Filament-forming cutting head, laser cutting system, and filament-forming cutting head design method

Abstract

A filament-forming cutting head, a laser cutting system, and a filament-forming cutting head design method, relating to the technical field of laser control. The filament-forming cutting head comprises a shaping element (101), a collimating element (102), and a focusing element (103) that are sequentially arranged in the propagation direction of light. A laser beam emitted by a laser (201) is converted into a flat-top beam by means of the shaping element (101) having a first surface profile, a divergence angle of the flat-top beam is controlled by means of collimation of the collimating element (102), and by the focusing element (103) having a second surface profile, the flat-top beam is finally converged into a target filament-forming beam having high energy utilization rate and high uniformity. The filament-forming beam enables laser cutting of hard and brittle materials, improving the processing effect. In addition, the filament-forming cutting head uses all-refractive elements, which not only offers the advantages such as a simple design method, low difficulty in lens processing, and applicability to a variety of materials, but also can convert an entire Gaussian beam into a flat-top beam, thereby fully using input energy for the filament-forming beam.

Description

Wire cutting head, laser cutting system and design method of wire cutting head

[0001] Cross-reference to related applications

[0002] This disclosure claims priority to Chinese Patent Application No. 202411587593.6, filed on November 7, 2024, entitled “Wire-cutting head, laser cutting system and design method of wire-cutting head”, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to the field of laser control technology, and in particular to a filament cutting head, a laser cutting system, and a design method for the filament cutting head. Background Technology

[0004] With the continuous development of the electronics industry, most of the materials used in electronic products, such as panels, are hard and brittle materials, including sapphire, glass, and ceramics. The thickness of these hard and brittle material components varies across different electronic products, requiring suitable and controllable processing methods, which presents a challenge to the hard and brittle material processing industry.

[0005] In existing technologies, when lasers are used to cut or process hard and brittle materials, the size of the laser spot and the depth of focus are limited by the diffraction limit and optical aberrations, resulting in the phenomenon that the laser beam cannot penetrate the hard and brittle material, making it difficult to achieve the desired processing effect.

[0006] Public content

[0007] The purpose of this disclosure is to provide a filament cutting head, a laser cutting system, and a filament cutting head design method to achieve a filament beam with high energy utilization and high uniformity, thereby improving processing results.

[0008] In a first aspect, embodiments of this disclosure provide a filament cutting head, including a shaping element, a collimating element, and a focusing element arranged sequentially along the direction of light propagation;

[0009] The shaping element is an aspherical lens; the shaping element has a first surface profile and is configured to convert the input non-flat-top beam into a flat-top beam output; the first surface profile is determined based on the first beam energy distribution information on the input surface of the shaping element, as well as the desired beam propagation distance and the desired flat-top beam energy distribution information;

[0010] The collimating element is configured to collimate the input flat-top beam; the distance between the collimating element and the shaping element is consistent with the desired beam propagation distance;

[0011] The focusing element is an aspherical lens; the focusing element has a second surface profile, configured to converge the collimated flat-top beam into a target filamentary beam; the second surface profile is determined based on the flat-top beam diameter information and the second beam energy distribution information on the input surface of the focusing element, as well as the desired depth of focus and the peak energy distribution information along the optical axis within the depth of focus.

[0012] In an optional embodiment, the filament cutting head further includes a controller, a beam analyzer, and a transmission device; the beam analyzer and the transmission device are respectively connected to the controller;

[0013] The beam analyzer is configured to detect beam quality information within the focal depth range of the focusing element and send it to the controller; wherein, the beam quality information includes beam energy distribution information;

[0014] The controller is configured to adjust the distance between the shaping element and the collimating element based on the received light spot energy distribution information.

[0015] In an optional embodiment, the controller is further configured to compare the received spot energy distribution information with preset standard energy distribution information, and when the comparison result is inconsistent, send an adjustment command to the transmission device.

[0016] The transmission device is configured to move the shaping element when it receives an adjustment command, so as to adjust the distance between the shaping element and the collimating element.

[0017] In an optional embodiment, the transmission device includes a fixed base, a motor, a crank-connecting rod mechanism, a mirror mount, and a guide rail;

[0018] The motor and guide rail are fixed on the fixed base, and the lens mount is slidably connected to the guide rail. The lens mount is configured to install shaping elements and / or collimating elements. The motor is connected to the lens mount through a crank-connecting rod mechanism, which drives the lens mount to slide on the guide rail.

[0019] In an optional embodiment, the beam quality information also includes spot size information and depth of focus information; the controller is also configured to detect the quality of the filament cutting head based on the received spot size information and depth of focus information.

[0020] Secondly, embodiments of this disclosure also provide a laser cutting system, including a laser and a filament cutting head as described in the first aspect; the laser emits a laser beam toward the filament cutting head.

[0021] Thirdly, this disclosure also provides a method for designing a filament cutting head, applied to a filament cutting head configured as in the first aspect; the method includes:

[0022] Obtain the design data of the shaping element and the focusing element corresponding to the filament cutting head; wherein, the design data of the shaping element includes the first beam energy distribution information on the input surface of the shaping element, as well as the desired beam propagation distance and the desired flat-top beam energy distribution information, and the design data of the focusing element includes the flat-top beam diameter information and the second beam energy distribution information on the input surface of the focusing element, as well as the desired depth of focus and the peak energy distribution information along the optical axis within the depth of focus.

[0023] Based on the design data of the shaping element, determine the first surface shape of the shaping element;

[0024] Based on the design data of the focusing element, determine the second surface shape of the focusing element.

[0025] In an optional embodiment, determining the first surface profile of the shaping element based on the shaping element design data includes:

[0026] Based on the desired beam propagation distance and the desired flat-top beam energy distribution information, determine the energy distribution information of the third beam on the output surface of the shaping element;

[0027] The first surface shape of the shaping element is determined based on the energy distribution information of the third beam, the energy distribution information of the first beam, and multiple preset first surface shape parameters.

[0028] In an optional embodiment, determining the second surface profile of the focusing element based on the focusing element design data includes:

[0029] Based on the desired depth of focus and peak energy distribution information, determine the angle information between multiple outgoing rays in the output beam of the focusing element and the optical axis;

[0030] The second surface shape of the focusing element is determined based on the included angle information, the diameter information of the flat-top beam, the energy distribution information of the second beam, and multiple preset second surface shape parameters.

[0031] In an optional embodiment, the first beam energy distribution information includes the energy intensity of the Gaussian beam at each location, represented in matrix form; the surface shape formulas corresponding to the first and second surface shapes are:

[0032] Where z is the aspherical elevation at a fixed Y, and Y is the elevation of the aspherical surface at any horizontal distance from the center of the lens plane.

[0033] The distance extending in the direction, R, k, A4, A6, A8, A 10 A 12 A 14 A 16 These are the surface parameters.

[0034] The filamentary cutting head, laser cutting system, and filamentary cutting head design method provided in this disclosure include a shaping element, a collimating element, and a focusing element arranged sequentially along the light propagation direction. The shaping element is an aspherical lens. The shaping element has a first surface shape and is configured to convert an input non-flat-top beam into a flat-top beam output. The first surface shape is determined based on the first beam energy distribution information on the input surface of the shaping element, as well as the desired beam propagation distance and the desired flat-top beam energy distribution information. The collimating element is configured to collimate the input flat-top beam. The distance between the collimating element and the shaping element is consistent with the desired beam propagation distance. The focusing element is an aspherical lens. The focusing element has a second surface shape and is configured to converge the collimated flat-top beam into a target filamentary beam. The second surface shape is determined based on the flat-top beam diameter information and the second beam energy distribution information on the input surface of the focusing element, as well as the desired depth of focus and the peak energy distribution information along the optical axis within the depth of focus range. The laser beam emitted by the laser is converted into a flat-top beam by a shaping element, and its divergence angle is controlled by a collimating element. Finally, it is focused by a focusing element into a high-energy-utilization, highly uniform target filamentation beam. This filamentation beam can achieve laser cutting of hard and brittle materials, improving processing results. At the same time, the filamentation cutting head uses a fully refractive element, which not only has the advantages of simple design method, low lens processing difficulty, and the ability to handle a variety of materials, but also can convert the Gaussian beam into a flat-top beam, utilizing all the input energy for the filamentation beam. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the specific embodiments of this disclosure or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0036] Figure 1 is a schematic diagram of the structure of a filament cutting head provided in an embodiment of this disclosure;

[0037] Figure 2 is a schematic diagram of a laser cutting system provided in an embodiment of this disclosure;

[0038] Figure 3 is a flowchart illustrating a filament cutting head design method provided in an embodiment of this disclosure;

[0039] Figure 4 is a schematic diagram of the flat-top effect of converting a Gaussian beam into a flat-top beam according to an embodiment of this disclosure;

[0040] Figure 5 is a schematic diagram of the collimation effect of converting a flat-top beam into a collimated beam according to an embodiment of this disclosure;

[0041] Figure 6 is a schematic diagram of the axial peak energy distribution within the focal depth range provided by an embodiment of this disclosure;

[0042] Figure 7 is a schematic diagram of cross-sectional energy distribution within the focal depth range provided by an embodiment of this disclosure.

[0043] Icons: 101-Shaping element; 102-Collimating element; 103-Focusing element; 201-Laser; 202-Beam expander; 203-Reflector. Detailed Implementation

[0044] The technical solutions of this disclosure will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of this disclosure, not all embodiments. Based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0045] In existing technologies, laser cutting heads configured for cutting hard and brittle products primarily utilize diffraction optics theory and polarization / diffraction optical elements to guide a Gaussian beam through a system similar to an axial conical mirror, and then a focusing objective lens to form an axial beam with the desired depth of focus and energy distribution. Specifically, the first mirror is a polarization element used to adjust the beam's polarization state; the second mirror is a diffraction element that receives a fixed polarization state to obtain the desired spot state; and the third mirror is a focusing objective lens that focuses the beam into an axial beam with the desired depth of focus and energy distribution.

[0046] The above-mentioned approach has the following drawbacks: Due to the complexity of diffraction optics theory and the difficulty of manufacturing diffraction optical elements, the debugging difficulty and device price are usually much higher than those of refractive elements. At the same time, due to the variability of materials, different materials have different polarization requirements, which often conflict with the cutting head designed and manufactured based on polarization optics. In addition, because it is a Gaussian beam converted into a Bessel beam, the energy below half-width of the Gaussian beam usually cannot be controlled as an effective cutting depth region, which reduces the energy utilization rate of the cutting head.

[0047] Based on this, the present disclosure provides a filamentation cutting head, a laser cutting system, and a filamentation cutting head design method. The filamentation cutting head is composed of fully refractive elements, which not only has the advantages of simple design method, low lens processing difficulty, and adaptability to various materials, but also can convert the entire Gaussian beam into a flat-top beam, utilizing all input energy for the filamentation beam, resulting in a filamentation beam with high energy utilization and high uniformity. This filamentation beam is suitable for laser cutting of hard and brittle materials such as sapphire, and can improve the processing effect of hard and brittle materials.

[0048] It should be noted that the aforementioned hard and brittle materials are not limited to sapphire, but can also be materials such as glass or ceramics.

[0049] To facilitate understanding of this embodiment, a filament cutting head disclosed in this disclosure will first be described in detail.

[0050] As shown in Figure 1, this embodiment of the present disclosure provides a filament cutting head, including a shaping element 101, a collimating element 102 and a focusing element 103 arranged sequentially along the direction of light propagation.

[0051] The shaping element 101 is an aspherical lens. The shaping element 101 has a first surface profile, configured to convert an input non-flat-top beam into a flat-top beam output. The first surface profile is determined based on the first beam energy distribution information on the input surface of the shaping element 101, as well as the desired beam propagation distance and the desired flat-top beam energy distribution information. The input non-flat-top beam can be, but is not limited to, a Gaussian beam. The Gaussian beam can be emitted by an ultrafast laser, such as an infrared laser generating an ideal Gaussian beam. The first beam energy distribution information can be the energy distribution information of the Gaussian beam emitted by the laser, and can include the energy intensity of the Gaussian beam at each location, represented in matrix form. The first beam energy distribution information, the desired beam propagation distance, and the desired flat-top beam energy distribution information are all preset by the user.

[0052] Collimating element 102 is configured to collimate the input flat-top beam; the distance between collimating element 102 and shaping element 101 is consistent with the desired beam propagation distance. Here, "consistent" means that the distance between collimating element 102 and shaping element 101 is within a range centered on the desired beam propagation distance. This range can be set according to actual needs and is not limited here. For example, if the desired beam propagation distance is 150mm, the distance between collimating element 102 and shaping element 101 can be between 145mm and 155mm. Collimating element 102 can be a plano-convex lens or an aspherical lens; plano-convex lenses are less expensive.

[0053] The focusing element 103 is an aspherical lens. The focusing element 103 has a second surface profile configured to converge the collimated flat-top beam into a target filamentary beam. The second surface profile is determined based on the flat-top beam diameter information and the second beam energy distribution information on the input surface of the focusing element 103, as well as the desired depth of focus and the peak energy distribution information along the optical axis within the depth of focus range. Depth of focus refers to the distance between points of focus that the lens can focus on while maintaining acceptable sharpness. The depth of focus range refers to the distance from the nearest point of sharpness to the farthest point of sharpness. The flat-top beam diameter information, the second beam energy distribution information, the desired depth of focus, and the peak energy distribution information are all preset by the user. The flat-top beam diameter information and the second beam energy distribution information correspond to the desired flat-top beam energy distribution information and can be determined by the desired flat-top beam energy distribution information and the beam conversion relationship corresponding to the collimating element 102.

[0054] The distance between the focusing element 103 and the collimating element 102 can be set by considering factors such as size, weight, installation, and drawing design. Optionally, the distance between the focusing element 103 and the collimating element 102 can be between 0.5mm and 3mm. For example, the distance between the focusing element 103 and the collimating element 102 can be 1mm. This facilitates both the installation of the focusing element 103 and the collimating element 102 and the drawing design.

[0055] The center positions of the aforementioned shaping element 101, collimating element 102 and focusing element 103 are all aligned with the optical axis, which ensures the quality of the output filamentary beam.

[0056] In one possible implementation, the Gaussian beam generated by the infrared laser passes through the shaping element 101 and is transformed into a flat-top beam after traveling a certain distance (i.e., the desired beam propagation distance) based on beam propagation theory; then the divergence angle of its emission is controlled by the collimating element 102, and finally it is converged into a filamentary beam with high energy utilization and high uniformity by the focusing element 103.

[0057] The key features of this embodiment are the performance characteristics and usage methods of the three elements. The shaping element 101 can convert the Gaussian beam into a flat-top beam to ensure high energy utilization and high uniformity of axial energy distribution. The collimating element 102 can convert the beam entering the focusing element 103 into a collimated beam. The focusing element 103 plays a converging role, ultimately forming a filamentation beam with high energy utilization and high uniformity.

[0058] For the aforementioned filament cutting head, the laser beam emitted by the laser is converted into a flat-top beam by the shaping element 101, and then its divergence angle is controlled by the collimation element 102. Finally, it is focused by the focusing element 103 into a target filament beam with high energy utilization and high uniformity. This filament beam can realize laser cutting of hard and brittle materials and improve the processing effect. At the same time, the shaping element 101, the collimation element 102 and the focusing element 103 are all refractive elements, that is, the filament cutting head adopts a fully refractive element. It not only has the advantages of simple design method, low lens processing difficulty and the ability to deal with a variety of materials, but also can convert the Gaussian beam into a flat-top beam and utilize all the input energy for the filament beam.

[0059] Optionally, the aforementioned filament cutting head further includes a controller, a beam analyzer, and a transmission device; the beam analyzer and the transmission device are respectively connected to the controller; the beam analyzer is configured to detect beam quality information within the focal depth range of the focusing element 103 and send it to the controller; wherein, the beam quality information includes spot energy distribution information; the controller is configured to control the transmission device to adjust the distance between the shaping element 101 and the collimating element 102 based on the received spot energy distribution information. This achieves automatic adjustment of the target filament beam, ensuring the quality of the target filament beam.

[0060] The aforementioned beam analyzer can be set at the working distance of the filament cutting head, i.e., at the focal point. The beam analyzer can detect the beam energy distribution and beam size at its location, as well as information such as depth of focus. The beam energy distribution information output by the beam analyzer can be configured to adjust the distance between the shaping element 101 and the collimating element 102, and the beam size and depth of focus information can be configured to determine whether the quality of the filament cutting head is up to standard.

[0061] The aforementioned transmission device, under the control of the controller, can drive the shaping element 101 and / or the collimating element 102 to move, thereby adjusting the distance between the shaping element 101 and the collimating element 102. Preferably, the transmission device adjusts the distance between the shaping element 101 and the collimating element 102 by driving the shaping element 101 to move, so that the focusing element 103 does not need to be adjusted subsequently. This adjustment method is simple and quick.

[0062] In one possible implementation, taking the movement of the shaping element 101 driven by the transmission device as an example, the controller is further configured to compare the received spot energy distribution information with the preset standard energy distribution information. When the comparison result is inconsistent, an adjustment command is sent to the transmission device. The transmission device is configured to drive the shaping element 101 to move when it receives the adjustment command, so as to adjust the distance between the shaping element 101 and the collimating element 102.

[0063] In practice, the above consistency comparison process can be implemented as follows: First, calculate the deviation between the received spot energy distribution information and the standard energy distribution information to obtain the energy distribution deviation value; then, determine whether the energy distribution deviation value is less than a preset energy deviation threshold. If it is less, the comparison result is determined to be consistent; otherwise, if it is not less, the comparison result is determined to be inconsistent. The energy deviation threshold can be set according to actual needs and is not limited here.

[0064] When calculating the deviation between the received spot energy distribution information and the standard energy distribution information, the focal region and the peripheral region can be divided.

[0065] As an example, the received light spot energy distribution information is an M×N energy distribution matrix E, where E ij This represents the energy intensity at position (i,j). The standard energy distribution information is represented by the standard energy distribution matrix S, where S... ij This indicates the energy intensity at the corresponding location.

[0066] Let the radius of the focal region be r. To reduce computational complexity, the focal region can be defined as a rectangular area around the center point: (x0-r, x0+r)×(y0-r, y0+r)

[0067] Where (x0, y0) is the position of the center of focus.

[0068] Of course, it can also be defined as other shapes, such as a circle, depending on the actual situation.

[0069] It can calculate the deviation between the received spot energy distribution information and the standard energy distribution information in the focal region. For example, it can calculate the mean squared error (MSE) within the focal region.

[0070] Where, N focus It is the total number of pixels within the focal area.

[0071] Then, the deviation between the received spot energy distribution information and the standard energy distribution information in the peripheral region is calculated. The peripheral region refers to all areas except the focal region. For the peripheral region, the Mean Absolute Error (MAE) can be calculated:

[0072] Where, N outside It represents the total number of pixels within the outer area.

[0073] The deviation values ​​of the focal region and the peripheral region can be combined to obtain the energy distribution deviation value: Total Deviation = w focus ·NSE focus +w outside MAE outside

[0074] Among them, w focus and w outside These are the weighting factors for the focal area and the peripheral area, which can be adjusted according to actual needs. The weighting factor for the focal area can be greater than that for the peripheral area.

[0075] In some embodiments, the weight of the focal region can be 0.9 and the weight of the peripheral region can be 0.1, which means that the deviation value of the focal region is more important.

[0076] Optionally, the transmission device may include a fixed base, a motor, a crank-connecting rod mechanism, a mirror mount, and a guide rail; the motor and the guide rail are fixed on the fixed base, the mirror mount is slidably connected to the guide rail, and the mirror mount is configured to mount the shaping element 101 and / or the collimating element 102; the motor is connected to the mirror mount through the crank-connecting rod mechanism, driving the mirror mount to slide on the guide rail, that is, driving the shaping element 101 or the collimating element 102 to slide on the guide rail, thereby realizing the distance adjustment between the shaping element 101 and the collimating element 102.

[0077] Optionally, the aforementioned beam quality information also includes spot size information and depth of focus information; the controller is further configured to detect the quality of the filament cutting head based on the received spot size information and depth of focus information. This achieves automatic detection of the filament cutting head quality.

[0078] In practice, the quality inspection process of the filament cutting head can be as follows: First, calculate the deviation between the spot size information and the standard spot size, and between the depth of focus information and the standard depth of focus, to obtain the size deviation value and the depth of focus deviation value. Then, compare the size deviation value and the depth of focus deviation value with the preset size threshold and depth of focus threshold, respectively. If the size deviation value is less than the size threshold and the depth of focus deviation value is less than the depth of focus threshold, the quality of the filament cutting head is determined to be qualified; otherwise, if the size deviation value is not less than the size threshold or the depth of focus deviation value is not less than the depth of focus threshold, the quality of the filament cutting head is determined to be unqualified.

[0079] Alternatively, the controller is further configured to issue an alarm when the wire cutting head fails to meet quality standards, such as through one or more of the following methods: audible and visual alarm, SMS, telephone, or email. This allows for timely notification to the user of any quality issues.

[0080] This disclosure also provides a laser cutting system, as shown in FIG2, which includes a laser 201 and the aforementioned filament cutting head; the laser 201 emits a laser beam toward the filament cutting head.

[0081] The laser 201 mentioned above may be, but is not limited to, an infrared laser, and the laser beam may be, but is not limited to, a Gaussian beam.

[0082] Furthermore, in one possible implementation, as shown in Figure 2, a beam expander 202 and a reflector 203 are also provided between the laser 201 and the shaping element 101; the beam expander 202 is configured to expand the laser beam emitted by the laser, that is, to increase the beam diameter; the reflector 203 is configured to change the propagation direction of the expanded laser beam in order to achieve filamentation beam output in a specified direction.

[0083] This disclosure also provides a method for designing a filament cutting head, which is applied to the aforementioned filament cutting head and can be executed by a computer device with data processing capabilities. Referring to Figure 3, a flowchart of a filament cutting head design method is shown. The method mainly includes the following steps S310 to S330:

[0084] Step S310: Obtain the design data of the shaping element and the focusing element corresponding to the filament cutting head.

[0085] The shaping element design data includes the first beam energy distribution information on the input surface of the shaping element, as well as the desired beam propagation distance and the desired flat-top beam energy distribution information. The focusing element design data includes the flat-top beam diameter information and the second beam energy distribution information on the input surface of the focusing element, as well as the desired depth of focus and the peak energy distribution information along the optical axis within the depth of focus range.

[0086] The aforementioned first beam energy distribution information may include the energy intensity of the Gaussian beam at each location, represented in matrix form.

[0087] Step S320: Determine the first surface shape of the shaping element based on the design data of the shaping element.

[0088] In some possible embodiments, the third beam energy distribution information on the output surface of the shaping element can be determined first based on the desired beam propagation distance and the desired flat-top beam energy distribution information; then, the first surface shape of the shaping element can be determined based on the third beam energy distribution information, the first beam energy distribution information, and a plurality of preset first surface shape parameters.

[0089] The first surface profile parameter can include the radius of curvature and the quadratic surface coefficient. In practice, optical design software (such as Matlab and Zemax) can be used to design the shaping element and verify its effect. The shape of the shaping element can be represented by a polynomial function with the first surface profile parameter, such as a Zernike polynomial. Ray tracing software (such as Zemax) can be used to simulate the distribution of the beam after passing through the aspherical lens, and the first surface profile parameter can be adjusted until the desired flat-top beam distribution is achieved. It should be noted that ray tracing software is not limited to Zemax; in other embodiments, software such as LightTools or TracePro can also be used.

[0090] Step S330: Determine the second surface shape of the focusing element based on the focusing element design data.

[0091] In some possible embodiments, the angle information between multiple outgoing rays in the output beam of the focusing element and the optical axis can be determined first based on the desired depth of focus and peak energy distribution information; then, the second surface shape of the focusing element can be determined based on the angle information, the flat-top beam diameter information, the second beam energy distribution information, and multiple preset second surface shape parameters.

[0092] In practice, after obtaining the angle information, the focal depth range can be divided into multiple segments. Each segment can be set with an angle between the outgoing ray and the optical axis. Then, similar to the surface design method of the shaping element, ray tracing can be performed through optical design software to adjust the second surface parameters until the desired focal depth is achieved, thereby finding the optimal curved surface shape.

[0093] It should be noted that there is no specific order of execution between steps S320 and S330. They can be executed in parallel, or step S320 can be executed first and then step S330; or step S330 can be executed first and then step S320.

[0094] This disclosure discloses a high-energy-efficiency, high-uniformity filament cutting head. The laser beam passes through a shaping element, a collimating element, and a focusing element in succession, ultimately forming a high-energy-efficiency, high-uniformity filament beam. It not only has advantages such as simple design concept and easy lens processing, but more importantly, its high energy efficiency and high uniformity can ensure that hard and brittle materials can be cut uniformly. Therefore, this solution can achieve good cutting of hard and brittle materials.

[0095] In one possible implementation, when determining the first surface shape of the shaping element, firstly, the energy distribution of the Gaussian beam is calculated in matrix form to determine the energy intensity at each position (Gaussian beam matrix, i.e., the first beam energy distribution information). Given the desired beam propagation distance (i.e., the desired beam propagation distance) and the flat-top beam energy distribution on the collimating element, which is also represented in matrix form as the energy intensity at each position (flat-top beam matrix, i.e., the desired flat-top beam energy distribution information), the surface shape of the shaping element (i.e., the first surface shape) is then calculated in reverse based on the Gaussian beam matrix, beam propagation distance, and flat-top beam matrix. Once the lens surface shape of the shaping element is confirmed, the desired flat-top beam can be obtained at the collimating element. This beam has a nearly uniform energy across the entire cross-section, as shown in Figure 4 (Figure 4 is obtained through simulation), facilitating the acquisition of a filamentation beam with high energy utilization and high uniformity. In Figure 4, the color of the Y-axis color plot represents the energy intensity; the color of the Y-axis color plot at the observation surface is relatively uniform, indicating that the energy is relatively consistent.

[0096] As shown in Figure 5 (obtained through simulation), the collimating element 102 is a plano-convex lens. The convex surface of the plano-convex lens collimates the diverging flat-top beam, making the beam after passing through the collimating element 102 a parallel and collimated flat-top beam. That is, the diverging beam after passing through the shaping element 101 is compressed into a parallel state after passing through the collimating element 102. Furthermore, along the Y-direction of the beam between the collimating element 102 and the focusing element 103, the beam exhibits a flat-top distribution (the color of the Y-direction color image at the observation surface is relatively uniform, indicating relatively consistent energy). Therefore, by improving the beam divergence angle, it is possible to ensure that the beam incident on the focusing element 103 is a parallel flat-top beam.

[0097] When determining the second surface shape of the focusing element, firstly, based on design requirements, the desired depth of focus along the Z-axis (i.e., the desired focal depth), the angle of each ray segment (i.e., the angle information), and the overall energy distribution (i.e., the peak energy distribution information, as shown in Figure 6, the axial peak energy distribution within the focal depth range) are determined. Referring to the design method of the shaping element, based on the output results (i.e., the desired focal depth, angle information, and peak energy distribution information), the input flat-top beam diameter and energy distribution (i.e., the flat-top beam diameter information and the second beam energy distribution information), the lens surface shape of the focusing element (i.e., the second surface shape) is calculated. The focusing element can converge a flat-top beam into a filamentary beam with high energy utilization and high uniformity through its special surface shape design.

[0098] Optionally, the formulas for the first and second face types are:

[0099] Where z is the aspherical elevation at a fixed Y, Y is the distance extended horizontally from the center of the lens plane in any direction, and R, k, A4, A6, A8, A 10 A 12 A 14 A 16 These are the surface parameters.

[0100] The face parameter values ​​corresponding to the first face and the second face are different (that is, the first face parameter value and the second face parameter value are different). The face parameter values ​​can be obtained through the above process. Thus, the Y value under different Y values ​​can be obtained using the above face formula, that is, the corresponding first face and second face can be obtained.

[0101] The application of the above-mentioned filamentation cutting head is described below using sapphire as an example. The filamentation cutting head designed in this embodiment can be applied to the cutting of sapphire with ink. Typically, a layer of ink adheres to the surface or bottom of the sapphire. It is necessary to cut through the sapphire while maintaining the width of ink removal, as shown in Figure 7 (different colors represent different energy levels). The brightest and most intense spot in the center is the 0th order light, configured for sapphire cutting; the annular region around the 0th order beam represents the sidelobe energy, configured for sapphire ink removal. For example, when the filamentation beam acts on the upper surface of the sapphire at Z0.3mm, the distance from the cutting point to the ink edge is 55µm (µm in this text refers to micrometers), meaning that 55µm of ink is removed; similarly, at Z0.4mm, 40µm of ink is removed; and at Z0.5mm, 25µm of ink is removed.

[0102] The laser cutting system and filament cutting head design method provided in this embodiment have the same implementation principle and technical effects as the aforementioned filament cutting head embodiment. For the sake of brevity, any parts not mentioned in the embodiment of the laser cutting system and filament cutting head design method can be referred to the corresponding content in the aforementioned filament cutting head embodiment.

[0103] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0104] Furthermore, in the description of the embodiments of this disclosure, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this disclosure based on the specific circumstances.

[0105] In the description of this disclosure, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this disclosure and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this disclosure. Furthermore, the terms "first," "second," and "third" are configured for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0106] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this disclosure, and are not intended to limit them. Although this disclosure has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this disclosure. Industrial applicability

[0107] In summary, this disclosure provides a filament cutting head, a laser cutting system, and a filament cutting head design method to achieve a filament beam with high energy utilization and high uniformity, thereby improving processing results.

Claims

1. A filament cutting head, characterized in that, It includes a shaping element, a collimating element, and a focusing element arranged sequentially along the direction of light propagation; The shaping element is an aspherical lens; the shaping element has a first surface profile and is configured to convert the input non-flat-top beam into a flat-top beam output; the first surface profile is determined based on the first beam energy distribution information on the input surface of the shaping element, as well as the desired beam propagation distance and the desired flat-top beam energy distribution information; The collimating element is configured to collimate the input flat-top beam; the distance between the collimating element and the shaping element is consistent with the desired beam propagation distance; The focusing element is an aspherical lens; the focusing element has a second surface profile, configured to converge the collimated flat-top beam into a target filamentary beam; the second surface profile is determined based on the flat-top beam diameter information and the second beam energy distribution information on the input surface of the focusing element, as well as the desired depth of focus and the peak energy distribution information along the optical axis within the depth of focus range.

2. The filament cutting head according to claim 1, characterized in that, The filament cutting head also includes a controller, a beam analyzer, and a transmission device; the beam analyzer and the transmission device are respectively connected to the controller. The beam analyzer is configured to detect beam quality information within the focal depth range of the focusing element and send it to the controller; wherein, the beam quality information includes beam energy distribution information; The controller is configured to control the transmission device to adjust the distance between the shaping element and the collimating element based on the received light spot energy distribution information.

3. The filament cutting head according to claim 2, characterized in that, The controller is also configured to compare the received light spot energy distribution information with preset standard energy distribution information, and when the comparison result is inconsistent, send an adjustment command to the transmission device. The transmission device is configured to move the shaping element when it receives the adjustment command, so as to adjust the distance between the shaping element and the collimating element.

4. The filament cutting head according to claim 2 or 3, characterized in that, The transmission device includes a fixed base, a motor, a crank-connecting rod mechanism, a mirror base, and a guide rail; The motor and the guide rail are fixed on the fixed base, the mirror mount is slidably connected to the guide rail, and the mirror mount is configured to install the shaping element and / or the collimating element; the motor is connected to the mirror mount through the crank-connecting rod mechanism, driving the mirror mount to slide on the guide rail.

5. The filament cutting head according to any one of claims 2-4, characterized in that, The beam quality information also includes spot size information and depth of focus information; the controller is further configured to detect the quality of the filament cutting head based on the received spot size information and depth of focus information.

6. A laser cutting system, characterized in that, It includes a laser and a filament cutting head according to any one of claims 1-5; the laser emits a laser beam toward the filament cutting head.

7. A method for designing a filament cutting head, characterized in that, The method is applied to the filament cutting head according to any one of claims 1-5; the method includes: Obtain the shaping element design data and focusing element design data corresponding to the filament cutting head; wherein, the shaping element design data includes the first beam energy distribution information on the input surface of the shaping element, as well as the desired beam propagation distance and the desired flat-top beam energy distribution information, and the focusing element design data includes the flat-top beam diameter information and the second beam energy distribution information on the input surface of the focusing element, as well as the desired depth of focus and the peak energy distribution information along the optical axis within the depth of focus; Based on the design data of the shaping element, the first surface shape of the shaping element is determined; Based on the design data of the focusing element, the second surface shape of the focusing element is determined.

8. The method according to claim 7, characterized in that, The step of determining the first surface shape of the shaping element based on the design data of the shaping element includes: Based on the desired beam propagation distance and the desired flat-top beam energy distribution information, the energy distribution information of the third beam on the output surface of the shaping element is determined; The first surface shape of the shaping element is determined based on the third beam energy distribution information, the first beam energy distribution information, and a plurality of preset first surface shape parameters.

9. The method according to claim 7 or 8, characterized in that, The step of determining the second surface shape of the focusing element based on the focusing element design data includes: Based on the desired depth of focus and the peak energy distribution information, the angle information between multiple outgoing rays in the output beam of the focusing element and the optical axis is determined; The second surface shape of the focusing element is determined based on the included angle information, the flat-top beam diameter information, the second beam energy distribution information, and a plurality of preset second surface shape parameters.

10. The method according to any one of claims 7-9, characterized in that, The first beam energy distribution information includes the energy intensity of the Gaussian beam at each location, represented in matrix form; the surface shape formulas corresponding to the first and second surface shapes are: Where z is the aspherical elevation at a fixed Y, Y is the distance extended horizontally from the center of the lens plane in any direction, and R, k, A4, A6, A8, A 10 A 12 A 14 A 16 These are the surface parameters.

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