Method and device for creating layer data for the layer-by-layer additive manufacturing of an object

Abstract

The invention relates to a method for creating layer data (S) for the layer-by-layer additive manufacturing of an object (2) from a geometric model (M) by solidifying manufacturing layers (F), said method comprising the steps of: providing model space data (D) comprising at least geometric data of the model (M) and / or a negative mask of the model (M); defining a scanning specification which indicates how a model space (M) is scanned in different scanning areas (A1, A2, A3, A4); creating a subset (B) for each scanning area (A1, A2, A3, A4), wherein the model space data (D) is scanned in the scanning areas (A1, A2, A3, A4) and the parts of a scanning area (A1, A2, A3, A4) in which the model space data (D) has the same predefined spatial relationship to the model (M) are assigned to the respective subset (B); generating a number of target sets by combining created subsets (B) of difference scanning areas (A1, A2, A3, A4); creating layer data (S) for a plurality of manufacturing layers (F), wherein at least one of the manufacturing layers (F) is assigned a printing area based on a number of the target sets. The invention also relates to a device, layer data, a control unit and a manufacturing device.

Description

[0001] Method and device for creating layer data for layer-by-layer additive manufacturing of an object

[0002] The invention relates to a method and a device for creating layer data for layer-by-layer additive manufacturing of an object from a geometric model by solidifying manufacturing layers, corresponding layer data, a control device for a manufacturing device for additive manufacturing of an object in a manufacturing process and a manufacturing device.

[0003] Additive manufacturing of objects has become increasingly important in recent years. This manufacturing method involves creating objects (components, jewelry, functional parts, or other items) layer by layer by solidifying a build-up material. This build-up material can be a powder, a filament, or a liquid. Solidification is often achieved using radiation or heat, but can also be accomplished with lacquer or adhesive.

[0004] Before an object is manufactured, a model of that object is created. This can be done purely virtually in a CAD program or by measuring a real object, for example, using laser scanning. The model is then virtually divided into layers, and a solidification pattern is defined for each layer. Process control data is derived from this solidification pattern, which can be very complex, and used for the layer-by-layer manufacturing of the object. In practice, the model is decomposed into parallel layers starting from its lowest surface, with the thickness (or spacing) of these layers corresponding to the thickness of the subsequent manufacturing layers of the object.

[0005] For simple models, this type of layer decomposition is unproblematic; however, it can happen that an object surface has a certain degree of roughness. In this case, it may occur that only the outermost contact points are considered in a layer, meaning that this layer is not continuous but consists of small patches.

[0006] Problems can also arise with fine structures within the component. These can be completely ignored, for example, if they do not happen to intersect exactly one layer, or they can lead to surface breakage, for example, if a thin wall has a very slight inclination to the layer plane. It is an object of the present invention to provide a method and a device for generating layer data for the layer-by-layer additive manufacturing of an object, layer data, a control device for a manufacturing apparatus for the additive manufacturing of an object, and a manufacturing apparatus, with which the disadvantages described above are avoided.

[0007] This problem is solved by a method according to claim 1, a device according to claim 11, layer data according to claim 12, a control device according to claim 13 and a manufacturing device according to claim 14.

[0008] A method according to the invention serves to create layer data for the layer-by-layer additive manufacturing of an object from a geometric model by solidifying manufacturing layers. It comprises the following steps:

[0009] - Providing model space data comprising at least geometric data of the model and / or a negative mask of the model,

[0010] - Defining a sampling rule that specifies how a model space is sampled in different sampling ranges,

[0011] - Creating a set of regions for each sampling region, whereby the model space data in the sampling regions are sampled and those parts of a sampling region in which the model space data have the same predefined spatial relationship to the model are assigned to the respective set of regions.

[0012] - Generating a number of target sets by combining created range sets from different sampling areas,

[0013] - Creating (and especially outputting) layer data for a large number of manufacturing layers, where at least one of the manufacturing layers is assigned a printing area based on a number of target quantities.

[0014] The layer data comprises information about the object in the manufacturing layers. Preferably, the layer data includes information about which areas of a manufacturing layer need to be solidified to obtain the object. Process control data for manufacturing the object can then be generated from the layer data. In conventional slicing, layer data is often also generated in an intermediate step, from which process control data is then generated. Therefore, layer data is generally known to those skilled in the art. The invention relates to a particular method for generating layer data. Within the framework of this method, it should be noted that a three-dimensional virtual geometric model ("model") is initially available, which can, for example, be created from a three-dimensional scan of a real object or using a CAD program. A real object, corresponding to the virtual model, is subsequently to be manufactured from this model.Once manufactured, this object consists of object layers that correspond to the manufacturing layers. Essentially, the manufacturing layers represent the areas that need to be solidified to form the object layers in order to complete the object.

[0015] First, the process requires data that represents the model ("model space data"). This is preferably the geometric data of the model and includes information about the three-dimensional shape of the model, i.e., its volume. However, it can also be a negative mask of the model, encompassing all those spatial regions of a given volume that do not belong to the model. In this case, the object would then be manufactured from the inverse set. The data can be in the form of CAD data; however, for understanding the invention and its advantages, it is helpful to imagine the model as a surface model with a rough surface, for example, because it was scanned from a real object using a laser.

[0016] The model space data preferably corresponds to the geometric data of the model. However, it can also be geometric data for a space in which the model is located. This means that it can additionally or alternatively include data about the surrounding space. It should be noted that a mask around the object ("negative mask") represents the object's outer shape. It is particularly preferred that the entire build space with all models is considered in order to create the optimal manufacturing layers. Therefore, the model space data preferably consists of geometric data for all models that are to be manufactured together in the build space and / or the space around the models (negative mask). In practice, models can be arranged in a virtual space whose dimensions and shape correspond to the build space. This virtual space, containing all the models to be manufactured, then preferably corresponds to the model data.

[0017] The sampling rule specifies how the model space, e.g., the model itself, is to be sampled. A possible, simple, but practically preferred sampling rule is: "All points with the Z-coordinate a." However, this involves multiple sampling regions. These are preferably (but not necessarily) completely disjoint. In the preceding example, the sampling regions could be different, parallel planes at different Z-coordinates. A preferred sampling rule in this respect would be, for example, the rule: "All points with the Z-coordinates a1, a2, a3,... each (with predefined, different ai)." Generally, a rule for sampling a surface model formed from triangles could also be: "All triangular faces on the underside of the surface model." A frequently used sampling rule is: "The intersection of a surface model or solid model with the slice plane."

[0018] The scanning procedure preferably depends on the manufacturing layers. If their positions are known beforehand, a scanning procedure can apply to each manufacturing layer, or a common scanning procedure can be used for all manufacturing layers. Preferably, parallel planes below and / or above a manufacturing layer are determined (e.g., via the Z-coordinate), particularly preferably closer than the nearest adjacent manufacturing layer, and the scanning procedure then specifies that scanning should take place on these planes.

[0019] In advance, the scanning specification is defined, which indicates in which scanning areas a model space—that is, the virtual space in which the model resides—is scanned. To understand this, one should consider the familiar process of slicing. There, too, scanning areas are defined, namely the slicing layers (manufacturing layers). Although the scanning areas are preferably planes ("scanning planes") that are aligned parallel to each other, and especially to the manufacturing layers, this is not strictly necessary. The scanning areas can also represent curved surfaces and / or intersect. Unlike normal slicing, the scanning areas can have different distances from each other. While not strictly necessary, this is a significant advantage. For example, when considering the subsequent manufacturing layers...one scanning area lies directly on a manufacturing layer, one very close above and one very close below it, and another scanning area is located somewhat further away.

[0020] The scanning specification can define all scanning areas in space, in particular their absolute positions and orientations. It can also define the scanning areas for each manufacturing layer, i.e., the relative distances and orientations of the scanning areas to the respective manufacturing layer. If the arrangement of the scanning areas is regular, the scanning specification can also include rules for the arrangement of the scanning areas, e.g., the position and orientation of the first scanning area (absolute or relative to a manufacturing layer), the orientation of the other scanning areas (e.g., parallel to the first), and a distance that each scanning area has to the preceding one. Within the scanning areas, the same process can then take place as in slicing, namely determining which portions of the model are located there to be manufactured. However, unlike normal slicing, other processes can also be performed.

[0021] If the sampling procedure is known, a set of regions can be created for each sampling region. It's important to note that this set of regions does not have to be contiguous, but can comprise a number of (possibly unconnected) surfaces, points, pixels, voxels, surface segments, or volume regions of the model. To do this, the model space data is sampled within the sampling regions (e.g., as in slicing). Those parts of a sampling region where the model space data has the same predefined spatial relationship to the model are then assigned to the respective set of regions.

[0022] A spatial relationship can be, in particular, "part of the model" or "within the model." This spatial relationship encompasses all areas belonging to the model's volume (preferably excluding cavities within the model). A (possibly further) spatial relationship can also encompass all areas outside the model (preferably including cavities within the model). A (possibly further) spatial relationship can encompass all areas lying on a boundary of the model. Here, it is preferred that this refers to all points in space whose nearest distance to the model's boundary is below a certain threshold distance. For example, if each point in space that is part of the model were assigned a "+", each point that is not part of the model a "+", and points on the model's boundary a "0", then all points in a sampling area bearing the same symbol could be assigned to a common set of areas.

[0023] If the spatial relationship is, for example, "all points belonging to the model," then the set of regions for a sampling area includes all points of the model that lie within that sampling area. This is essentially the intersection of the model with the relevant sampling plane. If, for example, the spatial relationship is "all points that do not belong to the model," then the set of regions for a sampling area includes all points outside the model (including its cavities) that lie within that sampling area.

[0024] The sampling areas can be visualized as planes, and the sets of areas as colored regions within these planes. The spacing between the sampling areas is preferably smaller than the distance between two manufacturing layers. Preferably, all sampling areas assigned to a manufacturing layer lie in the region between the manufacturing layers adjacent to that layer. If the sets of areas are known, a number of target sets are created by combining sets of areas from different sampling areas. Preferably, a group of sampling areas is assigned to a manufacturing layer, and the target set is created from the sets of areas within this group. This is then preferably done for a multitude of manufacturing layers. The sets of areas from the sampling areas assigned to each manufacturing layer are then combined to form a single target set.

[0025] Various set-theoretic mechanisms and / or logical operators can be used to create a target set. In a simple case, the target set can simply be the union of the domain sets of the desired sampling areas. The target set can also be formed by the inverse of the union of the domain sets of the desired sampling areas (e.g., if the model space data forms a negative mask of the model). The domain sets can also be weighted in the target set, for example, by weighting domain sets of sampling areas closer to a manufacturing layer more heavily than domain sets of more distant sampling areas, or vice versa. Alternatively, there may be multiple domain sets based on different spatial relationships, and a target set is then created after examining these different domain sets.

[0026] For a better understanding, imagine the target set as a union of regions, each containing points belonging to the model. The sampling regions from which these regions originate lie on and around a manufacturing layer. For example, if the bottom surface of the model is rough, a normal slicing process would result in an imperfect surface in the first manufacturing layer. If, however, two parallel sampling planes were used, positioned only slightly apart, one of the scanning planes might contain the imperfect surface as a region, and the other the closed surface. A union of these regions would again yield a closed surface.

[0027] Using these target sets, layer data can now be created for a multitude of manufacturing layers, in particular for all manufacturing layers necessary for building the object. At least one of the manufacturing layers, preferably all manufacturing layers or at least the lowest manufacturing layer, is assigned a printing area based on a number of target sets. In the preferred case that the target sets are unions containing the points belonging to the respective model, each manufacturing layer is preferably assigned a target set. It should be noted, however, that a target set can encompass one layer across the entire build space (i.e., potentially multiple objects), but a target set can also be created for each object, and then the target set of that object, or the target sets of several objects, can be arranged on a single manufacturing layer.Basically, one can say that for each production layer, the number of target quantities required to produce one layer for all objects to be manufactured in a production process is arranged.

[0028] An apparatus according to the invention serves to create layer data for the layer-by-layer additive manufacturing of an object from a geometric model by solidifying manufacturing layers. It comprises the following components:

[0029] - a data interface designed to receive model space data, including at least geometric data of the model and / or a negative mask of the model,

[0030] - a definition unit designed to define a sampling rule that specifies how a model space is sampled in different sampling ranges,

[0031] - a determination unit designed to create a set of areas for each sampling area, whereby the model space data in the sampling areas are sampled and those parts of a sampling area in which the model space data have the same predefined spatial relationship to the model are assigned to the respective set of areas,

[0032] - a target set unit designed to generate a number of target sets by combining created range sets from different sampling ranges,

[0033] - a layer data unit designed to create (and especially output) layer data for a multitude of manufacturing layers, wherein at least one of the manufacturing layers is assigned a printing area based on a number of target quantities.

[0034] The function of the device's components has already been described. The device is preferably designed for carrying out a method according to the invention.

[0035] Layer data according to the invention has been generated using a method according to the invention, preferably by means of a device according to the invention. It differs from other layer data in that the information of the manufacturing layers has been derived from the target quantities and is not merely an intersection of the manufacturing layers with the model. A control device according to the invention serves a manufacturing device for the additive manufacturing of an object in a manufacturing process in which build material, preferably a plastic powder or metal powder, is built up layer by layer in a build area, and selective solidification of the build material takes place between the application of two layers of build material by means of irradiation of the build material with at least one energy beam. The control device comprises a device according to the invention.

[0036] A manufacturing device according to the invention serves for the additive manufacturing of at least one object in an additive manufacturing process, comprising at least

[0037] - a feeding device for applying layers of building material in a build area into a process chamber,

[0038] - an irradiation device for selectively solidifying build-up material between the application of two material layers by irradiation with at least one energy beam, as well as

[0039] - a control device according to the invention.

[0040] The invention can be implemented, in particular, in the form of a computer unit with suitable software. The computer unit can, for example, comprise one or more cooperating microprocessors or the like. In particular, it can be implemented in the form of suitable software program components within the computer unit. A largely software-based implementation has the advantage that even previously used computer units can be easily retrofitted by a software or firmware update to operate according to the invention. In this respect, the problem is also solved by a corresponding computer program product with a computer program that can be directly loaded into a memory device of a computer unit, containing program sections to execute all steps of the method according to the invention when the program is run in the computer unit.In addition to the computer program itself, such a computer program product may include additional components such as documentation and / or additional components, including hardware components such as hardware keys (dongles, etc.) for using the software.

[0041] For transport to the computer unit and / or for storage on or in the computer unit, a computer-readable medium, such as a memory stick, a hard drive, or another portable or permanently installed data carrier, can be used, on which the program sections of the computer program that can be read and executed by a computer unit are stored. Further, particularly advantageous embodiments and developments of the invention will become apparent from the dependent claims and the following description, wherein the claims of one claim category can also be further developed analogously to the claims and description parts of another claim category, and in particular, individual features of different embodiments or variants can be combined to form new embodiments or variants.

[0042] Preferably, the scanning protocol specifies that the model space is scanned in different scanning planes. The scanning planes are preferably parallel to each other. Preferably, the positions of manufacturing layers are defined beforehand, and an individual scanning protocol or a common scanning protocol is used for a plurality of these manufacturing layers. The manufacturing layers are preferably parallel to each other.

[0043] In one embodiment of the method, it is preferred that several scanning planes are arranged parallel to a manufacturing layer. At least one scanning plane is arranged above the manufacturing layer and / or at least one scanning plane is arranged below the manufacturing layer. Preferably, scanning planes of a manufacturing layer above and below this manufacturing layer are equidistant from the manufacturing layer. Particularly preferred is a scanning plane located at the manufacturing layer. Preferably, the scanning planes of a manufacturing layer are situated between the manufacturing layers adjacent to it.

[0044] It is preferred that in one embodiment of the method, at least one geometric property indicates whether the relevant part of the model space lies within the model and / or at least one geometric property indicates whether the relevant part of the model space lies outside the model. It is further preferred that at least one additional geometric property indicates whether the relevant part of the model space lies on the boundary of the model. For example, markers (e.g., -, +, and 0) could be assigned to points in the model space, indicating whether a point is part of the model (-) or not (+) and, if applicable, whether a point lies on its boundary (0). Alternatively or additionally, at least one geometric property preferably indicates whether the relevant part of the model space lies at a distance below a predetermined limit value from the boundary of the model. In this variant, the property thus consists of a distance from the boundary of the model.This distance can be positive if the point lies outside the model, or negative if the point is part of the model. Preferably, points whose distance is less than this limit (e.g., within an interval of + / - 5 pm) are referred to as points lying on the boundary. In practice, a distance to the nearest boundary of a model is preferably calculated for points in the model space data and assigned to these points. Preferably, a signed distance field is created for this purpose, and upon union of the corresponding area sets, a function is established that yields a distance to the unioned contours.

[0045] It is preferred that, in one embodiment of the method, the model space data consists of a set of image elements in the form of points, pixels, voxels, or surface elements. For example, a distance function could be used to calculate the distance between an STL triangle and any point. The model space data can, in particular, include points with distance information ("as a property"). Preferably, each set of areas comprises those image elements that have the same spatial relationship to the model, and the set of areas preferably represents a mask of the corresponding sampling area containing the relevant image elements. Here, the term "mask" refers to a representation of the distance area based solely on the selected data.

[0046] Preferably, at least one first and one second set of target areas are created for each sampling area. Each first set of target areas is based on a first spatial relationship to the model, and each second set of target areas is based on a second spatial relationship to the model that differs from the first spatial relationship. For example, there is a "-" set of target areas for points within the model and a "+" set of target areas for points outside the model. Preferably, a number of first target sets are created by combining first sets of target areas created from different sampling areas, and a number of second target sets are created by combining second sets of target areas created from different sampling areas. For example, there is then a "-" set of target areas for points within the model and a "+" set of target areas for points outside the model. Most preferably, the layer data is created based on the first target set and / or the second target set.Preferably, one or both target sets are used to generate the layer data. For example, one can select a target set "within the object" and effectively "inflate" the object slightly, or select a target set "outside the object" and exclude the outer points of the surface. In both cases, a smooth surface results. It is also possible to create only one target set from one of the range sets. That is, one can decide in advance which range set must be used to generate a target set. In one embodiment of the method, it is preferred that a range set and / or a target set are generated based on at least two different spatial relationships.

[0047] It is preferred that:

[0048] - a first spatial relationship serves to select elements for a set of areas,

[0049] - a second spatial relationship serves to select elements for a range set,

[0050] - an intersection of both spatial relationships serves to select elements for a domain set, where one of the two spatial relationships serves to select elements for a different domain set,

[0051] - a target set is created from one of these domain sets by summarizing them based on a second spatial relationship,

[0052] - a target set is created from one of these range sets by summarizing them based on an intersection of both spatial relationships.

[0053] According to a preferred embodiment of the method, a target set is created by a weighted union of range sets, the weighting depending on the position of the different sampling areas of the range sets and / or the size of the range sets. This has the advantage that different sampling areas can have different influences on the layer data. It is preferred that the range sets comprise areas or points as set elements. It is particularly preferred that the total area or the number of points of a created target set is checked to see if it falls below a predetermined limit, and if so, the target set in question is considered empty.Alternatively or additionally, it is preferred that a check is performed to see if areas of the sets of areas to be combined into a target set are disjoint, and if so, a transition area is created in the target set between these areas, connecting them. Alternatively or additionally, it is preferred that a democratic check is performed for each point or area of ​​a set of areas, and if a plurality of corresponding points are found in the sets of areas, the point or area is included in the target set.

[0054] Preferably, for elements of a set of regions, particularly pixels or voxels, a distance to the edge of the model is calculated. This distance is then used to determine whether an element is assigned to the edge (e.g., if the distance is less than a threshold) and / or what weighting the set of regions receives when forming a target set. It is preferred that, in one embodiment of the method, at least the position of a lowest manufacturing layer is specified and the scanning procedure specifies several scanning planes parallel to this manufacturing layer, with the target set being a union of sets of regions. A distance A between two manufacturing layers is preferably specified.A number of scanning planes are then preferentially located in a first distance range from the position of the manufacturing layer, which is less than A / 10, and a number of scanning planes are located in a second distance range from the position of the manufacturing layer, which lies between A and A / 5. Thus, some of the scanning planes are located close to a manufacturing layer and others further away. Surface roughness can be compensated particularly well with the closer scanning planes, while fine structures between two manufacturing layers can be compensated with the more distant scanning planes.

[0055] The use of AI-based methods (AI: "Artificial Intelligence") is preferred for the method according to the invention. Artificial intelligence is based on the principle of machine learning and is generally implemented with a learning algorithm that has been trained accordingly. The English term "machine learning" is frequently used for machine learning, and this also includes the principle of "deep learning".

[0056] Preferably, components of the invention are provided as a "cloud service." Such a cloud service serves to process data, particularly using artificial intelligence, but can also be a service based on conventional algorithms or a service where human evaluation takes place in the background. Generally, a cloud service (hereinafter also referred to simply as "cloud") is an IT infrastructure in which, for example, storage space or computing power and / or application software is provided via a network. Communication between the user and the cloud takes place via data interfaces and / or data transmission protocols. In the present case, it is particularly preferred that the cloud service provides both computing power and application software.

[0057] In a preferred method, data obtained within the scope of the invention is provided to the cloud service via the network. This service comprises a computing system that typically does not include the user's local computer. The method can be implemented using a command structure within a network. The data processed in the cloud is subsequently sent back to the user's local computer via the network. A preferred method serves to decompose a three-dimensional geometric model into manufacturing layers for layer-by-layer additive manufacturing of an object according to the model. It is particularly advantageous for compensating for rough surfaces and comprises the following steps:

[0058] - Providing model data comprehensive information about the three-dimensional shape of the model,

[0059] - Defining a number of parallel, two-dimensional manufacturing layers with a distance A between them in the model,

[0060] - Assigning a plurality of two-dimensional scanning areas (referred to here as "scanning planes") to a number of manufacturing layers, wherein each scanning plane is parallel to the manufacturing layers and has a distance B to the manufacturing layer to which it is assigned, with 0 < B < A (preferably a scanning plane is located at the position of the manufacturing layer in question),

[0061] - Determine for each sampling plane the intersection of the model data and the respective sampling plane (as a range set),

[0062] - Combining the intersections of the sampling planes assigned to a manufacturing layer into a target set, for a number of manufacturing layers,

[0063] - Output of layer data from the manufacturing layers.

[0064] In the model, the manufacturing layers are defined, which are parallel to each other and have a particularly regular spacing A (the "layer thickness") between them. Defining manufacturing layers is known in the prior art and is performed by so-called "slicers." However, this is precisely where the problem described above arises: the outermost manufacturing layers, or manufacturing layers in the interior, only insufficiently cut the model in the area of ​​cavities. This means that, for example, on a rough surface, a surface pattern is recognized in a manufacturing layer instead of a complete surface. One could also consider a hollow sphere with a thin wall where the lower end lacks cohesion with the rest of the wall because it has been dimensioned too small.

[0065] For this reason, manufacturing layers are assigned a number of two-dimensional scanning planes. Although this problem primarily occurs in the outermost manufacturing layers, it is still preferable to assign scanning planes to each manufacturing layer, as problems can also arise with internal cavities or intricate structures. These scanning planes lie parallel to the manufacturing layers; thus, both the manufacturing layers and the scanning planes form an arrangement of parallel layers. Each scanning plane has a distance B from the manufacturing layer to which it is assigned. Here, 0 < B < A applies, meaning that the scanning planes assigned to a manufacturing layer do not lie beyond the next manufacturing layer, but always in the space between the respective manufacturing layer and the adjacent manufacturing layer.

[0066] For each manufacturing layer and each scanning plane, the intersection of the model (the geometric model data) and the respective layer is determined. For example, the system checks what proportion of the model's surface lies within the respective layer. This can be visualized as the model being cut at the position of a layer, and the cut surface being assigned as the intersection of the corresponding layer. A manufacturing layer located at the edge of a rough, flat surface (parallel to it) will exhibit a discontinuous surface pattern as its intersection due to the roughness. However, the intersection of an adjacent scanning plane may already be completely degraded (and correspond to the flat surface of the model) if this scanning plane lies outside the rough area.

[0067] Points within the model are often marked with a symbol (e.g., "-"). An intersection can then be created from a region in a layer containing these markers. If an intersection in a layer were represented in black, points in that layer would be colored black where that layer lies within the model. It should be noted that further information could be collected and stored as data for points within a layer. For example, all points outside the model in a layer could also be marked with a symbol (e.g., "+"), and possibly also points that lie exactly on a surface of the model (e.g., "0"). Distances to the nearest component surface could also be calculated for each point in a layer.

[0068] The geometric data can also include all points outside the model (such data also defines the model, for example, as all points outside this data). Therefore, it would also be possible to create intersections only from the "+" markers.

[0069] Once the intersections are known, the manufacturing layers are formed. In contrast to known methods, the inventive method assigns a combination of the intersections of the number of scanning planes assigned to a manufacturing layer as layer data. In the aforementioned example, where the manufacturing layer exhibited a discontinuous surface pattern, this is combined with the full-surface fill of the scanning plane, resulting in a substantially closed surface as desired. Once the manufacturing layers are known, their layer data is output, particularly for generating control data or for verification. This step is known and is also performed by conventional slicers, albeit without the aid of the scanning planes.

[0070] The layer data does not necessarily have to be used for control data, but could also be used to modify the model, e.g., to improve its surface structure. Here, for example, model data can be adapted to the manufacturing layers. In particular, with the embodiment mentioned above and described in more detail below using distance data, the surface of the model can be specifically improved or adapted.

[0071] A device according to the invention serves to decompose a three-dimensional geometric model into manufacturing layers for layer-by-layer additive manufacturing of an object corresponding to the model. It comprises the following components:

[0072] - a data interface designed to receive model data comprehensive information about the three-dimensional shape of the model,

[0073] - a definition unit designed to specify a number of parallel, two-dimensional manufacturing layers with a distance A between them in the model, and to assign a plurality of two-dimensional scanning planes to a number of manufacturing layers, where each scanning plane is parallel to the manufacturing layers and has a distance B to the manufacturing layer to which it is assigned, with 0 < B < A,

[0074] - a determination unit designed to determine for each sampling plane the intersection of the model data and the relevant sampling plane (as a range set),

[0075] - a target quantity unit designed to combine the intersections of the sampling planes assigned to a production layer into a target quantity, for a number of production layers,

[0076] - a layer data unit designed to create layer data for a multitude of manufacturing layers, wherein at least one of the manufacturing layers is assigned a printing area based on a number of target quantities.

[0077] - a data interface designed for outputting layer data from the manufacturing layers

[0078] The device is preferably designed for carrying out a method according to the invention.

[0079] The function of the device's components has already been described. According to a preferred embodiment of the method, at least two scanning planes are assigned to a manufacturing layer. Preferably, at least one scanning plane is located above the manufacturing layer and at least one scanning plane is located below the manufacturing layer. An exception could be made for the outermost manufacturing layers, but it is quite possible that areas of the model lie beyond the manufacturing layer, which would then be "detected" by the scanning plane.

[0080] Preferably, a scanning plane above the manufacturing layer and a scanning plane below the manufacturing layer have the same distance to the manufacturing layer. However, this is not strictly necessary. It is also preferred that all manufacturing layers have the same distance to their respective adjacent manufacturing layers, i.e., that they are arranged regularly. It is particularly preferred that the scanning planes are arranged identically for each manufacturing layer, meaning that there is essentially an ensemble consisting of a manufacturing layer and its associated scanning planes, the shape of which is repeated across all manufacturing layers.

[0081] It is preferred that, in one embodiment of the method, at least two scanning planes assigned to a manufacturing layer are located on one side of the manufacturing layer, and the distance of one scanning plane to the manufacturing layer is at least twice as large as the distance of the other scanning plane to the manufacturing layer, preferably at least five times as large, and particularly at least ten times as large. Thus, two or more scanning planes are assigned to a manufacturing layer on one side, and this can also apply to both sides of the manufacturing layer (see the embodiment described above). One scanning plane is located very close to the manufacturing layer, and another is located further away. It is particularly preferred that a "near" scanning plane and a "far" scanning plane are located above and below a manufacturing layer, respectively. The "near" scanning plane can, for example, compensate for surface roughness, and the "far" scanning plane can compensate for unevenness.

[0082] It is preferred that in one embodiment of the method a scanning plane is assigned to two manufacturing layers (e.g. one located exactly in the middle) and, when forming manufacturing layers, the intersection of this scanning plane is assigned to both manufacturing layers concerned as layer data.

[0083] However, it is advantageous to make the union of this intersection dependent on the intersections of other scanning planes within these manufacturing layers. Preferably, part of the intersection could be merged in one manufacturing layer and another part in the other. For example, if a thin, slanted structure runs through an object, its path could be detected by the other scanning planes of the manufacturing layers, and the portion of this structure in the common scanning plane could then be selectively distributed (possibly with an overlap) across the manufacturing layers.

[0084] According to a preferred embodiment, which is particularly advantageous when the object is created such that the first solidified manufacturing layer fills the space between the first and second manufacturing layers, and subsequent manufacturing layers i fill the space between the i-th manufacturing layer and the i+1-th manufacturing layer, scanning planes are preferably assigned to the manufacturing layers, which are located either predominantly above or predominantly below the manufacturing layers. However, in the case of delicate structures, it could also be advantageous to assign a scanning plane below the manufacturing layer if its distance is at most A / 5, preferably at most A / 10 (with the distance A of this manufacturing layer to the next manufacturing layer).

[0085] It is preferred that, in one embodiment of the method, a scanning plane associated with a first manufacturing layer is located closer to a manufacturing layer adjacent to that first manufacturing layer than to the first manufacturing layer itself. In this case, a scanning plane is thus located closer to a different manufacturing layer than to the manufacturing layer to which that scanning plane is assigned. This case is advantageous, for example, for very irregular downskin layers of the model. With such an arrangement of a scanning plane, it is preferred that the union of its intersection with the manufacturing layer assigned to it is weighted or conditional (only if a predefined condition is met).

[0086] For the most accurate possible reproduction of the component geometry, it is preferred that a scanning plane is always assigned to only one (single) manufacturing layer.

[0087] In a case where the component geometry is to be specifically modified so that a minimum component height prevails at every point, it is preferred that a manufacturing layer is also assigned a number of scanning planes that are further away than the layer distance between two manufacturing layers; in this case, it may also be advantageous to assign a scanning plane to several manufacturing layers.

[0088] It is preferred that, in one embodiment of the method, after determining the intersections, the respective intersection of a manufacturing layer and / or scanning plane is checked, and layer data of a manufacturing layer is created essentially at the position of this manufacturing layer based on this check. This check can lead to a weighted union, as already mentioned above. Preferably, the check can be directed at the progression of a structure in the model or the distribution of intersections in a plurality of scanning planes.

[0089] Preferably, the check is performed to see if the total area of ​​the intersection in a layer falls below a predetermined threshold. If the total coverage of the manufacturing layer and its associated sampling planes is less than a threshold (i.e., all layers show only "noise"), the manufacturing layer in question remains empty. Alternatively, it can be decided that only a portion of an intersection where too little area would be filled after a merge remains empty.

[0090] Preferably, either alternatively or additionally, it is checked whether the surfaces of the intersections of the manufacturing layer and a scanning plane are disjoint. In this case, a transition surface is created between these surfaces, which connects them. This is particularly advantageous for thin, skewed structures.

[0091] Preferably, either as an alternative or in addition, a democratic check is performed for each point in a production layer. This check verifies whether the point is contained in the intersection of the majority of the sampling planes assigned to that production layer. If a majority of corresponding points are present in the production layer and in its assigned sampling planes, the point is placed in the production layer. If not, the point is not placed. This democratic check can also be weighted, in particular by assigning different weights to predetermined sampling planes, e.g., according to their proximity to the production layer.

[0092] It is preferred that the first and last manufacturing layers have a different assignment of scanning planes than the other layers. The scanning planes beyond this, which can no longer see anything, are either omitted or not considered in the democratic review process.

[0093] It is preferred that, in one embodiment of the method, the intersections of the manufacturing layers and the scanning planes are combined during the forming of the manufacturing layers based on the verification, preferably with a weighted and / or averaged combination depending on the verification. In practice, one can visualize two layers with different black-colored areas (intersections) being superimposed, and the resulting total black area being considered the union of the intersections. However, this is only one possibility. Theoretically, all points outside the model in the layers could also represent the intersections.

[0094] Points on the edge of a model could be assigned an additional marker, e.g., "0". These points can be considered as lying inside the model, outside the model, or as special points, e.g., depending on the method used to evaluate special layers, as lying both inside and outside, or influencing a weighting.

[0095] According to a preferred method, at least two types of intersections in the layers are determined based on the geometric data. One type of intersection indicates whether a point lies inside the model, and another type indicates whether a point lies on the model's boundary. When combining the intersections to form the manufacturing layers, different types of intersections are then weighted differently.

[0096] According to a preferred embodiment, a distance to the nearest edge of the model is calculated for points in the layers (scanning planes and manufacturing layers) and assigned to these points. This distance can be a 3D distance in space or a 2D distance in the relevant plane. These points can be all points, only points outside the model (marked here with "+"), or only points inside the model (marked here with "-"). The intersections thus describe contours in a layer in the form of a signed distance field. In these distance fields, points outside and inside the contour can be identified by their sign ("+" or "-"). A value of 0 means that the point is located on the contour.

[0097] With regard to an edge (e.g., marker "0"), it is preferred to observe a tolerance range in the distances. All distances below a threshold value S (e.g., < 0.005 mm) are assigned to the edge and preferably receive a marker that identifies the edge of the model, e.g., "0".

[0098] Regarding the union of intersections (with intervals or distances), a function is preferably formulated that provides the distance to the unioned contours. Without weighting, a function to calculate the distance d of a point to layers A and B can be formulated, for example, as follows: d = min(distance-A, distance-B).

[0099] To weight the influence of B, for example, depending on the difference in layer height, a certain amount can be subtracted from the distance to B. The weighting function can then be set up with the weighting factor w as follows: d = min(Distance-A, Distance-B - w- (Height-B - Height-A))

[0100] The subtraction corresponds to offsetting the contour into the interior of the model. Instead of the minimum of both distances, a union function can also be used, which creates a smooth transition between the two contours; various functions are known for this purpose.

[0101] According to a preferred embodiment, the geometric data includes location information about the position or topology of a manufacturing layer (and / or analogously, a scanning plane). In this respect, points or surface sections of a layer (manufacturing layer or scanning plane) are assigned a marker (e.g., a number, an index, or a sign), depending on whether these points or surface sections are located on the surface, inside the model, or outside the model.

[0102] For example, points or surface sections on the model's surface are assigned the marker "0", those inside the model the marker "-", and those outside the model the marker "+" (see also previous examples). In this case, different points or surface sections of a manufacturing layer located at the edge of a rough, flat surface (parallel to it) are assigned different information depending on whether these points or surface sections are on the model's surface (marker "0"), inside the model (marker "-"), or outside the model (marker "+").When considering two scanning planes adjacent to this manufacturing layer, points or surface sections of one scanning plane are assigned markers corresponding to a point on the surface or inside the model (markers "0" or "-"), while points or surface sections of the other scanning plane are assigned markers corresponding to a position on the surface or outside the model (markers "0" or "+"). In this example, an intersection is a point or surface section of a manufacturing layer or scanning plane to which a specific piece of information (e.g., the number "-1") is assigned. An intersection can then be viewed in the areas with a common marker, e.g., for all points within the model. Two or three different areas can also be considered as distinct intersections (e.g., "inside," "outside," and "edge") and weighted differently when combined. For example, in a component where outward size deviations are worse than inward deviations, the outermost manufacturing layers could have their intersections (previously marked with the "+") combined, while the innermost manufacturing layers (previously marked with the """) would have their intersections combined. (designated). Different procedures can also be used for points on the boundary during a union.

[0103] If the layers contain different markers (different types of intersections), it is preferable to utilize this additional information when forming the intersections. Preferably, intersections with the same marker are merged according to the same criteria, while different criteria or hierarchies are applied to different markers. For example, all intersections with the marker "0" (i.e., indicating that the points or area segments lie on the surface) are merged as "0" only if other layers have the markers "0" or "+" at the relevant locations. If a layer contains the marker "-", the corresponding point is assigned to the merged "-" intersections.

[0104] A minimum of the signed distances to the individual islands is calculated in each layer with particular preference. Translated to the abstraction with the "information," this means that a point (x, y) belongs to the component / layer if the information is "-" or "0" (although it is a matter of definition whether "0" still belongs).

[0105] Furthermore, by combining the intersections, it is possible to assign points or surface sections to the interior or exterior of the model, e.g., by combining intersections, each with the sign (for points and / or surface sections within the model) or "+" (for points and / or surface sections outside the model). Such a combination results in a manufacturing layer in which all positions are assigned the same information. This has the advantage that for points or surface sections that do not lie on the surface of the model, a clear assignment is possible as to whether the points or surface sections lie (or should lie) inside or outside the model. When assigning information (e.g., in the form of a number or a sign, as explained above), a tolerance can be provided within which the information can be assigned. For example, a point or surface section can be assigned the information that the point or surface section lies on the surface of the model (e.g., this information is assigned in the form of the number "0") if the point or surface section lies on the surface of the model.The surface segment lies within a distance interval from the surface. This distance interval is a tolerance, within which information is assigned to the point or surface segment. In this implementation, information is assigned to manufacturing layers and manufacturing layers within a tolerance. This means, for example, that manufacturing layers and scanning planes that lie within a distance interval from the surface of the model are assigned the same information (the number "0"). Analogous to the embodiments explained above, intersections of manufacturing layers and scanning planes are combined, and the resulting manufacturing layer is formed. In this example, this manufacturing layer represents the surface of a component to be manufactured. For points or surface segments that lie inside or outside the model, a minimum distance (tolerance) can be defined.A tolerance distance is specified from the model surface. Information indicating whether a point or surface segment lies inside (e.g., by assigning a "-" sign) or outside (e.g., by assigning a "+" sign) is assigned to the point or surface segment if its distance from the surface exceeds the specified minimum distance. This distance (tolerance) can be the same or different for points or surface segments inside and outside the model.

[0106] It may occur that a certain surface roughness is desired as a predefined texture. In this case, it is preferred that the method be given a mask that determines in which areas, particularly on the surface, the influence of the scanning planes is deactivated.

[0107] A preferred device comprises a verification unit designed to verify the respective intersection of a manufacturing layer and / or scanning plane after determining the intersections. The verification is preferably performed to determine whether the total area of ​​the intersection in a layer falls below a predetermined limit and / or whether the areas of the intersections of the manufacturing layer and a scanning plane are disjoint. A democratic check can also be performed for each point of a manufacturing layer. Preferably, in this case, the merging unit is designed to generate layer data for a manufacturing layer essentially at the position of that manufacturing layer based on this verification.

[0108] The invention is explained in more detail below with reference to the accompanying figures and exemplary embodiments. The same components are designated with identical reference numerals in the various figures. The figures are generally not to scale. They show:

[0109] Figure 1 shows a schematic, partially sectional view of an embodiment of a device for additive manufacturing,

[0110] Figure 2 shows possible intersections of a rough-surface model with a manufacturing layer.

[0111] Figure 3 shows a model with manufacturing layers and scanning planes.

[0112] Figure 4: Objects that resulted from different unions,

[0113] Figure 5 is a block diagram for an example of a method according to the invention.

[0114] The following embodiments are described with reference to a manufacturing device 1 for the additive manufacturing of components in the form of a selective laser sintering or laser melting device, whereby it is explicitly pointed out once again that the invention is not limited to selective laser sintering or laser melting devices.

[0115] Such a manufacturing device 1 is shown schematically in Figure 1. The device has a process chamber 3 or process space 3 with a chamber wall 4, in which the manufacturing process essentially takes place. Inside the process chamber 3 is an upwardly open container 5 with a container wall 6. The upper opening of the container 5 forms the current working level 7. The area of ​​this working level 7 located within the opening of the container 5 can be used for building the object 2 and is therefore referred to as the build area 8.

[0116] Container 5 has a base plate 11 that is movable in a vertical direction V and is mounted on a support 10. This base plate 11 closes off the container 5 at the bottom, thus forming its base. The base plate 11 can be integral with the support 10, or it can be a separate plate that is attached to or simply supported by the support 10. Depending on the specific material used, such as the powder, and the manufacturing process, a build platform 12 can be attached to the base plate 11 as a base on which the object 2 is built. Alternatively, the object 2 can also be built directly on the base plate 11 itself, which then serves as the build platform.

[0117] The basic assembly of object 2 is carried out by first applying a layer of build material 13 to the build platform 12, then – as explained later – selectively solidifying the build material 13 with a laser beam 22 as an energy beam at the points that are to form parts of the object 2 to be manufactured, then lowering the base plate 11, and thus the build platform 12, with the aid of the support 10, and applying and selectively solidifying a new layer of build material 13, and so on. In Figure 1, object 2, assembled in the container on the build platform 12 below the working plane 7, is shown in an intermediate state. It already has several solidified layers, surrounded by unsolidified build material 13.Various materials can be used as building material 13, preferably powders, in particular metal powders, plastic powders, ceramic powders, sand, filled or mixed powders or pasty materials, and optionally a mixture of several materials.

[0118] Fresh build material 15 is located in a storage container 14 of the manufacturing device 1. With the aid of a coater 16 that can be moved in a horizontal direction H, the build material can be applied in the working plane 7 or within the build area 8 in the form of a thin layer.

[0119] Optionally, an additional radiant heater 17 is located in process chamber 3. This heater can be used to heat the applied build-up material 13, so that the irradiation device used for selective solidification does not have to supply too much energy. This means, for example, that a certain amount of base energy can be introduced into the build-up material 13 using the radiant heater 17, which is naturally still below the energy required for the build-up material 13 to fuse or sinter. An infrared radiator or a VCSEL radiator, for example, can be used as the radiant heater 17.

[0120] For selective hardening, the manufacturing device 1 includes an irradiation device 20, or more specifically, an exposure device 20 with a laser 21. This laser 21 generates a laser beam 22, which is deflected by a deflecting device 23 to trace the exposure paths or tracks in the layer to be selectively hardened, as defined by the exposure strategy, and to selectively introduce the energy. Furthermore, this laser beam 22 is focused onto the working plane 7 in a suitable manner by a focusing device 24. The irradiation device 20 is preferably located outside the process chamber 3, and the laser beam 22 is directed into the process chamber 3 via a coupling window 25 located in the chamber wall 4 on the upper side of the process chamber 3.

[0121] The irradiation device 20 can, for example, comprise not just one, but several lasers. Preferably, these can be gas or solid-state lasers or any other type of laser, such as laser diodes, in particular VCSELs (Vertical Cavity Surface Emitting Lasers) or VECSELs (Vertical External Cavity Surface Emitting Lasers), or an array of such lasers. Most preferably, one or more unpolarized single-mode lasers, e.g., a 3 kW fiber laser with a wavelength of 1070 nm, can be used within the scope of the invention.

[0122] A control device 30 comprising a control unit 29 serves to control the units of the manufacturing device 1, which controls the components of the irradiation device 20, namely the laser 21, the deflection device 23 and the focusing device 24, and transmits corresponding control data PS to them.

[0123] The control unit 29 also controls the radiant heating 17 by means of suitable heating control data HS, the coater 16 by means of coating control data ST and the movement of the carrier 10 by means of carrier control data TS, thus controlling the layer thickness.

[0124] The control unit 30 is connected, for example via a bus 60 or another data connection, to a terminal 40 with a display or the like. An operator can use this terminal 40 to control the control unit 30 and thus the entire laser sintering device 1, for example by transmitting process control data PS.

[0125] The control device 30 comprises a device 34 according to the invention for creating layer data S for layer-by-layer additive manufacturing of an object 2 from a geometric model M by solidifying manufacturing layers F. The device comprises a data interface 35, a definition unit 36, a determination unit 37, a target quantity unit 38 and a layer data unit 39.

[0126] The data interface 35 is used to receive model space data D, comprising at least geometric data of the model M and / or a negative mask of the model M. The definition unit 36 ​​is used to define a sampling procedure that specifies how a model space M is sampled in different sampling areas A1, A2, A3, A4. The determination unit 37 is used to create a set of areas B for each sampling area A1, A2, A3, A4, whereby the model space data D is sampled in the sampling areas A1, A2, A3, A4, and those parts of a sampling area A1, A2, A3, A4 in which the model space data D has the same predefined spatial relationship to the model M are assigned to the respective set of areas B.

[0127] The target set unit 38 is used to generate a number of target sets by combining created range sets B from different sampling ranges A1, A2, A3, A4.

[0128] The layer data unit 39 is used to create layer data S for a multitude of manufacturing layers F, wherein at least one of the manufacturing layers F is assigned a printing area based on a number of target quantities.

[0129] The data interface 35 can also be used to output the shift data S or to output process control data PS that has been obtained from this shift data.

[0130] It should also be noted again at this point that the present invention is not limited to such a manufacturing device 1. It can be applied to other methods for the generative or additive manufacturing of a three-dimensional object by layer-by-layer application and selective solidification of a build-up material, wherein an energy beam is emitted onto the build-up material to be solidified. Accordingly, the irradiation device can also be anything other than a laser, as described here; any device could be used with which energy can be selectively introduced onto or into the build-up material as wave or particle radiation. For example, instead of a laser, another light source, an electron beam, etc., could be used.

[0131] Although only a single object 2 is shown in Figure 1, it is preferred to produce several objects in parallel in the process chamber 3 or in the container 5. For this purpose, the build material is scanned layer by layer at points that correspond to the cross-sections of the objects in the respective layer by the energy beam 22.

[0132] Figure 2 shows possible intersections SM of a model M with a rough surface and a manufacturing layer F. In the left-hand illustration, the model M with its rough surface rests on the manufacturing layer F. The intersection SM is a dot pattern representing the contact points between the rough surface and the manufacturing layer F. Such an intersection SM is not desired. In the right-hand illustration, the model M with its rough surface is slightly sunken into the manufacturing layer F. The intersection SM is a solid area. Such an intersection SM is desired.

[0133] Figure 3 shows a model M with manufacturing layers F and scanning planes A1, A2, A3, A4. For clarity, only the scanning planes A1, A2, A3, A4 of the second manufacturing layer F are marked with reference symbols. The dashed scanning planes A2 and A3 are close to "their" manufacturing layer F, and the dash-dotted ones are farther away. In this example, the arrangements of the scanning planes A1, A2, A3, A4 for each manufacturing layer F are identical. The more distant scanning planes A1, A2, A3, A4 are assigned to both adjacent manufacturing layers in this example, so that the scanning planes A1 and A4 located midway between two manufacturing layers F are assigned to both manufacturing layers F.

[0134] Potential markers are shown above the topmost layer. The intersections can be represented as pixels in the layers to which values ​​are assigned. Here, the pixels of the respective layer are marked with the signs "+" and "-". assigned. However, the markers could also be represented bitwise as "0" and "1" or as black and white.

[0135] Figure 4 shows objects 2 that resulted from different combinations of the layers in Figure 3. The analysis examines which surface of the model M is intersected by a layer, and this surface is then the intersection S of the respective layer. The objects 2 consist of four layers (indicated by blocks). It should be noted that the layers are very thin in reality.

[0136] On the left is a union of the intersection areas S of the manufacturing layers F and the closer scanning planes A2 and A3 (shown as dashed lines in Figure 3). The upper part of the model M is reproduced quite well, but the outgrowth at the bottom right is missing. This is because the lower surface of this outgrowth does not extend to either the manufacturing layer F or the (here considered) closer scanning plane A3.

[0137] In the center, a union of the intersections S of the manufacturing layers F and the further scanning planes A1 and A4 is shown (represented by dashed lines in Figure 3). The lower part of the model M is reproduced quite well, but it appears as a block at the top. This is because the lower surface of this outgrowth does not reach either the manufacturing layer F or the (here considered near) scanning plane A3. On the right, a union of the intersections SM of the manufacturing layers F, the nearer scanning planes A2 and A3, and the upper far scanning plane A4 is shown; the lower far scanning plane A1 is not covered by a manufacturing layer. Here, the model M is reproduced quite well, although it should be noted that the rasterization cannot be more precise due to the given layer thickness.

[0138] Figure 5 shows a block diagram for an example of a method according to the invention for creating layer data S for a layer-by-layer additive manufacturing of an object 2 from a geometric model M by solidifying manufacturing layers F.

[0139] In step I, model space data D is provided. This includes at least geometric data of the model M and / or a negative mask of the model M.

[0140] In step II, the sampling procedure is defined, which specifies how a model space M is sampled in different sampling areas A1, A2, A3. The sampling areas are assigned to groups of manufacturing layers F.

[0141] In step III, a set of regions B is created for each sampling region A1, A2, A3. These are indicated here by hatching. For this purpose, the model space data D in the sampling regions A1, A2, A3 are sampled, and those parts of a sampling region A1, A2, A3 in which the model space data D have the same predefined spatial relationship to the model M (here "belonging to the model") are assigned to the respective set of regions B.

[0142] In step IV, target sets are generated by combining created range sets B from different sampling ranges A1, A2, A3.

[0143] These target sets yield layer data S, from which process control data can then be generated. The layer data could also be used to modify the model M.

[0144] Finally, it should be noted once again that the invention described in detail above merely represents exemplary embodiments, which can be modified in various ways by a person skilled in the art without departing from the scope of the invention. Furthermore, the use of the indefinite articles "a" or "an" does not preclude the possibility that the features in question may be present multiple times. Likewise, terms such as "unit" do not preclude the possibility that the components in question consist of several interacting sub-components, which may also be spatially distributed. The term "a number" should be interpreted as "at least one."

[0145] Reference symbol list

[0146] 1 Manufacturing device / Laser sintering device

[0147] 2 Object / Object

[0148] 3 Process room / Process chamber

[0149] 4 chamber wall

[0150] 5 containers

[0151] 6 Container wall

[0152] 7 Working level

[0153] 8 Building plot

[0154] 10 carriers

[0155] 11 Base plate

[0156] 12 building platforms

[0157] 13 Construction material (in container 5)

[0158] 14 storage containers

[0159] 15 Assembly material (in storage container 14)

[0160] 16 coaters

[0161] 17 Radiant heating

[0162] 20 Irradiation device / Exposure device

[0163] 21 lasers

[0164] 22 Laser beam / energy beam

[0165] 23 Deflection device / Scanner

[0166] 24 Focusing device

[0167] 25 coupling windows

[0168] 29 Control unit

[0169] 30 Control unit

[0170] 31 Irradiation control interface

[0171] 34 Device

[0172] 5 Data interface

[0173] 36 Unit of definition

[0174] 37 Investigation Unit

[0175] 38 Target quantity unit

[0176] 39 Shift Data Unit

[0177] 40 Terminal

[0178] 60 Bus

[0179] A1 Sampling area / sampling plane

[0180] A2 Sampling range / Sampling plane A3 Sampling range I Sampling plane

[0181] A4 scanning area / scanning plane

[0182] B Range set

[0183] D Model space data F Manufacturing layer

[0184] HS heating control data

[0185] M Model

[0186] PS Process control data

[0187] S layer data SM intersection

[0188] ST coating control data

[0189] TS T carrier tax data

[0190] V vertical direction

[0191] Z Target set

Claims

1. 32 Patent claims 1. Method for creating layer data (S) for layer-by-layer additive manufacturing of an object (2) from a geometric model (M) by solidifying manufacturing layers (F), the method comprising the steps: - Providing model space data (D) comprising at least geometric data of the model (M) and / or a negative mask of the model (M), - Defining a sampling rule that specifies how a model space (M) is sampled in different sampling ranges (A1 , A2, A3, A4), - Creating a set of regions (B) for each sampling region (A1, A2, A3, A4), whereby the model space data (D) in the sampling regions (A1, A2, A3, A4) are sampled and those parts of a sampling region (A1, A2, A3, A4) in which the model space data (D) have the same predefined spatial relationship to the model (M) are assigned to the respective set of regions (B), - Generating a number of target sets by combining created range sets (B) of different sampling ranges (A1 , A2, A3, A4), - Creating layer data (S) for a multitude of manufacturing layers (F), wherein at least one of the manufacturing layers (F) is assigned a printing area based on a number of target quantities.

2. Method according to claim 1, wherein the scanning procedure specifies that the model space (M) is scanned in different, preferably parallel, scanning planes (A1, A2, A3, A4), preferably wherein positions of, preferably parallel, manufacturing layers (F) are defined beforehand and for a plurality of these manufacturing layers (F) an individual scanning procedure or a common scanning procedure is used.

3. Method according to claim 2, wherein for a manufacturing layer (F) several scanning planes (A1 , A2, A3, A4) are provided parallel to this manufacturing layer (F), wherein at least one scanning plane (A1 , A2, A3, A4) is arranged above the position of the manufacturing layer (F) and / or at least one scanning plane (A1 , A2, A3, A4) is arranged below the position of the manufacturing layer (F), and preferably one scanning plane (A1 , A2, A3, A4) is arranged at the position of the manufacturing layer (F), preferably wherein the scanning planes (A1 , A2, A3, A4) of a manufacturing layer (F) are located between the positions of the manufacturing layers (F) adjacent to this manufacturing layer (F).

4. Method according to one of the preceding claims, wherein at least one geometric property indicates whether the relevant part of the model space (M) is within the model (M) 33 and / or wherein at least one geometric property indicates whether the relevant part of the model space (M) lies outside the model (M), preferably wherein at least one geometric property additionally indicates whether the relevant part of the model space (M) lies on the boundary of the model (M), and / or wherein at least one geometric property indicates whether the relevant part of the model space (M) lies at a distance below a specified limit value from the boundary of the model (M).

5. Method according to one of the preceding claims, wherein the model space data (D) consists of a set of image elements in the form of points, pixels or voxels or surface elements, and each area set (B) comprises those image elements which have the same spatial relationship to the model (M), and the area set (B) preferably represents a mask of the corresponding sampling area (A1 , A2, A3, A4) with the relevant image elements.

6. A method according to any of the preceding claims, wherein for each sampling area (A1, A2, A3, A4) at least one first and one second area set (B) is created, wherein each first area set (B) is based on a first spatial relationship to the model (M), and each second area set (B) is based on a second spatial relationship to the model (M) which differs from the first spatial relationship to the model (M), preferably wherein a number of first target sets are created by combining created first area sets (B) of different sampling areas (A1, A2, A3, A4), and a number of second target sets are created by combining created second area sets (B) of different sampling areas (A1, A2, A3, A4), particularly preferably wherein the layer data (S) are created based on the first target set (Z) and / or the second target set (Z).

7. Method according to one of the preceding claims, wherein a domain set (B) and / or a target set (Z) are created based on at least two different spatial relationships, preferably wherein: - a first spatial relationship for selecting elements for a range set (B) serves, - a second spatial relationship serves to select elements for a range set (B), - an intersection (Z) of both spatial relationships serves to select elements for a domain set (B), where one of the two spatial relationships serves to select elements for another domain set (B), - a target set (Z) is created from one of these domain sets (B) by summarizing them based on a second spatial relationship, - a target set (Z) is created from one of these domain sets (B) by summarizing them based on an intersection (Z) of both spatial relationships.

8. A method according to any of the preceding claims, wherein a target set (Z) is created by a weighted union of range sets (B), wherein the weighting depends on the position of the different sampling areas (A1, A2, A3, A4) of the range sets (B) and / or the size of the range sets (B), preferably wherein the range sets (B) comprise areas or points as set elements and: - it is checked whether the total area or the number of points of a created target set (Z) falls below a predetermined limit, and in the negative case the target set (Z) in question is considered an empty set, and / or - it is checked whether areas of the sets (B) that are to be combined into a target set (Z) are disjoint and, if so, whether a transition area is created in the target set (Z) between these areas that connects them, and / or - for each point or area of ​​a range set (B) a democratic check takes place and in the positive case that a plurality of corresponding points are set in the range sets (B), the point or area is transferred to the target set (Z).

9. Method according to one of the preceding claims, wherein for elements of a range set (B), in particular for pixels or voxels, a distance to the edge of the model (M) is calculated and determined by means of this distance, - whether an element is assigned to the border, and / or - the weighting given to the domain set (B) when forming a target set (Z).

10. A method according to one of the preceding claims, wherein at least the position of a lowest manufacturing layer (F) is specified and the scanning procedure specifies several scanning planes parallel to this manufacturing layer (F) as scanning areas (A1, A2, A3, A4), wherein the target set (Z) is a union of area sets (B), preferably wherein a distance A between two manufacturing layers (F) is specified and a number of scanning planes lie in a first distance range (A1, A2, A3, A4) to the position of the manufacturing layer (F), which is smaller than A / 10, and a number of scanning planes in a second distance range (A1 , A2, A3, A4) to the position of the manufacturing layer (F), which lies between A and A / 5.

11. Device (34) for creating layer data (S) for layer-by-layer additive manufacturing of an object (2) from a geometric model (M) by solidifying manufacturing layers (F), the device (34) comprising: - a data interface (35) designed for receiving model space data (D) comprising at least geometric data of the model (M) and / or a negative mask of the model (M), - a definition unit (36) designed to define a sampling rule that specifies how a model space (M) is sampled in different sampling ranges (A1 , A2, A3, A4), - a determination unit (37) designed to create a set of areas (B) for each sampling area (A1 , A2, A3, A4), wherein the model space data (D) in the sampling areas (A1 , A2, A3, A4) are sampled and those parts of a sampling area (A1 , A2, A3, A4) in which the model space data (D) have the same predefined spatial relationship to the model (M) are assigned to the respective set of areas (B), - a target set unit (38) designed to generate a number of target sets by combining created range sets (B) of different sampling ranges (A1 , A2, A3, A4), - a layer data unit (39) designed to create layer data (S) for a plurality of manufacturing layers (F), wherein at least one of the manufacturing layers (F) is assigned a printing area based on a number of target quantities.

12. Layer data (S) characterized in that they have been created using a method according to one of claims 1 to 10, preferably by means of a device (34) according to claim 11.

13. Control device (30) for a manufacturing device (1) for the additive manufacturing of an object (2) in a manufacturing process in which build material, preferably comprising a plastic powder or metal powder, is built up layer by layer in a build area (8) and selective solidification of build material takes place between the application of two layers of build material by means of irradiation of the build material with at least one energy beam (22), the control device (30) comprising a device (34) according to claim 11. 36 14. Manufacturing device (1) for the additive manufacturing of at least one object (2) in an additive manufacturing process comprising at least - a feeding device for applying layers of build material in a build area (8) into a process chamber, - an irradiation device (20) for selectively solidifying build material between the application of two layers of material by irradiation with at least one energy beam (22), and - a control device (30) according to claim 13.

15. Computer program product comprising a computer program which can be directly loaded into a storage device of a computing device, in particular a control device (30) of a manufacturing device (1) for the additive manufacturing of an object layer of an object (2), comprising program sections to execute all steps of the method according to any one of claims 1 to 10 when the computer program is executed in the computing device.

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