Backlight module, display screen, and vehicle

Abstract

A backlight module (20), a display screen (103), and a vehicle (100). The backlight module (20) comprises a housing (21), a light guide plate (23) and an LED light source (22). The light guide plate (23) comprises a first surface (231) and a second surface (232), disposed opposite each other along a first direction (Z). The LED light source (22) and the light guide plate (23) are arranged along a second direction (X). According to the arrangement position of the LED light source (22), the backlight module (20) is a side-edge backlight module. The first direction (Z) is perpendicular to the second direction (X). The LED light source (22) comprises a substrate (221) and a light-emitting unit (222) disposed on the substrate (221). The substrate (221) is mounted in the housing (21), and a normal line of the substrate (221) is oriented toward the first surface (231). An included angle between a plane in which the surface of the substrate (221) facing away from the light-emitting unit (222) is located and the first direction (Z) is greater than 0° and less than 90°, such that the size of the LED light source (22) is reduced in the first direction (Z), thereby facilitating reducing the thicknesses in the first direction (Z) of the light guide plate (23) and the backlight module (20), and accordingly facilitating compactness of the backlight module (20).

Description

Backlight modules, displays and vehicles

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office of China on February 29, 2024, with application number 202410236033.X and application name “Backlight module, display screen and vehicle”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of display technology, and in particular to a backlight module, a display screen and a vehicle. Background Art

[0003] Due to the backlight module and other components of liquid crystal displays (LCDs), LCDs are significantly thicker than organic light-emitting diode (OLED) displays. This hinders their application in applications such as vehicle installation. Reducing the thickness of LCDs is a future development challenge. Summary of the Invention

[0004] The embodiments of the present application provide a backlight module, a display screen, and a vehicle that are advantageous in reducing thickness.

[0005] In a first aspect, an embodiment of the present application provides a backlight module comprising a housing, a light guide plate and an LED light source, wherein the light guide plate comprises a first surface and a second surface arranged opposite to each other along a first direction. The LED light source and the light guide plate are arranged along a second direction. According to the setting position of the LED light source, the backlight module is side-lit. The first direction is perpendicular to the second direction. The LED light source comprises a substrate and a light-emitting unit arranged on the substrate. The substrate is mounted on the housing, and the normal of the substrate is arranged toward the first surface. The angle between the plane of the substrate facing away from the light-emitting unit and the first direction is greater than 0° and less than 90°.

[0006] In the backlight module provided by the present application, the angle between the plane of the substrate and the first direction is greater than 0° and less than 90°, that is, the substrate is tilted relative to the first direction, so that the entire LED light source is tilted relative to the first direction, reducing the size of the LED light source in the first direction. Since the size of the LED light source in the first direction is reduced, the thickness of the light guide plate and the backlight module in the first direction is reduced, thereby promoting the development of a lighter and thinner backlight module and facilitating the installation of a display screen having the backlight module.

[0007] Since the LED light source is only tilted relative to the first direction, the size, specification and structure of the LED light source remain unchanged. While reducing the thickness of the light guide plate, the light output of the LED light source can be guaranteed to remain unchanged, which is beneficial to improving the utilization rate of light energy.

[0008] In addition, since the substrate is mounted on the housing rather than on the light guide plate, there is no need to provide a structure for mounting the LED light source on the light guide plate, such as a mounting groove. This simplifies the structure of the light guide plate and facilitates the manufacture of the light guide plate.

[0009] According to the first aspect, in a possible implementation, the backlight module further includes a reflective film, and the reflective film is configured to reflect light incident on the reflective film toward the light guide plate.

[0010] In this possible implementation, part of the light emitted by the LED light source is directly coupled into the light guide plate, and the other part enters the light guide plate after being reflected by the reflective film, thereby reducing light loss and improving the utilization rate of light energy.

[0011] According to the first aspect, in a possible implementation manner, the reflective film and the LED light source are arranged along a first direction, the reflective film is a plane, and the reflective film is perpendicular to the first direction.

[0012] In this possible implementation, since the reflective film and the LED light source are arranged along the first direction and the reflective film is set to be flat, the reflective film does not occupy or reduces the space occupied by the backlight module, which is conducive to making the backlight module lighter and thinner.

[0013] According to the first aspect, in a possible implementation, the backlight module further includes a pressing frame connected to the housing, the pressing frame and the light guide plate are arranged along a first direction, and the reflective film is provided on a side of the pressing frame facing the LED light source.

[0014] The pressing frame is usually used to press the light guide plate and multiple optical film layers between the light guide plate and the liquid crystal panel into the housing.

[0015] In this possible implementation, the reflective film is directly set on the side of the pressure frame facing the LED light source, that is, the reflective film, multiple optical film layers between the light guide plate and the liquid crystal panel share the pressure frame, and there is no need to set up an additional supporting structure for supporting the reflective film, which is conducive to simplifying the structure of the backlight module.

[0016] According to the first aspect, in a possible implementation, the light guide plate further includes a light incident surface, the light incident surface is connected between the first surface and the second surface, and the light incident surface is tilted relative to the first direction.

[0017] In this possible implementation, compared with the arrangement in which the light incident surface is parallel to the first direction, the area of ​​the light incident surface can be increased, which is beneficial to increasing the probability of light emitted by the light emitting unit being coupled to the light incident surface.

[0018] According to the first aspect, in a possible implementation manner, the first surface and the second surface are parallel to each other, the angle between the first surface and the light incident surface is an acute angle, and the angle between the second surface and the light incident surface is an obtuse angle.

[0019] In this possible implementation, the first surface and the second surface are parallel to each other, the angle between the first surface and the light-entering surface is acute, and the angle between the second surface and the light-entering surface is obtuse. In other words, the cross-section of the light guide plate is trapezoidal, and the cross-section, the first direction, and the second direction are parallel. The light guide plate can be a one-piece structure, for example, formed in one piece through an injection molding process. The one-piece structure of the light guide plate simplifies the structure of the light guide plate and simplifies the assembly and disassembly of the backlight module and display screen.

[0020] According to the first aspect, in one possible implementation, a light guide plate includes a main body and a wedge, the wedge and the main body being arranged along a second direction. The main body includes a first exit surface, a second surface, and a first transmission surface. The first exit surface and the second surface are arranged opposite each other along the first direction, and the first transmission surface is connected between the first exit surface and the second surface. The wedge includes a second exit surface, a light incident surface, and a second transmission surface. The first exit surface, the light incident surface, and the third transmission surface are connected end to end in sequence. The first exit surface and the second exit surface are joined in the second direction to form a first surface, and the first transmission surface and the second transmission surface are abutted.

[0021] In this possible implementation, the light guide plate includes a main body and a wedge that are separately arranged. The main body can adopt a commonly used long strip light guide plate, plus a simple triangular wedge structure. In other words, a simple improvement is made to the commonly used long strip light guide plate, the mold structure of the light guide plate is simplified, the manufacture of the light guide plate is facilitated, and it is beneficial to reduce the manufacturing cost of the backlight module.

[0022] According to the first aspect, in a possible implementation manner, the light incident surface is parallel to the substrate.

[0023] In this possible implementation, the light-incoming surface is arranged parallel to the substrate, which is beneficial to increasing the light coupling area between the light-incoming surface and the light-emitting unit, thereby increasing the light energy coupling efficiency of the light emitted by the LED light source coupled into the light guide plate.

[0024] According to the first aspect, in a possible implementation manner, an inner wall of the housing is formed with an inclined surface, and the substrate is installed on the inclined surface.

[0025] In this possible implementation, the inner wall of the housing forms an inclined surface, which is used to install and position the LED light source, thereby improving the positioning accuracy of the LED light source and the optical coupling accuracy between the LED light source and the light guide plate. In addition, because the substrate is directly mounted on the inclined surface formed on the inner wall of the housing, there is no need for a separate bracket or positioning structure to support the substrate, which helps to simplify the structure of the backlight module.

[0026] In a second aspect, an embodiment of the present application provides a display screen, comprising a liquid crystal panel and a backlight module provided according to any one of the implementation methods of the first aspect, wherein the liquid crystal panel and the backlight module are stacked along a first direction.

[0027] The LED light source is tilted relative to the first direction, reducing the size of the LED light source in the first direction. This reduced size helps reduce the thickness of the light guide plate in the first direction, thereby reducing the thickness of the backlight module in the first direction. This reduced thickness of the backlight module in the first direction reduces the overall thickness of the display, contributing to the development of thinner and lighter displays.

[0028] In a third aspect, an embodiment of the present application provides a vehicle, comprising a display screen according to the second aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] FIG1 is a schematic diagram of the interior of a vehicle provided by the present application;

[0030] FIG2 is a cross-sectional schematic diagram of a display screen provided in one embodiment of the present application;

[0031] 3 is a partial cross-sectional schematic diagram of a backlight module provided by the first embodiment of the present application when the light guide plate is an integrated structure;

[0032] FIG4 is a schematic diagram of a planar structure of a possible LED light source of the present application;

[0033] FIG5 is a schematic diagram of a planar structure of a possible LED light source of the present application;

[0034] 6 is a partial cross-sectional schematic diagram of a backlight module provided by the first embodiment of the present application when the light guide plate has a split structure;

[0035] FIG7 is a partial cross-sectional schematic diagram of a backlight module provided in a second embodiment of the present application;

[0036] FIG8 is a schematic diagram of a stacked structure of a backlight module provided in one embodiment of the present application.

[0037] Reference numerals: 100 - vehicle; 101 - vehicle body; 103 - display screen; 20 - backlight module; Z - first direction; X - second direction; 21 - housing; 211 - inclined surface; 22-LED light source; 221-substrate; 222-light-emitting unit; 2222-light-emitting surface; 23-light guide plate; 231-first surface; 232-second surface; 233-light-incoming surface; 234-main body; 2341-first emitting surface; 2343-first transmission surface; 235-wedge; 2351-second emitting surface; 2353-second transmission surface; 25-diffusion film; 26-brightness enhancement film; 27-dual brightness enhancement film; 28-pressing frame; 281-through hole; 29-reflective film; 40-liquid crystal panel; 41-first polarizer; 42-first substrate; 43-device array layer; 44-liquid crystal layer; 45-color filter layer; 46-second substrate; 47-second polarizer. DETAILED DESCRIPTION

[0038] Referring to FIG1 , one embodiment of the present application provides a vehicle 100 , which includes a vehicle body 101 and a display screen 103 disposed on the vehicle body 101 . FIG1 exemplarily illustrates that the center console and seats of the vehicle 100 are equipped with the display screen 103 . For example, the display screen 103 is disposed on a seat with the display surface of the display screen 103 facing the rear of the vehicle 100 . For example, while riding in the vehicle 100 , rear passengers can watch movies, browse the web, watch on-demand videos, or play games, among other entertainment options, using the display screen 103 disposed on the front seat. It is understood that the display screen 103 can also be mounted on the bulkhead of the cabin of the vehicle body 101 .

[0039] Referring to FIG. 2 , display screen 103 is a liquid crystal display (LCD). Display screen 103 includes a backlight module 20 and a liquid crystal panel 40 stacked along a first direction Z. Backlight module 20 provides backlight for liquid crystal panel 40. The side of liquid crystal panel 40 facing away from backlight module 20 is used to display image information.

[0040] It can be understood that the present application does not limit the application field of the display screen 103, that is, the present application does not limit the application of the display screen to the vehicle 100. The display screen 103 can also be applied to mobile phones, tablet computers, laptops, ultra-mobile personal computers (UMPCs), handheld computers, walkie-talkies, netbooks, POS machines, personal digital assistants (PDAs), driving recorders, security equipment, and other mobile terminals, fixed terminals, or foldable terminals with display screens.

[0041] Compared with an organic light-emitting diode (OLED) display screen, an LCD has a backlight module, which makes the LCD have a disadvantage of being thicker, which is not conducive to the application of the LCD screen, for example, when it is installed on the vehicle 100.

[0042] Based on this, please refer to Figure 3. The backlight module 20 provided in the first embodiment of the present application includes a housing 21, an LED light source 22, and a light guide plate 23. The LED light source 22 and the light guide plate 23 can both be accommodated in the housing 21. The LED light source 22 and the light guide plate 23 are arranged along the second direction X, that is, the LED light source 22 is arranged on one side of the light guide plate 23 in the second direction X so that light enters from one side of the light guide plate 23 in the second direction. Since the backlight module 20 adopts a side-entry type, it is beneficial to reduce the thickness of the backlight module 20 in the first direction Z, thereby reducing the overall thickness of the display screen 103 in the first direction Z.

[0043] The light guide plate 23 includes a first surface 231 and a second surface 232 disposed opposite to each other along a first direction Z. The first surface 231 faces the liquid crystal panel 40 .

[0044] The LED light source 22 includes a substrate 221 and a light-emitting unit 222 provided on the substrate 221. The substrate 221 is mounted on the housing 21. The normal of the substrate 221 is arranged toward the first surface 231. The angle between the plane of the side of the substrate 221 facing away from the light-emitting unit 222 and the first direction Z is greater than 0° and less than 90°. The light-emitting unit 222 has a light-emitting surface 2222 for emitting light. The light-emitting surface 2222 can be a plane, and the light-emitting surface 2222 is roughly parallel to the substrate 221. It is understood that the light-emitting surface 2222 can also include a curved surface and / or a flat surface. The present application does not limit the shape of the light-emitting surface 2222. It is understood that the number of LED light sources 22 can be one or more.

[0045] The light guide plate occupies a significant portion of the backlight module's thickness. If the light guide plate's thickness is reduced directly, the thickness of the LED light source placed on one side of the light guide plate must also be reduced. Reducing the size of the LED light source may affect the amount of light it emits.

[0046] In the backlight module 20 provided in the present application, the angle A between the plane of the side of the substrate 221 facing away from the light-emitting unit 222 and the first direction Z is greater than 0° and less than 90°, that is, the substrate 221 is tilted relative to the first direction Z. This causes the LED light source 22 to be tilted relative to the first direction Z as a whole, thereby reducing the size of the LED light source 22 in the first direction Z. Since the size of the LED light source 22 in the first direction Z is reduced, the thickness of the light guide plate 23 and the backlight module 20 in the first direction Z is reduced, which facilitates the development of a lighter and thinner backlight module 20 and expands the application range of the backlight module 20 and the display screen 103.

[0047] Since the LED light source 22 is only tilted relative to the first direction Z, the size, specifications, structure, etc. of the LED light source 22 remain unchanged. While reducing the thickness of the light guide plate 23, the light output of the LED light source 22 can be guaranteed to remain unchanged, which is beneficial to improving the utilization rate of light energy.

[0048] In addition, the substrate 221 is installed on the shell 21 instead of on the light guide plate 23, so there is no need to set a structure for installing the LED light source 22 on the light guide plate 23, such as a mounting groove. This simplifies the structure of the light guide plate 23 and facilitates the manufacture of the light guide plate 23.

[0049] In some embodiments of the present application, an inclined surface 211 is formed on the inner wall of the housing 21, and the substrate 221 is installed on the inclined surface 211. The inclined surface 211 is used to install and position the LED light source 22, which is beneficial to improving the positioning accuracy of the LED light source 22 and improving the optical coupling accuracy between the LED light source 22 and the light guide plate 23. In addition, since the inclined surface 211 is directly formed on the inner wall of the housing 21 to install the substrate 221, there is no need to set up an additional bracket or positioning structure to support the substrate 221, which is beneficial to simplify the structure of the backlight module 20. It can be understood that the inclined surface 211 of the housing 21 can be omitted, and it is sufficient to achieve that the angle A between the plane where the side of the substrate 221 facing away from the light-emitting unit 222 is located and the first direction Z is greater than 0° and less than 90°.

[0050] The light guide plate 23 also includes a light-incoming surface 233, a first surface 231, and a second surface 232. The light-incoming surface 233 is connected between the first surface 231 and the second surface 232. The light-incoming surface 233 is used to input light emitted by the LED light source 22. Light entering the light guide plate 23 through the light-incoming surface 233 is then emitted from the first surface 231 and incident on the liquid crystal panel 40. The first direction Z is the thickness direction of the backlight module 20.

[0051] In some embodiments of the present application, the light-entering surface 233 is tilted relative to the first direction Z. Compared with a configuration parallel to the first direction Z, the area of ​​the light-entering surface 233 can be increased, which is beneficial for increasing the probability of light emitted by the light-emitting unit 222 being coupled to the light-entering surface 233 .

[0052] In some embodiments of the present application, please refer to Figure 3 again. The cross-section of the light guide plate 23 can be roughly trapezoidal. The cross-section is parallel to the first direction Z and the second direction X. The first surface 231 and the second surface 232 are parallel to each other, the angle between the first surface 231 and the light-entering surface 233 is an acute angle, and the angle between the second surface 232 and the light-entering surface 233 is an obtuse angle. The light guide plate 23 can be an integral structure. For example, the light guide plate 23 is integrally formed by an injection molding process. The light guide plate 23 is an integral structure, which makes the structure of the light guide plate 23 simple, and simplifies the assembly and disassembly of the backlight module 20 and the display screen 103.

[0053] In some embodiments of the present application, as shown in FIG4 , the light guide plate 23 may be a split structure. The light guide plate 23 includes a main body 234 and a wedge 235. The wedge 235 and the main body 234 are arranged along the second direction X. The main body 234 is generally rectangular, that is, it is generally in the shape of a long strip. The main body 234 includes a first emitting surface 2341, a second surface 232, and a first transmissive surface 2343. The first emitting surface 2341 and the second surface 232 are arranged opposite each other along the first direction Z. The first transmissive surface 2343 is connected between the first emitting surface 2341 and the second surface 232. The wedge 235 includes a second emitting surface 2351, a light-incoming surface 233, and a second transmissive surface 2353. The first emitting surface 2341, the light-incoming surface 233, and the second transmissive surface 2353 are connected end to end. The second emitting surface 2351, the light-incoming surface 233, and the second transmissive surface 2353 form a trihedron. The first emission surface 2341 and the second emission surface 2351 are spliced ​​together to form the first surface 231 in the second direction X. The first transmission surface 2343 and the second transmission surface 2353 are in contact with each other.

[0054] The light guide plate 23 includes a main body 234 and a wedge 235, which are separately arranged. The main body 234 can be a conventional long strip light guide plate. Compared to the arrangement of the LED light source substrate parallel to the first direction, the use of a conventional long strip light guide main body 234 with a simple wedge 235, in other words, the use of a conventional long strip light guide plate with a simple modification, helps simplify the structure of the backlight module 20 and reduce the manufacturing cost of the backlight module 20.

[0055] In some embodiments of the present application, the light-incoming surface 233 is arranged in parallel with the light-emitting surface 2222 , so as to increase the light energy coupling efficiency of the light emitted by the LED light source 22 into the light guide plate 23 .

[0056] It is understood that the present application does not limit the structure of the light guide plate 23, as long as the light guide plate 23 can receive the light emitted by the LED light source 22 and guide the light to the liquid crystal panel 40. For example, the light guide plate 23 may include a plurality of light guide units connected together.

[0057] The backlight module 20 may further include a diffuser 25, a brightness enhancement film (BEF) 26, a double brightness enhancing film (DBEF) 27, and a bezel 28. The light guide plate 23, the diffuser 25, the brightness enhancement film 26, the double brightness enhancement film 27, the bezel 28, and the liquid crystal panel 40 are stacked in sequence along the first direction Z. The diffuser 25 is used to diffuse light emitted from the first surface 231 of the light guide plate 23 to form a uniform surface light source. The brightness enhancement film 26 is also called a prism sheet or a light-concentrating sheet. The brightness enhancement film 26 includes a prism layer. When the prism layer passes through the fine prism structure on its surface, it controls the light intensity distribution through refraction, total reflection, and light accumulation, thereby concentrating the scattered light toward the front and recycling the unused light outside the viewing angle through light reflection, thereby reducing light loss and improving the overall luminance and uniformity of the display screen 103, thereby increasing the brightness of the display screen 103 and controlling the viewing angle. The dual brightness enhancement film 27 is a thin film reflective polarizer used to increase brightness across the entire viewing area of ​​the display screen 103. A press frame 28 is located between the dual brightness enhancement film 27 and the liquid crystal panel 40. It is used to secure the dual brightness enhancement film 27, the diffuser film 25, and the light guide plate 23 against the housing 21, thereby reducing the possibility of these films moving relative to the housing 21. The press frame 28 is provided with a through hole 281, which is used to guide light emitted from the dual brightness enhancement film 27 to the liquid crystal panel 40 for transmission.

[0058] The light emitted from the light emitting unit 222 is directly coupled into the light guide plate 23 , then passes through the diffusion film 25 , the brightness enhancement film 26 , and the dual brightness enhancement film 27 into the liquid crystal panel 40 , and is finally displayed by the liquid crystal panel 40 .

[0059] The diffusion film 25 , the brightness enhancement film 26 , and the dual brightness enhancement film 27 are all optical film layers disposed on the light guide plate 23 . The present application does not limit the number and type of the optical film layers of the backlight module 20 .

[0060] For ease of description, the angle A between the surface of the substrate 221 facing away from the light-emitting unit 222 and the first direction Z is referred to as the tilt angle, and the end of the light guide plate 23 where the light-incoming surface 233 is located is referred to as the front end. Without considering the light energy loss of the light guide plate 23, the ratio of the light energy received at the front end to the total light energy of the light source is referred to as the front end coupling efficiency.

[0061] Using Tracepro software, we simulated the light entering the backlight module 20. The thicknesses of the diffusion film 25, brightness enhancement film 26, and dual brightness enhancement film 27 were kept constant, while the thickness of the light guide plate 23 varied depending on the tilt angle. This revealed the relationship between the tilt angle and the efficiency of coupling into the light guide plate 23 (as shown in Table 1), as well as the relationship between the tilt angle, the light guide plate 23, and the total thickness of the backlight module 20 (as shown in Table 2). The amount of light entering the front end remained the same at different tilt angles. Within the tilt angle range of [0°, 30°], the front end coupling efficiency reached 97.78%.

[0062] Table 1 Relationship between tilt angle and efficiency of coupling into light guide plate

[0063] Table 2 Relationship between tilt angle, total thickness of light guide plate and backlight module

[0064] Because the LED light source 22 is tilted relative to the first direction Z, and the light guide plate 23 is provided with a light inlet surface 233 parallel to the light outlet surface 2222, the thickness of the light guide plate 23 in the first direction Z can be reduced while ensuring that the front coupling efficiency of the backlight module 20 reaches 97.78%. As shown in Tables 1 and 2, when the tilt angle is 30° and the tilt angle is 0°, the overall thickness of the backlight module 20 can be reduced by approximately 10%.

[0065] The present application does not limit the structural form of the LED light source 22. In some embodiments of the present application, as shown in FIG5 , the light-emitting unit 222 is a lamp bead, and there are multiple light-emitting units 222, which are arranged in an array on the substrate 221. It is understood that the number of the light-emitting unit 222 can be one.

[0066] In some embodiments of the present application, as shown in FIG6 , the light emitting unit 222 may also be a light bar, which is roughly in the shape of a long strip, and the light emitting unit 222 extends along the length direction of the substrate 221 .

[0067] Please refer to Figure 7. The structure of the backlight module 20 provided in the second embodiment of the present application is roughly the same as the structure of the backlight module 20 provided in the first embodiment of the present application. The difference is that the backlight module 20 also includes a reflective film 29, which is used to reflect light incident on the reflective film 29 to the light guide plate 23.

[0068] Part of the light emitted by LED light source 22 is directly coupled into light guide plate 23, while the remaining part is reflected by reflective film 29 and then enters light guide plate 23, thereby reducing light loss and improving light energy utilization. The light coupled into light guide plate 23 then passes through light guide plate 23, diffuser film 25, brightness enhancement film 26, and dual brightness enhancement film 27, and enters liquid crystal panel 40 for display.

[0069] In some embodiments of the present application, the light-incoming surface 233 of the light guide plate 23 is parallel to the first direction Z. The light guide plate 23 can be a conventionally long strip. Compared to the arrangement of the LED light source substrate parallel to the first direction, the present application merely tilts the LED light source 22 relative to the first direction Z and adds a reflective film 29. This allows the backlight module 20 to be thinned and achieves higher optical efficiency.

[0070] The reflective film 29 and the LED light source 22 are aligned along the first direction Z. In other words, the reflective film 29 is positioned above the LED light source 22 in the first direction Z. The reflective film 29 is planar and perpendicular to the first direction Z. Aligning the reflective film 29 and the LED light source 22 along the first direction Z and being planar reduces the space occupied by the reflective film 29. It should be understood that the present application does not limit the reflective film 29 to a planar surface; the reflective film 29 may also be curved to increase the surface area within a limited space.

[0071] The reflective film 29 is disposed on the side of the press frame 28 facing the LED light source 22. The reflective film 29 and the dual brightness enhancement film 27 are aligned along the second direction X. Disposing the reflective film 29 directly on the press frame 28 without requiring a separate support structure for the reflective film 29 simplifies the structure of the backlight module 20. The reflective film 29 can be formed on the side of the press frame 28 facing the LED light source 22 by plating, coating, or other methods. This application does not limit the connection method between the reflective film 29 and the press frame 28.

[0072] For the convenience of description, the angle between the side of the substrate 221 facing away from the light-emitting unit 222 and the first direction Z is called the tilt angle, and the end of the light guide plate 23 where the light-entering surface 233 is located is called the front end. Without considering the light energy loss of the light guide plate 23, the ratio between the light energy received by the front end and the total light energy of the light source is the front end coupling efficiency. The light entering the backlight module 20 is simulated and calculated according to the software Tracepro, wherein the thickness of the diffusion film 25, the brightness enhancement film 26, and the dual brightness enhancement film 27 are set to remain unchanged, and the thickness of the light guide plate 23 is set to different according to the different tilt angles. In this way, the relationship between the tilt angle and the efficiency of coupling into the light guide plate 23 (as shown in Table 3) and the relationship between the tilt angle, the light guide plate 23 and the total thickness of the backlight module 20 (as shown in Table 4) can be obtained. At different tilt angles, the light energy entering the front end is the same.

[0073] When the tilt angle range is [0°, 20°], the front-end coupling efficiency can reach over 90%, as shown in Table 3. At a tilt angle of 25°, the tilted LED light source 22 may interfere with the assembly between the light guide plate 23 and the housing 21. Therefore, in some embodiments of the present application, the angle between the plane of the substrate 221 facing away from the light-emitting unit 222 and the first direction Z can be, but is not limited to, [0°, 20°] to avoid structural interference between the substrate 221 and the light guide plate 23 and the housing 21 due to the tilted arrangement, thereby facilitating assembly.

[0074] Table 3 Relationship between tilt angle and efficiency of coupling into light guide plate

[0075] Table 4 Relationship between tilt angle, total thickness of light guide plate and backlight module

[0076] By adding a reflective film 29 above the tilted LED light source 22, the probability of light emitted by the LED light source 22 entering the light guide plate 23 is increased, thereby improving the front-end coupling efficiency. As shown in Table 4, when the tilt angle is 20° and 0°, the overall thickness of the backlight module 20 can be reduced by 5%.

[0077] Referring to Figure 8 , the liquid crystal panel 40 includes a first polarizer 41, a first substrate 42, a device array layer 43, a liquid crystal layer 44, a color filter layer 45, a second substrate 46, and a second polarizer 47, which are stacked in sequence along a first direction Z. The first polarizer 41 is positioned between the backlight module 20 and the first substrate 42 in the first direction Z. The first polarizer 41 is used to convert light emitted by the backlight module 20 into polarized light. The second polarizer 47 is used to interpret the polarized light electrically modulated by the liquid crystal layer 44, generating light and dark contrast, thereby producing a display image.

[0078] The first substrate 42 and the second substrate 46 are both made of light-transmitting materials. The color filter layer 45, also known as the color filter (CF), is used to pass light within a specific wavelength range. The device array layer 43 includes a plurality of thin film transistors (TFTs) arranged in an array.

[0079] Device array layer 43 controls the deflection direction of the liquid crystals in liquid crystal layer 44, while color filter layer 45 filters light. The device array layer 43, liquid crystal layer 44, and color filter layer 45 work together to enable display screen 103 to display. Because liquid crystals transmit light, visible light can pass through liquid crystal layer 44.

[0080] The color filter layer 45 may include a black matrix (BM) and a plurality of color resist blocks arranged alternately with the black matrix. The plurality of color resist blocks include red (R) color resist blocks, green (G) color resist blocks, and blue (B) color resist blocks. In one embodiment, the plurality of color resist blocks may also include white (W) color resist blocks or yellow (Y) color resist blocks.

[0081] The liquid crystal layer 44 is located between the color filter layer 45 and the device array layer 43. The color filter layer 45 can be formed on a second substrate 46, and together with the second substrate 46, it forms the color filter substrate 221. The device array layer 43 can be formed on a first substrate 42, and together with the first substrate 42, it forms the array substrate 221. When manufacturing the liquid crystal panel 40, the array substrate 221 and the color filter substrate 221 are first formed separately. The array substrate 221 and the color filter substrate 221 are then aligned. Then, liquid crystal is filled between the array substrate 221 and the color filter substrate 221 to form the liquid crystal layer 44.

[0082] The liquid crystal panel 40 also includes an outer frame, which houses the first polarizer 41, first substrate 42, device array layer 43, liquid crystal layer 44, color filter layer 45, second substrate 46, and second polarizer 47. The outer frame is bonded to the housing 21 along the first direction Z. The outer frame protects the first polarizer 41, first substrate 42, device array layer 43, liquid crystal layer 44, color filter layer 45, second substrate 46, and second polarizer 47 of the liquid crystal panel 40.

[0083] In summary, in the absence of conflict, the first embodiment and the second embodiment of the present application can be combined with each other. For example, in the first embodiment, a reflective film 29 can be provided on the side of the pressing frame 28 facing the LED light source 22 .

[0084] It should be understood that expressions such as "include" and "may include" used in this application indicate the existence of the disclosed functions, operations, or constituent elements, and do not limit one or more additional functions, operations, and constituent elements. In this application, terms such as "include" and / or "have" may be interpreted as indicating specific characteristics, numbers, operations, constituent elements, components, or combinations thereof, but may not be interpreted as excluding the existence or possibility of adding one or more other characteristics, numbers, operations, constituent elements, components, or combinations thereof.

[0085] In addition, in this application, the expression "and / or" includes any and all combinations of the associated listed words. For example, the expression "A and / or B" may include A, may include B, or may include both A and B.

[0086] In this application, expressions including ordinal numbers such as "first" and "second" may modify various elements. However, such elements are not limited by the above expressions. For example, the above expressions do not limit the order and / or importance of the elements. The above expressions are only used to distinguish one element from other elements. For example, a first user device and a second user device indicate different user devices, even though the first user device and the second user device are both user devices. Similarly, without departing from the scope of this application, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element.

[0087] When a component is referred to as being "connected" or "accessed" to another component, it should be understood that the component is not only directly connected to or accessed to the other component, but also that another component may exist between the component and the other component. On the other hand, when a component is referred to as being "directly connected to" or "directly accessed" to another component, it should be understood that no component exists between them.

[0088] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A backlight module, characterized in that: The backlight module includes a housing, a light guide plate and an LED light source, the light guide plate includes a first surface and a second surface arranged opposite to each other along a first direction, the LED light source and the light guide plate are arranged along a second direction, and the first direction is perpendicular to the second direction; The LED light source includes a substrate and a light-emitting unit arranged on the substrate. The substrate is installed on the shell, the normal of the substrate is set toward the first surface, and the angle between the plane of the substrate facing away from the light-emitting unit and the first direction is greater than 0° and less than 90°.

2. The backlight module according to claim 1, wherein: The backlight module further includes a reflective film, and the reflective film is used to reflect light incident on the reflective film to the light guide plate.

3. The backlight module according to claim 2, wherein: The reflective film and the LED light source are arranged along the first direction. The reflective film is a plane and is perpendicular to the first direction.

4. The backlight module according to claim 2 or 3, wherein: The backlight module further includes a pressing frame connected to the housing. The pressing frame and the light guide plate are arranged along the first direction. The reflective film is arranged on a side of the pressing frame facing the LED light source.

5. The backlight module according to any one of claims 1 to 4, characterized in that: The light guide plate further includes a light-incoming surface connected between the first surface and the second surface, and the light-incoming surface is tilted relative to the first direction.

6. The backlight module according to claim 5, characterized in that: The first surface and the second surface are parallel to each other. The angle between the first surface and the light incident surface is an acute angle, and the angle between the second surface and the light incident surface is an obtuse angle.

7. The backlight module according to claim 5, wherein: The light guide plate includes a main body and a wedge, the wedge and the main body are arranged along the second direction, the main body includes a first emitting surface, the second surface and a first transmission surface, the first emitting surface and the second surface are arranged opposite to each other along the first direction, and the first transmission surface is connected between the first emitting surface and the second surface; The wedge block includes a second emission surface, a light incident surface and a second transmission surface. The first emission surface, the light incident surface and the third transmission surface are connected end to end in sequence. The first emission surface and the second emission surface are spliced ​​into the first surface in the second direction. The first transmission surface and the second transmission surface are in contact with each other, and the first transmission surface and the second transmission surface are both parallel to the first direction.

8. The backlight module according to any one of claims 5 to 7, wherein: The light incident surface is parallel to the substrate.

9. The backlight module according to any one of claims 1 to 8, wherein: An inner wall of the housing is formed with an inclined surface, and the substrate is mounted on the inclined surface.

10. A display screen, characterized in that: The display screen includes a liquid crystal panel and a backlight module according to any one of claims 1 to 9, and the liquid crystal panel and the backlight module are stacked along a first direction.

11. A vehicle, characterized in that: Comprising the display screen according to claim 10.

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