Method for additively manufacturing an ophthalmic device and manufacturing system configured to perform such method

Abstract

The present disclosure provides a method for additively manufacturing an ophthalmic device (2), comprising additively manufacturing multiple layers (3) of a predetermined material to obtain an ophthalmic device, each layer being produced by projecting and polymerizing at least one image onto the surface of a volume of the predetermined material, with a first surface (50) facing downward and a second surface (55) facing upward, and for at least two consecutive layers, the method comprises forming at least one image that allows hardening a predetermined thickness of material on the side of the second surface facing upward and another thickness of material on the side of the first surface facing downward.

Description

[Technical Field]

[0001] The present disclosure relates to methods for additively manufacturing ophthalmic devices and manufacturing systems configured to perform such methods. [Background technology]

[0002] Known methods for additively manufacturing ophthalmic lenses include curing and layer-forming steps that are performed sequentially in a manufacturing system that includes a curing device, a layer-forming device, and a build platform positioned relative to a vat filled with a predetermined material, where the top of the manufacturing system corresponds to the location of the curing device, while the bottom of the manufacturing system corresponds to the opposite side of the build platform.

[0003] For example, each ophthalmic lens is built layer by layer on a build platform that is movable relative to a vat containing a volume of a predetermined material, the build platform is positioned at a predetermined location, a curing device including an irradiation source performs a curing step of a first layer of material, and a layer forming device performs a layer forming step by displacing at least the build platform to cure a new layer of material having a predetermined thickness.

[0004] In other words, in such known methods, a curing step is performed on a liquid layer for, for example, a plurality of ophthalmic lenses to be manufactured on a build platform, such that the liquid layer is cured, and then a layer formation step is performed to form a new liquid layer on the previous cured layer for the plurality of ophthalmic lenses to be manufactured.

[0005] Patent document 1 discloses a method for additive manufacturing of an optical article, which includes the steps of providing a starting optical system and additively manufacturing a complementary optical element layer by layer on the starting optical element, which may be in an inclined position.

[0006] Patent document 2 discloses a method for layer-by-layer additive manufacturing of optical articles, comprising additively manufacturing an intermediate optical element such that the intermediate optical element is tilted with respect to a predetermined additive build axis, called the stacking axis, along which a plurality of predetermined volume elements of at least one material are deposited in order to allow a polishing step in specific zones.

[0007] Patent Document 3 discloses a method for layer-by-layer additive manufacturing of optical articles using a micromirror device, such as a DMD (digital micromirror device), to generate a light beam of a desired shape from a photocurable resin for irradiating the photocurable resin. The micromirror device has multiple micromirrors arranged in a two-dimensional repeating structure. In a process using a DMD to photocuring the resin, the intensity of the projected light in the projected area of ​​the photocurable resin corresponding to the area of ​​the micromirror itself is different from the intensity of the projected light in the area corresponding to the area between adjacent micromirrors. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] International Publication No. 2015004383 Brochure [Patent Document 2] International Publication No. 2015086981 Brochure [Patent Document 3] International Publication No. 2018235209 Brochure Summary of the Invention [Problem to be solved by the invention]

[0009] The present disclosure relates to a method for additive manufacturing of ophthalmic devices that is easy to perform. [Means for solving the problem]

[0010] Thus, the present disclosure provides a method for additively manufacturing an ophthalmic device having a first surface, a second surface opposite the first surface, and a contour joining the first surface and the second surface, the method comprising the steps of additively manufacturing multiple layers of a predetermined material to obtain the ophthalmic device, each layer being manufactured by projecting and polymerizing at least one image onto the surface of a volume of the predetermined material, the first surface facing downward and the second surface facing upward, and for at least two consecutive layers, the method comprising the steps of forming at least one image that enables hardening of a predetermined thickness of material on the side of the second surface facing upward and another thickness of material on the side of the first surface facing downward.

[0011] The method according to the present disclosure allows additive manufacturing of ophthalmic devices having a first resolution on an upward-facing second surface and a second resolution on a downward-facing first surface, the second resolution being higher than the first resolution.

[0012] A downward facing first surface means that the first surface is oriented toward the bottom of the manufacturing system and can therefore be referred to as a down skin, and an upward facing second surface means that the second surface is oriented toward the top of the manufacturing system and can therefore be referred to as an up skin.

[0013] In certain embodiments, the method is performed without changing the orientation of the ophthalmic device during additive manufacturing and therefore without changing the resolution during the method.

[0014] Indeed, the method according to the present disclosure ensures that the material does not receive the same amount of energy in the upskin portion as in the downskin portion, and the method provides sufficient energy to the material that is at or will be located at the junction of two successive layers on the upwardly facing second surface.

[0015] By the method according to the present disclosure, at least a portion of the sublayer of material is formed on the downwardly facing first surface substantially at the junction of two successive layers on this side.

[0016] In other words, the method according to the present disclosure allows for the creation of sublayers having a thickness less than the thickness of the layer being built upon.

[0017] The printing step or staircase formed on the down skin side is smaller than the interlayer thickness of the entire material.

[0018] Ophthalmic devices can be constructed both vertically and at an angle.

[0019] Because it is built up essentially vertically, the resolution is in the stack axis, not the so-called "in-plane" resolution, which depends on the resolution of the curing method. In addition, higher resolution means smaller printing steps.

[0020] In one embodiment, the method includes a layer formation step of adding a volume of a predetermined material, followed by steps of projecting and polymerizing at least one image onto a surface of the added volume of the predetermined material.

[0021] During the layering step, the volume of a given material is the same for each layer.

[0022] The step of additively manufacturing multiple layers of a predetermined material occurs along a vertical stacking axis, and the ophthalmic device is constructed in a substantially vertical direction and includes an optical axis separate from the stacking axis.

[0023] The stacking axis is perpendicular to the fabrication plane.

[0024] The optical axis can be tilted in the range of about +10° to about +55° with respect to the fabrication plane.

[0025] Vertical build means that the ophthalmic device is built along the diameter or profile of the ophthalmic device, rather than along the thickness of the device, i.e., from one side to the other of the first and second sides.

[0026] The method includes additively manufacturing a support onto which ophthalmic devices are built vertically and inclined.

[0027] The support may be formed simultaneously with the ophthalmic device or may be preformed.

[0028] The support may include a support surface having a predetermined inclination relative to the stacking axis.

[0029] The method includes forming at least one image adapted to harden a predetermined thickness of material on the upward-facing second surface and another thickness of material on the downward-facing first surface, and slicing the one or more images.

[0030] The method includes forming at least one image adapted to harden a predetermined thickness of material on the upward-facing second surface and another thickness of material on the downward-facing first surface, and deforming the sliced ​​image or images.

[0031] The multiple sliced ​​images are projected sequentially.

[0032] A so-called greyscale image is projected.

[0033] The method may include varying the polymerization energy during curing.

[0034] The present disclosure further provides a manufacturing system configured to perform a method for additively manufacturing an ophthalmic device having a first surface, a second surface opposite the first surface, and a contour joining the first surface and the second surface, and additively manufacturing multiple layers of a predetermined material to obtain the ophthalmic device, wherein each layer is manufactured by projecting and polymerizing at least one image onto a surface of a volume of the predetermined material, the first surface facing downward and the second surface facing upward, and the manufacturing system includes a projection and polymerization apparatus configured to form at least one image that enables hardening of a predetermined thickness of material on the upward-facing second surface side and another thickness of material on the downward-facing first surface side for at least two successive layers.

[0035] The manufacturing system further includes a layer forming device configured to apply a volume of a predetermined material, after which a projection and polymerization device projects and polymerizes at least one image onto a surface of the applied volume of the predetermined material.

[0036] The projection and polymerization device is formed by a digital light processing unit and / or a stereolithography unit, which includes a laser source and a scanning head.

[0037] The system includes a controller configured to generate a plurality of sliced ​​images and / or at least a so-called grayscale image and / or to vary the polymerization energy during curing.

[0038] The description of the present disclosure now continues with a detailed description of the embodiments shown below, by way of non-limiting example and with reference to the accompanying drawings. [Brief explanation of the drawings]

[0039] [Figure 1] FIG. 1 is a schematic diagram of a manufacturing system configured to perform a method for additively manufacturing an ophthalmic device. [Figure 2] FIG. 1 is a block diagram illustrating steps in a method for additively manufacturing an ophthalmic device according to the present disclosure. [Figure 3]1 illustrates an ophthalmic device. [Figure 4] 1A-1D are diagrams illustrating schematically some steps of an additive manufacturing method according to a first embodiment. [Figure 5] 5A to 5C are diagrams illustrating schematically some steps of an additive manufacturing method according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0040] FIG. 1 illustrates schematically a manufacturing system 1 configured to perform a method for additively manufacturing an ophthalmic device 2 .

[0041] The manufacturing system 1 includes a tank 10 filled with a volume of a predetermined material 11 suitable for manufacturing ophthalmic devices 2, such as a liquid resin for manufacturing eyeglasses.

[0042] The manufacturing system 1 is an additive system configured to manufacture the ophthalmic device 2 layer by layer, with each layer 3 being formed by a volume of a predetermined material 11 that is at least partially polymerized and cured.

[0043] In this regard, the manufacturing system 1 includes a unit 12, also called an additive unit, configured to project and polymerize at least one image onto a surface 13 of a volume of a given material 11 in a tank 10.

[0044] The add-on unit 12 may include a processing unit 14 having, for example, a digital lighting processor configured to process a single image or pattern and / or multiple images or patterns.

[0045] The additive unit 12 may further include a projection and polymerization device 15 configured to provide curing energy, for example having a projector and a radiation or energy source or other known source for projecting a single image in a single direction towards the material 11 for each layer 3, and / or multiple images projected simultaneously or sequentially, and then polymerizing and curing the material 11.

[0046] In a variant, the digital illumination processor and polymerization device are replaced by a laser source and a scanning device configured to scan the laser source across the surface 13 of the material 11 .

[0047] 1, the add-on unit 12 is placed on the top surface of the tank 10, facing an upper opening 16 of the tank 10 opposite a bottom 17 of the tank 10. This configuration allows a so-called top-down process to be carried out, as will be explained below.

[0048] In another arrangement, the add-on unit can be located below the tank, facing an additional opening formed in the bottom of the tank, which allows a so-called bottom-up process to be carried out, as will be explained below.

[0049] The manufacturing system 1 further includes a build platform 20 at least partially submerged within the tank 10, a transparent plate 21, and a flexible separation membrane 22, shown in FIG. 1, positioned on and in contact with the transparent plate 21.

[0050] The flexible separation membrane 22 faces the build platform 20 , and the transparent plate 21 faces the add-on unit 12 .

[0051] The flexible separator membrane 22 is mechanically connected by ends 31 to a frame 30 of the manufacturing system 1 .

[0052] The transparent plate can be made of glass or plastic, and the flexible separator can be made of, for example, polytetrafluoroethylene (PTFE). In a variant, the flexible separator can also be made of Teflon AF, for example AF 2400 or AF 1600, or perfluoroelastomer (PFE), polypropylene (PP), polyethylene terephthalate (PET), perfluoroalkoxy (PFA), or silicone, etc.

[0053] Therefore, the additive unit 12 is configured to project at least one image or pattern onto the surface 13 of the volume of a predetermined material 11 in the tank 10 to form each layer 3 of the ophthalmic device 2 on the build platform 20 through a transparent plate 21 and a flexible separating membrane 22, so that each formed and at least partially hardened layer 3 is sandwiched between the build platform 20 and the flexible separating membrane 22.

[0054] In particular, the additive unit 12 can deliver an amount of energy to the surface of a volume of a predetermined material in an image or pattern suitable to cause polymerization of the predetermined material.

[0055] The add-on unit 12 includes a controller configured to generate a plurality of slice images and / or at least a so-called greyscale image.

[0056] The controller of the additive unit 12 may also be configured to vary the energy during curing, also referred to as polymerization energy.

[0057] The manufacturing system 1 further includes a movement unit 25 configured to move at least one of the build platform 20, the transparent plate 21, and the frame 30 relative to the others.

[0058] The build platform 20 , the transparent plate 21 , and the flexible separation membrane 22 are each mounted directly or indirectly on a rigid body 26 and may also be mounted movably relative to the rigid body 26 .

[0059] The movement unit 25 may act on the build platform 20, or on the frame 30 that partially supports the transparent plate 21, or the flexible separation membrane 22, or both. The movement unit 25 may act on the build platform 20, the transparent plate 21, and the flexible separation membrane 22 independently or independently.

[0060] In particular, the mobile unit 25 - Raising or lowering the build platform 20 towards or away from the bottom 17 of the tank 10; and / or - Raising or lowering 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 - positioning at least a portion of the flexible separation membrane 22 in a position relative to both the build platform 20 and the transparent plate 21 by raising or lowering the frame 36 to which the flexible separation membrane 22 is mechanically connected, toward or away from the bottom 17 of the tank 10; It can be configured as follows.

[0061] In an alternative embodiment, the movement 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 to which the flexible separation membrane 22 is mechanically connected.

[0062] In other alternative embodiments, the apparatus does not have a membrane, but rather includes a recoater.

[0063] FIG. 2 is a block diagram illustrating the main steps of a method for additive manufacturing of an ophthalmic device 2 carried out by a manufacturing system 1 as described above.

[0064] The method comprises successive steps 100 of additively manufacturing a plurality of layers 3 of a given material 11 layer by layer.

[0065] The main steps of the method include repeatedly repeating a layer forming step 101 and a curing step 102 to form the ophthalmic device 2 layer by layer.

[0066] A layer formation 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, in a build position where only a predetermined thickness of the predetermined material 11 is provided between the flexible separation membrane 22 and the build platform 20 or a layer already formed thereon. The predetermined thickness of the predetermined material 11 corresponds to the thickness of the layer to be formed when cured.

[0067] During the layer-forming step, the volume of the predetermined material may be the same for each layer or for at least two successive layers. In a variant, the volume of the predetermined material may vary.

[0068] The layer formation step 101 may include a step 110 of moving the build platform 20 in a predetermined position, and / or a step 120 of moving the frame 30 to which the flexible separation membrane 22 is mechanically fixed 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 fixed.

[0069] The curing step 102 includes projecting and polymerizing at least one image onto the surface 13 of the volume of predetermined material 11 in the tank 10 through the transparent plate 21 and the flexible separating membrane 22 placed on and in contact with the transparent plate 21.

[0070] The curing step 102 may involve the projection of a single image or multiple images projected simultaneously or sequentially in a single direction towards the material 11, for example by a projection device 14. Such a process is commonly referred to as a DLP process.

[0071] In a variant, the step of projecting the image comprises scanning the surface of the material with a laser source, such a process being commonly referred to as an SLA process.

[0072] Each layer 3 of the ophthalmic device 2 is formed or layered on the build platform 20 or on a previous layer on this platform at a position where the layer 3 is sandwiched between the build platform 20 or previous layer and the flexible separation membrane 22, and is at least partially hardened by curing.

[0073] 3 shows the orientation of the ophthalmic device 2 during its construction. The ophthalmic device 2 is constructed both vertically and at an angle.

[0074] The manufactured ophthalmic device 2 has a first surface 50 facing downward and called the down skin, a second surface 55 facing upward and opposite the first surface 50 and called the up skin, and an outer shape joining the first surface 50 and the second surface 55.

[0075] According to the present disclosure, and as shown in Figures 4 and 5, at least one image capable of hardening a predetermined thickness of material on the upward-facing second surface 55 and another thickness of material on the downward-facing first surface 50 for at least two consecutive layers, so that at least a portion of a sub-layer 60 of material is added to the junction of the two consecutive layers 3 on the upward-facing second surface 50.

[0076] It should be noted that the other thickness is a thickness that is different from the predetermined thickness and may be greater or less than the predetermined thickness, an additional thickness, or more generally a further thickness.

[0077] The additive manufacturing of multiple layers of a given material is performed along a stacking axis S, which is vertical here, and the ophthalmic device 2 can be constructed substantially vertically and includes an optical axis (not shown) separate from the stacking axis S.

[0078] The stacking axis S is perpendicular to the manufacturing plane P.

[0079] Therefore, the optical axis can be tilted with respect to the manufacturing plane P in the range of about +10° to about +55°.

[0080] Vertical build means that the ophthalmic device 2 is not built in the thickness direction, i.e., from one side of the first surface 50 and the second surface 55 to the other, but rather along the diameter or profile of the ophthalmic device 2.

[0081] The support (not shown) on which the ophthalmic device is constructed vertically and inclined can be additively manufactured, for example, simultaneously with the ophthalmic device 2 or beforehand.

[0082] The support may include a support surface having a predetermined inclination relative to the stacking axis.

[0083] The addition of sublayers 60 can be done according to different strategies.

[0084] The method may include forming at least one image that enables hardening of a predetermined thickness of material on the upward-facing second surface and another thickness of material on the downward-facing first surface, and slicing the one or more images.

[0085] In a variant, the method may include the steps of forming at least one image that allows hardening a predetermined thickness of material on the upward-facing second surface and another thickness of material on the downward-facing first surface, and deforming one or more slice images.

[0086] Multiple sliced ​​images can be projected sequentially, or so-called grayscale images can be projected (see more below).

[0087] Additionally, the method may include varying the polymerization energy during curing, such as disclosed in WO2018235209A1.

[0088] For example, in Figure 4, sublayer 60 is included in the current layer 3. At some point in the projected image, the curing energy is adapted so that the curing thickness is less than the layer thickness. Visually speaking, the image has "white areas" and the sublayer appears "gray." Sublayer 60 is created to overlap layer 3 below.

[0089] For example, in Figure 5, sublayer 60 is included in previous layer 3, i.e., the layer created in the previous step. At some point in the projected image, the curing energy is adapted so that the cured material corresponds to a thickness greater than the sum of the other thicknesses and the layer thickness, also called over-curing. Visually, the image appears gray, while the sublayer appears white, e.g., due to excess light.

[0090] Gray scale refers to projecting an image with possibly different levels of light intensity for each pixel of the device.

[0091] A grey scale with two levels can be used, for example 256 / 256 white and 128 / 256 grey.

[0092] To create the images, one possibility is to define a first image (first dedicated pixel at 256) by slicing at a regular slice height and a second image (second dedicated pixel at 128) by slicing at an intermediate slice height, and then combine both images.

[0093] Another way to create sublayers is to use different projectors to project different images with different amounts of light, either sequentially or simultaneously, to reach different curing thicknesses. To create an image, the subslicing can be done like a grayscale image.

[0094] In some embodiments, to manufacture an ophthalmic lens in a vertical orientation, the lens is tilted so that one side is entirely within the up skin and the opposite side is entirely within the down skin.

[0095] The resolution can be chosen depending on the complexity of the part or the level of detail to be created. In the case of ophthalmic lenses, complex designs such as progressive lenses require high resolution. Simpler designs such as single vision lenses are less critical and require lower resolution. In some cases, progressive lenses consist of a rather simple front (convex) surface and a complex back surface that includes the customization of the lens. Therefore, the resolution needs are not the same between the front and back surfaces. The method according to the present disclosure can be used to do that.

[0096] Thus, the method according to the present disclosure allows additive manufacturing of ophthalmic devices having a first resolution on the upward-facing second surface and a second resolution on the downward-facing first surface, the second resolution being higher than the first resolution.

[0097] Due to the essentially vertical build, the resolution is in the stack axis, not the so-called "in-plane" resolution. Additionally, higher resolution means smaller print steps.

[0098] This method is performed without changing the orientation of the ophthalmic device during additive manufacturing and therefore without changing the resolution during the method.

[0099] Indeed, the method according to the present disclosure ensures that the material does not receive the same amount of energy in the upskin portion compared to the downskin portion, and the method provides a sufficient amount of energy to the material that is or will be located at the junction of two successive layers on the upwardly facing second surface.

[0100] Additionally, the method according to the present disclosure allows for the creation of sublayers having a thickness less than the thickness of the layer on which they are built.

[0101] The above also applies to manufacturing ophthalmic devices that are constructed strictly vertically, without tilt, and have at least one portion facing downwards, for example, it can be a PAL lens on the side of the second surface, where one portion of the second surface faces downwards even if the other portion of the second surface faces upwards.

[0102] In other words, the method according to the present disclosure may be performed for the manufacture of only a portion of an ophthalmic device.

[0103] In other variations, the ophthalmic device is constructed horizontally rather than vertically, and methods according to the present disclosure can be performed to obtain a second downward-facing surface opposite an upward-facing first surface with higher resolution.

[0104] It should be noted that the ophthalmic device may be an ophthalmic lens for eyeglasses or any other device adapted to a wearer and having ophthalmic properties.

[0105] It should also be noted that the additive manufacturing method may be carried out by any existing suitable technique, for example in accordance with the techniques included in the definitions set out in the reference ISO / ASTM 52900:2021 or corresponding references.

[0106] More generally, it should be noted that the present disclosure is not limited to the examples described and illustrated.

Claims

1. A method for additively manufacturing an ophthalmic device (2) having a first surface (50), a second surface (55) opposite the first surface, and a contour joining the first surface and the second surface, the method comprising: additively manufacturing a plurality of layers (3) of a predetermined material to obtain the ophthalmic device, each layer being manufactured by projecting and polymerizing at least one image onto a surface of a volume of the predetermined material, the first surface facing downward and the second surface facing upward; and forming, for at least two consecutive layers, at least one image that allows hardening a predetermined thickness of material on the side of the second surface facing upward and another thickness of material on the side of the first surface facing downward.

2. The method of claim 1 , wherein the ophthalmic device (2) is constructed vertically and at an angle.

3. 3. The method of claim 1 or 2, wherein at least a portion of a sublayer of material is formed at the junction of two successive layers on the side of the first surface facing substantially downward, the sublayer having a thickness less than the thickness of the layer to be constructed.

4. 4. The method of claim 1, comprising a layer-forming step of adding a volume of the predetermined material, followed by steps of projecting and polymerizing at least one image onto a surface of the added volume of the predetermined material, wherein during the layer-forming step, the volume of the predetermined material is the same for each layer.

5. 5. The method of any one of claims 2 to 4, wherein additive manufacturing of multiple layers of a predetermined material is performed along a stacking axis (S) that is substantially vertical, and the ophthalmic device (2) is constructed vertically and includes an optical axis separate from the stacking axis.

6. 6. The method of claim 5, comprising additively manufacturing a support on which the ophthalmic device is built vertically and at an angle, the support including a support surface having a predetermined angle relative to the stacking axis.

7. The method of any one of claims 1 to 6, wherein the ophthalmic device is constructed to a diameter or profile of the ophthalmic device.

8. 8. The method according to claim 1, comprising forming at least one image that allows hardening the predetermined thickness of material on the side of the second surface (55) facing upward and the other thickness (60) of material on the side of the first surface (50) facing downward, and slicing one or more images.

9. 8. The method according to claim 1, further comprising forming at least one image that allows hardening the predetermined thickness of material on the side of the second surface (55) facing upward and the other thickness (60) of material on the side of the first surface (50) facing downward, and deforming the shape of one or more of the slice images.

10. 10. The method of claim 8 or 9, wherein a plurality of sliced ​​images are projected sequentially.

11. 10. A method according to claim 8 or 9, wherein at least one so-called greyscale image is projected.

12. A method according to any one of claims 1 to 11, comprising varying the polymerization energy during curing.

13. A manufacturing system configured to perform a method for additively manufacturing an ophthalmic device (2) having a first surface (50), a second surface (55) opposite the first surface, and an outline joining the first surface and the second surface, and additively manufacturing multiple layers (3) of a predetermined material to obtain the ophthalmic device, wherein each layer is manufactured by projecting and polymerizing at least one image onto a surface of a volume of the predetermined material, the first surface facing downward and the second surface facing upward, and the manufacturing system includes a projection and polymerization apparatus (15) configured to form at least one image that enables hardening of a predetermined thickness of material on the side of the second surface facing upward and another thickness of material on the side of the first surface facing downward for at least two consecutive layers.

14. 14. The manufacturing system of claim 13, further comprising a layer forming device configured to apply a volume of the predetermined material, and thereafter, the projection and polymerization device projects and polymerizes at least one image onto a surface of the applied volume of the predetermined material.

15. 15. The manufacturing system according to claim 13 or 14, wherein the projection and polymerization device is formed by a digital light processing unit and / or a stereolithography unit including a laser source and a scanning head, optionally including a controller configured to form a plurality of slice images and / or at least one so-called greyscale image and / or to vary the polymerization energy during curing.

Images