Optical swivel mirror

Abstract

The embodiment of the application provides an optical mirror, relates to the technical field of optical structure, and is used for optical signal transceiving, and the optical mirror comprises: an optical mirror surface, a mirror frame, a rotating assembly, a permanent magnet, a plurality of electromagnets and a magnetic conducting bottom plate; the optical mirror surface is arranged on the rotating assembly through the mirror frame; the permanent magnet passes through the central region of the rotating assembly; the rotation center of the rotating assembly is located above the centroid of the permanent magnet; the first moment of force formed by the permanent magnet at the rotation center and the second moment of force formed by the optical mirror surface and the mirror frame at the rotation center realize moment of force balance; the plurality of electromagnets are arranged in a manner of surrounding the permanent magnet, wherein the air gap magnetic pole of the electromagnet forms an air gap space around the permanent magnet; the air gap space is obtained by extending the surface of the permanent magnet towards the air gap magnetic pole; the distance between the narrowest horizontal plane of the air gap space and the rotation center meets the distance threshold value; and the upper top angle of the air gap space extending upwards is set according to the criterion that the net force of the permanent magnet after rotation is minimum.

Description

Technical Field

[0001] This invention relates to the field of optical structure technology, and more particularly to an optical rotating mirror. Background Technology

[0002] Micro-Electro-Mechanical Systems (MEMS) optical mirrors, as beam control devices, have been widely used in the field of laser scanning. Currently, with the increasing maturity of MEMS mirror fabrication technology, MEMS mirrors are also frequently used in satellite laser communication for transmitting and receiving optical signals.

[0003] However, because satellite communication requires strong shock resistance and interference resistance, the dynamic mass of MEMS rotating mirrors should not be too large, and they must be balanced on both sides of the rotation center. Currently, the drive components and counterweight components of MEMS rotating mirrors are independent, resulting in a relatively large dynamic mass. Summary of the Invention

[0004] This application provides an optical rotating mirror to reduce its dynamic mass and increase its driving magnetic force.

[0005] In a first aspect, embodiments of this application provide an optical rotating mirror, including: an optical mirror surface, a mirror frame, a rotating assembly, a permanent magnet, a plurality of electromagnets, and a magnetically conductive base plate;

[0006] The optical mirror is mounted on the rotating assembly via the mirror frame, and is used to achieve large-angle scanning under the drive of the rotating assembly;

[0007] The permanent magnet passes through the central region of the rotating assembly and is used to drive the rotating assembly to rotate;

[0008] The rotation center of the rotating component is located above the center of mass of the permanent magnet; the first torque generated by the permanent magnet at the rotation center is balanced with the second torque generated by the optical mirror and the frame at the rotation center;

[0009] The plurality of electromagnets are arranged around the permanent magnet, wherein the air gap poles of the electromagnets form an air gap space around the permanent magnet; the air gap space is obtained by extending the air gap poles toward the surface of the permanent magnet; the distance between the narrowest horizontal plane of the air gap space and the center of rotation conforms to a distance threshold; the upper apex angle of the upward extension of the air gap space is set according to the criterion of minimizing the net force after the permanent magnet rotates;

[0010] The plurality of electromagnets are mounted on the magnetically conductive base plate.

[0011] In this embodiment, by placing the rotation center above the center of mass of the permanent magnet and increasing the distance from the optical mirror to the rotation center through the mirror frame, the permanent magnet is used as the driven body of the electromagnet and participates in the counterweight between it and the optical mirror, thus realizing the functional reuse of the permanent magnet and reducing the dynamic mass of the MEMS rotating mirror.

[0012] MEMS rotating mirrors with large-angle rotation typically have low lateral or vertical stiffness. When the rotating mechanism is subjected to net force in the corresponding weak direction, it will be damaged. By optimizing the air gap space, the output net force of the permanent magnet is reduced, which can avoid damage to the rotating mechanism after being subjected to net force.

[0013] The shape of the air gap space conforms to the shape of a single frustum; or

[0014] The shape of the air gap space conforms to two inverted and superimposed frustums, and the superimposed surface is the narrowest horizontal plane of the air gap space.

[0015] In this embodiment, by setting the shape of the air gap space as an inverted superimposed frustum and making the superimposed surface the narrowest horizontal plane of the air gap space, the net force generated when the electromagnet drives the permanent magnet is reduced.

[0016] The rotation center is located on the narrowest horizontal plane of the air gap space.

[0017] In this embodiment, by setting the rotation center on the narrowest horizontal plane of the air gap space, the net force is minimized and the driving efficiency is maximized.

[0018] The height of the air gap space is greater than one-third of the height of the permanent magnet.

[0019] In this embodiment, by setting the height of the air gap space to be greater than one-third of the height of the permanent magnet, the output torque of the permanent magnet is increased by increasing the facing area between the air gap magnetic poles of the electromagnet and the permanent magnet.

[0020] Optionally, the rotating assembly includes an inner frame, a first rotating shaft, a middle frame, a second rotating shaft, and an outer frame connected in sequence; the inner frame of the rotating assembly is connected to the permanent magnet and the mirror frame; the outer frame of the rotating assembly is connected to the encapsulation housing of the optical rotating mirror.

[0021] In this embodiment, the rotating assembly is connected to the outer frame and the encapsulation housing of the optical rotating mirror to fix the rotating assembly and the optical rotating mirror, ensuring the structural stability of the optical rotating mirror. The inner frame is connected to the middle frame via a first rotating shaft, and the middle frame is connected to the outer frame via a second rotating shaft, thereby driving the optical rotating mirror to rotate in the first and second axes, realizing the rotation of the optical rotating mirror in two axial directions.

[0022] In the rotation direction of the first rotating shaft, the permanent magnet drives the inner frame, the optical mirror, and the frame to rotate. In the rotation direction of the second rotating shaft, the permanent magnet drives the inner frame, the first rotating shaft, the middle frame, the optical mirror, and the frame to rotate.

[0023] The eyeglass frame includes a first connecting part, a second connecting part, and a support part located between the first connecting part and the second connecting part;

[0024] The first connecting part is used for fixed connection with the optical mirror surface;

[0025] The second connecting part is used for fixed connection with the rotating assembly;

[0026] The support portion is used to support the optical mirror after it is fixedly connected to the first connection portion, and the height of the support portion is set to satisfy the torque balance between the first torque and the second torque.

[0027] In this embodiment, the frame is divided into three parts: a first connecting part, a second connecting part, and a support part. The first connecting part connects to the optical mirror, the second connecting part connects to the rotating assembly, and the support part aligns and connects the frame to the optical mirror. During installation, the support part can be used to align the frame and the rotating assembly first, and then the second connecting part and the first connecting part can be used to sequentially fix the frame to the rotating assembly and the optical mirror, ensuring the positional relationship between the frame, the optical mirror, and the rotating assembly, and facilitating the installation of the optical mirror.

[0028] Optionally, a sensor reflector is provided on the bottom surface of the permanent magnet; the bottom surface is the side of the permanent magnet that is away from the optical mirror.

[0029] The sensor reflector is used to detect the rotation angle of the optical mirror. The optional sensor reflector generates a third torque at the center of rotation. The sum of the first torque and the third torque is balanced with the second torque.

[0030] In this embodiment, a sensor reflector is provided on the bottom surface of the permanent magnet, thereby confirming the rotation angle of the optical rotating mirror, and the sensor reflector also participates in the counterweight operation.

[0031] Optionally, the optical mirror is fabricated using semiconductor technology; or

[0032] The optical mirror is made by processing the contour of a silicon wafer as a substrate and then depositing an optical reflective film on the surface; or

[0033] The optical mirror is made by machining the outline of an aluminum block and then polishing it.

[0034] Optionally, the frame is made using semiconductor processing technology; or the frame is made using 3D printing technology.

[0035] Optionally, the rotating component is a flexible universal joint of a microelectromechanical system manufactured using semiconductor technology, and both the first and second rotating shafts of the rotating component are flexible beams.

[0036] In this embodiment of the application, by setting the rotating component as a flexible universal joint and setting the first and second rotating shafts as flexible beams, the two-dimensional rotation of the rotating component is ensured.

[0037] Optionally, the permanent magnet is made of a material with high remanence; and / or

[0038] The electromagnet includes air gap poles and magnetic poles made of magnetically conductive material, and the electromagnet coil is made of enameled wire.

[0039] Secondly, embodiments of this application provide a terminal device, including a transceiver component. The transceiver component includes a transceiver end, a fixed reflector end, and the aforementioned optical rotating mirror. The transceiver end is used to emit a light beam to the optical rotating mirror, and the optical rotating mirror is used to reflect the light beam back to the fixed reflector. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1 A schematic diagram (I) of an optical rotating mirror provided for an embodiment of this application;

[0042] Figure 2 A schematic diagram (II) of an optical rotating mirror provided for an embodiment of this application;

[0043] Figure 3 A schematic diagram (III) of an optical rotating mirror provided for an embodiment of this application;

[0044] Figure 4 A schematic diagram (four) of an optical rotating mirror provided for an embodiment of this application;

[0045] Figure 5 This is a schematic diagram of the mirror surface of an optical rotating mirror provided in an embodiment of this application;

[0046] Figure 6 A schematic diagram of the electromagnet and permanent magnet of an optical rotating mirror provided in an embodiment of this application;

[0047] Figure 7 This is a schematic diagram of the structure of a rotating assembly of an optical rotating mirror provided in an embodiment of this application;

[0048] Figure 8 This is a schematic diagram of the frame structure of an optical rotating mirror provided in an embodiment of this application;

[0049] Figure 9 This is a schematic diagram of the structure of a terminal device containing an optical rotating mirror, as provided in an embodiment of this application. Detailed Implementation

[0050] To make the objectives, technical solutions, and beneficial effects of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0051] In satellite laser communication, optical rotating mirrors are commonly used to receive and transmit optical signals. MEMS rotating mirrors are independent intelligent systems based on microelectronics and microfabrication technologies. Their internal structures are typically on the micrometer or even nanometer scale, integrating sensors, actuators, and micro-energy sources, and are widely used in aerospace and other fields. MEMS rotating mirrors are highly favored in the aerospace field due to their advantages such as large rotation angles, low power consumption, and small size. However, in the internal structure of a MEMS rotating mirror, the drive component for rotating the mirror and the counterweight component for balancing the mirror are two separate components. Therefore, the dynamic mass of the MEMS rotating mirror is still relatively large compared to the proposed solution.

[0052] In this scheme, the driving component of the MEMS rotating mirror is used as both a driver and a counterweight in the internal structure of the rotating mirror, thus reducing the dynamic mass of the MEMS rotating mirror.

[0053] Figure 1 An optical rotating mirror 100, such as a MEMS rotating mirror 100, is provided as an embodiment of this application. Figure 2 and Figure 3As shown, it includes: an optical mirror 201, a frame 202, a rotating assembly 203, a permanent magnet 204, multiple electromagnets 205, and a magnetically conductive base plate 208. The optical mirror 201 is mounted on the rotating assembly 203 via the frame 202, and is used to achieve large-angle scanning under the drive of the rotating assembly 203. The permanent magnet 204 passes through the central region of the rotating assembly 203, and is used to drive the rotating assembly 203 to rotate. The rotation center of the rotating assembly 203 is located above the center of mass of the permanent magnet 204. The first torque generated by the permanent magnet 204 at the rotation center interacts with the optical mirror 201 and the frame 208. 02 The second torque formed at the center of rotation achieves torque balance; multiple electromagnets 205 are arranged around the permanent magnet 204, wherein the air gap magnetic poles 2051 of the electromagnets 205 form an air gap space around the permanent magnet 204; the air gap space is obtained by extending the air gap magnetic poles 2051 toward the surface of the permanent magnet 204; the distance between the narrowest horizontal plane of the air gap space and the center of rotation meets the distance threshold; the upper apex angle of the upward extension of the air gap space is set according to the criterion of minimizing the net force after the permanent magnet 204 rotates; multiple electromagnets 205 are mounted on the magnetically conductive base plate 208.

[0054] In one optional implementation, the MEMS rotating mirror 100 includes, from top to bottom, an optical mirror 201, a mirror frame 202, a rotating assembly 203, a permanent magnet 204, multiple electromagnets 205, and a magnetically conductive base plate 208. The optical mirror 201 and the rotating assembly 203 are fixedly connected via the mirror frame 202. The fixing method can be adhesive dispensing, welding, fusion welding, etc., and this solution does not limit this method.

[0055] The rotating component 203 can achieve large-angle rotation, therefore the optical mirror 201 connected to the rotating component 203 can also achieve large-angle scanning. The rotating component 203 can be made of monocrystalline silicon, polycrystalline silicon, organic materials, metallic materials, or composite materials, etc., and this application does not limit this.

[0056] like Figure 4 As shown, the permanent magnet 204 passes through the center of the rotating assembly 203 and is fixedly connected to it. The permanent magnet 204 can be a cylinder or a combination of cylinders of different radii formed in one piece. The fixed connection between the rotating assembly 203 and the permanent magnet 204 is on the upper side of the permanent magnet 204. The center of rotation of the rotating assembly 203 is above the center of mass of the permanent magnet 204, so that the first torque generated by the permanent magnet 204 at the center of rotation is balanced with the second torque generated by the optical mirror 201 and the frame 202 at the center of rotation.

[0057] like Figure 5As shown, the optical mirror 201 consists of a mirror 2011 and a frame 2012, which are integrally formed. The optical mirror 201 is fixedly connected to the frame 202 via the frame 2012. The mirror 2011 can be made of silicon or aluminum-based composite material; alternatively, the mirror 2011 can be made of silicon carbide, which has a coefficient of thermal expansion close to 0, ensuring the stability of the mirror. It should be understood that the materials of the mirror 2011 and frame 2012 mentioned above are only used to understand this solution and are not intended to limit this solution. This solution does not specifically limit the choice of material for the mirror 2011. The shape of the mirror 2011 can be elliptical or circular, and the shape of the frame 2012 is consistent with that of the mirror 2011. It should be understood that the shapes of the mirror 2011 and frame 2012 are also not intended to limit this solution.

[0058] The frame 202 connects the optical mirror 201 and the rotating assembly 203, raising the optical mirror 201 to a preset height above the rotating assembly 203, thereby achieving torque balancing between the permanent magnet 204, the optical mirror 201, and the frame 202. The frame 202 can be made of the same material as the mirror, or other materials suitable for this solution can be used. The frame 202 is manufactured using MEMS processing, and positioning holes 207 are provided on both the optical mirror 201 and the rotating assembly 203. Figure 3 As shown. The shape of the active area of ​​the optical mirror 201 and the rotating component 203 is consistent. That is, if the optical mirror 201 is circular, the active area of ​​the rotating component 203 is also circular; if the optical mirror 201 is elliptical, the active area of ​​the rotating component 203 is also elliptical.

[0059] In this embodiment, the components can be fixedly connected by dispensing adhesive. Dispensing adhesive can relieve stress and reduce the impact of deformation of the optical mirror 201, the frame 202, and the rotating assembly 203 on the surface shape of the optical mirror 201. However, this application does not limit the method of fixing the components.

[0060] like Figure 6 As shown, electromagnets 205 surround permanent magnet 204. For example, four electromagnets can be evenly arranged around the permanent magnet. Driven by an external current, the electromagnets generate a controllable driving magnetic field B, thereby driving the permanent magnet to rotate with a torque τ. Each electromagnet includes a coil 2053, a magnetic pole 2052, and an air gap pole 2051, with the magnetic pole 2052 located within the coil. The air gap poles 2051 of each electromagnet 205 form an air gap space surrounding the permanent magnet 204. The angle of the air gap poles 2051 of the electromagnets 205 is the apex angle obtained by extending the air gap space upwards, which is set to minimize the net force generated by the permanent magnet 204 after rotation. Furthermore, the distance between the narrowest horizontal plane of the air gap space and the center of rotation meets a distance threshold.

[0061] When torsion occurs, the center of rotation does not coincide with the center of mass of the permanent magnet. The center of rotation is located above the permanent magnet (upward along the x-axis). A net force will be generated because the center of rotation does not coincide with the center of mass of the permanent magnet. In this embodiment, the net force is eliminated by designing the air gap magnetic pole 2051.

[0062] The coil 2053 of the electromagnet 205 is placed on the magnetically conductive base plate 208. The magnetically conductive base plate 208 is used to connect the magnetic fields generated by each electromagnet 205. Therefore, connecting the electromagnets 205 through the magnetically conductive base plate 208 can reduce the magnetic resistance, increase the magnetic field B generated by the electromagnets 205 in the air gap space, and increase the output torque of the permanent magnet 204.

[0063] In some embodiments, the permanent magnet is made of a high remanence material, such as a 120-degree high-temperature neodymium iron boron permanent magnet of grade N50H, with a sintered neodymium iron boron magnet density of 7.55×10^3 kg / m3. The air gap poles and magnetic poles of the electromagnet are made of magnetically conductive material, and the coil of the electromagnet is wound with enameled wire, such as 0.06 mm in diameter; coil height 2.5 mm; coil thickness 0.8 mm; 555 turns; internal resistance of a single coil 25.9 ohms; and internal resistance of two coils 51.8 ohms.

[0064] In some embodiments, the shape of the air gap space conforms to the shape of a single frustum; or the shape of the air gap space conforms to the shape of two inverted and superimposed frustums, with the superimposed surface being the narrowest horizontal plane of the air gap space.

[0065] In one alternative implementation, the air gap space is shaped like a frustum, such as a frustum of a cone or a truncated pyramid. Alternatively, the air gap space can be shaped like two inverted, stacked frustums, with the stacking surface of the two inverted frustums forming the narrowest horizontal plane of the air gap space.

[0066] When the air gap space is a frustum, such as the height of the frustum being 2.2mm, the radius of the top surface of the frustum being 2.1mm, and the radius of the bottom surface of the frustum being 2.68mm, the half angle of the cone obtained by extending the frustum upwards is 7.5 degrees.

[0067] In some embodiments, the center of rotation is located on the narrowest horizontal plane of the air gap space. Since the center of rotation is located above the center of mass of the permanent magnet 204, this arrangement reduces the interaction between the lower half of the permanent magnet 204 and the air gap magnetic poles 2051 after rotation, thereby reducing the air gap spacing and increasing the magnetic flux density of the air gap where the permanent magnet 204 is located. The smaller the air gap, the stronger the magnetic field formed by the electromagnet 205 at the air gap. In some embodiments, the height of the air gap space is greater than one-third the height of the permanent magnet 204. Preferably, the height of the air gap space is substantially the same as the height of the permanent magnet 204; for example, if the height of the permanent magnet 204 is approximately 3 mm, the height of the air gap space is preferably 2.8 mm.

[0068] In some embodiments, such as Figure 7 As shown, the rotating assembly 203 includes an inner frame 2031, a first rotating shaft 2032, a middle frame 2033, a second rotating shaft 2034, and an outer frame 2035 connected in sequence; the inner frame 2031 of the rotating assembly 203 is connected to the permanent magnet 204 and the lens frame 202; the outer frame 2035 of the rotating assembly 203 is connected to the encapsulation housing of the optical rotating mirror 100.

[0069] In one optional embodiment, the inner frame 2031 of the rotating assembly 203 is fixedly connected to the permanent magnet 204 and the lens frame 202. The inner frame 2031 is fixedly connected to the permanent magnet 204 in its central region. Multiple lens frames 202 are evenly distributed on the upper surface of the inner frame 2031, such as four evenly distributed lens frames, and each lens frame 202 is fixedly connected to the rotating assembly 203. The outer frame 2035 of the rotating assembly 203 is connected to the encapsulation housing of the optical rotating mirror 100.

[0070] The inner frame 2031 is connected to the middle frame 2033 via the first pivot 2032, and the middle frame 2033 is connected to the outer frame 2035 via the second pivot 2034.

[0071] In some embodiments, the inner frame 2031, the optical mirror 201, and the frame 202 are rotated in the rotation direction of the first rotating shaft 2032, and the inner frame 2031, the first rotating shaft 2032, the middle frame 2033, the optical mirror 201, and the frame 202 are rotated in the rotation direction of the second rotating shaft 2034.

[0072] An alternative implementation, such as Figure 7As shown, the optical mirror 201 can rotate in two axes: the rotation direction of the first axis 2032 and the rotation direction of the second axis 2034. In the rotation direction of the first axis 2032, the permanent magnet 204 drives the inner frame 2031, the optical mirror 201, and the frame 202 to rotate. In the rotation direction of the second axis 2034, the permanent magnet 204 drives the inner frame 2031, the first axis 2032, the middle frame 2033, the optical mirror 201, and the frame 202 to rotate. The first axis 2032 and the second axis 2034 can be perpendicular axes. The first and second axes can rotate simultaneously, thereby achieving two-dimensional rotation of the optical mirror 201.

[0073] In some embodiments, the rotating component 203 is a flexible universal joint manufactured using semiconductor technology, and both the first and second rotating shafts of the rotating component are flexible beams. Optionally, the length of the first rotating shaft is approximately 1400 μm, the length of the second rotating shaft is approximately 700 μm, and the width and height of the first and second rotating shafts are the same, with a width of approximately 22 μm and a height of approximately 300 μm.

[0074] In one alternative implementation, the rotating component 203 can be a flexible universal joint, which can enable the optical mirror 201 to rotate in different directions.

[0075] In this embodiment, the universal joint is configured to rotate in the rotational directions of the first and second shafts. The first shaft corresponds to the x-axis, meaning the universal joint's rotating assembly can rotate around the x-axis by a certain angle, such as approximately 14 degrees. The second shaft corresponds to the y-axis, meaning the universal joint's rotating assembly can rotate around the y-axis by a certain angle, such as approximately 6 degrees.

[0076] In some embodiments, such as Figure 8 As shown, the frame 202 includes a first connecting part 2021, a second connecting part 2022, and a support part 2023 located between the first connecting part and the second connecting part; the first connecting part 2021 is used to fixally connect to the optical mirror 201; the second connecting part 2022 is used to fixally connect to the rotating assembly 203; the support part 2023 is used to support the optical mirror 201 after it is fixedly connected to the first connecting part 2021, and the height of the support part 2023 is set to satisfy the torque balance between the first torque and the second torque, for example, the height of the support part 2023 is about 600-900μm.

[0077] Since the second torque formed by the optical mirror 201 and the frame 202 at the center of rotation is balanced with the first torque formed by the permanent magnet 204 at the center of rotation, the height setting of the support 2023 should satisfy the torque balance between the first torque and the second torque.

[0078] In one optional embodiment, the first connecting part 2021 is a part that is fixedly connected to the optical mirror 201, and the connection method can be adhesive bonding; the second connecting part 2022 is a part that is fixedly connected to the rotating component 203, and the connection method can be adhesive bonding; the supporting part 2023 is used to support the optical mirror 201.

[0079] Four positioning holes 207 are also provided on the inner frame 2031 of the rotating assembly 203 for connecting four eyeglass frames 202. The eyeglass frames 202 are inserted into the four positioning holes 207 and fixed to the inner frame by adhesive application. It should be understood that the shape of the positioning holes 207 can be circular or square. The number of positioning holes 207 can be four, two, or six. This application embodiment does not specifically limit the shape and number of positioning holes 207.

[0080] Optionally, the positioning hole at the center of the rotating assembly 203 for connecting the permanent magnet 204 is a round hole, and the positioning hole for connecting the eyeglass frame 202 is a square hole. The positioning hole for connecting the permanent magnet 204 is circular in shape, and the positioning hole for connecting the eyeglass frame 202 is square in shape.

[0081] The permanent magnet 204 is inserted into the center of the rotating assembly 203 through the central circular hole. If the permanent magnet 204 is a cylinder, a part of the permanent magnet 204 is inserted through the central circular hole of the rotating assembly 203 and connected by adhesive application to the inside of the circular hole and the side of the permanent magnet 204 connected thereto. If the permanent magnet 204 is a combination of cylinders with different radii, the cylinder with the smaller radius is inserted into the inside of the circular hole and connected by adhesive application to the inside of the circular hole and the side of the cylinder with the smaller radius.

[0082] In some optional embodiments, a sensor reflector 206 is provided on the bottom surface of the permanent magnet 204; the bottom surface is the side of the permanent magnet 204 away from the optical mirror 201; the sensor reflector 206 is used to detect the rotation angle of the optical mirror 201; the sensor reflector 206 generates a third torque at the center of rotation, and the first torque, the third torque and the second torque achieve torque balance.

[0083] The material of the sensor reflector 206 can be the same as that of the optical mirror 201, such as silicon, silicon carbide, or aluminum-based composite material. Other materials suitable for this solution can also be used. This application does not limit the use of such materials.

[0084] In some embodiments, the optical mirror 201 is made by depositing an optical reflective film on the surface after the silicon wafer is processed by semiconductor technology or laser processing to form its outline; or, the optical mirror is made by polishing the aluminum block after the aluminum block is processed to form its outline.

[0085] In one optional implementation, the optical mirror 201 is fabricated using semiconductor processes, such as MEMS fabrication. Alternatively, the optical mirror 201 uses a silicon wafer as a substrate, with one (or more) metal (or dielectric) thin films deposited on the silicon surface, i.e., an optical reflective film deposition process, thereby achieving requirements such as reducing or increasing light reflection, beam splitting, color separation, filtering, and polarization. Alternatively, the optical mirror 201 uses aluminum as a substrate, utilizing mechanical, chemical, or electrochemical processes to reduce the surface roughness of the workpiece to obtain a bright, smooth surface, i.e., a polishing process, thereby achieving a smooth surface or mirror-like gloss.

[0086] In some embodiments, the frame 202 is made using semiconductor processing technology; or, the frame 202 is made using 3D printing processing technology.

[0087] In some embodiments, the permanent magnet 204 includes a first part and a second part; the first part achieves self-balancing with the rotation center of the rotating assembly 203; the second part achieves balancing through the optical mirror 201, the frame 202 and the sensor reflector 206.

[0088] In one optional implementation, the permanent magnet 204 comprises two parts: a first part and a second part, with different balancing methods. The first part is self-balanced by the rotation center of the rotating assembly 203, meaning it can be balanced without additional counterweights. The second part is balanced by the optical mirror 201, the frame 202, and the sensor reflector 206.

[0089] The following examples illustrate this. Figure 4 For example, the rotation center of the universal joint is set 0.6 mm above the permanent magnet 204 and 2.6 mm from the bottom surface of the permanent magnet 204. The permanent magnet 204 consists of cylinders with diameters of 1.3 mm and 1.5 mm. Assuming the optical mirror 201 has a mass of 54 mg, for counterweight purposes, the center of gravity of the optical mirror 201 is placed 0.95 mm above the rotation center of the universal joint (where 0.95 mm includes the height of the support part of the frame of 0.8 mm and half the thickness of the optical mirror of 0.15 mm). When the external acceleration is a, the torque of the optical mirror 201 is:

[0090]

[0091] Where T1 is the torque of the optical mirror 201, a is the acceleration, M1 is the mass of the optical mirror 201, and L1 is the distance between the optical mirror 201 and the center of rotation of the universal joint.

[0092] The frame 202 has a mass of 2.10 mg, and its center of gravity is positioned 0.46 mm above the center of rotation of the gimbal. When the external acceleration is 'a', the torque on the frame 202 is:

[0093]

[0094] Where T2 is the torque of the frame 202, a is the acceleration, M2 is the mass of the frame 202, and L2 is the distance between the frame 202 and the center of rotation of the universal joint.

[0095] The permanent magnet is made of neodymium iron boron (NdFeB). The mass of the permanent magnet is divided into two parts. The first part is the portion that is balanced around the universal joint's rotation center. This self-balancing portion around the rotation center includes a 1.3mm diameter section 0.6mm above the rotation center; a 1.3mm diameter section 0.15mm below the rotation center; and a 1.5mm diameter section 0.338mm below the rotation center. The unbalanced magnet is the 1.5mm diameter section 2.112mm below the rotation center, with an equivalent mass of 28.17mg and a center of mass located 1.544mm below the rotation center. When the external acceleration is 'a', the torque of the equivalent mass permanent magnet is:

[0096]

[0097] Where T3 is the torque of the equivalent mass permanent magnet. L1 is the mass of the equivalent permanent magnet, and L2 is the distance from the center of mass of the permanent magnet to the center of rotation.

[0098] The sensor reflector 206 has a diameter of 3 mm, a thickness of 0.3 mm, and contains a 0.1 mm recess. It has a mass of 4.52 mg, and its center of mass is located 2.75 mm below the center of rotation. When the external acceleration is 'a', the torque of the sensor reflector 206 is:

[0099]

[0100] Where T4 is the torque of sensor reflector 206, M4 is the mass of sensor reflector 206, and L3 is the distance from the center of mass of sensor reflector 206 to the center of rotation.

[0101] At this time, the torque at the upper part of the universal joint is the torque of the optical mirror 201 and the frame 202, and the torque at the lower part of the universal joint is the torque of the unbalanced permanent magnet and the sensor reflector 206.

[0102] The upper and lower torques of the universal joint are respectively:

[0103]

[0104]

[0105] When there is an external acceleration 'a' on both the upper and lower sides of the universal joint, the torque is basically balanced.

[0106] In this embodiment, the optical rotating mirror has a mass of 54 mg, the permanent magnet has a mass of 40 mg, the sensor mirror has a mass of 4.52 mg, and the frame has a mass of 2.1 mg, for a total dynamic mass of 100.62 mg. In a conventional approach, when the center of mass of the permanent magnet is located at the rotation center of the rotating assembly, an additional mass equal to that of the optical rotating mirror is required to balance the lever arms of the dynamic masses at both ends of the rotating mechanism, resulting in a dynamic mass greater than 150 mg. In contrast, this embodiment achieves a weight reduction of more than 30%, significantly improving the vibration resistance of the rotating mirror.

[0107] Meanwhile, by setting up a frustum-shaped air gap space and using a 50mA current to excite the electromagnet, the torque generated by the permanent magnet is greater than 40μN·m. At the same time, the net force in each direction is less than 3mN, which is on the same order of magnitude as the previous solution, thus avoiding damage to the rotating components caused by the net force.

[0108] This application provides a terminal device, such as... Figure 9 As shown, it includes a transceiver assembly, which includes a transceiver end 30, a fixed reflector 40, and an optical rotating mirror array 10. The transceiver end 30 is used to emit a light beam to the optical rotating mirror array 10.

[0109] In one optional implementation, the optical rotating mirror array 10 can be used for receiving or transmitting optical signals at the front end, or for optical path processing at the back end. Its pointing accuracy and stability for receiving and transmitting optical signals are higher than those of traditional optical rotating mirrors.

[0110] The above embodiment is one example provided by this application. Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if these modifications and variations of this application fall within the scope of the claims of this application and their equivalents, this application also intends to include these modifications and variations.

Claims

1. An optical swivel mirror, characterized in that The application relates to an optical mirror, which comprises an optical mirror surface, a mirror frame, a rotating assembly, a permanent magnet, a plurality of electromagnets and a magnetic conducting bottom plate. The optical mirror surface is arranged on the rotating assembly through the mirror frame and is used for realizing large-angle scanning under the driving of the rotating assembly. The permanent magnet passes through the central region of the rotating assembly and is used for driving the rotating assembly to rotate. The rotation center of the rotating assembly is located above the center of mass of the permanent magnet; a first moment of force formed by the permanent magnet at the rotation center and a second moment of force formed by the optical mirror surface and the mirror frame at the rotation center realize moment of force balance; the mirror frame comprises a first connecting part, a second connecting part and a supporting part located between the first connecting part and the second connecting part; the first connecting part is used for fixedly connecting with the optical mirror surface; the second connecting part is used for fixedly connecting with the rotating assembly; the supporting part is used for supporting the optical mirror surface after the optical mirror surface is fixedly connected with the first connecting part; the height of the supporting part is set to satisfy the moment of force balance between the first moment of force and the second moment of force. The plurality of electromagnets are arranged in a manner surrounding the permanent magnet, wherein the air gap magnetic poles of the electromagnets form an air gap space around the permanent magnet; the air gap space is obtained by extending the air gap magnetic poles towards the surface of the permanent magnet; the distance between the narrowest horizontal plane of the air gap space and the rotation center meets a distance threshold value. The upper top angle of the air gap space extending upwards is set according to the criterion that the net force after the permanent magnet rotates is minimum. The plurality of electromagnets are mounted on the magnetic conducting bottom plate. The shape of the air gap space meets a single frustum shape; or 2. The optical swivel as claimed in claim 1, characterized in that The shape of the air gap space meets two inverted and superimposed frustums, and the superimposed surface is the narrowest horizontal plane of the air gap space. The rotation center is located on the narrowest horizontal plane of the air gap space.

3. The optical swivel as claimed in claim 1, wherein The height of the air gap space is greater than one third of the height of the permanent magnet.

4. The optical swivel as claimed in claim 1, wherein, The rotating assembly comprises an inner frame, a first rotating shaft, a middle frame, a second rotating shaft and an outer frame which are sequentially connected; the inner frame of the rotating assembly is connected with the permanent magnet and the mirror frame; the outer frame of the rotating assembly is connected with the packaging shell of the optical rotating mirror.

5. A flip mirror as claimed in any one of claims 1 to 4, wherein The permanent magnet drives the inner frame, the optical mirror surface and the mirror frame to rotate in the rotating direction of the first rotating shaft; the permanent magnet drives the inner frame, the first rotating shaft, the middle frame, the optical mirror surface and the mirror frame to rotate in the rotating direction of the second rotating shaft.

6. The optical swivel as claimed in claim 5, characterized in that The bottom surface of the permanent magnet is provided with a selected sensor mirror; the bottom surface is a surface of the permanent magnet which is far away from the optical mirror surface; 7. The optical swivel according to any one of claims 1 to 4, wherein The sensor mirror is used for detecting the rotating angle of the optical mirror surface; the selected sensor mirror forms a third moment of force at the rotation center; the sum of the first moment of force and the third moment of force and the second moment of force realize moment of force balance. The optical mirror surface is made of a semiconductor process; or 8. The optical swivel according to any one of claims 1 to 4, characterized in that The optical mirror surface is made by using a silicon wafer as a base material to process a profile and then coating an optical reflection film on the surface; or The optical mirror surface is made by using an aluminum block as a base material to process a profile and then polishing. ​ 9. The optical swivel according to any one of claims 1 to 4, wherein The mirror frame is made of a semiconductor processing technology; or the mirror frame is made of a 3D printing processing technology.

10. The optical swivel as claimed in any one of claims 1 to 4, characterized in that The rotating assembly is a flexible universal joint made of a semiconductor processing technology, and the first rotating shaft and the second rotating shaft of the rotating assembly are flexible beams.

11. A terminal device, comprising: The application further provides a receiving and transmitting assembly comprising a receiving and transmitting end, a fixed mirror and the optical rotating mirror according to any one of claims 1 to 10, wherein the receiving and transmitting end is configured to emit a light beam to the optical rotating mirror, and the optical rotating mirror is configured to reflect the light beam to the fixed mirror.

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