Mold manufacturing method, optical member manufacturing method, and spectacle lens

Abstract

A mold manufacturing method is provided, comprising: a step (S11) of preparing a glass mold made of glass material as a forming mold, the forming mold being used to manufacture an optical component having a convex defocus portion on at least one optical surface; and a step (S12) of irradiating the forming surface of the optical surface in the glass mold with a short-pulse laser to form a concave portion corresponding to the defocus portion.

Description

Technical Field

[0001] This invention relates to mold manufacturing methods, optical component manufacturing methods, and eyeglass lenses. Background Technology

[0002] In recent years, spectacle lenses designed to suppress the development of refractive errors such as myopia have emerged, featuring a convex defocusing portion formed on the object-side optical surface (see, for example, Patent Document 1). These lenses are manufactured by molding a resin material, typically using a metal molding die (see, for example, Patent Document 2).

[0003] [Existing Technical Documents]

[0004] [Patent Literature]

[0005] Patent Document 1: U.S. Publication Application No. 2017 / 0131567

[0006] Patent document 2: International Publication No. 2019 / 124354. Summary of the Invention

[0007] [The problem this invention aims to solve]

[0008] Considering the manufacturing cost of spectacle lenses, it is desirable that molds for spectacle lenses can be easily formed even if the optical surfaces have complex shapes. Furthermore, while there are various types of resin materials that constitute spectacle lenses, depending on factors such as refractive index, it is required that any type can be appropriately molded.

[0009] The purpose of this invention is to provide a manufacturing technology for molding dies that can be easily formed even into complex shapes and are compatible with various resin materials.

[0010] [Problem-solving methods]

[0011] The first aspect of the present invention is:

[0012] A method for manufacturing a mold, the method comprising:

[0013] The step of preparing a glass mold made of glass material as a molding mold, the molding mold being used to manufacture an optical component having a convex defocusing portion on at least one optical surface;

[0014] The step of irradiating the forming surface of the optical surface in the glass mold with a short-pulse laser to form a concave portion corresponding to the defocused portion.

[0015] The second aspect of the present invention is:

[0016] According to the mold manufacturing method described in the first aspect, a concave portion is formed by multiple irradiation zones of the short-pulse laser, and the forming depth of the concave portion is controlled by overlapping each irradiation zone.

[0017] The third aspect of the present invention is:

[0018] According to the mold manufacturing method described in the second aspect, the plurality of irradiation areas are irradiated while the overlap amount is changed, such that the overlap amount of each irradiation area increases from the outer edge side to the center side of the concave portion.

[0019] The fourth aspect of the present invention is:

[0020] According to any one of the first to third aspects described above, the mold manufacturing method includes the step of adjusting the surface shape of the concave portion by grinding the concave portion after it has been irradiated by the short pulse laser.

[0021] The fifth aspect of the present invention is:

[0022] An optical component manufacturing method, wherein an optical component having a defocusing portion on at least one optical surface is manufactured by molding a resin material using a molding die obtained by the optical component mold manufacturing method according to any one of claims 1 to 4.

[0023] The sixth aspect of the present invention is:

[0024] According to the manufacturing method of the optical component described in the fifth aspect, the resin material is a material with a refractive index of 1.40 or higher.

[0025] The seventh aspect of the present invention is:

[0026] According to the method for manufacturing an optical component as described in the fifth or sixth aspect, an eyeglass lens is manufactured as said optical component, the eyeglass lens having: a base region formed such that transmitted light is focused at a predetermined position within the eye; and a defocus region formed such that the transmitted light is focused by the defocus region at a position defocused from the predetermined position.

[0027] The eighth aspect of the present invention is:

[0028] A spectacle lens having optical surfaces located on the object side and the eyeball side, respectively.

[0029] The spectacle lens has, on at least one of the optical surfaces, a defocused region having a defocusing portion formed thereon and a base region without the defocusing portion formed thereon.

[0030] The defocusing portion is formed at multiple locations.

[0031] When the defocusing part has an X-fold rotationally symmetric shape and the configuration of the defocusing part is Y-fold rotationally symmetric, both X and Y are multiples of 3, or both X and Y are multiples of 4.

[0032] The ninth aspect of the present invention is:

[0033] According to the eyeglass lens described in the eighth aspect, the position where light passing through the eyeglass lens is focused by the base region and the position where light passing through the eyeglass lens is focused by the defocusing portion are configured to be different from each other.

[0034] [Invention Effects]

[0035] According to the present invention, it is possible to manufacture molding dies that can easily form even complex shapes and are compatible with various resin materials. Attached Figure Description

[0036] Figure 1 This is a side cross-sectional view showing a structural example of the main part of a spectacle lens according to an embodiment of the present invention.

[0037] Figure 2 This is an explanatory diagram (1) schematically showing an example of the configuration of the defocusing portion in an eyeglass lens according to an embodiment of the present invention, and a diagram showing an example of a six-fold symmetrical configuration.

[0038] Figure 3 This is an explanatory diagram (2) schematically showing an example of the configuration of the defocusing portion in an eyeglass lens according to an embodiment of the present invention, and is also a diagram showing an example of a fourfold symmetrical configuration.

[0039] Figure 4 This is a flowchart illustrating an example of the sequence of a mold manufacturing method according to an embodiment of the present invention.

[0040] Figure 5 This is an explanatory diagram showing an example of the configuration of multiple irradiation zones of a short-pulse laser in a mold manufacturing method according to an embodiment of the present invention. Detailed Implementation

[0041] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0042] In this embodiment, the following description will take the case where the optical component is a spectacle lens as an example.

[0043] (1) Structure of eyeglass lenses

[0044] Figure 1 This is a side sectional view showing a structural example of the main part of the spectacle lens according to this embodiment.

[0045] The spectacle lens 1 has an object-side surface 2 and an eyeball-side surface 3 as optical surfaces. The object-side surface 2 is located on the object side when the wearer wears the glasses with the spectacle lens 1. Conversely, the eyeball-side surface 3 is the opposite, that is, the surface located on the eyeball side when the wearer wears the glasses with the spectacle lens 1.

[0046] A convex defocusing portion 4 is formed on at least one of the object-side surface 2 and the eyeball-side surface 3 (e.g., the object-side surface 2 in this embodiment). That is, the spectacle lens 1 is configured to have a convex defocusing portion 4 on at least one optical surface. Thus, the spectacle lens 1 has: a region where the defocusing portion 4 is not formed (i.e., the base region 5) and a region where the defocusing portion 4 is formed (i.e., the defocused region 6). Furthermore, the defocusing portion 4 is formed at multiple locations, such that the defocused region 6 also exists discretely at multiple locations.

[0047] The base region 5 is a portion having a shape capable of achieving the wearer's prescribed refractive power. That is, the base region 5 is a region consisting of a curved surface having a predetermined curvature (curve) according to the wearer's prescribed refractive power, such that light passing through the spectacle lens 1 is focused at a predetermined position within the wearer's eye, specifically, on the wearer's retina. Therefore, the base region 5 has a shape designed based on the wearer's prescription information. The prescription information, or a medium recording that prescription information, can then be associated with and managed by the spectacle lens 1.

[0048] The defocus region 6 is a region, at least a portion of which does not converge light to the focusing position of the base region 5. That is, the defocus region 6 is a portion of the area where light passing through the spectacle lens 1 is focused from a predetermined position (i.e., a position different from the wearer's retina) by the defocusing unit 4. For example, by performing positive defocusing on the defocusing part 4 and setting a focusing point in front of the wearer's retina, the stimulation received by the retina can be controlled and the development of myopia can be suppressed. In other words, the position where light passing through the spectacle lens 1 is focused by the shape of the base region 5 is different from the position focused by the shape of the defocusing part 4. For example, the position focused by the shape of the defocusing part 4 can be set in front of (object side) the position focused by the shape of the base region 5.

[0049] The defocusing portion 4 forming the defocus region 6 is formed to protrude from the constituent surface of the base region 5 towards the object side, and this protruding surface is formed by a surface with a curvature (curve) different from that of the constituent surface of the base region 5. Thus, light transmitted through the defocusing portion 4 is focused at a position different from that on the wearer's retina. Therefore, the defocusing portion 4 is an optical component with a refractive power different from that of the base region 5. The surface constituting the defocusing portion 4 (i.e., the shape of the protruding surface of the defocusing portion 4) is not particularly limited and can be a spherical shape, an aspherical shape, a complex surface shape, or a mixture thereof. For example, as an aspherical shape, the shape of the defocusing portion 4 can be an aspherical surface with rotational symmetry, specifically X-fold symmetry (X is 3 or 4). More specifically, it can be an aspherical shape with rotational symmetry that is substantially 4-fold or more in its surface shape. Preferred examples are 6-fold or 8-fold symmetry aspherical surfaces. The upper limit is preferably 12-fold or less, more specifically, preferably 10-fold or less. The surface constituting the defocusing portion 4 can be a plane or a polyhedron. For example, shapes obtained by dividing a regular dodecahedron, an icosahedron, etc., into two halves can be used. These can also be included in rotationally symmetric aspherical shapes. In this case, basically any shape as described above is acceptable, and the vertex and ridge portions can be circular. In this embodiment, the case where the defocusing portion 4 has a spherical shape will be illustrated by way of example. The diameter of the defocusing portion 4 viewed from above is, for example, 0.6 to 2.0 mm, and the protrusion height is, for example, 0.1 to 10 μm.

[0050] In this embodiment, it is assumed that a plurality of defocusing portions 4 are regularly arranged on the optical surface (the convex surface on the object side in this embodiment) of the spectacle lens 1. However, the arrangement area on the optical surface is not particularly limited. As long as the plurality of defocusing portions 4 are arranged regularly, the defocusing portions 4 can be arranged on the entire surface of the optical surface, the defocusing portions 4 can be partially arranged in a portion of the optical surface, or a region without defocusing portions 4 can be provided at the center of the lens, and the defocusing portions 4 can be arranged in a circumferentially shaped region to surround that region.

[0051] Multiple defocusing portions 4 are configured as independent islands (i.e., spaced apart from each other without being adjacent to each other). That is, in this embodiment, each defocusing portion 4 is configured discretely (i.e., discontinuous and dispersed). However, while this example illustrates a case where each defocusing portion 4 is an independent island, the invention is not limited to this, and the region where each defocusing portion 4 is configured can be set such that the outer edges of adjacent defocusing portions 4 include either connected outer edges or contacting outer edges.

[0052] A large number (e.g., approximately 200 to 600, more specifically approximately 300 to 500) of defocusing portions 4 can be provided on the aforementioned optical surface. When at least some of these are regularly arranged, the arrangement can possess Y-fold rotational symmetry (Y being a multiple of 3 or 4). For example, a triple-symmetric arrangement means that the aforementioned configuration with a large number of defocusing portions 4 possesses triple rotational symmetry.

[0053] Furthermore, the design can be such that there is a correlation between the shape of each defocusing element 4 and the configuration of the multiple defocusing elements 4. For example, it can be illustrated that when the shape of the defocusing element 4 is X-fold rotationally symmetric and the configuration is Y-fold rotationally symmetric, both X and Y are multiples of 3, or both X and Y are multiples of 4. Specifically, cases where both X and Y are 6 or both are 4 can be appropriately applied. When such a correlational regularity is satisfied, the optical effect of the spectacle lens 1 is advantageous. That is, even if the image on the wearer's retina is blurred, the blur is rotationally symmetric, so the wearer is unlikely to experience discomfort. Blurred images without regularity are easily recognized by the wearer, but blurred images with regularity, especially rotational symmetry, are unlikely to be recognized and are unlikely to cause discomfort or fatigue to the wearer.

[0054] Figure 2 and Figure 3 This is an explanatory diagram schematically showing an example of the configuration of the defocusing section.

[0055] For example, such as Figure 2 As shown, when the defocusing portion 4 (see A in the figure) with a three-dimensional shape of triple symmetry (e.g., a triangle) is arranged in a three-dimensional symmetrical (or six-dimensional symmetrical) configuration, the symmetry is not compromised, and therefore this is the preferred embodiment. This also applies to the defocusing portion 4 (see B in the figure) with a three-dimensional shape of six-dimensional symmetry (e.g., a hexagon). However, for the defocusing portion 4 (see C in the figure) with a three-dimensional shape of four-dimensional symmetry (e.g., a square), if arranged in a three-dimensional symmetrical (or six-dimensional symmetrical) configuration, the symmetry may be compromised.

[0056] Additionally, for example, such as Figure 3 As shown, when the defocusing portion 4 (see C in the figure) with a three-dimensional shape of four-fold symmetry (e.g., a quadrilateral) is arranged in a four-fold symmetrical configuration, the symmetry is not compromised, and therefore this is the preferred embodiment. However, for the defocusing portion 4 (see A in the figure) with a three-dimensional shape of three-fold symmetry (e.g., a triangle) or the defocusing portion 4 (see B in the figure) with a six-fold symmetrical three-dimensional shape, the symmetry may be disrupted if the three-dimensional shape (e.g., a hexagon) is arranged in a four-fold symmetrical configuration.

[0057] As exemplified by the spectacle lens 1 with the structure described above, a refractive error development suppression lens can be used to inhibit the development of refractive errors in the wearer's eye, particularly a myopia development suppression lens. The myopia development suppression lens converges light passing through the base region 5 onto the wearer's retina, while simultaneously converging light passing through the defocus region 6 to a position closer to the object than the retina. That is, in addition to converging light to fulfill the wearer's prescription, the myopia development suppression lens also has the function of converging light to a position closer to the object. By possessing such optical properties, the myopia development suppression lens can exert an effect of inhibiting the development of refractive errors such as myopia in the wearer (hereinafter referred to as the "myopia suppression effect").

[0058] Furthermore, at least one of the object-side surface 2 (convex in this embodiment) and the eyeball-side surface 3 (concave in this embodiment) of the spectacle lens 1 may be coated. Examples of coatings include hard coatings (HC films) and anti-reflective films (AR films), but other films may also be formed. These coatings can be implemented using known techniques, and their detailed description will be omitted here.

[0059] (2) Manufacturing method of spectacle lenses

[0060] The spectacle lens 1 having the above structure is manufactured through the following process. Specifically, the spectacle lens 1 is manufactured through a substrate formation step and a film deposition process as required.

[0061] The substrate forming step is a process of forming the lens substrate of the eyeglass lens 1 by casting resin material using a molding die.

[0062] The lens substrate formed here has a convex defocusing portion 4 on at least one optical surface. To form such a lens substrate, a mold is used as the forming mold, which has a concave portion corresponding to the defocusing portion 4 formed on the forming surface of the optical surface. Details of the forming mold will be described later.

[0063] As the resin material for forming the lens substrate, resins made from various raw materials can be used.

[0064] Specifically, examples of resin materials include polycarbonate resin, urethane urea resin, (thio)polyurethane resin, polysulfide resin, polyamide resin, polyester resin, allyl acrylate resin, (meth)acrylic resin and other styrene resins, diethylene glycol diallyl carbonate resin (CR-39) and other allyl carbonate resins, vinyl resins, polyether resins, etc. Among these resins, polycarbonate resin (thermoplastic resin) has a short curing time in the mold (e.g., less than 10 minutes), thus resulting in high production efficiency, which is advantageous in terms of production cost. (Thio)polyurethane resin refers to at least one selected from thio polyurethane resin obtained by reacting an isocyanate compound with a polythiol compound, and polyurethane resin obtained by reacting an isocyanate compound with a hydroxyl compound such as diethylene glycol. Among these, (thio)polyurethane resin and polysulfide resin are preferred. The advantage of these resins is that they can be used to make spectacle lenses with a high refractive index (e.g., 1.6 or higher). Alternatively, for example, a cured product (commonly referred to as a transparent resin) can be obtained by curing a curable composition containing an epoxy compound having one or more disulfide bonds (thiolated) within its molecule. The curable composition can also be referred to as a polymeric composition. Furthermore, the resin material can be unstained (colorless lens) or stained (tinted lens). Thermosetting resins, including the aforementioned (thiolated) polyurethane resins, require a long molding time (e.g., about 10 to 20 hours) and spend a long time in the mold; therefore, a large number of molds can be used for production, resulting in high efficiency. Thus, relatively inexpensive and easy-to-manufacture glass molds can be advantageously used.

[0065] Furthermore, as the resin material used to form the lens substrate, a resin material with a refractive index (nD) of approximately 1.40 or higher and 1.74 or lower is used, for example. However, the refractive index is not limited to this range and may be within this range or may be higher or lower than this range. In this invention and this specification, refractive index refers to the refractive index for light with a wavelength of 500 nm.

[0066] Furthermore, even within the aforementioned range, the refractive index is particularly preferred as follows: the lens substrate formed of resin material preferably has a refractive index of 1.50 or higher, and more preferably a so-called high refractive index of 1.60 or higher.

[0067] Preferred commercially available lens materials include: allyl carbonate plastic lenses "HILUX1.50" (manufactured by HOYA, refractive index 1.50), thiocarbamate plastic lenses "MERIA" (manufactured by HOYA, refractive index 1.60), thiocarbamate plastic lenses "EYAS" (manufactured by HOYA, refractive index 1.60), thiocarbamate plastic lenses "EYNOA" (manufactured by HOYA, refractive index 1.67), polysulfide plastic lenses "EYRY" (manufactured by HOYA, refractive index 1.70), and polysulfide plastic lenses "EYVIA" (manufactured by HOYA, refractive index 1.74), etc.

[0068] Casting can be performed using well-known techniques, so detailed explanations are omitted here.

[0069] The film-forming process is a process of forming a coating such as an HC film or an AR film on at least one main surface (preferably two main surfaces) of a lens substrate obtained in the substrate formation step.

[0070] HC films are formed, for example, using a curable material containing silicon compounds, and are formed with a thickness of approximately 3 μm to 4 μm. The refractive index (nD) of the HC film is close to that of the lens substrate material, for example, about 1.49 to 1.74, and the film structure is selected according to the lens substrate material. By coating such an HC film, the durability of eyeglass lenses can be improved. For example, an HC film can be formed by impregnation using a solution of a curable material containing silicon compounds.

[0071] AR (Advanced Refractive Index) films have a multilayer structure with laminated films of different refractive indices and prevent light reflection through interference. Specifically, AR films have a multilayer structure with laminated low-refractive index layers and high-refractive index layers. The low-refractive index layer is, for example, composed of silicon dioxide (SiO2) with a refractive index of about 1.43 to 1.47. The high-refractive index layer is made of a material with a higher refractive index than the low-refractive index layer, such as zirconium oxide (ZrO2), tin oxide (SnO2), niobium oxide (Nb2O5), tantalum oxide (Ta2O5), titanium oxide (TiO2), yttrium oxide (Y2O3), aluminum oxide (Al2O3), and mixtures thereof (e.g., indium tin oxide (ITO)). However, the outermost layer of the multilayer AR film is always configured as a low-refractive index layer (e.g., a SiO2 layer). By coating such an AR film, the visibility of the image seen through eyeglass lenses can be improved. AR films can be formed, for example, by applying ion beam assisted vapor deposition.

[0072] The above process is used to manufacture spectacle lens 1 with the above structure.

[0073] (3) Mold manufacturing method

[0074] Next, the manufacturing method of the molding die used in the substrate forming step will be explained.

[0075] As mentioned above, there are various types of resin materials used to form lens substrates, depending on their refractive index, composition, etc. Therefore, in the substrate molding process, regardless of the type of resin material, appropriate casting molding using molds is required. However, when using metal molds (metal molds) as molding dies, there is a concern that the resin material will be limited to polycarbonate resin due to manufacturing issues. Specifically, for example, if it is thermoplastic polycarbonate resin, molding can be achieved quickly via injection molding, and mass production of lens substrates can be handled without preparing a large number of expensive metal molds. However, resin materials other than polycarbonate resin are polymeric (thermosetting), and the reaction takes time, thus metal molds are time-consuming, requiring a large number of expensive metal molds for mass production of lens substrates. In particular, for lens substrate materials, metal molds with transfer surfaces for forming fine and precise convex portions are expensive due to their difficulty in manufacturing. Therefore, when using metal molds, the resin material is often limited to polycarbonate resin.

[0076] If a glass mold made of glass material is used as the molding mold, it is relatively easier to prepare a large number of glass molds compared to metal molds. That is, if a glass mold is used, the resin material is not limited to polycarbonate resin, and any kind of resin material can be used. However, for glass molds, due to the brittleness and difficulty in processing of glass material, processability needs to be considered. In particular, when the optical surface has a complex shape, such as a molding mold forming a concave portion corresponding to the defocusing portion 4, it is not necessarily easy to form the complex shape with high precision, and it is not desirable to require complex processing for this purpose. That is, considering the manufacturing cost of the spectacle lens 1, it is desirable that the molding mold can be easily formed even if the optical surface has a complex shape.

[0077] Based on the above, in this embodiment, the molding die is manufactured in the following sequence.

[0078] Figure 4 This is a flowchart illustrating an example of the sequence of the mold manufacturing method according to this embodiment.

[0079] As shown in the figure, in this embodiment, a molding die for forming the spectacle lens 1 is manufactured via at least a glass mold preparation step (step 11, hereinafter referred to as "S"), a concave part forming step (S12), and a surface shape grinding step (S13).

[0080] In the glass mold preparation step (S11), a glass mold made of glass material is prepared as a molding die for manufacturing spectacle lens 1. The glass mold prepared here has a surface shape that does not correspond to the formation of the defocusing portion 4. That is, glass molds are prepared for forming the object-side surface 2 and the eyeball-side surface 3 respectively; for the object-side surface 2, a surface shape without the defocusing portion 4 is prepared (i.e., a surface shape corresponding to the formation of the base region 5). The surface shape of the base region 5 can be determined based on the wearer's prescription information. If the surface shape corresponds to the formation of the base region 5, it can be achieved without complex processing.

[0081] Next, in the concave part forming step (S12), a short pulse laser is irradiated onto the forming surface of the optical surface of the prepared glass mold that corresponds to the surface shape of the substrate region 5, thereby forming a concave part corresponding to the defocused part 4 on the forming surface.

[0082] The short-pulse laser referred to here can be a laser with a pulse width of less than 1 nanosecond. Specifically, a short-pulse laser has, for example, a pulse width of 0.1 picoseconds or more and less than 100 picoseconds. Preferably, the pulse width is 0.1 picoseconds or more and less than 30 picoseconds, and more preferably 0.1 picoseconds or more and less than 15 picoseconds. There is no particular limitation on the lower limit of the pulse width, as long as it exceeds 0 femtoseconds, but as mentioned above, for example, 0.1 picoseconds or more (including 1 picosecond or more) can be preferred.

[0083] The wavelength of the short-pulse laser is, for example, THG (third harmonic generation) at 355 nm or SHG (second harmonic generation) at 532 nm. However, it is not limited to these and can also be, for example, a fundamental wavelength of 1064 nm or FHG (fourth harmonic generation) at 266 nm. The pulse energy of the short-pulse laser is, for example, 0.1 μJ or more and 30 μJ or less (maximum approximately 60 μJ) at 50 kHz. The beam diameter of the short-pulse laser is, for example, 10 μm or more and 30 μm or less.

[0084] If such a short-pulse laser is used, non-heating processing is possible because the pulse width is within the aforementioned range.

[0085] Non-thermal processing, also known as ablation, is a technique that utilizes the multiphoton absorption phenomenon of short-pulse lasers to perform processing without heating. More specifically, non-thermal processing minimizes thermal effects around the processing area. Even materials that require extremely high temperatures to melt at atmospheric pressure can be instantly melted, evaporated, and dispersed at the point of irradiation by a short-pulse laser, thus achieving removal. According to this non-thermal processing, the molten portion evaporates, disperses, and is removed instantaneously, resulting in minimal thermal effects on the surrounding area and allowing processing to be performed while suppressing thermal damage (such as deformation caused by heat).

[0086] That is, by using short-pulse lasers, the oscillation ends before the heat effect is transferred, thus enabling non-heating processing with almost no heat effect. Therefore, even glass molds made of glass materials that are difficult to process can be partially removed to form concave portions by irradiating them with short-pulse lasers.

[0087] Irradiation with short-pulse lasers, for example, is performed in a pulse-splitting mode.

[0088] Pulse segmentation mode is a mode in which a short pulse laser is used to irradiate a location (irradiation area) while simultaneously using a galvanometer scanner or similar device to move the irradiation position of each irradiation area in two or three dimensions.

[0089] In this pulse-splitting mode, even if the beam diameter of the short-pulse laser is, for example, 10 μm or more and 30 μm or less, a concave portion corresponding to the defocused portion 4 with a diameter of, for example, 0.6 to 2.0 mm when viewed from above can be formed. That is, when forming the concave portion, a concave portion is formed by multiple irradiation areas of the short-pulse laser.

[0090] Here, we will describe in detail the multiple irradiation zones of the short-pulse laser.

[0091] Figure 5 This is an explanatory diagram showing an example of the configuration of multiple irradiation zones of a short-pulse laser in the mold manufacturing method according to this embodiment.

[0092] In the illustrated example, when forming the concave portion 7, which is circular from top view, multiple irradiation areas 8 of the short-pulse laser are arranged in a circle to form an irradiation area column, and multiple irradiation area columns with different circumferential diameters are arranged in a concentric circle configuration. Here, it is assumed that the size (diameter) of each individual irradiation area is the same. Furthermore, the center of the concentric circles formed by the irradiation area columns can correspond to the optical center of the spectacle lens 1 to be obtained.

[0093] In this configuration of multiple irradiation zones 8, each irradiation zone 8 constituting a circumferential irradiation zone row overlaps with adjacent irradiation zones 8 having overlapping portions. Since the overlapping portions of each irradiation zone 8 are repeatedly irradiated with short-pulse laser, the irradiation energy increases compared to the case of a single irradiation zone without overlap, and the processing depth of non-heated processing can be increased. This means that the formation depth of the concave portion 7 can be controlled by the overlap of the individual irradiation zones 8. For example, if the formation depth of the concave portion 7 is to be increased (deepened), the overlap of the individual irradiation zones 8 should be increased; conversely, if the formation depth of the concave portion 7 is to be decreased (shallowed), the overlap of the individual irradiation zones 8 should be decreased or overlap should be avoided.

[0094] Specifically, in this embodiment, when the defocusing portion 4 has a spherical shape and a concave portion 7 corresponding to the spherical shape is formed, each irradiation area 8 can be irradiated while changing the overlap amount, such that the overlap amount of each irradiation area 8 increases from the outer edge side to the center side of the concave portion 7. That is, on the outer edge side of the concave portion 7, the overlap amount between each irradiation area 8 decreases or does not overlap, and the arrangement spacing of the irradiation areas 8 gradually narrows towards the center of the concave portion 7 to increase the overlap amount. As a result, the forming depth gradually increases (deeperses) from the outer edge side to the center side of the concave portion 7, and as a result, a spherical concave portion 7 can be formed.

[0095] In addition, Figure 5 In the illustrated configuration of the irradiation areas 8, to make the irradiation areas 8 more densely packed toward the center of the concave portion 7, the concave portions overlap in the circumferential direction (along the direction of the circumferentially shaped irradiation area row) but do not overlap in the radial direction of the concave portions 7. However, the present invention is not limited to this. The irradiation areas 8 may overlap in both the circumferential and radial directions. Furthermore, the manner in which the irradiation areas 8 overlap can be appropriately set according to the surface shape of the concave portion 7 to be formed, and is not limited to a specific manner.

[0096] Furthermore, this example illustrates controlling the formation depth of the concave portion 7 by overlapping each irradiation area 8, but the present invention is not necessarily limited to this. For example, the formation depth and shape of the concave portion 7 can be controlled by adjusting the laser power, frequency, number of irradiation areas, and number of irradiations of each irradiation area 8. However, in this case, controlling each irradiation area 8 may become complex. Therefore, it is preferable to control the overlap amount by controlling the position of each irradiation area 8, thereby controlling the formation depth of the concave portion 7.

[0097] In the concave portion forming step (S12), the aforementioned short-pulse laser irradiation is sequentially performed on multiple locations where the concave portion 7 is to be formed. Thus, in the glass mold, the concave portion 7 for forming the defocused portion 4 is formed at multiple locations. The concave portions 7 for forming the defocused portion 4 can be provided on the molding surface of the glass mold, and the number can be 200 to 600, more specifically 300 to 500. The irradiation zone rows forming the aforementioned concentric circles can be set to approximately 5 to 15 rows.

[0098] Next, a surface shape grinding step (S13) is performed. In the surface shape grinding step (S13), the surface shape of the concave portion 7 is adjusted by grinding the concave portion 7 after short-pulse laser irradiation. Specifically, for example, an abrasive such as cerium oxide is used to grind the surface to be processed in the concave portion forming step (S12), thereby making the surface roughness of the surface to be processed smooth.

[0099] By performing this surface shape grinding step (S13), even when irradiated with a short-pulse laser, there is no need to worry about the surface roughening caused by this laser processing, and the surface shape of the concave portion 7 can be adjusted. Therefore, it is very suitable as a molding die for forming the defocused portion 4.

[0100] Through the above steps (S11 to S13), a glass mold with the recessed portion 7 is obtained. This glass mold is used as a molding die for manufacturing the spectacle lens 1 as described above. Specifically, the spectacle lens 1 having the defocusing portion 4 is manufactured by casting using this glass mold for forming the object side surface 2, a glass mold for forming the eyeball side surface 3 arranged with a predetermined gap, and resin material poured between the various molds.

[0101] At this time, various types of resin materials can be applied. That is, since a glass mold made of glass material is used, any kind of resin material can be appropriately cast. Therefore, as the resin material, any type of resin material in the range of 1.40 or higher and 1.74 or lower can be used, and high refractive index materials with a refractive index preferably of 1.50 or higher, more preferably 1.60 or higher, can also be used, and casting can be appropriately performed in any case.

[0102] (4) Effects of this implementation method

[0103] According to this embodiment, one or more of the effects shown below can be obtained.

[0104] (a) In this embodiment, a glass mold made of glass material is prepared as a molding die for manufacturing a spectacle lens 1 having a defocusing portion 4, and a short-pulse laser is irradiated onto the forming surface of the optical surface of this glass mold to form a concave portion 7 corresponding to the defocusing portion 4. Thus, by using a short-pulse laser, concave portions can be easily formed even in a glass mold made of a difficult-to-process glass material without complex processing. Furthermore, since a glass mold is used, any kind of resin material can be appropriately cast.

[0105] Therefore, according to this embodiment, even if the optical surface to be formed has a complex shape, a molding die for manufacturing the optical surface can be easily obtained, and the molding die can be compatible with various resin materials.

[0106] (b) In this embodiment, a concave portion 7 is formed by irradiation areas 8 of multiple short-pulse lasers, and the formation depth of the concave portion 7 is controlled by the overlap of the individual irradiation areas 8. Therefore, the formation of concave portions 7 with complex three-dimensional shapes can be easily handled. Furthermore, since the overlap amount can be controlled by controlling the position of each irradiation area 8, and variable control of the energy of each irradiation area is not required, the control of each irradiation area 8 can be prevented from becoming complicated, and damage to the processed parts can also be prevented.

[0107] (c) In this embodiment, multiple irradiation areas 8 are irradiated while the overlap amount is changed, such that the overlap amount of each irradiation area 8 increases from the outer edge side of the concave portion 7 towards the center side. Therefore, it is easy to make the forming depth gradually increase (deeper) from the outer edge side of the concave portion 7 towards the center side, which is very effective for forming a concave portion 7 with a generally spherical shape.

[0108] (d) In this embodiment, the concave portion 7 after short-pulse laser irradiation is ground to adjust the surface shape of the concave portion 7. Therefore, even when irradiated with a short-pulse laser, there is no need to worry about the surface roughening caused by this laser processing, the surface shape of the concave portion 7 can be adjusted, and it is very suitable as a molding die for forming the defocused portion 4.

[0109] (e) In this embodiment, a glass mold having a concave portion 7 is used as a molding mold to mold the resin material, thereby manufacturing a spectacle lens 1 having a defocusing portion 4 on at least one optical surface. Therefore, even for a spectacle lens 1 having a defocusing portion 4, since a glass mold is used, various resin materials can be used to manufacture the spectacle lens 1. In particular, even if a high refractive index material that is difficult to mold with a metal molding mold (metal mold) is used, it is possible to use such a high refractive index material to manufacture a spectacle lens 1 having a defocusing portion 4.

[0110] (5) Variations, etc.

[0111] Although embodiments of the present invention have been described above, exemplary embodiments of the invention have been disclosed above. That is, the scope of the present invention is not limited to the exemplary embodiments described above, and various modifications can be made without departing from the scope of the invention.

[0112] In the above embodiments, the case of manufacturing a spectacle lens 1 having a defocusing portion 4 on the object-side surface 2 has been described as an example; however, the present invention is not limited thereto. That is, the defocusing portion 4 can be formed on at least one optical surface, and can be formed on the eyeball-side surface 3, or on both the object-side surface 2 and the eyeball-side surface 3.

[0113] In the above embodiments, the case where the spectacle lens 1 with the defocus portion 4 is a myopia progression suppression lens has been described as an example; however, the present invention is not limited thereto. That is, as long as the spectacle lens 1 has a convex defocus portion 4 on at least one optical surface, it can be applied in exactly the same way even if it is used for purposes other than achieving the effect of suppressing myopia.

[0114] In the above embodiments, the optical component is a spectacle lens, but the present invention is not limited thereto. That is, optical components other than spectacle lenses can also be applied in the same manner.

[0115] [Symbol Explanation]

[0116] 1…Spectacle lens (optical component); 2…Object side surface (optical surface); 3…Eyeball side surface (optical surface); 4…Defocused area; 5…Base region; 6…Defocused area; 7…Concave part; 8…Illumination area.

Claims

1. A spectacle lens having optical surfaces located on the object side and the eyeball side, respectively. The spectacle lens has, on at least one of the optical surfaces, a defocused region having a defocusing portion formed thereon and a base region without the defocusing portion formed thereon. The defocusing portion is formed at multiple locations. When the defocusing part has an X-fold rotationally symmetric shape and the configuration of the defocusing part is Y-fold rotationally symmetric, both X and Y are multiples of 3, or both X and Y are multiples of 4.

2. The spectacle lens according to claim 1, wherein, The position where light passing through the spectacle lens is focused by the base region and the position where light passing through the spectacle lens is focused by the defocusing portion are configured to be different from each other.

3. A method for manufacturing a mold, wherein the method is a method for manufacturing a forming mold, the forming mold being used to form a lens substrate constituting a spectacle lens according to claim 1 or 2, the method comprising: The step of preparing a glass mold made of glass material as a molding mold, the molding mold being used to manufacture a lens substrate having a convex defocusing portion on at least one optical surface; The step of irradiating the forming surface of the optical surface in the glass mold with a short-pulse laser to form a concave portion corresponding to the defocused portion.

4. The mold manufacturing method according to claim 3, wherein, The concave portion is formed by multiple irradiation zones of the short-pulse laser, and the formation depth of the concave portion is controlled by the overlap of each irradiation zone.

5. The mold manufacturing method according to claim 4, wherein, Irradiation of the plurality of irradiation areas is performed while the overlap amount is changed, such that the overlap amount of each irradiation area increases from the outer edge side to the center side of the concave portion.

6. The mold manufacturing method according to any one of claims 3 to 5, wherein, The mold manufacturing method includes the step of adjusting the surface shape of the concave portion by grinding the concave portion after it has been irradiated by the short pulse laser.

7. A method for manufacturing spectacle lenses, wherein, A spectacle lens having a defocusing portion on at least one optical surface is manufactured by molding a resin material using a molding die obtained by the molding method according to any one of claims 3 to 6.

8. The method for manufacturing spectacle lenses according to claim 7, wherein, The resin material is made of a material with a refractive index of 1.40 or higher.

9. The method of manufacturing an eyeglass lens according to claim 7 or 8, the eyeglass lens having: a base region formed such that transmitted light is focused at a predetermined position within the eye; and a defocus region formed such that the transmitted light is focused by the defocus portion at a position defocused from the predetermined position.

Images