Lens and manufacturing method therefor

Abstract

A lens according to an embodiment comprises: a substrate, and an anti-reflection film deposited on the substrate, wherein the anti-reflection film includes a plurality of low refractive index layers and a plurality of high refractive index layers disposed between the low refractive index layers, an average stress of the high refractive index layers is 24 MPa to 40 M, and an average stress of the low refractive index layers is −99.44 MPa to −76.56 MPa.

Description

Lenses and methods for manufacturing the same

[0001] The present invention relates to a lens and a method for manufacturing the same.

[0002] Conventional vehicles are equipped with Advanced Driver Assistance Systems (ADAS) to supplement the driver's cognitive, judgment, and operational capabilities and support safe driving. ADAS utilizes various sensors, including cameras, radar, LiDAR, and ultrasonic sensors, to perceive the surrounding environment and alert the driver or automatically control the vehicle.

[0003] In particular, surround-view cameras, which detect a vehicle's surroundings, are equipped with optical components that capture light. These optical components include lenses, and advancements in plastic materials and molding technology have enabled the use of plastic substrates, which offer greater design freedom and mass production potential even in the harsh temperature environments of automotive applications.

[0004] However, to maintain optical performance, an optical functional film (hereinafter referred to as an anti-reflection film) must be formed on the lens surface. Since the coefficient of linear expansion of plastic substrates is in the single digits, high temperatures generate strong stress on the anti-reflection film, leading to microcracks or peeling, resulting in performance-related issues such as ghosting, flare, and MTF degradation.

[0005] The technical problem of the present invention is to provide a lens that can prevent micro cracks or peeling occurring in an anti-reflection film in a high temperature and high humidity environment.

[0006] A lens according to an embodiment includes a substrate, an antireflection film deposited on the substrate, the antireflection film including a plurality of low refractive index layers and a plurality of high refractive index layers each disposed between adjacent low refractive index layers, and an average stress of the plurality of high refractive index layers may be 24 MPa to 40 MPa, and an average stress of the plurality of low refractive index layers may be -99.44 MPa to -76.56 MPa.

[0007] In addition, the anti-reflection film includes a first layer disposed on the substrate, a second layer disposed on the first layer, a third layer disposed on the second layer, a fourth layer disposed on the third layer, a fifth layer disposed on the fourth layer, a sixth layer disposed on the fifth layer, and a seventh layer disposed on the sixth layer, wherein the first layer, the third layer, the fifth layer, and the seventh layer form the low refractive index layer, and the second layer, the fourth layer, and the sixth layer form the high refractive index layer.

[0008] Additionally, the sum of the thicknesses of the high refractive index layers may be 25% or less of the thickness (D) of the anti-reflection film.

[0009] Additionally, the thickness of the seventh layer may be 0.71λ nm or more.

[0010] In addition, the high refractive index layer can be formed using TiO2 ion-assisted deposition, and the low refractive index layer can be formed using SiO2 ion-assisted deposition.

[0011] Additionally, the thickness of the anti-reflection film may be 350 nm or less.

[0012] Additionally, the thickness of each of the first to seventh layers may be 10 nm to 150 nm.

[0013] A method for manufacturing a lens according to an embodiment of the present invention includes a step of forming an anti-reflection film by fixing a substrate to an ion-assisted deposition device, wherein the step of forming the anti-reflection film includes repeating the steps of depositing a first low-refractive-index layer on the substrate, depositing a first high-refractive-index layer on the first low-refractive-index layer, and sequentially depositing a second low-refractive-index layer and a second high-refractive-index layer on the first high-refractive-index layer, and the ion source output of the ion-assisted deposition device can be controlled so that the first and second low-refractive-index layers form a compressive stress and the first and second high-refractive-index layers form a tensile stress.

[0014] In addition, the first and second low refractive index layers can be deposited by setting the ion source output of the ion assisted deposition device to 320 W, and the first and second high refractive index layers can be deposited by setting the ion source output of the ion assisted deposition device to 240 W.

[0015] Additionally, when depositing the first and second high refractive index layers and the first and second low refractive index layers, the substrate surface temperature may be 80°C to 110°C.

[0016] According to an embodiment of the present invention, by controlling the ion source output of the ion assist deposition device, the stress of the high refractive index layer and the low refractive index layer of the lens can be controlled.

[0017] In addition, according to an embodiment of the present invention, micro cracks or peeling may not occur even in a high temperature, high humidity environment.

[0018] Figure 1 illustrates a lens (10) according to one embodiment of the present invention.

[0019] Figure 2 is an example diagram of an ion-assisted deposition (IAD) device.

[0020] Figure 3 is a table showing the ion source output of each layer of the ion assist deposition device in a comparative example.

[0021] Figure 4 is a table showing whether the anti-reflection film of the comparative example passed the test conditions in a high temperature and high humidity environment.

[0022] Figure 5 is a table comparing examples and comparative examples according to the ion source output conditions of the ion assist deposition device.

[0023] Figure 6 is a table comparing the thickness of each layer between the example and the comparative example.

[0024] Figure 7 shows the stress of an anti-reflection film according to an embodiment of the present invention.

[0025] Figure 8 is a graph showing the average stress of the high refractive index layer of the examples and comparative examples according to the film forming conditions.

[0026] Figure 9 shows the average stress of the low refractive index layer of the embodiment and comparative example according to the film forming conditions.

[0027] Figure 10 is a graph showing the total stress of the antireflection film of the comparative example and the embodiment.

[0028] Figure 11 is a table showing whether the implementation and comparative examples passed the test conditions in a high temperature, high humidity environment.

[0029] Figure 12 is a graph comparing the reflectance of a comparative example and an exemplary embodiment.

[0030] Hereinafter, embodiments disclosed in the present specification will be described in detail with reference to the attached drawings. The suffixes "module" and "part" used in the following description for components are given or used interchangeably for the sake of ease of writing the specification, and do not in themselves have distinct meanings or roles. In addition, the attached drawings are intended to facilitate easy understanding of the embodiments disclosed in the present specification, and the technical ideas disclosed in the present specification are not limited by the attached drawings. In addition, when an element such as a layer, region, or substrate is referred to as existing "on" another element, this includes that it may be directly on the other element, or that other intermediate elements may exist therebetween.

[0031]

[0032] FIG. 1 illustrates a lens (10) according to one embodiment of the present invention, and FIG. 2 is an exemplary diagram of an ion-assisted deposition (IAD) device.

[0033] The above lens (10) may include a substrate (100) and an anti-reflection film (200).

[0034] The above-described substrate (100) comprises a general plastic material used for optical lenses and can be formed into a predetermined lens shape. The plastic material may, for example, be a material having a refractive index (nD) in the range of 1.50 to 1.74. Examples of such plastic materials include allyl diglycol carbonate, urethane-based resins, polycarbonate, cyclic (poly) olefin-based resins, polyester-based resins, thiourethane-based resins, and episulfide resins.

[0035] The above anti-reflection film (200) may be formed on the surface of the substrate (100). The anti-reflection film (200) may have a multilayer structure in which material films having different refractive indices are laminated. The anti-reflection film (200) is a film that prevents reflection of light by interference. The anti-reflection film (200) may be a multilayer film formed by alternately laminating low-refractive index layers and high-refractive index layers. For example, the low-refractive index layers (210, 230, 250, 270) may be formed of silicon dioxide (SiO2) having a refractive index of approximately 1.43 to 1.47. In addition, the high refractive index layer (220, 240, 260) may be formed of a material having a higher refractive index than the low refractive index layer (210, 230, 250, 270). For example, the high refractive index layer (220, 240, 260) may be formed by mixing at least one metal oxide among niobium oxide (Nb2O5), tantalum oxide (Ta2O5), titanium oxide (TiO2), zirconium oxide (ZrO2), yttrium oxide (Y2O3), and aluminum oxide (Al2O3).

[0036] The number of layers of the anti-reflection film (200) formed by the low refractive index layers (210, 230, 250, 270) and the high refractive index layers (220, 240, 260) is not limited. According to one embodiment of the present invention, the anti-reflection film (200) may be formed by sequentially stacking seven layers from the substrate (100): a first layer (210), a second layer (220), a third layer (230), a fourth layer (240), a fifth layer (250), a sixth layer (260), and a seventh layer (270). Each of the first to seventh layers may be defined as a thin film. According to an embodiment of the present invention, each of the low refractive index layers (210, 230, 250, 270) and the high refractive index layers (220, 240, 260) may have a film thickness according to each refractive index so as to have a predetermined phase difference.

[0037] Referring to FIG. 2, an ion-assisted deposition device (1000) for forming an anti-reflection film (200) of the present invention may include a chamber (1010), an ion source (1020), a neutralizer (1030), a deposition source (1040), and a holder (1050).

[0038] The interior of the above chamber (1010) can be maintained in a vacuum state when depositing the anti-reflection film (200).

[0039] The ion source (1020), the neutralizer (1030), the deposition source (1040), and the holder (1050) may be located within the chamber (1010).

[0040] The ion source (1020) can create a plasma state in which a neutral gas is mixed with positive and negative charges, and can generate an ion beam using the neutralizer (1030). The neutralizer (1030) can be used as a neutralizing electron gun to vaporize a thin film material while simultaneously depositing ions generated from the ion source (1020) on the substrate (100). Generally, the ion source (1020) can generate a beam voltage of 300 V to 600 V and a beam current of 300 mA to 1 A.

[0041] The above deposition source (1040) is a thin film material to be deposited, which can be evaporated to create atoms or molecules. The deposition source (1040) may include TiO2 and SiO2. For example, when depositing the high refractive index layer, TiO2 may be used, and when depositing the low refractive index layer, SiO2 may be used.

[0042] The above substrate (100) is placed on the holder (1050), heated by the ion beam, and a deposition source or ions can be condensed on the surface of the substrate (100) to form a thin film.

[0043] In general, in a general vacuum deposition method that does not involve ion assistance, since the energy of the particles reaching the substrate (100) is low, the density of the layer of the anti-reflection film formed on the substrate is low, so tensile stress is likely to be generated. On the other hand, in an ion assist deposition (IAD) method that involves ion assistance, since the ion energy of the particles reaching the substrate (100) is high, it is difficult for tensile stress to be generated in the anti-reflection film. In other words, compressive stress can be generated in the anti-reflection film.

[0044] In an embodiment of the present invention, by controlling the ion source output of an ion-assisted deposition device, the stress of a low-refractive index layer and a high-refractive index layer can be controlled, thereby providing an anti-reflection film (200) that does not crack or peel in high-temperature and high-humidity environments. This will be described in detail later.

[0045]

[0046] Referring again to FIG. 1, the first layer (210) is the lowermost layer of the anti-reflection film (200) and may be a low-refractive-index layer. The first layer (210) may be formed using a material including an organic silicon compound. For example, the first layer (210) may be formed of SiO2. The first layer (210) may have a refractive index close to the refractive index of the substrate (100). The first layer (210) may have a first thickness (d1), and the first thickness (d1) may be formed in a range of 10 to 150 nm.

[0047] The second layer (220) is disposed on the first layer (210) and may be a high refractive index layer. For example, the second layer (220) may be formed by depositing TiO2. The second layer (220) may have a second thickness (d2), and the second thickness (d2) may be formed in a range of 10 to 150 nm.

[0048] The third layer (230) is disposed on the second layer (220) and may be a low refractive index layer. The third layer (230) may be formed using a material including an organosilicon compound. For example, the third layer (230) may be formed of SiO2. The third layer (230) may have a third thickness (d3), and the third thickness (d3) may be formed in a range of 10 to 150 nm.

[0049] The fourth layer (240) is disposed on the third layer (230) and may be a high refractive index layer (220, 240, 260). For example, the fourth layer (240) may be formed by depositing TiO2. The fourth layer (240) may have a fourth thickness (d4), and the fourth thickness (d4) may be formed in a range of 10 to 150 nm.

[0050] The fifth layer (250) is disposed on the fourth layer (240) and may be a low refractive index layer. The fifth layer (250) may be formed using a material including an organosilicon compound. For example, the fifth layer (250) may be formed of SiO2. The fifth layer (250) may have a fifth thickness (d5), and the fifth thickness (d5) may be formed in a range of 10 to 150 nm.

[0051] The sixth layer (260) is disposed on the fifth layer (250) and may be a high refractive index layer. For example, the sixth layer (260) may be formed by depositing TiO2. The sixth layer (260) may have a sixth thickness (d6), and the sixth thickness (d6) may be formed in a range of 10 to 150 nm.

[0052] The seventh layer (270) is disposed on the fifth layer (250) and may be a low refractive index layer. The seventh layer (270) may be formed using a material including an organosilicon compound. For example, the seventh layer (270) may be formed of SiO2. The seventh layer (270) may have a seventh thickness (d7). The seventh layer (270) may be the outermost layer of the anti-reflection film (200). The seventh thickness (d7) may be formed to be 0.71 λnm or more. By forming the thickness of the seventh layer (270) to be 0.71 λnm or more, moisture resistance may be improved, and the seventh thickness (d7) may be formed in a range of 10 to 150 nm.

[0053] The thickness (D) of the anti-reflection film (200) according to an embodiment of the present invention, i.e., the sum of the first to seventh thicknesses (d1+d2+d3+d4+d5+d6+d7), may be 350 nm or less. If the thickness of the anti-reflection film (200) exceeds 350 nm, a problem of reduced transmittance of the anti-reflection film (200) may occur.

[0054] In addition, the sum of the thicknesses of the high refractive index layers (220, 240, 260) may be formed to be 25% or less of the thickness (D) of the anti-reflection film. As a result, the overall stress of the anti-reflection film (200) may be formed as compressive stress. This will be described in detail later.

[0055]

[0056] Figure 3 is a table showing the ion source output of each layer of the ion assist deposition device in a comparative example, and Figure 4 is a table showing whether the antireflection film of the comparative example passed the test conditions in a high temperature and high humidity environment.

[0057] Referring to FIGS. 3 and 4, Comparative Examples 1 to 4 are experimental examples according to conventional internal technology.

[0058] The thickness of each layer in Comparative Examples 1 to 4 was measured under the same conditions as 0.36 λ.

[0059] The radiation prevention film according to Comparative Example 1 is deposited with the ion source output of the ion assist deposition device set to 0 W on the first, third, fifth, and seventh layers (210, 230, 250, 270), that is, a low refractive index layer is formed only by using a vacuum deposition method without using an ion assist deposition method. In addition, in Comparative Example 1, a high refractive index layer is formed only by depositing with the ion source output of the ion assist deposition device set to 320 W on the second, fourth, and sixth layers (220, 240, 260).

[0060] At this time, the anti-reflection film formed under the experimental conditions of Comparative Example 1 did not crack when left in a high temperature environment of 135˚C for 1000 hours, but cracks occurred when left in a high temperature and high humidity environment of 85˚C / 85% for 1000 hours, and thus did not pass the test conditions.

[0061] According to Comparative Example 2, the antireflection film is deposited by setting the ion source output of the ion-assisted deposition device to 320 W for the first, third, fifth, and seventh layers (210, 230, 250, 270) to form a low-refractive-index layer, and the second, fourth, and sixth layers (220, 240, 260) to form a high-refractive-index layer by using only the vacuum deposition method without using the ion-assisted deposition method, that is, setting the ion source output of the ion-assisted deposition device to 0 W. The antireflection film formed under the experimental conditions of Comparative Example 2 did not crack when left for 1,000 hours in a high-temperature, high-humidity environment of 85˚C / 85%, but cracks occurred when left for 1,000 hours in a high-temperature environment of 135˚C and did not pass the test conditions.

[0062] The antireflection film according to Comparative Example 3 is an antireflection film (200) formed by a general vacuum deposition method, without forming all of the first to seventh layers (d1 to d7) by an ion-assisted deposition method. The antireflection film formed under the experimental conditions of Comparative Example 3 did not crack when left in a high temperature and high humidity environment of 85˚C / 85% for 1000 hours, but cracks occurred when left in a high temperature environment of 135˚C for 1000 hours, failing to pass the test conditions.

[0063] The antireflection film according to Comparative Example 4 is an antireflection film (200) formed by setting the ion source output of the ion-assisted deposition device to 320 W for all of the first to seventh layers (d1 to d7). The antireflection film formed under the experimental conditions of Comparative Example 4 did not crack when left in a high-temperature environment of 135˚C for 1000 hours, but cracks occurred when left in a high-temperature, high-humidity environment of 85˚C / 85% for 1000 hours, failing to pass the test conditions.

[0064] Therefore, simply applying the ion-assisted deposition method cannot solve the problems of the prior art. According to the research results, it was determined that the cause of the micro cracks or peeling occurring in the anti-reflection film (200) is that a strong tensile stress is applied to the thin film due to the difference in expansion rates of each layer that occurs in a high-temperature environment. That is, in order to solve this, it is necessary to form the overall stress of the anti-reflection film (200) into a compressive stress by adjusting the ion source output of the ion-assisted deposition device. However, even if the overall stress of the anti-reflection film is formed as a compressive stress that is too strong, cracks and peeling may occur, and therefore, in the embodiment of the present invention, the stress formed by the low-refractive-index layer and the high-refractive-index layer was adjusted differently to solve this problem.

[0065] FIG. 5 is a table comparing examples and comparative examples according to the ion source output conditions of the ion-assisted deposition device, FIG. 6 is a table comparing the thicknesses of each layer of examples and comparative examples, FIG. 7 shows the stress of an anti-reflection film (200) according to an example of the present invention, FIG. 8 is a graph showing the average stress of the high refractive index layer of examples and comparative examples according to the deposition conditions, FIG. 9 is a graph showing the average stress of the low refractive index layer of examples and comparative examples according to the deposition conditions, FIG. 10 is a graph showing the total stress of the anti-reflection films of examples and comparative examples, FIG. 11 is a table showing whether examples and comparative examples passed the test conditions in a high temperature, high humidity environment, and FIG. 12 is a graph comparing the reflectance of examples and comparative examples.

[0066] First, referring to FIG. 7, the anti-reflection film (200) according to the embodiment and comparative example of the present invention can form a first stress (σ1) in the first layer (210) through a deposition process, a second layer (220) can form a second stress (σ2), a third layer (230) can form a third stress (σ3), a fourth layer (240) can form a fourth stress (σ4), a fifth layer can form a fifth stress (σ5), a sixth layer can form a sixth stress (σ6), and a seventh layer can form a seventh stress (σ7).

[0067]

[0068] (Comparative Example 5)

[0069] The antireflection film of Comparative Example 5 was deposited by setting the ion source output of the ion-assisted deposition device to 320 W for the low-refractive index layer (210, 230, 250, 270), and by setting the ion source output of the ion-assisted deposition device to 160 W for the high-refractive index layer (220, 240, 260).

[0070] The first layer (210) according to Comparative Example 5 is formed with a thickness of 0.35 (λ / 4) under the conditions of a deposition temperature of 100˚C or less and a deposition rate of 0.3 nm / s in an ion-assisted deposition device, the second layer (220) is formed with a thickness of 0.12 (λ / 4) under the conditions of a deposition temperature of 100˚C or less and a deposition rate of 0.6 nm / s in an ion-assisted deposition device, the third layer (230) is formed with a thickness of 0.29 (λ / 4) under the conditions of a deposition temperature of 100˚C or less and a deposition rate of 0.3 nm / s in an ion-assisted deposition device, the fourth layer (240) is formed with a thickness of 0.33 (λ / 4) under the conditions of a deposition temperature of 100˚C or less and a deposition rate of 0.6 nm / s in an ion-assisted deposition device, and the fifth layer (250) is formed with a thickness of 0.33 (λ / 4) under the conditions of a deposition temperature of 100˚C or less and a deposition rate of 0.6 nm / s in an ion-assisted deposition device. The first layer (260) is formed with a thickness of 0.15 (λ / 4) under the conditions of a deposition temperature of 100˚C or less and a deposition speed of 0.3 nm / s, the sixth layer (260) is formed with a thickness of 0.26 (λ / 4) under the conditions of a deposition temperature of 100˚C or less and a deposition speed of 0.6 nm / s in an ion-assisted deposition device, and the seventh layer (270) is formed with a thickness of 0.71 (λ / 4) under the conditions of a deposition temperature of 100˚C or less and a deposition speed of 0.3 nm / s in an ion-assisted deposition device. The average stress (σ) of the low-refractive-index layer in Comparative Example 5 L ) forms a true stress of -88 MPa, i.e., a compressive stress, and the average stress (σ) of the high refractive index layer H ) forms a true stress of 103 MPa, i.e., a compressive stress.

[0071] In Comparative Example 5, when the wavelength (λ) is 550 nm, the total stress (σ) of the antireflection film T ) formed -27 MPa. Therefore, the overall stress of the anti-reflection film according to Comparative Example 5 formed a compressive stress, but in a high-temperature environment of 125°C and 2000 hours, the tensile stress due to the expansion of the anti-reflection film (200) was strongly applied, causing cracks and peeling.

[0072]

[0073] (Comparative Example 6)

[0074] Referring to FIGS. 5 to 10, as described above, the anti-reflection film of Comparative Example 6 is a high-refractive index layer and a low-refractive index layer deposited by setting the ion source output of the ion-assisted deposition device to 320 W for all of the first to seventh layers (d1 to d7).

[0075] The first layer (210) according to Comparative Example 6 is formed with a thickness of 0.37 (λ / 4) under the conditions of a deposition temperature of 100˚C or less and a deposition rate of 0.3 nm / s in an ion-assisted deposition device, the second layer (220) is formed with a thickness of 0.09 (λ / 4) under the conditions of a deposition temperature of 100˚C or less and a deposition rate of 0.6 nm / s in an ion-assisted deposition device, the third layer (230) is formed with a thickness of 0.36 (λ / 4) under the conditions of a deposition temperature of 100˚C or less and a deposition rate of 0.3 nm / s in an ion-assisted deposition device, the fourth layer (240) is formed with a thickness of 0.21 (λ / 4) under the conditions of a deposition temperature of 100˚C or less and a deposition rate of 0.6 nm / s in an ion-assisted deposition device, and the fifth layer (250) is formed with a thickness of 0.21 (λ / 4) under the conditions of a deposition temperature of 100˚C or less and a deposition rate of 0.6 nm / s in an ion-assisted deposition device. The first layer (260) is formed with a thickness of 0.25 (λ / 4) under conditions of a deposition temperature of 100˚C or less and a deposition speed of 0.3 nm / s, the sixth layer (260) is formed with a thickness of 0.18 (λ / 4) under conditions of a deposition temperature of 100˚C or less and a deposition speed of 0.6 nm / s in an ion-assisted deposition device, and the seventh layer (270) is formed with a thickness of 0.76 (λ / 4) under conditions of a deposition temperature of 100˚C or less and a deposition speed of 0.3 nm / s in an ion-assisted deposition device.

[0076]

[0077] Average stress (σ) of the low refractive index layer in Comparative Example 6 L ) forms a true stress of -88 MPa, i.e., a compressive stress, and the average stress (σ) of the high refractive index layer H ) forms a true stress of -250Mpa, i.e., a compressive stress. Here, a stress forming a negative value means that it is a compressive stress, and a stress forming a positive value means that it is a tensile stress.

[0078] Stress in each layer (σ n , n is an integer) can be calculated by multiplying the thickness of each layer (dn, n is an integer) by the intrinsic stress of each layer. Here, the total stress of the antireflection film (σ T ) can be calculated by dividing the total stress of the low refractive index layer and the total stress of the high refractive index layer by the total thickness (D).

[0079] σ T ={(d1* σ1)+ (d2* σ2)+ (d3* σ3)+ (d4* σ4)+ (d5* σ5)+ (d6* σ6)+ (d7* σ7)} / D

[0080] In Comparative Example 6, when the wavelength (λ) is 550 nm, the total stress (σ) of the antireflection film T ) formed -122 Mpa. Therefore, the total stress of the anti-reflection film according to Comparative Example 6 forms a compressive stress, but there is a problem that cracks and peeling occur due to excessive compressive stress compared to the expansion rate applied to the anti-reflection film in a high-temperature environment of 125℃ and 2000 hours.

[0081]

[0082] (Example)

[0083] The antireflection film (200) according to the embodiment of the present invention can be deposited by setting the ion source output of the ion assist deposition device to 320 W for the low refractive index layer (210, 230, 250, 270), and by setting the ion source output of the ion assist deposition device to 240 W for the high refractive index layer (220, 240, 260).

[0084] The first layer (210) according to the embodiment is formed with a thickness of 0.38(λ) under the conditions of a deposition temperature of 100˚C or less and a deposition rate of 0.3 nm / s in an ion-assisted deposition device, the second layer (220) is formed with a thickness of 0.09(λ) under the conditions of a deposition temperature of 100˚C or less and a deposition rate of 0.6 nm / s in an ion-assisted deposition device, the third layer (230) is formed with a thickness of 0.36(λ) under the conditions of a deposition temperature of 100˚C or less and a deposition rate of 0.3 nm / s in an ion-assisted deposition device, the fourth layer (240) is formed with a thickness of 0.21(λ) under the conditions of a deposition temperature of 100˚C or less and a deposition rate of 0.6 nm / s in an ion-assisted deposition device, and the fifth layer (250) is formed with a thickness of 0.21(λ) under the conditions of a deposition temperature of 100˚C or less and a deposition rate of 0.6 nm / s in an ion-assisted deposition device. The first layer (260) may be formed with a thickness of 0.25(λ) under the condition of 0.3 nm / s, the sixth layer (260) may be formed with a thickness of 0.17(λ) under the condition of a deposition temperature of 100˚C or less and a deposition speed of 0.6 nm / s in an ion-assisted deposition device, and the seventh layer (270) may be formed with a thickness of 0.76(λ) under the condition of a deposition temperature of 100˚C or less and a deposition speed of 0.3 nm / s in an ion-assisted deposition device. However, the thickness of each layer according to the embodiment of the present invention is not limited thereto. The sum of the thicknesses of the high refractive index layers (220, 240, 260) may be formed with a thickness of 25% or less of the thickness (D) of the anti-reflection film.

[0085] The antireflection film (200) according to the embodiment is an average stress (σ) of the low refractive index layer (210, 230, 250, 270) under the conditions of 30˚C to 90˚C. L ) is formed in the range of -88MPa±13%, and the average stress (σ) of the high refractive index layer (220, 240, 260) H) can be formed in the range of 32 MPa±25%. For example, each of the low refractive index layers (210, 230, 250, 270) in the embodiment can form an intrinsic stress of -88 MPa on average, that is, a compressive stress, and each of the high refractive index layers (220, 240, 260) can form an intrinsic stress of 32 MPa on average, that is, a tensile stress. Therefore, the high refractive index layer and the low refractive index layer can be formed such that the tensile stress and the compressive stress act in opposite directions in each layer to cancel each other out.

[0086] In the embodiment, when the wavelength (λ) is 550 nm, the total stress (σ) of the antireflection film (200) T ) formed -62 MPa. The anti-reflection film (200) according to the embodiment did not crack or peel even under high temperature environmental conditions of 125°C and 2000 hours and high temperature and high humidity environmental conditions of 85°C and 85% humidity and 1000 periods.

[0087] According to an embodiment of the invention, by controlling the ion source output of the ion assisted deposition device (1000), the stress formed in the low refractive index layer (210, 230, 250, 270) and the high refractive index layer (220, 240, 260) can be controlled, and by optimizing the film formation conditions, heat resistance and moisture resistance can be effectively improved.

[0088] Referring to FIG. 12, the anti-reflection film (200) according to an embodiment of the present invention can have a reflectance of approximately 0.7% in a wavelength range of 550 nm. Therefore, the anti-reflection film according to the present invention has the effect of maintaining the function of an anti-reflection film while ensuring stability and reliability even in high temperature and high humidity environments.

[0089]

[0090] Although the above description focuses on examples, these are merely examples and are not intended to limit the examples. Those skilled in the art will appreciate that various modifications and applications not exemplified above are possible without departing from the essential characteristics of the present examples. For example, each component specifically shown in the examples can be modified and implemented. In addition, differences related to such modifications and applications should be interpreted as being included within the scope of the embodiments set forth in the appended claims.

[0091] [Explanation of symbols]

[0092] 10: Lens 100: Materials

[0093] 200: Anti-reflection coating 1000: Ion-assisted deposition device

[0094] The present invention can be mounted and used in optical systems such as cameras, radars, LiDARs, and ultrasonic sensors, and is applicable to a wide range of industrial fields, including autonomous vehicles, drones, industrial robots, smart city infrastructure, and security systems. In particular, the lens of the present invention offers advantages such as improved optical precision and enhanced environmental resistance even in high-temperature and high-humidity environments, making it highly commercially viable across industries.

Claims

1. Description; and Including an anti-reflection film deposited on the above substrate, The above anti-reflection film is, Multiple low refractive index layers and It comprises a plurality of high refractive index layers each disposed between adjacent low refractive index layers, The average stress of the above high-density layer is 24 MPa to 40 MPa, A lens having an average stress of the low refractive index layer of -99.44 MPa to -76.56 MPa.

2. In paragraph 1, The above anti-reflection film is, A first layer disposed on the above substrate; A second layer disposed on the first layer; A third layer disposed on the second layer; A fourth layer disposed on the third layer; A fifth layer disposed on the fourth layer; A sixth layer disposed on the fifth layer; and Including a seventh layer disposed on the sixth layer, The first layer, the third layer, the fifth layer and the seventh layer have the low refractive index layer, A lens having the second layer, the fourth layer and the sixth layer as the high refractive index layer.

3. In paragraph 2, A lens in which the sum of the thicknesses of the high refractive index layers is 25% or less of the thickness of the anti-reflection film.

4. In paragraph 2, A lens having a thickness of the seventh layer of 0.71 λnm or more.

5. In paragraph 2, The above high refractive index layer has TiO2, A lens having the above low refractive index layer made of SiO2.

6. In paragraph 2, A lens characterized in that the thickness of the anti-reflection film is 350 nm or less.

7. In paragraph 2, A lens wherein each of the first to seventh layers has a thickness of 10 nm to 150 nm.

8. A step of forming an anti-reflection film by fixing the substrate to an ion-assisted deposition device; The step of forming the above anti-reflection film is: A step of depositing a first low refractive index layer on the above substrate; A step of depositing a first high refractive index layer on the first low refractive index layer; and A step of sequentially depositing a second low-refractive-index layer and a second high-refractive-index layer on the first high-refractive-index layer; A method for manufacturing a lens in which the ion source output of the ion assisted deposition device is controlled so that the first and second low refractive index layers form compressive stress and the first and second high refractive index layers form tensile stress.

9. In paragraph 8, A method for manufacturing a lens in which the ion source output of the ion assist deposition device is lower than the output of the first and second low refractive index layers.

10. In paragraph 8, A method for manufacturing a lens, characterized in that the substrate surface temperature is 80°C to 110°C when depositing the first and second high refractive index layers and the first and second low refractive index layers.

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