Indicating device

Abstract

A display device, particularly for a vehicle, for displaying information includes an electronic display (10) having a front face with a display surface and a back face not facing the front face, and a backlight unit (12) for backlighting the display (10), the backlight unit (12) having a light emitting surface disposed opposite the back face of the display (10). The display device also includes an optoelectronic panel (16) disposed between the display (10) and the backlight unit (12). The optoelectronic panel (16) has a plurality of areas that can operate independently of each other. In these areas, the light incident from the backlight unit (12) can be transmitted in a bundle to the areas of the display (10) that respectively correspond to these areas for the visibility of the information displayed on the display surface during operation in the private mode, and can be scattered and transmitted to the areas of the display (10) that respectively correspond to these areas for the visibility of the information displayed on the display surface during operation in the share mode. Further, the display device includes an optoelectronic panel (16) for operating the areas in the private mode or the share mode, and an electronic control unit (26) for controlling the display and the backlight unit (12).

Description

Technical Field

[0001] The present invention relates to a display device for a vehicle for displaying information, particularly in a private mode or a shared mode.

Background Art

[0002] In recent years, the number and size of display devices in vehicles have been continuously increasing. At present, a display device that spreads across the entire width of the instrument panel is also envisioned. In addition, design proposals for arranging separate display devices on both the driver side and the passenger side are also known.

[0003] For safety reasons, the driver of a vehicle should not be distracted by the information displayed on the display device for passengers or a part of the area of the display device for passengers.

[0004] From US Patent Application Publication No. 2020 / 0319512, a display device is known in which light from the display surface is scattered or focused and emitted as viewed over the entire display surface. The backlight unit of this known display device has individually controllable and dimmable light sources. Thus, since individual areas of the display surface can be darkened, these areas are hardly visible from points outside the display surface when the focused light is emitted.

[0005] International Publication No. 2018 / 185476 describes an illumination system for a display device having a plurality of reflective refraction elements.

[0006] A touch screen operable in a private mode is described in US Patent No. 11187945.

[0007] Furthermore, US Patent Application Publication No. 2018 / 0082068 shows a display device provided with a dynamic private mode filter.

Prior Art Documents

Patent Documents

[0008] [Patent Document 1] U.S. Patent Application Publication No. 2020 / 0319512 [Patent Document 2] International Publication No. 2018 / 185476 [Patent Document 3] U.S. Patent No. 11187945 [Patent Document 4] U.S. Patent Application Publication No. 2018 / 0082068 [Patent Document 5] German Patent Application Publication No. 102020100709 [Patent Document 6] German Patent Application Publication No. 102020100790 [Patent Document 7] German Patent Application Publication No. 102020131013 [Patent Document 8] U.S. Patent No. 8388159 [Patent Document 9] German Patent Application Publication No. 1020211260248 [Patent Document 10] German Patent Application Publication No. 1020211260256 [Summary of the Invention] [Problems to be Solved by the Invention]

[0009] An object of the present invention is to provide a display device for a vehicle, which can selectively minimize the visibility of displayed information, particularly when viewing an area of a display device or a part of the display device from the driver's side. [Means for Solving the Problems]

[0010] To solve the above problems, the present invention proposes a display device for a vehicle for displaying information, an electronic display having a front surface with a display surface and a back surface opposite to the front surface, A backlight unit for backlighting the display, the backlight unit having a light emitting surface disposed opposite to the back surface of the display, An optoelectronic panel disposed between the display and the backlight unit, the optoelectronic panel having at least two or more areas operable in a private mode or a share mode independently of each other, The optoelectronic panel for operating the area in the private mode or the share mode, and an electronic control unit for controlling the display and the backlight unit Comprising In the area, the light incident from the backlight unit can be focused and transmitted to the area of the display that matches the area for the visibility of the information displayed on the display surface during operation in the private mode, and in the area in the share mode, for the visibility of the information displayed on the display surface, it can be scattered and transmitted to the area of the display that matches the area. It is a display device.

[0011] The concept according to the present invention first utilizes an optoelectronic panel disposed between the electronic display of the display device and its backlight unit. Due to this optoelectronic panel, it is controllable independently of each other, so that in areas operable differently, the light incident from the backlight unit on the display can be transmitted in a beam shape (hereinafter and above, referred to as "focused") or scattered. In the area of the display where the backlight light reaches in a focused manner, the displayed information can be clearly visible over the viewing angle, but the viewing angle at this time is limited compared to the viewing angle obtained when the area of the display is backlit by the scattered light of the backlight unit. For an example of the optoelectronic panel used according to the present invention, refer to the concept based on a known liquid crystal cell. Backlighting the area of the display with beam-shaped light corresponds to operating the display device or the area of the display in the private mode, and when the display is backlit with scattered light, the operation in the share mode is performed.

[0012] Thus, according to the present invention, the display surface can be locally operated, i.e., for a specific zone or region, in a shared mode or a private mode. For this purpose, an optoelectronic panel or, more generally, a layer based on liquid crystal (LC) technology that can focus or scatter the light transmitted through the panel by electrically controlling, for example, the area of the panel is used. Therefore, this layer or the optoelectronic panel is divided into individually controllable individual "pixels", and one pixel or a plurality of pixels constitute an area that can be controlled independently of each other.

[0013] The optoelectronic panel can specifically be designed as described, for example, in German Patent Application Publication No. 102020100709. Thus, the optoelectronic panel has a first polarizing plate, a second polarizing plate, a first liquid crystal layer, a first alignment layer, and a second alignment layer. The first polarizing plate and the second polarizing plate are arranged side by side along the optical axis of light. The first liquid crystal layer is provided between the first polarizing plate and the second polarizing plate. A first alignment layer is provided between the first polarizing plate and the first liquid crystal layer, and the second alignment layer is provided between the second polarizing plate and the first liquid crystal layer. The alignment direction of the first alignment layer is orthogonal to the alignment direction of the second alignment layer.

[0014] Alternatively, the above-mentioned "optical laminate" can be arranged in two rows one after the other to together constitute the optical panel of the display device according to the present invention.

[0015] For more details on the configuration examples of the above-mentioned optical panel according to the above two aspects, reference is made to German Patent Application Publication No. 102020100790 (especially refer to FIGS. 1 and 6 and the related description), and its content is incorporated herein by reference as constituting the subject matter of this PCT application.

[0016] In a preferred development form of the present invention, the backlight unit has a plurality of light sources, and among these, at least one or a group of light sources is respectively assigned to another one of the areas of the optoelectronic panel that can be independently controlled from each other, and at least one light source or a group of light sources assigned to the area of the optoelectronic panel operating in the private mode may be dimmable by the control unit. In this development form of the present invention, the visibility of the information displayed on the display device is further reduced by locally dimming the backlight light. This is achieved, for example, by using a backlight unit having a plurality of light sources, each light source having one or more light emitters and one reflector. Preferably, an LED is used as the light emitter. Therefore, in the area of the display where the assigned light source is dimmed, the information on the display device is displayed at a lower illuminance. In this way, the backlighting of the entire display has its brightness modulated. This is done when operating the selected area of the optoelectronic panel in the private mode. In this way, the control unit controls the optoelectronic panel and the backlight unit to match each other.

[0017] In another useful aspect of the present invention, the backlight unit includes a light guide plate and / or an optical film and / or a diffusion film, and a light source, and the backlight unit may be disposed on the back surface of the light guide plate and / or the optical film and / or the diffusion film, on the back surface opposite to the optoelectronic panel, or may be disposed opposite thereto with a gap therebetween. Here, the light source may have, for example, a light emitter and a reflector in the form of an LED. When arranging light sources on the back surfaces of these using a light guide plate and / or an optical film and / or a diffusion film (so-called direct-lit backlight unit), in order to prevent bright spots on the light-emitting surface, it may be necessary to homogenize the emitted light by providing shading or incorporating a structure into the light-emitting surface. Such countermeasure examples are described in German Patent Application Publication No. 102020131013 and U.S. Patent No. 8388159.

[0018] As described above, the feature of the present invention is that the area of the display to be operated in the private mode is adjustable or selectable. This includes a mode in which individual areas are predefined and a mode in which the operator can arbitrarily select an area. The latter can be achieved, for example, by inputting parameters defining individual areas, or in the case of a display device with a touch sensor system, by tapping or moving an object on the display surface to mark the area.

Effect of the Invention

[0019] If necessary, the display device according to the present invention may further have a feature of including a backlight unit for asymmetric light distribution. Asymmetric light distribution may be less affected in the sense of "being able to be symmetrized". Therefore, the luminance of the area with lower light intensity in the private mode usually becomes lower. And in the share mode, by increasing the light intensity of the light source, it is possible to meet the requirements for backlighting of the display particularly required for automotive applications.

[0020] Hereinafter, the present invention will be described in detail with reference to the drawings using embodiments.

Brief Description of the Drawings

[0021]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

DETAILED DESCRIPTION OF THE INVENTION

[0022] Privacy functions in displays have existed for several years, especially in the consumer market. In the simplest example, for instance, by using a dimming film to narrow the viewing angle of the display, a static privacy effect can be obtained.

[0023] Another approach is, for example, to use a dual backlight system to dynamically activate and deactivate privacy. In this case, in the sharing mode, a "normal" viewing experience is possible by illuminating with a wide viewing angle, while in the private mode, more focused or beam-like light emission is used. In this way, only viewers in the propagation direction of the focused light can comfortably view the content.

[0024] However, in these approaches, often some luminance is obtained even outside the intended viewing angle. Therefore, due to the human eye's adaptation ability to low-light environments, the visibility of the image remains, and privacy, especially in a dark environment, becomes insufficient.

[0025] The present invention is preferably used in the automotive field. FIG. 1 shows a view of the front part inside a vehicle as seen from the rear. On the passenger side, an LCD display 10 is provided. On this display, individual areas can be selectively operated in the sharing mode or the private mode. Modern vehicles may be equipped with a "Door-To-Door" display. In that case, it means that the display area arranged in front of the passenger can operate different areas in the private mode and the sharing mode.

[0026] According to the present invention, by combining a direct - type backlight system and a segmented optoelectronic privacy cell panel, it is possible to activate privacy effects independently of each other in individual areas of the display 10. The display 10 schematically shown in FIG. 2 includes a direct - type backlight unit 12, an optical film 14 for improving efficiency, as an example of the optoelectronic panel 16, a polymer - dispersed liquid crystal (PDLC) type privacy cell for "shaping" light emission, and a liquid - crystal display module 20 (LCD). A touch panel or a cover glass (both not shown) may be further disposed on its display surface. The privacy cell (shown as 18 in FIG. 2) can be controlled either entirely or only in selected areas.

[0027] In the display area used in the private mode, the light emission (see the arrow on the left in FIG. 1) is highly directional compared to the area in the share mode (see the arrow on the right adjacent).

[0028] For example, in the viewing angle where the privacy effect is exerted, such as the driver's position in a vehicle, the part of the display in the share mode is in a visible state, so it suppresses the eyes from fully adapting to the dark state. As a result, the visibility of the private - mode segment from the driver's viewing angle decreases, improving the subjective privacy performance and reducing distraction during vehicle driving (FIG. 3).

[0029] By adopting a locally dimmable direct - type backlight (see the light source 22 with a reflector 24 as needed in FIG. 2), the following second factor can be utilized to improve the privacy function of the display. Since the display areas in the activated private mode can be selectively dimmed, these areas become even less visible from the driver's field of vision.

[0030] In this case, as shown in FIG. 2, in order to operate (selectively for each privacy cell) in private mode or share mode, the electronic control unit 26 that controls the optoelectronic panel 16 or its individual privacy cells is also used for dimming the individual light sources 22.

[0031] FIG. 3 shows the visibility of the display area from different positions of the vehicle. The share mode area (shown with low dot density) has a high light density across the entire viewing angle and is visible to both the driver and the passengers. The display area in private mode (shown with high dot density) has a similarly good light density for the passengers, but the light density at the driver's position is very low, so it cannot be seen or is difficult to decipher from the driver's position. By making a specific area of the display or its display surface visible to the driver, the driver's eyes can be prevented from fully adapting to the low-visibility area operating in private mode. This improves the privacy performance as well.

[0032] Furthermore, when only a part of the display is in private mode (FIG. 4), new applications arise. When using the display for menu navigation, all parts can be made visible (FIG. 5a). Control elements such as temperature management can be made visible to all passengers in the vehicle (FIG. 5b, areas 1 and 2), while dynamic content such as movies and web activities can be displayed in areas 3 and 4 of the display with a privacy function for the driver. Even during menu navigation (FIG. 5c, areas 1 and 4), notifications can be displayed in a private mode in a part of the display (areas 2 and 3) to avoid distracting the driver and ensure the confidentiality of the messages.

[0033] By controlling the segments with a passive or active matrix corresponding to the number of local dimming zones by a direct-lit backlight, the number of segments can be further increased.

[0034] According to the present invention, basically, the switching between the two modes is performed pixel by pixel. Therefore, one pixel can be switched at a time. For this reason, the switchable area on the display can be arbitrarily controlled and selected. Therefore, basically, there are as many switchable segments as there are pixels on the display.

[0035] The concept according to the present invention can also be combined with other switchable or fixed privacy concepts. Examples thereof include the German Patent Application Publication No. 1020211260248 of October 7, 2021 or the German patent application with the invention name "Anzeigevorrichtung, insbesondere fuer ein Fahrzeug, mit umschaltbarem Teilungs- und Privat-Modus" (agent docket number: 212844DE. Filed on the same day as this patent application) or the German Patent Application Publication No. 1020211260256 of October 7, 2021 or the invention name "Anzeigevorrichtung, insbesondere fuer ein Fahrzeug, zum Anzeigen von Information mit asymmetrischer Hinterleuchtung" (agent docket number: 212845DE. Filed on the same day as this patent application), which are described therein.

[0036] The subject matter of the above patent application is incorporated by reference as constituting the content of this patent application.

[0037] In a display having a switchable privacy function for switching between a share mode and a private mode, as described in the present invention, this switching can be performed either manually or automatically. In automotive applications, for example, when it is detected by a camera observing the driver that the driver has looked in the direction of the passenger display or the passenger display area (eye tracking), it is useful for the display to automatically switch from the share mode to the private mode. Also, it may be useful to automatically switch to the private mode when a "video" is being displayed on the passenger display or in the passenger display area. Thus, there are various methods for the automatic switching from the share mode to the private mode. Therefore, the return to the share mode is also performed automatically. In a vehicle equipped with a seat occupancy recognition function, when it is detected that there is no one in the passenger seat, the automatic switching to the private mode can be omitted.

Explanation of Signs

[0038] 10 Display 12 Backlight Unit 14 Optical Film 16 Optoelectronic Panel 18 Privacy Cell of Optoelectronic Panel 20 LCD Display 22 Light Source 24 Reflector 26 Control Unit

Claims

1. A display device, particularly for a vehicle, for displaying information, comprising an electronic display (10) having a front face with a display surface and a rear face opposite to this front face, a backlight unit (12) for backlighting the display (10), the backlight unit (12) having a light-emitting surface arranged opposite to the rear face of the display (10), a optoelectronic panel (16) arranged between the display (10) and the backlight unit (12), the optoelectronic panel (16) having at least two or more areas operable independently of each other in a private mode or a share mode, an electronic control unit (26) for controlling the optoelectronic panel (16) to operate the areas in the private mode or the share mode, the display (10) and the backlight unit (12), and in the area, light incident from the backlight unit (12) can be transmitted in a bundle to the area of the display (10) that coincides with the area for the visibility of the information displayed on the display surface during operation in the private mode, and can be scattered and transmitted to the area of the display (10) that coincides with the area for the visibility of the information displayed on the display surface during operation in the share mode.

2. The backlight unit (12) is provided with a light guide plate and / or an optical film and / or a diffusion film, and particularly with light sources distributed in a matrix pattern, and the backlight unit (12) is On the back surface of the optoelectronic panel (16) of the above-described light guide plate and / or the above-described optical film and / or the above-described diffusion film, which is disposed on the back surface opposite to the above-described electronic panel (16) or is disposed opposite thereto with a space therebetween, the display device according to claim 1.

3. The display device according to claim 2, characterized in that the above-described light source (22) particularly has a light emitter such as an LED and a reflector.

4. The backlight unit (12) has a plurality of light sources (22), and at least one of them is respectively assigned to another one of the above-described areas of the optoelectronic panel (16) that can operate independently of each other. At least one light source (22) assigned to the area of the optoelectronic panel (16) that operates in the above-described private mode is dimmable by the above-described control unit (26). The display device according to any one of claims 1 to 3.

5. The display device according to any one of claims 1 to 4, characterized in that the above-described area of the above-described display surface is manually selectable for the visibility of the displayed information in the above-described private mode or the above-described share mode.

6. The display device according to claim 5, characterized in that a touch sensor system is assigned to the above-described display surface, and the above-described area of the above-described display surface is selectable by marking by contact.

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