Optical fiber scanner capable of preventing slow axis from influencing response characteristic of fast axis

Abstract

The invention discloses an optical fiber scanner capable of preventing a slow axis from influencing the response characteristic of a fast axis, the optical fiber scanner comprises a scanning driver and an optical fiber, the scanning driver is fixedly connected with a base body through a supporting piece, and the scanning driver comprises a fast axis driving part, a rigid connecting piece and a slow axis driving part which are sequentially arranged from back to front; the fast axis driving part comprises a first piezoelectric block actuating part and a second piezoelectric block actuating part which are arranged in a bilateral symmetry mode, the fast axis driving part drives the scanning driver to vibrate at high frequency so as to achieve line scanning, and the frequency of the high-frequency vibration serves as the working frequency. The supporting piece is connected with the rigid connecting piece and arranged at a vibration node when the scanning driver vibrates in the left-right direction under the working frequency. The actuating part of the fast shaft is not influenced by the counter-acting force of the bending of the slow shaft, so that the accuracy of a scanning track is ensured; the support member does not interfere with the vibration of the fast-axis driving part or the slow-axis driving part, and enables the sensitivity of the scanning driver to the resonant frequency to be low.

Description

Technical Field

[0001] The present invention relates to the technical field of fiber optic scanning display, and in particular to a fiber optic scanner that avoids the influence of the slow axis on the response characteristics of the fast axis. Background Art

[0002] A fiber optic scanner is a display technology that uses a scanning driver to control the swing of an optical fiber while the optical fiber emits light. It is mainly used in fiber optic scanning display (FSD) technology and fiber optic scanning endoscope (FSE) technology. When the fiber optic scanner is applied to image display, the patterns irradiated by this technology have sharp and saturated colors, high contrast, high brightness, and a very small structural volume.

[0003] The fiber optic scanner uses the principle of mechanical resonance to enable the fiber cantilever to achieve a large scanning range. The scanning methods of the scanning driver can be divided into spiral scanning type, grid scanning type, and Lissajous scanning type. Miniature piezoelectric scanning devices using spiral scanning and Lissajous scanning usually have a symmetric structure, small volume, and fast scanning speed. However, the spiral scanning density is uneven, and the resonance frequencies of the two axes are the same. Therefore, there is mechanical coupling, which will deteriorate the scanning trajectory and is difficult to completely eliminate through post-processing; using grid scanning requires a large difference in the scanning frequencies of the two axes. One axis has a fast scanning frequency to achieve line scanning, and the other axis has a slow scanning frequency to achieve frame scanning. The fast axis uses fiber resonance to achieve amplification.

[0004] Traditional grid scanning drivers generally include a slow axis actuating part and a fast axis actuating part connected in sequence. The vibration coupling and mutual interference between the two actuating parts will cause uncontrolled components in the scanning trajectory, resulting in distortion of the scanned image. Summary of the Invention

[0005] The inventors found in their research that:

[0006] When the slow axis actuating part of the scanning driver bends, its high-frequency vibration response to the fast axis actuating part will change slightly, and this slight change will cause the overall high-frequency response characteristics of the scanning actuator to change slightly. Specifically, under the action of the reaction force of the slow axis actuator's vibration, the high-frequency vibration response characteristics of the fast axis actuator will also change slightly. Since the fast axis direction needs to use fiber resonance to amplify the swing amplitude, the working frequency of the fast axis needs to be near the resonance frequency, and the nonlinear vibration characteristics of an object are obvious near the resonance frequency. A weak perturbation will significantly affect its vibration response. Especially for a scanning driver in which the fast axis actuator is arranged at the rear end of the slow axis actuator and the fiber cantilever is arranged at the front end of the slow axis actuator, compared with a scanning driver in which the fast axis actuator is arranged at the front end of the slow axis actuator and the fiber cantilever is arranged at the front end of the fast axis brake, it can solve the problems of limited volume, mass, and small driving ability of the fast axis actuator. However, the vibration reaction force of the slow axis actuator directly acts on the fast axis actuator, and the stress causes the response characteristics of the fast axis actuator to change.

[0007] Therefore, on the basis above, an embodiment of the present invention provides an optical fiber scanner that avoids the slow axis from affecting the response characteristics of the fast axis, so as to at least overcome the technical problem that the vibration of the slow axis actuator reacts on the fast axis actuator, resulting in a change in its response characteristics.

[0008] To achieve the above-mentioned invention purpose, the present invention provides an optical fiber scanner that avoids the slow axis from affecting the response characteristics of the fast axis, including a scanning driver and an optical fiber. The scanning driver is fixedly connected to a base through a support member.

[0009] The scanning driver includes a fast axis driving part, a rigid connection member, and a slow axis driving part that are arranged in sequence from back to front.

[0010] The fast axis driving part includes a first piezoelectric block actuating part and a second piezoelectric block actuating part that are symmetrically arranged left and right. Both the first piezoelectric block actuating part and the second piezoelectric block actuating part expand and contract in the front-back direction under the drive of a drive signal, and the first piezoelectric block actuating part and the second piezoelectric block actuating part expand and contract synchronously and in opposite directions. The rear end of the rigid connection member is simultaneously connected to the first piezoelectric block actuating part and the second piezoelectric block actuating part.

[0011] Thus, the synchronous and opposite expansion and contraction of the first piezoelectric block actuating part and the second piezoelectric block actuating part drive the scanning driver to vibrate left and right at a high frequency in the horizontal direction to achieve line scanning. At the same time, under the drive of its drive signal, the front end of the slow axis driving part vibrates in the vertical direction relative to its rear end to drive the scanning driver to vibrate at a low frequency in the vertical direction to achieve frame scanning.

[0012] Taking the front end of the scanning driver as the first free end and the rear end of the scanning driver as the second free end, the optical fiber is fixedly arranged at the first free end of the scanning driver in a cantilever support manner, and the part of the optical fiber extending beyond the first free end of the scanning driver forms an optical fiber cantilever.

[0013] The optical fiber cantilever vibrates in both the left-right direction and the vertical direction under the drive of the scanning driver to achieve two-dimensional scanning.

[0014] Taking the frequency of the high-frequency vibration as the operating frequency, the support member is arranged at the vibration node when the scanning driver vibrates in the left-right direction at the operating frequency, and the connection position between the scanning driver and the support member is located at the rigid connection member.

[0015] The base includes a housing for encapsulating the optical fiber scanner or a base for mounting the optical fiber scanner.

[0016] The slow axis driving part can be any one of a piezoelectric ceramic actuator, a magnetostrictive actuator, and a microelectromechanical brake, and there is no requirement for this.

[0017] As a preferred embodiment, the slow-axis driving part is a piezoelectric sheet actuator. The piezoelectric sheet actuator is parallel to the horizontal plane, so that the natural frequency of the slow-axis driving part in the horizontal left-right direction can be significantly different from the natural frequency of the slow-axis driving part. Thus, when the slow-axis driving part vibrates in the vertical direction under the drive of a driving signal, no response vibration will occur in other directions, ensuring the accuracy of the slow-axis movement trajectory.

[0018] By providing a rigid connecting member, a support member connected to the rigid connecting member and the connection point being located at the vibration node of the scanning driver at the operating frequency, and the fast-axis driving part being arranged behind the rigid connecting member, the deformation stress generated by the vibration of the slow-axis driving part can directly act on the rigid connecting member. The rigid connecting member will not transmit the deformation stress generated by the vibration of the slow-axis driving part to the fast-axis actuating part, so that the fast-axis actuating part will not be affected by the reaction force of the slow-axis bending. Furthermore, the response characteristics of the fast-axis actuating part will not change, ensuring the accuracy of the scanning trajectory; the support member does not contact the fast-axis driving part or the slow-axis driving part and will not interfere with the vibration of the fast-axis driving part or the slow-axis driving part, also ensuring the accuracy of the scanning trajectory; the support member is arranged at the vibration node of the scanning driver at the operating frequency, making the scanning driver less sensitive to the resonance frequency, which helps to further improve the stability and scanning accuracy of the system, effectively reducing the non-linear problems of the scanning display grid, such as grid line bending, opening, etc., thereby improving the display quality.

[0019] Although the present invention provides a rigid connecting member and a support member, it does not increase the complexity of the system. Instead, by optimizing the existing design, without increasing the complexity and negative impact of the system, it effectively reduces the influence of the reaction force of the vibration of the slow-axis driving part on the response characteristics of the fast-axis driving part.

[0020] The structure with the fast-axis driving part for fast-axis driving arranged at the rear allows the fast axis to have a larger volume and mass, ensuring that the high-frequency actuating part has sufficient driving force. The first piezoelectric block actuating part and the second piezoelectric block actuating part have a larger mass per unit length in the front-rear direction, which makes the vibration node closest to the second free end of the scanning driver at the operating frequency closer to the second free end of the scanning driver, facilitating the reduction of the length of the scanning driver in the front-rear direction. At the same time, it also enables the scanning driver to have a wider operating frequency range and can operate normally within a large range.

[0021] By adjusting the physical parameters (such as volume, shape, mass, density, etc.) of the fast-axis driving part, the rigid connecting part, and / or the slow-axis driving part, the connection position of the support part is located at the rigid connecting part, avoiding the interference of the support structure on the vibration of the fast-axis driving part or the slow-axis driving part. At the same time, the support part is located at the node position of high-frequency vibration. Since the displacement at the node position during the vibration process is very small, the influence of the support part on the vibration of the scanning driver is further reduced. Through experimental comparison, when using the fiber optic scanner of the present invention and changing the clamping conditions (such as clamping force, clamping part material, base material, etc.), the characteristic frequencies of the required modes for the operation of the fiber optic scanner will not change, and the image display can be accurately and consistently performed, and the scanning trajectory will not change. The versatility of the fiber optic scanner is improved, and the requirements for installation accuracy and the consistency of installation conditions are reduced, and the installation difficulty is reduced.

[0022] Specifically, the operating frequency is near a certain natural frequency when the fiber optic cantilever vibrates in the second direction, and the operating frequency is also near a certain natural frequency when the scanning driver vibrates in the second direction (since the mass of the fiber optic is small, the vibration characteristics of the system composed of the fiber optic and the scanning driver can be equivalently regarded as the vibration characteristics of the scanning driver).

[0023] The above-mentioned operating frequency is near a certain natural frequency when the fiber optic cantilever vibrates in the second direction, and the operating frequency is also near a certain natural frequency when the scanning driver vibrates in the second direction, which means that there is a difference between the operating frequency and a certain natural frequency when the fiber optic cantilever vibrates in the second direction, such as a difference of dozens to thousands of Hz. In the actual operation process, this difference is determined with the goal of enabling the fiber optic cantilever to obtain a large resonance swing while reducing non-linear vibration. At the same time, there is a difference between the operating frequency and a certain natural frequency when the scanning driver vibrates in the second direction, such as a difference of dozens to thousands of Hz. In the actual operation process, this difference is determined with the goal of enabling the scanning driver to obtain a large resonance swing while reducing non-linear vibration.

[0024] Preferably, the operating frequency is near the first natural frequency when the fiber optic cantilever vibrates in the second direction or near a higher-order natural frequency when the fiber optic cantilever vibrates in the second direction. At the same time, the operating frequency is also near the second natural frequency when the scanning driver vibrates in the second direction or near a higher-order natural frequency when the scanning driver vibrates in the second direction.

[0025] In order to reduce the overall length of the scanning driver, preferably, the support part is located at the vibration node when the scanning driver vibrates in the second direction at the operating frequency, and at the vibration node closest to the second free end and located at the rigid connecting part.

[0026] In order to further reduce the length of the tail cantilever, preferably, the mass per unit front-back length of the part of the scanning driver close to the second free end is greater than the mass per unit front-back length of the rest of the scanning driver, so that the position of the vibration node closest to the second free end of the scanning driver at the operating frequency is closer to the second free end, thereby achieving the purpose of reducing the length of the tail cantilever.

[0027] Further preferably, the vibration node of the rigid connecting member closest to the second free end is located at the rearmost end of the rigid connecting member, that is, the end of the rigid connecting member connecting the second actuator.

[0028] On this basis, it is also possible to make the connection between the support member and the scanning actuator coincide with or be close to the vibration node when the scanning actuator vibrates in the first direction at the low-frequency driving frequency for frame scanning. In this way, the influence of the support member on the characteristic frequency of the mode required for the operation of the scanning actuator can be minimized.

[0029] As a preferred embodiment, the support member only provides support for the scanning driver without restricting the vibration of the scanning driver, and the support member does not affect the normal transmission of mechanical waves in the scanning driver. Thereby, the influence of the support member on the working state of the scanning driver can be reduced. Specifically, the support member can be made of a material with a certain elastic deformation ability, or the contact area between the support member and the scanning driver can be minimized as much as possible. For example, the support member can be a support rod, which extends in the vertical direction and is arranged at the central position of the scanning driver in the left-right direction, which is one of the positions with the smallest deformation amount when the scanning driver vibrates in the left-right direction at the operating frequency. Another example is that the support member is a support thin plate arranged at the vibration node when the scanning driver vibrates in the first direction at the operating frequency, so as to minimize the contact area between the support member and the scanning driver.

[0030] One or more technical solutions in the embodiments of the present invention have at least the following technical effects or advantages:

[0031] By providing a rigid connecting member in the present invention, the deformation stress generated by the vibration of the slow-axis driving part can directly act on the rigid connecting member, and the rigid connecting member will not transfer the deformation stress generated by the vibration of the slow-axis driving part to the fast-axis actuator part, so that the fast-axis actuator part will not be affected by the reaction force of the slow-axis bending, and further the response characteristics of the fast-axis actuator part will not change, ensuring the accuracy of the scanning trajectory; the support member does not contact the fast-axis driving part or the slow-axis driving part, and will not interfere with the vibration of the fast-axis driving part or the slow-axis driving part, also ensuring the accuracy of the scanning trajectory; the support member is arranged at the vibration node of the scanning driver at the operating frequency, so that the scanning driver has a lower sensitivity to the resonance frequency, which helps to further improve the stability and scanning accuracy of the system. Description of the Drawings

[0032] Figure 1 is a schematic structural diagram of the present invention;

[0033] Figure 2 is a schematic structural diagram of the scanning driver. Specific Embodiments

[0034] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0035] As Figure 1 、 Figure 2 shown, an embodiment of the present invention provides an optical fiber scanner that avoids the influence of the slow axis on the fast axis response characteristics, including a scanning driver 100 and an optical fiber 200. The scanning driver 100 is fixedly connected to the base body 400 through a support member 300.

[0036] The scanning driver 100 includes a fast axis driving portion 110, a rigid connecting member 130, and a slow axis driving portion 120 that are sequentially arranged from back to front.

[0037] The fast axis driving portion 110 includes a first piezoelectric block actuating portion 111 and a second piezoelectric block actuating portion 112 that are symmetrically arranged left and right. Both the first piezoelectric block actuating portion 111 and the second piezoelectric block actuating portion 112 expand and contract in the front-rear direction under the drive of a drive signal, and the first piezoelectric block actuating portion 111 and the second piezoelectric block actuating portion 112 expand and contract synchronously and in opposite directions. The rear end of the rigid connecting member 130 is connected to both the first piezoelectric block actuating portion 111 and the second piezoelectric block actuating portion 112 at the same time.

[0038] Thus, the synchronous and opposite expansion and contraction of the first piezoelectric block actuating portion 111 and the second piezoelectric block actuating portion 112 drive the scanning driver 100 to vibrate left and right at a high frequency in the horizontal direction to achieve line scanning. At the same time, under the drive of its drive signal, the front end of the slow axis driving portion 120 vibrates in the vertical direction relative to its rear end to drive the scanning driver 100 to vibrate in the vertical direction at a low frequency to achieve frame scanning.

[0039] Taking the front end of the scanning driver 100 as the first free end 101 and the rear end of the scanning driver 100 as the second free end 102, the optical fiber 200 is fixedly arranged at the first free end 101 of the scanning driver 100 in a cantilever support manner. The part of the optical fiber 200 that extends beyond the first free end 101 of the scanning driver 100 forms an optical fiber cantilever 201.

[0040] The fiber optic cantilever vibrates simultaneously in the left - right direction and the vertical direction under the drive of the scanning driver to achieve two - dimensional scanning;

[0041] Taking the frequency of high - frequency vibration as the operating frequency, the support member is arranged at the vibration node when the scanning driver vibrates in the left - right direction at the operating frequency, and the connection position between the scanning driver and the support member is located at the rigid connecting member 130.

[0042] The base body 400 includes a housing for encapsulating the fiber optic scanner or a base for mounting the fiber optic scanner.

[0043] The slow - axis driving part 120 can be any one of a piezoelectric ceramic actuator, a magnetostrictive actuator, and a micro - electromechanical brake, and there is no requirement for this.

[0044] As a preferred embodiment, the slow - axis driving part 120 is a piezoelectric sheet actuator. The piezoelectric sheet actuator is parallel to the horizontal plane, so that the natural frequency of the slow - axis driving part 120 in the horizontal left - right direction can be significantly different from the natural frequency of the slow - axis driving part 120, so as to ensure that when the slow - axis driving part 120 vibrates in the vertical direction at a low frequency under the drive of a driving signal, it will not generate response vibration in other directions, ensuring the accuracy of the slow - axis movement trajectory.

[0045] In the present invention, by setting the rigid connecting member 130, the support member is connected to the rigid connecting member 130 and the connection position is at the vibration node of the scanning driver at the operating frequency, and the fast - axis driving part is arranged at the rear side of the rigid connecting member 130, the deformation stress generated by the vibration of the slow - axis driving part can directly act on the rigid connecting member 130. The rigid connecting member 130 will not transfer the deformation stress generated by the vibration of the slow - axis driving part to the fast - axis actuating part, so that the fast - axis actuating part will not be affected by the reaction force of the slow - axis bending, and further the response characteristics of the fast - axis actuating part will not change, ensuring the accuracy of the scanning trajectory; the support member does not contact the fast - axis driving part or the slow - axis driving part and will not interfere with the vibration of the fast - axis driving part or the slow - axis driving part, also ensuring the accuracy of the scanning trajectory; the support member is arranged at the vibration node of the scanning driver at the operating frequency, making the scanning driver less sensitive to the resonant frequency, which helps to further improve the stability and scanning accuracy of the system, effectively reducing the non - linear problems of the scanning display grid, such as grid line bending, opening and other phenomena, thus improving the display quality.

[0046] Although the present invention sets the rigid connecting member 130 and the support member, it does not increase the complexity of the system. Instead, by optimizing the existing design, without increasing the system complexity and negative impacts, it effectively reduces the influence of the reaction force of the slow - axis driving part vibration on the response characteristics of the fast - axis driving part.

[0047] A structure with the fast-axis driving part located at the rear for fast-axis driving allows the fast axis to have a larger volume and mass, ensuring that the high-frequency actuation part has sufficient driving force. The first piezoelectric block actuator 111 and the second piezoelectric block actuator 112 have a larger mass per unit length in the front-rear direction. This makes the vibration node closest to the second free end 102 of the scanning driver 100 at the operating frequency closer to the second free end 102 of the scanning driver 100, which is beneficial for reducing the length of the scanning driver in the front-rear direction. At the same time, it also enables the scanning driver to have a relatively wide operating frequency range and can operate normally within a large range.

[0048] By adjusting the physical parameters (such as volume, shape, mass, density, etc.) of the fast-axis driving part, the rigid connecting member 130, and / or the slow-axis driving part, the connection position of the support member is located at the rigid connecting member 130, avoiding the interference of the support structure on the vibration of the fast-axis driving part or the slow-axis driving part. At the same time, the support member is located at the node position of high-frequency vibration. Since the displacement at the node position is very small during the vibration process, the influence of the support member on the vibration of the scanning driver is further reduced. Through experimental comparison, when using the fiber optic scanner of the present invention and changing the clamping conditions (such as clamping force, material of the clamping member, material of the base, etc.), the characteristic frequencies of the required modes for the operation of the fiber optic scanner will not change, and the image display can be accurately and consistently performed, and the scanning trajectory will not change. This improves the versatility of the fiber optic scanner, reduces the requirements for installation accuracy and the consistency of installation conditions, and reduces the installation difficulty.

[0049] The vibration mode of the scanning driver 100 refers to the macroscopic structural form reflected by the different vibration or displacement states of each part of the system at a certain moment. The displacement directions and magnitudes at different positions on the vibration mode change continuously. Among them, some spatial structural positions where the displacement is always 0 or the smallest become "fixed points" or "nodes". The nodes reflect the main modes that affect the vibration of the system at this frequency. The mode represents a certain order of resonance form. Mathematically, the mode refers to the eigenvalue of the system's characteristic equation, and the vibration mode is the eigenvector.

[0050] Taking the transverse bending vibration of a cantilever beam as an example, among the various resonance modes of the transverse bending vibration of the cantilever beam, the intersection with the horizontal axis means that the displacement at this point is always 0, that is, a fixed point or a node. The first-order vibration mode has one node. Correspondingly, the second-order vibration mode has 2 nodes, the third-order vibration mode has 3 nodes, and so on.

[0051] Specifically, the operating frequency is near a certain natural frequency when the fiber optic cantilever 201 vibrates in the second direction, and the operating frequency is also near a certain natural frequency when the scanning driver 100 vibrates in the second direction (since the mass of the fiber optic is small, the vibration characteristics of the system composed of the fiber optic and the scanning driver can be equivalently considered as the vibration characteristics of the scanning driver).

[0052] The scanning driver 100, the fiber optic cantilever 201, and the scanner system composed of the scanning driver 100 and the optical fiber 200 all have natural frequencies based on one or more properties. Generally, the natural frequency is an inherent frequency characteristic of the device. In some examples, the natural frequency and the resonant frequency (or resonance frequency) are equivalent. The one or more properties include, but are not limited to: material, Young's modulus, second moment of area, density, cross-sectional area, length, and / or mode constant, etc.

[0053] The natural frequency of the device is not just a single frequency point, but has a series of multiple frequency points distributed according to a certain rule, that is, there are multiple orders.

[0054] The above working frequency is near a certain order natural frequency when the fiber optic cantilever 201 vibrates in the second direction, and the working frequency is also near a certain order natural frequency when the scanning driver 100 vibrates in the second direction, which means there is a difference between the working frequency and a certain order natural frequency when the fiber optic cantilever 201 vibrates in the second direction, such as a difference of dozens to thousands of Hz. In the actual operation process, this difference is determined with the goal of enabling the fiber optic cantilever to obtain a large resonance swing amplitude while reducing non-linear vibration. At the same time, there is a difference between the working frequency and a certain order natural frequency when the scanning driver 100 vibrates in the second direction, such as a difference of dozens to thousands of Hz. In the actual operation process, this difference is determined with the goal of enabling the scanning driver to obtain a large resonance swing amplitude while reducing non-linear vibration. Ideally, when the working frequency, the natural frequency of the fiber optic cantilever 201, and the natural frequency of the scanning driver 100 are all equal, the fiber optic cantilever 201 can obtain a larger swing amplitude in the working state to increase the image size or field of view. However, the inventor found that at the same resonance frequency point (such as when the working frequency is the same as a certain order natural frequency when the scanning driver 100 vibrates in the second direction, and / or when the working frequency is the same as a certain order natural frequency when the fiber optic cantilever 201 vibrates in the second direction), the working fiber optic scanner will become a complex non-linear vibration system, and the responses of the scanning driver 100 and / or the fiber optic cantilever 201 are all non-linear. Non-linear vibration will cause the vibration of the fiber optic cantilever to become unstable, vulnerable to interference, difficult to control, and even the scanning trajectory may deviate from the ideal grid-like trajectory. When performing image display, such an abnormal trajectory will seriously affect the image display effect. Therefore, the optimal working condition is that the working frequency is near a certain order natural frequency when the fiber optic cantilever 201 vibrates in the first direction, and the working frequency is also near a certain order natural frequency when the scanning driver 100 vibrates in the first direction, so that a large resonance swing amplitude can be obtained while reducing non-linear vibration.

[0055] Preferably, the operating frequency is near the first natural frequency when the fiber optic cantilever 201 vibrates in the second direction or near higher-order natural frequencies when the fiber optic cantilever 201 vibrates in the second direction. At the same time, the operating frequency is also near the second natural frequency when the scanning driver 100 vibrates in the second direction or near higher-order natural frequencies when the scanning driver 100 vibrates in the second direction.

[0056] The amplitudes of the scanning driver 100 in the first and second directions are both defined by the imaging specification requirements. The low-frequency vibration of the scanning driver 100 in the first direction is generally the first-order vibration of the scanning driver 100. Therefore, on the premise that the amplitude in the first direction is fixed, the length of the beam (which can also be called the front-end cantilever) formed by the scanning driver 100 from the self-supporting member 300 to the first free end 101 of the scanning driver 100 is usually fixed, and this length is determined by the amplitude in the first direction. Therefore, in order to reduce the overall length of the scanning driver 100, it is necessary to make the length of the tail cantilever formed by the scanning driver 100 from the self-supporting member 300 to the second free end 102 of the scanning driver 100 as small as possible. Therefore, preferably, the supporting member 300 is located at the vibration node when the scanning driver 100 vibrates in the second direction at the operating frequency, and is located at the vibration node of the rigid connecting member 130 and closest to the second free end 102.

[0057] In order to further reduce the length of the tail cantilever, preferably, the mass per unit front-back length of the part of the scanning driver 100 near the second free end 102 is greater than the mass per unit front-back length of the rest of the scanning driver 100. This makes the position of the vibration node closest to the second free end 102 of the scanning driver 100 at the operating frequency closer to the second free end 102, thereby achieving the purpose of reducing the length of the tail cantilever. As described above, since the length of the front-end cantilever is fixed, this reduces the overall length of the scanning driver 100, which is beneficial to the miniaturized design of the fiber optic scanner.

[0058] Furthermore, by adjusting parameters such as the material, size, shape, and weight of the rigid connecting member 130, the vibration node of the rigid connecting member closest to the second free end 102 can be further offset toward the second free end 102 side. And most preferably, the vibration node closest to the second free end 102 is located at the rearmost end of the rigid connecting member 130, that is, the end of the rigid connecting member 130 connected to the second actuator.

[0059] Meanwhile, on the basis of the above, it is also possible to make the connection between the support member 300 and the scanning actuator 100 coincide with or be close to the vibration node when the scanning actuator 100 vibrates along the first direction at the low-frequency driving frequency for frame scanning. That is, the node of the horizontal bending mode of the scanning actuator 100 at the high-frequency line scanning frequency coincides with or is close to the node of the vertical bending mode of the scanning actuator 100 at the low-frequency frame scanning frequency at the connection with the support member 300. In this way, the influence of the support member 300 on the characteristic frequency of the mode required for the operation of the scanning actuator 100 can be minimized.

[0060] As a preferred embodiment, the support member 300 only provides support for the scanning actuator 100 without restricting the vibration of the scanning actuator 100, and the support member 300 does not affect the normal transmission of mechanical waves in the scanning actuator 100. Thus, the influence of the support member 300 on the working state of the scanning actuator 100 can be reduced. Specifically, the support member 300 can be made of a material with a certain elastic deformation ability, or the contact area between the support member 300 and the scanning actuator 100 can be minimized as much as possible. For example, the support member can be a support rod that extends in the vertical direction and is arranged at the central position of the scanning actuator in the left-right direction, which is one of the positions where the deformation amount is the smallest when the scanning actuator vibrates in the left-right direction at the working frequency. Another example is that the support member is a support thin plate arranged at the vibration node when the scanning actuator vibrates along the first direction at the working frequency, so as to minimize the contact area between the support member and the scanning actuator.

[0061] It should be noted that the above embodiments are illustrative of the present invention rather than restrictive of the present invention, and those skilled in the art can design alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word "comprising" or "including" does not exclude the presence of elements or steps not listed in the claims. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The use of the words first, second, and third, etc. does not denote any order, and these words can be interpreted as names.

[0062] All features disclosed in this specification, except for mutually exclusive features, can be combined in any manner.

[0063] Any feature disclosed in this specification (including any additional claims, abstract, and drawings), unless specifically stated, can be replaced by other equivalent or similar-purpose alternative features. That is, unless specifically stated, each feature is only an example of a series of equivalent or similar features.

[0064] The present invention is not limited to the foregoing specific embodiments. The present invention extends to any new feature or any new combination disclosed in this specification, as well as to any new method or process step or any new combination disclosed.

Claims

1. An optical fiber scanner that avoids the influence of the slow axis on the response characteristics of the fast axis, characterized in that, it includes a scanning driver and an optical fiber. The scanning driver is fixedly connected to the base through a support member, the scanning driver includes a fast axis driving part, a rigid connecting member, and a slow axis driving part that are arranged in sequence from back to front; the fast axis driving part includes a first piezoelectric block actuating part and a second piezoelectric block actuating part that are symmetrically arranged left and right. Both the first piezoelectric block actuating part and the second piezoelectric block actuating part expand and contract in the front-back direction under the drive of a drive signal, and the first piezoelectric block actuating part and the second piezoelectric block actuating part expand and contract synchronously and in opposite directions. The rear end of the rigid connecting member is simultaneously connected to the first piezoelectric block actuating part and the second piezoelectric block actuating part, the fast axis driving part drives the scanning driver to vibrate left and right at a high frequency in the horizontal direction to achieve line scanning, and the slow axis driving part drives the scanning driver to vibrate up and down at a low frequency to achieve frame scanning; the optical fiber is fixedly arranged at the front end of the scanning driver in a cantilever support manner, and the part of the optical fiber that extends beyond the front end of the scanning driver forms an optical fiber cantilever, taking the frequency of high-frequency vibration as the working frequency, the support member is arranged at the vibration node when the scanning driver vibrates in the left-right direction at the working frequency, and the connection position between the scanning driver and the support member is located at the rigid connecting member.

2. An optical fiber scanner that avoids the influence of the slow axis on the response characteristics of the fast axis according to claim 1, characterized in that, the base includes a housing for encapsulating the optical fiber scanner or a base for installing the optical fiber scanner.

3. An optical fiber scanner that avoids the influence of the slow axis on the response characteristics of the fast axis according to claim 1, characterized in that, the slow axis driving part includes any one of a piezoelectric ceramic actuator, a magnetostrictive actuator, and a microelectromechanical brake.

4. An optical fiber scanner that avoids the influence of the slow axis on the response characteristics of the fast axis according to claim 3, characterized in that, the slow axis driving part is a piezoelectric sheet actuator, and the piezoelectric sheet actuator is parallel to the horizontal plane.

5. An optical fiber scanner that avoids the influence of the slow axis on the response characteristics of the fast axis according to claim 1, characterized in that, the working frequency is near a certain natural frequency when the optical fiber cantilever vibrates in the second direction, and the working frequency is also near a certain natural frequency when the scanning driver vibrates in the second direction.

6. An optical fiber scanner that avoids the influence of the slow axis on the response characteristics of the fast axis according to claim 5, characterized in that, there is a difference between the working frequency and a certain natural frequency when the optical fiber cantilever vibrates in the second direction. This difference is determined with the goal of enabling the optical fiber cantilever to obtain a large resonance swing while reducing non-linear vibration; at the same time, there is a difference between the working frequency and a certain natural frequency when the scanning driver vibrates in the second direction. This difference is determined with the goal of enabling the scanning driver to obtain a large resonance swing while reducing non-linear vibration.

7. An optical fiber scanner that avoids the influence of the slow axis on the response characteristics of the fast axis according to claim 1, characterized in that, the support member is located among the vibration nodes when the scanning driver vibrates in the second direction at the working frequency, and is located at the vibration node of the rigid connecting member that is closest to the second free end.

8. A fiber optic scanner for avoiding the influence of the slow axis on the response characteristics of the fast axis as claimed in claim 7, wherein, the vibration node located in the rigid connecting member and closest to the second free end is located at the rearmost end of the rigid connecting member, that is, the end of the rigid connecting member connecting the second actuator.

9. A fiber optic scanner for avoiding the influence of the slow axis on the response characteristics of the fast axis as claimed in claim 8, wherein, the connection between the support member and the scanning actuator coincides with or is close to the vibration node when the scanning actuator vibrates along the first direction at the low-frequency driving frequency for realizing frame scanning.

10. A fiber optic scanner for avoiding the influence of the slow axis on the response characteristics of the fast axis as claimed in claim 1, wherein, the support member only provides support for the scanning driver but does not restrict the vibration of the scanning driver, and the support member does not affect the normal transmission of mechanical waves in the scanning driver.

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