A two-dimensional laser scanning galvanometer device based on piezoelectric bimorph driving

Abstract

This invention discloses a two-dimensional laser scanning galvanometer device based on piezoelectric bicrystalline wafer driving, belonging to the field of piezoelectric driven scanning galvanometer technology. It includes a base with a circular hole on its side wall. A laser emitting device, partially penetrating the interior of the base, is installed through this hole. A first deflecting lens group is mounted on the side of the base. Below the first deflecting lens group, a second deflecting lens group is fixed to the base and perpendicular to it. A top cover is mounted on the top of the base. This invention, employing the aforementioned two-dimensional laser scanning galvanometer device based on piezoelectric bicrystalline wafer driving, solves the problems of dynamic performance contradictions, thermal drift, and reliability limitations inherent in existing electromagnetically driven scanning galvanometers. It fundamentally achieves high-bandwidth, low-heat-dissipation, and wear-free precision beam scanning. Furthermore, it is compact, portable, and low-cost, making it suitable for mass production and widespread civilian application.

Description

Technical Field

[0001] This invention relates to the field of piezoelectric driven scanning galvanometer technology, and in particular to a two-dimensional laser scanning galvanometer device based on piezoelectric dual-crystal drive. Background Technology

[0002] Two-dimensional laser scanning galvanometers are the core execution components of laser vector scanning technology. By controlling the high-speed deflection of two reflecting mirrors in a two-dimensional plane, they achieve precise programming control of the laser beam's trajectory. They are now widely used in laser marking, precision welding, micro-nano fabrication, additive manufacturing, lidar, and high-end scientific instruments. Their performance directly determines the speed, accuracy, and reliability of the entire laser processing or measurement system.

[0003] Currently, high-performance scanning galvanometers generally employ electromagnetic drive schemes. For example, patent CN212658893U discloses a two-dimensional laser scanning galvanometer optical path structure, which includes a galvanometer optical path support, an X-axis motor, and a Y-axis motor. A through-hole optical path cavity is located at the center of the support, containing X-axis and Y-axis galvanometers driven by their respective motors. Incident light is reflected by the X-axis galvanometer to the Y-axis galvanometer, and then reflected again by the Y-axis galvanometer for output, thus achieving two-dimensional scanning. While this technology is mature, its performance is limited by the electromagnetic drive principle and mechanical structure. In applications requiring higher speed, accuracy, and stability, it reveals the following inherent defects that are difficult to optimize in a coordinated manner: Dynamic performance contradiction: There is an inherent conflict between the system's high-speed response capability and static accuracy. Reducing the inertia of rotating components to increase speed weakens their mechanical stiffness, leading to response lag, overshoot, and oscillation during high-speed scanning, especially when the trajectory changes rapidly. This significantly reduces the effective working bandwidth and causes distortion of the processed graphic contour. In addition, the nonlinear gain difference and motion coupling between the X-axis and Y-axis drive units introduce errors that are difficult to fully compensate for using conventional linear control under high-speed and complex trajectories.

[0004] Thermal performance drift: Joule heating of the drive coil and frictional heat from bearings cause uneven thermal expansion of the mechanical structure, leading to micrometer-level shifts in the optical path, i.e., thermal drift. Simultaneously, the zero-point and sensitivity of integrated position sensors (such as capacitive sensors) change with temperature, further distorting the angle feedback signal. The combined effect of these two factors severely impairs the system's output stability and repeatability under prolonged continuous operation.

[0005] Mechanical reliability limitations: High-speed reciprocating oscillations relying on mechanical bearings inevitably suffer from long-term wear, affecting service life and introducing nonlinear interferences such as hysteresis errors. The inherent resonant frequency of the mechanical structure also limits the system's available dynamic bandwidth. To avoid the resonant point, compensation components or scanning frequency restrictions are often required in the control system, increasing the complexity of system design and calibration.

[0006] To alleviate the aforementioned problems, existing technologies mostly make localized improvements. For example, patent CN222748785U discloses a cooling system for a galvanometer, including water-cooled pipes and a semiconductor heat dissipation component. The semiconductor heat dissipation component includes a temperature control module and a cooling block, with a semiconductor cooling chip attached to the cooling block. The semiconductor cooling chip is connected to the water-cooled pipes via a connector to dissipate heat. Patent CN119200213A discloses a laser scanning galvanometer with a self-calibration system. Its core lies in a calibration structure integrated into a non-standard support within the inner cavity of the galvanometer body. This calibration structure uses a servo motor to drive a worm gear, which meshes with a worm wheel mounted on the output shaft of a high-speed motor, using the self-locking property of the worm gear to lock the angle of the galvanometer mirror. Simultaneously, another set of worm gear transmissions feeds the angle information back to an angle sensor, enabling real-time monitoring and deviation calculation, thereby automatically adjusting the motor output to complete the angle calibration. However, these solutions do not deviate from the basic framework of "electromagnetic drive + rotary bearing," often at the cost of increased system complexity, cost, and control difficulty, and cannot fundamentally overcome the aforementioned performance bottlenecks.

[0007] Therefore, the industry urgently needs a technological solution that innovates from the perspective of driving principles to simultaneously meet the requirements of high bandwidth, high precision, high stability and high reliability. Summary of the Invention

[0008] The purpose of this invention is to provide a two-dimensional laser scanning galvanometer device based on piezoelectric dual-crystal drive, which aims to solve the problems of dynamic performance contradictions, thermal drift and reliability limitations of existing electromagnetically driven scanning galvanometers, and fundamentally realize high bandwidth, low heat dissipation and wear-free precision beam scanning.

[0009] To achieve the above objectives, the present invention provides a two-dimensional laser scanning galvanometer device based on piezoelectric bicrystalline wafer driving, comprising a base, a circular hole on the side wall of the base, a laser emitting device partially inserted into the base through the circular hole, a first deflecting lens group mounted on the side of the base, a second deflecting lens group fixed to the base and perpendicular to the first deflecting lens group mounted below the first deflecting lens group, and a top cover plate mounted on the top of the base.

[0010] Preferably, the first deflecting lens group includes a first fixing device, a second fixing device, a first piezoelectric bicrystalline wafer, a first reflecting lens, and a second reflecting lens. The first fixing device and the second fixing device are fixed on the base. The outer end of the first piezoelectric bicrystalline wafer is pressed and fixed between the first fixing device and the second fixing device. The first reflecting lens and the second reflecting lens are respectively symmetrically attached to both sides of the inner end of the first piezoelectric bicrystalline wafer.

[0011] Preferably, the second deflecting lens group includes a third fixing device, a fourth fixing device, a second piezoelectric bicrystalline wafer, a third reflecting lens, and a fourth reflecting lens. The third fixing device and the fourth fixing device are fixed on the base. The outer end of the second piezoelectric bicrystalline wafer is pressed and fixed between the third fixing device and the fourth fixing device. The third reflecting lens and the fourth reflecting lens are symmetrically attached to both sides of the inner end of the second piezoelectric bicrystalline wafer. The second piezoelectric bicrystalline wafer and the first piezoelectric bicrystalline wafer are arranged perpendicular to each other.

[0012] Preferably, both the first and second piezoelectric bicrystalline wafers are integral piezoelectric bicrystalline wafers formed by bonding together two piezoelectric ceramic sheets of identical size and material in opposite polarization directions.

[0013] Preferably, the first deflecting lens group, the second deflecting lens group, and the top cover plate are fixed to the base by screws; the first reflecting lens and the second reflecting lens are attached to the first piezoelectric bicrystalline wafer by adhesive bonding, and the third reflecting lens and the fourth reflecting lens are attached to the second piezoelectric bicrystalline wafer by adhesive bonding; the laser emitting device is fixed to the base by at least one of interference fit, bolt connection, screw connection, and snap-fit ​​connection.

[0014] Preferably, in the first and second piezoelectric bicrystalline wafers, the two piezoelectric ceramic wafers of each wafer are grounded through a common electrode located in the middle, and connected to two electrodes of alternating current through the upper and lower surfaces located on the outer sides, respectively.

[0015] Preferably, the laser emitting device and the first deflecting lens group are arranged horizontally, and the second deflecting lens group is arranged vertically. After the laser is emitted from the laser emitting device, it is reflected by the first deflecting lens group and the second deflecting lens group, and finally emitted from the optical path channel on the base. The optical path propagates inside the base throughout the process from emission to emission.

[0016] Preferably, the assembly method of the device is as follows: S1. Fix the laser emitting device to the base; S2. The first and second reflective lenses are symmetrically fixed to both sides of the first piezoelectric bicrystalline wafer, and the third and fourth reflective lenses are symmetrically fixed to both sides of the second piezoelectric bicrystalline wafer. S3. Clamp the other end of the first piezoelectric bicrystalline wafer with the first fixing device and the second fixing device, and then fix the first fixing device and the second fixing device together; clamp the other end of the second piezoelectric bicrystalline wafer with the third fixing device and the fourth fixing device, and then fix the third fixing device and the fourth fixing device together. S4. Insert the first deflecting lens group into the pre-drilled square hole on the base that matches the first deflecting lens group. After the first deflecting lens group reaches the correct position, fix the first deflecting lens group to the base through the first fixing device and the second fixing device. Insert the second deflecting lens group into the pre-drilled square hole on the base that matches the second deflecting lens group. After the second deflecting lens group reaches the correct position, fix the second deflecting lens group to the base through the third fixing device and the fourth fixing device. S5. Power on the laser emitting device, the first deflecting lens group and the second deflecting lens group so that the first piezoelectric bicrystalline wafer and the second piezoelectric bicrystalline wafer reach their maximum deflection angles respectively. Observe whether the laser propagation path is normal. If it is not normal, repeat S2-S4 and adjust the positions of the first piezoelectric bicrystalline wafer and the second piezoelectric bicrystalline wafer until it is normal. If it is normal, fix the cover plate to the base and the assembly is complete.

[0017] Therefore, the beneficial effects of the above-mentioned two-dimensional laser scanning galvanometer device based on piezoelectric bicrystalline wafer driving are as follows: (1) The deflection lens group of the present invention can realize the adjustment of the angle of the reflective lens through the bending motion of the piezoelectric bicrystalline wafer with ultra-high response speed and simple structure. The two-dimensional laser scanning galvanometer device based on the piezoelectric bicrystalline wafer of the present invention can complete the scanning of the XY two-dimensional plane. Compared with the traditional mechanical swing mechanism, the piezoelectric bicrystalline wafer is extremely light and has no mechanical friction with other parts. Compared with the traditional electromagnetic scanning galvanometer, the piezoelectric driven two-dimensional scanning galvanometer has the advantages of low component inertia, no thermal drift caused by mechanical friction, and no wear problem caused by mechanical friction.

[0018] (2) The piezoelectric bicrystalline silicon used to drive the deflection of the reflector in this invention has the advantage of resisting electromagnetic interference compared with traditional motor drive, and can be used in extreme working conditions with electromagnetic interference.

[0019] (3) The laser emitting device, the first deflecting lens group and the second deflecting lens group in this invention are integrated on the same base, and the price of the piezoelectric double crystal is very low, while the electromagnetically driven deflecting mirror requires a lot of space for the drive motor. Therefore, compared with electromagnetic drive, this invention is small, exquisite, easy to carry, and low in cost, making it suitable for mass production and popular application in the public.

[0020] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overall structure of an embodiment of a two-dimensional laser scanning galvanometer device based on piezoelectric dual-crystal drive according to the present invention; Figure 2This is an internal structure and optical path propagation diagram of an embodiment of the present invention; Figure 3 This is a schematic diagram of the power supply principle when the voltage on the upper side of the piezoelectric bicrystalline wafer is higher than the voltage on the lower side in an embodiment of the present invention; Figure 4 This is a schematic diagram of the power-on principle when the voltage on the lower side of the piezoelectric bicrystalline wafer is higher than the voltage on the upper side in an embodiment of the present invention; Figure 5 This is a schematic diagram of the deflection of the reflective lens in an embodiment of the present invention.

[0022] Figure Labels 1. Top cover plate; 2. First deflecting lens group; 3. Laser emitting device; 4. Base; 5. Second deflecting lens group; 21. First fixing device; 22. Second fixing device; 23. First piezoelectric bicrystalline wafer; 24. First reflecting lens; 25. Second reflecting lens; 51. Third reflecting lens; 52. Second piezoelectric bicrystalline wafer; 53. Fourth reflecting lens; 54. Third fixing device; 55. Fourth fixing device. Detailed Implementation

[0023] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0024] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "first," "second," and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0025] Example 1: like Figure 1 As shown, this embodiment provides a two-dimensional laser scanning galvanometer device based on piezoelectric dual-crystal drive, mainly composed of an upper cover plate 1, a first deflecting lens group 2, a laser emitting device 3, a base 4, and a second deflecting lens group 5. The base 4 serves as the main support structure of the device, providing mounting positions for other components and ensuring smooth light transmission.

[0026] A circular hole is provided on the side wall of the base 4. The laser emitting device 3 passes through the circular hole and is fixedly connected to the base 4. A part of the laser emitting device 3 is located inside the base 4, and a part is located outside the base 4. The laser emitting device 3 can be fixed to the base 4 by at least one of the following methods: interference fit, bolt connection, screw connection, and snap-fit ​​connection.

[0027] A first deflecting lens assembly 2 is mounted on the side of the base 4 and is fixedly connected to the base 4 by fixing parts. The first deflecting lens assembly 2 consists of a first fixing device 21, a second fixing device 22, a first piezoelectric bicrystalline wafer 23, a first reflecting lens 24, and a second reflecting lens 25. The first fixing device 21 and the second fixing device 22 are fixed to the base 4. The outer end of the first piezoelectric bicrystalline wafer 23 is pressed and fixed between the first fixing device 21 and the second fixing device 22. When the first fixing device 21 and the second fixing device 22 are connected, the width of the internal gap should be slightly smaller than the thickness of the first piezoelectric bicrystalline wafer 23 to clamp it tightly. The first reflecting lens 24 and the second reflecting lens 25 are symmetrically fixed to both sides of the inner end of the first piezoelectric bicrystalline wafer 23 by adhesive bonding. The second piezoelectric bicrystalline wafer 52 is arranged perpendicularly to the first piezoelectric bicrystalline wafer 23 to facilitate adjustment of the optical path in two-dimensional space.

[0028] A second deflecting lens group 5 is installed at the bottom of the base 4. The second deflecting lens group 5 is arranged perpendicularly to the first deflecting lens group 2. The second deflecting lens group 5 consists of a third fixing device 54, a fourth fixing device 55, a second piezoelectric bicrystalline wafer 52, a third reflecting lens 51, and a fourth reflecting lens 53. The third fixing device 54 and the fourth fixing device 55 are fixed to the base 4. The outer end of the second piezoelectric bicrystalline wafer 52 is pressed and fixed between the third fixing device 54 and the fourth fixing device 55. When the third fixing device 54 and the fourth fixing device 55 are connected, the width of their internal gap should be slightly smaller than the thickness of the second piezoelectric bicrystalline wafer 52 to clamp it securely. The third reflecting lens 51 and the fourth reflecting lens 53 are symmetrically fixed to both sides of the inner end of the second piezoelectric bicrystalline wafer 52 by adhesive bonding.

[0029] like Figure 2 As shown, the laser emitting device 3 and the first deflecting lens group 2 are arranged horizontally, while the second deflecting lens group 5 is arranged vertically. After the laser is emitted from the laser emitting device 3, it travels a certain distance inside the base 4 before illuminating the first reflecting lens 24. After being reflected by the first reflecting lens 24, the laser continues to travel a certain distance inside the base 4 before illuminating the fourth reflecting lens 53. After being reflected by the fourth reflecting lens 53, it travels a certain distance inside the base 4 before exiting from the optical path channel of the base 4 and finally illuminating the target object. This process principle can be applied to fields such as optical marking, precision welding, micro-nano fabrication, additive manufacturing, and lidar.

[0030] The first piezoelectric bicrystalline wafer 23 and the second piezoelectric bicrystalline wafer 52 are both integral piezoelectric bicrystalline wafers composed of two piezoelectric ceramic sheets of identical size and material bonded together with opposite polarization directions. When connected in parallel, the common electrode in the middle of the two piezoelectric ceramic sheets is grounded, and the top and bottom surfaces of the piezoelectric bicrystalline wafer are connected to the two poles of an alternating current, such as... Figure 3 As shown, when the voltage on the upper side of the piezoelectric bicrystalline wafer is higher than the voltage on the lower side, the polarization direction of the upper piezoelectric ceramic sheet is the same as the direction of the electric field, its thickness increases, and its length decreases. Conversely, the polarization direction of the lower piezoelectric ceramic sheet is opposite to the direction of the electric field, its thickness decreases, and its length increases. The upper part becomes shorter and the lower part longer, causing the entire piezoelectric bicrystalline wafer structure to bend towards the shortened side (the upper side). Similarly, since alternating current is applied, when the voltages on the upper and lower sides of the piezoelectric bicrystalline wafer are reversed, as... Figure 4 As shown, the upper piezoelectric ceramic sheet becomes longer, the lower piezoelectric ceramic sheet becomes shorter, and the piezoelectric bicrystalline wafer bends downward. By adjusting the power supply frequency, the reciprocating bending speed of the piezoelectric bicrystalline wafer can be adjusted, thereby adjusting the scanning speed. The first reflecting mirror group 2 and the second reflecting mirror group 5 are powered independently, so the voltage and frequency of the mirror groups can be controlled independently, thereby controlling the laser scanning frequency and scanning path, and completing the basic function of two-dimensional scanning deflection mirror for two-dimensional scanning.

[0031] like Figure 5 As shown, the left side of the first piezoelectric bicrystalline wafer 23 is fixed to the base 4 by the first fixing mechanism 21 and the second fixing mechanism 22, thus preventing it from oscillating. The right side is symmetrically fixed with the first reflecting mirror 24 and the second reflecting mirror 25. When alternating current is applied to the first piezoelectric bicrystalline wafer 23, it drives the first reflecting mirror 24 and the second reflecting mirror 25 to oscillate back and forth. This causes a change in the angle of the first reflecting mirror 24 and the second reflecting mirror 25 relative to the laser beam, thereby changing the laser beam path. Since the first piezoelectric bicrystalline wafer 23 oscillates back and forth in the X-plane, the beam path is also deflected in the X-plane. Figure 2 As can be seen, the second deflecting lens group 5 is arranged in the vertical direction, so the second piezoelectric bicrystalline wafer 52 oscillates back and forth in the Y plane, thus the optical path is deflected in the Y plane. After the optical path is deflected by the X plane and the Y plane, it can complete the two-dimensional scanning function.

[0032] The assembly method of the above-mentioned device is as follows: S1. Fix the laser emitting device 3 to the base 4. The base 4 has a round hole that matches the shape of the laser emitting device 3 in advance so that the laser emitting device can be accurately positioned and installed on the base 4.

[0033] S2. The first reflecting lens 24 and the second reflecting lens 25 are symmetrically fixed to both sides of the first piezoelectric bicrystalline wafer 23, and the third reflecting lens 51 and the fourth reflecting lens 53 are symmetrically fixed to both sides of the second piezoelectric bicrystalline wafer 52.

[0034] S3. Clamp the other end of the first piezoelectric bicrystalline wafer 23 with the first fixing device 21 and the second fixing device 22, then fix the first fixing device and the second fixing device together. Clamp the other end of the second piezoelectric bicrystalline wafer 52 with the third fixing device 54 and the fourth fixing device 55, then fix the third fixing device 54 and the fourth fixing device 55 together.

[0035] S4. Insert the first deflecting lens group 2 into the pre-drilled square hole in the base 4. The shape of the square hole matches the shape of the first deflecting lens group 2 so that the first deflecting lens group 2 can be positioned on the base 4. After the first deflecting lens group 2 reaches the correct position, fix the first deflecting lens group 2 to the base 4 using the first fixing device 21 and the second fixing device 22. Next, insert the second deflecting lens group 2 into the pre-drilled square hole in the base 4. The shape of the square hole matches the shape of the second deflecting lens group 5 so that the second deflecting lens group 5 can be positioned on the base 4. After the second deflecting lens group 5 reaches the correct position, fix the second deflecting lens group 5 to the base 4 using the third fixing device 21 and the fourth fixing device 22.

[0036] S5. Power on the laser emitting device 3, the first deflecting lens group 2, and the second deflecting lens group 5 so that the first piezoelectric bicrystalline wafer 23 and the second piezoelectric bicrystalline wafer 52 reach their maximum deflection angles respectively. Observe whether the laser propagation path is normal. If it is not normal, repeat S2-S4 and adjust the positions of the first piezoelectric bicrystalline wafer 23 and the second piezoelectric bicrystalline wafer 52 until they are normal. If it is normal, fix the upper cover plate to the base and the assembly is complete.

[0037] Therefore, the present invention adopts the above-mentioned two-dimensional laser scanning galvanometer device based on piezoelectric dual crystal drive, which solves the problems of dynamic performance contradiction, thermal drift and reliability limitation of existing electromagnetic drive scanning galvanometers. It fundamentally realizes high bandwidth, low heat dissipation and wear-free precision beam scanning, and has the characteristics of being small and exquisite, easy to carry and low cost, making it suitable for mass production and popular application.

[0038] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A two-dimensional laser scanning galvanometer device based on piezoelectric bicrystalline wafer driving, characterized in that: The device includes a base, a circular hole on the side wall of the base, a laser emitting device that partially enters the interior of the base is installed in the circular hole, a first deflecting lens group is installed on the side of the base, a second deflecting lens group is installed below the first deflecting lens group and fixed on the base and perpendicular to the first deflecting lens group, and a top cover plate is installed on the top of the base.

2. The two-dimensional laser scanning galvanometer device based on piezoelectric bicrystalline wafer driving according to claim 1, characterized in that: The first deflecting lens group includes a first fixing device, a second fixing device, a first piezoelectric bicrystalline wafer, a first reflecting lens, and a second reflecting lens. The first fixing device and the second fixing device are fixed on the base. The outer end of the first piezoelectric bicrystalline wafer is pressed and fixed between the first fixing device and the second fixing device. The first reflecting lens and the second reflecting lens are respectively symmetrically attached to both sides of the inner end of the first piezoelectric bicrystalline wafer.

3. The two-dimensional laser scanning galvanometer device based on piezoelectric bicrystalline wafer driving according to claim 2, characterized in that: The second deflecting lens group includes a third fixing device, a fourth fixing device, a second piezoelectric bicrystalline wafer, a third reflecting lens, and a fourth reflecting lens. The third fixing device and the fourth fixing device are fixed on the base. The outer end of the second piezoelectric bicrystalline wafer is pressed and fixed between the third fixing device and the fourth fixing device. The third reflecting lens and the fourth reflecting lens are symmetrically attached to both sides of the inner end of the second piezoelectric bicrystalline wafer. The second piezoelectric bicrystalline wafer and the first piezoelectric bicrystalline wafer are arranged perpendicular to each other.

4. The two-dimensional laser scanning galvanometer device based on piezoelectric bicrystalline wafer driving according to claim 3, characterized in that: Both the first and second piezoelectric bicrystalline wafers are integral piezoelectric bicrystalline wafers composed of two piezoelectric ceramic sheets of identical size and material bonded together in opposite polarization directions.

5. The two-dimensional laser scanning galvanometer device based on piezoelectric bicrystalline wafer driving according to claim 4, characterized in that: The first deflecting lens group, the second deflecting lens group, and the top cover plate are fixed to the base by screws; the first reflecting lens and the second reflecting lens are attached to the first piezoelectric bicrystalline wafer by adhesive bonding, and the third reflecting lens and the fourth reflecting lens are attached to the second piezoelectric bicrystalline wafer by adhesive bonding; the laser emitting device is fixed to the base by at least one of the following methods: interference fit, bolt connection, screw connection, and snap-fit ​​connection.

6. The two-dimensional laser scanning galvanometer device based on piezoelectric bicrystalline wafer driving according to claim 4, characterized in that: In the first and second piezoelectric bicrystalline wafers, each of the two piezoelectric ceramic wafers is grounded through a common electrode located in the middle, and connected to two electrodes of alternating current through the upper and lower surfaces located on the outside.

7. A two-dimensional laser scanning galvanometer device based on piezoelectric bicrystalline wafer driving according to claim 4, characterized in that: The laser emitting device and the first deflecting lens group are arranged horizontally, and the second deflecting lens group is arranged vertically. After the laser is emitted from the laser emitting device, it is reflected by the first deflecting lens group and the second deflecting lens group, and finally emitted from the optical path channel on the base. The optical path propagates inside the base throughout the process from emission to emission.

8. The two-dimensional laser scanning galvanometer device based on piezoelectric bicrystalline wafer driving according to claim 4, characterized in that, The assembly method of the device is as follows: S1. Fix the laser emitting device to the base; S2. The first and second reflective lenses are symmetrically fixed to both sides of the first piezoelectric bicrystalline wafer, and the third and fourth reflective lenses are symmetrically fixed to both sides of the second piezoelectric bicrystalline wafer. S3. Clamp the other end of the first piezoelectric bicrystalline wafer with the first fixing device and the second fixing device, and then fix the first fixing device and the second fixing device together; clamp the other end of the second piezoelectric bicrystalline wafer with the third fixing device and the fourth fixing device, and then fix the third fixing device and the fourth fixing device together. S4. Insert the first deflecting lens group into the pre-drilled square hole on the base that matches the first deflecting lens group. After the first deflecting lens group reaches the correct position, fix the first deflecting lens group to the base through the first fixing device and the second fixing device. Insert the second deflecting lens group into the pre-drilled square hole on the base that matches the second deflecting lens group. After the second deflecting lens group reaches the correct position, fix the second deflecting lens group to the base through the third fixing device and the fourth fixing device. S5. Power on the laser emitting device, the first deflecting lens group and the second deflecting lens group so that the first piezoelectric bicrystalline wafer and the second piezoelectric bicrystalline wafer reach the maximum deflection angle respectively. Observe whether the laser propagation path is normal. If it is not normal, repeat S2-S4 and adjust the position of the first piezoelectric bicrystalline wafer and the second piezoelectric bicrystalline wafer until it is normal. If everything is normal, then fix the cover plate to the base as described above, and the assembly is complete.

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