Scanning actuator and optical fiber scanner

Abstract

The present invention discloses a scanning actuator comprising a fast-axis actuator and a piezoelectric dual-chip. The fast-axis actuator comprises a first piezoelectric actuator and a second piezoelectric actuator symmetrically arranged on both sides. The first piezoelectric actuator and the second piezoelectric actuator perform synchronous and opposite expansion and contraction along the front-to-back direction. The rear ends of the piezoelectric dual-chip are fixedly connected to the first piezoelectric actuator and the second piezoelectric actuator. An optical fiber scanner using the scanning actuator is also disclosed. The fast-axis actuator of the present invention does not participate in the vibration of the slow-axis actuator, thereby greatly reducing the nonlinearity of the scanning actuator. The present invention has a simple structure, and all components are industrially mature standard devices, which greatly reduces the difficulty of the process and is suitable for mass production. The first piezoelectric actuator and the second piezoelectric actuator constitute the fixed base of the slow-axis cantilever beam and serve as the driving source for high-frequency vibration, thereby saving the length of the fast axis, making the scanner shorter, and realizing a smaller-sized scanning actuator.

Description

Technical Field

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

[0002] A fiber scanner is a display technology that uses a scanning actuator to control the swing of an optical fiber to emit a pattern. The pattern illuminated by this technology has sharp and saturated colors, high contrast, high brightness, and a very small structure. It is mainly used in fiber scanning display (FSD) technology and fiber scanning endoscope (FSE) technology.

[0003] The actuator of a grid-type fiber scanner primarily consists of a second actuator, serving as the fast axis, and a first actuator, serving as the slow axis. Both the second and first actuators have fixed and free ends, respectively, with the fixed end of the second actuator fixedly connected to the free end of the first. To achieve a stable scanning range and precisely control the scanning trajectory, the scanning trajectory of the actuator tip must be precisely aligned with the scanning trajectories of the first and second actuators. Any manufacturing error in the actuators can make the actuator's vibration difficult to control or generate random vibration components. Avoiding uncontrolled or random vibration components is a key factor in improving scanning quality.

[0004] Traditional scanner actuators are generally tubular or sheet-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 becoming irregular in shape.

[0005] For example, the scanning actuator disclosed in Chinese patent CN111830702A generally utilizes a tubular piezoelectric actuator. However, due to the aforementioned constraints, the design results in a non-uniform structure, which is quite disadvantageous for mass production of the actuator, making it difficult to manufacture and ensuring consistent manufacturing. Another example is the scanning actuator disclosed in Chinese patent CN209784655U, which generally utilizes a sheet-shaped piezoelectric actuator. Similarly, for performance reasons, the actuator is designed as a non-uniform structure, which also suffers from the aforementioned technical issues of difficulty in precise manufacturing and poor manufacturing consistency.

[0006] At the same time, existing scanners also have technical problems such as complex division of electrode areas on piezoelectric materials and complex electrode coating processing, which also increases the difficulty of processing.

[0007] Therefore, how to make the actuator easy to process and mass-produce, and achieve good mass production consistency, under the premise that each actuating part meets the performance parameters, is a technical problem that needs to be solved. Summary of the Invention

[0008] The embodiments of the present invention provide a scanning actuator and an optical fiber scanner to at least solve the technical problems of the existing scanning actuators, such as complex structure, need for electrode division, difficulty in mass production, and poor consistency in mass production.

[0009] In order to achieve the above-mentioned purpose of the invention, the first aspect of an embodiment of the present invention provides a scanning actuator, including a fast-axis actuator and a piezoelectric dual chip arranged in sequence from back to front, the fast-axis actuator including a first piezoelectric actuator and a second piezoelectric actuator symmetrically arranged on the left and right, the rear ends of the first piezoelectric actuator and the second piezoelectric actuator are fixedly connected to the base, and the first piezoelectric actuator and the second piezoelectric actuator perform synchronous and opposite expansion and contraction along the front-to-back direction; the piezoelectric dual chip is arranged parallel to the horizontal plane, and the long side of the piezoelectric dual chip extends along the front-to-back direction, and the rear ends of the piezoelectric dual chip are fixedly connected to the first piezoelectric actuator and the second piezoelectric actuator at the same time.

[0010] Thus, the synchronous, counter-directional expansion and contraction of the first and second piezoelectric actuators drives the piezoelectric bimorph to vibrate horizontally. Simultaneously, driven by the drive signal, the free end (front end) of the piezoelectric bimorph vibrates vertically relative to its fixed end (rear end). This causes the free end of the piezoelectric bimorph to vibrate both horizontally and vertically relative to the base, resulting in a motion trajectory that is a superposition of the two vibrations. The expansion and contraction frequencies of the first and second piezoelectric actuators are much greater than the vertical vibration frequency of the piezoelectric bimorph driven by the drive signal. The synchronous, counter-directional expansion and contraction of the first and second piezoelectric actuators drives the piezoelectric bimorph to vibrate horizontally, achieving row scanning in raster scanning (i.e., high-frequency, small-amplitude X-direction scanning). The vertical vibration of the piezoelectric bimorph driven by the drive signal achieves frame scanning in raster scanning (i.e., low-frequency, large-amplitude Y-direction scanning).

[0011] The fast-axis actuator composed of the first piezoelectric actuator and the second piezoelectric actuator does not participate in the vibration of the slow-axis actuator composed of the piezoelectric bimorph, thereby greatly reducing the nonlinearity of the scanning actuator.

[0012] The slow-axis cantilever beam adopts a complete dual-chip structure without a single-layer piezoelectric film structure, which greatly increases the vibration resistance of the scanner.

[0013] The present invention has a simple structure, and the first piezoelectric actuator, the second piezoelectric actuator and the piezoelectric bimorph all adopt industrially mature standard components, which greatly reduces the difficulty of the process and is suitable for mass production.

[0014] Each of the first and second piezoelectric actuators includes a piezoelectric material body and surface electrodes disposed on two opposing and parallel surfaces of the piezoelectric material body. The piezoelectric material body is polarized in a direction perpendicular to the surfaces on which the surface electrodes are disposed. Applying a forward or reverse voltage to the piezoelectric material body through the two surface electrodes causes the piezoelectric material body to extend or contract in the front-to-back direction.

[0015] Preferably, in order to reduce the driving voltage and power consumption of the first piezoelectric actuator and the second piezoelectric actuator, and to obtain the same amount of expansion and contraction at a lower driving voltage and driving power consumption, the first piezoelectric actuator and the second piezoelectric actuator adopt the following structure: the first piezoelectric actuator and the second piezoelectric actuator are both composed of a plurality of piezoelectric drive units stacked in sequence along the front-to-back direction, each piezoelectric drive unit includes a sheet-like piezoelectric material body, the front and rear end surfaces of the sheet-like piezoelectric material body are respectively provided with a front surface electrode and a rear surface electrode, the sheet-like piezoelectric material body is polarized in the front-to-back direction, and the plurality of piezoelectric drive units are stacked in sequence in the front-to-back direction and fixedly connected. The surface of the piezoelectric actuator formed by the stacked piezoelectric drive units is provided with a first electrode conductor and a second electrode conductor, one of the front surface electrode and the rear surface electrode of each piezoelectric drive unit is connected to the first electrode conductor, and the other of the front surface electrode and the rear surface electrode is connected to the second conductor.

[0016] Optionally, the lower surface of the piezoelectric dual chip is fixedly connected to the upper surface of the first piezoelectric actuator and the upper surface of the second piezoelectric actuator at the same time; of course, it can be understood that the upper surface of the piezoelectric dual chip can also be fixedly connected to the lower surface of the first piezoelectric actuator and the lower surface of the second piezoelectric actuator at the same time.

[0017] In the connection method in this embodiment, since the surfaces of the first piezoelectric actuator and the second piezoelectric actuator are fixedly connected to the piezoelectric dual chip, the piezoelectric dual chip will affect the expansion and contraction of the surfaces of the first piezoelectric actuator and the second piezoelectric actuator, thereby causing the first piezoelectric actuator and the second piezoelectric actuator to produce a vertical offset during the expansion and contraction process.

[0018] Therefore, preferably, the expansion and contraction frequencies of the first and second piezoelectric actuators are close to the horizontal natural frequencies of the piezoelectric bimorph. The horizontal resonance of the piezoelectric bimorph amplifies the horizontal swing amplitude of the piezoelectric bimorph, and the resonant swing amplitude amplification of the piezoelectric bimorph itself achieves horizontal scanning vibration of the scanning actuator. Because the horizontal resonant swing amplitude amplification of the piezoelectric bimorph is utilized to achieve horizontal scanning vibration, the expansion and contraction of the first and second piezoelectric actuators is significantly reduced, thereby minimizing the vertical offset of the first and second piezoelectric actuators during expansion and contraction, and thus negligibly affecting the vibration trajectory of the free end of the piezoelectric bimorph.

[0019] At this time, since the natural frequency of the piezoelectric dual-chip in the vertical direction is much smaller than the natural frequency of the piezoelectric dual-chip in the horizontal direction, the vertical vibration offset generated by the first piezoelectric actuator and the second piezoelectric actuator during the expansion and contraction of the above-mentioned frequency will not cause the resonance amplification of the piezoelectric dual-chip. In addition, the expansion and contraction amount of the first piezoelectric actuator and the second piezoelectric actuator as mentioned above is greatly reduced, so that its influence on the vibration trajectory of the free end of the piezoelectric dual-chip can be ignored.

[0020] The first piezoelectric actuator and the second piezoelectric actuator constitute a fixed base of the slow axis cantilever beam and serve as a driving source for high-frequency vibration, thereby saving the length of the fast axis, making the scanner shorter, and realizing a smaller-sized scanning actuator.

[0021] Optionally, the front ends of the first piezoelectric actuator and the second piezoelectric actuator are both fixedly connected to a connecting piece, and the piezoelectric bimorph is fixedly connected to the connecting piece of the first piezoelectric actuator and the connecting piece of the second piezoelectric actuator.

[0022] Optionally, the front ends of the first piezoelectric actuator and the second piezoelectric actuator are fixedly connected to the same connecting piece, that is, the connecting piece simultaneously connects the front ends of the first piezoelectric actuator and the second piezoelectric actuator, and the piezoelectric dual chip is fixedly connected to the connecting piece.

[0023] In this embodiment, the piezoelectric dual chip and the connecting parts will not interfere with the expansion and contraction of the first piezoelectric actuator and the second piezoelectric actuator, so the expansion and contraction of the first piezoelectric actuator and the second piezoelectric actuator will not generate vibration components in other directions, thereby ensuring the accuracy of the motion trajectory of the free end of the piezoelectric dual chip.

[0024] Optionally, a groove for connecting the piezoelectric dual chip is provided near the middle of the front end of the first piezoelectric actuator and the second piezoelectric actuator, and the rear end of the piezoelectric dual chip is fixedly provided in the grooves of the first piezoelectric actuator and the second piezoelectric actuator, so that the piezoelectric dual chip is fixedly connected to the first piezoelectric actuator and the second piezoelectric actuator at the same time.

[0025] Since the grooves are located near the middle of the front ends of the first piezoelectric actuator and the second piezoelectric actuator, the deformation on the upper and lower sides is symmetrical, which can minimize the possibility of the first piezoelectric actuator and the second piezoelectric actuator generating vibration components in other directions during the extension and contraction process due to the fixation of the piezoelectric dual chip, and also ensure the accuracy of the motion trajectory of the free end of the piezoelectric dual chip.

[0026] A second aspect of an embodiment of the present invention provides an optical fiber scanner, which includes the scanning actuator and an optical fiber as described above. The optical fiber is fixed to the free end (front end) of the piezoelectric bimorph in a cantilever support manner.

[0027] Specifically, the portion of the optical fiber's light-emitting end that extends beyond the free end of the piezoelectric bimorph forms a fiber cantilever, and the portion of the optical fiber located at the rear side of the fiber cantilever is fixedly connected to the scanning actuator.

[0028] One or more technical solutions in the embodiments of the present invention have at least the following technical effects or advantages:

[0029] The fast-axis actuator composed of the first piezoelectric actuator and the second piezoelectric actuator of the present invention does not participate in the vibration of the slow-axis actuator composed of the piezoelectric bimorph, thereby greatly reducing the nonlinearity of the scanning actuator.

[0030] The slow-axis cantilever beam adopts a complete dual-chip structure without a single-layer piezoelectric film structure, which greatly increases the vibration resistance of the scanner.

[0031] The present invention has a simple structure, and the first piezoelectric actuator, the second piezoelectric actuator and the piezoelectric bimorph all adopt industrially mature standard components, which greatly reduces the difficulty of the process and is suitable for mass production.

[0032] The first piezoelectric actuator and the second piezoelectric actuator constitute a fixed base of the slow axis cantilever beam and serve as a driving source for high-frequency vibration, thereby saving the length of the fast axis, making the scanner shorter, and realizing a smaller-sized scanning actuator. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 Schematic diagram of the structure of the scanning actuator of the present invention;

[0034] Figure 2 Schematic diagram of the structure of an embodiment of the piezoelectric bimorph of the present invention;

[0035] Figure 3 Schematic diagram of the structure of another embodiment of the piezoelectric bimorph of the present invention;

[0036] Figure 4 Schematic diagram of the structure of an embodiment of the fast axis actuator of the present invention;

[0037] Figure 5 is a schematic structural diagram of a second embodiment of the fast axis actuator of the present invention;

[0038] Figure 6 is a schematic structural diagram of a third embodiment of the fast axis actuator of the present invention;

[0039] Figure 7 Schematic diagram of the stacked structure of the piezoelectric drive unit of the present invention;

[0040] Figure 8 A schematic structural diagram of another connection method between the fast-axis actuator and the piezoelectric bimorph of the present invention;

[0041] Figure 9 is another structural schematic diagram of the connecting piece of the present invention;

[0042] Figure 10 Schematic diagram of the structure of the third connection method between the fast axis actuator and the piezoelectric bimorph of the present invention;

[0043] Figure 11 FIG. 4 is a schematic structural diagram of a fourth embodiment of a fast-axis actuator according to the present invention. DETAILED DESCRIPTION

[0044] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0045] Example 1:

[0046] like Figure 1 As shown, a first aspect of an embodiment of the present invention provides a scanning actuator, including a fast-axis actuator 100 and a piezoelectric dual chip 200 arranged in sequence from back to front, the fast-axis actuator 100 includes a first piezoelectric actuator 101 and a second piezoelectric actuator 102 symmetrically arranged on the left and right, the rear ends of the first piezoelectric actuator 101 and the second piezoelectric actuator 102 are fixedly connected to the base 300, and the first piezoelectric actuator 101 and the second piezoelectric actuator 102 are each driven by a driving signal to perform synchronous reverse expansion and contraction along the front-to-back direction; the piezoelectric dual chip 200 is arranged parallel to the horizontal plane, and the long side of the piezoelectric dual chip 200 extends along the front-to-back direction, and the rear ends of the piezoelectric dual chip 200 are fixedly connected to the first piezoelectric actuator 101 and the second piezoelectric actuator 102 at the same time.

[0047] Thus, the synchronous, counter-directional expansion and contraction of the first and second piezoelectric actuators 101, 102 drive the piezoelectric bimorph 200 to vibrate horizontally. Simultaneously, driven by its drive signal, the free end (front end) of the piezoelectric bimorph 200 vibrates vertically relative to its fixed end (rear end). This causes the free end of the piezoelectric bimorph 200 to vibrate both horizontally and vertically relative to the base 300. The motion trajectory of the free end of the piezoelectric bimorph 200 is a superposition of the two vibration directions. The expansion and contraction frequency of the first and second piezoelectric actuators 101, 102 is much greater than the vertical vibration frequency of the piezoelectric bimorph 200 driven by its drive signal. The synchronous, counter-directional expansion and contraction of the first and second piezoelectric actuators 101, 102 drive the piezoelectric bimorph 200 to vibrate horizontally, thereby achieving row scanning in raster scanning, i.e., high-frequency, small-amplitude X-direction scanning. The piezoelectric bimorph 200 is driven by its driving signal to vibrate in the vertical direction to achieve frame scanning in the grid scanning, that is, low-frequency and large-amplitude Y-direction scanning.

[0048] Generally, such as Figure 2 As shown, the piezoelectric bimorph 200 includes two overlapping piezoelectric ceramic sheets 201 and 202. The upper and lower surfaces of each piezoelectric ceramic sheet are coated with a conductive film to form upper and lower surface electrodes 2011, 2012, 2021, and 2022, respectively. The two piezoelectric ceramic sheets 201 and 202 are fixedly bonded together as a whole. The two piezoelectric ceramic sheets 201 and 202 are polarized along the thickness direction (i.e., the vertical direction). Alternatively, as Figure 3 As shown, a dielectric layer 203 is disposed between the two piezoelectric ceramic sheets. Both the piezoelectric bimorph 200 with and without a dielectric layer are commonly used in the art. The two piezoelectric ceramic sheets 201 and 202 expand and contract synchronously in opposite directions, causing the free end of the piezoelectric bimorph 200 to vibrate in the Y direction relative to its fixed end.

[0049] The first piezoelectric actuator 101 and the second piezoelectric actuator 102 each include a piezoelectric material body and surface electrodes disposed on two opposite and mutually parallel surfaces of the piezoelectric material body. The piezoelectric material body is polarized in a direction perpendicular to the surface on which the surface electrodes are disposed. By applying a forward voltage or a reverse voltage to the piezoelectric material body through the two surface electrodes, the piezoelectric material body is extended or contracted in the front-to-back direction. Specifically, Figure 4 As shown, the upper and lower surfaces of the piezoelectric material body 1011 of the first piezoelectric actuator 101 are respectively provided with an upper surface electrode 1012 and a lower surface electrode 1013. The piezoelectric material body 1011 of the first piezoelectric actuator 101 is polarized in the vertical direction. Figure 5As shown, the left and right surfaces of the piezoelectric material body 1011 of the first piezoelectric actuator 101 are respectively provided with a left surface electrode 1014 and a right surface electrode 1015, and the piezoelectric material body 1011 of the first piezoelectric actuator 101 is polarized in the horizontal direction. Figure 4 As shown, the upper and lower surfaces of the piezoelectric material body 1021 of the second piezoelectric actuator 102 are respectively provided with an upper surface electrode 1022 and a lower surface electrode 1023. The piezoelectric material body 1021 of the second piezoelectric actuator 102 is polarized in the vertical direction. Figure 5 As shown, the left and right surfaces of the piezoelectric material body 1021 of the second piezoelectric actuator 102 are respectively provided with a left surface electrode 1024 and a right surface electrode 1025. The piezoelectric material body 1021 of the second piezoelectric actuator 102 is polarized in the horizontal direction. It should be noted that the electrode arrangement and polarization direction of the first piezoelectric actuator 101 and the second piezoelectric actuator 102 are independent of each other and have no correlation with each other. They can be arranged in the same or different directions.

[0050] Preferably, in order to reduce the driving voltage and power consumption of the first piezoelectric actuator 101 and the second piezoelectric actuator 102 and obtain the same expansion and contraction amount at a lower driving voltage and driving power consumption, the first piezoelectric actuator 101 and the second piezoelectric actuator 102 adopt the following structure:

[0051] like Figure 6 As shown, the first piezoelectric actuator 101 and the second piezoelectric actuator 102 are both composed of a plurality of piezoelectric drive units 500 stacked in sequence along the front-to-back direction, Figure 7 As shown, each piezoelectric drive unit 50 includes a sheet-like piezoelectric material body 501, and the front and rear end surfaces of the sheet-like piezoelectric material body 501 are respectively provided with a front surface electrode 502 and a rear surface electrode 503. The sheet-like piezoelectric material body 501 is polarized along the front-to-back direction. A plurality of piezoelectric drive units are stacked in sequence and fixedly connected along the front-to-back direction. The surface of the piezoelectric actuator formed by the stacked piezoelectric drive units is provided with a first electrode conductive member 510 and a second electrode conductive member 511. One of the front surface electrode and the rear surface electrode of each piezoelectric drive unit is connected to the first electrode conductive member, and the other of the front surface electrode and the rear surface electrode is connected to the second conductive member. Which electrode is connected to which electrode conductive member is matched and connected according to the polarization direction of the piezoelectric drive unit, which is common sense for those skilled in the art.

[0052] Further preferably, any two adjacent piezoelectric drive units may share a surface electrode located between the two piezoelectric drive units, and in this case, the polarization directions of the sheet-like piezoelectric material bodies of the two piezoelectric drive units are opposite. Figure 7As shown, the polarization directions of the sheet-like piezoelectric material bodies 506 and 507 of two adjacent piezoelectric drive units are opposite, and the two piezoelectric drive units share a surface electrode 504; at the same time, the polarization directions of the sheet-like piezoelectric material bodies 508 and 507 of two adjacent piezoelectric drive units are opposite, and the two piezoelectric drive units share a surface electrode 505.

[0053] In actual production, to facilitate manufacturing, the first piezoelectric actuator 101 and the second piezoelectric actuator 102 can be bonded together using a low-modulus glue. Alternatively, a single block of piezoelectric material can be cut through the middle to separate the piezoelectric material into the piezoelectric material body of the second piezoelectric actuator 102 and the piezoelectric material body of the second piezoelectric actuator 102. The rear ends of the first and second piezoelectric actuators 101, 102 are fixed to the base 300, which can be part of a housing used to encapsulate the scanning actuator.

[0054] The present invention enables the first piezoelectric actuator 101 and the second piezoelectric actuator 102 to form a fixed base of the slow axis cantilever beam and serve as a driving source for high-frequency vibration, thereby saving the length of the fast axis, making the scanner shorter, and realizing a smaller-sized scanning actuator.

[0055] The fast-axis actuator formed by the first piezoelectric actuator 101 and the second piezoelectric actuator 102 does not participate in the vibration of the slow-axis actuator formed by the piezoelectric bimorph 200 , thereby greatly reducing the nonlinearity of the scanning actuator.

[0056] The slow-axis cantilever beam adopts a complete dual-chip structure without a single-layer piezoelectric film structure, which greatly increases the vibration resistance of the scanner.

[0057] The structure of the present invention is simple. The first piezoelectric actuator 101, the second piezoelectric actuator 102 and the piezoelectric bimorph 200 all adopt industrially mature standard components, which greatly reduces the process difficulty and is suitable for mass production.

[0058] Example 2:

[0059] Based on Example 1, Example 2 provides a connection method between the fast-axis actuator and the piezoelectric bimorph 200 .

[0060] The other configurations in this embodiment are the same as those in embodiment 1. Based on embodiment 1, in this embodiment, Figure 1 As shown, the lower surface of the piezoelectric dual chip 200 is fixedly connected to the upper surface of the first piezoelectric actuator 101 and the upper surface of the second piezoelectric actuator 102 at the same time; of course, it can be understood that the upper surface of the piezoelectric dual chip 200 can also be fixedly connected to the lower surface of the first piezoelectric actuator 101 and the lower surface of the second piezoelectric actuator 102 at the same time.

[0061] In the connection method in this embodiment, since the surfaces of the first piezoelectric actuator 101 and the second piezoelectric actuator 102 are fixedly connected to the piezoelectric dual chip 200, the piezoelectric dual chip 200 will affect the expansion and contraction of the surfaces of the first piezoelectric actuator 101 and the second piezoelectric actuator 102, thereby causing the first piezoelectric actuator 101 and the second piezoelectric actuator 102 to have a vertical offset during the expansion and contraction process.

[0062] Therefore, preferably, the expansion and contraction frequencies of the first and second piezoelectric actuators 101, 102 are close to the horizontal natural frequency of the piezoelectric bimorph 200. The horizontal resonance of the piezoelectric bimorph 200 amplifies the horizontal swing amplitude of the piezoelectric bimorph 200, and the resonant swing amplitude amplification of the piezoelectric bimorph 200 itself achieves horizontal scanning vibration of the scanning actuator. Because the horizontal resonant swing amplitude amplification of the piezoelectric bimorph 200 is utilized to achieve horizontal scanning vibration, the expansion and contraction of the first and second piezoelectric actuators 101, 102 is significantly reduced, thereby minimizing the vertical offset of the first and second piezoelectric actuators 101, 102 during expansion and contraction, and thus negligible the impact on the vibration trajectory of the free end of the piezoelectric bimorph 200.

[0063] At this time, since the natural frequency of the piezoelectric dual-chip 200 in the vertical direction is much smaller than the natural frequency of the piezoelectric dual-chip 200 in the horizontal direction, the vertical vibration offset generated by the first piezoelectric actuator 101 and the second piezoelectric actuator 102 during the expansion and contraction process of the above-mentioned frequency will not cause the resonance amplification of the piezoelectric dual-chip 200. In addition, the expansion and contraction amount of the first piezoelectric actuator 101 and the second piezoelectric actuator 102 as described above is greatly reduced, so that its influence on the vibration trajectory of the free end of the piezoelectric dual-chip 200 can be ignored.

[0064] Example 3:

[0065] Based on Example 1, Example 3 provides a connection method between the fast-axis actuator and the piezoelectric bimorph 200 .

[0066] The other configurations in this embodiment are the same as those in embodiment 1. Based on embodiment 1, in this embodiment, Figure 8 As shown, the front ends of the first piezoelectric actuator 101 and the second piezoelectric actuator 102 are fixedly connected to a connecting piece 103, 104, and the piezoelectric dual chip 200 is fixedly connected to the connecting piece 103 of the first piezoelectric actuator 101 and the connecting piece 104 of the second piezoelectric actuator 102 at the same time.

[0067] Also optional, such as Figure 9As shown, the front ends of the first piezoelectric actuator 101 and the second piezoelectric actuator 102 are fixedly connected to the same connecting member 105, that is, the connecting member 105 simultaneously connects the front ends of the first piezoelectric actuator 101 and the second piezoelectric actuator 102, and the piezoelectric dual chip 200 is fixedly connected to the connecting member 105.

[0068] In this embodiment, the piezoelectric dual chip 200 and the connecting part 105 will not interfere with the expansion and contraction of the first piezoelectric actuator 101 and the second piezoelectric actuator 102. Therefore, the expansion and contraction of the first piezoelectric actuator 101 and the second piezoelectric actuator 102 will not generate vibration components in other directions, thereby ensuring the accuracy of the motion trajectory of the free end of the piezoelectric dual chip 200.

[0069] Example 4:

[0070] Based on Example 1, Example 4 provides a connection method between the fast-axis actuator and the piezoelectric bimorph 200 .

[0071] The other configurations in this embodiment are the same as those in embodiment 1. Based on embodiment 1, in this embodiment, Figure 10 、 Figure 11 As shown, a groove 106, 107 for connecting to the piezoelectric dual chip 200 is provided near the middle of the front end of the first piezoelectric actuator 101 and the second piezoelectric actuator 102, and the rear end of the piezoelectric dual chip 200 is fixedly provided in the grooves 106, 107 of the first piezoelectric actuator 101 and the second piezoelectric actuator 102 at the same time, so that the piezoelectric dual chip 200 is fixedly connected to the first piezoelectric actuator 101 and the second piezoelectric actuator 102 at the same time.

[0072] Since the grooves 106 and 107 are both located near the middle of the front ends of the first piezoelectric actuator 101 and the second piezoelectric actuator 102, the deformation on the upper and lower sides is symmetrical, thereby minimizing the risk of the first piezoelectric actuator 101 and the second piezoelectric actuator 102 generating vibration components in other directions during the extension and contraction process due to the fixation of the piezoelectric dual chip 200, and also ensuring the accuracy of the motion trajectory of the free end of the piezoelectric dual chip 200.

[0073] Example 5:

[0074] This embodiment provides a fiber optic scanner, such as Figure 1 、 Figure 8 、 Figure 10 As shown, it includes a scanning actuator and an optical fiber 400 as described in any one of embodiments 1-5, and the optical fiber 400 is fixed to the free end (front end) of the piezoelectric dual chip 200 in a cantilever support manner.

[0075] Specifically, the portion of the optical fiber 400's light-emitting end that extends beyond the free end of the piezoelectric bimorph 200 forms a fiber cantilever 401. The portion of the optical fiber located at the rear of the fiber cantilever is fixedly connected to a scanning actuator. The other end of the optical fiber 400 is connected to a light source. Driven by the scanning actuator, the fiber cantilever performs two-dimensional scanning. The light source emits light corresponding to the pixel point at the scanning position of the fiber cantilever, thus achieving two-dimensional fiber scanning imaging.

[0076] The optical fiber can be arranged on the surface of the piezoelectric bimorph 200, such as Figure 10 As shown, it can also be set inside the piezoelectric bimorph 200, such as Figure 1 、 Figure 8 As shown, there is no limitation on this.

[0077] It should be noted that the above embodiments illustrate rather than limit the present invention, 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 symbols placed between brackets should not be construed as limiting the claims. The words "comprise" or "include" do not exclude the presence of elements or steps not listed in the claims. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The use of the words first, second, and third, etc. does not indicate any order and these words may be interpreted as names.

[0078] All features disclosed in this specification, except mutually exclusive features, can be combined in any way.

[0079] Any feature disclosed in this specification (including any appended claims, abstract and drawings), unless otherwise stated, may be replaced by other equivalent or similar features. That is, unless otherwise stated, each feature is only an example of a series of equivalent or similar features.

[0080] The present invention is not limited to the aforementioned 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 fast-axis actuator comprises a fast-axis actuator and a piezoelectric bimorph sequentially arranged in a back-to-front direction. The fast-axis actuator comprises a first piezoelectric actuator and a second piezoelectric actuator symmetrically arranged on both sides. The rear ends of the first and second piezoelectric actuators are fixedly connected to the base. The first and second piezoelectric actuators are synchronously extended and retracted in opposite directions in the front-to-back direction. The piezoelectric bimorph is arranged parallel to the horizontal plane, and the long side of the piezoelectric bimorph extends in the front-to-back direction, and the rear end of the piezoelectric bimorph is fixedly connected to the first piezoelectric actuator and the second piezoelectric actuator at the same time; The piezoelectric dual chip is driven to vibrate in the horizontal direction by the synchronous opposite expansion and contraction of the first piezoelectric actuator and the second piezoelectric actuator. At the same time, the free end of the piezoelectric dual chip is driven to vibrate in the vertical direction relative to the fixed end by its driving signal.

2. A scanning actuator according to claim 1, characterized in that: The first piezoelectric actuator and the second piezoelectric actuator both include a piezoelectric material body and surface electrodes arranged on two opposite and mutually parallel surfaces of the piezoelectric material body. The piezoelectric material body is polarized in a direction perpendicular to the surface where the surface electrodes are arranged.

3. A scanning actuator according to claim 1, characterized in that: The first piezoelectric actuator and the second piezoelectric actuator are both composed of a plurality of piezoelectric drive units stacked in sequence along the front-to-back direction, each piezoelectric drive unit includes a sheet-like piezoelectric material body, and the front and rear end faces of the sheet-like piezoelectric material body are respectively provided with a front surface electrode and a rear surface electrode, the sheet-like piezoelectric material body is polarized in the front-to-back direction, and the plurality of piezoelectric drive units are stacked in sequence along the front-to-back direction and fixedly connected.

4. A scanning actuator according to any one of claims 1 to 3, characterized in that: The lower surface of the piezoelectric bimorph is fixedly connected to the upper surface of the first piezoelectric actuator and the upper surface of the second piezoelectric actuator; Or the upper surface of the piezoelectric bimorph is fixedly connected to the lower surface of the first piezoelectric actuator and the lower surface of the second piezoelectric actuator at the same time.

5. A scanning actuator according to claim 4, characterized in that: The expansion and contraction frequencies of the first piezoelectric actuator and the second piezoelectric actuator are close to the natural frequencies of the piezoelectric dual-chip in the horizontal direction. The swing amplitude of the piezoelectric dual-chip in the horizontal direction is amplified by the resonance of the piezoelectric dual-chip in the horizontal direction, and the scanning vibration of the scanning actuator in the horizontal direction is realized by the resonance swing amplification of the piezoelectric dual-chip itself.

6. A scanning actuator according to any one of claims 1 to 3, characterized in that: The front ends of the first piezoelectric actuator and the second piezoelectric actuator are both fixedly connected to a connecting piece, and the piezoelectric bimorph is fixedly connected to the connecting piece of the first piezoelectric actuator and the connecting piece of the second piezoelectric actuator at the same time.

7. A scanning actuator according to any one of claims 1 to 3, characterized in that: The front end of the first piezoelectric actuator and the front end of the second piezoelectric actuator are fixedly connected to the same connecting piece, that is, the connecting piece simultaneously connects the front end of the first piezoelectric actuator and the front end of the second piezoelectric actuator, and the piezoelectric dual chip is fixedly connected to the connecting piece.

8. A scanning actuator according to any one of claims 1 to 3, characterized in that: A groove for connecting the piezoelectric dual chip is provided near the middle of the front end of the first piezoelectric actuator and the second piezoelectric actuator, and the rear end of the piezoelectric dual chip is fixedly provided in the groove of the first piezoelectric actuator and the second piezoelectric actuator.

9. A fiber optic scanner, characterized in that: The device comprises a scanning actuator as claimed in any one of claims 1 to 8 and an optical fiber, wherein the optical fiber is fixed to the free end of the piezoelectric bimorph in a cantilever support manner.

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