Display system

Abstract

The invention relates to a display system comprising a display panel (4) with a surface and a backlight (6) configured to illuminate at least one image content generated by the display panel (4) with light having a luminance, wherein the display panel (4) is configured to emit, in a first case, only one image content at an angle of 90° relative to the surface, and in a second case, at least two image contents, each image content at an oblique angle relative to the surface, wherein the backlight (6) is configured in the first case to set a maximum for the luminance of the light at the angle of 90° relative to the surface, and wherein the backlight (6) is configured in the second case to set a uniform angular range for the luminance of the light relative to the surface in an angular range that includes the oblique angles.

Description

[0001] The invention relates to a display system and a method for displaying at least one image content.

[0002] The document US 8 936 373 B2 shows a multi-image display device for a vehicle.

[0003] A display device with a screen that can be switched between a private and a public mode is described in the document US 2011 / 018860 A1.

[0004] From document EP 847 208 A2 a system for generating variable viewing areas of a directional display device is known.

[0005] Against this background, one task was to optimize the representation of different image contents depending on the direction.

[0006] This object is achieved by a display system and a method having the features of the independent patent claims. Embodiments of the display system and the method are evident from the dependent patent claims and the description.

[0007] The display system according to the invention comprises a display panel or display with a flat or curved, for example slightly curved, surface and a backlight, wherein the backlight is designed to backlight, transilluminate and / or illuminate at least one image content or display content generated by the display panel with light having an angle-dependent adjustable luminance. The display panel is designed, in a first case, to emit or radiate only a single image content at a time in only one direction at an angle of 90° relative to the surface or perpendicular to the surface. In a second case, the display panel is designed to emit or radiate at least two different image contents simultaneously or at a time, each image content at an oblique angle greater than 90° or less than 90° relative to the surface.In the first case, when only one image content is to be emitted from the display panel perpendicular to the surface, the backlight is designed to set a maximum for the luminance of the light provided for illumination at an angle of 90° relative to the surface. In the second case, when the different image contents are to be emitted from the display panel at different oblique angles, the backlight is designed to set a largely uniform and / or constant value for the luminance of the light provided for illumination relative to the surface for the image contents in an angular range that includes the oblique angles or all oblique angles.

[0008] In one embodiment, the display panel is configured in the second case to emit two different image contents at two oblique angles relative to the surface. A first image content can be emitted at a first oblique angle of 90°-s1° and a second image content at a second oblique angle of 90°+s2°, where s1 and s2 are each greater than zero. If s1 = s2, both image contents are emitted symmetrically relative to a plane of symmetry of the display running perpendicular to the surface. Furthermore, the backlight is configured to set the uniform value for the luminance of the light relative to the surface at least between the two oblique angles.

[0009] In one embodiment, the backlight is configured to emit light in a directed manner, essentially only at an angle of 90°, in the first case, and to emit light uniformly relative to the surface in the second case. In the first case, a maximum for the luminance is set in the direction at an angle of 90°, taking into account that the light from the backlight is usually naturally scattered and cannot usually form a sharp maximum in the first case.

[0010] Furthermore, it is possible for the backlight to be configured to set a first angle-dependent maximum value or a maximum for the luminance in a first central angular range between 90°-d1° and 90°+d1°, and a second angle-dependent value for the luminance in a second broad angular range between 90°-d1°-d2° and 90°-d1° and between 90°+d1° and 90°+d1°+d2°, wherein the first value for the luminance is greater than the second value, and wherein d1 and d2 are each greater than zero. As a rule, d1 < d2.

[0011] In one embodiment, the backlight has two planes or layers or plies with light sources arranged parallel to one another, wherein a first layer is designed to generate a directed radiation characteristic perpendicular to the surface for the luminance in the first case, and a second layer is designed to generate a broad radiation characteristic for the luminance in the second case, which extends, for example, in the angular range between the first and the second oblique angle. In the first case, light sources of the first layer are to be switched or activated, and in the second case only light sources of the second layer are to be switched or activated, wherein in the first case, light sources of both layers can also be activated.

[0012] The backlight can be designed or referred to as a two-layer or two-layer backlight, with the second layer or layer producing the broad radiation characteristic and the first layer producing the directed radiation characteristic for the light and / or the respective luminance. Typically, only in the first case is / are the first layer or light sources located therein to be activated or activatable, with the second layer or light sources located therein also optionally being activated. In the second case, only the second layer or light sources located therein to be activated or activatable, while the first layer is deactivated. It is possible that by switching the backlight in a given case only one layer of the backlight is activated.In the first case, both layers can also be activated in combination, whereby the maximum luminance is set for the luminance at an angle of 90° or in a central angular range between 90°-d1° and 90°+d1°, and the lower uniform value is set in a wide angular range between 90°-d1°-d2° and 90°-d1° and between 90°+d1° and 90°+d1°+d2°.

[0013] In one embodiment, the backlight and / or at least one or a respective plane or layer of the backlight can have, as at least one light source, a light control film (LCF), light field technologies, microstructures, liquid crystals, light field emitters and / or electrophoretic particles and, alternatively or additionally, a refractive optic, e.g. a microprism, and / or a diffractive optic for bending light. In this case, a diffractive optic can be produced on the basis of a microstructured or nanostructured surface. In each case, the backlight is for generating light with a respective luminance, i.e. in the first case for generating or setting the maximum for the luminance at an angle of 90° or in a narrow central angular range relative to the surface and in the second case for generating orAdjusting the uniform luminance value across the intended wide angular range is achieved. The two-layered or two-layered backlight can have angle-dependent switchable emission characteristics, which influences the emission characteristics of the light through at least one switchable light source. The backlight is designed to couple light into the display panel at different angles or from different directions to illuminate the at least one image content.

[0014] A light field emitter can also be used as each or at least one light source of the backlight, with which both the position and the direction of the light to be generated and / or emitted can be varied. This light field emitter can be realized, for example, by combining light pixels with a lens array. Such a lens array comprises several individual lenses, each individual lens having a focal length. Each individual lens is located in front of a light pixel at a distance of its focal length. If a light pixel behind a lens is activated, the backlight or light field illumination emits a beam of rays whose propagation direction is defined by the spatial position of the light pixel behind the individual lens.

[0015] The display system is designed for a vehicle, e.g., a motor vehicle, and can be arranged in the interior of the vehicle. It is possible for the display system to be arranged centrally on a dashboard and / or instrument panel or on a center console and / or symmetrically to a central longitudinal axis of the vehicle.

[0016] The surface of the display panel has a flat or a curved or bent surface, e.g., convex or concave. In the case of a flat surface, a respective angle is set, provided, and / or defined relative to the flat surface. In the case of a curved surface, the angle for a respective point on the surface can be set, provided, and / or defined by taking into account a tangent plane or a tangential plane that is tangent to or touches the respective point on the surface.

[0017] The method according to the invention is designed for displaying at least one image content using a display system, for example using an embodiment of the presented display system. The display system has a display panel with a flat or curved surface and a backlight. The backlight illuminates at least one image content generated by the display panel with light that has a luminance. In a first case, only one image content is emitted by the display panel at a time in one direction perpendicular to or at an angle of 90° relative to the surface, with a light intensity of one image content having a maximum at the angle of 90°. In a second case, at least two image contents are emitted by the display panel simultaneously or at a time, each image content being emitted at an oblique angle relative to the surface.emitted, whereby a respective oblique angle relative to the surface has a value between 0° and 90°, i.e. greater than 0° and less than 90°, or a value between 90° and 180°, i.e. greater than 90° and less than 180°. Each image content has a maximum at a respective oblique angle. In the first case, when only one image content is emitted by the display panel perpendicular to the surface, the backlight sets a maximum for the luminance of the light intended for illumination at an angle of 90° relative to the surface. In the second case, when at least two image contents are emitted by the display panel at oblique angles, the backlight sets a uniform value for the luminance of the light intended for illumination relative to the surface. The light is emitted by the backlight in a switchable, directed manner.

[0018] In this method, the luminance of the backlight, for example, of a particular layer of the backlight, can be adjusted depending on the angle. In the first case, the luminance is set to a maximum perpendicular to the surface. In the second case, the luminance is set to a uniform value. If the display panel emits two different image contents at two different oblique angles, the backlight sets the uniform value for the image contents across the specified angular range.

[0019] The display system is designed to show at least one image content to at least one viewer depending on the angle. The first case described can also be referred to as public mode, in which only one common image content is shown or displayed to one viewer or several viewers. The second case, in which several image contents are emitted at different angles, can also be referred to as multi-view mode, or as dual-view mode if only two different image contents are displayed. In the second case, several different image contents can be shown to several viewers simultaneously with the one display system, with each image content being emitted at a respective acute angle from the surface to at least one viewer. In the first case, a luminance of the backlight of one or more viewers has aa single image content at an angle of 90°. In the second case, the luminance of the backlight has a uniform value for the different angle-dependent image contents.

[0020] Switching the image content between the two intended cases or modes, e.g. from public mode to multi-view mode or vice versa, is usually carried out manually or automatically depending on the at least one image content currently displayed.

[0021] If the display system is intended for a vehicle and arranged in its interior, at least one image content can be shown to at least one person as a viewer in the interior. A viewer is a driver or a front passenger in a front seat of the vehicle or an occupant in a rear seat of the vehicle. All viewers are distributed in the interior, with each viewer being able to view the at least one image content to be displayed at a specific vertical or oblique angle relative to the surface, depending on their respective position in the interior. In the first case, the common image content can be shown for at least one person, or e.g. even for several people, as viewers in the vehicle. In the second case, one image content can be shown for each viewer among several viewers, depending on the angle.A dual-view mode is provided here for one driver and one passenger.

[0022] In one embodiment of the method, it is possible to use seat occupancy sensors to determine which seat is occupied or is being occupied by a viewer, with image content being displayed for each viewer at an oblique angle in the second case. This involves detecting and / or determining whether only the driver is in the vehicle and / or whether there is a passenger in a middle rear seat. It is possible to switch automatically between the two cases, for example depending on the seat occupancy. It is also possible to switch manually between the cases by operating an input device, with a respective case being suggested accordingly. In the first case, a navigation map, for example, can be displayed as common image content. The first case can be intended for the passenger in the middle rear seat. Furthermore, in the first case, the image content can be brightly illuminated even when viewed vertically.In the second case, a separate, dynamic image can be displayed for the passenger, allowing them to watch a movie or surf the internet, for example, while the driver can be shown a separate, static image, such as information about vehicle functions and the navigation map, without distracting the driver. Different image content is displayed to the driver and the passenger simultaneously.

[0023] The display system and method can be used to implement a dual-view display panel or dual-view display with public mode. The luminance or brightness of the light from the backlight and the angle or direction at which the light is emitted to illuminate the display panel are controlled, typically automatically, depending on the at least one image content displayed by the display panel.

[0024] In one embodiment, a parallax barrier is provided for the display panel to display different image content, allowing a view of different pixels of the display panel from different angles, e.g., from the left and right. The parallax barrier is a fixed physical barrier or an upstream liquid crystal layer, which can be switched to be transparent in the first case or opaque in the second case as required. The angles, e.g., the viewing angle, of the two image contents are electronically controlled, and the backlight is also adjusted. Alternatively, the display panel can be equipped with lenticular lenses, for example, to adjust the second case.

[0025] It is understood that the features mentioned above and those to be explained below can be used not only in the combination specified in each case, but also in other combinations or on their own, without departing from the scope of the present invention.

[0026] The invention is illustrated schematically in the drawing using embodiments and is described schematically and in detail with reference to the drawing.

[0027] Fig. 1a, Fig. 1b shows a schematic representation of an embodiment of the display system according to the invention and diagrams for a luminance of the embodiment of the display system according to the invention in a first case when carrying out the embodiment of the method according to the invention.

[0028] Fig. 2a, Fig. 2b shows a schematic representation of the embodiment of the display system according to the invention and diagrams for a luminance of the embodiment of the display system according to the invention in a second case when carrying out the embodiment of the method according to the invention.

[0029] The figures are described coherently and comprehensively. The same reference symbols are assigned to the same components.

[0030] The one in every Fig. 1a, Fig. 1b, Fig. 2a and Fig. The embodiment of the display system 2 according to the invention shown in Figure 2b comprises a display panel 4 with a flat surface for displaying at least one image content and a background lighting 6 designed to backlight and / or transilluminate the display panel 4 and the at least one image content displayed thereby from behind and / or from below, wherein the display panel 4 and the background lighting 6 are arranged parallel to one another. The display system 2 is arranged in the interior of a vehicle, for example a motor vehicle, and can be viewed or observed from different positions by observers in the interior. In this case, the display system 2 is arranged centrally between a driver's seat for a driver and a passenger seat for a passenger as an observer.The driver can view the flat surface of the display panel 4 at a first angle of 90°-s1° from a first side, here the left, next to the display system 2, and the passenger can view this surface at a second angle of 90°+s2° from a second side, here the right, next to the display system 2. Alternatively, the surface of the display panel 4 can be either concavely or convexly curved.

[0031] In addition, the display system in each Fig. 1a, Fig. 1b, Fig. 2a and Fig. 2b is assigned a diagram which has an abscissa 8 and an ordinate 10. Here, 8 angles relative to the surface of the display system are plotted along the abscissa, with angles greater than 90°, here up to a maximum of 180°, being plotted along a positive section of the abscissa 8, and angles less than 90°, here down to a minimum of 0°, being plotted along a negative section of the abscissa 8. An origin of each diagram, at which the abscissa 8 and the ordinate 10 intersect perpendicularly, is provided for an angle of 90° relative to the surface. A luminance for light of the display system 2 is plotted along the ordinate 10, namely in Fig. 1b and Fig. 2b the luminance of the display panel 4 and in Fig. 1a and Fig. 2a the luminance of the backlight 6.

[0032] The Fig. 1a and Fig. 1b is intended for a first case or a public mode. Fig. 1b shows an angle-dependent curve 14 of a luminance of a single common image content emitted perpendicular to the surface of the display panel 4, wherein the luminance of the one image content has a largely constant value in an angular range between angles of approximately 90°-d1-d2° and 90°+d1+d2°.

[0033] Fig. 1a shows that for a luminance of light or for a curve 12 of the luminance of the background lighting 6, in the first case, a first angle-dependent value, i.e. a maximum or maximum value at 90°, and starting from 90° towards 90-d1° or 90°+d1° a value which decreases slightly compared to the maximum is set for a luminance of light or for a curve 12 of the luminance of the background lighting 6, and in a second wide angular range between 90°-d1°-d2° and 90°-d1° and between 90°+d1° and 90°+d1°+d2° a second angle-dependent value which decreases further starting from the maximum is set or is set for the luminance of the background lighting 6, where d1 is generally smaller than d2. In this case, light from the background illumination 6 is radiated or emitted in a directed manner at least in the angular range between 90°-d1° and 90°-d1-d2° and in the angular range 90°+d1 and 90°+d1+d2.

[0034] In the first case, the public mode is implemented with the display system 2, whereby the same common image content with the same resolution is displayed for a driver and a passenger as observer on the display panel 4. Fig. 1b is emitted. The display panel 4 and the image content emitted by it are illuminated, backlit, and / or illuminated by light from the backlight 6. In this case, the brightness of the combined image content can be increased when viewed vertically, and a decrease in brightness when viewed vertically at an angle of 90° can be reduced.

[0035] The Fig. 2a and Fig. 2b are provided for a second case or a two-view mode, wherein a first image content is set for the driver and a second image content for the passenger on the display panel 4, wherein the first image content has a luminance with a first curve 18 and the second image content has a luminance with a second curve 20. The first curve 18 for the first image content has a maximum at an angle of 90°-s1° relative to the surface. Furthermore, the second curve 20 for the second image content has a maximum at an angle of 90°+s2° relative to the surface, wherein s1 = s2, wherein the two different image contents are emitted symmetrically to the observer with respect to a plane of symmetry running perpendicular to the surface of the display panel 4. A third curve 22 in the diagram from Fig. 2b shows a superposition of the luminances of the two gradients 18, 20 of the different image contents.

[0036] In addition, Fig. 2a, that for a luminance of light from the backlight in the second case, a largely uniform and / or constant value is set in a central angular range between 90°-s1° and 90°+s2°, wherein light from the backlight 6 is radiated or emitted uniformly and / or in a wide range. The two different image contents of the display panel 4 are illuminated, backlit, and / or illuminated by the light from the backlight 6.

[0037] In the embodiment of the method with the display system 2, in the first case or in public mode, the single common image content remains bright over a larger angular range due to the directed radiation of the light from the background lighting 6. The display system 2 behaves similarly to a conventional screen or display for a viewer from different angles relative to the surface. In this case, an occupant or passenger, as a viewer in a middle seat of a rear seat bench behind the driver's seat and the front passenger seat, can also see the image content as on the conventional screen, with the brightness of the image content remaining sufficiently constant even when the viewer in the rear seat bench moves his head sideways.If the driver is alone and therefore there is no passenger in the vehicle, the display system 2 can also be switched to public mode, as this reduces a drop in the brightness of the image content when the driver, as the viewer, moves his head sideways.

[0038] Depending on at least one image content to be displayed in a respective case, i.e. only the one common image content for both sides next to the display system 2 in the first case or the two different image contents in the second case, i.e. one image content each for each side next to the display system 2, the drop in brightness for a vertical view of the surface at an angle of 90°, e.g., for the viewer in the middle seat, can be reduced by the backlight 6. The backlight 6 or a backlight for the display panel 4, which here comprises liquid crystals and / or liquid crystal cells (LC cells) and can be referred to as a liquid crystal or LC display, has a technology for switchably influencing a radiation characteristic of the light emitted by the backlight 6 or its luminance.

[0039] Both light-shading liquid crystal cells and light-scattering liquid crystal cells can be used. Angle-dependent attenuation and / or scattering of the light is / are used in a respective liquid crystal cell or in the liquid crystalline material, with the light being emitted or radiated by the backlight 6 in a directed or broadly distributed manner. REFERENCE SYMBOL: 2 Display system 4 Display field 6 Backlight 8 Abscissa 10 Ordinates 12 History 14 History 16 History 18, 20, 22 Course QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] US 8 936 373 B2

[0002] US 2011 / 018860 A1

[0003] EP 847 208 A2

[0004]

Claims

[1] Display system comprising a display panel (4) with a surface and a backlight (6) configured to illuminate at least one image content generated by the display panel (4) with light having a luminance, wherein the display panel (4) is configured to emit, in a first case, only one image content at an angle of 90° relative to the surface, and in a second case, at least two image contents, each image content at an oblique angle relative to the surface, wherein the backlight (6) is configured in the first case to set a maximum for the luminance of the light at the angle of 90° relative to the surface, and wherein the backlight (6) is configured in the second case to set a uniform angular range for the luminance of the light relative to the surface in an angular range comprising the oblique angles. [2] Display system according to claim 1, wherein the backlight (6) is designed in the first case to set a first value for the luminance in a first central angular range between 90°-d1° and 90°+d1° and a second value in a second angular range between 90°-d1°-d2° and 90°-d1° and between 90°+d1° and 90°+d1°+d2°, wherein the first value is greater than the second value, and wherein d1 is less than d2. [3] Display system according to claim 1 or 2, wherein the backlight (6) has two layers, wherein a first layer is designed to produce a directional radiation characteristic for the luminance perpendicular to the surface, and wherein a second layer is designed to produce a broad radiation characteristic for the luminance. [4] Display system according to claim 3, wherein only in the first case the first layer is to be activated, wherein in the first case the second layer is optionally also to be activated, and wherein in the second case only the second layer is to be activated. [5] Display system according to one of the preceding claims, wherein the backlight (6) comprises a light control film, liquid crystals, electrophoretic particles, refractive optics, light field emitters and / or diffractive optics. [6] Display system according to one of the preceding claims for a vehicle. [7] Display system according to one of the preceding claims, wherein the surface of the display panel (4) has a flat or a curved surface. [8] Method for displaying at least one image content with a display system (2), wherein the display system (2) has a display panel (4) with a surface and a backlight (6) with which at least one image content generated by the display panel (4) is illuminated with light having a luminance, wherein in a first case only one image content is emitted by the display panel (4) in only one direction at an angle of 90° relative to the surface, and in a second case at least two image contents are emitted, each image content being emitted at an oblique angle relative to the surface, wherein in the first case a maximum is set by the backlight (6) for the luminance of the light at the angle of 90° relative to the surface, and wherein in the second case a uniform value is set by the backlight (6) for the luminance relative to the surface in an angular range comprising the oblique angles.

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