A 360-degree reflective free-form surface shaping laser module and a design and manufacturing method of a free-form surface reflector therein

Abstract

The present invention relates to a 360-degree reflective free-form surface shaping laser module, which comprises a lens barrel, a laser light source base is arranged at one end of the lens barrel, a semiconductor laser is arranged at the laser light source base, the light generated by the semiconductor laser is injected into the lens barrel and the axis of the light coincides with the axis of the lens barrel, a lens mounting seat is arranged at the middle of the lens barrel, a lens is arranged at the lens mounting seat, a free-form surface reflector and a reflector mounting seat for positioning and mounting the free-form surface reflector are arranged at one end of the lens barrel away from the laser light source base, a composite quartz tube is arranged on the side of the lens barrel close to the reflector mounting seat, the bottom surface of the free-form surface reflector is elliptical, and a light divergence area and a light convergence area are arranged on the reflection surface of the free-form surface reflector. The present invention has the effect of redistributing unevenly distributed laser light after reflection while improving the utilization rate of laser energy.

Description

Technical Field

[0001] The present invention relates to the field of laser shaping, and in particular to a 360-degree reflective free-form surface shaping laser module and a design and manufacturing method of a free-form surface reflector therein. Background Art

[0002] At present, laser marking instruments are widely used in the measurement of horizontal and vertical reference planes in engineering construction and mechanical processing, or in the measurement of top and ground reference points.

[0003] In the prior art, a Chinese utility model patent with a publication number of CN207585611U discloses a conical mirror for a laser marking instrument, a laser marking assembly, and a laser marking instrument, which are used to simultaneously obtain a laser surface that diffuses 360° in all directions and a laser beam that intersects or is perpendicular to the laser surface. The conical mirror includes: a conical mirror body, and a through hole is provided on the central axis of the mirror body. A laser marking assembly using the above-mentioned conical mirror is also provided, and the laser marking assembly includes: a laser generating assembly, and is applied to the laser marking instrument; the central axis of the mirror body is located on the central axis of the laser beam output by the laser generating assembly.

[0004] The above-mentioned prior art solution has the following defects: in actual use, the light source of the laser marking instrument is generally provided by a semiconductor laser (LD), and due to the characteristics of its own light-emitting principle, the light spot of the semiconductor laser is difficult to form a regular circle. In practice, the divergence angle of the laser beam will have a large difference in the horizontal and vertical directions, resulting in the light spot formed being generally elliptical. In the existing laser module, the reflector at the end is generally a conical reflector with a 45° inclined surface, which is used to reflect the regular vertical circular light spot into a 360° horizontal light. If the elliptical light spot is directly reflected by the reflector, it is easy to cause the power of the reflected light at different angles to be different, resulting in excessive brightness differences at each point.

[0005] Among the existing processing schemes, the common method is to use a circular aperture to intercept the elliptical light spot into a light spot with a smaller diameter, so that the light obtained after reflection tends to be uniform everywhere. However, in actual situations, the aspect ratio of the elliptical light spot is usually between 1:3.5 and 1:4, and the maximum diameter of the circular aperture must be less than or equal to the short axis length of the elliptical light spot, which results in the light spot after passing through the aperture being only 25% to 29% of the original light spot area, causing a huge loss of optical power, resulting in insufficient brightness of the final light. In order to achieve the same brightness, it is necessary to replace the conventional laser light source with a more powerful laser light source. Generally, a laser light source with a power three times that of a conventional laser light source is required, which results in increased costs and increased internal heating of the marking instrument. At the same time, high-power lasers are also prone to greater safety hazards. Summary of the invention

[0006] The purpose of the present invention is to provide a 360-degree reflective free-form surface shaping laser module. By using a 360° free-form surface reflector to replace the ordinary conical metal reflector in the original laser module, it has the advantage of being able to directly reflect the elliptical light spot into light with uniform energy, while greatly reducing the loss of light energy.

[0007] The above technical objectives of the present invention are achieved through the following technical solutions:

[0008] A 360-degree reflective free-form surface shaping laser module comprises a lens barrel, a laser light source base is arranged at one end of the lens barrel, a semiconductor laser is arranged at the laser light source base, light generated by the semiconductor laser is injected into the lens barrel and the axis of the light coincides with the axis of the lens barrel, a lens mounting seat is arranged in the middle of the lens barrel, a lens is arranged at the lens mounting seat, a free-form surface reflector and a reflector mounting seat for positioning and mounting the free-form surface reflector are arranged at one end of the lens barrel away from the laser light source base, a composite quartz tube is arranged on the side of the lens barrel close to the reflector mounting seat, the bottom surface shape of the free-form surface reflector is elliptical, the center of the bottom surface of the free-form surface reflector is located on the axis of the lens barrel, the intersection contour of any plane passing through the axis of the lens barrel and the free-form surface reflector is an approximate triangle and the two sides of any triangle are irregular curves, and a light divergence area and a light convergence area are arranged on the reflection surface of the free-form surface reflector.

[0009] By adopting the above technical solution, the laser light emitted from the semiconductor laser is directly irradiated on the surface of the free-form surface reflector after being converged by the lens, and forms a light spot with an elliptical projection shape on the surface of the free-form surface reflector, and then after being reflected by the free-form surface reflector, it projects a horizontal laser light within a range of 360° through the composite quartz tube. When the laser is emitted from the semiconductor laser, the energy of each point is evenly distributed, so on the elliptical light spot, the energy of each point in the area distributed along the long axis direction of the elliptical light spot is less than the energy of each point in the area distributed along the short axis direction of the elliptical light spot. Therefore, in order to make the elliptical light spot form a light with uniform energy distribution after being reflected by the free-form surface reflector, the basic idea is that the light in the area distributed along the long axis direction of the elliptical light spot needs to be converged after being irradiated on the free-form surface reflector and reflected, so that the energy of the light in this area is increased; the light in the area distributed along the short axis direction of the elliptical light spot needs to be diverged after being irradiated on the free-form surface reflector and reflected, so that the energy of the light in this area is weakened, thereby achieving the effect of laser energy redistribution after reflection. In this process, almost all the light in the laser is directly reflected by the free-form surface reflector and passes through the composite quartz tube. Therefore, compared with the original method of using an aperture to shape the light spot, this type of laser module greatly improves the energy utilization rate of the laser, and through the setting of the light divergence area and the light convergence area, the laser energy is evenly distributed after reflection, which greatly improves the line projection quality of the line projection instrument.

[0010] The present invention is further configured such that the curved surface at the light diverging area is convex outwardly, the curved surface at the light converging area is concave inwardly, two light diverging areas are symmetrically arranged with the straight line where the short axis of the bottom surface of the free-form surface reflector is located as the symmetry axis, and two light converging areas are symmetrically arranged with the straight line where the long axis of the bottom surface of the free-form surface reflector is located as the symmetry axis, and each light diverging area and light converging area is smoothly connected by a curved surface.

[0011] By adopting the above technical solution, in actual operation, when the elliptical spot emitted by the laser is irradiated to the surface of the free-form surface reflector, the long axis length of the spot is about 3 mm, and due to the limitation of the processing method, the long axis length of the bottom surface of the free-form surface reflector is about 12 mm. Therefore, when installing the laser module, it is necessary to place the long axis of the elliptical spot emitted by the semiconductor laser orthogonally to the long axis of the bottom surface of the free-form surface reflector to obtain a better reflection effect. And under this placement method, the area of ​​the elliptical spot along the long axis direction will be distributed in most of the areas distributed along the generatrix direction of the light convergence area, and the area of ​​the elliptical spot along the short axis direction will be distributed in a small part of the area along the generatrix direction of the light divergence area. The area of ​​the elliptical spot along the long axis direction will reduce the width of the light band formed after passing through the light convergence area, and the area of ​​the elliptical spot along the short axis direction will increase the width of the light band formed after passing through the light divergence area, thereby further improving the uniformity of the distribution after laser reflection.

[0012] The present invention is further configured such that the free-form surface reflector is made of a metal material, and the metal material is an alloy material composed of aluminum, copper, steel, and nickel.

[0013] By adopting the above technical solution, the free-form surface reflector made of metal material can greatly reduce the refraction effect produced when light is incident, thereby greatly reducing the energy loss that may exist in the reflection process of light, and the metal material has less processing difficulty and higher processing accuracy.

[0014] The present invention is further configured as follows: the lens barrel includes a fixed section and a connecting sleeve, the lens mounting seat is located in the fixed section, the reflector mounting seat is located at the end of the connecting sleeve away from the laser light source base, a primary limiting ring is formed at the end of the fixed section away from the laser light source base, an internal thread is formed on the inner side wall of the fixed section away from the laser light source base, a secondary limiting ring and an external thread matched with the internal thread are formed on the outer side wall of the connecting sleeve, and the external thread covers the portion from the end of the outer side wall of the connecting sleeve close to the laser light source base to the secondary limiting ring.

[0015] By adopting the above technical solution and setting the connecting sleeve, the user can quickly disassemble and separate the lens mounting seat and the reflector mounting seat, which is convenient for replacing the mirror body and reduces the difficulty of maintenance. The fixed section and the connecting sleeve are connected by threaded connection, which can ensure that the two have high concentricity after installation, thereby improving the accuracy of the laser module.

[0016] The present invention is further configured as follows: a primary base and a secondary base are stacked in sequence on the bottom surface of the free-form surface reflector, the primary base and the secondary base are both circular and concentrically placed, the reflector mounting seat includes a circular base plate and a positioning ring plate located at the edge of the base plate and vertically arranged with the base plate, the positioning ring plate is threadedly fastened to the composite quartz tube, a surface of the secondary limit ring close to the reflector mounting seat is provided with an annular positioning groove, the projection of the secondary base surface excluding the annular part of the primary base on the surface of the secondary limit ring along the axis direction of the lens barrel coincides with the position and shape of the positioning groove.

[0017] By adopting the above technical solution, the concave area formed between the primary base, the secondary base and the positioning ring plate positions one end of the composite quartz tube, and the positioning groove on the secondary limit ring positions the other end of the composite quartz tube. The reflector mounting seat and the composite quartz tube are connected by threaded fastening, which improves the concentricity between the reflector mounting seat and the composite quartz tube during installation. In addition, the reflector mounting seat and the composite quartz tube clamp the primary base, which can effectively improve the structural stability of the free-form surface reflector after installation.

[0018] The present invention is further configured such that the composite quartz tube comprises a quartz tube body and a metal tube body with ports bonded to each other, the metal tube body is located at one end of the quartz tube body away from the connecting sleeve, and the metal tube body is threadedly fastened to the positioning ring plate.

[0019] By adopting the above technical solution, it is difficult to process threads on the surface of the quartz tube body, and it is easy to wear after long-term use. Therefore, a metal tube body connected to the quartz tube body is provided. The technology of processing threads on the surface of the metal tube body is relatively mature and less difficult, and correspondingly it is subject to less wear during use.

[0020] Another object of the present invention is to provide a design and manufacturing method for a free-form surface reflector in a 360-degree reflective free-form surface shaping laser module, which has the effect of constructing a free-form surface on the reflector surface and allowing the light to be redistributed evenly.

[0021] The above technical objectives of the present invention are achieved through the following technical solutions: A method for manufacturing a reflector in a 360-degree reflective free-form surface shaping laser module, comprising the following steps:

[0022] S1: Determine the light intensity distribution formula of the elliptical spot according to the device parameters of the semiconductor laser itself;

[0023] S2: Using the law of reflection of light, establish the relationship between the incident light, the outgoing light and the free-form surface normal vector of the free-form surface reflector. Suppose the unit vector of the incident light is I, the unit vector of the outgoing light is O, the unit vector of the free-form surface normal vector at the reflection point is N, and the angle between O and N is θ, then I+2cosθN=O is satisfied, thereby realizing the redistribution of light energy;

[0024] S3: Using the law of conservation of energy, assuming that there is no energy loss in the process of light refraction through the lens and the free-form surface reflector, and that the absorption of light in the medium is negligible, the light intensity distribution formula of the 360° light ring formed on the regular cylindrical surface after the light is refracted can be obtained based on the light intensity distribution formula obtained in S1, and the light intensity at each point of the light ring is consistent;

[0025] S4: numerically solve the above mathematical model, transform the mathematical model into a set of equations containing several nonlinear equations by the method of differential substitution, and solve them by Newton iteration method. After obtaining several data points, use three-dimensional mapping software to construct a free-form surface, import the free-form surface and the light intensity distribution formula in S1 into the lighting simulation software, obtain the reflected lighting spot on the target surface, sample its illuminance value point by point along the circumference of the spot, and use the energy utilization rate and the average standard deviation of illuminance to quantitatively evaluate the simulated spot results. The evaluation target is energy utilization rate ≥ 90%, and illuminance evaluation standard deviation ≤ 0.1;

[0026] S5: Arrange the surface data that meets the conditions, and process and manufacture according to the surface size data. The processing method is to use a high-precision CNC machine tool and a single-point diamond tool for processing and forming.

[0027] By adopting the above technical scheme, a one-to-one correspondence is established between each incident light ray and its corresponding irradiation point on the target surface. The reflection effect of the free-form surface reflector is theoretically verified and realized through lighting simulation software, and the final reflection effect is evaluated by introducing energy utilization and illumination evaluation standard deviation, so as to obtain a free-form surface that meets the conditions.

[0028] The present invention is further configured such that, in step S4, the number of iterations when solving using the Newton iteration method is 3 to 5 times, and the number of simulated light rays in the lighting simulation software is 3 million.

[0029] By adopting the above technical solution, the surface accuracy after iteration can be improved, and the test accuracy after simulation can be improved.

[0030] The present invention is further configured such that, in step S4, the number of sampling points for point-by-point sampling is 200.

[0031] By adopting the above technical solution, the sampling result can more accurately reflect the actual distribution of light intensity.

[0032] In summary, the present invention has the following beneficial effects:

[0033] 1. Through the setting of free-form surface reflectors, light divergence areas and light convergence areas, it is possible to achieve the effect of redistributing unevenly distributed laser light after reflection while improving the utilization rate of laser energy;

[0034] 2. The setting of the fixed section and the connecting sleeve can improve the structural stability of the laser module;

[0035] 3. The setting of the composite quartz tube can improve the service life of the laser module. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a schematic diagram of the overall internal structure of a 360-degree reflective free-form surface shaping laser module in this embodiment.

[0037] Figure 2 Schematic diagram of the structure of the free-form surface reflector in this embodiment.

[0038] Figure 3 It is a schematic diagram of the light path of the laser light reflected on the surface of the free-form surface reflector in this embodiment.

[0039] In the figure, 1, lens barrel; 11, fixed section; 111, primary limiting ring; 12, connecting sleeve; 121, secondary limiting ring; 122, positioning groove; 2, laser light source base; 21, semiconductor laser; 3, lens mounting seat; 31, lens; 4, reflector mounting seat; 41, free-form reflector; 411, light divergence area; 412, light convergence area; 413, primary base; 414, secondary base; 42, base plate; 43, positioning ring plate; 5, composite quartz tube; 51, quartz tube body; 52, metal tube body. DETAILED DESCRIPTION

[0040] The present invention is further described in detail below in conjunction with the accompanying drawings.

[0041] Reference Figure 1, which is a 360-degree reflective free-form surface shaping laser module disclosed in the present invention, comprises a lens barrel 1, a laser light source base 2 is arranged at one end of the lens barrel 1, a semiconductor laser 21 is arranged at the laser light source base 2, the light generated by the semiconductor laser 21 is injected into the lens barrel 1 and the axis of the light coincides with the axis of the lens barrel 1, a lens 31 mounting seat 3 is arranged in the middle of the lens barrel 1, a lens 31 is arranged at the lens 31 mounting seat 3, a free-form surface reflector 41 and a reflector mounting seat 4 for positioning and mounting the free-form surface reflector 41 are arranged at one end of the lens barrel 1 away from the laser light source base 2, a composite quartz tube 5 is arranged on the side of the lens barrel 1 close to the reflector mounting seat 4, and the composite quartz tube 5 comprises a quartz tube body 51 and a metal tube body 52 whose ports are bonded to each other.

[0042] Reference Figure 1 and Figure 2 The lens barrel 1 includes a fixed section 11 and a connecting sleeve 12. The lens 31 mounting seat 3 is located in the fixed section 11. The reflector mounting seat 4 is located at the end of the connecting sleeve 12 away from the laser light source base 2. A primary limiting ring 111 is formed at the end of the fixed section 11 away from the laser light source base 2. An internal thread is formed on the inner wall of the fixed section 11 away from the laser light source base 2. A secondary limiting ring 121 and an external thread matched with the internal thread are formed on the outer wall of the connecting sleeve 12. The external thread covers the portion from the end of the outer wall of the connecting sleeve 12 close to the laser light source base 2 to the secondary limiting ring 121. A primary base 413 and a secondary base 414 are stacked in sequence on the bottom surface of the free-form surface reflector 41. Both the primary base 413 and the secondary base 414 are circular and concentrically placed. The primary base 413, the secondary base 414 and the free-form surface reflector 41 can be connected by bonding, and the three can also be manufactured in an integrated molding manner. The reflector mounting seat 4 includes a circular base plate 42 and a positioning ring plate 43 located at the edge of the base plate 42 and arranged perpendicularly to the base plate 42. The positioning ring plate 43 is threadedly connected to the composite quartz tube 5. A circular positioning groove 122 is arranged on the side of the secondary limiting ring 121 close to the reflector mounting seat 4. The projection of the secondary base 414 surface excluding the annular part of the primary base 413 on the surface of the secondary limiting ring 121 along the axis direction of the lens barrel 1 coincides with the position and shape of the positioning groove 122. The metal tube body 52 is located at the end of the quartz tube body 51 away from the connecting sleeve 12, and the metal tube body 52 is threadedly connected to the positioning ring plate 43.

[0043] Reference Figure 1, through the setting of the connecting sleeve 12, the user can quickly disassemble and separate the lens 31 mounting seat 3 and the reflector mounting seat 4, which is convenient for replacing the mirror body and reduces the difficulty of maintenance. The fixed section 11 and the connecting sleeve 12 are connected by a threaded connection, which can ensure that the two have a high concentricity after installation, thereby improving the accuracy of the laser module. The recessed area formed between the primary base 413, the secondary base 414 and the positioning ring plate 43 positions one end of the composite quartz tube 5, and the positioning groove 122 on the secondary limit ring 121 positions the other end of the composite quartz tube 5. The reflector mounting seat 4 and the composite quartz tube 5 are connected by threaded fastening, which on the one hand improves the concentricity between the reflector mounting seat 4 and the composite quartz tube 5 during installation, and on the other hand, the primary base 413 is clamped between the reflector mounting seat 4 and the composite quartz tube 5, which can effectively improve the structural stability of the free-form surface reflector 41 after installation.

[0044] Reference Figure 1 The free-form surface reflector 41 is made of metal material, which is an alloy material composed of aluminum, copper, steel, and nickel. The free-form surface reflector 41 made of metal material can greatly reduce the refraction effect produced when light is incident, thereby greatly reducing the energy loss that may exist in the reflection process of light, and metal material has less processing difficulty and higher processing accuracy.

[0045] Reference Figure 2 The bottom surface of the free-form surface reflector 41 is elliptical, the center of the bottom surface of the free-form surface reflector 41 is located on the axis of the lens barrel 1, the intersection of any plane passing through the axis of the lens barrel 1 and the free-form surface reflector 41 is an approximate triangle, and the two sides of any triangle are irregular curves, and a light divergence area 411 and a light convergence area 412 are provided on the reflective surface of the free-form surface reflector 41. The curved surface at the light divergence area 411 is convex outward, and the curved surface of the light convergence area 412 is concave inward. Two light divergence areas 411 are symmetrically arranged with the straight line where the short axis of the bottom surface of the free-form surface reflector 41 is located as the symmetry axis, and two light convergence areas 412 are symmetrically arranged with the straight line where the long axis of the bottom surface of the free-form surface reflector 41 is located as the symmetry axis, and each light divergence area 411 and light convergence area 412 are smoothly connected by a curved surface.

[0046] Reference Figure 3 The present invention also discloses a design and manufacturing method of a free-form surface reflector in a 360-degree reflective free-form surface shaping laser module, comprising the following steps:

[0047] S1: Determine the light intensity distribution formula of the elliptical spot according to the device parameters of the semiconductor laser itself;

[0048] S2: Using the law of reflection of light, establish the relationship between the incident light, the outgoing light and the free-form surface normal vector of the free-form surface reflector. Suppose the unit vector of the incident light is I, the unit vector of the outgoing light is O, the unit vector of the free-form surface normal vector at the reflection point is N, and the angle between O and N is θ, then I+2cosθN=O is satisfied, thereby realizing the redistribution of light energy;

[0049] S3: Using the law of conservation of energy, assuming that there is no energy loss in the process of light refraction through the lens and the free-form surface reflector, and that the absorption of light in the medium is negligible, the light intensity distribution formula of the 360° light ring formed on the regular cylindrical surface after the light is refracted can be obtained based on the light intensity distribution formula obtained in S1, and the light intensity at each point of the light ring is consistent;

[0050] S4: numerically solve the above mathematical model, transform the mathematical model into a set of equations containing several nonlinear equations by the method of differential substitution, and solve them by Newton iteration method. The number of iterations when solving by Newton iteration method is 3 to 5 times. After obtaining several data points, use three-dimensional mapping software to construct a free-form surface, import the free-form surface and the light intensity distribution formula in S1 into the lighting simulation software, the number of simulated light rays in the lighting simulation software is 3 million, and the reflected lighting spot is obtained on the target surface. The illuminance value is sampled point by point along the circumference of the spot, and the number of sampling points for point-by-point sampling is 200. The energy utilization rate and the average standard deviation of illuminance are used to quantitatively evaluate the simulated spot results. The evaluation targets are energy utilization rate ≥ 90% and illuminance evaluation standard deviation ≤ 0.1;

[0051] S5: Arrange the surface data that meets the conditions, and process and manufacture according to the surface size data. The processing method is to use a high-precision CNC machine tool and a single-point diamond tool for processing and forming.

[0052] In S4, the energy utilization rate is defined as the ratio of the energy incident on the target area to the energy incident on the free-form surface reflector, and the standard deviation of the illumination evaluation is determined by the following formula:

[0053] Average standard deviation of illuminance =

[0054]

[0055] Where M is the number of sampling points, E j and They respectively represent the illuminance value of the jth sampling point and the average illuminance of all sampling points. The following are the specific data measured in multiple tests.

[0056] Iterations Number of simulated rays / line Energy utilization Illuminance evaluation standard deviation 1 <![CDATA[3×10 6 ]]> 82.237％ 0.4205 2 <![CDATA[3×10 6 ]]> 86.547％ 0.2568 3 <![CDATA[3×10 6 ]]> 92.995％ 0.1031 4 <![CDATA[3×10 6 ]]> 94.297％ 0.0803 5 <![CDATA[3×10 6 ]]> 94.982％ 0.0772 6 <![CDATA[3×10 6 ]]> 95.325％ 0.0743

[0057] It can be seen that with the continuous increase in the number of iterations, the energy utilization rate gradually increases and stabilizes at about 95%, and the standard deviation of illumination evaluation gradually decreases and stabilizes at about 0.07, which basically meets the test requirements. In actual operation, due to the increase in the number of iterations, the time required for the computer to solve the surface will increase significantly. Therefore, in actual experiments, the number of iterations can be controlled at 3-5 times.

[0058] The implementation principle of this embodiment is as follows: the laser light emitted from the semiconductor laser 21 is directly irradiated on the surface of the free-form surface reflector 41 after being converged by the lens 31, and forms a light spot with an elliptical projection shape on the surface of the free-form surface reflector 41, and then, after being reflected by the free-form surface reflector 41, a horizontal laser light is projected within a range of 360° through the composite quartz tube 5. When the laser is emitted from the semiconductor laser 21, the energy of each point is evenly distributed, so on the elliptical light spot, the energy of each point in the area distributed along the long axis direction of the elliptical light spot is less than the energy of each point in the area distributed along the short axis direction of the elliptical light spot. Therefore, in order to make the elliptical light spot form a light with uniform energy distribution after being reflected by the free-form surface reflector 41, the basic idea is that the light in the area distributed along the long axis direction of the elliptical light spot needs to be converged after being irradiated on the free-form surface reflector 41 and reflected, so that the energy of the light in the area is increased; the light in the area distributed along the short axis direction of the elliptical light spot needs to be diverged after being irradiated on the free-form surface reflector 41 and reflected, so that the energy of the light in the area is weakened, thereby achieving the effect of laser energy redistribution after reflection. In this process, almost all the light in the laser is directly reflected by the free-form surface reflector 41 and passes through the composite quartz tube 5. Therefore, compared with the original method of using an aperture to shape the light spot, the energy utilization rate of the laser by this laser module is greatly improved, and through the setting of the light divergence area 411 and the light convergence area 412, the laser energy is evenly distributed after reflection, so that the line projection quality of the projection instrument is greatly improved.

[0059] See also Figure 3In actual operation, when the elliptical spot emitted by the laser is irradiated to the surface of the free-form surface reflector 41, the long axis length of the spot is about 3 mm, and due to the limitation of the processing method, the long axis length of the bottom surface of the free-form surface reflector 41 is about 12 mm. Therefore, when installing the laser module, it is necessary to place the long axis of the elliptical spot emitted by the semiconductor laser 21 orthogonally to the long axis of the bottom surface of the free-form surface reflector 41 to obtain a better reflection effect. And under this placement method, the area of ​​the elliptical spot along the long axis direction will be distributed in most of the areas where the light convergence area 412 is distributed along its generatrix direction, and the area of ​​the elliptical spot along the short axis direction will be distributed in a small part of the area where the light divergence area 411 is distributed along its generatrix direction. The width of the light band formed by the area of ​​the elliptical spot along the long axis direction will decrease after passing through the light convergence area 412, and the width of the light band formed by the area of ​​the elliptical spot along the short axis direction will increase after passing through the light divergence area 411, thereby further improving the uniformity of the distribution after laser reflection.

[0060] The embodiments of this specific implementation method are all preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Therefore, any equivalent changes made based on the structure, shape, and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A 360-degree reflective free-form surface shaping laser module, comprising a lens barrel (1), a laser light source base (2) being arranged at one end of the lens barrel (1), a semiconductor laser (21) being arranged at the laser light source base (2), light generated by the semiconductor laser (21) being incident into the lens barrel (1) and the axis of the light coincides with the axis of the lens barrel (1), a lens (31) mounting seat (3) being arranged in the middle of the lens barrel (1), a lens (31) being arranged at the lens (31) mounting seat (3), and characterized in that: A free-form surface reflector (41) and a reflector mounting seat (4) for positioning and mounting the free-form surface reflector (41) are arranged at one end of the lens barrel (1) away from the laser light source base (2); a composite quartz tube (5) is arranged on the side of the lens barrel (1) close to the reflector mounting seat (4); the bottom surface of the free-form surface reflector (41) is elliptical in shape; the center of the bottom surface of the free-form surface reflector (41) is located on the axis of the lens barrel (1); the contour of the intersection of any plane passing through the axis of the lens barrel (1) and the free-form surface reflector (41) is an approximate triangle, and the two sides of any triangle are irregular curves; and a light divergence area (411) and a light convergence area (412) are arranged on the reflection surface of the free-form surface reflector (41).

2. A 360-degree reflective free-form surface shaping laser module according to claim 1, characterized in that: The curved surface at the light diverging area (411) is in an outwardly convex shape, and the curved surface at the light converging area (412) is in an inwardly concave shape. Two light diverging areas (411) are symmetrically arranged with the straight line where the short axis of the bottom surface of the free-form surface reflector (41) is located as the symmetry axis. Two light converging areas (412) are symmetrically arranged with the straight line where the long axis of the bottom surface of the free-form surface reflector (41) is located as the symmetry axis. Each light diverging area (411) and each light converging area (412) are smoothly connected by a curved surface.

3. A 360-degree reflective free-form surface shaping laser module according to claim 2, characterized in that: The free-form surface reflector (41) is made of a metal material, which is an alloy material consisting of aluminum, copper, steel and nickel.

4. A 360-degree reflective free-form surface shaping laser module according to claim 3, characterized in that: The lens barrel (1) comprises a fixed section (11) and a connecting sleeve (12); the lens (31) mounting seat (3) is located in the fixed section (11); the reflector mounting seat (4) is located at the end of the connecting sleeve (12) away from the laser light source base (2); a primary limiting ring (111) is formed at the end of the fixed section (11) away from the laser light source base (2); an internal thread is formed on the inner side wall of the fixed section (11) away from the laser light source base (2); a secondary limiting ring (121) and an external thread matched with the internal thread are formed on the outer side wall of the connecting sleeve (12); the external thread covers a portion of the outer side wall of the connecting sleeve (12) from the end close to the laser light source base (2) to the secondary limiting ring (121).

5. A 360-degree reflective free-form surface shaping laser module according to claim 4, characterized in that: A primary base (413) and a secondary base (414) are stacked in sequence on the bottom surface of the free-form surface reflector (41); the primary base (413) and the secondary base (414) are both circular and concentrically arranged; the reflector mounting seat (4) comprises a circular base plate (42) and a positioning ring plate (43) located at the edge of the base plate (42) and arranged perpendicularly to the base plate (42); the positioning ring plate (43) is threadedly fastened to the composite quartz tube (5); a circular positioning groove (122) is arranged on a surface of the secondary limiting ring (121) close to the reflector mounting seat (4); the projection of the surface of the secondary base (414) excluding the annular portion of the primary base (413) on the surface of the secondary limiting ring (121) along the axis direction of the lens barrel (1) coincides with the position and shape of the positioning groove (122).

6. The 360-degree reflective free-form surface shaping laser module according to claim 5, characterized in that: The composite quartz tube (5) comprises a quartz tube body (51) and a metal tube body (52) whose ends are bonded to each other. The metal tube body (52) is located at one end of the quartz tube body (51) away from the connecting sleeve (12). The metal tube body (52) is threadedly fastened to the positioning ring plate (43).

7. A design and manufacturing method for a free-form surface reflector in a 360-degree reflective free-form surface shaping laser module, characterized in that: The following steps are included: S1: Determine the light intensity distribution formula of the elliptical spot according to the device parameters of the semiconductor laser itself; S2: Using the law of reflection of light, establish the relationship between the incident light, the outgoing light and the free-form surface normal vector of the free-form surface reflector. Suppose the unit vector of the incident light is I, the unit vector of the outgoing light is O, the unit vector of the free-form surface normal vector at the reflection point is N, and the angle between O and N is θ, then I+ 2 cosθN = O is satisfied, thereby realizing the redistribution of light energy; S3: Using the law of conservation of energy, assuming that there is no energy loss in the process of light refraction through the lens and the free-form surface reflector, and that the absorption of light in the medium is negligible, the intensity distribution formula of the 360° light ring formed on the regular cylindrical surface after the light is refracted is obtained according to the light intensity distribution formula obtained in S1, and the light intensity at each point of the light ring is made consistent; S4: numerically solve the light intensity distribution formula of the elliptical light spot in S1, I+ 2 cosθN = O in S2, and the light intensity distribution formula of the 360° light ring formed in S3. The three formulas are converted into a set of nonlinear equations by differential substitution method, and solved by Newton iteration method. After obtaining several data points, a free-form surface is constructed by three-dimensional mapping software. The free-form surface and the light intensity distribution formula in S1 are imported into the lighting simulation software. The reflected lighting spot is obtained on the target surface, and the illuminance value is sampled point by point along the circumference of the spot. The simulated spot results are quantitatively evaluated by practical energy utilization rate and average standard deviation of illuminance. The evaluation targets are energy utilization rate ≥ 90% and illuminance evaluation standard deviation ≤ 0.

1. S5: Arrange the surface data that meets the conditions, and process and manufacture according to the surface size data. The processing method is to use a high-precision CNC machine tool and a single-point diamond tool for processing and forming.

8. The method for designing and manufacturing a free-form surface reflector in a 360-degree reflective free-form surface shaping laser module according to claim 7, characterized in that: In step S4, the number of iterations when solving using the Newton iteration method is 3 to 5 times, and the number of simulated light rays in the lighting simulation software is 3 million.

9. The design and manufacturing method of a free-form surface reflector in a 360-degree reflective free-form surface shaping laser module according to claim 7, characterized in that: In step S4, the number of sampling points for point-by-point sampling is 200.

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