Optical film, backlight module and display device
By setting diffusing particles in the hollow diffusion structure of the optical diaphragm to improve haze and maintain light transmittance, the problem of haze and light transmittance imbalance in the existing optical diaphragm is solved, and more efficient energy use and longer lamp bead life is achieved.
Patent Information
- Application Number
- CN202510484099.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-16
- Publication Date
- 2025-06-10
AI Technical Summary
The existing optical diaphragm has insufficient balance treatment on haze and light transmittance, resulting in low light transmittance when a certain haze is reached, which in turn requires a large backlight power, which increases energy consumption and affects the service life of the lamp beads.
An optical diaphragm is designed to provide diffused particles in the hollow diffusion structure of the base film layer, and the haze of the diaphragm is improved by scattering effect of the diffusion particles, and light absorption is reduced through the hollow structure, thereby maintaining a high light transmittance.
While ensuring the haze of the optical diaphragm, it maintains a high light transmittance, solves the problem of haze and light transmittance imbalance, reduces the backlight power requirement, reduces energy consumption and extends the service life of the lamp beads.
Smart Images
Figure CN120122364A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of optical technologies, and particularly to an optical film, a backlight module, and a display device. Background Art
[0002] In a backlight display system, the divergence angle of the light emitted by a single point light source is limited, resulting in a phenomenon that the energy in the central region of the light-emitting surface is greater than that in the surrounding regions. Conventional technologies usually cover a film and a diffusion plate or a light guide plate with diffusion and brightness enhancement functions above the light-emitting surface of the light source to achieve light diffusion and light mixing, thereby realizing uniform light emission from the light-emitting surface.
[0003] In addition, the market's light homogenizing films do not handle the balance between haze and transmittance well. It is impossible to ensure good transmittance when reaching a certain haze. If the transmittance is not high, a larger backlight power is required, which not only consumes a large amount of energy but also affects the service life of the lamp beads. Therefore, the application of the light homogenizing film in the backlight display system is of great significance for improving the display effect and energy efficiency.
[0004] Therefore, the current technology still needs to be improved. Summary of the Invention
[0005] This application provides an optical film, a backlight module, and a display device, which can alleviate the problem of the imbalance between haze and transmittance existing in the current optical film.
[0006] This application provides an optical film, which includes a base film layer. A plurality of diffusion structures are arranged in the base film layer. The diffusion structures are hollow structures and diffusion particles are arranged in the diffusion structures.
[0007] In the optical film of some embodiments, the diffusion structure is an ellipsoidal structure.
[0008] In the optical film of some embodiments, the diameter of at least part of the diffusion structures is less than 800 um.
[0009] In the optical film of some embodiments, the diffusion particles are spherical structures.
[0010] In the optical film of some embodiments, the diameter of at least part of the spherical structures is d, where 2 um ≤ d ≤ 50 um.
[0011] In the optical film of some embodiments, the diffusion particles are hollow structures.
[0012] In the optical film of some embodiments, the diffusion particles are glass balls.
[0013] In the optical film of some embodiments, the inner wall thickness of at least part of the diffusion particles is w, where 1 um ≤ w ≤ 3 um.
[0014] In some embodiments of the optical film, the optical film further includes a first microstructure layer and a second microstructure layer, and the base film layer is located between the first microstructure layer and the second microstructure layer.
[0015] In some embodiments of the optical film, the microstructures in the first microstructure layer include pyramid structures, and the apex angles of at least some of the pyramid structures are a, where 80° < a ≤ 100°.
[0016] In some embodiments of the optical film, the microstructures in the second microstructure layer include pyramid structures, and the apex angles of at least some of the pyramid structures are b, where 40° ≤ b ≤ 80°.
[0017] In some embodiments of the optical film, the apex angles of at least some of the pyramid structures are h, where 20 μm ≤ h ≤ 50 μm.
[0018] In some embodiments of the optical film, a refractive layer is disposed on the surfaces of both the first microstructure layer and the second microstructure layer, and the refractive index of the refractive layer is n, where 1.0 ≤ n ≤ 2.4.
[0019] In some embodiments of the optical film, the thickness of the refractive layer is c, where 0.1 μm ≤ c ≤ 10 μm.
[0020] In an embodiment of the present application, a backlight module is further provided, and the backlight module includes the above-mentioned optical film.
[0021] In an embodiment of the present application, a display device is further provided, and the display device includes the above-mentioned backlight module.
[0022] An optical film, a backlight module, and a display device provided by the present application, wherein, in the optical film, diffusion particles are disposed in the diffusion structure of the base film layer, and the scattering of light by the diffusion particles helps to increase the haze of the film and make the light distribution more uniform. Since the diffusion structure is a hollow structure, it can reduce the absorption of light by the diffusion structure, so that the light transmittance is maintained while increasing the haze. Therefore, by providing a hollow diffusion structure and diffusion particles in the optical film, the present application can maintain the light transmittance while ensuring the haze of the optical film, so as to alleviate the problem of imbalance between haze and light transmittance existing in current optical films. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] The following, in conjunction with the drawings, through a detailed description of the specific embodiments of the present application, will make the technical solutions and other beneficial effects of the present application obvious.
[0024] Figure 1 FIG. 1 is a schematic diagram of the first structure of the optical film provided by an embodiment of the present application.
[0025] Figure 2Provided by the embodiments of the present application Figure 1 Schematic diagram of the size of the diffusion structure and diffusion particles in
[0026] Figure 3 Schematic diagram of the second structure of the optical film provided by the embodiments of the present application
[0027] Figure 4 Provided by the embodiments of the present application Figure 3 Schematic diagram of the size of the first microstructure layer and the second microstructure in
[0028] Figure 5 Schematic diagram of the third structure of the optical film provided by the embodiments of the present application
[0029] Figure 6 Schematic diagram of the optical path before and after laying the refraction layer in the optical film provided by the embodiments of the present application
[0030] Reference numerals:
[0031] 11. Base film layer; 12. First microstructure layer; 13. Second microstructure layer; 14. Refraction layer;
[0032] 111. Diffusion structure; 112. Diffusion particles. Detailed implementation manners
[0033] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present application.
[0034] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more features. In the description of the present invention, "a plurality" means two or more unless otherwise specifically defined.
[0035] Please refer to Figure 1, this embodiment provides an optical film. The optical film includes a base film layer 11, in which a plurality of diffusion structures 111 are provided. The diffusion structures 111 are hollow structures, and diffusion particles 112 are provided in the diffusion structures 111. In this embodiment, by providing diffusion particles 112 in the diffusion structures of the base film layer 11, the diffusion of light by the diffusion particles 112 helps to increase the haze of the film and make the light distribution more uniform. Since the diffusion structures 111 are hollow structures, the absorption of light by the diffusion structures 111 can be reduced, so that the light transmittance can be maintained while increasing the haze. Therefore, in this application, by providing hollow diffusion structures 111 in the optical film and providing diffusion particles 112, the light transmittance can be maintained while ensuring the haze of the optical film, so as to alleviate the problem of imbalance between haze and light transmittance existing in current optical films.
[0036] In some embodiments, the diffusion structure 111 in this embodiment is an ellipsoidal structure, that is, the diffusion structure 111 with a hollow structure is ellipsoidal. By providing diffusion particles 112 in the ellipsoidal diffusion structure 111, the haze of the film is increased by the scattering of the diffusion particles 112. The diffusion particles 112 are located in the hollow structure, and the setting of the hollow structure can reduce the absorption of light and is beneficial to improving the light transmittance.
[0037] Please refer to Figure 2 , in some embodiments, the diameter of at least part of the ellipsoidal diffusion structure is less than 800 um. For example, if the ellipsoidal diffusion structure 111 extends along the horizontal direction, the maximum size of the diffusion structure 111 in the horizontal direction is less than 800 um, such as the maximum diameter of the diffusion structure 111 is 750 um or 700 um, etc. In this embodiment, the diffusion structure 111 is set to a certain size to ensure that there is a certain gap around the diffusion particles 112, which is beneficial to reducing the absorption of light and ensuring the light transmittance of the optical film.
[0038] In some embodiments, the diffusion particles 112 can be solid spherical structures. Correspondingly, the diameter of at least part of the spherical structure is d, then 2 um ≤ d ≤ 50 um. For example, the diameter of the diffusion particles 112 is from 2 um to 20 um. In this embodiment, by providing spherical diffusion particles 112 in the diffusion structure 111, the light can be focused within a certain exit angle, thereby enhancing the brightness of the exit light. The surface curvature of the spherical diffusion particles 112 is relatively uniform, which can effectively scatter light and prevent it from directly emitting from the base film layer 11, thus achieving a better atomization effect and increasing the haze of the optical film. At the same time, the spherical diffusion particles 112 have good symmetry, and the light is not easily affected by the irregularity of the particle shape, which is beneficial to improving the light emission uniformity. Of course, in other embodiments, diffusion particles 112 of other shapes can also be selected, and microstructures can also be provided on the surface of the diffusion particles 112, which is not limited in this application.
[0039] In another embodiment, the diffusing particles 112 can also be of a hollow structure. If the diffusing particles 112 are of a hollow spherical structure and the inner wall thickness of at least part of the diffusing particles is w, then 1 μm ≤ w ≤ 3 μm. Similarly, setting the diffusing particles 112 to a hollow structure can further reduce the absorption of light by the diffusing particles 112, ensuring that while the diffusing particles 112 scatter light to increase the haze, the light transmittance is guaranteed.
[0040] As an embodiment, the diffusing particles 112 can be glass beads, that is, the material of the diffusing particles 112 in this embodiment is glass. Preferably, it is a transparent glass material, which is beneficial to light transmission. However, in other embodiments, materials with the same function can also be selected to form the diffusing particles 112, and this application does not make any limitations in this regard.
[0041] As an embodiment, the base film layer 11 can be a PET (Polyethylene Terephthalate) base film. Of course, in other embodiments, base films with the same function can also be selected, and this application does not make any limitations in this regard.
[0042] Please refer to Figure 3 , in some embodiments, the optical film also includes a first microstructure layer 12 and a second microstructure layer 13, and the base film layer 11 is located between the first microstructure layer 12 and the second microstructure layer 13. The first microstructure layer 12 and the second microstructure layer 13 are respectively disposed on opposite sides of the base film layer 11. For example, if the first microstructure layer 12 is disposed on the light-incident side of the base film layer 11, then the second microstructure layer 13 is disposed on the light-emitting layer of the base film layer 11. In this embodiment, by providing the microstructure layer in the base film layer 11, it is beneficial to enhance the light scattering and uniformity of the optical film.
[0043] As an embodiment, the microstructures in the first microstructure layer 12 and the second microstructure layer 13 in this embodiment include pyramid structures. For example, octagonal pyramids, hexagonal pyramids or quadrangular pyramids are provided. In this embodiment, by providing the pyramid microstructures, it is beneficial to reduce the reflection loss of light and improve the light transmittance. The pyramid structure can effectively change the propagation direction of light, causing the light to refract and reflect multiple times when passing through the pyramid structure, thereby achieving a more uniform light distribution.
[0044] Please refer to Figure 4, as an embodiment, the apex angle of at least part of the pyramid structure is a, and the apex angle of at least part of the pyramid structure is b. Wherein, 80° < a ≤ 100°, for example, the apex angle of the pyramid structure of the first microstructure layer 12 is 90 degrees; wherein, 40° ≤ b ≤ 80°. That is, in this embodiment, the apex angle of the pyramids in one of the microstructure layers is larger, while the apex angle of the pyramids in the other microstructure layer is smaller. The smaller apex angle will cause the light to be reflected more frequently on the pyramid surface, thereby increasing the scattering angle of the light and making the light distribution more uniform. And the larger apex angle will cause the light to be reflected or refracted more concentratedly in a specific direction, thereby reducing the scattering angle and increasing the light intensity in a specific direction, which is beneficial to improving the brightness of the light.
[0045] As an embodiment, the height of at least part of the pyramid structures in the first microstructure layer 12 and the second microstructure layer 13 is h, where 20um ≤ h ≤ 50um, for example, the height of the pyramid structure is 30um. In this embodiment, in order to avoid light crosstalk, the height of the pyramid structure is controlled within a certain range: specifically, with a pyramid structure of a smaller height, the propagation path of the light inside the pyramid becomes shorter, and the scattering angle becomes larger, thus making the light more uniform; at the same time, with a pyramid structure of a smaller height, the number of reflections of the light inside the pyramid decreases, which is beneficial to improving the light transmittance.
[0046] Please refer to Figure 5 and Figure 6 , in some embodiments, a coating layer is laid on the surfaces of both the first microstructure layer 12 and the second microstructure layer 13 to form a refractive layer 14, and the refractive index of the refractive layer 14 is n, 1.0 ≤ n ≤ 2.4. The material of the refractive layer 14 can be titanium oxide, titanium sesquioxide, titanium pentoxide, titanium monoxide, zirconium dioxide, zinc sulfide, etc. In this embodiment, by setting a coating layer with a high refractive index, it is beneficial to increase the diffusion angle of the light.
[0047] As an embodiment, the thickness of the refractive layer 14 is c, where 0.1um ≤ c ≤ 10um, for example, if the thickness of the refractive layer 14 is 0.5um - 2um. In this embodiment, by setting the refractive layer 14, the light can be diffused in terms of optical refraction, which is beneficial to improving the light splitting effect of the optical film.
[0048] The embodiment of the present application also provides a backlight module, and this backlight module includes the above-mentioned optical film. Since the above optical film has been described in detail, it will not be elaborated here.
[0049] The embodiment of the present application also provides a display device, and this display device includes the above-mentioned backlight module. Among them, the display device can be a liquid crystal TV, and the corresponding backlight module can be a liquid crystal backlight module. The above-mentioned optical film is applied in this backlight module. Since the above optical film has been described in detail, it will not be elaborated here.
[0050] In the above embodiments, the descriptions of the respective embodiments have their own emphases. For the parts not elaborated in a certain embodiment, reference may be made to the relevant descriptions of other embodiments.
[0051] The optical film provided by the embodiments of the present application has been introduced in detail above. Specific examples are used herein to elaborate on the principle and implementation manner of the present application. The descriptions of the above embodiments are only used to help understand the technical solution and its core idea of the present application; those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.
Claims
1. An optical film, characterized in that: The optical film comprises a base film layer, wherein the base film layer comprises a plurality of diffusion structures, wherein the diffusion structures are hollow structures and diffusion particles are arranged in the diffusion structures.
2. The optical film according to claim 1, characterized in that: The diffusion structure is an ellipsoid structure.
3. The optical film according to claim 2, characterized in that: The diameter of at least part of the diffusion structure is less than 800 um.
4. The optical film according to claim 2, characterized in that: The diffusion particles are spherical structures.
5. The optical film according to claim 4, characterized in that: The diameter of at least part of the spherical structure is d, wherein 2um≤d≤50um.
6. The optical film according to any one of claims 1 to 5, characterized in that: The diffusion particles are hollow structures.
7. The optical film according to any one of claims 1 to 5, characterized in that: The diffusion particles are glass balls.
8. The optical film according to claim 6, characterized in that: The inner wall thickness of at least part of the diffusion particles is w, wherein 1 um≤w≤3 um.
9. The optical film according to claim 1, characterized in that: The optical film further comprises a first microstructure layer and a second microstructure layer, and the base film layer is located between the first microstructure layer and the second microstructure layer.
10. The optical film according to claim 9, characterized in that: The microstructures in the first microstructure layer include pyramid structures, and at least a portion of the pyramid structures have a vertex angle of a, wherein 80°<a≤100°.
11. The optical film according to claim 9, characterized in that: The microstructures in the second microstructure layer include pyramid structures, and the top angle of at least part of the pyramid structures is b, wherein 40°≤b≤80°.
12. The optical film according to claim 10 or 11, characterized in that: The height of at least part of the pyramid structure is h, wherein 20um≤h≤50um.
13. The optical film according to claim 9, characterized in that: The surfaces of the first microstructure layer and the second microstructure layer are both paved with a refractive layer, and the refractive index of the refractive layer is n, 1.0≤n≤2.
4.
14. The optical film according to claim 13, characterized in that: The thickness of the refractive layer is c, wherein 0.1 um≤c≤10 um.
15. A backlight module, characterized in that: The backlight module comprises the optical film according to any one of claims 1-14.
16. A display device, characterized in that: The display device comprises the backlight module as claimed in claim 15.