3D printing method, device and system

Abstract

The invention relates to the technical field of 3D printing, in particular to a 3D printing method, device and system, and the 3D printing method is applied to a control unit in the 3D printing system. The method is applied to a control unit in the 3D printing system. The 3D printing system further comprises a piezoelectric ink-jet printing head, and a plurality of spraying holes are formed in the piezoelectric ink-jet printing head. According to the method and the device, line segment interception is performed based on the edge contour after the image edge is identified, and for each specified edge contour line segment, a piezoelectric ink-jet printing head is controlled to move along the specified edge contour line segment and a target spray hole is opened, so that ink is jetted along the specified edge contour line segment; according to the technical scheme, the piezoelectric ink-jet printing head is arranged, so that ink sprayed by the piezoelectric ink-jet printing head can form continuous points on the edge of a graph, or the points are fused to form continuous lines, the occurrence of step lines is fundamentally avoided, the smoothness and the printing efficiency of a printed image are improved, and the use experience of a user is improved.

Description

Technical Field

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

[0002] Existing inkjet printing technology mainly realizes image printing by controlling the relative movement and spraying between the printing platform and the inkjet print head. 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 sprays on demand according to the shape of the graphics during this process. The computer will cut the graphics into many small grids according to the pixel settings in the XY direction, but each nozzle of the nozzle can only spray at least 1 drop of ink, and cannot spray 0.5 drops or 0.3 drops of ink. Therefore, the pixel grid either sprays ink or does not spray ink. The nozzle determines whether to spray according to whether there is a graphic in the small grid. If there is a graphic, the ink point is sprayed, and if there is no graphic, the ink point is not sprayed. This printing method will produce step-like textures on curves that are not perpendicular to the X-axis or Y-axis, resulting in an uneven image surface.

[0003] When printing on a curve that is not perpendicular to the X-axis or Y-axis, existing inkjet printing technology will produce step-like textures, resulting in an uneven image surface. This not only affects the aesthetics of the image, but also limits the application of inkjet printing technology on surfaces that require high smoothness. Therefore, how to improve inkjet printing technology and improve the surface smoothness and printing quality of printed images is an urgent problem to be solved in the current technical 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, and the 3D printer is 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:

[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 a plurality of 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 moving coordinate system;

[0008] Controlling the piezoelectric inkjet print head to move along the specified edge contour line segment, and opening the target nozzle associated with the specified edge contour line segment, 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 sprays ink along the specified edge contour line segment to obtain the specified edge contour line segment; and filling the sub-graphic internally through the piezoelectric inkjet print head;

[0009] Combine all sub-graphics to get 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 a 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 taken 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, the number of line segments and the 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: a curve segment and a straight line segment;

[0022] The step of classifying the plurality of edge contour line segments based on the line segment type of the edge contour line segments to obtain a plurality of edge contour line segment collections 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 slopes;

[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 a plurality of 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 a plurality of sub-collections of curved contour line segments.

[0026] In combination with the first aspect, the line segment type is unique; and the step of determining the printing priority in combination with the line segment type, the number of line segments, and the length of the line segments includes:

[0027] Determine 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] Determine the second edge contour line segment collection that does not include the target contour line segment as a second priority;

[0029] Among them, the first printing priority is higher than the second priority.

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

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

[0032] Determine a second straight contour segment collection that does not include the target straight contour segment as a second priority;

[0033] Determine the first curve contour line segment collection including the 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] Among them, 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 contours 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 processed in layers 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 a plurality of 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 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 moving coordinate system;

[0043] A control module is used to control the piezoelectric inkjet print head to move along the specified edge contour line segment, and to open the target nozzles associated with the specified edge contour line segment and the corresponding area inside the sub-image, so that the target nozzles take the specified edge contour line segment as a starting point and spray ink to the inner area of ​​the sub-image to obtain a sub-graphic;

[0044] The graphics combination module is used to combine all sub-graphics to obtain a 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, the 3D printer is connected to the control unit, and a plurality of nozzles are arranged on the piezoelectric inkjet print head of the 3D printer; ink is sprayed through the nozzles, and the diameter of the ink is larger 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 a control unit in a 3D printing system; the method is applied to a control unit in a 3D printing system; the 3D printing system also includes a piezoelectric inkjet print head, and a plurality of nozzles are arranged on the piezoelectric inkjet print head; the piezoelectric inkjet print head is connected to the control unit; the method includes: acquiring and identifying an expected printed image, and obtaining edge contours corresponding to each sub-image in the expected printed image; 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; extracting a plurality of edge 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 moving 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 ink is sprayed 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 the edge of the graphic is identified, the line segment is 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 partly become apparent from the description, or understood by practicing the present invention. The purpose 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 implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods 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 A schematic diagram of the final printing effect of the provided printing path;

[0057] Figure 7 A schematic diagram of the structure 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] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0063] In order to facilitate the understanding of this embodiment, the technical terms designed in this application are briefly introduced below.

[0064] Inkjet printing technology is a technology that converts electronic signals into visible images. It forms images by spraying ink onto the printing medium as needed. This technology has the advantages of high precision, high speed and low cost, and is widely used in inkjet printers, 3D printers, label printers and other fields.

[0065] Piezoelectric materials are materials that can convert electrical energy into mechanical energy. They are widely used in print heads of inkjet printing technology because of their fast response speed, high displacement accuracy, and good stability. Piezoelectric inkjet print heads generally have multiple nozzles. Currently, the nozzles of piezoelectric inkjet print heads are mostly arranged in a multi-row nozzle array, and 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 aesthetics of the image and limiting the application of inkjet printing technology in areas that require 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 in the present application 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. It can be understood that the control unit can control the 3D printer to perform different printing tasks and adjust the model during the printing task. The piezoelectric inkjet print head of the 3D printer is provided with a plurality of nozzles.

[0070] Example 1

[0071] Please refer to Figure 1 , Figure 1 A flow chart of the 3D printing method provided in this application, the method comprising:

[0072] S110, acquiring and identifying the 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 the starting point and the other end point of the specified edge contour segment as the end point, and sprays ink along the specified edge contour segment to obtain the specified edge contour segment; and, filling the sub-graphic internally through the piezoelectric inkjet print head.

[0076] S150, combining all sub-graphics to obtain a target printing image.

[0077] In the present application, the edge contour of the image to be printed is recognized, the line segment is intercepted, and then the designated edge contour line segment is extracted. Then, the piezoelectric inkjet print head is controlled to move along the designated edge contour line segment, and the nozzle is opened so that the target nozzle takes one end point of the designated edge contour line segment as the starting point and the other end point of the designated edge contour line segment as the end point, and ink is sprayed along the designated edge contour line segment. In this way, the effect of spraying ink from the edge contour to the internal area can be achieved, so that the edge contour of each sub-graphic after printing is complete, clear, and smooth, which improves 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 in a mobile storage device (such as a USB flash drive, a mobile hard disk, etc.) and communicated with 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 plane 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 plane image, and then each layer of the plane 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 as shown shows 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 sprays on demand according to the shape of the graphic during this process. 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 In the two sub-images of the expected printed image shown in the prior art, 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 according to 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 expected printed image by an image processing algorithm to determine the edge contour of each sub-image. For example, an edge detection operator such as a Sobel operator or a Prewitt operator may be used to perform edge detection on the image to extract the edge contour of the image.

[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 the 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, execute step S132; if so, execute step S133.

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

[0086] S133, determining that the edge contour line segment is not a designated edge contour line segment.

[0087] In this embodiment, an edge contour line that is not parallel to the first coordinate axis (i.e., the X axis) or the second coordinate axis (i.e., the Y axis) is predefined as a designated edge contour line segment. That is, the designated edge contour line is not parallel to the X axis and is not parallel to the Y axis, so 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 line segment. During the 3D printing process, the corresponding target nozzle takes one end of the designated edge contour line segment as the starting point and the other end as the end point, and sprays ink along the designated edge contour line segment, thereby achieving smooth printing of the designated edge contour line segment, improving the smoothness of the printed lines and the aesthetics of the image.

[0089] As an implementable method, for any printing point of the specified edge contour line segment, the direction of ink jetting is to use the point as the ink outlet point, and by adjusting the operating power of the nozzle to increase the ink jetting stroke of the nozzle, for any printing point of the specified edge contour line segment, the direction of ink jetting is to use the point as the ink outlet point and jet toward the inner area of ​​the sub-graphic. Therefore, as the piezoelectric inkjet print head moves along the specified edge contour line segment, multiple continuous printing points on the specified edge contour line segment are printed, thereby realizing printing of the specified edge contour line segment and a partial area inside the sub-graphic.

[0090] As another feasible method, a plurality of designated edge contour line segments may be printed first and then the sub-graphics may be filled internally.

[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 practicable and can be set according to 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, obtaining the slope or curvature of each sampling point on the edge contour.

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

[0096] In this embodiment, the edge contour of the sub-image is intercepted according to the slope or curvature of the sampling points to obtain multiple edge contour line segments, and the curvature or slope of multiple consecutive sampling points on each edge contour line segment is consistent. If the curvatures of the sampling points on the edge contour line segment are consistent, then the intercepted edge contour line segment is a curved line segment; if the slopes of the sampling points on the edge contour line segment are consistent, then the intercepted edge contour line 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 a preset printing order until all edge contour segments are printed to obtain 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, the number of segments, and the segment length of the edge contour segments in the plurality of edge contour segment collections.

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

[0102] In this embodiment, the printing priority is determined based on the classification of multiple edge contour line segments and in combination with the line segment type, the number of line segments and the line segment length. After the printing priority is determined, it is used as a printing rule to perform 3D printing. In this way, cluster printing is conducive to improving printing efficiency.

[0103] 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 plurality of edge contour line segments into a plurality of curve contour line segment sets based on the line segment curvature;

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

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

[0108] Wherein, if step S121A is performed only for straight segments, the segmentation is performed based on the segment slope to obtain a plurality of straight contour line segment collections with different line segment slopes, and the straight contour line segments in each straight contour line segment collection have the same slope. Similarly, if step S121B is performed only for curved segments, the segmentation is performed based on the segment curvature to obtain a plurality of curved contour line segment collections with different line segment curvatures, and the curved contour line segments in each curved contour line segment collection have 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 path and curve path, the operation 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 collection that does not include the target contour line segment as a second priority.

[0114] Among them, 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 the first edge contour line segment collection and the second edge contour line segment collection may not be one, preferably, the target contour line segments in the plurality of first edge contour line segment collections may be further sorted in descending order to refine the first priority; similarly, the contour line segments in the plurality of second edge contour line segment collections may be further sorted in descending order to refine the second priority, so as to carefully plan the printing order and improve the printing efficiency.

[0117] For example, the straight contour line segment collections are A, B, C, D...G, wherein the edge contour line segment collections A, C, E, F contain target contour line segments whose straight line segment length is greater than a preset length threshold, wherein the number of target contour line segments in A is 10, the number of target contour line segments in C is 3, the number of target contour line segments in E is 5, and the number of target contour line segments in F is 8. At this time, for the first straight contour line segment collections, the printing priority order is: A, F, E, C. In the second straight contour line segment collections B, D, G, the number of line segments of B is 15, the number of line segments of D is 3, and the number of selected segments of G is 6. At this time, the printing order of each second straight contour line segment collection is: B, G, D.

[0118] In combination with the above example, the target printing priority of the above-mentioned collection of straight contour 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 line contour line segments including target straight line contour line segments greater than a preset length threshold as a first printing priority.

[0121] S12222: Determine a second straight line contour segment collection that does not include the target straight line 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] Among them, 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 can be understood that when the line segment type is not unique, the rule for determining the printing priority is: print the straight line first, then print the curve, and further refine the printing priority in a manner similar to steps S12211-S12212 when printing the straight line or printing the curve.

[0126] In combination with the above example, on the basis that there are a collection of straight contour segments A, B, C, D...G respectively, there are also a collection of curved contour segments H, I, J...O respectively.

[0127] Among them, the curve contour line segment collections are target contour line segments with curve segment lengths greater than a preset length threshold in I, J, L, N, and O, respectively, wherein the number of target contour line segments in I is 3, the number of target contour line segments in J is 5, the number of target contour line segments in L is 1, the number of target contour line segments in N is 7, and the number of target contour line segments in O is 2. At this time, for multiple first curve contour line segment collections, the printing priority order is: N, J, I, O, L. Among the second curve contour line segment collections H, K, and M, the number of line segments in H is 6, the number of line segments in K is 3, and the number of selected segments in M ​​is 17. At this time, the printing order of each second curve contour line segment collection 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 according to the shape contour of the sub-image to be responsible for the spraying in different sections respectively, 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 print path for printing the intended print image. Figure 2 , in the case of straight line segments and curved line segments, the edge contour line segments of the straight line segment type are printed first, and then the edge contour line segments of the curved line segment type are printed. According to the determined printing priority, the path is planned, and the first priority path 1 is planned to print the hypotenuse of the triangle (combined with Figure 4 The blue line in the middle triangle) and the straight lines 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 the 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), and the piezoelectric inkjet print head is moved to position 3 in path 1 again, and starts to spray with nozzle 543, and moves from position 3 to position 4 along path 1. In this process, the printing of the third oblique line segment (combined with the blue line on the right side of the circular ring) is completed. 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 middle. When path 3 is completed, the triangular pattern is printed. The edge contour 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 for jet printing.

[0133] While the piezoelectric nozzle is spraying according to the above path movement process, the nozzle spraying frequency and the movement speed of the nozzle relative to the printing platform are controlled so that the center distance of the ink droplets can be accurately controlled, thereby realizing the fusion of two adjacent ink droplets to form continuous lines. For example, if a 6-picoliter nozzle is used, the control spraying frequency is 28KHz, the nozzle printing direction resolution is 1440DPI, and the relative movement speed between the nozzle and the print nozzle is about 490mm / s, then it can be calculated that the center distance of the jet landing point is 18 microns, and the ink dots are theoretically hemispherical when sprayed onto the printing surface. Considering the diffusion of the ink dots, the diameter of the ink dots is generally 25-30 microns. Under this condition, the ink dots merge with each other to form continuous lines, and the lines are distributed according to the contour of the graphic to form a smooth surface.

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

[0135] S100, obtaining a pre-printed 3D model.

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

[0137] That is, when printing a 3D model, the 3D model can be layered to obtain multiple expected printing images, and then each expected printing image can be printed after image recognition, contour segment interception, classification, target printing path planning, and target nozzle determination in steps S110-S140, thereby obtaining a target image after 3D printing corresponding to each expected printing image after layering. After that, the multiple target images can be 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 a plurality of nozzles, and the plurality of nozzles correspond to a plurality of spraying areas one by one. 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 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.

[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 nozzle associated with the specified edge contour segment and the corresponding area inside the sub-image, so that the target nozzle takes the specified edge contour segment as the starting point and sprays 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 the 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, the 3D printer is connected to the control unit, and a plurality of nozzles are arranged on the piezoelectric inkjet print head of the 3D printer; ink is sprayed through the nozzles, and the diameter of the ink is larger 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, an embodiment of 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] Furthermore, 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 realized 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, etc. 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 only one type of bus.

[0149] The processor 130 may be an integrated circuit chip with signal processing capabilities. In the implementation process, each step of the above method can be completed by the hardware integrated logic circuit or software instructions in the processor 130. The above processor 130 can be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it can 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 gates or transistor logic devices, discrete hardware components. The methods, steps and logic block diagrams disclosed in the embodiments of the present invention can be implemented or executed. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor, etc. The steps of the method disclosed in the embodiment of the present invention can be directly embodied as a hardware decoding processor for execution, or a combination of hardware and software modules in the decoding processor for execution. The software module may be located in a storage medium mature in the art, such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory, or an electrically erasable programmable memory, a register, etc. The storage medium is located in the memory 131, and the processor 130 reads the information in the memory 131 and completes the steps of the method of the above embodiment in combination with its hardware.

[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 method is executed.

[0151] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the system and device described above can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here.

[0152] In addition, in the description of the embodiments of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal communication of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to 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, including several instructions for a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the methods of each embodiment 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, etc. Various media that can store program codes.

[0154] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0155] Finally, it should be noted that the above embodiments are only specific implementations of the present invention, which are used to illustrate the technical solutions of the present invention, rather than to limit them. The protection scope of the present invention is not limited thereto. Although the present invention is described in detail with reference to the above embodiments, those skilled in the art should understand that any person skilled in the art can still modify the technical solutions recorded in the above embodiments within the technical scope disclosed by the present invention, or can easily think of changes, or make equivalent replacements for some of the technical features therein; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope 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, and the 3D printer is connected to the control unit; a plurality of nozzles are arranged on a piezoelectric inkjet print head of the 3D printer; 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 line segment, and opening a target nozzle associated with the designated edge contour line segment, so that the target nozzle takes one end point of the designated edge contour line segment as a starting point and the other end point of the designated edge contour line segment as an end point, and ejects ink along the designated edge contour line segment to obtain the designated edge contour line segment; and filling the sub-graphic internally by the piezoelectric inkjet print head; All the sub-graphics are combined to obtain a target printed 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 line segment is determined to be the designated edge contour line 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 comprises: 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, characterized in that For each of the sub-images, 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: 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; Determine the printing priority by combining the line segment type, the number of line segments and the line segment length of the edge contour line segments in the plurality of edge contour line segment collections; Based on the printing priority, a plurality of the 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 type of the edge contour line segments to obtain a plurality of edge contour line segment collections comprises: If the line segment type is unique and the line segment type is a straight line segment, dividing the plurality of edge contour line segments 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-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 a plurality of sub-collections of curved contour line segments.

6. The method according to claim 5, characterized in that The line segment type is unique; and the step of determining the printing priority in combination with the line segment type, the number of line segments and the length of the line segments comprises: Determine 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 in combination with the line segment type, the number of line segments and the length of the line segments comprises: Determine a first collection of straight contour line segments including a target straight contour line segment greater than a preset length threshold as a first printing priority; Determining a second straight line contour segment collection that does not include the target straight line contour segment as a second priority; Determine the first curve contour line segment collection including the 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 contours 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 a piezoelectric inkjet print head of the 3D printer is provided with a plurality of 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, used for cutting the edge contour of each sub-image to obtain a plurality of edge contour line segments; An extraction module, used for 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 which 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 line segment, and to open a target nozzle associated with the designated edge contour line segment and a corresponding area inside the sub-image, so that the target nozzle takes the designated edge contour line segment as a starting point and sprays ink to the area inside the sub-image 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. A plurality of nozzles are arranged on the piezoelectric inkjet print head of the 3D printer. The 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 described in any one of claims 1 to 8.

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