A dual-drive Lissajous fiber optic scanner
By adjusting the inherent frequency difference of the Lissajous fiber optic scanner with dual drive units, the vibration coupling problem of the Lissajous scanner was solved, improving processing efficiency and yield, and achieving a uniform and dense scanning effect.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- CHENGDU IDEALSEE TECH
- Filing Date
- 2024-12-30
- Publication Date
- 2026-08-04
AI Technical Summary
Existing Lissajous scanners are prone to vibration coupling effects when the natural frequencies used in two directions are close, resulting in scanning trajectory distortion and making it difficult to guarantee processing accuracy and yield.
A dual-drive Lissajous fiber optic scanner is designed. By adjusting the structural and dimensional parameters of the piezoelectric cylindrical body and the sheet-like piezoelectric actuator, the natural frequency difference between the combined part in the horizontal and vertical directions is made within the range of 10Hz to 12KHz, thus avoiding vibration coupling and reducing the processing difficulty and precision requirements.
It achieves a uniform and dense scanning mesh in two directions, avoids vibration coupling, and improves processing efficiency and yield.
Smart Images
Figure CN224594922U_ABST
Abstract
Description
[0001] This application is a divisional application of Chinese Patent Application No. 2024232650125, filed with the Chinese Patent Office on December 30, 2024, entitled "A Dual-Drive Lissajous Fiber Optic Scanner", the entire contents of which are incorporated herein by reference. Technical Field
[0002] This application relates to the field of fiber optic scanner structure technology, and in particular to a dual-drive Lissajous fiber optic scanner. Background Technology
[0003] A fiber optic scanner is a display technology that uses a scanning driver to control the oscillation of an optical fiber while simultaneously emitting light. It is primarily used in fiber optic scanning display technology, fiber optic scanning endoscopy technology, and fiber optic scanning radar. When applied to image display, fiber optic scanners produce images with sharp, saturated colors, high contrast, high brightness, and a very small structural size.
[0004] Fiber optic scanners utilize the principle of mechanical resonance to enable a large scanning range for the fiber optic cantilever. Scanning methods of the scanning driver can be categorized into helical scanning, grid scanning, and Lissajous scanning. Lissajous scanning micro-piezoelectric scanning devices typically have driving sections in two directions, driving the scanning device to vibrate simultaneously in both directions. In Lissajous scanning, the closer the driving frequencies in the two directions, the closer the uniformity (density) of the scanning grid in both directions. Theoretically, the closer the driving frequencies in these two directions, the better. However, the closer the natural frequencies used by the scanner in the two directions, the more pronounced the vibration coupling effect becomes, which degrades the scanning trajectory, causing uncontrolled components in the scanning trajectory and resulting in image distortion that is difficult to completely eliminate through post-processing. Therefore, the natural frequencies used by the Lissajous scanner in the two directions should ideally have a precise difference range, avoiding both excessively small differences that cause coupling effects and excessively large differences that lead to unsatisfactory uniformity.
[0005] The manufacturing of Lissajous scanners, which utilize the inherent frequencies in both directions with precise differences, requires extremely high processing accuracy, making it difficult to guarantee both the cost of processing equipment and the yield rate. Utility Model Content
[0006] This application provides a dual-drive Lissajous fiber optic scanner to reduce processing difficulty and improve processing yield.
[0007] To achieve the aforementioned objectives, this application provides a dual-drive Lissajous fiber optic scanner, comprising a cylindrical piezoelectric actuator, a sheet-like piezoelectric actuator fixedly connected to the cylindrical piezoelectric actuator, and an optical fiber fixedly mounted on the sheet-like piezoelectric actuator in a cantilevered manner.
[0008] The cylindrical piezoelectric actuator includes a piezoelectric material cylindrical body. With the axial extension direction of the piezoelectric material cylindrical body as the front-to-back direction, the rear end of the piezoelectric material cylindrical body is fixedly connected to a base for support. At least one of the left and right sides of the piezoelectric material cylindrical body has a first inner electrode and a first outer electrode respectively disposed on their inner and outer surfaces. The portion of the piezoelectric material cylindrical body located between the first inner electrode and the corresponding first outer electrode is polarized along its thickness direction. The first inner electrode and the corresponding first outer electrode drive the piezoelectric material located between them to extend and retract in the front-to-back direction, and drive the front end of the piezoelectric material cylindrical body to vibrate left and right in the horizontal direction.
[0009] A sheet-shaped piezoelectric actuator is arranged parallel to the horizontal plane, located on the front side of the piezoelectric material cylindrical body. Its rear end is attached to the upper or lower surface of the piezoelectric material cylindrical body and fixedly connected to it. The surface of the piezoelectric material cylindrical body used to attach the sheet-shaped piezoelectric actuator is planar. The front end of the sheet-shaped piezoelectric actuator vibrates vertically. An optical fiber is fixedly mounted to the front end of the sheet-shaped piezoelectric actuator in a cantilevered manner. The portion of the sheet-shaped piezoelectric actuator attached to the piezoelectric material cylindrical body and the portion of the piezoelectric material cylindrical body that overlaps with this portion of the sheet-shaped piezoelectric actuator in the front-rear direction form an overlapping portion. The sheet-shaped piezoelectric actuator and the overlapping portion cause the natural frequency of the combined portion (the piezoelectric material cylindrical body, the sheet-shaped piezoelectric actuator, and the optical fiber) in the horizontal direction to be greater than the same-order natural frequency in the vertical direction. Furthermore, the U-order natural frequency, which is closest to the V-order natural frequency in the horizontal direction, has a difference from the V-order natural frequency in the horizontal direction.
[0010] Optionally, V is an integer greater than or equal to 1, and U is an integer greater than V.
[0011] Specifically, by adjusting the shape and / or size parameters of the sheet-like piezoelectric actuator and the overlapping part, the natural frequencies of the combined part used in both directions are simultaneously close enough to ensure good scanning effect and a uniform and dense scanning grid; at the same time, they have a sufficient difference so that the vibration of the combined part in the two directions will not couple.
[0012] Preferably, the piezoelectric material cylindrical body has the same natural frequency in the horizontal direction and the same natural frequency in the vertical direction, and its outer contour is square. Inside, there is a central hole with a square or circular contour, coaxial with the outer contour. However, this is not a limitation; for example, its outer surface can be approximately cylindrical, and several planes can be arranged with rotational symmetry, one of which is used to mount a sheet-like piezoelectric actuator.
[0013] The difference value ensures that when the combined unit performs a Lissajous scan under the drive signal, the vibrations of the combined unit in the horizontal direction and the vibrations in the vertical direction do not couple. Generally, the difference value ranges from 10Hz to 12kHz. More preferably, the difference value ranges from 1kHz to 10kHz. Specifically, it is selected based on the V-order natural frequency of the scanner arm in the horizontal direction, as long as the difference value satisfies the requirement that the scanner arm has sufficient amplitude when the piezoelectric actuator performs a Lissajous scan under drive, and that the vibrations of the scanner arm in the horizontal and vertical directions do not couple. For those skilled in the art, selecting values based on the above description is a conventional technique in the field.
[0014] Optionally, the sheet-like piezoelectric actuator is a single piezoelectric actuator or a dual piezoelectric actuator.
[0015] Optionally, a first inner electrode and a first outer electrode are respectively provided on the inner and outer surfaces of either the left or right sides of the piezoelectric material cylindrical body. The portion of the piezoelectric material cylindrical body located between the first inner electrode and the corresponding first outer electrode is polarized along the thickness direction. The piezoelectric material located between the first inner electrode and the corresponding first outer electrode is driven to extend and retract in the front-back direction, driving the front end of the cylindrical body to vibrate left and right in the horizontal direction. The number of first inner electrodes or first outer electrodes can be one, two, or more.
[0016] Alternatively, the inner and outer surfaces of the left and right sides of the piezoelectric cylindrical body are respectively provided with corresponding first inner electrodes and first outer electrodes. The portion of the piezoelectric cylindrical body located between the first inner electrode and the corresponding first outer electrode is polarized along the thickness direction. The piezoelectric material located between the first inner electrode and the corresponding first outer electrode is driven to extend and retract in the front-back direction, while the piezoelectric materials on the left and right sides extend and retract synchronously in opposite directions with equal length, driving the front end of the cylindrical body to vibrate left and right in the horizontal direction. The number of first inner electrodes or first outer electrodes can be one, two, or more.
[0017] In a further preferred embodiment, when the inner and outer surfaces of the left and right sides of the piezoelectric material cylindrical body are respectively provided with a first inner electrode and a corresponding first outer electrode, the first inner electrodes on the left and right sides of the piezoelectric material cylindrical body are symmetrically arranged so as to drive the piezoelectric material cylindrical body to vibrate accurately in the horizontal direction without generating a vertical displacement component.
[0018] One or more technical solutions in this application have at least the following technical effects or advantages:
[0019] This application eliminates the need for the piezoelectric actuator of the Lissajous scanner to have a specific difference in its natural frequency in the two driving directions, thus avoiding coupling of vibrations in the two driving directions and reducing the requirements for processing difficulty and precision. More preferably, this application allows the piezoelectric material cylindrical body to have the same or similar natural frequencies in the two driving directions, and allows the piezoelectric material cylindrical body itself to be a rotationally symmetric structure. This further reduces the processing difficulty of the piezoelectric actuator of the Lissajous scanner, resulting in a significant improvement in processing efficiency and yield. Attached Figure Description
[0020] Figure 1 This is a schematic diagram of the structure of this utility model;
[0021] Figure 2 This is a schematic diagram of the overlapping part structure in the front-to-back direction. Detailed Implementation
[0022] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.
[0023] Example:
[0024] Combination Figure 1 , Figure 2 As shown, a dual-drive Lissajous fiber optic scanner includes a cylindrical piezoelectric actuator, a sheet-like piezoelectric actuator 103 fixedly connected to the cylindrical piezoelectric actuator, and an optical fiber 104 fixedly mounted on the sheet-like piezoelectric actuator 103 in a cantilevered manner.
[0025] The cylindrical piezoelectric actuator includes a piezoelectric material cylindrical body 100. With the axial extension direction of the piezoelectric material cylindrical body 100 as the front-to-back direction, the rear end of the piezoelectric material cylindrical body 100 is fixedly connected to a base 200 for support. At least one of the left and right sides of the piezoelectric material cylindrical body 100 has a first inner electrode 1011 and a first outer electrode 1012 respectively disposed on their inner and outer surfaces. The portion of the piezoelectric material cylindrical body 100 located between the first inner electrode 1011 and the corresponding first outer electrode 1012 is polarized along its thickness direction. The first inner electrode 1011 and the corresponding first outer electrode 1012 drive the piezoelectric material located between them to extend and retract in the front-to-back direction, and drive the front end of the piezoelectric material cylindrical body 100 to vibrate left and right in the horizontal direction.
[0026] A sheet-shaped piezoelectric actuator 103 is arranged parallel to the horizontal plane, located on the front side of the piezoelectric material cylindrical body 100. Its rear end is attached to the upper or lower surface of the piezoelectric material cylindrical body 100 and fixedly connected to it. The surface of the piezoelectric material cylindrical body 100 used to attach the sheet-shaped piezoelectric actuator 103 is planar. The front end of the sheet-shaped piezoelectric actuator 103 vibrates vertically. An optical fiber 104 is fixedly mounted to the front end of the sheet-shaped piezoelectric actuator 103 in a cantilevered support manner. The sheet-shaped piezoelectric actuator 103 is attached to the piezoelectric material cylindrical body. A portion of the body 100 overlaps with a portion of the piezoelectric material cylindrical body 100 that coincides with the sheet-like piezoelectric actuator 103 in the front-rear direction, forming an overlapping portion 105. The sheet-like piezoelectric actuator 103 and the overlapping portion 105 cause the natural frequency in the horizontal direction of the assembly consisting of the piezoelectric material cylindrical body 100, the sheet-like piezoelectric actuator 103, and the optical fiber 104 to be greater than the same-order natural frequency in the vertical direction. Furthermore, the U-order natural frequency, which is closest to its V-order natural frequency in the vertical direction, has a difference from the V-order natural frequency in the horizontal direction. In this embodiment, V-order is first-order, and U-order is second-order.
[0027] Of course, this is only the parameter selection for this embodiment. In other embodiments with similar structure types to this embodiment, V can also be an integer greater than 1, and U can be an integer greater than V.
[0028] Specifically, by adjusting the shape and / or size parameters of the sheet-like piezoelectric actuator 103 and the overlapping part 105, the natural frequencies of the combined part used in both directions are simultaneously close enough to ensure good scanning effect and have a uniform and dense scanning grid; at the same time, they have a sufficient difference so that the vibration of the combined part in both directions will not couple.
[0029] Preferably, the piezoelectric cylindrical body 100 has the same natural frequency in the horizontal direction and the same natural frequency in the vertical direction. Its outer contour is square, and its interior has a central hole with a square or circular contour that is coaxial with the outer contour. Of course, there are no restrictions on this. For example, its outer surface is roughly cylindrical, and several planes are arranged rotationally symmetrically, one of which is used to mount the sheet-like piezoelectric actuator 103.
[0030] The difference value ensures that when the combined unit performs a Lissajous scan under the drive signal, the vibrations of the combined unit in the horizontal direction and the vibrations in the vertical direction do not couple. Generally, the difference value ranges from 10Hz to 12kHz. More preferably, the difference value ranges from 1kHz to 10kHz. Specifically, it is selected based on the V-order natural frequency of the scanner arm in the horizontal direction, as long as the difference value satisfies the requirement that the scanner arm has sufficient amplitude when the piezoelectric actuator performs a Lissajous scan under drive, and that the vibrations of the scanner arm in the horizontal and vertical directions do not couple. For those skilled in the art, selecting values based on the above description is a conventional technique in the field.
[0031] Optionally, the sheet-shaped piezoelectric actuator 103 is a single piezoelectric actuator or a dual piezoelectric actuator.
[0032] Optionally, a first inner electrode 1011 and a first outer electrode 1012 are respectively provided on the inner and outer surfaces of either the left or right sides of the piezoelectric material cylindrical body 100. The portion of the piezoelectric material cylindrical body 100 located between the first inner electrode 1011 and the corresponding first outer electrode 1012 is polarized along the thickness direction. The piezoelectric material located between the first inner electrode 1011 and the corresponding first outer electrode 1012 is driven to extend and retract in the front-back direction, driving the front end of the cylindrical body 100 to vibrate left and right in the horizontal direction. The number of first inner electrodes 1011 or first outer electrodes 1012 can be one, two, or more.
[0033] Alternatively, the inner and outer surfaces of the left and right sides of the piezoelectric material cylindrical body 100 are respectively provided with correspondingly matched first inner electrodes 1011 and first outer electrodes 1012. The portion of the piezoelectric material cylindrical body 100 located between the first inner electrode 1011 and the corresponding first outer electrode 1012 is polarized along the thickness direction. The piezoelectric material located between the first inner electrode 1011 and the corresponding first outer electrode 1012 is driven to extend and retract in the front-back direction, and the piezoelectric materials on the left and right sides extend and retract synchronously in opposite directions with equal length, driving the front end of the cylindrical body 100 to vibrate left and right in the horizontal direction. The number of first inner electrodes 1011 or first outer electrodes 1012 can be one, two, or more.
[0034] More preferably, when the inner and outer surfaces of the piezoelectric material cylindrical body 100 on both sides are respectively provided with a first inner electrode 1011 and a corresponding first outer electrode 1012, the first inner electrodes 1011 on both sides of the piezoelectric material cylindrical body 100 are symmetrically arranged so as to drive the piezoelectric material cylindrical body 100 to vibrate accurately in the horizontal direction without generating a vertical displacement component.
[0035] This application eliminates the need for the piezoelectric actuator of the Lissajous scanner to have a specific difference in its natural frequency in the two driving directions, thus avoiding coupling of vibrations in the two driving directions and reducing the processing difficulty and accuracy requirements. More preferably, this application allows the piezoelectric material cylindrical body 100 to have the same or similar natural frequencies in the two driving directions, and allows the piezoelectric material cylindrical body 100 itself to be a rotationally symmetric structure. This further reduces the processing difficulty of the piezoelectric actuator of the Lissajous scanner, resulting in a significant improvement in processing efficiency and yield.
[0036] It should be noted that the above embodiments are illustrative of this application and not limiting of it, and that those skilled in the art can devise alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses should not be construed as limiting the claims. The words “comprising” or “including” do not exclude the presence of elements or steps not listed in the claims. The words “a” or “an” preceding an element do not exclude the presence of a plurality of such elements. The use of the words first, second, and third, etc., does not indicate any order and these words can be interpreted as names.
[0037] All features disclosed in this specification, except for mutually exclusive features, can be combined in any way.
[0038] Any feature disclosed in this specification (including any appended claims, abstract, and drawings) may be replaced by other equivalent or similar features, unless specifically stated otherwise. That is, unless specifically stated otherwise, each feature is merely one example of a series of equivalent or similar features.
Claims
1. A dual drive Lissajous fiber scanner, characterized in that, It includes a cylindrical piezoelectric actuator, a sheet-shaped piezoelectric actuator fixedly connected to the cylindrical piezoelectric actuator, and an optical fiber fixedly mounted on the sheet-shaped piezoelectric actuator in a cantilever support manner. The cylindrical piezoelectric actuator includes a piezoelectric material cylindrical body. With the axial extension direction of the piezoelectric material cylindrical body as the front-to-back direction, the rear end of the piezoelectric material cylindrical body is fixedly connected to a base for support. At least one of the left and right sides of the piezoelectric material cylindrical body has a first inner electrode and a first outer electrode respectively disposed on their inner and outer surfaces. The portion of the piezoelectric material cylindrical body located between the first inner electrode and the corresponding first outer electrode is polarized along its thickness direction. The first inner electrode and the corresponding first outer electrode drive the piezoelectric material located between them to extend and retract in the front-to-back direction, and drive the front end of the piezoelectric material cylindrical body to vibrate left and right in the horizontal direction. A sheet-shaped piezoelectric actuator is arranged parallel to the horizontal plane, located on the front side of the piezoelectric material cylindrical body. Its rear end is attached to the upper or lower surface of the piezoelectric material cylindrical body and fixedly connected to it. The surface of the piezoelectric material cylindrical body used to attach the sheet-shaped piezoelectric actuator is planar. The front end of the sheet-shaped piezoelectric actuator vibrates vertically. An optical fiber is fixedly mounted to the front end of the sheet-shaped piezoelectric actuator in a cantilevered manner. The portion of the sheet-shaped piezoelectric actuator attached to the piezoelectric material cylindrical body and the portion of the piezoelectric material cylindrical body that overlaps with this portion of the sheet-shaped piezoelectric actuator in the front-rear direction form an overlapping portion. The sheet-shaped piezoelectric actuator and the overlapping portion cause the natural frequency of the combined portion (the piezoelectric material cylindrical body, the sheet-shaped piezoelectric actuator, and the optical fiber) in the horizontal direction to be greater than the same-order natural frequency in the vertical direction. Furthermore, the U-order natural frequency, which is closest to the V-order natural frequency in the horizontal direction, has a difference from the V-order natural frequency in the horizontal direction.
2. A dual drive Lissajous fiber scanner as claimed in claim 1, characterized in that V is an integer greater than or equal to 1, and U is an integer greater than V.
3. A dual drive Lissajous fiber scanner as claimed in claim 1 or 2, characterized in that The difference ensures that when the assembly performs a Lissajous scan under the drive signal, the vibrations of the assembly in the horizontal direction and the vibrations in the vertical direction will not couple.
4. A dual drive Lissajous fiber scanner as claimed in claim 3, characterized in that, The difference range is 10Hz to 12KHz.
5. A dual drive Lissajous fiber scanner as claimed in claim 4, characterized in that, The difference range is 1kHz to 10kHz.
6. A dual drive Lissajous fiber scanner as claimed in claim 1 or 2, characterized in that The aforementioned sheet-shaped piezoelectric actuator is a single piezoelectric actuator or a dual piezoelectric actuator.
7. A dual drive Lissajous fiber scanner as claimed in claim 1 or 2, characterized in that The inner and outer surfaces of either the left or right sides of the piezoelectric cylindrical body are respectively provided with a first inner electrode and a first outer electrode that are respectively matched. The portion of the piezoelectric cylindrical body located between the first inner electrode and the corresponding first outer electrode is polarized along the thickness direction.
8. A dual drive Lissajous fiber scanner as claimed in claim 1 or 2, characterized in that, The inner and outer surfaces of the left and right sides of the piezoelectric cylindrical body are respectively provided with corresponding first inner electrodes and first outer electrodes. The portion of the piezoelectric cylindrical body located between the first inner electrode and the corresponding first outer electrode is polarized along the thickness direction.
9. A dual drive Lissajous fiber scanner as claimed in claim 8, characterized in that The first inner electrodes on the left and right sides of the piezoelectric cylindrical body are symmetrically arranged.