Heated scattered light diaphragm of an image capturing device for a motor vehicle, and method for producing the scattered light diaphragm

Abstract

The invention relates to a heated scattered light diaphragm (5) of an image capturing device (1). The scattered light diaphragm (5) is part of a housing part (4, 5) which surrounds a spatial region (6) and is provided for arrangement on the inner side of a pane (2) which covers the spatial region (6). The scattered light diaphragm (5) has a plastic layer (9) which provides dimensional stability, an electrical heating element (7) and a light-absorbing coating (8). The plastic layer (9) is injection-moulded only on the underside of the heating element (7) and the coating (8) is applied directly to the upper side of the heating element (7) without a dimensionally stable intermediate layer. The invention further relates to an image capturing device and a windscreen, each having a scattered light diaphragm according to the invention, and to a method for producing the scattered light diaphragm.

Description

[0001] 19.03.2026 RSWGmbH

[0002] Ludwig-Behr-Straße 4

[0003] 82327 Tutzing

[0004] Germany

[0005] Heated stray lens hood of an image acquisition device for a motor vehicle and method for manufacturing the stray lens hood

[0006] The invention relates to a lens hood for an image capture device for a motor vehicle for shielding a detection area of ​​a camera of the image capture device, wherein the lens hood is part of a housing component that surrounds a spatial area and is intended for arrangement on the inside of a window of the motor vehicle, such that the window covers the spatial area and the detection area extends through the spatial area towards the window, and wherein the lens hood comprises a dimensionally stable plastic layer, an electric heating element, and a light-absorbing coating. The invention further relates to an image capture device with such a lens hood, a windshield of a motor vehicle with such a lens hood, and a method for manufacturing the lens hood.

[0007] Image capture devices of this type are known. The housing, or rather the lens hood, prevents unwanted light, whether from the passenger compartment of the vehicle or from the outside, from falling onto the camera. It is common practice to make the surfaces of the lens hood facing the interior of the housing or the windshield rough or ribbed, or to coat them with a special lacquer, in order to prevent light entering the interior through the windshield from being reflected or scattered by the lens hood and thus entering the camera's field of view and being captured.The electric heating element of the stray light diaphragm serves to heat the area of ​​the room, and thus indirectly also that area of ​​the disc which covers the room and forms a viewing window of the image capture device, and thereby to remove or keep free of snow or ice on the outside and of condensed water vapor from humid air on the inside.

[0008] German patent application DE 102014006891 A1 discloses an arrangement for heating a viewing window of an image acquisition unit for a motor vehicle, comprising at least one heating element, a lens hood, the viewing window, and the image acquisition unit. It proposes integrating the heating element into the lens hood to avoid an adhesive bond between the heating element and the lens hood, since the adhesive strength of the bond weakens, especially at higher temperatures. Integrating the heating element into the lens hood thus improves the durability of the arrangement. The integration is achieved, for example, by manufacturing the lens hood using injection molding and forming the heating element as an insert that is then overmolded. This method is intended to integrate the at least one heating element into the lens hood cost-effectively and reliably.Furthermore, integrating the heating element into the lens hood, instead of gluing the heating element onto the lens hood, saves a manufacturing step.

[0009] As a further solution, DE 102014006891 A1 proposes that the lens hood be formed as a pressed body from a powder and that the heating element be pressed into the lens hood. For this purpose, the heating element is placed in the mold with the powder before pressing, so that it is pressed in during the pressing of the lens hood. This allows the use of materials for the lens hood that are not suitable for injection molding. According to a third possibility, the lens hood can have a pocket into which the heating element is inserted.As a fourth solution, DE 102014006891 A1 mentions that the lens hood is designed in two or more parts and that the at least one heating element is inserted between the parts of the lens hood, wherein the parts of the lens hood are joined together by clipping, gluing, welding, crimping or hot stamping, so that the at least one heating element is enclosed in the lens hood. A common feature of all variants is that the heating element is integrated into the lens hood, i.e., located between an upper layer of the lens hood and a lower layer of the lens hood.

[0010] The object of the present invention is to improve the scattering light diaphragm of a generic image capture device in such a way that the effect of the heating element of the scattering light diaphragm is improved, in particular the room area and the viewing window are heated faster and more effectively, without using elaborate alternatives for scattering or absorbing the light incident on the image capture device.

[0011] This problem is solved by an image acquisition device with the features of claim 1. Advantageous further developments are specified in the dependent claims and are explained below.

[0012] According to the invention, a stray light shield for an image acquisition device for a motor vehicle is proposed for shielding a detection area of ​​a camera of the image acquisition device, wherein the stray light shield is part of a housing part that surrounds a spatial area and is intended to be arranged on the inside of a window of the motor vehicle, so that the window covers the spatial area and the detection area extends through the spatial area towards the window in order to detect the environment outside the spatial area through the window, and wherein the stray light shield comprises a dimensionally stable plastic layer, an electric heating element and a light-absorbing coating.and the plastic layer is only injection-molded onto the underside of the heating element facing away from the room area, and the light-absorbing coating is applied directly to the top side of the heating element facing the room area without a dimensionally stable intermediate layer.

[0013] In the method according to the invention, it is provided that first the light-absorbing coating is applied directly to the top of the heating element without a dimensionally stable intermediate layer, in particular laminated on, and then a plastic is injected onto the underside of the heating element facing away from the room area, so that the plastic layer which gives the diffusing light diaphragm its dimensional stability is formed, which completely covers the underside, leaving the top of the heating element facing the room area and bearing the light-absorbing coating uncovered, so that the coating forms the top of the diffusing light diaphragm facing the room area as intended.

[0014] The light-absorbing coating is applied to the heating element before the plastic is injected, resulting in a structural unit consisting of the heating element and the coating. This unit is then inserted into an injection molding machine, and the plastic is injected onto the underside of the unit facing away from the coating, in such a way that the plastic only covers the underside of the heating element facing away from the room. The diffuser according to the invention therefore lacks a stable plate between the heating element and the room. In other words, the heating element, on its upper side facing the room / interior of the housing, is not covered by the plastic material forming the housing, but only by the light-absorbing coating.This results in the heating element being positioned closer to the lens, and due to the absence of a rigid intermediate layer that would provide thermal insulation, the infrared radiation emitted by the heating element can penetrate the room more effectively, i.e., with less attenuation, and thus heat it. This increases the efficiency of the diffuser heating system formed by the diffuser and heating element.

[0015] The heating element can, for example, be a heating film. The heating film can have a substrate in the form of a plastic film on which heating wires in the form of conductor tracks or conductive pads are applied. Another film can cover the conductor tracks or conductive pads, so that they are sandwiched between the two films. Preferably, the films are in contact in the areas where there are no conductor tracks or conductive pads. Alternatively, and preferably, the heating element can be a self-conducting film without conductor tracks. In this case, the heating element does not generate heat along linear paths defined by conductor tracks, but rather across its entire surface, so that the self-conducting film acts as a surface heater. In an advantageous embodiment, the light-absorbing coating can be formed from fine, vertically oriented fibers, a few millimeters high, which form a velvety, soft surface on the top of the heating element.The fiber layer ensures that the interior-facing surface of the lens hood has a high surface roughness in order to minimize reflections of the light entering through the lens towards the camera.

[0016] To hold the fibers to the heating element, the top of the heating element can be coated with an adhesive layer. This layer holds the fibers to the heating element, preferably only at one of their axial ends, so that they are oriented perpendicularly. It should be noted that this adhesive layer is not a dimensionally stable intermediate layer because, at least in its applied state, it lacks inherent stability. Furthermore, the adhesive layer should be considered part of the coating, as it is necessary to hold the fibers in place.

[0017] The adhesive layer can be applied to the heating element in a first step. Then, in a second step, the fibers can be sprinkled onto the adhesive layer. In a third step, the fibers can be aligned using an electromagnetic field. Therefore, it is advantageous if the fibers are made of an electrostatically chargeable material, e.g.,

[0018] Wool, degummed silk, or synthetic fibers such as polyester, acrylic, or nylon. The flocked heating element can then be placed in the injection molding machine in a fourth step, where the plastic forming the lens hood housing is injected onto the underside of the heating element facing away from the coating or flocking.

[0019] In another design variant, the light-absorbing coating can be a velour made of fibers laminated onto the surface of the heating element facing the room. The velour fibers stand away from a carrier material, which can be a textile surface, such as a woven, knitted, or nonwoven fabric, or a flocked film, particularly a plastic film. This facilitates handling of the light-absorbing coating, which can therefore be manufactured independently of the stray light visor heater. In these cases, the fibers are not applied directly to the heating element.

[0020] Rather, they are connected to the heating element by laminating the carrier material onto it. It should be noted that this carrier material also does not form a dimensionally stable intermediate layer, especially since – from a process engineering perspective – it is part of the coating.

[0021] Ideally, the fibers should be oriented vertically. In other words, the fibers should be perpendicular, or at least substantially perpendicular, to the heating element. This has the advantage that the heat, or rather infrared radiation, emitted by the heating element can be transferred to the interior space and convect almost unimpeded. The fiber length can range from 0.5 mm to 5 mm.

[0022] A further advantage is achieved when the fibers are black. This ensures that the coating absorbs the maximum amount of light entering through the viewing window.

[0023] The invention also relates to an image capture device for a motor vehicle for intended arrangement on the inside of a window of the motor vehicle, comprising a camera with a capture area and a housing part made of plastic that surrounds a spatial area and is intended for arrangement on the inside of a window of the motor vehicle, such that the window covers the spatial area and the capture area extends through the spatial area towards the window, wherein a part of the housing part is a scattering light diaphragm according to the invention described herein.

[0024] In one embodiment, the lens directly covers the area of ​​the image. In other words, the housing part is open towards the lens and is closed by the lens. The portion of the lens that covers the area of ​​the image forms a viewing window for the image capture device. In an alternative embodiment, the area of ​​the image is covered by an intermediate lens that is transparent to the camera. This intermediate lens, together with the housing part or the lens hood, forms a housing for the image capture device. The housing part can then be attached to the vehicle's windshield with the intermediate lens in such a way that the intermediate lens rests against the windshield. When attached to the windshield, the lens hood or image capture device according to the invention forms a structural and functional unit with the windshield.As already mentioned, the disc can be the windshield of the motor vehicle, so that the camera's viewing direction from inside the vehicle is forward, i.e., directed in the direction of travel. The invention therefore also relates to a windshield of a motor vehicle with a scattering light visor or image capture device according to the invention.

[0025] However, it is also possible that the disc is the rear window of the motor vehicle or a disc of the headlights or the reversing lights of the motor vehicle.

[0026] Furthermore, the invention relates to a motor vehicle with an image capture device according to the invention.

[0027] Further features, advantages, properties, and effects of the invention are explained below with reference to an exemplary embodiment and the accompanying figures. Reference numerals in the various figures denote identical or at least functionally equivalent components, parts of components, spatial regions, sections, surfaces, directions, and the like. Where a specific feature is described above or below in connection with a particular embodiment, it is hereby clarified that this feature may also be part of another described embodiment, unless expressly stated otherwise or technically excluded.

[0028] It should be noted that, within the context of this description, the terms "exhibit," "comprise," or "include" in no way exclude the presence of other characteristics. Furthermore, the use of the indefinite article for an object does not preclude its plural form.

[0029] Figure 1 shows a schematic representation of an image acquisition device of a motor vehicle with a heated strut shutter according to the invention.

[0030] Figure 2: the stray lens hood from Figure 1 along the cross-section AA in Figure 1

[0031] Figure 1 shows an image capture device 1 for a motor vehicle, which is intended for mounting on a disc 2 of the motor vehicle, for example its windshield. The motor vehicle can be a car or a truck.

[0032] The image capture device 1 comprises a camera 3 and a housing part 4, 5 made of plastic surrounding a space area 6.

[0033] The housing part 4, 5 is attached to the inside of the vehicle's windshield, for example, by gluing, so that the windshield 2 covers the area 6. More precisely, only a partial area 2a of the windshield 2 covers the area 6 and thus forms a viewing window 2a for the image capture device. In this embodiment, the viewing window 2a is therefore structurally an integral part of the vehicle. In another embodiment, the viewing window 2a can be an independent component of the image capture device 1.

[0034] The camera 3 has a lens 3a that projects into the spatial area 6. The lens 3a has a detection area 3b, which lies between the dashed lines in Figure 1 and extends through the spatial area 6 towards the window 2. The viewing direction B of the camera 3 is thus directed towards the viewing window 2a in order to capture the surroundings beyond the window 2, outside the spatial area 6, through the viewing window 2a. If the viewing window 2a is part of a windshield, the viewing direction B corresponds to the direction of travel of the vehicle, so that the camera 3 captures the area in front of the vehicle. The image-recording part of the camera 3 is located outside the housing parts 4, 5. The housing parts 4, 5 have an opening through which the lens 3a projects into the spatial area 6.

[0035] Of course, other variations are also possible. For example, the lens 3a can be positioned in front of the housing part 4, 5 without protruding into the space 6, and can only see into the space 6 through the opening. In another embodiment, the camera 3 can be positioned completely within the housing part 4, 5.

[0036] The housing part 4, 5 has side walls 4 (only the rear side wall is shown in Figure 1) that project upwards towards the lens 2 and a base 5. The side walls 4 and the base 5 together define the space 6. The lens 2 slopes towards the base 5. The housing part 4, 5 acts as a light baffle, as at least part of the side walls 4 and the base 5 prevent stray light from the vehicle interior or passenger compartment, or from outside, from entering the detection area 3b or the lens 3a. To prevent light entering through the viewing window 2a from being reflected or scattered by the light baffle 5 to the lens 3a of the camera 3, a light-absorbing coating 8 is provided on the upper surface of the base 5 facing the space 6. The base 5 of the housing part 4, 5 is heated. It includes a heating element 7 and thus forms a heated lens hood 5.This is illustrated using Figure 2.

[0037] Figure 2 shows a cross-sectional view through the base 5, or the heated light baffle 5, along the cross-section AA in Figure 1. The light baffle 5 comprises a dimensionally stable plastic layer 9, an electric heating element 7, and the light-absorbing coating 8, which together form a structural unit in the form of a heated, light-absorbing light baffle 5. In a narrower sense, the dimensionally stable plastic layer 9 already constitutes the actual light baffle; however, the heating element 7 and the light-absorbing coating 8 give the light baffle additional functions.

[0038] The heating element 7 is designed to heat the space 6 within the housing 4, 5, and thus indirectly also the viewing window 2a, thereby removing or keeping clear of snow, ice, or condensed water vapor. The light-absorbing coating 8 prevents light entering through the viewing window 2a from being reflected or scattered towards the camera 3 or its lens 3a.

[0039] As Figure 2 shows, the plastic layer 9 is only injection-molded onto the underside of the heating element 7, facing away from the room area 6, while the top side of the heating element 7, facing the room area 6, remains free of injection-molded plastic. The plastic layer 9 thus effectively supports the heating element 7. The light-absorbing coating 8 is applied directly to the top side of the heating element 7, i.e., without a dimensionally stable intermediate layer. The heating element 7 therefore effectively supports the coating 8. Consequently, the heating element 7 is located closer to the room area and, due to the absence of an intermediate layer that would create thermal resistance, can transfer heat to the room area 6 more effectively than if an intermediate layer were present between the heating element 7 and the light-absorbing coating 8.

[0040] The heated lens hood 5 is manufactured by first applying, in particular by laminating, the light-absorbing coating directly onto the top surface of the heating element 7 without a dimensionally stable intermediate layer. The unit formed from the heating element 7 and the light-absorbing coating 8 is then placed in an injection mold, and the plastic forming the housing parts 4, 5 is injected onto the underside of the heating element 7 facing away from the area 6. This creates the plastic layer 9 that gives the lens hood 5 its dimensional stability and completely covers the underside of the heating element 7. The top surface of the heating element 7 facing the area 6 is left uncovered, as it already bears the light-absorbing coating 8.

[0041] The heating element 7 is a heating film. It has an electrically conductive layer or film made of metal or plastic, with the plastic layer or film containing electrically conductive particles. The layer or film can have a thickness between 30 pm and 150 pm. Due to the electrical resistance of the film or layer, the heating film generates heat across its entire surface and not just along narrow conductive traces, so that the entire surface of the heating element 7 is actively heated.

[0042] In an alternative embodiment not shown, the heating element 7 can consist of a lower and an upper foil layer, between which electrically conductive heating wires are arranged in a sandwich-like fashion, generating heat due to their ohmic resistance. The heating wires extend parallel at least in sections. In one embodiment, the heating wires 7a can merge into one another in a serpentine or meandering fashion, forming a single, continuous heating wire with only one beginning and one end. The beginning and the end then form the two electrical terminals of the heating element. Alternatively, the heating wires 7a can all be arranged in parallel such that all beginnings are connected to a first electrical node and all ends to a second electrical node, the nodes forming the electrical terminals of the heating element 7.

[0043] The light-absorbing coating 8 prevents light from entering the lens 3a. The coating 8 is formed from fine, upright fibers, a few millimeters high, which create a velvety, soft surface on the top of the heating element 7. The coating 8 consists of the fibers and an adhesive layer 8a in which the fibers 8a are fixed. This fixation is such that the fibers adhere to the adhesive layer 8a with one axial end and thus extend away from the heating element 7. All fibers are therefore upright. The coating 8 is thus velour-like. The fibers create a structure and increase the surface area of ​​the heating element 7, which causes the scattering of the incident light and light absorption. To maximize this effect, the fibers are dark, specifically black.

[0044] To produce the coating 8, the adhesive layer 8a is applied to the top surface of the heating element 7. The fibers are then sprinkled onto the coated surface. Fiber alignment is achieved by using electrostatically chargeable fibers and placing the heating element 7 coated with the adhesive layer 8a in an electromagnetic field whose field lines penetrate the top surface of the heating element 7 at right angles. The fibers then align themselves parallel to the field lines and are thus perpendicular to the top surface. To prevent the fibers from being wetted by the adhesive layer 8a at any point other than their axial end, the fibers can be sprinkled onto the top surface of the heating element 7 while the electromagnetic field is already present. This allows the fibers to align themselves before they reach the top surface of the heating element 7 and make contact with the adhesive layer 8a.

[0045] In one embodiment (not shown), the light-absorbing coating 8 can be a velour applied to a substrate in the form of a textile surface (textile) or a film, with this substrate material together with the velour being laminated onto the heating element 7. The fibers forming the velour are fixed upright on the substrate. The textile surface can be a woven, knitted, or nonwoven fabric. In the case of a woven fabric, it is also referred to as a velour fabric, and in the case of a film, as a velour film. In this embodiment, the textile surface or the film is part of the coating 8 and is applied directly to the upper surface of the heating element 7 facing the room area 6.

[0046] It should be noted that the foregoing description is given merely as an example for illustrative purposes and in no way limits the scope of protection of the invention. Features of the invention that are indicated as "may," "exemplary," "preferred," "optional," "ideal," "advantageous," "if applicable," or "suitable" are to be considered purely optional and likewise do not limit the scope of protection, which is exclusively defined by the claims. Insofar as the foregoing description mentions elements, components, process steps, values, or information that have known, obvious, or foreseeable equivalents, these equivalents are also encompassed by the invention.Likewise, the invention includes any changes, alterations or modifications of embodiments which involve the replacement, addition, modification or omission of elements, components, process steps, values ​​or information, as long as the basic idea of ​​the invention is retained, regardless of whether the change, alteration or modification leads to an improvement or deterioration of an embodiment.

[0047] Although the foregoing description of the invention mentions a multitude of physical, intangible, or process-related features relating to one or more specific embodiments, these features can also be used in isolation from the specific embodiment, at least insofar as they do not necessarily require the presence of further features. Conversely, these features mentioned in relation to one or more specific embodiments can be combined arbitrarily with one another and with further disclosed or undisclosed features of illustrated or unillustrated embodiments, at least insofar as the features do not mutually exclude each other or lead to technical incompatibilities.

Claims

March 19, 2026 Claims 1. Heated stray light shield (5) of an image acquisition device (1) for a motor vehicle for shielding a detection area (3b) of a camera (3) of the image acquisition device (1), wherein the stray light shield (5) is part of a housing part (4, 5) that surrounds a space area (6) and is intended to be arranged on the inside of a window (2) of the motor vehicle, so that the window (2) covers the space area (6) and the detection area (3b) extends through the space area (6) towards the window (2), and wherein the stray light shield (5) has a dimensionally stable plastic layer (9), an electric heating element (7) and a light-absorbing coating (8), characterized in thatthat the plastic layer (9) is only injection-molded onto the underside of the heating element (7) facing away from the room area (6) and the light-absorbing coating (8) is applied directly to the top side of the heating element (7) facing the room area (6) without a dimensionally stable intermediate layer.

2. Heated stray light aperture (5) according to claim 1 , characterized in that the heating element (7) is a heating film.

3. Heated scattering lens hood (5) according to claim 1 or 2, characterized in that the light-absorbing coating (8) is a light-absorbing paint.

4. Heated diffusing lens hood (5) according to claim 1 or 2, characterized in that the light-absorbing coating (8) is formed from fine, upright fibers a few millimeters high, which form a velvety, soft surface on the top of the heating element (7).

5. Heated lens hood (5) according to claim 4, characterized in that the top of the heating element (7) is coated with an adhesive layer (8a) and the fibers are held in the adhesive layer (8a) on the heating element (7).

6. Heated diffusing lens hood (5) according to claim 1 or 2, characterized in that the light-absorbing coating (8) is a velour made of fibers, in particular a velour fabric, laminated onto the top of the heating element (7) or a laminated film flocked with fibers.

7. Heated stray light aperture (5) according to claim 4, 5 or 6, characterized in that the fibers are upright.

8. Heated scattering lens hood (5) according to one of claims 4 to 7, characterized in that the fibers are black.

9. Image capture device (1) for a motor vehicle for intended arrangement on the inside of a window (2) of the motor vehicle, comprising a camera (3) with a detection area (3b) and a housing part (4, 5) that surrounds a space area (6) and is intended for arrangement on the inside of a window (2) of the motor vehicle, such that the window (2) covers the space area (6) and the detection area (3b) extends through the space area (6) in the direction of the window (2), characterized in that a part of the housing part (4, 5) forms a heated diffusing light diaphragm (5) according to one of claims 1 to 8.

10. Windshield of a motor vehicle with a heated scattering light visor (5) according to one of claims 1 to 8 or with an image capture device (1) according to claim 9.

11. Method for manufacturing a heated light shield according to one of claims 1 to 8, characterized in that the light-absorbing coating (8) is first applied directly to the top of the heating element (7) without a dimensionally stable intermediate layer, in particular laminated, and subsequently a plastic is injection-molded onto the underside of the heating element (7) facing away from the room area (6), so that the plastic layer (9) which gives the light shield (5) dimension stability is formed, which completely covers the underside, leaving the top of the heating element (7) facing the room area (6) and carrying the light-absorbing coating (8) uncovered, so that the coating (8) forms the top of the light shield (5) facing the room area (6) as intended.

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