Method for additive manufacturing

Abstract

The invention relates to a component (1) of a spectacle frame and to a method for additive manufacturing of such a component (1) by stereolithography wherein the component (1) comprises at least one spectacle frame (3) having an inner edge (10) wherein an inner support structure (12) is manufactured together with the spectacle frame (3) so as to support the spectacle frame (3), wherein the inner support structure (12) of the manufactured component (1) is connected to the inner edge (10) at at least two opposite points (14) such that these points (14) are supported relative to each other, and wherein the surface (5) of the component (1) has at least one connection region (7) wherein the connection region (7) is hidden in the use position of the finished spectacle frame, and wherein an outer support structure (9) is provided, the outer support structure is produced together with the component (1), a connection between the outer support structure (9) and the component (1) is established in a connection region (7), and the production of the inner support structure (12) is started once a connection has been established between the outer support structure (9) and the component (1).

Description

Technical Field

[0001] The invention relates to a method for additively manufacturing a component of an eyeglass structure by stereolithography, wherein the component comprises at least one eyeglass frame having an inner edge, wherein an inner support structure for supporting the eyeglass frame is manufactured together with the eyeglass frame, wherein the inner support structure of the manufactured component is connected to the inner edge at least at two opposite points so that these points are supported relative to each other, wherein the surface of the component comprises at least one connection area, wherein the connection area is hidden in the use position of the finished eyeglass structure, wherein an outer support structure manufactured together with the component is provided, wherein the connection between the outer support structure and the component is created in the connection area. Background Art

[0002] It has been established that eyeglass structures can be manufactured by laser sintering. WO 2011 / 089208 A1 discloses a special surface treatment in this context.

[0003] Several attempts have also been made to use stereolithography to manufacture eyeglass structures or parts thereof. In this context, US2020 / 0164591A1 discloses a special geometry for protecting mechanical parts, in particular the edges in the temple connection area, during surface treatment.

[0004] One disadvantage of the known methods for additively manufacturing parts for eyeglass structures using stereolithography is the finishing process. It is necessary to process the inevitable connection points during this printing process so that they are no longer in the way and, if possible, are no longer visible on the finished product. However, this requires different local treatments of the surface and can therefore only be done manually. The required manual processing steps are an obstacle to the promotion of stereolithography for this application. Summary of the invention

[0005] The object of the present invention is to eliminate or at least reduce the disadvantages of the prior art.

[0006] According to the invention, the manufacture of the inner support structure starts after the connection between the outer support structure and the component has been created. In other words, the outer support structure is first built up to the connection area. Starting from the connection area, the manufacture of the component starts. At the earliest when the component has been manufactured up to at least one point of the inner edge of at least one eyeglass frame, the manufacture of the inner support structure can start from and be connected to this point or another point of the inner edge of at least one eyeglass frame, the at least one eyeglass frame being manufactured up to this point available later.

[0007] Due to this manufacturing sequence, all external support structures connected to the visible surface of the component can be omitted. At least one connection area can be located outside the visible surface of the component. It can be arranged that at least one connection area does not overlap with one of the visible surfaces of the component. In the use position of the manufactured eyeglass structure, the connection area can be hidden, for example, by the temple or veneer (for example, a bonded metal visor), so that it does not form part of the visible surface of the component. The visible surface is understood here as a surface that preferably only needs to meet aesthetic or physiological requirements. In other words, the surface of the component of the eyeglass structure produced by stereolithography is not visible in the connection area, but is veneered or hidden. The connection area can be arranged, for example, on the general functional surface, interface, inner surface, cutting surface, contact surface or support surface of the component. The connection area is used to connect the support structure to the component of the glasses. In the finished eyeglass structure, the connection area can include, for example, a connection with the temple. By making it possible to completely avoid the connection with the external support structure in the visible surface area of ​​the component, the final processing of the component can be significantly simplified and optionally fully automated. Since the visible surface thus contains no irregularities due to process-related support structures, a high-quality surface can be achieved by uniform surface treatment (cleaning and / or rinsing and / or grinding) of the visible surface. A uniform surface treatment can be achieved without manual work steps or interventions.

[0008] In the context of the present disclosure, a support structure refers to a structure that is manufactured (e.g. printed) together with a component but is not part of the component or the structure of the eyeglass. It is a process-related structure, which is required, for example, due to layer-by-layer manufacturing when using stereolithography. Support structures can, for example, hold or support component sections that are not yet connected due to layer-by-layer construction at the beginning of production. They also serve to connect the component to a possible building platform if the component should not be directly connected to the building platform due to its geometry. Support structures can also be called construction geometry, support geometry or sacrificial geometry. The fact that a support structure is manufactured together with a component does not necessarily mean that each layer must be manufactured in a single exposure step. A layer of a component can be exposed in a single exposure process, thus simultaneously with a layer of a support structure, or in several exposure processes, whereby, for example, a layer of a component can be exposed first and then, after a pause (e.g. 100 milliseconds), a layer of a support structure can be exposed.

[0009] In the present disclosure, an internal support structure refers to a support structure that supports an object (in this case, a component of an eyeglass structure) manufactured by additive manufacturing at at least two different points relative to each other. Therefore, forces are transmitted within the manufactured object via the internal support structure. In contrast, an external support structure refers to a support structure by which the manufactured object or the internal support structure is supported on an external surface that is not generated as part of the manufacturing process, typically a build platform. A coherent support structure can generally form an internal support structure and an external support structure. For example, depending on the direction of the force, the force can act on the inside or outside surface of the manufactured object. For example, the external support structure can absorb vertical forces that counteract gravity and act on horizontally spaced points of the manufactured object, so that horizontal force components can be absorbed within the object. This allows to counteract deformations, in particular to counteract different deformations between different sections of the object.

[0010] In this context, it is understood that at least two points at which the inner support structure is connected to the inner edge are arranged relative to each other. Therefore, these relative points are not adjacent. Instead, the tangents at the relative points of the inner edge should be parallel and spaced apart, or at an angle of at least 30°. The present disclosure is not limited to radially relative points at which these tangents are parallel and spaced apart, but also covers inner support structures arranged, for example, in the manner of corner struts.

[0011] The at least two points may, but need not, correspond to at least two distinguishable structures. For example, the inner support structure may be formed as a supporting strut between positions in two or more different areas of the inner edge. However, the inner support structure may also be continuously connected to the inner edge, for example along an arc between the at least two positions, or even continuously connected to the entire inner edge. In the manufactured component there is a connection between the inner support structure and the inner edge at at least two points. A corresponding connection may already be provided in the model of the component to be printed, or a small distance between the inner support structure and the inner edge may be provided in the model, which distance is bridged at certain positions or continuously during the manufacturing process by material expansion.

[0012] After the components of the eyeglass structure are completed, the inner support structure can be removed from the eyeglass frame. This removal can be done manually or automatically, for example by pressing it out of the eyeglass frame. The connection between the inner support structure and the eyeglass frame is such that the inner support structure can be removed without damaging the eyeglass frame, so that the entire component is not damaged. In addition, the inner support structure does not leave any residue on the visible surface of the component that has never been connected. The inner edge of the eyeglass frame is not a visible surface, at least in the area connected to the inner support structure, but is hidden by the lens in the use position of the finished eyeglass structure with at least one lens. The inner edge can, for example, include a depression or a groove, whereby the point where the inner support structure is connected to the inner edge can be located in the depression or groove, for example in the center of the groove or at the edge of the groove. Alternatively, the inner edge can, for example, include a step or be flat instead of a depression or groove. In these cases, the inner support structure can also be connected to the inner edge.

[0013] According to the definition used herein, glasses comprise a glasses structure and at least one glasses lens. The glasses lens or multiple glasses lenses are usually framed in the finished glasses structure. The present disclosure only relates to the manufacture of the glasses structure. The glasses structure comprises at least one glasses frame. The glasses frame is a part or section of the glasses structure that at least partially surrounds at least one lens. The glasses frame corresponds to a complete or partial frame surrounding at least one lens. The glasses structure may include one or more components.

[0014] For example, the eyeglass frame can be manufactured as one component, and the two temples can be manufactured as other components and then assembled into an eyeglass structure. The present disclosure relates to components of an eyeglass structure, which includes at least one eyeglass frame, i.e. for at least one eyeglass lens. This can be the only component of the eyeglass structure or one of several components. The present disclosure also includes eyeglass structures without temples or with only one temple.

[0015] Optionally, during the manufacturing process, the two relative points can be arranged substantially on a horizontal line, or during the manufacturing process, the imaginary connecting line can form an angle of less than 60°, in particular less than 45°, with a horizontal line passing through the two relative points. One object of the present disclosure is to improve the stability of unfinished parts during the manufacturing process. It is advantageous if the layer of the inner support structure exposed at a certain point in time during the manufacturing process is connected to the inner edge on both sides. This allows the use of a thin, therefore material-saving support structure, which itself is subjected to as little deformation as possible. The angle formed with the horizontal line also depends on whether the layer exposed during the exposure is itself arranged horizontally or at a certain angle. The two relative points can be arranged on a horizontal line at least temporarily, i.e. at least during a part of the manufacturing process, in particular before the eyeglass frame in question is fully manufactured.

[0016] The inner support structure may optionally be connected to the inner edge at a plurality of opposite points, wherein during the manufacturing process, the opposite points are each arranged substantially in pairs on a horizontal line. For example, the inner support structure may be made of a plurality of parallel support struts or a grid or lattice of support struts.

[0017] Alternatively, the inner support structure can be manufactured as a continuous disc. This has the advantage of simplifying the geometric planning of the inner support structure. The continuous disc can be continuously connected to the inner edge or include connections to the inner edge, for example at regular intervals.

[0018] For example, the inner support structure can substantially take up the position of a lens which can later be housed in a spectacle frame. This is a simple way of ensuring that in the position of use of the finished spectacle structure all points of connection with the inner edge are hidden by the lens.

[0019] Optionally, at least two inner support structures may be provided in the same eyeglass frame, the inner support structures being connected to the inner edge at respective other relative points, the two respective relative points being arranged substantially in a horizontal line during the manufacturing process. The inner support structures may optionally be connected to each other. Alternatively, the inner support structures may be formed as separate support structures.

[0020] For example, at least two inner support structures can be arranged in this context substantially in parallel and separated by a vertical distance during the manufacturing process. This can reduce material losses through the support structures compared to a continuous disk.

[0021] The assembly may optionally include two eyeglass frames connected by a bridge. The bridge may also optionally form a nose pad for the eyeglass structure. Each eyeglass frame is designed to accommodate a lens. For example, the assembly may be symmetrical with respect to a symmetry plane passing through the center of the bridge and substantially perpendicular to the bridge. Each of the two eyeglass frames may be manufactured with a separate inner support structure. The inner support structures of the two eyeglass frames may optionally be connected to each other. This connection may be achieved by an outer support structure or an inner support structure.

[0022] In this case, the bridge can be arranged vertically during the manufacturing process or can form an angle of at most 45° with the vertical. Thus, during the manufacturing process, the orientation of the component in space can be essentially suspended laterally. In other words, the longest extension axis of the manufactured component can be essentially vertical. For example, the orientation can be such that the axis through the connection area and the (intended) center of gravity of the manufactured component forms an axis angle of at most 45° with the vertical.

[0023] The outer support structure can optionally be made to be connected to the inner support structure. This allows the inner support structure to be supported externally, for example on a build platform. This makes it possible to transfer some of the forces acting on the inner support structure (particularly gravity) to the outside.

[0024] In this way, the forces absorbed by the component can be reduced.

[0025] The component and the inner support structure can be made of the same material. The material can be a light-curing material, in particular a material that cures under ultraviolet light. In general, the inner support structure can be made of a different material than the component. For example, it is possible to consider using a material that can be dissolved and washed away by a cleaning process. For example, using the same material can simplify the design and ensure that the plastic and mechanical properties are compatible in any state and that stress or accidental bonding will not occur. The material can optionally be transparent or colored.

[0026] In a similar manner and with the same effects and advantages, the invention also relates to a component of an eyeglass structure, wherein the component is produced by stereolithography, wherein the component comprises at least one eyeglass frame having an inner edge, wherein an inner support structure is arranged in the eyeglass frame and is connected to the inner edge at least at two opposite points so that these points are supported relative to each other, wherein the inner support structure is connected to an outer support structure.

[0027] In the disclosed component, the connection line through two opposite points can be arranged substantially perpendicular to the longitudinal extension of the outer support structure. For example, the outer support structure is optimized for absorbing gravity and the inner support structure is optimized for absorbing forces acting laterally thereon, which will be dissipated within the component to minimize the number of connection points of the outer support structure.

[0028] As already described in connection with the method and similar advantages, in the disclosed component it can also be provided that the inner support structure comprises a continuous disc. Optionally, in the disclosed component, the inner support structure can also substantially take up the position of a lens which can later be accommodated in a spectacle frame.

[0029] Furthermore, the surface of the component may comprise at least one connection area which is concealed in the use position of the finished eyeglass structure, the outer support structure being connected to the component in the connection area.

[0030] More generally and independently of the features defined above and in the claims, the present disclosure also comprises a method for additively manufacturing a component of an eyeglass structure by stereolithography, wherein the component comprises at least one eyeglass frame having an inner edge, wherein a surface of the component comprises at least one connection area, wherein the connection area is hidden in the position of use of the finished eyeglass structure, wherein the component is manufactured starting from the connection area, wherein during the manufacturing process an axis through the connection area and the (intended) center of gravity of the manufactured component forms an axis angle of at most 45° with a vertical line, wherein a support structure for supporting the eyeglass frame is manufactured together with the eyeglass frame, wherein the support structure of the manufactured component is connected to the inner edge at at least one point, wherein a tangent to the inner edge at this point forms an edge angle of at most 45° with the axis.

[0031] The component can be directly connected to the building platform or to the external support structure to be prefabricated in the connection area. The axis angle can be a maximum of 40°, in particular a maximum of 35°, in particular a maximum of 22.5°. The smaller the axis angle, the lower the torque in the connection area when the component is completed. Since the center of gravity of the unfinished component naturally moves during the manufacturing process, a non-zero axis angle can be advantageous. In particular, the contact angle can be a maximum of 40°, in particular a maximum of 35°, in particular a maximum of 22.5°. The inner edge area defined by the edge angle includes at least all vertical lines during the manufacturing process. The support of the support structure at these points mainly absorbs shear forces. One advantage of the support in this area is that the spring deflection formed by the unfinished (e.g. not yet fully cured) component is reduced. This can offset the different expansion of the frame parts, which may otherwise occur due to the generally asymmetric shape of the eyeglass frame relative to the vertical line. In this variant, the support structure can be an inner support structure or an outer support structure or a combination of both. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The present invention will be further described below with reference to particularly preferred embodiments (to which the present invention is not limited) and with reference to the accompanying drawings. The accompanying drawings show in detail:

[0033] Figure 1 and Figure 2 Schematically illustrates the components of the eyeglass structure according to the first embodiment of the present disclosure after the components are manufactured on the building platform;

[0034] Figure 3 and Figure 4 Schematically showing several extended embodiments of corresponding several components of several eyeglass structures;

[0035] Figure 5 schematically shows a front view of components of a spectacle structure according to a third embodiment;

[0036] Figure 6 Schematically shows the cross-sectional line VI-VI according to Figure 5 a cross-sectional view of a component; and

[0037] Figures 7 to 9 There is no basis for building a platform Figure 1 Further views of components of . DETAILED DESCRIPTION

[0038] Figure 1 and Figure 2A component 1 of an eyeglass structure is shown. The component 1 is manufactured using stereolithography. The component 1 comprises two eyeglass frames 2, 3. The two eyeglass frames 2, 3 are connected by a bridge 4. A surface 5 of the component 1 comprises a visible surface 6 and two connection areas 7, 8. The connection areas 7, 8 are respectively used for connection to temples, for example by hinges. When the finished eyeglass structure is in the use position, the connection areas 7, 8 are hidden by the connected temples. An external support structure 9 is connected to the component in the two connection areas 7, 8.

[0039] Each spectacle frame 2, 3 comprises an inner edge 10. An inner support structure 11, 12 in the form of a continuous disk is arranged in each of the two spectacle frames 2, 3. In each case, the inner support structure 11, 12 takes the place of a lens, which can later be accommodated in the spectacle frame 2, 3. The inner support structure 11, 12 is connected to the inner edge 10 all around, although due to the manufacturing process, the connection may be interrupted in certain places. The spectacle frame 2, 3 itself is therefore supported over the entire circumference of the inner edge 10. In each of the two spectacle frames 2, 3, an inner support structure 11, 12 is arranged, which is in each case also connected to the outer support structure 9. The component 1 itself as well as the outer support structure 9 and the inner support structures 11, 12 are made of the same light-curing material.

[0040] Due to the two-dimensional continuity of the two inner support structures 11, 12, several pairs 13 of relative points 14 can be identified at which the inner support structures 11, 12 are connected to the inner edge 10. In at least some of these pairs 13 of relative points 14, an imaginary connecting line 15 can be drawn through two corresponding relative points 14, wherein the imaginary connecting line 15 is arranged substantially perpendicular to the longitudinal extension 16 of the outer support structure 9.

[0041] exist Figure 1 and Figure 2 In the position shown, the component 1 is shown suspended from the building platform 17 or standing on the outer support structure 9. In this position, the bridge 4 forms an angle of less than 20° with the vertical line 18. During the manufacturing process, the building platform 17 can be located in a horizontal plane and moved vertically step by step to produce each layer. Therefore, during the manufacturing process, at least some of the relative points 14 are arranged in pairs on the horizontal line 19.

[0042] exist Figure 3 and Figure 4 As shown in FIG. 1 , on the building platform 17 , several components 1 (9 in this example) can be manufactured simultaneously in one manufacturing process.

[0043] Figure 5 Shows the Figure 1A front view of a component 20 constructed in a similar manner. It can be clearly seen that an inner support structure 23, 24 is provided in each of the two spectacle frames 21, 22, which takes the place of the lenses which are later accommodated in the spectacle frames 21, 22. Figure 6 The edge shown Figure 5 In the cross section along line VI-VI in FIG. 2 , it can be seen that the eyeglass frame 21 includes a groove 26 in the inner edge 25. The inner support structure 23 is connected to the inner edge 25 in the groove 26. Therefore, the visible surface 27 of the component 20 has no connection with the inner support structure 23 and any outer support structure (see FIG. 2 ). Figures 1 to 4 ). In addition, Figure 6 It can be seen from the figure that the cross section of the inner support structure 23 is significantly smaller than the cross section of the eyeglass frame 21 .

[0044] Figures 7 to 9 Shows Figure 1 and Figure 2 A further view of the component 1 is shown, including its inner and outer support structures. Fig. 9 In the diagram, the shape of the outer support structure 9 and the connection areas 7 , 8 can be clearly seen.

Claims

1. A method for additively manufacturing a component (1) of an eyeglass structure by stereolithography, wherein the component (1) comprises at least one eyeglass frame (3) having an inner edge (10), wherein an inner support structure (12) for supporting the eyeglass frame (3) is manufactured together with the eyeglass frame (3), wherein the inner support structure (12) of the manufactured component (1) is connected to the inner edge (10) at least at two opposite points (14) so ​​that these points (14) are supported relative to each other, wherein a surface (5) of the component (1) comprises at least one connection area (7), wherein the connection area (7) is concealed in the position of use of the finished eyeglass structure, wherein an outer support structure (9) is provided, which is manufactured together with the component (1), wherein a connection between the outer support structure (9) and the component (1) is created in the connection area (7), It is characterized in that The production of the inner support structure (12) begins after the connection between the outer support structure (9) and the component (1) has been created.

2. The method according to claim 1, characterized in that During the manufacturing process, the two relative points (14) are basically arranged on the horizontal line (19), or during the manufacturing process, the imaginary connecting line (15) through the two relative points (14) forms an angle less than 60°, especially less than 45°, with the horizontal line (19).

3. The method according to claim 1 or 2, characterized in that: The inner support structure (12) is connected to the inner edge (10) at a plurality of opposite points (14) which are arranged substantially in pairs on a horizontal line (19) during the manufacturing process.

4. The method according to any one of claims 1 to 3, characterized in that The inner support structure (12) is manufactured as a continuous disc.

5. The method according to any one of claims 1 to 4, characterized in that The inner support structure (12) substantially takes up the position of a spectacle lens which can later be accommodated in the spectacle frame (3).

6. The method according to any one of claims 1 to 5, characterized in that At least two inner support structures are provided in the same eyeglass frame, the inner support structures being connected to the inner edge at different relative points, the two relative positions being arranged substantially on a horizontal line during the manufacturing process.

7. The method according to claim 6, characterized in that During manufacturing, the at least two inner support structures are substantially parallel and separated by a vertical distance.

8. The method according to any one of claims 1 to 7, characterized in that The assembly (1) comprises two eyeglass frames (2, 3) connected by a bridge (4).

9. The method according to claim 8, characterized in that During the manufacturing process, the bridge (4) is arranged vertically or forms an angle of maximum 45° with the vertical line (18).

10. The method according to any one of claims 1 to 9, characterized in that The outer support structure (9) is manufactured so as to be connected to the inner support structure (12).

11. The method according to any one of claims 1 to 10, characterized in that The component (1) and the inner support structure (12) are made of the same material, in particular a light-curing material.

12. Component (1) of an eyeglass structure, wherein the component (1) is produced by stereolithography, wherein the component (1) comprises at least one eyeglass frame (3) having an inner edge (10), wherein an inner support structure (12) is arranged in the eyeglass frame (3) and is connected to the inner edge (10) at least at two opposite points (14), so that these points (14) are supported relative to each other, wherein the inner support structure (12) is connected to an outer support structure (9).

13. The component (1) according to claim 12, characterized in that An imaginary connecting line (15) passing through the two opposite points (14) is arranged substantially perpendicular to the longitudinal extension (16) of the outer support structure (9).

14. Component (1) according to claim 12 or 13, characterized in that The inner support structure (12) comprises a continuous disc.

15. Component (1) according to any one of claims 12 to 14, characterized in that The surface (5) of the component (1) comprises at least one connection area (7) which is concealed in the use position of the finished eyeglass structure and in which the external support structure (9) is connected to the component (1).

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