Motor vehicle display device for the interior of a motor vehicle, motor vehicle comprising at least one motor vehicle display device and method for operating a motor vehicle display device

Abstract

The invention relates to a vehicle display device (10) for the interior of a motor vehicle, comprising a planar transparent display (12) with a display area (14), wherein a switchable layer (22) is arranged on a surface of the display (12) opposite the display area (14), the transmittance of which is variable. On the side of the switchable layer (22), a planar light guide (26) is arranged spaced apart from the switchable layer (22) by a cavity (24), wherein the planar light guide (26) is configured to emit light from at least one light source via an exit surface (30) in the direction of the transparent display (12). The planar light guide (26) comprises at least one connection (28) for at least one light source, wherein the at least one connection (28) is arranged on the circumference of the planar light guide (26).

Description

[0001] The invention relates to a motor vehicle display device for the interior of a motor vehicle, a motor vehicle comprising at least one motor vehicle display device, and a method for operating a motor vehicle display device.

[0002] In order to display at least some information in a motor vehicle, particularly in its interior (hereinafter referred to as the vehicle interior), it may be necessary to provide at least one vehicle display device (hereinafter also referred to simply as the display device). Various display devices with different functionalities are known from the prior art.

[0003] An example of a display device for a means of transport is given in German patent application DE 10 2022 205 083 A1, wherein this display device comprises a display panel and backlighting. The backlighting is provided by a reflector with a plurality of reflectively designed cavities and light sources arranged in each cavity. A disadvantage of this device is that it is not possible to see through the display device.

[0004] This disadvantage can be overcome by using a transparent display as a display device, as is known from the prior art and is used, for example, in augmented reality glasses and / or head-up displays. A transparent display is characterized by the fact that at least some information can be displayed on its surface, but it is also possible to see through the transparent display. For example, German patent application DE 31 20 601 A1 discloses a transparent display as a display device for a motor vehicle, whereby the structure and / or functionality of the transparent display is not limited to that disclosed in the cited patent application.

[0005] A disadvantage of transparent displays, particularly those based on LEDs (light-emitting diodes) or OLEDs (organic LEDs) and known from the prior art, is that dark and / or black pixels cannot be generated. In non-transparent displays, these are created, for example, by the absence of light (i.e., dark or black pixels can be generated in non-transparent displays by, for example, not emitting light for the pixel). This is because, in transparent displays, light elements are projected onto a transparent background. Dark and / or black pixels are understood to be pixels that, within the limits of technical possibility, do not emit light, for example, to enable the representation of black elements on the display.The problem of producing dark and / or black pixels can be remedied, for example, by using a darkening layer behind the transparent display. However, this reduces the transparency of the display, i.e., its transmittance, which describes the ratio of light passing through the display and / or the display device to the incident light.

[0006] DE 10 2021 200 857 A1 discloses a display element with reduced backlighting in the edge area.

[0007] DE 10 2021 213 134 A1 discloses a display device for a passenger in a vehicle comprising an anti-reflective layer that reduces a proportion of scattered light in the light emitted by a display element.

[0008] US Patent 2010 / 0177025A1 discloses a display device comprising a light guide, wherein the light guide includes a light control mirror that transmits or reflects light depending on a control signal.

[0009] DE 10 2005 033 982 A1 discloses a display unit, wherein light from a light source can be shone laterally into a light guide arranged behind the display surface as seen from a viewer of a display surface, for the purpose of illuminating the display surface, wherein the light guide is arranged with a free space to a circuit board.

[0010] EP 3 590 751 B1 discloses a method for operating a display device, wherein a display area of ​​the display device comprises several predetermined sub-areas whose degree of transparency is adjustable.

[0011] EP 2 024 198 B1 discloses a vehicle display device comprising a display device and a transparent display input device, wherein the transparent display input device is to be installed outside the dashboard between the display device and a driver of the vehicle.

[0012] DE 10 2018 221 545 A1 discloses a projection device for an instrument panel for a motor vehicle comprising a display surface having two areas. A first area is arranged between a viewer of the display surface and an instrument panel, and the second area is arranged at least partially above the instrument panel for the viewer of the display surface.

[0013] The object of the invention is to provide a display device that is as transparent as possible, but can still display black and / or dark pixels.

[0014] The problem is solved by the subject matter of the independent patent claims. Advantageous embodiments of the invention are described by the dependent patent claims, the following description, and the figures.

[0015] The invention provides a solution comprising a motor vehicle display device, hereinafter also referred to as a display device, for the interior of a motor vehicle (vehicle interior). The display device comprises a flat, transparent display (hereinafter also referred to as the display) with a display area. The display area is specifically designed for displaying content to be shown by the display device. This means, for example, that content to be shown on the display device is displayed on the display area of ​​the display device for at least one occupant of the vehicle and / or is visible on the display area of ​​the display device to the at least one occupant of the motor vehicle. This specifically means that the display area is a surface of the display device facing the at least one occupant.In the present case, "surface" means that the extent in at least one distinguished direction, preferably the direction perpendicular to the display surface, is less than in the directions perpendicular to the distinguished direction. In particular, the extent in the distinguished direction is significantly less, for example, a maximum of 10%, more specifically a maximum of 1%, preferably a maximum of 0.1%, than the extent in the direction perpendicular to the distinguished direction.

[0016] On a surface of the display opposite the display area, in particular on the back of the display area and / or on a surface of the transparent display that has the opposite orientation to the display area, a switchable layer is applied whose transmittance can be changed and / or regulated. The switchable layer is known from the prior art, and the switchable layer can be a glass and / or a film, which, as glass, may also be known as smart glass and / or switchable glass. In particular, the switchable layer is a layer, preferably tintable, for example a film and / or a glass, whose light transmittance and / or transmittance can be changed, for example, by applying an electrical voltage and / or by changing the lighting conditions and / or by heating.The switchable layer allows dark and / or black pixels to be realized on the display by reducing the transmission level of the switchable layer, which in particular can create and / or set a darker and / or black background behind the transparent display.

[0017] On the side of the switchable layer, a planar optical fiber (hereinafter also referred to as the optical fiber) is arranged, spaced apart from the switchable layer by a cavity. The cavity can have a thickness of between 1 cm and 30 cm, in particular between 5 cm and 20 cm. This means that the distance between the switchable layer and the optical fiber can be a maximum of 30 cm, in particular a maximum of 20 cm, and / or at least 1 cm, in particular at least 2 cm, preferably at least 5 cm. The cavity is in particular filled with air and / or a gas. This means in particular that, due to the cavity, the planar optical fiber does not touch and / or only touches the display and / or the switchable layer in partial areas of the optical fiber.The cavity offers the advantage that heat from the light guide and / or the transparent display and / or the flat layer can be dissipated particularly effectively, thus preventing overheating and subsequent failure of the display device. Additionally or alternatively, the cavity can make the vehicle interior appear larger, especially when the display is switched off, since it is not the display itself, but rather an area located behind the cavity and / or the light guide that visually limits the vehicle interior.

[0018] The planar light guide is configured to emit light from at least one light source via an exit surface in the direction of the transparent display. The planar light guide includes at least one connection for at least one light source, and this connection is located on the circumference of the planar light guide. This means that the connection for introducing light into the planar light guide is located on at least one side surface of the light guide. The side surface of the planar light guide is, in particular, a surface that differs from the exit surface. Additionally, the side surface can differ from a rear surface opposite the exit surface and / or have an orientation opposite to the exit surface. In particular, the side surface has a smaller area than the exit surface and / or is perpendicular to the exit surface.The optical fiber is thus designed to guide light from at least one light source, which is introduced, in particular, laterally onto the optical fiber and / or onto at least one side surface of the optical fiber, within the optical fiber and emit it via an exit surface. Within the optical fiber, the light may be reflected at least once, for example, on the inner surface of the optical fiber, such as the inner surface of the back surface and / or exit surface. The light can be coupled out of the optical fiber via a microstructure on the surface of the optical fiber. Alternatively, the light may be propagated parallel to the exit surface through the optical fiber, in particular until it encounters at least one scattering center, through which the light is scattered out of the optical fiber.In particular, the light travels through the light guide in a direction other than the direction in which the light guide has its smallest dimension. The light guide is arranged such that it is at least partially parallel to the display and / or at least at one point along the light guide, the direction of its smallest dimension is the same as the direction of the smallest dimension of the display. In particular, the shape of the light guide can follow the shape of the display.

[0019] The light guide is specifically designed to transmit light from the side facing away from the display surface and / or the at least one occupant of the vehicle through the display with the switchable layer. This can result in backlighting of the display. The backlighting can have the advantage of increasing the apparent transmittance of the transparent display with the switchable layer, allowing the at least one occupant to perceive, more clearly and / or more brightly, an interior surface located behind the transparent display and the switchable layer, which may be behind the transparent light guide.This is primarily due to the fact that, with the backlight activated, more light passes through the light guide in the display with the switchable layer than when the backlight is deactivated. This allows the background behind the transparent display with the switchable layer to be perceived more clearly. The effect is similar to that of sunglasses, where the lenses appear more transparent in sunlight than in the absence of sunlight. The backlight is particularly useful because the transparent display with the switchable layer has a lower transmittance than a transparent display on its own.

[0020] The arrangement of at least one connection on the circumference of the light guide allows, particularly with a transparent light guide, a view through the display to an interior surface located behind the light guide. This is primarily because, when reading the display, one is not looking directly at the at least one light source. This can make the vehicle interior appear larger, as it is particularly easy to see through the display, especially when the display is not in use and / or is inactive.

[0021] Seeing through the display is particularly good when light from at least one light source is guided through the light guide and / or the switchable layer has the highest possible transmittance.

[0022] The cavity is open on at least one side and / or along at least one edge, in particular on all but one side and / or edge of the display. A side and / or edge of the display may be defined by a border of the display area. The shape of the display may, for example, be based on a rectangle. A cross-section of the cavity may have the same and / or a similar shape to the display in a plane in which the display area lies. In a plane perpendicular to the plane in which the display area lies, the cavity may not be structurally separated from the rest of the vehicle interior, in particular from the air in the rest of the vehicle interior.In general, a cavity that is open on at least one side and / or along at least one edge can mean that the cavity is not structurally separated from the rest of the vehicle interior on at least one side and / or along at least one edge.

[0023] The open cavity allows air to circulate between the cavity and the rest of the vehicle interior. This enables particularly effective heat dissipation from the display and / or light guide, thus protecting them from overheating. Additionally or alternatively, the cavity can be used as a storage space, for example, for a mobile device, especially a smartphone, and / or a notepad and / or wallet.

[0024] The invention also includes further developments that result in additional advantages.

[0025] Further training includes ensuring that the light guide is transparent. In particular, the light guide is permeable to light from all sides.

[0026] In particular, the light guide is transparent in the direction in which it has its smallest dimension and / or in which the transparent display has its smallest dimension. The fact that the light guide is transparent means, in particular, that it transmits at least 70%, more specifically at least 80%, and preferably at least 90% of the incident light.The transparency of the light guide offers the advantage that a background, for example an interior surface on which the light guide is mounted, is visible through the transparent display with the switchable layer and through the light guide, which can, for example, make the vehicle interior appear larger and / or allow information and / or images to be displayed behind the display device and / or create a seamless transition between the display device and the interior of the vehicle in which the display device is mounted.

[0027] One further development involves dividing the switchable layer into several independently controllable areas, particularly strip-shaped areas. This means, in particular, that the transmittance of the display can be adjusted independently in these areas using the switchable layer. This allows some areas of the display to have a higher transmittance than others. Consequently, the display device can have areas on the display surface where it is see-through and areas where it is not, and / or where black and / or dark pixels can be generated. This means, in particular, that areas with varying transmittances can be provided.

[0028] The strip shape is particularly advantageous because it allows a device for controlling the independently controllable areas to be provided on only one side of the display, which is specifically perpendicular to the direction of the stripes. In particular, the control device is a device by which voltage can be applied to the controllable layer, and the controllable layer is a layer whose transmittance changes when a voltage is applied and remains constant when no voltage is applied.

[0029] A further development involves the at least one planar light guide having multiple light guide layers, each with at least one connection for at least one independent light source. This means, in particular, that in the direction of the light guide's smallest dimension and / or in the direction in which the display with the switchable layer is located relative to the light guide, several light guide layers are arranged one above the other and / or next to each other, with each light guide layer potentially being transparent in the direction of its smallest dimension. Each light guide layer has at least one independent connection, enabling each layer to receive light from at least one independent light source. This allows the light emitted by each light guide layer towards the display to be individually adjusted.In particular, the design of the light guide from several light guide layers can ensure that the amounts of light emitted from the respective light guide layers towards the display add up.

[0030] Especially when the different light guide layers have different brightness distributions with which they emit light towards the display, the brightness distribution can be individually adjusted via the display by controlling the individual and / or separate connections of the light guide layers. This is particularly useful when the display is inactive and / or when the display with the switchable layer has the highest possible transmittance. Additionally or alternatively, each light guide layer can be illuminated in a different color by selecting a different light source, thus providing a cost-effective way to choose a color for backlighting the display.

[0031] With adjacent light guide layers, it is advantageously possible to achieve different levels of backlighting in different areas of the display. Backlighting refers specifically to illumination from behind, i.e., light shining onto an object, such as the display, from behind. This is a particularly simple and / or cost-effective way to implement different backlight intensities for different areas of the display.

[0032] A further development involves the planar optical fiber comprising several optical fiber layers. Of these layers, at least one is a diffuser layer designed to radiate the light from at least one light source evenly across its entire exit surface. This means, in particular, that the diffuser layer exhibits a constant brightness distribution across its entire exit surface. The diffuser layer can, for example, be designed as a volume diffuser, which is known from the prior art. A volume diffuser is a transparent component with embedded scattering centers. This means that scattering centers exist within the volume of the diffuser, scattering the light that is located within the diffuser and / or that strikes one of the scattering centers within the diffuser. These scattering centers can, for example, be air inclusions.The diffuser layer is specifically designed as a volume diffuser in which the scattering centers are uniformly distributed within the diffuser layer. A uniform distribution of scattering centers in the diffuser layer can mean that the number of scattering centers differs by a maximum of 10%, particularly a maximum of 5%, when considering any two volume elements of the same size, and / or that the distance between two adjacent scattering centers differs by a maximum of 5% from the average distance between two scattering centers in the diffuser layer. Additionally or alternatively, the diffuser layer can have a microstructure, particularly a uniform microstructure, distributed across its entire exit surface for uniformly coupling the light out of the optical fiber. This microstructure reduces the reflection coefficient at the surface of the optical fiber. The advantage of the diffuser layer is uniform backlighting of the display.

[0033] In addition, at least one of the multiple optical fiber layers has scattering centers in a definable sub-region of the optical fiber layer, such that the optical fiber layer is configured to emit the light from the at least one light source only in that definable sub-region, in particular via the exit surface. Specifically, light is emitted in a radiation area of ​​the exit surface that is an image and / or projection of the definable sub-region onto the exit surface, particularly in the direction where the optical fiber has its smallest extent and / or in the specified direction.This means that the scattering centers are arranged only in the at least one definable sub-region, or in a higher concentration in the at least one definable sub-region, than in the rest of the optical fiber, such that, for example, at least 70%, in particular at least 80%, preferably at least 90% of the emitted light is scattered in the at least one definable sub-region and / or emitted beyond the emission area. Additionally or alternatively, it can be provided that the microstructure is located only within the emission area.

[0034] Additionally or alternatively, at least one mold layer can have a microstructure within the defined emission range of the exit surface, such that the mold layer is configured to emit the light from the at least one light source only within this defined emission range. This means that the light is guided within the mold layer by total internal reflection at at least one inner surface of the mold layer. The inner surface is an inside surface of the optical fiber. If the light strikes an inside surface of the exit surface in an area that lacks a microstructure, a smaller amount of light is coupled out of the optical fiber than if the light strikes the inside surface of the exit surface within the defined emission range.In particular, at least 80%, preferably at least 90%, of the light propagating within the optical fiber is totally reflected when it strikes the inner surface of the exit surface in an area without a microstructure. Thus, more light is coupled out of the optical fiber, especially in areas where the exit surface has a microstructure, than in areas without a microstructure.

[0035] The advantage of this form-based approach is that the light is emitted in the form of a fixed symbol and / or fixed information, and / or the display is backlit with light in the shape of the fixed symbol and / or fixed information. This allows information to be transmitted via the backlighting of the display.

[0036] The advantage of combining at least one diffuser layer and at least one form layer is that either uniform backlighting of the display is possible, allowing the display to appear uniformly transparent, and / or a more transparent form, corresponding to the shape of at least one definable sub-area, can be displayed on the otherwise less transparent display. Information can be conveyed, for example, using this more transparent form.

[0037] As a further solution, the invention comprises a motor vehicle including at least one vehicle display device, wherein a rear surface of the planar light guide opposite the exit surface is mounted on an interior surface, in particular an opaque surface, within the vehicle interior. This means that the vehicle interior has at least one interior surface, for example, a part of the vehicle's dashboard, onto which the planar light guide is mounted with its rear surface. The rear surface of the light guide is, in particular, the surface that has the opposite orientation to the exit surface of the light guide and / or that faces away from the display.This offers the advantage that when looking through the transparent display with the switchable layer and through the light guide, the interior surface is visible, resulting in a seamless transition between the vehicle interior and the display device.

[0038] A further development of the vehicle involves the display being attached only along one side and / or edge, with the remainder of the display floating freely. Specifically, this means that the display is only attached along one side, and the rest of the display stands and / or hangs freely within the vehicle interior. This can result in a cavity open at least on one side and / or edge of the display. The floating portion of the display allows for particularly efficient heat dissipation from at least one component of the display device, such as the display itself, the light guide, and / or the switchable layer. Additionally or alternatively, this can create additional storage space between the transparent display with the switchable layer and the light guide.This storage space can accommodate, for example, a mobile device, especially a smartphone and / or a smartwatch, and / or a notepad and / or a notepad.

[0039] A further development of the vehicle includes the display with the switchable layer having a larger extent in the vehicle's vertical direction than the planar light guide. In particular, it may be provided that a side and / or edge of the display located lower in the vehicle's vertical direction and the light guide are positioned at the same height and / or at the same value in the vehicle's vertical direction. Specifically, it may be provided that only a portion of the display located lower in the vehicle's vertical direction is backlit by the light guide, and a portion of the display located higher in the vehicle's vertical direction is not backlit by the light guide.

[0040] The display with the switchable layer is arranged in the vehicle such that, in a section of the display on the side containing the switchable layer, there is only the switchable layer and, spaced apart from it, a vehicle window separating the vehicle interior from the vehicle exterior. This section of the display is preferably positioned higher in the vehicle's vertical direction than another section of the display that can be backlit by the light guide. This section is characterized in particular by the fact that no light guide is arranged in this section on the side containing the switchable layer, meaning that this section is not backlit. It is possible that, instead of the light guide, a vehicle window is arranged, the distance of which to the display can be smaller or larger than the distance between the display and the light guide in the other, backlit section of the display.

[0041] This further development offers the advantage that, in the area through the display, the switchable layer, and the vehicle windshield, the vehicle's exterior and / or at least a portion of it can be visible, particularly if the switchable layer has a state of maximum transparency and / or if it transmits at least 30%, and especially at least 50%, of the incident light. This allows for an effect similar to a head-up display known from the prior art, with the key difference being that, instead of the vehicle's exterior, the interior surface is visible in the other, backlit area of ​​the display.

[0042] The vehicle window is preferably a windshield and / or front window and / or a side window of the motor vehicle. The vehicle exterior is at least part of the environment surrounding the motor vehicle.

[0043] Further development of a motor vehicle includes the requirement that the vehicle's interior surface incorporates at least one display designed to show the same information when the display is switched off as is displayed on the display when it is in use, particularly when the display is continuously active. This means that information which is permanently displayed on the display when it is active is reproduced by a display in and / or on the interior surface, at least when the display is deactivated and / or inactive. The advantage is that the information is continuously available and / or readable. The display could, for example, be a clock. The information could, for example, be information about the current weather, the time, the date, and / or the quality of a connection to an external device and / or station.

[0044] A further development of the motor vehicle comprises a control device configured to display a first message on the screen and to project a second message onto the interior surface of the vehicle via at least one projector, the entire visible display being a superposition of the second and first messages. This means that the total visible display reproduced by the display device is composed of the first message, displayed by the screen, and the second message, projected onto the interior surface by the projector. This allows for the creation of a three-dimensional effect in the visible display.

[0045] To ensure that the second display is correctly positioned relative to the first, so that the first and second displays work together correctly from the perspective of at least one occupant and / or appear in the correct position relative to each other, it may be possible to determine the position of the occupant's head using at least one interior camera. Additionally or alternatively, if the occupant is the driver of the vehicle, a driver-adjustable display, such as a head-up display, may be used to determine the driver's head position.

[0046] The visible display, composed of a first display and a second display, can be used, for example, when information is to be displayed against a background with other information, such as the current location in front of a map during navigation.

[0047] The invention also includes further developments of the motor vehicle according to the invention, which have features already described in connection with the further developments of the motor vehicle display device according to the invention. For this reason, the corresponding further developments of the motor vehicle according to the invention are not described again here.

[0048] As a further solution, the invention comprises a method for operating the motor vehicle display device with at least one light source and / or a method for operating a vehicle with a motor vehicle display device and preferably at least one light source. The method comprises displaying an output on the display surface of the transparent display, for which purpose a switchable layer is applied to the surface of the transparent display opposite the display surface, by which, at a set first transmittance level, a darkening of at least parts of the display surface is achieved.With a second transmittance of the switchable layer set higher than the first, light is emitted via a planar light guide located on the side of the switchable layer and spaced apart from it, increasing the transmittance of light through the vehicle display device and / or the display with the switchable layer and / or increasing the apparent transparency of the vehicle display device and / or the display with the switchable layer. This means that the transmittance of the switchable layer can be changed and / or adjusted, achieving different effects depending on the set transmittance.At the first transmittance level, where a smaller percentage of the light incident on the switchable layer is transmitted through it, a darker area can be provided behind the transparent display compared to the second transmittance level. This allows, in particular, the creation and / or display of darker pixels. At the second transmittance level, however, apparent transparency of the display and / or the display device can be achieved; that is, an interior area behind the display device and / or an area behind the transparent display with the switchable layer can be seen more clearly and / or perceived in greater detail.

[0049] A further development of the method involves emitting light from a light source via the planar light guide and / or ensuring that at least one area of ​​the switchable layer exhibits the second transmittance when nothing is displayed on the screen and / or when only part of the screen displays something and / or when at least part of the screen displays something that does not require a dark and / or black background for display. This allows for apparent transparency of the display, at least in those cases and / or areas where a background, particularly the interior surface and / or part of the vehicle exterior, is intended to be visible and / or where a dark and / or black background is not required to display information with dark and / or black pixels.

[0050] For use cases or application situations that may arise during the procedure and are not explicitly described here, it may be provided that, according to the procedure, an error message and / or a request for user feedback is issued and / or a default setting and / or a predetermined initial state is set.

[0051] The invention also includes further developments of the method according to the invention, which have features already described in connection with the further developments of the motor vehicle and / or the motor vehicle display device according to the invention. For this reason, the corresponding further developments of the method according to the invention are not described again here.

[0052] As a further solution, the invention also includes a computer-readable storage medium comprising program code which, when executed by a computer or a computer network, causes it to execute an embodiment of the method according to the invention. The storage medium can be provided at least partially as a non-volatile data storage medium (e.g., as flash memory and / or as an SSD - solid state drive) and / or at least partially as a volatile data storage medium (e.g., as RAM - random access memory). The storage medium can be located within the computer or computer network. However, the storage medium can also be operated, for example, as an app store server and / or cloud server on the internet. The computer or computer network can provide a processor circuit with, for example, at least one microprocessor.The program code can be provided as binary code, assembly code, source code in a programming language (e.g., C), or a program script (e.g., Python). Alternatively, the computer-readable storage medium can be implemented as a signal containing computer-readable data, such as a time-varying voltage signal or a radio signal.

[0053] The invention also includes the control device for the vehicle display device. The control device can comprise a data processing device or a processor circuit configured to perform an embodiment of the method according to the invention. For this purpose, the processor circuit can comprise 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). In particular, a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), or an NPU (Neural Processing Unit) can be used as the microprocessor. Furthermore, the processor circuit can comprise program code configured to perform the embodiment of the method according to the invention when executed by the processor circuit.The program code can be stored in a data memory of the processor device. The processor device can be based, for example, on at least one circuit board and / or on at least one SoC (System on Chip).

[0054] The invention also includes combinations of the features of the described embodiments. The invention therefore also includes realizations that each exhibit a combination of the features of several of the described embodiments, provided that the embodiments have not been described as mutually exclusive.

[0055] The following are exemplary embodiments of the invention described. This is illustrated by: Fig. 1 a schematic cross-section of an embodiment of a motor vehicle display device according to the invention; Fig. 2 a schematic cross-section of an embodiment of a motor vehicle display device according to the invention; Fig. 3 a schematic representation of an embodiment of a motor vehicle display device according to the invention.

[0056] The exemplary embodiments described below are preferred embodiments of the invention. In these exemplary embodiments, the described components each represent individual features of the invention, which can be considered independently of one another and each further develops the invention independently. Therefore, the disclosure is intended to include combinations of features of the embodiments other than those shown. Furthermore, the described embodiments can also be supplemented by further features of the invention already described.

[0057] In the figures, identical reference symbols denote functionally equivalent elements.

[0058] Fig. Figure 1 shows an exemplary embodiment of the motor vehicle display device 10. The motor vehicle display device 10, hereinafter also referred to as display device 10, comprises a transparent display 12, also referred to as display 12, which includes a display area 14. The display area 14 can be the area of ​​the display 12 that faces an occupant 16 of a vehicle, represented by the eye, when the display device 10 is integrated into a vehicle. In particular, the display area 14 is an area that is perpendicular to a distinguished direction 18, wherein the distinguished direction 18 is the direction in which the display 12 has the smallest extent. Content and / or information can be displayed on the display area 14, which can be perceived, for example, by the at least one occupant 16.

[0059] On a surface opposite the display area 14, for example on a rear surface 20 of the display 12 facing the display area 14, a switchable layer 22 is provided, the transmittance of which can be changed and / or adjusted. This means that it is possible to adjust how much of the light arriving at the switchable layer 22 is transmitted through the switchable layer 22 and forwarded to the display 12. To change its transmittance, the switchable layer 22 can, for example, have a control device that applies a predefined voltage for a predefined duration upon receiving a predefined signal.

[0060] The switchable layer 22 can be shown, as exemplified and schematically in Fig. Figure 3 shows that the display can be divided into several independently controllable areas 222, which can be set independently of each other. This allows different transmission levels to be assigned to different areas of the display 12 with the switchable layer 22, corresponding to the independently controllable areas 222 of the switchable layer 22.

[0061] A light guide 26 is arranged on the side of the display 12, on which the switchable layer 22 is located, and is spaced apart by a cavity 24. The light guide 26 includes at least one terminal 28 (two terminals are shown by way of example in the present example), which is configured to be connected to at least one light source. Light from at least one light source can be introduced into the light guide 26 via the at least one terminal 28.

[0062] The optical fiber 26 can be designed as a volume diffuser, i.e., it can have several scattering centers within a transparent volume at which the light propagating within the volume can be scattered. The scattering of the light at these scattering centers can change the direction of propagation, causing the light to exit the optical fiber 26.

[0063] The optical fiber 26 can be designed such that the scattering centers are distributed throughout the entire optical fiber 26, particularly uniformly, resulting in uniform light emission. This means, in particular, that the amount of light exiting the optical fiber 26 per unit time is the same at every point of an exit surface 30, which corresponds to a surface of the optical fiber 26 facing the display 12, preferably within a predefinable error interval. Thus, the display 12 is uniformly backlit.

[0064] Additionally or alternatively, it can be provided that scattering centers are present only in a definable sub-area of ​​the optical fiber 26 and / or that the number of scattering centers in the definable sub-area is greater than in the rest of the optical fiber 26. This means that more light propagating in the optical fiber 26 is scattered in the definable sub-area, resulting in more light exiting the optical fiber 26 within a definable emission area than on the rest of the emission surface 30. The definable emission area can be a projection of the definable sub-area onto the emission surface 30.

[0065] The effect of more light exiting the optical fiber 26 within a definable emission zone than on the remaining emission surface 30 can be achieved additionally or alternatively by means of a microstructure present in the definable emission zones on the emission surface 30 of the optical fiber 26. The microstructure is designed to increase the probability of light exiting the optical fiber 26.

[0066] The optical fiber 26 can, as exemplified in Fig. Figure 2 shows several light guide layers 261, 262, at least one of which emits light from light guide layer 161 evenly distributed over the exit surface 30. This at least one light guide layer 161 can be called a diffuser layer. Additionally or alternatively, at least one other light guide layer 162, which can be called a shape layer, emits a greater amount of light per unit area over a definable emission range than over the remaining exit surface 30.

[0067] Each of the optical fiber layers 261, 262 can, for example for separate control, have at least one separate connection 28 for connecting the at least one light source.

[0068] As an alternative to the multiple optical fiber layers 261, 262, the optical fiber 26 can comprise only one optical fiber layer 261, 262, as exemplified in Fig. 1 is shown.

[0069] The at least one connection 28 for connecting the at least one light source is arranged on the circumference of the light guide 26. This means, in particular, that the at least one connection 28 is attached to a side of the light guide 26 and / or the light guide layer 261, 262 that is different from the exit surface 30 of the light guide 26 and a rear surface 32 of the light guide 26 opposite the exit surface 30.

[0070] In particular, it may be provided that the light source is not attached to the rear surface 32 of the light guide 26, so that, in the case of a light guide 26 that is transparent, particularly in the distinguished direction 18, an interior surface 34 can be seen through the light guide 26, in particular through the display 12, the switchable layer 22 and the light guide 26, for example by the occupant 16 of the vehicle. The interior surface 34 may be a surface, particularly in a vehicle interior, on which the light guide 26 is attached.

[0071] Between the light guide 26 and the display 12 with the switchable layer 22 is the cavity 24. The cavity 24 can have at least one opening 36, so that, in particular, an exchange of air between the cavity 24 and the air outside the cavity 24 can take place. For the cavity 24 to have the opening 36, the cavity 24 can be open along at least one edge and / or side 38, 381, 382, ​​383 of the display 12.

[0072] For example, the opening 36 of the cavity 24 in Fig. 1 and Fig. Figure 2 shows that the cavity 24 is open at least along the upper edge and / or side 38, 381 of the display 12. Fig. 3 the cavity is additionally open at least along the side edges and / or sides 38, 382, ​​383 of the display 12.

[0073] The opening 36 of the cavity 24 can be realized by structurally separating the display 12 along at least one edge and / or side 38, 381, 382, ​​383 from other elements and / or components, in particular all other elements and / or components, of the vehicle interior in which the display device 10 is mounted and / or which comprises the display device 10. In particular, it can be provided that the display 12 is only attached along one side and / or edge 40 and the rest of the display 12 is freestanding, as shown in the figures, in particular in Fig. 3 (since it is a matter of Fig. 1 and Fig. 2 each represents a cross-section through the display device 10), is shown.

[0074] As in Fig. As exemplified in Figure 2, it can be provided that in a motor vehicle comprising at least one display device 10, the extension of the light guide 26 in the vehicle's vertical direction 42 is less than the extension of the display 12 with the switchable layer 22 in the vehicle's vertical direction 42. This allows the display 12 to be divided into two areas 441, 442 (in Fig. Figure 2 shows an example of a division into the upper area 441 and the lower area 442): firstly, into an upper area 441, which is exemplified by Fig. 2 is located in the vehicle's upward direction above the lower area 442 and in which no backlighting occurs, and in a lower area 442, which is exemplified by Fig.2 is located in the vehicle's vertical direction below the upper area 441 and is backlit. In particular, the lower area 442 connects to a lower display end defined by a lower side and / or edge 40 and / or the upper area 441 connects to an upper display end defined by an upper side and / or edge 38, 381 of the display 12.

[0075] The lower region 442 can be characterized by the fact that, in the distinguished direction on the side of the display 12 where the switchable layer 22 is located, the light guide 26 is arranged over the entire lower region 442. This means that, starting from any point on the display 12 within the lower region 442, a straight line running parallel to the distinguished direction 18 intersects the light guide 26 after the cavity 24. Thus, backlighting of the lower region 442 is possible.

[0076] The upper region 441 is characterized by the fact that, on the side of the switchable layer 22 of the display 12, only a vehicle window 46 is arranged at a distance from the switchable layer; that is, there is no light guide 26. This means that, starting from any point of the display 12 within the lower region 442, a straight line running parallel to the distinguished direction 18 intersects the switchable layer 22 and then the vehicle window 46 on the side of the switchable layer 22 of the display 12. A gap 48 may be located between the switchable layer 22 and the vehicle window 46. This allows the upper region 441 of the display 12 to be viewed from the distinguished direction 18, particularly if the transmittance of the display 12 and the switchable layer 22 is sufficient, through the vehicle window 46.

[0077] It may be provided that, in addition to or as an alternative to the display of information on the display 12, identical and / or supplementary and / or additional information is displayed on the interior surface 34. For this purpose, the display device 10 may include at least one projector which projects the identical and / or supplementary and / or additional information onto the interior surface 34. Additionally or as an alternative, it may be provided that the interior surface 34 includes at least one display on which, when the display 12 is deactivated, information is shown that is permanently displayed on the display 12, so that this information is available regardless of the state of the display 12.

[0078] The following is a particularly preferred embodiment: A light guide in the form of a transparent film, designed for use as a backlight for displays, is known from the prior art. The light guide can have a maximum thickness of 2 mm, particularly 1 mm. Within the light guide, the light can be guided by total internal reflection, with the light being fed into the light guide via at least one connection, particularly at an edge of the light guide. A microstructure on a surface and / or exit surface of the light guide allows for the targeted extraction of light from the light guide.

[0079] It can be provided that the targeted extraction of light from the optical fiber only occurs in predefined emission areas, which are sub-areas of the optical fiber's exit surface. This allows at least one illuminated symbol and / or at least one illuminated graphic and / or at least one illuminated structure to be displayed.

[0080] In the switched-off state, the optical fiber can be transparent, transmitting at least 80%, preferably 90%, of the incident light. The at least one illuminated symbol and / or the at least one illuminated graphic and / or the at least one illuminated structure can be invisible in the state where no light is transmitted through the optical fiber.

[0081] The light guide can be attached to and / or laminated onto an interior surface (application) located behind a transparent display. A gap, formed in particular by a cavity, exists between the light guide and the transparent display. This gap can range from 5 cm to 30 cm.

[0082] Transparent displays, as known from the prior art, are not completely transparent, particularly when a switchable layer is applied, allowing the transmittance of the display to be adjusted. This switchable layer can be a PDLC layer, as known from the prior art. The switchable layer can be adjustable between opaque and partially transparent. The switchable layer may be necessary to create a black background, since transparent displays cannot produce high contrast.

[0083] The light guide can have several light guide layers, for example, a light guide layer for area illumination and / or backlighting of the display and / or a light guide layer for displaying at least one symbol and / or at least one graphic and / or at least one structure.

[0084] The light guide located behind the display allows the interior surface to be illuminated, making it visible through the transparent display with the switchable layer.

[0085] The advantage of this display device is its ability to illuminate the display over a large area and / or homogeneously and / or subtly and / or in a way that enhances the impression of transparency. Additionally or alternatively, the interior surface is more visible, allowing the display to be better integrated into the interior and / or vehicle interior. Additionally or alternatively, the display does not appear out of place. Additionally or alternatively, when the display is switched off, instead of a black surface as with other displays known from the prior art, the interior surface behind the display is visible. This can make the vehicle interior and / or the interior appear wider and lighter. Additionally or alternatively, the light guide is transparent when switched off, allowing the underlying material, particularly the interior surface, to be seen. Additionally or alternatively, the illumination can be switched on and off as desired.

[0086] Overall, the examples show how a luminous film and / or a light guide can be provided on an application and / or interior surface behind a transparent display to increase the impression of transparency of the display.

Claims

[1] Motor vehicle display device (10) for an interior of a motor vehicle comprising a planar transparent display (12) with a display area (14), wherein a switchable layer (22) is applied to a surface of the display (12) opposite the display area (14), the transmittance of which is variable, wherein a planar light guide (26) is arranged on the side of the switchable layer (22) spaced apart from the switchable layer (22) by a cavity (24), wherein the planar light guide (26) is configured to emit light from at least one light source via an exit surface (30) in the direction of the transparent display (12), wherein the planar light guide (26) comprises at least one connection (28) for at least one light source, wherein the at least one connection (28) is attached to the circumference of the planar light guide (26), characterized by , that the cavity (24) is open on at least one side and / or along at least one edge (38) of the display (12). [2] Motor vehicle display device (10) according to claim 1, wherein the cavity (24) is open on all but one side and / or edge (38) of the display (12). [3] Motor vehicle display device (10) according to one of the preceding claims, wherein the light guide (26) is transparent. [4] Motor vehicle display device (10) according to one of the preceding claims, wherein the switchable layer (22) is divided into several independently controllable areas (222), in particular strip-shaped areas. [5] Motor vehicle display device (10) according to one of the preceding claims, wherein the at least one planar light guide (26) has several light guide layers (261, 262) each comprising at least one separate connection (28) for at least one separate light source. [6] Motor vehicle display device (10) according to claim 5, wherein of the several light guide layers (261, 262) at least one diffuser layer is configured to emit the light of the at least one light source uniformly distributed over the entire exit surface (30) and at least one shaped layer has scattering centers in at least one definable sub-area of ​​the shaped layer and / or has a microstructure in a definable emission area of ​​the exit surface (30) such that the shaped layer is configured to emit the light of the at least one light source only in the at least one definable sub-area and / or in the definable emission area. [7] Motor vehicle comprising at least one motor vehicle display device (10) according to one of the preceding claims, wherein a rear side (32) of the planar light guide (26) opposite the exit surface (30) is mounted on an interior surface (34), in particular an opaque one, in a vehicle interior of the motor vehicle. [8] Motor vehicle according to claim 7, wherein the display (12) is attached only along one side and / or one edge (40) and the rest of the display (12) is free-floating. [9] Motor vehicle according to claim 7 or 8, wherein the display (12) with the switchable layer (22) has a larger extent in a vehicle vertical direction (42) than the planar light guide (26) and wherein the display (12) with the switchable layer (22) is arranged in the vehicle such that in a partial area (441) of the display (12) on the side of the switchable layer (22) there is only the switchable layer (22) and spaced apart therefrom a vehicle window (46) which separates the vehicle interior from a vehicle exterior. [10] Motor vehicle according to one of claims 7 to 9, wherein the interior surface (34) of the motor vehicle comprises at least one display which is configured to display, when the display (12) is switched off, the same information as is displayed on the display (12) when the display (12) is in use, in particular continuously. [11] Motor vehicle according to one of claims 7 to 10, wherein a control device of the motor vehicle is configured to display a first display on the display (12) and to project a second display onto the interior surface (34) of the motor vehicle via at least one projector, wherein an entire visible display is a superposition of the second display with the first display. [12] Method for operating a motor vehicle display device (10) according to any one of claims 1 to 6 with at least one light source and / or for operating a vehicle with a motor vehicle display device (10) according to any one of claims 7 to 11, wherein an output is displayed on the display surface (14) of the transparent display (12), for which purpose the switchable layer (22) is provided on the surface of the transparent display (12) opposite the display surface (14), by which, at a set first transmittance, a darkening of at least parts of the display surface (14) is achieved, and With a set second transmittance of the switchable layer (22) that is greater than the first transmittance, the transmittance of light through the motor vehicle display device (10) and / or the display (12) with the switchable layer (22) is increased by emitting light via a planar light guide (26) arranged from the display (12) on the side of the switchable layer (22) and spaced apart from the switchable layer (22). [13] Method according to claim 12, wherein light from a light source is emitted via the planar light guide (26) and / or at least an area of ​​the switchable layer (22) has the second transmittance when nothing is displayed on the display (12) and / or something is displayed only on part of the display (12) and / or something is displayed on at least part of the display (12) that does not require a dark and / or black background for display.

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