MEMS scanning module and electromagnetic scanning module

Abstract

The utility model discloses an MEMS scanning module and an electromagnetic scanning module. The MEMS scanning module includes: an MEMS scanner having a frame and a mirror rotatable relative to the frame along a torsion beam; the two limiting structures are respectively connected with the MEMS scanner from the upper side and the lower side of the MEMS scanner; wherein each limiting structure comprises two limiting units, the two limiting units are located on the same side of the MEMS scanner, and a movable part in the MEMS scanner is limited through the two limiting structures. The limiting structures are arranged on the upper side and the lower side of the MEMS scanner, so that the displacement amount of a movable part in the MEMS scanner in the impact process is limited, the deformation amount of the movable part is controlled, and the impact resistance and the reliability of the movable part are improved; the magnet in the electromagnetic scanning module is arranged corresponding to the limiting structure, and the limiting structure can play a role in magnetic conduction, so that the effects of converging and enhancing the magnetic field are realized.

Description

Technical Field

[0001] The utility model relates to the field of microelectronic machinery, and more specifically, to a MEMS scanning module and an electromagnetic scanning module. Background Art

[0002] Electromagnetic scanning modules have important applications in laser projection, augmented reality, laser radar and other fields. The core of the electromagnetic scanning module is the MEMS scanner, which realizes the projection of reflected light at different angles by twisting the mirror. Electromagnetic scanning modules based on micro-electromechanical systems (MEMS) have the advantages of small size, light weight and low price. In recent years, they have formed a strong trend to replace traditional optical scanning modules.

[0003] The MEMS scanner in the electromagnetic scanning module can be driven by various methods such as electrostatic, electromagnetic, piezoelectric, and electrothermal. Electromagnetic drive has the advantages of large driving force, large scanning angle, and low operating voltage, which greatly meets the application requirements of vehicle-mounted lidar. The principle of electromagnetic drive lies in the Lorentz force generated by the energized coil in the magnetic field. Therefore, it is usually necessary to integrate permanent magnets into the electromagnetic scanning module, and the magnetic field distribution in the electromagnetic scanning module needs to be specially designed to ensure the best effect of electromagnetic drive.

[0004] In-vehicle applications place high demands on the reliability of electromagnetic scanning modules. Due to the frequent acceleration and deceleration during vehicle movement and the potential risk of collision, the electromagnetic scanning module needs to be able to withstand certain vibration loads and impact loads. Existing electromagnetic scanning modules increase their vibration loads and impact loads by widening the width of the torsion beam and improving the rigidity of the torsion beam. However, this method will cause a larger current to drive the mirror deflection and higher power consumption, which may not only cause the coil to fuse, but also significantly increase the risk of failure of its electronic control part.

[0005] We look forward to further improving the electromagnetic scanning module to enhance its impact resistance and reliability so that it can be used in a variety of application scenarios. Utility Model Content

[0006] In view of this, the purpose of the present invention is to provide a MEMS scanning module and an electromagnetic scanning module to improve their impact resistance and reliability to adapt to various application scenarios.

[0007] According to one aspect of the utility model, a MEMS scanning module is provided, comprising: a MEMS scanner having a frame and a mirror that can rotate relative to the frame along a torsion beam; two limiting structures, wherein the two limiting structures are respectively connected to the MEMS scanner from the upper and lower sides of the MEMS scanner; wherein each of the limiting structures comprises two limiting units, the two limiting units are located on the same side of the MEMS scanner, and the movable part in the MEMS scanner is limited by the two limiting structures.

[0008] Optionally, the limiting unit includes a limiting frame and a limiting plate, and the limiting frame matches with at least a portion of the side edge of the first frame of the MEMS scanner through a groove.

[0009] Optionally, the limiting frame is L-shaped, and the limiting plate is located at an inner side of the limiting frame and connected to the limiting frame.

[0010] Optionally, the MEMS scanner also includes a second frame and a third frame, the first frame is located outside the third frame, the third frame is located outside the second frame, the second frame and the third frame are respectively provided with a first coil and a second coil, the third frame is connected to the first frame via a first torsion beam arranged along a first direction, the second frame is connected to the third frame via a second torsion beam arranged along a second direction, the mirror is located in the central area of ​​the second frame, and the first direction is perpendicular to the second direction.

[0011] Optionally, the two limiting structures limit the movement range of the third frame in the MEMS scanner.

[0012] Optionally, the limiting plate is provided with at least one protrusion on a side facing the MEMS scanner, and the protrusion corresponds to the third frame.

[0013] Optionally, the protrusion comprises two, and the two protrusions are symmetrically arranged along the first torsion beam.

[0014] Optionally, the protrusion includes at least one of a dot shape, a hemispherical shape, a truncated cone shape, a prism shape, and a rectangular parallelepiped shape.

[0015] Optionally, the first coil and the second coil are staggered with the protrusion to avoid contact between the protrusion and the first coil or the second coil.

[0016] Optionally, the third frame further includes a protruding structure extending outward, and the protruding structure corresponds to the position of the protrusion.

[0017] Optionally, there is a preset distance between the top of the protrusion and the first frame, and the preset distance is not less than 100 microns and not more than 10 millimeters.

[0018] Optionally, the limiting structure is a magnetic conductive structure, and the magnetic conductive structure includes one of iron, low carbon steel, iron-silicon alloy, iron-aluminum alloy, iron-silicon-aluminum alloy, nickel-iron alloy, iron-cobalt alloy, soft ferrite, and amorphous soft magnetic alloy.

[0019] According to another aspect of the utility model, an electromagnetic scanning module is provided, comprising the above-mentioned MEMS scanning module and a magnet assembly corresponding to the MEMS scanning module, wherein the magnet assembly is located on at least one side of the MEMS scanning module to provide a magnetic field for the MEMS scanning module.

[0020] Optionally, the magnet assembly includes: a first magnet and a second magnet, both of which are L-shaped, the first magnet and the second magnet are arranged end to end relative to each other, and the first magnet and the second magnet are located below the MEMS scanning module; a third magnet and a fourth magnet, both of which are L-shaped, the third magnet and the fourth magnet are arranged end to end relative to each other, and the third magnet and the fourth magnet are located above the MEMS scanning module.

[0021] Optionally, various parts of the magnet assembly and the magnet assembly and the MEMS scanning module are bonded together by an adhesive.

[0022] Beneficial effects of the utility model:

[0023] The MEMS scanning module and electromagnetic scanning module provided by the utility model limit the displacement of the movable part in the MEMS scanner during the impact process by setting a limit structure at the larger stroke of the MEMS scanner, so as to control its deformation, reduce the maximum stress on the movable part, improve its impact resistance, and enhance reliability; further, the design can improve reliability without increasing the width of the torsion beam, so that the width of the torsion beam is thinner, which can meet the requirements of low current and low power consumption to drive the MEMS scanner to deflect, and enhance sensitivity; the limit structure can also free up movement space within the stroke range for the movable part of the MEMS scanner without blocking the entry and exit of light.

[0024] The magnet assembly in the electromagnetic scanning module is set corresponding to the limit structure. The limit structure can be made of magnetic conductive material, which can play a magnetic conductive function, realize the role of converging and enhancing the magnetic field, so as to ensure that the mirror has a larger deflection angle. The electromagnetic scanning module using the MEMS scanning module not only has better impact resistance and better reliability, but also can realize low power consumption drive. The electromagnetic scanning module has a simple and reliable structure and is easy to mass produce. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The above and other objects, features and advantages of the present invention will become more apparent through the following description of the embodiments of the present invention with reference to the accompanying drawings.

[0026] Figure 1 A schematic diagram showing a MEMS scanning module according to a first embodiment of the utility model;

[0027] Figure 2 An exploded schematic diagram showing a MEMS scanning module according to a first embodiment of the utility model;

[0028] Figure 3 A schematic diagram showing a MEMS scanner according to a first embodiment of the present invention;

[0029] Figure 4 A schematic diagram showing a MEMS scanner according to a second embodiment of the present invention;

[0030] Figure 5 A schematic diagram showing a first position limiting structure of a MEMS scanning module according to a first embodiment of the utility model;

[0031] Figure 6 A schematic diagram showing a first limiting unit of a MEMS scanning module according to a second embodiment of the utility model;

[0032] Figure 7 A schematic diagram showing a first limiting unit of a MEMS scanning module according to a third embodiment of the utility model;

[0033] Figure 8 A schematic diagram showing a first limiting unit of a MEMS scanning module according to a fourth embodiment of the utility model;

[0034] Fig. 9 A cross-sectional schematic diagram showing a MEMS scanning module according to a first embodiment of the utility model;

[0035] Fig.10a and Fig.10b Schematic cross-sectional views of the upper limit state and the lower limit state of the MEMS scanning module of the first embodiment of the utility model are respectively shown;

[0036] Fig.11 A schematic diagram of an electromagnetic scanning module according to a first embodiment of the present utility model is shown. DETAILED DESCRIPTION

[0037] Various embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. In each of the accompanying drawings, the same elements are represented by the same or similar reference numerals. For the sake of clarity, the various parts in the accompanying drawings are not drawn to scale.

[0038] The utility model is further described below in conjunction with the accompanying drawings and embodiments.

[0039] Figure 1A schematic diagram of a MEMS scanning module of the first embodiment of the utility model is shown; the MEMS scanning module includes a MEMS scanner 300, a first limiting structure 100 and a second limiting structure 200, wherein the MEMS scanner 300 has a frame and a mirror that can rotate relative to the frame along a torsion beam, the first limiting structure 100 is, for example, located above the MEMS scanner 300 to provide an upper limit for the MEMS scanner 300; the second limiting structure 200 is, for example, located below the MEMS scanner 300 to provide a lower limit for the MEMS scanner 300. The first limiting structure 100 and the second limiting structure 200, for example, each include two limiting units, specifically, the first limiting structure 100 includes a first limiting unit 110 and a second limiting unit 120, which are arranged end to end to form a rectangular frame; similarly, the second limiting structure 200 includes a third limiting unit 210 and a fourth limiting unit 220, which are also arranged end to end to form a rectangular frame. The first limiting structure 100 is located above the MEMS scanner 300, and the second limiting structure 200 is located below the MEMS scanner 300 and is arranged opposite to the first limiting structure 100. The two limiting structures fix and clamp the MEMS scanner 300 from the upper and lower sides of the MEMS scanner 300. The first limiting structure 100 and the second limiting structure 200 can be, for example, magnetic conductive structures, and the magnetic conductive structures include one of pure iron, low carbon steel, iron-silicon alloy, iron-aluminum alloy, iron-silicon-aluminum alloy, nickel-iron alloy, iron-cobalt alloy, soft ferrite, and amorphous soft magnetic alloy, so that the first limiting structure 100 and the second limiting structure 200 can not only act as magnetic conductive sheets for magnetic conductivity, but also limit the maximum stroke of the torsion beam during the impact process, protect the torsion beam in the MEMS scanner 300, and reduce the possibility of its fracture failure.

[0040] Figure 2 An exploded schematic diagram of a MEMS scanning module according to a first embodiment of the present invention is shown. Figure 2It can be seen that the first limiting frame 111 and the first limiting plate 112 serve as the first limiting unit 110, wherein the first limiting frame 111 is, for example, an L-shaped plate, and a first groove 1111 is provided on the surface of the first frame 310 facing the MEMS scanner 300. The first groove 1111 is, for example, located on the inner side of the L-shaped first limiting frame 111 and is also L-shaped. The outer contour of the first frame 310 of the MEMS scanner 300 is, for example, a rectangle, and the first groove 1111 matches the two adjacent sides of the first frame 310, so that at least part of the first frame 310 can be embedded in the first groove 1111. The first limiting plate 112 is, for example, rectangular, and one side of the first limiting plate 112 is connected to the inner side of the short side of the L-shaped first limiting frame 111. Furthermore, the first limiting plate 112 and the first limiting frame 111 are an integrated structure. The first limiting plate 112 corresponds to the movable part in the MEMS scanner 300. Specifically, the first limiting plate 112 corresponds to the position of the third frame 330 in the MEMS scanner 300. Two first protrusions 1121 are provided on the surface of the first limiting plate 112 facing the MEMS scanner 300. The first protrusions 1121 are used to limit the travel of one side of the third frame 330 in the MEMS scanner 300, so as to reduce the risk of the first torsion beam 311 breaking and failing when subjected to a large impact. The first protrusions 1121 are, for example, point-shaped protrusions, and the two first protrusions 1121 are symmetrically arranged about the first torsion beam 311. Of course, the shape of the first protrusion 1121 can also be other shapes such as hemispherical, truncated cone, prism, cuboid, etc. Similarly, the second limiting unit 120 is also similar to the first limiting unit 110. The second limiting unit 120 and the first limiting unit 110 are coplanar and arranged end to end. Specifically, the second limiting unit 120 includes a second limiting frame 121 and a second limiting plate 122. The second limiting frame 121 is also L-shaped, and a second groove (blocked in the figure and invisible) is provided on one side of the first frame 310 facing the MEMS scanner 300. The second groove is, for example, located on the inner side of the L-shaped second limiting frame 121 and is also L-shaped. The second groove matches the other two side edges of the first frame 310, so that at least part of the first frame 310 can be embedded in the second groove.The second limiting plate 122 is, for example, rectangular, and one side edge of the second limiting plate 122 is connected to an inner side edge of the L-shaped second limiting frame 121. The second limiting plate 122 is arranged opposite to the first limiting plate 112. Furthermore, the second limiting plate 122 and the second limiting frame 121 are an integrated structure. The second limiting plate 122 also corresponds to the third frame 330 in the MEMS scanner 300. Two second protrusions 1221 are arranged on a surface of one side facing the MEMS scanner 300. The two second protrusions 1221 are symmetrically arranged about the first torsion beam 311 to limit the other side travel of the third frame 330 of the MEMS scanner 300, thereby reducing the risk of breakage and failure of the first torsion beam 311 when subjected to a large impact.

[0041] The MEMS scanner 300 includes a first frame 310, a second frame 320 and a third frame 330. The first frame 310 is located outside the third frame 330, and the third frame 330 is located outside the second frame 320. The third frame 330 is connected to the first frame 310 through first torsion beams 311 on both sides, and the first torsion beams 311 are arranged along a first direction; the second frame 320 is connected to the inner side of the third frame 330 through second torsion beams 321 on both sides, and the second torsion beams 321 are arranged along a second direction. Specifically, the first direction is perpendicular to the second direction. A mirror 340 is arranged in the central area of ​​the second frame 320. By twisting the second frame 320 and / or the third frame 330 along the torsion beam, the direction of the mirror 340 is changed, and then the direction of the light reflected by the mirror 340 is changed, so as to realize the scanning function. The first frame 310 is, for example, rectangular, and a circular through hole is provided in the middle area of ​​the first frame 310. The third frame 330 is, for example, annular and located in the through hole, and the third frame 330 is connected to the inner side of the first frame 310 through the first torsion beam 311. The second frame 320 is, for example, circular, and the second frame 320 is located inside the third frame 330, and is connected to the inner side of the third frame 330 through the second torsion beam 321.

[0042] A second limiting structure 200 is arranged below the MEMS scanner 300, and the second limiting structure 200 includes a third limiting unit 210 and a fourth limiting unit 220. The third limiting frame 211 and the third limiting plate 212 constitute the third limiting unit 210. Similarly, the third limiting frame 211 is also an L-shaped plate, and a third groove 2111 is arranged on a side surface facing the first frame 310. The third groove 2111 is, for example, located on the inner side of the L-shaped third limiting frame 211 and is also L-shaped. The third groove 2111 matches the two adjacent side edges of the first frame 310, so that At least part of the first frame 310 can be embedded in the third groove 2111, and the third groove 2111 and the first groove 1111 clamp and fix at least part of the two side edges of the first frame 310 from the upper and lower sides of the first frame 310. The third limiting plate 212 is, for example, rectangular, and one side edge of the third limiting plate 212 is connected to the inner side edge of the short side of the L-shaped third limiting frame 211. Further, the third limiting plate 212 and the third limiting frame 211 are an integrated structure, and the third limiting plate 212 corresponds to the position of the third frame 330 in the MEMS scanner 300. Two third protrusions 2121 are provided on the side of the third limiting plate 212 facing the MEMS scanner 300, and the two third protrusions 2121 are respectively located at the two corners of the third limiting plate 212 away from the third limiting frame 211. The third protrusion 2121 is used to limit the travel of one side of the third frame 330 in the MEMS scanner 300 to reduce the risk of the first torsion beam 311 breaking and failing when subjected to a large impact. The third protrusion 2121 is, for example, a dot-shaped protrusion, and two third protrusions 2121 are symmetrically arranged about the first torsion beam 311. Of course, the shape of the third protrusion 2121 can also be other shapes such as a hemisphere, a truncated cone, a prism, or a cuboid.

[0043] The fourth limiting frame 221 and the fourth limiting plate 222 constitute the fourth limiting structure 220. The fourth limiting frame 221 is L-shaped, and a fourth groove 2211 is provided on the surface of the side facing the first frame 310. The fourth groove 2211 and the second groove of the second limiting frame 121 clamp and fix at least part of the other two side plates of the first frame 310 from the upper and lower sides of the first frame 310. The fourth limiting plate 222 is also similar to the third limiting plate 212. The fourth limiting plate 222 is provided with two fourth protrusions 2221. In this embodiment, for example, two protrusions are provided on each limiting plate, and the protrusions on the upper and lower limiting plates opposite to each other also correspond to each other, so that the limiting function can be realized on both the upper and lower sides of the MEMS scanner 300, reducing the risk of the first torsion beam 311 breaking and failing when the MEMS scanner 300 is subjected to a large impact.

[0044] Figure 3A schematic diagram of a MEMS scanner of a MEMS scanning module according to a first embodiment of the utility model is shown; the MEMS scanner comprises a first frame 310, a third frame 330, a second frame 320 and a mirror 340 located on the second frame 320. The first frame 310 is, for example, rectangular, with a circular through hole in the middle, the third frame 330 is located in the circular through hole, the third frame 330 is, for example, annular, the second frame 320 is located inside the third frame 330, the second frame 320 is, for example, circular, there is, for example, a gap between the third frame 330 and the first frame 310, and between the second frame 320 and the third frame 330, the second frame 320 is connected to the inner side of the third frame 330 through the second torsion beams 321 on both sides thereof, so that the second frame 320 can rotate relative to the third frame 330 along the second torsion beams 321; the third frame 330 is connected to the first frame 310 through the first torsion beams 311 on both sides thereof, so that the third frame 330 can rotate relative to the first frame 310 along the first torsion beams 311. Furthermore, a first coil (not shown in the figure) is also provided on the second frame 320, and a second coil (not shown in the figure) is provided on the third frame 330. Under the action of the magnetic field, by energizing the first coil and / or the second coil, the mirror 340 on the second frame 320 can rotate along the second torsion beam 321 and / or the first torsion beam 311. Furthermore, the coil needs to avoid the area corresponding to the first protrusion 1121 and the second protrusion 1221 to prevent the coil from contacting the first protrusion 1121 and the second protrusion 1221.

[0045] In this embodiment, the travel of the third frame 330 is limited by the limiting unit, which can effectively reduce the deformation degree of the first torsion beam 311 and improve its impact resistance, so that the first torsion beam 311 can be designed to be more slender to improve its sensitivity.

[0046] Figure 4 A schematic diagram of a MEMS scanner of a MEMS scanning module according to a second embodiment of the utility model is shown; the MEMS scanner of the second embodiment is similar to that of the first embodiment, and the same parts thereof are not repeated here. The difference between the MEMS scanner of the second embodiment and that of the first embodiment is that the edge of the third frame 330 is also provided with a protruding structure 331 extending outward, and specifically, the protruding structure 331 is provided with, for example, four protruding structures 331, and the protruding structures 331 are symmetrically arranged along the first torsion beam 311. The position of the protruding structure 331 corresponds to the position of the first protrusion 1121 and the second protrusion 1221, and the protruding structure 331 contacts the first protrusion 1121 and the second protrusion 1221 to avoid direct contact between the coil and the first protrusion 1121 and the second protrusion 1221.

[0047] To better show Figure 2The first limiting structure in the embodiment is flipped to obtain Figure 5 The view shown, from Figure 5 As can be seen in the figure, the first limiting structure 100 includes a first limiting unit 110 and a second limiting unit 120 which are arranged end to end opposite to each other. The first limiting unit 110 includes a first limiting frame 111 and a first limiting plate 112, wherein the first limiting frame 111 is, for example, an L-shaped plate, and a first groove 1111 is provided on the surface of the first frame 310 of the MEMS scanner 300, and the first groove 1111 is, for example, located on the inner side of the L-shaped first limiting frame 111 and is also L-shaped, and the outer contour of the first frame 310 of the MEMS scanner 300 is, for example, a rectangle, and the first groove 1111 matches the two adjacent sides of the first frame 310, so that at least a portion of the first frame 310 can be embedded in the first groove 1111. The first limiting plate 112 is, for example, rectangular, and one side of the first limiting plate 112 is connected to the inner side of the short side of the L-shaped first limiting frame 111. Furthermore, the first limiting plate 112 and the first limiting frame 111 are an integrated structure. The first limiting plate 112 corresponds to the movable part in the MEMS scanner 300. Specifically, the first limiting plate 112 corresponds to the position of the third frame 330 in the MEMS scanner 300. Two first protrusions 1121 are provided on the surface of the first limiting plate 112 facing the MEMS scanner 300. The first protrusions 1121 are used to limit the travel of one side of the third frame 330 in the MEMS scanner 300, so as to reduce the risk of the first torsion beam 311 breaking and failing when subjected to a large impact. The first protrusions 1121 are, for example, point-shaped protrusions, and the two first protrusions 1121 are symmetrically arranged about the first torsion beam 311. Of course, the shape of the first protrusion 1121 can also be other shapes such as hemispherical, truncated cone, prism, cuboid, etc. Similarly, the second limiting unit 120 is also similar to the first limiting unit 110. The second limiting unit 120 and the first limiting unit 110 are coplanar and arranged end to end oppositely. The second limiting unit 120 is similar to the first limiting unit 110 and will not be described in detail.

[0048] Further, Figure 6 , Figure 7 and Figure 8 Schematic diagrams of the second embodiment, the third embodiment and the fourth embodiment of the first limiting unit are shown respectively. Figure 6 As shown, the first limiting unit 110 of the second embodiment also includes a first limiting frame 111 and a first limiting plate 112. The first limiting frame 111 is also provided with a first groove 1111. The difference is that the first limiting plate 112 has only one first protrusion, and the shape of the first protrusion is the same as that of the first limiting plate 112. It can be understood that the thickness of the first limiting plate 112 is increased as a whole. Figure 7FIG. 1 is a schematic diagram of a third embodiment of the first position limiting unit, which also has two first protrusions 1121, and the first protrusions 1121 are rectangular parallelepiped, respectively arranged on both sides of the first position limiting plate 112, and the two first protrusions 1121 are symmetrically arranged about the first torsion beam 311. Figure 8 As shown, in the fourth embodiment of the first limiting unit 110 , only one first protrusion 1121 is provided on the first limiting plate 112 . The first protrusion 1121 is also a rectangular parallelepiped and is located on the side of the first limiting plate 112 away from the first limiting frame 111 .

[0049] In summary, the MEMS scanner can achieve the limiting function by contacting the protrusions on the limiting plate, and the number, shape and position of the corresponding protrusions can be adjusted according to needs.

[0050] Fig. 9 A cross-sectional schematic diagram of a MEMS scanning module according to a first embodiment of the present utility model is shown; Fig. 9 It can be seen that the first limiting structure 100 and the second limiting structure 200 fix and clamp the first frame 310 from the upper and lower sides of the first frame 310, the first protrusion 1121 and the second protrusion 1221 correspond to the upper surface of the third frame 330, the third protrusion 2121 and the fourth protrusion 2221 correspond to the lower surface of the third frame 330, and the first protrusion 1121 is opposite to the third protrusion 2121, and the second protrusion 1221 is opposite to the fourth protrusion 2221.

[0051] Specifically, the above-mentioned protrusions are, for example, hemispherical, and the MEMS scanning module is, for example, bilaterally symmetrical. Fig. 9 Taking the second protrusion 1221 and the fourth protrusion 2221 on the left side as an example, the distance between the top of the second protrusion 1221 and the upper surface of the third frame 330 is h1, and the distance between the top of the fourth protrusion 2221 and the lower surface of the third frame 330 is h2, and the limiting structure will not hinder the normal deflection of the mirror 340. Further, h1 is not less than 100 microns and not more than 10 mm, and h2 has the same size range as h1. Fig.10a and Fig.10b The schematic cross-sectional views of the third frame 330 moving to the upper limit position state and the lower limit position state are shown respectively. Fig. 9 It can be seen that the upper stroke of the third frame 330 is limited to a range less than or equal to h1, and the lower stroke is limited to a range less than or equal to h2. By limiting the stroke of the third frame 330, excessive deformation of the first torsion beam 311 can be effectively avoided, and the risk of root fracture and failure of the first torsion beam 311 can be reduced. Since the limiting structure in this embodiment is used to limit the stroke of the third frame 330, it will not affect the rotation of the mirror 340. Of course, the protrusion can also be set to other shapes such as point shape, truncated cone shape, prism shape, rectangular parallelepiped shape, etc.

[0052] by Fig. 9 Taking the first limiting frame 111 and the third limiting frame 211 on the right side as an example, the thickness of the first frame 310 is, for example, D, the depth of the first groove of the first limiting frame 111 is, for example, d1, and the depth of the third groove of the third limiting frame 211 is, for example, d2, wherein the thickness D of the first frame 310 is, for example, the sum of d1 and d2, so that the first limiting frame 111 and the third limiting frame 211 can clamp the first frame 310, of course, the thickness D of the first frame can also be slightly less than the sum of d1 and d2, and the gap is filled by adhesive to fix the first frame 310 to the first limiting frame 111 and the third limiting frame 211. The second limiting frame 121 and the fourth limiting frame 221 on the left side are similar to the first limiting frame 111 and the third limiting frame 211, and will not be repeated.

[0053] Fig.11 The schematic diagram of the electromagnetic scanning module of the first embodiment of the utility model is shown. The electromagnetic scanning module includes a MEMS scanning module and a magnet assembly for providing a magnetic field arranged on the upper and lower sides of the MEMS scanning module. Specifically, the magnet assembly includes a first magnet 410, a second magnet 420, a third magnet 510 and a fourth magnet 520, wherein the first magnet 410, the second magnet 420, the third magnet 510 and the fourth magnet 520 are, for example, all L-shaped, the first magnet 410 and the second magnet 420 have the same shape and size, and the third magnet 510 and the fourth magnet 520 have the same shape and size. The thickness of the first magnet 410 and the second magnet 420 is greater than the thickness of the third magnet 510 and the fourth magnet 520. The first magnet 410 and the second magnet 420 are arranged head to tail to form a rectangular frame, and the hollow part in the middle corresponds to the movable part in the MEMS scanner 300, providing a movement space for the movable part in the MEMS scanner 300. The first magnet 410 and the second magnet 420 are respectively located below the third limiting unit 210 and the fourth limiting unit 220. The third magnet 510 and the fourth magnet 520 are arranged end to end to form a rectangular frame, and the hollow part in the middle also corresponds to the movable part in the MEMS scanner 300. The third magnet 510 and the fourth magnet 520 are respectively located above the first limiting unit 110 and the second limiting unit 120. The magnet assembly formed by the first magnet 410, the second magnet 420, the third magnet 510 and the fourth magnet 520 can provide the required magnetic field on the upper and lower sides of the MEMS scanner 300. Of course, according to actual needs, the magnet assembly can also adopt other shapes, or the magnet assembly can be only arranged above or below the MEMS scanner 300 to provide a magnetic field, and the parts of the magnet assembly and the magnet assembly and the MEMS scanner 300 are connected and fixed by adhesives, for example.

[0054] The MEMS scanning module and electromagnetic scanning module provided by the utility model limit the displacement of the movable part in the MEMS scanner during the impact process by setting a limit structure at the larger stroke of the MEMS scanner, so as to control its deformation, reduce the maximum stress on the movable part, improve its impact resistance, and enhance reliability; further, the design can improve reliability without increasing the width of the torsion beam, so that the width of the torsion beam is thinner, which can meet the requirements of low current and low power consumption to drive the MEMS scanner to deflect, and enhance sensitivity; the limit structure can also free up movement space within the stroke range for the movable part of the MEMS scanner without blocking the entry and exit of light.

[0055] The magnet assembly in the electromagnetic scanning module is set corresponding to the limit structure. The limit structure can be made of magnetic conductive material, which can play a magnetic conductive function, realize the role of converging and enhancing the magnetic field, so as to ensure that the mirror has a larger deflection angle. The electromagnetic scanning module using the MEMS scanning module not only has better impact resistance and better reliability, but also can realize low power consumption drive. The electromagnetic scanning module has a simple and reliable structure and is easy to mass produce.

[0056] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or equipment. In the absence of further restrictions, the elements defined by the statement "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or equipment including the elements.

[0057] The embodiments of the present invention are described above, and these embodiments do not describe all the details in detail, nor do they limit the present invention to the specific embodiments described. Obviously, many modifications and changes can be made based on the above description. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can make good use of the present invention and the modifications based on the present invention. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A MEMS scanning module, characterized in that: include: A MEMS scanner having a frame and a mirror rotatable relative to the frame along a torsion beam; Two limiting structures, the two limiting structures are connected to the MEMS scanner from upper and lower sides of the MEMS scanner respectively; Wherein, each of the limiting structures includes two limiting units, and the two limiting units are located on the same side of the MEMS scanner, and the movable part in the MEMS scanner is limited by the two limiting structures.

2. The MEMS scanning module according to claim 1, characterized in that: The limiting unit includes a limiting frame and a limiting plate, and the limiting frame matches with at least a part of the side edge of the first frame of the MEMS scanner through a groove.

3. The MEMS scanning module according to claim 2, characterized in that: The limiting frame is L-shaped, and the limiting plate is located at the inner side of the limiting frame and connected to the limiting frame.

4. The MEMS scanning module according to claim 2, characterized in that: The MEMS scanner also includes a second frame and a third frame, the first frame is located outside the third frame, the third frame is located outside the second frame, the second frame and the third frame are respectively provided with a first coil and a second coil, the third frame is connected to the first frame via a first torsion beam arranged along a first direction, the second frame is connected to the third frame via a second torsion beam arranged along a second direction, the mirror is located in the central area of ​​the second frame, and the first direction is perpendicular to the second direction.

5. The MEMS scanning module according to claim 4, characterized in that: The two limiting structures limit the movement range of the third frame in the MEMS scanner.

6. The MEMS scanning module according to claim 5, characterized in that: The limiting plate is provided with at least one protrusion on a side facing the MEMS scanner, and the protrusion corresponds to the third frame.

7. The MEMS scanning module according to claim 6, characterized in that: The protrusions include two, and the two protrusions are symmetrically arranged along the first torsion beam.

8. The MEMS scanning module according to claim 6, characterized in that: The protrusions include at least one of a dot shape, a hemispherical shape, a truncated cone shape, a prism shape, and a rectangular parallelepiped shape.

9. The MEMS scanning module according to claim 6, characterized in that: The first coil and the second coil are staggered with the protrusion to avoid the protrusion from contacting the first coil or the second coil.

10. The MEMS scanning module according to claim 9, characterized in that: The third frame further includes a protruding structure extending outward, and the protruding structure corresponds to the position of the protrusion.

11. The MEMS scanning module according to claim 6, characterized in that: There is a preset distance between the top of the protrusion and the first frame, and the preset distance is not less than 100 microns and not more than 10 millimeters.

12. The MEMS scanning module according to claim 1, characterized in that: The limiting structure is a magnetic conductive structure, and the magnetic conductive structure includes one of iron, low carbon steel, iron-silicon alloy, iron-aluminum alloy, iron-silicon-aluminum alloy, nickel-iron alloy, iron-cobalt alloy, soft ferrite, and amorphous soft magnetic alloy.

13. An electromagnetic scanning module, characterized in that: It comprises a MEMS scanning module as described in any one of claims 1 to 12 and a magnet assembly corresponding to the MEMS scanning module, wherein the magnet assembly is located on at least one side of the MEMS scanning module to provide a magnetic field for the MEMS scanning module.

14. The electromagnetic scanning module according to claim 13, characterized in that: The magnet assembly comprises: A first magnet and a second magnet, wherein the first magnet and the second magnet are both L-shaped, the first magnet and the second magnet are arranged end to end opposite to each other, and the first magnet and the second magnet are located below the MEMS scanning module; The third magnet and the fourth magnet are both L-shaped, the third magnet and the fourth magnet are arranged end to end opposite to each other, and the third magnet and the fourth magnet are located above the MEMS scanning module.

15. The electromagnetic scanning module according to claim 13, characterized in that: The parts of the magnet assembly and the magnet assembly and the MEMS scanning module are bonded together by adhesive.

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