Double-piezoelectric-patch scanning actuator and optical fiber scanner

Abstract

The double-piezoelectric-patch scanning actuator comprises an upper piezoelectric patch and a lower piezoelectric patch which are completely consistent in shape and size, and the left side and the right side of a body of the upper piezoelectric patch are symmetrically provided with a first left side driving area and a first right side driving area. A second left side driving area and a second right side driving area are symmetrically arranged on the left side and the right side of the body of the lower piezoelectric plate, the first left side driving area and the first right side driving area perform first synchronous equal-length telescopic action, and the second left side driving area and the second right side driving area perform second synchronous equal-length telescopic action; the first left-side driving area and the second left-side driving area perform third synchronous equal-length telescopic action, and the first right-side driving area and the second right-side driving area perform fourth synchronous equal-length telescopic action. Two piezoelectric ceramic pieces of the piezoelectric bimorph simultaneously have a synchronous equal-length telescopic motion component and a synchronous reverse telescopic motion component, and two-dimensional scanning is achieved through the bimorph.

Description

Technical Field

[0001] The present invention relates to the technical field of optical fiber scanning display, and in particular to a dual piezoelectric scanning actuator and an optical fiber scanner. Background Art

[0002] Fiber optic scanner is a display technology that uses a scanning actuator to control the swing of an optical fiber to emit a pattern. The pattern illuminated by this technology has sharp and saturated colors, high contrast, high brightness, and a very small structure volume.

[0003] The actuator of the grid-type optical fiber scanner mainly includes a second actuator as a fast axis and a first actuator as a slow axis. The second actuator and the first actuator have a fixed end and a free end respectively. The fixed end of the second actuator is fixedly connected to the free end of the first actuator. In order to obtain a stable scanning range and accurately control the scanning trajectory, the scanning trajectory of the end of the actuator needs to be precisely consistent with the scanning trajectory of the first actuator and the scanning trajectory of the second actuator. Any machining error of the actuator will make the vibration of the actuator difficult to control or produce a chaotic vibration component.

[0004] Traditional scanner actuators are generally tubular or sheet-shaped. In order to make the actuator part in the slow axis direction meet the slow axis scanning frequency and the actuator part in the fast axis direction meet the fast axis scanning frequency, the shape and size of the actuator must be designed accordingly, which causes the actuator to become irregularly shaped.

[0005] For example, a scanning actuator disclosed in Chinese patent CN111830702A generally adopts a tubular piezoelectric actuator, but due to the above factors, it is designed to be a special-shaped structure, which is quite disadvantageous for mass production of actuators, difficult to process, and the processing consistency cannot be guaranteed. Another example is a scanning actuator disclosed in Chinese patent CN209784655U, which generally adopts a sheet-shaped piezoelectric actuator. For the same performance consideration, the actuator is also set to a special-shaped structure, and the above-mentioned technical problems of difficulty in precise processing and poor processing consistency also exist.

[0006] Therefore, how to make the actuator easy to process and mass produce with good consistency in mass production under the premise that each actuating part meets the performance parameters is a technical problem that needs to be solved. Summary of the invention

[0007] The embodiments of the present invention provide a dual piezoelectric scanning actuator and an optical fiber scanner, which are used to at least solve the technical problems that actuators are difficult to mass produce and mass production consistency is poor.

[0008] To achieve the above-mentioned invention object, a bimorph scanning actuator is provided in the first aspect of the present invention, which includes an upper piezoelectric sheet and a lower piezoelectric sheet with exactly the same shape and size. Taking the extending direction of the piezoelectric sheet as the horizontal plane direction, the upper piezoelectric sheet and the lower piezoelectric sheet are completely overlapped and attached up and down. The front end of the whole formed by the upper piezoelectric sheet and the lower piezoelectric sheet is the free vibration end. A first left driving area and a first right driving area are symmetrically arranged on the left and right sides of the body of the upper piezoelectric sheet, and a second left driving area and a second right driving area are symmetrically arranged on the left and right sides of the body of the lower piezoelectric sheet. The first left driving area and the second left driving area are symmetric up and down, and the first right driving area and the second right driving area are symmetric up and down. Electrode layers are correspondingly arranged on the upper and lower surfaces of each driving area. Under the drive of a driving signal:

[0009] The first left driving area and the first right driving area perform a first synchronous and equal-length telescopic action, the second left driving area and the second right driving area perform a second synchronous and equal-length telescopic action, and the first synchronous telescopic action and the second synchronous telescopic action are synchronous, equal-length and opposite; meanwhile, the first left driving area and the second left driving area perform a third synchronous and equal-length telescopic action, the first right driving area and the second right driving area perform a fourth synchronous and equal-length telescopic action, and the third synchronous telescopic action and the fourth synchronous telescopic action are synchronous, equal-length and opposite.

[0010] When the bimorph scanning actuator is installed, it can be installed in a way of fixing the rear end face, or it can be installed in a way of supporting the rear side. There is no limitation on this.

[0011] As a preferred embodiment, the polarization directions of the upper piezoelectric sheet and the lower piezoelectric sheet are the same. Further preferably, an upper electrode layer is arranged on the upper surface of the upper piezoelectric sheet, and a lower electrode layer is arranged on the lower surface of the lower piezoelectric sheet. Thus, the first left driving area and the first right driving area share the upper electrode layer, the second left driving area and the second right driving area share the lower electrode layer, a left electrode layer is arranged on the left side between the upper piezoelectric sheet and the lower piezoelectric sheet, and a right electrode layer is arranged on the right side between the upper piezoelectric sheet and the lower piezoelectric sheet. Thus, the first left driving area and the second left driving area share the left electrode layer, and the first right driving area and the second right driving area share the right electrode layer.

[0012] Optionally, the driving method of the scanning actuator with the above structure is as follows: 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 driving signal, and the right electrode layer is connected to a second driving signal. Both the first power signal and the second power signal can be a positive power signal or a negative power signal, and the polarities of the first power signal and the second power signal are opposite, which is specifically set according to the polarization directions of the upper piezoelectric sheet and the lower piezoelectric sheet.

[0013] The operation mode of the bimorph structure composed of the upper piezoelectric sheet and the lower piezoelectric sheet is further described in combination with the driving signals: when the first driving signal and the second driving signal are the same, the deformation directions of the upper and lower parts of the bimorph structure are opposite, generating bending in the vertical direction to achieve vibration in the vertical direction; when the first driving signal and the second driving signal are out of phase, the deformation directions of the left and right parts of the bimorph structure are opposite, generating bending in the horizontal direction to achieve vibration in the horizontal direction. Therefore, both the first driving signal and the second driving signal can adopt the mixed-frequency driving method, enabling the bimorph to vibrate simultaneously in the vertical and horizontal directions at different frequencies.

[0014] As an optional specific embodiment, the first driving signal is:

[0015] SIgL = Fy(2πωyt + φyL) + Axcsin(2πωxt + φxcL) + Axsin(2πωxt + φxL),

[0016] The second driving signal is:

[0017] SIgR = Fy(2πωyt + φyR) + Axcsin(2πωxt + φxcR) + Axsin(2πωxt + φxR).

[0018] Axsin(2πωxt + φxL) / Axsin(2πωxt + φxR) is the high-frequency driving signal in the left-right direction (X direction), which can be a sine wave or other waveforms according to application requirements. Among them, the difference between φxL and φxR is 180° in the ideal case. In actual applications, due to processing accuracy, there are slight differences in the response characteristics of the left and right sides of the bimorph. Appropriately adjust the difference between φxL and φxR so that the deformations on the left and right sides are strictly out of phase to achieve the maximum deformation and the minimum vertical direction component. Ax is the voltage amplitude of the control signals Axsin(2πωxt + φxL) and Axsin(2πωxt + φxR), φxL is the initial phase of the control signal Axsin(2πωxt + φxL), and φxR is the initial phase of the control signal Axsin(2πωxt + φxR);

[0019] Fy(2πωyt + φyL) / Fy(2πωyt + φyR) is the low-frequency drive signal in the vertical direction (Y direction), which can be a sine wave or other waveforms according to application requirements. Ideally, in the SIgL / SIgR signal, the components of this signal are exactly the same, that is, φyR = φyR. In practical applications, due to processing accuracy, there are slight differences in the response characteristics of the upper and lower sides of the bimorph. Appropriately adjusting the difference between φyL and φyR makes the deformations of the upper and lower sides strictly out of phase to achieve the maximum deformation and the minimum vertical direction component. Fy is the voltage amplitude of the control signals Fy(2πωyt + φyL) and Fy(2πωyt + φyR), φyL is the initial phase of the control signal Fy(2πωyt + φyL), and φyR is the initial phase of the control signal Fy(2πωyt + φyR).

[0020] Axcsin(2πωxt + φxcL) / Axcsin(2πωxt + φxcR) is the correction signal in the X direction, which is used to correct the Y direction component of the fast axis trajectory to zero so that its trajectory is a closed trajectory. Ideally, in the SIgL / SIgR signal, the components of this signal are exactly the same, that is, φxcL = φxcR. Axc is the voltage amplitude of the control signals Axcsin(2πωxt + φxcL) and Axcsin(2πωxt + φxcR), φxcL is the initial phase of the control signal Axcsin(2πωxt + φxcL), and φxcR is the initial phase of the control signal Axcsin(2πωxt + φxcR).

[0021] In the second aspect of the embodiments of the present invention, an optical fiber scanning actuator is provided, which includes the bimorph scanning actuator as described above and an optical fiber. The light-emitting end of the optical fiber is fixed to the front end of the bimorph scanning actuator in a cantilever-supported manner.

[0022] Specifically, the part of the light-emitting end of the optical fiber that extends beyond the front end of the bimorph scanning actuator forms an optical fiber cantilever, and the part of the optical fiber located behind the optical fiber cantilever is fixedly connected to the bimorph scanning actuator.

[0023] One or more technical solutions in the embodiments of the present invention have at least the following technical effects or advantages:

[0024] In the present invention, the synchronous and equal-length expansion and contraction of the two piezoelectric ceramic sheets will drive the free end of the bimorph to vibrate in the horizontal direction; when the two piezoelectric ceramic sheets of the bimorph expand and contract synchronously and in the opposite direction, it will drive the free end of the bimorph to vibrate in the vertical direction. The present invention utilizes the fact that the two piezoelectric ceramic sheets of the bimorph simultaneously have the motion components of synchronous and equal-length expansion and contraction and synchronous and opposite-direction expansion and contraction, and drives the free end of the bimorph to vibrate in the horizontal direction and the vertical direction at the same time, and realizes two-dimensional scanning through the bimorph.

[0025] The present invention is composed of a piezoelectric bimorph and an adhesive component. The component is convenient for manufacturing and processing, and it is easy to ensure the consistency of product specifications, performance, and parameters during mass production. For fiber optic scanning imaging technology, the good consistency of the actuator is one of the key factors for the mass production of fiber optic scanners. At the same time, the sheet-like structure enables a large difference in the characteristic frequency values of the actuator in the horizontal and vertical directions, which can greatly reduce the vibration coupling of the actuator in the two vibration directions.

[0026] In the present invention, by increasing or decreasing the difference between φa1 and φb, the scanning trajectory of the free end of the piezoelectric bimorph can be corrected to a straight line along the X direction, and by increasing or decreasing the difference between φa2 and φb2, the scanning trajectory of the free end of the piezoelectric bimorph can be corrected to a straight line along the Y direction. There is no need to set an additional correction structure, which also helps to reduce the processing difficulty and is suitable for mass production. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a schematic structural diagram of the present invention;

[0028] Figure 2 is a schematic diagram of the driving area distribution structure of the present invention;

[0029] Figure 3 is a top view schematic diagram of the distribution of two driving areas of the upper piezoelectric sheet;

[0030] Figure 4 is a schematic diagram of the access of driving signals for an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0031] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0032] A first aspect of the present invention provides a bimorph scanning actuator, which includes an upper piezoelectric sheet 100 and a lower piezoelectric sheet 200 with exactly the same shape and size. With the extension direction of the piezoelectric sheet as the horizontal plane direction, the upper piezoelectric sheet 100 and the lower piezoelectric sheet 200 are completely overlapped and attached up and down. The front end of the whole formed by the upper piezoelectric sheet 100 and the lower piezoelectric sheet 200 is a free vibration end 300. On the left and right sides of the body of the upper piezoelectric sheet 100, a first left driving area 101 and a first right driving area 102 are symmetrically arranged. On the left and right sides of the body of the lower piezoelectric sheet 200, a second left driving area 201 and a second right driving area 202 are symmetrically arranged. The first left driving area and the second left driving area 201 are symmetric up and down, and the first right driving area 102 and the second right driving area 202 are symmetric up and down. Electrode layers are correspondingly arranged on the upper and lower surfaces of the first left driving area 101, the first right driving area 102, the second left driving area 201, and the second right driving area 202. Under the drive of a drive signal:

[0033] The first left driving area 101 and the first right driving area 102 perform a first synchronous and equal-length stretching action, and the second left driving area 201 and the second right driving area 202 perform a second synchronous and equal-length stretching action, and the first synchronous stretching action and the second synchronous stretching action are synchronous, equal-length, and opposite; at the same time, the first left driving area 101 and the second left driving area 201 perform a third synchronous and equal-length stretching action, and the first right driving area 102 and the second right driving area 202 perform a fourth synchronous and equal-length stretching action, and the third synchronous stretching action and the fourth synchronous stretching action are synchronous, equal-length, and opposite.

[0034] Specifically, when the first left driving area 101 and the first right driving area 102 synchronously elongate, the second left driving area 201 and the second right driving area 202 synchronously contract, and the above-mentioned elongation and contraction amounts are the same, so that the free vibration end 300 moves downward in the vertical direction; conversely, the free vibration end 300 moves upward in the vertical direction; thus, the free vibration end 300 vibrates in the vertical direction. At the same time, when the first left driving area 101 and the second left driving area 201 synchronously elongate, the first right driving area 102 and the second right driving area 202 synchronously contract, and the above-mentioned elongation and contraction amounts are the same, so that the free vibration end 300 moves to the right in the horizontal direction; conversely, the free vibration end 300 moves to the left in the horizontal direction; thus, the free vibration end 300 vibrates left and right in the horizontal direction. The synthesis of the vibrations in the above two directions realizes the two-dimensional scanning of the free vibration end. When the bimorph scanning actuator is used in a raster scanning mode, the vibration in the vertical direction is a low-frequency vibration, and the vibration in the horizontal direction is a high-frequency vibration.

[0035] That is, for the above four driving regions, the movement of each driving region includes two components. One component cooperates with the driving region of the same piezoelectric sheet (the same piezoelectric sheet and on the opposite side), and one component cooperates with the driving region on the same side (the same left side or the same right side and different piezoelectric sheets). Its overall telescopic movement is synthesized by these two components.

[0036] The present invention is composed of two piezoelectric sheets with exactly the same structural dimensions. The components are convenient to manufacture and process, and it is easy to ensure the consistency of product specifications, performance, and parameters in mass production. For the fiber optic scanning imaging technology, the good consistency of the actuator is one of the key factors for the mass production of the fiber optic scanner. At the same time, the sheet-like structure makes the difference in the characteristic frequency values of the actuator in the horizontal and vertical directions very large. When the bimorph scanning actuator is used in the raster scanning mode, the vibration coupling of the actuator in the two vibration directions can be greatly reduced.

[0037] When installing the bimorph scanning actuator, it can be installed in a way of fixing the rear end face, or it can be installed in a way of supporting the rear side. There is no limitation on this.

[0038] As a preferred embodiment, the polarization directions of the upper piezoelectric sheet 100 and the lower piezoelectric sheet 200 are the same. Further preferably, an upper electrode layer 401 is provided on the upper surface of the upper piezoelectric sheet 100, and a lower electrode layer 402 is provided on the lower surface of the lower piezoelectric sheet 200. Thus, the first left driving region 101 and the first right driving region 102 share the upper electrode layer 401, the second left driving region 201 and the second right driving region 202 share the lower electrode layer 402. A left electrode layer 403 is provided on the left side between the upper piezoelectric sheet 100 and the lower piezoelectric sheet 200, and a right electrode layer 404 is provided on the right side between the upper piezoelectric sheet 100 and the lower piezoelectric sheet 200. Thus, the first left driving region 101 and the second left driving region 201 share the left electrode layer 403, and the first right driving region 102 and the second right driving region 202 share the right electrode layer 404.

[0039] The above structure makes the structural configurations of the upper piezoelectric sheet 100 and the lower piezoelectric sheet 200 further completely consistent, and only one electrode layer (including two parts: the left electrode layer and the right electrode layer) is provided between the two piezoelectric sheets. This electrode layer is an ultra-thin metal conductive layer (with a thickness less than 10 μm), which simplifies the structure, enables the entire scanning actuator to be sintered integrally without additional materials such as adhesives, simplifies the production process, and is convenient for mass production.

[0040] Optionally, the driving method of the scanning actuator with the above structure is as follows: the upper electrode layer 401 is connected to a first power signal, the lower electrode layer 402 is connected to a second power signal, the left electrode layer is connected to a first driving signal, and the right electrode layer is connected to a second driving signal. Both the first power signal and the second power signal can be positive power signals or negative power signals, and the polarities of the first power signal and the second power signal are opposite, which is specifically set according to the polarization directions of the upper piezoelectric sheet 100 and the lower piezoelectric sheet 200.

[0041] The operation mode of the bimorph structure composed of the upper piezoelectric sheet 100 and the lower piezoelectric sheet 200 is further described in combination with the driving signals: when the first driving signal and the second driving signal are the same, the up-and-down deformation directions of the bimorph structure are opposite, generating bending in the vertical direction to achieve vertical vibration; when the first driving signal and the second driving signal are out of phase, the left-and-right deformation directions of the bimorph structure are opposite, generating bending in the horizontal direction to achieve left-and-right vibration. Therefore, both the first driving signal and the second driving signal can adopt a mixed-frequency driving method, enabling the bimorph to vibrate simultaneously in the vertical and horizontal directions at different frequencies.

[0042] As an optional specific embodiment, the first driving signal is:

[0043] SIgL = Fy(2πωyt + φyL) + Axcsin(2πωxt + φxcL) + Axsin(2πωxt + φxL),

[0044] The second driving signal is:

[0045] SIgR = Fy(2πωyt + φyR) + Axcsin(2πωxt + φxcR) + Axsin(2πωxt + φxR).

[0046] Axsin(2πωxt + φxL) / Axsin(2πωxt + φxR) is a high-frequency driving signal in the left-and-right direction (X direction), which can be a sine wave or other waveforms according to application requirements. Among them, the difference between φxL and φxR is 180° in the ideal case. In actual applications, due to processing accuracy, there are slight differences in the response characteristics of the two sides of the bimorph. Appropriately adjusting the difference between φxL and φxR makes the deformations of the left and right sides strictly out of phase to achieve the maximum deformation amount and the minimum vertical direction component. Ax is the voltage amplitude of the control signals Axsin(2πωxt + φxL) and Axsin(2πωxt + φxR), φxL is the initial phase of the control signal Axsin(2πωxt + φxL), and φxR is the initial phase of the control signal Axsin(2πωxt + φxR);

[0047] Fy(2πωyt + φyL) / Fy(2πωyt + φyR) is the low-frequency driving signal in the vertical direction (Y direction), which can be a sine wave or other waveforms according to application requirements. Ideally, in the SIgL / SIgR signal, the components of this signal are exactly the same, i.e., φyR = φyR. In practical applications, due to processing accuracy, there are slight differences in the response characteristics on the upper and lower sides of the bimorph. Appropriately adjusting the difference between φyL and φyR makes the deformations on the upper and lower sides strictly out of phase to achieve the maximum deformation and the minimum vertical direction component. Fy is the voltage amplitude of the control signals Fy(2πωyt + φyL) and Fy(2πωyt + φyR), φyL is the initial phase of the control signal Fy(2πωyt + φyL), and φyR is the initial phase of the control signal Fy(2πωyt + φyR).

[0048] Axcsin(2πωxt + φxcL) / Axcsin(2πωxt + φxcR) is the correction signal in the X direction, which is used to correct the Y-direction component of the fast-axis trajectory to zero so that its trajectory is a closed trajectory. Ideally, in the SIgL / SIgR signal, the components of this signal are exactly the same, i.e., φxcL = φxcR. Axc is the voltage amplitude of the control signals Axcsin(2πωxt + φxcL) and Axcsin(2πωxt + φxcR), φxcL is the initial phase of the control signal Axcsin(2πωxt + φxcL), and φxcR is the initial phase of the control signal Axcsin(2πωxt + φxcR).

[0049] In the second aspect of the embodiments of the present invention, an optical fiber scanning actuator is provided, which includes the bimorph scanning actuator as described above and an optical fiber 500. The light-emitting end of the optical fiber 500 is fixed to the front end of the bimorph scanning actuator in a cantilever-supported manner.

[0050] Specifically, the part of the light-emitting end of the optical fiber 500 that extends beyond the front end of the bimorph scanning actuator forms an optical fiber cantilever 501, and the part of the optical fiber 500 located behind the optical fiber cantilever 501 is fixedly connected to the bimorph scanning actuator.

[0051] It should be noted that the above embodiments illustrate the present invention rather than limit the present invention, and those skilled in the art can design alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claims. The word "comprising" or "including" does not exclude the presence of elements or steps not listed in the claims. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The use of the words first, second, and third, etc. does not denote any order and these words can be interpreted as names.

[0052] All features disclosed in this specification, except mutually exclusive features, may be combined in any manner.

[0053] Any feature disclosed in this specification (including any additional claims, abstract and drawings), unless specifically recited, may be replaced by other equivalent or alternative features with similar purposes. That is, unless specifically recited, each feature is only an example of a series of equivalent or similar features.

[0054] The present invention is not limited to the foregoing specific embodiments. The present invention extends to any new feature or any new combination disclosed in this specification, as well as to any new method or process step or any new combination disclosed.

Claims

1. A bimorph scanning actuator, characterized in that, it includes an upper piezoelectric sheet and a lower piezoelectric sheet with exactly the same shape and size. Taking the extension direction of the piezoelectric sheet as the horizontal plane direction, the upper piezoelectric sheet and the lower piezoelectric sheet are completely overlapped and attached up and down. The front end of the whole formed by the upper piezoelectric sheet and the lower piezoelectric sheet is the free vibration end. On the left and right sides of the body of the upper piezoelectric sheet, a first left driving area and a first right driving area are symmetrically arranged. On the left and right sides of the body of the lower piezoelectric sheet, a second left driving area and a second right driving area are symmetrically arranged. The first left driving area and the second left driving area are symmetric up and down, and the first right driving area and the second right driving area are symmetric up and down. Electrode layers are correspondingly arranged on the upper and lower surfaces of each driving area. Driven by a driving signal: The first left driving area and the first right driving area perform a first synchronous and equal-length telescopic action, the second left driving area and the second right driving area perform a second synchronous and equal-length telescopic action, and the first synchronous telescopic action and the second synchronous telescopic action are synchronous, equal-length and opposite; at the same time, the first left driving area and the second left driving area perform a third synchronous and equal-length telescopic action, the first right driving area and the second right driving area perform a fourth synchronous and equal-length telescopic action, and the third synchronous telescopic action and the fourth synchronous telescopic action are synchronous, equal-length and opposite.

2. A bimorph scanning actuator according to claim 1, characterized in that, the polarization directions of the upper piezoelectric sheet and the lower piezoelectric sheet are the same.

3. A bimorph scanning actuator according to claim 2, characterized in that, an upper electrode layer is arranged on the upper surface of the upper piezoelectric sheet, and a lower electrode layer is arranged on the lower surface of the lower piezoelectric sheet. Thus, the first left driving area and the first right driving area share the upper electrode layer, the second left driving area and the second right driving area share the lower electrode layer. A left electrode layer is arranged on the left side between the upper piezoelectric sheet and the lower piezoelectric sheet, and a right electrode layer is arranged on the right side between the upper piezoelectric sheet and the lower piezoelectric sheet. Thus, the first left driving area and the second left driving area share the left electrode layer, and the first right driving area and the second right driving area share the right electrode layer.

4. A bimorph scanning actuator according to claim 3, characterized in that, 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 driving signal, and the right electrode layer is connected to a second driving signal. Both the first power signal and the second power signal can be a positive power signal or a negative power signal, and the first power signal and the second power signal have opposite polarities.

5. A bimorph scanning actuator according to claim 4, characterized in that, when the first driving signal and the second driving signal are the same, the up and down deformation directions of the bimorph structure are opposite, generating bending in the vertical direction and realizing vibration in the vertical direction; when the first driving signal and the second driving signal are out of phase, the left and right deformation directions of the bimorph structure are opposite, generating bending in the horizontal direction and realizing vibration in the horizontal direction; both the first driving signal and the second driving signal adopt a mixed-frequency driving method, so that the bimorph vibrates in the vertical direction and the horizontal direction at different frequencies simultaneously.

6. A bimorph scanning actuator as claimed in claim 5, wherein, the first driving signal is: SIgL = Fy(2πωyt + ΦyL) + Axcsin(2πωxt + ΦxcL) + Axsin(2πωxt + ΦxL), the second driving signal is: SIgR = Fy(2πωyt + ΦyR) + Axcsin(2πωxt + ΦxcR) + Axsin(2πωxt + ΦxR). Axsin(2πωxt + ΦxL) / Axsin(2πωxt + φxR) is the high-frequency driving signal in the left-right direction (X direction), which can be a sine wave or other waveforms according to application requirements. Among them, the difference between φxL and φxR is 180° in the ideal case. In actual applications, due to processing accuracy, there are slight differences in the response characteristics on the left and right sides of the bimorph. Appropriately adjust the difference between φxL and φxR so that the deformations on the left and right sides are strictly out of phase to achieve the maximum deformation and the minimum vertical direction component. Ax is the voltage amplitude of the control signals Axsin(2πωxt + ΦxL) and Axsin(2πωxt + φxR), φxL is the initial phase of the control signal Axsin(2πωxt + φxL), and φxR is the initial phase of the control signal Axsin(2πωxt + φxR); Fy(2πωyt + φyL) / Fy(2πωyt + ΦyR) is the low-frequency driving signal in the vertical direction (Y direction), which can be a sine wave or other waveforms according to application requirements. In the ideal case, in the SIgL / SIgR signal, this signal component is exactly the same, that is, ΦyR = ΦyR. In actual applications, due to processing accuracy, there are slight differences in the response characteristics on the upper and lower sides of the bimorph. Appropriately adjust the difference between ΦyL and ΦyR so that the deformations on the upper and lower sides are strictly out of phase to achieve the maximum deformation and the minimum vertical direction component. Fy is the voltage amplitude of the control signals Fy(2πωyt + ΦyL) and Fy(2πωyt + ΦyR), ΦyL is the initial phase of the control signal Fy(2πωyt + ΦyL), and ΦyR is the initial phase of the control signal Fy(2πωyt + ΦyR). Axcsin(2πωxt + ΦxcL) / Axcsin(2πωxt + ΦxcR) is the X-direction correction signal, which is used to correct the Y-direction component of the fast-axis trajectory to zero so that its trajectory is a closed trajectory. In the ideal case, in the SIgL / SIgR signal, this signal component is exactly the same, that is, ΦxcL = ΦxcR. Axc is the voltage amplitude of the control signals Axcsin(2πωxt + ΦxcL) and Axcsin(2πωxt + ΦxcR), φxcL is the initial phase of the control signal Axcsin(2πωxt + ΦxcL), and ΦxcR is the initial phase of the control signal Axcsin(2πωxt + ΦxcR).

7. An optical fiber scanning actuator, wherein, Comprising a bimorph scanning actuator and an optical fiber as described in any one of claims 1-6, the light-emitting end of the optical fiber is fixed to the front end of the bimorph scanning actuator in a cantilever-supported manner.

8. An optical fiber scanning actuator as claimed in claim 7, characterized in that the portion of the light-emitting end of the optical fiber that extends beyond the front end of the bimorph scanning actuator forms an optical fiber cantilever, and the portion of the optical fiber located behind the optical fiber cantilever is fixedly connected to the bimorph scanning actuator.

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