A lissajous scanner
By introducing a sheet-like piezoelectric actuator and an overlapping part into the Lissajous scanner, the natural frequency difference was adjusted, the vibration coupling problem was solved, the ease of processing and yield were improved, and a uniform and dense scanning effect was achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHENGDU IDEALSEE TECH
- Filing Date
- 2024-12-30
- Publication Date
- 2026-06-30
Smart Images
Figure CN122307905A_ABST
Abstract
Description
[0001] This application is a divisional application of Chinese Patent Application No. 2024119612037, filed with the Chinese Patent Office on December 30, 2024, entitled “A Lissajous 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 more particularly to a Lissajous 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. Summary of the Invention
[0006] This application provides a Lissajous scanner to reduce processing difficulty and improve processing yield.
[0007] To achieve the aforementioned objectives, this application provides a Lissajous scanner, including a base, a first piezoelectric actuator, a sheet-like piezoelectric actuator, and an optical fiber. The first piezoelectric actuator is a one-dimensional scanning piezoelectric actuator. Its fixed end is fixedly connected to the base, and its free end vibrates along a first direction. The free end of the first piezoelectric actuator is the front end, and its fixed end is the rear end. The first direction is the left-right direction. The rear end of the sheet-like piezoelectric actuator is fixedly connected to the free end of the first piezoelectric actuator. The sheet-like piezoelectric actuator is arranged parallel to the horizontal plane. The first piezoelectric actuator has an overlapping portion in the front-to-back direction. The front end of the sheet piezoelectric actuator vibrates in the vertical direction. The optical fiber is fixedly mounted on the front end of the sheet piezoelectric actuator in a cantilever support manner. The first piezoelectric actuator, the sheet piezoelectric actuator, and the optical fiber constitute a scanner cantilever. The sheet piezoelectric actuator and the overlapping portion make the natural frequency of the scanner cantilever in the horizontal direction greater than its natural frequency of the same order in the vertical direction. Furthermore, the scanner cantilever has a difference between a certain natural frequency in the vertical direction that is closest to its natural frequency of order V in the horizontal direction and the natural frequency of order V in the horizontal direction, where V is an integer greater than or equal to 1.
[0008] The scanner cantilever has first-order, second-order, third-order, ... N-order natural frequencies in the vertical direction. Among them, there is a certain natural frequency (e.g., U-order, where U is an integer greater than or equal to two) that is closest to the V-order natural frequency of the scanner cantilever in the horizontal direction (V is less than U). In Lissajous scanning, the closer the driving frequencies in the two directions are, the closer the uniformity (density) of the scanning grid in the two directions will be, and the more points can be taken. Theoretically, the closer the driving frequencies in the two directions are, the better. However, the closer the natural frequencies used by the scanner cantilever in the two directions are, the more obvious the coupling effect will be. Therefore, this application uses the shape structure and / or size parameters of the sheet piezoelectric actuator and the overlapping part to make the natural frequencies of the scanner cantilever used in the two directions simultaneously satisfy the following: they are close enough to ensure good scanning effect and have a uniform and dense scanning grid, while also having a sufficient difference so that the vibration of the scanner cantilever in the two directions will not produce coupling.
[0009] Preferably, the natural frequency of the first piezoelectric actuator in the left-right direction is the same as or similar to its natural frequency in the vertical direction. Here, the first piezoelectric actuator refers to the first piezoelectric actuator itself, excluding sheet-shaped piezoelectric actuators and other components such as optical fibers. A first piezoelectric actuator meeting these requirements is a regularly shaped, rotationally symmetrical piezoelectric actuator, which is easy to manufacture, has easily controllable manufacturing errors, and a high yield rate. Examples include cylindrical piezoelectric actuators, square cylindrical piezoelectric actuators, cylindrical bar piezoelectric actuators, and square bar piezoelectric actuators. Sheet-shaped piezoelectric actuators are also conventional actuators with low manufacturing difficulty. This application, by combining two easily manufactured components, obtains a scanner suitable for Lissajous scanning with guaranteed anti-coupling effect, which is easier to manufacture and has a higher yield rate compared to existing Lissajous scanners.
[0010] Therefore, the difference satisfies the requirement that when the first piezoelectric actuator performs Lissajous scanning under the drive signal, the scanner cantilever has sufficient amplitude, and that the vibration of the scanner cantilever in the horizontal direction and in the vertical direction will not couple.
[0011] Generally, the difference ranges from 10Hz to 12kHz. More preferably, the difference ranges from 1kHz to 10kHz. Specifically, the difference is selected based on the V-order natural frequency of the scanner arm in the horizontal direction. The difference is sufficient to ensure that the scanner arm has sufficient amplitude when the piezoelectric actuator performs Lissajous scanning 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.
[0012] The optical fiber is fixedly mounted on the upper or lower surface of the support plate, or disposed inside the support plate, using a cantilever support method. The cantilever support refers to the portion of the optical fiber extending beyond the front end of the support plate forming an optical fiber cantilever, with the portion of the optical fiber located behind the cantilever fixedly connected to the support plate. In one embodiment where the optical fiber is disposed inside the support plate, the support plate itself has mounting holes for accommodating the optical fiber, and the optical fiber is fixedly mounted within these mounting holes using a cantilever support method.
[0013] The piezoelectric actuator includes a cylindrical piezoelectric actuator, a square tube piezoelectric actuator, a square bar piezoelectric actuator, or a round bar piezoelectric actuator.
[0014] Optionally, the sheet-like piezoelectric actuator is a single piezoelectric actuator or a dual piezoelectric actuator.
[0015] One or more technical solutions in this application have at least the following technical effects or advantages:
[0016] This application utilizes the adjustment of the shape and / or size parameters of the sheet piezoelectric actuator and the overlapping part to ensure that the natural frequencies of the scanner cantilever used in both directions are sufficiently close to guarantee good scanning effect and have a uniform and dense scanning grid, while also having sufficient difference so that the vibration of the scanner cantilever in both directions will not couple.
[0017] Since the natural frequencies of the first piezoelectric actuator in the left-right direction and in the vertical direction are the same or similar, the first piezoelectric actuator mentioned here refers to the first piezoelectric actuator itself, excluding sheet-like piezoelectric actuators and other components such as optical fibers. A first piezoelectric actuator that meets these requirements is a regularly shaped, rotationally symmetrical piezoelectric actuator, which is easy to manufacture, has easily controllable manufacturing errors, and a high yield rate. Attached Figure Description
[0018] Figure 1 This is a schematic diagram of the structure of the present invention;
[0019] Figure 2 This is a schematic diagram of the overlapping part structure;
[0020] Figure 3 This is a schematic diagram of a cylindrical piezoelectric actuator.
[0021] Figure 4 This is a schematic diagram of a square-shaped piezoelectric actuator;
[0022] Figure 5 This is a schematic diagram of a square rod-type piezoelectric actuator;
[0023] Figure 6 This is a schematic diagram of a cylindrical piezoelectric actuator. Detailed Implementation
[0024] 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.
[0025] like Figure 1As shown, a Lissajous scanner includes a base 400, a first piezoelectric actuator 100, a sheet-like piezoelectric actuator 200, and an optical fiber 300. The first piezoelectric actuator 100 is a one-dimensional scanning piezoelectric actuator. The fixed end of the first piezoelectric actuator 100 is fixedly connected to the base 400, and the free end of the first piezoelectric actuator 100 vibrates along a first direction. With the free end of the first piezoelectric actuator 100 as the front end and the fixed end of the first piezoelectric actuator 100 as the rear end, and the first direction as the left-right direction, the rear end of the sheet-like piezoelectric actuator 200 is fixedly connected to the free end of the first piezoelectric actuator 100. The sheet-like piezoelectric actuator 200 is arranged parallel to the horizontal plane, and the sheet-like piezoelectric actuator 200 and the first piezoelectric actuator 100 have an overlapping portion 500 in the front-back direction. Figure 2 As shown, the front end of the sheet piezoelectric actuator 200 vibrates in the vertical direction, and the optical fiber 300 is fixedly mounted on the front end of the sheet piezoelectric actuator 200 in a cantilever support manner. The first piezoelectric actuator 100, the sheet piezoelectric actuator 200, and the optical fiber 300 constitute a scanner cantilever. The sheet piezoelectric actuator 200 and the overlapping part 500 make the natural frequency of the scanner cantilever in the horizontal direction greater than its natural frequency of the same order in the vertical direction, and make a difference between a certain natural frequency of the scanner cantilever in the vertical direction that is closest to its natural frequency of V in the horizontal direction and the natural frequency of V in the horizontal direction, where V is an integer greater than or equal to 1.
[0026] The scanner cantilever has first-order, second-order, third-order, ... N-order natural frequencies in the vertical direction. Among them, there is a certain natural frequency (e.g., U-order, where U is an integer greater than or equal to two) that is closest to the V-order natural frequency of the scanner cantilever in the horizontal direction (V is less than U). In Lissajous scanning, the closer the driving frequencies in the two directions are, the closer the uniformity (density) of the scanning grid in the two directions will be, and the more points can be taken. Theoretically, the closer the driving frequencies in the two directions are, the better. However, the closer the natural frequencies used by the scanner cantilever in the two directions are, the more obvious the coupling effect will be. Therefore, this application uses the shape structure and / or size parameters of the sheet piezoelectric actuator 200 and the overlapping part 500 to make the natural frequencies of the scanner cantilever used in the two directions both close enough to ensure good scanning effect and have a uniform and dense scanning grid, and have enough difference so that the vibration of the scanner cantilever in the two directions will not produce coupling.
[0027] Preferably, the natural frequency of the first piezoelectric actuator 100 in the left-right direction is the same as or similar to its natural frequency in the vertical direction. Here, the first piezoelectric actuator 100 refers to the first piezoelectric actuator 100 itself, excluding the sheet-shaped piezoelectric actuator 200 and other components such as optical fibers. The first piezoelectric actuator 100 meeting these requirements is a regularly shaped, rotationally symmetrical piezoelectric actuator, which is easy to manufacture, has easily controllable manufacturing errors, and a high yield rate. Examples include cylindrical piezoelectric actuators, square cylindrical piezoelectric actuators, round bar piezoelectric actuators, and square bar piezoelectric actuators. The sheet-shaped piezoelectric actuator 200 is also a conventional actuator, with low manufacturing difficulty. This application, by combining two easily manufactured components, obtains a scanner suitable for Lissajous scanning and with guaranteed anti-coupling effect, which is less difficult to manufacture and has a higher yield rate compared to existing Lissajous scanners.
[0028] Therefore, the difference satisfies that when the first piezoelectric actuator 100 performs Lissajous scanning under the drive signal, the scanner cantilever has sufficient amplitude so that the vibration of the scanner cantilever in the horizontal direction and in the vertical direction will not couple.
[0029] Generally, the difference ranges from 10Hz to 12kHz. More preferably, the difference ranges from 1kHz to 10kHz. Specifically, the difference is selected based on the V-order natural frequency of the scanner arm in the horizontal direction. The difference is sufficient to ensure that the scanner arm has sufficient amplitude when the piezoelectric actuator performs Lissajous scanning 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.
[0030] The optical fiber is fixedly mounted on the upper or lower surface of the sheet-like piezoelectric actuator 200, or disposed inside the sheet-like piezoelectric actuator 200, using a cantilever support method. The cantilever support refers to the portion of the optical fiber extending beyond the front end of the sheet-like piezoelectric actuator 200 forming an optical fiber cantilever, with the portion of the optical fiber located behind the cantilever fixedly connected to the sheet-like piezoelectric actuator 200. In one embodiment where the optical fiber is disposed inside the sheet-like piezoelectric actuator 200, the sheet-like piezoelectric actuator 200 body has a mounting hole for accommodating the optical fiber, and the optical fiber is fixedly mounted within the mounting hole using a cantilever support method.
[0031] As an example of the first piezoelectric actuator 100:
[0032] like Figure 3 As shown, the cylindrical actuator has a cylindrical body as a whole, with the axis of the body arranged in the front-to-back direction. The rear end of the body is fixedly connected to the base 400, and the front part of the body is connected to the rear end of the plate-shaped piezoelectric actuator 200.
[0033] The driving method for the cylindrical body can be either by attaching a piezoelectric sheet or by having the body itself made of piezoelectric material, with driving electrodes arranged at corresponding positions on its inner and outer surfaces. The structure of the cylindrical actuator, as well as the aforementioned arrangement of piezoelectric sheets or driving electrodes, are all conventional techniques in this field.
[0034] like Figure 4 As shown, the cylindrical actuator has a cylindrical body, which can be either square or rectangular in cross-section. The axis of the body is oriented along the front-to-back direction. The rear end of the cylindrical body is fixedly connected to the base 400, and the front end of the cylindrical body is connected to the rear end of the sheet-like piezoelectric actuator 200. Preferably, when the cylindrical body has a rectangular cross-section, the long side of the body is parallel to the sheet-like piezoelectric actuator 200, so that the direction in which the sheet-like piezoelectric actuator 200 raises its natural frequency is at a higher natural frequency than the body itself.
[0035] The cylindrical actuator, with a similar driving method to a cylindrical body, can be driven by attaching a piezoelectric sheet, or by using a piezoelectric material as the cylindrical body itself, with driving electrodes arranged at corresponding positions on its inner and outer surfaces. The cylindrical actuator structure, as well as the aforementioned arrangement of piezoelectric sheets or driving electrodes, are all conventional techniques in this field.
[0036] like Figure 5 As shown, the square rod actuator has a square rod-shaped body. The square rod can have a square or rectangular cross-section. The axis of the body is set along the front-to-back direction. The rear end of the body is fixedly connected to the base 400, and the front part of the body is connected to the rear end of the sheet-like piezoelectric actuator 200. Preferably, when the square rod has a rectangular cross-section, the long side of the body is set parallel to the sheet-like piezoelectric actuator 200, so that the direction in which the sheet-like piezoelectric actuator 200 raises its natural frequency is at a higher direction than the natural frequency of the body itself.
[0037] The driving method for a square rod actuator can be achieved by attaching a piezoelectric element. The structure of the square rod actuator, as well as its driving method and structure, are all conventional techniques in this field.
[0038] like Figure 6 As shown, the cylindrical actuator has a cylindrical body with its axis arranged in the front-to-back direction. The rear end of the body is fixedly connected to the base 400, and the front part of the body is connected to the rear end of the sheet-like piezoelectric actuator 200.
[0039] The driving method for a cylindrical rod actuator can be achieved by attaching a piezoelectric element. The structure of the cylindrical rod actuator, as well as its driving method and structure, are all conventional techniques in this field.
[0040] Optionally, the sheet-like piezoelectric actuator 200 is a single piezoelectric actuator or a dual piezoelectric actuator.
[0041] 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.
[0042] All features disclosed in this specification, except for mutually exclusive features, can be combined in any way.
[0043] 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.
[0044] This application is not limited to the specific embodiments described above. This application extends to any new features or combinations disclosed in this specification, as well as any new steps or combinations of any new methods or processes disclosed.
Claims
1. A Lissajous scanner, characterized in that, The system includes a base, a first piezoelectric actuator, a sheet-like piezoelectric actuator, and an optical fiber. The first piezoelectric actuator is a one-dimensional scanning piezoelectric actuator. The fixed end of the first piezoelectric actuator is fixedly connected to the base, and the free end of the first piezoelectric actuator vibrates along a first direction. With the free end of the first piezoelectric actuator as the front end and the fixed end as the rear end, and the first direction as the left-right direction, the rear end of the sheet-like piezoelectric actuator is fixedly connected to the free end of the first piezoelectric actuator. The sheet-like piezoelectric actuator is arranged parallel to the horizontal plane, and the sheet-like piezoelectric actuator and the first piezoelectric actuator are positioned in the front-back direction... The scanner has an overlapping portion, and the front end of the sheet piezoelectric actuator vibrates in the vertical direction. The optical fiber is fixedly mounted on the front end of the sheet piezoelectric actuator in a cantilever support manner. The first piezoelectric actuator, the sheet piezoelectric actuator, and the optical fiber constitute the scanner cantilever. The sheet piezoelectric actuator and the overlapping portion make the natural frequency of the scanner cantilever in the horizontal direction greater than its natural frequency of the same order in the vertical direction, and make a difference between a certain natural frequency of the scanner cantilever in the vertical direction that is closest to its natural frequency of V in the horizontal direction and the natural frequency of V in the horizontal direction, where V is an integer greater than or equal to 1.
2. A Lissajous scanner as described in claim 1, characterized in that, The difference satisfies the requirement that when the first piezoelectric actuator performs a Lissajous scan under the drive signal, the scanner cantilever has a sufficient amplitude, and that the vibrations of the scanner cantilever in the horizontal and vertical directions do not couple.
3. A Lissajous scanner as described in claim 1 or 2, characterized in that, The natural frequency of the first piezoelectric actuator in the left-right direction is the same as or similar to its natural frequency in the vertical direction.
4. A Lissajous scanner as described in claim 1 or 2, characterized in that, The difference range is 10Hz to 12KHz.
5. A Lissajous scanner as described in claim 4, characterized in that, The difference range is 1kHz to 10kHz.
6. A Lissajous scanner as described in claim 1 or 2, characterized in that, The optical fiber is fixedly installed on the upper or lower surface of the support plate or inside the support plate in a cantilever support manner.
7. A Lissajous scanner as described in claim 1 or 2, characterized in that, The piezoelectric actuator includes a cylindrical piezoelectric actuator, a square tube piezoelectric actuator, a square bar piezoelectric actuator, or a round bar piezoelectric actuator.
8. A Lissajous scanner as described in claim 1 or 2, characterized in that, The aforementioned sheet-shaped piezoelectric actuator is a single piezoelectric actuator or a dual piezoelectric actuator.