Laser scanning galvanometer performance detection device

Abstract

The present invention discloses a laser scanning galvanometer performance detection device, comprising: an optical platform, a galvanometer, a laser, a galvanometer adjustment platform, an optical focusing lens, an azimuth rotation platform, and a data collector; the galvanometer adjustment platform, the azimuth rotation platform, and the data collector are all fixedly mounted on the optical platform; the galvanometer is fixed to the galvanometer adjustment platform; the azimuth rotation platform is arranged corresponding to the galvanometer adjustment platform; the data collector comprises: a detector, a synchronous acquisition circuit box, and an industrial computer; the detector is mounted on the azimuth rotation platform; the optical focusing lens is mounted in front of the detector, and the laser is mounted on the top of the detector, and the three are mechanically connected; the detector is electrically connected to the synchronous acquisition circuit box; and the synchronous acquisition circuit box is electrically connected to the industrial computer. The present invention provides a laser scanning galvanometer performance detection device, which not only improves imaging stability, but also ensures the uniformity of the swing angle, while accurately measuring dynamic scanning parameters, further ensuring scanning and imaging quality.

Description

Technical Field

[0001] The present invention relates to the technical field of optical precision measurement, and more particularly to a laser scanning galvanometer performance detection device. Background Art

[0002] High-frequency and high-precision galvanometers are key components of linear scanning imaging systems. Parameters such as the linear characteristics of the galvanometer's swing seriously affect the scanning and imaging quality, while the swing repeatability affects the imaging stability.

[0003] With the development of laser scanning technology, laser scanning galvanometers are increasingly being used in a wide range of applications, such as laser internal engraving, laser marking, and lidar. Laser scanning galvanometers play a significant role, and the performance requirements for them are becoming increasingly stringent. Currently, commonly used methods for measuring galvanometer characteristic parameters include circular grating angle measurement, laser interferometry, internal reflection high-precision differential small swing angle measurement, and autocollimation angle measurement. The circular grating angle measurement method uses moiré fringes to measure the angle of rotation of the galvanometer. It has high measurement accuracy, fast speed and strong anti-interference ability. However, since this method requires the installation of a circular grating structure on the galvanometer as an auxiliary, it cannot achieve non-contact measurement; the laser interferometry angle measurement method uses the optical path difference between the measuring beam and the reference beam caused by the rotation angle of the galvanometer to measure the angle of rotation of the galvanometer. Its measurement accuracy is relatively high, but it requires the installation of auxiliary devices such as fisheye lenses or corner prisms on the galvanometer, which will affect the dynamic performance of the galvanometer; the principle of the reflective high-precision differential small swing angle measurement method is to place two reflectors in the transmission and reflection directions of the spectrometer, and use the change in the reflectivity of the two reflectors (which changes with the incident angle) to measure the size of the incident angle. This method can achieve non-contact measurement and high-speed measurement, but since the linear relationship between the reflectivity and the incident angle only holds near the critical angle, its measurement range is limited. In use, it is often necessary to use other angle measurement equipment for rough measurement, and the measurement efficiency is low. The autocollimation angle measurement method uses the object-image relationship characteristics of the optical system to measure the angle of the incident light. It can measure two-dimensional angles and is non-contact. However, its angle measurement range is very small and the frequency response is low, making it difficult to apply in galvanometer testing.

[0004] Therefore, how to provide a laser scanning galvanometer performance detection device that can ensure scanning and imaging quality is a problem that those skilled in the art urgently need to solve. Summary of the Invention

[0005] In view of this, the present invention provides a laser scanning galvanometer performance detection device, which not only improves the stability of imaging, but also ensures the uniformity of the swing angle, while accurately measuring the dynamic scanning parameters, further ensuring the scanning and imaging quality.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] A laser scanning galvanometer performance detection device comprises: an optical platform, a galvanometer, a laser, a galvanometer adjustment platform, an optical focusing lens, an azimuth rotation platform, and a data collector; wherein the galvanometer adjustment platform, the azimuth rotation platform, and the data collector are all fixedly mounted on the optical platform; the galvanometer is fixed on the galvanometer adjustment platform; the azimuth rotation platform is arranged corresponding to the galvanometer adjustment platform;

[0008] The data collector includes: a detector, a synchronous acquisition circuit box and an industrial computer; the detector is installed on the azimuth rotation table; the optical focusing lens is installed in front of the detector, and the laser is installed on the top of the detector. The detector, the optical focusing lens and the laser are mechanically connected; the detector is electrically connected to the synchronous acquisition circuit box; the synchronous acquisition circuit box is electrically connected to the industrial computer.

[0009] Through the above technical scheme, the technical effects of the present invention are: not only simple in structure and easy to operate, but also high in measurement efficiency, capable of detecting the motion state of the galvanometer in real time, realizing non-contact measurement, and accurately and effectively realizing the measurement of the zero position repeatability of the galvanometer, the measurement of the scanning frequency, the measurement of the time utilization rate of the linear segment, the measurement of the effective swing angle of the linear segment, and the measurement of the speed uniformity of the linear segment.

[0010] Preferably, in the above-mentioned laser scanning galvanometer performance detection device, the galvanometer is fixed on the galvanometer adjustment platform by a clamping structure.

[0011] Through the above technical solution, the technical effect of the present invention is: it is used to fix the galvanometer to ensure the stability of the galvanometer, so as to ensure the accuracy of measurement of various parameters.

[0012] Preferably, in the above-mentioned laser scanning galvanometer performance detection device, the laser further comprises: a Powell prism; and the parallel laser light emitted by the laser passes through the Powell prism to form a "one" light source.

[0013] Through the above technical solution, the technical effects of the present invention are: the laser is optimally divided into a "one" light source with uniform light density, good stability and good linearity through the Powell prism; the "one" light source has high visibility and is convenient for adjusting the angle of reflected light; it is convenient for scanning light and imaging on the detector, overcoming the problem of reflected light deviating from the detector due to the deviation of the swing axis of the galvanometer.

[0014] Preferably, in the above-mentioned laser scanning galvanometer performance detection device, the galvanometer adjustment platform includes: a dual-axis adjustment platform and a scissor-type lifting platform; one end of the scissor-type lifting platform is fixed on the optical platform, and the other end is connected to the dual-axis adjustment platform.

[0015] Through the above technical solution, the technical effect of the present invention is as follows: the scissor-type lifting platform realizes the adjustment of the azimuth of the galvanometer, and the dual-axis adjustment platform realizes the adjustment of the pitch.

[0016] Preferably, in the above-mentioned laser scanning galvanometer performance detection device, the optical focusing lens adopts an F-θ field lens.

[0017] Through the above technical solution, the technical effect of the present invention is: to ensure the linearity of the input angle and the position of the light spot on the detector.

[0018] Preferably, in the above-mentioned laser scanning galvanometer performance detection device, the detector includes: a photoelectric sensor and a front-end amplifier board; the photoelectric sensor collects data and transmits it to the synchronous acquisition circuit box through the front-end amplifier board.

[0019] Through the above technical solution, the technical effect of the present invention is: in order to ensure the analysis of various performance indicators of the galvanometer, specifically including:

[0020] 1. Calculation of light source swing angle

[0021] The maximum swing angle of the galvanometer is ±α°. According to the law of reflection, when the galvanometer swings α°, the incident laser will be reflected 2α°. According to the symmetry of the galvanometer swing, when the swing angle is -α°, the incident laser will be reflected -2α°. Therefore, the swing angle of the incident laser after reflection by the galvanometer is ±2α°, that is, 4α°.

[0022] 2. Calculation of spatial resolution

[0023] The galvanometer acceptance angle range is ±2α°, the available size of the detector's photosensitive surface is L, and the detector can achieve a spatial resolution of 1μm. Therefore, the number of parts N into which the photosensitive surface can be divided in the horizontal space is:

[0024] N=L / 1μm

[0025] The angle corresponding to each 1μm photosensitive surface is:

[0026]

[0027] 3. Angular resolution calculation

[0028] The response time of the detector of the present invention is t, and the angular resolution is

[0029]

[0030] Preferably, in the above-mentioned laser scanning galvanometer performance detection device, the synchronous acquisition circuit box includes a data acquisition card and an AD conversion module; the data acquisition card processes the signal amplified and filtered by the preamplifier board; and then obtains a digital signal through the AD conversion module and transmits it to the industrial computer.

[0031] Through the above technical solution, the technical effect of the present invention is: to achieve real-time data collection and improve test accuracy.

[0032] Preferably, in the above-mentioned laser scanning galvanometer performance detection device, the maximum swing angle of the galvanometer is ±α°, and the angle of the maximum swing angle is defined as the angle between the galvanometer and the vertical direction.

[0033] A method for detecting the performance of a laser scanning galvanometer, the specific steps are as follows:

[0034] 1. The galvanometer is powered on, and the laser passes through the Powell prism to form an "I" light source, which is then irradiated onto the galvanometer. The "I" light source is reflected, focused by the focusing lens, and then irradiated onto the photosensitive surface of the detector;

[0035] 2. Define the working zero point, which is the middle position between the maximum positive and negative swing angles;

[0036] 3. Determine the scanning frequency based on the time it takes for the working zero point to pass through two adjacent times; determine the average frequency based on the time it takes for multiple zero points to pass through; the reciprocal of the average frequency is the scanning period.

[0037] 4. The percentage of the displacement change of the light spot on the detector in adjacent unit time (for example, 5%, manually set) is used as the basis for determining the linear segment; the linear segment time utilization rate is determined based on the percentage of the linear segment experience time in the scanning period.

[0038] 5. Calculate the average value of the effective swing angle of the linear segment to obtain the effective swing angle of the linear segment;

[0039] 6. According to the working characteristics of the detector, the ratio of the distance between adjacent sampling points and the elapsed time is used to obtain the instantaneous speed. In the linear region, the difference between the maximum instantaneous speed and the theoretical speed value corresponding to that moment is multiplied by 100% to obtain the maximum speed deviation:

[0040]

[0041] This is used as a standard to measure the speed uniformity. By calculating the maximum speed deviation in the linear segment, the uniformity of the galvanometer motion speed is obtained.

[0042] The above technical solution shows that, compared with the prior art, the present invention provides a laser scanning galvanometer performance detection device that is not only simple in structure and easy to operate, but also has high measurement efficiency. It can detect the motion state of the galvanometer in real time, achieve non-contact measurement, and accurately and effectively measure the galvanometer's zero position repeatability, scanning frequency, linear segment time utilization, linear segment effective swing angle, and linear segment speed uniformity. The laser emits a "single" light source, which illuminates the galvanometer fixed to the galvanometer adjustment table. After being reflected by the galvanometer, it is focused by a focusing lens and finally illuminates a detector. The detector receives the laser's position information in real time, analyzes and calculates the trajectory information left by the "single" light source, and displays the trajectory information on an industrial computer, thereby realizing the detection of the galvanometer performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0044] Figure 1 The accompanying drawings are structural diagrams of the present invention;

[0045] Figure 2 The accompanying drawing is a schematic structural diagram of the present invention. DETAILED DESCRIPTION

[0046] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0047] The embodiment of the present invention discloses a laser scanning galvanometer performance detection device which is not only simple in structure and easy to operate, but also has high measurement efficiency, can detect the motion state of the galvanometer in real time, realize non-contact measurement, and accurately and effectively realize the measurement of the galvanometer's zero position repeatability, the measurement of the scanning frequency, the measurement of the linear segment time utilization, the measurement of the linear segment effective swing angle, and the measurement of the linear segment speed uniformity.

[0048] like Figure 1-2As shown, a laser scanning galvanometer performance detection device includes: an optical platform 1, a galvanometer 2, a laser 3, a galvanometer adjustment platform 4, an optical focusing lens 7, an azimuth rotation platform 5, and a data collector; wherein the galvanometer adjustment platform 4, the azimuth rotation platform 5, and the data collector are all fixedly mounted on the optical platform 1; the galvanometer 2 is fixed on the galvanometer adjustment platform 4; the azimuth rotation platform 5 is arranged corresponding to the galvanometer adjustment platform 4;

[0049] The data collector includes: a detector 61, a synchronous acquisition circuit box 62 and an industrial computer 63; the detector 61 is installed on the azimuth rotation table 5; an optical focusing lens 7 is installed in front of the detector 61, and a laser 3 is installed on the top of the detector 61. The detector 61, the optical focusing lens 7 and the laser 3 are mechanically connected; the detector 61 is electrically connected to the synchronous acquisition circuit box 62; the synchronous acquisition circuit box 62 is electrically connected to the industrial computer 63.

[0050] In order to further optimize the above technical solution, the galvanometer 2 is fixed on the galvanometer adjustment platform 4 through a clamping structure.

[0051] In order to further optimize the above technical solution, the laser 3 further includes: a Powell prism; the parallel laser light emitted by the laser 3 passes through the Powell prism to form a "one" light source.

[0052] In order to further optimize the above technical solution, the galvanometer adjustment platform 4 includes: a dual-axis adjustment platform and a scissor lift platform; one end of the scissor lift platform is fixed on the optical platform 1, and the other end is connected to the dual-axis adjustment platform.

[0053] In order to further optimize the above technical solution, the optical focusing lens 7 adopts an F-θ field lens.

[0054] In order to further optimize the above technical solution, the detector 61 includes: a photoelectric sensor and a front-end amplifier board; the photoelectric sensor collects data and transmits it to the synchronous collection circuit box 62 through the front-end amplifier board.

[0055] In order to further optimize the above technical solution, the synchronous acquisition circuit box 62 includes a data acquisition card and an AD conversion module; the data acquisition card processes the signal amplified and filtered by the preamplifier board; and then obtains a digital signal through the AD conversion module and transmits it to the industrial computer.

[0056] In order to further optimize the above technical solution, the maximum swing angle of the galvanometer 2 is ±α°, and the maximum swing angle is defined as the angle between the galvanometer 2 and the vertical direction.

[0057] In order to ensure the analysis of various performance indicators of the galvanometer, specifically including:

[0058] 1. Calculation of light source swing angle

[0059] The maximum swing angle of the galvanometer is ±α°. According to the law of reflection, when the galvanometer swings α°, the incident laser will be reflected 2α°. According to the symmetry of the galvanometer swing, when the swing angle is -α°, the incident laser will be reflected -2α°. Therefore, the swing angle of the incident laser after reflection by the galvanometer is ±2α°, that is, 4α°.

[0060] 2. Calculation of spatial resolution

[0061] The galvanometer acceptance angle range is ±2α°, the available size of the detector's photosensitive surface is L, and the detector can achieve a spatial resolution of 1μm. Therefore, the number of parts N into which the photosensitive surface can be divided in the horizontal space is:

[0062] N=L / 1μm

[0063] The angle corresponding to each 1μm photosensitive surface is:

[0064]

[0065] 3. Angular resolution calculation

[0066] The response time of the detector of the present invention is t, and the angular resolution is

[0067]

[0068] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Reference can be made to the common and similar parts between the various embodiments. For the devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple, and the relevant parts can be referred to the method description.

[0069] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A laser scanning galvanometer performance detection device, characterized in that: include: An optical platform (1), a galvanometer (2), a laser (3), a galvanometer adjustment platform (4), an azimuth rotation platform (5), a data collector, and an optical focusing lens (7); wherein the galvanometer adjustment platform (4), the azimuth rotation platform (5), and the data collector are all fixedly mounted on the optical platform (1); the galvanometer (2) is fixed on the galvanometer adjustment platform (4); and the azimuth rotation platform (5) is arranged correspondingly to the galvanometer adjustment platform (4); The data collector comprises: a detector (61), a synchronous acquisition circuit box (62) and an industrial control computer (63); the detector (61) is mounted on the azimuth rotation table (5); the optical focusing lens (7) is mounted in front of the detector (61), and the laser (3) is mounted on the top of the detector (61); the detector (61), the optical focusing lens (7) and the laser (3) are mechanically connected; the detector (61) is electrically connected to the synchronous acquisition circuit box (62); and the synchronous acquisition circuit box (62) is electrically connected to the industrial control computer (63); The laser scanning galvanometer performance detection device is used to perform the following steps: When the galvanometer is powered on, the laser passes through the Powell prism to form an "I" light source, which then shines on the galvanometer. The "I" light source is reflected, focused by the focusing lens, and then shines on the photosensitive surface of the detector. Define the working zero point, which is the middle position between the maximum positive and negative swing angles. The maximum swing angle of the galvanometer is ±α°. According to the law of reflection, when the galvanometer swings α°, the incident laser will be reflected by 2α°. Based on the symmetry of the galvanometer swing, when the swing angle is -α°, the incident laser will be reflected by -2α°. Therefore, the swing angle of the incident laser after reflection from the galvanometer is ±2α°, that is, 4α°. The scanning frequency is determined by the time it takes for the two adjacent working zero points to pass through; the average frequency is determined by the time it takes for multiple zero points to pass through; the reciprocal of the average frequency is the scanning period; The percentage of the displacement change of the light spot on the detector in adjacent unit time is used as the basis for determining the linear segment; the linear segment time utilization rate is determined based on the percentage of the linear segment experience time to the scanning period; Calculate the average value of the effective swing angle of the linear segment to obtain the effective swing angle of the linear segment; According to the working characteristics of the detector, the ratio of the distance between adjacent sampling points and the elapsed time is used to obtain the instantaneous velocity. In the linear region, the difference between the maximum instantaneous velocity and the theoretical velocity value corresponding to the elapsed time is multiplied by 100% to obtain the maximum velocity deviation: ； This is used as a standard to measure the speed uniformity. By calculating the maximum speed deviation in the linear segment, the uniformity of the galvanometer motion speed is obtained.

2. The laser scanning galvanometer performance detection device according to claim 1, characterized in that: The galvanometer (2) is fixed on the galvanometer adjustment platform (4) via a clamping structure.

3. The laser scanning galvanometer performance detection device according to claim 1, characterized in that: The laser (3) further comprises a Powell prism; the parallel laser light emitted by the laser (3) passes through the Powell prism to form a "one" light source.

4. The laser scanning galvanometer performance detection device according to claim 1, characterized in that: The galvanometer adjustment platform (4) comprises: a dual-axis adjustment platform and a scissor-type lifting platform; one end of the scissor-type lifting platform is fixed on the optical platform (1), and the other end is connected to the dual-axis adjustment platform.

5. The laser scanning galvanometer performance detection device according to claim 4, characterized in that: The optical focusing lens adopts an F-θ field lens.

6. The laser scanning galvanometer performance detection device according to claim 4, characterized in that: The detector (61) comprises: a photoelectric sensor and a front-end amplifier board; the photoelectric sensor collects data and transmits the data to the synchronous collection circuit box (62) through the front-end amplifier board.

7. The laser scanning galvanometer performance detection device according to claim 6, characterized in that: The synchronous acquisition circuit box (62) comprises a data acquisition card and an AD conversion module; the data acquisition card processes the signal amplified and filtered by the front-end amplifier; the digital signal is then obtained through the AD conversion module and transmitted to the industrial control computer.

8. A laser scanning galvanometer performance detection device according to any one of claims 1 to 7, characterized in that: The maximum swing angle of the galvanometer (2) is ±α°, and the angle of the maximum swing angle is defined as the angle between the galvanometer (2) and the vertical direction.

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