System and method for variable focal spot with constant power density

Abstract

The invention provides a system and a method for changing focal spots with constant power density. The system for changing focal spots with constant power density comprises a laser light source, a collimating mirror, a first reflector, a double-slit device, a second reflector, a third reflector and a focusing lens which are sequentially arranged along a light path direction, wherein the double-slit device comprises a first slit and a second slit, the width of the first slit and the width of the second slit are adjustable, and the first slit and the second slit are jointly used for adjusting the size of a light spot. By arranging the double-slit device and the rotating device, the width and angle of the double slits are adjusted, so that the size of a light spot is adjusted, the printing line width and direction are adjusted, the energy density is not changed in the adjusting process, only the size of the light spot is changed, the printing quality is not affected while the printing precision is improved by changing the line width, and the printing efficiency is improved. The printing efficiency is improved and the printing precision is ensured.

Description

[0001] This invention patent application is a divisional application of the invention patent application with an application date of 2024.03.19, an application number of 202410314115.1, and an invention name of "System, method and 3D printing method using constant power density variable focal spot". Technical Field

[0002] The present invention relates to the technical field of 3D printing, and in particular to a system and method for a constant power density variable focal spot. Background Art

[0003] 3D printing technology is a new material forming technology for printing products based on the idea of ​​discrete stacking. Its principle is to first establish a three-dimensional model of the product, then layer the three-dimensional model according to a certain layer thickness and line width and perform path planning, and finally print the product layer by layer according to the planned path. According to the principle of 3D printing technology, line width is a key factor affecting the forming efficiency and printing accuracy of the product. When the line width is small, the printing accuracy of the product is high, but the forming efficiency is low; when the line width is large, the forming efficiency of the product is high, but the printing accuracy is low.

[0004] At present, in order to adjust the printing line width in 3D printing, a zoom lens is usually set on the laser light path. The zoom lens can adjust the printing line width by adjusting the spot size, but this method will cause the energy density to change, thereby affecting the printing effect. Summary of the invention

[0005] In view of the above problems, the present invention proposes a system and method for a constant power density variable focal spot.

[0006] In order to solve at least one of the above technical problems, the present invention proposes the following technical solution:

[0007] In a first aspect, a system for a constant power density variable focus spot is provided, comprising a laser light source, a collimating mirror, a first reflector, a double slit device, a second reflector, a third reflector and a focusing lens arranged in sequence along the optical path; wherein the double slit device comprises a first slit, a second slit and a slit rotating stage, the first slit and the second slit are arranged vertically, the widths of the first slit and the second slit are adjustable, the first slit and the second slit are used together to adjust the size of the light spot, and the slit rotating stage is used to adjust the angles of the first slit and the second slit so that the directions of the first slit and the second slit adapt to the scanning angle.

[0008] In a second aspect, a method for a constant power density variable focal spot is provided, which uses any of the above constant power density variable focal spot systems, comprising the following steps:

[0009] Obtaining the size of the light spot required for the current printing action, adjusting the widths of the first slit and the second slit so that the intersection area of ​​the first slit and the second slit meets the size requirement of the light spot, and adjusting the angle of the first slit and the second slit so that the directions of the first slit and the second slit adapt to the scanning angle;

[0010] The laser light source is controlled to emit a laser beam, which passes through a collimating mirror, a first reflecting mirror, a double slit device, a second reflecting mirror, a third reflecting mirror and a focusing lens in sequence and is emitted to a printing working surface.

[0011] In a third aspect, a 3D printing method is provided, using any of the above constant power density variable focus spot systems, comprising the following steps:

[0012] Calculate the width of each printed line according to the printing task;

[0013] According to the width of the i-th printing line, the widths of the first slit and the second slit are adjusted so that the size of the light spot emitted by the focusing lens meets the width requirement of the i-th printing line, where i=1, 2, 3, 4...j, and j represents the total number of reprinted lines in the current printing task;

[0014] The laser light source emits a laser beam, which sequentially passes through a collimator, a first reflector, a double slit device, a second reflector, a third reflector and a focusing lens and is directed toward a printing work surface to generate an i-th printing line.

[0015] In a fourth aspect, a 3D printing device is provided, applying any of the above 3D printing methods, including a line width calculation module for calculating the width of each printed line according to a printing task;

[0016] A constant power density zoom spot system, a laser light source, a collimator, a first reflector, a double slit device, a second reflector, a third reflector and a focusing lens are sequentially arranged along the optical path direction, the double slit device comprises a first slit, a second slit and a slit rotating stage, the widths of the first slit and the second slit are adjustable, the angles of the first slit and the second slit are adjustable, the laser light source emits a laser beam, the laser beam sequentially passes through the collimator, the first reflector, the double slit device, the second reflector, the third reflector and the focusing lens to be emitted to a printing working surface to generate printing lines;

[0017] The double slit device control module is used to adjust the width of the first slit and the second slit according to the width of the printed line, so that the size of the output light spot of the focusing lens meets the width requirement of the current printed line.

[0018] The beneficial effects of the present invention are:

[0019] (1) By setting up a double slit device and a rotating device, the width and angle of the double slits can be adjusted, thereby adjusting the size of the light spot and then adjusting the printing line width. During the adjustment process, the energy density is not changed, only the size of the light spot is changed, which meets the processing requirements of variable line width without affecting the printing effect, improves printing efficiency, and ensures printing quality;

[0020] (2) Different printing accuracy requirements for the same printing task are distinguished, and line widths are calculated according to different printing requirements, so as to avoid the situation where the overall accuracy does not meet the printing requirements or the efficiency is low due to the use of the same line width under different accuracy requirements, thereby ensuring the printing quality and improving the printing efficiency;

[0021] (3) Calculate and split the printing residue to avoid the current processing equipment being unable to process the printing residue and affecting the printing accuracy and printing effect, thereby further improving the printing quality.

[0022] In addition, in the technical solution of the present invention, unless otherwise specified, the technical solution can be implemented by adopting conventional means in the art. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0024] Figure 1 A schematic structural diagram of a system for a constant power variable focal spot according to an embodiment of the present invention.

[0025] Figure 2 This is a schematic structural diagram of a double-slit device provided in Example 1 of the present invention.

[0026] Figure 3 A schematic structural diagram of a system for a constant power variable focal spot according to another embodiment of the present invention.

[0027] Figure 4 This is a flow chart of the method for constant power variable focus spot provided in Example 3 of the present invention.

[0028] Figure 5 A schematic diagram of the structure of a printing working surface in a constant power variable focus spot system provided by an embodiment of the present invention.

[0029] Figure 6 A schematic diagram of printed lines when filling overlap occurs in a 3D printing method provided in an embodiment of the present invention.

[0030] Figure 7 A schematic diagram of a printing line when a printing gap occurs in a 3D printing method provided in an embodiment of the present invention.

[0031] Figure 8 This is a flow chart of the 3D printing method provided in Example 5 of the present invention.

[0032] Fig. 9 A flowchart of a specific method for calculating the width of each printed line according to a printing task in the 3D printing method provided in Example 6 of the present invention.

[0033] Fig.10 This is a schematic diagram of the structure of the 3D printing device provided in Example 7 of the present invention. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are part of the embodiments of the present invention, rather than all of the embodiments, and are only used to explain the present invention, and are not used to limit the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0035] It should be noted that the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or server that includes a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units that are not explicitly listed or are inherent to these processes, methods, products or devices.

[0036] Embodiment 1:

[0037] Reference Manual Attached Figure 1 , shows a system of constant power density variable focus spot provided by an embodiment of the present invention.

[0038] The system of constant power density zoom spot includes:

[0039] A laser light source 1, a collimating mirror 2, a first reflecting mirror 3, a double slit device 4, a second reflecting mirror 5, a third reflecting mirror 6 and a focusing lens 7 are arranged in sequence along the optical path direction.

[0040] The double slit device 4 includes a first slit and a second slit, the first slit and the second slit are vertically arranged, the widths of the first slit and the second slit are adjustable, the first slit and the second slit are used together to adjust the size of the light spot, and the area where the first slit and the second slit intersect is the area where the laser beam can pass, that is, the size of the light spot. The adjustable widths of the first slit and the second slit enable the size of the light spot to be adjustable.

[0041] When the laser light source 1 emits a laser beam, the laser beam passes through the collimator 2 , the first reflector 3 , the double slit device 4 , the second reflector 5 , the third reflector 6 and the focusing lens 7 in sequence, and is emitted to the printing work surface 9 .

[0042] In an optional embodiment, the double slit device may include a first light bar, a second light bar, a third light bar and a fourth light bar, the opposite sides of the first light bar and the second light bar are parallel to form a first slit; the opposite sides of the third light bar and the fourth light bar are parallel to form a second slit.

[0043] Reference Manual Attached Figure 2 , which schematically shows the front structure of the double slit device, the dotted line area represents the first light barrier plate 41 and the second light barrier plate 42, and the solid line area represents the third light barrier plate 43 and the fourth light barrier plate 44.

[0044] Specifically, one of the first light barrier sheet and the second light barrier sheet can be set to be fixed, and the other light barrier sheet can be set to be movable, and the width of the first slit can be adjusted by controlling the movement of the movable light barrier sheet.

[0045] Alternatively, the first light barrier sheet and the second light barrier sheet are both movable optical cable sheets, and the width of the first slit is adjusted by controlling the movement of the first light barrier sheet or the second light barrier sheet or the first light barrier sheet and the second light barrier sheet to move simultaneously but at different speeds.

[0046] Specifically, one of the third light barrier sheet and the fourth light barrier sheet can be set to be fixed, and the other light barrier sheet can be set to be movable, and the width of the second slit can be adjusted by controlling the movement of the movable light barrier sheet.

[0047] Alternatively, the third light barrier sheet and the fourth light barrier sheet are both movable optical cable sheets, and the width of the second slit can be adjusted by controlling the movement of the third light barrier sheet or the fourth light barrier sheet or the third light barrier sheet and the fourth light barrier sheet to move simultaneously but at different speeds.

[0048] In an optional embodiment, the constant power density variable focus spot system includes a control module, which is electrically connected to the double slit device 4 and is used to control the width change of the first slit and the second slit to achieve adjustment of the spot size.

[0049] Specifically, the movable light barrier pieces among the first light barrier piece, the second light barrier piece, the third light barrier piece and the fourth light barrier piece are respectively connected with driving motors, and the driving motors drive the corresponding light barrier pieces to move so as to change the widths of the first slit and the second slit.

[0050] The constant power density variable focal spot system provided in this embodiment has the following beneficial effects:

[0051] By setting up a double slit device, the width of the double slit is adjusted, and the size of the light spot is adjusted in a two-dimensional plane, thereby adjusting the printing line width. During the adjustment process, the energy density is not changed, only the size of the light spot is changed, which meets the processing requirements of variable line width while not affecting the printing effect, improving the printing efficiency and ensuring the printing quality. The light spot size is adjusted from different directions through the first slit and the second slit, so that the adjustable range of the light spot is wider, thereby improving the application range of the constant power density variable focus spot system.

[0052] Embodiment 2:

[0053] Reference Manual Attached Figure 3 , shows a system of constant power density variable focus spot provided by an embodiment of the present invention.

[0054] The system of constant power density zoom spot includes:

[0055] A laser light source 1, a collimating mirror 2, a first reflecting mirror 3, a double slit device 4, a second reflecting mirror 5, a third reflecting mirror 6, a focusing lens 7 and a rotating device 8 are arranged in sequence along the optical path direction.

[0056] Among them, the double slit device 4 includes a first slit, a second slit and a slit rotating table, wherein the first slit and the second slit can be arranged vertically, the width of the first slit and the second slit is adjustable, the first slit and the second slit are used together to adjust the size of the light spot, the area where the first slit and the second slit intersect is the area where the laser beam can pass, that is, the size of the light spot, and the adjustable size of the light spot is achieved by adjusting the width of the first slit and the second slit; the slit rotating table is used to adjust the angle of the first slit and the second slit so that the directions of the first slit and the second slit can adapt to the scanning angle, and the rotating device 8 is used to drive the first slit, the second slit and the slit rotating table to rotate, so as to achieve angle adjustment of the first slit and the second slit, so that the directions of the first slit and the second slit are consistent with the scanning direction to meet the printing requirements.

[0057] In an optional embodiment, the double slit device may include a first light bar, a second light bar, a third light bar, a fourth light bar and a slit rotating table, wherein the opposite sides of the first light bar and the second light bar are parallel to form a first slit; the opposite sides of the third light bar and the fourth light bar are parallel to form a second slit.

[0058] The slit rotating table can be connected to the first light bar, the second light bar, the third light bar and the fourth light bar respectively. Under the action of the rotating device 8, the slit rotating table can drive the first light bar, the second light bar, the third light bar and the fourth light bar to rotate with the center of the intersection area of ​​the first slit and the second slit as the rotation center point. The direction of rotation can be toward the first reflector 3 or away from the first reflector 3. Thereby, the effect of adjusting the angle of the first slit and the second slit can be achieved, so that the direction of the first slit and the second slit is the same as the scanning angle, meeting the printing requirements.

[0059] Specifically, the rotating device 8 may be a power device, such as a cylinder, etc. The rotating device 8 drives the slit rotating platform to rotate, and then drives the first slit and the second slit to rotate, so as to adjust the angles of the first slit and the second slit.

[0060] Reference Manual Attached Figure 3 , the dotted line in the figure is a possible form of the double slit device 4 after rotation, wherein the angle between the plane where the first slit and the second slit are located and the horizontal plane is θ.

[0061] In an optional embodiment, the rotating device 8 may be disposed on one side of the double slit device 4. Specifically, the rotating device 8 may be disposed above or below the double slit device 4, or the rotating device 8 may be disposed on the side of the double slit device 4 facing the first reflector 3 or facing away from the first reflector 3. In order to facilitate wiring, the rotating device 8 is generally disposed below the double slit device 4 or on the side facing away from the first reflector 3. The rotating device 8 may be any mechanical mechanism in the prior art that can drive the double slit device to rotate to achieve the angle change of the plane where the first slit and the second slit are located, and will not be described in detail herein.

[0062] In an optional embodiment, the system of constant power density variable focal spot includes a control module, which is electrically connected to the rotating device 8, and is used to control the movement of the rotating device to achieve angle change of the plane where the first slit and the second slit are located.

[0063] For technical details not described in detail in this embodiment, please refer to the system provided in Embodiment 1 of the present invention.

[0064] The constant power density variable focal spot system provided in this embodiment has the following beneficial effects:

[0065] By setting up a double slit device and a rotating device, the width and angle of the double slits can be adjusted in three-dimensional space, thereby adjusting the size of the light spot and then adjusting the printing line width. During the adjustment process, the energy density is not changed, only the size of the light spot is changed, which meets the processing requirements of variable line width while not affecting the printing effect, improving the printing efficiency and ensuring the printing quality. The light spot size is adjusted from different directions through the first slit and the second slit, so that the adjustable range of the light spot is wider, thereby improving the application range of the system of constant power density variable focus spot.

[0066] Embodiment 3:

[0067] Reference Manual Attached Figure 4 , shows a method for a constant power density zoom spot provided by an embodiment of the present invention, and a system for a constant power density zoom spot provided by any of the above embodiments is applied, comprising the following steps:

[0068] Step 3.1: Obtain the size of the light spot required for the current printing action, and adjust the widths of the first slit and the second slit so that the intersection area of ​​the first slit and the second slit meets the light spot size requirement;

[0069] Step 3.2: Control the laser light source to emit a laser beam, which passes through the collimator, the first reflector, the double slit device, the second reflector, the third reflector and the focusing lens in sequence and is emitted to the printing work surface.

[0070] In an optional embodiment, after the size of the light spot required for the current printing action is obtained, the width and angle of the first slit and the second slit are adjusted so that the intersection area of ​​the first slit and the second slit meets the size requirement of the light spot.

[0071] It should be understood that the method provided in this embodiment is of the same concept as the aforementioned system embodiment, and its specific implementation process is detailed in the system embodiment, which will not be repeated here.

[0072] The constant power density variable focus spot method provided in this embodiment has the following beneficial effects:

[0073] By setting up a double slit device, the width and angle of the double slits can be adjusted, thereby realizing the adjustment of the size and direction of the light spot, and then adjusting the printing line width. During the adjustment process, the energy density is not changed, only the size of the light spot is changed, which meets the processing requirements of variable line width while not affecting the printing effect, improving the printing efficiency and ensuring the printing quality. The light spot size is adjusted from different directions through the first slit and the second slit respectively, so that the adjustable range of the light spot is wider, and the application range of the system of constant power density variable focus spot is improved.

[0074] Embodiment 4:

[0075] An embodiment of the present invention provides a 3D printing method, using any of the above-mentioned systems of constant power density variable focal spot, comprising the following steps:

[0076] Step 1: Calculate the width of each printed line according to the printing task;

[0077] Step 2: Adjust the double slit device in the system of constant power density zoom spot so that the size of the light spot meets the requirement of printing line width. The laser light source emits a laser beam, which passes through the collimator, the first reflector, the double slit device, the second reflector, the third reflector and the focusing lens in sequence to the printing work surface, and generates printing lines in sequence.

[0078] Step 3: Calculate the printed width. When the printed width is not equal to the preset printed line width, calculate the difference between the two, recalculate the width of the remaining unprinted lines, and adjust the double slit device in the constant power density zoom spot system so that the spot size meets the new line width requirement and continue printing.

[0079] Therefore, by recalculating the print line width and controlling the double slit device to change the line width, the problem of the remaining print width being inconsistent with the predetermined line width due to filling overlap in the actual production process can be solved. When filling overlap occurs during printing, the print line width can be adjusted to meet the actual print width. Since the energy density can be kept unchanged and the print line width can be changed during the printing process, the printing accuracy and quality are guaranteed, and the printing efficiency is improved.

[0080] In an optional embodiment, step 3 may be performed when only one print line remains to be printed, thereby minimizing the number of line width changes, reducing the number of double slit device adjustments, and improving printing efficiency.

[0081] In an optional embodiment, after the current printing task is completed, the following steps may also be included:

[0082] Get the printout after the current print task is completed, and determine whether there is a gap between the print lines of the current printout;

[0083] If there is a gap, get the gap width;

[0084] The double slit device in the system of constant power density zoom spot is adjusted so that the size of the light spot meets the gap width. The laser light source emits a laser beam, which passes through the collimator, the first reflector, the double slit device, the second reflector, the third reflector and the focusing lens in sequence and is directed toward the printed part to complete the line filling.

[0085] In this way, the problem of gaps occurring during the printing process can be solved. The printing line width can be adjusted to meet the width of the gaps, and the gaps can be filled to ensure the printing effect and printing quality.

[0086] For details, please refer to the attached manual. Figure 5-7 , the 3D printing method provided in this embodiment is illustrated by way of example.

[0087] Reference Manual Attached Figure 5 , which shows a schematic diagram of the specific structure of the printing work surface 9. The printing work surface 9 may include a powder chamber 91, a molding chamber 92 and a scraper 93, wherein the powder chamber 91 and the molding chamber 92 are arranged in parallel below the printing work surface 9, the upper end of the powder chamber 91 is open, and the powder chamber 91 is used to store metal powder for printing, and the bottom surface of the powder chamber 91 is provided with a top plate 911 that can move up and down in a vertical direction, and a first transmission rod 912 is arranged below the top plate, and the first transmission rod 912 can be connected to a motor to drive the top plate 911 to move up and down, and push the metal powder in the powder chamber 91 out of the powder chamber 91; the upper end of the molding chamber 92 is a top plate 921 that can move up and down, and a second transmission rod 922 is arranged below the top plate 921, and the second transmission rod 922 can be connected to a motor to drive the top plate 921 to move up and down, and the scraper 93 is arranged on the side of the powder chamber 91 away from the molding chamber 92. When executing a printing task, according to a pre-calculated or set layer thickness, the first transmission rod 912 drives the ejection plate 911 to move upward, ejecting the metal powder in the powder chamber 91 out of the powder chamber 91 , and the scraper 93 moves toward the molding chamber 92 to spread the metal powder flat on the top plate 921 .

[0088] At this time, the width of each printed line is calculated according to the printing task, and the double slit device in the constant power density zoom spot system is adjusted to make the size of the light spot meet the requirements of the printing line width. The laser light source emits a laser beam, which passes through the collimator, the first reflector, the double slit device, the second reflector, the third reflector and the focusing lens in sequence to the printing work surface, and generates printing lines in sequence. When the printing of this layer is completed, the second transmission rod 922 drives the top plate 921 to move downward, so that the printed layer enters the molding cavity 92, and the above steps are repeated to print other layers.

[0089] Reference Manual Attached Figure 6, shows a schematic diagram of printed lines when filling overlap occurs, wherein Figure (a) is a schematic diagram of 5 printed lines during normal printing, and Figure (b) is a schematic diagram of printed lines after the 3rd and 4th printed lines are filled and overlapped and are still printed according to the original line width. The dotted line portion is the outline of the last printed line during normal printing. It can be seen from Figure (b) that when printed lines overlap, gaps will appear in the area that should have been filled with lines, and due to the uncertainty of the overlapping width, the gap width is also uncertain, which easily leads to the remaining width being less than the minimum line width value that the current printing device can print, thereby affecting the printing effect and printing quality. Figure (c) is a schematic diagram of lines printed according to the 3D printing method provided in this embodiment. The shaded portion in the figure is the printed line after the printed line width is adjusted. By calculating and changing the printed line width, the printing effect and printing quality are effectively guaranteed.

[0090] Reference Manual Attached Figure 7 , shows a schematic diagram of printed lines when a printing gap appears, wherein Figure (a) is a schematic diagram of 5 printed lines during normal printing, Figure (b) is a schematic diagram of printed lines after printing according to the original line width when a gap appears between the 2nd and 3rd printed lines, and Figure (c) is a schematic diagram of lines printed according to the 3D printing method provided in this embodiment. The shaded part in the figure is the printed line that fills the gap after the line width is modified. By calculating and changing the printed line width, the gap that appears during printing is effectively filled to ensure the printing effect and printing quality.

[0091] Embodiment 5:

[0092] Reference Manual Attached Figure 8 , showing a 3D printing method provided by an embodiment of the present invention, using any of the above-mentioned constant power density zoom spot systems, comprising the following steps:

[0093] Step 4.1: Calculate the width of each printed line according to the printing task;

[0094] Step 4.2: According to the width of the i-th printing line, adjust the widths of the first slit and the second slit so that the size of the light spot emitted by the focusing lens meets the width requirement of the i-th printing line, where i=1, 2, 3, 4...j, and j represents the total number of reprinted lines in the current printing task;

[0095] Step 4.3: The laser light source emits a laser beam, which passes through the collimator, the first reflector, the double slit device, the second reflector, the third reflector and the focusing lens in sequence and is directed toward the printing work surface to generate the i-th printing line.

[0096] Therefore, different printing accuracy requirements for the same printing task are distinguished, and the line width is calculated according to different printing requirements to avoid the situation where the overall accuracy does not meet the printing requirements or the efficiency is low due to the use of the same line width under different accuracy requirements, thereby ensuring the printing quality and improving the printing efficiency. The size of the light spot can be adjusted through the double slit device to ensure that the energy density does not change when the line width changes, thereby improving the printing quality and efficiency.

[0097] In an optional embodiment, when i+1≤j, the width of the i-th printing line and the width of the i+1-th printing line are obtained in real time and compared to determine whether the width of the i-th printing line is consistent with the width of the i+1-th printing line. If they are consistent, after the i-th printing line is completed, there is no need to adjust the first slit and the second slit. If they are inconsistent, after the current printing line is completed, the first slit and the second slit are adjusted according to the width of the i+1-th printing line. Thus, the current printing line width is compared with the next printing line width, and when the next printing line needs to change the line width, the line width is adjusted in time.

[0098] Embodiment 6:

[0099] An embodiment of the present invention provides a 3D printing method, using any of the above-mentioned systems of constant power density variable focal spot, comprising the following steps:

[0100] Step 4.1: Calculate the width of each printed line according to the printing task;

[0101] Step 4.2: According to the width of the i-th printing line, adjust the widths of the first slit and the second slit so that the size of the light spot emitted by the focusing lens meets the width requirement of the i-th printing line, where i=1, 2, 3, 4...j, and j represents the total number of reprinted lines in the current printing task;

[0102] Step 4.3: The laser light source emits a laser beam, which passes through the collimator, the first reflector, the double slit device, the second reflector, the third reflector and the focusing lens in sequence and is directed toward the printing work surface to generate the i-th printing line.

[0103] Among them, refer to the attached manual Fig. 9 , shows a specific method for calculating the width of each printed line according to the printing task in step 4.1, which may include the following steps:

[0104] Step 5.1: Get the accuracy requirement of the current printing task.

[0105] Step 5.2: Determine whether there is more than one precision requirement in the current printing task. If so, divide the printing task into several tasks according to different precision requirements and then execute step 5.3. If not, directly execute step 5.3.

[0106] Step 5.3: For a print task or print subtask that has only one print precision requirement, determine the line width of the print line according to the print precision requirement;

[0107] Step 5.4: Determine the print margin according to the line width of the print line and the size of the print task or print subtask, and determine whether the print margin is equal to 0. If the print margin is equal to 0, the print line width calculation is completed.

[0108] If the print margin is greater than 0 and less than the print line width, go to step 5.5;

[0109] Step 5.5: Get the minimum line width value that the current printing device can print, and determine whether the print margin is less than the minimum line width value. If the print margin is not less than the minimum line width value, then record the print margin as the line width of the last printed line;

[0110] If the print margin is less than the minimum line width value, go to step 5.6;

[0111] Step 5.6: Split the print margin into N, where N is an integer. Suppose the number of print lines after removing the print margin in the print task and print subtask is M, then N≤M. Add the N increments to the N print line widths respectively, and record the widths of the new N print lines.

[0112] In an optional embodiment, the selection of which print line widths to add to the split and increment of the print margin should be carried out on the premise of ensuring printing efficiency and printing quality, and on the principle of being able to achieve the current printing device and adjusting the line width the least number of times. Thus, on the premise of ensuring printing quality, by adjusting the line width as little as possible, the equipment adjustment time is saved and the printing efficiency is improved.

[0113] The 3D printing method provided in this embodiment has the following beneficial effects:

[0114] (1) By setting up a double slit device and a rotating device, the width and angle of the double slits can be adjusted, thereby adjusting the size of the light spot and then adjusting the printing line width. During the adjustment process, the energy density is not changed, only the size of the light spot is changed, which meets the processing requirements of variable line width without affecting the printing effect, improves printing efficiency, and ensures printing quality;

[0115] (2) Different printing accuracy requirements for the same printing task are distinguished, and line widths are calculated according to different printing requirements, so as to avoid the situation where the overall accuracy does not meet the printing requirements or the efficiency is low due to the use of the same line width under different accuracy requirements, thereby ensuring the printing quality and improving the printing efficiency;

[0116] (3) Calculate and split the printing residue to avoid the current processing equipment being unable to process the printing residue and affecting the printing accuracy and printing effect, thereby further improving the printing quality.

[0117] Embodiment 7:

[0118] Reference Manual Attached Fig.10 , showing a 3D printing device provided by an embodiment of the present invention, applying any of the above-mentioned 3D printing methods, including:

[0119] A line width calculation module 61, used to calculate the width of each printed line according to the printing task;

[0120] The constant power density zoom spot system 62 may be any of the constant power density zoom spot systems provided in the aforementioned embodiments 1-2, wherein a laser light source, a collimator, a first reflector, a double slit device, a second reflector, a third reflector and a focusing lens are sequentially arranged along the optical path direction, the double slit device comprises a first slit and a second slit, the widths of the first slit and the second slit are adjustable, the laser light source emits a laser beam, and the laser beam sequentially passes through the collimator, the first reflector, the double slit device, the second reflector, the third reflector and the focusing lens to be emitted to the printing working surface to generate printing lines;

[0121] The double slit device control module 63 is used to adjust the widths of the first slit and the second slit according to the width of the printed line, so that the size of the output light spot of the focusing lens meets the width requirement of the current printed line.

[0122] The embodiments described above are merely illustrative, wherein the units or modules described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, and may be located in one place or distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment. Those of ordinary skill in the art may understand and implement it without creative effort.

[0123] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, or of course by hardware. Based on this understanding, the above technical solution, in essence or in other words, the part that contributes to the prior art, can be expressed in the form of a software product, which can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which may be a personal computer, a server or a network device, etc.) to execute the methods of each embodiment or some parts of the embodiment.

[0124] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not make the corresponding technical solutions essentially deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A system with a constant power density variable focal spot, characterized in that: include: A laser light source, a collimating mirror, a first reflecting mirror, a double slit device, a second reflecting mirror, a third reflecting mirror and a focusing lens are sequentially arranged along the optical path direction; Among them, the double slit device includes a first slit, a second slit and a slit rotating stage. The first slit and the second slit are vertically arranged, the width of the first slit and the second slit is adjustable, the first slit and the second slit are used together to adjust the size of the light spot, and the slit rotating stage is used to adjust the angle of the first slit and the second slit so that the direction of the first slit and the second slit adapts to the scanning angle.

2. The system of constant power density variable focal spot according to claim 1, characterized in that: It also includes a rotating device, which is used to drive the first slit, the second slit and the slit rotating platform to rotate.

3. The system of constant power density variable focal spot according to claim 1, characterized in that: The double slit device comprises a first light barrier, a second light barrier, a third light barrier and a fourth light barrier. The opposite sides of the first light barrier sheet and the second light barrier sheet are parallel to each other, forming a first slit; The opposite sides of the third light barrier sheet and the fourth light barrier sheet are parallel to each other, forming a second slit.

4. The system of constant power density variable focal spot according to claim 3, characterized in that: The rotating device is connected to the first light bar, the second light bar, the third light bar and the fourth light bar respectively, and is used to drive the first light bar, the second light bar, the third light bar and the fourth light bar to rotate with the center of the intersection area of ​​the first slit and the second slit as the rotation center point.

5. A method for constant power density variable focal spot, using the constant power density variable focal spot system according to any one of claims 1 to 4, characterized in that: The following steps are involved: Obtaining the size of the light spot required for the current printing action, adjusting the widths of the first slit and the second slit so that the intersection area of ​​the first slit and the second slit meets the size requirement of the light spot, and adjusting the angle of the first slit and the second slit so that the directions of the first slit and the second slit adapt to the scanning angle; The laser light source is controlled to emit a laser beam, which passes through a collimating mirror, a first reflecting mirror, a double slit device, a second reflecting mirror, a third reflecting mirror and a focusing lens in sequence and is emitted to a printing working surface.

6. The method for constant power density variable focus spot according to claim 5, characterized in that: After obtaining the size of the light spot required for the current printing action, the width and angle of the first slit and the second slit are adjusted so that the intersection area of ​​the first slit and the second slit meets the size requirement of the light spot and the angle of the first slit and the second slit meets the requirement of the scanning angle.

Images