Multifunctional optical film and vision correction lens comprising the same

Abstract

The present application relates to the field of optical devices, in particular to a multifunctional optical film and a vision correction lens comprising the same, the vision correction lens comprises, from the lens substrate outward, a bonding layer, a first gradient refractive index layer, an embedded spectrum-selective reflection layer, a second gradient refractive index layer, and a protective layer, wherein the refractive index of the first gradient refractive index layer and the second gradient refractive index layer continuously decreases from the bonding layer to the protective layer, and the embedded spectrum-selective reflection layer comprises a bottom high-reflection multilayer film, a silicon dioxide spacer layer, and a top high-reflection multilayer film which are stacked in sequence; the problems of excessive total film thickness, increased interface reflection, mutual interference of spectral performance, and strong edge field angle dependence caused by simultaneously combining an anti-reflection film and a blue light protection film on a vision correction lens with large curvature are solved.

Description

Technical Field

[0001] This invention relates to the field of optical devices, and more particularly to multifunctional optical thin films and vision correction lenses comprising such films. Background Technology

[0002] Currently, the optical functional coating technology applied to resin eyeglass lenses is quite mature. The mainstream solution generally adopts vacuum physical vapor deposition technology, which stacks multiple layers of inorganic dielectric films with different refractive indices, such as titanium dioxide and silicon dioxide, on the lens substrate. By precisely controlling the optical thickness of each film, various functions are achieved by utilizing the principle of light interference.

[0003] Anti-reflective coatings typically employ a stack of quarter-wavelength films composed of alternating high and low refractive index materials. They reduce the reflectivity of the lens surface in the visible light band through the principle of destructive interference, thereby improving light transmittance and visual clarity. Blue light blocking films are mainly divided into two categories: absorptive types, which filter out specific wavelengths of blue light by adding organic or inorganic absorbers to the film layer or lens substrate; and reflective types, which utilize optical interference filters composed of multiple dielectric films to reflect specific wavelengths of blue light. The latter is often used in high-end products due to its controllable performance and durability. The aforementioned layered, stacked thin-film technology system has a clear technical principle and a high degree of standardization in its production process, enabling it to independently enhance various functions such as anti-reflection and blue light blocking to a high level.

[0004] However, when attempting to integrate high-performance anti-reflective properties with blue light blocking functions into the same lens, especially for high myopia lenses with large curvature, the existing layered stacking technology reveals its inherent and irreconcilable contradictions:

[0005] First, anti-reflective coatings aim to achieve extremely low reflectivity across the widest possible visible light band; while anti-blue light coatings need to form high reflectivity peaks in specific narrow bands. Simply physically stacking these two optical designs results in their spectral curves interfering with each other, often at the cost of sacrificing overall transmittance, introducing unwanted color shifts, or compressing the effective spectral selectivity bandwidth, making it difficult to achieve both high transmittance and strong protection.

[0006] Secondly, the performance of thin films based on the principle of interference changes significantly with the angle of light incidence. In the large-angle area at the edge of highly myopic lenses, the reflective peak of traditional blue light blocking films undergoes a blue shift, leading to protection failure. At the same time, the anti-reflection effect deteriorates, causing stray light and chromatic aberration in the peripheral field of vision, affecting visual comfort.

[0007] Furthermore, the continuous stacking of multilayer films to achieve complex functions can lead to problems such as increased total thickness, accumulated internal stress, decreased interlayer adhesion, and challenges in abrasion resistance, affecting the reliability and durability of the product.

[0008] It can be seen that although existing technologies can optimize a single function, their simple stacking of functional modules lacks an integrated solution when faced with the core contradiction in spectral management—between high transmittance in a wide band and precise control in a narrow band—leading to compromises in the overall optical performance, angular stability, and physical reliability of the product.

[0009] The information disclosed in this background section is intended only to enhance the understanding of the general background of this disclosure and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0010] This invention provides a multifunctional optical thin film and a vision correction lens containing the thin film, which solves the problems of excessive total film thickness, increased interface reflection, mutual interference of spectral performance, and strong dependence on edge field of view angle caused by simultaneously composited anti-reflective film and blue light blocking film on vision correction lenses with large curvature.

[0011] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0012] The first aspect of this invention provides a multifunctional optical film for vision correction lenses, comprising, from the lens substrate outwards:

[0013] bonding layer;

[0014] First gradient refractive index layer;

[0015] Embedded spectrally selective reflective layer;

[0016] The second gradient refractive index layer; and

[0017] Protective layer;

[0018] The refractive indices of the first and second gradient refractive index layers decrease continuously from the bonding layer toward the protective layer. The embedded spectrally selective reflective layer comprises a bottom high-reflectivity multilayer film, a silicon dioxide spacer layer, and a top high-reflectivity multilayer film stacked sequentially.

[0019] In this invention, the embedded spectrally selective reflective layer consists of a bottom high-reflectivity multilayer film, a top high-reflectivity multilayer film, and a silica spacer layer sandwiched between them, forming an optical Fabry-Perot type resonant cavity. The optical thickness of the silica spacer layer is precisely designed to be half the target center wavelength. The high-reflectivity multilayer film acts as a cavity mirror, enabling the light of the target wavelength to undergo resonant constructive interference within the cavity, drastically amplifying the light intensity and achieving efficient directional reflection. For non-resonant wavelengths (such as light >460nm), the structure is approximately transparent, thereby achieving precise selection of narrowband spectra.

[0020] Based on this, the first and second gradient refractive index layers continuously decrease in refractive index from the bonding layer to the protective layer, forming a wide-spectrum continuous gradient transition region of refractive index. This decomposes the optical transition from the high-refractive-index lens substrate to the low-refractive-index air into countless tiny refractive index changes, thereby fundamentally reducing broadband interface reflection caused by drastic refractive index changes and ensuring extremely high transmittance in the main visible light band of 460~780nm.

[0021] The coupled design of the two layers means that the gradient refractive index layer not only performs broadband antireflection function itself, but also smoothly embeds the embedded spectral selective reflective layer into the entire film system. This eliminates the strong interface reflection that occurs when the embedded spectral selective reflective layer is in direct contact with the high refractive index substrate and the low refractive index air, ensuring that the embedded spectral selective reflective layer can independently and accurately achieve its narrowband spectral selective reflection without destroying the overall optical path.

[0022] Preferably, the bonding layer is made of titanium oxide and has a thickness of 10-20 nm.

[0023] More specifically, the present invention defines the bonding layer as a dense titanium oxide structure. Titanium oxide can form stronger chemical bonds and physical adsorption with the resin lens substrate, improving the reliability and durability of the product. At the same time, the higher refractive index can achieve better optical matching with the high refractive index lens substrate, reducing the reflection loss at the first interface when light enters the multifunctional optical film from the substrate, laying a more solid foundation for achieving extremely low overall reflectivity.

[0024] Preferably, both the bottom high-reflectivity multilayer film and the top high-reflectivity multilayer film are composed of alternating layers of titanium oxide and silicon dioxide, and the total physical thickness of the bottom high-reflectivity multilayer film and the top high-reflectivity multilayer film is 500~1200nm.

[0025] By using alternating layers to form a high-reflectivity multilayer film, the required high reflectivity can be reliably achieved through interference effects. By limiting the total physical thickness to the range of 500~1200nm, the cavity mirror can be ensured to have sufficient reflection intensity to form a sharp resonance peak, while avoiding stress accumulation, decreased adhesion, and production yield and cost issues caused by excessive film thickness. This achieves the best balance between optical performance and process reliability.

[0026] Preferably, the bottom high-reflectivity multilayer film has a higher reflectivity to the target wavelength than the top high-reflectivity multilayer film.

[0027] This invention utilizes an asymmetric design where the reflectivity of the bottom high-reflectivity multilayer film for the target wavelength is higher than that of the top high-reflectivity multilayer film. This design allows specific wavelength light enhanced by intracavity resonance to be efficiently output to the outside of the lens, thereby maximizing the spectral selective reflection function.

[0028] Preferably, the optical thickness of the silicon dioxide spacer layer is 0.9 to 1.1 times half of any center wavelength in the range of 415 to 455 nm.

[0029] By setting the optical thickness of the silicon dioxide spacer layer to 0.9 to 1.1 times half of any center wavelength within the range of 415 to 455 nm, a Fabry-Perot resonant cavity can be precisely constructed. This optical thickness is a key condition for enabling the target wavelength to undergo resonant constructive interference within the cavity, thereby achieving efficient reflection of specific harmful blue light.

[0030] Preferably, the first gradient refractive index layer and / or the second gradient refractive index layer are co-sputtered gradient composite layers of titanium oxide and silicon dioxide, and the total physical thickness of the first gradient refractive index layer and the second gradient refractive index layer is 100~300nm.

[0031] Co-sputtering of titanium dioxide and silicon dioxide allows for precise and continuous control of the refractive index, thereby creating the required gradient change to maximize the antireflection effect. By controlling the total physical thickness within the range of 100~300nm, it is possible to ensure a sufficiently smooth refractive index transition to achieve broadband and efficient antireflection, while avoiding stress accumulation and adhesion risks caused by excessive film thickness, thus achieving a balance between optical performance and mechanical reliability.

[0032] Preferably, the refractive index of the first gradient refractive index layer gradually changes from 2.0±0.1 to 1.8±0.1; and / or, the refractive index of the second gradient refractive index layer gradually changes from 1.8±0.1 to 1.46±0.1.

[0033] The first gradient refractive index layer is responsible for connecting the high refractive index interface, and the second gradient refractive index layer is responsible for connecting the low refractive index external environment. This step-by-step gradient can most effectively eliminate broadband reflections from multiple interfaces. The above refractive index range ensures the physical property compatibility and process feasibility with the adjacent layer materials, while the tolerance of ±0.1 provides the necessary adjustment space for the actual coating process, ensuring the anti-reflection effect while taking into account production feasibility.

[0034] Preferably, the protective layer comprises a dense silicon dioxide layer and a diamond-like carbon film stacked sequentially from the inside out, wherein the physical thickness of the dense silicon dioxide layer is 20~30nm and the physical thickness of the diamond-like carbon film is 3~5μm.

[0035] The protective layer of the present invention is composed of a dense silica layer and a diamond-like carbon film. The dense silica layer fills the microscopic defects on the surface and provides a chemically inert interface; the diamond-like carbon film on the outer layer provides hardness, achieving scratch resistance, wear resistance and corrosion resistance.

[0036] A second aspect of the present invention provides a vision correction lens, comprising a lens substrate, wherein the aforementioned multifunctional optical thin film is disposed on at least one optical surface of the lens substrate.

[0037] Due to the high curvature concave optical design required for high myopia lenses, the angle of incidence of light at the lens edges is significantly increased. The synergistic design of the two gradient refractive index layers and the embedded spectrally selective reflective layer in this invention possesses inherent angle insensitivity in optical principles. The continuous refractive index change of the gradient layer is essentially non-interfering, and the resonant filtering effect of the embedded spectrally selective reflective layer is far less dependent on angle than traditional broadband interference filters. Therefore, it can solve the problem of edge optical degradation in high curvature lenses. It ensures that the anti-reflection effect and blue light blocking effect remain highly consistent from the optical center to the outermost region of the lens, ensuring that the peripheral and central visual fields are equally clear and stable. Furthermore, it effectively suppresses stray reflections and dispersion caused by large angles and thick edges, thereby reducing glare, ghosting, and color fringing in the peripheral visual field, and improving visual comfort and realism.

[0038] Preferably, the lens substrate is made of resin. High-refractive-index polyurethane resin, polycarbonate resin, or acrylic resin are preferred. Resin materials have a significantly lower density than glass, which is beneficial for achieving lightweight eyeglasses. They are particularly suitable for manufacturing high-curvature lenses for high myopia. Furthermore, their inherently high refractive index allows for better optical matching and stress coordination with the titanium dioxide bonding layer and gradient refractive index film system. This provides an ideal and reliable substrate platform for multifunctional optical films to exert their high performance in broadband antireflection and narrowband spectral selectivity, while ensuring safe and comfortable wear.

[0039] Preferably, the average reflectance of the vision correction lens is not less than 30% in the 415nm to 455nm wavelength range and not more than 0.8% in the 460nm to 780nm wavelength range.

[0040] A reflectance of no less than 30% ensures an effective protective barrier against harmful blue light in the 415~455nm wavelength range; while an average reflectance of no more than 0.8% achieves extremely high light transmittance and visual clarity in the main visible light wavelength range of 460~780nm.

[0041] The technical solution of this invention can achieve the following technical effects:

[0042] This invention achieves both ultra-wideband antireflection and precise narrowband spectral selection within a single film architecture. The gradient refractive index layer ensures extremely high transmittance (>99%) and extremely low average reflectance (<0.8%) in the 460–780 nm wavelength range, while the embedded spectrally selective reflective layer achieves highly efficient reflection of harmful blue light in the 415–455 nm range (reflectance >30%). The perfect superposition of their spectral curves fundamentally avoids the problems of mutual constraint between the two functions in traditional stacking methods, which leads to a decrease in overall transmittance and severe color shift.

[0043] This invention, through precise control of the resonant wavelength and bandwidth of the embedded spectrally selective reflective layer, can selectively reflect specific harmful short-wavelength blue light while maintaining high transmittance for beneficial long-wavelength blue light (460~500nm) that regulates human circadian rhythms. Therefore, the lens provides effective protection while exhibiting a near-colorless visual effect, maximizing the reproduction of natural colors and avoiding visual dullness and color distortion caused by excessive blue light blocking.

[0044] Since the antireflection effect of the gradient refractive index layer and the resonant filtering effect of the embedded spectrally selective reflective layer are far less dependent on the incident angle than traditional interference film stacks, the optical film of this invention exhibits minimal performance degradation under large incident angles. For high myopia lenses with large curvature, it ensures that the wearer can obtain a consistently clear field of vision, stable protection against harmful blue light, and extremely low edge glare and dispersion, regardless of whether they are viewing objects through the center or the edge of the lens. This solves the problem of traditional coatings failing in the peripheral area of ​​the lens. Attached Figure Description

[0045] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0046] Figure 1 A schematic diagram of a vision correction lens containing the multifunctional optical film of the present invention on one side;

[0047] Reference numerals: 100, lens substrate; 201, bonding layer; 202, first gradient refractive index layer; 203, bottom high-reflection multilayer film; 204, silica spacer layer; 205, top high-reflection multilayer film; 206, second gradient refractive index layer; 207, protective layer. Detailed Implementation

[0048] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0049] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0050] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application.

[0051] This application provides a vision correction lens, including a lens substrate, on which at least one optical surface is provided a multifunctional optical film of the present invention; wherein the lens substrate is made of resin lens, and its optical surface to be coated is subjected to rigorous ultrasonic cleaning and plasma activation treatment to remove organic stains and improve surface activity, providing a clean and highly adhesive substrate for subsequent film layers.

[0052] Specifically, the multifunctional optical thin film is a layered structure that is stacked sequentially from the surface of the lens substrate outwards. The specific parameters and functions of each layer are as follows:

[0053] Bonding Layer: A dense titanium dioxide film, with a thickness controlled at 10-20 nm, is deposited on the activated lens substrate using reactive magnetron sputtering. The main functions of this bonding layer are: firstly, to utilize the excellent chemical affinity between titanium dioxide and the resin material to form strong chemical bonds and physical adsorption, fundamentally improving the adhesion and long-term reliability of the entire film system to the substrate; and secondly, to achieve excellent optical matching between its high refractive index and the high refractive index of the lens substrate, effectively reducing Fresnel reflection loss at the first interface when light enters the multifunctional optical film from the lens substrate, laying the foundation for achieving extremely low overall reflectivity.

[0054] First-gradient refractive index layer: Using a dual-target co-sputtering technique with titanium dioxide and silicon dioxide, a thin film with a continuously gradient refractive index is deposited by precisely programming and controlling the sputtering power ratio of the two materials. The core function of this layer is to initiate broadband antireflection and achieve optical transition: its refractive index continuously and smoothly changes from about 2.0 on the side adjacent to the bonding layer to about 1.8 on the outer side. The continuous refractive index gradient decomposes the optical transition from the high-refractive-index bonding layer to the subsequent microcavity layer into countless tiny changes, thereby greatly suppressing broadband reflection at this interface. At the same time, the first-gradient refractive index layer provides a gradually changing refractive index access platform for the embedded spectrally selective reflective layer, avoiding the strong interface reflection that occurs when the high-reflectivity multilayer film at the bottom of the microcavity comes into direct contact with the lens substrate.

[0055] Embedded spectrally selective reflective layer: This is the core layer for achieving narrowband spectrally selective reflection in this invention, with the goal of efficiently reflecting blue light at a center wavelength of 430nm; its specific structure and function are as follows:

[0056] Bottom high-reflectivity multilayer film: As the first high-reflectivity cavity mirror of the microcavity, it is composed of 7 layers of TiO2 (high refractive index layer H, n≈2.3) and SiO2 (low refractive index layer L, n≈1.46) stacked alternately. The optical thickness of each layer is precisely controlled to be one-quarter of the target wavelength (430nm) (approximately 107.5nm), forming (HL). 3 The H-structure functions to form an optical barrier with a reflectivity higher than 99.5% at 430nm, effectively confining light of the target wavelength within the cavity formed by the embedded spectrally selective reflective layer.

[0057] Silica spacer layer: A pure silica film is deposited on the bottom high-reflectivity multilayer film, with its optical thickness precisely designed to be half the target wavelength (430nm). Calculated based on n≈1.46, its physical thickness is approximately 147nm. Its function is to form a Fabry-Perot resonant cavity with an optical thickness of half the wavelength together with the bottom and top high-reflectivity multilayer films. This specific optical thickness is crucial for ensuring that 430nm light meets the resonance condition within the cavity, leading to constructive interference of this wavelength of light within the cavity and a dramatic increase in light intensity.

[0058] Top high-reflectivity multilayer film: Serving as the second cavity mirror of the microcavity, it consists of 5 layers of alternating TiO2 and SiO2, each with an optical thickness of λ / 4, forming (HL). 2 The H-structure is designed with a reflectivity slightly lower than that of the bottom high-reflectivity multilayer film, allowing more of the 430nm light, enhanced by resonance within the cavity, to be efficiently coupled and output to the outside of the lens through the top cavity mirror, thus achieving efficient and directional reflection of this specific wavelength of light. For other wavelengths deviating from 430nm, since the resonance condition is not met, the microcavity structure is approximately transparent with minimal transmission loss.

[0059] The embedded spectrally selective reflective layer of this invention constitutes an optical Fabry-Perot type resonant cavity. When 430nm blue light is incident perpendicularly, it is partially reflected by the top high-reflectivity multilayer film and partially transmitted into the cavity. The transmitted light is reflected back and forth between the bottom nearly 100% reflective mirror and the top 95% reflective mirror. Since the cavity length is half a wavelength, all reflected light is superimposed in phase at the top interface, resulting in resonance. This makes it almost impossible for 430nm light to pass through the entire microcavity structure. Instead, it is greatly amplified and reflected back along the original path, thus being efficiently removed. For other wavelengths of light that deviate from 430nm, such as blue light and green-red light above 460nm, they do not meet the resonance condition, and their interference effect is not significant. Therefore, most of the energy can directly pass through the entire microcavity structure, producing only a small loss.

[0060] The second gradient refractive index layer: A second gradient refractive index film, approximately 100 nm thick, is deposited using a TiO2 and SiO2 co-sputtering technique similar to the first layer. Its refractive index is controlled to gradually change from approximately 1.8 near the lens substrate to approximately 1.46 on the outer side. This layer serves a dual purpose: firstly, it continues the broadband antireflection function, completing a smooth optical transition from the microcavity layer to the outermost low-refractive-index protective layer, ensuring high transmittance of the main visible light in the 460–780 nm range; secondly, it optically encapsulates and smoothly embeds the embedded spectral selective reflective layer into the entire film system, eliminating parasitic reflections that may occur due to refractive index mismatch when the top of the microcavity is in direct contact with the external environment. This ensures that its narrowband selection function can operate independently and accurately without interfering with the overall broadband antireflection effect.

[0061] The protective layer primarily provides durable physicochemical protection, and its structure is as follows:

[0062] Dense silicon dioxide layer: A dense, non-porous SiO2 film with a thickness of 20-30 nm is deposited by sputtering to fill and seal microscopic defects on the surface of the second gradient refractive index layer, providing an extremely smooth, chemically inert, and robust interface.

[0063] Diamond-like carbon film: A 3-5 μm thick diamond-like carbon film is deposited on a dense silica layer using plasma-enhanced chemical vapor deposition. The extremely high hardness and excellent chemical inertness of diamond-like carbon provide the ultimate mechanical protection against everyday scratches, abrasion and corrosion for the entire optical film.

[0064] To improve the waterproof and oil-repellent properties of lenses, a fluorosilane molecular layer can be fabricated on the surface of the diamond-like carbon film. This layer can be formed through vapor deposition to further reduce the surface energy and endow the film with excellent hydrophobic and oleophobic properties, thus achieving anti-fouling and easy-to-clean functions.

[0065] This embodiment provides a vision correction lens, comprising a lens substrate made of CR-39 resin with a refractive index of 1.60. The multifunctional optical thin film of this invention is prepared on the convex optical surface of the lens substrate using the following process:

[0066] S1 places the resin lens in a vacuum chamber and first performs argon plasma cleaning with parameters of 300W power, 0.3Pa pressure, and 5 minutes; then performs oxygen plasma activation treatment with parameters of 150W power, 0.5Pa pressure, and 3 minutes.

[0067] S2 employs reactive magnetron sputtering, using a titanium target in an atmosphere of mixed argon and oxygen (flow rate ratio Ar:O2=20:8sccm), with a chamber pressure of 0.25Pa, a sputtering power of 2.5kW, and a deposition time of 35 seconds, to form a dense titanium oxide bonding layer with a thickness of 15nm on the lens surface.

[0068] S3 uses a dual-target co-sputtering process with a titanium dioxide target and a silicon dioxide target. Under computer program control, within a total deposition time of 100 seconds, the power of the titanium dioxide target linearly decreases from 2.0 kW to 0.2 kW, while the power of the silicon dioxide target linearly increases from 0.2 kW to 1.8 kW. The argon flow rate is maintained at 30 sccm, and the chamber pressure is 0.2 Pa. This results in the deposition of a first-gradient refractive index layer with a refractive index that gradually changes from 2.02 to 1.79, with a physical thickness of 85 nm.

[0069] S4 Preparation of a bottom high-reflectivity multilayer film: Sputtering was performed by alternating titanium dioxide and silicon dioxide targets; 7 thin films with an optical thickness of λ / 4 were deposited with a design center wavelength of 430 nm, in the order of TiO2 (61.5 nm) / SiO2 (73.6 nm) / TiO2 / SiO2 / TiO2 / SiO2 / TiO2, with a total physical thickness of 754 nm;

[0070] Silica spacer layer: With the titanium oxide target off, a pure silicon dioxide layer with a thickness of 147 nm was deposited by sputtering using only a silicon dioxide target under an argon atmosphere (flow rate 30 sccm, pressure 0.2 Pa, power 2.0 kW). The optical thickness is 147 nm × 1.46 ≈ 214.6 nm, where 1.46 is the refractive index of SiO2.

[0071] Top high-reflectivity multilayer film: Continue alternating sputtering to deposit 5 thin films with an optical thickness of λ / 4, in the order of TiO2 (61.5nm) / SiO2 (73.6nm) / TiO2 / SiO2 / TiO2, with a total physical thickness of 429nm;

[0072] S5 again employs a dual-target co-sputtering process, controlling the titanium oxide target power to linearly decrease from 1.5kW to 0kW and the silicon dioxide target power to linearly increase from 0.5kW to 2.0kW within a total deposition time of 120 seconds, depositing a second-gradient refractive index layer with a refractive index that gradually changes from 1.81 to 1.47, with a physical thickness of 105nm.

[0073] S6 Dense Silica Layer: A dense silica layer with a thickness of 25 nm was deposited by sputtering a silica target at a power of 3.0 kW under an atmosphere of argon and a small amount of oxygen (Ar:O2=28:2sccm).

[0074] Diamond-like carbon film: A 4.2 μm thick diamond-like carbon film was deposited using plasma-enhanced chemical vapor deposition with methane and hydrogen as gas sources (CH4:H2=10:90sccm) under the conditions of 800W RF power, -150V substrate bias and 50Pa chamber pressure.

[0075] The final vision correction lens has the following multifunctional optical film from the substrate outwards: a 15nm TiO2 bonding layer, an 85nm thick first gradient refractive index layer, a 754nm thick bottom high-reflectivity multilayer film, a 147nm thick silicon dioxide spacer layer, a 429nm thick top high-reflectivity multilayer film, a 105nm thick second gradient refractive index layer, a 25nm dense silicon dioxide layer, and a 4.2μm diamond-like carbon film.

[0076] Example 2:

[0077] Unlike Example 1, S4 in this example is:

[0078] S4 bottom high-reflectivity multilayer film: With 440nm as the design center wavelength, 7 thin films with λ / 4 optical thickness are alternately sputtered and deposited; the order is: TiO2 (thickness about 63.2nm) / SiO2 (thickness about 75.3nm) / TiO2 / SiO2 / TiO2 / SiO2 / TiO2, with a total physical thickness of about 723nm;

[0079] Silica spacer layer: With the titanium oxide target off, a pure silicon dioxide layer is deposited under the same process conditions as in Example 1. The optical thickness is designed to be half of 440nm, i.e., 220nm. Based on the refractive index of SiO2 (n≈1.46), the physical thickness is approximately 151nm.

[0080] Top high-reflectivity multilayer film: Using the same design center wavelength of 440nm, continue to alternately sputter and deposit 5 thin films with an optical thickness of λ / 4, in the following order: TiO2 (thickness approximately 63.2nm) / SiO2 (thickness approximately 75.3nm) / TiO2 / SiO2 / TiO2, with a total physical thickness of approximately 428nm.

[0081] The final vision correction lens has the following optical films from the substrate outwards: a 15nm TiO2 bonding layer, an 85nm thick first gradient refractive index layer, a 723nm thick bottom high-reflectivity multilayer film, a 151nm thick silicon dioxide spacer layer, a 428nm thick top high-reflectivity multilayer film, a 105nm thick second gradient refractive index layer, a 25nm dense silicon dioxide layer, and a 4.2μm diamond-like carbon film.

[0082] Comparative Example 1:

[0083] Unlike Example 1, this comparative example omits the first and second gradient refractive index layers; the multifunctional optical thin film directly deposits an embedded spectrally selective reflective layer from the bonding layer outwards, followed by a direct deposition of the protective layer.

[0084] Comparative Example 2:

[0085] Unlike Example 1, this comparative example designs the optical thickness of the silicon dioxide spacer layer in the embedded spectrally selective reflective layer to be one-quarter of the design center wavelength (430nm), rather than one-half. The remaining film structure and process are the same as in Example 1.

[0086] Comparative Example 3:

[0087] Unlike Example 1, this comparative example designs the top and bottom high-reflectivity multilayer films in the embedded spectrally selective reflective layer to have the same number of layers and structure, so that their reflectivity to the target wavelength is basically symmetrical.

[0088] Performance verification:

[0089] The lenses of the examples and comparative examples were tested in accordance with GB10810.3-2006, GB / T 38120-2019, GB10810.1-2015 and industry regulations, and the data in Table 1 were obtained.

[0090] Table 1. Lens test results for the examples and comparative examples.

[0091]

[0092] Examples 1 and 2 simultaneously meet the dual high standards of average reflectance <0.8% in the 460~780nm range and average reflectance >30% in the 415~455nm range, while maintaining high transmittance of beneficial blue light, thus achieving high transmittance and strong protection.

[0093] After removing the first and second gradient refractive index layers in Comparative Example 1, the broadband reflectivity significantly increased to 1.95%, while the shielding band reflectivity plummeted to 15.2%. This demonstrates that the first and second gradient refractive index layers not only handle broadband antireflection themselves, but also eliminate parasitic reflections at the interface between the resonant cavity and the substrate / air through smooth embedding. They are crucial for ensuring the efficient operation of the resonant cavity. The absence of the first and second gradient refractive index layers leads to mutual inhibition of these two functions, resulting in overall performance degradation.

[0094] Comparative Example 2, after changing the cavity length to λ / 4, almost lost its reflectivity in the target wavelength band (415~455nm). This proves that an optical thickness of 1 / 2 of the target wavelength is a necessary condition for forming a sharp, high-reflectivity resonance peak, and is the physical basis for achieving precise narrowband selection.

[0095] In Comparative Example 3, after adopting a symmetrical cavity mirror, although the reflectivity was acceptable at 0° incidence, the reflectivity decreased more significantly at a large angle of 30°. This indicates that the asymmetrical design can more effectively couple the resonant light to the outside of the lens, improving angular stability, which is crucial for the consistent protection of the edge field of view of high curvature lenses.

[0096] All embodiments exhibit minimal performance degradation across both wide and narrow bands at a 30° incident angle, with a blue shift of only +2nm in the reflection peak, far superior to Comparative Examples 1 and 2. This demonstrates that the structure of the present invention inherently mitigates the performance degradation problem at large angles.

[0097] Although this application has been described in conjunction with specific features and embodiments, it is obvious that various modifications and combinations can be made thereto without departing from the spirit and scope of this application. Accordingly, this specification and drawings are merely exemplary illustrations of the application as defined herein, and are to be considered as covering any and all modifications, variations, combinations, or equivalents within the scope of this application. Clearly, those skilled in the art can make various alterations and modifications to this application without departing from its scope. Thus, if such modifications and modifications fall within the scope of this application and its equivalents, this application intends to include such modifications and modifications.

Claims

1. A multifunctional optical film for use in vision correction lenses, characterized in that, From the lens base outwards, the following are included: bonding layer; First gradient refractive index layer; Embedded spectrally selective reflective layer; The second gradient refractive index layer; and Protective layer; The refractive indices of the first gradient refractive index layer and the second gradient refractive index layer decrease continuously from the bonding layer toward the protective layer. The embedded spectrally selective reflective layer comprises a bottom high-reflectivity multilayer film, a silicon dioxide spacer layer, and a top high-reflectivity multilayer film stacked sequentially.

2. The multifunctional optical thin film according to claim 1, characterized in that, The bonding layer is made of titanium oxide and has a thickness of 10-20 nm.

3. The multifunctional optical thin film according to claim 1, characterized in that, Both the bottom high-reflectivity multilayer film and the top high-reflectivity multilayer film are composed of alternating layers of titanium oxide and silicon dioxide, and the total physical thickness of the bottom high-reflectivity multilayer film and the top high-reflectivity multilayer film is 500~1200nm.

4. The multifunctional optical thin film according to claim 3, characterized in that, The bottom high-reflectivity multilayer film has a higher reflectivity for the target wavelength than the top high-reflectivity multilayer film.

5. The multifunctional optical thin film according to claim 1, characterized in that, The optical thickness of the silicon dioxide spacer layer is 0.9 to 1.1 times half of any center wavelength in the range of 415 to 455 nm.

6. The multifunctional optical thin film according to claim 1, characterized in that, The first gradient refractive index layer and / or the second gradient refractive index layer are co-sputtered gradient composite layers of titanium oxide and silicon dioxide, and the total physical thickness of the first gradient refractive index layer and the second gradient refractive index layer is 100~300nm.

7. The multifunctional optical thin film according to claim 6, characterized in that, The refractive index of the first gradient refractive index layer gradually changes from 2.0±0.1 to 1.8±0.1; and / or, the refractive index of the second gradient refractive index layer gradually changes from 1.8±0.1 to 1.46±0.

1.

8. The multifunctional optical thin film according to claim 1, characterized in that, The protective layer comprises a dense silicon dioxide layer and a diamond-like carbon film stacked sequentially from the inside out. The physical thickness of the dense silicon dioxide layer is 20~30nm, and the physical thickness of the diamond-like carbon film is 3~5μm.

9. A vision correction lens, comprising a lens substrate, characterized in that, A multifunctional optical thin film according to any one of claims 1 to 8 is disposed on at least one optical surface of the lens substrate.

10. The vision correction lens according to claim 9, characterized in that, The lens substrate is made of resin.

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