Small-size Lissajous optical fiber scanner

Abstract

The utility model discloses a small-size Lissajous optical fiber scanner which comprises a cylindrical piezoelectric actuating part, a supporting plate and an optical fiber, the cylindrical piezoelectric actuating part is a two-dimensional scanning piezoelectric actuator, the front end of the cylindrical piezoelectric actuating part is fixedly connected with a base, the supporting plate is arranged in a first through hole, and the optical fiber is arranged in the supporting plate. The rear end of the supporting plate is fixedly connected with the free end of the cylindrical piezoelectric actuating part, the front end of the supporting plate is located in the first through hole or the second through hole, the optical fiber is fixedly arranged at the front end of the supporting plate in a cantilever supporting mode, and the cylindrical piezoelectric actuating part, the supporting plate and the optical fiber form a scanner cantilever. The supporting plate enables a difference value to exist between a certain-order inherent frequency, closest to the V-order inherent frequency in the horizontal direction, of the scanner cantilever in the vertical direction and the V-order inherent frequency in the horizontal direction. The supporting plate and the optical fiber cantilever can be almost completely hidden in the through holes of the cylindrical piezoelectric actuating part and the base, so that the length of the optical fiber scanner in the front-back direction is greatly reduced, and the size of the scanner is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of optical fiber scanner structure, and particularly relates to a small-size Lissajous optical fiber scanner. BACKGROUND

[0002] The optical fiber scanner is a display technology using a scanning driver to control the swing of an optical fiber while the light emitted by the optical fiber, which is mainly used in the technical fields of optical fiber scanning display technology, optical fiber scanning endoscope technology, optical fiber scanning radar and the like. When the optical fiber scanner is applied to image display, the color of the pattern irradiated by the technology is sharp and saturated, the contrast is high, the brightness is high, and the structure volume is very small.

[0003] The optical fiber scanner utilizes the mechanical resonance principle to make the cantilever of the optical fiber realize a large scanning range. The scanning mode of the scanning driver can be divided into spiral scanning, grid scanning and Lissajous scanning. The micro piezoelectric scanning device of the Lissajous scanning generally has two driving parts in two directions, which simultaneously vibrate along two directions. The closer the driving frequencies of the two directions in the Lissajous scanning are, the closer the uniformity (density) of the scanning grid in the two directions is, and theoretically the closer the driving frequencies of the two directions are, the better. However, the closer the inherent frequencies utilized in the two directions of the scanner are, the more obvious the vibration coupling effect is, which can deteriorate the scanning trajectory and cause uncontrolled components in the scanning trajectory, resulting in distortion of the scanning image, which is difficult to completely eliminate through post-processing. Therefore, the inherent frequencies utilized in the two directions of the Lissajous scanner are preferably in a precise difference range, so as to neither cause coupling effect due to too small difference, nor cause non-uniformity due to too large difference.

[0004] However, the Lissajous scanner with inherent frequencies utilized in two directions having a precise difference requires extremely high processing precision, and both the cost of processing equipment and the yield cannot be guaranteed. CONTENT OF THE INVENTION

[0005] The small-size Lissajous optical fiber scanner provided by the present application not only reduces the processing difficulty and improves the processing yield, but also integrates the structure of the scanner and reduces the volume and size of the optical fiber scanner.

[0006] In order to achieve the above-mentioned application purposes, the present application provides a small-size Lissajous optical fiber scanner, which comprises a cylindrical piezoelectric actuating part, a support plate and an optical fiber, the cylindrical piezoelectric actuating part is a two-dimensional scanning piezoelectric actuator,

[0007] The fixed end of the cylindrical piezoelectric actuating part is fixedly connected with the base to be supported by the base, the cylindrical piezoelectric actuating part has a first through hole penetrating through itself in the axial direction, and the base has a second through hole communicating with the first through hole;

[0008] The free end of the cylindrical piezoelectric actuator simultaneously vibrates in a first direction and a second direction, the first direction is perpendicular to the second direction, the free end of the cylindrical piezoelectric actuator is the rear end, the fixed end of the cylindrical piezoelectric actuator is the front end, the first direction is the left-right direction, and the second direction is the vertical direction,

[0009] The support plate is arranged in the first through hole and is arranged in parallel to the horizontal direction, the rear end of the support plate is fixedly connected with the free end of the cylindrical piezoelectric actuator, the front end of the support plate is located in the first through hole or the second through hole, and the length of the support plate can be set according to actual working conditions and is not limited. The optical fiber is fixedly arranged at the front end of the support plate in a cantilever support mode.

[0010] The part of the front end of the support plate fixedly connected with the cylindrical piezoelectric actuator is driven to vibrate in two dimensions by the cylindrical piezoelectric actuator in the first through hole or in the first through hole and the second through hole. The hole diameters of the first through hole and the second through hole are not less than the swing range of the support plate and the optical fiber, that is, the support plate and the optical fiber will not contact the hole wall of the first through hole or the hole wall of the second through hole of the cylindrical piezoelectric actuator in the scanning process.

[0011] The cylindrical piezoelectric actuator, the support plate and the optical fiber constitute a scanner cantilever, the support plate is arranged to make the inherent frequency of the scanner cantilever in the horizontal direction greater than the same order inherent frequency of the scanner cantilever in the vertical direction, and make the scanner cantilever in the vertical direction closest to a certain order inherent frequency of the V order inherent frequency in the horizontal direction and the V order inherent frequency in the horizontal direction, and V is an integer greater than or equal to 1.

[0012] The application utilizes the adjustment of the shape structure and / or size parameter of the support plate to make the inherent frequencies of the scanner cantilever utilized in two directions meet the requirements of being close enough to ensure good scanning effect and having a uniform and dense scanning grid, and also have a sufficient difference to make the vibration of the scanner cantilever in two directions not coupled.

[0013] Therefore, the difference meets the requirements that the vibration of the scanner cantilever in the horizontal direction and in the vertical direction will not be coupled when the cylindrical piezoelectric actuator is driven to perform Lissajous scanning under the driving of the driving signal.

[0014] Generally, the difference range is 10 Hz-12 KHz. Further preferably, the difference range is 1 KHz-10 KHz. The value of the V order inherent frequency in the horizontal direction of the scanner cantilever is selected according to the actual situation, as long as the difference meets the requirements that the scanner cantilever has a sufficient amplitude when the piezoelectric actuator is driven to perform Lissajous scanning, and the vibration of the scanner cantilever in the horizontal direction and in the vertical direction will not be coupled. For those skilled in the art, the numerical selection according to the above description is a conventional technical means in the art.

[0015] The support plate and the cylindrical piezoelectric actuating part have a coinciding part in the front-rear direction, and the support plate and the optical fiber cantilever can be almost completely hidden in the through hole of the cylindrical piezoelectric actuating part and the base, greatly reducing the length of the optical fiber scanner in the front-rear direction and the volume of the scanner.

[0016] Preferably, the inherent frequency of the cylindrical piezoelectric actuating part in the first direction and the inherent frequency of the same order in the second direction are the same or similar. The cylindrical piezoelectric actuating part here refers to the cylindrical piezoelectric actuating part itself, without the support plate and other components such as the optical fiber. The cylindrical piezoelectric actuating part meeting such requirements is a regular-shaped, rotationally-symmetric piezoelectric actuator, which has low processing difficulty, easy-to-control processing error, and high yield.

[0017] The optical fiber is fixedly arranged on the upper surface or the lower surface of the support plate in a cantilever support manner or arranged inside the support plate. The cantilever support manner refers to that the front end of the optical fiber beyond the front end of the support plate forms an optical fiber cantilever, and the part of the optical fiber behind the optical fiber cantilever is fixedly connected with the support plate. As an embodiment in which the optical fiber is arranged inside the support plate, a mounting hole for accommodating the optical fiber is arranged in the support plate body, and the optical fiber is fixedly arranged in the mounting hole in a cantilever support manner.

[0018] The second aspect of the embodiment of the present application provides another small-size Lissajous optical fiber scanner, which comprises a base, a cylindrical piezoelectric actuating part, a sheet piezoelectric actuating part, and an optical fiber.

[0019] The fixed end of the cylindrical piezoelectric actuating part is fixedly connected with the base to be supported by the base, and the cylindrical piezoelectric actuating part has a first through hole penetrating through the cylindrical piezoelectric actuating part in the axial direction, and the base has a second through hole communicating with the first through hole.

[0020] The free end of the cylindrical piezoelectric actuating part vibrates in the first direction, the free end of the cylindrical piezoelectric actuating part is the rear end, the fixed end of the cylindrical piezoelectric actuating part is the front end, the first direction is the left-right direction, and the inherent frequency of the cylindrical piezoelectric actuating part in the left-right direction and the inherent frequency of the cylindrical piezoelectric actuating part in the vertical direction are the same or similar.

[0021] The sheet piezoelectric actuating part is arranged in the first through hole, the sheet piezoelectric actuating part is arranged in a direction parallel to the horizontal plane, the rear end of the sheet piezoelectric actuating part is fixedly connected with the free end of the cylindrical piezoelectric actuating part, the front end of the sheet piezoelectric actuating part is located in the first through hole or the second through hole, the length of the sheet piezoelectric actuating part can be set according to actual working conditions and is not limited, the front end of the sheet piezoelectric actuating part vibrates in the vertical direction, and the optical fiber is fixedly arranged on the front end of the sheet piezoelectric actuating part in a cantilever support manner.

[0022] The part of the front end of the sheet piezoelectric actuating part fixedly connected with the cylindrical piezoelectric actuating part makes two-dimensional vibration under the common driving of the cylindrical piezoelectric actuating part and itself in the first through hole or in the first through hole and the second through hole, and the aperture of the first through hole and the second through hole is set to be not less than the swing range of the sheet piezoelectric actuating part and the optical fiber, i.e. the sheet piezoelectric actuating part and the optical fiber will not contact the hole wall of the first through hole or the hole wall of the second through hole of the cylindrical piezoelectric actuating part in the scanning process,

[0023] The cylindrical piezoelectric actuating part, the sheet piezoelectric actuating part and the optical fiber constitute a scanner cantilever, the sheet piezoelectric actuating part makes the inherent frequency of the scanner cantilever in the horizontal direction greater than the same order inherent frequency of the scanner cantilever in the vertical direction, and makes the scanner cantilever in the vertical direction have a difference between the certain order inherent frequency closest to the V order inherent frequency in the horizontal direction and the V order inherent frequency in the horizontal direction, and V is an integer greater than or equal to 1.

[0024] The scanner cantilever has a first order inherent frequency, a second order inherent frequency, a third order inherent frequency, …, and an N order inherent frequency in the vertical direction, wherein the inherent frequency of a certain order (for example, U order, U is an integer greater than or equal to two) is closest to the V order inherent frequency of the scanner cantilever in the horizontal direction (V is less than U), and the closer the driving frequencies of the two directions in the Lissajous scanning, the closer the uniformity (density) of the scanning grid in the two directions, and the more the number of points, and theoretically the closer the driving frequencies of the two directions, the better, but the closer the inherent frequencies of the scanner cantilever used in the two directions, the more obvious the coupling effect, so the application adjusts the shape structure and / or size parameters of the sheet piezoelectric actuating part, so that the inherent frequencies of the scanner cantilever used in the two directions at the same time meet the requirements of being close enough to ensure good scanning effect and having a uniform and dense scanning grid, and at the same time having a sufficient difference to make the vibration of the scanner cantilever in the two directions not coupled.

[0025] Therefore, the difference meets the requirement that the vibration of the scanner cantilever in the horizontal direction and in the vertical direction will not be coupled when the cylindrical piezoelectric actuating part makes Lissajous scanning under the driving of the driving signal.

[0026] Generally, the difference range is 10 Hz to 12 KHz. Further preferably, the difference range is 1 KHz to 10 KHz. The value of the V order inherent frequency in the horizontal direction of the scanner cantilever is selected according to the selection, as long as the difference meets the requirement that the scanner cantilever has sufficient amplitude when the piezoelectric actuating part is driven to make Lissajous scanning, and the vibration of the scanner cantilever in the horizontal direction and in the vertical direction will not be coupled. For those skilled in the art, numerical selection according to the above description is a conventional technical means in the art.

[0027] The piezoelectric actuator in the shape of a sheet and the piezoelectric actuator in the shape of a cylinder have a coinciding part in the front-rear direction, and the piezoelectric actuator in the shape of a sheet and the optical fiber cantilever can be almost completely hidden in the through hole of the piezoelectric actuator in the shape of a cylinder and the base, greatly reducing the length of the optical fiber scanner in the front-rear direction and the volume of the scanner.

[0028] Preferably, the piezoelectric actuator in the shape of a cylinder has the same or similar natural frequency in the left-right direction and the same order natural frequency in the vertical direction. The piezoelectric actuator in the shape of a cylinder here refers to the piezoelectric actuator in the shape of a cylinder itself, without the piezoelectric actuator in the shape of a sheet and other components such as the optical fiber. The piezoelectric actuator in the shape of a cylinder that meets such requirements is a regular shape and rotationally symmetric piezoelectric actuator, which has low processing difficulty, easy control of processing errors, and high yield.

[0029] Optionally, the piezoelectric actuator in the shape of a sheet is a single piezoelectric sheet actuator or a double piezoelectric sheet actuator. The piezoelectric actuator in the shape of a sheet is also a conventional actuator, which has low processing difficulty. The present application combines two easily processed components to obtain a scanner suitable for Lissajous scanning and with guaranteed anti-coupling effect, which has low processing difficulty and high yield compared to existing Lissajous scanners.

[0030] The optical fiber is fixedly arranged in a cantilever support manner on the upper surface or the lower surface of the piezoelectric actuator in the shape of a sheet or inside the piezoelectric actuator in the shape of a sheet. The cantilever support refers to the part of the optical fiber that protrudes from the front end of the piezoelectric actuator in the shape of a sheet, which constitutes an optical fiber cantilever, and the part of the optical fiber located at the rear side of the optical fiber cantilever is fixedly connected with the piezoelectric actuator in the shape of a sheet. As an embodiment in which the optical fiber is arranged inside the piezoelectric actuator in the shape of a sheet, a mounting hole for accommodating the optical fiber is arranged in the body of the piezoelectric actuator in the shape of a sheet, and the optical fiber is fixedly arranged in the mounting hole in a cantilever support manner.

[0031] The one or more technical solutions in the present application have at least the following technical effects or advantages:

[0032] The present application adjusts the shape and / or size parameters of the support plate to make the natural frequencies of the scanner cantilever in two directions simultaneously meet the requirements of being close enough to ensure good scanning effect and having a uniform and dense scanning grid, while also having a sufficient difference to prevent the vibration of the scanner cantilever in two directions from being coupled.

[0033] The present application makes the natural frequency of the piezoelectric actuator of the Lissajous scanner in the first direction and the natural frequency in the second direction the same or similar. The piezoelectric actuator here refers to the piezoelectric actuator itself, without the support plate and other components such as the optical fiber. The piezoelectric actuator that meets such requirements is a regular shape and rotationally symmetric piezoelectric actuator, which has low processing difficulty, easy control of processing errors, and high yield.

[0034] The support plate and the cylindrical piezoelectric actuating part have a coinciding part in the front-rear direction, and the support plate and the optical fiber cantilever can be almost completely hidden in the through hole of the cylindrical piezoelectric actuating part and the base, greatly reducing the length of the optical fiber scanner in the front-rear direction and the volume of the scanner.

[0035] The application utilizes the shape structure and / or size parameter adjustment of the sheet piezoelectric actuating part, so that the scanner cantilever inherent frequencies in two directions are simultaneously satisfied to be close enough to ensure good scanning effect and have uniform and dense scanning grid, and have sufficient difference to make the vibration of the scanner cantilever in two directions not coupled.

[0036] Since the inherent frequency of the cylindrical piezoelectric actuating part in the left-right direction and the inherent frequency in the vertical direction are the same or similar, the cylindrical piezoelectric actuating part here refers to the first piezoelectric actuating part itself, and does not include the sheet piezoelectric actuating part or other components such as optical fiber. The cylindrical piezoelectric actuating part satisfying such requirements is a regular shape and rotationally symmetric piezoelectric actuator, which has low processing difficulty, easy to control processing error, and high yield.

[0037] The sheet piezoelectric actuating part and the cylindrical piezoelectric actuating part have a coinciding part in the front-rear direction, and the sheet piezoelectric actuating part and the optical fiber cantilever can be almost completely hidden in the through hole of the cylindrical piezoelectric actuating part and the base, greatly reducing the length of the optical fiber scanner in the front-rear direction and the volume of the scanner. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 The figure is a structural schematic diagram of the application;

[0039] Figure 2 The figure is Figure 1 The figure is a structural schematic diagram after removing the base;

[0040] Figure 3 The figure is a structural schematic diagram of the support plate in embodiment 1 or the sheet piezoelectric actuating part in embodiment 2;

[0041] Figure 4 The figure is a structural schematic diagram of a cylindrical piezoelectric actuator;

[0042] Figure 5 The figure is a structural schematic diagram of a square cylindrical piezoelectric actuator. DETAILED DESCRIPTION

[0043] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the application.

[0044] Embodiment 1:

[0045] As shown in Figure 1 , Figure 2 , Figure 3 A small size Lissajous fiber scanner includes a cylindrical piezoelectric actuator 100, a support plate 200 and an optical fiber 300. The cylindrical piezoelectric actuator 100 is a two-dimensional scanning piezoelectric actuator,

[0046] The fixed end of the cylindrical piezoelectric actuator 100 is fixedly connected to a base 400 to be supported by the base 400. The cylindrical piezoelectric actuator 100 has a first through hole 101 extending through the cylindrical piezoelectric actuator 100 in the axial direction. The base 400 has a second through hole 401 communicating with the first through hole 101.

[0047] The free end of the cylindrical piezoelectric actuator 100 simultaneously vibrates in a first direction and a second direction perpendicular to the first direction. The free end of the cylindrical piezoelectric actuator 100 is the rear end, the fixed end of the cylindrical piezoelectric actuator 100 is the front end, the first direction is the left-right direction, and the second direction is the vertical direction.

[0048] The support plate 200 is arranged in the first through hole 101 and arranged in parallel to the horizontal direction. The rear end of the support plate 200 is fixedly connected to the free end of the cylindrical piezoelectric actuator 100. The front end of the support plate 200 is located in the first through hole 101 or the second through hole 401. The length of the support plate 200 can be set according to the actual working condition requirement and is not limited. The optical fiber 300 is fixedly arranged at the front end of the support plate 200 in a cantilever support manner.

[0049] The part of the front end of the support plate 200 fixedly connected to the cylindrical piezoelectric actuator 100 is driven to vibrate in two dimensions by the cylindrical piezoelectric actuator 100 in the first through hole 101 or the first through hole 101 and the second through hole 401. The aperture of the first through hole 101 and the second through hole 401 is not less than the swing range of the support plate 200 and the optical fiber 300, i.e. the support plate 200 and the optical fiber 300 will not contact the hole wall of the first through hole 101 or the hole wall of the second through hole 401 during the scanning process.

[0050] The cylindrical piezoelectric actuator, the support plate 200 and the optical fiber 300 constitute a scanner cantilever. The support plate 200 makes the inherent frequency of the scanner cantilever in the horizontal direction greater than the same order inherent frequency in the vertical direction, and makes the scanner cantilever in the vertical direction closest to the certain order inherent frequency between the V order inherent frequency in the horizontal direction and the V order inherent frequency in the horizontal direction, V is an integer greater than or equal to 1.

[0051] The scanner cantilever has a first-order natural frequency, a second-order natural frequency, a third-order natural frequency, and an N-order natural frequency in the vertical direction, wherein the natural frequency of a certain order (for example, U order, U is an integer greater than or equal to two) is closest to the V-order natural frequency of the scanner cantilever in the horizontal direction (V is less than U), the closer the driving frequencies of the two directions in the Lissajous scanning are, the closer the uniformity (density) of the scanning grid in the two directions is, and the more the number of points is, theoretically, the closer the driving frequencies of the two directions are, the more obvious the coupling effect will be. Therefore, the shape and / or size parameters of the support plate 200 are adjusted to make the natural frequencies of the scanner cantilever in the two directions meet the requirements of being close enough to ensure good scanning effect and having a uniform and dense scanning grid, and at the same time, the difference is large enough to prevent the vibration of the scanner cantilever in the two directions from being coupled.

[0052] Therefore, the difference satisfies the condition that the vibration of the scanner cantilever in the horizontal direction and in the vertical direction will not be coupled when the barrel-shaped piezoelectric actuator 100 is driven to perform Lissajous scanning.

[0053] Generally, the difference is in the range of 10 Hz to 12 KHz. Further preferably, the difference is in the range of 1 KHz to 10 KHz. The value of the V-order natural frequency of the scanner cantilever in the horizontal direction is selected, as long as the difference satisfies the condition that the scanner cantilever has a large enough amplitude when the piezoelectric actuator is driven to perform Lissajous scanning, and the vibration of the scanner cantilever in the horizontal direction and in the vertical direction will not be coupled. For those skilled in the art, numerical selection according to the above description is a routine technical means in the art.

[0054] The support plate 200 and the barrel-shaped piezoelectric actuator 100 have a coincident part in the front-back direction, and the support plate 200 and the optical fiber 300 cantilever can be almost completely hidden in the through hole of the barrel-shaped piezoelectric actuator 100 and the base 400, greatly reducing the length of the optical fiber scanner in the front-back direction and the volume of the scanner.

[0055] Preferably, the natural frequency of the barrel-shaped piezoelectric actuator 100 in the first direction and the natural frequency of the same order in the second direction are the same or similar. Here, the barrel-shaped piezoelectric actuator 100 refers to the barrel-shaped piezoelectric actuator 100 itself, and does not include the support plate 200 or other components such as the optical fiber 300. The barrel-shaped piezoelectric actuator 100 that meets such requirements is a regular-shaped and rotationally-symmetric piezoelectric actuator, which has low processing difficulty, easy-to-control processing error, and high yield. For example, a circular tube type piezoelectric actuator, a square tube type piezoelectric actuator.

[0056] The optical fiber 300 is fixed in a cantilever support manner on the upper surface or lower surface of the support plate 200 or inside the support plate 200. The cantilever support refers to the part of the front end of the optical fiber 300 beyond the front end of the support plate 200 constituting the optical fiber 300 cantilever, and the part of the optical fiber 300 located at the rear side of the optical fiber 300 cantilever is fixedly connected with the support plate 200. As an embodiment in which the optical fiber 300 is arranged inside the support plate 200, a mounting hole for accommodating the optical fiber 300 is arranged in the body of the support plate 200, and the optical fiber 300 is fixed in a cantilever support manner in the mounting hole.

[0057] As an example of the cylindrical piezoelectric actuator 100:

[0058] As shown in Figure 4 , the circular tube type piezoelectric actuator has a circular tube type body as a whole, the axis of the body is arranged in the front-rear direction, the rear end of the body is fixedly connected with the base 400, and the front part of the body is connected with the rear end of the support plate 200.

[0059] The driving mode of the circular tube type body can be a piezoelectric sheet, or the body itself can be a piezoelectric material, and driving electrodes are arranged at corresponding positions of the inner and outer surfaces of the circular tube type piezoelectric actuator. The structure of the circular tube type piezoelectric actuator, and the structure of arranging piezoelectric sheets or driving electrodes, etc. all belong to conventional technical means in the art.

[0060] As shown in Figure 5 , the square tube type piezoelectric actuator has a square tube type body as a whole, which can be a square cross section profile or a rectangular cross section profile. The axis of the body is arranged in the front-rear direction, the rear end of the tube type body is fixedly connected with the base 400, and the front part of the tube type body is connected with the rear end of the support plate 200.

[0061] The driving mode of the square tube type body can be a piezoelectric sheet, or the body itself can be a piezoelectric material, and driving electrodes are arranged at corresponding positions of the inner and outer surfaces of the square tube type piezoelectric actuator. The structure of the square tube type piezoelectric actuator, and the structure of arranging piezoelectric sheets or driving electrodes, etc. all belong to conventional technical means in the art.

[0062] Embodiment 2:

[0063] As shown in Figure 1 , Figure 2 , Figure 3 , a small size Lissajous fiber scanner includes a base 400, a cylindrical piezoelectric actuator 100, a sheet type piezoelectric actuator 200 and an optical fiber 300, the cylindrical piezoelectric actuator 100 is a one-dimensional scanning piezoelectric actuator,

[0064] The fixed end of the cylindrical piezoelectric actuator 100 is fixedly connected with the base 400 to be supported by the base 400, the cylindrical piezoelectric actuator 100 has a first through hole 101 penetrating through the cylindrical piezoelectric actuator 100 along the axial direction, and the base 400 has a second through hole 401 communicating with the first through hole 101;

[0065] The free end of the cylindrical piezoelectric actuator 100 vibrates in the first direction, the free end of the cylindrical piezoelectric actuator 100 is the rear end, the fixed end of the cylindrical piezoelectric actuator 100 is the front end, the first direction is the left-right direction, the natural frequency of the cylindrical piezoelectric actuator 100 in the left-right direction is the same as or close to the natural frequency of the cylindrical piezoelectric actuator 100 in the vertical direction,

[0066] The sheet piezoelectric actuator 200 is arranged in the first through hole 101, the sheet piezoelectric actuator 200 is arranged in the direction parallel to the horizontal plane, the rear end of the sheet piezoelectric actuator 200 is fixedly connected with the free end of the cylindrical piezoelectric actuator 100, the front end of the sheet piezoelectric actuator 200 is located in the first through hole 101 or in the second through hole 401, the length of the sheet piezoelectric actuator 200 can be set according to the actual working condition requirement and is not limited, the front end of the sheet piezoelectric actuator 200 vibrates in the vertical direction, and the optical fiber 300 is fixedly arranged at the front end of the sheet piezoelectric actuator 200 in a cantilever support mode;

[0067] The part of the front end of the sheet piezoelectric actuator 200 fixedly connected with the cylindrical piezoelectric actuator 100 is driven by the cylindrical piezoelectric actuator 100 and itself to vibrate in two dimensions in the first through hole 101 or in the first through hole 101 and the second through hole 401, the hole diameters of the first through hole 101 and the second through hole 401 are set to be not less than the swing range of the sheet piezoelectric actuator 200 and the optical fiber 300, that is, the sheet piezoelectric actuator 200 and the optical fiber 300 will not contact the hole wall of the first through hole 101 or the hole wall of the second through hole 401 of the cylindrical piezoelectric actuator 100 in the scanning process,

[0068] The cylindrical piezoelectric actuator 100, the sheet piezoelectric actuator 200 and the optical fiber 300 constitute a scanner cantilever, the sheet piezoelectric actuator 200 makes the natural frequency of the scanner cantilever in the horizontal direction greater than the same order natural frequency of the scanner cantilever in the vertical direction, and makes the scanner cantilever in the vertical direction closest to the difference value between a certain order natural frequency and the V order natural frequency in the horizontal direction, V is an integer greater than or equal to 1.

[0069] The scanner cantilever has a first-order natural frequency, a second-order natural frequency, a third-order natural frequency, and an N-order natural frequency in the vertical direction, wherein the natural frequency of a certain order (for example, U-order, U is an integer greater than or equal to two) is closest to the V-order natural frequency of the scanner cantilever in the horizontal direction (V is less than U), and the closer the driving frequencies of the two directions in the Lissajous scanning are, the closer the uniformity (density) of the scanning grid in the two directions is, and the more the number of points is, and theoretically the closer the driving frequencies of the two directions are, the better, but the closer the natural frequencies of the scanner cantilever used in the two directions are, the more obvious the coupling effect is, and therefore the application adjusts the shape and / or size parameters of the sheet-shaped piezoelectric actuating part 200, so that the natural frequencies of the scanner cantilever used in the two directions are close enough to ensure good scanning effect and have a uniform and dense scanning grid, and at the same time have a sufficient difference, so that the vibration of the scanner cantilever in the two directions does not produce coupling.

[0070] Therefore, the difference satisfies that when the cylindrical piezoelectric actuating part 100 is driven by the driving signal to perform Lissajous scanning, the vibration of the scanner cantilever in the horizontal direction and in the vertical direction does not produce coupling.

[0071] Generally, the difference is in the range of 10 Hz to 12 KHz. Further preferably, the difference is in the range of 1 KHz to 10 KHz. The value is selected according to the selected V-order natural frequency of the scanner cantilever in the horizontal direction, as long as the difference satisfies that the scanner cantilever has sufficient amplitude when the piezoelectric actuating part is driven to perform Lissajous scanning, and the vibration of the scanner cantilever in the horizontal direction and in the vertical direction does not produce coupling. For those skilled in the art, numerical selection according to the above description is a conventional technical means in the art.

[0072] The sheet-shaped piezoelectric actuating part 200 and the cylindrical piezoelectric actuating part 100 have a coincident part in the front-rear direction, and the sheet-shaped piezoelectric actuating part 200 and the optical fiber 300 cantilever can be almost completely hidden in the through hole of the cylindrical piezoelectric actuating part 100 and the base 400, greatly reducing the length of the optical fiber scanner in the front-rear direction and reducing the volume of the scanner.

[0073] Preferably, the natural frequency of the cylindrical piezoelectric actuating part 100 in the left-right direction is the same as or close to the same-order natural frequency in the vertical direction. The cylindrical piezoelectric actuating part 100 referred to here refers to the cylindrical piezoelectric actuating part 100 itself, and does not include the sheet-shaped piezoelectric actuating part 200 or other components such as the optical fiber 300. The cylindrical piezoelectric actuating part 100 that meets such requirements is a regular-shaped, rotationally-symmetric piezoelectric actuator, which has low processing difficulty, easy-to-control processing error, and high yield. For example, a circular tube type piezoelectric actuator, a square tube type piezoelectric actuator.

[0074] Optionally, the sheet piezoelectric actuator 200 is a single piezoelectric sheet actuator or a double piezoelectric sheet actuator. The sheet piezoelectric actuator 200 is also a conventional actuator, which is easy to process. Through the combination of two easy-to-process components, the present application can obtain a scanner suitable for Lissajous scanning and having guaranteed anti-coupling effect, which has low processing difficulty and high yield compared with the existing Lissajous scanner.

[0075] The optical fiber 300 is fixed on the upper surface or lower surface of the sheet piezoelectric actuator 200 or inside the sheet piezoelectric actuator 200 in a cantilever support manner. The cantilever support refers to that the front end of the optical fiber 300 beyond the front end of the sheet piezoelectric actuator 200 constitutes a cantilever of the optical fiber 300, and the part of the optical fiber 300 behind the cantilever is fixedly connected with the sheet piezoelectric actuator 200. As an embodiment in which the optical fiber 300 is arranged inside the sheet piezoelectric actuator 200, a mounting hole for accommodating the optical fiber 300 is arranged in the body of the sheet piezoelectric actuator 200, and the optical fiber 300 is fixed in the mounting hole in a cantilever support manner.

[0076] As an example of the cylindrical piezoelectric actuator 100:

[0077] As shown in Figure 4 , the circular tube type actuator has a circular tube type body as a whole, and the axis of the body is arranged in the front-rear direction.

[0078] The driving mode of the circular tube type body can be a piezoelectric sheet, or the body itself can be a piezoelectric material, and driving electrodes are arranged at the corresponding positions of the inner and outer surfaces. The structure of the circular tube type actuator, and the structure of the piezoelectric sheet or driving electrode arranged thereon all belong to the conventional technical means in the field.

[0079] As shown in Figure 5 , the square tube type actuator has a square tube type body as a whole, and the square tube type can be a square cross-section profile or a rectangular cross-section profile. The axis of the body is arranged in the front-rear direction.

[0080] The driving mode of the square tube type body can be a piezoelectric sheet, or the body itself can be a piezoelectric material, and driving electrodes are arranged at the corresponding positions of the inner and outer surfaces. The structure of the square tube type actuator, and the structure of the piezoelectric sheet or driving electrode arranged thereon all belong to the conventional technical means in the field.

[0081] It should be noted that the foregoing examples have been provided merely for the purpose of explanation and are in no way to be construed as limiting of the present application. While the application has been described with reference to preferred embodiments and illustrative examples, the words which have been used herein are words of description, and thus are used in a descriptive sense and not restrictive. The application is defined by the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word comprising does not exclude other elements or steps. The words first, second and third do not imply any ordering. The word at least is used to mean one or more of a certain feature or parameter. The indefinite articles "a" and "an" shall not be construed as limiting the claim on the basis of the specific number of features or parameters. The word "comprising" does not exclude the presence of elements or steps other than those listed in a claim. The word "a" preceding the commencement of the claims does not exclude the presence of more than one element having the identified function. The application encompasses any new feature or combination of features disclosed herein or any new method or process combination of steps disclosed herein or any new combination of features or steps disclosed herein.

[0082] All features disclosed in this specification, unless expressed otherwise, can be combined in any combination.

[0083] Any feature described in this specification, unless expressed otherwise, can be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. That is, unless expressly stated otherwise, each feature is one of a number of equivalent or similar features.

[0084] This application is not limited to the specific embodiments described herein. This application extends to any novel one, or any novel combination, of the features disclosed in this specification, and to any novel method or process steps, or any novel combination of steps, disclosed in this specification.

Claims

1. A small size Lissajous fiber scanner characterized by, The application relates to a scanner cantilever comprising a cylindrical piezoelectric actuator, a support plate and an optical fiber. The fixed end of the cylindrical piezoelectric actuator is fixedly connected with a base to be supported by the base, the cylindrical piezoelectric actuator has a first through hole penetrating the cylindrical piezoelectric actuator along the axial direction, and the base has a second through hole communicating with the first through hole. The free end of the cylindrical piezoelectric actuator simultaneously vibrates along a first direction and a second direction, the first direction is perpendicular to the second direction, the free end of the cylindrical piezoelectric actuator is the rear end, the fixed end of the cylindrical piezoelectric actuator is the front end, the first direction is the left-right direction, and the second direction is the vertical direction. The support plate is arranged in the first through hole and is arranged along the horizontal direction, the rear end of the support plate is fixedly connected with the free end of the cylindrical piezoelectric actuator, the front end of the support plate is located in the first through hole or the second through hole, and the optical fiber is fixedly arranged on the front end of the support plate in a cantilever supporting mode. The part of the front end of the support plate fixedly connected with the cylindrical piezoelectric actuator is driven to vibrate in two dimensions by the cylindrical piezoelectric actuator in the first through hole or the first through hole and the second through hole, and the aperture of the first through hole and the second through hole is not less than the swing range of the support plate and the optical fiber. The cylindrical piezoelectric actuator, the support plate and the optical fiber constitute the scanner cantilever, the support plate makes the inherent frequency of the scanner cantilever in the horizontal direction greater than the same order inherent frequency of the scanner cantilever in the vertical direction, and makes the scanner cantilever have a difference between the certain order inherent frequency closest to the V order inherent frequency in the horizontal direction and the V order inherent frequency in the vertical direction, and V is an integer greater than or equal to 1.

2. A small size Lissajous fiber scanner as claimed in claim 1, characterized in that, The difference satisfies that when the cylindrical piezoelectric actuator is driven to perform Lissajous scanning under the driving of the driving signal, the vibration of the scanner cantilever in the horizontal direction and in the vertical direction will not be coupled.

3. A small size Lissajous fiber scanner as claimed in claim 1 or 2, characterized in that, The difference ranges from 10 Hz to 12 KHz.

4. A small size Lissajous fiber scanner as claimed in claim 1 or 2, characterized in that, The difference ranges from 1 KHz to 10 KHz.

5. A small size Lissajous fiber scanner as claimed in claim 1, characterized in that, The inherent frequency of the cylindrical piezoelectric actuator in the first direction is the same as or close to the same order inherent frequency in the second direction.

6. A small size Lissajous fiber scanner as claimed in claim 1, characterized in that, The optical fiber is fixedly arranged on the upper surface or the lower surface of the support plate in a cantilever supporting mode or is arranged in the interior of the support plate.

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