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), comprising additive manufacturing of a plurality of layers (3) made of a predetermined material in order to obtain the ophthalmic device, each layer being manufactured by projecting and polymerizing at least one image on a surface of a volume of the predetermined material, the first face (50) points downwards and the second face (55) points upwards; wherein, for at least two successive layers, the method comprises a step of forming at least one image that allows curing of a predetermined thickness of material on the side of the second face directed upward and curing of another thickness of material on the side of the first face directed downward.

Description

Technical Field

[0001] The present disclosure relates to a method for additively manufacturing an ophthalmic device and a manufacturing system configured to perform such a method. Background Art

[0002] A known method for additive manufacturing of an ophthalmic lens comprises a curing step and a laminating step, which are performed successively in a manufacturing system comprising a curing device, a laminating device and a building platform positioned relative to a vat filled with a predetermined material. In this configuration, the top of the manufacturing system corresponds to the location of the curing device, and the bottom of the manufacturing system corresponds to the opposite side relative to the building platform.

[0003] For example, each ophthalmic lens is built layer by layer on a building platform that is movable relative to a vat containing a predetermined volume of material. The building platform is located at a predetermined position, a curing device comprising a radiation source performs a curing step of a first material layer, a laminating device performs a laminating step at least according to the displacement of the building platform, so that a new material layer with a predetermined thickness can be cured, and so on.

[0004] In other words, in this known method, a curing step is performed on a layer, for example a liquid for a plurality of ophthalmic lenses to be manufactured on a building platform. The liquid layer is thus hardened, followed by a laminating step to form a new liquid layer on the previously hardened layer of the plurality of ophthalmic lenses to be manufactured.

[0005] International application WO 2015004383 A1 discloses a method for additive manufacturing of an optical article, the method comprising the steps of providing a starting optical system and additively manufacturing a complementary optical element layer by layer on the starting optical element, the complementary optical element may be in a tilted position.

[0006] International application WO 2015086981 A1 discloses a method for the layer-by-layer additive manufacturing of an optical article, the method comprising the following steps: additively manufacturing an intermediate optical element in such a way that the intermediate optical element is inclined relative to a predetermined additive construction axis, called the layering axis, along which at least one material of a plurality of predetermined volume elements is deposited in order to enable a polishing step to be performed in a specific area.

[0007] International application WO 2018235209 A1 discloses a method for additively manufacturing optical products layer by layer from a photocurable resin using a micromirror device (e.g., a DMD (digital micromirror device)) to generate a desired shape of light flux for irradiating a 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 the DMD, in the projection area of ​​the photocurable resin, the intensity of the projection light in the portion corresponding to the area of ​​the micromirror itself is different from the intensity of the projection light in the portion corresponding to the area between adjacent micromirrors. Summary of the invention

[0008] The present disclosure relates to a method for additive manufacturing of an ophthalmic device that is simple and convenient to perform.

[0009] The present disclosure accordingly provides a method for additively manufacturing an ophthalmic device, the ophthalmic device having a first face, a second face opposite to the first face, and a contour line connecting the first face and the second face, the method comprising the step of additively manufacturing a plurality of layers made of a predetermined material in order to obtain the ophthalmic device, each layer being manufactured by projecting at least one image onto a surface of a volume of predetermined material and polymerizing it, the first face pointing downward and the second face pointing upward; wherein, for at least two consecutive layers, the method comprises the step of forming at least one image, the at least one image allowing a predetermined thickness of material on a side of the second face pointing upward to be cured and another thickness of material on a side of the first face pointing downward to be cured.

[0010] Due to the method according to the present disclosure, an ophthalmic device may be additively manufactured having a first resolution on a second face pointing upward and a second resolution on a first face pointing downward, the second resolution being higher than the first resolution.

[0011] A first face pointing downwards means that the first face points to the bottom of the manufacturing system and can therefore be referred to as a lower skin, whereas a second face pointing upwards means that the second face points to the top of the manufacturing system and can therefore be referred to as an upper skin.

[0012] In an embodiment, the method is performed without changing the orientation of the ophthalmic device during additive manufacturing, and the resolution also does not change during the method.

[0013] In fact, due to the method according to the present disclosure, the material does not receive the same amount of energy on the upper epidermis portion compared to the lower epidermis portion and in this method a sufficient amount of energy is provided on the material at the junction of two consecutive layers located or to be located on the second face directed upwards.

[0014] Due to the method according to the present disclosure, at least a part of the material sub-layer is formed substantially at the junction of two consecutive layers on the side of the downwardly directed first face.

[0015] In other words, the method according to the present disclosure allows the creation of sub-layers having a thickness less than the thickness of the layer being built.

[0016] The print steps or steps formed in the lower skin side are less than the layer-to-layer thickness in the bulk of the material.

[0017] The ophthalmic device can be constructed both vertically and in an inclined manner.

[0018] Due to the essentially vertical build, the resolution is the resolution on the layering axis, rather than the so-called "in-plane" resolution that depends on the resolution of the curing method. In addition, higher resolution means that the print steps are smaller.

[0019] In an embodiment, the method comprises a layering step for adding a volume of the predetermined material, followed by a step of projecting at least one image each time onto the surface of the added volume of the predetermined material and polymerizing it.

[0020] During the lamination step, the volume of the predetermined material is the same for each layer.

[0021] The step of additively manufacturing a plurality of layers of a predetermined material is performed along a vertical layering axis, and the ophthalmic device is constructed substantially vertically and includes an optical axis different from the layering axis.

[0022] The layering axis is orthogonal to the production plane.

[0023] The optical axis may be tilted relative to the production plane in a range between approximately +10° and approximately +55°.

[0024] Vertically built means that the ophthalmic device is not built along the thickness of the device, ie, from one of the first and second faces to the other, but rather along the diameter or profile of the ophthalmic device.

[0025] The method comprises the step of additively manufacturing a support on which the ophthalmic device is built vertically and in an inclined manner.

[0026] The support may be formed simultaneously with the ophthalmic device or may be pre-formed.

[0027] The support may include a retaining surface having a predetermined inclination relative to the layering axis.

[0028] The method comprises the steps of forming at least one image adapted to solidify a predetermined thickness of material on an upwardly directed second face and another thickness of material on a downwardly directed first face, and slicing one or more images.

[0029] The method comprises the steps of forming at least one image adapted to solidify a predetermined thickness of material on an upwardly directed second face and another thickness of material on a downwardly directed first face, and deforming one or more slice images.

[0030] Multiple slice images are projected sequentially.

[0031] A so-called grayscale image is projected.

[0032] The method may include the step of varying the energy of polymerisation during curing.

[0033] The present disclosure further provides a manufacturing system configured to perform a method for additive manufacturing an ophthalmic device, the ophthalmic device having a first face, a second face opposite to the first face, and a contour line connecting the first face and the second face, additively manufacturing a plurality of layers made of a predetermined material to obtain the ophthalmic device, each layer being manufactured by projecting at least one image onto a surface of a certain volume of the predetermined material and polymerizing it, the first face pointing downward and the second face pointing upward; wherein the manufacturing system includes a projection and polymerization device configured to form at least one image for at least two consecutive layers, the at least one image allowing a predetermined thickness of material on a side of the second face pointing upward to be cured and another thickness of material on a side of the first face pointing downward to be cured.

[0034] The manufacturing system further comprises a laminating device configured to add a certain volume of the predetermined material, after which the projection and polymerization device projects at least one image on a surface of the added volume of the predetermined material and polymerizes it.

[0035] The projection and polymerizing device is formed by a digital light processing unit and / or by a stereolithography unit comprising a laser source and a scanning head.

[0036] The system comprises a controller configured to form a plurality of slice images and / or at least one so-called grey scale image, and / or to vary the polymerisation energy during curing. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The description of the present disclosure now continues with a detailed description of the embodiments presented below, by way of non-limiting examples and with reference to the accompanying drawings.

[0038] Figure 1is a schematic diagram of a manufacturing system configured to implement a method for additively manufacturing an ophthalmic device.

[0039] Figure 2 is a block diagram illustrating steps of a method for additive manufacturing an ophthalmic device according to the present disclosure.

[0040] Figure 3 An ophthalmic device is shown.

[0041] Figure 4 Some steps of the additive manufacturing method according to the first embodiment are schematically shown.

[0042] Figure 5 Some steps of the additive manufacturing method according to the second embodiment are schematically shown. DETAILED DESCRIPTION

[0043] Figure 1 A manufacturing system 1 configured to implement a method for additively manufacturing an ophthalmic device 2 is schematically illustrated.

[0044] The manufacturing system 1 comprises a tank 10 filled with a volume of a predetermined material 11 suitable for manufacturing an ophthalmic device 2, such as a liquid resin for manufacturing spectacles.

[0045] 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 a predetermined material 11 .

[0046] In this respect, the manufacturing system 1 comprises a unit 12 , also called additive manufacturing unit, configured to project and polymerize at least one image on a surface 13 of a volume of predetermined material 11 in a tank 10 .

[0047] The additive manufacturing unit 12 may include a processing device 14 having, for example, a digital lighting processor configured to process single and / or multiple images or patterns.

[0048] The additive manufacturing unit 12 may further include a projection and polymerization device 15 configured to provide curing energy and having, 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 projected simultaneously and successively toward the material 11 in a single direction for each layer 3, and then polymerizing and hardening the material 11.

[0049] In a variant, the digital illumination processor and the polymerizing device are replaced by a laser source and a scanning arrangement configured to scan the surface 13 of the material 11 with the laser source.

[0050] exist Figure 1In the embodiment, 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 the bottom 17 of the tank 10. This arrangement allows to perform a so-called top-down process as explained below.

[0051] In another arrangement, the additive manufacturing unit may be located on the lower side of the tank and facing a complementary opening formed in the bottom of the tank. This other arrangement allows to perform a so-called bottom-up process as also explained below.

[0052] The manufacturing system 1 further comprises a building platform 20 at least partially immersed in the tank 10, a transparent plate 21, and a flexible separation membrane 22. Figure 1 2 is shown placed on and in contact with a transparent plate 21.

[0053] The flexible separation membrane 22 faces the building platform 20 , and the transparent plate 21 faces the additive manufacturing unit 12 .

[0054] The flexible separation membrane 22 is mechanically connected to a frame 30 of the production system 1 via the end 31 .

[0055] The transparent plate can be made of glass or plastic, and 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 (e.g., AF 2400 or AF 1600), or perfluoroelastomer (PFE), polypropylene (PP), polyethylene terephthalate (PET), perfluoroalkoxy (PFA), or also silicone, etc.

[0056] Therefore, 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 certain volume of predetermined material 11 in the groove 10, for forming each layer 3 of the ophthalmic device 2 on the building platform 20, so that each layer 3 formed and at least partially hardened is sandwiched between the building platform 20 and the flexible separation membrane 22.

[0057] In particular, the additive manufacturing unit 12 is capable of transferring an amount of energy suitable for triggering polymerization of the predetermined material to the surface of a volume of the predetermined material in the form of an image or pattern.

[0058] The additive manufacturing unit 12 comprises a controller configured to form a plurality of slice images and / or at least one so-called grayscale image.

[0059] The controller of the additive manufacturing unit 12 may also be configured to vary the energy during curing, also referred to as polymerization energy.

[0060] Manufacturing system 1 further comprises a moving unit 25 configured to move at least one of building platform 20 , transparent plate 21 , and frame 30 relative to each other.

[0061] Building platform 20 , transparent plate 21 , and flexible separation membrane 22 are each directly or indirectly mounted on rigid body 26 , and may also be movably mounted relative to rigid body 26 .

[0062] The moving unit 25 can act on the building platform 20, or on the transparent plate 21, or on the frame 30 partially carrying the flexible separation membrane 22, or on both. The moving unit 25 can act on the building platform 20, the transparent plate 21 and the flexible separation membrane 22 in a related or independent manner.

[0063] In particular, the mobile unit 25 may be configured to:

[0064] - raising or lowering the building platform 20 towards or away from the bottom 17 of the tank 10; and / or

[0065] - 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 building platform 20; and / or

[0066] Frame 36 mechanically connected to flexible separation membrane 22 is raised or lowered toward or away from bottom 17 of tank 10 to position at least a portion of flexible separation membrane 22 relative to both building platform 20 and transparent plate 21 .

[0067] In an alternative embodiment, moving unit 25 may be configured to raise or lower tank 10 relative to at least one of building platform 20 , transparent plate 21 , and frame 30 mechanically connected to flexible separation membrane 22 .

[0068] In another alternative embodiment, the apparatus lacks a membrane and instead includes a re-coater.

[0069] Figure 2 is a block diagram showing the main steps of a method for additive manufacturing of an ophthalmic device 2 performed as a result of the manufacturing system 1 as described above.

[0070] The method comprises successive steps 100 of additively manufacturing, layer by layer, a plurality of layers 3 made of a predetermined material 11 .

[0071] The main steps of the method include iterative lamination steps 101 and curing steps 102 to form the ophthalmic device 2 layer by layer.

[0072] The lamination step 101 is performed to position the components of the manufacturing system (including at least the building platform 20, the transparent plate 21 and the flexible separation membrane 22) in a building position, where only a predetermined material 11 of a predetermined thickness is provided between the flexible separation membrane 22 and the building platform 20 or a layer already formed on the building platform. The predetermined thickness of the predetermined material 11 corresponds to the thickness of the layer to be formed when solidified.

[0073] During the lamination step, the volume of the predetermined material may be the same for each layer or for at least two consecutive layers. In a variant, the volume of the predetermined material may vary.

[0074] The stacking step 101 may include a step 110 of moving the building platform 20 to a predetermined position, and / or a step 120 of moving the frame 30 mechanically fastened with the flexible separation membrane 22 relative to the building platform 20, and / or a step 130 of moving the transparent plate 21 relative to the building platform 20 and / or relative to the frame 30 mechanically fastened with the flexible separation membrane 22.

[0075] The curing step 102 comprises the step of projecting and polymerizing at least one image on the surface 13 of a 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 .

[0076] The curing step 102 comprises projecting a single image or a plurality of images projected simultaneously one after the other in a single direction towards the material 11, for example by means of a projection device 14. Such a process is generally referred to as a DLP process.

[0077] In a variant, the step of projecting the image comprises scanning the surface of the material by means of a laser source. Such a process is generally referred to as an SLA process.

[0078] Each layer 3 of the ophthalmic device 2 is formed or laminated on the building platform 20 or a previous layer thereon and at least partially hardened by curing, wherein the layer 3 is sandwiched between the building platform 20 or the previous layer and the flexible separation membrane 22 .

[0079] Figure 3 The orientation of the ophthalmic device 2 during its construction is shown. The ophthalmic device 2 is constructed vertically and in an inclined manner.

[0080] The ophthalmic device 2 to be manufactured has a first face 50 oriented downward and referred to as the lower epidermis, a second face 55 opposite the first face 50 , oriented upward and referred to as the upper epidermis, and a contour line connecting the first face 50 and the second face 55 .

[0081] According to this disclosure and Figure 4 and Figure 5As shown, for at least two consecutive layers, at least one image allows a predetermined thickness of material to be solidified on the second surface 55 pointing upward and another thickness of material to be solidified on the first surface 50 pointing downward, so that at least a portion of a material sublayer 60 is added at the junction of two consecutive layers 3 on the second surface 50 pointing upward.

[0082] It should be noted that another thickness is a thickness that is different from the predetermined thickness, and may be an additional thickness or more generally an additional thickness that is greater or less than the predetermined thickness.

[0083] Here, additive manufacturing of a plurality of layers made of a predetermined material is performed along a vertical layering axis S, and the ophthalmic device 2 may be constructed substantially vertically and include an optical axis (not shown) different from the layering axis S.

[0084] The layering axis S is orthogonal to the production plane P.

[0085] Thus, the optical axis may be tilted relative to the production plane P in a range between approximately +10° and approximately +55°.

[0086] Vertically built means that the ophthalmic device 2 is not built in thickness, ie, from one of the first face 50 and the second face 55 to the other, but rather is built along a diameter or contour of the ophthalmic device 2 .

[0087] A support (not shown) may be additively manufactured, for example, simultaneously with or in advance of the ophthalmic device 2 , on which the ophthalmic device is built vertically and in an inclined manner.

[0088] The support may include a retaining surface having a predetermined inclination relative to the layering axis.

[0089] Sublayers 60 may be added according to different strategies.

[0090] The method may include the steps of forming at least one image that allows for curing of a predetermined thickness of material on the second face pointing upward and another thickness of material on the first face pointing downward, and slicing one or more images.

[0091] In a variant, the method may include: a step of forming at least one image that allows solidification of a predetermined thickness of material on the second face pointing upward and solidification of another thickness of material on the first face pointing downward; and a step of deforming the one or more slice images.

[0092] A plurality of slice images may be projected sequentially, or a so-called greyscale image may be projected (see below for more details).

[0093] In addition, the method may include a step of changing the polymerization energy during curing. Such a step is disclosed, for example, in WO 2018235209A1.

[0094] For example, in Figure 4 In the example of FIG. 1 , a sublayer 60 is included in the current layer 3. At some points of the projected image, the curing energy is adapted so that the curing thickness is less than the layer thickness. Graphically, the image will have "white parts" while the sublayer will appear "grey". Hereinafter, the sublayer 60 is overlapped with the layer 3.

[0095] For example, in Figure 5 In the projected image, a sublayer 60 is included in the previous layer 3, i.e. the layer formed in the previous step. At some points of the projected image, the curing energy is adapted so that the corresponding thickness of the cured material is greater than the sum of another thickness (also called overcuring) and the layer thickness. Graphically, the image will be gray, while the sublayer will be, for example, additional brightness and will appear white.

[0096] Grayscale means that the image is projected with a potentially different level of light intensity for each pixel of the device.

[0097] A gray scale with two gray levels may be used, for example 256 / 256 for white and 128 / 256 for gray.

[0098] To create the images, one possibility is to define a first image by slicing at a regular slice height (the first dedicated pixels will be 256) and a second image by slicing at an intermediate slice height (the second dedicated pixels will be 128) and then combine the two images.

[0099] Another way to produce sub-layers is to project different images with different projectors sequentially or simultaneously with different light doses to achieve different cured thicknesses. To create an image, sub-slicing can be done like a grayscale image.

[0100] In an embodiment, to produce an ophthalmic lens vertically, the lens is tilted in such a way that one side is completely in the upper epidermis and the other side is completely in the lower epidermis.

[0101] The resolution may be chosen depending on the complexity of the part or the level of detail to be achieved. For ophthalmic lenses, complex designs such as progressive lenses require high resolution. Simpler designs such as single vision lenses are less critical and require less resolution. In some cases, progressive lenses consist of a fairly simple front side (convex side) and a complex back side (including customization of the lens). Therefore, there are different needs in terms of resolution between the front side and the back side. This can be done using methods according to the present disclosure.

[0102] Due to the method according to the present disclosure, an ophthalmic device may be additively manufactured having a first resolution on a second face pointing upwards and a second resolution on a first face pointing downwards, the second resolution being higher than the first resolution.

[0103] Due to the essentially vertical build, the resolution is the resolution on the layering axis, not the so-called "in-plane" resolution. In addition, higher resolution means smaller print steps.

[0104] This method is performed during additive manufacturing without changing the orientation of the ophthalmic device, and the resolution likewise does not change during the method.

[0105] In fact, due to the method according to the present disclosure, the material does not receive the same amount of energy on the upper epidermis portion compared to the lower epidermis portion and in this method a sufficient amount of energy is provided on the material at the junction of two consecutive layers located or to be located on the second face directed upwards.

[0106] Furthermore, methods according to the present disclosure allow for the creation of sub-layers having a thickness that is less than the thickness of the layer being built.

[0107] The above also applies to manufacturing an ophthalmic device that is built strictly vertically without tilting and has at least one portion pointing downwards. For example, this can be a PAL lens on one side of the second face and a portion of the second face pointing downwards, even if other portions of the second face point upwards.

[0108] In other words, methods according to the present disclosure may be performed for manufacturing only a portion of an ophthalmic device.

[0109] In another variation, the ophthalmic device is not constructed vertically but horizontally and the method according to the present disclosure may be performed in order to obtain a second face pointing downwards with a higher resolution opposite the first face pointing upwards.

[0110] It should be noted that the ophthalmic device may be an ophthalmic lens for a spectacle lens or other device adapted to a wearer and having ophthalmic properties.

[0111] It should also be noted that the additive manufacturing method may be performed according to any existing suitable technology, such as those included in the definition given in reference ISO / ASTM 52900:2021 or corresponding references.

[0112] More generally, it should be noted that the present disclosure is not limited to the examples described and presented.

Claims

1. A method for additively manufacturing an ophthalmic device (2), the ophthalmic device having a first face (50), a second face (55) opposite to the first face, and a contour line connecting the first face and the second face, the method comprising additively manufacturing a plurality of layers (3) made of a predetermined material in order to obtain the ophthalmic device, each layer being manufactured by projecting at least one image onto a surface of a volume of the predetermined material and polymerizing it, the first face pointing downward and the second face pointing upward; wherein, For at least two successive layers, the method comprises forming at least one image which allows curing of a predetermined thickness of material on the side of the second face pointing upwards and of another thickness (60) of material on the side of the first face pointing downwards.

2. The method according to claim 1, wherein: The ophthalmic device (2) is constructed vertically and in an inclined manner.

3. The method according to claim 1, wherein: Essentially at the junction of two consecutive layers on the side of the first face pointing downwards at least a portion of a material sublayer is formed which has a thickness which is smaller than the thickness of the layer being built up.

4. The method according to any one of claims 1 to 3 comprises stacking to add a certain volume of the predetermined material, after which at least one image is projected each time onto the surface of the added volume of the predetermined material and polymerized, and during the stacking, the volume of the predetermined material is the same for each layer.

5. The method according to any one of claims 2 to 4, wherein: Additive manufacturing of a plurality of layers of a predetermined material is performed along a substantially vertical layering axis (S), and the ophthalmic device (2) is constructed vertically and includes an optical axis different from the layering axis.

6. The method of claim 5, comprising additively manufacturing a support on which the ophthalmic device is built vertically and in an inclined manner, the support comprising a retaining surface having a predetermined inclination relative to the delamination axis.

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

8. The method according to any one of claims 1 to 7, comprising forming at least one image, wherein the at least one image allows the material of the predetermined thickness on the side of the second surface (55) pointing upward to be solidified, and the material of the other thickness (60) on the side of the first surface (50) pointing downward to be solidified; and slicing one or more images.

9. The method according to any one of claims 1 to 7 comprises forming at least one image, wherein the at least one image allows solidification of the material of the predetermined thickness on the side of the second surface (55) pointing upward and solidification of the material of the other thickness (60) on the side of the first surface (50) pointing downward; and deforming the shape of one or more slice images.

10. The method according to claim 8, wherein: Multiple slice images are projected sequentially.

11. The method according to any one of claims 8 and 9, wherein: At least one so-called grayscale image is projected.

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

13. A manufacturing system configured to perform a method for additively manufacturing an ophthalmic device (2), the ophthalmic device having a first face (50), a second face (55) opposite to the first face, and a contour line connecting the first face and the second face, additively manufacturing a plurality of layers (3) made of a predetermined material to obtain the ophthalmic device, each layer being manufactured by projecting at least one image onto a surface of a certain volume of the predetermined material and polymerizing it, the first face pointing downward and the second face pointing upward; wherein, The manufacturing system comprises a projection and polymerization device (15) configured to form at least one image for at least two successive layers, the at least one image allowing a predetermined thickness of material to be solidified on one side of the second face pointing upwards and another thickness of material to be solidified on one side of the first face pointing downwards.

14. The manufacturing system according to claim 13 comprises a stacking device, which is configured to add a certain volume of the predetermined material, after which the projection and polymerization device projects at least one image on the surface of the added volume of the predetermined material and polymerizes it.

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

Images