Eyeglass lenses
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- TOKAI OPTICAL CO LTD
- Filing Date
- 2022-05-17
- Publication Date
- 2026-07-31
Smart Images
Figure 0007898156000004 
Figure 0007898156000005 
Figure 0007898156000006
Abstract
Description
Technical Field
[0001] The present invention relates to spectacle lenses such as plastic spectacle lenses, glass spectacle lenses, and sunglasses.
Background Art
[0002] As a spectacle lens, one described in Japanese Patent No. 6270306 (Patent Document 1) is known. This spectacle lens has a first region colored blue to green and a second region colored yellow for the purpose of making it easy to recognize a moving object and easy to recognize traffic signs in a dark situation. These colorings are made by applying ink to the corresponding regions on the base material.
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0004] In the above spectacle lens, although the visibility of a moving object and traffic signs is improved by having a plurality of regions colored with different colors, other functions are not exhibited. Moreover, in the above spectacle lens, since it is colored by applying ink, the color tends to stand out, and there is a possibility of reducing the visibility other than a moving object and traffic signs. Therefore, the first main object of the present invention is to provide a spectacle lens capable of exhibiting a new function by a plurality of regions having different colors. Another main object of the present invention is to provide a spectacle lens in which a decrease in visibility due to coloring is suppressed.
Means for Solving the Problems
[0005] This specification discloses an eyeglass lens. The eyeglass lens comprises a substrate and a first anti-reflective coating and a second anti-reflective coating formed on the substrate. Furthermore, The first anti-reflective film is an alternating film of eight layers, in which a high refractive index layer made of a high refractive index material and a low refractive index layer made of a low refractive index material are alternately arranged, with the first layer, which is the layer closest to the substrate, being the high refractive index layer. The second anti-reflective film is an alternating film of seven layers, in which the first layer of the first anti-reflective film is the low refractive index layer, with the first layer being the low refractive index layer. The difference in average reflectance in the blue region, which is the difference between the average reflectance in the wavelength range of 380 nm to 500 nm in the first anti-reflective film and the average reflectance in the same wavelength range in the second anti-reflective film, is 4 or more. The average reflectance in the first anti-reflective film and the average reflectance in the second anti-reflective film are average reflectances based on the single-sided reflectance under normal incidence. [Effects of the Invention]
[0006] The first main effect of the present invention is to provide eyeglass lenses that exhibit novel functions through multiple regions having different colors from each other. Furthermore, a second main effect of the present invention is to provide eyeglass lenses in which the reduction in visibility due to coloration is suppressed. [Brief explanation of the drawing]
[0007] [Figure 1] This is a schematic front view of an eyeglass lens belonging to the eyeglass lens according to the present invention. [Figure 2] Figure 1 is a schematic side view of the eyeglass lens and the user's eyeball. [Figure 3] Figure 1 is a schematic cross-sectional view of an eyeglass lens. [Figure 4] This graph shows the spectral transmittance distributions in the visible range for the near-field and intermediate-field applications of Example 1. [Figure 5] This graph shows the spectral transmittance distributions in the visible range for the near-field and intermediate-field applications of Example 2. [Figure 6] This graph shows the spectral transmittance distributions in the visible range for the near-field and intermediate-field applications of Example 3. [Figure 7] This graph shows the spectral transmittance distributions in the visible range for the near-field and intermediate-field applications of Example 4. [Figure 8] This graph shows the spectral transmittance distributions in the visible range for the near-field and intermediate-field sections of Example 5. [Figure 9] This graph shows the spectral reflectance distribution in the visible range for the concave-side optical multilayer film alone, which is common to Examples 1 to 5. [Modes for carrying out the invention]
[0008] Examples of embodiments of the present invention will be described below with reference to the drawings as appropriate. However, the embodiments of the present invention are not limited to these examples.
[0009] As shown in Figure 1, the spectacle lens 1 according to the present invention is circular (round lens) when viewed from the front of the wearer (user), based on the lens's position when worn. The spectacle lens 1 is curved in a way that it is convex forward when viewed from the side of the user in order to impart prescription. The spectacle lens 1 differs for the right eye and the left eye, with the right eye lens shown in Figure 1. In Figure 1, the top is the top when worn, and the right is the nose side of the wearer. After the prescription and other parameters of the round lens 1 are adjusted, it is shaped to match the shape of the eyeglass frame and then fitted into the eyeglass frame. The wearer actually wears the eyeglass frame with the shaped eyeglass lens 1 fitted into it. Furthermore, the eyeglass lens 1 before shaping may not be circular. Also, the eyeglass lens 1 may be non-prescription and may be flat with no curvature when viewed from the side. Moreover, the eyeglass lens 1 for the right eye and the left eye may be identical.
[0010] The eyeglass lens 1 comprises a base material 2, a convex-side optical multilayer film 4 (the optical multilayer film on the front side when worn), and a concave-side optical multilayer film 6 (the optical multilayer film on the back side when worn). Furthermore, the spectacle lens 1 is a progressive refractive power lens and has a near-vision section 12 and a far-vision intermediate section 14. The near-vision section 12 is located at the bottom of the spectacle lens 1. The near-vision section 12 has refractive power that corresponds to close objects. The near-vision section 12 is the part for viewing objects at a close distance. The distance-vision intermediate section 14 occupies the portion of the spectacle lens 1 other than the near-vision section 12. The distance-vision intermediate section 14 has a distance-vision section 16 and an intermediate section 18. The distance-vision section 16 is located at the top of the spectacle lens 1. The distance-vision section 16 has refractive power corresponding to distant objects. The distance-vision section 16 is the part for viewing objects that are farther away than the near-vision section 12. Distant and near views, as well as distance and near vision, are all relative concepts. The intermediate portion 18 is disposed between the near vision portion 12 and the distance vision portion 16. The diopter of the intermediate portion 18 continuously changes between the near vision portion 12 and the intermediate distance portion 14. The diopter of the intermediate portion 18 progresses from the intermediate distance portion 14 to the near vision portion 12. Incidentally, the intermediate distance portion 14 may have only one of the distance vision portion 16 and the intermediate portion 18.
[0011] The spectacle lens 1 has various reference points. The circular center of the spectacle lens 1 is the geometric center GC. Further, the spectacle lens 1 has an optical center OC. The optical center OC is a point assuming the correspondence with the position of the wearer's pupil as viewed from the front side during wearing. Furthermore, the spectacle lens 1 has a distance vision reference point FV. The distance vision reference point FV is disposed within the distance vision portion 16, and here it is the lower side portion of the intermediate distance portion 14 and is a point above the geometric center GC. The distance vision reference point FV is a reference point for measuring the distance vision diopter of the spectacle lens 1. The refractive power at the distance vision reference point FV is set based on, for example, the prescribed distance vision diopter (prescribed distance prescription). Still further, the spectacle lens 1 has a near vision reference point NV. The near vision reference point NV is disposed within the near vision portion 12, and here it is the upper side portion of the near vision portion 12 and is a point below the geometric center GC. The near vision reference point NV is a reference point for measuring the near vision diopter of the spectacle lens 1. The refractive power at the near vision reference point NV is set based on, for example, the prescribed distance vision diopter and the prescribed addition diopter (prescribed addition) specified by the prescription. The near vision reference point NV and its adjacent portion form a near vision eye point NE which is a position where the near side is most visible. The optical center OC is between the distance vision reference point FV and the near vision reference point NV and has a predetermined addition with respect to the prescribed distance vision diopter. The absolute value of the addition at the optical center OC is smaller than the absolute value of the prescribed addition at the near vision reference point NV. And coordinates with the optical center OC as the origin can be set. A horizontal (naso - auricular direction) straight line passing through the origin can be set as the X - axis. The auricular side can be set as the positive direction on the X - axis. A vertical (up - down direction) straight line passing through the origin can be set as the Y - axis. The upper side can be set as the positive direction on the Y - axis. Furthermore, the arrangement (layout) of various reference points, the presence or absence of settings, the origin of coordinates, the types of coordinate axes, the directions of coordinate axes, etc. are not limited to those described above.
[0012] FIG. 2 is a schematic side view of the spectacle lens 1 and the user's eyeball EB. The eyeball EB can rotate about the center of rotation point TP. When the user looks straight ahead with the eyeball EB, the line of sight EL passes through the optical center OC. The distance Δz between the optical center OC and the center of rotation point TP is generally set to 25 mm (millimeters). Also, when the user looks downward where the near is assumed with the eyeball EB, in view of the optimal range of eye movement, the direction DD at an angle θ of 20° from the horizontal plane including the line of sight EL extending straight ahead is easy to see and serves as a reference for near vision. Then, the vertical distance Δy between the point DP where the direction DD (the direction of the near vision line of sight) of the reference for near vision intersects the spectacle lens 1 and the optical center OC is as follows according to the following formula (1). Δy = 25 × tan20° ≈ 9 [mm] ···(1) Therefore, the boundary between the near-use portion 12 and the intermediate distance portion 14 is set downward by approximately Δy ≈ 9 mm from the optical center OC. That is, the near-use portion 12 is arranged below the boundary 9 mm below the optical center OC in the base material 2.
[0013] The base material 2 occupies most of the spectacle lens 1. The base material 2 is the part that serves as the base of the spectacle lens 1. As the material for base material 2, for example, glass or synthetic resin can be used, preferably thermosetting resin, such as polyurethane resin, thiourethane resin, episulfide resin, polycarbonate resin, polyester resin, acrylic resin, polyethersulfone resin, poly-4-methylpentene-1 resin, diethylene glycol bisallyl carbonate resin, or a combination thereof can be used. Furthermore, as a material with a high refractive index that is suitable, for example, polyurethane resin obtained by addition polymerization of a polyisocyanate compound and at least one of polythiol and sulfur-containing polyol can be cited, and as a material with an even higher refractive index that is suitable, episulfide resin obtained by addition polymerization of an episulfide group and at least one of polythiol and sulfur-containing polyol can be cited. A UV absorber is preferably added to the base material 2. The thickness of the base material 2 is not particularly limited.
[0014] The convex-side optical multilayer film 4 is formed on the convex surface F (front surface) of the substrate 2. The convex-side optical multilayer film 4 may be formed directly on the convex surface F, or it may be formed indirectly on the convex surface F via an interlayer. An interlayer, such as a hard coat film, may be formed. The hard coat film is preferably formed by uniformly applying a hard coat liquid to the surface of the substrate 2. Furthermore, as the hard coat film, an organosiloxane resin containing inorganic oxide fine particles is preferably used. The organosiloxane resin is preferably obtained by hydrolyzing and condensing an alkoxysilane. Specific examples of organosiloxane resins include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, methyltrimethoxysilane, ethyl silicate, or combinations thereof. These hydrolysis condensates of alkoxysilanes are produced by hydrolyzing the alkoxysilane compound or combination thereof with an acidic aqueous solution such as hydrochloric acid. On the other hand, specific examples of the material of inorganic oxide fine particles include zinc oxide, silicon dioxide (silica fine particles), aluminum oxide, titanium oxide (titania fine particles), zirconium oxide (zirconia fine particles), tin oxide, beryllium oxide, antimony oxide, tungsten oxide, and cerium oxide, either individually or mixed crystals of two or more of these materials. From the viewpoint of ensuring the transparency of the hard coat film, the diameter of the inorganic oxide fine particles is preferably 1 nm (nanometer) or more and 100 nm or less, and more preferably 1 nm or more and 50 nm or less. Furthermore, from the viewpoint of ensuring an appropriate degree of hardness and toughness in the hard coat film, the amount (concentration) of inorganic oxide fine particles is preferably 40 wt% (weight percent) or more and 60 wt% or less of the total components of the hard coat film. In addition, at least one of acetylacetone metal salt and ethylenediaminetetraacetate metal salt can be added to the hard coat liquid as a curing catalyst, and surfactants, colorants, solvents, etc. can be added as needed to ensure adhesion to the substrate 2 and to facilitate formation. The physical thickness of the hard coat film is preferably 0.5 μm (micrometers) or more and 4.0 μm or less, and more preferably 1.0 μm or more and 3.0 μm or less. The lower limit of this film thickness range is determined because it is difficult to obtain sufficient hardness if the film is thinner than this. On the other hand, the upper limit is determined because if the film is thicker than this, the possibility of problems related to physical properties, such as the occurrence of at least one of cracks and brittleness, increases dramatically. Furthermore, as an intermediate film, a primer film may be added between the hard coat film and the surface of the substrate 2 to improve the adhesion of the hard coat film. Examples of materials for the primer film include polyurethane resins, acrylic resins, methacrylic resins, organosilicon resins, or combinations thereof. The primer film is preferably formed by uniformly applying a primer solution to the surface of the substrate 2. The primer solution is a liquid obtained by mixing the above-mentioned resin material and inorganic oxide fine particles in water or an alcohol-based solvent.
[0015] As shown in Figure 3, the convex-side optical multilayer film 4 has a first portion 20 as a first anti-reflective film and a second portion 22 as a second anti-reflective film. The first portion 20 is formed in a manner corresponding to the near-vision portion 12. The second portion 22 is formed in a manner corresponding to the far-vision intermediate portion 14. The first portion 20 and the second portion 22 do not overlap. Part 1, section 20, is an anti-reflective coating that suppresses the reflection of visible light. Visible light is light whose wavelength range is the visible range. In this context, the visible range is 380 nm to 780 nm. The lower limit of the visible range may be 390 nm, 400 nm, 410 nm, or 420 nm. The upper limit of the visible range may be 700 nm, 720 nm, 750 nm, or 760 nm. The first portion 20 is preferably formed by alternately laminating a low refractive index layer L made of a low refractive index material and a high refractive index layer H made of a high refractive index material. The first portion 20 may further include a medium refractive index layer. The design of the first part 20 is modified, and the layer structure of the first part 20 is changed, by changing design elements such as the number and material of the high refractive index layer H and the low refractive index layer L (and the medium refractive index layer), and by increasing or decreasing the thickness of each layer (physical film thickness or optical film thickness related to the layer).
[0016] The high refractive index layer H is preferably an inorganic layer using a dielectric material. The high refractive index material is, for example, zirconium oxide (ZrO2), titanium oxide (TiO2), tantalum oxide (Ta2O5), niobium oxide (Nb2O5), hafnium oxide (HfO2), selenium oxide (CeO2), lanthanum oxide (La2O3), or praseodymium oxide (Pr2O3), or a mixture of two or more of these, and is preferably ZrO2. The low refractive index layer L is preferably an inorganic layer using a dielectric material. The low refractive index material is, for example, silicon dioxide (SiO2), aluminum oxide (Al2O3), calcium fluoride (CaF2), magnesium fluoride (MgF2), a combination of aluminum oxide and praseodymium oxide (Al2O3-Pr2O3), a combination of aluminum oxide and lanthanum oxide (Al2O3-La2O3), or a combination of aluminum oxide and tantalum oxide (Al2O3-Ta2O5), or a mixture of two or more of these, and is preferably SiO2. The intermediate refractive index layer is formed from intermediate refractive index materials such as Al2O3, Pr2O3, La2O3, Al2O3-Pr2O3, and Al2O3-La2O3. At least one of these intermediate refractive index materials may be treated as either a low refractive index material or a high refractive index material. In the first part 20, from the viewpoint of ease of film design and film deposition cost, it is preferable that two or fewer high refractive index materials and two or fewer low refractive index materials are used, and it is more preferable that one high refractive index material and one low refractive index material are used.
[0017] The low refractive index layer L and the high refractive index layer H (and the medium refractive index layer) of the first part 20 are formed, for example, by physical vapor deposition, and more specifically by at least one of the following: vacuum vapor deposition, ion-assisted vapor deposition, ion plating, or sputtering.
[0018] On the other hand, the second part 22 is the same as the first part 20, except that the layer structure is different. The layer structure of the second part 22 is preferably obtained by removing at least one layer from the first part 20. The layer structure of the second part 22 may also be obtained by varying the film thickness of at least one layer in the first part 20, or by adding one or more layers to the underside (substrate 2 side) or upperside (air side) of any of the layers in the layer structure of the first part 20, or by a combination of these.
[0019] The formation of the second portion 22 is preferably carried out simultaneously with the formation of the first portion 20, and it is preferable that a mask covering either the first portion 20 or the second portion 22 is used. Furthermore, the first part 20 and the second part 22 may be formed separately from each other.
[0020] As a result of forming the first part 20 and the second part 22 with different layer structures, the reflection of visible light is suppressed, and the reflectance distribution in the visible range of the reflected light, which occurs to a maximum of about 15% or less, differs between the near-vision part 12 and the far-vision intermediate part 14. Therefore, the color of the reflected light (reflected color) that the user can recognize if they pay attention will be different in the near-vision section 12 and the far-vision intermediate section 14. For example, the user can recognize a nearly transparent bluish-purple in the near-vision section 12 and a nearly transparent blue in the far-vision intermediate section 14. Therefore, in eyeglass lens 1, the user can distinguish between the near-vision portion 12 and the intermediate distance-vision portion 14. In other words, in eyeglass lens 1, the range of the near-vision portion 12 and the range of the intermediate distance-vision portion 14 are more clearly indicated to the user. Furthermore, the difference in color between the near-vision section 12 and the far-vision intermediate section 14 is indicated by the reflective color. Therefore, compared to cases where the lenses are colored by dyeing, the reduction in visibility due to coloration is suppressed.
[0021] The state of the convex-side optical multilayer film 4 at the boundary between the first part 20 and the second part 22 can be anything. For example, the convex-side optical multilayer film 4 may exhibit an intermediate structure between the first portion 20 and the second portion 22 at the band-shaped boundary portion. From the viewpoint of more clearly indicating to the user the near-use section 12 and the far-use intermediate section 14, it is preferable that the layered structures of the first section 20 and the second section 22 switch abruptly at the linear boundary. Furthermore, the application of different reflective colors is not limited to the near-vision section 12 and the far-vision intermediate section 14. Also, the application of different reflective colors is not limited to a total of two colors. For example, such reflective colors may be applied to the near-vision section 12, the far-vision section 16, and the intermediate section 18, respectively. Also, such reflective colors may be applied to the part on the user's nose side and the part on their ear side, respectively. The application of color by reflected light may also be by the complementary color of the reflected light. Parts or all of the first section 20 and the second section 22 may be separated from each other.
[0022] Furthermore, the concave optical multilayer film 6 is formed on the concave surface B (rear surface) of the substrate 2. The concave optical multilayer film 6 may be formed directly on the concave surface B, or it may be formed indirectly on the concave surface B via an interlayer. The interlayer is similar to, for example, the interlayer on the convex surface F. The concave-side optical multilayer film 6 is an anti-reflective coating that suppresses the reflection of visible light. The concave-side optical multilayer film 6 primarily suppresses the reflection of visible light toward the user. Furthermore, at least one of the first part 20, the second part 22, and the concave optical multilayer film 6 may have other functions, including a function to cut out light of a specific color (e.g., blue), in place of or in conjunction with the anti-reflective function. Cutting out light of a specific color includes making the average transmittance of light of the specific color even lower than the average transmittance of light of other colors.
[0023] The concave optical multilayer film 6 is similar to the first portion 20 of the convex optical multilayer film 4, except that the area in which it is formed and its layer structure are different. The concave optical multilayer film 6 is formed over the entire concave surface B. Furthermore, the concave optical multilayer film 6 here consists of five alternating layers: a high refractive index layer H and a low refractive index layer L. Here, at least one of the high refractive index material and the low refractive index material is preferably the same as the material in the convex optical multilayer film 4, from the viewpoint of reducing costs by reducing the types of materials used. Furthermore, at least one of the high-refractive-index material and the low-refractive-index material in the concave-side optical multilayer film 6 may be different from the material in the convex-side optical multilayer film 4. Also, the concave-side optical multilayer film 6 may be omitted or may be something other than an anti-reflective coating. Moreover, the concave-side optical multilayer film 6 may have a first portion corresponding to the near-vision portion 12 and a second portion corresponding to the far-vision intermediate portion 14, similar to the convex-side optical multilayer film 4. In this case, at least one of the first portion and the second portion may have the same film structure as the first portion 20 and second portion 22 of the convex-side optical multilayer film 4. The convex-side optical multilayer film 4 may have the same structure over the entire convex surface F, and the concave-side optical multilayer film 6 may have a first portion and a second portion. [Examples]
[0024] Next, an embodiment relating to the above-described embodiment of the present invention is shown. However, the examples provided are not intended to limit the scope of the present invention. Furthermore, depending on how the present invention is interpreted, an example may become a comparative example that falls outside the scope of the present invention, or a comparative example may become an example.
[0025] [Examples 1-5] ≪Base material 2 etc.≫ Examples 1 to 5 are all plastic spectacle lenses 1, and their base materials 2 are all made of thermosetting resin for eyeglasses and are circular in size, which is standard for spectacle lenses 1. Substrate 2 is common to all Examples 1-5 and is a spherical lens with a center thickness of 1.9 mm and a power of S-0.00, made of thiourethane resin with a refractive index of 1.60. Each substrate 2 is colorless and transparent.
[0026] <<Hard coating film, etc.>> Furthermore, in these Examples 1 to 5, a hard coat film was applied to both sides of each substrate 2 as an interlayer. Furthermore, the hard coat film in contact with the substrate 2 can be formed by applying the hard coat liquid to the substrate 2 and heating it, as follows. Specifically, first, 206 g of methanol, 300 g of methanol-dispersed titania sol (manufactured by JGC Catalysts & Chemicals Co., Ltd., 30% solids), 60 g of γ-glycidoxypropyltrimethoxysilane, 30 g of γ-glycidoxypropylmethyldiethoxysilane, and 60 g of tetraethoxysilane were added dropwise to a reaction vessel. Then, a 0.01 N (normal concentration) aqueous hydrochloric acid solution was added dropwise to the mixture and stirred to carry out hydrolysis. Next, 0.5 g of flow regulator and 1.0 g of catalyst were added, and the mixture was stirred at room temperature for 3 hours to form a hard coat solution. Then, this hard coat liquid was applied to both sides of substrate 2 and heated and cured at 120°C for 1.5 hours to form a hard coat film with a thickness of 2.5 μm.
[0027] <<Convex-side optical multilayer film 4 and concave-side optical multilayer film 6, etc.>> Furthermore, in Examples 1 to 5, convex-side optical multilayer films 4 with different layer structures were formed on the hard coat layer on the convex surface F of each substrate 2. Furthermore, in Examples 1 to 5, a concave-side optical multilayer film 6 with the same layer structure was formed on the hard coat layer on the concave surface B of each substrate 2. The layer structure of each convex-side optical multilayer film 4 in Examples 1 to 5 is shown in Table 1, with the substrate 2 side being the first layer (and so on). Furthermore, the layer structure of each concave-side optical multilayer film 6 in Examples 1 to 5 is shown in Table 2.
[0028] [Table 1] [Table 2]
[0029] The convex-side optical multilayer film 4 of Example 1 can be formed by vacuum deposition, for example, as shown below. Specifically, the holder that holds the substrate 2 is initially attached to the dome inside the vacuum chamber with a mask. The mask is fixed to the holder so as to cover the far-field intermediate portion 14 (convex surface F side) of the substrate 2, but not the near-field portion 12. Then, the first layer of the near-field portion 12 (a ZrO2 layer made by Canon Optron Inc. as a high refractive index layer H) is deposited to have a physical film thickness of 20.00 nm. Note that, due to the mask, the ZrO2 layer is not formed on the far-field intermediate portion 14 at this point. Next, the mask is removed, and the second layer of the near-vision section 12, which is the first layer of the far-vision intermediate section 14 (an SiO2 layer manufactured by Canon Optron Inc. as a low refractive index layer L), is deposited to have a physical film thickness of 10.00 nm. Next, the third layer of the near-vision section 12, which is the second layer of the far-vision intermediate section 14 (ZrO2 layer), the fourth layer of the near-vision section 12, which is the third layer of the far-vision intermediate section 14 (SiO2 layer), the fifth layer of the near-vision section 12, which is the fourth layer of the far-vision intermediate section 14 (ZrO2 layer), the sixth layer of the near-vision section 12, which is the fifth layer of the far-vision intermediate section 14 (SiO2 layer), the seventh layer of the near-vision section 12, which is the sixth layer of the far-vision intermediate section 14 (ZrO2 layer), and the eighth layer of the near-vision section 12, which is the seventh layer of the far-vision intermediate section 14 (SiO2 layer) are deposited so that they have the respective physical film thicknesses described in Table 1 above. Furthermore, the convex-side optical multilayer film 4 of Example 1 is
[0030] The concave optical multilayer film 6 of Example 1 can be formed by a conventional vacuum deposition method without a mask.
[0031] The convex-side optical multilayer films 4 of Examples 2 to 5 can be formed in the same manner as the convex-side optical multilayer film 4 of Example 1, except that the physical film thickness is differed by changing at least one of the deposition time and deposition rate for each layer. Furthermore, the convex-side optical multilayer films 4 of Examples 2 to 5 have the same modifications as those in Example 1. Furthermore, the concave-side optical multilayer film 6 can be formed in the same manner as the concave-side optical multilayer film 6 of Example 1.
[0032] ≪Reflectance distribution, etc.≫ For Examples 1 to 5, the spectral reflectance distributions (normal incidence, single-sided reflectance) in the visible range were measured for the near-vision section 12 and the far-vision intermediate section 14 (Figures 4 to 8). Furthermore, for Examples 1 to 5, the average reflectances in the blue range (here, 380 nm to 500 nm) and the luminous efficiency reflectance (D65 light source, 2° field of view) for the near-vision section 12 and the far-vision intermediate section 14 were calculated (top and middle sections of Table 3). Additionally, the difference in average blue range reflectance was calculated by subtracting the average blue range reflectance of the far-vision intermediate section 14 from the average blue range reflectance of the near-vision section 12 (bottom of Table 3). On the other hand, the reflectance distribution in the visible range for the concave-side optical multilayer film 6 alone, which is common to Examples 1 to 5, was measured (Figure 9).
[0033] [Table 3]
[0034] In Examples 1 to 5, the reflectance distribution in the visible range differs between the near-vision section 12 and the far-vision intermediate section 14. Furthermore, in Examples 1 to 5, the luminous reflectance of the near-vision section 12 is 2% or less. Moreover, in Examples 1 to 5, the luminous reflectance of the far-vision intermediate section 14 is 2.5% or less, and in particular, the luminous reflectance of the far-vision intermediate section 14 in Examples 1 to 4 is 2% or less in all cases. Therefore, in Examples 1 to 5, the reflection of visible light is suppressed in the near-vision section 12 and the far-vision intermediate section 14, and the reflected colors that occur at a small rate compared to transmitted light are different from each other. Furthermore, in all of Examples 1 to 5, while having a visible light anti-reflection function, the average reflectance in the blue region of the near-vision section 12 falls within the range of 8% to 9%, and the average reflectance in the blue region of the far-vision intermediate section 14 falls within the range of 2% to 8%. Therefore, Examples 1 to 5 are provided with a function to cut blue light. Furthermore, in Examples 1-3 and 5, the difference in average blue reflectance falls within the range of 3 or more (7 or less), and in Examples 1-2 and 5 in particular, the difference in average blue reflectance falls within the range of 5 or more (7 or less). Therefore, the difference in reflected color becomes more pronounced. In particular, the difference obtained by subtracting the average blue reflectance of a typical anti-reflective film (typically with a green reflected color) from the average blue reflectance of a typical blue light-cutting film is about 4, so if the difference in average blue reflectance is 4 or more, users will be able to recognize the difference in reflected color more easily. In Examples 1 and 2, the luminous reflectance of the near-vision section 12 and the far-vision intermediate section 14 are 2% or less, and the average reflectance difference in the blue region is 4 or more. Therefore, in Examples 1 and 2, the reflection of visible light is sufficiently suppressed while cutting out blue light, and the color difference between the near-vision section 12 (blue-violet) and the far-vision intermediate section 14 (blue) is more pronounced.
[0035] ≪Durability etc.≫ Furthermore, three types of durability tests were conducted on Examples 1 to 5 to investigate their durability.
[0036] The first durability test is conducted as follows: Each sample, which is a round lens (Examples 1-5), is placed in a constant temperature and humidity chamber maintained at 60°C and 95% relative humidity for 3 days, after which it is removed and its condition is observed (constant temperature and humidity test). The results of the first durability test are shown in the rows (two locations) labeled "Constant Temperature and Humidity Test" in Table 3 above. In this first durability test, no abnormalities in appearance or other problems were observed in either the near-vision section 12 or the far-vision intermediate section 14 of any of the samples.
[0037] The second durability test is conducted in the same manner as the first durability test, after the sample has been shaped into a ball (constant temperature and humidity test after ball shaping). The results of the second durability test are shown in the row for "Constant Temperature and Humidity (Ball Shape Processing)" (in two places) in Table 3 above. In this second durability test, no abnormalities in appearance or other issues were observed in either the near-vision section 12 or the far-vision intermediate section 14 in any of the samples.
[0038] The third durability test is conducted by performing the same process as the second durability test, followed by placing each sample in a drying oven (constant temperature and humidity test after lens shaping + heat resistance test). Each sample is placed in a drying oven maintained at 70°C for 30 minutes. The third durability test is achieved by accelerating long-term degradation in a short period of time through the constant temperature and humidity test, and by subjecting the sample, which has undergone simulated long-term degradation, to a heat resistance test, thus accurately simulating the use of a typical eyeglass lens 1. The results of the third durability test are shown in the row (in two places) for "Constant Temperature and Humidity (Ball Shape Processing) + Oven" in Table 3 above. In this third durability test, no abnormalities in appearance or other issues were observed in either the near-vision section 12 or the far-vision intermediate section 14 in any of the samples.
[0039] Durability will be further investigated. In Examples 1 to 5, the first layer of the first portion 20 of the convex optical multilayer film 4 is a ZrO2 layer, the second layer of the first portion 20 and the first layer of the second portion 22 are both SiO2 layers, and the third layer of the first portion 20 and the second layer of the second portion 22 are both ZrO2 layers. The ZrO2 layer has tensile stress. The magnitude of the tensile stress in the ZrO2 layer is proportional to the physical thickness of the layer. The tensile stress in the ZrO2 layers from the third layer onward in the first section 20 and from the second layer onward in the second section 22 is relieved by two adjacent SiO2 layers that have compressive stress on both the substrate 2 side and the atmosphere side. On the other hand, the first ZrO2 layer of the first section 20 is in contact with a hard coat film rather than an SiO2 layer on the substrate 2 side, and is subjected to a relatively weak tensile stress relief effect, resulting in a relatively strong residual tensile stress. In addition to Examples 1-5, multiple alternating films (anti-reflective films) of six SiO2 layers with the first layer being a ZrO2 layer were prepared with various physical thicknesses of the first layer. When durability tests were conducted on these films, it was found that when the physical thickness of the first layer was 40 nm or more, cracks occurred in the convex optical multilayer film 4 after the heat resistance test in the third durability test. Therefore, the physical thickness of the first ZrO2 layer of the first portion 20 is preferably less than 40 nm, and more preferably 30 nm or less, as in Examples 1-5.
[0040] On the other hand, the presence of the first ZrO2 layer in the first part 20 is a structural difference from the second part 22, and is the basis for the difference in the reflected colors of the first part 20 and the second part 22. Therefore, the physical film thickness of the first ZrO2 layer in the first part 20 is preferably 10 nm or more, as in Examples 1 to 5, and more preferably 20 nm or more, as in Examples 1 to 2. The first to third layers of the first part 20 can also be understood as follows: In realizing optical functions based on anti-reflection, it is sufficient to have a ZrO2 layer with a combined physical thickness of the first and third layers of the first part 20, and the second SiO2 layer is not essential. However, if the physical thickness of the ZrO2 layer closest to the substrate 2 exceeds 40 nm, the durability will be relatively poor. Therefore, the ZrO2 layer closest to the substrate 2 is divided by the second SiO2 layer, thereby easing the tensile stress in the ZrO2 layer closest to the substrate 2 and improving durability. From this viewpoint, it is preferable that the physical thickness of the second SiO2 layer be as small as possible, preferably 10 nm or less.
[0041] Summary etc. As shown in Examples 1 to 5, the invention comprises a substrate 2 and a convex-side optical multilayer film 4 formed on the substrate 2, comprising a first portion 20 (first anti-reflective film) and a second portion 22 (second anti-reflective film), wherein the reflective color of the first portion 20 and the reflective color of the second portion 22 are different from each other. Therefore, eyeglass lenses are provided that allow the user to see multiple areas (near-vision area 12 and far-vision intermediate area 14) with different colors, while suppressing a decrease in visibility.
[0042] Furthermore, in Examples 1 to 5, the base material 2 has a near-vision section 12 for viewing objects at a closer distance, and the first section 20 is positioned in the near-vision section 12. Therefore, in the progressive power lens, the range of the near-vision section 12 is presented to the user, and the user can more clearly identify the near-vision section 12 to be used when viewing objects up close. Furthermore, in Examples 1 to 5, the near-vision section 12 is positioned below the boundary 9 mm below the optical center OC on the substrate 2. Therefore, the range of the near-vision section 12 is set to a position that naturally corresponds to the view through the near-vision section 12.
[0043] In addition, in Examples 1-5, the first part 20 is, A high refractive index layer H made of a high refractive index material and a low refractive index layer L made of a low refractive index material. The first layer, which is the layer closest to the base material 2, High refractive index layer H It is an alternating membrane consisting of eight layers arranged alternately, and the second part 22 is the first layer of the first part 20 High refractive index layer H The first layer, which was omitted Low refractive index layer L This is a total of 7 layers of alternating membranes. Also, in Examples 1 to 5, high The refractive index material is ZrO2. low The refractive index material is SiO2. Therefore, the first part 20 and the second part 22 can be formed more easily. Furthermore, in Examples 1 to 5, the physical film thickness of the first high refractive index layer H in the first portion 20 is less than 40 nm. Therefore, the durability of the spectacle lens 1 is further improved. Furthermore, the physical thickness of the second low-refractive-index layer L in the first portion 20 is 10 nm or less. Therefore, the stress on the first high-refractive-index layer H is relieved while suppressing the optical influence of the second layer on the first portion 20. Consequently, the durability of the spectacle lens 1 is further improved.
[0044] Furthermore, in Examples 1 to 4, the luminous reflectance of the first part 20 and the second part 22 is 2% or less. Therefore, the anti-reflective properties of the spectacle lens 1 are further improved. Furthermore, in Examples 1-2 and 5, the difference in average reflectance in the blue region (wavelength range of 380 nm to 500 nm) between the first section 20 and the second section 22 is 4 or more. Therefore, it is easier to distinguish between the near-vision section 12 and the far-vision intermediate section 14. In addition, a blue light cut function is further provided in the near-vision section 12, etc. [Explanation of Symbols]
[0045] 1. Eyeglass lens, 2. Substrate, 4. Convex-side optical multilayer coating, 6. Concave-side optical multilayer coating, 12. Near-vision section, 20. First part (first anti-reflective coating), 22. Second part (second anti-reflective coating), H. High refractive index layer, L. Low refractive index layer.
Claims
1. Substrate and A first anti-reflective film and a second anti-reflective film formed on the substrate, It has, The first anti-reflective film is an alternating film of eight layers, in which a high refractive index layer made of a high refractive index material and a low refractive index layer made of a low refractive index material are alternately arranged, with the first layer, which is the layer closest to the substrate, being the high refractive index layer. The second anti-reflective coating is a seven-layer alternating coating, with the first layer being the low refractive index layer, and the first layer being the low refractive index layer, omitting the first layer of the first anti-reflective coating. The difference in average reflectance in the blue region, which is the difference between the average reflectance in the wavelength range of 380 nm to 500 nm in the first anti-reflective coating and the average reflectance in the same wavelength range in the second anti-reflective coating, is 4 or more. The average reflectance in the first anti-reflective coating and the average reflectance in the second anti-reflective coating are average reflectances based on the single-sided reflectance under normal incidence. Eyeglass lenses characterized by the following features.
2. The aforementioned substrate has a near-view section for viewing objects at a closer distance. The first anti-reflective coating is located in the near-field portion. Eyeglass lens as described in Feature 1.
3. The aforementioned near-vision portion is positioned below the boundary 9 mm below the optical center of the substrate. Eyeglass lens according to feature 2.
4. The aforementioned high refractive index material is ZrO ２ And, The low refractive index material is SiO ２ That is An eyeglass lens according to any one of claims 1 to 3.
5. The physical thickness of the first high refractive index layer in the first anti-reflective coating is less than 40 nm. An eyeglass lens according to any one of claims 1 to 3.
6. The physical thickness of the second low refractive index layer in the first anti-reflective coating is 10 nm or less. An eyeglass lens according to any one of claims 1 to 3.
7. The luminous reflectance of the first anti-reflective coating and the second anti-reflective coating are 2% or less. An eyeglass lens according to any one of claims 1 to 3.