Method and lens holder for coloring spectacle lenses

Abstract

The present invention provides a method for tinting a spectacle lens (60), comprising the steps of selectively performing a surface treatment on a preselected portion (62) of the surface of the spectacle lens and providing a tinting solution (70) to the spectacle lens. Furthermore, a lens holder (10) for tinting a spectacle lens (60) is provided, comprising a reception unit (20) suitable for holding the spectacle lens (60) in a predefined position and a masking unit (30) suitable for masking a portion (63) of the surface of the spectacle lens when held by the reception unit (20) in the predefined position.

Description

Technical Field

[0001] The present invention relates to the coloring of spectacle lenses. Specifically, the present invention relates to a method for coloring a spectacle lens by selectively treating the surface of the spectacle lens, a colored spectacle lens obtained therefrom, and a lens holder used in this method. In addition to this, the present invention is directed to a coloring system having a lens holder, a corresponding computer program, and computer-readable data, and a kit for carrying out the above method.

Background Art

[0002] The coloring of spectacle lenses is required for many reasons including medical and safety reasons. Due to the properties of the surface material itself or the coating applied on the surface, simple surface printing often does not achieve coloring with the required quality, particularly the desired resolution and durability.

[0003] Furthermore, there is also a need to effectively color only selected portions of the surface of a spectacle lens, such as patterns representing marks, numerical values, characters, simple shapes, etc. In the case of sunglasses, lenses colored in a single solid color are most commonly used, but in recent years, coloring with partial coloring or gradients that provide additional advantages has become increasingly important.

[0004] Conventionally, selective coloring of spectacle lenses has been achieved by designing and applying masking means such as adhesive tapes or thin films to cover portions of the lens surface that are not desired to be colored by immersing the lens in a bath containing a dye. However, this method has drawbacks in terms of reproducibility and uniformity.

[0005] Specifically, the conventional method of using an adhesive tape has the drawback of unwanted material infiltration below the masked portion of the lens when the lens is immersed in the coloring bath, especially during coloring on the curved surfaces (both convex and concave) of spectacle lenses. Since the tape is applied manually to the lens, this poor applicability of the conventional method on the curved surface of the spectacle lens can be attributed to the wrinkles formed when applying the tape onto the surface. Furthermore, since the tape, which is mostly flat in shape, has to be applied onto the curved surface of the spectacle lens, wrinkles can easily form at the edges of the tape. Moreover, the larger the portion of the spectacle lens that needs to be masked, the poorer the adhesion between the tape and the spectacle lens. These wrinkles result in water infiltration and thus lead to non-uniform coloring with unclear edges of the pattern or ultimately color stains. Specifically, in the state where the spectacle lens has a large curvature, it was difficult to obtain a desirable coloring with good quality using the conventional method.

[0006] Furthermore, the conventional selective coloring method could provide only limited coloring patterns. For example, the most commonly used method for realizing a coloring pattern is the die-cutting process, according to which a die for cutting an adhesive tape is used on a die press to prepare the tape in a desired form. However, the die-cutting process does not allow the realization of patterns with small sizes or complex patterns, because in the die-cutting or tape application step, small-sized tapes can be easily damaged. In addition to this, small-sized masking tapes may also tend to be prone to coloring infiltration. Furthermore, since the step of applying the die-cut tape to the spectacle lens is performed manually, it is not possible to easily repeat with high precision by using hands to align the tape to a plurality of lenses at exactly the same position. Therefore, it is difficult to realize a tape having a shape not connected to the lens edge (side). Therefore, the conventional method is inefficient and, in some cases, not suitable for selectively coloring complex and / or small patterns on the spectacle lens. U.S. Patent No. 4,991,849, which targets the incorporation of slits into golf glasses, mentions masking the slit portion during the shading of the golf glasses, but this also has the same problem as described above. Furthermore, it does not provide any specific masking method.

[0007] Finally, tape coloring, in most cases, first requires the preparation of a metal mold for the realization by means of individual tapes applied on each spectacle lens and the subsequent die-cut tapes. Also, since as many tapes as the number of spectacle lenses to be colored are required, this is a cumbersome process and requires a high degree of manual labor and the skill of the operator in aligning the tapes to the lenses. Furthermore, the adhesive tapes have to be discarded after use. Moreover, when manufacturing a single or only a few prototypes of colored lenses at the initial stage of lens development, it is also necessary to pre-manufacture the metal mold, which involves associated costs and time.

[0008] To improve the coloring of ophthalmic lenses, U.S. Patent No. 9,677,222 B2 discloses a method of selectively coloring a lens substrate between different portions of the lens substrate surface by using two different surface materials. Here, a substrate having a first surface portion formed by a first material and a second surface portion formed by a second material is used, where the first material and the second material are different. The dye source penetrates only into the first surface portion having the first material by heating, but does not penetrate into the second surface having the second material. A difference between the freezing or softening temperatures of the materials is used for this. However, since a further step of applying a film to individual spectacle lenses having different surfaces and a delicate adjustment of the heating temperature are required, there is still a need to improve the coloring process. Furthermore, due to an insufficient difference between the properties of the two surface materials associated with the film application process, it may not be easy to obtain high-quality coloring in some cases.

[0009] There is also a method of applying an ink receptor layer on a lens substrate in the form of a thin film. Japanese Patent No. 3075403 describes a method of manufacturing a colored plastic lens by using an inkjet printer, heat treatment, and finally removal by rinsing, and finally applying a water-soluble polymer coating to apply a cured coating on an eyeglass lens and an aqueous ink solution containing a disperse dye on the cured coating. International Publication No. 2006 / 079564A1 pamphlet discloses coating a substrate of an optical lens with a layer of an ink receptor material having the ability to form a porous ink receptor film, evaporating the solvent present in the ink receptor material to form a porous film, applying an ink solution using an inkjet device on the porous film in a state where the ink solution is absorbed in the film, heating the optical lens until the substrate achieves the desired coloring, and then removing the ink receptor film, proposing a simplified process. Therefore, in the case of these methods, there is a need to apply an auxiliary layer on the lens substrate. In particular, it is difficult to obtain a clear coating and a thin film coating without haze, and the application and conformity of the auxiliary layer can have an adverse effect on the lens properties. Furthermore, the additional process steps required in this regard can also be cumbersome and inefficient.

[0010] European Patent Application Publication No. 3266598 A1 is considered to be the closest prior art and discloses a process for the manufacture of optical eye glasses. In a first step, an area of the optical eye glass is being processed by a laser beam in order to remove a surface coating within a non-treated zone. The movement of the laser beam can be programmed in order to generate a pattern or an element of a pattern that is drawn on the eye glass. Subsequently, in order to form a pattern having ink, the ink is being deposited within the non-treated zone, for example by inkjet printing. By this process, a surface coating that prevents the adhesion of the ink is locally removed in order to reach a layer of the ophthalmic lens that has properties allowing the retention of the ink. Unfortunately, this method is applied to optical eye glasses having further coatings, requires laser beam processing and is prone to damage due to insufficient adhesion of the ink. SUMMARY OF THE INVENTION PROBLEM TO BE SOLVED BY THE INVENTION

[0011] Accordingly, there is a need for a new alternative coloring method that can provide a desirable colored pattern in an industrially effective and simple manner and with high quality.

[0012] It is an object of the present invention to provide an improved method for selectively coloring spectacle lenses, an improved colored lens obtainable by the method, an improved lens holder, and an improved coloring device. In addition thereto, a lens holder, a corresponding computer program, a coloring system having computer data, and a kit for carrying out the method may also be provided.

[0013] The inventors have recognized the need for relatively sophisticated and high-quality coloring in a relatively easily applicable and reproducible manner. Thus, on the one hand, in comparison with the adhesive tape coloring method, the present invention provides spectacle lenses having high-quality coloring with cost efficiency and flexibility, and on the other hand, in comparison with methods using auxiliary thin film layers for coloring or further processing, the present invention enables coloring in an easily applicable and reproducible manner with high-quality coloring without degrading the lens properties.

Means for Solving the Problems

[0014] For several years, plasma processing has been used for various applications such as surface treatment, oxidation, polymer etching, and the like. Plasma processing can induce different effects depending on the type of the subject material, plasma conditions, or the type of plasma used. For example, Chinese Patent No. CN105204180 applies plasma processing to spectacle lenses to deposit a plasma layer on the surface of the spectacle lenses, but nevertheless, does not provide any practical use of the method.

[0015] Based on the concept of using plasma processing to color spectacle lenses by intentionally adjusting the surface properties of the spectacle lenses, the inventors have arrived at the present invention that can address the drawbacks of the prior art.

[0016] According to a first aspect of the present invention, there is provided a method for selectively coloring a spectacle lens. The method includes (i) a step of selectively plasma-processing a preselected portion of the surface of the spectacle lens, and (ii) a step of applying a coloring solution to at least a portion of the surface of the spectacle lens that has not been processed by the plasma.

[0017] According to a second aspect of the present invention, there is provided a lens holder suitable for coloring spectacle lenses, which has a reception unit suitable for holding spectacle lenses at a predefined position and a masking unit suitable for masking a part of the surface of a spectacle lens when held by the reception unit at a predefined position.

[0018] A third aspect of the present invention is the use of a lens holder according to the second aspect for selectively coloring a spectacle lens suitable for covering a part of the surface of a spectacle lens held by the lens holder during plasma treatment.

[0019] According to a fourth aspect, there is provided a coloring system or apparatus, in which case the system or apparatus has a lens holder according to the second aspect, an apparatus for plasma treatment, and a coloring tank having a coloring solution.

[0020] The fifth and sixth aspects of the present invention provide a computer program having instructions that cause a computer to execute the steps of the method according to the first aspect of the present invention when the program is executed by the computer, and a computer-readable data carrier or data signal having instructions that cause a computer to execute the method according to the first aspect of the present invention when executed by the computer. Specifically, the computer program can be stored on a non-transitory computer-readable data carrier. Therefore, any of the above-described method steps can preferably be executed by using a computer program or by using a computer or a computer network. Specifically, the computer program can send instructions to a device suitable for processing plasma, such as a plasma processing apparatus, and the device is correspondingly executing plasma processing. For example, the device can be programmed to perform plasma processing on a preselected portion of the spectacle lens. Furthermore, the computer program can send instructions to a device suitable for providing a coloring solution, such as a coloring tank or a coloring chamber, and the device is applying the coloring solution onto the spectacle lens according to the instructions.

[0021] Furthermore, the seventh aspect of the present invention provides a kit having a lens holder according to the second aspect of the present invention and instructions for use of the lens holder according to the method of the first aspect of the present invention.

[0022] The basic concept of the present invention is to color spectacle lenses having a surface by selectively plasma-treating a preselected portion of the surface of the spectacle lenses such that the surface of the spectacle lenses that has not experienced plasma treatment is colored while a preselected portion that has been exposed to plasma treatment is not colored in a subsequent coloring step. The inventors have found that plasma treatment changes the surface properties of spectacle lenses. By plasma treatment, the exposed surface of the spectacle lenses is changed in such a way that coloring thereon by a coloring solution is prevented, thereby providing a highly selective application of the coloring solution to the surface of the spectacle lenses that has not been treated by plasma while changing only a very thin region of a preselected surface of the spectacle lenses so that the surface properties required for the spectacle lenses are not substantially changed or damaged.

[0023] Throughout this specification, the following definitions apply.

[0024] A spectacle lens is an ophthalmic lens that is worn in front of the eye without contact with the eye (DIN ISO 13666:2019, section 3.5.2), in which case the ophthalmic lens is a lens intended to be used for the purpose of measuring, correcting, and / or protecting the eye, or for changing its appearance (DIN ISO 13666:2019, section 3.5.1). Non-limiting examples of spectacle lenses include not only single-focus or multi-focus lenses, which may or may not be segmented, but also corrective or non-corrective spectacle lenses, magnifying lenses, and protective lenses that include other elements used to correct, protect, or improve eyesight, or visors such as those found in glasses, goggles, and helmets. In particular, a spectacle lens is a lens designed to fit into a spectacle frame so as to protect the eye and / or correct eyesight, and can be a non-corrective or corrective ophthalmic lens (also referred to as a plano or afocal lens, such as for sunglasses, sports-specific eye glasses, or those for filtering specific wavelengths). The corrective lens may be a single-focus, bifocal, trifocal, or progressive multifocal lens. Thus, generally, in the context of the present invention, the term "lens" or "lenses" means any of the above-described spectacle lenses.

[0025] The eyeglass lens of the present invention is preferably an "eyeglass lens substrate". The term "eyeglass lens substrate" means a piece of optical material used in the manufacturing process of an eyeglass lens, i.e., a precursor of a finished eyeglass lens. A suitable precursor of a finished eyeglass lens is, for example, a lens blank in a semi-finished state, in which case the term "lens blank in a semi-finished state" means a piece of optical material having one optically finished surface for manufacturing an eyeglass lens (DIN ISO 13666:2019, Section 3.8.1). In any case, the eyeglass lens substrate used herein has at least one surface without any coatings such as AR (anti-reflection) or HC (hard coat) coatings used in the methods described herein.

[0026] The term "lens material" means the material used to manufacture eyeglasses. The eyeglass lens may have a lens material or may be composed of a lens material. The term "surface" or "eyeglass lens surface" means any layer of a three-dimensional eyeglass lens in direct contact with the environment. The surface can be regarded as its boundary. The surfaces of the eyeglass lens substrate include its front surface, i.e., the front face, side surfaces, i.e., the edges, and the rear surface, i.e., the back face.

[0027] The term "masking" means covering a part of the surface of an eyeglass lens and, as a result, protecting the masked part of the surface of the eyeglass lens from contact with other substances or the application of treatment.

[0028] The term "demasking" means removing or eliminating a cover or substance from the surface of an eyeglass lens, thereby enabling the previously masked part to regain exposure to other substances or treatments.

[0029] The term "cover" means placing or arranging something on, above, or around the subject to protect the subject.

[0030] The term "preselected portion" refers to a portion of the surface of the spectacle lens that has been determined not to be colored. The selection is made before applying the present method. There may be at least one preselected portion in the present method.

[0031] The term "portion (of the surface of the spectacle lens)" means a part or division of the whole (the surface of the spectacle lens) that is individual or distinct. The term "at least a portion (with respect to)" may refer to a part or division of the whole and / or the whole.

[0032] The term "coloring" means the process of providing coloration to the surface of the spectacle lens. A colored spectacle lens is, for example, a spectacle lens in which at least a part of the electromagnetic spectrum, such as the light spectrum (380 - 780 nm) perceptible to humans, and / or other spectral ranges such as NIR (780 - 3000 nm), UV - A (315 - 380 nm), and UV - B (280 - 315 nm), is attenuated not by the polymer lens material itself but due to the addition of further substances. The amount of attenuation may be, for example, 6 - 99%. In the case of attenuation within the light spectrum perceptible to humans, this may result in a visual transmittance as defined in DIN EN ISO 8930 - 3:2013, such as 1 - 94% within the colored lens area. The visual transmittance may be further affected by subsequent application of coatings such as AR or HC coatings. Conventionally, coloring can be obtained by immersing or dipping the substrate in a coloring bath, i.e., a liquid dye solution. The colored substance may exhibit uniform coloring, i.e., the colored area shows the same degree of transmittance throughout the entire colored area, or the colored substrate may show a color gradient, i.e., a change in the degree of progressive transmittance within the colored area.

[0033] The term "coloring solution" is to be understood as a liquid having a coloration configured to color spectacle lenses. The coloring solution may have a dye which is a colored substance used to cause the lens to appear in a specific coloration or to change the coloration of the spectacle lens, and may optionally have a swelling agent, a relaxation solution, a surfactant, and / or a buffer. The coloring solution can be converted into a coloring vapor if necessary. The term "aqueous coloring solution" is a coloring solution in which the main solvent is water.

[0034] The term "selective coloring" means that the coloring is present only in specific desired portions of the surface of the spectacle lens, thereby showing colored and uncolored surfaces, for example, in the form of a pattern. In a similar context, the terms "selectively plasma-treat" or "selective plasma treatment" mean that the plasma treatment is applied only to specific desired (preselected) portions of the surface of the spectacle lens and the remaining portions of the surface are not treated by the plasma.

[0035] The term "pattern" means any macroscopic element. For example, selectively (locally) colored portions of the spectacle lens, marks on the spectacle lens, gradients, numerical values, graphic characters of any type, dots, symbols, etc., such graphic representations can be regarded as patterns.

[0036] The term "gradient" is specifically used to describe the intensity distribution of the coloring of the lens across the surface of the spectacle lens. Specifically, the term "gradient coloring" is used to describe the shading of the lens in a direction parallel to the surface of the spectacle lens, more specifically the gradually changing intensity of the coloring on the lens, in a state where the intensity increases in a first direction and decreases in the opposite direction. The term "boundary line gradient coloring" is used to describe the gradient coloring at the boundary line between the colored and uncolored surfaces of the spectacle lens.

[0037] The term "plasma" is a class of particles that includes equal numbers of positive ions and electrons, free radicals, and natural species generated by exciting a gas in an electromagnetic or electric field. This is a state of matter in which the ionized substance has a high degree of conductivity up to the point where long-range electric and magnetic fields govern its behavior. Plasma contains a large portion of charged particles, namely ions and / or electrons. Plasma can be artificially generated by heating a neutral gas or by applying a strong electromagnetic field to it. The terms "plasma treatment" or "plasma treatment step" mean treating a subject in a plasma state using a plasma generation method. Artificial plasma can be generated by applying an electric and / or magnetic field through a gas. For example, the generation method can be, without limitation, low-pressure discharges such as glow discharge plasma, capacitively coupled plasma (CCP), cascade arc plasma source, inductively coupled plasma (ICP), wave-heated plasma, or atmospheric pressure ones such as arc discharge, corona discharge, dielectric barrier discharge (DBD), capacitive discharge, atmospheric pressure glow discharge (APGD), piezoelectric direct discharge plasma, or in some cases ion guns (oxygen, argon, etc.).

[0038] The term "reception unit" defines a part of a lens holder specifically configured to receive and hold one or more lenses. The reception unit is configured to hold the spectacle lens at a predefined position in order to achieve a desired coloring pattern at a desired portion of the surface of the spectacle lens. The reception unit can have a subunit configured to be mounted on at least a portion of the surface of the spectacle lens. This can be, for example, "annular mounting means", which is an annular-shaped subunit configured to be mounted around the upper and optionally outer (edge) periphery of the lens, adapted to the individual shape and surface profile (bend) of the lens to be colored. The annular mounting substantially matches the periphery of the spectacle lens. The reception unit can have means for holding the lens at a predefined position, preferably at least two means for holding the lens. However, any other structure suitable for receiving and holding the lens can be defined as the reception unit. The term "means for holding the lens" or "holding means" means any subunit that can hold the lens during plasma treatment designed to fit the side (edge shape, thickness) profile of the lens, such as a snap-fit connection.

[0039] The term "masking means" is a structure that masks or covers at least a portion of the lens surface. Any structure that masks or covers a portion of the spectacle lens surface and is suitable for protecting a portion of the spectacle lens surface during plasma treatment can be defined as masking means. For example, the masking means can be any type of tape (e.g., adhesive tape) that can be disposed on and cover the surface of the spectacle lens, any material suitable for covering the surface of the spectacle lens (e.g., masking agent, die-cast cover, or 3D printed cover, etc.). Incidentally, the term "masking unit" in the present invention is specifically used to denote one of the components of the lens holder according to the second aspect of the present invention. The masking unit is a component of the lens holder and masks the surface of the spectacle lens during plasma treatment.

[0040] The term "opening" in the present invention refers to an opening (i.e., a hole or aperture), and as a result, notifies a portion of the masking means or masking unit where the portion of the spectacle lens surface corresponding to the position of the opening of the lens holder is not covered and protected. The shape of the opening is not limited and can be selected in consideration of the desired coloring pattern.

[0041] The term "space protrusion" is a hollow portion of the masking unit of the lens holder that extends above the average surface of the masking unit, thereby forming a spatial gap therebetween.

[0042] As used in this specification and the appended claims, the articles "a", "an", and "the" include plural referents unless expressly and unambiguously limited to one referent.

[0043] A method of coloring a spectacle lens having a surface according to a first aspect of the present invention comprises: (i) selectively plasma-treating a preselected portion of the surface of the spectacle lens; and (ii) providing a coloring solution on at least a portion of the surface of the spectacle lens that has not been treated by the plasma.

[0044] In the step of selectively plasma-treating a preselected portion of the surface of the spectacle lens, the plasma is applied only to the preselected portion. The preselected portion of the surface of the spectacle lens treated by the plasma will not be colored in the subsequent coloring step, while the remaining portion of the surface of the spectacle lens not treated by the plasma (i.e., the surface other than the one or more preselected portions) will be colored. The preselected portion will be determined according to the desired coloring pattern, taking into account that the preselected portion will not be colored and that the remaining portion of the surface of the spectacle lens will be colored.

[0045] The plasma treatment can be carried out on the surface of a spectacle lens having a surface without any coating such as an AR (anti-reflection) or HC (hard coat) coating, specifically on the front, side, and / or rear surface. In this case, the spectacle lens is preferably a spectacle lens substrate. That is, the plasma treatment is carried out on the surface of a spectacle lens that does not have any additional lens coating or lens layer that makes the required and prior art processes (e.g., laser beam treatment) inefficient. The reduction in the number of coating layers reduces the investment in the coating device at the initial stage. Also, this improves the durability of the lens due to not only the reduction of the interface but also the adhesion of the entire coating laminate.

[0046] The plasma treatment is carried out on the spectacle lens or on the surface of the spectacle lens, preferably perpendicularly to the center of the surface of the spectacle lens.

[0047] In the present invention, since the plasma treatment step that results in distinct properties between a preselected portion of the surface treated by plasma and a portion of the surface not treated by plasma is completed before providing the coloring solution to the spectacle lens, there is no drawback of liquid infiltration caused by poor adhesion of the masking means resulting from the coloring solution penetrating beneath the masking means that causes non-uniform coloring. Further, since the selective coloring is achieved by the different properties of the individual portions of the surface of the spectacle lens, the coloring quality produced in the coloring step is less affected by the masking itself (rather, it is affected by the plasma treatment state) in comparison with the prior art where the coloring quality depends on the adhesion or quality of the masking means.

[0048] In one embodiment, the step of selectively plasma-treating a preselected portion of the surface of the spectacle lens includes a step of masking a portion of the surface of the spectacle lens other than the preselected portion before the plasma treatment, and a step of demasking the masked portion of the surface of the spectacle lens after the plasma treatment and before providing the coloring solution to the spectacle lens. That is, the selective plasma treatment for the preselected portion is realized by masking a portion of the surface of the spectacle lens except for the preselected portion so that the masked portion is protected during the plasma treatment. The demasking step will occur after the plasma treatment and before providing the coloring solution to the spectacle lens.

[0049] In a further embodiment, masking means can be used for masking. The masking means can be any structure suitable for covering a portion of the surface of the spectacle lens during plasma treatment and protecting it from the plasma treatment. For example, the masking means can be any type of tape (e.g., adhesive tape) that can be placed on and cover the lens surface and any material suitable for covering the lens surface (e.g., a masking agent, a die-cast cover, or a 3D printed cover, etc.). In this embodiment, the masking means is placed on one or more portions of the surface of the spectacle lens other than a preselected portion of the surface of the spectacle lens in the plasma treatment step. The masking means is removed in the demasking step, and then the coloring solution is provided to the spectacle lens.

[0050] In an exemplary embodiment, the masking means may be a lens holder according to a second aspect of the present invention, which has a reception unit and a masking unit.

[0051] In this regard, the present invention is completely different from the conventional coloring or masking method using an adhesive tape or a masking agent in that the masking tape or the masking agent is adhered to the lens in the coloring step and is in contact with the coloring solution. Furthermore, it is also different from the laser beam treatment of European Patent Application Publication No. 3266598A1 in that the uncolored portion is exposed and the colored portion is covered.

[0052] A spectacle lens having any conventional and known material can be used for the present method. In a preferred embodiment, the spectacle lens has a polymeric lens material. The polymeric lens materials that can be used in the context of the present invention are those conventionally used in optics and ophthalmology. Suitable lens materials are, for example, of the types polyamide, polycarbonate, polyimide, polysulfone, poly(ethylene terephthalate) and copolymers of polycarbonate, polyolefin, polyurethane, and polythiourethane. Specific examples of particularly suitable lens materials are polycarbonate or polyamide. When exposed to plasma treatment, the polymer experiences the formation of cross-links of the polymer chains on the surface of the spectacle lens, thereby providing prevention of coloring by the coloring solution at a later stage. Megalenses having polyamide or polycarbonate as the lens material have been found to show the greatest distinction in this regard between plasma-treated and untreated surfaces.

[0053] Plasma treatment is selectively performed on a preselected portion of the surface of the spectacle lens in order to prevent coloring in the preselected portion. In one embodiment, the spectacle lens masked by masking means or a lens holder is being treated by plasma. Plasma treatment of the material surface is a well-developed technique for generating controlled surface modification (Zhou et al., Investigation of surface properties of plasma-modified polyamide 6 and polyamide 6 / layered silicate nanocomposites, J Mater Sci (2011) 46:3084-3093; Poncin-Epaillard, Illustration of surface crosslinking of different polymers treated in argon plasma, Macromol. Chem. Phys. 198, 2439-2456 (1997)). The presence of species such as positive ions, electrons, free radicals, and neutrals in the plasma induces changes in the surface properties within the subject material. In particular, in polymers, it is known that plasma induces the formation of free radicals within the polymer chains and, thus, functions to activate the polymer surface, for example, by crosslinking, etching, activation, etc. The type of reaction occurring on the surface can depend on the plasma state, the subject material, the plasma source, etc. In a preferred embodiment of the method, for a subsequent step of providing a coloring solution, the intensity of the treatment plasma needs to be sufficient to induce a change in the surface properties of the exposed (preselected) portion of the surface of the spectacle lens. For example, in the case of a polymer spectacle lens, the plasma induces crosslinking on the surface, thereby causing physical tightening of the exposed lens surface, which can prevent the coloring solution from entering the exposed (preselected) portion of the surface of the spectacle lens and can result in the preselected portion not being colored.Crosslinking on a preselected portion of the surface of the polymer spectacle lens treated by plasma will prevent the preselected portion from being colored in a subsequent coloring step.

[0054] In order to allow for separate coloring patterns and selective coloring with high quality, the plasma state needs to be appropriately selected. Since different materials with different properties can be combined within the scope of the present invention, it is not possible to indicate specific conditions applicable to all possible lens materials and all possible apparatuses for plasma generation. However, those skilled in the art will be able to determine an appropriate set of plasma conditions by considering the following limitations.

[0055] In this regard, it is preferred that the direct current of the plasma can be 50 - 1,000 mA, more preferably 50 - 500 mA, and most preferably 100 - 300 mA. Further, in a preferred embodiment, the voltage of the direct current can be 100 V - 10,000 V, more preferably 100 V - 1,000 V. In another embodiment, the pressure during plasma treatment can be 0.001 Pa - 100 Pa, preferably 0.001 Pa - 50 Pa, and more preferably 0.001 Pa - 10 Pa. The pressure during plasma can vary depending on the type of plasma generation apparatus and / or the direct current or voltage of the plasma. A plasma state weaker than these ranges will not be able to achieve a change in surface properties that prevents coloring on the preselected portion and thus allows for selective and separate coloring. On the other hand, an overly strong plasma state can result in damage or deterioration of the lens properties of the preselected portion.

[0056] The duration of the plasma treatment is preferably about 10 minutes or less, more preferably 10 seconds to 5 minutes, because relatively long exposure to the plasma can result in relatively poor properties of the lens. However, the duration can vary depending on the type and / or intensity of the plasma applied (e.g., plasma current and plasma voltage). The plasma treatment can be carried out by any conventionally used industrial means for generating plasma as long as the means can provide the above conditions.

[0057] Particularly suitable plasma generation means can be those using gas discharge without limitation. Preferably, the gas can be at least one selected from the group consisting of oxygen (O), nitrogen (N), argon (Ar), carbon dioxide (CO2), helium (He), xenon (Xe), and air, preferably oxygen (O), argon (Ar), and air. Specifically, although not limited thereto, in one embodiment, a glow discharge plasma, which is a plasma formed by passing an electric current through a gas, can be used. In another embodiment, a relatively compact ion gun plasma can also be used.

[0058] After the plasma treatment, a coloring solution is provided on at least the surface of the spectacle lens that has not been treated by the plasma. In one embodiment, the coloring solution can be provided on the entire surface of the lens, for example, by immersing the lens in a coloring tank having the coloring solution throughout. This is possible because the properties of the pre-selected portions of the surface of the lens selectively treated by the plasma in the previous step are changed such that the coloring solution can no longer be applied. In another embodiment, the coloring solution can be provided in such a way that a coloring gradient is obtained, for example, by immersing the spectacle lens in the coloring tank and gradually removing it from the tank so that the darker the portion of the lens is exposed to the coloring for a longer period.

[0059] Any coloring solution suitable for coloring spectacle lenses can be used. For example, it is possible to use the coloring solutions disclosed in U.S. Patent Application Publication No. 20070294841, European Patent No. 2966484B1, or U.S. Patent No. 5453100A, the contents of which are incorporated herein by reference. In one embodiment, the coloring solution can be converted into a coloring vapor. The coloring solution provides selective coloring on a portion of the surface of the spectacle lens that has not been treated by plasma due to selective plasma treatment or masking. The coloring solution cannot color a preselected portion of the exposed and plasma-treated surface of the spectacle lens. In the case of spectacle lenses having a polymeric lens material, this is due to crosslinking on the surface of the polymeric spectacle lens brought about by plasma treatment.

[0060] In a preferred embodiment, the coloring solution is an aqueous coloring solution. The aqueous coloring solution has been found to provide a relatively effective and distinct selective coloring pattern on the surface of the spectacle lens due to its relatively high reactivity with respect to the portions of the surface that have not been treated by plasma as compared to the preselected portions of the plasma-treated surface. In a relatively preferred embodiment, the aqueous coloring solution can be used to color polymeric spectacle lenses.

[0061] Furthermore, the coloring solution has at least one dye. The dye needs to be suitable for coloring the spectacle lens.

[0062] The coloring solution can further have a swelling agent (also referred to as an impregnating solvent). Generally, the swelling agent allows the dye to enter the surface of the eyeglass lens to facilitate the dyeing process. However, after the plasma treatment, the surface of the eyeglass lens has experienced a change in properties and has inactivated the swelling agent. The swelling agent of the present invention functions selectively with respect to the portion of the surface of the eyeglass lens that has not been treated by plasma. By impregnating it, it does not function in a preselected portion of the surface of the eyeglass lens that has been selectively plasma-treated. Thus, the swelling agent has consequently further brought about relatively distinct coloring on the portion of the surface of the eyeglass lens that has not been treated by plasma. The swelling agent selected can depend in part on the type of lens material. Exemplary swelling agents include glycol ethers such as dipropylene glycol monomethyl ether (DPM), tripropylene glycol monomethyl ether (TPM), and propylene glycol monomethyl ether (PM), alcohols such as glycols, aromatic alcohols, non-aromatic alcohols, and / or aromatic compounds such as xylene, toluene, benzene, etc. Alcohols, and more preferably aromatic alcohols such as o-phenylphenol and benzyl alcohol, as swelling agents, have been found to provide the most selective coloring after plasma treatment. The effect is even more pronounced when these types of swelling agents are used in an aqueous coloring solution for coloring polymer eyeglass lenses.

[0063] In another embodiment, the coloring solution can further have a relaxation solvent. As the swelling agent attacks the surface of the eyeglass lens and enables the impregnation of the dye, the relaxation solvent is blended with the swelling agent and functions as a diluent and a wetting agent, and reduces the aggressiveness of the swelling agent. The relaxation solvent can be, for example, propylene glycol (PG), 1,4-butanediol, or ethylene glycol monobutyl ether (EB).

[0064] The molar ratio between the dye and the swelling agent is not limited, but preferably can vary from 0.01 mol% to 5.00 mol%, preferably from 0.05 mol% to 2.00 mol%.

[0065] In a further embodiment, the coloring solution can further have a surfactant and / or a buffer to promote the mixing of the solution and to further improve the impregnation of the dye into the surface of the spectacle lens. The surfactant is not limited, but can have at least one selected from the group consisting of linear alkylbenzene sulfonate, lignin sulfonate, fatty alcohol ethoxylate, and alkaline phenol ethoxylate. The buffer can be used to reduce the aggressiveness of the coloring solution or to adjust the pH. An example of the buffer can have at least one selected from the group consisting of citric acid and acetic acid.

[0066] According to this method, the coloring solution and the pattern can be directly applied onto the surface of the spectacle lens. An auxiliary layer such as an undercoat is not required. Therefore, the method is easily applicable and is excellent in cost efficiency for implementation.

[0067] The method of the present invention can further have a step of removing the coloring solution from the surface of the spectacle lens. Thereafter, the method of the present invention can further have a coating step such as, for example, an AR or HC coating, a mirror coating, a photochromic coating, a polarizing coating, a topcoat coating, and the like.

[0068] The lens holder according to the second aspect of the present invention aims to protect a part of the surface of the spectacle lens from plasma treatment. The lens holder has a reception unit suitable for holding the spectacle lens at a predefined position, and a masking unit suitable for masking a part of the surface of the spectacle lens when held by the reception unit at the predefined position. The lens holder can be in any form as long as it can provide the required functions and can be manufactured using any conventional method.

[0069] In a preferred embodiment, the lens holder can be manufactured by additive manufacturing (AM), also referred to as 3D printing. This provides high flexibility in designing the lens holder without any limitations, and this results in a high flexibility of the coloring pattern.

[0070] 3D printing is the construction of three-dimensional objects from a CAD (computer-aided design) model or digital 3D model in layers stacked on top of each other in an exact geometric shape. This manufacturing process is implemented directly based on the data model in the computer from amorphous materials (such as liquids, powders, and the like) or neutral-shaped materials (band shape, wire shape) using chemical and / or physical processes. These are basic shaping methods, but special tools (such as molds) that preserve the individual shape of the workpiece are not required for a specific product. For the relevant state-of-the-art at present, it is reported by the VDI Statusreport AM 2014. For an overview of the current 3D printing methods, it is provided by 3druck.com / grundkurs-3d-drucker / teil-2-uebersicht-der-aktuellen-3d-druckverfahren-462146 / , last accessed on February 15, 2022.

[0071] Methods of multi-jet modeling, multi-jet fusion, or polyjet printing have been found to be particularly suitable. This method is described, for example, at the URLs de.wikipedia.org / wiki / Multi_Jet_Modeling, https: / / www.materialise.com / en / manufacturing / 3d-printing-technology / multi-jet-fusion, www.materialise.com / de / manufacturing / 3d-druck-technologien / polyjet, or www.stratasys.com / polyjet-technology, each searched on February 15, 2022. Alternatively, instead of this, stereolithography (SLA, see https: / / en.wikipedia.org / wiki / Stereolithography), selective laser sintering (SLS, see https: / / en.wikipedia.org / wiki / Selective_laser_sintering), selective laser melting (SLM, https: / / en.wikipedia.org / wiki / Selective_laser_melting), or fused deposition modeling (FDM, https: / / de.wikipedia.org / wiki / Fused_Deposition_Modeling) can also be used. In a preferred embodiment, the 3D printing method can be multi-jet fusion, which does not require a laser and thus provides a relatively high throughput and very good surface quality.

[0072] Applying 3D printing in the production of lens holders provides increased flexibility for designing and testing lens holders. Any colored pattern, including very complex and / or small patterns, can be realized without any technical difficulties.

[0073] All printable plastic materials can be used for the lens holder. Metals are generally avoided in order to reduce possible scratches on the lens. Plastic materials are particularly preferred since the lens holder is provided on the spectacle lens without additional coatings such as AR (anti-reflection) or HC (hard coat) coatings. More specifically, plastic materials that can be printed from powder using multi-jet fusion are preferred due to their low cost, relatively high printing throughput, and lack of need for support parts. In a preferred embodiment, the material of the lens holder can be, but is not limited to, polyimide or polyurethane due to its good thermal and mechanical resistance, low cost, and compatibility with multi-jet fusion.

[0074] Due to its excellent durability, the lens holder of the present invention can be used multiple times on multiple lenses and is reusable, unlike the adhesive tape used for tape coloring. This means that the lens holder can experience multiple cycles of plasma treatment after being removed from a spectacle lens that has already experienced plasma treatment. Thus, in cases of tape coloring where a corresponding number of masks have to be manufactured and even in cases with laser beam treatment that requires each and every lens to be processed by a laser beam for a desired pattern, the need to manufacture the same number of lens holders as the number of lenses to be colored will no longer exist. According to this lens holder, the present invention can provide cost-effective, environmental, and efficient coloring.

[0075] The reception unit of the lens holder is suitable for holding the spectacle lens at a predefined position such that a desired pattern can be obtained at a desired location (the part corresponding to the position of the masking unit) of the spectacle lens.

[0076] In an exemplary embodiment, the reception unit and the masking unit of the lens holder are connected to each other. By being connected to each other, the reception unit and the masking unit form the lens holder as a single unit. As will be described later, this can be implemented by a connection unit or a continuous surface between the masking unit and the reception unit.

[0077] In another exemplary embodiment, the reception unit can have a subunit configured to be mounted on at least a portion of the surface of the spectacle lens. In a further embodiment, the subunit can be an annular mounting means surrounding at least the upper peripheral surface of the lens. This annular mounting means can be designed to substantially match the upper and / or outer (side) periphery of the spectacle lens to be mounted. The annular mounting means can be configured to provide rigidity and mechanical strength to the reception unit for holding the spectacle lens by holding the outer and / or upper periphery of the spectacle lens. Since the peripheral portion of the spectacle lens covered by the annular mounting means will not undergo plasma treatment, this portion will be colored in a subsequent coloring step. Accordingly, the said portion of the lens will be cut from the spectacle lens in an appropriate finishing step, if necessary. In one embodiment, the width of the annular mounting means can be at most 15 mm, preferably 1 mm to 10 mm. A width exceeding 15 mm would be impractical, and a width less than 1 mm would endanger the mechanical strength of the lens holder.

[0078] The reception unit may further have means for holding the glasses lenses, preferably at least two means for holding the lenses, which are attachable to and removable from the lenses, or assemblable to and disassemblable from the lenses. The means for holding the lenses can be in any form that can be attached / assembled to the lenses and then removed / disassembled therefrom so that the lens holder does not move during plasma treatment. In one embodiment, the holding means is configured to fit the individual thickness and edge profile of the glasses lenses to be colored and to fix the lenses.

[0079] In an exemplary embodiment, the holding means can be a snap fit. A snap fit is an assembly method used to attach two individual components so as to be joined together. In such a case, the lens can be designed to have corresponding components that are coupled to the holding means. For example, in the case where the glasses lenses are manufactured by injection molding and have a unique edge shape due to injection molding, the holding means can be configured to match the edge profile of the lenses so as to hold the lenses. In this embodiment, the holding means can also function as marking means for marking the alignment position of the lens holder. That is, by assembling the holding means at the corresponding position of the lens, the lens holder will not only be positioned according to the desired alignment with the lens, but also be fixed to the lens during plasma treatment so that the parts that are not desired to be colored are exposed and the parts that are desired to be colored are not exposed, resulting in a coloring pattern at the exact position.

[0080] The holding means can be positioned at a specific angle relative to each other to ensure that the lens is held and fixed during plasma treatment. For example, the two means can be displaced at two symmetric points of the annular mounting means, in other words, at 180° from each other or at 90° - 180° from each other.

[0081] In one embodiment, the lens holder can further have at least one, preferably at least two, marking means for marking alignment positions on the lens. In this case, the lens can also have markings at corresponding positions on the upper and / or outer peripheral surface of the lens. According to this, the lens holder can be easily aligned with the lens at the correct position, thereby enabling the desired coloring pattern to be accurately obtained at the desired position. In one embodiment, in the case where the lens is manufactured by injection molding and has a unique edge shape due to injection molding, the marking means can be configured to match the edge profile of the lens so as to fit the lens at the desired position.

[0082] The lens holder further has a masking unit configured to mask a portion of the surface of the spectacle lens and to protect a portion of the surface of the spectacle lens during plasma treatment. The masking unit is designed to be positioned at a portion of the surface of the spectacle lens where the desired coloring is to be obtained. The masking unit can be designed in any desired shape by taking into account that only the masked portion of the surface of the spectacle lens is subsequently colored in the coloring step.

[0083] In one embodiment, the masking unit can be an independent unit arranged separately and independently from the reception unit. The masking unit will be connected to the reception unit through at least one connection unit configured to connect the masking unit and the reception unit without having contact with the lens. For example, the connection unit can be in the form of a bridge, which is configured to have no contact with the lens, but only have contact between the reception unit and the masking unit. According to this configuration, high flexibility in coloring pattern design can be provided. Even for very small and / or complex patterns, high-quality coloring can be easily obtained. This solves the constraints of tape coloring where coloring patterns not connected to the lens boundary line cannot be realized with high precision due to the difficulty in alignment. In one embodiment, the connection unit can be present on the holding means and / or the annular mounting means of the lens holder.

[0084] In a preferred embodiment, the thickness of the connection unit is at most 10 mm, more preferably 0.1 mm to 5 mm, and most preferably 0.5 mm to 1.5 mm. If the bridging unit is overly thick, undesirable shading on the corresponding surface of the spectacle lens will result. In another embodiment, the height of the connection unit from the surface of the spectacle lens can be at most 20 mm, more preferably 5 mm to 15 mm.

[0085] In another embodiment, the masking unit and the reception unit form a single unit having a continuous surface. The masking unit is configured to cover a portion corresponding to a portion of the surface of the spectacle lens to be colored and to have at least one opening in a portion corresponding to a pre-selected portion of the surface of the spectacle lens that is not desired to be colored and not subjected to selective plasma treatment. The form of the opening can be any form and can be designed in consideration of the desired coloring pattern.

[0086] In a further embodiment, the lens holder can be suitable for providing a coloring pattern having a gradient coloring at the boundary line between the colored and uncolored surfaces, which will hereinafter be referred to as boundary line gradient coloring. For this purpose, the height between a part of the masking unit where the boundary line gradient coloring is provided and the surface of the spectacle lens can be adjusted. The higher the height of a part of the masking unit from the surface of the spectacle lens, the smoother the transition of the gradient of the pattern becomes. By providing a spatial protrusion within the masking unit, thereby generating a spatial vertical margin between the masking unit and the surface of the spectacle lens, the surface of the spectacle lens corresponding to the location of the spatial protrusion undergoes a plasma treatment of adjusted intensity, thereby resulting in boundary line gradient coloring, i.e., gradient coloring at the boundary line. From this perspective, according to the lens holder of this embodiment, a spectacle lens having boundary line gradient coloring can be obtained. This colored spectacle lens can be obtained by any of the methods for selective coloring of the spectacle lens described above and the lens holder described in relation thereto.

[0087] Further features, properties, and advantages of the present invention will become apparent from the following description of the embodiments in connection with the accompanying drawings.

Brief Description of the Drawings

[0088]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

DETAILED DESCRIPTION OF THE INVENTION

[0089] Figure 1 shows a flowchart of a coloring method according to a first aspect of the present invention. In a first step S202, a preselected portion of the surface of the spectacle lens is selected in consideration of a desired coloring pattern. That is, a portion of the surface of the spectacle lens that is not desired to be colored is selected as the preselected portion. In one embodiment where a portion of the surface of the spectacle lens is masked for selective plasma treatment, one spectacle lens (or a plurality of lenses) is assembled / fitted to a masking means or a lens holder, in which case the masking means covers a portion (or a plurality of portions) of the surface of the spectacle lens other than the preselected portion.

[0090] In the second step S204, a preselected portion of the surface of the spectacle lens is selectively processed by plasma. In embodiments using a masking step, the spectacle lens assembled to / fitted on the masking means or the lens holder undergoes plasma treatment, whereby only the preselected portion is exposed to the plasma.

[0091] In the third step S206, a coloring solution having a dye suitable for dyeing the spectacle lens is provided. The lens is to be (partially or wholly) immersed in the coloring solution to obtain the desired coloring. In embodiments using a masking step or masking means, the masking means is to be removed from the lens before the coloring solution is provided. That is, only the spectacle lens is immersed in the coloring solution.

[0092] This step can further include the step of reciprocating the lens into and out of the coloring solution for gradient coloring. In cases where selective gradient coloring is desired, when the lens is fully or partially immersed in the coloring solution, the lens then moves at least partially out of the coloring solution by a swinging motion into and out of the coloring solution to achieve a color degradation that is desirable in terms of hue and intensity.

[0093] In the fourth step S208, a spectacle lens having the desired coloring pattern is obtained.

[0094] After the fourth step S208, there occur the step of removing the coloring solution from the surface of the spectacle lens and a final and optional coating step such as an AR or HC coating.

[0095] FIG. 2 shows a lens holder 10 for coloring a spectacle lens 60 configured to protect the surface of the spectacle lens 60 during selective plasma processing. The lens holder has a reception unit 20 and a masking unit (not shown). In FIG. 2, the masking unit is omitted to show a clear configuration of the reception unit. The lens holder 10 and the spectacle lens 60 are aligned on the surface of the spectacle lens to be colored as depicted in FIG. 2 by a reception unit 20 configured to hold the spectacle lens 60 at a predefined position. The lens holder 10 has a reception unit 20 and a masking unit (not shown). The reception unit 20 can have an annular attachment means 21. The annular attachment means 21 is aligned to match the upper peripheral surface 61 of the lens 60. The thickness may be from 0.1 mm to 20 mm. The upper peripheral surface 61 of the lens 60 is a part of the lens that can be cut or removed after coloring if not needed. After the lens holder 10 is removed from the spectacle lens 60, a coloring solution 70 can be applied to at least a part of the surface of the spectacle lens 60.

[0096] Figure 3A provides a first exemplary embodiment of the present lens holder 10, in which case the lens holder 10 has: (i) a reception unit 20 configured to hold the spectacle lens 60 at a predefined position, having an annular attachment means 21 and at least two holding means 22a, 22b; and (ii) a masking unit 30a. Here, the masking unit 30a and the reception unit 20 are configured as a single unit having a continuous surface. The masking unit 30a has an opening 31a through which the corresponding surface of the spectacle lens is to be exposed to plasma treatment. Here, the opening 31a is depicted as circular for simplicity, but it can be easily understood from the details already provided that the opening 31a can be designed in a flexible manner. According to this, a desired coloring pattern identical to the shape of the masking unit 30a without the opening 31a will be obtained in the coloring step. The lens holder 10 provides positive coloring in which a portion of the surfaces of the spectacle lenses 61, 63 covered by the annular attachment means 21 and the masking unit 30a is colored in a later coloring step. Here, the reception unit 10 has two holding means 22a, 22b that provide fixed holding of the lens for protecting the covered portion of the lens surface during plasma treatment for illustrative purposes. The holding means 22a, 22b are designed to fit the edge profile of the lens.

[0097] By using 3D printing, a relatively flexible design of the lens holder 10 with openings that may in some cases have very small or complex shapes can be obtained. The number and / or shape of the openings can vary according to the desired coloring pattern. The surface of the spectacle lens 60 corresponding to the opening 31a will be exposed during plasma treatment and, as a result, will not be colored in a later coloring step. After plasma treatment, the lens holder 10 will be removed from the lens 60 and a coloring solution 70 will be provided to the spectacle lens 60. As a result, as shown in Figure 3B, a lens 60 having coloring patterns 61, 63 and an uncolored surface 62 is obtained.

[0098] Figure 4A provides a second exemplary embodiment of the present lens holder 10, in which case the lens holder 10 has (i) a reception unit 20 having an annular mounting means 21 and at least two holding means 22a, 22b, and (ii) a masking unit 30b which is a unit positioned independently and separately from the reception unit 20. The masking unit 30b is connected to the reception unit 20 by at least one connection unit 40a, 40b. The masking unit 30b can be connected to the annular mounting means 21 and / or the holding means 22a, 22b. The connection units 40a, 40b are configured such that the lens surface below the connection units 40a, 40b is not exposed to plasma treatment and thus is not in contact with or does not cover the lens surface so as not to be colored in a subsequent coloring step. For this purpose, the thickness and height of the connection units 40a, 40b can be adjusted as described in the relevant parts above. The number and / or shape of the connection units 40a, 40b can vary and can be selected to enable a firm connection between the reception unit 20 and the masking unit 30b, whereby the masking unit 30b does not move during plasma treatment in order to fix a high-quality coloring pattern. In Figure 4A, only one masking unit 30b having a circular shape is provided, but it should be understood that this is for illustrative purposes. It can be easily understood that the number and / or shape of the masking unit 30b (and thus also that of the connection units) can be freely adjusted according to the desired coloring pattern. The remaining part becomes the opening 31b of the lens holder 10. A part of the surface 62 of the spectacle lens corresponding to the opening 31b of the lens holder 10 will be exposed to plasma treatment and thus will have an uncolored surface 62, while the masked parts of the surfaces 61, 63 will not be exposed to plasma treatment and thus will have colored surfaces 61, 63. According to this, the present invention can provide not only positive coloring but also negative coloring as shown in Figure 4B.The colored upper peripheral portion of the lens 61 can be cut in a finishing step if necessary.

[0099] Figures 5A and 5B provide a third exemplary embodiment of the lens holder 10 according to the first or second embodiment, further having at least one marking unit 50a, 50b configured to mark the alignment position of the lens holder 10 on the spectacle lens. The marking units 50a, 50b are not limited to the embodiments depicted herein in these figures and can be in any form as long as they can assist in the accurate alignment of the lens holder 10 on the lens 60 to provide a desired coloring pattern 63 at a desired position. Also, in this embodiment, the lens 60 will have portions 66a, 66b corresponding to those of the marking units 50a, 50b on the upper and / or outer peripheral surface of the lens 60. According to this, the lens holder 10 can be easily and accurately aligned with the lens 60 at the correct position, thereby enabling the desired coloring pattern to be obtained accurately at the desired position.

[0100] Figures 6A and 6B show a fourth exemplary embodiment of the lens holder, in which case the lens holder of the first or second embodiment further has marking units 50a', 50b' designed to fit the edge profile of the spectacle lens. For example, when the spectacle lens is manufactured by injection molding, the lens may have unique shapes at the side edges, such as the round protrusion 66a' (left) and the square protrusion 66b' (right) depicted for illustrative purposes as shown in Figure 6B. In this embodiment, the marking units 50a', 50b' can be designed to fit the existing edge profiles of the lenses 66a', 66b', and preferably can be designed by using 3D printing. This has the advantage in that no further marking of the lens is required and the initial lens design can be used as is to align the marking units 50a', 50b', and thus the lens holder 10, at the exact position. In some cases, the marking units 50a', 50b' may further function as holding units, and in such cases, the separate holding units 22a, 22b may be unnecessary.

[0101] Figures 7A and 7B show a fifth exemplary embodiment of a unique lens holder 10 and a lens 60 having a boundary gradient coloring 64 manufactured using the lens holder 10. In this embodiment, the masking unit 30c can further have a spatial protrusion 32 in a state adjacent to the opening 31c. Due to the spatial gap between the spatial protrusion 32 of the masking unit 30c and the average height of the surface of the spectacle lens 60 or the surface of the masking unit 30c, the lens 60 can have a boundary gradient coloring 64 having a boundary line with a smooth transition 64 in the coloring intensity from the colored surface 63 to the uncolored surface 62. Depending on the height of the spatial protrusion 32 from the surface of the spectacle lens 60, the coloring intensity and the degree of transition can vary. In contrast, the boundary line between the colored portion and the uncolored portion manufactured using the lens holder 10 having the masking units 30a, 30b without the spatial protrusion 32 will have a sharp (non-gradient) transition in the coloring intensity from the colored surface to the uncolored surface.

[0102] As shown in FIG. 7B, at the boundary line 65 (left side, between the colored surface 63 and the uncolored surface 62) completely covered by the masking unit 30, the transition in the coloring intensity will be sharp (non-gradient), while at the boundary line 64 (right side, between the colored surface 63 and the uncolored surface 62) where the corresponding portion of the lens holder 10 has a spatial gap between the spatial protrusion 32 and the surface of the spectacle lens 60, the transition in the coloring intensity from the colored surface 63 to the uncolored surface 62 will be smooth.

Claims

1. A method of coloring a spectacle lens (60) having a surface, comprising: (i) selectively plasma-treating a preselected portion (62) of the surface of the spectacle lens to induce crosslinking in the preselected portion (62), thereby preventing a coloring solution (70) from penetrating into the preselected portion (62); (ii) providing the coloring solution (70) to at least a portion (63) of the surface of the spectacle lens that has not been treated by the plasma treatment; The method is characterized in that the spectacle lens (60) has a polymeric lens material.

2. - masking a portion (63) of the surface of the spectacle lens other than the preselected portion (62) before the plasma treatment; - demasking the masked portion (63) of the surface of the spectacle lens after the plasma treatment and before providing the coloring solution (70) to the spectacle lens (60). The method according to claim 1, characterized by comprising the above steps.

3. The method according to claim 1 or 2, characterized in that the plasma treatment is carried out using a gas discharge.

4. The method according to claim 1 or 2, characterized in that the coloring solution (70) is an aqueous coloring solution.

5. The step of masking the portion (63) of the surface of the spectacle lens (60) other than the preselected portion (62) is carried out by a lens holder (10) at a predefined position having a reception unit (20) configured to hold the spectacle lens (60) and a masking unit (30) for protecting the portion (63) of the surface of the spectacle lens (60) other than the preselected portion (62) during the plasma treatment. The method according to claim 2 is characterized by this.

6. A computer program having instructions for causing a computer to execute the steps of the method according to claim 1 or 2, wherein the step of plasma treatment is carried out by a device suitable for plasma treatment and the step of providing the coloring solution is carried out by a device suitable for providing the coloring solution.

Images