Backlight module and liquid crystal display device

Abstract

The present invention discloses a backlight module and a liquid crystal display device, wherein the backlight module includes a backplane structure, a light guide plate, a middle frame, a baffle structure and a light source, the edge of the backplane structure is bent to form a side wall; the light guide plate is arranged in the middle position of the backplane structure; the middle frame is arranged on the side wall, and the middle frame extends to the upper part of the light emitting surface of the light guide plate; the baffle structure is arranged on the middle frame, and is located between the middle frame and the light guide plate; the backplane structure, the middle frame, the light guide plate and the baffle structure form a closed inner cavity; the light source is arranged in the closed inner cavity, and is used to emit light to the light guide plate. The backlight module disclosed in the present application forms a closed inner cavity, so that the heat generated by the light source when working will not be conducted to the light emitting surface of the light guide plate, thereby protecting the quantum dot membrane arranged above the light emitting surface of the light guide plate, so that the backlight module can emit white light normally.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor display technology, and in particular to a backlight module and a liquid crystal display device. Background Art

[0002] At present, with the continuous development of liquid crystal display technology, the application field of liquid crystal display, especially color liquid crystal display, is also expanding. Driven by the market of liquid crystal display (LCD), the backlight industry is booming. Common LCD is a non-luminous display device that requires the help of a backlight module to achieve the display function, so the performance of the backlight module will directly affect the image quality of the LCD. At present, there are mainly two types of backlight sources: edge-lit and direct-lit. The edge-lit backlight module is mainly composed of a backplane, a light source, a light guide plate, an optical film, a middle frame, a front frame and other components.

[0003] However, in the existing backlight module, the light source, light guide plate, optical film and other structures are concentrated in a closed space surrounded by the back plate, middle frame, front frame, liquid crystal glass and other structures. During operation, the light source emits light and generates heat at the same time, and the optical film has insufficient heat resistance and is easily failed due to the increase in surface temperature. It is impossible to effectively convert the color of the light emitted by the light source, which will eventually lead to the defect that the backlight module cannot emit white light normally.

[0004] Therefore, the prior art still needs to be improved and developed. Summary of the invention

[0005] In view of the above-mentioned deficiencies in the prior art, an object of the present invention is to provide a backlight module and a liquid crystal display device, aiming to solve the problem that the heat generated by the light source causes the optical film to fail and affects the normal white light emission of the backlight module.

[0006] The technical solution of the present invention is as follows:

[0007] A backlight module, comprising a backplane structure, a light guide plate, a middle frame, a baffle structure and a light source, wherein the edge of the backplane structure is bent to form a side wall; the light guide plate is arranged in the middle position of the backplane structure; the middle frame is arranged on the side wall, and the middle frame extends to above the light emitting surface of the light guide plate; the baffle structure is arranged on the middle frame, and is located between the middle frame and the light guide plate; the backplane structure, the middle frame, the light guide plate and the baffle structure form a closed inner cavity; the light source is arranged in the closed inner cavity, and is used to emit light to the light guide plate.

[0008] The backlight module, wherein the blocking structure includes an adhesive layer, a light absorbing layer and a heat insulating layer, one side of the adhesive layer is bonded to the surface of the middle frame, and the other side is connected to the light absorbing layer; the heat insulating layer is arranged on the side of the light absorbing layer away from the adhesive layer.

[0009] The backlight module, wherein the back panel structure includes a back frame and a heat dissipation strip fixed on the back frame, one side of the heat dissipation strip is bent to form the side wall, and the other side is stacked with the light guide plate, the baffle structure and the middle frame in sequence; the heat dissipation strip, the light guide plate, the baffle structure and the middle frame form the closed inner cavity, and the light source is fixed on the heat dissipation strip at a position opposite to the side of the light guide plate.

[0010] In the backlight module, surfaces of the back frame and the heat dissipation strips are coated with a heat dissipation coating.

[0011] In the backlight module, the heat dissipation coating is a nano heat dissipation coating layer coated by nano coating technology.

[0012] In the backlight module, the light source comprises a light emitting element and a substrate, the light emitting element is fixed on the substrate; a groove is provided on the heat dissipation bar, and the substrate extends and is inserted into the groove.

[0013] In the backlight module, a heat-conducting adhesive layer is provided in the groove, and the substrate is bonded to the heat dissipation strip via the heat-conducting adhesive layer.

[0014] The backlight module, wherein the backlight module also includes a reflective sheet, which is arranged on the back panel and is used to reflect the light emitted by the light source to the light guide plate; the edge of the reflective sheet is also coated with a color complementary coating, and the color of the color complementary coating is complementary to the color of the light emitted by the light source.

[0015] The backlight module, wherein the middle frame is a plastic middle frame.

[0016] The present application also discloses a liquid crystal display device, which includes any of the backlight modules described above.

[0017] Compared with the prior art, the embodiments of the present invention have the following advantages:

[0018] The backlight module disclosed in the present application is provided with a blocking structure between the middle frame and the light guide plate, thereby forming a closed inner cavity, and the light source is arranged in the closed inner cavity to be separated from other components; when the backlight module is working, the heat generated by the light source diffuses in the closed inner cavity, but is not directly transmitted to the surface of the optical film, which is beneficial to reducing the temperature of the surface of the optical film, ensuring that the operating temperature of the optical film does not exceed its safe temperature during operation, reducing the occurrence of optical film failure, improving the use efficiency of the optical film, extending the overall service life of the backlight module, and allowing each component of the backlight module to work normally, thereby emitting white light normally. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 is a chromaticity diagram of the display device in the present invention;

[0021] Figure 2 It is a schematic diagram of the structure of the quantum dot film in the present invention;

[0022] Figure 3 It is a structural explosion diagram of the backlight module in the present invention;

[0023] Figure 4 is a cross-sectional view of the backlight module of the present invention;

[0024] Figure 5 It is a structural schematic diagram of the blocking structure in the present invention;

[0025] Figure 6 is a cross-sectional view of the backlight module of the present invention;

[0026] Figure 7 It is a schematic diagram of the structure of the reflector in the present invention.

[0027] Among them, 10, back panel structure; 11, side wall; 12, back frame; 13, heat dissipation strip; 131, groove; 20, light guide plate; 30, middle frame; 40, baffle structure; 41, adhesive layer; 42, light absorption layer; 43, heat insulation layer; 44, centrifugal film layer; 50, closed inner cavity; 60, light source; 61, light-emitting element; 62, substrate; 70, optical film; 80, reflective sheet; 90, liquid crystal glass. DETAILED DESCRIPTION

[0028] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] In the prior art, with the development and widespread application of liquid crystal display devices, consumers have higher requirements for the color reproduction of liquid crystal display devices, that is, the color gamut value requirements are getting higher and higher. The backlight module is an important component of the liquid crystal display device. The high color gamut display of the liquid crystal display device is usually achieved by improving the color gamut of the light source of the backlight module. Figure 1 As shown in the figure, all the colors in nature are contained in the points in the horseshoe area. Each point in the figure is symbolically represented as the corresponding color. It is said to be "symbolic" because there are many colors in nature that cannot be accurately reproduced using the three primary colors principle. In addition, Figure 1 The area surrounded by a triangle is the color gamut. The three vertices of the triangle are the color coordinates of the three primary colors of the display device's pixels, and the colors that can be configured from these three primary colors are contained in the area inside the triangle. Obviously, the color coordinates of the three primary colors of each display device are different, the position of the triangle is different, and the color gamut will be different; the larger the area of ​​the triangle, the larger the color gamut.

[0030] The emergence of quantum dot technology has improved the colors that can be displayed by the backlight module. Specifically, at this stage, the liquid crystal display based on quantum dot technology is an optical film made by adding a layer of quantum dots to the traditional backlight module. Quantum dots are a nano-scale material that can emit light. Under the excitation of short waves (blue light or purple light), quantum dot particles of different diameters can emit different pure colors of light with a smaller half-wave width, which can achieve better color mixing to achieve a high color gamut display of the backlight module. The use of quantum dot materials can obtain red and green light with higher saturation, and can achieve a true high color gamut display of more than 100% of the NTSC CIE1931 standard.

[0031] like Figure 2 As shown in the figure, a quantum dot film is made by dispersing quantum dots with diameters of 3 nanometers and 7 nanometers into a film and sandwiching it with two layers of protective films. When the backlight source uses a blue light-emitting diode, the blue light passing through the quantum dot film is converted into green light by the 3-nanometer quantum dots, and converted into red light by the 7-nanometer quantum dots. Finally, the blue light, green light and red light are mixed on the light-emitting surface of the quantum dot film to form white light.

[0032] Quantum dot film has advantages as well as disadvantages. In actual use, quantum dot film is very sensitive, and its molecular bonds are easily affected by water, oxygen and temperature in the environment, making it easy to fail. In the actual use environment of quantum dot film, it is recommended that the system temperature does not exceed 70 degrees Celsius. If the surface temperature is too high, the quantum dot film may fail. The higher the temperature, the faster the failure. In traditional backlight modules, the distance between the light source and the optical film is close, and the heat generated when the light source is working will quickly be transferred to the surface of the optical film such as the quantum dot film, diffusion film, protective film, etc., affecting the use of the optical film, which may cause the backlight module to leak the light source color and fail to display white light normally, thereby seriously affecting the picture quality of the liquid crystal display device and reducing user satisfaction.

[0033] See also Figure 3 and Figure 4 In one embodiment of the present invention application, a backlight module is disclosed, which includes a backplane structure 10, a light guide plate 20, a middle frame 30, a baffle structure 40 and a light source 60, wherein the edge of the backplane structure 10 is bent to form a side wall 11; the light guide plate 20 is arranged at the middle position of the backplane structure 10; the middle frame 30 is arranged on the side wall 11, and the middle frame 30 extends to above the light emitting surface of the light guide plate 20; the baffle structure 40 is arranged on the middle frame 30, and is located between the middle frame 30 and the light guide plate 20; the backplane structure 10, the middle frame 30, the light guide plate 20 and the baffle structure 40 form a closed inner cavity 50; the light source 60 is arranged in the closed inner cavity 50, and is used to emit light to the light guide plate 20.

[0034] The backlight module disclosed in this embodiment is provided with a blocking structure 40 between the middle frame 30 and the light guide plate 20, so as to form a closed inner cavity 50, and the light source 60 is provided in the closed inner cavity 50, separated from other components; when the backlight module is working, components such as the optical film 70 and the liquid crystal glass 90 are provided on the middle frame 30, and are located outside the closed inner cavity 50. Only one side of the optical film 70 close to the light source 60 can be provided on the upper side of the middle frame 30, and is located outside the closed inner cavity 50, or the optical film 70 can be completely placed on the middle frame 30. Upper side; the heat generated by the light source 60 when it emits light diffuses in the closed inner cavity 50, but will not be directly transmitted to the surface of the optical film 70, reducing the impact of the heat generated by the light source 60 on the optical film 70, which is beneficial to reducing the temperature of the surface of the optical film 70, ensuring that the operating temperature of the optical film 70 does not exceed its safe temperature during operation, reducing the occurrence of failure of the optical film 70, improving the use efficiency of the optical film 70, extending the overall service life of the backlight module, and allowing all components of the backlight module to work normally, thereby emitting white light normally.

[0035] See also Figure 3As an implementation of this embodiment, it is disclosed that the back panel structure 10 includes a back frame 12 and a heat dissipation bar 13 fixed on the back frame 12, one side of the heat dissipation bar 13 is bent to form the side wall 11, and the other side is stacked in sequence with the light guide plate 20, the blocking structure 40 and the middle frame 30; the heat dissipation bar 13, the light guide plate 20, the blocking structure 40 and the middle frame 30 form the closed inner cavity 50, and the light source 60 is fixed on the heat dissipation bar 13 at a position opposite to the side of the light guide plate 20. Firstly, the heat dissipation strip 13 is provided as a partial structure for forming the closed inner cavity 50, which is beneficial to accelerate the guidance of the heat in the closed inner cavity 50 to be conducted to the heat dissipation strip 13, and then conducted to the air environment through the heat dissipation strip 13, so as to achieve heat dissipation, accelerate the heat dissipation speed of the closed inner cavity 50, cool down in time, and prevent high temperature from damaging the components of the backlight module; moreover, when the heat dissipation speed on the heat dissipation strip 13 on the backlight side is fast and the heat of the closed inner cavity 50 is lost quickly, the heat of the components such as the middle frame 30, the optical film 70, and the liquid crystal glass 90 guided to the light emitting side will be reduced, the temperature of the environment around the optical film 70 will be reduced, and the occurrence of high-temperature failure of the optical film 70 will be reduced, thereby reducing the temperature in the entire backlight module, so that the components in the backlight module can all work normally.

[0036] Secondly, the light source 60 is fixed on the side wall 11 formed by the bending of the heat dissipation strip 13 and directly contacts the heat dissipation strip 13. The heat generated by the light source 60 can be directly transferred to the heat dissipation strip 13 without passing through the air medium in the closed inner cavity 50, which further accelerates the heat conduction and improves the heat dissipation efficiency.

[0037] Specifically, as another implementation of this embodiment, the heat dissipation bar 13 is disclosed to be detachably matched with the back frame 12. The heat dissipation bar 13 is connected to the back frame 12 by means of snap connection, plug connection, screw connection, etc., which is convenient for disassembly, replacement, and maintenance. For example, in this implementation, the heat dissipation bar 13 is attached to the back frame 12 by an external lock, and can be disassembled from the outside of the back frame 12. When the light output of the backlight module is abnormal, the heat dissipation bar 13 can be quickly removed for inspection without removing the entire back panel structure 10.

[0038] Specifically, as another implementation of this embodiment, the surfaces of the back frame 12 and the heat dissipation strip 13 are coated with a heat dissipation coating (not shown in the attached drawings). The heat dissipation coating can be a coating formed by spraying a high thermal conductivity coating. For example, a nano heat dissipation coating layer coated with nano coating technology can be used as a high thermal conductivity coating. The nano heat dissipation coating can automatically radiate into space with a far infrared wavelength of 8 to 14 microns to take away the heat of the object and reduce the surface and internal temperature of the object. Its main components are: acrylic resin and epoxy resin account for 2% to 10%; aluminum nitride, silicon carbide, diluent and curing agent account for 70% to 98%. Nano coating technology converts heat into infrared rays and emits them in the form of thermal radiation, which can improve the heat dissipation efficiency, reduce the temperature rise of the system, and have a significant effect of heat dissipation and cooling, thereby further enhancing the heat dissipation effect of the heat dissipation strip 13 and the back frame 12, reducing the temperature of the overall structure of the backlight module, and maintaining the normal working state of the backlight module.

[0039] See also Figure 4 As another implementation of this embodiment, the light source 60 is disclosed to include a light-emitting element 61 and a substrate 62, wherein the light-emitting element 61 is fixed on the substrate 62; a groove 131 is provided on the heat dissipation bar 13, and the substrate 62 extends and is inserted into the groove 131. The light source 60 disclosed in this embodiment can be a light-emitting diode (LED) chip, an organic light-emitting diode (OLED) chip, a Mini LED chip, a Micro LED chip, and the like. Taking the LED chip as an example, the LED lamp bead is installed on the substrate 62 as the light-emitting element 61. When the light is emitted, the heat is not only conducted to the air, but also to the substrate 62. The substrate 62 is inserted into the groove 131 and contacts the side wall 11 and the bottom wall of the groove 131, that is, the contact surface area between the substrate 62 and the heat dissipation bar 13 is increased, so that the heat on the substrate 62 can be conducted faster, and the heat dissipation efficiency on the substrate 62 is improved.

[0040] See also Figure 4 The groove 131 is set at the corner of the heat dissipation bar 13, and the substrate 62 is inserted into the groove 131. The groove 131 also has the function of fixing the substrate 62, so that the light source 60 can be more stably installed on the heat dissipation bar 13, avoiding the heat dissipation bar 13 and the light source 60 from being separated during use, and maintaining good heat dissipation efficiency.

[0041] Specifically, as another implementation of this embodiment, a heat-conducting adhesive layer (not shown in the drawings) is provided in the groove 131, and the substrate 62 is bonded to the heat dissipation bar 13 through the heat-conducting adhesive layer. By providing a heat-conducting adhesive layer in the groove 131, there is no air gap between the heat dissipation bar 13 and the substrate 62, and both are filled with the heat-conducting adhesive layer, thereby further accelerating the heat conduction efficiency. The heat-conducting adhesive layer in this embodiment is connected by a heat-conducting adhesive with a high conductivity coefficient, the main component of which is acrylic resin, and the carrier is a PET film, which is white in color. An adhesive layer with a thickness of about 250 microns can be provided on the PET film to facilitate fixing the heat-conducting adhesive layer in the groove 131.

[0042] See also Figure 5 As another implementation of this embodiment, it is disclosed that the blocking structure 40 includes an adhesive layer 41, a light absorbing layer 42 and a heat insulating layer 43, one side of the adhesive layer 41 is bonded to the surface of the middle frame 30, and the other side is connected to the light absorbing layer 42; in this embodiment, the adhesive layer 41 can be an epoxy resin adhesive layer, a glass adhesive layer, a pressure-sensitive adhesive layer, etc.; bonding is a connection method with good sealing performance, and the contact interface of the blocking structure 40 and the middle frame 30 is completely fitted through the adhesive layer 41, so that the connection strength is high, it is not easy to fall off or shift, and gaps are avoided, thereby improving the effect of blocking heat conduction.

[0043] In addition, in another embodiment of the present embodiment, the color of the light absorbing layer 42 is black, which is used to absorb light. The light absorbing layer 42 is made of polyethylene or foamed polyurethane through foaming technology, and black has a good light absorption effect, which is conducive to improving the light absorption effect of the light absorbing layer 42; according to the preset light path of the backlight module, the side-entry light source 60 is arranged on the side wall 11, located on the side of the light guide plate 20, and the emitted light passes through the light guide plate 20 and then emits to the optical film 70; however, in the actual working process, the light emitted by the light source 60 is scattered, that is, when emitting light, the obliquely emitted light will also be emitted to the middle frame 30 and the blocking structure 40 and other parts. The traditional middle frame 30 is opaque. In this embodiment, the light absorbing layer 42 is arranged to absorb the light passing through the heat insulation layer 43, and it is also to block the light, so that the blocking structure 40 also becomes an opaque structure, to avoid light leakage from the baffle structure, thereby reducing the messy light from being emitted to the optical film 70, and preventing the light output effect of the backlight module from being affected.

[0044] In addition, another implementation of the present embodiment further discloses that the heat insulation layer 43 is arranged on the side of the light absorbing layer 42 away from the adhesive layer 41, that is, the heat insulation layer 43 is arranged on the side of the baffle structure facing the light source 60, so that the heat is blocked in the heat insulation layer 43, reducing the impact on the light absorbing layer 42 and the adhesive layer 41. Especially for some organic adhesives, high temperature will reduce the adhesion ability of the colloid and even age rapidly, shortening the effective service life, so the heat insulation layer 43 is arranged at a position closer to the light source 60, which can prevent the adhesive layer 41 from failing due to high temperature.

[0045] Specifically, the thermal insulation layer 43 disclosed in the present embodiment is a composite layer of silica and glass fiber. Silica has good thermal insulation properties, especially silica aerogel, which is currently recognized as one of the solid materials with the lowest thermal conductivity due to its special nanopore level and skeleton particles; glass fiber is an inorganic non-metallic material with excellent performance and a wide variety of types. Its advantages are good insulation, strong heat resistance, good corrosion resistance, and high mechanical strength; a composite layer of silica and glass fiber with excellent thermal insulation performance can be made with silica and glass fiber as the main components, with a thermal conductivity of about 0.02W / (m*K), and a general thickness controlled at 0.6-1.5 mm. Specifically, the components of the composite layer of silica and glass fiber disclosed in the present embodiment are shown in Table 1 below:

[0046] Chemical name of components Content percentage (%) Amorphous Silica 35-55 Glass fiber yarn 40-60 Titanium Dioxide 3-10 Aluminum hydroxide 0-10

[0047] Table 1

[0048] See also Figure 5 The blocking structure 40 disclosed in this embodiment can be manufactured separately. After production, a centrifugal film layer 44 can be covered on the surface of the adhesive layer 41 to facilitate transportation and cutting. When manufacturing the backlight module, the centrifugal film layer 44 can be torn off and the adhesive layer 41 can be attached to the middle frame 30.

[0049] See also Figure 4 and Figure 6As another implementation of this embodiment, the backlight module is disclosed to further include a reflective sheet 80, which is disposed on the back plate and is used to reflect the light emitted by the light source 60 to the light guide plate 20; wherein the edge of the reflective sheet 80 is also coated with a color complementary coating (not shown in the drawings), and the color of the color complementary coating is complementary to the color of the light emitted by the light source 60. The light that does not enter the light guide plate 20 and the light that overflows from the side of the light guide plate 20 may leak from the side of the optical film 70, that is, if it does not pass through the quantum dot film, the emitted light is not white, but the color of the light source 60, and the edge of the light-emitting surface of the backlight module is prone to visual color deviation, affecting the viewing experience. The quantum dot film is disposed above the light guide plate 20, so the color complementary coating is disposed on the four sides of the reflective sheet 80, and corresponds to the color type of the light source 60, for example, the blue light source 60 corresponds to the yellow coating, and the purple light source 60 corresponds to the green coating, so as to neutralize the color of the light source 60, so that the light emitted from the edge of the backlight module can be turned into white, solving the color deviation problem.

[0050] Specifically, the reflective sheet 80 disclosed in this embodiment is provided with a non-display area with a width greater than or equal to 2 mm. By providing the non-display area, light leakage from the light-emitting surface of the backlight module can be avoided. Figure 7 As shown, the width of the color complementary coating applied in the display area A of the reflective sheet 80 is k, and the value of k is set within 0-0.5 mm; the width of the color complementary coating applied in the non-display area B is n, and the value of n is set greater than 2 mm.

[0051] Specifically, in order to better avoid the problem of edge light leakage, the concentration of the color complementary coating is based on the color coordinates of the module under the white screen. Figure 1 In the coordinate system, the module white coordinate x is generally set to 0.280~0.33, and y is set to 0.28~0.33.

[0052] Specifically, in the present embodiment, since the light guide plate 20 partially overlaps with the middle frame 30, there is a partial non-display area. In the present embodiment, the width of the non-display area of ​​the light guide plate 20 is set to be greater than or equal to 1.5 mm, so that the edge position of the light guide plate 20 can be avoided from being seen from the front of the backlight module, that is, the light emitting surface; similarly, the width of the non-display area on the quantum dot film in the present embodiment is set to be greater than or equal to 2 mm, so that the light substrate emitted from the display area is all light derived from the light guide plate 20, and the light seen from the front of the backlight module is converted into white light through the optical film 70, so that the light emission uniformity is good and the visual effect is good.

[0053] Specifically, as another implementation of this embodiment, the middle frame 30 is disclosed to be a plastic middle frame 30. The plastic material has a low thermal conductivity, which is beneficial for heat insulation, reducing the heat in the closed inner cavity 50 from being transferred to the optical film 70 through the middle frame 30, and preventing the optical film 70 from failing at the position where it contacts the middle frame 30.

[0054] See also Figure 6 As another implementation of this embodiment, it is disclosed that the middle frame 30 is a double-layer or multi-layer step structure, and the cavity space corresponding to the bottom step close to the light guide plate 20 accommodates the optical film 70, and the cavity space corresponding to the top step accommodates the liquid crystal glass 90, so that the light output surface of the backlight module is flat and does not protrude from the middle frame 30. The middle frame 30 can protect the optical film 70 and the liquid crystal glass 90, while shielding its side wall 11 to avoid the problem of side light leakage.

[0055] As another embodiment of the present application, a liquid crystal display device is disclosed, which includes any backlight module as described above.

[0056] In summary, the present application discloses a backlight module, which includes a back panel structure 10, a light guide plate 20, a middle frame 30, a baffle structure 40 and a light source 60, wherein the edge of the back panel structure 10 is bent to form a side wall 11; the light guide plate 20 is arranged at the middle position of the back panel structure 10; the middle frame 30 is arranged on the side wall 11, and the middle frame 30 extends to above the light emitting surface of the light guide plate 20; the baffle structure 40 is arranged on the middle frame 30, and is located between the middle frame 30 and the light guide plate 20; the back panel structure 10, the middle frame 30, the light guide plate 20 and the baffle structure 40 form a closed inner cavity 50; the light source 60 is arranged in the closed inner cavity 50, and is used to emit light to the light guide plate 20. The backlight module disclosed in this embodiment is provided with a blocking structure 40 between the middle frame 30 and the light guide plate 20, so as to form a closed inner cavity 50, and the light source 60 is provided in the closed inner cavity 50, separated from other components; when the backlight module is working, components such as the optical film 70 and the liquid crystal glass 90 are provided on the middle frame 30, and are located outside the closed inner cavity 50. Only one side of the optical film 70 close to the light source 60 can be provided on the upper side of the middle frame 30, and is located outside the closed inner cavity 50, or the optical film 70 can be completely placed on the middle frame 30. Upper side; the heat generated by the light source 60 when it emits light diffuses in the closed inner cavity 50, but will not be directly transmitted to the surface of the optical film 70, reducing the impact of the heat generated by the light source 60 on the optical film 70, which is beneficial to reducing the temperature of the surface of the optical film 70, ensuring that the operating temperature of the optical film 70 does not exceed its safe temperature during operation, reducing the occurrence of failure of the optical film 70, improving the use efficiency of the optical film 70, extending the overall service life of the backlight module, and allowing all components of the backlight module to work normally, thereby emitting white light normally.

[0057] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application may be combined with each other.

[0058] It should be noted that the present invention takes a display device as an example to introduce the specific structure and working principle of the present invention, but the application of the present invention is not limited to the backlight module of the display device, and can also be applied to the production and use of other similar workpieces.

[0059] It should be understood that the present invention is not limited to the exact construction that has been described above and shown in the drawings and that various modifications and changes may be made without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

[0060] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A backlight module, characterized in that: include: A back plate structure, wherein the edge of the back plate structure is bent to form a side wall; A light guide plate, arranged in the middle of the back plate structure; A middle frame is disposed on the side wall, and the middle frame extends above the light emitting surface of the light guide plate; A blocking structure is provided on the middle frame and is located between the middle frame and the light guide plate; the back plate structure, the middle frame, the light guide plate and the blocking structure form a closed inner cavity; as well as A light source, disposed in the closed inner cavity, for emitting light toward the light guide plate; The baffle structure includes an adhesive layer, a light absorbing layer and a heat insulating layer, one side of the adhesive layer is bonded to the surface of the middle frame, and the other side is connected to the light absorbing layer; the heat insulating layer is connected to the light absorbing layer and is located on the side of the baffle structure facing the light source; The back panel structure includes a back frame and a heat dissipation bar fixed on the back frame, one side of the heat dissipation bar is bent to form the side wall, and the light guide plate, the blocking structure and the middle frame are stacked in sequence on the other side; the heat dissipation bar, the light guide plate, the blocking structure and the middle frame form the closed inner cavity, and the light source is fixed on the heat dissipation bar at a position opposite to the side of the light guide plate; The surfaces of the back frame and the heat dissipation strips are coated with heat dissipation coatings; the heat dissipation strips are detachably matched with the back frame.

2. The backlight module according to claim 1, characterized in that: The heat dissipation coating is a nano heat dissipation coating layer coated by nano coating technology.

3. The backlight module according to claim 1, characterized in that: The light source comprises a light emitting element and a substrate, wherein the light emitting element is fixed on the substrate; a groove is arranged on the heat dissipation bar, and the substrate extends and is inserted into the groove.

4. The backlight module according to claim 3, characterized in that: A heat-conducting adhesive layer is arranged in the groove, and the substrate is bonded to the heat dissipation strip via the heat-conducting adhesive layer.

5. The backlight module according to claim 1, characterized in that: The backlight module also includes a reflective sheet, which is arranged on the back panel and is used to reflect the light emitted by the light source to the light guide plate; wherein the edge of the reflective sheet is also coated with a color complementary coating, and the color of the color complementary coating is complementary to the color of the light emitted by the light source.

6. The backlight module according to claim 1, characterized in that: The middle frame is a plastic middle frame.

7. A liquid crystal display device, characterized in that: Comprising the backlight module as described in any one of claims 1 to 6.

Images