WO2020007324A1

WO2020007324A1 - Piezoelectric driver, optical fiber scanning module and projection device

Info

Publication number: WO2020007324A1
Application number: PCT/CN2019/094580
Authority: WO
Inventors: 姚长呈
Original assignee: 成都理想境界科技有限公司
Priority date: 2018-07-06
Filing date: 2019-07-03
Publication date: 2020-01-09
Also published as: CN110690832A; CN110690832B

Abstract

A piezoelectric driver, an optical fiber scanning module and a projection device. The piezoelectric driver includes a piezoelectric body and electrodes, wherein the piezoelectric body is made of a polarized piezoelectric material. Some of the electrodes or all of the electrodes are disposed separately from the piezoelectric body, and the electrodes disposed separately from the piezoelectric body are movably disposed around the piezoelectric body, thereby realizing a change in the direction of a driving force by means of the separately disposed electrodes, realizing compensation for the scanner response, being more flexible and convenient, and improving the imaging quality. In addition, multi-dimensional scanning can also be achieved by means of a pair of electrodes.

Description

Piezo driver, fiber scanning module and projection equipment

This application claims priority from Chinese patent application CN201810739806.0 entitled "A Piezoelectric Actuator, Fiber Scanning Module, and Projection Device" filed on July 6, 2018, the entire contents of which are incorporated herein by reference.

Technical field

The invention relates to the field of optical imaging, in particular to a piezoelectric driver, a fiber scanning module and a projection device.

Background technique

The optical fiber scanning projection imaging system uses a driver to drive the optical fiber at high speed, and cooperates with a laser modulation algorithm to realize the display of image information. In addition, in the existing piezoelectric actuator, the electrodes are closely attached to the piezoelectric ceramic (or other piezoelectric material) by printing or the like. As the actuator body moves together, the direction of the electric field is completely fixed, so the direction of the force is fixed. To achieve two-dimensional scanning, force is required in at least two directions, that is, at least two pairs of electrodes are required.

In addition, in order to achieve maximum amplitude vibration, the optical fiber scanner is generally set to work in a resonance mode, and the scanning characteristics of the optical fiber in a resonant state are complicated. Due to the nonlinear effects of vibration, the symmetry of the optical fiber, the symmetry of the installation of the scanner, and stability, etc., when the vibration amplitude of the fiber in the resonance region is large, the scanning trajectory of the fast axis is no longer an ideal horizontal straight line, and It is a slanted straight line or even an ellipse. According to the literature: High performance, open loop, control, scanning, small, cylindrical, cantilever, beam, Journal of Sound and Vibration 330 (2011) 1762–1771. The results of the study show that: Failure to coincide exactly will cause a non-excitation plane response and affect imaging results. In an ideal state, the vibration performance of a uniformly distributed, perfectly circular cross-section optical fiber in each direction of the radius should be infinitely close. In fact, due to inevitable factors such as processing and gravity, the optical fiber is not perfectly symmetrical, which causes the intrinsic axis to be slightly offset. During the manufacturing process of the scanner, the degree of this offset cannot be accurately determined by installation. The alignment adjustment will result in the response of the non-excitation plane. The slanted straight lines and ellipses caused by the response of the non-excitation plane will seriously affect the imaging quality. This problem needs to be solved urgently.

Summary of the invention

The purpose of the present invention is to provide a piezoelectric driver, a fiber-optic scanning module and a projection device, which solve the problem that the existing piezoelectric driver cannot correct the scanning trajectory deviation by changing the direction of force due to the fixed electric field direction.

In order to achieve the above-mentioned object of the present invention, the present invention provides a piezoelectric actuator, which includes a piezoelectric body and an electrode, the piezoelectric body is a polarized piezoelectric material, and some or all electrodes are provided separately from the piezoelectric body, and An electrode provided separately from the piezoelectric body is disposed around the piezoelectric body in a movable manner.

Preferably, the piezoelectric body is a piezoelectric tube, and the electrode includes an internal electrode and an external electrode. The internal electrode is attached to the inside of the piezoelectric tube, and at least one external electrode is separated from the piezoelectric tube.

Preferably, the piezoelectric driver further includes a casing for packaging the piezoelectric tube, and an external electrode separated from the piezoelectric tube is disposed inside the casing; the casing is rotatable, or the pressure The external electrode separated by the electric tube is slidably disposed inside the casing.

Preferably, the arrangement manner in which the external electrode separated from the piezoelectric tube is slidably arranged on the inner side of the casing includes: providing a guide rail for installing the external electrode on the inner wall of the casing, and symmetrically disposed on the guide rail. The at least one pair of external electrodes slidable along the guide rail.

Preferably, the piezoelectric driver includes two external electrodes, one external electrode is separated from the piezoelectric tube, and one external electrode is fixed with the piezoelectric tube.

Preferably, the piezoelectric driver has only one external electrode and the external electrode is separated from the piezoelectric tube.

Preferably, the piezoelectric tube is a cylindrical piezoelectric tube or a square rod type piezoelectric tube.

Preferably, the piezoelectric tube is a cylindrical piezoelectric tube, and the external electrode separated from the piezoelectric tube is an arc-shaped electrode concentric with the piezoelectric tube.

Preferably, the length of the arc-shaped electrode is consistent with the effective length of the scanner.

Preferably, the piezoelectric body is a piezoelectric tube, and the electrode includes an internal electrode and an external electrode. The external electrode is attached to the outside of the piezoelectric tube, and at least one pair of internal electrodes is separated from the piezoelectric tube.

Preferably, the piezoelectric body has a piezoelectric bimorph structure, and the upper and lower electrodes of the bimorph are separated from the piezoelectric body; the upper and lower electrodes separated from the piezoelectric body are symmetrically disposed on a casing encapsulating the piezoelectric body. Inside; the case can be rotated, or the upper and lower electrodes separated from the piezoelectric body are slidably disposed inside the case.

Preferably, the piezoelectric body has a piezoelectric bimorph structure, and the piezoelectric driver further includes a housing for packaging the piezoelectric body, and at least a pair of compensation electrodes are symmetrically disposed inside the housing; The casing is rotatable, or the compensation electrode is slidably disposed inside the casing.

Preferably, the piezoelectric body is composed of a square rod-shaped substrate and a piezoelectric plate provided on each of the four surfaces of the square rod, and an internal electrode is provided between each piezoelectric plate and the square rod-shaped substrate; the piezoelectric driver only There is a pair of external electrodes separated from the piezoelectric sheet, and the external electrodes are symmetrically arranged inside the casing enclosing the piezoelectric body; the casing can be rotated, or the electrode pairs separated from the piezoelectric body can be slid Is arranged symmetrically on the inside of the casing.

Preferably, the piezoelectric driver further includes an electrode rotation mechanism for driving an electrode separated from the piezoelectric body to rotate.

Correspondingly, the present invention also provides an optical fiber scanning module, which includes an optical fiber and an optical fiber scanning driver, and the optical fiber scanning driver is the aforementioned piezoelectric driver.

Preferably, the optical fiber scanning module further includes a scanning trajectory monitoring module for monitoring the scanned image trajectory and sending monitoring data to a processor of the optical fiber scanning module; the processor calculates a correction parameter based on the monitoring data and instructs The electrode rotation mechanism drives the electrode separated from the piezoelectric body to rotate according to the correction parameter.

Correspondingly, the present invention also provides an optical fiber scanning module, which includes an optical fiber and an optical fiber scanning driver. The optical fiber scanning driver is a piezoelectric driver with only one external electrode in the piezoelectric driver according to the claim. The piezoelectric driver is also It includes an electrode rotation mechanism for driving the electrode separated from the piezoelectric body to rotate at high frequency, and the two-dimensional scanning of a pair of electrodes is realized according to the driving voltage change of the piezoelectric driver.

Correspondingly, the present invention also provides a projection device, which includes the optical fiber scanning module as described above.

Compared with the prior art, the present invention has the following beneficial effects:

Some or all of the electrodes of the piezoelectric actuator of the present invention are provided separately from the piezoelectric body, and the electrodes provided separately from the piezoelectric body are disposed around the piezoelectric body in a movable manner, so that the driving force direction can be achieved by separating the electrodes. The change can realize the compensation of the scanner response, flexibility and convenience, and improve the imaging quality. In addition, it can also realize a multi-dimensional scanning of a pair of electrodes, which provides a new idea for future research in the field of fiber scanning.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly explain the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are merely These are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without paying creative labor:

1 is a first structural diagram of a cylindrical tubular piezoelectric driver according to an embodiment of the present invention;

2 is a second structural schematic diagram of a cylindrical tubular piezoelectric driver according to an embodiment of the present invention;

3 is a schematic cross-sectional view of a third structure of a cylindrical tubular piezoelectric actuator according to an embodiment of the present invention;

4 is a fourth structural schematic diagram of a cylindrical tubular piezoelectric driver according to an embodiment of the present invention;

5 is a schematic structural diagram of a square rod-shaped tubular piezoelectric driver according to an embodiment of the present invention;

6 is a schematic structural diagram of another square rod type piezoelectric driver according to an embodiment of the present invention;

FIG. 7 is a schematic diagram of a result of a fiber scanning driver according to an embodiment of the present invention.

Marked in the picture: 10-cylindrical piezoelectric tube, 11-drive body, 12-square rod piezoelectric tube, 21 \ 27-internal electrode, 22 \ 23 \ 24 \ 25 \ 26-outer electrode, 30 \ 31 shell Body, 41 \ 42-driver pole, 61-piezo sheet, 5-fiber, 6-base.

detailed description

In the following, the technical solutions in the embodiments of the present invention will be clearly and completely described with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by a person of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

The inventors of the present invention have found that the electrodes of existing piezoelectric drivers, especially those used for optical fiber scanning, are tightly attached to piezoelectric ceramics (or other piezoelectric materials) by printing or the like. As the actuator body moves together, the direction of its electric field is completely fixed. The inventor of the present invention found that the piezoelectric material itself is an insulator, which causes mechanical deformation due to the action of the electric field. Its mechanism is directly related to the electric field strength only, and does not need to be directly related to Electrode contact, so the present invention proposes that some or all of the electrodes of the piezoelectric driver can be separated from the piezoelectric body to achieve an adjustable driving force or a pair of electrodes to achieve multi-dimensional scanning, which provides a new type of research in the field of fiber scanning. Of ideas. The embodiments of the present invention will be described in detail below with reference to the drawings.

The piezoelectric actuators of all embodiments of the present invention include a piezoelectric body and an electrode. The piezoelectric body is a polarized piezoelectric material. The difference between the present invention and the prior art is that the piezoelectric actuator of the present invention Some or all of the electrodes are provided separately from the piezoelectric body, and the electrodes provided separately from the piezoelectric body are disposed around the piezoelectric body in a movable manner (movable means such as translation, offset or rotation), so that The separation electrode realizes the change of the driving force direction, realizes the scanner response compensation, is flexible and convenient, and improves the imaging quality.

In all embodiments of the present invention, the shape and length of the electrodes separated from the piezoelectric body are not limited, and the length can be set to be adjustable. In addition, the number of separation electrodes is not limited, and can be formulated according to actual use requirements.

Referring to FIGS. 1 to 4, it is an implementation manner of a cylindrical tubular piezoelectric actuator in the embodiment of the present invention. In the embodiment of FIGS. 1 to 4, the piezoelectric body is a cylindrical piezoelectric tube 10, and its polarization direction is along a radius. direction.

In the embodiment of FIG. 1, the piezoelectric actuator has only one external electrode and the external electrode is separated from the piezoelectric tube. Referring to FIG. 1, the internal electrode 21 is attached inside the piezoelectric tube, and the external electrode 22 and the external electrode 23 are external electrodes. The two are separated from the cylindrical piezoelectric tube 10, and are arranged around the piezoelectric body in any movable manner. The driving voltage is applied to the

external electrodes

22 and 23 synchronously according to the polarization direction of the cylindrical piezoelectric tube 10. The piezoelectric tube 10 is driven by the electric field between the inner and outer electrodes. In the embodiments of FIGS. 1 to 4, since the piezoelectric body is a cylindrical piezoelectric tube, in order to make the effective driving area larger and ensure a better driving effect, a preferred embodiment is: The separated external electrodes are arc-shaped electrodes that are concentric with the piezoelectric tube. See FIG. 1 to FIG. 4, which are all illustrated as concentric arc-shaped electrodes. In terms of the length direction, a preferred method is that the length of the arc-shaped electrode is consistent with the effective length of the scanner.

The embodiment of FIG. 2 adds an external electrode (external electrodes 24, 25) on the basis of the embodiment of FIG. As shown in FIG. 2, the

external electrodes

24 and 25 are attached to the external surface of the piezoelectric tube, and the

external electrodes

22 and 23 are separated from the external surface of the piezoelectric tube.

It should be noted that the external electrodes separated from the piezoelectric tube in FIG. 1 and FIG. 2 can be arranged at a certain distance from the outer surface of the piezoelectric tube in any movable or rotatable manner. For example, the separated external electrodes can be set In the inside of the housing for packaging the piezoelectric tube, in order to realize the separation of the external electrodes to be rotatable, a structure in which the separation external electrodes are fixed to the inside of the housing and the housing is rotatable may be adopted. In another embodiment, a separate external electrode may also be provided on the inside of the casing in a slidable manner. As shown in FIG. 3, FIG. 3 is a diagram illustrating a case 30 in which the piezoelectric tube is packaged and added on the basis of FIG. 2, and the

external electrodes

22 and 23 are disposed inside the case 30. In one embodiment, the

external electrodes

22 and 23 are fixed inside the casing 30, and the casing 30 can rotate. In another embodiment, a guide rail for mounting external electrodes is provided on the inner wall of the casing 30 (not shown in FIG. 3). Out of the guide rail), and separate external electrodes that can be slid along the guide rail are symmetrically arranged on the guide rail. Among them, FIG. 3 is based on the external electrode of FIG. 2 as an example. When there are multiple pairs of external electrodes separated from the piezoelectric tube, the corresponding processing can be performed in the same manner. In the embodiment of using a guide rail to separate the external electrodes, each The external electrode can share a guide rail, or each external electrode can use a separate guide rail. When there are multiple pairs of external electrodes separated from the piezoelectric tube, multiple guide rails can be set according to the needs or a single guide rail can be shared. No restrictions.

1 to 3 are examples of separating external electrodes. As an alternative, in practice, all external electrodes may be attached to the outside of the piezoelectric tube, and at least one pair of internal electrodes may be separated from the piezoelectric tube, as shown in FIG. 4. As shown in FIG. 4, four external electrodes 26 are attached to the outside of the cylindrical piezoelectric tube 10, and a pair of internal electrodes 27 are separated from the inside of the piezoelectric tube. Similarly, a pair of internal electrodes 27 are provided in any movable manner. Around the piezoelectric body.

The above-mentioned FIGS. 1 to 4 all take the cylindrical piezoelectric tube as an example, and the piezoelectric tube in the embodiment of the present invention may also have other shapes, such as a square rod-type piezoelectric tube or other polygonal piezoelectric tubes. As shown in FIG. 5, the cylindrical piezoelectric tube 10 shown in FIGS. 1 to 4 is replaced with a square rod-shaped piezoelectric tube 12. Similarly, in FIG. 5, the internal electrode 21 is attached inside the square rod-shaped piezoelectric tube. The

external electrodes

22 and 23 are symmetrically disposed inside the casing 30, and the casing 30 can be rotated, or the

external electrodes

22 and 23 are slidably disposed inside the casing 30. In FIG. 5, an external electrode attached to the outer surface may be provided on the outer surface of the square rod-shaped piezoelectric tube 12, or an external electrode attached to the outer surface may not be provided on the outer surface of the square rod-shaped piezoelectric tube 12.

FIG. 6 is another embodiment of a square rod-type piezoelectric structure according to the present invention. The piezoelectric body in FIG. 6 is composed of a square rod-shaped substrate 25 and a piezoelectric sheet 61 provided on each of four surfaces of the square rod. An internal electrode is provided between the sheet and the square rod-shaped substrate; the piezoelectric driver only has a pair of

external electrodes

22, 23 separated from the piezoelectric sheet, and the external electrodes (22, 23) are symmetrically arranged to encapsulate the piezoelectric The housing 30 is inside the body; the housing 30 is rotatable or is slidably disposed inside the housing 30 symmetrically with the

electrodes

22 and 23.

In addition, the piezoelectric body in the embodiment of the present invention may also be a piezoelectric bimorph structure (the upper and lower surfaces of the bimorph structure are still provided with electrodes), and at least a symmetrical structure may be provided on the inner side of the housing for packaging the piezoelectric body. A pair of compensation electrodes are used to apply a voltage to form a compensation electric field; the casing can be rotated, or the compensation electrodes are slidably disposed inside the casing. In another embodiment, when the piezoelectric actuator is manufactured, the upper and lower electrodes of the dual wafer can be removed (where the upper and lower electrodes of the dual wafer refer to the upper electrode of the upper wafer and the lower electrode of the lower wafer). An external electrode is symmetrically arranged on the inside of the casing enclosing the piezoelectric body; the casing is rotatable, or the upper and lower electrodes separated from the piezoelectric body are slidably disposed on the inside of the casing.

In all the above-mentioned embodiments, it is required that the electrodes provided separately are arranged around the piezoelectric body in a movable manner. Then, it can be understood that the piezoelectric actuator of the present invention further includes an electrode rotating mechanism (not shown in the drawings). The electrode separated from the piezoelectric body is directly or indirectly driven to rotate. When the separation electrode is immovably fixed to the inside of the package case, the electrode rotation mechanism can indirectly drive the selection of the separation electrode by driving the package case to rotate; when the separation electrode is slidably fixed to the inside of the package case, the electrode rotation mechanism The electrode can be directly driven to rotate inside the casing, and the method is not limited.

The piezoelectric driver in the embodiment of the present invention is particularly suitable for being used as a fiber scanning driver in fiber scanning. Therefore, the present invention also proposes a fiber scanning module including a fiber and a fiber scanning driver. The fiber scanning driver is the present invention. The proposed piezoelectric actuator.

Since some or all of the electrodes of the piezoelectric actuator of the present invention are provided separately from the piezoelectric body, and the electrodes provided separately from the piezoelectric body are disposed around the piezoelectric body in a movable manner, the driving force direction can be achieved by separating the electrodes. Change. Therefore, the separation electrode can be used as a correction structure. In one embodiment, a scanning trajectory monitoring module can be set in the fiber scanning module, which is used to monitor the scanning of the image trajectory by the fiber scanning module and send monitoring data to the processing of the fiber scanning module. The processor calculates a correction parameter according to the monitoring data, and instructs the electrode rotation mechanism to drive the electrode separated from the piezoelectric body to rotate according to the correction parameter. For example, when the ellipse deformation caused by the response of the non-excitation plane occurs during the optical fiber scanning, the processor analyzes the monitoring data and determines that the scanned image trajectory is an elliptical trajectory. Calculate a correction parameter and instruct the electrode rotation mechanism to drive the external electrode to rotate according to the correction parameter. More specifically, when the driving body is a cylindrical piezoelectric tube, the deviation angle is determined according to the direction of the long axis of the ellipse, and at the same time, the separated external electrode is rotated by the corresponding angle, so that the driving force coincides with the intrinsic direction, and the The drive trajectory of the fast axis is corrected to a straight line. (Refer to High Performance, Open Loop Control, Scanning, Scanning, Small, Cantilever, Beam, Journal of Sound and Vibration 330 (2011) 1762–1771. If the direction of the driving force coincides with the eigen direction, no ellipse will occur. )

The embodiment of the present invention also proposes another fiber scanning module, which includes an optical fiber and a fiber scanning driver. The fiber scanning driver may be a piezoelectric driver provided in the embodiment of FIG. 1 or FIG. 5. The separation electrode rotates at a higher frequency. The change of the driving voltage can only use this pair of electrodes to achieve two-dimensional scanning, including but not limited to grid, Lisaru, and spiral scanning methods. For example, when Lisaru scans, the electrode rotation frequency does not change. Rotation is performed below the lower scanning frequency of the driving frequency in both directions (tens of kilohertz), so that the driving force is switched back and forth in the direction of the slow and fast axis to realize the two-dimensional driving function; when used as grid scanning, the electrode rotation frequency does not change. Below the frame frequency (tens of hertz or hundred hertz level), the driving force is switched back and forth in the direction of the slow axis to realize the two-dimensional driving function; when used as a spiral scan, the electrode rotation frequency is not lower than the scan frequency of the fast axis to rotate ( Tens of kilohertz), the driving force is switched back and forth in the direction of the slow axis, and the two-dimensional driving function is realized. For other scanning modes, you can refer to the analogy. It is worth mentioning that when a single electrode realizes two-dimensional scanning driving, the scanner does not feel constant force but impact force, which will make an impulse decay response. Each cycle provides an impact force (provided by electrode rotation) ), In order to maintain the scanner's amplitude at the target value, and cooperate with the adjustment of the impact force (by driving voltage or magnetic force), the purpose of adjusting the scanning amplitude can be achieved.

Based on the same idea of the above-mentioned piezoelectric driver, the material of the optical fiber scanning driver in the above embodiment may not be a piezoelectric material, or a material that can be magnetically adsorbed, etc., and the electrode accordingly becomes a driving electrode that provides magnetic force. Under the action of a periodically changing magnetic force, a unipolar drive is used to implement the scanning function, or a variable direction unipolar drive is used to implement the trajectory compensation function.

Referring to FIG. 7, FIG. 7 is a schematic structural diagram of a fiber scanning driver according to an embodiment of the present invention. The fiber scanning driver according to the embodiment of the present invention includes a housing 31, a driving body 11, and driving

poles

41 and 42. The driving body 11 Encapsulated in the casing 31, the driving

poles

41 and 42 are arranged inside the casing 31 (the number of driving poles can be multiple and the number is not limited, as shown in FIG. 7 with one pair of driving poles). The casing 31 can be rotated or the driving

poles

41 and 42 can be slidably arranged inside the casing 31. The sliding manner can also be a guide rail. For details, refer to the foregoing description of the piezoelectric driver. When the fiber scanning driver is applied to a fiber scanning module, one end of the driving body 11 is fixed on the base 6 and the other end forms a free end. The optical fiber 5 is fixed on the driving body 11 and extends along the free end of the driving body 11. Cantilever extends in the direction. In FIG. 7, when the driving body 11 is a magnet, the driving

poles

41 and 42 are magnets; when the driving body 11 is a piezoelectric material, the driving

poles

41 and 42 are electrodes. When the driving body 11 is a magnetic body, the descriptions of the piezoelectric driver embodiments can be applied to the arrangement of the driving poles, the driving pole rotation mechanism, and the scanning trajectory detection module of the scanning module. The difference lies only in the choice of the material of the driving body and the driving electrode, which results in different swinging principles, and the other is no different.

An embodiment of the present invention further provides a projection device, which may be an optical fiber scanning module provided by each embodiment of the present invention.

The invention proposes that some or all of the electrodes of the piezoelectric actuator can be separated from the piezoelectric body to achieve an adjustable driving direction, which can realize the compensation of the scanner response, is flexible and convenient, and can effectively improve the imaging quality. In addition, the invention proposes The piezoelectric actuator can also realize a multi-dimensional scanning of a pair of electrodes, which provides a new idea for future research in the field of fiber scanning. At the same time, the present invention also proposes that the idea of the present invention can be extended to an electromagnetic driver, and the driving pole can be set to be movable or rotatable to achieve the same function and effect.

All features disclosed in this specification, or all disclosed methods or steps, other than mutually exclusive features and / or steps, may be combined in any manner.

Any feature disclosed in this specification (including any additional claims, abstract and drawings), unless specifically stated otherwise, may be replaced by other equivalent or similar purpose alternative features. That is, unless specifically stated, each feature is just one example of a series of equivalent or similar features.

The invention is not limited to the foregoing specific embodiments. The invention extends to any new feature or any new combination disclosed in this specification, and to any new method or process step or any new combination disclosed.

Claims

A piezoelectric actuator includes a piezoelectric body and an electrode. The piezoelectric body is a polarized piezoelectric material, and is characterized in that some or all of the electrodes are separated from the piezoelectric body and separated from the piezoelectric body. The electrodes are arranged around the piezoelectric body in a movable manner.
The piezoelectric actuator according to claim 1, wherein the piezoelectric body is a piezoelectric tube, the electrode includes an internal electrode and an external electrode, and the internal electrode is attached inside the piezoelectric tube, and at least one of the external electrode and the pressure Electric tube is separated.
The piezoelectric actuator according to claim 2, characterized in that the piezoelectric actuator further comprises a casing for packaging the piezoelectric tube, and an external electrode separated from the piezoelectric tube is disposed inside the casing; The casing is rotatable, or the external electrode separated from the piezoelectric tube is slidably disposed inside the casing.
The piezoelectric actuator according to claim 3, wherein the arrangement of the external electrode separated from the piezoelectric tube in a slidable manner on the inner side of the casing comprises: disposing on an inner wall of the casing At least one pair of external electrodes that can be slid along the guide rail are symmetrically arranged on the guide rail for mounting the external electrode.
The piezoelectric actuator according to claim 3, wherein the piezoelectric actuator comprises two external electrodes, one external electrode is separated from the piezoelectric tube, and one external electrode is fixed to the piezoelectric tube.
The piezoelectric actuator according to claim 3, wherein the piezoelectric actuator has only one external electrode and the external electrode is separated from the piezoelectric tube.
The piezoelectric actuator according to any one of claims 2 to 6, wherein the piezoelectric tube is a cylindrical piezoelectric tube or a square rod type piezoelectric tube.
The piezoelectric actuator according to claim 7, wherein the piezoelectric tube is a cylindrical piezoelectric tube, and the external electrode separated from the piezoelectric tube is an arc-shaped electrode concentric with the piezoelectric tube.
The piezoelectric actuator according to claim 8, wherein the length of the arc-shaped electrode is consistent with the effective length of the scanner.
The piezoelectric actuator according to claim 1, wherein the piezoelectric body is a piezoelectric tube, and the electrode includes an internal electrode and an external electrode, and the external electrode is attached to the outside of the piezoelectric tube, and at least one pair of the internal electrode and The piezo tube is separated.
The piezoelectric actuator according to claim 1, wherein the piezoelectric body has a piezoelectric bimorph structure, and the upper and lower electrodes of the bimorph are separated from the piezoelectric body; and the upper and lower electrodes are separated from the piezoelectric body. It is arranged symmetrically inside the casing enclosing the piezoelectric body; the casing is rotatable, or the upper and lower electrodes separated from the piezoelectric body are slidably disposed inside the casing.
The piezoelectric actuator according to claim 1, wherein the piezoelectric body has a piezoelectric bimorph structure, and the piezoelectric driver further comprises a housing for packaging the piezoelectric body, and the housing At least one pair of compensation electrodes is symmetrically arranged on the inside of the body; the casing can be rotated, or the compensation electrodes are slidably arranged on the inside of the casing.
The piezoelectric actuator according to claim 1, wherein the piezoelectric body is composed of a square rod-shaped substrate and a piezoelectric plate provided on each of four surfaces of the square rod, and each of the piezoelectric plates and the square rod-shaped substrate An internal electrode is provided between the piezoelectric actuators; the piezoelectric actuator only has a pair of external electrodes separated from the piezoelectric sheet, and the external electrodes are symmetrically arranged inside the casing encapsulating the piezoelectric body; the casing can be rotated, or The electrode pairs separated by the piezoelectric body are symmetrically disposed inside the casing in a slidable manner.
The piezoelectric driver according to any one of claims 1 to 12, wherein the piezoelectric driver further comprises an electrode rotation mechanism for driving an electrode separated from the piezoelectric body to rotate.
An optical fiber scanning module includes an optical fiber and an optical fiber scanning driver, wherein the optical fiber scanning driver is a piezoelectric driver according to claim 14.
The fiber optic scanning module according to claim 15, wherein the fiber optic scanning module further comprises a scanning trajectory monitoring module for monitoring the scanning image trajectory and sending monitoring data to a processor of the optical fiber scanning module; The processor calculates a correction parameter according to the monitoring data, and instructs the electrode rotation mechanism of the pressure driver to drive the electrode separated from the piezoelectric body to rotate according to the correction parameter.
An optical fiber scanning module includes an optical fiber and an optical fiber scanning driver, wherein the optical fiber scanning driver is the piezoelectric driver according to claim 6 or 13; the piezoelectric driver further includes an electrode rotating mechanism for: The electrode separated from the piezoelectric body is driven to rotate at a high frequency, and a two-dimensional scanning of a pair of electrodes is realized according to a change in driving voltage of the piezoelectric driver.
A projection device, characterized in that the projection device comprises the optical fiber scanning module according to any one of claims 15 to 17.