A high-density, large-span, narrow-band aggregated laser scanning device and scanning method

Abstract

The present invention discloses a high-density, large-span, narrow-band aggregation laser scanning device and a scanning method. In the device, a cabinet is equipped with N lasers, imaging planes and the same number as the lasers and connected one-to-one through optical fibers. The N blade scanning units have N narrowband areas, each narrowband area includes M identical scanning partitions, and the N narrowband areas have N×M scanning partitions. The center zero position at the axis swing angle of the X-axis deflection component realizes the ultra-thin state of the blade scanning unit. The structural design of the X-axis deflection component and the Y-axis deflection component improves the stability and accuracy of the galvanometer unit, and multiple scanning partitions can be formed to scan multiple areas or targets at the same time, thereby improving the scanning efficiency, coverage and accuracy. The switching of multiple edge overlapping scanning partitions adopts a combination of synchronization and light-off switching methods, with fast switching speed and high scanning efficiency, and also ensures the continuity and integrity of the scanning data, effectively avoiding the damage or interference of the laser beam to the scanned object.

Description

Technical Field

[0001] The present invention relates to the technical field of additive manufacturing, and in particular to a high-density, large-span, narrow-band polymerized laser scanning device and a scanning method. Background Art

[0002] Laser powder bed 3D forming technology is to use a powder bed substrate to descend layer by layer and spread powder horizontally by gravity, and use a high-energy laser beam to scan and irradiate the selected area on the surface of the powder bed layer by layer, so that the irradiated powder is melted, polymerized, cooled, solidified, and deposited, and grows layer by layer on the powder bed substrate to achieve three-dimensional stereoscopic forming. The excellent directivity and focusing characteristics of the high-energy laser beam, as well as the good support and heat dissipation conditions of the free powder in the powder bed for the sediment, make the laser powder bed 3D forming technology have outstanding advantages in the application of precision and complex structure forming. There are already laser powder bed 3D forming equipment, mainly including SLM (selective laser melting) equipment and SLS (selective laser sintering) equipment. Among them, SLM is used for the 3D forming of metal powder materials, and SLS is used for the 3D forming of polymer and ceramic powder materials.

[0003] In order to efficiently scan the surface of the powder bed, the laser scanning devices equipped with SLM and SLS are generally low-inertia two-axis galvanometers based on galvanometer servo motors. Through the plane optical reflector driven by it, the incident laser beam is manipulated to precisely deflect in the X-axis and Y-axis directions, so as to achieve controlled high-speed movement of the laser spot on the surface of the powder bed. In order to compensate for the defocusing of the spot caused by the change in the optical path of the laser beam during deflection scanning, the traditional two-axis galvanometer is also equipped with a post-focusing field lens to ensure the consistency of the laser spot size during the scanning process; the field lens is a special optical lens whose focal length is a set functional relationship with the deflection angle of the incident light beam. In addition, there are also public reports of 3D scanning solutions that use an electrically controlled zoom component to control the two-axis galvanometer spot, that is, through the linkage of the zoom component and the two-axis galvanometer, the consistency control of the focal length and optical path of the beam is achieved.

[0004] With the continuous improvement of the requirements for the three-dimensional forming accuracy, forming size, and forming efficiency of the laser powder bed, the limitations of the traditional galvanometer-field mirror solution and the galvanometer-zoom solution are becoming increasingly prominent. The first is that the existing two-axis galvanometers generally have a square or circular scanning range. This feature stems from the fact that the early applications of two-axis galvanometers were mostly single-head marking, cutting, etc., which generally require a balanced X- and Y-direction coverage range. When used for large-format SLM and SLS equipment, it generally requires an array layout to meet the XY bidirectional expansion requirements. This not only brings severe challenges to the optical scanning structure layout of high-energy lasers, namely the dense arrangement of components such as laser optical cables, collimation, zoom, and galvanometers; it also brings great difficulties to installation and debugging. It is necessary to deal with complex compensations such as orthogonality, rotation, and offset of multiple components and the stable switching of each component, which greatly limits the actual forming quality of existing large-format SLM and SLS equipment. Summary of the invention

[0005] The purpose of the present invention is to provide a large-span narrow-band aggregate laser scanning device and scanning method in order to overcome the defects of the above-mentioned prior art.

[0006] The object of the present invention can be achieved by the following technical scheme: A high-density, large-span narrowband aggregation laser scanning device comprises a cabinet, wherein the cabinet is sequentially installed with N lasers, an imaging plane, and blade scanning units that are the same in number as the lasers and are connected one-to-one through optical fibers, the N blade scanning units have N narrowband areas, each of the narrowband areas includes M identical scanning partitions, the N narrowband areas have N×M scanning partitions, and the edges of adjacent scanning partitions overlap, so as to cover the imaging plane, each narrowband area activates only one scanning partition at any time, and all narrowband areas activate at most N scanning partitions at the same time;

[0007] A scanning controller, the scanning controller is electrically connected to the blade scanning unit and the laser, and the scanning controller can send narrowband graphic data to each blade scanning unit in parallel, each of the blade scanning units includes a blade controller, and the blade controller is electrically connected to a collimator, an optical path switching mechanism, a zoom mechanism, and a galvanometer mechanism, respectively, and the optical path switching mechanism, the zoom mechanism, and the galvanometer mechanism can constitute M laser channels, and the collimated laser beam of the collimator only enters one laser channel at any time;

[0008] The optical path switching mechanism includes M reflection units, the reflection unit farthest from the collimator is a fixed reflection mirror, and the other reflection units are sliding reflection units. The switching of the M reflection units is mutually exclusive, which plays a role in switching laser channels. The zoom mechanism includes M zoom units, which plays a role in adjusting the laser focal length. The galvanometer mechanism includes M galvanometer units, which plays a role in scanning the laser beam.

[0009] Each of the laser channels comprises a reflection unit, a zoom unit and a galvanometer unit, and each of the blade scanning units also comprises a shell, a galvanometer mechanism is installed at the bottom of the shell, a zoom unit is installed above the light inlet of each galvanometer unit, the fixed convex lens group of the zoom unit coincides with the axis of the light inlet, the fixed convex lens group outputs a zoomed collimated laser beam pointing to the deflection reflector of the X-axis deflection assembly in the galvanometer unit, when the X-axis swing angle of the X-axis deflection assembly is at the center zero position, the focusing and scanning path of the collimated laser beam are completely in the normal plane of the scanning axis of the Y-axis deflection assembly projected onto the imaging plane, so that the X-axis of the X-axis deflection assembly is completely used for the X-axis scanning of the blade scanning unit and does not occupy the Y-axis redundant structure space, thereby realizing the ultra-thin state of the blade scanning unit;

[0010] A reflecting unit is installed above each zoom unit, and the angle between each reflecting unit and the axis of the light port of the collimator is 45°.

[0011] Furthermore, each of the zoom units includes a hollow linear module, an incident concave lens, a fixed convex lens group and a fixed seat, the fixed seat is fixedly installed in the shell, the fixed seat is equipped with a hollow linear module, the incident concave lens is installed at one end of the hollow linear module away from the optical path switching mechanism, and the fixed convex lens group is installed below the incident concave lens.

[0012] Furthermore, each of the galvanometer units includes an X-axis deflection assembly, a Y-axis deflection assembly orthogonal to the deflection axis of the X-axis deflection assembly, a light inlet, a light outlet and a deflection cover, wherein the X-axis deflection assembly and the Y-axis deflection assembly are separately installed inside the deflection cover, a light inlet is provided at the upper end of the deflection cover, and a light outlet is provided at the lower end, the light inlet is matched with a fixed convex lens group, and the light outlet is located above the imaging plane.

[0013] Furthermore, the X-axis deflection assembly and the Y-axis deflection assembly both include a deflection base, an integrated mirror frame and a rotation sensor, the two sides of the deflection base are integrally formed with an axis fixing plate, the axis fixing plate is embedded with a double bearing system, the two ends of the integrated mirror frame are sleeved in the double bearing system and one end is connected to the rotation sensor, a groove is opened in the middle of the deflection base, permanent magnets are installed on both sides of the groove, a deflection reflector is installed on the upper side of the integrated mirror frame and a moving coil is installed on the lower side, the moving coil can reciprocate between the permanent magnets, and an axial magnetic flux is formed between the moving coil and the permanent magnet.

[0014] Further, when M=3 and N=5, the reflecting unit includes a first reflecting mirror, a second reflecting mirror and a fixed reflecting mirror, the zoom units are respectively a first zoom unit, a second zoom unit and a third zoom unit, the galvanometer units are respectively a first galvanometer unit, a second galvanometer unit and a third galvanometer unit, each of the narrowband areas includes a first scanning partition, a second scanning partition and a third scanning partition, the lasers are respectively a first laser, a second laser, a third laser, a fourth laser and a fifth laser, and the blade scanning units are respectively a first blade scanning unit, a second blade scanning unit, a third blade scanning unit, a fourth blade scanning unit and a fifth blade scanning unit.

[0015] Furthermore, N of the laser linear arrays are installed as a laser group, and N of the blade scanning unit linear arrays are installed as a blade scanning unit group, and the laser group is connected in parallel with the blade scanning unit group.

[0016] Furthermore, each of the sliding reflection units includes a slide table, a reflection lens is fixed to the slide table, and the slide table is driven by a high-speed linear element. The movement and coordination of the plurality of sliding reflection units realizes the millisecond-level switching of the plurality of laser channels.

[0017] In another aspect, the present invention provides a scanning method, wherein the device used in the method includes the above-mentioned high-density, large-span, narrow-band aggregated laser scanning device, and the method includes:

[0018] Narrowband graphic data preprocessing: the scanning controller divides the graphic data into N narrowband graphic data with overlapping edges according to the position of the narrowband area of ​​each blade scanning unit on the imaging plane and sends the data to the blade controller of the corresponding blade scanning unit;

[0019] Scanning graphic data preprocessing: after each of the blade controllers receives the corresponding narrowband graphic data, it divides the data into M scanning graphic data with overlapping edges according to the positions of the M scanning partitions of each narrowband area on the imaging plane and matches them to the corresponding scanning partitions, and sets the scanning order of the M scanning partitions;

[0020] Scanning execution method: the blade controller analyzes the coordinates of each vector of the scanning graphic data, and locates a corresponding scanning partition according to the coordinate position of the vector, and the blade controller sends a work instruction to the reflection unit, zoom unit and galvanometer unit of the laser channel constituting the scanning partition, and the reflection unit receiving the instruction slides down to intercept the collimated laser beam of the collimator, and the zoom unit and galvanometer unit constituting the laser channel of the reflection unit perform linked multi-axis scanning, and synchronously sends a laser switch instruction and a power adjustment instruction to the matched laser, adjusts the output power of the laser to be consistent with the vector energy parameter, and controls the laser switch action to be aligned with the jump and scanning action of the galvanometer unit;

[0021] The switching of the M scanning partitions adopts a synchronous, light-off switching method: the zoom unit and the galvanometer unit in operation are executed in advance with the zoom unit and the galvanometer unit that are pre-entered into operation to perform a pre-synchronized zoom-scan linkage instruction, and the reflection unit in operation and the reflection unit that are pre-entered into operation then complete the vector data jump instruction during the laser light-off period to realize the switching of the reflection unit, so that the switching scanning between the scanning partitions is similar to the ordinary vector jump scanning, and has the characteristics of smoothness and no insertion interruption;

[0022] Decoupling correction of Y-axis coupling distortion: The blade controller performs decoupling correction to produce a slight and smooth continuous Y-axis coupling distortion in the imaging plane. The scanning laser beam surface developed by the X-axis swing of the X-axis deflection assembly is not parallel to the imaging plane, resulting in Y-axis coupling distortion in the imaging plane.

[0023] Furthermore, the scanning execution method specifically includes: the collimated laser beam of the collimator is reflected by the reflection unit to the zoom unit, input to the galvanometer unit after being focused by the zoom unit, and output to a corresponding scanning partition of the imaging plane after being deflected and reflected by the X-axis deflection assembly and the Y-axis deflection assembly. At any time, only one scanning partition among the M scanning partitions is activated. The hollow linear module of the zoom unit drives the incident concave lens to move back and forth along the linear direction of the optical axis to adjust the focal length of the collimated laser beam reflected by the reflection unit. The closer the incident concave lens is to the fixed convex lens group, the longer the focal length of the collimated laser beam, and vice versa.

[0024] Furthermore, the scanning graphic data preprocessing also includes two methods of setting the scanning order of M scanning partitions: the first setting method is to formulate the scanning order of the scanning partitions in the narrowband area according to the content analysis of the scanning graphic data and follow the principle of the shortest jump path; the second setting method is to dispatch multiple collimated laser beams across different narrowband areas, synchronously scan the scanning partitions in each narrowband area, and realize cross-area stitching scanning in the overlapping area in a concurrent or relay manner.

[0025] The present invention has the following beneficial effects: a scanning method

[0026] The present invention connects multiple blade scanning units and lasers in parallel, and each blade scanning unit has an array of reflection units, zoom units and galvanometer units. Each unit can be detachably installed to form multiple scanning partitions. According to the size of the imaging plane, the corresponding blade scanning units and the reflection units, zoom units and galvanometer units therein can be increased or decreased. It has a high degree of modularity and flexibility. The multiple scanning partitions can scan multiple areas or targets at the same time, which improves the scanning efficiency, coverage and accuracy. The working state of each scanning unit can also be dynamically adjusted according to the requirements of the scanning task. The scheme of the present invention has a reasonable layout, is easy to assemble, adjust and maintain, and has a fast response speed. It is easy to promote and apply in various medium and large-sized, high-precision, and high-efficiency laser powder bed three-dimensional forming equipment.

[0027] The X-axis deflection assembly and the Y-axis deflection assembly of the galvanometer unit of the present invention have the same optical and electromechanical parameters, and there is an axial magnetic flux linkage between the moving coil and the permanent magnet fixed iron. The galvanometer unit has the characteristics of flat axial dimension, thermal isolation between the moving coil and the integrated mirror frame, and the deflection torque acting on the center of the integrated mirror frame. The galvanometer unit is more balanced when subjected to force, and the vibration and noise caused by the unbalanced torque are reduced, and the accuracy and stability of the assembly are improved. The thermal isolation reduces the mechanical stress and thermal stress caused by temperature changes, and improves the reliability and durability of the deflection assembly. The two ends of the integrated mirror frame are connected to a double bearing system. The supporting rigidity and rotation accuracy are high, and the Y-axis coupling distortion phenomenon is reduced; when the X-axis swing angle of the X-axis deflection assembly is at the center zero position, the focusing and scanning path of the collimated laser beam are completely in the normal plane of the scanning axis of the Y-axis deflection assembly projected to the imaging plane, so that the X-axis of the X-axis deflection assembly is completely used for the X-axis scanning of the blade scanning unit to improve the scanning efficiency, and does not occupy the Y-axis redundant structure space to avoid the accuracy loss caused by space limitations, and realizes the compression of the blade scanning unit to an ultra-thin state that is significantly smaller than the traditional two-axis galvanometer, which provides a guarantee for high-density layout.

[0028] The multiple reflection units, zoom units and galvanometer units in each blade scanning unit of the present invention share the same collimated laser beam. The mutually exclusive working logic of the reflection units ensures that only a single laser beam is output to the narrowband area of ​​the blade scanning unit at any time, avoiding mutual interference and conflict between multiple laser beams in the same narrowband area, thereby realizing a large-span linear expansion of the scanning range.

[0029] The switching of multiple edge overlapping scanning partitions of the present invention adopts a combination of synchronization and light-off switching methods, which improves imaging quality, fast switching speed and high scanning efficiency, and also ensures the continuity and integrity of scanning data, effectively avoiding damage or interference of the laser beam to the scanned object. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions and advantages in the embodiments of the present invention or the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0031] Figure 1 A stereoscopic diagram of a high-density, large-span, narrow-band aggregation laser scanning device according to the present invention;

[0032] Figure 2 It is a structural schematic diagram of a blade scanning unit of the present invention;

[0033] Figure 3 It is a schematic diagram of the three-dimensional structure of the blade scanning unit of the present invention;

[0034] Figure 4 is a schematic cross-sectional structural diagram of a zoom unit of the present invention;

[0035] Figure 5 is a three-dimensional diagram of the galvanometer unit of the present invention;

[0036] Figure 6 It is a stereogram of the X-axis deflection assembly of the present invention;

[0037] Figure 7 It is a partial structural schematic diagram of the X-axis deflection assembly of the present invention;

[0038] Figure 8 A schematic diagram of a first scanning partition of each blade scanning unit of the present invention;

[0039] Fig. 9 A schematic diagram of a second scanning partition of each blade scanning unit of the present invention;

[0040] Fig.10 A schematic diagram of a third scanning partition of each blade scanning unit of the present invention;

[0041] Fig.11 A diagram showing the scanning process of multiple scanning partitions in the scanning method of the present invention;

[0042] Fig.12 A diagram showing a synchronous scanning process of multiple scanning partitions of the scanning method of the present invention;

[0043] Fig.13 This is a control logic diagram of the scanning method of the present invention.

[0044] 1. Cabinet; 2. Imaging plane; 3. Blade scanning unit; 3-1. First scanning partition; 3-2. Second scanning partition; 3-3. Third scanning partition; 3-123. Narrowband area; 301. Collimator; 302. Zoom unit; 303. Galvanometer unit; 304. Shell; 305. Fixed reflector; 306. Second reflector; 307. First reflector; 4. Laser; 5. Hollow linear module; 6. Incident concave lens; 7. Fixed convex lens group; 8. Fixed seat; 9. Y-axis deflection assembly; 10. Light inlet; 11. Deflection cover; 12. X-axis deflection assembly; 13. Light outlet; 14. Deflection base; 15. Double bearing system; 16. Integrated mirror frame; 17. Rotation sensor; 18. Moving coil; 19. Permanent magnet fixed iron; 20. Deflection reflector; 21. Axis fixing plate. DETAILED DESCRIPTION

[0045] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments.

[0046] Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making any creative work shall fall within the scope of protection of this application.

[0047] It should be noted that all directional indications in the embodiments of the present application (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0048] In this application, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0049] In addition, if there are descriptions involving "first", "second", "third", ... "Mth" or "Nth", etc. in the embodiments of the present application, then the descriptions of "first", "second", "third", ... "Mth" or "Nth", etc. are used for the convenience of description and may indicate the number of installations. The need for expansion of N and M is a limitation.

[0050] Please refer to Figure 1 The present embodiment provides a high-density, large-span narrow-band aggregation laser scanning device, including a cabinet 1, on which five lasers 4, an imaging plane 2 and blade scanning units 3, which are the same number as the lasers 4 and are connected one-to-one through optical fibers, are installed in sequence from bottom to top. The five blade scanning units 3 have five narrow-band areas 3-123, and the five narrow-band areas 3-123 overlap and cover the imaging plane 2 in sequence. Each narrow-band area 3-123 includes three scanning partitions, which are the first scanning partition 3-1, the second scanning partition 3-2 and the third scanning partition 3-3 in sequence. When the exhaust airflow direction of the device is consistent with the arrangement direction of the first scanning partition 3-1, the second scanning partition 3-2 and the third scanning partition 3-3, since only one of the first scanning partition 3-1, the second scanning partition 3-2 and the third scanning partition 3-3 is activated at any time, it is avoided that the smoke generated by the front scanning partition invades the laser beam space channel of the rear scanning partition, resulting in scanning defects such as energy attenuation and spot scattering.

[0051] The five lasers 4 are installed in a linear array and are in turn the first laser, the second laser, the third laser, the fourth laser, and the fifth laser. The five blade scanning units 3 are installed in a linear array and are in turn the first blade scanning unit, the second blade scanning unit, the third blade scanning unit, the fourth blade scanning unit, and the fifth blade scanning unit. The first laser and the first blade scanning unit, the second laser and the second blade scanning unit, the third laser and the third blade scanning unit, the fourth laser and the fourth blade scanning unit, and the fifth laser and the fifth blade scanning unit are connected by optical fibers. In addition to the aligned parallel layout in this embodiment, the arrangement of the five blade scanning units 3 can also be set as an offset or aligned layout scheme according to the actual width and 2D shape of the imaging plane 2.

[0052] See also Fig.12 and Fig. 9 , the first blade scanning unit, the second blade scanning unit, the third blade scanning unit, the fourth blade scanning unit and the fifth blade scanning unit all activate the second scanning partition 3-2, and the five second scanning partitions 3-2 are overlapped adjacent to each other in sequence and cover the imaging plane 2. The first, second, third, fourth and fifth blade scanning units can follow the principle of the shortest jump path according to the specific content of the scanning graphic data, and complete the scanning sequence of the first scanning partition 3-1, the second scanning partition 3-2, and the third scanning partition 3-3 of the narrowband area 3-123 in the best efficiency order, or they can schedule multiple collimated laser beams across the blade scanning units 3 to keep the first scanning partition 3-1, the second scanning partition 3-2, and the third scanning partition 3~3 scanning synchronously, and then perform cross-zone stitching scanning in the overlapping area in a concurrent or relay manner.

[0053] It should be particularly noted that the laser 4 and the blade scanning unit 3 can be deployed in parallel to N within the same imaging surface width range to achieve high-density, high-efficiency multi-laser beam aggregation scanning, the N lasers 4 are installed in a linear array and are in turn the first laser, the second laser... the Nth laser, the N blade scanning units 3 are installed in a linear array and are in turn the first blade scanning unit, the second blade scanning unit... the Nth blade scanning unit, the first laser and the first blade scanning unit, the second laser and the second blade scanning unit... the Nth laser and the Nth blade scanning unit are respectively connected by optical fibers, the N lasers 4 are installed in a linear array as a laser group, the N blade scanning units 3 are installed in a linear array as a blade scanning unit group, the laser group and the blade scanning unit group are connected in parallel, the N narrowband areas 3-123 are overlapped in sequence along the left and right directions of the imaging plane 2, so the area of ​​the imaging plane 2 is also expanded accordingly.

[0054] For further information, see Figure 8 , Fig. 9 and Fig.10Each narrowband area 3-123 includes three identical scanning partitions, which are the first scanning partition 3-1, the second scanning partition 3-2 and the third scanning partition 3-3, respectively. The five narrowband areas 3-123 have 15 scanning partitions. The edges of adjacent scanning partitions overlap, so as to cover the imaging plane 2. All narrowband areas 3-123 activate at most five scanning partitions at the same time at any time. At any time, each narrowband area 3-123 only activates the first scanning partition 3-1 or the second scanning partition 3-2 or the third scanning partition 3-3.

[0055] It should be particularly noted that as the laser channels in the scanning unit 3 are expanded to M, each narrowband area 3-123 can be expanded to M identical scanning partitions with a large span. The scanning partitions are overlapped along the front-to-back direction of the imaging plane 2. The N narrowband areas 3-123 have N×M scanning partitions. The edges of adjacent scanning partitions partially overlap, thereby covering the imaging plane 2. At any time, each narrowband area 3-123 only activates one scanning partition, and all narrowband areas 3-123 activate at most N scanning partitions at the same time, but the scanning partition activation is controlled by the blade controller.

[0056] For further information, see Fig.13 , Figure 2 and Figure 3 The device of the present invention also includes a scanning controller, which is electrically connected to the blade scanning unit 3 and the laser 4. The scanning controller can send narrowband graphic data to each blade scanning unit 3 in parallel. The blade scanning unit 3 includes a blade controller, which is electrically connected to the collimator 301, the optical path switching mechanism, the zoom mechanism and the galvanometer mechanism respectively. The optical path switching mechanism, the zoom mechanism and the galvanometer mechanism can constitute three laser channels. At any time, the collimated laser beam of the collimator 301 only enters one laser channel.

[0057] The optical path switching mechanism includes three reflecting units, namely the first reflecting mirror 307, the second reflecting mirror 306, and the third reflecting mirror. The first reflecting mirror 307 and the second reflecting mirror 306 are sliding, and the third reflecting mirror is a fixed reflecting mirror 305 and is farthest from the collimator 301. The switching of the three reflecting units is mutually exclusive and serves to switch the laser channels. The switching time of the first reflecting mirror 307, the second reflecting mirror 306 and the fixed reflecting mirror 305 to distribute the collimated laser beam is in milliseconds.

[0058] It should be particularly noted that as the laser channels in each blade scanning unit 3 are expanded to M, the optical path switching mechanism includes M reflection units, the reflection unit farthest from the collimator 301 is a fixed reflector 305, and the other reflection units are sliding reflector units. The switching of the M reflection units is mutually exclusive. Each sliding reflector unit includes a slide table, and a reflective lens is fixed on the slide table. The slide table is driven by a high-speed linear element. Multiple sliding reflector units move and cooperate to achieve millisecond-level switching of multiple laser channels.

[0059] The zoom mechanism includes three zoom units 302, which are the first zoom unit, the second zoom unit and the third zoom unit, respectively, and play the role of adjusting the laser focal length. The galvanometer mechanism includes three galvanometer units 303, which are the first galvanometer unit, the second galvanometer unit and the third galvanometer unit, respectively, and play the role of laser beam scanning. The first reflector 307, the first zoom unit and the first galvanometer unit constitute a first laser channel, thereby realizing the laser channel of the first scanning partition 3-1. The second reflector 306, the second zoom unit and the second galvanometer unit constitute a second laser channel, thereby realizing the laser channel of the second scanning partition 3-2. The fixed reflector 305, the third zoom unit and the third galvanometer unit constitute a third laser channel, thereby realizing the laser channel of the third scanning partition 3-3.

[0060] The first reflector 307 and the second reflector 306 have the same structure and both include a slide, on which a reflector lens is fixed. The first reflector 307 and the second reflector 306 move and cooperate to realize the switching of the three laser channels. At any time, the collimated laser beam of the collimator 301 only enters one laser channel. The drive of the slide can adopt high-speed linear elements such as high electromagnetic coils, air pressure drive, liquid-gas linkage, piezoelectric, etc.

[0061] It should be noted that as the laser channels in the scanning unit 3 are expanded to M, the reflection unit, the zoom unit 302 and the galvanometer unit 303 will also be deployed in parallel to M, forming M laser channels, so that each scanning partition in each narrowband area 3-123 has a laser channel, that is, each laser channel includes a reflection unit, a zoom unit 302 and a galvanometer unit 303. At the same time, the zoom mechanism also includes M zoom units 302, which are the first zoom unit, the second zoom unit, the third zoom unit...the Mth zoom unit in sequence, and the galvanometer mechanism includes M galvanometer units 303, which are the first galvanometer unit, the second galvanometer unit, the third galvanometer unit...the Mth galvanometer unit in sequence.

[0062] For further information, see Figures 2 to 5Each blade scanning unit 3 also includes a shell 304, a galvanometer mechanism is installed at the bottom of the shell 304, a zoom unit 302 is installed above the light entrance 10 of each galvanometer unit 303, the fixed convex lens group 7 of the zoom unit 302 coincides with the axis of the light entrance 10, the fixed convex lens group 7 outputs the zoomed collimated laser beam to point to the deflection reflector 20 of the X-axis deflection assembly 12 in the galvanometer unit 303, when the X-axis swing angle of the X-axis deflection assembly 12 is at the center zero position, the focusing and scanning path of the collimated laser beam are completely in the normal plane of the Y-scanning axis of the Y-axis deflection assembly 9 projected onto the imaging plane 2, so that the X-axis of the X-axis deflection assembly 12 is completely used for the X-axis scanning of the blade scanning unit 3 and does not occupy the Y-axis redundant structural space, so as to realize the ultra-thin state of the blade scanning unit 3, a reflection unit is installed above each zoom unit 302, and the angle between each reflection unit and the axis of the light entrance of the collimator 301 is 45°.

[0063] For further information, see Figures 2 to 7 Each zoom unit 302 includes a hollow linear module 5, an incident concave lens 6, a fixed convex lens group 7 and a fixed seat 8. The fixed seat 8 is fixedly installed in the housing 304. The fixed seat 8 is equipped with a hollow linear module 5. The incident concave lens 6 is installed at the moving end of the hollow linear module 5 away from the optical path switching mechanism, and the fixed convex lens group 7 is installed below the incident concave lens 6.

[0064] Each galvanometer unit 303 includes an X-axis deflection assembly 12, a Y-axis deflection assembly 9 orthogonal to the deflection axis of the X-axis deflection assembly 12, a light inlet 10, a light outlet 13 and a deflection cover 11. The X-axis deflection assembly 12 and the Y-axis deflection assembly 9 are separately installed inside the deflection cover 11. The deflection cover 11 has a light inlet 10 at the upper end and a light outlet 13 at the lower end. The light inlet 10 matches the fixed convex lens group 7, and the light outlet 13 is located above the imaging plane 2.

[0065] It should be particularly noted that, as the laser channels are expanded to M, the M zoom units 302 have the same structure, the M galvanometer units 303 have the same structure, and the X-axis deflection assembly 12 and the Y-axis deflection assembly 9 have the same structure.

[0066] For further information, see Figure 6 to Figure 7The X-axis deflection assembly 12 and the Y-axis deflection assembly 9 both include a deflection base 14, an integrated mirror frame 16 and a rotation sensor 17. The two sides of the deflection base 14 are integrally formed with shaft fixing plates 21, and the shaft fixing plates 21 are embedded with a double bearing system 15. Both ends of the integrated mirror frame 16 are sleeved in the double bearing system 15 and one end is connected to the rotation sensor 17. A groove is opened in the middle of the deflection base 14, and permanent magnets 19 are installed on both sides of the groove. A deflection reflector 20 is installed on the upper side of the integrated mirror frame 16 and a moving coil 18 is installed on the lower side. The moving coil 18 can reciprocate on the permanent magnet 19, and there is an axial magnetic flux between the moving coil 18 and the permanent magnet 19. It has the characteristics of flat axial dimension, thermal isolation between the moving coil 18 and the integrated mirror frame 16, and the deflection torque acts on the center of the integrated mirror frame 16.

[0067] In another aspect, the present invention provides a scanning method, wherein the device used in the method includes the above-mentioned high-density, large-span narrow-band aggregate laser scanning device, and the method includes:

[0068] Narrowband graphic data preprocessing: the scanning controller divides the graphic data into N narrowband graphic data with overlapping edges according to the position of the narrowband area 3-123 of each blade scanning unit 3 on the imaging plane 2 and sends them to the blade controller of the corresponding blade scanning unit 3;

[0069] Scanning graphic data preprocessing: After each blade controller receives the corresponding narrowband graphic data, it divides it into M scanning graphic data with overlapping edges according to the positions of the M scanning partitions of each narrowband area 3-123 on the imaging plane 2 and matches them to the corresponding scanning partitions, and sets the scanning order of the M scanning partitions;

[0070] Scanning execution method: the blade controller analyzes the coordinates of each vector of the scanning graphic data, and locates a corresponding scanning partition according to the coordinate position of the vector, and the blade controller sends a work instruction to the reflection unit, zoom unit 302 and galvanometer unit 303 of the laser channel constituting the scanning partition, and a reflection unit receiving the instruction slides down to intercept the collimated laser beam of the collimator 301, and the zoom unit 302 and galvanometer unit 303 constituting the laser channel of the reflection unit perform linked multi-axis scanning, and synchronously sends a laser switch instruction and a power adjustment instruction to the matched laser 4, adjusts the output power of the laser 4 to be consistent with the vector energy parameter, and controls the switching action of the laser 4 to align with the jump and scanning action of the galvanometer unit 303;

[0071] The switching of the M scanning partitions adopts a synchronous, light-off switching method: the zoom unit 302 and the galvanometer unit 303 in operation are executed in advance with the zoom unit 302 and the galvanometer unit 303 in the pre-operation to execute the pre-synchronized zoom-scan linkage instruction, and the reflection unit in operation and the reflection unit in the pre-operation further complete the vector data jump instruction during the light-off period of the laser 4 to realize the switching of the reflection unit, so that the switching scanning between the scanning partitions is similar to the ordinary vector jump scanning, and has the characteristics of smoothness and no insertion interruption;

[0072] Decoupling correction of Y-axis coupling distortion: The blade controller performs decoupling correction to produce a slight and smooth continuous Y-axis coupling distortion on the imaging plane 2. The scanning laser beam surface unfolded by the X-axis swing of the X-axis deflection assembly 12 is not parallel to the imaging plane 2, resulting in Y-axis coupling distortion on the imaging plane 2.

[0073] Further, each galvanometer unit 303 includes a Y-axis deflection assembly 9 and an X-axis deflection assembly 12 which are orthogonal to the deflection axis of the X-axis deflection assembly 12; each zoom unit 302 includes a hollow linear module 5, an incident concave lens 6 and a fixed convex lens group 7;

[0074] The scanning execution method specifically includes: the collimated laser beam of the collimator 301 is reflected by the reflection unit to the zoom unit 302, input to the galvanometer unit 303 after being focused by the zoom unit 302, and output to a corresponding scanning partition of the imaging plane 2 after being deflected and reflected by the X-axis deflection component 12 and the Y-axis deflection component 9. At any time, only one scanning partition is activated among the M scanning partitions. The hollow linear module 5 of the zoom unit 302 drives the incident concave lens 6 to move back and forth along the straight line direction of the optical axis to adjust the focal length of the collimated laser beam reflected by the reflection unit. The closer the incident concave lens 6 is to the fixed convex lens group 7, the longer the focal length of the collimated laser beam, and vice versa.

[0075] Furthermore, the scanning graphic data preprocessing also includes two methods of setting the scanning order of M scanning partitions: the first setting method is to formulate the scanning order of the scanning partitions in the narrowband area 3-123 according to the content analysis of the scanning graphic data and follow the principle of the shortest jump path; the second setting method is to dispatch multiple collimated laser beams across different narrowband areas 3-123, and synchronously scan the scanning partitions in each narrowband area 3-123, so as to realize cross-area stitching scanning in the overlapping area in a concurrent or relay manner.

Claims

1. A high-density, large-span, narrow-band aggregation laser scanning device, characterized in that: include: A cabinet (1), wherein the cabinet (1) is provided with N lasers (4), an imaging plane (2), and blade scanning units (3) having the same number as the lasers (4) and connected one-to-one via optical fibers in order from bottom to top, wherein the N blade scanning units (3) have N narrowband areas (3-123), each of the narrowband areas (3-123) includes M identical scanning partitions, the N narrowband areas (3-123) have N×M scanning partitions, and the edges of adjacent scanning partitions partially overlap, thereby covering the imaging plane (2), and at any time, each narrowband area (3-123) activates only one scanning partition, and all narrowband areas (3-123) activate at most N scanning partitions at the same time; a scanning controller, the scanning controller being electrically connected to the blade scanning unit (3) and the laser (4), the scanning controller being capable of sending narrowband graphic data to each blade scanning unit (3) in parallel, each blade scanning unit (3) comprising a blade controller, the blade controller being electrically connected to a collimator (301), an optical path switching mechanism, a zoom mechanism and a galvanometer mechanism respectively, the optical path switching mechanism, the zoom mechanism and the galvanometer mechanism being capable of forming M laser channels, and the collimated laser beam of the collimator (301) only enters one laser channel at any time; The optical path switching mechanism comprises M reflection units, the reflection unit farthest from the collimator (301) is a fixed reflection mirror (305), and the other reflection units are sliding reflection units, the switching of the M reflection units is mutually exclusive, and serves to switch the laser channels, the zoom mechanism comprises M zoom units (302), and serves to adjust the laser focal length, and the galvanometer mechanism comprises M galvanometer units (303), and serves to scan the laser beam flatly; Each of the laser channels comprises a reflection unit, a zoom unit (302) and a galvanometer unit (303); each of the blade scanning units (3) further comprises a housing (304); a galvanometer mechanism is installed at the bottom of the housing (304); a zoom unit (302) is installed above the light entrance (10) of each of the galvanometer units (303); a fixed convex lens group (7) of the zoom unit (302) coincides with the axis of the light entrance (10); the fixed convex lens group (7) outputs a zoomed The collimated laser beam is directed to the deflection reflector (20) of the X-axis deflection assembly (12) in the galvanometer unit (303); when the X-axis swing angle of the X-axis deflection assembly (12) is at the center zero position, the focusing and scanning path of the collimated laser beam are completely within the normal plane of the projection of the scanning axis of the Y-axis deflection assembly (9) onto the imaging plane (2), so that the X-axis of the X-axis deflection assembly (12) is completely used for X-axis scanning of the blade scanning unit (3) and does not occupy the Y-axis redundant structure space, thereby realizing the ultra-thin state of the blade scanning unit (3); A reflection unit is installed above each zoom unit (302), and the angle between each reflection unit and the optical port axis of the collimator (301) is 45°.

2. The high-density, large-span, narrow-band converged laser scanning device according to claim 1, characterized in that: Each zoom unit (302) comprises a hollow linear module (5), an incident concave lens (6), a fixed convex lens group (7) and a fixed seat (8); the fixed seat (8) is fixedly mounted in a housing (304); the fixed seat (8) is fitted with a hollow linear module (5); an incident concave lens (6) is mounted at one end of the hollow linear module (5) away from the optical path switching mechanism; and a fixed convex lens group (7) is mounted below the incident concave lens (6).

3. The high-density, large-span, narrow-band aggregation laser scanning device according to claim 2, characterized in that: Each of the galvanometer units (303) comprises an X-axis deflection assembly (12), a light inlet (10) of a Y-axis deflection assembly (9) orthogonal to the deflection axis of the X-axis deflection assembly (12), a light outlet (13) and a deflection cover (11); the X-axis deflection assembly (12) and the Y-axis deflection assembly (9) are separately installed inside the deflection cover (11); the deflection cover (11) has a light inlet (10) at its upper end and a light outlet (13) at its lower end; the light inlet (10) matches a fixed convex lens group (7); and the light outlet (13) is located above the imaging plane (2).

4. The high-density, large-span, narrow-band aggregation laser scanning device according to claim 3, characterized in that: The X-axis deflection assembly (12) and the Y-axis deflection assembly (9) both comprise a deflection base (14), an integrated mirror frame (16) and a rotation sensor (17); shaft fixing plates (21) are integrally formed on both sides of the deflection base (14); a double bearing system (15) is embedded in the shaft fixing plate (21); both ends of the integrated mirror frame (16) are sleeved in the double bearing system (15) and one end is connected to the rotation sensor (17); a groove is provided in the middle of the deflection base (14); permanent magnets (19) are installed on both sides of the groove; a deflection reflector (20) is installed on the upper side of the integrated mirror frame (16) and a moving coil (18) is installed on the lower side; the moving coil (18) can reciprocate between the permanent magnets (19); an axial magnetic flux is formed between the moving coil (18) and the permanent magnets (19).

5. A high-density, large-span, narrow-band converged laser scanning device according to any one of claims 1 to 4, characterized in that: When M=3 and N=5, the reflection unit comprises a first reflection mirror (307), a second reflection mirror (306) and a fixed reflection mirror (305); the zoom unit (302) is respectively a first zoom unit, a second zoom unit and a third zoom unit; the galvanometer unit (303) is respectively a first galvanometer unit, a second galvanometer unit and a third galvanometer unit; each narrowband area (3-123) comprises a first scanning partition (3-1), a second scanning partition (3-2) and a third scanning partition (3-3); the lasers (4) are respectively a first laser, a second laser, a third laser, a fourth laser and a fifth laser; and the blade scanning units (3) are respectively a first blade scanning unit, a second blade scanning unit, a third blade scanning unit, a fourth blade scanning unit and a fifth blade scanning unit; The first reflector (307), the first zoom unit and the first galvanometer unit form a first laser channel, thereby realizing the laser channel of the first scanning partition (3-1); the second reflector (306), the second zoom unit and the second galvanometer unit form a second laser channel, thereby realizing the laser channel of the second scanning partition (3-2); the fixed reflector (305), the third zoom unit and the third galvanometer unit form a third laser channel, thereby realizing the laser channel of the third scanning partition (3-3).

6. A high-density, large-span, narrow-band aggregation laser scanning device according to any one of claims 1 to 4, characterized in that: N of the lasers (4) are installed in a linear array as a laser group, and N of the blade scanning units (3) are installed in a linear array as a blade scanning unit group. The laser group and the blade scanning unit group are connected in parallel.

7. A high-density, large-span, narrow-band converged laser scanning device according to any one of claims 1 to 4, characterized in that: Each of the sliding reflection units comprises a slide table, a reflection lens is fixed on the slide table, and a high-speed linear element is used to drive the slide table. The movement and coordination of the plurality of sliding reflection units realizes the millisecond-level switching of the plurality of laser channels.

8. A scanning method, characterized in that: The method is performed by using the device according to any one of claims 1 to 4, and comprises: Narrowband graphic data preprocessing: the scanning controller divides the graphic data into N narrowband graphic data with overlapping edges according to the position of the narrowband area (3-123) of each blade scanning unit (3) on the imaging plane (2), and sends the data to the blade controller of the corresponding blade scanning unit (3); Scanning graphic data preprocessing: after each of the blade controllers receives the corresponding narrowband graphic data, it divides the data into M scanning graphic data with overlapping edges according to the positions of the M scanning partitions of each narrowband area (3-123) on the imaging plane (2), matches the data to the corresponding scanning partitions, and sets the scanning order of the M scanning partitions; Scanning execution method: the blade controller analyzes the coordinates of each vector of the scanning graphic data, and locates a corresponding scanning partition according to the coordinate position of the vector, and the blade controller sends a working instruction to the reflection unit, zoom unit (302) and galvanometer unit (303) of the laser channel constituting the scanning partition, and one of the reflection units receiving the instruction slides down to intercept the collimated laser beam of the collimator (301), and the zoom unit (302) and galvanometer unit (303) constituting the laser channel with the reflection unit perform linked multi-axis scanning, and synchronously sends a laser switch instruction and a power adjustment instruction to the matching laser (4), adjusts the output power of the laser (4) to be consistent with the vector energy parameter, and controls the switching action of the laser (4) to be aligned with the jump and scanning action of the galvanometer unit (303); The switching of the M scanning partitions adopts a synchronous, light-off switching method: the zoom unit (302) and the galvanometer unit (303) in operation are executed in advance with the zoom unit (302) and the galvanometer unit (303) in pre-operation to execute a pre-synchronized zoom-scan linkage instruction, and the reflection unit in operation and the reflection unit in pre-operation then complete a vector data jump instruction during the light-off period of the laser (4), thereby realizing the switching of the reflection unit, so that the switching scanning between the scanning partitions is similar to the ordinary vector jump scanning, and has the characteristics of smoothness and no insertion interruption; Decoupling correction of Y-axis coupling distortion: The blade controller decouples and corrects Y-axis coupling distortion with slight amplitude and smooth continuous.

9. A scanning method according to claim 8, characterized in that: Each of the galvanometer units (303) comprises a Y-axis deflection assembly (9) and an X-axis deflection assembly (12) which are orthogonal to the deflection axis of the X-axis deflection assembly (12); Each of the zoom units (302) comprises a hollow linear module (5), an incident concave lens (6) and a fixed convex lens group (7); The scanning execution method specifically comprises: the collimated laser beam of the collimator (301) is reflected by a reflection unit to a zoom unit (302), input to a galvanometer unit (303) after being focused by the zoom unit (302), and output to a corresponding scanning partition of an imaging plane (2) after being deflected and reflected by an X-axis deflection assembly (12) and a Y-axis deflection assembly (9), wherein only one scanning partition is activated among M scanning partitions at any time, and the hollow linear module (5) of the zoom unit (302) drives the incident concave lens (6) to move back and forth along the linear direction of the optical axis to adjust the focal length of the collimated laser beam reflected by the reflection unit; the closer the incident concave lens (6) is to the fixed convex lens group (7), the longer the focal length of the collimated laser beam, and vice versa.

10. A scanning method according to claim 8, characterized in that: The scanning graphic data preprocessing also includes two ways of setting the scanning order of the M scanning partitions: the first setting method is to formulate the scanning order of the scanning partitions in the narrowband area (3-123) according to the content analysis of the scanning graphic data and follow the principle of the shortest jump path; the second setting method is to dispatch multiple collimated laser beams across different narrowband areas (3-123) and synchronously scan the scanning partitions in each narrowband area (3-123), so as to realize cross-area stitching scanning in a concurrent or relay manner in the overlap area.

Images