Cleaning device and cleaning method for metal film layer on surface of large special-shaped transparent material

Abstract

The invention relates to the technical field of laser cleaning, and particularly discloses a cleaning device and a cleaning method for a metal film layer on the surface of a large special-shaped transparent material. The device comprises a three-dimensional five-axis system, a laser system, a cleaning system, a control system and a real-time feedback system, the three-dimensional five-axis system comprises an X-axis assembly, a Y-axis assembly, a Z-axis assembly and a rack, and translation, inclination and rotation of a laser cleaning head in a three-dimensional space are achieved; the laser system is composed of a laser controller and a pulse fiber laser and outputs pulse laser beams. The cleaning system is composed of a laser cleaning head. The control system is composed of a computer and is used for receiving and analyzing data and executing preset logic; the real-time feedback system is composed of a capacitance sensor, an amplifier and a digital-to-analog converter, and is used for detecting the dielectric constant change of the ITO film layer and generating a feedback signal. By means of the pulse optical fiber three-dimensional five-axis cleaning device, comprehensive machining and cleaning of large special-shaped transparent materials are achieved, the cleaning efficiency is effectively improved, and the stability and reliability of the surface removing process are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of laser cleaning, and particularly relates to a cleaning device and a cleaning method for a metal film layer on the surface of a large-sized special-shaped transparent material. Background Art

[0002] In view of the current situation of laser cleaning and the urgent current cleaning requirements, during the preparation process of a multi-layer metal film system on the surface of a large-sized special-shaped transparent material, the scrap rate reaches 10% - 20%. It is necessary to remove the abnormal surface film system and then prepare it again. Since the thickness of the film system is in the micron range and the surface quality requirements of the transparent part after removing the film system are relatively high, at present, it can only be removed by manual polishing. This process takes about 15 days, and it is difficult to ensure the quality stability and efficiency of the transparent part by this operation method.

[0003] At present, the application of laser cleaning on large-sized special-shaped transparent materials still belongs to the small-scale laboratory research stage, and there is an urgent need to develop a process equipment suitable for removing the coatings on the surface of large-sized special-shaped transparent materials.

[0004] The research on laser removal technology and the development of equipment in China started late, and basically followed the development of foreign countries. Although some achievements have been made in a relatively short period of time, there are obvious gaps compared with foreign countries. There are not many mature laser removal devices in China, and most of them are still in the laboratory research stage, and their removal efficiency and stability need to be further improved. Considering the practicality of laser removal in the industrial field, the research and development trend of domestic related equipment tend to be portable or handheld, lacking the research on complete sets of processes and equipment for efficient and precise removal of large-sized special-shaped transparent materials.

[0005] With the country's emphasis on high-end manufacturing equipment, the research and development of laser high-efficiency and precision removal technology suitable for large-sized special-shaped transparent parts is of great significance for enhancing China's industrial strength and the level of national defense high-end manufacturing. In the military industry, especially in the research and development of high-efficiency and precision removal technology equipment for large-sized special-shaped transparent materials, there are shortcomings. The main reason is that the research and development technology of high-quality laser light sources is mainly monopolized by foreign countries, and at present, there is a lack of systematic research on laser high-efficiency and precision removal processes and equipment for transparent materials in China. Therefore, the research on special equipment for laser high-efficiency and precision removal of large-sized special-shaped transparent materials is of great significance for promoting the development of the military technology industry. Summary of the Invention

[0006] In order to make up for the deficiencies of the prior art, the present invention provides a cleaning device and a cleaning method for a metal film layer on the surface of a large-sized special-shaped transparent material, which have a stable and reliable cleaning process and a high cleaning efficiency.

[0007] The present invention is realized by the following technical solutions: A cleaning device for the metal film layer on the surface of a large-sized special-shaped transparent material, comprising a frame, on which a three-dimensional five-axis system and a laser cleaning head are installed. The three-dimensional five-axis system and the laser cleaning head are respectively connected to a computer. It is characterized in that: the three-dimensional five-axis system includes an X-axis component, a Y-axis component and a Z-axis component. The Y-axis component includes two Y-axis guide rails arranged in parallel on the frame, and a Y-axis servo motor is installed at the end of the Y-axis guide rails; the X-axis component includes an X-axis guide rail with both ends respectively erected on the two Y-axis guide rails, and an X-axis servo motor is installed on one end of the X-axis guide rail; the Z-axis component includes a Z-axis seat connected to the X-axis guide rail, a Z-axis guide rail is arranged on the Z-axis seat, a Z-axis servo motor is installed on the upper part of the Z-axis seat and the output shaft of the Z-axis servo motor is connected to the Z-axis guide rail, and a laser cleaning head is installed on the Z-axis guide rail.

[0008] The present invention includes a three-dimensional five-axis system, a laser system, a cleaning system, a control system and a real-time feedback system. The three-dimensional five-axis system includes X, Y, Z-axis components and a frame, realizing the translation, tilting and rotation movements of the laser cleaning head in three-dimensional space; the laser system consists of a laser controller and a pulsed fiber laser, outputting a pulsed laser beam; the cleaning system consists of a laser cleaning head for performing cleaning operations; the control system consists of a computer for receiving data and parsing, and executing preset logic; the real-time feedback system consists of a capacitance sensor, an amplifier and an analog-to-digital converter for detecting the change in the dielectric constant of the ITO film layer and generating a feedback signal.

[0009] A more optimal technical solution of the present invention is as follows: The X-axis guide rail, Y-axis guide rail and Z-axis guide rail are all of ball screw structure. The screw shaft end of the ball screw structure is connected to the power output shaft of the servo motor through a coupling. Both ends of the X-axis guide rail are installed on the Y-axis guide rail through sliders and the fixed part of the ball structure. The Z-axis seat is fixedly installed on the X-axis guide rail through a slider and the ball structure.

[0010] An installation bracket is fixed on the Z-axis guide rail, and the laser cleaning head is installed on the installation bracket through a flange.

[0011] The laser cleaning head is provided with an optical fiber interface and is connected to the pulsed fiber laser through an optical fiber by this optical fiber interface. The pulsed fiber laser is connected to the laser controller through a communication line.

[0012] The laser controller is connected to the computer through a communication line. A capacitance sensor coaxial with the laser cleaning head is installed on the fixture of the laser cleaning head. The capacitance sensor is connected to the amplifier through a communication line, and the amplifier is connected to the computer through an analog-to-digital converter.

[0013] The frame is fixed on the equipment base.

[0014] A cleaning method for the metal film layer on the surface of a large-sized special-shaped transparent material based on the above device includes the following steps: (1)Set the laser parameters and the laser beam scanning path in the human-machine interface of the computer, so that the laser beam irradiates the metal film layer vertically; (2)Turn on the pulsed fiber laser. The laser beam irradiates the first cleaning site on the surface of the transparent part, and at the same time, the capacitance sensor starts to detect. When the ITO film exists, a strong coupling is generated due to the high conductivity between the electrodes, and the capacitance value is relatively high, detected as C_initial. As the film layer is removed, the dielectric constant of PMMA drops suddenly, and the capacitance value gradually decreases to the capacitance threshold C_threshold. The real-time capacitance value C_real of the capacitance sensor is transmitted to the computer through an amplifier and an analog-to-digital converter; (3)The computer calculates the current capacitance difference ΔC = |C_initial - C_real| and compares it with the preset threshold ΔC_threshold: If ΔC < ΔC_threshold, it is determined that the ITO film has not been completely removed, and the pulsed fiber laser continues to work; If ΔC ≥ ΔC_threshold, it is determined that the ITO film has been removed to the PMMA layer, and the computer immediately turns off the pulsed fiber laser through the laser controller; (4)After the laser stops, the computer sends an instruction to the three-dimensional five-axis system to drive the laser cleaning head to accurately move to the next cleaning site, and repeats the "detection - cleaning - movement" cycle described in steps (2) - (3) above until the entire surface of the transparent part is covered or the preset maximum cleaning times are reached.

[0015] Based on the principle that the metal film has high conductivity, PMMA is an insulator, and the dielectric constant drops suddenly after the film layer is removed, the present invention triggers the adjustment or termination of laser energy by measuring the change of the local dielectric constant in real time with a non-contact capacitive electrode plate. For multi-layer different metal layers, there may be differences in dielectric constants, and the electrical differences of multi-layer metals may be insufficient, resulting in limited resolution of the stratification signal. However, when judging the "complete presence" or "complete removal" of a single-layer ITO heterogeneous film, there is no need to distinguish the transition layer or the oxide layer, which greatly reduces the requirement for the resolution of the sensor. When the ITO film exists, the equivalent dielectric constant detected by the capacitance sensor is dominated by ITO (dielectric constant ≈ 9 - 10); after the ITO is removed, the dielectric constant of the substrate (dielectric constant ≈ 3 - 4) drops suddenly; and the difference in dielectric constants is very significant (about 3 - 10 times), so it is easy to judge whether the film layer has been removed, saving a large amount of cost and effectively and quickly completing the cleaning.

[0016] Further preferably, in step (1), the laser parameters include laser energy density, wavelength, pulse width, pulse repetition frequency, spot diameter d, laser power, scanning speed, capacitance threshold C_threshold (the dielectric constant critical value corresponding to the complete removal of the ITO film).

[0017] Further preferably, in step (2), the output wavelength of the pulsed fiber laser is 1064 nm, the pulse width is 10 - 200 ns, the repetition frequency is 20 - 100 kHz, the spot diameter d is 0.1 - 0.5 mm, the energy density is 1 - 5 J / cm², and the scanning speed is 1000 - 5000 mm / s; the capacitive sensor is a non-contact coplanar electrode structure with an electrode spacing ≤ 1 mm and an operating frequency of 1 - 10 MHz; more preferably, the pulse width is 50 ns, the repetition frequency is 20 kHz, the spot diameter d is 0.5 mm, the energy density is 2 J / cm², and the scanning speed is 1500 mm / s.

[0018] In step (3), according to the dielectric constant of PMMA (ε ≈ 3 - 4) and ITO (ε ≈ 9 - 10), ΔC_threshold is set to 30% - 50% of C_initial.

[0019] The present invention realizes the all-round processing and cleaning of large-sized special-shaped transparent materials through a pulsed fiber three-dimensional five-axis cleaning device, effectively improving the cleaning efficiency, and enhancing the stability and reliability of the surface removal process, and is suitable for laser cleaning of metal films (ITO) on transparent parts (the material is polymethyl methacrylate PMMA). BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present invention will be further described below with reference to the accompanying drawings.

[0021] Figure 1 is a schematic structural diagram of the present invention; Figure 2 is a cleaning flow chart of the present invention.

[0022] In the figure, 1 is a computer, 2 is an X-axis assembly, 201 is an X-axis guide rail, 202 is an X-axis servo motor, 3 is a Y-axis assembly, 301 is a Y-axis guide rail, 302 is a Y-axis servo motor, 4 is a Z-axis assembly, 401 is a Z-axis guide rail, 402 is a Z-axis servo motor, 403 is a Z-axis seat, 404 is a mounting bracket, 5 is a laser controller, 6 is a pulsed fiber laser, 7 is a laser cleaning head, 8 is a capacitive sensor, 9 is an amplifier, 10 is a digital-to-analog converter, and 11 is a frame. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0023] In order to make the above objects, features, and advantages of the present invention more obvious and understandable, the following detailed description of the specific embodiments of the present invention will be given with reference to the accompanying drawings. Many specific details are set forth in the following description in order to fully understand the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this invention belongs. The terms used in the specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0025] The present invention will be described in detail below with reference to the accompanying drawings.

[0026] Embodiment 1: A cleaning device for a metal film layer on the surface of a large-sized special-shaped transparent material The device of this embodiment includes a frame 11, on which a three-dimensional five-axis system and a laser cleaning head 7 are installed. The three-dimensional five-axis system and the laser cleaning head 7 are respectively connected to a computer 1. The three-dimensional five-axis system includes an X-axis component 2, a Y-axis component 3, and a Z-axis component 4. The Y-axis component 2 includes two Y-axis guide rails 301 arranged in parallel on the frame 11, and a Y-axis servo motor 302 is installed at the end of the Y-axis guide rail 301; the X-axis component 2 includes an X-axis guide rail 201 with both ends respectively mounted on the two Y-axis guide rails 301, and an X-axis servo motor 202 is installed on one end of the X-axis guide rail 201; the Z-axis component 4 includes a Z-axis seat 403 connected to the X-axis guide rail 201 through a slider. A Z-axis guide rail 401 is provided on the Z-axis seat 403. A Z-axis servo motor 402 is installed above the Z-axis seat 403, and the output shaft of the Z-axis servo motor 402 is connected to the Z-axis guide rail 401, and the laser cleaning head 7 is installed on the Z-axis guide rail 401.

[0027] Among them, the X-axis guide rail 201, the Y-axis guide rail 301, and the Z-axis guide rail 401 are all ball screw structures. The screw shaft end of the ball screw structure is connected to the power output shaft of the servo motor through a coupling, and there is no need for a transmission link in the middle; correspondingly, both ends of the X-axis guide rail 201 are fixed on the Y-axis guide rail 301 through sliders and ball structures, and the Z-axis seat 403 is installed through the slider and the ball structure fixed on the X-axis guide rail 201, so that the Z-axis guide rail 401 is vertically fixed.

[0028] In this embodiment, a mounting bracket 404 is fixed on the Z-axis guide rail 401, and the laser cleaning head 7 is installed on the mounting bracket 404 through a flange.

[0029] The laser system mainly consists of a laser controller 5 and a pulsed fiber laser 6, and outputs a pulsed laser beam with a wavelength of 1064 nm. The pulsed fiber laser is connected to the laser controller through a communication line, and the laser controller 5 controls the pulsed fiber laser 6 to emit a laser beam.

[0030] The cleaning system mainly consists of a laser cleaning head 7 for cleaning operations. The light beam generated by the laser system is irradiated onto the metal film through the laser cleaning head 7. The laser cleaning head 7 is provided with an optical fiber interface and is connected to the pulsed fiber laser 6 through an optical fiber via this optical fiber interface. The laser beam is perpendicularly radiated onto the surface of the metal film via the laser cleaning head 7.

[0031] The control system mainly consists of a computer 1. The computer receives and analyzes data and executes preset logic. The computer 1 analyzes the capacitance signal, generates a laser energy adjustment instruction and a five-axis motion trajectory, dynamically regulates the working state of the pulsed fiber laser 6 according to the signal of the capacitance sensing real-time feedback system, and synchronously displays the capacitance sensing data and the cleaning progress. The computer 1 is connected to the laser controller 2 through a communication line.

[0032] The real-time feedback system mainly consists of a capacitance sensor 8, an amplifier 9 and an analog-to-digital converter 10. The capacitance sensor 8 is connected to the amplifier 9 through a communication line, and the amplifier 9 is connected to the computer 1 through the analog-to-digital converter 10. It is used to detect the change of the ITO film layer dielectric constant and generate a feedback signal, and measure the local dielectric constant change in real time through a non-contact capacitance electrode plate to trigger laser energy adjustment or termination.

[0033] Furthermore, the laser cleaning head 7 is mounted on the mounting bracket 404 through a flange and is coaxially aligned with the capacitance sensor 8; the frame 11 is fixed on the equipment base; the capacitance sensor 8 adopts a non-contact coplanar electrode structure, the electrode spacing ≤ 1 mm, the working frequency is 1 - 10 MHz, and it is fixed on the fixture of the laser cleaning head 7 and coaxially points to the cleaning area with the laser beam.

[0034] Embodiment 2: A method for cleaning a metal film layer on the surface of a large-sized special-shaped transparent material The cleaning device used in this embodiment is the device described in Embodiment 1, and its specific steps are as follows: S1: Set the laser parameters in the human-machine interface of the computer, mainly including: laser energy density, wavelength, pulse width, pulse repetition frequency, spot diameter d, laser power, scanning speed, capacitance threshold (C_threshold, corresponding to the dielectric constant critical value when the ITO film is completely removed); S2: Set the laser beam scanning path on the human-machine interface of the computer, and make the laser beam be able to perpendicularly radiate the metal film via the three-dimensional five-axis system. Turn on the pulsed fiber laser, and the laser beam irradiates the first cleaning site on the surface of the transparent part, and at the same time, the capacitance sensor starts to detect. When the ITO film exists, a strong coupling is generated due to the high conductivity between the electrodes, and the capacitance value is relatively high (the detection result is C_initial); as the film layer is removed, the dielectric constant of the PMMA drops suddenly, and the capacitance value gradually decreases to the capacitance threshold C_threshold. The real-time capacitance value (C_real) of the capacitance sensor is transmitted to the computer via the amplifier and the analog-to-digital converter; S3: The computer calculates the current capacitance difference ΔC = |C_initial - C_real| and compares it with the preset threshold ΔC_threshold: If ΔC < ΔC_threshold, it is determined that the ITO film has not been completely removed, and the pulsed fiber laser continues to operate; if ΔC ≥ ΔC_threshold, it is determined that the ITO film has been removed to the PMMA layer, and the computer immediately shuts down the pulsed fiber laser through the laser controller; Among them, according to the PMMA dielectric constant (ε≈3 - 4) and ITO (ε≈9 - 10), ΔC_threshold is set to 30% - 50% of C_initial; S4: After the laser stops, the computer sends an instruction to the three-dimensional five-axis system to drive the laser cleaning head to accurately move to the next cleaning site, and repeats the above "detection - cleaning - movement" cycle until the entire surface of the transparent part is covered or the preset maximum cleaning times are reached.

[0035] In this embodiment, the diameter of the large-sized special-shaped transparent material is 0.8 - 1.5 m, and the pulsed fiber laser is a pulsed fiber laser with an output wavelength of 1064 nm. The laser wavelength is 1064 nm, the pulse width is 10 - 200 ns, the repetition frequency is 20 - 100 kHz, the spot diameter is 0.1 - 0.5 mm, the energy density is 1 - 5 J / cm², and the scanning speed is 1000 - 5000 mm / s.

[0036] Currently, the traditional method for cleaning the metal film layer of large-sized special-shaped transparent materials is manual grinding with a cleaning agent. It is removed by manual grinding, which takes about 15 days, requires a long time, needs to be reworked multiple times, and it is difficult to ensure the quality stability and efficiency of the transparent parts with this operation method.

[0037] In this embodiment, the output wavelength of the pulsed fiber laser is 1064 nm, the pulse width is 10 - 200 ns, the repetition frequency is 20 - 100 kHz, the spot diameter d is 0.1 - 0.5 mm, the energy density is 1 - 5 J / cm², and the scanning speed is 1000 - 5000 mm / s This embodiment adopts this system and provides multiple cleaning modes within the parameter range. The specific cleaning conditions are as follows: Among them, the conventional cleaning mode is applicable to ITO films with medium thickness. The ITO film removal rate is ≥99.5%, and the surface roughness of the substrate is maintained at Ra<0.1μm. The high-efficiency cleaning mode is applicable to large flat areas and is used for mass production or emergency maintenance scenarios. Compared with the conventional cleaning mode, the cleaning efficiency is significantly increased by 30%. The high-precision protection mode is applicable to ultra-thin ITO films, and the substrate damage rate is<0.05%, which is applicable to high-precision scenarios.

[0038] In this embodiment, this system is used to perform laser cleaning on large-sized special-shaped transparent materials and compare it with traditional cleaning methods. The specific comparison results are as follows: Traditional manual cleaning relies on empirical operations and requires multiple reworks (3 - 5 times) to remove ITO residues. Moreover, it is easy to cause scratches on the substrate due to excessive polishing. In this embodiment, the dielectric constant change is detected in real time through a capacitance sensor. When ΔC≥threshold, the laser is immediately terminated. The ITO residue rate can be controlled at ≤0.5% with a single cleaning, and the light transmittance retention rate is ≥95%, approaching the original PMMA light transmittance of 92%.

[0039] Traditional methods are prone to generating scratches due to mechanical friction or PMMA microcracks caused by the penetration of chemical cleaners. In this embodiment, non-contact laser cleaning is adopted, combined with 1064 nm short pulses and low energy density, to avoid the expansion of the heat-affected zone. The surface roughness of the substrate Ra≤0.2μm, and the damage rate≤0.2%.

[0040] Through the closed-loop control of capacitance signals, the cleaning efficiency of the present invention is increased by 80% compared with traditional methods, and the comprehensive cost is reduced by 60%.

[0041] Through the closed-loop control of capacitance sensing and the coordinated movement of three-dimensional five-axis, the present invention realizes the precise layer-by-layer cleaning of the ITO film layer, solves the problems of low efficiency and high damage rate of traditional methods, provides an efficient and highly reliable solution for the cleaning of large-sized special-shaped transparent materials, and the comprehensive performance reaches the international leading level. It comprehensively surpasses traditional methods in terms of cleaning efficiency, precision, and substrate protection, meeting the high-standard requirements for the cleaning of large-sized special-shaped transparent parts.

[0042] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and the description of the present invention.

Claims

1. A large-scale metal film cleaning device for a special-shaped transparent material surface, comprising a frame (11), a three-dimensional five-axis system and a laser cleaning head (7) mounted on the frame (11), the three-dimensional five-axis system and the laser cleaning head (7) being connected to a computer (1) respectively, characterized in that: The three-dimensional five-axis system comprises an X-axis assembly (2), a Y-axis assembly (3) and a Z-axis assembly (4); the Y-axis assembly (3) comprises two Y-axis guide rails (301) arranged in parallel on a frame (11); a Y-axis servo motor (302) is installed at the end of the Y-axis guide rails (301); the X-axis assembly (201) comprises an X-axis guide rail (201) with two ends respectively mounted on the two Y-axis guide rails (301); an X-axis servo motor (202) is installed on one end of the X-axis guide rail (201); the Z-axis assembly (44) comprises a Z-axis seat (403) connected to the X-axis guide rail (201); the Z-axis guide rail (401) is arranged on the Z-axis seat (403); a Z-axis servo motor (402) is installed on the upper part of the Z-axis seat (403); an output shaft of the Z-axis servo motor (402) is connected to the Z-axis guide rail (401); and a laser cleaning head (7) is installed on the Z-axis guide rail (401).

2. The device for cleaning the metal film layer on the surface of a large-scale special-shaped transparent material according to claim 1, characterized in that: The X-axis guide rail (201), the Y-axis guide rail (301) and the Z-axis guide rail (401) are all ball screw structures; the screw shaft ends of the ball screw structures are connected to the power output shaft of the servo motor via a coupling; both ends of the X-axis guide rail (201) are fixedly mounted on the Y-axis guide rail (301) via a slider and a ball structure; and the Z-axis seat (403) is fixedly mounted on the X-axis guide rail (201) via a slider and a ball structure.

3. The device for cleaning the metal film layer on the surface of a large-scale special-shaped transparent material according to claim 1, characterized in that: A mounting bracket (404) is fixed on the Z-axis guide rail (401), and the laser cleaning head (7) is mounted on the mounting bracket (404) via a flange.

4. The device for cleaning the metal film layer on the surface of a large-scale special-shaped transparent material according to claim 1, characterized in that: The laser cleaning head (7) is provided with an optical fiber interface and is connected to the pulse optical fiber laser (6) via an optical fiber through the optical fiber interface. The pulse optical fiber laser (6) is connected to the laser controller (5) via a communication line.

5. The device for cleaning the metal film layer on the surface of a large-scale special-shaped transparent material according to claim 4, characterized in that: The laser controller (5) is connected to the computer (1) via a communication line; a capacitive sensor (8) coaxial with the laser cleaning head (7) is installed on the fixture of the laser cleaning head (7); the capacitive sensor (8) is connected to the amplifier (9) via the communication line; and the amplifier (9) is connected to the computer (1) via a digital-to-analog converter (10).

6. The device for cleaning the metal film layer on the surface of a large-scale special-shaped transparent material according to claim 1, characterized in that: The frame (11) is fixed on the equipment base.

7. A method for cleaning a metal film layer on the surface of a large-scale special-shaped transparent material based on the device of claim 1, characterized in that: The method comprises the following steps: (1) setting laser parameters and laser beam scanning path in the human-machine interface of the computer so that the laser beam radiates the metal film layer vertically; (2) turning on the pulsed fiber laser, irradiating the laser beam to the first cleaning position on the surface of the transparent part, and starting the capacitive sensor detection at the same time; when the ITO film exists, the electric field between the electrodes is strongly coupled due to the high conductivity, and the capacitance value is high, which is detected as C_initial; as the film layer is removed, the PMMA dielectric constant drops sharply, and the capacitance value gradually drops to the capacitance threshold C_threshold, and the real-time capacitance value C_real of the capacitive sensor is transmitted to the computer via the amplifier and the digital-to-analog converter; (3) the computer calculates the current capacitance difference The value ΔC=|C_initial-C_real| is compared with the preset threshold ΔC_threshold: if ΔC<ΔC_threshold, it is determined that the ITO film has not been completely removed and the pulse fiber laser continues to work; if ΔC≥ΔC_threshold, it is determined that the ITO film has been removed to the PMMA layer, and the computer immediately turns off the pulse fiber laser through the laser controller; (4) After the laser stops, the computer sends a command to the three-dimensional five-axis system to drive the laser cleaning head to move precisely to the next cleaning position and repeat the above steps (2) to (3) until the entire transparent surface is covered or the preset maximum number of cleaning times is reached.

8. The cleaning method according to claim 7, characterized in that: In step (1), the laser parameters include laser energy density, wavelength, pulse width, pulse repetition frequency, spot diameter d, laser power, scanning speed, and capacitance threshold C_threshold.

9. The cleaning method according to claim 7 or 8, characterized in that: In step (2), the output wavelength of the pulse fiber laser is 1064nm, the pulse width is 10-200ns, the repetition frequency is 20-100kHz, the spot diameter d is 0.1-0.5mm, the energy density is 1-5J / cm², and the scanning speed is 1000-5000mm / s; the capacitive sensor is a non-contact coplanar electrode structure with an electrode spacing of ≤1mm and an operating frequency of 1-10MHz.

10. The cleaning method according to claim 7, characterized in that: In step (3), ΔC_threshold is set to 30%-50% of C_initial according to the dielectric constant of PMMA and ITO.

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