Galvanometer scanning mechanism adjusting and calibrating instrument

Abstract

The invention belongs to the technical field of galvanometer deflection angle testing, and particularly relates to a galvanometer scanning mechanism adjusting instrument which comprises an optical platform, and a laser, a multifunctional switching table, a galvanometer fixing seat, a galvanometer control box, a collimator, a detector assembly, a display terminal and a collimator support which are arranged on the optical platform. A galvanometer scanning mechanism is fixed through a galvanometer fixing seat, a laser and a galvanometer control box are connected, the levelness of the galvanometer scanning mechanism is guaranteed, the center of a reflective mirror of the galvanometer scanning mechanism is basically aligned with the center of a reticle of a collimator, and after electrification, the galvanometer control box controls the scanning angle and frequency of the galvanometer scanning mechanism. And the display terminal performs imaging and measures the scanning angle, the left-right symmetry degree and the scanning zero position of the galvanometer scanning mechanism. The device is wide in application and flexible in adjustment, can visually detect the relation between the rotating angle of the galvanometer scanner and the driving voltage and frequency, and can effectively improve the working efficiency of detection and calibration of the galvanometer when the galvanometer is used.

Description

Technical Field

[0001] The invention belongs to the technical field of galvanometer deflection angle testing, and in particular relates to a galvanometer scanning mechanism calibration instrument. Background Art

[0002] The galvanometer is an excellent vector scanning device. It is a special swing motor. Its working principle is to use the torque generated by the energized coil in the magnetic field. However, due to the reset torque added to the rotor, the galvanometer can only deflect but not rotate.

[0003] When using a galvanometer as the core component of laser scanning, it is often necessary to calibrate the scanning angle and driving voltage of the galvanometer, so as to accurately control the scanning range and position of the galvanometer by adjusting the driving voltage. In the past, the deflection angle of the galvanometer was indirectly reflected by measuring the position feedback voltage. The function was relatively simple, and it was impossible to directly detect the relationship between the rotation angle of the galvanometer scanner and the driving voltage and frequency, resulting in low efficiency in its detection and calibration when using the galvanometer.

[0004] Therefore, those skilled in the art are in urgent need of developing a new galvanometer scanning mechanism calibration instrument. Summary of the invention

[0005] The purpose of the present invention is to provide a galvanometer scanning mechanism calibrator, which directly tests the galvanometer deflection angle through point light source projection, and is used to intuitively detect the relationship between the rotation angle of the galvanometer scanner and the driving voltage and frequency, thereby effectively improving the efficiency of its detection and calibration when using the galvanometer.

[0006] In order to achieve the above-mentioned object of the invention, the present invention proposes the following technical solutions:

[0007] A galvanometer scanning mechanism calibration instrument, comprising an optical platform, on which are provided:

[0008] Laser: can generate parallel point light sources and adjust the intensity of the light source to meet the detection needs of the detector;

[0009] Multifunctional transfer table: used to transfer and fix the galvanometer to be tested, so as to carry out relevant performance index tests;

[0010] Galvanometer fixing seat: used to realize 45° tilt fixing of single-axis galvanometer mirror and vertical cross fixing of dual-axis galvanometer;

[0011] Galvanometer control box: used to generate the input signal required for the test and control the galvanometer to generate the corresponding deflection angle and yaw frequency;

[0012] Collimator: It is used to collimate the laser beam after being deflected by the galvanometer so that it can be projected onto the graticule inside the collimator and be normally detected and received by the detector assembly.

[0013] Detector assembly: used to detect 650nm red light and 980nm and 1060nm infrared light, and then display the motion trajectory of the laser point. It has an electronic graticule to measure the scanning range and evaluate the scanning field range and the symmetry of the light spot.

[0014] Display terminal: used to display the image received by the detector assembly for real-time observation;

[0015] Collimator bracket: used to place the collimator and adjust the height and azimuth of the collimator to achieve aiming at the target.

[0016] Preferably, the galvanometer control box has an electronic touch screen, which can generate a scanning signal for driving the galvanometer according to the frequency and amplitude set by the user.

[0017] Preferably, the detector assembly includes a right-angle prism assembly, a projection objective assembly and a CMOS photodetector, the projection objective assembly is arranged between the right-angle prism assembly and the CMOS photodetector, the right-angle prism assembly includes a right-angle prism adjustment mechanism and a right-angle prism, the right-angle prism adjustment mechanism can realize the pitch and rotation adjustment of the right-angle prism reflection surface, the projection objective assembly includes three groups of glued lenses, wherein the two groups of glued lenses at both ends are provided with radially positionable threaded adjustment frames, and the CMOS photodetector is adjustably connected to the projection objective assembly front and back.

[0018] Preferably, the graticule adopts a frosted glass substrate and is engraved with crosshairs and spot scanning boundary lines, which can meet a scanning range of ±4.3°.

[0019] Preferably, the electronic scale lines of the CMOS photodetector are precisely engraved, and the minimum resolution angle is less than 30″.

[0020] Preferably, the collimator comprises an objective lens assembly, a beam splitter prism assembly, a graticule assembly and an illumination assembly; the objective lens assembly comprises an objective lens frame, a lens, a lens spacer ring and a framed attenuation plate; the beam splitter prism of the beam splitter prism assembly can achieve a radial posture of ±3° in the optical path; the graticule assembly comprises a graticule adjustment mechanism and a graticule; the graticule adjustment mechanism can achieve front and rear position and forward adjustment of the graticule; the illumination assembly comprises frosted glass, a reflective cup and a bulb; and the illumination assembly and the graticule assembly are fixedly connected by a buckle for easy disassembly and assembly.

[0021] Preferably, the graticule adjustment mechanism includes an inner adjustment ring and an outer adjustment ring, the inner adjustment ring is threadedly connected to the inner side of the outer adjustment ring, the graticule is threadedly connected to the inner side of the inner adjustment ring through an outer frame, and the outer frame of the graticule is in a shaft-hole matching form to ensure that no obvious graticule jump occurs during the rotation of the graticule.

[0022] Preferably, the collimator bracket comprises a front bracket and a rear bracket, and both sides of the bottom of the front bracket and the rear bracket are provided with adjustable feet, and the adjustable feet can be adjusted in height by adjusting knobs.

[0023] The present invention also includes other devices or components that can enable the galvanometer scanning mechanism calibration instrument to operate normally, all of which are conventional technical means in the field. In addition, the devices or components not limited in the present invention all adopt conventional means in the prior art.

[0024] The working principle of the present invention is: fix the galvanometer scanning mechanism through the galvanometer fixing seat and connect the laser and the galvanometer control box to ensure the level of the galvanometer scanning mechanism, so that the center of the reflector of the galvanometer scanning mechanism is basically aligned with the center of the graticule of the parallel light tube; after power-on, the galvanometer control box controls the scanning angle and frequency of the galvanometer scanning mechanism, displays the terminal imaging and measures the scanning angle of the galvanometer scanning mechanism, as well as the left-right symmetry and the scanning zero position, and adjusts the relevant parameters of the galvanometer scanning mechanism driving board until the relevant parameters of the galvanometer scanning mechanism meet the use requirements.

[0025] Compared with the prior art, the present invention has the following advantages:

[0026] 1) It has a wide range of applications and can realize single galvanometer motor scanning performance test, including scanning field of view, zero position drift, scanning symmetry and other index tests; realize dual galvanometer motor consistency test, including scanning deflection consistency, zero position consistency and other performance tests; realize stripe spot modulation information field performance test, including cross spot symmetry, cross scanning field symmetry and other performance tests.

[0027] 2) Flexible adjustment: the relative horizontal position of the graticule lines of the present application can be adjusted, the attenuation plate at the front end of the detector can be flexibly replaced, and the height and level of the parallel light tube bracket can be adjusted.

[0028] In summary, the present invention has a wide range of uses and flexible adjustment. It directly tests the galvanometer deflection angle by projecting a point light source, and can intuitively detect the relationship between the rotation angle of the galvanometer scanner and the driving voltage and frequency, which can effectively improve the efficiency of its detection and calibration when using the galvanometer. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0030] Figure 1 Schematic diagram of the overall structure of the galvanometer scanning mechanism calibration instrument in an embodiment of the present invention.

[0031] Figure 2 Optical system diagram of the galvanometer scanning mechanism calibration instrument in an embodiment of the present invention.

[0032] Figure 3Schematic diagram of the graticule form in an embodiment of the present invention.

[0033] Figure 4 Schematic diagram of electronic scale markings in an embodiment of the present invention.

[0034] Figure 5 Assembly structure diagram of the collimator and detector assembly in an embodiment of the present invention.

[0035] Figure 6 A schematic structural diagram of a beam splitter prism assembly in an embodiment of the present invention.

[0036] Figure 7 Schematic diagram of the graticule adjustment structure in an embodiment of the present invention.

[0037] Figure 8 A schematic diagram of the structure of a lighting assembly in an embodiment of the present invention.

[0038] Fig. 9 A schematic diagram of the structure of a detector assembly in an embodiment of the present invention.

[0039] Fig.10 Schematic diagram of the collimator bracket structure in an embodiment of the present invention.

[0040] Fig.11 Electrical connection diagram of the galvanometer scanning mechanism calibration instrument in an embodiment of the present invention.

[0041] Fig.12 A schematic structural diagram of a galvanometer control box in an embodiment of the present invention.

[0042] Fig.13 A functional block diagram of a control panel in an embodiment of the present invention. DETAILED DESCRIPTION

[0043] The present invention is described clearly below in conjunction with the drawings and specific embodiments in the embodiments of the present invention. The description herein is only used to explain the present invention, but is not intended to limit the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work, any modifications, equivalent substitutions, improvements, etc., should be included in the protection scope of the present invention.

[0044] Example

[0045] like Figures 1-2 As shown, this embodiment proposes a galvanometer scanning mechanism calibration instrument, including an optical platform 1, on which are provided:

[0046] Laser 2: can generate parallel point light sources and can adjust the light source intensity to meet the detection requirements of the detector;

[0047] Multifunctional transfer table 3: used to transfer and fix the galvanometer under test so as to carry out relevant performance index tests; the multifunctional transfer table can meet the needs of fixing single-axis galvanometer brackets and dual-axis galvanometer brackets, and can realize plane adjustment and horizontal displacement functions. A high-precision, multi-degree-of-freedom turntable with appropriate displacement is selected, and the above functions are realized in conjunction with the galvanometer fixing seat.

[0048] Galvanometer fixing seat 4: It is arranged on the multifunctional transfer table and is used to realize the 45° tilt fixing of the single-axis galvanometer mirror surface and the vertical cross fixing of the dual-axis galvanometer mirror;

[0049] Galvanometer control box 5: used to generate the input signal required for the test and control the galvanometer to generate the corresponding deflection angle and yaw frequency;

[0050] Collimator 6: used to collimate the laser beam deflected by the galvanometer so that it is projected onto the graticule inside the collimator and can be normally detected and received by the detector assembly.

[0051] Detector component 7: used to detect 650nm red light and 980nm and 1060nm infrared light, and then display the motion trajectory of the laser point. It has an electronic graticule that can measure the scanning range and evaluate the scanning field range and the symmetry of the light spot;

[0052] Display terminal 8: used to display the image received by the detector assembly for real-time observation;

[0053] Collimator bracket 9: used to place the collimator and adjust the height and azimuth of the collimator to achieve aiming at the target.

[0054] The collimator of the present invention adopts the design concept of wide-band autocollimation objective lens, which can take into account the red light 640nm and can also detect the commonly used laser wavelengths such as 980nm, 1060nm, etc., and adopts CMOS detector for the scanning range of not less than ±4° of the galvanometer. At the same time, the autocollimation objective lens can be used to correct the optical axis of the visible light aiming channel and the consistency of the laser and the daytime aiming optical axis. In this embodiment, the electronic division is precisely engraved, and the minimum resolution angle is less than 30".

[0055] In this embodiment, the scanning angle of the galvanometer is not less than ±4°, the working distance between the object to be measured and the collimating lens in the parallel light tube is 300 mm, and the aperture of the collimating lens is 100 mm.

[0056] In this embodiment, the minimum resolution of the collimator is calculated as follows:

[0057]

[0058] Where:

[0059] α-central resolution of the field of view, (″), K-numerical coefficient, D-effective diameter, mm.

[0060] Among them, the precision measuring instrument takes K = 1.20, the effective diameter D = 80mm, and it can be obtained:

[0061]

[0062] Specifically, the reticle uses a frosted glass substrate and is engraved with crosshairs and spot scanning boundary lines. The reticle is in the form of Figure 3 As shown. After calculation, when the focal length of the collimating objective lens is f = 400mm, the imaging surface is designed to be 50×50mm 2 The graticule screen can meet the scanning range of ±4.3°.

[0063] More specifically, in this embodiment, the focal length of the objective lens is f=400 mm, the scanning width at the graticule is 50 mm, the graticule is projected onto the detector image plane through the differentiation projection system, a CMOS detector with a detection target surface of 1 inch and a resolution of 3840×2160 is selected, and a differentiation line is engraved every 4 pixels by superimposing electronic graticules (such as Figure 4 As shown in Figure 2), the minimum resolution angle α can be calculated to be 28.67″.

[0064] In this embodiment, the collimator and the detector assembly are collectively referred to as a projection detector assembly. The projection detector assembly is the core part of the galvanometer scanning calibration instrument, which mainly realizes the precise projection and imaging display of the scanning field, and measures the scanning range by etching division + electronic division. It is mainly composed of an objective lens assembly 10, a beam splitter prism assembly 11, a division plate assembly 12, an illumination assembly 13, a detector assembly and a support assembly. Its structural composition is as follows: Figure 5 The objective lens assembly is composed of an objective lens frame, a lens and a lens spacer, and also includes a framed attenuation sheet 14. This part is relatively large in size, has a large number of lenses, and has no design adjustment link. After the parts are inspected and qualified, they are directly assembled according to the drawings.

[0065] like Figure 6 As shown, the beam splitter prism assembly is mainly used to adjust the radial posture of the beam splitter prism in the optical path, and cooperates with the right-angle prism adjustment structure in the detector assembly to make joint adjustments so that the detection optical axis and the optical axis of the parallel light tube optical system are consistent and parallel.

[0066] like Figure 7As shown, the graticule plate assembly includes a graticule plate adjustment mechanism and a graticule plate 25. The graticule plate adjustment mechanism can realize the front and rear position and positive adjustment of the graticule plate, and the above-mentioned adjustment function is realized by adopting an adjustment ring with different inner and outer pitches. Specifically, the graticule plate adjustment mechanism includes an inner adjustment ring 15 and an outer adjustment ring 16. The inner adjustment ring is threadedly connected to the inner side of the outer adjustment ring, and the graticule plate is threadedly connected to the inner side of the inner adjustment ring through an outer frame, and the outer frame of the graticule plate is in the form of an axial hole matching to ensure that there is no obvious jumping of the scale during the rotation of the graticule plate. The outer frame of the graticule plate is equipped with a positioning adjustment knob (not shown in the figure) to facilitate the rotation of the graticule plate.

[0067] like Figure 8 As shown, the lighting assembly includes frosted glass 17, a reflective cup 18 and a bulb 19, and the lighting assembly and the reticle assembly are fixedly connected by a buckle that is easy to disassemble and assemble, so that the frosted glass and the bulb are easily replaced.

[0068] like Fig. 9 As shown, the detector assembly includes a right-angle prism assembly 20, a projection objective assembly 21 and a CMOS photodetector 22, wherein the projection objective assembly is arranged between the right-angle prism assembly and the CMOS photodetector, the right-angle prism assembly includes a right-angle prism adjustment mechanism and a right-angle prism, the right-angle prism adjustment mechanism can realize the pitch and rotation adjustment of the right-angle prism reflection surface, the projection objective assembly includes three groups of glued lenses 23, wherein the two groups of glued lenses at both ends are provided with radially positionable threaded adjustment frames, the CMOS photodetector is adjustably connected to the projection objective assembly front and back, so that the CMOS photodetector can also adjust the front and back positions as needed.

[0069] In this embodiment, the collimator bracket includes a front bracket and a rear bracket, and both sides of the bottom of the front bracket and the rear bracket are provided with adjustable feet (such as Fig.10 As shown), the adjustable foot can be adjusted in height by adjusting the knob 24.

[0070] like Fig.11 As shown, the electrical system of the galvanometer scanning mechanism calibrator mainly includes two parts: imaging and display, and galvanometer control.

[0071] The galvanometer control part includes a galvanometer control box for generating a galvanometer drive signal.

[0072] like Fig.12As described above, the galvanometer control box is mainly composed of a control panel, an operation panel and a touch screen. The parameters of the galvanometer drive waveform and the galvanometer are set and controlled through the touch screen. The parameter settings include the amplitude, frequency and linearity of the drive waveform. If the linearity is set to 100%, the drive signal is a triangular wave, otherwise it is a dome triangular wave with a smooth transition at the inflection point. The control setting has three virtual buttons: start, stop and zero position, which are used to control the working state of the galvanometer. The control panel is composed of a microcontroller, a DAC, a signal processing circuit, etc. It processes the information set by the user, calculates and generates a discrete data table of the galvanometer drive analog signal, and converts it into a corresponding analog signal through a digital-to-analog converter DAC according to the corresponding timing. The output of the DAC is then amplified and filtered by the signal processing circuit to generate a bipolar galvanometer drive signal. Its principle block diagram is shown as follows Fig.13 As shown. The operation panel includes three button switches for power, Y axis, and Z axis, as well as three corresponding indicator lights. The button switches "Y axis" and "Z axis" can be used to select the galvanometer motor whose drive signal needs to be connected, and the indicator lights can be used to display it. At the same time, a 3.5mm round jack is set under the two button switches "Y axis" and "Z axis", respectively, through which the position feedback signal of the corresponding motor can be measured.

[0073] The working principle of the present invention is: fix the galvanometer scanning mechanism through the galvanometer fixing seat and connect the laser and the galvanometer control box to ensure the level of the galvanometer scanning mechanism, so that the center of the reflector of the galvanometer scanning mechanism is basically aligned with the center of the graticule of the parallel light tube; after power-on, the galvanometer control box controls the scanning angle and frequency of the galvanometer scanning mechanism, displays the terminal imaging and measures the scanning angle of the galvanometer scanning mechanism, as well as the left-right symmetry and the scanning zero position, and adjusts the relevant parameters of the galvanometer scanning mechanism driving board until the relevant parameters of the galvanometer scanning mechanism meet the use requirements.

[0074] The embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A galvanometer scanning mechanism calibration instrument, comprising an optical platform, characterized in that: The optical platform is provided with: Laser: can generate parallel point light source and can adjust the intensity of the light source; Multifunctional transfer table: used to transfer and fix the galvanometer to be measured; Galvanometer fixing seat: used to realize 45° tilt fixing of single-axis galvanometer mirror and vertical cross fixing of dual-axis galvanometer; Galvanometer control box: used to generate the input signal required for the test and control the galvanometer to generate the corresponding deflection angle and yaw frequency; Collimator: used to collimate the laser beam after being deflected by the galvanometer, so that it is projected onto the graticule inside the collimator and can be normally detected and received by the detector assembly; Detector assembly: used to detect 650nm red light and 980nm and 1060nm infrared light, and then display the motion trajectory of the laser point. It has an electronic graticule to measure the scanning range and evaluate the scanning field range and the symmetry of the light spot. Display terminal: used to display the image received by the detector assembly for real-time observation; Collimator bracket: used to place the collimator and adjust the height and azimuth of the collimator to achieve aiming at the target.

2. The galvanometer scanning mechanism calibration instrument according to claim 1, characterized in that: The galvanometer control box has an electronic touch screen, which can generate a scanning signal for driving the galvanometer according to the frequency and amplitude set by the user.

3. The galvanometer scanning mechanism calibration instrument according to claim 1, characterized in that: The detector assembly includes a right-angle prism assembly, a projection objective assembly and a CMOS photodetector. The projection objective assembly is arranged between the right-angle prism assembly and the CMOS photodetector. The right-angle prism assembly includes a right-angle prism adjustment mechanism and a right-angle prism. The right-angle prism adjustment mechanism can realize the pitch and rotation adjustment of the right-angle prism reflection surface. The projection objective assembly includes three groups of glued lenses, wherein the two groups of glued lenses at both ends are provided with radially positionable threaded adjustment frames. The CMOS photodetector is adjustably connected to the projection objective assembly in a front-to-back manner.

4. The galvanometer scanning mechanism calibration instrument according to claim 1, characterized in that: The reticle adopts a frosted glass substrate and is engraved with crosshairs and light spot scanning boundary lines, which can meet a scanning range of ±4.3°.

5. The galvanometer scanning mechanism calibration instrument according to claim 3, characterized in that: The electronic scale lines of the CMOS photodetector are precisely engraved, and the minimum resolution angle is less than 30".

6. The galvanometer scanning mechanism calibration instrument according to claim 1, characterized in that: The collimator comprises an objective lens assembly, a beam splitter prism assembly, a graticule assembly and an illumination assembly. The objective lens assembly comprises an objective lens frame, a lens, a lens spacer ring and a framed attenuation plate. The beam splitter prism of the beam splitter prism assembly can achieve a radial posture of ±3° in the optical path. The graticule assembly comprises a graticule adjustment mechanism and a graticule. The graticule adjustment mechanism can achieve front and rear position and positive adjustment of the graticule. The illumination assembly comprises frosted glass, a reflective cup and a bulb. The illumination assembly and the graticule assembly are fixedly connected by a buckle for easy disassembly and assembly.

7. The galvanometer scanning mechanism calibration instrument according to claim 6, characterized in that: The reticle adjustment mechanism includes an inner adjustment ring and an outer adjustment ring. The inner adjustment ring is threadedly connected to the inner side of the outer adjustment ring. The reticle is threadedly connected to the inner side of the inner adjustment ring through an outer frame. The outer frame of the reticle is matched with an axial hole to ensure that no obvious reticle jump occurs during the rotation of the reticle.

8. The galvanometer scanning mechanism calibration instrument according to claim 1, characterized in that: The collimator bracket comprises a front bracket and a rear bracket. Both sides of the bottom of the front bracket and the rear bracket are provided with adjustable feet, and the height of the adjustable feet can be adjusted by adjusting knobs.

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