Lens

Abstract

The present disclosure relates to a lens comprising: a lens portion; a multilayer anti-reflection (AR) coating including one or both of a low refractive index layer and a high refractive index layer, and disposed on one surface of the lens portion; and a waterproof layer including a waterproof agent and disposed on one surface of the multilayer AR coating layer. One or both of the low refractive index layer and the high refractive index layer are formed of a nitride-based material having a band gap greater than 3.1 eV.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority from Korean Patent Application No. 10-2023-0084294 filed on June 29, 2023, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety for all purposes by reference. Technical Field

[0003] The following description refers to lenses. Background Art

[0004] Technologies related to automotive electrical components, such as advanced driver assistance systems (ADAS), autonomous driving, etc., as well as electronic camera modules and optical sensors are constantly evolving.

[0005] In particular, the market for camera modules using lenses is growing rapidly. Cameras used in vehicles have also been adopted in various locations such as front / rear / side.

[0006] However, for cameras used in vehicles, since the cameras are exposed to the outside most of the time, defects such as foreign matter adsorption, lens surface contamination and scratches may often occur due to the external environment, which may affect the performance of the camera module.

[0007] The outermost lens in the lens for electronic components may realize anti-reflection characteristics in a multi-layer stacked structure, and the materials generally used may include oxide-based materials such as TiO 2 、SiO 2 wait.

[0008] The above information is presented as background information only to assist in understanding the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above may be applicable as prior art with respect to the present disclosure. Summary of the invention

[0009] This Summary is provided to introduce a selection of concepts in a simplified form that are further described in the Detailed Description below. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

[0010] In one general aspect, a lens includes: a lens portion; a multilayer anti-reflection (AR) coating including one or both of a low refractive index layer and a high refractive index layer and disposed on one surface of the lens portion; and a water-repellent layer including a water-repellent and disposed on one surface of the multilayer AR coating. One or both of the low refractive index layer and the high refractive index layer are formed of a nitride-based material having a band gap greater than 3.1 eV.

[0011] The low refractive index layer may include SiO 2 The first layer is formed, and the high refractive index layer includes TiO 2 The second layer is formed.

[0012] The low refractive index layer may include a fourth layer formed of a nitride-based material, and the high refractive index layer may include a third layer formed of a nitride-based material.

[0013] The fourth layer may be formed of TiN, and the third layer may be formed of Si 3 N 4 Or AlN is formed.

[0014] The thickness of the fourth layer may be 50 nm or less.

[0015] The low refractive index layer may include SiO 2 The first layer is formed of a nitride-based material and the fourth layer is formed of a nitride-based material, and the high refractive index layer may include a TiO 2 A second layer is formed and a third layer is formed of a nitride-based material.

[0016] In the multi-layer AR coating, the first layer and the second layer may be alternately stacked, and the uppermost portion of the multi-layer AR coating may be the third layer or the fourth layer.

[0017] The low refractive index layer may include SiO 2 The formed first layer, and the high refractive index layer may include a third layer formed of a nitride-based material.

[0018] On the uppermost first layer of the multi-layer AR coating, one or both of a third layer and a fourth layer may be further disposed as one or more layers, the fourth layer being a low refractive index layer formed of a nitride-based material.

[0019] The low refractive index layer may include a fourth layer formed of a nitride-based material, and the high refractive index layer may include a fourth layer formed of a TiO 2 The second layer is formed.

[0020] On the uppermost second layer of the multi-layer AR coating, one or both of a fourth layer and a third layer may be further disposed as one or more layers, the third layer being a high refractive index layer formed of a nitride-based material.

[0021] In the multi-layer AR coating, the first layer and the second layer may be alternately stacked, and a third layer having a high refractive index or a fourth layer having a low refractive index formed of a nitride-based material may be disposed in a middle portion thereof.

[0022] The third layer or the fourth layer may be formed thicker than the first layer and the second layer.

[0023] One or both of the third layer and the fourth layer may also be disposed at the uppermost end of the multi-layer AR coating as one or more layers.

[0024] The lens may also include a functional coating including a UV improving additive and disposed between the multi-layer AR coating and the water-resistant layer.

[0025] Other features and aspects will be apparent from the following detailed description, drawings, and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a perspective view schematically illustrating a lens according to an exemplary embodiment of the present disclosure.

[0027] Figure 2 As a conventional example, SiO 2 and TiO 2 A cross-sectional view of an AR coating formed corresponding to Figure 1 Section 'A' in Fig.

[0028] Figures 3 to 23 are cross-sectional views illustrating various exemplary embodiments of the AR coating of the present disclosure.

[0029] Fig.24 is a graph showing the Mohs (Mohs) hardness of each material.

[0030] Figure 25 to Figure 28 is a conceptual diagram and table showing the band gaps of materials suitable for optical AR coatings.

[0031] Fig.29 is a graph showing the band gap of each material.

[0032] Fig.30 is a graph showing the transmittance of each material.

[0033] Fig.31 is a graph showing the measurement results of the nanoindenter for each material.

[0034] Fig.32 and Fig.33 is a conceptual diagram showing a single-layer structure with discrete refractive indices.

[0035] Fig.34 is a conceptual diagram showing a discrete refractive index multilayer structure.

[0036] Fig.35 is an exploded view schematically showing a structure of a digital camera according to an exemplary embodiment.

[0037] Throughout the drawings and detailed description, unless otherwise described, the same reference numerals refer to the same elements. For clarity, illustration, and convenience, the drawings may not be drawn to scale, and the relative sizes, proportions, and descriptions of the elements in the drawings may be exaggerated. DETAILED DESCRIPTION

[0038] Hereinafter, although examples of the present disclosure will be described in detail with reference to the accompanying drawings, it should be noted that the examples are not limited thereto.

[0039] The following specific embodiments are provided to help the reader gain a comprehensive understanding of the methods, devices, and / or systems described herein. However, various changes, modifications, and equivalents of the methods, devices, and / or systems described herein will be apparent after understanding the present disclosure. For example, the order of operations described herein is merely an example and is not limited to the order set forth herein, but may be changed as will be apparent after understanding the present disclosure, except for operations that must occur in a certain order. In addition, descriptions of features known in the art may be omitted for clarity and brevity.

[0040] The features described herein may be implemented in different forms and are not to be construed as being limited to the examples described herein. Rather, the examples described herein are provided only to illustrate some of the many possible ways to implement the methods, devices, and / or systems described herein that will be apparent after understanding the present disclosure.

[0041] Throughout the specification, when an element (such as a layer, a region, or a substrate) is described as being “on”, “connected to”, or “coupled to” another element, it may be directly “on”, directly “connected to”, or directly “coupled to” the other element, or one or more other elements may be present between them. Conversely, when an element is described as being “directly” “on”, “directly connected to”, or “directly coupled to” another element, there are no other elements present between them.

[0042] As used herein, the term "and / or" includes any one of the associated listed items and any combination of any two or more of the associated listed items; similarly, "at least one of..." includes any one of the associated listed items and any combination of any two or more of the associated listed items.

[0043] Although terms such as "first", "second", and "third" may be used herein to describe various members, components, regions, layers, or portions, these members, components, regions, layers, or portions are not limited by these terms. Instead, these terms are only used to distinguish one member, component, region, layer, or portion from another member, component, region, layer, or portion. Therefore, the first member, first component, first region, first layer, or first portion mentioned in the examples described herein may also be referred to as the second member, second component, second region, second layer, or second portion without departing from the teachings of the examples.

[0044] For ease of description, spatially relative terms such as "above", "upper", "below", and "lower" may be used herein to describe the relationship of one element to another element as shown in the drawings. In addition to the orientation depicted in the drawings, such spatially relative terms are intended to also include different orientations of the device in use or operation. For example, if the device in the drawings is turned over, an element described as being "above" or "upper" relative to another element will then be "below" or "lower" relative to the other element. Therefore, the term "above" includes both the orientation of the above and below, depending on the spatial orientation of the device. The device may also be oriented in other ways (e.g., rotated 90 degrees or in other orientations), and the spatially relative terms used herein will be interpreted accordingly.

[0045] The terms used herein are only used to describe various examples and are not used to limit the present disclosure. The words "a", "an" and "the" are intended to include plural forms as well, unless the context clearly indicates otherwise. The terms "include", "comprises" and "have" specify the presence of stated features, quantities, operations, components, elements and / or combinations thereof, but do not exclude the presence or addition of one or more other features, quantities, operations, components, elements and / or combinations thereof.

[0046] Due to manufacturing techniques and / or tolerances, the shapes shown in the drawings may vary. Therefore, the examples described herein are not limited to the specific shapes shown in the drawings but include shape variations that occur during manufacturing.

[0047] Herein, it is noted that the use of the term “may” with respect to an example, such as with respect to what an example may include or implement, means that there is at least one example that includes or implements this feature, and all examples are not limited thereto.

[0048] As will be apparent after understanding the present disclosure, the features of the examples described herein may be combined in various ways. In addition, although the examples described herein have multiple configurations, other configurations are also possible, as will be apparent after understanding the present disclosure.

[0049] In the lens structure including a water-repellent layer of the present disclosure, at least one layer of anti-reflective (AR) coating can be formed of a nitride-based material, or the entire AR coating can be formed of a nitride-based material, wherein the material is selected to have a band gap characteristic exceeding 3.1 eV, thereby improving the hardness of the lens.

[0050] Figure 1 is a perspective view schematically illustrating a lens according to an exemplary embodiment of the present disclosure.

[0051] Reference Figure 1 , the lens 101 according to an embodiment of the present disclosure includes a lens portion 110 , an anti-reflection (AR) coating 210 , and a waterproof layer 120 .

[0052] Regarding the lens part 110 , there is no particular limitation on its shape or type, and may be implemented in the form of a lens that can be used in an optical device such as a camera module.

[0053] Therefore, the shape of the lens portion 110 may be formed to have a shape similar to Figure 1 The shapes shown in the figure are different shapes.

[0054] The lens portion 110 may be formed of glass. However, the lens portion 110 may be formed of another material, such as a plastic resin including a resin component.

[0055] For example, the plastic resin may include at least one of polycarbonate and polyolefin.

[0056] Here, the polyolefin may include at least one of a cycloolefin polymer and a cycloolefin copolymer.

[0057] The AR coating 210 may be used to reduce the reflectivity of the surface of the lens 101 , thereby reducing or preventing flare phenomena.

[0058] When the AR coating is formed by a single layer, Fig.32 Under the same conditions as (1) in formula 1, n can be optimized 2 Here, n 2 is AR coating, and n 3 It is the substrate.

[0059] Formula 1:

[0060]

[0061]

[0062] If n 1 is air and has a refractive index of 1, and n 3 With a refractive index of 1.5, then n 2The ideal refractive index can be minimized if it reaches 1.225.

[0063] However, none of the existing materials have a refractive index value of about 1.2, and the lowest known materials have a refractive index of around 1.3.

[0064] In addition, when the application wavelength to be used is added to (2) in equation 1, n can be calculated. 2 The layer thickness t.

[0065] Usually, based on 550nm (visible light range), n 2 The ideal thickness of the layer is about 112 nm.

[0066] In addition, Fig.33 In the case of a substrate or layer having a different refractive index, reflection occurs at the interface due to the change in discrete refractive index values.

[0067] In order to improve it, usually apply Fig.34 The AR coating with a multi-layer stack structure having a Bragg reflector structure is shown in FIG.

[0068] The multilayer AR coating has a structure in which a low refractive index layer and a high refractive index layer are repeatedly stacked.

[0069] However, when the AR coating is composed of SiO 2 Layer and TiO 2 When the layers are composed, the minimum reflectivity is about 0.5%, and when applying to the cover glass under the recent display of a mobile phone or applying an additional optical layer, the reflectivity needs to be a lower value.

[0070] With this in mind, in order to achieve ultra-low reflection, the refractive index should not change discretely. Fig.34 As shown in , it is advantageous to have a structure in which the refractive index n gradually changes from air to the substrate.

[0071] This structure can be viewed as a structure which clearly reduces the number of reflections at the interface because there is no interface where the refractive index changes rapidly, but the structure is difficult to realize in an actual system.

[0072] Therefore, considering all these points, the outermost lens among lenses for electronic components should eventually achieve anti-reflection in a multi-layer stacked structure.

[0073] Reference Figure 2The AR coating 200 (hereinafter, an intermediate layer is indicated in parallel with the AR coating) of the conventional lens 100 includes a multilayer structure in which a first layer 201 and a second layer 202 having different refractive indices are alternately stacked at least once. Here, reference numeral 110 is a lens portion, and reference numeral 120 is a waterproof layer.

[0074] In this case, the first layer 201 is made of SiO 2 The second layer 202 is formed as a low refractive index layer and is made of TiO 2 Formed as a high refractive index layer.

[0075] However, when the AR coating 200 is composed of the first layer 201 and the second layer 202, such as TiO 2 and SiO 2 The oxide-based material has weak hardness, which may easily cause scratches on the surface of the lens 100 due to the external environment.

[0076] Such scratches may cause video errors during autonomous driving, etc., which may lead to vehicle accidents.

[0077] In an exemplary embodiment of the present disclosure, in order to improve hardness, the AR coating is configured by replacing part or all of the first layer with the fourth layer (low refractive index layer) or replacing part or all of the second layer with the third layer (high refractive index layer).

[0078] In addition, the AR coating may be formed by replacing part or all of the first layer with the fourth layer (low refractive index layer) and part or all of the second layer with the third layer (high refractive index layer).

[0079] In this case, the criterion for distinguishing between materials having a high refractive index and a low refractive index is a refractive index of 1.5.

[0080] The material having a low refractive index is a material having a refractive index of less than 1.5, and the material having a high refractive index is a material having a refractive index of 1.5 or more.

[0081] Reference Figure 3 , the AR coating 210 of the lens 101 includes a first layer 201 and a second layer 202 alternately stacked from the lower end, and a third layer 203 (high refractive index layer) provided on the first layer 201 (low refractive index layer) at the uppermost end thereof.

[0082] The AR coating 210 may be formed by coating one surface of the lens portion 110 in an electron beam process using an electron beam evaporator apparatus having a thermal device.

[0083] In addition, refer to Figure 4In another example, the AR coating 211 of the lens 102 includes a first layer 201 and a second layer 202 alternately stacked from the lower end, and a fourth layer 204 (low refractive index layer) disposed on the second layer 202 (high refractive index layer) at its uppermost end.

[0084] Reference Fig.24 , in order to increase the hardness of the AR coating, nitride-based materials or carbide-based materials may be selected instead of oxide-based materials.

[0085] However, carbide-based materials may require high temperature deposition when depositing thin films or using primarily CVD methods. Therefore, high vacuum deposition equipment may be required, increasing deposition costs.

[0086] In order for carbide-based materials to be used for AR coatings, the bandgap properties of the material play a decisive role.

[0087] Figure 25 to Figure 28 is a conceptual diagram and table showing the band gaps of materials suitable for optical AR coatings.

[0088] Reference Figure 25 to Figure 28 , when the band gap Eg of a material is smaller than the photon energy which depends on the wavelength, the incident photon may not be transmitted through the layer and may be absorbed.

[0089] Additionally, reflection may occur when the band gap of the material has a low band gap that is very close to the conduction band and the valence band.

[0090] The nitride-based material used in the third layer 203 and the fourth layer 204 has a property of having a band gap exceeding 3.1 eV among all nitride-based materials.

[0091] Furthermore, among nitride-based materials having higher hardness than oxide-based materials, materials having a band gap greater than 3.1 eV are selected as shown in Table 1 below.

[0092] Table 1:

[0093]

[0094] In this case, the nitride-based material can be TiN, BN, Si 3 N 4 and at least one of AlN.

[0095] Fig.29 is a graph showing the band gap of each material. Fig.29 It shows that TiO 2 、SiO 2 and the bandgap of the selected nitride material.

[0096] refer to Fig.29, in nitride-based materials, can replace SiO 2 The material used as the low-refractive-index material is TiN, which has a refractive index of about 1.38.

[0097] In addition, the remaining Si 3 N 4 , BN and AlN can be classified as being able to replace TiO 2 High refractive index material.

[0098] Fig.31 is a graph showing the measurement result of the nano indenter of each material, which is obtained by measuring the hardness of a thin film of each material by depositing the thin film with a thickness of 200 nm using the nano indenter.

[0099] As a result of the measurement, in addition to BN, Si 3 N 4 , TiN and AlN all show higher hardness than oxide materials.

[0100] In the case of BN, after deposition, BN reacts with moisture and oxygen in the air to form B 2 O 3 (OH) hydroxide, which reduces adhesion to the glass over time and also gives lower hardness values ​​when the corresponding samples are measured with a nanoindenter.

[0101] Therefore, BN is considered unsuitable for AR coating due to these material properties.

[0102] Therefore, in the AR coating in the exemplary embodiment of the present disclosure, the fourth layer 204 may be formed of TiN, and the third layer 203 may be formed of Si. 3 N 4 Or AlN is formed.

[0103] Fig.30 is a graph showing the transmittance of each material.

[0104] To check the transmittance, SiO 2 、TiO 2 、Si 3 N 4 , TiN, BN and AlN materials are deposited to a thickness of 50nm. In this case, the substrate used is glass with a thickness of about 650μm.

[0105] Reference Fig.30 , as a result of measuring the transmittance of each deposited sample, most materials represented a transmittance of 70% or more (@550nm), but TiN represented a transmittance of about 35%.

[0106] Therefore, to optically use TiN, the layer thickness may be 50 nm or less to reduce the loss of transmittance.

[0107] The thickness can be measured using both non-destructive testing and destructive testing.

[0108] Non-destructive testing includes methods using ellipsometers, reflectometers, and atomic force microscopy.

[0109] As an example of destructive testing, after processing a cross section on the AR coating with a focused ion beam (FIB), a transmission electron microscope (TEM) analysis can be performed, and the composition can also be analyzed by EDS analysis. In addition, analysis can be performed using FT-IR, XPS, etc.

[0110] The cross-section of the AR coating may include a central portion of the lens portion 110 , ie, the thickest region of the lens portion 110 .

[0111] Furthermore, the thickness of the AR coating may be defined as a distance measured in a direction perpendicular to the surface thereof, and may be determined as a value obtained by averaging values ​​measured in a plurality of regions spaced apart from each other at equal intervals.

[0112] The waterproof layer 120 is disposed on one surface of the AR coating 210 .

[0113] In addition, in order to prevent the surface of the lens part 110 from being oxidized and to provide a self-cleaning effect to obtain a clear image, the waterproof layer 120 is used, and the waterproof layer 120 includes a waterproof agent.

[0114] In this case, as the water repellent, perfluoropolyether (PFPE) including a fluorine polymer, polytetrafluoroethylene (PTFE), fluorinated ethylene propylene (FEP), perfluoroalkyl vinyl ether copolymer (PFA), polyvinyl fluoride (PVF), or the like can be used.

[0115] The waterproof layer 120 may be formed by coating a waterproof agent on one surface of the AR coating 210 using an electron beam or thermal deposition process.

[0116] Meanwhile, if necessary, a functional coating (not shown) may also be disposed between the AR coating 210 and the waterproof layer 120 .

[0117] Functional coatings are intended to prevent UV reliability degradation and may include UV improving additives to achieve this purpose.

[0118] Examples of UV improving additives may include UV absorbers, antioxidants, and hindered amine light stabilizers.

[0119] The antioxidant may be preferably a phenol type or a phosphoric acid type, and a single type or a mixture of two or more types selected from the following substances may be used: tetramethylene (3,5-di-tert-butyl-4-hydroxycinnamate) methane, octadecyl 3,5-di-tert-butyl-4-hydroxyhydrocinnamate, ethylenebis (oxyethylene) bis-3-tert-butyl-4-hydroxy-5-methylhydrocinnamate, N-octadecyl-3-(3',5'-di-tert-butyl-4'-hydroxyphenyl) propionate, triethylene glycol bis [3-(3-tert-butyl-4-hydroxy-5-methylphenyl) propionate], 3,9-bis-[1,1-dimethyl-1-2-(3-tert-butyl-4-hydroxy-5-methylphenyl) propionylethyl]-2,4,8- 10-Tetraoxaasparto[5,5]undecane, 2,2-thiodiethylenebis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, tetrakis[methylene-3(3',5'-di-tert-butyl-4'-hydroxyphenyl)propionate]methane, phenylpropionic acid and 3,5-bis-(1,1-dimethyl-ethyl)-4-hydroxy-C7-C9 branched alkyl esters, and a single type or a mixture of two or more types selected from the following substances can be used: tetramethylene (3,5-di-tert-butyl)-4-hydroxycinnamic acid methane, 3,5-di-tert-butyl-4-hydroxyhydrocinnamic acid octadecyl ester, phenylpropionic acid and 3,5-bis-(1,1-dimethyl-ethyl)-4-hydroxy-C7-C9 branched alkyl esters.

[0120] The hindered amine light stabilizer may include one or more types selected from the following substances: N-(4-alkoxycarbonylphenyl)-N'-alkyl-N'-phenylformamide, hydroxyphenylbenzotriazole, bis-(1,2,2,6,6-pentamethyl-4-piperidinyl) cetyl ester and bis-(1-octyl-2,2,6,6-tetramethyl-4-piperidinyl) cetyl ester, and may include a single type or two or more types selected from the following substances: N-(4-methoxycarbonylphenyl)-N'-alkyl-N'-phenylformamide, N-(4-ethoxycarbonylphenyl)-N'-methyl-N'-phenylformamidine and N-(4-ethoxycarbonylphenyl)-N'-ethyl-N'-phenylformamidine.

[0121] The functional coating may be formed by coating one surface of the AR coating 210 with a UV improving additive through a thermal process or an electron beam process.

[0122] Additionally, the UV improving additive may include inorganic particles. In an example, the UV absorber may include inorganic particles.

[0123] In addition, the UV absorber may use a single type or a mixture of two or more types selected from the group consisting of 2-(3-tert-butyl-2-hydroxy-5-methoxyphenyl)-2H-benzotriazole-5-carboxylic acid methyl ester, 2-(2-hydroxy-5-methoxy-3-tert-octylphenyl)-2H-benzotriazole-5-carboxylic acid methyl ester, 2-(3-tert-butyl-2-hydroxy-5-methoxyphenyl)-2H-benzotriazole-5-carboxylic acid octyl ester, 2-(3-tert-butyl-2-hydroxy-5-methoxyphenyl)-2H-benzotriazole-5-carboxylic acid 2-ethylhexyl ester, 2-(3-tert-butyl-2-hydroxy-5-methoxyphenyl)-2H-benzotriazole-5-carboxylic acid 2-ethylhexyl ester, 2-(3-tert-butyl-2-hydroxy-5-octyloxyphenyl)-2H-benzotriazole-5-carboxylic acid methyl ester, 2-[3-tert-butyl-2-hydroxy-5-(2-methacryloyloxyethoxy)phenyl]-2H-benzotriazole-5-carboxylic acid methyl ester, 2-(3-tert-butyl-2-hydroxy-5-methoxyphenyl)-2H-benzotriazole-5-carboxylic acid phenyl ester, 2-methacryloyloxyethyl 2-(2-hydroxy-5-methoxyphenyl)-2H-benzotriazole-5-carboxylate, 2-acryloyloxyethyl 2-(3-tert-butyl-2-hydroxy-5-methoxyphenyl)-2H-benzotriazole-5-carboxylate, 2-methacryloyloxyethyl 2-(3-tert-butyl-2-hydroxy-5-methoxyphenyl)2H-benzotriazole-5-carboxylate.

[0124] In the case of forming the UV absorber using only an organic material, the chemical structure of the organic material may be deformed due to the photon energy of the UV light, and thus, there is a possibility that discoloration and deformation of the UV absorber may occur.

[0125] When inorganic particles are used as the UV absorber, such discoloration and deformation due to UV light can be minimized, so the reliability of the lens 101 can be improved.

[0126] In addition, the UV absorber does not have to be implemented with only inorganic components, and may also include organic materials.

[0127] Since the UV absorber includes more organic materials, the absorbable UV wavelength band can be broadened, thereby further improving the UV absorption efficiency.

[0128] Examples of organic materials that may be included in the UV absorber include benzophenone, oxalic acid anilide, benzotriazole, triazine, and each material has advantages such as low cost (benzophenone), low discoloration (oxalic acid anilide), and high absorbance (benzotriazole and triazine).

[0129] On the other hand, the antioxidant and the hindered amine light stabilizer may include inorganic particles and organic materials similar to those included in the above-mentioned UV absorber, and a detailed description will be omitted to avoid repetition.

[0130] In addition, considering the function of the functional coating, the thickness of the functional coating may be thinner than the thickness of the waterproof layer 120 .

[0131] Here, the thickness of the functional coating can be measured using non-destructive testing or destructive testing.

[0132] Figures 5 to 23 are cross-sectional views showing various embodiments of the AR coating of the present disclosure.

[0133] In the following, reference will be made to Figures 5 to 23 Various embodiments of AR coatings are described.

[0134] Figure 5 and Figure 6 is a cross-sectional view showing that an AR coating is formed by alternately stacking an oxide-based material and a nitride-based material.

[0135] like Figure 5 As shown in , the AR coating 220 of the lens has a structure in which first layers 201 and third layers 203 are alternately stacked, the first layer 201 being a low refractive index layer and formed of an oxide-based material, and the third layer 203 being a high refractive index layer and formed of a nitride-based material.

[0136] Reference Figure 6 , the AR coating 221 of the lens has a structure in which the second layer 202 and the fourth layer 204 are alternately stacked, the second layer 202 is a high refractive index layer and is formed of an oxide-based material, and the fourth layer 204 is a low refractive index layer and is formed of a nitride-based material.

[0137] Figure 7 and Figure 8 is a cross-sectional view showing that an AR coating is formed by alternately stacking an oxide-based material and a nitride-based material and disposing the nitride-based material on the uppermost end thereof.

[0138] Reference Figure 7 , the AR coating 230 of the lens is configured by alternately stacking the fourth layer 204, which is a low refractive index layer and is formed of a nitride-based material, and the second layer 202, which is a high refractive index layer and is formed of an oxide-based material. The third layer 203 (a high refractive index layer formed of a nitride-based material) is disposed on the second layer 202 at its uppermost end.

[0139] Reference Figure 8, the AR coating 231 of the lens is configured by alternately stacking a first layer 201, which is a low refractive index layer and is formed of an oxide-based material, and a third layer 203, which is a high refractive index layer and is formed of a nitride-based material. The fourth layer 204 (a low refractive index layer formed of a nitride-based material) is disposed on the first layer 201 at its uppermost end.

[0140] Fig. 9 and Fig.10 is a cross-sectional view showing an AR coating, which is configured by alternately stacking an oxide-based material and a nitride-based material and stacking two or more layers of a nitride-based material at the uppermost end thereof.

[0141] Reference Fig. 9 The AR coating 240 of the lens has a structure in which a first layer 201, which is a low refractive index layer formed of an oxide-based material, and a third layer 203, which is a high refractive index layer formed of a nitride-based material, are alternately stacked. The third layer 203 and a fourth layer 204, which is a nitride-based low refractive index layer, are alternately stacked at their uppermost ends.

[0142] Reference Fig.10 The AR coating 241 of the lens has a structure in which the second layer 202 is a high refractive index layer formed of an oxide-based material and the fourth layer 204 is a low refractive index layer formed of a nitride-based material and is alternately stacked. The third layer 203 and the fourth layer 204 are alternately stacked at least once at the uppermost end of the AR coating 241.

[0143] according to Fig. 9 and Fig.10 The structure can further improve the hardness of the lens.

[0144] Fig.11 and Fig.12 is a cross-sectional view showing that the AR coating has a thick layer formed of a nitride-based material disposed in a middle portion thereof.

[0145] Reference Fig.11 , the AR coating 250 of the lens is configured so that the first layer 201 and the second layer 202 are alternately stacked from its lower end, and the third layer 203 (high refractive index layer) is arranged on the first layer 201 (low refractive index layer) in its middle part. In this case, the third layer 203 is arranged to be relatively thicker than the first layer 201 and the second layer 202.

[0146] Reference Fig.12, the AR coating 251 of the lens is configured such that the first layer 201 and the second layer 202 are alternately stacked from the lower end thereof, and the fourth layer 204 (low refractive index layer) is disposed on the second layer 202 (high refractive index layer) in the middle portion thereof. In this case, the fourth layer 204 is relatively thicker than the first layer 201 and the second layer 202.

[0147] In this way, when the middle portion of the AR coating is formed of a thicker nitride-based material, these third layers 203 or fourth layers 204 can serve as a matrix to further improve the overall hardness of the lens.

[0148] Figures 13 to 16 , Fig.19 and Fig. 20 is a cross-sectional view showing that the AR coating has a thick layer formed of a nitride-based material in a middle portion thereof and a layer formed of a nitride-based material is disposed at an uppermost end thereof.

[0149] Reference Fig.13 , the AR coating 260 of the lens is configured such that the first layer 201 and the second layer 202 are alternately stacked from the lower end thereof, and the third layer 203 (high refractive index layer) is disposed on the first layer 201 (low refractive index layer) in the middle portion thereof. In this case, the third layer 203 is relatively thicker than the first layer 201 and the second layer 202.

[0150] In addition, the third layer 203 (a high refractive index layer formed of a nitride-based material) is disposed on the first layer 201 at the uppermost end of the AR coating 260 .

[0151] Reference Fig.14 , the AR coating 261 of the lens is configured such that the first layer 201 and the second layer 202 are alternately stacked from the lower end thereof, and the fourth layer 204 (low refractive index layer) is disposed on the second layer 202 (high refractive index layer) in the middle portion thereof. In this case, the fourth layer 204 is disposed to be relatively thicker than the first layer 201 and the second layer 202.

[0152] In addition, the fourth layer 204 (a low refractive index layer formed of a nitride-based material) is provided on the first layer 201 at the uppermost end of the AR coating 261 .

[0153] Reference Fig.15 , the AR coating 270 of the lens is configured such that the first layer 201 and the second layer 202 are alternately stacked from the lower end thereof, and the fourth layer 204 (low refractive index layer) is disposed on the second layer 202 (high refractive index layer) in the middle portion thereof. In this case, the fourth layer 204 is disposed to be relatively thicker than the first layer 201 and the second layer 202.

[0154] In addition, the third layer 203 (a high refractive index layer formed of a nitride-based material) is disposed on the first layer 201 at the uppermost end of the AR coating 270 .

[0155] Reference Fig.16 , the AR coating 271 of the lens is configured such that the first layer 201 and the second layer 202 are alternately stacked from the lower end thereof, and the fourth layer 204 (low refractive index layer) is disposed on the second layer 202 (high refractive index layer) in the middle portion thereof. In this case, the fourth layer 204 is disposed to be relatively thicker than the first layer 201 and the second layer 202.

[0156] In addition, the fourth layer 204 (a low refractive index layer formed of a nitride-based material) is provided on the first layer 201 at the uppermost end of the AR coating 271 .

[0157] Fig.19 AR coating 290 and Fig.17 The AR coating 280 shown in FIG. 2 is similar and has a thicker fourth layer 204 disposed on the second layer 202 in a middle portion thereof.

[0158] Fig. 20 AR coating 291 with Fig.18 The AR coating 281 shown in FIG. 2 is similar and has a thicker fourth layer 204 disposed on the second layer 202 in a middle portion thereof.

[0159] Fig.17 and Fig.18 is a cross-sectional view showing that the AR coating has a thick layer formed of a nitride-based material at a middle portion thereof, and two or more layers formed of a nitride-based material are stacked at an uppermost end thereof.

[0160] Fig.17 The AR coating 280 is configured so that Fig.13 In the structure of the AR coating shown in , the fourth layer 204 (a low refractive index layer and formed of a nitride-based material) is provided on the third layer 203 at the uppermost end thereof.

[0161] Fig.18 The AR coating 281 in the embodiment is configured such that Fig.14 In the structure of the AR coating shown in , the third layer 203 (a high refractive index layer and formed of a nitride-based material) is disposed on the fourth layer 204 at its uppermost end.

[0162] Figure 21 to Figure 23 An AR coating composed of a nitride based material is shown.

[0163] Reference Fig.21, the AR coating 300 of the lens has a structure in which the fourth layer 204 and the third layer 203 are alternately stacked from the lower end thereof.

[0164] Reference Fig. 22 , the AR coating 310 of the lens has the following structure: Fig.21 In the structure of FIG. 2 , the third layer 203 ′ which is thicker than the other third layers 203 and the fourth layer 204 is disposed in the middle portion thereof.

[0165] Reference Fig.23 , the AR coating 320 of the lens has the following structure: Fig.21 In the structure of FIG. 2 , a fourth layer 204 ′ thicker than the other third layer 203 and fourth layer 204 is disposed in a middle portion thereof.

[0166] As the use of lenses diversifies, the need for proper protection of lenses from the external environment is increasing. In cases where the lenses are always exposed to the outside, like vehicle cameras for electronic components, this need is further increased.

[0167] like Fig.35 As shown in , the lens assembly of the electronic camera may include a plurality of lenses 610 , 620 , 630 , 640 , 650 , 660 , and 670 , an IR cut filter 680 , a cover glass 690 , and a PCB board 700 .

[0168] In this case, according to an exemplary embodiment of the present disclosure, a lens structure including an AR coating and a waterproof layer may be applied to the lens 610 disposed at the front thereof.

[0169] Aspects of the present disclosure provide a lens capable of preventing contamination and scratches caused by an external environment by increasing hardness while improving an anti-reflection effect.

[0170] Although specific examples have been shown and described above, it will be apparent after understanding the present disclosure that various changes in form and detail may be made in these examples without departing from the spirit and scope of the claims and their equivalents. The examples described herein are considered to be illustrative only and not for limiting purposes. The description of the features or aspects in each example is considered to be applicable to similar features or aspects in other examples. Suitable results may also be obtained if the described techniques are performed in a different order, and / or if the components in the described systems, architectures, devices, or circuits are combined in different ways and / or replaced or supplemented by other components or their equivalents. Therefore, the scope of the present disclosure is not limited by specific embodiments, but by the claims and their equivalents, and all changes within the scope of the claims and their equivalents will be interpreted as included in the present disclosure.

Claims

1. A lens comprising: Lens part; a multi-layer anti-reflection coating including one or both of a low refractive index layer and a high refractive index layer and disposed on one surface of the lens portion; as well as a waterproof layer, comprising a water-repellent and disposed on one surface of the multi-layer anti-reflective coating, Wherein, one or both of the low refractive index layer and the high refractive index layer are formed of a nitride-based material having a band gap greater than 3.1 eV.

2. The lens according to claim 1, wherein: The low refractive index layer includes a first layer formed of SiO2, and The high refractive index layer includes a second layer formed of TiO2.

3. The lens according to claim 1, wherein: The low refractive index layer includes a fourth layer formed of a nitride-based material, and The high refractive index layer includes a third layer formed of a nitride-based material.

4. The lens according to claim 3, wherein: The fourth layer is formed of TiN, and the third layer is formed of Si 3 N 4 or AlN.

5. The lens according to claim 4, wherein: The thickness of the fourth layer is 50 nm or less.

6. The lens according to claim 1, wherein: The low refractive index layer includes a first layer formed of SiO2 and a fourth layer formed of a nitride-based material, and The high refractive index layer includes a second layer formed of TiO 2 and a third layer formed of a nitride-based material.

7. The lens according to claim 6, wherein: In the multi-layer anti-reflection coating, the first layer and the second layer are alternately stacked, and the uppermost portion of the multi-layer anti-reflection coating is the third layer or the fourth layer.

8. The lens according to claim 1, wherein: The low refractive index layer includes a first layer formed of SiO2, and The high refractive index layer includes a third layer formed of a nitride-based material.

9. The lens according to claim 8, wherein: On the first layer at the uppermost end of the multi-layer anti-reflection coating, one or both of the third layer and the fourth layer are further provided as one or more layers, and the fourth layer is a low refractive index layer formed of a nitride-based material.

10. The lens according to claim 1, wherein: The low refractive index layer includes a fourth layer formed of a nitride-based material, and The high refractive index layer includes a second layer formed of TiO2.

11. The lens according to claim 10, wherein: On the second layer at the uppermost end of the multi-layer anti-reflection coating, one or both of the fourth layer and the third layer are further provided as one or more layers, and the third layer is a high refractive index layer formed of a nitride-based material.

12. The lens according to claim 1, wherein: In the multilayer anti-reflection coating, first layers and second layers are alternately stacked, and a third layer having a high refractive index or a fourth layer having a low refractive index formed of a nitride-based material is disposed in a middle portion of the multilayer anti-reflection coating.

13. The lens according to claim 12, wherein: The third layer or the fourth layer is formed to be thicker than the first layer and the second layer.

14. The lens according to claim 12, wherein: One or both of the third layer and the fourth layer are also provided at the uppermost end of the multi-layer anti-reflection coating as one or more layers.

15. The lens according to claim 1, further comprising: A functional coating includes a UV improving additive and is disposed between the multi-layer anti-reflective coating and the water-resistant layer.

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