3D printing method, device and system

Abstract

The present application relates to the field of 3D printing technology, and in particular to a 3D printing method, device, and system. The 3D printing method is applied to a control unit in a 3D printing system; the method is applied to a control unit in a 3D printing system; and the 3D printing system further comprises a piezoelectric inkjet print head, which is provided with a plurality of nozzles. In the present application, after identifying the edge of a graphic, line segments are intercepted based on the edge contour. For each specified edge contour segment, the piezoelectric inkjet print head is controlled to move along the specified edge contour segment and open the target nozzle to spray ink along the specified edge contour segment, so that the ink sprayed by the piezoelectric inkjet print head can form continuous dots on the edge of the graphic, or the dots merge with each other to form continuous lines, thereby fundamentally avoiding the appearance of step lines, improving the smoothness of the printed image and the printing efficiency, and thus enhancing the user experience.

Description

Technical Field

[0001] The present invention relates to the field of 3D printing technology, and in particular to a 3D printing method, device and system. Background Art

[0002] Existing inkjet printing technology primarily achieves image printing by controlling the relative movement and spraying between the print platform and the inkjet print head. During the printing process, the inkjet print head and the print platform move relative to each other in at least two of the three directions: X, Y, and Z. A common method is for the print head to move relative to the print platform in either the X or Y direction, spraying ink on demand according to the shape of the image. Computers divide the image into many small grids based on the pixel settings in the X and Y directions. However, each nozzle of the print head can only eject a minimum of one drop of ink, not 0.5 or 0.3 drops. Therefore, ink is either ejected or not ejected within a pixel grid. The print head determines whether to eject ink based on whether a graphic is present within the grid; if so, ink dots are ejected; if not, ink dots are not ejected. This printing method can produce step-like patterns on curves that are not perpendicular to the X or Y axes, resulting in an uneven image surface.

[0003] Existing inkjet printing technology produces step-like patterns when printing on curves that are not perpendicular to the X or Y axis, resulting in an uneven image surface. This not only affects the aesthetics of the image but also limits its application in applications requiring high-smoothness surfaces. Therefore, improving inkjet printing technology and enhancing the surface smoothness and quality of printed images is a pressing issue in the current technological field. Summary of the Invention

[0004] In view of this, the object of the present invention is to provide a 3D printing method, which is applied to a control unit in a 3D printing system; the 3D printing system also includes a 3D printer, which is connected to the control unit; the piezoelectric inkjet print head of the 3D printer is provided with a plurality of nozzles; the piezoelectric inkjet print head is connected to the control unit; the method comprises:

[0005] Acquire and identify the expected printing image, and obtain the edge contour corresponding to each sub-image in the expected printing image;

[0006] For each sub-image, performing line segment interception on the edge contour of the sub-image to obtain multiple edge contour line segments;

[0007] Extracting a specified edge contour line segment from a plurality of edge contour line segments; the specified edge contour line segment is an edge contour line segment that forms an angle with a coordinate axis in a preset piezoelectric inkjet print head movement coordinate system;

[0008] Controlling the piezoelectric inkjet print head to move along the specified edge contour segment and opening the target nozzles associated with the specified edge contour segment so that the target nozzles spray ink along the specified edge contour segment with one end point of the specified edge contour segment as a starting point and the other end point of the specified edge contour segment as an end point, thereby obtaining the specified edge contour segment; and filling the interior of the sub-graphic by the piezoelectric inkjet print head;

[0009] Combine all sub-graphics to obtain the target printing image.

[0010] In combination with the first aspect, the coordinate axis includes a first coordinate axis and a second coordinate axis, and the first coordinate axis and the second coordinate axis are perpendicular to each other;

[0011] The step of extracting a specified edge contour line segment from a plurality of edge contour line segments comprises:

[0012] For each edge contour line segment, determining whether the edge contour line segment is parallel to the first coordinate axis or the second coordinate axis;

[0013] If not, the edge contour segment is determined to be the specified edge contour segment.

[0014] In combination with the first aspect, for each sub-image, performing line segment interception on the edge contour of the sub-image to obtain a plurality of edge contour line segments includes:

[0015] For each sub-image, obtain the slope or curvature of each sampling point on the edge contour;

[0016] A line segment consisting of multiple continuous sampling points without sudden changes in slope and curvature is regarded as an edge contour line segment.

[0017] In combination with the first aspect, for each sub-image, after the step of performing line segment interception on the edge contour of the sub-image to obtain a plurality of edge contour line segments, the method further includes:

[0018] Based on the line segment types of the edge contour line segments, multiple edge contour line segments are classified to obtain multiple edge contour line segment collections;

[0019] Determine the printing priority by combining the line segment type, line segment number and line segment length of the edge contour line segments in the plurality of edge contour line segment collections;

[0020] Based on the printing priority, multiple edge contour line segments and corresponding areas inside the sub-image are printed in sequence.

[0021] In conjunction with the first aspect, the line segment types include: curve segments and straight line segments;

[0022] The step of classifying the plurality of edge contour line segments based on the line segment types of the edge contour line segments to obtain a collection of the plurality of edge contour line segments includes:

[0023] If the line segment type is unique and the line segment type is a straight line segment, multiple edge contour line segments are divided into multiple straight line contour line segment sets based on the line segment slope;

[0024] If the line segment type is unique and the line segment type is a curve segment, multiple edge contour line segments are divided into multiple curve contour line segment sets based on the line segment curvature;

[0025] If the line segment type is not unique, all edge contour line segments are preliminarily divided into a collection of straight line contour line segments and a collection of curved contour line segments; based on the slope of each straight line segment in the collection of straight line contour line segments, the collection of straight line contour line segments is further divided into multiple sub-collections of straight line contour line segments; at the same time, based on the curvature of each curved segment in the collection of curved contour line segments, the collection of curved contour line segments is further divided into multiple sub-collections of curved contour line segments.

[0026] In combination with the first aspect, the line segment type is unique; and the steps of determining the printing priority based on the line segment type, the number of line segments, and the length of the line segments include:

[0027] determining a first edge contour line segment collection including a target contour line segment greater than a preset length threshold as a first printing priority;

[0028] determining a second edge contour line segment collection that does not include the target contour line segment as a second priority;

[0029] The first printing priority is higher than the second priority.

[0030] In combination with the first aspect, the line segment type is not unique; the steps of determining the printing priority based on the line segment type, the number of line segments, and the line segment length include:

[0031] Determining a first set of straight contour line segments including a target straight contour line segment having a length greater than a preset threshold as a first printing priority;

[0032] determining a second set of straight contour line segments that does not include the target straight contour line segment as a second priority;

[0033] Determining a first curve contour line segment collection including a target curve contour line segment greater than a preset length threshold as a third priority;

[0034] Determining the second curve contour line segment collection that does not include the target curve contour line segment as a fourth priority;

[0035] The first printing priority is higher than the second priority, the second priority is higher than the third priority, and the third priority is higher than the fourth priority.

[0036] In combination with the first aspect, before the step of acquiring and identifying the expected printing image and obtaining the edge contour corresponding to each sub-image in the expected printing image, the method further includes:

[0037] Get pre-printed 3D models;

[0038] The 3D model is layered to obtain multiple expected printing images.

[0039] In a second aspect, the present application provides a 3D printing device, which is applied to a control unit in a 3D printing system; the 3D printing system also includes a 3D printer, and a piezoelectric inkjet print head of the 3D printer is provided with multiple nozzles; the device includes:

[0040] An acquisition module is used to acquire and identify the expected printing image and obtain the edge contour corresponding to each sub-image in the expected printing image;

[0041] A cutting module is used for cutting the edge contour of each sub-image to obtain a plurality of edge contour line segments;

[0042] An extraction module is used to extract a specified edge contour segment from a plurality of edge contour segments; the specified edge contour segment is an edge contour segment that forms an angle with a coordinate axis in a preset piezoelectric inkjet print head moving coordinate system;

[0043] a control module for controlling the piezoelectric inkjet print head to move along a specified edge contour segment and to activate target nozzles associated with the specified edge contour segment and a corresponding area within the sub-image, so that the target nozzles spray ink toward the area within the sub-image starting from the specified edge contour segment to obtain a sub-image;

[0044] The graphics combination module is used to combine all sub-graphics to obtain the target printing image.

[0045] In a third aspect, the present application provides a 3D printing system, including a control unit. The 3D printing system also includes a 3D printer, which is connected to the control unit. The piezoelectric inkjet print head of the 3D printer is provided with multiple nozzles; ink is sprayed through the nozzles, and the diameter of the ink is greater than the center distance of the injection landing points of the nozzles; the control unit is used to execute the method as described above.

[0046] The embodiments of the present invention bring the following beneficial effects: the 3D printing method, device and system provided by the present application, the 3D printing method is applied to the control unit in the 3D printing system; the method is applied to the control unit in the 3D printing system; the 3D printing system also includes a piezoelectric inkjet print head, and the piezoelectric inkjet print head is provided with multiple nozzles; the piezoelectric inkjet print head is connected to the control unit; the method includes: acquiring and identifying the expected printing image, obtaining the edge contour corresponding to each sub-image in the expected printing image; for each sub-image, performing line segment interception on the edge contour of the sub-image to obtain multiple edge contour line segments; extracting multiple edge contour line segments; A specified edge contour line segment in a contour line segment; the specified edge contour line segment is an edge contour line segment that forms an angle with a coordinate axis in a preset piezoelectric inkjet print head movement coordinate system; the piezoelectric inkjet print head is controlled to move along the specified edge contour line segment, and a target nozzle associated with the specified edge contour line segment is opened, so that the target nozzle takes one end point of the specified edge contour line segment as a starting point and the other end point of the specified edge contour line segment as an end point, and ejects ink along the specified edge contour line segment to obtain the specified edge contour line segment; and, the sub-graphic is filled internally by the piezoelectric inkjet print head; and all the sub-graphics are combined to obtain a target printed image.

[0047] In the present application, after identifying the edge of the graphic, line segments are intercepted based on the edge contour. For each specified edge contour segment, the piezoelectric inkjet print head is controlled to move along the specified edge contour segment and open the target nozzle to spray ink along the specified edge contour segment, so that the ink sprayed by the piezoelectric inkjet print head can form continuous dots on the edge of the graphic, or the dots merge with each other to form continuous lines, thereby fundamentally avoiding the appearance of step lines, improving the smoothness of the printed image and printing efficiency, and thus enhancing the user experience.

[0048] Other features and advantages of the present invention will be described in the following description, and in part will become apparent from the description, or understood by practicing the present invention. The purposes and other advantages of the present invention are realized and obtained by the structures particularly pointed out in the description, claims and drawings.

[0049] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without paying any creative work.

[0051] Figure 1 A schematic diagram of a 3D printing method according to an embodiment of the present invention;

[0052] Figure 2 A schematic diagram of an expected printed image provided by an embodiment of the present invention;

[0053] Figure 3 Based on the 3D printing method provided in the prior art Figure 2 Schematic diagram of the effect after printing;

[0054] Figure 4 The 3D printing method provided by the embodiment of the present invention is Figure 2 A schematic diagram of a printing path for printing;

[0055] Figure 5 Based on Figure 4 A schematic diagram of the printing effect during the printing process of the provided printing path;

[0056] Figure 6 Based on Figure 4 Schematic diagram of the final printing effect of the provided printing path;

[0057] Figure 7 A schematic structural diagram of a 3D printing device provided in an embodiment of the present invention;

[0058] Figure 8 A schematic diagram of the structure of an electronic device provided by an embodiment of the present invention.

[0059] Reference numerals:

[0060] 10-acquisition module, 20-interception module, 30-extraction module, 40-control module, 50-graphic combination module;

[0061] 130 - processor, 131 - memory, 132 - bus, 133 - communication interface. DETAILED DESCRIPTION

[0062] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work shall fall within the scope of protection of the present invention.

[0063] To facilitate understanding of this embodiment, the following is a brief introduction to the technical terms used in this application.

[0064] Inkjet printing converts electronic signals into visible images by spraying ink onto the print medium as needed. This technology offers advantages such as high precision, high speed, and low cost, making it widely used in inkjet printers, 3D printers, label printers, and other fields.

[0065] Piezoelectric materials, which convert electrical energy into mechanical energy, are widely used in inkjet printing heads due to their fast response speed, high displacement accuracy, and excellent stability. Piezoelectric inkjet printheads typically have multiple nozzles, most commonly arranged in a multi-row array. Each nozzle can be independently controlled to spray on demand.

[0066] After introducing the technical terms involved in this application, the application scenarios and design concepts of the embodiments of this application are briefly introduced.

[0067] When existing 3D printers print on curves that are not perpendicular to the X-axis or Y-axis, they will produce step-like textures, resulting in an uneven image surface, affecting the image's aesthetics and limiting the application of inkjet printing technology in areas requiring highly smooth surfaces.

[0068] Based on this, embodiments of the present application provide a 3D printing method, device, and system.

[0069] The 3D printing method provided herein is applied to a control unit in a 3D printing system; the 3D printing system also includes a 3D printer connected to the control unit. It is understood that the control unit can control the 3D printer to execute various printing tasks and adjust the model during the printing process. The piezoelectric inkjet print head of the 3D printer is provided with multiple nozzles.

[0070] Example 1

[0071] Please refer to Figure 1 , Figure 1 This is a flow chart of the 3D printing method provided in this application, which includes:

[0072] S110 , acquiring and identifying an expected printing image, and obtaining edge contours corresponding to each sub-image in the expected printing image.

[0073] S120 , for each sub-image, performing line segment interception on the edge contour of the sub-image to obtain a plurality of edge contour line segments.

[0074] S130 , extracting a designated edge contour line segment from a plurality of edge contour line segments; the designated edge contour line segment is an edge contour line segment that forms an angle with a coordinate axis in a preset piezoelectric inkjet print head movement coordinate system.

[0075] S140, controlling the piezoelectric inkjet print head to move along the specified edge contour segment, and opening the target nozzle associated with the specified edge contour segment, so that the target nozzle takes one end point of the specified edge contour segment as a starting point and the other end point of the specified edge contour segment as an end point, and sprays ink along the specified edge contour segment to obtain the specified edge contour segment; and, filling the interior of the sub-graphic through the piezoelectric inkjet print head.

[0076] S150: Combine all sub-graphics to obtain a target printing image.

[0077] In this application, the edge contour of the image to be printed is identified, and after segment segmentation, the specified edge contour segment is extracted. Then, the piezoelectric inkjet print head is controlled to move along the specified edge contour segment, and the nozzles are opened so that the target nozzles start from one end point of the specified edge contour segment and end at the other end point of the specified edge contour segment, and ink is ejected along the specified edge contour segment. In this way, the effect of ejecting ink from the edge contour to the inner area can be achieved, so that the edge contours of each sub-graphic after printing are complete, clear, and smooth, improving the image aesthetics and user experience.

[0078] There are multiple ways to obtain the expected printing image in step S110. As one feasible way, the expected printing image can be pre-stored by the user on a mobile storage device (such as a USB flash drive, a mobile hard disk, etc.) and connected to the 3D printer through an interface, wireless, Bluetooth, etc. to copy or transmit the expected printing image; as another feasible way, the expected printing image can be downloaded from the cloud; as another feasible way, the expected printing image can also be drawn by the user through software. The above methods are only examples and are not limited here.

[0079] It can be understood that in this embodiment, the expected printed image refers to a planar image. If the initial image obtained is a 3D image, the 3D image can be layered according to actual printing requirements to obtain a multi-layer planar image, and then each layer of the planar image is printed in steps S110-S140 and then combined.

[0080] In addition, each expected print image includes one or more sub-images, and the image types of each sub-image may be different. Please refer to Figure 2The example diagram of the expected printed image provided is shown. It can be seen that the expected printed image includes a triangular sub-image and a circular sub-image. In the prior art, the printing of images is mainly achieved by controlling the relative movement and spraying of the print head and the print nozzle. During the printing process, the inkjet print head and the printing platform move relative to each other in at least two of the three directions of X, Y, and Z. A common method is that the print head usually moves relative to the printing platform along the X direction or the Y direction, and during this process, it sprays on demand according to the shape of the graphic. The computer will cut the graphic into many small grids according to the pixel settings in the X and Y directions. Combined with the above examples, for Figure 2 The two sub-images in the expected printed image shown in the prior art are arranged in the X and Y directions (corresponding to Figure 2 The pixel grid is cut in the length direction and width direction of the image, but each nozzle of the nozzle can only eject at least 1 drop of ink, and cannot eject 0.5 drops or 0.3 drops of ink. Therefore, each pixel grid either ejects ink or does not eject ink. The nozzle determines whether to eject ink based on whether there is a pattern in the small grid. If there is a pattern and it exceeds 50%, ink dots are ejected. If there is no pattern or it is less than 50%, no ink dots are ejected. Figure 3 As shown. In this way, when printing the contour line, it will cause the pixels on the contour to be missing or over-printed, resulting in an uneven image surface and uneven edge contour. Among them, the sub-graphic in step S140 is the sub-image currently being printed.

[0081] In step S110, edge recognition is performed on the intended printed image using an image processing algorithm to determine the edge contours of each sub-image. For example, edge detection operators such as the Sobel operator and the Prewitt operator can be used to perform edge detection on the image and extract the edge contours of the graphics.

[0082] In combination with the first aspect, the coordinate axis includes a first coordinate axis and a second coordinate axis, and the first coordinate axis and the second coordinate axis are perpendicular to each other. That is, the X axis and Y axis mentioned above. Step S130 includes:

[0083] S131 : For each edge contour line segment, determine whether the edge contour line segment is parallel to the first coordinate axis or the second coordinate axis.

[0084] If not, go to step S132; if so, go to step S133.

[0085] S132: Determine that the edge contour line segment is a designated edge contour line segment.

[0086] S133: Determine whether the edge contour line segment is a non-specified edge contour line segment.

[0087] In this embodiment, an edge contour line that is not parallel to the first coordinate axis (i.e., the aforementioned X-axis) or the second coordinate axis (i.e., the aforementioned Y-axis) is predefined as a designated edge contour line segment. That is, if the designated edge contour line is not parallel to either the X-axis or the Y-axis, then the designated edge contour line should form an angle with both the X-axis and the Y-axis.

[0088] After step S130, 3D printing is performed for each designated edge contour segment. During the 3D printing process, the corresponding target nozzle ejects ink along the designated edge contour segment, starting from one end and ending at the other end. This achieves smooth printing of the designated edge contour segment, improving the smoothness of the printed lines and the aesthetics of the image.

[0089] As an operative approach, for any print point on a specified edge contour segment, ink is ejected from that point as the ink exit point. By adjusting the operating power of the nozzles to increase the ink ejection stroke, ink is ejected from that point as the ink exit point and toward the interior of the sub-pattern. Therefore, as the piezoelectric inkjet print head moves along the specified edge contour segment, it prints multiple consecutive print points on the specified edge contour segment, thereby achieving printing of the specified edge contour segment and a portion of the interior of the sub-pattern.

[0090] As another feasible method, it is also possible to preferentially print a plurality of designated edge contour line segments and then fill the interior of the sub-graphics.

[0091] As another feasible method, the inner area of ​​the sub-graphic may be printed first, and then the designated edge contour line segments may be printed multiple times.

[0092] The above methods are all feasible and can be set according to the actual graphics and printing requirements, and are not limited here. It can be understood that printing the specified edge contour line segment and the internal area at the same time can shorten the printing time and improve work efficiency while improving the smoothness of the edge contour compared to other methods.

[0093] Step S120 includes:

[0094] S1201 : For each sub-image, obtain the slope or curvature of each sampling point on the edge contour.

[0095] S1202: A line segment consisting of a plurality of continuous sampling points without sudden changes in slope and curvature is used as an edge contour line segment.

[0096] In this embodiment, the edge contour of the sub-image is intercepted based on the slope or curvature of the sampling points to obtain multiple edge contour segments. The curvature or slope of multiple consecutive sampling points on each edge contour segment is consistent. If the curvature of each sampling point on the edge contour segment is consistent, the intercepted edge contour segment is a curved segment; if the slope of each sampling point on the edge contour segment is consistent, the intercepted edge contour segment is an oblique line segment.

[0097] It can be understood that after the edge contour is segmented to obtain multiple edge contour segments, 3D printing can be performed in sequence according to the preset printing order until all edge contour segments are printed, thereby obtaining a sub-image with a complete, continuous and smooth edge contour line.

[0098] In combination with the first aspect, after step S120, the method further includes:

[0099] S121 , classifying a plurality of edge contour line segments based on the line segment types of the edge contour line segments to obtain a plurality of edge contour line segment collections.

[0100] S122 , determining a printing priority based on the segment type, number of segments, and length of the edge contour segments in the plurality of edge contour segment collections.

[0101] S123 , based on the printing priority, sequentially printing the plurality of edge contour line segments and the corresponding areas inside the sub-image.

[0102] In this embodiment, printing priority is determined based on the classification of multiple edge contour segments, taking into account segment type, number of segments, and segment length. After determining the printing priority, this is used as a printing rule for 3D printing. This clustered printing method improves printing efficiency.

[0103] Wherein, the line segment types include curve segments and straight line segments. Step S121 includes:

[0104] S121A: If the line segment type is unique and the line segment type is a straight line segment, divide the plurality of edge contour line segments into a plurality of straight line contour line segment sets based on the line segment slopes;

[0105] S121B: If the line segment type is unique and the line segment type is a curve segment, divide the multiple edge contour line segments into multiple curve contour line segment sets based on the line segment curvature;

[0106] S121C, if the line segment type is not unique, preliminarily divide all edge contour line segments into a collection of straight line contour line segments and a collection of curved contour line segments; based on the slope of each straight line segment in the collection of straight line contour line segments, further divide the collection of straight line contour line segments into multiple sub-collections of straight line contour line segments; at the same time, based on the curvature of each curved segment in the collection of curved contour line segments, further divide the collection of curved contour line segments into multiple sub-collections of curved contour line segments.

[0107] It can be understood that the line segment type is a straight line segment or a curve segment. First, the line segment types of all intercepted edge contour line segments are divided, and then further divided in combination with the line segment slope or line segment curvature.

[0108] If step S121A is performed only for straight segments, segmentation is performed based on segment slopes, resulting in a collection of multiple straight contour segments with different segment slopes, with the straight contour segments in each collection having the same slope. Similarly, if step S121B is performed only for curved segments, segmentation is performed based on segment curvature, resulting in a collection of multiple curved contour segments with different segment curvatures, with the curved contour segments in each collection having the same curvature.

[0109] For the complex situation where the line segment type is not unique, a preliminary division is first performed according to the line segment type, and then steps S121A and S121B are further performed to complete the clustering process.

[0110] In this embodiment, by clustering the line segments and then planning the printing priority according to the results of the clustering, different target contour line segment collections can be printed in batches. Compared with the situation of sequential printing that constantly switches between straight paths and curved paths, the operating stability is improved, and printing similar contour line segments at one time is conducive to improving printing efficiency.

[0111] In combination with the first aspect, when the line segment type is unique, step S122 includes:

[0112] S12211: Determine a first edge contour line segment collection including target contour line segments greater than a preset length threshold as a first printing priority.

[0113] S12212: Determine the second edge contour line segment set that does not include the target contour line segment as a second priority.

[0114] The first printing priority is higher than the second priority.

[0115] It can be understood that in the case where all are contour straight line segments or all are contour curve segments, the priority is determined based on the segment length first, and the first edge contour segment collection containing target contour segments greater than the preset length threshold is printed first, and then the second edge contour segment collection is printed.

[0116] Since the number of first edge contour line segment collections and second edge contour line segment collections may not be one, it is preferable to further sort the first priority level by descending the number of target contour line segments in the first edge contour line segment collections. Similarly, the second priority level can be further sorted by descending the number of contour line segments in the second edge contour line segment collections. This allows for careful planning of the printing order and improved printing efficiency.

[0117] For example, suppose the linear contour segment collections are A, B, C, D, ..., and G. Among them, the edge contour segment collections A, C, E, and F contain target contour segments whose linear segment lengths are greater than a preset length threshold. A contains 10 target contour segments, C contains 3, E contains 5, and F contains 8. In this case, for the multiple first linear contour segment collections, the printing priority order is: A, F, E, C. In the second linear contour segment collections B, D, and G, B contains 15 segments, D contains 3 segments, and G contains 6 segments. In this case, the printing order of these second linear contour segment collections is: B, G, D.

[0118] In combination with the above example, the target printing priority of the above-mentioned collection of straight contour line segments is: AFECBGD.

[0119] In combination with the first aspect, the line segment type is not unique; step S122 includes:

[0120] S12221: Determine a first set of straight contour line segments including target straight contour line segments greater than a preset length threshold as a first printing priority.

[0121] S12222: Determine the second straight contour segment set that does not include the target straight contour segment as a second priority.

[0122] S12223: Determine the first curve contour line segment collection including the target curve contour line segment greater than a preset length threshold as a third printing priority.

[0123] S12223: Determine the second curve contour line segment collection that does not include the target curve contour line segment as a fourth priority.

[0124] The first printing priority is higher than the second priority, the second priority is higher than the third priority, and the third priority is higher than the fourth priority.

[0125] It is understandable that when the line segment type is not unique, the printing priority is determined as follows: print straight lines first, then curves. When printing straight lines or curves, the printing priority is further refined in a manner similar to steps S12211-S12212.

[0126] In combination with the above example, based on the existence of a set of straight contour segments A, B, C, D...G, there is also a set of curved contour segments H, I, J...O.

[0127] The curve contour line segment collections are I, J, L, N, and O, respectively, and contain target contour line segments whose curve segment lengths exceed a preset length threshold. I contains three target contour line segments, J contains five, L contains one, N contains seven, and O contains two. The printing priority order for these first curve contour line segment collections is: N, J, I, O, L. For the second curve contour line segment collections H, K, and M, H contains six segments, K contains three, and M contains 17 segments. The printing order for these second curve contour line segment collections is: M, H, K.

[0128] At this time, the printing priority order of the above-mentioned curve contour line segment collections is: NJIOLMHK.

[0129] Combined with the above example, the target printing priority order is: AFECBGDNJIOLMHK.

[0130] It is understandable that different length thresholds may be selected for different industries, and the length thresholds corresponding to straight segments and curved segments may also be different. Typically, the length threshold value ranges from 5 cm to 15 cm.

[0131] Among them, during the printing process, different nozzles of the piezoelectric inkjet print head are allocated to be responsible for the spraying in different sections according to the shape contour of the sub-image, and the movement process is coordinated at the same time. When moving along the same or similar motion trajectory, multiple nozzles spray (simultaneously or not according to the actual working conditions) to print the corresponding contour lines and internal areas of the level.

[0132] Please refer to Figure 4 , Figure 4 The 3D printing method provided for this application is based on Figure 2 Provides an example of the printing path for printing the expected print image. Figure 2 In the case of straight line segments and curved line segments, the edge contour segments of the straight line segments are printed first, and then the edge contour segments of the curved line segments are printed. According to the determined printing priority, the path is planned. Combined with the two sub-images, the first priority path 1 is planned for printing the hypotenuse of the triangle (combined with Figure 4 The blue line in the middle triangle) and the straight line segments parallel to the hypotenuse, combined with Figure 4As shown, the piezoelectric inkjet print head moves from position 1 to position 2 along path 1, and in this process, uses nozzle 10 and nozzle 346 to complete the printing of an oblique outline in the triangular sub-graphic and an oblique line segment in the circular sub-graphic (combined with the blue line on the left side of the circular ring). The piezoelectric inkjet print head is moved to position 3 in path 1 again, and starts to spray with nozzle 543. It moves from position 3 to position 4 along path 1, and completes the printing of the third oblique line segment (combined with the blue line on the right side of the circular ring) in this process. In the process of the current nozzle moving along the hypotenuse of the triangle to spray ink, other nozzles can spray at the same time to complete the injection filling inside the sub-graphic. Please refer to the position after filling. Figure 5 As shown. The piezoelectric inkjet print head continues to move along path 2 and path 3 respectively, and sprays the filling pattern at different nozzles in the process. When path 3 is completed, the triangle pattern is printed. The edge outline of the circular pattern is printed along path 4. After all paths are moved, the pattern printing effect is as shown. Figure 6 When the graphics are more complex and varied, smaller sections can be allocated and more nozzles can be used to print them.

[0133] While the piezoelectric nozzles are ejecting according to the aforementioned path motion process, the nozzle jetting frequency and the nozzle's movement speed relative to the print platform are controlled to precisely control the center-to-center distance between the ink droplets, thereby achieving the fusion of two adjacent ink droplets to form a continuous line. For example, using a 6-picoliter nozzle, a controlled jetting frequency of 28 kHz, a nozzle printing resolution of 1440 DPI, and a relative movement speed of approximately 490 mm / s between the nozzles, the center-to-center distance between the jet droplets can be calculated to be 18 microns. In theory, the ink droplets ejected onto the print surface are hemispherical. Taking into account the diffusion of the ink droplets, the diameter of the ink droplets is generally 25-30 microns. Under these conditions, the ink droplets fuse together to form continuous lines, and the lines are distributed according to the contours of the pattern, forming a smooth surface.

[0134] In combination with the first aspect, before step S110, the method further includes:

[0135] S100: Obtain a pre-printed 3D model.

[0136] S101, performing layer processing on the 3D model to obtain a plurality of expected printing images.

[0137] Specifically, when printing a 3D model, the 3D model can be layered to obtain multiple desired print images. Then, steps S110-S140 are performed on each desired print image to perform image recognition, contour segment extraction, classification, target print path planning, and target nozzle orifice determination before printing. This yields a target image corresponding to each layered desired print image after 3D printing. Subsequently, the multiple target images are combined to obtain a target 3D model corresponding to the pre-printed 3D model.

[0138] It is understandable that there are many ways to obtain the 3D model and the expected printing image, which are not limited here.

[0139] In a second aspect, the present application provides a 3D printing device, which is applied to a control unit in a 3D printing system; the 3D printing system also includes a 3D printer, which is connected to the control unit, and a piezoelectric inkjet print head in the 3D printer is provided with multiple nozzles, which correspond one to one to multiple spray areas. Figure 7 As shown, the device includes: an acquisition module 10, a capture module 20, an extraction module 30, a control module 40 and a graphic combination module 50.

[0140] The acquisition module 10 is used to acquire and identify the expected printing image, and obtain the edge contour corresponding to each sub-image in the expected printing image.

[0141] The interception module 20 is used for performing line segment interception on the edge contour of each sub-image to obtain a plurality of edge contour line segments.

[0142] The extraction module 30 is used to extract a specified edge contour segment from a plurality of edge contour segments; the specified edge contour segment is an edge contour segment that forms an angle with a coordinate axis in a preset piezoelectric inkjet print head movement coordinate system.

[0143] The control module 40 is used to control the piezoelectric inkjet print head to move along the specified edge contour segment and open the target nozzles associated with the specified edge contour segment and the corresponding area inside the sub-image, so that the target nozzles use the specified edge contour segment as the starting point to spray ink into the internal area of ​​the sub-image to obtain a sub-graphic.

[0144] The graphic combination module 50 is used to combine all sub-graphics to obtain a target printing image.

[0145] In a third aspect, the present application provides a 3D printing system, including a control unit. The 3D printing system also includes a 3D printer, which is connected to the control unit. The piezoelectric inkjet print head of the 3D printer is provided with multiple nozzles; ink is sprayed through the nozzles, and the diameter of the ink is greater than the center distance of the injection landing points of the nozzles; the control unit is used to execute the method as described above.

[0146] In a fourth aspect, the present application provides an electronic device, Figure 8 As shown, the electronic device includes a memory 131 and a processor 130. The memory 131 is used to store computer programs, and the processor 130 runs the computer programs to enable the electronic device to perform the above method.

[0147] Further, combined with Figure 8The electronic device shown further includes a bus 132 and a communication interface 133 , and the processor 130 , the communication interface 133 and the memory 131 are connected via the bus 132 .

[0148] The memory 131 may include a high-speed random access memory (RAM), and may also include a non-volatile memory, such as at least one disk storage. The communication connection between the system network element and at least one other network element is achieved through at least one communication interface 133 (which may be wired or wireless), and the Internet, wide area network, local area network, metropolitan area network, etc. may be used. The bus 132 may be an ISA bus, a PCI bus, or an EISA bus. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 8 Only one bidirectional arrow is used in the diagram, but this does not mean that there is only one bus or one type of bus.

[0149] The processor 130 may be an integrated circuit chip with signal processing capabilities. During implementation, each step of the above method can be completed by hardware integrated logic circuits in the processor 130 or by software instructions. The processor 130 may be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it may also be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. It can implement or execute the various methods, steps, and logic block diagrams disclosed in the embodiments of the present invention. The general-purpose processor may be a microprocessor or any conventional processor. The steps of the method disclosed in conjunction with the embodiments of the present invention can be directly implemented and executed by a hardware decoding processor, or by a combination of hardware and software modules in the decoding processor. The software module can be located in a storage medium well-known in the art, such as random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, etc. The storage medium is located in memory 131, and processor 130 reads information in memory 131 and, in conjunction with its hardware, completes the steps of the method of the aforementioned embodiment.

[0150] In a fourth aspect, an embodiment of the present application provides a readable storage medium, in which computer program instructions are stored. When the computer program instructions are read and executed by a processor, the above-mentioned method is executed.

[0151] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the above-described systems and devices can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0152] In addition, in the description of the embodiments of the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to mechanical connections or electrical connections; they may refer to direct connections or indirect connections through an intermediate medium; and they may refer to internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0153] If the function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the various embodiments of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, and other media that can store program code.

[0154] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0155] Finally, it should be noted that the above embodiments are only specific implementation methods of the present invention, which are used to illustrate the technical solutions of the present invention, rather than to limit them. The scope of protection of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that any person skilled in the art can modify or easily conceive of changes to the technical solutions described in the above embodiments within the technical scope disclosed by the present invention, or replace some of the technical features therein with equivalents. Such modifications, changes or replacements do not deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A 3D printing method, characterized in that: The method is applied to a control unit in a 3D printing system; the 3D printing system further comprises a 3D printer, the 3D printer being connected to the control unit; a piezoelectric inkjet print head of the 3D printer is provided with a plurality of nozzles; The piezoelectric inkjet print head is connected to the control unit; the method comprises: Acquire and identify the expected printing image, and obtain the edge contour corresponding to each sub-image in the expected printing image; For each of the sub-images, performing line segment interception on the edge contour of the sub-image to obtain a plurality of edge contour line segments; Extracting a specified edge contour line segment from the plurality of edge contour line segments; the specified edge contour line segment is an edge contour line segment that forms an angle with a coordinate axis in a preset coordinate system for movement of the piezoelectric inkjet print head; Controlling the piezoelectric inkjet print head to move along the designated edge contour segment and opening target nozzles associated with the designated edge contour segment so that the target nozzles eject ink along the designated edge contour segment with one end point of the designated edge contour segment as a starting point and the other end point of the designated edge contour segment as an end point, thereby obtaining the designated edge contour segment; and filling the interior of the sub-graphic by the piezoelectric inkjet print head; All of the sub-graphics are combined to obtain a target printing image.

2. The method according to claim 1, characterized in that The coordinate axis includes a first coordinate axis and a second coordinate axis, and the first coordinate axis and the second coordinate axis are perpendicular to each other; The step of extracting a specified edge contour line segment from the plurality of edge contour line segments comprises: For each edge contour line segment, determining whether the edge contour line segment is parallel to the first coordinate axis or the second coordinate axis; If not, the edge contour segment is determined to be the designated edge contour segment.

3. The method according to claim 1, characterized in that For each of the sub-images, performing line segment interception on the edge contour of the sub-image to obtain a plurality of edge contour line segments includes: For each of the sub-images, obtaining the slope or curvature of each sampling point on the edge contour; A line segment consisting of a plurality of continuous sampling points without sudden changes in slope and curvature is used as the edge contour line segment.

4. The method according to claim 1, wherein For each of the sub-images, after performing line segment interception on the edge contour of the sub-image to obtain a plurality of edge contour line segments, the method further includes: Classifying the plurality of edge contour line segments based on the line segment types of the edge contour line segments to obtain a plurality of edge contour line segment collections; Determining a printing priority based on the segment type, number of segments, and length of the edge contour segments in the plurality of edge contour segment collections; Based on the printing priority, a plurality of edge contour line segments and corresponding areas inside the sub-image are printed in sequence.

5. The method according to claim 4, characterized in that The line segment types include: curve segments and straight line segments; The step of classifying the plurality of edge contour line segments based on the line segment types of the edge contour line segments to obtain a plurality of edge contour line segment collections includes: If the line segment type is unique and the line segment type is a straight line segment, the plurality of edge contour line segments are divided into a plurality of straight line contour line segment sets based on the line segment slopes; If the line segment type is unique and the line segment type is a curve segment, dividing the plurality of edge contour line segments into a plurality of curve contour line segment sets based on the line segment curvature; If the line segment type is not unique, all edge contour line segments are preliminarily divided into a collection of straight line contour line segments and a collection of curved contour line segments; based on the slope of each straight line segment in the collection of straight line contour line segments, the collection of straight line contour line segments is further divided into a plurality of sub-straight line contour line segment collections; at the same time, based on the curvature of each curved segment in the collection of curved contour line segments, the collection of curved contour line segments is further divided into a plurality of sub-curved contour line segment collections.

6. The method according to claim 5, characterized in that The line segment type is unique; and the step of determining the printing priority based on the line segment type, the number of line segments, and the length of the line segments comprises: determining a first edge contour line segment collection including a target contour line segment greater than a preset length threshold as a first printing priority; determining a second edge contour line segment collection that does not include the target contour line segment as a second priority; The first printing priority is higher than the second priority.

7. The method according to claim 5, characterized in that The line segment type is not unique; the step of determining the printing priority based on the line segment type, the number of line segments, and the length of the line segments includes: Determining a first set of straight contour line segments including a target straight contour line segment having a length greater than a preset threshold as a first printing priority; determining a second set of straight contour line segments that does not include the target straight contour line segment as a second priority; Determining a first curve contour line segment collection including a target curve contour line segment greater than a preset length threshold as a third priority; determining a second curve contour line segment collection that does not include the target curve contour line segment as a fourth priority; The first printing priority is higher than the second priority, the second priority is higher than the third priority, and the third priority is higher than the fourth priority.

8. The method according to claim 1, characterized in that Before the step of acquiring and identifying the expected printing image and obtaining the edge contour corresponding to each sub-image in the expected printing image, the method further includes: Get pre-printed 3D models; The 3D model is layered to obtain a plurality of the expected printing images.

9. A 3D printing device, characterized in that: A control unit used in a 3D printing system; the 3D printing system also includes a 3D printer, and the piezoelectric inkjet print head of the 3D printer is provided with multiple nozzles; the device includes: An acquisition module is used to acquire and identify the expected printing image and obtain the edge contour corresponding to each sub-image in the expected printing image; a cutting module, configured to cut off the edge contour of each sub-image by line segments, to obtain a plurality of edge contour line segments; an extraction module, configured to extract a specified edge contour line segment from the plurality of edge contour line segments; the specified edge contour line segment is an edge contour line segment that forms an angle with a coordinate axis in a preset coordinate system for movement of the piezoelectric inkjet print head; a control module, configured to control the piezoelectric inkjet print head to move along the designated edge contour segment and to activate target nozzles associated with the designated edge contour segment and a corresponding area within the sub-image, so that the target nozzles spray ink toward the area within the sub-image starting from the designated edge contour segment to obtain a sub-graphic; The graphic combination module is used to combine all the sub-graphics to obtain a target printing image.

10. A 3D printing system, characterized in that: The 3D printing system includes a control unit, and the 3D printer is connected to the control unit. The piezoelectric inkjet print head of the 3D printer is provided with multiple nozzles; ink is ejected through the nozzles, and the diameter of the ink is greater than the center distance of the injection landing points of the nozzles; the control unit is used to execute the method according to any one of claims 1 to 8.

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