Method for stitching calibration of optical unit for 3D printer

Abstract

The present invention discloses a method for calibrating the splicing of optical units of a 3D printer. The method comprises: the 3D printer comprises at least two optical units, wherein the at least two optical units comprise a first optical unit and a second optical unit adjacent thereto; the method comprises: controlling the first optical unit to project light onto a first area to form a first feature, and controlling the second optical unit to project light onto a second area to form a second feature; acquiring an image of a splicing area, wherein the splicing area comprises at least a portion of the first area and at least a portion of the second area, and the splicing area comprises the first feature and the second feature; determining the positional relationship between the first feature and the second feature, and determining whether optical unit splicing calibration is required based on the positional relationship. The present invention solves the technical problem in the related art of using calibration tools to calibrate optical unit splicing, resulting in low calibration efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of 3D printing, and in particular to a method for splicing and calibrating an optical unit of a 3D printer. Background Art

[0002] Current 3D printing technologies include laser stereolithography (SLA), digital light processing (DLP), liquid crystal display technology (LCD), fused deposition modeling (FDM), and selective laser sintering (SLS).

[0003] Because digital light processing (DLP) is difficult to achieve a balance between precision and printing format, optical-mechanical splicing (i.e., using at least two optical machines or projection devices to simultaneously project different parts of the target image, ultimately producing a combined projected image) can be used to expand the printing format without sacrificing precision. However, due to the physical structure of the optical-mechanical components being subject to slight deformation over time or temperature, or slight shifts in the physical position of the optical machines, the precision of the spliced ​​area can deteriorate.

[0004] To address the above-mentioned problems, no effective solutions have been proposed so far. Summary of the Invention

[0005] An embodiment of the present invention provides a method for calibrating the splicing of optical units of a 3D printer, so as to at least solve the technical problem in the related art of using calibration tools to calibrate the splicing of optical units, resulting in low calibration efficiency.

[0006] According to one aspect of an embodiment of the present invention, a method for stitching and calibrating optical units of a 3D printer is provided. The 3D printer includes at least two optical units, wherein the at least two optical units include a first optical unit and a second optical unit adjacent thereto. The method includes: controlling the first optical unit to project light onto a first area to form a first feature, and controlling the second optical unit to project light onto a second area to form a second feature; acquiring an image of a stitching area, wherein the stitching area includes at least a portion of the first area and at least a portion of the second area, and the stitching area includes the first feature and the second feature; determining a positional relationship between the first feature and the second feature; and calibrating the first optical unit and / or the second optical unit based on the positional relationship.

[0007] In some embodiments, determining the positional relationship between the first feature and the second feature, and judging whether optical unit stitching calibration is required based on the positional relationship includes: respectively calculating the distance values ​​of the first feature and the second feature in the horizontal direction and the vertical direction; comparing the distance value in the horizontal direction with a preset horizontal distance threshold, and comparing the distance value in the vertical direction with a preset vertical distance threshold; when the distance value in the horizontal direction is less than or equal to the preset horizontal distance threshold, and the distance value in the vertical direction is less than or equal to the preset vertical distance threshold, judging that optical unit stitching calibration is not required.

[0008] In some embodiments, when the distance value in the horizontal direction is greater than a preset horizontal distance threshold, the first optical unit and / or the second optical unit are calibrated; and / or when the distance value in the vertical direction is greater than a preset vertical distance threshold, the first optical unit and / or the second optical unit are calibrated.

[0009] In some embodiments, the first feature includes one or more feature points, and the second feature includes one or more feature points, wherein the positional relationship is determined by the center of the one or more feature points of the first feature and the center of the one or more feature points of the second feature.

[0010] In some embodiments, the positional relationship includes an angular deviation between the first feature and the second feature, where the angular deviation is determined by a plurality of feature points / groups of the first feature arranged along a predetermined direction and a plurality of feature points / groups of the second feature arranged along a predetermined direction. The predetermined direction is, for example, a vertical direction or a horizontal direction, depending on the positional relationship between the first optical unit and the second optical unit, such as vertically adjacent or horizontally adjacent.

[0011] In some embodiments, the method further comprises calibrating the first optical unit and / or the second optical unit based on the positional relationship. Calibrating the optical units comprises performing translation and rotation compensation on the corresponding images. The physical structure of the optical units may also be moved if necessary.

[0012] In some embodiments, the first feature includes multiple first feature groups, and the second feature includes multiple second feature groups, wherein the multiple first feature groups correspond one-to-one to the multiple second feature groups, the first feature group includes one or more feature points, and the second feature group includes one or more feature points, determining the positional relationship between the first feature and the second feature, and judging whether optical unit stitching calibration is required based on the positional relationship, including: respectively calculating the distance values ​​of the central feature points in the multiple first feature groups and the corresponding central feature points in the second feature groups in the horizontal direction and the vertical direction to obtain multiple horizontal distance values ​​and multiple vertical distance values; respectively calculating the average values ​​of the multiple horizontal distance values ​​and the multiple vertical distance values ​​to obtain the horizontal distance average value and the vertical distance average value; comparing the horizontal distance average value with a preset horizontal distance threshold, and comparing the vertical distance average value with a preset vertical distance threshold; when the horizontal distance average value is less than or equal to the preset horizontal distance threshold, and the vertical distance average value is less than or equal to the preset vertical distance threshold, judging that optical unit stitching calibration is not required.

[0013] In some embodiments, the method further includes: calibrating the first optical unit and / or the second optical unit when the average horizontal distance is greater than a preset horizontal distance threshold; and / or calibrating the first optical unit and / or the second optical unit when the average vertical distance is greater than a preset vertical distance threshold.

[0014] In certain embodiments, a 3D printer includes at least two optical units, wherein the at least two optical units include a first optical unit and a second optical unit adjacent thereto, and the method includes: controlling the first optical unit to project light onto a first area to form a first feature, and controlling the second optical unit to project light onto a second area to form a second feature; acquiring an image of a stitching area, wherein the stitching area includes at least a portion of the first area and at least a portion of the second area, and the stitching area includes the first feature and the second feature; determining a positional relationship between the first feature and the second feature, and determining whether optical unit stitching calibration is required based on the positional relationship.

[0015] In some embodiments, an image of the stitching area is acquired by an image acquisition device, wherein a preset distance condition is met between a lens of the image acquisition device and the material tray to reduce optical distortion, wherein the material tray includes a first area and a second area.

[0016] In certain embodiments, the image acquisition device is a handheld microscope that is in direct contact with the tray.

[0017] In some embodiments, the first optical unit and the second optical unit project light simultaneously or sequentially.

[0018] According to another aspect of an embodiment of the present invention, a device for optical unit stitching calibration of a 3D printer is also provided. The 3D printer includes at least two optical units, wherein the at least two optical units include a first optical unit and a second optical unit adjacent thereto. The device includes: a control module, configured to control the first optical unit to project light onto a first area to form a first feature, and to control the second optical unit to project light onto a second area to form a second feature; an acquisition module, configured to acquire an image of a stitching area, wherein the stitching area includes at least a portion of the first area and at least a portion of the second area, and the stitching area includes the first feature and the second feature; and a determination module, configured to determine a positional relationship between the first feature and the second feature, and to determine whether optical unit stitching calibration is required based on the positional relationship.

[0019] In certain embodiments, the first optical unit and the second optical unit are the same type of optical unit, and wherein the optical unit is selected from any one of the following: DLP, LCD, OLED, LCOS, Micro-LED, Mini-LED.

[0020] According to another aspect of an embodiment of the present invention, a non-volatile storage medium is provided, which includes a stored program, wherein when the program is running, the device where the non-volatile storage medium is located is controlled to execute any one of the above-mentioned methods for stitching calibration of the optical unit of a 3D printer.

[0021] According to another aspect of an embodiment of the present invention, a computer device is provided, comprising a processor configured to run a program, wherein the program executes any one of the aforementioned methods for stitching calibration of an optical unit of a 3D printer when the program is run.

[0022] According to yet another aspect of an embodiment of the present invention, a computer program product is provided, including a computer program. When the computer program is executed by a processor, it implements any one of the above methods for stitching calibration of an optical unit of a 3D printer.

[0023] In an embodiment of the present invention, a method for stitching and calibrating optical units of a 3D printer is adopted, by controlling the first optical unit to project light to a first area to form a first feature, and controlling the second optical unit to project light to a second area to form a second feature; obtaining an image of the stitching area, wherein the stitching area includes at least a portion of the first area and at least a portion of the second area, and the stitching area includes the first feature and the second feature; determining the positional relationship between the first feature and the second feature, and judging whether optical unit stitching calibration is required based on the positional relationship, thereby achieving the purpose of calibration without relying on calibration tools, thereby realizing the technical effect of improving the calibration efficiency of optical unit stitching, and further solving the technical problem in the related art of using calibration tools to perform calibration of optical unit stitching, resulting in low calibration efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0025] Figure 1 A hardware structure block diagram of a computer terminal for implementing a method for optical-mechanical stitching calibration of a 3D printer is shown;

[0026] Figure 2 3D printer calibration method according to an embodiment of the present invention;

[0027] Figure 3 2. It is a schematic diagram of an optical-mechanical projection image in a method for optical-mechanical stitching calibration of a 3D printer provided in accordance with an optional embodiment of the present invention;

[0028] Figure 4 2 is a schematic diagram of a positioning frame in a method for optical-mechanical stitching calibration of a 3D printer provided according to an optional embodiment of the present invention;

[0029] Figure 5 is a schematic diagram of an image of a stitching area in a method for optical-mechanical stitching calibration of a 3D printer provided in an optional embodiment of the present invention;

[0030] Figure 6 is an example diagram of deviation in a method for optical-mechanical stitching calibration of a 3D printer provided according to an optional embodiment of the present invention;

[0031] Figure 7 This is an optional flowchart of a method for optical-mechanical stitching calibration of a 3D printer provided according to an optional embodiment of the present invention;

[0032] Figure 8 4 is a structural block diagram of an apparatus for optical-mechanical stitching calibration of a 3D printer provided according to an embodiment of the present invention. DETAILED DESCRIPTION

[0033] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all solutions obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0034] It should be noted that the terms "first," "second," and the like in the description and claims of the present invention are used to distinguish similar objects and are not necessarily used to describe a specific order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate. In addition, the terms "including," "having," and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus comprising 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 that are inherent to these processes, methods, products, or apparatuses.

[0035] According to embodiments of the present invention, various embodiments of methods for optical-mechanical stitching calibration of 3D printers are provided. It should be noted that the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowcharts, in some cases, the steps shown or described can be executed in a different order.

[0036] The method embodiments provided in the embodiments of the present application can be executed in a mobile terminal, a computer terminal or a similar computing device. Figure 1 The hardware structure block diagram of a computer terminal for implementing a method for optical-mechanical stitching calibration of a 3D printer is shown. Figure 1 As shown, the computer terminal 10 may include one or more (illustrated as 102a, 102b, ..., 102n in the figure) processors (processors include but are not limited to processing devices such as microprocessors (MCUs) or programmable logic devices (FPGAs)), and a memory 104 for storing data. In addition, it may also include: a display, an input / output interface (I / O interface), a universal serial bus (USB) port (which may be included as one of the ports of the BUS bus), a network interface, a power supply, and / or a camera. It will be understood by those skilled in the art that Figure 1 The structure shown is only for illustration and does not limit the structure of the above electronic device. Figure 1 More or fewer components than shown, or with Figure 1 Different configurations shown.

[0037] It should be noted that the one or more processors and / or other data processing circuits described above may generally be referred to herein as "data processing circuitry." The data processing circuitry may be embodied in whole or in part as software, hardware, firmware, or any other combination thereof. Furthermore, the data processing circuitry may be a single, independent processing module, or may be incorporated in whole or in part into other components of the computer terminal 10. As described in the embodiments of the present application, the data processing circuitry is controlled as a processor (e.g., the selection of a variable resistor terminal path connected to an interface).

[0038] The memory 104 can be used to store software programs and modules for application software, such as the program instructions / data storage device corresponding to the method for optical-mechanical stitching calibration of a 3D printer in an embodiment of the present invention. The processor executes the software programs and modules stored in the memory 104 to perform various functional applications and data processing, thereby implementing the method for optical-mechanical stitching calibration of a 3D printer in the aforementioned application. The memory 104 can include random access memory, such as a high-speed random access memory, and can also include non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some examples, the memory 104 can further include memory remotely located relative to the processor, and these remote memories can be connected to the computer terminal 10 via a network. Examples of such networks include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0039] The display may be, for example, a touch screen liquid crystal display (LCD) that enables a user to interact with a user interface of the computer terminal 10 .

[0040] Currently, in digital light processing (DLP) 3D printing, to expand the printing format without sacrificing printing accuracy, optical-mechanical splicing can be used. This involves simultaneously using at least two optical machines (projectors) or projection devices to project different parts of the target image, ultimately producing a combined projected image. However, the optical machine (as a physical structure) can undergo slight deformation over time or temperature changes, or its physical position can shift slightly, resulting in reduced precision in the spliced ​​area.

[0041] A 3D printer may include multiple optical machines, such as two, three, four, or five. The multiple optical machines are combined to project a target image. In some embodiments, the multiple optical machines are arranged in an array.

[0042] In this article, the optical engine can be replaced with other components used for light curing. For example, the optical engine or DLP (Digital Light Processing) component can be replaced with an LCD (Liquid Crystal Display) component, an OLED (Organic Light-Emitting Diode) component, an LCOS (Liquid Crystal on Silicon) component, a Micro-LED component, a Mini-LED component, or a liquid crystal projection component. For splicing multiple optical units in a 3D printer, optical units of the same type can be used. For example, four LCD components or six Micro-LED components can be spliced ​​together.

[0043] Figure 2 FIG. 1 is a flow chart of a method for optical-mechanical stitching calibration of a 3D printer according to an embodiment of the present invention. Figure 2 As shown, the method includes the following steps: a 3D printer includes a plurality of spliced ​​optical machines, wherein any two adjacent optical machines in the plurality of spliced ​​optical machines can be regarded as a first optical machine and a second optical machine,

[0044] In step S202 , the first optical machine is controlled to project light onto the first area to form a first feature, and the second optical machine is controlled to project light onto the second area to form a second feature.

[0045] In this step, the 3D printer may include multiple optical machines spliced ​​together, and any two adjacent optical machines can serve as the first optical machine and the second optical machine. The first optical machine can be controlled to project onto a first area (e.g., the release film of a 3D printer's material tray) to form a first feature, and the second optical machine can be controlled to project onto a second area (e.g., the release film of a 3D printer's material tray) to form a second feature. Both the first feature and the second feature will include feature points, which are helpful for subsequent calibration of the optical machine. In some embodiments, the first area and the second area can be the surface of the material tray, such as the surface of a release film.

[0046] Step S204 : acquiring an image of the stitched area, wherein the stitched area includes at least a portion of the first area and at least a portion of the second area, and the stitched area includes the first feature and the second feature.

[0047] In this step, the "stitching area" refers to the area within the build area associated with the edges of the projection formats of two adjacent optical engines. The image in the stitching area includes the image at the junction of the first and second images. If there is overlap between the first and second images, the stitching area also includes the overlap. Specifically, the image in the stitching area includes both the portion of the first image with the first feature point and the portion of the second image with the second feature point. Subsequent calibration procedures can be performed based on this stitched image. Figure 3: is a schematic diagram of an optical-mechanical projection image in a method for optical-mechanical stitching calibration of a 3D printer provided in an optional embodiment of the present invention, such as Figure 3 As shown, the left image is the image of the splicing area after the first optical machine (left optical machine) and the second optical machine (right optical machine) project light. Figure 3 The figure shows three groups of feature points, which are located in three areas A1, A2, and A3 respectively. The figure on the right shows the feature image when a group of feature points projected by the first optical machine and the second optical machine overlap. Figure 3 In the example shown, the first feature and the second feature each include three groups of features, and each group of features may include nine (3 rows and 3 columns) feature points.

[0048] Figure 4 Schematic diagram of an optical projection image in a method for optical-mechanical splicing calibration of a 3D printer provided in an optional embodiment of the present invention. Figure 4 As shown, the first optical engine can be controlled to project an image onto a first area, wherein the image includes at least one positioning circle 430. The positioning circle 430 can facilitate the capture of subsequent images. Optionally, the positioning circle 430 can include positioning markers, such as a positioning frame 420 and / or a positioning point 420 (the feature point 410 can serve as the positioning point). The positioning frame is a positioning marker that at least partially surrounds the feature point. The positioning frame can be used to preliminarily and quickly locate the area containing the feature point to facilitate the capture of subsequent images. The positioning point is also a positioning marker that can be used separately. The first and second optical engines can project light simultaneously or sequentially, for example, the first optical engine projects light and then the second optical engine projects light. If the feature point is large (or the pixel size of the feature point in the captured image is large), sequential projection of light may be advantageous because the coordinates of the feature point (especially the center) in the image obtained by sequential projection are easier to identify and calculate the center coordinates. However, in the image obtained by simultaneous projection, the feature points from the two optical engines may overlap, which is not conducive to obtaining the coordinates of the feature point.

[0049] Step S206 , determining the positional relationship between the first feature and the second feature, and determining whether optical-mechanical stitching calibration is required based on the positional relationship.

[0050] In this step, the first and second optical engines can be calibrated based on the positional relationship between the first and second feature points. For example, if the positional deviation between the first and second feature points is within a certain threshold, the first and second optical engines are considered to be accurately spliced ​​and no calibration is required. If the positional deviation between the first and second feature points exceeds the threshold, calibration can be performed, for example, by modifying the calibration files of the first and second optical engines.

[0051] Through the above steps, the purpose of calibration without relying on calibration tools is achieved, thereby realizing the technical effect of improving the calibration efficiency of optical-mechanical splicing, and further solving the technical problem of low calibration efficiency caused by using calibration tools to calibrate optical unit splicing in related technologies.

[0052] As an optional embodiment, determining the positional relationship between the first feature and the second feature, and judging whether optical-mechanical stitching calibration is required based on the positional relationship includes: respectively calculating the distance values ​​of the first feature and the second feature in the horizontal direction and the vertical direction; comparing the distance value in the horizontal direction with a preset horizontal distance threshold, and comparing the distance value in the vertical direction with a preset vertical distance threshold; when the distance value in the horizontal direction is less than or equal to the preset horizontal distance threshold, and the distance value in the vertical direction is less than or equal to the preset vertical distance threshold, judging that optical-mechanical stitching calibration is not required.

[0053] As an optional embodiment, when the horizontal distance value is greater than a preset horizontal distance threshold, the first optical machine and / or the second optical machine is calibrated; and / or, when the vertical distance value is greater than a preset vertical distance threshold, the first optical machine and / or the second optical machine is calibrated.

[0054] Optionally, when one of the horizontal distance values ​​and the vertical distance value does not meet the preset requirements, it is necessary to calibrate the first optical engine or the second optical engine, or both optical engines can be calibrated. Calibration can be performed based on the distance value that does not meet the requirements. For example, if the horizontal distance value does not meet the preset requirements, the parameters related to the horizontal projection in the calibration file of the first optical engine and / or the second optical engine should be adjusted. Similarly, if the vertical distance value does not meet the preset requirements, the parameters related to the vertical projection in the calibration file of the first optical engine and / or the second optical engine can be adjusted.

[0055] For example, the first optical machine and the second optical machine can be calibrated according to the positional relationship between the first feature point and the second feature point, and a rectangular coordinate system can be established in the stitching area. The first coordinate (CLx, CLy) corresponding to the first feature point and the second coordinate (CRx, CRy) corresponding to the second feature point are determined in the rectangular coordinate system. The first optical machine and the second optical machine can be calibrated according to the first coordinate and the second coordinate. Specifically, the deviation dx in the horizontal direction, i.e., the x-direction, can be determined, where dx=CRx-CLx, and the deviation dy in the vertical direction, i.e., the y-direction, can be determined, where dy=CRy-CLy. According to the values ​​of dx and dy, it is determined whether they are within the preset deviation range, that is, whether the distance values ​​of the first feature point and the second feature point in the horizontal and vertical directions meet the preset requirements.

[0056] As an optional embodiment, the first feature includes one or more feature points, and the second feature includes one or more feature points, wherein the positional relationship is determined by the center of the one or more feature points of the first feature and the center of the one or more feature points of the second feature.

[0057] In the case where both the first feature and the second feature include multiple feature points, the coordinates of the center position can be calculated based on the coordinates corresponding to the multiple feature points, thereby determining the positional relationship between the first feature and the second feature.

[0058] Multiple first feature points in the first image and multiple second feature points in the second image in the stitched area can be obtained. The center positions of the multiple first feature points can be used as a single feature point, and the center positions of the multiple second feature points can be used as a second feature point. First coordinates corresponding to the first feature points can be determined based on the coordinates corresponding to the multiple first feature points, and second coordinates corresponding to the second feature points can be determined based on the coordinates corresponding to the multiple second feature points. Figure 5 : is a schematic diagram of an image of a stitching area in a method for optical-mechanical stitching calibration of a 3D printer provided in an optional embodiment of the present invention, such as Figure 5 As shown, the left part is the projection diagram of the first optical machine in the stitching area, and the right part is the projection diagram of the second optical machine in the stitching area, wherein the image formed by the optical machine projection may include multiple light spots, and the center of each light spot is used as a feature point. Because the deviation change after the single optical machine calibration (each optical machine will be calibrated separately) is generally small, it can be considered that the spacing between the light spots in each row and column in the single optical machine projection is the same as the design value (Ld) (that is, the preset center spacing between any two adjacent light spots is Ld, in mm). Take adjacent light spots in different rows or columns and calculate the pixel distance Lp, as shown Figure 5 The center coordinates of each spot are Lnx and Lny (n=1, 2, 3…8, 9, representing the sequence of different spots), where the pixel distance between spots L1 and L2 is The average of multiple pixel distances (each pixel distance comes from two adjacent light spots) can be calculated to obtain a more accurate average pixel distance Lp (in px). Single pixel size L = Ld / Lp (mm / px), which represents the actual size of each pixel. Then, the coordinates of the corresponding feature points are obtained based on multiple feature points. For example, Figure 5 In the example, the coordinates of the feature points of the first optical machine are Lnx and Lny (n=1, 2, 3…8, 9), and the center positions of multiple feature points in the first optical machine can be obtained, that is, the first coordinates corresponding to the center coordinates of the first feature are (CLx, CLy), where:

[0059] Similarly, the coordinates of the feature points in the second optical machine are Rnx and Rny (n=1, 2, 3...8, 9), and the center positions of multiple feature points in the second optical machine can be obtained, that is, the second coordinates corresponding to the second feature point are (CRx, CRy), where, Based on the first coordinate of the center of the first feature and the second coordinate of the center of the second feature, the horizontal and vertical deviations can be calculated. That is, the deviations in the x and y directions are dx = (CRx - CLx) * L and dy = (CRy - CLy) * L, respectively. The x and y deviations are then used to determine whether calibration of the first and / or second optical engines is necessary.

[0060] As an optional embodiment, the positional relationship includes an angular deviation between the first feature and the second feature, and the angular deviation is determined by a plurality of feature points of the first feature arranged along the vertical direction and a plurality of feature points of the second feature arranged along the vertical direction.

[0061] As an optional embodiment, the first feature includes multiple first feature groups, and the second feature includes multiple second feature groups, wherein the multiple first feature groups correspond one-to-one to the multiple second feature groups, the first feature group includes one or more feature points, and the second feature group includes one or more feature points, the positional relationship between the first feature and the second feature is determined, and whether optical-mechanical stitching calibration is required is judged based on the positional relationship, including: respectively calculating the distance values ​​in the horizontal and vertical directions between the central feature points in the multiple first feature groups and the corresponding central feature points in the second feature groups to obtain multiple horizontal distance values ​​and multiple vertical distance values; respectively calculating the average values ​​of the multiple horizontal distance values ​​and the multiple vertical distance values ​​to obtain the horizontal distance average value and the vertical distance average value; comparing the horizontal distance average value with a preset horizontal distance threshold, and comparing the vertical distance average value with a preset vertical distance threshold; when the horizontal distance average value is less than or equal to the preset horizontal distance threshold, and the vertical distance average value is less than or equal to the preset vertical distance threshold, it is judged that optical-mechanical stitching calibration is not required.

[0062] It also includes: calibrating the first optical engine and / or the second optical engine when the average horizontal distance is greater than a preset horizontal distance threshold; and / or calibrating the first optical engine and / or the second optical engine when the average vertical distance is greater than a preset vertical distance threshold.

[0063] The first feature and the second feature can both include multiple sets of features, and each set of features can include multiple feature points. Figure 3The stitching area shown includes three areas, each of which corresponds to a set of features. At this time, it can be determined whether the optical machine needs to be calibrated based on the positional relationship between the center position of the corresponding first feature group and the center position of the second feature group. The distance values ​​in the horizontal and vertical directions between the center feature point in each first feature group and the center feature point in the corresponding second feature group can be obtained, and then the average value of the distance values ​​in the horizontal and vertical directions corresponding to each group of feature points can be calculated to calibrate the first and second optical machines. Specifically, the deviations in the x-direction and y-direction corresponding to the i-th group of feature groups are dix and diy respectively. Based on the deviations in the x-direction and y-direction corresponding to the i-th group of feature groups, the average value of the deviation in the x-direction can be calculated as Dx, and the average value of the deviation in the y-direction can be calculated as Dy, where Dx = (d1x + d2x + ... dkx) / k, and Dy = (d1y + d2y + ... dky) / k. Figure 6 : is an example diagram of deviation in the method for optical-mechanical stitching calibration of a 3D printer provided in an optional embodiment of the present invention, such as Figure 6 As shown, the angle deviation value can also be calculated, Dθ = arctan ((d1x-dix) / T), where T is the difference between the feature point in the first group of feature points and the feature point in the i-th group ( Figure 5 The example (i=3) shows the distance value of the feature point in the y direction. According to the deviation values ​​in the x and y directions and the angle deviation values, the first optical machine and the second optical machine can be calibrated. For example, the threshold values ​​of the average spacing deviations Dx and Dy are 0.05mm to 1.00mm, such as 0.5mm, 0.25mm, 0.15mm, 0.085mm, 0.055mm, etc.; the threshold value of the total average angle deviation θ is 0.5° to 3°, such as 2°, 1°, 0.8°. If the threshold value is exceeded, calibration is performed according to the deviation amount, and the calibration files of the first optical machine and the second optical machine are modified (for example, reverse compensation is performed), and the above steps are repeated to obtain the feature points and then calculate the deviation until it is adjusted to within the qualified range.

[0064] Before using the optical engine, the single optical engine can be calibrated to at least keep the optical distortion (barrel distortion or pincushion distortion) introduced by the optical engine within an acceptable range. If the optical distortion introduced by the optical engine is not eliminated, the effect of this optical distortion can be mitigated, for example, by determining the center coordinates of multiple feature points.

[0065] When using an image acquisition tool to capture feature point images, the tool may introduce optical distortion. Due to the physical limitations of the printing device, feature points are typically located on a release film. To avoid optical distortion, the distance between the tool's lens and the feature points on the release film must be appropriate. In some scenarios, the tool is placed directly on the release film to capture feature point images.

[0066] Optionally, the first and second optical engines can be calibrated based on the amount of expansion and contraction of the first and second feature points, where the expansion and contraction refers to the degree of deformation of the feature points. Because the captured image may be distorted due to distortion, the expansion and contraction amounts corresponding to the first and second feature points can be used to determine whether optical calibration is necessary to overcome optical distortion, thereby facilitating subsequent calibration of the first and second optical engines.

[0067] As an optional embodiment, the image of the stitching area is obtained by using a lens of a handheld microscope.

[0068] Alternatively, a handheld microscope can be used to capture an image of the joined area of ​​the first and second areas. This allows for more convenient and rapid acquisition of images of the joined area. Specifically, a handheld microscope with a camera function can be used for image capture. The handheld microscope can be placed directly on the release film (or other object containing feature points), which helps reduce the effects of optical distortion caused by the handheld microscope itself.

[0069] As an optional embodiment, a preset distance condition is satisfied between the lens and the tray, wherein the tray includes a first area and a second area.

[0070] The first and second areas of the first and second optical engines can be on the surface of the tray, so the lens of the acquisition area needs to maintain a suitable distance from the tray. Too close or too far will affect the final calibration effect.

[0071] It should be noted that for the aforementioned method embodiments, for simplicity of description, they are all expressed as a series of action combinations. However, those skilled in the art should be aware that the present invention is not limited by the order of the actions described, because according to the present invention, certain steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in this specification are all preferred embodiments, and the actions and modules involved are not necessarily required by the present invention.

[0072] Through the description of the above embodiments, those skilled in the art can clearly understand that the method for optical-mechanical stitching calibration of a 3D printer according to the above embodiment can be implemented by means of software plus a necessary general-purpose hardware platform. Of course, it can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product. The computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk), and includes a number of instructions for enabling a terminal device (which can be a mobile phone, computer, server, or network device, etc.) to execute the methods described in the various embodiments of the present invention.

[0073] Figure 7 FIG. 1 is an optional flow chart of a method for optical-mechanical stitching calibration of a 3D printer provided according to an optional embodiment of the present invention. Figure 7 A specific implementation is shown below:

[0074] T701: Optical projection: The optical projection is performed on the surface of the tray to present a positioning circle image (the image includes at least one positioning circle, such as two or three from top to bottom), each positioning circle represents a feature point area;

[0075] T702: Lens alignment: Place the microscope on the tray and press it with your hands or other devices to keep it still so that the microscope can capture the contents of the positioning circle (especially the photographic feature points);

[0076] T703: Photographing and recording: Two adjacent optical machines are used to project images of the feature points of the stitching area in turn, and photographed and recorded using a microscope. The stitching area must cover both ends and the middle of the stitching area.

[0077] T704: Coordinate extraction: The effect of the captured picture is as follows Figure 4 As shown, there are multiple equally spaced light spots in the picture (m rows and n columns, m ≥ 2, n ≥ 2). The center of each light spot image is identified to obtain the coordinates x and y of each light spot center, that is, the positioning point in the image;

[0078] T705: Calculate Deviation: Calculate the deviation of the splicing area based on the coordinate information. The calculation method is as follows:

[0079] 1. Calculation of single pixel size L: The preset center distance between any two adjacent light spots is Ld. Take adjacent light spots in different rows or columns and calculate the pixel distance Lp, such as Figure 4 , the center coordinates of each spot are Lnx and Lny (n=1, 2, 3…8, 9, representing the sequence of different spots), where the pixel distance Lp between spots L1 and L2 is Lnx= The average of the pixel distances between multiple light spots can be taken to obtain a more accurate pixel distance Lp (in px), and then the single pixel size L=Ld / Lp (mm / px) is obtained, where L represents the actual size of each pixel.

[0080] 2. Calculate the deviation: The coordinates of the positioning points of the first optical machine are Lnx and Lny (n = 1, 2, 3...8, 9). The center positions of multiple positioning points in the first optical machine can be obtained, that is, the first coordinates corresponding to the first feature point are (CLx, CLy), where CLx = (L1x+L2x+L3x+L4x+L5x+L6x+L7x+L8x+L9x) / 9, CLy = (L1y+L2y+L3y+L4y+L5y+L6y+L7y+L8y+L9y) / 9. Similarly, the coordinates of the positioning points in the second optical machine are Rnx and Rny (n=1, 2, 3…8, 9). The center positions of multiple positioning points in the second optical machine can be obtained, that is, the second coordinates corresponding to the second feature point are (CRx, CRy), wherein CRx=(R1x+R2x+R3x+R4x+R5x+R6x+R7x+R8x+R9x) / 9, CRy=(R1y+R2y+R3y+R4y+R5y+R6y+R7y+R8y+R9y) / 9.

[0081] 3. Calculation of xy deviation of each region: The x-direction and y-direction deviations corresponding to each feature point region are dx = (CRx-CLx)*L, dy = (CRy-CLy)*L respectively. The deviation of the i-th feature point region is recorded as dix and diy (i = 1, 2...k).

[0082] 4. Overall deviation calculation: The overall deviation is calculated using the deviations of the i-th area. The angular deviation Dθ = arctan((d1x-dix) / T) (T is the distance between the center of the first area and the center of the i-th area in the y direction), the x deviation Dx = (d1x+d2x+…dkx) / k, and the y deviation Dy = (d1y+d2y+…dky) / k.

[0083] T706: Optical and Mechanical Calibration: Determine whether the calculated deviations are within the specified range. For example, the threshold for the total average spacing deviations Dx and Dy is 0.5mm, preferably 0.25mm, 0.15mm, 0.085mm, or 0.055mm. For example, the threshold for the total average angle deviation θ is 1°, preferably 0.8°. If the deviations are outside the specified range, reverse calibration can be performed based on the deviations. Modify the calibration file and repeat the above steps, taking photos and calculating the deviations, until the deviations are within the specified range.

[0084] According to an embodiment of the present invention, there is also provided a device for optical-mechanical stitching calibration of a 3D printer for implementing the above-mentioned method for optical-mechanical stitching calibration of a 3D printer. Figure 8 is a structural block diagram of a device for optical-mechanical stitching calibration of a 3D printer provided according to an embodiment of the present invention, such as Figure 8 As shown, the device for optical-mechanical stitching calibration of a 3D printer includes: a control module 82, an acquisition module 84 and a calibration determination module 86. The device for optical-mechanical stitching calibration of a 3D printer is described below.

[0085] The 3D printer includes at least two optical machines, wherein the at least two optical machines include a first optical machine and a second optical machine adjacent thereto, and the device includes:

[0086] The control module 82 is used to control the first light engine to project light to the first area to form a first feature, and control the second light engine to project light to the second area to form a second feature.

[0087] The acquisition module 84 is connected to the control module 82 and is used to acquire an image of the stitching area, wherein the stitching area includes at least a portion of the first area and at least a portion of the second area, and the stitching area includes the first feature and the second feature.

[0088] The determination module 86 is connected to the acquisition module 84 and is used to determine the positional relationship between the first feature and the second feature, and determine whether optical-mechanical stitching calibration is required based on the positional relationship.

[0089] It should be noted that the control module 82, acquisition module 84, and calibration module 86 correspond to steps S202 to S206 in the embodiment. The examples and application scenarios implemented by the various modules and corresponding steps are the same, but are not limited to the contents disclosed in the above embodiment. It should be noted that the above modules, as part of the device, can be run in the computer terminal 10 provided in the embodiment.

[0090] An embodiment of the present invention may provide a computer device. Optionally, in this embodiment, the computer device may be located in at least one of a plurality of network devices in a computer network. The computer device includes a memory and a processor.

[0091] The memory can be used to store software programs and modules, such as the program instructions / modules corresponding to the method and apparatus for stitching and calibrating the optical unit of a 3D printer in the embodiments of the present invention. The processor executes the software programs and modules stored in the memory to perform various functional applications and data processing, thereby implementing the aforementioned method for stitching and calibrating the optical unit of a 3D printer. The memory can include high-speed random access memory and can also include non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory can further include memory remotely located relative to the processor, and these remote memories can be connected to the computer terminal via a network. Examples of the aforementioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0092] The processor can call the information and application stored in the memory through the transmission device to perform the following steps: control the first optical unit to project light to the first area to form a first feature, and control the second optical unit to project light to the second area to form a second feature; obtain an image of the stitching area, wherein the stitching area includes at least a portion of the first area and at least a portion of the second area, and the stitching area includes the first feature and the second feature; determine the positional relationship between the first feature and the second feature, and determine whether optical unit stitching calibration is required based on the positional relationship.

[0093] Optionally, the processor may also execute the program code of the following steps: determining the positional relationship between the first feature and the second feature, and judging whether optical unit stitching calibration is required based on the positional relationship, including: respectively calculating the distance values ​​of the first feature and the second feature in the horizontal and vertical directions; comparing the distance value in the horizontal direction with a preset horizontal distance threshold, and comparing the distance value in the vertical direction with a preset vertical distance threshold; when the distance value in the horizontal direction is less than or equal to the preset horizontal distance threshold, and the distance value in the vertical direction is less than or equal to the preset vertical distance threshold, judging that optical unit stitching calibration is not required.

[0094] Optionally, the processor may further execute program code for the following steps: calibrating the first optical unit and / or the second optical unit when the horizontal distance value is greater than a preset horizontal distance threshold; and / or calibrating the first optical unit and / or the second optical unit when the vertical distance value is greater than a preset vertical distance threshold.

[0095] Optionally, the processor may also execute the program code of the following steps: the first feature includes one or more feature points, and the second feature includes one or more feature points, wherein the positional relationship is determined by the center of one or more feature points of the first feature and the center of one or more feature points of the second feature.

[0096] Optionally, the processor may also execute program code of the following steps: the positional relationship includes an angular deviation between the first feature and the second feature, and the angular deviation is determined by a plurality of feature points of the first feature arranged along the vertical direction and a plurality of feature points of the second feature arranged along the vertical direction.

[0097] Optionally, the processor may also execute the program code of the following steps: including multiple first feature groups in the first feature, and multiple second feature groups in the second feature, wherein the multiple first feature groups correspond one-to-one to the multiple second feature groups, the first feature group includes one or more feature points, and the second feature group includes one or more feature points, determining the positional relationship between the first feature and the second feature, and judging whether optical unit stitching calibration is required based on the positional relationship, including: respectively calculating the distance values ​​of the central feature points in the multiple first feature groups and the corresponding central feature points in the second feature groups in the horizontal and vertical directions to obtain multiple horizontal distance values ​​and multiple vertical distance values; respectively calculating the average values ​​of the multiple horizontal distance values ​​and the multiple vertical distance values ​​to obtain the horizontal distance average value and the vertical distance average value; comparing the horizontal distance average value with a preset horizontal distance threshold, and comparing the vertical distance average value with a preset vertical distance threshold; when the horizontal distance average value is less than or equal to the preset horizontal distance threshold, and the vertical distance average value is less than or equal to the preset vertical distance threshold, judging that optical unit stitching calibration is not required.

[0098] Optionally, the processor may also execute the program code of the following steps: further comprising: calibrating the first optical unit and / or the second optical unit when the average horizontal distance is greater than a preset horizontal distance threshold; and / or calibrating the first optical unit and / or the second optical unit when the average vertical distance is greater than a preset vertical distance threshold.

[0099] Optionally, the processor may also execute program code of the following steps: the 3D printer includes at least two optical units, wherein the at least two optical units include a first optical unit and a second optical unit adjacent thereto, and the method includes: controlling the first optical unit to project light onto a first area to form a first feature, and controlling the second optical unit to project light onto a second area to form a second feature; acquiring an image of a stitching area, wherein the stitching area includes at least a portion of the first area and at least a portion of the second area, and the stitching area includes the first feature and the second feature; determining a positional relationship between the first feature and the second feature, and judging whether optical unit stitching calibration is required based on the positional relationship.

[0100] Optionally, the processor may further execute program code of the following steps: obtaining an image of the stitching area based on a lens of a handheld microscope.

[0101] Optionally, the processor may further execute program code of the following steps: a preset distance condition is satisfied between the lens and the tray, wherein the tray includes a first area and a second area.

[0102] An embodiment of the present invention provides a method for stitching and calibrating optical units of a 3D printer, by controlling a first optical unit to project light onto a first area to form a first feature, and controlling a second optical unit to project light onto a second area to form a second feature; acquiring an image of the stitching area, wherein the stitching area includes at least a portion of the first area and at least a portion of the second area, and the stitching area includes the first feature and the second feature; determining a positional relationship between the first feature and the second feature, and judging whether optical unit stitching calibration is required based on the positional relationship, thereby achieving the purpose of calibration without relying on calibration tools, thereby realizing the technical effect of improving the calibration efficiency of optical unit stitching, and further solving the technical problem in the related art of using calibration tools to perform calibration of optical unit stitching, resulting in low calibration efficiency.

[0103] A person skilled in the art will understand that all or part of the steps in the various methods of the above embodiments can be completed by instructing the hardware related to the terminal device through a program, and the program can be stored in a non-volatile storage medium, which may include: a flash drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, etc.

[0104] The embodiment of the present invention further provides a non-volatile storage medium. Optionally, in this embodiment, the non-volatile storage medium can be used to store program codes executed by the method for stitching and calibrating an optical unit of a 3D printer provided in the embodiment above.

[0105] Optionally, in this embodiment, the non-volatile storage medium may be located in any computer terminal in a computer terminal group in a computer network, or in any mobile terminal in a mobile terminal group.

[0106] Optionally, in this embodiment, the non-volatile storage medium is configured to store program codes for executing the following steps: controlling the first optical unit to project light onto the first area to form a first feature, and controlling the second optical unit to project light onto the second area to form a second feature; acquiring an image of the stitching area, wherein the stitching area includes at least a portion of the first area and at least a portion of the second area, and the stitching area includes the first feature and the second feature; determining the positional relationship between the first feature and the second feature, and determining whether optical unit stitching calibration is required based on the positional relationship.

[0107] Optionally, in this embodiment, the non-volatile storage medium is configured to store program code for executing the following steps: determining the positional relationship between the first feature and the second feature, and judging whether optical unit stitching calibration is required based on the positional relationship, including: respectively calculating the distance values ​​of the first feature and the second feature in the horizontal direction and the vertical direction; comparing the distance value in the horizontal direction with a preset horizontal distance threshold, and comparing the distance value in the vertical direction with a preset vertical distance threshold; when the distance value in the horizontal direction is less than or equal to the preset horizontal distance threshold, and the distance value in the vertical direction is less than or equal to the preset vertical distance threshold, judging that optical unit stitching calibration is not required.

[0108] Optionally, in this embodiment, the non-volatile storage medium is configured to store program code for executing the following steps: when the horizontal distance value is greater than a preset horizontal distance threshold, calibrating the first optical unit and / or the second optical unit; and / or, when the vertical distance value is greater than a preset vertical distance threshold, calibrating the first optical unit and / or the second optical unit.

[0109] Optionally, in this embodiment, the non-volatile storage medium is configured to store program code for performing the following steps: the first feature includes one or more feature points, and the second feature includes one or more feature points, wherein the positional relationship is determined by the center of the one or more feature points of the first feature and the center of the one or more feature points of the second feature.

[0110] Optionally, in this embodiment, the non-volatile storage medium is configured to store program code for performing the following steps: the positional relationship includes an angular deviation between the first feature and the second feature, and the angular deviation is determined by multiple feature points of the first feature arranged along the vertical direction and multiple feature points of the second feature arranged along the vertical direction.

[0111] Optionally, in this embodiment, the non-volatile storage medium is configured to store program code for executing the following steps: including multiple first feature groups in the first feature, and including multiple second feature groups in the second feature, wherein the multiple first feature groups correspond one-to-one to the multiple second feature groups, the first feature group includes one or more feature points, and the second feature group includes one or more feature points, determining the positional relationship between the first feature and the second feature, and judging whether optical unit stitching calibration is required based on the positional relationship, including: respectively calculating the distance values ​​of the central feature points in the multiple first feature groups and the corresponding central feature points in the second feature group in the horizontal direction and the vertical direction to obtain multiple horizontal distance values ​​and multiple vertical distance values; respectively calculating the average values ​​of the multiple horizontal distance values ​​and the multiple vertical distance values ​​to obtain the horizontal distance average value and the vertical distance average value; comparing the horizontal distance average value with a preset horizontal distance threshold, and comparing the vertical distance average value with a preset vertical distance threshold; when the horizontal distance average value is less than or equal to the preset horizontal distance threshold, and the vertical distance average value is less than or equal to the preset vertical distance threshold, judging that optical unit stitching calibration is not required.

[0112] Optionally, in this embodiment, the non-volatile storage medium is configured to store program code for executing the following steps: further comprising: calibrating the first optical unit and / or the second optical unit when the average horizontal distance is greater than a preset horizontal distance threshold; and / or calibrating the first optical unit and / or the second optical unit when the average vertical distance is greater than a preset vertical distance threshold.

[0113] Optionally, in this embodiment, the non-volatile storage medium is configured to store program code for performing the following steps: the 3D printer includes at least two optical units, wherein the at least two optical units include a first optical unit and a second optical unit adjacent to the first optical unit, and the method includes: controlling the first optical unit to project light onto the first area to form a first feature, and controlling the second optical unit to project light onto the second area to form a second feature; acquiring an image of the stitching area, wherein the stitching area includes at least a portion of the first area and at least a portion of the second area, and the stitching area includes the first feature and the second feature; determining the positional relationship between the first feature and the second feature, and judging whether optical unit stitching calibration is required based on the positional relationship.

[0114] Optionally, in this embodiment, the non-volatile storage medium is configured to store program codes for executing the following steps: acquiring an image of the stitching area is acquired based on a lens of a handheld microscope.

[0115] Optionally, in this embodiment, the non-volatile storage medium is configured to store program codes for executing the following steps: a preset distance condition is satisfied between the lens and the tray, wherein the tray includes a first area and a second area.

[0116] An embodiment of the present invention also provides a computer program product, including a computer program. Optionally, in this embodiment, when the computer program is executed by a processor, it can achieve: controlling the first optical unit to project light to the first area to form a first feature, and controlling the second optical unit to project light to the second area to form a second feature; acquiring an image of the stitching area, wherein the stitching area includes at least a portion of the first area and at least a portion of the second area, and the stitching area includes the first feature and the second feature; determining the positional relationship between the first feature and the second feature, and judging whether optical unit stitching calibration is required based on the positional relationship.

[0117] The aforementioned positional relationship can also be obtained by other means. For example, based on the first and second characteristics, the material can be solidified to form a printed object, and then the deviation between the printed objects or between two parts of the printed object can be measured using a measuring tool such as a caliper, or the deviation between the printed objects or between two parts of the printed object can be determined using a scanning tool.

[0118] The serial numbers of the above embodiments of the present invention are for description only and do not represent the advantages or disadvantages of the embodiments.

[0119] In the above embodiments of the present invention, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0120] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. Among them, the device embodiments described above are only exemplary. For example, the division of the units can be a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of units or modules, which can be electrical or other forms.

[0121] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple units. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0122] In addition, the functional units in the various embodiments of the present invention may be integrated into a single processing unit, each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0123] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a non-volatile storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, server or network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), mobile hard disk, magnetic disk or optical disk, and other media that can store program code.

[0124] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for calibrating the splicing of an optical unit of a 3D printer, characterized in that: The 3D printer includes at least two optical units, wherein the at least two optical units include a first optical unit and a second optical unit adjacent thereto, and the method includes: Controlling the first optical unit to project light onto a first area to form a first feature, and controlling the second optical unit to project light onto a second area to form a second feature; Acquire an image of a stitched area, wherein the stitched area includes at least a portion of the first area and at least a portion of the second area, and the stitched area includes a first feature and a second feature; determining a positional relationship between the first feature and the second feature; and The first optical unit and / or the second optical unit are calibrated according to the positional relationship.

2. The method according to claim 1, characterized in that The calibrating the first optical unit and / or the second optical unit according to the positional relationship includes: Calculating the distance values ​​between the first feature and the second feature in the horizontal direction and the vertical direction respectively; Comparing the horizontal distance value with a preset horizontal distance threshold, and comparing the vertical distance value with a preset vertical distance threshold; When the distance value in the horizontal direction is less than or equal to the preset horizontal distance threshold, and the distance value in the vertical direction is less than or equal to the preset vertical distance threshold, it is determined that optical unit stitching calibration is not required.

3. The method according to claim 2, characterized in that Also includes: When the distance value in the horizontal direction is greater than the preset horizontal distance threshold, calibrating the first optical unit and / or the second optical unit; and / or When the distance value in the vertical direction is greater than a preset vertical distance threshold, the first optical unit and / or the second optical unit is calibrated.

4. The method according to claim 1, wherein The first feature includes one or more feature points, and the second feature includes one or more feature points, wherein the positional relationship is determined by centers of the one or more feature points of the first feature and centers of the one or more feature points of the second feature.

5. The method according to claim 1, characterized in that The positional relationship includes an angular deviation between the first feature and the second feature, the angular deviation being determined by a plurality of first feature groups of the first feature arranged along a predetermined direction and a plurality of second feature groups of the second feature arranged along a predetermined direction.

6. The method according to claim 1, characterized in that The first optical unit and the second optical unit are the same type of optical unit, and the optical unit is selected from any one of the following: DLP, LCD, OLED, LCOS, Micro-LED, Mini-LED, liquid crystal projection.

7. The method according to any one of claims 1 to 6, characterized in that An image of the stitching area is acquired by an image acquisition device, wherein a preset distance condition is satisfied between a lens of the image acquisition device and the material tray to reduce optical distortion, wherein the material tray includes the first area and the second area.

8. The method according to claim 7, characterized in that include: The image acquisition device is a handheld microscope, wherein the handheld microscope directly contacts the material tray.

9. The method according to claim 1, characterized in that in: controlling the first optical unit and the second optical unit to project light simultaneously; or controlling the first optical unit to project light, and then controlling the second optical unit to project light; or The second optical unit is controlled to project light, and then the first optical unit is controlled to project light.

10. The method according to claim 1, characterized in that in, Based on the first feature and the second feature, a printing material is solidified to form a printing object, and then a deviation between the printing objects is measured using a measuring tool, or a scanning tool is used to determine the deviation between the printing objects.

11. A non-volatile storage medium, characterized in that: The non-volatile storage medium includes a stored program, wherein when the program is executed, the device where the non-volatile storage medium is located is controlled to execute the method for stitching calibration of an optical unit of a 3D printer according to any one of claims 1 to 10.

12. A computer device, characterized in that: include: memory and processor, The memory stores a computer program; The processor is configured to execute a computer program stored in the memory, wherein when the computer program is executed, the processor executes the method for stitching calibration of an optical unit of a 3D printer according to any one of claims 1 to 10.

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