Dual-lens combined projection type light-cured biological 3D printing device

Abstract

This invention discloses a dual-lens combined projection-type photopolymerization bio-3D printing device, including a frame, a printing platform and drive assembly, a material tank, an optical system, and a laser light source. The optical system includes: a projection lens I and a projection lens II with different magnifications; a lens converter for switching between projection lens I and projection lens II as the working lens, which simultaneously mounts both projection lenses I and II; and a sleeve lens fixed to the bottom of the lens converter and aligned with the working lens. This invention's dual-lens combined projection-type photopolymerization bio-3D printing device uses a collimated laser as the light source, avoiding a cumbersome lens system. The sleeve lens design combined with the projection lens provides excellent imaging results. Furthermore, the switching of the projection lens on the lens converter allows for flexible and effective control of printing accuracy and print size, enabling high-resolution, high-speed printing of bio-ink materials.

Description

Technical Field

[0001] This invention belongs to the field of 3D printing, specifically relating to a dual-lens combined projection-type photopolymerization biological 3D printing device. Background Technology

[0002] Digital Light Processing (DLP) 3D printing technology projects a slice of the desired 3D object onto the bottom of a photosensitive resin bath using a digital micromirror array (DMD). The photosensitive resin, exposed to light, undergoes localized curing. Once one layer is printed, the printing platform moves up one layer's distance and continues selectively cross-linking using a patterned light source. A new resin pattern is then firmly bonded to the surface of the previously cured resin. This process is repeated until the 3D object is printed. DLP 3D printing cures the entire surface of the photosensitive resin, and regardless of the complexity of the single-layer projection pattern, the printing time remains the same. Compared to other 3D printing methods, it is more efficient, offers higher printing accuracy, and is easier to control.

[0003] Because the resolution of the DMD chip in a projection-based photopolymerization 3D printing device is fixed, and the magnification of the projection mechanism is also fixed, and the higher the magnification, the higher the optical accuracy and the smaller the printing area, conventional photopolymerization printing devices face the technical challenge of achieving high-speed, high-resolution printing. Therefore, it is necessary to design a dual-lens combined projection-based photopolymerization bio-3D printing device to solve these technical problems.

[0004] CN 112549537 A discloses a dual-lens combination precision-enhancing 3D printing device and printing method, which includes a DLP system, two projection lenses with different magnifications, a beam splitter, a reflector, and a precision moving system. The light path emitted by the DLP system passes through the beam splitter, is partially reflected and enters the first projection lens, and is partially transmitted and reflected by the reflector and enters the second projection lens; by adjusting the beam splitter and reflector, both light paths are projected onto the overlapping printing plane. This solves the problem of the limitation on printing speed due to the fixed precision of a single printing system, and the contradiction between printing precision and printing size. However, this technical solution has the following problems: (1) The design of the top projection structure adopted in this paper requires more material to be consumed during printing; (2) The object distance of the dual-lens design used in this technical solution is changing, which requires higher processing precision and motion precision; (3) At the same time, the beam splitter design used in this technical solution has strict requirements on angle, and also needs to consider the bonding gap and beam displacement, which requires high system precision. Summary of the Invention

[0005] The purpose of this invention is to provide a dual-lens combined projection-type photopolymerization biological 3D printing device, which can achieve rapid DLP printing of two printing accuracies and sizes by switching projection lenses with different magnifications.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A dual-lens combined projection-type photopolymerization bio-3D printing device includes a frame; and a printing platform and drive assembly, a material tank, an optical system, and a laser light source device mounted on the frame and cooperating with each other. The optical system includes:

[0008] Projection lens I and projection lens II with different magnification;

[0009] An objective lens converter for switching one of the projection objective lens I and projection objective lens II as the working objective lens, which simultaneously enables the installation of both projection objective lens I and projection objective lens II;

[0010] A sleeve lens fixed to the bottom of the objective lens converter and aligned with the working objective lens;

[0011] The exit end of the working objective lens is aligned with the printing platform and the material tank, and the entrance end of the sleeve lens is aligned with the exit end of the laser source device.

[0012] In this invention, the optical system is an infinity optical system composed of a projection lens and a sleeve lens. In this infinity optical system, the projection lens does not directly image; instead, a parallel beam of light (such as an object at infinity) enters the sleeve lens and is imaged through the sleeve lens. Due to the reversibility of the optical path, the projected light rays emitted from the DMD pass through the sleeve lens and enter the projection lens as a parallel beam, projecting the projected pattern onto the printing ink tank. Because the light rays between the projection lens and the sleeve lens are parallel to each other, forming an infinity space, additional optical elements can be introduced to correct the system's aberrations without causing optical loss. Changing the spacing between the projection lens and the sleeve lens ensures that the overall magnification remains constant. Furthermore, when different projection lenses are moved to the infinity optical path, their parfocal design is maintained, eliminating the need for refocusing.

[0013] As one implementation scheme, in this invention, the printing platform and driving components include:

[0014] Lead screw and slider mechanism;

[0015] A printing platform fixed on the slider of a lead screw and slider mechanism.

[0016] Furthermore, the lead screw and slider mechanism may include a lead screw motor and a slider installed at the output end of the lead screw motor; the printing platform is generally fixed on the slider, and the lead screw motor drives the printing platform to move up and down.

[0017] Furthermore, it also includes a submicron-level XY-axis displacement stage mounted on the frame; the optical system and laser light source device are disposed on this submicron-level XY-axis displacement stage. This stage is used to move the laser light source device in the XY-axis direction, adjust the relative position of the projected pattern and the exposure surface of the material tank, and stitch together the printing area according to computer-input instructions.

[0018] As one implementation, the objective lens converter includes:

[0019] Mounting base;

[0020] A sliding objective lens mounting plate that can be mounted on a mounting base;

[0021] A motor that drives the objective lens mounting plate to move in a set direction;

[0022] The objective lens mounting plate is provided with mounting holes for mounting the projection objective lens I and the projection objective lens II. The working objective lens can be switched by moving the objective lens mounting plate driven by a motor.

[0023] Furthermore, the mounting base is provided with a mounting cavity, and the bottom of the mounting cavity is provided with an optical path through hole aligned with the working objective lens; the objective lens mounting plate is disposed in the mounting cavity, and a matching guide rail mechanism is provided between the two.

[0024] As one implementation, the laser source device includes:

[0025] Laser;

[0026] Laser bevel;

[0027] A Z-axis lifting platform fixed on the laser inclined plane for adjusting the Z-axis height of the laser;

[0028] An angle tilting platform fixed on the Z-axis lifting platform for adjusting the Z-axis mounting angle of the laser;

[0029] A laser bracket fixed on an angled platform for mounting the laser.

[0030] Furthermore, the laser can be an existing laser, such as a 405nm laser.

[0031] During installation, the bottom of the laser inclined plane can be connected to the top of the submicron-level XY-axis displacement stage via threads; alternatively, other common methods such as snap-fit ​​or magnetic connection can be used. The Z-axis lifting stage can be connected via threads at the inclined section of the laser inclined plane. The angle tilting platform is vertically mounted on the top of the Z-axis lifting stage via threads; the laser bracket is fixed to the top of the angle tilting platform; the 405nm laser is nested within the laser bracket; similarly, the connections between the above components can be achieved using any of the aforementioned existing methods.

[0032] Furthermore, the laser inclined plane is arranged in an "L" shape; the horizontal section of the "L" shape is used to fix the Z-axis lifting platform; the top of the vertical section of the "L" shape is fixed with a DMD chip and a TIR prism; the collimated laser emitted by the laser passes through the TIR prism and enters the DMD chip; the light emitted from the DMD chip is totally reflected at the interface of the TIR prism and then emitted vertically from the side of the prism, and is received by the optical system.

[0033] Furthermore, the vertical section of the laser slope has grooves extending to the bottom at both ends of the top, where the DMD chip and TIR prism can be mounted. On the side corresponding to the 405nm laser, there is also a pair of limiting protrusions, where the TIR prism can be fixed.

[0034] As an implementation scheme, the parfocal distances of the projection lenses I and II are the same, and the structure and installation of the lens mounting arm make the working distance of the projection lenses I and II the distance from the leading edge of the lens to the film in the feed tank.

[0035] As an implementation scheme, the outgoing optical axis of the TIR prism coincides with the optical axis of the sleeve lens and the working objective lens.

[0036] As an implementation scheme, the frame includes a top plate, a bottom plate, and a support rod that fixes the two together.

[0037] The printing platform, drive components, and material trough are mounted on the top plate;

[0038] The optical system, laser source device, and submicron-level XY-axis displacement stage are mounted on the base plate.

[0039] As one specific implementation, a dual-lens combined projection-type photopolymerization bio-3D printing device includes a submicron-level XY-axis displacement stage, a laser light source device, an objective lens mounting arm, a sleeve lens, an objective lens converter, and projection objective lens I and projection objective lens II. The submicron-level XY-axis displacement stage is mounted on the frame base plate via a bottom thread. The laser light source device and the objective lens mounting arm are mounted on the top of the submicron-level XY-axis displacement stage. The objective lens converter is connected to the objective lens mounting arm (e.g., via locking screws, snap-fit, bonding, magnetic attraction, etc.), and a sleeve lens is mounted on the bottom of the objective lens converter. Projection objective lens I and projection objective lens II with different magnifications are vertically mounted on the top of the objective lens converter. Vibration isolation pads are installed on the bottom of the frame base plate, and the base plate is connected to the top plate via a support rod. A printing material trough and a lead screw slider mechanism are fixed on the top plate, and a printing platform is mounted on the lead screw slider mechanism.

[0040] Preferably, the submicron-level XY-axis displacement stage can be a commercially available submicron-level electrically controlled displacement stage.

[0041] Preferably, the number of support rods is eight.

[0042] Preferably, the number of vibration isolation pads is 8.

[0043] A method for photopolymerization bio-3D printing using the apparatus described in any of the above technical solutions, comprising:

[0044] (1) The computer slices the 3D model to be printed and divides each slice of the model into image regions of different sizes that are adapted to the working surfaces of projection lens I and projection lens II.

[0045] (2) For each slice in the model, precise movement control is performed using a submicron-level XY-axis displacement stage to stitch the segmented image areas together, and the objective lens is switched to change the area to print different sizes of regions. Each slice is then exposed and cured to complete the printing of one layer of slices.

[0046] (3) Then the printing platform and drive components drive the printing platform to raise the height of one layer of slices, and perform the next layer of photocuring printing. The newly cured layer of material is firmly bonded to the surface of the previous layer of material. This cycle is repeated until the printing of the entire model is completed.

[0047] Preferably, in step (1), the computer simultaneously generates the movement path information of the submicron-level XY-axis displacement stage to guide the submicron-level XY-axis displacement stage to achieve the final splicing of the panels.

[0048] Compared with the prior art, the beneficial effects of the present invention are as follows: the dual-lens combined projection-type photopolymerization bio-3D printing device uses collimated laser as the light source, avoiding a redundant lens system, and adopts a sleeve lens combined with a projection lens design, which has a good imaging effect. Furthermore, the printing accuracy and size can be flexibly and effectively controlled by switching the projection lens on the lens converter, so as to achieve high-resolution and high-speed printing of bio-ink materials. Attached Figure Description

[0049] Figure 1 This is a schematic diagram of the structure of a dual-lens combined projection-type photopolymerization biological 3D printing device according to the present invention.

[0050] Figure 2 This is a schematic diagram of the laser source device in this invention.

[0051] Figure 3 This is a schematic diagram of the laser inclined plane structure in this invention.

[0052] Figure 4 This is a schematic diagram of the specific structure of the objective lens converter in this invention.

[0053] In the figure, 1. Laser source device; 101. 405nm laser; 102. TIR prism; 103. DMD chip; 104. Laser support; 105. Angle tilting platform; 106. Z-axis lifting stage; 107. Laser inclined plane; 2. Sleeve lens; 3. Objective lens converter; 4. Projection objective lens I; 5. Projection objective lens II; 6. Printing material tank; 7. Printing platform; 8. Lead screw and slider mechanism; 9. Top plate; 10. Objective lens mounting arm; 11. Submicron-level XY-axis displacement stage; 12. Support rod; 13. Base plate; vibration isolation pad. Detailed Implementation

[0054] The technical solution of this application will be described in detail below with reference to the accompanying drawings.

[0055] See Figure 1 A dual-lens combined projection-type photopolymerization bio-3D printing device, comprising:

[0056] Laser light source device 1: used to project slice patterns of three-dimensional objects;

[0057] The submicron-level XY-axis displacement stage 11 is used to move the laser source device in the XY-axis direction, adjust the relative position of the projected pattern and the exposure surface of the material tank, and splice the printing area.

[0058] Objective lens mounting arm 10: fixed on submicron XY axis displacement stage 11, used to mount objective lens converter 3 and its components;

[0059] Objective lens converter 3: It has a sleeve lens installed at the bottom and two objectives installed at the top, which are used to switch objectives to change the printing accuracy and size;

[0060] Sleeve lens 2: As an imaging lens, it is used in conjunction with the projection lens to form an infinity optical correction system;

[0061] Projection lens I4: Used to receive the light pattern and project it onto the exposure surface at the bottom of the feed tank;

[0062] Projection lens II 5: Used to receive light patterns and project them onto the exposure surface at the bottom of the material tank; the magnification of the projection lens is different from that of projection lens I 4;

[0063] The printing material tank 6 and the printing platform 7 function and work in the same way as traditional photopolymer 3D printers. The vertical movement of the printing platform 7 is achieved through the lead screw and slider mechanism 8, and the laser light source device 1 is used to achieve layer-by-layer printing on the printing platform 7.

[0064] The top plate 9 and the bottom plate 13 form the frame of the entire device through the support rod 12, which is used to install and fix the lead screw and slider mechanism 8 and the laser light source device 1. The bottom of the bottom plate 13 is provided with vibration isolation pads 14.

[0065] In actual installation, the submicron-level XY-axis displacement stage 11 is mounted on the base plate 13 via bottom threads. A laser source device 1 and an objective lens mounting arm 10 are mounted on the top of the submicron-level XY-axis displacement stage. The objective lens converter 3 is connected to the objective lens mounting arm 10 via locking screws. A sleeve lens 2 is mounted on the bottom of the objective lens converter 3, and projection lenses I 4 and II 5 with different magnifications are vertically mounted on the top of the objective lens converter 3. A vibration isolation pad 14 is mounted on the bottom of the base plate 13, and the base plate 13 is connected to the top plate 9 via a support rod 12. A printing material trough 6 and a lead screw slider mechanism 8 are fixed on the top plate 9, and a printing platform 7 is mounted on the lead screw slider mechanism 8.

[0066] See Figure 2-3 The laser source device 1 includes:

[0067] 405nm laser 101: Used to generate collimated rays for projection;

[0068] TIR prism 102: Used to correct the propagation path of light so that the outgoing optical axis is perpendicular to the DMD chip 103;

[0069] DMD chip 103;

[0070] Laser bracket 104: for mounting 405nm laser 101;

[0071] Angle tilting platform 105: used to correct the direction of the laser beam so that it coincides with the incident optical axis of the TIR prism 102;

[0072] Z-axis lifting platform 106: Used to correct the direction of laser beams emitted;

[0073] Laser inclined surface 107: The laser inclined surface 107 is arranged in an "L" shape and is used to install other laser source device components. Both the left and right ends of the top of the laser inclined surface have grooves extending towards the bottom surface, which are used to install the DMD chip 103 and the TIR prism 102, respectively. A limiting protrusion is provided on the groove corresponding to the 405nm laser 101 to fix the position of the TIR prism 102.

[0074] The installation of various components on the laser inclined plane enables the collimated laser emitted from the laser to pass through the TIR prism and enter the DMD chip. The light emitted from the DMD is totally reflected at the interface of the TIR prism and then emitted vertically from the side of the prism.

[0075] Figure 1 In this configuration, the outgoing optical axis of the TIR prism coincides with the optical axis of the sleeve lens and the projection lens II.

[0076] The working distances of projection lens I and projection lens II should be the same, and the structure and installation of the lens mounting arm should make the working distance of projection lens I and projection lens II the distance from the leading edge of the lens to the film in the feed tank.

[0077] like Figure 4 The diagram shows the specific structure of the objective lens turret 3. The objective lens turret 3 includes a mounting base 301 with a mounting cavity 307, an objective lens mounting plate 302 slidably mounted within the mounting cavity, and a servo motor 305 that drives the objective lens mounting plate 302 to move in a set direction. The objective lens mounting arm 10 is fixed to the mounting base 301. The bottom of the mounting cavity has a through-hole structure corresponding to the optical path. The objective lens mounting arm 10 also has a through-hole structure, and the bottom of the mounting base 301 has a mounting end that passes through the through-hole of the objective lens mounting arm 10. This end is fixed to the sleeve lens 2 via an adapter 306.

[0078] The mounting cavity of the mounting base 301 has a guide rail mechanism that mates with the objective lens mounting plate 302, enabling control of the movement direction of the objective lens mounting plate 302. The objective lens mounting plate 302 has mounting holes I 303 and II 304 for mounting projection lenses I and II, respectively. These holes can be fixed in the mounting holes I 303 and II 304 through keying, snap-fitting, or threaded engagement. Driven by the servo motor 305, the positions of projection lenses I and II can be adjusted to ensure that the projection lens (I or II) is coaxial with the sleeve lens 2 when in operation.

[0079] In practical applications, two objectives with different magnifications can be installed at a designated optical path position through the internal threads of mounting hole I 303 or mounting hole II 304, and fixed to the objective lens mounting arm 10 by the locking screws on the side. An adapter thread can be provided at the bottom mounting end of the mounting base 301 for installing the sleeve lens 2. Simultaneously, an adjusting screw can be provided at the objective lens mounting position on the mounting base 301 to ensure that the two objectives are in focus and in a relatively centered position. The objective lens converter uses a precision servo motor to switch objectives, retracting unused objectives to switch printing accuracy and format.

[0080] The implementation principle of the dual-lens combined projection photopolymerization bio-3D printing device in this application is as follows: During the 3D printing of bio-inks such as hydrogels using the dual-lens combined projection photopolymerization bio-3D printing device, a computer is used to slice the 3D model to be printed, and each slice in the model is divided into image areas of different sizes adapted to the working area of ​​each objective lens. For each slice in the model, precise movement control is achieved through a submicron-level XY-axis displacement stage 11, which stitches the segmented image areas together and switches the objective lenses to change the printing area to different sizes. Each slice is then exposed and cured to complete the printing of one slice. The printed material adheres to the bottom surface of the printing platform. Subsequently, the lead screw and slider mechanism 8 drives the printing platform 7 to raise the height of one slice, allowing for the photopolymerization printing of the next layer. The newly cured material adheres firmly to the surface of the previous layer. This process is repeated until the entire model is printed.

[0081] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A dual-lens combined projection-type photopolymerization bio-3D printing device, characterized in that, It includes a frame; and a printing platform and drive assembly, a feed trough, an optical system, and a laser light source device mounted on the frame and cooperating with each other, wherein the optical system includes: Projection lens I and projection lens II with different magnification; An objective lens converter for switching one of the projection objective lens I and projection objective lens II as the working objective lens, which simultaneously enables the installation of both projection objective lens I and projection objective lens II; A sleeve lens fixed to the bottom of the objective lens converter and aligned with the working objective lens; The exit end of the working objective lens is aligned with the printing platform and the material tank, and the entrance end of the sleeve lens is aligned with the exit end of the laser source device. The laser source device includes: Laser; Laser bevel; A Z-axis lifting platform fixed on the laser inclined plane for adjusting the Z-axis height of the laser; An angle tilting platform fixed on the Z-axis lifting platform for adjusting the Z-axis mounting angle of the laser; A laser bracket fixed on an angled platform for mounting the laser; The laser inclined plane is arranged in an "L" shape; the horizontal section of the "L" shape is used to fix the Z-axis lifting platform; the top of the vertical section of the "L" shape is fixed with a DMD chip and a TIR prism; the collimated laser emitted by the laser passes through the TIR prism and enters the DMD chip; the light emitted from the DMD chip is totally internally reflected at the interface of the TIR prism and then emitted vertically from the side of the prism, and is received by the optical system; The parfocal distances of projection lenses I and II are the same, and the working distance of projection lenses I and II is the distance from the leading edge of the lens to the film in the feed trough; the output optical axis of the TIR prism coincides with the optical axis of the sleeve lens and the working lens.

2. The dual-lens combined projection-type photopolymerization bio-3D printing device according to claim 1, characterized in that, The objective lens turret includes: Mounting base; A sliding objective lens mounting plate that can be mounted on a mounting base; A motor that drives the objective lens mounting plate to move in a set direction; The objective lens mounting plate is provided with mounting holes for mounting the projection objective lens I and the projection objective lens II. The working objective lens can be switched by moving the objective lens mounting plate driven by a motor.

3. The dual-lens combined projection-type photopolymerization bio-3D printing device according to claim 2, characterized in that, The mounting base has a mounting cavity, and the bottom of the mounting cavity has an optical path through hole aligned with the working objective lens; the objective lens mounting plate is disposed in the mounting cavity, and a matching guide rail mechanism is provided between the two.

4. The dual-lens combined projection-type photopolymerization bio-3D printing device according to claim 1, characterized in that, It also includes a submicron-level XY-axis displacement stage mounted on a frame; the optical system and laser source device are mounted on the submicron-level XY-axis displacement stage.

5. The dual-lens combined projection-type photopolymerization bio-3D printing device according to claim 1, characterized in that, The frame includes a top plate, a bottom plate, and a support rod that fixes the two together. The printing platform, drive components, and material trough are mounted on the top plate; The optical system, laser source device, and submicron-level XY-axis displacement stage are mounted on the base plate.

6. The dual-lens combined projection-type photopolymerization bio-3D printing device according to claim 1, characterized in that, The printing platform and driving components include: Lead screw and slider mechanism; A printing platform fixed on the slider of a lead screw and slider mechanism.

7. A method for photopolymerization bio-3D printing using the apparatus according to any one of claims 1 to 6, comprising: (1) The computer slices the 3D model to be printed and divides each slice of the model into image regions of different sizes that are adapted to the working surfaces of projection lens I and projection lens II. (2) For each slice in the model, precise movement control will be performed by a submicron-level XY-axis displacement stage to stitch the segmented image areas together, and the objective lens will be switched to change the area to print different sizes of areas. The slices will be exposed and cured separately to complete the printing of one layer of slices. (3) Then the printing platform and drive components drive the printing platform to raise the height of one layer of slices, and perform the next layer of photocuring printing. The newly cured layer of material is firmly bonded to the surface of the previous layer of material. This process is repeated until the printing of the entire model is completed.

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