Light shielding film, optical element and electronic device

Abstract

The invention provides a shading film, an optical element and electronic equipment. The shading film is used for being arranged on the surface of a transparent substrate and comprises a matching layer and a light absorption layer, the matching layer and the light absorption layer are arranged in a stacked mode, the matching layer is used for being connected with the transparent substrate, the refractive index Nm of the matching layer is larger than the refractive index Na of the light absorption layer, the value range of the refractive index Nm of the matching layer is 0.85 Ns-1. 03Ns, and Ns is the refractive index of the transparent substrate. The light-vibrating film can be used for the surface of high-refractive-index glass, the reflectivity of a light-shading film is reduced, and the problems of stray light and ghosting are reduced.

Description

Technical Field

[0001] This application relates to the field of light-shielding materials, specifically to a light-shielding film and optical components and electronic devices. Background Technology

[0002] Light-shielding films are widely used in backlight modules of cameras, LCDs, and other electronic devices to block external light from entering. Ideally, a light-shielding film should completely absorb external light, achieving zero reflection. However, in current technology, light-shielding films often use black ink, relying on the absorption of light by the black ink layer to reduce reflectivity. In optical components, light-shielding films are typically placed on a transparent substrate, such as the surface of glass. For high-refractive-index glass, such as glass with a refractive index greater than 1.84, the existing inks have a relatively low refractive index, typically less than 1.65 (e.g., 1.63). This significant difference in refractive index between the ink and the glass causes reflection at the interface, resulting in stray light and ghosting, thus affecting the filtering or imaging effect. Summary of the Invention

[0003] This application provides a light-shielding film and optical and electronic components that reduce the reflectivity of the light-shielding film for high-refractive-index glass, thereby reducing stray light and ghosting problems.

[0004] In a first aspect, this application provides a light-shielding film for being disposed on the surface of a transparent substrate. The light-shielding film includes a matching layer and a light-absorbing layer, which are stacked together. The matching layer is used to connect with the transparent substrate. The refractive index Nm of the matching layer is greater than the refractive index Na of the light-absorbing layer, and the refractive index Nm of the matching layer is in the range of 0.85Ns to 1.03Ns, where Ns is the refractive index of the transparent substrate.

[0005] The light-shielding film of this application includes a high-refractive-index matching layer and a relatively low-refractive-index light-absorbing layer. When bonded to a high-refractive-index transparent substrate, since the refractive index Nm of the matching layer used for bonding with the transparent substrate is 0.85 to 1.03 times that of the refractive index Ns of the transparent substrate, the refractive indices of the two are similar after bonding. This reduces reflected light between the transparent substrate and the matching layer, increases transmitted light from the transparent substrate to the matching layer, and then the light is transmitted from the matching layer to the light-absorbing layer, where the remaining light is absorbed. In this light-shielding film, since the matching layer is used for bonding with the transparent substrate, the matching layer is mainly made to have a high refractive index during the fabrication of the light-shielding film to reduce the refractive index difference between the matching layer and the transparent substrate, thereby reducing stray light and ghosting problems. The light-absorbing layer mainly absorbs light, and its refractive index can be lower than that of the matching layer to achieve a high light-shielding effect.

[0006] In one alternative implementation, the refractive index Nm of the matching layer ranges from 0.985 Ns to 1.02 Ns. When the refractive index of the matching layer satisfies 0.985 Ns to 1.02 Ns, the refractive index matching degree between the matching layer and the transparent substrate can be further improved, the reflectivity at the interface between the two can be reduced, the transmittance from the transparent substrate to the matching layer can be increased, and thus the stray light and ghosting problems can be further reduced.

[0007] In one alternative implementation, the extinction coefficient of the matching layer in the 400nm–700nm wavelength band is greater than or equal to 0.0017μm. -1 And less than 0.03μm -1 Because this light-shielding film has a multilayer structure, the matching layer and the light-absorbing layer can perform different functions. Compared to light-shielding films with single-layer film structures, such as single-layer ink light-shielding films, the matching layer can be made of a material with a lower extinction coefficient, thereby increasing the range of material choices and reducing the manufacturing difficulty of the matching layer. At the same time, using a matching layer with the aforementioned extinction coefficient can also reduce the reflectivity between the light-shielding film and the light-transmitting substrate, thus reducing stray light.

[0008] In one alternative implementation, the extinction coefficient of the matching layer in the 400nm–700nm wavelength band is 0.0017–0.025 μm. -1 The extinction coefficient is 0.0017–0.025 μm. -1 When the matching layer with the extinction coefficient is used in conjunction with the transparent substrate, stray light between the light-shielding film and the transparent substrate can be further eliminated.

[0009] In one alternative implementation, the absorption coefficient of the matching layer in the 400nm–700nm wavelength band is 0.3–0.5 μm. -1 Since the matching layer primarily functions as a high-refractive layer, its absorption coefficient can be relatively low. However, compared to the transparent substrate, the absorption of the matching layer is much greater. When the absorption coefficient of the matching layer is between 0.3 and 0.5, it can help improve the overall light absorption effect of the light-shielding film.

[0010] In one alternative implementation, the matching layer has a thickness of 5–20 μm, such as 5–15 μm, or even 5–10 μm. Since the matching layer needs to possess a high refractive index, a large amount of high-refractive-index material needs to be added during the fabrication process. Excessive thickness can easily reduce the adhesion of the light-shielding film and decrease the stability of the matching layer. Therefore, setting the matching layer to a thinner thickness allows it to meet both high refractive index and high reliability requirements.

[0011] In one alternative implementation, the absorption coefficient of the light-absorbing layer in the 400nm–700nm wavelength band is 0.3–0.7 μm. -1The light-absorbing layer plays a major role in light absorption in the light-shielding film. When the light absorption coefficient of the light-absorbing layer is 0.3 to 0.7, a high-efficiency light absorption effect can be achieved.

[0012] In one alternative implementation, the thickness of the light-absorbing layer is 10–100 μm, for example, 10–80 μm, or even 10–40 μm. Since the refractive index of the light-absorbing layer is relatively low, its thickness can be made thicker to improve the light-blocking effect of the light-shielding layer.

[0013] In one alternative implementation, the refractive index of the light-absorbing layer is 1.5 to 1.7. A refractive index within this range provides the basic refractive index requirement for the light-shielding film. Furthermore, using this refractive index allows for a wider range of material choices and stable material properties, enabling the fabrication of thicker light-absorbing layers to improve light absorption, reduce transmission, and enhance the reliability of the light-absorbing layer.

[0014] In one alternative implementation, the matching layer comprises resin, inorganic filler, and pigment. The resin comprises 10–98% by volume, the inorganic filler comprises 0.1–60% by volume, and the pigment comprises 0.01–30% by volume. Among the materials forming the matching layer, the inorganic filler is a high-refractive-index inorganic material, primarily responsible for increasing the refractive index of the matching layer. The relatively high proportion of the inorganic filler in the above components ensures the high refractive index requirement of the matching layer.

[0015] Secondly, this application provides an optical element comprising a transparent substrate and a light-shielding film of this application disposed on the surface of the transparent substrate, a matching layer disposed between the transparent substrate and the light-absorbing layer and connected to the transparent substrate, the refractive index Ns of the transparent substrate being greater than 1.7, and the reflectivity of the optical element being less than 1%.

[0016] The optical element of this application, since the refractive index of the transparent substrate is greater than 1.7, can adapt to the development of ultra-thin optical elements. By setting the light-shielding film of the first aspect of this application on the surface of the transparent substrate with a high refractive index, the light-shielding film can be combined with the light-transmitting substrate with a high refractive index. The light-shielding film is used to achieve low reflection of incident light, with a reflectivity of less than 1%, thereby obtaining an optical element with high refractive index and low reflection.

[0017] Thirdly, this application provides an electronic device that includes the optical elements of this application.

[0018] The technical effects that can be achieved in the third aspect can be referred to the corresponding effect descriptions in the second aspect above, and will not be repeated here.

[0019] The electronic devices covered by this application may include mobile devices such as mobile phones, computers, and watches with camera modules, as well as devices such as displays with backlight modules.

[0020] In this application, the data in the various possible implementations, such as the extinction coefficient of the light-shielding film, the thickness of the matching layer, the absorption coefficient of the matching layer, the thickness of the light-absorbing layer, and the absorption coefficient of the light-absorbing layer, should all be understood as being within the range defined in this application when measured, provided that the values ​​are within the engineering measurement error range. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of the light-shielding film provided in the embodiments of this application;

[0022] Figure 2 This is a schematic diagram of the structure of the optical element provided in the embodiments of this application;

[0023] Figure 3 This is a schematic diagram of the light transmission path in an optical element according to an embodiment of this application;

[0024] Figure 4 This is a test pattern of the reflectivity of optical elements with matching layers of different thicknesses.

[0025] Figure label:

[0026] 10-Light-shielding film; 11-Matching layer; 12-Light-absorbing layer; 20-Transparent substrate. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this application clearer, the application will now be described in further detail with reference to the accompanying drawings.

[0028] The terminology used in the following embodiments is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. As used in the specification and appended claims of this application, the singular expressions “a,” “an,” “the,” “the,” and “this” are intended to also include expressions such as “one or more,” unless the context clearly indicates otherwise.

[0029] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0030] Existing light-shielding films are typically single-layer structures, primarily formed from black ink, but can also be made from resin. When using black ink to prepare a single-layer light-shielding film, due to material limitations, the refractive index of the black ink is generally below 1.65. When combined with a high-refractive-index glass substrate, the significant difference in refractive index between the black ink and the glass substrate causes reflection at the interface, resulting in stray light and ghosting, affecting filtering and imaging effects. Furthermore, when the light-shielding film is formed from resin materials, a large amount of high-refractive-index inorganic fillers needs to be added to the resin to obtain a high-refractive-index (greater than 1.8) resin compound. When making thick films with this resin material, it is difficult to obtain light-shielding films with a thickness exceeding 10 μm and stable performance due to the uniform dispersion of inorganic fillers and the stability of high-refractive-index resin materials. Moreover, when producing high-refractive-index light-shielding films with sufficient light-shielding performance using films smaller than 5 μm, the content of inorganic fillers, dyes, and pigments added to the resin is very high, which reduces the uniform dispersion of additives and the adhesion between the resin and the substrate, making it difficult to obtain a highly stable light-shielding film.

[0031] To address the aforementioned problems, this application provides a light-shielding film. The light-shielding film of this application embodiment may include a two-layer structure: a light-absorbing layer and a matching layer. The matching layer is used to contact a transparent substrate and is located between the transparent substrate and the light-absorbing layer. Since the light-absorbing layer of the light-shielding film of this application embodiment does not directly contact the substrate when used in optical components, the light-absorbing layer can be made relatively thick to ensure the stability and light-shielding effect of the light-shielding layer. The matching layer can be formed using a high-refractive-index material. After being combined with the transparent substrate, it can reduce reflected light between the light-shielding film and the transparent substrate, reducing stray light and ghosting problems. The matching layer mainly solves the problem of refractive index matching with the transparent substrate, reducing the requirements for its light absorption. Its material is not limited by existing light-absorbing layer materials, primarily aiming to obtain a high-refractive-index layer. The light-absorbing layer mainly plays a light-absorbing role, reducing the requirements for its refractive index. Therefore, it can be formed using a material with high absorbency and low refractive index. Compared with traditional single-layer light-shielding films, this reduces the preparation requirements of the light-absorbing layer and broadens the range of material choices for the light-absorbing layer. When combined with a transparent substrate with a high refractive index, the light-absorbing layer can also be formed using traditional black ink.

[0032] Figure 1 This is a schematic diagram of the structure of an optical element according to an embodiment of this application. The optical element includes a transparent substrate 20 and a light-shielding film 10. The transparent substrate 20 may be a glass substrate. The transparent substrate 20 may be a glass substrate with a high refractive index. In one embodiment, the refractive index of the glass substrate is greater than 1.7, such as 1.8, or higher, such as 1.84.

[0033] Figure 2 This is a schematic diagram of the structure of a light-shielding film 10 according to this application. See also... Figure 1 and Figure 2The light-shielding film 10 of this application embodiment includes a light-absorbing layer 12 and a matching layer 11. The matching layer 11 and the light-absorbing layer 12 are stacked. In the optical element, the matching layer 11 is bonded to the transparent substrate 20 and is located between the transparent substrate 20 and the light-absorbing layer 12.

[0034] The light-absorbing layer and the matching layer will be described separately below.

[0035] light-absorbing layer

[0036] Reference Figure 2 The light-absorbing layer 12 can be a black light-absorbing layer with a refractive index between 1.5 and 1.7. Compared to the matching layer 11, the light-absorbing layer 12 primarily provides light absorption and anti-reflection properties. Therefore, to obtain a light-absorbing layer 12 with higher light absorption performance, the light-absorbing layer 12 in this embodiment has an absorption coefficient of 0.3 to 0.7 μm in the 400 nm to 700 nm wavelength band. -1 For example, the absorption coefficient of the light-absorbing layer 12 may be 0.3 μm. -1 0.35μm -1 0.4μm -1 0.45μm -1 0.5μm -1 0.55μm -1 0.6μm -1 0.65μm -1 0.7μm -1 Or the value between any two of the above values.

[0037] Since the light-absorbing layer 12 in the light-shielding film of this application embodiment can have a low refractive index, its thickness can be made relatively thicker to achieve a better light absorption effect and reduce the transmittance of the light-shielding film 10. In one embodiment, the thickness of the light-absorbing layer 12 can be 10–100 μm, for example, 10–80 μm, 10–50 μm, or 10–40 μm. Exemplarily, the thickness of the light-absorbing layer 12 can be, for example, 10 μm, 12 μm, 14 μm, 16 μm, 18 μm, 20 μm, 22 μm, 24 μm, 26 μm, 28 μm, 30 μm, 32 μm, 34 μm, 36 μm, 38 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, or any value between two of these values.

[0038] The light-absorbing layer 12 can be formed using conventional inks or numerical materials. When formed using inks, commercially available products with a refractive index typically between 1.6 and 1.64 can be used. When the light-absorbing layer 12 is formed using resin materials, the materials used to prepare the light-absorbing layer 12 include resin, inorganic fillers, pigments, solvents, and binders. The amount of inorganic fillers added can be relatively small to avoid affecting the film-forming properties of the light-absorbing layer 12.

[0039] The resin can be a thermosetting resin or a UV-curable resin. Examples of thermosetting resins include epoxy resin, polyimide, silicone resin, and fluorite resin. Examples of UV-curable resins include acrylic resin, epoxy resin, polyimide, silicone resin, and fluorite resin.

[0040] The inorganic filler is a high-refractive-index inorganic nanomaterial. Examples of inorganic fillers include titanium dioxide, zirconium oxide, and nanodiamond. Since the refractive index of the light-absorbing layer can be relatively low, the amount of inorganic filler added can be relatively small.

[0041] Pigments can be selected from black substances such as carbon black, titanium black, and iron oxide.

[0042] The solvent can be an organic solvent, such as propylene glycol methyl ether acetate (PGMEA), tetrahydrofuran (THF), methyl ethyl ketone (MEK), ethyl acetate (EAC), ethylene glycol methyl ether acetate (BAC), N-methylpyrrolidone (NMP), acetone, toluene, alcohols, etc.

[0043] The adhesive may be, for example, a silane coupling agent. The adhesive may be mixed with the above components, or it may be applied to the surface of the substrate or matching layer before applying the light-absorbing layer to improve adhesion to the substrate.

[0044] In one embodiment, a silica-based material or a gel material may be added to the resin material component forming the light-absorbing layer. The silica-based material may be, for example, silsesquioxane, and the sol-gel material may be, for example, an organic alkoxide or a metal alkoxide. Alternatively, the light-absorbing layer may be prepared solely from silsesquioxane or sol-gel material.

[0045] Matching layer

[0046] Continue to refer to Figure 2The matching layer 11 can be a black light-absorbing layer 12 or a gray matching layer 11. The refractive index of the matching layer 11 is greater than that of the light-absorbing layer 12, and its main function is to provide the high refractive index required for the light-shielding film 10. Therefore, the refractive index of the matching layer 11 is higher than that of the light-absorbing layer 12. In one embodiment, the refractive index Nm of the matching layer 11 is greater than 1.7, and Nm can also be, for example, 1.75, 1.78, 1.8, 1.84 or higher. At the same time, since the requirements for light reflection and absorption of the matching layer 11 are relatively low, the absorption coefficient of the matching layer 11 can be lower than that of the light-absorbing layer 12. In one embodiment, the absorption coefficient of the matching layer 11 in the 400nm to 700nm wavelength band is 0.3 to 0.5 μm. -1 For example, the absorption coefficient of the matching layer 11 may be 0.3 μm. -1 0.32μm -1 0.34μm -1 0.36μm -1 0.38μm -1 0.4μm -1 0.42μm -1 0.44μm -1 0.46μm -1 0.48μm -1 0.5μm -1 Or the value between any two of the above values.

[0047] Because the matching layer 11 has a high refractive index, its thickness can be set relatively small. In one embodiment, the film thickness of the matching layer 11 can be 5–20 μm, for example 5–15 μm, or even 5–10 μm. Exemplarily, the thickness of the matching layer 11 can be, for example, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, 16 μm, 17 μm, 18 μm, 19 μm, 20 μm, or any two of these values.

[0048] In this embodiment, the extinction coefficient of the matching layer at wavelengths from 400 nm to 700 nm is 0.001 μm. -1 To less than 0.03μm -1 For example, the extinction coefficient can be 0.0017–0.025 μm. -1 For example, the extinction coefficient of the matching layer can be, for instance, 0.001 μm. -1 0.002μm -1 0.005μm -1 0.008μm -1 0.01μm -1 0.012μm -1 0.015μm -10.018μm -1 0.020μm -1 0.022μm -1 0.025μm -1 0.028μm -1 or 0.029μm -1 Or any value between the two values ​​above. Using a matching layer with the above extinction coefficient can reduce the manufacturing difficulty of the matching layer, broaden the range of diffusion materials, and help reduce the reflectivity between the light-shielding film and the substrate, thus reducing stray light.

[0049] The material forming the matching layer 11 can be a resin material or an inorganic gel material. When the material forming the matching layer 11 is a resin material, the material forming the matching layer 11 can include resin, inorganic filler, pigment, solvent and adhesive.

[0050] The resin can be a thermosetting resin or a UV-curable resin. Examples of thermosetting resins include epoxy resin, polyimide, silicone resin, and fluorite resin. Examples of UV-curable resins include acrylic resin, epoxy resin, polyimide, silicone resin, and fluorite resin.

[0051] The inorganic filler is a high-refractive-index inorganic nanomaterial. Examples of inorganic fillers include titanium dioxide, zirconium oxide, and nanodiamond. Since the matching layer requires a high refractive index, the content of the inorganic filler in the numerical material forming the matching layer is relatively high to obtain a high-refractive-index matching layer. When increasing the inorganic filler content to obtain a high-refractive-index matching layer, the thickness of the matching layer needs to be set relatively low to prevent excessive inorganic filler from reducing the stability of the matching layer.

[0052] Pigments can be selected from black substances such as carbon black, titanium black, and iron oxide.

[0053] The solvent can be an organic solvent, such as PGMEA, THF, MEK, EAC, BAC, NMP, acetone, toluene, alcohol, etc.

[0054] The adhesive may be, for example, a silane coupling agent. The adhesive may be mixed with the above components, or it may be applied to the surface of the substrate or matching layer before applying the light-absorbing layer to improve adhesion to the substrate.

[0055] In one embodiment, a siloxane-based material or a gel-based material may be added to the resin material forming the light-absorbing layer. The siloxane-based material may be, for example, silsesquioxane, and the sol-gel material may be, for example, an organic alkoxide or a metal alkoxide. Alternatively, the light-absorbing layer may be prepared solely from silsesquioxane or sol-gel material.

[0056] In one embodiment, the resin material forming the matching layer, by weight fraction, may include, for example, resin, inorganic filler, pigment, solvent, and binder. In this embodiment, the amount of inorganic filler added to the matching layer material is relatively high; therefore, when the matching layer is prepared using this material, the thickness of the matching layer can be relatively low. In one embodiment, the volume percentage of resin is 10-98%, the volume percentage of inorganic filler is 0.1-60%, and the volume percentage of pigment is 0.01-30%. Exemplarily, the volume percentage of resin may be, for example, any two values ​​between 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or 98% or higher. The volume percentage of inorganic filler may be, for example, any two values ​​between 0.1%, 1%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, or 60% or higher. The volume percentage of the pigment can be, for example, any two values ​​between 0.01%, 0.1%, 1%, 5%, 8%, 10%, 12%, 15%, 18%, 20%, 22%, 24%, 27%, 30% or more.

[0057] The light-shielding film provided in this application embodiment has a double-layer film structure. Compared with a single-layer light-shielding film, it has a high refractive index while exhibiting lower reflectivity and higher reliability. In one embodiment, the refractive index of the light-shielding film is greater than 1.8. Furthermore, the light-shielding film of this application embodiment can be applied to the surface of a high-refractive-index transparent substrate, utilizing the interaction between the matching layer and the transparent substrate to reduce stray light at the interface between the two.

[0058] Reference Figure 1 In the optical element of this application embodiment, the light-incident side is one side of the transparent substrate 20, and the light-exit side is one side of the light-absorbing layer 12. Light is transmitted from the transparent substrate 20 to the matching layer 11, and after being refracted by the matching layer 11, it enters the light-absorbing layer 12. To reduce the reflected light at the interface between the transparent substrate 20 and the matching layer 11, in the optical element of this application, the refractive index Nm of the matching layer 11 ranges from 0.85 Ns to 1.03 Ns, for example, 0.89 Ns to 1.03 Ns, for example, 0.92 Ns to 1.03 Ns, for example, 0.95 Ns to 1.02 Ns, for example, 0.985 Ns to 1.02 Ns. In this embodiment, the refractive index of the transparent substrate 20 is greater than 1.7, for example, greater than 1.8, for example, greater than 2.0. The light-shielding film of this application can be used in high refractive index substrates to reduce stray light and imaging problems of high refractive index optical elements, and reduce the manufacturing difficulty of high refractive index optical elements, making it possible to process and fabricate high refractive and low reflective optical elements.

[0059] Figure 3 This is a schematic diagram of the light transmission path in an optical element according to an embodiment of this application. Figure 3As shown, after external light reaches the interface between the transparent substrate 20 and the matching layer 11, most of the light enters the matching layer 11 at this interface, while a small portion is reflected and re-enters the transparent substrate 20. Most of the light transmitted through the matching layer 11 to the interface between the light-absorbing layer 12 and the matching layer 11 enters the light-absorbing layer 12 and is absorbed, while a small portion is reflected and re-enters the matching layer 11. After passing through the light-absorbing layer 12, most of the light is reflected back to the light-absorbing layer 12 on its back side, undergoing repeated absorption. Since both the matching layer 11 and the light-absorbing layer 12 have high absorption coefficients, most of the light entering them is absorbed. The amount of reflected light mainly depends on the reflection at the interface between the transparent substrate 20 and the matching layer 11; therefore, the reflectivity of the optical element mainly depends on the reflection at the interface between the transparent substrate 20 and the matching layer 11. Because the refractive index difference between the matching layer 11 and the transparent substrate 20 is small, the reflectivity at their interface is also low. Through the combined effect of the matching layer 11 and the light-absorbing layer 12, the reflectivity of the optical element in this embodiment can be less than 1%, or even less than 0.5%, or for example, less than 0.01%. The refractive index of the matching layer 11 is similar to or the same as that of the substrate, so as to minimize the stray light and ghosting problems that occur between the light-shielding film 10 and the substrate.

[0060] The structure of the optical element has been explained above. The performance of the optical element in this application will be further verified and explained below with reference to test data.

[0061] Example 1

[0062] This embodiment is an optical element, including a glass substrate, a matching layer, and a light-absorbing layer. The glass substrate has a refractive index of 1.84, the matching layer has a refractive index of 1.84, and the light-absorbing layer has a refractive index of 1.53. The light-absorbing layer is a black ink layer. The matching layer can be a black matching layer or a gray matching layer.

[0063] Examples 2-9

[0064] Examples 2-9 are optical elements with the same structure as Example 1, except that the parameters of each layer are different. The specific parameters are listed in Table 1.

[0065] Comparative Example 1

[0066] The optical element in this comparative example has the same structure as that in Example 1. The difference is that the value of Nm in this comparative example is not within the range defined in this application.

[0067] Comparative Example 2

[0068] The optical element in this comparative example includes a glass substrate and a light-absorbing layer, but no matching layer. The glass substrate has a refractive index of 1.84, and the light-absorbing layer is an ink layer with a refractive index of 1.63.

[0069] The reflectivity of optical elements in different embodiments and comparative examples was tested, and the test results are listed in Table 1.

[0070] Table 1

[0071]

[0072] Note: When testing the reflectivity of optical elements in different embodiments and comparative examples, the incident angle of the test beam was 68°.

[0073] As can be seen from the relevant test data of Examples 1 to 9 in Table 1, the reflectivity of the optical elements in the embodiments of this application is all below 1%. The reflectivity of some embodiments is below 0.1%. Therefore, it can be seen that when using high-refractive-index glass, optical elements with even lower reflectivity can be obtained in the embodiments of this application.

[0074] The test data from Examples 1 to 3 show that when the refractive index of the substrate is 1.84, the refractive index of the matching layer can be close to that of the substrate, and the refractive index of the light-absorbing layer can be set relatively low. A light-absorbing layer with a refractive index of 1.53 can be obtained using commercially available inks. The final reflectivity of the optical elements corresponding to Examples 1 to 3 is all below 0.1%. When the refractive index of the matching layer changes, the reflectivity of the corresponding optical elements changes slightly, but not significantly.

[0075] The comparative data from Examples 1 and 4 show that the reflectivity of the optical element tends to decrease when the refractive index of the light-absorbing layer is increased.

[0076] The comparative data from Examples 4 and 5 show that increasing the thickness of the matching layer can further reduce the reflectivity of the optical element.

[0077] As can be seen from the relevant test data of Examples 6 and 7, the reflectivity of the final optical element can be changed by changing the light absorption coefficient and the thickness of the matching layer.

[0078] As can be seen from the test data of Example 8, the greater the difference between the refractive index of the matching layer and the refractive index of the substrate, the greater the reflectivity of the obtained optical element will be. This indicates that the difference in refractive index between the matching layer and the substrate has an important influence on the reflectivity of the final optical element.

[0079] The test data from Example 9 shows that when the refractive index of the substrate is 1.84 and the refractive index of the matching layer is +1.81, the final reflectivity of the optical element is significantly improved. However, even using the combination of Example 9, an optical element with a reflectivity of less than 1% can be obtained.

[0080] As can be seen from the comparison data of Example 4 and Comparative Example 1, when the refractive index difference between the matching layer and the substrate is large, such as when the refractive index of the matching layer in Comparative Example 1 is 1.51, the reflectivity of the corresponding optical element reaches 62.4%.

[0081] As shown in Comparative Example 2, when the optical element does not contain a matching layer, the reflectivity of the corresponding optical element is 49%.

[0082] As can be seen from the above comparison, the light-shielding film of the present application embodiment can achieve better light-shielding effect, especially in the application scenario of high refractive index glass, which can significantly reduce the reflectivity of optical components.

[0083] Figure 4 This is a test graph showing the reflectivity of optical elements with matching layers of different thicknesses. Figure 4 Figure (a) shows the reflectance spectra under different absorption coefficients. Figure 4 Figure (b) is an enlarged view of point A in Figure (a). For example... Figure 4 As shown, the overall reflectivity of the optical element decreases with increasing matching layer thickness. Furthermore, when the absorption coefficient of the matching layer is 0.3-0.5 μm... -1 At that time, the reflectivity of the optical elements was all below 0.01%.

[0084] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A light shielding film for being provided on a surface of a transparent substrate, characterized by, The light shielding film comprises a matching layer and a light absorbing layer, the matching layer and the light absorbing layer are arranged in a stack, the matching layer is used to connect with the transparent substrate, the refractive index Nm of the matching layer is greater than the refractive index Na of the light absorbing layer, and the refractive index Nm of the matching layer ranges from 0.85Ns to 1.03Ns, Ns being the refractive index of the transparent substrate.

2. The light shielding film according to claim 1, wherein The refractive index Nm of the matching layer ranges from 0.985Ns to 1.02Ns.

3. The light shielding film according to claim 1 or 2, wherein The extinction coefficient of the matching layer in the 400-700 nm band is greater than or equal to 0.0017 and less than 0.03 μm -1 .

4. The light shielding film according to any one of claims 1 to 3, wherein The extinction coefficient of the matching layer in the 400nm-700nm waveband is 0.0017-0.025μm -1 .

5. The light shielding film according to any one of claims 1 to 4, wherein The refractive index of the light shielding film is greater than 1.

8.

6. The solar control film of any of claims 1-5, wherein, The light absorption coefficient of the matching layer in the 400-700 nm band is 0.3-0.5 μm -1 .

7. The solar control film of any of claims 1-6, wherein, The film thickness of the matching layer ranges from 5 to 20 microns.

8. The solar control film of any of claims 1-7, wherein, The light absorption coefficient of the light absorption layer in the 400-700 nm waveband is 0.3-0.7 μm -1 .

9. The solar control film of any of claims 1-8, wherein, The film thickness of the light absorbing layer ranges from 10 to 100 microns.

10. The solar control film of any of claims 1-9, wherein, The refractive index of the light absorbing layer ranges from 1.5 to 1.

7.

11. The solar control film of any of claims 1-10, wherein, The material of the matching layer comprises resin, inorganic filler and pigment, in the matching layer, the volume percentage of the resin ranges from 10 to 98%, the volume percentage of the inorganic filler ranges from 0.1 to 60%, and the volume percentage of the pigment ranges from 0.01 to 30%.

12. An optical element, characterized by, The transparent substrate and the light shielding film as claimed in any one of claims 1 to 11 are arranged on the surface of the transparent substrate, the matching layer is arranged between the transparent substrate and the light absorbing layer and connected with the transparent substrate, the light entrance side of the optical element is the transparent substrate side, the refractive index Ns of the transparent substrate is greater than 1.7, and the reflectivity of the optical element is less than 1%.

13. An electronic device, comprising: The optical element as claimed in claim 12 is comprised.

Images