Display device and vehicle

Abstract

The invention relates to a display device (1) and a vehicle having such a display device (1). A display device (1) includes a display panel and a backlight (3) for the display panel. The backlight (3) comprises a reflector (30) having a plurality of cavities (31) in reflective configuration. In addition, the backlight (3) comprises a plurality of light sources (32) arranged in the cavities (31), respectively. The walls (310) of the cavities (31) are configured such that the lattice structure of the reflector (30) resulting from the arrangement of the cavities (31) is broken.

Description

Technical Field

[0001] The invention relates to a display device and a vehicle having the display device. Background Art

[0002] The number and area of ​​display devices in vehicles are constantly increasing. Display devices can be found on the market, for example, as instrument panels for the driver, central displays, and displays for the front passengers. Non-luminous transmissive display devices require a backlight to present the image. Here, the task of the backlight is to illuminate the entire active surface of the display panel used as evenly as possible in order to produce a display that is as even as possible even in the peripheral area.

[0003] A matrix backlight generates light using a large number of light sources arranged in a matrix. The light from the light sources is redirected in the direction of the display panel with the help of a reflector.

[0004] For example, US2020 / 0287109 A1 describes a backlight for a display panel. The backlight includes a reflector having a plurality of regularly shaped reflective cavities arranged in a grid. The height of the reflector decreases toward the corners of the cavity.

[0005] DE 10 2007 007 353 A1 describes a lighting device with a light emitting surface that can be assembled in a modular manner from a plurality of radiation reflectors. Preferably, radiation reflectors in the form of honeycombs, scales, triangles or rectangles are used. Each of the radiation reflectors comprises a plurality of radiation reflecting surfaces that are curved outwards from a center where the light source is arranged.

[0006] In practice, it has been found that currently available backlights achieve relatively uniform illumination of the display panel, but leave a grid structure in the illumination that is discernible to the human eye. These are perceived by the observer as annoying. Summary of the invention

[0007] It is an object of the present invention to provide an improved display device having a matrix backlight.

[0008] This object is achieved by a display device having the features of claim 1 and by a vehicle according to claim 10. Preferred configurations of the invention are subject matter of the dependent claims.

[0009] According to a first aspect of the present invention, a display device includes a display panel and a backlight for the display panel, the backlight including:

[0010] a reflector having a plurality of reflectively arranged cavities, the walls of which are arranged in such a way that the grid structure of the reflector resulting from the arrangement of the cavities is broken; and

[0011] - A plurality of light sources respectively arranged in the cavities.

[0012] In the solution according to the present invention, a reflector is arranged between the light source and the display panel, and fills the gap caused by design between the light source and the display panel or another optical component arranged below the display panel. This reflector includes a plurality of reflective cavities, each of which is arranged with at least one light source. These cavities direct the light emitted from the light source toward the display panel. The wall of the cavity is configured so that an observer of the display device cannot recognize the regular grid structure of the reflector. To achieve this, the wall of the cavity or the upper edge of the cavity seen by the observer is configured so that long, intersecting straight lines are avoided. As a result, the human eye cannot adjust the lines to form annoying long straight lines. Many technologies can be used for the production of reflectors. For example, the reflector can be implemented as a plastic part, a silicone part or a formed film produced by injection molding.

[0013] According to one aspect of the invention, adjacent cavities each have a different configuration. In this embodiment, adjacent cavities each have a different shape. In processing, multiple cavities (e.g., 2×2 cavities) can be formed into a block. The reflector can then include multiple such blocks. This reduces the required expenditure associated with the reflector design.

[0014] According to one aspect of the invention, the upper edge of the cavity seen by the observer forms an irregular polygon. In this embodiment, the cavity is formed by a polygon (e.g., by a pentagon), thereby avoiding continuous or long straight lines by design. Although the upper edge of the cavity has a large number of straight sections here, and these sections may also extend over more than one cavity, these sections are not perceived by the observer's eyes as continuous straight lines.

[0015] According to one aspect of the invention, the upper edge of the cavity seen by the observer has a curved profile. As a result of this curved profile, straight lines perceptible to the eye can be completely avoided.

[0016] According to one aspect of the invention, the cavities are nested within each other. Figure 1 The advantages are that all cavities can have the same shape, except perhaps for the edge regions of the reflectors, but adjusting the upper edges of the cavities to form lines or grids is very difficult for the human eye.

[0017] According to one aspect of the present invention, the light sources have a regular arrangement. The regular arrangement of the light sources (e.g., in a regular matrix or in a plurality of regular lines) facilitates the design of a printed circuit board on which the light sources are arranged. In addition, it facilitates the calculation of control signals of the light sources required for uniform illumination of the display panel.

[0018] According to one aspect of the invention, the walls of the cavity are rounded and the cavity is configured to reflect light emitted from the light source towards the display panel. Due to the rounding, the emitted light can be reflected towards the display panel in a more targeted manner.

[0019] According to one aspect of the invention, the light source is a side-emitting light emitting diode. Using a side-emitting light emitting diode has the advantage of preventing the formation of light spots in the backlight. This ensures that the illumination of the display panel appears particularly uniform.

[0020] According to one aspect of the invention, the side-emitting light emitting diodes emit light from all sides. This ensures that the uniformity of the illumination of the display panel is additionally improved.

[0021] The display device according to the invention is preferably used in a vehicle. For example, the vehicle may be a motor vehicle, but alternatively may also be an aircraft, a rail vehicle or a watercraft. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Further features of the present invention will become apparent from the following description and appended claims, taken in conjunction with the accompanying drawings.

[0023] Figure 1 schematically shows a cross section of a display device;

[0024] Figure 2 schematically shows a detailed view of a display device;

[0025] Figure 3 A reflector of a known display device is schematically shown;

[0026] Figure 4 A first embodiment of a reflector for a display device according to the present invention is schematically shown;

[0027] Figure 5 A second embodiment of a reflector for a display device according to the present invention is schematically shown;

[0028] Figure 6 A third embodiment of a reflector for a display device according to the present invention is schematically shown;

[0029] Figure 7 A fourth embodiment of a reflector for a display device according to the present invention is schematically shown; and

[0030] Figure 8A vehicle utilizing a display device according to the invention is schematically shown. DETAILED DESCRIPTION

[0031] In order to better understand the principles of the invention, embodiments of the invention are explained in more detail below with reference to the accompanying drawings. In the drawings, the same reference numerals are used for identical or functionally identical elements and do not have to be described again for each drawing. It goes without saying that the invention is not limited to the embodiments represented and that the features described may also be combined or modified without departing from the scope of protection of the invention defined in the appended claims.

[0032] Figure 1 A cross section of a display device 1 is schematically shown. The display device 1 includes a display panel 2, which is adhesively bonded to a cover glass 4. The cover glass 4 closes a housing 8 of the display device 1 relative to the environment. A backlight 3 for the display panel 2 is arranged in another housing 7. The backlight 3 includes a reflector 30 having a plurality of cavities 31. The walls 310 of the cavities 31 or the upper edges 311 of the cavities 31 seen by an observer are configured so that long, intersecting straight lines are avoided, and an observer of the display device 1 cannot recognize the regular grid structure of the reflector 30. One light source 32 (typically a light emitting diode) is arranged in each of these cavities 31. The light source 32 is arranged on a printed circuit board 33, which can be adhesively bonded to the housing 7 of the backlight 3. In the example shown, an optical plate 5 is located between the backlight 3 and the display panel 2, on which an optical film stack 6 is arranged. The film of the optical film stack 6 is intended to scatter, collect or guide the light from the reflector 30 so as to meet the requirements of the solid angle of the backlight 3. Typical films for light orientation are brightness enhancement film (BEF) and light control film (LCF). The optical plate 5 is a transparent plate that ensures the optical distance between the optical film stack 6 and the light source 32. The cover glass 4, the optical plate 5, and the housing 7 of the backlight 3 are connected to each other by a suitable connecting element 9 (e.g., an adhesive).

[0033] Figure 2A detailed view of a display device 1 is schematically shown. It shows a cover glass 4 with a display panel 2, an optical plate 5 with an optical film stack 6, and a backlight 3 with a housing 7, a printed circuit board 33 (on which a light source 32 is arranged), and a reflector 30. In this case, the light source 32 is a side-emitting light-emitting diode, preferably, these side-emitting light-emitting diodes emit light L on all sides. The reflective wall 310 of the cavity 31 of the reflector 30 has a rounded configuration and directs the light L emitted from the light source 32 toward the display panel 2. In an exemplary configuration, the overall structural height of the display device 1 is preferably in the range of 13.3 mm. The height of the reflector 30 can be 3.72 mm, and the width of the widest part of the wall 33 can be 6.13 mm. The distance between the film stack 6 and the display panel 2 is, for example, 1.31 mm; the distance between the reflector 30 and the optical plate 5 can be 1.05 mm. The distance between the light sources 32 can be, for example, 9.13 mm.

[0034] Figure 3 A reflector 30 of a known display device is schematically shown. The reflector 30 comprises a plurality of cavities 31, in each of which a light source 32 is arranged. The cavities 31 have a regular shape and are arranged in a regular grid. The walls 310 of the cavities 31 or the upper edges 311 of the cavities 31 form a square in each case. A regular grid structure consisting of long, intersecting lines emerges from the arrangement and shape of the cavities 31. This grid structure is perceived by an observer as annoying.

[0035] Figure 4 A first embodiment of a reflector 30 of a display device according to the present invention is schematically shown. In this embodiment, adjacent cavities 31 each have a different configuration. This breaks the regular grid structure of the reflector 30; that is, an observer of the display device cannot recognize the regular grid structure. In the depicted example, the upper edges 311 of the cavities 31 seen by the observer form an irregular polygon, in this case an irregular pentagon. Although straight lines appear, these straight lines extend here to no more than two cavities 31. Every four cavities 31 form a block 34; the blocks are indicated here by dotted lines. The reflector 30 includes a plurality of such blocks 34. It can be easily recognized that the light sources 32 have a regular arrangement. In this case, the light sources 32 are arranged in a regular lattice.

[0036] Figure 5A second embodiment of a reflector 30 of a display device according to the invention is schematically shown. In this embodiment, adjacent cavities 31 also each have a different configuration. In the depicted example, the upper edge 311 of the cavity 31 seen by the observer forms an irregular hexagon. Although straight lines appear, these straight lines extend here to no more than one cavity 31. Every two cavities 31 form a block 34; the blocks are indicated here by dotted lines. Again, the light sources 32 have a regular arrangement. However, in this case, the light sources 32 are not arranged in a regular matrix; instead, the light sources are arranged in a plurality of regular lines.

[0037] Figure 6 A third embodiment of a reflector 30 of a display device according to the invention is schematically shown. As previously described, adjacent cavities 31 each have a different configuration. The upper edges 311 of the cavities 31 seen by the observer form an irregular pentagon in each case, wherein every four cavities 31 form a block. Again, the light sources 32 have a regular arrangement in a plurality of regular lines.

[0038] Figure 7 A fourth embodiment of a reflector 30 for a display device according to the invention is schematically shown. In this embodiment, the upper edge 311 of the cavity 31 seen by the observer has a curved profile. In this case, the cavity 31 is like a mosaic. Figure 1 In this example, all cavities 31 have the same shape, except for the edge region of the reflector 30. In addition, the light sources 32 are arranged in a regular grid. However, since no straight lines appear, the regular grid structure of the reflector 30 is also broken in this case.

[0039] Figure 8 A vehicle 100 utilizing a display device 1 according to the present invention is schematically shown. In this embodiment, the vehicle 100 is a motor vehicle. The motor vehicle comprises a display device 1 according to the present invention, which is arranged in a dashboard. Data about the vehicle's surroundings can be acquired by a sensor system 101. The sensor system 101 can particularly comprise a surroundings recognition sensor, such as an ultrasonic sensor, a laser scanner, a radar sensor, a lidar sensor or a camera. The information acquired by the sensor system 101 can be used to generate content to be displayed by the display device 1. In this example, other parts of the motor vehicle are a navigation system 102 and a data transmission unit 103, by which position information can be provided. By way of example, a connection can be established with the background by means of the data transmission unit 103, for example, for receiving software updates of components of the motor vehicle. There is a memory 104 to store data. Data exchange between the various components of the motor vehicle is carried out via a network 105.

[0040] List of reference numerals:

[0041] 1 Display device

[0042] 2 Display Panel

[0043] 3 Backlight

[0044] 30 Reflector

[0045] 31 Cavity

[0046] 310 wall

[0047] 311 Top edge

[0048] 32 Light Source

[0049] 33 Printed Circuit Board

[0050] 34 pieces

[0051] 4 Cover glass

[0052] 5 Optical plate

[0053] 6 Membrane stack

[0054] 7 Backlight housing

[0055] 8 Display device housing

[0056] 9 Connecting elements

[0057] 100 Transportation

[0058] 101 Sensor System

[0059] 102 Navigation System

[0060] 103 Data Transmission Unit

[0061] 104 Memory

[0062] 105 Network

[0063] L Light

Claims

1. A display device (1), comprising a display panel (2) and a backlight (3) for the display panel (2), the backlight (3) comprising: - a reflector (30) having a plurality of cavities (31) arranged in a reflective manner, wherein the walls (310) of the cavities (31) are arranged in such a way that the grid structure of the reflector (30) resulting from the arrangement of the cavities (31) is broken; and - A plurality of light sources (32) which are respectively arranged in the cavities (31).

2. The display device (1) according to claim 1, characterized in that Adjacent cavities (31) each have a different configuration.

3. The display device (1) according to claim 1 or 2, characterized in that: The upper edges (311) of these cavities (31) viewed by an observer form an irregular polygon.

4. The display device (1) according to claim 1 or 2, characterized in that: The upper edges ( 311 ) of the cavities ( 31 ) seen by the observer have a curved contour.

5. The display device (1) according to claim 4, characterized in that These cavities (31) are nested within each other.

6. The display device (1) according to any one of the preceding claims, characterized in that The light sources (32) have a regular arrangement.

7. The display device (1) according to any one of the preceding claims, characterized in that The walls (310) of the cavities (31) are rounded, and the cavities (31) are configured to reflect light (L) emitted from the light sources (32) toward the display panel (2).

8. The display device (1) according to claim 7, characterized in that The light sources (32) are side-emitting light emitting diodes.

9. The display device (1) according to claim 7, characterized in that These side-emitting light-emitting diodes emit light (L) on all sides.

10. A vehicle (100) having a display device (1) as claimed in any one of the preceding claims.

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