CN119030365A - Dynamic aperture control mechanism based on micro-ultrasonic motor and its driving method - Google Patents

Abstract

A dynamic diaphragm control mechanism based on a micro-ultrasonic motor and a driving method thereof belong to the field of diaphragm control technology, and in particular to a dynamic diaphragm control mechanism based on a micro-ultrasonic motor and a driving method thereof; the problems of insufficient control accuracy, delayed response speed, and excessive system complexity existing in the existing dynamic diaphragm control mechanism, which cannot meet the needs of high-precision optical imaging, are solved; the control mechanism includes an ultrasonic motor; the ultrasonic motor is used to drive the driving shaft body to rotate around its axis according to the inverse piezoelectric effect and friction coupling, thereby adjusting the opening and closing of the diaphragm mechanism. The dynamic diaphragm control mechanism based on a micro-ultrasonic motor and a driving method thereof are suitable for controlling the diaphragm of cameras in the fields of aerospace photography, microscopic imaging, precise terrain surveying, medical imaging, and industrial control.

Description

Dynamic aperture control mechanism based on micro-ultrasonic motor and its driving method

Technical Field

The present invention relates to the technical field of aperture control, and in particular to a dynamic aperture control mechanism based on a micro-ultrasonic motor and a driving method thereof.

Background Art

With the rapid development of optical imaging technology, the requirements for imaging quality, dynamic range and environmental adaptability are increasing. As an important component for adjusting light flux and controlling depth of field, the control accuracy and response speed of the dynamic aperture directly affect the imaging effect.

Traditional aperture control mechanisms are mostly driven by electromagnetic motors. However, the electromagnetic motor drive method has the disadvantages of being susceptible to electromagnetic interference and delayed response, which leads to limitations in control accuracy, response speed, system stability and reliability, and cannot meet the needs of modern high-precision optical imaging systems for fast and precise adjustment of the aperture; at the same time, the electromagnetic motor drive method often requires complex mechanical transmission components, which leads to the disadvantages of large size and complex structure, making it difficult to meet the needs of modern high-precision optical imaging systems for miniaturization and lightweight. The above disadvantages of the traditional aperture control mechanism limit the further improvement of the imaging quality of the optical imaging system.

In recent years, ultrasonic motors, as a new type of micro motor, have gradually attracted attention due to their unique advantages. Ultrasonic motors use the inverse piezoelectric effect of piezoelectric materials to excite high-frequency vibrations, and drive the rotor to rotate through the friction between the stator and the rotor, without the need for intermediate mechanisms such as gears or transmission belts, thereby achieving direct drive and high-precision positioning. Compared with traditional electromagnetic motors, ultrasonic motors have significant characteristics such as compact structure, easy miniaturization, fast response speed, power-off self-locking, and no electromagnetic interference. They are particularly suitable for optical control systems that require high precision, high dynamic response and high reliability. The use of ultrasonic motors to replace electromagnetic motors has gradually become a new technical development trend in this field.

In summary, the dynamic aperture control mechanism in the existing technology often has problems such as insufficient control accuracy, slow response speed, and high system complexity, which makes it difficult to meet the needs of centimeter-level or even higher precision imaging. Therefore, exploring new control mechanisms to improve the accuracy and efficiency of aperture adjustment has become the key to promoting the development of high-precision optical imaging technology.

Summary of the invention

The present invention proposes a dynamic aperture control mechanism based on a micro-ultrasonic motor and a driving method thereof, which solves the problems of insufficient control accuracy, slow response speed, and high system complexity of the existing dynamic aperture control mechanism, and thus cannot meet the needs of high-precision optical imaging.

The dynamic aperture control mechanism based on the micro-ultrasonic motor described in the present invention has the following technical solutions:

The control mechanism includes: an ultrasonic motor, a drive shaft and an aperture mechanism;

The driving shaft comprises a driving shaft body and an aperture connecting piece;

One end of the driving shaft body is fixedly connected to the aperture mechanism via an aperture connecting piece;

The other end of the driving shaft body is connected to the ultrasonic motor; the ultrasonic motor is used to drive the driving shaft body to rotate around its axis according to the inverse piezoelectric effect and friction coupling, thereby adjusting the opening and closing of the aperture mechanism.

Further, a preferred embodiment is provided, wherein the ultrasonic motor comprises: a stator, two rotors, two preload springs and a nut;

The other end of the drive shaft body passes through a preload spring, a rotor, a stator, another rotor and another preload spring in sequence, and the end thereof is threadedly connected to a nut;

The two preload springs are both in a compressed state, and are used to provide a preload force for the rotor on the same side along the axis of the drive shaft body toward the stator, so that the two rotors fit tightly with the stator;

The stator is used to generate in-plane bending deformation motion and radial vibration deformation motion under the action of an excitation signal, and then drive the two rotors to rotate around the axis of the drive shaft body according to the friction coupling effect;

The two rotors are used to drive the driving shaft body to rotate around its axis.

Further, a preferred embodiment is provided, wherein the rotor is a conical disc, and a through hole is provided in the axial direction thereof;

The outer surface of the conical disc of the rotor is used to fit closely with the stator;

The through hole of the rotor is used to pass through the driving shaft body and is tightly matched with the driving shaft body.

Further, a preferred embodiment is provided, wherein the stator comprises piezoelectric ceramics and a metal matrix;

The piezoelectric ceramics include bending vibration ceramics and radial ceramics;

The bending vibration ceramics are symmetrically arranged on the upper and lower sides of the metal substrate along the Y-axis direction, and are used to excite the stator to perform in-plane bending deformation movement;

The radial ceramics are symmetrically arranged on the left and right sides of the metal substrate along the X-axis direction, and are used to excite the stator to perform radial vibration deformation movement.

Further, a preferred embodiment is provided, wherein the number of piezoelectric ceramics arranged on each side of the metal substrate is not less than 2;

The polarization directions of two adjacent bending vibration ceramics on the same side of the metal substrate are opposite;

The polarization directions of the two bending vibration ceramics arranged opposite to each other on both sides of the metal substrate are the same;

The polarization direction of the radial ceramics on the same side of the metal substrate is the same and opposite to the polarization direction of the radial ceramics on the other side.

Further, a preferred embodiment is provided, wherein the metal substrate is provided with a hollow structure and a driving ring along the Z-axis direction;

The hollow structure is used to increase the amplitude of the stator;

The drive ring is used to contact the rotor and convert the in-plane bending deformation motion and radial vibration deformation motion of the stator into driving force according to the friction coupling effect, so as to drive the rotor to rotate around the axis of the drive shaft body.

Furthermore, a preferred embodiment is provided, wherein the drive ring is in line contact with the rotor.

The present invention also proposes an optical imaging system, and its technical solution is as follows:

The system comprises a stator housing, an imaging housing, an imaging module and the above-mentioned dynamic aperture control mechanism;

The stator housing and the imaging housing are both housings with openings at the front and rear ends;

The dynamic aperture control mechanism is arranged in the stator housing, and the aperture mechanism is located at the front opening of the stator housing;

The rear end of the stator housing is inserted into the interior of the imaging housing from the front end opening of the imaging housing;

The rear end opening of the imaging housing is sealed with an imaging module;

The dynamic aperture control mechanism is used to control the amount of light input to the imaging module.

The present invention also proposes a driving method of a dynamic aperture control mechanism based on a micro-ultrasonic motor, and its technical solution is as follows:

The method is used to drive the above-mentioned dynamic aperture control mechanism;

The method comprises the following steps:

Applying two AC voltage excitation signals with a given phase difference to the bending vibration ceramic and the radial vibration ceramic respectively;

The stator is stimulated to produce in-plane bending deformation motion and radial vibration deformation motion, which drives the driving ring to produce an elliptical motion trajectory; the driving ring drives the rotor to rotate around the axis of the driving shaft body through the friction force;

The rotor drives the driving shaft body to rotate around its axis, thereby adjusting the opening and closing of the aperture mechanism.

Further, a preferred embodiment is provided, wherein the AC voltage excitation signal is a sinusoidal AC signal or a sinusoidal step pulse AC signal;

When the applied excitation signal is a sinusoidal AC signal:

The rotor performs continuous and smooth rotational motion to achieve continuous adjustment of the opening and closing of the aperture mechanism;

When the applied excitation signal is a sinusoidal step pulse AC signal:

The rotor performs a step-by-step high-resolution rotational motion to achieve a step-by-step high-resolution adjustment of the opening and closing of the aperture mechanism.

The present invention has the following beneficial effects:

1. The dynamic aperture control mechanism based on the micro-ultrasonic motor described in the present invention focuses on the deep integration of optical instruments and precision control technology. By utilizing the high-precision positioning, fast response and power-off self-locking characteristics of the ultrasonic motor, and combining its unique structural design, the control mechanism can perform high-precision dynamic regulation of the aperture mechanism in the optical imaging system, thereby optimizing the quality parameters of the optical imaging system, including improving the clarity and accuracy of optical imaging, enhancing the response agility of the optical imaging system to the adjustment of the aperture mechanism, and improving the operating stability of the entire optical imaging system. .

2. The dynamic aperture control mechanism based on a micro-ultrasonic motor described in the present invention is the essence of the improvement of the prior art in that it introduces an ultrasonic motor in a high-efficiency resonant mode, which has high-frequency vibration (over 20kHz) to ensure millisecond-level rapid response capability. The ultrasonic motor uses advanced friction drive principles to efficiently convert the precise vibration (micrometer level) of the stator at the microscopic level into the smooth rotation (centimeter level) of the rotor at the macroscopic level, directly driving the aperture to achieve fine adjustment. This unique design not only optimizes the architecture of the optical imaging system, significantly reduces the system volume, reduces the dependence on a large number of optical path components, thereby reducing the overall cost, but also eliminates complex mechanical transmission components, ensuring that the optical imaging system has faster dynamic response capabilities and lighter weight advantages. .

3. The dynamic aperture control mechanism based on the micro-ultrasonic motor described in the present invention is an improvement on the existing aperture control mechanism, and realizes high-precision and fast-response control of the dynamic aperture. It is of vital importance to promote the development of high-precision optical imaging technology in high-end application fields such as aerospace photography, microscopic imaging analysis, and precise terrain survey, and provides strong technical support and performance guarantee for these fields. At the same time, the optical imaging system using the dynamic aperture control mechanism can also be applied to fields such as medical imaging and industrial control.

4. The driving method of the dynamic aperture control mechanism based on the micro-ultrasonic motor described in the present invention realizes the focal length adjustment functions of large stroke and high resolution respectively by adopting different excitation signals. Specifically, when a periodic excitation signal is used to drive the ultrasonic motor, the rotor outputs continuous motion to achieve a large range of optical focusing; when a high-frequency step pulse signal is used to drive the ultrasonic motor, the rotor outputs step high-resolution motion to meet the needs of small-range high-resolution optical focusing. This flexible and changeable excitation method makes the aperture control mechanism have a wide range of application prospects in the fields of medical imaging cameras, space cameras, industrial cameras, etc.

The dynamic aperture control mechanism based on a micro-ultrasonic motor and the driving method thereof described in the present invention are suitable for controlling the aperture of cameras in the fields of aerospace photography, microscopic imaging, precise terrain surveying, medical imaging and industrial control.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

FIG1 is a schematic structural diagram of a dynamic aperture control mechanism based on a micro-ultrasonic motor in one embodiment of the present invention;

FIG2 is a schematic diagram of the structure of an ultrasonic motor in one embodiment of the present invention; wherein (a) is an oblique view of the ultrasonic motor; (b) is a left view of the ultrasonic motor; (c) is a schematic diagram of the structure of the rotor; and (d) is a schematic diagram of the structure of the drive shaft;

FIG3 is a schematic diagram of the assembly of a drive shaft and an aperture mechanism in one embodiment of the present invention; wherein (a) is an oblique view of the assembly of the drive shaft and the aperture mechanism; (b) is a left side view of the assembly of the drive shaft and the aperture mechanism; (c) is a schematic diagram of the structure of the aperture mechanism;

FIG4 is a schematic diagram of the structure of a stator in one embodiment of the present invention; wherein (a) is a schematic diagram of the overall structure of the stator; (b) is a schematic diagram of the polarization direction and electrical connection of the bending vibration ceramic; (c) is a schematic diagram of the polarization direction and electrical connection of the radial ceramic; (d) is a schematic diagram of the structure of the metal matrix;

FIG5 is a schematic diagram of the in-plane bending deformation motion and radial vibration deformation motion of the stator in one embodiment of the present invention; wherein (a) is the in-plane bending deformation motion; (b) is the radial vibration deformation motion;

FIG6 is a schematic diagram of excitation signals corresponding to in-plane bending deformation motion and radial vibration deformation motion in one embodiment of the present invention; wherein (a) is a continuous AC signal; (b) is a step AC signal; +A is the maximum value of the excitation signal voltage amplitude, and -A is the minimum value of the excitation signal voltage amplitude;

Reference numerals:

1. Stator; 1-1. Bending vibration ceramic; 1-1-1. First bending vibration ceramic; 1-1-2. Second bending vibration ceramic; 1-1-3. Third bending vibration ceramic; 1-1-4. Fourth bending vibration ceramic; 1-2. Radial ceramic; 1-2-1. First radial ceramic; 1-2-2. Second radial ceramic; 1-2-3. Third radial ceramic; 1-2-4. Fourth radial ceramic; 1-3. Metal matrix; 1-3-1. Hollow structure; 1-3-2. Drive ring; 1-3-3. Fixed hole structure; 2. Rotor; 2-1. Through hole; 2-2. Outer surface of conical disk; 3. Preload spring; 4. Drive shaft; 4-1. Aperture connector; 4-2. Drive shaft body; 5. Aperture mechanism; 5-1. Aperture blades; 5-2. Aperture lever; 6. Nut; 7. Stator housing; 8. Imaging housing; 9. Imaging module.

DETAILED DESCRIPTION

In order to make the technical solutions and advantages of the present invention more clearly described, the specific implementation methods of the present invention will be further described in detail and completely in conjunction with the accompanying drawings. The various implementation methods described below are only part of the preferred solutions of the present invention, rather than all implementation methods; the various implementation methods described below are intended to explain the present invention and cannot be understood as limitations on the present invention; the reasonable combination of technical features defined in the various implementation methods of the present invention, and all other implementation methods obtained by ordinary technicians in the field without creative work based on the implementation methods of the present invention, are within the scope of protection of the present invention.

Embodiment 1: This embodiment is described in conjunction with FIGS. 1 to 6. This embodiment provides a dynamic aperture control mechanism based on a micro-ultrasonic motor. The specific implementation contents are as follows:

The control mechanism includes: an ultrasonic motor, a drive shaft 4 and an aperture mechanism 5;

The driving shaft 4 includes a driving shaft body 4-2 and an aperture connecting member 4-1;

One end of the driving shaft body 4-2 is fixedly connected to the aperture mechanism 5 through the aperture connector 4-1;

The other end of the driving shaft body 4-2 is connected to the ultrasonic motor; the ultrasonic motor is used to drive the driving shaft body 4-2 to rotate around its axis according to the inverse piezoelectric effect and friction coupling, thereby adjusting the opening and closing of the aperture mechanism 5.

In this embodiment, the driving shaft 4 and the aperture mechanism 5 are firmly connected by a fixed connection to ensure the stability and accuracy of the rotational motion.

Furthermore, a preferred embodiment is provided, in which the drive shaft body 4-2 is a long tubular object, and its cross-sectional shape is preferably an elliptical shape, or a variety of shapes such as square, circular, triangular, trapezoidal and polygonal.

In this embodiment, the aperture mechanism 5 is a common structure, which includes an aperture inner ring, aperture blades 5-1 and an aperture lever 5-2. There is friction between the aperture inner ring and the aperture blades 5-1, and the aperture blades 5-1 are driven to move by driving the aperture inner ring to rotate, thereby adjusting the opening and closing of the aperture mechanism 5.

The aperture mechanism 5 is used to adjust the amount of incoming light in the optical imaging system.

Furthermore, a preferred embodiment is provided, wherein the aperture connecting member 4 - 1 comprises an annular outer wall for driving the aperture inner ring of the aperture mechanism 5 to rotate, and is therefore called an aperture driving ring; the annular outer wall is transitionally matched with the aperture inner ring of the aperture mechanism 5 .

In this embodiment, the overall shape of the aperture connector 4-1 is similar to the commonly seen "mineral water bottle cap", including a circular bottom surface and a circular outer wall; the opening edge of one side of the circular outer wall is connected to the edge of the circular bottom surface.

The circular bottom surface is fixedly connected to the driving shaft body 4-2; the axis through the circular point of the circular bottom surface is colinear with the axis of the driving shaft body 4-2.

In this embodiment, the transition fit between the annular outer wall and the inner ring of the aperture ensures that the aperture mechanism 5 can move smoothly and accurately around the axis of the drive shaft body 4-2.

In this embodiment, the ultrasonic motor is an ultrasonic motor in a high-efficiency resonant mode, which has high-frequency vibration (over 20kHz), ensuring millisecond-level rapid response capability. The ultrasonic motor uses advanced friction drive principles to efficiently convert the precise vibration (micrometer level) of the stator at the microscopic level into the smooth rotation (centimeter level) of the rotor at the macroscopic level, directly driving the aperture mechanism to achieve fine adjustment. This unique design not only optimizes the architecture of the optical imaging system, significantly reduces the system volume, reduces the dependence on a large number of optical path components, thereby reducing the overall cost, but also eliminates complex mechanical transmission components, ensuring that the optical imaging system has faster dynamic response capabilities and lighter weight advantages.

Embodiment 2: This embodiment is described in conjunction with FIGS. 1 to 6. This embodiment is a further limitation of the dynamic aperture control mechanism based on the micro-ultrasonic motor described in Embodiment 1. The specific implementation contents are as follows:

The ultrasonic motor comprises: a stator 1, two rotors 2, two preload springs 3 and a nut 6;

The other end of the drive shaft body 4 - 2 passes through a preload spring 3, a rotor 2, a stator 1, another rotor 2 and another preload spring 3 in sequence, and the end thereof is threadedly connected with a nut 6;

The two preload springs 3 are both in a compressed state, and are used to provide a preload force for the rotor 2 on the same side along the axis of the drive shaft body 4-2 toward the stator 1, so that the two rotors 2 fit tightly with the stator 1;

The stator 1 is used to generate in-plane bending deformation movement and radial vibration deformation movement under the action of an excitation signal, and then drive the two rotors 2 to rotate around the axis of the drive shaft body 4-2 according to the friction coupling effect;

The two rotors 2 are used to drive the drive shaft body 4 - 2 to rotate around its axis.

In this embodiment, as shown in Fig. 2, the axial direction of the drive shaft body 4-2 is the Z-axis direction in the figure. Meanwhile, the Y-axis direction in the figure is the vertical upward direction perpendicular to the Z-axis direction; the X-axis direction in the figure is the horizontal leftward direction perpendicular to the Z-axis direction.

In this embodiment, the stator 1 can drive the rotor 2 to perform precise rotational motion around the axial direction of the drive shaft body 4 - 2 .

In this embodiment, for the first preload spring 3, one end thereof abuts against the circular bottom surface of the aperture connecting member 4-1, and the other end thereof abuts against the first rotor 2, and a preload force is provided by spring compression.

As for the second preload spring 3, one end thereof abuts against the nut 6, and the other end thereof abuts against the second rotor 2, and a preload force is provided by spring compression.

By applying a pre-tightening force, the rotor 2 and the stator 1 are closely fitted, and then the microscopic deformation movement of the stator 1 is effectively converted into the macroscopic rotational movement of the rotor 2 through the action of friction force.

In this embodiment, the dynamic aperture control mechanism based on the micro-ultrasonic motor has a compact structure and has the characteristics of easy miniaturization, fast response, high resolution, self-locking when power is off, no electromagnetic interference, and light weight. The aperture adjustment function is realized through the rotational output motion of the ultrasonic motor, and is suitable for high-precision optical imaging systems.

In this embodiment, the shaft body of the drive shaft body 4 - 2 is processed with an external thread for threaded connection with the nut 6 .

Embodiment 3: This embodiment is described in conjunction with FIGS. 1 to 6. This embodiment is a further limitation of the dynamic aperture control mechanism based on the micro-ultrasonic motor described in Embodiment 2. The specific implementation contents are as follows:

The rotor 2 is a conical disc with a through hole in the axial direction;

The outer surface 2-2 of the conical disc of the rotor 2 is used to fit tightly with the stator 1;

The through hole 2-1 of the rotor 2 is used to pass through the drive shaft body 4-2 and fit tightly with the drive shaft body 4-2.

In this embodiment, the rotor 2 adopts a conical hollow structure (ie, having a through hole), which not only reduces the weight of the rotor, but also improves the rigidity and stability of the connection between the rotor 2 and the drive shaft body 4-2, which helps to improve the imaging efficiency of the optical imaging system.

In this embodiment, the outer surface of the rotor 2 is tightly fitted to the stator 1, and then under the effect of friction coupling, the stator drives the rotor to rotate.

In this embodiment, the through hole of the rotor 2 is tightly matched with the driving shaft body 4-2, and the driving shaft body is then driven to rotate by the rotor.

In this embodiment, the cross-sectional shape of the through hole depends on the cross-sectional shape of the drive shaft body 4-2. If the cross-sectional shape of the drive shaft body 4-2 is elliptical, the cross-sectional shape of the through hole is also elliptical.

The ellipse-like shape, as shown in FIG. 2 , is formed by a pair of opposite straight edges and a pair of opposite arc edges, and is similar to an ellipse as a whole.

Embodiment 4: This embodiment is described in conjunction with FIGS. 1 to 6. This embodiment is a further limitation of the dynamic aperture control mechanism based on the micro-ultrasonic motor described in Embodiment 3. The specific implementation contents are as follows:

The stator 1 includes piezoelectric ceramics and a metal matrix 1-3;

The piezoelectric ceramics include a bending vibration ceramic 1-1 and a radial ceramic 1-2;

The bending vibration ceramics 1-1 are symmetrically arranged on the upper and lower sides of the metal substrate 1-3 along the Y-axis direction, and are used to excite the stator 1 to perform in-plane bending deformation movement;

The radial ceramics 1 - 2 are symmetrically arranged on the left and right sides of the metal substrate 1 - 3 along the X-axis direction, and are used to excite the stator 1 to perform radial vibration deformation movement.

In this embodiment, by providing bending vibration ceramics and radial ceramics, the ultrasonic motor can simultaneously achieve in-plane bending and in-plane radial vibration, which greatly improves the motion performance and stability of the ultrasonic motor and enables the ultrasonic motor to drive the aperture mechanism more efficiently.

In this embodiment, the bending vibration ceramic and the radial ceramic are respectively connected to the excitation signal through wires to excite the stator 1.

In this embodiment, the piezoelectric ceramic is a sheet structure, which can also be called a piezoelectric ceramic sheet. All piezoelectric ceramics (including bending vibration ceramics and radial ceramics) are tightly attached to the metal substrate 1-3, ensuring efficient energy transfer.

Furthermore, a preferred embodiment is provided, wherein the bending vibration ceramic, radial ceramic and metal matrix 1-3 together constitute a piezoelectric structure, specifically a patch type structure.

In this embodiment, the structure for realizing the in-plane bending deformation motion and radial vibration deformation motion is a patch structure. The patch structure has the advantages of fast response speed and high control accuracy, and can effectively convert electrical energy into mechanical energy, thereby ensuring the stable and efficient operation of the ultrasonic motor, thereby driving the rotor 2 to perform precise motion.

In this embodiment, the patch structure has the advantages of small size, simple structure, and easy miniaturization design compared to the traditional bolt-pretightened sandwich piezoelectric structure.

Embodiment 5: This embodiment is described in conjunction with FIGS. 1 to 6. This embodiment is a further limitation of the dynamic aperture control mechanism based on the micro-ultrasonic motor described in Embodiment 4. The specific implementation contents are as follows:

The number of piezoelectric ceramics arranged on each side of the metal substrate 1-3 is not less than 2;

The polarization directions of two adjacent bending vibration ceramics on the same side of the metal substrate 1-3 are opposite;

The polarization directions of the two bending vibration ceramics arranged opposite to each other on both sides of the metal substrate 1-3 are the same;

The polarization direction of the radial ceramics on the same side of the metal substrate 1 - 3 is the same and opposite to the polarization direction of the radial ceramics on the other side.

Further, a preferred embodiment is provided, the metal base 1-3 has a square plate-like structure; the number of piezoelectric ceramics on each side of the metal base 1-3 is 2; specifically:

The first bending vibration ceramic 1-1-1 and the second bending vibration ceramic 1-1-2 are evenly attached to the left and right sides of the upper side of the metal substrate 1-3;

The third bending vibration ceramic 1-1-3 and the fourth bending vibration ceramic 1-1-4 are evenly attached to the left and right sides of the lower side of the metal substrate 1-3;

The left side of the metal substrate 1-3 is evenly bonded with a first radial ceramic 1-2-1 and a second radial ceramic 1-2-2;

The third radial ceramic 1-2-3 and the fourth radial ceramic 1-2-4 are evenly attached to the upper and lower sides of the right side of the metal substrate 1-3.

In this embodiment, as shown in FIG4:

The polarization directions of two adjacent bending vibration ceramics on the same side of the metal substrate 1-3 are opposite. For example, the polarization directions of the first bending vibration ceramic 1-1-1 and the second bending vibration ceramic 1-1-2 are opposite, the polarization direction of the first bending vibration ceramic 1-1-1 is upward, and the polarization direction of the second bending vibration ceramic 1-1-2 is downward; the polarization directions of the third bending vibration ceramic 1-1-3 and the fourth bending vibration ceramic 1-1-4 are opposite, the polarization direction of the third bending vibration ceramic 1-1-3 is upward, and the polarization direction of the fourth bending vibration ceramic 1-1-4 is downward.

The polarization directions of the two bending vibration ceramics arranged opposite to each other on both sides of the metal substrate 1-3 are the same. For example, the polarization directions of the first bending vibration ceramic 1-1-1 and the third bending vibration ceramic 1-1-3 are both upward; and the polarization directions of the second bending vibration ceramic 1-1-2 and the fourth bending vibration ceramic 1-1-4 are both downward.

The polarization directions of the radial ceramics on the same side of the metal substrate 1-3 are the same and opposite to the polarization directions of the radial ceramics on the other side. For example, the polarization directions of the first radial ceramic 1-2-1 and the second radial ceramic 1-2-2 are both rightward; and the polarization directions of the third radial ceramic 1-2-3 and the fourth radial ceramic 1-2-4 are both leftward.

Furthermore, a preferred embodiment is provided, the piezoelectric ceramic is a rectangular structure, specifically a rectangular sheet. Furthermore, the piezoelectric ceramic is not limited to a rectangular structure, but can also be other shapes such as a circular ring structure, mainly depending on the mechanical structure of the metal substrate 1-3.

Embodiment 6: This embodiment is described in conjunction with FIGS. 1 to 6. This embodiment is a further limitation of the dynamic aperture control mechanism based on the micro-ultrasonic motor described in Embodiment 4. The specific implementation contents are as follows:

The metal substrate 1-3 is provided with a hollow structure 1-3-1 and a driving ring 1-3-2 along the Z-axis direction;

The hollow structure 1-3-1 is used to increase the amplitude of the stator 1;

The drive ring 1-3-2 is used to contact the rotor 2, and convert the in-plane bending deformation movement and radial vibration deformation movement of the stator 1 into driving force according to the friction coupling effect, so as to drive the rotor 2 to rotate around the axis of the drive shaft body 4-2.

In this embodiment, the amplitude of the stator is increased by the hollow structure, so that the metal vibration of the stator is efficiently transmitted to the rotor, thereby achieving efficient and accurate rotational motion output.

In this embodiment, the rotor and the driving ring are brought into close contact by the pre-tightening force, thereby ensuring effective transmission of the driving force and ensuring the structural stability of the entire system.

Embodiment 7: This embodiment is described in conjunction with FIGS. 1 to 6. This embodiment is a further limitation of the dynamic aperture control mechanism based on the micro-ultrasonic motor described in Embodiment 6. The specific implementation contents are as follows:

The driving ring 1-3-2 is in line contact with the rotor 2.

In this embodiment, a line contact method is adopted to reduce the contact area and reduce the friction resistance.

Furthermore, a preferred embodiment is provided, in which the drive ring 1-3-2 is made of wear-resistant material to withstand long-term friction and reduce wear.

Further, a preferred embodiment is provided in which the drive ring 1-3-2 is in the shape of a circular ring or a square ring, that is, its cross-section is a circular ring or a rectangle to ensure sufficient contact with the rotor.

Embodiment 8: This embodiment is described in conjunction with FIGS. 1 to 6. This embodiment provides an optical imaging system, and the specific implementation contents are as follows:

The system comprises a stator housing 7, an imaging housing 8, an imaging module 9 and the dynamic aperture control mechanism described in the above embodiment;

The stator housing 7 and the imaging housing 8 are both housings with openings at the front and rear ends;

The dynamic aperture control mechanism is arranged in the stator housing 7, and the aperture mechanism 5 is located at the front opening of the stator housing 7; the rear end of the stator housing 7 is inserted into the imaging housing 8 from the front opening of the imaging housing 8;

The rear end opening of the imaging housing 8 is sealed with an imaging module 9;

The dynamic aperture control mechanism is used to control the amount of light input to the imaging module 9 .

In this embodiment, the amount of incoming light is controlled by a dynamic aperture control mechanism to achieve optical imaging effects with different exposure amounts and depths of field.

In this embodiment, the dynamic aperture control mechanism is disposed in the stator housing 7 to ensure smooth transmission of light, and at the same time, the light output to the imaging module 9 can only be incident from the aperture mechanism 5 .

In this embodiment, the dynamic aperture control mechanism is disposed in the stator housing 7 and the stator housing 7 is embedded in the imaging housing 8, thereby achieving a miniaturized and compact design of the system.

In this embodiment, the imaging module 9 is used to output images.

By adjusting the amount of light input to the imaging module 9, the depth of field and the exposure can be adjusted.

By adjusting the depth of field, the clear range of the image output by the imaging module 9 and the virtual-real contrast between the foreground and background objects can be controlled.

By adjusting the exposure, the brightness of the image output by the imaging module 9 can be controlled.

Furthermore, a preferred embodiment is provided, wherein the imaging module 9 includes a CMOS sensor and a lens module.

Furthermore, a preferred embodiment is provided in which a fixing hole structure 1-3-3 is provided on the metal substrate 1-3 for fixedly connecting with the stator housing 7 via pins.

In this embodiment, the metal substrate 1-3 may also be fixedly connected to the stator housing by using fixing elements.

Further, a preferred embodiment is provided, wherein a guide groove is provided on the inner wall of the imaging housing 8; and a guide column is provided on the outer surface of the stator housing 7;

The stator housing 7 is inserted into the imaging housing 8 through the cooperation of the guide column and the guide groove.

Embodiment 9: This embodiment is described in conjunction with FIGS. 1 to 6. This embodiment provides a driving method for a dynamic aperture control mechanism based on a micro-ultrasonic motor. The specific implementation contents are as follows:

The method is used to drive the dynamic aperture control mechanism described in the above embodiment;

The method comprises the following steps:

Apply two AC voltage excitation signals with a given phase difference to the bending vibration ceramic 1-1 and the radial ceramic 1-2 respectively;

The stator 1 is stimulated to produce in-plane bending deformation motion and radial vibration deformation motion, driving the driving ring 1-3-2 to produce an elliptical motion trajectory;

The driving ring 1-3-2 drives the rotor 2 to rotate around the axis of the driving shaft body 4-2 through the friction force;

The rotor 2 drives the driving shaft body 4 - 2 to rotate around its axis, thereby adjusting the opening and closing of the aperture mechanism 5 .

In this embodiment, by precisely controlling the AC voltage excitation signal of the piezoelectric ceramic piece (such as a sinusoidal AC signal or a sinusoidal step pulse AC signal), the rotor can be driven to move precisely around the axis, thereby driving the aperture mechanism to achieve high-precision rotational motion.

In this embodiment, the driving method has the advantages of fast response speed and high control accuracy, and can meet the optical imaging requirements of centimeter level or even higher accuracy.

In this implementation, the phase difference between the two AC voltage excitation signals is changed to adjust the magnitude and direction of the driving force, thereby achieving a reverse driving function.

Embodiment 10. This embodiment is described in conjunction with FIGS. 1 to 6. This embodiment further limits the driving method of the dynamic aperture control mechanism based on the micro-ultrasonic motor described in Embodiment 9. The specific implementation content is as follows: the AC voltage excitation signal is a sinusoidal AC signal or a sinusoidal step pulse AC signal;

When the applied excitation signal is a sinusoidal AC signal:

The rotor 2 performs continuous and smooth rotational motion to achieve continuous adjustment of the opening and closing of the aperture mechanism 5;

When the applied excitation signal is a sinusoidal step pulse AC signal:

The rotor 2 performs a step-by-step high-resolution rotational motion to achieve a step-by-step high-resolution adjustment of the opening and closing of the aperture mechanism 5 .

In this embodiment, both the sinusoidal AC signal and the sinusoidal step pulse AC signal have good stability and controllability, which can ensure the stable and efficient operation of the ultrasonic motor, and thus ensure the smooth operation and high-quality imaging of the optical imaging system; at the same time, they are also easy to generate and realize precise control, which provides convenience for the practical application of the system.

In this implementation, two excitation methods, a sinusoidal AC signal and a sinusoidal step pulse AC signal, are used, which have their own characteristics and complementary advantages.

The excitation method using sinusoidal AC signals is suitable for situations where large-scale and fast aperture adjustment is required.

The excitation method using sinusoidal step pulse AC signal is more suitable for application scenarios that require small-range, high-precision aperture adjustment.

Regardless of the excitation method, the advantages of ultrasonic motors can be fully utilized to achieve fast, accurate and stable aperture adjustment functions.

Furthermore, a preferred embodiment is provided, where when the applied excitation signal is a sinusoidal step pulse AC signal, the phase difference between the two sinusoidal step pulse AC signals is 90°.

In this embodiment, a sinusoidal step pulse AC signal is used, which can stimulate more precise and controllable in-plane bending deformation motion and radial vibration deformation motion compared to a sinusoidal AC signal.

The technical solution provided by the present invention is further described in detail above through several specific implementation modes in order to highlight the advantages and benefits of the technical solution provided by the present invention. However, the several specific implementation modes described above are not intended to be used as limitations on the present invention. Any reasonable changes and improvements to the present invention, reasonable combinations of implementation modes and equivalent substitutions based on the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims (10)

1. A dynamic aperture control mechanism based on a micro-ultrasonic motor, characterized in that the control mechanism comprises: an ultrasonic motor, a drive shaft (4) and an aperture mechanism (5); The driving shaft (4) comprises a driving shaft body (4-2) and an aperture connecting piece (4-1); One end of the driving shaft body (4-2) is fixedly connected to the aperture mechanism (5) via an aperture connecting piece (4-1); The other end of the driving shaft body (4-2) is connected to an ultrasonic motor; the ultrasonic motor is used to drive the driving shaft body (4-2) to rotate around its axis according to the inverse piezoelectric effect and friction coupling, thereby adjusting the opening and closing of the aperture mechanism (5). 2. The dynamic aperture control mechanism based on a micro-ultrasonic motor according to claim 1, characterized in that the ultrasonic motor comprises: a stator (1), two rotors (2), two preload springs (3) and a nut (6); The other end of the drive shaft body (4-2) passes through a preload spring (3), a rotor (2), a stator (1), another rotor (2) and another preload spring (3) in sequence, and its end is threadedly connected to a nut (6); The two preload springs (3) are both in a compressed state, and are used to provide a preload force for the rotor (2) on the same side along the axis of the drive shaft body (4-2) toward the stator (1), so that the two rotors (2) and the stator (1) fit tightly. The stator (1) is used to generate in-plane bending deformation movement and radial vibration deformation movement under the action of an excitation signal, and then drive the two rotors (2) to rotate around the axis of the drive shaft body (4-2) according to the friction coupling effect; The two rotors (2) are used to drive the driving shaft body (4-2) to rotate around its axis. 3. The dynamic aperture control mechanism based on a micro-ultrasonic motor according to claim 2, characterized in that the rotor (2) is a conical disk with a through hole in the axial direction thereof; The outer surface (2-2) of the conical disc of the rotor (2) is used to fit tightly with the stator (1); The through hole (2-1) of the rotor (2) is used to pass through the drive shaft body (4-2) and to fit tightly with the drive shaft body (4-2). 4. The dynamic aperture control mechanism based on a micro-ultrasonic motor according to claim 3, characterized in that the stator (1) comprises piezoelectric ceramics and a metal matrix (1-3); The piezoelectric ceramic comprises a bending vibration ceramic (1-1) and a radial ceramic (1-2); The bending vibration ceramics (1-1) are symmetrically arranged on the upper and lower sides of the metal substrate (1-3) along the Y-axis direction, and are used to excite the stator (1) to perform in-plane bending deformation movement; The radial ceramics (1-2) are symmetrically arranged on the left and right sides of the metal matrix (1-3) along the X-axis direction, and are used to excite the stator (1) to perform radial vibration deformation movement. 5. The dynamic aperture control mechanism based on a micro-ultrasonic motor according to claim 4, characterized in that the number of piezoelectric ceramics arranged on each side of the metal substrate (1-3) is not less than 2; The polarization directions of two adjacent bending vibration ceramics on the same side of the metal substrate (1-3) are opposite; The polarization directions of the two bending vibration ceramics arranged opposite to each other on both sides of the metal substrate (1-3) are the same; The polarization direction of the radial ceramics on the same side of the metal substrate (1-3) is the same and opposite to the polarization direction of the radial ceramics on the other side. 6. The dynamic aperture control mechanism based on a micro-ultrasonic motor according to claim 4, characterized in that the metal substrate (1-3) is provided with a hollow structure (1-3-1) and a driving ring (1-3-2) along the Z-axis direction; The hollow structure (1-3-1) is used to increase the amplitude of the stator (1); The drive ring (1-3-2) is used to contact the rotor (2) and convert the in-plane bending deformation movement and radial vibration deformation movement of the stator (1) into driving force based on the friction coupling effect, so as to drive the rotor (2) to rotate around the axis of the drive shaft body (4-2). 7. The dynamic aperture control mechanism based on a micro ultrasonic motor according to claim 6 is characterized in that the driving ring (1-3-2) and the rotor (2) are in line contact. 8. An optical imaging system, characterized in that the system comprises a stator housing (7), an imaging housing (8), an imaging module (9) and a dynamic aperture control mechanism according to any one of claims 1 to 7; The stator housing (7) and the imaging housing (8) are both housings with openings at both ends. The dynamic aperture control mechanism is arranged in the stator housing (7), and the aperture mechanism (5) is located at the front opening of the stator housing (7); The rear end of the stator housing (7) is inserted into the interior of the imaging housing (8) from the front end opening of the imaging housing (8); The rear end opening of the imaging housing (8) is sealed and provided with an imaging module (9); The dynamic aperture control mechanism is used to control the amount of light input to the imaging module (9). 9. A driving method for a dynamic aperture control mechanism based on a micro-ultrasonic motor, characterized in that the method is used to drive the dynamic aperture control mechanism according to any one of claims 1 to 7; The method comprises the following steps: Two AC voltage excitation signals with a given phase difference are applied to the bending vibration ceramic (1-1) and the radial ceramic (1-2) respectively; the stator (1) is excited to produce in-plane bending deformation motion and radial vibration deformation motion, driving the driving ring (1-3-2) to produce an elliptical motion trajectory; The driving ring (1-3-2) drives the rotor (2) to rotate around the axis of the driving shaft body (4-2) through the action of friction force; The rotor (2) drives the driving shaft body (4-2) to rotate around its axis, thereby adjusting the opening and closing of the aperture mechanism (5). 10. The driving method of the dynamic aperture control mechanism based on the micro-ultrasonic motor according to claim 9, characterized in that the AC voltage excitation signal is a sinusoidal AC signal or a sinusoidal step pulse AC signal; When the applied excitation signal is a sinusoidal AC signal: The rotor (2) performs continuous and smooth rotational motion to achieve continuous adjustment of the opening and closing of the aperture mechanism (5); When the applied excitation signal is a sinusoidal step pulse AC signal: The rotor (2) performs a step-by-step high-resolution rotational motion to achieve a step-by-step high-resolution adjustment of the opening and closing of the aperture mechanism (5).