Method and apparatus for applying optical markings to spectacle lenses

Abstract

Embodiments of the invention relate to a method for applying an optical marking (30) to an ophthalmic lens (12) mounted in an eyeglass frame (14). The method comprises determining an expected position of the optical marking (30) at the ophthalmic lens (12) based on the eyeglass frame (14), including taking an image of at least a portion of the eyeglass frame (14), and arranging the eyeglass frame (14) in a marking device (10) having a marking tool (18) and adjusting the relative position of the eyeglass frame (14) and the marking tool (18) such that an actuation axis (104) of the marking tool (18) intersects the ophthalmic lens (12) at the expected position of the optical marking (30). The method further comprises applying the optical marking (30) at the expected position of the ophthalmic lens (12) by using the marking tool (18). Further embodiments of the invention relate to a use of an eyeglass frame as a positioning reference for an optical marking (30), and a marking device (10).

Description

[0001] Embodiments of the present invention relate to a method for applying optical markings to an ophthalmic lens mounted in a spectacle frame, to the use of a spectacle frame as a positioning reference, and to a marking device. The invention thus relates to the field of ophthalmic lenses and ophthalmic lens manufacturing processes.

[0002] Conventional ophthalmic lenses can exhibit optical markings which help to align and process the ophthalmic lenses during the manufacturing process and / or the shaping process when the ophthalmic lenses are cut to the correct shape for insertion into a spectacle frame. Such optical markings are referred to as orientation markings, typically engraved into the ophthalmic lens, in particular into the anti-reflective coating of the ophthalmic lens. Typically, all individual ophthalmic lenses manufactured according to specific prescription data for a specific customer are provided with such orientation markings to allow the ophthalmic lenses to be oriented and mounted precisely and reliably in the intended spectacle frame. In addition, further optional permanent optical markings can be provided which can provide information about the prescription data of the ophthalmic lens, such as its spherical power and / or cylindrical power and / or cylindrical axis orientation and / or its prismatic power. These permanent engravings remain in the ophthalmic lens in the finished spectacle. Since these permanent engravings are typically implemented in the form of laser engravings in the anti-reflective coating of the ophthalmic lens, they do not significantly affect the usability of the ophthalmic lens. Rather, such permanent markings are more or less visible when the ophthalmic lens is illuminated with light of a predetermined angle and / or specific wavelength, but they do not affect the usability of the ophthalmic lens when worn by the customer. These permanent orientation markings can also be useful when determining the orientation of the ophthalmic lens in the spectacle frame after the ophthalmic lens has been mounted, which can facilitate replacing a damaged ophthalmic lens with a new ophthalmic lens having the same properties, in particular the same orientation in the spectacle frame. The orientation markings generally indicate a center point and thus the optical axis as well as the azimuth axis, which can be particularly useful for ophthalmic lenses having a cylindrical power. The orientation markings are typically applied in accordance with international standards.

[0003] In addition, further non-permanent optical markings are known in the prior art which can be used to shape the ophthalmic lens to fit in the intended spectacle frame during the manufacturing process and / or the shaping process, but which can be removed from the ophthalmic lens after the manufacturing and shaping have been completed. Such non-permanent markings can be used to indicate specific points of interest of the ophthalmic lens, such as the transmission points of the ophthalmic lens which are respectively intended for distance vision and near vision. For example, such non-permanent optical markings can be applied by a printing process.

[0004] In many cases, it can be desirable to add additional optical markings at specific locations of the spectacle lens. These specific locations can be identified with respect to permanent orientation markings, which indicate, inter alia, a center point of the spectacle lens. Thus, when knowing the shaping data for shaping the spectacle lens according to the requirements of the intended spectacle frame, additional optical markings can be applied at predetermined locations with respect to the spectacle frame before the spectacle lens is shaped and mounted into the spectacle frame. This positioning requires the permanent orientation markings as a positioning reference.

[0005] However, many spectacle lenses with a single and uniform refractive power are not provided with the above-described orientation markings. Such spectacle lenses do not necessarily require orientation markings, since their refractive power is independent of their orientation and exact point of transmission. Thus, shaping and mounting such spectacle lenses does not require an accurate positioning and orientation of the spectacle lenses. Accordingly, such spectacle lenses are usually not provided with orientation markings to avoid unnecessary manufacturing effort. However, the absence of orientation markings hinders the application of optical markings at predetermined locations with respect to the intended spectacle frame, since no orientation markings are available as a positioning reference.

[0006] US 2011 / 157549 A1 describes a visual deviation measurement method, which comprises forming reference markings indicating a distance eye point on a surface of a spectacle lens attached to a spectacle frame actually worn by a wearer. US 2013 / 000499 A1 describes a marking apparatus for a spectacle lens, which comprises a printing data generating device. DE 100 50 263 A1 describes a method for marking the surface of an optical element using ultraviolet light. US 2013 / 335694 A1 describes personalized spectacles with textured areas on the frame or lens, which include text.

[0007] The document "Software, Vision and Workflow Overview: High Performance Laser Marking Software with Laser Integrated Vision Alignment and Inspection Tools for the Simplest, Most Complete Laser Marking Process Solution" by Foba (10 January 2019, retrieved from URL: http: / / h2b-laser.com / wp-content / uploads / 2019 / 01 / FOBA-SW-and-Vision-Overview_EN_12.18-3.pdf) describes a laser marking solution which comprises a camera system for positioning and aligning a mark.

[0008] The document "Laser marking at a glance" by Trumpf (3 December 2020, retrieved from URL: https: / / www.trumpf.com / filestorage / TRUMPF_Master / Applications / Brosc hueres / TRUMPF-laser-marking-Booklet-EN_01.pdf) describes a laser marking and engraving solution.

[0009] The objective technical problem of the present invention is thus to provide a method and a device allowing to reliably and independently apply an optical mark to an ophthalmic lens.

[0010] This problem is solved by the method, the use and the marking device having the features of the respective independent claims. Preferred embodiments are presented in the dependent claims and the description.

[0011] A first embodiment of the present invention relates to a method for applying an optical mark to an ophthalmic lens mounted in an eyewear frame. The method comprises determining an expected position of the optical mark at the ophthalmic lens based on the eyewear frame, including taking an image of at least a portion of the eyewear frame. The method further comprises arranging the eyewear frame in a marking device having a marking appliance and adjusting the relative position of the eyewear frame and the marking appliance such that an actuation axis of the marking appliance intersects the ophthalmic lens at the expected position of the optical mark. In addition, the method comprises applying the optical mark to the expected position of the ophthalmic lens by using the marking appliance.

[0012] Another embodiment of the present invention relates to a use of an eyewear frame as a positioning reference for an optical marking to be applied to an ophthalmic lens mounted in the eyewear frame.

[0013] Another embodiment of the present invention relates to a marking device for applying an optical marking to an ophthalmic lens mounted in an eyewear frame. The marking device comprises a support element for adjustably arranging the eyewear frame in the marking device and an image capturing unit for taking an image of at least a portion of the eyewear frame surrounding the ophthalmic lens. Further, the marking device comprises a marking instrument for applying the optical marking to the ophthalmic lens at a position intersecting an actuation axis of the marking instrument. The marking device further comprises a control unit for determining an intended position of the optical marking at the ophthalmic lens based on the eyewear frame and for controlling the support element to arrange the eyewear frame such that the actuation axis of the marking instrument intersects the ophthalmic lens at the intended position of the optical marking.

[0014] The optical marking is a marking provided in and / or at the ophthalmic lens, which can be visible to the human eye. Optionally, the optical marking is adapted not to affect the optical properties and usability of the ophthalmic lens. The optical marking can be printed onto the ophthalmic lens. Alternatively or additionally, the optical marking can be engraved in the ophthalmic lens, in particular in an anti-reflective coating of the ophthalmic lens. Optionally, engraving the optical marking in the anti-reflective coating is such that layers below the anti-reflective coating, such as a protective coating, are not altered by the engraved optical marking. Engraving can be applied by laser engraving and / or mechanical engraving. The optical maker can also combine a printing portion and an engraving portion.

[0015] The intended position of the optical marking at the ophthalmic lens is a position at which the optical marking is expected to be applied. The intended position can be predetermined and can be based on technical requirements and / or standards and / or based on aesthetic and / or branding requirements.

[0016] Determining the intended position of the optical marking based on the eyewear frame means that the eyewear frame or a portion thereof is directly or indirectly used as a positioning reference. Directly using the eyewear frame as a positioning reference can include determining the intended position at a predetermined position relative to specific discernible markings of the eyewear frame, such as corners and / or edges of the eyewear frame. Within the meaning of the present specification, the eyewear frame does not necessarily include a physical frame, such as an element made of metal and / or plastic material surrounding the ophthalmic lens. Rather, for so-called rimless eyewear, the surrounding edge of the respective ophthalmic lens can be considered as the eyewear frame.

[0017] Arranging the spectacle frame in the marking device means that the spectacle frame is set in the marking device for processing by the marking device. The marking device does not necessarily need to enclose the spectacle frame. Rather, it is sufficient that the marking device supports the spectacle frame, thereby allowing the position of the spectacle frame relative to the marking appliance to be fixed and adjusted.

[0018] The actuation axis of the marking appliance is the axis along which actuation is performed to apply the optical marking. This actuation axis can be different from any dimension axis of the marking appliance. In case the marking appliance comprises a laser engraving device, the actuation axis can correspond to the optical axis of the laser beam used for performing the laser engraving. In this case, the actuation axis can be deflected, folded and / or bent. In case the marking appliance comprises a printing device, the actuation axis can correspond to the central axis of the printing jet.

[0019] An advantage provided by embodiments of the present application is that the optical marking can be applied to the spectacle lens independently of any other available optical marking. In other words, embodiments of the present application allow the optical marking to be applied to the spectacle lens without the need for the orientation marking to serve as a positioning reference. This allows the optical marking to be applied also to such spectacle lenses that do not have an orientation marking, such as spectacle lenses that have only a single and uniform spherical power. Accordingly, embodiments of the present application allow the optical marking to be applied at predetermined positions to a wide variety of spherical lenses that do not exhibit an orientation marking or any other marking providing a positioning reference. Thus, embodiments of the present application allow the optical marking to be applied also to such spectacle lenses that cannot conventionally be provided with the optical marking at the predetermined, intended positions.

[0020] A further advantage provided by the present application is that the optical marking can be applied precisely at predetermined positions relative to the spectacle frame. Since the optical marking is applied while the spectacle lens is mounted in the spectacle frame, the positioning and / or orientation and / or size determination of the logo can be determined relative to the spectacle frame. This provides an advantage over conventional approaches, according to which the optical marking, such as an orientation marking, is applied during the manufacturing process, at a time when the form data of the intended spectacle frame can not yet be available.

[0021] Furthermore, the present application provides the advantage that information and / or branding and / or personalization can be added to the spectacle lens after the spectacle lens has already been mounted into the spectacle frame. The optical marking can be a symbol, a number, and / or a text element carrying information, in particular information about the spectacle lens, the spectacle lens manufacturer, and / or the spectacle lens customer. For example, the optical marking can indicate the refractive power, and / or the spherical power, and / or the cylindrical power, and / or the prismatic power, and / or the cylindrical axis orientation. As another example, the optical marking can indicate the manufacturer, and / or the manufacturing number, and / or the manufacturing date. Yet another example can be an optical marking indicating a manufacturer logo and / or a product logo to brand the spectacle lens and the resulting spectacle and / or to prevent or deter fraudulent copying. Thus, the present application provides a variety of options for branding and / or personalization of the spectacle lens and / or for protecting it from fraudulent copying.

[0022] According to an optional embodiment, the method further comprises adjusting the relative orientation of the spectacle lens and the marking appliance prior to applying the marking to the spectacle lens such that a surface normal of the spectacle lens at the intended position of the optical marking overlaps with the actuation axis of the marking appliance. The surface normal of the spectacle lens at the intended position of the optical marking overlapping with the actuation axis means that the actuation axis is perpendicular to a tangent of the surface of the spectacle lens intersecting the actuation axis. This allows to ensure that the marking appliance is directed perpendicularly to the intended position of the spectacle lens. The benefit of this is that, for a spectacle lens having a spherical front surface, the curvature of the front surface of the spectacle lens is concentrically curved at the position of the front surface of the spectacle lens where the actuation axis intersects the front surface of the spectacle lens. Accordingly, the depth profile of the front surface of the spectacle lens varies concentrically around the actuation axis. Thus, it can be avoided that the applied optical marking is asymmetric due to the depth profile of the front surface of the spectacle lens possibly being asymmetric. In particular, when using a focused laser beam to laser-engrave the optical marking, a depth profile that is symmetric around the actuation axis can be particularly advantageous to avoid that parts of the intended position of the optical marking are arranged outside a predetermined focal depth, thus outside a region of sufficient intensity to perform the laser-engraving process. In case of a printer that can have a diverging printing beam, avoiding such asymmetry can be beneficial to ensure a uniform distribution of the printing pigment. This applies with necessary modifications to the back surface of the spectacle lens when the back surface of the spectacle lens faces the marking appliance used to apply the optical marking to the back surface.

[0023] According to an optional embodiment, the method further comprises positioning the spectacle frame and the marking instrument relative to each other such that the expected position of the optical marking and the marking instrument are arranged at a predetermined distance from each other along the actuation axis, before applying the optical marking to the spectacle lens. This distance can refer to the distance of the marking instrument from the surface of the spectacle lens facing the marking instrument. This allows for precisely applying the optical marking to the spectacle lens. In particular, when using a focused laser beam for applying the optical marking by laser engraving, precisely controlling the distance can be advantageous to ensure that the surface of the spectacle lens where the optical marking is to be applied is within the depth of focus. This can be disadvantageous for performing the laser engraving process with a laser beam of sufficiently high intensity. Similarly, when using a printer for applying the optical marking, the distance can be equally crucial for achieving the expected printing resolution and pigment density.

[0024] Determining the expected position of the optical marking based on the spectacle frame comprises taking an image of at least a portion of the spectacle frame. Based on the image, the position of the spectacle frame can be determined, and the expected position of the optical marking at the spectacle lens can be determined relative to the position of the spectacle frame. Determining the expected position of the optical marking can be performed in a partially or fully automated manner, or manually by an operator. For example, the expected position of the optical marking can be determined based on the image being located at a predetermined distance from an interface between the edge of the spectacle frame and the spectacle lens. For example, a corner of the spectacle frame can be selected as a positioning reference to achieve a two-dimensional positioning. Optionally, one or more of the following parameters are determined based on the image: a box size of the spectacle frame encompassing the mounted spectacle lens; a center point of the spectacle lens mounted in the spectacle frame. These determined parameters can facilitate the automatic determination of the optical marking relative to the spectacle frame. The automatically determined expected position of the optical marking can be automatically set by the marking device used for applying the optical marking, or can be suggested to an operator by the marking device for approval or modification.

[0025] Determining the expected position of the optical marking is optionally performed in an automated manner based on an image of at least a portion of the spectacle frame. Determining the expected position of the optical marking can be further based on one or more of the following parameters: a box size of the spectacle frame encompassing the mounted spectacle lens; a center point of the spectacle lens mounted in the spectacle frame. These parameters can facilitate the process of determining the expected position of the optical marking, in particular when performed in an automated manner. The box size of the spectacle frame is a virtual rectangle encompassing the spectacle lens mounted in the spectacle frame. Each side of the virtual box touches a point of the spectacle frame that is furthest away at a respective side of the spectacle lens. Alternatively or additionally, an outer box size of the spectacle frame can be determined and used. For example, the box size of the spectacle frame can facilitate determining a center point of the spectacle lens, and / or other areas of the spectacle lens, such as areas associated with specific corners of the spectacle lens. In other words, these parameters can facilitate the automatic orientation for determining the expected position of the optical marking.

[0026] According to an optional embodiment, the method further includes applying a second optical mark to a second lens mounted in the eyeglass frame. The second optical mark may be the same as or different from the optical mark applied to the first lens. The position of the second optical mark may correspond to or deviate from the position of the first optical mark relative to the first lens. For example, the second optical mark may be applied to the second lens at a position that establishes symmetry between the two optical marks about the central axis and / or center point of the eyeglass frame. This provides the advantage that each of the two lenses mounted in the eyeglass frame can be individually marked with one or more optical marks in a single process.

[0027] According to an optional embodiment, applying a second optical mark to a second lens mounted in an eyeglass frame includes: determining a desired position of the second optical mark on the second lens based on the eyeglass frame, and adjusting the relative positions of the eyeglass frame and the marking device such that the actuation axis of the marking device intersects the second lens at the desired position of the second optical mark. The method according to this optional embodiment further includes applying the second optical mark to the desired position of the second optical mark on the second lens using the marking device. In other words, the method may include repositioning the eyeglass frame and / or the marking device such that the actuation axis of the marking device is transferred from the first lens to the second lens, i.e., the actuation axis intersects the second lens. The process of determining the desired position of the second optical mark can then be similar to or the same as the corresponding process applied to determining the desired position and applying the first optical mark. The advantage provided by this alternative embodiment is that the second optical mark can be applied to the second lens in a precise and reliable manner.

[0028] Optionally, the method further includes determining one or more of the following parameters: the central axis of the eyeglass frame and the center point of the eyeglass frame. These parameters characterize the eyeglass frame and can be used for manual or automatic orientation relative to the entire eyeglass frame. These parameters can be particularly helpful in determining the expected position of the second optical mark. Thus, according to an optional embodiment, determining the expected position of the second optical mark on the second lens can be based on the actual and / or expected position of the first optical mark on the first lens and the one or more determined parameters. This can facilitate the manual and / or automatic adjustment of the position of the second optical mark according to the position of the first optical mark. In particular, this can facilitate the establishment of symmetry between the first and second optical marks about the centerline of the eyeglass frame.

[0029] According to optional embodiments, applying the optical marker comprises one or more of the following applying steps: laser engraving at least a portion of the optical marker in the spectacle lens; mechanically engraving at least a portion of the optical marker in the spectacle lens; printing at least a portion of the optical marker on the spectacle lens. Laser engraving can be performed using a continuous wave and / or a pulsed laser source. For example, a femtosecond laser source can be used. Laser engraving can comprise locally burning one or more layers of the spectacle lens, in particular one or more layers at the front surface of the spectacle lens. For example, laser engraving can comprise locally burning at least a portion of an anti-reflective coating applied to the front surface of the spectacle lens. Laser engraving of the optical marker can optionally be performed such that the layers or substrate of the spectacle lens beneath the burned anti-reflective coating remain unchanged. This applies mutatis mutandis to mechanically engraving the optical marker. Printing the optical marker or at least a portion thereof to the spectacle lens can comprise locally applying a printing pigment to the spectacle lens. The applied printing pigment can locally change the transparency and / or reflectivity of the spectacle lens, and can thus be distinguished from the surrounding portions of the spectacle lens. The printed optical marker can have one or several colors. According to optional embodiments, the optical marker can comprise at least one portion engraved to the spectacle lens and a second portion printed to the spectacle lens.

[0030] It is emphasized that applying the optical marker to the spectacle lens can be performed to a surface of the optical marker facing the marking apparatus. This surface can be the front surface or the back surface of the respective spectacle lens. Which surface of the spectacle lens faces the marking apparatus can be selected by providing the respective orientation to the spectacle frame in the marking device. When applying the optical marker using laser engraving, the optical marker can alternatively or additionally be applied to a surface of the spectacle lens facing away from the mounting apparatus. This can be achieved by adjusting the focal position of the engraving laser at the surface of the spectacle lens facing away from the mounting apparatus.

[0031] The marking device further comprises an image capturing unit for taking an image of at least a portion of the spectacle frame that encloses the spectacle lens. The image capturing unit can comprise or consist of a camera, such as a digital camera. The spectacle frame can be imaged and recorded by the image capturing unit. The image taken by the image capturing unit can then be evaluated to identify the spectacle frame and / or one or more spectacle lenses mounted in the spectacle frame, and / or to determine the intended position of the one or more optical markings to be applied to the one or more spectacle lenses. The image taken by the image capturing unit can cover the entire spectacle frame, or only a portion of the spectacle frame. According to an optional embodiment, the image capturing unit only takes an image of such a portion of the spectacle frame that encloses one spectacle lens and, optionally, an area of the spectacle frame in which a center line and / or a center point of the spectacle frame is located. In order to capture the image, the relative position of the spectacle frame with respect to the image capturing system and, optionally, the marking appliance can be changed. For example, the spectacle frame can be moved with respect to the image capturing unit, and / or vice versa. According to another optional embodiment, the image capturing unit can be adapted to capture an image of the entire spectacle frame, or at least to capture an image of those portions of the spectacle frame that enclose both spectacle lenses mounted in the spectacle frame. This can make it unnecessary for relative movements between the spectacle frame and the image capturing unit to take place any more.

[0032] According to an optional embodiment, the control unit is configured to automatically determine the intended position of the optical marking at the spectacle lens based on an image taken by the image capturing unit of at least a portion of the spectacle frame. In other words, the image taken by the image capturing unit is provided to the control unit, which can then determine the intended position of the optical marking at the spectacle lens based on the provided image. This can be performed in an automated manner by the control unit. However, according to another optional embodiment, the image can be displayed to an operator, e.g. via a display unit, to manually determine the intended position of the optical marking.

[0033] According to an optional embodiment, the marking device comprises an alignment light source for emitting an alignment light beam to adjust the relative position and, optionally, the relative orientation of the spectacle frame and the marking appliance. For example, the reflection of at least a portion of the alignment light beam from a surface of the spectacle lens facing the alignment light source can be used for alignment purposes. For example, the position of the reflection at the spectacle lens can be indicative of the position at which the actuation axis intersects the spectacle lens. Alternatively or additionally, the direction in which the alignment light beam is reflected from the spectacle lens can be used to determine and / or adjust the orientation of the surface of the spectacle lens facing the alignment light source. According to an optional embodiment, adjusting the orientation of the spectacle lens can comprise adjusting the spectacle lens such that the reflection of the alignment light beam overlaps with the incident alignment light beam. Thereby, it can be achieved that the surface normal of the intended position of the optical marking at the spectacle lens overlaps with the optical axis of the alignment light source, which can be identical to the actuation axis.

[0034] The marking appliance is or comprises a device for applying a marking to an ophthalmic lens. The marking appliance can be considered as a marking actuator. The terms "marking actuator" and "marking appliance" can be used as synonyms throughout the disclosure. The marking appliance can comprise mechanical and / or non-mechanical means for applying a marking to an ophthalmic lens. According to optional embodiments, the marking appliance comprises at least one of the following elements: a laser for laser engraving, a mechanical actuator for mechanical engraving, a printer unit. This provides the marking device with the functionality to apply one or more optical markings by laser engraving, mechanical engraving and / or printing.

[0035] According to optional embodiments, the step of determining the expected position of the second optical marking at the second ophthalmic lens based on the eyewear frame comprises: taking an image of at least a portion of the first ophthalmic lens including the expected and / or actual position of the first optical marking at the first ophthalmic lens and of the eyewear frame surrounding the at least a portion of the first ophthalmic lens, and using the image to determine the expected position of the second optical marking. In other words, an image of the first ophthalmic lens and the surrounding eyewear frame or portion thereof can be taken so that the position of the first optical marking at the first ophthalmic lens can be determined relative to the eyewear frame. This information about the position of the first optical marking that is taken is then used to determine the expected position of the second optical marking at the second ophthalmic lens relative to the eyewear frame. This allows to ensure that the first optical marking and the second optical marking are positioned in a symmetrical and / or equivalent manner relative to the eyewear frame. Such a method can for example comprise providing a mirrored image of the taken image of the first optical marking and using the mirrored image to determine the expected position of the second optical marking. For example, the portion of the eyewear frame included in the mirrored image can at least partially virtually overlap with the corresponding portion of the eyewear frame surrounding the second ophthalmic lens. The expected position of the second optical marking relative to the eyewear frame surrounding the second ophthalmic lens can then be determined as corresponding to the virtual position of the first optical marking with reference to the virtual representation of the eyewear frame in the mirrored image.

[0036] It will be appreciated by those skilled in the art that the features described above, as well as features described and illustrated in the following description and drawings, are not necessarily mutually exclusive and can be applied alone or in various combinations with one another. In the following, several embodiments of the present application are described with reference to the attached drawings, which are used to illustrate the principles of the present application but are not intended to limit the application to the described embodiments.

[0037] Further optional embodiments will be described below with reference to the attached drawings. The drawings show:

[0038] Figure 1 : Marking device for applying optical markings to ophthalmic lenses mounted in an eyewear frame, according to optional embodiments.

[0039] Figure 2: several dimensions and parameters for determining an intended position of an optical marking relative to an ophthalmic lens mounted in a spectacle frame.

[0040] Figure 3A and Figure 3B : exemplary illustration of steps for determining an intended position of an optical marking at an ophthalmic lens relative to a spectacle frame.

[0041] In the drawings, identical reference signs refer to corresponding or similar features in different drawings.

[0042] Figure 1 A marking device 10 for applying an optical marking to an ophthalmic lens 12 mounted in a spectacle frame 14 is schematically depicted in a cross-sectional view according to an alternative embodiment. The marking device 10 comprises a support element 16 for receiving and supporting the spectacle frame 14 in the marking device 10, wherein the spectacle frame has been mounted with one or more ophthalmic lenses 12. The support element 16 is adapted to adjust the position and orientation of the spectacle frame 14 relative to the marking device 10. According to the presented embodiment, the support element 16 is capable of adjusting the position of the spectacle frame 14 in all three spatial dimensions (as indicated by arrows 100) and of adjusting the orientation relative to the marking device 10 via rotational movements around all three axes (as indicated by arrows 102) of these spatial dimensions. However, according to other embodiments, the support element 16 can only be capable of adjustments along one or two dimensions and / or around one or two axes of these spatial dimensions.

[0043] The marking device 10 further comprises a marking appliance 18 for applying the optical marking to the ophthalmic lens 12. The marking appliance 18 acts on the ophthalmic lens 12 along an actuation axis 104, which can be folded and / or deflected by one or more optical elements. According to the presented embodiment, the actuation axis 104 extends straight towards the ophthalmic lens 12. According to the presented embodiment, a mirror 20 is arranged between the marking appliance 18 and the spectacle frame 14 for alignment purposes, which can be removed from the actuation axis 104 after completion of the alignment process to not obstruct the marking appliance 18. The marking appliance 18 is adapted as a laser engraving device that emits a laser beam to engrave the optical marking in the ophthalmic lens. The marking appliance 18 can for example comprise a pulsed laser source for providing the laser engraving beam. The laser engraving beam can be focused to the ophthalmic lens 12.

[0044] Other embodiments can use a printer element as the marking appliance 18 to print the optical marking on the ophthalmic lens 12. Such embodiments can require a straight and not deflected actuation axis 104 to ensure that the printing pigment reaches the ophthalmic lens 12.

[0045] The marking device 10 further comprises an alignment light source 22 for emitting an alignment light beam 106. The alignment light beam 106 propagates towards the mirror 20 and, after reflection from the mirror 20, propagates reflected parallel to the actuation axis 104. The alignment light source 22 according to the presented embodiment is a ring-shaped light source arranged around the image capturing unit 24. This allows to provide the alignment light beam 106 emitted by the alignment light source 22 and to capture images of the spectacle lens 12 along the image capturing axis 108 concentrically to each other and, after reflection from the mirror 20, concentrically to the actuation axis 104. For example, the alignment light source 22 can comprise several LEDs arranged in a ring around the actuation axis 104. The alignment light beam 106 emitted by the alignment light source 22 can be imaged to the spectacle lens 12.

[0046] Furthermore, the image capturing unit 24 is arranged in the marking device 10 such that the inserted spectacle frame 14 is arranged fully or partially in the field of view of the image capturing unit 24. According to the presented embodiment, the mirror 20 is arranged between the image capturing device 24 and the spectacle frame 14. After completion of the alignment process using the alignment light source 22 and the image capturing unit 24, the mirror 20 can be rearranged or removed to be free of intersection with the actuation axis 104. For example, the image capturing unit 24 unit can be a digital camera or comprise a digital camera.

[0047] In addition, the marking device 10 comprises a control unit 26. The control unit 26 is configured to determine an intended position of the optical marking to be applied to the spectacle lens 12 based on the spectacle frame 14. This determination is performed based on the image(s) taken by the image capturing unit 24, which are provided to the control unit 26. The determination of the intended position can be performed in an automated manner by the control unit according to predetermined instructions or can be performed by an operator. At least in the latter case, the images taken by the image capturing unit 24 can be displayed to the operator via a display unit 28 in order to determine the intended position. The predetermined instructions for determining the intended position of the optical marking at the spectacle lens 12 can be provided as a relative position or a position range of the optical marking relative to the spectacle frame 14 or a recognizable part of the spectacle frame 14. For example, the predetermined instructions can define a certain distance from a specific corner and / or side and / or upper part of the spectacle frame 14. Furthermore, an intended orientation of the optical marking relative to the spectacle lens 12 and / or the spectacle frame 14 can be determined. For example, the upper side of the spectacle frame 14 and / or a surface of the support element 16 on which the upper side of the spectacle frame 14 rests can be used as an orientation reference to which the optical marking is oriented in a parallel manner or at a predetermined angle.

[0048] The control unit 26 is further configured to control the support element 16 to arrange the spectacle frame 14 such that the actuation axis 104 of the marking appliance 18 intersects the spectacle lens 12 at the intended position of the optical marking. The alignment light beam and its reflection from the spectacle lens 12 can be used for orientation. Controlling the support element 16 can be performed automatically by the control unit 26 and / or can be performed manually by an operator. The marking device 10 can have command input means, such as control knobs and / or control levers, allowing the operator to manually control the support element 16. The marking device 10 can be configured to determine the intended position of the optical marking automatically and in combination with manual control. For example, the control unit 26 can automatically determine the intended position of the optical marking based on and with reference to the spectacle frame 14 and control the support element 16 to position the spectacle frame at a position and optionally orientation in which the actuation axis 104 intersects the intended position of the optical marking at the spectacle lens 12. The marking device 10 can then suggest the automatically determined intended position of the optical marking to an operator, who can confirm the intended position of the optical marking to be applied, and / or can perform fine adjustments to the suggested intended position, or can discard the suggested intended position and determine the intended position manually.

[0049] When the intended position is set and / or confirmed, the marking appliance 18 can apply the optical marking at the intended position of the spectacle lens 12. According to the presented embodiment, a laser engraving light beam is emitted and focused to the intended position to engrave the optical marking in the spectacle lens. Optionally, the marking device 10 can be configured to automatically remove the mirror 20 before applying the optical marking to the spectacle lens 12.

[0050] Thereafter, the process can continue with applying a further marking to the same spectacle lens at a further intended position. Alternatively or additionally, the marking device can reposition the spectacle frame 14 to a different position and determine an intended position of a second optical marking at a second spectacle lens mounted in the spectacle frame, the second optical marking to be applied to the intended position. For example, the central axis of the spectacle frame 14 can have been automatically determined by the control unit 26 and can be used to determine the intended position of the second optical marking at the second spectacle lens 12. For example, the control unit 26 can be configured to use the support element 16 to move the spectacle frame 14 twice the determined horizontal distance of the position of the applied first optical marking from the central axis of the spectacle frame 14. This can result in the actuation axis 104 being located at or near the intended position of the second optical marking, which can be applied at an intended position symmetric to the position of the first optical marking when mirrored at the central axis of the spectacle frame 14. Optionally, the process for determining the intended position of the second optical marking based on the spectacle frame 14 and applying the second optical marking can be performed similarly or identically as previously applying the first optical marking. For this purpose, the mirror 20 can be automatically reinserted to reflect the alignment light beam 106 and to deflect the image capturing axis 108.

[0051] Figure 2 Several dimensions and parameters for determining the expected position of the optical marking 30 relative to the spectacle lens 12 mounted in the spectacle frame 14 are exemplarily indicated. Figure 2 A spectacle frame 14 with two spectacle lenses 12 mounted therein is shown in a schematic view. An optical marking 30 is applied to each of the spectacle lenses 12, which optical marking represents a logo of the manufacturer of the spectacle lens 12. The spectacle frame 14 is arranged with its upper side lying on the upper surface 16a of the support element 16. Thus, the upper surface 16 can serve as a reference position indicating the upper edge of the spectacle frame 14.

[0052] As can be seen in Figure 2 , a central axis 1000 of the spectacle frame 14 is indicated, which central axis extends perpendicular to the upper edge of the spectacle frame 14 between the nose pads 32 of the spectacle frame 14. Further, a box size 1002 of one of the spectacle lenses 12 is indicated as well as a respective center point 1004, which can be taken from the box size 1002. In addition, a diagonal 1006 can be taken from the box size 1002, allowing to define a corner of the spectacle lens 14 relative to the spectacle frame 14.

[0053] The instructions for determining the expected position of the optical marking 30 based on the spectacle frame can comprise setting a distance of a center or an edge of the optical marking 30 from an edge line and / or a bottom line and / or an upper line of the box size. For example, the instructions can define a distance 1008 of the optical marking from the edge line and / or a distance 1010 of the optical marking from the upper line. For example, the distances 1008 and 1010 can be set to 4 mm to determine the expected position of the optical marking 30 at the spectacle lens relative to the spectacle frame 14.

[0054] Figure 3A and Figure 3B Steps for determining the expected position of the optical marking 30 at the spectacle lens 12 relative to the spectacle frame 14 are exemplarily shown. The presented image is an image taken by the image capturing unit 24 as discussed with reference to Figure 1 To automatically and / or manually determine the expected position of the optical marking 30, a virtual indicator 34 can be displayed together with the taken image Figure 3A), which virtual indicator appears as a thin circle. The center of the virtual indicator 34 can correspond to the intersection of the actuation axis 104 with the spectacle lens 12. In addition, a virtual representation of the optical marker 30 can be displayed to visualize the optical marker 30 placed at the intended position of the current selection. The control unit and / or the operator can then control the support element 16 to change the position of the spectacle frame 14 and thereby adjust the intended position of the optical marker 30 to meet the predetermined conditions and / or instructions. The image taken by the image capturing unit 24 can be updated periodically or permanently to allow tracking of the changes while moving the spectacle frame 14 relative to the image capturing unit 24 and the actuation axis 104. Thus, Figure 3A The image presented in Fig. 6 corresponds to a superimposition of the taken image, the virtual indicator 34, and the virtual representation of the optical marker 30 to be applied.

[0055] When the intended position of the optical marker 30 is set, the marking device 10 can automatically adjust the orientation of the spectacle lens 12 relative to the actuation axis 104 or assist the operator in performing this task. According to this embodiment, the front surface of the spectacle lens 12 is oriented in such a way that the surface normal at the intersection of the actuation axis 104 with the front surface of the spectacle lens 12 overlaps with the actuation axis 104. In other words, the spectacle frame 14 is adjusted in such a way that the actuation axis 104 is perpendicular to the front surface of the spectacle lens 12 at their intersection. To achieve this orientation alignment, alignment beams 106 are used, the reflection of which can be seen in the image from the front surface of the spectacle lens 12. This circle composed of dots is emitted by the alignment light source 22. The best orientation can be achieved by adjusting the orientation of the spectacle frame 14 until the reflection of the alignment beams 106 overlaps with the virtual indicator 34. This can correspond to an orientation of the spectacle lens 12 in which the reflection of the alignment beams 106 is concentric with the incident alignment beams, which is the case when the alignment beams 106 are perpendicular to the front surface of the spectacle lens 12. Thus, by ensuring that the alignment beams 106 propagate along the actuation axis 104, a suitable alignment can be achieved.

[0056] According to an optional embodiment, the method can further comprise adjusting the distance between the marking appliance 18 and the intended position of the optical marker 30. This point can be particularly important when using a focused laser engraving beam, because the laser engraving can work best when the intended position of the optical marker 30 at the spectacle lens 12 lies within the focal depth, which can range only a few millimeters. Adjusting this distance can be controlled, for example, by using a mechanical spacer and / or a mechanical feeler gauge (not shown). This can allow determining the suitable distance of the spectacle lens 12 from the marking appliance 18 when the spectacle lens is in contact with said mechanical spacer and / or mechanical feeler gauge.

[0057] List of reference signs

[0058] 10 marking device

[0059] 12 spectacle lens

[0060] 14 spectacle frame

[0061] 16 support element

[0062] 18 marking appliance

[0063] 20 mirror

[0064] 22 alignment light source

[0065] 24 image capturing unit

[0066] 26 control unit

[0067] 28 display unit

[0068] 30 optical marker

[0069] 32 nose pad

[0070] 34 virtual indicator

[0071] 100 arrow indicating adjustability in spatial dimension

[0072] 102 arrow indicating rotational adjustability

[0073] 104 actuation axis

[0074] 106 alignment light beam

[0075] 108 image capturing axis

[0076] 1000 central axis of the spectacle frame

[0077] 1002 box size of the spectacle lens

[0078] 1004 center point of the spectacle lens

[0079] 1006 diagonal of the box size

[0080] 1008 distance between the optical marker and the edge line of the box size

[0081] 1010 distance between the optical marker and the upper line of the box size

Claims

1. A method for applying a first optical marking to a first spectacle lens mounted in a spectacle frame (14) and a second optical marking to a second spectacle lens mounted in the spectacle frame, the method being characterized in that it comprises: - determining in an automated manner an expected position of the first optical marking at the first spectacle lens based on the spectacle frame (14), including taking an image of at least a portion of the spectacle frame (14); - arranging the spectacle frame (14) in a marking device (10) having a marking instrument (18) and adjusting the relative position of the spectacle frame (14) and the marking instrument (18) so that an actuation axis (104) of the marking instrument (18) intersects the first spectacle lens at the expected position of the first optical marking; and - applying the first optical marking to the spectacle lens at the expected position by using the marking instrument (18); - applying the second optical marking to a second spectacle lens mounted in the spectacle frame (14), wherein applying the second optical marking to the second spectacle lens mounted in the spectacle frame (14) comprises: - taking an image of at least a portion of the first spectacle lens including the expected and / or actual position of the first optical marking at the first spectacle lens and of at least a portion of the spectacle frame (14) surrounding the first spectacle lens; - determining in an automated manner an expected position of the second optical marking at the second spectacle lens using the image of at least a portion of the first spectacle lens including the expected and / or actual position of the first optical marking at the first spectacle lens and of at least a portion of the spectacle frame surrounding the first spectacle lens; - adjusting the relative position of the spectacle frame (14) and the marking instrument (18) so that the actuation axis (104) of the marking instrument (18) intersects the second spectacle lens at the expected position of the second optical marking; and - applying the second optical marking to the second spectacle lens at the expected position of the second optical marking by using the marking instrument (18); wherein determining the expected position of the optical marking based on the spectacle frame (14) comprises determining one or more of the following parameters based on the image of at least a portion of the spectacle frame (14): a box size (1002) of the spectacle frame (14) encompassing the mounted spectacle lens; a center point (1004) of the spectacle lens mounted in the spectacle frame (14). Determining the expected position of the second optical marking at the second spectacle lens is based on a mirrored image using the taken image of at least a portion of the first spectacle lens including the expected and / or actual position of the first optical marking at the first spectacle lens and of at least a portion of the spectacle frame surrounding the first spectacle lens.

2. The method of claim 1, wherein, 3. The method according to claim 1 or 2, further comprising adjusting the relative orientation of the spectacle lens and the marking instrument (18) so that a surface normal of the spectacle lens at the expected position of the optical marking overlaps the actuation axis (104) of the marking instrument (18) before applying the optical marking to the spectacle lens. ​ 4. The method according to claim 1 or 2, further comprising positioning the spectacle frame (14) and the marking instrument (18) relative to each other before applying the optical mark to the spectacle lens such that the expected position of the optical mark and the marking instrument (18) are arranged at a predetermined distance from each other along the actuation axis (104).

5. The method of claim 1, wherein, Determining the expected position of the optical mark is performed automatically based on an image of at least a portion of the spectacle frame (14) and based on one or more of the following parameters: a box size (1002) of the spectacle frame (14) encompassing the mounted spectacle lens; a center point of the spectacle lens mounted in the spectacle frame (14).

6. The method of claim 1 or 2, wherein, The method further comprises determining one or more of the following parameters: a center axis (1000) of the spectacle frame (14), and a center point of the spectacle frame; And wherein determining the expected position of the second optical mark at the second spectacle lens is based on the position of the first optical mark at the first spectacle lens and on said one or more determined parameters.

7. The method of claim 1 or 2, wherein, Determining the expected position of the second optical mark at the second spectacle lens based on the spectacle frame (14) comprises taking an image of at least a portion of the first spectacle lens including the expected position of the first optical mark and of at least a portion of the spectacle frame (14) surrounding the first spectacle lens, and using the image to determine the expected position of the second optical mark.

8. A method for applying optical marks to a first spectacle lens and a second spectacle lens mounted in a spectacle frame (14), the method comprising: - capturing, using an image capturing unit, an image of at least a portion of the spectacle frame encompassing the first spectacle lens and the second spectacle lens mounted in the spectacle frame; - determining an expected position of a first optical mark at the first spectacle lens based on the spectacle frame (14), including evaluating the image captured by the image capturing unit; - arranging the spectacle frame (14) in a marking device (10) having a marking instrument (18) and adjusting the relative position of the spectacle frame (14) and the marking instrument (18) such that an actuation axis (104) of the marking instrument (18) intersects the first spectacle lens at the expected position of the first optical mark; and - applying the first optical mark to the spectacle lens at the expected position by using the marking instrument (18); - determining one or more of the following parameters: a center axis (1000) of the spectacle frame (14), and a center point of the spectacle frame (14); - applying a second optical mark to a second spectacle lens mounted in the spectacle frame (14), wherein applying the second optical mark to the second spectacle lens mounted in the spectacle frame (14) comprises: - determining an expected position of the second optical mark at the second spectacle lens based on the position of the first optical mark at the first spectacle lens and on at least one of the center axis (1000) of the spectacle frame and the center point of the spectacle frame (14); - adjusting the relative position of the spectacle frame (14) and the marking instrument (18) so that the actuation axis (104) of the marking instrument (18) intersects the second spectacle lens at the expected position of the second optical marking; and - applying the second optical marking to the second spectacle lens at the expected position of the second optical marking by using the marking instrument (18).

9. The method according to claim 8, further comprising adjusting the relative orientation of the spectacle lens and the marking instrument (18) so that the surface normal of the spectacle lens at the expected position of the optical marking overlaps the actuation axis (104) of the marking instrument (18) before applying the optical marking to the spectacle lens.

10. The method according to claim 8 or 9, further comprising positioning the spectacle frame (14) and the marking instrument (18) relative to each other so that the expected position of the first optical marking and the marking instrument (18) are arranged at a predetermined distance from each other along the actuation axis (104) before applying the optical marking to the first spectacle lens.

11. The method of claim 8 or 9, wherein, Determining the expected position of the first optical marking based on the spectacle frame (14) comprises determining one or more of the following parameters based on the image: a box size (1002) of the spectacle frame (14) encompassing the mounted first and second spectacle lenses; a center point (1004) of the first and / or second spectacle lens mounted in the spectacle frame (14).

12. The method of claim 11, wherein, Determining the expected position of the first optical marking based on the image of at least a portion of the spectacle frame (14) and based on one or more of the following parameters is performed automatically: a box size (1002) of the spectacle frame (14) encompassing the mounted first spectacle lens; a center point of the first spectacle lens mounted in the spectacle frame (14).

13. The method of claim 8 or 9, wherein, Determining the expected position of the second optical marking at the second spectacle lens based on the spectacle frame (14) comprises: taking an image of at least a portion of the first spectacle lens including the expected position of the first optical marking and of the spectacle frame (14) surrounding the at least a portion of the first spectacle lens, and using the image to determine the expected position of the second optical marking.

14. A marking device (10) for applying a first optical marking to a first spectacle lens mounted in a spectacle frame (14) and a second optical marking to a second spectacle lens mounted in the spectacle frame, the marking device (10) comprising: - a support element (16) for adjustably arranging the spectacle frame (14) in the marking device (10); - an image capturing unit (24) for taking an image of at least a portion of the spectacle frame (14) encompassing the first and second spectacle lenses mounted in the spectacle frame; - a marking instrument (18) for applying the first optical marking to the first spectacle lens and the second optical marking to the second spectacle lens at respective positions intersecting an actuation axis (104) of the marking instrument (18); and - a control unit (26) configured to: - capturing, using the image capturing unit, an image of at least a portion of the spectacle frame that surrounds the first spectacle lens and the second spectacle lens mounted in the spectacle frame; - determining an expected position of the optical marking at the spectacle lens, including evaluating the image captured by the image capturing unit; - controlling the support element (16) to arrange the spectacle frame (14) so that the actuation axis (104) of the marking appliance (18) intersects the spectacle lens at the expected position of the optical marking; - determining one or more of the following parameters: a central axis (1000) of the spectacle frame (14), and a center point of the spectacle frame (14); - determining an expected position of the second optical marking at the second spectacle lens based on the position of the first optical marking at the first spectacle lens and based on at least one of the central axis (1000) of the spectacle frame and the center point of the spectacle frame (14); and - adjusting the relative position of the spectacle frame (14) and the marking appliance (18) so that the actuation axis (104) of the marking appliance (18) intersects the second spectacle lens at the expected position of the second optical marking.

15. The marking device (10) according to claim 14, wherein The control unit (26) is configured to automatically determine the expected position of the optical marking at the spectacle lens based on the image of at least a portion of the spectacle frame (14) taken by the image capturing unit (24).

16. The marking device (10) according to any one of claims 14 to 15, further comprising an alignment light source (22) for emitting an alignment light beam (106) to adjust the relative position and optionally the relative orientation of the spectacle frame (14) and the marking appliance (18).

17. The marking device (10) according to any one of claims 14 to 15, wherein, The marking appliance (18) comprises at least one of the following elements: a laser for laser engraving, a mechanical appliance for mechanical engraving, a printer unit. The control unit (26) is configured to automatically determine the expected position of the optical marking at the spectacle lens based on the image of at least a portion of the spectacle frame (14) taken by the image capturing unit (24).

Images