A rapid body prototyping light-curing DLP 3D printing system and method

Abstract

The present invention discloses a rapid body forming photocuring DLP 3D printing system and method, wherein the system comprises: a liquid tank sample stage, comprising a liquid tank, wherein the liquid tank is used to contain the photocuring solution required for the molding of the printing target object; a DLP display projection device, which is used to control the light source brightness and irradiation time corresponding to each pixel point in the projection light path to generate a projection pattern; an optical microscope, which is used to undertake the projection light path and to observe the structure of the printing target object; wherein the optical microscope is equipped with the liquid tank sample stage and connected to the DLP display projection device, and the projection pattern is projected to the liquid tank through the light path structure on the optical microscope. The present invention uses the difference in the projection grayscale of the light source image to accurately control the light source brightness and projection time, and produces different photocuring effects at different locations in one projection, achieving a more detailed and precise printing effect, and can be widely used in the fields of 3D printing and micro device processing technology.

Description

Technical Field

[0001] The present invention relates to the technical field of 3D printing and micro-device processing, and in particular to a rapid body prototyping light-curing DLP 3D printing system and method. Background Art

[0002] Additive manufacturing (AM) is a manufacturing technology that refers to the process of manufacturing objects by depositing materials layer by layer. 3D printing technology is a specific implementation of additive manufacturing. It is a rapidly developing technology that builds complex geometric features and structures by depositing materials layer by layer. Currently, common 3D printing technologies include fused deposition modeling, inkjet printing, selective laser sintering, and photocuring 3D printing. Among them, photocuring 3D printing technology has many advantages, including fast printing speed, high precision, and smooth surface of printed objects. Photocuring technology mainly includes stereolithography (SLA) and digital light processing (DLP).

[0003] SLA technology uses laser as a light source, and controls the laser beam to scan on the surface of the photosensitive polymer to cause local polymerization. DLP technology originated from SLA, using a projector or beam emitter as a light source, and by projecting a two-dimensional plane onto the surface of the photosensitive polymer, it uses a digital micro-mirror device (DMD) and a high-precision displacement platform to achieve micron-level resolution in a centimeter-level printing area. Compared with SLA, DLP technology has outstanding performance in printing resolution and printing speed, which can achieve faster and more precise design and ensure efficient production. Although the printing speed of DLP has increased compared to SLA, the printing time is still long. It takes several hours to print a smaller and simpler model, while larger and more complex models take longer to print.

[0004] DLP technology uses a layer-by-layer process to manufacture complex three-dimensional structures. First, a 3D model needs to be created using specialized 3D modeling software, then sent to the slicing software, where a dynamic bitmap image is produced by the DMD chip and projected onto the photosensitive mixture using ultraviolet light. The polymerization reaction is triggered by ultraviolet light, and the photosensitive mixture solidifies to form the shape of each layer of pattern. After the photopolymerization of each layer is completed, the printing manufacturing platform moves along the z-axis driven by the motor. The new image induces further photopolymerization until the 3D structure is completely printed.

[0005] Existing DLP printing technology requires the photosensitive material to be cured layer by layer, and only when layers are accumulated can a complete object be stacked up. The molding steps are numerous and the speed is relatively slow. Most existing light-curing printing technologies only use switch operations to control the light source, and do not use the adjustment of the light source intensity, so the utilization rate of the light source is low. When faced with fine structures at the microscopic scale, traditional DLP printing technology also has limitations, such as low printing accuracy and limited detail expression capabilities. The traditional DLP printing process requires the manufacturing platform to be lowered layer by layer to cooperate, and the equipment maintenance cost is high. Summary of the invention

[0006] In order to solve at least one of the technical problems existing in the prior art to a certain extent, the present invention aims to provide a rapid volume prototyping light-curing DLP 3D printing system and method.

[0007] The technical solution adopted by the present invention is:

[0008] A rapid body shaping light-curing DLP 3D printing system, comprising:

[0009] A liquid tank sample stage, comprising a liquid tank, wherein the liquid tank is used to contain a light-curing solution required for molding a printing target object;

[0010] DLP display projection device, used to control the brightness and illumination time of the light source corresponding to each pixel point in the projection light path to generate a projection pattern;

[0011] An optical microscope is used to undertake the projection light path and to observe the microstructure, phenomena and characteristics of the printed target object; wherein the optical microscope is equipped with the liquid tank sample stage and is connected to the DLP display projection device, and the projection pattern is projected to the liquid tank through the light path structure on the optical microscope to obtain a printed target object with a three-dimensional structure.

[0012] Furthermore, the liquid tank is made by attaching a rubber ring to a glass slide, and the area surrounded by the rubber ring forms a cavity with a boundary.

[0013] Furthermore, the DLP display projection device includes an optical structure and a control structure; the optical structure includes an illumination and imaging unit; the control structure includes a main control board, a driving board and a DMD driving board;

[0014] The lighting and imaging unit is used to generate and project light, and generally includes a light source and an optical system, which is used to ensure the brightness of the image and project the image into the liquid tank;

[0015] The main control board is used for overall control and management of the functions of the projection device, including communicating with the software, controlling switches, adjusting brightness, and sending control instructions;

[0016] The driving board is used to drive and control the light source and its electric components to ensure that they operate according to the set mode;

[0017] The DMD driver board is used to specifically control the micromirror array of the DMD chip in the DLP. The micromirror adjusts the reflection of light by changing its tilt angle, thereby realizing the display of images.

[0018] Furthermore, the optical microscope comprises a condenser unit, and the projection pattern generated by the DLP display projection device is focused by the condenser unit and then irradiated onto the liquid tank.

[0019] Furthermore, the liquid tank sample stage also includes a secondary focusing unit, which is arranged between the condenser unit and the liquid tank; the projection pattern is focused twice by the condenser unit and the secondary focusing unit in sequence, and then irradiated onto the liquid tank to achieve printing at a microscale.

[0020] Furthermore, the secondary focusing unit is obtained by:

[0021] A first liquid tank is made by using a first glass slide, and a microlens is obtained by printing in the first liquid tank by using the light-curing DLP 3D printing system;

[0022] After the first liquid tank is cleaned, the first glass slide provided with the microlens is used as a secondary focusing unit; light is incident from the plane of the first glass slide and emitted from the convex surface of the microlens to achieve focusing of the light.

[0023] Another technical solution adopted by the present invention is:

[0024] A rapid body shaping light-curing DLP 3D printing method comprises the following steps:

[0025] Prepare the photocurable solution required for printing the target object;

[0026] Acquire the three-dimensional features of the printing target object, convert the three-dimensional features of the printing object into a corresponding grayscale map, and generate a grayscale image;

[0027] Determine the light source brightness and irradiation time corresponding to the pixel point according to the grayscale image to obtain the projection pattern;

[0028] The projection pattern is projected onto the photocurable solution to achieve one-time projection printing of the target object.

[0029] Furthermore, the three-dimensional features of the printing target object include geometric property features and surface shape features of the printing target object;

[0030] The step of acquiring the three-dimensional features of the printing target object, converting the three-dimensional features of the printing object into a corresponding grayscale map, and generating a grayscale image includes:

[0031] Utilizing the difference in grayscale projection of the light source image and the different solidification growth effects caused by different grayscale values, z-channel rendering is used in the 3D modeling software to convert the three-dimensional features of the printed target object into corresponding grayscale mapping and generate a grayscale image.

[0032] Further, projecting the projection pattern onto the photocurable solution comprises:

[0033] Adjusting the objective lens of the optical microscope so that the objective lens is focused on the upper surface of the glass slide for holding the light-curing solution;

[0034] Project the projection pattern onto the glass slide, and adjust the light path of the optical microscope so that the projection pattern is aligned with the center of the field of view and the pattern is clear, so that the projection surface and the glass slide on the liquid tank sample stage are co-focused and coplanar.

[0035] Furthermore, the photocurable solution is prepared by the following method:

[0036] The photoinitiator and the photosensitive mixture are mixed according to a preset ratio to prepare a photocurable solution.

[0037] The beneficial effects of the present invention are: the present invention uses the difference in the grayscale of the light source image projection to accurately control the light source brightness and projection time, produces different light curing effects at different locations in one projection, and achieves a more detailed and precise printing effect. Compared with the traditional DLP layer-by-layer printing, the present invention can complete the printing of the entire three-dimensional object in one projection, avoiding the layer-by-layer stacking process, simplifying the pre-processing and printing process, and improving the molding speed and production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the embodiments of the present invention or the drawings of related technical solutions in the prior art are introduced below. It should be understood that the drawings introduced below are only for the convenience of clearly describing some embodiments of the technical solutions of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0039] Figure 1 It is a structural block diagram of a rapid body prototyping light-curing DLP 3D printing system in an embodiment of the present invention;

[0040] Figure 2 is a flowchart of the steps of a rapid body prototyping light-curing DLP 3D printing method in an embodiment of the present invention;

[0041] Figure 3 1 is a structural schematic diagram of a rapid body forming secondary focused light curing DLP 3D printing system according to an embodiment of the present invention;

[0042] Figure 4 It is a DLP projection pattern in an embodiment of the present invention and a real picture of the printing of different gray values ​​under a microscope (top view);

[0043] Figure 5 is a top view and a corresponding side view of a printed square object in an embodiment of the present invention;

[0044] Figure 6 is a schematic diagram of the influence of grayscale and irradiation time on printing height in an embodiment of the present invention;

[0045] Figure 7 It is the grayscale printing effect and detail diagram of the embodiment of the present invention;

[0046] Figure 8 is a schematic diagram of a grayscale printing microlens array and its imaging in an embodiment of the present invention;

[0047] Fig. 9 Schematic diagram of the secondary focusing printing principle of the microlens in an embodiment of the present invention.

[0048] Figure 3 Reference numerals: 1 - DLP control software; 2 - DLP host; 3 - reflector; 4 - mask; 5 - condenser system; 6 - stage; 7 - objective lens; 8 - camera; 9 - microlens; 10 - upper slide; 11 - lower slide. DETAILED DESCRIPTION

[0049] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and are not to be construed as limitations of the present invention. For the step numbers in the following embodiments, they are only provided for the convenience of explanation, and the order between the steps is not limited in any way, and the execution order of each step in the embodiment can be adaptively adjusted according to the understanding of those skilled in the art.

[0050] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., and orientations or positional relationships indicated are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0051] In the description of the present invention, the meaning of "several" is one or more, the meaning of "more" is two or more, and the meanings of "greater than", "less than", "exceed" and the like are understood as not including the number itself, and the meanings of "above", "below", "within" and the like are understood as including the number itself. If there is a description of the first and the second, it is only used for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features. In addition, "and / or" describes the association relationship of the associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the related objects before and after are in an "or" relationship.

[0052] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention in combination with the specific content of the technical solution.

[0053] Based on the limitations of the above existing technologies, the technical problems that the present invention needs to solve include improving the printing speed, improving the utilization rate of light sources, enhancing the fine structure printing capability, and reducing the equipment maintenance cost. The new technical solution should be committed to solving these problems to achieve fast, efficient and accurate volume forming light curing DLP 3D printing. In the first aspect, the present invention provides a rapid volume forming light curing DLP 3D printing system, which includes: a solution tank sample stage, an optical microscope and a DLP display projection device. Among them, the tank for placing the solution is made of a rubber ring attached to a glass slide, and the area surrounded by the rubber ring forms a bounded cavity for accommodating the photosensitive mixture solution required for the printing target object to be formed, and is exposed to the projection light source; the optical microscope is used to undertake the DLP projection light path, and is also used to observe the microstructure, phenomenon and characteristics of the printing target object; the DLP display projection device mainly includes optical and control parts, wherein the optical structure includes an illumination and imaging system, and the electrical control structure includes a main control board, a drive board and a DMD drive board; the DLP display projection device is specifically used to accurately control the light source brightness and irradiation time corresponding to each pixel in the projection. The optical microscope is equipped with a sample stage and connected to a DLP display projection device. The projection pattern generated by the DLP is projected onto the solution tank through the optical path structure on the optical microscope.

[0054] In the second aspect, the present invention proposes a rapid body shaping photocuring DLP 3D printing method, which includes: mixing a photoinitiator and a photosensitive mixture in a certain proportion to prepare a photosensitive mixture solution required for the printing target object; converting the three-dimensional features of the printing target object into a corresponding grayscale mapping and generating a planar grayscale image containing the three-dimensional features of the printing target object according to the geometric properties, surface shape and other characteristics of the printing target object; uploading the generated grayscale image to a DLP display projection device, utilizing the difference in the grayscale of the light source image projection, the light source photocuring cross-linking reaction at different locations, and different grayscale values ​​leading to different curing growth effects, thereby achieving the desired structure or pattern. By setting the exposure time of the DLP light source, projecting it onto the solution tank of the glass slide, a one-time projection printing of the target object is performed.

[0055] The following is a detailed explanation with reference to the accompanying drawings and specific embodiments.

[0056] like Figure 1 As shown, this embodiment provides a rapid body shaping light-curing DLP 3D printing system, which specifically includes:

[0057] A liquid tank sample stage, comprising a liquid tank, wherein the liquid tank is used to contain a light-curing solution required for molding a printing target object;

[0058] DLP display projection device, used to control the brightness and illumination time of the light source corresponding to each pixel point in the projection light path to generate a projection pattern;

[0059] An optical microscope is used to receive the projection light path and to observe the microstructure of the printed target object; wherein the optical microscope is equipped with the liquid tank sample stage and is connected to the DLP display projection device, and the projection pattern is projected to the liquid tank through the light path structure on the optical microscope to obtain a printed target object with a three-dimensional structure.

[0060] As an optional embodiment, a glass slide is used as a solution tank, and 5 to 20 microliters of photocurable solution is added using a pipette to print the target object, and the glass slide is placed on a microscope stage.

[0061] In this embodiment, the optical microscope used is an Olympus IX73 research-grade inverted microscope, which is used to observe the microstructure, phenomena and characteristics of the printed target object; the DLP display projection device chip used in this embodiment is PRO6500S, which is used to control the brightness and irradiation time of the light source in the projection, and the light path structure on the optical microscope can project the light vertically into the solution tank.

[0062] like Figure 2 As shown, this embodiment provides a rapid body shaping light-curing DLP 3D printing method, which includes the following steps:

[0063] Step 1: Preparation of photocurable solution: Polyethylene glycol diacrylate (molecular weight 700) and photoinitiator Darocur 1173 (chemical name 2-hydroxy-2-methylpropiophenone) were mixed in a ratio of 5:1 to prepare the material required for curing molding.

[0064] Step 2: 3D modeling and drawing: Model the 3D model of the target object on the SolidWorks software. Based on the geometric properties, surface shape and other features of the target object, use z-channel rendering in the 3D modeling software 3ds Max to convert the required 3D features of the object into corresponding grayscale mapping and generate a grayscale image.

[0065] Step 3: DLP software setting and image upload: Upload the generated grayscale image to the DLP display projection device through the supporting control software, and use the built-in grayscale mode of the software to control the light source brightness and irradiation time corresponding to the pixel point.

[0066] Step 4: Microscope adjustment and projection: Adjust the microscope objective lens to focus on the upper surface of the glass slide. Next, project the pattern of the DLP projection device onto the glass slide, and adjust the microscope light path so that the projected pattern is aligned with the center of the field of view and the pattern is clear. This will achieve the same focus and coplanarity between the projection surface and the glass slide on the sample stage.

[0067] Step 5: Slide treatment and solution coating: Add a sealing rubber ring to the cleaned and hydrophilic slide as a solution tank. Use a pipette to take 5 to 20 microliters of light-curing solution and drop it into the tank on the slide. Spin coating can be used to evenly coat the solution on the slide, and then place the slide on the microscope stage.

[0068] Step 6: Curing and cleaning: Through DLP projection of grayscale graphics, the printed target object is quickly cured in the liquid tank, and the uncured solution on the surface of the printed target object is washed away with alcohol to complete the printing process.

[0069] See also Figure 4 , Figure 4 Shown are top views taken under a microscope when square patterns with different grayscale values ​​were projected at the same exposure time. Figure 4In the figure, we can observe the changes in the curing effect of the photocurable solution under light of different grayscale values. When the grayscale is lower than 30%, the curing effect of the photocurable material is often insufficient, resulting in inconsistent width of the printed object. This is because the light intensity corresponding to the low grayscale value is low, and the photocuring rate and photosensitive properties of the photosensitive material are not fully utilized, thereby affecting its curing process and causing the width of the final printed object to be uneven. In order to reduce variables and optimize printing parameters in the experiment, we chose to start from a grayscale value of 30%. At this time, sufficient light intensity has been provided, so that the photocurable material can be cured evenly, avoiding the problem of insufficient curing.

[0070] See also Figure 5 , Figure 5 The printing of a single square using different grayscale values ​​(100%, 80%, 60%, 40%, 20%) and measuring its side height are demonstrated. The experiment found that the height of the printed object varies greatly in the lower grayscale range and changes slowly at higher grayscale values. The reason for this phenomenon, in addition to the influence of the cross-linking reaction characteristics of the photocurable solution, is also affected by the limited penetration depth of light. In the experiment, as the height of the printed object increases, the effect of light being absorbed and scattered in the resin will also increase. Since the light source is irradiated from above, the depth of light penetration into the interior of the cured object will decrease, resulting in a weakening of the curing effect, which will gradually slow down the growth rate of the object's height.

[0071] In DLP 3D printing, the grayscale and time of projection will affect the height and width of the printed object. Figure 6 , Figure 6 The experimental results of the printing height changing with the irradiation time (0.8s, 1s, 1.2s, 1.4s, 1.6s, 1.8s) under different grayscale settings (10%, 20%, 60%, 80%, 100%) are shown. Figure 6 It can be seen that at the same grayscale, the print height gradually increases with the increase of irradiation time. In addition, at low grayscale (such as 10%), the height difference is relatively low, which indicates that the activation efficiency of the photoinitiator is low under low light conditions. With the increase of grayscale (such as 20%, 40%, 60%), the growth rate of the print height is accelerated, showing a stronger photocuring reaction. At high grayscale (such as 80%, 100%), the print height increases rapidly in the initial stage, but the growth rate may slow down with further extension of irradiation time, which may be due to the depletion of photosensitive resin or saturation of photocuring process. The print height shows a positive correlation with both grayscale and irradiation time, that is, higher grayscale and longer irradiation time will lead to higher printed structures.

[0072] On the basis of achieving good grayscale control and differentiation of height, in addition to printing uniform planar structures, patterned grayscale shapes can also be used to prepare complex three-dimensional shapes and structures. Effects such as irregular curved surfaces, smooth gradients, and delicate engraved structures are displayed on the Figure 7 In this embodiment, grayscale patterns of lace, gears and diamonds with a sense of hierarchy are selected and projected and exposed through DLP technology. In each grayscale image, the darkest part is given a grayscale value of 30%, and the brightest part is given a grayscale of 100%, so that a structure with clear details can be printed at one time. Figure 7 The following is a detailed enlargement of the printed graphic with grayscale gradients. You can see the printed marks of the pixels on the surface of the object, as well as the changes in the depth of tones in different areas of the object, reflecting the details and layering, making the final visual effect three-dimensional.

[0073] Based on the above system, Figure 3 As shown, this embodiment also provides a rapid body forming secondary focused light curing DLP 3D printing system, which specifically includes:

[0074] The liquid tank sample stage comprises an upper glass slide and a lower glass slide, wherein the second surface of the upper glass slide is opposite to the first surface of the lower glass slide, a microlens is arranged on the second surface of the upper glass slide, and a photocurable solution is arranged on the first surface of the lower glass slide; the projection pattern is focused twice by a condenser unit and a secondary focusing unit in sequence, and then irradiated onto the liquid tank, so as to realize printing at a microscale;

[0075] DLP display projection device, used to control the brightness and illumination time of the light source corresponding to each pixel point in the projection light path to generate a projection pattern;

[0076] An optical microscope is used to receive the projection light path and to observe the microstructure of the printed target object; wherein the optical microscope is equipped with the liquid tank sample stage and is connected to the DLP display projection device, and the projection pattern is projected to the liquid tank through the light path structure on the optical microscope to obtain a printed target object with a three-dimensional structure.

[0077] As an optional embodiment, the microlenses on the upper glass are Figure 1 Furthermore, the good gradient effect produced by grayscale printing was used to print microlenses and their arrays, and imaging experiments were carried out. Figure 8 As shown, a 2×2 microlens array was printed by designing a pattern based on parameters such as the curvature of the lens, and the imaging capability of the microlens was observed through a microscope platform. A flower-shaped hollow mask was placed between the illumination light source and the microlens, and the array was observed from the convex surface of the lens using an objective lens connected to a camera. Clear flower patterns were observed, indicating that the microlens array prepared by grayscale printing has excellent array micro-imaging applications.

[0078] In addition, the optical focusing performance of the printed microlens is further applied. The propagation of rays passing through the microlens is simulated using the COMSOL optical ray module. Combined with the measured values ​​of the grayscale printed microlens parameters (arch height, chord length), the calculation and analysis based on geometric optics and ray optics theory show that the reduction factor of the microlens is about 3 to 12 times. Fig. 9 The schematic diagram of the secondary focusing equipment and optical path is shown. The ultraviolet light source of DLP is incident from the plane of the plano-convex lens. After the light is focused, it is irradiated onto the glass slide B coated with the curing liquid for further focused printing.

[0079] In summary, compared with the prior art, the present invention has at least the following advantages and beneficial effects:

[0080] (1) The present invention is based on grayscale adjustment light control technology, which uses the difference in grayscale of light source image projection to accurately control the brightness of the light source and the projection time, and produces different light-curing effects at different locations in a projection, thereby achieving a more detailed and precise printing effect. In traditional light-curing 3D printing, the control of the light source is often just a switch operation (simply controlling the switch on the mask), and the adjustment of the light intensity is not utilized. The grayscale adjustment light control technology adopted by the present invention first converts the required three-dimensional features of the printed object into corresponding grayscale mapping and generates a grayscale image based on the geometric properties, surface shape and other characteristics of the printed target object. Then, the difference in grayscale in the image is used to bring about different curing heights of the photocurable solution. By controlling the brightness of the light source and the projection time, different light-curing effects are achieved at pixel points with different grayscales.

[0081] (2) The present invention proposes a rapid body forming / one-time forming technology. Compared with the traditional DLP layer-by-layer printing, this technology analyzes the three-dimensional features of the printing target object, converts the required printing object into a corresponding grayscale mapping, and achieves the effect of one-time three-dimensional forming in a planar manner. The printing of the entire three-dimensional object is completed in one projection, avoiding the layer-by-layer stacking process, simplifying the preprocessing and printing process, and improving the forming speed and production efficiency.

[0082] (3) The present invention proposes secondary focusing technology and its application. As an innovative point of the present invention, a microlens for grayscale printing is introduced, and the secondary focusing technology is used in DLP 3D printing. By controlling the focus reduction, shape and energy density of the light spot with high precision, the printing precision is significantly improved. In general, the DLP 3D printing technology is effectively combined with the microscopic platform, and the secondary focusing printing technology is performed through the microlens to achieve high-precision printing at the microscale, which is used for the processing and manufacturing of micro-nano structures, and can meet the requirements for precision and detail in the fields of micro-device processing, biomedicine, etc.

[0083] (4) The printing system developed by the present invention utilizes a single DLP display projection device and the original microscopic optical path of an optical microscope to perform light source modulation and pattern projection, thereby reducing the difficulty of technical implementation, reducing costs, and improving application flexibility and convenience.

[0084] (5) The layer-by-layer printing of traditional DLP requires the manufacturing platform to be lowered in sequence, which makes the system structure more complicated and has high maintenance costs. The printing system developed by the present invention eliminates the need to build additional equipment required for the movement of the manufacturing platform, has a more compact structure, less mechanical wear, and a longer service life.

[0085] (6) The rapid body prototyping light-curing DLP 3D printing solution proposed in the present invention requires reasonable adjustment of the light intensity of the light source, and has a higher light source utilization rate compared to traditional light-curing 3D printing.

[0086] (7) The present invention has broad application prospects and strong development potential. It can realize high-precision, low-cost, rapid, large-format, three-dimensional automated processing. It is easy to commercialize and industrialize, and can be widely used and promoted in various industries.

[0087] In the above description of this specification, the description with reference to the terms "one embodiment / example", "another embodiment / example" or "certain embodiments / examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0088] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

[0089] The above is a specific description of the preferred implementation of the present invention, but the present invention is not limited to the above embodiments. Those skilled in the art may make various equivalent modifications or substitutions without violating the spirit of the present invention. These equivalent modifications or substitutions are all included in the scope defined by the claims of this application.

Claims

1. A rapid body shaping light-curing DLP 3D printing system, characterized in that: include: A liquid tank sample stage, comprising a liquid tank, wherein the liquid tank is used to contain a light-curing solution required for molding a printing target object; DLP display projection device, used to control the brightness and illumination time of the light source corresponding to each pixel point in the projection light path to generate a projection pattern; An optical microscope is used to undertake the projection light path and to observe the structure of the printed target object; wherein the optical microscope carries the liquid tank sample stage and is connected to the DLP display projection device, and the projection pattern is projected to the liquid tank through the light path structure on the optical microscope.

2. A rapid body prototyping light-curing DLP 3D printing system according to claim 1, characterized in that: The liquid tank is made by sticking a rubber ring on a glass slide, and the area surrounded by the rubber ring forms a cavity with a boundary.

3. The rapid body prototyping light-curing DLP 3D printing system according to claim 1, characterized in that: The DLP display projection device comprises an optical structure and a control structure; the optical structure comprises an illumination and imaging unit; the control structure comprises a main control board, a driving board and a DMD driving board.

4. The rapid body prototyping light-curing DLP 3D printing system according to claim 1, characterized in that: The optical microscope comprises a condenser unit, and the projection pattern generated by the DLP display projection device is focused by the condenser unit and then irradiated onto the liquid tank.

5. The rapid body prototyping light-curing DLP 3D printing system according to claim 4, characterized in that: The liquid tank sample stage also includes a secondary focusing unit, which is arranged between the condenser unit and the liquid tank; the projection pattern is focused twice by the condenser unit and the secondary focusing unit in sequence, and then irradiated onto the liquid tank to achieve micro-scale printing.

6. The rapid body prototyping light-curing DLP 3D printing system according to claim 5, characterized in that: The secondary focusing unit is obtained by: A first liquid tank is made by using a first glass slide, and a microlens is obtained by printing in the first liquid tank by using the light-curing DLP 3D printing system; After the first liquid tank is cleaned, the first glass slide provided with the microlens is used as a secondary focusing unit; light is incident from the plane of the first glass slide and emitted from the convex surface of the microlens to achieve focusing of the light.

7. A rapid body shaping light-curing DLP 3D printing method, characterized in that: The following steps are involved: Prepare the photocurable solution required for printing the target object; Acquire the three-dimensional features of the printing target object, convert the three-dimensional features of the printing object into a corresponding grayscale map, and generate a grayscale image; Determine the light source brightness and irradiation time corresponding to the pixel point according to the grayscale image to obtain the projection pattern; The projection pattern is projected onto the photocurable solution to achieve one-time projection printing of the target object.

8. The rapid body prototyping light-curing DLP 3D printing method according to claim 7, characterized in that: The three-dimensional features of the printing target object include geometric property features and surface shape features of the printing target object; The step of acquiring the three-dimensional features of the printing target object, converting the three-dimensional features of the printing object into a corresponding grayscale map, and generating a grayscale image includes: Utilizing the difference in grayscale projection of the light source image and the different solidification growth effects caused by different grayscale values, z-channel rendering is used in the 3D modeling software to convert the three-dimensional features of the printed target object into corresponding grayscale mapping and generate a grayscale image.

9. The rapid body prototyping light-curing DLP 3D printing method according to claim 7, characterized in that: The projecting pattern onto the photocurable solution comprises: Adjusting the objective lens of the optical microscope so that the objective lens is focused on the upper surface of the glass slide for holding the light-curing solution; The projection pattern is projected onto a glass slide, and the optical path of the optical microscope is adjusted so that the projection pattern is aligned with the center of the field of view, so that the projection surface is co-focused and coplanar with the glass slide on the liquid tank sample stage.

10. The rapid body prototyping light-curing DLP 3D printing method according to claim 7, characterized in that: The photocurable solution is prepared by the following method: The photoinitiator and the photosensitive mixture are mixed according to a preset ratio to prepare a photocurable solution.

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