Dynamic focusing device

Abstract

The invention discloses a dynamic focusing device, which comprises a fixed part provided with a voice coil motor; the movable part is arranged in the fixed part, the movable part is connected to the output end of the voice coil motor, a flexible connecting assembly is arranged between the movable part and the fixed part, a piezoelectric driver is arranged in the flexible connecting assembly, and the piezoelectric driver is in transmission connection with the movable part; the glasses frame is arranged on the movable part, lenses are arranged in the glasses frame, the large stroke, high positioning precision and high resolution are achieved when the lenses are adjusted, the piezoelectric actuator can be used for conducting real-time compensation on disturbance of the voice coil motor, the flexible connecting assembly is used for providing movable guiding, friction can be reduced, the creeping phenomenon can be avoided, the stability of the glasses is improved, and the service life of the glasses is prolonged. And the system is simple in overall structure and easy to produce and manufacture.

Description

Technical Field

[0001] This invention relates to the field of optical element adjustment, and more particularly to a dynamic focusing device. Background Technology

[0002] A dynamic focusing system is an electromechanical system that can change the position of the laser focus in real time, quickly and accurately during laser processing. The focus of the laser beam can move at high speed along the optical axis, thereby adapting to the processing of complex curved surfaces or compensating for position changes during processing, and solving problems such as curved surface processing and laser beam focal depth limitation encountered in laser processing.

[0003] Currently, focusing lenses are typically moved axially within the optical path by a motor, thereby changing the focal length of the light beam reaching the workpiece surface. Various motor-driven methods exist, such as servo motors, voice coil motors, or piezoelectric ceramic drives. However, servo motors struggle to meet the required precision and response frequency, voice coil motors are sensitive to disturbances and require high anti-interference capabilities from the control system, and piezoelectric ceramic drives have extremely small strokes. Furthermore, electrically driven focusing lenses generally use mechanical guides, which require lubrication and maintenance and may experience wear during movement; alternatively, electromagnetic guidance can be used, but this presents problems such as electromagnetic interference and heat generation. Therefore, there is an urgent need for a dynamic focusing device that combines large stroke, high positioning accuracy, and more stable motion guidance. Summary of the Invention

[0004] The purpose of this invention is to provide solutions to one or more technical problems existing in the prior art, and to at least provide a beneficial alternative or create conditions.

[0005] According to a first aspect of the present invention, a dynamic focusing device includes: a fixed part having a voice coil motor disposed thereon; a movable part disposed within the fixed part, the movable part being connected to the output end of the voice coil motor, a flexible connecting assembly being disposed between the movable part and the fixed part, a piezoelectric actuator being disposed within the flexible connecting assembly, the piezoelectric actuator being drively connected to the movable part; and a frame disposed on the movable part, a lens being disposed within the frame.

[0006] This technical solution has at least the following beneficial effects: The frame is equipped with lenses for dynamic focusing. During use, the voice coil motor drives the moving part to achieve millimeter-level stroke and micron-level positioning accuracy for the lens. At this time, the flexible connecting component between the moving part and the fixed part provides guidance for the moving part. Since the flexible connecting component mainly provides guidance for the moving part during movement through its own flexible deformation characteristics, the accuracy of guidance is improved. The piezoelectric actuator on the flexible connecting component can also provide driving force for the moving part, achieving micron-level stroke and nanometer-level positioning accuracy for the lens. By combining the two, millimeter-level stroke and nanometer-level positioning accuracy can be achieved. Thus, when adjusting the lens, it has both large stroke, high positioning accuracy, and high resolution. The piezoelectric actuator can be used to compensate for the disturbance of the voice coil motor in real time. Using the flexible connecting component to provide movement guidance can reduce friction, avoid crawling, and improve the rigidity of the system. The overall structure is simple and easy to manufacture.

[0007] According to some embodiments of the present invention, the flexible connection assembly includes first flexible joints symmetrically arranged on both sides of the movable portion, and piezoelectric actuators are respectively disposed on a plurality of the first flexible joints. In this embodiment, the first flexible joints symmetrically arranged on both sides of the movable portion can increase the stiffness in the non-motion direction, thereby reducing parasitic motion and improving the linearity of motion. When it is necessary to adjust the lens to a micron-level stroke and a nanometer-level positioning accuracy, the piezoelectric actuators on the plurality of first flexible joints work respectively to jointly provide a driving force for the flexible movement of the movable portion.

[0008] According to some embodiments of the present invention, the first flexible joint extends in a serpentine manner. The serpentine extension of the first flexible joint increases the range of elastic deformation, thereby improving the flexible deformation range of the first flexible joint.

[0009] According to some embodiments of the present invention, the flexible connection assembly includes a second flexible joint and a third flexible joint. The movable part includes a movable outer frame and a movable inner frame. The second flexible joint is disposed between the outer side of the movable outer frame and the fixed part. The movable inner frame is located inside the movable outer frame. The third flexible joint is disposed between the movable inner frame and the movable outer frame. The piezoelectric actuator is disposed on the third flexible joint. The frame is connected to the movable inner frame. In this embodiment, the second flexible joint and the third flexible joint independently provide movement guidance for the voice coil motor and the piezoelectric actuator, respectively. When the voice coil motor drives the movable outer frame to move, the second flexible joint guides between the fixed part and the movable outer frame. When the piezoelectric actuator drives the movable inner frame to move, the third flexible joint guides between the movable outer frame and the movable inner frame. By making the motion transmission structure independent, the guiding accuracy can be further improved and parasitic movements can be reduced.

[0010] According to some embodiments of the present invention, the second flexible joints are symmetrically arranged on both sides of the movable outer frame. The symmetrically arranged second flexible joints can increase the stiffness of the movable outer frame in the non-motion direction, thereby reducing parasitic movement and improving the linearity of motion.

[0011] According to some embodiments of the present invention, the second flexible joint extends in a serpentine manner. The serpentine extension of the second flexible joint increases the range of elastic deformation, thereby improving the flexible deformation range of the second flexible joint.

[0012] According to some embodiments of the present invention, the second flexible joint includes two elastic plates spaced apart and elastic blocks connected to both sides of the two elastic plates. One elastic plate is connected to the movable outer frame, and the other elastic plate is connected to the movable inner frame. The piezoelectric actuator is disposed between the two elastic plates. The two elastic blocks connect the two elastic plates to each other at both sides, thereby forming a double parallel flexible joint structure. This makes the movable inner frame more inclined to displacement along the optical axis when moving, improving motion guidance accuracy and reducing parasitic motion.

[0013] According to some embodiments of the present invention, the movable inner frame is provided with third flexible joints on both sides along the driving direction of the piezoelectric actuator, and the piezoelectric actuator is disposed on one of the third flexible joints. The two third flexible joints are located on both sides of the movable inner frame in the direction of movement, which can further improve the accuracy of the guiding movement of the movable inner frame, thereby further improving the accuracy of dynamic adjustment of the lens.

[0014] According to some embodiments of the present invention, the output terminals of the voice coil motor and the piezoelectric actuator are both located on the same straight line. The fact that the voice coil motor and the piezoelectric actuator are on the same straight line ensures consistency in the direction of force applied to the lens, and particularly improves the accuracy of lens adjustment when they are used together, achieving dynamic focusing with a large stroke and high resolution.

[0015] According to some embodiments of the present invention, the lens is detachably connected to the frame. During use, the lens can be disassembled and replaced as needed, improving flexibility and convenience. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly explained below. Obviously, the described drawings are only a part of the embodiments of the present invention, and not all of them. Those skilled in the art can obtain other design schemes and drawings based on these drawings without creative effort.

[0017] Figure 1 This is a perspective view of Embodiment 1 of the present invention.

[0018] Figure 2 This is a perspective view of Embodiment 2 of the present invention.

[0019] In the attached diagram: 100-fixed part, 110-voice coil motor, 210-piezoelectric actuator, 221-first flexible joint, 222-second flexible joint, 223-elastic plate, 224-elastic block, 230-moving part, 231-movable outer frame, 232-movable inner frame, 310-frame, 320-lens. Detailed Implementation

[0020] The following will clearly and completely describe the concept, specific structure, and technical effects of the present invention in conjunction with embodiments and accompanying drawings, so as to fully understand the purpose, features, and effects of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are all within the scope of protection of the present invention. Furthermore, all connection relationships mentioned herein do not simply refer to direct connection of components, but rather to the ability to form a better connection structure by adding or reducing connecting accessories according to specific implementation conditions. The various technical features in this invention can be combined interactively without contradicting each other.

[0021] The dynamic focusing device of this invention is mainly used in laser processing systems, enabling high-speed and high-precision adjustment of the laser focal point position to adapt to complex curved surface processing or compensate for positional changes during processing. This device achieves dynamic focusing with millimeter-level stroke and nanometer-level positioning accuracy by combining the large-stroke drive of the voice coil motor 110 and the micro-motion compensation of the piezoelectric actuator 210, supplemented by the guidance of flexible connecting components.

[0022] Reference Figure 1 According to a first aspect of the present invention, a dynamic focusing device includes: a fixed part 100, on which a voice coil motor 110 is disposed; a movable part 230 disposed within the fixed part 100, the movable part 230 being connected to the output end of the voice coil motor 110, a flexible connecting assembly being disposed between the movable part 230 and the fixed part 100, a piezoelectric actuator 210 being disposed within the flexible connecting assembly, the piezoelectric actuator 210 being drively connected to the movable part 230; and a frame 310 disposed on the movable part 230, a lens 320 being disposed within the frame 310.

[0023] In this dynamic focusing device, a lens 320 for dynamic focusing is mounted on the frame 310. During use, the voice coil motor 110 drives the movable part 230 to move, achieving millimeter-level stroke and micron-level positioning accuracy for the lens 320. At this time, the flexible connecting component between the movable part 230 and the fixed part 100 provides guidance for the movable part 230. Since the flexible connecting component mainly provides guidance for the movable part 230 during movement through its own flexible deformation characteristics, the accuracy of guidance is improved. The piezoelectric actuator 210 on the flexible connecting component can also provide driving force for the movable part 230, achieving micron-level stroke and nanometer-level positioning accuracy for the lens 320. By combining the two, millimeter-level stroke and nanometer-level positioning accuracy can be achieved. Thus, when adjusting the lens 320, it has both large stroke, high positioning accuracy, and high resolution. The piezoelectric actuator 210 can be used to compensate for disturbances of the voice coil motor 110 in real time. Using the flexible connecting component to provide movement guidance can reduce friction, avoid crawling, and improve the rigidity of the system. The overall structure is simple and easy to manufacture.

[0024] The fixed part 100, serving as a support structure, is made of a rigid material, such as aluminum alloy or stainless steel, to ensure overall stability. The fixed part 100 has an internal mounting groove or guide rail structure to accommodate the voice coil motor 110 and the movable part 230. The stator of the voice coil motor 110 is fixed to the fixed part 100, and the mover is directly connected to the movable part 230. When the voice coil motor 110 operates, a current is passed through it to generate a magnetic field, driving the mover to move linearly along the optical axis, thereby moving the movable part 230. The voice coil motor 110 has a stroke of several millimeters and a positioning accuracy in the micrometer range, making it suitable for a wide range of focus adjustments.

[0025] As an embodiment of a flexible connection component that flexibly connects the movable part 230 and the fixed part 100, the flexible connection component includes first flexible joints 221 symmetrically arranged on both sides of the movable part 230. Each of the first flexible joints 221 is equipped with a piezoelectric actuator 210. In practical applications, the piezoelectric actuator 210 can be an electro-bending type piezoelectric sheet. In this embodiment, the first flexible joints 221 symmetrically arranged on both sides of the movable part 230 can increase the stiffness in the non-motion direction, thereby reducing parasitic motion and improving the linearity of motion. When it is necessary to adjust the lens 320 to a micrometer-level stroke and nanometer-level positioning accuracy, the piezoelectric actuators 210 on the multiple first flexible joints 221 work separately to jointly provide a driving force for the flexible movement of the movable part 230.

[0026] Furthermore, the first flexible joint 221 extends in a serpentine shape. The serpentine extension of the first flexible joint 221 increases the range of elastic deformation, thereby improving its flexible deformation stroke. In practical applications, there can be four first flexible joints 221, located at the four corners of the movable part 230, with a piezoelectric actuator 210 positioned between each first flexible joint 221 and the fixed part 100.

[0027] Therefore, it can be seen that the present invention utilizes a flexible connecting component to achieve high-precision guidance. In Embodiment 1, the flexible connecting component includes first flexible joints 221 symmetrically arranged on both sides of the movable part 230. The first flexible joints 221 extend in a serpentine shape, i.e., a zigzag shape, to increase the elastic deformation stroke. Each first flexible joint 221 is equipped with a piezoelectric actuator 210, which is made of piezoelectric ceramic material. When energized, it undergoes micro-deformation, pushing the movable part 230 to move. The piezoelectric actuator 210 has a small stroke (micrometer level) but high resolution (nanometer level), and can be used to compensate for disturbances in the voice coil motor 110 in real time. To ensure stable movement of the movable part 230, the present invention also provides symmetrically arranged first flexible joints 221, which helps to reduce displacement in non-movement directions and improve the straightness of movement. The serpentine design of the first flexible joints 221 allows for large flexible deformation, thereby improving the stability and accuracy of guidance.

[0028] As a second embodiment of flexibly connecting the movable part 230 and the fixed part 100 with a flexible connecting component, the flexible connecting component includes a second flexible joint 222 and a third flexible joint. The movable part 230 includes a movable outer frame 231 and a movable inner frame 232. The second flexible joint 222 is disposed between the outer side of the movable outer frame 231 and the fixed part 100. The movable inner frame 232 is located inside the movable outer frame 231. The third flexible joint is disposed between the movable inner frame 232 and the movable outer frame 231. The piezoelectric actuator 210 is disposed on the third flexible joint. The frame 310 is connected to the movable inner frame 232. In practical applications, the piezoelectric actuator 210 can be an electrostrictive piezoelectric sheet. In this embodiment, the second flexible joint 222 and the third flexible joint independently provide movement guidance for the voice coil motor 110 and the piezoelectric actuator 210, respectively. When the voice coil motor 110 drives the movable outer frame 231 to move, the second flexible joint 222 guides the movement between the fixed part 100 and the movable outer frame 231. When the piezoelectric actuator 210 drives the movable inner frame 232 to move, the third flexible joint guides the movement between the movable outer frame 231 and the movable inner frame 232. By making the motion transmission structure independent of each other, the guiding accuracy can be further improved and parasitic movement can be reduced.

[0029] The movable part 230 is designed as a frame structure, which may include a movable outer frame 231 and a movable inner frame 232. The movable outer frame 231 is driven by a voice coil motor 110 to achieve a wide range of movement. The movable inner frame 232 is located inside the movable outer frame 231 and is driven by a piezoelectric actuator 210 for fine adjustment. The movable part 230 uses lightweight materials, such as titanium alloy or engineering plastics, to reduce inertia and improve response speed. The movable part 230 is connected to the fixed part 100 by a flexible connecting assembly, which not only provides guidance but also integrates the piezoelectric actuator 210.

[0030] In Embodiment 2, the flexible connection assembly includes a second flexible joint 222 and a third flexible joint. The movable part 230 includes a movable outer frame 231 and a movable inner frame 232. The second flexible joint 222 is disposed between the outer side of the movable outer frame 231 and the fixed part 100. The movable inner frame 232 is located inside the movable outer frame 231, and the third flexible joint is disposed between the movable inner frame 232 and the movable outer frame 231. The piezoelectric actuator 210 is disposed on the third flexible joint, and the frame 310 is connected to the movable inner frame 232. The second flexible joint 222 and the third flexible joint independently provide movement guidance for the voice coil motor 110 and the piezoelectric actuator 210, respectively. When the voice coil motor 110 drives the movable outer frame 231 to move, the second flexible joint 222 guides the movement between the fixed part 100 and the movable outer frame 231; when the piezoelectric actuator 210 drives the movable inner frame 232 to move, the third flexible joint guides the movement between the movable outer frame 231 and the movable inner frame 232. This independent guiding structure can reduce motion interference and improve overall accuracy.

[0031] Furthermore, the second flexible joints 222 are symmetrically arranged on both sides of the movable outer frame 231. The symmetrically arranged second flexible joints 222 can increase the stiffness of the movable outer frame 231 in the non-movement direction, thereby reducing parasitic movement and improving the linearity of movement.

[0032] Furthermore, the second flexible joint 222 extends in a serpentine shape. The serpentine extension of the second flexible joint 222 increases the range of elastic deformation that the second flexible joint 222 can undergo, thereby increasing the flexible deformation stroke of the second flexible joint 222.

[0033] As a specific embodiment of the second flexible joint 222, the second flexible joint 222 includes two elastic plates 223 spaced apart and elastic blocks 224 connected to both sides of the two elastic plates 223. One elastic plate 223 is connected to the movable outer frame 231, and the other elastic plate 223 is connected to the movable inner frame 232. The piezoelectric actuator 210 is disposed between the two elastic plates 223. The two elastic blocks 224 connect the two elastic plates 223 to each other at both sides, thereby forming a double parallel flexible joint structure. This makes the movable inner frame 232 more inclined to displacement along the optical axis when moving, improving motion guidance accuracy and reducing parasitic motion.

[0034] There can be only one third flexible joint, but in this embodiment, the movable inner frame 232 is provided with the third flexible joint on both sides along the driving direction of the piezoelectric actuator 210, and the piezoelectric actuator 210 is disposed on one of the third flexible joints. The two third flexible joints are located on both sides of the movable inner frame 232 in the direction of movement, which can further improve the accuracy of the guiding movement of the movable inner frame 232, thereby further improving the accuracy of the dynamic adjustment of the lens 320.

[0035] Furthermore, in one embodiment of the present invention, the movable inner frame 232 is provided with third flexible joints on both sides along the driving direction of the piezoelectric actuator 210. The piezoelectric actuator 210 is disposed on one of the third flexible joints. The symmetrical arrangement of the two third flexible joints can improve the guiding accuracy of the movable inner frame 232 and ensure the accuracy of micro-motion adjustment. The design of the third flexible joint is similar to that of the first flexible joint 221, but the size is smaller to accommodate the micro-motion requirements of the movable inner frame 232.

[0036] Furthermore, the output terminals of the voice coil motor 110 and the piezoelectric actuator 210 are both located on the same straight line. This alignment ensures consistency in the direction of force applied to the lens 320, particularly improving the accuracy of lens 320 adjustment when they work together, achieving dynamic focusing with a large stroke and high resolution. The output terminals of the voice coil motor 110 and the piezoelectric actuator 210 are also aligned along the optical axis. This ensures consistent driving force direction, preventing angular deviations from affecting accuracy. The voice coil motor 110 handles rapid positioning over a wide range, while the piezoelectric actuator 210 handles fine compensation; both work collaboratively through a control system. The control system can adjust the drive signal in real time based on laser focus position feedback, achieving closed-loop adjustment.

[0037] In some embodiments, the lens 320 is detachably connected to the frame 310. For example, the lens 320 can be fixed to the frame 310 by a snap-fit ​​connection. During use, the lens 320 can be disassembled and replaced as needed, improving flexibility and convenience. The frame 310 is mounted on the movable part 230, and the lens 320 is disposed within the frame 310. The lens 320 can be a lens or other optical element, selected according to laser processing requirements. To facilitate the installation and replacement of the lens 320, the present invention also provides a detachable connection structure, for example, fixing the lens 320 by threads, snaps, or magnetism. The frame 310 is designed with a positioning mechanism, such as a positioning pin or alignment groove, to ensure that the lens 320 is installed in a centered position, avoiding optical deviation.

[0038] The working principle is as follows: During laser processing, when focal length adjustment is required, the voice coil motor 110 first drives the movable part 230 (or the movable outer frame 231) to move, causing the lens 320 to achieve a wide range of focal length changes (millimeter-level stroke). Due to the fast response speed of the voice coil motor 110, it can adapt to high-speed processing requirements. Simultaneously, flexible connecting components (such as the first flexible joint 221 or the second flexible joint 222) guide the movable part 230, reducing friction and vibration through elastic deformation and avoiding crawling. If higher precision is required, the piezoelectric actuator 210 is activated, pushing the movable part 230 (or the movable inner frame 232) to move slightly, compensating for errors in the voice coil motor 110 or external disturbances. The nanometer-level resolution of the piezoelectric actuator 210 allows for extremely fine focal length adjustment. The symmetrical design and independent guiding structure of the flexible connecting components reduce parasitic motion and improve system stiffness and lifespan. This device, through the combination of the voice coil motor 110 and the piezoelectric actuator 210, balances large stroke and high precision, overcoming the limitations of traditional driving methods. Flexible connection components replace mechanical guide rails, reducing wear and maintenance needs. The overall structure is compact, easy to manufacture, and easy to integrate into existing laser systems. Furthermore, the detachable frame 310 design enhances usability.

[0039] The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to the embodiments described. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention, and these equivalent modifications or substitutions are all included within the scope defined by the claims of this application.

Claims

1. A dynamic focusing device, characterized in that: include: The fixing part (100) is equipped with a voice coil motor (110); The movable part (230) is disposed within the fixed part (100). The movable part (230) is connected to the output end of the voice coil motor (110). A flexible connection component is provided between the movable part (230) and the fixed part (100). A piezoelectric actuator (210) is disposed within the flexible connection component. The piezoelectric actuator (210) is connected to the movable part (230) in a driving manner. A frame (310) is disposed on the movable part (230), and a lens (320) is disposed inside the frame (310).

2. The dynamic focusing device according to claim 1, characterized in that: The flexible connection assembly includes first flexible joints (221) symmetrically arranged on both sides of the movable part (230), and the piezoelectric actuators (210) are respectively arranged on a plurality of first flexible joints (221).

3. The dynamic focusing device according to claim 2, characterized in that: The first flexible joint (221) extends in a serpentine shape.

4. The dynamic focusing device according to claim 1, characterized in that: The flexible connection assembly includes a second flexible joint (222) and a third flexible joint. The movable part (230) includes a movable outer frame (231) and a movable inner frame (232). The second flexible joint (222) is disposed between the outer side of the movable outer frame (231) and the fixed part (100). The movable inner frame (232) is located inside the movable outer frame (231). The third flexible joint is disposed between the movable inner frame (232) and the movable outer frame (231). The piezoelectric actuator (210) is disposed on the third flexible joint. The frame (310) is connected to the movable inner frame (232).

5. A dynamic focusing device according to claim 4, characterized in that: The second flexible joint (222) is symmetrically arranged on both sides of the movable outer frame (231).

6. A dynamic focusing device according to claim 4, characterized in that: The second flexible joint (222) extends in a serpentine shape.

7. A dynamic focusing device according to claim 4, characterized in that: The second flexible joint (222) includes two elastic plates (223) spaced apart and an elastic block (224) connected to both sides of the two elastic plates (223). One elastic plate (223) is connected to the movable outer frame (231), and the other elastic plate (223) is connected to the movable inner frame (232). The piezoelectric actuator (210) is disposed between the two elastic plates (223).

8. A dynamic focusing device according to claim 4, characterized in that: The movable inner frame (232) is provided with the third flexible joint on both sides along the driving direction of the piezoelectric actuator (210), and the piezoelectric actuator (210) is disposed on one of the third flexible joints.

9. A dynamic focusing device according to claim 1, characterized in that: The output terminal of the voice coil motor (110) and the output terminal of the piezoelectric driver (210) are both located on the same straight line.

10. A dynamic focusing device according to claim 1, characterized in that: The lens (320) is detachably attached to the frame (310).

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