Display device, in particular for a vehicle, for displaying information

Abstract

The invention relates to a display device (10), in particular for a vehicle, for displaying information. The display device (10) comprises an electro-optical display (12) and can be selectively operated in a split mode and in a private mode. In order to increase the electro-optical efficiency and effectiveness of the display device (10), the optoelectronic panel (18) required to switch between the private mode and the split mode is actuated differently in the daylight than during nighttime travel. Namely, while taking into account the brightness of the ambient light, the optoelectronic panel (18) (sometimes also referred to as privacy cell) only needs to be actuated during the day so as to achieve a lower degree of light collimation than at night. Several advantages relating to the operation of the display device (10) are associated therewith.

Description

[0001] especially for a

[0002] information

[0003] The invention relates to a display device, in particular for a vehicle, for displaying information.

[0004] Recently, there has been a trend in vehicle passenger compartment equipment toward equipping instrument panels with optoelectronic displays located opposite the passenger seat. Such a "passenger" display can be designed as a separate unit from other displays on the instrument panel. However, there are also displays that extend across (possibly almost) the entire width of the instrument panel, thus providing different display areas for the driver and the passenger.

[0005] Those areas of optoelectronic displays on vehicle instrument panels that are not primarily intended for the driver should be capable of operating in a mode in which, ideally, only the passenger has access to the electronic display. Visibility for the driver is restricted to avoid distraction while driving. Therefore, the aforementioned areas of large-area optoelectronic displays assigned to the passenger, or the optoelectronic displays assigned to the passenger, can be operated either in private mode or in shared mode.For this purpose, the displays are equipped with optoelectronic panels, typically based on LCDs, which change their light emission characteristics by applying an electrical voltage and can thus be optionally converted from a state with a wide light emission characteristic, which corresponds to the split mode, to a state (and vice versa) in which they ensure collimation of the outgoing light, as intended for the private mode.

[0006] Optoelectronic panels used for the aforementioned purpose are described by way of example in DE-A-10 2020 100 790, US-A-2023 / 0205008, and WO-A-2023 / 057553. Such LCD-based optoelectronic panels are generally of the ECB (electrically controlled birefringence), TN (twisted nematic), or PDLC (polymer dispersed liquid crystal) type.

[0007] Basically, the optoelectronic panel is controlled by applying electrical operating voltages of different magnitudes.

[0008] A certain disadvantage of optoelectronic panels (hereinafter also referred to as privacy cells) is that their transmittance deteriorates when they are controlled to collimate the light.

[0009] In private mode, the optical efficiency of the privacy cell is reduced compared to its operation in split mode, which must be compensated by increasing the light intensity so that the display device in private mode still has the minimum brightness required, particularly in the automotive industry.

[0010] From US-A-2017 / 0263208 and US-B-10 347 193, display devices are known which can be operated either in private mode or in shared mode.

[0011] The object of the invention is to improve the optical properties of a display device with an optoelectronic display that can be operated either in private mode or in split mode, while increasing efficiency.

[0012] To achieve this object, the invention proposes a display device, in particular for a vehicle, for displaying information, which is provided with a display surface for displaying information, an electro-optical display, a light generating unit for generating light to be emitted from the display surface into a viewing space located in front of the display surface, an optoelectronic panel, in particular in one of the aforementioned technologies or according to other concepts known in the prior art, with one or more privacy cells, i.e. with one or more layers for influencing the radiation characteristic, i.e. the solid angle range within which the light emerges from the optoelectronic panel, wherein the optoelectronic panel can be operated optionally in a split mode or in a private mode,wherein the optoelectronic panel in private mode allows collimated light to enter the viewing space and thus only into a partial area of ​​the viewing space, and in split mode allows light to enter a larger area of ​​the viewing space than in private mode, a brightness sensor for detecting the intensity of ambient light and an electronic evaluation and control unit for controlling the light generation unit and the optoelectronic panel, which receives measurement signals from the brightness sensor and outputs control signals to the light generation unit and the optoelectronic panel, wherein the evaluation and control unit controls the light generation unit and the optoelectronic panel for their operation during the day when the brightness sensor detects an ambient light intensity above a threshold value, wherein the evaluation and control unit controls the light generation unit and the optoelectronic panel for operation at night,when the brightness sensor detects an ambient light intensity below or equal to the threshold value, wherein the evaluation and control unit controls the light generation unit to adjust the intensity of the light, wherein the evaluation and control unit controls the light generation unit to generate light with a higher intensity when the optoelectronic panel is operated in private mode than when the optoelectronic panel is operated in split mode, wherein the evaluation and control unit controls the light generation unit to generate a higher intensity when the optoelectronic panel is operated during the day than when the light generation unit is operated at night,wherein the evaluation and control unit controls the optoelectronic panel in its private mode to adjust the degree of light collimation, and wherein the evaluation and control unit controls the optoelectronic panel in its private mode and during its operation at night to generate a higher degree of light collimation than in its private mode and during its operation during the day.

[0013] The display device according to the invention is provided with an electro-optical display, which is designed, for example, as an LCD display, an OLED display, or a display with microLEDs. Light from a display surface for displaying information enters the viewing space located in front of the display surface. This light is supplied by a light generation unit, which is alternatively designed as a backlight light generation unit or as the active unit of the optoelectronic display, as is the case, for example, with OLED displays and displays with microLEDs. An optoelectronic panel (privacy cell) can be operated either in a split mode or in a private mode. In split mode, the light enters the viewing space with a comparatively wide radiation characteristic, whereas in private mode it is collimated and thus only reaches a partial area of ​​the viewing space, namely in the direction of the passenger.

[0014] The light generation unit and the optoelectronic panel are controlled by an electronic evaluation and control unit, which typically includes a CPU, a microcontroller, memory, I / O ports, DAC, ADC, and the like. The evaluation and control unit receives a measurement signal from a brightness sensor that is representative of the ambient light intensity to which the vehicle or the unit comprising the display device according to the invention is exposed.

[0015] As described above, the intensity of the light from the light-generating unit must be increased when switching from split mode to privacy mode. This is due to the reduced transmittance of the privacy cell, as mentioned above.

[0016] In principle, the light-generating unit emits its light with greater intensity during daytime operation than during nighttime operation. It has now been shown that to implement the privacy mode, the light passing through the optoelectronic panel needs to be collimated to a lesser degree during the day than during nighttime operation. This is due to the reflection of ambient light during the day, which is reflected by the display surface toward the passenger.

[0017] This already reduces the driver's visibility of the display. When switching to privacy mode, the strong light collimation required at night is no longer necessary, as is the case when no ambient light is reflected. This allows privacy mode to be implemented more effectively during the day, as the degree of transmission of the optoelectronic panel (privacy cell) no longer needs to be reduced as much to enable privacy mode. This increases the optical and energy efficiency of the display or display device.

[0018] During the dawn and dusk phases, the optoelectronic panel can be operated at collimation levels that lie between those during daytime operation and those during nighttime operation.

[0019] The brightness sensor can therefore distinguish between daytime operation, nighttime operation, and twilight operation. According to the invention, the evaluation and control unit controls the optoelectronic panel in daytime privacy mode to generate a lower degree of light collimation than in nighttime privacy mode and / or in twilight privacy mode.

[0020] According to the invention, a brightness sensor with corresponding control is provided which regulates the display brightness and viewing angle restriction (i.e. switches between sharing mode and private mode) in such a way that the display illumination is adjusted depending on day and night, namely brighter or darker. The viewing angle restriction is also adjusted depending on day and night, namely weaker or stronger. In an advantageous embodiment of the invention, it can be provided that the display is designed as an LCD display and has a rear side facing away from the display surface, that the light generation unit is designed as a backlight light generation unit and has a light exit side facing the rear of the LCD display, and that the optoelectronic panel is arranged between the light exit side of the backlight light generation unit and the LCD display or between the display and the display surface.A diffuser layer is typically located between the backlighting light generation unit and the LCD display. If the optoelectronic panel is located between the display and the backlighting light generation unit, this diffuser layer is positioned between the optoelectronic panel and the display. The backlighting light generation unit can operate with direct irradiation of the light sources into the back of the light guide plate of the backlighting light generation unit, or the light from the light sources can be irradiated laterally into the light guide plate (edge ​​lit).

[0021] Furthermore, it can advantageously be provided that the light-generating unit is designed as light-emitting pixels of the display, and that the optoelectronic panel receives the light from the light-emitting pixels and has the display surface. Suitable light-emitting pixels include, for example, OLEDs or micro-LEDs.

[0022] Advantageously, it can further be provided that the optoelectronic panel can be controlled pixel- or area-selectively, thus allowing pixels or areas of the optoelectronic panel to be operated in the private mode while simultaneously operating other pixels or other areas of the optoelectronic panel in the split mode. Such pixel- or area-selectively controllable optoelectronic panels are described by way of example in WO-A-2023 / 057553 A1 or in WO-A-2023 / 232969. The contents of all publications cited here and those cited above are hereby incorporated by reference into the subject matter of the present application.Advantageously, for example, it can be provided that the optoelectronic panel has at least two or more than two areas that can be operated independently of one another either in private mode or in split mode, or that some areas can be operated in split mode and the other areas in private mode at the same time, in which light can be transmitted in a bundled manner to regions of the display that are aligned with these areas for the visibility of the information to be shown on the display surface when operating in private mode (for example, for the front passenger), and in which light can be transmitted in a non-collimated manner to regions of the display that are aligned with these areas for the visibility of the information to be shown on the display surface when operating in split mode. Depending on the arrangement of the optoelectronic panel, the aligned regions are then behind or in front of the display on the display surface.

[0023] It can also be expediently provided that areas of the display surface in which the visibility of the information displayed there is to take place in private mode and areas of the display surface in which the visibility of the information displayed there is to take place in split mode can be manually selected. In this regard, it can also advantageously be provided that a touch sensor is assigned to the display surface and that the areas in which the visibility of the information displayed there is to take place in private mode or in split mode can be selected by marking by touch. Furthermore, it can be advantageous if the light of the light generating unit is dimmable when information is displayed on a black background compared to when information is displayed on a white background of the display surface.

[0024] It is also advantageous if the evaluation and control unit performs a white balance for the light emitted by the display surface when switching the operation of the optoelectronic panel from split mode to private mode and vice versa, both during daytime and nighttime operation. Such white balances are performed, in particular, depending on the temperature of the display and / or the optoelectronic panel.In an advantageous embodiment of the invention in this regard, the display device has a temperature sensor for providing a measured value which is representative of the temperature of the optoelectronic panel and / or from which the temperature of the optoelectronic panel can be derived, wherein the evaluation and control unit receives measurement signals from the temperature sensor and wherein the evaluation and control unit generates the control signals for the optoelectronic panel for compensating for color changes in the light of the light generating unit passing through the optoelectronic panel due to temperature-dependent influence of the color of the light by the optoelectronic panel and / or due to a different influence of the color of the light by the optoelectronic panel depending on its operation in split mode and in private mode.

[0025] A variant of the invention provides a display device, in particular for a vehicle, for displaying information, wherein the display device is provided with a display surface for displaying information, an electro-optical display, a light generation unit for generating light to be emitted from the display surface into a viewing space located in front of the display surface, an optoelectronic panel, in particular in one of the aforementioned technologies or according to other concepts known in the prior art, with one or more privacy cells, i.e. with one or more layers for influencing the radiation characteristic, i.e. the solid angle range within which the light emerges from the optoelectronic panel, wherein the optoelectronic panel can be operated optionally in a split mode or in a private mode,wherein the optoelectronic panel in private mode allows collimated light to enter the viewing space and thus only into a partial area of ​​the viewing space, and in split mode allows light to enter a larger area of ​​the viewing space than in private mode, a temperature sensor for providing a measured value that is representative of the temperature of the optoelectronic panel and / or from which the temperature of the optoelectronic panel can be derived, and an evaluation and control unit that receives measurement signals from the temperature sensor and outputs control signals to the light generation unit and the optoelectronic panel,wherein the evaluation and control unit generates the control signals for the light generation unit to compensate for color changes of the light passing through the optoelectronic panel of the light generation unit due to temperature-dependent influence of the color of the light by the optoelectronic panel and / or by the display and / or due to a different influence of the color of the light by the optoelectronic panel, in particular as a result of different degrees of refraction of the light in the optoelectronic panel depending on its operation in split mode and in private mode.

[0026] The white balance of displays of various technologies is generally known. It depends on the temperature, on the one hand, and on the optical properties of the RGB light sources (typically LEDs) required for light generation, on the other hand. These properties can vary between different product batches. In the invention according to this variant, the temperature of the optoelectronic panel and its operation are also taken into account in the white balance, namely whether the optoelectronic panel is controlled for private mode or split mode.Due to the reduction in the transmittance of the optoelectronic panel in the private mode compared to its control for the split mode, as already mentioned above, an increase in the light intensity is required, which may be associated with an increase in the operating temperature of the optoelectronic panel, the light generating unit and / or the display, which in turn is taken into account in the white balance according to the invention.

[0027] The various parameters, particularly concerning the temperature, if applicable the level of light intensity and whether the split mode or the private mode is active, and the control data for the color light sources for the white balance with previously assumed combinations of the above parameters are stored, for example, in a lookup table which is accessed by the evaluation and control unit.

[0028] According to one aspect of the invention, the control of the optoelectronic panel in the private mode during the day and at night is coupled with the conditions of the display brightness which are specified during the day and at night, in particular in vehicles.

[0029] Because the optoelectronic panel only needs to be controlled to achieve moderate light collimation during daytime operation of the display in privacy mode, the light generation unit does not need to be designed for maximum performance, as would be the case if the optoelectronic panel were also operated with the maximum possible degree of collimation during the day. This leads to reduced thermal stress and thus a cost-effective design of the light generation unit.

[0030] At night, the optoelectronic panel must provide stronger collimation for privacy mode, as the residual light emitted by the display would otherwise still be sufficient for the driver to see the display. However, since the power of the light generating unit is lower during nighttime operation than during daytime operation, the advantage of reduced thermal load and more efficient use of the display device is also achieved.

[0031] To further increase the efficiency of the display in private mode, the two operating modes of the optoelectronic panel can be combined with locally dimmable illumination of the display surface. This can significantly improve efficiency, especially when the display surface displays information against a black background. When displaying, for example, videos against a white background, the advantage of combining this with local dimming for the optical efficiency of the display is still considerable.

[0032] When using an OLED display, a tandem OLED structure (high-brightness OLED type) in combination with the optoelectronic panel can be particularly advantageous to compensate for the drop in transmittance of the optoelectronic panel in privacy mode (compared to split mode). In this case, the luminance level for automotive standards can be achieved in a similar way to LCD displays. Day and night operation of the optoelectronic panel is selected as needed to increase the transmittance of the optoelectronic panel or to enhance the effectiveness of the display in privacy mode. Both are very helpful for extending the service life of OLEDs when combined with an actively switchable optoelectronic panel, as in the case of the invention.

[0033] Since the different degrees of collimation of the light required during day and night modulate its transmission from the light-generating unit to the display surface, this leads to a color shift that should be compensated for by appropriate adjustment (e.g., white point adjustment). For example, the invention proposes calibrating the optical performance of the display or the entire display device three times to avoid color differences when switching between day and night operation, and within these modes from shared mode to private mode and vice versa.

[0034] According to a further aspect of the invention, various strategies have been described above to compensate for the effects of the operation of the optoelectronic panel at different temperatures and in both private and shared modes:

[0035] Since the properties of liquid crystals change at different temperatures, the voltage driving the optoelectronic panel is adjusted depending on the temperature to optimize the collimation properties and the color shift induced by the optoelectronic panel. The voltage is individually adjusted for each display device in a calibration process to ensure consistent performance.

[0036] Changes in the properties of the liquid crystals also lead to a color shift, both in shared and private modes, over temperature. For example, the color calibration lookup tables (LUTs) of the display or display device are adjusted depending on the temperature. This can be done through dynamic calculations or by using predefined LUTs at specific temperature ranges and depending on the mode (private mode or shared mode). Furthermore, activating private mode influences the white point of the emitted light compared to shared mode. According to one aspect of the invention, individual white point profiles are applied, which are used in addition to the private mode function, to achieve the same white point in both shared mode and private mode.

[0037] In addition, performance in private mode can be dynamically adjusted depending on other environmental conditions such as:

[0038] B. Ambient light. For example, the privacy mode function may be more effective in dark ambient conditions to minimize driver distraction than in daylight, for example. This setting can be combined with the adjustment of the emitted light intensity to ensure consistent performance for the passenger, i.e., the viewer who continues to have maximum visibility of the display area in privacy mode.

[0039] The invention is explained in more detail below using an exemplary embodiment and with reference to the drawing. In detail:

[0040] Figs. 1a and 1b schematically show the components of a display device according to the prior art, in which the optoelectronic panel is arranged between a backlight light generation unit and an LCD display, wherein Fig. 1a shows the light distribution during operation in split mode and Fig. 1b shows the light distribution during operation in private mode,

[0041] Figs. 2a and 2b schematically show the components of a display device according to the prior art, in which the optoelectronic panel is arranged between the display and the cover plate of the display device, wherein Fig. 2a shows the light distribution when operating in split mode and Fig. 2b shows the light distribution when operating in private mode,

[0042] Fig. 3a schematically shows the main components of an example

[0043] LCD displays with backlight light generation unit without privacy cell,

[0044] Fig. 3b a display device with LCD display and backlight light generation unit as well as with a privacy cell,

[0045] Fig. 4 shows schematically the light emission distribution during the day when ambient light is reflected from the display surface, among other things, towards the driver, and

[0046] Fig. 5 shows the light output distribution of the display device during the night, in which there is no or essentially no reflection of ambient light.

[0047] Figs. 1a, 1b, 2a and 2b, and 3a and 3b show concepts of display devices according to the prior art, illustrating the operation of the display device in split mode (see Figs. 1a and 2a) and in privacy mode (see Figs. 1b and 2b). The two variants of known display devices 1 and 1', respectively, have a backlight light generation unit 2 and 2', respectively, whose light emerges from a light exit side 3 and 3" in a scattered manner and with a comparatively broad light emission characteristic, and reaches an optoelectronic panel 4, which is shown here by way of example as having two layers of privacy cells (see Figs. 1a and 1b). The optoelectronic panel 4 operates on the basis of LC technology.The orientations of the liquid crystals illustrated in these figures are merely symbolic and illustrate that, depending on the operation of the optoelectronic panel, the backlighting light is collimated or not collimated, meaning that it is passed through essentially unchanged. If no electrical voltage is applied to the layer of the optoelectronic panel 4 comprising liquid crystals, the optoelectronic panel 4 is essentially "neutral" with respect to the radiation characteristics of the backlighting light, resulting in further scattering of the backlighting light, which reaches an LCD display 5, from which it exits into the viewing space 6 or 6' in front of the typically present cover plate 7 of the display device 1, displaying information, particularly in color, in the form of alphanumeric characters, graphics, or graphic symbols.Only a modulation of the polarization of the light occurs, which, however, has essentially no influence on the radiation characteristics, i.e., the transmission of the backlit light. The "neutral" behavior of the optoelectronic panel 4 is shown in Fig. 1a, while Fig. 1b illustrates how collimation of the light emerging from the optical panel 4 occurs in privacy mode. In this case, the liquid crystals are aligned (an operating voltage is applied to the optoelectronic panel), so that the light typically emerges from the cover plate 7 in the direction normal to the display surface 8.

[0048] Figs. 2a and 2b show an alternative arrangement of the main components of a display device that can be operated in both split mode and privacy mode. The difference in the structure of the display device 1' in Figs. 2a and 2b compared to that of the display device 1 in Figs. 1a and 1b is that the optoelectronic panel 4', which is also shown here by way of example as having two layers of privacy cells, is arranged between the electro-optical display 5' and the cover plate 7'. In this configuration, the display 5' can also be designed as a self-luminous display (for example with OLEDs or microLEDs), although this would then omit the backlight light generation unit 2'.

[0049] For the sake of completeness, Fig. 3a shows the components of the backlighting light generation unit 2 and the electro-optical display 5 with cover plate 7, without the possibility of operating this display device in private or split mode. As already mentioned above, this requires an optoelectronic panel 4, resulting in the structure shown in Fig. 3b.

[0050] Finally, Figs. 4 and 5 show an exemplary embodiment of a display device 10 according to the invention in daytime and nighttime operation. In this exemplary embodiment, the display device 10 operates on the basis of a backlit LCD display 12, which is located behind a cover plate 14, the front of which forms the display surface 16. Behind the LCD display 12 is an optoelectronic panel 18 for transmitting scattered backlight light for the split mode or for emitting the backlight light as collimated light in the private mode. The backlight light is generated by a backlight light generation unit 20, which can be designed, for example, as a direct BLU (backlight unit) or as an edge-lit BLU. The luminous intensity (Cd) values ​​specified in Figs. 4 and 5 are merely examples and typical for the automotive sector.

[0051] The components display 12, optoelectronic panel 18, and backlight light generation unit 20 are controlled, among others, by an electronic evaluation and control unit 22, which typically has a microprocessor with CPU, ROM, RAM, as well as DAC, ADC, and I / O interfaces. In this exemplary embodiment, the evaluation and control unit 22 receives measurement signals from, on the one hand, a brightness sensor 24 for detecting the brightness in the surroundings of the vehicle or in the surroundings of the unit in which the display device is installed, and from the temperature sensor 26, whose measurement signal provides information about the temperature of the display device and in particular the temperature of the optoelectronic panel. As already described above, the distribution of the light emerging from the optoelectronic panel 18 is influenced by appropriate control of the optoelectronic panel 18.The transmittance changes depending on whether the light exits scattered, focused, or collimated. When exiting as collimated light, the transmittance is lower than when exiting in scattered form. The reduced transmittance leads to a reduced luminance, or the amount of light, emerging from the display surface 16. In privacy mode, the intensity of the backlight light must be increased to compensate for this effect. However, this in turn indicates an overall lower electrical and electro-optical efficiency of the display device 10 in privacy mode compared to its operation in split mode.

[0052] Efforts are made to keep the associated losses as low as possible.

[0053] During the development of the invention, it was recognized that during the day, the ambient light striking the display surface 16 is reflected by it, particularly in the direction of the driver (see Fig. 4). This proportion 28 of reflected ambient light impairs the driver's visibility and recognizability of information displayed on the display surface 16. The proportion 30 of reflected ambient light in the direction of the passenger, on the other hand, is extremely small and can essentially be neglected. If one wishes to switch from split mode to private mode during the day, such strong light collimation is no longer required, since the light scattered from the display surface 16 in the direction of the driver is already barely visible due to the proportion 28 of reflected ambient light.This then also means that the optoelectronic panel 18 does not lead to such a severe deterioration in transmission when operated in private mode as is the case under other lighting conditions, which will be discussed in connection with Fig. 5. The efficiency and effectiveness of the operation of the display device 10 during the day can therefore be increased by this measure, i.e. a lower degree of collimation in private mode. During the night (see Fig. 5), the proportion 28 of ambient light reflected by the display surface 16 towards the driver disappears (or is significantly reduced) because this is very small. In night-time operation, the optoelectronic panel 18 must therefore be controlled with a higher operating voltage in order to significantly impair the visibility of the display surface 16 for the driver.However, since the overall intensity of the backlighting can be reduced during nighttime operation (the visibility of the display surface 16 is then no longer "obstructed" for both the driver and the passenger to the extent that it is the case due to the brightness during the day), this in turn results in increased efficiency and effectiveness and thus an improved efficiency of the display device 10 according to the invention, even at night.

[0054] The altered absorption, reflection, and scattering effects of the optoelectronic panel in private mode compared to those in split mode ultimately also cause an increase in the operating temperature of the display device, and in particular of the optoelectronic panel 18. It is known that such temperature changes lead to changes in the composition of the light passing through the optoelectronic panel 18. This, in turn, affects the color of the light emerging from the display surface 16. Compensating for temperature influences through so-called white balances is known.

[0055] According to a preferred embodiment of the display device 10 described here, dynamic white balance control is achieved by detecting the temperature of the display device or a measured value representing this temperature using the temperature sensor 26. The special feature is that the white balance is not only determined based on the temperature, but also depends on whether the optoelectronic panel 18 is operating in split mode or private mode. In addition to the changed thermal behavior caused by the increase in light intensity in private mode, the different light refractions in the optoelectronic panel in private mode compared to split mode also lead to changes in the composition of the light and thus to a change in the color of the light, which must also be compensated for.This occurs, for example, in the evaluation and control unit 22, in which the parameters for controlling the RGB light sources of the backlighting light generation unit 20 are taken from a look-up table, for example, depending on the conditions such as temperature and privacy mode or split mode. The various scenarios were therefore run through in advance, and the control parameters for the light sources of the backlighting light generation unit, determined depending on the various scenarios, were selected accordingly, so that a satisfactory white balance can always be achieved, meaning that the color of the light (typically white) does not change for the viewer.

[0056] LIST OF REFERENCE SYMBOLS Display device according to the prior art ' Display device according to the prior art Backlight light generation unit ' Backlight light generation unit Light exit side of the backlight light generation unit ' Light exit side of the backlight light generation unit Optoelectronic panel ' Optoelectronic panel Electro-optical display ' Electro-optical display Viewing space ' Viewing space Cover plate ' Cover plate Display surface Display device LCD display Cover plate Display surface Optoelectronic panel Backlight light generation unit Control unit Brightness sensor Temperature sensor Proportion of ambient light reflected to the driver Proportion of ambient light reflected to the front passenger

Claims

CLAIMS 1. A display device, particularly for a vehicle, for displaying information, comprising a display surface (16) for displaying information, an electro-optical display (12), a light-generating unit (20) for generating light to be emitted from the display surface (16) into a viewing space located in front of the display surface (16), an optoelectronic panel (18) that can be operated selectively in a split mode or in a private mode, wherein the optoelectronic panel (18) allows collimated light to enter the viewing space in private mode and thus only into a partial area of ​​the viewing space, and in split mode allows light to enter a larger area of ​​the viewing space than in the private mode, a brightness sensor (24) for detecting the intensity of ambient light, and an electronic evaluation and control unit (22) for controlling the light-generating unit (20) and the optoelectronic panel (18),which receives measurement signals from the brightness sensor (24) and outputs control signals to the light generation unit (20) and the optoelectronic panel (18), wherein the evaluation and control unit (22) controls the light generation unit (20) and the optoelectronic panel (18) for their operation during the day when the brightness sensor (24) detects an ambient light intensity that is above a threshold value, wherein the evaluation and control unit (22) controls the light generation unit (20) and the optoelectronic panel (18) for operation at night when the brightness sensor (24) detects an ambient light intensity that is below the threshold value or equal to it, wherein the evaluation and control unit (22) controls the light generation unit (20) to adjust the intensity of the light, wherein the evaluation and control unit (22) controls the light generation unit (20) when the optoelectronic panel (18) is operated in the private mode to generate light with a higher intensity than when the optoelectronic panel (18) is operated in the split mode, wherein the evaluation and control unit (22) controls the light generation unit (20) when it is operated during the day to generate a higher intensity than when it is operated at night, wherein the evaluation and control unit (22) controls the optoelectronic panel (18) in its private mode to adjust the degree of light collimation, and wherein the evaluation and control unit (22) controls the optoelectronic panel (18) in the private mode and when it is operated at night to generate a higher degree of light collimation than in Private mode and its operation during the day.

2. Display device according to claim 1, characterized in that the display (12) is designed as an LCD display and has a rear side facing away from the display surface (16), that the light generating unit (20) is designed as a backlight light generating unit and has a light exit side facing the rear of the LCD display and that the optoelectronic panel (18) is arranged between the light exit side of the backlight light generating unit and the LCD display or in front of it.

3. Display device according to claim 1, characterized in that the light generating unit is designed as light-emitting pixels of the display and that the optoelectronic panel (18) receives the light of the light-emitting pixels and transmits it to the display surface (16).

4. Display device according to one of claims 1 to 3, characterized in that the optoelectronic panel (18) is pixel- or can be controlled in an area-selective manner and thus pixels or areas of the optoelectronic panel (18) can be operated in the private mode and at the same time other pixels or other areas of the optoelectronic panel can be operated in the split mode.

5. Display device according to one of claims 1 to 4, characterized in that areas of the display surface (16) in which the visibility of the information displayed there is to take place in private mode and areas of the display surface (16) in which the visibility of the information displayed there is to take place in shared mode can be selected manually.

6. Display device according to claim 5, characterized in that the display surface (16) is assigned a touch sensor and that the areas in which the visibility of the information displayed there is to take place in private mode or in sharing mode can be selected by means of marking by touch.

7. Display device according to one of claims 1 to 6, characterized in that the light of the light generating unit (20) is dimmable when displaying information on a black background compared to the display of information on a white background of the display surface (16).

8. Display device according to one of claims 1 to 7, characterized in that the evaluation and control unit (22) carries out a white balance for the light to be emitted by the display surface (16) when switching the operation of the optoelectronic panel (18) from the split mode to the private mode and vice versa during operation both during the day and at night.

9. Display device according to one of claims 1 to 8, characterized by a temperature sensor (26) for providing a measured value which is representative of the temperature of the optoelectronic panel (18) and / or from which the temperature of the optoelectronic panel (18) can be derived, wherein the evaluation and control unit (22) receives measurement signals from the temperature sensor (26) and wherein the evaluation and control unit (22) generates the control signals for the optoelectronic panel (18) for compensating for color changes in the light of the light generating unit (20) passing through the optoelectronic panel (18) due to temperature-dependent influence of the color of the light by the optoelectronic panel (18) and / or due to a different influence of the color of the light by the optoelectronic panel (18) depending on its operation in split mode and in private mode.

10. A display device, in particular for a vehicle, for displaying information, in particular according to one of the preceding claims, comprising a display surface (16) for displaying information, an electro-optical display (12), a light generation unit (20) for generating light to be emitted from the display surface (16) into a viewing space located in front of the display surface (16), an optoelectronic panel (18) that can be operated selectively in a split mode or in a private mode, wherein the optoelectronic panel (18) in the private mode allows collimated light to enter the viewing space and thus only into a partial area of ​​the viewing space, and in the split mode allows light to enter a larger area of ​​the viewing space than in the private mode, a temperature sensor (26) for providing a measured value,which is representative of the temperature of the optoelectronic panel (18) and / or from which the temperature of the optoelectronic panel (18) can be derived, and an evaluation and control unit (22) which receives measurement signals from the temperature sensor (26) and outputs the control signals to the light generation unit (20), the electro-optical display (12) and the optoelectronic panel (18), wherein the evaluation and control unit (22) generates the control signals for the electro-optical display (12) and / or the optoelectronic panel (18) for compensating for color changes in the light of the light generating unit (20) passing through the optoelectronic panel (18) due to temperature-dependent influence on the color of the light by the optoelectronic panel (18) and / or by the display (12) and / or due to a different influence on the color of the light by the optoelectronic panel (18) and / or by the electro-optical display (12) depending in particular as a result of different degrees of refraction of the light in the optoelectronic panel (18) depending on its operation in split mode and in private mode.

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