Two-dimensional scanning galvanometer device

Abstract

The invention discloses a two-dimensional scanning galvanometer device, which is characterized by comprising a first magnet, a second magnet, a magnetic conductive yoke part, a galvanometer chip, a base, a cover plate and a flexible circuit board, the first magnet is an annular permanent magnet and is arranged above the magnetic conductive yoke part; the second magnet is a permanent magnet and is arranged above the magnetic conductive yoke part; the magnetic conductive yoke part is used for supporting the first magnet and the second magnet; the galvanometer chip is arranged above the first magnet; the first magnet, the second magnet, the magnetic conductive yoke part and the galvanometer chip are all located in the base; the cover plate is connected with the base and is arranged above the base; the flexible circuit board is connected with the galvanometer chip. The magnetic field system is simple in structure, high magnetic field intensity is generated through the two permanent magnets, additional permanent magnets do not need to be added, the overall size and weight of the device are reduced, and the material cost is reduced.

Description

Technical Field

[0001] This application relates to the field of lidar technology, and in particular to a two-dimensional scanning galvanometer device and a lidar. Background Technology

[0002] Micro-Electro-Mechanical System (MEMS) two-dimensional scanning galvanometers are important optical scanning devices with advantages such as fast response speed, high scanning accuracy, mass production capability, and low cost, and are widely used in the field of lidar.

[0003] Existing MEMS two-dimensional scanning galvanometers commonly employ either moving coils or moving permanent magnets. In related technologies, to enhance the electromagnetic force driving the galvanometer's motion, the number of permanent magnets or magnetic conductive sheets is typically increased. This results in a complex structure for the two-dimensional scanning galvanometer device, making assembly difficult, increasing its overall size, and incurring high material and manufacturing costs. Summary of the Invention

[0004] To address or partially address the problems existing in related technologies, this application provides a two-dimensional galvanometer scanning device that generates a strong magnetic field through two permanent magnets. The magnetic field system of this application has a simple structure, is easy to assemble, reduces the overall size of the two-dimensional galvanometer scanning device, and lowers material and processing costs.

[0005] This application provides a two-dimensional galvanometer scanning device, including a first magnet, a second magnet, a magnetic yoke, a galvanometer chip, a base, a cover plate, and a flexible circuit board.

[0006] The first magnet is a ring-shaped permanent magnet, positioned above the magnetically conductive yoke; the second magnet is also a permanent magnet, positioned above the magnetically conductive yoke; the magnetically conductive yoke supports the first and second magnets; the galvanometer chip is positioned above the first magnet; the first magnet, the second magnet, the magnetically conductive yoke, and the galvanometer chip are all located inside the base; a cover plate is connected to the base and positioned above it; a flexible circuit board is connected to the galvanometer chip. The magnetic field system is simple in structure, generating a strong magnetic field through just two permanent magnets, eliminating the need for additional permanent magnets or magnetically conductive sheets, thus reducing material and processing costs, and simultaneously decreasing the overall size and weight of the two-dimensional scanning galvanometer device.

[0007] In some embodiments, the outer and inner contours of the first magnet are both rounded rectangles, and its surface is used for positioning and supporting the galvanometer chip. The first magnet is manufactured as a single piece, thus reducing errors introduced by multiple processing and assembly steps, resulting in a high degree of flatness on its surface. Using the surface of the first magnet for positioning the galvanometer chip improves the assembly accuracy of the galvanometer chip, reduces the offset of optical components, and thereby improves the quality and performance of the two-dimensional scanning galvanometer device.

[0008] In some embodiments, a second magnet is disposed within a rounded rectangular through-hole of the first magnet. The first and second magnets generate a magnetic field that causes the galvanometer chip to move.

[0009] In some embodiments, the magnetic yoke is made of a high-permeability material, and the first and second magnets are fixed to the yoke by adhesive bonding within grooves. The magnetic yoke guides and concentrates the magnetic field generated by the first and second magnets, reducing magnetic field loss. During production, the first and second magnets can be quickly and accurately positioned on the magnetic yoke via the grooves. Adhesive bonding effectively fixes the permanent magnets in a short time, is convenient to use, and allows for mass production. Furthermore, the adhesive has good durability and corrosion resistance, can withstand various environmental conditions, protects the magnetic yoke and permanent magnets from environmental factors, and ensures the stability and reliability of the device.

[0010] In some embodiments, the base is a housing with an internal cavity for supporting the magnetic yoke and the first magnet; wherein the first magnet, the second magnet, the magnetic yoke, and the galvanometer chip are all located within the cavity of the base.

[0011] In some embodiments, the galvanometer chip includes a movable coil frame, a base, a reflector, a first torsion axis, and a second torsion axis. The outer contour of the movable coil frame is connected to the base via the second torsion axis, and the inner contour of the movable coil frame is connected to the reflector via the first torsion axis. Vertically, the first torsion axis is located on both sides of the reflector; horizontally, the second torsion axis is located on both sides of the movable coil frame. When the movable coil frame moves simultaneously around the first and second torsion axes, it can drive the reflector to also move around the first and second torsion axes, thereby achieving two-dimensional field-of-view scanning.

[0012] In some embodiments, the movable coil frame has multiple turns of metal conductive coils disposed above the rounded rectangular through-hole area in the middle of the first magnet.

[0013] In some embodiments, a cover plate is disposed above the galvanometer chip and is fixedly connected to the base; the cover plate also includes a window with beveled sidewalls. The fixed connection between the cover plate and the base protects the device within the base, thereby improving the lifespan of the two-dimensional scanning galvanometer device.

[0014] In some embodiments, one end of the flexible circuit board is connected to the galvanometer chip, and the other end is connected to an external power source to energize the conductive coils on the movable coil frame.

[0015] In some embodiments, the first and second magnets employ multi-pole magnetization; the magnetization direction of both the first and second magnets is along the thickness direction of the permanent magnet, and the magnetic domain direction of the permanent magnet is parallel to the magnetization direction. The use of multi-pole magnetization for both the first and second magnets ensures the uniformity and stability of magnetization, while also improving production efficiency. During the magnetization process, the parallelism between the magnetic domain direction and the magnetization direction avoids performance degradation caused by inconsistencies between the domain direction and the magnetization direction.

[0016] The technical solution provided in this application has the following beneficial effects:

[0017] This invention discloses a two-dimensional scanning galvanometer device. The magnetic field system of this device is simple in structure, requiring only a first magnet, a second magnet, and a magnetically conductive yoke to provide a strong magnetic field intensity. No additional permanent magnets are needed, reducing material costs and the overall size and weight of the two-dimensional scanning galvanometer device. The annular first magnet is integrally machined, resulting in a high surface flatness. It can serve as a positioning surface for the galvanometer chip and support the chip, improving the assembly accuracy of the chip and reducing the offset of optical components. Furthermore, since the magnetic field generated by the intermediate second magnet is utilized, the required magnetic induction intensity can be achieved without adding an additional magnetically conductive sheet, further reducing manufacturing costs. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the structure of a two-dimensional scanning galvanometer device in a comparative embodiment;

[0020] Figure 2 This is a schematic diagram of the magnetic field lines generated by the magnetic field system of a two-dimensional scanning galvanometer device in a comparative embodiment.

[0021] Figure 3 This is an exploded structural diagram of a two-dimensional scanning galvanometer device in one embodiment of this application;

[0022] Figure 4 This is a schematic diagram of the galvanometer chip structure in a two-dimensional scanning galvanometer device according to one embodiment of this application;

[0023] Figure 5 This is a front view and a cross-sectional view of a two-dimensional scanning galvanometer device in one embodiment of this application;

[0024] Figure 6 This is a schematic diagram of the structure of the cover plate in a two-dimensional scanning galvanometer device according to one embodiment of this application;

[0025] Figure 7 This is a schematic diagram showing the position of the two-dimensional scanning galvanometer device inside a solid-state lidar in one embodiment of this application;

[0026] Figure 8 This is a schematic diagram of the structure of the window on the cover plate in a two-dimensional scanning galvanometer device according to one embodiment of this application;

[0027] Figure 9 This is a schematic diagram of a magnetization method for the first magnet and the second magnet in one embodiment of this application;

[0028] Figure 10 This is a schematic diagram of the magnetic field lines generated by the magnetic field system of the two-dimensional scanning galvanometer device in one embodiment of this application. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the embodiments described herein are merely some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0031] like Figure 1 As shown, in one example, the two-dimensional scanning galvanometer device 12 employing a moving coil structure includes a permanent magnet 121, a permanent magnet 122, a movable conductive coil frame 123, a magnetically conductive yoke 124, an intermediate magnetically conductive part 125, and a magnetically conductive sheet 126. The permanent magnet 121, permanent magnet 122, magnetically conductive yoke 124, and intermediate magnetically conductive part 125 constitute the magnetic field system of the two-dimensional scanning galvanometer device 12.

[0032] In one example, both permanent magnets 121 and 122 are L-shaped permanent magnets. Both L-shaped permanent magnets are disposed on the surface of the magnetic yoke 124 and supported by it. Specifically, in the vertical direction, the upper surface of permanent magnet 121 is the S pole and the lower surface is the N pole; the upper surface of permanent magnet 122 is the N pole and the lower surface is the S pole. Furthermore, permanent magnets 121 and 122 are located below the movable conductive coil frame 123, providing a magnetic field that moves the movable conductive coil frame 123. The movable conductive coil frame 123 is disposed on the two-dimensional scanning galvanometer chip. In one example, after the two L-shaped permanent magnets are assembled, their upper surfaces serve as the positioning surface of the two-dimensional scanning galvanometer chip. Because there is a height difference between the upper surfaces of the two L-shaped permanent magnets, the two-dimensional scanning galvanometer chip will experience additional stress and mirror misalignment, thus affecting the working performance of the lidar.

[0033] In one example, the magnetic yoke 124 is made of a high-permeability material to guide and concentrate the magnetic field generated by permanent magnets 121 and 122, reducing magnetic field loss. The intermediate magnetic yoke 125 is located below the movable conductive coil frame 123 and between the permanent magnets 121 and 122, and is fixed to the upper surface of the magnetic yoke 124. Specifically, when viewed from above, the movable conductive coil frame 123 has an inner and outer contour, and the intermediate magnetic yoke 125 is entirely within the inner contour of the movable conductive coil frame 123. In one example, the magnetic yoke 124 is made of a high-permeability material and is elliptical in shape to provide a low magnetic reluctance path for the magnetic field. Therefore, the magnetic field of the movable conductive coil frame 123 tends to enter and leave the intermediate magnetic conductive part 125 at an angle closer to 90 degrees. In other words, under the action of the intermediate magnetic conductive part 125, the magnetic field around the movable conductive coil frame 123 is enhanced, thereby providing a greater driving torque to the movable conductive coil frame 123.

[0034] In one example, to maintain the required magnetic induction intensity, a magnetic guide plate 126 is typically added to the upper surface of the L-shaped permanent magnet. The magnetic guide plate 126 is also made of a high-permeability material, providing a low magnetic reluctance path for the magnetic field, guiding and focusing the magnetic field around the movable conductive coil frame 123 to achieve the required magnetic field strength. Due to the high precision requirements for the processing of the magnetic guide plate 126, and the slightly complex shape of the intermediate magnetic guide portion 125, the manufacturing cost is relatively high. Furthermore, the magnetic field system in the two-dimensional scanning galvanometer device 12 in the above example is complex. In addition to the two L-shaped permanent magnets, the intermediate magnetic guide portion 125 and the magnetic guide plate 126 are also required to maintain the required magnetic induction intensity, resulting in a higher overall material cost. The complex magnetic field system in the above comparative embodiment also leads to a complex overall structure of the two-dimensional scanning galvanometer device 12, making assembly difficult, and resulting in a larger overall size and weight.

[0035] In one exampleFigure 1 The magnetic field lines generated by the magnetic field system shown are as follows: Figure 2 As shown, the magnetic field system composed of permanent magnet 121, permanent magnet 122, magnetically conductive yoke 124, and intermediate magnetically conductive part 125 generates a relatively uniform distribution of magnetic field lines. Under the action of the intermediate magnetically conductive part 125, more magnetic field lines are gathered around the movable coil frame 123, increasing the magnetic induction intensity around the movable coil frame 123, thereby generating a larger driving torque. The magnetically conductive yoke 124, located below the two L-shaped permanent magnets, guides and gathers the magnetic field lines of the two L-shaped permanent magnets, helping to "close" the path of the magnetic field lines and reduce magnetic field loss.

[0036] like Figure 3 As shown in the figure, this application provides a two-dimensional scanning galvanometer device 11, including a first magnet 111, a second magnet 112, a magnetic yoke 113, a galvanometer chip 114, a base 115, a cover plate 116, and a flexible circuit board 117. The first magnet 111, the second magnet 112, the magnetic yoke 113, and the galvanometer chip 114 are all disposed inside the base 115, and the cover plate 116 is disposed above the base 115. The flexible circuit board 117 is connected to the galvanometer chip 114 and is disposed outside the base 115.

[0037] The first magnet 111, the second magnet 112, and the magnetic yoke 113 together form a magnetic field system that moves the galvanometer chip 114, which is positioned above the magnetic field system. Specifically, the galvanometer chip is located on the upper surface of the first magnet 111 and is used to achieve two-dimensional field-of-view scanning of the lidar.

[0038] In one embodiment, the first magnet 111 is a ring-shaped permanent magnet with rounded rectangles for both its outer and inner contours, and is positioned above the magnetic yoke 113. Specifically, the through-hole located at the geometric center of the first magnet 111 is a rounded rectangle, used to accommodate the second magnet 112 and provide space for the movement of the galvanometer chip 114.

[0039] The second magnet 112 is a permanent magnet, disposed above the magnetically conductive yoke 113, and located within a rounded rectangular through-hole at the geometric center of the annular first magnet 111. In one specific embodiment, the second magnet 112 can be a cuboid, cube, cylinder, or other structures. In one specific embodiment, the first magnet 111 is made of a permanent magnet material, and the second magnet 112 can be made of a permanent magnet material or a high-permeability material. In this embodiment, both the first magnet 111 and the second magnet 112 are made of permanent magnet materials to increase the magnetic field strength and improve the driving torque.

[0040] The magnetic yoke 113 is made of a high-permeability material and is used to guide and concentrate the magnetic field generated by the first magnet 111 and the second magnet 112 to the desired position, which helps to reduce magnetic path loss and enhance magnetic field strength. In a specific embodiment, the material of the magnetic yoke 113 can be various high-permeability materials, such as silicon steel sheets and ferrites; the shape of the magnetic yoke 113 can be a cuboid, cube, cylinder, or other structures.

[0041] The two-dimensional scanning galvanometer device 11 provided in this application embodiment has a simple magnetic field system. The first magnet 111, the second magnet 112, and the magnetic yoke 113 can provide strong magnetic induction intensity, are easy to assemble, reduce the overall size of the two-dimensional galvanometer scanning device, and lower material costs. In addition, the first magnet 111 and the second magnet 112 have simple shapes, are easy to process, and can be integrally formed, reducing processing costs.

[0042] In one specific embodiment, the annular first magnet 111 is integrally machined, resulting in a high surface flatness. Furthermore, the upper surface of the first magnet 111 can be used as a positioning surface for the galvanometer chip 114, serving as an assembly reference for the galvanometer chip 114. This can improve the assembly accuracy of the galvanometer chip 114 and reduce the offset of the optical components within the galvanometer chip 114.

[0043] like Figure 4 As shown, the galvanometer chip 114 includes a base 1141, a movable coil frame 1142, a reflector 1143, a first torsion shaft 1144, and a second torsion shaft 1145. The base 1141 is connected to the movable coil frame 1142 via the second torsion shaft 1145, and the movable coil frame 1142 is connected to the reflector 1143 via the first torsion shaft 1144. Specifically, in the vertical direction, the first torsion shaft 1144 is disposed on both sides of the reflector 1143; in the horizontal direction, the second torsion shaft 1145 is disposed on both sides of the outer contour of the movable coil frame 1142. In a specific embodiment, the first torsion shaft 1144 is perpendicular to the second torsion shaft 1145.

[0044] The movable coil frame 1142 has multiple turns of conductive metal coils and is positioned above the annular first magnet 111. Specifically, the movable coil frame 1142 is positioned directly above the rounded rectangular through-hole area in the middle of the annular first magnet 111, meaning that the projection of the movable coil frame 1142 onto the surface of the first magnet 111 is completely within the rounded rectangular through-hole. Viewed from above, the outer contour of the movable coil frame 1142 is within the contour of the rounded rectangular through-hole in the middle of the annular first magnet 111. The second magnet 112 is positioned directly below the movable coil frame 1142, meaning that the projection of the second magnet 112 onto the surface of the galvanometer chip 114 is completely within the outer contour of the movable coil frame 1142.

[0045] In one specific embodiment, a flexible circuit board 117 is disposed on one side of the galvanometer chip 114, with one end connected to the galvanometer chip 114 via a wire. The other end of the flexible circuit board 117 is connected to an external power source, thereby energizing the conductive coil in the movable coil frame 1142.

[0046] Specifically, when the conductive coil in the movable coil frame 1142 is energized, the coil experiences an Ampere force in the magnetic field B as current flows through it, generating a torque that causes the movable coil frame 1142 to deflect. Since the inner contour of the movable coil frame 1142 is connected to the first torsion axis 1144 and the outer contour is connected to the second torsion axis 1145, under the action of the Ampere force, the movable coil frame 1142 can simultaneously undergo torsional motion around both the first and second torsion axes 1144 and 1145. In the above embodiment, since the reflector 1143 is connected to the movable coil frame 1142 via the first torsion axis 1144, the reflector 1143, influenced by the movement of the movable coil frame 1142, will also simultaneously vibrate around both the first and second torsion axes 1144 and 1145, thereby achieving a two-dimensional field of view scan.

[0047] like Figure 5 As shown, the cover plate 116 is connected to the base 115 to protect the internal first magnet 111, second magnet 112, magnetic yoke 113 and galvanometer chip 114, reduce their damage probability, and enable the two-dimensional scanning galvanometer device 11 to have a longer lifespan, thereby enabling the lidar to have a longer service life.

[0048] The base 115 includes a first magnet 111, a second magnet 112, a magnetic yoke 113, and a galvanometer chip 114. Specifically, the magnetic yoke 113 is located below the first magnet 111 and the second magnet 112 to support them. The first magnet 111 is located below the galvanometer chip 114 to support and fix it.

[0049] Furthermore, the second magnet 112 is bonded to the upper surface of the magnetic yoke 113 by adhesive within the groove 1131 in the middle of the magnetic yoke 113. The second magnet 112 completely covers the groove 1131 in the middle of the magnetic yoke 113, and from a top-down view, the outline of the groove in the middle of the magnetic yoke 113 is completely within the outline of the second magnet 112. After the second magnet 112 is bonded to the upper surface of the magnetic yoke 113, the first magnet 111 is bonded to the upper surface of the magnetic yoke 113 by adhesive within the cylindrical grooves 1132 on the left and right sides of the magnetic yoke 113. The upper surface of the second magnet 112 is lower than the upper surface of the first magnet 111 in the vertical direction, providing space for the movement of the movable coil frame 1142 and the reflector 1143 in the galvanometer chip 114.

[0050] Furthermore, after the magnetic yoke 113, the second magnet 112, and the first magnet 111 are bonded and fixed into an insert, the insert is placed in an injection mold for injection molding, thereby integrally forming the base 115. The finished base 115 is a shell, and its internal cavity is used to support the magnetic yoke 113 and the first magnet 111. In a specific embodiment, there are two protruding positioning posts 1133 on the left and right sides of the bottom of the magnetic yoke 113, which are used to position the insert during the injection molding process. This injection molding process in the above embodiment is also called embedding, which facilitates the installation and fixation of the first magnet 111, the second magnet 112, and the magnetic yoke 113, and simplifies the assembly steps of the two-dimensional scanning galvanometer device 11. Producing the base 115 through the embedding process can not only effectively fix its internal insert, but also reduce the overall size and weight of the two-dimensional scanning galvanometer device, and improve its reliability and durability. In addition, the insert process can realize automated production, which not only ensures the consistency and accuracy of the product, but also improves production efficiency and reduces production costs.

[0051] like Figure 6 As shown, the cover plate 116 in the above embodiment also includes a viewing window 1161 for the laser to enter or leave the two-dimensional scanning galvanometer device 11. In one specific embodiment, the viewing window 1161 is located in the area slightly to the left of the center of the cover plate 116, and the sidewall of the viewing window 1161 is inclined, so as to maximize the field of view covered by the detection laser reflected by the galvanometer chip 114.

[0052] In one embodiment, such as Figure 7 As shown, the internal components of the solid-state lidar 1 generate a detection laser c. The detection laser c is first received by the optical deflector 12 and reflected onto the reflector 1143 in the galvanometer chip 114. After the reflector 1143 reflects the detection laser c, it is emitted outward to achieve scanning of the detection field of view. The echo laser d that returns after being reflected by the object is first received by the reflector 1143 and deflected to the optical deflector 12. After being deflected by the optical deflector 12, it is received by the internal components of the solid-state lidar 1.

[0053] The reflector 1143 in the galvanometer chip 114 achieves two-dimensional deflection through movement around the first torsion axis 1144 and the second torsion axis 1145. Specifically, the probe laser c first strikes the light deflection device 12, and after being deflected by the light deflection device 12, it strikes the reflector 1143. The reflector 1143 reflects the probe laser c and then emits it outward, covering both the vertical and horizontal field of view, thus achieving a two-dimensional field of view scan. Specifically, the vibration of the reflector 1143 around the first torsion axis 1144 causes the probe laser c to cover the horizontal field of view, and the vibration of the reflector 1143 around the second torsion axis 1145 causes the probe laser c to cover the vertical field of view. The optical path of the echo laser d is coaxial with the optical path of the probe laser c, but in the opposite direction.

[0054] In this system, both the probe laser c and the echo laser d pass through the window 1161 on the cover plate 116, allowing the probe laser c generated in the solid-state lidar 1 to be emitted onto the object being measured. Finally, the device in the solid-state lidar 1 receives the laser reflected back from the object. In one specific embodiment, the two-dimensional scanning galvanometer device 11 in the solid-state lidar 1 is not placed vertically, but rather offset from the vertical direction and placed at a certain angle. With the position of the light deflection device 12 in the solid-state lidar 1 fixed, the window 1161 is located in the area slightly to the left of the center of the cover plate 116 to ensure that the reflector 1143 on the galvanometer chip 114 can receive and reflect the maximum amount of laser light, thereby expanding the two-dimensional field of view of the scan.

[0055] In one embodiment, such as Figure 8 As shown, the sidewall of the viewing window 1161 is inclined. Compared to a vertical sidewall, the inclined sidewall increases the transmission amount of the laser beam passing through the viewing window 1161. Specifically, as the slope of the inclined surface decreases, the number of laser beams passing through increases accordingly, which helps to expand the scanning range of the two-dimensional field of view. In this embodiment, the position of the viewing window 1161 is determined based on the installation position of the two-dimensional scanning galvanometer device 11 inside the solid-state lidar 1 and the relative position of the galvanometer chip 114. To ensure the maximum scanning range of the two-dimensional scanning galvanometer device 11, the position of the viewing window 1161 on the cover plate 16 should be adjusted accordingly based on the relative position of the two-dimensional scanning galvanometer device 11 in the solid-state lidar 1.

[0056] In one embodiment, such as Figure 9As shown, the magnetization direction 'a' of the first magnet 111 and the second magnet 112 is the thickness direction of the permanent magnet. In this embodiment, the surface of the first magnet 111 that mates with the magnetic yoke 113 is defined as the lower surface of the first magnet 111, and the surface that mates with the galvanometer chip 114 is defined as the upper surface of the first magnet 111. Specifically, the magnetic polarities of the upper and lower surfaces of the first magnet 111 and the second magnet 112 are opposite. During the magnetization process of the permanent magnet, the magnetic domain direction of the permanent magnet is parallel to the magnetization direction to avoid performance degradation caused by the inconsistency between the magnetic domain direction and the magnetization direction.

[0057] In one specific embodiment, both the first magnet 111 and the second magnet 112 employ multi-pole magnetization. Multi-pole magnetization utilizes a customized magnetization fixture, resulting in multiple N and S poles on a single plane after magnetization. In this embodiment, both the first magnet 111 and the second magnet 112 are diagonally magnetized, and multi-pole magnetization is performed. Specifically, the first magnet 111 and the second magnet 112 simultaneously exhibit N and S poles on the same plane, with the magnetic pole boundary line b as shown. Figure 9 As shown.

[0058] In this embodiment of the application, the magnetic field line cloud map generated by the magnetic field system in the two-dimensional scanning galvanometer device 11 is as follows: Figure 10 As shown, the magnetic field system composed of the first magnet 111, the second magnet 112, and the magnetically conductive yoke 113 generates relatively dense magnetic field lines, especially around the movable coil frame 1142, where the density of the magnetic field lines is more significant. This indicates that the magnetic field system in this application can provide a strong magnetic field strength around the movable coil frame 1142, thereby generating a large driving torque. In other embodiments, to further increase the magnetic field strength around the movable coil frame 1142 and improve the scanning performance of the two-dimensional field of view, a magnetically conductive sheet can be added to the surface of the first magnet 111.

[0059] like Figure 2 and 10 As shown, compared with the magnetic field system in the comparative embodiment, the magnetic field system in this embodiment can better apply and focus the magnetic field on the movable coil frame 1142. Specifically, when the current in the coil of the movable coil frame 1142 remains constant, the magnetic field system in this embodiment can enhance the magnetic field strength along the two torsional axes of the movable coil frame 1142, thereby generating a larger driving torque.

[0060] Furthermore, the magnetic field system in this embodiment can effectively reduce the overall size of the two-dimensional scanning galvanometer device 11. Specifically, since the magnetic field generated by the intermediate second magnet 112 is utilized, the size of the permanent magnet required to generate the same magnetic field strength at the movable coil frame 1142 is reduced, especially the thickness, thus reducing the overall size of the two-dimensional scanning galvanometer device 11.

[0061] In the accompanying drawings of this embodiment, the same or similar reference numerals correspond to the same or similar components. In the description of this application, it should be understood that if terms such as "upper," "lower," "left," "right," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, they are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the accompanying drawings are only for illustrative purposes and should not be construed as limiting this patent. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0062] The embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A two-dimensional scanning galvanometer device, characterized in that, It includes a first magnet, a second magnet, a magnetic yoke, a galvanometer chip, a base, a cover plate, and a flexible circuit board; The first magnet is a ring-shaped permanent magnet, which is disposed above the magnetically conductive yoke; The second magnet is a permanent magnet and is disposed above the magnetically conductive yoke. The magnetically conductive yoke is used to support the first magnet and the second magnet; The galvanometer chip is disposed above the first magnet; The first magnet, the second magnet, the magnetic yoke, and the galvanometer chip are all located inside the base; The cover plate is connected to the base and is disposed above the base; The flexible circuit board is connected to the galvanometer chip.

2. The two-dimensional scanning galvanometer device according to claim 1, characterized in that, The outer and inner contours of the first magnet are both rounded rectangles, and its surface is used for positioning and supporting the galvanometer chip.

3. The two-dimensional scanning galvanometer device according to claim 2, characterized in that, The second magnet is disposed within the rounded rectangular through hole of the first magnet.

4. The two-dimensional scanning galvanometer device according to claim 3, characterized in that, The magnetic yoke is made of a high magnetic permeability material, and the magnetic yoke is bonded to the first magnet and the second magnet respectively by adhesive in the groove.

5. The two-dimensional scanning galvanometer device according to claim 4, characterized in that, The base is a shell, and its internal cavity is used to support the magnetic yoke and the first magnet; The first magnet, the second magnet, the magnetic yoke, and the galvanometer chip are all located within the cavity of the base.

6. The two-dimensional scanning galvanometer device according to claim 2, characterized in that, The galvanometer chip includes a movable coil frame, a base, a reflector, a first torsion shaft, and a second torsion shaft; The outer contour of the movable coil frame is connected to the base via the second torsion shaft, and the inner contour of the movable coil frame is connected to the reflector via the first torsion shaft; In the vertical direction, the first torsion axis is located on both sides of the reflector; in the horizontal direction, the second torsion axis is located on both sides of the movable coil frame.

7. The two-dimensional scanning galvanometer device according to claim 6, characterized in that, The movable coil frame has multiple turns of metal conductive coil, which are positioned above the rounded rectangular through-hole area of ​​the first magnet.

8. The two-dimensional scanning galvanometer device according to claim 7, characterized in that, The cover plate is disposed above the galvanometer chip and is connected and fixed to the base; The cover plate also includes a viewing window, the sidewalls of which are sloped.

9. The two-dimensional scanning device according to claim 8, characterized in that, One end of the flexible circuit board is connected to the galvanometer chip, and the other end is connected to a power source to energize the conductive coil on the movable coil frame.

10. The two-dimensional scanning galvanometer device according to claim 9, characterized in that, The first magnet and the second magnet are magnetized using a multi-pole magnetization method; The magnetization direction of the first magnet and the second magnet is the thickness direction of the permanent magnet, and the magnetic domain direction of the permanent magnet is parallel to the magnetization direction.

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