A focusing method of a laser, a focusing control device and a laser engraving equipment

Abstract

The application discloses a focusing method of a laser, a focusing control device and a laser etching equipment. The focusing method of the laser comprises the following steps: taking a current reference height as a starting point, determining a plurality of different laser etching heights of the laser according to a current height adjustment step; at each laser etching height, controlling the laser to etch a plurality of light spots, and determining an average diameter of the light spots corresponding to each laser etching height; determining whether the laser etching height corresponding to the minimum average diameter of the light spots meets a preset focusing qualified condition; if not, determining a next reference height and a next height adjustment step according to the size relationship of the average diameters of the light spots corresponding to the plurality of different laser etching heights, repeating the above steps until the laser etching height corresponding to the minimum average diameter of the light spots meets the preset focusing qualified condition. The technical scheme provided by the application realizes accurate and efficient laser focusing, and ensures the stability and improvement of the laser etching process quality.

Description

Technical Field

[0001] This invention relates to the field of laser technology, and more particularly to a laser focusing method, a focusing control device, and a laser engraving equipment. 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 or text 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 turn on the laser and test the brightness of the light produced when the laser strikes a metal sheet or material, thus determining if the laser is focused. This method has drawbacks. It relies entirely on the operator's ability to discern the brightness of the laser spot. Differences in visual sensitivity and experience among operators, as well as ambient light interference, can lead to inconsistent judgments of the "brightest" state, introducing human error. Furthermore, the human eye has limited ability to perceive minute changes in brightness, making it difficult to accurately pinpoint the focal point with the highest energy density. This can result in extremely unfavorable effects on fine laser engraving, such as light color and excessively wide line widths. Therefore, how to accurately and efficiently achieve laser focusing to ensure the stability and improvement of laser engraving quality has become a pressing technical problem. Summary of the Invention

[0004] One embodiment of the present invention provides a laser focusing method, a focusing control device, and a laser engraving equipment to accurately and efficiently complete laser focusing, thereby ensuring the stability and improvement of laser engraving process quality.

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

[0006] Determine the laser's current reference height and current height adjustment step size;

[0007] Starting from the current reference height, the step size is adjusted according to the current height to determine multiple different laser heights of the laser. The multiple different laser heights include at least the current reference height, at least one first height higher than the current reference height, and at least one second height lower than the current reference height.

[0008] At each laser height, the laser is controlled to etch multiple light spots, and the average diameter of the light spot corresponding to each laser height is determined;

[0009] Determine whether the laser height corresponding to the minimum average spot diameter meets the preset conditions for focusing qualification.

[0010] If the conditions are not met, the next reference height and the next height adjustment step are determined based on the relationship between the average diameters of the laser spots corresponding to the multiple different laser heights. The next reference height and the next height adjustment step are then replaced with the current reference height and the current height adjustment step, respectively. The above steps are repeated until the laser height corresponding to the smallest average laser spot diameter meets the preset conditions for focusing.

[0011] Optionally, determining the next reference height and the next height adjustment step distance based on the relationship between the average diameters of the laser spots corresponding to the multiple different laser heights includes:

[0012] When the laser height corresponding to the minimum average diameter of the laser spot is the minimum among the plurality of different laser heights, the current height adjustment step is determined as the next height adjustment step, and the difference between the minimum among the plurality of different laser heights and (n-1) / 2 times the height adjustment step is determined as the next reference height.

[0013] When the laser height corresponding to the minimum average laser spot diameter is the maximum value among the plurality of different laser heights, the current height adjustment step is determined as the next height adjustment step, and the sum of the maximum value among the plurality of different laser heights and (n-1) / 2 times the height adjustment step is determined as the next reference height;

[0014] When the laser height corresponding to the minimum average laser diameter is neither the maximum nor the minimum among the plurality of different laser heights, the laser height corresponding to the minimum average laser diameter is determined as the next reference height, and the ratio of the difference between two laser heights adjacent to the laser height corresponding to the minimum average laser diameter to (n-1) is determined as the next height adjustment step.

[0015] Where n is an odd number greater than 3, and n is the number of the plurality of different laser heights.

[0016] Optionally, determine the average spot diameter corresponding to each laser height, including:

[0017] The diameter of the multiple laser spots laser-etched at each laser height is measured using an optical image measuring instrument;

[0018] Calculate the average diameter of the plurality of laser spots at each laser height to obtain the average diameter of the laser spot corresponding to each laser height.

[0019] Optionally, determining whether the laser height corresponding to the minimum average spot diameter meets the preset focusing qualification conditions includes:

[0020] Determine whether the difference between the diameters of two adjacent laser spots etched by the laser height corresponding to the minimum average diameter of the laser spot is less than or equal to the maximum allowable deviation of the laser engraving information line width;

[0021] If so, then determine that the laser height corresponding to the minimum average spot diameter meets the preset conditions for focusing qualification;

[0022] If not, then the laser height corresponding to the minimum average spot diameter does not meet the preset conditions for focusing.

[0023] Optionally, the focusing method of the laser further includes:

[0024] The maximum permissible deviation of the laser engraving line width is determined based on the maximum permissible line width and the minimum permissible line width of the laser engraving information.

[0025] Optionally, the focusing method of the laser further includes:

[0026] Obtain the focal length range of the laser;

[0027] Based on the focal length range of the laser, determine the initial reference height and the initial height adjustment step size of the laser.

[0028] Optionally, determining the initial reference height and initial height adjustment step distance of the laser based on the focal length range of the laser includes:

[0029] The initial reference height of the laser is determined based on the median value of the focal length range of the laser.

[0030] The initial height adjustment step is determined based on the focal length range of the laser and the preset number of the plurality of different laser heights.

[0031] Optionally, at each laser height, controlling the laser to etch multiple laser spots includes:

[0032] At each laser height, the laser is controlled to laser-etch multiple light spots arranged in sequence at intervals on the same surface to be laser-etched, so that the multiple light spots lasered at different laser heights form a light spot matrix on the same surface to be laser-etched.

[0033] According to another aspect of the present invention, a laser focusing control device is provided for performing the laser focusing method described in any embodiment of the present invention, comprising:

[0034] The height and step size determination module is used to determine the current reference height and current height adjustment step size of the laser.

[0035] A laser height determination module is used to determine multiple different laser heights of the laser by adjusting the step size according to the current reference height, starting from the current reference height. The multiple different laser heights include at least the current reference height, at least one first height higher than the current reference height, and at least one second height lower than the current reference height.

[0036] The control module is used to control the laser to engrave multiple light spots at each laser height;

[0037] The average diameter determination module is used to determine the average diameter of the laser spot corresponding to each laser height;

[0038] The focus judgment module is used to determine whether the laser height corresponding to the minimum average diameter of the light spot meets the preset conditions for focus qualification.

[0039] The height and step size adjustment module is used to determine the next reference height and the next height adjustment step size based on the relationship between the average diameter of the spot corresponding to the multiple different laser heights when the conditions are not met, and to replace the next reference height and the next height adjustment step size with the current reference height and the current height adjustment step size respectively.

[0040] According to another aspect of the present invention, a laser engraving device is provided, including a laser and a focusing control device for the laser as described in any embodiment of the present invention.

[0041] One embodiment of the present invention provides a technical solution that involves laser engraving a laser spot at multiple different laser heights, measuring the spot diameter to find the laser height corresponding to the minimum average spot diameter, and then using this laser height as a basis to find multiple more laser heights for judgment, until the difference between the diameters of two adjacent laser spots engraved at the laser height corresponding to the minimum average spot diameter meets the preset conditions for focusing, thereby completing laser focusing. This method can digitally reflect the laser focusing status and accurately locate the laser focal height according to product requirements, replacing the method of human visual identification, thus achieving accurate and efficient laser focusing and ensuring the stability and improvement of laser engraving process quality.

[0042] 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

[0043] 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.

[0044] Figure 1 This is a flowchart of a laser focusing method provided in an embodiment of the present invention;

[0045] Figure 2 This is a schematic diagram of laser focusing when the laser beam height is equal to the focal length, provided by an embodiment of the present invention.

[0046] Figure 3 This is a schematic diagram of laser focusing when the laser beam height is less than the focal length, provided by an embodiment of the present invention.

[0047] Figure 4 This is a schematic diagram of laser focusing when the laser beam height is greater than the focal length, provided by an embodiment of the present invention.

[0048] Figure 5 This is a flowchart of another laser focusing method provided in an embodiment of the present invention;

[0049] Figure 6 This is a laser spot matrix diagram provided by an embodiment of the present invention when the laser height corresponding to the minimum average laser spot diameter is neither the maximum nor the minimum value among multiple different laser heights;

[0050] Figure 7 This is a laser spot matrix diagram provided by an embodiment of the present invention when the laser height corresponding to the minimum average diameter of the laser spot is the minimum among multiple different laser heights;

[0051] Figure 8 This is a laser spot matrix diagram provided by an embodiment of the present invention when the laser height corresponding to the minimum average laser spot diameter is the maximum value among multiple different laser heights;

[0052] Figure 9 This is a flowchart of another laser focusing method provided in an embodiment of the present invention;

[0053] Figure 10 This is a schematic diagram of a laser-engraved information pattern provided in an embodiment of the present invention;

[0054] Figure 11 This is a structural block diagram of a laser focusing control device provided in an embodiment of the present invention. Detailed Implementation

[0055] 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.

[0056] 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.

[0057] This invention provides a method for focusing a laser. Figure 1 This is a flowchart of a laser focusing method provided in an embodiment of the present invention, see reference. Figure 1 The focusing methods for lasers include:

[0058] S110, Obtain the current reference height and current height adjustment step of the laser.

[0059] S120. Starting from the current reference height, adjust the step size according to the current height to determine multiple different laser heights of the laser, wherein the multiple different laser heights include at least the current reference height, at least one first height higher than the current reference height, and at least one second height lower than the current reference height.

[0060] Specifically, the laser height is the distance from the laser to the surface to be laser-engraved, where the surface to be laser-engraved is the surface of the product where text, numbers, letters, graphics, and other pattern information need to be laser-engraved.

[0061] refer to Figures 2-4 The laser beam is focused onto the surface 11 to be laser-engraved after passing through the convex mirror 21 in the laser, including three cases: such as Figure 2 As shown, the height of the laser from the product is exactly equal to the focal length. The laser beam emitted by the laser is focused at a single point on the surface to be laser-engraved (11), resulting in the darkest and smallest spot. Figure 3As shown, when the height of the laser from the surface 11 to be laser-engraved is less than the focal length, the laser beam emitted by the laser is not focused on a single point on the surface 11. Therefore, the resulting laser spot is slightly lighter in color and slightly larger in diameter. Figure 4 As shown, when the laser's height relative to the product is greater than the focal length, the laser beam emitted by the laser is not focused at a single point on the surface 11 to be laser-engraved. The resulting laser spot is slightly lighter in color and larger in diameter. Therefore, the size of the laser spot formed on the surface 11 to be laser-engraved is related to the distance between the laser and the surface 11. The area of ​​the laser spot at the focal point is the smallest, and therefore the power density of the laser spot at the focal point is the highest, making it easier for the material on the surface 11 to evaporate.

[0062] The focusing process of a laser can be transformed into determining the laser height that produces the smallest laser spot. The shape of the laser spot is usually circular or approximately circular, so the spot area can be compared by comparing the spot diameter. Setting multiple different laser heights allows the laser to etch a laser spot at these heights, resulting in spots of different diameters. This facilitates finding the smallest diameter spot or a spot with a diameter close to the smallest diameter, thus achieving laser focusing. In this embodiment, the step of setting multiple different laser heights is as follows: setting a reference height and a height adjustment step size for the laser; starting from the reference height, determining multiple different laser heights based on the height adjustment step size; wherein the multiple different laser heights include at least the reference height, at least one first height higher than the reference height, and at least one second height lower than the reference height. Since the currently set multiple laser heights may not include the laser height corresponding to the focal length, meaning the smallest laser spot etched at the set multiple laser heights may not be the smallest area spot (the laser spot etched at the laser height corresponding to the focal length), there are situations where multiple laser height settings are required. The current reference height is the reference height used when setting multiple different laser heights, and the current height adjustment step is the height adjustment step used when setting multiple different laser heights.

[0063] It should be noted that the laser height corresponding to the focal length can be equal to or approximately equal to the focal length, as long as the focus qualification preset condition is met. The focus qualification preset condition can be set according to actual needs. In addition, since each time multiple different laser heights are set, there will be a minimum spot at each of the different laser heights. To distinguish it from the spot laser-etched at the laser height corresponding to the focal length, the spot laser-etched at the laser height corresponding to the focal length will be referred to as the target spot, and the laser height corresponding to the focal length will be referred to as the target laser height.

[0064] S130. At each laser height, control the laser to etch multiple light spots and determine the average diameter of the light spot corresponding to each laser height.

[0065] Specifically, the distance between the laser and the surface to be laser-etched is adjusted, thereby regulating the laser's tracing height. At each tracing height, the laser is controlled to etch multiple spots, i.e., a group of spots is etched at each laser height. Based on the diameters of the multiple spots etched at each laser height, the average diameter of the spots corresponding to each laser height is determined. Determining the average diameter of the spots corresponding to each laser height, compared to obtaining the diameter of a single spot at each laser height, improves the accuracy and reliability of the data and eliminates random errors. The number of spots etched at different laser heights can be the same or different, depending on actual needs. For example, the number of spots etched at each laser height can be 3, 4, 5, 6, 7, 8, 9, 10, 12, 15, 20, etc., as required.

[0066] S140. Determine whether the laser height corresponding to the minimum average spot diameter meets the preset conditions for focusing.

[0067] Specifically, the minimum average spot diameter can be understood as the minimum average of the average spot diameters among multiple spot groups obtained at several different laser heights. Once the minimum average spot diameter is determined, it becomes possible to identify which spot group will have the smallest spot in this focusing process. Since the laser height used to carve this spot group should be the laser height closest to the focal length among multiple different laser heights, it is determined whether the laser height corresponding to the minimum average spot diameter meets the preset focusing conditions. If it does, this laser height is set as the target laser height, completing the focusing of the laser; if not, multiple different laser heights are reset, and the next focusing round continues.

[0068] Optionally, in one embodiment of the present invention, the laser height can be determined to meet the preset conditions for focusing based on the range of the diameter of the laser spot etched by the laser height corresponding to the minimum average spot diameter. In another embodiment of the present invention, since the smaller the difference in diameter between adjacent spots, the more accurate the focusing effect, the step of determining whether the laser height corresponding to the minimum average spot diameter meets the preset conditions for focusing can specifically include: determining whether the difference in diameter between two adjacent spots etched by the laser height corresponding to the minimum average spot diameter meets a preset difference; if it does, the laser height corresponding to the minimum average spot diameter meets the preset conditions for focusing; if it does not, the laser height corresponding to the minimum average spot diameter does not meet the preset conditions for focusing. In another embodiment of the present invention, the laser height corresponding to the minimum average spot diameter can be determined to meet the preset conditions for focusing by determining whether the range of the diameter of the laser spot etched by the laser height corresponding to the minimum average spot diameter, and whether the difference in diameter between two adjacent spots etched by the laser height corresponding to the minimum average spot diameter meets their respective conditions.

[0069] S150. If the conditions are not met, determine the next reference height and the next height adjustment step based on the relationship between the average diameter of the light spots corresponding to multiple different laser heights. Replace the next reference height and the next height adjustment step with the current reference height and the current height adjustment step, respectively. Repeat the above steps until the laser height corresponding to the smallest average diameter of the light spot meets the preset conditions for focusing.

[0070] Specifically, if the conditions are not met, the reference height and the next height adjustment step distance are determined based on the relationship between the average diameter of the light spot corresponding to the multiple different laser heights currently set. The multiple laser heights set for the next focusing round can be determined based on the analysis results of this focusing round, reducing the total number of laser height settings when focusing is completed, thereby achieving the best search effect with the fewest number of measurements.

[0071] The laser focusing method provided by this invention involves laser-engraving a laser spot at multiple different laser heights, measuring the spot diameter to find the laser height corresponding to the minimum average spot diameter, and then using this laser height as a basis to find multiple more laser heights for judgment until the difference between the diameters of two adjacent laser spots engraved at the laser height corresponding to the minimum average spot diameter meets the preset conditions for focusing. This method digitally reflects the laser's focusing status and can accurately locate the laser's focal height according to product requirements, replacing the method of human visual identification. This achieves accurate and efficient laser focusing, ensuring the stability and improvement of laser engraving process quality.

[0072] Figure 5This is a flowchart of another laser focusing method provided in an embodiment of the present invention, see reference. Figure 5 The focusing methods for lasers include:

[0073] S210, Obtain the current reference height and current height adjustment step of the laser.

[0074] S220. Starting from the current reference height, adjust the step size according to the current height to determine multiple different laser heights of the laser, wherein the multiple different laser heights include at least the current reference height, at least one first height higher than the current reference height, and at least one second height lower than the current reference height.

[0075] S230. At each laser height, control the laser to etch multiple light spots and determine the average diameter of the light spot corresponding to each laser height.

[0076] S240. Determine whether the laser height corresponding to the average diameter of the smallest spot meets the preset conditions for focusing. If yes, proceed to step S250; otherwise, proceed to step S260.

[0077] S250, Laser focusing is confirmed to be successful.

[0078] S260. Determine the relationship between the average diameter of the laser spot corresponding to different laser heights; if the laser height corresponding to the minimum average diameter of the laser spot is the minimum among multiple different laser heights, then proceed to step S2710; if the laser height corresponding to the minimum average diameter of the laser spot is the maximum among multiple different laser heights, then proceed to step S2720; if the laser height corresponding to the minimum average diameter of the laser spot is neither the maximum nor the minimum among multiple different laser heights, then proceed to step S2730.

[0079] S2710. Determine the current height adjustment step as the next height adjustment step, determine the difference between the minimum value among multiple different laser heights and (n-1) / 2 times the height adjustment step as the next reference height, and replace the next reference height and the next height adjustment step with the current reference height and the current height adjustment step respectively, and return to step S210.

[0080] S2720. Determine the current height adjustment step as the next height adjustment step. Determine the sum of the maximum value among multiple different laser heights and (n-1) / 2 times the height adjustment step as the next reference height. Replace the next reference height and the next height adjustment step with the current reference height and the current height adjustment step, respectively. Return to step S210.

[0081] S2730. Determine the laser height corresponding to the minimum average spot diameter as the next reference height. Determine the ratio of the difference between two laser heights adjacent to the laser height corresponding to the minimum average spot diameter to n-1 as the next height adjustment step. Replace the next reference height and the next height adjustment step with the current reference height and the current height adjustment step, respectively. Return to step S210.

[0082] The laser focusing method provided in this invention includes the following steps: determining the next reference height and the next height adjustment step distance based on the relationship between the average diameters of the laser spots corresponding to multiple different laser heights. These steps include: when the laser height corresponding to the minimum average diameter of the laser spot is the minimum among multiple different laser heights, determining the current height adjustment step distance as the next height adjustment step distance; and determining the difference between the minimum among multiple different laser heights and (n-1) / 2 times the height adjustment step distance as the next reference height. In the case of the maximum value, the current height adjustment step is determined as the next height adjustment step, and the sum of the maximum value among multiple different laser heights and (n-1) / 2 times the height adjustment step is determined as the next reference height; in the case where the laser height corresponding to the minimum average spot diameter is neither the maximum nor the minimum value among multiple different laser heights, the laser height corresponding to the minimum average spot diameter is determined as the next reference height, and the ratio of the difference between two laser heights adjacent to the laser height corresponding to the minimum average spot diameter to (n-1) is determined as the next height adjustment step. Here, n is an odd number greater than 3, and n is the number of multiple different laser heights, with the number of first heights equal to the number of second heights. The technical solution provided by this embodiment of the invention, based on the size relationship of the average spot diameters corresponding to multiple different laser heights, can determine the direction of the correct focal length, so that the laser height is automatically "pulled" to the correct area in the next measurement, avoiding invalid measurements in the wrong area. Furthermore, by determining multiple laser height settings for the next operation based on the analysis results of this focusing, the total number of laser height settings can be reduced, achieving the best search effect with the fewest number of measurements.

[0083] For example, taking the current reference height as the initial laser height and the current height adjustment step as the initial height adjustment step, with 10 laser spots laser-engraved at each laser height, and n equal to 7, we will explain this using two rounds of focusing. During the first round of focusing:

[0084] Adjust the laser height to the initial reference height H, and control the laser to engrave 10 spots, namely spot HD1, spot HD2, spot HD3, spot HD4, spot HD5, spot HD6, spot HD7, spot HD8, spot HD9, and spot HD10; measure the diameter of spot HD1 to spot HD10, and calculate the average diameter HD of the 10 spots;

[0085] Adjust the laser height to H+D (the first initial height), where D is the initial height adjustment step; control the laser to engrave 10 spots, namely spot HE1, spot HE2, spot HE3, spot HE4, spot HE5, spot HE6, spot HE7, spot HE8, spot HE9, and spot HE10; measure the diameter of spots HE1 to HE10, and calculate the average diameter HE of the 10 spots;

[0086] Adjust the laser height to H+2D (the second first height), and control the laser to engrave 10 spots, namely spot HF1, spot HF2, spot HF3, spot HF4, spot HF5, spot HF6, spot HF7, spot HF8, spot HF9, and spot HF10; measure the diameter of spot HF1 to spot HF10, and calculate the average diameter HF of the 10 spots;

[0087] Adjust the laser height to H+3D (the third first height), and control the laser to engrave 10 spots, namely spots HG1, HG2, HG3, HG4, HG5, HG6, HG7, HG8, HG9, and HG10; measure the diameter of spots HG1 to HG10, and calculate the average diameter HG of the 10 spots;

[0088] Adjust the laser height to height HD (first and second heights); control the laser to engrave 10 spots, namely spot HC1, spot HC2, spot HC3, spot HC4, spot HC5, spot HC6, spot HC7, spot HC8, spot HC9, and spot HC10; measure the diameter of spot HC1 to spot HC10, and calculate the average diameter HC of the 10 spots;

[0089] Adjust the laser height to H-2D (second second height), and control the laser to engrave 10 spots, namely spot HB1, spot HB2, spot HB3, spot HB4, spot HB5, spot HB6, spot HB7, spot HB8, spot HB9, and spot HB10; measure the diameter of spot HB1 to spot HB10, and calculate the average diameter HB of the 10 spots;

[0090] Adjust the laser height to H-3D (the third second height), control the laser to engrave 10 light spots, namely light spot HA1, light spot HA2, light spot HA3, light spot HA4, light spot HA5, light spot HA6, light spot HA7, light spot HA8, light spot HA9, light spot HA10; measure the diameters of light spots HA1 to HA10, and calculate the average light spot diameter HA of these 10 light spots.

[0091] After analyzing the size relationships of the average light spot diameters corresponding to multiple different laser heights, there are three situations for the laser height corresponding to the minimum average light spot diameter among the set multiple different laser heights, namely: the laser height corresponding to the minimum average light spot diameter is the minimum value among the multiple different laser heights, the laser height corresponding to the minimum average light spot diameter is the maximum value among the multiple different laser heights, and the laser height corresponding to the minimum average light spot diameter is neither the maximum value nor the minimum value among the multiple different laser heights. In different situations, the setting methods for the laser height in the next focusing process are different.

[0092] As Figure 6 shown, if the size relationship of the measured average light spot diameters is: HA>HB>HC>HD<HE<HF<HG, the average light spot diameter HD is the minimum value, and the laser height corresponding to the average light spot diameter HD is the initial reference height H, then the corresponding situation is that the laser height corresponding to the minimum average light spot diameter is neither the maximum value nor the minimum value among the multiple different laser heights. Divide the difference between the laser heights H-D and H+D corresponding to HC and HE into 6 equal parts, each part with a height of D1, determine D1 as the next height adjustment step, and the laser height H corresponding to the average light spot diameter HD as the next reference height, named H1. In the second round of focusing process:

[0093] Since the laser height H1 and the laser height H are the same, the average light spot diameter HD of light spots HD1, HD2, HD3, HD4, HD5, HD6, HD7, HD8, HD9, HD10 is carried over as the average light spot diameter H1D for the next round of focusing;

[0094] Adjust the laser height of the laser to H1+D1 (the first first height of the second round of focusing), control the laser to engrave 10 light spots, namely light spot H1E1, light spot H1E2, light spot H1E3, light spot H1E4, light spot H1E5, light spot H1E6, light spot H1E7, light spot H1E8, light spot H1E9, light spot H1E10; measure the diameters of light spots H1E1 to H1E10, and calculate the average light spot diameter H1E of these 10 light spots.

[0095] Adjust the laser's beam height to H1+D2 (the second first height in the second round of focusing), and control the laser to etch 10 laser spots, namely spot H1F1, spot H1F2, spot H1F3, spot H1F4, spot H1F5, spot H1F6, spot H1F7, spot H1F8, spot H1F9, and spot H1F10; measure the diameter of spot H1F1 to spot H1F10, and calculate the average diameter H1F of the 10 spots;

[0096] Adjust the laser's laser height to H1+D3 (the third first height in the second round of focusing), and control the laser to etch 10 laser spots, namely spot H1G1, spot H1G2, spot H1G3, spot H1G4, spot H1G5, spot H1G6, spot H1G7, spot H1G8, spot H1G9, and spot H1G10; measure the diameter of spot H1G1 to spot H1G10, and calculate the average diameter H1G of the 10 spots;

[0097] Adjust the laser's beam height to H1-D1 (the first second height in the second round of focusing), and control the laser to etch 10 laser spots, namely spot H1C1, spot H1C2, spot H1C3, spot H1C4, spot H1C5, spot H1C6, spot H1C7, spot H1C8, spot H1C9, and spot H1C10; measure the diameter of spots H1C1 to H1C10, and calculate the average diameter H1C of the 10 spots;

[0098] Adjust the laser's beam height to H1-D2 (the second height in the second round of focusing), and control the laser to etch 10 laser spots, namely spot H1B1, spot H1B2, spot H1B3, spot H1B4, spot H1B5, spot H1B6, spot H1B7, spot H1B8, spot H1B9, and spot H1B10; measure the diameter of spot H1B1 to spot H1B10, and calculate the average diameter H1B of the 10 spots;

[0099] Adjust the laser's beam height to H1-D3 (the third second height in the second round of focusing), and control the laser to etch 10 laser spots, namely spot H1A1, spot H1A2, spot H1A3, spot H1A4, spot H1A5, spot H1A6, spot H1A7, spot H1A8, spot H1A9, and spot H1A10; measure the diameter of spot H1A1 to spot H1A10, and calculate the average diameter H1A of the 10 spots;

[0100] Thus, the average spot diameters H1A~H1G corresponding to the 10 laser heights in the second focusing process are obtained.

[0101] As Figure 7 shown, if the magnitude relationship of the average value of the measured spot diameters is: HA < HB < HC < HD < HE < HF < HG, where the average spot diameter HA is the minimum value, and the laser height corresponding to the average spot diameter HA is the height H - 3D, then the corresponding situation is that the laser height corresponding to the minimum average spot diameter is the minimum value among multiple different laser heights. Determine the height H - 6D as the next reference height H1, and determine the height D as the next height adjustment step. During the second round of focusing:

[0102] Adjust the laser height of the laser to H1, and control the laser to engrave 10 spots, namely spot H1D1, spot H1D2, spot H1D3, spot H1D4, spot H1D5, spot H1D6, spot H1D7, spot H1D8, spot H1D9, spot H1D10; measure the diameters of spots H1D1 to H1D10, and calculate the average spot diameter H1D of these 10 spots;

[0103] Adjust the laser height of the laser to H1 + D (the first first height in the second round of focusing), and control the laser to engrave 10 spots, namely spot H1E1, spot H1E2, spot H1E3, spot H1E4, spot H1E5, spot H1E6, spot H1E7, spot H1E8, spot H1E9, spot H1E10; measure the diameters of spots H1E1 to H1E10, and calculate the average spot diameter H1E of these 10 spots;

[0104] Adjust the laser height of the laser to H1 + 2D (the second first height in the second round of focusing), and control the laser to engrave 10 spots, namely spot H1F1, spot H1F2, spot H1F3, spot H1F4, spot H1F5, spot H1F6, spot H1F7, spot H1F8, spot H1F9, spot H1F10; measure the diameters of spots H1F1 to H1F10, and calculate the average spot diameter H1F of these 10 spots;

[0105] Since the laser height H1 + 3D (the third first height in the second round of focusing) is the same as the laser height H - 3D, the average spot diameter HA of spots HA1, HA2, HA3, HA4, HA5, HA6, HA7, HA8, HA9, HA10 is carried over and used as the average spot diameter H1G in the second round of focusing;

[0106] Adjust the laser's beam height to H1-D (the first second height in the second round of focusing), and control the laser to etch 10 laser spots, namely spot H1C1, spot H1C2, spot H1C3, spot H1C4, spot H1C5, spot H1C6, spot H1C7, spot H1C8, spot H1C9, and spot H1C10; measure the diameter of spot H1C1 to spot H1C10, and calculate the average diameter H1C of the 10 spots;

[0107] Adjust the laser's beam height to H1-2D (the second height in the second round of focusing), and control the laser to etch 10 laser spots, namely spot H1B1, spot H1B2, spot H1B3, spot H1B4, spot H1B5, spot H1B6, spot H1B7, spot H1B8, spot H1B9, and spot H1B10; measure the diameter of spots H1B1 to H1B10, and calculate the average diameter H1B of the 10 spots;

[0108] Adjust the laser's laser height to H1-3D (the third second height in the second round of focusing), and control the laser to etch 10 laser spots, namely spot H1A1, spot H1A2, spot H1A3, spot H1A4, spot H1A5, spot H1A6, spot H1A7, spot H1A8, spot H1A9, and spot H1A10; measure the diameter of spot H1A1 to spot H1A10, and calculate the average diameter H1A of the 10 spots;

[0109] Thus, the average spot diameters H1A~H1G corresponding to the 10 laser heights in the second focusing process are obtained.

[0110] like Figure 8 As shown, if the average measured spot diameters are in the following order: HA > HB > HC > HD > HE > HF > HG, and the average spot diameter HG is the minimum, then the laser height corresponding to the average spot diameter HG is height H+3D. This means the laser height corresponding to the minimum average spot diameter is the maximum of several different laser heights. Height H+6D is determined as the next reference height H1, and height D is determined as the next height adjustment step. During the second round of focusing:

[0111] The laser beam height is adjusted to H1, and the laser is controlled to etch 10 laser spots, namely H1D1, H1D2, H1D3, H1D4, H1D5, H1D6, H1D7, H1D8, H1D9, and H1D10. The diameters of spots H1D1 to H1D10 are measured, and the average diameter H1D of the 10 spots is calculated.

[0112] Adjust the laser's beam height to H1+D (the first height in the second round of focusing), and control the laser to etch 10 laser spots, namely spot H1E1, spot H1E2, spot H1E3, spot H1E4, spot H1E5, spot H1E6, spot H1E7, spot H1E8, spot H1E9, and spot H1E10; measure the diameter of spot H1E1 to spot H1E10, and calculate the average diameter H1E of the 10 spots;

[0113] Adjust the laser's beam height to H1+2D (the second first height in the second round of focusing), and control the laser to etch 10 laser spots, namely spot H1F1, spot H1F2, spot H1F3, spot H1F4, spot H1F5, spot H1F6, spot H1F7, spot H1F8, spot H1F9, and spot H1F10; measure the diameter of spot H1F1 to spot H1F10, and calculate the average diameter H1F of the 10 spots;

[0114] Adjust the laser's beam height to H1+3D (the third first height in the second round of focusing), and control the laser to etch 10 laser spots, namely spot H1G1, spot H1G2, spot H1G3, spot H1G4, spot H1G5, spot H1G6, spot H1G7, spot H1G8, spot H1G9, and spot H1G10; measure the diameter of spot H1G1 to spot H1G10, and calculate the average diameter H1G of the 10 spots;

[0115] Adjust the laser's beam height to H1-D (the first second height in the second round of focusing), and control the laser to etch 10 laser spots, namely spot H1C1, spot H1C2, spot H1C3, spot H1C4, spot H1C5, spot H1C6, spot H1C7, spot H1C8, spot H1C9, and spot H1C10; measure the diameter of spot H1C1 to spot H1C10, and calculate the average diameter H1C of the 10 spots;

[0116] Adjust the laser's beam height to H1-2D (the second height in the second round of focusing), and control the laser to etch 10 laser spots, namely spot H1B1, spot H1B2, spot H1B3, spot H1B4, spot H1B5, spot H1B6, spot H1B7, spot H1B8, spot H1B9, and spot H1B10; measure the diameter of spots H1B1 to H1B10, and calculate the average diameter H1B of the 10 spots;

[0117] Since the laser height H1-3D (the third second height in the second round of focusing) and the laser height H+3D are the same, the average spot diameter HG of the spot HG1, HG2, HG3, HG4, HG5, HG6, HG7, HG8, HG9, and HG10 is used as the average spot diameter H1A of the second round of focusing;

[0118] Thus, the average spot diameters H1A~H1G corresponding to the 10 laser heights in the second focusing process are obtained.

[0119] In each of the above scenarios, after obtaining the average spot diameters H1A~H1G corresponding to the 10 laser heights in the second focusing process, it is determined whether the laser height corresponding to the smallest average spot diameter in the second focusing process meets the preset focusing conditions. If it does, the smallest spot in the second focusing process is the target spot, and the laser height corresponding to the smallest average spot diameter in the second focusing process is determined as the target laser height, thus completing laser focusing. If it does not meet the conditions, based on the relationship between the average spot diameters obtained in the second focusing process and the reference height and height adjustment step used in the second round, the reference height and height adjustment step for the third round are determined, and the third round of focusing is performed. The above steps are repeated until the laser height corresponding to the minimum value of the average spot diameters HnA, HnB, HnC, HnD, HnE, HnF, and HnG obtained in the (n+1)th focusing round meets the laser requirements of the product to be laser-focused; n is a natural number.

[0120] Figure 9 This is a flowchart of another laser focusing method provided in an embodiment of the present invention, see reference. Figure 9 The focusing methods for lasers include:

[0121] S310: Obtain the current reference height and current height adjustment step of the laser.

[0122] S320. Starting from the current reference height, adjust the step size according to the current height to determine multiple different laser heights of the laser, wherein the multiple different laser heights include at least the current reference height, at least one first height higher than the current reference height, and at least one second height lower than the current reference height.

[0123] S330: At each laser height, control the laser to etch multiple light spots.

[0124] S340. Measure the diameter of multiple laser spots laser-etched at each laser height using an optical image measuring instrument.

[0125] S350. Calculate the average diameter of multiple laser spots at each laser height to obtain the average diameter of the laser spot corresponding to each laser height.

[0126] S360. Determine whether the difference between the diameters of two adjacent laser spots corresponding to the laser height corresponding to the minimum average diameter of the laser spot is less than or equal to the maximum allowable deviation of the laser engraving information line width. If yes, proceed to step S370; otherwise, proceed to step S380.

[0127] S370. Determine that the difference between the diameters of two adjacent laser spots engraved by the laser height corresponding to the minimum average diameter of the laser spot meets the preset conditions for successful focusing, and confirm that the laser is successfully focused.

[0128] S380. Determine that the difference between the diameters of two adjacent laser spots laser-etched by the laser height corresponding to the minimum average laser spot diameter does not meet the preset conditions for focusing qualification, and determine the size relationship of the average laser spot diameters corresponding to different laser heights; if the laser height corresponding to the minimum average laser spot diameter is the minimum value among multiple different laser heights, then proceed to step S3910; if the laser height corresponding to the minimum average laser spot diameter is the maximum value among multiple different laser heights, then proceed to step S3920; if the laser height corresponding to the minimum average laser spot diameter is neither the maximum nor the minimum value among multiple different laser heights, then proceed to step S3930.

[0129] S3910. Determine the current height adjustment step as the next height adjustment step, determine the difference between the minimum value among multiple different laser heights and (n-1) / 2 times the height adjustment step as the next reference height, and replace the next reference height and the next height adjustment step with the current reference height and the current height adjustment step, respectively, and return to step S310.

[0130] S3920. Determine the current height adjustment step as the next height adjustment step. Determine the sum of the maximum value among multiple different laser heights and (n-1) / 2 times the height adjustment step as the next reference height. Replace the next reference height and the next height adjustment step with the current reference height and the current height adjustment step, respectively. Return to step S310.

[0131] S3930. Determine the laser height corresponding to the minimum average spot diameter as the next reference height. Determine the ratio of the difference between two laser heights adjacent to the laser height corresponding to the minimum average spot diameter to (n-1) as the next height adjustment step. Replace the next reference height and the next height adjustment step with the current reference height and the current height adjustment step, respectively. Return to step S310.

[0132] In the laser focusing method provided in this embodiment of the invention, the step of determining the average diameter of the laser spot corresponding to each laser height includes: measuring the diameter of multiple laser spots laser-etched at each laser height using an optical image measuring instrument; and calculating the average diameter of the multiple laser spots at each laser height to obtain the average diameter of the laser spot corresponding to each laser height. The optical image measuring instrument can acquire laser spot images and obtain laser spot diameter information based on the laser spot images, thereby achieving high efficiency in measuring the laser spot diameter.

[0133] Furthermore, the step of determining whether the difference between the diameters of two adjacent laser spots etched by the laser height corresponding to the minimum average spot diameter meets the preset conditions for focusing includes: judging whether the difference between the diameters of two adjacent laser spots etched by the laser height corresponding to the minimum average spot diameter is less than or equal to the maximum allowable deviation of the laser engraving information linewidth; if so, then the laser height corresponding to the minimum average spot diameter meets the preset conditions for focusing; if not, then the laser height corresponding to the minimum average spot diameter does not meet the preset conditions for focusing. Since the spot diameter is affected by the laser power during laser engraving and by the text input method, it is difficult to determine the spot diameter that meets the focusing requirements or the range of spot diameters that meets the focusing requirements. This embodiment of the invention, by judging whether the difference between the diameters of two adjacent laser spots etched by the laser height corresponding to the minimum average spot diameter is less than or equal to the maximum allowable deviation of the laser engraving information linewidth, facilitates the definition of preset conditions for focusing that meet the product laser engraving requirements.

[0134] Furthermore, before determining whether the laser-etched spot corresponding to the laser height with the minimum average spot diameter is less than or equal to the maximum allowable deviation of the laser-etched information linewidth, the following steps are also included:

[0135] The maximum permissible deviation of the laser engraving line width is determined based on the maximum permissible line width and the minimum permissible line width of the laser engraving information.

[0136] Specifically, laser engraving information is generated by filling in many laser lines. These lines are formed by connecting laser spots, and the difference in diameter between adjacent spots should be less than or equal to the maximum permissible deviation (SPEC) for the laser engraving line width. Taking the laser engraving of the letter "I" as an example, refer to... Figure 10 W1 is the minimum allowable line width of the letter "I" pattern, W2 is the maximum allowable line width of the letter "I" pattern, and SPEC = (W2 - W1) / 2.

[0137] Based on the above embodiments, optionally, the focusing method of the laser also includes: obtaining the focal length range of the laser; and determining the initial reference height and initial height adjustment step of the laser based on the focal length range of the laser.

[0138] Specifically, the steps for determining the initial reference height and initial height adjustment step of the laser based on its focal length range include: determining the initial reference height of the laser based on the median value of the laser's focal length range; and determining the initial height adjustment step based on the laser's focal length range and the preset number of different laser heights. The median value of the focal length range is equal to half the sum of the minimum and maximum distances within the focal length range. The focal length range varies between different brands and models of lasers; it is usually included in the laser's manufacturer information. Alternatively, the focal length range can be obtained through measurement. The steps for measuring the laser's focal length range may include: controlling the laser to emit light at its rated power and projecting it onto a metal plate; moving the metal plate up and down to adjust the distance between the metal plate and the laser, determining the range of distances from the metal plate to the laser that allows continuous light to appear on the plate (moving the metal plate up and down should result in no light on the plate in the upper distance range, light on the plate in the middle distance range, and no light on the plate in the lower distance range), and defining this range as the laser's focal length range.

[0139] Based on the above embodiments, optionally, at each laser height, the laser is controlled to etch multiple laser spots, including:

[0140] At each laser height, the laser is controlled to laser-etch multiple sequentially spaced spots onto the same surface to be laser-etched, so that the multiple spots laser-etched at different laser heights form a spot matrix on the same surface to be laser-etched (e.g., ...). Figures 6-8 This allows the optical image measuring instrument to acquire a matrix image of the laser spot, making it easy to measure the diameter of multiple laser spots at each laser height with a single photograph, thus reducing the number of photographs required.

[0141] refer to Figure 11 The present invention also provides a laser focusing control device for executing the laser focusing method described in any embodiment of the present invention, including:

[0142] The height and step size acquisition module 10 is used to acquire the current reference height and current height adjustment step size of the laser.

[0143] The laser height determination module 20 is used to determine multiple different laser heights of the laser by adjusting the step size based on the current reference height as the starting point. The multiple different laser heights include at least the current reference height, at least one first height higher than the current reference height, and at least one second height lower than the current reference height.

[0144] The control module 30 is used to control the laser to engrave multiple light spots at each laser height;

[0145] The average diameter determination module 40 is used to determine the average diameter of the laser spot corresponding to each laser height.

[0146] The focus judgment module 50 is used to determine whether the laser height corresponding to the minimum average diameter of the light spot meets the preset conditions for qualified focus.

[0147] The height and step size adjustment module 60 is used to determine the next reference height and the next height adjustment step size based on the relationship between the average diameter of the spot corresponding to multiple different laser heights when the conditions are not met, and to replace the next reference height and the next height adjustment step size with the current reference height and the current height adjustment step size respectively.

[0148] The laser focusing control device provided in the embodiments of the present invention can execute the laser focusing control method provided in any embodiment of the present invention, and has the corresponding functional modules and beneficial effects of the method.

[0149] This invention also provides a laser engraving device, including a laser and a focusing control device for the laser as described in any embodiment of this invention, which has corresponding beneficial effects, which will not be elaborated here.

[0150] 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 focusing method for a laser, characterized in that, include: Obtain the laser's current reference height and current height adjustment step size; Starting from the current reference height, the step size is adjusted according to the current height to determine multiple different laser heights of the laser. The multiple different laser heights include at least the current reference height, at least one first height higher than the current reference height, and at least one second height lower than the current reference height. At each laser height, the laser is controlled to etch multiple light spots, and the average diameter of the light spot corresponding to each laser height is determined; Determine whether the laser height corresponding to the minimum average spot diameter meets the preset conditions for focusing qualification. If the conditions are not met, the next reference height and the next height adjustment step are determined based on the relationship between the average diameter of the light spots corresponding to the multiple different laser heights. The next reference height and the next height adjustment step are then replaced with the current reference height and the current height adjustment step, and the above steps are repeated until the laser height corresponding to the smallest average diameter of the light spot meets the preset conditions for focusing. The step of determining the next reference height and the next height adjustment step distance based on the relationship between the average diameters of the laser spots corresponding to the multiple different laser heights includes: When the laser height corresponding to the minimum average diameter of the laser spot is the minimum among the plurality of different laser heights, the current height adjustment step is determined as the next height adjustment step, and the difference between the minimum among the plurality of different laser heights and (n-1) / 2 times the height adjustment step is determined as the next reference height. When the laser height corresponding to the minimum average laser spot diameter is the maximum value among the plurality of different laser heights, the current height adjustment step is determined as the next height adjustment step, and the sum of the maximum value among the plurality of different laser heights and (n-1) / 2 times the height adjustment step is determined as the next reference height; When the laser height corresponding to the minimum average laser diameter is neither the maximum nor the minimum among the plurality of different laser heights, the laser height corresponding to the minimum average laser diameter is determined as the next reference height, and the ratio of the difference between two laser heights adjacent to the laser height corresponding to the minimum average laser diameter to (n-1) is determined as the next height adjustment step. Where n is an odd number greater than 3, and n is the number of the plurality of different laser heights.

2. The focusing method for a laser according to claim 1, characterized in that, Determine the average spot diameter corresponding to each laser height, including: The diameter of the multiple laser spots laser-etched at each laser height is measured using an optical image measuring instrument. Calculate the average diameter of the plurality of laser spots at each laser height to obtain the average diameter of the laser spot corresponding to each laser height.

3. The focusing method for a laser according to claim 1, characterized in that, The determination of whether the laser height corresponding to the minimum average spot diameter meets the preset conditions for focusing qualification includes: Determine whether the difference between the diameters of two adjacent laser spots etched by the laser height corresponding to the minimum average diameter of the laser spot is less than or equal to the maximum allowable deviation of the laser engraving information line width; If so, then determine that the laser height corresponding to the minimum average spot diameter meets the preset conditions for focusing qualification; If not, then the laser height corresponding to the minimum average spot diameter does not meet the preset conditions for focusing.

4. The focusing method for a laser according to claim 3, characterized in that, Before determining whether the difference between the diameters of two adjacent laser spots engraved by the laser height corresponding to the minimum average diameter of the laser spot is less than or equal to the maximum allowable deviation of the laser engraving information line width, the process also includes: The maximum permissible deviation of the laser engraving line width is determined based on the maximum permissible line width and the minimum permissible line width of the laser engraving information.

5. The focusing method for a laser according to claim 1, characterized in that, Also includes: Obtain the focal length range of the laser; Based on the focal length range of the laser, determine the initial reference height and the initial height adjustment step size of the laser.

6. The focusing method for a laser according to claim 5, characterized in that, The step of determining the initial reference height and initial height adjustment step distance of the laser based on the focal length range of the laser includes: The initial reference height of the laser is determined based on the median value of the focal length range of the laser. The initial height adjustment step is determined based on the focal length range of the laser and the preset number of the plurality of different laser heights.

7. The focusing method for a laser according to claim 1, characterized in that, At each laser height, controlling the laser to etch multiple laser spots includes: At each laser height, the laser is controlled to laser-etch multiple light spots arranged in sequence at intervals on the same surface to be laser-etched, so that the multiple light spots lasered at different laser heights form a light spot matrix on the same surface to be laser-etched.

8. A focusing control device for a laser, characterized in that, A focusing method for performing any one of the lasers according to claims 1 to 7, comprising: The height and step size acquisition module is used to acquire the current reference height and current height adjustment step size of the laser. A laser height determination module is used to determine multiple different laser heights of the laser by adjusting the step size according to the current reference height, starting from the current reference height. The multiple different laser heights include at least the current reference height, at least one first height higher than the current reference height, and at least one second height lower than the current reference height. The control module is used to control the laser to engrave multiple light spots at each laser height; The average diameter determination module is used to determine the average diameter of the laser spot corresponding to each laser height; The focus judgment module is used to determine whether the laser height corresponding to the minimum average diameter of the light spot meets the preset conditions for focus qualification. The height and step size adjustment module is used to determine the next reference height and the next height adjustment step size based on the relationship between the average diameter of the spot corresponding to the multiple different laser heights when the conditions are not met, and to replace the next reference height and the next height adjustment step size with the current reference height and the current height adjustment step size, respectively.

9. A laser engraving device, characterized in that, Includes a laser and a focusing control device for the laser as described in claim 8.

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