Quantum dot composite film and backlight module comprising same

Abstract

The utility model provides a quantum dot composite film and a backlight module comprising the same. The quantum dot composite film comprises a micro-lens diffusion film layer, a first barrier film layer, a quantum dot resin film layer, a second barrier film layer and a selective permeable film layer which are sequentially arranged, the thickness of the micro-lens diffusion film layer is 25-125 microns, and the thicknesses of the first barrier film layer and the second barrier film layer are both smaller than or equal to 30 microns. The selective permeable membrane layer is of a multi-membrane-layer composite structure, and light below 480 nm can selectively penetrate through the selective permeable membrane layer. The quantum dot composite film is simple in structure, the micro lens diffusion film layer has the functions of diffusion and brightness improvement, the selective transmission film layer improves the utilization rate of red and green light emitted by quantum dots excited by the blue LED light source, and the lighting effect of the quantum dot composite film is improved. Due to the design of the thin barrier film layer and the design of the whole composite film, the thinning of the composite film is also realized at the same time.

Description

Technical Field

[0001] The utility model relates to the technical field of quantum dot membranes, in particular to a quantum dot composite film and a backlight module containing the same. Background Art

[0002] Quantum dot films with high color gamut are widely used in liquid crystal display devices. In order to reduce costs, quantum dot composite films have become a new trend. However, due to the large variety of optical films in the backlight module, the thickness of the quantum dot composite film increases, and how to improve the luminous efficiency of the composite film is also a new problem. Summary of the invention

[0003] The utility model aims to provide a quantum dot composite film and a backlight module containing the same, which solves the problem of how to prepare a thin quantum dot composite film with high light extraction efficiency.

[0004] According to the first aspect of the present disclosure, a quantum dot composite film is provided, comprising a microlens diffusion film layer, a first barrier film layer, a quantum dot resin film layer, a second barrier film layer and a selectively transparent film layer arranged in sequence, the thickness of the microlens diffusion film layer is 25-125 microns, the thickness of the first barrier film layer and the second barrier film layer are both less than or equal to 30 microns, the selectively transparent film layer is a multi-film layer composite structure, and the selectively transparent film layer can selectively transmit light at 480nm.

[0005] According to another aspect of the present disclosure, a backlight module is provided, comprising a plurality of blue LED light sources, and also comprising any of the above-mentioned quantum dot composite films located directly above any of the above-mentioned blue LED light sources, and a microlens diffusion film layer is arranged away from the blue LED light sources; or also comprising a light guide plate located on the side of the plurality of blue LED light sources, and also comprising any of the above-mentioned quantum dot composite films located on the light guide plate, and light after light conversion by the quantum dot composite film is emitted after passing through the microlens diffusion film layer.

[0006] The quantum dot composite film structure of the technical solution of the present application is simple. The above-mentioned microlens diffusion film layer has the function of diffusion and improving brightness. The above-mentioned selective transmission film improves the utilization rate of the red and green light emitted by the blue LED light source to excite the quantum dots, and improves the light efficiency of the quantum dot composite film. The selective transmission film layer is compounded with the second barrier film layer, which can not only play the function of selective transmission to improve brightness, but also play the function of supporting the second barrier film layer; similarly, the microlens diffusion film layer is compounded with the first barrier film layer, and while playing a supporting role, the typical microlens structure can also improve light extraction, achieving high color gamut while also achieving high brightness. Due to the design of the thin barrier film layer and the design of the overall composite film, the thinness of the composite film is also achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The drawings constituting part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention. In the drawings:

[0008] Figure 1 A schematic structural diagram of a quantum dot composite film embodiment of the present application is shown.

[0009] Figure 2 A schematic structural diagram of another quantum dot composite film embodiment of the present application is shown.

[0010] Figure 3 A structural schematic diagram of a backlight module embodiment of the present application is shown.

[0011] Figure 4 A structural schematic diagram of another backlight module embodiment of the present application is shown.

[0012] 100, microlens diffusion film layer; 201, first barrier film layer; 300, quantum dot resin film layer; 301, quantum dots; 202, second barrier film layer; 400, selective transmission film layer; 500, blue LED light source; 600, light guide plate.

[0013] For ease of understanding, the position, size, range, etc. of each structure shown in the drawings and the like may not represent the actual position, size, range, etc. Therefore, the present disclosure is not limited to the position, size, range, etc. disclosed in the drawings and the like. DETAILED DESCRIPTION

[0014] In the description of this application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features.

[0015] It should be noted that the following detailed descriptions are illustrative and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0016] See also Figure 1In the first aspect, the utility model provides a quantum dot composite film, comprising a microlens diffusion film layer 100, a first barrier film layer 201, a quantum dot resin film layer 300, a second barrier film layer 202 and a selective transmission film layer 400 arranged in sequence, the thickness of the microlens diffusion film layer 100 is 25-125 microns, the thickness of the first barrier film layer 201 and the second barrier film layer 202 are both less than or equal to 30 microns, the selective transmission film layer 400 is a multi-film layer composite structure, and the selective transmission film layer 400 can selectively transmit light at 480nm. The above-mentioned film layers are all arranged in contact with each other.

[0017] The composite film structure of this scheme is simple. The above-mentioned microlens diffusion film layer 100 has the function of diffusion and improving brightness. The above-mentioned selective transmission film improves the utilization rate of the red and green light emitted by the blue LED light source to excite the quantum dots 301, and improves the light efficiency of the quantum dot composite film. The selective transmission film layer 400 is compounded with the second barrier film layer 202, which can not only play the function of selective transmission to improve brightness, but also play the function of supporting the second barrier film layer 202; similarly, the microlens diffusion film layer 100 is compounded with the first barrier film layer 201. While playing a supporting role, the typical microlens structure can also improve light extraction, achieving high color gamut and high brightness. Due to the design of the thin barrier film layer and the design of the overall composite film, the thinness of the composite film is also achieved.

[0018] The microlens diffusion film layer 100 can be prepared by mold rolling.

[0019] In some embodiments, the transmittance of the selective transmission film layer 400 to light at 480 nm is greater than or equal to 80%, and the transmittance to light above 500 nm is less than or equal to 50%. In some embodiments, the transmittance of the selective transmission film layer 400 to light at 480 nm is greater than or equal to 90%, and the transmittance to light above 500 nm is less than or equal to 40%.

[0020] In some embodiments, the quantum dot resin film layer 300 includes red quantum dots and green quantum dots, and also includes at least one of acrylic resin, epoxy resin or silicone resin. In some embodiments, the quantum dot resin film layer 300 includes a red quantum dot layer and a green quantum dot layer.

[0021] In some embodiments, the thickness of the first barrier film layer 201 and the second barrier film layer 202 are both less than or equal to 23 micrometers, and the thickness of the selective permeable film layer 400 is 50-100 micrometers.

[0022] like Figure 2 As shown, in some embodiments, the microlens diffusion film layer 100 has an array of hemispherical patterns 102 and also has a diffusion film layer 101 .

[0023] In some embodiments, the microlens diffusion film layer 100 has scattering particles to provide a diffusion effect. The scattering particles can be inorganic oxide particles or organic polymer particles. In some embodiments, the scattering particles are located in the diffusion layer 101.

[0024] In some embodiments, the first barrier film layer 201 and the second barrier film layer 202 are independently PET (polyethylene terephthalate) layers or PEN (polyethylene naphthalate) layers with oxide layers on the surface. The oxide layers face the quantum dot resin film layer. The oxide layers are silicon oxide, aluminum oxide, etc.

[0025] In some embodiments, the selective transmission film layer 400 includes a scratch-resistant layer, a substrate layer, a primer layer, and a functional layer, wherein the functional layer includes a cholesteric liquid crystal coating. The functional layer is closer to the quantum dot resin film layer. The design of the scratch-resistant layer reduces the probability of scratching the selective transmission film layer 400.

[0026] The second aspect of the utility model provides a backlight module, comprising a plurality of blue LED light sources 500, and also comprising any of the above-mentioned quantum dot composite films located directly above the plurality of blue LED light sources 500, and the microlens diffusion film layer 100 is arranged away from the blue LED light sources, such as Figure 3 or the backlight module further includes a light guide plate 600 located on the side of the plurality of blue LED light sources 500, and further includes any one of the above-mentioned quantum dot composite films located on the light guide plate 600, such as Figure 4 As shown, the light after the light conversion of the quantum dot composite film passes through the microlens diffusion film layer 100 and then is emitted. The use of the above-mentioned quantum dot composite film realizes the lightness and thinness of the backlight module. It can be understood that the blue light emitted by the blue LED light source passes through the selective transmission film layer 400, and then passes through the quantum dot resin film layer 300 for light conversion. The light with a longer wavelength (red light or green light) in the converted light is difficult to be emitted from the selective transmission film layer. The unconverted blue light can again excite the quantum dots 301 in the quantum dot resin film layer 300 to produce long-wave light. The converted light and blue light are finally emitted from the microlens diffusion film layer 100 to form white light. The above-mentioned backlight module is used in a liquid crystal display device. The presence of the selective transmission film layer reduces the probability of red and green light leaking from the bottom (in the opposite direction of the light output direction), improves the utilization rate of blue light, and enhances the efficiency of color conversion. Combined with the microlens diffusion film layer on the top, the backlight module with the quantum dot composite film has the advantages of low energy consumption, high brightness, high uniformity, and high contrast. In some embodiments, the liquid crystal display device is a mobile phone.

[0027] In some embodiments, the backlight module has a fluorescence emission spectrum under working conditions, and the fluorescence emission spectrum includes three peaks of red light, green light and blue light, and the height (or luminous intensity) difference between any two of the three peaks is within ±30%. Due to the structural design of the selective transmission membrane layer, the luminous intensity of the three bands can be balanced. Preferably, the height difference between any two of the three peaks is within 10%.

[0028] The above description is only the preferred embodiment of the utility model, and is not intended to limit the utility model. For those skilled in the art, the utility model can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.

Claims

1. A quantum dot composite film, characterized in that: It includes a microlens diffusion film layer, a first barrier film layer, a quantum dot resin film layer, a second barrier film layer and a selective transmission film layer which are arranged in sequence. The thickness of the microlens diffusion film layer is 25-125 microns. The thickness of the first barrier film layer and the second barrier film layer are both less than or equal to 30 microns. The selective transmission film layer is a multi-film layer composite structure, and the selective transmission film layer can selectively transmit light below 480nm.

2. The quantum dot composite film according to claim 1, characterized in that The transmittance of the selective transmission film layer to light at 480 nm is greater than or equal to 80%, and the transmittance to light above 500 nm is less than or equal to 50%.

3. The quantum dot composite film according to claim 1, characterized in that: The quantum dot resin film layer includes red quantum dots and green quantum dots, and also includes at least one of acrylic resin, epoxy resin or silicone resin.

4. The quantum dot composite film according to claim 1, characterized in that: The thickness of the first barrier film layer and the second barrier film layer are both less than or equal to 23 micrometers, and the thickness of the selective permeable film layer is 50-100 micrometers.

5. The quantum dot composite film according to claim 1, characterized in that: The microlens diffusion film layer has an array of hemispherical patterns.

6. The quantum dot composite film according to claim 1, characterized in that: The microlens diffusion film layer has scattering particles.

7. The quantum dot composite film according to claim 1, characterized in that: The first barrier film layer and the second barrier film layer are independently a PET layer or a PEN layer having an oxide layer on the surface.

8. The quantum dot composite film according to claim 1, characterized in that: The selective transmission film layer comprises a scratch-resistant layer, a substrate layer, a primer layer and a functional layer, and the functional layer comprises a cholesteric liquid crystal coating.

9. A backlight module, comprising a plurality of blue LED light sources, characterized in that: It also includes the quantum dot composite film according to any one of claims 1-7 located directly above the multiple blue LED light sources, and the microlens diffusion film layer is arranged away from the blue LED light sources; or it also includes a light guide plate located on the side of the multiple blue LED light sources, and also includes the quantum dot composite film according to any one of claims 1-7 located on the light guide plate, and the light after light conversion by the quantum dot composite film passes through the microlens diffusion film layer and then is emitted.

10. The backlight module according to claim 9, characterized in that: The backlight module has a fluorescence emission spectrum under working conditions, and the fluorescence emission spectrum includes three peaks of red light, green light and blue light, and the height difference between any two of the three peaks is within ±30%.

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