A scanning actuator and fiber scanner

Abstract

The application discloses a scanning actuator, which comprises a first piezoelectric ceramic sheet and a second piezoelectric ceramic sheet, both of which are plate-shaped, the length of the second piezoelectric ceramic sheet is less than that of the first piezoelectric ceramic sheet, and the second piezoelectric ceramic sheet is fixedly attached to the back side of the upper surface or the lower surface of the first piezoelectric ceramic sheet; under the drive of the first piezoelectric ceramic sheet and the second piezoelectric ceramic sheet, the free end of the scanning actuator makes two-dimensional scanning vibration relative to the fixed end. The two-dimensional scanning actuator is formed by two piezoelectric ceramic sheets through attachment, the first piezoelectric ceramic sheet and the second piezoelectric ceramic sheet are both single ceramic sheets, which facilitates manufacturing and processing and is easy to ensure the consistency of product specifications, performance and parameters in batch production; the sheet-shaped structure makes the difference between the characteristic frequency values of the actuator in the horizontal direction and the vertical direction very large, and can greatly reduce the vibration coupling in the two vibration directions.

Description

Technical Field

[0001] This invention relates to the field of fiber optic scanning technology, and more particularly to a scanning actuator and a fiber optic scanner. Background Technology

[0002] A fiber optic scanner is a display technology that uses a scanning actuator to control the oscillation of an optical fiber to project a pattern. The pattern projected by this technology has sharp and saturated colors, high contrast, high brightness, and a very small structural size. It is mainly used in fiber optic scanning display (FSD) technology and fiber optic scanning endoscopy (FSE) technology.

[0003] The actuator of a grid-type fiber optic scanner mainly consists of a second actuator (fast axis) and a first actuator (slow axis). Both the second and first actuators have a fixed end and a free end, respectively, with the fixed end of the second actuator fixedly connected to the free end of the first actuator. To obtain a stable scanning range and precisely control the scanning trajectory, the scanning trajectory at the actuator's end must be precisely consistent with the scanning trajectories of both the first and second actuators. Any machining error in the actuator will make the actuator's vibration difficult to control or generate random vibration components. Avoiding uncontrolled or random vibration components is one of the important factors in improving scanning quality.

[0004] Traditional scanner actuators are generally tubular or plate-shaped. In order to ensure that the actuator in the slow axis direction meets the slow axis scanning frequency and the actuator in the fast axis direction meets the fast axis scanning frequency, the shape and size of the actuator must be designed accordingly, which results in the actuator being an irregular shape.

[0005] For example, Chinese patent CN111830702A discloses a scanning actuator that generally uses a tubular piezoelectric actuator. However, due to the aforementioned constraints, its design results in an irregular shape, which is quite disadvantageous for mass production of the actuator, making it difficult to manufacture and compromising manufacturing consistency. Similarly, Chinese patent CN209784655U discloses a scanning actuator that generally uses a sheet-like piezoelectric actuator. Again, for performance reasons, the actuator is also designed as an irregular shape, similarly suffering from the aforementioned technical problems of difficult precision manufacturing and poor manufacturing consistency.

[0006] Meanwhile, how to avoid vibration coupling between the slow-axis actuator and the fast-axis actuator is also a technical problem that needs to be considered. The two existing technologies mentioned above do not offer any corresponding design for reducing vibration coupling between the slow-axis actuator and the fast-axis actuator.

[0007] Therefore, the technical problem that needs to be solved is how to improve the actuator's ease of manufacturing, ease of mass production, and good consistency in mass production, while ensuring that each actuating component meets its performance parameters and does not generate vibration coupling. Summary of the Invention

[0008] This invention provides a scanning actuator and a fiber optic scanner to at least solve the technical problems of actuators with good anti-vibration coupling being difficult to mass-produce and having poor consistency in mass production.

[0009] To achieve the aforementioned objectives, a first aspect of the present invention provides a scanning actuator, comprising a first piezoelectric ceramic sheet and a second piezoelectric ceramic sheet, both of which are plate-shaped.

[0010] With the plane where the first piezoelectric ceramic sheet is located as the horizontal plane, and the front and rear ends of the first piezoelectric ceramic sheet as the free end and fixed end of the scanning actuator, respectively;

[0011] The second piezoelectric ceramic sheet is shorter in the front-to-back direction than the first piezoelectric ceramic sheet. The second piezoelectric ceramic sheet is fixedly attached to the rear side of the upper or lower surface of the first piezoelectric ceramic sheet.

[0012] Driven by the first and second piezoelectric ceramic sheets, the free end of the scanning actuator performs two-dimensional scanning vibration relative to its fixed end.

[0013] This application uses two piezoelectric ceramic sheets bonded together to form a two-dimensional scanning actuator. Both components, the first and second piezoelectric ceramic sheets, are single ceramic sheets, which are convenient to manufacture and process. In mass production, it is easy to ensure the consistency of product specifications, performance, and parameters. For fiber optic scanning imaging technology, good actuator consistency is one of the key factors for the mass production of fiber optic scanners.

[0014] Meanwhile, the sheet-like structure results in 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.

[0015] Specifically, both the first and second piezoelectric ceramic sheets are polarized along the thickness direction.

[0016] The first piezoelectric ceramic sheet has a first actuation region located on the front side and a second actuation region located on the rear side.

[0017] The second piezoelectric ceramic sheet is arranged parallel to the first piezoelectric ceramic sheet and is fixedly attached to it directly above or below the second actuation area of ​​the first piezoelectric ceramic sheet.

[0018] The first telescopic area and the second telescopic area are respectively provided on the left and right sides of the first moving area.

[0019] The second actuation region, the first telescopic region, the second telescopic region of the first piezoelectric ceramic sheet, and the upper and lower surfaces of the second piezoelectric ceramic sheet are all provided with upper and lower electrodes respectively. The second actuation region, the first telescopic region, the second telescopic region of the first piezoelectric ceramic sheet, and the second piezoelectric ceramic sheet all extend and retract in the front-back direction.

[0020] Furthermore, the second actuation region of the first piezoelectric ceramic sheet and the second piezoelectric ceramic sheet extend and retract synchronously in opposite directions, and the first extension and retraction region and the second extension and retraction region of the first piezoelectric ceramic sheet extend and retract synchronously in opposite directions.

[0021] Thus, the second actuation region of the first piezoelectric ceramic sheet and the second piezoelectric ceramic sheet synchronously extend and retract in opposite directions, driving the free end of the first piezoelectric ceramic sheet to vibrate in the vertical direction, and the first extension and retraction regions and the second extension and retraction regions of the first piezoelectric ceramic sheet synchronously extend and retract in opposite directions, driving the free end of the first piezoelectric ceramic sheet to vibrate in the left and right direction.

[0022] The second actuation region of the first piezoelectric ceramic sheet and the second piezoelectric ceramic sheet only extend and retract synchronously in opposite directions, and neither of the left nor right end faces is constrained. Therefore, the aforementioned synchronous reverse extension and retraction only causes vibration in the vertical direction and does not generate vibration components in the horizontal left and right directions. Similarly, the first extension and retraction regions and the second extension and retraction regions of the first piezoelectric ceramic sheet only extend and retract synchronously in opposite directions, and neither of the upper nor lower surfaces is constrained. Therefore, the aforementioned synchronous reverse extension and retraction only causes vibration in the horizontal left and right directions and does not generate vibration components in the vertical direction. Therefore, the actuator of this application does not require an additional correction structure.

[0023] In this application, the left and right sides of the first actuation region of the first piezoelectric ceramic sheet are respectively the first telescopic region and the second telescopic region, and driving electrodes are set in the two regions respectively. This structure greatly reduces the area of ​​the driving electrode, thereby reducing the capacitance of the driving electrode and greatly reducing the driving power consumption.

[0024] The second actuation region, the first extension region, the second extension region of the first piezoelectric ceramic sheet, and the upper and lower surfaces of the second piezoelectric ceramic sheet are all provided with upper and lower electrodes respectively. Each upper electrode and each lower electrode is used to connect to the corresponding external driving circuit through electrode leads to drive the second actuation region, the first extension region, the second extension region, and the second piezoelectric ceramic sheet to extend and retract in the front-back direction.

[0025] The first piezoelectric ceramic sheet has a first upper electrode on its upper surface and a first lower electrode on its lower surface in the first telescopic region. The second telescopic region of the first piezoelectric ceramic sheet has a second upper electrode on its upper surface and a second lower electrode on its lower surface. The second actuation region of the first piezoelectric ceramic sheet has a third upper electrode on its upper surface and a third lower electrode on its lower surface. The second piezoelectric ceramic sheet has a fourth upper electrode on its upper surface and a fourth lower electrode on its lower surface.

[0026] Optionally, the first and second telescopic regions of the first piezoelectric ceramic sheet may share a common upper or lower electrode. The common upper or lower electrode simultaneously covers both the first and second telescopic regions, resulting in the first and second telescopic regions of the first piezoelectric ceramic sheet having only three electrode leads. Two driving signals drive the first and second telescopic regions to telescopically extend and retract synchronously in opposite directions, respectively.

[0027] Further preferably, the polarization directions of the first and second telescopic regions of the first piezoelectric ceramic sheet are opposite. Since the first and second telescopic regions telescopicate synchronously in opposite directions, they can share a common fifth upper electrode and a fifth lower electrode. Specifically, the fifth upper electrode coated on the upper surface of the first actuation region of the first piezoelectric ceramic sheet simultaneously covers both the first and second telescopic regions; similarly, the fifth lower electrode coated on the lower surface of the first actuation region simultaneously covers both the first and second telescopic regions. The shared fifth upper and fifth lower electrodes are each connected to an electrode lead, allowing a single drive signal to simultaneously drive the first and second telescopic regions to telescopicate synchronously in opposite directions via both leads.

[0028] Similarly, alternatively, the second actuation region of the first piezoelectric ceramic sheet and the second piezoelectric ceramic sheet can share a common intermediate electrode. The intermediate electrode is disposed between the second actuation region and the second piezoelectric ceramic sheet. This intermediate electrode is both the upper electrode of the second actuation region and the lower electrode of the second piezoelectric ceramic sheet. This allows the second actuation region of the first piezoelectric ceramic sheet and the second piezoelectric ceramic sheet to have only three electrode leads, simplifying the circuit. The second actuation region and the second piezoelectric ceramic sheet can be driven to synchronously extend and retract in opposite directions by two driving signals respectively.

[0029] Further preferred from this point, the second actuation region of the first piezoelectric ceramic sheet has the same polarization direction as the second piezoelectric ceramic sheet. Since the second actuation region and the second piezoelectric ceramic sheet perform synchronous reverse expansion and contraction, in addition to the second actuation region and the second piezoelectric ceramic sheet sharing a common intermediate electrode, the remaining two electrodes of the second actuation region and the second piezoelectric ceramic sheet can also share a common electrode lead. This allows the second actuation region and the second piezoelectric ceramic sheet to be driven to perform synchronous reverse expansion and contraction simultaneously by a single drive signal passing through the two leads.

[0030] A second aspect of this application provides a fiber optic scanner, comprising the aforementioned scanning actuator and an optical fiber. The optical fiber is fixedly mounted on the front end of a first piezoelectric ceramic sheet in a cantilevered manner. The other end of the optical fiber is connected to a light source. The optical fiber cantilever performs a two-dimensional scan under the drive of the scanning actuator. The light source emits light corresponding to the pixel point according to the scanning position of the optical fiber cantilever, thereby realizing fiber optic two-dimensional scanning imaging.

[0031] One or more technical solutions in the embodiments of the present invention have at least the following technical effects or advantages:

[0032] This application uses two piezoelectric ceramic sheets bonded together to form a two-dimensional scanning actuator. Both components, the first and second piezoelectric ceramic sheets, are single ceramic sheets, which are convenient to manufacture and process. In mass production, it is easy to ensure the consistency of product specifications, performance, and parameters. For fiber optic scanning imaging technology, good actuator consistency is one of the key factors for the mass production of fiber optic scanners.

[0033] Meanwhile, the sheet-like structure results in 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.

[0034] The second actuation region of the first piezoelectric ceramic sheet and the second piezoelectric ceramic sheet only extend and retract synchronously in opposite directions, and neither of the left nor right end faces is constrained. Therefore, the aforementioned synchronous reverse extension and retraction only causes vibration in the vertical direction and does not generate vibration components in the horizontal left and right directions. Similarly, the first extension and retraction regions and the second extension and retraction regions of the first piezoelectric ceramic sheet only extend and retract synchronously in opposite directions, and neither of the upper nor lower surfaces is constrained. Therefore, the aforementioned synchronous reverse extension and retraction only causes vibration in the horizontal left and right directions and does not generate vibration components in the vertical direction. Therefore, the actuator of this application does not require an additional correction structure.

[0035] In this application, the left and right sides of the first actuation region of the first piezoelectric ceramic sheet are respectively the first telescopic region and the second telescopic region, and driving electrodes are set in the two regions respectively. This structure greatly reduces the area of ​​the driving electrode, thereby reducing the capacitance of the driving electrode and greatly reducing the driving power consumption. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the scanning actuator of the present invention;

[0037] Figure 2 This is a schematic diagram of the structure of the first piezoelectric ceramic sheet of the present invention;

[0038] Figure 3 This is a schematic diagram of the electrode structure of the scanning actuator of the present invention;

[0039] Figure 4A schematic diagram of a structure in which the first actuation region of the first piezoelectric ceramic sheet shares an upper electrode;

[0040] Figure 5 A schematic diagram of the structure of the first actuation region of the first piezoelectric ceramic sheet sharing the lower electrode;

[0041] Figure 6 A schematic diagram of a structure in which the first actuation region of the first piezoelectric ceramic sheet shares both the upper and lower electrodes;

[0042] Figure 7 This is a schematic diagram of a structure in which the second piezoelectric ceramic sheet and the second actuation region of the first piezoelectric ceramic sheet share an intermediate electrode.

[0043] Figure 8 This is a schematic diagram of the fiber optic scanner of the present invention;

[0044] Figure 9 This is a schematic diagram of another embodiment of the scanning actuator of the present invention. Detailed Implementation

[0045] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0046] like Figure 1 According to the first aspect of the present invention, a scanning actuator is provided, comprising a first piezoelectric ceramic sheet 100 and a second piezoelectric ceramic sheet 200, both of which are plate-shaped.

[0047] With the plane where the first piezoelectric ceramic sheet 100 is located as the horizontal plane, and the front and rear ends of the first piezoelectric ceramic sheet 100 as the free end and fixed end of the scanning actuator, respectively;

[0048] The length of the second piezoelectric ceramic sheet 200 in the front-to-back direction is less than the length of the first piezoelectric ceramic sheet 100 in the front-to-back direction. The second piezoelectric ceramic sheet 200 is fixedly attached to the rear side of the first piezoelectric ceramic sheet 100.

[0049] Driven by the first piezoelectric ceramic sheet 100 and the second piezoelectric ceramic sheet 200, the free end of the scanning actuator performs two-dimensional scanning vibration relative to its fixed end.

[0050] This application uses two piezoelectric ceramic sheets bonded together to form a two-dimensional scanning actuator. Both components, the first piezoelectric ceramic sheet 100 and the second piezoelectric ceramic sheet 200, are single ceramic sheets, which are convenient to manufacture and process. In mass production, it is easy to ensure the consistency of product specifications, performance and parameters. For fiber optic scanning imaging technology, good actuator consistency is one of the key factors for the mass production of fiber optic scanners.

[0051] Meanwhile, the sheet-like structure results in 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.

[0052] Specifically, in combination Figure 2 As shown, both the first piezoelectric ceramic sheet 100 and the second piezoelectric ceramic sheet 200 are polarized along the thickness direction. The first piezoelectric ceramic sheet 100 has a first actuation region 101 located on the front side and a second actuation region 102 located on the rear side.

[0053] The second piezoelectric ceramic sheet 200 is arranged parallel to and fixedly attached to the first piezoelectric ceramic sheet 100, directly above or below the second actuation region 102 of the first piezoelectric ceramic sheet 100. It should be noted that the embodiments described below all illustrate examples where the second piezoelectric ceramic sheet 200 is positioned above the first piezoelectric ceramic sheet 100. This is merely an illustrative description of the technical solution. However, it is understood that the second piezoelectric ceramic sheet 200 positioned below the first piezoelectric ceramic sheet 100 is also a similar technical solution, which is obvious to those skilled in the art. Figure 9 As shown.

[0054] The second piezoelectric ceramic sheet 200 and the first piezoelectric ceramic sheet 100 can be fixedly connected by adhesive bonding or by ultrasonic welding, and there is no restriction on the method of fixed connection.

[0055] The first telescopic region 101 is provided with a first telescopic region 1011 and a second telescopic region 1012 on the left and right sides respectively.

[0056] The second actuation region 102, the first telescopic region 1011, the second telescopic region 1012 of the first piezoelectric ceramic sheet 100, and the upper and lower surfaces of the second piezoelectric ceramic sheet 200 are all provided with upper and lower electrodes respectively. Each upper electrode and each lower electrode is used to connect to the corresponding external driving circuit through electrode leads to drive the second actuation region 102, the first telescopic region 1011, the second telescopic region 1012 of the first piezoelectric ceramic sheet 100, and the second piezoelectric ceramic sheet 200 to extend and retract in the front-back direction respectively.

[0057] Furthermore, the second actuation region 102 of the first piezoelectric ceramic sheet 100 and the second piezoelectric ceramic sheet 200 extend and retract synchronously in opposite directions, and the first extension region 1011 and the second extension region 1012 of the first piezoelectric ceramic sheet 100 extend and retract synchronously in opposite directions.

[0058] Thus, the second actuation region 102 of the first piezoelectric ceramic sheet 100 and the second piezoelectric ceramic sheet 200 synchronously extend and retract in opposite directions, driving the free end of the first piezoelectric ceramic sheet 100 to vibrate in the vertical direction, and the first extension region 1011 and the second extension region 1012 of the first piezoelectric ceramic sheet 100 synchronously extend and retract in opposite directions, driving the free end of the first piezoelectric ceramic sheet 100 to vibrate in the left and right direction.

[0059] The second actuation region 102 of the first piezoelectric ceramic sheet 100 and the second piezoelectric ceramic sheet 200 only extend and retract synchronously in opposite directions, and neither of their left nor right end faces is constrained. Therefore, the aforementioned synchronous reverse extension and retraction only causes vibration in the vertical direction and does not generate vibration components in the horizontal left and right directions. Similarly, the first extension region 1011 and the second extension region 1012 of the first piezoelectric ceramic sheet 100 only extend and retract synchronously in opposite directions, and neither of their upper nor lower surfaces is constrained. Therefore, the aforementioned synchronous reverse extension and retraction only causes vibration in the horizontal left and right directions and does not generate vibration components in the vertical direction. Therefore, the actuator of this application does not require an additional correction structure.

[0060] In this application, the first actuation region 101 of the first piezoelectric ceramic sheet 100 is divided into a first telescopic region 1011 and a second telescopic region 1012 on the left and right sides respectively, and driving electrodes are set in the two regions respectively. This structure greatly reduces the area of ​​the driving electrode, thereby reducing the capacitance of the driving electrode and greatly reducing the driving power consumption.

[0061] like Figure 3 In the illustrated embodiment, the upper surface of the first telescopic region 1011 of the first piezoelectric ceramic sheet 100 is provided with a first upper electrode 301, and the lower surface is provided with a first lower electrode 302. The upper surface of the second telescopic region 1012 of the first piezoelectric ceramic sheet 100 is provided with a second upper electrode 303, and the lower surface is provided with a second lower electrode 304. The upper surface of the second actuation region 102 of the first piezoelectric ceramic sheet 100 is provided with a third upper electrode 305, and the lower surface is provided with a third lower electrode 306. The upper surface of the second piezoelectric ceramic sheet 200 is provided with a fourth upper electrode 307, and the lower surface is provided with a fourth lower electrode 308. Of course, the third upper electrode 305 and the fourth lower electrode 308 need to be provided with an insulating structure, such as by coating an insulating layer on the electrode surface, which is common knowledge in the art. For each upper and lower electrode in this application, they are generally electrode layers coated on the piezoelectric ceramic sheet, and the coating area of ​​the electrode layer can be adjusted according to the working conditions.

[0062] Optionally, the first telescopic region 1011 and the second telescopic region 1012 of the first piezoelectric ceramic sheet 100 may have a common upper electrode or lower electrode. For example, optionally, such as Figure 4 The fifth upper electrode 309 coated on the upper surface of the first actuation region 101 of the first piezoelectric ceramic sheet 100 simultaneously covers the first telescopic region 1011 and the second telescopic region 1012. Independent first lower electrodes 302 and second lower electrodes 304 are only provided on the lower surface of the first actuation region 101 of the first piezoelectric ceramic sheet 100. This results in the first telescopic region 1011 and the second telescopic region 1012 of the first piezoelectric ceramic sheet 100 having only three electrode leads, which are driven by two driving signals to synchronously telescopically extend and retract in opposite directions. Similarly, alternatively, such as... Figure 5 As shown, the fifth lower electrode 310 coated on the lower surface of the first actuation region 101 of the first piezoelectric ceramic sheet 100 simultaneously covers the first telescopic region 1011 and the second telescopic region 1012. Only the upper surface of the first actuation region 101 of the first piezoelectric ceramic sheet 100 is provided with independent first upper electrodes 301 and second upper electrodes 303. Similarly, the first telescopic region 1011 and the second telescopic region 1012 of the first piezoelectric ceramic sheet 100 have only three electrode leads, driven by two driving signals to synchronously telescopically extend and retract in opposite directions. Further preferably, the polarization directions of the first telescopic region 1011 and the second telescopic region 1012 of the first piezoelectric ceramic sheet 100 are opposite. Since the first telescopic region 1011 and the second telescopic region 1012 telescopically extend and retract in opposite directions, thus... Figure 6 The first telescopic region 1011 and the second telescopic region 1012 of the first piezoelectric ceramic sheet 100 may share a common fifth upper electrode 309 and a fifth lower electrode 310. Specifically, the fifth upper electrode 309 coated on the upper surface of the first actuation region 101 of the first piezoelectric ceramic sheet 100 simultaneously covers both the first telescopic region 1011 and the second telescopic region 1012; similarly, the fifth lower electrode 310 coated on the lower surface of the first actuation region 101 simultaneously covers both the first telescopic region 1011 and the second telescopic region 1012. The common fifth upper electrode 309 and the fifth lower electrode 310 are each connected to an electrode lead, allowing a single drive signal to simultaneously drive the first telescopic region 1011 and the second telescopic region 1012 to telescopically extend and retract in opposite directions via the two leads.

[0063] Similarly, optionally, the second actuation region 102 of the first piezoelectric ceramic sheet 100 and the second piezoelectric ceramic sheet 200 may share a common intermediate electrode 311, which is disposed between the second actuation region 102 and the second piezoelectric ceramic sheet 200, such as... Figure 7As shown, the intermediate electrode 311 serves as both the upper electrode of the second actuation region 102 and the lower electrode of the second piezoelectric ceramic sheet. This allows the second actuation region 102 of the first piezoelectric ceramic sheet 100 and the second piezoelectric ceramic sheet 200 to have only three electrode leads, simplifying the circuitry. Two driving signals can then drive the second actuation region 102 and the second piezoelectric ceramic sheet 200 to synchronously extend and retract in opposite directions. Further preferably, the second actuation region 102 of the first piezoelectric ceramic sheet 100 and the second piezoelectric ceramic sheet 200 have the same polarization direction. Since the second actuation region 102 and the second piezoelectric ceramic sheet 200 extend and retract synchronously in opposite directions, in addition to sharing an intermediate electrode 311, the remaining two electrodes of the second actuation region 102 and the second piezoelectric ceramic sheet 200 can also share an electrode lead. This allows a single driving signal to simultaneously drive the second actuation region 102 and the second piezoelectric ceramic sheet 200 to synchronously extend and retract in opposite directions via two leads.

[0064] A second aspect of this application provides an optical fiber scanner, such as... Figure 8 As shown, it includes the aforementioned scanning actuator and optical fiber 500. The optical fiber 500 is fixedly mounted on the front end of the first piezoelectric ceramic sheet 100 in a cantilevered manner. The other end of the optical fiber 500 is connected to a light source. The optical fiber cantilever performs two-dimensional scanning under the drive of the scanning actuator. The light source emits light corresponding to the pixel point according to the scanning position of the optical fiber cantilever, thereby realizing optical fiber two-dimensional scanning imaging.

[0065] It should be noted that the above embodiments are illustrative of the invention and not restrictive, and that those skilled in the art can devise alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses should not be construed as limiting the claims. The words “comprising” or “including” do not exclude the presence of elements or steps not listed in the claims. The words “a” or “an” preceding an element do not exclude the presence of a plurality of such elements. The use of the words first, second, and third, etc., does not indicate any order and these words can be interpreted as names.

[0066] All features disclosed in this specification, except for mutually exclusive features, can be combined in any way.

[0067] Any feature disclosed in this specification (including any appended claims, abstract, and drawings) may be replaced by other equivalent or similar features, unless specifically stated otherwise. That is, unless specifically stated otherwise, each feature is merely one example of a series of equivalent or similar features.

[0068] This invention is not limited to the specific embodiments described above. The invention extends to any new feature or combination disclosed in this specification, as well as any new method or process step or combination disclosed herein.

Claims

1. A scanning actuator, characterized in that, It includes a first piezoelectric ceramic sheet and a second piezoelectric ceramic sheet, both of which are plate-shaped. With the plane where the first piezoelectric ceramic sheet is located as the horizontal plane, and the front and rear ends of the first piezoelectric ceramic sheet as the free end and fixed end of the scanning actuator, respectively; The second piezoelectric ceramic sheet is shorter in the front-to-back direction than the first piezoelectric ceramic sheet. The second piezoelectric ceramic sheet is fixedly attached to the rear side of the upper or lower surface of the first piezoelectric ceramic sheet. Driven by the first and second piezoelectric ceramic sheets, the free end of the scanning actuator performs two-dimensional scanning vibration relative to its fixed end; Both the first and second piezoelectric ceramic sheets are polarized along the thickness direction. The first piezoelectric ceramic sheet has a first actuation region located on the front side and a second actuation region located on the rear side. The second piezoelectric ceramic sheet is arranged parallel to the first piezoelectric ceramic sheet and is fixedly attached to it directly above or below the second actuation area of ​​the first piezoelectric ceramic sheet. The first telescopic area and the second telescopic area are respectively provided on the left and right sides of the first moving area. The second actuation region, the first telescopic region, the second telescopic region of the first piezoelectric ceramic sheet, and the upper and lower surfaces of the second piezoelectric ceramic sheet are all provided with upper and lower electrodes respectively. The second actuation region, the first telescopic region, the second telescopic region of the first piezoelectric ceramic sheet, and the second piezoelectric ceramic sheet all extend and retract in the front-back direction. Furthermore, the second actuation region of the first piezoelectric ceramic sheet and the second piezoelectric ceramic sheet extend and retract synchronously in opposite directions, and the first extension and retraction region and the second extension and retraction region of the first piezoelectric ceramic sheet extend and retract synchronously in opposite directions.

2. A scanning actuator as described in claim 1, characterized in that, The second actuation region, the first extension region, the second extension region of the first piezoelectric ceramic sheet, and the upper and lower surfaces of the second piezoelectric ceramic sheet are all provided with upper and lower electrodes respectively. Each upper electrode and each lower electrode is used to connect to the corresponding external driving circuit through electrode leads to drive the second actuation region, the first extension region, the second extension region, and the second piezoelectric ceramic sheet to extend and retract in the front-back direction.

3. A scanning actuator as described in claim 1 or 2, characterized in that, The first piezoelectric ceramic sheet has a first upper electrode on its upper surface and a first lower electrode on its lower surface in the first telescopic region. The second telescopic region of the first piezoelectric ceramic sheet has a second upper electrode on its upper surface and a second lower electrode on its lower surface. The second actuation region of the first piezoelectric ceramic sheet has a third upper electrode on its upper surface and a third lower electrode on its lower surface. The second piezoelectric ceramic sheet has a fourth upper electrode on its upper surface and a fourth lower electrode on its lower surface.

4. A scanning actuator as described in claim 1 or 2, characterized in that, The first and second telescopic regions of the first piezoelectric ceramic sheet have a common upper or lower electrode, which simultaneously covers both the first and second telescopic regions.

5. A scanning actuator as described in claim 4, characterized in that, The polarization directions of the first and second telescopic regions of the first piezoelectric ceramic sheet are opposite. The first and second telescopic regions of the first piezoelectric ceramic sheet have a common fifth upper electrode and a fifth lower electrode. The fifth upper electrode covers both the first and second telescopic regions. The fifth lower electrode covers both the first and second telescopic regions.

6. A scanning actuator as described in claim 1 or 2, characterized in that, The second actuation region of the first piezoelectric ceramic sheet and the second piezoelectric ceramic sheet share a common intermediate electrode. The intermediate electrode is disposed between the second actuation region and the second piezoelectric ceramic sheet. The intermediate electrode is both the upper electrode of the second actuation region and the lower electrode of the second piezoelectric ceramic sheet.

7. A scanning actuator as described in claim 6, characterized in that, The second actuation region of the first piezoelectric ceramic sheet has the same polarization direction as the second piezoelectric ceramic sheet. Except that the second actuation region and the second piezoelectric ceramic sheet share an intermediate electrode, the remaining two electrodes of the second actuation region and the second piezoelectric ceramic sheet share an electrode lead.

8. A fiber optic scanner, characterized in that, It includes a scanning actuator and an optical fiber as described in any one of claims 1-7, wherein the optical fiber is fixedly disposed at the front end of the first piezoelectric ceramic sheet in a cantilevered manner.

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