Method for producing a composite pane for a motor vehicle, composite pane, and motor vehicle comprising a composite pane

Abstract

The invention relates to a method for producing a composite pane (8) for a motor vehicle (1). The composite pane comprises two pane elements (11, 12) which are arranged on opposite faces of a composite element (13), wherein the composite element (13) has a thickness course (D) along a surface (8b, 8c) of the composite pane (8). In order to produce the composite pane (8), a viewing region (9) of a surroundings camera (5) of the motor vehicle (1), said camera being arranged in the interior (2), is first determined. In an optimization routine, the imaging characteristic of the image of the surroundings (3) captured by the surroundings camera (5) is then compared with a specified target imaging characteristic for different thickness course profiles, and the result of the comparison is then used to determine a quality value for each imaging characteristic. On the basis of the quality values, the optimal thickness course for the composite element (13) is finally determined, said optimal thickness course being ascertained as a thickness course (D) at least in the viewing region (9).

Description

[0001] DESCRIPTION

[0002] Method for producing a composite pane for a motor vehicle, as well as a composite pane and a motor vehicle with a composite pane

[0003] The invention relates to a method for producing a composite pane for a motor vehicle. The invention also relates to a corresponding composite pane for a motor vehicle, as well as to a motor vehicle with a corresponding composite pane. The composite pane comprises a first pane element and a second pane element arranged on opposite sides of a composite element. The composite element has a thickness gradient relative to a surface of the composite pane.

[0004] Nowadays, a so-called laminated pane is commonly used for vehicle windows, such as windshields. A laminated pane is also known as laminated glass or laminated safety glass. A laminated pane is a laminate of at least two pane elements, such as glass panes, which are each bonded together by an intermediate layer, e.g., made of plastic. The intermediate layer can thus form a composite element. This results in a sandwich-like structure in which the glass panes represent opposing outer layers and the intermediate layer forms a middle layer.

[0005] The intermediate layer can be designed as a film, for example. As is well known, the intermediate layer fulfills a safety function: it has a puncture-resistant effect. This means that it can hold fragments together after the glass panes are damaged, for example, due to an accident. In particular, it prevents glass splinters from becoming detached. In addition to its safety function, the intermediate layer can also fulfill additional functions. For example, it can be used for sound insulation.

[0006] Another function can be to use the intermediate layer as an active optical element for a camera for environmental detection or environmental recognition of the motor vehicle. The camera can be installed in the interior of the motor vehicle and record the vehicle's surroundings or surroundings through the laminated glass.

[0007] US 2017 / 0341347 A1 discloses a composite pane whose intermediate layer is designed to prevent optical distortions of a camera image captured by a vehicle camera. For this purpose, the intermediate layer has a section opaque to visible light in an edge region of the camera's field of view. Furthermore, the composite pane can have a wedge-shaped basic shape in a cross-section along a surface, so that the composite pane tapers from an upper edge to a lower edge.

[0008] Another function for optical correction can be to use the intermediate layer to avoid double images or ghost images for a so-called head-up display (HUD) of a motor vehicle.

[0009] For this purpose, WO 2021 / 254910 A1 discloses a composite pane whose intermediate layer forms a wedge-shaped structure along a surface of the composite pane between a lower edge and an upper edge of the composite pane. Furthermore, the intermediate layer has a printed opaque layer in at least one area.

[0010] The object of the present invention is to provide a composite pane for a motor vehicle by means of which environmental detection can be carried out more reliably using a vehicle's environmental camera. This object is achieved by the subject matter of the independent patent claims. Advantageous developments of the invention are disclosed by the dependent patent claims, the description, and the figures.

[0011] The invention is based on the discovery that, using an optimization routine described below, the composite pane, in particular its intermediate layer, can be manufactured in such a way that the composite pane can be used as an active optical element to improve the environment detection of the environment camera. In particular, the intermediate layer is deliberately designed to be non-plane-parallel. This allows for a correction of the beam path of incident light in a camera's detection area to be realized in order to minimize astigmatism (lack of points) and coma (asymmetry error) in the environment detection caused by the composite pane.

[0012] To this end, the invention proposes a method for producing a composite pane for a motor vehicle. The composite pane comprises a first pane element and a second pane element, which are arranged on opposite sides of a composite element. The composite element can form the intermediate layer. The composite element has a thickness gradient, i.e. a change in thickness, relative along the surface of the composite pane. The manufacturing method comprises the following steps. First, a viewing area extending along the surface of the composite pane for at least one surroundings camera of the motor vehicle is determined. The surroundings camera is configured to capture a motor vehicle environment from an interior of the motor vehicle through the composite pane. An optimization routine is then carried out.In the optimization routine, the respective imaging characteristic of an image of the environment captured by the environment camera is first compared with a specified target imaging characteristic for different thickness profiles, i.e., two or more different thickness profiles. A quality value is then determined for each of the resulting imaging characteristics. The quality value indicates the degree of agreement between the respective imaging characteristic and the target imaging characteristic. Subsequently, an optimal thickness profile for the composite element is determined based on the determined quality values. Following the optimization routine, the optimal thickness profile is finally defined as the thickness profile, at least in the view-through area.

[0013] In other words, various thickness profiles are tested or tried out, and the associated imaging characteristics of the resulting environment image are recorded. The thickness profile is iterated or modified until the imaging characteristics correspond to the desired target imaging characteristics or at least approach it to a specified extent. By changing the respective thickness profile, a beam path of light captured by the environment camera can be corrected or, preferably, optimized.

[0014] Thus, optical correction can be achieved using the composite pane. The thickness of the composite element is precisely adapted to the camera's imaging properties. Optical distortions in the captured image of the surroundings or in the image data recorded by the surroundings camera, from which the surroundings image can be generated, can be reduced or avoided. This improves the detection of the surroundings using the surroundings camera. Detection of the surroundings can be performed more reliably.

[0015] The laminated pane is, in particular, a laminated glass pane. The laminated pane can be a vehicle pane that is at least partially transparent. For example, the laminated pane can be a vehicle window, such as a windshield, a rear window, or a side window. The laminated pane can comprise a plate-shaped base body. This means that an area of ​​two opposite main sides is much larger than an area of ​​an edge side that connects the main sides. Depending on a basic geometric shape of the laminated pane when viewed from a main side, the edge side can comprise one or more side edges. The respective main side can form the aforementioned surface of the laminated pane.

[0016] The pane elements can be glass panes, as commonly used in vehicles. The composite element forms an intermediate layer between the pane elements. The composite element connects the pane elements to one another. For example, the pane elements can be connected in a form-fitting manner, such as by bonding. The composite element can therefore be referred to as a connecting element. A cross-section of the composite pane along its surface results in a sandwich-like structure of the pane elements with the composite element.

[0017] The composite element can be designed, for example, as a film or plate made of plastic or resin. The composite element can be made of cast resin, for example, or be a highly tear-resistant, tough-elastic thermoplastic composite film. Materials and the production of a corresponding composite element, the pane elements, and / or the composite pane are known per se.

[0018] In this case, the thickness profile of the composite element refers specifically to a thickness change profile. This refers to a change in the cross-section or thickness of the connecting element along or parallel to the surface of the composite pane, and thus perpendicular to the stacking direction of the components of the composite pane. The thickness can determine the dimension in the stacking direction and thus the distance between the two pane elements.

[0019] From the perspective of the surroundings, the surround camera is located primarily behind the composite pane. The viewing area along the surface of the composite pane can be defined by the field of view of the surround camera and a distance between the surround camera and the composite pane. The viewing area can be limited by an intersection point of the field of view with the composite pane. The surround camera (hereinafter referred to as the camera) can be configured as a photo and / or video camera.

[0020] Cameras for environmental detection in motor vehicles are known.

[0021] The composite pane preferably comprises the thickness gradient only in the see-through region. This means that the thickness gradient is preferably locally limited. Alternatively, the thickness gradient can also extend outside the see-through region, i.e. in a predetermined region along the surface of the composite pane. The respective region comprising the thickness gradient is also referred to below as the correction region. Outside the correction region, the composite element can in particular not comprise any thickness gradient. This means that the composite element can be essentially planar at these points along the surface and preferably comprise essentially no change in thickness. Alternatively, the thickness gradient can extend along the entire surface of the composite pane.

[0022] The optimization routine can be used to describe and evaluate the composite pane system with or without the surround camera. This can be achieved, for example, through mathematical modeling or by creating a calculation model or creating a simulation model. For example, ray tracing or optical simulation can be used to infer the optical properties of the composite pane as a function of its thickness. As an alternative to modeling, the respective imaging characteristics of the surround camera can be recorded, for example, by conducting test drives with the vehicle. The composite pane can be changed or replaced for each test drive, with the composite panes each comprising composite elements with different thickness gradients.

[0023] In addition to the thickness profiles, other parameters of the composite pane can also be taken into account in the optimization routine. For example, a thickness or a thickness profile of the pane elements and / or a geometry or shape of the pane and / or a relative arrangement of the composite pane and the camera can be taken into account. As previously described, the optimal thickness profile is determined in the optimization routine by an actual-target comparison. In this process, the imaging characteristics as the actual state are compared with the target imaging characteristics as the target state. The respective imaging characteristics specify the properties of the image captured by the environmental camera. These properties can be, for example, sharpness, detail contrast, brightness, saturation and / or another previously known imaging property.The imaging characteristics can be determined by a setting of the camera, in particular an imaging optics of the camera (e.g. lens, shutter, image sensor, processor).

[0024] The target imaging characteristic can be referred to as the ambient characteristic. It specifies which properties of the ambient image or image data are desired, for example, for further processing. The target imaging characteristic can be based on empirical values. For example, the target imaging characteristic can be tailored to a human's perception of the environment that is perceived as particularly pleasant. For example, the target imaging characteristic can correspond to the average imaging characteristic of a healthy human eye.

[0025] The respective quality value indicates the degree of match. This means that the quality value can describe the image quality of the image characteristics relative to the target image characteristics. The degree of match refers to a deviation, i.e., a difference or difference between the image characteristics and the target image characteristics. This results in an approximate description of how well or accurately the environment is reproduced or replicated in the image.

[0026] Each quality value is assigned to a thickness profile that is checked in the optimization routine. Depending on the number of thickness profiles compared (thickness profiles), the actual-target comparison thus comprises two or more quality values. To determine the optimal thickness profile from the quality values, the quality values ​​can be compared with each other. This allows one quality value (optimal quality value) and the assigned thickness profile to be selected as the optimal thickness profile from the specified number of quality values. For example, a minimum or maximum value of all quality values ​​can be selected as the optimal quality value. Alternatively, a target quality value can be specified, and it can be checked which of the quality values ​​reaches the target quality value at least within a specified approximation range. The quality value can thus be determined empirically.

[0027] The described method can, of course, be extended to include a manufacturing routine. In the manufacturing routine, the composite pane, its components, or at least the composite element can be manufactured or produced.

[0028] For example, the composite element can be manufactured or machined to incorporate the respective thickness gradient. This means that the basic shape corresponding to the optimal thickness gradient can be formed. To manufacture the composite element, an ablative process can be used to remove excess material or an additive process. Examples of ablative processes include laser cutting, milling, or cutting. Examples of additive processes include stereolithography, laser beam melting, laser sintering, or electric arc melting.

[0029] The manufacturing or processing of the panel elements is carried out using conventional manufacturing techniques, which will not be discussed in detail below. For example, a conventional pressing process for pressing the components together can be used to assemble the composite element and the panel elements.

[0030] The method described above is preferably carried out by means of a control device. The control device can generate control data for controlling a manufacturing system for producing the composite pane or at least one of its components. The manufacturing system can carry out the corresponding manufacturing steps, i.e., the manufacturing or processing described above, when controlled by the control data. The control device can be comprised of a computer or a computer network. The control device can have a data processing device or a processor device configured to carry out an embodiment of the method according to the invention. For this purpose, the processor device can have at least one microprocessor and / or at least one microcontroller and / or at least one FPGA (Field Programmable Gate Array) and / or at least one DSP (Digital Signal Processor).Furthermore, the processor device can comprise program code configured to implement the embodiment of the method according to the invention when executed by the processor device. The program code can be stored in a data memory of the processor device.

[0031] The data storage medium can be designed as a computer-readable storage medium. The storage medium can comprise the program code which, when executed by a computer or a computer network, causes the computer or computer network to carry out an embodiment of the method according to the invention. The storage medium can, for example, be provided at least partially as a non-volatile data storage device (e.g., as a flash memory and / or as an SSD - solid state drive) and / or at least partially as a volatile data storage device (e.g., as a RAM - random access memory). The storage medium can be implemented in the processor circuit in its data storage device. Additionally or alternatively, the storage medium can, for example, be operated as a so-called app store server on the Internet. The program code can be provided as binary code or assembler and / or as source code of a programming language (e.g., C) and / or as a program script (e.g., Python).

[0032] The invention also includes embodiments which provide additional advantages.

[0033] According to one embodiment, according to the optimization routine for

[0034] To determine the respective quality value and thus, in particular, the optimal thickness profile, a modulation transfer function of the surrounding camera is determined or calculated. This has the advantage that the optimal thickness profile can be determined particularly easily.

[0035] A modulation transfer function (MTF) is a well-known means of comparing the performance or imaging quality of an optical system. The MTF of a lens of an environmental camera is, in particular, a measure of the ability of the imaging optics to transfer a contrast at a specific resolution of objects in the environment to the resulting image. In other words, the MTF is a way of specifying a relationship between resolution and contrast (particularly detail contrast) of an image in a single specification. The imaging characteristic can include, for example, a camera resolution and a camera (detail) contrast as properties. The target imaging characteristic can therefore include, accordingly, an object resolution and an object (detail) contrast for a respective object to be imaged in the environment.

[0036] According to a further embodiment, the optimization routine additionally determines the respective quality value as a function of the angle of incidence of the composite pane, in particular a plane forming the surface of the composite pane, relative to an image capture plane of the surrounding camera. This offers the advantage that imaging errors, such as coma, resulting from the angle of incidence can be compensated.

[0037] The image capture plane refers specifically to the plane of the surround camera that forms the light incidence or light capture area of ​​the surround camera. This plane can, for example, be perpendicular to the optical axis. The image capture plane can, for example, be provided by the exterior of an object of the surround camera.

[0038] According to a further embodiment, the respective quality value is additionally determined according to the optimization routine as a function of the curvature of the composite pane along its surface. Thus, imaging errors resulting from the pane curvature can be compensated for by means of the composite element.

[0039] The curvature can, for example, be local or global. Global curvature in this case refers to a curvature that a vehicle window exhibits in a given installation position in the motor vehicle, in a conventional manner, between two opposite edges. Local curvature in this case refers in particular to local bending defects, such as waviness along the surface of the window. Local bending defects can arise, for example, if the composite window exhibits shape defects after production.

[0040] According to a further embodiment, the composite element comprises a thickness profile which, in a cross section perpendicular to the surface, has a concave and / or convex basic shape at least in the see-through area.

[0041] This has the advantage that the function of a lens can be simulated using the composite element.

[0042] In other words, at least one or both of the respective contact surfaces of the composite element with the respective first or second disc element have a concave or convex profile along the surface. For example, the composite element can have a biconcave, plano-concave, concavo-convex, biconvex, plano-convex, convex-concave, or meniscus-shaped basic shape.

[0043] According to a further embodiment, the composite element comprises a thickness gradient which, in a cross-section perpendicular to the surface, has one end with a smaller thickness than the other end, at least in the see-through area. This makes it possible to compensate for an optical offset of a beam path through the composite pane, which arises due to the two pane elements. For this purpose, the composite element can have a wedge-shaped basic form. A so-called wedge angle specifies the wedgeness of the composite element, i.e. the size of the thickness change along the surface. The thickness can decrease along the surface towards one end or increase towards the other end. In other words, the two opposite contact surfaces of the composite element can run obliquely to the surface. Along the surfaces, the contact surfaces can, for example, run towards or away from each other.Preferably, the thickness gradient can increase or decrease constantly along the surface. Alternatively, the contact areas can, for example, extend exponentially or logarithmically along the surface.

[0044] According to one aspect of the invention, a different predefined basic shape can also be determined. The respective basic shape depends on the optical properties of the camera and the composite pane. The basic shape can, for example, be a hybrid of the aforementioned basic shapes.

[0045] According to a further embodiment, two or more, preferably exactly two or exactly three, regions with different thickness profiles are provided for the composite element. The composite element can thus comprise several of the aforementioned correction regions. Each (correction) region with the associated thickness profile is assigned to a surroundings camera. The motor vehicle can thus comprise several, i.e., two or more than two, surroundings cameras. The surroundings cameras can be arranged at different positions in the interior. This results in several viewing regions at different locations along the surface of the composite pane.

[0046] The correction regions or see-through regions can be arranged next to one another along the surface of the composite pane. For example, the correction regions can be directly adjacent to one another. Alternatively, the correction regions can be separated by planar regions. In a cross-section perpendicular to the surface, the composite element thus comprises two adjacent thickness profiles that are connected by a planar profile. According to a further embodiment, a transparent region enclosed by an opaque region is provided for the composite element in the respective see-through region. The opaque region delimits the see-through region for the respective surroundings camera. This means that the see-through region is restricted, downsized, or reduced by means of the opaque region. This results in a restricted see-through region. This allows image edge errors at edge regions of the surroundings image to be compensated for or corrected.

[0047] The opaque area can be a predefined edge area of ​​the see-through area. To create the opaque area, the composite element can, for example, be colored or coated with an opaque coating.

[0048] Transparent or opaque in this case refers to the light transmittance or non-transmittance for an electromagnetic spectrum of light that can be perceived by a person (usually about 380 to 780 nanometers).

[0049] In this context, opaque preferably means substantially completely (100 percent) opaque. In particular, the opaque region can be at least more than 70 percent, preferably more than 90 percent, particularly preferably 97 to 99 percent opaque. Transparent in this context preferably means substantially completely (100 percent) translucent. The transparent region can in particular be at least more than 70 percent, preferably more than 90 percent, particularly preferably 97 to 99 percent translucent.

[0050] According to a preferred aspect, the composite element can be formed from multiple parts. This means that the composite element can comprise a plurality of layered components perpendicular to the surface, i.e. along the stacking direction. The layered components can be designed or shaped analogously to the composite element, i.e. as previously described. In the assembled state, the layered components can form or result in the composite element. At least one of the layered components can implement the optical correction function. At least one further layered component can provide a function other than optical correction. For example, at least one of the layered components can provide acoustic damping (sound absorption), a coloring function, or a shading function. For example, the opaque and transparent regions can be implemented by one of the layered components.

[0051] For use cases or application situations that may arise during the method and which are not explicitly described here, it may be provided that, in accordance with the method, an error message and / or a request to enter user feedback is issued and / or a default setting and / or a predetermined initial state is set.

[0052] The invention also relates to a composite pane for a motor vehicle. The composite pane comprises a first pane element and a second pane element arranged on opposite sides of a composite element. The composite element has a thickness profile relative to a surface of the composite pane. The thickness profile extends at least in a viewing area of ​​at least one surroundings camera of the motor vehicle, said viewing area extending along the surface of the composite pane. The surroundings camera is configured to capture a motor vehicle environment through the composite pane from an interior of the motor vehicle. The thickness profile is defined as an optimal thickness profile determined according to an optimization routine.

[0053] Preferably, the optimal thickness profile can be determined, for example, using the optimization routine described above. In particular, the optimal thickness profile can be determined as a function of the modulation transfer function of the surrounding camera.

[0054] The composite pane or the thickness profile of the composite element can thus be manufactured using a method as described above. The method described above can thus be used to manufacture the composite pane. The invention also relates to a motor vehicle with at least one surround camera and at least one composite pane as described above. The surround camera is configured to capture the surroundings of the motor vehicle from an interior of the motor vehicle through the composite pane.

[0055] The surround-view camera can, for example, be included in a driver assistance system of the motor vehicle. The driver assistance system can be an electronic vehicle guidance system. The driver assistance system can, for example, be used for the (semi-)automatic and / or (semi-)autonomous guidance or control of the motor vehicle. To implement the vehicle guidance function, a control device of the driver assistance system can evaluate or process the surrounding image, in particular the image data from the surround-view camera. The surrounding image from the surround-view camera can, for example, be evaluated using a known pattern recognition algorithm. This allows objects, obstacles, or markings in the environment to be recognized. Depending on this, the control device can control a drive device, such as a drive train, a steering system, or a braking system, with corresponding control data.By controlling the vehicle, a driving maneuver can be carried out automatically or autonomously or at least partially automatically or partially autonomously.

[0056] The motor vehicle according to the invention is preferably designed as a motor vehicle, in particular as a passenger car or truck or as a passenger bus or motorcycle.

[0057] The invention also includes further developments of the composite pane according to the invention and the motor vehicle according to the invention, which have features as already described in connection with the further developments of the method according to the invention. For this reason, the corresponding further developments of the composite pane according to the invention and the motor vehicle according to the invention are not described again here. The invention also encompasses combinations of the features of the described embodiments. The invention therefore also encompasses implementations that each have a combination of the features of several of the described embodiments, unless the embodiments have been described as mutually exclusive.

[0058] Exemplary embodiments of the invention are described below. Shown are:

[0059] Fig. 1 is a schematic representation of a motor vehicle with an environment camera and a windshield which is designed as a composite pane and provides an active imaging optics for the environment camera,

[0060] Fig. 2 is a schematic representation of the windshield in a front view,

[0061] Fig. 3a is a schematic representation of a cross section of the windshield with an advantageous design of a composite element according to an advantageous embodiment;

[0062] Fig. 3b is a schematic representation of a cross section of the windshield with an advantageous design of the composite element according to a further advantageous embodiment;

[0063] Fig. 3c is a schematic representation of a cross section of the windshield with an advantageous design of the composite element according to a further advantageous embodiment;

[0064] Fig. 3d is a schematic representation of a cross-section of the windshield with an advantageous design of the composite element according to a further advantageous embodiment;

[0065] Fig. 3e is a schematic representation of a cross section of the windshield with an advantageous design of a composite element according to a further advantageous embodiment;

[0066] Fig. 4 is a schematic process flow diagram for a method for producing the composite pane.

[0067] The exemplary embodiments explained below are preferred embodiments of the invention. In the exemplary embodiments, the described components of the embodiments each represent individual features of the invention that can be considered independently of one another, each of which also develops the invention independently of one another. Therefore, the disclosure is intended to encompass combinations of the features of the embodiments other than those shown. Furthermore, the described embodiments can also be supplemented by further features of the invention already described.

[0068] In the figures, the same reference symbols designate elements with the same function.

[0069] Fig. 1 shows a schematic side view of a motor vehicle 1. The motor vehicle 1 is designed, for example, as a passenger car.

[0070] The motor vehicle 1 comprises a windshield 8a, which in this case is designed as a so-called composite pane 8. In the present exemplary embodiment, the composite pane 8 is shown in a sectional view from the side. The composite pane 8 forms a known laminated safety glass. The composite pane 8 comprises a first pane element 11 and a second pane element 12, which are designed, for example, as glass panes, as are commonly used in the automotive sector.

[0071] The composite pane 8 also comprises a composite element 13. The composite element 13 connects the first and second pane elements 11, 12 to one another. The pane elements 11, 12 are arranged on opposite sides of the composite element 13. In the cross-sectional view according to Fig. 1, a sandwich-like structure of the composite pane 8 thus results in a vehicle longitudinal direction L of the motor vehicle 1.

[0072] The composite element 13 can be formed, for example, as a tear-resistant and tough-elastic film, such as that used in laminated safety glass. The composite element 13 can be made, for example, from PVB (polyvinyl butyl rubber). However, other transparent materials, such as PET (polyethylene terephthalate), a silicone or silicone compound, or an amorphous plastic, can also be used as materials for the composite element 13. The pane elements 11, 12 are preferably laminated or bonded to one another by means of the composite element 13.

[0073] The composite pane 8 is installed in a predetermined installation position in Fig. 1 and has a structure that is usual for windshields.

[0074] In particular, the composite pane 8 essentially has a plate-shaped structure or a plate-shaped base body. This means that the composite pane 8 has two opposing surfaces 8b, 8c, which are connected to one another via a respective edge 10 or side edge. The respective edge 10 has a much smaller area than the respective surfaces 8b, 8c. In the present exemplary embodiment, the surfaces 8b, 8c define a plane that extends along a vehicle vertical direction H and a vehicle transverse direction Q.

[0075] In the present exemplary embodiment, surface 8b is provided, for example, by pane element 11 and surface 8c by pane element 12. Surface 8b forms an outer side 10a of composite pane 8. This means that surface 8b faces an environment 3 of motor vehicle 1. In particular, outer side 10a directly borders the environment. Surface 8c forms an inner side 10b of composite pane 8. Surface 8c accordingly faces an interior 2 of motor vehicle 1. This means that inner side 10b directly borders the interior 2 of motor vehicle 1.

[0076] In the present exemplary embodiment, the composite pane 8 is essentially rectangular in a view of one of the surfaces 8b, 8c (see also Fig. 2) and thus has four edge sides 10. Two of the edge sides 10, which are arranged opposite one another in the vehicle's vertical direction H, form a lower edge 10c and an upper edge 10d. The remaining two edge sides 10, which are arranged opposite one another in the vehicle's transverse direction Q, form a side edge 10e and a side edge 10f.

[0077] In addition to the composite pane 8, the motor vehicle 1 also comprises an environment camera 5. The environment camera 5 can, for example, be assigned to a driver assistance system 7 of the motor vehicle. The driver assistance system 7 can, for example, be used for semi-automatic or semi-autonomous or fully automatic or fully autonomous control or operation of the motor vehicle 1. For this purpose, the driver assistance system 7 can capture image data 7a from the environment camera 5. The image data 7a can describe or include an environment 3 of the motor vehicle 1, in particular objects or markings in the environment 3. The image data 7a thus provide a replica of the objects in the environment 3. The driver assistance system 7 can evaluate or process the image data 7a in a known manner in order to calculate and initiate driving maneuvers for the motor vehicle 1.The driver assistance system 7 may, for example, include an autopilot or a lane keeping assist system or a sign recognition system.

[0078] For environmental detection, the environmental camera 5 is arranged in the interior 2 of the motor vehicle 1. The environmental camera 5 is thus designed to capture the image data 7a and to capture the environment 3 of the motor vehicle 1 through the windshield 8a. The environmental camera 5 can be designed as a video camera or photo camera, as is known in the automotive sector for environmental detection. To capture the environment 3, the environmental camera 5 can capture an (environmental) image, for example a photo or video, of the environment 3. The image can be in the form of image data 7a. With suitable processing by a display device, such as a screen or a display, the image can be reconstructed from the image data 7a and displayed for a person. The terms image and image data 7a can be used synonymously below.

[0079] The surround camera 5 can typically only capture a predefined section of the surroundings 3. This section is defined by a so-called field of view, i.e., a detection range 6 or a field of vision of the surround camera 5. Only those objects in the surroundings 3 that lie within the detection range 6 can be included in the image. In the present case, a traffic sign 4 indicating a speed limit is shown as an example of such an object.

[0080] In the interior space 2, the surround camera 5 is arranged at a predetermined distance A from the composite pane 8. Depending on the distance A and the detection area 6, a viewing area 9 extending along the respective surface 8b, 8c results on the composite pane 8. The viewing area 9 is limited or predetermined by the dimensions of the detection area 6 at the intersection point with the composite pane 8.

[0081] According to Fig. 1, the composite pane is curved at least along the vehicle's vertical direction H. This means that the outer side 10a and the inner side 10b are curved or bent. This results in a curvature 16 or a curvature profile of the composite pane 8, at least in the viewing area 9.

[0082] In addition, the composite pane 8 is tilted relative to an image capture plane 5a of the surround camera 5 in the illustrated installation position. This results in a predetermined angle of incidence a between the image capture plane 5a and the respective surface 8c, 8b. The image capture plane 5a is configured, for example, as the light incident surface or the outer side of a lens, i.e., an imaging lens, of the surround camera 5.

[0083] In particular, due to the curvature 16 and the inclination, as well as the formation of interfaces for ambient light formed by the components (disk elements 11, 12, composite element 13) of the composite disc 8, imaging errors such as astigmatism or coma can arise in the image. The composite disc 8 is now to be designed so that these imaging errors can be corrected, in particular, minimized.

[0084] The correction is intended to address at least two different types of aberrations. Firstly, optical distortions in an edge region of the viewing area 9 are to be compensated or avoided. Secondly, the detection of the surroundings by the surroundings camera 5 is to be made more reliable, in particular, improved. This means, for example, that the sharpness and contrast of the image are to be adapted to the real surroundings.

[0085] For distortion correction, the composite pane 8 comprises an opaque, i.e., light-impermeable, region 14 in the see-through region 9, which restricts or limits the see-through region 9. The opaque region 14 is arranged in an edge region of the see-through region. The opaque region 14 encloses or limits a transparent region 15. The transparent region 15 is encompassed by a partial region of the see-through region 9. The transparent region 15 can provide a limited see-through region 9a for the surroundings camera 5. The surroundings camera 5 can thus only capture the surroundings 3 through the transparent region 15. The surroundings camera 5 cannot capture the surroundings 3 through the opaque region 14.

[0086] To provide the opaque region 14, the composite element can, for example, be colored or printed or provided with an opaque layer in the corresponding region. Fig. 2 shows, by way of example, how the opaque region 14 can be designed from a front view of the composite pane 8. Front view means that the composite pane 8 is shown from the outside 10a. From the front view, the opaque region 14 forms a trapezoidal basic shape along the vertical direction of the vehicle. The transparent region 15 is cut out of the surface of the opaque region 14 with a similar shape. In order not to obstruct the field of vision of a driver when operating the motor vehicle 1, the opaque region 14 is arranged on the upper edge 10d of the composite pane 8.

[0087] To improve environmental detection, the composite element 13 is designed such that it has a thickness gradient D, i.e., a change in thickness, along the respective surface 8b, 8c. Thus, the composite element 13 has a geometry that deviates from a plane-parallel surface, with at least one thickness change in one direction and / or an additional thickness change in at least one other direction.

[0088] The thickness change is preferably designed so that it does not lead to a so-called double image angle in the viewing area 9, 9a relevant for the environment camera 5, and at the same time is suitable for correcting astigmatism and coma. In particular, the double image angle should be less than 12 minutes. By incorporating the composite element 13 with the thickness gradient D, the composite pane 8 can form an active optical element for the environment camera 5. In particular, a beam path of incident light can be corrected or adjusted so that the environment camera 5 can capture a sharp and high-contrast image of the environment 3.

[0089] 3a, 3b, 3c, 3d, 3e show exemplary configurations for the geometric basic body of the composite element 13. Figs. 3a to 3e show the composite pane 8 according to Fig. 2 in an exploded view according to a cross-section along a section line AA. According to Fig. 3a, the composite element 13 is wedge-shaped. This means that in the cross-section perpendicular to the respective surface 8c, 8d, the composite element 13 comprises one end with a smaller thickness than the other end. The wedge shape is predetermined by a wedge angle ß. The two opposite contact surfaces 13a and 13b of the composite element thus run obliquely along the surfaces 8c, 8b.

[0090] According to the embodiment in Fig. 3b, the composite element 13 has the shape of a diverging lens. This means that the composite element comprises a concave, in particular a biconcave, base body.

[0091] According to the embodiment in Fig. 3c, the composite element 13 has the shape of a converging lens. This means that the composite element 13 comprises a convex, in particular a biconvex, base body.

[0092] According to the embodiment in Fig. 3d, the composite element 13 comprises a wedge-shaped basic shape extending in several directions. The opposing contact surfaces 13a and 13b converge in a central region and diverge toward the ends. The thickness thus varies radially around the central region.

[0093] According to the exemplary embodiment in Fig. 3e, the composite element 13 is constructed in multiple parts, in the present case, for example, in two parts. The composite element comprises two composite element parts 13c and 13d or layered components. The composite element part 13d is designed analogously to the composite element 13 according to Fig. 3a. This means that the composite element part 13d comprises a wedge-shaped base body. In contrast, the composite element part 13d is designed to be plane-parallel. Its thickness essentially does not vary along the respective surface 8c, 8b. The composite element parts 13c and 13d can, for example, provide different functions. The composite element part 13d can, for example, implement the previously described improvement in environmental detection. The functional element 13c can, for example, have sound-insulating properties or, for example, perform a shading function.Of course, the composite element 13 can also be composed of more than two composite element parts 13c, 13d.

[0094] Figs. 3a to 3e show only exemplary embodiments of the geometric shape of the composite element 13. Of course, geometric shapes other than those shown, in particular mixed forms thereof, are also possible.

[0095] Furthermore, it can also be provided that the motor vehicle 1 comprises more than one surroundings camera 5 and the composite pane 8 thus comprises more than one correspondingly assigned viewing area 9. Accordingly, the composite element 13 can, for example, comprise several thickness gradients or thickness gradient profiles at least in the respective viewing area 9. The thickness gradients D can, for example, directly adjoin one another along the respective surface 8b, 8c or be separated, for example, by plane-parallel regions of the composite element 13.

[0096] The respective thickness profile D can extend along the entire surface of the composite pane 8. Alternatively, the respective thickness profile can be adapted, for example, only to the viewing area 9 or to a predetermined correction area of ​​the composite pane 8, which can be larger or smaller than the viewing area 9.

[0097] In order to implement the desired correction function, the composite pane 8 is manufactured according to a specified manufacturing process. This involves, in particular, adapting the thickness profile D to the optical properties of the surrounding camera 5.

[0098] Fig. 4 shows a schematic process flow diagram for a corresponding manufacturing process. In a step S1, the viewing area 9 of the respective surroundings camera 5 extending along the surface 8b, 8c of the composite pane 8 is determined. Subsequently, in a step S2, an optimization routine is carried out. In the optimization routine, in a step S2.1, the imaging characteristic of the image captured by the surroundings camera 5 is compared with a predetermined target imaging characteristic for different thickness profiles, i.e., thickness gradients, of the composite element 8. This means that, for example, the thickness gradient can be repeatedly adjusted in several iteration steps, and then the respectively assigned imaging characteristic can be determined. For example, two or more, preferably more than 10, in particular more than 100 different thickness gradients can be tested.

[0099] In this case, the term "image characteristic" refers to the properties of the image, such as sharpness, detail contrast, brightness, and / or saturation. The target image characteristic can also be referred to as the ambient characteristic. The target image characteristic specifies a target state for the image characteristic (actual state). This means that the target image characteristic specifies the desired properties of the image. The target image characteristic can, for example, be derived from empirical values ​​for a person's perception that is perceived as particularly pleasant.

[0100] The optimization routine then continues in step S2.2. In step S2.2, a quality value is determined for the respective imaging characteristic. Each thickness profile is thus assigned a quality value. The quality value indicates the degree of agreement between the imaging characteristic and the target imaging characteristic. This makes the different thickness profiles comparable.

[0101] The optimization routine then continues in step S2.3. In step S2.3, an optimal thickness profile for the composite element is determined based on the determined quality values. A quality value (optimal quality value) is thus selected from the multitude of quality values, and the associated thickness profile is defined as the optimal thickness profile. For example, a minimum or maximum value of the quality values ​​can be selected. Alternatively, the quality value that corresponds to a predefined target quality value or lies within a predefined quality value range can be selected. The optimization routine can be determined, for example, by modeling, i.e., by creating a calculation model or a simulation model, of the system comprising the composite pane 8 and the surrounding camera 5. Preferably, a so-called modulation transfer function (MTF) of the surrounding camera 5 is determined to carry out steps S2.1 and S2.2.The MTF is a well-known means of specifying the resolution and contrast of a camera compared to a desired image in a single specification.

[0102] After performing the optimization routine, the method continues in step S3. In step S3, the optimal thickness profile is defined as the thickness profile at least in the view-through region 9.

[0103] The composite element can then be manufactured or produced with the desired optimal thickness profile. This can be done, for example, using abrasive or build-up processes. After the panel elements 11, 12 have been manufactured using known manufacturing techniques, the composite element 13 and the panel elements 11, 12 can also be assembled together in a known manner.

[0104] To carry out the method described in Fig. 4, a control device, such as a microcontroller or microprocessor, can be used. The control device can provide at least the defined optimal thickness profile in the form of control data to a manufacturing system, such as a manufacturing robot, in order to control it for the production of the composite element and / or the entire composite pane 8.

[0105] Overall, the previously described embodiments thus show an arrangement and design of a windshield for improved image recognition or image sensor technology behind a vehicle window.

Claims

PATENT CLAIMS Method for manufacturing a composite disc (8) for a motor vehicle (1) , wherein the composite disc (8) comprises a first disc element (11 ) and a second disc element (12) arranged on opposite sides of a composite element (13) wherein the composite element (13) has a thickness gradient (D) relative to a surface (8b, 8c) of the composite disc (8) , wherein the method comprises the following steps: - Determining a line extending along the surface (8b, 8c) of the composite windscreen (8) extending viewing area (9) of at least one surrounding camera (5) of the motor vehicle (1) which is designed to capture an environment (3) of the motor vehicle (1) from an interior (2) of the motor vehicle (1) through the composite windscreen (8), - in an optimization routine: • Comparing a respective imaging characteristic of an image of the environment (5) captured by means of the environment camera (5) with a specified target imaging characteristic for different thickness profiles, • Determining a quality value for the respective imaging characteristic, which indicates a degree of agreement between the imaging characteristic and the target imaging characteristic, • Determining an optimal thickness profile for the composite element (13) depending on the determined quality values, - Defining the optimal thickness profile as the thickness profile (D) at least in the transparent area (9). Method according to claim 1, wherein a modulation transfer function of the ambient camera (5) is determined according to the optimization routine for determining the respective quality value. Method according to any one of the preceding claims, wherein According to the optimization routine, the respective quality value is additionally determined as a function of an angle of inclination (a) of the composite disc (8) relative to an image acquisition plane (5a) of the ambient camera (5).

4. Method according to one of the preceding claims, wherein, according to the optimization routine, the respective quality value is additionally determined as a function of a curvature (16) of the composite disk (8) along the surface (8b, 8c).

5. Method according to one of the preceding claims, wherein the composite element (13) comprises a thickness gradient (D) which in a cross-section perpendicular to the surface (8b, 8c) has a concave and / or convex basic shape at least in the transparent area (9).

6. Method according to one of the preceding claims, wherein the composite element (13) comprises a thickness gradient (D) which, in a cross-section perpendicular to the surface (8b, 8c), has at least in the transparent area (9) one end with a lesser thickness than another end.

7. Method according to one of the preceding claims, wherein two or more areas with different thickness gradients (D) are provided for the composite element (13) for different environmental cameras (5).

8. Method according to one of the preceding claims, wherein for the composite element (13) in the respective viewing area (9) a transparent area (15) enclosed by an opaque area (14) is provided, wherein the opaque area (14) limits the viewing area (9) for the respective environmental camera (5).

9. Composite disc (8) for a motor vehicle (1) , wherein the composite disc (8) comprises a first disc element (11) and a second disc element (12) which are located on opposite sides of a composite element (13) are arranged, wherein the composite element (13) has a thickness profile (D) relative to a surface (8b, 8c) of the composite disk (8), characterized in that the thickness profile (D) is at least in one area extending along the surface (8b, 8c) the viewing area (9) of the composite glass (8) extends to at least one surround view camera (5) of the motor vehicle (1), wherein the surround view camera (5) is configured to capture an environment (3) of the motor vehicle (1) through the composite glass (8) from an interior (2) of the motor vehicle (1), and the thickness profile (D) is defined as an optimal thickness profile determined according to an optimization routine. Motor vehicle (1) with at least one surround view camera (5) and at least one composite glass (8) according to claim 9, wherein the surround view camera (5) is designed to detect the surroundings (3) of the motor vehicle (1) from an interior (2) of the motor vehicle (1) through the composite screen (8).

Images