Multi-light-spot batch 3D printing device and method

Abstract

The invention discloses a multi-light-spot batch 3D printing device and method, and belongs to the field of 3D printing, the device comprises at least one galvanometer scanning unit, and each galvanometer scanning unit is provided with a laser beam splitting unit; the laser beam splitting unit is used for splitting one laser beam into a plurality of laser beams so as to form a laser matrix, and the distance between adjacent laser beams in the laser matrix is adjusted; the galvanometer scanning unit is used for reflecting the laser matrix to the printing working face, the laser matrix scans on the printing working face by adjusting the reflection angle of the galvanometer scanning unit, and multiple parts are printed in batches. Under the condition that the number of the galvanometers and the number of the lasers are not increased, the printing speed of small parts can be increased, and the requirement for batch production is met.

Description

Technical Field

[0001] The present invention belongs to the field of 3D printing, and particularly relates to a multi-spot batch 3D printing device and method. Background Art

[0002] Laser 3D printing uses a single laser beam, which is reflected by a galvanometer module and then scanned layer by layer on the printing working surface to print patterns. According to different printing materials, there are currently several types such as SLA, SLS, and SLM. The methods adopted in SLA, SLS, and SLM in 3D printing are to reflect a single laser beam by a galvanometer and perform image scanning printing on a two-dimensional working plane. Compared with traditional subtractive manufacturing technologies, 3D printing technology is an advanced additive manufacturing technology for rapid manufacturing of parts.

[0003] The galvanometer system reflects the laser beam and has flexible control. It can print patterns of various shapes according to software requirements. In high-speed machining applications, the scanning speed of the galvanometer system has always restricted the improvement of processing efficiency. 3D printing has relatively high requirements for the printing laser. It requires the laser beam to be a pure single-mode output, and the beam quality M2 is less than 1.1. For lasers with high beam quality, the laser power is usually not high and cannot be further used to improve the printing efficiency. Moreover, the prices of these high-beam-quality lasers are very expensive.

[0004] In the application field of 3D printing, products that can be used for batch production are usually small-sized parts arranged in an array form, such as small parts in metal 3D printed 3C products. These parts are small in size and large in quantity. Usually, hundreds of identical parts are printed at one time to meet the requirements of batch production. However, traditional laser galvanometer systems all use one laser equipped with one galvanometer module to scan and print part patterns. The efficiency of printing part patterns with a single laser beam is very low. To improve the efficiency, the commonly used method is to use multiple laser galvanometer modules for printing, but this will inevitably lead to an increase in the volume and cost of the printing equipment.

[0005] Therefore, without increasing the number of galvanometers and lasers, improving the printing speed of small parts to meet the requirements of batch production is of great significance for the application and popularization of 3D printing. Summary of the Invention

[0006] The purpose of the present invention is to provide a multi-spot batch 3D printing device and method to solve the problem of low efficiency in printing batch parts by a single-laser 3D printing system.

[0007] To achieve the above purpose, the technical solution of the present invention is as follows: The present invention relates to a multi-spot batch 3D printing device, which includes at least one galvanometer scanning unit, and each group of the galvanometer scanning units is configured with a laser beam splitting unit; the laser beam splitting unit is used to split a laser beam into multiple laser beams, thereby forming a laser matrix and adjusting the spacing between adjacent laser beams in the laser matrix; the galvanometer scanning unit is used to reflect the laser matrix onto the printing work surface, and scan the laser matrix on the printing work surface by adjusting the reflection angle of the galvanometer scanning unit to batch print multiple parts.

[0008] Preferably, the laser beam splitting unit includes a concave lens group, a beam splitting prism, and a convex lens group arranged in sequence along the optical path of the laser beam; The concave lens group is used to diffuse the laser beam; The beam splitting prism is used to split the diffused laser beam into multiple laser beams to form a laser matrix; The convex lens group is used to collimate the laser beam diffused by the concave lens group; Moving the beam splitting prism back and forth along the propagation direction of the laser beam is used to adjust the spacing between adjacent laser beams in the laser matrix.

[0009] Preferably, the laser beam splitting unit includes a beam splitting prism and a variable magnification beam expander arranged in sequence along the optical path of the laser beam; The beam splitting prism is used to split the laser beam into multiple laser beams to form a laser matrix; The variable magnification beam expander adjusts the angle between adjacent laser beams in the laser matrix by adjusting the beam expansion ratio of the variable magnification beam expander, thereby changing the spacing between adjacent laser beams incident on the printing work surface.

[0010] Preferably, the beam splitting prism includes an incident surface and multiple exit surfaces. The incident surface is perpendicular to the direction in which the laser beam enters the beam splitting prism. The exit surfaces are centered on the axis of the laser beam, and the number of beam splittings in the XY two directions of the beam splitting prism is the same and symmetrically distributed. As the distance from the center of the beam splitting prism gradually increases, the tilt angle of the exit surface also increases in sequence, and the angle difference between the tilt angles of adjacent exit surfaces is the same.

[0011] Preferably, the beam splitting prism includes a plano lens and multiple beam splitting prism units, and the multiple beam splitting prism units are evenly distributed on the exit surface of the plano lens.

[0012] The present invention also relates to a multi-spot batch 3D printing method, which includes the following steps: S1. The laser beam splitting unit splits the vertically incident laser beam into multiple laser beams to form a laser matrix, and adjusts the spacing between adjacent laser beams in the laser matrix according to the distribution state of the batch printed parts; S2. The galvanometer scanning unit reflects the laser matrix to the F-Theta field lens. After being focused by the F-Theta field lens, it is projected onto the printing working surface to form a matrix printing light spot. By adjusting the reflection angle of the galvanometer scanning unit, the laser matrix is scanned on the printing working surface to batch-print multiple parts.

[0013] Preferably, the basis for adjusting the spacing between adjacent laser beams in the laser matrix according to the distribution state of the batch-printed parts in S1 is as follows: The batch-printed parts to be printed are arranged in an array. The spacing between two adjacent rows of batch-printed parts is N, and the spacing between two adjacent columns of batch-printed parts is M. Then, the spacing K between adjacent laser beams in the laser matrix is set to be an integer multiple of the least common multiple of M and N.

[0014] Preferably, the laser beam splitting unit includes a concave lens group, a beam splitting prism, and a convex lens group arranged in sequence along the laser beam optical path; in S1, the vertically incident laser beam is split into multiple laser beams to form a laser matrix. The specific steps for adjusting the spacing between adjacent laser beams in the laser matrix according to the distribution state of the batch-printed parts include: S1.1. The laser beam is diffused through the concave lens group. S1.2. The diffused laser beam is split into multiple laser beams through the beam splitting prism to form a laser matrix. S1.3. The laser beam diffused by the concave lens group is collimated through the convex lens group. S1.4. The beam splitting prism is moved back and forth along the laser beam propagation direction to adjust the spacing between adjacent laser beams in the laser matrix.

[0015] Preferably, the laser beam splitting unit includes a beam splitting prism and a variable magnification beam expander arranged in sequence along the laser beam optical path; in S1, the vertically incident laser beam is split into multiple laser beams to form a laser matrix. The specific steps for adjusting the spacing between adjacent laser beams in the laser matrix according to the distribution state of the batch-printed parts include: S1.1. The beam splitting prism splits the laser beam into multiple laser beams to form a laser matrix. S1.2. The variable magnification beam expander adjusts the included angle between adjacent laser beams in the laser matrix by adjusting the beam expansion ratio of the variable magnification beam expander, thereby changing the spacing between adjacent laser beams incident on the printing working surface.

[0016] Preferably, the galvanometer scanning unit includes an X-axis galvanometer and a Y-axis galvanometer, and the overlapping surface position of multiple laser beams of the laser matrix formed by the laser beam splitting unit is located between the X-axis galvanometer and the Y-axis galvanometer.

[0017] Adopting the technical solution provided by the present invention, compared with the prior art, it has the following beneficial effects: The multi-spot batch 3D printing device involved in the present invention is configured with a laser beam splitting unit for each galvanometer scanning unit. The laser beam splitting unit is used to split a laser beam into multiple laser beams, thereby forming a laser matrix, and adjusting the spacing between adjacent laser beams in the laser matrix. The galvanometer scanning unit is used to reflect the laser matrix onto the printing work surface and scan the laser matrix on the printing work surface by adjusting the reflection angle of the galvanometer scanning unit, so as to batch print multiple parts. Thus, without increasing the number of galvanometers and lasers, the printing speed of small parts can be improved to meet the requirements of batch production. Description of the Drawings

[0018] Figure 1 It is a schematic structural diagram of the multi-spot batch 3D printing device involved in Embodiment 1; Figure 2 is a schematic structural diagram of the beam splitting prism involved in Embodiments 1 and 2; Figure 3 is a schematic diagram of the height of the exit surface of the beam splitting prism involved in Embodiments 1 and 2; Figure 4 It is a schematic working principle diagram of the multi-spot batch 3D printing device involved in Embodiment 1; Figure 5 It is a schematic structural diagram of the multi-spot batch 3D printing device involved in Embodiment 2 Figure 6 It is a schematic working principle diagram of the multi-spot batch 3D printing device involved in Embodiment 2; Figure 7 It is an equivalent optical path diagram of the multi-spot batch 3D printing device; Figure 8 It is a schematic structural diagram of the beam splitting prism involved in Embodiment 3; Figure 9 It is a schematic principle diagram for adjusting the spacing between adjacent laser beams in the laser matrix; Figure 10 It is a schematic diagram of the combined printing of multiple groups of galvanometer scanning units and laser beam splitting units in Embodiment 4; Figure 11 It is a schematic diagram for adjusting a laser beam with uneven energy distribution into a laser beam with uniform energy.

[0019] Reference Numerals: 1 - concave lens group, 2 - beam splitting prism, 21 - incident surface, 22 - exit surface, 23 - plano-convex lens, 24 - beam splitting prism unit, 3 - convex lens group, 4 - variable magnification beam expander, 5 - galvanometer scanning unit, 51 - X-axis galvanometer, 52 - Y-axis galvanometer, 6 - F-Theta field lens. Detailed Embodiments

[0020] To further understand the content of the present invention, the present invention will be described in detail in combination with embodiments. The following embodiments are used to illustrate the present invention, but are not used to limit the scope of the present invention.

[0021] Example 1: The present invention relates to a multi-spot batch 3D printing device, which includes a galvanometer scanning unit 5 configured with a laser beam splitting unit. The laser beam splitting unit is used to split a laser beam into multiple laser beams, thereby forming a laser matrix and adjusting the spacing between adjacent laser beams in the laser matrix; the galvanometer scanning unit 5 is used to reflect the laser matrix onto the printing work surface and scan the laser matrix on the printing work surface by adjusting the reflection angle of the galvanometer scanning unit 5 to batch print multiple parts.

[0022] Refer to the attached Figure 1 As shown, the laser beam splitting unit in this embodiment includes a concave lens group 1, a beam splitting prism 2, and a convex lens group 3 arranged in sequence along the laser beam optical path; the concave lens group 1 is used to diffuse the laser beam; the beam splitting prism 2 is used to split the diffused laser beam into multiple laser beams to form a laser matrix; the beam splitting prism can be moved back and forth along the laser beam propagation direction to adjust the spacing between adjacent laser beams in the laser matrix; the convex lens group is used to collimate the laser beam diffused by the concave lens group.

[0023] Refer to the attached Figure 2 As shown, the beam splitting prism 2 involved in this embodiment includes an incident surface 21 and multiple exit surfaces 22. The incident surface 21 is perpendicular to the direction in which the laser beam enters the beam splitting prism 2. The exit surfaces 22 are centered on the axis of the laser beam and have the same number of splits and are symmetrically distributed in the XY two directions of the beam splitting prism 2. As the distance from the center of the beam splitting prism 2 gradually increases, the tilt angle of the exit surface 22 also increases in sequence, and the angular difference between the tilt angles of adjacent exit surfaces 22 is the same. Specifically: when the number of exit surfaces 22 is odd, the middle 0th exit surface 22 is parallel to the incident surface 21, and the direction of the laser beam emitted from the 0th exit surface 22 remains unchanged. The 1st, 2nd, 3rd, etc. exit surfaces 22 are symmetrically distributed outward in sequence, and their tilt angles increase in sequence, as shown in Figure 2 (a); when the number of exit surfaces 22 is even, the 1st, 2nd, 3rd, etc. exit surfaces 22 are symmetrically distributed outward in sequence, and their tilt angles increase in sequence, as shown in Figure 2 (b). For the incident laser beam, it can be a laser beam with equal light intensity or a laser beam with unequal light intensity. The specific setting method is as shown in Figure 3 As shown, assuming the total width of the incident light beam is H , the incident light beam is divided into n exit light beams, and the total width of the i th exit surface 22 is as shown above as Hi , and the laser energy distribution is f ( H ) Then Hi satisfies: , That is, the width of the exit surface 22 is based on the laser energy distribution. When the incident light beam is a light beam with a uniform energy distribution, the widths of all the exit surfaces 22 are equal, all being Hi = H / n ; when the energy distribution of the incident light beam is non-uniform, the widths of the exit surfaces 22 are also different. Taking a conventional Gaussian beam as an example, its central light beam is strong and the edge light beam is weak. Therefore, the width of the exit surface 22 close to the center of the light beam is small, and the width of the exit surface 22 close to the edge is large.

[0024] The multi-spot batch 3D printing method based on the above device includes the following steps: S1. The laser beam splitting unit splits the vertically incident laser beam into multiple laser beams to form a laser matrix, and adjusts the spacing between adjacent laser beams in the laser matrix according to the distribution state of the batch printing parts; Referring to the attached Figure 9 As shown, the basis for adjusting the spacing between adjacent laser beams in the laser matrix according to the distribution state of the batch printing parts is: arranging the batch printing parts to be printed in an array, the spacing between two adjacent rows of batch printing parts is N, and the spacing between two adjacent columns of batch printing parts is M. Then, it is set that the spacing K between adjacent laser beams in the laser matrix is equal to an integer multiple of the least common multiple of M and N, which is represented by the common symbol of the least common multiple as follows: K = k[M, N], where k is a natural integer, and [·] represents taking the least common multiple. For example, when M = 15 mm and N = 20 mm, then K can take values that are integer multiples of [15, 20] = 60 mm, such as 60 mm, 120 mm, etc.

[0025] Referring to the attached Figure 4 As shown, in this embodiment, the specific steps of S1 include: S1.1. The laser beam is diffused through the concave lens group 1. The initial radius of the laser beam is d0, and the radius of the laser beam after diffusion and entering the beam splitting prism 2 is d; S1.2. The diffused laser beam is split into multiple laser beams through the beam splitting prism 2 to form a laser matrix. The included angle between any one of the split laser beams and the incident laser beam is expressed as: ; wherein, α i is the deflection angle of the light beam emitted from the i-th exit surface 22, n is the refractive index of the material of the beam splitting prism 2, θ i is the inclination angle of the i -th exit surface 22. Since the angular difference between the inclination angles of adjacent exit surfaces 22 is the same, the included angle α between two adjacent split laser beams is also the same; S1.3. Collimate the laser beam diffused by the concave lens group through a convex lens group; S1.4. Move the beam splitting prism back and forth along the propagation direction of the laser beam to adjust the spacing between adjacent laser beams in the laser matrix. For any given beam splitting prism 2, the deflection angle of each exit surface 22 with respect to the beam is α a fixed value. By moving back and forth along the optical axis on the optical path, the equivalent spacings L1 and L2 between the beam splitting prism 2 and the concave lens group 1 and the convex lens group 3 are adjusted, thereby adjusting the β size of the exit light angle, and further adjusting the size of the spacing K of the imaging spots on the printing working surface.

[0026] S2. The galvanometer scanning unit 5 reflects the laser matrix to the F-Theta field lens 6. After being focused by the F-Theta field lens 6, it is projected onto the printing working surface to form a Figure 9 matrix printing spot as shown. By adjusting the reflection angle of the galvanometer scanning unit 5, the laser matrix is scanned on the printing working surface to batch print multiple parts.

[0027] In this embodiment, the galvanometer scanning unit 5 includes an X-axis galvanometer 51 and a Y-axis galvanometer 52. As Figure 7 shown, in order to reduce the size of the galvanometer reflection mirror, reduce the inertia and improve the frequency response, the overlapping surface position of the multiple laser beams of the laser matrix formed by the laser beam splitting unit is located between the X-axis galvanometer 51 and the Y-axis galvanometer 52.

[0028] Embodiment 2: The present invention relates to a multi-spot batch 3D printing device, which includes a galvanometer scanning unit 5 configured with a laser beam splitting unit. The laser beam splitting unit is used to split a laser beam into multiple laser beams, thereby forming a laser matrix, and adjust the spacing between adjacent laser beams in the laser matrix; the galvanometer scanning unit 5 is used to reflect the laser matrix onto the printing working surface, and scan the laser matrix on the printing working surface by adjusting the reflection angle of the galvanometer scanning unit 5 to batch print multiple parts.

[0029] Referring to the attached Figure 5 shown, the laser beam splitting unit in this embodiment includes a beam splitting prism 2 and a variable magnification beam expander 4 arranged in sequence along the optical path of the laser beam; the beam splitting prism 2 is used to split the laser beam into multiple laser beams to form a laser matrix; the variable magnification beam expander 4 adjusts the included angle between adjacent laser beams in the laser matrix by adjusting the beam expansion ratio of the variable magnification beam expander 4, thereby changing the spacing between adjacent laser beams incident on the printing working surface. The structure of the beam splitting prism 2 used in this embodiment is the same as that in Embodiment 1 and will not be elaborated in detail.

[0030] The multi-spot batch 3D printing method based on the above device includes the following steps: S1. The laser beam splitting unit splits the vertically incident laser beam into multiple laser beams to form a laser matrix, and adjusts the spacing between adjacent laser beams in the laser matrix according to the distribution state of the parts to be printed in batches; Refer to the appendix Figure 9 As shown, the basis for adjusting the spacing between adjacent laser beams in the laser matrix according to the distribution state of the parts to be printed in batches is as follows: Arrange the parts to be printed in batches in an array. The spacing between adjacent rows of parts to be printed in batches is N, and the spacing between adjacent columns of parts to be printed in batches is M. Then, set the spacing K between adjacent laser beams in the laser matrix to be an integer multiple of the least common multiple of M and N, which is represented by the common symbol for the least common multiple in mathematics as follows: K = k[M,N], where k is a natural integer. For example, when M = 15mm and N = 20mm, then K can take values that are integer multiples of [15,20] = 60mm, such as 60mm, 120mm, etc.

[0031] Refer to the appendix Figure 6 As shown, in this embodiment, the specific steps of S1 include: S1.1. The laser beam is split into multiple laser beams by the beam splitting prism 2 to form a laser matrix. The angle between any one of the split laser beams and the incident laser beam is expressed as: ; Among them, α i is the deflection angle of the light beam emitted from the i-th exit surface 22, n is the refractive index of the material of the beam splitting prism 2, θ i is the i inclination angle of the i-th exit surface 22. Since the angular difference between the inclination angles of adjacent exit surfaces 22 is the same, the angle α between adjacent split laser beams is also the same; S1.2. The variable magnification beam expander 4 adjusts the angle between adjacent laser beams in the laser matrix by adjusting the beam expansion ratio of the variable magnification beam expander 4, thereby changing the spacing between adjacent laser beams incident on the printing working surface. As Figure 6 shown, the function of the variable magnification beam expander 4 is to arbitrarily adjust the ratio of the diameter of the exit beam to the diameter of the incident beam, which can be expressed by the following formula, d · α = D · β where, d is the width of each laser beam after splitting, α is the angle between adjacent laser beams, D is the width of the laser beam after beam expansion by the variable magnification diffuser, βis the angle between two adjacent laser beams after beam expansion by the variable magnification diffusing lens. Therefore, by adjusting the beam expansion ratio of the variable magnification beam expander 4, the angle of the outgoing beam can be adjusted, β and thus the distance K between the imaging spots on the printing working surface can be adjusted.

[0032] In this embodiment, the galvanometer scanning unit 5 includes an X-axis galvanometer 51 and a Y-axis galvanometer 52. As Figure 7 shown, in order to reduce the size of the galvanometer reflection mirror, reduce the inertia and improve the frequency response, the overlapping surface position of the multiple laser beams of the laser matrix formed by the laser beam splitting unit is located between the X-axis galvanometer 51 and the Y-axis galvanometer 52.

[0033] S2. The galvanometer scanning unit 5 reflects the laser matrix to the F-Theta field lens 6. After being focused by the F-Theta field lens 6, it is projected onto the printing working surface to form a matrix printing spot as Figure 9 shown. By adjusting the reflection angle of the galvanometer scanning unit 5, the laser matrix is scanned on the printing working surface to batch print multiple parts.

[0034] Embodiment 3: Compared with Embodiment 1 and Embodiment 2, the structure of the beam splitting prism 2 used in this embodiment is different. Specifically, as Figure 8 shown, the beam splitting prism 2 in this embodiment includes a plano lens 23 and multiple beam splitting prism units 24. The multiple beam splitting prism units 24 are evenly distributed on the outgoing surface 22 of the plano lens 23.

[0035] Embodiment 4: Embodiments 1 to 3 all adopt a group of galvanometer scanning units 5 and a group of laser beam splitting units, while this embodiment uses multiple groups of galvanometer scanning units 5 and laser beam splitting units for combined printing. Each group of galvanometer scanning units 5 is correspondingly configured with a group of laser beam splitting units, as Figure 10 shown. Assuming there are N groups of galvanometers, the number of beams split by each group of galvanometers is M. The printing working surface is divided into M small printing areas. Each outgoing laser beam of the N galvanometers is responsible for one printing area. In each printing area, N laser beams jointly complete the printing of the pattern, and the remaining M areas synchronously complete the same printing work. The printing method of this embodiment can perform the simultaneous printing of the patterns in M printing areas, and in each printing area, N laser beams jointly print the pattern in one area. At this time, the printing efficiency is increased by M*N times compared with the single-beam laser printing pattern.

[0036] Embodiment 5 As known from the content of Embodiment 1, for the incident laser beam, it can be a laser beam with equal light intensity or a laser beam with unequal light intensity. When the incident laser is a laser beam with unequal light intensity, the energies of multiple laser beams in the laser matrix emitted from the beam splitter prism 2 are also uneven. At this time, the energy of the laser beam can be adjusted to a uniformly distributed energy by adjusting the tilt angle of the beam splitter prism 2. For example, Figure 11 As shown, taking the 4 lasers with a 2*2 distribution after beam splitting as an example, when the incident laser beam is eccentric to the right, the powers of beam 2 and beam 4 will increase, and the powers of beam 1 and beam 3 will decrease. The opposite is true when the incident beam is eccentric to the left; similarly, when the incident laser beam is eccentric downward, the powers of beam 3 and beam 4 will increase, and the powers of beam 1 and beam 2 will decrease, and vice versa. The steps to adjust the beam energy are as follows: 1. Adjust the left and right positions of the incident laser beam so that the power of beam 1 + beam 3 = the power of beam 2 + beam 4; 2. Adjust the up and down positions of the laser beam so that the power of beam 1 + beam 2 = the power of beam 3 + beam 4; Since the incident light is a beam symmetric about the center of the circle, the above two steps can adjust the energies of the 4 laser beams to the same value. When the energy distribution of the incident laser beam is asymmetric, the third step can be added: 3. Taking the center of the beam splitter prism 2 as the origin, rotate the prism, and observe the powers of the 4 laser beams and adjust until the energies of the 4 laser beams are the same or the difference value is less than the error required for printing.

[0037] The present invention has been described in detail above in conjunction with the embodiments, but the above content is only the preferred embodiment of the present invention and cannot be considered as limiting the scope of implementation of the present invention. All equivalent changes and improvements made according to the scope of the application of the present invention should still fall within the scope covered by the patent of the present invention.

Claims

1. A multi-spot batch 3D printing device, which includes at least one galvanometer scanning unit, characterized in that: Each galvanometer scanning unit in each group is configured with a laser beam splitting unit; the laser beam splitting unit is used to split a laser beam into multiple laser beams, thereby forming a laser matrix and adjusting the spacing between adjacent laser beams in the laser matrix; the galvanometer scanning unit is used to reflect the laser matrix onto the printing working surface and scan the laser matrix on the printing working surface by adjusting the reflection angle of the galvanometer scanning unit to batch-print multiple parts.

2. The multi-spot batch 3D printing device according to claim 1, characterized in that: The laser beam splitting unit includes a concave lens group, a beam splitting prism, and a convex lens group sequentially arranged along the laser beam optical path; The concave lens group is used to diffuse the laser beam; The beam splitting prism is used to split the diffused laser beam into multiple laser beams to form a laser matrix; The convex lens group is used to collimate the laser beam diffused by the concave lens group; Moving the beam splitting prism back and forth along the laser beam propagation direction is used to adjust the spacing between adjacent laser beams in the laser matrix.

3. The multi-spot batch 3D printing device according to claim 1, characterized in that: The laser beam splitting unit includes a beam splitting prism and a variable magnification beam expander sequentially arranged along the laser beam optical path; The beam splitting prism is used to split the laser beam into multiple laser beams to form a laser matrix; The variable magnification beam expander adjusts the included angle between adjacent laser beams in the laser matrix by adjusting the beam expansion ratio of the variable magnification beam expander, thereby changing the spacing between adjacent laser beams incident on the printing working surface.

4. The multi-spot batch 3D printing device according to claim 2 or 3, characterized in that: The beam splitting prism includes an incident surface and multiple exit surfaces. The incident surface is perpendicular to the direction in which the laser beam enters the beam splitting prism. The exit surfaces are centered on the axis of the laser beam, and the number of splits in the XY two directions of the beam splitting prism is the same and symmetrically distributed. As the distance from the center of the beam splitting prism gradually increases, the tilt angle of the exit surface also increases sequentially, and the angular difference between the tilt angles of adjacent exit surfaces is the same.

5. The multi-spot batch 3D printing device according to claim 2 or 3, characterized in that: The beam splitting prism includes a plano-convex lens and multiple beam splitting prism units, and the multiple beam splitting prism units are evenly distributed on the exit surface of the plano-convex lens.

6. A multi-spot batch 3D printing method, characterized in that, It includes the following steps: S1. The laser beam splitting unit splits the vertically incident laser beam into multiple laser beams to form a laser matrix, and adjusts the spacing between adjacent laser beams in the laser matrix according to the distribution state of the batch-printed parts; S2. The galvanometer scanning unit reflects the laser matrix to the F-Theta field lens, and after being focused by the F-Theta field lens, projects it onto the printing working surface to form a matrix printing light spot, and scans the laser matrix on the printing working surface by adjusting the reflection angle of the galvanometer scanning unit to batch-print multiple parts.

7. The multi-spot batch 3D printing method according to claim 6, wherein: The basis for adjusting the spacing between adjacent laser beams in the laser matrix according to the distribution state of the batch-printed parts in S1 is: Arrange the batch-printed parts in an array. The spacing between two adjacent rows of batch-printed parts is N, and the spacing between two adjacent columns of batch-printed parts is M. Then set the spacing K between adjacent laser beams in the laser matrix to be an integer multiple of the least common multiple of M and N.

8. The multi-spot batch 3D printing method according to claim 7, characterized in that: The laser beam splitting unit includes a concave lens group, a beam splitting prism, and a convex lens group sequentially arranged along the laser beam optical path; in S1, the specific steps of splitting the vertically incident laser beam into multiple laser beams to form a laser matrix and adjusting the spacing between adjacent laser beams in the laser matrix include: S1.

1. The laser beam is diffused by a concave lens group; S1.

2. The diffused laser beam is split into multiple laser beams by a beam splitting prism to form a laser matrix; S1.

3. The laser beam diffused by the concave lens group is collimated by a convex lens group; S1.

4. Move the beam splitting prism back and forth along the propagation direction of the laser beam to adjust the spacing between adjacent laser beams in the laser matrix.

9. The multi-spot batch 3D printing method according to claim 7, characterized in that: The laser beam splitting unit includes a beam splitting prism and a variable magnification beam expander arranged in sequence along the optical path of the laser beam; in S1, the specific steps of splitting the vertically incident laser beam into multiple laser beams to form a laser matrix and adjusting the spacing between adjacent laser beams in the laser matrix according to the distribution state of the batch printed parts include: S1.

1. The beam splitting prism splits the laser beam into multiple laser beams to form a laser matrix; S1.

2. The variable magnification beam expander adjusts the angle between adjacent laser beams in the laser matrix by adjusting the beam expansion ratio of the variable magnification beam expander, thereby changing the spacing between adjacent laser beams incident on the printing working surface.

10. The multi-spot batch 3D printing method according to claim 6, characterized in that: The galvanometer scanning unit includes an X-axis galvanometer and a Y-axis galvanometer, and the overlapping surface position of the multiple laser beams of the laser matrix formed by the laser beam splitting unit is located between the X-axis galvanometer and the Y-axis galvanometer.

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