Method for manufacturing optical components

Abstract

To provide a technology which can add markings to an optical member without incurring a decrease in quality of the optical member.SOLUTION: An optical member manufacturing method and its related technologies, comprise: irradiating, with an ultrashort pulse laser, an antireflection coating of a multilayer structure which is formed so as to cover an optical surface of an optical substrate and includes a low refractive index layer and a high refractive index layer to partially remove a prescribed layer that includes the outermost surface layer of the multilayer structure, thereby applying desired laser processing. The pulse width of the ultrashort laser pulse is 10 femtoseconds or more and less than 100 picoseconds. The antireflection coating includes a reaction layer having relatively higher reactivity to the irradiation with the ultrashort pulse laser than the other layers included in the multilayer structure, and the reaction layer is removed at least in part by the irradiation, and thereby subjected to laser processing enabling visual recognition by visible light.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a method for manufacturing an optical member, an optical member, and glasses.

Background Art

[0002] As a spectacle lens, there is one in which the optical surface of a lens substrate is coated with a thin film such as a hard coat film or an antireflection film. In recent years, it has been proposed to mark a spectacle lens by partially removing some layers of the thin film by laser irradiation of the thin film (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the conventional marking by laser irradiation, it is not easy to precisely remove only some layers of the thin film, and there is also a risk of damaging the other layers constituting the thin film and the lower layer portion of the layer to be removed, such as the lens substrate. Therefore, when applied to a product of a spectacle lens, there is concern about a decrease in quality.

[0005] An object of the present disclosure is to provide a technique capable of marking an optical member without causing a decrease in the quality of the optical member.

Means for Solving the Problems

[0006] A first aspect of the present invention is A method for manufacturing an optical component, comprising irradiating an anti-reflective film having a multilayer structure including a stack of low-refractive-index layers and high-refractive-index layers, formed to cover the optical surface of an optical substrate, with an ultrashort pulse laser, and partially removing a predetermined layer including the outermost layer of the multilayer structure to perform desired laser processing, The aforementioned ultrashort pulse laser has a pulse width of 10 femtoseconds or more and less than 100 picoseconds. The anti-reflective coating includes a reaction layer that is relatively more reactive to irradiation with the ultrashort pulse laser than the other layers in the multilayer structure. By irradiation, the reaction layer is at least partially removed, thereby performing the laser processing that is visible in visible light. This is a method for manufacturing optical components.

[0007] A second aspect of the present invention is: In the removal of the reaction layer, the reaction layer disappears by sublimation or evaporation in the thickness direction, and as a result of this disappearance, other layers stacked above the reaction layer are removed. This is a method for manufacturing an optical component as described in the first embodiment.

[0008] A third aspect of the present invention is: In the irradiated area where the reaction layer has been removed by the aforementioned irradiation, the high refractive index layer included in the multilayer structure is exposed. This is a method for manufacturing an optical component as described in the first or second embodiment.

[0009] A fourth aspect of the present invention is: The reaction layer is a conductive layer with higher conductivity than the other layers constituting the multilayer structure. A method for manufacturing an optical component according to any one of the first to third embodiments.

[0010] A fifth aspect of the present invention is: The reaction layer contains Sn and O, This is a method for manufacturing an optical component according to any one of the first to fourth embodiments.

[0011] A sixth aspect of the present invention is: The optical component is an eyeglass lens. This is a method for manufacturing an optical component according to any one of the first to fifth embodiments.

[0012] A seventh aspect of the present invention is: The aforementioned ultrashort pulse laser has a pulse width of 0.1 picoseconds or more and less than 50 picoseconds. A method for manufacturing an optical component according to any one of the first to sixth embodiments.

[0013] An eighth aspect of the present invention is: Optical substrate for forming an optical surface, The optical substrate comprises an anti-reflective coating that covers the optical surface, The anti-reflective film has a multilayer structure including a stack of a low refractive index layer and a high refractive index layer. The anti-reflective coating includes a reactive layer whose reactivity to irradiation with an ultrashort pulse laser is relatively higher than that of other layers included in the anti-reflective coating. In the removed area formed by at least partially removing a predetermined layer including the outermost layer of the multilayer structure, the high refractive index layer located below the reaction layer, or the partially remaining reaction layer, is exposed. This is an optical component in which the aforementioned removed area has been processed so that it can be seen by visible light.

[0014] A ninth aspect of the present invention is: The high refractive index layer exposed by the removal of the low refractive index layer has a ratio t1 / t2 of the thickness t1 of the area where the low refractive index layer is removed to the thickness t2 of the area where the low refractive index layer is not removed, which is within the range of 0.90 to 1.00. This is the optical component described in the eighth aspect.

[0015] A tenth aspect of the present invention is: The visible processing can be seen from the processed surface side of the optical component, and also from the back side of the processed surface. The optical component is as described in the eighth or ninth embodiment.

[0016] The eleventh aspect of the present invention is that the visible processing has its visibility changed by the relative position or angle between the observer and the illumination light with respect to the optical member. It is the optical member according to any one of the eighth to tenth aspects.

[0017] The twelfth aspect of the present invention is that the optical member is an eyeglass lens. It is the optical member according to any one of the eighth to eleventh aspects.

[0018] The thirteenth aspect of the present invention is that an eyeglass lens that is an optical member manufactured by the manufacturing method of the optical member according to any one of the first to seventh aspects, or an eyeglass lens that is an optical member according to any one of the eighth to twelfth aspects, fitted into a frame is an eyeglass.

Advantages of the Invention

[0019] According to the present invention, marking can be performed on the optical member without causing a deterioration in the quality of the optical member.

Brief Description of the Drawings

[0020] [Figure 1] It is a plan view showing an example of processing of an eyeglass lens according to an embodiment of the present invention. [Figure 2] It is a flowchart showing an example of the procedure of the manufacturing method of an eyeglass lens according to an embodiment of the present invention. [Figure 3] It is a side sectional view showing an example of the laminated structure of a thin film in an eyeglass lens according to an embodiment of the present invention. [Figure 4A] It is an explanatory view showing a schematic configuration example of a laser processing apparatus used in the manufacturing method of an eyeglass lens according to an embodiment of the present invention, and shows a state of being configured to irradiate laser light onto an AR film through a laser light source unit, an AOM (Acousto Optics Modulator) system unit, a beam shaper unit, a galvanometer scanner unit, and an optical system. [Figure 4B] This is an explanatory diagram showing a schematic configuration example of a laser processing apparatus used in a method for manufacturing eyeglass lenses according to one embodiment of the present invention. The diagram shows how the apparatus is configured to allow irradiation of an AR film with laser light (i.e., an ultrashort pulse laser) via an optical system, etc., to be performed with a defocus setting. [Figure 5A] This is an explanatory diagram showing an example of the main components of an eyeglass lens according to one embodiment of the present invention. [Figure 5B] This is an explanatory diagram showing an example of the main components of an eyeglass lens according to one embodiment of the present invention, and shows a specific example of the results of electron microscope observation of a cross-section of an AR film. [Figure 6A] Figure 5B shows a micrograph (magnification 200x) of the results of a test in which a dot pattern was formed on the AR film of eyeglass lens 1 using a laser beam with a wavelength of 1064 nm and a pulse width of 100 femtoseconds or more and less than 1 picosecond. [Figure 6B] Figure 5B shows a micrograph (magnification 200x) of the results of a test in which a dot pattern was formed on the AR film of eyeglass lens 1 using a laser beam with a wavelength of 532 nm and a pulse width of 100 femtoseconds or more and less than 1 picosecond. [Figure 7A] Figure 5B shows a micrograph (magnification 200x) of the results of a test in which a dot pattern was formed on the AR film of eyeglass lens 1 using a laser beam with a wavelength of 1064 nm and a pulse width of several tens of picoseconds. [Figure 7B] Figure 5B shows a micrograph (magnification 200x) of the results of a test in which a dot pattern was formed on the AR film of eyeglass lens 1 using a laser beam with a wavelength of 532 nm and a pulse width of several tens of picoseconds. [Figure 7C] Figure 5B shows a micrograph (magnification 200x) of the results of a test in which a dot pattern was formed on the AR film of eyeglass lens 1 using a laser beam with a wavelength of 355 nm and a pulse width of several tens of picoseconds. [Figure 8A]Figure 5B shows a micrograph (magnification 50x) of the results of a test in which a solid pattern was formed by overlapping dot patterns on the AR film of the spectacle lens 1, using a laser beam with a wavelength of 355 nm and a pulse width of several tens of picoseconds. [Figure 8B] Figure 5B shows a micrograph (magnification 200x) of the results of a test in which a solid pattern was formed by overlapping dot patterns on the AR film of the spectacle lens 1, using a laser beam with a wavelength of 532 nm and a pulse width of several tens of picoseconds. [Figure 9A] Figure 5B shows a micrograph (magnification 50x) of the results of a test in which a dot pattern was formed on the AR film of eyeglass lens 1 using a laser beam with a wavelength of 355 nm and a pulse width of several tens of nanoseconds. [Figure 9B] The images in Figure 5B show microscopic photographs of the results of a test in which a dot pattern was formed on the AR film of the spectacle lens 1 using a laser beam with a wavelength of 266 nm and a pulse width of several tens of nanoseconds (the left image is magnified 50x, and the four images on the right are magnified 500x). [Modes for carrying out the invention]

[0021] Embodiments of the present invention will be described below with reference to the drawings.

[0022] In this embodiment, the following explanation will be given using the case where the optical element is an eyeglass lens as an example.

[0023] Eyeglass lenses have two optical surfaces: an object-facing surface and an eye-facing surface. The "object-facing surface" is the surface that faces the object when eyeglasses with lenses are worn by the wearer. The "eye-facing surface" is the opposite surface, that is, the surface that faces the eye when eyeglasses with lenses are worn by the wearer. The object-facing surface is generally convex, and the eye-facing surface is concave; in other words, eyeglass lenses are typically meniscus lenses.

[0024] Figure 1 is a plan view showing an example of a processed spectacle lens according to this embodiment. In this embodiment, a circular spectacle lens 1 in plan view (for example, outer diameter φ60~80 mm) is subjected to a lens shape processing (frame cutting) to adjust the outer shape of the lens to match the frame shape 2 of the spectacle frame worn by the wearer. Before or after this, a decorative pattern 3 representing letters, symbols, designs, etc., such as a logo or house mark, is marked on the optical surface so that it is located within the lens area after frame cutting.

[0025] The marking of the decorative pattern 3 could be performed, for example, using laser irradiation processing that allows for precise control of the irradiation position based on digital data. However, it is undesirable for the marking to cause a decrease in lens quality or function. Therefore, in this embodiment, the marking of the decorative pattern 3 is performed by the processing procedure described below.

[0026] (1) Eyeglass lens manufacturers Here, we will specifically describe the processing procedure for eyeglass lenses, including the marking of decorative patterns, that is, the procedure for manufacturing eyeglass lenses according to this embodiment. Figure 2 is a flowchart showing an example of the procedure for manufacturing eyeglass lenses according to this embodiment.

[0027] In manufacturing eyeglass lenses, first, a lens substrate, which is an optical substrate, is prepared, and this lens substrate is subjected to polishing according to the prescription information of the eyeglass wearer, and dyeing is performed as necessary (Step 101, hereafter steps will be abbreviated as "S"). As the lens substrate, for example, a resin material with a refractive index (nD) of about 1.50 to 1.74 is used. Specifically, examples of resin materials include allyl diglycol carbonate, urethane resin, polycarbonate, thiourethane resin, and episulfide resin. However, it may be made of other resin materials that can obtain the desired refractive index, or it may be made of inorganic glass. The lens substrate also has optical surfaces for forming a predetermined lens shape on both the surface facing the object and the surface facing the eyeball. The predetermined lens shape may be a single-focus lens, a multifocal lens, a progressive power lens, etc., but in any case, each optical surface is made of a curved surface specified based on the prescription information of the optician. The optical surfaces are formed, for example, by polishing, but they may also be cast (molded) products that do not require polishing. Furthermore, the polishing and dyeing treatments for the lens substrate can be carried out using publicly known techniques, and a detailed explanation of these procedures is omitted here.

[0028] Subsequently, a hard coat film (HC film) is formed on at least one optical surface of the lens substrate, preferably on both optical surfaces (S102). The HC film is constructed using a curable material containing, for example, a silicon compound, and is formed to a thickness of approximately 3 μm to 4 μm. The refractive index (nD) of the HC film is close to that of the lens substrate material, for example, around 1.49 to 1.74, and the film composition is selected according to the lens substrate material. By coating with such an HC film, the durability of eyeglass lenses can be improved. HC films can be formed, for example, by a dipping method using a solution containing a curable material with silicon compounds.

[0029] After the HC film is formed, an anti-reflective (AR) film is then formed on top of the HC film (S103). AR films are films that have a multilayer structure in which films with different refractive indices are stacked, and prevent light reflection through interference. Specifically, AR films are composed of a multilayer structure in which a low refractive index layer and a high refractive index layer are stacked. The low refractive index layer is made of silicon dioxide (SiO2), for example, with a refractive index of about 1.43 to 1.47. Furthermore, the high refractive index layer is made of a material having a higher refractive index than the low refractive index layer, and is composed of materials such as zirconium oxide (ZrO2), tin oxide (SnO2), niobium oxide (Nb2O5), tantalum oxide (Ta2O5), titanium oxide (TiO2), yttrium oxide (Y2O3), aluminum oxide (Al2O3), and mixtures thereof (e.g., indium tin oxide (ITO)).

[0030] Of these, the high-refractive-index layer containing Sn and O functions as a reactive layer because its reactivity to the ultrashort pulse laser described later is greater than that of the other layers. Specifically, this includes SnO2 and ITO.

[0031] In this specification, the term "reaction layer" refers to a layer with a low excitation energy when irradiated with a laser. In one embodiment of the present invention, an ultrashort pulse laser is irradiated. The SnO2 layer exhibits extremely low excitation energy due to multiphoton absorption (e.g., two-photon absorption), making it highly reactive. This is also true for the ITO layer, which can also serve as a reaction layer in this specification. As a result, in one embodiment of the present invention, the SnO2 layer (or ITO layer) sublimes or evaporates and disappears from the irradiated area together with the SiO2 layer on the upper side. In one embodiment of the present invention, the reaction layer that is relatively more reactive than the other layers included in the multilayer structure refers to the SnO2 layer or the ITO layer. The reaction layer may be set as the reaction layer that is the most reactive of the other layers included in the multilayer structure.

[0032] Furthermore, the outermost layer of the multilayer AR film is configured to be a low refractive index layer (for example, an SiO2 layer). By coating the film with such an AR film, the laser-processed pattern in this embodiment can be made more visible due to the difference in visible light reflectivity caused by irradiation with illumination light.

[0033] Furthermore, it is preferable that the bottom layer (substrate side) of the multilayer structure is also a low refractive index layer (for example, an SiO2 layer).

[0034] AR films can be deposited, for example, by applying ion-assisted evaporation.

[0035] A water-repellent film may be formed on the low refractive index layer, which is the outermost layer of the AR film. The water-repellent film may also be called an anti-fouling film. The formation of the water-repellent film may be carried out before or after the marking according to this embodiment. A water-repellent film is a film that provides water repellency to a surface, and can be formed, for example, by applying a fluorine-based compound solution such as metaxylene hexafluoride. The water-repellent film can be formed in the same way as the AR film, for example, by applying ion-assisted deposition. Furthermore, other functional layers may be deposited on the AR film. Whether or not such functional layers contain metal components is acceptable, as long as the precise processing effect achieved by laser irradiation is obtained. Also, such functional layers may be a uniform film or scattered on the surface.

[0036] Through the film deposition process described above, a thin film with a layered structure, as shown in Figure 3, is formed on the optical surface of the lens substrate.

[0037] Figure 3 is a side cross-sectional view showing an example of a thin film layered structure according to this embodiment.

[0038] The laminated structure in the diagram is constructed by sequentially laminating an HC film 12, an AR film 13, and a water-repellent film 14 on the optical surface of a lens substrate 11. The AR film 13 has a multilayer structure in which a low refractive index layer, an SiO2 layer 13a, and high refractive index layers, an SnO2 layer 13b and a ZrO2 layer 13c, are laminated, and the outermost layer (i.e., the surface on the side of the water-repellent film 14) is the SiO2 layer 13a. Here, the SnO2 layer is both a high refractive index layer and a reactive layer.

[0039] After the thin film is formed, the spectacle lens on which the thin film has been formed is then subjected to frame cutting and marking of a decorative pattern, as shown in Figure 2. For example, if decorative processing is to be performed after frame cutting (S104: after cutting), first, one optical surface of the spectacle lens to be processed (specifically, the optical surface that will not be subjected to the decorative processing described later) is mounted on a special jig for jig blocking (S105). Then, the blocked spectacle lens is set in a lens shaping machine, and lens shaping (frame cutting) is performed on the spectacle lens to cut the outer shape of the spectacle lens into the frame shape (S106). Since jig blocking and frame cutting can be performed using publicly known techniques, a detailed explanation is omitted here.

[0040] After the frame cutting process, decorative processing (i.e., marking of the decorative pattern) is then performed. For the decorative processing, first, while the eyeglass lens is still blocked, the lens height of the processing area (i.e., the three-dimensional shape of the processing area on the processing surface) is measured on the surface to be processed (specifically, the optical surface on the side that is not blocked) (S107). The measurement method is not particularly limited, but for example, it can be done using a non-contact type three-dimensional measuring machine. The processing area is the region that includes the laser scanning area, which will be described later.

[0041] After measuring the lens height in the processing area, laser processing is performed by irradiating the processing area with laser light, and a raster scan is performed to move the laser beam's irradiation position based on pre-prepared pattern data (S108). A vector scan may be used instead of a raster scan. As a result, a decorative pattern is marked on the processing area of ​​the surface of the eyeglass lens. Details of the laser processing for marking the decorative pattern will be described later.

[0042] After marking the decorative pattern, the eyeglass lens is removed from the special jig using a deblocking process (S109). The removed eyeglass lens is then cleaned to remove any remaining marking residue or foreign matter (S110). Finally, after a final lens appearance inspection (S111), the manufacturing of the eyeglass lens is completed.

[0043] On the other hand, for example, if frame cutting is performed after decorative processing (S104: before cutting), first, the lens height of the processing area (i.e., the three-dimensional shape of the processing area on the processing surface) of the spectacle lens to be processed is measured (S112). The measurement method is the same as in the case where decorative processing is performed after frame cutting as described above.

[0044] After measuring the lens height in the processing area, laser processing is performed by irradiating the processing area with laser light, and a raster scan is performed to move the laser beam's irradiation position based on pre-prepared pattern data (S113). A vector scan may be used instead of a raster scan. As a result, a decorative pattern is marked on the processing area of ​​the surface of the eyeglass lens. Details of the laser processing for marking the decorative pattern will be described later.

[0045] After marking the decorative pattern, the marked spectacle lens is subjected to frame cutting. For frame cutting, first, one optical surface of the spectacle lens to be processed is mounted on a special jig (S114), the blocked spectacle lens is set in a lens shaping machine, and lens shaping (frame cutting) is performed on the spectacle lens to cut the outer shape of the spectacle lens into a frame shape (S115). After frame cutting, the spectacle lens is removed from the special jig (S116), and the removed spectacle lens is cleaned to remove any remaining material or foreign matter from the processing (S117). Finally, after a final lens appearance inspection (S118), the manufacture of the spectacle lens is completed.

[0046] (2) Details of laser processing Next, we will explain in more detail the laser processing used when marking decorative patterns.

[0047] In this embodiment, a laser beam is irradiated onto the AR film 13 covering the optical surface of the lens substrate 11, thereby partially removing a predetermined layer including the SiO2 layer 13a, which is the outermost layer of the AR film 13, and thus marking a decorative pattern can be performed. Specifically, when laser light that has passed through the outermost SiO2 layer reaches the SnO2 layer below it, the SnO2 layer sublimes or evaporates due to the irradiation energy and disappears from the irradiated area along with the upper SiO2 layer. In other words, a predetermined layer, including the outermost SiO2 layer 13a, is partially removed by laser processing using laser light. At this time, the irradiated area is marked with a decorative pattern after a removal process that exposes the high refractive index layer below it. Here, the high refractive index layer to be exposed is, for example, the ZrO2 layer 13c.

[0048] The SnO2 layer 13b can be formed to a thin thickness (for example, 3 to 20 nm, more preferably 3 to 10 nm). In this embodiment, it was set to 5 nm.

[0049] Furthermore, in the above, SnO2 functions as the reaction layer, which is the most reactive to laser irradiation. This reaction layer preferably contains Sn and O, and in addition to SnO2, ITO can be used.

[0050] Furthermore, in the above, SnO2 is removed by sublimation or evaporation, and the ZrO2, which is a high refractive index layer located beneath it, is exposed at the irradiated area. However, the reaction layer does not necessarily need to be completely removed, and some may remain at the irradiated area. For example, the reaction layer may be removed at least partially in the thickness direction of the layer by laser irradiation. Another example of partial removal is that, by laser irradiation, the reaction layer may remain at the laser irradiated area not only in the thickness direction of the layer, but also when viewed from the direction of laser irradiation (when viewed from above). In the example in this paragraph, it is acceptable for only a portion of the ZrO2 to be exposed. This is because, like ZrO2, SnO2 (or ITO) is also a high refractive index material, and even if some SnO2 remains when the removal area is viewed from above, there will be no problem with visibility. Therefore, it is sufficient for the high refractive index layer located beneath the reaction layer, or the partially remaining reaction layer, to be exposed.

[0051] The phenomena that occur during laser irradiation are thought to be as follows: The reaction layer (such as SnO2 or ITO) is preferably a conductive layer that has higher conductivity than the other layers included in the layered structure.

[0052] According to the inventor's research, the reaction layer made of SnO2 has a smaller energy corresponding to the band gap at which excitation occurs when irradiated with a laser under the conditions described later, compared to the upper (outermost surface) SiO2 layer and the lower ZrO2 layer. For this reason, it is most likely to disappear by sublimation / evaporation compared to the adjacent upper and lower layers.

[0053] In this process, a phenomenon known as multiphoton absorption (e.g., two-photon absorption) is thought to occur, allowing for processing with extremely high energy efficiency. Furthermore, the fact that SnO2 is a conductive layer is considered to be advantageous in this process.

[0054] Furthermore, regarding concerns that the lower layer of ZrO2 may be damaged by evaporation or dissolution due to the irradiation energy after the disappearance of SnO2, by controlling the irradiation conditions to take advantage of the delay before such damage occurs, it is possible to effectively remove only the reaction layer and the layers above it. It was found that selecting an ultrashort pulse laser, as described later, is advantageous for such precise processing control involving the multi-molecular absorption phenomenon described above.

[0055] Here, we will briefly explain the laser processing equipment used for laser processing. Figure 4 is an explanatory diagram showing a schematic configuration example of a laser processing apparatus used in the method for manufacturing eyeglass lenses according to this embodiment.

[0056] As shown in Figure 4A, the laser processing apparatus used in this embodiment comprises a laser light source unit 21, an AOM (Acousto Optics Modulator) system unit 22, a beam shaper unit 23, a galvanometer scanner unit 24, and an optical system 25, and is configured to irradiate the AR film 13 with laser light via these units 21 to 25.

[0057] The laser light source unit 21 emits laser light used for laser processing and is configured to emit an ultrashort pulse laser.

[0058] In this embodiment, the lower limit of the pulse width of the ultrashort pulse laser is not particularly limited and may be greater than 0 femtoseconds, but it is preferably 0.01 picoseconds (10 femtoseconds) or greater, and using 0.1 picoseconds or greater (including 1 picosecond or greater) is advantageous in terms of equipment maintenance and cost, and is more suitable for commercial use.

[0059] For example, pulses with a pulse width of 0.01 picoseconds or more and less than 100 picoseconds, preferably 0.01 picoseconds or more and less than 50 picoseconds, and more preferably 0.01 picoseconds or more and less than 15 picoseconds can also be used.

[0060] Furthermore, for example, a pulse width of 0.1 picoseconds or more and less than 100 picoseconds can be used, preferably a pulse width of 0.1 picoseconds or more and less than 50 picoseconds, and more preferably a pulse width of 0.1 picoseconds or more and less than 15 picoseconds.

[0061] Additionally, pulses with a pulse width of 0.01 picoseconds or more but less than 1 picosecond (or less than 0.1 picoseconds) are also usable.

[0062] The wavelength of the ultrashort pulse laser can be, for example, 355 nm THG (Third Harmonic Generation) or 532 nm SHG (Second Harmonic Generation), as well as a fundamental wavelength of 1064 nm. During irradiation, the irradiation beam diameter can be selected according to the desired processing design. To process fine designs with high resolution, it is effective to narrow the beam diameter; in this case, shorter wavelengths are advantageous, so among the above wavelengths, 532 nm is preferred, and 355 nm is more preferred. Alternatively, 266 nm FHG (Fourth Harmonic Generation) is also suitable.

[0063] The pulse energy of an ultrashort pulse laser is, for example, between 0.1 μJ and 30 μJ (maximum of about 60 μJ) at 50 kHz. The beam diameter of an ultrashort pulse laser is, for example, between 10 μm and 30 μm.

[0064] This study revealed the following regarding the laser irradiation conditions.

[0065] (1) When the pulse width of the ultrashort pulse laser is less than 0.1 picoseconds Good processing can be performed at any wavelength between 266 and 1064 nm. Shorter wavelengths are more advantageous for microfabrication. However, this results in a higher production burden, including initial equipment investment and running costs. (2) When the pulse width of the ultrashort pulse laser is 0.1 picoseconds or more and less than 1 picosecond Good processing can be performed at any wavelength between 266 and 1064 nm. Shorter wavelengths are more advantageous for microfabrication. (3) When the pulse width of the ultrashort pulse laser is 1 picosecond or more and less than 100 picoseconds Good processing can be performed at any wavelength between 266 and 1064 nm. It is also suitable in terms of equipment cost and stability of production conditions. Within this wavelength range, shorter wavelengths are more advantageous for microfabrication. (4) When the pulse width of the ultrashort pulse laser is 100 picoseconds or more and less than 1 nanosecond The processing stability becomes non-uniform depending on the applied wavelength. For example, if a short wavelength of 266 nm is used as the applied wavelength, damage to the lower layer is likely to occur along with the reaction of SnO2. Furthermore, even at 355 nm, slight fluctuations in irradiation conditions can lead to a loss of processing uniformity, making it impossible to prevent the removal process from reaching the layer below SnO2. (5) The pulse width of the ultrashort pulse laser is 1 nanosecond or longer. It is not possible to selectively and stably remove SnO2 and the layers on the surface.

[0066] In cases (4) and (5) above, the visibility of the processed pattern will be affected. For example, in eyeglass lenses, there is a risk of interference with the wearer's field of vision. Also, when observing the formed decorative pattern, an imperfect visibility state is likely to occur, where the lens may be perceived as having foreign matter or dirt rather than being a clear lens, unless the lighting conditions are such that the pattern is clearly visible to the observer.

[0067] To prevent the aforementioned problems, it is essential that the removal process using an ultrashort pulse laser is uniform in terms of processing diameter and processing depth. To achieve this, it is considered useful to control and utilize the duration of the energy irradiated and the delay of ablation of the underlying material by applying a predetermined ultrashort pulse width.

[0068] As long as such an ultrashort pulse laser can be emitted, the specific configuration of the laser light source unit 21 or the combination of wavelength and pulse width is not particularly limited.

[0069] The AOM system unit 22 suppresses excessive laser beam irradiation, which can cause uneven processing during laser processing, by canceling the laser beam output of the galvanometer scanner unit 24 immediately after it starts operating and just before it finishes operating.

[0070] The beam shaper unit 23 converts the laser light from the laser light source unit 21 from a Gaussian-type energy distribution to a top-hat-type energy distribution, thereby enabling laser processing with laser light that has a uniform energy distribution. In particular, applying a top-hat type distribution allows for stable and uniform machining when attempting to form a machining area of ​​a predetermined size by partially overlapping multiple beam spots. This is because it suppresses the localized excess energy added due to the overlapping of spots.

[0071] The galvanometer scanner unit 24 enables scanning by moving the irradiation position of the laser beam from the laser light source unit 21 in two or three dimensions, thereby allowing the marking of a desired pattern to be performed by laser processing. The scannable range of the laser beam by the galvanometer scanner unit 24 (i.e., the maximum laser processing area) 4 is set to a size and shape that can completely encompass the outer shape of the spectacle lens to be processed (see Figure 1).

[0072] The optical system 25 is composed of a combination of optical lenses such as telecentric lenses and mirrors, and guides the laser light from the laser light source unit 21 so that it reaches the part of the eyeglass lens to be processed.

[0073] Furthermore, as shown in Figure 4B, the laser processing apparatus used in this embodiment is configured to allow irradiation of the AR film 13 with laser light (i.e., an ultrashort pulse laser) via the optical system 25, etc., with a defocus setting. A defocus setting means that the focal position F of the irradiated laser light is set to be a predetermined defocus distance away from the surface of the AR film 13, which is the area to be processed by the laser light. By irradiating with laser light with such a defocus setting, the beam energy can be dispersed on the surface of the AR film 13 irradiated with the laser light, thereby enabling uniform film removal processing. This is particularly useful when the height of the irradiated area may vary due to the surface shape of the AR film 13. However, it is not necessarily limited to a defocus setting; for example, the laser light may be irradiated with a focus setting where the focal position F coincides with the surface of the AR film 13, or with an in-focus setting where the focal position F is away in the opposite direction to the defocus setting.

[0074] Next, we will explain the procedure for laser processing using the laser processing apparatus configured as described above.

[0075] In laser processing, first, the spectacle lens to be processed is set in the laser processing device. At this time, the spectacle lens is set so that the optical surface of the spectacle lens, more specifically the surface of the AR film 13 on that optical surface, becomes the surface to be processed. The optical surface to be processed may be either the surface facing the object or the surface facing the eyeball, but in this case, for example, the surface facing the eyeball is used as the surface to be processed.

[0076] After setting the eyeglass lens, the laser light source unit 21 and the galvanometer scanner unit 24 are operated based on pre-prepared pattern data (i.e., pattern data with a predetermined resolution created based on the decorative pattern to be obtained). As a result, an ultrashort pulse laser is irradiated onto the processing area of ​​the surface of the eyeglass lens in a pattern shape corresponding to the decorative pattern.

[0077] When an ultrashort pulse laser is irradiated, the ultrashort pulse laser penetrates the water-repellent film 14 on the surface of the eyeglass lens to be processed and reaches the AR film 13 on that surface. Upon reaching the AR film 13, non-heating processing is performed by the ultrashort pulse laser.

[0078] The ablation process in this embodiment is a technology that enables highly energy-efficient processing through the multiphoton absorption phenomenon of an ultrashort pulse laser. More specifically, it is a removal process that minimizes the influence of heat around the processing area, and is performed by instantaneously melting, evaporating, or sublimating the laser beam-irradiated area and scattering the material. With this non-heating process, highly reactive materials are instantly removed at the irradiation site, resulting in less heat impact on the surrounding area and enabling processing with reduced thermal damage (such as deformation due to heat).

[0079] The laser processing according to this embodiment can be performed as ablation processing, which is a non-thermal process. Such processing can induce a multiphoton absorption process (e.g., a two-photon absorption process) that brings about the multiphoton absorption phenomenon mentioned above. Therefore, even for materials that are relatively transparent (high transmittance) to the laser, efficient and good processing can be performed by multiphoton absorption. In this case, the range of applicable laser wavelengths is wide, and in addition to 355 nm (THG) and 532 nm (SHG), 1064 nm can be advantageously used as the wavelength of the laser light.

[0080] As mentioned above, picosecond and femtosecond lasers with short pulse widths are advantageous for inducing the multiphoton absorption described above. Specifically, for example, the pulse width can be less than 100 picoseconds, preferably less than 50 picoseconds, and even more preferably less than 1 picosecond (i.e., femtosecond).

[0081] When non-heating processing is performed by irradiation with an ultrashort pulse laser, the AR film 13 penetrates through the SiO2 in the multilayer structure that constitutes the AR film 13 to reach the reaction layer (SnO2 in this embodiment), and as the reaction layer reacts instantaneously and sublimes / evaporates, the outermost SiO2 layer 13a is removed. In this way, only a predetermined layer, including the differential surface layer of the anti-reflective film, is partially removed in a pattern shape corresponding to the decorative pattern. In addition, the corresponding portion of the water-repellent film 14 is also removed. As a result, the ZrO2 layer 13c, located below the SnO2 layer 13b, is exposed at the irradiated area.

[0082] By performing the laser processing described above, a predetermined layer including the SiO2 layer 13a, which is the outermost layer of the AR film 13, is partially removed (a removal area is formed), exposing the ZrO2 layer 13c as a high refractive index layer. This allows for the marking of a decorative pattern on the processed surface of the eyeglass lens. As described above, the area where the laser irradiation is performed will be partially processed within the workpiece surface.

[0083] (3) Composition of eyeglass lenses Next, the configuration of the spectacle lens obtained by the manufacturing method described above, that is, the configuration of the spectacle lens according to this embodiment, will be specifically described.

[0084] Figure 5A is an explanatory diagram showing an example of the main components of an eyeglass lens according to this embodiment. Figure 5B shows a specific example of electron microscope observation results of a cross-section of the AR film 13. The example shows enlarged views of parts A and B in Figure 5A, and displays electron microscope images of the laser-scanned area 16 and the unprocessed area 15.

[0085] As shown in Figure 5A, the spectacle lens according to this embodiment is constructed by sequentially laminating an HC film 12, an AR film 13, and a water-repellent film 14 on the optical surface of a lens substrate 11. The AR film 13 has a multilayer structure in which a low refractive index layer, an SiO2 layer 13a, and high refractive index layers, an SnO2 layer 13b and a ZrO2 layer 13c, are laminated. The structure is configured such that a predetermined layer including the outermost layer, the SiO2 layer 13a (specifically, the SnO2 layer which is a reaction layer, and the layers on the surface side thereof), is partially removed to expose the high refractive index layer, the ZrO2 layer 13c. In other words, the spectacle lens according to this embodiment comprises an unprocessed region 15 in which the optical surface of the lens substrate 11 is covered with an HC film 12, an AR film 13, and a water-repellent film 14, and a laser-scanned region (patterned region) 16 in which the outermost SiO2 layer 13a of the AR film 13, the SnO2 layer 13b directly beneath it, and the water-repellent film 14 are partially removed, exposing a high refractive index layer, the ZrO2 layer 13cb.

[0086] The unprocessed area 15 and the laser-scanned area 16 are covered by an SiO2 layer 13a on one side and exposed by a ZrO2 layer 13c (or, if a portion of the reaction layer remains, the reaction layer which is a high refractive index layer) on the other side. Therefore, the light reflectivity differs in each area depending on the presence or absence of the SiO2 layer 13a. As a result, when the spectacle lens is illuminated with illumination light, the pattern shape formed by the laser-scanned area 16 can be visually observed. In other words, if the laser-scanned area 16 is formed with a pattern shape corresponding to the decorative pattern, that decorative pattern can be visually observed. In this way, the areas where a predetermined layer of the AR film 13 has been removed can be used to constitute the decorative pattern.

[0087] The laser-scanned region 16 that constitutes the decorative pattern is formed by removing the SiO2 layer 13a, which is the outermost layer of the AR film 13, and the SnO2 layer 13b, which is the layer directly beneath it. In other words, the removal is limited to a predetermined layer containing the reaction layer, SnO2. Therefore, it is possible to suppress peeling of each layer of the multilayer structure constituting the AR film 13 due to the formation of the laser-scanned region 16.

[0088] As previously described, the removal of the SiO2 layer 13a, which is the outermost layer of the AR film 13, can be achieved by non-heating processing using irradiation with an ultrashort pulse laser. With this non-heating processing method, the thermal impact on the area surrounding the processing site is minimized, and thermal damage can be suppressed. Furthermore, by applying the predetermined pulse width described above, stable processing can be performed while suppressing damage to the layers below the reaction layer. As a result, the ZrO2 layer 13c, which is a high refractive index layer, is exposed, but damage to the exposed surface of the ZrO2 layer 13c can be suppressed.

[0089] If damage to the exposed surface of the ZrO2 layer 13c can be suppressed, the reduction in film thickness associated with the removal process of the ZrO2 layer 13c can also be suppressed. The film thicknesses of the SiO2 layer 13a, SnO2 layer 13b, ZrO2 layer 13c, etc., can be determined by acquiring electron microscope images of the cross-section of the AR film 13 and analyzing the acquired images.

[0090] Figure 5B shows a specific example of electron microscope observation results of a cross-section of the AR film 13. The example shows enlarged views of parts A and B in Figure 5A, and displays electron microscope images of the laser-scanned region 16 and the unprocessed region 15. In the unprocessed region 15, the SiO2 layer 13a, SnO2 layer 13b, and ZrO2 layer 13c are stacked, but the SnO2 layer 13b is thin (for example, about 5 nm) and therefore difficult to recognize in the image. On the other hand, in the laser-scanned region 16, the SnO2 layer 13b and the SiO2 on the surface side of it have been removed, exposing the ZrO2 layer 13c.

[0091] As shown in the example electron microscope image, it can be seen that in the ZrO2 layer 13c exposed by removing SnO2 and the surface layer therein, there is no significant difference between the thickness t1 of the laser-scanned area 16 and the thickness t2 of the unprocessed area 15. More specifically, the ratio t1 / t2 of the thickness t1 of the removed area to the thickness t2 of the unremoved area is, for example, within the range of 0.90 to 1.00, preferably within the range of 0.95 to 1.00, and more preferably within the range of 0.99 to 1.00.

[0092] Thus, in the exposed high refractive index layer, the ZrO2 layer 13c, there is no reduction in film thickness due to the removal process, or if a reduction occurs, it is suppressed to be extremely small. This is because the laser scan region 16 is formed by non-heating processing by irradiation with an ultrashort pulse laser, and the underlying ZrO2 layer 13c is not damaged. This means that if the thickness ratio t1 / t2 of the exposed ZrO2 layer 13c falls within the above range, the laser scan region 16 is formed without damaging the ZrO2 layer 13c, and it can be inferred that the formation of the laser scan region 16 was carried out using non-heating processing with an ultrashort pulse laser.

[0093] The reason why the ZrO2 layer 13 is not damaged is that the reactivity of the reaction layer (in this case, the SnO2 layer) is higher than that of ZrO2 when using an ultrashort pulse laser. This difference in reactivity can be significantly achieved by applying an ultrashort pulse laser with a predetermined pulse width, as will be described later.

[0094] Furthermore, by ensuring that the thickness of the ZrO2 layer is 10 times or more, preferably 15 times or more, compared to the SnO2 layer, even if the ZrO2 layer is slightly reduced after the SnO2 layer has disappeared, there is no risk of film peeling or impact on the visibility of the decorative pattern.

[0095] Furthermore, the fact that the melting point of SnO2 is lower than that of the SiO2 layer above, and significantly lower than that of the ZrO2 layer below, is also thought to contribute to the ease of controlling ablation.

[0096] With the spectacle lens configured as described above, even if a decorative pattern is marked, peeling of each layer constituting the multilayer AR film 13 can be suppressed, and the exposed ZrO2 layer 13c will not be damaged. Therefore, even when applied to spectacle lens products, it is possible to mark the spectacle lens with a decorative pattern without causing a decrease in the quality of the product.

[0097] The following explains the relationship between differences in pulse width and whether or not marking can be performed on the optical component without degrading its quality. In the following diagrams, the white areas (e.g., dot patterns) are the laser scan areas 16, and the blue (black) areas are the unprocessed areas 15. Hereafter, the process of marking will also be referred to as laser processing.

[0098] (Femtosecond pulse width) Laser processing tests were performed on the AR film 13 in the unprocessed region 15 of the spectacle lens 1 (a double-sided plano lens) shown in Figure 5B, with a pulse width of 100 femtoseconds or more and less than 1 picosecond. During these tests, the laser wavelengths were set to 1064 nm (infrared region, first harmonic) and 532 nm (green region, second harmonic), respectively.

[0099] Figure 6A is a micrograph (magnification 200x) showing the results of a test in which a dot pattern was formed on the AR film 13 of the spectacle lens 1 shown in Figure 5B, using a laser beam with a wavelength of 1064 nm and a pulse width of 100 femtoseconds or more and less than 1 picosecond. Figure 6B is a micrograph (magnification 200x) showing the results of a test in which a dot pattern was formed on the AR film 13 of the spectacle lens 1 shown in Figure 5B, using a laser beam with a wavelength of 532 nm and a pulse width of 100 femtoseconds or more and less than 1 picosecond. The processing diameter by the laser beam is approximately 27 μm.

[0100] As shown in Figures 6A and 6B, when the pulse width was set to 100 femtoseconds or more and less than 1 picosecond, stable removal processing with uniform diameter and depth was achieved. In particular, as shown in Figure 6B, when the wavelength of the laser light was low, it was easier to process small diameters, and the effect was more pronounced.

[0101] (Picosecond pulse width) Laser processing tests were performed on the AR film 13 of the spectacle lens 1 shown in Figure 5B, with a pulse width of several tens of picoseconds. During these tests, the laser light wavelengths were set to 1064 nm (infrared region, first harmonic), 532 nm (green region, second harmonic), and 355 nm (ultraviolet (UV) region, third harmonic), and each test was conducted accordingly. Note that "tens of picoseconds" refers to a value greater than 10 but less than 20.

[0102] Figure 7A is a micrograph (magnification 200x) showing the results of a test in which a dot pattern was formed on the AR film 13 of the spectacle lens 1 shown in Figure 5B, using a laser beam with a wavelength of 1064 nm and a pulse width of several tens of picoseconds. Figure 7B is a micrograph (magnification 200x) showing the results of a test in which a dot pattern was formed on the AR film 13 of the spectacle lens 1 shown in Figure 5B, using a laser beam with a wavelength of 532 nm and a pulse width of several tens of picoseconds. Figure 7C is a micrograph (magnification 200x) showing the results of a test in which a dot pattern was formed on the AR film 13 of the spectacle lens 1 shown in Figure 5B, using a laser beam with a wavelength of 355 nm and a pulse width of several tens of picoseconds.

[0103] As shown in Figures 7A, 7B, and 7C, when the pulse width was set to several tens of picoseconds, a stable depth of removal was achieved, and marking was performed on the optical component. Note that in Figures 7A and 7B, the defocus is set to +3 mm. Normally, a defocus condition of up to ±1 mm is sufficiently applicable. In other words, with this embodiment, marking can be performed on the optical component stably without causing a deterioration in the quality of the optical component, even with focus fluctuations. Note that "Number 10" refers to a value in the range of 20 or greater and less than 90.

[0104] Figure 8A is a micrograph (magnification 200x) showing the results of a test in which the AR film 13 of the spectacle lens 1 shown in Figure 5B was removed without gaps by overlapping dot patterns using a laser beam with a wavelength of 355 nm and a pulse width of several tens of picoseconds. The SnO2 reaction layer and the SiO2 layer on the surface above it were uniformly removed, resulting in a good processing result. Figure 8B is a micrograph (magnification 200x) showing the results of a test in which the AR film 13 of the spectacle lens 1 shown in Figure 5B was subjected to gapless removal processing by overlapping dot patterns using a laser beam with a wavelength of 532 nm and a pulse width of several tens of picoseconds.

[0105] As shown in Figures 8A and 8B, marking was possible on the optical component when the pulse width was set to several tens of picoseconds or several tens of picoseconds. In particular, in Figure 8B, localized damage occurred on the lower layer of the SnO2 layer, but as shown in Figure 8A, uniform removal was possible when the pulse width was several tens of picoseconds.

[0106] (Pulse width in nanoseconds) Laser processing tests were performed on the AR film 13 of the spectacle lens 1 shown in Figure 5B, with a pulse width of several tens of nanoseconds. During these tests, the laser wavelength was set to 355 nm (ultraviolet (UV) region, third harmonic) and 266 nm (deep ultraviolet (DUV) region, fourth harmonic), respectively.

[0107] Figure 9A is a micrograph (magnification 50x) showing the results of a test in which a dot pattern was formed on the AR film 13 of the spectacle lens 1 shown in Figure 5B, using a laser beam with a wavelength of 355 nm and a pulse width of several tens of nanoseconds. Figure 9B is a micrograph showing the results of a test in which a dot pattern was formed on the AR film 13 of the spectacle lens 1 shown in Figure 5B, using a laser beam with a wavelength of 266 nm and a pulse width of several tens of nanoseconds (magnification 50x on the left and 500x for the four images on the right).

[0108] As shown in Figure 9A, when the pulse width was set to several tens of nanoseconds, processing could not be performed at low laser power. When the laser power was increased to a level where processing was possible, damage occurred to the underlying ZrO2 layer.

[0109] Due to unstable processing conditions and damage to the underlying layer, the decorative pattern may be visible to the wearer of the eyeglass lens 1 compared to the eyeglass lens 1 of this embodiment, potentially obstructing their vision and impairing the functionality of the eyeglasses. Furthermore, the processed area is more prone to peeling compared to the eyeglass lens 1 of this embodiment, and its weather resistance and chemical resistance may also deteriorate.

[0110] As shown in Figure 9B, although processing could be performed by changing the laser beam's focus, there was significant unevenness in the processing, and depending on the focus, damage occurred to the lower layers than expected. It was difficult to process uniformly and stably to the desired depth.

[0111] According to this embodiment, one or more of the following effects can be obtained.

[0112] (a) In this embodiment, the reaction layer (SnO2 in the above embodiment) and the surface layer of the AR film 13, which is one of the thin films covering the optical surface of the lens substrate 11, are partially removed, thereby exposing the ZrO2 layer 13c, which is a high refractive index layer, and a decorative pattern is marked on the eyeglass lens.

[0113] (b) In this embodiment, non-heating processing is performed by irradiation with an ultrashort pulse laser to partially remove the reaction layer (SnO2 in the above embodiment) of the AR film 13 and the layers on the surface thereto, thereby exposing the ZrO2 layer 13c, which is a high refractive index layer, and marking a decorative pattern on the eyeglass lens. With this non-heating processing, the removal process is performed by the effect of the pulse width rather than the absorption energy effect of the laser light, so it is possible to selectively and uniformly remove only the predetermined layer, including the SiO2 layer 13a, which is the outermost layer of the AR film 13. Moreover, because it is a non-heating process, it is possible to suppress thermal damage around the processing area, thereby suppressing damage to the exposed surface of the ZrO2 layer 13c located below the reaction layer.

[0114] (c) As described above, in this embodiment, a decorative pattern is marked on the eyeglass lens by removing a predetermined layer including the outermost layer of the AR film 13 using an ultrashort pulse laser and exposing the high refractive index layer. Therefore, according to this embodiment, peeling of each layer of the AR film 13 can be suppressed, and no damage occurs to the exposed ZrO2 layer 13c. Thus, even when applied to eyeglass lens products, it is possible to mark decorative patterns on eyeglass lenses without causing a decrease in the quality of the product.

[0115] (d) In this embodiment, the pulse width of the ultrashort pulse laser may be greater than 0 femtoseconds, but is preferably 0.01 picoseconds (10 femtoseconds) or more and less than 100 picoseconds. Using a pulse width of 0.1 picoseconds or more (including 1 picosecond or more) is advantageous in terms of equipment maintenance and cost, and is more suitable for commercial use. More specifically, the following advantages exist depending on the pulse width when considering laser irradiation conditions. (1) When the pulse width of the ultrashort pulse laser is less than 0.1 picoseconds Good processing can be performed at any wavelength between 266 and 1064 nm. Shorter wavelengths are more advantageous for microfabrication. However, this increases the production burden in terms of equipment maintenance and cost. (2) When the pulse width of the ultrashort pulse laser is 0.1 picoseconds or more and less than 1 picosecond Good processing can be performed at any wavelength between 266 and 1064 nm. Shorter wavelengths are more advantageous for microfabrication. (3) When the pulse width of the ultrashort pulse laser is 1 picosecond or more and less than 100 picoseconds Good processing can be performed at any wavelength between 266 and 1064 nm. Shorter wavelengths are more advantageous for microfabrication. It is suitable in terms of equipment maintenance, cost, and stability of production conditions.

[0116] (e) In this embodiment, when performing non-heating processing by irradiation with an ultrashort pulse laser, the irradiation of the AR film 13 with the ultrashort pulse laser is performed with a defocus setting. By irradiating with laser light with such a defocus setting, the beam energy can be dispersed on the surface of the AR film 13 to which the laser light is irradiated, thereby enabling uniform film removal processing. This is particularly useful when the height of the irradiated area may vary due to the surface shape of the AR film 13.

[0117] (f) In this embodiment, since non-heating processing is performed by irradiation with an ultrashort pulse laser under predetermined conditions, damage to the exposed surface of the ZrO2 layer 13c, which is a high refractive index layer that will be exposed by the removal of SnO2 and the layers on the surface thereof, can be suppressed. Specifically, the ratio t1 / t2 of the thickness t1 of the ZrO2 layer 13c at the removal location and the thickness t2 of the ZrO2 layer 13c at the non-removed location such as the SiO2 layer 13a will be, for example, in the range of 0.90 to 1.00, preferably in the range of 0.95 to 1.00, and more preferably in the range of 0.99 to 1.00. In this way, in the ZrO2 layer 13c, there is no reduction in film thickness due to the above removal processing, or if there is a reduction, the amount of reduction is suppressed to be extremely small. Therefore, when applied to eyeglass lens products, it is very preferable for marking decorative patterns on eyeglass lenses without causing a decrease in the quality of the product.

[0118] (5) Variations etc. While embodiments of the present invention have been described above, the disclosures described above represent exemplary embodiments of the present invention. That is, the technical scope of the present invention is not limited to the exemplary embodiments described above, and various modifications are possible without departing from the spirit of the invention.

[0119] In the embodiments described above, the case where the optical element is an eyeglass lens was given as an example, but the present invention is not limited to this. In other words, it can be applied in exactly the same way to optical elements other than eyeglass lenses.

[0120] In the embodiments described above, an example was given of marking decorative patterns by non-heating processing using an ultrashort pulse laser, but the present invention is not limited to this. In other words, non-heating processing using an ultrashort pulse laser can be used for any purpose of patterning the optical surface of an optical component, and can be applied in exactly the same way to purposes other than marking decorative patterns.

[0121] In the above-described embodiment, the outermost layer of the AR film 13 is an SiO2 layer 13a as a low refractive index layer, the layer below the SiO2 layer 13a is a SnO2 layer 13b as a reaction layer that is a high refractive index layer, and further below is a ZrO2 layer 13c as a high refractive index layer. In this example, when the SnO2 reacts and is partially removed by laser irradiation, the SiO2 is also removed, thereby exposing the ZrO2 layer 13c as a high refractive index layer. However, the present invention is not limited to this example. The AR film 13 may be composed of layers other than the SiO2 layer 13a, SnO2 layer 13b, and ZrO2 layer 13c stacked together. Furthermore, the outermost layer of the AR film 13 may be a low refractive index layer other than the SiO2 layer 13a. The high refractive index layer may be a high refractive index layer other than the SnO2 layer 13b or the ZrO2 layer 13c. For example, the SnO2 layer 13b, which serves as the reaction layer, may be replaced with a thin, conductive ITO layer.

[0122] In the above-described embodiment, an example is given in which the SnO2 layer, which is a reaction layer contained in the AR film 13, and the SiO2 layer 13a, which is the outermost layer directly above it, are removed by non-heating processing using an ultrashort pulse laser. As a result, as previously described, the effect of suppressing film peeling is achieved. Thus, non-heating processing using an ultrashort pulse laser can be performed to remove a predetermined number of layers, including the outermost layer. Even when removing multiple layers, including the outermost layer, non-heating processing using an ultrashort pulse laser can suppress damage to the exposed surface of the layers that will be exposed by the removal, and thus the reduction in film thickness associated with the removal process can also be suppressed. In other words, even when removing multiple layers, including the outermost layer, the ratio t1 / t2 of the thickness t1 of the removed area to the thickness t2 of the unremoved area of ​​the layer directly below the removed layer will be, for example, in the range of 0.90 to 1.00, preferably in the range of 0.95 to 1.00, and more preferably in the range of 0.99 to 1.00. This means that this disclosure includes the following inventive concept. In other words, according to this disclosure, Optical substrate for forming an optical surface, The optical substrate comprises an anti-reflective coating that covers the optical surface, The anti-reflective film has a multilayer structure, and is configured such that at least one layer constituting the multilayer structure is partially removed. The layer directly beneath the at least one layer is configured such that the ratio t1 / t2 of the thickness t1 of the removed portion of the at least one layer to the thickness t2 of the unremoved portion of the at least one layer falls within the range of 0.90 to 1.00. Optical components.

[0123] In this embodiment, the spectacle lens before laser processing may have an anti-reflective coating on both sides. One specific example of such spectacle lens is described in International Publication No. WO2020 / 067407. The contents of that publication can be fully referenced in this specification. In particular, the spectacle lens with the configurations of Examples 1 and 2 described in that publication (if only one is chosen, then Example 1) may be adopted as a specific example. One specific example of the spectacle lens before decoration in this embodiment is as follows.

[0124] One specific example is eyeglass lenses. An eyeglass lens having a multilayer coating on both sides of the lens substrate, The sum of the average reflectances in the 360-400 nm wavelength range across each surface of the aforementioned spectacle lens is 6.0% or less. The sum of the average reflectances in the 400-440 nm wavelength range across each surface of the aforementioned spectacle lens is 20.0% or more. The sum of the average reflectances in the 480-680 nm wavelength range across each surface of the aforementioned spectacle lens is 2.0% or less.

[0125] In other words, in the blue light region, particularly in the violet region (400-440 nm) which should be blocked, the sum of the average reflectances of each surface should be 20.0% or more (preferably exceeding 20.0%, and even more preferably 25.0% or more). That is, the reflectance is locally increased in the aforementioned violet region.

[0126] Instead, in the ultraviolet or violet region at lower wavelengths (360-400 nm), the sum of the average reflectances of each surface is set to 6.0% or less (preferably less than 6.0%, and even more preferably 5.0% or less), thus locally reducing the reflectance, the opposite to the case in the violet region (400-440 nm).

[0127] Furthermore, in the higher wavelength range of the blue wavelength region or the red region (480-680 nm), the sum of the average reflectances of each surface is set to 2.0% or less (preferably less than 2.0%, and even more preferably 1.5% or less), and in order to aim for the transmission of visible light, the reflectance is reduced locally, especially in the main wavelength band of visible light.

[0128] In this specific example, it is possible to ensure the blocking effect against light in the blue region while also ensuring the transmission of visible light.

[0129] When laser processing according to this embodiment is performed on this specific example of eyeglass lens, the following advantageous effects are obtained. This specific example of eyeglass lens ensures a blocking effect against blue light, that is, it has a high reflectivity of blue light. Therefore, when a third party facing the wearer of eyeglass lens 1 views the eyeglass lens 1, the eyeglass lens appears blue. On the other hand, the area where laser processing has been performed (decorative pattern 3) appears in the color of the layer exposed by the laser processing (in this specific example, the color of the ZrO2 layer, which is yellow or gold). As a result, to a third party facing the wearer of eyeglass lens 1, the decorative pattern 3 appears to stand out against a blue background on the eyeglass lens 1 fitted into the frame. In this case, a decorative pattern 3 with a high design effect can be obtained. This is also true when the background is not blue, that is, when the reflectivity of light in a region other than the blue region is high. An example of a background color is when the eyeglass lens 1 is viewed by a third party facing the wearer of eyeglass lens 1, and the eyeglass lens 1 appears green or pearlescent.

[0130] The good contrast characteristics of the decorative pattern 3 described above can be achieved whether the laser processing is applied to each multilayer film on the object-facing side of the spectacle lens or to each multilayer film on the eye-facing side.

[0131] Furthermore, regardless of which surface the laser processing is applied to, there is virtually no interference with the wearer's field of vision due to the decorative pattern entering their field of view. In other words, eyeglass lenses with the decorative pattern 3 of this embodiment do not obstruct the wearer's clear vision.

[0132] Furthermore, when observing the wearer's lenses from another person's perspective, the decorative pattern 3 is clearly visible when the wearer's lenses are at a predetermined relative position (or angle) with respect to indoor lighting or sunlight. However, it becomes difficult to see when the lenses are not at the aforementioned relative position. Therefore, the lens can be given added design value through changes in visibility, such as the predetermined decorative pattern 3 becoming clearly visible or almost disappearing. On the other hand, when the lenses are not in the predetermined relative positional relationship described above, they will be perceived by others as ordinary clear lenses (or predetermined colored lenses, photochromic lenses, or polarized lenses).

[0133] Even when the decorative pattern 3 of this embodiment is formed within the frame-cut lens area, it does not affect the function of the eyeglasses, and allows desired letters, symbols, or patterns to be placed on the lens, or a desired design to be applied to the lens.

[0134] The decorative pattern 3 in this embodiment is a process that can be seen from both the processed surface side and the back side of the lens. This is because, in a multilayer anti-reflective coating, the anti-reflective properties of the designed coating are reduced in the areas where a portion has been removed (in this embodiment, SnO2 and the SiO2 on the upper layer have been removed), and a contrast in the amount of reflected light is obtained between these areas and the areas where the coating has not been removed.

[0135] Therefore, the technical concept of the present invention also extends to eyeglass lenses, which are optical components manufactured by the manufacturing method of the optical component according to this embodiment, or to eyeglasses in which eyeglass lenses, which are optical components according to this embodiment, are fitted into a frame. [Explanation of symbols]

[0136] 1…Eyeglass lens (optical component), 2…Frame shape, 3…Decorative pattern, 4…Scannable range, 11…Lens substrate (optical substrate), 12…HC film, 13…AR film, 13a…SiO2 layer (low refractive index layer), 13b…SnO2 layer (high refractive index layer), 13c…ZrO2 layer (high refractive index layer), 14…Water-repellent film, 15…Unprocessed area, 16…Laser scan area (patterned area), 21…Laser light source unit, 22…AOM system unit, 23…Beam shaper unit, 24…Galvanometer scanner unit, 25…Optical system

Claims

1. A method for manufacturing an optical component, comprising irradiating an anti-reflective film having a multilayer structure including a stack of low-refractive-index layers and high-refractive-index layers, formed to cover the optical surface of an optical substrate, with an ultrashort pulse laser, and partially removing a predetermined layer including the outermost layer of the multilayer structure to perform desired laser processing, The aforementioned ultrashort pulse laser has a pulse width of 10 femtoseconds or more and less than 100 picoseconds. The anti-reflective film includes the high refractive index layer, which is a reaction layer that is relatively more reactive to irradiation with the ultrashort pulse laser than the other layers included in the multilayer structure. The anti-reflective film's multilayer structure is constructed by laminating the low refractive index layer, the reaction layer, and the high refractive index layer in that order, starting from the outermost layer. By the irradiation, the reaction layer is removed at least partially, thereby performing the laser processing that is visible in visible light. A method for manufacturing an optical member, wherein, in removing the reaction layer, the reaction layer disappears by sublimation or evaporation at least partially in the thickness direction, and as a result of the disappearance, other layers laminated above the reaction layer are removed.

2. The method for manufacturing an optical member according to Claim 1, wherein the low refractive index layer, the reaction layer, and the high refractive index layer are laminated in order from the outermost layer of the multilayer structure of the anti-reflective film.

3. A method for manufacturing an optical member according to claim 1 or 2, wherein, in the irradiated area where the reaction layer is removed by the irradiation, a high refractive index layer included in the multilayer structure is exposed.

4. The method for manufacturing an optical member according to any one of claims 1 to 3, wherein the reaction layer is a conductive layer with higher conductivity than the other layers constituting the multilayer structure.

5. The method for manufacturing an optical member according to any one of claims 1 to 4, wherein the reaction layer comprises Sn and O.

6. The method for manufacturing an optical member according to any one of claims 1 to 5, wherein the optical member is an eyeglass lens.

7. The method for manufacturing an optical member according to any one of claims 1 to 6, wherein the ultrashort pulse laser has a pulse width of 0.1 picoseconds or more and less than 50 picoseconds.

Images