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) which can be selectively operated in a shared mode and a privacy mode. In order to improve the electro-optical efficiency and effectiveness of the display device (10), the driving of the electro-optical panel (18) for switching between the privacy mode and the shared mode is different during daytime and when driving at night. In view of the brightness of the ambient light, only the electro-optical panel (18), also sometimes referred to as "privacy unit", has to be driven during daytime, which achieves a lower collimation of the light than at night. This brings a number of advantages for the operation of the display device (10).

Description

Technical Field

[0001] This invention relates to a display device, and more particularly to a display device for displaying information in a vehicle. Background Technology

[0002] In recent years, a trend has emerged in vehicle passenger compartment design where the dashboard is equipped with an optoelectronic display located opposite the passenger seats. This "passenger" display can be designed as a separate unit compared to other displays on the dashboard. However, there are also displays that extend across (and in some cases almost across) the entire width of the dashboard, thus having separate display areas allocated to the driver and passengers.

[0003] The optoelectronic display areas on the vehicle's dashboard that are primarily not intended for the driver should ideally operate in a mode where only passengers can view the electronic displays, thereby limiting the driver's visibility and preventing distraction while driving. Therefore, large optoelectronic display areas allocated to passengers, or optoelectronic displays specifically for passengers, can selectively operate in privacy or shared modes. For this purpose, the displays are equipped with optoelectronic panels that typically operate based on liquid crystal technology. These panels change their light radiation characteristics when a voltage is applied, allowing them to selectively switch from a state with wide light radiation characteristics (corresponding to shared mode) to a state that collimates the emitted light (and vice versa), consistent with the intended privacy mode.

[0004] Photoelectric panels used for the above purposes are described, for example, in DE-A-102020100790, US-A-2023 / 0205008 and WO-A-2023 / 057553. In principle, such liquid crystal-based photoelectric panels are of the ECB type (electro-controlled birefringence), TN type (twisted nematic), or PDLC type (polymer dispersed liquid crystal).

[0005] In principle, photoelectric panels are driven by applying different electrical operating voltages.

[0006] One drawback of photoelectric panels (hereinafter also referred to as "privacy cells") is that their transmittance decreases when they are driven to collimate light.

[0007] Therefore, in privacy mode, the optical efficiency of the privacy unit is reduced compared to its operation in shared mode, and this must be compensated for by increasing the light intensity so that the display device can still achieve the minimum required brightness in privacy mode, especially in the automotive industry.

[0008] Display devices capable of selectively operating in privacy mode or sharing mode are known from US-A-2017 / 0263208 and US-B-10347193. Summary of the Invention

[0009] The purpose of this invention is to improve the optical characteristics of a display device having an optoelectronic display that can selectively operate in privacy mode or sharing mode, while also increasing its efficiency.

[0010] To achieve this objective, the present invention proposes a display device, particularly a display device for displaying information in vehicles, which is equipped with: - A display surface used to display information; - Electro-optical display; - Light generating unit, used to generate light emitted from the display surface into the viewing space located in front of the display surface; - A photoelectric panel, particularly a photoelectric panel employing one of the aforementioned technologies or other concepts known in the prior art, has one or more privacy units, i.e., one or more layers for influencing radiation characteristics (i.e., the solid angle range of light emitted from the photoelectric panel), wherein the photoelectric panel can selectively operate in a shared mode or a privacy mode. - In privacy mode, the photoelectric panel collimates light into the viewing space, allowing only a portion of the viewing space to receive light; while in sharing mode, the photoelectric panel allows light to enter a larger area of ​​the viewing space compared to privacy mode. - A brightness sensor used to detect the intensity of ambient light; and - An electronic evaluation and control unit is used to control the light generating unit and the photoelectric panel. The evaluation and control unit receives measurement signals from the brightness sensor and outputs control signals to the light generating unit and the photoelectric panel. - Specifically, when the brightness sensor detects ambient light intensity exceeding a threshold, the evaluation and control unit controls the light generation unit and the photoelectric panel to operate in daytime mode; - Specifically, when the brightness sensor detects ambient light intensity that is lower than or equal to a threshold, the evaluation and control unit controls the light generation unit and the photoelectric panel to operate in night mode; -Among them, the evaluation and control unit controls the light generation unit to adjust the light intensity; -In this case, when the optoelectronic panel is running in privacy mode, the evaluation and control unit controls the light generation unit to produce light with a higher intensity than when the optoelectronic panel is running in sharing mode; -Among them, the evaluation and control unit controls the light generation unit to produce a higher intensity when running in daytime mode than when running in nighttime mode; -Among them, the evaluation and control unit controls the photoelectric panel in privacy mode to adjust the light collimation; and -The evaluation and control unit controls the photoelectric panel operating in privacy mode and night mode to produce higher light collimation than when operating in privacy mode and day mode.

[0011] The display device according to the invention is equipped with an electro-optic display, which is configured, for example, as an LCD display, an OLED display, or a display with micro-LEDs. Light from a display surface used to display information enters a viewing space located in front of the display surface. This light is provided by a light generating unit, which may alternatively be configured as a backlight generating unit or as an active unit of an optoelectronic display, such as in OLED displays and displays with micro-LEDs. The optoelectronic panel (privacy unit) can selectively operate in a shared mode or a privacy mode. In shared mode, light enters the viewing space with relatively broad radiation characteristics, while in privacy mode, the light is collimated so that it only enters a portion of the viewing space, i.e., towards the passenger.

[0012] The light generating unit and photoelectric panel are driven by an electronic evaluation and control unit, which typically includes a CPU, microcontroller, memory, I / O ports, digital-to-analog converter, analog-to-digital converter, etc. The evaluation and control unit receives measurement signals from a brightness sensor, which represent the ambient light intensity exposed to the vehicle or the device containing the display device of this invention.

[0013] As described above, when switching from shared mode to privacy mode, the light intensity of the light generation unit must be increased. This is because the transmittance of the privacy unit decreases, as mentioned above.

[0014] In principle, the light-generating unit emits higher intensity light during daytime operation than at nighttime operation. It has been found that to achieve privacy mode during the day, the required collimation of light passing through the photoelectric panel is lower than at night. This is due to the reflection of ambient light during the day, which is reflected from the display surface towards the passenger. This reduces the driver's visibility of the display surface. When switching to privacy mode, the same high light collimation is no longer needed as at night because no ambient light is reflected. This means that privacy mode can be achieved more efficiently during the day because the transmittance of the photoelectric panel (privacy unit) no longer needs to be reduced as much to achieve privacy mode. This improves the optical and energy efficiency of the display or display device.

[0015] During the dawn and dusk phases, the photoelectric panel can operate at a collimation level between that of daytime and nighttime operation.

[0016] Therefore, the brightness sensor can distinguish between daytime operation, nighttime operation, and dusk operation. According to the present invention, the evaluation and control unit controls the photoelectric panel in privacy mode to produce lower light collimation during the day than in nighttime privacy mode and / or dusk privacy mode.

[0017] According to the present invention, a brightness sensor with a corresponding driving device is provided, which adjusts the brightness of the display and the viewing angle limitation (i.e., switches between a shared mode and a privacy mode). The adjustment method is as follows: the brightness of the display is adjusted according to day or night, i.e., it is brightened or dimmed respectively. The viewing angle limitation is also adjusted according to day or night, i.e., it is weakened or strengthened respectively.

[0018] In an advantageous embodiment of the invention, the display is configured as an LCD display and has a back surface facing away from the display surface; the light generating unit is configured as a backlight generating unit and has a light emitting surface facing the back surface of the LCD display; and a photoelectric panel is disposed between the light emitting surface of the backlight generating unit and the LCD display, or between the display and the display surface. A diffusion layer is typically disposed between the backlight generating unit and the LCD display; if the photoelectric panel is located between the display and the backlight generating unit, the diffusion layer is disposed between the photoelectric panel and the display. The backlight generating unit can operate with the light source directly incident on the back surface of the light guide plate of the backlight generating unit, or with the light source incident from the side into the light guide plate (side-in).

[0019] Furthermore, it can be advantageously specified that the light-generating unit is constructed as a light-emitting pixel of the display, and the photoelectric panel receives light from the light-emitting pixel and transmits it to the display surface. For example, OLEDs or micro-LEDs are suitable as light-emitting pixels.

[0020] Furthermore, it can be advantageously specified that the photoelectric panel can be driven in a pixel-selective or region-selective manner, thereby enabling certain pixels or regions of the photoelectric panel to operate in a privacy mode while other pixels or other regions of the photoelectric panel operate in a shared mode. Such photoelectric panels capable of being driven in a pixel-selective or region-selective manner are described, for example, in WO-A-2023 / 057553A1 or WO-A-2023 / 232969. All publications cited herein, as well as the content of the aforementioned publications, are incorporated herein by reference into the subject matter of this application.

[0021] For example, it can be advantageously specified that the photoelectric panel includes at least two or more areas capable of operating independently in privacy mode or shared mode, or some areas capable of operating in shared mode while other areas simultaneously operate in privacy mode. In privacy mode (e.g., for passenger use), light for making information displayed on the display surface visible can be beamed to display areas aligned with these areas; while in shared mode, light for making information displayed on the display surface visible can be non-collimated to display areas aligned with these areas. Depending on whether the photoelectric panel is positioned behind or in front of the display, the aligned areas lie on the display surface.

[0022] Suitablely, it can also be specified that the areas on the display surface where information should be displayed in privacy mode and the areas where information should be displayed in sharing mode can be manually selected. In this regard, it is also advantageous to specify that the display surface is equipped with a touch sensor device, and that the areas where information should be displayed in privacy mode or sharing mode can be selected by touch markers. Furthermore, it can be advantageous to dim the light from the light generating unit when displaying information on a black background compared to displaying information on a white background on the display surface.

[0023] Also advantageously, when the operation of the photoelectric panel switches from shared mode to privacy mode and vice versa, whether operating during daytime or nighttime, the evaluation and control unit performs white balance on the light emitted from the display surface. This white balance is performed, in particular, based on the temperature of the display and / or the photoelectric panel. In this regard, in an advantageous configuration of the invention, the display device includes a temperature sensor for providing a measurement representing the temperature of the photoelectric panel and / or from which the temperature of the photoelectric panel can be derived, wherein the evaluation and control unit receives the measurement signal from the temperature sensor, and wherein the evaluation and control unit generates a control signal for the photoelectric panel to compensate for color variations in the light generating unit passing through the photoelectric panel due to the temperature-dependent effects of the photoelectric panel on the light color and / or due to the different effects of the photoelectric panel on the light color depending on whether it operates in shared mode or privacy mode.

[0024] A variation of the present invention provides a display device, particularly for use in vehicles, for displaying information, wherein the display device is equipped with: - A display surface used to display information; - Electro-optical display; - Light generating unit, used to generate light emitted from the display surface into the viewing space located in front of the display surface; - A photoelectric panel, particularly a photoelectric panel employing one of the aforementioned technologies or other concepts known in the prior art, comprising one or more privacy units, i.e., one or more layers for influencing radiation characteristics (i.e., the solid angle range of light emitted from the photoelectric panel), wherein the photoelectric panel can selectively operate in a shared mode or a privacy mode. - In privacy mode, the photoelectric panel collimates light into the viewing space, allowing only a portion of the viewing space to receive light; while in sharing mode, the photoelectric panel allows light to enter a larger area of ​​the viewing space compared to privacy mode. - A temperature sensor for providing a measurement representing the temperature of the photoelectric panel and / or from which the temperature of the photoelectric panel can be derived; and - The evaluation and control unit receives measurement signals from the temperature sensor and outputs control signals to the light generation unit and the photoelectric panel. -The evaluation and control unit generates control signals for the light generation unit to compensate for color variations of light passing through the light generation unit of the photoelectric panel due to temperature-dependent effects of the photoelectric panel and / or display on light color and / or due to different effects of the photoelectric panel on light color; said different effects are in particular caused by different degrees of light refraction produced by the photoelectric panel depending on whether it is operating in shared mode or privacy mode.

[0025] The white balance of displays employing various technologies is known in principle to depend on both temperature and the optical characteristics of the RGB light source (typically LED) required to generate light, which may vary between different product batches. In this invention according to this variation, the white balance now also takes into account the temperature of the photoelectric panel and its operation, i.e., whether the photoelectric panel is controlled for privacy mode or sharing mode. Since the transmittance of the photoelectric panel is reduced in privacy mode compared to sharing mode, as mentioned above, an increase in light intensity is required. This may be associated with increased operating temperatures of the photoelectric panel, light generating unit, and / or display, which is again taken into account in the white balance according to the invention.

[0026] Various parameters, particularly numerical values ​​related to temperature, selectable light intensity levels, and whether shared or private modes are activated, as well as control data for the colored light source used for white balance based on previous assumptions about the above parameters, are stored, for example, in a lookup table and retrieved by the evaluation and control unit.

[0027] According to one aspect of the invention, the control of the photoelectric panel in daytime and nighttime privacy modes is therefore associated with the display brightness conditions specified during the day and night, particularly in vehicles.

[0028] Because during the day, when the display device operates in privacy mode, only moderate light collimation of the photoelectric panel needs to be achieved, the light generating unit does not need to be designed at maximum power. However, if the photoelectric panel is operated at its maximum possible collimation during the day, it needs to be designed at maximum power. This results in reduced thermal stress, thereby enabling a cost-effective construction of the light generating unit.

[0029] At night, the photoelectric panel must provide stronger collimation for privacy mode, because otherwise the residual light emitted from the display surface would still be visible to the driver. However, since the power of the light-generating unit is lower during nighttime operation than during daytime operation, this also brings the advantages of reduced heat load and more efficient use of the display device.

[0030] To further improve the efficiency of display devices in privacy mode, the two operating modes of the optoelectronic panel can be combined with localized dimmable illumination of the display surface. This can significantly improve efficiency, especially when displaying information against a black background on the display surface. For example, when displaying video on a white background, the advantage of combining it with localized dimming for the optical efficiency of the display device remains significant.

[0031] When using OLED displays, combining a tandem OLED structure (high-brightness OLED) with a photoelectric panel is advantageous to compensate for the reduced transmittance of the photoelectric panel in privacy mode (compared to shared mode). In this case, the brightness levels required for automotive standards can be achieved in a manner similar to that of LCD displays. The daytime and nighttime operation of the photoelectric panel can be selected as needed to improve its transmittance or enhance the display's performance in privacy mode. Both approaches are highly beneficial in extending the OLED's lifespan when combined with an actively switchable photoelectric panel, as is the case with this invention.

[0032] Because the different degrees of light collimation required during the day and night modulate the transmission of light from the light-generating unit to the display surface, this can cause color shift, which should be compensated for through appropriate adjustments (e.g., white point adjustment). For example, this invention proposes to perform three calibrations on the optical performance of the display or the entire display device to avoid color differences when switching between day and night operation, as well as when switching from shared mode to privacy mode and vice versa within these modes.

[0033] According to another aspect of the invention, various strategies have been described above to compensate for the effects of different temperatures and on the functionality of the photoelectric panel in both privacy and sharing modes: Because the properties of liquid crystals change with temperature, the voltage used to drive the photoelectric panel is adjusted according to temperature to optimize collimation characteristics and color shift caused by the photoelectric panel. During calibration, the voltage is adjusted individually for each display device to ensure consistent performance.

[0034] Changes in liquid crystal properties can also cause color shifts, varying with temperature in both shared and privacy modes. For example, the color calibration lookup table (LUT) of a display or display device is adjusted according to temperature. This can be achieved through dynamic calculation or by using a predefined lookup table within a specific temperature range and depending on the mode (privacy mode or shared mode). Furthermore, activating privacy mode affects the white point of the emitted light compared to shared mode. According to one aspect of the invention, in addition to the privacy mode function, a separate white point profile is applied to achieve the same white point in both shared and privacy modes.

[0035] Furthermore, performance in privacy mode can be dynamically adjusted based on other environmental conditions, such as ambient light. Therefore, for example, privacy mode is more effective at reducing driver distraction in dark environments than in daylight. This adjustment can be combined with adjustments to the emitted light intensity to ensure consistent performance for passengers (i.e., viewers who continue to have maximum visibility of the display surface in privacy mode). Attached Figure Description

[0036] The present invention will now be described in more detail with reference to embodiments and the accompanying drawings. The drawings show in detail: Figure 1a and Figure 1b The diagram schematically illustrates components of a prior art display device, wherein a photoelectric panel is arranged between a backlight generating unit and an LCD display, wherein... Figure 1a The light distribution during operation in shared mode is shown. Figure 1b The light distribution during operation in privacy mode is shown; Figure 2a and Figure 2b The diagram schematically illustrates components of a prior art display device, wherein a photoelectric panel is arranged between a display and a cover plate of the display device, wherein... Figure 2a The light distribution during operation in shared mode is shown. Figure 2b The light distribution during operation in privacy mode is shown; Figure 3a The main components of an LCD display with a backlight generating unit, for example, without a privacy unit, are schematically shown. Figure 3b A display device having an LCD display, a backlight generating unit, and a privacy unit is shown; Figure 4 schematically illustrates the light emission distribution during the day, when ambient light is reflected from the display surface and particularly toward the driver; Figure 5 shows the light emission distribution of the display device at night, when there is no or virtually no reflection of ambient light.

[0037] Figure Labels 1. Existing display devices 1' Existing display devices 2 Backlight Generating Unit 2' Backlight generating unit 3. Light-emitting surface of the backlight generation unit 3' Light-emitting surface of the backlight generating unit 4. Optoelectronic Panel 4' Optoelectronic Panel 5. Electro-optical display 5' Electro-optical display 6. Viewing Space 6' Viewing Space 7. Cover plate 7' cover plate 8 Display Surface 10 Display devices 12 LCD monitors 14 Cover plate 16 Display Surface 18 Optoelectronic Panels 20 backlight generating units 22. Evaluation and Control Unit 24 Brightness Sensor 26 Temperature Sensor 28. Ambient light reflected towards the driver 30. Ambient light reflected towards passengers Detailed Implementation

[0038] Figure 1a , Figure 1b , Figure 2a , Figure 2b as well as Figure 3a , Figure 3b This illustrates a prior art display device solution that demonstrates the display device in a shared mode (see [link]). Figure 1a and 2a ) and privacy mode (see Figure 1b and 2b The operation is as follows. Two known variations of the display devices 1 and 1' respectively include backlight generating units 2 and 2', whose light is scattered from light-emitting surfaces 3 and 3'' respectively, and reaches the photoelectric panel 4 with relatively broad light radiation characteristics. The photoelectric panel is exemplarily shown here as including two privacy units (see [link to relevant documentation]). Figure 1a and 1b The photoelectric panel 4 operates based on liquid crystal technology. The liquid crystal orientation shown in these figures is merely symbolic and illustrates that, depending on the operation of the photoelectric panel, the backlight is either collimated or the outgoing light is not collimated, meaning the light passes through essentially unchanged. If no voltage is applied to the liquid crystal layer of the photoelectric panel 4, the photoelectric panel 4 is essentially "neutral" with respect to the radiation characteristics of the backlight, causing further scattering of the backlight to reach the LCD display 5 and exit from the LCD display into the viewing space 6 or 6' in front of the typically present display cover 7, particularly displaying information in color in the form of alphanumeric characters or graphics or graphic symbols. Only polarization modulation of the light occurs, but this has virtually no effect on the radiation characteristics, i.e., the transmission of the backlight. The "neutral" behavior of the photoelectric panel 4 in... Figure 1a As shown in the middle, Figure 1bThis explains how the collimation of light emitted from the optical panel 4 is achieved in privacy mode. At this time, the liquid crystal is aligned (by applying a working voltage to the photoelectric panel), so that light is normally emitted from the cover plate 7 along the normal direction of the display surface 8.

[0039] Figure 2a and Figure 2b An alternative arrangement of the main components of the display device is shown, which is capable of operating in both shared and privacy modes simultaneously. Figure 2a and Figure 2b The display device 1' in Figure 1a and Figure 1b The structural difference of the display device 1 is that the photoelectric panel 4' (also shown here exemplarily as having two privacy units) is arranged between the electro-optical display 5' and the cover plate 7'. In this configuration, the display 5' can also be constructed as a self-emissive display (e.g., using OLED or micro LED), but then the backlight generating unit 2' is not required.

[0040] For the sake of completeness, Figure 3a The diagram shows the backlight generating unit 2 and the electro-optical display 5 with a cover plate 7, but the display device cannot operate in privacy or shared modes. As mentioned above, this requires an optoelectronic panel 4 to form... Figure 3b The structure shown.

[0041] Finally, Figures 4 and 5 illustrate exemplary embodiments of the display device 10 of the present invention operating during the day and night. In this exemplary embodiment, the display device 10 operates based on a backlit LCD display 12 located behind a cover plate 14, the front surface of which forms the display surface 16. Behind the LCD display 12 is a photoelectric panel 18 for transmitting diffused backlight in shared mode, or emitting backlight in the form of collimated light in privacy mode. The backlight is generated by a backlight generating unit 20, which may be configured, for example, as a direct-lit BLU (backlight unit) or an edge-lit BLU. The luminance (cd) values ​​shown in Figures 4 and 5 are merely exemplary and are typical values ​​in the automotive field.

[0042] Components such as the display 12, the optoelectronic panel 18, and the backlight generating unit 20 are controlled by an electronic evaluation and control unit 22, which typically includes a microprocessor with a CPU, ROM, RAM, and digital-to-analog converters, analog-to-digital converters, and I / O interfaces. In this exemplary embodiment, the evaluation and control unit 22 receives measurement signals from a brightness sensor 24, which detects the brightness around the vehicle or the device on which the display is mounted; and from a temperature sensor 26, which provides information about the temperature of the display device, particularly the temperature of the optoelectronic panel.

[0043] As described above, the distribution of light emitted from the photoelectric panel 18 is influenced by appropriately driving the photoelectric panel. Here, the transmittance varies depending on whether the light is emitted in a scattered, focused, or collimated manner. When the light is emitted in a collimated manner, the transmittance is lower than when the light is emitted in a scattered manner. The reduced transmittance results in a decrease in the brightness, i.e., the amount of light, emitted by the display surface 16. Therefore, the backlight intensity must be increased in privacy mode to compensate for this effect. However, this in turn means that the overall electrical and electro-optical efficiency of the display device 10 is lower in privacy mode compared to operation in shared mode.

[0044] People are committed to keeping the resulting losses as low as possible.

[0045] During the development of this invention, it was recognized that ambient light illuminating the display surface 16 during the day is reflected, particularly towards the driver (see Figure 4). This reflected ambient light 28 impairs the driver's visibility and ability to recognize the information displayed on the display surface 16. Conversely, the portion 30 of ambient light reflected towards the passenger is extremely small and essentially negligible. If it is now desired to switch from shared mode to privacy mode during the day, such strong light collimation is no longer necessary because the light scattered from the display surface 16 towards the driver is almost invisible due to the reflected ambient light portion 28. However, this also means that the photoelectric panel 18 does not experience a significant decrease in transmittance when operating in privacy mode, as will be further illustrated in Figure 5. Therefore, the efficiency and effectiveness of the display device 10 during daytime operation can be improved by this measure (i.e., lower collimation in privacy mode).

[0046] At night (see Figure 5), the portion 28 of ambient light reflected from the display surface 16 to the driver disappears (or is significantly reduced) because this portion is very small. Therefore, during nighttime operation, the photoelectric panel 18 must be driven at a higher operating voltage to significantly reduce the driver's visibility of the display surface 16. However, since the overall intensity of the backlight can be reduced during nighttime operation (at which point the visibility of the display surface 16 is no longer "obstructed" by brightness for the driver and passengers as it is during the day), this in turn leads to improved efficiency and effectiveness, thereby improving the efficiency of the display device 10 according to the invention even at night.

[0047] Finally, the difference in absorption, reflection, and scattering effects of the photoelectric panel in privacy mode compared to shared mode also leads to an increase in the operating temperature of the display device, particularly the photoelectric panel 18. It is well known that this temperature change causes a change in the composition of the light passing through the photoelectric panel 18. This, in turn, affects the color of the light emitted from the display panel 16. It is well known that the temperature effect can be compensated for through so-called white balance.

[0048] According to a preferred embodiment of the display device 10 described herein, dynamic white balance control is achieved by detecting the temperature of the display device or a measurement representing that temperature using a temperature sensor 26. A key feature is that the white balance is not only based on temperature but also depends on whether the photoelectric panel 18 is operating in shared or private mode. In addition to the thermal behavior changes caused by increased light intensity in private mode, different light refraction in the photoelectric panel compared to shared mode also causes changes in the composition of light, resulting in changes in the color of the light, which must also be compensated for. This is done, for example, in the evaluation and control unit 22, where parameters for controlling the RGB light source of the backlight generation unit 20 are retrieved from, for example, a lookup table based on temperature and conditions such as private or shared mode. Therefore, various scenarios have been pre-rehearsed, and control parameters for the backlight generation unit light source determined for each scenario are selected accordingly, thereby always achieving a satisfactory white balance and ensuring that the color of the light (typically white) does not change for the viewer.

Claims

1. A display device, particularly a display device for displaying information for vehicles, comprising: - Display surface (16) for displaying information. - Electro-optical display (12). - A light generating unit (20) for generating light emitted from the display surface (16) into a viewing space located in front of the display surface (16). - The optoelectronic panel (18) is capable of selectively operating in shared mode or privacy mode. - in, In the privacy mode, the photoelectric panel (18) collimates light into the viewing space, thereby allowing light to enter only a portion of the viewing space; while in the sharing mode, compared to the privacy mode, the photoelectric panel (18) allows light to enter a larger area of ​​the viewing space. - A brightness sensor (24) is used to detect ambient light intensity, and - An electronic evaluation and control unit (22) is used to control the light generating unit (20) and the photoelectric panel (18). The evaluation and control unit receives measurement signals from the brightness sensor (24) and outputs control signals to the light generating unit (20) and the photoelectric panel (18). - Wherein, when the brightness sensor (24) detects an ambient light intensity higher than a threshold, the evaluation and control unit (22) controls the light generation unit (20) and the photoelectric panel (18) to operate in daytime mode; - Wherein, when the brightness sensor (24) detects an ambient light intensity that is lower than or equal to a threshold, the evaluation and control unit (22) controls the light generation unit (20) and the photoelectric panel (18) to operate in night mode; - Wherein, the evaluation and control unit (22) controls the light generation unit (20) to adjust the intensity of the light; - Wherein, when the photoelectric panel (18) is running in privacy mode, the evaluation and control unit (22) controls the light generation unit (20) to generate light with a higher intensity than when the photoelectric panel (18) is running in sharing mode; - Wherein, the evaluation and control unit (22) controls the light generation unit (20) to generate a higher intensity when operating in daytime mode than when operating in nighttime mode; - Wherein, the evaluation and control unit (22) controls the photoelectric panel (18) in privacy mode to adjust the light collimation; and - The evaluation and control unit (22) controls the photoelectric panel (18) in privacy mode and night mode to produce higher light collimation than in privacy mode and day mode.

2. The display device according to claim 1, characterized in that, The display (12) is configured as an LCD display and has a back surface opposite to the display surface (16). The light generating unit (20) is configured as a backlight generating unit and has a light emitting surface facing the back surface of the LCD display. The photoelectric panel (18) is arranged between the light emitting surface of the backlight generating unit and the LCD display or in front of the display.

3. The display device according to claim 1, characterized in that, The light generating unit is configured as a light-emitting pixel of the display, and the photoelectric panel (18) receives light from the light-emitting pixel and transmits it to the display surface (16).

4. The display device according to any one of claims 1 to 3, characterized in that, The photoelectric panel (18) can be driven in a pixel-selection or region-selection manner, so that the pixels or regions of the photoelectric panel (18) operate in privacy mode, while the other pixels or other regions of the photoelectric panel operate in sharing mode.

5. The display device according to any one of claims 1 to 4, characterized in that, The areas on the display surface (16) where information should be displayed in privacy mode and the areas where information should be displayed in sharing mode can be manually selected.

6. The display device according to claim 5, characterized in that, The display surface (16) is equipped with a touch sensor device and can select the area where information should be displayed in privacy mode or sharing mode by touch mark.

7. The display device according to any one of claims 1 to 6, characterized in that, Compared to displaying information on a white background on the display surface (16), the light from the light generating unit (20) can be dimmed when displaying information on a black background.

8. The display device according to any one of claims 1 to 7, characterized in that, When the operation of the photoelectric panel (18) switches from shared mode to privacy mode and vice versa, the evaluation and control unit (22) performs white balance on the light emitted from the display surface (16) during operation, whether during daytime or nighttime.

9. The display device according to any one of claims 1 to 8, characterized in that, A temperature sensor (26) is provided to provide a measurement value representing the temperature of the photoelectric panel (18) and / or from which the temperature of the photoelectric panel (18) can be derived, wherein the evaluation and control unit (22) receives the measurement signal from the temperature sensor (26), and wherein the evaluation and control unit (22) generates a control signal for the photoelectric panel (18) to compensate for the color change of light passing through the light generation unit (20) of the photoelectric panel (18) due to the temperature-dependent effect of the photoelectric panel (18) on the color of light and / or due to the different effects of the photoelectric panel (18) on the color of light depending on whether it operates in shared mode or privacy mode.

10. A display device, particularly for vehicles, for displaying information, especially the display device according to any one of the preceding claims, comprising: - Display surface (16) for displaying information. - Electro-optical display (12). - A light generating unit (20) for generating light emitted from the display surface (16) into a viewing space located in front of the display surface (16). - The optoelectronic panel (18) is capable of selectively operating in shared mode or privacy mode. - in, In the privacy mode, the photoelectric panel (18) collimates light into the viewing space, thereby allowing light to enter only a portion of the viewing space; while in the sharing mode, compared to the privacy mode, the photoelectric panel (18) allows light to enter a larger area of ​​the viewing space. - Temperature sensor (26) for providing a measurement value representing the temperature of the photoelectric panel (18) and / or from which the temperature of the photoelectric panel (18) can be derived; as well as - The evaluation and control unit (22) receives measurement signals from the temperature sensor (26) and outputs control signals to the light generation unit (20), the electro-optic display (12), and the photoelectric panel (18). - Wherein, the evaluation and control unit (22) generates control signals for the electro-optic display (12) and / or the photoelectric panel (18) to compensate for the color changes of light passing through the light generation unit (20) of the photoelectric panel (18) due to the temperature-dependent effects of the photoelectric panel (18) and / or the display (12) on the color of light and / or due to the different effects of the photoelectric panel (18) and / or the electro-optic display (12) on the color of light; the different effects are in particular caused by the different degrees of light refraction produced by the photoelectric panel (18) depending on whether it is operating in a shared mode or a privacy mode.

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