Laser cleaning system and working method and design method thereof
By using a long focal depth line laser cleaning optical path system, the problem of fixed focal plane position in laser cleaning optical path systems has been solved, achieving stable cleaning effect and high efficiency in complex scenarios, and is suitable for various industrial scenarios.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- QILU ZHONGKE INST OF OPTICAL PHYSICS & ENG TECH
- Filing Date
- 2026-03-31
- Publication Date
- 2026-05-19
AI Technical Summary
Existing laser cleaning optical path systems have a fixed focal plane position, resulting in poor adaptability to the depth of focus and working distance range. This makes it difficult to maintain a stable cleaning effect in complex scenarios, especially in high-precision scenarios such as aero-engine blades and electronic chip packaging, where there are problems of uneven cleaning and low efficiency.
A long focal depth line laser cleaning optical path system is adopted. By combining an aspherical light source collimating lens, an off-axis parabolic cylindrical mirror, a convex cylindrical lens, a concave cylindrical lens, and a pyramidal-cylindrical orthogonal compound mirror, the custom focal depth and long working distance of the beam can be achieved, reducing system complexity and cost.
It maintains the consistency of laser cleaning results over a longer period of time, improves cleaning efficiency and accuracy, is suitable for integrated production and industrial applications, and reduces the sensitivity of the focusing process.
Smart Images
Figure CN122057746A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a laser cleaning system and its working and design methods, belonging to the technical field of laser applications. Background Technology
[0002] In the field of industrial surface treatment, laser cleaning technology, with its core advantages of being non-contact, pollution-free, and highly precise, is gradually replacing traditional chemical cleaning, sandblasting, and mechanical grinding methods, becoming the mainstream direction for environmentally friendly precision cleaning. Compared to traditional cleaning methods, laser cleaning requires no chemical agents or abrasive consumables, produces no waste liquid or dust emissions, and can fundamentally prevent substrate corrosion and mechanical damage. It can also achieve micron-level precision cleaning, making it perfectly suitable for diverse materials such as metals, composite materials, and cultural relics. It has wide applications in shipbuilding, automobile manufacturing, precision electronic component processing, and aerospace, while also having lower long-term operating costs, better aligning with "dual carbon" goals and stringent environmental regulations, and has become a core supporting technology for the upgrading of green manufacturing in industry.
[0003] Laser cleaning technology primarily involves two techniques: line spot shaping and galvanometer scanning. In practical applications, the original Gaussian beam output from the laser source is spatially modulated by shaping components such as lens groups and diffractive optical elements (DOEs), transforming the Gaussian beam into a line laser. This expands the effective cleaning area per pass, improving overall processing efficiency while precisely controlling energy distribution to prevent irreversible damage to the substrate from localized overheating. Galvanometer scanning technology mainly consists of a dual-axis galvanometer unit, a telecentric scanning field mirror, and an intelligent control module. It can adjust parameters such as scanning speed, spot size, and laser power according to actual needs, adapting to cleaning tasks of different specifications and scenarios, ensuring accuracy and consistency in cleaning, whether for regular planar surfaces or complex curved surfaces.
[0004] However, current laser cleaning optical path systems have a fixed focal plane position, resulting in poor adaptability to the depth of focus and working distance range, which restricts their widespread application in complex scenarios. In handheld laser cleaning or cleaning of irregular parts, factors such as manual grip deviation, changes in workpiece surface curvature, and slight equipment vibration can easily cause fluctuations in the working distance. Once the focal depth range is exceeded, it directly leads to problems such as larger spot size and reduced energy density, resulting in uneven cleaning effects and contaminant residue. Especially in scenarios with extremely high cleaning precision requirements, such as cleaning aero-engine blades and electronic chip packaging, the limitations of existing technology are even more pronounced. Carbon deposits, oil stains, and other contaminants on the surface of aero-engine blades need to be thoroughly removed without causing any damage to the blade surface; however, due to the complex curved structure of the blade surface, existing laser cleaning optical path systems struggle to maintain a stable cleaning effect across the entire blade surface, often requiring multiple adjustments to the working distance or the use of multi-station cleaning, which greatly reduces work efficiency. Electronic chip packaging cleaning places higher demands on cleaning precision and efficiency. Even tiny contaminant residues on the chip surface can cause chip failure. Existing technologies are prone to incomplete or over-cleaning when dealing with the complex wiring and packaging structures on the chip surface.
[0005] Chinese patent CN207126928U discloses an automated laser cleaning device. This system achieves automatic Z-axis focusing of the laser cleaning head through "image recognition + ranging feedback". However, although this method can solve the focusing problem to a certain extent, it significantly increases the system complexity and manufacturing cost, while also prolonging the focusing response time and reducing the overall cleaning efficiency, making it difficult to meet the industrial needs of high-efficiency batch cleaning.
[0006] Therefore, developing a linear laser cleaning optical path system capable of achieving long focal depth and working distance range while reducing working distance sensitivity is key to overcoming the technological bottlenecks in the laser cleaning industry. This system must not only address the issues of fixed focal plane position and poor adaptability to focal depth and working distance ranges in existing laser cleaning optical path systems, but also reduce system complexity and manufacturing costs while ensuring cleaning accuracy and effectiveness, thereby improving cleaning efficiency to meet the industrial cleaning needs of different fields and scenarios. The research and application of this technology will further promote the popularization and development of laser cleaning technology in the field of industrial surface treatment, providing stronger technical support for the upgrading of green manufacturing in industry. Summary of the Invention
[0007] To address the shortcomings of existing technologies, this invention provides a laser cleaning system.
[0008] The present invention also provides a working method and a design method for the above-mentioned laser cleaning system.
[0009] Invention Summary: This invention proposes a long-working-range line laser cleaning optical path system, solving the problem of uneven laser cleaning effect caused by the fixed focal plane position of the laser beam. The optical path system is simple, easy to integrate, and can be practically applied to various industrial scenarios.
[0010] The technical solution of this invention is as follows: A laser cleaning system includes a point light source, an aspherical light source collimating lens, an off-axis parabolic cylindrical reflector, a convex cylindrical lens, a concave cylindrical lens, and a pyramidal-cylindrical orthogonal composite mirror arranged sequentially along the optical path. The focal depth of a beam focused by a typical spherical lens is on the order of hundreds of micrometers, corresponding to the "hundred-micrometer level". Bessel beams can achieve a custom focal depth through shaping, which is collectively referred to as long focal depth by those skilled in the art.
[0011] A point light source forms a collimated beam after passing through an aspherical collimating lens. The optical axis of the collimated beam is the first optical axis and is parallel to the horizontal axis of the three-dimensional coordinate system. After passing through an off-axis parabolic cylindrical mirror, the first optical axis is folded by 90° to form a second optical axis, which is parallel to the vertical axis of the three-dimensional coordinate system. The first optical axis and the second optical axis are parallel to the "horizontal axis-vertical axis" plane; the principal axis of the collimating lens of the aspherical light source coincides with the first optical axis, the principal axis of the off-axis parabolic cylindrical mirror forms an angle of 44.5° with the first optical axis, and the principal axes of the convex cylindrical lens, the concave cylindrical lens, and the pyramidal-cylindrical orthogonal composite mirror coincide with the second optical axis; The pyramidal-cylindrical orthogonal composite mirror is a double-sided irregular mirror, with an incident surface of a cylinder and an exit surface of a cone; the exit surface is formed by two surfaces with included angles of θ. The transmission plane is composed of; The principal axis of the incident surface of the pyramidal-cylindrical orthogonal compound mirror is parallel to the vertical axis of the three-dimensional coordinate system; the principal axis of the off-axis parabolic cylindrical mirror, the edge of the exit surface of the pyramidal-cylindrical orthogonal compound mirror, the principal axis of the convex cylindrical lens, and the principal axis of the concave cylindrical lens are parallel to the horizontal axis of the three-dimensional coordinate system; among them, the principal axis of the incident surface of the pyramidal-cylindrical orthogonal compound mirror is the principal axis of the cylinder corresponding to the cylinder of the pyramidal-cylindrical orthogonal compound mirror; the principal axes of the convex cylindrical lens and the concave cylindrical lens are respectively the principal axes of the cylinders corresponding to the convex and concave cylindrical lenses. The edge of the exit surface of the pyramidal-cylindrical orthogonal compound mirror is a straight line where the two transmission planes intersect.
[0012] Preferably, the point light source is Gaussian light.
[0013] The curvature radius and aspherical coefficient of the collimating lens of the aspherical light source and the off-axis parabolic cylindrical reflector have been optimized. The combination of the two can eliminate the spherical aberration generated during the focusing and refraction of the light beam.
[0014] Preferably, the divergence angle of the point light source is The focal length of the collimating lens for an aspherical light source is The radius of curvature of the reflecting surface of the off-axis parabolic cylindrical mirror is The radius of curvature of the incident surface of the pyramid-cylinder orthogonal composite mirror is If the refractive index of the convex and concave cylindrical lenses is n, then the length L of the line laser spot is: The radius of curvature of the cylindrical surface of the convex cylindrical lens is The radius of curvature of the cylindrical surface of the concave cylindrical lens is Let s be the distance between the intersection of the principal axis and the transmission plane of the convex cylindrical lens and the vertex of the intersection of the principal axis and the curved surface of the off-axis parabolic cylindrical mirror. Then, find the lengths of the convex and concave cylindrical lenses along the transverse axis. , ,satisfy: The effective working range of the line laser extends from the cone surface of the pyramidal-cylindrical orthogonal composite mirror to the maximum working distance D, where D satisfies: The distance between the vertex where the "principal axis-surface" of the off-axis parabolic cylindrical mirror intersects and the vertex where the "principal axis-cylinder" of the pyramid-cylinder orthogonal composite mirror intersects. satisfy: Preferred, The value ranges from 160° to 175°. This data was obtained through experimental design; the larger the angle, the longer the focal depth of the designed Bessel beam.
[0015] Preferably, the method for preparing the pyramidal-cylindrical orthogonal composite mirror includes integral grinding, injection molding, or orthogonal bonding of a cylindrical lens and a prism lens.
[0016] The working method of the laser cleaning system includes the following steps: A point light source forms a collimated beam after passing through an aspherical collimating lens; the collimated beam is then reflected by an off-axis parabolic cylindrical mirror. In the horizontal direction of the three-dimensional coordinate system, the light beam is focused when it passes through the collimating lens of the aspherical light source, diverges when it passes through the off-axis parabolic cylindrical mirror, and remains unchanged after passing through the convex cylindrical lens and the concave cylindrical lens; it is expanded and collimated after passing through the orthogonal compound mirror of the pyramid and cylindrical surfaces. In the vertical direction of the three-dimensional coordinate system, the beam does not change after passing through the off-axis parabolic cylindrical mirror, is reduced after passing through the convex cylindrical lens, is collimated after passing through the concave cylindrical lens, and forms a Bessel beam with a long focal depth after passing through the pyramidal-cylindrical orthogonal compound mirror; finally, within a certain vertical axis length, it forms a line spot with length and width located on the horizontal and vertical axes of the three-dimensional coordinate system, respectively.
[0017] The laser cleaning system is designed through the following steps: Step 1: Based on the divergence angle of the point light source And the collimated beam diameter determines the focal length of the collimating lens (1) for the aspherical light source. And the aperture R; R > collimated beam diameter; ; Step 2: Determine the radius of curvature of the off-axis parabolic cylindrical mirror based on the laser spot length L at the design target centerline. The radius of curvature of the cylindrical surface of a pyramid-cylinder orthogonal composite mirror ; through formula Determine the radius of curvature , The combination of these factors further determines the radius of curvature. , .
[0018] Step 3: Use simulation software or programs to simulate the optical path of the collimating lens for the aspherical light source, the off-axis parabolic cylindrical mirror, and the cylindrical surface of the orthogonal compound mirror of the pyramidal-cylindrical surface, and determine the focal length of the collimating lens for the aspherical light source. And the aperture R and the radius of curvature of the off-axis parabolic cylindrical mirror. The radius of curvature of the cylindrical surface of a pyramid-cylinder orthogonal composite mirror Optimization is performed to eliminate the influence of spherical aberration in the length direction of the line spot; Step 4: Determine the angle between the two transmission planes of the pyramidal-cylindrical orthogonal composite mirror cone surface based on the effective working range D of the laser at the design target centerline. ; Step 5: Determine the radius of curvature, length, and width of the convex and concave cylindrical lenses based on the width requirements of the laser beam in the design target.
[0019] The formulas for calculating the parameters in the above steps can all be derived from the formulas mentioned above, and the variations of the formulas will not be repeated here.
[0020] The beneficial effects of this invention are as follows: 1. This invention uses beam shaping to keep the laser action distance within a long range, achieving the same laser cleaning effect within this range. This solves the problem of uneven cleaning effect caused by the fixed focal position of the traditional laser cleaning optical path and defocusing during operation. 2. This invention uses an aspherical light source collimating lens in combination with an off-axis parabolic cylindrical reflector to minimize spherical aberration caused by beam shaping along the transverse axis; and reduces the space occupied by the optical path by using a pyramidal-cylindrical orthogonal composite mirror, thereby reducing the amount of fixed fixtures in the optical system and effectively lowering costs. 3. The optical path of this invention is simple and highly stable, making it suitable for integrated production and industrial applications. Attached Figure Description
[0021] Figure 1 This is a front view (longitudinal view) of the long working range line laser cleaning optical path system described in this invention. Figure 2 This is a front view (horizontal view) of the long working range line laser cleaning optical path system described in this invention. Figure 3 This is a dimensional diagram (longitudinal view) of the long working range line laser cleaning optical path system described in this invention. Figure 4 This is a dimensional diagram (horizontal view) of the long working range line laser cleaning optical path system described in this invention. Figure 5 This is a light intensity distribution diagram of the Bessel beam output by this invention in the "vertical axis-vertical axis" cross section; In the diagram: 1-Aspherical light source collimating lens, 2-Off-axis parabolic cylindrical reflector, 3-Convex cylindrical lens, 4-Concave cylindrical lens, 5-Pyramidal-cylindrical orthogonal composite mirror. Detailed Implementation
[0022] The following describes some embodiments of the present invention in detail with reference to the accompanying drawings.
[0023] Example 1 like Figure 1 , Figure 2 As shown.
[0024] A laser cleaning system includes a point light source, an aspherical light source collimating lens (1), an off-axis parabolic cylindrical reflector (2), a convex cylindrical lens (3), a concave cylindrical lens (4), and a pyramidal-cylindrical orthogonal composite mirror (5) arranged sequentially along the optical path. After passing through the collimating lens (1) of the aspherical light source, the point light source forms a collimated beam. The optical axis of the collimated beam is the first optical axis and is parallel to the horizontal axis of the three-dimensional coordinate system. After passing through the off-axis parabolic cylindrical reflector (2), the first optical axis is folded by 90° to form the second optical axis. The second optical axis is parallel to the vertical axis of the three-dimensional coordinate system. The first optical axis and the second optical axis are parallel to the "horizontal axis-vertical axis" plane; the principal axis of the aspherical light source collimating lens (1) coincides with the first optical axis, the principal axis of the off-axis parabolic cylindrical reflector (2) forms an angle of 44.5° with the first optical axis, and the principal axes of the convex cylindrical lens (3), the concave cylindrical lens (4), and the pyramidal-cylindrical orthogonal composite mirror (5) coincide with the second optical axis; The pyramidal-cylindrical orthogonal composite mirror (5) is a double-sided irregular mirror, with its incident surface being a cylinder and its exit surface being a cone; the exit surface is formed by two objects with mutually perpendicular angles. The transmission plane is composed of; The principal axis of the incident surface of the pyramid-cylindrical orthogonal composite mirror (5) is parallel to the vertical axis of the three-dimensional coordinate system; the principal axis of the off-axis parabolic cylindrical mirror (2), the edge of the exit surface of the pyramid-cylindrical orthogonal composite mirror (5), the principal axis of the convex cylindrical lens (3), and the principal axis of the concave cylindrical lens (4) are parallel to the horizontal axis of the three-dimensional coordinate system. In this embodiment, the point light source is Gaussian light. The incident and exit surfaces of the aspherical light source collimating lens (1), the convex cylindrical lens (3), the concave cylindrical lens (4), and the pyramidal-cylindrical orthogonal composite mirror (5) are all coated with anti-reflection films that match the wavelength of the point light source, and the parabolic surface of the off-axis parabolic cylindrical mirror (2) is coated with a reflective film that matches the wavelength of the point light source.
[0025] The working method of the laser cleaning system described in this embodiment includes the following steps: A point light source forms a collimated beam after passing through an aspherical light source collimating lens (1); the collimated beam is reflected by an off-axis parabolic cylindrical mirror (2); In the horizontal direction of the three-dimensional coordinate system, the beam is focused when it passes through the collimating mirror (1) of the aspherical light source, diverges when it passes through the off-axis parabolic cylindrical mirror (2), and does not change after passing through the convex cylindrical lens (3) and the concave cylindrical lens (4); it is expanded and collimated after passing through the pyramidal-cylindrical orthogonal composite mirror (5). In the vertical direction of the three-dimensional coordinate system, the beam does not change after passing through the off-axis parabolic cylindrical mirror (2), is contracted after passing through the convex cylindrical lens (3), collimated after passing through the concave cylindrical lens (4), and forms a Bessel beam with a long focal depth after passing through the pyramidal-cylindrical orthogonal compound mirror (5); finally, within a certain vertical axis length, a line spot with length and width located on the horizontal and vertical axes of the three-dimensional coordinate system is formed. Figure 5 As shown, this is the Bessel beam with a long focal depth working range output by the present invention.
[0026] Example 2 like Figure 3 , Figure 4 As shown.
[0027] As described in Example 1, in the laser cleaning system, the divergence angle of the point light source is further... The focal length of the collimating lens (1) for the aspherical light source is The radius of curvature of the reflecting surface of the off-axis parabolic cylindrical mirror (2) is... The radius of curvature of the incident surface of the pyramid-cylindrical orthogonal composite mirror (5) is... If the refractive index of the convex cylindrical lens (3) and the concave cylindrical lens (4) is n, then the length L of the line laser spot is: This embodiment , , , , ,but: The cylindrical radius of curvature of the convex cylindrical lens (3) is The radius of curvature of the cylindrical surface of the concave cylindrical lens (4) is If the distance s is the distance between the intersection of the principal axis and the transmission plane of the convex cylindrical lens (3) and the vertex of the intersection of the principal axis and the curved surface of the off-axis parabolic cylindrical mirror (2), then the lengths of the convex cylindrical lens (3) and the concave cylindrical lens (4) in the transverse direction are as follows: , ,satisfy: This embodiment , , ,but: The effective working range of the line laser is within the range from the cone surface of the pyramid-cylinder orthogonal composite mirror (5) to the maximum working distance D, where D satisfies: The value range is 160° to 175°, in this embodiment. , The distance between the vertices where the off-axis parabolic cylindrical mirror (2) intersects the principal axis and the curved surface and the vertices where the pyramidal-cylindrical composite mirror (5) intersects the principal axis and the cylindrical surface. satisfy: In this embodiment The laser cleaning system described in this embodiment can achieve a uniform laser cleaning effect for line spots with a length of 50mm within a range of 200mm.
[0028] The laser cleaning system described in this embodiment is designed through the following steps: Step 1: Based on the divergence angle of the point light source And the collimated beam diameter determines the focal length of the collimating lens (1) for the aspherical light source. And the aperture R; R > collimated beam diameter; ; Step 2: Determine the radius of curvature of the off-axis parabolic cylindrical reflector (2) based on the laser spot length L at the design target centerline. , Pyramidal-cylindrical orthogonal composite mirror (5) Radius of curvature of the cylindrical surface ; Step 3: Use simulation software or program to simulate the optical path of the aspherical light source collimating lens (1), the off-axis parabolic cylindrical mirror (2), and the cylindrical surface of the pyramidal-cylindrical orthogonal composite mirror (5), and simulate the focal length of the aspherical light source collimating lens (1). And the light-transmitting aperture R, the radius of curvature of the off-axis parabolic cylindrical mirror (2) , Pyramidal-cylindrical orthogonal composite mirror (5) Radius of curvature of the cylindrical surface Optimization is performed to eliminate the influence of spherical aberration in the length direction of the line spot; Step 4: Determine the angle between the two transmission planes of the pyramid-cylinder orthogonal composite mirror (5) based on the effective working range D of the laser at the design target centerline. ; Step 5: Determine the radius of curvature, lens length, and width of the convex cylindrical lens (3) and concave cylindrical lens (4) according to the width requirement of the laser in the design target.
[0029] Example 3 As described in Example 1, the laser cleaning system is further described in the following way: the preparation method of the pyramid-cylindrical orthogonal composite mirror (5) includes integral grinding, injection molding, or orthogonal bonding of cylindrical lens and prism lens; the pyramid-cylindrical orthogonal composite mirror (5) in this embodiment is obtained by injection molding.
Claims
1. A laser cleaning system, characterized in that, The system includes a point source, an aspherical collimating lens, an off-axis parabolic cylindrical mirror, a convex cylindrical lens, a concave cylindrical lens, and a pyramidal-cylindrical orthogonal compound mirror arranged sequentially along the optical path. The point source, after passing through the aspherical collimating lens, forms a collimated beam with its optical axis being the first optical axis and parallel to the horizontal axis of the three-dimensional coordinate system. After passing through the off-axis parabolic cylindrical mirror, the first optical axis is deflected by 90° to form a second optical axis, which is parallel to the vertical axis of the three-dimensional coordinate system. The first and second optical axes are parallel to the horizontal-vertical plane. The principal axis of the aspherical collimating lens coincides with the first optical axis, the principal axis of the off-axis parabolic cylindrical mirror forms a 44.5° angle with the first optical axis, and the principal axes of the convex cylindrical lens, concave cylindrical lens, and pyramidal-cylindrical orthogonal compound mirror coincide with the second optical axis. The pyramidal-cylindrical orthogonal compound mirror is a double-sided irregular mirror with an incident surface that is cylindrical and an exit surface that is conical. The exit surface is formed by two objects at an angle of θ. The transmission plane is composed of the following: the principal axis of the incident surface of the pyramid-cylindrical orthogonal composite mirror is parallel to the vertical axis of the three-dimensional coordinate system; the principal axis of the off-axis parabolic cylindrical mirror, the edge of the exit surface of the pyramid-cylindrical orthogonal composite mirror, the principal axis of the convex cylindrical lens, and the principal axis of the concave cylindrical lens are parallel to the horizontal axis of the three-dimensional coordinate system.
2. The laser cleaning system according to claim 1, characterized in that, The divergence angle of the point light source is The focal length of the collimating lens for an aspherical light source is The radius of curvature of the reflecting surface of the off-axis parabolic cylindrical mirror is The radius of curvature of the incident surface of the pyramid-cylinder orthogonal composite mirror is If the refractive index of the convex and concave cylindrical lenses is n, then the length L of the line laser spot is: ， The radius of curvature of the cylindrical surface of the convex cylindrical lens is The radius of curvature of the cylindrical surface of the concave cylindrical lens is Let s be the distance between the intersection of the principal axis and the transmission plane of the convex cylindrical lens and the vertex of the intersection of the principal axis and the curved surface of the off-axis parabolic cylindrical mirror. Then, the lengths of the convex and concave cylindrical lenses along the transverse axis are: , ,satisfy: ， ， The effective working range of the line laser extends from the cone surface of the pyramidal-cylindrical orthogonal composite mirror to the maximum working distance D, where D satisfies: ， The distance between the vertex where the "principal axis-surface" of the off-axis parabolic cylindrical mirror intersects and the vertex where the "principal axis-cylinder" of the pyramidal-cylindrical orthogonal composite mirror intersects. satisfy: 。 3. The laser cleaning system according to claim 2, characterized in that, The value range is 160° to 175°.
4. The laser cleaning system according to claim 1, characterized in that, The preparation method of the pyramid-cylindrical orthogonal composite mirror includes integral grinding, injection molding, or orthogonal bonding of cylindrical lens and prism lens.
5. The operating method of the laser cleaning system according to any one of claims 1-4, characterized in that, The steps include the following: A point light source forms a collimated beam after passing through an aspherical collimating lens; the collimated beam is then reflected by an off-axis parabolic cylindrical mirror. In the horizontal direction of the three-dimensional coordinate system, the light beam is focused when it passes through the collimating lens of the aspherical light source, diverges when it passes through the off-axis parabolic cylindrical mirror, and remains unchanged after passing through the convex cylindrical lens and the concave cylindrical lens; it is expanded and collimated after passing through the orthogonal compound mirror of the pyramid and cylindrical surfaces. In the vertical direction of the three-dimensional coordinate system, the beam does not change after passing through the off-axis parabolic cylindrical mirror, is reduced after passing through the convex cylindrical lens, is collimated after passing through the concave cylindrical lens, and forms a Bessel beam with a long focal depth after passing through the pyramidal-cylindrical orthogonal compound mirror; finally, within a certain vertical axis length, it forms a line spot with length and width located on the horizontal and vertical axes of the three-dimensional coordinate system, respectively.
6. The laser cleaning system according to claim 2, characterized in that, Designed using the following steps: Step 1: Based on the divergence angle of the point light source And the collimated beam diameter determines the focal length of the collimating lens for the aspherical light source. And the aperture R; R > collimated beam diameter; ； Step 2: Determine the radius of curvature of the off-axis parabolic cylindrical mirror based on the laser spot length L at the design target centerline. The radius of curvature of the cylindrical surface of a pyramid-cylinder orthogonal composite mirror ; Step 3: Use simulation software or programs to simulate the optical path of the collimating lens for the aspherical light source, the off-axis parabolic cylindrical mirror, and the cylindrical surface of the orthogonal compound mirror of the pyramidal-cylindrical surface, and determine the focal length of the collimating lens for the aspherical light source. And the aperture R and the radius of curvature of the off-axis parabolic cylindrical mirror. The radius of curvature of the cylindrical surface of a pyramid-cylinder orthogonal composite mirror Optimization is performed to eliminate the influence of spherical aberration in the length direction of the line spot; Step 4: Determine the angle between the two transmission planes of the pyramidal-cylindrical orthogonal composite mirror cone surface based on the effective working range D of the laser at the design target centerline. ; Step 5: Determine the radius of curvature, length, and width of the convex and concave cylindrical lenses based on the width requirements of the laser beam in the design target.