CN115185124A

CN115185124A - MiniLED backlight module and display device

Info

Publication number: CN115185124A
Application number: CN202210638822.7A
Authority: CN
Inventors: 杨宇琦; 叶旭华; 巫殷伟; 李健林; 张昌健
Original assignee: Huizhou Shiwei New Technology Co Ltd
Current assignee: Huizhou Shiwei New Technology Co Ltd
Priority date: 2022-06-07
Filing date: 2022-06-07
Publication date: 2022-10-14

Abstract

The embodiment of the application provides a MiniLED backlight unit and display device, includes: the reflective film comprises at least one reflective unit layer; the microstructure diffusion film is stacked on the light emergent side of the reflective film; the backlight lamp panel comprises a circuit substrate and a plurality of MiniLED chips; the MiniLED chips are arranged on the circuit substrate at intervals; the MiniLED chips are opposite to the reflective film and are arranged at intervals; the reflector plate is arranged on one side, facing the reflective film, of the circuit substrate in a mode of avoiding the MiniLED chips; the reflector plate is opposite to the light reflecting film and arranged at intervals to form a light mixing area. The embodiment of the application filters low-angle light, micro-structure diffusion film diffusion light through reflector plate reflection light, reflection unit layer, reduces the mixed light distance to can reduce the thickness of backlight unit and display device complete machine when guaranteeing the even gloss nature of the light from micro-structure diffusion film outgoing.

Description

MiniLED backlight module and display device

Technical Field

The application relates to the technical field of display, especially, relate to a MiniLED backlight unit and display device.

Background

With the development of the lightness and thinness of the television, the light mixing distance of the backlight module is smaller and smaller, namely, the thickness of an air layer between the LED chip and the diffusion plate is smaller and smaller, so that the phenomenon of uneven visual effect is caused. In order to ensure the uniformity of visual effect, one of the methods is to thicken the diffusion plate and overlap the diffusion membrane while reducing the arrangement distance of the LED chips. However, the smaller the arrangement pitch of the LED chips is, the greater the difficulty in controlling the temperature of the whole television is, and thickening the diffusion plate and overlapping the diffusion film increases the weight and thickness of the whole television, which is not favorable for realizing the lightness and thinness of the whole television.

Therefore, how to design a light-weight and thin television with small light mixing distance, large arrangement pitch of the LED chips and uniform visual effect is a technical problem to be solved urgently.

Disclosure of Invention

The embodiment of the application provides a MiniLED backlight unit and display device filters low-angle light, micro-structure diffusion film diffusion light through reflector plate reflection light, reflection unit layer, reduces the mixed light distance to can reduce the thickness of backlight unit and display device complete machine when guaranteeing the even gloss nature of the light from micro-structure diffusion film outgoing.

In a first aspect, an embodiment of the present application provides a MiniLED backlight module, which includes:

the reflective film comprises at least one layer of reflective unit layer, the reflective unit layer comprises a high refractive layer and a low refractive layer which are arranged in a laminated manner, and the refractive index of the high refractive layer is greater than that of the low refractive layer;

the microstructure diffusion film is stacked on the light emergent side of the reflective film;

the backlight lamp panel comprises a circuit substrate and a plurality of MiniLED chips; the MiniLED chips are arranged on the circuit substrate at intervals; the MiniLED chips are opposite to the reflecting film and are arranged at intervals; and

the reflector plate is arranged on one side, facing the reflective film, of the circuit substrate in a mode of avoiding the MiniLED chips; the reflector plate is opposite to the light reflecting film and arranged at intervals to form a light mixing area.

In a second aspect, an embodiment of the present application provides a display device, including:

a MiniLED backlight module; and

a liquid crystal panel.

In the embodiment of the application, the MiniLED chips are used for emitting light; the reflecting unit layer reflects small-angle light rays, allows large-angle light rays to transmit and is used for filtering small-angle light rays; the light reflected by the reflecting unit layer is reflected by the reflecting sheet and then enters the reflecting unit layer again, and the reflecting unit layer filters small-angle light again; the large-angle light rays of the transmission reflection unit layer enter the microstructure diffusion film, and the microstructure diffusion film diffuses light spots formed by the large-angle light rays, so that the light uniformity of the light emitted from the microstructure diffusion film is ensured.

The embodiment of the application filters the combined action of small-angle light and microstructure diffusion film diffusion light through reflector plate reflection light, reflection unit layer, and the facula that every miniLED chip formed obtains enlarging to can realize reducing mixed light distance under the prerequisite of the homogeneity of the whole face light that does not reduce and lose a plurality of miniLED chips formation.

According to the embodiment of the application, the light emitted by the MiniLED chips is homogenized by replacing the diffusion plate with the laminated reflective film and the laminated microstructure diffusion film, and the thickness and the weight of the backlight module and the whole machine can be reduced. Therefore, the embodiment of the application filters small-angle light and the diffusion light of the microstructure diffusion film through the reflection sheet reflection light and the reflection unit layer to reduce the light mixing distance, so that the thickness of the backlight module and the thickness of the whole display device can be reduced while the uniform light of the light emitted from the microstructure diffusion film can be ensured.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings used in the description of the embodiments will be briefly described below. It is obvious that the drawings in the following description are only some embodiments of the application, and that for a person skilled in the art, other drawings can be derived from them without inventive effort.

Fig. 1 is a schematic view of a first structure of a MiniLED backlight module according to an embodiment of the present disclosure.

Fig. 2 is a schematic view of a first structure of the retroreflective sheeting of fig. 1.

Fig. 3 is a schematic view of a second structure of the light-reflecting film shown in fig. 1.

Fig. 4 is a schematic view of a third structure of the light-reflecting film shown in fig. 1.

Fig. 5 is a schematic view of a fourth structure of the light-reflecting film shown in fig. 1.

Fig. 6 is a schematic view of a second structure of a MiniLED backlight module according to an embodiment of the present disclosure.

Fig. 7 is a schematic view of a third structure of a MiniLED backlight module according to an embodiment of the present disclosure.

Fig. 8 is a front view of the microstructured diffusion film of fig. 7.

Fig. 9 is a side view of the microstructured diffusion film of fig. 8.

Fig. 10 is a schematic diagram of a fourth structure of a MiniLED backlight module according to an embodiment of the present application.

Fig. 11 is a fifth structural schematic diagram of a MiniLED backlight module according to an embodiment of the present disclosure.

Fig. 12 is a schematic view of a first structure of a display device according to an embodiment of the present application.

Fig. 13 is a second structural diagram of a display device according to an embodiment of the present application.

Fig. 14 is a schematic diagram of a third structure of a display device according to an embodiment of the present application.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. It should be apparent that the described embodiments are only a few embodiments of the present application, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without inventive step, are within the scope of the present application.

In the description of the present application, it is to be understood that the terms "first", "second", and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implying any number of technical features indicated. It should be understood that for the purposes of this description, a "small angle ray" is used to indicate a ray at an angle of incidence closer to 0, and a "large angle ray" is used to indicate a ray at an angle of incidence closer to 90.

Referring to fig. 1, an embodiment of the present application provides a MiniLED backlight module 20, which includes a reflective film 220, a micro-structured diffusion film 240, and a reflector 160.

The light reflecting film 220 includes at least one reflecting unit layer 221. The reflective unit layer 221 includes a high refractive layer 222 and a low refractive layer 224 which are stacked. The high refractive layer 222 has a refractive index greater than that of the low refractive layer 224.

The microstructured diffusion film 240 is laminated to the light exit side 228 of the light reflecting film 220.

The backlight panel 101 includes a circuit substrate 120 and a plurality of MiniLED chips 140. The MiniLED chips 140 are arranged on the circuit substrate 120 at intervals. The plurality of MiniLED chips 140 are disposed opposite to and spaced apart from the reflective film 220.

The reflective sheet 160 is disposed on the side of the circuit substrate 120 facing the reflective film 220, so as to avoid the MiniLED chips 140. The reflective sheet 160 is disposed opposite to and spaced apart from the light-reflecting film 220 to form the light-mixing region 130.

It is understood that, in the embodiment of the present application, a plurality of MiniLED chips 140 are used for emitting light; the reflection unit layer 221 has high reflectivity to small-angle light and low reflectivity to large-angle light, so that the reflection unit layer 221 reflects the small-angle light, allows the large-angle light to transmit, and is used for filtering the small-angle light, thereby reducing the central bright spot of the lamp top, improving the far brightness, and further expanding the size of the light spot; the light reflected by the reflection unit layer 221 is reflected by the reflection sheet 160 and then enters the reflection unit layer 221 again, and the reflection unit layer 221 filters small-angle light again; the large-angle light of the transmission and reflection unit layer 221 enters the microstructure diffusion film 240, and the microstructure diffusion film 240 diffuses light spots formed by the large-angle light; thereby ensuring the uniformity of light exiting the microstructured diffuser film 240. Therefore, the MiniLED backlight module 20 provided in the embodiment of the present application reflects light through the reflective sheet 160, filters small-angle light through the reflective unit layer 221, and diffuses light through the microstructure diffusion film 240, so as to ensure the uniform light property of light emitted from the microstructure diffusion film 240.

It can be understood that, in the embodiment of the present application, the light mixing distance, that is, the distance between the reflection sheet 160 and the reflective film 220 is reduced, so that the distance between the reflection sheet 160 and the reflective unit layer 221 is reduced. Through the combined action of the reflection sheet 160 reflecting light rays, the reflection unit layer 221 filtering small-angle light rays and the microstructure diffusion film 240 diffusing light rays, light spots formed by each MiniLED chip 140 are enlarged, and therefore the light mixing distance can be reduced on the premise that the uniformity of the whole light formed by the plurality of MiniLED chips 140 is not reduced. Because the light spot formed by each MiniLED chip 140 is enlarged, the light mixing distance can be greatly reduced on the premise of not reducing the uniformity of the overall light formed by a plurality of MiniLED chips 140.

Therefore, in the MiniLED backlight module 20 and the backlight module using the diffusion plate provided in the embodiment of the present application, under the condition that the number of MiniLED chips 140 is the same and the arrangement pitch of the MiniLED chips is also the same, the light mixing distance of the MiniLED backlight module 20 is reduced compared with the light mixing distance of the backlight module using the diffusion plate, and thus the uniformity of the whole light formed by the MiniLED chips of the MiniLED backlight module 20 is not reduced. Therefore, the light mixing distance is reduced by reflecting the light by the reflector sheet 160, filtering the small-angle light by the reflecting unit layer 221 and diffusing the light by the microstructure diffusion film 240, so that the thickness of the backlight module and the thickness of the whole display device 2 are reduced while the light uniformity of the light emitted from the microstructure diffusion film 240 is ensured. Meanwhile, the MiniLED backlight module 20 provided in the embodiment of the present application realizes a flexible structure of a full film without a diffusion plate, and the MiniLED backlight module 20 is matched with a flexible circuit board, a flexible backplane and a flexible glass liquid crystal display, so that a full flexible LCD television can be realized.

It can be further understood that in the embodiment of the present application, the light emitted from the multiple MiniLED chips 140 is homogenized by the stacked reflective film 220 and the microstructure diffusion film 240. The light-homogenizing capability of the light reflecting film 220 and the microstructure diffusing film 240 which are arranged in a stacked manner reaches the light-homogenizing capability of the diffusion plate. While the overall thickness and overall weight of the laminated light reflecting film 220 and microstructured diffusing film 240 is less than the thickness and weight of the diffusing film. Therefore, the light emitted by the MiniLED chips 140 is homogenized by the stacked reflective film 220 and the microstructure diffusion film 240 instead of a diffusion plate, and the thickness and weight of the backlight module and the whole device can be reduced.

Therefore, the light mixing distance is reduced by reflecting the light by the reflector sheet 160, filtering the small-angle light by the reflecting unit layer 221 and diffusing the light by the microstructure diffusion film 240, so that the thickness of the whole backlight module and the thickness of the display device 2 are reduced while the light uniformity of the light emitted from the microstructure diffusion film 240 is ensured. It can be understood that, when the reflective film 220 includes a plurality of reflective unit layers 221 sequentially arranged along the light incidence direction, the reflectivity of the reflective film 220 to the light incident at the zero angle is closer to 100% as more reflective processes are performed on the light incident at the zero angle, that is, the light incident perpendicular to the reflective unit layers 221.

It is understood that, referring to fig. 2 and 3, the light reflecting film 220 includes at least one high refractive layer 222 and at least one low refractive layer 224. The total number of the at least one high refractive layer 222 is the same as the total number of the at least one low refractive layer 224; the high refractive layers 222 and the low refractive layers 224 are alternately stacked to form at least one reflective unit layer 221. The light incident side 226 of the reflective film 220 is the high refractive layer 222, and the light emergent side 228 of the reflective film 220 is the low refractive layer 224.

In some embodiments, referring to fig. 2, the reflective film 220 may include a high refractive layer 222 and a low refractive layer 224, and the high refractive layer 222 and the low refractive layer 224 are stacked to form a reflective unit layer 221. The light-incident side 226 is the high refractive layer 222, and the light-emitting side 228 is the low refractive layer 224.

In other embodiments, referring to fig. 3, the reflective film 220 may further include two high refractive layers 222 and two low refractive layers 224, and the high refractive layers 222 and the low refractive layers 224 are alternately stacked to form two reflective unit layers 221. The light-incident side 226 is the high refractive layer 222, and the light-emitting side 228 is the low refractive layer 224.

It is understood that when the reflective film 220 has the structure shown in fig. 2 or fig. 3, that is, the reflective film 220 has the structure in which the light-incident side 226 is the high refractive layer 222 and the light-emitting side 228 is the low refractive layer 224, the light-incident side 226 and the light-emitting side 228 of the reflective film 220 cannot be mixed, and the application of the reflective film 220 has directionality.

It is understood that, referring to fig. 4 and 5, the light reflecting film 220 includes at least two high refractive layers 222 and at least one low refractive layer 224. The total number of the at least two high refractive layers 222 is one more than the total number of the at least one low refractive layer 224, and the high refractive layers 222 and the low refractive layers 224 are alternately stacked to form at least one reflective unit layer 221. The light incident side 226 and the light emitting side 228 of the reflective film 220 are both high refractive layers 222.

In some embodiments, referring to fig. 4, the light-reflecting film 220 may include two high refractive layers 222 and one low refractive layer 224, and the high refractive layers 222 and the low refractive layers 224 are alternately stacked to form a reflective unit layer 221. The light-incident side 226 is the high refractive layer 222, and the light-emitting side 228 is also the high refractive layer 222.

In other embodiments, referring to fig. 5, the reflective film 220 may further include three high refractive layers 222 and two low refractive layers 224. The high refractive layers 222 and the low refractive layers 224 are alternately stacked to form two reflective unit layers 221. The light-incident side 226 is the high refractive layer 222, and the light-emitting side 228 is also the high refractive layer 222.

It is understood that when the reflective film 220 has the structure shown in fig. 4 or fig. 5, that is, the reflective film 220 has the structure of the high refractive layer 222 on both the light incident side 226 and the light emergent side 228, the reflective film 220 is non-directional. That is, the two high refractive layers 222 located at the outermost layers of the reflective film 220 can be both used as the light incident side 226 and the light emergent side 228. When one of the two high refractive layers 222 at the outermost layer of the reflective film 220 serves as the light incident side 226, the other high refractive layer 222 serves as the light emergent side 228.

It is understood that the thickness of the high refractive layer 222 is (1 + 2k) × λ/4, where λ is the wavelength of the light wave in the high refractive layer 222 and k is an integer greater than or equal to zero. Illustratively, when the k value is 0,1,2 in turn, the thickness of the high refractive layer 222 is λ/4,3 λ/4,5 λ/4, respectively.

It can be understood that the thickness of the high refractive layer 222 can be designed by changing the k value, and then a relationship graph of the incident angle of the light incident on the reflective film 220 from the air and the reflectivity of the reflective film 220 to the light can be obtained through simulation software. And determining the k value when the minimum value point of the reflectivity is close to 90 degrees according to the relational graph. The closer the minimum point of the reflectivity is to 90 °, the greater the diffusion effect of the reflective film 220 on the light spot.

In some embodiments, each high refractive layer 222 of the at least two high refractive layers 222 has the same thickness; each of the low refractive layers 224 of the at least one low refractive layer 224 has the same thickness.

It can be understood that the material of the high refractive layer 222 can also be designed by changing the refractive index of the material, and then the relationship between the incident angle of the light incident on the reflective film 220 from the air and the reflectivity of the reflective film 220 to the light can be obtained by simulation software. From this relationship, the material of the high refractive layer 222 is determined when the minimum point of the reflectance is close to 90 °. The closer the minimum point of the reflectivity is to 90 °, the greater the diffusion effect of the reflective film 220 on the light spot.

It can be understood that, referring to fig. 6, the edge of the reflective sheet 160 is spaced from the edge of the MiniLED; an area between the edge of the reflective sheet 160 of the circuit substrate 120 and the edge of the MiniLED is defined as an open area.

The MiniLED backlight module 20 further includes at least one white ink layer 180; at least one white ink layer 180 is disposed in the opening region.

It will be appreciated that the open areas are provided primarily to allow the reflector sheet 160 to remain flat after thermal expansion and contraction. Illustratively, the MiniLED backlight assembly 20 may include a white ink layer. When the open region is coated with a white ink layer, the white ink layer may have a reflectance of 87% to light. For example, the MiniLED backlight assembly 20 may include two white ink layers. When the open area is coated with two white ink layers, the reflectivity of the two white ink layers to light can reach 94.5%, which is close to the reflectivity of 95% of the silver reflective film.

It can be understood that when the white ink layer 180 is not provided in the open region, the open region has a low reflectance and a high absorbance, and light energy is lost by being absorbed by the open region. The white ink layer 180 has high reflectance properties. After the white ink layer 180 is disposed in the opening region, the white ink layer 180 and the reflective sheet 160 cover all regions of the circuit substrate 120 except the MiniLED chip 140. The white ink layer 180 and the reflector plate 160 reflect the incident light together, so that the light energy loss is reduced, and the utilization rate of the light energy emitted by the MiniLED chip 140 is improved.

It is understood that referring to fig. 6, the microstructured diffusion film 240 includes a base film 242 and a first microstructure layer 246; the first microstructure layer 246 is disposed on a side of the microstructure diffusion film 240 facing the reflective film 220; first micro-structure layer 246 includes a plurality of micro-prisms arranged in an array or a plurality of micro-pyramids arranged in an array.

It is understood that referring to fig. 7-9, microstructured diffusion film 240 includes base film 242, first microstructure layer 246, and second microstructure layer 248; the first microstructure layer 246 is disposed on the side of the microstructure diffusion film 240 facing the reflective film 220; the second microstructure layer 248 is disposed on a side of the microstructure diffusion film 240 opposite to the reflective film 220; first micro-structure layer 246 includes a plurality of micro-prisms arranged in an array along a first direction; the second micro-structure layer 248 comprises a plurality of micro-prisms arranged in an array along the second direction; the first direction and the second direction are perpendicular to each other.

Illustratively, the micro pyramids may be regular rectangular pyramids.

Illustratively, the first microstructure layer 246 includes a plurality of micro prisms arranged in an array along a first direction; when the second microstructure layer 248 includes a plurality of microprisms arranged in an array along the second direction, the distance between the first microstructure layer 246 and the second microstructure layer 248 may be 0.03mm to 0.15mm, and the vertex angle of the microprisms in the first microstructure layer 246 and the second microstructure layer 248 may be 80 ° to 100 °.

It is understood that, referring to fig. 10, a plurality of MiniLED chips 140 are used to emit blue light; the MiniLED backlight module 20 further includes a color conversion layer 260, wherein the color conversion layer 260 is stacked on the light-emitting side 228 of the micro-structured diffusion film 240, and is used for converting the incident blue backlight into a white backlight.

It is understood that the color conversion layer 260 may be a quantum dot film or a fluorescent film.

It is understood that the quantum dot film is used to convert an incident blue backlight into a white backlight. Scattering particles, green quantum dots and red quantum dots are dispersed in the quantum dot film. Under the blue backlight, the scattering particles scatter the incident blue backlight, so that the green quantum dots and the red quantum dots are more fully excited to excite green light and red light with specific wave bands. The excited green light and red light with specific wave bands are mixed with the transmitted blue light to form white light. The quantum dot liquid crystal display device 2 using the blue backlight has a wide color gamut compared to the liquid crystal display device 2 directly using the white backlight.

It is understood that the phosphor film may be a YAG phosphor film or a KSF phosphor film.

The YAG phosphor film is used to convert an incident blue backlight into a white backlight. YAG fluorescent powder is dispersed in the YAG fluorescent film. When excited by blue light, YAG phosphor powder generates white light.

It is understood that the KSF phosphor film is used to convert an incident blue backlight into a white backlight. The KSF fluorescent powder is dispersed in the KSF fluorescent film. The KSF phosphor produces white light when excited by blue light.

It can be understood that, referring to fig. 11, the miniled backlight module 20 further includes a brightness enhancement film 280, and the brightness enhancement film 280 is disposed on a side of the color conversion layer 260 facing away from the reflective film 220.

It is understood that the brightness enhancement film 280 is used to improve the forward brightness of the MiniLED backlight 20. The brightness enhancement film 280 is a COPP film, a COP film, a POP film, a DOP film or a PF film.

In some embodiments, referring to fig. 10-11, the MiniLED chip 140 is covered with a layer of adhesive 170 to protect the MiniLED chip 140.

In some embodiments, referring to fig. 10-11, a support column 110 is disposed between the reflective film 220 and the reflective sheet 160 for forming a stable light mixing region 130.

Referring to fig. 12-14, a display device 2 according to an embodiment of the present disclosure includes a MiniLED backlight module 20 and a liquid crystal panel 40.

The MiniLED backlight module and the display device provided in the embodiments of the present application are described in detail above, and specific examples are applied in the description to explain the principle and the embodiments of the present application, and the description of the embodiments above is only used to help understand the method and the core idea of the present application; meanwhile, for those skilled in the art, according to the idea of the present application, the specific implementation manner and the application scope may be changed, and in summary, the content of the present specification should not be construed as a limitation to the present application.

Claims

1. The MiniLED backlight module is characterized by comprising:

the reflective film comprises at least one layer of reflective unit layer, wherein the reflective unit layer comprises a high-refractive layer and a low-refractive layer which are arranged in a stacked manner, and the refractive index of the high-refractive layer is greater than that of the low-refractive layer;

the microstructure diffusion film is laminated on the light emergent side of the reflective film;

the backlight lamp panel comprises a circuit substrate and a plurality of MiniLED chips; the MiniLED chips are arranged on the circuit substrate at intervals; the MiniLED chips are opposite to the reflective film and are arranged at intervals; and

the reflector plate is arranged on one side, facing the reflective film, of the circuit substrate in a mode of avoiding the MiniLED chips; the reflecting sheet is opposite to the reflecting film and arranged at intervals to form a light mixing area.

2. The MiniLED backlight module of claim 1, wherein the reflective film comprises at least one high refractive layer and at least one low refractive layer; the total number of the at least one high-refraction layer is the same as that of the at least one low-refraction layer, and the high-refraction layers and the low-refraction layers are alternately stacked to form at least one reflection unit layer; the light incident side of the reflective film is the high refraction layer; the light-emitting side of the reflective film is the low refraction layer.

3. The MiniLED backlight module of claim 1, wherein the reflective film comprises at least two high refractive layers and at least one low refractive layer; the total number of the at least two high-refraction layers is one more than that of the at least one low-refraction layer, and the high-refraction layers and the low-refraction layers are alternately stacked to form at least one reflection unit layer; the light incident side and the light emergent side of the reflective film are both the high-refraction layer.

4. The MiniLED backlight module of any one of claims 2-3, wherein the thickness of the high refractive layer is (1 + 2k) × λ/4, where λ is the wavelength of the light in the high refractive layer and k is an integer greater than or equal to zero.

5. The MiniLED backlight module of claim 1, wherein the edge of the reflector plate is spaced from the edge of the MiniLED; defining an area between an edge of the reflector sheet and an edge of the MiniLED of the circuit substrate as an opening area; the MiniLED backlight module also comprises at least one white ink layer; the at least one white ink layer is disposed in the opening region.

6. The MiniLED backlight module of any of claims 2-3 or 5, wherein the microstructured diffuser film comprises a base film and a first microstructured layer; the first microstructure layer is arranged on one side, facing the reflective film, of the microstructure diffusion film; the first microstructure layer comprises a plurality of microprisms arranged in an array or a plurality of micro pyramids arranged in an array; or alternatively

The microstructure diffusion film comprises a base film, a first microstructure layer and a second microstructure layer; the first microstructure layer is arranged on one side, facing the reflective film, of the microstructure diffusion film; the second microstructure layer is arranged on one side, back to the reflective film, of the microstructure diffusion film; the first microstructure layer comprises a plurality of microprisms arrayed along a first direction; the second microstructure layer comprises a plurality of microprisms arrayed along a second direction; the first direction and the second direction are perpendicular to each other.

7. The MiniLED backlight module of any of claims 2-3 or 5, wherein the MiniLED chips are configured to emit blue light; the MiniLED backlight module further comprises a color conversion layer, wherein the color conversion layer is arranged on the light emitting side of the microstructure diffusion film in a laminated mode and is used for converting incident blue backlight into white backlight.

8. The MiniLED backlight module of claim 7, wherein the color conversion layer is a quantum dot film or a fluorescent film.

9. The MiniLED backlight module of claim 7, further comprising a brightness enhancement film disposed on a side of the color conversion layer opposite to the reflective film.

10. A display device, comprising:

the MiniLED backlight module of any one of claims 1 to 9; and

a liquid crystal panel;

and the brightness enhancement layer of the MiniLED backlight module faces the liquid crystal panel.