Miniature inchworm piezoelectric automatic focusing device and driving method thereof

Abstract

The invention discloses a miniature inchworm piezoelectric automatic focusing device and a driving method thereof, belongs to the technical field of piezoelectric driving, and solves the problem that a traditional stepping motor is insufficient in the aspect of motion resolution of an imaging module and particularly cannot meet the requirement of high-precision optical imaging. An inchworm motor stator is fixedly installed on a fixing mechanism, an inchworm motor mover penetrates through a through hole of the fixing mechanism and is movably connected with the fixing mechanism, the inchworm motor stator abuts against the inchworm motor mover, a photosensitive element is fixedly connected to one end of the inchworm motor mover, and the inchworm motor stator drives the inchworm motor mover to move axially. And the photosensitive element is adjusted to a specified position. Piezoelectric displacement driving is achieved through the rhombic mechanism, stability and high efficiency are achieved, meanwhile, power-off self-locking and zero-power-consumption position keeping are achieved through the clamping mechanism and the locking mechanism, nanometer stepping precision and return-difference-free displacement are achieved through time sequence driving, and finally the photosensitive element is accurately positioned.

Description

Technical Field

[0001] The present invention relates to the field of piezoelectric drive technology, and in particular to a micro-inchworm piezoelectric autofocus device and a driving method thereof. Background Art

[0002] In recent years, the application of optical imaging technology in fields such as cell monitoring and micro-nano manipulation has become increasingly widespread, placing higher demands on the performance and stability of imaging systems. Currently, most autofocus systems are driven by stepper motors, electromagnetic motors, or voice coil motors. These systems suffer from large size, complex structure, high heat generation, and electromagnetic interference. Furthermore, due to limitations in their structure and drive principles, further improvements in focusing accuracy and speed are difficult to achieve, significantly limiting the development of these areas.

[0003] The piezoelectrically driven autofocus device has the advantages of fast response, high resolution, self-locking when power is off, and no electromagnetic interference. It has the characteristics of compact structure, large output force and high displacement resolution. It has broad application prospects in the development of cell monitoring, micro-nano manipulation, industrial cameras and other fields. Summary of the Invention

[0004] The present invention proposes a micro-inchworm piezoelectric autofocus device and a driving method thereof to solve the problem that traditional stepping motors are insufficient in imaging module motion resolution, especially the problem that they cannot meet the requirements of high-precision optical imaging.

[0005] A micro-inchworm piezoelectric autofocus device includes an inchworm motor mover, a fixing mechanism, an inchworm motor stator and a photosensitive element. The inchworm motor stator is fixedly mounted on the fixing mechanism. The inchworm motor mover passes through a through hole of the fixing mechanism and is movably connected to the fixing mechanism. The inchworm motor stator is tightly against the inchworm motor mover. The photosensitive element is fixedly connected to one end of the inchworm motor mover.

[0006] Furthermore, it also includes a base, and the stator of the inchworm motor is fixedly connected to the fixing mechanism through the base.

[0007] Furthermore, the motor stator includes a clamping mechanism, a transition plate, a driving mechanism and a locking mechanism, and the clamping mechanism, the transition plate, the driving mechanism, the base and the locking mechanism are fixedly connected in sequence.

[0008] Furthermore, the clamping mechanism includes a first piezoelectric stack, a first driving foot, a first set screw, a first pre-tightening block and a first concave diamond-shaped amplifying mechanism. The first driving foot is provided at one side displacement output end of the first concave diamond-shaped amplifying mechanism. The non-displacement output end of the first concave diamond-shaped amplifying mechanism is provided with a threaded through hole. The first set screw is screwed into the threaded through hole. The end of the first set screw presses against the first pre-tightening block, so that the first piezoelectric stack maintains pre-tightened contact with the inner side wall of the first concave diamond-shaped amplifying mechanism. When powered on, the first driving foot is pressed tightly against the rotor of the inchworm motor.

[0009] Furthermore, the locking mechanism includes a third piezoelectric stack, a third driving foot, a third set screw, a convex diamond-shaped amplifying mechanism and a third pre-tightening block. The third driving foot is provided at one side displacement output end of the convex diamond-shaped amplifying mechanism. The non-displacement output end of the convex diamond-shaped amplifying mechanism is provided with a threaded through hole. The end of the third set screw presses against the third pre-tightening block, so that the third piezoelectric stack maintains pre-tightened contact with the inner side wall of the convex diamond-shaped amplifying mechanism. When the power is not supplied, the third driving foot is pressed tightly against the rotor of the inchworm motor.

[0010] Furthermore, the other side displacement output ends of the first inwardly concave diamond-shaped amplifying mechanism and the outwardly convex diamond-shaped amplifying mechanism are both provided with positioning structures, and the positioning structures include bolts and waist-shaped holes. Threaded holes are provided on the transition plate and the base, and the bolts on the clamping mechanism and the locking mechanism pass through the corresponding waist-shaped holes and are screwed to the threaded holes on the transition plate and the base, respectively, and the clamping mechanism and the locking mechanism are fastened to the upper side of the transition plate and the lower side of the base, respectively. The aperture of the waist-shaped hole is smaller than the diameter of the nut on the bolt and larger than the diameter of the screw rod of the bolt.

[0011] Furthermore, the driving mechanism includes a second driving foot, a second piezoelectric stack, a second tightening screw, a second concave diamond-shaped amplifying mechanism and a second pre-tightening block. The second driving foot is arranged at a displacement output end on one side of the second concave diamond-shaped amplifying mechanism. The second driving foot is fixedly connected to the lower surface of the transition plate. The displacement output end on the other side of the second concave diamond-shaped amplifying mechanism is fixedly connected to the upper surface of the base. The non-displacement output end of the second concave diamond-shaped amplifying mechanism is provided with a threaded through hole. The end of the second tightening screw presses against the second pre-tightening block to keep the second piezoelectric stack in pre-tightened contact with the inner wall of the second concave diamond-shaped amplifying mechanism.

[0012] Furthermore, it also includes a linear bearing, which is fixedly installed in the through hole of the fixing mechanism, and the guide hole of the linear bearing limits the mover of the inchworm motor to slide in the linear bearing.

[0013] Furthermore, the fixing mechanism is provided with two coaxial through holes, and two linear bearings are provided, which are respectively fixedly installed in the two through holes of the fixing mechanism.

[0014] A driving method for a micro-inchworm piezoelectric autofocus device is provided. Based on the above-mentioned micro-inchworm piezoelectric autofocus device, the driving method comprises the following steps: S1. Adjust the waist-shaped hole of the locking mechanism 4-4 so that the third driving foot 4-4-2 is in full contact with the inchworm motor mover 1 and completes the locking action, ensuring that the inchworm motor mover 1 is in a stationary position; then adjust the positioning structure of the clamping mechanism 4-1 so that the first driving foot 4-1-2 is within the clamping range; S2. At the initial moment, a transient excitation voltage is applied to the first piezoelectric stack 4-1-1 of the clamping mechanism 4-1. +A 2 and the instantaneous excitation voltage of the third piezoelectric stack 4-4-1 of the locking mechanism 4-4 +A 3, the first driving foot 4-1-2 of the clamping mechanism 4-1 instantly clamps the inchworm motor mover 1, and at the same time the third driving foot 4-4-2 of the locking mechanism 4-4 releases the inchworm motor mover 1; then, the second piezoelectric stack 4-3-2 of the driving mechanism 4-3 is given a voltage from 0 to +A 1 slowly excites the voltage, and at the same time makes the clamping mechanism 4-1 + A 2 Excitation voltage and locking mechanism 4-4 +A 3 The excitation voltage remains unchanged, which causes the driving mechanism 4-3 to extend in the axial direction of the inchworm motor mover 1 and drives the clamping mechanism 4-1 to move. The first driving foot 4-1-2 of the clamping mechanism 4-1 is in full contact with the inchworm motor mover 1. The maximum static friction force is converted into driving force through the first driving foot 4-1-2, thereby driving the inchworm motor mover 1 to move continuously and smoothly along its axial direction. S3, the second piezoelectric stack 4-3-2 of the driving mechanism 4-3 maintains +A 1 excitation voltage, maintained at the maximum driving displacement; the excitation voltage of the first piezoelectric stack 4-1-1 of the clamping mechanism 4-1 is from +A 2 drops to 0, at this time the first driving foot 4-1-2 of the clamping mechanism 4-1 is retracted, releasing the inchworm motor mover 1 to return to the non-contact state, and at the same time the excitation voltage of the third piezoelectric stack 4-4-1 of the locking mechanism 4-4 is reduced from +A 3 drops to 0, at which point the third driving foot 4-4-2 of the locking mechanism 4-4 relocks the inchworm motor mover 1, keeping the inchworm motor mover 1 stationary; S4, the first piezoelectric stack 4-1-1 of the clamping mechanism 4-1 and the third piezoelectric stack 4-4-1 of the locking mechanism 4-4 maintain a 0V excitation voltage, and the state of the caterpillar motor mover 1 being locked by the third driving foot 4-4-2 of the locking mechanism 4-4 and not in contact with the first driving foot 4-1-2 of the clamping mechanism 4-1 is continued in S3; the piezoelectric stack 4-3-2 of the driving mechanism 4-3 is +A 1 The excitation voltage slowly decreases to 0, at which time the driving mechanism 4-3 retracts from the extended state to the initial state, driving the clamping mechanism 4-1 to reset, completing a cycle; S5, loop S1-S4 until the photosensitive element 5 reaches the designated position.

[0015] Beneficial Effects of the Invention: This invention addresses the limitations of conventional stepper motors in imaging module motion resolution, particularly their inability to meet the demands of high-precision optical imaging. To this end, an innovative micro-inchworm piezoelectric autofocus device and its driving method are proposed. This system is not only easily miniaturized and responsive, but also boasts significant advantages such as high resolution, self-locking upon power failure, and immunity to electromagnetic interference. This provides strong technical support for applications in areas such as cell observation, micro-nano manipulation, and industrial cameras.

[0016] The core of this invention lies in the use of an inchworm motor operating in low-frequency mode, achieving millisecond-level response speeds. This inchworm motor cleverly transforms the microscopic motion of the piezoelectric stack into stepping motion of the inchworm motor's actuator through friction, thereby achieving optical focal length adjustment. This innovative design not only addresses the bulky size, high number of optical path components, and high cost of traditional optical imaging systems, but also avoids the need for complex and redundant motion transmission mechanisms, resulting in a faster response speed and lighter weight.

[0017] Furthermore, the present invention utilizes a simple excitation method to achieve wide-range, high-resolution focus adjustment. Specifically, a periodic excitation signal can be used to drive the inchworm motor to produce continuous motion, thereby achieving wide-range, high-resolution optical focusing. This simple and easily controllable excitation scheme offers broad application prospects in fields such as micro-nano manipulation, industrial cameras, and cell microscopy. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a front view of a micro-inchworm piezoelectric autofocus device of the present invention; Figure 2 Schematic diagram of a driving mechanism of a micro-inchworm piezoelectric autofocus device of the present invention; Figure 3 A schematic diagram of a clamping mechanism of a micro-inchworm piezoelectric autofocus device of the present invention; Figure 4 This is a schematic diagram of a locking mechanism of a micro-inchworm piezoelectric autofocus device of the present invention; Figure 5 This is a schematic diagram of the excitation signal of a micro-inchworm piezoelectric autofocus device of the present invention, Figure (a) is the excitation signal of the clamping mechanism; Figure (b) is the excitation signal of the driving mechanism; Figure (c) is the excitation signal of the locking mechanism. +A 1 is the maximum value of the driving AC signal voltage amplitude; +A 2 is the maximum value of the clamping AC signal voltage amplitude; +A 3 is the maximum value of the locking AC signal voltage amplitude.

[0019] Among them, 1 is the mover of the inchworm motor, 2 is the linear bearing, 3 is the fixing mechanism, 4 is the stator of the inchworm motor, 4-1-1 is the first piezoelectric stack, 4-1-2 is the first driving foot, 4-1-3 is the first tightening screw, 4-1-4 is the first pre-tightening block, 4-1-5 is the first concave diamond-shaped magnifying mechanism, 4-3-1 is the second driving foot, 4-3-2 is the second piezoelectric stack, 4-3-3 is the second tightening screw, 4-3-4 is the second concave diamond-shaped magnifying mechanism, 4-3-5 is the second pre-tightening block, 4-4-1 is the third piezoelectric stack, 4-4-2 is the third driving foot, 4-4-3 is the third tightening screw, 4-4-4 is the third diamond-shaped magnifying mechanism, 4-4-5 is the third pre-tightening block 4-4-5, 5 is the photosensitive element, and 6 is the base. DETAILED DESCRIPTION

[0020] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0021] Reference Figure 1 As shown, a micro-inchworm piezoelectric autofocus device includes an inchworm motor mover 1, a fixing mechanism 3, an inchworm motor stator 4 and a photosensitive element 5. The inchworm motor stator 4 is fixedly mounted on the fixing mechanism 3. The inchworm motor mover 1 passes through a through hole of the fixing mechanism 3 and is movably connected to the fixing mechanism 3. The inchworm motor stator 4 is tightly against the inchworm motor mover 1. The photosensitive element 5 is fixedly connected to one end of the inchworm motor mover 1.

[0022] Furthermore, it also includes a base 6, The stator 4 of the looper motor is fixedly connected to the fixing mechanism 3 via the base 6 .

[0023] Furthermore, the motor stator 4 includes a clamping mechanism 4-1, a transition plate 4-2, a driving mechanism 4-3 and a locking mechanism 4-4, and the clamping mechanism 4-1, the transition plate 4-2, the driving mechanism 4-3, the base 6 and the locking mechanism 4-4 are fixedly connected in sequence.

[0024] Furthermore, the clamping mechanism 4-1 includes a first piezoelectric stack 4-1-1, a first driving foot 4-1-2, a first tightening screw 4-1-3, a first pre-tightening block 4-1-4 and a first concave diamond-shaped amplifying mechanism 4-1-5. The first driving foot 4-1-2 is arranged at one side displacement output end of the first concave diamond-shaped amplifying mechanism 4-1-5. The non-displacement output end of the first concave diamond-shaped amplifying mechanism 4-1-5 is provided with a threaded through hole. The first tightening screw 4-1-3 is screwed into the threaded through hole. The end of the first tightening screw 4-1-3 presses against the first pre-tightening block 4-1-4, so that the first piezoelectric stack 4-1-1 maintains pre-tightened contact with the inner wall of the first concave diamond-shaped amplifying mechanism 4-1-5. When powered on, the first driving foot 4-1-2 is pressed tightly against the rotor 1 of the inchworm motor.

[0025] Furthermore, the locking mechanism 4-4 includes a third piezoelectric stack 4-4-1, a third driving foot 4-4-2, a third tightening screw 4-4-3, an outward-convex diamond-shaped magnifying mechanism 4-4-4 and a third pre-tightening block 4-4-5. The third driving foot 4-4-2 is arranged at the displacement output end on one side of the outward-convex diamond-shaped magnifying mechanism 4-4-4. The non-displacement output end of the outward-convex diamond-shaped magnifying mechanism 4-4-4 is provided with a threaded through hole. The end of the third tightening screw 4-4-3 presses against the third pre-tightening block 4-4-5, so that the third piezoelectric stack 4-4-1 maintains pre-tightened contact with the inner wall of the outward-convex diamond-shaped magnifying mechanism 4-4-4. When the power is not supplied, the third driving foot 4-4-2 is pressed tightly against the rotor 1 of the inchworm motor.

[0026] Furthermore, the other side displacement output ends of the first concave diamond-shaped amplifying mechanism 4-1-5 and the convex diamond-shaped amplifying mechanism 4-4-4 are both provided with positioning structures, and the positioning structures include bolts and waist-shaped holes. Threaded holes are provided on the transition plate 4-2 and the base 6. The bolts on the clamping mechanism 4-1 and the locking mechanism 4-4 pass through the corresponding waist-shaped holes and are screwed to the threaded holes on the transition plate 4-2 and the base 6, respectively, and the clamping mechanism 4-1 and the locking mechanism 4-4 are fastened to the upper side of the transition plate 4-2 and the lower side of the base 6, respectively. The aperture of the waist-shaped hole is smaller than the diameter of the nut on the bolt and larger than the diameter of the screw rod of the bolt.

[0027] Furthermore, the driving mechanism 4-3 includes a second driving foot 4-3-1, a second piezoelectric stack 4-3-2, a second tightening screw 4-3-3, a second concave diamond-shaped amplifying mechanism 4-3-4 and a second pre-tightening block 4-3-5. The second driving foot 4-3-1 is arranged at the displacement output end on one side of the second concave diamond-shaped amplifying mechanism 4-3-4. The second driving foot 4-3-1 is fixedly connected to the lower surface of the transition plate 4-2. The displacement output end on the other side of the second concave diamond-shaped amplifying mechanism 4-3-4 is fixedly connected to the upper surface of the base 6. The non-displacement output end of the second concave diamond-shaped amplifying mechanism 4-3-4 is provided with a threaded through hole. The end of the second tightening screw 4-3-3 presses against the second pre-tightening block 4-3-5, so that the second piezoelectric stack 4-3-2 maintains pre-tightened contact with the inner wall of the second concave diamond-shaped amplifying mechanism 4-3-4.

[0028] Furthermore, it also includes a linear bearing 2, which is fixedly installed in the through hole of the fixing mechanism 3, and the guide hole of the linear bearing 2 limits the inchworm motor mover 1 to slide in the linear bearing 2.

[0029] Furthermore, the fixing mechanism 3 is provided with two coaxial through holes, and two linear bearings 2 are provided, which are respectively fixedly installed in the two through holes of the fixing mechanism 3 .

[0030] A driving method for a micro-inchworm piezoelectric autofocus device is provided. Based on the above-mentioned micro-inchworm piezoelectric autofocus device, the driving method comprises the following steps: S1. By adjusting the waist-shaped hole of the locking mechanism 4-4, the third driving foot 4-4-2 is in full contact with the inchworm motor mover 1 and the locking action is completed to ensure that the inchworm motor mover 1 is in a stationary position; then by adjusting the positioning structure of the clamping mechanism 4-1, the first driving foot 4-1-2 is within the clamping range.

[0031] S2. At the initial moment, apply an instantaneous excitation voltage of +A2 to the first piezoelectric stack 4-1-1 of the clamping mechanism 4-1 and an instantaneous excitation voltage of +A3 to the third piezoelectric stack 4-4-1 of the locking mechanism 4-4, so that the first driving foot 4-1-2 of the clamping mechanism 4-1 instantly clamps the inchworm motor mover 1, and at the same time, the third driving foot 4-4-2 of the locking mechanism 4-4 releases the inchworm motor mover 1; then, apply a slow voltage from 0 to +A1 to the second piezoelectric stack 4-3-2 of the driving mechanism 4-3. excitation voltage, while keeping the +A2 excitation voltage of the clamping mechanism 4-1 and the +A3 excitation voltage of the locking mechanism 4-4 unchanged, which makes the driving mechanism 4-3 extend in the axial direction of the inchworm motor mover 1 and drives the clamping mechanism 4-1 to move, and the first driving foot 4-1-2 of the clamping mechanism 4-1 is in full contact with the inchworm motor mover 1, and the maximum static friction force is converted into driving force through the first driving foot 4-1-2, thereby driving the inchworm motor mover 1 to move continuously and smoothly along its axial direction; S3, the second piezoelectric stack 4-3-2 of the driving mechanism 4-3 maintains the excitation voltage of +A1 and remains at the maximum driving displacement; the excitation voltage of the first piezoelectric stack 4-1-1 of the clamping mechanism 4-1 drops from +A2 to 0, at which time the first driving foot 4-1-2 of the clamping mechanism 4-1 retracts, releasing the inchworm motor mover 1 and returning it to a non-contact state, and at the same time the excitation voltage of the third piezoelectric stack 4-4-1 of the locking mechanism 4-4 drops from +A3 to 0, at which time the third driving foot 4-4-2 of the locking mechanism 4-4 re-locks the inchworm motor mover 1, keeping the inchworm motor mover 1 stationary; S4, the first piezoelectric stack 4-1-1 of the clamping mechanism 4-1 and the third piezoelectric stack 4-4-1 of the locking mechanism 4-4 maintain an excitation voltage of 0V, and the state of the inchworm motor mover 1 being locked by the third driving foot 4-4-2 of the locking mechanism 4-4 and not in contact with the first driving foot 4-1-2 of the clamping mechanism 4-1 continues in S3; the +A1 excitation voltage of the piezoelectric stack 4-3-2 of the driving mechanism 4-3 is slowly reduced to 0, at which time the driving mechanism 4-3 retracts from the extended state to the initial state, driving the clamping mechanism 4-1 to reset, completing a cycle; S5, loop S1-S4 until the photosensitive element 5 reaches the designated position.

[0032] Implementation Method 1 Reference Figure 1 As shown, a high-precision autofocus device driven by an inchworm motor comprises: an inchworm motor mover 1, a linear bearing 2, a fixing mechanism 3, an inchworm motor stator 4, a photosensitive element 5, and a base 6. A driving mechanism 4-3 in the inchworm motor stator 4 drives a clamping mechanism 4-1 to move along its axis. The inchworm motor mover 1 is fixedly connected to the photosensitive element 5, which is used to capture images. During actual operation, the clamping mechanism 4-1 in the inchworm motor stator 4 uses maximum static friction to drive the inchworm motor mover 1 along its axis, indirectly driving the photosensitive element 5 along its axis, achieving optical focusing.

[0033] Implementation Method 2 This embodiment further optimizes and expands the high-precision autofocus device driven by an inchworm motor described in Embodiment 1. This focus device incorporates key components such as a linear bearing 2, a fixing mechanism 3, a transition plate 4-2, and a base 6. The inchworm motor mover 1 is embedded within the linear bearing 2 to ensure radial positioning during movement. The drive mechanism 4-3 and locking mechanism 4-4 are compactly mounted on the base 6 to ensure the stability of the inchworm motor mover 1. The linear bearing 2 is mounted parallel to the through-hole of the fixing mechanism 3. Both the fixing mechanism 3 and the base 6 have threaded holes at both ends for easy attachment to external devices, ensuring the structural stability of the entire system. The transition plate 4-2 connects the clamping mechanism 4-1 and the drive mechanism 4-3 in series, ensuring efficient movement.

[0034] Implementation Method 3 Reference Figure 2 、 Figure 3 and Figure 4 As shown, this embodiment further refines the inchworm motor structure in the previous embodiment. Specifically, the driving mechanism 4-3 in the inchworm motor stator 4 includes a second driving foot 4-3-1, a second piezoelectric stack 4-3-2, a second tightening screw 4-3-3, a second concave diamond-shaped amplifying mechanism 4-3-4 and a second pre-tightening block 4-3-5, wherein the second pre-tightening block 4-3-5 and the second tightening screw 4-3-3 are used to tightly fit the second piezoelectric stack 4-3-2 to the driving mechanism 4-3, reduce the energy loss of the piezoelectric stack driving displacement, improve the displacement output efficiency and prevent the second piezoelectric stack 4-3-2 from being subjected to shear force; the clamping mechanism 4-1 includes a first piezoelectric stack 4-1-1, a first driving foot 4-1-2, a first tightening screw 4-1-3, a first pre-tightening block 4-1-4 and The first concave diamond-shaped amplifying mechanism 4-1-5 takes the axial direction of the inchworm motor mover 1 as the Y-axis, wherein the first piezoelectric stack 4-1-1 is tightly fitted inside the first concave diamond-shaped amplifying mechanism 4-1-5 along the Z-axis through the first pre-tightening block 4-1-4, and is used to stimulate the X-axis clamping movement of the inchworm motor; the locking mechanism 4-4 includes a third piezoelectric stack 4-4-1, a third driving foot 4-4-2, a third set screw 4-4-3, a third diamond-shaped amplifying mechanism 4-4-4 and a third pre-tightening block 4-4-5, wherein the third piezoelectric stack 4-4-1 is tightly fitted inside the convex diamond-shaped amplifying mechanism 4-4-4 along the Z-axis through the third pre-tightening block 4-4-5, and is used to stimulate the X-axis locking movement of the inchworm motor. In practical applications, the terminal blocks are connected to the first piezoelectric stack 4-1-1, the second piezoelectric stack 4-3-2, and the third piezoelectric stack 4-4-1 via wires, providing them with necessary electrical signals. The drive mechanism 4-3 and the clamping mechanism 4-1 are fixedly connected to the transition plate 4-2, ensuring efficient energy transfer.

[0035] Implementation Method 4 Building on the third embodiment, this embodiment further specifies that the autofocus mechanism's Y-axis drive, X-axis clamping, and X-axis locking motions are implemented using a piezoelectric structure, specifically a stacked structure. This structure offers advantages such as small size, simple structure, and ease of miniaturization.

[0036] Implementation Method Five This embodiment further defines the shapes of the second driving foot 4-3-1 of the driving mechanism 4-3, the first driving foot 4-1-2 of the clamping mechanism 4-1, and the third driving foot 4-4-2 of the locking mechanism 4-4. The driving feet are preferably rectangular to ensure sufficient contact with the inchworm motor mover 1. In practical applications, the contact with the inchworm motor mover 1 is linear, and the driving feet should be made of a suitable material with a certain degree of roughness to produce smooth relative motion.

[0037] Implementation Method 6 This embodiment describes in detail the structure of the linear bearing 2. The linear bearing 2 utilizes two parallel linear bearings. This design not only ensures the radial position of the inchworm motor mover 1 but also reduces vibration and shaking of the inchworm motor mover 1, allowing the inchworm motor mover 1 and the photosensitive element 5 to move smoothly and accurately along the axis.

[0038] Implementation Method Seven This embodiment describes in detail a method for driving a high-precision autofocus device driven by an inchworm motor. The method includes applying a certain AC voltage signal to the second piezoelectric stack 4-3-2, the first piezoelectric stack 4-1-1, and the third piezoelectric stack 4-4-1. This causes the driving mechanism 4-3 to generate a Y-axis driving motion, the clamping mechanism 4-1 to generate a clamping motion in the X-axis direction, and the locking mechanism 4-4 to generate a locking motion in the X-axis direction. By precisely controlling the voltage excitation signals of the three piezoelectric stacks, such as rectangular AC signals or trapezoidal AC signals, the inchworm motor mover 1 can be driven to move precisely along the axial direction, thereby driving the photosensitive element 5 to achieve high-precision axial motion. In addition, by changing the phase difference and step sequence of the three excitation signals, the reverse drive function can also be achieved. This driving method has the advantages of fast response speed and high control accuracy, and can meet the needs of higher-precision optical imaging.

[0039] Implementation Method Eight Building on the seventh embodiment, this embodiment further defines the specific form of the voltage excitation signal. The voltage excitation signal can be a rectangular AC signal or a trapezoidal AC signal. Both signal forms offer excellent stability and controllability, ensuring stable and efficient operation of the inchworm motor. Furthermore, they are easy to generate and precisely control, facilitating practical applications of the focuser.

[0040] The high-precision autofocus device driven by the inchworm motor of the present invention has a specific driving method: S1. By adjusting the waist-shaped hole of the locking mechanism 4-4, the third driving foot 4-4-2 is in full contact with the inchworm motor mover 1 and the locking action is completed to ensure that the inchworm motor mover 1 is in a stationary position; then by adjusting the positioning structure of the clamping mechanism 4-1, the first driving foot 4-1-2 is within the clamping range.

[0041] S2. According to Figure 5 It can be seen that in t The instantaneous excitation voltage applied to the first piezoelectric stack 4-1-1 of the clamping mechanism 4-1 at time 0 is + A 2 and the instantaneous excitation voltage of the third piezoelectric stack 4-4-1 of the locking mechanism 4-4 + A 3, the first driving foot 4-1-2 of the clamping mechanism 4-1 instantly clamps the inchworm motor mover 1, and at the same time the third driving foot 4-4-2 of the locking mechanism 4-4 releases the inchworm motor mover 1; Figure 5 (b) t 0 -t 1 This time period allows the second piezoelectric stack 4-3-2 of the driving mechanism 4-3 to +A 1 slowly excites the voltage, and at the same time makes the clamping mechanism 4-1 +A 2 Excitation voltage and locking mechanism 4-4 +A 3 The excitation voltage remains unchanged, which causes the driving mechanism 4-3 to extend in the axial direction of the inchworm motor mover 1 and drives the clamping mechanism 4-1 to move. The first driving foot 4-1-2 of the clamping mechanism 4-1 is in full contact with the inchworm motor mover 1. The maximum static friction force is converted into driving force through the first driving foot 4-1-2, thereby driving the inchworm motor mover 1 to move continuously and smoothly along its axial direction. S3, in Figure 5 of t 1 -t 2 time period, the second piezoelectric stack 4-3-2 of the driving mechanism 4-3 maintains +A 1 excitation voltage, maintained at the maximum driving displacement; the excitation voltage of the first piezoelectric stack 4-1-1 of the clamping mechanism 4-1 is from +A 2 drops to 0, at this time the first driving foot 4-1-2 of the clamping mechanism 4-1 is retracted, releasing the inchworm motor mover 1 to return to the non-contact state, and at the same time the excitation voltage of the third piezoelectric stack 4-4-1 of the locking mechanism 4-4 is reduced from +A 3 drops to 0, at this time the third driving foot 4-4-2 of the locking mechanism 4-4 re-locks the inchworm motor mover 1, so that the inchworm motor mover 1 remains stationary; during this period, the clamping mechanism 4-1 releases the inchworm motor mover 1, and the driving mechanism 4-3 and the clamping mechanism 4-1 are an independent whole.

[0042] S4, the first piezoelectric stack 4-1-1 of the clamping mechanism 4-1 and the third piezoelectric stack 4-4-1 of the locking mechanism 4-4 maintain a 0V excitation voltage, and the state of the caterpillar motor mover 1 being locked by the third driving foot 4-4-2 of the locking mechanism 4-4 and not in contact with the first driving foot 4-1-2 of the clamping mechanism 4-1 is continued in S3; the piezoelectric stack 4-3-2 of the driving mechanism 4-3 is +A 1 The excitation voltage slowly decreases to 0, at which time the driving mechanism 4-3 retracts from the extended state to the initial state, driving the clamping mechanism 4-1 to reset, completing a cycle; S5, loop S1-S4 until the photosensitive element 5 reaches the designated position.

[0043] Through multiple cycles, the inchworm motor's mover 1 performs high-resolution stepwise motion, and the photosensitive element 5 also moves precisely along its axial axis, thereby achieving high-resolution adjustment of the optical focus. Furthermore, by varying the phase difference and step sequence of the three excitation signals, reverse stepping drive can be implemented, further enhancing the system's flexibility and practicality. This focuser fully leverages the advantages of the inchworm motor to achieve fast, accurate, and stable optical focus adjustment.

[0044] The present invention realizes the displacement of the piezoelectric stack through a diamond-shaped amplification mechanism (the first / second inner concave type and the outer convex type), greatly improving the driving efficiency; the clamping mechanism 4-1 and the locking mechanism 4-4 utilize the self-locking characteristics of the piezoelectric stack when the power is off to achieve zero-power consumption position retention; the waist-shaped hole bolt structure makes the position of the clamping / locking mechanism adjustable, ensuring that the contact force of each driving foot and the mover is accurately adapted; the linear bearing 2 double-point coaxial guide ensures strict linear motion of the mover; the timing drive method coordinates the control of the clamping-driving-unlocking-reset action chain to achieve nanometer stepping accuracy and two-way backlash-free displacement accumulation, and finally enables the photosensitive element 5 to stably reach the target focal plane.

[0045] While the specific embodiments of the present invention have been described in detail above, these are intended to be exemplary only, and the present invention is not limited thereto. Any equivalent modifications or substitutions to the present invention that would be apparent to those skilled in the art are also within the scope of the present invention. Therefore, any equivalent modifications or substitutions made without departing from the spirit and scope of the present invention are intended to be encompassed within the scope of the present invention.

Claims

1. A micro-inchworm piezoelectric autofocus device, characterized in that: The invention comprises a inchworm motor mover (1), a fixing mechanism (3), a inchworm motor stator (4) and a photosensitive element (5), wherein the inchworm motor stator (4) is fixedly mounted on the fixing mechanism (3), the inchworm motor mover (1) passes through a through hole of the fixing mechanism (3) and is movably connected to the fixing mechanism (3), the inchworm motor stator (4) is tightly against the inchworm motor mover (1), and the photosensitive element (5) is fixedly connected to one end of the inchworm motor mover (1).

2. The micro-inchworm piezoelectric autofocus device according to claim 1, characterized in that: It also includes a base (6), and the inchworm motor stator (4) is fixedly connected to the fixing mechanism (3) through the base (6).

3. The micro-inchworm piezoelectric autofocus device according to claim 2, characterized in that: The motor stator (4) comprises a clamping mechanism (4-1), a transition plate (4-2), a driving mechanism (4-3) and a locking mechanism (4-4); the clamping mechanism (4-1), the transition plate (4-2), the driving mechanism (4-3), the base (6) and the locking mechanism (4-4) are fixedly connected in sequence.

4. The micro-inchworm piezoelectric autofocus device according to claim 3, characterized in that: The clamping mechanism (4-1) comprises a first piezoelectric stack (4-1-1), a first driving foot (4-1-2), a first set screw (4-1-3), a first pre-tightening block (4-1-4) and a first inward-concave rhombus-shaped amplifying mechanism (4-1-5). The first driving foot (4-1-2) is arranged at a displacement output end on one side of the first inward-concave rhombus-shaped amplifying mechanism (4-1-5). A threaded through hole is provided at a non-displacement output end of the first inward-concave rhombus-shaped amplifying mechanism (4-1-5). The first set screw (4-1-3) is screwed into the threaded through hole. The end of the first set screw (4-1-3) presses against the first pre-tightening block (4-1-4), so that the first piezoelectric stack (4-1-1) maintains pre-tightened contact with the inner side wall of the first inward-concave rhombus-shaped amplifying mechanism (4-1-5). When the power is on, the first driving foot (4-1-2) is pressed against the rotor (1) of the inchworm motor.

5. The micro-inchworm piezoelectric autofocus device according to claim 3, characterized in that: The locking mechanism (4-4) comprises a third piezoelectric stack (4-4-1), a third driving foot (4-4-2), a third set screw (4-4-3), an outwardly convex rhombus-shaped amplifying mechanism (4-4-4) and a third pre-tightening block (4-4-5). The third driving foot (4-4-2) is arranged at a displacement output end on one side of the outwardly convex rhombus-shaped amplifying mechanism (4-4-4). A threaded through hole is provided at a non-displacement output end of the outwardly convex rhombus-shaped amplifying mechanism (4-4-4). The end of the third set screw (4-4-3) presses against the third pre-tightening block (4-4-5), so that the third piezoelectric stack (4-4-1) maintains pre-tightened contact with the inner side wall of the outwardly convex rhombus-shaped amplifying mechanism (4-4-4). In the non-powered state, the third driving foot (4-4-2) is pressed against the rotor (1) of the inchworm motor.

6. The micro-inchworm piezoelectric autofocus device according to claim 4 or 5, characterized in that: The other side displacement output ends of the first inwardly concave diamond-shaped amplifying mechanism (4-1-5) and the outwardly convex diamond-shaped amplifying mechanism (4-4-4) are both provided with positioning structures, the positioning structures comprising bolts and waist-shaped holes, threaded holes being provided on the transition plate (4-2) and the base (6), the bolts on the clamping mechanism (4-1) and the locking mechanism (4-4) respectively passing through the corresponding waist-shaped holes and being screwed to the threaded holes on the transition plate (4-2) and the base (6), and the clamping mechanism (4-1) and the locking mechanism (4-4) are respectively fastened to the upper side of the transition plate (4-2) and the lower side of the base (6), the aperture of the waist-shaped hole being smaller than the diameter of the nut on the bolt and larger than the diameter of the screw rod of the bolt.

7. The micro-inchworm piezoelectric autofocus device according to claim 3, characterized in that: The driving mechanism (4-3) comprises a second driving foot (4-3-1), a second piezoelectric stack (4-3-2), a second set screw (4-3-3), a second concave rhombus amplifying mechanism (4-3-4) and a second pre-tightening block (4-3-5). The second driving foot (4-3-1) is arranged at a displacement output end on one side of the second concave rhombus amplifying mechanism (4-3-4). The second driving foot (4-3-1) is fixedly connected to the lower surface of the transition plate (4-2). The displacement output end on the other side of the second concave rhombus amplifying mechanism (4-3-4) is fixedly connected to the upper surface of the base (6). A threaded through hole is provided at the non-displacement output end of the second concave rhombus amplifying mechanism (4-3-4). The end of the second set screw (4-3-3) presses against the second pre-tightening block (4-3-5), so that the second piezoelectric stack (4-3-2) maintains pre-tightening contact with the inner side wall of the second concave rhombus amplifying mechanism (4-3-4).

8. The micro-inchworm piezoelectric autofocus device according to claim 1, characterized in that: It also includes a linear bearing (2), which is fixedly installed in a through hole of the fixing mechanism (3), and a guide hole of the linear bearing (2) limits the mover (1) of the inchworm motor to slide in the linear bearing (2).

9. The micro-inchworm piezoelectric autofocus device according to claim 8, characterized in that: The fixing mechanism (3) is provided with two coaxial through holes, and two linear bearings (2) are provided, which are respectively fixedly mounted in the two through holes of the fixing mechanism (3).

10. A driving method for a micro-inchworm piezoelectric autofocus device, based on the micro-inchworm piezoelectric autofocus device according to any one of claims 1 to 9, characterized in that: The driving method comprises the following steps: S1. By adjusting the waist-shaped hole of the locking mechanism (4-4), the third driving foot (4-4-2) is in full contact with the inchworm motor mover (1) and the locking action is completed, ensuring that the inchworm motor mover (1) is in a stationary position; and then by adjusting the positioning structure of the clamping mechanism (4-1), the first driving foot (4-1-2) is within the clamping range; S2. At the initial moment, the instantaneous excitation voltage given to the first piezoelectric stack (4-1-1) of the clamping mechanism (4-1) +A 2 and the instantaneous excitation voltage of the third piezoelectric stack (4-4-1) of the locking mechanism (4-4) +A 3, the first driving foot (4-1-2) of the clamping mechanism (4-1) instantly clamps the inchworm motor mover (1), while the third driving foot (4-4-2) of the locking mechanism (4-4) releases the inchworm motor mover (1); then, the second piezoelectric stack (4-3-2) of the driving mechanism (4-3) is given a voltage from 0 to +A 1 slowly excites the voltage, and at the same time makes the clamping mechanism (4-1) +A 2 Excitation voltage and locking mechanism (4-4) +A 3. The excitation voltage remains unchanged, which causes the driving mechanism (4-3) to extend in the axial direction of the inchworm motor mover (1) and drive the clamping mechanism (4-1) to move. The first driving foot (4-1-2) of the clamping mechanism (4-1) is in full contact with the inchworm motor mover (1), and the maximum static friction force is converted into driving force through the first driving foot (4-1-2), thereby driving the inchworm motor mover (1) to move continuously and smoothly along its axial direction. S3, the second piezoelectric stack (4-3-2) of the driving mechanism (4-3) maintains +A 1, and is maintained at the maximum driving displacement; the excitation voltage of the first piezoelectric stack (4-1-1) of the clamping mechanism (4-1) is changed from +A 2 drops to 0, at which point the first driving foot (4-1-2) of the clamping mechanism (4-1) retracts, releasing the inchworm motor mover (1) to return to a non-contact state, and at the same time the excitation voltage of the third piezoelectric stack (4-4-1) of the locking mechanism (4-4) decreases from +A 3 drops to 0, at which point the third driving foot (4-4-2) of the locking mechanism (4-4) relocks the inchworm motor mover (1), so that the inchworm motor mover (1) remains stationary; S4, the first piezoelectric stack (4-1-1) of the clamping mechanism (4-1) and the third piezoelectric stack (4-4-1) of the locking mechanism (4-4) maintain a 0V excitation voltage, and the state in which the mover (1) of the S3 inchworm motor is locked by the third driving foot (4-4-2) of the locking mechanism (4-4) and is not in contact with the first driving foot (4-1-2) of the clamping mechanism (4-1) is continued; the piezoelectric stack (4-3-2) of the driving mechanism (4-3) is +A 1. The excitation voltage slowly decreases to 0, at which point the driving mechanism (4-3) retracts from the extended state to the initial state, driving the clamping mechanism (4-1) to reset, completing a cycle; S5, loop S1-S4 until the photosensitive element (5) reaches the specified position.

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