A laser interference spot homogenization device

Abstract

The present invention relates to the field of laser projection technology, and in particular to a laser interference spot homogenization device. The present invention overcomes the technical problems of existing interference spot homogenization devices, such as large size, high cost, and low utilization of diffusers and space dimensions. The present invention places a diffuser in a light-through hole of a translation plate, and by driving the translation plate to perform a large-amplitude, high-frequency in-plane circular sweep, the diffuser is driven to perform a two-dimensional in-plane circular or elliptical sweep motion, thereby achieving effective homogenization of the laser interference spot at a lower cost and smaller size. Furthermore, by rationally arranging the positions of various functional structures, the space occupied by the entire device is fully utilized, reducing the space occupied by the entire device, and making the optical path design of the laser projection system more flexible.

Description

Technical Field

[0001] The present invention relates to the technical field of laser projection, and in particular to a laser interference spot homogenization device. Background Art

[0002] Laser projection technology has attracted widespread attention from researchers and the market due to its advantages, including high image contrast, clear imaging, vivid colors, and high brightness. However, the strong coherence of laser light leads to the appearance of alternating light and dark interference spots during laser projection, seriously affecting image quality. Using in-plane motion to homogenize the laser interference spot is a common method for eliminating interference spots. For example, in laser projection, a vibrating screen is used to eliminate reflected laser interference spots, while in laser televisions, a moving diffuser is placed in the optical path to homogenize the laser interference spot and eliminate interference spots.

[0003] In laser TV applications, the effect of homogenizing interference spots is closely related to the linear velocity and trajectory length of the diffuser. The higher the linear velocity, the more times the pattern is superimposed per unit area per unit time, the longer the motion trajectory, the richer the superimposed pattern style, and the better the homogenization effect. The invention patent (CN 113093398 A) installs the diffuser on a rotating component, and uses the rotating component as an actuator. The rotating component drives the diffuser to rotate to achieve the in-plane movement of the diffuser. However, the position where the light beam passes through needs to be outside the diffuser to ensure sufficient linear velocity. A larger diffuser is required, and the entire device occupies a large space. In addition, the light beam only passes through a local position of the diffuser. Only the part rotated to the position of the light beam has the effect of eliminating interference spots. For example, see the attached patent. Figure 11-8 3. The utilization rate of the diffuser and the space size is low, and the high-speed rotating drive components and high-speed, long-life bearings are also very expensive.

[0004] As laser TVs have an increasingly urgent need for miniaturized projection systems, the space for setting up interference spot homogenization devices in the optical path is often limited. Therefore, the laser interference spot homogenization device is required to occupy as little space as possible. Summary of the Invention

[0005] The purpose of the present invention is to provide a laser interference spot homogenization device that overcomes the technical problems of existing interference spot homogenization devices, such as large size, high cost, and low utilization of diffuser and space size. The present invention places the diffuser in the light hole of a translation plate, and drives the translation plate to perform a large-value and high-frequency in-plane circular sweep, thereby driving the diffuser to perform a two-dimensional in-plane circular or elliptical sweep motion, thereby achieving effective homogenization of the laser interference spot at a relatively low cost. In addition, by rationally arranging the positions of various functional structures, the space is fully utilized, the space occupied by the entire device is reduced, and the optical path design of the laser projection system is more flexible.

[0006] The technical solution of the present invention is:

[0007] A laser interference spot homogenization device is characterized in that it comprises a fixed plate, a translation plate, a diffuser, m sets of elastic components located between the fixed plate and the translation plate and connected to the fixed plate and the translation plate at both ends, and n sets of electromagnetic drive components fixed between the fixed plate and the translation plate; wherein m and n are both integers greater than or equal to 2;

[0008] A light-transmitting area is provided on the fixed plate; a second light-transmitting hole is provided on the translation plate; a diffuser is fixed in the second light-transmitting hole of the translation plate; the positions of the light-transmitting area and the second light-transmitting hole must ensure that the light beam can be incident on the diffuser through the light-transmitting area;

[0009] Each group of elastic components is composed of the same or different numbers of elastic elements;

[0010] N sets of electromagnetic drive components are arranged in two different directions, used to drive the moving plate to perform resonant motion relative to the fixed plate in two mutually perpendicular directions within the plane of the moving plate, and the phase difference between the two directions of motion is 90° or 270°, driving the diffuser to perform two-dimensional circular or elliptical scanning motion within the plane, realizing effective homogenization of the laser interference spot.

[0011] Furthermore, the laser interference spot homogenization device also includes a feedback component; one end of the feedback component is fixed to the fixed plate, and the other end extends to a set distance from the edge of the translation plate. When the translation plate drives the diffuser to perform a two-dimensional circular or elliptical sweeping motion in the plane, the feedback component contacts the edge of the translation plate and provides feedback on the amplitude and phase of the motion in both directions;

[0012] Alternatively, one end of the feedback component is fixed to the translating plate, and the other end extends to a set distance from the edge of the fixed plate. When the translating plate drives the diffuser to perform a two-dimensional circular or elliptical motion within the plane, the feedback component contacts the edge of the fixed plate and feeds back the amplitude and phase of the motion in both directions.

[0013] Furthermore, the functional area of ​​the translation plate is hollowed out; the hollowed-out area of ​​the translation plate includes a rectangular notch formed on the translation plate; the sidewalls of the rectangular notch are made of metal; the sidewall extending along the Y direction is defined as the X-direction feedback metal plate edge, and the sidewall extending along the X direction is defined as the Y-direction feedback metal plate edge; wherein the X direction and the Y direction represent two mutually perpendicular directions;

[0014] The feedback component contacts the edge of the Y-direction feedback metal plate and feeds back the amplitude and phase of the Y-direction motion. The feedback component contacts the edge of the X-direction feedback metal plate and feeds back the amplitude and phase of the X-direction motion.

[0015] Or hollow out outside the functional area of ​​the fixed plate;

[0016] The hollow area of ​​the fixing plate includes a rectangular notch formed in the fixing plate; the sidewalls of the rectangular notch are made of metal; the sidewall extending along the Y direction is defined as the X-direction feedback metal plate edge, and the sidewall extending along the X direction is defined as the Y-direction feedback metal plate edge; wherein the X direction and the Y direction represent two mutually perpendicular directions;

[0017] The feedback component contacts the edge of the X-direction feedback metal plate and feeds back the amplitude and phase of the X-direction motion. The feedback component contacts the edge of the Y-direction feedback metal plate and feeds back the amplitude and phase of the Y-direction motion.

[0018] Furthermore, to avoid interference between feedback in the two directions, the feedback assembly includes an X-direction feedback element and a Y-direction feedback element. The other ends of the X-direction feedback element and the Y-direction feedback element extend into the rectangular notch of the translation plate and are staggered with each other. The distance between the X-direction feedback element and the edge of the X-direction feedback metal plate is equal to the X-direction target amplitude, and the distance between the Y-direction feedback element and the edge of the Y-direction feedback metal plate is equal to the Y-direction target amplitude; the distance between the X-direction feedback element and the edge of the Y-direction feedback metal plate is greater than the Y-direction target amplitude, and the distance between the Y-direction feedback element and the edge of the X-direction feedback metal plate is greater than the X-direction target amplitude.

[0019] Furthermore, the laser interference spot homogenization device also includes a terminal seat; the terminal seat is welded to the fixed plate through corresponding pads, and is used to lead out all electrical signals of the interference spot homogenization device; each set of electromagnetic drive components includes a drive coil and a magnet arranged at the drive end of the drive coil, the drive coil is arranged on the fixed plate and the magnet is arranged on the translation plate; or, the drive coil is arranged on the translation plate and the magnet is arranged on the fixed plate.

[0020] Furthermore, each set of electromagnetic drive components includes at least two magnets, which are respectively arranged at the two driving ends of the drive coil, and the polarities of the two magnets are opposite and the centers are located on the axial center line of the drive coil.

[0021] Furthermore, in order to improve the high-cycle fatigue life of the elastic elements, the number of elastic elements in at least one of the m groups of elastic components is greater than or equal to 2. The elastic elements are made of conductive materials to provide an electrical signal path for the drive coil and feedback signal located on the translation plate to be transmitted to the fixed plate. At the same time, the resonant frequency of the actuator can be adjusted by adjusting the number of elastic elements.

[0022] Furthermore, in order to make the translation plate translate in the X and Y directions, the number of elastic elements in each group of elastic components is the same, and the m groups of elastic components are symmetrical about the central axis of the fixed plate, or the number of elastic elements in each group of elastic components is different, and the positions are not symmetrical about the central axis of the laser interference spot homogenization device, forming an asymmetric structure. The translation direction of the translation plate can also move in two mutually perpendicular directions different from the axial center line of the driving coil.

[0023] Furthermore, in order to ensure that the translational displacements on both sides are the same when the translational plate translates in one direction, n=4, and two electromagnetic drive assemblies form a group of drive units, which includes two groups of drive units in total; the two sets of electromagnetic drive assemblies in the same group of drive units are used to drive the translational plate to move in the same direction relative to the fixed plate within the plane where the translational plate is located.

[0024] Furthermore, the laser interference spot homogenization device further comprises a driving coil support base and a magnet support base; the driving coil is fixed on the driving coil support base, and the magnet is fixed on the magnet support base;

[0025] The driving coil support seat is fixed on the fixed plate, and the magnet support seat is fixed on the translation plate, or the driving coil support seat is fixed on the translation plate, and the magnet support seat is fixed on the fixed plate.

[0026] Furthermore, the drive coil support seat includes a support frame and a coil positioning structure fixed on the support frame. A slot is provided at one end of the coil positioning structure, and the two driving ends of the drive coil are snapped into the slot to achieve fixation; the axial center lines of the drive coils of the two sets of electromagnetic drive components in one group of drive units are parallel to the X direction, and the axial center lines of the drive coils of the two sets of electromagnetic drive components in the other group of drive units are parallel to the Y direction.

[0027] Furthermore, a first light-through hole can be provided in the light-transmitting area of ​​the fixed plate to facilitate direct light beam passage and incident on the diffuser placed in the second light-through hole. To provide a path for the device's drive signals and the diffuser's electrical signals, a PCB circuit board is used as the fixed plate. The output terminals of the drive coil can be soldered to corresponding pads on the fixed plate or the translatory plate.

[0028] Furthermore, the translation plate may also adopt a PCB circuit board to provide a path for the electrical signal.

[0029] Furthermore, the fixed plate and the translation plate are both rectangular PCB circuit boards, the two are parallel to each other, and the center of the fixed plate and the center of the translation plate are located in the same straight line;

[0030] The light-transmitting area of ​​the fixed plate is located at the center of the fixed plate, and the second light-transmitting hole of the translation plate is located at the center of the translation plate;

[0031] m=4, the four sets of elastic components are parallel to each other, one end of which is fixed at the four diagonal corners of the fixed plate, and the other end is fixed at the four diagonal corners of the moving plate; the electromagnetic drive component is located between any two adjacent elastic components; the rectangular gap is located directly below the drive coil, and in each set of electromagnetic drive components, the gap between the drive coil and the two magnets is equal to g1=g2, and is greater than the motion amplitude in that direction.

[0032] Furthermore, the driving coil is made of a wire wound on a magnetic core, and the cross-section of the magnet is rectangular. When reducing two-dimensional movement, the relative position of the core magnet of the driving structure changes due to movement in one direction due to movement in another direction, resulting in the problem of interference with the driving force in that direction.

[0033] The beneficial effects of the present invention are:

[0034] 1. The laser interference spot homogenization device of the present invention is small in size;

[0035] The present invention places a diffuser in the second light-passing hole of the in-plane translating plate, and drives the translating plate to perform large-amplitude and high-frequency in-plane motion through an electromagnetic drive assembly, driving the diffuser to perform two-dimensional in-plane circular or elliptical sweeping motion, thereby achieving effective homogenization of the laser interference spot; the fixed plate and the translating plate are arranged at both ends of the device in the Z direction, and the electromagnetic drive assembly is placed between the fixed plate and the translating plate (located inside the structure, reducing the size of the device in the X and Y directions). This fully utilizes the space while reducing the space occupied by the device, making the optical path design of the laser projection system more flexible.

[0036] 2. The laser interference spot homogenization device of the present invention has low cost;

[0037] The present invention uses an electromagnetic drive structure to drive the translational plate to perform a large-amplitude, high-frequency in-plane sweeping motion, driving the diffuser to perform a two-dimensional in-plane sweeping circular or elliptical motion. This is easier to implement and less expensive than a rotational drive. Furthermore, the sweeping circular or elliptical motion of the diffuser as a whole significantly reduces the required diffuser area compared to a method where the diffuser rotates in-plane, significantly reducing device cost.

[0038] 3. The laser interference spot homogenization device of the present invention has high precision and can achieve accurate adjustment of motion amplitude and phase;

[0039] The circular or elliptical motion formed by two-dimensional vibration coupling has become a common choice for in-plane resonance solutions because it can eliminate the low-speed section of the vibration process and the beam trajectory length relative to the diffuser is long. For devices operating at the resonant frequency, the amplitude and phase between the two directions are easily disturbed by external factors (temperature, shock, and vibration). When the amplitude is small, the movement speed decreases and the motion trajectory becomes shorter. When the phase changes, the circular motion trajectory cannot be guaranteed, affecting the homogenization effect. Therefore, the amplitude and phase need to be monitored. The lack of amplitude and phase feedback limits the practical application of existing in-plane two-dimensional motion resonant devices.

[0040] The present invention fixes the amplitude and phase feedback components on a fixed plate, contacts a specific area of ​​the translation plate during the movement of the translation plate, obtains the movement amplitude and phase of the translation plate based on the contact action and contact time, and thus realizes accurate adjustment of the movement amplitude and phase.

[0041] 4. The feedback component of the present invention is simple and easy to implement, which helps to further reduce the cost of the device.

[0042] 5. The laser interference spot homogenization device of the present invention has a long service life;

[0043] This invention utilizes multiple groups of elastic elements as the elastic assembly, ensuring a high high-cycle fatigue life while maintaining the resonant frequency, thereby extending the device's service life. Furthermore, the fixed and translating plates are positioned at both ends of the device in the Z direction, fully utilizing the Z-direction space and maximizing the elastic element's length. This reduces stress during deformation and further increases the elastic element's fatigue life.

[0044] 6. The present invention arranges magnets of opposite polarity on either side of the drive coil, creating a significantly smaller electromagnetic drive assembly. These two magnets, under the action of the drive coil, generate a push-pull force, significantly increasing the driving force and enabling the actuator to easily achieve large displacement translation. Furthermore, the centers of the two magnets are located on the axial centerline of the drive coil, minimizing mutual interference between the driving forces of the two directional actuators.

[0045] 7. The present invention uses elastic elements made of conductive materials to provide elastic restoring force for the actuator and at the same time provide an electrical signal path for the components moving on the translation plate to be transmitted to the fixed plate, thus overcoming the difficulty of establishing the electrical signal path for the movable components.

[0046] 8. The present invention can adjust the resonant frequency of the translation plate by adjusting the number of elastic elements, and can adjust the translation direction of the translation plate by adjusting the number and arrangement of each group of elastic elements, so that the actuator can be flexibly applied to various application scenarios.

[0047] 9. The present invention realizes two-dimensional translation by arranging electromagnetic drive components on both sides in two directions. The arrangement of the electromagnetic structure on both sides in one direction makes the motion amplitude on both sides of the translation plate uniform, while further increasing the driving force and making it easier to achieve large-displacement translation.

[0048] 10. The fixed plate and the translation plate in the laser interference spot homogenization device of the present invention can both be made of PCB circuit boards to provide pathways for the device's driving electrical signals and the electrical signals of the diffuser. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 This is a schematic structural diagram of a laser interference spot homogenizer according to an embodiment of the present invention;

[0050] Figure 2 This is an exploded schematic diagram of the structure of a laser interference spot homogenizer according to an embodiment of the present invention;

[0051] Figure 3 This is an exploded schematic diagram of the local structure of the laser interference spot homogenizer according to an embodiment of the present invention;

[0052] Figure 4 Schematic diagram of the installation structure of the driving coil support and the driving coil in the laser interference spot homogenizer according to an embodiment of the present invention;

[0053] Figure 5 This is a schematic diagram of the installation structure between the driving coil, magnet, and magnet support in the laser interference spot homogenizer according to an embodiment of the present invention;

[0054] Figure 6 Schematic diagram of the coordinated structure of the drive coil and magnet in the laser interference spot homogenizer according to an embodiment of the present invention; wherein (A), (B), (C), and (D) respectively represent different magnet pole arrangements;

[0055] Figure 7 This is a schematic diagram of the structure of a single electromagnetic drive component in a laser interference spot homogenizer according to an embodiment of the present invention;

[0056] Figure 8 This is a schematic diagram of the connections among the fixed plate, the translation plate, the elastic element, and the feedback assembly in the laser interference spot homogenizer according to an embodiment of the present invention;

[0057] Figure 9 Schematic diagram of the structure of the translation plate in the laser interference spot homogenizer according to an embodiment of the present invention;

[0058] Figure 10 Schematic diagram of the structure of the fixed plate in the laser interference spot homogenizer according to an embodiment of the present invention;

[0059] Figure 11 Schematic diagram of the connection of all drive coils in the laser interference spot homogenizer according to an embodiment of the present invention; in Figure a, the drive coils are connected in series, while in Figure b, the drive coils on the opposite side are connected in parallel;

[0060] Figure 12 The working principle of the laser interference spot homogenizer of the embodiment of the present invention is shown as follows: Figure 1 ;

[0061] Figure 13 The working principle of the laser interference spot homogenizer of the embodiment of the present invention is shown as follows: Figure 2 .

[0062] The accompanying drawings are denoted as follows:

[0063] 1. Terminal block; 2. Fixing plate; 2-3.1. First pin hole; 2-3.2. Second pin hole; 2-4.1. X-axis feedback element positioning hole group; 2-4.2. Y-axis feedback element positioning hole group; 2-7.1. First elastic component upper positioning hole; 2-7.2. Second elastic component upper positioning hole; 2-7.3. Third elastic component upper positioning hole; 2-7.4. Fourth elastic component upper positioning hole; 3. Drive coil support base; 3.1. First positioning pin; 3. 2. Second positioning pin; 3.3. Positioning hole; 3.4. Positioning pin hole; 3-5.1. First coil positioning structure; 3-5.2. Second coil positioning structure; 3-5.3. Third coil positioning structure; 3-5.4. Fourth coil positioning structure; 4.1. X-direction feedback element; 4.2. Y-direction feedback element; 5. Driving coil; 5.1. First driving coil; 5.2. Second driving coil; 5.3. Third driving coil; 5.4. Fourth driving coil; 6. Magnet support seat; 6.1. First magnet support seat; 6.2. Second magnet support seat; 6.3. Third magnet support seat; 6.4. Fourth magnet support seat; 7. Elastic component; 7.1. First elastic component; 7.2. Second elastic component; 7.3. Third elastic component; 7.4. Fourth elastic component; 8. Diffuser; 9. Translation plate; 9.1. X-direction feedback metal plate edge; 9.2. Y-direction feedback metal plate edge; 9-7.1. Bottom of first elastic component Positioning hole; 9-7.2, positioning hole under the second elastic component; 9-7.3, positioning hole under the third elastic component; 9-7.4, positioning hole under the fourth elastic component; 10, magnet assembly; 10.1.1, first magnet; 10.1.2, second magnet; 10.2.1, third magnet; 10.2.2, fourth magnet; 10.3.1, fifth magnet; 10.3.2, sixth magnet; 10.4.1, seventh magnet; 10.4.2, eighth magnet. DETAILED DESCRIPTION

[0064] To make the above-mentioned objects, features, and advantages of the present invention more clearly understood, the following detailed description of the specific embodiments of the present invention is given in conjunction with the accompanying drawings. It is obvious that the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in this field without creative work should fall within the scope of protection of the present invention.

[0065] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0066] like Figure 1 and Figure 2As shown, the laser interference spot homogenization device of this embodiment mainly consists of a fixed plate 2, a translation plate 9, a diffuser 8, at least two sets of elastic components 7 and at least two sets of electromagnetic drive components. The fixed plate 2 and the translation plate 9 are connected by at least two sets of elastic components 7. The drive component is fixed between the fixed plate 2 and the translation plate 9. The diffuser 8 is fixed in the through hole of the translation plate 9. The electromagnetic drive component drives the translation plate 9 to perform linear motion relative to the fixed plate 2 in two mutually perpendicular directions within the plane where the translation plate 9 is located, thereby driving the diffuser 8 to perform a two-dimensional circular sweep (the amplitude of the motion in the two directions is equal) or elliptical sweep (the amplitude of the motion in the two directions is unequal) motion within the plane, thereby achieving effective homogenization of the laser interference spot. In order to ensure that the elastic component 7 has a high high-cycle fatigue life, multiple elastic elements are used as the elastic component 7. The two ends of the multiple elastic elements are respectively fixed on the fixed plate 2 and the translation plate 9. The fixed plate 2 and the translating plate 9 are positioned at opposite ends of the device in the Z direction, with the electromagnetic drive assembly placed between them. This fully utilizes the space while reducing the device footprint, making the optical path design of the laser projection system more flexible. The electromagnetic drive assembly includes a drive coil 5 and a magnet. To secure the drive coil 5 and the magnet, a drive coil 5 support base 3 and a magnet support base 6 may also be provided. This embodiment also includes a feedback assembly for providing feedback on the amplitude and phase of motion in both directions.

[0067] from Figure 1 and Figure 3 As can be seen, the fixing plate 2 in this embodiment is a rectangular plate (other embodiments may also adopt circular, diamond-shaped, or other shapes). A terminal block 1 is also provided on the fixing plate 2. Terminal block 1 is soldered to the fixing plate 2 via corresponding pads, and draws out all electrical signals from the interference spot homogenization device. The fixing plate 2 also has a first pin hole 2-3.1 and a second pin hole 2-3.2. These first and second pin holes 2-3.1 and 2-3.2 engage with the first and second positioning pins 3.1 and 3.2 on the drive coil 5 support base 3, positioning the fixing plate 2 on the upper portion of the drive coil 5 support base 3 and securing it with bolts. The first elastic component upper positioning hole 2-7.1, the second elastic component upper positioning hole 2-7.2, the third elastic component upper positioning hole 2-7.3 and the fourth elastic component upper positioning hole 2-7.4 are provided at the four diagonal corners of the fixing plate 2 for connecting with the upper ends of the elastic elements in the elastic component 7 to fix the upper end of the elastic component 7; the X-direction feedback element positioning hole group 2-4.1 and the Y-direction feedback element positioning hole group 2-4.2 are also provided for fixing the feedback component (see Figure 10 A first light hole is also provided in the center of the fixing plate 2 to prevent the fixing plate 2 from blocking the light beam. In other embodiments, the first light hole may not be provided, and the area corresponding to the first light hole of the fixing plate 2 may be provided with a light-transmitting material. The fixing plate 2 may be a PCB circuit board that provides a path for the device's drive electrical signals and the electrical signals of the optical element.

[0068] like Figures 3 to 5 As shown, in order to ensure that the translational displacements on both sides are the same when the translational plate 9 translates in one direction, this embodiment includes four sets of electromagnetic drive components, two of which are arranged along the X direction, used to drive the translational plate 9 to perform linear motion along the X direction relative to the fixed plate 2 within the plane where the translational plate 9 is located. The other two sets are arranged along the Y direction, used to drive the translational plate 9 to perform linear motion along the Y direction relative to the fixed plate 2 within the plane where the translational plate 9 is located. The X direction and the Y direction represent any two mutually perpendicular directions. Figure 3 and Figure 4 It can be seen that the drive coil support seat 3 includes a support frame and a first coil positioning structure 3-5.1, a second coil positioning structure 3-5.2, a third coil positioning structure 3-5.3 and a fourth coil positioning structure 3-5.4 fixed on the support frame; a card slot is provided at one end of the coil positioning structure, and the first drive coil 5.1, the second drive coil 5.2, the third drive coil 5.3 and the fourth drive coil 5.4 are respectively inserted into the card slots of the corresponding coil positioning structures to achieve fixation, and the output end of the drive coil 5 is welded to the corresponding pad on the fixed plate 2. In addition, positioning holes 3.3 and positioning pin holes 3.4 can also be provided on the support frame, and the device can be positioned and fastened in the laser projection system by positioning pins and bolts. Figure 5 It can be seen that the magnet assembly 10 includes a first magnet 10.1.1, a second magnet 10.1.2, a third magnet 10.2.1, a fourth magnet 10.2.2, a fifth magnet 10.3.1, a sixth magnet 10.3.2, a seventh magnet 10.4.1, and an eighth magnet 10.4.2, which are respectively positioned on the first magnet support seat 6.1, the second magnet support seat 6.2, the third magnet support seat 6.3, and the fourth magnet support seat 6.4, and are coaxial with the corresponding first drive coil 5.1, the second drive coil 5.2, the third drive coil 5.3, and the fourth drive coil 5.4, respectively, to form four groups of electromagnetic drive assemblies. As can be seen from the figure, the magnet support seat 6 is aligned and positioned with the pin hole on the translation plate 9 by a locating pin. In other embodiments, the positions of the drive coil 5 support seat 3 and the magnet support seat 6 can be interchanged, that is, the drive coil 5 support seat 3 is fixed on the translation plate 9, and the magnet support seat 6 is fixed on the fixed plate 2. At this time, the output end of the drive coil 5 is welded to the corresponding welding pad on the translation plate 9. The end faces of the magnetic core are circular, rectangular or square; the cross-section of the magnet is rectangular.

[0069] like Figure 6As shown, the like poles of the magnets on the same side are arranged opposite each other. The energized coil forms a repulsive force with the magnets on one side and an attractive force with the energized coil on the other side. This push-pull force propels the magnets along the axial direction of the drive coil 5. As shown in Figure A, the north pole of the first magnet 10.1.1 faces the north pole of the second magnet 10.1.2, the north pole of the third magnet 10.2.1 faces the north pole of the fourth magnet 10.2.2, the north pole of the fifth magnet 10.3.1 faces the north pole of the sixth magnet 10.3.2, and the north pole of the seventh magnet 10.4.1 faces the north pole of the eighth magnet 10.4.2. The magnetic properties of the opposing poles can be swapped. Figures B-D show different magnet arrangements. The opposing poles of the magnets corresponding to the opposing coils can be the same or different, as long as the push-pull forces generated between the opposing coils and the magnets at the same time are in the same direction. Preferably, the two magnets on the same magnet support 6 are oppositely charged at a 90° angle, and opposite charges attract each other, making it easier to mount the magnets on the magnet support 6, as shown in Figures B and D. The gap between the drive coil 5 and the two magnets is equal to g1=g2, and is greater than the amplitude of movement in this direction, as shown in Figures B and D. Figure 7 shown.

[0070] like Figure 8 As shown, this embodiment includes four sets of elastic assemblies 7, defined as a first elastic assembly 7.1, a second elastic assembly 7.2, a third elastic assembly 7.3, and a fourth elastic assembly 7.4. Each set of elastic assemblies 7 comprises multiple elastic elements, the upper ends of which connect to corresponding connection holes on the fixed plate 2 and the lower ends connect to corresponding connection holes on the translation plate 9, providing elastic restoring force for the light spot homogenizer. The elastic elements can be made of high-strength conductive metal wires such as piano wire, stainless spring steel wire, titanium wire, and beryllium copper wire, providing a pathway for transmitting electrical signals from the moving components on the translation plate 9 to the fixed plate 2. At least one set of elastic elements in each of the four sets of elastic assemblies 7 must contain at least two elastic elements. These multiple elastic elements evenly distribute the stress generated by translation. Given the same free length and translational displacement of the elastic elements, the stress experienced by a single elastic element is significantly reduced, effectively improving the high-cycle fatigue life of the device while increasing the number of pathways for transmitting electrical signals from the moving components to the fixed plate 2.

[0071] Figure 8 In the embodiment, each group of elastic elements in the elastic assembly 7 has the same number and is positioned symmetrically about the center of the device. Adjusting the number of elastic elements can adjust the stiffness of the elastic assembly 7 and the resonant frequency of the actuator. By adjusting the number of elastic elements in each group of the elastic assembly 7 or the arrangement of each group of elastic elements 7, the translation direction of the translating plate 9 can be adjusted, ensuring that the translating plate 9 moves linearly along two mutually perpendicular directions.

[0072] like Figure 9As shown, the translation plate 9 of this embodiment is also a rectangular plate, and a PCB circuit board can be used to provide a path for electrical signals. A second light-through hole is provided in the center, and the diffuser 8 is positioned in the second light-through hole. The first elastic component lower positioning hole 9-7.1, the second elastic component lower positioning hole 9-7.2, the third elastic component lower positioning hole 9-7.3, and the fourth elastic component lower positioning hole 9-7.4 are provided at the four diagonal corners of the translation plate 9 for connecting with the lower ends of the elastic elements in the elastic component 7 to fix the lower end of the elastic component 7; combined with Figure 9 As shown, the first elastic component lower positioning holes 9-7.1, the second elastic component lower positioning holes 9-7.2, the third elastic component lower positioning holes 9-7.3, and the fourth elastic component lower positioning holes 9-7.4 on the movable plate 9 correspond one-to-one with the first elastic component upper positioning holes 2-7.1, the second elastic component upper positioning holes 2-7.2, the third elastic component upper positioning holes 2-7.3, and the fourth elastic component upper positioning holes 2-7.4 on the fixed plate 2. The upper and lower ends of the elastic elements can be fixed to the corresponding through-holes in the fixed plate 2 and the movable plate 9 by welding. To reduce the weight of the movable plate 9, the functional areas of the movable plate 9 are hollowed out. As can be seen from the figure, the main hollowed-out area consists of the rectangular notch provided in the movable plate 9.

[0073] The side walls of the rectangular notch are made of metal, which makes it easier for the feedback component to feedback the amplitude and phase information of the movement in two directions. Figure 8 The sidewall extending in the Y direction is defined as the X-direction feedback metal plate edge 9.1, and the sidewall extending in the X direction is defined as the Y-direction feedback metal plate edge 9.2 (see Figure 9 ). The feedback assembly of this embodiment includes two independent feedback elements, namely the X-direction feedback element 4.1 and the Y-direction feedback element 4.2. One end of the X-direction feedback element 4.1 and the Y-direction feedback element 4.2 are respectively welded to the X-direction feedback element positioning hole group 2-4.1 and the Y-direction feedback element positioning hole group 2-4.2 of the fixed plate 2, and the other end extends downward into the rectangular notch of the translation plate 9, and the two are staggered to avoid interference between the two direction feedbacks. The specific staggering method can be: the distance between the X-direction feedback element 4.1 and the X-direction feedback metal plate edge 9.1 is equal to the X-direction target amplitude, and the distance between the Y-direction feedback element 4.2 and the Y-direction feedback metal plate edge 9.2 is equal to the Y-direction target amplitude; the distance between the X-direction feedback element 4.1 and the Y-direction feedback metal plate edge 9.2 is greater than the Y-direction target amplitude, and the distance between the Y-direction feedback element 4.2 and the X-direction feedback metal plate edge 9.1 is greater than the X-direction target amplitude.

[0074] Combine Figure 9In the process of the translation plate 9 driving the diffuser 8 to move in two directions under the drive of the electromagnetic driver, the Y-direction feedback element 4.2 contacts the Y-direction feedback metal plate edge 9.2 and feeds back the amplitude and phase of the Y-direction movement, and the X-direction feedback element 4.1 contacts the X-direction feedback metal plate edge 9.1 and feeds back the amplitude and phase of the X-direction vibration.

[0075] The X-direction feedback element positioning hole group 2-4.1 and the Y-direction feedback element positioning hole group 2-4.2 on the fixed plate 2 are multiple through holes. Selecting through holes with different distances from the X-direction feedback metal plate edge 9.1 or the Y-direction feedback metal plate edge 9.2 can be suitable for feedback of different target amplitudes.

[0076] The working principle of the laser interference spot homogenization device for sweeping circular or elliptical motion is as follows: a drive signal is applied to the two drive coils 5 on opposite sides, the first drive coil 5.15 and the third drive coil 5.35. The push-pull force with the same direction formed between the coils and the corresponding magnets pushes the translation plate 9 to drive the diffuser 8 to vibrate along the Y direction. A drive signal is applied to the two drive coils 5 on opposite sides, the second drive coil 5.25 and the fourth drive coil 5.45. The push-pull force with the same direction formed between the coils and the corresponding magnets pushes the translation plate 9 to drive the diffuser 8 to vibrate along the X direction. This drives the diffuser 8 to vibrate in two mutually perpendicular directions, X and Y. By driving the X and Y directions at the same frequency and adjusting their phase difference to 90° or 270°, the sweeping circular or elliptical motion of the diffuser 8 can be achieved. The vibrating diffuser 8 will homogenize the laser beam passing through it, eliminating the unevenness of the light spot caused by laser interference.

[0077] like Figure 11 As shown, two drive coils 5 located on opposite sides, such as the first drive coil 5.15 and the third drive coil 5.35, can be connected in series or in parallel to generate driving forces in the same direction on both sides. Similarly, the second drive coil 5.25 and the fourth drive coil 5.45 can be connected in series or in parallel.

[0078] Optionally, the driving signal is a sine wave, a square wave, or a pulse waveform.

[0079] Preferably, the driving signal adopts a pulse waveform, and the driving current is adjusted by adjusting the duty cycle of the pulse waveform.

[0080] The working principle of the laser interference spot homogenization device feedback is as follows Figure 12As shown, a high-level voltage passes through fixed plate 2, the elastic element, the translation plate 9, the X-direction feedback metal plate edge 9.1 or the Y-direction feedback metal plate edge 9.2, the feedback element, fixed plate 2, and the low-level voltage to form a feedback circuit. By detecting the voltage level on the feedback element, it is determined whether the feedback element contacts the X-direction feedback metal plate edge 9.1 or the Y-direction feedback metal plate edge 9.2 and the contact time, thereby achieving online monitoring of the vibration amplitude and phase. By selecting a through hole in the Y-direction feedback element positioning hole group 2-4.2 on fixed plate 2, the distance between the Y-direction feedback element 4.2 and the Y-direction feedback metal plate edge 9.2 is set, thereby setting the amplitude of the Y-direction vibration to be fed back (i.e., the target amplitude). By selecting a through hole in the X-direction feedback element positioning hole group 2-4.1 on fixed plate 2, the distance between the X-direction feedback element 4.1 and the X-direction feedback metal plate edge 9.1 is set, thereby setting the amplitude of the X-direction vibration to be fed back (sweeping circular motion requires both amplitudes to be equal). When the vibration amplitude in either direction does not reach the set amplitude, no feedback signal is detected on the corresponding feedback element. The drive signal in the corresponding direction needs to be adjusted, increasing the current to increase the driving force and the motion amplitude until a feedback signal appears. When the vibration amplitude in either direction reaches the set amplitude, Y-direction feedback element 4.2 contacts Y-direction feedback metal plate edge 9.2, and a high-level feedback signal is detected on Y-direction feedback element 4.2, indicating that the Y-direction vibration amplitude has reached the set amplitude. Meanwhile, X-direction feedback element 4.1 contacts X-direction feedback metal plate edge 9.1, and a high-level feedback signal is detected on X-direction feedback element 4.1, indicating that the X-direction vibration amplitude has reached the set amplitude. If the feedback signal duration (i.e., the contact time between the feedback element and the metal plate edge) exceeds the set threshold range when the feedback signal is detected, the drive current is reduced to reduce the driving force, lowering the motion amplitude and shortening the contact time to the set threshold range, thereby stabilizing the motion amplitude. By calculating the phase difference of the high-level feedback signals of vibration in two directions, it is determined whether it is 90° or 270°, and whether it is a sweeping circular motion. By adjusting the phase of the driving signals in two directions, the phase difference of the high-level feedback signal can be kept at 90° or 270°, ensuring that the movement of the diffuser 8 is in a sweeping circular state with an accurate amplitude.

[0081] Optionally, the Y-direction feedback element 4.2 and the X-direction feedback element 4.1 can be arranged on the translation plate 9, and the corresponding metal plate edge is arranged on the fixed plate 2. The high level passes through the fixed plate 2, the elastic element, the translation plate 9, the Y-direction feedback element 4.2 and the X-direction feedback element 4.1, the metal plate edge of the upper plate, the fixed plate 2 and the low level to form a feedback circuit, such as Figure 13 As shown in FIG, here, the low level is used as the feedback signal received by the feedback element. The high and low levels can be replaced with each other, and the level triggered by the feedback element through the motion contact is used as the feedback signal.

Claims

1. A laser interference spot homogenization device, characterized in that: The invention comprises a fixed plate (2), a translation plate (9), a diffusion plate (8), m sets of elastic components (7) located between the fixed plate (2) and the translation plate (9) and having two ends respectively connected to the fixed plate (2) and the translation plate (9), and n sets of electromagnetic drive components fixed between the fixed plate (2) and the translation plate (9); wherein m and n are both integers greater than or equal to 2; A light-transmitting area is provided on the fixed plate (2); a second light-transmitting hole is provided on the translation plate (9); a diffuser (8) is fixed in the second light-transmitting hole of the translation plate (9); the positions of the light-transmitting area and the second light-transmitting hole must ensure that a light beam can be incident on the diffuser (8) through the light-transmitting area; Each group of elastic components (7) is composed of the same or different numbers of elastic elements; N sets of electromagnetic drive components are arranged in two different directions, and are used to drive the translation plate (9) to perform resonant motion relative to the fixed plate (2) in two mutually perpendicular directions within the plane where the translation plate (9) is located, and the phase difference between the two directions of motion is 90° or 270°, thereby driving the diffusion plate (8) to perform two-dimensional sweeping circular or sweeping elliptical motion within the plane; Also includes a feedback component; One end of the feedback component is fixed to the fixed plate (2), and the other end extends to a set distance from the edge of the translation plate (9). When the translation plate (9) drives the diffusion plate (8) to perform a two-dimensional circular or elliptical sweeping motion within the plane, the feedback component contacts the edge of the translation plate (9) to feedback the amplitude and phase of the motion in two directions. Alternatively, one end of the feedback component is fixed to the translation plate (9), and the other end extends to a set distance from the edge of the fixed plate (2). When the translation plate (9) drives the diffuser (8) to perform a two-dimensional circular or elliptical sweeping motion within the plane, the feedback component contacts the edge of the fixed plate (2) to feedback the amplitude and phase of the motion in two directions. The feedback component obtains the motion amplitude and phase of the translation plate based on the contact action and contact time, thereby achieving accurate adjustment of the motion amplitude and phase.

2. The laser interference spot homogenization device according to claim 1, characterized in that: The functional area of ​​the translation plate (9) is hollowed out; The hollow area of ​​the translation plate (9) includes a rectangular notch formed on the translation plate (9); the sidewalls of the rectangular notch are made of metal; the sidewall extending in the Y direction is defined as the X-direction feedback metal plate edge (9.1), and the sidewall extending in the X direction is defined as the Y-direction feedback metal plate edge (9.2); wherein the X direction and the Y direction represent two mutually perpendicular directions; The feedback component contacts the edge (9.1) of the X-direction feedback metal plate to feed back the amplitude and phase of the X-direction motion. The feedback component contacts the edge (9.2) of the Y-direction feedback metal plate to feed back the amplitude and phase of the Y-direction motion. Or the fixed plate (2) is hollowed out outside the functional area; The hollow area of ​​the fixing plate (2) includes a rectangular notch formed on the fixing plate (2); the sidewalls of the rectangular notch are made of metal; the sidewall extending in the Y direction is defined as the X-direction feedback metal plate edge (9.1), and the sidewall extending in the X direction is defined as the Y-direction feedback metal plate edge (9.2); wherein the X direction and the Y direction represent two mutually perpendicular directions; The feedback component contacts the edge (9.1) of the X-direction feedback metal plate to feed back the amplitude and phase of the X-direction motion. The feedback component contacts the edge (9.2) of the Y-direction feedback metal plate to feed back the amplitude and phase of the Y-direction motion.

3. The laser interference spot homogenization device according to claim 2, characterized in that: The feedback component comprises an X-direction feedback element (4.1) and a Y-direction feedback element (4.2); the other ends of the X-direction feedback element (4.1) and the Y-direction feedback element (4.2) extend into a rectangular notch of a translation plate (9) and are mutually staggered; the distance between the X-direction feedback element (4.1) and the edge (9.1) of the X-direction feedback metal plate is equal to the X-direction target amplitude; the distance between the Y-direction feedback element (4.2) and the edge (9.2) of the Y-direction feedback metal plate is equal to the Y-direction target amplitude; the distance between the X-direction feedback element (4.1) and the edge (9.2) of the Y-direction feedback metal plate is greater than the Y-direction target amplitude; and the distance between the Y-direction feedback element (4.2) and the edge (9.1) of the X-direction feedback metal plate is greater than the X-direction target amplitude.

4. The laser interference spot homogenization device according to claim 3, characterized in that: The invention also includes a terminal seat (1); the terminal seat (1) is welded to the fixed plate (2) via corresponding welding pads and is used to lead out all electrical signals of the interference spot homogenization device; each set of electromagnetic drive components includes a drive coil (5) and a magnet arranged at the drive end of the drive coil (5); the drive coil (5) is arranged on the fixed plate (2) and the magnet is arranged on the translation plate (9); or, the drive coil (5) is arranged on the translation plate (9) and the magnet is arranged on the fixed plate (2).

5. The laser interference spot homogenization device according to claim 4, characterized in that: Each set of electromagnetic drive components comprises at least two magnets, which are respectively arranged at the two drive ends of the drive coil (5), and the two magnets have opposite polarities and their centers are located on the axial center line of the drive coil (5).

6. The laser interference spot homogenizing device according to claim 5, characterized in that: The number of elastic elements in at least one of the m groups of elastic components (7) is greater than or equal to 2, and the elastic elements are made of conductive material to provide an electrical signal path for the feedback signal and the drive coil (5) to be transmitted to the fixed plate (2).

7. The laser interference spot homogenizing device according to claim 6, characterized in that: The number of elastic elements in each group of elastic components (7) is the same, and the m groups of elastic components (7) are symmetrical about the central axis of the fixed plate (2); or the number of elastic elements in each group of elastic components (7) is different, and the m groups of elastic components (7) form an asymmetric structure.

8. The laser interference spot homogenizing device according to claim 7, characterized in that: n=4, two electromagnetic drive assemblies form a group of drive units, which includes two groups of drive units in total; the two sets of electromagnetic drive assemblies in the same group of drive units are used to drive the translation plate (9) to move relative to the fixed plate (2) in the plane where the translation plate (9) is located along the same direction.

9. The laser interference spot homogenizing device according to claim 8, characterized in that: It also includes a driving coil support seat (3) and a magnet support seat (6); the driving coil (5) is fixed on the driving coil support seat (3), and the magnet is fixed on the magnet support seat (6); The driving coil support seat (3) is fixed on the fixed plate (2), and the magnet support seat (6) is fixed on the translation plate (9) (9), or the driving coil support seat (3) is fixed on the translation plate (9), and the magnet support seat (6) is fixed on the fixed plate (2).

10. The laser interference spot homogenizing device according to claim 9, characterized in that: The drive coil support seat (3) comprises a support frame and a coil positioning structure fixed on the support frame. A slot is provided at one end of the coil positioning structure, and two drive ends of the drive coil (5) are snapped into the slot to achieve fixation. The axial center lines of the drive coils (5) of the two sets of electromagnetic drive assemblies in one group of drive units are parallel to the X direction, and the axial center lines of the drive coils (5) of the two sets of electromagnetic drive assemblies in the other group of drive units are parallel to the Y direction.

11. The laser interference spot homogenizing device according to claim 10, characterized in that: A first light hole is provided in the light-transmitting area of ​​the fixed plate (2); the fixed plate (2) is a PCB circuit board; the output end of the drive coil (5) is welded to a corresponding welding pad of the fixed plate (2) or the translation plate (9); and the translation plate (9) is a PCB circuit board.

12. The laser interference spot homogenizing device according to claim 10, characterized in that: The fixed plate (2) and the translation plate (9) are both rectangular PCB circuit boards, the two are parallel to each other, and the center of the fixed plate (2) and the center of the translation plate (9) are located in the same straight line; The light-transmitting area of ​​the fixed plate (2) is located at the center of the fixed plate (2), and the second light-transmitting hole of the translation plate (9) is located at the center of the translation plate (9); m=4, four sets of elastic components (7) are parallel to each other, one end of each set is fixed to the four diagonal points of the fixed plate (2), and the other end is fixed to the four diagonal points of the translation plate (9); The electromagnetic drive assembly is located between two adjacent elastic assemblies (7), and the rectangular gap is located directly below the drive coil (5); in each set of electromagnetic drive assemblies, the gap between the drive coil (5) and the two magnets is equal to g1=g2, and is greater than the movement amplitude in this direction.

13. The laser interference spot homogenizing device according to claim 12, characterized in that: The driving coil (5) is formed by winding a wire on a magnetic core, and the end faces of the magnetic core are circular, rectangular or square; the cross section of the magnets in the electromagnetic driving assembly opposite to the two end faces of the magnetic core is rectangular.

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