A processing head for focusing objective lens and dual-band micro-jet laser equipment

Abstract

The invention discloses a focusing objective lens and a processing head of a dual-band micro-jet laser device, belonging to the field of micro-jet laser devices. The focusing objective lens is applied to the processing head of the dual-band micro-jet laser device, the processing head comprises a water cavity and a nozzle, the nozzle comprises a nozzle hole, the focusing objective lens, the water cavity and the nozzle are arranged in sequence along the optical axis direction of the focusing objective lens, the focusing objective lens is used to focus a dual-band light beam into the water cavity and the nozzle hole, the focusing objective lens comprises a biconcave negative lens group, a biconvex positive lens group and a meniscus positive lens group which are coaxially arranged in sequence; the dual-band light beam enters the biconvex positive lens group after being diverged by the biconcave negative lens group, enters the meniscus positive lens group after being converged by the biconvex positive lens group, passes through the water cavity and enters the nozzle hole after being converged by the meniscus positive lens group, thereby improving the processing quality and processing efficiency of laser processing.

Description

Technical Field

[0001] The invention belongs to the technical field of micro jet laser equipment, and in particular relates to a focusing objective lens and a processing head of a dual-band micro jet laser equipment. Background Art

[0002] Microjet laser processing technology is a precision processing technology that uses a water jet to guide a laser beam to cut and punch the workpiece to be processed. Microjet laser equipment is a laser processing equipment based on microjet laser processing technology. Dual-band microjet laser equipment is a microjet laser equipment that can simultaneously emit two different wavelengths of laser. Usually, a microjet laser equipment includes a mounting frame, a processing head, and a fixture. The processing head is mounted on the mounting frame for fixing. The fixture is used to clamp the workpiece. The dual-band microjet laser is emitted from the processing head to perform laser processing on the workpiece on the fixture.

[0003] The processing head of a common dual-band micro-jet laser device includes a first laser emitter, a second laser emitter, a beam combiner, a focusing mirror, and a coupling water cavity. The first laser emitter is used to emit a first light beam, the second laser emitter is used to emit a second light beam, the beam combiner is used to combine the first light beam and the second light beam into a dual-band light beam, the focusing mirror is used to converge the dual-band light beam, the coupling water cavity is used to provide a high-pressure water flow, and the focusing mirror is a convex lens. With this structure, the dual-band light beam can be converged into the coupling water cavity through the convex lens, and then mixed with the high-pressure water flow in the coupling water cavity to form a water jet and impact the surface of the workpiece, so that the laser beam in the water jet can penetrate the workpiece for processing under the guidance of the high-pressure water beam. However, since the surface of the convex lens is a spherical surface, when the dual-band light beam passes through the convex lens, the focusing ability of the central area of ​​the lens and the edge area of ​​the lens are different, resulting in the entire light beam of the first light beam, the entire light beam of the second light beam, and the first light beam and the second light beam cannot be converged at the same point to form a spherical aberration phenomenon. When the focusing mirror has spherical aberration, the energy concentration effect of the dual-band light beam is poor, resulting in poor processing quality and low processing efficiency of laser processing. Summary of the invention

[0004] In order to solve the above problems existing in the prior art, the present invention provides a focusing objective lens and a processing head of a dual-band micro jet laser device. The technical problem to be solved by the present invention is achieved through the following technical solutions:

[0005] In the first aspect, the present invention provides a focusing objective lens, which is applied to a processing head of a dual-band micro-jet laser device. The processing head includes a water chamber and a nozzle, and the nozzle includes a nozzle. The focusing objective lens, the water chamber and the nozzle are arranged in sequence along the optical axis direction of the focusing objective lens. The focusing objective lens is used to focus the dual-band light beam into the water chamber and the nozzle. The focusing objective lens includes a double concave negative lens group, a double convex positive lens group and a meniscus positive lens group which are coaxially arranged in sequence; the dual-band light beam diverges through the double concave negative lens group and enters the double convex positive lens group, converges through the double convex positive lens group and enters the meniscus positive lens group, and converges through the meniscus positive lens group and passes through the water chamber and enters the nozzle.

[0006] In one embodiment of the present invention, a biconvex positive lens group includes a first biconvex positive lens and a second biconvex positive lens; a biconcave negative lens group, a first biconvex positive lens, a second biconvex positive lens and a meniscus positive lens group are arranged in sequence, and the dual-band light beam enters the first biconvex positive lens after being diverged by the biconcave negative lens group, enters the second biconvex positive lens after being converged by the first biconvex positive lens, and enters the meniscus positive lens group after being converged by the second biconvex positive lens.

[0007] In one embodiment of the present invention, the absolute value of the radius of curvature of the upper surface of the first biconvex positive lens is greater than the absolute value of the radius of curvature of the lower surface of the first biconvex positive lens, the absolute value of the radius of curvature of the upper surface of the second biconvex positive lens is smaller than the absolute value of the radius of curvature of the lower surface of the second biconvex positive lens, and the absolute value of the radius of curvature of the lower surface of the first biconvex positive lens is greater than the absolute value of the radius of curvature of the upper surface of the second biconvex positive lens.

[0008] In one embodiment of the present invention, the meniscus positive lens group includes a first meniscus positive lens and a second meniscus positive lens; the double concave negative lens group, the first double convex positive lens, the second double convex positive lens, the first meniscus positive lens and the second meniscus positive lens are arranged in sequence, the dual-band light beam converges through the second double convex positive lens and enters the first meniscus positive lens, converges through the first meniscus positive lens and enters the second meniscus positive lens, and converges through the second meniscus positive lens and passes through the water cavity and enters the spray hole.

[0009] In one embodiment of the present invention, the radius of curvature of the upper surface of the first meniscus positive lens is smaller than the radius of curvature of the lower surface of the first meniscus positive lens, the radius of curvature of the upper surface of the second meniscus positive lens is smaller than the radius of curvature of the lower surface of the second meniscus positive lens, and the radius of curvature of the upper surface of the first meniscus positive lens is greater than the radius of curvature of the lower surface of the second meniscus positive lens.

[0010] In one embodiment of the present invention, the biconcave negative lens group includes a biconcave negative lens, the absolute value of the radius of curvature of the upper surface of the biconcave negative lens is greater than the absolute value of the radius of curvature of the lower surface of the biconcave negative lens; the refractive index of the biconcave negative lens is greater than the refractive index of the first biconvex positive lens, the refractive index of the first biconvex positive lens is greater than the refractive index of the second biconvex positive lens, the refractive index of the first meniscus positive lens is greater than the refractive index of the first biconvex positive lens, and the refractive index of the second meniscus positive lens is less than the refractive index of the first meniscus positive lens.

[0011] In one embodiment of the present invention, the dual-band light beam includes a first light beam and a second light beam, the first light beam is green light, and the second light beam is blue light;

[0012] The curvature radius of the upper surface of the double concave negative lens is -260mm~-250mm, the curvature radius of the lower surface is 75mm~85mm, the refractive index is 1.92~1.96, and the Abbe number is 17.5~18.5;

[0013] The first biconvex positive lens has an upper surface with a radius of curvature of 285 mm to 295 mm, a lower surface with a radius of curvature of -115 mm to -110 mm, a refractive index of 1.70 to 1.73, and an Abbe number of 53.5 to 54.1;

[0014] The second biconvex positive lens has an upper surface with a curvature radius of 55 mm to 65 mm, a lower surface with a curvature radius of -150 mm to -140 mm, a refractive index of 1.67 to 1.70, and an Abbe number of 54.1 to 54.9;

[0015] The first meniscus positive lens has an upper surface curvature radius of 27 mm to 33 mm, a lower surface curvature radius of 53 mm to 59 mm, a refractive index of 1.72 to 1.75, and an Abbe number of 54.3 to 54.9;

[0016] The curvature radius of the upper surface of the second meniscus positive lens is 13 mm to 17 mm, the curvature radius of the lower surface is 18 mm to 21 mm, the refractive index is 1.44 to 1.48, and the Abbe number is 67.5 to 68.2.

[0017] In one embodiment of the present invention, the dual-band light beam includes a first light beam and a second light beam, the first light beam is green light, and the second light beam is near-infrared light;

[0018] The curvature radius of the upper surface of the double concave negative lens is -90mm~-85mm, the curvature radius of the lower surface is 70mm~80mm, the refractive index is 1.94~1.98, and the Abbe number is 17.3~17.6;

[0019] The first biconvex positive lens has an upper surface with a curvature radius of 75 mm to 85 mm, a lower surface with a curvature radius of -66 mm to -56 mm, a refractive index of 1.70 to 1.73, and an Abbe number of 53.5 to 54.1;

[0020] The second biconvex positive lens has an upper surface with a radius of curvature of 51 mm to 60 mm, a lower surface that is flat, a refractive index of 1.67 to 1.70, and an Abbe number of 54.1 to 54.9;

[0021] The first meniscus positive lens has an upper surface curvature radius of 26 mm to 32 mm, a lower surface curvature radius of 45 mm to 51 mm, a refractive index of 1.72 to 1.75, and an Abbe number of 54.3 to 54.9;

[0022] The curvature radius of the upper surface of the second meniscus positive lens is 13 mm to 17 mm, the curvature radius of the lower surface is 18 mm to 20 mm, the refractive index is 1.44 to 1.48, and the Abbe number is 67.5 to 68.2.

[0023] In one embodiment of the present invention, the focusing objective lens also includes a lens barrel, and a first pressure ring, a second pressure ring, a first spacer ring, a second spacer ring and a third spacer ring are provided in the lens barrel, and a first boss and a second boss are provided on the side wall of the lens barrel; the second boss is used to support the second meniscus positive lens, and the first pressure ring cooperates with the inner wall thread of the lens barrel to press the second meniscus positive lens onto the first boss; the first boss is used to support the first meniscus positive lens, the first spacer ring is arranged between the second biconvex positive lens and the first meniscus positive lens, the second spacer ring is arranged between the first biconvex positive lens and the second biconvex positive lens, the third spacer ring is arranged between the biconcave negative lens and the first biconvex positive lens, the second pressure ring and the third spacer ring are respectively located on both sides of the biconcave negative lens, and the second pressure ring cooperates with the inner wall thread of the lens barrel to press the first meniscus positive lens onto the first boss.

[0024] In the second aspect, the present invention provides a processing head for a dual-band micro-jet laser device, comprising a window, a water chamber, a nozzle and a focusing objective lens as provided in the above scheme, the nozzle comprising a nozzle, the focusing objective lens, the window, the water chamber and the nozzle are arranged in sequence along the optical axis direction of the focusing objective lens, and the focusing objective lens is used to focus the dual-band light beam.

[0025] In a third aspect, the present invention provides a dual-band micro-jet laser device, including a processing head of the dual-band micro-jet laser device provided by the above scheme.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] In the above scheme provided by the present invention, the focusing objective lens is applied to the processing head of the dual-band micro-jet laser device, the processing head includes a water cavity and a nozzle, the nozzle includes a nozzle hole, the focusing objective lens, the water cavity and the nozzle are arranged in sequence along the optical axis direction of the focusing objective lens, the focusing objective lens is used to focus the dual-band light beam into the water cavity and the nozzle hole, the focusing objective lens includes a double concave negative lens group, a double convex positive lens group and a meniscus positive lens group which are coaxially arranged in sequence; the dual-band light beam enters the double convex positive lens group after being diverged by the double concave negative lens group, enters the meniscus positive lens group after being converged by the double convex positive lens group, and passes through the water cavity after being converged by the meniscus positive lens group to enter the nozzle hole. With this structure, when the double concave negative lens group and the double convex positive lens group are used in combination, the refraction effect of light in different areas can be balanced. The negative spherical aberration provided by the double concave negative lens group and the positive spherical aberration provided by the double convex positive lens offset each other, which can reduce the overall spherical aberration of the focusing objective lens, improve the focusing effect of the overall beam of the first light beam in the dual-band light beam, improve the focusing effect of the overall beam of the second light beam in the dual-band light beam, and improve the overlap between the focusing spot of the first light beam and the focusing spot of the second light beam, so that the overall focusing effect of the dual-band light beam is better, thereby improving the processing quality and processing efficiency of laser processing. Secondly, the spherical aberration can be minimized by the meniscus positive lens group, thereby further reducing the size of the convergent spot of the dual-band light beam, improving the focusing effect of the dual-band light beam, and making the processing quality and processing efficiency of laser processing higher. In addition, by guiding the refraction effect of the light beam through the cooperation of the double concave negative lens group, the double convex positive lens group and the meniscus positive lens group, chromatic aberration can be eliminated, which can further improve the focusing effect of the dual-band light beam and improve the processing quality and processing efficiency of laser processing.

[0028] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a cross-sectional view of a focusing objective lens provided in Embodiment 1 of the present invention;

[0030] Figure 2 is a schematic diagram of each lens in the focusing objective lens provided in the first embodiment of the present invention;

[0031] Figure 3 is a point diagram of the focusing objective lens provided in the first embodiment of the present invention;

[0032] Figure 4 is a light fan diagram of the focusing objective lens provided in the first embodiment of the present invention;

[0033] Figure 5 is a focal shift diagram of the focusing objective lens provided in the first embodiment of the present invention;

[0034] Figure 6 is a cross-sectional view of a focusing objective lens provided in Embodiment 2 of the present invention;

[0035] Figure 7 is a schematic diagram of each lens in the focusing objective lens provided in the second embodiment of the present invention;

[0036] Figure 8 is a point diagram of the focusing objective lens provided in the second embodiment of the present invention;

[0037] Fig. 9 is a light fan diagram of the focusing objective lens provided in the second embodiment of the present invention;

[0038] Fig.10 It is a focal shift diagram of the focusing objective lens provided in the second embodiment of the present invention.

[0039] Figure markings: 1-focusing objective lens, 2-double concave negative lens, 3-first double convex positive lens, 4-second double convex positive lens, 5-first meniscus positive lens, 6-second meniscus positive lens, 7-lens barrel, 8-first pressure ring, 9-second pressure ring, 10-first spacer ring, 11-second spacer ring, 12-third spacer ring, 13-first boss, 14-second boss, 15-window, 16-water chamber, 17-nozzle. DETAILED DESCRIPTION

[0040] The present invention is further described in detail below with reference to specific embodiments, but the embodiments of the present invention are not limited thereto.

[0041] Embodiment 1:

[0042] See also Figure 1 and Figure 2 The embodiment of the present invention provides a focusing objective lens, which is applied to a processing head of a dual-band micro-jet laser device. The processing head includes a water cavity 16 and a nozzle 17. The nozzle 17 includes a nozzle hole. The focusing objective lens 1, the water cavity 16 and the nozzle 17 are arranged in sequence along the optical axis direction of the focusing objective lens 1. The focusing objective lens 1 is used to focus the dual-band light beam into the water cavity 16 and the nozzle hole. The focusing objective lens 1 includes a biconcave negative lens group, a biconvex positive lens group and a meniscus positive lens group which are coaxially arranged in sequence. The dual-band light beam diverges through the biconcave negative lens group and enters the biconvex positive lens group. After being converged by the biconvex positive lens group, the dual-band light beam enters the meniscus positive lens group. After being converged by the meniscus positive lens group, the dual-band light beam passes through the water cavity 16 and enters the nozzle hole.

[0043] In some embodiments of the present invention, the double concave negative lens group includes one or more double concave negative lenses 2. The double concave negative lens 2 is a lens structure with two concave surfaces. The double concave negative lens 2 diverges the light beam and generates negative spherical aberration and positive axial chromatic aberration. The "multiple" in the embodiments of the present invention refers to two or more. Among them, spherical aberration and axial chromatic aberration are both common aberration phenomena in optical systems. Spherical aberration includes positive spherical aberration and negative spherical aberration, and axial chromatic aberration includes positive axial chromatic aberration and negative axial chromatic aberration.

[0044] In some embodiments of the present invention, the biconvex positive lens group includes one or more biconvex positive lenses. The biconvex positive lens is a lens structure with two concave surfaces. The biconvex positive lens converges the light beam and produces positive spherical aberration and negative axial chromatic aberration.

[0045] In some embodiments of the present invention, the meniscus positive lens group includes one or more meniscus positive lenses. The meniscus positive lens is a lens structure composed of two curved surfaces with similar curvature radii and has a meniscus shape. The meniscus positive lens has a converging effect on the light beam and produces positive spherical aberration and negative axial chromatic aberration.

[0046] In some embodiments of the present invention, the biconcave negative lens group, the biconvex positive lens group and the meniscus positive lens group are coaxially arranged in sequence, which means that the biconcave negative lens group, the biconvex positive lens group and the meniscus positive lens group are arranged in sequence along the optical axis direction of the biconcave negative lens group.

[0047] In some embodiments of the present invention, the optical axis direction of the focusing objective lens 1 coincides with the axial direction of the nozzle, so that the focusing spot of the focusing objective lens 1 can be located at the position of the nozzle, so that the dual-band light beam can be directly ejected from the nozzle after being focused by the focusing objective lens 1, thereby improving the processing quality of laser processing.

[0048] In some embodiments of the present invention, when the biconcave negative lens group, the biconvex positive lens group and the meniscus positive lens group are arranged in sequence, the meniscus positive lens group is located between the biconvex positive lens group and the water cavity 16 .

[0049] In some embodiments of the present invention, the processing head of the dual-band micro-jet laser device further includes a first laser emitter, a second laser emitter, a first reflector, and a second reflector. The first laser emitter can emit a first light beam, and the second laser emitter can emit a second light beam. The wavelengths of the first light beam and the second light beam are different. The first reflector is disposed between the first laser emitter and the focusing objective lens 1 to reflect the first light beam onto the focusing objective lens 1. The second reflector is disposed between the second laser emitter and the focusing objective lens 1 to reflect the second light beam onto the focusing objective lens 1. The first light beam and the second light beam can form a dual-band light beam. In addition, the processing head may further include a beam combiner, which is used to combine the first light beam and the second light beam into a dual-band light beam, and the focusing objective lens 1 is used to focus the dual-band light beam.

[0050] In the above scheme provided by the present invention, the focusing objective lens 1 is applied to the processing head of the dual-band microjet laser device, the processing head includes a water cavity 16 and a nozzle 17, the nozzle 17 includes a nozzle, the focusing objective lens 1, the water cavity 16 and the nozzle 17 are arranged in sequence along the optical axis direction of the focusing objective lens 1, the focusing objective lens 1 is used to focus the dual-band light beam into the water cavity 16 and the nozzle, the focusing objective lens 1 includes a double concave negative lens group, a double convex positive lens group and a meniscus positive lens group which are arranged coaxially in sequence; the dual-band light beam diverges through the double concave negative lens group and enters the double convex positive lens group, converges through the double convex positive lens group and enters the meniscus positive lens group, and converges through the meniscus positive lens group and passes through the water cavity 16 and enters the nozzle. With this structure, when the double concave negative lens group and the double convex positive lens group are used in combination, the refraction effect of light in different areas can be balanced. The negative spherical aberration provided by the double concave negative lens group and the positive spherical aberration provided by the double convex positive lens offset each other, which can reduce the overall spherical aberration of the focusing objective 1, improve the focusing effect of the overall beam of the first light beam in the dual-band light beam, improve the focusing effect of the overall beam of the second light beam in the dual-band light beam, and improve the overlap between the focusing spot of the first light beam and the focusing spot of the second light beam, so that the overall focusing effect of the dual-band light beam is better, thereby improving the processing quality and processing efficiency of laser processing. Secondly, the spherical aberration can be minimized by the meniscus positive lens group, thereby further reducing the size of the convergence spot of the dual-band light beam, improving the focusing effect of the dual-band light beam, and making the processing quality and processing efficiency of laser processing higher. In addition, the refraction effect of the light beam guided by the cooperation of the double concave negative lens group, the double convex positive lens group and the meniscus positive lens group can eliminate chromatic aberration, further improve the focusing effect of the dual-band light beam, and improve the processing quality and processing efficiency of laser processing.

[0051] In some embodiments of the present invention, the biconvex positive lens group includes a first biconvex positive lens 3 and a second biconvex positive lens 4; the biconcave negative lens group, the first biconvex positive lens 3, the second biconvex positive lens 4 and the meniscus positive lens group are arranged in sequence, and the dual-band light beam enters the first biconvex positive lens 3 after being diverged by the biconcave negative lens group, enters the second biconvex positive lens 4 after being converged by the first biconvex positive lens 3, and enters the meniscus positive lens group after being converged by the second biconvex positive lens 4. With this structure, the optical path of the dual-band light beam can be fully optimized through two biconvex positive lenses, the convergence effect of the dual-band light beam can be improved, the spherical aberration and chromatic aberration of the focusing objective lens 1 can be further corrected, and the processing quality and efficiency of laser processing can be improved.

[0052] In some embodiments of the present invention, the optical axis of the first biconvex positive lens 3 and the optical axis of the second biconvex positive lens 4 are located on the same straight line. In this way, the optical path of the dual-band light beam can be further optimized and the convergence effect of the dual-band light beam can be improved. Among them, the first biconvex positive lens 3 can converge the light beam and produce positive spherical aberration and negative axial chromatic aberration, and the second biconvex positive lens 4 can converge the light beam and produce positive spherical aberration and negative axial chromatic aberration.

[0053] In some embodiments of the present invention, the absolute value of the radius of curvature of the upper surface of the first biconvex positive lens 3 is greater than the absolute value of the radius of curvature of the lower surface of the first biconvex positive lens 3, the absolute value of the radius of curvature of the upper surface of the second biconvex positive lens 4 is smaller than the absolute value of the radius of curvature of the lower surface of the second biconvex positive lens 4, and the absolute value of the radius of curvature of the lower surface of the first biconvex positive lens 3 is greater than the absolute value of the radius of curvature of the upper surface of the second biconvex positive lens 4. With this structure, when the absolute value of the radius of curvature of the upper surface of the first biconvex positive lens 3 is greater than the absolute value of the radius of curvature of the lower surface of the first biconvex positive lens 3, the first biconvex positive lens 3 is an aspheric lens. The use of the aspheric lens can further correct the spherical aberration and chromatic aberration of the focusing objective 1, thereby improving the processing quality and efficiency of laser processing; and the lower surface of the first biconvex positive lens 3 has a stronger converging effect on the light beam than the upper surface. Therefore, when the light beam diverged by the biconcave negative lens group enters the first biconvex positive lens 3, it can first pass through the upper surface of the first biconvex positive lens 3 for the first convergence, and then pass through the lower surface of the first biconvex positive lens 3 for the second convergence, thereby improving the converging effect of the light beam passing through the first biconvex positive lens 3, and then improving the focusing effect of the dual-band light beam when passing through the focusing objective 1, thereby improving the processing quality and efficiency of laser processing. When the absolute value of the radius of curvature of the upper surface of the second biconvex positive lens 4 is less than the absolute value of the radius of curvature of the lower surface of the second biconvex positive lens 4, the second biconvex positive lens 4 is an aspheric lens, and the use of an aspheric lens can further correct the spherical aberration and chromatic aberration of the focusing objective lens 1, thereby improving the processing quality and processing efficiency of laser processing; and the thickness of the second biconvex positive lens 4 can be reduced, thereby improving the convenience of installation and processing of the second biconvex positive lens 4. When the absolute value of the radius of curvature of the lower surface of the first biconvex positive lens 3 is greater than the absolute value of the radius of curvature of the upper surface of the second biconvex positive lens 4, the upper surface of the second biconvex positive lens 4 has a stronger convergence effect on the light beam than the lower surface of the first biconvex positive lens 3, and the light beam converged by the first biconvex positive lens 3 can be further converged by the upper surface of the second biconvex positive lens 4, thereby improving the focusing effect of the dual-band light beam when passing through the focusing objective lens 1, thereby improving the processing quality and processing efficiency of laser processing.

[0054] In some embodiments of the present invention, the meniscus positive lens group includes a first meniscus positive lens 5 and a second meniscus positive lens 6; the biconcave negative lens group, the first biconvex positive lens 3, the second biconvex positive lens 4, the first meniscus positive lens 5 and the second meniscus positive lens 6 are arranged in sequence, and the dual-band light beam enters the first meniscus positive lens 5 after being converged by the second biconvex positive lens 4, enters the second meniscus positive lens 6 after being converged by the first meniscus positive lens 5, and passes through the water cavity 16 to enter the spray hole after being converged by the second meniscus positive lens 6. With this structure, the spherical aberration is further corrected by the cooperation of the first meniscus positive lens 5 and the second meniscus positive lens 6, so that the size of the converged light spot of the dual-band light beam can be fully reduced, the focusing effect of the dual-band light beam can be improved, and the processing quality and efficiency of laser processing can be further improved.

[0055] In some embodiments of the present invention, the first meniscus positive lens 5 can converge the light beam and produce positive spherical aberration and negative axial chromatic aberration; the second meniscus positive lens 6 can converge the light beam and produce positive spherical aberration and negative axial chromatic aberration.

[0056] In some embodiments of the present invention, the radius of curvature of the upper surface of the first meniscus positive lens 5 is smaller than the radius of curvature of the lower surface of the first meniscus positive lens 5, the radius of curvature of the upper surface of the second meniscus positive lens 6 is smaller than the radius of curvature of the lower surface of the second meniscus positive lens 6, and the radius of curvature of the upper surface of the first meniscus positive lens 5 is larger than the radius of curvature of the lower surface of the second meniscus positive lens 6. With this structure, the optical path of the light beam can be further optimized through the first meniscus positive lens 5 and the second meniscus positive lens 6, so that the dual-band light beam can be converged into the nozzle of the nozzle 17, the focusing effect of the focusing objective lens 1 on the dual-band light beam is improved, and the processing quality and efficiency of laser processing are further improved.

[0057] In some embodiments of the present invention, the biconcave negative lens group includes a biconcave negative lens 2, the absolute value of the radius of curvature of the upper surface of the biconcave negative lens 2 is greater than the absolute value of the radius of curvature of the lower surface of the biconcave negative lens 2; the refractive index of the biconcave negative lens 2 is greater than the refractive index of the first biconvex positive lens 3, the refractive index of the first biconvex positive lens 3 is greater than the refractive index of the second biconvex positive lens 4, the refractive index of the first meniscus positive lens 5 is greater than the refractive index of the first biconvex positive lens 3, and the refractive index of the second meniscus positive lens 6 is less than the refractive index of the first meniscus positive lens 5. With this structure, when the absolute value of the radius of curvature of the upper surface of the double concave negative lens 2 is greater than the absolute value of the radius of curvature of the lower surface of the double concave negative lens 2, the double concave negative lens 2 can be an aspheric lens. The use of the aspheric lens can further correct the spherical aberration and chromatic aberration of the focusing objective 1, thereby improving the processing quality and efficiency of laser processing; and the divergent effect of the lower surface of the double concave negative lens 2 on the light beam is stronger than the divergent effect of the upper surface on the light beam. Therefore, when the dual-band light beam enters the double concave negative lens 2, it can first pass through the upper surface of the double concave negative lens 2 for the first divergence, and then pass through the lower surface of the double concave negative lens 2 for the second divergence, thereby improving the divergence effect of the light beam passing through the double concave negative lens 2, thereby improving the focusing effect of the dual-band light beam when passing through the focusing objective 1, thereby improving the processing quality and efficiency of laser processing. In addition, by adjusting the refractive indices of the biconcave negative lens 2, the first biconvex positive lens 3, the second biconvex positive lens 4, the first meniscus positive lens 5 and the second meniscus positive lens 6, chromatic aberration can be further corrected to improve the processing quality and efficiency of laser processing.

[0058] In some embodiments of the present invention, the processing head further includes a window 15, which is located between the focusing lens 1 and the water cavity 16 to separate the focusing lens 1 from the water cavity 16. The window 15 may be a flat glass, and the window 15 may generate positive spherical aberration and negative axial chromatic aberration. By canceling the spherical aberration or chromatic aberration between the window 15 and the focusing lens 1, the processing quality and processing efficiency of the laser processing may be further improved.

[0059] In some embodiments of the present invention, the focusing objective 1 also includes a lens barrel 7, in which a first pressure ring 8, a second pressure ring 9, a first spacer ring 10, a second spacer ring 11 and a third spacer ring 12 are provided, and a first boss 13 and a second boss 14 are provided on the side wall of the lens barrel 7; the second boss 14 is used to support the second meniscus positive lens 6, and the first pressure ring 8 and the inner wall thread of the lens barrel 7 are matched to press the second meniscus positive lens 6 onto the first boss 13; the first boss 13 is used to support the first meniscus positive lens 5, the first spacer ring 10 is arranged between the second biconvex positive lens 4 and the first meniscus positive lens 5, the second spacer ring 11 is arranged between the first biconvex positive lens 3 and the second biconvex positive lens 4, the third spacer ring 12 is arranged between the biconcave negative lens 2 and the first biconvex positive lens 3, the second pressure ring 9 and the third spacer ring 12 are respectively located on both sides of the biconcave negative lens 2, and the second pressure ring 9 and the inner wall thread of the lens barrel 7 are matched to press the first meniscus positive lens 5 onto the first boss 13. By adopting this structure, through the cooperation of the first pressure ring 8, the second pressure ring 9, the first spacer ring 10, the second spacer ring 11, the third spacer ring 12, the first boss 13 and the second boss 14, the double concave negative lens 2, the first double convex positive lens 3, the second double convex positive lens 4, the first meniscus positive lens 5 and the second meniscus positive lens 6 can be stably installed in the lens barrel 7, thereby improving the convenience of installing the focusing objective lens 1.

[0060] In some embodiments of the present invention, the first pressing ring 8 is a metal ring with external threads, the inner wall of the lens barrel 7 is provided with internal threads that match the external threads of the first pressing ring 8, the second pressing ring 9 is a metal ring with external threads, the inner wall of the lens barrel 7 is provided with internal threads that match the external threads of the second pressing ring 9. The first spacer 10, the second spacer 11 and the third spacer 12 are all metal rings without threads, and the distance between the second boss 14 and the axis of the lens barrel 7 is smaller than the distance between the first boss 13 and the axis of the lens barrel 7.

[0061] In some embodiments of the present invention, the dual-band light beam includes a first light beam and a second light beam, the first light beam is green light, the second light beam is blue light, the radius of curvature of the upper surface of the double concave negative lens 2 is -260mm~-250mm, the radius of curvature of the lower surface is 75mm~85mm, the refractive index is 1.92~1.96, preferably 1.94595, and the Abbe number is 17.5~18.5, preferably 17.94196. The radius of curvature of the upper surface of the first double convex positive lens 3 is 285mm~295mm, the radius of curvature of the lower surface is -115mm~-110mm, the refractive index is 1.70~1.73, preferably 1.713, and the Abbe number is 53.5~54.1, preferably 53.83297. The second biconvex positive lens 4 has a curvature radius of 55 mm to 65 mm on the upper surface, a curvature radius of -150 mm to -140 mm on the lower surface, a refractive index of 1.67 to 1.70, preferably 1.69211, and an Abbe number of 54.1 to 54.9, preferably 54.5392. The first meniscus positive lens 5 has a curvature radius of 27 mm to 33 mm on the upper surface, a curvature radius of 53 mm to 59 mm on the lower surface, a refractive index of 1.72 to 1.75, preferably 1.72916, and an Abbe number of 54.3 to 54.9, preferably 54.68474. The radius of curvature of the upper surface of the second meniscus positive lens 6 is 13mm-17mm, the radius of curvature of the lower surface is 18mm-21mm, the refractive index is 1.44-1.48, preferably 1.45846, and the Abbe number is 67.5-68.2, preferably 67.82143. With this structure, multiple tests are performed to optimize the specific values ​​of the radius of curvature, refractive index and Abbe number of the two surfaces of each lens, thereby further optimizing the optical path of the dual-band light beam, avoiding the influence of the focusing effect of the focusing objective lens 1 on the dual-band light beam when the radius of curvature, refractive index and Abbe number are too high or too low, thereby improving the processing quality and processing efficiency of laser processing.

[0062] The following Table 1 shows the specific values ​​of the surface shape, curvature radius, thickness, refractive index, Abbe number and net aperture of the biconcave negative lens 2, the first biconvex positive lens 3, the second biconvex positive lens 4, the first meniscus positive lens 5, the second meniscus positive lens 6, the window 15 and the water cavity 16.

[0063] Table 1

[0064]

[0065] The embodiment of the present invention tests the focusing objective lens 1 based on the data in Table 1 above, wherein the wavelength of the first light beam is 532 nm, the wavelength of the second light beam is 447 nm, the incident spot diameter of the focusing objective lens 1 is 30 mm, the image side numerical aperture is 0.52, the vertical phase difference is less than 20 μm, and the vertical axis chromatic aberration is less than 10 μm.

[0066] Figure 3 The point diagram of a focusing objective lens in the first embodiment is shown, wherein the image plane is 0 mm, the object plane is 0 degrees, the root mean square radius (RMS) of the first light beam and the second light beam is 0.314 μm, the Airy radius is 0.558 μm, the geostationary Earth Orbit Radius (GEO) is 0.665, the zoom size is 2, and the reference light is the principal light. Figure 3 It can be seen that the RMS radius of the first light beam and the second light beam are similar, and the focus of the first light beam and the second light beam on the image plane is relatively concentrated. Therefore, the above-mentioned focusing objective lens 1 of the embodiment of the present invention has good imaging quality and good focusing effect.

[0067] Figure 4 The light fan diagram of a focusing objective lens in the first embodiment is shown, where the object plane is 0 degrees, Px and Py are normalized pupil coordinates, representing the horizontal coordinate and vertical coordinate of the light on the pupil plane, respectively, ex and ey are the horizontal coordinate and vertical coordinate of the light on the image plane, respectively, where the dotted line represents the first light beam with a wavelength of 532nm, and the solid line represents the second light beam with a wavelength of 447nm. Figure 4 It can be seen that the curve of the first light beam and the curve of the second light beam have a smaller floating degree and a smaller difference between them. Therefore, the focusing objective lens 1 of the embodiment of the present invention has a smaller vertical axis aberration, better imaging quality and better focusing effect.

[0068] Figure 5 The focal shift diagram of a focusing objective lens in the first embodiment is shown, wherein the horizontal axis represents the focal shift, the vertical axis represents the wavelength, the maximum focal shift change is 13.9837 μm, the diffraction limit change is 1.573 μm, and the pupil area is 0. Figure 5 It can be seen that the focal positions of the first light beam and the second light beam are close, so the focusing objective lens 1 according to the embodiment of the present invention has small axial chromatic aberration, good imaging quality and good focusing effect.

[0069] Embodiment 2:

[0070] See also Figures 6 to 10An embodiment of the present invention provides a focusing objective lens, wherein the difference between the second embodiment and the first embodiment is that the dual-band light beam in the present embodiment includes a first light beam and a second light beam, the first light beam is green light, and the second light beam is near-infrared light; the curvature radius of the upper surface of the double concave negative lens 2 is -90mm~-85mm, the curvature radius of the lower surface is 70mm~80mm, the refractive index is 1.94~1.98, preferably 1.94595, and the Abbe number is 17.3~17.6, preferably 17.47243. The first biconvex positive lens 3 has an upper surface with a radius of curvature of 75 mm to 85 mm, a lower surface with a radius of curvature of -66 mm to -56 mm, a refractive index of 1.70 to 1.73, preferably 1.713, and an Abbe number of 53.5 to 54.1, preferably 53.83297; the second biconvex positive lens 4 has an upper surface with a radius of curvature of 51 mm to 60 mm, a lower surface that is flat, a refractive index of 1.67 to 1.70, preferably 1.69211, and an Abbe number of 54.1 to 54.9, preferably 54.5392. The radius of curvature of the upper surface of the first meniscus positive lens 5 is 26mm~32mm, the radius of curvature of the lower surface is 45mm~51mm, the refractive index is 1.72~1.75, preferably 1.72916, and the Abbe number is 54.3~54.9, preferably 54.68474; the radius of curvature of the upper surface of the second meniscus positive lens 6 is 13mm~17mm, the radius of curvature of the lower surface is 18mm~20mm, the refractive index is 1.44~1.48, preferably 1.45846, and the Abbe number is 67.5~68.2, preferably 67.82143. With this structure, the specific values ​​of the radius of curvature, refractive index and Abbe number of the two surfaces of each lens are optimized through multiple tests, so as to further optimize the optical path of the dual-band light beam, avoid the influence of the focusing effect of the focusing objective 1 on the dual-band light beam when the radius of curvature, refractive index and Abbe number are too high or too low, and thus improve the processing quality and processing efficiency of laser processing.

[0071] The following Table 2 shows the specific values ​​of the surface shape, curvature radius, thickness, refractive index, Abbe number and net aperture of the biconcave negative lens 2, the first biconvex positive lens 3, the second biconvex positive lens 4, the first meniscus positive lens 5, the second meniscus positive lens 6, the window 15 and the water cavity 16.

[0072] Table 2

[0073]

[0074] The embodiment of the present invention tests the focusing objective lens 1 based on the data in Table 2 above, wherein the wavelength of the first light beam is 532 nm, the wavelength of the second light beam is 1064 nm, the incident spot diameter of the focusing objective lens 1 is 30 mm, the image side numerical aperture is 0.52, the vertical phase difference is less than 20 μm, and the vertical axis chromatic aberration is less than 10 μm.

[0075] Figure 8 The point diagram of a focusing objective lens in the first embodiment is shown, wherein the image plane is 0 mm, the object plane is 0 degrees, the root mean square radius (RMS) of the first light beam and the second light beam is 0.691 μm, the Airy radius is 0.550 μm, the geostationary Earth Orbit Radius (GEO) is 1.313, the zoom size is 4, and the reference light is the principal light. Figure 8 It can be seen that the RMS radius of the first light beam and the second light beam are similar, and the focus of the first light beam and the second light beam on the image plane is relatively concentrated. Therefore, the above-mentioned focusing objective lens 1 of the embodiment of the present invention has good imaging quality and good focusing effect.

[0076] Fig. 9 The light fan diagram of a focusing objective lens in the first embodiment is shown, where the object plane is 0 degrees, Px and Py are normalized pupil coordinates, representing the horizontal coordinate and vertical coordinate of the light on the pupil plane, respectively, ex and ey are the horizontal coordinate and vertical coordinate of the light on the image plane, respectively, where the dotted line represents the first light beam with a wavelength of 532nm, and the solid line represents the second light beam with a wavelength of 1064nm. Fig. 9 It can be seen that the curve of the first light beam and the curve of the second light beam have a smaller floating degree and a smaller difference between them. Therefore, the focusing objective lens 1 of the embodiment of the present invention has a smaller vertical axis aberration, better imaging quality and better focusing effect.

[0077] Fig.10 The focal shift diagram of a focusing objective lens in the first embodiment is shown, wherein the horizontal axis represents the focal shift, the vertical axis represents the wavelength, the maximum focal shift change is 94.0006 μm, the diffraction limit change is 1.529 μm, and the pupil area is 0. Fig.10 It can be seen that the focal positions of the first light beam and the second light beam are close, so the focusing objective lens 1 according to the embodiment of the present invention has small axial chromatic aberration, good imaging quality and good focusing effect.

[0078] The beneficial effects of the second embodiment of the present invention and its various implementations can be analyzed by referring to the beneficial effects of the first embodiment and its various implementations, which will not be described in detail here.

[0079] Embodiment three:

[0080] The present embodiment provides a processing head for a dual-band micro-jet laser device, including a window, a water chamber, a nozzle, and a focusing objective lens as provided in the above-mentioned embodiment 1 or embodiment 2, the nozzle including a nozzle hole, the focusing objective lens, the window, the water chamber and the nozzle are arranged in sequence along the optical axis direction of the focusing objective lens, and the focusing objective lens is used to focus the dual-band light beam.

[0081] The beneficial effects of the third embodiment of the present invention and its various implementations can be analyzed by referring to the beneficial effects of the first embodiment and its various implementations, which will not be described in detail here.

[0082] Embodiment 4:

[0083] The present invention provides a dual-band micro-jet laser device, including a processing head of the dual-band micro-jet laser device provided in the third embodiment.

[0084] The beneficial effects of the fourth embodiment of the present invention and its various implementations can be analyzed with reference to the beneficial effects of the first embodiment and its various implementations, and will not be described in detail here.

[0085] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by the terms "upper", "lower", "front", "back", "left", "right", "inside", "outside", etc. are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0086] In addition, the terms "first", "second", and "third" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, a feature defined as "first", "second", and "third" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0087] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0088] The above contents are further detailed descriptions of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as falling within the protection scope of the present invention.

Claims

1. A focusing objective lens, used in a processing head of a dual-band micro-jet laser device, characterized in that: The processing head comprises a water cavity and a nozzle, the nozzle comprises a nozzle hole, the focusing objective lens, the water cavity and the nozzle are sequentially arranged along the optical axis direction of the focusing objective lens, the focusing objective lens is used to focus the dual-band light beam into the water cavity and the nozzle hole, and the focusing objective lens comprises a biconcave negative lens group, a biconvex positive lens group and a meniscus positive lens group which are sequentially coaxially arranged; The dual-band light beam is diverged by the double concave negative lens group and enters the double convex positive lens group, is converged by the double convex positive lens group and enters the meniscus positive lens group, and is converged by the meniscus positive lens group and passes through the water cavity and enters the spray hole; Wherein, the biconvex positive lens group comprises a first biconvex positive lens and a second biconvex positive lens; The biconcave negative lens group, the first biconvex positive lens, the second biconvex positive lens and the meniscus positive lens group are arranged in sequence, the dual-band light beam is diverged by the biconcave negative lens group and enters the first biconvex positive lens, is converged by the first biconvex positive lens and enters the second biconvex positive lens, is converged by the second biconvex positive lens and enters the meniscus positive lens group; Wherein, the meniscus positive lens group comprises a first meniscus positive lens and a second meniscus positive lens; The biconcave negative lens group, the first biconvex positive lens, the second biconvex positive lens, the first meniscus positive lens and the second meniscus positive lens are arranged in sequence, the dual-band light beam is converged by the second biconvex positive lens and enters the first meniscus positive lens, is converged by the first meniscus positive lens and enters the second meniscus positive lens, is converged by the second meniscus positive lens and passes through the water cavity and enters the spray hole; Wherein, the biconcave negative lens group comprises a biconcave negative lens, and the absolute value of the curvature radius of the upper surface of the biconcave negative lens is greater than the absolute value of the curvature radius of the lower surface of the biconcave negative lens; The refractive index of the biconcave negative lens is greater than the refractive index of the first biconvex positive lens, the refractive index of the first biconvex positive lens is greater than the refractive index of the second biconvex positive lens, the refractive index of the first meniscus positive lens is greater than the refractive index of the first biconvex positive lens, and the refractive index of the second meniscus positive lens is less than the refractive index of the first meniscus positive lens; The dual-band light beam comprises a first light beam and a second light beam, the first light beam is green light, and the second light beam is blue light; The curvature radius of the upper surface of the biconcave negative lens is -260 mm to -250 mm, the curvature radius of the lower surface is 75 mm to 85 mm, the refractive index is 1.92 to 1.96, and the Abbe number is 17.5 to 18.5; The first biconvex positive lens has an upper surface with a radius of curvature of 285 mm to 295 mm, a lower surface with a radius of curvature of -115 mm to -110 mm, a refractive index of 1.70 to 1.73, and an Abbe number of 53.5 to 54.1; The second biconvex positive lens has an upper surface with a radius of curvature of 55 mm to 65 mm, a lower surface with a radius of curvature of -150 mm to -140 mm, a refractive index of 1.67 to 1.70, and an Abbe number of 54.1 to 54.9; The first meniscus positive lens has an upper surface with a radius of curvature of 27 mm to 33 mm, a lower surface with a radius of curvature of 53 mm to 59 mm, a refractive index of 1.72 to 1.75, and an Abbe number of 54.3 to 54.9; The second meniscus positive lens has an upper surface with a radius of curvature of 13 mm to 17 mm, a lower surface with a radius of curvature of 18 mm to 21 mm, a refractive index of 1.44 to 1.48, and an Abbe number of 67.5 to 68.2; Alternatively, the dual-band light beam includes a first light beam and a second light beam, the first light beam is green light, and the second light beam is near-infrared light; The curvature radius of the upper surface of the biconcave negative lens is -90 mm to -85 mm, the curvature radius of the lower surface is 70 mm to 80 mm, the refractive index is 1.94 to 1.98, and the Abbe number is 17.3 to 17.6; The first biconvex positive lens has an upper surface with a radius of curvature of 75 mm to 85 mm, a lower surface with a radius of curvature of -66 mm to -56 mm, a refractive index of 1.70 to 1.73, and an Abbe number of 53.5 to 54.1; The curvature radius of the upper surface of the second biconvex positive lens is 51 mm to 60 mm, the lower surface is a plane, the refractive index is 1.67 to 1.70, and the Abbe number is 54.1 to 54.9; The first meniscus positive lens has an upper surface with a radius of curvature of 26 mm to 32 mm, a lower surface with a radius of curvature of 45 mm to 51 mm, a refractive index of 1.72 to 1.75, and an Abbe number of 54.3 to 54.9; The curvature radius of the upper surface of the second meniscus positive lens is 13 mm to 17 mm, the curvature radius of the lower surface is 18 mm to 20 mm, the refractive index is 1.44 to 1.48, and the Abbe number is 67.5 to 68.

2.

2. The focusing objective lens according to claim 1, characterized in that: The absolute value of the radius of curvature of the upper surface of the first biconvex positive lens is greater than the absolute value of the radius of curvature of the lower surface of the first biconvex positive lens, the absolute value of the radius of curvature of the upper surface of the second biconvex positive lens is smaller than the absolute value of the radius of curvature of the lower surface of the second biconvex positive lens, and the absolute value of the radius of curvature of the lower surface of the first biconvex positive lens is greater than the absolute value of the radius of curvature of the upper surface of the second biconvex positive lens.

3. The focusing objective lens according to claim 1, characterized in that: The radius of curvature of the upper surface of the first meniscus positive lens is smaller than the radius of curvature of the lower surface of the first meniscus positive lens, the radius of curvature of the upper surface of the second meniscus positive lens is smaller than the radius of curvature of the lower surface of the second meniscus positive lens, and the radius of curvature of the upper surface of the first meniscus positive lens is larger than the radius of curvature of the lower surface of the second meniscus positive lens.

4. The focusing objective lens according to claim 1, characterized in that: It also includes a lens barrel, wherein a first pressing ring, a second pressing ring, a first spacer ring, a second spacer ring and a third spacer ring are arranged in the lens barrel, and a first boss and a second boss are arranged on the side wall of the lens barrel; The second boss is used to support the second meniscus positive lens, and the first pressing ring is threadedly matched with the inner wall of the lens barrel to press the second meniscus positive lens onto the first boss; The first boss is used to support the first meniscus positive lens, the first spacer is arranged between the second biconvex positive lens and the first meniscus positive lens, the second spacer is arranged between the first biconvex positive lens and the second biconvex positive lens, the third spacer is arranged between the biconcave negative lens and the first biconvex positive lens, the second pressure ring and the third spacer are respectively located on both sides of the biconcave negative lens, and the second pressure ring is threadedly matched with the inner wall of the lens barrel to press the first meniscus positive lens onto the first boss.

5. A processing head for a dual-band micro-jet laser device, characterized in that: It comprises a window, a water cavity, a nozzle and a focusing objective lens as described in any one of claims 1 to 4, wherein the nozzle comprises a nozzle hole, and the focusing objective lens, the window, the water cavity and the nozzle are arranged in sequence along the optical axis direction of the focusing objective lens, and the focusing objective lens is used to focus a dual-band light beam.

Images