A 3D printing method and a 3D printing system

Abstract

A 3D printing method and system include an image system that establishes a 3D digital model and cuts the 3D digital model into an image sequence, a control system, a light engine that receives a series of images and modulates a light source for controlled projection onto a surface to be printed, a projection lens that is arranged in correspondence with the light engine and is controlled to perform projection, a printing platform, a resin tank, a light-transmitting film, and a rotating film release mechanism arranged in correspondence with the light-transmitting film. The rotating film release mechanism includes: a film clamp that fixes the light-transmitting film, a driving mechanism that drives the film clamp to move, a driving transmission mechanism driven by the driving mechanism and connected to the film clamp, and a film clamp guiding mechanism arranged in correspondence with the driving transmission mechanism to guide the movement of the film clamp. The light engine and the projection lens cooperate to control the magnification size of pixels and focus light onto the printing surface. The above-mentioned printing method and system separate the light-transmitting film from the printing component through the peeling action of the rotating film release mechanism, overcomes the excessive adhesion between the film and the component caused by the existing pulling action, and improves the success rate of 3D printing.

Description

Technical Field

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

[0002] Stereolithography was originally conceived as a rapid prototyping technology. Rapid prototyping encompasses a range of techniques that can be used to create realistic scale models of production components directly from computer-aided designs (CAD) in a rapid manner (much faster than previously possible). Since its disclosure in U.S. Patent 4,575,330, stereolithography has greatly helped engineers visualize complex three-dimensional part geometries, detect errors in prototype schematics, test critical components, and verify theoretical designs at a relatively low cost and in a much faster timeframe than previously possible.

[0003] Over the past few decades, continuous investment in the field of micro-electro-mechanical systems (MEMS) has led to the emergence of micro-stereolithography (μSL), which inherits the basic principles of traditional stereolithography but has higher spatial resolution. For example, K Ikuta and K. Hirowatari, "True three-dimensional microfabrication using stereolithography and metal molding", 6th IEEE Microelectromechanical Systems Symposium in 1993, with the assistance of single-photon polymerization and two-photon polymerization technology, the resolution of micro-stereolithography was further enhanced to less than 200nm; for example, S. Maruo and K. Ikuta, "Three-dimensional microfabrication by polymerization using single-photon absorption", Appl. Phys. Lett., vol. 76, 2000; S. Maruo and S. Kawata, "Two-photon absorption near-infrared photopolymerization for three-dimensional microfabrication", J. MEMS, vol. 7, pp. 411, 1998; S. Kawata, HB Sun, T. Tanaka and K. Takada, "Fine features of functional microdevices", Nature, vol. 412, p. 697, 2001.

[0004] The invention of projection microstereolithography (PμSL) by Bertsch et al. significantly increased this speed. "Microstereolithography using a liquid crystal display as a dynamic mask generator," Microsystem Technologies, pp. 42-47, 1997; Beluze et al., "Microstereolithography: A new process for constructing complex 3D objects, Symposium on Design, Test, and Microfabrication of MEM / MOEM," Proceedings of the SPIE Conference, v3680, n2, pp. 808-817, 1999. The core of this technology is a high-resolution spatial light modulator, which can be a liquid crystal display (LCD) panel or a digital light processing (DLP) panel, both of which are available from the microdisplay industry.

[0005] During PμSL printing, resin layers are defined between the resin tank (or container) and the sample stage. The "sample" can refer to the 3-D model, and since it is being printed layer by layer, the "sample stage" can refer to the most recently printed layer of the sample. There are at least three ways to define resin layers in PμSL: the first method uses a free surface, where the layer thickness is defined by the distance between the free surface of the resin and the sample stage. However, using this method, defining a 10μm thick layer of resin with a viscosity of 50cP on a 1cm x 1cm area can take more than half an hour. One reason for the slow printing speed is the slow viscous movement of the resin. The second and third methods of defining resin layers in PμSL use a transparent film or a hard window, respectively.

[0006] The material of the membrane or window (hereinafter referred to as the membrane) can be impermeable to air, such as polytetrafluoroethylene perfluoroalkoxy (PFA) or polytetrafluoroethylene fluorinated ethylene propylene (FEP), or the material can be permeable to air (especially oxygen), such as polydimethylsiloxane (PDMS) or polytetrafluoroethylene amorphous polymer (AF). Permeability is required to reduce adhesion between the membrane and the printed part. This is because oxygen permeation through the membrane may produce a photopolymerization inhibition layer or "dead zone", which may cause a residual layer of liquid between the membrane and the printed part. As the permeability of the membrane increases, the adhesion between the membrane and the printed part decreases.

[0007] However, the thickness of the inhibition layer is typically 10-50 μm, which can result in significant dimensional errors in precision 3D printing, where tolerance requirements may be similar to or even smaller than the thickness of the inhibition layer. Therefore, in many precision 3D printing applications, a zero-thickness or ultra-thin oxygen barrier layer is preferred. This inevitably leads to excessive adhesion between the film and the printed part. Summary of the Invention

[0008] Based on this, it is necessary to provide a 3D printing method that can improve the printing success rate.

[0009] At the same time, a 3D printing system is provided which can improve the printing success rate.

[0010] A 3D printing method, comprising:

[0011] Slicing: Generate a 3D digital model of the sample to be printed. The 3D digital model is a combination of different printing materials. The 3D digital model is discretized or sliced into an image sequence. Each image in the image sequence represents a layer of the 3D digital model. The printing direction is controlled according to the slicing direction of the model.

[0012] Projection: The image is sent to the light engine, which modulates the light source and projects the modulated light source onto the interface between the light-transmitting film and the resin through the projection lens. The light source is controlled to illuminate the projected image. The light engine and projection lens control the pixel magnification and focus the light onto the printing surface.

[0013] Exposure printing: Exposure produces a solidified layer. The XY stage controls the relative planar movement between the printing platform and the projected image to form a solidified layer of light-curing resin between the lower surface of the light-transmitting film and the upper surface of the printing platform or the upper surface of the sample fixed on the printing platform.

[0014] Separation: After a layer of printing is completed, the transparent film is peeled off from the sample by the rotating film release mechanism. The rotating film release mechanism drives the transparent film to rotate, causing one end of the transparent film to rotate around the axis, and the other end of the transparent film to move up and down relative to each other. The platform lifting stage drives the printing platform to descend until the transparent film is completely separated from the sample.

[0015] Reset: Drive the rotary film release mechanism to rotate the light-transmitting film in the opposite direction of the rotation direction of the separation step. One end of the light-transmitting film rotates in the opposite direction of the separation step, and the other end moves in the opposite direction of the separation step, driving the light-transmitting film to reset;

[0016] Continue exposure and printing: Control the platform lifting stage to drive the printing platform to move upward, then move the printing platform to the printing position of the next layer, adjust the distance between the printing platform and the transparent film, so that the distance between the lower surface of the transparent film and the upper surface of the sample fixed on the printing platform is the thickness of the next layer to be printed, and fill the gap between the sample and the transparent film with the resin required for printing the next layer, and then perform exposure and printing to print the next layer;

[0017] After the layer is printed, the separation step, reset step, and exposure printing are continued until printing is completed and the model is replicated in the resin tank.

[0018] In a preferred embodiment, the rotating film release mechanism includes a film clamp for clamping the transparent film, a driving mechanism, a driving transmission mechanism driven by the driving mechanism and connected to the film clamp, and a film clamp guiding mechanism arranged corresponding to the driving transmission mechanism to guide the movement of the film clamp. In the separation step, the speed at which the rotating film release mechanism rotates the transparent film is coordinated with the speed at which the platform lifting stage drives the printing platform to descend. The descending speed of the printing platform in the separation step is set according to the material of the transparent film, the surface area of the transparent film, the surface area of each layer of the sample, the size of the resin tank, the position of the driving transmission mechanism and the film clamp guiding mechanism, and the type of resin. Before the continued exposure printing step or before printing the next layer in the continued exposure printing step, the transparent film is flattened by setting a delay or a roller coating device.

[0019] In a preferred embodiment, in the separation step, the driving transmission mechanism drives the membrane clamp and one end of the transparent film fixed thereon to be pulled downward into the resin, and the other end of the membrane clamp and the transparent film fixed thereon rotates around the pivot of the pivot device, rotating 2-5 degrees, and rotating a part of the transparent film into the resin.

[0020] In a preferred embodiment, in the separation step, the rotating film release mechanism drives a portion of the transparent film to rotate into the resin; the driving mechanism is controlled to drive the film clamp to make one end of the transparent film descend at a speed of 1-3 mm / s, and the other end of the film clamp and the transparent film thereon rotate around the axis, while the platform lifting stage is controlled to drive the printing platform to descend at a speed of 1-3 mm / s.

[0021] In a preferred embodiment, before the exposure and printing step, the step also includes: controlling the resin tank vertical stage to drive the resin tank to move to a set position, and the movement position of the resin tank is set to match the resin depth in the resin tank, and driving the film clamp set in the resin tank to drive the transparent film to move to the set position, placing the wet surface of the transparent film, i.e., the lower surface, on the optical focal plane, and controlling the platform lifting stage to drive the printing platform to move to a set height.

[0022] In a preferred embodiment, in the reset step, the driving mechanism and the platform lifting platform are activated and started again, the driving mechanism is started to rotate part of the light-transmitting film upward, and the platform lifting platform is activated to drive the printing platform to move upward for reset; the film clamp guiding mechanism is a pivot device arranged at one end of the film clamp and pivotally connected to the film clamp, the pivot device is connected to the film clamp through a pivot and causes one end of the film clamp to rotate around the pivot, and the driving transmission mechanism includes: a driving part connected to the driving mechanism, a driving connection part connected to the driving part, and a film clamp connection part connected to the driving connection part and connected to the film clamp, the driving part, the driving connection part or either or both of them are provided with an air avoidance groove or an avoidance position at the lower part, the driving connection part is formed by bending and extending one end of the driving part, or its main body is inclined to the driving part, and is inclined at an obtuse angle to the driving part to form a connecting inclined surface.

[0023] A 3D printing system includes: an image system that establishes a 3D digital model and cuts the 3D digital model into an image sequence, a control system, a light engine that receives a series of images and modulates the light source to control the projection onto the surface to be printed, a projection lens that is arranged accordingly with the light engine and is controlled to perform projection, a printing platform arranged accordingly with the projection lens, a resin tank that accommodates the printing platform and contains resin, and a light-transmitting film arranged accordingly with the printing platform. It is characterized in that it also includes: a rotating film release mechanism arranged accordingly with the light-transmitting film, the rotating film release mechanism including: a film clamp that fixes the light-transmitting film, a driving mechanism that drives the movement of the film clamp, a driving transmission mechanism driven by the driving mechanism and connected to the film clamp, and a film clamp guiding mechanism arranged accordingly with the driving transmission mechanism to guide the movement of the film clamp. The light engine cooperates with the projection lens to control the magnification size of pixels and focus light onto the printing surface.

[0024] In a preferred embodiment, the membrane clamp guiding mechanism is a pivot device arranged at one end of the membrane clamp and pivotally connected to the membrane clamp, the pivot device is connected to the membrane clamp through a pivot and enables one end of the membrane clamp to rotate around the pivot, the driving transmission mechanism includes: a driving part connected to the driving mechanism, a driving connection part connected to the driving part, and a membrane clamp connection part connected to the driving connection part and connected to the membrane clamp, and the lower part of either or both of the driving part and the driving connection part is provided with an air avoidance groove or an air avoidance position, the driving connection part is formed by bending and extending one end of the driving part, or its main body is inclined to the driving part, and is inclined at an obtuse angle to the driving part to form a connecting inclined surface.

[0025] In a preferred embodiment, the driving connection part includes: a connecting support part connected to the driving part, and a main body connected to the connecting support part and connected to the membrane clamp connecting part, the main body of the driving connection part is inclined at a variable angle relative to the connecting support part and can be positioned and maintained at any angle, the pivot device and the driving transmission mechanism are arranged at opposite ends of the membrane clamp, the pivot device and the driving transmission mechanism are arranged on the side or end face or end surface of the membrane clamp, and the driving mechanism drives the driving part to move up and down.

[0026] In a preferred embodiment, the membrane clamp is axially connected to the driving transmission mechanism through a rotating shaft and is driven to rotate by the driving transmission mechanism. The driving transmission mechanism is a rotating bracket or a crank slider mechanism driven by the driving mechanism. The driving mechanism is rotationally driven or linearly driven. The membrane clamp guiding mechanism is arranged at the other end of the membrane clamp relative to the driving transmission mechanism. The membrane clamp guiding mechanism is a slider groove mechanism that guides and limits the movement trajectory of the other end of the membrane clamp. The light-transmitting film includes: a membrane main body, and an upwardly extending edge surrounding the top surface of the membrane main body. A vertical barrier surrounding the light-transmitting film is provided on the membrane clamp.

[0027] The aforementioned 3D printing method and system utilize a rotary film release mechanism to peel and separate the transparent film from the sample. This mechanism drives the transparent film in rotation, causing one end of the film to pivot and the other end to move up and down relative to the sample. A platform lift stage then drives the printing platform downward until the transparent film is completely separated from the sample. In this peeling method, the transparent film separates from the most recently cured layer gradually along the leading edge in the peeling direction. Because the peeling method reduces the contact area between the film layers to only the leading edge in the peeling direction, the required force and generated stress can be significantly reduced compared to conventional pulling methods. The rotary film release mechanism separates the transparent film from the printed component through a "peeling" action, overcoming the excessive adhesion of the film to the component that occurs with normal pulling, thereby improving the success rate of 3D printing. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 A schematic diagram of a partial structure of a 3D printing system according to an embodiment of the present invention;

[0029] Figure 2 This is a partial structural diagram of a film transfer release mechanism disposed on a resin tank according to an embodiment of the present invention;

[0030] Figure 3 A schematic diagram of separation performed by a transfer and release mechanism according to an embodiment of the present invention;

[0031] Figure 4 FIG. 1 is a schematic diagram of a partial printing process of a 3D printing system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0032] like Figures 3 and 4 As shown, a 3D printing method according to an embodiment of the present invention includes:

[0033] Slicing: Generate a 3D digital model of the sample to be printed. The 3D digital model is a combination of different printing materials. The 3D digital model is discretized or sliced into an image sequence. Each image in the image sequence represents a layer of the 3D digital model. The printing direction is controlled according to the slicing direction of the model.

[0034] Projection: The image is sent to the light engine 70, which modulates the light source and projects the modulated light source onto the interface between the light-transmitting film 32 and the resin through the projection lens 72. The light source is controlled to illuminate the projected image. The light engine 70 and the projection lens 72 control the pixel magnification and focus the light onto the printing surface.

[0035] Exposure printing: Exposure produces a solidified layer. The XY stage 42 controls the relative planar movement between the printing platform 50 and the projected image to form a solidified layer of the photocurable resin between the lower surface of the light-transmitting film 61 and the upper surface of the printing platform 50 or the upper surface of the sample 52 fixed on the printing platform 50.

[0036] Separation: After one layer of printing is completed, the transparent film 61 is peeled off from the sample 52 by the rotary film release mechanism. The rotary film release mechanism 60 drives the transparent film 61 to rotate, causing one end of the transparent film 61 to rotate around the axis, causing the other end of the transparent film 61 to move up and down relative to each other. The platform lifting stage 46 drives the printing platform 50 to move downward until the transparent film 61 is completely separated from the sample 52.

[0037] Reset: Drive the rotating film release mechanism 60 to rotate the light-transmitting film 61 in the opposite direction of the rotation direction of the separation step. One end of the light-transmitting film 61 rotates in the opposite direction of the separation step, and the other end moves in the opposite direction of the separation step, driving the light-transmitting film 61 to reset.

[0038] Continue exposure and printing: Control the platform lifting stage 46 to drive the printing platform 50 to move upward, then move the printing platform 50 to the printing position of the next layer, adjust the distance between the printing platform 50 and the light-transmitting film 61, so that the distance between the lower surface of the light-transmitting film 61 and the upper surface of the sample 52 fixed on the printing platform 50 is the thickness of the next layer to be printed, and fill the gap between the sample 52 and the light-transmitting film 61 with the resin 32 required for printing the next layer, and then perform exposure and printing to print the next layer;

[0039] After the layer is printed, the separation step, reset step, and exposure printing are continued until printing is completed and the model is replicated in the resin tank.

[0040] like Figures 1 to 3 As shown, further, the rotating film release mechanism 60 of this embodiment includes: a film clamp 62 for clamping the transparent film 61, a driving mechanism 64, a driving transmission mechanism 66 driven by the driving mechanism 64 and connected to the film clamp 62, and a film clamp guiding mechanism 68 arranged corresponding to the driving transmission mechanism 66 to guide the movement of the film clamp 62.

[0041] Furthermore, in the separation step of this embodiment, the speed at which the rotating film releasing mechanism 60 rotates the transparent film 61 is coordinated with the speed at which the platform lifting stage 46 drives the printing platform 50 to descend.

[0042] Furthermore, in the separation step of this embodiment, the descending speed of the printing platform 50 is set according to any one or more factors including the material of the transparent film 61, the surface area of the transparent film 61, the surface area of each layer of the sample 52, the size of the resin tank 30, the position of the driving transmission mechanism 64 and the film clamp guide mechanism 68, and the type of resin 32.

[0043] Furthermore, in this embodiment, before or during the continued exposure printing step, before printing the next layer, a delay or a roller coating device is provided to level the light-transmitting film 61 .

[0044] The gap between the light-transmitting film 61 and the printing platform 50 or the last most recently cured resin layer defines the thickness of the next layer to be cured, i.e. the printed layer. Ultraviolet light is projected onto the resin in the gap to cure the layer of resin. Curing is the process of solidifying liquid resin. In order to print the subsequent layer k+1 on the most recently cured layer k, it is critical that the adhesion between the light-transmitting film and the most recently cured layer k, i.e. the "film adhesion", is less than the adhesion between the most recently cured layer k, i.e. the bonding between the most recently cured layer k and the previously cured layer k-1. In order to prevent delamination of the cured layers, the adhesion of the light-transmitting film must be less than the adhesion between any cured layer k and k-1, and it must also be less than the adhesion between the first cured layer, i.e. k=1, and the printing platform.

[0045] When delamination occurs, it results in print failure. Print failures can be avoided or reduced by reducing the adhesion of the transparent film, that is, by reducing the force required to separate the transparent film from the newly cured resin layer. The present invention reduces the adhesion of the transparent film by separating the transparent film from the newly cured resin layer through a "peeling" motion of the rotary film release mechanism 60.

[0046] The 3D printing system and method of the present invention utilizes a rotary film release mechanism 60 to separate the transparent film from the most recently solidified layer using a pulling motion. The force required to separate the film from the printed layer using this pulling motion can be described using the Stefon equation, which describes the viscous adhesion between two parallel circular plates sandwiching a layer of viscous fluid, similar to the situation when separating the transparent film from the most recently solidified layer. The Stefon equation can be written as:

[0047]

[0048] where η is the dynamic viscosity of the viscous fluid, r is the radius of the plates, and h is the distance between the plates.

[0049] The adhesion stress σ of an object, which tends to deform the object, is per unit area r 2 The force F is as follows:

[0050]

[0051] The above equations show that the radius r (or area) of the plate significantly affects the adhesion force and adhesion stress.

[0052] Because conventional stretching methods effectively separate the transparent film from the most recently solidified layer along the entire contact area between the film layers, the required force and resulting stress can be excessive. The 3D printing system and method of the present invention utilizes a peeling method using a rotary film release mechanism 60, whereby the separation of the transparent film from the most recently solidified layer occurs gradually along the leading edge in the peeling direction. Because the peeling method reduces the contact area between the film layers to only the leading edge in the peeling direction, the required force and resulting stress can be significantly reduced compared to pulling methods.

[0053] Further, preferably, in the separation step of this embodiment, the rotary film releasing mechanism 60 drives a portion of the light-transmitting film 61 to rotate and enter the resin 32 .

[0054] The membrane clamp guiding mechanism 68 of one embodiment of the present invention is a pivot device 682 that is arranged at one end of the membrane clamp 62 and is pivotally connected to the membrane clamp 62. The pivot device 682 of this embodiment is connected to the membrane clamp 62 through a pivot and allows one end of the membrane clamp 62 to rotate around the pivot. The drive transmission mechanism 66 of this embodiment includes: a driving part 662 connected to the driving mechanism 64, a driving connection part 664 connected to the driving part 662, and a membrane clamp connection part 666 connected to the driving connection part 664 and connected to the membrane clamp 62. Preferably, the lower part of either or both of the driving part 662 and the driving connection part 664 of this embodiment is provided with an air avoidance groove 6622 or an air avoidance position. The driving connection part 664 of this embodiment is formed by bending and extending one end of the driving part 662, or its main body is inclined to the driving part 662, and is inclined at an obtuse angle to the driving part 662 to form a connecting inclined surface.

[0055] If the lifting distance of the membrane clamp 62 in this embodiment is short or not long, the driving mechanism 64 is controlled to drive the driving transmission mechanism 66 to move up and down, and the driving part 662 of the driving transmission mechanism 66 pulls one end of the membrane clamp 62 to move up and down or generate lifting movement, and the other end of the membrane clamp 62 is connected to the membrane clamp 62 through the pivot of the pivot device 682 and causes one end of the membrane clamp 62 to rotate around the pivot.

[0056] Further, preferably, when performing the separation step, the control driving mechanism 64 drives the driving transmission mechanism 66 to move downward, the driving part 662 of the driving transmission mechanism 66 pulls one end of the membrane clamp 62 to move downward, and the other end of the membrane clamp 62 rotates counterclockwise around the pivot of the pivot device 682.

[0057] When performing the separation step, if the drive transmission mechanism 66 is relatively set on the left and the pivot device 682 is relatively set on the right, the drive part 662 of the drive transmission mechanism 66 pulls one end of the membrane clamp 62 to move downward, and the other end of the membrane clamp 62 rotates counterclockwise around the pivot of the pivot device 682.

[0058] When performing the separation step, if the drive transmission mechanism 66 is relatively set on the right and the pivot device 682 is relatively set on the left, the drive part 662 of the drive transmission mechanism 66 pulls one end of the membrane clamp 62 to move downward, and the other end of the membrane clamp 62 rotates clockwise around the pivot of the pivot device 682.

[0059] When performing the separation step, if the drive transmission mechanism 66 is relatively set at the front end and the pivot device 682 is relatively set at the rear end, the drive part 662 of the drive transmission mechanism 66 pulls one end of the membrane clamp 62 to move downward, and the other end of the membrane clamp 62 rotates clockwise around the pivot of the pivot device 682.

[0060] When performing the separation step, if the drive transmission mechanism 66 is relatively set at the rear end and the pivot device 682 is relatively set at the front end, the drive part 662 of the drive transmission mechanism 66 pulls one end of the membrane clamp 62 to move downward, and the other end of the membrane clamp 62 rotates counterclockwise around the pivot of the pivot device 682.

[0061] Further, preferably, when performing the reset step, the driving mechanism 64 is controlled to drive the driving transmission mechanism 66 to move upward, the driving part 662 of the driving transmission mechanism 66 pulls one end of the membrane clamp 62 to move upward, and the other end of the membrane clamp 62 rotates clockwise around the pivot of the pivot device 682, driving the reset of the transparent film, and positioning is performed after reset.

[0062] When performing the resetting step, if the driving transmission mechanism 66 is relatively set on the left and the pivot device 682 is relatively set on the right, the driving part 662 of the driving transmission mechanism 66 pulls one end of the film clamp 62 to move upward, and the other end of the film clamp 62 rotates clockwise around the pivot of the pivot device 682, driving the resetting of the transparent film, and positioning is performed after resetting.

[0063] When performing the reset step, if the drive transmission mechanism 66 is relatively set on the right and the pivot device 682 is relatively set on the left, the drive part 662 of the drive transmission mechanism 66 pulls one end of the film clamp 62 to move upward, and the other end of the film clamp 62 rotates counterclockwise around the pivot of the pivot device 682, driving the reset of the transparent film, and positioning is performed after reset.

[0064] When performing the separation step, if the driving transmission mechanism 66 is relatively set at the front end and the pivot device 682 is relatively set at the rear end, the driving part 662 of the driving transmission mechanism 66 pulls one end of the membrane clamp 62 to move upward, and the other end of the membrane clamp 62 rotates counterclockwise around the pivot of the pivot device 682, driving the reset of the transparent film, and positioning is performed after reset.

[0065] When performing the separation step, if the driving transmission mechanism 66 is relatively set at the rear end and the pivot device 682 is relatively set at the front end, the driving part 662 of the driving transmission mechanism 66 pulls one end of the membrane clamp 62 to move upward, and the other end of the membrane clamp 62 rotates clockwise around the pivot of the pivot device 682, driving the reset of the transparent film, and positioning is performed after reset.

[0066] Further, preferably, the drive connection part 664 of this embodiment includes: a connection support part connected to the drive part 662, and a main body connected to the connection support part and connected to the membrane clamp connection part 666. The connecting bevel is provided on the main body of the drive connection part 664. Preferably, the main body of the drive connection part 664 of this embodiment is inclined to a variable angle relative to the connection support part and can be positioned and maintained at any angle. The main body of the drive connection part 664 can be set to a rotational relationship with the connection support part, and the two can be positioned and limited at any rotation angle. The main body of the drive connection part 664 can be rotated to any angle and position with the connection support part for positioning and limiting. The connection structure between the main body of the drive connection part 664 and the connection support part, such as a continuously rotating card point structure, can also adopt an arbitrary positioning pivot structure, can also be a telescopic card structure, can also be an elastic positioning structure, can also be other structures, etc.

[0067] The pivoting device 682 and the drive transmission mechanism 66 of this embodiment are respectively disposed at opposite ends of the membrane clamp 62. The opposite ends of the membrane clamp 62 of this embodiment are located at positions where the pivoting device 682 and the drive transmission mechanism 66 extend beyond the midpoint of the membrane clamp 62, and are disposed in two opposite directions away from the midpoint of the membrane clamp 62.

[0068] Furthermore, preferably, the pivoting device 682 and the drive transmission mechanism 66 of this embodiment can be arranged on the side, end face, or end surface of the film clamp 62. The control system controls the drive mechanism 64 to drive the drive portion 662 of the drive transmission mechanism 66 to move up and down, so that the drive mechanism 64 drives the drive portion 662 of the drive transmission mechanism 66 to pull the film clamp 62 perpendicular to the surface of the latest solidified layer.

[0069] In this embodiment, the film clamp 62 is connected to a drive transmission mechanism 66 in a first position. The drive transmission mechanism 66 is mounted on the resin tank 30. In a second position, the film clamp 62 is connected to a pivot joint of a pivot joint 682. The pivot joint 682 is mounted on the resin tank 30. Actuation of the drive mechanism 64 causes the film clamp 62, carrying the light-transmitting film 61, to rotate about the pivot joint of the pivot joint 682, either downward into the resin or upward.

[0070] The control system controls the platform lift stage 46, which drives the printing platform 50 up and down, controlling the height of the printing platform 50 that supports the printed sample. Each layer of the sample is produced by light-curing the resin layer immediately below the film. The sample is fixed to the printing platform 50 by adhesion of the first printed layer, and subsequent layers are printed on top of the previous layer. The resin tank vertical stage 44 controls the height of the resin tank 30 and the transparent film attached to it to accommodate different resin depths in the resin tank and / or position the wet surface (lower surface) of the transparent film in the optical focal plane.

[0071] Before the exposure and printing step, it also includes: controlling the resin tank vertical stage 44 to drive the resin tank 30 to move to a set position, and the movement position of the resin tank 30 is set to match the resin depth in the resin tank, and driving the film clamp 62 set in the resin tank 30 to drive the transparent film 61 to move to a set position, placing the wet surface of the transparent film, i.e., the lower surface, on the optical focal plane, and controlling the platform lifting stage 46 to drive the printing platform 50 to move to a set height.

[0072] Furthermore, the pivot assembly 682 and drive mechanism 64 of this embodiment are mounted on the resin tank 30. Preferably, the drive mechanism 64 of this embodiment is mounted on the outer sidewall of one side of the resin tank 30. The pivot assembly 682 is mounted on the front and rear sidewalls of the resin tank 30, and its pivot is connected to the other end of the film clamp 62, allowing the film clamp 62 to rotate around it. The pivot assembly 682 can be connected to the sidewall at the other end of the film clamp 62.

[0073] The transparent film 61 is fixed to the film clamp 62. One end of the film clamp 62 is connected to the drive transmission mechanism 66, and the other end is connected to the pivot device 682. The drive mechanism 64 drives the film clamp 62, causing the other end of the film clamp 62 to rotate about the pivot of the pivot device 682, thereby driving the transparent film 61 to rotate about the pivot of the pivot device 682. The drive mechanism 64 is the mechanism that drives the film clamp 62 and can be a rotary motor or linear stage.

[0074] A new resin layer has just been photocured between the lower surface of the light-transmitting film 61 and the upper surface of the sample, forming a new photocured layer of the sample. However, the new photocured layer adheres to the film. In order to form more layers of the sample, the light-transmitting film 61 must be separated from the sample. The light-transmitting film 61 is peeled off from the sample by rotating the film release mechanism 60 for separation. The control drive mechanism 64 is activated, and the drive transmission mechanism 66 drives the film clamp 62 and the left side of the light-transmitting film 61 fixed thereon to be pulled downward into the resin. The other end of the film clamp 62 and the light-transmitting film 61 fixed thereon rotate counterclockwise around the pivot of the pivot device 682, rotating at a small angle of about 2-5 degrees.

[0075] Preferably, the driving film clamp 62 drives the transparent film 61 to rotate a portion of the transparent film 61 into the resin to avoid the problem of air being introduced under the transparent film 61 and causing bubbles to appear during the subsequent layer printing process. While the driving mechanism 64 drives the rotating transparent film 61, the control platform lifting stage 46 drives the printing platform 50 to move downward. The driving mechanism 64 drives the rotating transparent film 61 to rotate and the printing platform 50 to descend, and the transparent film 61 is peeled off from the sample. Starting from the right end of the transparent film 61, all the way to the left end of the transparent film 61. Continue to rotate the film clamp 62 and the transparent film 61 and the printing platform 50 thereon and descend until the film is completely separated from the sample, that is, until the transparent film 61 is completely out of contact with the sample.

[0076] For optimal results, the speed at which the drive mechanism 64 rotates the transparent film 61 and the speed at which the platform elevating stage 46 lowers the printing platform 50 should be appropriately balanced. These speeds may depend on a number of factors, including the material of the transparent film 61, the surface area of the transparent film 61, the surface area of each sample layer, the size of the resin tank 30, the position of the drive mechanism 64, the drive transmission mechanism 66, and the pivoting device 682, and the type of resin. Preferably, in this embodiment, the drive mechanism 64 is driven to lower the left end of the transparent film 61 at a speed of 1-3 mm / s, and correspondingly, the platform elevating stage 46 lowers the printing platform 50 at a speed of 1-3 mm / s.

[0077] Each layer of the present invention's sample corresponds to a 2D image, created by discretizing or slicing the 3D computer-aided design model of the part to be printed into a series of cross-sectional images. The number of cross-sectional images per unit length, and therefore the number of layers per unit length, depends on several factors, including the desired vertical resolution of the printed part, the resolution capabilities of the selected 3D printing technology, the type of printed part, and the resin used for printing. The layer thickness in this example ranged from 5 to 20 μm.

[0078] To print a layer, a computer sends an image corresponding to that layer to a light engine. A light source, such as a UV light source, coupled to or integrated with the light engine is modulated by the light engine and then projected and focused through a projection lens onto a layer of photocurable resin adjacent to the lower surface of the light-transmitting film 61. The projected and focused modulated UV light appears as a pattern of light and dark areas based on the image sent by the computer. The bright areas cure or polymerize the photocurable resin, transforming it from a liquid to a solid. The dark areas remain liquid. At this point, a new layer has been added to the sample; however, the newly printed layer may adhere to the lower surface of the light-transmitting film 61.

[0079] The drive mechanism 64 is activated, rotating the transparent film 61 counterclockwise into the resin. Simultaneously, the platform lift stage 46 is activated, driving the printing platform 50 downward. The film clamp 62 drives the transparent film 61 to rotate simultaneously with the downward movement of the printing platform 50, and this continues until the entire film is peeled off the sample.

[0080] Furthermore, the film clamp 62 of this embodiment preferably includes a vertical barrier that surrounds the entire transparent film 61 to prevent resin from flowing in during rotation. Preferably, the transparent film 61 is rotated to minimize the angle of rotation according to the separation conditions to prevent resin from flowing in during rotation. The rotating film release mechanism 60 prevents any resin from flowing around and on top of the transparent film 61 during the peeling process.

[0081] In another embodiment of the present invention, the membrane clasp 62 is axially connected to a drive transmission mechanism via a rotating shaft and is driven for rotation by the drive transmission mechanism. The drive transmission mechanism can be a rotating bracket driven by the drive mechanism, or a crank slider mechanism, etc. The rotating bracket is driven to rotate by a rotary motor, thereby driving one end of the membrane clasp 62 to rotate about the rotating shaft. The rotary motor can be arranged on the side of the rotating bracket and axially connected to the rotating bracket. For example, a shaft sleeve connection can be used, although other axial connection methods can also be used to drive the rotating bracket to achieve rotation and flipping movements. If the drive transmission mechanism is a crank slider mechanism, the drive mechanism is a linear drive mechanism, and the driving slider moves linearly along the guide rail, thereby driving the rotating pair to rotate. The rotating pair is axially connected to one end of the membrane clasp 62, thereby driving the rotation of the membrane clasp. Preferably, the membrane clasp 62 of this embodiment is provided with a membrane clasp guide mechanism at the other end relative to the drive transmission mechanism. The preferred membrane clasp guide mechanism is a slider groove mechanism that guides and limits the motion trajectory of the other end of the membrane clasp, thereby limiting the motion trajectory of the membrane clasp 62 to ensure smooth movement of the membrane clasp 62.

[0082] During the reset step, the drive mechanism and the platform lifting platform 46 of this embodiment are activated for the second time, and the second activation of the drive mechanism causes the transparent film 61 to rotate upward by φ degrees. The second activation of the platform lifting platform 46 drives the printing platform 50 to move upward.

[0083] The light engine coupled to the light source and the projection lens projects the second image received from the computer onto the light curing resin sandwiched between the lower surface of the light transparent film 61 and the upper surface of the first curing layer to form a second curing layer.

[0084] The resin tank vertical stage 44 drives the resin tank 30 to move up and down. The resin is stored in the resin tank 30. The drive mechanism and the pivot device 682 are attached upward or downward to the resin tank 30. The resin tank vertical stage 44 drives the resin tank 30 to move up and down to accommodate different depths of resin in the resin tank 30 and / or place the wet surface (bottom surface) of the light-transmitting film 61 at the focal plane of the optical device.

[0085] Further, preferably, the light-transmitting film 61 includes: a film body, and an edge surrounding the film body and extending upward.

[0086] The 3D printing system of this embodiment includes a computer (i.e., imaging system 20) that transmits an image to a light engine. The light engine may include a digital light processing (DLP) chip or a liquid crystal display (LCD), coupled to a light-emitting diode (LED) light source in the case of projection micro-stereolithography (PμSL), or a laser beam coupled to a reflective mirror in the case of stereolithography (SLA). The light engine is coupled to a projection lens that defines the magnification of the pixel size and focuses the light onto the printing surface.

[0087] The XY stage controls the relative planar motion, such as lateral motion, between the projected image (from the light engine and projection lens) and the print platform on which the sample is printed. The resin tank holds the resin, and near the top of the resin is a transparent film 61. This film is made of perfluoroalkoxy (PFA) or fluorinated ethylene propylene (FEP) and is typically 50-100 μm thick.

[0088] The platform lifting stage 46 controls the height of the printing platform for printing samples. Each layer of the sample is produced by photocuring a layer of resin under the light-transmitting film. The sample is fixed to the printing platform by bonding the first printed layer, and subsequent layers are printed on top of the previous printed layer. The resin tank vertical stage 44 controls the height of the resin tank and the light-transmitting film attached thereto to accommodate different depths of resin in the resin tank and / or place the wet surface (bottom surface) of the film at the focal plane of the optical device. The light engine coupled to the light source and the projection lens projects the second image received from the computer onto a second layer of light-curing resin sandwiched between the lower surface of the light-transmitting film and the upper surface of the first cured layer to produce light-curing resin to form a second cured layer.

[0089] The drive mechanism is activated a second time, driving the transparent film 61 to rotate clockwise, thereby returning it to the initial printing position and positioning it. The platform lift stage 46 is activated a second time, causing the printing platform to move upward onto the transparent film and return it to a suitable height for printing the next layer. The second activation of the drive mechanism and the second activation of the platform lift stage 46 can occur in the same order as described above, or simultaneously. In some cases, the transparent film 61 may be deformed due to tension during rotation. Before printing the next layer, a delay is set and / or a technique such as roller coating is used to flatten the transparent film 61.

[0090] A first image received by the light engine from a computer is projected to form a cured layer of photocurable resin sandwiched between the lower surface of the transparent film and the upper surface of a printed sample secured to the platform. A portion of the transparent film is then rotated downward by Φ degrees while the printing platform is moved downward until the film is no longer in contact with the first cured layer. The transparent film is partially rotated upward by Φ degrees, and the printing platform is moved upward. A second image received by the light engine from a computer is projected to form a second cured layer of photocurable resin sandwiched between the lower surface of the transparent film and the upper surface of the first cured layer. The transparent film 61 is positioned vertically relative to the focal plane of the light engine 70 by moving the resin tank 30, which stores the resin, upward or downward.

[0091] like Figures 1 to 4 As shown, a 3D printing system 100 according to an embodiment of the present invention includes: an image system 20 for establishing a 3D digital model and cutting the 3D digital model into an image sequence, a control system, a light engine 70 for receiving a series of images and modulating a light source for controlled projection onto a surface to be printed, a projection lens 72 arranged in correspondence with the light engine 70 and controlled for projection, a printing platform 50 arranged in correspondence with the projection lens 72, a resin tank 30 for accommodating the printing platform 50 and containing resin, a light-transmitting film 61 arranged in correspondence with the printing platform 50, and a rotating film release mechanism 60 arranged in correspondence with the light-transmitting film 61.

[0092] The rotary film release mechanism 60 includes a film clamp 62 that secures the light-transmitting film 61, a drive mechanism 64 that drives the film clamp 62, a drive transmission mechanism 66 driven by the drive mechanism 64 and connected to the film clamp 62, and a film clamp guide mechanism 68, coupled to the drive transmission mechanism 66, that guides the movement of the film clamp 62. The light engine 70 works in conjunction with the projection lens 72 to control the pixel magnification and focus light onto the printing surface.

[0093] In one embodiment of the present invention, the membrane clamp guiding mechanism 68 is a pivoting device 682 provided at one end of the membrane clamp 62 and pivotally connected to the membrane clamp 62. The pivoting device 682 is connected to the membrane clamp 62 via a pivot and allows one end of the membrane clamp 62 to rotate around the pivot.

[0094] The membrane clamp guiding mechanism 68 of one embodiment of the present invention is a pivot device 682 that is arranged at one end of the membrane clamp 62 and is pivotally connected to the membrane clamp 62. The pivot device 682 of this embodiment is connected to the membrane clamp 62 through a pivot and allows one end of the membrane clamp 62 to rotate around the pivot. The drive transmission mechanism 66 of this embodiment includes: a driving part 662 connected to the driving mechanism 64, a driving connection part 664 connected to the driving part 662, and a membrane clamp connection part 666 connected to the driving connection part 664 and connected to the membrane clamp 62. Preferably, the lower part of either or both of the driving part 662 and the driving connection part 664 of this embodiment is provided with an air avoidance groove 6622 or an air avoidance position. The driving connection part 664 of this embodiment is formed by bending and extending one end of the driving part 662, or its main body is inclined to the driving part 662, and is inclined at an obtuse angle to the driving part 662 to form a connecting inclined surface.

[0095] Furthermore, preferably, the drive connection portion 664 of this embodiment includes: a connection support portion connected to the drive portion 662, and a main body connected to the connection support portion and connected to the membrane clamp connection portion 666. The connection bevel is provided on the main body of the drive connection portion 664. Preferably, the main body of the drive connection portion 664 of this embodiment is tilted at a variable angle relative to the connection support portion and can be positioned and maintained at any angle. The main body of the drive connection portion 664 can be set to a rotational relationship with the connection support portion, and the two can be positioned and limited at any rotation angle. The main body of the drive connection portion 664 can be rotated to any angle and position relative to the connection support portion for positioning and limitation. The connection structure between the main body of the drive connection portion 664 and the connection support portion can be a continuously rotating card point structure, an arbitrary positioning pivot structure, a telescopic card structure, an elastic positioning structure, or other structures. The main body of the drive connection portion 664 is tilted at a variable angle relative to the connection support portion and can be positioned and maintained at any angle.

[0096] The pivoting device 682 and the drive transmission mechanism 66 of this embodiment are respectively disposed at opposite ends of the membrane clamp 62. The opposite ends of the membrane clamp 62 of this embodiment are located at positions where the pivoting device 682 and the drive transmission mechanism 66 extend beyond the midpoint of the membrane clamp 62, and are disposed in two opposite directions away from the midpoint of the membrane clamp 62.

[0097] Furthermore, preferably, the pivoting device 682 and the drive transmission mechanism 66 of this embodiment can be arranged on the side, end face, or end surface of the film clamp 62. The control system controls the drive mechanism 64 to drive the drive portion 662 of the drive transmission mechanism 66 to move up and down, so that the drive mechanism 64 drives the drive portion 662 of the drive transmission mechanism 66 to pull the film clamp 62 perpendicular to the surface of the latest solidified layer.

[0098] In this embodiment, the film clamp 62 is connected to a drive transmission mechanism 66 in a first position. The drive transmission mechanism 66 is mounted on the resin tank 30. In a second position, the film clamp 62 is connected to a pivot joint of a pivot joint 682. The pivot joint 682 is mounted on the resin tank 30. Actuation of the drive mechanism 64 causes the film clamp 62, carrying the light-transmitting film 61, to rotate about the pivot joint of the pivot joint 682, either downward into the resin or upward.

[0099] In another embodiment of the present invention, the membrane clasp 62 is axially connected to a drive transmission mechanism via a rotating shaft and is driven for rotation by the drive transmission mechanism. The drive transmission mechanism can be a rotating bracket driven by the drive mechanism, or a crank slider mechanism, etc. The rotating bracket is driven to rotate by a rotary motor, thereby driving one end of the membrane clasp 62 to rotate about the rotating shaft. The rotary motor can be arranged on the side of the rotating bracket and axially connected to the rotating bracket. For example, a shaft sleeve connection can be used, and of course other axial connection methods can also be used to drive the rotating bracket to achieve rotation and flipping movements. If the drive transmission mechanism is a crank slider mechanism, the drive mechanism is a linear drive mechanism, and the driving slider moves linearly along the guide rail, thereby driving the rotating pair to rotate. The rotating pair is axially connected to one end of the membrane clasp 62, thereby driving the other end of the membrane clasp to rotate. Preferably, the membrane clasp 62 of this embodiment is provided with a membrane clasp guide mechanism at the other end relative to the drive transmission mechanism. The preferred membrane clasp guide mechanism is a slider groove mechanism that guides and limits the motion trajectory of the other end of the membrane clasp, thereby limiting the motion trajectory of the membrane clasp to ensure smooth movement of the membrane clasp.

[0100] Further, preferably, the light-transmitting film of this embodiment includes: a film body, and an edge extending upwards and surrounding a top surface of the film body.

[0101] The light engine is coupled to a light source and a projection lens, which projects a first image received from a computer onto a first layer of photocurable resin, which is sandwiched between the lower surface of the transparent film and the printing platform. The film clamp is coupled to a drive mechanism and a pivot assembly 682, securing the surface of the print sample to the printing platform. The printing platform is connected to a platform lift stage 46, which drives the printing platform to a set position to produce the first cured layer. The drive mechanism 64 and the platform lift stage 46 perform a first operation simultaneously. The drive mechanism 64 is actuated for the first time to rotate a portion of the transparent film downward about the pivot axis of the pivot assembly 682 by Φ degrees. The platform lift stage 46 is actuated for the first time to move the printing platform downward until the film is completely clear of the first photocurable layer. The drive mechanism 64 and the platform lift stage 46 perform a second operation. The drive mechanism 64 is actuated for the second time to rotate a portion of the transparent film upward by Φ degrees. The platform lift stage 46 is actuated for the second time to move the printing platform upward.

[0102] The light engine coupled to the light source and the projection lens projects the second image received from the computer onto a second layer of photocurable resin sandwiched between the lower surface of the light-transmitting film and the upper surface of the first cured layer to produce a second cured layer.

[0103] Furthermore, the 3D printing system of this embodiment further includes a resin tank vertical stage 44. The resin tank vertical stage 44 moves the resin tank storing the resin, and the driving mechanism and the pivot device 682 mounted on the resin tank move upward or downward relative to the focal plane of the projection lens.

[0104] Based on the above-mentioned ideal embodiments of this application, and in accordance with the above description, relevant personnel can make various changes and modifications without departing from the scope of the technical concept of this application. The technical scope of this application is not limited to the contents of the specification, but must be determined according to the scope of the claims.

[0105] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0106] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the steps in the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0107] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0108] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

Claims

1. A 3D printing method, characterized in that: include: Slicing: Generate a 3D digital model of the sample to be printed. The 3D digital model is a combination of different printing materials. The 3D digital model is discretized or sliced into an image sequence. Each image in the image sequence represents a layer of the 3D digital model. The printing direction is controlled according to the slicing direction of the model. Projection: The image is sent to the light engine, which modulates the light source and projects the modulated light source onto the interface between the light-transmitting film and the resin through the projection lens. The light source is controlled to illuminate the projected image. The light engine and projection lens control the pixel magnification and focus the light onto the printing surface. Exposure printing: Exposure produces a solidified layer. The XY stage controls the relative planar movement between the printing platform and the projected image to form a solidified layer of light-curing resin between the lower surface of the light-transmitting film and the upper surface of the printing platform or the upper surface of the sample fixed on the printing platform. Separation: After a layer of printing is completed, the transparent film is peeled off from the sample by the rotating film release mechanism. The rotating film release mechanism drives the transparent film to rotate, causing one end of the transparent film to rotate around the axis, and the other end of the transparent film to move up and down relative to each other. The platform lifting stage drives the printing platform to descend until the transparent film is completely separated from the sample. Reset: Drive the rotary film release mechanism to rotate the light-transmitting film in the opposite direction of the rotation direction of the separation step. One end of the light-transmitting film rotates in the opposite direction of the separation step, and the other end moves in the opposite direction of the separation step, driving the light-transmitting film to reset; Continue exposure and printing: Control the platform lifting stage to drive the printing platform upward, then move the printing platform to the printing position of the next layer, adjust the distance between the printing platform and the transparent film, so that the distance between the lower surface of the transparent film and the upper surface of the sample fixed on the printing platform is the thickness of the next layer to be printed, and fill the gap between the sample and the transparent film with the resin required for printing the next layer, and then expose and print to print the next layer; After the layer is printed, the separation step, reset step, and exposure printing are continued until the printing is completed and the model is replicated in the resin tank; In the separation step, the driving transmission mechanism drives the film clamp and one end of the transparent film fixed thereon to be pulled downward into the resin, and the other end of the film clamp and the transparent film fixed thereon rotates around the pivot of the pivot device by 2-5 degrees, rotating a part of the transparent film into the resin.

2. The 3D printing method according to claim 1, wherein: The rotating film releasing mechanism includes a film clamp for clamping the light-transmitting film, a driving mechanism, a driving transmission mechanism driven by the driving mechanism and connected to the film clamp, and a film clamp guiding mechanism arranged corresponding to the driving transmission mechanism for guiding the movement of the film clamp. In the separation step, the speed at which the rotating film releasing mechanism rotates the light-transmitting film is coordinated with the speed at which the platform lifting stage drives the printing platform to descend. The descending speed of the printing platform in the separation step is set according to the material of the light-transmitting film, the surface area of the light-transmitting film, the surface area of each layer of the sample, the size of the resin tank, the position of the driving transmission mechanism and the film clamp guiding mechanism, and the type of resin. Before the continued exposure printing step or before printing the next layer in the continued exposure printing step, the light-transmitting film is flattened by setting a delay or a roller coating device.

3. The 3D printing method according to any one of claims 1 to 2, characterized in that: During the separation step, the rotating film release mechanism drives a portion of the transparent film to rotate into the resin; the driving mechanism is controlled to drive the film clamp to make one end of the transparent film descend at a speed of 1-3 mm / s, and the film clamp and the other end of the transparent film on it rotate around the axis, while the platform lifting stage is controlled to drive the printing platform to descend at a speed of 1-3 mm / s.

4. The 3D printing method according to any one of claims 1 to 2, characterized in that: Before the exposure and printing step, the step also includes: controlling the resin tank vertical stage to drive the resin tank to move to a set position, and the movement position of the resin tank is matched with the resin depth in the resin tank, and driving the film clamp set in the resin tank to drive the transparent film to move to a set position, placing the wet surface, i.e., the lower surface, of the transparent film on the optical focal plane, and controlling the platform lifting stage to drive the printing platform to move to a set height.

5. The 3D printing method according to claim 2, wherein: During the resetting step, the driving mechanism and the platform lifting platform are activated and started again, the driving mechanism is started to rotate part of the light-transmitting film upward, and the platform lifting platform is activated to drive the printing platform to move upward for resetting; the film clamp guiding mechanism is a pivot device arranged at one end of the film clamp and pivotally connected to the film clamp, the pivot device is connected to the film clamp through a pivot and causes one end of the film clamp to rotate around the pivot, and the driving transmission mechanism includes: a driving part connected to the driving mechanism, a driving connection part connected to the driving part, and a film clamp connection part connected to the driving connection part and connected to the film clamp, the driving part and the driving connection part or both of which are provided with an air avoidance groove or an avoidance position at the lower part, the driving connection part is formed by bending and extending one end of the driving part, or its main body is inclined to the driving part, and is inclined at an obtuse angle to the driving part to form a connecting inclined surface.

6. A 3D printing system using the 3D printing method according to claim 1, comprising: An image system for establishing a 3D digital model and cutting the 3D digital model into an image sequence, a control system, a light engine that receives a series of images and modulates the light source for controlled projection onto the surface to be printed, a projection lens that is arranged accordingly with the light engine and is controlled to perform projection, a printing platform that is arranged accordingly with the projection lens, a resin tank that accommodates the printing platform and contains resin, and a light-transmitting film that is arranged accordingly with the printing platform. It is characterized in that it also includes: a rotating film releasing mechanism that is arranged accordingly with the light-transmitting film, the rotating film releasing mechanism includes: a film clamp that fixes the light-transmitting film, a driving mechanism that drives the movement of the film clamp, a driving transmission mechanism driven by the driving mechanism and connected to the film clamp, and a film clamp guiding mechanism that is arranged accordingly with the driving transmission mechanism to guide the movement of the film clamp. The light engine cooperates with the projection lens to control the magnification size of the pixels and focus the light onto the printing surface.

7. The 3D printing system according to claim 6, characterized in that: The membrane clamp guiding mechanism is a pivot device arranged at one end of the membrane clamp and pivotally connected to the membrane clamp, the pivot device is connected to the membrane clamp through a pivot and enables one end of the membrane clamp to rotate around the pivot, and the driving transmission mechanism includes: a driving part connected to the driving mechanism, a driving connection part connected to the driving part, and a membrane clamp connection part connected to the driving connection part and connected to the membrane clamp, and an air avoidance groove or air avoidance position is provided at the lower part of either or both of the driving part and the driving connection part, and the driving connection part is formed by bending and extending one end of the driving part or its main body is inclined to the driving part and inclined at an obtuse angle to the driving part to form a connecting inclined surface.

8. The 3D printing system according to claim 7, characterized in that: The driving connection part includes: a connecting support part connected to the driving part, and a main body connected to the connecting support part and connected to the membrane clamp connecting part. The main body of the driving connection part is inclined at a variable angle relative to the connecting support part and can be positioned and maintained at any angle. The pivot device and the driving transmission mechanism are arranged at opposite ends of the membrane clamp. The pivot device and the driving transmission mechanism are arranged on the side or end surface of the membrane clamp, and the driving mechanism drives the driving part to move up and down.

9. The 3D printing system according to claim 7 or 8, characterized in that: The film clamp is axially connected to the driving transmission mechanism through a rotating shaft and is driven to rotate by the driving transmission mechanism. The driving transmission mechanism is a rotating bracket or a crank slider mechanism driven by the driving mechanism. The driving mechanism is rotationally driven or linearly driven. The film clamp guide mechanism is arranged at the other end of the film clamp relative to the driving transmission mechanism. The light-transmitting film includes: a film body, and an upwardly extending edge surrounding the top surface of the film body. A vertical barrier surrounding the light-transmitting film is provided on the film clamp.

Images