MEMS micromirror-IMU integration technology

Abstract

The invention relates to the technical field of light beam control, in particular to an MEMS micromirror-IMU (Inertial Measurement Unit) integration technology. The invention relates to an MEMS micromirror-IMU integrated system, which comprises a substrate, an inertial measurement unit, a micromirror array and a control chip are integrated on the upper surface of the substrate; the inertial measurement unit comprises an accelerometer chip and a gyroscope chip; the micro-mirror array comprises a packaging shell which is of a cup-shaped structure, and a cup opening of the packaging shell faces upwards; an MEMS micromirror A is mounted on the inner bottom surface of the packaging shell; the inner side surface of the packaging shell is provided with an even number of more than or equal to four MEMS micromirrors B; the input end of the control chip is electrically connected with the output end of the accelerometer chip and the output end of the gyroscope chip respectively; the output end of the control chip is electrically connected with the control end of the MEMS micromirror A and the control end of each MEMS micromirror B. The invention solves the problems of small scanning field angle, slow compensation speed and low compensation precision of the existing beam control technology, and is suitable for the fields of laser radar, free space optical communication, portable projection, imaging stability and the like.

Description

Technical Field

[0001] This invention relates to the field of beam control technology, specifically a MEMS micromirror-IMU integration technology. Background Technology

[0002] Beam control technology is a core technology widely used in lidar, free-space optical communication, portable projection, and image stabilization, achieving various optical applications by controlling the direction of a beam in inertial space. However, in practical applications, existing beam control technologies suffer from the following problems due to their inherent principles: First, existing beam control technologies generally rely on a single MEMS micromirror for beam scanning, and the scanning field of view depends on the deflection angle of that single MEMS micromirror. However, considering that an excessively large deflection angle of a single MEMS micromirror would significantly reduce its resonant frequency, scanning linearity, and control accuracy, the deflection angle of a single MEMS micromirror is usually limited to a small range, resulting in a small scanning field of view. Second, existing beam control technologies generally rely on a gimbaled stabilization platform to compensate for beam pointing deviations. However, since the compensation method of the gimbaled stabilization platform is passive, the compensation speed is slow and the compensation accuracy is low. Therefore, it is necessary to invent a MEMS micromirror-IMU integrated technology to solve the problems of small scanning field of view, slow compensation speed, and low compensation accuracy in existing beam control technologies. Summary of the Invention

[0003] To address the problems of small scanning field of view, slow compensation speed, and low compensation accuracy in existing beam control technologies, this invention provides a MEMS micromirror-IMU integrated technology.

[0004] This invention is achieved using the following technical solution: A MEMS micromirror-IMU integrated system includes a substrate; an inertial measurement unit, a micromirror array, and a control chip are integrated on the upper surface of the substrate. The inertial measurement unit includes an accelerometer chip and a gyroscope chip; The micromirror array includes a cup-shaped encapsulation housing with the cup opening facing upwards; a MEMS micromirror A is mounted on the inner bottom surface of the encapsulation housing; an even number of MEMS micromirrors B, greater than or equal to four, are mounted on the inner side surface of the encapsulation housing, and each MEMS micromirror B is arranged at equal intervals along the circumference. The input terminal of the control chip is electrically connected to the output terminal of the accelerometer chip and the output terminal of the gyroscope chip, respectively; the output terminal of the control chip is electrically connected to the control terminal of MEMS micromirror A and the control terminal of each MEMS micromirror B, respectively.

[0005] A MEMS micromirror-IMU integrated beam control method, which is based on the MEMS micromirror-IMU integrated system described in this invention, includes the following steps: First, the substrate is fixed on the carrier, and a light source is placed directly above the packaging shell; Then, the light source is activated, and the light beam emitted by the light source is incident perpendicularly on the mirror surface of MEMS micromirror A, and is reflected perpendicularly by the mirror surface of MEMS micromirror A. Then, the control chip generates a drive control signal and sends the drive control signal to MEMS micromirror A and each MEMS micromirror B, thereby causing the mirror surface of MEMS micromirror A and each MEMS micromirror B to deflect. At this time, the light beam emitted by the light source is obliquely incident on the mirror surface of MEMS micromirror A, and after being obliquely reflected by the mirror surface of MEMS micromirror A, it is obliquely incident on the mirror surface of MEMS micromirror B, and then after being obliquely reflected by the mirror surface of MEMS micromirror B, the beam is scanned. During this process, the inertial measurement unit and control chip compensate for beam pointing deviations, ensuring that the beam's direction remains unchanged in inertial space; specifically including: a. Rotation Compensation Mode: When the carrier rotates due to attitude changes, the beam direction deviates at an angle. The gyroscope chip detects the angular velocity of the carrier in real time and sends the detection result to the control chip. The control chip calculates the rotation angle of the carrier based on the detection result and generates a compensation control signal based on the rotation angle. The compensation control signal is then sent to MEMS micromirror A and each MEMS micromirror B, thereby causing the mirror surface of MEMS micromirror A and the mirror surface of each MEMS micromirror B to rotate in opposite directions around the corresponding axis by the same angle, thus compensating for the angle deviation of the beam direction and keeping the beam direction unchanged in inertial space. b. Translation Compensation Mode: When the carrier translates due to vibration, the beam direction deviates. The accelerometer chip detects the carrier's acceleration in real time and sends the detection result to the control chip. The control chip calculates the translation distance of the carrier based on the detection result and generates a compensation control signal based on the translation distance. The compensation control signal is then sent to MEMS micromirror A and each MEMS micromirror B, thereby causing the mirror surface of MEMS micromirror A and each MEMS micromirror B to translate in the opposite direction along the corresponding axis by the same distance, thus compensating for the positional deviation of the beam direction and ensuring that the beam direction remains unchanged in inertial space.

[0006] Compared with existing beam control technologies, this invention achieves large field-of-view beam scanning and rapid, high-precision compensation for beam pointing deviations by three-dimensional heterogeneous integration of a micromirror array and an inertial measurement unit (IMU). This provides the following advantages: First, this invention no longer relies on a single MEMS micromirror for beam scanning, but rather on a micromirror array. Therefore, the scanning field of view no longer depends on the deflection angle of a single MEMS micromirror, but is determined by the deflection angles of all MEMS micromirrors in the array. Based on this, even if the deflection angle of a single MEMS micromirror is limited to a small range, a large scanning field of view can still be obtained. Second, this invention no longer relies on a gimbaled stabilization platform for beam pointing deviation compensation, but rather on the inertial measurement unit and control chip. Since the compensation method of the inertial measurement unit and control chip is active compensation, the compensation speed is faster and the compensation accuracy is higher.

[0007] This invention effectively solves the problems of small scanning field of view, slow compensation speed and low compensation accuracy in existing beam control technology, and is applicable to fields such as lidar, free space optical communication, portable projection and imaging stabilization. Attached Figure Description

[0008] Figure 1 This is a schematic diagram of the first structure of the present invention.

[0009] Figure 2 yes Figure 1 Top view.

[0010] Figure 3 This is a schematic diagram of the second structure of the present invention.

[0011] Figure 4 yes Figure 3 Top view.

[0012] Figure 5 This is a schematic diagram of the micromirror array in this invention.

[0013] Figure 6 yes Figure 5 AA sectional view.

[0014] Figure 7 This is a schematic diagram of the encapsulation shell structure in this invention.

[0015] Figure 8 yes Figure 7 BB cross-sectional view.

[0016] In the diagram: 1-substrate, 201-accelerometer chip, 202-gyroscope chip, 301-package housing, 302-MEMS micromirror A, 303-MEMS micromirror B, 4-control chip. Detailed Implementation Example 1

[0017] A MEMS micromirror-IMU integrated system includes a substrate 1; an inertial measurement unit, a micromirror array, and a control chip 4 are integrated on the upper surface of the substrate 1. The inertial measurement unit includes an accelerometer chip 201 and a gyroscope chip 202; The micromirror array includes a cup-shaped encapsulation housing 301 with the cup opening facing upwards; a MEMS micromirror A302 is mounted on the inner bottom surface of the encapsulation housing 301; an even number of MEMS micromirrors B303, greater than or equal to four, are mounted on the inner side surface of the encapsulation housing 301, and each MEMS micromirror B303 is arranged at equal intervals along the circumference. The input terminal of the control chip 4 is electrically connected to the output terminal of the accelerometer chip 201 and the output terminal of the gyroscope chip 202, respectively; the output terminal of the control chip 4 is electrically connected to the control terminal of the MEMS micromirror A302 and the control terminal of each MEMS micromirror B303, respectively.

[0018] like Figure 1 , Figure 2 As shown, in this embodiment, the accelerometer chip 201, the gyroscope chip 202, and the package housing 301 are stacked and fixed together from bottom to top; the lower surface of the accelerometer chip 201 and the lower surface of the control chip 4 are both fixed to the upper surface of the substrate 1.

[0019] The accelerometer chip 201 is a MEMS three-axis accelerometer chip; the gyroscope chip 202 is a MEMS three-axis gyroscope chip.

[0020] The encapsulation housing 301 has a prismatic cup-shaped structure; the MEMS micromirror A302 and MEMS micromirror B303 are both electrostatically driven MEMS micromirrors with five degrees of freedom.

[0021] The control chip 4 is an ASIC control chip.

[0022] A MEMS micromirror-IMU integrated beam control method, which is based on the MEMS micromirror-IMU integrated system described in this invention, includes the following steps: First, the substrate 1 is fixed on the carrier, and a light source is placed directly above the encapsulation housing 301; Then, the light source is activated, and the light beam emitted by the light source is incident perpendicularly on the mirror surface of the MEMS micromirror A302 and is reflected perpendicularly by the mirror surface of the MEMS micromirror A302. Then, the control chip 4 generates a drive control signal and sends the drive control signal to the MEMS micromirror A302 and each MEMS micromirror B303, thereby causing the mirror surfaces of MEMS micromirror A302 and each MEMS micromirror B303 to deflect. At this time, the light beam emitted by the light source is obliquely incident on the mirror surface of MEMS micromirror A302, and after being obliquely reflected by the mirror surface of MEMS micromirror A302, it is obliquely incident on the mirror surface of MEMS micromirror B303, and then after being obliquely reflected by the mirror surface of MEMS micromirror B303, the beam is scanned. During this process, the inertial measurement unit and control chip 4 compensate for the beam pointing deviation, ensuring that the beam's direction remains unchanged in inertial space; specifically including: a. Rotation Compensation Mode: When the carrier rotates due to attitude changes, the beam direction deviates at an angle; the gyroscope chip 202 detects the angular velocity of the carrier in real time and sends the detection result to the control chip 4; the control chip 4 calculates the rotation angle of the carrier based on the detection result, generates a compensation control signal based on the rotation angle of the carrier, and then sends the compensation control signal to the MEMS micromirror A302 and each MEMS micromirror B303, thereby causing the mirror surface of MEMS micromirror A302 and the mirror surface of each MEMS micromirror B303 to rotate in the opposite direction around the corresponding axis by the same angle, thereby compensating for the angle deviation of the beam direction, and thus making the beam direction remain unchanged in inertial space; b. Translation Compensation Mode: When the carrier translates due to vibration, the beam direction deviates. The accelerometer chip 201 detects the acceleration of the carrier in real time and sends the detection result to the control chip 4. The control chip 4 calculates the translation distance of the carrier based on the detection result and generates a compensation control signal based on the translation distance. The compensation control signal is then sent to the MEMS micromirror A302 and each MEMS micromirror B303, thereby causing the mirror surface of MEMS micromirror A302 and the mirror surface of each MEMS micromirror B303 to translate in the opposite direction along the corresponding axis by the same distance, thereby compensating for the positional deviation of the beam direction and ensuring that the beam direction remains unchanged in inertial space.

[0023] In specific implementation, the accelerometer chip 201, gyroscope chip 202, and package housing 301 are stacked and fixed together from bottom to top using a three-dimensional integration process. The lower surfaces of the accelerometer chip 201 and the control chip 4 are both fixed to the upper surface of the substrate 1 using a three-dimensional integration process. The input terminal of the control chip 4 is electrically connected to the output terminals of the accelerometer chip 201 and the gyroscope chip 202 respectively using a three-dimensional integration process. The output terminal of the control chip 4 is electrically connected to the control terminal of the MEMS micromirror A302 and the control terminals of each MEMS micromirror B303 respectively using a three-dimensional integration process. The three-dimensional integration process includes, but is not limited to, one or more of the following: through-silicon via (TSV), through-glass via (TGV), microbumps, wafer bonding, and chip bonding. Example 2

[0024] A MEMS micromirror-IMU integrated system includes a substrate 1; an inertial measurement unit, a micromirror array, and a control chip 4 are integrated on the upper surface of the substrate 1. The inertial measurement unit includes an accelerometer chip 201 and a gyroscope chip 202; The micromirror array includes a cup-shaped encapsulation housing 301 with the cup opening facing upwards; a MEMS micromirror A302 is mounted on the inner bottom surface of the encapsulation housing 301; an even number of MEMS micromirrors B303, greater than or equal to four, are mounted on the inner side surface of the encapsulation housing 301, and each MEMS micromirror B303 is arranged at equal intervals along the circumference. The input terminal of the control chip 4 is electrically connected to the output terminal of the accelerometer chip 201 and the output terminal of the gyroscope chip 202, respectively; the output terminal of the control chip 4 is electrically connected to the control terminal of the MEMS micromirror A302 and the control terminal of each MEMS micromirror B303, respectively.

[0025] like Figure 3 , Figure 4 As shown, in this embodiment, the lower surface of the accelerometer chip 201, the lower surface of the gyroscope chip 202, the outer bottom surface of the package housing 301, and the lower surface of the control chip 4 are all fixed to the upper surface of the substrate 1.

[0026] The accelerometer chip 201 is a MEMS three-axis accelerometer chip; the gyroscope chip 202 is a MEMS three-axis gyroscope chip.

[0027] The encapsulation housing 301 has a prismatic cup-shaped structure; the MEMS micromirror A302 and MEMS micromirror B303 are both electrostatically driven MEMS micromirrors with five degrees of freedom.

[0028] The control chip 4 is an ASIC control chip.

[0029] A MEMS micromirror-IMU integrated beam control method, which is based on the MEMS micromirror-IMU integrated system described in this invention, includes the following steps: First, the substrate 1 is fixed on the carrier, and a light source is placed directly above the encapsulation housing 301; Then, the light source is activated, and the light beam emitted by the light source is incident perpendicularly on the mirror surface of the MEMS micromirror A302 and is reflected perpendicularly by the mirror surface of the MEMS micromirror A302. Then, the control chip 4 generates a drive control signal and sends the drive control signal to the MEMS micromirror A302 and each MEMS micromirror B303, thereby causing the mirror surfaces of MEMS micromirror A302 and each MEMS micromirror B303 to deflect. At this time, the light beam emitted by the light source is obliquely incident on the mirror surface of MEMS micromirror A302, and after being obliquely reflected by the mirror surface of MEMS micromirror A302, it is obliquely incident on the mirror surface of MEMS micromirror B303, and then after being obliquely reflected by the mirror surface of MEMS micromirror B303, the beam is scanned. During this process, the inertial measurement unit and control chip 4 compensate for the beam pointing deviation, ensuring that the beam's direction remains unchanged in inertial space; specifically including: a. Rotation Compensation Mode: When the carrier rotates due to attitude changes, the beam direction deviates at an angle; the gyroscope chip 202 detects the angular velocity of the carrier in real time and sends the detection result to the control chip 4; the control chip 4 calculates the rotation angle of the carrier based on the detection result, generates a compensation control signal based on the rotation angle of the carrier, and then sends the compensation control signal to the MEMS micromirror A302 and each MEMS micromirror B303, thereby causing the mirror surface of MEMS micromirror A302 and the mirror surface of each MEMS micromirror B303 to rotate in the opposite direction around the corresponding axis by the same angle, thereby compensating for the angle deviation of the beam direction, and thus making the beam direction remain unchanged in inertial space; b. Translation Compensation Mode: When the carrier translates due to vibration, the beam direction deviates. The accelerometer chip 201 detects the acceleration of the carrier in real time and sends the detection result to the control chip 4. The control chip 4 calculates the translation distance of the carrier based on the detection result and generates a compensation control signal based on the translation distance. The compensation control signal is then sent to the MEMS micromirror A302 and each MEMS micromirror B303, thereby causing the mirror surface of MEMS micromirror A302 and the mirror surface of each MEMS micromirror B303 to translate in the opposite direction along the corresponding axis by the same distance, thereby compensating for the positional deviation of the beam direction and ensuring that the beam direction remains unchanged in inertial space.

[0030] In specific implementation, the lower surfaces of the accelerometer chip 201, the gyroscope chip 202, the outer bottom surface of the package housing 301, and the lower surface of the control chip 4 are all fixed to the upper surface of the substrate 1 using a three-dimensional integration process. The input terminal of the control chip 4 is electrically connected to the output terminals of the accelerometer chip 201 and the gyroscope chip 202 respectively using a three-dimensional integration process; the output terminal of the control chip 4 is electrically connected to the control terminal of the MEMS micromirror A302 and the control terminals of each MEMS micromirror B303 respectively using a three-dimensional integration process. The three-dimensional integration process includes, but is not limited to, one or more of the following: through-silicon via (TSV), through-glass via (TGV), microbumps, wafer bonding, and chip bonding.

[0031] While specific embodiments of the present invention have been described above, those skilled in the art should understand that these are merely illustrative examples, and the scope of protection of the present invention is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but all such changes and modifications fall within the scope of protection of the present invention.

Claims

1. A MEMS micromirror-IMU integrated system, characterized in that: Includes a substrate (1); the upper surface of the substrate (1) is integrated with an inertial measurement unit, a micromirror array, and a control chip (4); The inertial measurement unit includes an accelerometer chip (201) and a gyroscope chip (202). The micromirror array includes a cup-shaped encapsulation housing (301) with the cup opening facing upwards; a MEMS micromirror A (302) is mounted on the inner bottom surface of the encapsulation housing (301); an even number of MEMS micromirrors B (303) of four or more are mounted on the inner side surface of the encapsulation housing (301), and each MEMS micromirror B (303) is arranged at equal intervals along the circumference. The input terminal of the control chip (4) is electrically connected to the output terminal of the accelerometer chip (201) and the output terminal of the gyroscope chip (202), respectively; the output terminal of the control chip (4) is electrically connected to the control terminal of the MEMS micromirror A (302) and the control terminal of each MEMS micromirror B (303), respectively.

2. The MEMS micromirror-IMU integrated system according to claim 1, characterized in that: The accelerometer chip (201), gyroscope chip (202), and package housing (301) are stacked and fixed together from bottom to top; the lower surface of the accelerometer chip (201) and the lower surface of the control chip (4) are fixed to the upper surface of the substrate (1).

3. The MEMS micromirror-IMU integrated system according to claim 1, characterized in that: The lower surface of the accelerometer chip (201), the lower surface of the gyroscope chip (202), the outer bottom surface of the package housing (301), and the lower surface of the control chip (4) are all fixed to the upper surface of the substrate (1).

4. A MEMS micromirror-IMU integrated system according to claim 1, 2, or 3, characterized in that: The accelerometer chip (201) is a MEMS three-axis accelerometer chip; the gyroscope chip (202) is a MEMS three-axis gyroscope chip.

5. A MEMS micromirror-IMU integrated system according to claim 1, 2, or 3, characterized in that: The encapsulation housing (301) has a prismatic cup-shaped structure; the MEMS micromirror A (302) and MEMS micromirror B (303) are both electrostatically driven MEMS micromirrors with five degrees of freedom.

6. A MEMS micromirror-IMU integrated system according to claim 1, 2, or 3, characterized in that: The control chip (4) is an ASIC control chip.

7. A MEMS micromirror-IMU integrated beam control method, the method being implemented based on the MEMS micromirror-IMU integrated system as described in claim 1, characterized in that: The method includes the following steps: First, the substrate (1) is fixed on the carrier, and a light source is placed directly above the encapsulation housing (301); Then, the light source is activated, and the light beam emitted by the light source is incident perpendicularly on the mirror surface of MEMS micromirror A (302) and is reflected perpendicularly by the mirror surface of MEMS micromirror A (302); Then, the control chip (4) generates a drive control signal and sends the drive control signal to MEMS micromirror A (302) and each MEMS micromirror B (303), thereby causing the mirror surface of MEMS micromirror A (302) and the mirror surface of each MEMS micromirror B (303) to deflect; at this time, the light beam emitted by the light source is obliquely incident on the mirror surface of MEMS micromirror A (302), and after being obliquely reflected by the mirror surface of MEMS micromirror A (302), it is obliquely incident on the mirror surface of MEMS micromirror B (303), and then after being obliquely reflected by the mirror surface of MEMS micromirror B (303), the light beam is scanned; During this process, the inertial measurement unit and the control chip (4) compensate for the beam pointing deviation, so that the beam pointing in inertial space remains unchanged; specifically including: a. Rotation compensation mode: When the carrier rotates due to attitude change, the beam direction deviates at an angle; the gyroscope chip (202) detects the angular velocity of the carrier in real time and sends the detection result to the control chip (4); the control chip (4) calculates the rotation angle of the carrier according to the detection result, generates a compensation control signal according to the rotation angle of the carrier, and then sends the compensation control signal to MEMS micromirror A (302) and each MEMS micromirror B (303), thereby causing the mirror surface of MEMS micromirror A (302) and the mirror surface of each MEMS micromirror B (303) to rotate in the opposite direction around the corresponding axis by the same angle, thereby compensating for the angle deviation of the beam direction, and thus making the beam direction in inertial space remain unchanged; b. Translation compensation mode: When the carrier is translated due to vibration, the beam direction will deviate. The accelerometer chip (201) detects the acceleration of the carrier in real time and sends the detection result to the control chip (4). The control chip (4) calculates the translation distance of the carrier according to the detection result and generates a compensation control signal according to the translation distance of the carrier. Then, the compensation control signal is sent to MEMS micromirror A (302) and each MEMS micromirror B (303), thereby causing the mirror surface of MEMS micromirror A (302) and the mirror surface of each MEMS micromirror B (303) to be translated by the same distance in the opposite direction along the corresponding axis, thereby compensating for the position deviation of the beam direction and making the beam direction remain unchanged in inertial space.

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