Method for eliminating rainbow stripes after laser film removal of coated glass

Abstract

The present application relates to the technical field of coating glass laser film removing processing, and particularly discloses a method for eliminating rainbow stripes after laser film removing of coated glass, obtaining structure data of a collimating and homogenizing converter, calculating a focused light spot diameter, then obtaining scanning target data, calculating and determining a light spot center point interval value, obtaining a target area for eliminating rainbow stripes after laser film removing of coated glass on a sample material, and planning a line scanning path for the target area; then, based on the light spot center point interval value, obtaining a moving speed of the focused light spot emitted by the laser in the line scanning direction, then calculating a frequency value of the laser; finally, adjusting the frequency of the laser to the frequency value, then scanning along the line scanning path from the coordinate origin as a starting point at the moving speed, so that the film removing is more uniform and complete, the uneven state on the microscopic level is avoided, the generation of rainbow stripes is avoided, the operation is simple, the film removing efficiency is improved, and the safety hidden danger caused by glass breakage is avoided.

Description

Technical Field

[0001] This invention relates to the field of laser coating removal technology for coated glass, and specifically to a method for eliminating rainbow patterns after laser coating removal of coated glass. Background Technology

[0002] Low-E glass (Low Emissivity Glass) is a special type of glass that achieves its properties by coating the glass surface with a thin layer of metal oxide, a functional Ag layer, and other coatings. Coated glass is classified into single-silver, double-silver, and triple-silver types. A single-silver structure consists of 5-7 layers of metal oxide, Ag, and other coatings stacked together, with a total thickness of 80-100 nm. A double-silver structure consists of 9-11 layers of metal oxide, Ag, and other coatings stacked twice, with a total thickness of 160-200 nm. A triple-silver structure consists of 13-15 layers of metal oxide, Ag, and other coatings stacked three times, with a total thickness of 240-300 nm. The coating layer exhibits high transmittance of visible light and high reflectance of mid- and far-infrared rays, providing excellent heat insulation and good light transmission. However, the coating layer is susceptible to corrosion and oxidation when exposed to air. Therefore, in certain areas of the coated glass, the coating layer needs to be removed to prevent corrosion and oxidation.

[0003] Traditional methods for removing the coating layer from coated glass include the following: Before coating, a fixture is installed around the glass to isolate the areas that do not need coating with a mask. The glass clamps the mask and enters the coating equipment for coating. After the coating process is completed, the mask is removed. The operation is very inconvenient and different sizes and specifications of products require different masks, resulting in very low production efficiency. The film removal effect is achieved by rubbing the glass surface with a high-speed rotating resin wheel. Since the resin wheel and the glass surface are in hard contact, the stress generated at the contact point between the resin wheel and the glass can easily cause micro-cracks and scratches on the glass surface. Therefore, the scrap rate is high during processing. At the same time, the micro-cracks generated during processing will cause the entire glass to fail over time, or even break, causing safety hazards. The laser coating removal method involves a fiber infrared laser emitting light, which is transmitted through an optical system and its beam diameter is adjusted before entering a focusing lens for focusing. The focusing lens focuses the laser beam onto a very small point, forming a high-energy-density laser beam. When this focused laser beam irradiates the sample material, the laser energy causes localized ablation or oxidation reactions on the material surface, thereby removing the material or forming a mark. Current problems include low transmittance after coating removal, which is 3-5% lower than the original film, indicating residual film. Secondly, the existing optical scheme has defects, with varying light intensity in the central region and weaker light at the edges of the Gaussian spot, resulting in very uneven coating removal. Finally, the galvanometer's precision is insufficient at high speeds, leading to uneven line spacing and inconsistent film thickness. This results in an uneven glass surface after laser coating removal, with some areas having more film removed and others less, creating a prism-like effect. Under white light (sunlight), the different wavelengths of light with different refractive indices are separated into rainbow-like patterns composed of red, orange, yellow, green, cyan, blue, and violet colors. Therefore, in order to solve the rainbow pattern problem in existing laser coating removal technology, this solution proposes a method to eliminate the rainbow pattern after laser coating removal of coated glass. Summary of the Invention

[0004] The purpose of this invention is to provide a method for eliminating rainbow patterns after laser removal of coated glass, so as to solve the problems mentioned above.

[0005] The objective of this invention can be achieved through the following technical solutions: A method for eliminating rainbow patterns after laser removal of coated glass includes the following steps: Step 1: Obtain the structural data of the collimation and homogenization converter, and calculate the focused spot diameter d; Step 2: Acquire the scanning target data, calculate and determine the center point spacing value of the light spot, obtain the target area on the sample material to eliminate the rainbow pattern after laser removal of the coated glass, and plan the line scan path for the target area; Step 3: Based on the center-to-center distance value g, obtain the moving speed v of the laser's focused beam in the online scanning direction, and then calculate the laser's frequency value τ. Step 4: Adjust the laser frequency to the frequency value τ, and then scan along the line scan path starting from the origin at a moving speed v.

[0006] As a further aspect of the present invention: the calculation process for the focused spot diameter d is as follows: The incoming beam is irradiated by a fiber picosecond laser aligned to a homogenizer to obtain incoming beam data. The incident beam data includes: beam quality M 2Wavelength λ, collimator focal length γ, and incident beam diameter D; Then through The diameter d of the focused spot after collimation and homogenization converter is calculated.

[0007] As a further aspect of the present invention: the light source of the fiber picosecond laser is a green light source.

[0008] As a further aspect of the present invention: the focused light spot is a circular flat-topped light spot.

[0009] As a further aspect of the present invention: the scanned target data includes an overlap rate s.

[0010] As a further aspect of the present invention: the method for obtaining the center point spacing value of the light spot is as follows: To obtain the overlap rate s of adjacent focused spots, it should be noted that the overlap rate s refers to the degree of overlap of the areas covered by adjacent focused spots on the scanning path, and is set based on the requirements of processing quality, uniformity, and flatness; 0 < s < 100%; pass The distance g between the center points of the light spot is calculated.

[0011] As a further aspect of the present invention: the step of planning the line scan path for the target area is as follows: The origin of the coordinate system is the endpoint of the target area, the scanning direction of the focused spot is the x-axis, and the displacement direction perpendicular to the scanning direction is the y-axis. It should be noted that the displacement direction refers to the direction in which the scanning beam moves to the next line after scanning the target area through the focused spot. Then, with the origin of the coordinate system as the first focused light spot, the target area is determined by the light spot spacing value g, which is the unit spacing. Starting from the origin, the x-axis is used as the scanning direction to form the line scan path until the end of the current line scan direction. Then, the y-axis is used for spacing displacement, with a displacement distance of g. The x-axis is used as the scanning direction again to form the line scan path until the end of the light spot in both the x-axis and y-axis directions.

[0012] As a further aspect of the present invention: the frequency value τ of the laser is calculated as follows: .

[0013] As a further aspect of the present invention: the focused light spot is a rectangular flat-topped light spot.

[0014] As a further aspect of the present invention: the collimation and homogenization converter comprises a structured waveplate and two linear polarizers, which are externally disposed within a sleeve via a pressure ring and are disposed within a lens sleeve.

[0015] The beneficial effects of this invention are: In this invention, the structural data of the collimation and homogenization converter is acquired to calculate the diameter of the focused spot. Then, the scanning target data is acquired to calculate and determine the center-point spacing of the spot. The target area for removing rainbow patterns from the coated glass sample material after laser removal is obtained, and a line scan path is planned for the target area. Then, based on the center-point spacing of the spot, the moving speed of the laser-emitted focused spot in the line scan direction is obtained, and the frequency value of the laser is calculated. Finally, the frequency of the laser is adjusted to the specified value, and then scanning is performed along the line scan path starting from the origin of the coordinate system at the moving speed. This homogenizes the energy distribution of the Gaussian spot and pre-plans the travel path of the galvanometer, making the line spacing highly consistent, resulting in more uniform and thorough removal of the coating. This avoids unevenness at the microscopic level, prevents the generation of rainbow patterns, simplifies the operation, improves the efficiency of coating removal, and avoids the safety hazards caused by glass breakage. Attached Figure Description

[0016] The invention will now be further described with reference to the accompanying drawings.

[0017] Figure 1 This is a schematic diagram of the method flow of the present invention; Figure 2 This is a schematic diagram of the collimation and homogenization converter structure in this invention; Figure 3 This is a schematic diagram of the beam collimation and homogenization effect in this invention; Figure 4 This is a schematic diagram of the film removal path of the circular flat-top light spot in this invention; Figure 5 This is a schematic diagram of the rectangular flat-top light spot film removal path in this invention. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] Please see Figure 1 and Figure 4 As shown, the present invention provides a method for eliminating rainbow patterns after laser removal of coated glass, comprising the following steps: Step 1: Obtain the structural data of the collimation and homogenization converter, and calculate the focused spot diameter d; Specifically, the calculation process for the focused spot diameter d is as follows: The incoming beam is irradiated by a fiber picosecond laser aligned to a homogenizer to obtain incoming beam data. The incident beam data includes: beam quality M 2 Wavelength λ, collimator focal length γ, and incident beam diameter D; Then through The diameter d of the focused spot after collimation and homogenization converter is calculated; From the absorption spectrum, since the coated film absorbs green light better than infrared light, a green light source with a wavelength of 532 nm is chosen as the light source. The film may be composed of at least one of Zn, Sn, Ti, Nb, Zr, Hf, Mg, Ni, In, Al, Ga, W, Bi metal oxides and mixtures thereof, or at least one of Si, Al, Zr, Ti, Y, Hf, Nb, Ta metal nitrides or nitrides and mixtures thereof. The atoms are connected by covalent bonds with very high bond energies, so a very high peak power is required to break the covalent bonds and remove the film. The peak power of a fiber picosecond laser is 1000 times higher than that of a nanosecond laser, making it a relatively suitable choice. The laser parameters are: a 60W-80W fiber picosecond laser with a pulse width of 10-15 ps. 2 <1.2, frequency 100KHz-10MHz; Gaussian spot homogenization to flat-top spot, spot shaping and homogenization scheme as follows Figure 1 The collimation and homogenization converter achieves beam homogenization and shaping based on the principle of spatial local light attenuation, transforming a beam with a Gaussian distribution into a beam with a flat-top intensity distribution. Step 2: Acquire the scanning target data, calculate and determine the center point spacing value of the light spot, obtain the target area on the sample material to eliminate the rainbow pattern after laser removal of the coated glass, and plan the line scan path for the target area; Specifically, the scanned target data includes the overlap rate s; The method for obtaining the center-to-center distance value of the light spot is as follows: S21: Obtain the overlap rate s of adjacent focused spots. It should be noted that the overlap rate s refers to the degree of overlap of the areas covered by adjacent focused spots on the scanning path, and is set based on the requirements of processing quality, uniformity and flatness; 0 < s < 100%; S22: Through The distance g between the center points of the light spot was calculated. The steps for line scan path planning for the target area are as follows: S31: The endpoint of the target area is taken as the origin of the coordinate system, the scanning direction of the focused spot is taken as the x-axis, and the displacement direction perpendicular to the scanning direction is taken as the y-axis. It should be noted that the displacement direction refers to the direction in which the scanning beam moves to the next line after scanning the target area through the focused spot. S32: Then, using the origin of the coordinate system as the first focused light spot, the target area is determined by using the light spot center point spacing value g as the unit spacing; S33: Starting from the origin of the coordinate system, the x-axis direction is used as the scanning direction to form the line scan path until the end of the current line scan direction. Then, the y-axis is used for spacing displacement, with a displacement distance of g. The x-axis direction is used as the scanning direction to form the line scan path until the end of the spot in both the x-axis and y-axis directions. Step 3: Based on the center-to-center distance value g, obtain the moving speed v of the laser's focused beam in the online scanning direction, and then calculate the laser's frequency value τ. Specifically, the frequency value τ of the laser is calculated as follows: ; Step 4: Adjust the laser frequency to the frequency value τ, and then scan along the line scan path starting from the origin at a moving speed v; For example, using a high-precision galvanometer and focusing system, the focused spot size is approximately 100µm. Line scanning is performed at a speed of 25m / s. After scanning one line, the galvanometer moves by the same line spacing, i.e., the center point spacing value g, and performs line scanning again. This galvanometer can maintain the uniformity of the filling line spacing at high speed. Finally, by focusing through a field lens, a focused spot with high peak power and high energy density is obtained to achieve rapid and thorough removal of the film layer without damaging the glass substrate, suppressing the conditions for the formation of rainbow patterns, and improving light transmittance. By shaping the laser beam, the energy distribution of the Gaussian spot is homogenized, and the travel path of the galvanometer is planned in advance, resulting in a highly consistent line spacing. This makes the film removal more uniform and thorough, avoiding unevenness at the microscopic level and preventing the formation of rainbow patterns. The operation is simple, improving the efficiency of film removal and avoiding safety hazards caused by glass breakage.

[0020] Example 1: Based on the above examples, this example provides a structure for a collimation and homogenization converter, as detailed below. Figure 2 As shown, the collimation and homogenization converter consists of one structured waveplate and two linear polarizers, externally mounted inside a sleeve via a pressure ring, presenting a three-piece flat structure of "upper and lower polarizing films + middle LCP functional film layer". The product is installed inside a standard lens sleeve. This shaping DOE is composed of a structured waveplate and two parallel linear polarizers at a certain angle. Linearly polarized light passes through the structured waveplate to generate vector polarized light, and then passes through the subsequent polarizer to attenuate the intensity of the Gaussian portion of the light, thereby achieving collimation and homogenization of the beam.

[0021] In a collimation and homogenization converter, a structured waveplate achieves different fast-axis distributions of liquid crystal molecules in the radial direction through optically controlled orientation, thereby converting incident ray-polarized light into vector-polarized light. After passing through a polarizer with the same transmission direction, the polarized light in different regions undergoes varying degrees of attenuation, thus achieving collimation and homogenization of the beam. The homogenization effect is as follows: Figure 3 As shown, Figure 3 The black curve represents the unshaped beam, and the red curve represents the shaped beam. It can be seen that the energy distribution of the shaped beam is relatively uniform. The diameter of the homogenized beam is about 5mm. After being focused by the field lens through a high-speed, high-precision galvanometer, the diameter of the focused beam is calculated as in step one of the embodiments.

[0022] Example 2: Based on the above examples, this embodiment provides a beam shaping scheme to shape a circular flat-top beam spot into a rectangular flat-top beam spot, such as... Figure 5 As shown, the spot size is 100um*300um, the film removal efficiency is increased by 3 times, and the film removal is smoother, further reducing the generation of rainbow patterns.

[0023] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0024] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0025] In the embodiments disclosed in this application, it should be understood that the disclosed devices / terminal equipment and methods can be implemented in other ways. For example, the device / terminal equipment embodiments described above are merely illustrative. For instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual coupling or direct coupling or communication connection may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms.

[0026] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0027] The foregoing has provided a detailed description of one embodiment of the present invention, but this description is merely a preferred embodiment and should not be construed as limiting the scope of the invention. All equivalent variations and modifications made within the scope of the claims of this invention should still fall within the patent coverage of this invention.

Claims

1. A method for eliminating rainbow patterns after laser removal of coated glass, characterized in that, Includes the following steps: Step 1: Obtain the structural data of the collimation and homogenization converter, and calculate the focused spot diameter d; Step 2: Acquire the scanning target data, calculate and determine the center point spacing value of the light spot, obtain the target area on the sample material to eliminate the rainbow pattern after laser removal of the coated glass, and plan the line scan path for the target area; Step 3: Based on the center-to-center distance value g, obtain the moving speed v of the laser's focused beam in the online scanning direction, and then calculate the laser's frequency value τ. Step 4: Adjust the laser frequency to the frequency value τ, and then scan along the line scan path starting from the origin at a moving speed v.

2. The method for eliminating rainbow patterns after laser removal of coated glass according to claim 1, characterized in that, The calculation process for the focused spot diameter d is as follows: The incoming beam is irradiated by a fiber picosecond laser aligned to a homogenizer to obtain incoming beam data. The incident beam data includes: beam quality M 2 Wavelength λ, collimator focal length γ, and incident beam diameter D; Then through The diameter d of the focused spot after collimation and homogenization converter is calculated.

3. The method for eliminating rainbow patterns after laser removal of coated glass according to claim 2, characterized in that, The light source for the fiber optic picosecond laser is a green light source.

4. The method for eliminating rainbow patterns after laser removal of coated glass according to claim 2, characterized in that, The focused spot is a circular, flat-topped spot.

5. The method for eliminating rainbow patterns after laser removal of coated glass according to claim 1, characterized in that, The scanned target data includes the overlap rate s.

6. The method for eliminating rainbow patterns after laser removal of coated glass according to claim 5, characterized in that, The method for obtaining the center-point spacing value of the light spot is as follows: To obtain the overlap rate s of adjacent focused spots, it should be noted that the overlap rate s refers to the degree of overlap of the areas covered by adjacent focused spots on the scanning path, and is set based on the requirements of processing quality, uniformity and flatness. 0＜s＜100%； pass The distance g between the center points of the light spot is calculated.

7. The method for eliminating rainbow patterns after laser removal of coated glass according to claim 6, characterized in that, The steps for line scan path planning in the target area are as follows: The origin of the coordinate system is the endpoint of the target area, the scanning direction of the focused spot is the x-axis, and the displacement direction perpendicular to the scanning direction is the y-axis. It should be noted that the displacement direction refers to the direction in which the scanning beam moves to the next line after scanning the target area through the focused spot. Then, with the origin of the coordinate system as the first focused light spot, the target area is determined by the light spot spacing value g, which is the unit spacing. Starting from the origin, the x-axis is used as the scanning direction to form the line scan path until the end of the current line scan direction. Then, the y-axis is used for spacing displacement, with a displacement distance of g. The x-axis is used as the scanning direction again to form the line scan path until the end of the light spot in both the x-axis and y-axis directions.

8. The method for eliminating rainbow patterns after laser removal of coated glass according to claim 1, characterized in that, The frequency value τ of the laser is calculated as follows: .

9. The method for eliminating rainbow patterns after laser removal of coated glass according to claim 2, characterized in that, The focused spot is a rectangular flat-topped spot.

10. The method for eliminating rainbow patterns after laser removal of coated glass according to claim 1, characterized in that, The collimation and homogenization converter consists of a structured waveplate and two linear polarizers, which are externally mounted inside a sleeve via a pressure ring and are located inside a lens sleeve.

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