Optical article having a very low reflectance in the visible region and the near-infrared region

Abstract

The present invention provides an optical article comprising a transparent substrate having a front principal surface and a rear principal surface, at least one of the principal surfaces being coated with a multilayer interference coating comprising a stack of at least one high refractive index layer (HI) having a refractive index of 1.55 or more and at least one low refractive index layer (LI) having a refractive index less than 1.55, wherein the multilayer interference coating has an average reflectance (R ) of 2.9% or less, preferably 2.6%, at an angle of incidence of 45° or less for wavelengths in the range from 445 nm to a predetermined maximum wavelength of 1185 nm or more. m(445-≧1185 ))

Description

Technical Field

[0001] The present invention relates to an optical article including a multilayer interference coating, particularly an antireflection coating that strongly reduces reflection for wavelengths in both the visible region and the near-infrared (NIR) region, i.e., in the range of about 400 to 1200 nm, preferably 400 to 1000 nm. The optical article can particularly be an ophthalmic lens such as an eyeglass lens.

[0002] The present invention also relates to an optical device including the optical article and being suitable for forming, for example, an augmented reality device, a virtual reality device, or an eye-tracking device.

Background Art

[0003] The NIR range is generally used for the light that illuminates the eye for the purpose of eye tracking, because while NIR light is invisible to the user, the contrast of the pupil becomes very good, thereby enabling high precision and high reliability in the measurement of the line-of-sight direction or eye movement or any other measurement related to the size and position of the pupil, the corneal surface, the lens surface, the eye reflection on the eyelid, etc.

[0004] Such measurements can be performed through a specific optical device including a deep red and NIR light source and a video camera in addition to an ophthalmic lens.

[0005] However, when a deep red and NIR light source sends light toward the eyes of a user wearing such a device, multiple reflections occur on the surface of the ophthalmic lens. Such multiple reflections generate noise for the detector of the camera, making it impossible to properly locate the pupil.

[0006] Therefore, it is necessary to limit the reflection of deep red and NIR light on the ophthalmic lens.

[0007] In addition, due to the geometry settings of such optical devices intended to be used in new digital applications such as, for example, augmented reality (AR) or virtual reality (VR), NIR performance is particularly important at high incident angles, typically above 45°.

[0008] Furthermore, restricting reflection in the visible region in the range of 380 nm to 780 nm is also important for the comfort of the wearer of the ophthalmic lens.

[0009] Typical anti-reflection coatings on markings do not have a large wavelength broadband in the range of 400 - 1200 nm, preferably 400 - 1000 nm. In particular, they do not enable very low reflection at wavelengths in the range of 400 - 1200 nm, preferably 400 - 1000 nm, especially at high incident angles such as above 35°.

[0010] Therefore, there is a need to provide a new interference coating having very good anti-reflection properties in both the visible region and the NIR region at any incident angle (e.g., 0° - 60°).

[0011] There is also a need to provide a new interference coating that has, regardless of the incident angle, preferably both robustness properties and an aesthetic appearance (i.e., achromatic color).

Summary of the Invention

Problems to be Solved by the Invention

[0012] Therefore, an object of the present invention is to develop a transparent optical article, particularly an ophthalmic lens such as an eyeglass lens, which includes a substrate of mineral or organic glass including at least an interference coating, such as an anti-reflection coating, wherein the anti-reflection coating has very good anti-reflection performance in the visible region while also having very low reflection in the near-infrared region, and to do so without sacrificing the economic and / or industrial feasibility of its production.

Means for Solving the Problem

[0013] Accordingly, the present invention provides an optical article including a transparent substrate having a front main surface and a rear main surface, wherein at least one of the main surfaces is coated with a multilayer interference coating (particularly a multilayer antireflection coating) including a laminate of at least one high refractive index layer (HI) having a refractive index of 1.55 or more and at least one low refractive index layer (LI) having a refractive index of less than 1.55, and the multilayer interference coating has an average reflectance (R m(445-≧1185) as described) of 2.9% or less, preferably 2.6%, at an incident angle of 45° or less with respect to wavelengths in the range from 445 nm to at least 1185 nm or more of a predetermined maximum wavelength. The present invention relates to an optical article, preferably an ophthalmic lens.

[0014] Generally, the predetermined maximum wavelength is in the range of 1185 nm to 1200 nm and may correspond to, for example, 1185 nm or 1200 nm.

[0015] Accordingly, the optical article according to the present invention includes a highly efficient antireflection (AR) coating having very low reflection in both the visible region and the NIR region.

[0016] The present invention also provides an optical device which may be an augmented reality device, a virtual reality device, and an eye tracking device, including such an optical article and a light source emitting light in the deep red and near infrared regions.

[0017] To understand the description provided herein and its advantages in more detail, reference is now made to the following brief description in connection with the accompanying drawings and detailed description, where like reference numerals represent like parts.

Brief Description of the Drawings

[0018]

Figure 1

Figure 2a

Figure 2b

Mode for Carrying Out the Invention

[0019] In the following description, the drawings are not necessarily to scale, and certain features may be shown in generalized or schematic form for the sake of clarity and conciseness or for the purpose of providing information. In addition, the embodiments discussed in this specification are merely representative and do not limit the scope of the present invention.

[0020] 1. Definitions The terms "comprise" (and its grammatical variants such as "comprises" and "comprising"), "have" (and its grammatical variants such as "has" and "having"), "contain" (and its grammatical variants such as "contains" and "containing"), and "include" (and its grammatical variants such as "includes" and "including") are open-ended linking verbs. These are used to define the presence of the recited features, integers, steps, or components, or groups thereof, but do not preclude the presence or addition of one or more other features, integers, steps, or components, or groups thereof. As a result, a method or process that "comprises", "has", "contains", or "includes" one or more steps or elements has those one or more steps or elements, but is not limited to having only those one or more steps or elements.

[0021] Unless otherwise indicated, all numbers or expressions referring to amounts of ingredients, reaction conditions, etc. used in this specification are to be understood as being modified in all instances by the term "about".

[0022] Also, unless otherwise indicated, an indication of an interval of values "from X to Y" or "between X and Y" according to the present invention is meant to include the values of X and Y. In addition, unless otherwise indicated, for an interval of values, the expressions "lower than X" or "higher than Y" do not include the values of X or Y.

[0023] In this application, when an optical article includes one or more coatings on its surface, the expression "providing a layer or coating on the article" is intended to mean that the layer or coating is provided on the outer (exposed) surface of the outer coating of the article, i.e., the coating that is furthest from the substrate.

[0024] A coating that is said to be "on a substrate" or "provided above a substrate" is defined as (i) a coating disposed on the substrate, (ii) a coating that is not necessarily in contact with the substrate, i.e., one or more intermediate coatings may be disposed between the substrate and the coating, and (iii) a coating that does not necessarily completely cover the substrate.

[0025] In a preferred embodiment, the coating on the substrate or the coating provided above the substrate is in direct contact with this substrate.

[0026] When "layer 1 is under layer 2", it is intended to mean that layer 2 is further away from the substrate than layer 1.

[0027] According to the embodiments described below, the multilayer interference coating is preferably a multilayer antireflection coating. Therefore, in the following description, these two terms are similar.

[0028] The outermost layer of the multilayer antireflection coating means the layer of the antireflection (AR) coating that is farthest from the substrate.

[0029] The innermost layer of the multilayer antireflection coating means the layer of the antireflection coating that is closest to the substrate.

[0030] The inner layer of the multilayer antireflection coating means all layers of the antireflection coating except the outermost layer of the AR coating.

[0031] Also, unless otherwise specified, all thicknesses disclosed in this application relate to physical thickness.

[0032] The terms multilayer antireflection coating or AR coating, and AR laminate have the same meaning.

[0033] Unless otherwise specified, the refractive index referred to in this application is expressed at 25 °C at a wavelength of 550 nm.

[0034] The multilayer antireflection coating according to the present invention may be formed on at least one of the main surfaces of a bare substrate, i.e., a substrate that is not coated, or on at least one of the main surfaces of a substrate that has already been coated with one or more functional coatings such as a wear-resistant coating.

[0035] As used herein, the rear surface (or inner surface or concave surface or CC surface) of the substrate is intended to mean the surface that is closest to the wearer's eye when using the article. This is generally a concave surface. Conversely, the front surface (or convex surface or CX surface) of the substrate is the surface that is farthest from the wearer's eye when using the article. This is generally a convex surface.

[0036] Also, as used herein, a "transparent substrate" is understood to be transparent when the observation of an image through the substrate is perceived without a significant loss of contrast, i.e., when the formation of an image through the substrate is obtained without adversely affecting the quality of the image.

[0037] The term aesthetic appearance means that there are no or almost no aesthetic defects visually evaluated in terms of transmittance, preferably measured under an arc lamp.

[0038] The term "robustness" of an optical article such as an ophthalmic lens in the present invention is defined as the ability of the lens to resist changes despite the changes introduced by its manufacturing process. These changes depend, for example, on the type of substrate used, the settings of the manufacturing apparatus (temperature schedule, suitable time, electron gun settings, etc.) and / or its mode of use, and the replacement of the manufacturing apparatus with other apparatuses.

[0039] In fact, when manufacturing an anti-reflection coating on an industrial scale, generally, some thickness variations occur in each layer. These variations lead to different anti-reflection performances, especially differences in the perceived residual reflection color of the multi-layer anti-reflection coating. If the perceived residual reflection colors of the anti-reflection coatings of two lenses are different, these lenses will look different and cannot be associated as a pair.

[0040] According to the present invention, the "angle of incidence (symbol θ)" is an angle formed by a light ray incident on the surface of an ophthalmic lens and a perpendicular line to the surface at the incident point. The light ray is, for example, an illumination light source such as the standard light source D65 defined by the international colorimetric method CIE L*a*b* (1976). Generally, the angle of incidence varies from 0° (normal incidence) to 90° (glancing incidence). The normal range of the angle of incidence is from 0° to 75°.

[0041] The colorimetric properties (such as chroma C* and hue "h") of the optical article of the present invention in the international colorimetric system CIE L*a*b* (1976) are calculated at 380 to 780 nm considering the standard light source D65 and the observer (at an angle of 10°). The observer is the "standard observer" defined in the international colorimetric system CIE L*a*b*. In fact, in the CIE L*a*b* space, it is also possible to express not only the overall change in color but also in relation to one or more of the parameters L*, a*, and b*. Using this, new parameters can be defined and associated with the attributes of visual perception. The transparency related to lightness is directly represented by the value of L*. Chroma: C* = (a *2 + b 2 ) 1 / 2 defines the chroma. Hue angle: h = tg-1(b * / a * )(expressed in degrees) is related to the hue.

[0042] The average transmittance (abbreviated as Tm) is as defined in the ISO13666:1998 standard and is measured in accordance with the ISO8980-4 standard (generally at an incident angle of less than 17°, typically 15°), that is, this represents the average of the spectral transmittance (without weighting) across the entire optical spectrum from 400 nm to 700 nm.

[0043] By analogy, the average transmittance, also called the "luminance transmittance" of the system, is defined between 445 nm and 1185 nm and is abbreviated as "T m (445 - 1185)", which corresponds to the average of the spectral transmittance (without weighting) within the wavelength range of 445 nm to 1185 nm.

[0044] In this specification, unless otherwise specified, the transmittance / transmission is measured at the center of an optical article at an incident angle in the range of 0° to 15°, preferably at an incident angle of 0°, and with a thickness in the range of 0.7 to 2 mm, preferably in the range of 0.8 to 1.5 mm. In this specification, the transmitted light refers to the light that reaches the front main surface of the optical article and passes through the lens.

[0045] In this specification, R v The "apparent reflectance" denoted as such is as defined in the ISO 13666:1998 standard and is measured in accordance with ISO 89804, that is, this is the weighted average value of the spectral reflectance across the entire visible spectrum from 380 to 780 nm. R v Although it is usually measured at an incident angle of less than 17°, typically 15°, it can be evaluated for any incident angle.

[0046] In this application, R m(X-Y) The "average reflectance" denoted as such is as defined in the ISO 13666:1998 standard and is measured in accordance with the ISO 8980-4 standard, that is, this is the average value of the spectral reflectance (without weighting) across the electromagnetic spectrum between the wavelengths "X" and "Y" nm. According to the present invention, R m is measured for different incident angles.

[0047] For example, the characteristic average reflectance (R m(900-1000) as denoted) for wavelengths in the range of 900 nm to 1000 nm is defined by the following formula, assuming a measurement step of 1 nm. [Equation] Here, R(λ) represents the reflectance at wavelength λ.

[0048] R m(900-1000) can be measured at any incident angle θ based on R(λ) measured at the same incident angle.

[0049] Also, according to the present invention, the maximum reflectance (R max(400-1200) or R max(445-1185) as denoted) over the entire spectrum in the range of 400 nm to 1200 nm or 445 nm to 1185 nm corresponds to the maximum reflectance value (highest value) measured for the entire spectrum in the range of 400 nm to 1200 nm or 445 nm to 1185 nm, respectively.

[0050] 2. Optical article The optical article according to the present invention is a transparent optical article, preferably a lens or a lens blank, more preferably an ophthalmic lens or a lens blank. The optical article can be coated with the multilayer antireflection coating of the present invention on its convex main surface (front surface), concave main surface (back surface), or both surfaces.

[0051] A°) Substrate Generally speaking, the interference multilayer coating of the optical article according to the present invention may be an antireflection coating (hereinafter referred to as an AR coating), and can be deposited on any substrate, preferably an organic lens substrate, such as a thermoplastic or thermosetting plastic material.

[0052] The thermoplastic can be selected, for example, from polyamide; polyimide; polysulfone; polycarbonate and its copolymers; poly(ethylene terephthalate) and polymethyl methacrylate (PMMA).

[0053] The thermosetting material can be selected, for example, from cycloolefin copolymers such as ethylene / norbornene or ethylene / cyclopentadiene copolymers; homopolymers and copolymers of allyl carbonates of linear or branched aliphatic or aromatic polyols such as homopolymer of diethylene glycol bis(allyl carbonate) (CR 39 (registered trademark)); homopolymers and copolymers of (meth)acrylic acid and its esters derivable from bisphenol A; polymers and copolymers of thio(meth)acrylic acid and its esters, polymers and copolymers of allyl esters derivable from bisphenol A or phthalic acid and allyl aromatics such as styrene, polymers and copolymers of urethane and thiourethane, polymers and copolymers of epoxy, and polymers and copolymers of sulfide, disulfide, and episulfide, and combinations thereof.

[0054] In this specification, (co)polymer is intended to mean copolymer or polymer. As used herein, (meth)acrylate is intended to mean acrylate or methacrylate. As used herein, polycarbonate (PC) is intended to mean either homopolycarbonate or copolycarbonate and block copolycarbonate.

[0055] Homopolymer of diethylene glycol bis(allyl carbonate) (CR 39 (registered trademark)), allyl and (meth)acrylic copolymers having a refractive index of 1.54 to 1.58, polymers and copolymers of thiourethane, and polycarbonate are preferred. The substrate can be coated with one or more functional coatings before depositing the anti-reflection coating of the present invention. These functional coatings conventionally used in optics can be, but are not limited to, an impact-resistant primer layer, an abrasion-resistant coating and / or a scratch-resistant coating, a polarizing coating, a photochromic coating or a coloring coating. Hereinafter, the substrate means either a bare substrate or such a coated substrate.

[0056] Preferably, the substrate, and optionally the abrasion-resistant coating, and / or the scratch-resistant coating generally coated on the substrate have similar / close refractive indices to avoid fringes or aesthetic defects.

[0057] Before providing the anti-reflection coating, the surface of the substrate is usually subjected to a physical or chemical surface activation treatment to enhance the adhesion of the anti-reflection coating. Such a pretreatment is generally carried out under vacuum. This may be, for example, an impact by energy species and / or reactive species using an ion beam (“ion pre-cleaning” or “IPC”) or an electron beam, a corona discharge treatment, an ion stripping treatment, an ultraviolet treatment, or a plasma-mediated treatment under vacuum using normal oxygen or argon plasma. It may also be a treatment with an acid or a base and / or a solvent-based treatment (water, hydrogen peroxide, or any organic solvent).

[0058] B°) Multilayer anti-reflection coating Hereinafter, the multilayer anti-reflection coating of the present invention will be described.

[0059] As described above, the multilayer anti-reflection coating of the present invention is a broadband anti-reflection coating that is effective for high incident angles, particularly 45° or more, and for wavelengths in the range of 445 nm to 1185 nm, thus covering almost the visible region to the NIR region.

[0060] In fact, the multilayer antireflection coating has an average reflectance (R m(445-≧1185) as denoted) of 2.9% or less, preferably 2.8% or less, particularly preferably 2.7% or less, typically preferably 2.6% or less at an incident angle of 45° or less with respect to wavelengths from 445 nm to a predetermined maximum wavelength of 1185 nm or more.

[0061] Generally, the predetermined maximum wavelength is in the range of 1185 nm to 1200 nm and can correspond to, for example, 1185 nm or 1200 nm.

[0062] In particular, the average reflectance (R m(445-1185) as denoted) of wavelengths in the range of 445 nm to 1185 nm is 2.9% or less, preferably 2.8% or less, particularly preferably 2.7% or less, typically preferably 2.6% or less at an incident angle of 45° or less.

[0063] According to a feature of the present invention, the multilayer interference coating has an average reflectance R m(445-≧1185) of 7% or less, preferably 6.8% or less, particularly preferably 2.7% or less, typically preferably 2.6% or less at an incident angle of 60° or less.

[0064] According to another feature of the present invention, the multilayer interference coating has a maximum reflectance (R max(445-1185) as denoted) of 4.5% or less, preferably 3% or less, typically 2.55% or less at an incident angle of 0° over the entire spectrum in the range of 445 nm to 1185 nm.

[0065] As used herein, the interval of 4.5% or less includes (including the limit values) the following values and / or any interval included between these values. 4.4; 4.3; 4.2; 4.1; 4.0; 3.9; 3.8; 3.7; 3.6; 3.5; 3.4; 3.3; 3.2; 3.1; 3.0; 2.9; 2.8; 2.7; 2.6; 2.5; 2.49; 2.48; 2.47, etc.

[0066] Therefore, the applicant has surprisingly discovered that the multilayer antireflection coating according to the present invention enables obtaining a low reflectance in both the visible region and the near-infrared (445 - 1185 nm), regardless of the incident angle (0° - 60°). This surprising effect is shown in the following examples.

[0067] In addition, the multilayer antireflection coating according to the present invention also presents the advantage of having good robustness and aesthetic appearance regardless of the incident angle. As will be explained below, for low incident angles in the range of 0° - 30°, the chroma C* is 20 or less, and for higher incident angles (30° or more), the chroma C* is less than 10. Therefore, the multilayer antireflection coating of the present invention has good color achromaticity. In particular, the antireflection coating according to the present invention has a residual reflection color with less saturated color, thereby overcoming the change in the (observer-perceived) residual reflection color of the antireflection coating between two optical articles / lenses (including said antireflection coating) that may occur especially during the manufacturing process on an industrial scale.

[0068] In one embodiment, the multilayer antireflection coating according to the present invention does not absorb or absorbs very little in the visible region and the NIR region, which, in the context of the present application, means that its minimum transmittance (T min(445-1185) as denoted) at an incident angle of 0° is more than 92%, more preferably more than 95%, still more preferably more than 96%, most preferably more than 97%, especially more than 97.5%.

[0069] In particular, for incident angles in the range of 0° - 15°, the transmittance T m(445-1185) is preferably more than 98%, more preferably more than 98.6%.

[0070] In addition, for higher incident angles such as 60°, the transmittance T m(445-1185) is preferably more than 92.8%, more preferably more than 93%, especially more than 93.4%.

[0071] In particular, the multilayer antireflection coating according to the invention also has a very low reflectivity at 900 to 1000 nm (i.e., in the middle of the NIR region in the range of 780 to 1400 nm), and preferably has a very low reflectivity at 900 to 1200 nm for different angles of incidence as described below.

[0072] In fact, the multilayer interference coating has, in particular, for wavelengths in the range from 900 nm to 1000 nm (R m(900-1000) as denoted), preferably for wavelengths in the range from 900 nm to 1200 nm (R m(900-1200 ) as denoted), an average reflectivity of 1% or less at an angle of incidence of less than 35° or an angle of incidence of 30° or less.

[0073] As used herein, the interval of 1.0% or less includes (including the limit values) the following values and / or any interval included between these values. 0.99; 0.98; 0.97; 0.96; 0.95; 0.94; 0.93; 0.92; 0.91; 0.90; 0.89; 0.85; 0.80; 0.79; 0.78; 0.77; 0.76; 0.75; 0.74; 0.73; 0.72; 0.70 etc.

[0074] For higher angles of incidence, in particular in the range from 35° to 45° such as 45°, the multilayer interference coating preferably has an R m(900-1000) or R m(900-1200) of 4% or less, preferably 3% or less, typically 2.0% or less.

[0075] As used herein, the interval of 4.0% or less includes (including the limit values) the following values and / or any interval included between these values. 3.9; 3.8; 3.7; 3.6; 3.5; 3.4; 3.3; 3.2; 3.1; 3.0; 2.9; 2.8; 2.7; 2.6; 2.5; 2.49; 2.48; 2.47; 2.46; 2.45; 2.40; 2.38; 2.36; 2.34; 2.32; 2.3; 2.2; 2.1; 2.0; 1.9; 1.8; 1.7; 1.6; 1.5; 1.4; 1.3; 1.2; 1.1 etc.

[0076] In addition, for even higher angles of incidence of 60°, the multilayer interference coating preferably has an R that is 9% or less, preferably 7% or less, and typically 6% or less at an angle of incidence of 60°. m(900-1000) or R m(900-1200) has.

[0077] As used herein, an interval of 9% or less includes (including the limit values) the following values and / or any interval included between these values: 9; 8.9; 8.7; 8.6; 8.5; 8.4; 8.3; 8.2; 8.1; 8.0; 7.9; 7.8; 7.6; 7.5; 7.4; 7.3; 7.2; 7.1; 7.0; 6.9; 6.8; 6.7; 6.6; 6.5; 6.4; 6.3; 6.2; 6.1; 6.0; 5.9; 5.8; 5.7; 5.6; 5.5; 5.4, etc.

[0078] The multilayer interference coating is also generally characterized by a ratio R of 1.1 or less, preferably 1.0 or less, and typically 0.9 or less for high angles of incidence in the range of 0° to 60°, particularly in the range of 45° to 60°. m(900-1000) / R m(445-1185) where R m(900-1000) is as defined above, and R m(445-1185) corresponds to the average reflectance for wavelengths in the range of 445 nm to 1185 nm.

[0079] In addition, the multilayer interference coating is also generally characterized by a ratio R of 1.1 or less, preferably 1.0 or less, and typically 0.9 or less for high angles of incidence in the range of 0° to 60°, particularly in the range of 45° to 60°. m(900-1200) / R m(445-1185) where R m(900-1200) is as defined above, and R m(445-1185) corresponds to the average reflectance for wavelengths in the range of 445 nm to 1185 nm.

[0080] Furthermore, the multilayer antireflection coating according to the present invention also has a very low reflectance in the visible region, particularly for wavelengths in the range of 400 to 700 nm, and this is the same for different angles of incidence as will be explained below.

[0081] In fact, the multilayer interference coating preferably has an average reflectance (R m(400-700) , as denoted) of 3.0% or less, preferably 2.5% or less, typically 2.3% or less, at an incident angle of 45° or less with respect to wavelengths in the range of 400 nm to 700 nm.

[0082] As used herein, an interval of 4.0% or less includes (including the limit values) the following values and / or any interval included between these values. 3.0; 2.9; 2.8; 2.7; 2.6; 2.5; 2.49; 2.48; 2.47; 2.46; 2.45; 2.40; 2.38; 2.36; 2.34; 2.32; 2.3; 2.2; 2.1; 2.0; 1.9; 1.8; 1.7; 1.6; 1.5; 1.4; 1.3; 1.2; 1.1 and the like.

[0083] Furthermore, as described above, the multilayer interference coating of the present invention has a smoothly perceptible residual color change depending on the incident angle θ.

[0084] In fact, according to the features of the present invention, the multilayer interference coating preferably has a chroma C* of the reflected light (measured according to the international color system CIE L*a*b* using the standard light source D65) of 20 or less at an incident angle of less than 30° (such as in the range of 0° to 15°). For the same incident angle, the chroma C* is generally 8 or more, particularly 9 or more.

[0085] In parallel, for an incident angle of less than 30°, particularly in the range of 0° to 15°, the change in the hue "h" (for example, the hue value at 0° and the hue value at 15°), named as Δh (0°-15°) , is very short. In fact, Δh (0°-15°) is generally 10 or less, preferably 9 or less, typically 5 or less.

[0086] The multilayer interference coating also preferably has a chroma C* of the reflected light that is 10 or less, preferably 6.8 or less, typically 6 or less, for an incident angle of 30° or more, preferably for an incident angle in the range of 45° to 65°. For the same incident angle, the chroma C* is generally 0.5 or more, particularly 1 or more.

[0087] For such incident angles, the hue changes slightly between different incident angles of 30°, 45°, and 60°. However, because the chroma C* is very low, these hue changes do not appear to the observer.

[0088] Therefore, as shown in the following examples, the hue h of the antireflection coating is substantially constant (the change in hue "Δh" is very low) for incident angles that vary in the range of 0° to 15°, i.e., typically 280° to 320°. In fact, the residual reflected color perceived when the incident angle changes between 0° and 15° is "the same" for an observer with normal vision, and this is the case even if the chroma varies in the range of 8 to 20. When the hue of the antireflection coating begins to change for incident angles of 30° or more (such as 30°, 45°, 60°, etc.), since the chroma C* is very low (10 or less), i.e., the perceived residual reflected color is very faint, the observer cannot perceive or can hardly notice the residual reflected color. Therefore, the residual reflected color of the antireflection coating of the lens according to the present invention is uniform regardless of the incident angle. Therefore, it has good aesthetic performance (smooth color change according to the incident angle).

[0089] Therefore, the antireflection coating according to the present invention has a residual reflected color with little saturated color so as to overcome the change in the (perceived by the observer) residual reflected color of the antireflection coating between two lenses (including the antireflection coating) that can occur particularly during the manufacturing process on an industrial scale.

[0090] Without being bound by any theory, the presence of at least two local maxima or peaks in the visible region of 380 to 780 nm of the AR coating of the present invention (i.e., the two maximum wavelengths of lenses 1 to 4 according to the present invention, and the three maximum wavelengths of lens 5 according to the present invention, as shown in FIGS. 2a and 2b) enables better color expansion and / or balance characteristics, and since this is possible even at very low incident angles, it is considered possible to obtain better color achromaticity. It is considered that the two or three local maxima can complement each other to provide a reflection with less saturated color. For example, in Comparative Example 1 (when the incident angle is 0°), the chroma C* is 25, whereas in Example 1 according to the present invention, it is a value close to 18. Since this is close to half of the chroma C* of Comparative Example 1, the color of the AR coating according to the present invention is much less visible and has no presence. Also, the two local maxima slightly affect the image carried to the wearer's eyes, and it is considered easier to compensate for the color distortion effect using this double level.

[0091] Here, different structures of the multilayer antireflection coating of the present invention will be described.

[0092] As described above, the multilayer antireflection coating of the present invention includes a laminate of at least two layers made of dielectric materials having a high refractive index (HI) and a low refractive index (LI).

[0093] Preferably, the antireflection coating includes at least two layers having a low refractive index (LI), more preferably at least three layers, and at least two layers having a high refractive index layer (HI), more preferably at least three layers. Since the total number of layers of the antireflection coating is 4 or more and generally 14 or less, here it is a simple laminate.

[0094] According to the features of the present invention, the total number of layers of the antireflection coating is 4 or more, more preferably 6 or more, typically 7 or more, particularly 8 or more, and can be 10 or more.

[0095] According to another feature of the present invention, the total number of layers in the antireflection coating is 14 or less, more preferably 12 or less, and even more preferably 10 or less.

[0096] As used herein, the layers of the antireflection coating are defined as having a thickness of 1 nm or more. Therefore, a layer with a thickness of less than 1 nm is not considered when counting the number of layers in the antireflection coating. Sub-layers as described below are also not considered when counting the number of layers of the antireflection coating.

[0097] According to one embodiment of the present invention, the HI layer and the LI layer do not necessarily alternate with each other in the laminate, but may alternate. Two (or more) HI layers may be deposited on top of each other, and two (or more) LI layers may be deposited on top of each other.

[0098] Generally, the HI layer and the LI layer alternate with each other in the laminate of the AR coating according to the present invention.

[0099] Advantageously, the multilayer interference coating alternately includes HI layers and LI layers and has a number of layers of 4 or more, preferably 6 or more.

[0100] Preferably, the total thickness of the antireflection coating is 650 nm or less, more preferably 600 nm or less, and even more preferably 560 nm or less. The total thickness of the reflective coating is generally more than 300 nm, preferably 320 nm or more. Typically, the physical thickness of the antireflection coating is 320 to 560 nm.

[0101] As used herein, the interval of 650 nm or less includes the following values and / or any interval included between these values (including the limit values). 650; 600; 550; 540; 530; 520; 510; 500; 490; 480; 470; 480; 470; 460; 450; 440; 430; 420; 410; 400; 390; 380; 370; 360; 350; 340; 330; 320; 310; 300, etc.

[0102] Unless otherwise specified, all thicknesses disclosed in this application relate to physical thickness.

[0103] According to the features of the present invention, the multilayer interference (AR) coating includes at least the following "general structure" in the direction moving towards the substrate (from air to the substrate). - L1: One LI layer having a physical thickness of 95 nm to 130 nm, preferably 100 nm to 120 nm; - L2: One HI layer having a physical thickness of 30 nm to 60 nm, preferably 40 nm to 50 nm; - L3: One LI layer having a physical thickness of 5 nm to 25 nm, preferably 8 nm to 20 nm; - L4: One HI layer having a physical thickness of 80 nm to 130 nm, preferably 90 nm to 125 nm; - L5: One LI layer having a physical thickness of 5 nm to 40 nm, preferably 8 nm to 35 nm; - L6: One HI layer having a physical thickness of 15 nm to 50 nm, preferably 20 nm to 40 nm.

[0104] In particular, according to the first embodiment, the multilayer interference (AR) coating includes at least the following in the direction moving towards the substrate (from air to the substrate). - L1: One LI layer having a physical thickness of 100 nm to 125 nm, preferably 115 nm to 120 nm; - L2: One HI layer having a physical thickness of 40 nm to 55 nm, preferably 35 nm to 50 nm; - L3: One LI layer having a physical thickness of 8 nm to 25 nm, preferably 10 nm to 20 nm; - L4: One HI layer having a physical thickness of 85 nm to 120 nm, preferably 90 nm to 110 nm; - L5: One LI layer having a physical thickness of 5 nm to 30 nm, preferably 8 nm to 25 nm; - L6: One HI layer having a physical thickness of 20 nm to 45 nm, preferably 25 nm to 40 nm.

[0105] According to the general and first embodiments, the multilayer antireflection (AR) coating may also include the following additional layers in the direction moving towards the substrate (from air to the substrate). - L7: One LI layer having a physical thickness of 15 nm to 55 nm, preferably 20 nm to 50 nm; - Optional L8: One HI layer having a physical thickness of 3 nm to 35 nm, preferably 5 nm to 30 nm; - Optional L9: One LI layer having a physical thickness of 8 nm to 50 nm, preferably 10 nm to 45 nm; - Optional L10: One HI layer having a physical thickness of 1 nm to 10 nm, preferably 1 nm to 5 nm.

[0106] According to a specific embodiment, the multilayer antireflection (AR) coating may also include the following additional layers with respect to the above general structure, particularly between the L6 HI layer and the substrate, in the direction moving towards the substrate (from air to the substrate). - L7: One LI layer having a physical thickness of 15 nm to 50 nm, preferably 20 nm to 50 nm, more preferably 40 nm to 50 nm; - L8: One HI layer having a physical thickness of 5 nm to 30 nm, preferably 10 nm to 30 nm, more preferably 10 nm to 20 nm; - L9: One LI layer having a physical thickness of 10 nm to 50 nm, preferably 30 nm to 50 nm, more preferably 40 to 50 nm; - L10: One HI layer having a physical thickness of 1 nm to 10 nm, preferably 1 nm to 5 nm.

[0107] According to the second embodiment, the multilayer interference coating of the present invention may include a thick LI layer disposed closest to the substrate. In particular, this layer is an additional LI layer with respect to the general structure described above and corresponds to L7'. Thus, the multilayer interference coating may include one additional LI layer disposed closest to the substrate and having a physical thickness in the range of 180 nm or more, preferably 200 nm to 250 nm.

[0108] The applicant has discovered that this thick LI layer L7' not only functions as an optical layer but also enables it to function as a layer that significantly improves the scratch resistance of the AR coating. In addition, this second embodiment has a very low reflectance in both the visible region and the NIR region (see lens 5 according to the present invention in the following examples).

[0109] In particular, according to this second embodiment, the multilayer interference (AR) coating may include at least the following in the direction of moving towards the substrate (from air to the substrate). - L1: One LI layer having a physical thickness of 95 nm to 130 nm, preferably 100 nm to 120 nm, typically 110 - 115 nm; - L2: One HI layer having a physical thickness of 30 nm to 60 nm, preferably 40 nm to 50 nm, typically 40 - 45 nm; - L3: One LI layer having a physical thickness of 5 nm to 25 nm, preferably 8 nm to 20 nm, typically 8 - 15 nm; - L4: One HI layer having a physical thickness of 80 nm to 130 nm, preferably 90 nm to 125 nm, typically 105 - 120 nm; - L5: One LI layer having a physical thickness of 5 nm to 40 nm, preferably 8 nm to 35 nm, typically 28 - 35 nm; - L6: One HI layer having a physical thickness of 15 nm to 50 nm, preferably 20 nm to 40 nm, typically 20 - 30 nm; - L7': One thick LI layer having a physical thickness of 180 nm to 250 nm, preferably 200 nm to 220 nm.

[0110] According to another feature of the present invention, the AR coating may include an antistatic layer (also referred to as a conductive layer) as described below. Generally, this antistatic layer is disposed under, preferably immediately under, i.e., under L1, the "L1 outer layer" in the direction of moving away from the substrate.

[0111] According to the present invention, the HI layer is a conventional high refractive index layer well-known in the art. This typically includes, but is not limited to, one or more metal oxides such as zirconia (ZrO2), alumina (Al2O3), tantalum pentoxide (Ta2O5), praseodymium oxide (Pr2O3), praseodymium titanate (PrTiO3), lanthanum oxide (La2O3), yttrium oxide (Y2O3), niobium pentoxide (Nb2O5), titanium dioxide (TiO2), and mixtures thereof. Preferred materials include zirconia (ZrO2) and tantalum pentoxide (Ta2O5). According to a feature of the present invention, the HI layer is zirconia (ZrO2) (refractive index 1.997). Optionally, the HI layer may further include silica or other materials having a low refractive index, provided that the refractive index is 1.55 or more, preferably 1.6 or more, as indicated above.

[0112] The LI layer is also well-known and may include, but is not limited to, MgF2, SiO2, a mixture of silica and alumina, particularly silica doped with alumina (alumina contributes to an increase in the heat resistance of the antireflection coating), or mixtures thereof. The LI layer is a layer preferably containing at least 80% by weight, more preferably at least 90% by weight, of silica based on the total weight of the layer, and more preferably consists of a silica layer (SiO2) (refractive index 1.473). Optionally, the LI layer may further include a material having a high refractive index or a very high refractive index, provided that the refractive index of the resulting layer is less than 1.55.

[0113] When a LI layer containing a mixture of SiO2 and Al2O3 is used, it preferably contains 1 to 10 wt%, more preferably 1 to 8 wt%, still more preferably 1 to 5 wt% of Al2O3 based on the total weight of SiO2 + Al2O3 in such a layer.

[0114] For example, SiO2 doped with up to 4 wt% of Al2O3, or SiO2 doped with 8% of Al2O3 can be used. Commercially available SiO2 / Al2O3 mixtures such as LIMA® (refractive index n = 1.48 - 1.50 at 550 nm) sold by Umicore Materials AG or L5® (refractive index n = 1.48 at 500 nm) sold by Merck KGaA can be used.

[0115] As described above, the ophthalmic lens of the present invention can be antistatic, i.e., prevent the retention and / or generation of substantial electrostatic charges, by incorporating at least one conductive layer into the laminate present on the surface of the article.

[0116] The ability of the glass to remove the electrostatic charge obtained after generating an electrostatic charge (such as the charge applied by corona) by rubbing with a piece of cloth or using any other means can be quantified by measuring the time required for the charge to dissipate. Thus, the antistatic glass has a discharge time of about several hundred milliseconds, preferably 500 ms or less, while for the electrostatic glass this is about several tens of seconds. In the present application, the discharge time is measured according to the method disclosed in French Patent No. 2943798.

[0117] As used herein, the "conductive layer" or "antistatic layer" is intended to mean a layer that, by being present on the surface of a non-conductive substrate (i.e., a substrate with a discharge time of more than 500 ms), enables the discharge time after applying an electrostatic charge to its surface to be 500 ms or less.

[0118] The conductive layer can be arranged at various positions within the laminate, usually within the antireflection coating or in contact with the antireflection coating, provided that its antireflection properties are not affected. This is preferably arranged between two layers of the antireflection coating and / or preferably adjacent to the high refractive index layer of such an antireflection coating. Preferably, the conductive layer is arranged directly below the low refractive index layer of the antireflection coating, and most preferably, it is arranged directly below the silica-based outer layer of the antireflection coating, which is the second last layer of the antireflection coating: for example, the "LI outer layer".

[0119] The conductive layer needs to be thin enough so as not to change the transparency of the antireflection coating. The conductive layer is preferably made of a highly conductive and transparent material, usually a metal oxide which may optionally be doped. In this case, its thickness preferably varies in the range of 1 to 15 nm, more preferably 1 to 10 nm. Preferably, the conductive layer contains a metal oxide which may optionally be doped, selected from indium, tin, zinc oxide, and mixtures thereof. Tin-indium oxide (In2O3:Sn, indium oxide doped with tin), zinc oxide doped with aluminum (ZnO:Al), indium oxide (In2O3), and tin oxide (SnO2) are preferred. In the most preferred embodiment, the conductive and optically transparent layer is a tin-indium oxide layer, referred to as an ITO layer or a tin oxide layer.

[0120] Normally, the conductive layer contributes to obtaining antireflection properties within the laminate, although in a limited form due to its thin thickness, and represents the high refractive index layer in the antireflection coating. This is the case for a layer made of a highly conductive and transparent material such as an ITO layer.

[0121] The antireflection coating does not include a layer based on indium oxide with a thickness of 20 nm or more, preferably more than 15 nm. When a plurality of indium oxide-based layers are present in the antireflection coating, their total thickness is preferably less than 20 nm, more preferably less than 15 nm. As used herein, an indium oxide-based layer is intended to mean a layer containing at least 50% by weight of indium oxide based on the total weight of the layer.

[0122] According to a preferred embodiment, the antireflection coating does not include a layer containing indium oxide, tin oxide, or zinc oxide with a thickness of 20 nm or more, preferably more than 15 nm. When a plurality of layers containing indium oxide, tin oxide, or zinc oxide are present in the antireflection coating, their total thickness is preferably less than 20 nm, more preferably less than 15 nm.

[0123] C°) Sub-layer In one embodiment of the present invention, the antireflection coating can be deposited on a sub-layer. It should be noted that such a sub-layer does not belong to the antireflection coating.

[0124] As used herein, a sub-layer or an adhesion layer is intended to mean a relatively thick coating used to improve mechanical properties such as the abrasion resistance and / or scratch resistance of the coating and / or to enhance adhesion to the substrate or the underlying coating.

[0125] Due to its relatively large thickness, especially when it has a refractive index close to that of the underlying substrate (usually a coating with abrasion resistance and scratch resistance or a bare substrate), the sub-layer usually does not participate in antireflection optical activity.

[0126] The sub-layer is sufficient to promote the abrasion resistance of the antireflection coating, but preferably light absorption (this depends on the nature of the sub-layer and the relative transmittance τ vIt is necessary to have a thickness such that (it will significantly reduce), but does not occur. The thickness is usually less than 300 nm, more preferably less than 200 nm, usually more than 90 nm, more preferably more than 100 nm.

[0127] The sub-layer preferably includes a SiO2-based layer, which preferably contains at least 80% by weight of silica, more preferably at least 90% by weight of silica, based on the total weight of the layer, and more preferably consists of a silica layer. The thickness of such a silica-based layer is usually less than 300 nm, more preferably less than 200 nm, usually more than 90 nm, more preferably more than 100 nm.

[0128] In another embodiment, this SiO2-based layer is a silica layer doped with an amount of alumina as defined above in this specification, and preferably consists of a silica layer doped with alumina.

[0129] In a specific embodiment, the sub-layer consists of a SiO2 layer.

[0130] Preferably, a single-layer type of sub-layer will be used. However, the sub-layer may be of a multi-layer type, especially when the sub-layer and the underlying substrate have substantially different refractive indices. This applies especially when the underlying substrate has a high refractive index, i.e., a refractive index of 1.55 or more, preferably 1.57 or more.

[0131] In this case, the sub-layer is inserted between a layer with a thickness of 90 - 300 nm called the main layer and such a layer with a thickness of 90 - 300 nm, which is generally a silica-based layer and is optionally coated on the substrate. It may include preferably up to 3 layers, more preferably up to 2 additional layers. These additional layers are preferably thin layers, and their function is, if necessary, to limit the reflection at the coating interface of the sub-layer / underlying layer or the sub-layer / substrate interface.

[0132] The multilayer sublayer preferably includes, in addition to the main layer, a layer having a high refractive index and a thickness of 80 nm or less, more preferably 50 nm or less, and most preferably 30 nm or less. Such a layer with a high refractive index is in direct contact, if necessary, with a high refractive index substrate or an underlying high refractive index coating. Of course, this embodiment can be used even when the substrate (or the underlying coating) has a refractive index of less than 1.55.

[0133] As an alternative, the sublayer includes, in addition to the main layer and the aforementioned layer with a high refractive index, a layer made of a SiO2-based (i.e., preferably containing at least 80 wt% silica) material having a refractive index of 1.55 or less, preferably 1.52 or less, more preferably 1.50 or less, and a thickness of 80 nm or less, more preferably 50 nm or less, even more preferably 30 nm or less, on which the layer with a high refractive index is deposited. Typically, in this example, the sublayer is composed of a 25 nm thick SiO2 layer, a 10 nm thick ZrO2 or Ta2O5 layer, and then the main layer of the sublayer, deposited in this order, on an optionally coated substrate.

[0134] According to one embodiment, the anti-reflection coating is not deposited on the sublayer as described above. For example, in the case of the second embodiment of the AR coating according to the present invention, the optical article generally does not include a sublayer.

[0135] D°) Process The various layers of the anti-reflection coating and the optional sublayer are preferably deposited by chemical vapor deposition under vacuum according to any of the following methods: i) vapor deposition, which may optionally be assisted by an ion beam; ii) ion beam sputtering; iii) cathode sputtering; iv) plasma-assisted chemical vapor deposition. These various methods are described in the references "Thin Film Processes" and "Thin Film Processes II", edited by Vossen & Kern, Academic Press, 1978 and 1991, respectively. The particularly recommended method is vapor deposition under vacuum.

[0136] Preferably, the deposition of each layer of the antireflection coating and of the optional sub-layers is carried out by evaporation under vacuum.

[0137] E°) Other functional layers Generally, the front major face and / or the rear major face of the substrate on which the antireflection coating is provided is coated with an impact-resistant primer layer, an abrasion- and / or scratch-resistant coating, or an impact-resistant primer layer coated with an abrasion- and / or scratch-resistant coating.

[0138] The antireflection coating according to the invention is preferably provided on top of an abrasion- and / or scratch-resistant coating.

[0139] The abrasion- and / or scratch-resistant coating may be any layer conventionally used as an abrasion- and / or scratch-resistant coating in the field of ophthalmic lenses.

[0140] The abrasion- and / or scratch-resistant coating is preferably a hard coating based on poly(meth)acrylate or silane and generally contains one or more inorganic fillers intended to increase the hardness and / or the refractive index of the coating after curing.

[0141] The abrasion- and / or scratch-resistant hard coating is preferably prepared from a composition containing at least one alkoxysilane and / or its hydrolysis product obtained by hydrolysis using, for example, a hydrochloric acid solution and an optional condensation and / or curing catalyst.

[0142] Suitable coatings recommended for the purposes of the present invention include coatings based on epoxy silane hydrolysis products such as those described in French Patent No. 2702486 (European Patent No. 0614957), US Patent No. 4211823, and US Patent No. 5015523.

[0143] The abrasion-resistant and / or scratch-resistant coating composition may be deposited on the main surface of the substrate by dip coating or spin coating. This is then cured by a suitable method (preferably using heat or ultraviolet light).

[0144] The thickness of the abrasion-resistant and / or scratch-resistant coating varies, usually being 2 to 10 μm, preferably 3 to 5 μm.

[0145] Before providing the abrasion-resistant coating and / or scratch-resistant coating, a primer coating can also be applied on the substrate to improve the impact resistance and / or adhesiveness of subsequent layers in the final product. This coating may be any impact-resistant primer layer conventionally used in articles of transparent polymer-based materials such as ophthalmic lenses.

[0146] Preferred primer compositions are polyurethane-based compositions and latex-based compositions, and in particular, a polyurethane-type latex which may optionally contain polyester units.

[0147] Such a primer composition can be deposited on the surface of the article by dip coating or spin coating, and then dried at a temperature of at least 70 °C and at most 100 °C, preferably about 90 °C, for a time in the range of 2 minutes to 2 hours, usually about 15 minutes, to form a primer layer having a thickness of 0.2 to 2.5 μm, preferably 0.5 to 1.5 μm after curing.

[0148] The ophthalmic lens according to the present invention may also include a coating formed on the antireflection coating and capable of changing its surface properties such as a hydrophobic and / or oleophobic coating (antifouling top coat). These coatings are preferably deposited on the outer layer of the antireflection coating. In principle, their thickness is 10 nm or less, preferably in the range of 1 to 10 nm, more preferably 1 to 5 nm.

[0149] Instead of a hydrophobic coating, a hydrophilic coating that imparts anti-fogging properties, or an anti-fogging precursor coating that imparts anti-fogging properties when used in combination with a surfactant, may be used. Examples of such anti-fogging precursor coatings are described in WO 2011 / 080472 pamphlet.

[0150] Typically, the ophthalmic lens according to the present invention comprises a substrate whose back surface is sequentially coated with an impact-resistant primer layer, an abrasion-resistant and scratch-resistant layer, an anti-ultraviolet and anti-reflection coating, and a hydrophobic and / or oleophobic coating, or a hydrophilic coating that imparts anti-fogging properties, or an anti-fogging precursor coating.

[0151] On the front surface of the substrate of the ophthalmic lens, an impact-resistant primer layer, an abrasion-resistant layer, and / or a scratch-resistant layer, the anti-reflection coating according to the present invention, and a hydrophobic coating and / or an oleophobic coating may be sequentially coated.

[0152] The optical article according to the present invention is preferably an ophthalmic lens such as an eyeglass lens, or a blank for an eyeglass lens. The lens may be a polarizing lens, a photochromic lens, or a solar lens, and may or may not be colored, and may or may not be corrected.

[0153] Therefore, the present invention provides an anti-reflection coating having an improved concept, including a relatively thin laminate made of a plurality of layers, the thickness and material of which are selected to obtain a good compromise between satisfactory anti-reflection performance and very low reflection simultaneously in the NIR region and the visible region, and having robustness characteristics and a good aesthetic appearance.

[0154] 3. Optical Device The present invention also relates to an optical device described below.

[0155] In particular, the optical device comprises a light source emitting at least in the deep red and near-infrared regions, and an optical article as defined above. Generally, the optical article is an ophthalmic lens and includes all the characteristics described above for the optical article according to the invention, either in combination or not. Generally, this optical article is or is incorporated into an eye-tracking device, an augmented reality device, or a virtual reality device.

[0156] For example, the optical device may correspond to that described in the pamphlet of International Patent Application No. PCT / EP2019 / 074697.

[0157] In particular, the optical device according to the invention may comprise an ophthalmic lens (as described above) and a light source emitting in the deep red and near-infrared regions, i.e., at wavelengths in the range of 700 nm to 2500 nm.

[0158] The light source may be, for example, a light-emitting diode (LED).

[0159] In order to detect the light emitted from the light source, it is possible to use, without a deep red and NIR filter, a video camera of the CCD (charge-coupled device) type or CMOS (complementary metal-oxide semiconductor) type sensitive to NIR wavelengths. As a variant, instead of a camera, an array of single deep red and NIR sensors, a PSD (position-sensitive detector) sensor or other suitable sensors can be used.

[0160] For example, FIG. 1 shows a non-limiting example of a configuration in an augmented reality device or a virtual reality device including the optical device according to the invention.

[0161] The optical device includes an ophthalmic lens 10 disposed between the user's eye 14 on the one hand and an optical element 12 on the other hand. The optical element 12 can be, for example, a waveguide having coupling means for coupling light and output coupling means for output-coupling light towards the user's eye 14, so that the user can perceive a virtual image.

[0162] The horizontal arrow 11 passing through the optical element 12 and through the ophthalmic lens 10 represents light coming from the environment.

[0163] The deep red and NIR eye trackers are also included in the augmented reality device or virtual reality device. The deep red and NIR eye trackers include a deep red and NIR camera 16 and at least one deep red and NIR light source 18, and the light source 18 is included in the optical device according to the present invention.

[0164] In the embodiment shown in FIG. 1, the light source 18 is disposed between the optical element 12 and the ophthalmic lens 10, while the camera 16 is disposed in front of the optical element 12.

[0165] As a variant, the camera 16 and the light source 18 may be disposed in front of the optical element 12.

[0166] As another variant, the optical element 12 can be used both for providing a virtual image and for providing light illumination. Then, the light reflected by the eye 14 can return to the optical element 12 and be redirected to the deep red and NIR light sensors.

[0167] The ophthalmic lens 10 can provide an optical function to the user. It can be, for example, a corrective lens for treating myopia, hyperopia, astigmatism and / or presbyopia, i.e., a spherical, cylindrical and / or additional type of refractive power lens for a user with refractive anomalies. Since the lens 10 can have a certain refractive power, it can provide the same refractive power as provided by a single focus lens or can be a progressive lens with variable refractive power.

[0168] Also, it includes the above-described AR coating having a very low reflectivity in both the visible region and the NIR region on its rear principal surface and / or its front principal surface.

[0169] Therefore, the antireflection coating is designed to reduce the reflectance in the deep red and NIR regions, so that the camera 16 receives little light coming from the reflection on the lens 10 regardless of the incident angle (0° to 60°).

[0170] The following examples are more detailed but illustrate the invention in a non-limiting manner.

Example

[0171] 4. Example A°) General procedure The optical article used in the example had a diameter of 65 m, a refractive index of 1.60 (MITSUI's MR-8 (registered trademark) lens), a refractive power of -2.00 diopters, and a center thickness of 1.2 mm, and included a lens substrate coated on its front surface with a 3-μm-thick hard coat (Erys Misrill 1.6 hard coat) having a refractive index of 1.59.

[0172] The layer of the antireflection coating was deposited on the front surface of the tested lens without heating the substrate by evaporation under vacuum (evaporation source: electron gun).

[0173] The evaporation frame was a Leybold 1104 device equipped with an electron gun (ESV14 (8 kV)) for evaporating oxides and an ion gun (Commonwealth Mark II) for the preliminary step of preparing the surface of the substrate using argon ions (IPC).

[0174] The thickness of the layer was controlled by a crystal oscillator microbalance. The spectral measurement was performed with a Perkin-Elmer Lambda 850 variable-incidence spectrophotometer equipped with a URA accessory (Universal Reflectance Accessory).

[0175] B°) Test procedure The manufacturing method of the optical article / lens of the present invention includes the steps of introducing a substrate coated with an abrasion-resistant and scratch-resistant coating into a vacuum deposition chamber, pumping until a high vacuum is obtained, activating the front surface of the substrate using an argon ion beam (anode current: 1 A, anode voltage: 100 V, neutralization current: 130 mA), turning off the ion irradiation, and forming various layers of an anti-reflection coating by continuous evaporation on the back surface, and finally ventilating.

[0176] For comparison, two comparative examples, namely Comparative Example 1 (Nikon's product Seecoat) and Comparative Example 2 (pamphlet of International Patent Application No. PCT / EP2019 / 074697), were reproduced. Comparative Example 1 includes a sublayer made of SiO2 coated on a misril hard coat 1.6 and a layer of ITO (tin-doped indium oxide) consisting of 90% indium oxide.

[0177] C°) Results Hereinafter, the structural characteristics and optical performance of the ophthalmic lenses 1 to 5 obtained in Examples 1 to 5 according to the present invention and the comparative lenses 1 and 2 obtained in Comparative Examples 1 and 2 (prior art) will be described in detail.

[0178] The reflectance graphs of these lenses 1 to 5 and Comparative Examples 1 and 2 at 307 to 1175 nm are shown in FIGS. 2a and 2b with an incident angle of 0°.

[0179] The optical values are those of the front surface. The rates Tm, Rm, and Rmax of the reflected light are described for incident angles of 0°, 15°, 30°, 45°, 60°, a standard light source D65, and a standard observer (angle 10°).

[0180] Structure The test lenses 1 to 5 according to the present invention and the comparative lenses 1 and 2 have the following structure (unit nm - physical thickness) in the direction of moving from the air toward the substrates L1 to L10 ("Mat" means material).

[0181] [Table 1]

[0182]

Table 2

[0183] From this Table 2, it can be observed that the lenses 1 to 5 according to the present invention have very good antireflection characteristics in both the visible region and the NIR region regardless of the incident angle (0° to 60°) with respect to the lenses according to the prior art.

[0184] Actually, the maximum reflectance at an incident angle of 0° is very low for wavelengths in the range of 445 to 1185 nm, and is in the range of 1.82 (lens 5) to 2.50 (lens 2), but the maximum reflectance is 8.84% with respect to Comparative lens 1 and 5.02% with respect to Comparative lens 2.

[0185] In addition, the average reflectance Rm for different incident angles of 0°, 15°, 30°, 45° and 60° for wavelengths in the range of 445 to 1185 nm is very low compared to the average reflectances of Comparative lenses 1 and 2.

[0186]

Table 3

[0187] As shown in Table 3 above, the minimum transmittance Tmin at an incident angle of 0° for wavelengths in the range of 445 to 1185 nm is higher for the lenses 1 to 5 of the present invention than for Comparative lenses 1 and 2. In addition, the same is true especially for the average transmittance at an incident angle of 60°.

[0188]

Table 4

[0189] Table 4 above shows that for wavelengths of 900 to 1200 nm, the average reflectance Rm for different incident angles of 0°, 15°, 30°, 45°, and 60° is lower for Lenses 1 to 5 of the present invention than for Comparative Examples 1 and 2.

[0190]

Table 5

[0191]

Table 6

[0192] It can be observed that the AR coatings of Lenses 1 to 5 according to the present invention enable a substantially constant hue to be obtained for incident angles varying in the range of 0° to 15°. In fact, Δh (change in hue) is very low and ranges from 4 (Lens 5) to 9 (Lens 4). In parallel, the chroma C* is lower than 20. Therefore, the residual reflected color perceived when the incident angle changes from 0 to 15° is "the same" for an observer with normal vision, and this is the same even if the chroma is in the range of 8 to 20.

[0193] Also, for incident angles of 30° or more (such as 30°, 45°, and 60°), it can be observed that the chroma C* of the AR coatings of Lenses 1 to 5 is very low (10 or less). Therefore, the perceived residual reflected color is very faint, and as a result, even if the hue changes, the residual reflected color is not perceivable or hardly noticeable to the observer.

[0194] Therefore, Lenses 1 to 5 have good aesthetic performance (smooth color change according to the incident angle), especially when compared with Comparative Lens 1 (the residual reflected color is more saturated in color, i.e., the chroma is 25 and remains high even when the hue changes).

[0195]

Table 7

[0196] Lenses 1 to 5 have very low Rv values in the visible region and can be observed regardless of the incident angle, especially when compared with Comparative Example 1. The present disclosure includes the following aspects of the invention: <Aspect 1> A transparent substrate having a front main surface and a rear main surface, wherein at least one of the main surfaces is coated with a multilayer interference coating including a laminate of at least one high refractive index layer (HI) having a refractive index of 1.55 or more and at least one low refractive index layer (LI) having a refractive index of less than 1.55. In an optical article including the transparent substrate, the multilayer interference coating has an average reflectance (R m(445-≧1185) as denoted) of 2.9% or less at an incident angle of 45° or less with respect to wavelengths in the range from 445 nm to a predetermined maximum wavelength of 1185 nm or more. <Aspect 2> The optical article according to Aspect 1, wherein the multilayer interference coating has an average reflectance R m(445-≧1185) of 7% or less, preferably 6.8% or less, at an incident angle of 60° or less. <Aspect 3> The optical article according to Aspect 1 or 2, wherein the multilayer interference coating has a maximum reflectance (R max(445-1185) as denoted) of 4.5% or less, preferably 3% or less, typically 2.55% or less, at an incident angle of 0° over the entire spectrum in the range of 445 nm to 1185 nm. <Aspect 4> The optical article according to any one of Aspects 1 to 3, wherein the multilayer interference coating has an average reflectance (R m(900-1000) as denoted) of 1% or less at an incident angle of less than 35°, preferably at an incident angle of 30°, with respect to wavelengths in the range of 900 nm to 1000 nm. <Aspect 5> The optical article according to any one of Aspects 1 to 4, wherein the multilayer interference coating has an average reflectance of 4% or less, preferably 3% or less, typically 2.0% or less, at an incident angle in the range of 35° to 45° with respect to wavelengths in the range of 900 nm to 1000 nm denoted by R m(900-1000) or with respect to wavelengths in the range of 900 nm to 1200 nm denoted by R m(900-1200) . <Aspect 6> The optical article according to any one of Aspects 1 to 5, wherein the multilayer interference coating has an average reflectance of 9% or less, preferably 7% or less, typically 6.0% or less, at an incident angle of 60° with respect to wavelengths in the range of 900 nm to 1000 nm denoted by R m(900-1000) or with respect to wavelengths in the range of 900 nm to 1200 nm denoted by R m(900-1200) . <Aspect 7> The multilayer interference coating has a ratio: R at an incident angle in the range of 0° to 60°, preferably in the range of 45° to 60° m(900-1000) / R m(445-1185) R is 1.1 or less, preferably 1.0 or less, typically 0.9 or less. m(900-1000) The average reflectance for wavelengths in the range of 900 nm to 1000 nm, denoted as R, and m(445-1185) The optical article according to any one of Aspects 1 to 6, having an average reflectance for wavelengths in the range of 445 nm to 1185 nm, denoted as R. <Aspect 8> The optical article according to any one of Aspects 1 to 7, wherein the multilayer interference coating has a chroma C* of reflected light that is 20 or less at an incident angle of less than 30° according to the international color system CIE L*a*b* using the standard light source D65. <Aspect 9> The optical article according to any one of Aspects 1 to 8, wherein the multilayer interference coating has a chroma C* of reflected light that is 10 or less at an incident angle of 30° or more, preferably in the range of 45° to 65°, according to the international color system CIE L*a*b* using the standard light source D65. <Aspect 10> The optical article according to any one of Aspects 1 to 9, wherein the multilayer interference coating alternately includes HI layers and LI layers and has 4 or more, preferably 6 or more, layers. <Aspect 11> In the direction of movement toward the substrate, the multilayer interference coating has at least - One LI layer having a physical thickness of 95 nm to 130 nm, preferably 100 nm to 120 nm; - One HI layer having a physical thickness of 30 nm to 60 nm, preferably 40 nm to 50 nm; - One LI layer having a physical thickness of 5 nm to 25 nm, preferably 8 nm to 20 nm; - One HI layer having a physical thickness of 80 nm to 130 nm, preferably 90 nm to 125 nm; - One LI layer having a physical thickness of 5 nm to 40 nm, preferably 8 nm to 35 nm; - One HI layer having a physical thickness of 15 nm to 50 nm, preferably 20 nm to 40 nm The optical article according to any one of Aspects 1 to 10, including. <Aspect 12> The optical article according to Aspect 11, wherein the multilayer interference coating includes one additional LI layer that is disposed closest to the substrate and has a physical thickness in the range of 180 nm or more, preferably 200 to 250 nm. <Aspect 13> Between the HI layer having a physical thickness of 15 nm to 50 nm, preferably 20 nm to 40 nm, and the substrate, in the direction of movement toward the substrate, - One LI layer having a physical thickness of 15 nm to 50 nm, preferably 20 nm to 50 nm, more preferably 40 nm to 50 nm; - One HI layer having a physical thickness of 5 nm to 30 nm, preferably 10 nm to 30 nm, more preferably 10 nm to 20 nm; - One LI layer having a physical thickness of 10 nm to 50 nm, preferably 30 nm to 50 nm, more preferably 40 to 50 nm; - One HI layer having a physical thickness of 1 nm to 10 nm, preferably 1 nm to 5 nm The optical article according to aspect 11, comprising an additional layer consisting of. <Aspect 14> - The at least one HI layer contains one or more metal oxides selected from zirconia (ZrO 2 ), titanium dioxide (TiO 2 ), alumina (Al 2 O 3 ), tantalum pentoxide (Ta 2 O 5 ), neodymium oxide (Nd 2 O 5 ), praseodymium oxide (Pr 2 O 3 ), praseodymium titanate (PrTiO 3 ), lanthanum oxide (La 2 O 3 ), niobium oxide (Nb 2 O 5 ), yttrium oxide (Y 2 O 3 ), preferably zirconia, and - The LI layer contains silica (SiO 2 ), The optical article according to any one of aspects 1 to 13. <Aspect 15> An optical device comprising a light source that emits light in the deep red and near-infrared regions, comprising the optical article according to the preceding aspects 1 to 13, and being an augmented reality device, a virtual reality device, or an eye-tracking device.

Claims

1. A transparent substrate having a front major surface and a rear major surface, wherein at least one of the major surfaces is coated with a multilayer interference coating including a laminate of at least one high refractive index layer (HI) having a refractive index of 1.55 or more and at least one low refractive index layer (LI) having a refractive index of less than 1.55, in an optical article including the transparent substrate, the multilayer interference coating having an average reflectance (denoted as Rm(445 - 1185)) for wavelengths in the range from 445 nm to a predetermined maximum wavelength equal to 1185 nm or an average reflectance (denoted as Rm(445 - 1200)) for wavelengths in the range from 445 nm to a predetermined maximum wavelength equal to 1200 nm, which is 2.9% or less at an incident angle of 45°, characterized in that, the multilayer interference coating, in the direction of movement towards the transparent substrate, at least, - L1: one LI layer having a physical thickness of 95 nm to 130 nm; - L2: one HI layer having a physical thickness of 30 nm to 60 nm; - L3: one LI layer having a physical thickness of 5 nm to 25 nm; - L4: one HI layer having a physical thickness of 80 nm to 130 nm; - L5: one LI layer having a physical thickness of 5 nm to 40 nm; - L6: one HI layer having a physical thickness of 15 nm to 50 nm is included, L1 is the outermost layer, and different layers of the multilayer interference coating are in direct contact with each other, Optical article.

2. The optical article according to claim 1, wherein the multilayer interference coating has an average reflectance Rm(445 - 1185) or an average reflectance Rm(445 - 1200) that is 7% or less at an incident angle of 60°.

3. The optical article according to claim 2, wherein the multilayer interference coating has an average reflectance Rm(445 - 1185) or an average reflectance Rm(445 - 1200) that is 6.8% or less at an incident angle of 60°.

4. The maximum reflectance (R ｍａｘ（４４５－１１８５） ｍａｘ（４４５－１１８５） as described) of the multilayer interference coating is 4.5% or less at an incident angle of 0° over the entire spectrum in the range of 445 nm to 1185 nm, and the optical article according to any one of claims 1 to 3.

5. The optical article according to claim 4, wherein the multilayer interference coating has a maximum reflectance (R ｍａｘ（４４５－１１８５） as described) that is 3% or less at an incident angle of 0°.

6. The average reflectance (R ｍ（９００－１０００） as described) of the multilayer interference coating is 1% or less at an incident angle of less than 35° with respect to wavelengths in the range of 900 nm to 1000 nm. The optical article according to any one of claims 1 to 5.

7. The multilayer interference coating has an R ｍ（９００－１０００） for wavelengths in the range of 900 nm to 1000 nm described as, or an R ｍ（９００－１２００） for wavelengths in the range of 900 nm to 1200 nm described as, and has an average reflectance of 4% or less at an incident angle in the range of 35° to 45°. The optical article according to any one of claims 1 to 6.

8. The R of the multilayer interference coating is 3% or less at an incident angle in the range of 35° to 45° ｍ（９００－１０００） The optical article according to claim 7, having this

9. The multilayer interference coating has an R ｍ（９００－１０００） with respect to wavelengths in the range of 900 nm to 1000 nm described as, or R ｍ（９００－１２００） with respect to wavelengths in the range of 900 nm to 1200 nm described as, and has an average reflectance of 9% or less at an incident angle of 60°. The optical article according to any one of claims 1 to 8.

10. wherein the multilayer interference coating has a ratio: R ｍ（９００－１０００） / R ｍ（４４５－１１８５） of 1.1 or less at an incident angle in the range of 0° to 60°, the average reflectance for wavelengths in the range of 900 nm to 1000 nm, denoted as R ｍ（９００－１０００） and the average reflectance for wavelengths in the range of 445 nm to 1185 nm, denoted as R ｍ（４４５－１１８５） The optical article according to any one of claims 1 to 9, having

11. The optical article according to any one of claims 1 to 10, wherein the multilayer interference coating has a chroma C* of reflected light that is 20 or less at an incident angle of less than 30° according to the international color system CIE L*a*b* using the standard light source D65.

12. The optical article according to claim 11, wherein the multilayer interference coating has a chroma C* of reflected light that is 10 or less at an incident angle of 30° or more according to the international color system CIE L*a*b* using the standard light source D65.

13. The optical article according to any one of claims 1 to 12, wherein the multilayer interference coating includes one additional LI layer called L7', the additional LI layer L7' is disposed closest to the transparent substrate, and has a physical thickness in the range of 180 nm or more.

14. Between the HI layer having a physical thickness of 15 nm to 50 nm and the transparent substrate, in the direction of moving toward the transparent substrate, the multilayer interference coating - L7: One LI layer having a physical thickness of 15 nm to 55 nm; The optical article according to any one of claims 1 to 12, including an additional layer consisting of

15. Between the HI layer having a physical thickness of 15 nm to 50 nm and the transparent substrate, in the direction of moving toward the transparent substrate, the multilayer interference coating - L7: One LI layer having a physical thickness of 15 nm to 55 nm; - L8: One HI layer having a physical thickness of 3 nm to 35 nm The optical article according to any one of claims 1 to 12, including an additional layer consisting of

16. Between the HI layer having a physical thickness of 15 nm to 50 nm and the transparent substrate, in the direction of moving toward the transparent substrate, the multilayer interference coating - L7: One LI layer having a physical thickness of 15 nm to 55 nm; - L8: One HI layer having a physical thickness of 3 nm to 35 nm; - L9: One LI layer having a physical thickness of 8 nm to 50 nm The optical article according to any one of claims 1 to 12, including an additional layer consisting of

17. Between the HI layer having a physical thickness of 15 nm to 50 nm and the transparent substrate, in the direction of moving toward the transparent substrate, the multilayer interference coating - L7: One LI layer having a physical thickness of 15 nm to 55 nm; - L8: One HI layer having a physical thickness of 3 nm to 35 nm; - L9: One LI layer having a physical thickness of 8 nm to 50 nm; - L10: One HI layer having a physical thickness of 1 nm to 10 nm The optical article according to any one of claims 1 to 12, including an additional layer consisting of

18. An optical device comprising a light source that emits light in the deep red and near-infrared regions, comprising the optical article according to the preceding claims 1 to 17, and being an augmented reality device, a virtual reality device, or an eye-tracking device.

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