Positioning method for laser processing and laser processing equipment
By scanning and acquiring the reflected light intensity variation curve in the laser processing equipment, and adjusting the parallel and focused positions, the problem of inaccurate positioning of curved workpieces is solved, and high-precision laser processing is achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-28
- Publication Date
- 2026-03-31
AI Technical Summary
In existing technologies, judging the laser incident position by the magnitude of the reflected light intensity is inaccurate, especially when machining curved workpieces, which leads to inaccurate positioning and affects machining accuracy.
By scanning the surface to be processed in the first and second directions with a calibration beam, the intensity variation curve of the reflected beam is obtained. Based on these signal curves, the parallel and focusing positions are adjusted. By using the synchronous movement of the galvanometer group and the focusing element, the laser beam is ensured to be perpendicularly incident and converged at the ideal processing starting point.
It improves the positioning accuracy of laser processing, ensures that the laser scanning path matches the preset path, reduces processing errors, and improves processing quality.
Smart Images
Figure CN121755867A_ABST
Abstract
Description
Technical Field
[0001] This application belongs to the field of laser processing technology, and relates to a curved surface laser processing technology, and in particular to a laser processing positioning method and laser processing equipment. Background Technology
[0002] Laser scanning processing is a manufacturing technology that uses a high-speed laser beam to mark, cut, and perform other processing on workpieces based on a preset scanning path. It features high processing speed and high precision, and the processing does not require direct contact with the workpiece, thus avoiding mechanical wear. It has important application value in manufacturing scenarios that require micro-machining, complex structure processing, and high-quality surface treatment, such as electronic semiconductors, aerospace, and medical devices.
[0003] To ensure processing quality, positioning is typically required before laser processing begins to determine the starting point and ensure that the actual laser scanning path strictly matches the preset ideal scanning path, preventing pattern deviation. Current technology usually uses the intensity of the light reflected from the workpiece surface by a calibration beam coaxial with the processing laser beam to determine if the current laser incident position is the ideal starting point (modified). However, due to the influence of various factors such as the workpiece surface, image sensor status, and environment, the light intensity received by the image sensor itself fluctuates. Judging the workpiece position based solely on a single light intensity value is inaccurate, leading to inaccurate workpiece positioning. This is especially true for processing curved workpieces, where the surface has undulations, making the processing path more complex. Even slight deviations can cause significant processing errors. Therefore, precise positioning is necessary before processing. Positioning based solely on the current light intensity value received by the image sensor cannot meet the requirements for processing curved workpieces. Summary of the Invention
[0004] This application provides a positioning method and laser processing equipment for laser processing, which solves the problem in the prior art that, because the intensity of reflected light is affected by a variety of factors, judging whether the current laser incident position is the ideal processing starting point solely by the magnitude of the intensity of reflected light results in a large error.
[0005] In a first aspect, this application provides a positioning method for laser processing, applied to a laser processing equipment, comprising: initially positioning a workpiece to be processed; emitting a calibration beam, wherein the calibration beam is incident on the surface to be processed of the workpiece and reflected as a reflected beam; scanning the surface to be processed in a first direction through the calibration beam to obtain the intensity change of the reflected beam as a first parallel signal curve; and scanning the surface to be processed in a second direction through the calibration beam to obtain the intensity change of the reflected beam as a second parallel signal curve; adjusting the parallel position of the laser processing equipment based on the first parallel signal curve and the second parallel signal curve; periodically moving the focusing position of the calibration beam in the vertical direction of the support platform, and obtaining a focusing signal curve through the signal receiving unit; and adjusting the focusing position of the laser processing equipment based on the focusing signal curve.
[0006] In one embodiment of this application, adjusting the parallel position of the laser processing equipment based on the first parallel signal curve and the second parallel signal curve includes: obtaining the maximum value positions of the first parallel signal curve and the second parallel signal curve respectively; adjusting the first parallel position of the laser processing equipment based on the maximum value position of the first parallel signal curve; and adjusting the second parallel position of the laser processing equipment based on the maximum value position of the second parallel signal curve.
[0007] In one embodiment of this application, the laser processing equipment scans using a galvanometer group and focuses using a focusing element; the positions of the galvanometer group and the focusing element are simultaneously adjusted to perform a first parallel position adjustment and a second parallel position adjustment on the laser processing equipment.
[0008] In one embodiment of this application, adjusting the focus position of the laser processing equipment based on the focus signal curve includes: extracting a single-cycle sub-signal curve based on the focus signal curve, obtaining any maximum point of the single-cycle sub-signal curve, and adjusting the focus position of the laser processing equipment based on the maximum point; wherein, the single-cycle sub-signal curve is the curve portion on the focus signal curve corresponding to the point where the focus position of the calibration beam moves one cycle in the vertical direction of the support platform.
[0009] In one embodiment of this application, the laser processing equipment changes the focus position through a focusing unit; the position of the focusing unit corresponding to any maximum point of the single-cycle sub-signal curve is obtained to adjust the focus position of the laser processing equipment.
[0010] Secondly, this application provides a laser processing device, including a laser source and a focusing unit, a galvanometer group, and a focusing element sequentially disposed on the propagation optical path of the laser beam emitted by the laser source; the focusing unit is used to expand the laser beam and adjust the focusing position of the expanded laser beam; the galvanometer group is used to adjust the position and angle at which the laser beam is incident on the surface to be processed; the focusing element is used to focus the laser beam on the surface to be processed; the laser beam is reflected after incident on the surface to be processed to form a reflected beam; a reflecting element is also disposed on the optical path between the focusing unit and the laser source, the reflecting element being used to reflect the reflected beam to a signal receiving unit; the signal receiving unit is used to acquire the intensity change of the reflected beam.
[0011] In one embodiment of this application, the laser beam emitted by the laser source is a calibration beam or a processing beam; when the laser source emits the calibration beam, the operating power is a preset first power; when the laser source emits the processing beam, the operating power is a preset second power; the first power is lower than the second power.
[0012] In one embodiment of this application, the focusing unit includes at least one movable lens, which moves within a preset moving range to change the focusing position of the laser beam; when the laser source emits the calibration beam, the movable lens is periodically moved to obtain a focusing signal curve; a single-cycle sub-signal curve is extracted based on the focusing signal curve, and any maximum point of the single-cycle sub-signal curve is obtained; based on the maximum point, the movable lens is moved to the corresponding position to adjust the focusing position, and the moving range is updated based on the position of the movable lens after the movement.
[0013] In one embodiment of this application, when the laser source emits the calibration beam, the galvanometer group and the focusing element are moved synchronously in a first direction so that the calibration beam scans the surface to be processed in the first direction; and the galvanometer group and the focusing element are moved synchronously in a second direction so that the calibration beam scans the surface to be processed in the second direction; when the laser source emits the processing beam, the galvanometer group is rotated so that the processing beam scans the surface to be processed.
[0014] In one embodiment of this application, the signal receiving unit includes a signal receiving focusing element, an aperture, and a light signal intensity sensor arranged sequentially along the propagation optical path of the reflected beam; the aperture is located at the focal point of the signal receiving focusing element.
[0015] As described above, the laser processing positioning method and laser processing equipment described in this application obtain a first parallel signal curve and a second parallel signal curve to adjust the parallel position based on the first parallel signal curve and the second parallel signal curve, and obtain a focus signal curve to adjust the focus position based on the focus signal curve. This avoids the error caused by adjusting the positioning solely by the magnitude of the light intensity value, and has high positioning accuracy, thereby achieving better laser processing results and having high industrial application value. Attached Figure Description
[0016] Figure 1 The diagram shown is a schematic of an optical path structure for laser scanning processing in the prior art.
[0017] Figure 2 This diagram illustrates an ideal starting point for machining a surface to be processed, as described in an embodiment of this application.
[0018] Figure 3 The diagram shown is a schematic diagram of the optical path structure of a laser processing device according to an embodiment of this application.
[0019] Figure 4 The diagram shown is a structural schematic of a focusing unit according to an embodiment of this application.
[0020] Figure 5 The diagram shown is a structural schematic of a galvanometer assembly according to an embodiment of this application.
[0021] Figure 6 The diagram shown is a flowchart illustrating a positioning method according to an embodiment of this application.
[0022] Figure 7 The diagram shown is a flowchart illustrating another positioning method described in an embodiment of this application.
[0023] Figure 8 This diagram illustrates the parallel position adjustment of a calibration beam as described in an embodiment of this application.
[0024] Figure 9 The diagram shows a process flow diagram of a laser processing device for parallel position adjustment as described in an embodiment of this application.
[0025] Figure 10 The diagram shown is a schematic diagram of a first parallel signal curve and a second parallel signal curve as described in an embodiment of this application.
[0026] Figure 11 The diagram shows the focusing position adjustment of a calibration beam as described in an embodiment of this application.
[0027] Figure 12 The image shown is a schematic diagram of a focusing signal curve as described in an embodiment of this application.
[0028] Explanation of reference numerals in the attached figures
[0029] 11: Laser source; 12: Focusing unit; 121: Movable lens; 122: Left lens position; 123: Right lens position; 13: Galvanometer group; 131: First galvanometer; 132: Second galvanometer; 133: Third galvanometer; 134: Fourth galvanometer; 14: Focusing element; 15: Workpiece to be processed; 16: Support platform; 17: Reflecting element; 18: Signal receiving unit; 181: Signal receiving focusing element; 182: Aperture; 183: Light signal intensity sensor. Detailed Implementation
[0030] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. This application can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be noted that, unless otherwise specified, the following embodiments and features in the embodiments can be combined with each other.
[0031] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this application. Therefore, the drawings only show the components related to this application and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.
[0032] Before laser processing begins, the relative positions of the laser beam and the workpiece must be determined so that the laser beam can be positioned according to the preset processing scanning path. Existing laser positioning methods often determine the processing position by measuring the intensity of the reflected light after the calibration beam is reflected from the surface of the workpiece, and then judging whether the calibration beam coincides with the position of the ideal processing beam. However, since the intensity of the reflected light is affected by many factors, positioning based solely on the numerical value of the intensity has significant errors, especially for the processing of curved workpieces, where the processing error is even more pronounced.
[0033] To address the technical problems existing in the prior art, the following embodiments of this application provide a positioning method and a laser processing device for laser processing. By scanning the surface to be processed with a calibration beam and changing the focusing position of the calibration beam, the intensity change curve of the reflected beam after the calibration beam is reflected by the surface to be processed is obtained. Based on the intensity change curve, the laser processing device is accurately positioned, thereby enabling high-precision laser scanning processing.
[0034] The following embodiments of this application provide a positioning method and laser processing equipment for laser processing, including but not limited to precise positioning of various curved or flat surfaces before laser processing. The following description will take a curved surface as an example.
[0035] like Figure 1 and Figure 2 As shown, to facilitate understanding by those skilled in the art, this embodiment exemplarily provides a schematic diagram of the positioning of a laser scanning processing optical path. For example... Figure 1 As shown, the laser scanning processing optical path includes: a laser source 11 and a focusing unit 12, a galvanometer group 13, a focusing element 14, and a workpiece 15 to be processed, which are sequentially arranged on the propagation optical path of the laser beam emitted by the laser source 11. The workpiece 15 is fixedly placed on a support platform 16. The laser beam emitted by the laser source 11 is expanded by the focusing unit 12 and reflected by the galvanometer group 13 before being focused by the focusing element 14 onto the surface to be processed on the workpiece 15. The galvanometer group 13 is rotated to make the laser beam scan based on a preset scanning path, thereby processing the surface to be processed on the workpiece 15.
[0036] To ensure that the actual laser scanning path strictly matches the preset ideal scanning path, it is necessary to determine the processing starting point of the laser beam. For example, such as... Figure 2 As shown, the workpiece 15 to be processed is a transparent element that comes into contact with the human eye during femtosecond laser corneal refractive surgery. The surface to be processed is the curved surface at its lower part. The ideal processing starting point is set as the vertex of the curved surface to be processed, that is, the point on the curved surface to be processed with the largest vertical distance from the surface of the support platform 16. Based on this, the laser processing positioning method provided in this embodiment is used to adjust the laser processing equipment so that when the adjusted laser processing equipment starts processing the curved surface, the emitted laser beam is perpendicularly incident on the curved surface to be processed and converges at the vertex of the surface of the curved surface to be processed.
[0037] It should be noted that the laser processing positioning method and laser processing equipment provided in the following embodiments of this application can also set the ideal processing starting point at other positions on the surface to be processed, including but not limited to the lowest point of the surface to be processed or the boundary point of the edge of the surface, etc. This application does not make specific limitations here.
[0038] The technical solutions in the embodiments of this application will be described in detail below with reference to the accompanying drawings.
[0039] This embodiment provides a laser processing device for laser processing of the curved surface of a workpiece 15. To improve the accuracy of laser processing, positioning is required before laser processing. Specifically, as... Figure 3As shown, the laser processing equipment includes a laser source 11, a focusing unit 12, a galvanometer group 13, a focusing element 14, a reflecting element 17, and a signal receiving unit 18. The laser source 11 is used to emit a laser beam, which passes through the focusing unit 12, the galvanometer group 13, and the focusing element 14 in sequence, and finally enters the surface to be processed of the workpiece 15.
[0040] It should be noted that the laser source 11 is used to emit a processing beam during laser processing and a calibration beam during positioning. This ensures that the calibration beam and the processing beam have the same wavelength, avoiding deviations caused by differences in the refractive index of different wavelengths of laser light or differences in the position and state of different laser sources, which could lead to positioning errors in the processing beam during actual processing. This further improves the positioning accuracy of the laser processing equipment. Furthermore, to prevent the calibration beam from damaging the surface to be processed during positioning, the operating power of the calibration beam is a preset first power, and the operating power of the processing beam is a preset second power, with the first power being lower than the second power. Specifically, those skilled in the art can set the magnitude of the second power according to the processing requirements and the material properties of the surface to be processed, and set the magnitude of the first power according to the material properties of the surface to be processed to avoid damage to the surface by the calibration beam. For example, the calibration beam is a pulsed laser with a single pulse energy of 0.2 μJ, a repetition rate of 500 kHz, a pulse width of 200 fs, and a spot diameter of 3-5 mm; the processing beam is a pulsed laser with a single pulse energy of 2 μJ, a repetition rate of 500 kHz, a pulse width of 200 fs, and a spot diameter of 3-5 mm. Of course, those skilled in the art should make specific settings for the calibration beam and the processing beam based on actual needs, and this embodiment does not impose specific limitations.
[0041] The focusing unit 12 is used to expand the laser beam and adjust the focusing position of the expanded laser beam. For example, as shown... Figure 4 As shown, the focusing unit 12 includes at least one movable lens 121. The movable lens 121 moves within a preset range to change the focusing position of the laser beam, thereby adjusting the focusing position of the laser processing equipment. Specifically, the laser beam is focused at the vertex of the surface to be processed.
[0042] The galvanometer group 13 is used to change the position and angle of the laser beam incident on the surface to be processed. Specifically, by adjusting the galvanometer group 13, the laser beam is made to scan the surface to be processed. It should be noted that when the laser beam is a calibration beam, i.e., when the laser processing equipment is positioning, scanning is achieved by moving each galvanometer in the galvanometer group, and ultimately the laser beam emitted by the laser processing equipment is perpendicularly incident on the vertex of the surface to be processed; when the laser beam is a processing beam, i.e., when the laser processing equipment is performing laser processing, scanning is achieved by rotating each galvanometer in the galvanometer group.
[0043] The focusing element 14 is used to focus the laser beam onto the surface to be processed. It should be noted that when the laser beam is a calibration beam, i.e., when the laser processing equipment is positioning itself, the focusing element 14 moves synchronously with the galvanometer assembly 13. Exemplarily, the focusing element 14 has a focusing lens assembly.
[0044] Furthermore, after the laser beam is incident on the surface to be processed, it is reflected, and the reflected beam propagates sequentially through the focusing element 14, the galvanometer group 13, and the adjustment unit 12. In order to obtain the light intensity of the reflected beam for positioning and adjustment of the laser processing equipment, this embodiment also includes a reflecting element 17 and a signal receiving unit 18. The reflecting element 17 is disposed in the optical path between the laser source 11 and the focusing unit 12, and is used to reflect the reflected beam after passing through the focusing unit 12 to the signal receiving unit 18. For example, the reflecting element 17 is a semi-transparent and semi-reflective element, such as a polarizing beam splitter, and the surface of the polarizing beam splitter near the focusing unit 12 is provided with a quarter-wave plate, or the semi-transparent and semi-reflective element is a semi-transparent and semi-reflective mirror placed at 45° to the direction of laser beam propagation; the signal receiving unit 18 is used to receive and record the light intensity changes of the reflected beam.
[0045] For example, the signal receiving unit 18 includes a signal receiving focusing element 181, an aperture 182, and a light signal intensity sensor 183. The reflected beam is reflected by the reflecting element 17 and then incident on the signal receiving focusing element 181 for focusing; the aperture 182 is an aperture of a preset size, located at the focal position of the signal receiving focusing element 181, to filter out stray light, thereby improving the accuracy of the final received light intensity; the light signal intensity sensor 183 is used to receive and record the light intensity of the reflected beam, so as to adjust the laser processing equipment based on the light intensity change of the reflected beam to achieve positioning.
[0046] Specifically, when the laser processing equipment is positioned, the galvanometer group 13 and the focusing element 14 are moved synchronously in the first and second directions, respectively, so that the calibration beam scans the surface to be processed in the first and second directions, respectively. When the calibration beam scans the surface to be processed in the first direction, the signal receiving unit 18 records the intensity change of the reflected beam to obtain a first parallel signal curve; when the calibration beam scans the surface to be processed in the second direction, the signal receiving unit 18 records the intensity change of the reflected beam to obtain a second parallel signal curve; based on the first and second parallel signal curves, the parallel position of the laser processing equipment is adjusted to achieve positioning of the laser processing equipment in the first and second directions, respectively. Specifically, the maximum value positions of the first and second parallel signal curves are obtained, and these maximum value positions indicate that the laser beam is perpendicularly incident on the surface to be processed, which is the ideal processing starting point. Based on the maximum value position of the first parallel signal curve, the laser processing equipment is adjusted in a first parallel position; and based on the maximum value position of the second parallel signal curve, the laser processing equipment is adjusted in a second parallel position.
[0047] Wherein, the first direction and the second direction are directions parallel to the plane of the support platform 16, and the first direction and the second direction are perpendicular to each other. For example, as shown... Figure 3 As shown, the first direction is the positive x-axis direction in the figure, and the second direction is the positive y-axis direction. Further, the galvanometer assembly 13 includes multiple galvanometers, and the scanning of the surface to be processed in the first and second directions is achieved by moving each galvanometer. For example, as... Figure 5 As shown, the galvanometer group 13 includes four galvanometers, namely the first galvanometer 131, the second galvanometer 132, the third galvanometer 133, and the fourth galvanometer 134. The left side shows a three-dimensional structural schematic diagram of the galvanometer group 13, the middle shows a planar schematic diagram of the galvanometer group 13 in the first direction, and the right side shows a planar schematic diagram of the galvanometer group 13 in the second direction. When scanning is required in the first direction, the fourth galvanometer 134 and the focusing element 14 are moved synchronously in the first direction. When scanning is required in the second direction, the third galvanometer 133, the fourth galvanometer 134, and the focusing element 14 are moved synchronously in the second direction.
[0048] Furthermore, when the laser processing equipment is positioned, the focusing unit periodically moves the focusing position of the calibration beam in the vertical direction. Specifically, the movable lens 121 is periodically moved within a preset movement range to obtain a focusing signal curve; based on the focusing signal curve, the focusing position of the laser processing equipment is adjusted. It should be noted that the vertical direction refers to the direction perpendicular to the support platform 16.
[0049] Specifically, when the movable lens moves within its movement range for one cycle, the corresponding curve portion on its focusing signal curve is the corresponding single-cycle sub-signal curve. Any maximum point of the single-cycle sub-signal curve is obtained. Based on this maximum point, the movable lens is moved to the corresponding position to adjust the focusing position, thereby enabling the calibration beam to converge on the surface of the surface to be processed. Furthermore, the movement range is updated based on the position of the moved movable lens after movement. Specifically, while keeping the size of the movement range constant, the position of the moved movable lens is used as the center position to update the movement range, thus allowing the adjusted movable lens 121 to have a large adjustment space on both sides, providing greater flexibility during laser processing.
[0050] On the other hand, this embodiment also provides a positioning method for laser processing, used to adjust the laser processing equipment as described above to locate the processing starting point of the laser processing equipment, thereby ensuring that the actual laser scanning path strictly matches the preset ideal scanning path, thus improving the accuracy of laser processing. Specifically, as Figure 6 and Figure 7 As shown, the positioning methods include:
[0051] S100, the workpiece 15 to be processed is fixed on the support platform 16 and initially positioned.
[0052] Preliminary positioning refers to fixing the workpiece 15 to be processed based on a preset processing position. The preset processing position is the position of the workpiece to be processed based on the visual alignment effect and experience of the operator. It should be noted that this preset processing position is within the scanning range of the laser processing equipment to facilitate subsequent fine adjustment of the laser processing equipment.
[0053] Furthermore, the laser 11 is turned on to emit a calibration beam. The calibration beam is incident on the surface of the workpiece 15 to be processed and is reflected as a reflected beam. The reflected beam is received by the signal receiving unit 18.
[0054] S200: The surface to be processed is scanned by a calibration beam in the first direction and the second direction respectively, and the first parallel signal curve and the second parallel signal curve are acquired by the signal receiving unit; the parallel position of the laser processing equipment is adjusted based on the first parallel signal curve and the second parallel signal curve.
[0055] Wherein, the first direction and the second direction are directions parallel to the plane of the support platform 16, and the first direction and the second direction are perpendicular to each other. For example, as shown... Figure 3 and Figure 5As shown, the fourth galvanometer 134 and the focusing element 14 are moved synchronously in the first direction to achieve scanning in the first direction, and the change in the intensity of the reflected beam is received by the signal receiving unit 18 as the first parallel signal curve. The third galvanometer 133, the fourth galvanometer 134 and the focusing element 14 are moved synchronously in the second direction to achieve scanning in the second direction, and the change in the intensity of the reflected beam is received by the signal receiving unit 18 as the second parallel signal curve.
[0056] It should be noted that the light intensity value received by the signal receiving unit 18 may fluctuate due to various factors, and positioning based solely on the light intensity value will result in errors. However, it is worth noting that during the scanning process of the laser beam, the light intensity of the reflected beam exhibits a specific trend, namely, the first parallel signal curve and the second parallel signal curve show specific trends. Specifically, since the galvanometer group 13 does not rotate during scanning but only moves, and the focusing element 14 moves synchronously with each galvanometer, the angle at which the calibration beam is incident on the surface to be processed remains constant. Therefore, when the calibration beam is perpendicularly incident on the surface to be processed, the light intensity of the reflected beam is maximum, and the light intensity gradually decreases on both sides of this perpendicular incident position. For example, as... Figure 8 As shown, if the surface to be processed is a sphere, and the ideal starting point for processing is set as the vertex of the surface, then when the calibration beam is aligned with the central axis of the surface to be processed, i.e. Figure 8 The straight line shown by the dashed line represents the point where the reflected beam has the highest intensity, i.e., the parallel signal curve has its maximum value. The intensity gradually decreases on both sides of the parallel signal curve. Based on this, the ideal starting point of the calibration beam is determined by the trend of the signal curve received by the signal receiving unit 18. This allows for the parallel position adjustment of the laser adjustment device, avoiding inaccurate positioning caused by fluctuations in light intensity and achieving more precise positioning.
[0057] It should be noted that the angle at which the calibration beam is incident on the surface to be processed is set according to the preset ideal processing starting point, and is achieved by adjusting the angle of each galvanometer in the galvanometer group 13 before positioning.
[0058] This embodiment exemplifies that the surface to be processed is a sphere. In actual application scenarios, the surface to be processed can also be other types of surfaces.
[0059] In some alternative implementations, such as Figure 6 and Figure 9 As shown, based on the first parallel signal curve and the second parallel signal curve, the parallel position adjustment of the laser processing equipment includes:
[0060] S210, obtain the maximum value positions of the first parallel signal curve and the second parallel signal curve respectively.
[0061] It should be noted that, since the intensity of the reflected beam is strongest when the calibration beam is incident perpendicularly on the surface to be processed, the maximum positions of the first parallel signal curve and the second parallel signal curve are used to characterize the positions of the surface to be processed perpendicularly in the first direction and the second direction, respectively.
[0062] Specifically, such as Figure 10 As shown, curve a is the first parallel signal curve, and curve b is the ideal signal curve when the current laser processing equipment is in an ideal state in the first direction, that is, the curve where the maximum value position coincides with the position of the current laser processing equipment in the first direction. The difference between the maximum value positions of these two curves, that is, the distance represented by the time interval between the two dashed lines in the figure, is the distance that the laser beam needs to be adjusted in the first direction. The distance represented by the time interval between the two dashed lines is actually the product of the scanning speed when the fourth galvanometer 134 and the focusing element 14 are moved synchronously and the time interval.
[0063] Similarly, for the second parallel signal curve, refer to the first parallel signal curve, and obtain the distance that the laser beam needs to be adjusted in the second direction based on the difference between the second parallel signal curve and its corresponding ideal signal curve.
[0064] S220, based on the maximum position of the first parallel signal curve, the laser processing equipment is adjusted to the first parallel position.
[0065] Specifically, the positions of the galvanometer assembly and the focusing element are adjusted synchronously to perform the first parallel position adjustment of the laser processing equipment.
[0066] For example, please see Figure 10 The position of the galvanometer group 13 corresponding to the maximum value position in curve a is obtained from curve a, and the galvanometer group 13 is adjusted to achieve the first parallel position adjustment of the laser processing equipment. Specifically, if the fourth galvanometer 134 in the galvanometer group 13 moves at a constant speed during the scanning process, the time difference corresponding to the difference between the maximum value positions in curve a and curve b can be obtained. This allows the determination of the distance that the fourth galvanometer 134 needs to move relative to the initial state when the laser beam is perpendicularly incident on the ideal processing starting point, and the corresponding distance is moved in the first direction to achieve the first parallel position adjustment.
[0067] Furthermore, by fitting curves a and b, their corresponding curve equations are obtained, and then the locations of the maxima of curves a and b are calculated. Taking the surface to be processed as a sphere as an example, the fitted curves a and b are circular curve equations. The derivative of this circular curve equation is calculated, and the points where the first derivative is zero and the second derivative is greater than zero are taken as the maxima of the curves.
[0068] S230, based on the maximum position of the second parallel signal curve, adjusts the second parallel position of the laser processing equipment.
[0069] Specifically, the positions of the galvanometer assembly and the focusing element are adjusted synchronously to perform a second parallel position adjustment on the laser processing equipment.
[0070] For example, referring to the steps described above for obtaining the required movement distance in the first direction, the required movement distance in the second direction is obtained based on the time difference between the second parallel signal curve and the maximum position of its corresponding ideal signal curve. This is used to move the third galvanometer 133, the fourth galvanometer 134, and the focusing element 14 in the galvanometer group 13 in the second direction to achieve the second parallel position adjustment. For specific adjustment methods, please refer to the first parallel position adjustment method; this embodiment will not elaborate further.
[0071] Based on this, the galvanometer group 13 is adjusted according to the maximum position of the first parallel signal curve and the second parallel signal curve to avoid errors caused by light intensity fluctuations, thereby achieving more precise positioning adjustment.
[0072] Furthermore, after completing the parallel position adjustment, it is checked whether the difference between the magnitude of the light intensity received by the signal receiving unit 18 and the maximum value of curve ab is less than the difference threshold, in order to determine whether the adjusted laser processing equipment has completed the parallel position adjustment. If so, the next step of focusing position adjustment is performed; otherwise, the first parallel signal curve and the second parallel signal curve are re-scanned and the steps S210 to S230 are repeated. The difference threshold is used to determine the maximum value of normal light intensity fluctuations under the influence of environmental factors. Specifically, those skilled in the art can set the difference threshold according to actual needs; this embodiment does not impose specific limitations.
[0073] S300 periodically moves the focusing position of the calibration beam in the vertical direction and acquires the focusing signal curve through the signal receiving unit 18; based on the focusing signal curve, the focusing position of the laser processing equipment is adjusted.
[0074] Specifically, the movable lens 121 is periodically moved within a preset range of motion so that the signal receiving unit 18 receives and records the light intensity changes of the reflected beam to obtain a focusing signal curve.
[0075] It should be noted that, ideally, the laser beam should be focused on the processing surface during laser processing. Based on this, this embodiment adjusts the position of the movable lens 121 so that the calibration beam can be focused on the surface to be processed, thereby adjusting the focusing position of the laser processing equipment and resulting in better subsequent laser processing effects.
[0076] It should be noted that the intensity of the reflected beam reaches its maximum when the calibration beam is focused on the surface to be processed. Based on this, the focus position can be adjusted by adjusting the laser processing equipment according to the maximum point in the focusing signal curve.
[0077] For example, taking a sphere as the surface to be processed, such as... Figure 11 and Figure 12 As shown, Figure 11 The difference between the focused position of the calibration beam and the ideal processing starting point is shown as follows: , Figure 12 The display shows the focusing signal curve acquired by the periodically moving movable lens 121. The movable lens 121 moves periodically, with the maximum point repeating in each cycle. For ease of operation, this embodiment extracts the curve of a single cycle as a single-cycle sub-signal curve to obtain any maximum point within this single-cycle sub-signal curve. Based on this maximum point, the position of the movable lens corresponding to the ideal processing starting point is obtained, allowing the movable lens 121 to be moved to the corresponding state, thus achieving adjustment of the focusing position of the laser processing equipment. The single-cycle sub-signal curve characterizes the portion of the focusing signal curve corresponding to the vertical movement of the calibration beam's focusing position over one cycle; any maximum point in the single-cycle sub-signal curve represents the point where the derivatives of the two sides of the curve have opposite signs.
[0078] Furthermore, adjusting the laser processing equipment based on the maximum point includes: based on the time corresponding to any maximum point of the single-cycle sub-signal curve, and combined with the periodic variation law of the focusing unit 12, obtaining the position of the focusing unit corresponding to that maximum point, so as to adjust the focus position of the laser processing equipment. Specifically, the periodic variation of the focusing unit 12 is actually the periodic movement of the movable lens 121 within a preset movement range. The movement law of the movable lens 121 is obtained as the periodic variation law of the focusing unit 12. Thus, based on the time corresponding to the maximum point, the position of the movable lens 121 corresponding to that maximum point is obtained, and the movable lens 121 is moved to that position, thereby realizing the adjustment of the focus position of the laser processing equipment.
[0079] To facilitate understanding of the focus position adjustment method described in this embodiment by those skilled in the art, specific examples will be provided below.
[0080] For example, such as Figure 4As shown, the initial position of the movable lens 121 is located at the center of the movement range. The left lens position 122 is shown as the extreme position of the movable lens 121 on the left, and the right lens position 123 is shown as the extreme position of the movable lens 121 on the right. Taking the left side as the positive direction and the initial position of the movable lens 121 as the origin, a coordinate system is constructed. The trajectory of the movable lens 121 within a single cycle is then:
[0081]
[0082] in, Used to characterize the position of the movable lens 121 The moving rate of the movable lens 121 The time required for the movable lens 121 to move a single cycle. This is the time taken for the movable lens 121 to move from its initial position to its current position within the current cycle.
[0083] Based on this, the time corresponding to any maximum point of the single-cycle sub-signal curve is obtained, and the time calculation is converted into the time corresponding to the maximum point in the current cycle. Then, the time corresponding to the current cycle is substituted into the motion trajectory of the movable lens 121 to obtain the position of the movable lens 121 corresponding to the maximum point, thereby realizing the adjustment of the movable lens 121 and thus completing the adjustment of the focusing position of the laser processing equipment.
[0084] Furthermore, after the focus position adjustment is completed, it is checked whether the difference between the light intensity received by the signal receiving unit 18 and the maximum value of the focus signal curve is less than the difference threshold, so as to determine whether the laser processing equipment has completed the focus position adjustment. If so, the positioning adjustment of the laser processing equipment is completed; otherwise, the focus signal curve is re-scanned and the focus position adjustment is repeated based on the maximum value position of the focus signal curve.
[0085] It should be noted that in this embodiment, the position of the movable lens 121 is adjusted by using the maximum value of the focusing signal curve, thereby realizing the focusing position adjustment of the laser processing equipment. This avoids the error caused by adjusting the light intensity value, achieving a better positioning effect, and thus facilitating a better laser processing effect.
[0086] Based on this, the staff used the above positioning method to perform high-precision positioning of the laser processing equipment to ensure that the starting point of the processing is in an ideal state, which is conducive to improving the processing accuracy in the subsequent laser processing process and achieving better processing results.
[0087] It is worth noting that the above embodiments of this application exemplarily use curved surfaces as the surfaces to be processed for illustration. However, those skilled in the art should understand that the positioning method and laser processing equipment of this application can also be used for positioning of planes before laser processing. This application does not impose any specific limitations here.
[0088] Furthermore, to ensure the processing quality of laser processing, it is necessary to ensure that the processing beam remains focused on the processing surface throughout the process. Therefore, when the laser source 11 emits the processing beam, i.e., when the laser processing equipment performs laser processing, the signal receiving unit 18 receives and records the intensity changes of the reflected beam. When the intensity change exceeds a preset threshold, it checks whether the processing beam will focus on the surface to be processed. The threshold value characterizes the maximum normal fluctuation of light intensity under the influence of environmental factors. Specifically, those skilled in the art can set the threshold value according to actual needs; this embodiment does not impose specific limitations.
[0089] In summary, the positioning method provided in this application obtains a first parallel signal curve and a second parallel signal curve by scanning the surface to be processed with a calibration beam, and obtains a focusing signal curve by changing the focusing position of the calibration beam. Based on the first parallel signal curve, the second parallel signal curve, and the focusing signal curve, the laser processing equipment is positioned with high precision. This ensures that when the laser processing equipment starts processing, the processing beam is perpendicularly incident and converges on the ideal processing starting point on the surface to be processed. This ensures that the actual laser scanning path strictly matches the preset ideal scanning path, avoids processing pattern deviation, and helps improve the processing quality of laser scanning processing.
[0090] The descriptions of the processes or structures corresponding to the above figures each have their own emphasis. For parts of a process or structure that are not described in detail, please refer to the relevant descriptions of other processes or structures.
[0091] The above embodiments are merely illustrative of the principles and effects of this application and are not intended to limit this application. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this application. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this application should still be covered by the claims of this application.
Claims
1. A positioning method for laser processing, comprising: The workpiece to be processed is initially positioned; a calibration beam is emitted, which is reflected as a reflected beam after entering the surface to be processed of the workpiece. The surface to be processed is scanned in a first direction by the calibration beam to obtain the intensity change of the reflected beam as a first parallel signal curve; and the surface to be processed is scanned in a second direction by the calibration beam to obtain the intensity change of the reflected beam as a second parallel signal curve; the parallel position of the laser processing equipment is adjusted based on the first parallel signal curve and the second parallel signal curve. The focusing position of the calibration beam is periodically moved in the vertical direction of the support platform, and the focusing signal curve is acquired through the signal receiving unit; based on the focusing signal curve, the focusing position of the laser processing equipment is adjusted.
2. The method according to claim 1, characterized in that, The process of adjusting the parallel position of the laser processing equipment based on the first parallel signal curve and the second parallel signal curve includes: The positions of the maximum values of the first parallel signal curve and the second parallel signal curve are obtained respectively; Based on the location of the maximum value of the first parallel signal curve, the laser processing equipment is adjusted to a first parallel position. The laser processing equipment is adjusted to a second parallel position based on the maximum value of the second parallel signal curve.
3. The method according to claim 2, characterized in that, The laser processing equipment scans using a galvanometer array and focuses using a focusing element; The positions of the galvanometer assembly and the focusing element are adjusted synchronously to perform a first parallel position adjustment and a second parallel position adjustment on the laser processing equipment.
4. The method according to claim 1, characterized in that, The step of adjusting the focus position of the laser processing equipment based on the focus signal curve includes: Based on the focused signal curve, a single-cycle sub-signal curve is extracted, and any maximum point of the single-cycle sub-signal curve is obtained. Based on this maximum point, the focusing position of the laser processing equipment is adjusted. The single-cycle sub-signal curve is the portion of the focusing signal curve corresponding to the position of the calibration beam moving one cycle in the vertical direction of the support platform.
5. The method according to claim 4, characterized in that, The laser processing equipment changes the focusing position through a focusing unit; The position of the focusing unit corresponding to any maximum point of the single-cycle sub-signal curve is obtained in order to adjust the focusing position of the laser processing equipment.
6. A laser processing device, characterized in that, The system includes a laser source and a focusing unit, a galvanometer group, and a focusing element sequentially arranged on the propagation path of the laser beam emitted by the laser source. The focusing unit is used to expand the laser beam and adjust the focusing position of the expanded laser beam. The galvanometer group is used to adjust the position and angle at which the laser beam is incident on the surface to be processed. The focusing element is used to focus the laser beam on the surface to be processed. After the laser beam is incident on the surface to be processed, it is reflected to form a reflected beam. A reflective element is also provided in the optical path between the focusing unit and the laser source, and the reflective element is used to reflect the reflected beam to the signal receiving unit; The signal receiving unit is used to acquire the light intensity changes of the reflected beam.
7. The device according to claim 6, characterized in that, The laser beam emitted by the laser source is a calibration beam or a processing beam; When the laser source emits the calibration beam, the operating power is a preset first power; when the laser source emits the processing beam, the operating power is a preset second power; the first power is lower than the second power.
8. The device according to claim 7, characterized in that, The focusing unit includes at least one movable lens, which moves within a preset range to change the focusing position of the laser beam. When the laser source emits the calibration beam, the movable lens is periodically moved to obtain a focusing signal curve; Based on the focused signal curve, a single-cycle sub-signal curve is extracted, and any maximum point of the single-cycle sub-signal curve is obtained. Based on the maximum point, the movable lens is moved to the corresponding position to adjust the focused position, and the moving range is updated based on the position of the movable lens after the movement.
9. The device according to claim 7, characterized in that, When the laser source emits the calibration beam, the galvanometer group and the focusing element move synchronously in a first direction so that the calibration beam scans the surface to be processed in the first direction; The galvanometer group and the focusing element are moved synchronously in the second direction so that the calibration beam scans the surface to be processed in the second direction; When the laser source emits the processing beam, the galvanometer group is rotated so that the processing beam scans the surface to be processed.
10. The device according to claim 6, characterized in that, The signal receiving unit includes a signal receiving focusing element, an aperture, and a light signal intensity sensor arranged sequentially along the propagation optical path of the reflected beam; the aperture is located at the focal point of the signal receiving focusing element.