DISPLAY DEVICE AND MEANS OF MOTION

Description

[0001] The present invention relates to a display device and a means of transport with such a display device.

[0002] Display devices in vehicle interiors are located directly in front of the vehicle occupants and are therefore always exposed to the risk of head impact. A new product must therefore pass a certified head impact test before it can be used.

[0003] A display device is at increased risk of failing such a test if the display's cover glass shatters during the test. To prevent this, the display's cover glass or display panel is supported as extensively and as early as possible. To achieve this, the distances between the components within the display device must be kept as small as possible. Minimizing gaps within the display device places increased demands on the precision of both the manufacturing of the individual parts and the assembly.

[0004] In this context, US 2006 / 0203480 A1 describes a backlight comprising a plurality of lamps for generating light, a diffuser, a housing, and a first support element. The diffuser is arranged above the lamps and diffuses the light. The housing has a bottom portion and a sidewall portion extending from the bottom portion to create a receiving space for the lamps. The first support element is arranged on the bottom portion to support the diffuser and has two mutually inclined portions, which make it possible to reduce the impact forces transmitted from the diffuser to the bottom portion.

[0005] Matrix backlights utilize a multitude of light sources arranged in a matrix to generate light. However, this requires a greater distance between the light sources and the display panel to homogenize the light. This greater distance makes it more difficult to provide even and early support for the display panel, thus making it difficult to pass the head impact test.

[0006] Against this background, CN 103742840 A describes a backlight comprising a hollow body in which light-emitting diodes are arranged, and an optical plate arranged on the hollow body. The side walls of the hollow body are reflective. Support columns for supporting the optical plate are arranged within the hollow body.

[0007] US 2020 / 0292885 A1 describes a display with a backlight. The backlight comprises an array of cells. Each cell contains a light source and a cavity reflector that reflects light from the light source through a diffuser. The light sources are mounted on a printed circuit board. Support posts on the printed circuit board hold the diffuser at a fixed distance from the printed circuit board.

[0008] US 2011 / 0304798 A1 describes a lighting device having first partition walls separating a plurality of light-emitting regions, light sources arranged in the respective light-emitting regions, second partition walls higher than the first partition walls and enclosing the plurality of light-emitting regions, and optical means for scattering the light emitted by the light sources, wherein the optical means are supported by the second partition walls and by additional support elements.

[0009] It is an object of the invention to provide an improved display device with a matrix backlight.

[0010] This object is achieved by a display device having the features of claim 1 and by a means of transport according to claim 10. Preferred embodiments of the invention are the subject of the dependent claims.

[0011] According to a first aspect of the invention, a display device comprises a display panel and a backlight for the display panel, the backlight comprising: a reflector having a plurality of reflective cavities; a plurality of light sources arranged in each of the cavities; and support elements that are transparent to light emitted by the light sources, are supported on a circuit board on which the light sources are arranged, and extend at least partially into a gap between the cavities and an optical component arranged below the display panel, wherein the support elements are embedded in walls of the cavities.

[0012] In the solution according to the invention, a reflector is arranged between the light sources and the display panel, filling the design-related gap between the light sources and the display panel or another optical component arranged below the display panel. This reflector has a plurality of reflective cavities, each of which contains a light source. The cavities orient the light emerging from the light sources toward the display panel. Additional support elements prevent breakage of the display panel or the cover glass. The use of support elements makes it possible to use different materials for the support elements and the reflector. Since the support elements protrude from the cavities, the walls of the cavities do not reach as far as the display panel or the other optical component.Otherwise, this could lead to unlit areas and thus a visible grid structure. The support elements are transparent and therefore do not affect the homogeneity of the illumination.

[0013] According to the invention, the support elements are embedded in the walls of the cavities. This design of the reflector allows it to absorb energy. The support elements can be embedded in the walls, for example, using press-fit technology or hot-staking. The entire surface of the backlight is not necessarily provided with support elements. Local positioning is also possible, for example, limited to edge areas or a central area of ​​the display panel. By varying the wall thicknesses or heights, the energy absorption of the reflector can be adjusted and thus matched to the display device.

[0014] According to the invention, the support elements rest on a circuit board on which the light sources are arranged. In this way, the support elements can also be used to stiffen the reflector. The support elements can be glued to the circuit board, for example, as columns.

[0015] According to one aspect of the invention, the walls of the cavities are rounded, and the cavities are designed to reflect the light emitted by the light sources toward the display panel. This rounding allows the emitted light to be reflected more precisely toward the display panel. At the same time, the rounding ensures increased buckling strength and a reduced notch effect in the direction of impact in the event of a head impact.

[0016] According to one aspect of the invention, the light sources are side-emitting LEDs. The use of side-emitting LEDs has the advantage of preventing the formation of light spots in the backlight. This ensures a particularly homogeneous illumination of the display panel.

[0017] According to one aspect of the invention, the side-emitting LEDs emit light from all sides. This further increases the homogeneity of the display panel's illumination.

[0018] According to one aspect of the invention, a gap is located between the support elements and a component to be supported by the support elements. Such a gap has the advantage of enabling tolerance compensation of the individual parts and compensation for temperature expansion without generating additional stress in the height structure. Furthermore, the gap can serve to mix the light in the individual cavities to ensure homogeneous illumination. The component to be supported can be, for example, the display panel or an optical plate arranged between the reflector and the display panel.

[0019] According to one aspect of the invention, the cavities form a rectangular grid or a hexagonal grid. The reflector can be configured in various ways. Both the arrangement of the cavities in a rectangular grid and the arrangement of the cavities in a hexagonal grid allow the reflector to be formed from a gapless matrix of cavities.

[0020] According to one aspect of the invention, the support elements are made of polycarbonate or polymethyl methacrylate. These materials have the advantage of exhibiting the desired transparency while being cost-effective and easy to process.

[0021] A display device according to the invention is preferably used in a means of transport. The means of transport may be, for example, a motor vehicle, but alternatively also an aircraft, a rail vehicle, or a watercraft.

[0022] Further features of the present invention will become apparent from the following description and the appended claims taken in conjunction with the figures. Figure overview

[0023] Fig. 1 schematically shows a section of a display device according to the invention; Fig. 2 schematically shows a detailed view of a display device according to the invention; Fig. 3 schematically shows an embodiment of a support element; Fig. 4 schematically shows a further embodiment of a support element; Fig. 5 schematically shows an embodiment of a support element according to the invention; Fig. 6 schematically shows a further embodiment of a support element; Fig. 7 schematically shows a reflector in which a rectangular grid is formed; Fig. 8 schematically shows a reflector in which a hexagonal grid is formed; and Fig. 9 schematically shows a means of transport that uses a display device according to the invention. Character description

[0024] To better understand the principles of the present invention, embodiments of the invention are explained in more detail below with reference to the figures. Like reference numerals are used in the figures for like or equivalent elements and are not necessarily described again for each figure. It is understood that the invention is not limited to the illustrated embodiments and that the described features can also be combined or modified without departing from the scope of the invention as defined in the appended claims.

[0025] Fig. 1 shows a schematic view of a section of a display device 1 according to the invention. The display device 1 has a display panel 2 which is glued to a cover glass 4. The cover glass 4 closes off a housing 8 of the display device 1 from the environment. A backlight 3 for the display panel 2 is arranged in a further housing 7. The backlight 3 has a reflector 30 with a plurality of cavities 31. A light source 32, typically a light-emitting diode, is arranged in each of the cavities 31. The light sources 32 are arranged on a circuit board 35, which can be glued to the housing 7 of the backlight 3. Additional support elements 33 prevent the display panel 2 or the cover glass 4 from breaking in the event of a head impact. The support elements 33 are transparent to the light emitted by the light sources 32 and protrude from the cavities 31.In the example shown, an optical plate 5 with a film stack 6 arranged thereon is located between the backlight 3 and the display panel 2. The films of the optical film stack 6 have the task of scattering, collecting, or directing the light from the reflector 30 in such a way that the requirements for the solid angle of the backlight 3 are met. Typical films for light alignment are brightness enhancement films (BEF) and light control films (LCF). The optical plate 5 is a transparent plate that ensures the optical distance between the optical film stack 6 and the light sources 32. The cover glass 4, the optical plate 5, and the housing 7 of the backlight 3 are connected to one another by suitable connecting elements 10, e.g., adhesives. A gap 9 is located between the film stack 6 and the display panel 2.A further gap 9' is located between the optical plate 5 and the cavities 31. The gap 9 between the display panel 2 and the optical plate 5 with the foil stack 6 arranged thereon is so narrow that the cover glass 4 does not break when it is deformed to the extent that it has reduced this gap 9 to zero. Upon further deformation, the cover glass 4 comes into contact with the support elements 33 via the optical plate 5 and the foil stack 6 and is supported by them in such a way that it does not bend further but is supported by the parts underneath.

[0026] Fig. 2 shows a schematic detail view of a display device 1 according to the invention. The cover glass 4 with the display panel 2, the optical plate 5 with the foil stack 6 and the background lighting 3 with the housing 7, the circuit board 35 with the light sources 32 arranged thereon and the reflector 30 can be seen. The light sources 32 are laterally emitting light diodes, which preferably emit light L from all sides. The reflective walls 34 of the cavities 31 of the reflector 30 are rounded and orient the light L emerging from the light sources 32 in the direction of the display panel 2. At the same time, the rounding ensures increased buckling strength or a lower notch effect in the direction of impact in the event of a head impact. The transparent support elements 33 allow the light L to pass through, apart from a Fig. 2 refraction not shown, pass through unhindered. Suitable materials for the support elements 33 are, for example, polycarbonate or polymethyl methacrylate. In an exemplary embodiment, the total structural height of the display device is preferably in the range of ~13.3 mm. The height of the reflector 30 can be ~3.72 mm, the width of the walls 34 at their widest point ~6.13 mm. The gap 9 between the film stack 6 and the display panel 2 has a height of ~1.31 mm, the gap 9' between the reflector 30 and the optical plate 5 has a height of ~1.05 mm. The distance between the light sources 32 can be, for example, ~9.13 mm. By varying the wall thicknesses or wall heights, the energy absorption of the reflector 30 can be adjusted and thus matched to the display device 1.

[0027] Fig. 3 shows a schematic of an embodiment of a support element 33. It shows the optical plate 5 with the film stack 6 and the backlight 3 with the housing 7, the circuit board 35 with the light sources 32 arranged thereon, and the reflector 30. In this embodiment, the transparent support element 33 is placed on a wall 34 of the cavities 31 and extends as far as the optical plate 5. However, there may also be a gap between the support element 33 and the optical plate 5 instead. The support element 33 can, for example, be manufactured by means of two-component injection molding or glued to the reflector.

[0028] Fig. 4 shows schematically a further embodiment of a support element 33. The figures show the optical plate 5 with the film stack 6 and the background lighting 3 with the housing 7, the circuit board 35 with the light sources 32 arranged thereon and the reflector 30. In this embodiment, the transparent support element 33 is embedded in a wall 34 of the cavities 31. There is a gap 36 between the support element 33 and the optical plate 5. Alternatively, the support element 33 can reach up to the optical plate 5. The support element 33 can be embedded in the wall 34, for example, using a press-fit technique or hot caulking.

[0029] Fig. 5 shows schematically an embodiment of a support element 33 according to the invention. The figures show the optical plate 5 with the film stack 6 and the background lighting 3 with the housing 7, the printed circuit board 35 with the light sources 32 arranged thereon and the reflector 30. In this embodiment, the transparent support element 33 is embedded in a wall 34 of the cavities 31, but it rests on the printed circuit board 35. In this way, the support elements 33 can additionally be used to stiffen the reflector 30. There is a gap 36 between the support element 33 and the optical plate 5. Alternatively, the support element 33 can reach up to the optical plate 5. The support element 33 can, for example, be glued to the printed circuit board 35 as a column.

[0030] Fig. 6 schematically shows a further embodiment of a support element 33. The optical plate 5 with the foil stack 6 and the backlight 3 with the housing 7, the circuit board 35 with the light sources 32 arranged thereon and the reflector 30 are shown. However, in this embodiment, the transparent support element 33 is an integral part of the optical plate 5.

[0031] Fig. 7 shows a schematic of a reflector 30 in which a rectangular grid is formed. The arrangement of the cavities 31 and light sources 32 in a rectangular grid allows the reflector 30 to be formed from a continuous matrix of cavities 31. The entire surface of the backlight is not necessarily provided with support elements 33. Local positioning is also possible, e.g., limited to edge areas or a central area relative to the display panel.

[0032] Fig. 8 shows a schematic representation of a reflector 30 in which a hexagonal grid is formed. The arrangement of the cavities 31 and light sources 32 in a hexagonal grid also allows the reflector 30 to be formed from a continuous matrix of cavities 31. In this case, too, the entire surface of the backlight is not necessarily provided with support elements 33.

[0033] Local positioning is also possible, e.g. limited to edge areas or a central area in relation to the display panel.

[0034] Fig. 9shows a schematic representation of a means of transport 20 which uses a display device 1 according to the invention. In this example, the means of transport 20 is a motor vehicle. The motor vehicle has a display device 1 according to the invention which is arranged in a dashboard. Data on the vehicle's surroundings can be acquired using a sensor system 21. The sensor system 21 can in particular comprise sensors for environmental detection, e.g., ultrasonic sensors, laser scanners, radar sensors, lidar sensors, or cameras. The information acquired by the sensor system 21 can be used to generate content to be displayed for the display device 1. Further components of the motor vehicle in this example are a navigation system 22, by means of which position information can be provided, and a data transmission unit 23. By means of the data transmission unit 23, for example,A connection to a backend can be established, for example, to obtain updated software for components of the motor vehicle. A memory 24 is provided for storing data. Data exchange between the various components of the motor vehicle takes place via a network 25. List of reference symbols

[0035] 1Display device 2Display panel 3Backlight 30Reflector 31Cavity 32Light source 33Support element 34Wall 35Printed circuit board 36Gap 4Cover glass 5Optical plate 6Foil stack 7Backlight housing 8Display device housing 9, 9'Gap 10Connecting element 20Means of transport 21Sensors 22Navigation system 23Data transmission unit 24Memory 25Network LLight

Claims

1. Display device (1) having a display panel (2) and a backlight (3) for the display panel (2), the backlight (3) comprising: - a reflector (30) with a plurality of reflectively embodied cavities (31); - a multiplicity of light sources (32) arranged in each case in the cavities (31); and - support elements (33) which are transparent to light (L) emitted by the light sources (32), are supported on a circuit board (35), have the light sources (32) arranged thereon, and protrude at least partially into a gap (9') between the cavities (31) and an optical component (5) arranged below the display panel (2); characterized in that the support elements (33) are embedded in walls (34) of the cavities (31).

2. Display device (1) according to Claim 1, wherein the support elements (33) are embedded in the walls (34) of the cavities (31) by means of a press-in technique or heat staking.

3. Display device (1) according to Claim 1 or 2, wherein the backlight (3) has support elements (33) only in peripheral regions or in a central region of the display panel (2).

4. Display device (1) according to one of the preceding claims, wherein walls (34) of the cavities (31) are rounded and the cavities (31) are designed to reflect the light (L), emitted by the light sources (32), in the direction of the display panel (2).

5. Display device (1) according to Claim 4, wherein the light sources (32) are side-emitting light-emitting diodes.

6. Display device (1) according to Claim 5, wherein the side-emitting light-emitting diodes emit light (L) on all sides.

7. Display device (1) according to one of the preceding claims, wherein a gap (36) is located between the support elements (33) and a component (2, 5) to be supported by the support elements (33).

8. Display device (1) according to one of the preceding claims, wherein the cavities (31) form a rectangular grid or a hexagonal grid.

9. Display device (1) according to one of the preceding claims, wherein the support elements (33) are made of polycarbonate or polymethyl methacrylate.

10. Transportation means (20) having a display device (1) according to one of the preceding claims.