A scanning actuator and fiber scanner
By using a scanning actuator design with two piezoelectric plates and three electrode layers sintered together, the challenges of batch production consistency and processing were solved, resulting in an easy-to-process and high-efficiency fiber optic scanner that reduces vibration coupling and power consumption.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- CHENGDU IDEALSEE TECH
- Filing Date
- 2023-11-30
- Publication Date
- 2026-08-04
AI Technical Summary
Existing scanning actuators are difficult to make consistent and easy to manufacture during mass production, making it difficult to mass-produce irregularly shaped structures.
The scanning actuator design, which uses two piezoelectric plates and three electrode layers sintered together, simplifies the manufacturing process. It achieves horizontal and vertical vibration by controlling the synchronous reverse extension and retraction of the piezoelectric plates through a drive signal. The fiber optic mounting hole ensures symmetry and positioning.
This achieves easy fabrication and consistency in mass production of scanning actuators, reduces vibration coupling and power consumption, and improves the imaging quality of fiber optic scanners.
Smart Images
Figure CN224594918U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of fiber optic scanning display technology, and in particular to a scanning actuator and a fiber optic scanner. Background Technology
[0002] A fiber optic scanner is a display technology that uses a scanning actuator to control the oscillation of an optical fiber to emit a pattern. The pattern emitted by this technology has sharp and saturated colors, high contrast, high brightness, and a very small structural size.
[0003] The actuator of a grid-type fiber optic scanner mainly consists of a second actuator as the fast axis and a first actuator as the slow axis. Both the second and first actuators have a fixed end and a free end, respectively, with the fixed end of the second actuator fixedly connected to the free end of the first actuator. To obtain a stable scanning range and precisely control the scanning trajectory, the scanning trajectory at the actuator's end must be precisely consistent with the scanning trajectories of the first and second actuators. Any machining error in the actuator will make the actuator's vibration difficult to control or generate chaotic vibration components.
[0004] Traditional scanner actuators are generally tubular or plate-shaped. In order to ensure that the actuator in the slow axis direction meets the slow axis scanning frequency and the actuator in the fast axis direction meets the fast axis scanning frequency, the shape and size of the actuator must be designed accordingly, which results in the actuator being an irregular shape.
[0005] For example, Chinese patent CN111830702A discloses a scanning actuator that generally uses a tubular piezoelectric actuator. However, due to the aforementioned constraints, its design results in an irregular shape, which is quite disadvantageous for mass production of the actuator, making it difficult to manufacture and compromising manufacturing consistency. Similarly, Chinese patent CN209784655U discloses a scanning actuator that generally uses a sheet-like piezoelectric actuator. Again, for performance reasons, the actuator is also designed as an irregular shape, similarly suffering from the aforementioned technical problems of difficult precision manufacturing and poor manufacturing consistency.
[0006] Therefore, how to make the actuator easy to manufacture, easy to mass-produce, and have good consistency in mass production, while ensuring that each actuating part meets the performance parameters, is a technical problem that needs to be solved. Utility Model Content
[0007] This utility model provides a scanning actuator and a fiber optic scanner to at least solve the technical problems of actuators being difficult to mass-produce and having poor consistency in mass production.
[0008] To achieve the aforementioned utility model objectives, the first aspect of this utility model provides a scanning actuator, comprising an actuator body integrally formed by sintering. The actuator body includes a lower electrode layer, a lower piezoelectric sheet, a middle electrode layer, an upper piezoelectric sheet, and an upper electrode layer arranged sequentially from bottom to top. The extension direction of the piezoelectric sheet is taken as the horizontal plane direction, and the front end of the actuator body is taken as the free vibration end. An optical fiber mounting hole is machined at the center of the front end face of the actuator body, penetrating the actuator body in the front-rear direction. The optical fiber mounting hole divides the middle electrode layer into a left electrode layer and a right electrode layer that are independent of each other. The upper and lower piezoelectric sheets are both polarized in the vertical direction. Under the drive of a driving signal, the upper and lower piezoelectric sheets synchronously extend and retract in opposite directions to drive the free vibration end to vibrate in the vertical direction. At the same time, the left side and the right side of the upper and lower piezoelectric sheets synchronously extend and retract in opposite directions to drive the free vibration end to vibrate left and right in the horizontal direction.
[0009] This invention is made of two piezoelectric sheets and three electrode layers sintered together. It does not require adhesives or other additional materials, which simplifies the production process and facilitates mass production. After sintering, only one step is required to process the through-hole for the optical fiber installation. It is easy to process and ensures the consistency of product specifications, performance and parameters in mass production.
[0010] Preferably, the upper and lower piezoelectric sheets are completely identical in shape and size and completely overlap. The lower electrode layer, the middle electrode layer (before processing the fiber mounting hole), and the upper electrode layer all completely cover the corresponding surfaces of the piezoelectric sheets, so that the scanning actuator can obtain good precision symmetry and ensure that both vertical and horizontal vibrations are linear.
[0011] Since the left and right electrode layers are independent of each other, the left and right sides of the upper piezoelectric sheet body form a first left driving region and a first right driving region symmetrically arranged, and the left and right sides of the lower piezoelectric sheet body form a second left driving region and a second right driving region symmetrically arranged. The first left driving region and the second left driving region are vertically symmetrical, and the first right driving region and the second right driving region are vertically symmetrical.
[0012] Preferably, under the drive signal: the first left drive region and the first right drive region perform a first synchronous equal-length extension and retraction action, the second left drive region and the second right drive region perform a second synchronous equal-length extension and retraction action, and the first synchronous extension and retraction action and the second synchronous extension and retraction action are synchronous, equal in length and opposite in direction; at the same time, the first left drive region and the second left drive region perform a third synchronous equal-length extension and retraction action, the first right drive region and the second right drive region perform a fourth synchronous equal-length extension and retraction action, and the third synchronous extension and retraction action and the fourth synchronous extension and retraction action are synchronous, equal in length and opposite in direction.
[0013] Preferably, the upper and lower piezoelectric sheets have the same polarization direction. The upper electrode layer is connected to a first power signal, the lower electrode layer is connected to a second power signal, the left electrode layer is connected to a first drive signal, and the right electrode layer is connected to a second drive signal. The first and second power signals can be either positive or negative power signals, and the polarities of the first and second power signals are opposite.
[0014] Furthermore, both the first and second driving signals employ a frequency mixing driving method, causing the dual crystals to vibrate at different frequencies in the vertical and horizontal directions, respectively.
[0015] Specifically, the first driving signal is:
[0016] SIgL=Fy(2πωyt+ɸyL)+Axcsin(2πωxt+ɸxcL)+Axsin(2πωxt+ɸxL),
[0017] The second driving signal is:
[0018] SIgR= Fy(2πωyt+ɸyR)+Axcsin(2πωxt+ɸxcR)+Axsin(2πωxt+ɸxR).
[0019] Axsin(2πωxt+ɸxL) / Axsin(2πωxt+ɸxR) are high-frequency drive signals in the left-right direction (X-direction), which can be sine waves or other waveforms depending on the application requirements. Ideally, the difference between ɸxL and ɸxR is 180°. In practical applications, due to processing precision, there are slight differences in the response characteristics of the left and right sides of the dual-wafer system. Appropriately adjusting the difference between ɸxL and ɸxR ensures that the deformations on the left and right sides are strictly out of phase, achieving maximum deformation and minimum vertical component. Ax represents the voltage amplitude of the control signals Axsin(2πωxt+ɸxL) and Axsin(2πωxt+ɸxR), ɸxL represents the initial phase of the control signal Axsin(2πωxt+ɸxL), and ɸxR represents the initial phase of the control signal Axsin(2πωxt+ɸxR).
[0020] Fy(2πωyt+ɸyL) / Fy(2πωyt+ɸyR) is a low-frequency drive signal in the vertical direction (Y direction), which can be a sine wave or other waveforms depending on the application requirements. Ideally, the signal components in SIgL / SIgR signals are completely identical, i.e., ɸyL=ɸyR. In practical applications, due to processing precision, there are slight differences in the response characteristics of the upper and lower sides of the dual wafers. Appropriately adjusting the difference between ɸyL and ɸyR makes the deformation on the upper and lower sides strictly out of phase, in order to achieve the maximum deformation and the minimum vertical component. Fy is the voltage amplitude of the control signals Fy(2πωyt+ɸyL) and Fy(2πωyt+ɸyR), ɸyL is the initial phase of the control signal Fy(2πωyt+ɸyL), and ɸyR is the initial phase of the control signal Fy(2πωyt+ɸyR).
[0021] Axcsin(2πωxt+ɸxcL) / Axcsin(2πωxt+ɸxcR) is the X-direction correction signal, used to correct the Y-direction component of the fast-axis trajectory to zero, making its trajectory a closed trajectory. Ideally, in the SIgL / SIgR signals, these signal components are completely identical, i.e., ɸxcL=ɸxcR. Axc is the voltage amplitude of the control signals Axcsin(2πωxt+ɸxcL) and Axcsin(2πωxt+ɸxcR), ɸxcL is the initial phase of the control signal Axcsin(2πωxt+ɸxcL), and ɸxcR is the initial phase of the control signal Axcsin(2πωxt+ɸxcR).
[0022] A second aspect of this utility model provides an optical fiber scanner, including a scanning actuator and an optical fiber as described above. The optical fiber is fixedly inserted into the optical fiber mounting hole, and the light-emitting end of the optical fiber passes through the free vibration end of the scanning actuator to form an optical fiber cantilever. The portion of the optical fiber located on the rear side of the optical fiber cantilever is fixedly connected to the scanning actuator.
[0023] One or more technical solutions in the embodiments of this utility model have at least the following technical effects or advantages:
[0024] This invention comprises two piezoelectric sheets and three electrode layers sintered together, requiring no adhesives or other additional materials. This simplifies the manufacturing process and facilitates mass production. After sintering, only one step is needed to machine the through-hole for the optical fiber mounting, making it easy to process. In mass production, it is easy to ensure consistency in product specifications, performance, and parameters. For fiber optic scanning imaging technology, good actuator consistency is one of the key factors enabling the mass production of fiber optic scanners. Furthermore, the sheet-like structure results in a large difference in the characteristic frequency values of the actuator in the horizontal and vertical directions. When the scanning actuator is used in grid scanning mode, it can greatly reduce vibration coupling in the two vibration directions.
[0025] The manufacturing process of machining a center hole at the center after integral sintering ensures the overall symmetry of the structure (left-right symmetry and top-bottom symmetry). The upper and lower double wafers share the same electrode, which can maximize the consistency of the upper and lower piezoelectric ceramic wafers on the same side (left or right side), ensuring that there is no vertical component when it is used for horizontal driving.
[0026] Meanwhile, the presence of fiber mounting holes effectively reduces the equivalent stiffness of the left and right segmented regions of the actuator body, thereby reducing stress concentration in the segmented regions and appropriately increasing the horizontal bending amplitude of the bicrystalline wafers, thus reducing power consumption. The fiber mounting holes also serve a positioning function during fiber assembly, ensuring that the fiber is strictly centered within the bicrystalline wafers. This effectively prevents significant bending of the bicrystalline wafers during fiber bonding, avoiding interference caused by modulus mismatch between the fiber and the ceramic sheet, which could lead to nonlinear vibration responses. Attached Figure Description
[0027] Figure 1 This is a schematic diagram of the structure of the fiber optic scanner of this utility model;
[0028] Figure 2 This is a schematic diagram of the end face structure of the scanning actuator;
[0029] Figure 3 This is a schematic diagram of the drive region distribution structure of the scanning actuator.
[0030] Figure 4 This is a schematic diagram of the drive signal connection for the scanning actuator. Detailed Implementation
[0031] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.
[0032] like Figure 1 , Figure 2As shown, the first aspect of this utility model provides a scanning actuator, including an actuator body 100 integrally formed by sintering. The actuator body 100 includes a lower electrode layer 101, a lower piezoelectric sheet 102, a middle electrode layer, an upper piezoelectric sheet 103, and an upper electrode layer 104 arranged sequentially from bottom to top. The extension direction of the piezoelectric sheet is taken as the horizontal plane direction, and the front end of the actuator body 100 is taken as the free vibration end. An optical fiber penetrating the actuator body 100 in the front-to-back direction is processed at the center position of the front end face of the actuator body 100. The mounting hole 107 divides the middle electrode layer into two independent left electrode layers 105 and right electrode layers 106. The upper piezoelectric sheet 103 and the lower piezoelectric sheet 102 are both polarized in the vertical direction. Under the drive signal, the upper piezoelectric sheet 103 and the lower piezoelectric sheet 102 synchronously extend and retract in opposite directions to drive the free vibration end to vibrate in the vertical direction. At the same time, the left side of the upper piezoelectric sheet 103 and the right side of the lower piezoelectric sheet 102 synchronously extend and retract in opposite directions to drive the free vibration end to vibrate left and right in the horizontal direction.
[0033] This invention comprises two piezoelectric sheets and three electrode layers sintered together, requiring no adhesives or other additional materials. This simplifies the manufacturing process and facilitates mass production. After sintering, only one step is needed to machine the through-hole fiber mounting hole 107, making it easy to process. In mass production, it is easy to ensure consistency in product specifications, performance, and parameters. For fiber optic scanning imaging technology, good actuator consistency is one of the key factors enabling the mass production of fiber optic scanners. Simultaneously, the sheet-like structure results in a large difference in the characteristic frequency values of the actuator in the horizontal and vertical directions. When the scanning actuator is used in grid scanning mode, it can greatly reduce vibration coupling in the two vibration directions.
[0034] The manufacturing process of machining a center hole at the center after integral sintering ensures the overall symmetry of the structure (left-right symmetry and top-bottom symmetry). The upper and lower double wafers share the same electrode, which can maximize the consistency of the upper and lower piezoelectric ceramic wafers on the same side (left or right side), ensuring that there is no vertical component when it is used for horizontal driving.
[0035] Meanwhile, the presence of fiber mounting holes effectively reduces the equivalent stiffness of the left and right segmented regions of the actuator body, thereby reducing stress concentration in the segmented regions and appropriately increasing the horizontal bending amplitude of the bicrystalline wafers, thus reducing power consumption. The fiber mounting holes also serve a positioning function during fiber assembly, ensuring that the fiber is strictly centered within the bicrystalline wafers. This effectively prevents significant bending of the bicrystalline wafers during fiber bonding, avoiding interference caused by modulus mismatch between the fiber and the ceramic sheet, which could lead to nonlinear vibration responses.
[0036] The electrode layer is an ultrathin metallic conductive layer, typically with a thickness of less than 10 μm.
[0037] Preferably, the upper piezoelectric sheet 103 and the lower piezoelectric sheet 102 have the same shape and size and completely overlap. The lower electrode layer 101, the middle electrode layer (before processing the fiber mounting hole 107), and the upper electrode layer 104 completely cover the corresponding surfaces of the piezoelectric sheets, so that the scanning actuator can obtain good precision symmetry and ensure that both vertical and horizontal vibrations are linear.
[0038] Since the left and right electrode layers are independent of each other, correspondingly, such as Figure 3 As shown, the upper piezoelectric sheet 103 has a first left driving region 301 and a first right driving region 302 symmetrically arranged on the left and right sides of its body, and the lower piezoelectric sheet 102 has a second left driving region 303 and a second right driving region 304 symmetrically arranged on the left and right sides of its body. The first left driving region and the second left driving region 303 are vertically symmetrical, and the first right driving region 302 and the second right driving region 304 are vertically symmetrical.
[0039] Preferably, under the drive signal: the first left drive region 301 and the first right drive region 302 perform a first synchronous equal-length extension and retraction action, the second left drive region 303 and the second right drive region 304 perform a second synchronous equal-length extension and retraction action, and the first synchronous extension and retraction action and the second synchronous extension and retraction action are synchronous, equal in length and opposite in direction; at the same time, the first left drive region 301 and the second left drive region 303 perform a third synchronous equal-length extension and retraction action, the first right drive region 302 and the second right drive region 304 perform a fourth synchronous equal-length extension and retraction action, and the third synchronous extension and retraction action and the fourth synchronous extension and retraction action are synchronous, equal in length and opposite in direction.
[0040] Specifically, when the first left-side driving region 301 and the first right-side driving region 302 extend synchronously, the second left-side driving region 303 and the second right-side driving region 304 contract synchronously, and the extension and contraction amounts are consistent, thus causing the free vibration end to move downwards in the vertical direction; conversely, the free vibration end moves upwards in the vertical direction, thereby achieving vertical vibration of the free vibration end. Simultaneously, when the first left-side driving region 301 and the second left-side driving region 303 extend synchronously, the first right-side driving region 302 and the second right-side driving region 304 contract synchronously, and the extension and contraction amounts are consistent, thus causing the free vibration end to move to the right in the horizontal direction; conversely, the free vibration end moves to the left in the horizontal direction, thereby achieving horizontal left-right vibration of the free vibration end. The synthesis of the vibrations in these two directions achieves two-dimensional scanning of the free vibration end. When the scanning actuator is used in grid scanning mode, the vertical vibration is a low-frequency vibration, and the horizontal vibration is a high-frequency vibration.
[0041] That is, the action of each of the four driving regions mentioned above consists of two components. One component works with the driving region with the same piezoelectric element (same piezoelectric element but on the opposite side), and the other component works with the driving region on the same side (same left or same right side but different piezoelectric element). The overall extension and retraction action is synthesized by these two components.
[0042] The scanning actuator can be installed either by fixing it to the rear end face or by supporting it from the rear side; there are no restrictions on which method is used.
[0043] In a preferred embodiment, the upper piezoelectric sheet 103 and the lower piezoelectric sheet 102 have the same polarization direction. The first left driving region 301 and the first right driving region 302 share the upper electrode layer 104, the second left driving region 303 and the second right driving region 304 share the lower electrode layer 101, the first left driving region 301 and the second left driving region 303 share the left electrode layer, and the first right driving region 302 and the second right driving region 304 share the right electrode layer. Further, the driving method is as follows: Figure 4 As shown, the upper electrode layer 104 is connected to the first power signal, the lower electrode layer 101 is connected to the second power signal, the left electrode layer is connected to the first drive signal, and the right electrode layer is connected to the second drive signal. Both the first and second power signals can be positive or negative, and their polarities are opposite, specifically determined by the polarization directions of the upper piezoelectric element 103 and the lower piezoelectric element 102. Of course, the above is only a preferred embodiment; the polarization direction and corresponding drive signal can be selected according to specific operating conditions.
[0044] The driving method of the actuator in the above embodiment is further explained below in conjunction with the driving signals: When the first driving signal and the second driving signal are the same, the vertical deformation directions of the dual piezoelectric structure are opposite, resulting in vertical bending and achieving vertical vibration; when the first driving signal and the second driving signal are out of phase, the horizontal deformation directions of the dual piezoelectric structure are opposite, resulting in horizontal bending and achieving horizontal vibration. Therefore, both the first driving signal and the second driving signal can adopt a frequency mixing driving method, so that the dual crystals vibrate at different frequencies in the vertical and horizontal directions respectively.
[0045] As an optional specific embodiment, the first driving signal is:
[0046] SIgL=Fy(2πωyt+ɸyL)+Axcsin(2πωxt+ɸxcL)+Axsin(2πωxt+ɸxL),
[0047] The second driving signal is:
[0048] SIgR= Fy(2πωyt+ɸyR)+Axcsin(2πωxt+ɸxcR)+Axsin(2πωxt+ɸxR).
[0049] Axsin(2πωxt+ɸxL) / Axsin(2πωxt+ɸxR) are high-frequency drive signals in the left-right direction (X-direction), which can be sine waves or other waveforms depending on the application requirements. Ideally, the difference between ɸxL and ɸxR is 180°. In practical applications, due to processing precision, there are slight differences in the response characteristics of the left and right sides of the dual-wafer system. Appropriately adjusting the difference between ɸxL and ɸxR ensures that the deformations on the left and right sides are strictly out of phase, achieving maximum deformation and minimum vertical component. Ax represents the voltage amplitude of the control signals Axsin(2πωxt+ɸxL) and Axsin(2πωxt+ɸxR), ɸxL represents the initial phase of the control signal Axsin(2πωxt+ɸxL), and ɸxR represents the initial phase of the control signal Axsin(2πωxt+ɸxR).
[0050] Fy(2πωyt+ɸyL) / Fy(2πωyt+ɸyR) is a low-frequency drive signal in the vertical direction (Y direction), which can be a sine wave or other waveforms depending on the application requirements. Ideally, the signal components in SIgL / SIgR signals are completely identical, i.e., ɸyL=ɸyR. In practical applications, due to processing precision, there are slight differences in the response characteristics of the upper and lower sides of the dual wafers. Appropriately adjusting the difference between ɸyL and ɸyR makes the deformation on the upper and lower sides strictly out of phase, in order to achieve the maximum deformation and the minimum vertical component. Fy is the voltage amplitude of the control signals Fy(2πωyt+ɸyL) and Fy(2πωyt+ɸyR), ɸyL is the initial phase of the control signal Fy(2πωyt+ɸyL), and ɸyR is the initial phase of the control signal Fy(2πωyt+ɸyR).
[0051] Axcsin(2πωxt+ɸxcL) / Axcsin(2πωxt+ɸxcR) is the X-direction correction signal, used to correct the Y-direction component of the fast-axis trajectory to zero, making its trajectory a closed trajectory. Ideally, in the SIgL / SIgR signals, these signal components are completely identical, i.e., ɸxcL=ɸxcR. Axc is the voltage amplitude of the control signals Axcsin(2πωxt+ɸxcL) and Axcsin(2πωxt+ɸxcR), ɸxcL is the initial phase of the control signal Axcsin(2πωxt+ɸxcL), and ɸxcR is the initial phase of the control signal Axcsin(2πωxt+ɸxcR).
[0052] A second aspect of this utility model provides an optical fiber scanner, including a scanning actuator and an optical fiber as described above. The optical fiber is fixedly inserted into the optical fiber mounting hole 107, and the light-emitting end of the optical fiber passes through the free vibration end of the scanning actuator to form an optical fiber cantilever 200. The portion of the optical fiber located on the rear side of the optical fiber cantilever 200 is fixedly connected to the scanning actuator.
[0053] It should be noted that the above embodiments are illustrative of the present invention and not limiting of it, and that those skilled in the art can devise alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses should not be construed as limiting the claims. The words “comprising” or “including” do not exclude the presence of elements or steps not listed in the claims. The words “a” or “an” preceding an element do not exclude the presence of a plurality of such elements. The use of the words first, second, and third, etc., does not indicate any order and these words can be interpreted as names.
[0054] All features disclosed in this specification, except for mutually exclusive features, can be combined in any way.
[0055] Any feature disclosed in this specification (including any appended claims, abstract, and drawings) may be replaced by other equivalent or similar features for a similar purpose, unless specifically stated otherwise. That is, unless specifically stated otherwise, each feature is merely one example of a series of equivalent or similar features.
[0056] This invention is not limited to the specific embodiments described above. This invention extends to any new feature or combination disclosed in this specification, as well as any new method or process step or combination disclosed herein.
Claims
1. A scanning actuator, characterized by, The actuator body is integrally formed by sintering. The actuator body includes a lower electrode layer, a lower piezoelectric sheet, a middle electrode layer, an upper piezoelectric sheet, and an upper electrode layer arranged sequentially from bottom to top. The extension direction of the piezoelectric sheet is taken as the horizontal plane, and the front end of the actuator body is taken as the free vibration end. An optical fiber mounting hole is machined at the center of the front end face of the actuator body, which runs through the actuator body in the front-back direction. The optical fiber mounting hole divides the middle electrode layer into a left electrode layer and a right electrode layer that are independent of each other. The upper and lower piezoelectric sheets are both polarized in the vertical direction. Under the drive of the drive signal, the upper and lower piezoelectric sheets synchronously extend and retract in opposite directions to drive the free vibration end to vibrate in the vertical direction. At the same time, the left side and the right side of the upper and lower piezoelectric sheets synchronously extend and retract in opposite directions to drive the free vibration end to vibrate left and right in the horizontal direction.
2. A scanning actuator as claimed in claim 1, wherein The upper and lower piezoelectric sheets are completely identical in shape and size and completely overlap. The lower electrode layer, the middle electrode layer before the unprocessed fiber mounting hole, and the upper electrode layer all completely cover the corresponding surfaces of the piezoelectric sheets.
3. A scanning actuator as claimed in claim 1 or 2, wherein Since the left and right electrode layers are independent of each other, the left and right sides of the upper piezoelectric sheet body form a first left driving region and a first right driving region symmetrically arranged, and the left and right sides of the lower piezoelectric sheet body form a second left driving region and a second right driving region symmetrically arranged. The first left driving region and the second left driving region are vertically symmetrical, and the first right driving region and the second right driving region are vertically symmetrical.
4. A scanning actuator as claimed in claim 3, wherein the piezoelectric element is a piezoelectric bimorph. The first left-side drive area and the first right-side drive area perform a first synchronous equal-length extension and retraction action, and the second left-side drive area and the second right-side drive area perform a second synchronous equal-length extension and retraction action, with the first synchronous extension and retraction action and the second synchronous extension and retraction action being synchronous, equal in length, and opposite in direction; at the same time, the first left-side drive area and the second left-side drive area perform a third synchronous equal-length extension and retraction action, and the first right-side drive area and the second right-side drive area perform a fourth synchronous equal-length extension and retraction action, with the third synchronous extension and retraction action and the fourth synchronous extension and retraction action being synchronous, equal in length, and opposite in direction.
5. A scanning actuator as claimed in claim 4, wherein the piezoelectric element is a piezoelectric bimorph. When the first left driving region and the first right driving region extend synchronously, the second left driving region and the second right driving region contract synchronously, and the extension and contraction amounts are consistent, so that the free vibration end moves downward in the vertical direction; conversely, the free vibration end moves upward in the vertical direction; thereby realizing the vibration of the free vibration end in the vertical direction. Simultaneously, when the first left-side driving region and the second left-side driving region extend synchronously, the first right-side driving region and the second right-side driving region contract synchronously, and the extension and contraction amounts are consistent, thereby causing the free vibration end to move to the right in the horizontal direction; conversely, the free vibration end moves to the left in the horizontal direction; thus realizing the free vibration end to vibrate left and right in the horizontal direction.
6. A scanning actuator as claimed in claim 4 or 5, wherein the piezoelectric element is a piezoelectric bimorph. The upper and lower piezoelectric sheets have the same polarization direction. The upper electrode layer is connected to the first power signal, the lower electrode layer is connected to the second power signal, the left electrode layer is connected to the first drive signal, and the right electrode layer is connected to the second drive signal. The first and second power signals can be either positive or negative power signals, and the polarities of the first and second power signals are opposite.
7. A scanning actuator as claimed in claim 5, wherein the piezoelectric element is a piezoelectric bimorph. Both the first and second driving signals can be driven by a frequency mixing method, so that the two crystals vibrate at different frequencies in the vertical and horizontal directions, respectively.
8. A scanning actuator as claimed in claim 7, wherein the piezoelectric element is a piezoelectric bimorph. The first driving signal is: SIgL=Fy(2πωyt+ɸyL)+Axcsin(2πωxt+ɸxcL)+Axsin(2πωxt+ɸxL), The second driving signal is: SIgR= Fy(2πωyt+ɸyR)+Axcsin(2πωxt+ɸxcR)+Axsin(2πωxt+ɸxR); Axsin(2πωxt+ɸxL) and Axsin(2πωxt+ɸxR) are high-frequency driving signals in the left and right directions. Ax is the voltage amplitude of the control signals Axsin(2πωxt+ɸxL) and Axsin(2πωxt+ɸxR), ɸxL is the initial phase of the control signal Axsin(2πωxt+ɸxL), and ɸxR is the initial phase of the control signal Axsin(2πωxt+ɸxR). Ideally, the difference between ɸxL and ɸxR is 180°. In practical applications, due to the processing precision, there are slight differences in the response characteristics of the left and right sides of the dual wafers. Appropriately adjusting the difference between ɸxL and ɸxR makes the deformation on the left and right sides strictly out of phase, so as to achieve the maximum deformation and the minimum vertical component. Fy(2πωyt+ɸyL) and Fy(2πωyt+ɸyR) are low-frequency driving signals in the vertical direction. Fy is the voltage amplitude of the control signals Fy(2πωyt+ɸyL) and Fy(2πωyt+ɸyR), ɸyL is the initial phase of the control signal Fy(2πωyt+ɸyL), and ɸyR is the initial phase of the control signal Fy(2πωyt+ɸyR). Ideally, the signal components in SigL and SIgR are exactly the same, i.e., ɸyL=ɸyR. In practical applications, due to the processing precision, there are slight differences in the response characteristics of the upper and lower sides of the dual wafers. By appropriately adjusting the difference between ɸyL and ɸyR, the deformation on the upper and lower sides is strictly out of phase, so as to achieve the maximum deformation and the minimum vertical component. Axcsin(2πωxt+ɸxcL) and Axcsin(2πωxt+ɸxcR) are left and right direction correction signals used to correct the vertical component of the fast axis trajectory to zero, making its trajectory a closed trajectory. Axc is the voltage amplitude of the control signals Axcsin(2πωxt+ɸxcL) and Axcsin(2πωxt+ɸxcR), ɸxcL is the initial phase of the control signal Axcsin(2πωxt+ɸxcL), and ɸxcR is the initial phase of the control signal Axcsin(2πωxt+ɸxcR). Ideally, in the SIgL / SIgR signals, the signal components are completely identical, i.e., ɸxcL=ɸxcR.
9. A fiber scanner, comprising: Includes a scanning actuator and an optical fiber as described in any one of claims 1-8, wherein the optical fiber is fixedly inserted into the optical fiber mounting hole, and the light-emitting end of the optical fiber passes through the free vibration end of the scanning actuator to form an optical fiber cantilever, and the portion of the optical fiber located on the rear side of the optical fiber cantilever is fixedly connected to the scanning actuator.