Display device and means of transport

Abstract

The present invention relates to a display device (10) and a means of locomotion (800) with such a display device (10). The display device (10) comprises a display panel (100) and a backlight (210) for the display panel (100). The backlight (210) comprises a circuit board with a plurality of light sources (230) arranged on the circuit board (220), each of the light sources (230) being associated with a lens, and the lens (250, 250') enclosing the light source (230). The lens (250, 250') has a continuous axial recess (253) in which the light source (230) is arranged. A surface of a top (251, 251') of the lens (250, 250') has a surface structure (S), wherein the surface structure (S) changes in its spatial orientation.

Description

[0001] The present invention relates to a display device comprising a display panel and a backlight for the display panel, as well as a means of transportation with such a display device. Such display devices are used today in almost every means of transportation, for example, a motor vehicle.

[0002] The number and size of display devices in vehicles are constantly increasing. Display devices can be found, for example, as instrument clusters for the driver, central displays, and passenger displays. Non-self-illuminating transmissive displays require backlighting for image display. The purpose of the backlighting is to illuminate the display panel as evenly as possible across its entire active area, in order to create a homogeneous display right to the edges.

[0003] Matrix backlights utilize a multitude of light sources arranged in a matrix to generate light. A reflector directs the light from these sources towards the display panel.

[0004] Display devices with a display panel and a backlight for the display panel in various embodiments are known to those skilled in the art. For example, DE 10 2022 205 566 A1 describes such a display device and a means of transport with such a display device. The display device has a display panel and a backlight for the display panel. The backlight comprises a reflector consisting of a plurality of reflector elements with a plurality of reflectively designed cavities and a plurality of light sources arranged in each of the cavities.

[0005] US 2005 / 0276069 A1 describes a liquid crystal display with a diffusion plate or prism plate positioned between a liquid crystal panel and a plurality of light-emitting sections. Each light-emitting section is formed by an optical conductor and one or more light-emitting devices. The optical conductor has a light-reflecting surface formed in a substrate and a light-transmitting surface that is brought into close contact with the light-reflecting surface.

[0006] DE 10 2007 007 353 A1 describes a lighting device with a luminous surface that can be assembled modularly from a plurality of radiation reflectors. Preferably, honeycomb-shaped, scale-shaped, triangular, or rectangular radiation reflectors are used. Each of the radiation reflectors has several radiation-reflecting surfaces that curve outwards from a center in which a light source is arranged.

[0007] Furthermore, EP 4 099 050 A1 describes, for example, an optical element with a light-transmitting support and at least one microstructure formed on at least a part of a first side of the support.

[0008] DE 102 26 471 A1 describes an optical lens with an imprinted, wave-like fine structure on its optically active surface. A wave-like microstructure is imprinted over this fine structure.

[0009] As the size of the display increases, so does the size of the backlight, along with the number of reflectors required. Such large backlights typically consist of multiple composite reflector elements, each of which is itself composed of several individual lenses. Uniform illumination of the display across the entire surface of a display panel generally necessitates a considerable height for the individual lenses of the reflector. To improve the uniformity of the illumination, additional components such as a diffuser are used. The disadvantage of this is that it increases the overall height of the backlight, particularly the reflector, thus limiting its application.Particularly flat designs with uniform, homogeneous illumination across the entire surface of the display panel are not possible or only possible to a limited extent.

[0010] The present invention is based on the objective of providing an improved display device with a backlight and a means of transport with such a display device, wherein a flat installation height of the backlight, in particular of the lens, is achieved with uniform illumination of the display device over the entire surface of the display panel.

[0011] This problem is solved according to the invention by a display device according to the preamble of independent claim 1 together with the features of the characterizing part of independent claim 1 and by a means of propulsion according to claim 12. Advantageous embodiments of the invention are the subject of the dependent claims.

[0012] The invention provides a display device with a display panel and a backlight for the display panel. The backlight comprises a printed circuit board with a plurality of light sources arranged on the circuit board, each of which is associated with a lens. The lens encloses the light source and has a continuous axial recess in which the light source is arranged. A surface of the upper surface of the lens has a surface structure, the surface structure of which changes along its course.

[0013] The backlight, located between the housing and the display panel, has a modular design. It comprises a circuit board with integrated light sources and a reflector, which consists of several reflector elements. Each reflector element, in turn, consists of several lenses, preferably made of plastic, such as a crystal-clear material like polycarbonate or PMMA, optionally with added fillers to optimize optical properties, or of glass. Materials with varying degrees of optical diffusion are used.

[0014] The use of reflector elements has the advantage that the reflector is composed of smaller elements that are easier to manufacture and handle. The required production tools are also smaller. Furthermore, the reflector elements can be used for differently designed display devices, which is generally not possible with a one-piece reflector.

[0015] The transparent lenses direct the light emitted from the light sources towards the display panel, ensuring homogeneous illumination. The reflector elements can, for example, form a rectangular grid. Arranging the lenses in a rectangular grid allows the reflector to be constructed from a continuous matrix of lenses.

[0016] The continuous axial recess of the lens according to the invention has the advantage of being particularly easy to manufacture, since it does not have a complex surface geometry. Furthermore, compared to a closed lens, it has a lower profile, making it particularly suitable for use in very flat designs.

[0017] The surface structure according to the invention on the upper surface of the lens allows it to be designed with an even lower profile compared to conventionally known lenses without such a surface structure. Light emitted from the light source is coupled into the lens and collimated. Individual collimated light rays then strike an inner surface of the lens almost perpendicularly. The surface of the lens with the surface structure is the lens's light-emitting surface. The light rays striking the lens's light-emitting surface are again coupled out of the lens almost perpendicularly. Depending on the characteristics of the individual components, this interaction leads to a non-uniform brightness distribution in the area of ​​the display panel. This is particularly the case when the lens is designed to be especially flat.The resulting extremely low profile often prevents completely uniform light distribution all the way to the light-emitting surface. The surface structure orients the light rays towards the display panel positioned above it. The lens's surface structure offers the advantage of efficiently regulating the brightness for illuminating the display panel, thus achieving uniformly homogeneous illumination across the entire surface.

[0018] Furthermore, it has been found that the flat lens with its surface structure makes it particularly easy to adapt the backlight to the design of the display device; that is, the height of the backlight can be varied. Thus, even with limited installation space, the distance between the circuit board and the display panel can be varied thanks to the lens's surface structure, without negatively impacting the uniform, homogeneous illumination.

[0019] Such a lens design, featuring a continuous axial recess and a surface texture on its upper surface, is advantageous when backlighting is required to illuminate a display panel in a very small space. The axial recess and the surface texture ensure the desired homogeneous illumination of the display panel. This allows for use in extremely confined spaces where the backlighting must be very flat. Compared to other solutions, the space requirements and installation effort of such a lens are significantly reduced.

[0020] According to one aspect of the invention, the surface structure in the edge region of the lens is very coarse and becomes progressively finer towards the axial recess of the lens. In the edge region of the lens, where the surface structure is very coarse, more light exits the top surface of the lens. Due to the coarse surface structure, more of this light is distributed to other areas. In the area of ​​the lens where the structure becomes increasingly finer, however, less and less light exits the top surface of the lens. Due to the fine surface structure, only a small amount of light is distributed to other areas. This change in the surface structure thus has the advantage of ensuring a uniform light distribution across the entire surface of the top surface of the lens, thereby achieving homogeneous illumination of the display panel and preventing overexposure in individual areas of the lens.

[0021] According to one aspect of the invention, the surface structure is a microstructure. Depending on the application and the size of the display panel to be illuminated, the lens's surface structure can be individually adapted and calculated to efficiently regulate brightness. The calculated microstructure can be applied to the lens surface particularly quickly, resulting in very low manufacturing costs and enabling the rapid production of large quantities. Furthermore, there is the advantage that no expensive tooling needs to be purchased or manufactured. The calculated surface structure can, for example, also be a nanostructure.

[0022] According to one aspect of the invention, an inner wall of the axial recess corresponds to the geometry of the light source. The inner wall of the axial recess can be radially symmetrical. The recess is, for example, round or polygonal. In the case of a polygonal design, the geometry of the recess is, for example, pentagonal or hexagonal. Furthermore, the recess can also be axially symmetrical, for example, rectangular.

[0023] One advantage is that the geometry of the axial recess can be easily adapted to the geometry of the light source, thus enabling the use of all conventional light sources, regardless of their size or geometry. This makes it particularly easy to ensure that the distances between the recess and the light source are uniform. Furthermore, the light-emitting surface of the light source is aligned approximately parallel to the respective inner wall of the recess. A light beam exiting the surface of the light source perpendicularly also strikes the surface of the inner wall perpendicularly.

[0024] According to one aspect of the invention, the geometry of the inner wall of the axial recess differs from the geometry of the light source. This results in the light emitted from different points of the light source being refracted differently upon striking the inner wall of the recess, leading to good light mixing and thus contributing to more homogeneous illumination.

[0025] According to one aspect of the invention, the lens has a stepped structure on its upper surface. This stepped structure is formed by at least one or more consecutive steps on the upper surface of the lens. The stepped structure on the upper surface corresponds, for example, to the structure of a Fresnel lens, also known as a Fresnel stepped lens. Additionally, the stepped structure, such as the Fresnel lens, is combined with a diffusing surface structure. Each of the steps has a surface structure, and the surface structure of the individual steps can be different.

[0026] A particular advantage of the stepped structure is that the light coupled into the lens from the light source is deflected to a defined degree, thus preventing unwanted, uncontrolled stray light and ensuring homogeneous illumination of the display panel. Furthermore, the stepped structure allows for a very low lens profile. For example, by using a calculated surface structure for the individual steps, a uniform and homogeneous light distribution across the lens surface can be achieved instead of uncontrolled stray light.

[0027] According to one aspect of the invention, surfaces of the stepped structure running essentially perpendicular to the axis of the lens have a surface structure. This has the advantage that such a surface structure is easy to produce. Furthermore, it is advantageous that such a lens can be easily demolded during manufacturing, for example, after an injection molding process. In addition, such a surface structure can be easily applied from above during subsequent processing.

[0028] According to one aspect of the invention, surfaces of the stepped structure running essentially parallel to the axis of the lens have a surface structure. This has the advantage that such a surface structure further increases the uniformity of the light distribution.

[0029] According to one aspect of the invention, the lens has a concave inward curve on its upper surface. It has been found that a lens with a concave inward curve on its upper surface is particularly easy to manufacture, as it can be easily demolded. A further advantage is that a concave upper surface with a surface texture enables particularly efficient illumination of display panels. A concave inward curve requires less material and is lighter.

[0030] In an alternative embodiment, the top surface of the lens can be flat and polished smooth. The lens surface is polished before any surface structure is applied. This results in a particularly fine and flat surface and removes manufacturing impurities.

[0031] In another alternative embodiment, the top surface of the lens can be flat and have a slope of the surface from the edge area of ​​the lens towards the axial recess of the lens.

[0032] When manufacturing the lens using injection molding, the surface structure is preferably molded directly into the mold. The injection mold has a polished surface onto which a negative mold of the surface structure is applied. This eliminates the need for post-processing.

[0033] According to one aspect of the invention, the lens has a chamfer on its underside. In the preferred case, the basic shape of the lens is a quadrilateral, with the underside of the lens having four chamfers. Each of the four chamfers extends from the underside of the lens to the edge region of the lens. In an alternative embodiment, the basic shape of the lens is round, with the chamfer extending radially along the underside.

[0034] A particular advantage of the bevel is that the light coupled into the lens from the light source is deflected in a defined amount towards the top of the lens and thus towards the stepped structure with the surface structure, thereby preventing unwanted, uncontrolled scattered light and achieving homogeneous illumination of the display panel.

[0035] According to one aspect of the invention, the lens has a stepped structure on its underside. This stepped structure is formed by at least one or more consecutive steps on the underside of the lens. The stepped structure on the underside corresponds to the structure of a Fresnel lens, also known as a Fresnel stepped lens. Additionally, the stepped structure, for example the Fresnel lens, can also be combined with a surface-scattering structure. This allows for targeted extraction of the light.

[0036] It has been found that a stepped structure on the underside of the lens allows for an even flatter lens height, which has the advantage that the light coupled into the lens from the light source is deflected in a defined amount, thus preventing unwanted, uncontrolled stray light and ensuring homogeneous illumination of the display panel.

[0037] The stepped structure is designed to achieve total internal reflection (TIR). This stepped structure allows for the simple realization of the desired homogeneous illumination of the display panel. A further advantage is that light loss is significantly reduced, enabling compact and efficient light redirection in a small space. The stepped structure can also be faceted, consisting of many small, smooth surfaces.

[0038] According to one aspect of the invention, the lens has a curved surface on its underside. A curved surface can be a freeform surface, for example a paraboloid, or a non-rotationally symmetric curved surface. It has been found that a lens with a curved surface on its underside is particularly easy to manufacture, as it can be easily demolded. One advantage is that a curved surface on the underside of the lens enables particularly efficient illumination of display panels, whereby the light from the light source coupled into the lens is fully utilized.

[0039] According to one aspect of the invention, the lens has a reflective surface on its underside. This reflective surface can be, for example, a static cling or self-adhesive film on the underside of the lens. The reflective surface can also be achieved by vapor deposition, sputtering, mirror coating, or high-gloss polishing. The reflective surface is applied to the underside of the lens, for example, on the bevel, the stepped structure, or the curved surface. An advantage is that the reflective surface is very easy and inexpensive to produce. Another advantage is that the reflective surface prevents stray light from being produced. The light coupled into the lens is thus used entirely for illumination, thereby avoiding areas of varying brightness.

[0040] According to one aspect of the invention, a reflector is arranged between the circuit board and the underside of the lens. The reflector is positioned between the lens's contact surface and the circuit board. The reflector can be limited to the lens's contact surface, or it can extend over a larger area of ​​the circuit board, for example, over the entire surface of the lens (projection of the lens onto the circuit board), a slightly larger area than the total surface of the lens, or even over the entire surface of the circuit board. The reflector may have recesses that are necessary for contacting and mounting individual components, particularly the light source, on the circuit board.

[0041] One advantage is that the light emitted by the light source is completely controlled and precisely directed. The reflector serves to create fill light or reduce shadows, ensuring even light distribution. Mounting such a reflector on the circuit board is generally more cost-effective than mirroring the underside of the lens.

[0042] Advantageously, the surface structure features indentations whose size decreases from the outer edge of the lens towards its center. This means that the size decreases from the edge of the lens towards the axial recess.

[0043] Advantageously, the surface structure features depressions, the number of which decreases per unit area from the outer edge of the lens towards its center.

[0044] Advantageously, the surface structure features depressions whose depth decreases from the outer edge of the lens towards its center.

[0045] According to one aspect of the invention, several lenses are arranged in a matrix and form an element. The element is, for example, a reflector of the display device, a reflector element, or part of a reflector element.

[0046] The matrix-like arrangement of lenses directs the light emitted from the light sources towards the display panel, ensuring homogeneous illumination. The lenses can form, for example, a rectangular or hexagonal grid. Both rectangular and hexagonal arrangements allow the reflector element, and thus the reflector itself, to be constructed from a continuous or nearly continuous matrix of lenses. The matrix-like arrangement of lenses can be regular, irregular, or staggered.

[0047] A matrix-like arrangement of lenses offers the advantage that the reflector elements are easy to manufacture and require no special tools. Furthermore, depending on the size of the display device, the reflector can be easily expanded with additional reflector elements, allowing it to be individually adapted to the size of the display. Unlike individual lenses, which must be aligned separately during assembly, a prefabricated matrix-like arrangement requires no such alignment.

[0048] According to one aspect of the invention, the light source has a rectangular geometry. An advantage is that rectangular light sources are commercially available at affordable prices. Due to its geometry, the rectangular light source emits light laterally in every direction (360 degrees).

[0049] According to one aspect of the invention, the light source is a side-emitting light source. The use of side-emitting light sources, also known as light-emitting diodes (LEDs), has the advantage of preventing the formation of light spots in the backlight. This ensures a particularly homogeneous illumination of the display panel in conjunction with the surface structure formed on the lens.

[0050] Preferably, a display device according to the invention is used in a means of transport in the automotive sector. The means of transport can be, for example, a motor vehicle, but alternatively also an aircraft, a rail vehicle or a watercraft.

[0051] Further features of the present invention will become apparent from the following description and the attached claims in conjunction with the figures. Advantageous embodiments of the invention will also become apparent from the features of the following description and the figures.

[0052] To better understand the principles of the present invention, embodiments of the invention are explained in more detail below with reference to the figures. The same reference numerals are used in the figures for identical or equivalently acting elements and are not necessarily described again for each figure. It is understood that the invention is not limited to the embodiments shown and that the described features can also be combined or modified without departing from the scope of protection of the invention as defined in the appended claims. Figure overview

[0053] They show, in a schematic, sketch-like representation: Fig. 1 a first embodiment of a display device according to the invention; Fig. 2 a second embodiment of a display device according to the invention; Fig. 3 a cutaway side view through a lighting module of the display device according to the invention; Fig. 4 in an oblique view from above a first embodiment of a lens of the illumination module of the display device according to the invention; Fig. 5 in an oblique view from above a second embodiment of a lens of the illumination module of the display device according to the invention; Fig. 6 in an oblique view from above a third embodiment of a lens of the illumination module of the display device according to the invention; Fig. 7 in an oblique view from above a fourth embodiment of a lens of the illumination module of the display device according to the invention; Fig. 8 in an oblique view from above a fifth embodiment of a lens of the illumination module of the display device according to the invention; Fig. 9 in an oblique view from above a sixth embodiment of a lens of the illumination module of the display device according to the invention; Fig. 10 in an oblique view from above a seventh embodiment of a lens of the illumination module of the display device according to the invention; Fig. 11 in an oblique view from above an eighth embodiment of a lens of the illumination module of the display device according to the invention; Fig. 12 in an oblique view from above a ninth embodiment of a lens of the illumination module of the display device according to the invention; Fig. 13 a cutaway side view through a lighting module with a reflector layer of the display device according to the invention; Fig. 14 in an oblique view from above an embodiment of a lens arrangement of a reflector element of the display device according to the invention; and Fig. 15 a means of transport which uses a display device according to the invention. Character description

[0054] Fig. Figure 1 schematically shows a first embodiment of a display device 10 according to the invention. Fig. 1a) the construction of the display device 10 and Fig. 1b) a detailed view of a reflector element 241 of the reflector 240 of the lighting module 200 of the display device 10 with lenses 250.

[0055] The display device 10 comprises a frame 400, a display panel 100, a film stack 500, a lighting module 200, and a housing 700, which are stacked on top of each other in the assembled state. The film stack 500 is arranged between the lighting module 200 and the display panel 100. The films of the optical film stack 500 are responsible for diffusing, focusing, or directing the light from the lighting module 200 to ensure homogeneous illumination of the display panel 100. Typical films used for light direction are brightness enhancement films (BEF) and light control films (LCF).

[0056] The lighting module 200 consists of a heat-conducting plate 600 and a backlight 210. The backlight 210 comprises a circuit board 220 arranged above the heat-conducting plate 600, with light sources 230 mounted on it, and a reflector 240 arranged above the circuit board 220 and the light sources 230. To ensure the longevity of the light sources 230 and the display device 10, the heat generated by the light sources 230 is dissipated from each individual light source 230 by means of the heat-conducting plate 600.

[0057] The heat-conducting plate 600 can also be a thermally conductive film or a material that is very thin and therefore has low thermal resistance. The heat-conducting plate 600 or the thermally conductive film is preferably designed to electrically insulate the circuit board 220 from the housing 700, for example to prevent short circuits. The reflector 240 consists of several modularly assembled reflector elements 241. Each of the reflector elements 241 consists of several lenses 250 arranged in a matrix, each lens 250 having a round geometry.

[0058] The lenses 250 each have an axially extending recess 253 with inner walls 254. In the embodiment shown here, the inner walls 254 of the recess 253 are rectangular. When a backlight 210, the reflector 240 with the circuit board 220 and the light sources 230 arranged thereon are mounted, each recess 254 of the lenses 250 is assigned a light source 230, wherein the light source 230 is typically a light-emitting diode, and the recess 254 completely surrounds the lens 250 laterally.

[0059] The lens 250 has a stepped structure 260 on its upper surface 251, a side facing the display panel 100. In the embodiment shown here, the stepped structure 260 corresponds to the structure of a Fresnel lens. The surface of the stepped structure 260 has a surface structure S, wherein the surface structure S changes in its spatial orientation.

[0060] For the sake of simplicity, in Fig. 1. The surface structure S is not shown in detail, but as in Fig. 12 shown are available.

[0061] The housing 700 of the display device 10 serves as a carrier plate for the lighting module 200, the film stack 500 arranged above it, and the display panel 100. The frame 400 encloses the housing 700 in its assembled state, sealing it off from the surrounding environment. The frame and the housing are connected to each other by suitable fasteners (not shown here), such as adhesive bonding.

[0062] Fig. Figure 2 schematically shows a second embodiment of a display device 10 according to the invention. Fig. 2a) the construction of the display device 10 and Fig. 2b) a detailed view of a reflector element 241' of the display device 10 with lenses 250'.

[0063] The second embodiment of the display device 10 largely corresponds to the embodiment from Fig. 1. However, the reflector 240' of the backlight 210 is formed in one piece. In an alternative embodiment not shown here, the reflector 240' can be, as in Fig. As described in Figure 1, the reflector 240' can also consist of several modularly assembled reflector elements. The reflector 240', or the individual reflector elements 241' (not shown), consists of several lenses 250' arranged in a matrix, each lens 250' having a rectangular geometry. Each lens 250' has an axially extending recess 253 with inner walls 254. In the illustrated embodiment, the inner walls 254 of the recess 253 are square. It can be seen that, due to the rectangular geometry of the lenses 250', no gap is formed between the individual lenses 250', and thus a gapless reflector 240' can be produced.In the assembled state of the reflector 240' with the circuit board 220 and the light sources 230 arranged on it, each recess 254 of the lenses 250' is assigned a light source 230, the light source 230 typically being a light-emitting diode, and is completely enclosed laterally. The lens 250' also has a stepped structure 260 on a top surface 251, a side facing the display panel 100. Each of the steps formed on the top surface 251', which constitute the stepped structure 260', extends over the entire width of the rectangular geometry of the top surface 251' of an edge of a lens 250'.

[0064] As in Fig. As described in Figure 1, the surface of the step structure 260' has a surface structure S, whereby the surface structure S changes in its spatial orientation. For the sake of simplicity, in Fig. 2. The surface structure S is not shown in detail, but as in Fig. 4 shown are available.

[0065] Fig. Figure 3 shows a sectional side view through a lighting module 200 of the display device 10 according to the invention. The circuit board 220 with the light source 230 arranged on the circuit board and the lens 250' are visible. The lens 250' is rectangular and has a continuous axial recess 253, with the light source 230 sitting in the recess 253 of the lens 250' when mounted. The axial recess 253 is rectangular and has walls 254. The lens 250' encloses the light source 230 together with the circuit board 220 when mounted. The light source 230 is a side-emitting LED, which preferably emits light L from all sides. In a preferred embodiment, the light source 230 has a rectangular geometry, like the recess 253 of the lens 250'. The lens 250' has a chamfer 270 on its underside 252', in the direction of the circuit board 220.The walls 254 of the recess 253 reflect part of the light L towards the top of the lens 251', above the light source 230. Another part of the light L is directed into the lens 251' towards the edge 270, where the light L is again directed towards the top of the lens 251'. There, the light L strikes the stepped structure 260' formed on the top of the lens 251'. The stepped structure 260' has, as shown above in . Fig. As described in section 2, a surface structure S is present on the upper surface. The surface structure S is visible in the sectioned side view through the lens at 250°. Fig. 3 not visible, but present. The light L, after striking the stepped structure 260' with the surface structure S formed on it, is coupled back out of the lens 250'. The stepped structure 260' and the surface structure S diffuse the light L uniformly in the direction of the Fig. The light is distributed across the two display panels shown to ensure uniform illumination across the entire surface. The transparent lens 250' allows the light L emitted by the light source 230 to pass through largely unimpeded, except for a small portion, until the light L strikes the bevel 270 and is deflected. The design of the lens 250' according to the invention allows its height to be almost perfectly matched to the height of the light source 230, thus enabling a very flat design of the lighting module.

[0066] Fig. Figure 4 shows schematically in an oblique view from above the in Fig. Figure 3 shows the first embodiment of the lens 250' of the lighting module 200. The lens 250' is shown with a light source 230 arranged in the lens 250'. This embodiment of the lens 250' corresponds to the embodiment described in Figure 3. Fig. 3. In Fig. Figure 4 illustrates once again that the walls 254 of the continuous axial recess 253 of the lens 250' are arranged parallel to the side edges of the light source 230. Furthermore, an oblique view from above shows the stepped structure 260' with surface structure S formed on the upper surface 251' of the lens 250', as well as the chamfer 270 formed on the lower surface 252' of the lens 250'. The surface structure S is shown to be greatly enlarged for illustrative purposes. The surface structure S changes in its spatial profile. In the edge region of the lens 250', the surface structure S is very coarse and becomes increasingly finer towards the axial recess 253 of the lens 250'. The light source 230 is a rectangular, laterally emitting light source. Each of the individual steps of the lens 250' thus has a different surface structure S.Here, the surface structure S is shown as an example consisting of circular depressions, the number of which decreases from the outside to the inside per unit area. The surface structure S formed on the surface of the lens 250' orients light L from a light source 230 towards the display panel 100 arranged above it. It can also be seen that, in the embodiment shown here, the flanks of the stepped structure 260' running parallel to the axis of the lens 250' do not have a surface structure S, while the steps connecting them, which run essentially perpendicular to the axis of the lens 250', are provided with a surface structure S. The geometry of the light source 230 corresponds to the geometry of the recess 253 of the lens 250'.

[0067] Fig. Figure 5 schematically shows, in an oblique top view, a second embodiment of a lens 250' of the illumination module of the display device according to the invention. This embodiment largely corresponds to the embodiment shown in Figure 5. Fig. 4. However, the top surface 251' of the lens 250' is flat. The top surface 251' of the lens 250' is polished smooth before a surface structure S is applied. The surface structure S changes in its spatial orientation. In the edge region of the lens 250', the surface structure S is very coarse and becomes increasingly finer towards the axial recess 253 of the lens 250'.

[0068] Fig. Figure 6 schematically shows, in an oblique top view, a third embodiment of a lens 250' of the illumination module of the display device according to the invention. This embodiment largely corresponds to the embodiment shown in Figure 6. Fig. 5. However, the upper surface 251' of the lens 250' is not flat, but rather has a slope from the edge of the lens 250' towards the axial recess 253 of the lens 250'. The surface structure S formed on the upper surface 251' of the lens 250' changes in its spatial orientation. In the edge region of the lens 250', the surface structure S is very coarse and becomes increasingly finer towards the axial recess 253 of the lens 250'.

[0069] Fig. Figure 7 schematically shows, in an oblique top view, a fourth embodiment of a lens 250' of the illumination module 200 of the display device according to the invention. The lens 250' is shown with a light source 230 arranged within it. In the assembled state, the lens 250' surrounds the light source 230. This embodiment of the lens 250' largely corresponds to the embodiment shown in Figure 7. Fig. 4. However, the wall 254 of the continuous axial recess 253 of the lens 250' is hexagonal, thus forming six walls 254 that enclose the light source 230. The light source 230 is a rectangular, laterally emitting light source 230, as already described in Fig. 3 described. The upper surface 251' of the lens 250' has a surface structure S. The surface structure S is formed both on the surface of the steps of the upper surface 251' of the lens 250' and on the surface of the flanks, the transition area, between the individual steps of the stepped structure 260'. In addition, in the embodiment shown here, the innermost step in the innermost region is formed entirely without surface structure S.

[0070] Fig. Figure 8 schematically shows, in an oblique top view, a fifth embodiment of a lens 250' of the illumination module 200 of the display device according to the invention. In the assembled state, the lens 250' surrounds the light source 230. The illustration shows a lens 250' with a light source 230 arranged within the lens 250'. This embodiment of the lens 250' largely corresponds to the embodiment shown in Figure 8. Fig. 4. However, the wall 254 of the continuous axial recess 253 of the lens 250' is round. The light source 230 is a rectangular, laterally emitting light source 230, as already described in Fig. 3 described. As previously described, the top surface 251' of the lens 250' has a surface structure S.

[0071] Fig. Figure 9 schematically shows, in an oblique top view, a sixth embodiment of a lens 250' of the illumination module 200 of the display device according to the invention. A lens 250' with a light source 230 arranged in the lens 250' is shown. This embodiment of the lens 250' largely corresponds to the embodiment shown in Figure 9. Fig. 4. In its assembled state, the lens 250' encloses the light source 230. However, the lens 250' has a reflective surface 272 on its underside 252'. The reflective surface 272 is applied to the chamfer 270 of the lens 250'. This reflective surface 272 on the chamfer 270 of the lens 250' ensures that the light L (not shown) emitted by the light source 230, after being coupled into the lens 250', is directed completely towards the top 251', resulting in complete reflection. This prevents stray light in the edge region of the lens 250'. The light source 230 is a rectangular, laterally emitting light source, as already described in Fig. 3 described. As previously described, the top surface 251' of the lens 250' has a surface structure S.

[0072] Fig. Figure 10 shows, in an oblique top view, a seventh embodiment of a lens 250' of the illumination module 200 of the display device according to the invention. In the assembled state, the lens 250' surrounds the light source 230. A lens 250' with a light source 230 arranged in the lens 250' is shown. This embodiment of the lens 250' largely corresponds to the embodiment shown in Figure 10. Fig. 4. However, the lens 250' has a step structure 271 on its underside 252', the step structure 271 being in the Fig. The chamfer 270 described in section 3 is formed. The stepped structure 271 extends over the entire underside 252' of the lens from the wall 254 of the recess 253 of the lens 250' to the edge region of the lens 250'. This is an alternative embodiment to the one described in Fig. The reflective surface 272 described in section 7 is located on the underside 252' of the lens 250'. Total internal reflection of the coupled light L (not shown here) prevents stray light in the edge region of the lens. The light source 230 is a rectangular, laterally emitting light source 230, as already described in Fig. 3 described. As previously described, the top surface 251' of the lens 250' has a surface structure S.

[0073] Fig. Figure 11 schematically shows, in an oblique top view, an eighth embodiment of a lens 250' of the illumination module 200 of the display device according to the invention. This embodiment of the lens 250' largely corresponds to the embodiment shown in Figure 11. Fig. 4. In its assembled state, the lens 250' encloses the light source 230. However, the underside 252' of the lens 250' is designed as a curved surface 273. The curved surface 272 extends over the entire underside 252' of the lens from the wall 254 of the recess 253 of the lens 250' to the edge region of the lens 250'. This is essentially an alternative embodiment to the embodiments described previously. It can also be provided with a reflective surface 272 and / or have a stepped structure with finely resolved steps on the underside 252' of the lens 250'. Here, too, almost all of the coupled light L (not shown here) is reflected, and stray light in the edge region of the lens is avoided. The light source 230 is a rectangular, laterally emitting light source 230, as already described in Fig. 3 described.

[0074] Fig. Figure 12 schematically shows, in an oblique top view, a ninth embodiment of a lens 250 of the lighting module. This embodiment of the lens 250 corresponds to the embodiment shown in Figure 12. Fig. 1b) The lens has a continuous axial recess 253 with walls 254 and a stepped structure 260 formed on its upper surface 251. The stepped structure 260 has a surface structure S. The surface structure S formed on the upper surface 251 of the lens 250 changes in its spatial orientation. In the edge region of the lens 250, the surface structure S is very coarse and becomes increasingly finer towards the axial recess 253 of the lens 250. The surface structure S is formed on the surface of the upper surface 251 of the lens 250 and on the surface of the flanks, a transition region between the individual steps of the stepped structure 260. An axially extending chamfer 270 is formed on the lower surface 252 of the lens 250. The chamfer 270 extends over the entire underside 252 of the lens from the wall 254 of the recess 253 to the edge area of ​​the lens 250.In the recess 253 with the four walls 254 a light source 230 is arranged, wherein the light source is a square, laterally emitting light source 230, as already in . Fig. 3 described.

[0075] Fig. Figure 13 shows a cutaway side view through a lighting module 200 of the display device 10 according to the invention. The circuit board 220 with the light source 230 arranged on the circuit board and the lens 250' are visible. This embodiment largely corresponds to the embodiment shown in [reference missing]. Fig. 3. However, a reflector 300 is arranged between the contact surface of the lens 250' and the circuit board 220. The reflector extends over the entire surface of the circuit board 220. The reflector 300 has recesses (not shown here) that serve for contacting and securing the light source 230 to the circuit board.

[0076] Fig. Figure 14 schematically shows an embodiment of a reflector element 241 in an oblique top view. The in Fig. 14a) The reflector element 241 shown consists of several lenses 250 arranged in a matrix, each of the lenses 250 being arranged regularly next to or below one another, thus forming a matrix. Each of the lenses 250 has a round geometry, with voids between the transitions from one lens 250 to the adjacent next lens 250. This embodiment of the reflector element 241 corresponds to the embodiment shown in Fig. 1. The one in the Fig. Figure 14b) shows a reflector element 241 representing an alternative embodiment for the arrangement of the lenses 250. The reflector element 241 consists of several lenses 250 arranged in a matrix, the lenses 250 being arranged in rows offset from one another. The reflector element comprises several rows of lenses 250, each row of lenses 250 being offset by half the diameter of a lens 250 in the preceding row. Each of the lenses 250 has a round geometry. Thus, a row of lenses 250 following a preceding row completes the arrangement as shown in Figure 14b). Fig. 14a) shown empty spaces between the lenses 250.

[0077] Fig.Figure 15 schematically shows a means of transport 800 that uses a display device 10 according to the invention. In this example, the means of transport 800 is a motor vehicle. The motor vehicle has a display device 10 according to the invention, which is arranged in an instrument panel. Data about the vehicle's environment can be acquired by means of sensors 810. The sensors 810 can, in particular, include sensors for environmental detection, e.g., ultrasonic sensors, laser scanners, radar sensors, lidar sensors, or cameras. The information acquired by the sensors 810 can be used to generate content to be displayed on the display device 10. Further components of the motor vehicle in this example are a navigation system 820, which can provide position information, and a data transmission unit 830. The data transmission unit 830 can, for example, be used to transmit the vehicle's location.A connection to a backend is established, for example, to obtain updated software for vehicle components. A memory module (840) is available for data storage. Data exchange between the various vehicle components takes place via a network module (850).

[0078] Overall, the exemplary embodiment shows how the invention can be used to design an improved display device with a backlight and a means of transport with such a display device in a simple manner, so that a particularly flat installation height of the backlight, in particular of the lens, is achieved for a uniformly homogeneous backlighting of the display panel of the display device. Reference symbol list 10 Display device 100 display panels 200 lighting modules 210 Backlight 220 circuit board 230 light source 240, 240' Reflector 241, 241' Reflector element 250, 250' lens 251, 251' Top of lens 252, 252' Underside of lens 253 Exclusion 254 Interior wall 260, 260' step structure 261 microlenses 270 Bevel 271-level structure 272 Reflective surface 273 curved surface 300 reflector layer 400 frames 500 foil 600 heat-conducting plate 700 cases 800 means of transport 810 Sensors 820 Navigation system 830 Data transmission unit 840 memory 850 network L light S surface structure QUOTES INCLUDED IN THE DESCRIPTION

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

[0000] DE 10 2022 205 566 A1

[0004] US 2005 / 0276069 A1

[0005] DE 10 2007 007 353 A1

[0006] EP 4 099 050 A1

[0007] DE 102 26 471 A1

[0008]

Claims

Display device (10) with a display panel (100) and a backlight (210) for the display panel (100), wherein the backlight (210) comprises a circuit board with a plurality of light sources (230) arranged on the circuit board (220), wherein each of the light sources (230) is associated with a lens, wherein the lens (250, 250') surrounds the light source (230), characterized in that the lens (250, 250') has a continuous axial recess (253) in which the light source (230) is arranged, and a surface of a top (251, 251') of the lens (250, 250') has a surface structure (S), wherein the surface structure (S) changes in its spatial direction. Display device (10) according to claim 1, characterized in that the surface structure (S) in the edge region of the lens is very coarse and becomes increasingly finer in its course towards the axial recess (253) of the lens (250, 250'). Display device (10) according to one of the preceding claims 1 to 2, characterized in that the surface structure (S) is a microstructure. Display device (10) according to one of the preceding claims 1 to 3, characterized in that the lens (250, 250') has a stepped structure (260, 260') on the upper surface (251, 251'). Display device (10) according to claim 4, characterized in that surfaces of the step structure (260, 260') extending substantially perpendicular to the axis of the lens (250, 250') have a surface structure (S). Display device (10) according to one of the preceding claims 4 to 5, characterized in that surfaces of the step structure (260, 260') extending substantially parallel to the axis of the lens (250, 250') have a surface structure (S). Display device (10) according to one of the preceding claims 1 to 6, characterized in that the lens (250, 250') is concavely curved inwards on the upper side (251, 251'). Display device (10) according to one of the preceding claims 1 to 7, characterized in that the surface structure (S) has recesses whose size decreases from the outer edge of the lens (250, 250') towards its center. Display device (10) according to one of the preceding claims 1 to 8, characterized in that the surface structure (S) has recesses, the number of which per unit area decreases from the outer edge of the lens (250, 250') towards its center. Display device (10) according to one of the preceding claims 1 to 9, characterized in that the surface structure (S) has depressions whose depth decreases from the outer edge of the lens (250, 250') towards its center. Display device (10) according to one of the preceding claims 1 to 10, characterized in that several lenses (250, 250') are arranged in a matrix and form a reflector element (241). Means of transport (800) with a display device (10) according to one of the preceding claims 1 to 11 .

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