CN111045253B

CN111045253B - Backlight module and liquid crystal display device

Info

Publication number: CN111045253B
Application number: CN201911398983.8A
Authority: CN
Inventors: 郝玲
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2019-12-30
Filing date: 2019-12-30
Publication date: 2021-12-28
Anticipated expiration: 2039-12-30
Also published as: CN111045253A

Abstract

The embodiment of the application provides a backlight module and a liquid crystal display device, relates to the technical field of display, and improves the installation stability of a light conversion layer, so that the installation yield of the light conversion layer is improved. The backlight module comprises: a substrate; a light emitting area; the light sources are positioned on the substrate and positioned in the light emitting area; a transparent encapsulation layer covering the plurality of light sources; the light conversion layer is positioned on one side, back to the substrate, of the transparent packaging layer and covers the light emitting area, and the light conversion layer comprises a color conversion material; the optical film material is positioned on one side, back to the substrate, of the transparent packaging layer, and the optical film material covers the light emitting area. The technical scheme of the application is mainly used for providing backlight for the liquid crystal display panel.

Description

Backlight module and liquid crystal display device

Technical Field

The present disclosure relates to display technologies, and particularly to a backlight module and a liquid crystal display device.

Background

The backlight module is an important component of the liquid crystal display device and is used for providing a light source with sufficient brightness and uniform distribution for the liquid crystal display panel. The backlight module comprises an edge-type backlight module and a direct-type backlight module, and compared with the edge-type backlight module, the direct-type backlight module has the advantages of high contrast and the like, and becomes a development trend in recent years. At present, a direct-type backlight module generally uses a blue light emitting diode as a light source, and converts blue light emitted by the blue light emitting diode into white light required by a liquid crystal display panel by using a color conversion structure. However, the conventional color conversion structure has a small size and is easy to fall off, so that the mounting yield is low.

Disclosure of Invention

The technical scheme of the application provides a backlight unit and liquid crystal display device, has improved the installation stability of light conversion layer, and then has improved the installation yield of light conversion layer.

In a first aspect, the present application provides a backlight module, including: a substrate; a light emitting area; a plurality of light sources located on the substrate, the plurality of light sources being located in the light exit region; a transparent encapsulation layer covering the plurality of light sources; a light conversion layer located on a side of the transparent encapsulation layer opposite to the substrate, the light conversion layer covering the light exit region, the light conversion layer including a color conversion material; the optical film material is positioned on one side, back to the substrate, of the transparent packaging layer, and the optical film material covers the light emitting area.

It can be seen that, encapsulate the back with a plurality of light sources through transparent encapsulating layer, through set up a light conversion layer again on transparent encapsulating layer, just can realize carrying out the colour conversion to the light that all light sources sent, need not to correspond every light source again and set up the colour conversion structure alone, compare in the less colour conversion structure of size among the prior art, the stability of the light conversion layer that the whole face set up in backlight unit is higher, be difficult for droing, make light conversion layer have higher installation stability, the installation yield has been improved, and, can also reduce the cost of manufacture.

In addition, in the backlight module in this application embodiment, when the color conversion material in the light conversion layer performs color conversion on the light emitted by the light source, there is also an ion excitation phenomenon, and the light emitted by the light source is diffused to a certain extent, so as to realize light mixing to a certain extent.

In one possible design, the light conversion layer includes a transparent substrate and the color conversion material coated on a side of the transparent substrate opposite to the substrate, and the light transmittance of the light conversion layer is improved by forming the substrate of the light conversion layer with the transparent material, so that light loss is reduced while color conversion is realized.

In one possible design, the color conversion material comprises a phosphor material or a quantum dot material, wherein the particle size of the phosphor material is d1, d1 is larger than or equal to 2 μm and smaller than or equal to 50 μm, the particle size of the quantum dot material is d2, d2 is larger than or equal to 2nm and smaller than or equal to 100nm, and the particle size of the phosphor material or the quantum dot material is set within the above range, so that the formed backlight color gamut is larger, and the contrast is improved.

In a possible design, the transparent substrate is a diffusion film, at this time, the optical film material comprises a first prism film and a second prism film, the first prism film and the second prism film are located on one side of the color conversion material, which faces away from the substrate, the transparent substrate is set as the diffusion film, so that the diffusion effect of the diffusion film on light rays can be improved, the diffusion film does not need to be arranged in the optical film material, and the thickness of the backlight module is reduced.

In a possible design, the transparent substrate is a first prism film, at this moment, the optical film material comprises a diffusion film and a second prism film, wherein the diffusion film is located between the first prism film and the transparent packaging layer, the transparent substrate is set as the first prism film, the diffusion film is arranged between the first prism film and the transparent packaging layer, light is diffused and corrected at the bottom of the backlight module, the light mixing effect can be optimized, the optical film material does not need to be provided with the first prism film, and the whole thickness of the backlight module is reduced.

In one possible design, the backlight module includes a diffusion film, a light exit region of the diffusion film includes a plurality of sub light exit regions arranged in a matrix, the sub light exit regions include a central light exit region and a boundary light exit region surrounding the central light exit region, and the boundary light exit region includes a plurality of blocking regions; the diffusion film comprises a first surface and a second surface which are oppositely arranged, wherein the first surface is provided with a first microstructure which is positioned in a region except the barrier region in the sub light emergent region; the diffusion degree of the whole boundary light-emitting area can be reduced by not arranging the first microstructures in the blocking area, and when a liquid crystal display panel displays a picture, the halo phenomenon at the position corresponding to the boundary light-emitting area can be improved, so that the halo phenomenon at the boundary of the whole display picture is improved.

In one possible design, the second surface is provided with a second microstructure, the second microstructure is located in the sub light emergent region, and part of the second microstructure is located in the barrier region; the second microstructures are arranged in the blocking area, so that the blocking area can diffuse to a smaller degree, and the phenomenon that the liquid crystal display panel has dark lines at the position corresponding to the blocking area is improved.

In a possible design, in the sub light-emitting regions, the distribution density of the second microstructures decreases gradually along the direction from the central light-emitting region to the boundary light-emitting region, so that the diffusion degree of light is gradually reduced, the change of the diffusion degree is softer, and the dimming effect is optimized.

In a possible design, in the sub light-emitting regions, the size of the second microstructure is decreased gradually along the direction from the central light-emitting region to the boundary light-emitting region, so that the diffusion degree of light is gradually decreased, the change of the diffusion degree is softer, and the dimming effect is optimized.

In a possible design, the light conversion layer is bonded to the surface of the transparent packaging layer, which faces away from the substrate, through a first transparent adhesive layer, and light emitted by the light source directly penetrates through the first transparent adhesive layer and is incident on the light conversion layer, so that the light acquisition rate is improved.

In one possible design, the optical film is located on a side of the light conversion layer facing away from the substrate; the optical film material is adhered to the surface of the light conversion layer, which is opposite to the substrate, through a second transparent adhesive layer, and light emitted by the light source directly penetrates through the second transparent adhesive layer and is incident to the light conversion layer, so that the light acquisition rate is improved; or, the optical film material and the surface of the light conversion layer back to the substrate are spaced, exemplarily, the surface of the light conversion layer back to the substrate can be dispersedly provided with a plurality of transparent support columns, so that the gap is formed between the optical film material and the light conversion layer, and light emitted by the light source is refracted when being transmitted to the gap, so that the light is diffused, and the light mixing effect is optimized.

In a second aspect, the present application further provides a liquid crystal display device, including a back plate; a front frame; the backlight module is arranged on the back plate through the frame body, and the backlight module is positioned on one side of the liquid crystal display panel, which is back to a light emitting surface of the liquid crystal display device; when the liquid crystal display panel is driven to display, the backlight module provides white backlight for the liquid crystal display panel, and the quantity of emitted light is controlled through the torsion of liquid crystal in the liquid crystal display panel, so that image display is realized.

It can be seen that, because the liquid crystal display device that this application provided includes above-mentioned backlight unit, consequently, adopt this liquid crystal display device, based on the mode of setting up of the light conversion layer among the backlight unit, need not to set up a look conversion structure respectively to every light source, compare in the less look conversion structure of prior art medium-sized, the stability of the light conversion layer that the whole face set up in backlight unit is higher, be difficult for droing for the light conversion layer has higher installation stability, the installation yield has been improved, and, can also reduce the cost of manufacture.

Drawings

In order to more clearly illustrate the detailed description of the present application or the technical solutions in the prior art, the drawings needed to be used in the detailed description of the present application or the prior art description will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative efforts.

FIG. 1 is a schematic diagram of a prior art LCD device;

FIG. 2 is a cross-sectional view taken along the line A1 '-A2' of FIG. 1;

fig. 3 is a schematic structural diagram of a backlight module in a top view according to an embodiment of the invention;

FIG. 4 is a cross-sectional view taken along line A1-A2 of FIG. 3;

FIG. 5 is a schematic structural diagram of an optical film according to an embodiment of the present disclosure;

FIG. 6 is a schematic diagram of a structure of a light conversion layer according to an embodiment of the present application;

FIG. 7 is a schematic view of another structure of a backlight module according to an embodiment of the present application;

FIG. 8 is a schematic view of another structure of a backlight module according to an embodiment of the present application;

FIG. 9 is a schematic view of a diffusion film according to an embodiment of the present application in a top view;

FIG. 10 is a cross-sectional view taken along line B1-B2 of FIG. 9;

FIG. 11 is a schematic view of a first microstructure in a diffusion film according to an embodiment of the present disclosure;

FIG. 12 is another cross-sectional view taken along line B1-B2 of FIG. 9;

FIG. 13 is a cross-sectional view taken along the line C1-C2 in FIG. 9;

FIG. 14 is a schematic view of a distribution of second microstructures in a diffusion film in an embodiment of the present application under a top view;

FIG. 15 is another cross-sectional view taken along the line C1-C2 in FIG. 9;

FIG. 16 is a schematic view of another distribution of second microstructures in a diffuser film of an embodiment of the present application at a top view;

FIG. 17 is a schematic view of an arrangement of a light conversion layer according to an embodiment of the present application;

FIG. 18 is a schematic view of an arrangement of optical films according to an embodiment of the present disclosure;

FIG. 19 is a schematic view of another arrangement of optical films according to the embodiment of the present disclosure;

FIG. 20 is a schematic view of a liquid crystal display device according to an embodiment of the present application;

fig. 21 is a sectional view of a liquid crystal display device in an embodiment of the present application.

Reference numerals:

100' -a liquid crystal display panel;

101' -a backlight module;

1' -a substrate;

a 2' -light source;

3' -color conversion structures;

4' -optical film material;

1-a substrate;

200-a light emitting area;

2-a light source;

3-a transparent encapsulation layer;

a 4-light converting layer;

41-a transparent substrate;

42-a color converting material;

5-optical film material;

51-a diffusion membrane;

511-light emitting area;

512-sub light emitting area;

513-a central light exit area;

514-boundary light out area;

515-a barrier region;

516-a first surface;

517-a second surface;

518-a first microstructure;

519-a second microstructure;

52-a first prismatic film;

53-a second prismatic film;

6-a first transparent adhesive layer;

7-a second transparent adhesive layer;

8-clearance;

9-transparent support columns;

100-a back plate;

101-front frame;

102-a liquid crystal display panel;

103-a backlight module;

104-frame body.

Detailed Description

The technical solutions of the present application will be described clearly in the following with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present application. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

To describe the technical solution of the present application more clearly, the present application first explains the structure and the operation principle of the conventional liquid crystal display device: as shown in fig. 1, fig. 1 is a schematic structural diagram of a liquid crystal display device in the prior art, the liquid crystal display device is a display device for displaying images by using a liquid crystal power-up torsion principle, and the liquid crystal display device includes a liquid crystal display panel 100 ' and a backlight module 101 ', wherein liquid crystal molecules are disposed in the liquid crystal display panel 100 ', and since the liquid crystal molecules do not emit light, white backlight needs to be provided to the liquid crystal display panel by using the backlight module 101 ', and further the amount of light emitted is controlled by torsion of the liquid crystal, and the emitted light passes through a color filter to realize normal image display, therefore, a light source is generally disposed in the backlight module 101 '. In a conventional backlight module, red, green and blue light emitting diodes are used as light sources, and three colors of light are uniformly mixed to form white light with a certain chromaticity, but the chromaticity of the formed white light is shifted due to the inconsistent characteristics of the red, green and blue light emitting diodes, so that the current mainstream backlight module generally adopts the blue light emitting diodes as the light sources to improve the influence on the chromaticity.

Fig. 2 is a cross-sectional view taken along a direction a1 ' -a2 ' of fig. 1, and as shown in fig. 2, a backlight module 101 ' includes a substrate 1 ', a plurality of light sources 2 ' mounted on the substrate 1 ', a plurality of color conversion structures 3 ' and an optical film 4 ', wherein each light source 2 ' is encapsulated by a color conversion structure 3 ', such as an encapsulation layer formed by a phosphor material, so as to convert colored light emitted by the light source 2 ' into white light required by a liquid crystal display panel; the optical film material 4 ' is located on one side of the color conversion structure 3 ' facing the light emitting surface, and is used for mixing and brightening the white light converted by the color conversion structure 3 ', so as to provide a backlight with sufficient brightness and uniform distribution for the liquid crystal display panel. It can be seen that, by adopting the existing color conversion structures 3 ', the color conversion structures 3 ' are arranged in one-to-one correspondence with the light sources 2 ', and the size of each color conversion structure 3 ' is small, so that the color conversion structures 3 ' are poor in installation stability and easy to fall off, and the installation yield is low.

Referring to the drawings, a technical solution related to an embodiment of the present application is described below, where fig. 3 is a schematic structural diagram of a backlight module provided in an embodiment of the present invention in a top view, and fig. 4 is a cross-sectional view taken along a direction a1-a2 in fig. 3, as shown in fig. 3 and fig. 4, a backlight module provided in an embodiment of the present application includes: a substrate 1; a light exit area 200; the light sources 2 are positioned on the substrate 1, and the light sources 2 are positioned in the light-emitting area 200, wherein the substrate 1 may be a printed circuit board, the light sources 2 may be light-emitting diodes, such as blue light-emitting diodes, and the light sources 2 are mounted on the substrate 1 by a surface mount technology array and electrically connected to the substrate 1, so as to realize light emission under the action of a power supply provided by the substrate 1; a transparent encapsulation layer 3, the transparent encapsulation layer 3 covering the plurality of light sources 2, and after the light sources 2 are formed, a layer of encapsulation material is coated on the light sources 2 and dried, thereby forming the transparent encapsulation layer 3; the light conversion layer 4 is positioned on one side, opposite to the substrate 1, of the transparent packaging layer 3, the light conversion layer 4 covers the light emitting area 200, the light conversion layer 4 comprises a color conversion material, the color conversion material has color conversion characteristics and can convert colored light emitted by the light source 2 into white light required by a liquid crystal display panel, and the light conversion layer 4 can be set to be a single-layer structure in order to reduce the overall thickness of the backlight module; and the optical film material 5 is positioned on one side of the transparent packaging layer 3, which faces away from the substrate 1, the optical film material 5 covers the light emitting area 200, and the optical film material 5 is used for mixing and brightening the light emitted by the plurality of light sources 2 to form a uniformly distributed surface light source. For example, fig. 5 is a schematic structural diagram of an optical film in an embodiment of the present disclosure, as shown in fig. 5, the optical film 5 may include a diffusion film 51, a first prism film 52 and a second prism film 53, and referring to fig. 4, after color conversion is performed on light emitted from the light source 2 through the light conversion layer 4, the light enters the diffusion film 51, a microstructure (e.g., a prism) in the diffusion film 51 is used to refract the light irregularly to widen a viewing angle, the diffused light further enters the first prism film 52, the microstructure (e.g., a prism) in the first prism film 52 is used to correct the exit angle of the light to a certain extent, after the emitted light enters the second prism film 53, the microstructure (e.g., a prism) in the second prism film 53 is used to further correct the exit angle of the light, so that the light exits along a direction perpendicular to a plane of the backlight module, thereby achieving brightness enhancement.

In addition, referring to fig. 3 and fig. 4 again, the backlight module further includes an outer frame 10 and a light shielding structure 11, wherein the light shielding structure 11 is located on one side of the optical film 5 facing the light exit surface, and the light shielding structure 11 is disposed around an edge of the backlight module and is configured to shield light emitted from the edge of the backlight module, so as to reduce the amount of light incident from the edge of the backlight module to the liquid crystal display panel, thereby effectively improving the edge light leakage phenomenon of the liquid crystal display panel.

In the backlight unit in this application embodiment, encapsulate the back with a plurality of light sources 2 through transparent encapsulation layer 3, through set up a light conversion layer 4 again on transparent encapsulation layer 3, just can realize carrying out the colour conversion to the light that all light sources 2 sent, need not to correspond every light source 2 again and set up the colour conversion structure alone, the colour conversion structure that the size is less among the prior art relatively, the stability of light conversion layer 4 that the whole face set up is higher in backlight unit, be difficult for droing, make light conversion layer 4 have higher installation stability, the installation yield has been improved, and, can also reduce the cost of manufacture.

In addition, in the backlight module in the embodiment of the present application, when the color conversion material in the light conversion layer 4 performs color conversion on the light emitted by the light source 2, an ion excitation phenomenon also exists, the light emitted by the light source 2 is diffused to a certain degree, so that light mixing to a certain degree is realized, and after further performing secondary light mixing through the optical film material 5, the light mixing effect can be improved, so that a more uniform surface light source is formed.

In a possible implementation manner, fig. 6 is a schematic structural diagram of a light conversion layer in an embodiment of the present application, and as shown in fig. 6, the light conversion layer 4 includes: a transparent substrate 41; a color conversion material 42 coated on the side of the transparent base 41 facing away from the substrate 1. The transparent substrate 41 may be formed of a material with high transmittance such as polyethylene terephthalate (PET), Polycarbonate (PC), polymethyl methacrylate (PMMA), etc., so as to improve the light transmittance of the light conversion layer 4, and reduce light loss while realizing color conversion.

Optionally, the color conversion material 42 includes a phosphor material, the particle size of the phosphor material is d1, and d1 satisfies: d1 is more than or equal to 2 mu m and less than or equal to 50 mu m. The phosphor material can be formed by materials such as nitrogen oxide, fluoride, silicate and the like, and can be formed by mixing phosphors with various colors according to a certain proportion, such as a red phosphor material and a green phosphor material. And the fluorescent powder material with the grain diameter ranging from 2 micrometers to 50 micrometers is selected, so that the formed backlight has a larger color gamut, and higher contrast is realized.

In specific implementation, the phosphor material and the transparent glue can be mixed according to a certain ratio and coated on the transparent substrate 41, so as to realize the stable combination of the phosphor material and the transparent substrate 41. The following description will specifically describe the process of forming the light conversion layer 4 by taking as an example that the phosphor material is mixed with the red phosphor material and the green phosphor material:

firstly, according to a backlight color point, mixing a red fluorescent powder material and a green fluorescent powder material according to a certain proportion, and simultaneously adding transparent optical silica gel; then, fully stirring the mixture, and setting stirring time and stirring times according to the uniformity of the actual coated sample, wherein if the stirring time and the stirring times are set to be 3-4 times, the stirring time is set to be 5-10 minutes each time; finally, the transparent substrate 41 and the mixture are fixed by means of screen printing to improve the flatness, and ultraviolet light source curing is performed after printing.

Alternatively, the color conversion material 42 may also include a quantum dot material, and the particle size of the quantum dot material is d2, so that in order to make the formed backlight color gamut larger and achieve higher contrast, d2 may satisfy: d2 is more than or equal to 2nm and less than or equal to 100 nm.

In a possible implementation manner, fig. 7 is a schematic structural diagram of a backlight module in an embodiment of the present application, and as shown in fig. 7, the transparent substrate 41 is a diffusion film 51; the optical film 5 includes a first prism film 52 and a second prism film 53, and the first prism film 52 and the second prism film 53 are located on a side of the color conversion material 42 facing away from the substrate. In this implementation, the light conversion layer 4 has the diffusion film 51 as the transparent substrate 41, and the color conversion material 42 is coated on the diffusion film 51, wherein the transparent substrate 41 (diffusion film 51) can be formed by using a material with high transmittance such as PET, PC, PMMA, etc., and the thickness of the diffusion film 51 can be set to be between 30 μm and 200 μm according to actual requirements.

The transparent substrate 41 is set as a diffusion film 51, and the diffusion film 51 has a microstructure (such as a prism) and can diffuse light emitted by a light source, so that the transparent substrate 41 has the functions of bearing the color conversion material 42 and diffusing light, that is, the light conversion layer 4 has the functions of diffusion and color conversion, and on one hand, the diffusion film 51 is positioned at one side close to the light source 2, the light emitted by the light source 2 is firstly diffused through the diffusion film 51, the diffused light is subjected to color conversion through the light conversion layer 4, and the light is diffused near the bottom of the backlight module, so that the light is more diffused, the diffusion effect is remarkable, and the light mixing effect is further optimized; on the other hand, the optical film material 5 only needs to be provided with the first prism film 52 and the second prism film 53, and does not need to be provided with a diffusion film, so that the overall thickness of the backlight module is reduced.

In a possible implementation manner, fig. 8 is a schematic structural diagram of a backlight module in an embodiment of the present application, as shown in fig. 8, the transparent substrate 41 is a first prism film 52, and the optical film 5 includes a diffusion film 51 and a second prism film 53, where the diffusion film 51 is located between the first prism film 52 and the transparent encapsulation layer 3. In this implementation, the color conversion material 42 is coated on the first prism film 52 in the light conversion layer 4 with the first prism film 52 as the transparent substrate 41. In this case, the first prism film 52 may be formed using a material having high transmittance such as PET, PC, or PMMA.

The transparent substrate 41 is set as a first prism film 52, a diffusion film 51 in the optical film material 5 is arranged between the first prism film 52 and the transparent packaging layer 3, light emitted by the light source 2 is firstly diffused through the diffusion film 51, the diffused light is corrected to a certain extent through the first prism film 52, then color conversion is carried out through the color conversion material 42, and the light is diffused and corrected at the bottom of the backlight module, so that the light mixing effect can be optimized. In addition, after the transparent substrate 41 is provided with the first prism film 52, only the diffusion film 51 and the second prism film 53 need to be provided in the optical film 5, and the first prism film does not need to be provided, so that the overall thickness of the backlight module is reduced.

In a possible implementation manner, fig. 9 is a schematic structural diagram of a diffusion film in a top-down view in the embodiment of the present disclosure, as shown in fig. 9, the backlight module includes a diffusion film 51, a light exit region 511 of the diffusion film 51 includes a plurality of light exit sub-regions 512 arranged in a matrix, a number of the light exit sub-regions 512 may be defined according to actual requirements, each light exit sub-region 512 includes a central light exit region 513 and a boundary light exit region 514 surrounding the central light exit region 513, fig. 10 is a cross-sectional view along a direction B1-B2 in fig. 9, fig. 11 is a schematic distribution diagram of first microstructures in the diffusion film in the embodiment of the present disclosure in a top-down view, as shown in fig. 10 and fig. 11, the boundary light exit region 514 includes a plurality of barrier regions 515; the diffusion film 51 includes a first surface 516 and a second surface 517 disposed oppositely, wherein the first surface 516 is provided with a first microstructure 518 (e.g., a prism), the first microstructure 518 is located in a region of the light emergent sub-region 512 except for the blocking region 515, and light is reflected and refracted in the first microstructure 518 to realize diffusion.

It should be noted that when the diffusion film 51 is used as the transparent substrate 41 in the light conversion layer 4, the backlight module including the diffusion film 51 specifically means that the light conversion layer 4 in the backlight module includes the diffusion film 51, and when the diffusion film 51 is not used as the transparent substrate 41 in the light conversion layer 4, the backlight module including the diffusion film 51 specifically means that the optical film 5 in the backlight module includes the diffusion film 51.

In the conventional backlight module, the diffusion effect of the whole area of the diffusion film is uniform, and when a liquid crystal display panel displays a picture, a halo phenomenon is easily generated. For example, when the lcd panel displays a white image in a black image, the light is scattered in the whole area of the diffusion film of the backlight module, so that there is a light leakage phenomenon at the boundary of the white image, which results in that the boundary of the white image cannot present an ideal black state and generates halo. In the embodiment of the present application, the light exiting region 511 of the diffusion film 51 is divided into a plurality of sub light exiting regions 512, a boundary light exiting region 514 is divided in each sub light exiting region 512, a blocking region 515 is further disposed in the boundary light exiting region 514, and the diffusion of light in the blocking region 515 is reduced by using a mode that the blocking region 515 is not provided with the first microstructure 518, so that the diffusion degree of the whole boundary light exiting region 514 is reduced, local dimming is realized, when a liquid crystal display panel displays a picture, a halo phenomenon at a position corresponding to the boundary light exiting region 514 can be improved, and a halo phenomenon at the boundary of the whole display picture can be improved.

In addition, it should be noted that the sizes of the plurality of blocking regions 515 included in the boundary light-exiting region 514 may be different, and specifically, with reference to fig. 11, in the boundary light-exiting region 514, for the partial regions located at both sides of the central light-exiting region 513 in the first direction, the length of the partial regions in the second direction is the same as the length of the sub light-exiting region 512 in the second direction, so that when the blocking regions 515 are divided in the partial boundary light-exiting region 514, the partial blocking regions 515 may have a larger length in the second direction; however, the length of the partial region on the second direction of the central light exit region 513 is smaller, and therefore, when the blocking region 515 is divided in the partial boundary light exit region 514, the length of the partial blocking region 515 in the second direction is correspondingly smaller. The specific size, area and shape of the blocking region 515 may be set according to the actual size of the boundary light-emitting region 514, which is not particularly limited by the embodiment of the present application.

In one possible implementation, fig. 12 is another cross-sectional view taken along direction B1-B2 in fig. 9, and as shown in fig. 12, a second surface 517 of the diffusion film 51 is provided with second microstructures 519, the second microstructures 519 are located in the light exit sub-regions 512, and a portion of the second microstructures 519 are located in the blocking regions 515. In this way, the first microstructure 518 and the second microstructure 519 are arranged in the region of the sub light-emitting region 512 except the blocking region 515, so that the light diffusion degree is relatively strong, and the light diffusion degree is weakened compared with other regions because only the second microstructure 519 is correspondingly arranged in the blocking region 515 of the boundary light-emitting region 514. Moreover, on the premise that the light diffusion degree of the boundary light-emitting area 514 is reduced compared with other areas, the second microstructures 519 are arranged on the blocking area 515, so that the blocking area 515 is diffused to a certain degree, the situation that the backlight module is not subjected to light emission at the position corresponding to the blocking area 515 due to no diffusion of the blocking area 515 is improved, and the phenomenon that the liquid crystal display panel has dark lines at the position corresponding to the blocking area 515 is effectively improved.

In one possible implementation manner, fig. 13 is a cross-sectional view taken along a direction C1-C2 in fig. 9, and fig. 14 is a schematic view of distribution of the second microstructures in the diffusion film in the embodiment of the present application in a top view, and as shown in fig. 13 and fig. 14, in the sub light exit area 512, distribution density of the second microstructures 519 decreases along a direction from the central light exit area 513 to the boundary light exit area 514. Specifically, referring to fig. 9, the sub light exit area 512 includes four edges connected end to end and a geometric center O, and a direction of the central light exit area 513 toward the boundary light exit area 514 refers to a direction pointing from the geometric center O to any one of the edges. In this implementation, the distribution density of the second microstructures 519 decreases along the direction from the central light-emitting region 513 to the boundary light-emitting region 514, so that the light diffusion degree gradually decreases from the central light-emitting region 513 to the boundary light-emitting region 514, the change is soft, and the dimming effect is optimized.

In addition, the degree of attenuation of the distribution density of the second microstructures 519 in different regions can be adaptively adjusted according to factors such as the actual area and size of the barrier region 515, while ensuring that the distribution density of the second microstructures 519 in the entire region decreases in the direction from the central light-emitting region 513 toward the boundary light-emitting region 514. For example, if the area of a certain blocking region 515 is larger, the attenuation degree of the distribution density of the second microstructures 519 in the blocking region 515 can be set to be slightly smaller, so as to increase the number of the second microstructures 519 distributed in the blocking region 515 to a certain extent, and avoid the light diffusion degree in the blocking region 515 to be too low, so as to further optimize the dimming effect.

In one possible implementation, fig. 15 is another cross-sectional view taken along a direction C1-C2 in fig. 9, and fig. 16 is another distribution diagram of the second microstructures in the diffusion film in the embodiment of the present application under a top view, and as shown in fig. 15 and fig. 16, in the sub light exit area 512, the size of the second microstructures 519 decreases along the central light exit area 513 toward the boundary light exit area 514. Specifically, referring to fig. 9, the sub light exit area 512 includes four edges connected end to end and a geometric center O, and a direction of the central light exit area 513 toward the boundary light exit area 514 refers to a direction pointing from the geometric center O to any one of the edges. In this implementation, the size of the second microstructures 519 decreases gradually along the direction from the central light-emitting region 513 to the boundary light-emitting region 514, so that the light diffusion degree gradually decreases from the central light-emitting region 513 to the boundary light-emitting region 514, the light diffusion degree changes softly, and the dimming effect is optimized.

In addition, the degree of attenuation of the second microstructures 519 in different regions can be adaptively adjusted according to factors such as the actual area and size of the blocking region 515, while ensuring that the size of the second microstructures 519 in the entire region decreases in the direction from the central light-emitting region 513 to the boundary light-emitting region 514. For example, if the area of a certain blocking region 515 is larger, the attenuation degree of the second microstructure 519 size in the blocking region 515 can be set to be slightly smaller, so as to increase the diffusion degree of the second microstructure 519 in the blocking region 515 to light to some extent, and avoid the light diffusion degree in the blocking region 515 to be too low, so as to further optimize the dimming effect.

In addition, it should be noted that in the embodiment of the present application, the shapes and sizes of the first microstructure 518 and the second microstructure 519 can be set according to actual requirements, for example, the first microstructure 518 and the second microstructure 519 can be a cube, a cone, a hemisphere or the like with a size of several micrometers to several tens of micrometers.

In a possible implementation manner, fig. 17 is a schematic view of an arrangement manner of a light conversion layer in an embodiment of the present application, as shown in fig. 17, a light conversion layer 4 is adhered to a surface of a transparent encapsulation layer 3 opposite to a substrate 1 through a first transparent adhesive layer 6, so that light emitted by a light source 2 directly penetrates through the first transparent adhesive layer 6 and is incident on the light conversion layer 4, and a light obtaining rate is improved.

Or, a gap may also be provided between the light conversion layer 4 and the transparent encapsulation layer 3, for example, a plurality of transparent support pillars may be provided on a side of the transparent encapsulation layer 3 facing away from the substrate 1, and the light conversion layer 4 formed in advance is placed on the transparent support pillars, and the light conversion layer 4 is supported by the transparent support pillars, so as to achieve that a gap is left between the light conversion layer 4 and the transparent encapsulation layer 3, and it should be noted that, because the light conversion layer 4 has a certain thickness, the light conversion layer 4 can maintain the surface flat under the support of the transparent support pillars, so that a gap exists between the light conversion layer 4 and the transparent encapsulation layer 3, and because the air in the gap has a certain refractive index, the light emitted by the light source 2 is refracted when being transmitted to the air gap, thereby achieving a certain degree of diffusion, and optimizing the light mixing effect.

In a possible implementation manner, fig. 18 is a schematic view of an arrangement manner of an optical film in the embodiment of the present application, as shown in fig. 18, an optical film 5 is located on a side of the light conversion layer 4 facing away from the substrate 1; the optical film material 5 is adhered to the surface of the light conversion layer 4 opposite to the substrate 1 through the second transparent adhesive layer 7, so that light emitted by the light source 2 directly penetrates through the second transparent adhesive layer 7 to be incident on the light conversion layer 4, and the light acquisition rate is improved; or, fig. 19 is a schematic view of another arrangement manner of the optical film in the embodiment of the present application, as shown in fig. 19, a gap 8 is formed between the optical film 5 and the surface of the light conversion layer 4 facing away from the substrate 1, and light emitted by the light source 2 is refracted when being transmitted to the gap 8, so that the light is diffused, and the light mixing effect is optimized; for example, referring to fig. 19 again, a plurality of transparent supporting pillars 9 may be disposed on a surface of the light conversion layer 4 opposite to the substrate 1, and a gap is left between the light conversion layer 4 and the optical film 5 by placing the preformed optical film 5 on the transparent supporting pillars 9 and supporting the optical film 5 with the transparent supporting pillars 9, in this way, the transparent supporting pillars 9 can stably support the optical film 5 while the gap 8 is formed between the optical film 5 and the light conversion layer 4, so as to improve the flatness of the optical film 5.

Fig. 20 is a schematic structural diagram of a liquid crystal display device in an embodiment of the present application, fig. 21 is a cross-sectional view of the liquid crystal display device in the embodiment of the present application, and as shown in fig. 20 and fig. 21, the embodiment of the present application further provides a liquid crystal display device, including: a back plate 100; a front frame 101; the liquid crystal display device comprises a liquid crystal display panel 102 and the backlight module 103, wherein the liquid crystal display panel 102 is installed in an accommodating space formed by a back plate 100 and a front frame 101 through a frame 104, the backlight module 103 is installed on the back plate 100 through the frame 104, and the backlight module 103 is located on one side of the liquid crystal display panel 102, which faces away from a light emitting surface of the liquid crystal display device. The specific structure of the backlight module 103 has been described in detail in the above embodiments, and is not described herein again. Note that the liquid crystal display device may be any electronic device having a display function, such as a mobile phone, a tablet computer, a notebook computer, an electronic book, or a television.

The application provides a liquid crystal display device includes above-mentioned backlight unit 103, therefore, adopt this liquid crystal display device, based on the setting mode of light conversion layer 4 among backlight unit 103, need not to set up a look conversion structure respectively to every light source 2, compare in the less look conversion structure of prior art medium-sized, the stability of light conversion layer 4 that the whole face set up in backlight unit is higher, be difficult for droing, make light conversion layer 4 have higher installation stability, the installation yield has been improved, and, can also reduce the cost of manufacture.

The above description is only a preferred embodiment of the present application and is not intended to limit the present application, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A backlight module, comprising:

a substrate;

a light emitting area;

a plurality of light sources located on the substrate, the plurality of light sources being located in the light exit region;

a transparent encapsulation layer covering the plurality of light sources;

a light conversion layer located on a side of the transparent encapsulation layer opposite to the substrate, the light conversion layer covering the light exit region, the light conversion layer including a color conversion material;

the optical film material is positioned on one side, back to the substrate, of the transparent packaging layer, and the optical film material covers the light emitting area;

the light emitting area of the diffusion film comprises a plurality of sub light emitting areas arranged in a matrix form, each sub light emitting area comprises a central light emitting area and a boundary light emitting area surrounding the central light emitting area, and each boundary light emitting area comprises a plurality of barrier areas; the diffusion film comprises a first surface and a second surface which are oppositely arranged, wherein the first surface is provided with a first microstructure which is positioned in a region except the barrier region in the sub light emergent region.

2. The backlight module according to claim 1,

the light conversion layer includes:

a transparent substrate;

the color conversion material is coated on one side, opposite to the substrate, of the transparent substrate.

3. The backlight module according to claim 2,

the color conversion material includes:

the particle size of the fluorescent powder material is d1, and d1 is more than or equal to 2 microns and less than or equal to 50 microns;

or the particle size of the quantum dot material is d2, and d2 is more than or equal to 2nm and less than or equal to 100 nm.

4. A backlight module according to claim 2 or 3,

the transparent substrate is a diffusion film;

the optical film material comprises a first prism film and a second prism film, and the first prism film and the second prism film are positioned on one side, opposite to the substrate, of the color conversion material.

5. A backlight module according to claim 2 or 3,

the transparent substrate is a first prism film;

the optical film material comprises a diffusion film and a second prism film, wherein the diffusion film is positioned between the first prism film and the transparent packaging layer.

6. The backlight module according to claim 1,

the second surface is provided with a second microstructure, the second microstructure is located in the sub light emergent region, and part of the second microstructure is located in the barrier region.

7. A backlight module according to claim 6, wherein the distribution density of the second microstructures in the sub light exit regions decreases along the direction from the central light exit region to the boundary light exit region.

8. A backlight module according to claim 6, wherein the size of the second microstructures in the sub light exit regions decreases along the direction from the central light exit region to the boundary light exit region.

9. The backlight module according to claim 1,

the light conversion layer is adhered to the surface, back to the substrate, of the transparent packaging layer through a first transparent adhesive layer.

10. The backlight module according to claim 1,

the optical film material is positioned on one side of the light conversion layer, which is back to the substrate;

the optical film material is adhered to the surface, back to the substrate, of the light conversion layer through a second transparent adhesive layer; or a gap is arranged between the optical film and the surface of the light conversion layer back to the substrate.

11. A liquid crystal display device, comprising:

a back plate;

a front frame;

the liquid crystal display panel and the backlight module according to any one of claims 1 to 10, wherein the liquid crystal display panel is mounted in the accommodating space formed by the back plate and the front frame through a frame, the backlight module is mounted on the back plate through the frame, and the backlight module is located on a side of the liquid crystal display panel facing away from the light emitting surface of the liquid crystal display device.