CN114147959A

CN114147959A - 3D printing method and 3D printing equipment for continuous growth

Info

Publication number: CN114147959A
Application number: CN202010931321.9A
Authority: CN
Inventors: 朱鸣; 徐顺达; 吕帅; 朱鹏飞; 浦东林
Original assignee: Suzhou University; SVG Tech Group Co Ltd
Current assignee: Suzhou University; SVG Tech Group Co Ltd
Priority date: 2020-09-07
Filing date: 2020-09-07
Publication date: 2022-03-08
Anticipated expiration: 2040-09-07

Abstract

The invention discloses a 3D printing method for continuous growth, which comprises the following steps: modeling; generating slices, and slicing the three-dimensional model in the Z-axis direction; converting, namely converting each slicing model picture into a slicing bitmap; the first data uploading, the data processing module uploads the first N × M bitmap files to the N sub-memories; printing, wherein the control module controls the objective table to continuously move at a constant speed, simultaneously controls the sub-memories to continuously refresh the slice bitmaps to continuously print according to actual conditions, controls the next sub-memory to refresh the slice bitmaps to print when the printing of the M slice bitmaps in the previous sub-memory is finished, controls the data transmission module to upload new M bitmaps to the previous sub-memory, and repeats until K slice bitmaps finish printing. The invention also discloses 3D printing equipment, and continuous printing is realized by adopting the continuous growth 3D printing method. By the method, continuous printing is realized, and printing time is saved.

Description

3D printing method and 3D printing equipment for continuous growth

Technical Field

The invention relates to the technical field of 3D, in particular to a continuously-growing 3D printing method and 3D printing equipment.

Background

The 3D printing technology is used as a prospective and strategic technology and has important application in the high-end fields of aerospace, biomedical, weaponry, automobiles, molds and the like. In the field of biological medical treatment, the 3D printing technology provides a new flexible preparation method for biochips and biochemical devices, also provides a new research means and platform for the fields of biological materials and artificial organs, and realizes the manufacture of complex 3D carrier supports. However, the existing 3D printing technology cannot realize a continuous growth printing mode during printing, and thus the time required is long; meanwhile, the existing 3D printing technology is still difficult to meet the application requirements on printing precision and printing breadth.

The foregoing description is provided for general background information and is not admitted to be prior art.

Disclosure of Invention

The invention aims to provide a continuous growth 3D printing method and a 3D printing device capable of continuously printing.

The invention provides a continuous growth 3D printing method, and equipment for realizing the continuous growth 3D printing method comprises a data processing module, a control module, a storage module with N sub memories, a data transmission module and a printing module with an objective table, wherein the method comprises the following steps:

modeling, namely establishing a three-dimensional model for the object to be printed;

generating slices, and slicing the three-dimensional model in the Z-axis direction by using the data processing module to obtain K slice model images;

converting, namely converting each slicing model graph into a slicing bitmap to form a slicing bitmap file set with K slicing bitmaps;

uploading initial data, uploading the front N × M bitmap files in the slice bitmap file set to the N sub-memories through the data processing module, wherein M pieces of slice bitmap data can be stored in each sub-memory, and N × M is not more than K;

and printing, wherein the control module controls the object stage to move continuously, controls the sub-memories to continuously refresh the slice bitmaps to continuously print according to actual conditions, controls the next sub-memory to refresh the slice bitmaps to print when the printing of the M slice bitmaps in the previous sub-memory is finished, controls the data transmission module to upload new M slice bitmaps to the previous sub-memory, and repeats the process until the printing of the K slice bitmaps is finished.

In one embodiment, the K slice model maps have the same or different thicknesses, and the thicker the slice model map is, the slower the control module controls the stage to move.

In one embodiment, when the thicknesses of the slice model maps are the same, the control module controls the object stage to move continuously at a constant speed; when the thicknesses of the slice model images are different, the control module controls the moving speed of the object stage to be different.

In one embodiment, the apparatus for implementing the continuous-growth 3D printing method further includes a signal transmission module, the signal transmission module triggers a signal through displacement of the object stage, the control module includes a system control unit and a motion control unit, the storage module sends a signal to the system control unit after completing uploading of N × M slice bitmaps, the system control unit receives a data upload completion signal and sends an instruction to the motion control unit, the motion control unit controls the object stage to start moving, the object stage triggers the signal transmission module to send a signal to the system control unit when moving, the system control unit receives the signal and sequentially controls the sub-memories to refresh one slice bitmap, and the motion control unit controls a motion speed of the object stage according to a thickness of the slice bitmap, the printing module prints according to the slicing bitmap, when the moving distance S of the objective table is the thickness of the slicing bitmap, the signal transmission module is triggered to send a signal to the system control unit, and the system control unit receives the signal and controls the sub-memory to refresh a new slicing bitmap; and when the moving distance of the object stage is S x M, the system control unit controls the next sub-memory to refresh the slice bitmap, and simultaneously controls the data processing module to upload new M slice bitmaps to the previous sub-memory.

The present invention also provides a 3D printing apparatus, comprising:

the data processing module is used for establishing a three-dimensional model of an object to be printed, cutting the object into K slice model images and then cutting the K slice model images;

a data transmission module for transmitting the slice bitmap;

the storage module comprises N sub memories and is used for storing the K slice bitmaps into the N sub memories in batches according to the sequence, wherein M slice bitmaps are stored in each sub memory;

the printing module comprises an object stage and is used for printing on the object stage according to the slice bitmap;

the control module controls the object stage to move continuously, controls the sub-memories to refresh the slice bitmaps continuously to print continuously according to actual conditions, controls the next sub-memory to refresh the slice bitmaps to print each time the previous M slice bitmaps in the sub-memories are printed, and controls the data transmission module to upload new M bitmaps to the previous sub-memory, and the process is repeated until the K slice bitmaps are printed.

In one embodiment, the printing module further comprises a resin tank for containing resin liquid and an optical mechanism, the objective table can extend into the resin tank, the optical mechanism comprises a light source, a DMD light modulator and a miniature lens barrel, the light source emits light to the DMD light modulator, the DMD light modulator receives the pattern information and modulates the received light, and the miniature lens barrel zooms and projects the light modulated by the DMD light modulator into the resin tank so as to cure and mold the resin liquid above the objective table;

in one embodiment, a light-transmitting and air-permeable film is disposed on the resin tank to cover the resin liquid, the optical mechanism has a focusing surface, and the optical mechanism further includes a laser sensor disposed on one side of the micro-lens barrel, the laser sensor is configured to detect a distance between the laser sensor and the light-transmitting and air-permeable film, so that the focusing surface is located on a lower surface of the light-transmitting and air-permeable film.

In one embodiment, the control module includes a system control unit and a motion control unit, the system control unit controls the data transmission module to transmit the slice bitmap to the data storage module and controls the sub-memory to refresh the slice bitmap, and the motion control unit drives the stage to move relative to the resin tank.

In one embodiment, the 3D printing apparatus further includes a lifting mechanism for driving the optical mechanism and/or the resin tank to change a distance between the optical mechanism and the resin tank.

In one embodiment, the lifting mechanism includes a first lifting mechanism for driving the optical mechanism to move relative to the resin tank and a second lifting mechanism for driving the resin tank to move relative to the optical mechanism.

The 3D printing method for continuous growth can utilize the control module to control the objective table to continuously move, and meanwhile, the control module controls the sub-memory to continuously refresh the slice bitmap for continuous printing according to actual conditions, so that continuous printing is realized, and printing time is saved.

Drawings

FIG. 1 is a flow chart of the steps of a continuous growth 3D printing method according to an embodiment of the present invention;

FIG. 2 is a schematic structural diagram of a 3D printing apparatus according to an embodiment of the present invention;

FIG. 3 is a schematic view of a portion of the structure of FIG. 2

Fig. 4 is a top view of fig. 3.

Detailed Description

The following detailed description of embodiments of the present invention is provided in connection with the accompanying drawings and examples. The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.

First embodiment

Referring to fig. 1, a continuous growth 3D printing method according to a first embodiment of the present invention includes a data processing module, a control module, a storage module having N sub-memories, a data transmission module, and a printing module having a stage, and includes the following steps:

s1: modeling, namely establishing a three-dimensional model for the object to be printed;

s2: generating slices, and slicing the three-dimensional model in the Z-axis direction by using the data processing module to obtain K slice model images;

s3: converting, namely converting each slicing model graph into a slicing bitmap to form a slicing bitmap file set with K slicing bitmaps;

s4: uploading initial data, and uploading the first N × M bitmap files in the slice bitmap file set to the N sub-memories through the data transmission module, wherein each sub-memory can store M pieces of slice bitmap data, and N × M < K;

s5: and printing, wherein the control module controls the object stage to continuously move at a constant speed, simultaneously controls the sub-memories to continuously refresh the slice bitmaps to continuously print according to actual conditions, and controls the next sub-memory to refresh the slice bitmaps to print when the printing of the M slice bitmaps in the previous sub-memory is finished, and simultaneously controls the data transmission module to upload new M bitmaps to the previous sub-memory, and the process is repeated until the printing of the K slice bitmaps is finished.

In the present embodiment, the actual condition is the distance S that the stage moves when each slice model map is completed, that is, the thickness of each slice model map (slice bitmap).

In step S1, a 3D model is created for the object to be printed using modeling software or the like.

In step S2, the 3D model data to be printed is imported into a data processing module, and the data processing module performs Z-direction (i.e., height-direction) hierarchical segmentation on the 3D model to form K slice model maps. The slice model map comprises pattern information and slice height of each slice, so that high-precision printing can be realized. The thickness values of the layers are set according to the actual working capacity of the printing module, and the specific thickness values are set as follows.

Since the printing rate of the printing module is constant during the printing of the K slice model maps. Thus, the data processing module determines the thickness of each slice model map according to the cross-sectional area of each slice model map to determine the stage displacement S upon completion of each slice map.

When the cross-sectional areas of the slice model maps are less different, the thicknesses of the slice model maps are the same. The smaller difference in the cross-sectional areas can be embodied by the fact that the moving distance of the printing module in the horizontal two-dimensional direction (i.e., the X, Y direction) is smaller, that is, the time for the printing module to move in the horizontal two-dimensional direction is shorter.

When the cross-sectional areas of the slice model images are greatly different, the thicknesses of the slice model images are different. The larger difference in the cross-sectional areas can be embodied by the fact that the printing module moves a larger distance in the horizontal two-dimensional direction (i.e., the direction X, Y), that is, the printing module moves in the horizontal two-dimensional direction for a longer time.

In step S3, the data processing module includes a graphics processing unit. And generating an image consisting of a contour line by using the slice model diagram by using an image processing unit, and performing gray scale processing to form K slice bitmaps.

Specifically, a set gray threshold is adopted, and then an edge contour line is extracted by using a graphic processing unit; and when the gray value of the adjacent pixel points in the layered scanning image reaches a preset gray threshold, determining the gray value as an edge contour point, thereby determining the edge contour line. And corresponding printing data are produced according to the edge contour lines required to be printed by all the slice bitmaps so as to form a slice bitmap file set with K slice bitmaps. And simultaneously sending the slice bitmap file set to a data transmission module. Wherein K is an integer greater than 1; the thickness of each slice bitmap is the same as the thickness of the corresponding slice model map.

In step S5, the apparatus for implementing the continuous growth 3D printing method further includes a signal transmission module that triggers a signal through displacement of the stage. When the objective table starts to move, the trigger signal transmission module sends a signal to the control module; the control module controls the sub-memory to refresh the slice bitmap; when the object stage moves for a distance S (namely the thickness of the slice model picture), the trigger signal transmission module sends a signal to the control module, and the control module controls the sub-memory to refresh a new slice bitmap.

Specifically, the control module includes a system control unit and a motion control unit. And the storage module uploads the first M x N (N and M are integers more than 1) slice bitmaps in the K slice bitmaps and then sends signals to the system control unit. The system control unit receives the data uploading completion signal, turns on the light source and sends an instruction to the motion control unit; the motion control unit controls the object stage to start to move; a motion trigger signal transmission module of the objective table sends a signal to a system control unit, and the system control unit receives the signal and sequentially controls the sub-memories to refresh a slice bitmap; the print module begins printing according to the slice bitmap. The objective table continues to move; and the system control unit reads the moving position of the object stage in real time through the motion control unit. When the objective table moves for a distance S, the objective table triggers the signal transmission module again to send a signal to the system control unit; at this point, the stage continues to move downward at a constant speed. The system control unit receives the signal and controls the sub-memory to refresh a new slice bitmap; and repeating the method until the printing of the M slice bitmaps in the sub memory is finished. Thereby enabling continuous updating of the slice bitmap. Wherein, the thicker the thickness of the slice bitmap (i.e. slice model map), the slower the control module controls the moving speed of the object stage. Namely, when the thicknesses of all the slicing bitmaps are the same, the motion control unit controls the object stage to move at a constant speed; when the thicknesses of the slice bitmaps are different, the motion control unit controls the moving speed of the object stage according to the thicknesses of the slice bitmaps, namely, when the thicknesses of the slice bitmaps are different, the motion control unit controls the moving speed of the object stage to be different.

When the moving distance of the object stage is S x M, printing of M slice bitmaps in the previous sub memory is finished; and the system control unit controls the storage module to enter the refreshing of the M slice bitmaps in the next sub-memory according to the printing sequence and controls the refreshing of the M slice bitmaps in the next sub-memory according to the method. And simultaneously, the system control unit informs the data processing module to upload new M slice bitmaps to the previous sub-memory. This method is repeated until the transmission of K slice bitmaps is completed. The N sub memories are not idle in the printing process, and continuous printing is guaranteed. In the process, the motion control unit always controls the objective table to move downwards at a constant speed, so that continuous high-precision printing is realized.

In this embodiment, printing is realized by adopting a light curing mode, and high-precision printing can be realized.

Second embodiment

The difference between the continuous growth 3D printing method provided by the second embodiment of the present invention and the first embodiment is that in this embodiment, the information transmission device sends a signal through a time trigger, that is, the data processing module determines the printing time T of each slice model map according to the cross-sectional area of each slice model map to determine the moving time T of the stage when each slice model map is completed.

For the embodiment, the signal transmission module sends a signal through the time T for completing the slicing bitmap, when the signal transmission module sends the signal to the control module, the control module controls the sub-memory to refresh the slicing bitmap, and the objective table starts to move; and when the moving time of the objective table is T, the signal transmission module sends a signal to the control module, and the control module controls the sub-memory to refresh a new slice bitmap.

Specifically, the control module includes a system control unit and a motion control unit.

In step S5, the storage module triggers the signal transmission module to send a signal to the system control unit after uploading N × M slice bitmaps. The system control unit receives the data uploading completion signal, turns on the light source and sends an instruction to the motion control unit; the motion control unit controls the objective table to start to move, and simultaneously the system control unit controls the sub memories to refresh a slice bitmap according to the sequence; and the printing module prints according to the slice bitmap. The objective table continues to move; the system control unit reads the moving time of the object stage in real time through the motion control unit. When the moving time of the object stage reaches T, the trigger signal transmission module sends a signal to the system control unit, and the system control unit receives the signal and controls the sub-memory to refresh a new slice bitmap.

When the moving time of the object stage is T × M, printing of M slice bitmaps in the previous sub memory is completed; and the system control unit controls the storage module to enter the refreshing of the M slice bitmaps in the next sub-memory according to the printing sequence and controls the refreshing of the M slice bitmaps in the next sub-memory according to the method. And simultaneously, the system control unit informs the data processing module to upload new M slice bitmaps to the previous sub-memory. This method is repeated until the transmission of K slice bitmaps is completed. The N sub memories are not idle in the printing process, and continuous printing is guaranteed. In the process, the motion control unit always controls the objective table to move downwards at a constant speed, so that continuous printing with large cross section area and high precision is realized.

An embodiment of the present invention further provides a 3D printing apparatus, including:

the data processing module is used for establishing a three-dimensional model for the object to be printed, cutting the three-dimensional model into K slice model diagrams, and generating K slice bitmaps from the K slice model diagrams;

a data transmission module for transmitting the slice bitmap;

The 3D printing apparatus 100 in this embodiment implements continuous 3D printing by using the continuously generated 3D printing method described above.

The actual condition is the thickness of each slice bitmap. The thickness is converted from the thickness of the corresponding slice model map.

The data processing module can be a computer loaded with operation software for processing image processing, judgment and the like.

The control module comprises a system control unit and a motion control unit, the system control unit controls the data transmission module to transmit the slice bitmap to the data storage module and controls the sub-memory to refresh the slice bitmap, and the motion control unit drives the objective table to move.

The printing module comprises a resin tank 2 for containing resin liquid 25 and an optical mechanism 1 for emitting light to cure and mold the resin liquid 25 above the objective table 3; wherein the object stage 3 extends into the resin tank 2, and the motion control unit drives the object stage to move relative to the resin tank. The optical mechanism 1 comprises a light source 11, a DMD (digital micromirror device) light modulator 12 and a miniature lens barrel 13, wherein the light source 11 emits light to the DMD light modulator 12, the DMD light modulator 12 receives the pattern information and modulates the received light, and the miniature lens barrel 13 zooms and projects the light modulated by the DMD light modulator 12 into the resin tank 2 so as to cure and mold the resin liquid 25 above the objective table 3. To facilitate the miniature lens barrel 13 to project the light in a zoom manner. In this embodiment, the DMD light modulator 12 is disposed above the micro lens barrel 13, and the light source 11 may be disposed on one side or above the DMD light modulator 12. The motion control unit 4 can drive the object stage 3 to move up and down and can also drive the object stage 3 to move left and right.

The resin tank 2 is provided with a light-transmitting breathable film 23 for shielding the resin liquid 25 and a transparent tank cover 21 connected with the light-transmitting breathable film 23 through a fastener 22. The transparent tank cover 21 is used for fixing the light-transmitting and air-permeable film 23 above the resin liquid 25, so that the effect of forming a flat liquid level can be achieved, and the quality of the printed 3D model is improved. The transparent slot cover 21 is disposed above the light-transmitting and breathable film 23.

In this embodiment, the transparent cover 21 has a hollow portion 27 and an edge portion 26 surrounding the hollow portion 27, and the light-transmitting breathable film 23 is connected to the edge portion 26 and fixed by a fastener 22. The fasteners 22 are conventional screws and will not be described in detail herein. Indeed, in other embodiments, the transparent slot cover 21 may be directly covered on the light-transmitting and air-permeable film 23 without providing the hollow portion 27, and is not particularly limited herein, depending on the actual situation. The transparent slot cover 21 can be concave, and can also be in other shapes according to the actual situation.

An opening 24 is arranged on the resin tank 2 to enable the object stage 3 to extend into the resin tank 2, and the opening 24 is arranged on one side of the transparent tank cover 21, namely, the transparent tank cover 21 does not completely cover the resin tank 2. Indeed, in other embodiments, the transparent slot cover 21 may be disposed on the resin slot 2 to completely cover the resin slot 2, and the side of the resin slot 2 is provided with an opening 24 for allowing the object stage 3 to enter, which is not specifically limited herein, but only needs to enable the object stage 3 to extend into the resin slot 2.

The optical mechanism 1 has a focus plane, specifically, the optical mechanism 1 has a focus plane, the optical mechanism 1 further includes a laser sensor 14 disposed at one side of the micro-lens barrel 13, and the laser sensor 14 is configured to detect a distance between the laser sensor 14 and the light-transmitting and breathable film 23, so that the focus plane is located on a lower surface 232 of the light-transmitting and breathable film 23. That is, when the focus plane is located at the lower surface 232 of the light-transmitting breathable film 23, an optimal focusing distance f is formed between the micro-lens barrel 13 and the light-transmitting breathable film 23, and accordingly, the distance between the laser sensor 14 and the light-transmitting breathable film 23 can also be obtained, and the distance d between the laser sensor 14 and the light-transmitting breathable film 23 is recorded and maintained, so that the focus plane is located at the lower surface 232 of the light-transmitting breathable film 23. In order to more accurately detect the distance between the focusing surface 131 and the light-transmitting and air-permeable film 23, the laser sensor 14 and the micro-lens barrel 13 are both moved in the vertical direction. When the light-transmitting air-permeable film 23 is deformed, the distance between the laser sensor 14 and the light-transmitting air-permeable film 23 is also changed to d ', and in order to maintain the optimal focusing distance f between the micro-lens barrel 13 and the light-transmitting air-permeable film 23, the elevating mechanism drives the resin tank 2 to move downward by the distance d-d'. Since the light-transmitting gas-permeable film 23 has gas permeability, the resin liquid 25 in contact with the lower surface 232 thereof can be prevented from being cured (the resin liquid 25 is an anaerobically curable resin liquid 25, and the surface in contact with oxygen is prevented from being cured).

The printing module further comprises a lifting mechanism for driving the optical mechanism 1 and/or the resin tank 2 to change the distance between the optical mechanism 1 and the resin tank 2.

In this embodiment, the lifting mechanism includes a first lifting mechanism 5 for driving the optical mechanism 1 to move relative to the resin tank 2 and a second lifting mechanism 6 for driving the resin tank 2 to move relative to the optical mechanism 1. The data processing module can control the first lifting mechanism 5 and the second lifting mechanism 6 to operate simultaneously to change the distance between the resin tank 2 and the optical mechanism 1, or control either one of them, which is not specifically limited herein, depending on the actual situation. Indeed, in other embodiments, one lifting mechanism may be provided, which is connected to the optical mechanism or the resin tank. The laser sensor 14 detects a distance value between the micro lens barrel 13 and the resin tank 2 mechanism, and sends a detected result to the data processing module, and the data processing module judges whether the distance between the resin tank 2 and the optical mechanism 1 needs to be adjusted according to the result.

In the drawings, the size and relative sizes of layers and regions may be exaggerated for clarity. It will be understood that when an element such as a layer, region or substrate is referred to as being "formed on," "disposed on" or "located on" another element, it can be directly on the other element or intervening elements may also be present. In contrast, when an element is referred to as being "directly formed on" or "directly disposed on" another element, there are no intervening elements present.

In this document, unless expressly stated or limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms can be understood in a specific case to those of ordinary skill in the art.

In this document, the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", "vertical", "horizontal", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for the purpose of clarity and convenience of description of the technical solutions, and thus, should not be construed as limiting the present invention.

As used herein, the ordinal adjectives "first", "second", etc., used to describe an element are merely to distinguish between similar elements and do not imply that the elements so described must be in a given sequence, either temporally, spatially, in ranking, or in any other manner.

As used herein, the meaning of "a plurality" or "a plurality" is two or more unless otherwise specified.

It will be understood by those skilled in the art that all or part of the steps of implementing the above method embodiments may be implemented by hardware associated with program instructions, and the program may be stored in a data processing module readable storage medium, and when executed, performs the steps including the above method embodiments. The foregoing storage medium includes: various media that can store program codes, such as ROM, RAM, magnetic or optical disks.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

As used herein, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, including not only those elements listed, but also other elements not expressly listed.

The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present invention, and all the changes or substitutions should be covered within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the appended claims.

Claims

1. A3D printing method for continuous growth is characterized in that equipment for realizing the 3D printing method for continuous growth comprises a data processing module, a control module, a storage module with N sub memories, a data transmission module and a printing module with a stage, and the method comprises the following steps:

2. The continuous-growth 3D printing method according to claim 1, wherein the K slice model maps have the same or different thicknesses, and the thicker the slice model map is, the slower the control module controls the stage to move.

3. The continuous-growth 3D printing method according to claim 2, wherein when the thickness of each slice model map is the same, the control module controls the stage to move continuously at a constant speed; when the thicknesses of the slice model images are different, the control module controls the moving speed of the object stage to be different.

4. The 3D printing method of claim 1, wherein the apparatus for implementing the 3D printing method further comprises a signal transmission module, the signal transmission module triggers a signal through the displacement of the stage, the control module comprises a system control unit and a motion control unit, the storage module sends a signal to the system control unit after uploading N × M slice bitmaps, the system control unit receives a data upload completion signal and sends a command to the motion control unit, the motion control unit controls the stage to start moving, the signal transmission module is triggered to send a signal to the system control unit when the stage moves, the system control unit receives the signal and controls the sub-memories to refresh one slice bitmap in sequence, the motion control unit controls the motion speed of the objective table according to the thickness of the slice bitmap, the printing module prints according to the slice bitmap, when the moving distance S of the objective table is the thickness of the slice bitmap, the signal transmission module is triggered to send a signal to the system control unit, and the system control unit receives the signal and controls the sub-memory to refresh a new slice bitmap; and when the moving distance of the object stage is S x M, the system control unit controls the next sub-memory to refresh the slice bitmap, and simultaneously controls the data processing module to upload new M slice bitmaps to the previous sub-memory.

5. A3D printing apparatus, comprising:

the data processing module is used for establishing a three-dimensional model for the object to be printed, cutting the three-dimensional model into K slice model images and then cutting the K slice model images;

a data transmission module for transmitting the slice bitmap;

the control module controls the objective table to continuously move, and simultaneously controls the sub-memory to continuously refresh the slice bitmap for continuous printing according to actual conditions; and when the printing of the M slice bitmaps in the previous sub memory is finished, the control module controls the next sub memory to refresh the slice bitmaps for printing, and controls the data transmission module to upload new M bitmaps to the previous sub memory, and the process is repeated until the printing of the K slice bitmaps is finished.

6. The 3D printing apparatus according to claim 5, wherein the printing module further comprises a resin tank for containing a resin liquid, the stage is extendable into the resin tank, and the optical mechanism comprises a light source, a DMD light modulator and a micro-lens barrel, the light source emits light to the DMD light modulator, the DMD light modulator receives the pattern information and modulates the received light, and the micro-lens barrel scales and projects the light modulated by the DMD light modulator into the resin tank to cure and mold the resin liquid above the stage.

7. The 3D printing apparatus according to claim 6, wherein a light-transmissive gas-permeable film is disposed on the resin tank to cover the resin liquid, the optical mechanism has a focusing surface, and the optical mechanism further includes a laser sensor disposed at a side of the micro-lens barrel, the laser sensor being configured to detect a distance between the laser sensor and the light-transmissive gas-permeable film such that the focusing surface is located on a lower surface of the light-transmissive gas-permeable film.

8. The 3D printing device according to claim 6, wherein the control module includes a system control unit that controls the data transfer module to transfer the slice bitmap to the data storage module and controls the sub memory to refresh the slice bitmap, and a motion control unit that drives the stage to move relative to the resin tank.

9. The 3D printing apparatus according to claim 6, wherein the 3D printing apparatus further comprises a lifting mechanism to drive the optical mechanism and/or the resin vat to change a distance between the optical mechanism and the resin vat.

10. The 3D printing apparatus according to claim 9, wherein the elevating mechanism includes a first elevating mechanism that drives the optical mechanism to move compared to the resin tank and a second elevating mechanism that drives the resin tank to move compared to the optical mechanism.