A method, device, and laser engraving equipment for detecting the focusing state of a laser.

Abstract

This invention discloses a method, device, and laser engraving equipment for detecting the focusing state of a laser. The method for detecting the focusing state of a laser includes: obtaining the laser height after the laser is currently focused; controlling the laser to perform multiple laser engravings according to a preset laser engraving pattern at the laser height to form multiple actual laser engraving patterns; forming a focusing detection pattern in each actual laser engraving pattern, wherein the focusing detection pattern is a pattern modified based on the shape of the preset laser engraving pattern; determining the focusing capability index of the laser after it is currently focused based on the geometric parameter deviation between the focusing detection pattern and the preset laser engraving pattern, as well as the graphic deviation between the focusing detection pattern and the actual laser engraving pattern; and determining the focusing state of the laser based on the focusing capability index. The technical solution provided by this invention accurately and efficiently completes the detection of the laser focusing effect, ensuring the stability and improvement of the laser engraving process quality.

Description

Technical Field

[0001] This invention relates to the field of laser technology, and more particularly to a method, device, and laser engraving equipment for detecting the focusing state of a laser. Background Technology

[0002] In the consumer electronics manufacturing industry, products such as mobile phones, computers, watches, and headphones typically require laser engraving equipment to permanently etch product information, such as serial numbers, model numbers, and certification marks, onto their casings, internal components, or specific marking areas before they leave the factory. This process demands that the laser-engraved patterns have a clear, consistent, and precise visual effect.

[0003] Currently, before laser engraving, the laser in the laser engraving equipment needs to be focused. A common method is to test-engrave the information to be engraved on a sample or product, and then manually compare the actual engraving effect with the expected information to determine if the focus is appropriate. This method has certain drawbacks, including requiring high visual acuity from the inspectors, the results being easily influenced by subjective judgment, and increased product defect rates due to inaccurate adjustments. Therefore, how to accurately and efficiently detect the laser's focusing effect to ensure the stability and improvement of laser engraving process quality has become an urgent technical problem to be solved. Summary of the Invention

[0004] This invention provides several embodiments of a laser focusing state detection method, detection device, and laser engraving equipment. At least one embodiment is used to accurately and efficiently detect the laser focusing effect, ensuring the stability and improvement of laser engraving process quality.

[0005] According to one aspect of the present invention, a method for detecting the focusing state of a laser is provided, comprising:

[0006] Obtain the laser height after the laser is currently focused;

[0007] At the laser height, the laser is controlled to perform multiple laser engravings according to a preset laser engraving pattern to form multiple actual laser engraving patterns;

[0008] A focus detection pattern is formed in each of the actual laser engraving patterns; wherein the focus detection pattern is a pattern after the actual laser engraving pattern is modified based on the shape of the preset laser engraving pattern;

[0009] Based on the geometric parameter deviation between the focus detection pattern and the preset laser engraving pattern, and the graphic deviation between the focus detection pattern and the actual laser engraving pattern, the focusing capability index of the laser after current focusing is determined.

[0010] The focusing state of the laser is determined based on the focusing capability index.

[0011] Optionally, the preset laser engraving pattern consists of at least one target trajectory line, and each target trajectory line has a corresponding actual trajectory line in each actual laser engraving pattern; forming a focus detection pattern in each actual laser engraving pattern includes:

[0012] Determine the type of the target trajectory line corresponding to each actual trajectory line in the actual laser engraving pattern;

[0013] Based on the type of the target trajectory line corresponding to each actual trajectory line, determine the number and location of the positioning points selected on each actual trajectory line;

[0014] Based on all the positioning points on the actual trajectory line, a detection trajectory line is formed for the actual trajectory line; all the detection trajectory lines formed in each actual laser engraving pattern constitute the focus detection pattern, and the detection trajectory line is of the same type as the corresponding target trajectory line.

[0015] Optionally, the preset laser engraving pattern consists of at least one straight target trajectory line and / or at least one curved target trajectory line; determining the number and position of positioning points selected on each actual trajectory line according to the type of the target trajectory line corresponding to each actual trajectory line includes:

[0016] If the target trajectory line corresponding to the actual trajectory line is a straight line, then the two endpoints of the actual trajectory line are taken as the positioning points;

[0017] If the target trajectory line corresponding to the actual trajectory line is of the arc type, then three points on the actual trajectory line that are not on the same straight line are taken as the positioning points.

[0018] Optionally, determining the focusing capability index of the laser after current focusing based on the geometric parameter deviation between the focusing detection pattern and the preset laser engraving pattern, and the graphic deviation between the focusing detection pattern and the actual laser engraving pattern, includes:

[0019] Determine the length of at least a portion of the detection trajectory lines in each of the focus detection patterns; wherein, the at least a portion of the detection trajectory lines in different focus detection patterns are in the same position in the focus detection pattern;

[0020] Calculate the length difference between at least a portion of the detection trajectory lines and their respective target trajectory lines in each of the focus detection patterns;

[0021] Based on the length difference between at least a portion of the detection trajectory lines in each of the focus detection patterns and their respective corresponding target trajectory lines, at least one first type of focusing capability index of the laser is determined.

[0022] Determine the maximum relative distance between at least a portion of the detection trajectory lines in each of the focus detection patterns and their respective corresponding actual trajectory lines;

[0023] Based on the maximum relative distance between the at least a portion of the detected trajectory lines and their respective corresponding actual trajectory lines, at least one second-type focusing capability index of the laser is determined;

[0024] All the first-type focusing capability indices and all the second-type focusing capability indices obtained are determined as the focusing capability index of the laser after it is currently focused.

[0025] Optionally, determining at least one first-type focusing capability index of the laser based on the length difference between at least a portion of the detection trajectory lines in each of the focusing detection patterns and their corresponding target trajectory lines includes:

[0026] Based on the ratio of the length difference between the at least a portion of the detected trajectory lines and their respective corresponding target trajectory lines to the length of their respective corresponding target trajectory lines, the length error rate between the at least a portion of the detected trajectory lines and their respective corresponding target trajectory lines in each of the focusing detection patterns is obtained.

[0027] The first type of focusing capability index of the laser for lasering the target trajectory is calculated based on the average, standard deviation, upper limit and lower limit of the length error rate between all the detected trajectory lines corresponding to the same target trajectory line and the target trajectory line.

[0028] Determining at least one second-type focusing capability index of the laser based on the maximum relative distance between the at least a portion of the detected trajectory lines and their respective corresponding actual trajectory lines includes:

[0029] Based on the maximum relative distance between the at least a portion of the detection trajectory lines and their respective corresponding actual trajectory lines, and the ratio of the length of their respective corresponding target trajectory lines, the morphological error rate of at least a portion of the detection trajectory lines and their respective corresponding target trajectory lines in each of the focusing detection patterns is calculated.

[0030] The second type of focusing capability index of the laser for lasing the target trajectory is calculated based on the average, standard deviation, upper limit, and lower limit of the morphological error rates of all detected trajectories corresponding to the same target trajectory and the actual trajectory.

[0031] Optionally, the preset laser engraving pattern includes a square pattern and an inscribed circle pattern located within the square pattern; the focus detection pattern includes a square detection pattern and an inscribed circle detection pattern located within the square detection pattern.

[0032] Determining the length of at least a portion of the detection trajectory lines in each of the focus detection patterns includes:

[0033] Determine the length of each straight line segment of the square detection pattern in each of the aforementioned focus detection patterns;

[0034] Determine the length of the diameter of the inscribed circle detection pattern in each of the aforementioned focus detection patterns;

[0035] Determining the maximum relative distance between at least a portion of the detection trajectory lines and the corresponding actual trajectory lines in each of the focus detection patterns includes:

[0036] Draw parallel lines to each straight line segment in the square detection pattern, and gradually move the parallel lines from the side of the corresponding actual trajectory line away from the straight line segment towards the actual trajectory line until they overlap with the actual trajectory line, forming an offset reference line for the actual trajectory line.

[0037] Determine the relative distance from each offset reference line to the corresponding straight edge, and use it as the maximum relative distance between each detected trajectory line and the corresponding actual trajectory line.

[0038] Optionally, determining the focusing state of the laser based on the focusing capability index includes:

[0039] Determine whether all Type I autofocus capability indices and all Type II autofocus capability indices are greater than or equal to a preset lower limit.

[0040] If so, then the laser's current focus is deemed to be qualified;

[0041] If not, then the laser is determined to be currently out of focus.

[0042] Optionally, controlling the laser to perform multiple laser engravings according to a preset laser engraving pattern to form multiple actual laser engraving patterns includes:

[0043] The laser is controlled to sequentially laser-engrave multiple samples according to a preset laser-engraving pattern, so as to form an actual laser-engraved pattern on each sample.

[0044] The process of forming a focus detection pattern in each of the actual laser-engraved patterns includes:

[0045] Image of each actual laser-engraved pattern is obtained using an optical image measuring instrument;

[0046] The focus detection pattern is formed in the image of each of the actual laser-engraved patterns.

[0047] According to another aspect of the present invention, a laser focusing state detection device is provided, for performing the laser focusing state detection method according to any embodiment of the present invention, comprising:

[0048] The acquisition module is used to acquire the laser height after the laser is currently focused;

[0049] The control module is used to control the laser to perform multiple laser engravings according to a preset laser engraving pattern at the laser height, thereby forming multiple actual laser engraving patterns.

[0050] A detection pattern forming module is used to form a focus detection pattern in each of the actual laser engraving patterns; wherein, the focus detection pattern is a pattern after the actual laser engraving pattern is modified based on the shape of the preset laser engraving pattern;

[0051] The calculation module determines the focusing capability index of the laser after it is currently focused, based on the geometric parameter deviation between the focus detection pattern and the preset laser engraving pattern, and the graphic deviation between the focus detection pattern and the actual laser engraving pattern.

[0052] The judgment module is used to determine the focusing state of the laser based on the focusing capability index.

[0053] According to another aspect of the present invention, a laser engraving device is provided, including a laser, a laser height adjustment module, and a focusing state detection device as described in any embodiment of the present invention.

[0054] One embodiment of the present invention provides a technical solution that, by controlling the laser at the laser height after the laser is currently focused, performs multiple laser engravings according to a preset laser engraving pattern to form multiple actual laser engraving patterns. A focus detection pattern is formed within each actual laser engraving pattern, wherein the focus detection pattern is a pattern modified from the actual laser engraving pattern based on the shape of the preset laser engraving pattern. Based on the geometric parameter deviation between the focus detection pattern and the preset laser engraving pattern, and the graphic deviation between the focus detection pattern and the actual laser engraving pattern, the focusing capability index of the laser after the current focus is determined. Based on the focusing capability index, the focusing state of the laser is determined. This method can digitally reflect the difference between the actual engraving effect and the expected information, objectively reflecting the laser engraving effect and thus objectively reflecting the laser's focusing status, replacing the method of human visual identification. This achieves accurate and efficient detection of the laser focusing effect, ensuring the stability and improvement of the laser engraving process quality.

[0055] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0056] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0057] Figure 1 This is a flowchart of a laser focusing state detection method provided in an embodiment of the present invention;

[0058] Figure 2 This is a schematic diagram of the structure of a laser height adjustment module provided in an embodiment of the present invention;

[0059] Figure 3 This is a schematic diagram of a preset laser engraving pattern provided in an embodiment of the present invention;

[0060] Figure 4 This is a schematic diagram of an actual laser-engraved pattern formed on the surface of a first sample, provided by an embodiment of the present invention;

[0061] Figure 5 Is Figure 4 A schematic diagram showing the actual laser-engraved pattern after the focus detection pattern has been formed.

[0062] Figure 6 This is a flowchart of another laser focusing state detection method provided in an embodiment of the present invention;

[0063] Figure 7 This is a flowchart of another laser focusing state detection method provided in an embodiment of the present invention;

[0064] Figure 8 Is Figure 5 A schematic diagram showing the offset reference line after forming part of the actual trajectory line in the actual laser engraving pattern shown;

[0065] Figure 9 This is a structural block diagram of a laser focusing state detection device provided in an embodiment of the present invention. Detailed Implementation

[0066] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0067] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0068] This invention provides a method for detecting the focusing state of a laser. Figure 1 This is a flowchart of a laser focusing state detection method provided in an embodiment of the present invention, referred to as [reference]. Figure 1 Methods for detecting the focusing state of a laser include:

[0069] S110, Obtain the laser height after the laser is currently focused.

[0070] Specifically, the laser's laser height is the distance from the laser to the surface to be laser-engraved, where the surface is the surface of the product where text, numbers, letters, graphics, and other patterns need to be laser-engraved. The laser's current laser height after focusing is the distance from the laser to the surface to be laser-engraved, determined after the laser is focused. (Optional, refer to...) Figure 2 The laser is turned on to emit light. The sample (such as a metal sheet) can be placed flat on the laser engraving platform 5 in the laser height adjustment module. By rotating the rotary handle 1, the threaded rotary shaft 3 rotates, which in turn moves the laser engraving platform 5 and the sample up and down along the stable slide rail 4 to find the focal point of the laser engraving equipment, thus adjusting the laser's focal length. After focusing the laser, the distance between the laser and the surface to be engraved is determined. In other embodiments of the invention, the surface to be engraved can be kept stationary, and the distance between the laser and the surface can be adjusted by driving the laser to move, thereby focusing the laser.

[0071] S120. At the laser height, control the laser to perform multiple laser engravings according to the preset laser engraving pattern to form multiple actual laser engraving patterns.

[0072] Specifically, after obtaining the laser's current focused laser height, at that laser height, the laser is controlled to sequentially laser-engrave multiple samples onto the surfaces to be laser-engraved according to a preset laser-engraving pattern, thereby obtaining multiple actual laser-engraved patterns. The number of actual laser-engraved patterns can be set according to actual needs.

[0073] The preset laser engraving pattern consists of at least one target trajectory line, and each target trajectory line has a corresponding actual trajectory line in each actual laser engraving pattern. The target trajectory lines in the preset laser engraving pattern can be straight lines, curved lines, or a combination of straight lines and curved lines. For example, Figure 3 This is a schematic diagram of a preset laser engraving pattern provided in an embodiment of the present invention, for reference. Figure 3 The preset laser engraving pattern consists of 6 straight target trajectory lines and 1 curved target trajectory line. The actual laser engraving pattern formed on the sample surface is as follows: Figure 4 As shown, each target trajectory line has a corresponding actual trajectory line in each actual laser engraving pattern. Among them, target trajectory lines A, B, C, D, E, F, and Y correspond to actual trajectory lines A1, B1, C1, D1, E1, F1, and Y1, respectively.

[0074] Linear trajectory lines can expose focusing consistency issues along a single direction during the engraving process. If the focal length is inaccurate, when engraving long straight lines, the starting point, midpoint, and ending point of the line will exhibit uneven thickness and not be on the same straight line. Curved trajectory lines (especially small-radius arcs or circles) are more sensitive to changes in focal length. When there is a slight deviation in focal length, the energy distribution of the laser spot on the inner and outer sides of the arc will change, easily leading to arc deformation and unevenness. Setting the target trajectory line in the preset laser engraving pattern to be at least one of linear and curved trajectory lines allows this invention to flexibly adapt to different industrial scenarios and precision requirements. For rapid debugging with low precision requirements, a single type of trajectory line can be used; for high-precision, high-reliability debugging scenarios, a combination of trajectory lines can be used for comprehensive verification.

[0075] S130. A focus detection pattern is formed in each actual laser engraving pattern; wherein, the focus detection pattern is a pattern after the actual laser engraving pattern is modified based on the shape of the preset laser engraving pattern.

[0076] For example, refer to Figure 5Based on the actual laser-engraved pattern of the first sample, a detection trajectory line with the same shape as the corresponding target trajectory line is formed on one side of each actual trajectory line in the actual laser-engraved pattern. The detection trajectory lines corresponding to actual trajectory lines A1, B1, C1, D1, E1, F1, and Y1 are detection trajectory lines a1, b1, c1, d1, e1, f1, and y1, respectively. All the detection trajectory lines formed in the actual laser-engraved pattern constitute the focusing detection pattern, which is located on the same visible plane as the actual laser-engraved pattern. After forming multiple actual laser-engraved patterns, a focusing detection pattern is formed in each actual laser-engraved pattern. It should be noted that, to facilitate the distinction between the focusing detection pattern and the actual laser-engraved pattern, Figure 5 In the example, solid lines represent the actual laser engraving pattern, and dashed lines represent the focus detection pattern.

[0077] The focus detection pattern is obtained by modifying the actual laser-engraved pattern based on the shape of a preset laser-engraved pattern. The type of each line constituting the focus detection pattern is the same as the corresponding line type in the preset laser-engraved pattern, making the focus detection pattern closely resemble, or even identical to, the preset laser-engraved pattern. Furthermore, the geometric parameters of the focus detection pattern are related to the geometric parameters of the actual laser-engraved pattern. In some embodiments of the present invention, the focus detection pattern can be formed on the sample surface, such as by drawing on the sample surface. In other embodiments of the present invention, an image of each actual laser-engraved pattern can be acquired using an optical image measuring instrument; the focus detection pattern is then formed within the image of each actual laser-engraved pattern.

[0078] S140. Based on the geometric parameter deviation between the focus detection pattern and the preset laser engraving pattern, and the graphic deviation between the focus detection pattern and the actual laser engraving pattern, determine the focusing capability index of the laser after it is currently focused.

[0079] Specifically, the geometric parameter deviation between the focus detection pattern and the preset laser engraving pattern includes the length deviation between the detection trajectory line in the focus detection pattern and the corresponding target trajectory line; it can also include the deviation between the geometric parameters (e.g., radius, perimeter, height, area, etc.) of the shape enclosed by the detection trajectory line in the focus detection pattern and the geometric parameters of the shape enclosed by the corresponding target trajectory line. The geometric parameters of the actual laser engraving pattern are related to the geometric parameters of the focus detection pattern, and the geometric parameter deviation between the focus detection pattern and the preset laser engraving pattern can be used to characterize the geometric parameter deviation between the actual laser engraving pattern and the preset laser engraving pattern. The graphics of the focus detection pattern and the actual laser engraving pattern are located on the same visible plane, which facilitates the comparison of the graphics of the focus detection pattern and the actual laser engraving pattern, and thus facilitates the comparison of the graphics of the preset laser engraving pattern and the actual laser engraving pattern. The graphic deviation between the actual laser engraving pattern and the focus detection pattern is used to characterize the graphic deviation between the actual laser engraving pattern and the preset laser engraving pattern. The graphic deviation between the actual laser engraving pattern and the focus detection pattern can be determined based on the maximum deviation distance of the actual trajectory line relative to the corresponding detection trajectory line. By transforming the size and graphic differences between the actual and preset laser-engraved patterns into more convincing data, the differences in actual laser engraving effects are presented digitally, making product quality control more reliable and avoiding subjective misjudgments. Furthermore, by using the size and graphic differences between the actual and preset laser-engraved patterns to make multi-dimensional judgments on the focusing effect, the accuracy of focusing effect detection can be further improved.

[0080] S150. Determine the focusing status of the laser based on the focusing capability index.

[0081] Specifically, the acceptable range of the focusing capability index can be precisely set according to product requirements. If the focusing capability index is within the acceptable range, it means that the current focusing state of the laser meets the requirements; if the focusing capability index is outside the acceptable range, it means that the current focusing state of the laser does not meet the requirements, and it is necessary to adjust the distance between the laser and the surface to be laser-engraved to achieve focusing or focal length calibration of the laser engraving equipment.

[0082] The laser focusing state detection method provided in this invention involves controlling the laser to perform multiple laser engravings according to a preset pattern at the laser height after current focusing, forming multiple actual laser engraving patterns. A focusing detection pattern is formed within each actual laser engraving pattern, where the pattern is a modified version of the actual laser engraving pattern based on the shape of the preset pattern. The focusing capability index of the laser after current focusing is determined based on the geometric parameter deviation between the focusing detection pattern and the preset pattern, as well as the graphic deviation between the focusing detection pattern and the actual laser engraving pattern. The focusing state of the laser is then determined based on the focusing capability index. This method digitally reflects the difference between the actual engraving effect and the expected information, objectively reflecting the laser engraving effect and thus the focusing status, replacing the method of human visual identification. This achieves accurate and efficient detection of the laser focusing effect, ensuring the stability and improvement of laser engraving process quality.

[0083] Figure 6 This is a flowchart of another laser focusing state detection method provided in an embodiment of the present invention, see reference. Figure 6 Methods for detecting the focusing state of a laser include:

[0084] S210, Obtain the laser height after the laser is currently focused.

[0085] S220. At the laser height, control the laser to perform multiple laser engravings according to the preset laser engraving pattern to form multiple actual laser engraving patterns.

[0086] S230. Determine the type of target trajectory line corresponding to each actual trajectory line in the actual laser engraving pattern.

[0087] S240. Based on the type of the target trajectory line corresponding to each actual trajectory line, determine the number and location of the positioning points selected on each actual trajectory line.

[0088] S250. In each actual laser engraving pattern, based on all the positioning points on each actual trajectory line, a detection trajectory line is formed for each actual trajectory line, so as to form a focus detection pattern in each actual laser engraving pattern; the detection trajectory line is of the same type as the corresponding target trajectory line.

[0089] Specifically, the detection trajectory line passes through all the selected positioning points on the actual trajectory line, meaning the detection trajectory line and the actual trajectory line overlap at least at these positioning points. After forming the detection trajectory line based on all positioning points, the greater the overlap between the actual and detection trajectory lines, the closer their trends are (i.e., the closer their shapes are), and the closer their lengths are, the closer the laser's current focused laser height is to the focal length. The number and position of the positioning points selected on each actual trajectory line are related to the target trajectory line corresponding to that actual trajectory line.

[0090] The step of determining the number and location of positioning points on each actual trajectory line based on the type of the target trajectory line corresponding to each actual trajectory line specifically includes: if the target trajectory line corresponding to the actual trajectory line is a straight line, then the two endpoints of the actual trajectory line are used as positioning points; if the target trajectory line corresponding to the actual trajectory line is an arc, then three points on the actual trajectory line that are not on the same straight line are used as positioning points. The preset laser engraving pattern consists of at least one straight target trajectory line and / or at least one arc target trajectory line.

[0091] If the target trajectory line corresponding to the actual trajectory line is a straight line, select the starting endpoint (i.e., the first laser-engraved point) and the ending endpoint (the last laser-engraved point) on the actual trajectory line as positioning points, and draw a straight line segment connecting the starting endpoint and the ending endpoint to form the detection trajectory line of the actual trajectory line.

[0092] If the target trajectory line corresponding to the actual trajectory line is of the arc type, select three points on the actual trajectory line that are not collinear as positioning points. In plane geometry, a circle is determined by its center and radius; three non-collinear points can be used to construct a unique circle. An arc is a portion or the entire length of a circle. If the arc-shaped target trajectory line is a portion of the circle's length, the starting endpoint, ending endpoint, and a point in between on the actual trajectory line can be used as positioning points; if the arc-shaped target trajectory line is the entire length of the circle (the arc-shaped target trajectory line forms a circle), three points can be arbitrarily selected from the actual trajectory line as positioning points. After selecting three positioning points on the actual trajectory line that are not collinear, a detection trajectory line of the same type as the corresponding target trajectory line can be constructed using these three positioning points, and the geometric parameters (length of the detection trajectory line, radius of the circle containing the detection trajectory line, etc.) are related to the positions of the three positioning points of the actual trajectory line.

[0093] S260. Based on the geometric parameter deviation between the focus detection pattern and the preset laser engraving pattern, and the graphic deviation between the focus detection pattern and the actual laser engraving pattern, determine the focusing capability index of the laser after it is currently focused.

[0094] S270. Determine the focusing status of the laser based on the focusing capability index.

[0095] The technical solution provided by this invention, based on the above embodiments, includes the following steps for forming a focus detection pattern in each actual laser-engraved pattern: determining the type of the target trajectory line corresponding to each actual trajectory line in the actual laser-engraved pattern; determining the number and position of the positioning points selected on each actual trajectory line according to the type of the target trajectory line corresponding to each actual trajectory line; forming a detection trajectory line of the actual trajectory line based on all the positioning points on the actual trajectory line; and constituting a focus detection pattern by all the detection trajectory lines formed in each actual laser-engraved pattern, wherein the detection trajectory line is of the same type as the corresponding target trajectory line. Specifically, if the type of the target trajectory line corresponding to the actual trajectory line is a straight line, then the two endpoints of the actual trajectory line are used as positioning points; if the type of the target trajectory line corresponding to the actual trajectory line is an arc, then three points not on the same straight line are selected as positioning points on the actual trajectory line. This invention simplifies the process of forming a focus detection pattern by selecting an appropriate number and position of positioning points on the actual trajectory line according to the type of the target trajectory line corresponding to the actual trajectory line.

[0096] Figure 7 This is a flowchart of another laser focusing state detection method provided in an embodiment of the present invention, see reference. Figure 7 Methods for detecting the focusing state of a laser include:

[0097] S310, Obtain the laser height after the laser is currently focused.

[0098] S320. At the laser height, control the laser to perform multiple laser engravings according to the preset laser engraving pattern to form multiple actual laser engraving patterns.

[0099] S330. Determine the type of target trajectory line corresponding to each actual trajectory line in the actual laser engraving pattern.

[0100] S340. Based on the type of the target trajectory line corresponding to each actual trajectory line, determine the number and location of the positioning points selected on each actual trajectory line.

[0101] S350. In each actual laser engraving pattern, a detection trajectory line is formed based on all the positioning points on each actual trajectory line to form a focus detection pattern in each actual laser engraving pattern; the detection trajectory line is of the same type as the corresponding target trajectory line.

[0102] S360. Determine the length of at least a portion of the detection trajectory lines in each focus detection pattern; wherein at least a portion of the detection trajectory lines in different focus detection patterns are in the same position in the focus detection pattern.

[0103] Specifically, an image of each actual laser-engraved pattern can be acquired, and a focus detection pattern can be formed in the image of each actual laser-engraved pattern. Then, the length of at least a portion of the detection trajectory lines in each focus detection pattern can be determined by an optical image measuring instrument.

[0104] S370. Calculate the length difference between at least a portion of the detection trajectory lines and their corresponding target trajectory lines in each focus detection pattern.

[0105] Specifically, the lengths of the target trajectory lines in the preset laser engraving pattern are known quantities, and the lengths of the detected trajectory lines are obtained by measuring them with an optical image measuring instrument. The length difference between the detected trajectory line and the corresponding target trajectory line can be obtained by calculating the difference between their lengths.

[0106] S380. Determine at least one first-type focusing capability index of the laser based on the length difference between at least a portion of the detection trajectory lines in each focusing detection pattern and their respective corresponding target trajectory lines.

[0107] Specifically, the step of determining at least one first-type focusing capability index of the laser based on the length difference between at least a portion of the detection trajectory lines in each focus detection pattern and their corresponding target trajectory lines includes:

[0108] Based on the ratio of the length difference between at least a portion of the detection trajectory lines and their respective corresponding target trajectory lines to the length of their respective corresponding target trajectory lines, the length error rate between at least a portion of the detection trajectory lines and their respective corresponding target trajectory lines in each focus detection pattern is obtained.

[0109] The first type of focusing capability index of the laser for lasing the target trajectory is calculated based on the average, standard deviation, upper limit, and lower limit of the length error rates between all detected trajectories corresponding to the same target trajectory and the target trajectory.

[0110] S390. Determine the maximum relative distance between at least a portion of the detection trajectory lines in each focus detection pattern and their respective actual trajectory lines.

[0111] S3100, Determine at least one second-type focusing capability index of the laser based on the maximum relative distance between at least a portion of the detected trajectory lines and their respective corresponding actual trajectory lines.

[0112] Specifically, the step of determining at least one second-type focusing capability index of the laser based on the maximum relative distance between at least a portion of the detected trajectory lines and their respective corresponding actual trajectory lines includes:

[0113] Based on the maximum relative distance between at least a portion of the detection trajectory lines and their respective corresponding actual trajectory lines, and the ratio of the length of their respective corresponding target trajectory lines, calculate the morphological error rate between at least a portion of the detection trajectory lines and their respective corresponding target trajectory lines in each focus detection pattern.

[0114] The second type of focusing capability index of the laser for illuminating the target trajectory is calculated based on the average, standard deviation, upper limit, and lower limit of the morphological error rates of all detected trajectories and actual trajectories corresponding to the same target trajectory.

[0115] S3110. Determine the focusing state of the laser based on all the obtained first-type focusing capability indices and all the second-type focusing capability indices.

[0116] Specifically, all the obtained first-type focusing capability indices and all the second-type focusing capability indices are determined as the focusing capability index after the laser is currently focused. That is, the focusing capability index after the laser is currently focused includes all the determined first-type focusing capability indices and all the second-type focusing capability indices, and there are multiple such focusing capability indices. The number of first-type focusing capability indices is equal to the number of detection trajectory lines for calculating geometric parameter deviations in the one-focus detection pattern, and the number of second-type focusing capability indices is equal to the number of detection trajectory lines for calculating graphic deviations in the one-focus detection pattern.

[0117] The step of determining the laser's focusing status based on all obtained first-type focusing capability indices and all second-type focusing capability indices may include: determining whether all first-type focusing capability indices and all second-type focusing capability indices are both greater than or equal to a preset lower limit; if so, the laser's current focusing is determined to be qualified; if not, the laser's current focusing is determined to be unqualified. In other embodiments of the present invention, the laser's current focusing may also be determined to be qualified when the percentage of focusing capability indices greater than or equal to the preset lower limit is greater than a preset proportion; and the laser's current focusing may be determined to be unqualified when the percentage of focusing capability indices greater than or equal to the preset lower limit is less than or equal to a preset proportion.

[0118] The technical solution provided by this invention, based on the above embodiments, uses the CPK (Process Capability Index) calculation formula to determine a first type of focusing capability index for laser-engraving the target trajectory line based on the length error rate of all detected trajectory lines corresponding to the same target trajectory line; and uses the CPK calculation formula to determine a second type of focusing capability index for laser-engraving the target trajectory line based on the graphic error rate of all detected trajectory lines corresponding to the same target trajectory line. By judging the effect of laser-engraving at least a portion of the target trajectory lines from both geometric and graphic dimensions, accurate judgment of the actual laser-engraving effect of at least a portion of the target trajectory lines is achieved, thereby enabling precise judgment of the actual laser-engraving effect of the entire preset laser-engraved pattern. Furthermore, calculating the focusing capability index based on the CPK calculation formula provides a unified, objective, and quantitative evaluation basis for focusing effect, completely eliminating subjective judgment errors caused by individual differences.

[0119] The formula for calculating CPK is:

[0120] ;

[0121] in, This is the average value. is the standard deviation, USL is the upper limit, and LSL is the lower limit.

[0122] Based on the above embodiments, in one embodiment of the present invention, reference is made to... Figure 3 The preset laser engraving pattern includes a square pattern with diagonals and an inscribed circle pattern located within the square pattern; the focus detection pattern includes a square detection pattern and an inscribed circle detection pattern located within the square detection pattern.

[0123] Step S360, determining the length of at least a portion of the detection trajectory lines in each focus detection pattern, may specifically include:

[0124] Determine the length of each straight line segment of the square detection pattern in each focus detection pattern;

[0125] Determine the length of the diameter of the inscribed circle detection pattern in each focus detection pattern;

[0126] Step S370 determines the maximum relative distance between at least a portion of the detection trajectory lines and the corresponding actual trajectory lines in each focus detection pattern. Specifically, this may include:

[0127] Draw parallel lines to each straight line segment (straight line detection trajectory line) in the square detection pattern, and gradually move the parallel lines from the side of the corresponding actual trajectory line away from the straight line segment towards the actual trajectory line until they overlap with the actual trajectory line, forming an offset reference line for the actual trajectory line.

[0128] Determine the relative distance between each offset reference line and the corresponding straight line segment (straight line detection trajectory line), and use this distance as the maximum relative distance between each detection trajectory line and the corresponding actual trajectory line.

[0129] Specifically, if the actual trajectory line does not deform, the offset reference line completely overlaps with the actual trajectory line. If the actual trajectory line does not deform, the offset reference line partially overlaps with the actual trajectory line, and the non-overlapping part is located on the side of the actual trajectory line away from the detection trajectory line.

[0130] For example, refer to Figure 8 Offset reference lines are drawn for the actual trajectory lines A1, B1, C1, D1, E1, and F1, respectively, as offset reference line Ax1, offset trajectory line Bx1, offset trajectory line Cx1, offset trajectory line Dx1, offset trajectory line Ex1, and offset trajectory line Fx1. The relative distances from each offset trajectory line (Ax1, Bx1, Cx1, Dx1, Ex1, Fx1) to the corresponding detection trajectory lines (a1, b1, c1, d1, e1, f1) are determined, thus obtaining the maximum relative distance between each actual trajectory line and its corresponding detection trajectory line.

[0131] Based on the above embodiments, taking a preset laser engraving pattern that includes a square pattern with diagonals and an inscribed circle pattern located within the square pattern, with an actual number of 32 laser engraving patterns, the laser focusing state detection process is explained in detail as follows:

[0132] Prepare 32 metal sheets, and at the laser height, control the laser to follow the direction as follows. Figure 3 The preset laser engraving pattern shown is sequentially laser engraved on the surfaces of 32 metal sheets to obtain 32 actual laser engraving patterns. The preset laser engraving pattern includes target trajectory lines: straight target trajectory lines A, B, C, D, E, and F, and arc-shaped target trajectory line Y. Straight target trajectory lines A, B, C, and D are the straight sides of a square pattern, and straight target trajectory lines E and F are the diagonals of the square pattern. The arc-shaped target trajectory line Y forms an inscribed circle pattern with radius R. The lengths of the straight target trajectory lines A, B, C, D, E, and F are LA, LB, LC, LD, LE, and LF, respectively.

[0133] The image of the actual laser-engraved pattern on the first metal sheet is obtained using an optical imaging machine (OMM). Figure 4 As shown), a focus detection pattern is formed in the image of the actual laser-engraved pattern on the first metal sheet (such as...). Figure 5(As shown); the detection pattern includes detection trajectory lines comprising straight line segments a1, b1, c1, d1, e1, f1 and arc y1, corresponding to target trajectory lines A, B, C, D, E, F, Y, respectively. The lengths of the measured straight line segments a1, b1, c1, d1, e1, f1 are La1, Lb1, Lc1, Ld1, Le1, Lf1, respectively, and the radius of the circle enclosed by the measured arc y1 is r1.

[0134] Calculate the length error rate of the circle formed by the detection trajectory lines a1, b1, c1, d1, e1, f1, y, relative to the radius of the circle formed by the target trajectory lines A, B, C, D, E, F, Y: , , , , , , ;like Figure 8 As shown, parallel lines to the detection trajectory lines a1, b1, c1, d1, e1, and f1 are drawn on the outermost side of the actual laser-engraved pattern, serving as offset reference lines for the actual trajectory lines. The relative distances from the offset reference lines Ax1, Bx1, Cx1, Dx1, Ex1, and Fx1 to their respective detection trajectory lines a1, b1, c1, d1, e1, and f1 are calculated as Ga1, Gb1, Gc1, Gd1, Ge1, and Gf1, respectively. Then, the shape error rates between the detection trajectory lines a1, b1, c1, d1, e1, and f1 and their respective actual trajectory lines are calculated as follows: , , , , , It should be noted that when the offset reference line is above, to the right, lower right, or upper right of the detection trajectory line, the relative distance is a positive value; when the offset reference line is below, to the left, upper left, or lower left of the detection trajectory line, the relative distance is a negative value. For example, if the offset reference line Ax1 is located to the left of the detection trajectory line a1, then the maximum relative distance between the offset reference line Ax1 and the detection trajectory line a1 is a negative value; if the offset reference line Bx1 is located above the detection trajectory line b1, then the maximum relative distance between the offset reference line Bx1 and the detection trajectory line b1 is a positive value.

[0135] The image of the actual laser-engraved pattern on the second metal sheet is obtained using an OMM (Optical Marking Machine), and a focus detection pattern is formed within the actual laser-engraved pattern. The focus detection pattern includes detection trajectory lines consisting of straight line segments a2, b3, c4, d5, e2, f2 and arc y2. The lengths of the straight line segments a2, b2, c2, d2, e2, and f2 are measured to be La2, Lb2, Lc2, Ld2, Le2, and Lf2, respectively, and the radius of the circle enclosed by the arc y2 is measured to be r2.

[0136] Calculate the length error rate of the circle formed by the detection trajectory lines a2, b2, c2, d2, e2, f2, y, relative to the radius of the circle formed by the target trajectory lines A, B, C, D, E, F, and arc Y: , , , , , , Parallel lines to the detection trajectory lines a2, b2, c2, d2, e2, and f2 are drawn on the outermost side of the actual laser-engraved pattern. These are used as offset reference lines for the actual trajectory lines. The relative distances from the corresponding offset reference lines to the detection trajectory lines a2, b2, c2, d2, e2, and f2 are calculated as Ga2, Gb2, Gc2, Gd2, Ge2, and Gf2, respectively. Then, the shape error rates between the detection trajectory lines a2, b2, c2, d2, e2, and f2 and their respective actual trajectory lines are calculated as follows: , , , , , .

[0137] This process continues until the data for all 32 actual laser-engraved patterns has been acquired.

[0138] Calculate the mean and standard deviation of the length error rates (Pa1~Pa32) of all detection trajectories (a1~a32) corresponding to the linear target trajectory line A relative to the linear target trajectory line A;

[0139] Calculate the mean and standard deviation of the length error rates (Pb1~Pb32) of all detection trajectories (b1~b32) corresponding to the linear target trajectory line B relative to the linear target trajectory line B;

[0140] Calculate the mean and standard deviation of the length error rates (Pc1~Pc32) of all detection trajectories (c1~c32) corresponding to the linear target trajectory line C relative to the linear target trajectory line C;

[0141] Calculate the mean and standard deviation of the length error rates (Pd1~Pd32) of all detection trajectories (d1~d32) corresponding to the linear target trajectory line D relative to the linear target trajectory line D;

[0142] Calculate the mean and standard deviation of the length error rates (Pe1~Pe32) of all detection trajectories (e1~e32) corresponding to the linear target trajectory line E relative to the linear target trajectory line E;

[0143] Calculate the mean and standard deviation of the length error rates (Pf1~Pf32) of all detection trajectories (f1~f32) corresponding to the linear target trajectory line F relative to the linear target trajectory line F;

[0144] Calculate the mean and standard deviation of the radius length error rate (Pr1~Pr32) of the circle formed by all detection trajectory lines (y1~y32) corresponding to the arc-shaped target trajectory line Y relative to the straight-line target trajectory line Y;

[0145] Calculate the mean and standard deviation of the graphic error rates (Qa1~Qa32) between all the detected trajectory lines (a1~a32) corresponding to the linear target trajectory line A and their respective actual trajectory lines (A1~A32);

[0146] Calculate the average and standard deviation of the graphic error rates (Qb1~Qb32) between all the detected trajectory lines (b1~b32) corresponding to the linear target trajectory line B and their respective actual trajectory lines (B1~B32);

[0147] Calculate the mean and standard deviation of the graphic error rates (Qc1~Qc32) between all the detected trajectory lines (c1~c32) corresponding to the linear target trajectory line C and their respective actual trajectory lines (C1~C32);

[0148] Calculate the mean and standard deviation of the graphic error rates (Qd1~Qd32) between all the detected trajectory lines (d1~d32) corresponding to the linear target trajectory line D and their respective actual trajectory lines (D1~D32);

[0149] Calculate the mean and standard deviation of the graphic error rates (Qe1~Qe32) between all the detected trajectory lines (e1~e32) corresponding to the linear target trajectory line E and their respective actual trajectory lines (E1~E32);

[0150] Calculate the mean and standard deviation of the graphic error rates (Qf1~Qf32) between all the detected trajectory lines (f1~f32) corresponding to the linear target trajectory line F and their respective actual trajectory lines (F1~F32).

[0151] The average of each error rate and standard deviation Substitute into the formula The corresponding focusing capability index is calculated. The upper limit (USL) and lower limit (LSL) of each error rate are set according to actual needs. In this embodiment of the invention, 13 focusing capability indices are obtained. The acceptable range for the focusing capability index can be set to greater than or equal to 1.2. It is determined whether all 13 focusing capability indices are greater than or equal to 1.2. If so, the current focusing state is considered acceptable; otherwise, the current focusing state is considered unacceptable.

[0152] This invention also provides a device for detecting the focusing state of a laser. Figure 9 This is a structural block diagram of a laser focusing state detection device provided in an embodiment of the present invention, with reference to... Figure 9 The laser focusing state detection device includes:

[0153] The acquisition module 10 is used to acquire the laser height after the laser is currently focused;

[0154] Control module 20 is used to control the laser to perform multiple laser engravings according to the preset laser engraving pattern at the laser height, so as to form multiple actual laser engraving patterns;

[0155] The detection pattern forming module 30 is used to form a focus detection pattern in each actual laser engraving pattern; wherein, the focus detection pattern is a pattern after the actual laser engraving pattern is corrected based on the shape of the preset laser engraving pattern.

[0156] The calculation module 40 determines the focusing capability index of the laser after it is currently focused, based on the geometric parameter deviation between the focus detection pattern and the preset laser engraving pattern, and the graphic deviation between the focus detection pattern and the actual laser engraving pattern.

[0157] The judgment module 50 is used to determine the focusing status of the laser based on the focusing capability index.

[0158] The laser focusing state detection device provided in this embodiment of the invention can execute the focusing state detection method provided in any embodiment of the invention, and has the corresponding functional modules and beneficial effects of the method.

[0159] This invention also provides a laser engraving device, including a laser, a laser height adjustment module, and a laser focusing state detection device provided in any embodiment of this invention. It possesses corresponding beneficial effects, which will not be elaborated upon here.

[0160] Optional, see reference Figure 2The laser height adjustment module includes a rotary handle 1, a locking screw 2, a threaded rotary shaft 3, a stabilizing slide rail 4, a laser engraving platform 5, and a vernier caliper 6. Rotating the rotary handle 1 drives the threaded rotary shaft 3 to rotate; the rotation of the threaded rotary shaft 3 drives the laser engraving platform 5 to move along the stabilizing slide rail 4. The sample to be laser engraved is placed on the laser engraving platform 5. By rotating the rotary handle 1, the threaded rotary shaft 3 rotates, which in turn moves the laser engraving platform 5 and the sample to be laser engraved up and down along the stabilizing slide rail 4, thereby adjusting the distance between the laser and the sample, i.e., adjusting the laser height. The rotational motion of the rotary shaft is converted into driving the laser engraving platform to move vertically. The slide rail acts as a guide, simplifying the drive structure, eliminating the need for a cylinder, and reducing equipment costs.

[0161] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. A method for detecting the focusing state of a laser, characterized in that, include: Obtain the laser height after the laser is currently focused; At the laser height, the laser is controlled to perform multiple laser engravings according to a preset laser engraving pattern to form multiple actual laser engraving patterns; A focus detection pattern is formed in each of the actual laser engraving patterns; wherein, the focus detection pattern is a pattern after the actual laser engraving pattern is modified based on the shape of the preset laser engraving pattern; the preset laser engraving pattern is composed of at least one target trajectory line, and each target trajectory line has a corresponding actual trajectory line in each actual laser engraving pattern; the detection trajectory line of the focus detection pattern is of the same type as the corresponding target trajectory line. Based on the geometric parameter deviation between the focus detection pattern and the preset laser engraving pattern, and the graphic deviation between the focus detection pattern and the actual laser engraving pattern, the focusing capability index of the laser after current focusing is determined; the geometric parameter deviation includes the length difference between at least a portion of the detection trajectory lines in the focus detection pattern and their respective corresponding target trajectory lines; the graphic deviation includes the maximum relative distance between at least a portion of the detection trajectory lines in the focus detection pattern and their respective corresponding actual trajectory lines; The focusing state of the laser is determined based on the focusing capability index.

2. The method for detecting the focusing state of a laser according to claim 1, characterized in that, The process of forming a focus detection pattern in each of the actual laser-engraved patterns includes: Determine the type of the target trajectory line corresponding to each actual trajectory line in the actual laser engraving pattern; Based on the type of the target trajectory line corresponding to each actual trajectory line, determine the number and location of the positioning points selected on each actual trajectory line; In each of the actual laser engraving patterns, a detection trajectory line is formed based on all the positioning points on each actual trajectory line, so as to form the focus detection pattern in each of the actual laser engraving patterns.

3. The method for detecting the focusing state of a laser according to claim 2, characterized in that, The preset laser engraving pattern consists of at least one straight target trajectory line and / or at least one curved target trajectory line; determining the number and position of positioning points selected on each actual trajectory line according to the type of the target trajectory line corresponding to each actual trajectory line includes: If the target trajectory line corresponding to the actual trajectory line is a straight line, then the two endpoints of the actual trajectory line are taken as the positioning points; If the target trajectory line corresponding to the actual trajectory line is of the arc type, then three points on the actual trajectory line that are not on the same straight line are taken as the positioning points.

4. The method for detecting the focusing state of a laser according to claim 2, characterized in that, The step of determining the focusing capability index of the laser after current focusing based on the geometric parameter deviation between the focusing detection pattern and the preset laser engraving pattern, and the graphic deviation between the focusing detection pattern and the actual laser engraving pattern, includes: Determine the length of at least a portion of the detection trajectory lines in each of the focus detection patterns; wherein, the at least a portion of the detection trajectory lines in different focus detection patterns are in the same position in the focus detection pattern; Calculate the length difference between at least a portion of the detection trajectory lines and their respective target trajectory lines in each of the focus detection patterns; Based on the length difference between at least a portion of the detection trajectory lines in each of the focus detection patterns and their respective corresponding target trajectory lines, at least one first type of focusing capability index of the laser is determined. Determine the maximum relative distance between at least a portion of the detection trajectory lines in each of the focus detection patterns and their respective corresponding actual trajectory lines; Based on the maximum relative distance between the at least a portion of the detected trajectory lines and their respective corresponding actual trajectory lines, at least one second-type focusing capability index of the laser is determined; All the first-type focusing capability indices and all the second-type focusing capability indices obtained are determined as the focusing capability index of the laser after it is currently focused.

5. The method for detecting the focusing state of a laser according to claim 4, characterized in that, The step of determining at least one first-type focusing capability index of the laser based on the length difference between at least a portion of the detection trajectory lines in each of the focusing detection patterns and their respective corresponding target trajectory lines includes: Based on the ratio of the length difference between the at least a portion of the detected trajectory lines and their respective corresponding target trajectory lines to the length of their respective corresponding target trajectory lines, the length error rate between the at least a portion of the detected trajectory lines and their respective corresponding target trajectory lines in each of the focusing detection patterns is obtained. The first type of focusing capability index of the laser for lasering the target trajectory is calculated based on the average, standard deviation, upper limit and lower limit of the length error rate between all the detected trajectory lines corresponding to the same target trajectory line and the target trajectory line. Determining at least one second-type focusing capability index of the laser based on the maximum relative distance between the at least a portion of the detected trajectory lines and their respective corresponding actual trajectory lines includes: Based on the maximum relative distance between the at least a portion of the detection trajectory lines and their respective corresponding actual trajectory lines, and the ratio of the length of their respective corresponding target trajectory lines, the morphological error rate of at least a portion of the detection trajectory lines and their respective corresponding target trajectory lines in each of the focusing detection patterns is calculated. The second type of focusing capability index of the laser for lasing the target trajectory is calculated based on the average, standard deviation, upper limit, and lower limit of the morphological error rates of all detected trajectories corresponding to the same target trajectory and the actual trajectory.

6. The method for detecting the focusing state of a laser according to claim 4, characterized in that, The preset laser engraving pattern includes a square pattern with diagonals and an inscribed circle pattern located within the square pattern; the focus detection pattern includes a square detection pattern and an inscribed circle detection pattern located within the square detection pattern; Determining the length of at least a portion of the detection trajectory lines in each of the focus detection patterns includes: Determine the length of each straight line segment of the square detection pattern in each of the aforementioned focus detection patterns; Determine the length of the diameter of the inscribed circle detection pattern in each of the aforementioned focus detection patterns; Determining the maximum relative distance between at least a portion of the detection trajectory lines and the corresponding actual trajectory lines in each of the focus detection patterns includes: Draw parallel lines to each straight line segment in the square detection pattern, and gradually move the parallel lines from the side of the corresponding actual trajectory line away from the straight line segment towards the actual trajectory line until they overlap with the actual trajectory line, forming an offset reference line for the actual trajectory line. Determine the relative distance from each offset reference line to the corresponding straight edge, and use it as the maximum relative distance between each detected trajectory line and the corresponding actual trajectory line.

7. The method for detecting the focusing state of a laser according to claim 4, characterized in that, Determining the focusing state of the laser based on the focusing capability index includes: Determine whether all Type I autofocus capability indices and all Type II autofocus capability indices are greater than or equal to a preset lower limit. If so, then the laser's current focus is deemed to be qualified; If not, then the laser is determined to be currently out of focus.

8. The method for detecting the focusing state of a laser according to claim 1, characterized in that, The control of the laser to perform multiple laser engravings according to a preset laser engraving pattern, forming multiple actual laser engraving patterns, includes: The laser is controlled to sequentially laser-engrave multiple samples according to a preset laser-engraving pattern, so as to form an actual laser-engraved pattern on each sample. The process of forming a focus detection pattern in each of the actual laser-engraved patterns includes: Image of each actual laser-engraved pattern is obtained using an optical image measuring instrument; The focus detection pattern is formed in the image of each of the actual laser-engraved patterns.

9. A device for detecting the focusing state of a laser, characterized in that, A method for detecting the focusing state of a laser according to any one of claims 1 to 8, comprising: The acquisition module is used to acquire the laser height after the laser is currently focused; The control module is used to control the laser to perform multiple laser engravings according to a preset laser engraving pattern at the laser height, thereby forming multiple actual laser engraving patterns. A detection pattern forming module is used to form a focus detection pattern in each of the actual laser engraving patterns; wherein, the focus detection pattern is a pattern after the actual laser engraving pattern is modified based on the shape of the preset laser engraving pattern; The calculation module determines the focusing capability index of the laser after it is currently focused, based on the geometric parameter deviation between the focus detection pattern and the preset laser engraving pattern, and the graphic deviation between the focus detection pattern and the actual laser engraving pattern. The judgment module is used to determine the focusing state of the laser based on the focusing capability index.

10. A laser engraving device, characterized in that, It includes a laser, a laser height adjustment module, and a device for detecting the focus state of the laser as described in claim 9.

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