阅读说明：本技术 用于根据预定的几何数据制造至少一个固体层的方法 (Method for producing at least one solid layer according to predetermined geometric data ) 是由 H·玛西亚 于 2020-04-16 设计创作，主要内容包括：在用于制造固体层的方法中提供发射器组件(11)。底座(1)相对于发射器组件围绕转动轴线(2)转动定位,并且将可穿过喷嘴的材料的材料份额施加到底座上并且使其固化。离转动轴线最远的发射器(12)的中点与转动轴线具有第一径向间距,并且最靠近转动轴线布置的发射器(12)的中点与转动轴线具有第二径向间距。产生触发信号,该触发信号限定触发部位。对于各个发射器根据几何数据和/或根据当底座定位在相应的触发部位时相关的发射器相对于所述底座布置所在的位置来分别产生激活信号并且临时存储激活信号。在触发部位处这样操控发射器,使得仅如下发射器输出材料,在所述发射器中材料输出信号得到设定。在彼此相邻的触发部位之间的角度选择为,使得该角度相应于第一和第二径向线在其之间包夹的角度。第一径向线从转动轴线向着在第一发射器列和与转动轴线同心的参考圆线(25)之间的交点延伸。第二径向线从转动轴线向着在第二发射器列和参考圆线之间的交点延伸。参考圆线的半径小于第一间距的90％和第二间距的10％之和。该半径大于第一间距的10％和第二间距的90％之和。(An emitter assembly (11) is provided in a method for manufacturing a solid layer. The base (1) is rotationally positioned relative to the emitter assembly about a rotational axis (2), and a portion of material that can pass through the nozzle is applied to the base and allowed to solidify. The midpoint of the emitter (12) furthest from the axis of rotation has a first radial spacing from the axis of rotation, and the midpoint of the emitter (12) disposed closest to the axis of rotation has a second radial spacing from the axis of rotation. A trigger signal is generated, the trigger signal defining a trigger site. The activation signal is generated separately for each emitter from the geometric data and/or from the position at which the relevant emitter is arranged relative to the base when the base is positioned at the respective trigger point and temporarily stored. The emitter is actuated at the triggering point in such a way that only the emitter in which the material output signal is set outputs material. The angle between the triggering points adjacent to one another is selected such that it corresponds to the angle between which the first and second radial lines are enclosed. A first radial line extends from the axis of rotation toward an intersection between the first emitter row and a reference circle line (25) concentric with the axis of rotation. A second radial line extends from the axis of rotation toward an intersection between the second emitter column and the reference circle line. The radius of the reference circular line is less than the sum of 90% of the first pitch and 10% of the second pitch. The radius is greater than the sum of 10% of the first pitch and 90% of the second pitch.)

1. Method for producing at least one solid layer according to predetermined geometric data, which are stored in a memory (15), wherein at least one emitter assembly (11, 11A, 11B, 11C, 11D) having a plurality of emitters (12) which are spaced apart from one another and are designed as material outlet nozzles is provided for outputting material portions of a material which can pass through the nozzles onto a base (1) and/or a solidified material layer located on the base, wherein the emitter assembly (11, 11A, 11B, 11C, 11D) has a plurality of emitter rows (13A, 13B, 13C) in which the center points of the emitters (12) are respectively offset from one another in a straight line, wherein the base (1) is offset relative to the emitter assemblies (11, 11A, 11B, 11C, 11D) Is positioned in rotation about a rotational axis (2) and the material portion is applied to the base (1) and/or to a solidified material layer located thereon by means of the emitter (12) and the material portion is solidified after that, wherein a center point of the emitter (12) of the emitter assembly (11, 11A, 11B, 11C, 11D) which is furthest away from the rotational axis (2) has a first radial distance (R1) from the rotational axis (2) and a center point of the emitter (12) which is arranged closest to the rotational axis (2) has a second radial distance (R2) from the rotational axis (2), wherein a trigger signal is generated which defines a trigger point (20) for the rotational position of the emitter assembly (11, 11A, 11B, 11C, 11D) relative to the base (1), 21. 22) for each transmitter (12), wherein an activation signal is generated and temporarily stored in each case for the respective transmitter (12) as a function of the geometric data stored in the memory (15) and/or as a function of the position at which the relevant transmitter (12) is arranged relative to the base (1) when the base is positioned relative to the transmitter arrangement (11, 11A, 11B, 11C, 11D) at the respective triggering point (20, 21, 22), wherein the transmitters (12) are operated in each case at the triggering points (20, 21, 22) in such a way that only the transmitter (12) in which the previously temporarily stored activation signal was set outputs material, wherein the angle between the triggering points (20, 21, 22) adjacent to one another is selected in such a way that it corresponds to the angle (α) between which the first radial line (23) and the second radial line (24) are enclosed, wherein the first radial line (23) extends from the rotational axis (2) towards an intersection between a first emitter row (13A) and a reference circle line (25, 25A, 25B, 25C, 25D) concentric to the rotational axis (2), and the second radial line (24) extends from the rotational axis (2) towards an intersection between a second emitter row (13B) adjacent to the first emitter row (13A) in a circumferential direction of the rotational axis (2) and the reference circle line (25, 25A, 25B, 25C, 25D), wherein a radius of the reference circle line (25, 25A, 25B, 25C, 25D) is smaller than a sum of 90% of the first radial spacing (R1) and 10% of the second radial spacing (R2), and a radius of the reference circle line (25, 25A, 25B, 25C, 25D) is larger than a sum of 10% of the first radial spacing (R1) and a radius of the second radial spacing R2) The sum of 90%.

2. Method for producing at least one solid layer according to predetermined geometric data, which are stored in a memory (15), wherein a container (30) is provided, in which at least one material layer consisting of a liquid, pasty or powdery material (31) is applied to a base (1), wherein, for irradiating the material with radiation that solidifies the material, an emitter assembly having a plurality of radiation emitters (12) that are spaced apart from one another and face the material layer is provided, wherein the emitter assembly (11, 11A, 11B, 11C, 11D) has a plurality of emitter rows (13A, 13B, 13C) in which the center points of the emitters (12) are respectively offset from one another in a straight line, wherein the base (1) is displaced relative to the emitter assembly (11, 11A, 11C), 11B, 11C, 11D) is positioned in rotation about a rotation axis (2) and the radiation is directed to the material layer by means of the emitter (12) such that the material solidifies at least one irradiation site, wherein a midpoint of the emitter (12) of the emitter assembly (11, 11A, 11B, 11C, 11D) which is furthest away from the rotation axis (2) has a first radial distance (R1) from the rotation axis (2) and a midpoint of the emitter (12) which is arranged closest to the rotation axis (2) has a second radial distance (R2) from the rotation axis (2), wherein a trigger signal is generated which defines a trigger site (20, 21, 22) for the rotational position of the emitter assembly (11, 11A, 11B, 11C, 11D) relative to the base (1), wherein for each emitter (12) an activation signal is generated and temporarily stored in dependence on the geometrical data stored in the memory (15) and/or in dependence on the position at which the relevant emitter (12) is arranged relative to the base (1) when the base is positioned relative to the emitter assembly (11, 11A, 11B, 11C, 11D) at the respective triggering point (20, 21, 22), wherein the emitters (12) are each actuated at the triggering points (20, 21, 22) such that only the emitter (12) in which the previously temporarily stored activation signal was set outputs radiation, wherein the angle between the triggering points (20, 21, 22) adjacent to one another is selected such that it corresponds to the angle (a) between which the first radial line (23) and the second radial line (24) are enclosed, wherein the first radial line (23) extends from the rotational axis (2) towards an intersection between a first emitter row (13A) and a reference circle line (25, 25A, 25B, 25C, 25D) concentric to the rotational axis (2), and the second radial line (24) extends from the rotational axis (2) towards an intersection between a second emitter row (13B) adjacent to the first emitter row (13A) in a circumferential direction of the rotational axis (2) and the reference circle line (25, 25A, 25B, 25C, 25D), wherein a radius of the reference circle line (25, 25A, 25B, 25C, 25D) is smaller than a sum of 90% of the first radial spacing (R1) and 10% of the second radial spacing (R2), and a radius of the reference circle line (25, 25A, 25B, 25C, 25D) is larger than a sum of 10% of the first radial spacing (R1) and a radius of the second radial spacing R2) The sum of 90%.

3. Method according to claim 1 or 2, characterized in that the radius of the reference circle line (25, 25A, 25B, 25C, 25D) is smaller than the sum of 80% of the first radial spacing (R1) and 20% of the second radial spacing (R2), and the radius of the reference circle line (25, 25A, 25B, 25C, 25D) is larger than the sum of 20% of the first radial spacing (R1) and 80% of the second radial spacing (R2).

4. Method according to claim 1 or 2, characterized in that the radius of the reference circle line (25, 25A, 25B, 25C, 25D) is smaller than the sum of 70% of the first radial spacing (R1) and 30% of the second radial spacing (R2), and the radius of the reference circle line (25, 25A, 25B, 25C, 25D) is larger than the sum of 30% of the first radial spacing (R1) and 70% of the second radial spacing (R2).

5. Method according to claim 1 or 2, characterized in that the radius of the reference circle line (25, 25A, 25B, 25C, 25D) is smaller than the sum of 60% of the first radial spacing (R1) and 40% of the second radial spacing (R2), and the radius of the reference circle line (25, 25A, 25B, 25C, 25D) is larger than the sum of 40% of the first radial spacing (R1) and 60% of the second radial spacing (R2).

6. Method according to one of claims 1 to 5, characterized in that an emitter assembly is provided, which has at least two emitter columns arranged parallel to one another, in which the middle points of the emitters belonging to the associated emitter column are respectively offset from one another in a straight line.

7. Method according to claim 6, characterized in that each activation point (20, 21, 22) is associated with a respective transmitter row (13A, 13B, 13C), and in that the activation signals provided for the individual triggering points (20, 21, 22) are generated in each case only for the transmitters (12) of the transmitter array (13A, 13B, 13C) associated with the associated triggering point (20, 21, 22) on the basis of the geometric data stored in the memory (15) and on the basis of the position at which the associated transmitter (12) is arranged, and setting an activation signal for emitters (12) not arranged in the emitter column (13A, 13B, 13C) to, such that the emitters (12) are not activated when the emitter assembly (11, 11A, 11B, 11C, 11D) is positioned relative to the base at the triggering location (20, 21, 22).

8. The method according to claim 6 or 7, characterized in that the emitter columns (13A, 13B, 13C) of the emitter assemblies (11, 11A, 11B, 11C, 11D) are arranged symmetrically to a radial plane formed by the rotation axis (2) and a normal to the rotation axis (2) such that the emitter columns (13A, 13B, 13C) extend parallel to the radial plane.

9. Method according to one of claims 1 to 8, characterized in that for printing a printing ring (27A, 27B, 27C, 27D) arranged concentrically to the axis of rotation (2) and delimited by an inner circular track and an outer circular track, respectively, at least one first emitter assembly and at least one second emitter assembly (11A, 11B, 11C, 11D) are provided, which emitter assemblies (11A, 11B, 11C, 11D) are positioned relative to the axis of rotation (2) such that the arithmetic mean of the inner circular track and the outer circular track of the first emitter assembly (11A) differs from the arithmetic mean of the inner circular track and the outer circular track of the second emitter assembly (11B), a reference circle line (25A) with a first radius is used for generating a trigger signal for the first emitter assembly (11A), and using a reference circle line (25B) having a second radius different from the first radius for generating the trigger signal of the second emitter assembly (11B), and the first radius is selected according to the first and second radial spacings of the first emitter assembly (11A) according to any one of claims 1 to 5, and the second radius is selected according to the first and second radial spacings of the second emitter assembly (11B) according to any one of claims 1 to 5.

10. Method according to any of claims 1 to 9, characterized in that at least two emitter assemblies (11A, 11B, 11C, 11D) are provided, which are offset from each other with a certain angle of rotation with respect to the axis of rotation (2), and that the emitters (12) of the respective emitter assemblies (11A, 11B, 11C, 11D) are controlled separately according to at least one of claims 1 to 8.

11. The method according to one of claims 1 to 10, characterized in that the center points of the emitters (12) adjacent to one another within the emitter columns (13A, 13B, 13C) are arranged at a constant first grid pitch, in that the emitter columns (13A, 13B, 13C) adjacent to one another are respectively offset from one another by a constant second grid pitch, and in that the first grid pitch differs from the second grid pitch by less than 20 percent, in particular by less than 10 percent and in particular corresponds to the second grid pitch.

12. Method according to one of claims 1 or 3 to 11, characterized in that for producing a three-dimensional shaped object (17A, 17B, 17C, 17D) a plurality of material layers of the material that can be passed through the nozzle are applied one on top of the other, wherein the distance between the emitter assembly (11, 11A, 11B, 11C, 11D) and the base (1) is increased in each case in the thickness of the last applied material layer one after the other, and each material layer is cured after its application and then a further material layer is applied to it.

13. Method according to one of claims 2 to 11, characterized in that, for producing a three-dimensional shaped object (17A, 17B, 17C, 17D), a plurality of material layers of liquid, paste-like or powder-like material are solidified one on top of the other by irradiation with the emitter assembly (11, 11A, 11B, 11C, 11D).

Technical Field

The invention relates to a method for producing at least one solid layer according to predetermined geometric data, which are stored in a memory.

Background

In the method known from US2004/0265413a1, the geometric data stored in the memory as rectangular coordinate printing points are converted into polar coordinates by means of a coordinate conversion device. In the method, a 3D printer is provided, which has two emitter assemblies, each having a plurality of emitters configured as nozzles, which are spaced apart from one another, for discharging material portions of the liquid material onto a base. The base is designed in a disk-shaped manner and can be positioned in a rotating manner about a rotation axis relative to the transmitter assembly by means of a drive. A rotational position signal for the relative position between the transmitter element and the base is generated by means of a decoder.

Each emitter assembly has a plurality of commercially available print heads which are incrementally movable radially to the axis of rotation on a print head carrier arranged at the glide guide. Irregularities that may be caused by an inoperative print head, a stoppage or a wrongly positioned emitter during printing should therefore be corrected by changing the position of the emitter assembly layer by layer. The errors due to the stoppage of one emitter are thus arranged at different locations and averaged for each printed layer. Furthermore, the emitter assembly may be arranged by means of the print head carrier between a printing position, in which the emitter is arranged above the chassis, a diagnostic position, in which the emitter is positioned at a diagnostic device located beside the chassis, and a service maintenance position, in which the emitter is positioned beside the chassis and beside the service maintenance position. In the service maintenance position, the transmitter may be cleaned or replaced.

How accurately the emitters of the emitter assemblies are arranged and how the emitters of the emitter assemblies are manipulated during printing is not disclosed in detail in the publication.

The previously known methods have the following disadvantages: positioning inaccuracies can occur when the print head carrier is moved radially. Furthermore, the movement of the print head carrier and the large number of print heads is costly.

From practice, 3D printers are also known, which have a support on which a substantially rectangular base is arranged, which extends in a horizontal plane, for receiving a profiled object to be produced by layer-by-layer material application. The printer is used for printing the molding object in a Cartesian coordinate matrix. The geometric data associated with the printing points, which are in a cartesian coordinate matrix, are provided for the molded object.

Via the base, a print head is arranged at the support, which print head has a nozzle assembly for outputting a material portion of the flowable material onto the base, which nozzle assembly is also referred to below as an emitter assembly. The emitter assembly has a plurality of emitters configured as nozzles, which are arranged in a matrix-like manner in an oblique rectilinear coordinate system with emitter columns offset parallel to one another and emitter rows offset parallel to one another and extending transversely to the emitter columns. Emitter columns adjacent to one another are each offset from one another in the direction of extent of the emitter columns, wherein the offset is smaller than the offset which the emitters in an emitter column have. The emitter columns extend parallel to the two short edges (X-axis) of the rectangular base. The emitters are arranged such that each emitter of the emitter assembly is at another X position of the cartesian coordinate matrix in a direction extending parallel to the two short edges of the rectangular base. In this case, each X position of the coordinate matrix is associated with exactly one transmitter of the transmitter assembly.

The emitter assembly can be moved parallel to the longitudinal extension direction of the base in the Y direction by means of a first positioning device arranged at the support and can be moved back and forth between two short edges that are remote from one another. Since the printing dots directly adjacent to one another, which lie on a line extending parallel to the two short edges of the rectangular base in the X-axis direction, are printed with nozzles arranged in different emitter columns of the emitter assembly, the print head is positioned at different X-positions when printing the mutually adjacent printing dots of the line in such a way that the offset of the different emitter columns in the X-axis direction is compensated. The printing dots arranged directly next to one another in the X direction can thus be printed on the base so closely offset from one another that they overlap locally. The emitters of the emitter assembly are nevertheless spatially separated from each other and spaced apart from each other to such an extent that channels and/or electrical conductor tracks connecting the emitters with a reservoir for material that can pass through the nozzle can be arranged between the emitters.

The emitter of the emitter assembly is movable relative to the base with a reservoir for material that is passable through the nozzle. Adjacent to the print head, a curing device is arranged, which has an ultraviolet light source for crosslinking or curing the material layer applied by means of the emitter assembly. The curing device is movable with the printhead relative to the base.

The previously known 3D printer furthermore has a second positioning device, by means of which the base can be moved towards the print head and away from the print head, normal to the plane in which the base extends, i.e. can be positioned in height.

To manufacture the molded object, a print head is positioned over a base adjacent a first edge of the base at a predetermined spacing. From a data memory, in which the geometric data for the profiled object to be produced are stored, data for the geometry of the first material layer are loaded into a fast print buffer. After which the print head is moved continuously by means of the first positioning device towards the opposite second edge of the base. At the same time, the individual emitters of the emitter arrangement are actuated in each case to output a material portion onto the base at the point at which the first material layer of the molded object is to be formed on the base. The individual emitters are operated according to the current position of the print head and according to the data present in the print buffer. The flowable material thus applied to the base is cured by irradiation with ultraviolet light, which is generated by means of a curing device.

When the print head comes to the second edge of the bed, the horizontal feed movement of the print head is stopped and geometrical data for a further material layer to be applied onto the previously produced material layer is loaded from the data storage into the print buffer. Furthermore, the base is lowered by means of the second positioning means by a measure corresponding to the thickness of the previously produced layer of material in order to apply a further layer of material onto said layer of material. The print head is now continuously moved towards the first edge of the base by means of the first positioning means. At the same time, by corresponding actuation of the emitters, drops of material are each delivered to the finished material layer at the point at which the further material layer is to be formed. The flowable polymer material thus applied to the base is in turn cured by irradiation with ultraviolet light, which is generated by means of a curing device

The above-described method steps are repeated in a corresponding manner until all material layers of the object to be shaped are completed.

The method has the following disadvantages: time is required for stopping and accelerating the printhead module together with the accessories at the edge of the chassis, which cannot be used for printing. Said stopping and acceleration may account for up to 50% of the total printing time with small to medium printing areas and may therefore significantly reduce the productivity of the method. Furthermore, the heavy print head and the relatively large and heavy components connected thereto, such as the reservoir together with the flowable material supply located therein, the cable drag which is subject to wear and tear and the curing device, must be stopped after each completion of one material layer and accelerated in the opposite direction if further material layers are to be applied. The mechanical mechanisms of the positioning device are subjected to loads by the acceleration forces occurring in this case, which leads to corresponding wear at the bearings and guide positioning devices and thus adversely affects the accuracy of the printing machine.

Disclosure of Invention

The object is therefore to specify a method of the type mentioned at the outset, which achieves that at least one solid layer is produced in a simple manner by means of an emitter assembly in which the emitters are arranged in an oblique linear coordinate system, corresponding to the geometric data stored in the memory. In this case, large distortions due to a polar coordinate system for printing, which is different from the emitter assembly coordinate system, are to be avoided, so that an acceptable printed image is achieved despite the use of emitter assemblies with emitters arranged in a diagonal coordinate system.

This object is achieved by the features of claim 1. In a method of the type mentioned at the outset, it is provided that at least one emitter assembly is provided for the purpose of discharging a material portion of the material that can pass through the nozzle onto the base and/or onto the solidified material layer located on the base, said emitter assembly having a plurality of emitters spaced apart from one another and embodied as material discharge nozzles, the emitter assembly having a plurality of emitter rows in which the centers of the emitters are respectively offset from one another in a straight line, wherein the base is rotationally positioned relative to the emitter assembly about an axis of rotation, and the material portion is applied to the base and/or onto the solidified material layer located on the base by means of the emitters and is thereafter solidified, wherein the center of the emitter assembly that is furthest from the axis of rotation has a first radial distance from the axis of rotation, and the middle point of the transmitter arranged closest to the axis of rotation has a second radial distance from the axis of rotation, wherein a trigger signal is generated which defines a trigger point for the rotational position of the transmitter arrangement relative to the base, wherein for each transmitter an activation signal is generated and temporarily stored in dependence on the geometry data stored in the memory and/or on the position of the relevant transmitter arranged relative to the base when the base is positioned at the respective trigger point relative to the transmitter arrangement, wherein at the trigger point the transmitters are each operated such that only the transmitter output material in which the previously temporarily stored activation signal was set, the angle between the trigger points adjacent to one another being selected such that it corresponds to the angle between which the first radial line and the second radial line are enclosed, a first radial line extends from the rotational axis toward an intersection between the first emitter row and a reference circle line concentric with the rotational axis, and a second radial line extends from the rotational axis toward an intersection between a second emitter row adjacent to the first emitter row in a circumferential direction of the rotational axis and the reference circle line, a radius of the reference circle line is less than a sum of 90% of the first radial spacing and 10% of the second radial spacing, and a radius of the reference circle line is greater than a sum of 10% of the first radial spacing and 90% of the second radial spacing. The term material that can be passed through the nozzle is understood to mean a liquid, pasty or powdery medium that can be applied to the base through the nozzle, in particular by the action of pressure applied to the medium.

The above object is also achieved by the features of claim 2. In a method of the type mentioned at the outset, provision is made for a container in which at least one material layer composed of a liquid, pasty or powdery material is applied to a base, wherein, for irradiating the material with radiation that solidifies the material, an emitter assembly is provided which has a plurality of radiation emitters spaced apart from one another and facing the material layer, wherein the emitter assembly has a plurality of emitter rows in which the midpoints of the emitters are respectively offset from one another in a straight line, wherein the base is rotationally positioned relative to the emitter assembly about an axis of rotation and the radiation is directed by means of the emitters at the material layer in such a way that the material solidifies at least one irradiation site, wherein the midpoint of the emitter assembly furthest from the axis of rotation has a first radial spacing from the axis of rotation and the midpoint of the emitter arranged closest to the axis of rotation has a second radial spacing from the axis of rotation, wherein a trigger signal is generated which defines a trigger point for the rotational position of the emitter assembly relative to the base, wherein for each emitter an activation signal is generated and temporarily stored in dependence on the geometrical data stored in the memory and/or in dependence on the position at which the relevant emitter is arranged relative to the base when the base is positioned at the respective trigger point relative to the emitter assembly, wherein at the trigger point the emitters are each operated such that only the emitter outputting radiation in which the previously temporarily stored activation signal was set, the angle between the trigger points adjacent to one another being selected such that it corresponds to the angle between which a first radial line and a second radial line are enclosed, the first radial line extending from the rotational axis towards the intersection between the first emitter row and a reference circle line concentric to the rotational axis, and a second radial line extends from the rotation axis to an intersection between a second emitter row adjacent to the first emitter row in a circumferential direction along the rotation axis and a reference circular line, a radius of the reference circular line being less than a sum of 90% of the first radial pitch and 10% of the second radial pitch, and a radius of the reference circular line being greater than a sum of 10% of the first radial pitch and 90% of the second radial pitch. The invention can therefore also be applied in a method similar to the stereolithography method. The difference is that the laser beam or the LCD/LED projector of the stereolithography method is replaced by an emitter assembly according to claim 1 or 2.

The geometric data can be associated with printing dots arranged in a cartesian matrix having rows and columns, in which the printing dots are offset from one another.

Preferably, the geometric data are associated with printing dots arranged in a polar matrix, which have rows extending radially with respect to the axis of rotation, in which the plurality of printing dots are each offset from one another. Thus, a high-quality printed image is realized. The rows with the printed dots are preferably offset from each other in the circumferential direction of the axis of rotation by an angle corresponding to the angle between which the first radial line and the second radial line are sandwiched.

The geometry data is preferably stored as a bitmap and may have an activation value for each printed dot. In the simplest case, this activation value can have two states, for example a logical value "1" when the solid layer is supposed to be at the printing point and a logical value "0" when the solid layer is not supposed to be at the printing point. The activation value may also comprise more than two states if different amounts of material or radiation energy should be output to the base for each printed dot. The geometry data may also have coordinates for print dot locations, if desired. It is also conceivable to provide the coordinates only for the print points at which the solid layer should be present. In this case, additional activation values can be dispensed with.

Advantageously, in the method according to the invention, the distortions arising from the deviation of the polar coordinate system used for printing from the cartesian coordinate system in which the emitters of the emitter assembly are arranged are distributed relatively uniformly over the emitters. The maximum positional deviation occurring during printing between the material discharge point (at which the material that can pass through the nozzle is applied to the base or to the solidified material layer located on the base (claim 1)) or the irradiation point (claim 2) and the associated printing spot position (for which the geometric data are stored in the memory) is thus smaller than in the corresponding method in which the radius of the reference circle line lies outside the region specified in claim 1. In this way, an acceptable printed image is achieved in the method according to the invention despite the use of a cost-effective print head with emitters arranged in a cartesian coordinate system.

In a preferred embodiment of the invention, the radius of the reference circle line is smaller than the sum of 80% of the first radial distance and 20% of the second radial distance, and the radius of the reference circle line is larger than the sum of 20% of the first radial distance and 80% of the second radial distance. The maximum distortion or positional deviation between the location at which the material is applied to the base or to the solidified material layer located on the base and the geometric data can thereby be further reduced.

A further reduction of the maximum distortion occurring as a result of the different coordinate systems (diagonal or polar coordinate system) is achieved in an advantageous embodiment of the invention in that the radius of the reference circle line is smaller than the sum of 70% of the first radial distance and 30% of the second radial distance, and the radius of the reference circle line is larger than the sum of 30% of the first radial distance and 70% of the second radial distance.

In one embodiment of the invention, it is provided that the radius of the reference circle line is smaller than the sum of 60% of the first radial distance and 40% of the second radial distance, and the radius of the reference circle line is larger than the sum of 40% of the diameter of the outer circular track and 60% of the diameter of the inner circular track. It is particularly advantageous if the radius of the reference circle line is smaller than the sum of 55% of the first radial spacing and 45% of the second radial spacing, and the radius of the reference circle line is larger than the sum of 45% of the outer circular track and 55% of the diameter of the inner circular track. Thereby, the maximum distortion at the time of printing can be further reduced.

In an advantageous embodiment of the invention, each activation point is assigned in each case one transmitter row, wherein the transmitters of the transmitter rows assigned in each case only to the associated activation point generate an activation signal which is provided for the respective activation point as a function of the geometric data stored in the memory and as a function of the position at which the associated transmitter is arranged, and the activation signals for the transmitters which are not arranged in the transmitter rows are set such that these transmitters are not activated when the transmitter arrangement is positioned at the activation point relative to the base. The geometric data are therefore taken into account only in one single transmitter column at each triggering point in the generation of the material output signal, while the activation signals of the remaining one transmitter column (if the transmitter assembly has two transmitter columns) or of the remaining transmitter columns (if the transmitter assembly has more than two transmitter columns) are deactivated. The method can be carried out in a simple manner, since the geometry data can be transferred directly from the memory into the print buffer for the activation signal of the (active) emitter column associated with the trigger bit if the spacing of the center points of the emitters located in the emitter column corresponds to the corresponding spacing of the printing dots. The active transmitter rows are each cyclically shifted from trigger point to trigger point. Thus, for example, in a transmitter assembly having four transmitter columns, a first transmitter column may be activated at a first trigger location, a second transmitter column may be activated at a second trigger location, a third transmitter column may be activated at a third trigger location, a fourth transmitter column may be activated at a fourth trigger location, a first transmitter column may be activated at a fifth trigger location, a second transmitter column may be activated at a sixth trigger location, and so on. The method according to claim 7 is particularly suitable for emitter assemblies in which the spacing between the first emitter column and the last emitter column and thus the width of the emitter assembly is small compared to the diameter of the reference circle line.

Expediently, the emitter columns of the emitter assemblies are arranged symmetrically to a radial plane formed by the axis of rotation and the normal to the axis of rotation, such that the emitter columns extend parallel to the radial plane. If the transmitter assembly has an odd number of transmitter rows, the transmitter rows are preferably arranged such that the central transmitter row or a linear extension thereof extends through the axis of rotation. If the printhead assembly has an even number of emitter columns, the axis of rotation is preferably arranged centrally between the two innermost emitter columns or linear extensions thereof.

In one embodiment of the invention, for printing a printing ring which is arranged concentrically with respect to the axis of rotation and is delimited by an inner circular track and an outer circular track, respectively, at least one first emitter assembly and at least one second emitter assembly are provided, which are positioned with respect to the axis of rotation such that the arithmetic mean of the inner circular track and the outer circular track of the first emitter assembly differs from the arithmetic mean of the inner circular track and the outer circular track of the second emitter assembly, a reference circle line having a first radius is used for generating the trigger signal for the first emitter assembly, and a reference circle line having a second radius which differs from the first radius is used for generating the trigger signal for the second emitter assembly, and the first radius is selected according to any of claims 1 to 5 on the basis of the first and second radial spacing of the first emitter assembly, and the second radius is selected in accordance with the first and second radial spacings of the second emitter assembly in accordance with any one of claims 1 to 5. In this case, the reference circle line of each emitter assembly is advantageously arranged in each case at a distance from the inner and outer edge of the printing ring in the printing ring associated with the emitter assembly. Here, the maximum distortion occurring at the time of printing can be further reduced. Preferably, the printing rings arranged adjacent to one another abut against one another or slightly overlap one another in such a way that a seamless printing of the base or of the solidified material layer located on the base is effected in the radial direction.

In a preferred embodiment of the invention, at least two emitter assemblies are provided, which are offset from one another by a rotational angle with respect to the rotational axis, wherein the emitters of the individual emitter assemblies are controlled for the respective application of material portions according to at least one of claims 1 to 8. This enables faster material application and/or higher print resolution.

In an advantageous embodiment of the invention, the center points of the emitters adjacent to one another within an emitter column are arranged at a constant first grid distance from one another, the emitter columns adjacent to one another are each offset from one another by a constant second grid distance, and the first grid distance differs from the second grid distance by less than 20 percent, in particular by less than 10 percent, and in particular corresponds to the second grid distance. This can further reduce distortion at the time of printing.

Three-dimensional shaped objects can be produced by the method according to the invention. For this purpose, in the method of applying the material by means of a nozzle, a plurality of material layers of the material which can pass through the nozzle are applied one on top of the other. After each application of one material layer, the material layers are cured separately before applying further material layers. If the material is a crosslinkable polymeric material, curing of the material can be achieved, for example, by irradiation with UV light of a suitable wavelength. The spacing between the emitter element and the base is increased layer by the thickness of the last applied material layer. The method according to claim 2, wherein a plurality of material layers of liquid, paste or powder material are cured in a superimposed manner by irradiation with the emitter assembly over the entire surface and/or in regions in order to produce a three-dimensional shaped object.

Drawings

Embodiments of the invention are explained in detail below with the aid of the figures. In the drawings:

fig. 1 shows a device for producing three-dimensional shaped objects by layer-by-layer material application, having a base, which is designed as a carousel and to which a number of material layers for the shaped object are applied;

FIG. 2 shows a view similar to FIG. 1 after additional layers of material have been applied and the base lowered relative to FIG. 1;

fig. 3 shows a partial top view of a base and an emitter assembly arranged above the base, with emitters (nozzles) arranged in a cartesian coordinate system in a plurality of columns for outputting material fractions of a material that can pass through the nozzles onto the base, wherein the positions of the emitters are schematically marked by circles;

FIG. 4 shows a graphical illustration of a Cartesian print dot matrix;

FIG. 5 illustrates activation data for a first trigger site;

FIG. 6 shows a view similar to FIG. 3, wherein the base is at a first trigger location where the first emitter row outputs material portions onto the base to create interrupted lines, wherein the material portions are hatched;

FIG. 7 shows activation data for a second trigger site;

FIG. 8 shows a view similar to FIG. 3, wherein the base is located at a second triggering position at which the second emitter column outputs a further material portion onto the base so as to create an interrupted line;

FIG. 9 shows activation data for a third trigger site;

FIG. 10 shows a view similar to FIG. 3, wherein the base is located at a third triggering position at which a third emitter column outputs a material portion onto the base;

fig. 11A shows the material portions applied to the base along the interrupted line according to the embodiment of the invention shown in fig. 5 to 10, wherein the material portions are marked by full circles and the portions in the area of the interruption of the line where no material is applied are marked by dashed circles;

FIG. 11B shows a view similar to FIG. 11A, but with material portions not applied to the base in accordance with the present invention;

FIG. 12 shows a partial top view of a base and emitter assemblies disposed thereon, wherein the trigger locations at which the emitter columns output material onto the base when printing the lines shown in FIG. 11B that are not made in accordance with the present invention are marked by arrows at the edges of the upper portion of the figure;

fig. 13 and 14 show a partial top view of a base of a device for layer-by-layer production of three-dimensional molded objects, the base having a plurality of emitter assemblies, which are associated with different printing rings;

FIGS. 15 and 16 show views of the emitters of different print heads;

fig. 17 shows an apparatus for producing a three-dimensional shaped object from a stereolithography template, wherein the apparatus has a container in which a rotatable base and a material that can be cured by irradiation with electromagnetic radiation are arranged;

FIG. 18 shows a longitudinal section through the axis of rotation of the apparatus shown in FIG. 17; and

fig. 19 shows a view similar to fig. 18 after the further material layers have cured and the container has been lowered relative to fig. 18.

Detailed Description

In a method for the layer-by-layer application of a material that can pass through a nozzle onto a base 1 arranged in a horizontal plane, a circular ring-shaped rotary table having the base 1 is provided, which is mounted rotatably about a vertical axis of rotation 2 on a stationary holding device 3. The holding device 3 has a mounting surface on its underside, by means of which it can stand, for example, on a table or on the bottom of a space.

The base 1 is in driving connection with a first positioning device which has a first drive motor 4 by means of which the base 1 can be driven in rotation in the direction of the arrow 5 and can be positioned in accordance with a desired value signal for the rotational position provided by the operating device 6. For this purpose, the first drive motor 4 is connected to a first position controller integrated into the control device 6, which has a decoder 7 for detecting a rotational position signal for the base 1. By means of the first positioning device, the base 1 can be rotated continuously and without stopping about the axis of rotation 2 relative to the holding device 3 over almost any angle of more than 360 °.

The base 1 is also in driving connection with a second positioning device having a second drive motor 8, by means of which the base 1 is movable up and down in the direction of the double arrow 9 relative to the holding device 3 and can be positioned in accordance with the height position setpoint signal provided by the control device 6 (fig. 1 and 2). The positioning can be performed stepwise or continuously. For this purpose, the second drive motor 8 is connected to a second position controller integrated into the control device 6, which has a position sensor 10 for detecting the height position of the base 1.

In order to carry out the method, furthermore, an emitter assembly 11 is provided, which is designed as a commercially available printing head having a plurality of emitters 12 provided with controllable valves or pumps and designed as nozzles, from which material portions (for example droplets) of curable material that can pass through the nozzles can be output in each case. Instead of a print head as is customary in the market, other emitter matrices with fixed emitters can also be used. The material may be, for example, a photo-and/or electromagnetic and/or chemically crosslinkable polymer, which is stored in a reservoir, not shown in detail in the figures, which is connected to the emitter 12 via a line.

The emitters 12 are arranged on the base 1 in a plane extending parallel to the plane of the base 1, spaced apart from this plane, and are positioned relative to one another in a cartesian coordinate system in a plurality of emitter columns 13A, 13B, 13C arranged parallel to one another and emitter rows extending transversely thereto. In the emitter rows 13A, 13B, 13C, the center points of the respective emitters 12 or the plane centers of gravity of the nozzle openings of the respective emitters are shifted at a constant pitch from each other along the straight lines 14A, 14B, 14C.

The transmitter assemblies 11 are connected to a print buffer 15, in which the activation signal can be temporarily stored for each transmitter of the transmitter assemblies 11. The activation signal may, for example, have a logical value "1" or a logical value "0".

Furthermore, the transmitter assembly 11 has a trigger input to which a trigger signal can be applied. In the case of each trigger received at the trigger input, all emitters 12 of the emitter arrangement 11 for which a value "1" is respectively stored in the print buffer output a material portion. The emitters 12 for which the value "0" is stored in the print buffer are not manipulated upon receipt of the trigger, i.e. these emitters 12 do not output a material share.

For curing or for crosslinking the material layer applied to the base 1, the material layer located on the base and/or the layer stack having a plurality of material layers applied by means of the emitter assembly 11 located on the base 1, a UV light source 16 is provided, which is positioned at the base 1 such that it faces the base 1 with its radiation side.

In the exemplary embodiment according to fig. 3, 6, 8 and 10, the emitter assembly 11 has three emitter columns 13A, 13B, 13C which are arranged at a constant distance from one another and extend parallel to one another. A linear extension of the line 14B connecting the middle points of the emitters 12 of the middle emitter row 13B to one another extends through the axis of rotation 2. The linear extensions of the lines 14A, 14C connecting the center points of the emitters 12 of the two further emitter rows 13A, 13C to one another are spaced apart from the axis of rotation 2 by a measure by which the lines 14A, 14B or 14B, 14C are offset from one another perpendicular to their direction of extension.

In fig. 3, the transmitter assembly 11 is shown enlarged. The spacing a between the line 14A interconnecting the midpoints of the emitters 12 of the first emitter column 13A and the line 14C interconnecting the midpoints of the emitters 12 of the last emitter column 13C may be approximately between 20 μm and 100 μm.

By means of the device having the base 1, the emitter assembly 2, the control device 6 and the UV light source 16, three-dimensional shaped objects 17A, 17B, 17C, 17D can be produced on the base 1 by layer-by-layer application and curing of a plurality of material layers of material that can be passed through a nozzle.

The control device 6 is connected to a higher-level computer 18, for example a PC, which has a memory 19 in which geometric data are stored as printing points for the individual material layers, in which the material layers of the molded object 17A, 17B, 17C, 17D are produced corresponding to the printing points. The printing dots are arranged in a polar matrix having rows extending radially to the axis of rotation, in which rows a plurality of printing dots are respectively offset from one another. The print data or the geometry data can be provided, for example, by means of CAD software which can be run on the computer 18. Software that generates the geometric data for the individual layers of the molded object 2A, 2B, 2C, 2D can also be executed on the computer 18. To load the print data generated by means of the geometry data into the print buffer 14, the computer 18 is connected to the control device 6.

As can be seen in fig. 3, the midpoint of the emitter 12 of the emitter assembly 11 which is furthest from the axis of rotation 2 has a first radial spacing R1 from the axis of rotation 2, and the midpoint of the emitter 12 which is arranged closest to the axis of rotation 2 has a second radial spacing R2 from the axis of rotation 2. The midpoint of the emitter 12 furthest from the axis of rotation 2 lies on a circular line concentric with the axis of rotation 2 having a radius R1. The midpoint of the emitter 12 arranged closest to the rotation axis 2 lies on a circular line concentric with the rotation axis 2 having a radius R2.

The process flow of the method is explained below with the aid of fig. 3 and 5 to 10. The base is rotated about the axis of rotation 2 in the direction of arrow 5 and a trigger signal is generated defining a trigger location for the rotational position of the emitter assembly 11 relative to the base 1. The activation points adjacent to one another in the circumferential direction are offset from one another by a constant angle α about the axis of rotation 2. The angle alpha corresponds to the angle between which the first radial line 23 and the second radial line 24 are sandwiched. A first radial line 23 extends from the axis of rotation 2 towards the intersection of a line 14A, in which the middle points of the emitters 12 of the first emitter row 13A are located, and a reference circle line 25 concentric with the axis of rotation 2, the radius B of which corresponds to the arithmetic mean of the first radial spacing R1 and the second radial spacing R2. A second radial line 24 extends from the axis of rotation 2 towards the intersection of the line 14B, where the mid-points of the emitters 12 of the second emitter column 13B are located, and a reference circle line 25. The first triggering point is marked in fig. 6 by the arrow 20, the second triggering point is marked in fig. 8 by the arrow 21, and the third triggering point is marked in fig. 10 by the arrow 22.

In the memory 19, print data or geometry data for a material line of a straight line to be printed is stored, which has an interruption in the longitudinal direction approximately in the center. The print data or geometry data are associated with the print points, which are illustrated graphically in fig. 4. It is evident that the printing dots are arranged in a cartesian matrix having rows 33 offset parallel to one another, in which a plurality of printing dots are offset in each case at a constant distance from one another. The printed dots that should be solid layers are shown in fig. 4 by full or solid circles, and the printed dots that should not be solid layers are shown as circular lines. Before printing each print dot, the geometric data is first converted into a polar matrix in which the print dots are offset from one another in rows extending radially with respect to the axis of rotation 2. The mutually adjacent rows of the pole matrix are offset from one another by the angular spacing of the triggering points 21, 22, 23, respectively.

Before the base 1 reaches the first triggering position, the first activation signal is stored in the print buffer 15 for each emitter 12 of the emitter assembly 11. The first activation signal is determined for each emitter 12 of the first emitter row 13A of the emitter assemblies 11 by means of the control device 6 and temporarily stored in the print buffer 15 as a function of the geometry data stored in the memory 19 and as a function of the position at which the relevant emitter 12 is arranged relative to the base 1 when the base 1 is positioned at the first triggering point. When the relevant emitter 12 should output material onto the base 1, a logical value "1" is stored in the print buffer for the emitter 12, otherwise a value "0" is stored. The activation signals of the transmitters 12 of the second and third transmitter columns 13B, 13C are set to a logical value "0". The logical values are stored in the print buffers 15 (fig. 5), respectively. Once the base 1 is positioned at the first activation site, marked by arrow 20, the emitter assembly 11 is activated. Upon receipt of a trigger, all emitters 12 for which a value "1" is stored in the print buffer output a respective material portion onto the rotating base 1. The material portions are shown in fig. 6 by hatching. The emitter for which the value "0" is stored in the print buffer does not output material.

Before the base 1 reaches the second triggering position marked by the arrow 21 (fig. 8), a second activation signal is stored in the print buffer 15 in a further step. The second activation signal is determined for each emitter 12 of the second emitter column 13B by means of the control device 6 and temporarily stored in the print buffer 15 as a function of the geometric data stored in the memory 19 and as a function of the position at which the relevant emitter 12 is arranged relative to the base 1 when the base 1 is positioned at the second triggering point. The activation signals of the transmitters 12 of the first and third transmitter columns 13A, 13C are set to a logical value "0". The logical values are stored in the print buffers 15 (fig. 7), respectively. Once the base 1 is positioned at the second triggering position, the emitter assemblies 11 are triggered, i.e. all emitters 12 for which a value "1" is stored in the print buffer emit.

Before the base 1 reaches the third triggering position marked by the arrow 22 (fig. 10), a third activation signal is stored in a further step in the print buffer 15. The third activation signal is determined for each emitter 12 of the third emitter column 13C by means of the control device 6 and temporarily stored in the print buffer 15 as a function of the geometric data stored in the memory 19 and as a function of the position at which the relevant emitter 12 is arranged relative to the base 1 when the base 1 is positioned at the third triggering position. The activation signals of the transmitters 12 of the first and second transmitter columns 13A, 13B are set to a logical value "0". The logical values are stored in the print buffers 15, respectively (fig. 9). Once the base 1 is positioned at the third triggering position, the emitter assemblies 11 are re-triggered, i.e. all emitters 12 for which a value "1" is stored in the print buffer emit.

The lines of the interrupt generated in the above-described embodiment are shown in fig. 11A. The full black circle marks the location where the material portion is output onto the base 1 for printing the thread. The points at which no material is applied to the base 1 in the region of the interruption are marked by dashed circles. The theoretical line 26 of the dot-dash line marks the theoretical position of the central line of the interrupted line to be printed, predetermined by the geometric data.

If the memory 19 stores geometric data for uninterrupted solid lines, all emitters 12 of the emitter row associated with the respective activation location emit at each activation location. In this case, the material portion is also output onto the base 1 at the location marked by the dashed circle, in addition to the location marked by the full black circle.

As can be seen in fig. 11A, the center point of the material fraction output by the emitter 12, which is approximately in the center of the emitter assembly 11 in the direction of extension of the emitter assembly 11, is either on the theoretical line 26 or has only a very small distance from it. As the spacing from the center increases, the deviation increases toward the outer and inner edges of the print zone, respectively. The maximum deviation occurs at the outer and inner edges of the print zone.

Fig. 11B shows a printed image which is obtained when the interrupted line stored in the memory 12 is printed by a method which is not in accordance with the invention, which differs from the method in accordance with the invention in that the radius of the reference circle line concentric with the axis of rotation 2 corresponds to the first radial distance R1. The actuating points 28 adjacent to one another in the circumferential direction are offset from one another about the axis of rotation 2 by a constant angle β, which is smaller than the angle α in fig. 6. In this case, the center point of the material portion output by the transmitter 12 which is furthest away from the axis of rotation 2 in the respective transmitter row 13A, 13B, 13C is either on the theoretical line 26 or is only at a distance from this theoretical line. The deviation becomes larger and larger from the outer edge of the print area to the inner edge thereof. The maximum deviation occurs at the inner edge of the printed area. As becomes apparent by comparing fig. 11A with fig. 11B, the maximum width w2 of the printed line in fig. 11B is greater than the maximum width w1 of the printed line according to the embodiment in fig. 11A due to a higher deviation. The widths w1 and w2 relate to the midpoint of the cured material portion output onto the base 1, respectively.

A comparison of fig. 11A with fig. 11B shows that the deviation of the material fraction output onto the base 1 from the theoretical line 26 in fig. 11B is distributed more unevenly along the printed line than in the case of the line printed according to the method according to the invention in fig. 11A. The maximum value of the deviation in fig. 11B is also larger than that in fig. 11A.

In the embodiment shown in fig. 13, a plurality of emitter assemblies 11A, 11B, 11C, 11D are provided for printing rings 27A, 27B, 27C, 27D arranged concentrically with respect to the axis of rotation and bounded by inner and outer circular tracks, respectively. The transmitter assemblies 11A, 11B, 11C, 11D are each oriented with their longitudinal center axis in a radial direction with respect to the axis of rotation 2 and are arranged such that the distance of each transmitter assembly 11A, 11B, 11C, 11D from the axis of rotation 2 is different. As can be seen in fig. 13, the emitter assemblies 11A, 11B, 11C, 11D which are adjacent to one another in the radial direction are each arranged such that the printing rings associated therewith adjoin one another, so that a continuous printing area results in the radial direction, which printing area extends from the inner circular path of the printing ring 27A to the outer circular path of the printing ring 27D.

Each transmitter assembly 11A, 11B, 11C, 11D is assigned a respective reference circle line 25A, 25B, 25C, 25D arranged concentrically to the axis of rotation 2, the radii BA, BB, BC, BD of which correspond to the arithmetic mean of a first radial distance between the center of the transmitter 12 of the associated transmitter assembly 11A, 11B, 11C, 11D which is furthest from the axis of rotation 2 and a second radial distance between the center of the transmitter 12 of the associated transmitter assembly 11A, 11B, 11C, 11D which is arranged closest to the axis of rotation 2 and the axis of rotation 2.

An activation signal is generated for each transmitter assembly 11A, 11B, 11C, 11D and temporarily stored. Furthermore, for each transmitter assembly 11A, 1511B, 11C, 11D a trigger signal is generated, which defines a trigger point for the pivot point between the associated transmitter assembly 11A, 11B, 11C, 11D and the base 1.

The angle between the adjacent activation points of the respective transmitter assemblies 11A, 11B, 11C, 11D corresponds to the angle between which the first radial line associated with the respective transmitter assembly 11A, 11B, 11C, 11D and the second radial line associated with the respective transmitter assembly 11A, 11B, 11C, 11D enclose.

The first radial line extends from the axis of rotation 2 towards the intersection between the first emitter row of the associated emitter assembly 11A, 11B, 11C, 11D and the reference circle line BA, BB, BC, BD associated with the emitter assembly 11A, 11B, 11C, 11D. The second radial line extends from the rotation axis 2 toward an intersection between the reference circle lines BA, BB, BC, BD of the second emitter row of the associated emitter assembly 11A, 11B, 11C, 11D adjacent to the first emitter row in the circumferential direction of the rotation axis 2 and the emitter assemblies 11A, 11B, 11C, 11D.

At the triggering points associated with the respective transmitter assemblies 11A, 11B, 11C, 11D, the transmitters 12 of the respective transmitter assembly 11A, 11B, 11C, 11D are each actuated in such a way that only the transmitter 12 in which the previously temporarily stored activation signal of the respective transmitter assembly 11A, 11B, 11C, 11D was set outputs material.

In the exemplary embodiment in fig. 14, two emitter assemblies 11A, 11A ' or 11B, 11B ' or 11C, 11C ' or 11D, 11D ' are arranged on each printing ring 27A, 27B, 27C, 27D, respectively, offset from one another in the circumferential direction, said emitter assemblies being associated with different printing modules 29, 29 '. Each of these print modules operates according to the method described above. In a corresponding manner, if necessary, more than two emitter assemblies 11A, 11A ' or 11B, 11B ' or 11C, 11C or 11D, 11D ' can also be arranged offset from one another in the circumferential direction on a printing ring. Different materials can be applied to the base 1 with the respective printing modules 29, 29'. These materials may differ from each other, in particular with respect to their color or with respect to their mechanical properties.

As can be seen from fig. 15, the transmitter assembly 11 may also have a plurality of transmitter rows of groups 28, in which the transmitters 12 of the respective groups 28 are offset or shifted relative to one another in the plane of the transmitters 12, perpendicular to the longitudinal extent of the transmitter rows.

Each group 28 has the same number and arrangement of transmitter columns or transmitters 12, respectively. Within a group 28, the emitter rows associated with the respective group 28 are offset from one another approximately in the longitudinal extension direction of the emitter rows, wherein the offset V is smaller than the grid pitch d of the emitters 12 within an emitter row. The grid pitch d is understood here to be the pitch of the center points of the emitters 12 of one nozzle row which are adjacent to one another, i.e. the pitch of the center of area of the nozzle openings of one emitter row relative to one another.

The spacing between the mutually adjacent emitter columns of one group 28 may be smaller than the spacing of the mutually adjacent groups (fig. 15). But these spacings may also be identical (fig. 16).

In the exemplary embodiment of the invention shown in fig. 17 to 19, a device is provided, which has a container 30 in which a liquid, pasty or powdery material 31 is applied to the base 1. For irradiating the material 31 with the high-energy electromagnetic radiation 32, the device has an emitter assembly 11, 11A, 11B, 11C, 11D with a plurality of radiation emitters 12 spaced apart from one another, which are each embodied as a light-emitting diode. In order to converge or focus the radiation 32 output by the individual emitters 12, in each case an optical arrangement, which is not shown in detail in the drawing, is arranged in the beam path of the emitters 12.

The wavelength and power of the electromagnetic radiation 32 that can be generated by means of the emitter 12 are matched to the flowable material 31 in such a way that it can be cured at the irradiation site by irradiation with the electromagnetic radiation 32. In the case of a liquid or flowable material 31, "curing" is understood to mean that said material 31 hardens into a solid material, in particular by crosslinking of polymers and/or copolymers contained in the material. In the case of a powdery material 31, "solidification" is understood to mean that the material particles present as solid particles are heated and subsequently cooled by irradiation with electromagnetic radiation 32 in such a way that they are fixedly connected to one another.

The emitter assemblies 11, 11A, 11B, 11C, 11D have a plurality of emitter columns 13A, 13B, 13C in which the center points of the emitters 12 are respectively offset from one another in a straight line. The arrangement of the radiation emitters 12 corresponds to the arrangement of the emitters 12 in fig. 3, 6, 8, 10 and 12 to 16, which are embodied as nozzles, so that the description of the emitter assemblies 11, 11A, 11B, 11C, 11D shown in the figures applies correspondingly to the exemplary embodiments according to fig. 17 to 19, with the following differences: the emitter 12 in the embodiment according to fig. 17 to 19 outputs radiation 32 instead of material, and the radiation 32 is directed at the flowable material 31.

The base is positioned in the container 30 in a rotary manner about the axis of rotation 2 relative to the emitter assemblies 11, 11A, 11B, 11C, 11D, and the radiation generated by means of the emitters 12 is directed onto the material layer at the surface of the material 31 in such a way that the material 31 is solidified at least one irradiation site.

The transmitter assemblies 11 are connected to a print buffer 15, in which the activation signal can be temporarily stored for each transmitter of the transmitter assemblies 11. For actuating the radiation emitters 12, an actuating device is provided, which has an actuation input, and in each case one actuation received at the actuation input, all emitters 12 of the emitter assemblies 11 for which a value "1" is respectively stored in the print buffer 15 are radiated in the direction of the material 31. The emitter 12 for which the value "0" is stored in the print buffer is not manipulated upon receipt of the trigger, i.e. the emitter 12 does not output radiation. Figures 4, 6 and 8 (which illustrate activation signal values for the emitter assemblies 11 at various trigger sites for the devices shown in figures 1 and 2) are correspondingly applicable to the embodiments in figures 17 to 19.

In the exemplary embodiment shown in fig. 17 to 19, the base 1 is in driving connection with a first positioning device which has a first drive motor 4 by means of which the base 1 can be driven in rotation in the direction of the arrow 5 and can be positioned in accordance with a rotational position setpoint signal provided by the control device 6. For this purpose, the first drive motor 4 is connected to a first position controller integrated into the control device 6, which has a decoder 7 for detecting a rotational position signal for the base 1. By means of the first positioning device, the base 1 can be rotated continuously and without stopping about the axis of rotation 2 relative to the holding device 3 over almost any angle of more than 360 °.

The base 1 is also in driving connection with a second positioning device having a second drive motor 8, by means of which the base 1 is movable up and down in the direction of the double arrow 9 relative to the holding device 3 and can be positioned in accordance with the height position setpoint signal provided by the control device 6 (fig. 19). The positioning can be performed stepwise or continuously. For this purpose, the second drive motor 8 is connected to a second position controller integrated into the control device 6, which has a position sensor 10 for detecting the height position of the base 1.