Backlight module for display panel, display equipment and transportation tool

Abstract

The invention relates to a backlight module (3) for a display panel (2). The invention further relates to a display device having such a backlight module (3) and to a vehicle having such a display device. A backlight module (3) for a display panel (2) according to the invention comprises a circuit board (33) having a plurality of light sources (32) arranged thereon, a film reflector (30) having a plurality of reflective cavities (31), and a support element (34) for the film reflector (30). At least one light source (32) is arranged in each of the cavities (31). The support element (34) is adapted to the shape of the film reflector (30) such that the film reflector (30) rests against the circuit board (33).

Description

Technical Field

[0001] This invention relates to a backlight module for a display panel. Furthermore, the invention also relates to a display device having such a backlight module and a transport vehicle having such a display device. Background Technology

[0002] The number and area of ​​display devices in transportation vehicles are constantly increasing. Display devices such as driver's instrument clusters, central displays, and passenger displays are available on the market. Non-self-emissive transmissive display devices require backlight modules for image display. Here, the task of the backlight module is to illuminate the display panel as uniformly as possible over the entire effective area to produce a display that is as uniform as possible evenly as possible, even to the edge areas.

[0003] Matrix backlight modules use multiple light sources arranged in a matrix to generate light. Here, reflectors are used to direct the light from the light sources toward the display panel.

[0004] For example, DE 10 2007 007 353 A1 describes a lighting device with a luminous surface, which can be composed of multiple radiating reflectors in a modular manner. Honeycomb, scale-like, triangular, or rectangular radiating reflectors are preferred. Each of these radiating reflectors has multiple radiating reflective surfaces that arch outward from the center where the light source is arranged.

[0005] In particular, thin-film reflectors can also be used as reflectors. For example, US 10,613,386 B2 describes a backlight module device having multiple light sources arranged in a matrix and a reflective film with partitions. These partitions are arranged such that they surround the light sources in four directions.

[0006] To ensure a defined position for the thin-film reflector, it can be adhered to the lighting circuit board using an adhesive foil. Here, the use of the adhesive film affects the height structure. The reflector's height is increased by the thickness of the adhesive film. This negatively impacts light output, especially in the case of side-emitting light sources.

[0007] Against this backdrop, US 2023 / 0012552 A1 describes a light-emitting device having a substrate, a plurality of light sources arranged on the substrate, and a plurality of light-reflecting elements arranged on the substrate. The light-reflecting elements are back-molded through openings in the substrate using resin.

[0008] However, back-side injection molding using resin is quite time-consuming. Summary of the Invention

[0009] The purpose of this invention is to propose an improved solution for implementing a backlight module for a display panel.

[0010] This objective is achieved by a backlight module having the features of claim 1, by a display device according to claim 9, 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 one aspect of the present invention, a backlight module for a display panel includes:

[0012] - A circuit board on which multiple light sources are arranged;

[0013] - A thin-film reflector having multiple cavities designed for reflection, wherein at least one light source is arranged in each cavity; and

[0014] - A support element for the thin-film reflector, which matches the shape of the thin-film reflector so that the thin-film reflector is attached to the circuit board.

[0015] In the embodiment of the invention, the adhesive film can be omitted by using a support element for the thin-film reflector. Here, the thin-film reflector is positioned by the support element in such a way that it is directly attached to the circuit board. This support element enables simple mounting of the thin-film reflector. Furthermore, the efficiency of the thin-film reflector can be improved because the curvature of the reflective surface of the thin-film reflector can begin closer to the light source.

[0016] According to one aspect of the invention, during the manufacturing process of the backlight module, a support element is first installed, and then a thin-film reflector is mounted on the support element. Alternatively, the support element and the thin-film reflector can be pre-assembled. This has the advantage of reducing the number of assembly steps required to assemble the backlight module.

[0017] According to one aspect of the invention, the support element is made of plastic. For example, the support element can be manufactured by injection molding. By using plastic, a great deal of design freedom is provided while maintaining the light weight of the support element.

[0018] According to one aspect of the invention, the support element is implemented in white. This has the advantage that the reflection of the thin film of the thin film reflector is not affected.

[0019] According to one aspect of the invention, the support element has positioning elements. These positioning elements facilitate the alignment of the support element during the installation of the backlight module.

[0020] According to one aspect of the invention, the support element is fastened to the circuit board or housing of the backlight module. Here, the fastening can be done in a releasable manner, for example, by screwing or plugging. For this purpose, locking lugs may be optionally provided. The releasable connection has the advantage that, in the event of maintenance, the support element and the circuit board can be reused. Alternatively, the support element can be fastened non-releasably, for example, by means of liquid adhesive or tape. The fastening element can also be plastically deformed, optionally accompanied by temperature input. In particular, the fastening element can also be used simultaneously as a positioning element.

[0021] According to one aspect of the invention, the support element is fully or partially abutted against the circuit board. In this way, the position of the support element relative to the circuit board or relative to the light source is well defined.

[0022] According to one aspect of the invention, the thin-film reflector is bonded to the support element. Bonding can be performed, for example, by means of liquid adhesive or tape. Alternatively, the thin-film reflector can be detachably connected to the support element, for example, by a plug-in connection. For this purpose, locking lugs may be optionally provided. The detachable connection has the advantage that, in the event of maintenance, both the support element and the thin-film reflector can be reused.

[0023] According to one aspect of the invention, the support element is designed in a grid pattern. Since the light source and therefore the reflective cavity are typically arranged in a grid pattern, it is proposed that the support element also be designed in a grid pattern. In particular, it can be suggested that the number of ribs in the support element corresponds to the number of lines in the matrix of the thin-film reflector, i.e., all cavities of the thin-film reflector are supported by the support element. To save weight, the ribs in the support element can be designed to be partially interrupted or reduced.

[0024] According to one aspect of the invention, the mesh structure of the support element is coarser than that of the thin-film reflector. This enables savings in the weight and material of the support element. Here, those skilled in the art can determine for themselves the trade-off between material savings and the support effectiveness of the support element.

[0025] According to one aspect of the invention, the support element is designed as a single piece or in multiple pieces. The single-piece design simplifies the operation of the support element, while the multiple-piece design provides the possibility of assembling support elements of different sizes from basic components.

[0026] According to one aspect of the invention, the shape of the support element matches the internal contour of the thin-film reflector. The internal contour of the thin-film reflector can, in particular, be designed to be curved. Deformation is avoided by matching the shape of the support element to this internal contour.

[0027] Preferably, the backlight module source according to the invention is used in a display device having a display panel. This display device is characterized by more efficient illumination, which enables higher brightness or reduced power consumption. Preferably, the display device according to the invention is applied in a means of transportation. This means of transportation may be, for example, a motor vehicle, an aircraft, a rail vehicle, or a watercraft.

[0028] Other features of the invention will be shown in conjunction with the accompanying drawings from the following description and the appended claims. Attached Figure Description

[0029] Figure 1 A cross-section of a display device according to the prior art is schematically shown;

[0030] Figure 2 schematically shown Figure 1 A detailed view of the backlight module of the display device;

[0031] Figure 3 schematically showing through Figure 2 The optical orientation of the thin-film reflector in the backlight module;

[0032] Figure 4 A schematic view of a backlight module according to the present invention is shown in detail.

[0033] Figure 5 schematically showing through Figure 4 The optical orientation of the thin-film reflector in the backlight module;

[0034] Figure 6 A perspective view of a thin-film reflector pre-mounted on a support element according to a first embodiment is shown schematically.

[0035] Figure 7 A perspective view of a thin-film reflector pre-mounted on a support element according to the second embodiment is shown schematically.

[0036] Figure 8 A perspective view of a thin-film reflector pre-mounted on a support element according to a third embodiment is shown schematically; and

[0037] Figure 9 A vehicle using a display device according to the present invention is illustrated schematically. Detailed Implementation

[0038] To better understand the principles of this invention, embodiments will be explained in detail below with reference to the accompanying drawings. In the drawings, the same reference numerals are used for the same or functionally identical elements, and they are not necessarily described repeatedly in every drawing. It should be understood that this invention is not limited to the illustrated embodiments, and the described features can be combined or modified without departing from the scope of protection defined in the appended claims.

[0039] Figure 1 A cross-section of a display device 1 according to the prior art is schematically shown. The display device 1 has a display panel 2, which is bonded to a cover glass 4. The cover glass 4 encloses the housing 8 of the display device 1 relative to the surrounding environment. A backlight module 3 for the display panel 2 is arranged in another housing 7. The backlight module 3 has a thin-film reflector 30 with multiple cavities 31. A light source 32, typically a light-emitting diode, is arranged in each cavity 31. The light source 32 is arranged on a circuit board 33, which can be bonded to the housing 7 of the backlight module 3. The thin-film reflector 30 is fastened to the circuit board 33 by means of an adhesive film 35. In the example shown, an optical plate 5 is present between the backlight module 3 and the display panel 2, the optical plate having an optical thin-film stack 6 arranged on the optical plate. The task of the thin film of the optical thin-film stack 6 is to scatter, converge, or direct the light from the thin-film reflector 30, thereby meeting the spatial angle requirements of the backlight module 3. Typical thin films used for light alignment 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 thin film stack 6 and the light source 32. The cover glass 4, the optical plate 5, and the housing 7 of the backlight module 3 are interconnected by suitable connecting elements 9 (e.g., adhesive bonding).

[0040] Figure 2 schematically shown Figure 1 A detailed view of the backlight module 3 of the display device. The circuit board 33, the light source 32 arranged on it, and the thin-film reflector 30 fastened to the circuit board 33 by means of an adhesive film 35 can be seen. Figure 3 The optical orientation of the thin-film reflector 30 is schematically shown. In this example, the light source 32 is a side-emitting light-emitting diode that emits light L in various directions. As can be clearly seen, the lower light rays L emitted in the lower region... u It cannot be used because it does not reach the reflecting surface 300 of the thin-film reflector 30.

[0041] Figure 4A schematic detailed view of the backlight module 3 according to the invention is shown. Again, the circuit board 33 (on which the light source 32 is arranged) and the thin-film reflector 30 can be seen. In the solution according to the invention, the thin-film reflector 30 is not fastened to the circuit board 33 by means of an adhesive film. Instead, a support element 34 is used for the thin-film reflector 30. It is preferably made of plastic and conforms to the shape of the thin-film reflector 30, such that the thin-film reflector 30 rests against the circuit board 33. Here, the thin-film reflector 30 can be connected to the support element 34 in a releasable or non-releasable manner. In the illustrated embodiment, the support element 34 has a positioning element 340 that engages in an opening 330 of the circuit board. Preferably, the support element 34 is fastened to the circuit board. Here, the fastening can be releasable or non-releasable. The support element 34 is designed to completely or partially fill at least some of the cavities 301 of the thin-film reflector 30. Here, the shape of the support element 34 preferably conforms to the internal contour of the thin-film reflector 30.

[0042] exist Figure 5 The diagram schematically illustrates the optical orientation through the thin-film reflector 30. Here, the light source 32 is also a side-emitting light-emitting diode, emitting light L in all directions. (As shown in the diagram...) Figure 3 It can be clearly seen that the lower rays emitted in the lower region... Lu A significant proportion of the light is incident on the reflective surface 300 of the thin-film reflector 30, and therefore can be used as backlight for the display panel.

[0043] Figure 6 A perspective view schematically illustrating a thin-film reflector 30 pre-mounted on a support element 34 according to a first embodiment is shown. The mesh structure of the thin-film reflector 30 is clearly visible. Matching this mesh structure, the support element 34 also has a mesh structure. However, this mesh structure is formed more coarsely than that of the thin-film reflector 30; that is, in the illustrated example, each mesh unit 341 of the support element 34 comprises 4 × 5 cavities 31 of the thin-film reflector 30. The mesh unit 341 is surrounded by a surrounding frame 342 of the support element 34. In the illustrated example, the support element 34 is designed as a single piece; however, the support element could also be designed as a multi-piece structure. Furthermore, the various positioning elements 340 of the support element 34 are visible.

[0044] Figure 7 A perspective view of a thin-film reflector 30 pre-mounted on a support element 34 according to the second embodiment is shown schematically. Here, the support element 34 also has a coarser mesh structure than the mesh structure of the thin-film reflector 30. However, the size of the mesh cells 341 of the support element 34 varies.

[0045] Figure 8A perspective view schematically shown of a thin-film reflector 30 pre-mounted on a support element 34 according to a third embodiment. This embodiment is largely consistent with... Figure 6 Corresponding to the implementation described above, the grid cells 341 have uniform dimensions. However, the ribs 343 of the support element 34 have recesses 344. This allows for weight and material savings without unduly compromising the stability and support effect of the support element 34.

[0046] Figure 9 A vehicle 100 using a display device 1 according to the invention is schematically shown. In this example, the vehicle 100 is a motor vehicle. The motor vehicle has a display device 1 according to the invention, which is arranged in the dashboard. Data about the vehicle environment can be collected by means of a sensing device 101. The sensing device 101 may include, in particular, sensors for environmental identification, such as ultrasonic sensors, laser scanners, radar sensors, lidar sensors, or cameras. The information collected by the sensing device 101 can be used to generate content to be displayed on the display device 1. In this example, other components of the motor vehicle include a navigation system 102 and a data transmission unit 103, through which location information can be provided. A connection to a backend can be established via the data transmission unit 103, for example, for obtaining updated software for motor vehicle components. A memory 104 is provided for storing data. Data exchange between the various components of the motor vehicle is carried out via a network 105.

[0047] List of reference numerals in the attached diagram:

[0048] 1 Display device

[0049] 2 Display Panels

[0050] 3 backlight modules

[0051] 30 Thin-film reflectors

[0052] 300 reflective surface

[0053] 301 cavity

[0054] 31 cavities

[0055] 32 light sources

[0056] 33 circuit board

[0057] 330 opening

[0058] 34 support elements

[0059] 340 positioning element

[0060] 341 mesh cells

[0061] 342 frame

[0062] 343 ribs

[0063] 344 concavity

[0064] 4 cover glass

[0065] 5 optical plates

[0066] 6 thin film stacks

[0067] 7 Backlight Module Housing

[0068] 8. Display device housing

[0069] 9 connecting elements

[0070] 100 vehicles

[0071] 101 sensor device

[0072] 102 Navigation System

[0073] 103 Data Transmission Unit

[0074] 104 memory

[0075] 105 Network

[0076] L-light

[0077] Lu's lower ray.

Claims

1. A backlight module (3) for a display panel (2), the backlight module having: - Circuit board (33), the circuit board having a plurality of light sources (32) arranged on the circuit board; - Thin-film reflector (30), the thin-film reflector having multiple reflectively designed cavities (31), wherein, At least one light source (32) is arranged in each of the cavities; and - A support element (34) for the thin film reflector (30), the support element being matched to the shape of the thin film reflector (30) so that the thin film reflector (30) is attached to the circuit board (33).

2. The backlight module (3) according to claim 1, characterized in that, The support element (34) is fastened to the circuit board (33) or the housing (7) of the backlight module (3).

3. The backlight module (3) according to claim 2, characterized in that, The support element (34) is fully or partially attached to the circuit board (33).

4. The backlight module (3) according to any one of the preceding claims, characterized in that, The thin-film reflector (30) is bonded to or detachably connected to the support element (34).

5. The backlight module (3) according to any one of the preceding claims, characterized in that, The support element (34) is designed as a grid.

6. The backlight module (3) according to claim 5, characterized in that, The grid structure of the support element (34) is coarser than that of the thin film reflector (30).

7. The backlight module (3) according to any one of the preceding claims, characterized in that, The support element (34) is constructed as a single unit or multiple units.

8. The backlight module (3) according to any one of the preceding claims, characterized in that, The shape of the support element (34) matches the internal contour of the thin film reflector (30).

9. A display device (1) having a display panel (2), characterized in that, The display device (1) has a backlight module (3) according to any one of the preceding claims.

10. A means of transport (100) having a display device (1) according to claim 9.

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