Galvanometer-based Laser Engraving Machine Focus Adjustment Method and Laser Engraving Machine

Abstract

The present application discloses a focus adjustment method for a galvanometer-based laser engraving machine and a laser engraving machine. The focus adjustment method for the galvanometer-based laser engraving machine includes the following steps: under a first preset condition, obtaining first length information of a pattern formed by a galvanometer module on a focal plane; under the first preset condition, obtaining second length information of a pattern formed by the galvanometer module on a plane to be engraved; adjusting the distance between the plane to be engraved and the galvanometer module based on the second length information so that the second length information is equal to the first length information; the first preset condition is that the outgoing direction of the galvanometer module rotates from a first starting point to a first ending point. The present application solves the problems that in the related art, the operation of manually adjusting the engraving platform to the laser focal plane is relatively troublesome and the adjustment accuracy is also relatively low.

Description

Technical Field

[0001] The present application relates to the technical field of laser engraving, and in particular, to a focus adjustment method for a galvanometer-based laser engraving machine and a laser engraving machine. Background Art

[0002] The focal length of the optical path used in a laser engraving machine (marking machine) is generally constant. The optical path includes a laser module, a beam expander, a collimation module, and a field lens. Once these components are determined, their focal length is basically determined. The laser beam has the smallest spot, the most concentrated energy, and the highest power per unit area at its focal position. Therefore, the engraving effect is the best at the focal position. At positions far from the focal point (too large or too small), the engraving effect will deteriorate. Therefore, in practical applications, it is necessary to adjust the engraving plane to near the laser focal position to pursue the best effect.

[0003] Common laser engraving machines use the XY architecture. This technology moves the laser head to the specified coordinates through a motor, usually a stepper motor, and controls whether the laser head emits light to complete engraving on the XY plane. This engraving machine can complete large-format engraving, but it has a large volume, poor accuracy, and slow speed. Industrial marking machines are mostly small in area and use galvanometer technology, which has a fast printing speed, high accuracy, and low noise.

[0004] With the development of component technology, there are more and more private customization scenarios, and desktop engraving machines have gradually appeared on the market. However, in actual use, due to the different shapes and heights of the engraved objects, the engraving plane is not necessarily near the laser focal point, so a focusing operation is required. Currently, manual focusing is used, usually by manually measuring with a ruler and adjusting the height of the engraving plane. However, this adjustment method is relatively troublesome and the adjustment accuracy is also low. Summary of the Invention

[0005] The main purpose of the present application is to provide a focus adjustment method for a galvanometer-based laser engraving machine and a laser engraving machine, so as to solve the problems in the related art that the operation of manually adjusting the engraving platform to the laser focal plane is relatively troublesome and the adjustment accuracy is also low.

[0006] To achieve the above object, the present application provides a focus adjustment method for a galvanometer-based laser engraving machine, and the focus adjustment method for the galvanometer-based laser engraving machine includes the following steps:

[0007] Under a first preset condition, obtain the first length information of the pattern formed by the galvanometer module on the focal plane;

[0008] Under a first preset condition, obtain the second length information of the pattern formed by the galvanometer module on the plane to be engraved;

[0009] Adjust the distance between the plane to be engraved and the galvanometer module based on the second length information, so that the second length information is equal to the first length information;

[0010] The first preset condition is that the emission direction of the galvanometer module rotates from the first starting direction to the first ending direction.

[0011] Further, adjusting the distance between the plane to be engraved and the galvanometer module based on the second length information so that the second length information is equal to the first length information is specifically:

[0012] Obtain the length difference between the first length information and the second length information. When the length difference is positive, control the plane to be engraved to move away from the galvanometer module;

[0013] When the length difference is negative, control the plane to be engraved to move towards the galvanometer module.

[0014] Further, under the first preset condition, obtain the first length information of the pattern formed by the galvanometer module on the focal plane, specifically:

[0015] The camera unit obtains all the spot images formed on the focal plane when the galvanometer module moves under the first preset condition;

[0016] Form a spot pattern based on all the spot images, and determine the first length information according to the number of pixels in the spot pattern; or,

[0017] Determine the position of the focal plane based on the design structure of the galvanometer module;

[0018] According to the distance between the focal plane and the galvanometer module, the angle between the first starting direction and the normal line of the galvanometer module, and the angle between the first ending direction and the normal line of the galvanometer module, use trigonometric functions to determine the first length information.

[0019] Further, under the first preset condition, obtain the second length information of the pattern formed by the galvanometer module on the plane to be engraved, specifically:

[0020] The camera unit obtains all the spot images formed on the plane to be engraved when the galvanometer module moves under the first preset condition;

[0021] Form a spot pattern based on all the spot images, and determine the second length information according to the number of pixels in the spot pattern.

[0022] Further, the moving time of the galvanometer module under the first preset condition is T, and the exposure time of the camera unit is greater than T.

[0023] Further, the laser power emitted by the galvanometer module is the lowest power that the camera unit can recognize.

[0024] Further, the rotation angle of the galvanometer module from the first starting direction to the first ending direction is the maximum rotation angle of the galvanometer module;

[0025] The first starting direction and the first ending direction are symmetric along the normal line of the galvanometer module.

[0026] Further, the calculation method of the moving distance of the plane to be engraved is as follows:

[0027] Δh = (| L E0F0 -L EF |) / (2 * tanβ);

[0028] Δh is the moving distance of the plane to be engraved;

[0029] L E0F0 is the first length information;

[0030] L EF is the second length information;

[0031] β is the angle between the first starting direction and the normal line of the galvanometer module, or the angle between the first ending direction and the normal line of the galvanometer module;

[0032] When L E0F0 -L EF is a positive value, control the plane to be engraved to move away from the galvanometer module;

[0033] When L E0F0 -L EF is a negative value, control the plane to be engraved to move towards the galvanometer module.

[0034] Further, control the plane to be engraved to move to the specified position with the moving distance Δh and the moving direction;

[0035] Under the first preset condition, obtain the third length information of the pattern formed by the galvanometer module on the plane to be engraved;

[0036] Based on the third length information, adjust the distance between the plane to be engraved and the galvanometer module so that the third length information is equal to the first length information.

[0037] According to another aspect of the present application, a galvanometer-based laser engraving machine is provided, including a laser generator, a galvanometer module, a galvanometer module rotation mechanism, and further including: a camera unit, a carving tray linear drive mechanism, a controller; wherein,

[0038] The camera unit is arranged close to the output end of the galvanometer module;

[0039] The plane to be engraved is arranged on the carving tray, and the carving tray linear drive mechanism is used to drive the carving tray to move linearly towards or away from the galvanometer module;

[0040] The controller is configured to control the action of the galvanometer module rotation mechanism to drive the galvanometer module to act under a first preset condition, where the first preset condition is that the emission direction of the galvanometer module rotates from a first starting direction to a first ending direction;

[0041] The camera unit is configured to obtain the pattern formed by the galvanometer module on the focal plane under the first preset condition, and to obtain the pattern formed by the galvanometer module on the plane to be engraved under the first preset condition;

[0042] The controller is configured to determine first length information based on the pattern formed by the galvanometer module on the focal plane, and to determine second length information based on the pattern formed by the galvanometer module on the plane to be engraved, and to control the linear drive mechanism of the engraving tray based on the second length information to adjust the distance between the plane to be engraved and the galvanometer module so that the second length information is equal to the first length information.

[0043] In the embodiment of the present application, by obtaining the first length information of the pattern formed by the galvanometer module on the focal plane under the first preset condition; obtaining the second length information of the pattern formed by the galvanometer module on the plane to be engraved under the first preset condition; adjusting the distance between the plane to be engraved and the galvanometer module based on the second length information so that the second length information is equal to the first length information; the first preset condition is that the emission direction of the galvanometer module rotates from a first starting direction to a first ending direction, the purpose of comparing the second length information formed by the galvanometer module on the plane to be engraved with the first length information formed on the calibrated focal plane, judging the relative position between the plane to be engraved and the focal plane according to the comparison result, and adjusting the position of the plane to be engraved to coincide with the focal plane is achieved, thereby realizing the technical effect of reducing the operation difficulty of adjusting the position of the plane to be engraved and improving the adjustment accuracy, and further solving the problem that the operation of manually adjusting the engraving platform to the laser focal plane in the related art is more troublesome and the adjustment accuracy is also lower. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The drawings forming a part of this application are used to provide a further understanding of this application, making other features, objects, and advantages of this application more obvious. The schematic embodiments and descriptions of the drawings of this application are used to explain this application and do not constitute an improper limitation of this application. In the drawings:

[0045] Figure 1 is a schematic diagram according to an embodiment of the present application;

[0046] Wherein, 1 is a galvanometer module, 2 is a controller, 3 is a camera unit, 4 is a linear drive mechanism of the engraving tray, 5 is a plane to be engraved, and 6 is a focal plane. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0047] To enable those skilled in the art to better understand the solution of this application, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are only a part of the embodiments of this application, rather than all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of this application.

[0048] It should be noted that the terms "first", "second", etc. in the specification and claims of this application and the above-mentioned accompanying drawings are used to distinguish similar objects, and do not necessarily need to be used to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so as to describe the embodiments of this application here.

[0049] In this application, the orientation or positional relationship indicated by terms such as "upper", "lower", "inner", etc. is based on the orientation or positional relationship shown in the accompanying drawings. These terms are mainly used to better describe this application and its embodiments, and are not used to limit that the indicated device, element or component must have a specific orientation, or be constructed and operated in a specific orientation.

[0050] Moreover, in addition to being able to represent an orientation or positional relationship, some of the above-mentioned terms may also be used to represent other meanings. For example, the term "upper" may also be used to represent a certain attachment relationship or connection relationship in some cases. For those of ordinary skill in the art, the specific meanings of these terms in this application can be understood according to specific circumstances.

[0051] In addition, terms such as "arranged", "provided with", "connected", "fixed", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or there can also be internal communication between two devices, elements or components. For those of ordinary skill in the art, the specific meanings of the above-mentioned terms in this application can be understood according to specific circumstances.

[0052] In addition, the meaning of the term "plurality" should be two or more.

[0053] It should be noted that, without conflict, the embodiments in this application and the features in the embodiments can be combined with each other. The following will refer to the accompanying drawings and combine the embodiments to detail this application.

[0054] As Figure 1 shown, the embodiment of this application provides a focus adjustment method for a galvanometer-based laser engraving machine. The focus adjustment method for the galvanometer-based laser engraving machine includes the following steps:

[0055] Under the first preset condition, obtain the first length information of the pattern formed by the galvanometer module 1 on the focal plane 6;

[0056] Under the first preset condition, obtain the second length information of the pattern formed by the galvanometer module 1 on the plane to be engraved 5;

[0057] Based on the second length information, adjust the distance between the plane to be engraved 5 and the galvanometer module 1 so that the second length information is equal to the first length information;

[0058] The first preset condition is that the outgoing direction of the galvanometer module 1 rotates from the first starting direction to the first ending direction.

[0059] In this embodiment, the adjustment method is applied to a laser engraving machine with a galvanometer module 1. The optical path of the laser engraving machine includes a laser generator, a beam expander unit, a collimation unit, a field lens unit, and a galvanometer module 1. The galvanometer module 1 can be driven to rotate within a certain angle range. For example, as Figure 1 shown, the galvanometer module 1 can rotate a certain angle to the left and right sides respectively with the normal line as the reference, or can rotate a certain angle to the front and back sides respectively with the normal line as the reference. The maximum angle that the galvanometer module 1 can rotate is limited by the structure of the galvanometer module 1. Generally, it can rotate 30° or 45°, etc. The rotation of the galvanometer module 1 and the opening and closing of the laser generator can be uniformly controlled by the controller 2.

[0060] Since the focal length of the galvanometer module 1 is also basically determined after the structure of the optical path is determined, that is, the distance between the focal plane 6 and the outgoing end of the galvanometer module 1 is a fixed value, such as Figure 1 the h0 shown, the position of the focal plane 6 can be determined according to this fixed value. The determination method of the first length information can be as follows:

[0061] Place the calibration plate according to the position of the focal plane 6 so that the upper surface of the calibration plate coincides with the position of the focal plane 6; control the laser generator to turn on and operate at a low power by the controller 2, and then control the galvanometer module 1 to perform a rotation action according to the first preset condition (that is, control the outgoing direction of the galvanometer module 1 to rotate from the first starting direction to the first ending direction, as Figure 1 shown, move from the A direction to the B direction). During the rotation of the galvanometer module 1 according to the first preset condition, at each time point, a spot image will be formed on the calibration plate. After combining the spot images at each time point, a pattern composed of continuous spots on the calibration plate can be obtained. The pattern can be linear, frame-shaped, circular, etc. The finally formed pattern is determined by the rotation mode of the galvanometer module 1. For example, when the outgoing direction of the galvanometer module 1 moves in a direction forming a straight line, the pattern formed by combining all the spots is a straight line; when the outgoing direction of the galvanometer module 1 moves in a direction forming a rectangle, the pattern formed by combining all the spots is a rectangle.

[0062] After obtaining the pattern formed by the galvanometer module 1 on the calibration plate, the length of the pattern (when the pattern is rectangular, this length is the perimeter) can be obtained by analyzing the number of pixels of the pattern, that is, the first length information. The first length information represents the length of the pattern that will be formed on the focal plane 6 after the galvanometer module 1 moves according to the first preset condition. The first length information is a fixed value, which can be calibrated in the above manner when the laser engraving machine product is completed and the result is written into the program or directly displayed.

[0063] During the actual engraving process, due to the different thicknesses of the objects to be engraved, the engraving plane 5 may be higher than or lower than the focal plane 6 (as Figure 1 shown), so it is necessary to adjust the position of the engraving plane 5 to make it coincide with the focal plane 6. Specifically, in this embodiment, the galvanometer module 1 still rotates according to the first preset condition, so that at each time point, a spot image is formed on the engraving plane 5. After combining the spot images at each time point, a pattern composed of continuous spots on the engraving plane 5 can be obtained. This pattern and the pattern formed on the focal plane 6 are similar patterns.

[0064] The length of the pattern (when the pattern is rectangular, this length is the perimeter) can be obtained by analyzing the number of pixels of the pattern, that is, the second length information. The second length information represents the length of the pattern that will be formed on the engraving plane 5 after the galvanometer module 1 moves according to the first preset condition. Since the image range captured by the camera is fixed, it can be understood that in addition to obtaining the length information by pixel analysis of the pattern, the length information can also be obtained according to the position of the pattern formed by the spots on the image captured by the camera. When the engraving plane 5 is lower than the focal plane 6, in the captured image, the area occupied by the pattern in the entire image will be larger. Similarly, when the engraving plane 5 is higher than the focal plane 6, in the captured image, the area occupied by the pattern in the entire image will be smaller.

[0065] As Figure 1 shown, taking the pattern as a straight line as an example, when the engraving plane 5 is lower than the focal plane 6, the length of the straight line formed on the engraving plane 5 is greater than the length of the straight line formed on the focal plane 6. Therefore, it is necessary to control the engraving plane 5 to rise so that the length of the straight line (the second length information) formed by the galvanometer module 1 according to the first preset condition is the same as the length of the straight line on the focal plane 6 (the first length information). When the engraving plane is higher than the focal plane 6, the length of the straight line formed on the engraving plane 5 is less than the length of the straight line formed on the focal plane 6. Similarly, it is necessary to control the engraving plane 5 to descend so that the second length information is the same as the first length information.

[0066] The lifting of the plane 5 to be engraved can be achieved through a dedicated lifting device. For example, place the object to be engraved at the output end of the lifting device. The lifting device is connected to the controller 2, and the controller 2 controls the lifting movement of the plane 5 to be engraved according to the second length information, so that the second length information of the pattern formed on the plane 5 to be engraved is the same as the first length information on the calibrated focal plane 6, which means that the plane 5 to be engraved coincides with the focal plane 6.

[0067] In the method for adjusting the position of the plane 5 to be engraved in this embodiment, the camera unit 3 can be used to obtain the spot image formed on the plane 5 to be engraved. The camera unit 3 obtains the pattern composed of the spot images through long-time exposure, or the controller 2 generates the pattern based on the spot images at multiple different time points. Then the controller 2 analyzes the number of pixels of the pattern and calculates the adjustment direction and distance of the plane 5 to be engraved. After the calculation, the lifting device is controlled to adjust the distance between the plane 5 to be engraved and the galvanometer module 1. Compared with the traditional method of manually measuring the height, the entire adjustment process does not require manual intervention, reducing the operation difficulty and improving the adjustment accuracy.

[0068] To further improve the adjustment accuracy, the pattern formed by the galvanometer module 1 on the focal plane 6 during calibration is preferably a rectangle, and the pattern formed by the galvanometer module 1 on the plane 5 to be engraved during adjustment is also a rectangle. Since the rectangular pattern is formed by the rotation of the galvanometer module 1 in four directions, judging the position of the plane 5 to be engraved according to the perimeter comparison of the rectangle will be more accurate than judging according to the length comparison of the straight line.

[0069] Furthermore, based on the second length information, the distance between the plane 5 to be engraved and the galvanometer module 1 is adjusted so that the second length information is equal to the first length information. Specifically:

[0070] Obtain the length difference between the first length information and the second length information. The first length information is a calibrated value, and the second length information is converted from the pixels of the pattern formed on the plane 5 to be engraved. When judging the adjustment direction of the plane 5 to be engraved, the length difference can be obtained by subtracting the second length information from the first length information. When the length difference is positive, it indicates that the plane 5 to be engraved is closer to the galvanometer module 1 relative to the focal plane 6, so it is necessary to control the plane 5 to be engraved to move away from the galvanometer module 1; when the length difference is negative, it indicates that the plane 5 to be engraved is farther from the galvanometer module 1 relative to the focal plane 6, so it is necessary to control the plane 5 to be engraved to move towards the galvanometer module 1.

[0071] Furthermore, under the first preset condition, obtain the first length information of the pattern formed by the galvanometer module 1 on the focal plane 6. Specifically:

[0072] The camera unit 3 acquires all the spot images formed on the focal plane 6 when the galvanometer module 1 moves under the first preset condition;

[0073] Based on all the spot images, a spot pattern is formed, and the first length information is determined according to the number of pixels in the spot pattern; or,

[0074] Based on the design structure of the galvanometer module 1, the position of the focal plane 6 is determined;

[0075] According to the distance between the focal plane 6 and the galvanometer module 1, the angle between the first starting direction and the normal line of the galvanometer module 1, and the angle between the first ending direction and the normal line of the galvanometer module 1, the first length information is determined using trigonometric functions.

[0076] Specifically, the specific method for determining the first length information by the camera unit 3 has been specifically described in the above embodiments. Therefore, in this embodiment, the method for determining the first length information using trigonometric functions is described:

[0077] As Figure 1 shown, it is set that the first preset condition is that the outgoing direction of the galvanometer module 1 can rotate β° to the left and right respectively based on the normal line, that is, the angle between the first starting direction and the normal line of the galvanometer module 1 is β°, and the angle between the first ending direction and the normal line of the galvanometer module 1 is β°. According to the structure of the optical path, the focal length of the galvanometer module 1 is determined to be h0, that is, the distance between the focal plane 6 and the galvanometer module 1 is h0. Therefore, when the galvanometer module 1 moves according to the first preset condition, the length of the pattern formed on the focal plane 6 is equal to 2 * h0 * tan(β°).

[0078] Furthermore, under the first preset condition, the second length information of the pattern formed by the galvanometer module 1 on the plane to be engraved 5 is acquired, specifically:

[0079] The camera unit 3 acquires all the spot images formed on the plane to be engraved 5 when the galvanometer module 1 moves under the first preset condition;

[0080] Based on all the spot images, a spot pattern is formed, and the second length information is determined according to the number of pixels in the spot pattern.

[0081] The camera unit 3 used in this embodiment can be a conventional camera, or an industrial camera or an infrared lens suitable for use in low light conditions, depending on the product usage scenario or cost constraints. The camera unit 3 can continuously take pictures during the movement time of the galvanometer module 1, and send all the captured spot images to the controller 2 in chronological order. The graphic collector in the controller 2 receives them, and the central processor performs stitching processing and analysis to obtain the second length information. It is also possible to directly obtain an image with a complete line segment by controlling the exposure time of the camera unit 3, and the controller 2 directly calculates and processes the complete image to obtain the second length information. Specifically, the movement time of the galvanometer module 1 under the first preset condition is T, and the exposure time of the camera unit 3 is greater than T.

[0082] To protect the plane to be engraved 5 from being burned by high-power laser and also protect the photosensitive unit inside the camera, the laser power emitted by the galvanometer module 1 is the lowest power that can be recognized by the camera unit 3.

[0083] As Figure 1 shown, the rotation angle of the emission direction of the galvanometer module 1 from the first starting direction to the first ending direction is the maximum rotation angle of the galvanometer module 1 (such as Figure 1 2β shown in

[0084] Further, the calculation method of the moving distance of the plane to be engraved 5 is:

[0085] Δh = (| L E0F0 - L EF |) / (2 * tanβ);

[0086] Δh is the moving distance of the plane to be engraved 5;

[0087] L E0F0 is the first length information;

[0088] L EF is the second length information;

[0089] β is the angle between the first starting direction and the normal of the galvanometer module 1, or the angle between the first ending direction and the normal of the galvanometer module 1;

[0090] When L E0F0 - L EF is positive, control the plane to be engraved 5 to move away from the galvanometer module 1;

[0091] When L E0F0 - L EF is negative, control the plane to be engraved 5 to move towards the galvanometer module 1.

[0092] In this embodiment, the moving distance and moving direction of the plane to be engraved 5 calculated can be directly used to control the plane to be engraved 5 to move to the focal plane 6 or a position close to the focal plane 6. Since there will be a certain moving error in the lifting device that controls the movement of the plane to be engraved, in order to improve the moving accuracy of the plane to be engraved 5, the plane to be engraved 5 is controlled to move with a moving distance Δh and a moving direction for rough adjustment of the position of the plane to be engraved 5.

[0093] Under the first preset condition, the third length information of the pattern formed by the galvanometer module 1 on the plane to be engraved 5 is obtained; based on the third length information, the distance between the plane to be engraved 5 and the galvanometer module 1 is adjusted so that the third length information is equal to the first length information, thereby performing fine adjustment of the position of the plane to be engraved 5. Since the position adjustment of the plane to be engraved 5 in this embodiment is divided into two steps, the moving error of the plane to be engraved 5 can be reduced and the moving accuracy can be improved.

[0094] As Figure 1 shown, under the first preset condition, the straight line formed by the galvanometer module on the focal plane is E0F0. When the position of the plane to be engraved 5 is higher than the focal plane 6, the straight line formed by the galvanometer module 1 on the plane to be engraved 5 is E1F1, and the distance between the plane to be engraved 5 and the galvanometer module 1 is h1; when the position of the plane to be engraved 5 is lower than the focal plane 6, the straight line formed by the galvanometer module 1 on the plane to be engraved 5 is E2F2, and the distance between the plane to be engraved 5 and the galvanometer module 1 is h2. Δh = h2 - h0, or Δh = h0 - h1.

[0095] As Figure 1 shown, according to another aspect of the present application, a galvanometer-based laser engraving machine is provided, including a laser generator, a galvanometer module 1, and a galvanometer module rotation mechanism. The laser generator, the galvanometer module 1, and the galvanometer module rotation mechanism are the structures of an existing laser engraving machine.

[0096] The laser engraving machine in this embodiment improves the camera unit 3, the engraving tray linear drive mechanism 4, and the controller 2 on the basis of the existing ones; among them,

[0097] The camera unit 3 is arranged close to the output end of the galvanometer module 1;

[0098] The plane to be engraved 5 is arranged on the engraving tray. When in use, the object to be engraved is placed on the engraving tray. The engraving tray linear drive mechanism 4 is used to drive the engraving tray to move linearly towards or away from the galvanometer module 1. When the galvanometer module 1 is located above the plane to be engraved 5, the engraving tray linear drive mechanism 4 is used to control the lifting of the plane to be engraved 5. When the galvanometer module 1 is located on the side of the plane to be engraved 5, the engraving tray linear drive mechanism 4 is used to control the horizontal linear movement of the plane to be engraved 5;

[0099] The controller 2 is configured to determine the first length information based on the pattern formed by the galvanometer module 1 on the focal plane 6, and determine the second length information based on the pattern formed by the galvanometer module 1 on the plane to be engraved 5, and control the linear drive mechanism 4 of the engraving tray based on the second length information to adjust the distance between the plane to be engraved 5 and the galvanometer module 1 so that the second length information is equal to the first length information.

[0100] The controller 2 is composed of a central processing unit and an image collector. The image collector is connected to the camera unit 3 wirelessly or wiredly and can receive the images captured by the camera unit 3. The central processing unit is connected to the image collector to process the received images and calculate the adjustment direction and adjustment distance of the plane to be engraved 5, and then control the linear drive mechanism 4 of the engraving tray to make the plane to be engraved 5 coincide with the focal plane 6.

[0101] At the same time, the central processing unit can also control the movement of the galvanometer module rotation mechanism to drive the galvanometer module 1 to act under the first preset condition. The first preset condition is that the emission direction of the galvanometer module 1 rotates from the first starting direction to the first ending direction. For example, after the central processing unit receives the focus adjustment instruction, it controls the laser emitter and the camera unit 3 to start, and then controls the movement of the galvanometer module rotation mechanism to obtain the second length information.

[0102] The camera unit 3 is configured to obtain the pattern formed by the galvanometer module 1 on the focal plane 6 under the first preset condition, and obtain the pattern formed by the galvanometer module 1 on the plane to be engraved 5 under the first preset condition; the camera unit 3 can be directly controlled by the central processing unit in the controller 2.

[0103] The above are only the preferred embodiments of the present application and are not used to limit the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A focus adjustment method for a galvanometer-based laser engraving machine, characterized in that, It includes the following steps: Under the first preset condition, obtain the first length information of the pattern formed by the galvanometer module on the focal plane; Under the first preset condition, obtain the second length information of the pattern formed by the galvanometer module on the plane to be engraved; Based on the second length information, adjust the distance between the plane to be engraved and the galvanometer module so that the second length information is equal to the first length information; The first preset condition is that the outgoing direction of the galvanometer module rotates from the first starting direction to the first ending direction.

2. The method for adjusting the focus of a galvanometer-based laser engraving machine according to claim 1, wherein The adjusting the distance between the plane to be engraved and the galvanometer module based on the second length information so that the second length information is equal to the first length information is specifically: Obtain the length difference between the first length information and the second length information. When the length difference is positive, control the plane to be engraved to move away from the galvanometer module; When the length difference is negative, control the plane to be engraved to move towards the galvanometer module.

3. The focus adjustment method of the galvanometer-based laser engraving machine according to claim 2, wherein Under the first preset condition, obtaining the first length information of the pattern formed by the galvanometer module on the focal plane is specifically: The camera unit obtains all the spot images formed on the focal plane when the galvanometer module moves under the first preset condition; Form a spot pattern based on all the spot images, and determine the first length information according to the number of pixels in the spot pattern; Or, Determine the position of the focal plane based on the design structure of the galvanometer module; According to the distance between the focal plane and the galvanometer module, the angle between the first starting direction and the normal line of the galvanometer module, and the angle between the first ending direction and the normal line of the galvanometer module, use trigonometric functions to determine the first length information.

4. The focus adjustment method of the galvanometer-based laser engraving machine according to claim 3, wherein Under the first preset condition, obtaining the second length information of the pattern formed by the galvanometer module on the plane to be engraved is specifically: The camera unit obtains all the spot images formed on the plane to be engraved when the galvanometer module moves under the first preset condition; Form a spot pattern based on all the spot images, and determine the second length information according to the number of pixels in the spot pattern.

5. The focus adjustment method of the galvanometer-based laser engraving machine according to claim 4, wherein The moving time of the galvanometer module under the first preset condition is T, and the exposure time of the camera unit is greater than T.

6. The focus adjustment method of the galvanometer-based laser engraving machine according to claim 5, characterized in that, The laser power emitted by the galvanometer module is the lowest power that can be recognized by the camera unit.

7. The focus adjustment method of the galvanometer-based laser engraving machine according to any one of claims 1 to 6, characterized in that, The rotation angle of the outgoing direction of the galvanometer module rotating from the first starting direction to the first ending direction is the maximum rotation angle of the galvanometer module; The first starting direction and the first ending direction are symmetric about the normal line of the galvanometer module.

8. The focus adjustment method of the galvanometer-based laser engraving machine according to claim 7, characterized in that The calculation method of the moving distance of the plane to be engraved is: Δh = (| L E0F0 -L EF |) / (2 * tanβ); Δh is the moving distance of the plane to be engraved; L E0F0 is the first length information; L EF is the second length information; β is the angle between the first starting direction and the normal line of the galvanometer module, or the angle between the first ending direction and the normal line of the galvanometer module; When L E0F0 -L EF is positive, control the plane to be engraved to move away from the galvanometer module; When L E0F0 -L EF is negative, control the plane to be engraved to move towards the galvanometer module.

9. The focus adjustment method of the galvanometer-based laser engraving machine according to claim 8, wherein Control the plane to be engraved to move with the moving distance Δh and the moving direction; Under the first preset condition, obtain the third length information of the pattern formed by the galvanometer module on the plane to be engraved; Based on the third length information, adjust the distance between the plane to be engraved and the galvanometer module so that the third length information is equal to the first length information.

10. A galvanometer-based laser engraving machine, comprising a laser generator, a galvanometer module, and a galvanometer module rotation mechanism, characterized in that, It further includes: A camera unit, a linear drive mechanism for the engraving tray, and a controller; wherein, The camera unit is arranged close to the outgoing end of the galvanometer module; The plane to be engraved is provided on the engraving tray, and the linear driving mechanism of the engraving tray is used to drive the engraving tray to move linearly towards or away from the galvanometer module; The controller is configured to control the action of the galvanometer module rotation mechanism to drive the galvanometer module to act under a first preset condition, and the first preset condition is that the emission direction of the galvanometer module rotates from a first starting direction to a first ending direction; The camera unit is configured to obtain the pattern formed by the galvanometer module on the focal plane under the first preset condition, and to obtain the pattern formed by the galvanometer module on the plane to be engraved under the first preset condition; The controller is configured to determine the first length information based on the pattern formed by the galvanometer module on the focal plane, and to determine the second length information based on the pattern formed by the galvanometer module on the plane to be engraved, and to control the linear driving mechanism of the engraving tray based on the second length information to adjust the distance between the plane to be engraved and the galvanometer module so that the second length information is equal to the first length information.

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