the first section 22 or the first relief 33 are separated from one another by the second section 24 or the fourth section 34. In addition, Figure 5 The covering device 10 comprises Figure 3 and 4 All features of the covering device 10 in.

[0054] Figure 6 and 7 Different radar sensor devices 100 are shown for a motor vehicle 200. Each radar sensor device 100 has Figure 1, a cover device 10 (alternatively one of the other cover devices 10 described above), a housing 102 and a radar sensor 106 to be covered. Housing 102 defines an interior area 104 of radar sensor device 100, wherein the interior area is defined in both variants by means of cover device 10. Figure 6 In a variant of , radar sensor 106 is completely arranged in inner region 104 (ie, is actually encapsulated in the housing). Figure 7 In a variant of , radar sensor 106, in particular a radar sensor housing of radar sensor 106, projects from housing 102 of radar sensor device 100 at the rear. Radar sensor 106 can thus be cooled better. Between radar sensor 106 and the side of housing 102 on which cover device 10 is formed, radar sensor device 100 can also have a funnel-shaped, radar-absorbing shield 110 which tapers from housing 102 in the direction of radar sensor 106.

[0055] Figure 8 The motor vehicle 200 shown in FIG. 1 includes Figure 1 , 3 or the covering device 10 in 5, preferably as Figure 6 7, wherein the cover device 10 can be designed as a section of a headlight 202 of a motor vehicle 200. Accordingly, the cover device 10 is designed to radiate the light coupled into the carrier layer 30 by means of the light source 34 at least partially in the longitudinal direction of the vehicle.

[0056] Fig.10 The method 300 schematically shown in FIG. 1 is used to manufacture Figure 1 The method 300 can be similarly implemented to manufacture Figure 3 or Figure 5 The method 300 comprises at least one injection molding process, wherein in a first step 302 an insert with a decorative layer 20 is placed in an injection mold. Subsequently, in a step 304 a molding compound for a carrier layer 30 is injected into the cavity of the injection mold, wherein the carrier layer 30 is molded onto the insert. Figure 9a An intermediate product of the covering device 10 is shown in FIG. 5 , which is without the heating wire 42 and the cover layer 50 .

[0057] In another step 306, the heating wire 42 can be embedded into the heating layer 40 substrate formed in step 304 by means of an ultrasonic generator to complete the heating layer 40 (see Figure 9b ). Then, in another step 308, the cover layer 50 can be formed by reaction injection molding onto the heating layer 40. Figure 9bThe intermediate product is shown in FIG. 1. An injection mold provided for injection molding can be filled with the reactants for forming the polyurethane.

[0058] The terms "comprising", "having", "having" etc. used in the present disclosure are to be understood as non-exhaustive. In particular, the term "comprising one" in this context means "comprising at least one", i.e. "comprising one" does not exclude the presence of other corresponding elements. For example, the terms "comprising a carrier layer", "comprising a light source" and "having a first section" are to be understood as meaning that the covering device can have one or more carrier layers and one or more light sources and the decorative layer can have one or more first sections. The above mathematical relationships and equations are considered to be satisfied if the deviation therefrom does not exceed the manufacturing tolerance. The term "substantially" is to be understood as being within the usual manufacturing tolerance range (+ / - 10% of the corresponding value).

Claims

1. A cover device (10) for a radar sensor (106), the cover device comprising a decorative layer (20) and a carrier layer (30) on the decorative layer (20), the decorative layer comprising a first section (22) having a first refractive index and a second section (24) having a second refractive index, wherein: The carrier layer (30) comprises a third segment (32) having a third refractive index corresponding to the first segment (22) and a fourth segment (34) having a fourth refractive index corresponding to the second segment (24), wherein the first segment (22) and the second segment (24) are arranged side by side when viewed perpendicularly to a main surface (F) of the decorative layer (20), wherein the first refractive index is greater than the second refractive index, wherein the third refractive index and the fourth refractive index are equal in magnitude, and wherein an average thickness (D1) of the third segment (32) is smaller than an average thickness (D2) of the fourth segment (34).

2. The covering device (10) according to claim 1, wherein: The third section (32) has a first relief (33) on its side opposite to the decorative layer (20) for defining a first intermediate surface (M1), and the average thickness (D1) of the third section (32) is determined with the aid of the first intermediate surface (M1); and / or the fourth section (34) has a second relief (35) on its side opposite to the decorative layer (20) for defining a second intermediate surface (M2), and the average thickness (D2) of the fourth section (34) is determined with the aid of the second intermediate surface (M2).

3. The covering device (10) according to any one of the preceding claims, wherein: The first refractive index and / or the second refractive index are respectively greater than the third refractive index, and / or the third refractive index is between 1.6 and 1.

7.

4. The covering device (10) according to any one of the preceding claims, wherein: The decorative layer (20) is designed as a screen print on a film (21), and / or the carrier layer (30) is cast onto the decorative layer (20), and / or the third and fourth sections (32, 34) are made of the same material.

5. The covering device (10) according to any one of the preceding claims, further comprising one or more of the following layers: a heating layer (40), in which the heating wire (42) is at least partially embedded; and / or a covering layer (50) on the side of the decorative layer (20) opposite to the carrier layer (30), wherein: The cover layer (50) forms an end surface (52) of the cover device (10).

6. The covering device (10) according to any one of the preceding claims, wherein: The first section (22) is optically different from the second section (24), and / or wherein: The decorative layer (20) is at least partially light-transmissive, and / or the carrier layer (30) is at least partially light-transmissive.

7. The covering device (10) according to any one of the preceding claims, wherein: The carrier layer (30) is configured as a light-conducting layer, and / or wherein: The carrier layer (30) has a light coupling device in the third and / or fourth section (32, 34), which is designed to couple light propagating in the carrier layer (30) at least partially in the direction of the decorative layer (20).

8. The covering device (10) according to claim 7 in combination with claim 2, wherein: The light outcoupling device comprises a first and / or a second relief (33, 35).

9. A radar sensor device (100) for a motor vehicle, comprising a covering device (10) according to any one of the preceding claims, a housing (102) defining an interior area (104) of the radar sensor device (100), and a radar sensor (106) covered by means of the covering device (10), wherein: The covering device (10) defines an interior area, wherein the radar sensor (106) is arranged at least in sections in the interior area (104).

10. The radar sensor device (100) according to claim 9, wherein: The radar sensor (106) protrudes from the housing (102) on a side (108) opposite the cover device (10), and / or the radar sensor device (100) further comprises a funnel-shaped shield (110) which tapers from the housing (102) in the direction of the radar sensor (106).

11. A motor vehicle (200) comprising a covering device (10) according to any one of claims 1 to 8 or a radar sensor device (100) according to claim 9 or 10.

12. A method (300) for producing a covering device (10) according to any one of claims 1 to 8, the method comprising at least one injection molding process, the injection molding process comprising the following steps: placing (302) an insert having a decorative layer (20) into an injection mold; A molding compound for the carrier layer (30) is injected (304) into the cavity of the injection mold, wherein: A carrier layer (30) is molded onto the insert.

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