Laminating apparatus and method for laminating a functional foil onto a surface of an optical element

Abstract

A lamination apparatus (1) is provided for laminating a functional foil (20) onto the surface (31) of an optical element (30). The lamination apparatus (1) includes a holding module (2) comprising: a sleeve-shaped foil holder (3) extending along a central longitudinal axis (L) and having an opening (6) at a longitudinal upper end (3.1) of the foil holder (3), wherein the longitudinal upper end (3.1) is configured to hold the functional foil (20); and an optical element holder (4) for holding the optical element (30), wherein the foil holder (3) surrounds the optical element holder (4). The lamination apparatus (1) includes a thermoforming module (5) including at least one air channel (7) for providing an airflow with controlled temperature and controlled pressure, wherein the at least one air channel (7) is arranged at a longitudinal lower end (5.1) of the thermoforming module (5). The holding module (2) and the thermoforming module (5) are arranged along a central longitudinal axis (L) such that the lower longitudinal end (5.1) of the thermoforming module (5) and the upper longitudinal end (3.1) of the foil holder (3) face each other. The thermoforming module (5) is movable along the central longitudinal axis (L) to adjust the distance between the lower longitudinal end (5.1) of the thermoforming module (5) and the upper longitudinal end (3.1) of the foil holder (3). The foil holder (3) includes at least one vacuum channel (8). The laminating device (1) includes a vacuum pump (9) connected to at least one vacuum channel (8) for applying a vacuum inside the foil holder (3). The optical element holder (4) is movable within the foil holder (3) along the central longitudinal axis (L) at an adjustable speed.

Description

[0001] This disclosure relates to a lamination apparatus and / or method for laminating functional foil onto the surface of optical elements, particularly lenses. Therefore, this disclosure relates to the technical field of manufacturing and / or laminating optical elements, particularly lenses (e.g., ophthalmic lenses, such as spectacle lenses).

[0002] Manufacturing optical components, particularly lenses (such as ophthalmic lenses), typically involves applying one or more functional layers and / or coatings to the optical components, which provide specific properties. For example, functional layers can be applied to achieve scratch resistance and / or antireflective properties of the optical components (i.e., improved scratch resistance and / or reduced light reflection). Currently, functional layers are typically applied using complex, time-consuming, and expensive processes. For example, hard coatings are applied via dip coating, while antireflective coatings are applied via physical vapor deposition. Applying functional foils to the surface of optical components (such as optical lenses) via foil lamination is highly useful, as it reduces manufacturing complexity and cost and shortens production time.

[0003] The process of “laminating” a film onto the surface of an optical element typically involves thermoforming. Accordingly, this functional layer is usually heated and shaped to achieve a desired curvature, and then laminated onto the surface of the optical element, i.e., firmly attached to said surface using, for example, an adhesive. In the case of an ophthalmic lens, the functional layer is typically laminated onto the front surface of the lens.

[0004] Known methods for applying functional layers to optical elements have various drawbacks, particularly the risk of suboptimal quality where air is trapped between the functional layer and the optical element, resulting in air bubbles. Other disadvantages include: the process is unsuitable for many types of geometries, especially free-form surfaces; and the applied functional layer has a high risk of wrinkling and damage during application, further reducing lamination quality.

[0005] WO 2021 / 170705 A1 describes a method for laminating a functional film onto an optical article, the method comprising: thermoforming the functional film to provide a predetermined target curvature for the functional film based on the curvature of the surface of the optical article on which the functional film is to be applied; applying the functional film onto the surface of the optical article; pressing the functional film against the surface of the optical article to adhere the functional film to the surface of the optical article; and, after application, heating the functional film at at least one predetermined temperature such that the functional film conforms to the curvature of the surface of the optical article.

[0006] US 2018 / 267222 A1 describes a method for manufacturing an optical lens molded onto a first curved optical film, the method comprising: providing a first optical film comprising alternating first and second polymer layers; providing a thermoforming tool having a curved surface; heating the first optical film and conforming it to the curved surface to form the first curved optical film; and molding an optical lens onto the first curved optical film. However, this method is quite complex because a thermoforming tool having a curved surface corresponding to the desired curvature of the optical film is required, and the optical lens is manufactured by molding and casting, i.e., manufacturing the optical lens corresponding to the desired curvature and the curved optical film. This approach—where the optical film contacts the tool surface, is subsequently stretched, then the optical lens is molded onto the optical film, and the thermoforming tool is removed after the molding process—can negatively impact the quality of the resulting lamination. The described method does not achieve good control over avoiding air bubbles.

[0007] WO 2023 / 110887 A1 describes a method comprising: providing an article having a non-zero radius of curvature and a thermoplastic film; moving the two relative to each other such that the thermoplastic film contacts the article; applying heat to the thermoplastic film, causing the heated thermoplastic film to shrink and take on the shape and curvature of the article, thereby producing a thermoformed thermoplastic film; and optionally, laminating the thermoformed thermoplastic film onto the surface of an optical article by means of an adhesive layer positioned between the optical article and the thermoplastic film. However, this method involves laminating a functional film by shrinkage, which has a high probability of introducing air bubbles, and laminating thick foils by this method has a high probability of introducing wrinkles. Furthermore, the heating process does not allow for good temperature control, and the described method is limited to lamination on convex surfaces.

[0008] WO 2019 / 180251 A1 describes a method for producing spectacle lenses from spectacle lens blanks having optically finished surfaces and cylindrical edge surfaces, wherein a protective film is applied to the optically finished surfaces. However, this method is limited to laminating the protective layer onto the front surface of the spectacle lens, wherein the method involves only a vacuum, thereby providing a maximum pressure of about 0.1 MPa.

[0009] WO 2006 / 105999 A1 describes an apparatus for bonding a functionalized flexible planar film to an optical lens. The functionalization process involves bonding, transferring, or molding a functionalized flexible planar film onto an optical lens. However, the described approach separates the heating process from the bending process and cannot adequately control the desired curvature of the bent film, leading to a risk of reduced lamination quality, such as wrinkles and bubbles.

[0010] WO 2021 / 170704 A1 describes a thermoforming machine including a thermoforming chamber having at least one heated air inlet through which heated air flows into the thermoforming chamber under controlled pressure. The air inlet cooperates with a heated air flow distribution regulator located within the thermoforming chamber, through which the heated air flows out of the thermoforming chamber at a predetermined temperature. The regulator includes a heated air flow regulating hood for receiving the heated air flow, the hood having a plurality of flow limiting elements providing different airflow restrictions. However, the described approach focuses on the thermoforming of films, where the accuracy of the desired curvature of the film is improved by reducing the temperature gradient in the film during thermoforming; however, this approach does not involve the process of laminating the film onto the surface of an optical article, and in particular, does not involve potential risks.

[0011] WO 2020 / 074599 A1 describes a laminator comprising: a film support for receiving a functional film to be laminated; an article support configured to receive and position an optical article in a predetermined orientation; and an actuating member configured to move the film support and the article support toward each other to laminate the functional film received in the film support onto the optical article received in the article support under a predetermined pressure. However, the described approach focuses on the lamination process, wherein the film is laminated onto the optical article at a predetermined pressure, but this approach does not explicitly address the thermoforming process of the film, and in particular, does not address potential risks. Furthermore, the functional film axis must be aligned with the lens axis, thus complicating the system.

[0012] US 2016 / 0052201 A1 describes a method for producing decorative lenses that effectively suppresses lens deformation when a film material is laminated onto the lens, even when the lens shape varies greatly, without requiring support fixtures or the like for suppressing lens deformation for corresponding lenses with different shapes.

[0013] In view of this prior art, the purpose of this disclosure is to disclose an apparatus and / or method, each of which is suitable for enriching the prior art. For example, in view of WO 2021 / 170705 A1, which is the closest prior art, this purpose may involve providing a lamination apparatus and method that enables higher lamination quality between a functional foil and an optical element including a concave surface, a convex surface, or a freeform surface, such as avoiding air bubbles trapped between the laminated functional foil and the optical element.

[0014] This objective is achieved by the features of the independent claims, particularly the lamination apparatus and method having the features of the respective independent claims. Optional embodiments are described in detail in the dependent claims and the specification.

[0015] In one aspect, a lamination apparatus is provided for laminating a functional foil onto the surface of an optical element (e.g., a freeform surface and / or a curved surface).

[0016] The laminating apparatus includes a holding module. The holding module includes a sleeve-shaped foil holder extending along a central longitudinal axis and having an opening at its longitudinal upper end. The longitudinal upper end of the foil holder is configured to hold a functional foil. The holding module also includes an optical element holder for holding optical elements. The foil holder surrounds the optical element holder.

[0017] The laminating apparatus includes a thermoforming module comprising at least one air passage for providing an airflow with controlled temperature and controlled pressure (e.g., uniform). The at least one air passage is arranged at the lower longitudinal end of the thermoforming module.

[0018] The holding module and the thermoforming module are arranged along a central longitudinal axis such that the lower longitudinal end of the thermoforming module and the upper longitudinal end of the foil holder face each other. The thermoforming module can be moved along the central longitudinal axis to adjust the distance between the lower longitudinal end of the thermoforming module and the upper longitudinal end of the foil holder.

[0019] The foil holder includes at least one vacuum channel. The laminating apparatus includes a vacuum pump connected to at least one vacuum channel for applying a vacuum inside the foil holder.

[0020] The optical element holder can move at an adjustable speed along the central longitudinal axis inside the foil holder.

[0021] On the other hand, a method is provided for laminating a functional foil onto the surface of an optical element (e.g., by using a lamination apparatus).

[0022] The method includes placing an optical element on an optical element holder of a laminating apparatus. The method also includes placing a functional foil on a foil holder of the laminating apparatus. The functional foil and the optical element are positioned such that the optical element is arranged at a distance below the functional foil with its surface facing the foil.

[0023] The method includes (e.g., via a thermoforming module of a laminating apparatus) providing an airflow with controlled temperature and controlled pressure above the placed functional foil.

[0024] The method involves applying a vacuum below the placed functional foil (and / or between the placed functional foil and the placed optical element) simultaneously with providing an airflow.

[0025] The method involves arranging a functional foil onto the surface of an optical element while providing an airflow and applying a vacuum.

[0026] The method further includes adjusting and / or temporarily increasing the controlled pressure of the airflow before the functional foil is arranged on the surface of the optical element, until the functional foil is stretched into a spherical shape with a radius smaller than the radius of the central region of the optical element.

[0027] In addition, a method suitable for manufacturing eyeglass lenses is provided.

[0028] The method includes laminating a functional foil onto the surface of an optical element using a method according to this disclosure. The optical element is a spectacle lens to be manufactured, or a lens blank, semi-finished lens blank, or uncut finished lens from which a spectacle lens is manufactured.

[0029] In the operating state of the laminating apparatus (e.g., when the laminating apparatus is in use), the functional foil is held or positioned at the longitudinal upper end of the foil holder, wherein the opening at the longitudinal upper end of the foil holder is closed by the functional foil. The center of the functional foil may be arranged above the opening (and / or arranged to close the opening). The optical element is held by an optical element holder located inside the foil holder (i.e., surrounded by the foil holder), wherein the optical element is arranged below the functional foil (and therefore, below the opening at the longitudinal upper end of the foil holder).

[0030] Accordingly, the foil holder is configured to hold the functional foil, and the optical element holder is configured to hold the optical element such that the optical element is arranged at a distance below the functional foil with its surface facing the functional foil. The foil holder can be configured to hold the functional foil by placing it on the foil holder (e.g., its longitudinal upper end). The optical element holder can be configured to hold the optical element by placing it on the optical element holder (e.g., its longitudinal upper end).

[0031] During the operation of the laminating apparatus, an airflow with controlled temperature and pressure is provided above the functional foil (e.g., between the lower longitudinal end of the thermoforming module and the functional foil) by providing an airflow with controlled temperature and pressure at at least one air channel and thus at the lower longitudinal end of the thermoforming module. The airflow can be (e.g., uniformly) guided toward an opening at the upper longitudinal end of the foil holder, and therefore toward the functional foil. The functional foil is stretched and / or bent into a spherical shape, for example, to achieve a desired curvature of the functional foil. In particular, the functional foil is stretched and / or bent through the opening at the upper longitudinal end of the foil holder.

[0032] By applying a vacuum inside the foil holder, a vacuum is applied below the functional foil, particularly between the functional foil and the optical element, while the laminating device is in operation.

[0033] Accordingly, by providing a flow of heated air and (e.g., simultaneously) applying a vacuum, the functional foil can be shaped to a desired curvature, a process also known as thermoforming.

[0034] Vacuum is considered to be negative air pressure, such as pressure below atmospheric pressure, and is not limited to the extreme option of having no air inside the foil holder at all (i.e., removing any air). Vacuum is applied by pumping (and / or drawing) air from inside the foil holder through at least one vacuum channel via a vacuum pump.

[0035] Optical elements can be spectacle lenses. Spectacle lenses can be intended for use in sunglasses and / or refractive eyewear, for example, as specified in Section 3 of ISO 12312-1:2013(E). Optical elements can be lens blanks. Optical elements can be semi-finished lens blanks, for example, as specified in Section 4 of ISO 10322-2:2016(E). Optical elements can be uncut finished lenses, for example, as specified in Section 4 of ISO 8980-1:2017(E), which can be referred to as finished spectacle lens products. Optical elements can have dimensions corresponding to the final dimensions of the (final) optical element. In other words, optical elements can be pre-manufactured. Lamination of functional foil can be performed at the end of the manufacturing process of the optical element, at which point the optical element is ready for use (e.g., ready for wear by a user in the case of an ophthalmic lens) or at least the surface of the optical element has been finished (e.g., the surface has been cut and polished to achieve the desired surface form).

[0036] A lens blank can refer to an unfinished precursor to an eyeglass lens, such as a lens blank having an unfinished front surface and an unfinished rear surface. Lens blanks can be provided during the molding process. However, a lens blank can also refer to a partially finished precursor to an eyeglass lens. For example, a lens blank may have a partially or fully finished front surface and may be covered with a protective foil or coating. As commonly understood and defined in Section 3.8.1 of ISO 13666:2019 (E), a lens blank can be a piece of optical material having an optically finished surface for use in the manufacture of lenses.

[0037] Optical components can be spectacle lens blanks, semi-finished spectacle lens products, or finished spectacle lens products, and can specifically meet the requirements specified in EN ISO 13666:2012. Throughout this disclosure, unless otherwise expressly stated, the term "substrate" generally refers to spectacle lenses, lens blanks, semi-finished spectacle lens products, and / or finished spectacle lens products.

[0038] As is generally understood and defined in section 3.5.2 of ISO 13666:2019 (E), spectacle lenses can be ophthalmic lenses worn in front of the eyeball but not in contact with the eyeball, as per section 3.5.1 of ISO 13666:2019 (E).

[0039] The surface of an optical element can be concave, convex, or freeform. In other words, the lamination process performed by the lamination apparatus and method described above is not limited to a specific surface form of the surface to be laminated. The surface can be the front or back surface of a spectacle lens, a spectacle lens blank, a semi-finished spectacle lens product, or a finished spectacle lens product.

[0040] As is generally understood and defined in section 3.2.13 of ISO 13666:2019 (E), the front surface of an eyeglass lens or lens blank is the surface of the lens or lens blank intended to be mounted away from the eye.

[0041] As is generally understood and defined in section 3.2.14 of ISO 13666:2019 (E), the rear surface of an eyeglass lens or lens blank is the surface of the lens or lens blank intended to be fitted closer to the eye.

[0042] Functional foils can be foils and / or films comprising nanostructures for providing one or more functions, such as scratch-resistant, anti-reflective, and / or easy-to-clean coatings (i.e., coatings that provide dust-resistant properties). Other functions are also possible, such as light polarization, wavelength filtering defined for a specific wavelength range, anti-fogging properties, anti-fogging properties, UV protection, tinting, mirror finish, self-healing, self-cleaning, and / or antistatic properties.

[0043] "Sleeve-like" means that the foil holder at least circumferentially surrounds the optical element holder. Accordingly, the foil holder includes a foil holder cavity (e.g., formed in a sleeve shape), wherein the optical element holder is disposed inside the foil holder, i.e., inside the foil holder cavity. Thus, the foil holder surrounding the optical element holder corresponds to the optical element holder being disposed inside the foil holder and / or configured to hold the optical element inside the optical element holder.

[0044] The above-described lamination apparatus and method offer the advantages of improved apparatus and method for providing a reliable process of laminating functional foil onto the (e.g., freely designed) surface of optical elements, thereby reducing processing cycle time and lowering cost and complexity.

[0045] High lamination quality can be achieved by utilizing an airflow with controlled temperature and pressure above the functional foil during (particularly simultaneously) and by applying a vacuum below the functional foil, whereby air bubbles trapped by the laminated functional foil and wrinkles of the laminated functional foil can be avoided. In particular, the application of vacuum prevents air trapping between the functional foil and the optical element, and the vacuum also helps to subject the functional foil to uniform bending forces when it is bent to a desired curvature before being placed onto the surface of the optical element. Accordingly, this disclosure also provides optimization or at least improvement of the adhesion and / or shape of the functional film to be applied.

[0046] Furthermore, this lamination apparatus provides a non-contact thermoforming process, wherein any bending and / or stretching of the functional foil is achieved exclusively by the provided airflow and the applied vacuum, without requiring any additional thermoforming tools. Accordingly, the lamination apparatus is less complex, and the elimination of thermoforming tools that must be applied and then removed from the functional foil reduces the risk of damaging the functional foil during the thermoforming and lamination processes.

[0047] Compared to WO 2021 / 170705 A1, the lamination apparatus and method described above produce higher lamination quality, particularly in that air bubbles are avoided due to the simultaneous provision of airflow and the application of vacuum, whereas only pressurized air is applied in WO 2021 / 170705 A1. Furthermore, since the functional foil is held by a foil holder (e.g., by clamping the functional foil between the thermoforming module and the foil holder), the functional foil is fixed to prevent movement, thereby facilitating bending and stretching of the functional foil, where heavy stretching of the functional foil is not required, unlike the method in WO 2021 / 170705 A1. This further improves lamination quality, such as preventing wrinkles.

[0048] Compared to US 2018 / 267222 A1, this lamination apparatus is significantly less complex because it does not use thermoforming tools for shaping the functional foil. Instead, it exclusively shapes the functional foil to the desired curvature by providing an airflow and employing a vacuum. Furthermore, molding and casting of optical elements are unnecessary because pre-manufactured optical elements are used, allowing the functional foil to be laminated onto any free-form surface. Overall, the approach using the aforementioned lamination apparatus and method results in higher lamination quality, particularly by avoiding damage to the functional foil and trapped air bubbles due to the non-contact method for shaping and laminating the functional foil onto the optical element, and by simultaneously providing an airflow and applying a vacuum.

[0049] In addition, US 2018 / 267222 A1 covers a fairly different application scenario, which mainly involves the manufacture of film stacks in display or imaging systems, and the aforementioned lamination device is configured to laminate functional foils onto individual optical elements, particularly lenses.

[0050] Compared to WO 2023 / 110887 A1 (which describes laminating a film by shrinking a functional film, wherein no pressure is applied to the film or only a small pressure is applied during the lamination process to avoid stretching or bending the film), this method achieves higher lamination quality by avoiding bubbles and wrinkles due to the simultaneous provision of airflow and the application of vacuum. Furthermore, the lamination apparatus provides better temperature control by providing airflow with controlled temperature and pressure. Additionally, while WO 2023 / 110887 A1 uses a contact approach, the technology disclosed herein uses a non-contact approach with the provided airflow and the applied vacuum, thereby reducing the risk of damaging the functional foil structure. Moreover, the lamination apparatus described above can be used to laminate any free-form surface, not just the convex surfaces described in WO 2023 / 110887 A1.

[0051] Compared to WO 2019 / 180251 A1, this method avoids bubbles and wrinkles by simultaneously providing airflow and applying a vacuum, thus achieving higher lamination quality, whereas the method in WO 2019 / 180251 A1 only involves a vacuum. Furthermore, the lamination apparatus and method described above are not limited to laminating specific optical elements and specific surface forms, while the method in WO 2019 / 180251 A1 is limited to laminating a protective layer onto the front surface of a spectacle lens.

[0052] Compared to WO 2006 / 105999 A1, the heating and force generated by the provided airflow are maintained throughout the film bending and lamination processes, thus providing good lamination quality. Lamination quality is further improved by simultaneously applying a vacuum, particularly by avoiding wrinkles and bubbles. Furthermore, unlike the method in WO 2006 / 105999 A1, the technology disclosed herein uses a non-contact approach with the provided airflow and the applied vacuum, thereby reducing the risk of damage to the functional foil structure.

[0053] Compared to WO 2021 / 170704 A1, higher lamination quality is achieved by avoiding bubbles and wrinkles due to the simultaneous provision of airflow and the application of vacuum, while the method of WO 2021 / 170704 A1 only describes an airflow toward the membrane with controlled temperature and regulated distribution during the thermoforming process of the membrane.

[0054] Compared to WO 2020 / 074599 A1, higher lamination quality is achieved by simultaneously providing airflow and applying vacuum, thus avoiding bubbles and wrinkles. The method in WO 2020 / 074599 A1 only describes the lamination process in which the film is laminated onto the optical article under a predetermined pressure. Furthermore, it eliminates the need for additional alignment of the functional foil axis with the optical element axis, thereby reducing the system complexity of the aforementioned lamination apparatus.

[0055] The following section explains in detail possible further implementations of the lamination apparatus and / or method described herein.

[0056] The laminating apparatus can be configured to provide an airflow that is directed downwards and / or toward an opening at the longitudinal upper end of the foil holder. Advantageously, the airflow is directed directly toward a portion of the functional foil to be laminated onto the surface of the optical element, wherein, in the operating state of the laminating apparatus, said portion is arranged above the opening at the longitudinal upper end of the foil holder. Accordingly, a non-contact thermoforming process of said portion of the functional foil can be performed by controlling the provided airflow to achieve a desired curvature before laminating the functional foil onto the optical element.

[0057] The laminating apparatus can be configured to (exclusively) bend and / or stretch the functional foil into a (desired) spherical shape and / or curvature by providing an airflow and applying a vacuum, for example, wherein a controlled temperature and / or controlled pressure can be varied and / or adjusted. Advantageously, the laminating apparatus provides a non-contact thermoforming process, wherein the thermoforming of the functional foil is achieved exclusively by the provided airflow and the applied vacuum, without requiring any additional thermoforming tools, particularly any tools that must be in direct contact with the functional foil. Accordingly, the risk of damaging the functional foil during the thermoforming and laminating processes is greatly reduced.

[0058] The laminating apparatus may include a control unit for controlling a thermoforming module and a vacuum pump. In operation of the laminating apparatus, the control unit can be configured to control the thermoforming module to provide an airflow with controlled temperature and pressure, and simultaneously (i.e., concurrently with providing the airflow) activate and / or control the vacuum pump to apply a vacuum within the foil holder. Advantageously, the laminating apparatus is configured to automatically control optimized settings for achieving the desired curvature of the functional foil, thereby achieving improved accuracy in the thermoforming process and high lamination quality of the functional foil laminated onto the optical element without damage, wrinkles, or trapped bubbles.

[0059] The lamination apparatus may include a (first) moving unit for moving the thermoforming module. The (first) moving module may include an actuator and / or a motor. A control unit may be configured to control the (first) moving unit to move the thermoforming module at an adjustable speed (e.g., a constant speed). Advantageously, the thermoforming module can be moved in a controllable, non-manual manner, allowing the thermoforming module to be positioned at a desired location with high accuracy (e.g., arranging at least one air passage of the thermoforming module relative to the placed functional foil at a desired location to provide airflow, and / or securing the functional foil at the desired location by clamping it between the thermoforming module and a foil holder).

[0060] The upper longitudinal end of the optical element holder can be configured to hold the optical element such that the surface of the optical element is arranged to face away from the upper longitudinal end of the optical element and / or towards the upper longitudinal end of the foil holder. Advantageously, in the operating state of the laminating apparatus, the surface of the optical element (held by the optical element holder) is oriented toward the functional foil (held by the foil holder), so that, for example, the orientation of the optical element does not need to be changed during the method. In other words, during the method (i.e., the lamination process), the optical element is always stationary on the optical element holder.

[0061] The longitudinal upper end (e.g., the shape of the longitudinal upper end) of the optical element holder can be at least partially adapted to the shape (and / or curvature) of the optical element (e.g., a second surface of the optical element arranged opposite to the surface of the optical element). The diameter and / or size of the opening can be larger than the diameter and / or size of the longitudinal upper end of the optical element holder (and / or the optical element). Advantageously, by placing the optical element on the optical element holder, the optical element can be sufficiently held and secured without the need for any additional fastening elements. Furthermore, due to the adaptable form of the optical element holder, the optical element is oriented and aligned in the desired position for performing the method (particularly the lamination process), so that the orientation and alignment of the optical element do not need to be changed during the method.

[0062] The optical element holder can move at an adjustable speed along a central longitudinal axis within the foil holder. The lamination apparatus may include a (second) moving unit for moving the optical element holder. The (second) moving unit may include an actuator and / or a motor. A control unit may be configured to control the (second) moving unit to move the optical element holder at an adjustable speed (e.g., a constant speed). Advantageously, the optical element can be moved upward at a controlled speed, thus benefiting from a constant pressure applied to the functional foil as the moving optical element presses against it to arrange the functional foil onto the surface of the optical element.

[0063] The foil holder can be stationary and / or immovable. In other words, the functional foil can be arranged onto the surface of the optical element simply by moving the optical element (i.e., the optical element holder). Advantageously, a simple solution for arranging the functional foil onto the surface of the optical element is provided, thereby limiting the number of technical components, especially movable components, resulting in an arrangement less prone to technical difficulties such as wear. Furthermore, by avoiding any additional movement of the functional foil during thermoforming other than stretching, the risk of damage to the functional foil during thermoforming and lamination processes is limited.

[0064] The upper longitudinal end of the foil holder can be configured to hold the functional foil such that the portion of the functional foil to be laminated onto the surface of the optical element is positioned above the opening and / or the opening is (completely) closed by the functional foil. The functional foil can be larger than the opening. Advantageously, the portion of the functional foil to be laminated onto the surface of the optical element is directly accessible and can therefore be positioned directly and immediately onto the surface after the desired curvature has been achieved during thermoforming. Thus, there is no need to move the functional foil, thereby reducing any risk of damaging the functional foil or minimizing any alteration to its achieved curvature.

[0065] The thermoforming module is movable along its central longitudinal axis to clamp the functional foil between the lower longitudinal end of the thermoforming module and the upper longitudinal end of the foil holder during the operation of the laminating apparatus. Advantageously, no additional clamping components are required to hold the functional foil in the desired position. Furthermore, the mobility of the thermoforming module provides two technical functions simultaneously: arranging at least one air channel of the thermoforming module in a desired position relative to the placed functional foil to provide airflow, and securing the functional foil in the desired position, thereby resulting in a more accurate thermoforming and laminating process.

[0066] The thermoforming module may include a hot chamber fluidly connected to at least one air passage. The thermoforming module may include at least one air inlet for supplying air to the hot chamber. The thermoforming module may include a heating element disposed within the hot chamber. The heating element may be configured to heat the air supplied by the at least one air inlet to a controlled temperature. A control unit may be configured to control the heating element.

[0067] The thermoforming module may further include a thermocouple disposed within the heated chamber. The thermocouple can be configured to measure the temperature of air heated by the heating element, for example, to determine when the air has reached a controlled temperature. A control unit can be configured to receive a signal (e.g., voltage) from the thermocouple, wherein the signal may depend on the temperature of the air within the heated chamber. Advantageously, the thermoforming module is controllable to provide an airflow with a controlled temperature with high accuracy because the air temperature can be monitored during the heating process, and, for example, the heating element can be controlled based on the temperature measured by the thermocouple.

[0068] The thermoforming module may further include a pressure unit (and / or pressure regulator) for providing controlled pressure to an airflow. The pressure unit may be disposed within a hot chamber and / or at least one air passage. Alternatively or additionally, the lamination device may include an air pressure unit (e.g., an air pump) for providing controlled pressure to air (e.g., an airflow). The air pressure unit may be fluidly connected to the thermoforming module (e.g., at least one air inlet) for supplying air (e.g., an airflow) with controlled pressure to the hot chamber. A control unit may be configured to control the pressure unit and / or the air pressure unit. The pressure unit and / or the air pressure unit may include, for example, an air compressor and / or a fan. Advantageously, the pressure unit is provided, for example, as part of the thermoforming module, and is controllable to provide a controlled, desired pressure to the airflow.

[0069] The foil holder may include a window for observing the optical elements and / or functional foil (e.g., during the execution of the method and / or lamination process). The window may be arranged adjacent to the longitudinal upper end of the foil holder. Advantageously, the user can observe the method (i.e., the thermoforming and lamination process) and can intervene in case of any irregularities or problems, for example, by adjusting the temperature and pressure of the provided airflow or by interrupting or stopping the thermoforming or elimination process.

[0070] The thermoforming module may further include a cooling unit for providing a controlled cooling process and / or for cooling the airflow to achieve a controlled temperature. A control unit may be configured to control the cooling unit. Advantageously, the thermoforming module can control the temperature of the provided airflow more accurately and quickly by actively cooling the air, for example, when the air has been heated to a desired higher temperature and / or at the end of the thermoforming and lamination process (at which point the controlled temperature can be reduced to the setting temperature of the functional foil).

[0071] The optical element holder can be rod-shaped and extend along a central longitudinal axis. Advantageously, this provides a simple design for the optical element holder (which can move along the central longitudinal axis), in which the number of technical components, especially movable components, is limited, resulting in an arrangement less prone to technical difficulties such as wear.

[0072] The holding module may include a guide element (located inside and / or surrounded by the foil holder) for guiding the optical element holder. The guide element may be sleeve-shaped and extend along a central longitudinal axis, for example, having an open longitudinal end. The optical element holder may be partially (and / or movably) arranged inside the guide element. Advantageously, the guide element is a simple and easily implemented option for holding and guiding an optical element holder that can move laterally along an axis (i.e., the central longitudinal axis).

[0073] The foil holder may have an airtight lower longitudinal end. Optical element holders and / or guiding elements may extend airtightly through the lower longitudinal end of the foil holder. Advantageously, a vacuum can be effectively applied inside the foil holder via at least one vacuum channel, wherein the possibility of air entering the foil holder is eliminated or at least limited by providing an airtight lower longitudinal end. In particular, the foil holder may include only one opening, i.e., an opening at the upper longitudinal end, which is closed by a functional foil in the operating state of the laminating apparatus (i.e., when a vacuum is to be applied).

[0074] At least one air channel may be positioned directly above an opening at the longitudinal upper end of the foil holder. The at least one air channel may include multiple air channels for providing uniform heat distribution and / or uniform pressure distribution. Advantageously, the airflow is directed directly toward a portion of the functional foil to be laminated onto the surface of the optical element, wherein, in the operating state of the lamination apparatus, said portion is arranged above an opening at the longitudinal upper end of the foil holder. Furthermore, uniform heat distribution and / or uniform pressure distribution provide more efficient thermoforming by uniformly stretching the functional foil to achieve the desired curvature, wherein the functional foil is uniformly heated and / or stretched to minimize any additional stress on the functional foil that could cause damage, such as tearing, during thermoforming.

[0075] Airflow can be directed downwards (e.g., along a central longitudinal axis) and / or toward the functional foil (and / or the opening at the longitudinal upper end of the foil holder). The airflow can be uniform. The airflow can include a uniform heat distribution and / or a uniform pressure distribution. The airflow can uniformly bend and / or stretch the functional foil in all directions. Advantageously, as stated above, the airflow is directed directly toward the portion of the functional foil to be laminated onto the surface of the optical element, thereby providing a non-contact thermoforming process for said portion of the functional foil to achieve the desired curvature. (Regarding heat and / or pressure distribution) A uniform airflow provides more efficient thermoforming by uniformly stretching the functional foil to achieve the desired curvature, wherein the functional foil is uniformly heated and / or stretched to minimize any additional stress on the functional foil that could cause damage, such as tearing, during thermoforming.

[0076] This method may include (exclusively) bending and / or stretching the functional foil to a (desired) spherical shape and / or curvature by providing an airflow and applying a vacuum before the functional foil is disposed onto a surface, for example, wherein a controlled temperature and / or controlled pressure may be varied and / or adjusted. The functional foil may be bent and / or stretched to a (desired) spherical shape and / or curvature without additional tools (and / or in a non-contact manner). The functional foil may be bent and / or stretched through an opening at the longitudinal upper end of a foil holder. Advantageously, a non-contact thermoforming process is provided that does not require any additional thermoforming tools, wherein thermoforming is performed and the desired curvature is achieved by an airflow with controlled and adjustable temperature and pressure. By arranging a thermoforming module above the functional foil and guiding the airflow toward a portion of the functional foil to be laminated onto the surface of an optical element (wherein this portion is arranged above an opening at the longitudinal upper end of the foil holder), the functional foil may advantageously be stretched through said opening to achieve the desired curvature.

[0077] The desired spherical shape and / or curvature can be independent of and / or correspond to the curvature of the surface of the optical element. Advantageously, it has been found that it is not necessary to thermoform the functional foil into the precise form (i.e., curvature) of the surface before it is arranged onto the surface of the optical element. Thermoforming is initiated before the functional foil is arranged onto the surface to change the material of the functional foil from a rigid state to a soft, stretchable state, thereby allowing the functional foil to be stretched. Thermoforming can continue simultaneously with the arrangement of the functional foil onto the surface of the optical element by continuously providing an airflow above the functional foil and a vacuum below it, such that the form (and / or curvature) of the functional foil can be adapted to the form (and / or curvature) of the surface. The desired curvature is advantageous, for example, during the lamination process, i.e., when the functional foil is arranged onto the surface of the optical element, where the arrangement is performed gradually, rather than simultaneously arranging the functional foil onto the entire surface. For example, in the first stage, the optical element can be moved until its surface (particularly the central region of the surface) contacts the center of the curved functional foil (i.e., the area of ​​the functional foil closest to the surface of the optical element after the desired curvature of the functional foil has been achieved). Gradual arrangement continues by continuously moving the optical element, for example, until the entire surface is covered by the functional foil. Due to this gradual lamination process, a higher lamination quality is achieved, for example, where air between the functional foil and the surface can escape before being trapped as bubbles.

[0078] The functional foil can be disposed onto the surface of the optical element (e.g., solely) by moving the optical element (e.g., upward) toward the functional foil at an adjustable speed (e.g., by moving an optical element holder). The optical element can be moved in multiple stages, wherein in a first stage, the optical element can be moved until the central region of the optical element contacts the functional foil. For example, the optical element can be moved until the surface of the optical element is positioned at or inside an opening at the longitudinal upper end of the foil holder. Advantageously, the optical element can be moved upward at a controlled speed such that controlled pressure is applied to the functional foil as the moving optical element presses against it to dispose the functional foil onto the surface of the optical element. Thus, a simple solution to the lamination process is provided, wherein the functional foil is laminated onto the optical element simply by moving the optical element, without requiring any additional parts or tools.

[0079] The functional foil may include a pressure-sensitive adhesive and / or optical adhesive coated on one side of the functional foil. If the pressure-sensitive adhesive and / or optical adhesive are pre-coated on one side of the optical element, the functional foil may not include the pressure-sensitive adhesive and / or optical adhesive. The functional foil may be placed on a foil holder with one side of the functional foil facing the surface of the optical element. The pressure-sensitive adhesive may be configured to press against the surface of the optical element to hold the functional foil on the surface. Alternatively or additionally, the optical element may include a pressure-sensitive adhesive and / or optical adhesive coated on its surface. Advantageously, the pressure-sensitive adhesive and / or optical adhesive provides sufficient adhesive bonding between the functional foil and the surface of the optical element. Mechanical pressure may be applied to press the functional foil onto the optical element to activate the pressure-sensitive adhesive. Alternatively or additionally, an optical adhesive (i.e., an optically activatable adhesive) may be provided between the functional foil and the optical element and exposed to optical radiation (optionally, ultraviolet radiation) to activate the optically activatable adhesive. The functional foil and / or optical element may be at least partially transparent to the irradiated ultraviolet radiation. Therefore, ultraviolet radiation can irradiate the optical adhesive through the functional foil and / or through the optical element. Alternatively or additionally, the functional foil and / or optical element can be exposed to heat to activate and / or harden the adhesive provided between the functional foil and the optical element. Heat can be provided by heating the optical element, and / or the functional foil, and / or the ambient air surrounding the optical element and / or the functional foil. Alternatively or additionally, heat can be provided by the optical element and / or the functional foil at least partially absorbing optical radiation (e.g., infrared radiation). The terms "adhesive" and "adhesive compound" are used synonymously throughout this disclosure. One or more of these techniques for activating and / or hardening the adhesive can bond the adhesive and / or adhesive to the surface of the optical element (where the adhesive and / or adhesive is provided as a coating of the functional foil) and / or to the functional foil (where the adhesive and / or adhesive is provided as a coating of the surface of the optical element). By providing pressure-sensitive adhesive and / or optical adhesive as a coating of the functional foil and / or optical element, the method steps (or additional components of the lamination apparatus) for applying the adhesive and / or adhesive are eliminated, thereby simplifying the lamination process.

[0080] The functional foil can be disposed on a release film. The release film can be disposed on a second side of the functional foil opposite to the pressure-sensitive adhesive. The functional foil can be placed on a foil holder with its second side facing away from the optical element. The release film can be configured to be removed after the functional foil has been laminated to the surface of the optical element. Advantageously, the release film provides a safer possibility for manipulating the functional foil, especially when the functional foil is placed on the foil holder, because the release film can be held and direct contact with the functional foil is not required, thereby reducing any risk of damaging the functional foil.

[0081] The method may include clamping the placed functional foil between the foil holder and the thermoforming module by moving the thermoforming module of the laminating apparatus toward the foil holder. Advantageously, as stated above, the mobility of the thermoforming module provides two technical functions simultaneously: arranging at least one air channel of the thermoforming module in a desired position relative to the placed functional foil to provide airflow, and securing the functional foil in the intended position without requiring any additional clamping components, thereby resulting in a more accurate thermoforming and laminating process.

[0082] The controlled temperature may correspond to the glass transition temperature of the functional foil (e.g., the material of the functional foil) or a higher temperature. Advantageously, the functional foil is heated until it reaches the glass transition temperature, at which stretching of the functional foil is permitted, i.e., the material of the functional foil has changed from a rigid state to a soft, stretchable state.

[0083] This method may include adjusting and / or temporarily increasing the controlled pressure of the airflow before arranging the functional foil onto the surface of the optical element, until the functional foil is stretched into a spherical shape with a radius smaller than the radius of the central region of the optical element. The radius of the spherical shape of the stretched functional foil may be related to the radius of curvature of the spherical shape. The radius of the central region of the optical element may be related to the radius of curvature of the central region of the surface of the optical element facing the functional foil. The radius of the spherical shape of the functional foil may be in the range of 40 mm to 80 mm. Advantageously, as stated above, it has been found that it is not necessary to thermoform the functional foil into the precise form (i.e., curvature) of the surface before arranging it onto the surface of the optical element, but rather thermoforming can continue simultaneously with arranging the functional foil onto the surface of the optical element, such that the form (and / or curvature) of the functional foil can be adapted to the form (and / or curvature) of the surface. As further stated above, the lamination process (i.e., the arrangement of the functional foil onto the surface of the optical element) can be performed gradually, wherein, in a first stage, the optical element can be moved until the surface of the optical element (particularly the central region of the surface) contacts the center of the curved functional foil (i.e., the area of ​​the functional foil closest to the surface arrangement of the optical element after the desired curvature of the functional foil has been achieved). It has been found that if the spherical shape of the curved functional foil has a radius smaller than the radius of the central region of the surface, then even higher lamination quality can be achieved through the gradual lamination process.

[0084] This method may include reducing the controlled temperature to a setting temperature of the functional foil (e.g., the material of the functional foil) after the functional foil has been arranged onto the surface of the optical element. Advantageously, the thermoforming process may be terminated in a controlled manner to reduce, for example, any additional stress on the functional foil until the setting temperature is reached, at which temperature the functional foil is cooled to its finished shape without allowing any further stretching. Accordingly, the controlled temperature may be reduced after the functional foil has been arranged onto the surface to allow for further stretching (i.e., thermoforming) of the functional foil during the lamination process, thereby allowing, for example, the form of the functional foil to be adapted to the form of the surface of the optical element to achieve higher lamination quality.

[0085] This method may include setting a controlled pressure to atmospheric pressure and / or stopping the pressure on the airflow after the functional foil has been placed on the surface of the optical element. Advantageously, the method may end in a controlled manner to avoid any alteration to the lamination result, for example, by stopping any pressure on the laminated functional foil. Furthermore, pressure adjustment can be further simplified by moving the thermoforming module away from the foil holder, where, for example, no sudden pressure equalization occurs when the clamp is opened.

[0086] This method may include stopping the application of vacuum when the setting temperature is reached. Stopping the application of vacuum may include decompressing the interior of the foil holder (and / or allowing air to enter the interior of the foil holder), for example, until atmospheric pressure is reached. Advantageously, the thermoforming process may be performed and terminated in a more controlled manner to, for example, reduce any additional stress on the function until the setting temperature is reached, at which temperature the functional foil is cooled to the finished shape without allowing any further stretching.

[0087] This method may include ending (and / or opening) the clamping of the placed functional foil between the foil holder and the thermoforming module by moving the thermoforming module away from the foil holder when the vacuum application has been stopped. The clamping may be ended when atmospheric pressure is reached above and below the functional foil and / or when atmospheric pressure is reached inside the foil holder and optionally inside the hot chamber. Advantageously, the clamping can be opened and the finished laminated optical element can be easily removed, wherein, as stated above, no additional clamping components are required to hold the functional foil in the intended position. Accordingly, it is not necessary to open and / or remove additional clamping components to remove the finished laminated optical element. As stated above, pressure adjustment can further simplify releasing the clamping (by moving the thermoforming module away from the foil holder), wherein, for example, no sudden pressure equalization occurs when the clamping is opened.

[0088] The method may include removing the (laminated) optical element after the clamping has ended (and / or been opened). Advantageously, at the end of the described method, the finished product is provided by simply removing the finished product (i.e., the laminated optical element) from the laminating device.

[0089] A suitable method for manufacturing spectacle lenses may further include adjusting the spectacle lenses for insertion into a spectacle frame, wherein adjusting the spectacle lenses for insertion into the spectacle frame is performed before or after laminating the functional foil onto the surface of the optical element.

[0090] This method can be adapted to manufacture spectacle lenses for stock, i.e., lenses not manufactured in response to a specific need for an individual's refractive value, but rather having a commonly sought-after prescription value. Such spectacle lenses manufactured for stock can then be supplied from stock to customers requesting lenses with such prescription values. Lamination applied to at least one surface and optionally both surfaces of the lens protects it from intrusion and contamination. The lenses can be supplied as finished spectacle lens products in an uncut manner, without pre-grinding. The at least one surface may include the front and / or back surface of the lens.

[0091] This method can be adapted to individually manufacture spectacle lenses for insertion into specific eyeglass frames. The lenses can be edged to fit the size of the eyeglass frame.

[0092] The functional foil can be made from a single layer or laminate of cellulose triacetate, polyethylene terephthalate, polycarbonate, polyvinyl alcohol, cyclic olefin polymers and / or cyclic olefin copolymers. Advantageously, the listed materials can be thermoformed while minimizing or avoiding any distortion and / or shrinkage, which is particularly beneficial for achieving the desired curvature of the functional foil during thermoforming.

[0093] The description of the lamination apparatus in this article applies similarly to this method, and vice versa.

[0094] Those skilled in the art will understand that the features described above, as well as those in the following description and accompanying drawings, are not only disclosed in the explicitly disclosed embodiments and combinations, but also include other technically feasible combinations and isolated features. Hereinafter, several alternative embodiments and specific examples are described with reference to the accompanying drawings to illustrate this disclosure, but not to limit this disclosure to the described embodiments.

[0095] The following is for reference Figures 1 to 6 Optional embodiments are described.

[0096] Figure 1 A schematic cross-sectional view of a lamination apparatus according to an embodiment of the present disclosure is shown, which includes a functional foil and optical elements held by the lamination apparatus; Figure 2 Another schematic cross-sectional view of the lamination device is shown, excluding the functional foil and optical elements; Figure 3 A schematic flowchart of a method according to an embodiment of this disclosure is shown; Figure 4 and Figure 5 The schematic diagram illustrates the principle steps of the method, wherein the surface of the optical element to be laminated has a concave or convex shape; and Figure 6 A method suitable for manufacturing eyeglass lenses is illustrated schematically.

[0097] Figure 1 and Figure 2 A schematic cross-sectional view of a lamination apparatus 1 for laminating a functional foil 20 onto the surface 31 of an optical element 30, according to an embodiment of this disclosure, is shown. The optical element 30 may be a spectacle lens, a lens blank, a semi-finished spectacle lens product, or a finished spectacle lens product.

[0098] The lamination device 1 includes a holding module 2 and a thermoforming module 5.

[0099] The holding module 2 includes a sleeve-shaped foil holder 3 that extends along a central longitudinal axis L and has an opening 6 at the upper longitudinal end 3.1 of the foil holder 3, wherein the upper longitudinal end 3.1 is configured to hold a functional foil 20.

[0100] The holding module 2 further includes an optical element holder 4 for holding the optical element 30, wherein the foil holder 3 surrounds the optical element holder 4. In other words, the optical element holder 4 is arranged inside the cavity of the foil holder 3, wherein the cavity is open on the upper side through an opening 6 at the longitudinal upper end 3.1. Accordingly, the foil holder 3 is configured to hold the functional foil 20, and the optical element holder 4 is configured to hold the optical element 30 such that the optical element 30 is arranged at a certain distance below the functional foil 20 with its surface 31 facing the functional foil 20.

[0101] The optical element holder 4 can move at an adjustable speed along the central longitudinal axis L inside the foil holder 3.

[0102] The holding module 2 and the thermoforming module 5 are arranged along the central longitudinal axis L, such that the lower longitudinal end 5.1 of the thermoforming module 5 and the upper longitudinal end 3.1 of the foil holder 3 face each other.

[0103] The thermoforming module 5 can move along the central longitudinal axis L to adjust the distance between the lower longitudinal end 5.1 of the thermoforming module 5 and the upper longitudinal end 3.1 of the foil holder 3.

[0104] The thermoforming module 5 includes at least one air channel 7 for providing an airflow with controlled temperature and controlled pressure, wherein the at least one air channel 7 is arranged at the lower longitudinal end 5.1 of the thermoforming module 5. The thermoforming module 5 and / or at least one air channel 7 may be configured to provide an airflow guided downward along the central longitudinal axis L, particularly guided toward the opening 6 at the upper longitudinal end 3.1 of the foil holder 3.

[0105] The foil holder 3 includes at least one vacuum channel 8. The laminating apparatus 1 includes a vacuum pump 9 connected to at least one vacuum channel 8 for applying a vacuum inside the foil holder 3.

[0106] The laminating apparatus 1 may include a control unit 10 for controlling the thermoforming module 5 and the vacuum pump 9. In the operating state of the laminating apparatus 1, the control unit 10 may be configured to control the thermoforming module 5 to provide an airflow with controlled temperature and controlled pressure, and simultaneously activate and / or control the vacuum pump 9 to apply a vacuum inside the foil holder 3.

[0107] The holding module 2 may include a guide element 15 for guiding the optical element holder 4, the guide element being located inside the foil holder 3, that is, inside the cavity of the foil holder 3. The guide element 15 may be sleeve-shaped and extend along the central longitudinal axis L, wherein the optical element holder 4 may be partially (and movably) arranged inside the guide element 15.

[0108] The upper longitudinal end 4.1 of the optical element holder 4 can be configured to hold the optical element 30 such that the surface 31 of the optical element 30 is arranged away from the upper longitudinal end 4.1 of the optical element holder 4 and / or facing the opening 6 of the foil holder 3.

[0109] The upper longitudinal end 3.1 of the foil holder 3 can be configured to hold the functional foil 20 such that the portion of the functional foil 20 to be laminated onto the surface 31 of the optical element 30 is arranged above the opening 6 and / or the opening 6 is closed by the functional foil 20.

[0110] The thermoforming module 5 can move along the central longitudinal axis L to clamp the functional foil 20 between the lower longitudinal end 5.1 of the thermoforming module 5 and the upper longitudinal end 3.1 of the foil holder 3 when the laminating device 1 is in operation.

[0111] The thermoforming module 5 may further include a hot chamber 11 fluidly connected to at least one air passage 7, and at least one air inlet 12 for supplying air to the hot chamber 11. The thermoforming module 5 may further include a heating element 13 disposed within the hot chamber 11, wherein the heating element 13 may be configured to heat the air supplied by the at least one air inlet 12 to achieve a controlled temperature. The control unit 10 may be configured to control the heating element 13.

[0112] Alternatively, the thermoforming module 5 may further include a thermocouple 14 disposed inside the hot chamber 11, wherein the thermocouple 14 may be configured to measure the temperature of air heated by the heating element in order to determine when the air has reached a controlled temperature.

[0113] The thermoforming module 5 may further include a cooling unit (not shown in the figure) for providing a controlled cooling process and / or for cooling airflow to achieve a controlled temperature.

[0114] The thermoforming module may further include a pressure unit (not shown in the figures) for providing controlled pressure to the airflow. The pressure unit may be disposed within the hot chamber 11 and / or at least one air passage 7. Alternatively or additionally, the laminating device 1 may include an air pressure unit (not shown) (e.g., an air pump) for providing controlled pressure to air, wherein the air pressure unit may be fluidly connected to the thermoforming module 5, for example, fluidly connected to at least one air inlet 12, for supplying air (e.g., airflow) with controlled pressure to the hot chamber 11. The control unit 10 may be configured to control the pressure unit and / or the air pressure unit.

[0115] The foil holder 3 may include a window 16 for observing the optical element 30 and / or the functional foil 12. The window 16 may be arranged adjacent to the longitudinal upper end 3.1 of the foil holder 3.

[0116] Figure 3 A method 100 is shown for optionally laminating a functional foil 20 onto the surface 31 of an optical element 30 using a laminating apparatus 1.

[0117] In the first step S1, (for example) the optical element 30 is placed on the optical element holder 4 of the laminating device 1 through the opening 6.

[0118] In the second step S2, the functional foil 20 is placed on the foil holder 3 of the laminating apparatus 1. In steps S1 and S2, the functional foil 20 and the optical element 30 are positioned such that the optical element 30 is arranged at a certain distance below the functional foil 20 with its surface 31 facing the functional foil 20.

[0119] The functional foil 20 may be made of a single layer or laminate of cellulose triacetate, polyethylene terephthalate, polycarbonate, polyvinyl alcohol, cyclic olefin polymers and / or cyclic olefin copolymers.

[0120] The functional foil may include a pressure-sensitive adhesive coated on one side of the functional foil, wherein the functional foil 20 may be placed on the foil holder 3 with one side of the functional foil facing the surface 31 of the optical element 30.

[0121] In the optional third step S3, the placed functional foil 20 can be clamped between the foil holder 3 and the thermoforming module 5 by moving the thermoforming module 5 of the laminating device 1 toward the foil holder 3.

[0122] In the fourth step S4, an airflow with controlled temperature and controlled pressure is provided above the placed functional foil 20. The controlled temperature may correspond to the glass transition temperature of the functional foil 20 or a higher temperature.

[0123] In the fifth step S5, a vacuum is applied below the placed functional foil 20 simultaneously with the provision of airflow.

[0124] In the sixth step S6, before the functional foil 20 is arranged onto the surface 31 of the optical element 30, the controlled pressure of the airflow is adjusted and / or temporarily increased until the functional foil is stretched into a spherical shape with a radius smaller than the radius of the central region of the optical element 30. The functional foil can be stretched such that the radius of the spherical shape can be in the range of 40 mm to 80 mm.

[0125] In the seventh step S7, while providing an airflow and applying a vacuum, the functional foil 20 is arranged onto the surface 31 of the optical element 30. To do this, the optical element 30 can be moved upward toward the functional foil 20 at an adjustable speed by moving the optical element holder 4 until the central region of the optical element 30 first contacts the curved functional foil 20, and then the functional foil 20 is arranged onto the surface 31. For example, the optical element 30 can be moved until the surface 31 is positioned at or inside the opening 6.

[0126] In the optional eighth step S8, after the functional foil 20 is arranged on the surface 31 of the optical element 30, the controlled temperature can be reduced to the shaping temperature of the functional foil 20.

[0127] In the optional ninth step S9, when the setting temperature is reached, the vacuum application can be stopped, for example, by decompressing the interior of the foil holder 3. Alternatively, the airflow can be stopped, or the controlled pressure can be set to atmospheric pressure.

[0128] Then, for example, when atmospheric pressure is reached above and below the functional foil 20 and / or when atmospheric pressure is reached inside the foil holder 3 and the hot chamber 11, the clamping of the placed functional foil 20 between the foil holder 3 and the thermoforming module 5 can be terminated by moving the thermoforming module 5 away from the foil holder 3.

[0129] Finally, the laminated optical element 30 can be removed from the laminating device 1, for example, through the opening 6.

[0130] Figure 4 The principle steps of method 100 are shown, wherein the surface 31 of the optical element 30 has a concave shape.

[0131] exist Figure 4 In (a), a functional foil 20 is shown, wherein the functional foil 20 includes a pressure-sensitive adhesive 21 coated on one side of the functional foil 20. Additionally, the functional foil 20 is disposed on a release film 22, wherein the release film 22 is disposed on a second side of the functional foil 20 opposite to the pressure-sensitive adhesive 21. As an alternative to or supplement to the pressure-sensitive adhesive 21, the functional foil 20 may include an optical adhesive.

[0132] The functional foil is placed on the foil holder 3 with the side of the functional foil 20 having the pressure-sensitive adhesive 21 facing the surface 31 of the optical element 31, and with the second side of the functional foil 20 and therefore the release film 22 facing away from the optical element 30.

[0133] Figure 4 (b) illustrates an airflow with controlled temperature and controlled pressure provided above the placed foil holder 3 toward the functional foil 20 (shown by three downward-pointing arrows). Due to the airflow, the functional foil 20 is stretched and / or bent into a spherical shape until the desired curvature of the functional foil 20 is achieved. The desired curvature may include a radius smaller than the radius of the central region of the optical element 30 (e.g., 40 mm to 80 mm).

[0134] Simultaneously with providing airflow above the functional foil 20, a vacuum is applied below the functional foil 20, for example, between the functional foil 20 and the optical element 30, thereby creating a vacuum or at least negative air pressure in the region between the functional foil 20 and the optical element 30 (indicated by two arrows arranged on the left and right sides of the optical element 30). The vacuum prevents air trapping between the functional foil 20 and the optical element 30 and provides uniform bending force.

[0135] While providing airflow and applying vacuum, the functional foil 20 is arranged on the surface 31 of the optical element 30, wherein pressure-sensitive adhesive is pressed onto the surface 31 to maintain the functional foil 20 on the surface 31.

[0136] Figure 4(c) shows the removal of the release film 22 from the functional foil 20 after the functional foil 20 has been arranged and laminated onto the surface 31.

[0137] Figure 5 Another illustration shows the principle steps of method 100, which are similar to... Figure 4 The two are basically the same, except that the surface 31 of the optical element 30 has a different form, namely a convex form.

[0138] Figure 4 and Figure 5 The form of surface 31 shown is merely exemplary, as method 100 can be performed on any free-form surface 31. In other words, method 100 and laminating apparatus 1 can be used to laminate functional foil onto a surface having any form, and are not limited to convex or concave surfaces.

[0139] Figure 6 A method 600 suitable for manufacturing eyeglass lenses is schematically depicted.

[0140] Method 600 includes: laminating 602 of functional foil 20 onto surface 31 of optical element 30 using method 100 according to the present disclosure, wherein optical element 30 is a spectacle lens to be manufactured, or a lens blank, semi-finished lens blank, or uncut finished lens from which the spectacle lens is manufactured.

[0141] The method may further include: adjusting the 604 spectacle lens to insert it into the eyeglass frame, wherein adjusting the 604 spectacle lens to insert it into the eyeglass frame is performed before or after laminating the functional foil 602 onto the surface of the optical element.

[0142] List of reference numerals 1. Lamination device 2. Holding Module 3. Foil Holder 3.1 Upper longitudinal end of the foil holder 4 Optical component holder 4.1 Upper longitudinal end of the optical element holder 5. Thermoforming Module 5.1 Lower longitudinal end of the thermoforming module 6 Openings 7. Air passage 8 Vacuum Channels 9. Vacuum pump 10 Control Unit 11. Hot Chamber 12 Air Inlets 13 Heating elements 14. Thermocouple 15 Guiding elements 16 windows 20 Functional Foil 21 Pressure-sensitive adhesives 22 Release film 30 Optical components / eyeglass lenses 31. Surface of optical elements L center longitudinal axis 100 methods S1-S9 Method Steps 600. Methods suitable for manufacturing eyeglass lenses. Methods and steps 602-604.

Claims

1. A lamination apparatus (1) for laminating a functional foil (20) onto the surface (31) of an optical element (30), wherein, The lamination device (1) includes: - Holding module (2), the holding module includes: - A sleeve-shaped foil holder (3) extending along a central longitudinal axis (L) and having an opening (6) at its longitudinal upper end (3.1), wherein the longitudinal upper end (3.1) is configured to hold the functional foil (20), and - An optical element holder (4) for holding the optical element (30), wherein the foil holder (3) surrounds the optical element holder (4); and - A thermoforming module (5) including at least one air channel (7) for providing an airflow with controlled temperature and controlled pressure, wherein the at least one air channel (7) is arranged at the lower longitudinal end (5.1) of the thermoforming module (5), wherein, - The holding module (2) and the thermoforming module (5) are arranged along the central longitudinal axis (L) such that the lower longitudinal end (5.1) of the thermoforming module (5) and the upper longitudinal end (3.1) of the foil holder (3) face each other, and - The thermoforming module (5) is movable along the central longitudinal axis (L) to adjust the distance between the lower longitudinal end (5.1) of the thermoforming module (5) and the upper longitudinal end (3.1) of the foil holder (3). Its features are, - The foil holder (3) includes at least one vacuum channel (8); - The laminating device (1) includes a vacuum pump (9) connected to the at least one vacuum channel (8) for applying a vacuum inside the foil holder (3); and - The optical element holder (4) is able to move at an adjustable speed along the central longitudinal axis (L) inside the foil holder (3).

2. The laminating apparatus (1) according to claim 1, characterized in that, The lamination device (1) includes: - Control unit (10) for controlling the thermoforming module (5) and the vacuum pump (9), wherein, in the operating state of the laminating device (1), the control unit (10) is configured to control the thermoforming module (5) to provide the airflow having the control temperature and the control pressure, and simultaneously enable the vacuum pump (9) and / or control the vacuum pump (9) to apply a vacuum inside the foil holder (3).

3. The laminating apparatus (1) according to claim 1 or 2, characterized in that, The upper longitudinal end (4.1) of the optical element holder (4) is configured to hold the optical element (30) such that the surface (31) of the optical element (30) is arranged to face away from the upper longitudinal end (4.1) of the optical element holder (4) and / or to face the opening (6) of the foil holder (3).

4. The laminating apparatus (1) according to any one of claims 1 to 3, characterized in that, The upper longitudinal end (3.1) of the foil holder (3) is configured to hold the functional foil (20) such that the portion of the functional foil (20) to be laminated onto the surface (31) of the optical element (30) is arranged above the opening (6) and / or the opening (6) is closed by the functional foil (20).

5. The laminating apparatus (1) according to any one of claims 1 to 4, characterized in that, The thermoforming module (5) is movable along the central longitudinal axis (L) to hold the functional foil (20) between the lower longitudinal end (5.1) of the thermoforming module (5) and the upper longitudinal end (3.1) of the foil holder (3) in the operating state of the laminating device (1).

6. The laminating apparatus (1) according to any one of claims 1 to 5, characterized in that, The thermoforming module (5) further includes: - A hot chamber (11) fluidly connected to the at least one air passage (7); - At least one air inlet (12) for supplying air to the hot chamber (11); and - A heating element (13) arranged inside the hot chamber (11), wherein the heating element (13) is configured to heat the air supplied by the at least one air inlet (12) to achieve the controlled temperature.

7. The laminating apparatus (1) according to any one of claims 1 to 6, characterized in that, The thermoforming module (5) further includes: - A cooling unit for providing a controlled cooling process and / or for cooling the airflow to achieve the controlled temperature.

8. A method (100) for laminating a functional foil (20) onto the surface (31) of an optical element (30), wherein, The method (100) includes: - Place (S1) the optical element (30) on the optical element holder (4) of the laminating device (1); - The functional foil (20) is placed (S2) on the foil holder (3) of the laminating apparatus (1), wherein the functional foil (20) and the optical element (30) are positioned such that the optical element (30) is positioned at a certain distance below the functional foil (20) with the surface (31) of the optical element (30) facing the functional foil (20); and - An airflow with controlled temperature and controlled pressure is provided (S4) above the placed functional foil (20). - Simultaneously with providing the airflow, a vacuum (S5) is applied below the placed functional foil (20); and - While providing the airflow and applying the vacuum, the functional foil (20) is arranged (S7) onto the surface (31) of the optical element (30). The method (100) is characterized by comprising: - Before the functional foil (20) is placed on the surface (31) of the optical element (30), the controlled pressure of the airflow is adjusted and / or temporarily increased (S6) until the functional foil is stretched into a spherical shape with a radius smaller than the radius of the central region of the optical element (30).

9. The method according to claim 8, wherein, The radius of the spherical shape of the stretched functional foil is in the range of 40 mm to 80 mm.

10. The method (100) according to claim 8 or 9, characterized in that, - The functional foil (20) includes a pressure-sensitive adhesive (21) and / or optical adhesive coated on one side of the functional foil, wherein the functional foil (20) is placed (S2) on the foil holder (3) with one side of the functional foil facing the surface (31) of the optical element (30), and / or - The optical element (30) includes pressure-sensitive adhesive and / or optical glue coated on the surface (31) of the optical element (30).

11. The method (100) according to any one of claims 8 to 10, characterized in that, The method (100) includes: - The placed functional foil (20) is clamped (S3) between the foil holder (3) and the thermoforming module (5) by moving the thermoforming module (5) of the laminating device (1) toward the foil holder (3).

12. The method (100) according to any one of claims 8 to 11, characterized in that, The controlled temperature corresponds to the glass transition temperature of the functional foil (20) or a higher temperature.

13. The method (100) according to any one of claims 8 to 12, characterized in that, The method (100) includes: - After the functional foil (20) is arranged on the surface (31) of the optical element (30), the controlled temperature is lowered (S8) to the shaping temperature of the functional foil (20); and - Stop applying the vacuum when the shaping temperature is reached (S9).

14. The method (100) according to any one of claims 8 to 13, characterized in that, The functional foil (20) is made of a single layer or laminate of cellulose triacetate, polyethylene terephthalate, polycarbonate, polyvinyl alcohol, cyclic olefin polymers and / or cyclic olefin copolymers.

15. The method (100) according to any one of claims 8 to 14, wherein, The optical element is a spectacle lens, or a lens blank, or a semi-finished spectacle lens product, or a finished spectacle lens product.

16. A method (600) suitable for manufacturing spectacle lenses, characterized in that the method comprises: - The functional foil (20) is laminated (602) onto the surface (31) of the optical element (30) using the method (100) according to any one of claims 8 to 15, wherein the optical element (30) is a spectacle lens to be manufactured, or a lens blank, semi-finished lens blank or uncut finished lens from which the spectacle lens is manufactured.

17. The method (600) of claim 16, further comprising: - Adjust (604) the lens to insert it into the eyeglass frame, wherein the adjustment (604) of the lens to insert it into the eyeglass frame is performed before or after the functional foil is laminated (602) onto the surface of the optical element.

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