Backlight module and display device

Abstract

The backlight module comprises a back plate, the back plate comprises a bottom plate and a side plate, the side plate is connected to the edge of the bottom plate, and the side plate and the bottom plate form a containing space; the middle frame comprises a frame body and an extending part, the frame body is located on the side, away from the containing space, of the side plate, and the extending part is connected with the frame body and extends to the containing space; the light guide plate is located in the containing space and comprises a plate body and a limiting boss, and the limiting boss is connected to the edge of the plate body and protrudes out of the surface of the side, away from the bottom plate, of the plate body; the optical film is located on the side, away from the bottom plate, of the plate body, the limiting boss is configured to limit the optical film, the extension part comprises a shading part, the shading part is located on the side, close to the bottom plate, of the extension part, connected with the extension part and located on the side, away from the side plate, of the limiting boss, and at least part of a gap between the extension part and the optical film is filled with the shading part; the first surface of the shading portion away from the frame body and the second surface of the extension portion away from the frame body are arranged at intervals in the first direction.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of display, and in particular, to a backlight module and a display device. BACKGROUND

[0002] In recent years, with the continuous improvement of people's awareness of driving safety, vehicle display screens have developed rapidly in the field of automobile electronics, and automobile manufacturers have increasingly high quality requirements for vehicle display screens. In a liquid crystal display (LCD), a backlight unit (BLU) is needed to provide a light source for the LCD to display images. In the related art, in order to meet the positioning requirements of the optical film in the backlight module, a limiting boss is usually arranged at the edge of the light guide plate to limit the optical film. However, the abnormal bright light refracted by the limiting boss may pass through the gap between the optical film and the middle frame, and an abnormal uneven picture may be generated on the visual angle picture observed by the human eye.

[0003] The above information disclosed in this section is only for the understanding of the background of the inventive concept of the present disclosure, and therefore, the above information can include information that does not constitute the prior art. UTILITY MODEL CONTENT

[0004] To solve at least one aspect of the above problem, embodiments of the present disclosure provide a backlight module and a display device.

[0005] In one aspect of the embodiments of the present disclosure, a backlight module is provided, comprising:

[0006] a back plate comprising a bottom plate and a side plate, the side plate being connected to an edge of the bottom plate and forming a containing space with the bottom plate;

[0007] a middle frame comprising a frame main body and an extension part, the frame main body being located on a side of the side plate away from the containing space, and the extension part being connected to the frame main body, located on a side of the side plate away from the bottom plate, and extending to the containing space;

[0008] a light guide plate located in the containing space, the light guide plate comprising a plate main body and a limiting boss, the limiting boss being connected to an edge of the plate main body and protruding from a surface of the plate main body away from the bottom plate; and

[0009] an optical film located on a side of the plate main body away from the bottom plate, the limiting boss being configured to limit the optical film,

[0010] wherein the extension part comprises:

[0011] The light shielding part is located on one side of the extension part close to the bottom plate and connected with the extension part, and is located on one side of the limiting boss away from the side plate, and the light shielding part fills at least part of the gap between the extension part and the optical film piece; the first surface of the light shielding part away from the frame body side and the second surface of the extension part away from the frame body side are arranged in the first direction, and the first direction is the extension direction of the extension part away from the frame body.

[0012] According to some exemplary embodiments, wherein the orthographic projection of the light shielding part on the bottom plate at least partially surrounds the orthographic projection of the limiting boss on the bottom plate, the orthographic projection of the light shielding part on the bottom plate does not overlap with the orthographic projection of the limiting boss on the bottom plate; the orthographic projection of the light shielding part on the bottom plate is located within the orthographic projection of the optical film piece on the bottom plate.

[0013] According to some exemplary embodiments, wherein the first surface of the light shielding part away from the frame body side and the second surface of the extension part away from the frame body side have a first distance in the first direction, the third surface of the light shielding part close to the frame body side and the fourth surface of the limiting boss away from the frame body side have a second distance in the first direction, and the first distance is greater than the second distance.

[0014] According to some exemplary embodiments, wherein the fifth surface of the light shielding part close to the bottom plate and the sixth surface of the optical film piece away from the bottom plate have a third distance in the second direction, and the third distance ranges from 0.05 to 0.15 mm.

[0015] According to some exemplary embodiments, wherein the cross section of the light shielding part along the light emitting direction of the backlight module is rectangular; and / or

[0016] The thickness of the light shielding part in the light emitting direction of the backlight module is 0.15-0.25 mm.

[0017] According to some exemplary embodiments, wherein the first surface of the light shielding part away from the frame body side is connected with the fifth surface of the light shielding part close to the bottom plate and the third surface of the light shielding part close to the frame body side, and the corner formed by the first surface and the fifth surface is a rounded corner; and / or, the corner formed by the third surface and the fifth surface is a rounded corner.

[0018] According to some exemplary embodiments, wherein the fifth surface of the light shielding part close to the bottom plate is a bevel relative to the sixth surface of the optical film piece away from the bottom plate;

[0019] The thickness of the light shielding portion in the light emitting direction of the backlight module gradually decreases in a first direction away from the frame body.

[0020] According to some exemplary embodiments, the middle frame is a plastic frame, and the light shielding portion is integrally formed with the middle frame.

[0021] According to some exemplary embodiments, a third surface of the light shielding portion, which is close to the side of the frame body, and a fourth surface of the limiting boss, which is away from the side of the frame body, are at least partially coplanar, and the third surface and the fourth surface are not in contact.

[0022] According to some exemplary embodiments, the extension portion includes:

[0023] a groove located on the side of the extension portion close to the bottom plate, the groove being located on the side of the light shielding portion close to the frame body, and at least part of the limiting boss being located in the groove.

[0024] According to some exemplary embodiments, a seventh surface of the groove, which is away from the side of the frame body, and a third surface of the light shielding portion, which is close to the side of the frame body, are connected.

[0025] According to some exemplary embodiments, the middle frame is a metal frame, and the middle frame includes:

[0026] a light shielding tape located on the side of the extension portion close to the bottom plate, the light shielding portion being attached to the light shielding tape, and a normal projection of the light shielding portion on the bottom plate being located in a normal projection of the light shielding tape on the bottom plate.

[0027] According to some exemplary embodiments, a fourth distance in the first direction is provided between an eighth surface of the light shielding tape, which is close to the side of the frame body, and a fourth surface of the limiting boss, which is away from the side of the frame body.

[0028] The eighth surface of the light shielding tape and the third surface of the light shielding portion, which is close to the side of the frame body, are at least partially coplanar.

[0029] Another aspect of the embodiments of the present disclosure provides a display device including the backlight module according to the above. BRIEF DESCRIPTION OF DRAWINGS

[0030] Other objects and advantages of the present disclosure will be more fully apparent in view of the ensuing description of the present disclosure when read in conjunction with the drawings.

[0031] Figure 1 A cross-sectional view of a backlight module in the related art is schematically shown;

[0032] Figure 2 A cross-sectional view of a backlight module with light shielding improvement in the related art is schematically shown;

[0033] Figure 3 A plan view of a backlight module according to some example embodiments of the present disclosure is schematically shown;

[0034] Figure 4 A cross-sectional view of a backlight module according to some example embodiments of the present disclosure is schematically shown;

[0035] Figure 5 A cross-sectional view of a backlight module according to some comparative embodiments of the present disclosure is schematically shown;

[0036] Figure 6 A cross-sectional view of a backlight module according to some example embodiments of the present disclosure is schematically shown;

[0037] Figure 7 A cross-sectional view of a frame and a light shielding portion in a backlight module according to some example embodiments of the present disclosure is schematically shown;

[0038] Figure 8 A cross-sectional view of a frame and a light shielding portion in a backlight module according to some example embodiments of the present disclosure is schematically shown;

[0039] Figure 9 A cross-sectional view of a backlight module according to some example embodiments of the present disclosure is schematically shown;

[0040] Figure 10 A cross-sectional view of a backlight module according to some example embodiments of the present disclosure is schematically shown;

[0041] Figure 11 A cross-sectional view of a backlight module according to some comparative embodiments of the present disclosure is schematically shown;

[0042] Figure 12 A structural schematic view of a display device provided according to an embodiment of the present disclosure is schematically shown.

[0043] It should be noted that, for the sake of clarity, the size of a layer, structure or region can be exaggerated or reduced in the drawings used to describe embodiments of the present disclosure, i.e., these drawings are not drawn according to the actual scale. DETAILED DESCRIPTION

[0044] The technical solutions of the present disclosure will be further described in detail below by way of examples, with reference to the accompanying drawings. In the description, identical or similar reference numerals indicate identical or similar components. The following description of the embodiments of the present disclosure with reference to the accompanying drawings is intended to explain the general inventive concept of the present disclosure, and should not be construed as a limitation of the present disclosure.

[0045] Additionally, in the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of embodiments of the present disclosure. However, it will be apparent to one skilled in the art that one or more embodiments can be practiced without these specific details.

[0046] It will be understood that, although the terms first, second, etc. can be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of example embodiments. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0047] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0048] In this document, unless otherwise explicitly stated and limited, the term "connected" should be construed broadly, for example, "connected" can be a fixed connection, or a detachable connection, or integral; can be directly connected, or indirectly connected through an intermediate medium.

[0049] For ease of description, spatial relationship terms, such as "upper", "lower", "left", "right", and the like, can be used herein to describe the relationship between one element or feature and another element or feature as shown in the drawings. It will be understood that the spatial relationship terms are intended to encompass different orientations of the device in use or operation, in addition to the orientation depicted in the drawings. For example, if the device in the drawings is turned over, an element described as "below" or "under" another element or feature would then be oriented "above" or "over" the other element or feature. Furthermore, the terms X-axis, Y-axis, and Z-axis do not limit to three axes of a rectangular coordinate system, and can be interpreted in a broader sense. For example, the X-axis, Y-axis, and Z-axis can be perpendicular to each other, or can represent different directions that are not perpendicular to each other.

[0050] It will be understood by those skilled in the art that, herein, unless otherwise specified, the expression "height" or "thickness" refers to the dimension of each structure along the surface perpendicular to the back light module, i.e. along the light emitting direction of the back light module, or the dimension along the normal direction of the back light module.

[0051] With the wide application of in-vehicle floating screens, there is an increasing demand for in-vehicle narrow frames. However, the film assembly positioning of the in-vehicle backlight usually relies on the light guide plate limiting boss for limiting, and a bottleneck factor of the narrow frame design is the minimum distance from the light guide plate limiting boss to the display area. The reason is that at a large viewing angle, the abnormal bright light refracted by the light guide plate limiting boss will pass through the gap between the backlight film and the middle frame, and abnormal picture unevenness (such as bright spots at the edge of the picture) will occur in the viewing angle picture observed by the human eye. With the increasing demand of users for full viewing angle picture effect, the problem of picture unevenness in the visible area of the light guide plate limiting boss position is increasingly testing the design requirements of the narrow frame.

[0052] Figure 1 A cross-sectional view of a backlight module in the related art is schematically shown. Figure 2 A cross-sectional view of a backlight module for light shielding improvement in the related art is schematically shown.

[0053] Reference Figure 1 The backlight module 100 includes a back plate 010, a middle frame 020, a light guide plate 030, and a limiting boss 032 on the light guide plate 030. Generally, the picture inspection viewing angle of the in-vehicle screen is a 45° angle perpendicular to the display direction. Since there is a design gap between the middle frame 020 and the optical film 040, the design specification of the gap value B is usually between 0.25-0.3 mm. The purpose of this design is to avoid the optical film 040 being pressed by the middle frame 020 under the condition of ensuring reliability, so as to ensure that the optical film 040 can freely expand and contract.

[0054] According to experience, the distance (A value) from the limiting boss 032 of the light guide plate to the display area AA area needs to be ensured to be ≥2.5 mm, so as to ensure that the bright spot MM area of the limiting boss 032 of the light guide plate cannot be seen within the 45° viewing angle range, thereby realizing the visual effect of picture uniformity. However, with the improvement of the picture quality requirement of users, the picture uniformity requirement of full viewing angle (backlight state viewing angle ≥80°) is proposed. At the same time, the limitation of the frame width of users leads to that the A value can only become smaller and smaller, which conflicts with the requirement of full viewing angle picture uniformity, and therefore other improvement schemes need to be considered.

[0055] For this problem, reference Figure 2 The improvement scheme of the related art is to attach a black light shielding tape 033 to the side of the limiting boss 032 of the light guide plate. Although the light shielding tape 033 can improve the bright spot problem at the edge of the picture viewing area close to the limiting boss 032 position, due to the influence of the light shielding tape 033, a dark shadow unevenness phenomenon will occur at the edge of the picture viewing area close to the limiting boss 032 position. Although users can accept slight dark shadows more than bright bands, this way still cannot meet the increasingly improved picture quality requirement.

[0056] In summary, in order to meet the requirement of full viewing angle picture uniformity and cope with the challenge of narrow frame design, the structure design needs to be further optimized to reduce light leakage and uneven shadow problems.

[0057] Figure 3 A plan view of a backlight module according to some example embodiments of the present disclosure is schematically shown. Figure 4 A cross-sectional view of a backlight module according to some example embodiments of the present disclosure is schematically shown; for example, Figure 4 may be a cross-sectional view taken along line CC' in Figure 3 .

[0058] Embodiments of the present disclosure provide a backlight module, with reference to Figure 3 , Figure 4 The backlight module 200 includes a back plate 10, a middle frame 20, a light guide plate 30, and an optical film 40. The back plate 10 includes a bottom plate 11 and a side plate 12. The side plate 12 is connected to an edge of the bottom plate 11 and forms a containing space 13 with the bottom plate 11. The middle frame 20 includes a frame body 21 and an extension 22. The frame body 21 is located on a side of the side plate 12 away from the containing space 13. The extension 22 is connected to the frame body 21 and located on a side of the side plate 12 away from the bottom plate 11, and extends above the containing space 13. The light guide plate 30 is located in the containing space 13. The light guide plate 30 includes a plate body 31 and a limiting boss 32. The limiting boss 32 is connected to an edge of the plate body 31 and protrudes from a surface of the plate body 31 away from the bottom plate 11. The optical film 40 is located on a side of the plate body 31 away from the bottom plate 11. The limiting boss 32 is configured to limit the optical film 40.

[0059] In embodiments of the present disclosure, the bottom plate 11 is a basic support structure of the backlight module 200, which can be made of metal or plastic material. Its main function is to provide stable support. The side plate 12 is arranged around the periphery of the bottom plate 11 and forms a containing space 13 with the bottom plate 11, which is used to accommodate the light guide plate 30 and other components. The side plate 12 can have a certain height to ensure sufficient space to accommodate the light guide plate 30 and other components.

[0060] The middle frame 20 is a support frame in the backlight module 200, which is located at the periphery of the backlight module 200. The extension 22 of the middle frame 20 abuts against the side plate 12 of the back plate 10, which is used to fix and protect the internal components. The middle frame 20 is used to support the liquid crystal display panel and limit the components such as the light guide plate 30 and the optical film 40 in the backlight module 200, to ensure that these components remain stable during assembly and use. At the same time, the middle frame 20 can block the edge part of the backlight module 200 to prevent light from leaking out from the side.

[0061] The light guide plate 30 mainly functions to uniformly scatter light emitted by a light source such as an LED to the entire panel to form a uniform surface light source, and to control the propagation direction of the light so that the light is mainly output to the display area AA of the liquid crystal display panel, thereby reducing light loss. The light guide plate can be made of a material with high light transmittance, for example, the material includes polymethyl methacrylate (PMMA), polycarbonate (PC), and the like. In one aspect, the limiting boss 32 of the light guide plate is used to fix other components, such as a light bar or an optical film. On the other hand, the limiting boss 32 can refract or reflect abnormal bright light, which passes through the gap between the optical film 40 and the middle frame 20 of the backlight module, and produces bright spots or uneven pictures on the visual angle picture observed by the human eye.

[0062] Based on this, in the embodiments of the present disclosure, by reducing the gap between the optical film 40 and the middle frame 20, the problem of bright spots or bright spots generated in the display picture can be solved. In an exemplary embodiment, the extension part 22 includes: a light shielding part 23 located on the side of the extension part 22 close to the bottom plate 11 and connected with the extension part 22, and located on the side of the limiting boss 32 away from the side plate 12, the light shielding part 23 fills at least part of the gap between the extension part 22 and the optical film 40; the first surface S1 on the side of the light shielding part 23 away from the frame body 21 and the second surface S2 on the side of the extension part 22 away from the frame body 21 are arranged in the first direction, and the first direction is the extension direction of the extension part away from the frame body.

[0063] In the embodiments of the present disclosure, the light shielding part 23 is arranged between the optical film 40 and the middle frame 20, which at least partially reduces the gap between the optical film 40 and the middle frame 20, similar to the picture effect of reducing the gap between the optical film 40 and the middle frame 20 by pressing the extension part 22 downward, thereby reducing the abnormal bright light passing through the gap. At the same time, the light L refracted or reflected by the limiting boss 32 is at least partially absorbed by the light shielding part 23, so that the light guide plate boss bright spot cannot be seen within an angle of 85°, thereby avoiding the problem of bright spots or uneven pictures generated in the display picture, and the picture uniformity is very good, and the picture quality is improved.

[0064] It should be noted that the light shielding part 23 can be made of black plastic, black foam or EVA, etc., which have good light shielding performance.

[0065] According to some exemplary embodiments, the orthographic projection of the light shielding part 23 on the bottom plate 11 at least partially surrounds the orthographic projection of the limiting boss 32 on the bottom plate 11, the orthographic projection of the light shielding part 23 on the bottom plate 11 does not overlap with the orthographic projection of the limiting boss 32 on the bottom plate 11; and the orthographic projection of the light shielding part 23 on the bottom plate 11 is located within the orthographic projection of the optical film 40 on the bottom plate.

[0066] Reference Figure 3The light shielding portion 23 is located close to the limiting boss 32, and the orthographic projection of the light shielding portion 23 on the bottom plate 11 at least partially surrounds the orthographic projection of the limiting boss 32 on the bottom plate 11. The light shielding portion 23 is arranged on the upper side or the lower side of the AA area, i.e., the data binding side and the opposite side of the data binding side. Referring to Figure 4 The light shielding portion 23 is located between the extension portion 22 and the optical film 40, and the orthographic projection of the light shielding portion 23 does not overlap the orthographic projection of the limiting boss 32 on the bottom plate. The two are spaced apart in the planar layout, which can ensure sufficient expansion space for the limiting boss 32.

[0067] Figure 5 A cross-sectional view of a backlight module according to some comparative embodiments of the present disclosure is schematically shown.

[0068] Referring to Figure 4 The light shielding portion 23 is located away from the second surface S2 of the extension portion 22. Referring to Figure 5 The light shielding portion 23 is located close to the second surface S2 of the extension portion 22, and the first surface S1 of the light shielding portion is coplanar with the second surface S2 away from the frame body side of the extension portion, i.e., the first surface S1 and the second surface S2 are not spaced apart in the first direction. If the light shielding portion 23 is arranged close to the second surface S2 of the extension portion 22, it is easy to cause the appearance of a black shadow NN or the generation of a pressure mark on the optical film under vibration, resulting in abnormal picture. When the light shielding portion 23 is located away from the second surface S2 of the extension portion 22, it is far away from the AA area and almost does not affect the light rays of the AA area, avoiding the problem of the appearance of a black shadow NN. Referring to Figure 4 The light shielding portion 23 is arranged close to the limiting boss 32 to maximize the absorption of the light rays L refracted or reflected by the limiting boss 32, while ensuring that the appearance of a black shadow phenomenon does not occur due to the proximity of the light shielding portion 23 to the AA area.

[0069] Figure 6 A cross-sectional view of a backlight module according to some example embodiments of the present disclosure is schematically shown; for example, Figure 6 may be a cross-sectional view taken along the line CC’ in Figure 3 .

[0070] According to some example embodiments, the first surface S1 of the light shielding portion 23 away from the frame body 21 side has a first distance D1 in the first direction X from the second surface S2 of the extension portion 22 away from the frame body 21 side, and the third surface S3 of the light shielding portion 23 close to the frame body 21 side has a second distance D2 in the first direction X from the fourth surface S4 of the limiting boss 32 away from the frame body 21 side. The first distance D1 is greater than the second distance D2.

[0071] By setting the first distance D1 greater than the second distance D2, the light shielding part 23 is closer to the fourth surface S4 of the limiting boss 32 and farther away from the second surface S2 of the extending part 22, so as to absorb the light at the edge of the light guide plate 30, while avoiding the generation of black shadows at the edge of the AA area. Exemplarily, the first direction X is the extending direction of the extending part 22 from the frame body 21 to the AA area, or in other words, the first direction X is the extending direction of the extending part 22 away from the frame body 21; the second direction Z is the light emitting direction of the backlight module; for example, the first direction X and the second direction Z are perpendicular to each other; the third direction Y is a direction perpendicular to both the first direction X and the second direction Z.

[0072] According to some exemplary embodiments, the fifth surface S5 of the light shielding part 23 close to the bottom plate 11 and the sixth surface S6 of the optical film 40 away from the bottom plate 11 have a third distance D3 in the second direction Z, and the third distance D3 ranges from 0.05 to 0.15 mm.

[0073] The optical film 40 controls the propagation, reflection, refraction and polarization of light, etc., so as to improve the display brightness, uniformity and color performance of the backlight module 200. The optical film 40 includes one or more of a prism film, a diffusion film and a brightness enhancement film. Among them, the prism film is used to converge the light after homogenization, so as to ensure that the emitted light has a certain range in the exit angle, avoiding the small included angle between the emitted light and the light emitting surface. The diffusion film is used to convert point light source or line light source into uniform area light source, which makes light diffuse through special optical structure (such as microbeads or microlenses), so as to realize the uniform distribution of light; the diffusion film is divided into upper diffusion film and lower diffusion film, the lower diffusion film has high shielding and high brightness, and the upper diffusion film has high transmittance and high brightness. The brightness enhancement film is used to re-reflect the light reflected in the liquid crystal display panel, so as to increase the light utilization rate and ensure the display brightness of the display panel. Exemplarily, the diffusion film, the prism film and the brightness enhancement film are stacked on the light guide plate 30 in sequence, but the structure of the backlight module is not limited thereto.

[0074] With reference to Figure 6 The optical film 40 can be made of high molecular materials which are prone to deformation under temperature change or external force. In order to cope with this situation, a gap is provided between the middle frame 20 and the optical film 40, which can provide a certain deformation space for the optical film 40, so as to avoid wrinkles or warping of the optical film 40 due to stress or temperature change. In addition, after the light shielding part 23 is provided, the third distance D3 is maintained between the optical film 40 and the light shielding part 23, that is, a certain expansion and contraction space is still left. At the same time, the width W of the light shielding part 23 is much smaller than the size of the optical film 40 along the first direction X, so the light shielding part 23 almost does not affect the expansion and contraction space of the optical film 40 under stress or temperature change.

[0075] According to some example embodiments, the light shielding part 23 has a rectangular cross section along the light emitting direction of the backlight module 200; and / or the thickness of the light shielding part 23 along the light emitting direction of the backlight module 200 is 0.15-0.25 mm.

[0076] The gap between the middle frame 20 and the optical film 40 is 0.25-0.3 mm, and the thickness H of the light shielding part 23 is less than the gap, and the thickness H is set to 0.15-0.25 mm, that is, the light shielding part 23 does not contact the optical film 40, but still has a certain gap with the optical film 40, avoiding light scattering or reflection caused by contact, and being conducive to improving the uniformity and brightness of the display. The light shielding part 23 has a rectangular cross section, which is relatively simple in design, easy to manufacture and process, and suitable for common backlight module structures.

[0077] Figure 7 The cross-sectional view of the backlight module middle frame and the light shielding part according to some example embodiments of the present disclosure is schematically shown. Figure 8 The cross-sectional view of the backlight module middle frame and the light shielding part according to some example embodiments of the present disclosure is schematically shown.

[0078] According to some example embodiments, the first surface S1 of the light shielding part 23 away from the frame body 21 is connected to the fifth surface S5 of the light shielding part 23 close to the bottom plate 11 and the third surface S3 of the light shielding part 23 close to the frame body 21, and the corner formed by the connection of the first surface S1 and the fifth surface S5 is a rounded corner; and / or the corner formed by the connection of the third surface S3 and the fifth surface S5 is a rounded corner.

[0079] Referring to Figure 7 , the corner in the cross section of the light shielding part 23 is set to a rounded corner, which is conducive to reducing the scattering and reflection of light at the edge of the light shielding part 23, thereby improving the optical performance of the backlight module. This design can reduce the generation of stray light and avoid uneven distribution of light caused by sharp corners.

[0080] According to some example embodiments, the fifth surface S5 of the light shielding part 23 close to the bottom plate 11 is a bevel relative to the sixth surface S6 of the optical film 40 away from the bottom plate 11, and the thickness H of the light shielding part 23 along the light emitting direction of the backlight module 200 gradually decreases in the first direction X away from the frame body 21 of the extension part 22.

[0081] Referring to Figure 8 , the bevel transition is provided in the cross section of the light shielding part 23, which is conducive to reducing the scattering and reflection of light at the edge of the light shielding part 23. This design helps to reduce the generation of stray light and avoid uneven distribution of bright spots or dark shadows caused by edge reflection, thereby improving the optical uniformity of the backlight module. The cross-sectional shape of the light shielding part 23 can be designed according to actual needs, and the present disclosure does not limit it.

[0082] In embodiments of the present disclosure, the material selection of the middle frame 20, depending on its functional requirements and cost considerations, can include metal materials and plastics. Among them, metal materials such as aluminum alloy or stainless steel have high strength and good stability, and are commonly used in high-end or high-demand backlight modules; plastics such as polycarbonate (PC) and the like have relatively light weight and low cost, and are suitable for mid- and low-end products.

[0083] According to some exemplary embodiments, referring back to Figure 6 , the extension 22 includes a groove 24 located on the side of the extension 22 close to the bottom plate 11, the groove 24 is located on the side of the light shielding part 23 close to the frame body 21; at least part of the limiting boss 32 is located in the groove 24.

[0084] Placing at least part of the limiting boss 32 in the groove 24 can effectively limit the movement or expansion of the light guide plate 30 in the first direction X, thereby improving the structural stability of the entire backlight module, while also helping to reduce light leakage and improve display effects.

[0085] According to some exemplary embodiments, the seventh surface S7 of the groove 24 away from the frame body 21 side is connected with the third surface S3 of the light shielding part close to the frame body side.

[0086] In order to make the light shielding part 23 as close to the limiting boss 32 as possible, the third surface S3 of the light shielding part 23 can be arranged to be coplanar with the surface S5 of the groove 24 to maximize the absorption of light rays refracted or reflected by the limiting boss 32. When the third surface S3 of the light shielding part 23 is a plane, the seventh surface S7 connected with the third surface S3 means that they are coplanar; when the third surface S3 of the light shielding part 23 is provided with a rounded corner, the seventh surface S7 is connected with the upper half of the third surface S3 and is coplanar.

[0087] Figure 9 The cross-sectional view of the backlight module according to some exemplary embodiments of the present disclosure is schematically shown; for example, Figure 9 may be a cross-sectional view taken along the line CC' in Figure 3 .

[0088] According to some exemplary embodiments, the middle frame 20 is a plastic frame, and the light shielding part 23 is integrally formed with the middle frame 20. Integrally forming the light shielding part 23 with the middle frame 20 is conducive to ensuring the stability of the light shielding part 23 to avoid disengagement under external force impact.

[0089] According to some exemplary embodiments, the third surface S3 of the light shielding part 23 close to the frame body 21 side is at least partially coplanar with the fourth surface S4 of the limiting boss 32 away from the frame body 21 side, and the third surface S3 and the fourth surface S4 are not in contact.

[0090] Referring toFigure 4 、 Figure 6 The extension 22 is provided with a groove 24 on the side close to the bottom plate 11, and the light shielding part 23 is arranged immediately adjacent to the groove 24. Referring to Figure 9 Without the limitation of the groove, the light shielding part 23 can be arranged immediately adjacent to the fourth surface S4 of the limiting boss 32. The third surface S3 of the light shielding part 23 can also be located above the fourth surface S4 of the limiting boss 32, and the third surface S3 is not in contact with the fourth surface S4. The light shielding part 23 is not arranged above the limiting boss 32 and is not in contact with the fourth surface S4, in order to ensure the expansion and contraction space of the limiting boss 32.

[0091] Figure 10 schematically shows a cross-sectional view of a backlight module according to some other example embodiments of the present disclosure; for example, Figure 10 may be a cross-sectional view taken along the line CC’ in Figure 3 . Figure 11 schematically shows a cross-sectional view of a backlight module according to some other comparative embodiments of the present disclosure.

[0092] According to some example embodiments, the middle frame 20 is a metal frame, and the middle frame 20 comprises: a light shielding tape 24 located on the side of the extension 22 close to the bottom plate 11, and the light shielding part 23 is attached to the light shielding tape 24; the orthographic projection of the light shielding part 23 on the bottom plate 11 is located within the orthographic projection of the light shielding tape 24 on the bottom plate 11.

[0093] In the backlight module, when the metal frame is used as the middle frame 20, the surface of the metal frame may be affected by reflection, which affects the display effect. In order to prevent this reflection phenomenon, the light shielding tape 24 can be attached to the side of the metal frame close to the bottom plate 11. The light shielding tape 24 can effectively absorb and shield light, reduce the reflection phenomenon on the surface of the metal frame, and thus avoid the interference of reflection on the display effect. The light shielding part 23 can be directly attached to the light shielding tape 24, which is easy to process, and can be cut and installed according to the specific shape and size of the light shielding tape 24, and has high flexibility.

[0094] According to some example embodiments, the eighth surface S8 of the light shielding tape 24 on the side close to the frame body 21 has a fourth distance D4 in the first direction X between the fourth surface S4 on the side away from the frame body 21 of the limiting boss 32; the eighth surface S8 of the light shielding tape 24 and the third surface S3 of the light shielding part 23 on the side close to the frame body 21 are at least partially coplanar.

[0095] Referring to Figure 10The eighth surface S8 of the light shielding tape 24 is spaced apart from the limiting boss 32 to avoid affecting the expansion space of the limiting boss 32. The ninth surface S9 of the light shielding tape 24 away from the frame body 21 can be coplanar with the second surface S2 of the extension 22 or can be spaced apart from the second surface S2 of the extension 22. In the actual process, in order to avoid the light shielding tape 24 from casting a shadow beyond the second surface S2 of the extension 22, the ninth surface S9 of the light shielding tape 24 is inwardly spaced apart from the second surface S2 of the extension 22. When the light shielding portion 23 is attached to the light shielding tape 24, the light shielding portion 23 is close to the limiting boss 32 to avoid display unevenness such as a shadow. The third surface S3 of the light shielding portion 23 is coplanar with the eighth surface S8 of the light shielding tape 24, which is conducive to the light shielding portion 23 being close to the limiting boss 32 to maximize the absorption of light L refracted or reflected by the limiting boss 32.

[0096] With reference to Figure 10- Figure 11 , taking a 15.6-inch display module as an example, when only the light shielding tape 24 is provided, the backlight module 500 can see the bright spot of the limiting boss 32 at about 60°-90°, as shown in Figure 11 ; when the light shielding tape 24 and the light shielding portion 23 are provided at the same time, the backlight module 400 can see an unobvious bright spot at about 80°-90°, and the display module has excellent picture uniformity at 0-90° viewing angle, as shown in Figure 10 . It can be seen that, by providing the light shielding portion 23 below the light shielding tape 24 of the metal frame, the problem of abnormal bright light caused by the limiting boss 32 is solved, the risk of observing a bright spot or uneven picture by the human eye at a large viewing angle is reduced, and the picture quality is improved.

[0097] According to some exemplary embodiments, the backlight module 200 comprises: a light source 14 located on at least one side of the side plate 12 close to the light guide plate 30, and the light source 14 is arranged opposite to the light-incident surface S6 of the light guide plate 30.

[0098] In the embodiments of the present disclosure, referring back to Figure 6 , the backlight module 200 is a side-in type, and the side-in type backlight module can achieve a thinner body thickness and is suitable for devices with high requirements for thinness. The light emitted by the light source 14 is incident through the light-incident surface S6 of the light guide plate 30, and a reflective film 50 is further arranged on the side of the light guide plate 30 close to the bottom plate 11. The light incident into the light guide plate 30 is reflected by the reflective film 50 and scattered by the light guide plate 30, and then is emitted through the light-emitting surface S7 of the light guide plate, so as to achieve the purpose of providing a light source for a liquid crystal display panel to display an image.

[0099] Exemplarily, the light source 14 is an LED light bar. The LED backlight module has low power consumption, can significantly reduce the overall energy consumption of the device, and has good color uniformity, thereby providing high-quality display effect.

[0100] The present disclosure also relates to a display device, in particular a vehicle-mounted display device, comprising the above-mentioned backlight module. The vehicle-mounted display device of the present disclosure is exemplarily a high-end vehicle-mounted instrument, a vehicle-mounted central control display, a vehicle-mounted driving recorder, a vehicle-mounted DVD navigation, a vehicle-mounted integrated display screen of the driver's cab, a vehicle-mounted streaming media rearview mirror, or a car seat headrest display, but is not limited thereto.

[0101] Figure 12 A structural schematic diagram of a display device 1000 provided for an embodiment of the present disclosure is shown in FIG. 10. The display device 1000 comprises a backlight module 200 or 400 and a liquid crystal display panel 70 disposed on the backlight module 200 or 400. The liquid crystal display panel 70 is connected to the backlight module 200 or 400 by a foam tape 60. The foam tape 60 is a double-sided tape, which can be made of polyethylene or polypropylene, and has good elasticity and adhesion. The foam tape 60 firmly fixes the liquid crystal display panel 70 on the backlight module 200 or 400, ensuring that the two will not loosen during use. Meanwhile, the foam tape 60 has a certain elasticity, which can absorb external impact and protect the liquid crystal display panel 70 and the backlight module 200 or 400.

[0102] It should be understood that the display device 1000 according to some exemplary embodiments of the present disclosure has all the features and advantages of the display substrate 200 or 400 described above, which can be referred to the description of the display substrate 200 or 400 above, and will not be repeated here.

[0103] As used herein, the terms "substantially," "about," "approximately," and other similar terms are used as terms of approximation and not as terms of degree, and they are intended to account for the inherent deviations in measured or calculated values that would be recognized by those of ordinary skill in the art. In view of the process fluctuations, measurement problems, and errors associated with the measurement of a particular quantity (i.e., limitations of the measurement system), etc., "about" or "approximately," as used herein, includes the stated value and means a value that is within an acceptable range of deviation for the particular value as determined by one of ordinary skill in the art. For example, "about" can mean within one or more standard deviations, or within ±10% or ±5% of the stated value.

[0104] While some embodiments in accordance with the general inventive concept of the present disclosure have been illustrated and described, it is understood that various changes in form and details can be made therein without departing from the principles and spirit of the general inventive concept of the present disclosure, the scope of which is defined with the following claims and their equivalents.

Claims

1. A backlight module, comprising: a back plate comprising a bottom plate and a side plate, the side plate being connected to an edge of the bottom plate and forming a containing space with the bottom plate; a middle frame comprising a frame body and an extension, the frame body being located on a side of the side plate away from the containing space, and the extension being connected to the frame body, located on a side of the side plate away from the bottom plate, and extending into the containing space; a light guide plate located in the containing space, the light guide plate comprising a plate body and a limiting boss, the limiting boss being connected to an edge of the plate body and protruding from a surface of the plate body away from the bottom plate; and an optical film located on a side of the plate body away from the bottom plate, the limiting boss being configured to limit the optical film, wherein the extension comprises: a light shielding portion located on a side of the extension close to the bottom plate and connected to the extension, and located on a side of the limiting boss away from the side plate, the light shielding portion filling at least part of a gap between the extension and the optical film; a first surface of the light shielding portion away from the frame body and a second surface of the extension away from the frame body are spaced apart in a first direction, the first direction being an extension direction of the extension away from the frame body. A normal projection of the light shielding portion on the bottom plate at least partially surrounds a normal projection of the limiting boss on the bottom plate, and the normal projection of the light shielding portion on the bottom plate does not overlap with the normal projection of the limiting boss on the bottom plate.

2. The backlight module of claim 1, wherein, The normal projection of the light shielding portion on the bottom plate is located within a normal projection of the optical film on the bottom plate. The first surface of the light shielding portion away from the frame body and the second surface of the extension away from the frame body have a first distance in the first direction, and a third surface of the light shielding portion close to the frame body and a fourth surface of the limiting boss away from the frame body have a second distance in the first direction, the first distance being greater than the second distance.

3. The backlight module of claim 1, wherein, A fifth surface of the light shielding portion close to the bottom plate and a sixth surface of the optical film away from the bottom plate have a third distance in a second direction, the third distance being in a range of 0.05-0.15 mm.

4. The backlight module of claim 1, wherein, A cross section of the light shielding portion in a light-out direction of the backlight module is rectangular; and / or 5. The backlight module according to any one of claims 1-4, wherein, A thickness of the light shielding portion in the light-out direction of the backlight module is 0.15-0.25 mm. The first surface of the light shielding portion away from the frame body is connected to the fifth surface of the light shielding portion close to the bottom plate and the third surface of the light shielding portion close to the frame body, and a corner formed by the first surface and the fifth surface is rounded; and / or a corner formed by the third surface and the fifth surface is rounded.

6. The backlight module of any of claims 1-4, wherein, The fifth surface of the light shielding portion close to the bottom plate is a bevel relative to the sixth surface of the optical film away from the bottom plate; 7. The backlight module of any of claims 1-4, wherein, In the first direction of the extension away from the frame body, the thickness of the light shielding portion in the light-out direction of the backlight module gradually decreases. ​ 8. The backlight module of claim 1, wherein, The middle frame is a glue frame, and the light shielding part and the middle frame are in an integral molding structure.

9. The backlight module of claim 8, wherein, The third surface of the light shielding part on the side close to the frame body is at least partially coplanar with the fourth surface of the limiting boss on the side away from the frame body, and the third surface and the fourth surface are not in contact.

10. The backlight module of claim 8, wherein, The extension part comprises: A groove is located on the side of the extension part close to the bottom plate, the groove is located on the side of the light shielding part close to the frame body, and at least part of the limiting boss is located in the groove.

11. The backlight module of claim 10, wherein, The seventh surface of the groove on the side away from the frame body is connected with the third surface of the light shielding part on the side close to the frame body.

12. The backlight module of claim 1, wherein, The middle frame is a metal frame, and the middle frame comprises: A light shielding adhesive tape is located on the side of the extension part close to the bottom plate, and the light shielding part is attached to the light shielding adhesive tape; the orthographic projection of the light shielding part on the bottom plate is located in the orthographic projection of the light shielding adhesive tape on the bottom plate.

13. The backlight module of claim 12, wherein, The eighth surface of the light shielding adhesive tape on the side close to the frame body and the fourth surface of the limiting boss on the side away from the frame body have a fourth distance in the first direction; The eighth surface of the light shielding adhesive tape and the third surface of the light shielding part on the side close to the frame body are at least partially coplanar.

14. A display device comprising: The display device comprises the backlight module according to any one of claims 1-13.

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