Lens manufacturing method, lens, mold manufacturing method, mold, mold-identifying method, and mold-identifying device

Abstract

Provided are a lens manufacturing method and technology related thereto, said method being a method for manufacturing a lens having a first main surface and a second main surface by curing a lens material that is located between a first mold 2 having a first transfer surface 2a serving as a transfer source having the shape of the first main surface and a second mold 3 having a second transfer surface 3a serving as a transfer source having the shape of the second main surface, wherein manufactured is a lens onto which mold-identifying information has been transferred as a result of a mold-identifying mark for identifying at least one of the first mold 2 and the second mold 3 being marked, as a transfer mark, onto at least one of the first transfer surface 2a and the second transfer surface 3a, and the lens material that is located between the first mold 2 and the second mold 3 being cured.

Description

Lens manufacturing method, lens and mold manufacturing method, mold, mold specifying method, and mold specifying device

[0001] The present invention relates to a lens manufacturing method, a lens and mold manufacturing method, and a mold, and in particular to a lens manufacturing method, a lens and mold manufacturing method, a mold and mold specifying method, and a mold specifying device when the lens is a lens for glasses.

[0002] Patent Document 1 describes a method for manufacturing eyeglass lenses from lens material, which includes a marking step in which an identification information mark for identifying the eyeglass lens and a processing information mark used when processing the lens material are marked on the convex surface of the lens material by forming a hole or groove with a laser, and a concave surface cutting step in which the processing information mark is read and the concave surface of the lens material is cut based on the read processing information mark.

[0003] Patent document 2 describes a method for permanently storing information for individualizing a spectacle lens on a glass or plastic body of a spectacle lens, without the need to exceed the number of permanent marks specified in the DIN EN ISO 8980-2:2004 standard.

[0004] The information for individualizing spectacle lenses described in Patent Document 2 is said to provide the following advantages: It makes it possible to prevent mix-ups between spectacle lenses or spectacle lens blanks in a manufacturing process in which tens of thousands of spectacle lens blanks typically pass through per day. The individualized information for spectacle lenses also makes it easier to detect errors during the manufacturing process. The manufacturing of spectacle lenses can also be more easily automated by individualizing the spectacle lenses and storing the information in the spectacle lenses, since each individual glass or plastic body can be uniquely identified before, during, or after each step in the manufacturing process, making so-called batch tracking possible. Furthermore, the information for individualizing each spectacle lens makes it possible to simplify and improve the quality control of spectacle lenses throughout the manufacturing process.

[0005] WO2019 / 003343 Pamphlet WO2013 / 092987 Pamphlet

[0006] Through intensive research by the present inventors, the following problems have been discovered.

[0007] Lenses having a first main surface and a second main surface (e.g., lenses for glasses) are mostly manufactured using molds due to the need for mass production. Specifically, lenses can be manufactured by hardening a lens material between a first mold having a first transfer surface from which the shape of the first main surface is transferred, and a second mold having a second transfer surface from which the shape of the second main surface is transferred. Hereinafter, the first mold and / or the second mold will be simply referred to as molds. The mold reference numerals will be used to represent the first mold.

[0008] When lenses are manufactured using the manufacturing method described in the above paragraph, if there is a defect in the mold (e.g., the transfer surface), the defect will naturally be transferred to the lens. If the defect is not noticed, lenses with the defect, i.e., defective products, will continue to be produced.

[0009] Currently, even if a defective product with a defect caused by the mold is found, there is no way to identify the mold that was used to manufacture the defective product from the defective product.

[0010] Of course, one method is to visually inspect the mold each time it is used, cleaned, or reused to detect defects caused by the mold. However, the presence or absence of defects in a mold is an issue only on the transfer surface; other non-transfer surfaces may be dirty or cloudy due to the roughness of the non-transfer surface. In such a state, it is not easy to visually detect defects, even on the transfer surface. Furthermore, such visual inspections are only effective in preventing defective products from occurring, and they do not identify the mold if a defective product does occur.

[0011] In both Patent Documents 1 and 2, marking is performed on the lens blank after the lens material has hardened. On the other hand, there is no mention of identifying the mold used to manufacture a defective lens when manufacturing lenses using the manufacturing method described in the above paragraph.

[0012] To begin with, neither Patent Document 1 nor Patent Document 2 mentions anything about managing the molds used when hardening the lens material, regardless of whether or not defective products are produced.

[0013] In lens production, from the viewpoint of productivity, multiple molds of the same type are often prepared, and these molds may be used simultaneously or at multiple different production sites. Therefore, it is difficult to identify the mold used for molding the lens substrate solely from the shape, etc. of the lens substrate after molding. Therefore, the present inventors have discovered a problem of identifying the mold when a defect suspected to be caused by the mold is discovered during a visual inspection of the lens substrate after molding.

[0014] Furthermore, the present inventors have found that it is important to identify a mold from lenses manufactured using that mold, regardless of whether or not defective products are produced.

[0015] An object of one embodiment of the present invention is to provide a technique for identifying a mold from a lens manufactured using the mold. A specific embodiment of the present invention is to provide a technique for identifying a mold that produced a defect from a lens having a defect caused by the mold.

[0016] A first aspect is a method for manufacturing a lens having a first principal surface and a second principal surface by hardening a lens material between a first mold having a first transfer surface from which the shape of the first principal surface is transferred, and a second mold having a second transfer surface from which the shape of the second principal surface is transferred, wherein a mold-identifying mark that identifies at least one of the first mold and the second mold is marked as a transfer mark on at least one of the first transfer surface and the second transfer surface, and the lens to which the mold-identifying mark has been transferred is manufactured by hardening the lens material between the first mold and the second mold.

[0017] A second aspect is the method for manufacturing a lens according to the first aspect, wherein a mold-identifying mark that identifies the first mold is marked on the first transfer surface as a transfer mark.

[0018] A third aspect is a method for manufacturing a lens according to any one of the first and second aspects, comprising: a mold preparation step of preparing a mold having the mold-specific mark marked on at least one of the first transfer surface and the second transfer surface; a curing step of curing the lens material between the first mold and the second mold after the mold preparation step; and a demolding step of releasing the lens, to which the mold-specific mark has been transferred, from the first mold and the second mold after the curing step.

[0019] A fourth aspect is the method for manufacturing a lens according to any one of the first to third aspects, in which a mold identification mark that identifies at least one of the first mold and the second mold is marked by engraving using laser irradiation into at least one of the first transfer surface and the second transfer surface.

[0020] A fifth aspect is the method for manufacturing a lens according to any one of the first to fourth aspects, wherein the lens is a lens for glasses.

[0021] A sixth aspect is the method for manufacturing a lens according to any one of the first to fifth aspects, wherein, in the eyeglass lens, the first principal surface is a surface facing the object and the second principal surface is a surface facing the eyeball, and a mold-identifying mark that identifies the first mold is marked on the first transfer surface.

[0022] A seventh aspect is the method for manufacturing a lens according to any one of the first to sixth aspects, wherein the mold-specific mark is marked outside the area to be used as the lens for glasses.

[0023] An eighth aspect is the method for manufacturing a lens according to any one of the first to seventh aspects, wherein the mold-specific mark is arranged near the outer edge of at least one of the first transfer surface and the second transfer surface.

[0024] A ninth aspect is a method for manufacturing a lens according to any one of the first to eighth aspects, wherein the mold-specific mark arranged near the outer edge is arranged at a position where the distance from the outer edge of at least one of the first transfer surface and the second transfer surface is 0.5 to 2 mm.

[0025] A tenth aspect is a method for manufacturing a lens according to any one of the first to ninth aspects, in which a hidden mark in the eyeglass lens is marked on at least one of the first transfer surface and the second transfer surface, together with a mold identification mark that identifies at least one of the first mold and the second mold.

[0026] An eleventh aspect is the method for manufacturing a lens according to any one of the first to tenth aspects, wherein the mold-specific mark is an information record that can be read using an optical recognition device.

[0027] A twelfth aspect is the method for manufacturing a lens according to any one of the first to eleventh aspects, wherein the mold-specific mark is a two-dimensional code, and the two-dimensional code is formed by forming a plurality of cells constituting the two-dimensional code into recesses having at least one of a polygonal pyramid shape, a hemisphere shape, and a cone shape on at least one of the first transfer surface and the second transfer surface.

[0028] A thirteenth aspect is the method for manufacturing a lens according to any one of the first to twelfth aspects, wherein the two-dimensional code is sized to fit within a square with sides ranging from 1 to 10 mm, or a rectangle with short sides ranging from 1 to 10 mm.

[0029] A fourteenth aspect is the method for manufacturing a lens according to any one of the first to thirteenth aspects, wherein a first mold specifying mark that specifies the first mold is marked on the first transfer surface, and a second mold specifying mark that specifies the second mold is marked on the second transfer surface, and the mold specifying marks include the first mold specifying mark and the second mold specifying mark.

[0030] A fifteenth aspect is a method for manufacturing a lens according to any one of the first to fourteenth aspects, wherein the marking is formed by a pulse laser having a pulse width of femtosecond to nanosecond, and the applicable wavelength of the laser is 266 to 1064 nm.

[0031] A sixteenth aspect is a lens comprising a first principal surface and a second principal surface and a lens substrate, wherein a mold-specific mark composed of a convex portion is provided on at least the outermost surface of the lens substrate on at least either side of the first principal surface or the second principal surface.

[0032] A seventeenth aspect is the lens according to the sixteenth aspect, wherein the lens is a lens for spectacles.

[0033] An eighteenth aspect is the lens according to any one of the sixteenth to seventeenth aspects, wherein in the eyeglass lens, the first principal surface is a surface on the object side, the second principal surface is a surface on the eyeball side, and the mold-specific mark is provided on the first principal surface.

[0034] A nineteenth aspect is the lens according to any one of the sixteenth to eighteenth aspects, in which the mold-specific mark is marked outside the area to be used as the lens for glasses.

[0035] A twentieth aspect is the lens according to any one of the sixteenth to nineteenth aspects, wherein the mold-specific mark is an information record that can be read using an optical recognition device.

[0036] A 21st aspect is the lens according to any one of the 16th to 20th aspects, wherein the mold-specific mark is a two-dimensional code, and the plurality of cells constituting the two-dimensional code are configured by convex portions having at least one of a polygonal pyramid shape, a hemispherical shape, and a conical shape.

[0037] A 22nd aspect is a method for manufacturing a first mold used in manufacturing a lens having a first main surface and a second main surface, the first mold being used in manufacturing a lens by hardening a lens material between a first mold having a first transfer surface from which the shape of the first main surface is transferred, and a second mold having a second transfer surface from which the shape of the second main surface is transferred, the method including marking a first mold identifying mark that identifies the first mold on the first transfer surface as a transfer mark.

[0038] A 23rd aspect is a mold manufacturing method according to the 22nd aspect, in which the marking is a process of engraving a first mold identification mark that identifies the first mold into the first transfer surface by irradiating the first mold with a laser.

[0039] A twenty-fourth aspect is a mold used when manufacturing a lens having a first main surface and a second main surface, the mold being used when manufacturing a lens by hardening a lens material between a first mold having a first transfer surface from which the shape of the first main surface is transferred, and a second mold having a second transfer surface from which the shape of the second main surface is transferred, wherein a first mold identification mark that identifies the first mold is marked on the first transfer surface as a transfer mark.

[0040] A twenty-fifth aspect is the mold according to the twenty-fourth aspect, in which the marking is a process of engraving a first mold identifying mark that identifies the first mold by irradiating the first transfer surface with a laser.

[0041] A 26th aspect is a method for identifying a mold used in manufacturing a spectacle lens having a first main surface and a second main surface by hardening a lens material between a first mold having a first transfer surface from which the shape of the first main surface is transferred, and a second mold having a second transfer surface from which the shape of the second main surface is transferred, wherein a mold identification mark identifying the first mold is marked on the first transfer surface as a transfer mark, and at least one of the first mold and the second mold is identified from a post-transfer mold identification mark formed by transferring the mold identification mark of the first mold to the first main surface of the lens.

[0042] A 27th aspect is an apparatus for identifying a mold used in manufacturing an eyeglass lens having a first main surface and a second main surface by hardening a lens material between a first mold having a first transfer surface from which the shape of the first main surface is transferred, and a second mold having a second transfer surface from which the shape of the second main surface is transferred, wherein a mold identification mark identifying the first mold is marked on the first transfer surface as a transfer mark, and a post-transfer mold identification mark formed by transferring the mold identification mark of the first mold to the first main surface of the lens is read by a reading unit, and a database is referenced by a reference unit to identify at least one of the first mold and the second mold.

[0043] The specific contents of the lens and its manufacturing method, and the mold and its manufacturing method are applicable to the contents described above. The technical idea of ​​the present invention is also applicable to a method for identifying a mold from a lens. The technical idea of ​​the present invention is also applicable to a system (or apparatus) for identifying a mold from a lens. The content of "system" in this specification is also applicable to "apparatus."

[0044] According to one embodiment of the present invention, a mold can be identified from a lens manufactured using the mold. According to a specific embodiment of the present invention, the mold that produced the defect can be identified from a lens having a defect caused by the mold.

[0045] FIG. 1 is a schematic cross-sectional view of an assembly in which a first mold serving as an upper cover and a second mold serving as a lower cover are combined with a gasket in a method for manufacturing an eyeglass lens according to one embodiment of the present invention. FIG. 2 is a schematic diagram of the first transfer surface of the first mold. FIG. 3 is a schematic enlarged view of the vicinity of the two-dimensional code in FIG. 2. FIG. 4 is a schematic enlarged view of the two-dimensional code in FIG. 2. FIG. 5 is a schematic diagram of the second transfer surface of the second mold. FIG. 6 is a schematic plan view of an eyeglass lens manufactured using the assembly of FIG. 1. FIG. 7 is a partial enlarged view of FIG. 4. FIG. 8 is an explanatory diagram showing the trajectory of a laser scanning line as an example of engraving the two-dimensional code of FIG. 2 into the first transfer surface of the first mold. FIG. 9 is an enlarged photograph showing the two-dimensional code of FIG. 4 actually engraved into the first transfer surface of the first mold. Fig. 10 is an image acquired by a 3D shape measuring device (manufactured by ZYGO) of a quadrangular pyramidal portion actually carved into the first transfer surface of the first mold in a method for manufacturing an eyeglass lens according to one embodiment of the present invention. Fig. 11 is a schematic diagram of a mold-specific mark formed as a linear carving on the first transfer surface of the first mold. Fig. 12 is an explanatory diagram showing the trajectory of a laser scanning line when the carving process of Fig. 11 is performed on the first transfer surface of the first mold. Fig. 13 is an enlarged photograph showing the carving process of Fig. 11 , in which the carving is tapered so that the side surfaces of the carving on the first transfer surface of the first mold approach each other toward the bottom.

[0046] Hereinafter, embodiments of the present invention will be described. The following description based on the drawings is an example, and the present invention is not limited to the exemplified embodiments. In this specification, the symbol "to" indicates a value greater than or equal to a predetermined value and less than or equal to a predetermined value.

[0047] In this specification, the left-right direction in the direction facing the object-side surface of a spectacle lens (hereinafter referred to as plan view) is defined as the X direction, the up-down direction as the Y direction, and the thickness direction of the spectacle lens, which is perpendicular to the X and Y directions, as the Z direction. The Z direction is also the optical axis direction of the spectacle lens. The origin is the lens center. The lens center refers to the optical center or geometric center of the spectacle lens. This specification illustrates a case where the optical center and the geometric center approximately coincide. The right (3 o'clock direction) is defined as the +X direction, the left (9 o'clock direction) as the -X direction, the up (0 o'clock direction) as the +Y direction, the down (6 o'clock direction) as the -Y direction, the object side direction as the +Z direction, and the opposite direction (towards the back) as the -Z direction.

[0048] (Overview of Lens Manufacturing Method) FIG. 1 is a schematic cross-sectional view of an assembly 1 in which a first mold 2 serving as an upper cover and a second mold 3 serving as a lower cover are combined with a gasket 4 in a method of manufacturing an eyeglass lens that is one embodiment of the present invention.

[0049] An outline of a method for manufacturing a spectacle lens according to one aspect of the present invention is as follows. First, a lens having a first principal surface and a second principal surface is manufactured by hardening a lens material between a first mold 2 having a first transfer surface 2a from which the shape of the first principal surface is transferred, and a second mold 3 having a second transfer surface 3a from which the shape of the second principal surface is transferred.

[0050] (Lens) The term "lens" used in this specification is not limited as long as it has a first principal surface and a second principal surface, one of which serves as a light entrance surface and the other as a light exit surface.

[0051] The lens may be a lens for glasses. In this case, one of the first and second principal surfaces is the object-side surface where light enters, and the other is the eye-side surface where light exits.

[0052] In this case, an assembly 1 is obtained by combining, for example, a first mold 2, which serves as an upper cover, and a second mold 3, which serves as a lower cover, with a cylindrical container called a gasket 4. This forms an internal space. A monomer, which is the raw material for the lens material, is injected into this internal space through an injection port (not shown) provided on the cylindrical side surface of the gasket 4. This internal space is also called a cavity CA.

[0053] This lens material is, for example, a thermosetting resin. In this case, the monomer is hardened by heating the assembly 1 containing the monomer in the internal space. The lens is obtained by releasing this hardened material from the assembly 1. Thermoplastic resin may also be used as the lens material.

[0054] Furthermore, when a photocurable resin is used as the lens material, gasket 4, first mold 2 and / or second mold 3 of assembly 1 may be made transparent, and light may be irradiated onto the monomer through this transparent member.

[0055] The lens material may also be a pellet-shaped resin material called a preform. When a preform is used, the gasket 4 is not used, and the preform may be placed between the first mold 2 and the second mold 3, and the preform may be pressed and molded by both molds 2. There are no particular restrictions on the use of the lens thus obtained, and it may be an optical lens used in an imaging device or display (HMD, etc.) including a smartphone, in addition to a lens for glasses. Alternatively, molding may be applied in which, after the relative positions of the first mold 2 and the second mold 3 have been determined, a cavity is formed by wrapping tape instead of a gasket.

[0056] In this specification, the term "lens" refers to a lens for eyeglasses.

[0057] As used herein, "spectacles lenses" include lenses with a hard coating and an anti-reflection coating applied to a lens substrate, intermediate lenses with only a portion of various coatings applied to the lens substrate, and the lens substrate itself. Furthermore, the lens may have optical surfaces on both the object-side and eyeglass-side surfaces, or may have an optical surface on only one surface (e.g., the object-side surface) and no optical surface on the eyeball-side surface (a semi-finished lens, as described below). Furthermore, as used herein, "spectacles lenses" includes both pre-edged lenses before cutting to the shape of the frame, and post-edged lenses after such cutting. However, because providing a mold-specific mark on the inside of the frame affects the wearer's field of vision and the appearance of the spectacle lens, this specification primarily refers to pre-edged lenses as spectacle lenses. In this specification, "spectacles lenses" are also referred to as "spectacles lenses."

[0058] The spectacle lenses described herein have an object-side surface and an eyeball-side surface. This description exemplifies a case in which the previously described first principal surface corresponds to the object-side surface and the second principal surface corresponds to the eyeball-side surface. That is, in the first mold 2, the first transfer surface 2a corresponds to the object-side surface, and in the second mold 3, the second transfer surface 3a corresponds to the eyeball-side surface. Of course, the first principal surface may be interchanged with the eyeball-side surface and the second principal surface may be interchanged with the object-side surface.

[0059] The "object-side surface" of a spectacle lens is the surface that faces the object when a wearer wears eyeglasses equipped with the spectacle lens, and the "eyeball-side surface" is the opposite, i.e., the surface that faces the eye when a wearer wears eyeglasses equipped with the spectacle lens. This relationship also applies to the lens substrate (a molded lens material) that forms the basis of the spectacle lens. In other words, the lens substrate also has an object-side surface and an eyeball-side surface. A meniscus shape may be adopted for the spectacle lens, with the object-side surface being convex and the eyeball-side surface being concave, and a first mold 2 and a second mold 3 having shapes corresponding to this meniscus-shaped spectacle lens may be used. In this specification, examples of meniscus-shaped spectacle lenses will be mainly given.

[0060] (Mold 2) There are no limitations on the material of the mold 2 as long as it is possible to form a mold-specific mark as a transfer mark on the first transfer surface 2a. Note that, since the transfer surface of the mold 2 in this embodiment is formed with a transfer mark to be transferred to the lens substrate when the lens substrate is molded, it is desirable that the material of the mold 2 be one on which a precise three-dimensional pattern can be formed by processing using laser irradiation as described below. Hereinafter, for convenience, the formation of a three-dimensional transfer mark on the mold transfer surface will also be referred to as "engraving."

[0061] There is no limitation on the type of glass, nor on the refractive index of the glass, but for example, crown glass is preferably used.

[0062] (Mold Identification Mark) FIG. 2 is a schematic diagram of the first transfer surface 2a of the first mold 2. Dotted lines are used to highlight specific locations. The dashed-dotted lines in FIGS. 2, 5, and 6 indicate the left-right direction (X direction) and the up-down direction (Y direction). FIG. 3 is a schematic enlarged view of the vicinity of the two-dimensional code in FIG. 2. FIG. 4 is a schematic enlarged view of the two-dimensional code in FIG. 2. FIG. 5 is a schematic diagram of the second transfer surface 3a of the second mold 3. The dotted lines are used for emphasis and do not represent the actual physical configuration. FIG. 6 is a schematic plan view of an eyeglass lens manufactured using the assembly 1 of FIG. 1. FIG. 7 is a partial enlarged view of FIG. 4.

[0063] In a method for manufacturing an eyeglass lens according to one aspect of the present invention, a mold-specifying mark that identifies at least one of the first mold 2 and the second mold 3 is determined in advance, and the mold-specifying mark is marked on at least one of the first transfer surface 2 a and the second transfer surface 3 a. Then, when the lens material is hardened between the first mold 2 and the second mold 3, the lens is manufactured in which the mold-specifying mark is transferred to the lens material that is in close contact with the first mold 2 and the second mold 3.

[0064] In this specification, a "T" is added to the end of the symbol for a mark transferred to the main surface of a lens, such as a transferred mold-specific mark, to distinguish between marks formed on the mold and marks transferred to the main surface of the lens. Examples are given below: First mold-specific mark (two-dimensional code) 51T transferred to the object-side surface of the eyeglass lens; Second mold-specific mark (two-dimensional code) 52T transferred to the eyeball-side surface of the eyeglass lens. The following marks are unrelated or only vaguely related to direct mold identification, and are referred to as "lens characteristic marks" in this specification. These lens characteristic marks are usually formed as hidden marks, and are therefore also referred to as hidden marks. This does not exclude mold-specific marks that are difficult to see, similar to lens characteristic marks. However, preferably, a reading operation using a reading unit (described below) is performed, and the mold-specific mark is therefore provided outside the frame. For this reason, it is preferable that the mold-specific mark be a non-hidden mark. In this specification, "transfer mark" may include not only mold-specific marks but also the following lens characteristic marks. Lens type mark 60T Alignment reference mark 31aT Alignment reference mark 32aT Addition power indication mark 31bT Addition power indication mark 32bT Identification mark 35T Identification number 35AT Arc portion 35BT

[0065] The mold-specific mark is formed as a transfer mark on at least one of the first mold 2 and the second mold 3. For example, it can be a three-dimensional mark with irregularities formed on the mold surface, and preferably is a mark formed by engraving with laser irradiation, as will be described later.

[0066] Information for identifying the mold (hereinafter also referred to as mold identification information) can be obtained directly or indirectly from the mold identification mark. There are no limitations on the content of the mold identification information. For example, in the case of marking the first transfer surface 2a of the first mold 2, the information may include at least one of the following pieces of information. The mold identification information may be information that can at least identify and identify the individual mold: - Information for identifying the individual mold (serial number, etc.); - Mold production location (country and / or region); - Lot number; Date and time of mold production; Parameters related to the shape of the transfer surface (base curve, mean sphere, whether spherical or aspherical, information related to use, etc.); - Mold storage location; - Mold manufacturer. The term "directly" refers to the mold identification information being included in the mold identification mark. The term "indirectly" refers to the mold identification information not being included in the mold identification mark itself, but being obtained by reading the mold identification mark (e.g., displayed on a screen).

[0067] Mold-related information such as mold use history linked to the individual identification information may be stored in a recording medium (such as a server) and updated for information management. Examples of information stored in a recording medium linked to mold-specific information include the information described in the above paragraph as well as the following. Mold-related information may include at least one of the following: Number of times the mold has been used (or usage history) Information on other molds, gaskets, and molding equipment used at the same time as the mold; History of defects or spurious results, and defect correction history; Other points to note when using the mold.

[0068] The above can be briefly summarized as follows: The transfer marks provided on the mold include mold-specific marks and may also include lens characteristic marks as hidden marks. Mold-specific information can be obtained directly or indirectly from the transferred mold-specific marks on the lens that are formed by transferring the mold-specific marks on the mold. Of course, mold-specific information can also be obtained directly or indirectly from the mold-specific marks on the mold. Mold-related information linked to this mold-specific information may also be obtained.

[0069] The mold-specific mark may be a letter, a symbol, and / or a number, which will hereinafter be simply referred to as a character string.

[0070] The mold-identifying mark may be readable by the naked eye when enlarged as necessary. However, it is anticipated that a large amount of information may be required to identify the specific mold 2 (first mold 2 in this case) used in manufacturing the lens. For this reason, it is preferable that the mold-identifying mark is an information record that can be read using an optical recognition device.

[0071] The code may be either a one-dimensional code or a two-dimensional code. One-dimensional codes include barcodes. Two-dimensional codes are codes that record information using an arrangement of cells D (hereinafter, reference numbers omitted) arranged vertically and horizontally, and include QR Code (registered trademark) and data matrix.

[0072] An example of an "information record readable using an optical recognition device" is a code that is not a character string. An example of such an optical recognition device is a scanner (e.g., a QR Code (registered trademark) reader). An optical recognition device may be one that has the function of automatically recognizing the information record (e.g., a QR Code (registered trademark)) in an image captured by an imaging element.

[0073] The code is preferably a two-dimensional code that can store a lot of information in a small area. Of course, a character string and a non-character string (e.g., a code) may be combined, but if the mold-identifying mark is a two-dimensional code, the mold 2 can be identified simply by reading the two-dimensional code. In other words, it is preferable that the mold-identifying mark (especially the code) correspond one-to-one with the mold 2 actually used.

[0074] When a two-dimensional code is employed, the portions that make up the two-dimensional code (the multiple black square portions in a plan view in FIG. 4 , hereinafter referred to as cells) are engraved into the first transfer surface 2 a in a predetermined arrangement. Each cell of the two-dimensional code is recessed relative to the unrecessed base portion of the first transfer surface 2 a. Lens material fills these recesses, and by transferring these recesses, corresponding convex portions (protrusions) are formed on at least the first main surface of the lens substrate of the manufactured lens. These convex portions constitute each cell of the two-dimensional code. As a result, the lens substrate (e.g., an eyeglass lens) is provided with a mold-specific mark. In the two-dimensional code illustrated in FIG. 4 , specific information is recorded by an arrangement of 12 cells in both the vertical and horizontal directions.

[0075] There are no limitations on the dimensions of the engravings in the first transfer surface 2a in a plan view. In the case of a one-dimensional code, the short side may be, for example, 1 to 10 mm, and in the case of a two-dimensional code, the shape may be, for example, a square with a side ranging from 1 to 10 mm or a rectangle with a short side ranging from 1 to 10 mm, and preferably, a square with a side ranging from 1 to 5 mm or a rectangle with a short side ranging from 1 to 10 mm. Furthermore, when engraving a character string, it is preferable that the height of each character be approximately 1 to 10 mm.

[0076] It is preferable to determine the depth of the recesses (or irregularities) so that the lens substrate is sufficiently filled into the recesses during lens molding and a reverse image of the recesses is accurately formed on the lens substrate. For example, the dimension in the depth direction can be 100 μm or less. For example, the depth of the recesses can be in the range of 10 to 100 μm, more specifically, 10 to 80 μm.

[0077] Furthermore, the shape of the depth of the recess preferably encompasses the shape of the recess entrance relative to the non-recessed base portion of the first transfer surface 2a in a plan view. In other words, it is preferable that the recess sides approach each other toward the bottom. For example, the recesses can be formed in a tapered shape with inclined sides. To form the above-described two-dimensional code, each cell can be formed with a recess whose depth increases toward the center. Examples include polygonal pyramids such as square pyramids, hemispherical recesses, and mortar-shaped (conical) recesses. The shapes of each cell may be different, or multiple cells may be formed by combining the shapes listed above. A flat bottom may be formed near the center of the recess.

[0078] Alternatively, when forming linear recesses for forming character strings, the recesses may be shaped so as to become deeper as they approach the center in the line width direction.

[0079] The above-described excavation ensures excellent releasability when the lens substrate is released from the first mold 2. Furthermore, as will be described later, when excavating by laser irradiation, the side surface shape can be precisely controlled in forming the excavated shape described above, which has the advantage of providing particularly good releasability.

[0080] The mold identification mark may be formed by regularly engraved cells, like Braille. Two-dimensional codes are also included in this example. Ultimately, it is sufficient that the regularity of the cell arrangement differs for each mold 2 actually used. Specifically, if the regularity of the engraved cell arrangement (i.e., the arrangement pattern) can be linked to the mold 2 actually used in a one-to-one relationship, it is possible to identify the mold 2 actually used from the convex portions present in the resulting lens (e.g., originating from the concave cells of the mold 2). On the other hand, a code (especially a two-dimensional code) is preferable because it requires only a scanner to read the convex portions present in the lens or multiple cells of the mold 2, greatly simplifying the work involved.

[0081] Incidentally, there is a reason why the method for manufacturing an eyeglass lens according to one aspect of the present invention states "a mold-identifying mark that identifies 'at least one of the first mold 2 and the second mold 3'."

[0082] For example, when manufacturing a so-called semi-finished eyeglass lens, the object-side surface obtained by the first transfer surface 2a of the first mold 2 typically constitutes an optical surface based on a desired design. Furthermore, if any surface processing is performed on this surface, it is the formation of a hard coat film or the like, and no surface processing such as cutting is performed. Therefore, if a mold-specific mark is engraved into the first transfer surface 2a of the first mold 2 by carving, the mold-specific mark transferred to the object-side surface of the eyeglass lens will remain on the object-side surface, whether the object-side surface of the lens substrate is exposed or a film is formed on the object-side surface.

[0083] On the other hand, the eyeball-side surface obtained by second transfer surface 3a of second mold 3 is subjected to cutting (e.g., NC machining) and polishing in subsequent processes to achieve the desired prescription value, astigmatism distribution, refractive power error distribution, etc., and therefore may not be molded as an optical surface based on the design. Even if a mold-specific mark is engraved into second transfer surface 3a of second mold 3, in the case described in the above paragraph, no mold-specific mark will ultimately remain on the eyeball-side surface of the eyeglass lens. In that case, the mold-specific mark of first mold 2 may be engraved and marked only into first transfer surface 2a of first mold 2.

[0084] On the other hand, if it is still desired to leave a mold-specific mark on the eyeglass lens indicating that the second mold 3 was used for the eyeglass lens (semi-finished lens), the mold-specific marks of the first mold 2 and the second mold 3 can be engraved and marked on the first transfer surface 2a of the first mold 2.

[0085] In the above-mentioned semi-finished lenses, the surface facing the object is usually not subjected to surface treatment such as cutting, but this relationship can be reversed. In other words, the surface of the lens substrate facing the eyeball may not be subjected to surface treatment such as cutting.

[0086] On the other hand, in the case of eyeglass lenses (so-called cast lenses) in which no surface processing such as cutting is performed on either the object-side surface obtained by the first transfer surface 2 a of the first mold 2 or the eyeball-side surface obtained by the second transfer surface 3 a of the second mold 3, mold-specific marks remain on both the object-side surface and the eyeball-side surface. Therefore, a mold-specific mark for the first mold 2 (first mold-specific mark 51) is engraved into the first transfer surface 2 a of the first mold 2, and a mold-specific mark for the second mold 3 (second mold-specific mark 52) is engraved into the second transfer surface 3 a of the second mold 3. In other words, the technical concept of the present invention may be applied to either the first mold 2 or the second mold 3.

[0087] In order to encompass each of the above examples, the expression "a mold-specific mark that identifies at least one of the first mold 2 and the second mold 3 is engraved into at least one of the first transfer surface 2a and the second transfer surface 3a" is used. However, it is preferable that the predetermined mold-specific mark is provided on a predetermined mold. This ensures a one-to-one correspondence between the mold and the mold-specific mark (and thus the mold-specific information), making the correspondence clear. It is preferable that at least the mold-specific mark for the first mold 2 (first mold-specific mark 51) is engraved into the first transfer surface 2a of the first mold 2. To reiterate, the first mold 2 may be used to form the object-side surface of the spectacle lens, or the eyeball-side surface.

[0088] (Specific Means for Forming Mold-Specific Marks) There are no limitations on the specific means for forming the mold-specific marks. It is sufficient that the mold-specific marks, which are transfer marks formed on the transfer surface of the first or second mold, can be precisely transferred to the lens material and become readable. The means may be etching or mechanical processing, or spraying or adhering a specific material, so long as a three-dimensional, durable three-dimensional pattern is formed.

[0089] However, dry, non-contact engraving using a laser, rather than wet, contact engraving using hydrofluoric acid, is preferable because it eliminates the complexity of wet processing and allows for the formation of fine, precise mold-specific marks.

[0090] On the spectacle lens surface to which the mold-specific mark has been transferred, a convex portion formed by transferring the concave portion of the mold, i.e., a mark composed of convex portions, is formed. Conversely, a mold-specific mark having convex portions may be formed on the mold, and a mold-specific mark having concave portions may be formed on the spectacle lens surface. However, it is more preferable to form convex portions on the spectacle lens by transferring the concave portion of the mold using an advantageous method described below.

[0091] In this specification, "composed of convex portions" refers to a combination of convex portions and non-convex portions (base portions). For example, consider a case where a lens is provided with a two-dimensional code, and multiple cells formed within a 3 mm square are composed of a combination of convex portions and base portions. The dimensions of each convex portion are preferably a square with a side length of 0.3 mm or less. The dimensions of each convex portion are preferably 0.2 mm or less. 0.2 mm is exemplified in the figures of this application. The same numerical specifications apply to cells carved into the mold 2. Furthermore, "composed of carved portions" in the first transfer surface 2a of the first mold 2 refers to a combination of carved portions and non-carved portions (base portions of the first transfer surface 2a), similar to "composed of convex portions." Of course, the size of the cells is not limited to 3 mm square. The content of this paragraph can also be applied to recesses that constitute mold-specific marks.

[0092] As a dry and non-contact type engraving processing means for the mold material, for example, a so-called solid-state laser (YAG, NdYAG, YVO ４ , NdYVO ４ In one embodiment of the present invention, suitable conditions are as follows.

[0093] For example, a pulsed laser may be applied, the pulse width of which may be from femtoseconds to nanoseconds.

[0094] The applicable wavelength of the laser can be 266 nm to 1064 nm, specifically, 266 nm, 355 nm, 532 nm, or 1064 nm.

[0095] The laser output can be set to 1 to 300 W. The energy per pulse can be set to, for example, about 0.5 to 10 mJ.

[0096] The conditions for laser marking when engraving the mold-specific mark are not limited to those described above, and may be set appropriately depending on the type of lens material and the dimensions and depth of the mold-specific mark engraving.

[0097] On the other hand, when carving a mold-specific mark into the mold 2, it is preferable to narrow the laser scanning interval (drawing interval) from the outer edge toward the center of one carved surface (or line width), whether the mold-specific mark is a character string, a combination of rectangular cells and a base portion in a code (two-dimensional code), or a line (one-dimensional code). With this configuration, even if the output is constant, the center of the carved mark, such as a character or a dot, is carved deeper. In other words, it is possible to form the carved mark such that the sides of the carved mark approach each other toward the bottom (for example, tapered sides), as in the preferred example described above. Setting such a scanning interval is possible using a galvanometer scanner in the laser processing device.

[0098] Figure 8 is an explanatory diagram showing the trajectory of the laser scanning line SL when the two-dimensional code of Figure 2 is engraved into the first transfer surface 2a of the first mold 2. The dotted circle indicates the pulse laser diameter P. The arrow indicates the scanning direction of the scanning line SL. Figure 9 is an enlarged photograph showing the two-dimensional code of Figure 4 actually engraved into the first transfer surface 2a of the first mold 2.

[0099] When the mold-specific mark is a two-dimensional code, it is preferable to scan each cell of the two-dimensional code from the outer edge along the rectangle toward the center in a spiral pattern with a laser. In this case, it is preferable to scan the laser toward the center in a spiral pattern while narrowing the spacing between parallel scanning lines SL in one direction. In FIG. 8 , when scanning toward the center in a spiral pattern, it is preferable to narrow the spacing between the scanning lines SL in the left-right direction (X direction) as follows: x1 > x2 > x3 (the spacing between the scanning lines SL on the left side in the figure) and x'1 > x'2 > x'3 (the spacing between the scanning lines SL on the right side in the figure), and to narrow the spacing between the scanning lines SL in the up-down direction (Y direction) as follows: y1 > y2 > y3 (the spacing between the scanning lines SL on the lower side in the figure) and y'1 > y'2 > y'3 (the spacing between the scanning lines SL on the upper side in the figure).

[0100] With this configuration, the central portion of each cell is dug more deeply. In other words, the mold-specific mark is dug into the mold 2 in a quadrangular pyramid shape, and therefore, in the lens obtained from the mold 2, a mold-specific mark consisting of a quadrangular pyramid-shaped convex portion is provided on at least the outermost surface of the lens substrate on at least either the first main surface or the second main surface. Of course, by controlling the laser irradiation of the mold, it is possible to ultimately form convex portions of any desired shape, such as a polygonal pyramid, hemisphere, or mortar shape, on the lens substrate.

[0101] 10 is an image obtained with a 3D shape measuring device (manufactured by ZYGO) of a portion actually carved into a quadrangular pyramid shape on first transfer surface 2a of first mold 2 in a method for manufacturing a spectacle lens that is one embodiment of the present invention. It was confirmed that excellent releasability can be obtained when molding a lens material using a mold with such a recess formed therein.

[0102] In this specification, the term "polygonal pyramid shape (such as a square pyramid)" includes not only a strict polygonal pyramid but also a shape with a rounded or chamfered apex. In this specification, at least in the majority of shapes of the recesses in the mold 2, a recess is considered to be polygonal pyramid shape if the four side surfaces of the recess are concave and approach each other toward the bottom.

[0103] The mold-specific mark is unnecessary information for the end user (e.g., the eyeglass wearer). Therefore, it is preferable that the mold-specific mark be marked on the first transfer surface 2a of the first mold 2 outside the area to be used as the eyeglass lens. This is because the eyeglass wearer will only use the area inside the area to be used as the eyeglass lens, and the area outside this area will be scraped off before the eyeglass wearer receives it. It is sufficient for the mold-specific mark to be visible to the lens manufacturer or eyeglass store before the eyeglass wearer receives it. Therefore, adopting this preferred embodiment does not cause any inconvenience and is actually preferable because it ensures that the wearer's visual field is comfortable.

[0104] Based on the same technical idea as in the above paragraph, it is preferable that the mold-specific mark is formed on the edge of the first transfer surface 2a so that it is marked on the edge of the lens substrate. If it is on the edge of the lens substrate, it will almost certainly be scraped off during edging to process it into a frame shape, and the inconvenience of blocking the wearer's field of vision can be avoided.

[0105] In this specification, the "edge of the lens substrate" refers to an annular portion, for example, within 10 mm (or within 5 mm, or within 3 mm) from the outermost edge toward the center. The "edge of the lens substrate" may also be an area separated from the outer edge of the lens substrate by a distance of 0.5 to 2 mm.

[0106] Similarly, "the vicinity of the outer edge of the mold" refers to an annular portion, for example, within 10 mm (or within 5 mm, or within 3 mm) from the outermost edge toward the center of the transfer surface of the mold. The "vicinity of the outer edge of the mold" may be a region separated from the outer edge of at least one of the first transfer surface and the second transfer surface by a distance of 0.5 to 2 mm.

[0107] It should be noted that the shape of the frame may not be determined at the time of the process of engraving the mold-specific mark. However, in many cases, the vertical dimension of the frame shape is smaller than the horizontal dimension. Therefore, it is desirable to form the mold-specific mark at a position corresponding to the upper or lower end of the uncut lens before edging. This is because it is more likely to be outside the frame than if it were formed at the left or right end.

[0108] Furthermore, with regard to the positions of the mold-specific marks, it is preferable that the first mold-specific marks 51 (arrangement of mold-specific marks on the object-side surface) and the second mold-specific marks 52 (arrangement of mold-specific marks on the eyeball-side surface) do not overlap when the resulting lens is viewed in plan. This eliminates the need to read the first mold-specific marks 51 and then turn the lens over to read the second mold-specific marks 52. In other words, the two mold-specific marks can be read without turning the lens over.

[0109] Furthermore, if the relative positions of first mold specifying mark 51 and second mold specifying mark 52 when the lens is viewed in a plane are determined in advance, it will be easy to determine whether the surface is formed by the upper or lower mold when reading the mold specifying marks from the formed lens material. For example, first mold specifying mark 51 may be carved into first mold 2 and second mold specifying mark 52 may be carved into second mold 3 so that first mold specifying mark 51 is located on the right side and second mold specifying mark 52 is located on the left side when the lens is viewed in a plane (as shown in FIG. 6 ).

[0110] Furthermore, a lens information mark may be engraved into first mold 2 (or second mold 3) so that it is sandwiched between first mold identification mark 51 and second mold identification mark 52 in a plan view of the lens. The lens information mark is a mark for identifying the lens before edging. The content of the lens information mark may be the same as identification number 35A, or may be a simplified version of the content of identification number 35A.

[0111] FIG. 11 is a schematic diagram of a mold-specific mark formed as a linear indentation on the first transfer surface 2a of the first mold 2. FIG. 12 is an explanatory diagram showing the trajectory of the laser scanning line SL when the indentation process of FIG. 11 is performed on the first transfer surface 2a of the first mold 2. In FIG. 12, it is preferable that the spacing between the scanning lines SL in the left-right direction (X direction) narrow toward the center as follows: d1 > d2 > d3 (the spacing between the scanning lines SL on the left side in the figure), and d'1 > d'2 > d'3 (the spacing between the scanning lines SL on the right side in the figure). FIG. 13 is an enlarged photograph showing the indentation of FIG. 11 in the first transfer surface 2a of the first mold 2, where the sides of the indentation are tapered so that they approach each other toward the bottom.

[0112] In addition to the mold-specific marks, a mold 2 may be used in which what is referred to in this specification as a lens characteristic mark (so-called hidden mark) for a lens (especially an eyeglass lens) is engraved. When the hidden mark is engraved and formed, the conditions may be different from those for forming the mold-specific marks. When the hidden mark is engraved and formed, the depth is preferably 0.01 to 0.1 μm.

[0113] The progressive power information marks include alignment reference marks 31 a, 32 a of the progressive power lens and addition power indication marks 31 b, 32 b, which indicate the addition power or its abbreviation. These alignment reference marks 31 a, 32 a and addition power indication marks 31 b, 32 b are required to be displayed on progressive power eyeglass lenses, for example, according to JIS 7315 and the like.

[0114] The identification mark 35 indicating the lens identification information has a horizontally written identification number 35A and a pair of arcuate portions 35B displayed on both sides of the horizontally written identification number 35A. When the identification number 35A and the arcuate portions 35B are combined, they appear to the naked eye as a combination of the letters V and approximately H (for example, V(-)). On the other hand, the identification number 35A, which is the horizontal bar of the (-), may also represent a unique number assigned to each eyeglass lens, which may correspond to the lens identification information.

[0115] By engraving the hidden marks into the mold 2 with a laser, the work can be done in a dry process. This non-contact processing can improve yield and also stably improve the quality of the hidden marks. Furthermore, the safety of the work is improved because chemicals such as hydrofluoric acid are not required, and there is no need to prepare equipment for wet processing, which reduces the number of work steps.

[0116] On the first transfer surface 2a of the first mold 2, the mold-specific mark is marked outside the area to be used as the spectacle lens, while the hidden mark is marked inside that area. That is, the hidden mark formed by the convex portion in the resulting lens substrate remains inside the area to be used as the spectacle lens and on the first main surface of the lens substrate. A low visibility of this hidden mark is preferable in terms of ensuring a comfortable field of vision for the spectacle wearer.

[0117] As mentioned above, the mold-specific mark and the lens characteristic mark (hidden mark) differ in processing depth and position, but when laser processing is applied, it is possible to form them in one device and one process by determining only the respective condition settings in advance, which is extremely advantageous in terms of production efficiency.

[0118] (Curing Step) After the marking step, the lens material is cured between the first mold 2 and the second mold 3. As for the specific technique for the curing step, a curing step in a known technique for manufacturing a lens using the mold 2 may be adopted.

[0119] (Mold Release Step) After the curing step, the lens to which the mold-specific mark has been transferred is released from the first mold 2 and the second mold 3. As for the specific technique for the mold release step, a curing step in a known technique for manufacturing a lens using the mold 2 may be adopted.

[0120] If the first transfer surface 2a of the first mold 2 is provided with an indentation shape in which the sides of the indentation approach each other toward the bottom, the releasability of the lens substrate from the first mold 2 is improved.

[0121] In the manufactured lens, for example, at least the first main surface (the surface on the object side) of the lens substrate is formed with a convex portion corresponding to this concave portion.

[0122] Various films such as a hard coat film, an anti-reflection film, an antifouling film, and a water-repellent film may be formed on the molded lens substrate. Various films may also be formed on the mold-specific mark formed of a convex portion on the object-side surface of the lens substrate. This is because the various films do not significantly reduce the ease of recognition of the mold-specific mark, for example, the ability to read the code using an optical recognition device.

[0123] The coated lens substrate is edged to the shape of the frame. If mold-specific marks are provided on the outside of the frame shape, the outside of the frame shape is scraped off along with the mold-specific marks. The edged eyeglass lens is then fitted into the frame to complete the eyeglasses.

[0124] (Effects of One Aspect of the Present Invention) Some of the effects of one aspect of the present invention described above will be recited below.

[0125] According to one aspect of the present invention, the mold 2 can be identified from the lenses produced using the mold 2.

[0126] An advantage of identifying the mold 2 used is that information about the lens as a product can be fed back to the mold 2. One specific example of this advantage is that, based on a visual inspection of a lens that has a defect caused by the mold 2, the mold 2 that produced the defect can be identified. Another advantage is that, when a lens with an unexpected shape is manufactured, an incorrectly placed mold can be identified from an inspection of the lens shape. When an operator needs to understand the presence, type, location, severity, and other important points to note during the visual inspection of the mold 2, the information about the defect may be linked to the mold identification mark engraved in the mold 2.

[0127] Specifically, the work involves recognizing a two-dimensional code, which is a mold-specific mark engraved into the mold 2, with a reading device that combines an imaging element and an automatic two-dimensional code recognition device, and then inputting information about these defects into a database for the mold 2 using a computer, or tracking the information stored in the database.

[0128] In addition to inputting information about defects, the following specific work contents and effects can be mentioned. That is, when assembling the first mold 2 and the second mold 3, for example, a mold-specific mark (two-dimensional code) engraved on the first transfer surface 2a of the first mold 2 is recognized by a reading device. During this recognition, if there is data in the database indicating that the first mold 2 has already been reported to have a defect multiple times, the first mold 2 is removed from the lens production process (lens production line, manufacturing process, manufacturing line). The first mold 2 is then repaired or rejected. In other words, the defective mold 2 can be removed before the first mold 2 and the second mold 3 are assembled to actually manufacture a lens. This avoids the needless continued production of defective lenses.

[0129] Moreover, this effect is achieved without relying on the operator's eyes. Therefore, the accuracy of determining whether or not there is a defect is high. Visual inspection of glass molds is difficult due to dirt or scratches present on the non-transferred surface. Therefore, complete inspection cannot be expected due to oversights. On the other hand, one aspect of the present invention makes it possible to detect defects using a different approach from conventional methods, by identifying defective molds from transferred lenses.

[0130] Another specific example of the effect brought about by identifying the mold 2 that has been used is that it becomes possible to manage information such as the use history of the mold 2. For example, it becomes possible to manage information such that the use history is accumulated in a database, and molds 2 that have been used more than a certain number of times are removed from the lens production process. Furthermore, it becomes possible to manage information such that, for a mold 2 that has developed a defect that is not serious enough to cause the lens to be discarded, if the occurrence of such a defect is reported multiple times, the mold 2 is repaired or removed.

[0131] (Others) Although the embodiments of the present invention have been described above, the above disclosure shows exemplary embodiments of the present invention. In other words, the technical scope of the present invention is not limited to the above exemplary embodiments, and various modifications are possible without departing from the spirit of the present invention.

[0132] Up to this point, the mold-specifying mark for specifying the mold is marked by engraving the transfer surface by irradiating it with a laser, but the present invention is not limited to this embodiment.

[0133] For example, marking may be performed by forming projections and depressions by dry or wet etching instead of laser irradiation.

[0134] For example, when a mold is formed using a casting mold (e.g., a master) like a lens, if a mold-specific mark is marked on the master by engraving, the mold obtained from the master will automatically have the mold-specific mark marked on it without having to be engraved by laser irradiation. The following expression includes this case: "A mold-specific mark that identifies at least one of the first mold and the second mold is marked as a transfer mark on at least one of the first transfer surface and the second transfer surface." While the examples up to this point have mainly used engraving by laser irradiation, the previous description of "a marking engraved on the first transfer surface by laser irradiation" can be read as "marked on the first transfer surface as a transfer mark."

[0135] The technical concept of the present invention is also reflected in a mold manufacturing method and a mold obtained by the manufacturing method. The mold has the following configuration. "A method for manufacturing a first mold used when manufacturing a lens having a first principal surface and a second principal surface, the method comprising: curing a lens material between a first mold having a first transfer surface from which the shape of the first principal surface is transferred; and a second mold having a second transfer surface from which the shape of the second principal surface is transferred; the method comprising: engraving a first-mold-specifying mark that specifies the first mold by irradiating the first transfer surface with a laser." "A mold used when manufacturing a lens having a first principal surface and a second principal surface, the method comprising: curing a lens material between a first mold having a first transfer surface from which the shape of the first principal surface is transferred; and a second mold having a second transfer surface from which the shape of the second principal surface is transferred; the method comprising: engraving a first-mold-specifying mark that specifies the first mold on the first transfer surface as a transfer mark (preferably engraved by irradiating the transfer surface with a laser)." The specific details of the mold and its manufacturing method are the same as those described above, and therefore will not be described here.

[0136] The technical idea of ​​the present invention is to transfer a mold-specific mark to a lens when manufacturing a lens from a mold 2 on which the mold-specific mark has been marked (preferably engraved) as a transfer mark, thereby providing the lens with the mold-specific mark. Therefore, a mold 2 on which the mold-specific mark has been marked (preferably engraved) as a transfer mark may be prepared in advance, and a lens may be manufactured using the mold 2. In this specification, the term "mold preparation step" includes a case in which a mold 2 on which the mold-specific mark has been marked (preferably engraved) as a transfer mark is prepared in advance, as well as a case in which the person who performs the hardening and demolding of the lens also marks (preferably engraved) the mold-specific mark as a transfer mark.

[0137] In addition to the mold-specific marks and lens characteristic marks (hidden marks), any other information may be marked on the first mold 2. This information may be marked on a surface other than the first transfer surface 2a. For example, the information may be marked on a non-transfer surface of the first mold 2 (the surface or side surface facing the first transfer surface 2a). This marking may be an indentation, may be transferred using the master, or may be marked inside the mold 2. In any case, if it is desired to complete the marking work in one go, it is preferable to use a laser (particularly a pulsed laser) to mark the information at any position on the mold 2, in the same manner as the mold-specific marks and lens characteristic marks (hidden marks).

[0138] The technical concept of the present invention can also be applied to a method for identifying a mold from a lens. A specific configuration thereof is as follows: "A method for identifying a mold used in manufacturing an eyeglass lens having a first main surface and a second main surface by curing a lens material between a first mold 2 having a first transfer surface 2a from which the shape of the first main surface is transferred, and a second mold 3 having a second transfer surface 3a from which the shape of the second main surface is transferred, the method comprising: marking a mold-identifying mark for identifying the first mold 2 on the first transfer surface 2a as a transfer mark (preferably by engraving the transfer surface 2a by irradiating a laser onto the transfer surface 2a); and identifying at least one of the first mold 2 and the second mold 3 from a post-transfer mold-identifying mark (reference symbol 51T) formed by transferring the mold-identifying mark of the first mold 2 to the first main surface of the lens." A preferred specific example is as follows. - Reading the mold-identifying mark transferred onto the first main surface of the lens (for example, by a reading unit described later), referring to a database related to first mold 2 (for example, by a reference unit described later), and identifying first mold 2 (and / or second mold 3) from the mold-identifying information related to first mold 2 (for example, by checking the results displayed on a display unit described later). - Includes a step of acquiring mold-related information recorded in the database in association with the mold-identifying information.

[0139] The technical concept of the present invention can also be applied to a system (or apparatus) that identifies a mold from a lens. In this specification, the term "system" can also be applied to an "apparatus."

[0140] Specific examples and preferred examples of a mold identification system according to one embodiment of the present invention will be described below. Reference unit Display unit Recording unit Control computer unit

[0141] Preferably, the reference unit further includes a first reader that reads the post-transfer mold-specific mark on the first main surface of the lens. The first reader is not limited as long as it is capable of reading the post-transfer mold-specific mark. For example, if the post-transfer mold-specific mark is a two-dimensional code, the first reader may be a two-dimensional code scanner.

[0142] By reading the transferred mold-specific mark with the first reading unit, at least a part of the mold-related database is displayed on the first display unit. The first display unit may be a display screen of a tablet terminal or a monitor screen. If the tablet terminal is equipped with a two-dimensional code scanner, the tablet terminal may serve as both the display unit and the first reading unit.

[0143] It is preferable that the system further includes a recording unit for recording the database. The recording unit may or may not be included in the configuration of the mold identification system (or device). For example, the recording unit may be provided in a factory computer, a control computer, or a server on a network.

[0144] The control computer is a control unit that enables the above-mentioned units to perform their functions. The control computer functions as a computer device that processes information as instructed by a predetermined program, and is specifically configured by a combination of a CPU (Central Processing Unit), HDD (Hard Disk Drive), ROM (Read Only Memory), RAM (Random Access Memory), an external interface (I / F), etc.

[0145] A specific example of "identifying the first mold 2 from the transferred mold-identifying mark (reference symbol 51T) on the lens" is as follows: The transferred mold-identifying mark transferred to the first main surface of the lens is read by a first reading unit, and a database related to the first mold 2 is referenced to identify the first mold 2 (and / or the second mold 3) from the mold-identifying information related to the first mold 2. Furthermore, mold-related information recorded in the database in association with the mold-identifying information is obtained.

[0146] REFERENCE SIGNS LIST 1 Assembled body 2 First mold 2a First transfer surface 3 Second mold 3a Second transfer surface 4 Gasket 10 Cast lens 31a Alignment reference mark 32a Alignment reference mark 31b Addition power indication mark 32b Addition power indication mark 35 Identification mark 35A Identification number 35B Arc portion 51 First mold identification mark (two-dimensional code) 52 Second mold identification mark (two-dimensional code) 60 Lens type mark CA Cavity D Cell (carved into the first transfer surface of the first mold) P Pulse laser diameter SL Scanning line

Claims

1. A method for manufacturing a lens having a first principal surface and a second principal surface by hardening a lens material between a first mold having a first transfer surface from which the shape of the first principal surface is transferred, and a second mold having a second transfer surface from which the shape of the second principal surface is transferred, wherein a mold-identifying mark that identifies at least one of the first mold and the second mold is marked as a transfer mark on at least one of the first transfer surface and the second transfer surface, and the lens to which the mold-identifying mark has been transferred is manufactured by hardening the lens material between the first mold and the second mold.

2. The method for manufacturing a lens according to claim 1, wherein a mold-identifying mark for identifying the first mold is marked on the first transfer surface as a transfer mark.

3. A method for manufacturing a lens as described in claim 1, comprising: a mold preparation step of preparing a mold having the mold-specific mark marked on at least one of the first transfer surface and the second transfer surface; a hardening step of hardening the lens material between the first mold and the second mold after the mold preparation step; and a demolding step of releasing the lens having the mold-specific mark transferred thereto from the first mold and the second mold after the hardening step.

4. A method for manufacturing a lens as described in claim 1, wherein a mold identification mark that identifies at least one of the first mold and the second mold is marked by engraving using laser irradiation into at least one of the first transfer surface and the second transfer surface.

5. The method for manufacturing a lens according to any one of claims 1 to 4, wherein the lens is a lens for glasses.

6. The method for manufacturing a lens according to claim 5, wherein in the eyeglass lens, the first principal surface is the surface facing the object and the second principal surface is the surface facing the eyeball, and a mold-identifying mark identifying the first mold is marked on the first transfer surface.

7. The method for manufacturing a lens according to claim 5, wherein the mold-specific mark is marked outside the area to be used as the lens for the glasses.

8. The method for manufacturing a lens according to claim 5, wherein the mold-specific mark is disposed near the outer edge of at least one of the first transfer surface and the second transfer surface.

9. The lens manufacturing method according to claim 8, wherein the mold-specific mark arranged near the outer edge is arranged at a position where the distance from the outer edge of at least one of the first transfer surface and the second transfer surface is 0.5 to 2 mm.

10. A method for manufacturing a lens as described in claim 5, wherein a hidden mark in the eyeglass lens is marked on at least one of the first transfer surface and the second transfer surface, together with a mold identification mark that identifies at least one of the first mold and the second mold.

11. The method for manufacturing a lens according to any one of claims 1 to 4, wherein the mold-specific mark is an information record that can be read using an optical recognition device.

12. A method for manufacturing a lens according to any one of claims 1 to 4, wherein the mold-specific mark is a two-dimensional code, and the two-dimensional code is formed by forming a plurality of cells constituting the two-dimensional code into recesses in at least one of a polygonal pyramid shape, a hemisphere shape, and a cone shape on at least one of the first transfer surface and the second transfer surface.

13. The method for manufacturing a lens according to claim 12, wherein the two-dimensional code is sized to fit within a square with one side measuring 1 to 10 mm or a rectangle with a shorter side measuring 1 to 10 mm.

14. A method for manufacturing a lens according to any one of claims 1 to 4, wherein a first mold-identifying mark that identifies the first mold is marked on the first transfer surface, and a second mold-identifying mark that identifies the second mold is marked on the second transfer surface, and the mold-identifying marks include the first mold-identifying mark and the second mold-identifying mark.

15. A method for manufacturing a lens according to any one of claims 1 to 4, wherein the marking is formed by a pulse laser having a pulse width of femtosecond to nanosecond, and the wavelength of the applied laser is 266 to 1064 nm.

16. A lens having a first principal surface and a second principal surface and a lens substrate, wherein a mold-specific mark consisting of a convex portion is provided on at least the outermost surface of the lens substrate on at least either side of the first principal surface or the second principal surface.

17. The lens of claim 16, wherein the lens is a lens for spectacles.

18. The lens according to claim 17, wherein the first principal surface is a surface facing the object and the second principal surface is a surface facing the eyeball, and the mold-specific mark is provided on the first principal surface.

19. The lens according to claim 17, wherein the mold-specific mark is marked outside the area to be used as a lens for the eyeglasses.

20. A lens according to any one of claims 16 to 19, wherein the mold-specific mark is an information record that can be read using an optical recognition device.

21. A lens according to any one of claims 16 to 19, wherein the mold-specific mark is a two-dimensional code, and the plurality of cells constituting the two-dimensional code are configured with convex portions having at least one of a polygonal pyramid shape, a hemisphere shape, and a cone shape.

22. A method for manufacturing a first mold used in manufacturing a lens having a first principal surface and a second principal surface, by hardening a lens material between a first mold having a first transfer surface from which the shape of the first principal surface is transferred, and a second mold having a second transfer surface from which the shape of the second principal surface is transferred, the method comprising marking a first mold identifying mark that identifies the first mold on the first transfer surface as a transfer mark.

23. The mold manufacturing method according to claim 22, wherein the marking is a process of engraving a first mold identifying mark that identifies the first mold into the first transfer surface by irradiating it with a laser.

24. A mold used when manufacturing a lens having a first principal surface and a second principal surface, wherein the first mold is used when manufacturing a lens by hardening a lens material between a first mold having a first transfer surface from which the shape of the first principal surface is transferred, and a second mold having a second transfer surface from which the shape of the second principal surface is transferred, wherein a first mold identification mark that identifies the first mold is marked on the first transfer surface as a transfer mark.

25. The mold according to claim 24, wherein the marking is a process of engraving a first mold identifying mark that identifies the first mold by irradiating the first transfer surface with a laser.

26. A method for identifying a mold used in manufacturing an eyeglass lens having a first principal surface and a second principal surface by hardening a lens material between a first mold having a first transfer surface from which the shape of the first principal surface is transferred, and a second mold having a second transfer surface from which the shape of the second principal surface is transferred, the method comprising: a mold identification mark identifying the first mold is marked on the first transfer surface as a transfer mark; and identifying at least one of the first mold and the second mold from a post-transfer mold identification mark formed by transferring the mold identification mark of the first mold to the first principal surface of the lens.

27. An apparatus for identifying a mold used in manufacturing an eyeglass lens having a first principal surface and a second principal surface by hardening a lens material between a first mold having a first transfer surface from which the shape of the first principal surface is transferred, and a second mold having a second transfer surface from which the shape of the second principal surface is transferred, wherein a mold identification mark identifying the first mold is marked on the first transfer surface as a transfer mark, and a post-transfer mold identification mark formed by transferring the mold identification mark of the first mold to the first principal surface of the lens is read by a reading unit, and a database is referenced by a reference unit to identify at least one of the first mold and the second mold.

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