Stereolithography three-dimensional printing method and device

Abstract

The present invention provides a light-curing three-dimensional printing method, comprising: obtaining a three-dimensional data model of a printing object; dividing the three-dimensional data model into a plurality of printing layers, each printing layer corresponding to an original exposure image; dividing each original exposure image into a plurality of sub-images of equal size, each sub-image corresponding to an imaging unit in an imaging system; dividing each sub-image into N*N sub-regions of equal size, where N is an integer greater than or equal to 2; and using the imaging system to perform layer-by-layer exposure curing on a photosensitive material according to each original exposure image. During the exposure curing process of each printing layer, the imaging system is moved so that each imaging unit sequentially aligns with each sub-region in the sub-image according to a preset path, and the preset path includes at least one X-shaped route. Wherein, during the movement of the imaging system, the position of the sub-region aligned by each imaging unit in the sub-image is the same.

Description

Technical Field

[0001] The present invention mainly relates to the technical field of three-dimensional printing, and particularly relates to a method and device for stereolithography three-dimensional printing. Background Art

[0002] Three-dimensional (3D) printing technology uses a computer three-dimensional design model as a blueprint. Through software layer-by-layer discretization and a numerical control forming system, special materials such as metal powder, ceramic powder, plastic, and cell tissue are stacked and bonded layer by layer using a laser beam, hot melt nozzle, etc., and finally stacked into a shape to manufacture a physical product. Different from traditional manufacturing industries that shape and cut raw materials through mechanical processing methods such as molds, turning, and milling to finally produce finished products, 3D printing transforms a three-dimensional entity into several two-dimensional planes and produces by processing materials and stacking them layer by layer, greatly reducing the complexity of manufacturing. This digital manufacturing mode does not require complex processes, large machine tools, or a large number of human resources, and can directly generate parts of any shape from computer graphic data, extending production and manufacturing to a wider range of production populations.

[0003] Currently, the forming methods of 3D printing technology are still evolving, and the materials used are also diverse. Among various forming methods, the stereolithography method is a relatively mature method. The stereolithography method uses the principle that a photosensitive resin cures after being irradiated by an ultraviolet laser to perform material accumulation forming, and has the characteristics of high forming accuracy, good surface finish, and high material utilization rate.

[0004] Figure 1 is a schematic structural diagram of the basic structure of a stereolithography 3D printing device. Refer to Figure 1 As shown, the 3D printing device 100 includes a material tank 110 for containing a photosensitive resin, an imaging system 120 for curing the photosensitive resin, and a lifting table 130 for connecting the formed workpiece. The imaging system 120 is located above the material tank 110 and can irradiate a beam image to cure a layer of the photosensitive resin on the liquid surface of the material tank 110. Each time the imaging system 120 irradiates a beam image to cause a layer of the photosensitive resin to cure, the lifting table 130 will drive the formed layer of the photosensitive resin to slightly descend, and a squeegee 131 is used to evenly spread the photosensitive resin on the top surface of the cured workpiece and wait for the next irradiation. By repeating this cycle, a three-dimensional workpiece formed by layer-by-layer accumulation will be obtained.

[0005] The surface quality of the formed workpiece depends to a great extent on the resolution of the image during the curing of each layer. The imaging system 120 in the stereolithography 3D printing device usually adopts technologies such as Liquid Crystal Display (LCD), Liquid Crystal on Silicon (LCOS), and Digital Light Procession (DLP). However, due to limitations such as manufacturing processes and manufacturing costs, high-resolution imaging components cannot be widely applied. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a stereolithography three-dimensional printing method and device with low cost and high resolution.

[0007] To solve the above technical problem, the present invention provides a stereolithography three-dimensional printing method, which is characterized by including: obtaining a three-dimensional data model of a printing object; dividing the three-dimensional data model into multiple printing layers, each printing layer corresponding to an original exposure image; dividing each original exposure image into multiple sub-images of equal size, each sub-image corresponding to an imaging unit in the imaging system; dividing each sub-image into N*N sub-regions of equal size, where N is an integer greater than or equal to 2; and using the imaging system to perform layer-by-layer exposure curing on the photosensitive material according to each original exposure image. During the exposure curing process of each printing layer, the imaging system is moved so that each imaging unit sequentially aligns with each sub-region in the sub-image according to a preset path, and the preset path includes at least one X-shaped route. Among them, during the movement of the imaging system, the position of the sub-region aligned by each imaging unit in the sub-image is the same.

[0008] In an embodiment of the present invention, the step of dividing each sub-image into N*N sub-regions of equal size includes: dividing each sub-image into N rows by N columns of sub-regions of equal size according to rows and columns, and the preset path further includes a straight-line route along one of the rows or columns.

[0009] In an embodiment of the present invention, the step of curing the photosensitive material layer by layer according to each of the original exposure images using the imaging system includes: sequentially assigning a serial number i to each sub-region in each sub-image according to the preset path, where the serial numbers of the sub-regions at the same position in each sub-image are the same, and i is a positive integer less than or equal to N*N; sequentially extracting the i-th sub-region image in each sub-region from each sub-image according to the order of the serial numbers and combining them to generate the i-th combined exposure image; moving the imaging system to a preset position in the preset path according to the preset path; loading the combined exposure image corresponding to the preset position; and turning on the exposure light source in the imaging system and irradiating the photosensitive material according to the combined exposure image.

[0010] In an embodiment of the present invention, the imaging unit determines whether to irradiate the photosensitive material corresponding to the sub-region according to the combined exposure image.

[0011] In an embodiment of the present invention, it further includes: after irradiating a combined exposure image, turning off the exposure light source and moving the imaging system to the next preset position.

[0012] In an embodiment of the present invention, N is an even number greater than or equal to 4.

[0013] In an embodiment of the present invention, the N rows by N columns of the multiple sub-regions form a matrix, and the starting point of the preset path is the sub-region located at the lower left corner of the matrix.

[0014] The present invention also provides a photo-curing three-dimensional printing device to solve the above technical problems, which is characterized in that it includes: a model acquisition module for obtaining a three-dimensional data model of a printing object; a layering module for dividing the three-dimensional data model into multiple printing layers, each printing layer corresponding to an original exposure image; an image processing module for dividing each of the original exposure images into multiple sub-images of equal size, each sub-image corresponding to an imaging unit in the imaging system, and dividing each sub-image into N*N sub-regions of equal size, where N is an integer greater than or equal to 2; an imaging system including multiple imaging units for curing the photosensitive material layer by layer according to each of the original exposure images; and a controller for moving the imaging system during the exposure curing process of each printing layer, so that each imaging unit sequentially aligns with each sub-region in the sub-image according to a preset path, and the preset path includes at least one X-shaped route, wherein during the movement of the imaging system, the position of the sub-region aligned by each imaging unit in the sub-image is the same.

[0015] In an embodiment of the present invention, the image processing module is further configured to divide each sub-image into N rows by N columns of sub-regions with equal sizes according to rows and columns, and the preset path further includes a straight-line path along one of the rows or columns.

[0016] In an embodiment of the present invention, the imaging system includes an exposure light source, and the controller is further configured to control the turning on and off of the exposure light source.

[0017] In an embodiment of the present invention, the image processing module is further configured to generate N*N combined exposure images according to the original exposure image, including: sequentially assigning a serial number i to each sub-region in each sub-image according to the preset path, where the serial numbers of the sub-regions at the same position in each sub-image are the same, and i is a positive integer less than or equal to N*N; and sequentially extracting the i-th sub-region image in each sub-region from each sub-image according to the order of the serial numbers and combining them to generate the i-th combined exposure image.

[0018] In an embodiment of the present invention, the controller is further configured to move the imaging system to a preset position in the preset path according to the preset path, load the combined exposure image corresponding to the preset position, and turn on the exposure light source in the imaging system to irradiate the photosensitive material according to the combined exposure image.

[0019] In an embodiment of the present invention, the imaging unit determines whether to irradiate the photosensitive material corresponding to the sub-region according to the combined exposure image.

[0020] In an embodiment of the present invention, after the irradiation of a combined exposure image is completed, the controller is further configured to turn off the exposure light source and move the imaging system to the next preset position.

[0021] The three-dimensional printing method and device of the present invention expose and cure multiple sub-regions by using a preset path including an X-shaped path, so that the exposure degrees experienced by each sub-region are relatively average, thereby uniform voxels can be obtained. While improving the resolution and accuracy of the printed product, the printed product has a smooth surface, improving the surface quality, and reducing the risk of deformation caused by stress. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings are provided to provide a further understanding of the present application, and they are incorporated into and constitute a part of the present application. The accompanying drawings illustrate embodiments of the present application and, together with this specification, serve to explain the principles of the present invention. In the accompanying drawings:

[0023] Figure 1 is a schematic diagram of the basic structure of a light-curing 3D printing device;

[0024] Figure 2A It is a schematic diagram of the displacement of a single pixel point in the pixel multiplexing technology;

[0025] Figure 2B It is adopted Figure 2A A schematic diagram of the formed surface formed by the pixel multiplexing technology shown;

[0026] Figure 3 It is an exemplary flowchart of the photocuring three-dimensional printing method according to an embodiment of the present invention;

[0027] Figure 4 It is a schematic diagram of the contour of a partial area of a printing layer and the sequence of sub-areas for exposure curing in the photocuring three-dimensional printing method according to an embodiment of the present invention;

[0028] Figure 5 It is from Figure 4 A schematic diagram of 16 combined exposure images extracted from the original exposure image shown;

[0029] Figure 6 It is a schematic diagram of the printing effect of the three-dimensional printing method according to an embodiment of the present invention;

[0030] Figure 7 It is a system block diagram of the photocuring three-dimensional printing device according to an embodiment of the present invention. Detailed implementation manners

[0031] To more clearly illustrate the technical solutions of the embodiments of the present application, the accompanying drawings required for the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some examples or embodiments of the present application. For those of ordinary skill in the art, without creative efforts, the present application can also be applied to other similar scenarios based on these drawings. Unless obvious from the language context or otherwise stated, the same reference numerals in the drawings represent the same structure or operation.

[0032] As shown in the present application and the claims, unless the context clearly indicates an exceptional situation, words such as "a", "an", "one" and / or "the" are not specifically singular and may also include plural. Generally speaking, the terms "include" and "comprise" only indicate the inclusion of the clearly identified steps and elements, and these steps and elements do not constitute an exclusive list. The method or device may also include other steps or elements.

[0033] Unless otherwise specifically stated, the relative arrangements of components and steps, numerical expressions, and numerical values set forth in these embodiments do not limit the scope of this application. At the same time, it should be understood that, for the sake of convenience in description, the dimensions of the various parts shown in the drawings are not drawn in actual proportional relationship. Technologies, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, such technologies, methods, and devices should be regarded as part of the authorization specification. In all the examples shown and discussed here, any specific value should be construed as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that like reference numerals and letters denote like items in the following drawings, and thus, once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0034] In the description of this application, it should be understood that the orientation or positional relationships indicated by orientation terms such as "front, rear, upper, lower, left, right", "lateral, vertical, perpendicular, horizontal", and "top, bottom", etc., are generally based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing this application and simplifying the description. Without contrary description, these orientation terms do not indicate and imply that the devices or elements referred to must have a specific orientation or be constructed and operated in a specific orientation, and thus cannot be construed as limiting the protection scope of this application; the orientation terms "inside, outside" refer to the inside and outside relative to the contour of each component itself.

[0035] For the convenience of description, spatial relative terms such as "above...", "over...", "on the upper surface of...", "above", etc., can be used here to describe the spatial positional relationship of a device or feature shown in the drawings with other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation in addition to the orientation depicted in the drawings. For example, if the device in the drawing is inverted, the device described as "above other devices or structures" or "over other devices or structures" will then be positioned "below other devices or structures" or "under other devices or structures". Thus, the exemplary term "above..." can include both the orientations of "above..." and "below...". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and corresponding interpretations should be made for the spatial relative descriptions used here.

[0036] In addition, it should be noted that the use of words such as "first" and "second" to define components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above words have no special meaning and cannot be understood as limiting the scope of protection of this application. In addition, although the terms used in this application are selected from well-known and commonly used terms, some terms mentioned in the specification of this application may be selected by the applicant at his or her discretion, and their detailed meanings are explained in the relevant parts of the description of this article. In addition, it is required to understand this application not only by the actual terms used, but also by the meaning implied by each term.

[0037] Flowcharts are used in the present application to illustrate the operations performed by the system according to the embodiments of the present application. It should be understood that the preceding or following operations are not necessarily performed accurately in order. On the contrary, various steps may be processed in reverse order or simultaneously. At the same time, other operations may be added to these processes, or one or more operations may be removed from these processes.

[0038] In order to overcome the problem of low resolution in current photo-curing 3D printing, pixel multiplexing technology can be used to achieve high-resolution printing effects at a lower cost, but there are still certain problems in its application.

[0039] Pixel multiplexing technology refers to making any single exposure element perform multiple effective and short exposures at different positions in the exposure area that the exposure element is responsible for by means of physical displacement or optical deflection, etc., and achieving smaller molding voxels by controlling the exposure amount, which is approximately equivalent to using a higher-resolution exposure element for photocuring. The exposure element here can be an imaging element corresponding to one pixel. Figure 2A This is a schematic diagram of the displacement of a single exposure element in pixel multiplexing technology. Figure 2A As shown, the exposure area that a single exposure element is responsible for is divided into a 4*4 matrix, wherein each circle with a number in the middle represents a sub-pixel. Figure 2A In the example, a single exposure element starts from point O and follows the zigzag route indicated by the arrow to reach the positions indicated by R1, R2, ..., R7 in turn, thereby realizing the exposure of all 16 sub-pixels, forming a solidified sub-voxel at the position of each sub-pixel, and the 16 sub-voxels form the voxel corresponding to the exposure element. However, according to this row-by-row exposure method, the current exposure will produce solidification and reinforcement on one or more sub-voxels solidified by the previous exposure, and the solidified voxels will consume the unsolidified resin in other sub-areas, so that the area to be exposed later cannot form solidified resin according to the predetermined shape.

[0040] Figure 2B Is adopted Figure 2A Schematic diagram of the shaped surface formed by the pixel multiplexing technology shown.Figure 2B as shown, where the exposure area 210 is Figure 2A the exposure area responsible for by a single exposure element shown in Figure 2B A total of 4 adjacent exposure areas are shown, which are respectively responsible for by 4 single exposure elements in the imaging system. Taking the exposure area 210 as an example, after scanning line by line in a zigzag route, due to several subsequent curing and strengthening processes, the area of the 1st sub-voxel at the starting point is the largest, and the areas of the 2nd, 3rd, and 4th sub-voxels decrease in turn. A volume feature that is first large and then small in the row direction is formed on the surface of the actually formed molded workpiece, and the larger sub-voxels usually significantly exceed their due volume sizes and even engulf adjacent sub-voxels. On the other hand, such line-by-line printing will accumulate stress during the exposure process, which is not conducive to the later maintenance of the cured model and even large deformations occur during the printing process. According to Figure 2A and 2B the pixel multiplexing technology shown will reduce the actual resolution and accuracy of the printed product, and also reduce the smoothness of the upper surface of the printed product.

[0041] Figure 3 is an exemplary flowchart of a light-curing three-dimensional printing method according to an embodiment of the present invention. Referring to Figure 3 as shown, the printing method of this embodiment includes the following steps:

[0042] Step S310: Obtain a three-dimensional data model of the printing object;

[0043] Step S320: Divide the three-dimensional data model into multiple printing layers, and each printing layer corresponds to an original exposure image;

[0044] Step S330: Divide each original exposure image into multiple sub-images of equal size, and each sub-image corresponds to an imaging unit in the imaging system;

[0045] Step S340: Divide each sub-image into N*N sub-regions of equal size, where N is an integer greater than or equal to 2; and

[0046] Step S350: Use the imaging system to expose and cure the photosensitive material layer by layer according to each original exposure image. During the exposure and curing process of each printing layer, move the imaging system so that each imaging unit sequentially aligns with each sub-region in the sub-image according to a preset path. The preset path includes at least one X-shaped route, where, during the movement of the imaging system, the position of the sub-region aligned by each imaging unit in the sub-image is the same.

[0047] The present invention does not limit the specific implementation methods of steps S310 and S320, and the three-dimensional printing methods in the art can be used to execute them. Steps S330 - S350 are the printing steps to be executed for each printing layer, and steps S330 - S350 can be cyclically executed until the exposure curing of each printing layer of the entire three-dimensional data model is completed, thereby obtaining the final formed workpiece.

[0048] The following Figures 4 - 6 is used to illustrate the above steps S330 - S350.

[0049] Figure 4 is a schematic diagram of the contour of a partial area of a printing layer and the sequence of sub-areas for exposure curing in the light-curing three-dimensional printing method according to an embodiment of the present invention. Referring to Figure 4 and Figure 2B , Figure 4 shown, the similarities with Figure 2B shown are that Figure 4 also shows 4 adjacent exposure areas, which are respectively responsible for by 4 single imaging units in the imaging system.

[0050] Figure 4 shown is only for illustration and does not limit the size, arrangement method, quantity, etc. of the exposure area.

[0051] The present invention does not limit the size and pattern of the original exposure image. Figure 4 shown gives an example. In this example, the original exposure image is divided into two areas along the diagonal. Among them, most of the area in the upper right is filled with white, indicating that exposure is required, and most of the area in the lower left is filled with slashes, indicating that exposure is not required. The original exposure image can be formed by requiring exposure and not requiring exposure.

[0052] In step S330, the original exposure image is divided into multiple sub-images of equal size. Referring to Figure 4 shown, the original exposure image is divided into 4 sub-images C1, C2, C3, and C4 of equal size. Among them, each sub-image is square and adjacent to each other. The present invention does not limit the shape, size, quantity, and arrangement method of the sub-images. For example, the sub-images can be staggered instead of aligned in rows and columns as Figure 4 shown.

[0053] In step S330, each sub-image corresponds to an imaging unit in the imaging system. The imaging system provides a light source during the three-dimensional printing process and irradiates the liquid photosensitive material corresponding to each printing layer according to the original exposure image corresponding to each printing layer. An imaging system may include multiple imaging units, and the number of imaging units is related to the resolution of the three-dimensional model to be printed. For example, if an LCD imaging device with a resolution of 1920*1080 is used, the number of imaging units included is 1920*1080. Correspondingly, each sub-image also corresponds to an image of one pixel. The size of the sub-image is equivalent to the size of one pixel.

[0054] In step S340, each sub-image is divided into N*N sub-regions of equal size, where N is an integer greater than or equal to 2. In Figure 4 the illustrated embodiment, N = 4. Each sub-image is divided into 4*4 sub-regions of equal size, and the individual sub-regions are labeled with numbers 1-16 in Figure 4 . In Figure 4 , each sub-region is square. The present invention places no restrictions on the shape, size, quantity, and arrangement of the sub-regions. For example, the sub-regions can be rectangles, triangles, etc. of equal size, and their distribution can be staggered, rather than aligned in rows and columns as shown in Figure 4 .

[0055] In some embodiments, N is an even number greater than or equal to 4. For example, N = 4, 6, 8, 10, etc.

[0056] In step S350, the three-dimensional printing device includes an imaging system. When exposing and curing each printing layer, the imaging system irradiates the photosensitive material according to the original exposure image corresponding to the printing layer and performs exposure in the sub-regions that need to be exposed. The imaging system includes multiple imaging units, and each imaging unit corresponds to a sub-image, that is, it is responsible for the exposure of one sub-image. As shown in Figure 4 , assume that imaging unit G1 is responsible for sub-image C1, imaging unit G2 is responsible for sub-image C2, and so on. Then, in the imaging system, the positional relationship of imaging units G1-G4 is similar to the positional relationship of sub-images C1-C4.

[0057] Assume that at the start, an imaging unit aligns with a sub-region in the sub-image, for example, sub-region 1. Then each imaging unit aligns with sub-region 1 in the sub-image it corresponds to. When moving the imaging system, multiple imaging units are moved simultaneously, and the movement path of each imaging unit is a preset path.

[0058] Figure 4The preset paths are marked in ascending order of numbers, that is to say, the preset paths are in the order from 1 to 16. Obviously, such preset paths include at least one X-shaped route. For example, in Figure 4 the illustrated embodiment, there are 4 X-shaped routes, namely 1-2-3-4, 5-6-7-8, 9-10-11-12, and 13-14-15-16. The preset paths of the present invention are non-line-by-line scanning routes. For embodiments where N is greater than or equal to 2, compared with the conventional line-by-line scanning, two adjacent position points in the preset paths of the present invention are not in the same row. For some adjacent position points, they are neither in the same row nor in the same column.

[0059] The present invention does not limit whether the preset path is a straight line or a curve. That is to say, from sub-region 1 to sub-region 2, it can move in a straight line or in a curve. In short, the preset path includes at least one X-shaped route with intersection points. For a matrix larger than 3*3 in size, on the two diagonal lines forming the X-shaped route of the preset path, it is preferable that there is at least one sub-region interval between the two end points of the diagonal line. For example, Figure 4 there is one sub-region 5 interval between sub-region 1 and sub-region 2, and there is also one sub-region 5 interval between sub-region 3 and sub-region 4, thus forming the X-shaped route 1-2-3-4. Since the X-shaped route 1-2-3-4 has been formed, there is no sub-region interval between sub-region 4 and sub-region 5. Instead, in order to move the imaging system to sub-region 5, another X-shaped route 5-6-7-8 starts to be formed.

[0060] In some embodiments, the step of dividing each sub-image into N*N sub-regions of equal size in step S340 includes: dividing each sub-image into N rows by N columns of sub-regions of equal size according to rows and columns. The preset path also includes a straight-line route along one of the rows or columns. These embodiments define that the arrangement manner of the sub-regions is in a matrix manner of N rows by N columns, as Figure 4 shown, that is to say, the sub-regions are aligned according to rows and columns. According to these embodiments, in order to improve the printing speed, following the principle of the shortest path, the preset path for the imaging system to move is in a straight line. The X-shaped route therein includes two intersecting straight lines. For example, the diagonal line from sub-region 1 to sub-region 2 and the diagonal line from sub-region 3 to sub-region 4, and the moving route is the connection line of two sub-regions; from sub-region 2 to sub-region 3, the moving route is a straight line along the column direction. In Figure 4 it, the column is in the vertical direction and the row is in the horizontal direction. It can be understood that if the preset path is continuous, then in order to form an X-shaped route, a straight-line route along the row or column is also necessarily required.

[0061] In Figure 4In the illustrated embodiment, the preset path only includes an X-shaped route and a straight-line route along the column direction, and does not include a straight-line route along the row direction. In other embodiments, the preset path may only include an X-shaped route and a straight-line route along the row direction, and does not include a straight-line route along the column direction.

[0062] In an embodiment of the present invention, during the movement of the imaging system along the preset path, some position points are only passed through once, and some position points are passed through multiple times. Regardless of the number of times passed through, the imaging system is only exposed once at each position point.

[0063] In some embodiments, the step of using the imaging system to perform layer-by-layer exposure and curing of the photosensitive material in step S350 includes:

[0064] Step S351: Sequentially assign a serial number i to each sub-region in each sub-image according to the preset path. The serial numbers of the sub-regions at the same position in each sub-image are the same, and i is a positive integer less than or equal to N*N.

[0065] Reference Figure 4 As shown, the number marked in each sub-region is the serial number of that sub-region. In the Figure 4 illustrated embodiment, N = 4, then the positive integers from 1 to 16. As Figure 4 shown, in each sub-image C1 - C4, the serial numbers of the sub-regions at the same position are the same.

[0066] Step S352: Sequentially extract the i-th sub-region image from each sub-region in each sub-image according to the order of the serial numbers and combine them to generate the i-th combined exposure image.

[0067] Figure 5 is from Figure 4 a schematic diagram of 16 combined exposure images extracted from the original exposure images shown. Taking the first combined exposure image D1 as an example, this combined exposure image includes 4 sub-region images extracted from 4 sub-images C1 - C4, and the serial numbers are all 1. Therefore, in the figure, it is shown as four squares numbered 1 combined together to form the combined exposure image D1. Combining Figure 4 shown, in sub-images C1 - C3, the images in sub-region 1 are filled with diagonal lines, indicating that no exposure is required. In sub-image C4, the image in sub-region 1 is filled with white, indicating that exposure is required. Then when the four imaging units G1 - G4 in the imaging system are respectively aligned with the four sub-regions 1, the imaging units G1 - G3 do not need to provide light, and the imaging unit G4 needs to provide light. And so on, 16 combined exposure images as shown in Figure 5 are generated in sequence from 1 to 16, and each combined exposure image is composed of four sub-region images.

[0068] Step S353: Move the imaging system to a preset position in the preset path according to the preset path.

[0069] Before starting the entire exposure curing process, the imaging unit may not be aligned with any sub-region. Then, after starting the exposure curing process, it is necessary to first move the imaging system to the first position in the preset path according to the preset path, that is, the position of the sub-region numbered 1. This preset position corresponds to the position of each sub-region.

[0070] As Figure 4 shown, in some embodiments, a plurality of N-row by N-column sub-regions form a matrix, and the starting point of the preset path is the sub-region located at the lower left corner of the matrix. In other embodiments, there is no restriction on the starting point position of the preset path, and the position of any sub-region can be used as the starting point of the preset path.

[0071] Step S354: Load the combined exposure image corresponding to the preset position.

[0072] For the imaging system, in this step, it is necessary to load the combined exposure image to be currently used into the corresponding components of the imaging system. As Figure 5 shown, the sub-region numbers at different preset positions are different, and the corresponding combined exposure images are also different. Therefore, it is necessary to load the correct combined exposure image.

[0073] Step S355: Turn on the exposure light source in the imaging system and irradiate the photosensitive material according to the combined exposure image.

[0074] As Figure 5 shown, according to the previous steps S351 - S354, each imaging unit has been aligned with the corresponding sub-region according to the number, and the imaging system has loaded the combined exposure image corresponding to this number. Then, in this step, turn on the exposure light source to start exposure imaging.

[0075] In some embodiments, the imaging unit determines whether to irradiate the photosensitive material corresponding to the sub-region according to the combined exposure image. It can be understood that the photosensitive material here is a liquid photosensitive material, such as liquid photosensitive resin, and can also be other mixed materials containing liquid photosensitive resin, such as slurries mixed with ceramic powder or metal powder.

[0076] For the imaging unit in the imaging system, the need for exposure also indicates that the state of the imaging unit is on, so that the light emitted by the light source passes through the imaging unit and irradiates the corresponding area on the photosensitive material; the need for no exposure also indicates that the state of the imaging unit is off, then the light emitted by the light source will not pass through the imaging unit and irradiate the corresponding area on the photosensitive material. In this step, according to the combined exposure image, some imaging units are in the on state and some imaging units are in the off state. As Figure 5Among them, taking the 16th combined exposure image D16 as an example, this combined exposure image includes 4 sub-region images extracted from 4 sub-images C1 - C4, and the serial numbers are all 16. Among them, in sub-images C1 - C2, the images in sub-region 16 are filled with diagonal lines, indicating that imaging units G1 and G2 are in the off state at step S355; in sub-images C3 - C4, the images in sub-region 16 are filled with white, indicating that imaging units G3 and G4 are in the on state at step S355.

[0077] When printing a printing layer, by traversing the positions where each sub-region is located according to a preset path, the printing of the original exposure image corresponding to a printing layer can be completed.

[0078] In some embodiments, after irradiating a combined exposure image, the exposure light source is turned off, and the imaging system is moved to the next preset position. According to these embodiments, during the printing process of a printing layer, the exposure light source needs to be turned on and off multiple times, and the number of times is related to the number of sub-regions. In Figure 5 the illustrated embodiment, the exposure light source needs to be turned on and off 16 times respectively.

[0079] In some embodiments, in step S355, the time length for which the exposure light source is turned on to irradiate the sub-region is a preset length. Assuming that in a normal three-dimensional printing process, the time length for a single imaging unit to irradiate a sub-image is T, then the preset length for this imaging unit to irradiate the sub-region is T / (N * N). In Figure 4 the illustrated embodiment, assuming T = 1 second, then the preset length is 1 / 16 second. According to this embodiment, for a sub-image, its total exposure time is constant.

[0080] In some embodiments, the size of a sub-image is equal to 1 pixel, then the size of each sub-region is equal to 1 / (N * N) pixels. In some embodiments, one imaging unit corresponds to 1 pixel in the original exposure image. According to these embodiments, using one imaging unit to perform N * N exposures in a sub-image is equivalent to increasing the resolution of the formed image by at least N * N times.

[0081] Figure 6 It is a schematic diagram of the printing effect of a three-dimensional printing method according to an embodiment of the present invention. Figure 6 The illustrated sub-images and sub-regions correspond to Figure 4 the illustrated sub-images and sub-regions. Referring to Figure 6 as shown, taking sub-image C1 as an example, due to the preset path including an X-shaped route adopted in the present invention, the size of sub-region 1, which was enlarged and strengthened in the original line-by-line scanning, is significantly reduced, and the area sizes of each sub-region are relatively average. As Figure 6In this case, the voxel areas formed at sub-regions 1-4 are substantially equal. Moreover, after sub-regions 1-4 are cured, sub-region 5 is in a basin, and it is difficult for the external liquid photosensitive material to enter sub-region 5, thereby also restricting the further enlargement of sub-region 5.

[0082] According to the three-dimensional printing method of the present invention, a plurality of sub-regions are exposed and cured by using a preset path including an X-shaped route, so that the exposure degrees experienced by the respective sub-regions are relatively average, thereby uniform voxels can be obtained. While improving the resolution and accuracy of the printed product, the printed product has a smooth surface, improving the surface quality, and reducing the risk of deformation caused by stress.

[0083] Figure 7 It is a system block diagram of a light-curing type three-dimensional printing device according to an embodiment of the present invention. The light-curing type three-dimensional printing method described above in the present invention can be specifically implemented by the light-curing type three-dimensional printing device 700. Therefore, the foregoing content can all be used to illustrate the light-curing type three-dimensional printing device 700 of the present invention, and the same content will not be repeated.

[0084] Reference Figure 7 As shown, the light-curing type three-dimensional printing device 700 of this embodiment includes a model acquisition module 710, a layering module 720, an image processing module 730, an imaging system 740, and a controller 750. Among them, the model acquisition module 710 is used to obtain a three-dimensional data model of a printing object; the layering module 720 is used to divide the three-dimensional data model into a plurality of printing layers, and each printing layer corresponds to an original exposure image; the image processing module 730 is used to divide each original exposure image into a plurality of sub-images of equal size, and each sub-image corresponds to an imaging unit in the imaging system 740, and divide each sub-image into N*N sub-regions of equal size, where N is an integer greater than or equal to 2; the imaging system 740 includes a plurality of imaging units, which are used to perform layer-by-layer exposure and curing on the photosensitive material according to each original exposure image; the controller 750 is used to move the imaging system 740 during the exposure and curing process of each printing layer, so that each imaging unit sequentially aligns with each sub-region in the sub-image according to a preset path. The preset path includes at least one X-shaped route. Among them, during the movement of the imaging system 740, the position of the sub-region aligned by each imaging unit in the sub-image is the same.

[0085] In some embodiments, the image processing module 730 is further used to divide each sub-image into N rows by N columns of sub-regions of equal size according to rows and columns, and the preset path further includes a straight-line route along one of the rows or columns.

[0086] In some embodiments, the imaging system 740 includes an exposure light source, and the controller 750 is further used to control the turning on and off of the exposure light source.

[0087] In some embodiments, the image processing module 730 is further configured to generate N*N combined exposure images based on the original exposure image, including: sequentially assigning a serial number i to each sub-region in each sub-image according to a preset path, where the serial numbers of the sub-regions at the same position in each sub-image are the same, and i is a positive integer less than or equal to N*N; and sequentially extracting the i-th sub-region image in each sub-region from each sub-image according to the order of the serial numbers and combining them to generate the i-th combined exposure image.

[0088] In some embodiments, the controller 750 is further configured to move the imaging system 740 to a preset position in the preset path according to the preset path, load the combined exposure image corresponding to the preset position, and turn on the exposure light source in the imaging system 740 to irradiate the photosensitive material according to the combined exposure image.

[0089] In some embodiments, the imaging unit determines whether to irradiate the photosensitive material corresponding to the sub-region according to the combined exposure image.

[0090] In some embodiments, after irradiating one combined exposure image, the controller 750 is further configured to turn off the exposure light source and move the imaging system 740 to the next preset position.

[0091] In some embodiments, the controller 750 uses a micro actuator to move the imaging system 740.

[0092] After completing the printing of one printing layer, the same method is used to print the next printing layer, and finally the printing of the entire three-dimensional data model is completed.

[0093] By using the stereolithography three-dimensional printing device of the present invention, a formed workpiece with high resolution and precision can be obtained at low cost, and the formed workpiece has the advantages of stable structure, not easy to deform, and smooth surface.

[0094] The basic concepts have been described above. Obviously, for those skilled in the art, the above invention disclosure is only an example and does not constitute a limitation to this application. Although not explicitly stated here, those skilled in the art may make various modifications, improvements, and corrections to this application. Such modifications, improvements, and corrections are proposed in this application, so such modifications, improvements, and corrections still belong to the spirit and scope of the exemplary embodiments of this application.

[0095] Meanwhile, this application uses specific terms to describe the embodiments of this application. For example, "an embodiment", "one embodiment", and / or "some embodiments" mean a certain feature, structure, or characteristic related to at least one embodiment of this application. Therefore, it should be emphasized and noted that the "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or more at different positions in this specification does not necessarily refer to the same embodiment. In addition, certain features, structures, or characteristics in one or more embodiments of this application can be appropriately combined.

[0096] Some aspects of this application can be executed entirely by hardware, entirely by software (including firmware, resident software, microcode, etc.), or by a combination of hardware and software. The above-mentioned hardware or software can all be referred to as "data blocks", "modules", "engines", "units", "components", or "systems". The processor can be one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DAPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, or a combination thereof. In addition, aspects of this application may be embodied as a computer product located in one or more computer-readable media, which includes computer-readable program code. For example, computer-readable media may include, but are not limited to, magnetic storage devices (such as hard disks, floppy disks, magnetic tapes...), optical disks (such as compact disks CD, digital versatile disks DVD...), smart cards, and flash memory devices (such as cards, sticks, key drives...).

[0097] The computer-readable medium may contain a propagated data signal containing computer program code, such as on a baseband or as part of a carrier wave. This propagated signal may have various forms of representation, including electromagnetic form, optical form, etc., or a suitable combination of forms. The computer-readable medium can be any computer-readable medium other than a computer-readable storage medium, which can be connected to an instruction execution system, apparatus, or device to implement communication, propagation, or transmission for use of the program. The program code located on the computer-readable medium can be propagated through any suitable medium, including radio, cable, fiber optic cable, radio frequency signal, or similar media, or any combination of the above media.

[0098] Similarly, it should be noted that, in order to simplify the description of this application disclosure and thus help the understanding of one or more inventive embodiments, in the previous description of the embodiments of this application, sometimes multiple features are merged into one embodiment, drawing, or description thereof. However, this disclosure method does not mean that the features required by the subject matter of this application are more than those mentioned in the claims. In fact, the features of the embodiment are fewer than all the features of the single embodiment disclosed above.

[0099] In some embodiments, numbers are used to describe components and the quantity of attributes. It should be understood that such numbers used in the description of embodiments are modified by the modifiers "about", "approximate" or "substantially" in some examples. Unless otherwise stated, "about", "approximate" or "substantially" indicate that the said numbers allow a variation of ±20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximate values, which may vary according to the characteristics required by individual embodiments. In some embodiments, the numerical parameters should consider the specified significant digits and adopt the method of retaining the general number of digits. Although the numerical ranges and parameters used in some embodiments of the present application to confirm the breadth of their scope are approximate values, in specific embodiments, such numerical settings are made as precise as possible within the feasible range.

[0100] Although the present application has been described with reference to the current specific embodiments, those of ordinary skill in the art should recognize that the above embodiments are only used to illustrate the present application, and various equivalent changes or substitutions can be made without departing from the spirit of the present application. Therefore, as long as the changes and modifications to the above embodiments are within the scope of the spirit of the present application, they will fall within the scope of the claims of the present application.

Claims

1. A light-curing three-dimensional printing method, characterized in that, it includes: obtaining a three-dimensional data model of a printing object; dividing the three-dimensional data model into multiple printing layers, each printing layer corresponding to an original exposure image; dividing each of the original exposure images into multiple sub-images of equal size, each sub-image corresponding to an imaging unit in an imaging system; dividing each of the sub-images into N*N sub-regions of equal size, where N is an integer greater than or equal to 2; and using the imaging system to perform layer-by-layer exposure curing on a photosensitive material according to each of the original exposure images. During the exposure curing process of each printing layer, move the imaging system so that each imaging unit sequentially aligns with each sub-region in the sub-image according to a preset path, and the preset path includes at least one X-shaped route. Wherein, during the movement of the imaging system, the position of the sub-region aligned by each imaging unit in the sub-image is the same.

2. The light-curing three-dimensional printing method according to claim 1, characterized in that, the step of dividing each sub-image into N*N sub-regions of equal size includes: dividing each sub-image into N rows by N columns of sub-regions of equal size according to rows and columns, and the preset path further includes a straight-line route along one of the rows or columns.

3. The light-curing three-dimensional printing method according to claim 1, characterized in that, the step of using the imaging system to perform layer-by-layer exposure curing on a photosensitive material according to each of the original exposure images includes: sequentially assigning a serial number i to each sub-region in each sub-image according to the preset path, and the serial numbers of the sub-regions located at the same position in each sub-image are the same, and i is a positive integer less than or equal to N*N; sequentially extracting the i-th sub-region image in each sub-region from each sub-image according to the order of the serial numbers and combining them to generate the i-th combined exposure image; moving the imaging system to a preset position in the preset path according to the preset path; loading the combined exposure image corresponding to the preset position; and turning on the exposure light source in the imaging system and irradiating the photosensitive material according to the combined exposure image.

4. The light-curing three-dimensional printing method according to claim 3, characterized in that, the imaging unit determines whether to irradiate the photosensitive material corresponding to the sub-region according to the combined exposure image.

5. The light-curing three-dimensional printing method according to claim 3, characterized in that, it further includes: after completing the irradiation of one combined exposure image, turning off the exposure light source and moving the imaging system to the next preset position.

6. The light-curing three-dimensional printing method according to claim 1, characterized in that, N is an even number greater than or equal to 4.

7. The light-curing three-dimensional printing method according to claim 1, characterized in that, the N rows by N columns of the multiple sub-regions form a matrix, and the starting point of the preset path is the sub-region located at the lower left corner of the matrix.

8. A light-curing three-dimensional printing device, characterized in that, it includes: a model acquisition module for obtaining a three-dimensional data model of a printing object; A layering module for dividing the three-dimensional data model into multiple printing layers, each printing layer corresponding to an original exposure image; An image processing module for dividing each of the original exposure images into multiple sub-images of equal size, each sub-image corresponding to an imaging unit in the imaging system, and dividing each sub-image into N*N sub-regions of equal size, where N is an integer greater than or equal to 2; An imaging system including multiple imaging units for sequentially exposing and curing a photosensitive material layer by layer according to each of the original exposure images; A controller for moving the imaging system during the exposure and curing process of each printing layer, so that each imaging unit sequentially aligns with each sub-region in the sub-image according to a preset path, the preset path including at least one X-shaped route, wherein during the movement of the imaging system, the position of the sub-region aligned by each imaging unit in the sub-image is the same.

9. The stereolithography three-dimensional printing device according to claim 8, wherein, the image processing module is further configured to divide each sub-image into N rows by N columns of sub-regions of equal size according to rows and columns, and the preset path further includes a straight-line route along one of the rows or columns.

10. The stereolithography three-dimensional printing device according to claim 8, wherein, the imaging system includes an exposure light source, and the controller is further configured to control the turning on and off of the exposure light source.

11. The stereolithography three-dimensional printing device according to claim 10, wherein, the image processing module is further configured to generate N*N combined exposure images according to the original exposure image, including: sequentially assigning a serial number i to each sub-region in each sub-image according to the preset path, and the serial numbers of the sub-regions located at the same position in each sub-image are the same, where i is a positive integer less than or equal to N*N; and sequentially extracting the i-th sub-region image in each sub-region from each sub-image according to the order of the serial numbers and combining them to generate the i-th combined exposure image.

12. The stereolithography three-dimensional printing device according to claim 11, wherein, the controller is further configured to move the imaging system to a preset position in the preset path according to the preset path, load the combined exposure image corresponding to the preset position, and turn on the exposure light source in the imaging system to irradiate the photosensitive material according to the combined exposure image.

13. The stereolithography three-dimensional printing device according to claim 12, wherein, the imaging unit determines whether to irradiate the photosensitive material corresponding to the sub-region according to the combined exposure image.

14. The stereolithography three-dimensional printing device according to claim 12, wherein, after the irradiation of one combined exposure image is completed, the controller is further configured to turn off the exposure light source and move the imaging system to the next preset position.

Images