CN219799890U - Optical fiber scanner - Google Patents

Abstract

The utility model discloses an optical fiber scanner, which comprises a scanning actuator and an optical fiber, wherein the optical fiber is fixedly arranged at a first free end of the scanning actuator in a cantilever supporting manner, the first free end of the scanning actuator is driven by a driving signal to perform two-dimensional vibration, the two-dimensional vibration consists of high-frequency vibration along a first direction and low-frequency vibration along a second direction which are simultaneously operated, the frequency of the high-frequency vibration is used as a working frequency, the scanning actuator is fixedly connected with a base body through a supporting piece, and the supporting piece is arranged at a vibration node when the scanning actuator vibrates along the first direction under the working frequency. According to the utility model, under the condition of changing the clamping conditions, the characteristic frequency of the mode required by the operation of the optical fiber scanner is not changed, the image display can be consistently and accurately carried out, and the scanning track is not changed; the universality of the optical fiber scanner is improved, the requirements on installation accuracy and consistency of installation conditions are reduced, and the installation difficulty is reduced.

Description

Optical fiber scanner

Technical Field

The utility model relates to the technical field of optical fiber scanning image display, in particular to an optical fiber scanner.

Background

The miniature optical fiber scanning device which drives the optical fiber cantilever to scan by the piezoelectric actuator has important application prospect in the technical fields of laser radar, laser projection, miniature endoscope and the like, and the mechanical resonance principle is utilized to enable the optical fiber cantilever to realize a larger scanning range.

The scanning mode of the optical fiber scanner can be classified into a spiral scanning type, a raster scanning type and a lissajous scanning type. The miniature piezoelectric scanning device using spiral scanning and Lissajous scanning generally has a symmetrical structure, is small in size and high in scannable speed, but the spiral scanning density is uneven, and the resonance frequencies of two axes are the same, so that mechanical coupling exists, a scanning track is deteriorated, and the scanning track is difficult to completely eliminate through post-treatment; the use of raster scan requires that the two axes scan frequency differ significantly, one axis scan frequency is fast, the line scan is achieved, the other axis scan frequency is slow, the frame scan is achieved, and the fast axis utilizes fiber resonance to achieve amplification.

As shown in fig. 1, a scanning actuator 100 (e.g., a piezoelectric actuator) of a conventional optical fiber scanner generally has a fixed end 101 and a free end 102, the fixed end 101 being fixedly mounted to a base 300, and an optical fiber 200 being fixedly mounted to the free end 102 in a cantilever-supported manner. The inventor found in the study that the same scanner is mounted on the same base in different fixing modes or on different bases in the same fixing mode, which can cause the characteristic frequency of the mode required by the scanner to change, and the characteristic frequency is shown as image distortion, the image can not be accurately and normally displayed, namely the accurate two-dimensional scanning can not be accurately and normally performed, and the scanning track is changed.

Meanwhile, vibration is transmitted through the base in the working process of the scanning actuator, noise is generated, and poor experience is generated when the optical fiber scanner is used for products worn by users such as AR glasses.

Disclosure of Invention

The embodiment of the utility model provides an optical fiber scanner, which is used for at least solving the technical problem that a fixed mode can influence the characteristic frequency of a mode required by the operation of the scanner.

In order to achieve the above object, the present utility model provides an optical fiber scanner, including a scanning actuator and an optical fiber, wherein one end of the scanning actuator is a first free end, and the other end is a second free end, the optical fiber is fixedly disposed at the first free end of the scanning actuator in a cantilever supporting manner, a portion of the optical fiber beyond the first free end of the scanning actuator forms an optical fiber cantilever, the first free end of the scanning actuator is driven by a driving signal to perform two-dimensional vibration, the two-dimensional vibration is composed of high-frequency vibration along a first direction and low-frequency vibration along a second direction which are simultaneously operated, the high-frequency vibration is used for realizing line scanning, the low-frequency vibration is used for realizing frame scanning, the scanning actuator is fixedly connected with a base body by a support member, and the support member is disposed at a vibration node when the scanning actuator vibrates along the first direction at the working frequency.

Through experimental comparison, the optical fiber scanner provided by the utility model can display images consistently and accurately without changing the characteristic frequency of the mode required by the operation of the optical fiber scanner under the condition of changing clamping conditions (such as clamping force, clamping position and the like), and the scanning track is not changed. The universality of the optical fiber scanner is improved, the requirements on installation accuracy and consistency of installation conditions are reduced, and the installation difficulty is reduced. Meanwhile, the supporting piece is arranged at the vibration node, and the vibration cannot be transmitted through the supporting piece due to the fact that the displacement of the vibration node is extremely small, so that the technical problems of vibration transmission and noise generation are solved.

The substrate is a shell for packaging the optical fiber scanner or a base for installing the optical fiber scanner.

The vibration mode of the scanning actuator refers to the macroscopic structure form of each part of the system at a certain moment, wherein the displacement directions and the magnitudes of different positions on the vibration mode are continuously changed, and some space structure positions with the displacement of 0 or the minimum all the time become 'dead points' or 'nodes', and the nodes reflect the main mode of influencing the system vibration under the frequency. The mode represents a form of resonance of a certain order. In the mathematical model, the mode refers to the characteristic value of the system characteristic equation, and the vibration mode is the characteristic vector.

Taking the transverse bending vibration of the cantilever beam as an example, in each order resonance mode of the transverse bending vibration of the cantilever beam, the intersection point with the transverse axis means that the displacement is always 0, namely a fixed point and a node, one node is arranged in a first order vibration mode, 2 nodes are correspondingly arranged in a 2-order vibration mode, 3 nodes are arranged in a 3-order vibration mode, and the like.

Specifically, the operating frequency is near a certain order natural frequency when the optical fiber cantilever vibrates in the first direction, and the operating frequency is also near a certain order natural frequency when the scanning actuator vibrates in the first direction (since the mass of the optical fiber is small, the vibration characteristics of a system formed by the optical fiber and the scanning actuator can be equivalent to the vibration characteristics of the scanning actuator).

The scan actuator, the fiber cantilever, and the scanner system of the scan actuator and the fiber each have a natural frequency based on one or more properties, typically the natural frequency is a frequency characteristic inherent in the device, and in some examples the natural frequency and resonance frequency (or resonant frequency) are equivalent. The one or more attributes include, but are not limited to: material, young's modulus, cross-sectional secondary distance, density, cross-sectional area, length, and/or mode constant, etc.

The natural frequency of the device does not have only one frequency point, but has a series of multiple frequency points distributed according to a certain rule, i.e., there are multiple orders (orders).

The fact that the operating frequency is near a certain order natural frequency when the optical fiber cantilever vibrates along the first direction, and the operating frequency is near a certain order natural frequency when the scanning actuator vibrates along the first direction means that a difference exists between the operating frequency and the certain order natural frequency when the optical fiber cantilever vibrates along the first direction, for example: the difference between tens and thousands of Hz is determined by the goal that the difference can obtain large resonance swing and reduce nonlinear vibration in the actual operation process. Meanwhile, a difference exists between the working frequency and a certain order natural frequency when the scanning actuator vibrates along the first direction, for example: the difference between tens and thousands of Hz is determined by the goal that the difference can obtain large resonance swing and reduce nonlinear vibration in the actual operation process. Ideally, the working frequency, the natural frequency of the optical fiber cantilever, and the natural frequency of the scanning actuator are equal, and the optical fiber cantilever can obtain a larger swing in the working state so as to increase the picture size or the field of view. However, the inventors have found that at the same resonance frequency (e.g., the same operating frequency as the natural frequency of the certain order of vibration of the scanning actuator in the first direction, and/or the same operating frequency as the natural frequency of the certain order of vibration of the fiber suspension arm in the first direction), the operating fiber scanner becomes a complex nonlinear vibration system, and the response of the scanning actuator and/or the fiber suspension arm is nonlinear. The nonlinear vibration can cause the vibration instability of the optical fiber cantilever, is easy to be disturbed and difficult to control, even the scanning track can deviate from an ideal grid track, and when the image display is carried out, the abnormal track can seriously influence the display effect of the image. Therefore, the optimal working condition is that the working frequency is near a certain order natural frequency when the optical fiber cantilever vibrates along the first direction, and the working frequency is also near a certain order natural frequency when the scanning actuator vibrates along the first direction, so that a large resonance swing can be obtained, and nonlinear vibration can be reduced.

Preferably, the operating frequency is near a first order natural frequency of the fiber cantilever when vibrating in the first direction or near a higher order natural frequency of the fiber cantilever when vibrating in the first direction, and the operating frequency is near a second order natural frequency of the scanning actuator when vibrating in the first direction or near a higher order natural frequency of the scanning actuator when vibrating in the first direction.

Alternatively, the scanning actuator may be any one of a piezoelectric ceramic actuator, a magnetostrictive actuator, and a microelectromechanical actuator.

The amplitude of the scanning actuator in both the first and second directions is defined by imaging specifications, the vibration of the scanning actuator in the second direction being typically a first order vibration of the scanning actuator, and thus the length of the beam (also referred to as the front cantilever) from the scanning actuator's support to the first free end of the scanning actuator is typically fixed, with the amplitude in the second direction being determined by the amplitude in the second direction. Therefore, in order to reduce the overall length of the scan actuator, the length of the tail boom of the scan actuator from the support to the second free end of the scan actuator needs to be as small as possible, so that it is preferred that the support is located at the vibration node of the scan actuator closest to the second free end at the operating frequency.

In order to further reduce the length of the tail boom, it is preferable that the mass per unit of the front-to-back length of the portion of the scanning actuator near the second free end is greater than the mass per unit of the front-to-back length of the remainder of the scanning actuator, so that the position of the vibration node of the scanning actuator closest to the second free end at the operating frequency is closer to the second free end, thereby achieving the purpose of reducing the length of the tail boom. As mentioned above, the fixed length of the front cantilever reduces the overall length of the scanning actuator, which is beneficial to the miniaturization design of the optical fiber scanner.

As a preferred embodiment, the direction from the second free end to the first free end is a back-to-front direction, and the first direction is a left-to-right direction, and the scanning actuator is composed of a piezoelectric ceramic block fast axis driving part and a piezoelectric ceramic block slow axis driving part which are sequentially connected, and the piezoelectric ceramic block fast axis driving part and the piezoelectric ceramic block slow axis driving part are sequentially arranged along the back-to-front direction.

The piezo-ceramic mass fast axis driving part has a larger mass per unit length in the front-rear direction, which makes the vibration node of the scanning actuator closest to the second free end at the operating frequency closer to the second free end of the scanning actuator.

Likewise, to bring the vibration node of the scanning actuator closest to the second free end at the operating frequency closer to the second free end of the scanning actuator, another conceivable embodiment is: the second free end (rear end) of the scanning actuator is fixedly provided with a balancing weight. The addition of the balancing weight can enable the vibration node of the scanning actuator closest to the second free end to move backwards under the working frequency, so that the purpose of reducing the length of the tail cantilever is achieved.

Further preferably, by adjusting the size, shape and weight of the balancing weight, the vibration node of the scanning actuator when vibrating in the second direction at the working frequency can be located at the connection position of the support and the scanning actuator, or the vibration node of the scanning actuator when vibrating in the second direction at the working frequency can be close to the connection position of the support and the scanning actuator. In general, the correction signal for the trajectory of the dither of the scanning actuator in the first direction comprises a dither signal for driving the scanning actuator in the second direction, the driving frequency of the dither signal being the same as the operating frequency, so that the driving of the correction signal and the response of the scanning actuator to the correction signal are likewise unaffected or less affected by the clamping condition when the connection of the support to the scanning actuator is likewise close to or coincides with the vibration node of the scanning actuator vibrating in the second direction at the operating frequency; nor does it transmit vibrations, or less vibrations, through the support.

More preferably, by adjusting the size, shape and weight of the balancing weight, the joint of the support piece and the scanning actuator can be overlapped or close to a vibration node of the scanning actuator when the scanning actuator vibrates along the second direction under the low-frequency driving frequency for realizing frame scanning. That is, the node of the horizontal bending mode of the scanning actuator at the high frequency line scanning frequency and the node of the vertical bending mode of the scanning actuator at the low frequency frame scanning frequency coincide with or are close to each other at the connection of the support. Thus, the influence of the support on the characteristic frequency of the mode required by the operation of the scanning actuator can be reduced to the greatest extent.

In the most preferred embodiment, the rear end of the fast shaft driving part of the piezoelectric ceramic block is connected with the balancing weight.

It is further preferred that the support only provides support to the scanning actuator but does not limit the vibration of the scanning actuator, the support not affecting the normal transmission of mechanical waves at the scanning actuator. Thereby reducing the influence of the support on the operating state of the scanning actuator. In particular, a material with a certain elastic deformation capability can be used, or the contact area between the support and the scanning actuator can be reduced as much as possible.

One or more technical solutions in the embodiments of the present utility model at least have the following technical effects or advantages:

by adopting the optical fiber scanner, under the condition of changing clamping conditions (such as clamping force, clamping position and the like), the characteristic frequency of the mode required by the operation of the optical fiber scanner is not changed, the image display can be consistently and accurately carried out, and the scanning track is not changed. The universality of the optical fiber scanner is improved, the requirements on installation accuracy and consistency of installation conditions are reduced, and the installation difficulty is reduced. Meanwhile, the supporting piece is arranged at the vibration node, and the vibration cannot be transmitted through the supporting piece due to the fact that the displacement of the vibration node is extremely small, so that the technical problems of vibration transmission and noise generation are solved.

And the part of the scanning actuator close to the second free end adopts a material or structure with larger mass per unit length, and/or the length of the tail cantilever is reduced in a mode that the scanning actuator is connected with the balancing weight by the second free end, so that the whole length of the scanning actuator is reduced, and the miniaturization design of the optical fiber scanner is facilitated.

Drawings

FIG. 1 is a schematic diagram of a scan actuator mounting structure of a conventional fiber optic scanner;

FIG. 2 is a schematic diagram of the structure of the present utility model;

FIG. 3 is a schematic diagram of an embodiment of the present utility model;

FIG. 4 is a schematic diagram of a second embodiment of the present utility model;

FIG. 5 is a schematic structural view of a third embodiment of the present utility model;

fig. 6 is a schematic structural diagram of a fourth embodiment of the present utility model.

Detailed Description

The following description of the embodiments of the present utility model will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present utility model, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

As shown in fig. 2, an embodiment of the present utility model provides an optical fiber scanner, including a scanning actuator 100 and an optical fiber 200, where one end of the scanning actuator 100 is a first free end 101, and the other end is a second free end 102, the optical fiber 200 is fixedly disposed at the first free end 101 of the scanning actuator 100 in a cantilever supporting manner, a portion of the optical fiber 200 beyond the first free end 101 of the scanning actuator 100 forms an optical fiber cantilever 201, the first free end 101 of the scanning actuator 100 is driven by a driving signal to perform two-dimensional vibration, the two-dimensional vibration is composed of high-frequency vibration along a first direction and low-frequency vibration along a second direction that are simultaneously operated, the high-frequency vibration is used to implement line scanning, the low-frequency vibration is used to implement frame scanning, and the scanning actuator 100 is fixedly connected with a base 400 through a support 300, where the support 300 is disposed at a vibration node when the scanning actuator 100 vibrates along the first direction at the working frequency.

Through experimental comparison, the optical fiber scanner provided by the utility model can display images consistently and accurately without changing the characteristic frequency of the mode required by the operation of the optical fiber scanner under the condition of changing clamping conditions (such as clamping force, clamping piece materials, base materials and the like), and the scanning track is not changed. The universality of the optical fiber scanner is improved, the requirements on installation accuracy and consistency of installation conditions are reduced, and the installation difficulty is reduced. Meanwhile, since the supporting piece 300 is arranged at the vibration node, the vibration cannot be transmitted through the supporting piece 300 because the displacement of the vibration node is extremely small, and the technical problems of vibration transmission and noise generation are solved.

The base 400 is a housing for housing the optical fiber scanner or a base for mounting the optical fiber scanner.

The vibration mode of the scan actuator 100 refers to the macroscopic structure form of each part of the system at a certain moment, which is represented by different vibration or displacement states, the displacement directions and the magnitudes of different positions on the vibration mode continuously change, wherein some spatial structure positions with the displacement of 0 or the minimum all the time become 'dead points' or 'nodes', and the nodes reflect the main mode of influencing the vibration of the system under the frequency. The mode represents a form of resonance of a certain order. In the mathematical model, the mode refers to the characteristic value of the system characteristic equation, and the vibration mode is the characteristic vector.

Taking the transverse bending vibration of the cantilever beam as an example, in each order resonance mode of the transverse bending vibration of the cantilever beam, the intersection point with the transverse axis means that the displacement is always 0, namely a fixed point and a node, one node is arranged in a first order vibration mode, 2 nodes are correspondingly arranged in a 2-order vibration mode, 3 nodes are arranged in a 3-order vibration mode, and the like.

Specifically, the operating frequency is near a certain order natural frequency when the optical fiber cantilever 201 vibrates in the first direction, and the operating frequency is also near a certain order natural frequency when the scanning actuator 100 vibrates in the first direction (since the mass of the optical fiber is small, the vibration characteristics of the system composed of the optical fiber and the scanning actuator can be equivalent to those of the scanning actuator).

The scan actuator 100, the fiber cantilever 201, and the scanner system comprised of the scan actuator 100 and the fiber 200 each have a natural frequency based on one or more properties, typically the natural frequency is a frequency characteristic inherent in the device, and in some examples, the natural frequency and resonant frequency (or resonant frequency) are equivalent. The one or more attributes include, but are not limited to: material, young's modulus, cross-sectional secondary distance, density, cross-sectional area, length, and/or mode constant, etc.

The natural frequency of the device does not have only one frequency point, but has a series of multiple frequency points distributed according to a certain rule, i.e., there are multiple orders (orders).

The fact that the operating frequency is near a certain order natural frequency when the optical fiber cantilever 201 vibrates in the first direction, and the operating frequency is near a certain order natural frequency when the scan actuator 100 vibrates in the first direction, means that there is a difference between the operating frequency and the certain order natural frequency when the optical fiber cantilever 201 vibrates in the first direction, for example: the difference between tens and thousands of Hz is determined by the goal that the difference can obtain large resonance swing and reduce nonlinear vibration in the actual operation process. At the same time, there is a difference between the operating frequency and a certain order natural frequency of the scan actuator 100 when vibrating in the first direction, such as: the difference between tens and thousands of Hz is determined by the goal that the difference can obtain large resonance swing and reduce nonlinear vibration in the actual operation process. Ideally, the operating frequency, the natural frequency of the fiber suspension arm 201, and the natural frequency of the scan actuator 100 are equal, and the fiber suspension arm 201 can be made to have a larger swing in operation to increase the screen size or field of view. However, the inventors have found that at the same resonance frequency (e.g., at the same operating frequency as a certain order natural frequency of the scanning actuator 100 when vibrating in the first direction, and/or at the same operating frequency as a certain order natural frequency of the fiber optic cantilever 201 when vibrating in the first direction), the operating fiber optic scanner becomes a complex nonlinear vibration system, and the response of the scanning actuator 100 and/or the fiber optic cantilever 201 is nonlinear. The nonlinear vibration can cause the vibration instability of the optical fiber cantilever, is easy to be disturbed and difficult to control, even the scanning track can deviate from an ideal grid track, and when the image display is carried out, the abnormal track can seriously influence the display effect of the image. Thus, the optimum operating condition is that the operating frequency is near a certain order natural frequency when the optical fiber cantilever 201 vibrates in the first direction, and the operating frequency is also near a certain order natural frequency when the scan actuator 100 vibrates in the first direction, so that a large resonance swing can be obtained, and nonlinear vibration can be reduced.

Preferably, the operating frequency is near a first order natural frequency of the fiber cantilever 201 when vibrating in the first direction or near a higher order natural frequency of the fiber cantilever 201 when vibrating in the first direction, and the operating frequency is near a second order natural frequency of the scanning actuator 100 when vibrating in the first direction or near a higher order natural frequency of the scanning actuator 100 when vibrating in the first direction.

Alternatively, the scanning actuator 100 may be any one of a piezoceramic actuator, a magnetostrictive actuator, and a microelectromechanical actuator.

The amplitude of the scanning actuator 100 in both the first and second directions is defined by imaging specifications, and the vibration of the scanning actuator 100 in the low frequency vibration of the second direction is typically a first order vibration of the scanning actuator 100, so that with the amplitude of the second direction fixed, the length of the beam (also referred to as the front cantilever) formed from the support 300 of the scanning actuator 100 to the first free end 101 of the scanning actuator 100 is typically fixed, which is determined by the amplitude of the second direction. Therefore, in order to reduce the overall length of the scan actuator 100, the length of the tail boom of the scan actuator 100 from the support 300 to the second free end 102 of the scan actuator 100 needs to be as small as possible, so that it is preferable that the support 300 is located at the vibration node of the scan actuator 100 closest to the second free end 102 at the operating frequency.

In order to further reduce the length of the tail boom, it is preferable that the mass per unit of the front-to-back length of the portion of the scan actuator 100 near the second free end 102 is greater than the mass per unit of the front-to-back length of the rest of the scan actuator 100, as shown in fig. 3, so that the position of the vibration node of the scan actuator 100 closest to the second free end 102 at the operating frequency is closer to the second free end 102, thereby achieving the purpose of reducing the length of the tail boom. As previously described, this allows the overall length of the scan actuator 100 to be reduced due to the fixed length of the front cantilever, facilitating a compact design of the fiber scanner.

As a preferred embodiment, as shown in fig. 4, the scanning actuator 100 is configured by a piezoelectric ceramic block fast axis driving part 110 and a piezoelectric ceramic block slow axis driving part 120 which are sequentially connected, and the piezoelectric ceramic block fast axis driving part 110 and the piezoelectric ceramic block slow axis driving part 120 are sequentially arranged in a direction from back to front, with the direction from the second free end 102 to the first free end 101 being the backward forward direction, and with the first direction being the left-right direction. The piezoelectric ceramic block fast axis driving part 110 includes a first piezoelectric block actuating part 111 and a second piezoelectric block actuating part 112 which are symmetrically arranged left and right, the first piezoelectric block actuating part 111 and the second piezoelectric block actuating part 112 are respectively stretched in the front-back direction under the driving of a driving signal, the first piezoelectric block actuating part 111 and the second piezoelectric block actuating part 112 synchronously stretch in the opposite directions, and the rear end of the slow axis driving part 120 is simultaneously connected with the first piezoelectric block actuating part 111 and the second piezoelectric block actuating part 112. Thus, the slow-axis driving section 120 is driven to vibrate horizontally and horizontally by the synchronous reverse expansion and contraction of the first piezoelectric block actuation section 111 and the second piezoelectric block actuation section 112, and at the same time, the slow-axis driving section 120 vibrates vertically with respect to its rear end by the driving signal thereof. The slow shaft driving part 120 may be any one of a piezoelectric ceramic actuator, a magnetostrictive actuator, and a microelectromechanical actuator, and is not required.

The first piezoelectric block actuation portion 111 and the second piezoelectric block actuation portion 112 have a larger mass per unit length in the front-rear direction, which brings the vibration node of the scan actuator 100 closest to the second free end 102 at the operating frequency closer to the second free end 102 of the scan actuator 100.

Likewise, to bring the vibration node of the scanning actuator closest to the second free end 102 at the operating frequency closer to the second free end 102 of the scanning actuator 100, another contemplated embodiment is: as shown in fig. 5, the second free end 102 (rear end) of the scan actuator 100 is fixedly provided with a weight 130. The addition of the weight 130 may enable the vibration node of the scan actuator 100 closest to the second free end 102 to be moved backward at the operating frequency, thereby achieving the goal of reducing the length of the tail boom.

It is further preferred that the size, shape and weight of the weight 130 be adjusted such that the vibration node of the scan actuator 100 when vibrating in the second direction at the operating frequency is located at the connection of the support 300 and the scan actuator 100, or such that the vibration node of the scan actuator when vibrating in the second direction at the operating frequency is close to the connection of the support and the scan actuator. In general, the correction signal for the trajectory of the dither of the scanning actuator in the first direction comprises a dither signal for driving the scanning actuator in the second direction, the driving frequency of the dither signal being the same as the operating frequency, so that the driving of the correction signal and the response of the scanning actuator to the correction signal are likewise unaffected or less affected by the clamping condition when the connection of the support to the scanning actuator is likewise close to or coincides with the vibration node of the scanning actuator vibrating in the second direction at the operating frequency; nor does it transmit vibrations, or less vibrations, through the support 300.

More preferably, by adjusting the size, shape and weight of the weight 130, the connection between the support 300 and the scan actuator 100 may be overlapped or close to the vibration node of the scan actuator 100 when vibrating in the second direction at the low frequency driving frequency for achieving the frame scanning. That is, the node of the horizontal bending mode of the scan actuator 100 at the high frequency line scan frequency and the node of the vertical bending mode of the scan actuator 100 at the low frequency frame scan frequency coincide with or are close to each other at the connection of the support 300. This minimizes the impact of the support 300 on the characteristic frequency of the mode in which the scan actuator 100 is required to operate.

Of course, in the most preferred embodiment, the weights 130 may be fixedly connected to the rear ends of the first piezoelectric block actuation portion 111 and the second piezoelectric block actuation portion 112 in the above embodiment, as shown in fig. 6.

It is further preferred that the support 300 only provides support for the scan actuator 100 but does not limit the vibration of the scan actuator 100, and that the support 300 does not affect the normal transmission of mechanical waves at the scan actuator 100. So that the influence of the support 300 on the operation state of the scan actuator 100 can be reduced. In particular, the support 300 may be made of a material having a certain elastic deformation capability, or the contact area between the support 300 and the scan actuator 100 may be minimized. For example, the support member may be a support rod disposed at a vibration node of the scan actuator when vibrating in the first direction at the operating frequency, the support rod extending in the second direction and being disposed at a center position of the scan actuator in the first direction, which is one of positions where the deformation amount of the scan actuator is minimum when vibrating in the first direction at the operating frequency. For another example, the support member is a support sheet disposed at a vibration node of the scan actuator when vibrating in the first direction at the operating frequency, so as to minimize a contact area between the support member and the scan actuator.

It should be noted that the above-mentioned embodiments illustrate rather than limit the utility model, and that those skilled in the art will be able to 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 "comprises" does not exclude the presence of elements or steps not listed in a claim. 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, third, etc. do not denote any order, and the words may be interpreted as names.

All of the features disclosed in this specification, except mutually exclusive features, may be combined in any manner.

Any feature disclosed in this specification (including any accompanying claims, abstract and drawings), may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. That is, each feature is one example only of a generic series of equivalent or similar features, unless expressly stated otherwise.

The utility model is not limited to the specific embodiments described above. The utility model extends to any novel one, or any novel combination, of the features disclosed in this specification, as well as to any novel one, or any novel combination, of the steps of the method or process disclosed.

Claims (10)

1. The optical fiber scanner is characterized by comprising a scanning actuator and an optical fiber, wherein one end of the scanning actuator is a first free end, the other end of the scanning actuator is a second free end, the optical fiber is fixedly arranged at the first free end of the scanning actuator in a cantilever supporting mode, the part of the optical fiber, which exceeds the first free end of the scanning actuator, forms an optical fiber cantilever, the first free end of the scanning actuator is driven by a driving signal to vibrate in two dimensions, the two-dimensional vibration is formed by high-frequency vibration along a first direction and low-frequency vibration along a second direction which act simultaneously, the high-frequency vibration is used for realizing line scanning, the low-frequency vibration is used for realizing frame scanning, the frequency of the high-frequency vibration is used as a working frequency, the scanning actuator is fixedly connected with a base body through a supporting piece, and the supporting piece is arranged at a vibration node when the scanning actuator vibrates along the first direction under the working frequency.

2. A fiber optic scanner according to claim 1 wherein the operating frequency is about a certain order of natural frequency of the fiber optic cantilever when vibrating in the first direction, and the operating frequency is also about a certain order of natural frequency of the scanning actuator when vibrating in the first direction.

3. The optical fiber scanner according to claim 1, wherein the scanning actuator is any one of a piezoceramic actuator, a magnetostrictive actuator and a microelectromechanical actuator.

4. A fibre scanner according to any one of claims 1 to 3, wherein the support member is located at a vibration node of the scanning actuator closest to the second free end at the operating frequency.

5. A fiber optic scanner according to claim 4 wherein the mass per unit of front-to-back length of the portion of the scan actuator proximate the second free end is greater than the mass per unit of front-to-back length of the remainder of the scan actuator such that the vibration node of the scan actuator closest to the second free end when vibrating in the first direction at the operating frequency is located closer to the second free end to reduce the length of the trailing arm.

6. The optical fiber scanner according to claim 5, wherein the scanning actuator is composed of a piezoelectric ceramic block fast axis driving part and a piezoelectric ceramic block slow axis driving part which are sequentially connected, and the piezoelectric ceramic block fast axis driving part and the piezoelectric ceramic block slow axis driving part are sequentially arranged along the direction from back to front, wherein the direction from the second free end to the first free end is the backward and forward direction, and the first direction is the left and right direction.

7. The optical fiber scanner according to claim 6, wherein the slow axis driving part is any one of a piezoelectric ceramic actuator, a magnetostrictive actuator and a micro electromechanical actuator.

8. An optical fibre scanner as claimed in any one of claims 1 to 7, wherein the second free end of the scanning actuator is fixedly provided with a counterweight such that the vibration node of the scanning actuator closest to the second free end is located closer to the second free end when the scanning actuator vibrates in the first direction at the operating frequency.

9. A fibre scanner according to any of claims 1 to 8, wherein the connection of the support member to the scanning actuator is close to the vibration node of the scanning actuator when vibrating in the second direction at the operating frequency, or the connection of the support member to the scanning actuator is located at the vibration node of the scanning actuator when vibrating in the second direction at the operating frequency.

10. A fibre scanner according to any of claims 1 to 8, wherein the connection of the support to the scanning actuator is near the vibration node of the scanning actuator when vibrating in the second direction at the low frequency driving frequency at which frame scanning is effected, or the connection of the support to the scanning actuator is at the vibration node of the scanning actuator when vibrating in the second direction at the low frequency driving frequency at which frame scanning is effected.