WO2023040290A1 - Three-dimensional object printing method, data processing apparatus, and computer device - Google Patents

Abstract

The present application provides a three-dimensional object printing method, a data processing apparatus, and a computer device. The method comprises: acquiring a three-dimensional digital model of an object to be printed, and obtaining multiple slice layers; making multiple parallel lines along a stacking direction of the slice layers to acquire an intersection point sequence; determining a transition point in the intersection point sequence, a transition point being an intersection point between an nth slice layer and an (n +1)th slice layer of the three-dimensional digital model; determining a transition region and a non-transition region in the nth slice layer according to the transition point; determining to print the non-transition area using a first printing mode, and determining to print the transition area using a second printing mode, a second physical ink quantity per unit volume injected in the second printing mode being lower than a first physical ink quantity injected per unit volume in the first printing mode; generating layer print data of the object to be printed for printing. The three-dimensional object printing method provided by the present application can improve the problem of surface layer patterns on an object, thereby improving surface precision of a three-dimensional printed object.

Description

Three-dimensional object printing method, data processing device and computer equipment

This application claims the priority of the Chinese patent application with the application number 202111090913.3 and the title of the invention "three-dimensional object printing method, data processing device and computer equipment" submitted to the China Patent Office on September 17, 2021, the entire contents of which are incorporated by reference in this application.

technical field

The present application relates to the technical field of three-dimensional printing, in particular to a three-dimensional object printing method, data processing device and computer equipment.

Background technique

The main process of the three-dimensional object printing technology is to obtain the digital model of the three-dimensional object, slice and layer the digital model in the stacking direction, and perform data processing and conversion on each slice layer to obtain the printing data of each slice layer , and then the printing device performs layer-by-layer printing according to the slice layer printing data and superimposes to manufacture a three-dimensional object.

Since the essence of 3D printing is the superimposition of several thin layers of a certain thickness, when the 3D digital model has an inclined surface, the edge data of the slice layer is easily lost, and a "step effect" will be formed on the boundary. As a result, layer patterns appear on the surface of the printed three-dimensional object, which makes the surface precision of the final formed object poor.

application content

Embodiments of the present application provide a three-dimensional object printing method, a data processing device, and computer equipment, which can improve the layering problem on the surface of the object, thereby improving the surface accuracy of the three-dimensional printed object.

In a first aspect, the present application provides a method for printing a three-dimensional object, the method comprising:

Obtain a three-dimensional digital model of the object to be printed, and slice and layer the three-dimensional digital model to obtain a multi-layer slice layer; draw a number of parallel lines along the stacking direction of the slice layer, and obtain all the parallel lines and the three-dimensional A sequence of intersection points of the digital model; determining a transition point in the sequence of intersection points, the transition point being an intersection point between the nth slice layer and the n+1th slice layer of the three-dimensional digital model, where n is An integer greater than or equal to 1; determine the transition area and non-transition area in the nth slice layer according to the transition point; determine to print the non-transition area in the first printing mode, and determine to print the non-transition area in the second printing mode The transition region, wherein, the second solid ink volume value ejected in the unit volume of the second printing mode is smaller than the first solid ink volume value ejected in the unit volume of the first printing mode; the object to be printed is generated The layer printing data, to instruct the printing device to print based on the layer printing data to obtain a three-dimensional object, the layer printing data includes the first entity ink volume value and the second entity ink volume value.

With reference to the first aspect, in a feasible implementation manner, the determining the transition point in the intersection sequence includes:

Set the stacking direction of the slice layer as the Z-axis direction, the height of the nth slice layer is Z _n , and the height of the n+1th slice layer is Z _n+1 , it is determined along the Z-axis direction at The intersection point between the nth slice layer and the n+1th slice layer in the section (Z _n , Z _n+1 ) is a transition point, and the height of the transition point is Z _x .

With reference to the first aspect, in a feasible implementation manner, the drawing several parallel lines along the stacking direction of the sliced layers includes:

Determine the rectangle that can contain the maximum projection of the three-dimensional digital model in the reference plane perpendicular to the stacking direction of the slice layer, and divide the rectangle into several grids;

Draw parallel lines perpendicular to the reference plane with each of the grids as the base point.

With reference to the first aspect, in a feasible implementation manner, based on Zn ₊₁ - _Zn , the value of the first solid ink quantity ejected per unit volume for printing the non-transitional region is determined;

Based on Z _x - _{Z n} or Z _n+1 - Z _x , the value of the second solid ink ejected within the unit volume of printing the transition area is determined.

With reference to the first aspect, in a feasible implementation manner, the first entity ink volume value ejected per unit volume for printing the non-transitional area is determined based on the size of ink droplets that can be ejected by the print head;

Based on the value of _Zx - _Zn or Zn ₊₁ - _Zx and the size of the ink drop that can be ejected by the print head, the value of the second solid ink quantity ejected in the unit volume of printing the transition area is determined.

With reference to the first aspect, in a feasible implementation manner, the transition area includes a printing area and a non-printing area, and in the non-printing area, the value of the second solid ink ejected per unit volume is zero.

With reference to the first aspect, in a feasible implementation manner, the height of the transition region is determined according to the height difference between the nth slice layer and the n+1th slice layer and the minimum ink droplet size that can be ejected by the print head. Printable area and non-printable area.

With reference to the first aspect, in a feasible implementation manner, before determining to use the first printing mode to print the non-transitional area and determining to use the second printing mode to print the transitional area, the method further includes:

determining the support points in the nth slice layer according to all the intersection points of all the intersection point sequences and the height of the nth slice layer;

A support area in the nth slice layer is determined according to the support points.

With reference to the first aspect, in a feasible implementation manner, determining the support points in the n-th slice layer according to all the intersection points of all the intersection point sequences and the height of the n-th slice layer includes:

The stacking direction of the slice layer is set as the Z-axis direction, the intersection point of the parallel line and the reference plane perpendicular to the Z-axis direction is T ₀ , and the multiple intersection points in the intersection point sequence corresponding to the parallel line are pressed by The Z-axis coordinates are sorted from small to large as T ₁ , T ₂ ,..., T _2k ;

Determining the point corresponding to the intersection point T ₀ in the n-th slice layer as a support point, where the height of the n-th slice layer is set to be Z _n , and Z _n is at (T ₀ , T ₁ ), (T ₂ , T ₃ ), ..., (T _2(k-1) , T _2k-1 ) within the section of one of them.

With reference to the first aspect, in a feasible implementation manner, before generating the layer printing data of the object to be printed, the method further includes:

determining whether there is an overlapping area between the support area and the transition area;

When there is an overlapping area between the support area and the transition area, it is determined to use the first printing mode to print the non-overlapping area in the support area, and it is determined to use the second printing mode to print the overlapping area in the support area, wherein the The second supporting ink volume value ejected per unit volume in the second printing mode is smaller than the first supporting ink volume value ejected per unit volume in the first printing mode;

When there is no overlapping area between the support area and the transition area, it is determined to use the first printing mode to print the support area.

With reference to the first aspect, in a feasible implementation manner, the ink droplet ejected in the unit volume in the first printing mode is a standard ink droplet, and the size of a single ink droplet ejected in the second printing mode is smaller than a single ink droplet The size of a standard ink drop.

With reference to the first aspect, in a feasible implementation manner, the number of ink droplets ejected per unit volume in the second printing mode is smaller than the number of ink droplets ejected in unit volume in the first printing mode.

With reference to the first aspect, in a feasible implementation manner, the ink droplet viscosity value ejected in the second printing mode is lower than the ink droplet viscosity value ejected in the first printing mode.

In a second aspect, an embodiment of the present application provides a data processing device, including a memory, a processor, and a computer program stored in the memory and operable on the processor. When the processor executes the computer program, Realize the three-dimensional object printing method described in the first aspect.

In the third aspect, the embodiment of the present application provides a non-transitory computer-readable storage medium, the storage medium includes a stored program, and when the program is running, the device where the storage medium is located is controlled to execute the three-dimensional Object printing method.

In a fourth aspect, an embodiment of the present application provides a computer device, including a memory, a processor, and a computer program stored in the memory and operable on the processor, wherein the processor executes the The computer program realizes the three-dimensional object printing method described in the first aspect.

The technical solution of the present application has at least the following beneficial effects:

Determining a transition point between adjacent slice layers by intersecting a series of parallel lines along the stacking direction of the three-dimensional digital model with the three-dimensional digital model, and by determining a transition region in the slice layer according to the determined plurality of transition points, and then using the first One printing mode prints the non-transitional area, and the second printing mode is used to print the transitional area, and the second solid ink volume value ejected in the unit volume by the second printing mode is controlled to be smaller than the first ink volume ejected in the unit volume in the first printing mode. The solid ink volume value makes the solid ink volume value smaller when printing the transition area, which improves the layering problem on the surface of the object, thereby improving the surface accuracy of the 3D printed object.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present application. For Those of ordinary skill in the art can also obtain other drawings based on these drawings without any creative effort.

FIG. 1 is a schematic diagram of a three-dimensional digital model of an object to be printed and a structure diagram of the formed three-dimensional object provided by the prior art.

FIG. 2 is a flow chart of a three-dimensional object printing method provided by an embodiment of the present application.

Fig. 3a is a schematic diagram of a three-dimensional digital model and a slice layer provided by an embodiment of the present application.

Fig. 3b is a schematic diagram of the three-dimensional digital model provided by the embodiment of the present application and the parallel lines emanating from the reference plane.

Fig. 3c is a schematic diagram of slice layers and transition points provided by the embodiment of the present application.

Fig. 3d is a schematic diagram of a slice layer with a transition region provided by an embodiment of the present application.

Fig. 4 is a schematic diagram of the three-dimensional digital model of the object to be printed and the formed three-dimensional object provided by the embodiment of the present application.

Fig. 5a is a first schematic diagram of the printing layer provided by the embodiment of the present application.

Fig. 5b is a second schematic diagram of the printing layer provided by the embodiment of the present application.

FIG. 6 is a first schematic diagram of the determination process of the printing area and the non-printing area in the transition area provided by the embodiment of the present application.

FIG. 7 is a second schematic diagram of the determination process of the printing area and the non-printing area in the transition area provided by the embodiment of the present application.

FIG. 8 is a third schematic diagram of the determination process of the printing area and the non-printing area in the transition area provided by the embodiment of the present application.

Fig. 9 is a flowchart of a three-dimensional object printing method provided by another embodiment of the present application.

Fig. 10a is a schematic diagram of a 3D digital model and rays emitted from a reference plane provided by another embodiment of the present application.

Fig. 10b is a schematic diagram of a slice layer with a support area provided by another embodiment of the present application.

Fig. 11a, Fig. 11b, Fig. 11c, and Fig. 11d are respectively schematic diagrams of a slice layer and a print layer provided by another embodiment of the present application.

Detailed ways

In order to better understand the technical solutions of the present application, the embodiments of the present application will be described in detail below in conjunction with the accompanying drawings.

It should be clear that the described embodiments are only some of the embodiments of the present application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of this application.

Terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms "a", "said" and "the" used in the embodiments of this application and the appended claims are also intended to include plural forms unless the context clearly indicates otherwise.

It should be understood that the term "and/or" used herein is only an association relationship describing associated objects, which means that there may be three relationships, for example, A and/or B, which may mean that A exists alone, and A and B exist simultaneously. B, there are three situations of B alone. In addition, the character "/" in this article generally indicates that the contextual objects are an "or" relationship.

Fig. 1 is a schematic structural diagram of the three-dimensional digital model of the object to be printed and the formed three-dimensional object provided by the prior art. As shown in Fig. 1, before printing the three-dimensional object, the three-dimensional digital model 10 of the object to be printed needs to be sliced and layered , to obtain multiple slice layers and layer image data of multiple slice layers.

Since a 3D printed three-dimensional object is composed of several slice layers of a certain thickness, when the three-dimensional digital model 10 has an inclined surface, the edge data of the slice layers is easily lost, and a "step effect" will be formed on the boundary. That is, the actual shape of the surface of the formed three-dimensional object 11 is a set of distinct layers that are distinctly stepped, rather than the required smooth contour, resulting in poor surface accuracy of the three-dimensional object 11 . Moreover, the smaller the slope of the three-dimensional digital model 10 of the object to be printed, the more obvious the step effect of the formed three-dimensional object 11 .

At present, it is generally possible to build three-dimensional objects by printing thinner slice layers. But as the thickness of the slice layer decreases, the slice layer becomes thinner and the laminae become shallower and thus less noticeable. Moreover, after the slice layer becomes thinner, the number of slice layers constituting the three-dimensional object increases, which increases the printing workload of the three-dimensional printing system and increases the time required to construct the three-dimensional object, which affects the forming efficiency of the three-dimensional object. In addition, using a thinner slice layer to build a three-dimensional object, the data sent by the data processing device to the three-dimensional printing device is also greatly increased, and the printing accuracy of the three-dimensional printing device must also be increased.

In order to improve the surface accuracy of the three-dimensional object 11, FIG. 2 is a flow chart of the three-dimensional object printing method provided by the embodiment of the present application. As shown in FIG. 2, the present application provides a three-dimensional object printing method, and the method includes the following steps:

S10, acquiring a three-dimensional digital model of the object to be printed, and performing slices and layers on the three-dimensional digital model to obtain multiple slice layers;

S20, making several parallel lines along the stacking direction of the slice layer, and obtaining the intersection sequence of all parallel lines and the three-dimensional digital model;

S30, determine the transition point in the intersection point sequence, the transition point is the intersection point between the nth slice layer and the n+1th slice layer of the three-dimensional digital model, where n is an integer greater than or equal to 1;

S40, determine the transition area and the non-transition area in the nth slice layer according to the transition point;

S50. Determine to use the first printing mode to print the non-transitional area, and determine to use the second printing mode to print the transitional area, wherein the value of the second solid ink ejected in the unit volume of the second printing mode is smaller than that of the first printing mode in the unit volume The value of the ink volume of the first entity ejected;

S60. Generate layer printing data of the object to be printed to instruct the printing device to print to obtain a three-dimensional object based on the layer printing data, where the layer printing data includes a first entity ink volume value and a second entity ink volume value.

In the above scheme, the transition points between adjacent slice layers are determined by the intersection points of a series of parallel lines along the stacking direction of the three-dimensional digital model and the three-dimensional digital model, and the transition in the slice layer is determined by the determined plurality of transition points area, and then use the first printing mode to print the non-transitional area, and use the second printing mode to print the transitional area, by controlling the value of the second solid ink ejected in the unit volume of the second printing mode to be less than the first printing mode in the unit volume The first solid ink volume value of the inner jet makes the solid ink volume value smaller when printing the transition area, which improves the problem of layering on the surface of the object, thereby improving the surface accuracy of the three-dimensional printed object.

Following concrete embodiment introduces this scheme:

S10. Obtain a three-dimensional digital model of the object to be printed, and slice and layer the three-dimensional digital model to obtain multiple slice layers.

Specifically, the 3D digital model 10 of the object to be printed can be sliced and layered by a data processing device (slicing software). The data format of the 3D digital model 10 includes STL data format, PLY data format or WRL data format.

The 3D digital model of the object to be printed can be stored in the data processing device of the 3D printing device, or transmitted externally to the data processing device of the 3D printing device, for example, saved to the data processing device of the 3D printing device through a network or an interface. The data processing device may include a memory, a processor, and a computer program stored in the memory and operable on the processor. When the processor executes the computer program, the above-mentioned three-dimensional object printing method can be realized.

In a specific embodiment, the three-dimensional digital model can define at least part of the three-dimensional geometric model of the object to be printed, including the shape and range of at least a part of the three-dimensional object, such as a solid part, in the three-dimensional coordinate system. Wherein, the polygonal surface is used to describe the contour of the surface of the three-dimensional geometric model, and the polygonal surface may include the space coordinates of the corresponding part of the three-dimensional geometric model. The shape of the polygonal patch can be triangular or quadrilateral.

In the embodiment of the present application, the stacking direction of the slice layers is defined as the growth direction of the three-dimensional object, that is, the slice layers are stacked and grown along the Z-axis direction to form a three-dimensional object, and there is a certain interval between adjacent slice layers. It can be understood that, in other embodiments, the growth direction of the three-dimensional object may also be the X-axis direction or the Y-axis direction, which is not limited here.

As shown in Figure 3a, the 3D digital model of the object to be printed is sliced and layered using the slice plane to obtain multiple slice layers. Each slice plane has multiple intersection points with the 3D digital model, and each intersection point is connected end to end to obtain the Contour lines, such as the nth slice layer and the n+1th slice layer. A slice layer can correspond to one contour line or multiple contour lines. The slice layer defines each print layer produced in the 3D printing process, and the outline defines the shape and extent of the solid part of the print layer formed by printing.

S20, making several parallel lines along the stacking direction of the slice layers, and obtaining a sequence of intersection points between all the parallel lines and the three-dimensional digital model.

In the embodiment of the present application, several parallel lines are drawn along the stacking direction of the slice layers, wherein the parallel lines may include at least one of several parallel straight lines, rays, and line segments. It can be understood that in step S20, it is sufficient that the formed parallel lines can completely surround the three-dimensional digital model, that is, the outer contour of the three-dimensional digital model is located within the projection range of the parallel lines. Further, an intersection point between each parallel line and the three-dimensional digital model is determined, and a sequence of intersection points between all parallel lines and the three-dimensional digital model is obtained.

Specifically, draw several parallel lines along the stacking direction of slice layers, which may include:

Determining a rectangle that can contain the maximum projection of the three-dimensional digital model in a reference plane perpendicular to the stacking direction of the slice layer, and dividing the rectangle into several grids;

Draw parallel lines perpendicular to the datum plane with each grid as the base point.

Exemplarily, as shown in Figure 3b, first, determine the boundary coordinate information X _min , X _max , Y _min , Y _max that can contain the maximum projection of the three-dimensional digital model in the reference plane perpendicular to the stacking direction of the slice layer, so that A rectangle that can contain the largest projection of the three-dimensional digital model can be determined. In this embodiment, assuming that the stacking direction of the slice layers is the Z-axis direction, the reference plane is the XY plane. As shown in Fig. 3b, the lowest point of the three-dimensional digital model may be on the reference plane, and in other embodiments, the lowest point of the three-dimensional digital model may also be higher than the reference plane. Preferably, the rectangle is the smallest rectangle capable of containing the largest projection of the three-dimensional digital model.

Then, in the rectangle, draw equidistant parallel hatching lines on the X-axis and Y-axis at preset intervals to obtain several grids. It should be noted that the smaller the interval between the hatching lines, the more the number of unit grids and the higher the accuracy. High, but the greater the amount of calculation required by the digital processing module, the greater the value of the line spacing, the smaller the number of unit grids, and the lower the accuracy. In this embodiment, the size of the grid can be set by itself, preferably a pixel size. Then, draw parallel lines perpendicular to the reference plane with each grid as the base point. The parallel lines can be rays as shown in FIG. 3b, and the starting point of the rays is the base point; The base point can be the center point of the grid as shown in Figure 3b, and in other embodiments, the base point can also be the boundary point of the grid, and each base point corresponds to a line.

Finally, traverse the parallel lines from all the grids on the datum plane, and calculate the intersection point of each parallel line with the 3D digital model. Specifically, you can extract the polygonal patches that each parallel line passes through, and calculate the intersection points one by one, judge whether the intersection points are located in the polygonal patch, discard the intersection points that are not in the polygonal patch, and save the intersection points that are located in the polygonal patch or on the boundary , forming the intersection sequence of the parallel line and the 3D digital model.

S30. Determine a transition point in the intersection point sequence, where the transition point is an intersection point between the nth slice layer and the n+1th slice layer of the three-dimensional digital model, where n is an integer greater than or equal to 1.

As shown in Figure 3c, S30 may specifically include:

Set the stacking direction of the slice layer as the Z-axis direction, the height of the n-th slice layer is Z _n , and the height of the n+1-th slice layer is Z _n+1 , determine along the Z-axis direction at (Z _n , Z _n The intersection point between the nth slice layer and the n+1th slice layer in the ₊₁ ) section is a transition point, and the height of the transition point is Z _x .

In a specific implementation, it can be judged whether the Z-axis coordinates Z _x of all intersection points in the intersection sequence are in the (Z _n , Z _n+1 ) section; if there is a Z-axis coordinate Z _x of the intersection points in (Z _n , Z _n+1 ) section, the intersection point is determined to be the transition point between the nth slice layer and the n+1th slice layer.

S40. Determine a transition area and a non-transition area in the nth slice layer according to the transition point.

Specifically, according to multiple transition points between the n-th slice layer and the n+1-th slice layer, determine the corresponding point of the transition point on the n-th slice layer, and obtain the n-th slice according to the multiple corresponding points Transition regions in layers. As shown in Figure 3d, the transition region in the n-th slice layer is represented by a diagonal region.

S50. Determine to use the first printing mode to print the non-transitional area, and determine to use the second printing mode to print the transitional area, wherein the value of the second solid ink ejected in the unit volume of the second printing mode is smaller than that of the first printing mode in the unit volume The value of the first entity ink quantity ejected.

Specifically, as shown in FIG. 4, by applying different printing modes on a single slice layer to print different areas, the forming accuracy of the printing layer is improved, and the surface layer texture of the printed three-dimensional object 41 is significantly reduced, thereby improving the three-dimensional The surface accuracy of the object 41 is improved, and the shape of the printed three-dimensional object 41 is closer to the shape of the three-dimensional digital model 40 .

Taking Fig. 4 as an example, the present application does not specifically limit the proportional relationship between the value of the second solid ink ejected per unit volume in the printing transition area and the first solid ink ejected per unit volume in the non-transitional area , the ratio of the amount of solid ink ejected in unit volume in the second printing mode to the amount of solid ink ejected in unit volume in the first printing mode can be 0 to 99%, for example, 0, 25%, 30%, 50% , 60%, 75%, etc. For example, the first physical ink volume value in the first printing mode may be 1, and the second physical ink volume value in the second printing mode may be 0.7. It should be noted that the second printing mode may only contain one type of solid ink volume value ejected in a unit volume, or may include two types of solid ink volume values as shown in Figure 4, or may include more than two types, preferably in the form Decreasing or increasing gradient.

Further, the ink drop ejected in the first printing mode is a standard ink drop, and the size of a single ink drop ejected in the second printing mode is smaller than the size of a single standard ink drop. Therefore, under the condition that the number of ejected ink droplets is the same, the second solid ink quantity ejected in the unit volume in the second printing mode is smaller than the first solid ink quantity ejected in the unit volume in the first printing mode.

As shown in Figure 5a, in one embodiment, the ink drop ejected by the first printing mode is a standard ink drop, the standard ink drop is a large ink drop, and the ink drop ejected by the second printing mode is a medium ink drop and a small ink drop . Exemplarily, the large ink droplet may be 0.5ml, the medium ink droplet may be 0.2ml, and the small ink droplet may be 0.1ml. Changes in ink droplet size, ie, printing mode changes, can be achieved by fluid ejection devices capable of producing various droplet sizes. Fig. 5a is only for illustration, and the present embodiment does not specifically limit the size of the ink droplets ejected in the first printing mode and the second printing mode and the proportional relationship of the sizes.

In another embodiment, the number of ink droplets ejected per unit volume in the second printing mode is smaller than the number of ink droplets ejected in unit volume in the first printing mode. Exemplarily, the number of ink drops ejected per unit volume in the second printing mode may be one drop, and the number of ink drops ejected per unit volume in the first printing mode may be three drops. Therefore, it can be realized that in the case of the same ejected ink droplet size, the second solid ink quantity ejected in the unit volume in the second printing mode is smaller than the first solid ink quantity ejected in the unit volume in the first printing mode.

As shown in Figure 5b, in this embodiment, the unit volume is determined as a voxel size, three ink droplets are ejected for each voxel in the first printing mode, and two ink droplets are ejected for each voxel in the second printing mode Or a drop of ink. FIG. 5b is only for illustration, and this embodiment does not specifically limit the number of ink droplets ejected per unit volume and the proportional relationship between the first printing mode and the second printing mode.

Further, the ink droplet viscosity value ejected in the second printing mode is lower than the ink droplet viscosity value ejected in the first printing mode. On the basis that the value of the second solid ink volume ejected in the unit volume in the second printing mode is smaller than the first solid ink volume value ejected in the unit volume in the first printing mode, at the same time, the viscosity value of the ink droplets ejected in the second printing mode is If it is lower, the fluidity of the ink droplets ejected by the second printing mode is better, so that the transition area printed by the second printing mode, such as the edge, is clearer, and the slope of the printing layer is more obvious.

Further, in order to print the transition area more accurately, step S50 also includes:

Based on Zn ₊₁ - _Zn , determine the first entity ink quantity value ejected in the unit volume of the printing non-transitional area;

Based on Z _x - _{Z n} or Z _n+1 - Z _x , the value of the second solid ink ejected within the unit volume of the printing transition area is determined.

Specifically, Z _n+1 -Z _n represents the interval between adjacent slice layers, that is, the thickness of the slice layers. When the three-dimensional digital model is sliced and layered, and the slice layers are layered at constant intervals, then Z _n+1 -Z _n is a constant value. In other embodiments, the three-dimensional digital model may also be sliced and layered at varying intervals, and Z _n+1 - _{Z n} are variable values. It can be understood that, based on Zn ₊₁ - _Zn , when the first print mode is used to print the non-transition area, the first solid ink volume value ejected per unit volume can be understood, and the first print mode is used to print the non-transition area The first solid ink volume value ejected in a unit volume can form a printing layer with a layer thickness of Zn ₊₁ - _Zn . Therefore, the ejected ink volume can include part of the ink volume that will be removed by the leveling device.

Further, based on Z _x -Z _n or Z _n+1 -Z _x, the value of the second solid ink quantity ejected within a unit volume of the printing transition area is determined. That is, the height of the printed transition area is determined according to the determined height Z _x of the transition point, which realizes more accurate printing of the transition area, further improves the surface texture problem of the three-dimensional object, and improves the surface accuracy of the three-dimensional object. Of course, since the size of the ink drop that can be ejected by the print head cannot be changed arbitrarily, in this embodiment, the first physical ink volume value and the second physical ink volume value can be determined according to the size of the ink drop that can be ejected by the print head. Specifically, the number of ink droplets printed in the non-transition area can be determined according to the value of Zn ₊₁ - _Zn and the height of ink droplets, and according to the value of _Zx - _Zn or _Zn+1 - _Zx and the ink The drop height determines the number of ink drops printed in the transition area. Of course, in actual operation, the value of Zn ₊₁ - _Zn can be pre-determined based on the size of the ink drop, and the value of Zn ₊₁ - _Zn can be set as the height of 3 ink droplets, 4 ink droplets height etc., for example, the value of Zn ₊₁ - _Zn can be determined according to the type of printing material. Taking ink droplets of one size that can be ejected by the print head as an example, when the ink droplets that can be ejected by the print head along the X direction, Y direction and Z direction are respectively (a, b, c), Z _n+1 -Z _n It is set to the height of 4 ink drops, that is, Z _n+1 -Z _n =4c, at this time, the ink volume value of the first entity is 4 ink drops; and when Z _x -Z _n =d or Z _n+1 - When Z _x =d, make N=d/c (due to d<4c, then N<4), and determine the number of ink drops that should be printed at the position of Z _x according to the value of N. Specifically, N can be taken as To determine the number of ink drops that should be printed at the position of Z _x , for example, N can be rounded up, down or rounded up according to the actual situation; more specifically, the smallest ink drop that can be ejected by the print head The size is (3, 3, 3), d=10 as an example, N=10/3=3.3333, at this time, if N is rounded down, it will be 3, if N is rounded up, it will be 4, and N will be rounded up Then it is 3, therefore, the actual printed ink volume value of the second entity is N ink droplets.

In other embodiments, when there are multiple sizes of ink droplets that can be ejected by the print head, it can also be based on the values of Z _n+1 -Z _n , Z _x -Z _n and Z _n+1 -Z _x One or more to combine ink droplets of different sizes to match the height of the transition point to obtain the first physical ink volume value and the second physical ink volume value.

Furthermore, in some embodiments, since the contour lines of the n-th slice layer and the n+1-th slice layer differ greatly in the horizontal direction (that is, in the X and Y directions), the contours in the transition region The slope of the line is too small, so there are some pixel positions where the number of ink drops that should be printed is 0, and there are many pixel positions in the transition area, and the calculation of the number of ink drops that should be ejected at each pixel position according to the above method may lead to a complicated calculation process And the efficiency is low. In this embodiment, the printing area and non-printing area of the transition area can be determined according to the height difference between the nth slice layer and the n+1th slice layer and the minimum ink droplet size that can be ejected by the print head, and then the printing area can be calculated. The number of ink drops that should be ejected at each pixel position in the area is enough, that is, the transition area includes the printing area and the non-printing area, and the value of the second solid ink ejected in the unit volume in the non-printing area is zero, which can reduce the calculation to increase computational efficiency.

Specifically, the printing area and non-printing area of the transition area are determined according to the height difference between the nth slice layer and the n+1th slice layer and the minimum ink droplet size that can be ejected by the print head, including:

Extending the outline of the nth slice layer to obtain the first extended area;

Perform an intersection operation on the projected surface on the area surrounded by the first extended area and the n+1th layer outline to obtain the first printing area;

Extending the outline of the n+1th slice layer to obtain a second extended area;

Perform an intersection operation on the projected surface on the second extended area and the area surrounded by the n-th layer outline to obtain the second printing area;

Performing a union operation on the first print area and the second print area to obtain the print area, and performing a complement operation on the transition area and the print area to obtain the non-print area;

Wherein, the extended width may be determined according to the height difference between the nth slice layer and the n+1th slice layer and the minimum size of ink droplets that can be ejected by the print head.

The following will not be described in detail in conjunction with Figure 6 and Figure 7:

FIG. 6 shows an example in which the outline of the n+1th slice layer is located within the outline of the nth slice layer.

As shown in Figure 6(b), the contour of the nth slice layer is expanded to obtain the first extended area A1; Intersection operation to obtain the first printing area C1, at this time, C1 is an empty set;

As shown in Figure 6 (a), the contour of the n+1th layer slice layer is expanded to obtain the second extended area A2; the second extended area A2 and the area B2 surrounded by the nth layer contour are captured on the projection The intersection operation is performed to obtain the second printing area C2; the union operation is performed on the first printing area C1 and the second printing area C2 to obtain the printing area P1, and the complement operation is performed on the transition area and the printing area to obtain the non-printing area.

FIG. 7 shows an example where the contour of the n+1th slice layer intersects the contour of the nth slice layer.

As shown in Figure 7(b), the contour of the nth slice layer is extended to obtain the first extended area A3; Intersection operation to obtain the first printing area C3;

As shown in Figure 7 (a), the contour of the n+1th layer slice layer is expanded to obtain the second extended area A4; The intersection operation is performed to obtain the second printing area C4; the union operation is performed on the first printing area C3 and the second printing area C4 to obtain the printing area P2, and the complement operation is performed on the transition area and the printing area to obtain the non-printing area.

In other embodiments, as shown in FIG. 8 , it is also possible to intersect the contour of the nth layer slice layer and the contour of the n+1th layer slice layer on the projection plane to obtain the intersection line o, and to obtain the intersection line o Expand to obtain the extended area O, and then use the extended area O and the area O(n) surrounded by the outline of the nth slice layer to perform an intersection operation to obtain the first printing area U1, and use the extended area and the n+1th layer The area O(n+1) surrounded by the outline of the slice layer is intersected to obtain the second printing area U2. At this time, U2 is an empty set, and finally the union operation is performed on the first printing area U1 and the second printing area U2 Get the print area U.

Wherein, the extended width may be determined according to the height difference between the nth slice layer and the n+1th slice layer and the minimum ink droplet size that can be ejected by the print head. Specifically, if the minimum ink drop size that can be ejected by the print head is (a ₀ , b ₀ , c ₀ ), the height difference Z _n+1 -Z between the n-th slice layer and the n+1-th slice layer _n = D as an example, the number of ink drops that should be printed at the pixel positions in the non-transition area is N0=D/c, in order to realize the step change of the height of the transition area, the number of ink drops at the pixel positions in the transition area can be reduced from N0 to 1, the width of the extended area is the width of N ₀ ink droplets. In some embodiments, the ink drop ejected by the printing head will spread in both the X direction and the Y direction after deposition, that is, in general, the size of the ink drop in the X direction and the Y direction is the same, that is, a ₀ =b ₀ , at this time, the width of the extended area is N ₀ *a ₀ .

In other embodiments, as shown in FIG. 9, after step S20 and before step S50, the printing method may further include:

Step S70, determining the support points in the nth slice layer according to all the intersection points of the intersection point sequence and the height of the nth slice layer;

Step S80, determining the support area in the nth slice layer according to the support points.

It should be noted that step S70 and step S80 may be performed synchronously with step S30 and step S40, or may be performed asynchronously, and it only needs to be guaranteed to be completed before step S90.

Due to certain structures on three-dimensional objects, such as internal holes, cantilever structures, etc., it is generally necessary to print to form a support structure. Without the addition of support structures, solid structures with internal holes tend to collapse during printing, or even fail to print. Therefore, it is necessary to identify the location on the three-dimensional digital model that needs to form a support structure, that is, to determine the support area in the slice layer.

In this embodiment, using the intersection sequence of all parallel lines obtained in step S20 and the three-dimensional digital model, according to the Z-axis coordinates of all intersection points in the intersection sequence and the Z-axis height of the slice layer, it is judged that the point on the three-dimensional digital model that needs a support structure; And according to the identified points on the three-dimensional digital model that need support structures, determine the support points in the slice layer; then determine the support areas in the slice layer according to the multiple support points in the slice layer.

In a specific implementation manner, step S70, according to all the intersection points of the intersection point sequence and the height of the n-th slice layer, determining the support point in the n-th slice layer includes:

Set the stacking direction of the slice layer as the Z-axis direction, the intersection of the parallel line and the reference plane perpendicular to the Z-axis direction is T ₀ , and sort the multiple intersection points in the intersection sequence corresponding to the parallel line from small to large according to the Z-axis coordinates is T ₁ , T ₂ , ..., T _2k ;

Determine the point corresponding to the intersection point T ₀ in the n-th slice layer as the support point, where the height of the n-th slice layer is set to Z _n , and Z _n is at (T ₀ , T ₁ ), (T ₂ , T ₃ ), ..., (T _2(k-1) , T _2k-1 ) within the section of one of them.

As shown in Figure 10a, in this embodiment, the stacking direction of sliced layers is the Z-axis direction, the reference plane perpendicular to the Z-axis direction is the XY plane, and the lowest point of the three-dimensional digital model can be on the reference plane or higher than datum plane. First, set the intersection point of the parallel line and the reference plane as T ₀ , and sort all the intersection points in the intersection point sequence corresponding to the parallel line from small to large according to the Z-axis coordinates as T ₁ , T ₂ , ..., T _2k .

It can be understood that when the lowest point of the three-dimensional digital model can be on the reference plane, T ₀ and T ₁ of some parallel lines can coincide. Then, it is judged whether the height Z _n of the slice layer n is in one of ((T ₀ , T ₁ ), (T ₂ , T ₃ ),..., (T _2(k-1) , T _2k-1 ) In the segment; when the height Z _n of the nth slice layer is in (T ₀ , T ₁ ), (T ₂ , T ₃ ),…, (T _2(k-1) , T _2k-1 ) If it is within a section of 1, the point corresponding to the starting point T ₀ on the nth slice layer is determined as the support point.

By traversing the intersection sequence of all parallel lines, multiple support points on the nth slice layer can be determined, so that the support region in the nth slice layer can be determined according to the multiple support points.

As shown in Figure 10b, the support regions in the n-th slice layer are indicated by gray areas.

In order to further improve the lamination problem on the surface of the object, the surface accuracy of the three-dimensional printed object is improved; after step S80 and before step S60, the method further includes:

Step S90, determining whether there is an overlapping area between the support area and the transition area;

Step S91, when there is an overlapping area between the support area and the transition area, determine to use the first printing mode to print the non-overlapping area in the support area, and determine to use the second printing mode to print the overlapping area in the support area, Wherein, the second support ink volume value ejected per unit volume in the second printing mode is smaller than the first support ink volume value ejected in unit volume in the first printing mode;

Step S50, when there is no overlapping area between the support area and the transition area, determine to use the first printing mode to print the support area. That is, in the actual printing process, the non-transition area includes the support area.

In a specific embodiment, when there is an overlapping area between the supporting area and the transition area, when printing the overlapping area in the supporting area, the second printing mode is used for printing, and the second printing mode ejects the second supporting ink amount value per unit volume ; When printing the non-overlapping area in the supporting area, use the first printing mode to print, the first printing mode ejects the first supporting ink volume value per unit volume, and the second supporting ink volume value is smaller than the first supporting ink volume value. When there is no overlapping area between the support area and the transition area, the support area is printed directly using the first printing mode.

As shown in Fig. 11a, the support region in the nth slice layer is represented by a gray region; as shown in Fig. 11b, the transition region in the nth slice layer is represented by a slanted region. When there is an overlapping area between the support area and the transition area, as shown in Figure 11c, the overlapping area is represented by a black area, and the non-overlapping area is represented by a gray area.

As shown in FIG. 11 d , the second printing mode is used for printing in the transition area of the n-th slice layer, and the first printing mode is used for printing in the non-transition area of the n-th slice layer. Wherein, the second solid ink quantity value ejected in the unit volume of the second printing mode is smaller than the first solid ink quantity value ejected in the unit volume of the first printing mode; The ink drop also ejects a solid ink drop, wherein the second support ink volume ejected per unit volume by the second printing mode is also smaller than the first support ink volume ejected per unit volume by the first print mode. It can be understood that the supporting ink droplets are ejected in the non-overlapping areas of the supporting areas using the first printing mode.

Using the second print mode, both support material ink drops and solid material ink drops may be ejected at the same location in the coincident region to simultaneously achieve the slope of the support structure and the slope of the solid structure. It can be understood that the support ink volume value and the solid ink volume value ejected at the same position in the overlapping area can be calculated based on Z _x −Z _n and Z _n+1 −Z _x .

Further, when using the second printing mode to spray both support material ink droplets and solid material ink droplets at the same position in the overlapping area, it is necessary to determine whether to spray support material ink droplets or solid material ink droplets first. In this embodiment , by determining whether the contour of the nth slice layer at this position is located inside or outside the contour of the n+1th slice layer, when it is determined that the contour of the nth slice layer at this position is located at the n+1th slice layer When it is determined that the contour of the nth slice layer at this position is outside the contour of the n+1th slice layer, ink droplets of the solid material are sprayed first. Taking Figure 7 as an example, when there is an overlapping area on the left side, since the contour of the nth slice layer is located inside the contour of the n+1th slice layer, ink droplets of the supporting material are first ejected; when there is an overlapping position on the right side , since the contour of the nth slice layer is located outside the contour of the n+1th slice layer, the ink droplets of the solid material are ejected first. .

Step S60, generate layer printing data of the object to be printed, and instruct the printing device to print based on the layer printing data to obtain a three-dimensional object, the layer printing data includes the first physical ink volume value and the second physical ink volume value.

In one embodiment, the layer printing data includes a first physical ink volume value and a second physical ink volume value. In other implementation manners, the layer printing data may further include a first supporting ink volume value and a second supporting ink volume value. According to the generated layer printing data, the three-dimensional printing device is controlled to print, and multiple printing layers are obtained, and the multiple printing layers are stacked to form a three-dimensional object. In the embodiment of the present application, the 3D printing device may use inkjet printing technology, more specifically, the 3D printing device may use inkjet ultraviolet curing 3D printing technology, or inkjet thermosetting 3D printing technology.

In the 3D object printing method 200 provided in the embodiment of the present application, the transition point between adjacent slice layers is determined through the intersection points of a series of parallel lines along the stacking direction of the slice layers of the 3D digital model and the 3D digital model, and the transition point between adjacent slice layers is determined according to the determined A plurality of transition points determine the transition area and non-transition area in the slice layer; then use the second printing mode to print in the transition area, and use the first printing mode to print in other areas, wherein the second printing mode is in the unit volume The second solid ink volume value of internal ejection is smaller than the first solid ink volume value ejected in unit volume in the first printing mode. Thus, the transition area in the slice layer is determined, and the transition area is printed using a printing mode with a smaller amount of ink ejected per unit volume, which improves the layering problem on the surface of the object, thereby improving the surface accuracy of the three-dimensional printed object.

The present application also provides a data processing device, including a memory, a processor, and a computer program stored in the memory and operable on the processor. When the processor executes the computer program, the above-mentioned three-dimensional object is realized. printing method.

In some embodiments, the data processing device can be integrated on the printing device as a module of the printing device. In other embodiments, the data processing device and the printing device may also be connected through a network. For example, the data processing device may be a computer device, such as a computing device such as a desktop computer, a notebook, a palmtop computer, or a cloud server.

The printing device may adopt inkjet printing technology, more specifically, the three-dimensional printing device 20 may adopt inkjet ultraviolet curing three-dimensional printing technology, or inkjet thermal curing three-dimensional printing technology, or other inkjet three-dimensional printing technology, for example, It is a fused deposition modeling technique.

An embodiment of the present application also provides a non-transitory computer-readable storage medium, the storage medium includes a stored program, and when the program is running, the device where the storage medium is located is controlled to execute the above three-dimensional object printing method.

The embodiment of the present application also provides a computer device. The computer device in this embodiment includes: a processor, a memory, and a computer program stored in the memory and operable on the processor. When the processor executes the computer program, the computer program in the embodiment is implemented. The three-dimensional object printing methods are not repeated here to avoid repetition.

The computer equipment may be computing equipment such as desktop computers, notebooks, palmtop computers, and cloud servers. A computer device may include, but is not limited to, a processor, memory. Those skilled in the art can understand that the computer equipment may include more or less components than shown in the figure, or combine certain components, or different components, for example, the computer equipment may also include input and output devices, network access devices, buses, etc. .

The so-called processor can be a central processing unit (Central Processing Unit, CPU), and can also be other general-purpose processors, digital signal processors (Digital Signal Processor, DSP), application specific integrated circuits (Application Specific Integrated Circuit, ASIC), on-site Programmable gate array (Field-Programmable Gate Array, FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor, or the processor may be any conventional processor, or the like.

The memory may be an internal storage unit of the computer device, such as a hard disk or internal memory of the computer device. The memory can also be an external storage device of the computer equipment, such as a plug-in hard disk equipped on the computer equipment, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, a flash memory card (Flash Card), etc. . Further, the memory may also include both an internal storage unit of the computer device and an external storage device. Memory is used to store computer programs and other programs and data required by computer equipment. The memory can also be used to temporarily store data that has been output or will be output.

The above are only preferred embodiments of the application, and are not intended to limit the application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the application shall be included in the protection of the application. within range.

Claims (16)

1. A three-dimensional object printing method, characterized in that the method comprises:

   Obtaining a three-dimensional digital model of the object to be printed, and slicing and layering the three-dimensional digital model to obtain multiple slice layers;

   making several parallel lines along the stacking direction of the slice layers, and obtaining the intersection sequence of all the parallel lines and the three-dimensional digital model;

   determining a transition point in the sequence of intersection points, the transition point being an intersection point between the nth slice layer and the n+1th slice layer of the three-dimensional digital model, where n is an integer greater than or equal to 1 ;

   determining a transition area and a non-transition area in the nth slice layer according to the transition point;

   It is determined to use the first printing mode to print the non-transitional area, and it is determined to use the second printing mode to print the transitional area, wherein the value of the second solid ink ejected per unit volume in the second printing mode is smaller than the first The ink volume value of the first entity ejected per unit volume in the printing mode;

   generating layer printing data of the object to be printed, to instruct a printing device to print based on the layer printing data to obtain a three-dimensional object, the layer printing data including the first entity ink volume value and the second entity ink volume value .
2. The printing method according to claim 1, wherein said determining the transition point in said intersection sequence comprises:

   Set the stacking direction of the slice layer as the Z-axis direction, the height of the nth slice layer is Z _n , and the height of the n+1th slice layer is Z _n+1 , it is determined along the Z-axis direction at The intersection point between the nth slice layer and the n+1th slice layer in the section (Z _n , Z _n+1 ) is a transition point, and the height of the transition point is Z _x .
3. The printing method according to claim 2, wherein said making several parallel lines along the stacking direction of said slice layers comprises:

   determining a rectangle capable of containing the maximum projection of the three-dimensional digital model in a reference plane perpendicular to the stacking direction of the slice layer, and dividing the rectangle into several grids;

   Draw parallel lines perpendicular to the reference plane with each of the grids as the base point.
4. The printing method according to claim 2, characterized in that, based on Zn ₊₁ - _Zn , it is determined to print the first solid ink volume value ejected in the unit volume of the non-transitional area;

   Based on Z _x - _{Z n} or Z _n+1 - Z _x , the value of the second solid ink ejected within the unit volume of printing the transition area is determined.
5. The printing method according to claim 2, characterized in that, based on the size of ink droplets that can be ejected by the print head, the value of the first solid ink quantity ejected in the unit volume of printing the non-transition area is determined;

   Based on the value of _Zx - _Zn or Zn ₊₁ - _Zx and the size of the ink drop that can be ejected by the print head, the value of the second solid ink quantity ejected in the unit volume of printing the transition area is determined.
6. The printing method according to claim 1, wherein the transition area includes a printing area and a non-printing area, and the value of the second solid ink ejected per unit volume in the non-printing area is zero.
7. The printing method according to claim 6, characterized in that the transition area is determined according to the height difference between the nth slice layer and the n+1th slice layer and the minimum ink droplet size that can be ejected by the print head Printable area and non-printable area.
8. The printing method according to claim 1, characterized in that, before determining to use the first printing mode to print the non-transitional area and determining to use the second printing mode to print the transitional area, the method further comprises:

   Determine the support points in the nth slice layer according to all the intersection points of all the intersection point sequences and the height of the nth slice layer;

   A support area in the nth slice layer is determined according to the support points.
9. The printing method according to claim 8, wherein, according to all the intersection points of all the intersection point sequences and the height of the nth slice layer, determining the support points in the nth slice layer includes:

   The stacking direction of the slice layer is set as the Z-axis direction, the intersection point of the parallel line and the reference plane perpendicular to the Z-axis direction is T ₀ , and the multiple intersection points in the intersection point sequence corresponding to the parallel line are pressed by The Z-axis coordinates are sorted from small to large as T ₁ , T ₂ ,..., T _2k ;

   Determining the point corresponding to the intersection point T ₀ in the n-th slice layer as a support point, where the height of the n-th slice layer is set to be Z _n , and Z _n is at (T ₀ , T ₁ ), (T ₂ , T ₃ ), ..., (T _2(k-1) , T _2k-1 ) within the section of one of them.
10. The printing method according to claim 8, wherein, before generating the layer printing data of the object to be printed, the method further comprises:

    determining whether there is an overlapping area between the support area and the transition area;

    When there is an overlapping area between the support area and the transition area, it is determined to use the first printing mode to print the non-overlapping area in the support area, and it is determined to use the second printing mode to print the overlapping area in the support area, wherein the The second supporting ink volume value ejected per unit volume in the second printing mode is smaller than the first supporting ink volume value ejected per unit volume in the first printing mode;

    When there is no overlapping area between the support area and the transition area, it is determined to use the first printing mode to print the support area.
11. The printing method according to any one of claims 1 to 10, characterized in that, the ink drop ejected in the unit volume in the first printing mode is a standard ink drop, and the single ink drop ejected in the second printing mode is The size is smaller than the size of a single said standard ink droplet.
12. The printing method according to any one of claims 1 to 10, wherein the number of ink droplets ejected per unit volume in the second printing mode is smaller than the number of ink droplets ejected per unit volume in the first printing mode .
13. The printing method according to any one of claims 1 to 10, characterized in that the ink droplet viscosity value ejected in the second printing mode is lower than the ink droplet viscosity value ejected in the first printing mode.
14. A data processing device, characterized by comprising a memory, a processor, and a computer program stored in the memory and operable on the processor, characterized in that, when the processor executes the computer program, the The three-dimensional object printing method described in any one of claims 1 to 13.
15. A non-transitory computer-readable storage medium, characterized in that the storage medium includes a stored program, and when the program is running, the device where the storage medium is located is controlled to execute the three-dimensional Object printing method.
16. A computer device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, characterized in that claims 1 to 13 are realized when the computer program is executed by the processor The three-dimensional object printing method described in any one.

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