MOTOR VEHICLE WITH A DISPLAY DEVICE AND METHOD FOR ACTIVATING A PRIVACY SCREEN DEVICE

Description

[0001] The invention relates to a motor vehicle with a display device and a method for activating a privacy screen.

[0002] Screens with privacy protection devices, such as a shutter film or an electronically switchable filter, which only allow viewing from a perpendicular angle and block side views, are well-known. This means the image content is either not visible or significantly darkened when viewed from the side. Various technologies exist that can implement this effect in a switchable manner.

[0003] For example, DE 10 2007 001 142 A1 discloses a display device for a vehicle that has a display LCD and a control LCD. The control LCD has transmission switching sections, each with three segment units. When the vehicle is in motion, the left two-thirds of the segment units of each transmission switching section in a section of the control LCD corresponding to the left half of the display LCD's screen are set to an opaque state. In a section of the control LCD corresponding to the right half of the display LCD's screen, all segment units are set to a transparent state. Consequently, an image in the right half of the screen is visible from the driver's seat, while an image in the left half of the screen is invisible from the driver's seat. Both images in the right and left halves of the screen are visible from a passenger's seat.

[0004] From US patent 2021 / 0063783 A1, an electronic apparatus for controlling a passenger seat display in front of a passenger sitting in a passenger seat and a method for controlling the passenger seat display are known.

[0005] From DE 10 2018 111 344 A1, a multifunction device for a vehicle is known. The multifunction device comprises at least one display device and at least one functional element, wherein the functional element is arranged at least partially with respect to a display direction of the display device such that the functional element covers the display device at least partially, at least in a first operation of the display device along a normal direction of the display device, as well as a dashboard with such a multifunction device.

[0006] From US patent 2020 / 0319512 A1, a display with locally dimmable backlighting and an active privacy mode is known. The display can include a backlight source, lenses, a passive diffuser, an active diffuser, and a translucent display. The backlight source can have a two-dimensional matrix of light sources configured to produce an output light. The lenses can be located adjacent to the backlight, aligned with the backlight, and arranged to produce collimated light. The passive diffuser can be located adjacent to the lenses and configured to spatially disperse the collimated light. The active diffuser can be located adjacent to the passive diffuser and configured to generate an intermediate light from the collimated light and to change a diffusion property of the intermediate light in response to a scattering signal.The translucent display can be placed adjacent to the active diffuser and configured to produce multiple visible images by modulating the intermediate light.

[0007] A switchable backlighting system with privacy shield is known from US patent 2020 / 0249504 A1. The backlighting system comprises a first backlighting unit that emits light from a non-viewing side of the backlighting system toward a viewing side of the backlighting system; a second backlighting unit located on a viewing side of the first backlighting unit and emitting light toward the viewing side of the backlighting system; and privacy shielding optics comprising a liquid crystal material and located on a non-viewing side of the second backlighting unit and between the first and second backlighting units, wherein the privacy shielding optics operate such that they transmit light from the first backlighting unit within a limited viewing angle range.

[0008] From FR 3 016 722 A3, a motor vehicle with a display screen incorporating an electronic privacy filter is known. The motor vehicle has a dashboard equipped with a display screen in front of which a passenger seat is located. The display screen includes a filter capable of altering the field of view of the display screen when switching between an inactive state, in which the field of view is open at a wide angle that includes a leading position, and an active state, in which the field of view is closed at a restricted angle that excludes the leading position.

[0009] From DE 10 2013 213 600 A1 a method for controlling an information display in a vehicle is known, in which information is displayed by means of a display device and the light transmission of a disc, which is arranged in a viewing direction from a position in the interior of the vehicle to the display device in front of the display device, is controlled depending on a driving condition of the vehicle.

[0010] A disadvantage of known display devices is that the area to be blocked for the "privacy mode" is always fixed, especially across an entire screen, and thus the entire screen is always darkened for the driver.

[0011] The invention is based on the objective of providing a motor vehicle with an improved display device.

[0012] This problem is solved by the independent patent claims. Advantageous embodiments of the invention are disclosed in the dependent patent claims, the following description, and the figures.

[0013] The invention is based on the understanding that only those displays on a screen of a display device should be hidden from the driver that distract him from driving. To avoid unnecessarily restricting the screen, it is provided that the areas of the screen can be controlled in segments, allowing the driver to activate or deactivate them.

[0014] The invention provides a motor vehicle with a display device arranged on the dashboard of the motor vehicle, wherein the display device has a liquid crystal display assigned to at least one passenger position, wherein the liquid crystal display is divided into a plurality of segments, each segment having an electronically switchable privacy screen configured to block the display of an image of the respective segments from the driver's position and to allow the display from the passenger's position in an activated state, and to allow the display from both positions in a deactivated state, wherein the display device is configured to determine the segments on which a moving entertainment display is shown and to activate the privacy screen for these segments.

[0015] In other words, the motor vehicle includes a display device featuring a liquid crystal display (LCD). The LCD typically comprises a backlight that generates diffuse light and a liquid crystal display layer that can activate or deactivate individual pixels for a display by means of light polarization control. The display device with the LCD is preferably located in the passenger position, meaning that the LCD is positioned substantially in front of the passenger. For example, at least 60 percent of the screen surface may be located directly in front of the passenger.

[0016] Preferably, the liquid crystal display can be divided into several segments, where "segments" can refer to electronically controllable areas of the liquid crystal display. Each of these segments can include an electronically switchable privacy screen that blocks the display from the driver's line of sight. This means that when the privacy screen is activated, the driver can only see a dimmed image or no image at all in the respective segment. This can be achieved, in particular, by controlling the direction of the light from the liquid crystal display. The privacy screen is preferably electronically switchable, meaning that it can be activated and deactivated. Thus, even when the privacy screen is deactivated, an image can still be perceived from the driver's line of sight.

[0017] Since not all display images should be hidden for the driver of the vehicle, the display device is designed to detect which segments are showing an animated entertainment display. An entertainment display, for example, refers to a film or a game that can be displayed on the display for a passenger. Animated entertainment displays, in particular, can endanger road safety, as they can distract the driver from the road.

[0018] Preferably, the entire liquid crystal display is divided into segments. This means that not only individual areas of the liquid crystal display have the segments. For example, each pixel of the liquid crystal display can be controlled by the privacy screen. Furthermore, the liquid crystal display can preferably extend across the entire dashboard.

[0019] The privacy screen can preferably be provided by means of a switchable collimator that can parallelize the light from the liquid crystal display and thus only emit a display from a predetermined direction. For this purpose, for example, arrangements of several layers of liquid crystals can be provided, or the backlight of the liquid crystal display can be designed in such a way that it emits parallelized light.

[0020] The invention offers the advantage that the entire liquid crystal display does not need to be switched off for the driver, and all static content, such as status bars, controls, the time, information, and / or navigation displays, can be seen by both the passenger and the driver. This preserves the overall visual appearance of the display device and avoids large black areas. Furthermore, safety is increased because no moving entertainment displays are shown to the driver.

[0021] Furthermore, according to the invention, the liquid crystal display (LCD) has, in addition to an LCD display layer, at least one LCD cell layer, designed as a twisted nematic (TN) cell layer, as a privacy screen. This LCD cell layer is segmentally controllable and is designed to collimate light beams in the direction of view of the passenger when a voltage is applied. In other words, the LCD can have an LCD display layer that serves to control the image of the LCD. The LCD display layer is prior art and is included in every LCD. In addition to this LCD display layer, the LCD has an LCD cell layer as a privacy screen, which can be constructed according to the same principle as the LCD display layer.In particular, this additional liquid crystal layer can be a TN (twisted nematic) cell layer. Here, two polarizing filters, offset by 90 degrees in their polarization direction, can enclose a layer of liquid crystal molecules. The liquid crystal molecules can rotate the polarization direction of the light depending on a voltage applied to them. Thus, the transmission of light from both polarizers can be controlled.

[0022] An additional effect of the liquid crystal cell layer is that, depending on the applied voltage, the direction of light emission passing through the liquid crystal cell layer can be controlled. This means that, in a conventional LCD screen, rays at the edges are attenuated compared to perpendicular rays, and this effect can be further enhanced by arranging additional liquid crystal cell layers. Thus, an asymmetry can be created so that rays directed towards the driver's position are minimized.

[0023] According to the invention, the privacy function is achieved by switching the liquid crystal cell layer in such a way that a lattice-like structure is created within it. In other words, the liquid crystal cell layer, which is designed as a TN cell layer, is an opaque layer with individual transparent holes within it. Only parallel rays pass through these holes, while lateral rays are largely filtered out. This offers the advantage that mainly perpendicular rays are generated, and lateral rays, particularly those in the driver's line of sight, are blocked.

[0024] The invention also includes embodiments that offer additional advantages.

[0025] In one embodiment, the at least one liquid crystal cell layer is arranged between a backlight of the liquid crystal display and the liquid crystal display layer of the liquid crystal display, or on a surface of the liquid crystal display. This arrangement allows for particularly advantageous directional control of the light.

[0026] It is particularly preferred that several liquid crystal cell layers arranged one behind the other and aligned with each other are provided as a privacy screen. Preferably, two or three of these liquid crystal cell layers can be arranged one behind the other, so that the peripheral rays in the driver's line of sight are filtered out by at least 90 percent, preferably at least 95 percent. This embodiment offers the advantage of providing an electrically controllable and space-saving privacy screen that can be controlled segment by segment.

[0027] In an unclaimed alternative, the backlight of the liquid crystal display for providing the privacy screen is designed as a two-layer system, wherein a first backlight layer is configured to emit light diffusely, and a second backlight layer is configured to emit light collimated in the direction of view of the passenger. The two backlight layers are configured to illuminate the respective segments separately, and in the activated state of the privacy screen, only the second backlight layer emits light in the respective segment, while the first backlight layer is deactivated in that segment. In a deactivated state of the privacy screen, preferably only the first backlight layer emits light, and the second backlight layer is deactivated.This means that the liquid crystal display's backlight can emit at least two types of light by providing two backlight layers.

[0028] The first backlight layer emits diffuse light, as is typical for a standard LCD screen. For this purpose, LEDs, for example, can be used as the backlight layer. The second backlight layer can emit light collimated in the direction of view from the passenger's position. This means that essentially parallel light is emitted in the direction of the passenger's position. Consequently, little or no light from the second backlight layer is emitted towards the driver's position, which can obstruct the display for the driver. The respective backlight layers are preferably designed to illuminate the individual segments of the liquid crystal display separately and alternately. This means that in a segment where the first backlight layer is activated, the second backlight layer is deactivated, and vice versa.This allows the privacy screen to be activated for each segment by emitting light only from the second backlight layer for that segment.

[0029] Preferably, the second backlight layer includes at least one collimator device. This means that at least one collimator device can be provided to deliver a predetermined direction of light. For example, a light source, particularly an LED, can be provided as the collimator device at a focal point or focal plane of a converging lens, thereby aligning the light rays. Additionally or alternatively, a pinhole aperture or a grating can be provided, which can also define the direction of the light. Light guidance via microprisms or other optical structures can also be provided as the collimator device. Preferably, the collimator device can include a condenser that collects light rays and delivers them to the collimator device to increase the intensity of the light signal.This design offers the advantage that light can be directed directly at the backlight, resulting in a higher light intensity for the privacy screen.

[0030] In a further embodiment, the segments are designed as horizontal and / or vertical strips. In other words, the segments can extend from one side of the screen to the other, overlapping and / or side by side to cover the entire screen area. This embodiment offers the advantage that the control unit for the segments, and thus the privacy screen mechanism, can be housed in an edge of the screen, thereby simplifying the control of the privacy screen.

[0031] In a further advantageous embodiment, the segments are designed as rectangles and / or rhombuses. This means that individual rectangular areas within the screen can be controlled, and these areas do not have to be located at the edge but can be arranged within the screen. Preferably, each pixel of the liquid crystal display can represent a rectangular segment. This allows for particularly precise control, especially for each pixel, of whether it should be visible from the driver's position or not.

[0032] Another embodiment provides that the display device is configured to determine whether the vehicle is moving or stationary and / or whether it is being operated manually or autonomously, and to activate the privacy screen if the vehicle is moving and / or being operated manually, and to deactivate the privacy screen if the vehicle is stationary and / or being operated autonomously. In other words, the display device can check and distinguish whether the vehicle is moving or stationary and / or whether it is being operated manually or autonomously. Since the privacy screen is preferably intended to increase driving safety for the driver, it can then be activated if the vehicle is moving and the driver is operating it manually.When the vehicle is stationary, the privacy screen for the moving entertainment displays can be enabled. Even during autonomous driving, the moving entertainment displays can be enabled by the privacy screen, allowing the driver and a passenger to watch a moving entertainment display, such as a film, together. This design offers the advantage of improved safety.

[0033] Another aspect of the invention relates to a method for activating a privacy screen with a motor vehicle according to one of the preceding embodiments. The method comprises the following steps: determining whether the motor vehicle is being driven in manual mode, determining the segments of the display device on which a moving entertainment display is shown, and activating the privacy screen in the segments where the moving entertainment display is shown if the motor vehicle is being driven in manual mode. This offers the same advantages and possibilities for variation as with the motor vehicle.

[0034] The invention also includes the control device for the motor vehicle. The control device can comprise a data processing device or a processor unit configured to carry out an embodiment of the method according to the invention. For this purpose, the processor unit 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). Furthermore, the processor unit can comprise program code configured to carry out the embodiment of the method according to the invention when executed by the processor unit. The program code can be stored in a data memory of the processor unit.

[0035] 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 according to the invention. For this reason, the corresponding further developments of the method according to the invention are not described again here.

[0036] 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.

[0037] 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.

[0038] The following are exemplary embodiments of the invention described. This is illustrated by: Fig. 1 a perspective view of a motor vehicle interior with a display device according to an exemplary embodiment; Fig. 2 a schematic representation of a display device according to an exemplary embodiment; Fig. 3 a schematic process diagram according to an exemplary embodiment.

[0039] 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.

[0040] In the figures, identical reference symbols denote functionally equivalent elements.

[0041] In Fig. 1 Figure 1 shows a perspective view of the dashboard of a motor vehicle 10 with a display device 12 according to an exemplary embodiment. The display device 12 can be arranged on the dashboard of the motor vehicle 10, preferably being designed as a liquid crystal display covering a large part of the dashboard. Preferably, however, the display device 12 can be substantially located in front of the passenger position 14. This means that more than 70 percent of the area of ​​the liquid crystal display is located in front of the passenger position 14.

[0042] A disadvantage of such a large display device 12 is that a driver in a driving position 16 can be distracted by the display of the device 12, which could endanger the road safety of the motor vehicle 10. In particular, moving entertainment displays, such as films, can be highly distracting and are prohibited in many countries while driving.

[0043] To prevent such distraction while still allowing a passenger to view a moving entertainment display, the liquid crystal display can be divided into several segments 18, each of which has a switchable privacy screen 20. The privacy screen 20 can preferably be configured to assume at least two states. In a deactivated state, the display can be seen from both the driver's position 16 and the passenger's position 14, while in an activated state, the privacy screen 20 can only be seen from the passenger's viewing position 14. This means that light rays towards the driver's position 16 can be blocked when the privacy screen 20 is activated.

[0044] This will be explained below using an example. A passenger in passenger seat 14, for instance, wants to play a film on the display device 12, but does not need the entire surface of the liquid crystal display. In particular, the window size for displaying the film can be adjusted variably, so that, for example, the film is displayed in section 22.

[0045] Section 22 of the liquid crystal display is shown here in a further schematic view for explanation, whereby the entire liquid crystal display can be constructed in the same way. The liquid crystal display can have at least a backlight 24 and a liquid crystal display layer 26. The backlight 24 and the liquid crystal display layer 26 are common components for a liquid crystal display. The backlight 24 can be configured to generate a diffuse light signal, and the liquid crystal display layer controls the transmittance of the individual pixels to this light in order to generate an image.

[0046] The privacy screen 20 can be arranged between the backlight 24 and the liquid crystal display layer 26. In this embodiment, the privacy screen 20 can be designed as an additional liquid crystal cell layer, in particular as a twisted nematic cell layer (TN cell layer). This TN cell layer 20 can be divided into several segments 18, which can be controlled separately to block the view from the driver's position 16. In particular, the effect of liquid crystal cell layers or liquid crystal molecules can be utilized, namely that the polarization and direction of the light is adjusted depending on the applied voltage. When the light passes through the liquid crystal cell layers, one or more directions of the light are attenuated. By appropriately controlling the liquid molecules with a voltage value, light in the direction of the driver's view can thus be attenuated.Preferably, several liquid crystal cell layers 20 can be arranged one behind the other and aligned in such a way that the light in the direction of the driver's position 16 is reduced to an intensity of less than 1 percent at a predetermined applied voltage.

[0047] Preferably, the entire liquid crystal display of the display device 12 can be configured as described above, such that, depending on the size of the cutout 22, the display of this cutout 22 can be blocked for the driver. Particularly preferably, the display device 12 can be configured to determine those segments 18 that constitute the cutout 22 of the liquid crystal display and that show the animated entertainment display, in order to automatically block this display for the driver. In particular, even after adjusting the size of the cutout 22, the privacy screen 20 can be variably controlled so that only the animated entertainment display is blocked and the rest of the display device remains visible to the driver.

[0048] In Fig. 2 A further exemplary alternative for implementing the privacy screen 20 is shown. In this embodiment, the display device 12 can have a two-layer backlight, in front of which the liquid crystal display layer 26 is arranged. A first backlight layer 24 can be configured, like a normal backlight of a liquid crystal display, to emit light diffusely. That is, the light from the first backlight layer can be emitted in all directions. A second backlight layer 28 can be configured to emit light collimated in the direction of view of the passenger position 14.To collimate the light from the second backlighting layer 28, a collimator device (not shown) can be provided, which, for example, has a pinhole aperture downstream of a light source and additionally a converging lens whose focal point lies in the aperture hole. Preferably, an LCF (Light Control Film) can also be used as a collimator device. Thus, light rays from the light source can be aligned parallel and directed in a predetermined direction.

[0049] To change the state for a given segment 18 using this embodiment, it can be provided that in the areas to be seen from the driver's position 16, only the first backlight layer 24 is activated, and the second backlight layer 28 can be deactivated for this area. In the segments where the display for the driver's position 16 is to be blocked, only the second backlight layer 28 can emit light, and the first backlight layer 24 can be deactivated for this area. Thus, the light is emitted only towards the passenger's position 14, and the display for a driver in this segment is dark.

[0050] In Fig. 3An exemplary process diagram for activating a privacy screen 20 for a motor vehicle 10 is shown. In step S10, it can first be determined whether the motor vehicle 10 is being driven in manual mode. That is, it can be checked whether a driver is controlling the motor vehicle or whether a computer system of the motor vehicle 10 is performing autonomous driving. In step S12, segments 18 of the display device 12 can then be determined on which a moving entertainment display is shown. In this way, the position of the entertainment display on the liquid crystal display can be determined by the display device 12.

[0051] In step S14, the privacy screen 20 can then be activated for those segments 18 in which the moving entertainment display has been detected, if it has been determined that the motor vehicle 10 is being driven in manual mode.

[0052] In another exemplary embodiment, one aspect is that the screen on the passenger side 14 of the vehicle 10 can be partially switched to a privacy mode. That is, the screen can be divided into areas (segments 18) in which the display from the direction of a driver's side (driver position 16) can be restricted so that this area can no longer be viewed by a driver (privacy mode).

[0053] The privacy mode can be activated in a predefined area of ​​the LCD or in multiple zones. These zones can be created, for example, by means of several LC cells arranged between a backlight (backlight 24) and the LCD (liquid crystal display layer 26).

[0054] This eliminates the need to turn off the entire screen in the passenger area for the driver. All static content, such as status bars, controls, time, information, and so on, remains visible to both the passenger and the driver. This preserves the overall visual appearance of the instrument panel and avoids large black areas.

[0055] To achieve this, the screen can incorporate a technology that controls the direction of the visible light emitted from the display. This light direction is preferably switchable. Two states can be supported. First, a "public mode" in which the display content is visible from a wide angle. Both the driver and the front passenger can see the content on the screen in this mode. Second, a "privacy mode" in which the display light is directed and emitted at a narrow angle perpendicular to the display surface. The screen content is only visible to the front passenger. Little to no light is emitted towards the driver, resulting in a very dim display.

[0056] Preferably, the display is divided into 18 segments. Individual segments can be switched to privacy mode, while other segments remain in public mode. Ideally, a larger portion of the display is always in public mode, and only a sub-area is in privacy mode.

[0057] A technical solution can be achieved using LC (liquid crystal) cells, which are specifically designed to direct the light. For example, one or more layered TN (twisted nematic) cells can be used as LC cells or as an LC cell stack. The LC cells can be configured as full-surface segments arranged horizontally and / or vertically, or they can have other geometric shapes, such as diamonds or rectangles.

[0058] Another possible implementation uses a two-layer backlight 24, which can be partially or in segments 18 switched to privacy mode.

[0059] Overall, the examples show how the invention can provide partial privacy circuitry for displays.

Claims

1. A motor vehicle (10) having a display apparatus (12) that is situated on a dashboard of the motor vehicle (10), the display apparatus (12) having a liquid crystal display that is associated with at least one front seat passenger position (14), the liquid crystal display being subdivided into a plurality of segments (18), wherein each segment (18) has an electronically switchable view protection device (20) that is designed, in an activated state, to block a display image of the particular segments (18) from being displayed in the viewing direction of a driver position (16) and to allow it to be displayed in the viewing direction of the front seat passenger position (14), and in a deactivated state, to allow it to be displayed in both viewing directions, wherein the display apparatus (12) is designed to determine the segments (18) on which a moving entertainment display is being displayed and to activate the view protection device (20) for these segments (18), wherein in addition to a liquid crystal display layer (26) the liquid crystal display additionally has at least one liquid crystal cell layer, designed as a TN cell layer, as a view protection device (20), which is activatable segment by segment and is designed to collimate light beams in the viewing direction of the front passenger position (14) when voltage is applied; wherein the liquid crystal cell layer is switchable in such a way that a gridded structure in the liquid crystal cell layer results, so that the TN cell layer is a layer that is opaque to light, with individual holes in the TN cell layer that are switched to be transparent, wherein as a result of the holes, only parallel beams pass through and lateral beams are for the most part filtered out.

2. The motor vehicle (10) according to claim 1, wherein the at least one liquid crystal cell layer is situated between a backlight (24) of the liquid crystal display and the liquid crystal display layer (26) of the liquid crystal display, or at a surface of the liquid crystal display.

3. The motor vehicle (10) according to one of the preceding claims, wherein multiple liquid crystal cell layers situated one behind the other and aligned with one another are provided as the respective view protection device (20).

4. The motor vehicle (10) according to one of the preceding claims, wherein the segments (18) are designed as horizontal and / or vertical strips.

5. The motor vehicle (10) according to one of claims 1 through 3, wherein the segments (18) are designed as rectangles and / or rhomboids.

6. The motor vehicle (10) according to one of the preceding claims, wherein the display apparatus (12) is designed to determine whether the motor vehicle (10) is moving or is stationary, and / or whether the motor vehicle (10) is being operated manually or autonomously, and to activate the view protection device (20) if the motor vehicle (10) is moving and / or is operated manually, and to deactivate the view protection device (20) if the motor vehicle (10) is stationary and / or is being operated autonomously.

7. A method for activating a view protection device (20), with a motor vehicle (10) according to one of the preceding claims, wherein the method comprises the following steps: - determining (S10) whether the motor vehicle (10) is being driven in a manual driving operation; - determining (S12) segments (18) of the display apparatus (12) on which a moving entertainment display is being displayed; - activating (S14) the view protection device (20) in the segments (18) in which the moving entertainment display is being displayed, if the motor vehicle (10) is being driven in the manual driving operation.