Method for additive manufacturing of an ophthalmic device and manufacturing system configured to perform such a method

Abstract

The present disclosure provides a method for additive manufacturing of an ophthalmic device (2) to be worn by a wearer (60), the method comprising: additive manufacturing of a plurality of layers (3) of a predetermined material to obtain the ophthalmic device, and determining a build tilt angle such that when the wearer wears the ophthalmic device, diffracted rays (70) of a light beam (71) are directed on a specialized zone, the specialized region is located at least outside a visually useful region of the retina of the wearer's eye.

Description

Technical Field

[0001] The present disclosure relates to a method for additive manufacturing of ophthalmic devices and a manufacturing system configured to perform such a method.

[0002] The present disclosure also relates to a command and control unit comprising system elements configured to run a computer program to implement at least some steps of the additive manufacturing method; and to a manufacturing system comprising such a command and control unit and configured to perform such a method.

[0003] The present disclosure also relates to a computer program comprising instructions configured to implement additive manufacturing of such a method when the computer program is run by a computer; and to a client-server communication interface for transmitting at least manufacturing data to a remote computer, the manufacturing data being determined by a computer program implementing at least some parts of such a method, and when the computer program runs in the command and control unit, the remote computer implements other parts of such a method. Background Art

[0004] Known methods for additive manufacturing of ophthalmic lenses include curing steps and layering steps, which are successively performed in a manufacturing system comprising a curing device, a layering device, and a build platform positioned relative to a vat filled with a predetermined material.

[0005] For example, each ophthalmic lens is built layer by layer on a build platform that is movable relative to a vat containing a certain volume of a predetermined material. The build platform is located at a predetermined position, and a curing device including an irradiation source performs a curing step on a first layer of material, and the layering device performs a layering step at least in accordance with the displacement of the build platform such that a new layer of material having a predetermined thickness can be cured, and so on.

[0006] In other words, in such known methods, the curing step is performed on a layer that is, for example, a liquid for a plurality of ophthalmic lenses to be manufactured on the build platform. The liquid layer thus hardens, and then a layering step is performed to form a new liquid layer on the previously hardened layer of the plurality of ophthalmic lenses to be manufactured.

[0007] International Application WO 2015004383A1 discloses a method for additive manufacturing of optical articles, the method including the steps of providing an initial optical system and additively manufacturing a complementary optical element layer by layer on the initial optical element, the complementary optical element being able to be in an inclined position.

[0008] International Application WO 2015086981A1 discloses a method for layer-by-layer additive manufacturing of an optical article, the method comprising the steps of: additively manufacturing an intermediate optical element in such a way that the intermediate optical element is inclined with respect to a predetermined additive construction axis called a layering axis, and depositing a plurality of predetermined volume elements of at least one material along the layering axis so as to enable a polishing step to be carried out in a specific zone.

[0009] International Application WO 2018235209A1 discloses a method for layer-by-layer additive manufacturing of an optical article from a photocurable resin by using a micromirror device (e.g., a DMD (Digital Micromirror Device)) to generate a desired shaped light flux for irradiating the photocurable resin. The micromirror device has a plurality of micromirrors arranged in a two-dimensional repeating structure. In the process of photocuring the resin using a DMD, in the projection area of the photocurable resin, the intensity of the projected light in the part corresponding to the area of the micromirror itself is different from the intensity of the projected light in the part corresponding to the area between adjacent micromirrors. SUMMARY OF THE DISCLOSURE

[0010] The present disclosure relates to a method for additive manufacturing of an ophthalmic device, which is simple and convenient to implement.

[0011] Accordingly, the present disclosure provides a method for additive manufacturing of an ophthalmic device to be worn by a wearer, the method comprising: additively manufacturing a plurality of layers of a predetermined material to obtain the ophthalmic device, and determining a build tilt angle such that when the wearer wears the ophthalmic device, diffractive light rays interfering with the light beam are directed onto a dedicated zone that is at least outside the visually useful zone of the retina of the wearer's eye.

[0012] In the method according to the present disclosure, the determination of the build tilt angle allows the diffractive light rays to be directed into a dedicated zone where the wearer's vision is not affected by these light rays and / or where these light rays do not interfere with the wearer.

[0013] In this regard, considering that not all of the retina itself is useful for clear vision, the dedicated zone is generally at least outside the retina of the wearer's eye.

[0014] In other words, the dedicated zone is particularly at least outside the zone of the retina that is useful for clear vision.

[0015] More particularly, the dedicated zone can be outside the pupil of the wearer's eye.

[0016] The dedicated zone can also be outside the wearer's eye itself.

[0017] The "redirected" diffractive light rays are the light rays generated in the ophthalmic device due to the stacking of the layers.

[0018] If these light rays that reach the retina or at least the region of the retina useful for clear vision, or reach the pupil of the eye, are not "redirected", they will come from a virtual region outside the contour line of the ophthalmic device.

[0019] These light rays can be referred to as interfering light rays.

[0020] In fact, layer-by-layer additive manufacturing of an ophthalmic device may introduce some optical defects in some directions, and these optical defects may cause visual distortion.

[0021] The optical defects discussed herein may occur between successive layers that are stacked on top of each other, and basically do not occur between adjacent individual volume elements or voxels.

[0022] The inventors have found that such optical defects may be due to refractive index inhomogeneities at the joints of the layers.

[0023] In other words, due to the repeated redistribution of such defects, a diffraction effect may occur, which may lead to multiple diffraction orders in the ophthalmic device.

[0024] Some of these diffraction orders may have low intensity and thus will not be perceived by the human eye or will only be barely perceptible to the human eye, while some of these diffraction orders may provide strong energy that will cause significant visual distortion.

[0025] Therefore, it is considered that building by layering may form a diffraction structure that produces optical defects.

[0026] Therefore, the aim of the method according to the present disclosure is to mitigate some of the optical defects inherently formed by the additive manufacturing of an ophthalmic device, in particular the visual distortion caused by the diffraction effect.

[0027] It should be noted that in the method according to the present disclosure, the optical defects are not deleted, but are completely or at least partially hidden from the wearer of the ophthalmic device.

[0028] In other words, the method according to the present disclosure allows the diffracted light beam to be directed so as not to affect the vision of the wearer of the ophthalmic device.

[0029] The present disclosure also provides a method for additive manufacturing an ophthalmic device to be worn by a wearer, the method comprising: additively manufacturing a plurality of layers of a predetermined material to obtain the ophthalmic device, and determining a build tilt angle of the ophthalmic device, determining the build tilt angle of the ophthalmic device includes the step of determining at least one threshold angle value, according to which, when the wearer wears the ophthalmic device, interfering diffracted light rays at least avoid the region of the retina of the wearer's eye that is useful for vision.

[0030] Such a threshold angle value can correspond to the transition between a configuration in which interfering diffracted light rays may reach a visually useful area of the retina and a configuration in which such light rays do not reach these areas of the retina.

[0031] In a variant, an angular value range can be determined.

[0032] Such an angular value range can be convenient because the transition between a configuration in which interfering diffracted light rays may reach a visually useful area of the retina and a configuration in which such light rays do not reach these areas of the retina can occur at different tilt angle values.

[0033] The determined construction tilt angle is higher than or lower than at least one threshold angle value and / or not within the angular value range, depending on whether the construction tilt angle is determined with respect to the direction of the optical axis or with respect to the surface of the ophthalmic device or a plane close to such a surface.

[0034] In any case, it is simpler to evaluate the construction tilt angle from a point located on the ophthalmic article than from a point on the wearer's eye.

[0035] Such a threshold angle value or range of values depends on some wearer parameters, such as parameters related to the wearer's eye itself and parameters related to the arrangement of the ophthalmic device on the wearer.

[0036] In particular, the threshold angle value or range of values can depend on characteristics such as the size and / or shape of the wearer's pupil and / or retina, and / or the final contour of the ophthalmic device, and / or the distance value between the pupil and the ophthalmic device when the wearer is wearing the ophthalmic device.

[0037] For example, it is possible to determine how light rays pass through the pupil towards a visually useful area of the retina based on the solid angle given for a predetermined position and width of the pupil, and a threshold angle value can be determined to avoid interfering light rays passing through the optical center of the pupil and / or penetrating into the pupil itself, or even optionally, to avoid interfering light rays being directed towards a visually useful area of the retina, and / or taking into account the pupil being enlarged, for example, for night vision.

[0038] All these parameters can be determined (i.e., provided or calculated) as raw values or average values.

[0039] Additionally, it can be considered that the threshold angle value can be defined between the stratification axis and the axis passing through both the center of the eye and the optical center of the ophthalmic device.

[0040] The method of the present disclosure may include: additively manufacturing a plurality of layers of a predetermined material to obtain an ophthalmic device having a contour line connecting a first face and a second face opposite the first face, and determining a build tilt angle such that diffracted light rays of a light beam that will reach the retina, as described above, will originate from a region located near or outside the contour line.

[0041] The ophthalmic device has a first face, a second face opposite the first face, and a contour line connecting the first face and the second face.

[0042] The contour line may be defined as the final contour of the ophthalmic device that the wearer intends to wear as such, or as an intermediate contour that is subsequently edged to form the final contour.

[0043] Based on the above, diffracted light rays (also referred to as interfering light rays) of a light beam that will reach the retina will originate from a peripheral region of the ophthalmic device that extends near the intermediate contour and is outside the main viewing area used by the wearer.

[0044] In other words, if the angles of diffracted light rays generated from the ophthalmic device are extrapolated to interfering light rays that will reach the region of the eye (or the eye itself) and that will interfere with the wearer, such light rays must be generated from a region outside the final contour that the wearer intends to wear as such.

[0045] Accordingly, since the interfering (diffracted) light rays must be generated from a region outside the final contour of the ophthalmic device by determining the build tilt angle (also referred to as the determined build orientation), such light rays are not formed in the manufactured ophthalmic device.

[0046] Advantageous and convenient features of the manufacturing method are described below.

[0047] Each layer is manufactured by projecting and polymerizing at least one image onto the surface of a volume of the predetermined material or by inkjet printing.

[0048] In the case of manufacturing by projecting and polymerizing at least one image onto the surface of a volume of the predetermined material, the method may include the step of varying the polymerization energy during curing.

[0049] The step of additively manufacturing a plurality of layers of the predetermined material is performed substantially vertically and in an inclined manner.

[0050] The substantially vertical and inclined build of the ophthalmic device means that the ophthalmic device is not built substantially horizontally from its first face to its second face.

[0051] Accordingly, the ophthalmic device to be manufactured includes an optical axis that passes through the optical center and is different from the layering axis.

[0052] The build tilt angle located here between the optical axis and the lamination axis is defined relative to the lamination axis based on which the layers are built or relative to the optical axis of the ophthalmic device to be manufactured.

[0053] The above also means that the ophthalmic device is built according to the orientation of the device, which is defined at least according to the average plane approximating the first and second faces, and this average plane is substantially vertical or inclined compared to the horizontal plane defined as being substantially perpendicular to the build direction or the lamination axis.

[0054] Of course, the above situation takes into account that the first and second faces are much larger than the thickness of the contour line.

[0055] The method includes the step of additively manufacturing a support on which the ophthalmic device can be built vertically and in an inclined manner, and the support includes a support surface, the tilt angle of which relative to the lamination axis varies with the build tilt angle.

[0056] The tilt angle of the support surface is similar to or different from the build tilt angle.

[0057] The method includes the step of determining the build tilt angle at least according to the following: geometric characteristics related to the optical function of the ophthalmic device to be manufactured; and / or geometric characteristics related to the final contour of the ophthalmic device to be manufactured; and / or geometric characteristics related to the thickness of the layers; and / or parameters of the predetermined material, such as refractive index and / or its composition.

[0058] As explained above, the difference between the intermediate contour and the final contour corresponds to the edging of the ophthalmic device, and the edging is to conform the contour line of the ophthalmic device to the spectacle frame in which the ophthalmic device is intended to be worn by the wearer and is to be installed.

[0059] In other words, the ophthalmic lens is additively manufactured with an intermediate contour and is intended to be processed later according to an edging step to achieve the final contour, which will enable the ophthalmic lens to be installed in the above spectacle frame.

[0060] Alternatively, the ophthalmic lens can be additively manufactured with an intermediate contour that is already in the final contour that will enable the ophthalmic lens to be installed in the above spectacle frame.

[0061] The method can further include the step of determining the angular orientation of the ophthalmic device to be manufactured defined around the optical axis passing through the optical center at least according to the following: geometric characteristics related to the optical function of the ophthalmic device to be manufactured; and / or geometric characteristics related to the final contour of the ophthalmic device to be manufactured; and / or geometric characteristics related to the thickness of the layers; and / or parameters of the predetermined material, such as refractive index and / or its composition.

[0062] For example, the angular orientation can be determined such that the ophthalmic device is constructed from bottom to top (when mounted in the frame of an eyewear lens, the bottom and top respectively corresponding to the bottom and top of the device), or vice versa, or from nose to temple, or vice versa, or from one part located therebetween to another part.

[0063] The method may further comprise the steps of: selecting at least one build tilt angle, and determining at least one virtual zone on the ophthalmic device to be manufactured, in which interfering diffracted rays of the beam are directed, the at least one virtual zone including regions of interest located near or outside the final contour of the ophthalmic device to be manufactured.

[0064] The regions of interest are preferably defined outside the wearer's field of view or vision.

[0065] In other words, the goal is to determine and select a direction in which the diffracted rays of the beam can be eliminated such that the wearer does not see them.

[0066] The method may further comprise the step of inferring from the regions of interest the angular orientation of the ophthalmic device to be manufactured, the angular orientation corresponding to the selected build tilt angle.

[0067] These steps must be understood as something like a "calibration sequence". A hypothetical build tilt angle is selected, the virtual zone is determined, and then the build tilt angle is confirmed or not confirmed based on the regions of interest.

[0068] Steps may also be performed to determine the threshold angle value or range of values as described above.

[0069] According to a second aspect, the present disclosure also provides a command and control unit comprising system elements configured to run a computer program in order to implement each of the steps of a method for additive manufacturing an ophthalmic device to be worn by a wearer, the method comprising: additive manufacturing a plurality of layers of a predetermined material in order to obtain the ophthalmic device, and determining a build tilt angle such that when the wearer wears the ophthalmic device, interfering diffracted rays of the beam are directed onto a dedicated zone located at least outside the visually useful zone of the retina of the wearer's eye.

[0070] According to a third aspect, the present disclosure further provides a manufacturing system comprising an additive manufacturing module and a command and control unit as described above, the system being configured to perform the steps of the additive manufacturing method as described above.

[0071] The manufacturing system further includes a curing device configured to project and polymerize at least one image on the surface of a predetermined volume of material, and is formed by a digital light processing unit, and / or a stereolithography unit including a laser source and a scanning head, and / or an inkjet printer.

[0072] According to a fourth aspect, the present disclosure also provides a computer program including instructions configured to, when the computer program is run by a computer, implement at least a part of a method for additive manufacturing of an ophthalmic device to be worn by a wearer, the method including: additive manufacturing a plurality of layers of a predetermined material to obtain the ophthalmic device, and determining a build tilt angle such that when the wearer wears the ophthalmic device, interfering diffracted light rays of a light beam are directed onto a dedicated area that is at least outside a visually useful area of the retina of the wearer's eye.

[0073] According to a fifth aspect, the present disclosure further provides a client-server communication interface for transmitting at least manufacturing data, such as the determined build tilt angle, to a remote computer, the manufacturing data being determined by a computer program that, when the computer program runs in a command and control unit, implements at least some steps of a method for additive manufacturing of an ophthalmic device to be worn by a wearer, the method including: additive manufacturing a plurality of layers of a predetermined material to obtain the ophthalmic device, and determining a build tilt angle such that when the wearer wears the ophthalmic device, interfering diffracted light rays of a light beam are directed onto a dedicated area that is at least outside a visually useful area of the retina of the wearer's eye, and the remote computer implements other steps of this additive manufacturing method. BRIEF DESCRIPTION OF THE DRAWINGS

[0074] The description of the present disclosure now continues with a detailed description of the embodiments given below by way of non-limiting examples and with reference to the drawings.

[0075] Figure 1 is a schematic view of a manufacturing system configured to perform a method for additive manufacturing of an ophthalmic device.

[0076] Figure 2 Graphically shows a client-server communication interface including system components configured to transmit at least one configuration parameter determined by a method according to the present disclosure to a remote data processing system.

[0077] Figure 3 is a block diagram showing steps of a method for additive manufacturing of an ophthalmic device according to the present disclosure.

[0078] Figure 4The ophthalmic device obtained by the method according to the present disclosure is shown in cross-section.

[0079] Figure 5 The relationship between the ophthalmic device obtained by the method according to the present disclosure and the wearer wearing the ophthalmic device is shown.

[0080] Figure 6 The ophthalmic device is shown in a front view.

[0081] Figure 7 It is a block diagram showing further steps of a method for additive manufacturing an ophthalmic device according to the present disclosure.

[0082] Figure 8 is Figure 6 A similar view, showing a virtual zone on an ophthalmic device having a first optical function in order to determine a build tilt angle.

[0083] Figure 9 is Figure 8 A similar view, for an ophthalmic device having a second optical function different from the first optical function. Detailed Description

[0084] Figure 1 Schematically shows a manufacturing system 1 configured to perform a method for additive manufacturing an ophthalmic device 2.

[0085] In the illustrated embodiment, the manufacturing system 1 includes a tank 10 filled with a volume of a predetermined material 11 suitable for manufacturing the ophthalmic device 2, such as a liquid resin for manufacturing glasses.

[0086] The manufacturing system 1 is an additive manufacturing system configured to manufacture the ophthalmic device 2 layer by layer, each layer 3 being formed by at least partial polymerization and hardening of a volume of the predetermined material 11.

[0087] In this regard, the manufacturing system 1 includes an additive manufacturing unit 12, also referred to as an additive manufacturing module, which is configured to project and polymerize at least one image on a surface 13 of a volume of the predetermined material 11 in the tank 10.

[0088] The additive manufacturing unit 12 may include a processing device 14 having, for example, a digital light processor configured to process a single image or pattern and / or multiple images or patterns.

[0089] The additive manufacturing unit 12 may further include a projection and polymerization device 15, which is configured to provide curing energy and has, for example, a projector and a radiation source, or an energy source, or other known sources for projecting a single image and / or multiple images successively in a single direction towards the material 11 for each layer 3 and then polymerizing and hardening the material 11.

[0090] In a variant, the digital light processor and the polymerization device are replaced by a laser source and a scanning device, which are configured to scan the surface 13 of the material 11 with the laser source.

[0091] In another variant (not shown), the additive manufacturing unit is an inkjet printer configured to project the material.

[0092] The additive manufacturing unit 12 may further include a command and control unit 27, which includes system elements configured to run a computer program including instructions configured to implement each of the steps of the additive manufacturing method for manufacturing the ophthalmic device 2 according to the present disclosure.

[0093] The additive manufacturing unit 12 is located on the upper side of the tank 10 and faces the upper opening 16 of the tank 10 opposite to the bottom 17 of the tank 10. This arrangement allows the execution of a so-called top-down process as explained below.

[0094] In another arrangement (not shown), the additive manufacturing unit may be located on the lower side of the tank and face a complementary opening formed on the bottom of the tank to allow, for example, a laser source to scan the surface of the material, here the bottom surface of the material within the tank. This another arrangement allows the execution of a so-called bottom-up process as also explained below.

[0095] The manufacturing system 1 further includes a build platform 20, a transparent plate 21, and a flexible separation membrane 22 that are at least partially immersed in the tank 10, and the flexible separation membrane Figure 1 is shown as being placed on and in contact with the transparent plate 21.

[0096] The flexible separation membrane 22 faces the build platform 20, and the transparent plate 21 faces the additive manufacturing unit 12.

[0097] The flexible separation membrane 22 is mechanically connected to the frame 30 of the manufacturing system 1 by an end 31.

[0098] The transparent plate can be made of glass or plastic, while the flexible separation membrane can be made of, for example, polytetrafluoroethylene (PTFE). In a variant, the flexible separation membrane can be made of, for example, Teflon AF (such as AF 2400 or AF 1600), or perfluoroelastomer (PFE), polypropylene (PP), polyethylene terephthalate (PET), perfluoroalkoxy (PFA), or also silicone rubber, etc.

[0099] Accordingly, the additive manufacturing unit 12 is configured to project at least one image or pattern through the transparent plate 21 and the flexible separation membrane 22 onto the surface 13 of a predetermined volume of material 11 in the tank 10 for forming each layer 3 of the ophthalmic device 2 on the build platform 20, such that each formed and at least partially hardened layer 3 is sandwiched between the build platform 20 and the flexible separation membrane 22.

[0100] In particular, the additive manufacturing unit 12 is capable of transferring a certain amount of energy suitable for triggering the polymerization of the predetermined material in the form of an image or pattern to the surface of a predetermined volume of the material.

[0101] The additive manufacturing unit 12 includes a controller configured to form a plurality of images and / or at least so-called grayscale images for sending a determined amount of energy, optionally a variable amount of energy.

[0102] The controller of the additive manufacturing unit 12 can also be configured to vary the energy during curing, also referred to as polymerization energy.

[0103] The manufacturing system 1 further includes a moving unit 25 configured to move at least one of the build platform 20, the transparent plate 21, and the frame 30 relative to one another.

[0104] The build platform 20, the transparent plate 21, and the flexible separation membrane 22 are each directly or indirectly mounted on a rigid body 26 and can also be movably mounted relative to the rigid body 26.

[0105] The moving unit 25 can act on the build platform 20, or on the transparent plate 21, or on the frame 30 that partially supports the flexible separation membrane 22, or on two of them. The moving unit 25 can act on the build platform 20, the transparent plate 21, and the flexible separation membrane 22 either correlatively or independently.

[0106] In particular, the moving unit 25 can be configured to:

[0107] - raise or lower the build platform 20 towards or away from the bottom 17 of the tank 10; and / or

[0108] - raise or lower the transparent plate 21 towards or away from the bottom 17 of the tank 10 and thus towards or away from the build platform 20; and / or

[0109] - Raise or lower the frame 36 mechanically connected to the flexible separation membrane 22 towards or away from the bottom 17 of the tank 10 so as to position at least a portion of the flexible separation membrane 22 relative to both the build platform 20 and the transparent plate 21.

[0110] In an alternative embodiment, the moving unit 25 may be configured to raise or lower the tank 10 relative to at least one of the build platform 20, the transparent plate 21, and the frame 30 mechanically connected to the flexible separation membrane 22.

[0111] In another alternative embodiment, the device does not have a membrane or a flexible separation membrane, but instead includes a recoater.

[0112] Figure 2 A client - server communication interface 24 is shown, including, for example, a so - called supplier side 29a and another so - called client side 29b, and the two sides communicate via an Internet interface 28.

[0113] The supplier side includes a server 29a that is linked to a data processing system or to a command and control unit 27a of the same type as Figure 1 and the server 29a is configured to communicate with the Internet interface 28.

[0114] The client side 29b is configured to communicate with the Internet interface 28 and is linked to a data processing system or to a command and control unit 27b of the same type as the supplier side.

[0115] In addition, the command and control unit 27b on the client side is linked to a manufacturing system 1b of the same type as Figure 1 for layer - by - layer 3b manufacturing of an ophthalmic device 2b.

[0116] For example, the command and control unit 27b on the client side is configured to receive from the user information about the ophthalmic device to be machined and some parameters regarding the manufacturing method intended to be implemented for additive manufacturing of the ophthalmic device 2b.

[0117] The command and control unit 27b on the client side uses the Internet 28 and the server 29a interface to send the received data to the command and control unit 27a on the supplier side for determination of manufacturing files and operating parameters.

[0118] The command and control unit 27a on the supplier side executes the computer program it contains in order to implement some steps of the method for additive manufacturing of an ophthalmic device.

[0119] Using the server 29a and the Internet interface 28, the command and control unit 27a on the supplier side sends the manufacturing files and operating parameters to the command and control unit 27b on the client side.

[0120] The command and control unit 27b on the client side is hereby configured to execute software for performing other steps of a method for additive manufacturing of an ophthalmic device.

[0121] In a variant, the manufacturing system can be located on the supplier side, such that the command and control unit on the supplier side is configured to determine a manufacturing file and operating parameters and to additively manufacture an ophthalmic device.

[0122] Figure 3 is a block diagram showing the main steps of a method for additive manufacturing of an ophthalmic device 2 performed by the manufacturing system 1 as described above.

[0123] The method includes successive steps 100 of additively manufacturing a plurality of layers 3 of a predetermined material 11 layer by layer.

[0124] The main steps of the method hereby include an iterative layering step 101 and a curing step 102 in order to form the ophthalmic device 2 layer by layer.

[0125] The layering step 101 is performed to position the components of the manufacturing system (including at least the build platform 20, the transparent plate 21, and the flexible separation membrane 22) at a build position, at which a predetermined material 11 of a predetermined thickness is provided only between the flexible separation membrane 22 and the build platform 20 or the layer already formed on the build platform. The predetermined thickness of the predetermined material 11 corresponds to the thickness of the layer to be formed upon curing.

[0126] During this layering step, the volume of the predetermined material can be the same for each layer.

[0127] The layering step 101 can include a step 110 of moving the build platform 20 to a predetermined position, and / or a step 120 of moving the frame 30 to which the flexible separation membrane 22 is mechanically fastened relative to the build platform 20, and / or a step 130 of moving the transparent plate 21 relative to the build platform 20 and / or relative to the frame 30 to which the flexible separation membrane 22 is mechanically fastened.

[0128] The curing step 102 includes the step of projecting and polymerizing at least one image on the surface 13 of a certain volume of the predetermined material 11 in the tank 10 through the transparent plate 21 and the flexible separation membrane 22 placed on and in contact with the transparent plate 21.

[0129] The curing step 102 includes, for example, projecting a single image in a single direction towards the material 11 by means of a projection device 14 or projecting a plurality of images that are successively projected simultaneously. Such a process is generally referred to as a DLP process.

[0130] In a variant, the step of projecting an image includes scanning the surface of the material by means of a laser source. Such a process is generally referred to as an SLA process.

[0131] Each layer 3 of the ophthalmic device 2 is formed or stacked on the build platform 20 or on the previous layer on the platform and is hardened at least in part by curing, where the layer 3 is sandwiched between the build platform 20 or the previous layer and the flexible separation membrane 22.

[0132] It should be noted that for at least one image, the method may include the step of changing the polymerization energy during curing, where the gradient is spatially related to the image or temporally related during the temporal exposure of the image.

[0133] Figures 4 to 6 The orientation of the ophthalmic device 2 during its construction is shown.

[0134] The ophthalmic device 2 has at least a first face 50 oriented downward, at least a second face 51 oriented upward opposite the first face 50, and a contour line 52 connecting the first face 50 and the second face 51.

[0135] Referring to the description of the system above, the first face 50 of the ophthalmic device 2 faces the additive manufacturing unit 12 here.

[0136] The ophthalmic device 2 is constructed vertically and in an inclined manner here.

[0137] As explained above, the substantially vertical and inclined construction of the ophthalmic device 2 means that the ophthalmic device is not constructed substantially horizontally from its first face 50 to its second face 51.

[0138] Layers 3 of a predetermined material are stacked along a substantially vertical layering axis SA, and the ophthalmic device 2 includes an optical axis OA that passes through the optical center OC of the ophthalmic device 2 and is different from the layering axis SA.

[0139] The optical axis OA is inclined relative to the layering axis SA but not perpendicular.

[0140] In other words, the layers 3 are constructed according to a build tilt angle that is here between the optical axis OA and the layering axis SA, which is defined relative to the layering axis SA on which the build layer 3 is based or relative to the optical axis OA of the ophthalmic device 2 to be manufactured.

[0141] The ophthalmic device 2 is configured to be worn by a wearer 60, who mainly uses the main viewing area 65 of the ophthalmic device 2 (see Figure 6 ). The main viewing area 65 is not a single vision but the area that the wearer most commonly uses in their field of view.

[0142] The main viewing area 65 extends around the optical center OC of the ophthalmic device 2.

[0143] However, the user can also look at the peripheral area 66 of the ophthalmic device 2 that extends between the main viewing area 65 and the contour line 52.

[0144] Figure 4 The contour line 52 therein represents the intermediate contour of the ophthalmic device 2, while Figure 5 and Figure 6 the contour line 52 therein represents the final contour of the ophthalmic device 2.

[0145] The difference between the intermediate contour and the final contour corresponds to the edging of the ophthalmic device 2, which is to conform the contour line 52 of the ophthalmic device to the spectacle frame in which the wearer is intended to wear and in which the ophthalmic device 2 is to be mounted.

[0146] In other words, for any ophthalmic device, the ophthalmic device 2 includes a central viewing area 65 that is expected to receive more than 75% of the wearer's viewing directions when the wearer uses the ophthalmic device 2 mounted in a spectacle frame, and a peripheral area 66 that is expected to receive less than 20% of the viewing directions.

[0147] Therefore, the build tilt angle is determined such that the diffracted light rays 70 of the light beam 70 that would interfere with the wearer's vision will originate from areas near or outside the contour line 52.

[0148] In other words, the build tilt angle is determined such that the interfering diffracted light rays 70 of the light beam 71 are directed onto a dedicated area outside the pupil 62 of the eye 61 of the wearer 60, and thus at least outside the area of the retina of the eye 61 that is useful for clear vision.

[0149] Based on the above, the interfering diffracted light rays 70 of the light beam 70 will originate from the peripheral area 66 of the ophthalmic device 2, which extends near the intermediate contour and outside the central viewing area 65 used by the wearer.

[0150] In other words, if the angles of the diffracted light rays generated from the ophthalmic device 2 are extrapolated to areas (or the eye itself) of the eye that would interfere with the wearer, the interfering diffracted light rays 70, then such rays must be generated from areas outside the final contour in which the wearer intends to wear it.

[0151] Accordingly, since the interfering diffracted light rays 70 must be generated from areas outside the final contour of the ophthalmic device 2 by determining the build tilt angle (also known as the determined build orientation), such rays are not formed in the manufactured ophthalmic device 2.

[0152] Figure 5 It is shown that by additive manufacturing the layer 3 according to the build tilt angle, when the manufactured ophthalmic device 2 is mounted in a frame, in both cases where the wearer 60 looks at the central viewing area 65 (shown by the lower eye in the drawing) and looks at the peripheral area 66 (shown by the upper eye in the drawing), the diffracted light rays 70 formed within the manufactured ophthalmic device do not point to the pupil 62 of the eye 61 of the wearer 60.

[0153] In addition, the lamination axis corresponding to the construction direction of the ophthalmic device 2 extends substantially vertically and along the diameter or profile of the lens rather than along the thickness of the lens.

[0154] Accordingly, the angular orientation position of the ophthalmic device 2 to be manufactured can be further determined and / or inferred, which is defined around the optical axis OA passing through the optical center OC.

[0155] For example, the angular orientation can be determined such that the ophthalmic device is constructed from the lower part to the upper part (when mounted in the frame of an eyeglass lens, the lower and upper parts correspond to the bottom and top of the device respectively) or vice versa, or is constructed from the nasal side to the temporal side or vice versa, or from one part located therebetween to another part.

[0156] It should be noted that the final profile of the ophthalmic device generally has the shape of a circle that is not centered on its optical center.

[0157] In addition, the ophthalmic device can generally include a dioptric power that includes a non-spherical order, such as for progressive multifocals or aspherization or astigmatism correction.

[0158] Therefore, the construction angle can depend on the angular orientation.

[0159] In fact, some angular orientations of the ophthalmic device can enable some interfering diffracted light rays to be located in a virtual area outside the final profile, and the construction angle of the virtual area is less than or greater than other angular orientations.

[0160] Thus, the angular orientation that is most suitable for its own process and the expected quality of the manufactured ophthalmic device can be selected, thereby providing further degrees of freedom for its construction strategy.

[0161] In Figure 6 the ophthalmic device 2 is considered to be in front of the wearer's eye, and a plurality of arrows 81 to 84 define a contour line 52, which corresponds to the final profile and can be equivalent to the wearer's visual field.

[0162] The final profile of the ophthalmic device 2 corresponds to the shape that matches the frame of the eyeglass lens.

[0163] The optical center OC coincides with the position of the center of rotation of the wearer's eye here.

[0164] Arrow 81 corresponds to the top direction starting from the optical center OC (which is also equivalent to the negative α angle), arrow 82 corresponds to the bottom direction starting from the optical center OC (which is also equivalent to the positive α angle), arrow 83 corresponds to the temporal direction starting from the optical center OC (which is also equivalent to the temporal β angle), and arrow 84 corresponds to the nasal direction starting from the optical center OC (which is also equivalent to the nasal β angle).

[0165] Arrow 85 here corresponds to the top-nasal direction defined between the optical center OC and the frame edge, which is also equivalent to the combination of the α angle and the β angle.

[0166] In other words, in addition to the build tilt angle, the build orientation of layer 3 of the ophthalmic device 2 can be selected, which is shown, for example, by arrow 85 starting from the optical center and pointing to the contour line 52.

[0167] Additionally, the method can include the step of additive manufacturing a support (not shown), on which the ophthalmic device 2 can be built vertically and in an inclined manner, and the support includes a support surface, and the tilt angle of the support surface relative to the layer axis can vary with the build tilt angle.

[0168] As Figure 7 shown, the method includes step 150 of determining the build tilt angle at least based on the following:

[0169] - Geometric characteristics related to the optical function of the ophthalmic device 2 to be manufactured; and / or

[0170] - Geometric characteristics related to the final contour line of the ophthalmic device 2 to be manufactured; and / or

[0171] - Geometric characteristics related to the thickness of layer 3; and / or

[0172] - Parameters of the predetermined material, such as markings and / or its composition.

[0173] It should be noted that the difference between the contour line and the final contour corresponds to the edging of the ophthalmic device 2, and the edging is to conform its contour line to the spectacle frame in which the wearer 60 wears and the ophthalmic device 2 is installed.

[0174] In a variant, the ophthalmic device 2 can be directly formed with a contour line corresponding to the final contour, thereby avoiding such edging.

[0175] It should be noted that the step of determining the build tilt angle can include the step of determining at least one threshold angle value or value range, according to which the interfering diffracted light avoids the pupil 62 of the eye 61 of the wearer 60, and then, the build tilt angle takes a value higher than or lower than at least one threshold angle value and / or outside the angle value range.

[0176] The method may further comprise a step 160 of determining an angular orientation of the ophthalmic device 2 to be manufactured, at least based on similar parameters as mentioned above, the angular orientation being defined about an optical axis OA passing through the optical center OC, and these similar parameters being:

[0177] - Geometric characteristics related to the optical function of the ophthalmic device 2 to be manufactured; and / or

[0178] - Geometric characteristics related to the final contour line of the ophthalmic device 2 to be manufactured; and / or

[0179] - Geometric characteristics related to the thickness of layer 3; and / or

[0180] - Parameters of a predetermined material, such as refractive index and / or its composition.

[0181] The method may further comprise a step 170 of selecting at least one build tilt angle and a step 180 of determining at least one virtual zone on the ophthalmic device 2 to be manufactured, wherein interfering diffracted rays of the light beam originate from the virtual zone.

[0182] The at least one virtual zone includes at least an area of interest located near or outside the final contour of the ophthalmic device 2 to be manufactured.

[0183] The area of interest is preferably defined outside the wearer's visual field or field of view.

[0184] In other words, the goal is to determine and select a direction in which interfering diffracted rays of the light beam can be eliminated so that the wearer cannot see them.

[0185] Then, the method may further comprise a step 190 of inferring the angular orientation of the ophthalmic device 2 to be manufactured from the area of interest, the angular orientation corresponding to the selected build tilt angle.

[0186] Of course, when no virtual zone meets the requirements (i.e., no build tilt angle can be selected), further determination is made starting from another (hypothetical) build tilt angle.

[0187] Figure 8 and Figure 9 shows Figure 7 some of the steps disclosed in

[0188] Figure 8 shows an example of the ophthalmic device 2 to be manufactured, which is a plano lens (i.e., the optical function is zero).

[0189] Multiple shapes (here represented as circles C1, C2, and C3) represent virtual zones on the ophthalmic device 2 to be manufactured, which correspond to positions where diffracted rays of the light beam will be emitted in the direction of the wearer's retina, and the surface of the ophthalmic device 2 generally corresponds to the wearer 2's field of view.

[0190] In particular, the construction tilt angle corresponding to the circle C1 is equal to 0°. It can be seen that in this case, it is impossible to extend the diffracted rays 70 of the light beam 71 from a region located near or outside the contour line. Therefore, when the wearer wears the ophthalmic device, it is impossible to direct the rays 70 of the light beam 71 onto a dedicated area located outside the pupil 62 of the eye 61 of the wearer 60.

[0191] In contrast, the construction tilt angle corresponding to the circle C2 is different and is approximately 10° here. It can be seen that a part of the circle C2 is located outside the final contour, thus defining an area of interest as the source of diffracted light that is harmful to acuity.

[0192] In addition to the construction tilt angle, it is also possible to infer the angular (construction) orientation of the ophthalmic device 2 to be manufactured so that the diffracted rays 70 of the light beam 71 extend from a region located outside the contour line. Therefore, when the wearer wears the ophthalmic device, the rays 70 of the light beam 71 are directed onto a dedicated area located outside the pupil 62 of the eye 61 of the wearer 60.

[0193] Furthermore, the construction tilt angle corresponding to the circle C3 is larger and is approximately 15° here. It can be seen that most of the circle C3 is located outside the contour line 52, thus defining a large area of interest. From this area of interest, a wide range of angular (construction) orientations of the ophthalmic device 2 to be manufactured can be inferred so that the diffracted rays 70 of the light beam 71 extend from a region located outside the contour line. Therefore, when the wearer wears the ophthalmic device, the rays 70 of the light beam 71 are directed onto a dedicated area located outside the pupil 62 of the eye 61 of the wearer 60, thereby not impairing the acuity of the visual field.

[0194] Figure 9 Another example of the ophthalmic device 2 to be manufactured is shown. Here, the ophthalmic device is a progressive multifocal lens (also known as a PAL), that is, the optical function is complex, for example, having a zero power for distance vision and a positive addition for near vision.

[0195] The plurality of shapes C4 and C5 represent virtual areas on the ophthalmic device 2 to be manufactured, which correspond to the positions where the diffracted rays of the light beam will be emitted in the direction of the wearer's retina, while the surface of the ophthalmic device 2 generally corresponds to the visual field of the wearer 2.

[0196] In particular, the construction tilt angle corresponding to the shape C4 is equal to 0°. It can be seen that in this case, it is impossible to extend the diffracted rays 70 of the light beam 71 from a region located near or outside the contour line. Therefore, when the wearer wears the ophthalmic device, it is impossible to direct the rays 70 of the light beam 71 onto a dedicated area located outside the pupil 62 of the eye 61 of the wearer 60.

[0197] In contrast, the build tilt angle corresponding to shape C5 is different and is herein equal to approximately 10°. It can be seen that a part of shape C5 lies outside the contour line 52, thus defining an area of interest from which the angular orientation of the ophthalmic device 2 to be manufactured can be inferred so that the diffracted rays 70 of the light beam 71 extend from the area outside the contour line, and thus when the wearer wears the ophthalmic device, the rays 70 of the light beam 71 are directed onto a dedicated area outside the retina 62 of the wearer's 60 eye 61, thereby not impairing the acuity of the visual field.

[0198] In the method according to the above disclosure, the determination of the build tilt angle allows the interference diffracted rays generated in the ophthalmic device due to the stacking of layers to be directed into a dedicated area where the wearer's vision is not affected by these rays and / or where these rays do not interfere with the wearer.

[0199] In this regard, considering that not all of the retina itself is useful for clear vision, the dedicated area is generally at least outside the retina of the wearer's eye.

[0200] In other words, the dedicated area is in particular at least outside the area of the retina that is useful for clear vision.

[0201] More particularly, the dedicated area can be outside the pupil of the wearer's eye.

[0202] The dedicated area can also be outside the wearer's eye itself.

[0203] The "redirected" interference diffracted rays are the rays generated in the ophthalmic device due to the stacking of layers.

[0204] These interference rays that would reach the retina or at least the area of the retina that is useful for clear vision, or reach the pupil of the eye, if not "redirected", would come from a virtual area outside the contour line of the ophthalmic device.

[0205] In fact, additive manufacturing of the ophthalmic device layer by layer may introduce some optical defects in some directions, and these optical defects may cause visual distortion.

[0206] The optical defects discussed herein may occur between successive layers that are stacked on top of each other, and substantially not between adjacent individual volume elements or voxels.

[0207] The inventors have found that such optical defects may be due to the repeated refractive index inhomogeneities at the joints of the layers.

[0208] In other words, diffraction effects may thus occur, which may lead to multiple diffraction orders in the ophthalmic device.

[0209] Some of these diffraction orders may have low intensity and thus will not be perceived by the human eye or will only be barely perceptible, while some of these diffraction orders may provide strong energy that will produce significant visual distortion.

[0210] Therefore, it is considered that building by layering may form diffraction structures that produce optical defects.

[0211] Therefore, the aim of the method according to the present disclosure is to mitigate some of the optical defects inherently formed by the additive manufacturing of ophthalmic devices, in particular the visual distortion produced by diffraction effects.

[0212] It should be noted that in the method according to the present disclosure, the optical defects are not eliminated, but are completely or at least partially hidden from the wearer of the ophthalmic device.

[0213] In other words, the method according to the present disclosure allows the interfering diffracted light beams to be directed such that they do not affect the vision of the wearer of the ophthalmic device.

[0214] The interfering diffracted rays of the light beam will come from the peripheral region of the ophthalmic device, which extends near the middle contour and is outside the main viewing area used by the wearer.

[0215] In other words, if the interfering diffracted rays that would reach the region of the eye (or the eye itself) by extrapolating the angles of the diffracted rays generated by the ophthalmic device are such as to interfere with the wearer, then such rays must be generated from a region outside the final contour in which the wearer intends to wear it.

[0216] Accordingly, since the interfering diffracted rays must be generated from a region outside the final contour of the ophthalmic device by determining the build tilt angle (also known as the determined build orientation), such rays are not formed in the manufactured ophthalmic device.

[0217] It should be noted that the ophthalmic device can be an ophthalmic lens for an eyeglass lens or other device adapted to the wearer and having ophthalmic properties.

[0218] It should also be noted that the additive manufacturing method can be carried out according to any existing suitable technique, such as the techniques included in the definition given in the reference ISO / ASTM 52900:2021 or corresponding references.

[0219] More generally, it should be noted that the present disclosure is not limited to the examples described and presented.

Claims

1. A method for additive manufacturing an ophthalmic device (2, 2b) to be worn by a wearer (60), the method comprising: Additively manufacturing a plurality of layers (3, 3b) of a predetermined material (11) so as to obtain the ophthalmic device, and determining (150) a build tilt angle such that when the wearer wears the ophthalmic device (2, 2b), interfering diffracted rays (70) of a light beam (71) are directed onto a dedicated zone which is at least outside the visually useful zone of the retina of the wearer's eye (61).

2. The method according to claim 1, wherein, Determining (150) the build tilt angle includes determining at least one threshold angle value according to which the interfering diffracted rays avoid the visually useful zone of the retina of the wearer's eye (61).

3. The method according to claim 2, wherein, The build tilt angle takes a value higher or lower than the at least one threshold angle value.

4. The method according to any one of claims 1 to 3, wherein, The dedicated zone is located outside the wearer's eye (61).

5. The method according to any one of claims 1 to 4, comprising: Additively manufacturing a plurality of layers (3, 3b) of the predetermined material (11) so as to obtain the ophthalmic device (2, 2b) having a contour line (52) connecting a first face (50) and a second face (51) opposite the first face, and determining (150) the build tilt angle such that diffracted rays (70) of the light beam (71) reaching the retina will originate from a region located near or outside the contour line (52).

6. The method according to claim 5, wherein The region is located outside the final contour of the ophthalmic device (2, 2b) as the wearer intends to wear it.

7. The method according to any one of claims 1 to 6, wherein, Additively manufacturing the plurality of layers (3, 3b) of the predetermined material (11) is carried out substantially vertically and in an inclined manner along a layering axis (SA) such that the ophthalmic device (2, 2b) to be manufactured includes an optical axis (OA) passing through the optical center (OC) and different from the layering axis.

8. The method according to claim 7, wherein The build tilt angle is here located between the optical axis (OA) and the layering axis (SA) and is defined with respect to the layering axis on which the layer (3, 3b) is built or with respect to the optical axis of the ophthalmic device (2, 2b) to be manufactured.

9. The method according to any one of claims 1 to 8, including determining (150) the build tilt angle at least according to: geometric characteristics related to the optical function of the ophthalmic device (2, 2b) to be manufactured; and / or geometric characteristics related to the final contour of the ophthalmic device to be manufactured; and / or geometric characteristics related to the thickness of the layer (3, 3b); and / or parameters of the predetermined material (11), such as the refractive index and / or the composition of the predetermined material.

10. The method according to any one of claims 1 to 9, including determining (160) the angular orientation of the ophthalmic device (2, 2b) to be manufactured defined about an optical axis (OA) passing through the optical center (OC) of the ophthalmic device at least according to: geometric characteristics related to the optical function of the ophthalmic device to be manufactured; and / or geometric characteristics related to the final contour of the ophthalmic device (2, 2b) to be manufactured; and / or geometric characteristics related to the thickness of the layer (3, 3b); and / or parameters of the predetermined material (11), such as the refractive index and / or the composition of the predetermined material.

11. The method according to any one of claims 1 to 10, comprising selecting (170) at least one build tilt angle and determining (180) at least one virtual zone on the ophthalmic device (2, 2b) to be manufactured, the diffracted rays (70) of the light beam (71) being directed in the at least one virtual zone, the at least one virtual zone including an area of interest located near or outside the final contour of the ophthalmic device (2, 2b) to be manufactured.

12. The method according to claim 11, comprising inferring (190) the angular orientation of the ophthalmic device (2, 2b) to be manufactured from the area of interest, the angular orientation corresponding to the selected build tilt angle.

13. A manufacturing system, the manufacturing system comprising an additive manufacturing module and a command and control unit (27, 27a, 27b), the command and control unit including system elements configured to run a computer program to implement a method for additive manufacturing an ophthalmic device (2, 2b) to be worn by a wearer (60), the method comprising: Additively manufacturing a plurality of layers (3, 3b) of a predetermined material (11) so as to obtain the ophthalmic device, and determining (150) a build tilt angle such that when the wearer wears the ophthalmic device (2, 2b), the interfering diffracted rays (70) of the light beam (71) are directed onto a dedicated zone located at least outside the visually useful zone of the retina of the wearer's eye (61).

14. A computer program comprising instructions configured to at least partially implement a method for additive manufacturing of an ophthalmic device (2, 2b) to be worn by a wearer (60) when the computer program is run by a computer, the method comprising: Additively manufacturing a plurality of layers (3, 3b) of a predetermined material (11) so as to obtain the ophthalmic device, and determining (150) a build tilt angle such that when the wearer wears the ophthalmic device (2, 2b), the interfering diffracted rays (70) of the light beam (71) are directed onto a dedicated zone located at least outside the visually useful zone of the retina of the wearer's eye (61).

15. A client-server communication interface for transmitting at least manufacturing data, such as a determined build tilt angle, to a remote computer, the manufacturing data being determined by a computer program which, when run in a command and control unit (27a, 27b), implements at least part of a method for additive manufacturing of an ophthalmic device (2, 2b) to be worn by a wearer (60), the method comprising: Additively manufacturing a plurality of layers (3, 3b) of a predetermined material (11) so as to obtain the ophthalmic device, and determining (150) a build tilt angle such that when the wearer wears the ophthalmic device (2, 2b), the interfering diffracted rays (70) of the light beam (71) are directed onto a dedicated zone located at least outside the visually useful zone of the retina of the wearer's eye (61), the remote computer implementing the other steps of this additive manufacturing method.

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