Method for manufacturing vacuum blocking components and eyeglass lenses

Abstract

A vacuum blocking component for vacuum blocking a lens blank is provided. The vacuum blocking component includes a support element having an upper portion and a lower portion, and the lower portion is configured to engage with a clamping device for clamping the vacuum blocking component. The vacuum blocking component further includes a fluid-permeable blank contact element, the blank contact element is fluid-permeable, and at least the upper surface of the blank contact element configured to contact the lens blank is made of an elastic material, and the blank contact element further has a lower surface (24) for contacting the upper portion of the support element. The vacuum blocking component is configured to fix the lens blank to the upper surface of the blank contact element by applying a vacuum within the blocking component to provide adsorption through essentially the entire upper surface of the blank contact element, thereby adsorbing the lens blank to the upper surface of the blank contact element and adsorbing the blank contact element to the upper surface of the support element.

Description

Technology Field

[0001] A method for manufacturing a blank contact element, a vacuum blocking component, and an spectacle lens is provided. Accordingly, the present disclosure relates to the manufacture of an spectacle lens.

[0002] Accordingly, the embodiments relate to a system, apparatus, and method for blocking a lens blank and manufacturing an ophthalmic lens, in particular, an eyeglass lens. Background Technology

[0003] For the industrial mass production of spectacle lenses made of plastic materials or mineral glass, particularly those with freeform surfaces, lens blanks are blocked by a blocking component using a device called a blocking device, which is separate from the processing device that grinds or cuts the lens blanks. Blocking the lens blanks is necessary to mechanically and elastically secure the lens blanks in a designated position and to continue the milling or grinding process to individualize the refractive power of the lens blanks. The blocking component through which the lens blanks are blocked enables the lens blanks to be clamped to the grinding or cutting machine in a shape-fit and / or force-fit manner.

[0004] According to the prior art, a lens blank is attached to a blocking component using a metal alloy with a low melting temperature. The lens blank is positioned relative to the blocking component such that the finished front surface of the lens blank faces the blocking component, wherein the surface normal of the lens blank and the surface normal of the blocking component are positioned at a predetermined angle relative to each other, and the space between the blocking component and the front surface of the lens blank is filled with a liquid metal alloy. Subsequently, the blocking component is cooled by a cooling device integrated into the blocking device to harden the metal alloy and secure the lens blank to the blocking component. This blocking method can be performed manually or in an automated manner. After the metal alloy is hardened, the blocking component and the lens blank attached thereto can be removed from the blocking device.

[0005] After the blocking step, the following manufacturing steps are typically performed on the blocked lens blank: cutting the margin contour of the spectacle lens, milling the intended refractive power on the back surface of the lens blank, polishing the milled surface by a polishing device into which the blocked lens blank is inserted, and applying a signature mark to the optical surface to enable precise positioning of the optical surface.

[0006] Finally, the finished eyeglass lenses are removed from the blocking components. If a metal alloy is used for blocking, the metal alloy is heated and melted, then undergoes a recycling process.

[0007] Using metal alloys for lens blank blocking causes environmental disadvantages. To address this problem, there have been attempts to avoid using metal alloys for lens blank blocking for environmental reasons. DE 102005038063 A1 describes an alternative blocking method that suggests using polymer adhesives or thermoplastic materials that can be cured by light irradiation.

[0008] When polymeric or thermoplastic materials are used for blocking, reusing the blocking material after unlocking is often not economical due to contamination of the material during the manufacturing process and mechanical and / or chemical changes in the material over time.

[0009] An alternative approach for blocking a lens blank proposed in the prior art is described in EP 2266754 B1. This proposed method uses a blocking component having a support surface including a ring-shaped recess to fix the lens blank to the support surface via a vacuum. However, this approach often results in unwanted deformation of the lens blank due to the recess.

[0010] JP H03121763A describes a vacuum adapter having several interlocking cylindrical parts. DE 2531134A1 discloses a vacuum adapter in which a lens is contacted by a flexible sealing ring. US 3134208A discloses a vacuum adapter having a circular recess that can be evacuated. Other vacuum adapters are described in US 4089102A and DE 3924078A1.

[0011] An alternative approach for blocking a lens blank known in the prior art is vacuum blocking as described in EP 4035832A1, which is considered the most similar prior art. This technology uses a vacuum blocking component having a lower portion corresponding to the lower portion of another conventional blocking component configured to be mountable on a conventional machine for mechanically processing the rear surface of a lens blank.

[0012] US 6,126,520 describes a fixture and method for joining optical components to a machine using a vacuum. US 2015 / 0217420Al describes a processing machine having a lens holding device for holding a presbyopic lens in a processing machine, wherein the presbyopic lens is held on the holding device by an adhesive element. DE 2531134 A1 describes a device for processing an spectacle lens, wherein the lens holder includes an elastically deformable sleeve connecting the outer edge of a shell to the outer edge of a support collar.

[0013] The upper portion of a conventional vacuum sealing component comprises an element made of a rigid yet porous material, such as ceramic, which is designed to accommodate a lens blank. This element, whose diameter and curvature match the convex surface of the lens blank to be vacuum sealed, is hermetically embedded in a cylindrical support element and is firmly joined to and / or screwed to the support element. An air valve on the lower side of the adapter applies a vacuum to significantly exhaust the air volume from the porous material / ceramic, thereby allowing the lens blank to be firmly adsorbed onto the surface of the element. To securely seal the exhaust area to the outside, a cylindrical sealing lip made of rubber may be provided on the outer edge of the upper portion. The adhesion force required between the surface of the lens blank and the vacuum adapter to transmit the forces and torques generated during the mechanical processing of the lens blank is approximately 8.0 N / cm² on the lens blank. 2 Up to 8.5 N / cm 2 This is achieved by a combination of atmospheric contact pressure and the adhesive force between the protective film bonded to the surface of the lens blank and the elements of the vacuum blocking component. To release the connection between the lens blank and the vacuum blocking component, the vacuum can be released by ventilating the inside of the vacuum blocking component through an air valve.

[0014] In conventional vacuum blocking processes, the existing final face of the lens blank facing the blocking component during blocking is covered with a suitable protective film or varnish prior to blocking to protect the face of the lens blank from damage caused by contact with the blocking component during processing. Additionally, the protective film or varnish may be required in conventional blocking technology to provide sufficient adhesion between the lens blank and the blocking component through effects such as adhesives or micro-serrations, thereby providing a mechanical connection between the lens blank and the blocking component that is elastic against the forces and moments generated during mechanical processing.

[0015] Considering EP 4035832A1, the most similar prior art, the technical problem of the claim may be related to providing an improved vacuum-blocking component and an improved method for manufacturing spectacle lenses, and optionally to providing an improved vacuum-blocking component and an improved method for manufacturing spectacle lenses that increases environmental sustainability and reduces the manufacturing cost of spectacle lenses.

[0016] These problems are solved by a blank contact element, a vacuum blocking component, and a method having the features of each independent claim. Optional embodiments are provided in the dependent claims and the description of the invention.

[0017] In a first embodiment, a blank contact element is provided that is configured to be used with a vacuum blocking component suitable for vacuum blocking a lens blank, wherein the blank contact element is fluid-permeable and at least the upper surface of the blank contact element configured to contact the lens blank is made of an elastic material.

[0018] In another embodiment, a vacuum blocking component for vacuum blocking a lens blank is provided. The vacuum blocking component includes a support element having an upper portion and a lower portion, and the lower portion is configured to engage with a clamping device for clamping the vacuum blocking component. The vacuum blocking component further includes a fluid-permeable blank contact element, the blank contact element is fluid-permeable, and at least the upper surface of the blank contact element configured to contact the lens blank is made of an elastic material, and the blank contact element further has a lower surface (24) for contacting the upper portion of the support element. The vacuum blocking component is configured to fix the lens blank to the upper surface of the blank contact element by applying a vacuum within the blocking component to provide adsorption through essentially the entire upper surface of the blank contact element, thereby adsorbing the lens blank to the upper surface of the blank contact element and adsorbing the blank contact element to the upper surface of the support element.

[0019] In another embodiment, a vacuum blocking member for vacuum blocking a lens blank is provided. The vacuum blocking member comprises a support element having an upper portion and a lower portion, and the lower portion is configured to engage with a clamping device for clamping the vacuum blocking member. The vacuum blocking member further comprises a fluid-permeable blank contact element, the blank contact element is fluid-permeable, and at least the upper surface of the blank contact element configured to contact the lens blank is made of an elastic material, and the blank contact element further comprises a lower surface for contacting the upper portion of the support element. The vacuum blocking member is configured to fix the lens blank to the upper surface of the blank contact element by applying a vacuum within the blocking member to provide adsorption through essentially the entire upper surface of the blank contact element, thereby adsorbing the lens blank to the upper surface of the blank contact element and adsorbing the blank contact element to the upper portion of the support element. The upper portion of the support element is configured to support the fluid-permeable blank contact element and is formed of a rigid fluid-permeable material.

[0020] In another embodiment, a vacuum blocking member for vacuum blocking a lens blank is provided. The vacuum blocking member comprises a support element having an upper portion and a lower portion, and the lower portion is configured to engage with a clamping device for clamping the vacuum blocking member. The vacuum blocking member further comprises a fluid-permeable blank contact element according to the present disclosure, and the blank contact element further comprises a lower surface for contacting the upper portion of the support element. The blocking member is configured to fix the lens blank to the upper surface of the blank contact element by applying a vacuum within the blocking member to provide adsorption through essentially the entire upper surface of the blank contact element, thereby adsorbing the lens blank to the upper surface of the blank contact element and adsorbing the blank contact element to the upper surface of the support element.

[0021] In another aspect, a method for manufacturing an eyeglass lens is provided. The method comprises the step of providing a vacuum blocking component for vacuum blocking a lens blank, wherein the vacuum blocking component comprises a fluid-permeable blank contact element having an upper surface configured to contact the lens blank, and at least the upper surface of the fluid-permeable blank contact element is made of an elastic material, and the vacuum blocking component comprises a support element having an upper portion and a lower portion, wherein the lower portion is configured to engage with a clamping device for clamping the blocking component, and the upper portion supports the fluid-permeable blank contact element. The method further comprises the step of placing the lens blank on the upper surface of the blank contact element such that the front surface of the lens blank completely covers the upper surface. Additionally, the method comprises the step of applying a vacuum within the vacuum blocking component to provide adsorption through the fluid-permeable elastic blank contact element so as to adsorb the front surface of the lens blank onto the entire upper surface of the fluid-permeable elastic blank contact element, and the step of mechanically processing at least a portion of the rear surface of the lens blank while the front surface of the lens blank is vacuum-blocked by the vacuum blocking component.

[0022] In another aspect, a method for manufacturing an eyeglass lens is provided. The method comprises the step of providing a vacuum blocking member according to the present disclosure. The method further comprises the step of placing a lens blank on the upper surface of a blank contact element such that the front surface of the lens blank completely covers the upper surface. The method further comprises the step of applying a vacuum within the vacuum blocking member to provide adsorption through a fluid-permeable elastic blank contact element to adsorb the front surface of the lens blank onto the entire upper surface of the fluid-permeable elastic blank contact element, and the step of mechanically processing at least a portion of the rear surface of the lens blank while the front surface of the lens blank is vacuum-blocked in the vacuum blocking member.

[0023] In another aspect, the present disclosure relates to the use of a blank contact element according to the present disclosure to provide an interface between a vacuum blocking component and a lens blank.

[0024] A lens blank may relate to an untreated precursor of an spectacle lens, for example, a lens blank having an untreated front surface and an untreated back surface. The lens blank may be provided in a molding process. However, the lens blank may also relate to a partially treated precursor of an spectacle lens. For example, the front surface of the lens blank may be partially or completely treated and may be covered with a protective foil or coating. As generally understood and defined in Section 3.8.1 of ISO 13666:2019 (E), a lens blank may be a part of an optical material having a single surface that is optically finished to manufacture a lens.

[0025] As generally understood and defined in Section 3.5.2 of ISO 13666:2019(E), spectacle lenses may be ophthalmic lenses that are worn in front of the eyeball but do not come into contact with the eyeball, in accordance with Section 3.5.1 of ISO 13666:2019(E).

[0026] A blocking component relates to an adapter component for mounting a lens blank to a processing device, in particular, a processing device that processes and / or grinds and / or cuts and / or polishes the back surface of the lens blank according to prescription data and edges an spectacle lens according to provided edging data. In one aspect, the blocking component is configured to contact the lens blank, and in the other aspect, the blocking component is configured to engage with a processing device for processing the lens blank. The blocking component is configured to enable reversible blocking of the lens blank, and the blocked lens blank can be unblocked in a manner that maintains the integrity of the lens blank, in particular the front surface of the lens blank, and such front surface may optionally be protected by a protective foil or coating. The blocking component may be a block as generally understood and defined in DIN 58766 (2017). A vacuum blocking component relates to a blocking component that uses vacuum force, that is, pressure resulting from adsorption within the vacuum blocking component to secure the lens blank to the vacuum blocking component, primarily or entirely, as described in, for example, EP 4035832A1. Accordingly, vacuum sealing a lens blank means securing the lens blank to the sealing part by using vacuum force, primarily or entirely, that is, pressure resulting from adsorption within the vacuum sealing part.

[0027] The fact that the blank contact element is fluid-permeable means that fluid flow of gases, particularly airflow, can be generated through the blank contact element. In particular, adsorption can be generated through the blank contact element by applying a pressure difference between the outside and inside of the blocking component.

[0028] Elastic materials should be understood as materials possessing elastic mechanical properties. Therefore, elastic materials can allow mechanical deformation when a mechanical force is applied to the material, and the deformation is at least partially reversible. After the applied mechanical force is removed, the elastic material can return to its initial shape at least partially.

[0029] It should be understood that at least the upper surface of the blank contact element is made of an elastic material, meaning that the surface configured to contact the lens blank at least when blocking the lens blank is made of an elastic material. Optionally, the entire blank contact element may be made of an elastic material. The blank contact element may be made as a single part of an elastic material.

[0030] The blank contact element may be provided as a separate component from the vacuum blocking component. However, according to some optional embodiments, the blank contact element may form an integral part of the vacuum blocking component. That the blank contact element is configured to be used with the vacuum blocking component means that the blank contact element and the vacuum blocking component may be provided as an assembly for vacuum blocking a lens blank. The blank contact element may provide an interface between the lens blank and the vacuum blocking component when blocking the lens blank.

[0031] Adsorption through the "essentially the entire top surface" of the blank contact element means that adsorption and the airflow that may result from adsorption are not limited to a specific partial area of ​​the top surface of the blank contact element, such as a recess or hole formed only in a part of the top surface of the blank contact element. Instead, "essentially the entire top surface" means that adsorption is provided over most of the top surface, particularly over an area exceeding 90% of the accessible portion of the top surface, preferably over the entire accessible top surface. That a part of the top surface is accessible means that the part of the top surface is accessible so as to be contacted by the lens blank without being covered. This can be achieved by providing a porous elastic material and / or providing holes distributed over the entire top surface of the blank contact element.

[0032] The term "vacuum" relates to pressures much lower than ambient atmospheric pressure. However, in this sense, a vacuum does not require a state of being completely devoid of matter, as can be inferred from the strict scientific definition. Instead, pressures reduced by at least 0.3 bar, optionally at least 0.5 bar, optionally at least 0.7 bar, and optionally at least 0.8 bar relative to atmospheric pressure (i.e., total pressures of 0.7 bar, 0.5 bar, 0.3 bar, and 0.2 bar, respectively) are considered a vacuum within the meaning of this description.

[0033] The present disclosure provides the advantage that the interface between the blank contact element and the lens blank, specifically the upper surface of the blank contact element, provides mechanically soft characteristics, thereby preventing damage to the lens blank when vacuum-sealing the lens blank. Due to the elastic characteristics of the upper surface of the blank contact element, the upper surface of the blank contact element is softer than the lens blank, which can prevent mechanical damage, such as scratches, to the lens blank when vacuum-sealing the lens blank. This provides the additional advantage that, since the risk of mechanical damage to the front surface of the lens blank due to contact with the blank contact device is non-existent or negligible, the protection of the front surface of the lens blank in contact with the blank contact element when vacuum-sealing the lens blank can be omitted. Consequently, additional steps of applying and removing a protective device to the lens blank can be omitted, thereby reducing the manufacturing cost of the eyeglass lens. Furthermore, since there is no need to provide or maintain machinery for applying and removing the protective device, further cost reductions can be achieved.

[0034] In addition, the risk of damage to the lens blank can be reduced during the process of applying and / or removing a protective device, such as a protective foil. Conventional processes for applying and / or removing protective foil often apply mechanical stress to the lens blank, which can damage the perimeter of the lens blank's edge. According to the present disclosure, since there is no need to apply and / or remove the protective foil, such damage can be prevented.

[0035] In addition, since the application of a protective coating and / or protective foil to the front of the lens blank can be omitted, the amount of waste generated during the manufacturing of eyeglass lenses can be reduced. This can further improve the environmental sustainability of the eyeglass lens manufacturing process.

[0036] Additionally, the present disclosure may provide the advantage that an elastic material can provide suitable static friction between the blank contact element and the lens blank, and between the blank contact element and the vacuum blocking component, so as to mechanically process the back surface of a blocked lens blank without the need for additional adhesive or fastening. The provided static friction may be suitable for transmitting a torque of up to 12 Nm or even 15 Nm, which may correspond to a typical value achievable by conventional blocking components based on alloy blocking of spectacle lens blanks and thus may be highly suitable for mechanically processing the blocked lens blank. However, optionally, an additional adhesive may also be applied between the blank contact element and the lens blank to increase the transmittable torque. The adhesive may be a two-component adhesive. One or more spots of the adhesive may be applied to the front surface of the lens blank and / or the top surface of the blank contact element.

[0037] In particular, elastic materials can provide much higher static friction than rigid porous materials, such as porous ceramic materials as described in EP 4035832A1.

[0038] The blank contact element can be made entirely of an elastic material. This allows the blank contact element to be formed as a single part made of a single material, thereby facilitating the production of the blank contact element.

[0039] The elastic material may comprise at least one material selected from the group consisting of polyurethane-based materials and rubber-based materials. Optionally, the elastic material may be formed as a foil made of one or more of these materials. Optionally, the polyurethane-based material may comprise or be composed of polyurethane foam. Such materials may provide the advantage of providing a suitable coefficient of friction for the smooth front surface of the lens blank and the upper surface of the support element, and the support element may be made of, for example, ceramic material, SiC, Al2O3, or porous aluminum. Additionally, polyurethane-based materials, such as rubber-based materials and / or polyurethane foil, may provide suitable permeability to allow a fluid, such as air, to apply adsorption to vacuum-block the lens blank through the blank contact element. Additionally, such materials may provide the advantage of having a permanent compression ratio of less than 5% as determined according to ISO 1856:2000. Additionally, such materials have a density of 3 N / mm² as determined according to ISO 1827:2022. 2 It can provide an excess shear modulus. The vacuum blocking component can be configured to provide static friction with a coefficient of friction between the blank contact element and the support element of up to 2.5. This can be achieved at least partially by selecting an elastic material suitable for the blank contact element, e.g., a rubber-based material and / or a polyurethane-based material. The elastic material used can be selected to have a Shore hardness of 50 to 80.

[0040] The elastic modulus of porous polyurethane foil is approximately 3 N / mm 2 to about 10 N / mm 2 It can be a range.

[0041] The blank contact element can be applied to the upper portion of the support element by coating the upper surface of the support element. Alternatively, or additionally, the blank contact element can be pre-manufactured separately from the vacuum blocking component. For example, the blank contact element can be manufactured by a vulcanization process. Additionally, the manufacturing process of the blank contact element may include a step of drilling holes in the vulcanized blank contact element.

[0042] The thickness of the blank contact element may be in the range of 0.3 mm to 0.8 mm. This allows the lens blank to be sufficiently protected from mechanical scratches caused by the vacuum blocking component. In addition, this allows the lens blank to absorb and / or attenuate mechanical shock transmitted from the vacuum blocking component to the lens blank, particularly during the mechanical processing of the lens blank. Furthermore, the blank contact device can absorb and / or attenuate shock applied to the lens blank and prevent the lens blank from being compromised due to the shock.

[0043] The elastic material may be at least partially porous, and the fluid permeability of the blank contact element is caused at least partially by the porosity of the elastic material. This can optionally be achieved by forming the blank contact element at least partially from a foam material such as polyurethane foam. The elastic material may have open pores that allow fluid flow through the porous material. The fluid flow passing through these pores can be used to provide adsorption that induces pressure to secure the lens blank to the blank contact element and to secure the blank contact element to the blocking part during the blocking process. This ensures an even distribution of fluid flow over the entire surface of the blank contact element.

[0044] Alternatively or additionally, the fluid permeability of the blank contact element is caused at least partially by one or more holes formed in the blank contact element. The blank contact element may include a number of holes distributed on the upper surface of the blank contact element. The holes may be through holes extending along the entire thickness of the blank contact element. The through holes may extend in a straight line through the blank contact element, that is, along the direction of the pressure acting on the lens blank to secure the lens blank to the blank contact element. Alternatively or additionally, one or more holes may extend in a non-straight line through the blank contact element. This allows for the use of an elastic material that is non-porous and therefore fluid-permeable. Furthermore, this enables the fluid permeability of the blank contact element to be controlled by adjusting the number and size of the holes provided in the blank contact element.

[0045] Optionally, the blank contact element can be made of a porous material and may have one or more holes. This allows the fluid permeability of the blank contact element to be achieved partly by the porosity of the elastic material and partly by the one or more holes. This enables the combination of the advantages of the two approaches presented above.

[0046] The shape and size of the upper surface of the blank contact element correspond to the shape and size of the lens blank to be blocked. This allows the blank contact element and the blocked lens blank to be placed in the same plane. This coplanar placement can reduce the risk of mechanical impact on the blank contact element outside the portion of the upper surface in contact with the lens blank; otherwise, there is a risk that the vacuum seal formed between the lens blank and the blocked blank contact element will be broken, causing the blocked lens blank to be unintentionally separated. Alternatively, if a sealing lip is provided, the size and / or shape of the sealing lip can be adjusted to match the size and / or shape of the lens blank. For example, the difference in diameter between the blank contact element and / or sealing lip relative to the lens blank can optionally be a deviation of 0.5 mm or less. This can facilitate the process of mechanically processing the edges of the lens blank.

[0047] The blank contact element may further include a sealing lip positioned at the periphery of the blank contact element, and the sealing lip is configured to assist in providing a vacuum between the lens blank and the upper surface of the blank contact element within the blocking part. The sealing lip may be advantageous for firmly securing the blank contact element to the curved front surface of the lens blank. Optionally, the sealing lip may provide lower porosity or no porosity at all compared to the inner section of the blank contact element. This may prevent or reduce fluid flow entering the blank contact element from the periphery of the blank contact element when the lens blank is blocked.

[0048] The sealing lip may form an integral part of the blank contact element and / or support element. Alternatively, the sealing lip may be provided as a separate part that does not form part of the blank contact element and support element.

[0049] The sealing lip can be made of a material different from the material of the blank contact element and the material of the support element. This allows the properties of the sealing lip to be controlled independently of the properties of the blank contact element and the support element. The porosity of the sealing lip material may differ from the porosity of the material(s) of the blank contact element and the support element. The sealing lip can be made of a non-porous material. This allows for vacuum sealing at the outer edge between the blank contact element and the blocked lens blank, and increases the vacuum area applied to the blocked lens blank. This increases the area where adsorption force is applied to the blocked lens blank, thereby enhancing blocking stability. Alternatively, or additionally, this can reduce the pressure difference between the ambient pressure and the applied vacuum.

[0050] The sealing lip may extend from the periphery of the blank contact element in the radially outward direction of the vacuum blocking component.

[0051] The sealing lip can be made of an elastic material such as a polyurethane-based material and / or a rubber-based material. This can improve the sealing lip's ability to adjust its shape to fit the front of the blocked lens blank facing the blank contact element.

[0052] The blank contact element may further include a lower surface configured to contact a vacuum blocking component, and the blank contact element may include one or more protrusions extending from the lower surface of the blank contact element. The one or more protrusions may be configured to engage with the blocking component when the blank contact element is mounted on the vacuum blocking component. Accordingly, the upper surface of the support element of the vacuum blocking component may include one or more concave portions, and the blank contact element may include one or more protrusions configured to mechanically engage with one or more concave portions on the upper surface of the support element when the blank contact element is mounted on the support element. This allows for shape matching between the blank contact element and the blocking component, thereby increasing the connection stability between the blank contact element and the vacuum blocking component, particularly during rotational motion occurring when mechanically processing the rear surface of a blocked lens blank. In other words, the upper surfaces of the blank contact element and the support element may be configured to interlock with each other to prevent rotational motion between the blank contact element and the support element. Alternatively, or additionally, the blank contact element and the support element may be configured to mechanically interlock with each other at the outer circumference section of the blank contact element.

[0053] A fluid-permeable blank contact element can be configured to shape-fit the interface of a support element that forms an interface with the blank contact element. This can improve the mechanical stability of an assembly comprising a blocking component, a blank contact element, and ultimately a blocked lens blank by hindering or eliminating relative movement between the blank contact element and the lens blank.

[0054] The upper portion of the support element may be configured to support a fluid-permeable blank contact element and may be formed of a rigid fluid-permeable material. The rigid fluid-permeable material of the support element may include or be composed of one or more of ceramic materials, carbide materials, particularly silicon carbide, oxide materials, particularly aluminum oxide, and aluminum foam. These materials offer the advantage of being inherently open porous or being manufactured to exhibit open porosity. Additionally, these materials offer the advantage of exhibiting high rigidity, thereby providing high stability under pressure. Thus, these materials provide a suitable combination of fluid permeability and mechanical stability, making them suitable for use in blank contact elements. For example, a porous material having a certain level of (open) porosity, typically used in grinding or cutting processes, may be used. For example, such a material may be silicon carbide (referred to as 10C) having an intermediate hardness value ("M") and an intermediate particle size value (60) according to DIN 69100. A support element having an upper portion made of such material can serve as a suitable support for a fluid-permeable blank contact element made of an elastic material, and can particularly adsorb fluid through the blank contact element and the support element to vacuum seal the lens blank.

[0055] The vacuum blocking component may include an adhesive that secures the lower surface of the blank contact element to the upper surface of the support element. This can further increase the securing of the blank contact element to the vacuum blocking component, and thus further increase the stability of the assembly comprising the blank contact element, the vacuum blocking component, and the lens blank blocked therefrom.

[0056] The vacuum sealing component may further include a sealing lip formed separately from the blank contact element. This enables the evacuated area to be firmly sealed to the outside. To this end, a cylindrical sealing lip made of rubber may be provided on the outer edge of the upper portion. Additionally, since the sealing lip can be separated from the blank contact element, mechanical impact applied to the sealing lip may not affect the mechanical contact between the lens blank and the blank contact element.

[0057] The front surface of the lens blank and / or the upper surface of the blank contact element may be plasma treated in a vacuum chamber before blocking the lens blank. Alternatively, or additionally, a polishing step may be applied to the front surface of the lens blank and / or the upper surface of the blank contact element. This may remove contaminants from the surface, increase surface energy, and / or increase the adhesion between the lens blank and the blank contact element.

[0058] The upper surface of the blank contact element may have a concave shape. In other words, the upper surface of the blank contact element may have a hollow portion in the center, and the edge of the blank contact element may have a height higher than the center of the upper surface of the blank contact element. This can facilitate contact with the front of an eyeglass lens blank that may have a convex shape. The concave shape of the blank contact element can be adjusted to fit the convex shape of the lens blank to be blocked by a vacuum blocking component including the blank contact element.

[0059] All features presented in connection with the blank contact element and the present disclosure shall be deemed to be disclosed in the vacuum sealing component and vice versa. All features presented in connection with the blank contact element and / or vacuum sealing component and vice versa shall be deemed to be disclosed in the method for manufacturing an eyeglass lens and vice versa.

[0060] A person skilled in the art understands that the features described above and the features described in the following description and drawings are disclosed in the explicitly disclosed embodiments and combinations, as well as that which are separate features and other technically feasible combinations. Hereinafter, the present disclosure is not limited to the described embodiments, but several optional embodiments and specific examples are described with reference to the drawings for illustrating the present disclosure. Brief explanation of the drawing

[0061] Optional embodiments of the present disclosure will be described below with reference to the drawings. FIGS. 1a through 1e illustrate vacuum blocking components according to various optional embodiments. FIGS. 2A and 2B illustrate schematic diagrams of a blank contact element according to an optional embodiment. FIG. 3 illustrates a schematic diagram of a blank contact element according to another optional embodiment. FIG. 4 illustrates a method for manufacturing eyeglass lenses according to an optional embodiment. In drawings, the same reference numerals are used for corresponding or similar features in different drawings. Specific details for implementing the invention

[0062] FIG. 1a illustrates a vacuum blocking component (10) according to an optional embodiment for vacuum blocking a lens blank (12) (see FIG. 1c). The vacuum blocking component (10) includes a support element (14) having an upper portion (16) and a lower portion (18), and the lower portion (18) is configured to engage with a clamping device for clamping the blocking component (10). The vacuum blocking component (10) includes a fluid-permeable blank contact element (20). The blank contact element is configured to contact the lens blank (12) and includes an upper surface (22) made of an elastic material. Additionally, the blank contact element has a lower surface (24) for contacting the upper portion of the support element (16). The blocking component (10) is configured to apply a vacuum within the vacuum blocking component (10) to provide adsorption through the essentially entire upper surface (22) of the blank contact element (20), thereby adsorbing the lens blank (12) to the upper surface (22) of the blank contact element (20) and adsorbing the blank contact element (20) to the upper part (16) of the support element (14), so as to fix the lens blank (12) to the upper surface (22) of the blank contact element (20).

[0063] The blank contact element (20) may be made entirely of an elastic material. The elastic material may include at least one material selected from the group consisting of polyurethane-based materials and rubber-based materials. The elastic material may be at least partially porous, and the fluid permeability of the blank contact element (20) may be caused at least partially by the porosity of the elastic material.

[0064] The shape and size of the upper surface of the blank contact element (20) can correspond to the shape and size of the lens blank (12) to be selectively blocked.

[0065] The blank contact element (20) and / or the support element (14) of the vacuum blocking part (10) may further include a sealing lip (26) disposed around the periphery of the blank contact element (20), and the sealing lip (26) is configured to assist in providing a vacuum between the inside of the vacuum blocking part (10) and the upper surface (22) of the lens blank (12) and the blank contact element (20). According to the presented embodiment, the sealing lip (26) and the blank contact element (20) are formed as a single part. Additionally, the part forming the blank contact element (20) and the sealing lip (26) may have an extension (28) extending to the outside of the upper part of the support unit and may be clamped to the support element (14) of the vacuum blocking part. This allows the blank contact element (20) and the sealing lip (26) to be fixed to the support element (14) in a very rigid configuration. Optionally, the extension (28) can be clamped between the upper part (16) and the lower part (18) of the support element (14).

[0066] Accordingly, according to the optional embodiment illustrated in FIG. 1a, the sealing lip (26) and the blank contact element are formed together as a single part. However, according to another embodiment, the blank contact element (20) may be formed without the sealing lip (28), and optionally, the sealing lip (28) may be provided separately from the blank contact element (20).

[0067] The operating principle of the vacuum shut-off device (10) can correspond to the operating principle of the vacuum shut-off device described in EP 4035832A1.

[0068] The fluid-permeable blank contact element (20) may be configured to shape-fit the interface of the support element (14) that forms an interface with the blank contact element. The upper portion (16) of the support element (14) may be configured to support the fluid-permeable blank contact element (20) and may be made of a rigid fluid-permeable material.

[0069] The vacuum blocking component (20) may be configured to provide static friction with a friction coefficient of 2.5 or higher between the blank contact element (20) and the support element (14). The vacuum blocking component may include an adhesive that secures the lower surface (24) of the blank contact element (20) to the upper surface of the upper portion (16) of the support element (14). This can further enhance the static friction between the blank contact element (20) and the support element (14).

[0070] FIG. 1b shows a perspective view of a blank contact element (20) attached to a support element (14) of a vacuum blocking component (10). As can be seen in the drawing, the upper surface (22) and the sealing lip (26) of the blank contact element (20) are formed as a single part.

[0071] FIG. 1c shows a schematic diagram of the vacuum blocking component (10) illustrated in FIG. 1a, in which a lens blank (12) is vacuum-blocked in the vacuum blocking component. The sealing lip (26) may have a diameter of 69 mm, and the lens blank (12) may have a diameter of 70 mm.

[0072] FIG. 1d is a perspective view of a vacuum-sealed lens blank (12) in a vacuum-sealed device according to an optional embodiment of FIG. 1b.

[0073] FIG. 1e illustrates a perspective view of a vacuum shut-off device (10) having a blank contact element (20) and a sealing lip (26) attached thereto. The sealing lip (26) is provided separately from the blank contact element (20).

[0074] FIG. 2a schematically illustrates a blank contact element (20) having a plurality of holes (30) marked with dots in a plan view, wherein the holes are provided penetrating the upper surface and the entire thickness of the blank contact element (20). The holes may be distributed over the entire upper surface of the blank contact element and may achieve a homogeneous fluid flow through the upper surface of the blank contact element (20). The blank contact element (20) may be made of an elastic material, and the elastic material may be fluid-permeable or impermeable. Fluid flow may be possible only through the holes (30) or may be additionally made possible by the selective fluid-permeability of the elastic material. The holes may be distributed uniformly or randomly. The holes may have the same size and / or shape, or may have different sizes and / or shapes.

[0075] FIG. 2b schematically illustrates a blank contact element (20) in a cross-sectional view.

[0076] FIG. 3 schematically illustrates a blank contact element (20) according to another optional embodiment. According to this optional embodiment, the lower surface (24) of the blank contact element (20), configured to contact a vacuum blocking component (10), includes a plurality of protrusions (32) extending from the lower surface (24) of the blank contact element (20). One or more of these protrusions are configured to engage with the upper portion (16) of the blocking component (10), particularly the support element (14), when the blank contact element (10) is mounted on the vacuum blocking component (10). The upper portion (16) of the support element (14) may include a plurality of recesses having an arrangement, size, and shape that allow the protrusions (32) to engage with the support element (14). This can improve mechanical stability and prevent relative movement of the blank contact element (20) with respect to the support element (14) when the vacuum-blocked lens blank (12) is mechanically processed on the vacuum blocking component (10).

[0077] FIG. 4 schematically illustrates a method for manufacturing eyeglass lenses (400).

[0078] The method (400) includes the step of providing a vacuum blocking component (10) for vacuum blocking a lens blank (12) in step (402), wherein the vacuum blocking component (10) comprises a fluid-permeable blank contact element (20) having an upper surface (22) configured to contact the lens blank (12), and at least the upper surface (22) of the fluid-permeable blank contact element (12) is made of an elastic material. Additionally, the blank contact element (20) comprises a support element (14) having an upper portion (16) and a lower portion (18), wherein the lower portion (18) is configured to engage with a clamping device for clamping the vacuum blocking component (10), and the upper portion (16) supports the fluid-permeable blank contact element (20).

[0079] The method (400) includes the step of placing the lens blank (12) on the upper surface (22) of the blank contact element (20) in step (404) such that the front surface of the lens blank (12) completely covers the upper surface (22).

[0080] In step (406), the method (400) includes the step of applying a vacuum within a vacuum blocking part (10) to provide adsorption through a fluid-permeable elastic blank contact element (20) so as to adsorb the front surface of the lens blank (12) to the entire upper surface (22) of the fluid-permeable elastic blank contact element (20).

[0081] In step (408), the method (400) includes the step of mechanically processing at least a portion of the rear surface of the lens blank (12) while the front surface of the lens blank (12) is vacuum-sealed to the vacuum-sealed part (10). Explanation of the symbols

[0082] 10 vacuum shut-off components 12 lens blanks 14 Support Factors 16. Upper part of the support element 18 Lower part of the support element 20 blank contact elements 22 Top surface of the blank contact element 24. Underside of the blank contact element 26 sealed ribs 28 Extension of blank contact element 30 holes 32 protrusions 400 methods 402 - 408 Method Steps

Claims

Claim 1 A vacuum blocking component (10) for vacuum blocking a lens blank (12), wherein the vacuum blocking component (10) is a support element (14) having an upper portion (16) and a lower portion (18), wherein the lower portion (18) is configured to engage with a clamping device for clamping the vacuum blocking component (10); and - comprising a fluid-permeable blank contact element (20), wherein the blank contact element (20) is fluid-permeable, and at least the upper surface (22) of the blank contact element (20) configured to contact the lens blank (12) is made of an elastic material, and the blank contact element (20) further comprises a lower surface (24) for contacting the upper portion (16) of the support element (14), and the vacuum blocking part (10) applies a vacuum within the blocking part (10) to provide adsorption through the essentially entire upper surface (22) of the blank contact element (20) so as to adsorb the lens blank (12) to the upper surface (22) of the blank contact element (20) and adsorb the blank contact element (20) to the upper portion (16) of the support element (14), thereby adsorbing the lens blank (12) to the upper surface (22) of the blank contact element (20) and adsorbing the blank contact element (20) to the upper portion (16) of the support element (14), thereby adsorbing the lens blank (12) to the blank contact element (20). A vacuum blocking component configured to be fixed to an upper surface (22), wherein - the vacuum blocking component (10) comprises a sealing lip (26) disposed around the periphery of the blank contact element (20), and the sealing lip (26) is configured to assist in providing a vacuum inside the vacuum blocking component (10) and between the lens blank (12) and the upper surface (22) of the blank contact element (20), and - the sealing lip (26) and the blank contact element (20) are formed as a single component. Claim 2 In claim 1, the blank contact element (20) is a vacuum blocking component (10) made entirely of the elastic material. Claim 3 A vacuum blocking component (10) according to claim 1 or 2, wherein the elastic material comprises at least one material selected from the group consisting of polyurethane-based materials and rubber-based materials. Claim 4 A vacuum blocking component (10) according to claim 1 or 2, wherein the elastic material is at least partially porous, and the fluid-permeability of the blank contact element is at least partially due to the porosity of the elastic material. Claim 5 A vacuum blocking component (10) according to claim 1 or 2, wherein the fluid permeability of the blank contact element is at least partially due to one or more holes (30) formed in the blank contact element (20). Claim 6 In claim 1 or 2, the shape and size of the upper surface (22) of the blank contact element (20) correspond to the shape and size of the lens blank (12) to be blocked, a vacuum blocking component (10). Claim 7 A vacuum blocking component (10), wherein, in claim 1 or 2, the blank contact element further comprises a lower surface (24) configured to contact the support element (14), and the blank contact element (20) comprises one or more protrusions (32) extending from the lower surface (24) of the blank contact element (20), and the one or more protrusions (32) are configured to engage with the support element (14) when the blank contact element (20) is mounted on the support element (14). Claim 8 A vacuum blocking component (10) according to claim 1 or 2, wherein the fluid-permeable blank contact element (20) is configured to shape-match the interface of the support element (14) forming an interface with the blank contact element (20). Claim 9 In claim 1 or 2, the upper portion (16) of the support element (14) is configured to support the fluid-permeable blank contact element (20) and is formed of a rigid fluid-permeable material, vacuum blocking component (10). Claim 10 In claim 1 or 2, the vacuum blocking component (10) is configured to provide static friction between the blank contact element (20) and the support element (14) such that the coefficient of friction is 2.5 or higher. Claim 11 A vacuum blocking component (10) according to claim 1 or 2, wherein the upper surface of the support element (14) comprises one or more concave portions, and the blank contact element (20) comprises one or more protrusions (32) configured to mechanically engage with the one or more concave portions on the upper surface of the support element (14) when the blank contact element (20) is mounted on the support element (14). Claim 12 In claim 1 or 2, the vacuum blocking component (10) comprises an adhesive that fixes the lower surface (24) of the blank contact element (20) to the upper surface of the support element (14). Claim 13 A method (400) for manufacturing eyeglass lenses, wherein the method (400) comprises: - a step (402) of providing a vacuum blocking component (10) according to claim 1 or 2; - a step (404) of placing the lens blank (12) on the upper surface (22) of the blank contact element (20) such that the front surface of the lens blank (12) completely covers the upper surface (22); - a step (406) of applying a vacuum within the vacuum blocking component (10) to provide adsorption through the fluid-permeable elastic blank contact element (20) so that the front surface of the lens blank (12) is adsorbed to the entire upper surface (22) of the fluid-permeable elastic blank contact element (20); and - a step (408) of mechanically processing at least a portion of the rear surface of the lens blank (12) while the front surface of the lens blank (12) is vacuum-blocked by the vacuum blocking component (10). Claim 14 delete Claim 15 delete Claim 16 delete Claim 17 delete Claim 18 delete Claim 19 delete Claim 20 delete Claim 21 delete Claim 22 delete Claim 23 delete Claim 24 delete Claim 25 delete Claim 26 delete Claim 27 delete

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