CN115213565A - Laser marking device and method - Google Patents

Abstract

The invention relates to a laser marking device and a method, wherein the laser marking device comprises a laser, an acousto-optic modulator, a first reflector, a first light path collimation assembly, a beam expander and a scanning galvanometer; the laser instrument produces the laser beam who beats the standard and uses, behind laser beam got into acousto-optic modulator, acousto-optic modulator can diffract at least part of laser beam to the direction towards first speculum, and first speculum is used for reflecting laser beam to first light path collimation subassembly, and laser beam adjusts the collimation through first light path collimation subassembly and penetrates into the scanning mirror that shakes after the beam expander expands, and the scanning mirror that shakes is used for making laser beam throw after taking place to deflect and on beating the mark plane and scan along preset orbit and beat the mark. The laser can output stable laser power in the marking process, and the problem that the processing starting head is too heavy when the rapid jump of the laser power is realized by controlling an acousto-optic switch in an internal cavity of the laser in the prior art because the laser continuously emits light is solved.

Description

Laser marking device and method

Technical Field

The invention belongs to the technical field of laser application, and particularly relates to a laser marking device and method.

Background

In the card bitmap laser marking processes such as passports and the like, the laser bitmap marking technology can play a high-grade anti-counterfeiting role, different marking contents are quickly switched to mark patterns, the processing effect that the recognition degree is high and the abrasion is not easy to occur can be processed on a thermosensitive product, and the printing effect of a gray level printer on the market is difficult to meet the requirement.

At present, the following laser bitmap marking methods exist in the market:

in the first mode, a marking control system is adopted to output a PWM signal duty ratio value with adjustable duty ratio and establish a mapping relation with a bitmap gray value, so that acousto-optic on-off response of a cavity inside the laser is controlled, and rapid jump of laser power is realized. The mode has the advantages that the adjustable duty ratio allowance of the PWM signal is small, the linear corresponding relation between the radio frequency power of the acousto-optic switch driver and the duty ratio of the PWM signal is poor, the requirement on the working characteristics of a laser cavity is particularly high, the consistency difficulty of batch production is very high, in addition, the problem that the initial point of a processing pen is too heavy (namely the power of a laser beam at the initial point is too large) exists when light locking energy storage and release exist in the cavity, and the debugging difficulty is large.

And in the second mode, the marking control system is adopted to output 0-5V analog voltage signals and establish a mapping relation with bitmap gray values to control the radio frequency output of the acousto-optic switch, so that the laser power output by the internal cavity of the laser is modulated to rapidly jump. The analog voltage signal output by the method. The requirement on the working characteristics of the laser cavity is extremely high, the consistency difficulty of batch production is very high, the problem that the initial point is too heavy when the pen is started in processing also exists, and the debugging difficulty is high.

The marking in the third mode is to control the current value of a laser diode LD in the laser and establish a mapping relation with the bitmap gray value sum, and the laser power of 808nm output by the LD and the current input value of the LD in a stable region present a nonlinear increasing relation, so that the power output by the laser is controlled to change rapidly. The method requires a constant power supply with microsecond-level quick response to drive the LD, requires the LD working current range to be fast enough to drive the LD output power to jump quickly, and has lag in changing the LD power to the infrared laser power response change frequently.

The three modes obtain the laser power change with quick response by directly changing the output power of the 1064nm light source of the laser to carry out bitmap processing, have the defects of high requirement on the performance of a laser cavity, unstable marking effect, high debugging difficulty and high reject ratio during batch production, and are difficult to meet the market requirement.

Disclosure of Invention

The invention aims to solve the defects in the prior art at least to a certain extent and provides a laser marking device and method.

In order to achieve the above purpose, the present invention provides a laser marking device, which comprises a laser, an acousto-optic modulator, a first reflector, a first light path collimation assembly, a beam expander and a scanning galvanometer;

the laser instrument produces the laser beam who uses when marking, laser beam gets into behind the acoustic optical modulator, the acoustic optical modulator can be with at least part laser beam diffracts orientation the direction of first speculum, first speculum is used for with laser beam reflects extremely first light path collimation subassembly, laser beam warp first light path collimation subassembly adjustment collimation and process kick into after the beam expanding mirror expands the scanning shakes in the mirror, the scanning shakes the mirror and is used for making laser beam takes place to deflect and then throws on marking the plane, and mark along the scanning of predetermineeing the orbit on the marking plane and beat the mark.

Preferably, the laser marking device further comprises a marking control system and a first radio frequency driver, the marking control system is connected with the acousto-optic modulator electrically through the first radio frequency driver, the marking control system can output a first radio frequency modulation signal to control the working state of the acousto-optic modulator, and the radio frequency power of the first radio frequency modulation signal corresponds to the bitmap grey value of the graph to be marked.

Preferably, the laser includes laser source and the resonant cavity that has acousto-optic switch, laser marking device is still including laser controller, laser controller includes laser power supply and second radio frequency driver, mark control system passes through laser power supply with the laser source electricity is connected, mark control system pass through the second radio frequency driver with acousto-optic switch electricity is connected.

Preferably, the scanning galvanometer comprises an X-axis reflecting galvanometer and a Y-axis reflecting galvanometer, and the marking control system is electrically connected with driving devices of the X-axis reflecting galvanometer and the Y-axis reflecting galvanometer respectively and used for adjusting the positions of the X-axis reflecting galvanometer and the Y-axis reflecting galvanometer according to the preset track.

Preferably, the laser marking device further comprises a laser absorber, and when the acousto-optic modulator is in a non-working period, the laser beam passes through the acousto-optic modulator and then irradiates on the laser absorber.

Preferably, the exit port of the laser is further provided with a polarization adjuster, and the polarization adjuster is used for adjusting the polarization state of the laser beam emitted by the laser.

Preferably, the first optical path collimating assembly is disposed between the first reflecting mirror and the beam expanding mirror, and is configured to reflect the laser beam reflected by the first reflecting mirror to the beam expanding mirror, the first optical path collimating assembly includes a second reflecting mirror and a third reflecting mirror, which are opposite to each other, where the second reflecting mirror is configured to receive the laser beam emitted from the first reflecting mirror, and the third reflecting mirror is configured to adjust and collimate the laser beam and reflect the laser beam to the beam expanding mirror.

Preferably, the laser marking device further includes a second light path collimation assembly disposed between the laser and the acousto-optic modulator, the second light path collimation assembly is configured to reflect the laser beam emitted from the laser to the acousto-optic modulator, the second light path collimation assembly includes a fourth mirror and a fifth mirror that are opposite to each other, the fourth mirror is configured to receive the laser beam emitted from the laser, and the fifth mirror is configured to adjust, collimate and emit the laser beam to the acousto-optic modulator.

Preferably, the exit port of the scanning galvanometer is further provided with a focusing mirror, and the focusing mirror is used for focusing and projecting the laser beam deflected and emitted by the scanning galvanometer onto a marking plane to form a scanning point.

The invention also provides a laser marking method, which adopts the laser marking device and comprises the following steps:

turning on the laser to generate a laser beam, and enabling the laser beam to be emitted into the acousto-optic modulator;

inputting a first radio frequency modulation signal to the acousto-optic modulator so as to diffract the incident laser beam to the direction towards the first reflector, wherein the radio frequency power of the first radio frequency modulation signal corresponds to the bitmap gray value of the graph to be marked;

utilize first speculum will laser beam reflects extremely first light path collimation subassembly, first light path collimation subassembly will laser beam adjusts the collimation and passes through after the beam expander expands the beam the reflection of beam into in the mirror that shakes is shaken in the scanning, through the mirror that shakes deflects in the scanning laser beam makes its projection beat on marking the plane and scan along preset orbit and mark.

According to the laser marking device and method, the switching of the laser beam emitted by the laser in the extending direction and the diffraction direction is realized through the acousto-optic modulator, and the output power of the laser beam in the diffraction direction is adjusted, so that the laser can output stable laser power to realize continuous light emitting, and the problem that the processing of the initial point of the laser is too heavy when the rapid jump of the laser power is realized by controlling an acousto-optic switch in an inner cavity of the laser in the prior art is solved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the description of the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without inventive labor.

FIG. 1 is a schematic block diagram of an embodiment of a laser marking apparatus of the present invention;

FIG. 2 is a schematic view of a scanning track of the laser marking device during marking;

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary and intended to be illustrative of the present invention and should not be construed as limiting the present invention, and all other embodiments that can be obtained by one skilled in the art based on the embodiments of the present invention without inventive efforts shall fall within the scope of protection of the present invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

Referring to fig. 1, an embodiment of the present invention provides a laser marking apparatus, including a laser 10, an acoustic optical modulator 30 (AOM), a first reflector 40, a first optical path collimating assembly 50, a beam expander 60, and a scanning galvanometer 70;

the laser 10 generates a laser beam used for marking, after the laser beam enters the acousto-optic modulator 30, the acousto-optic modulator 30 is used for diffracting at least part of the laser beam to a direction facing the first reflecting mirror 40, the first reflecting mirror 40 is used for reflecting the laser beam to the first light path collimating component 50, the laser beam is adjusted and collimated by the first light path collimating component 50 and is emitted into the scanning galvanometer 70 after being expanded by the beam expander 60, and the scanning galvanometer 70 is used for projecting the laser beam on a marking plane after the laser beam is sounded and deflected, and scanning and marking are carried out along a preset track on the marking plane.

It should be noted that the acousto-optic modulator 30 is used as an acousto-optic switch driven by a high-frequency rf signal, and when the acousto-optic modulator 30 has no rf power (i.e. the acousto-optic modulator is in a non-operating state), the laser beam generated by the laser 10 can be emitted along the extending direction when entering the acousto-optic modulator 30, and cannot be received by the first reflector 40; when the acousto-optic modulator 30 has radio frequency power (i.e. the acousto-optic modulator is in an operating state), at least a part of the incident laser beam is diffracted to the direction facing the first reflecting mirror 40, and is emitted from the first reflecting mirror 40 to the first optical path collimating assembly 50, so as to enter the optical path of the normal marking process.

The laser marking device of this embodiment realizes switching of the laser beam that laser instrument 10 jetted out and adjusts the output power of laser beam in the diffraction direction between extending direction and diffraction direction through acousto-optic modulator 30 to make laser instrument 10 exports stable laser power and realize continuous light-emitting, have avoided having the problem that the processing plays a first point overweight when jumping fast because of adopting the acousto-optic switch in the inside cavity of control laser instrument among the prior art.

Specifically, the laser marking device further includes a marking control system 90 and a first radio frequency driver 31, the marking control system 90 is electrically connected to the acousto-optic modulator 30 through the first radio frequency driver 31, the marking control system 90 outputs a first radio frequency modulation signal to the first radio frequency driver 31 to control the working state of the acousto-optic modulator 30, and the radio frequency power of the first radio frequency modulation signal corresponds to the bitmap gray value of the pattern to be marked. Therefore, the acousto-optic modulator 30 is used for rapidly changing the switching of the laser beam between the extending direction and the diffraction direction and the output power of the laser beam in the diffraction direction according to the first radio frequency modulation signal, so that the laser beam can accurately process the graph to be marked on the marking plane according to the bitmap gray value, and the laser power output by the laser 10 does not need to be changed in the whole laser marking process.

The laser 10 includes a laser light source 11 and a resonant cavity 12 having an acousto-optic switch 121, the laser marking device further includes a laser controller 80, the laser controller 80 includes a laser power source 81 and a second radio frequency driver 82, the marking control system 90 is electrically connected with the laser light source 11 through the laser power source 81, and the marking control system 90 is electrically connected with the acousto-optic switch 121 through the second radio frequency driver 82. In this embodiment, the resonant cavity 12 is a 2-frequency doubling crystal resonator, and the laser light source 11 outputs a laser beam with a wavelength of 808nm through the resonant cavity 12 to finally form a laser beam with a wavelength of 1064nm emitted from the laser 10.

According to the laser marking device of the embodiment, according to the processing requirements of different products, the laser 10 outputs a laser beam with a 1064nm waveband and unchanged power, the marking control system 90 outputs a second radio frequency modulation signal (PWM modulation signal) corresponding to the processing frequency and the release parameter in advance to control the acousto-optic on-beam continuous and stable operation inside the laser 10 during processing, and outputs a first radio frequency modulation signal with the radio frequency power corresponding to the bitmap gray value of the pattern to be marked while the marking control system 90 outputs the second radio frequency modulation signal, and the acousto-optic modulator 30 distributes the output power of the laser beam emitted by the laser 10 in two traveling directions to rapidly change the processing power of the laser beam finally output to the marking plane, so that the laser 10 can be ensured to output stable laser power in the whole marking processing process.

The scanning galvanometer 70 comprises an X-axis reflecting galvanometer and a Y-axis reflecting galvanometer, and the marking control system 90 is electrically connected with the driving devices of the X-axis reflecting galvanometer and the Y-axis reflecting galvanometer respectively and used for adjusting the positions of the X-axis reflecting galvanometer and the Y-axis reflecting galvanometer according to a preset track. The marking control system 90 plans the skip and the scanning track of the scanning galvanometer 70 according to the graph to be represented, and generates a corresponding control instruction to control the scanning galvanometer 70, so as to realize the equidistant line-by-line scanning marking processing of the graph to be marked. In addition, as shown in fig. 2, when the marking control system 90 plans the scanning trajectory, by adding the extended auxiliary line before starting the light-emitting marking process every time, the scanning galvanometer 70 jumps to the starting point of the auxiliary line at the front end of the light-emitting line in the idle mode every time and starts accelerating to the uniform speed when marking, and then starts the laser after reaching the calculated light point, so that the characteristic of motion lag of the scanning galvanometer 70 can be solved, and the problem of poor marking effect caused by uneven motion speed when the scanning galvanometer 70 starts and stops moving is avoided.

In one embodiment, the laser marking device further comprises a laser absorber 100, and when the acousto-optic modulator 30 is in the non-operating period, the laser beam passes through the acousto-optic modulator 30 and then irradiates the laser absorber 100. The laser absorber 100 is made of a metal material with good light absorption property and good heat dissipation performance, and is used for absorbing laser beam energy emitted by the laser 10 in a low-power marking processing state, and cooling systems such as air cooling or circulating water cooling can be added according to actual needs, so that the device can be prevented from being damaged due to long-term high-power operation.

Further, the rf output power and the diffracted laser power curve are almost linearly proportional in a wide curve range of the operation of the aom 30, and the polarization state of the incident laser beam may affect the diffraction efficiency of the aom 30, so in the embodiment of the present invention, a polarization adjuster 13 is further disposed at the exit of the laser 10, and the polarization adjuster 13 is used for adjusting the polarization state of the laser beam emitted from the laser 10. Because the polarization state of the output laser beam is not completely consistent due to the difference of the installation of the internal devices of the laser 10, the emitted laser beam is transmitted to the polarization adjuster 13, the polarization adjuster 13 comprises a glass slide with an infrared band and a driving device capable of driving the glass slide to rotate, the polarization state of the output laser beam of the polarization adjuster 13 is changed by rotating the angle of the glass slide through the driving device, so that the laser beam with the same polarization state is always obtained and output to the acousto-optic modulator 30, and the diffraction efficiency of the acousto-optic modulator 30 can be adjusted to reach the maximum value through the angle of the glass slide of the polarization adjuster 13. The driving device may adopt a motor, a rotary cylinder, a rotary electromagnet, or other devices capable of controlling rotation, and of course, in other embodiments, the polarization state of the laser beam may be adjusted by directly replacing different glass slides, which is not limited herein.

Specifically, the first optical path collimating assembly 50 is disposed between the first reflecting mirror 40 and the beam expanding mirror 60, and is configured to reflect the laser beam reflected by the first reflecting mirror 40 to the beam expanding mirror 60, the first optical path collimating assembly 50 includes a second reflecting mirror 51 and a third reflecting mirror 52, which are opposite to each other, the second reflecting mirror 51 is configured to receive the laser beam emitted from the first reflecting mirror 40, and the third reflecting mirror 52 is configured to collimate and reflect the laser beam to the beam expanding mirror 60. In this embodiment, the reflection plane of the first reflector 40 may be disposed on a horizontal plane, when the acousto-optic modulator 30 diffracts the laser beam to irradiate the first reflector 40, the incident light and the reflected light of the laser beam on the first reflector 40 are inclined with respect to the horizontal plane, and the collimation of the laser beam reflected by the first reflector 40 after passing through the first optical path collimation assembly 50 can be ensured by adjusting the second reflector 51 and the third reflector 52, so that the laser beam is collimated and incident into the beam expander 60 along the horizontal direction.

In addition, the beam expander 60 may be a fixed-magnification beam expander, an adjustable beam expander, or other conventional beam expanders, and is configured to adjust the spot size and the divergence angle of the laser beam incident on the scanning galvanometer 70; the exit port of the scanning galvanometer 70 is further provided with a focusing mirror 71, the focusing mirror 71 is an F-Theta lens, and after the laser beam expanded and adjusted by the beam expander 60 enters the scanning galvanometer 70, the laser beam is reflected twice by the X-axis reflection galvanometer and the Y-axis reflection galvanometer and is focused on the marking plane by the focusing mirror 71 to form a focusing spot with uniform size.

Further, the laser marking device further includes a second optical path collimating assembly 20 disposed between the laser 10 and the acousto-optic modulator 30, the second optical path collimating assembly 20 is configured to reflect the laser beam emitted from the laser 10 to the acousto-optic modulator 30, the second optical path collimating assembly 20 includes a fourth mirror 21 and a fifth mirror 22, which are opposite to each other, the fourth mirror 21 is configured to receive the laser beam emitted from the laser 10, and the fifth mirror 22 is configured to collimate and emit the laser beam to the acousto-optic modulator 30. Thus, even if the laser beam emitted by the laser 10 is inclined with respect to the horizontal plane, the collimation of the laser beam emitted by the laser 10 after passing through the second optical path collimating assembly 20 can be ensured by adjusting the fourth mirror 21 and the fifth mirror 22, so that the laser beam is collimated and emitted into the acousto-optic modulator 30 along the horizontal direction.

The invention also provides a laser marking method, which adopts the laser marking device and comprises the following steps:

s10, turning on the laser 10 to generate a laser beam, and enabling the laser beam to be emitted into the acousto-optic modulator 30;

s20, inputting a first radio frequency modulation signal to the acousto-optic modulator 30 to diffract the incident laser beam to the direction facing the first reflector 40, wherein the radio frequency power of the first radio frequency modulation signal corresponds to the bitmap gray value of the pattern to be marked;

s30, reflecting the laser beam to the first light path collimation assembly 50 by using the first reflecting mirror 40, adjusting and collimating the laser beam by the first light path collimation assembly 50, expanding the beam by the beam expanding lens 60, and then injecting the beam into the scanning galvanometer 70, deflecting the laser beam by the scanning galvanometer 70 to enable the laser beam to be projected on a marking plane and to scan and mark along a preset track.

In this embodiment, the laser 10 outputs a laser beam with a 1064nm waveband and unchanged power, the marking control system 90 outputs a second radio frequency modulation signal (PWM modulation signal) corresponding to the processing frequency and the release parameter in advance to control the acousto-optic on-beam continuous and stable operation inside the laser 10 during processing, outputs a first radio frequency modulation signal with a radio frequency power corresponding to the bitmap gray value of the pattern to be marked while the marking control system 90 outputs the second radio frequency modulation signal, and distributes the output power of the laser beam emitted by the laser 10 in two traveling directions by using the acousto-optic modulator 30 to rapidly change the processing power of the laser beam finally output to the marking plane; so can guarantee that laser instrument 10 outputs stable laser power in the whole mark course of working of beating, because laser instrument 10 goes out light in succession, do not have lock light energy storage problem, consequently do not have the overweight problem of processing initial point of getting up.

In addition, when the marking control system 90 plans the scanning track, the extended auxiliary line is added before the light emitting and marking processing is started each time, the scanning galvanometer 70 jumps to the starting point of the auxiliary line at the front end of the light emitting line in an idle mode each time and starts to accelerate to the uniform speed when marking, and the laser is started after the light spot is calculated, so that the characteristic of motion lag of the scanning galvanometer 70 can be solved, and the problem of poor marking effect caused by uneven motion speed when the scanning galvanometer 70 starts and stops moving is avoided.

In the foregoing embodiments, the descriptions of the respective embodiments have respective emphasis, and for parts that are not described in detail in a certain embodiment, reference may be made to the related descriptions of other embodiments.

In view of the above description of the technical solutions provided by the present invention, those skilled in the art will recognize that there may be variations in the technical solutions and the application ranges according to the concepts of the embodiments of the present invention, and in summary, the content of the present specification should not be construed as limiting the present invention.

Claims (10)

1. A laser marking device is characterized by comprising a laser, an acoustic optical modulator, a first reflector, a first light path collimation assembly, a beam expander and a scanning galvanometer;

the utility model discloses a laser marking device, including laser instrument, laser beam, acousto-optic modulator, first speculum, scanning galvanometer, laser beam and scanning mark, the laser instrument produces the laser beam of using when marking, laser beam gets into behind the acousto-optic modulator, the acousto-optic modulator can be at least part laser beam diffracts to the orientation the direction of first speculum, first speculum be used for with laser beam reflects extremely first light path collimation subassembly, laser beam warp first light path collimation subassembly adjustment collimation and process kick after the beam expander expands the beam in the scanning galvanometer, the scanning galvanometer is used for making laser beam takes place to throw after deflecting on marking the plane, and mark along preset orbit on the marking plane and scan the mark.

2. The laser marking device according to claim 1, further comprising a marking control system and a first radio frequency driver, wherein the marking control system is electrically connected with the acousto-optic modulator through the first radio frequency driver, the marking control system is capable of outputting a first radio frequency modulation signal to the first radio frequency driver to control the operating state of the acousto-optic modulator, and the radio frequency power of the first radio frequency modulation signal corresponds to the bitmap grey value of the pattern to be marked.

3. The laser marking device according to claim 2, wherein the laser includes a laser light source and a resonant cavity having an acousto-optic switch, the laser marking device further includes a laser controller, the laser controller includes a laser power source and a second radio frequency driver, the marking control system is electrically connected to the laser light source through the laser power source, and the marking control system is electrically connected to the acousto-optic switch through the second radio frequency driver.

4. The laser marking device as claimed in claim 1, wherein the scanning galvanometer includes an X-axis reflecting galvanometer and a Y-axis reflecting galvanometer, and the marking control system is electrically connected to the driving devices of the X-axis reflecting galvanometer and the Y-axis reflecting galvanometer, respectively, for adjusting the positions of the X-axis reflecting galvanometer and the Y-axis reflecting galvanometer according to the preset track.

5. The laser marking device according to claim 1, further comprising a laser absorber on which the laser beam passes through the acousto-optic modulator when the acousto-optic modulator is in a non-operational period.

6. The laser marking apparatus according to claim 1, wherein the exit port of the laser is further provided with a polarization adjuster, and the polarization adjuster is configured to adjust a polarization state of the laser beam emitted from the laser.

7. The laser marking device as claimed in claim 1, wherein the first optical path collimating assembly is disposed between the first reflector and the beam expander for reflecting the laser beam reflected from the first reflector to the beam expander, the first optical path collimating assembly includes a second reflector and a third reflector, the second reflector is used for receiving the laser beam emitted from the first reflector, and the third reflector is used for adjusting, collimating and reflecting the laser beam to the beam expander.

8. The laser marking device according to claim 1, further comprising a second optical path collimating assembly disposed between the laser and the acousto-optic modulator, the second optical path collimating assembly being configured to reflect the laser beam emitted from the laser to the acousto-optic modulator, the second optical path collimating assembly including a fourth mirror and a fifth mirror that are opposite to each other, the fourth mirror being configured to receive the laser beam emitted from the laser, and the fifth mirror being configured to collimate the laser beam and emit the laser beam to the acousto-optic modulator.

9. The laser marking device according to claim 1, wherein the exit port of the scanning galvanometer is further provided with a focusing mirror, and the focusing mirror is configured to focus and project the laser beam deflected and emitted by the scanning galvanometer onto a marking plane to form a scanning spot.

10. A laser marking method, characterized in that a laser marking device according to any one of claims 1-9 is used, comprising the steps of:

turning on the laser to generate a laser beam, and enabling the laser beam to be emitted into the acousto-optic modulator;

inputting a first radio frequency modulation signal to the acousto-optic modulator so as to diffract the incident laser beam to the direction facing the first reflector, wherein the radio frequency power of the first radio frequency modulation signal corresponds to the bitmap gray value of the pattern to be marked;

utilize first speculum will laser beam reflects extremely first light path collimation subassembly, first light path collimation subassembly will laser beam adjusts the collimation and passes through after the beam expander expands the beam the reflection of beam into in the mirror that shakes is shaken in the scanning, through the mirror that shakes deflects in the scanning laser beam makes its projection beat on marking the plane and scan along preset orbit and mark.

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