Dual-wavelength front focusing scanning galvanometer system

Abstract

The utility model provides a dual-wavelength front focusing scanning galvanometer system. The dual-wavelength front focusing scanning galvanometer system sequentially comprises a beam expander, a dynamic focusing mirror and a scanning galvanometer in the laser incidence direction. In the laser incidence direction, the beam expander sequentially comprises a first lens and a second lens, the first lens is a negative meniscus lens with the concave face facing the incidence laser, and the second lens is a positive meniscus lens. The dynamic focus lens sequentially comprises a third lens and a fourth lens, the third lens is a meniscus negative lens, and the fourth lens is a biconvex positive lens; the scanning galvanometer sequentially comprises an X-axis galvanometer and a Y-axis galvanometer. The air gap between the first lens and the second lens is 45.0 mm, the air gap between the fourth lens and the X-axis galvanometer is 52.27 mm, and the third lens can move between the second lens and the fourth lens to adjust the air gap between the third lens and the fourth lens, so that the maximum scanning breadth can reach 500mm * 500mm, and the X-axis galvanometer can work at the wavelength of 532nm and the wavelength of 1064nm at the same time. The obtained focusing light spot is small, the roundness of the focusing light spot is high, and the consistency of the light spot is good.

Description

Technical Field

[0001] The present application belongs to the field of laser processing, and specifically relates to a dual-wavelength front-focusing scanning galvanometer system. Background Art

[0002] The front-focusing scanning galvanometer system includes a beam expander, a dynamic focusing lens, and a galvanometer. The dynamic focusing lens and galvanometer work together to achieve different scanning ranges, working distances, and spot sizes under the same galvanometer conditions, meeting the needs of applications requiring small spots and large formats. Traditional front-focusing scanning galvanometer systems optimize the focusing and scanning of laser beams based on a single wavelength. However, in practical applications, it is often necessary to use lasers of different wavelengths simultaneously to achieve higher processing efficiency or a wider range of material compatibility. Utility Model Content

[0003] In view of this, the present application provides a dual-wavelength front-focusing scanning galvanometer system that can meet the needs of simultaneous dual-wavelength laser processing and has a larger scanning format.

[0004] A dual-wavelength front-focusing scanning galvanometer system includes a beam expander, a dynamic focusing mirror, and a scanning galvanometer in sequence along the laser incident direction;

[0005] The beam expander includes a first lens and a second lens in sequence along the incident direction of the laser, wherein the first lens is a negative meniscus lens with its concave surface facing the incident laser, and the second lens is a positive meniscus lens;

[0006] The dynamic focusing mirror includes a third lens and a fourth lens in sequence along the incident direction of the laser, the third lens is a meniscus negative lens, and the fourth lens is a biconvex positive lens;

[0007] The scanning galvanometer includes an X-axis galvanometer and a Y-axis galvanometer in sequence along the laser incident direction;

[0008] The air gap between the first lens and the second lens is 45.0 mm, the air gap between the fourth lens and the X-axis galvanometer is 52.57 mm, and the third lens is movable between the second lens and the fourth lens.

[0009] Preferably, the air gap between the third lens and the fourth lens can be adjusted within a range of 5.5 mm, so that the focus spot variation range is ≤7 μm.

[0010] Preferably, the air gap between the third lens and the fourth lens is 37.55 mm when the optical path is vertical, and the air gap between the third lens and the fourth lens is 32.25 mm at the maximum optical path inclination angle.

[0011] Preferably, the radius of curvature of the entrance surface S1 of the first lens is -27.77 mm, the radius of curvature of the exit surface S2 of the first lens is -66.48 mm, the central thickness of the first lens is 9.70 mm, the material is SF57, the refractive index N d1 = 1.85, and the Abbe number V d1 = 23.8;

[0012] The radius of curvature of the entrance surface S3 of the second lens is -333.60 mm, the radius of curvature of the exit surface S4 of the second lens is -72.78 mm, the central thickness of the second lens is 9.52 mm, the material is N-LAK34, the refractive index N d2 = 1.73, and the Abbe number V d2 = 54.5;

[0013] The radius of curvature of the entrance surface S5 of the third lens is 3050.97 mm, the radius of curvature of the exit surface S6 of the third lens is 132.40 mm, the central thickness of the third lens is 13.48 mm, the material is N-LAK34, the refractive index N d3 = 1.73, and the Abbe number V d3 = 54.5;

[0014] The radius of curvature of the entrance surface S7 of the fourth lens is 194.67 mm, the radius of curvature of the exit surface S8 of the fourth lens is -163.24 mm, the central thickness of the fourth lens is 5.11 mm, the material is N-PK52A, the refractive index N d4 = 1.50, and the Abbe number V d4 = 81.6.

[0015] Preferably, the air gap between the X-axis galvanometer and the Y-axis galvanometer is 25.25 mm, and the distance between the Y-axis galvanometer and the workbench surface is 750 mm.

[0016] Preferably, the X-axis galvanometer and the Y-axis galvanometer are both plane mirrors, and the mechanical deflection angle is -10°-10°.

[0017] Preferably, the magnification of the beam expander is 2x.

[0018] Preferably, the scanning field of the front focusing scanning galvanometer system is 500 mm x 500 mm.

[0019] Preferably, the entrance pupil diameter of the laser beam is 10 mm.

[0020] The beneficial effects of the present application are: the air gap between the first lens and the second lens is 45.0 mm, the air gap between the fourth lens and the X-axis galvanometer is 52.27 mm, and by adjusting the air gap between the third lens and the fourth lens, the scanning format of the front focusing scanning galvanometer system can reach a maximum of 500 mm × 500 mm, and can work at wavelengths of 532 nm and 1064 nm at the same time. The obtained focused spot is small, the focused spot has high roundness, the spot consistency is good, and the full-format Strehl ratio is higher than 0.98. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following briefly introduces the drawings required for use in the embodiments or descriptions of the prior art. Obviously, the drawings described below are merely embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without any creative work.

[0022] The structures, proportions, sizes, etc. depicted in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read. They are not used to limit the conditions for the implementation of this application and therefore have no substantive technical significance. Any structural modifications, changes in proportional relationships, or adjustments in size should still fall within the scope of the technical contents disclosed in this application without affecting the effects and purposes that can be achieved by this application.

[0023] Figure 1 Schematic diagram of the optical path structure of the dual-wavelength front-focusing scanning galvanometer system provided in this application;

[0024] Figure 2 Schematic diagram of the optical path structure of the beam expander in the dual-wavelength front-focusing scanning galvanometer system;

[0025] Figure 3 Schematic diagram of the optical path structure of the dynamic focusing mirror in the dual-wavelength front-focusing scanning galvanometer system;

[0026] Figure 4 This is a spot diagram of different working formats of the dual-wavelength front-focusing scanning galvanometer system;

[0027] Figure 5 This is the point spread function diagram of the dual-wavelength front-focusing scanning galvanometer system with different working formats.

[0028] In the figure: 1-first lens; 2-second lens; 3-third lens; 4-fourth lens. DETAILED DESCRIPTION

[0029] The embodiments of the present application will be described below in detail with the accompanying drawings. It is obvious that the described embodiments are only a part of the embodiments of the present application, but not all the embodiments. Based on the embodiments of the present application, all the other embodiments obtained by those skilled in the art without creative work are within the scope of the present application.

[0030] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the present application will be further described in detail below with the accompanying drawings and specific embodiments.

[0031] Reference Figure 1-3 The present application provides a dual-wavelength pre-focusing scanning galvanometer system, which comprises, in order along the laser incident direction, an expander lens, a dynamic focusing lens and a scanning field lens. Wherein:

[0032] As Figure 2 shown, along the laser incident direction, the expander lens comprises, in order, a first lens 1 and a second lens 2, the first lens 1 is a concave moon-shaped negative lens facing the incident laser, the second lens 2 is a concave moon-shaped positive lens, and the air gap between the first lens 1 and the second lens 2 is fixed at 45.0mm.

[0033] The magnification of the expander lens of the present embodiment is 2x, and the laser beam passing through the expander lens can improve the collimation of the laser, enlarge the beam diameter and reduce the size of the exit spot.

[0034] In the preferred embodiment, the radius of curvature of the incident surface S1 of the first lens 1 is -27.77mm, the radius of curvature of the exit surface S2 of the first lens 1 is -66.48mm, the central thickness of the first lens 1 is 9.70mm, the material is SF57, the refractive index Nd1=1.85, and the Abbe number Vd1=23.8;

[0035] The radius of curvature of the incident surface S3 of the second lens 2 is -333.60mm, the radius of curvature of the exit surface S4 of the second lens 2 is -72.78mm, the central thickness of the second lens 2 is 9.52mm, the material is N-LAK34, the refractive index Nd2=1.73, and the Abbe number Vd2=54.5.

[0036] As Figure 3 shown, along the laser incident direction, the dynamic focusing lens comprises, in order, a third lens 3 and a fourth lens 4, the third lens 3 is a concave moon-shaped negative lens, and the fourth lens 4 is a double-convex positive lens. The third lens 3 can move between the second lens 2 and the fourth lens 4, thereby changing the air gap between the third lens 3 and the fourth lens 4.

[0037] In a preferred embodiment, the radius of curvature of the incident surface S5 of the third lens 3 is 3050.97 mm, the radius of curvature of the exit surface S6 of the third lens 3 is 132.40 mm, the center thickness of the third lens 3 is 13.48 mm, the material is N-LAK34, the refractive index Nd3=1.73, and the Abbe number Vd3=54.5;

[0038] The curvature radius of the incident surface S7 of the fourth lens 4 is 194.67 mm, the curvature radius of the exit surface S8 of the fourth lens 4 is -163.24 mm, the center thickness of the fourth lens 4 is 5.11 mm, the material is N-PK52A, the refractive index Nd4=1.50, and the Abbe number Vd4=81.6.

[0039] Along the laser incident direction, the scanning galvanometer includes an X-axis galvanometer and a Y-axis galvanometer in sequence. The air gap between the fourth lens 4 and the X-axis galvanometer is 52.57 mm, the air gap between the X-axis galvanometer and the Y-axis galvanometer is 25.25 mm, and the distance between the Y-axis galvanometer and the work table is 750 mm.

[0040] In this embodiment, the distances between the first lens 1, the second lens 2, the fourth lens 4 and the X-axis galvanometer, the X-axis galvanometer and the Y-axis galvanometer, and the Y-axis galvanometer and the worktable are all fixed. By changing the air gap between the third lens 3 and the fourth lens 4, the defocus error on the scanning plane can be compensated, and the scanning galvanometer can be scanned in the X and Y directions, so that the synchronous focusing of the laser beam is maintained at different wavelengths, ensuring high-precision and high-quality processing effects when scanning large formats.

[0041] In a preferred embodiment, the air gap between the third lens 3 and the fourth lens 4 is adjusted within a range of 5.5 mm, so that the focus spot variation range is ≤7 μm. Specifically, when the light path after passing through the dual-wavelength front-focusing scanning galvanometer system acts vertically on the work surface, the air gap between the third lens 3 and the fourth lens 4 is 37.55 mm; when the light beam after passing through the dual-wavelength front-focusing scanning galvanometer system acts obliquely on the work surface, and at the maximum light path inclination angle, the air gap between the third lens 3 and the fourth lens 4 is 32.25 mm. It can be understood that the air gap between the third lens 3 and the fourth lens 4 varies between 32.25 and 37.55 mm. When the air gap between the third lens 3 and the fourth lens 4 is 32.25 mm, the maximum scanning format of 500 mm × 500 mm is reached.

[0042] In this embodiment, both the X-axis galvanometer mirror and the Y-axis galvanometer mirror are plane reflective mirrors, and the mechanical deflection angles are both between -10° and 10°, and the entrance pupil diameter of the laser beam is 10 mm.

[0043] refer to Figure 1The laser beam passes through the beam expander, dynamic focusing mirror and scanning field mirror in sequence and acts on the workbench. The focusing positions of the dynamic focusing mirror and scanning galvanometer in different states are given as examples.

[0044] Figure 3 Schematic diagrams of different air gaps between the third lens 3 and the fourth lens 4 are given as examples. From top to bottom, they are structural schematic diagrams when the air gap between the third lens 3 and the fourth lens 4 is 37.55 mm, 35.13 mm, 35.05 mm and 32.25 mm respectively.

[0045] Among them, the different states of the dynamic focusing mirror and the scanning field mirror refer to, for example, the air gap between the third lens 3 and the fourth lens 4 is 37.55 mm, and the corresponding mechanical deflection angles of the X-axis galvanometer and the Y-axis galvanometer are both 0°; for another example, the air gap between the third lens 3 and the fourth lens 4 is 35.13 mm, and the corresponding mechanical deflection angle of the X-axis galvanometer is -8.29°, and the mechanical deflection angle of the Y-axis galvanometer is 0°; for another example, the air gap between the third lens 3 and the fourth lens 4 is 35.05 mm, and the corresponding mechanical deflection angle of the X-axis galvanometer is 0°, and the mechanical deflection angle of the Y-axis galvanometer is -8.55°; for another example, the air gap between the third lens 3 and the fourth lens 4 is 32.25 mm, and the corresponding mechanical deflection angle of the X-axis galvanometer is -8.54°, and the mechanical deflection angle of the Y-axis galvanometer is -9.25°.

[0046] In order to better illustrate the effect of this embodiment, refer to Figure 4-5 . Figure 4 Spot diagrams of different sizes are given as examples, and the results show that the spot radius at different focus positions is within the Airy disk. Figure 5 The point spread function diagrams of different working formats are given as examples, and the results show that the Strehl ratios at different focus positions are all greater than 0.98.

[0047] The dual-wavelength front-focusing scanning galvanometer system provided in this application can operate at wavelengths of 532nm and 1064nm simultaneously, with a maximum scanning working area of ​​500mm×500mm. The obtained focused light spot is small, the roundness of the focused light spot is high, and the consistency is good. The full-width Strehl ratio is higher than 0.98°.

[0048] The various embodiments in this specification are described in a progressive, parallel, or combined manner. Each embodiment focuses on the differences from other embodiments, and reference can be made to the common and similar parts between the various embodiments. For the devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple. For relevant parts, refer to the description of the methods.

[0049] It should be noted that in the description of this application, it should be understood that the terms "upper", "lower", "top", "bottom", "inner", "outer", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are only used to facilitate the description of this application and simplify the description. They do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, they should not be understood as limitations on this application. When a component is considered to be "connected" to another component, it can be directly connected to the other component or there may be a centrally located component.

[0050] It should also be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises", "includes" or any other variations thereof are intended to cover non-exclusive inclusion, so that an article or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such article or device. In the absence of further limitations, an element defined by the phrase "comprises a ..." does not exclude the presence of other identical elements in the article or device comprising the above elements.

[0051] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present application. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application is not limited to the embodiments shown herein, but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A dual-wavelength front-focusing scanning galvanometer system, characterized in that: Along the laser incident direction, it includes a beam expander, a dynamic focusing mirror and a scanning galvanometer mirror; The beam expander includes a first lens and a second lens in sequence along the incident direction of the laser, wherein the first lens is a negative meniscus lens with its concave surface facing the incident laser, and the second lens is a positive meniscus lens; The dynamic focusing mirror includes a third lens and a fourth lens in sequence along the incident direction of the laser, the third lens is a meniscus negative lens, and the fourth lens is a biconvex positive lens; The scanning galvanometer includes an X-axis galvanometer and a Y-axis galvanometer in sequence along the laser incident direction; The air gap between the first lens and the second lens is 45.0 mm, the air gap between the fourth lens and the X-axis galvanometer is 52.57 mm, and the third lens is movable between the second lens and the fourth lens.

2. The dual-wavelength front-focusing scanning galvanometer system according to claim 1, characterized in that: The air gap between the third lens and the fourth lens is adjusted within a range of 5.5 mm, so that the focus spot variation range is ≤7 μm.

3. The dual-wavelength front-focusing scanning galvanometer system according to claim 2, characterized in that: When the optical path is vertical, the air gap between the third lens and the fourth lens is 37.55 mm. When the optical path is tilted at the maximum angle, the air gap between the third lens and the fourth lens is 32.25 mm.

4. The dual-wavelength front-focusing scanning galvanometer system according to claim 1, characterized in that: The radius of curvature of the incident surface S1 of the first lens is -27.77 mm, the radius of curvature of the exit surface S2 of the first lens is -66.48 mm, the center thickness of the first lens is 9.70 mm, the material is SF57, the refractive index Nd1=1.85, and the Abbe number Vd1=23.8; The curvature radius of the incident surface S3 of the second lens is -333.60 mm, the curvature radius of the exit surface S4 of the second lens is -72.78 mm, the center thickness of the second lens is 9.52 mm, the material is N-LAK34, the refractive index Nd2=1.73, and the Abbe number Vd2=54.5; The radius of curvature of the incident surface S5 of the third lens is 3050.97 mm, the radius of curvature of the exit surface S6 of the third lens is 132.40 mm, the center thickness of the third lens is 13.48 mm, the material is N-LAK34, the refractive index Nd3=1.73, and the Abbe number Vd3=54.5; The curvature radius of the incident surface S7 of the fourth lens is 194.67 mm, the curvature radius of the exit surface S8 of the fourth lens is -163.24 mm, the center thickness of the fourth lens is 5.11 mm, the material is N-PK52A, the refractive index Nd4=1.50, and the Abbe number Vd4=81.

6.

5. A dual-wavelength front-focusing scanning galvanometer system according to any one of claims 1 to 4, characterized in that: The air gap between the X-axis galvanometer and the Y-axis galvanometer is 25.25 mm, and the distance between the Y-axis galvanometer and the work surface is 750 mm.

6. A dual-wavelength front-focusing scanning galvanometer system according to any one of claims 1 to 4, characterized in that: The X-axis galvanometer and the Y-axis galvanometer are both plane reflectors, and the mechanical deflection angles are both between -10° and 10°.

7. A dual-wavelength front-focusing scanning galvanometer system according to any one of claims 1 to 4, characterized in that: The magnification of the beam expander is 2x.

8. A dual-wavelength front-focusing scanning galvanometer system according to any one of claims 1 to 4, characterized in that: The scanning format of the front focusing scanning galvanometer system is 500 mm×500 mm.

9. A dual-wavelength front-focusing scanning galvanometer system according to any one of claims 1 to 4, characterized in that: The entrance pupil diameter of the laser beam is 10 mm.

Images