Scanning actuator and optical fiber scanner

Abstract

The present invention discloses a scanning actuator, including a first actuating part, wherein the first actuating part includes a piezoelectric ceramic substrate, with the front and rear ends of the piezoelectric ceramic substrate being a fixed end and a free end respectively, and the thickness direction of the piezoelectric ceramic substrate being a vertical direction. At least one of the left and right sides of the piezoelectric ceramic substrate is provided with a driving electrode pair, wherein the driving electrode pair includes an upper electrode layer provided on the upper surface of the piezoelectric ceramic substrate and a lower electrode layer provided on the lower surface of the piezoelectric ceramic substrate, and the portion of the piezoelectric ceramic substrate located between the driving electrode pairs is polarized in a vertical direction. Also disclosed is an optical fiber scanner using the scanning actuator. Since the expansion and contraction of a single-layer piezoelectric ceramic substrate on one side will only cause horizontal left-right vibration, the vertical vibration component is extremely small and does not require additional correction; the area of ​​the high-frequency driving electrode is reduced, and the driving power consumption is greatly reduced.

Description

Technical Field

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

[0002] Scanning display imaging, as an emerging display technology, can be used in a variety of display scenarios such as projection display and near-eye display.

[0003] Scanning display imaging can be achieved by the currently widely used digital micromirror device (DMD) as well as by a fiber optic scanner.

[0004] A typical fiber scanner structure is as follows: Figure 1 As shown in FIG. 1 , the optical fiber scanner mainly includes: a scanning actuator with a fast and slow axis structure, and an optical fiber for scanning light. The scanning actuator fixed on the base includes a slow axis, an isolation part, and a fast axis in the direction from back to front. Some optical fiber scanners may not have an isolation part. The slow axis is used to scan the light in the first direction (vertical direction, i.e., Figure 1 The fast axis is used to vibrate in the second direction (the Y-axis direction of the reference coordinate system in the middle) at a relatively slow frequency, and the fast axis is used to vibrate in the second direction (the horizontal direction, i.e. Figure 1 The optical fiber is vibrated at a relatively fast frequency (in the X-axis direction of the reference coordinate system in the middle), and the vibration of the slow axis is accumulated on the fast axis through the isolation portion, or in an embodiment without an isolation portion, the vibration of the slow axis is directly accumulated on the fast axis, thereby driving the optical fiber to perform two-dimensional scanning in the first direction and the second direction, realizing two-dimensional grid scanning and projecting an image.

[0005] When fiber scanners are used to achieve large-screen display or spliced ​​display, a large number of fiber scanners are usually required to work simultaneously, and the images emitted by each fiber scanner are spliced ​​on the display screen. At this time, a slight increase in the power consumption of a single fiber scanner will cause a significant increase in the overall power consumption, and thus the equipment cost, use cost, heat dissipation requirements, etc. will all increase significantly. Therefore, how to reduce the power consumption of a single scanner has become a technical problem that needs to be solved urgently.

[0006] At the same time, whether the scanner is easy to manufacture, how consistent the batch production is, and whether it is convenient for precise positioning and assembly also restrict the imaging quality. In order to obtain a stable scanning range and accurately control the scanning trajectory, the scanning trajectory of the fiber scanner needs to have precise consistency. Any loose installation structure and position error will make the vibration of the actuator difficult to control or produce messy vibration components. How to avoid uncontrolled or messy vibration components is also one of the important factors to improve scanning quality. Summary of the invention

[0007] The embodiments of the present invention provide a scanning actuator and an optical fiber scanner to at least solve the above-mentioned technical problems caused by the increase of power consumption.

[0008] In order to achieve the above-mentioned purpose of the invention, a first aspect of an embodiment of the present invention provides a scanning actuator, comprising a second actuating portion and a first actuating portion connected in sequence, wherein the first actuating portion comprises a piezoelectric ceramic substrate, with the front and rear ends of the piezoelectric ceramic substrate being a fixed end and a free end respectively, and the thickness direction of the piezoelectric ceramic substrate being a vertical direction, and at least one of the left side and the right side of the piezoelectric ceramic substrate being provided with a driving electrode pair, wherein the driving electrode pair comprises an upper electrode layer provided on the upper surface of the piezoelectric ceramic substrate and a lower electrode layer provided on the lower surface of the piezoelectric ceramic substrate, and a portion of the piezoelectric ceramic substrate located between the driving electrode pairs is polarized in a vertical direction, and the first actuating portion is driven by a lateral vibration mode in a width direction of a plate structure, and has a larger equivalent damping, a wider response bandwidth, and a smaller nonlinear effect, so that when the scanner is manufactured, the frequency matching of the optical fiber and the actuator is easier, and the adaptation range is wider, which is beneficial to improving the yield rate and manufacturing efficiency of finished products, and it is easier to improve the consistency of finished products.

[0009] The second actuating portion includes a substrate, and a piezoelectric driving layer arranged on the upper surface and / or the lower surface of the substrate, with the front and rear ends of the substrate being a fixed end and a free end respectively, and the thickness direction of the substrate being a vertical direction, the piezoelectric driving layer including a plurality of first electrodes and second electrodes sequentially arranged crosswise along the front-to-back direction, and a piezoelectric ceramic unit arranged between each adjacent first electrode and second electrode, each piezoelectric ceramic unit is polarized along the front-to-back direction, and the polarization directions of any two adjacent piezoelectric ceramic units are opposite, each first electrode is electrically connected to each other, and each second electrode is electrically connected to each other;

[0010] The fixed end of the piezoelectric ceramic substrate is fixedly connected to the free end of the substrate.

[0011] In a preferred embodiment, the first actuator is a fast-axis actuator, and the second actuator is a slow-axis actuator, and the vibration frequency of the fast-axis actuator is much greater than the vibration frequency of the slow-axis actuator. The present invention makes the extension direction of the piezoelectric ceramic substrate of the fast-axis actuator parallel to the vibration direction of the fast axis and parallel to the substrate of the slow axis. At the same time, there are no other layers on both sides of the piezoelectric ceramic substrate except the electrode layer. After dividing the left and right electrode areas, a single electrode pair is driven or two electrode pairs are reversely driven to achieve horizontal vibration. Since the fast axis has only a single-layer piezoelectric ceramic substrate, the expansion and contraction of a single side of the single-layer piezoelectric ceramic substrate or the synchronous reverse expansion and contraction of both sides will only cause left and right vibrations in the horizontal direction, and the vertical vibration component is extremely small. Only a simple drive is required to achieve horizontal swing of the fast axis, and basically no additional correction is required. At the same time, since the area of ​​the high-frequency driving electrode is reduced, the capacitance of the driving electrode is reduced, and the driving power consumption is greatly reduced. The sheet piezoelectric ceramic substrate is easier to achieve compactness, uniform material, good consistency, and high molding precision than the piezoelectric ceramic substrate with a special-shaped three-dimensional structure such as a tubular shape.

[0012] Each adjacent first electrode and second electrode of the slow axis actuator and the piezoelectric ceramic unit located between the first electrode and the second electrode constitute a driving unit, and the polarization direction of the piezoelectric ceramic unit is consistent with the overall expansion and contraction direction of the piezoelectric driving layer, so that the D33 directional variation of the piezoelectric ceramic unit can be used to drive the actuator to vibrate, which is nearly twice as large as the D32 or D31 directional variation of the piezoelectric ceramic unit, so that a larger swing can be achieved with a lower voltage, and the driving power consumption is also significantly reduced. Preferably, the first electrode and the second electrode completely cover the front end face or the rear end face of the piezoelectric ceramic unit, so that the entire piezoelectric ceramic unit is effectively driven.

[0013] At the same time, the present invention makes the second actuating part and the first actuating part both have a sheet (plate) structure with the same extension direction, so that a sheet actuator can achieve two-dimensional scanning, which can greatly reduce the negative impact of the fast and slow axis vibration coupling, and simplify the structure, reduce the complexity and difficulty of the processing technology, improve reliability, reduce costs, and facilitate mass production. The sheet structure has high molding and assembly accuracy, accurate packaging positioning, and can save the package lens adjustment mechanism, which is easy to mass produce.

[0014] Optionally, the substrate is a glass fiber board, a copper board or a steel board.

[0015] Therefore, optionally, in some embodiments of the present invention, a driving electrode pair is provided on the left side of the piezoelectric ceramic substrate, and no driving electrode pair is provided on the right side of the piezoelectric ceramic substrate, the driving electrode pair includes an upper electrode layer provided on the left side of the upper surface of the piezoelectric ceramic substrate and a lower electrode layer provided on the left side of the lower surface of the piezoelectric ceramic substrate, the upper electrode layer and the lower electrode layer are arranged opposite to each other, and after a driving voltage is applied through the upper electrode layer and the lower electrode layer, the left side of the piezoelectric ceramic substrate is extended or shortened in a horizontal direction under the driving voltage, when the left side of the piezoelectric ceramic substrate is extended in a horizontal direction under the driving voltage, the free end of the piezoelectric ceramic substrate is horizontally offset to the right relative to the fixed end; when the left side of the piezoelectric ceramic substrate is shortened in a horizontal direction under the driving voltage, the free end of the piezoelectric ceramic substrate is horizontally offset to the left relative to the fixed end.

[0016] In some other embodiments of the present invention, a driving electrode pair is provided on the right side of the piezoelectric ceramic substrate, and no driving electrode pair is provided on the left side of the piezoelectric ceramic substrate. The driving electrode pair includes an upper electrode layer provided on the right side of the upper surface of the piezoelectric ceramic substrate and a lower electrode layer provided on the right side of the upper surface of the piezoelectric ceramic substrate. The upper electrode layer and the lower electrode layer are arranged opposite to each other. After a driving voltage is applied through the upper electrode layer and the lower electrode layer, the right side of the piezoelectric ceramic substrate is extended or shortened in a horizontal direction under the driving voltage. When the right side of the piezoelectric ceramic substrate is extended in a horizontal direction under the driving voltage, the free end of the piezoelectric ceramic substrate is horizontally offset to the left relative to the fixed end; when the right side of the piezoelectric ceramic substrate is shortened in a horizontal direction under the driving voltage, the free end of the piezoelectric ceramic substrate is horizontally offset to the right relative to the fixed end.

[0017] In some other embodiments of the present invention, a driving electrode pair is disposed on both the left and right sides of the piezoelectric ceramic substrate, the driving electrode pair on the left side includes a first upper electrode layer disposed on the left side of the upper surface of the piezoelectric ceramic substrate and a first lower electrode layer disposed on the left side of the lower surface of the piezoelectric ceramic substrate, the first upper electrode layer and the first lower electrode layer are disposed opposite to each other, and after a driving voltage is applied through the first upper electrode layer and the first lower electrode layer, the left side of the piezoelectric ceramic substrate is extended or shortened in the horizontal direction under the driving of the driving voltage;

[0018] The driving electrode pair on the right side includes a second upper electrode layer arranged on the right side of the upper surface of the piezoelectric ceramic substrate and a second lower electrode layer arranged on the right side of the lower surface of the piezoelectric ceramic substrate. The upper electrode layer and the lower electrode layer are arranged opposite to each other. After a driving voltage is applied through the upper electrode layer and the lower electrode layer, the right side of the piezoelectric ceramic substrate is extended or shortened in the horizontal direction under the driving of the driving voltage.

[0019] At the same time, the right and left sides of the piezoelectric ceramic substrate extend and contract in opposite directions, that is, when the right side of the piezoelectric ceramic substrate extends in the horizontal direction under the driving voltage, the left side of the piezoelectric ceramic substrate shortens in the horizontal direction under the driving voltage, so that the free end of the piezoelectric ceramic substrate shifts horizontally to the left relative to the fixed end; when the right side of the piezoelectric ceramic substrate shortens in the horizontal direction under the driving voltage, the left side of the piezoelectric ceramic substrate extends in the horizontal direction under the driving voltage, and the free end of the piezoelectric ceramic substrate shifts horizontally to the right relative to the fixed end.

[0020] In some embodiments of the present invention, a piezoelectric drive layer is provided on the upper surface of the substrate, and a piezoelectric drive layer is not provided on the lower surface of the substrate. The piezoelectric drive layer includes a plurality of first electrodes and second electrodes arranged in sequence and cross-arranged in the front-to-back direction on the upper surface of the substrate, and a piezoelectric ceramic unit arranged between each adjacent first electrode and second electrode, each piezoelectric ceramic unit is polarized in the front-to-back direction, and the polarization directions of any two adjacent piezoelectric ceramic units are opposite, each first electrode is electrically connected to each other, and each second electrode is electrically connected to each other. The piezoelectric ceramic unit is a piezoelectric material polarized in the front-to-back direction. Preferably, the lower surface of the piezoelectric ceramic unit is tightly attached to the substrate, and the length of the piezoelectric ceramic unit extending in the left-to-right direction is equivalent to the width of the substrate in the left-to-right direction. Further preferably, the length of the portion of the upper surface of the substrate where the piezoelectric ceramic unit is arranged in the front-to-back direction is equivalent to the length of the substrate in the front-to-back direction, so that the area of ​​the piezoelectric drive layer is as full as possible on the upper surface of the substrate, and the volume of the device is minimized while meeting the performance requirements. Preferably, the first electrode and the second electrode are tightly attached to the front side or rear side of the adjacent piezoelectric ceramic unit.

[0021] Optionally, in some other embodiments of the present invention, a piezoelectric drive layer is provided on the lower surface of the substrate, and a piezoelectric drive layer is not provided on the upper surface of the substrate. The piezoelectric drive layer includes a plurality of first electrodes and second electrodes arranged in sequence and cross-arranged in the front-to-back direction on the lower surface of the substrate, and a piezoelectric ceramic unit arranged between each adjacent first electrode and second electrode, each piezoelectric ceramic unit is polarized in the front-to-back direction, and the polarization directions of any two adjacent piezoelectric ceramic units are opposite, each first electrode is electrically connected to each other, and each second electrode is electrically connected to each other. The piezoelectric ceramic unit is a piezoelectric material polarized in the front-to-back direction. Preferably, the lower surface of the piezoelectric ceramic unit is tightly attached to the substrate, and the length of the piezoelectric ceramic unit extending in the left-to-right direction is equivalent to the width of the substrate in the left-to-right direction. Further preferably, the length of the portion of the lower surface of the substrate where the piezoelectric ceramic unit is arranged in the front-to-back direction is equivalent to the length of the substrate in the front-to-back direction, so that the area of ​​the piezoelectric drive layer is as full as possible on the lower surface of the substrate, and the volume of the device is minimized while meeting the performance requirements. Preferably, the first electrode and the second electrode are tightly attached to the front side or rear side of the adjacent piezoelectric ceramic unit.

[0022] Optionally, in some other embodiments of the present invention, piezoelectric drive layers are provided on both the upper and lower surfaces of the substrate, and a first piezoelectric drive layer is provided on the upper surface of the substrate, the first piezoelectric drive layer includes a plurality of first electrodes and second electrodes arranged in sequence and cross-arranged along the front-to-back direction on the upper surface of the substrate, and a piezoelectric ceramic unit arranged between each adjacent first electrode and second electrode, each piezoelectric ceramic unit is polarized along the front-to-back direction, and the polarization directions of any two adjacent piezoelectric ceramic units are opposite, the first electrodes of the first piezoelectric drive layer are electrically connected to each other, and the second electrodes of the first piezoelectric drive layer are electrically connected to each other; a second piezoelectric drive layer is provided on the lower surface of the substrate, the second piezoelectric drive layer includes a plurality of first electrodes and second electrodes arranged in sequence and cross-arranged along the front-to-back direction on the lower surface of the substrate, and a piezoelectric ceramic unit arranged between each adjacent first electrode and second electrode, each piezoelectric ceramic unit is polarized along the front-to-back direction, and the polarization directions of any two adjacent piezoelectric ceramic units are opposite, the first electrodes of the second piezoelectric drive layer are electrically connected to each other, and the second electrodes of the second piezoelectric drive layer are electrically connected to each other.

[0023] The piezoelectric ceramic unit is a piezoelectric material polarized in the front-to-back direction. Preferably, the lower surface of the piezoelectric ceramic unit is tightly fitted on the substrate, and the length of the piezoelectric ceramic unit extending in the left-to-right direction is equivalent to the width of the substrate in the left-to-right direction. Further preferably, the length of the portion of the upper and lower surfaces of the substrate where the piezoelectric ceramic unit is arranged in the front-to-back direction is equivalent to the length of the substrate in the front-to-back direction, so that the area of ​​the piezoelectric drive layer covers the surface of the substrate as much as possible, and the volume of the device is minimized while meeting the performance requirements. Preferably, the first electrode and the second electrode are both tightly fitted to the front side or rear side of the adjacent piezoelectric ceramic unit.

[0024] A second aspect of the present invention provides an optical fiber scanner using the scanning actuator, which includes any one of the above-mentioned scanning actuators and an optical fiber, the optical fiber is fixedly connected to the free end of the first actuator part in a cantilever support manner, with the light emitting end of the optical fiber as the front end, the front part of the optical fiber exceeds the free end of the first actuator part to form a fiber optic cantilever, and the part of the optical fiber located on the rear side of the fiber optic cantilever is fixedly connected to the first actuator part.

[0025] The motion trajectory of the free end of the first actuating part relative to the fixed end of the second actuating part is a synthesis of the vibration trajectories of the second actuating part and the first actuating part, and the vibration direction of the free end of the second actuating part relative to its fixed end is perpendicular to the vibration direction of the free end of the first actuating part relative to its fixed end, so that the optical fiber cantilever can perform Lissajous scanning or grid scanning under the drive of the piezoelectric actuator. Preferably, the natural frequency of the first actuating part is much greater than the natural frequency of the second actuating part to meet the requirements of grid scanning, while also avoiding resonance interference between the second actuating part and the first actuating part.

[0026] Further preferably, the scanning actuator and the optical fiber are fixedly packaged in the housing, and the fixed end of the second actuator is fixedly connected to the housing. Further optionally, a corresponding lens group (not shown in the figure) is also fixed at the light output end of the packaging shell. When working, driven by the electrode, the optical fiber cantilever is driven to sweep at a set trajectory and set frequency, and at the same time, the end face of the optical fiber cantilever emits light to project a corresponding image. The scanning method here includes but is not limited to: raster scanning, spiral scanning, Lissajous scanning, etc.

[0027] One or more technical solutions in the embodiments of the present invention have at least the following technical effects or advantages:

[0028] The present invention makes the extension direction of the piezoelectric ceramic substrate of the fast axis actuator parallel to the fast axis vibration direction and the slow axis substrate. At the same time, there are no other layers on both sides of the piezoelectric ceramic substrate except the electrode layer. After dividing the left and right electrode areas, a single electrode pair is driven or two electrode pairs are reversely driven to achieve horizontal vibration. Since the fast axis has only a single-layer piezoelectric ceramic substrate, the expansion and contraction of one side of the single-layer piezoelectric ceramic substrate or the synchronous reverse expansion and contraction of both sides will only cause left and right vibrations in the horizontal direction, and the vertical vibration component is extremely small. Only simple driving is required to achieve horizontal swing of the fast axis, and basically no additional correction is required. At the same time, since the area of ​​the high-frequency driving electrode is reduced, the capacitance of the driving electrode is reduced, and the driving power consumption is greatly reduced. Compared with piezoelectric ceramic substrates with special-shaped three-dimensional structures such as tubular structures, sheet piezoelectric ceramic substrates are easier to achieve compactness, uniform material, good consistency, and high molding precision.

[0029] Each adjacent first electrode and second electrode of the slow axis actuator and the piezoelectric ceramic unit located between the first electrode and the second electrode constitute a driving unit, and the polarization direction of the piezoelectric ceramic unit is consistent with the overall expansion and contraction direction of the piezoelectric driving layer, so that the D33 directional variation of the piezoelectric ceramic unit can be used to drive the actuator to vibrate, which is nearly twice as large as the D32 or D31 directional variation of the piezoelectric ceramic unit, so that a larger swing can be achieved with a lower voltage, and the driving power consumption is also significantly reduced. Preferably, the first electrode and the second electrode completely cover the front end face or the rear end face of the piezoelectric ceramic unit, so that the entire piezoelectric ceramic unit is effectively driven.

[0030] At the same time, the present invention makes the second actuating part and the first actuating part both have a sheet (plate) structure with the same extension direction, so that a sheet actuator can achieve two-dimensional scanning, which can greatly reduce the negative impact of the fast and slow axis vibration coupling, and simplify the structure, reduce the complexity and difficulty of the processing technology, improve reliability, reduce costs, and facilitate mass production. The sheet structure has high molding and assembly accuracy, accurate packaging positioning, and can save the package lens adjustment mechanism, which is easy to mass produce. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is a schematic structural diagram of an exemplary optical fiber scanner in the prior art;

[0032] Figure 2a is a schematic structural diagram of an illustrative scanning display module provided by an embodiment of the present invention;

[0033] Figure 2b yes Figure 2a A schematic diagram of the structure of a fiber scanner in an illustrative scanning display module is shown;

[0034] Figure 3It is a schematic diagram of the structure of the scanning actuator and the optical fiber scanner of the present invention;

[0035] Figure 4 is a schematic diagram of a top view of the scanning actuator of the present invention;

[0036] Figure 5 A schematic structural diagram of an embodiment of a second actuating portion of a scanning actuator of the present invention;

[0037] Figure 6 is a schematic diagram of the vibration structure of the second actuating portion of the scanning actuator of the present invention;

[0038] Figure 7 is a structural schematic diagram of another embodiment of the second actuating portion of the scanning actuator of the present invention;

[0039] Figure 8 A schematic structural diagram of an embodiment of a first actuating portion of a scanning actuator of the present invention;

[0040] Fig. 9 is a schematic diagram of the vibration structure of the first actuating portion of the scanning actuator of the present invention;

[0041] Fig.10 is a structural schematic diagram of another embodiment of the first actuating portion of the scanning actuator of the present invention;

[0042] Fig.11 FIG. 4 is a schematic structural diagram of a third embodiment of the first actuating portion of the scanning actuator of the present invention. DETAILED DESCRIPTION

[0043] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0044] Illustrative Scanning Display Module

[0045] like Figure 2a As shown, it is an illustrative scanning display module in this application, which mainly includes:

[0046] Processor 100, laser group 110, fiber scanner 120, transmission fiber 130, light source modulation circuit 140, scanning drive circuit 150 and beam combining unit 160. Among them:

[0047] The processor 100 may be a graphics processing unit (GPU), a central processing unit (CPU), or other chips or circuits having control functions and image processing functions, which are not specifically limited here.

[0048] When the system is working, the processor 100 can control the light source modulation circuit 140 to modulate the laser group 110 according to the image data to be displayed. The laser group 110 includes multiple monochromatic lasers, which emit light beams of different colors. Figure 2a As can be seen in the figure, the laser group can specifically use three color lasers, namely red (Red, R), green (Green, G), and blue (Blue, B). The light beams emitted by the lasers in the laser group 110 are combined into a laser beam by the beam combining unit 160 and coupled into the transmission optical fiber 130.

[0049] The processor 100 may also control the scanning driving circuit 150 to drive the optical fiber scanner 120 to scan, thereby scanning and outputting the light beam transmitted in the transmission optical fiber 130 .

[0050] The light beam scanned and output by the optical fiber scanner 120 acts on a certain pixel position on the surface of the medium, and forms a light spot at the pixel position, thereby realizing the scanning of the pixel position. Under the action of the optical fiber scanner 120, the output end of the transmission optical fiber 130 sweeps according to a certain scanning trajectory, so that the light beam moves to the corresponding pixel position for scanning. In the actual scanning process, the light beam output by the transmission optical fiber 130 will form a light spot with corresponding image information (such as color, grayscale or brightness) at each pixel position. In one frame of time, the light beam traverses each pixel position at a sufficiently high speed to complete the scanning of one frame of image. Due to the characteristic of "visual residual" when the human eye observes things, the human eye cannot perceive the movement of the light beam at each pixel position, but sees a complete frame of image.

[0051] Continue to refer Figure 2b , which is a specific structure of the optical fiber scanner 120, including: an actuator 121, an optical fiber cantilever 122, a lens 123, a scanner package 124 and a fixing component 125. The actuator 121 is fixed in the scanner package 124 by the fixing component 125. The transmission optical fiber 130 extends from the free end of the actuator 121 to form the optical fiber cantilever 122 (also called scanning optical fiber). When working, the scanning actuator 121 is driven by the scanning driving signal along the vertical direction (the vertical direction is parallel to the scanning direction). Figure 2a , 2b The Y-axis in the reference coordinate system, in the embodiment of the present application, the vertical direction may also be referred to as the first direction) and the horizontal direction (the horizontal direction is parallel to Figure 2a ,2b The X-axis in the reference coordinate system (in the embodiment of the present application, the horizontal direction may also be referred to as the second direction) vibrates, and driven by the scanning actuator 121, the front end of the fiber optic cantilever 122 sweeps along a preset trajectory and emits a light beam, and the emitted light beam can be scanned and imaged through the lens 123.

[0052] It should be noted that in the embodiments of the present application, the rear end of the scanning actuator refers to the end of the scanning actuator that does not vibrate and is used for fixing, which can also be called the fixed end; the front end of the scanning actuator refers to the other end of the scanning actuator opposite to the rear end, which can also be called the free end, which is the part of the scanning actuator with the most significant deformation and amplitude. In addition, the light-emitting end of the optical fiber cantilever can also be called the front end of the optical fiber cantilever, or the free end of the optical fiber cantilever. It should be understood that such a description should not be used as a limitation of the present application.

[0053] The above-mentioned illustrative optical display module is an exemplary content. In actual application, the specific structure of the optical display module is not limited to Figure 2a , 2b What is shown may be changed, for example, the light source modulation circuit 140 and the scan drive circuit 150 may be combined into a processing circuit; or the processor 100 may be independent of the optical display module, rather than being a component unit in the optical display module, etc. Different variations will not be described one by one here.

[0054] As mentioned above, a slight increase in the power consumption of a single fiber scanner will significantly increase the overall power consumption, thus significantly increasing the equipment cost, usage cost, heat dissipation requirements, etc. Therefore, how to reduce the power consumption of a single scanner has become a technical problem that needs to be solved urgently.

[0055] To this end, an embodiment of the present invention provides a scanning actuator, such as Figure 3 , Figure 4 As shown, it includes a second actuating part 1 and a first actuating part 2 connected in sequence, as shown in FIG. Figure 5-7 As shown, the second actuating portion 1 includes a substrate 14, and a piezoelectric driving layer 13 arranged on the upper surface and / or the lower surface of the substrate 14, with the front and rear ends of the substrate 14 being the fixed end 11 and the free end 12 respectively, and the thickness direction of the substrate 14 being the vertical direction, the piezoelectric driving layer 13 includes a plurality of first electrodes 131 and second electrodes 132 sequentially arranged crosswise along the front-to-back direction, and a piezoelectric ceramic unit 133 arranged between each adjacent first electrode 131 and second electrode 132, each piezoelectric ceramic unit 133 is polarized along the front-to-back direction, and the polarization directions of any two adjacent piezoelectric ceramic units 133 are opposite, each first electrode 131 is electrically connected to each other, and each second electrode 132 is electrically connected to each other;

[0056] like Figure 8-Figure 11 As shown, the first actuator 2 includes a piezoelectric ceramic substrate 23, with the front and rear ends of the piezoelectric ceramic substrate 23 being a fixed end 21 and a free end 22 respectively, and the thickness direction of the piezoelectric ceramic substrate 23 being a vertical direction. At least one of the left side and the right side of the piezoelectric ceramic substrate 23 is provided with a driving electrode pair, and the driving electrode pair includes an upper electrode layer 24 provided on the upper surface of the piezoelectric ceramic substrate 23 and a lower electrode layer 25 provided on the lower surface of the piezoelectric ceramic substrate 23. The portion of the piezoelectric ceramic substrate 23 located between the driving electrode pairs is polarized in a vertical direction. The first actuator is driven by a lateral vibration mode in the width direction of the plate structure, with greater equivalent damping, wider response bandwidth, and smaller nonlinear effect, so that when the scanner is manufactured, the frequency matching of the optical fiber and the actuator is easier, and the adaptation range is wider, which is beneficial to improving the yield rate and manufacturing efficiency of the finished product, and it is easier to improve the consistency of the finished product;

[0057] The fixed end 21 of the piezoelectric ceramic substrate 23 is fixedly connected to the free end 12 of the substrate.

[0058] In a preferred embodiment, the first actuator 2 is a fast-axis actuator, and the second actuator 1 is a slow-axis actuator, and the vibration frequency of the fast-axis actuator is much greater than the vibration frequency of the slow-axis actuator. The present invention makes the extension direction of the piezoelectric ceramic substrate 23 of the fast-axis actuator parallel to the fast-axis vibration direction and the slow-axis substrate. At the same time, there are no other layers on both sides of the piezoelectric ceramic substrate 23 except the electrode layer. After dividing the left and right electrode areas, a single electrode pair is driven or two electrode pairs are reversely driven to achieve horizontal vibration. Since the fast axis has only a single-layer piezoelectric ceramic substrate 23, the expansion and contraction of a single side of the single-layer piezoelectric ceramic substrate 23 or the synchronous reverse expansion and contraction of both sides will only cause left and right vibrations in the horizontal direction, and the vibration component in the vertical direction is extremely small. Only simple driving is required to achieve horizontal swing of the fast axis, and basically no additional correction is required. At the same time, since the area of ​​the high-frequency driving electrode is reduced, the capacitance of the driving electrode is reduced, which greatly reduces the driving power consumption. The sheet-shaped piezoelectric ceramic substrate 23 is easier to achieve compactness, uniform material, good consistency, and high molding precision than a piezoelectric ceramic matrix with a tubular or other special-shaped three-dimensional structure.

[0059] Each adjacent first electrode 131 and second electrode 132 of the slow axis actuator, and the piezoelectric ceramic unit 133 located between the first electrode 131 and the second electrode 132 constitute a driving unit, and the polarization direction of the piezoelectric ceramic unit 133 is consistent with the overall expansion and contraction direction of the piezoelectric driving layer 13, so that the D33 directional deformation of the piezoelectric ceramic unit 133 can be used to drive the actuator to vibrate, which is nearly twice as large as the D32 or D31 directional deformation of the piezoelectric ceramic unit 133, so that a larger swing can be achieved with a lower voltage, and the driving power consumption is also significantly reduced. Preferably, the first electrode 131 and the second electrode 132 completely cover the front end face or the rear end face of the piezoelectric ceramic unit 133, so that the piezoelectric ceramic unit 133 is effectively driven as a whole.

[0060] At the same time, the present invention makes the second actuating part 1 and the first actuating part 2 both sheet-like (plate-like) structures extending in the same direction, so that a sheet-like actuator can achieve two-dimensional scanning, which can greatly reduce the negative impact of the fast and slow axis vibration coupling, and simplify the structure, reduce the complexity and difficulty of the processing technology, improve reliability, reduce costs, and facilitate mass production. The sheet-like structure has high molding and assembly accuracy, accurate packaging positioning, and can save the package lens adjustment mechanism, which is easy to mass produce.

[0061] Optionally, the substrate is a glass fiber board, a copper board or a steel board.

[0062] Thus, optionally, in some embodiments of the present invention, Figure 8 As shown, a driving electrode pair is arranged on the left side of the piezoelectric ceramic substrate 23, and no driving electrode pair is arranged on the right side of the piezoelectric ceramic substrate 23. The driving electrode pair includes an upper electrode layer 24 arranged on the left side of the upper surface of the piezoelectric ceramic substrate 23 and a lower electrode layer 25 arranged on the left side of the lower surface of the piezoelectric ceramic substrate 23. The upper electrode layer 24 and the lower electrode layer 25 are arranged opposite to each other. After a driving voltage is applied through the upper electrode layer 24 and the lower electrode layer 25, the left side of the piezoelectric ceramic substrate 23 is extended or shortened in the horizontal direction under the driving voltage. When the left side of the piezoelectric ceramic substrate 23 is extended in the horizontal direction under the driving voltage, the free end 22 of the piezoelectric ceramic substrate 23 is horizontally offset to the right relative to the fixed end 21; when the left side of the piezoelectric ceramic substrate 23 is shortened in the horizontal direction under the driving voltage, the free end 22 of the piezoelectric ceramic substrate 23 is horizontally offset to the left relative to the fixed end 21.

[0063] In some other embodiments of the present invention, Fig. 9As shown, a driving electrode pair is arranged on the right side of the piezoelectric ceramic substrate 23, and no driving electrode pair is arranged on the left side of the piezoelectric ceramic substrate 23. The driving electrode pair includes an upper electrode layer 24 arranged on the right side of the upper surface of the piezoelectric ceramic substrate 23 and a lower electrode layer 25 arranged on the right side of the upper surface of the piezoelectric ceramic substrate 23. The upper electrode layer 24 and the lower electrode layer 25 are arranged opposite to each other. After a driving voltage is applied through the upper electrode layer 24 and the lower electrode layer 25, the right side of the piezoelectric ceramic substrate 23 is extended or shortened in the horizontal direction under the driving voltage. When the right side of the piezoelectric ceramic substrate 23 is extended in the horizontal direction under the driving voltage, the free end 22 of the piezoelectric ceramic substrate 23 is horizontally offset to the left relative to the fixed end 21; when the right side of the piezoelectric ceramic substrate 23 is shortened in the horizontal direction under the driving voltage, the free end 22 of the piezoelectric ceramic substrate 23 is horizontally offset to the right relative to the fixed end 21.

[0064] In some other embodiments of the present invention, Fig.11 As shown, the left and right sides of the piezoelectric ceramic substrate 23 are both provided with driving electrode pairs, and the driving electrode pair on the left side includes a first upper electrode layer 24 provided on the left side of the upper surface of the piezoelectric ceramic substrate 23 and a first lower electrode layer 25 provided on the left side of the lower surface of the piezoelectric ceramic substrate 23. The first upper electrode layer 24 and the first lower electrode layer 25 are arranged opposite to each other. After a driving voltage is applied through the first upper electrode layer 24 and the first lower electrode layer 25, the left side of the piezoelectric ceramic substrate 23 is extended or shortened in the horizontal direction under the driving of the driving voltage.

[0065] The right driving electrode pair includes a second upper electrode layer 24 disposed on the right side of the upper surface of the piezoelectric ceramic substrate 23 and a second lower electrode layer 25 disposed on the right side of the lower surface of the piezoelectric ceramic substrate 23. The upper electrode layer 24 and the lower electrode layer 25 are disposed opposite to each other. After a driving voltage is applied through the upper electrode layer 24 and the lower electrode layer 25, the right side of the piezoelectric ceramic substrate 23 is extended or shortened in the horizontal direction under the driving voltage.

[0066] At the same time, the right and left sides of the piezoelectric ceramic substrate 23 extend and retract in opposite directions, that is, when the right side of the piezoelectric ceramic substrate 23 extends in the horizontal direction under the driving voltage, the left side of the piezoelectric ceramic substrate 23 shortens in the horizontal direction under the driving voltage, so that the free end 22 of the piezoelectric ceramic substrate 23 shifts horizontally to the left relative to the fixed end 21; when the right side of the piezoelectric ceramic substrate 23 shortens in the horizontal direction under the driving voltage, the left side of the piezoelectric ceramic substrate 23 extends in the horizontal direction under the driving voltage, and the free end 22 of the piezoelectric ceramic substrate 23 shifts horizontally to the right relative to the fixed end 21.

[0067] In some embodiments of the present invention, Figure 5As shown, the piezoelectric driving layer 13 is arranged on the upper surface of the substrate 14, and the piezoelectric driving layer 13 is not arranged on the lower surface of the substrate 14. The piezoelectric driving layer 13 includes a plurality of first electrodes 131 and second electrodes 132 arranged in sequence and cross-arranged in the front-to-back direction on the upper surface of the substrate 14, and a piezoelectric ceramic unit 133 arranged between each adjacent first electrode 131 and second electrode 132. Each piezoelectric ceramic unit 133 is polarized in the front-to-back direction, and the polarization directions of any two adjacent piezoelectric ceramic units 133 are opposite. Each first electrode 131 is electrically connected to each other, and each second electrode 132 is electrically connected to each other. The piezoelectric ceramic unit 133 is a piezoelectric material polarized in the front-to-back direction. Preferably, the lower surface of the piezoelectric ceramic unit 133 is tightly attached to the substrate 14, and the length of the piezoelectric ceramic unit 133 extending in the left-to-right direction is equivalent to the width of the substrate 14 in the left-to-right direction. Further preferably, the length of the portion of the upper surface of the substrate 14 where the piezoelectric ceramic unit 133 is arranged in the front-to-back direction is equal to the length of the substrate 14 in the front-to-back direction, so that the area of ​​the piezoelectric drive layer 13 covers the upper surface of the substrate 14 as much as possible, and the volume of the device is minimized while meeting the performance requirements. Preferably, the first electrode 131 and the second electrode 132 are both closely attached to the front side or the rear side of the adjacent piezoelectric ceramic unit 133.

[0068] Optionally, in some other embodiments of the present invention, the piezoelectric drive layer 13 is disposed on the lower surface of the substrate 14, and the piezoelectric drive layer 13 is not disposed on the upper surface of the substrate 14. The piezoelectric drive layer 13 includes a plurality of first electrodes 131 and second electrodes 132 disposed sequentially and crosswise in the front-to-back direction on the lower surface of the substrate 14, and a piezoelectric ceramic unit 133 disposed between each adjacent first electrode 131 and second electrode 132. Each piezoelectric ceramic unit 133 is polarized in the front-to-back direction, and the polarization directions of any two adjacent piezoelectric ceramic units 133 are opposite. Each first electrode 131 is electrically connected to each other, and each second electrode 132 is electrically connected to each other. The piezoelectric ceramic unit 133 is a piezoelectric material polarized in the front-to-back direction. Preferably, the lower surface of the piezoelectric ceramic unit 133 is tightly attached to the substrate 14, and the length of the piezoelectric ceramic unit 133 extending in the left-to-right direction is equivalent to the width of the substrate 14 in the left-to-right direction. Further preferably, the length of the portion of the lower surface of the substrate 14 where the piezoelectric ceramic unit 133 is arranged in the front-to-back direction is equal to the length of the substrate 14 in the front-to-back direction, so that the area of ​​the piezoelectric drive layer 13 covers the lower surface of the substrate 14 as much as possible, and the volume of the device is minimized while meeting the performance requirements. Preferably, the first electrode 131 and the second electrode 132 are both closely attached to the front side or the rear side of the adjacent piezoelectric ceramic unit 133.

[0069] Alternatively, in some other embodiments of the present invention, Figure 7As shown, the upper and lower surfaces of the substrate 14 are both provided with a piezoelectric drive layer 13, the upper surface of the substrate 14 is provided with a first piezoelectric drive layer 13, the first piezoelectric drive layer 13 includes a plurality of first electrodes 131 and a second electrode 132 arranged in sequence and cross-arranged along the front-to-back direction on the upper surface of the substrate 14, and a piezoelectric ceramic unit 133 arranged between each adjacent first electrode 131 and second electrode 132, each piezoelectric ceramic unit 133 is polarized along the front-to-back direction, and the polarization directions of any two adjacent piezoelectric ceramic units 133 are opposite, each first electrode 131 of the first piezoelectric drive layer 13 is electrically connected to each other, and each piezoelectric ceramic unit 133 of the first piezoelectric drive layer 13 is electrically connected to each other. The second electrodes 132 are all electrically connected to each other; a second piezoelectric driving layer 13 is arranged on the lower surface of the substrate 14, and the second piezoelectric driving layer 13 includes a plurality of first electrodes 131 and second electrodes 132 arranged in sequence and cross-arranged in the front-to-back direction on the lower surface of the substrate 14, and a piezoelectric ceramic unit 133 arranged between each adjacent first electrode 131 and second electrode 132, each piezoelectric ceramic unit 133 is polarized in the front-to-back direction, and the polarization directions of any two adjacent piezoelectric ceramic units 133 are opposite, the first electrodes 131 of the second piezoelectric driving layer 13 are all electrically connected to each other, and the second electrodes 132 of the second piezoelectric driving layer 13 are all electrically connected to each other.

[0070] The piezoelectric ceramic unit 133 is a piezoelectric material polarized in the front-to-back direction. Preferably, the lower surface of the piezoelectric ceramic unit 133 is tightly attached to the substrate 14, and the length of the piezoelectric ceramic unit 133 extending in the left-right direction is equivalent to the width of the substrate 14 in the left-to-right direction. Further preferably, the length of the portion of the upper and lower surfaces of the substrate 14 where the piezoelectric ceramic unit 133 is arranged in the front-to-back direction is equivalent to the length of the substrate 14 in the front-to-back direction, so that the area of ​​the piezoelectric drive layer 13 covers the surface of the substrate 14 as much as possible, and the volume of the device is minimized while meeting the performance requirements. Preferably, the first electrode 131 and the second electrode 132 are tightly attached to the front side or rear side of the adjacent piezoelectric ceramic unit 133.

[0071] A second aspect of the present invention provides an optical fiber scanner using the scanning actuator, such as Figure 3 As shown, it includes any one of the above-mentioned scanning actuators and optical fibers, the optical fiber is fixedly connected to the free end of the first actuator part 2 in a cantilever support manner, with the light emitting end of the optical fiber as the front end, the front part of the optical fiber exceeds the free end of the first actuator part 2 to form an optical fiber cantilever 3, and the part of the optical fiber located at the rear side of the optical fiber cantilever 3 is fixedly connected to the first actuator part 2.

[0072] The motion trajectory of the free end of the first actuating part 2 relative to the fixed end of the second actuating part 1 is a synthesis of the vibration trajectories of the second actuating part 1 and the first actuating part 2. The vibration direction of the free end of the second actuating part 1 relative to its fixed end is perpendicular to the vibration direction of the free end of the first actuating part 2 relative to its fixed end, so that the optical fiber cantilever 3 can perform Lissajous scanning or grid scanning under the drive of the piezoelectric actuator. Preferably, the natural frequency of the first actuating part 2 is much greater than the natural frequency of the second actuating part 1 to meet the requirements of grid scanning, while also avoiding resonance interference between the second actuating part 1 and the first actuating part 2.

[0073] Further preferably, the scanning actuator and the optical fiber are fixedly packaged in the housing 4, and the fixed end of the second actuator 1 is fixedly connected to the housing 4. Further optionally, a corresponding lens group (not shown in the figure) is also fixed at the light output end of the packaging shell. When working, driven by the electrode, the optical fiber cantilever 3 is driven to sweep at a set trajectory and a set frequency, and at the same time, the end face of the optical fiber cantilever 3 emits light to project a corresponding image. The scanning method here includes but is not limited to: raster scanning, spiral scanning, Lissajous scanning, etc.

[0074] Of course, in some embodiments, the number of scanning optical fibers is at least one, and may be two or more, and there is no specific limitation here.

[0075] It should be noted that the above embodiments illustrate the present invention rather than limit it, and that those skilled in the art may devise alternative embodiments without departing from the scope of the appended claims. In the claims, any reference symbol between brackets should not be constructed as a limitation to the claims. The words "comprise" or "include" do not exclude the presence of elements or steps not listed in the claims. The word "one" 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 indicate any order, and these words may be interpreted as names.

[0076] All features disclosed in this specification, except mutually exclusive features, can be combined in any way.

[0077] Any feature disclosed in this specification (including any additional claims, abstract and drawings), unless otherwise stated, may be replaced by other equivalent or alternative features with similar purposes. That is, unless otherwise stated, each feature is only an example of a series of equivalent or similar features.

[0078] The present invention is not limited to the above-mentioned specific embodiments, but extends to any new features or any new combination disclosed in this specification, as well as any new method or process steps or any new combination disclosed.

Claims

1. A scanning actuator, characterized in that: The invention comprises a first actuating part, wherein the first actuating part comprises a piezoelectric ceramic substrate, wherein the front and rear ends of the piezoelectric ceramic substrate are respectively a fixed end and a free end, and the thickness direction of the piezoelectric ceramic substrate is a vertical direction, and at least one of the left side and the right side of the piezoelectric ceramic substrate is provided with a driving electrode pair, wherein the driving electrode pair comprises an upper electrode layer provided on the upper surface of the piezoelectric ceramic substrate and a lower electrode layer provided on the lower surface of the piezoelectric ceramic substrate, and a portion of the piezoelectric ceramic substrate located between the driving electrode pairs is polarized in a vertical direction; It also includes a second actuating portion, the second actuating portion includes a substrate and a piezoelectric driving layer arranged on the upper surface and / or the lower surface of the substrate, with the front and rear ends of the substrate being a fixed end and a free end respectively, and the thickness direction of the substrate being a vertical direction, the piezoelectric driving layer includes a plurality of first electrodes and second electrodes sequentially arranged crosswise along the front-to-back direction, and a piezoelectric ceramic unit arranged between each adjacent first electrode and second electrode, each piezoelectric ceramic unit is polarized along the front-to-back direction, and the polarization directions of any two adjacent piezoelectric ceramic units are opposite, each first electrode is electrically connected to each other, and each second electrode is electrically connected to each other; The fixed end of the piezoelectric ceramic substrate is fixedly connected to the free end of the substrate.

2. A scanning actuator as claimed in claim 1, characterized in that: A driving electrode pair is arranged on the left side of the piezoelectric ceramic substrate, and no driving electrode pair is arranged on the right side of the piezoelectric ceramic substrate. The driving electrode pair includes an upper electrode layer arranged on the left side of the upper surface of the piezoelectric ceramic substrate and a lower electrode layer arranged on the left side of the lower surface of the piezoelectric ceramic substrate. The upper electrode layer and the lower electrode layer are arranged opposite to each other. After a driving voltage is applied through the upper electrode layer and the lower electrode layer, the left side of the piezoelectric ceramic substrate is extended or shortened in the horizontal direction under the driving of the driving voltage.

3. A scanning actuator as claimed in claim 1, characterized in that: A driving electrode pair is arranged on the right side of the piezoelectric ceramic substrate, and no driving electrode pair is arranged on the left side of the piezoelectric ceramic substrate. The driving electrode pair includes an upper electrode layer arranged on the right side of the upper surface of the piezoelectric ceramic substrate and a lower electrode layer arranged on the right side of the lower surface of the piezoelectric ceramic substrate. The upper electrode layer and the lower electrode layer are arranged opposite to each other. After a driving voltage is applied through the upper electrode layer and the lower electrode layer, the right side of the piezoelectric ceramic substrate is extended or shortened in the horizontal direction under the driving of the driving voltage.

4. A scanning actuator as claimed in claim 1, characterized in that: The piezoelectric ceramic substrate is provided with a driving electrode pair on both the left and right sides, the driving electrode pair on the left side includes a first upper electrode layer provided on the left side of the upper surface of the piezoelectric ceramic substrate and a first lower electrode layer provided on the left side of the lower surface of the piezoelectric ceramic substrate, the first upper electrode layer and the first lower electrode layer are arranged opposite to each other, after a driving voltage is applied through the first upper electrode layer and the first lower electrode layer, the left side of the piezoelectric ceramic substrate is extended or shortened in the horizontal direction under the driving of the driving voltage; The driving electrode pair on the right side includes a second upper electrode layer arranged on the right side of the upper surface of the piezoelectric ceramic substrate and a second lower electrode layer arranged on the right side of the lower surface of the piezoelectric ceramic substrate. The upper electrode layer and the lower electrode layer are arranged opposite to each other. After a driving voltage is applied through the upper electrode layer and the lower electrode layer, the right side of the piezoelectric ceramic substrate is extended or shortened in the horizontal direction under the driving of the driving voltage. At the same time, the right and left sides of the piezoelectric ceramic substrate expand and contract in opposite directions.

5. A scanning actuator as claimed in claim 1, characterized in that: A piezoelectric driving layer is arranged on the upper surface of the substrate of the second actuator part, and no piezoelectric driving layer is arranged on the lower surface of the substrate. The piezoelectric driving layer includes a plurality of first electrodes and second electrodes arranged in sequence and cross-arranged in the front-to-back direction on the upper surface of the substrate, and a piezoelectric ceramic unit arranged between each adjacent first electrode and second electrode. Each piezoelectric ceramic unit is polarized in the front-to-back direction, and the polarization directions of any two adjacent piezoelectric ceramic units are opposite. Each first electrode is electrically connected to each other, and each second electrode is electrically connected to each other.

6. A scanning actuator as claimed in claim 1, characterized in that: A piezoelectric driving layer is arranged on the lower surface of the substrate of the second actuator part, and no piezoelectric driving layer is arranged on the upper surface of the substrate. The piezoelectric driving layer includes a plurality of first electrodes and second electrodes arranged in sequence and cross-arranged in the front-to-back direction on the lower surface of the substrate, and a piezoelectric ceramic unit arranged between each adjacent first electrode and second electrode. Each piezoelectric ceramic unit is polarized in the front-to-back direction, and the polarization directions of any two adjacent piezoelectric ceramic units are opposite. Each first electrode is electrically connected to each other, and each second electrode is electrically connected to each other.

7. A scanning actuator as claimed in claim 1, characterized in that: Piezoelectric drive layers are provided on the upper and lower surfaces of the substrate of the second actuating portion. A first piezoelectric drive layer is provided on the upper surface of the substrate. The first piezoelectric drive layer includes a plurality of first electrodes and second electrodes arranged in sequence and cross-arranged along the front-to-back direction on the upper surface of the substrate, and a piezoelectric ceramic unit arranged between each adjacent first electrode and second electrode. Each piezoelectric ceramic unit is polarized along the front-to-back direction, and the polarization directions of any two adjacent piezoelectric ceramic units are opposite. The first electrodes of the first piezoelectric drive layer are electrically connected to each other, and the second electrodes of the first piezoelectric drive layer are electrically connected to each other. A second piezoelectric drive layer is provided on the lower surface of the substrate. The second piezoelectric drive layer includes a plurality of first electrodes and second electrodes arranged in sequence and cross-arranged along the front-to-back direction on the lower surface of the substrate, and a piezoelectric ceramic unit arranged between each adjacent first electrode and second electrode. Each piezoelectric ceramic unit is polarized along the front-to-back direction, and the polarization directions of any two adjacent piezoelectric ceramic units are opposite. The first electrodes of the second piezoelectric drive layer are electrically connected to each other, and the second electrodes of the second piezoelectric drive layer are electrically connected to each other.

8. A fiber optic scanner, characterized in that: It comprises a scanning actuator and optical fiber as described in any one of claims 1 to 7, wherein the optical fiber is fixedly connected to the free end of the first actuator part in a cantilever supported manner, with the light emitting end of the optical fiber as the front end, the front part of the optical fiber protruding beyond the free end of the first actuator part to form an optical fiber cantilever, and the part of the optical fiber located at the rear side of the optical fiber cantilever is fixedly connected to the first actuator part.

9. The optical fiber scanner according to claim 8, characterized in that: The scanning actuator and the optical fiber are fixedly packaged in the housing, and the fixed end of the second actuating part is fixedly connected to the housing.

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