Optical dynamic focusing module and three-dimensional scanning system

Abstract

The utility model discloses an optical dynamic focusing module and a three-dimensional scanning system. The optical dynamic focusing module comprises an optical assembly, and the optical assembly at least comprises a first off-axis parabolic mirror and a second off-axis parabolic mirror which are symmetrically arranged. The off-axis paraboloid of the first off-axis paraboloid mirror and the off-axis paraboloid of the second off-axis paraboloid mirror are arranged back to back; the first reflecting mirror is used for receiving the laser beam refracted by the first off-axis parabolic mirror and reflecting the laser beam towards the second reflecting mirror, and the second reflecting mirror can reflect the received laser beam to the second off-axis parabolic mirror for secondary refraction; wherein the first reflecting mirror and the second reflecting mirror are configured to rotate synchronously; the 3D galvanometer can solve the problems that a traditional 3D galvanometer is low in mechanical transmission efficiency, the refraction angle of a laser beam is limited to a certain degree, and part of light cannot completely pass through the 3D galvanometer.

Description

Technical Field

[0001] The utility model relates to the field of laser processing, and in particular to an optical dynamic focusing module and a three-dimensional scanning system. Background Art

[0002] In the application fields of laser marking, laser engraving, stage lighting control, laser drilling, etc., the galvanometer plays an irreplaceable role. As a key component in the field of laser processing, the market demand for 3D galvanometer is growing day by day. As an important branch of galvanometer technology, the application prospect of 3D galvanometer is even broader. In high-end application fields, such as wafer cutting, photovoltaic scribing, remote welding, fine removal of glass film, laser cladding in the aerospace industry, PCB processing, etc., these fields have extremely high performance requirements for 3D galvanometers, which has also promoted the continuous innovation and progress of 3D galvanometer technology.

[0003] However, the traditional 3D galvanometer contains multiple components, such as concave lenses, convex lenses, connecting rods, guide rails, etc., which increases the spatial volume of the optical system and reduces the efficiency of the mechanical transmission system. In addition, the lens-type dynamic beam expansion system has certain limitations on the refraction angle of light, which will cause some light to be unable to pass completely. Utility Model Content

[0004] The utility model aims to solve the above technical problems, namely, the traditional 3D galvanometer has low mechanical transmission efficiency and certain limitations on the refraction angle of the laser beam, which will cause some light to be unable to pass completely.

[0005] In a first aspect, the utility model provides an optical dynamic focusing module, comprising an optical component for changing a divergence angle on an off-axis laser beam optical path to achieve dynamic focusing, the optical component comprising at least:

[0006] A first off-axis parabolic mirror and a second off-axis parabolic mirror are symmetrically arranged, wherein the off-axis parabola of the first off-axis parabolic mirror and the off-axis parabola of the second off-axis parabola are arranged opposite to each other;

[0007] a first reflector and a second reflector, wherein the first reflector is used to receive the laser beam refracted by the first off-axis parabolic mirror and reflect the laser beam toward the second reflector, and the second reflector is capable of reflecting the received laser beam to the second off-axis parabolic mirror for secondary refraction;

[0008] Wherein, the first reflector and the second reflector are configured to rotate synchronously so that: the center of the first reflector approaches or moves away from the focusing point of the first off-axis parabolic mirror, and then the laser beam reflected by the second reflector and refracted by the second off-axis parabolic mirror is in a slightly diffused state, a collimated state or a slightly focused state.

[0009] By controlling the first reflector and the second reflector to rotate synchronously, the first reflector is moved close to or away from the focusing point of the first off-axis parabolic mirror, so that the laser beam refracted by the second off-axis parabolic mirror can be in a micro-diffusion state, a collimated state or a micro-focused state; through this non-mechanical transmission type of dynamic optical beam expansion, the mechanical gap is effectively reduced, the stability of the dynamic optical beam expansion is increased, and the characteristics of high speed and high precision are achieved.

[0010] In the preferred technical solution of the above optical dynamic focusing module, the first reflector and the second reflector are arranged on a crank mirror seat, and the first reflector and the second reflector form a reflection inclination angle along a direction perpendicular to the crank mirror seat.

[0011] In the preferred technical solution of the above optical dynamic focusing module, the crank mirror mount is driven by a driving motor so that the first reflector and the second reflector rotate synchronously.

[0012] In the preferred technical solution of the above optical dynamic focusing module, the material of the first reflector and / or the second reflector is silicon carbide.

[0013] In the preferred technical solution of the above optical dynamic focusing module, the optical component is arranged in a housing, and the laser beam is incident on the off-axis parabola of the first off-axis parabola mirror through a light entrance hole of the housing.

[0014] In the preferred technical solution of the above optical dynamic focusing module, along the optical path of the laser beam, a plane window mirror and a beam shaper are sequentially arranged in the light entrance hole, wherein the plane window mirror, the beam shaper and the light entrance hole are coaxially arranged.

[0015] In the preferred technical solution of the above optical dynamic focusing module, the first off-axis parabolic mirror is arranged on the shell through a first adjustment seat, and the second off-axis parabolic mirror is arranged on the shell through a second adjustment seat.

[0016] In a second aspect, the utility model also provides a three-dimensional scanning system, which includes the above-mentioned optical dynamic focusing module and a two-dimensional scanning module arranged on one side of the second off-axis parabolic mirror, and the two-dimensional scanning module includes at least a focusing structure and an X-axis galvanometer and a Y-axis galvanometer; wherein the focusing structure is used to focus the laser beam refracted by the second off-axis parabolic mirror or the Y-axis galvanometer to form a focused laser beam, and the X-axis galvanometer and the Y-axis galvanometer are used to receive the laser beam refracted by the second off-axis parabolic mirror or the focused laser beam, and emit the laser beam or the focused laser beam vertically below the two-dimensional scanning module to present a micro-diffusion state, a collimated state or a micro-convergence state.

[0017] In the preferred technical solution of the above-mentioned three-dimensional scanning system, the focusing structure includes a focusing mirror arranged between the X-axis galvanometer and the second off-axis parabolic mirror, and a non-planar window mirror arranged below the X-axis galvanometer and the Y-axis galvanometer for optically processing the focused laser beam.

[0018] In the preferred technical solution of the above three-dimensional scanning system, the focusing structure includes a field mirror arranged below the X-axis galvanometer and the Y-axis galvanometer and used to focus the laser beam.

[0019] The beneficial effect of the utility model is that by driving the motor to control the crank mirror seat to rotate clockwise or counterclockwise, the focused laser beam emitted by the two-dimensional scanning module can be in a slightly focused state, a zero focus state or a negative defocus state. The non-mechanical transmission dynamic optical beam expansion of the crank mirror seat driven by the driving motor effectively reduces the mechanical gap, increases the stability of the dynamic optical beam expansion, and has the characteristics of high speed and high precision. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a schematic diagram of a first embodiment of a focusing structure;

[0021] Figure 2 It is a schematic diagram showing that the upper housing and the lower housing are separated in the first embodiment of the focusing structure;

[0022] Figure 3 Schematic diagram of the optical dynamic focusing module and the two-dimensional scanning module in the first embodiment of the focusing structure Figure 1 ;

[0023] Figure 4 Schematic diagram of the optical dynamic focusing module and the two-dimensional scanning module in the first embodiment of the focusing structure Figure 2 ;

[0024] Figure 5 is a bottom view of the upper shell;

[0025] Figure 6 is a schematic diagram of a second embodiment of a focusing structure;

[0026] Figure 7 Schematic diagram of an optical dynamic focusing module and a two-dimensional scanning module in a second embodiment of a focusing structure Figure 2 ;

[0027] Figure 8 is a working principle diagram of the first off-axis parabolic mirror;

[0028] Fig. 9 It is a schematic diagram of the operation of the first off-axis parabolic mirror and the second off-axis parabolic mirror;

[0029] Fig.10is a schematic diagram of a laser beam in a collimated state;

[0030] Fig.11 is a schematic diagram of a laser beam in a micro-focusing state;

[0031] Fig.12 Schematic diagram of the laser beam in a slightly diffused state;

[0032] In the figure:

[0033] A first off-axis parabolic mirror 101, a second off-axis parabolic mirror 102, a first reflector 103, a second reflector 104, a crank mirror base 2, a drive motor 3, a housing 4, an upper housing 41, a lower housing 42, a plane window mirror 5, a beam shaper 6, a DB9 power supply interface 71, a DB15 XY2-100 communication interface 72, and a 3D DA board 73;

[0034] X-axis galvanometer 81 , Y-axis galvanometer 82 , focusing mirror 91 , aspherical window mirror 92 , and field mirror 93 . DETAILED DESCRIPTION

[0035] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the protection scope of the present invention.

[0036] It should be noted that in the description of the present invention, the terms "upper", "lower", "left", "right", "front", "rear" and the like indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings, which are only for the convenience of description, and do not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0037] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "disposed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0038] like Figures 1 to 12As shown, the optical dynamic focusing module of the utility model includes an optical component for changing the divergence angle of the laser beam on the off-axis laser beam optical path to achieve dynamic focusing, and the optical component at least includes: a first off-axis parabolic mirror 101 and a second off-axis parabolic mirror 102 arranged symmetrically, the off-axis parabola of the first off-axis parabolic mirror 101 and the off-axis parabola of the second off-axis parabolic mirror 102 are arranged opposite to each other; a first reflector 103 and a second reflector 104, the first reflector 103 is used to receive the refracted laser beam of the first off-axis parabolic mirror 101 The laser beam is received and reflected toward the second reflector 104, and the second reflector 104 can reflect the received laser beam to the second off-axis parabolic mirror 102 for secondary refraction; wherein the first reflector 103 and the second reflector 104 are configured to rotate synchronously so that: the center of the first reflector 103 is close to or away from the focusing point of the first off-axis parabolic mirror 101, and then the laser beam reflected by the second reflector 104 and refracted by the second off-axis parabolic mirror 102 is in a slightly diffused state, a collimated state or a slightly focused state.

[0039] See also Figure 4 , Figure 7 , Fig.10 , Fig.11 , Fig.12 The off-axis parabola of the first off-axis parabola mirror 101 and the off-axis parabola of the second off-axis parabola mirror 102 are arranged opposite to each other, the first reflector 103 and the second reflector 104 are arranged vertically at 90 degrees, the center of the mirror surface of the first reflector 103 corresponds to the off-axis parabola of the first off-axis parabola mirror 101, and the center of the mirror surface of the second reflector 104 corresponds to the off-axis parabola of the second off-axis parabola mirror 102; when the laser beam is horizontally incident on the first off-axis parabola mirror 101 After passing through the off-axis parabola, the laser beam is refracted by the off-axis parabola, and is received by the first reflector 103 and reflected toward the second reflector 104. The second reflector 104 receives the laser beam and reflects it toward the off-axis parabola of the second off-axis parabola mirror 102. The laser beam is finally refracted out through the off-axis parabola of the second off-axis parabola mirror 102. The laser beam refracted by the second off-axis parabola mirror 102 is consistent with the propagation direction of the laser beam incident to the first off-axis parabola mirror 101 and is coaxially arranged.

[0040] See also Figure 8 , Fig. 9 , Figures 10 to 12 After the collimated laser beam is incident on the first off-axis parabolic mirror 101 along the optical axis, the collimated laser beam will be refracted 90° by the first off-axis parabolic mirror 101, thereby forming a focusing point along the focusing optical axis. When the collimated laser beam exceeds the focusing point, the collimated laser beam will produce a divergent effect.

[0041] See also Figure 4 , Figure 7 , Fig.10 , Fig.11 , Fig.12 , the size of the first off-axis parabolic mirror 101 is smaller than that of the second off-axis parabolic mirror 102. Specifically, the size of the first off-axis parabolic mirror 101 is 12.7 mm, and the size of the second off-axis parabolic mirror 102 is 25.4 mm. The focal length of the first off-axis parabolic mirror 101 is 1 / 2 of the focal length of the second off-axis parabolic mirror 102, and the focal length ratio of the two corresponds to the beam expansion ratio of the laser beam.

[0042] See Figure 4 , Figure 7 , Fig.10 , Fig.11 , Fig.12 , the size of the first reflector 103 is smaller than that of the second reflector 104. When the first reflector 103 and the second reflector 104 rotate synchronously, the first reflector 103 is farther from the rotation reference axis, and the second reflector 104 is closer to the rotation reference axis; by setting the size of the first reflector 103 to be smaller than that of the second reflector 104, the centrifugal forces of the first reflector 103 and the second reflector 104 during synchronous rotation can be balanced. At the same time, since the focal length of the first off-axis parabolic mirror 101 is smaller and the focal point is in front of the first reflector 103, the laser beam refracted by the first off-axis parabolic mirror 101 will first be focused and then diverge, and the reflected light spot formed on the first reflector 103 by the diverging laser beam is smaller than the reflected light spot on the second reflector 104, thus achieving the effect of beam expansion. Specifically, the light spot on the first reflector 103 is 1 / 2 of the light spot on the second reflector 104.

[0043] See Figure 11 to Figure 12 , by controlling the synchronous rotation of the first reflector 103 and the second reflector 104, the first reflector 103 can be made to approach or move away from the focal point of the first off-axis parabolic mirror 101, so that the laser beam refracted by the second off-axis parabolic mirror 102 can present a slightly diffused state, a collimated state, or a slightly converged state.

[0044] See Figure 11 to Figure 12 , the focal length of the first off-axis parabolic mirror 101 is f, the focal length of the second off-axis parabolic mirror 102 is f', and the optical path of the laser beam passing through the first off-axis parabolic mirror 101, the first reflector 103, the second reflector 104, and the second off-axis parabolic mirror 102 is s. When s = f + f', it is in the Z-axis optical zero position, and the laser beam refracted by the second off-axis parabolic mirror 102 is in a collimated beam state; when s > f + f', it is in the Z-axis optical positive offset, and the laser beam refracted by the second off-axis parabolic mirror 102 is in a slightly converged state; when s < f + f', it is in the Z-axis optical negative offset, and the laser beam refracted by the second off-axis parabolic mirror 102 is in a slightly diffused state.

[0045] See Fig.11 Rotate the first reflector 103 and the second reflector 104 synchronously counterclockwise, so that the first reflector 103 is relatively far away from the focal point of the laser beam refracted by the first off-axis parabolic mirror 101, making the light spot incident on the first reflector 103 relatively located at the lower position of the first reflector 103, and the optical path s of the laser beam > f + f'; at this time, since the light spot incident on the first reflector 103 is far from the focal point of the first off-axis parabolic mirror 101, the laser beam that is first focused and then diverged can fall on the first reflector 103 more, and a larger light spot is formed. Then, after the laser beam is reflected by the first reflector 103, the light spot of the laser beam incident on the second reflector 104 is relatively located above the second reflector 104, and the light spot on the second reflector 104 is twice that of the light spot on the first reflector 103, so that the light spot area of the laser beam reflected to the second off-axis parabolic mirror 102 is twice that of the light spot incident on the first off-axis parabolic mirror 101, realizing that the laser beam refracted by the second off-axis parabolic mirror 102 can be in a slightly converging state, so that the laser beam is in a positive defocus state relative to the focal plane after being emitted by the two-dimensional scanning module (the focal point is above the focal plane).

[0046] See Fig.10 Based on the laser beam being in a converging state, rotate the first reflector 103 and the second reflector 104 clockwise, so that the first reflector 103 is relatively close to the focal point of the laser beam refracted by the first off-axis parabolic mirror 101, making the light spot incident on the first reflector 103 relatively located in the middle position, and the optical path s of the laser beam = f + f'. At this time, the light spot reflected from the first reflector 103 to the second reflector 104 is relatively located in the middle, the light spot reflected to the second off-axis parabolic mirror 102 is relatively located in the middle, and the laser beam refracted by the second off-axis parabolic mirror 102 is in a collimated state, so that the laser beam is in a zero defocus state relative to the focal plane after being emitted by the two-dimensional scanning module (the focal point coincides with the focal plane).

[0047] See 12. Based on the laser beam being in a collimated state, continue to rotate the first reflector 103 and the second reflector 104 clockwise, so that the first reflector 103 is further close to the focal point of the laser beam refracted by the first off-axis parabolic mirror 101, making the light spot incident on the first reflector 103 relatively located at the upper position, and the optical path s of the laser beam < f + f'; at this time, the light spots on the first reflector 103, the second reflector 104, and the second off-axis parabolic mirror 102 are all smaller than the corresponding light spots in each position in the collimated state, and then realize that the laser beam refracted by the second off-axis parabolic mirror 102 can present a slightly diffused state, so that the laser beam is in a negative defocus state relative to the focal plane after being emitted by the two-dimensional scanning module (the focal point is below the focal plane).

[0048] It should be noted that, whether the first reflector 103 and the second reflector 104 are rotated counterclockwise or clockwise, they are all described from a bottom view perspective. If described from a top view perspective, the counterclockwise and clockwise directions need to be swapped.

[0049] In one or more embodiments, the first reflector 103 and the second reflector 104 are arranged on the crank mirror base 2 , and along a direction perpendicular to the crank mirror base 2 , the first reflector 103 and the second reflector 104 form a reflection inclination angle.

[0050] See also Figure 4 , Figure 7 , Fig.10 , Fig.11 , Fig.12 The first reflector 103 and the second reflector 104 are arranged to be perpendicular to each other at 90° in a direction perpendicular to the crank mirror base 2, and the reflection inclination angle formed by the first reflector 103 and the second reflector 104 is 90°.

[0051] It should be noted that the first reflector 103 is relatively far away from the rotation center axis on the crank mirror seat 2, and the second reflector 104 is relatively close to the rotation center axis on the crank mirror seat 2, so that the first reflector 103 is relatively close to the focusing point of the first off-axis parabolic mirror 101, and the second reflector 104 is relatively far away from the focusing point of the first off-axis parabolic mirror 101, so that the laser beam refracted by the first off-axis parabolic mirror 101 is first focused and then diverged to the first reflector 103, so that the reflected light spot on the first reflector 103 is smaller than the light spot on the second reflector 104, thereby, the size of the first reflector 103 is reasonably configured to be smaller than the size of the second reflector 104.

[0052] In one or more embodiments, the crank mirror base 2 is driven by the driving motor 3 to make the first reflector 103 and the second reflector 104 rotate synchronously.

[0053] The driving motor 3 is a galvanometer motor, which drives the crank mirror base 2 to rotate by the driving motor 3, and then controls the first reflector 103 and the second reflector to rotate synchronously. This can effectively reduce the complexity of the optical-mechanical structure, reduce mechanical friction, and improve the motion efficiency and stability of the dynamic optical beam expansion system, so that the optical dynamic focusing system of the present application can obtain high speed and high precision characteristics.

[0054] In one or more embodiments, the first reflector 103 and / or the second reflector 104 is made of silicon carbide.

[0055] In one or more embodiments, the optical component is configured in the shell 4, and the laser beam is incident on the off-axis parabola of the first off-axis parabolic mirror 101 through the light entrance hole of the shell 4; along the optical path of the laser beam, a plane window mirror 5 and a beam shaper 6 are sequentially arranged in the light entrance hole, wherein the plane window mirror 5 is coaxially arranged with the beam shaper 6 and the light entrance hole; the first off-axis parabolic mirror 101 is configured on the shell 4 through a first adjustment seat, and the second off-axis parabolic mirror 102 is configured on the shell 4 through a second adjustment seat.

[0056] See also Figures 1 to 7 , Fig. 9 The optical assembly and the driving motor 3, the crank mirror seat 2, the first adjustment seat and the second adjustment seat are all arranged in the housing 4. The optical assembly includes a first off-axis parabolic mirror 101, a first reflector 103, a second reflector 104 and a second off-axis parabolic mirror 102. By adjusting the positions of the first adjustment seat and the second adjustment seat in the housing 4, the focusing points of the first off-axis parabolic mirror 101 and the second off-axis parabolic mirror 102 are located in the same plane as the optical axis of the laser beam.

[0057] See also Figure 2 , Figure 5 The shell 4 is composed of an upper shell 41 and a lower shell 42. The upper shell 41 is provided with a DB9 power supply interface 71, a DB15 XY2-100 communication interface 72 and a 3D DA board 73; wherein, the external power supply system is connected to the 3DDA board 73 via the DB9 power supply structure, and is output to the drive motor 3 and the two-dimensional scanning module respectively after being processed. The communication signal of the host computer is connected to the 3D DA board 73 via the DB15XY2-100 communication interface 72, and is output to the drive motor 3 and the two-dimensional scanning module respectively after being processed.

[0058] See also Figure 2 , Figure 4 , Figures 10 to 12 The shell 4 has a light entrance hole and a light exit hole, wherein a coaxial plane window mirror 5 and a beam shaper 6 are arranged in the light entrance hole, and the beam shaper 6 is a black ceramic aperture. By replacing the black ceramic apertures with different apertures, the laser beam can be optimized, and the excess laser energy can be filtered and absorbed. The black ceramic aperture is made of a thermal conductive material, which can achieve a high temperature resistance effect and has the characteristics of small deformation. The plane window mirror 5 can prevent dust from entering the shell 4 through the light entrance hole of the shell 4, thereby ensuring the temperature and humidity inside the shell 4 and ensuring the stability of the working environment of the optical elements in the shell 4.

[0059] In addition, the utility model also provides a three-dimensional scanning system, which has embodiment 1 and embodiment 2:

[0060] Embodiment 1:

[0061] Figure 6 , Figure 7 , a three-dimensional scanning system, having the optical dynamic focusing module in any of the above-mentioned embodiments, further comprising a two-dimensional scanning module arranged on one side of the second off-axis parabolic mirror 102, the two-dimensional scanning module comprising at least a focusing structure and an X-axis galvanometer 81 and a Y-axis galvanometer 82; wherein the focusing structure is used to focus the laser beam refracted by the second off-axis parabolic mirror 102 or the Y-axis galvanometer 82 to form a focused laser beam, the X-axis galvanometer 81 and the Y-axis galvanometer 82 are used to receive the laser beam refracted by the second off-axis parabolic mirror 102 or the focused laser beam, and emit the laser beam or the focused laser beam vertically below the two-dimensional scanning module to present a micro-diffusion state, a collimated state or a micro-convergence state;

[0062] The focusing structure includes a focusing mirror 91 disposed between the X-axis galvanometer 81 and the second off-axis parabolic mirror 102 , and an aspheric window mirror 92 disposed below the X-axis galvanometer 81 and the Y-axis galvanometer 82 for optically processing the focused laser beam.

[0063] See also Figure 6 , Figure 7 The light entrance hole and the light exit hole of the shell 4 are perpendicular to each other, and the light exit hole is located below the X-axis galvanometer 81 and the Y-axis galvanometer 82. In addition, it should be noted that the two-dimensional scanning module and the focusing structure are both configured in the shell 4 to ensure that the shell 4 seals the entire optical element and ensures the stability of the optical element.

[0064] See also Figure 6 , Figure 7 The focusing mirror 91 is a meniscus lens, which can optimize and adjust the effective focal depth of the focused laser beam, and minimize spherical aberration and correct phase difference; the aspheric window mirror 92 can achieve optical functions such as correcting aberration, expanding imaging range, and improving optical resolution based on its special curved surface shape. When the focusing mirror 91 and the aspheric window mirror 92 are used in combination, the best optical processing effect can be obtained. Replacing the focusing mirror 91 with different optical specifications can obtain different dynamic zoom ranges and processing ranges; the focusing mirror 91 is configured on the housing 4 between the second off-axis parabolic mirror 102 and the X-axis galvanometer 81, and the aspheric window mirror 92 is configured at the light exit hole of the housing 4.

[0065] See also Figure 7 The X-axis galvanometer 81 is used to receive the focused laser beam refracted by the second off-axis parabolic mirror 102 and focused by the focusing mirror 91, and the Y-axis galvanometer 82 is used to refract the focused laser beam refracted by the X-axis galvanometer 81; the X-axis galvanometer 81 is driven by the X-axis galvanometer motor, and the Y-axis galvanometer 82 is driven by the Y-axis galvanometer motor; the adjustment of the optical path of the focused laser beam can be achieved by changing the angle of the X-axis galvanometer 81 by the X-axis galvanometer motor and changing the angle of the Y-axis galvanometer 82 by the Y-axis galvanometer motor.

[0066] During operation, the laser beam is incident into the housing 4 through the plane window mirror 5 and the beam shaper 6 in the light entrance hole, and then the laser beam is incident into the first off-axis parabolic mirror 101 and reflected toward the first reflector 103, and the first reflector 103 receives the laser beam and reflects it toward the second reflector 104, and the second reflector 104 then reflects the laser beam to the second off-axis parabolic mirror 102, and the second off-axis parabolic mirror 102 refracts the laser beam to the focusing mirror 91, and under the action of the focusing mirror 91, the laser beam is focused, and under the action of the X-axis galvanometer 81 and the Y-axis galvanometer 82, the focused beam passes through the aspheric window mirror 92 vertically downward and is emitted to the outside of the housing 4.

[0067] By driving the crank mirror holder 2 to rotate clockwise or counterclockwise by driving the motor 3, the focused laser beam in a slightly converged state emitted through the aspheric window mirror 92 can be in a positive defocus state relative to the focal plane (the focusing point is above the focal plane), the focused laser beam in a collimated state can be in a zero focus state (the focusing point coincides with the focal plane), and the focused laser beam in a slightly diffused state can be in a negative defocus state relative to the focal plane (the focusing point is below the focal plane); the non-mechanical transmission dynamic optical beam expander of the crank mirror holder 2 is driven by the driving motor 3, which effectively reduces the mechanical gap, increases the stability of the dynamic optical beam expander, and has the characteristics of high speed and high precision.

[0068] Embodiment 2:

[0069] The second embodiment and the first embodiment use the same or corresponding figure marks; the following only describes the differences between the second embodiment and the first embodiment.

[0070] See also Figures 1 to 4 , the difference between the second embodiment and the first embodiment is only that the focusing structure and the setting position of the focusing structure are different; in the second embodiment, the focusing structure is a field lens 93 arranged at the light exit hole of the shell 4. The laser beam refracted by the X-axis galvanometer 81 and the Y-axis galvanometer 82 is focused by the field lens 93 to achieve post-focusing of the laser beam. The focusing method of the laser beam in the first embodiment is front focusing, and the focusing method of the laser beam in the second embodiment is post-focusing. It should be noted that the references for the front focusing and the post-focusing are the X-axis galvanometer 81 and the Y-axis galvanometer 82. By changing the post-focusing method of the laser beam, the scope of application of the present application can be improved.

[0071] The above implementation modes are only for illustrating the technical concept and features of the utility model, and their purpose is to allow people familiar with this technology to understand the content of the utility model and implement it. It cannot be used to limit the protection scope of the utility model. Any equivalent changes or modifications made according to the spirit of the utility model should be included in the protection scope of the utility model.

Claims

1. An optical dynamic focusing module, characterized in that: An optical component is provided for changing the divergence angle on an off-axis laser beam optical path to achieve dynamic focusing, the optical component comprising at least: A first off-axis parabolic mirror and a second off-axis parabolic mirror are symmetrically arranged, wherein the off-axis parabola of the first off-axis parabolic mirror and the off-axis parabola of the second off-axis parabola are arranged opposite to each other; a first reflector and a second reflector, wherein the first reflector is used to receive the laser beam refracted by the first off-axis parabolic mirror and reflect the laser beam toward the second reflector, and the second reflector is capable of reflecting the received laser beam to the second off-axis parabolic mirror for secondary refraction; Wherein, the first reflector and the second reflector are configured to rotate synchronously so that: the center of the first reflector approaches or moves away from the focusing point of the first off-axis parabolic mirror, and then the laser beam reflected by the second reflector and refracted by the second off-axis parabolic mirror is in a slightly diffused state, a collimated state or a slightly focused state.

2. The optical dynamic focusing module according to claim 1, characterized in that: The first reflector and the second reflector are arranged on a crank mirror seat, and along a direction perpendicular to the crank mirror seat, the first reflector and the second reflector form a reflection inclination angle.

3. The optical dynamic focusing module according to claim 2, characterized in that: The crank mirror seat is driven by a driving motor to make the first reflecting mirror and the second reflecting mirror rotate synchronously.

4. The optical dynamic focusing module according to claim 1, characterized in that: The first reflector and / or the second reflector is made of silicon carbide.

5. The optical dynamic focusing module according to any one of claims 1 to 4, characterized in that: The optical component is arranged in the housing, and the laser beam is incident on the off-axis parabola of the first off-axis parabola mirror through the light entrance hole of the housing.

6. The optical dynamic focusing module according to claim 5, characterized in that: Along the optical path of the laser beam, a plane window mirror and a beam shaper are sequentially arranged in the light entrance hole, wherein the plane window mirror, the beam shaper and the light entrance hole are coaxially arranged.

7. The optical dynamic focusing module according to claim 5, characterized in that: The first off-axis parabolic mirror is arranged on the housing via a first adjustment seat, and the second off-axis parabolic mirror is arranged on the housing via a second adjustment seat.

8. A three-dimensional scanning system, characterized in that: It includes the optical dynamic focusing module described in any one of claims 1 to 7, and also includes a two-dimensional scanning module configured on one side of the second off-axis parabolic mirror, the two-dimensional scanning module at least includes a focusing structure and an X-axis galvanometer and a Y-axis galvanometer; wherein the focusing structure is used to focus the laser beam refracted by the second off-axis parabolic mirror or the Y-axis galvanometer to form a focused laser beam, and the X-axis galvanometer and the Y-axis galvanometer are used to receive the laser beam refracted by the second off-axis parabolic mirror or the focused laser beam, and vertically emit the laser beam or the focused laser beam below the two-dimensional scanning module to present a micro-diffusion state, a collimated state or a micro-convergence state.

9. The three-dimensional scanning system according to claim 8, characterized in that: The focusing structure includes a focusing mirror arranged between the X-axis galvanometer and the second off-axis parabolic mirror, and a non-planar window mirror arranged below the X-axis galvanometer and the Y-axis galvanometer for optically processing the focused laser beam.

10. The three-dimensional scanning system according to claim 8, characterized in that: The focusing structure includes a field mirror disposed below the X-axis galvanometer and the Y-axis galvanometer and used to focus the laser beam.

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