Spectacle lens evaluation method and spectacle lens
The eyeglass lens evaluation method and anti-reflective coating with alternating layers enhance visibility by minimizing light reflection, addressing the challenge of obscured vision in twilight conditions.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- NIKON ESSILOR
- Filing Date
- 2025-11-05
- Publication Date
- 2026-05-21
AI Technical Summary
Existing eyeglass lenses with anti-reflective coatings struggle to maintain visibility of objects under various lighting conditions, particularly in twilight, due to light reflection from the wearer's skin entering the eye and obscuring the view.
A method for evaluating eyeglass lenses using the index P, calculated through a formula that considers reflectance and sensitivity of the lens and skin, to select lenses that enhance visibility by minimizing light reflection, and an anti-reflective coating with alternating high and low refractive index layers.
The method and coating design improve object visibility by reducing light reflection, making objects clearer to the wearer under different lighting conditions, with a preferred index P value of 82.0% or higher.
Smart Images
Figure JP2025038798_21052026_PF_FP_ABST
Abstract
Description
Methods for evaluating eyeglass lenses, eyeglass lenses
[0001] This disclosure relates to methods for evaluating eyeglass lenses. This disclosure also relates to eyeglass lenses themselves.
[0002] Various studies have been conducted on eyeglass lenses. For example, Patent Document 1 describes an eyeglass lens in which a low refractive index layer and a high refractive index layer are alternately laminated on a substrate as an anti-reflective coating.
[0003] International Publication No. 2021 / 060554
[0004] This disclosure relates to a method for evaluating spectacle lenses comprising a spectacle lens substrate having an eyeball-facing surface and an object-facing surface, and an anti-reflective coating disposed on the eyeball-facing surface of the spectacle lens substrate, wherein the index P is represented by formula (1) described later. ｂａｃｋ The present invention relates to an evaluation method for eyeglass lenses, which includes a step of calculating the index P. ｂａｃｋ However, over 80.0% of this is related to eyeglass lenses.
[0005] This is a cross-sectional view of one embodiment of an eyeglass lens to be evaluated in the eyeglass lens evaluation method disclosed herein.
[0006] The following describes in detail the method for evaluating spectacle lenses and the spectacle lenses themselves. The method for evaluating spectacle lenses requires the ability to assess the visibility of an object through a spectacle lens equipped with an anti-reflective coating on the eye-facing side under predetermined environmental conditions. In particular, when light reflected from the wearer's skin is reflected from the eye-facing side of the spectacle lens and enters the wearer's eye, the object may become difficult to see through the lens. The method for evaluating spectacle lenses under predetermined environmental conditions allows for the assessment of the visibility of an object through a spectacle lens equipped with an anti-reflective coating on the eye-facing side.
[0007] Furthermore, in eyeglass lenses, it is required that objects be easily visible through the lens positioned on the eye-facing side under twilight conditions. In particular, when light reflected from the wearer's skin is reflected from the eye-facing side of the eyeglass lens and enters the wearer's eye, objects may become difficult to see through the lens. The eyeglass lens of this disclosure makes objects easily visible through the lens positioned on the eye-facing side under twilight conditions.
[0008] In this disclosure, "~" is used to mean that the numbers before and after it are included as the lower and upper limits. Also, in this disclosure, unless otherwise specified, the refractive index is the refractive index at the e line.
[0009] <Method for Evaluating Eyeglass Lenses> The method for evaluating eyeglass lenses according to this disclosure comprises an eyeglass lens substrate having an eyeball-facing surface and an object-facing surface, and an anti-reflective coating disposed on the eyeball-facing surface of the eyeglass lens substrate. First, with reference to the drawings, the eyeglass lenses to be evaluated in the method for evaluating eyeglass lenses according to this disclosure will be described.
[0010] Figure 1 is a cross-sectional view of one embodiment of an eyeglass lens to be evaluated in the eyeglass lens evaluation method of this disclosure. The eyeglass lens 10 shown in Figure 1 includes, in this order, an eyeglass lens substrate 12, a primer layer 14, a hard coat layer 16, an anti-reflective film 18, and a water-repellent and oil-repellent layer 20. The eyeglass lens 10 includes the primer layer 14, the hard coat layer 16, and the water-repellent and oil-repellent layer 20, but the primer layer 14, the hard coat layer 16, and the water-repellent and oil-repellent layer 20 are optional components, and the eyeglass lens to be evaluated in the eyeglass lens evaluation method of this disclosure only needs to include an eyeglass lens substrate and an anti-reflective film. The anti-reflective film is disposed at least on the eye-ball side of the eyeglass lens substrate.
[0011] In the spectacle lens 10 shown in Figure 1, the anti-reflective coating 18 has, from the spectacle lens substrate 12 side, a first high refractive index layer 22H, a first low refractive index layer 22L, a second high refractive index layer 24H, a second low refractive index layer 24L, a third high refractive index layer 26H, a third low refractive index layer 26L, a fourth high refractive index layer 28H, and a fourth low refractive index layer 28L in this order. In Figure 1, the fourth low refractive index layer 28L is positioned furthest from the spectacle lens substrate 12 in the anti-reflective coating 18, but the layering order of the high refractive index layers and low refractive index layers may be changed so that the fourth high refractive index layer 28H is positioned furthest from the spectacle lens substrate 12. In Figure 1, the anti-reflective coating 18 has a total of eight layers of high refractive index and low refractive index layers, but this can be changed as appropriate. The total number of high refractive index and low refractive index layers can be, for example, two or more layers, preferably four or more layers, and may be six or more layers, or eight or more layers. There is no particular upper limit on the total number of high-refractive-index and low-refractive-index layers, but from a productivity standpoint, 14 layers or less is preferred, and 12 layers or less is more preferred.
[0012] In Figure 1, each layer is arranged on only one side of the spectacle lens substrate 12, but the primer layer 14, hard coat layer 16, anti-reflective film 18, and water- and oil-repellent layer 20 may be arranged on both sides of the spectacle lens substrate 12 in this order. In other words, the spectacle lens may have an anti-reflective film on both sides of the spectacle lens substrate. Also, in Figure 1, the anti-reflective film consists only of a low refractive index layer and a high refractive index layer, but in the spectacle lens of this disclosure, the anti-reflective film may include layers other than the low refractive index layer and the high refractive index layer (for example, an antistatic layer described later). Furthermore, the spectacle lens to be evaluated in the spectacle lens evaluation method may have the configuration described in the spectacle lens section later.
[0013] [Calculation Process] Here, as described above, in the method for evaluating eyeglass lenses of this disclosure, the index P is expressed by the following formula (1). ｂａｃｋ It includes a step for calculating (hereinafter also referred to as the "calculation step").
[0014]
[0015] In formula (1), R ＲｅｆR(λ) represents the reflectance of the surface on the ocular side of the sample excluding the antireflection film from the spectacle lens. ＡＲ R ＡＲ (λ) represents the reflectance of the surface on the antireflection film side of the spectacle lens. ｓｋｉｎ V(λ) represents the reflectance of the skin corresponding to the wavelength λ. ｐｓ S(λ) represents the sensitivity of the eye corresponding to the wavelength λ. Regarding the summation symbol, for example, regarding the first term in the numerator in the above formula (1), R Ｒｅｆ (λ), R ＡＲ (λ) and V ｐｓ (λ) means calculating the product of them every 1 nm from wavelength λ = 380 to 780 nm and adding up all the calculated values. Here, the exponent P ｂａｃｋ can be said to represent the degree of ease of viewing of the object to be improved by the antireflection film compared to the case without the antireflection film. Specifically, in the above formula (1), for the case without the antireflection film and the case with the antireflection film, the value obtained by multiplying the light reflected by the skin at each wavelength, the reflectance of the spectacle lens at each wavelength, and the sensitivity of the eye at each wavelength, and adding them up is calculated. The value obtained by the above addition takes into account the wavelength dependence of the reflectance of the skin, the reflectance of the spectacle lens, and the sensitivity of the eye, and it is considered that the light reflected by the skin of the spectacle wearer reflects the amount of light reflected on the ocular side of the spectacle lens and the amount of reflected light felt by the spectacle (spectacle lens) wearer when the light enters the wearer's eye. Therefore, the above exponent P ｂａｃｋ is considered to reflect the ease of viewing of the object through the spectacle lens having an actual antireflection film. Hereinafter, each parameter will be described.
[0016] As described above, R Ｒｅｆ(λ) represents the reflectance of the surface of the eye-facing side of the sample, excluding the anti-reflective coating from the spectacle lens, at wavelength λ. The reflectance of the eye-facing side of the sample (hereinafter simply referred to as "the sample surface") at wavelength λ is the reflectance of light incident from a direction tilted at 35° to the sample surface. In other words, the above reflectance is the reflectance of light incident from a direction tilted at 55° to the normal direction of the sample surface. Note that when light reflected by the skin of the spectacle wearer is reflected by the eye-facing side of the spectacle lens and incident on the wearer's eye, it is often incident from a direction tilted at 55° to the normal direction of the spectacle lens surface. The reflectance of the sample surface at wavelength λ may be measured with a spectrophotometer or determined by simulation. The reflectance of the sample surface at wavelength λ is determined in the range of wavelengths from 380 to 780 nm, at 1 nm intervals starting from exactly 380 nm.
[0017] As mentioned above, R ＡＲ (λ) represents the reflectance of the surface on the anti-reflective coating side of the spectacle lens at wavelength λ. ＡＲ (λ) is the same as R Ｒｅｆ Except for using spectacle lenses instead of the sample used when determining (λ), the above R Ｒｅｆ It is determined in the same way as (λ). That is, the reflectance of light incident from a direction tilted at 35° to the surface of the sample is determined in 1 nm increments starting from exactly 380 nm, in the wavelength range of 380 to 780 nm.
[0018] As mentioned above, R ｓｋｉｎ (λ) represents the skin reflectance corresponding to the wavelength λ. In this disclosure, R ｓｋｉｎ(λ) is the average spectrum obtained by averaging the skin reflectance of 100 people. Specifically, the average spectrum is obtained by referring to the human skin reflectance described in Cooksey, C., Allen, D. and Tsai, B. (2017), Reference Data Set of Human Skin Reflectance, Journal of Research (NIST JRES), National Institute of Standards and Technology, Gaithersburg, MD (hereinafter also simply referred to as "the Reference"). In the data described in the above Reference, spectra are described every 3 nm, but in this disclosure, the above 3 nm data are linearly interpolated to obtain the average spectrum every 1 nm. The specific values of skin reflectance every 1 nm corresponding to wavelength λ in this disclosure are shown in Tables 1 to 4 below. Note that the skin reflectance described in Tables 1 to 4 below is a parameter expressed in the range of 0 to 1.
[0019]
[0020]
[0021]
[0022]
[0023] As mentioned above, V ｐｓ (λ) represents the sensitivity of the eye corresponding to the wavelength λ. In this disclosure, V ｐｓ (λ) is the value calculated by the following formula (V1): (V1) V ｐｓ (λ) = mV(λ) + (1-m)V'(λ) In the above equation (V1), V(λ) represents the sensitivity of the eye under photopic conditions corresponding to wavelength λ. In the above equation (V1), V'(λ) represents the sensitivity of the eye under scotopic conditions corresponding to wavelength λ. In the above equation (V1), m represents a real number between 0 and 1. That is, in the above equation (V1), the sensitivity of the eye from photopic conditions to scotopic conditions can be approximately expressed by the value of m. When m is 1, V ｐｓ (λ) represents the sensitivity of the eye under photopic conditions, and when m is 0, Vｐｓ (λ) represents the sensitivity of the eye under scotopic conditions. When m is 0.5, it can be said to represent the sensitivity of the eye under intermediate conditions between photopic and scotopic conditions (so-called twilight conditions). m may take values other than 0, 0.5, and 1. The above value of m may be changed as appropriate depending on the environment (brightness) in which the spectacle lens is used. For example, m may be a value of 0.1, 0.2, 0.3, 0.4, 0.6, 0.7, 0.8, and 0.9.
[0024] Below, V ｐｓ Tables 5 to 11 below show the specific values for (λ) when m is 1 (i.e., V(λ) in equation (V1) above) and when m is 0 (i.e., V'(λ) in equation (V1) above). In addition, Tables 5 to 11 below also show the specific values when m is 0.5. For convenience, the value of V when m is 0.5 is shown below. ｐｓ (λ) is V in Tables 5 to 11 below. ｍｅｓ It is written as (λ).
[0025]
[0026]
[0027]
[0028]
[0029]
[0030]
[0031]
[0032] Note that the exponent P represented by the above formula (1) is ｂａｃｋ It takes values between 0 and 1. The exponent P ｂａｃｋ The closer the value of P is to 1, the less light reflected by the skin is reflected by the anti-reflective coating, and the easier it is to see objects through eyeglass lenses with an anti-reflective coating. Here, for example, the above index P for multiple eyeglass lenses... ｂａｃｋ Calculate the values of each, and exponent P ｂａｃｋ The values are compared and evaluated, and the higher exponent P ｂａｃｋBy selecting eyeglass lenses that exhibit this value, it is possible to provide eyeglass lenses that make objects appear clearer to the wearer of the eyeglasses.
[0033] Furthermore, for multiple eyeglass lenses, the above V ｐｓ While changing the value of m in the above formula (V1) when calculating (λ), the above exponent P ｂａｃｋ Calculate the values of each, and exponent P ｂａｃｋ The values of these can be compared and evaluated. As mentioned above, when m is close to 1, the index P indicates the visibility of the object under conditions close to photopic conditions. ｂａｃｋ The value of is calculated, and if m is close to 0, then the index P indicates the visibility of the object under conditions close to scotopic conditions. ｂａｃｋ The value of the exponent P can be calculated. ｂａｃｋ By calculating the value of m by varying the value of m, it is possible to compare the visibility of objects under photopic conditions, under scotopic conditions, and under intermediate conditions between photopic and scotopic conditions, for each type of spectacle lens.
[0034] Note that the above index P ｂａｃｋ The value may be multiplied by a predetermined coefficient. The predetermined coefficient can be set as appropriate, but examples include 0.01, 0.1, 10, 100, 1000, and 10000.
[0035] The calculation step in the above method for evaluating eyeglass lenses may be performed by a processing device. Examples of processing devices include well-known computers.
[0036] <Eyeglass Lens> The eyeglass lens of this disclosure comprises an eyeglass lens substrate having an eyeball-facing surface and an object-facing surface, and an anti-reflective coating disposed on the eyeball-facing surface of the eyeglass lens substrate. An example of an embodiment of the eyeglass lens is the same as the example of an eyeglass lens to be evaluated in the evaluation method of the eyeglass lens of this disclosure (Figure 1), and therefore its description is omitted. Here, the eyeglass lens of this disclosure is represented by the index P expressed by the following formula (2). ｂａｃｋ However, the percentage is over 80.0%.
[0037]
[0038] In formula (2), R Ｒｅｆ (λ) represents the reflectance of the surface on the eye-facing side of the sample, which is the same as the spectacle lens with the anti-reflective coating removed, at wavelength λ. ＡＲ (λ) represents the reflectance of the surface of the anti-reflective coating side of the spectacle lens at wavelength λ. ｓｋｉｎ (λ) represents the skin reflectance corresponding to the wavelength λ. ｍｅｓ (λ) represents the sensitivity of the eye under twilight conditions corresponding to the wavelength λ. R in equation (2) Ｒｅｆ (λ), R ＡＲ (λ) and R ｓｋｉｎ The method for determining (λ) is R in equation (1) described above in the method for evaluating spectacle lenses of this disclosure. Ｒｅｆ (λ), R ＡＲ (λ) and R ｓｋｉｎ The method for finding (λ) is the same as for each of them. Also, V in equation (2) ｍｅｓ (λ) is V in equation (1) above. ｐｓ This is the value when m is 0.5 in the above formula (V1) when calculating (λ). Therefore, the specific value corresponding to the wavelength λ is (V ｍｅｓ (λ) is as described in Tables 5 to 11 above.
[0039] In the eyeglass lens of this disclosure, the exponent P represented by the above formula (2) is ｂａｃｋ Since it takes values between 0 and 1, when calculating the percentage value, the exponent P ｂａｃｋ Multiply by 100. In the spectacle lens of this disclosure, the exponent P ｂａｃｋ The percentage is preferably 82.0% or higher, more preferably 84.0% or higher, and even more preferably 86.0% or higher. (Index P) ｂａｃｋ It is 100.0% or less, often 95.0% or less, and may also be 90.0% or less.
[0040] The configuration of the eyeglass lens of this disclosure, and the configurations that the eyeglass lens of this disclosure may have, will be described below.
[0041] [Eyeglass Lens Substrate] The eyeglass lens substrate is a component that supports the anti-reflective coating. The type of eyeglass lens substrate is not particularly limited, and ordinary eyeglass lens substrates made of plastic, inorganic glass, etc. are examples, but plastic eyeglass lens substrates are preferred in terms of their ease of handling. The type of plastic (so-called resin) contained in the plastic eyeglass lens substrate is not particularly limited, but examples include (meth)acrylic acid ester resin, thiourethane resin, allyl resin, episulfide resin, polycarbonate, urethane resin, polyester, polystyrene, polyethersulfone, poly-methylpentene-1, and diethylene glycol bisallyl carbonate resin (CR-39). Among these, thiourethane resin, episulfide resin, or diethylene glycol bisallyl carbonate resin is preferred.
[0042] The type of plastic spectacle lens base material is not particularly limited, but examples include those having convex and concave surfaces. More specifically, examples include finished lenses in which both the convex and concave surfaces are optically finished and molded to the desired prescription, semi-finished lenses in which only the convex surface is finished as an optical surface (spherical, rotationally symmetric aspherical, progressive, etc.), and semi-finished lenses in which the concave surface is processed and polished according to the wearer's prescription.
[0043] The thickness of the plastic spectacle lens substrate is not particularly limited, but for ease of handling, it is often around 1 to 30 mm. The refractive index of the plastic spectacle lens substrate is not particularly limited, but it is often 1.50 or higher, preferably 1.60 to 1.80, and more preferably 1.60 to 1.74. The plastic spectacle lens substrate does not have to be colorless as long as it is light-transmitting, and may contain ultraviolet absorbers and dyes that absorb specific wavelengths from the ultraviolet to infrared regions. The plastic spectacle lens substrate may also contain additives such as bluing agents, light stabilizers, and antioxidants.
[0044] [Primer Layer] The spectacle lens of this disclosure may include a primer layer. The primer layer is preferably placed between the spectacle lens substrate and the hard coat layer. When the primer layer is placed between the spectacle lens substrate and the hard coat layer, it improves the adhesion of the hard coat layer to the substrate and improves the strength of the spectacle lens with an anti-reflective coating on the hard coat layer against static load or impact. The material constituting the primer layer is not particularly limited, and known materials can be used, for example, mainly resins are used. The type of resin used is not particularly limited, and examples include polyurethane resins, epoxy resins, phenolic resins, polyimide resins, polyester resins, bismaleimide resins, and polyolefin resins, with polyurethane resins being preferred. The primer layer may contain other components other than the above resins. Other components include, for example, oxide nanoparticles of at least one metal selected from Si, Al, Sn, Sb, Ta, Ce, La, Fe, Zn, W, Zr, In, and Ti, or composite oxide nanoparticles thereof, hydrolyzable silicon compounds and / or hydrolyzable condensates thereof, conductive fillers, and surfactants.
[0045] The method for forming the primer layer is not particularly limited, and known methods can be employed. For example, a method can be used in which a primer layer-forming composition containing a predetermined resin is applied to an eyeglass lens substrate, and a curing treatment is performed as necessary to form the primer layer. The method for applying the primer layer-forming composition is not particularly limited, and an example is the method described later, which involves applying a hard coat layer-forming composition to an eyeglass lens substrate. The thickness of the primer layer is not particularly limited, but 0.3 to 2 μm is preferred.
[0046] [Hard Coat Layer] The spectacle lenses of this disclosure may include a hard coat layer. The hard coat layer is preferably placed between the spectacle lens substrate and the anti-reflective film, and is a layer that provides scratch resistance to the substrate. The hard coat layer is preferably one that exhibits a hardness of "H" or higher in pencil hardness as specified by the test method defined in the international standard ISO 15184 and the Japanese Industrial Standard JIS K5600 which was created based on this international standard.
[0047] As the hard coat layer, known hard coat layers can be used, such as organic hard coat layers, inorganic hard coat layers, and organic-inorganic hybrid hard coat layers. For example, in the field of eyeglass lenses, organic-inorganic hybrid hard coat layers are commonly used.
[0048] The hard coat layer preferably contains polymers of polymerizable monomers (polymers obtained by polymerizing polymerizable monomers) and / or condensates of hydrolyzable organosilicon compounds. The polymerizable monomers are not particularly limited, but examples include (meth)acrylates having at least one group selected from the group consisting of phosphate groups and sulfonic acid groups, silsesquioxanes having radical polymerizable groups, polyfunctional acrylates, compounds having multiple epoxy groups, and silsesquioxane compounds having oxetanyl groups. (Meth)acrylate means acrylate or methacrylate. The hydrolyzable organosilicon compounds are not particularly limited, but examples include organosilicon compounds having epoxy groups.
[0049] Furthermore, the hard coat layer may contain inorganic components such as metal oxide fine particles. The type of metal oxide fine particles is not particularly limited, and known metal oxide fine particles can be used. Examples of metal oxide fine particles include oxide fine particles of at least one metal selected from Si, Al, Sn, Sb, Ta, Ce, La, Fe, Zn, W, Zr, In, and Ti. Among these, in terms of ease of handling, metal oxide fine particles containing Si oxide (silicon oxide fine particles), oxide fine particles containing Sn (tin oxide fine particles), oxide fine particles containing Zr (zirconium oxide fine particles), or oxide fine particles containing Ti (titanium oxide fine particles) are preferred. Note that the metal oxide fine particles may contain only one type of metal (metal atom) as exemplified above, or may contain two or more types of metals (metal atoms). Although Si (silicon) is sometimes classified as a metalloid, in this disclosure, Si is included as a metal.
[0050] The hard coat layer is preferably a layer formed using a hard coat layer forming composition containing a polymerizable monomer. In addition to the polymerizable monomer, the hard coat layer forming composition may also contain the above-mentioned metal oxide fine particles, other components, and a solvent. Examples of other components include radical polymerization initiators, cationic polymerization initiators, and curing catalysts. Other components may also include various additives that are added as needed, such as UV absorbers, anti-aging agents, coating modifiers, light stabilizers, antioxidants, color inhibitors, dyes, fillers, and internal release agents. The solvent may be water or an organic solvent. The type of organic solvent is not particularly limited, and examples include alcohol-based solvents, ketone-based solvents, ether-based solvents, ester-based solvents, hydrocarbon-based solvents, halogenated hydrocarbon-based solvents, amide-based solvents, sulfone-based solvents, and sulfoxide-based solvents.
[0051] A method for forming a hard coat layer using a hard coat layer forming composition includes applying the hard coat layer forming composition onto an eyeglass lens substrate (or onto a primer layer) to form a coating film, and then performing a curing treatment such as light irradiation and heat treatment on the coating film. The curing treatment may involve either light irradiation or heat treatment, or both. If both are performed, they may be performed simultaneously, or one may be performed before the other. Furthermore, after forming the coating film, a drying treatment such as heat treatment may be performed as needed to remove the solvent from the coating film.
[0052] The method for applying the hard coat layer-forming composition is not particularly limited and includes known methods (e.g., dipping coat method, spin coat method, spray coat method, inkjet coat method, and flow coat method). The thickness of the formed coating film is not particularly limited and is appropriately selected to achieve a predetermined hard coat layer thickness.
[0053] The conditions for the light irradiation treatment are not particularly limited, and suitable conditions are selected depending on the type of polymerization initiator used. The type of light used for irradiation is not particularly limited, but examples include ultraviolet light and visible light. Examples of light sources include high-pressure mercury lamps. The cumulative light intensity during irradiation is not particularly limited, but in terms of productivity and curability of the coating film, it should be 100 to 3000 mJ / cm². ２ Preferably, 100 to 2000 mJ / cm² ２ This is more preferable. The heat treatment conditions are not particularly limited, and the optimal conditions are selected depending on the type of polymerization initiator used. The heating temperature is preferably 30 to 100°C, and the heating time is preferably 5 to 360 minutes.
[0054] The thickness of the hard coat layer is not particularly limited, but is preferably 1 μm or more, more preferably 3 μm or more, and even more preferably 10 μm or more. The upper limit of the thickness can be, for example, 30 μm or less. The above thickness is the average thickness, and the measurement method involves measuring the thickness of any five points on the hard coat layer and calculating the arithmetic mean of these measurements.
[0055] The hard coat layer may also contain additives such as bluing agents, light stabilizers, and antioxidants.
[0056] [Anti-reflective coating] The spectacle lens of this disclosure includes an anti-reflective coating. In the spectacle lens of this disclosure, the anti-reflective coating is disposed at least on the surface of the spectacle lens substrate that faces the eyeball. The anti-reflective coating is a layer that has the function of preventing the reflection of incident light. Specifically, an embodiment is provided that has low reflectivity (broadband low reflectivity) over the entire visible region from 380 to 780 nm.
[0057] The anti-reflective coating preferably includes a high refractive index layer and a low refractive index layer. In the anti-reflective coating, it is preferable that the high refractive index layer and the low refractive index layer are arranged alternately. That is, when the anti-reflective coating includes two high refractive index layers and two low refractive index layers, it is preferable that a low refractive index layer is placed between two high refractive index layers, and a high refractive index layer is placed between two low refractive index layers. Furthermore, as will be described later, an antistatic layer (for example, SnO) may be placed between the high refractive index layer and the low refractive index layer. ２ A layer or ITO layer may be present. ITO (Indium Tin Oxide) is indium tin oxide, and indium oxide (In ２ O ３ ) and tin oxide (SnO ２ It is a mixture of ). When the anti-reflective coating includes a high refractive index layer and a low refractive index layer, the total number of layers of the high refractive index layer and the low refractive index layer is preferably 4 or more, may be 6 or more, may be 8 or more, or may be 10 or more. When the anti-reflective coating includes a high refractive index layer and a low refractive index layer, the total number of layers of the high refractive index layer and the low refractive index layer is often 20 or less, may be 16 or less, or may be 12 or less.
[0058] As the high refractive index layer, a layer with a refractive index of 1.60 or higher is preferred. The high refractive index layer preferably contains at least one oxide selected from the group consisting of titanium, zirconium, aluminum, niobium, tantalum, and lanthanum. In particular, the high refractive index layer contains titanium dioxide (TiO2). ２ ), zirconium dioxide (ZrO ２), and tantalum pentoxide (Ta ２ O ５ It is preferable to include at least one selected from the group consisting of ), and more preferably to include zirconium dioxide. The high refractive index layer may contain two or more materials.
[0059] As the low refractive index layer, a layer with a refractive index of less than 1.60 is preferred. The low refractive index layer preferably contains at least one selected from the group consisting of silicon oxide, calcium fluoride, and magnesium fluoride. In particular, the low refractive index layer contains silicon dioxide (SiO₂). ２ It is preferable that it contains ). The low refractive index layer may contain two or more materials.
[0060] The total number of high-refractive-index layers and low-refractive-index layers in the anti-reflective coating, and its preferred configuration, are as described above.
[0061] In the anti-reflective coating, the layer located closest to the spectacle lens substrate may be a low refractive index layer or a high refractive index layer.
[0062] For example, the thickness of the high refractive index layer is preferably 5 to 200 nm, more preferably 5 to 150 nm, and even more preferably 8 to 100 nm. The thickness of the low refractive index layer is preferably 10 to 500 nm, more preferably 15 to 450 nm, and even more preferably 20 to 200 nm.
[0063] The following are examples of preferred embodiments of the anti-reflective coating. In an embodiment (embodiment 1) in which the anti-reflective coating is composed of a first high refractive index layer, a first low refractive index layer, a second high refractive index layer, a second low refractive index layer, a third high refractive index layer, a third low refractive index layer, a fourth high refractive index layer, and a fourth low refractive index layer, in order from the spectacle lens substrate side, the following embodiments are preferred for each layer. First high refractive index layer material: ZrO ２ Thickness: 5-15 nm First low refractive index layer material: SiO ２ Thickness: 40-60 nm Second high refractive index layer material: ZrO ２ Thickness: 10-20 nm Second low refractive index layer material: SiO ２ Thickness: 100-450 nm Third high refractive index layer material: ZrO ２Thickness: 5-15 nm Third low refractive index layer material: SiO ２ Thickness: 20-40 nm Fourth high refractive index layer material: ZrO ２ Thickness: 40-100 nm Fourth low refractive index layer material: SiO ２ Thickness: 70-110 nm. In addition, an antistatic layer (material: SnO) is placed between the fourth high refractive index layer and the fourth low refractive index layer. ２ It is also preferable that a layer with a thickness of 3 to 15 nm be placed therein.
[0064] In an embodiment (embodiment 2) where the anti-reflective coating is composed of a first high refractive index layer, a first low refractive index layer, and a second high refractive index layer and a second low refractive index layer in that order from the substrate side, the following embodiments are preferred for each layer. First high refractive index layer material: ZrO ２ Thickness: 10-50 nm First low refractive index layer material: SiO ２ Thickness: 10-30 nm Second high refractive index layer material: ZrO ２ Thickness: 60-100 nm Second low refractive index layer material: SiO ２ Thickness: 60-100 nm
[0065] The method for manufacturing the anti-reflective coating is not particularly limited, but examples include vacuum deposition, sputtering, ion plating, ion beam assist, and dry methods such as CVD.
[0066] In addition to the high refractive index layer and low refractive index layer mentioned above, the anti-reflective coating also contains SnO ２ It may further include a layer or an ITO layer. SnO ２ The layer and the ITO layer can function as an antistatic layer. SnO in the anti-reflective film ２ The placement of the layers and the ITO layer is not particularly limited and may be between the high-refractive-index layer and the low-refractive-index layer described above. ２ The thickness of the layer or ITO layer can be set as appropriate, but is preferably 3 to 20 nm, and more preferably 3 to 10 nm. Furthermore, when an antistatic layer is provided in the above embodiment 1, it is preferable to provide the antistatic layer between the fourth high refractive index layer and the fourth low refractive index layer, and the preferred material is SnO ２ The preferred thickness is 3 to 10 nm.
[0067] [Water- and oil-repellent layer] The eyeglass lens of this disclosure may include a water- and oil-repellent layer. In particular, it is preferable that the eyeglass lens has a water- and oil-repellent layer as its outermost layer. The water- and oil-repellent layer reduces the surface energy of the eyeglass lens, improves the stain-prevention function of the eyeglass lens, and improves the slipperiness of the surface of the eyeglass lens, thereby improving the abrasion resistance of the eyeglass lens.
[0068] The materials constituting the water-repellent and oil-repellent layer are not particularly limited, and examples include fluorine-containing compounds (compounds containing fluorine atoms) and silicon-containing compounds (compounds containing silicon atoms). In particular, the water-repellent and oil-repellent layer preferably contains a fluorine-containing compound, and more preferably contains at least one selected from the group consisting of fluorine-substituted alkyl group-containing organosilicon compounds, their hydrolysates, and their hydrolyzed condensates. The materials constituting the water-repellent and oil-repellent layer may be used individually or in combination of two or more.
[0069] A fluorine-substituted alkyl group-containing organosilicon compound is an organosilicon compound containing an alkyl group in which some or all of the hydrogen atoms are substituted with fluorine atoms, and which has a hydrolyzable group. Here, a hydrolyzable group is a group that is directly bonded to a silicon atom and can proceed with hydrolysis and condensation reactions, and examples include alkoxy groups, halogen atoms, acyloxy groups, alkenyloxy groups, and isocyanate groups. Note that if multiple hydrolyzable groups are directly bonded to a single silicon atom, they may be the same or different.
[0070] A hydrolysate of a fluorine-substituted alkyl group-containing organosilicon compound refers to a compound obtained by hydrolysis of the hydrolyzable groups in the fluorine-substituted alkyl group-containing organosilicon compound. The hydrolysate may be a complete hydrolysate (where all hydrolyzable groups are hydrolyzed) or a partial hydrolysate (where only some hydrolyzable groups are hydrolyzed). In other words, the hydrolysate may be a complete hydrolysate, a partial hydrolysate, or a mixture thereof. A hydrolysis condensate of a fluorine-substituted alkyl group-containing organosilicon compound refers to a compound obtained by hydrolysis of the hydrolyzable groups in the fluorine-substituted alkyl group-containing organosilicon compound and condensing the resulting hydrolysates. The hydrolysis condensate may be a complete hydrolysis condensate (where all hydrolyzable groups are hydrolyzed and all hydrolyzates are condensed) or a partial hydrolysis condensate (where some hydrolyzable groups are hydrolyzed and some hydrolyzates are condensed). In other words, the hydrolysis condensate may be a complete hydrolysis condensate, a partial hydrolysis condensate, or a mixture thereof.
[0071] The method for forming the water-repellent and oil-repellent layer is not particularly limited and can be arbitrarily selected depending on the materials used, desired performance, or thickness. For example, a method in which a water-repellent and oil-repellent layer-forming composition containing a fluorine-substituted alkyl group-containing organosilicon compound is coated onto a substrate and cured as necessary, and a dry method are mentioned. Examples of coating methods include dipping coat, roll coat, bar coat, spin coat, spray coat, die coat, and gravure coat. Examples of curing treatments include light irradiation, heat treatment, and steam contact treatment. Steam contact treatment is, for example, a treatment in which the material is brought into contact with air whose humidity is controlled to 50-90% RH. The above curing treatments may be carried out in combination. An example of a dry method is the same as that for the anti-reflective film described above.
[0072] The thickness of the water-repellent and oil-repellent layer on eyeglass lenses is not particularly limited, but 5 to 35 nm is preferred. If the thickness is within the above range, the eyeglass lenses will have excellent water-repellent and oil-repellent properties.
[0073] <Use> The spectacle lens evaluated by the method for evaluating spectacle lenses of the present disclosure, and the spectacle lens of the present disclosure are suitably used as lenses for spectacles. Examples of spectacles include spectacles having a known spectacle frame and spectacle lenses. Examples of spectacle frames include those having a pair of lens frames on which right-eye and left-eye spectacle lenses are respectively mounted, and temples for hanging the spectacle frame on the ears of the wearer.
[0074] Hereinafter, the above embodiment will be described in more detail with reference to examples and comparative examples, but the present disclosure is not limited by these examples.
[0075] <Simulation and Evaluation> The characteristics of the spectacle lenses of each example were evaluated by software simulation. More specifically, the spectacle lenses of the configurations of each example shown below were constructed on software (optical thin-film design software ThinFilmView (Nary Software, v3.31), hereinafter also referred to as "TFV"), and the index P represented by the above formula (2) ｂａｃｋ was calculated. That is, the value of the index P represented by the above formula (1) when m in V ｐｓ (λ) in the above formula (1) is 0.5 was calculated. It should be noted that air is assumed to exist on the surface of the spectacle lens opposite to the substrate side, and the refractive index of air was calculated as 1.00. ｂａｃｋ
[0076] In the above simulation, the spectacle lenses having the configurations shown in Table 12 in the following stage were constructed on TFV. The refractive index of the substrate is the refractive index at 507 nm. Also, the refractive indices of ZrO ２ , SiO ２ and SnO ２ at 507 nm were set as follows. ・ZrO ２ : 2.01 ・SiO ２ : 1.47 ・SnO ２ : 1.85
[0077] Next, the above calculation process was performed according to the method described above. Specifically, first, for the spectacle lens having the above configuration, the reflectance when light is incident from a direction 55° with respect to the normal direction of the surface was obtained for each wavelength of 1 nm, and was designated as R ＡＲ (λ). Further, in the spectacle lens in a state without an antireflection film, R ＡＲ (λ) was obtained in the same manner as R Ｒｅｆ (λ). Note that the specific values of R ｓｋｉｎ (λ) and V ｍｅｓ (λ) are as shown in the above-described table. In the following Table 12, the values obtained by multiplying the calculated value of the exponent P ｂａｃｋ by 100 and expressing them as percentages are shown.
[0078] Furthermore, spectacle lenses having the same configuration as above were manufactured, and three subjects were asked to evaluate the ease of viewing an object through the spectacle lenses. More specifically, an antireflection film having the configuration shown in Table 12 below was formed on a spectacle lens substrate having a plano-convex lens shape with a refractive index of 1.60, and each spectacle lens was obtained. Each of the obtained spectacle lenses was processed so that the plane side of the plano-convex lens became the side facing the eyeball, and glasses were obtained. The obtained glasses were put on three subjects, and under the condition that natural light is incident from a direction approximately 35° with respect to the plane of the plano-convex lens and under the condition of twilight vision, it was evaluated whether reflection from the skin was observed or not. The evaluation criteria are as follows. In practice, from the viewpoint of making the object easier to see through the spectacle lens, an A evaluation is preferable. The evaluation results are shown in the "Evaluation of Actual Lens" column in the table described later. ・A: Almost no reflection from the skin is noticed. ・B: It is easily noticed that there is reflection from the skin. ・C: The reflection from the skin is large
[0079]
[0080] From the results shown in Table 12, it was confirmed that when the value of the exponent P ｂａｃｋ represented by the formula (2) is large, the reflection from the skin decreases and the object becomes easier to see. That is, by the evaluation method of the spectacle lens of the present disclosure, the ease of viewing an object through the spectacle lens can be evaluated. Note that the exponent P ｂａｃｋ represented by the formula (1)Even when using the value of , it is easy to understand that the clarity of an object seen through the spectacle lens can be evaluated. Furthermore, in the spectacle lens of this disclosure, the index P expressed by equation (2) is used. ｂａｃｋ When the value was 80.0% or higher, it was confirmed that objects were easily visible through spectacle lenses under twilight conditions.
Claims
1. A method for evaluating an eyeglass lens comprising an eyeglass lens substrate having an eyeball-facing surface and an object-facing surface, and an anti-reflective coating disposed on the eyeball-facing surface of the eyeglass lens substrate, wherein the index P is represented by the following formula (1). ｂａｃｋ A method for evaluating eyeglass lenses, comprising a step of calculating [a certain value]. In formula (1), R Ｒｅｆ (λ) represents the reflectance of the surface on the eye-facing side of the sample, excluding the anti-reflective coating from the spectacle lens, at wavelength λ. ＡＲ (λ) represents the reflectance of the surface of the spectacle lens on the side with the anti-reflective coating at wavelength λ. ｓｋｉｎ (λ) represents the skin reflectance corresponding to the wavelength λ. ｐｓ (λ) represents the sensitivity of the eye to the wavelength λ.
2. In formula (1) above, V ｐｓ The method for evaluating spectacle lenses according to claim 1, wherein (λ) represents the sensitivity of the eye under twilight conditions corresponding to the wavelength λ.
3. A spectacle lens comprising a spectacle lens substrate having a surface on the eyeball side and a surface on the object side, and an antireflection film disposed on the surface on the eyeball side of the spectacle lens substrate, the index P represented by the following formula (2) ｂａｃｋ is 80.0% or more, the spectacle lens. In formula (2), R Ｒｅｆ (λ) represents the reflectance of the surface on the eyeball side of the sample excluding the antireflection film from the spectacle lens at wavelength λ. R ＡＲ (λ) represents the reflectance of the surface on the antireflection film side of the spectacle lens at wavelength λ. R ｓｋｉｎ (λ) represents the reflectance of the skin corresponding to wavelength λ. V ｍｅｓ (λ) represents the sensitivity of the eye under mesopic conditions corresponding to wavelength λ.