Micro-electromechanical system (MEMS) component and laser device

Abstract

A micro-electromechanical system (MEMS) component, comprising a MEMS chip (11) and a magnet apparatus (12). The MEMS chip (11) comprises: a movable part (111), a fixed frame (112), a cantilever (113), and a sensor (114), the movable part (111) being connected to the fixed frame (112) by means of the cantilever (113). The magnet apparatus (12) is used for generating a magnetic field, and the movable part (111) is located in the magnetic field. The sensor (114) is disposed on the movable part (111), and the sensor (114) comprises a first connection end (a), a second connection end (b), a third connection end (c) and a fourth connection end (d), which are sequentially adjacent. The first connection end (a) is connected to a first feedback signal line (s1), the third connection end (c) is connected to a second feedback signal line (s2), the first feedback signal line (s1) and the second feedback signal line (s2) are used for transmitting a feedback signal of the sensor (114), and the feedback signal is a voltage signal indicating the angle or position of the MEMS component. The first feedback signal line (s1) and the second feedback signal line (s2) are arranged along a first direction of the movable part (111). The described MEMS device reduces feedback crosstalk, and improves precision. Also provided is a laser device.

Description

Micro-electro-mechanical system (MEMS) device and laser device

[0001] The present application claims priority to the Chinese patent application No. 202410688000.9, filed on May 29, 2024, and entitled "Micro-electro-mechanical system (MEMS) device and laser device", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] Embodiments of the present application relate to the field of micro-electro-mechanical technology, and in particular to a micro-electro-mechanical system (MEMS) device and a laser device. BACKGROUND

[0003] A micro-electro-mechanical system (MEMS) device is a device manufactured by a MEMS technology.

[0004] When the MEMS device is working, the MEMS device needs to move according to a certain specific motion trajectory. At this time, the open-loop control cannot meet the working requirements of the MEMS device, and therefore the MEMS device needs to be controlled in a closed loop. To achieve the closed-loop control, the motion trajectory of the MEMS device needs to be detected. For example, to obtain and feedback the torsion angle of the MEMS device, a sensor can be integrated on the MEMS device to feedback the real-time rotation angle of the MEMS device. The sensor feeds back the detected position signal to a control circuit in real time to achieve the driving control of the MEMS device and achieve a better scanning effect.

[0005] However, when the sensor rotates with the MEMS device, an induced electromotive force is generated due to the cutting of the magnetic induction lines in the magnetic field by the loop of the signal line. The induced electromotive force is superimposed with the feedback signal of the sensor, which affects the feedback signal of the sensor, causes feedback crosstalk, and reduces the accuracy of the MEMS device. SUMMARY

[0006] Embodiments of the present application provide a micro-electro-mechanical system (MEMS) device and a laser device, which reduce feedback crosstalk and improve the accuracy of the MEMS device.

[0007] To achieve the above-mentioned purpose, embodiments of the present application adopt the following technical solutions.

[0008] In a first aspect, an embodiment of the present application provides a MEMS device, which comprises a MEMS chip and a magnet device. The MEMS chip comprises a movable component, a fixed frame, a suspension arm, and a sensor, and the movable component is connected to the fixed frame through the suspension arm. The magnet device is configured to generate a magnetic field, and the movable component is located in the magnetic field. The sensor is arranged on the movable component, and the sensor comprises a first connection end, a second connection end, a third connection end, and a fourth connection end arranged in sequence. The first connection end is connected to a first feedback signal line, and the third connection end is connected to a second feedback signal line. The first feedback signal line and the second feedback signal line are configured to transmit a feedback signal of the sensor, and the feedback signal is a voltage signal indicating an angle or a position of the MEMS device. The first feedback signal line and the second feedback signal line are arranged along a first direction of the movable component.

[0009] Therefore, compared with a mode in which the first feedback signal line and the second feedback signal line are arranged as two-side wires due to the first connection end and the third connection end being located on opposite sides, the first feedback signal line and the second feedback signal line are arranged in the same direction in the MEMS device provided by the embodiment of the present application, the movable loop formed by the first feedback signal line, the second feedback signal line, and the pivot of the movable component is reduced, the magnetic flux change when the movable component moves is further reduced, the induced electromotive force crosstalk in the feedback signal of the sensor is reduced, the feedback accuracy of the sensor is improved, and the accuracy of the MEMS device is improved.

[0010] In a possible design, the MEMS chip is a micro-mirror.

[0011] In a possible design, the MEMS chip is an inertial device. In addition, the MEMS chip can also be other devices with a movable component.

[0012] In a possible design, the first feedback signal line and the second feedback signal line are located on a side of the movable component far from the magnet device. Therefore, the first feedback signal line and the second feedback signal line are arranged at a position with weak magnetic field intensity, the magnetic flux change when the movable component moves is further reduced, the induced electromotive force crosstalk in the feedback signal of the sensor is reduced, the feedback accuracy of the sensor is improved, and the accuracy of the MEMS device is improved.

[0013] In a possible design, the distance between the first feedback signal line and the second feedback signal line is less than a preset value. Therefore, by reducing the distance between the first feedback signal line and the second feedback signal line, the magnetic field gradient difference between the first feedback signal line and the second feedback signal line is further reduced, the active part area of the loop is reduced, the magnetic flux is reduced, the induced electromotive force crosstalk in the feedback signal of the sensor is reduced, the feedback accuracy of the sensor is improved, and the accuracy of the MEMS device is improved.

[0014] In a possible design, the second connection end is connected with the first drive signal line, and the fourth connection end is connected with the second drive signal line. The first drive signal line and the second drive signal line are used to transmit a drive signal to the sensor.

[0015] In a possible design, the first drive signal line and the second drive signal line are arranged along the second direction of the movable component. The first direction and the second direction are opposite directions. In this way, the signal lines of the four connection ends of the sensor are symmetrically arranged, the induced electromotive force crosstalk in the feedback signal and the drive signal can be reduced, and the accuracy of the MEMS device can be improved.

[0016] In a possible design, the first drive signal line and the second drive signal line are arranged along the first direction of the movable component. In this way, the induced electromotive force crosstalk in the first drive signal line and the second drive signal line can be reduced, and the induced electromotive force crosstalk in the first feedback signal line and the second feedback signal line can be reduced, and the accuracy of the MEMS device can be improved.

[0017] In a possible design, the second drive signal line is arranged along the first direction of the movable component, and the first drive signal line is arranged along the third direction of the movable component. The third direction and the first direction are opposite directions.

[0018] In a possible design, the sensor is a piezoresistive sensor or a Hall sensor.

[0019] In a second aspect, an embodiment of the present application further provides a MEMS device. The MEMS device comprises a MEMS chip and a magnet device. The MEMS chip comprises a movable component, a fixed frame, a suspension arm, a first sensor, and a second sensor. The movable component is connected with the fixed frame through the suspension arm. The magnet device is used to generate a magnetic field, and the movable component is located in the magnetic field. The first sensor and the second sensor are symmetrically arranged on the movable component. A feedback signal of the MEMS chip is obtained by differentiating a feedback signal of the first sensor and a feedback signal of the second sensor. The feedback signal is a voltage signal indicating an angle or a position of the MEMS device.

[0020] In this way, in the MEMS device provided by the embodiment of the present application, the feedback signal of the first sensor and the feedback signal of the second sensor can be differentiated, the induced electromotive force crosstalk of the feedback signal of the MEMS chip can be eliminated, and the accuracy of the MEMS device can be improved.

[0021] In a possible design, the first sensor includes a first connection end, a second connection end, a third connection end and a fourth connection end which are sequentially adjacent, the first connection end is connected with the first feedback signal line, and the third connection end is connected with the second feedback signal line. The second sensor includes a fifth connection end, a sixth connection end, a seventh connection end and an eighth connection end which are sequentially adjacent, the fifth connection end is connected with the third feedback signal line, and the seventh connection end is connected with the fourth feedback signal line. The first feedback signal line and the third feedback signal line are symmetrically arranged, and the second feedback signal line and the fourth feedback signal line are symmetrically arranged. In this way, the signal lines of the first sensor and the second sensor are symmetrically arranged, the induced electromotive force cross talk in the feedback signal of the first sensor is the same as the induced electromotive force cross talk in the feedback signal of the second sensor, and the feedback signal of the MEMS chip can be eliminated by differentiating the feedback signals of the first sensor and the second sensor, thereby improving the precision of the MEMS device.

[0022] In a third aspect, the embodiments of the present application further provide a laser device, which includes a laser and the MEMS device of the first aspect or the second aspect, and the MEMS device is configured to reflect laser emitted by the laser.

[0023] In a fourth aspect, the embodiments of the present application further provide an automobile, which includes a vehicle body and the laser device of the third aspect, and the laser device is arranged on the vehicle body.

[0024] These and other aspects of the present application will become more apparent from the following description. BRIEF DESCRIPTION OF DRAWINGS

[0025] FIG. 1 is a schematic diagram of a MEMS micromirror according to an embodiment of the present application;

[0026] FIG. 2 is a structural schematic diagram of a one-dimensional MEMS micromirror according to an embodiment of the present application;

[0027] FIG. 3 is a structural schematic diagram of a two-dimensional MEMS micromirror according to an embodiment of the present application;

[0028] FIG. 4 is a structural schematic diagram of a mirror surface in a MEMS micromirror according to an embodiment of the present application;

[0029] FIG. 5 is a flowchart of a processing technology of an electromagnetic micromirror according to an embodiment of the present application;

[0030] FIG. 6 is a structural diagram of a piezoresistive sensor according to an embodiment of the present application;

[0031] FIG. 7 is a structural schematic diagram of another two-dimensional MEMS micromirror according to an embodiment of the present application;

[0032] FIG. 8 is a feedback characteristic diagram of a piezoresistive sensor according to an embodiment of the present application;

[0033] FIG. 9 is a schematic diagram of a Hall sensor according to an embodiment of the present application;

[0034] FIG. 10 is a schematic diagram of a wiring of a MEMS micromirror according to an embodiment of the present application;

[0035] FIG. 11 is a schematic diagram of a wiring of another MEMS micromirror according to an embodiment of the present application;

[0036] FIG. 12 is a magnitude diagram of feedback crosstalk according to an embodiment of the present application;

[0037] FIG. 13 is a calibration zoning diagram of a MEMS micromirror according to an embodiment of the present application;

[0038] FIG. 14 is a schematic diagram of a laser radar according to an embodiment of the present application;

[0039] FIG. 15 is a structural schematic diagram of a laser radar according to an embodiment of the present application;

[0040] FIG. 16 is a schematic diagram of a laser projection device according to an embodiment of the present application;

[0041] FIG. 17 is a structural schematic diagram of a MEMS device according to an embodiment of the present application;

[0042] FIG. 18 is a structural schematic diagram of another MEMS device according to an embodiment of the present application;

[0043] FIG. 19 is a structural schematic diagram of still another MEMS device according to an embodiment of the present application;

[0044] FIG. 20 is a structural schematic diagram of still another MEMS device according to an embodiment of the present application;

[0045] FIG. 21 is a structural schematic diagram of still another MEMS device according to an embodiment of the present application;

[0046] FIG. 22 is a structural schematic diagram of still another MEMS device according to an embodiment of the present application. DETAILED DESCRIPTION

[0047] The technical solutions in the embodiments of the present application will be described below with reference to the drawings in the embodiments of the present application. In the description of the embodiments of the present application, unless otherwise specified, " / " represents the meaning of or, for example, A / B can represent A or B; in this document, "and / or" only describes the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which means that there are three cases of A alone, A and B together, and B alone. In addition, in the description of the embodiments of the present application, "multiple" means two or more than two.

[0048] Hereinafter, the terms "first", "second", "third", etc. are used only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second", etc. can explicitly or implicitly include one or more of the features. In the description of the embodiments, the meaning of "a plurality of" is two or more, unless otherwise specified.

[0049] For the convenience of understanding, some of the example descriptions of the concepts related to the embodiments of the present application are given for reference. As shown below:

[0050] 1、Micro-electro-mechanical system (MEMS), also known as micro-electro-mechanical system, which mainly uses microelectronic technology (semiconductor manufacturing technology), through traditional semiconductor process (mainly involving micro-machining technology, mechanics and fixed acoustic wave theory, heat flow theory, electronics and biology, etc.) and materials, which integrates lithography, etching, thin film, silicon micro-machining, non-silicon micro-machining and precision machining technology, etc. to make a micro high-tech electronic mechanical device or system that integrates micro sensors, micro actuators, micro mechanical mechanisms, signal processing and control circuits, high-performance electronic integrated devices, interfaces, communication and power supply, etc. Among them, the characteristic length of MEMS device is in the range of 1 millimeter (mm) to 1 micrometer (um), and the internal key structure is generally in the order of microns or even nanometers.

[0051] 2、Resonant frequency, also known as natural frequency or natural frequency. When an object vibrates freely, its displacement changes with time according to the sine or cosine law, and the frequency of vibration is independent of the initial condition, but only related to the inherent characteristics of the object (such as mass, shape and material, etc.). The resonant frequency is called. For a simple system, the resonant frequency is: Where k is the stiffness coefficient, also known as the stiffness coefficient or stiffness coefficient. k is used to describe the size of the elastic force generated per unit deformation. When k value is larger, it means that the system needs more force to deform. m is the equivalent mass or moment of inertia of the vibrating object, which is generally related to the shape and mass of the object. For objects of the same shape, the larger the mass, the larger the equivalent mass or moment of inertia.

[0052] 3、Resonance: When a physical system is driven by an external fixed frequency, it will produce vibration. When the driving frequency of the external environment is equal to some specific frequency, the amplitude of the vibration it causes is obviously larger than that of the vibration caused by other frequencies. These specific frequencies are resonance frequencies, and this phenomenon is resonance.

[0053] At the resonant frequency, a small amount of energy can produce a large vibration, because the system stores kinetic energy. When the external resistance is very small, the resonant frequency is approximately equal to the natural frequency of the system. In general, the object resonates is harmful, resonance can cause large deformation and dynamic stress of the mechanical and structural, may cause destructive accidents.

[0054] 4、MEMS micro mirror, also known as MEMS mirror or MEMS scanning mirror, is a MEMS optical device that integrates a micro mirror and a MEMS driver together through MEMS technology. As shown in FIG. 1, (a) of FIG. 1 shows a schematic diagram of a MEMS micro mirror. For a MEMS micro mirror with a large optical deflection angle (more than 10°), its main function is to realize the pointing deflection, pattern scanning and image scanning of laser. The MEMS micro mirror with a large optical deflection angle can be called a MEMS scanning mirror to distinguish from the MEMS micro mirror with a small optical deflection angle.

[0055] (b) of FIG. 1 shows the light diagram when the MEMS micro mirror deflects. When the MEMS micro mirror does not deflect, the incident light incident on the MEMS micro mirror is the outgoing light_1. When the MEMS micro mirror deflects, the incident light incident on the MEMS micro mirror is the outgoing light_2. The angle of deflection of the outgoing light_1 and the outgoing light_2 is the optical deflection angle.

[0056] The MEMS micro mirror prepared based on micro-nano technology has the advantages of light weight, small volume and low cost. As the core device of an optical application system, it has been widely used in laser projection display, barcode scanning and self-focusing microscopes. Among them, the main structure of the MEMS micro mirror in the micro mirror is roughly the same, and the driving mode may be different. The driving mode can be electrostatic driving, electromagnetic driving, piezoelectric driving and electrothermal driving.

[0057] Further, according to the scanning dimension, the MEMS micro mirror can be divided into a single-axis micro mirror and a double-axis micro mirror. The single-axis micro mirror can scan in one dimension, also known as a one-dimensional MEMS micro mirror. The double-axis micro mirror can scan in two dimensions, also known as a two-dimensional MEMS micro mirror. The single-axis micro mirror and the double-axis micro mirror differ in structure. The single-axis micro mirror has the advantages of simple structure and process, low cost and large scanning angle. The double-axis micro mirror uses a single chip to realize two-dimensional scanning, which can reflect the advantages of MEMS technology.

[0058] As shown in FIG. 2, (a) of FIG. 2 shows a one-dimensional MEMS micro-mirror, which can include a mirror surface, a cantilever beam and an external fixed frame. (b) of FIG. 2 shows another one-dimensional MEMS micro-mirror, which can include a mirror surface, a frame, a cantilever beam and an external fixed frame. In the one-dimensional MEMS micro-mirror, the mirror surface is fixed in the frame, and the mirror surface or the frame is connected to the external fixed frame through the cantilever beam. When the cantilever beam is twisted, the mirror surface rotates relative to the external fixed frame. The cantilever beam can be a straight beam structure or a folded beam structure.

[0059] A two-dimensional MEMS micro-mirror generally includes two groups of cantilever beams. The external cantilever beam corresponds to a low-frequency torsional mode, which is referred to as a slow-axis cantilever beam. The internal cantilever beam corresponds to a high-frequency torsional mode, which is referred to as a fast-axis cantilever beam. As shown in FIG. 3, (a) of FIG. 3 shows a two-dimensional MEMS micro-mirror, which can include a mirror surface, a fast-axis cantilever beam, a gimbal, a slow-axis cantilever beam and an external fixed frame. (b) of FIG. 3 shows another two-dimensional MEMS micro-mirror, which can include a mirror surface, a frame, a fast-axis cantilever beam, a gimbal, a slow-axis cantilever beam and an external fixed frame. Specifically, the mirror surface or the frame is connected to the gimbal through the fast-axis cantilever beam, and the gimbal is connected to the external fixed frame through the slow-axis cantilever beam. When the two-dimensional MEMS micro-mirror is subjected to a force, the slow-axis cantilever beam and the fast-axis cantilever beam are twisted, and the mirror surface rotates relative to the external fixed frame in two dimensions.

[0060] In addition, according to the motion mode of the MEMS micro-mirror, the scanning mode of the MEMS micro-mirror can include a quasi-static mode and a resonant mode. Specifically, when the frequency of a driving signal is close to or equal to the resonant frequency of the MEMS micro-mirror, the MEMS micro-mirror works in a mechanical resonance state, and the MEMS micro-mirror continuously rotates periodically. The rotation period is in a sinusoidal function relationship with the driving signal frequency f, the scanning angle θ and the time t, that is, θ = Asin(2πf·t). When the MEMS micro-mirror is in the resonance state, the scanning angle is large, the driving power consumption is low, and all the MEMS micro-mirrors can work in the resonance state. When the frequency of the driving signal is far lower than the resonant frequency of the MEMS micro-mirror, the MEMS micro-mirror works in a non-resonance state, and the MEMS micro-mirror can scan or pause at any angle in the scanning range. The MEMS micro-mirror is mainly applied to laser pointing and laser vectorization pattern scanning. However, because the scanning angle range of the MEMS micro-mirror in the non-resonance state is relatively small, the required driving power consumption is much higher than that in the resonance state.

[0061] The main function of the MEMS micromirror is to realize the pointing deflection or the graphical scanning by torsion and reflection of the incident light, so the optical performance of the micromirror has a significant influence on the application effect of the micro-electro-mechanical system. The mirror surface of the MEMS micromirror usually includes a reflective layer, a mirror surface layer and a support structure, as shown in FIG. 4, which shows a schematic diagram of the structure of the mirror surface in a MEMS micromirror. The reflective layer is usually composed of a single layer or multiple layers of metal reflective film, and the commonly used materials are aluminum, silver and gold. The support structure is usually provided on the front and back surfaces of the mirror surface, and the thickness of the support structure is generally not less than that of the mirror surface. The support structure is used to strengthen the stiffness of the mirror surface and reduce the deformation of the mirror surface.

[0062] For the electromagnetic micromirror, the processing technology is as shown in FIG. 5, and the steps of the processing technology can include: (1) doping implantation on the silicon on insulator (SOI) on the insulating substrate; (2) adding a first layer of metal; (3) adding a second layer of metal; (4) front surface etching; (5) back surface etching; (6) structure release; (7) mirror surface coating. Step (1) can be used to make a piezoresistive feedback, which can be omitted.

[0063] 5. The piezoresistive sensor can include four terminals and a piezoresistive bar structure, as shown in FIG. 6. The piezoresistive bar structure is usually cross-shaped, as shown in (a) of FIG. 6, or four piezoresistive bars (such as R1, R2, R3 and R4) form a Wheatstone bridge, as shown in (b) of FIG. 6. (a) of FIG. 6 shows four ports (such as 1, 2, 3 and 4), wherein the port 1 and the port 2 are feedback terminals, and the port 3 and the port 4 are driving terminals. (b) of FIG. 6 shows a feedback power supply (VCC), a feedback positive voltage (V+), a ground (GND) and a feedback negative voltage (V-).

[0064] Specifically, taking a two-dimensional MEMS micromirror as an example, the piezoresistive sensor is arranged at the root of the suspension beam arm of the two-dimensional MEMS micromirror, as shown in FIG. 7. The piezoresistive sensor can be arranged at the root of the fast-axis suspension beam arm or the root of the slow-axis suspension beam arm. Taking the piezoresistive bar structure shown in (a) of FIG. 6 as an example, a driving voltage is applied to the port 3 and the port 4 of the piezoresistive sensor. When the suspension beam arm structure is twisted, the stress at the position of the piezoresistive bar structure changes. Due to the piezoresistive effect, the resistance of the piezoresistive bar structure changes at this time, resulting in a change in the voltage of the port 1 and the port 2.

[0065] The difference between the voltages of the port 1 and the port 2 is the feedback voltage. In an ideal case, the change of the feedback voltage and the torsion angle satisfy a linear relationship. As shown in FIG. 8, for the positive end feedback, the greater the mechanical torsion angle, the greater the amplitude of the feedback voltage; for the negative end feedback, the greater the mechanical torsion angle, the smaller the amplitude of the feedback voltage.

[0066] 6. Piezoresistive effect, i.e. when a semiconductor material is subjected to stress, the stress will cause the energy band of the semiconductor material to change and the energy valley energy to move, thereby causing the resistivity of the semiconductor material to change significantly. The relative change in resistivity can be expressed as:

[0067] In the formula, σ is the stress tensor, and π is the piezoresistive coefficient. The piezoresistive coefficient is used to represent the relative change in resistivity caused by unit stress.

[0068] If the resistance change caused by structural deformation is also considered, and the Poisson relationship of lateral deformation is introduced, the comprehensive resistivity change is:

[0069] In the formula, l is the structural characteristic size, E is the Young's modulus of the semiconductor material, ε is the structural strain, and μ is the Poisson's ratio.

[0070] For semiconductors, πE is generally tens or even hundreds of times larger than (1+2μ), so the main cause of the relative change in resistivity of the semiconductor material is the piezoresistive effect rather than the strain effect. The piezoresistive properties of single crystal silicon have high sensitivity, good dynamic response, high precision, and are easy to miniaturize and integrate, and have been widely concerned and fully developed in recent years. There are more and more MEMS components based on the piezoresistive effect of silicon.

[0071] Single crystal silicon is an anisotropic material, and its piezoresistive coefficient π is closely related to the crystal direction. According to the principle of crystal symmetry, when the piezoresistive coordinate system (i.e. the coordinate system used to represent the direction of the current of the piezoresistive element), the stress coordinate system and the unit cell coordinate system of silicon (i.e. the coordinate system in which the three axes correspond to the

[0100] ,

[0010] and

[0001] crystal directions of silicon) coincide, the matrix expression of the piezoresistive effect is:

[0072] ρ0 is the isotropic resistivity of unstressed silicon. The piezoresistive coefficient matrix is a 6x6 matrix, in which the 9 non-zero elements have only 3 independent constants π 11 , π 12 and π 44 , which are the longitudinal piezoresistive coefficient, the lateral piezoresistive coefficient and the shear piezoresistive coefficient, respectively. The longitudinal piezoresistive coefficient represents the effect of stress along a certain crystal axis on the resistance along the same crystal axis; the lateral piezoresistive coefficient represents the effect of stress along a certain crystal axis on the resistance along a certain crystal axis perpendicular to it; and the shear piezoresistive coefficient represents the effect of shear stress on a certain resistivity tensor component corresponding to it.

[0073] More generally, when the piezoresistive coordinate system, the stress coordinate system and the crystal cell coordinate system do not coincide, coordinate transformation is needed for the piezoresistive coefficient matrix and the stress tensor matrix respectively. When the coordinate axes of the Cartesian coordinate system (orthogonal coordinate system) are in any direction relative to the crystal axes, all 36 piezoresistive coefficient components in the piezoresistive coefficient matrix [π] can be nonzero.

[0074] 7. Hall effect and Hall sensor, the Hall effect is that when there is a magnetic field perpendicular to the current direction on the current-carrying conductor, the electrons in the conductor are deflected by the Lorentz force and gathered on one side of the conductor, and then a voltage (Hall voltage) is generated. The electric field generated by the Hall effect is perpendicular to the direction of the current and the magnetic field. The force of this electric field acting on the subsequent electrons can balance out the Lorentz force generated by the magnetic field, so that the subsequent electrons will not be deflected and can pass through smoothly.

[0075] Specifically, assuming that there is a current I flowing in a metal conductor, the magnetic induction intensity is B, the direction of the magnetic field is perpendicular to the direction of the current, the height and width of the metal conductor are t and w respectively, the number of free electrons in the unit volume of the conductor is n, the electric charge of the electron is e, and the average speed of the directional movement of the electron is v, then the micro definition of the current is: I = n·e·t·w·v

[0076] Due to the action of the Lorentz force, the free electrons begin to drift horizontally and gather towards the side of the metal conductor, so that the right side carries a negative charge and the left side carries a positive charge, thereby forming a potential difference. This potential difference will generate a uniform electric field in the metal conductor, which points from the positive charge to the negative charge, and is perpendicular to the direction of the current and the direction of the magnetic field, and exerts a force on the electrons, the size of which is:

[0077] As the free electrons gradually gather on the side, the potential difference between the two sides of the metal conductor gradually increases (the electric field force gradually increases), and eventually leads to the balance of the electric field force and the Lorentz force, at which time the horizontal drift of the electrons stops and no longer deviates. At this time, the voltage V H is called the Hall voltage.

[0078] In addition, the Hall voltage can also be expressed as:

[0079] Where RH is the Hall coefficient, which is determined by the intrinsic properties of the material. The Hall coefficient can be expressed as:

[0080] The sensor based on the Hall effect is called a Hall sensor. As shown in FIG. 9, which is a schematic diagram of a Hall sensor according to an embodiment of the present application, (a) in FIG. 9 is a schematic diagram of the Hall effect, (b) in FIG. 9 is a schematic diagram of a four-port Hall sensor, and (c) in FIG. 9 is a schematic diagram of another four-port Hall sensor. The Hall sensor can be used to detect the magnetic field strength, thereby inversely deducing the position information related to the Hall sensor. The four-port Hall sensor is a commonly used Hall sensor, in which port 1 and port 3 can be used to receive a driving current / voltage, and port 2 and port 4 can transmit a feedback voltage.

[0081] When the Hall sensor is integrated on the MEMS micromirror, the torsion angle of the MEMS micromirror can be fed back by cooperating with an external magnetic field.

[0082] For the widely applicable piezoresistive feedback and Hall effect, the sensor is usually designed as a four-port, that is, a driving voltage or current is applied at two opposite ports, and the voltage change of the other two opposite ports is detected, thereby obtaining the angle feedback information.

[0083] In the design of the MEMS micromirror, in order to balance the stress and the symmetric design, the wires of the four ports of the sensor arranged on the fast-axis suspension beam are respectively led out from the left and the right. As shown in FIG. 10, the positive feedback end and the negative feedback end wires experience different paths, and form a larger active loop with the rotation shaft of the movable part. If a Hall effect device is used, an external magnetic field is needed to cooperate with the Hall effect, or if a piezoresistive feedback device is used, a magneto-electric driving mode is usually used, which also has an external magnetic field. Thus, when the movable part rotates, the active part of the loop can cut the magnetic induction lines to generate an induced electromotive force, thereby affecting the feedback signal and causing feedback crosstalk.

[0084] Specifically, taking the sensor arranged on the fast-axis suspension beam of the MEMS micromirror as an example, when the slow-axis suspension beam of the MEMS micromirror rotates, the positive feedback signal line and the negative feedback signal line located on the movable part will cut the magnetic induction lines to generate an induced electromotive force. As shown in FIG. 11, assuming that the cutting speed v of the fast-axis suspension beam on the magnetic field is: L2 is the length of the positive feedback signal line or the negative feedback signal line parallel to the direction of the magnetic field, θ0 is the angle of rotation of the movable part, and w is the angular velocity. Thus, the induced electromotive force V is: V = BL1v = BL1L2θ02πf cos(wt), B is the strength of the external magnetic field, L1 is the length of the positive feedback signal line or the negative feedback signal line perpendicular to the direction of the magnetic field, and f is the driving frequency. The induced electromotive force will be superimposed on the original feedback signal of the fast-axis suspension beam, thereby causing the feedback signal of the fast-axis suspension beam to have a crosstalk signal related to the slow-axis suspension beam.

[0085] As shown in FIG. 12, (a) of FIG. 12 shows the relationship between the slow-axis driving frequency and the feedback crosstalk amplitude, and (b) of FIG. 12 shows the slow-axis feedback and the fast-axis feedback. It can be seen that the factors affecting the amplitude of crosstalk include the area of the movable loop and the rotation axis, the rotation speed (frequency) of the movable component, the rotation angle, and the strength of the external magnetic field, etc., which are irrelevant to the driving voltage size, and the induced electromotive force lags behind the phase of the slow-axis cantilever by 90°. For devices of different designs, the proportion of crosstalk is different. For MEMS micro-mirrors, the proportion of crosstalk is about 0.2% to 2%, which cannot be applied to devices with high precision requirements.

[0086] In a possible implementation, as shown in FIG. 13, a four-quadrant detector can be arranged on the back of the MEMS micro-mirror, and the MEMS micro-mirror torsion angle is calculated and deduced according to the optical feedback signal. Specifically, due to the influence of biaxial crosstalk and different angle differences, the optical feedback signal will have obvious nonlinear characteristics. Therefore, the MEMS micro-mirror can be divided into multiple regions, such as PD1, PD2, PD3, and PD4, each region is calibrated, and different coefficients are set to calculate and deduce the torsion angle.

[0087] However, in this way, a large amount of calibration work is required, and the packaging of the device also has certain requirements, and chip integration cannot be achieved.

[0088] Therefore, compared with the way of arranging the first feedback signal line and the second feedback signal line as two-side wiring because the first connection end and the third connection end are on opposite sides, the MEMS device provided in the embodiments of the present application arranges the first feedback signal line and the second feedback signal line in the same direction, reduces the movable loop formed by the first feedback signal line, the second feedback signal line, and the rotation axis of the movable component, and further reduces the magnetic flux change when the movable component moves, reduces the induced electromotive force crosstalk in the feedback signal of the sensor, improves the feedback accuracy of the sensor, and improves the accuracy of the MEMS device.

[0089] In the above scenario, the MEMS device provided in the embodiments of the present application can be applied to the fields of laser scanning, optical communication, and digital display. Among them, laser scanning is mainly used in the applications of laser radar, 3D camera, bar code scanning, laser printer, and medical imaging. Optical communication is mainly used in the applications of optical add-drop multiplexer, optical attenuator, optical switch, and optical grating. Digital display is mainly used in the applications of high-definition television, laser micro-projection, digital cinema, automotive head-up display, laser keyboard, and augmented reality (AR).

[0090] In one possible example, the MEMS device provided by the embodiments of the present application is mainly applied to a laser radar system, which is commonly used in automatic driving cars, intelligent robots, virtual reality (VR) / AR, and other intelligent systems.

[0091] The laser radar is a radar system for detecting the position and speed of a target by emitting a laser beam, and has high distance resolution, angle resolution, and speed resolution, strong anti-interference capability, and can work at all times and is not dependent on external light conditions or the radiation characteristics of the target itself.

[0092] As shown in FIG. 14, the principle of the laser radar is that the laser radar system includes a signal source and a receiving system. The laser is used as the signal source, and the laser generates and emits a pulse laser beam, which is reflected on trees, roads, bridges, and buildings on the ground to cause scattering. Part of the light wave is reflected to the receiver of the laser radar and is finally received by the receiver. The receiver accurately measures the propagation time of the light pulse from emission to reflection. Since the speed of light is known, the distance of the laser radar to the target point can be obtained according to the propagation time. As for the radial speed of the target, the Doppler shift of the reflected light can be used to determine the speed, or two or more distances can be measured, and the speed can be obtained by calculating the rate of change.

[0093] The laser radar system needs a scanning device to scan the surrounding targets by laser. The pulse laser continuously scans the target objects to obtain the data of all target points on the target objects, and the height of the laser and the scanning angle of the laser can be used to obtain the accurate three-dimensional image of the surrounding environment. Using the MEMS micromirror as the scanning micromirror of the laser radar is a mainstream way of the current solid-state laser radar, and is a main application direction of the MEMS micromirror.

[0094] The laser radar based on the MEMS micromirror has a structure as shown in FIG. 15. The signal light emitted by the laser passes through the collimator for collimation and shaping, is irradiated on the MEMS micromirror, the MEMS micromirror rapidly rotates to scan and emit the signal light to the surrounding detection targets, i.e., the scanned objects, to complete the detection of the surrounding environment. The scanning light is reflected by the target objects and is received by the receiving optical system through the receiving light path.

[0095] The MEMS micromirror is the core component of the laser radar, and its performance will directly determine the quality of the scanning projection image. Reducing the feedback crosstalk of the MEMS micromirror and improving the feedback accuracy can help to improve the scanning control accuracy of the micromirror and improve the detection resolution and accuracy. In order to meet the vehicle requirement, the micromirror is required to have high reliability and long service life, stress concentration should be avoided, and the support structure should be lightened, which helps to improve the reliability and service life of the micromirror.

[0096] In addition to the laser radar, the application scenarios of the MEMS micro-mirror also include a laser projection device, as shown in FIG. 16. The application of the laser projection device includes three lasers, i.e., a red laser, a green laser and a blue laser, which respectively emit red light, green light and blue light. The laser beams are projected onto the MEMS micro-mirror, the MEMS micro-mirror twists and scans the light beams to the screen, and the three laser tubes are synchronously modulated according to the positions of the scanned light beams to control the color of a single pixel point and generate a projection image.

[0097] The control and feedback of the micro-mirror also greatly affect the projection device. Reducing the feedback crosstalk of the MEMS micro-mirror and improving the feedback accuracy are helpful to improve the projection imaging effect.

[0098] The MEMS device provided by the embodiments of the present application is further described below.

[0099] The MEMS device 10 provided by the embodiments of the present application is shown in FIG. 17, which is a structural schematic diagram of the MEMS device provided by the embodiments of the present application. The MEMS device 10 includes a MEMS chip 11 and a magnet device 12. The MEMS chip 11 includes a movable component 111, a fixed frame 112, a suspension arm 113 and a sensor 114, and the movable component 111 is connected to the fixed frame 112 through the suspension arm 113. The magnet device 12 is used to generate a magnetic field, and the movable component 111 is located in the magnetic field. The sensor 114 is arranged on the movable component 111. The sensor 114 includes a first connection end (indicated by “a” in FIG. 17), a second connection end (indicated by “b” in FIG. 17), a third connection end (indicated by “c” in FIG. 17) and a fourth connection end (indicated by “d” in FIG. 17) which are sequentially adjacent. The first connection end is connected to a first feedback signal line (indicated by s1 in FIG. 17), and the third connection end is connected to a second feedback signal line (indicated by s2 in FIG. 17). The first feedback signal line and the second feedback signal line are used to transmit a feedback signal of the sensor 114. The feedback signal is a voltage signal indicating the angle or position of the MEMS device 10. The first feedback signal line and the second feedback signal line are arranged along a first direction of the movable component 111.

[0100] For example, the MEMS chip 11 can be a micro-mirror. For example, the MEMS chip 11 can be a one-dimensional MEMS micro-mirror, and the MEMS chip 11 can also be a two-dimensional MEMS micro-mirror. When the MEMS chip 11 is a one-dimensional MEMS micro-mirror, the movable component 111 is a MEMS micro-mirror. When the MEMS chip 11 is a two-dimensional MEMS micro-mirror, the movable component 111 can include a MEMS micro-mirror, a first movable frame and a second movable frame. The first movable frame can be understood as the fast-axis suspension beam described in FIG. 3, and the second movable frame can be understood as the gimbal described in FIG. 3.

[0101] For example, the MEMS chip 11 can also be an inertial device, such as a gyroscope or an accelerometer. In addition, the MEMS chip can also be other devices with movable structures.

[0102] For example, the magnet device 12 can include a plurality of magnets, and the magnet device shown in FIG. 17 is only an example. In one possible example, one magnet can be arranged in each direction of the fixed frame 112. In one possible example, an L-shaped magnet can also be arranged in any two adjacent directions of the fixed frame 112.

[0103] For example, the sensor 114 can be a piezoresistive sensor as shown in FIG. 6 or a Hall sensor as shown in FIG. 9. For the Hall sensor, there is no limitation on electromagnetic driving, and the principles of the piezoresistive sensor and the Hall sensor will not be described here. The sensor 114 can transmit a feedback signal, which can be a voltage signal, and the MEMS device 10 can obtain the torsion angle or position of the MEMS chip 11 based on the feedback signal of the sensor 114.

[0104] For example, taking a two-dimensional coordinate system as an example, assuming that the direction of the magnetic field is the y direction, the first direction can be the x direction. The first direction can also be understood as a path, that is, the first feedback signal line and the second feedback signal line are arranged along the same path.

[0105] Therefore, compared with the mode in which the first feedback signal line and the second feedback signal line are arranged as two-side wiring due to the fact that the first connection end and the third connection end are located on opposite sides, the MEMS device 10 provided in the embodiment of the present application arranges the first feedback signal line and the second feedback signal line in the same direction, reduces the active loop formed by the first feedback signal line, the second feedback signal line, and the rotation shaft of the movable component 111, and further reduces the magnetic flux change when the movable component 111 moves, reduces the induced electromotive force crosstalk in the feedback signal of the sensor 114, improves the feedback accuracy of the sensor 114, and improves the accuracy of the MEMS device 10.

[0106] Optionally, as shown in FIG. 18, the first feedback signal line and the second feedback signal line are located on the side of the movable component 111 away from the magnet device 12.

[0107] That is, the first feedback signal line and the second feedback signal line are arranged at a position with weak magnetic field strength, which can further reduce the magnetic flux change when the movable component 111 moves, reduce the induced electromotive force crosstalk in the feedback signal of the sensor 114, improve the feedback accuracy of the sensor 114, and improve the accuracy of the MEMS device 10.

[0108] Optionally, the distance between the first feedback signal line and the second feedback signal line is less than a preset value.

[0109] For example, the preset value can be 1mm, 500um, 300um or 200um.

[0110] For example, by reducing the distance between the first feedback signal line and the second feedback signal line, the active loop formed by the first feedback signal line, the second feedback signal line and the rotation shaft of the movable component 111 is reduced. Thus, the magnetic field gradient difference of the first feedback signal line and the second feedback signal line can be further reduced, while the active part area of the loop is reduced, the magnetic flux is reduced, the induced electromotive force crosstalk in the feedback signal of the sensor 114 is reduced, the feedback accuracy of the sensor 114 is improved, and the accuracy of the MEMS device 10 is improved.

[0111] Optionally, as shown in FIG. 19, the sensor 114 includes a first connection end (indicated as "a" in FIG. 19), a second connection end (indicated as "b" in FIG. 19), a third connection end (indicated as "c" in FIG. 19) and a fourth connection end (indicated as "d" in FIG. 19) in sequence. The second connection end is connected with the first drive signal line (indicated as s3 in FIG. 19), and the fourth connection end is connected with the second drive signal line (indicated as s4 in FIG. 19). The first drive signal line and the second drive signal line are used to transmit a drive signal to the sensor 114. In one possible example, the first connection end a, the second connection end b, the third connection end c and the fourth connection end d are adjacent in sequence in a clockwise direction.

[0112] The first drive signal line and the second drive signal line are arranged along the second direction of the movable component 111, and the first direction and the second direction are opposite directions.

[0113] For example, the second feedback signal line and the second drive signal line can realize the arrangement of the second feedback signal line along the first direction and the arrangement of the second drive signal line along the second direction through a jumper. Thus, since the first drive signal line and the second drive signal line are arranged along the same direction, the induced electromotive force crosstalk in the drive signal can be reduced, and the accuracy of the MEMS device 10 is improved.

[0114] Thus, the signal lines of the four connection ends of the sensor 114 are arranged symmetrically, the first feedback signal line and the second feedback signal line are arranged along the same direction, and the first drive signal line and the second drive signal line are arranged along the same direction. The induced electromotive force crosstalk in the feedback signal and the drive signal can be reduced, and the accuracy of the MEMS device 10 is improved.

[0115] Optionally, the first drive signal line and the second drive signal line are arranged along the first direction of the movable component 111.

[0116] Exemplarily, the first driving signal line and the second driving signal line can also be arranged along the first direction of the movable component 111, i.e., the first feedback signal line, the second feedback signal line, the first driving signal line and the second driving signal line are all arranged along the same direction. In this way, the induced electromotive force crosstalk in the first feedback signal line and the second feedback signal line can be reduced, and the precision of the MEMS device 10 can be improved.

[0117] Optionally, as shown in FIG. 20, the second driving signal line is arranged along the first direction of the movable component 111, and the first driving signal line is arranged along the third direction of the movable component 111, the third direction being opposite to the first direction.

[0118] Exemplarily, the first feedback signal line, the second feedback signal line and the second driving signal line are arranged along the same direction, and the first driving signal line is arranged along another direction. In this way, the induced electromotive force crosstalk in the first feedback signal line and the second feedback signal line can still be reduced, and the precision of the MEMS device 10 can be improved.

[0119] In this way, taking L1=10mm and L2=5mm as an example, after the first feedback signal line and the second feedback signal line are arranged along the same direction, L1*L2 in the calculation formula of the induced electromotive force becomes 5mm*0.2mm, i.e., the induced electromotive force is reduced by about 50 times. In addition, taking 1% crosstalk as an example, the crosstalk of the MEMS device provided in the embodiments of the present application can be reduced to 0.2‰. For a 30° scanning angle, the resolution accuracy of the MEMS device provided in the embodiments of the present application can be reduced from 0.3 degrees to 6 millidegrees, which can meet the needs of some precise application scenarios (e.g., 0.01°-0.05°).

[0120] The embodiments of the present application also provide a MEMS device 20, as shown in FIG. 21, which comprises a MEMS chip 21 and a magnet device 22. The MEMS chip 21 comprises a movable component 211, a fixed frame 212, a suspension arm 213, a first sensor 214 and a second sensor 215, and the movable component 211 is connected through the suspension arm 213 and the fixed frame 212. The magnet device 22 is used to generate a magnetic field, and the movable component 211 is located in the magnetic field. The first sensor 214 and the second sensor 215 are symmetrically arranged on the movable component 211, wherein the feedback signal of the MEMS chip 21 is obtained by differentially processing the feedback signal of the first sensor 214 and the feedback signal of the second sensor 215, and the feedback signal is a voltage signal indicating the angle or position of the MEMS device 20.

[0121] Exemplarily, the first sensor 214 and the second sensor 215 can be the piezoresistive sensor shown in FIG. 6, or the Hall sensor shown in FIG. 9, and for the Hall sensor, the electromagnetic drive is not limited. One of the first sensor 214 and the second sensor 215 can be understood as a backup, and the structures of the first sensor 214 and the second sensor 215 can be the same.

[0122] For the sensor, the feedback signal and the drive signal can satisfy the following relationship: V out (V drive , θ) = V crosstalk (θ, B, f) + V drive ·k·θ, wherein Vout is the feedback signal, Vdrive is the drive signal, Vcrosstalk is the crosstalk signal, θ is the angle of the MEMS chip offset, B is the magnetic field strength, f is the torsion frequency, and k is the sensor coefficient.

[0123] Therefore, for the first sensor 214 and the second sensor 215, the calculation formula of the angle of the MEMS chip 21 offset can be represented as: Vdrive1 is the drive signal of the first sensor, Vdrive2 is the drive signal of the second sensor, Vout(Vdrive1, θ) is the feedback signal of the first sensor, and Vout(Vdrive2, θ) is the feedback signal of the second sensor.

[0124] It can be seen that the difference between the feedback signal of the first sensor 214 and the feedback signal of the second sensor 215 can eliminate the crosstalk of the feedback signal of the MEMS chip 21 and improve the accuracy of the MEMS device 20.

[0125] In addition, as shown in FIG. 22, another magnet device 22 is shown in FIG. 22. The position and shape of the magnet device 22 can be set as required, and the position and shape of the magnet device 22 are not limited in the embodiments of the application.

[0126] Optionally, the first sensor 214 includes a first connection end, a second connection end, a third connection end and a fourth connection end which are sequentially adjacent, the first connection end is connected with the first feedback signal line, and the third connection end is connected with the second feedback signal line. The second sensor 215 includes a fifth connection end, a sixth connection end, a seventh connection end and an eighth connection end which are sequentially adjacent, the fifth connection end is connected with the third feedback signal line, and the seventh connection end is connected with the fourth feedback signal line. The first feedback signal line and the third feedback signal line are symmetrically arranged, and the second feedback signal line and the fourth feedback signal line are symmetrically arranged.

[0127] For example, the signal lines of the first sensor 214 and the second sensor 215 are symmetrically arranged, and thus the induced electromotive force cross talk in the feedback signal of the first sensor 214 and the induced electromotive force cross talk in the feedback signal of the second sensor 215 are the same when the movable component 211 moves. Thus, the feedback signal of the first sensor 214 and the feedback signal of the second sensor 215 can be differentially processed, that is, the induced electromotive force cross talk of the feedback signal of the MEMS chip 21 can be eliminated, and the precision of the MEMS device is improved.

[0128] In addition, the second connection end of the first sensor 214 is connected with the first driving signal line, the fourth connection end of the first sensor 214 is connected with the second driving signal line, and the first driving signal line and the second driving signal line are used for transmitting a driving signal to the first sensor 214. The sixth connection end of the second sensor 215 is connected with the third driving signal line, the eighth connection end of the second sensor 215 is connected with the fourth driving signal line, and the third driving signal line and the fourth driving signal line are used for transmitting a driving signal to the second sensor 215. The first driving signal line and the third driving signal line are symmetrically arranged, and the second driving signal line and the fourth driving signal line are symmetrically arranged.

[0129] In a possible implementation, the first feedback signal line and the second feedback signal line of the first sensor 214 are arranged along a first direction, the first driving signal line and the second driving signal line of the first sensor 214 are arranged along a second direction, and the first direction and the second direction are opposite directions. The third feedback signal line and the fourth feedback signal line of the second sensor 214 are arranged along the first direction, and the third driving signal line and the fourth driving signal line of the second sensor 215 are arranged along the second direction.

[0130] In another possible implementation, the first feedback signal line and the first driving signal line of the first sensor 214 are arranged along a first direction, and the second feedback signal line and the second driving signal line of the first sensor 214 are arranged along a second direction. The third feedback signal line and the third driving signal line of the second sensor 215 are arranged along the first direction, and the fourth feedback signal line and the fourth driving signal line of the second sensor 215 are arranged along the second direction.

[0131] In yet another possible implementation, the first feedback signal line, the second feedback signal line, the first driving signal line and the second driving signal line of the first sensor 214 are arranged along a first direction or a second direction. The third feedback signal line, the fourth feedback signal line, the third driving signal line and the fourth driving signal line of the second sensor 215 are arranged along the first direction or the second direction.

[0132] That is, the feedback signal lines of the first sensor 214 and the second sensor 215 are symmetrically arranged, and the driving signal lines of the first sensor 214 and the second sensor 215 are symmetrically arranged.

[0133] The embodiment of the present application also provides a laser device, which comprises a laser and the MEMS device described above, and the MEMS device is used for reflecting the laser emitted by the laser.

[0134] Through the description of the above embodiments, those skilled in the art can understand that, for the convenience and brevity of description, only the division of the above functional modules is taken as an example for illustration, and in actual application, the above functions can be completed by different functional modules according to needs, that is, the internal structure of the device is divided into different functional modules to complete all or part of the functions described above.

[0135] In several embodiments provided in the present application, it should be understood that the disclosed apparatus and method can be implemented by other ways. For example, the apparatus embodiment described above is only schematic, for example, the division of the modules or units is only a logical function division, and actual implementation can have another division manner, for example, a plurality of units or components can be combined or integrated into another device, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the units or components shown or discussed can be indirect coupling or communication connection through some interface, device or unit, and can be electrical, mechanical or other forms.

[0136] The units described as separate components can or can not be physically separate, and the components shown as units can be one physical unit or multiple physical units, that is, can be located in one place, or can be distributed to multiple different places. Part or all of the units can be selected according to actual needs to achieve the purpose of the embodiment scheme.

[0137] In addition, each functional unit in each embodiment of the present application can be integrated in one processing unit, or each unit can exist physically, or two or more units can be integrated in one unit. The integrated unit can be realized in the form of hardware or in the form of software functional unit.

[0138] The integrated unit, if implemented in the form of a software function unit and sold or used as an independent product, can be stored in a readable storage medium. Based on such understanding, the technical solutions of the embodiments of the present application essentially or say the part that contributes to the prior art or the whole or part of the technical solutions can be embodied in the form of a software product. The software product is stored in a storage medium, including a plurality of instructions to make a device (which can be a single-chip microcomputer, a chip, etc.) or a processor execute all or part of the steps of the method described in various embodiments of the present application. The aforementioned storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and various media that can store program codes.

[0139] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of changes or replacements within the technical scope disclosed in the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A microelectromechanical system, MEMS, device, characterized by The MEMS chip and the magnet device are included. The MEMS chip includes a movable component, a fixed frame, a suspension arm, and a sensor, and the movable component is connected through the suspension arm and the fixed frame. The magnet device is used to generate a magnetic field, and the movable component is located in the magnetic field. The sensor is arranged on the movable component, and the sensor includes first, second, third, and fourth connection ends arranged in sequence, the first connection end is connected with a first feedback signal line, the third connection end is connected with a second feedback signal line, the first and second feedback signal lines are used to transmit a feedback signal of the sensor, and the feedback signal is a voltage signal indicating an angle or a position of the MEMS device. The first and second feedback signal lines are arranged along a first direction of the movable component. The MEMS chip is a micro-mirror.

2. The MEMS device of claim 1, wherein, The MEMS chip is an inertial device.

3. The MEMS device of claim 1, wherein, The first and second feedback signal lines are located on a side of the movable component far from the magnet device.

4. The MEMS device of any of claims 1-3, wherein, The first and second feedback signal lines have a spacing less than a preset value.

5. The MEMS device according to any one of claims 1-4, characterized in that, 6. The MEMS device according to any one of claims 1-5, wherein The second connection end is connected with a first driving signal line, and the fourth connection end is connected with a second driving signal line, and the first and second driving signal lines are used to transmit a driving signal to the sensor. The first and second driving signal lines are arranged along a second direction of the movable component, and the first and second directions are opposite directions.

7. The MEMS device of claim 6, wherein, The first and second driving signal lines are arranged along the first direction of the movable component.

8. The MEMS device of claim 6, wherein, The second driving signal line is arranged along the first direction of the movable component, and the first driving signal line is arranged along a third direction of the movable component, and the third and first directions are opposite directions.

9. The MEMS device of claim 6, wherein, The sensor is a piezoresistive sensor or a Hall sensor.

10. The MEMS device of any of claims 1-9, wherein, The MEMS chip and the magnet device are included.

11. A MEMS device, characterized by The MEMS chip includes a movable component, a fixed frame, a suspension arm, a first sensor, and a second sensor, and the movable component is connected through the suspension arm and the fixed frame. The magnet device is used to generate a magnetic field, and the movable component is located in the magnetic field. The first and second sensors are symmetrically arranged on the movable component. The feedback signal of the MEMS chip is obtained by differentially processing a feedback signal of the first sensor and a feedback signal of the second sensor, and the feedback signal is a voltage signal indicating an angle or a position of the MEMS device. The first sensor includes first, second, third, and fourth connection ends arranged in sequence, the first connection end is connected with a first feedback signal line, and the third connection end is connected with a second feedback signal line. ​ 12. The MEMS device of claim 11, wherein, ​ The second sensor comprises a fifth connecting end, a sixth connecting end, a seventh connecting end and an eighth connecting end which are sequentially adjacent, the fifth connecting end is connected with the third feedback signal line, and the seventh connecting end is connected with the fourth feedback signal line. The first feedback signal line and the third feedback signal line are symmetrically arranged, and the second feedback signal line and the fourth feedback signal line are symmetrically arranged.

13. A laser apparatus, characterized by comprising: A MEMS device as claimed in any of claims 1-10 or as claimed in claim 11 or 12; The MEMS device is used for reflecting laser emitted by the laser.

Images