Laser etching system and method

Abstract

The present disclosure provides a laser etching system and method for etching a bottle. An example laser etching system includes a laser light source to generate a laser beam; and a guiding system for guiding the laser beam emitted by the laser light source. The guiding system comprises a 3D galvanometer system used for adjusting the position of the focus of the laser beam. The laser etching system further includes a holding system for holding the bottle in a fixed position during the laser etching and releasing the bottle after the laser etching. The laser etching system further includes a control system for generating a set of control signals from the 3D model of the bottle. The control signal is used to control the guidance system to dynamically adjust the position of the focus such that the focus of the laser beam is located at a predetermined position of the surface of the bottle.

Description

Cross-references to related applications

[0001] This application claims the benefit of Chinese Patent Application No. 2023224783826, filed with the China National Intellectual Property Administration (CNIPA) on September 12, 2023, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0002] This disclosure relates to laser etching or laser marking, particularly to a laser etching system or laser marking system, and even more particularly to a laser etching system or laser marking system for etching or marking bottles (such as beverage bottles). background

[0003] Laser etching, or laser marking, is a technique that uses a high-energy pulsed laser beam to irradiate the surface of an object with a focused laser to create etched marks. The use of laser etching may cause the surface layer material to vaporize or undergo a discoloration chemical reaction; it etches fine grooves with both width and depth on the surface of an object to form text, symbols, logos, or images, for example, displayed on the surface of a part or product.

[0004] In the packaging manufacturing industry, laser etching is increasingly used for marking the surfaces of packaged products. For conventional laser etching systems, the etching laser can only be controlled via the X-axis and the Y-axis, which is orthogonal to the X-axis, during the etching process. However, when using this type of laser etching system to mark packaged products, the relatively complex surface shape of the packaging itself means that the focus of the etching laser cannot always be located at the desired etching position, thus affecting the absorption of the etching laser energy. For example, if the image to be etched on a cylindrical package is wider in a direction perpendicular to its longitudinal direction, the focus of the etching laser will not always fall on the surface of the packaged product during the etching process, and if the focus position extends beyond acceptable tolerances, the etching effect will be unsatisfactory.

[0005] To alleviate this problem, a known method in the prior art, such as rotating the packaged product, ensures that the focus of the etching laser is always located on the surface to be etched, directly facing the laser, thereby improving the etching effect. However, in the etching process, rotating the packaged product in coordination with the etching laser requires precise control over the rotation of the rotating equipment itself and the position of the packaged product relative to the laser focus. Figure 1A and Figure 1B Etched images formed using a method according to this type of prior art are shown separately. The etched image is divided into two visually separate parts, wherein the packaged product is rotated and each part is etched separately, then joined together to obtain a complete etched image. From Figure 1A and Figure 1BAs can be seen, the two separate parts of the image are not at the same height or are separated by a large gap, thus disrupting the integrity or coherence of the image. Therefore, this etching method still cannot achieve a satisfactory etching effect.

[0006] In addition, packaged products sometimes have unique shapes and structures, such as ribbed sections, ring-shaped sections, or flat sections, etc. Figure 2 As shown. When etching surfaces in different areas of such packaged products, the design space can be severely limited if the focal length extends beyond acceptable tolerances. Summary of the Invention

[0007] This disclosure provides techniques for laser etching of packaged products (particularly bottles) without rotating them. These techniques allow for adjustment of the focus of the etching laser to fit the shape of the bottle, thereby achieving a clear etched image over a larger etching range.

[0008] According to some embodiments of this disclosure, a laser etching system is provided. The laser etching system includes: a laser source operable and configured to generate and emit an etching laser beam; a guiding system operable and configured to guide the etching laser beam emitted by the laser source, the guiding system including a three-dimensional (3D) galvanometer system for adjusting the position of the focal point of the etching laser beam; a holding system operable and configured to acquire a bottle before laser etching begins, hold the bottle in place during laser etching, and release the bottle after laser etching; and a control system operable and configured to generate a set of control signals based on a 3D model of the bottle to control the guiding system such that the focal point of the etching laser beam is dynamically adjusted and positioned at a predetermined location on the surface of the bottle to be patterned, for etching the bottle and forming a pattern. In some embodiments, the bottle has a curved surface about a longitudinal axis of the bottle, and the 3D galvanometer system is configured to adjust the focal point within a focal range along the incident direction of the laser beam relative to the bottle.

[0009] According to one aspect of this disclosure, the laser etching system is used to laser etch the body of a beverage bottle. The beverage bottle can be a plastic bottle, glass bottle, metal bottle, beverage can, etc. The plastic bottle can be a PET bottle.

[0010] According to one aspect of this disclosure, the laser source may be a UV laser, a fiber laser, a CO2 laser, or a picosecond laser.

[0011] According to one aspect of this disclosure, the 3D galvanometer system includes: an X-axis galvanometer scanner and a Y-axis galvanometer scanner for adjusting the optical path of a laser beam emitted by a laser source; and a Z-axis adjustment system for adjusting the focal point (i.e., focal length) of the laser beam along the Z-axis.

[0012] According to one aspect of this disclosure, when the diameter of the beverage bottle body is 60 mm, the etching width of the clear etched design or pattern produced on the beverage bottle body by the laser etching system according to this disclosure is in the range of 45 mm to 50 mm.

[0013] According to one aspect of this disclosure, when the diameter of the beverage bottle body is 60 mm, the focal range of the laser etching system according to this disclosure on the beverage bottle body along the incident direction of the laser beam relative to the bottle is ±4.0 mm to ±4.9 mm.

[0014] By using the laser etching system provided in this disclosure, the focus of the etching laser can be adjusted to fit the shape of the beverage bottle, thereby increasing the maximum etching width of the resulting clear etched design on the bottle by 40%, increasing the focus tolerance by 40%, and obtaining the desired outward appearance of the beverage bottle. Attached Figure Description

[0015] The contents of this disclosure are described in detail below with reference to the accompanying drawings. In the accompanying drawings:

[0016] Figure 1A and Figure 1B Examples of overall etched images obtained by performing connected laser etching on the body of a rotating beverage bottle using laser etching according to the prior art are shown.

[0017] Figure 2 An example beverage bottle with a unique shape and uneven surface is shown.

[0018] Figure 3A and Figure 3B Etching images using laser etching according to existing technology at different contrasts are shown respectively.

[0019] Figure 4 Examples of etched images formed on a rotating beverage bottle using laser etching at different etching speeds according to existing technology are shown.

[0020] Figure 5 This is a schematic diagram showing an example focus of the etching laser.

[0021] Figure 6A schematic diagram illustrating an example laser etching system according to various embodiments of this disclosure is shown.

[0022] Figure 7A This is a schematic diagram showing a cross-section of the bottle.

[0023] Figure 7B This is a schematic diagram showing the focal range of a laser beam used to etch the curved surface of a bottle.

[0024] Figure 8 Example etched images are shown, formed using laser etching with different etch widths according to existing technology.

[0025] Figure 9A and Figure 9B Etched images formed using laser etching according to the prior art and etched images formed using laser etching according to this disclosure are shown respectively.

[0026] Figure 10 This is a block diagram illustrating example methods for laser etching bottles according to various embodiments of this disclosure. Detailed Implementation

[0027] The following description only briefly outlines certain exemplary embodiments. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of this disclosure. Therefore, the drawings and description are intended to be largely exemplary and non-limiting.

[0028] In the description of this disclosure, it must be understood that the orientations or positional relationships indicated by terms such as “center,” “longitudinal,” “lateral,” “length,” “width,” “thickness,” “upper,” “lower,” “front,” “rear,” “left,” “right,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” “outer,” “clockwise,” and “counterclockwise” are based on the orientations or positional relationships shown in the accompanying drawings and are intended only for the convenience of describing this disclosure and for simplifying the description, and are not intended to indicate or imply that the mentioned devices or elements must have a particular orientation or be constructed and operated in a particular orientation, and therefore should not be construed as limiting the disclosure. Furthermore, the terms “first” and “second” are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of mentioned technical features. Therefore, a feature defined as “first” or “second” may explicitly or implicitly include one or more of the stated features. In the description of this disclosure, “a plurality” means two or more than two, unless otherwise explicitly defined.

[0029] In the description of this disclosure, it must be explained that, unless otherwise expressly stated and defined, the terms "installation," "interconnection," and "connection" should be understood in a broad sense, for example, meaning a connection that can be fixed, detachable, or integral; a connection that can be mechanical, electrical, or interconnected; a direct interconnection or an indirect interconnection via an intermediate medium; or a connection within two components or an interaction between two components. For those skilled in the art, the specific meaning of the above terms in this disclosure can be understood according to the specific circumstances.

[0030] The embodiments of this disclosure are described below with reference to the accompanying drawings; it should be understood that the embodiments described herein are intended to illustrate and describe the disclosure only, and not to limit the disclosure.

[0031] In laser etching processes, several factors affect the image quality of laser etching; these factors include, but are not limited to, one or more of the following:

[0032] Contrast: To improve visibility, a greater contrast is needed between the material color and the etched color. Figure 3A and Figure 3B Etched images with high and low contrast are shown respectively; it can be seen from these images that the etched image with higher contrast has deeper colors and is clearer. For laser etching systems, contrast can be increased by using higher etching laser energy. Alternatively, higher energy can be obtained by increasing the power of the laser source.

[0033] Etching speed: The speed at which the etching laser moves relative to the surface to be etched affects the etching process. Faster laser movement reduces etching time but reduces the absorption of etching energy, resulting in lower image contrast / resolution. Figure 4 The etched images are shown from top to bottom, with the etch speed gradually increasing from 500 mm / s to 2000 mm / s. It can be seen that as the etch speed increases incrementally, the contrast of the etched image decreases incrementally, resulting in an incremental decrease in the resolution of the etched image; the etched image at the lowest etch speed is the clearest. Therefore, the goal of etching is to increase the etch speed while maintaining the same level of contrast.

[0034] Focus position: Figure 5A schematic diagram of the focal position of the etching laser is shown. During the focusing process of the etching laser, the laser beam passing through the lens converges in a conical shape; the focal point is located at the apex of this conical shape, i.e., the location where the highest energy converges. During etching, the desired location of the focal point of the etching laser is always on the surface of the object being etched. For a typical laser etching system, the etching quality is still considered acceptable if the distance between the surface of the object to be etched and the focal point is within approximately ±1.5 mm.

[0035] Figure 6 A schematic diagram of a laser etching system 100 according to this disclosure is shown. The laser etching system 100 is used to laser etch the body of a bottle 200 (e.g., a beverage bottle) and includes: a laser source 110, a guiding system 120, a holding system 130, and a control system 140.

[0036] Laser source 110 is used to generate and emit laser beam 112, and the power of the laser source determines the energy of the etching laser beam that can be generated therefrom. Laser source 110 used in this disclosure may include, for example, a UV laser, a fiber laser, a CO2 laser, a picosecond laser, etc.

[0037] A guiding system 120 is used to guide the etching laser beam emitted by the laser source 110 and includes a 3D galvanometer system 121. The 3D galvanometer system 121 is operable and configured to dynamically adjust the position of the focal point of the etching laser beam to fit the shape of the bottle 200 to be etched. In some embodiments, the 3D galvanometer system 121 includes one or more 3D galvanometers. In addition to controlling the optical path of the etching laser beam along the X-axis and the Y-axis perpendicular to the X-axis, the 3D galvanometer system 121 further includes components for controlling the optical path in the Z-axis direction, namely, a Z-axis adjustment system 122 for adjusting the focal point of the laser beam. Specifically, this is achieved by arranging a Z-axis lens (or a set of Z-axis lenses) 122a along the Z-axis for dynamically adjusting the focal point of the etching laser beam; this Z-axis lens (or set of Z-axis lenses) 122a performs a reciprocating linear motion along the optical path in the Z-axis direction to compensate for focusing errors in real time. This dynamic focusing can compensate for any curvature or irregularities on the surface of the bottle 200 to achieve consistent etching quality. According to the 3D galvanometer system 121 disclosed herein, an X-axis galvanometer scanner 123 and a Y-axis galvanometer scanner 124 may be respectively set on the X-axis and Y-axis; the X-axis galvanometer scanner 123 and the Y-axis galvanometer scanner 124 are used to adjust the optical path of the etching laser beam.

[0038] In some embodiments, the X-axis galvanometer scanner 123 includes one or more movable or rotatable galvanometer mirrors 123a and galvanometer motors 123b. Similarly, the Y-axis galvanometer scanner 124 includes one or more movable or rotatable galvanometer mirrors 124a and galvanometer motors 124b. The galvanometer mirrors 123a and 124a are driven by the galvanometer motors 123b and 124b, respectively, to move or rotate in response to an electrical signal (i.e., a control signal) to reflect and precisely control the direction of the laser beam. The Z-axis adjustment system 122 further includes one or more lenses 122a arranged in the Z-axis direction and a lens motor 122b configured to control one or more lenses 122a to adjust the focal point of the laser beam in the Z-axis direction. In some embodiments, the lens motor 122b can control one or more Z-axis lenses to perform reciprocating linear motion in the Z-axis direction. In some embodiments, the Z-axis direction is the incident direction of the laser beam relative to the bottle 200.

[0039] The control system 140 may include an association module 141 and a drive module 142. The association module 141 is operable and configured to acquire a 3D model of the bottle 200 and, based on the 3D model, generate a set of control signals for the guiding system 120 to control the guiding system 120 such that the focus of the etching laser beam is adjusted to a predetermined position on the bottle body of the desired pattern or design to etch the bottle body and form the design pattern. The control signals determine the position (e.g., [X, Y, Z] coordinate position) where the etching laser beam needs to be focused and etched. The drive module 142 is operable and configured to drive the X-axis galvanometer scanner 123 (e.g., galvanometer motor 123b), the Y-axis galvanometer scanner 124 (e.g., galvanometer motor 124b), and the Z-axis adjustment system (e.g., lens motor 122b) based on the control signals, such that the etching laser beam, after being emitted from the laser source 110, undergoes dynamic focusing on the Z-axis and reflection twice on the X and Y axes, ultimately reaching the area to be etched on the bottle body of the bottle 200. Preferably, via dynamic control of the control system 140, the focal position of the etching laser beam is controlled to be located on the area to be etched on the body of the bottle 200 within the focal range along the incident direction of the laser beam relative to the bottle 200.

[0040] In some embodiments, the control system 140 may include a computing system or computing device 143. The association module 141 and the drive module 142 may each be a device (e.g., a mechanical or electrical device) coupled to and controlled by the computing system 143, or alternatively, a software program implemented on the computing device 143 of the control system 140. In some embodiments, the association module 141 may scan the bottle 200 to obtain a set of position coordinates (e.g., [X, Y, Z] coordinates) defining the surface of the bottle 200. The association module 141 may further determine position coordinates (e.g., [X, Y, Z] coordinates) of a desired pattern or design to be formed on the surface of the bottle. These predetermined positions are the locations where the focus of the laser beam is controlled during etching. In some embodiments, the association module 141 may further calculate an etching path (e.g., a path for moving the focus of the laser beam) on the surface of the bottle 200. The etching path may include a set of predetermined position coordinates (e.g., [X, Y, Z] coordinates) for the focus to move across the surface. Due to the curvature of the surface, the predetermined position coordinates of the etching path may vary in the Z-axis direction. The association module 141 can generate a set of control signals and send these control signals to the drive module 142. When the incident direction of the laser beam onto the bottle 200 is along the Z direction, the Z-axis adjustment system 122 can be controlled to adjust the focus of the laser beam along the Z direction according to the control signals including the predetermined position coordinates of the etching path, so that the focus of the laser beam can be precisely and accurately positioned at the predetermined position of the desired pattern.

[0041] According to embodiments of this disclosure, the holding system 130 is operable and configured to hold the bottle 200 prior to laser etching, hold the bottle 200 in place during laser etching to ensure precise and accurate etching, and release the bottle 200 after laser etching. In some embodiments, the holding system may include a robotic arm programmed to pick up the bottle 200, securely hold the bottle in place during the laser etching process, and then release the bottle once the process is complete. The robotic arm may be equipped with various end effectors (e.g., grippers) designed to handle bottles of different shapes and sizes. Other examples of holding systems include mechanical clamps, fixtures or jigs, vacuum suction cups, etc.

[0042] According to embodiments of this disclosure, bottle 200 is a PET bottle or beverage can. Other bottles made of plastic, metal, or other etchable materials are also within the scope of this disclosure.

[0043] Figure 7A This is a schematic cross-sectional view of the bottle body according to an embodiment of this disclosure. In the example shown, when a bottle with a body diameter of 60 mm is laser-etched based on the following perimeter calculation formula:

[0044]

[0045] The circumference C of the beverage bottle is calculated to be 188.4 mm. When using a conventional laser etching system according to the prior art, the resulting etching width W is typically in the range of 25 mm to 30 mm.

[0046] Based on the calculation formula for etching angle

[0047]

[0048] Calculate the upper and lower limits of the actual etching angle achieved:

[0049] α1 = W1 / C 360° = 25 mm / 188.4 mm 360° = 48°, and

[0050] α2 = W2 / C 360° = 30 mm / 188.4 mm 360° = 57°.

[0051] In addition, according to the etching height calculation formula

[0052]

[0053] The upper and lower limits of the effective etching height can be calculated, and are as follows:

[0054] H1 = d / 2 - cos(α1 / 2) d / 2 = cos(48° / 2) 60 mm / 2 = 2.6 mm, and

[0055] H2 = d / 2 - cos(α2 / 2) d / 2 = cos(57° / 2) 60 mm / 2 = 3.6 mm.

[0056] Therefore, the focal range (± H / 2) of the etching laser in a laser etching system according to the prior art is calculated to be ± 1.3 mm to ± 1.8 mm; this focal range specifically depends on the balance between etching quality and etching speed. For example, if better quality is more important and etching speed is less important, etching within the "focal range of ± 1.3 mm" can be selected.

[0057] like Figure 7BAs shown, when using a laser beam to etch the curved surface of bottle 200, the incident direction of the laser beam is perpendicular to the Z-axis direction of the bottle 200 surface. For example, the laser beam moves in the Y-axis direction (or XY plane), following an etching path including starting position 701, along positions 702, 703, 704 to ending position 705, to form a pattern on the curved area of ​​the bottle. Each position is represented by a set of [X, Y, Z] coordinates, and the coordinates of the position vary along the Z-axis direction. For example, the Z-coordinate of the starting position 701 is lower than the Z-coordinates of positions 702 and 703. The focus of the laser beam on the surface can be adjusted by the Z-axis adjustment system 122 to change within a focus range (H) along the Z-axis direction and adapt to the curvature of the curved area, such that the focus of the laser beam can be precisely positioned at positions 701 to 705 as the laser beam moves from the starting position 701 to the ending position 705. During etching, the incident direction of the laser beam can be maintained in the Z-axis direction.

[0058] like Figure 8 As shown, laser etching systems according to existing technology are typically capable of achieving clear etching with an etching width W between approximately 25 mm and 30 mm. (Viewed from top to bottom) Figure 8 As the etch width W reaches and exceeds 30 mm, for example when it equals 33 mm, the edges in the width direction W of the etched image become increasingly blurry or unclear, and this defect mark affects the appearance of the product.

[0059] In contrast, when etching the bottle body using the laser etching system according to this disclosure, the etching width W can be increased to 45 mm to 50 mm because the focal range relative to the bottle surface in the Z-axis direction can be adjusted over a wider range (i.e., ± 4.0 mm to ± 4.9 mm). Figure 9A and Figure 9B The etching width of the etched image achieved by the laser etching system according to the prior art is 28 mm, which is a relatively small etching size. However, the etching width W of the etched image achieved by the laser etching system according to this disclosure can be 50 mm, almost doubling the etching size. Using the same calculation method and formulas (1)-(3) as described above, the focal range of laser etching on the bottle body according to this disclosure is also increased to ±4.0 mm to ±4.9 mm.

[0060] Therefore, compared with laser etching systems according to the prior art, the beneficial technical effects achieved by using the laser etching system according to this disclosure include:

[0061] 1. Increase the etching width of the etched image by 40%.

[0062] 2. Increase focus tolerance by 40%.

[0063] 3. While achieving the desired etching effect, the etching rate is affected to some extent, but still within an acceptable range.

[0064] Figure 10 An example method 1000 for etching a bottle, performed by a laser etching system according to this disclosure, is shown. In the illustrated example, method 1000 includes process blocks 1010 to 1050. At 1010, the bottle to be etched is identified and held in a fixed position by a holding system of the laser etching system. The holding system securely holds the bottle in place. In some embodiments, the bottle or the area of ​​the bottle to be etched has a curved or bent surface about the longitudinal or extending direction of the bottle.

[0065] At position 1020, the control system of the laser etching system generates control signals. In some embodiments, an association module of the control system obtains a 3D model of the bottle. The 3D model includes all necessary surface contours and dimensions of the bottle, the area to be etched, and the desired or to be formed pattern. The association module generates a set of control signals based on these control signals. The control signals include the coordinates [X, Y, Z position] of the area to be etched, the desired pattern, and the focusing instructions required for the laser beam to etch the surface of the bottle and form the desired pattern in the area to be etched. Depending on the material and design requirements, the control signals may also define parameters of the etching process, such as laser power, speed, and etching depth.

[0066] At position 1030, the laser source of the laser etching system is activated, and the laser source generates and emits a laser beam. The guiding system of the laser etching system guides the laser beam toward the area to be etched on the surface of the bottle. The 3D galvanometer system of the guiding system adjusts the optical path of the laser beam along the X and Y axes. In some embodiments, the 3D galvanometer system employs an X-axis galvanometer scanner and a Y-axis galvanometer scanner to adjust the path of the laser beam.

[0067] At 1040, during the etching process, the guiding system adjusts the focus of the laser beam to fit the bottle's dimensional profile or curvature. In some embodiments, a Z-axis adjustment system, including a Z-axis lens (or a set of Z-axis lenses) within a 3D galvanometer system, adjusts the focus of the laser beam to compensate for any curvature or irregularities on the bottle surface. The focal range of the laser beam relative to the bottle along the Z-axis direction (e.g., the incident direction of the laser beam) can be controlled within ±4.0 mm to ±4.9 mm. The drive module of the control system can process control signals to drive the X-axis galvanometer scanner, the Y-axis galvanometer scanner, and the Z-axis adjustment system, thereby dynamically adjusting the optical path of the laser beam and dynamically adjusting the position of the laser beam's focus within the focal range. The laser beam undergoes dynamic focusing on the Z-axis and reflections along the X and Y axes to position the laser beam's focus at a predetermined location on the desired pattern on the bottle surface. The desired pattern may span a curved area of ​​the bottle's surface around the bottle's central axis or longitudinal axis. Desired patterns (e.g., logos, images, text, etc.) are formed on bottles with high precision and consistency through laser etching.

[0068] At 1050, once the etching process is complete, the control system signals the holding system to release the bottle.

[0069] Finally, it should be explained that the above embodiments of this disclosure are for illustrative purposes only and are not intended to limit the scope of this disclosure. Although this disclosure has been explained in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in each of the above embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this disclosure should be included within the scope of protection of this disclosure.

Claims

1. A laser etching system for etching bottles, the laser etching system comprising: A laser source configured to generate and emit a laser beam; A holding system configured to obtain the bottle before etching and hold the bottle in a fixed position during etching; A control system configured to generate a set of control signals based on a three-dimensional (3D) model of the bottle, the control signals including a predetermined position of the pattern to be formed on the surface of the bottle; as well as A guiding system, comprising a 3D galvanometer system configured to dynamically adjust the focus of the laser beam according to the control signal and position the focus of the laser beam at the predetermined position to etch the surface and form the pattern.

2. The laser etching system as described in claim 1, wherein, The surface of the bottle has curvature around the longitudinal axis of the bottle, and the 3D galvanometer system is configured to adjust the focus of the laser beam within the focal range along the incident direction of the laser beam relative to the bottle.

3. The laser etching system as described in claim 1, wherein, The 3D galvanometer system includes an X-axis galvanometer scanner, a Y-axis galvanometer scanner, and a Z-axis adjustment system. The X-axis galvanometer scanner and the Y-axis galvanometer scanner are configured to adjust the optical path of the laser beam, and the Z-axis adjustment system is configured to adjust the focus of the laser beam along the Z-axis.

4. The laser etching system as described in claim 3, wherein, The Z-axis adjustment system includes one or more Z-axis lenses configured to perform reciprocating linear motion in the Z-axis direction to adjust the focus of the laser beam.

5. The laser etching system as described in claim 4, wherein, When the diameter of the bottle is 60 mm, the etching width along the direction perpendicular to the longitudinal direction of the bottle is 45 mm to 50 mm.

6. The laser etching system as described in claim 4, wherein, When the diameter of the bottle is 60 mm, the focal point range is ± 4.0 mm to ± 4.9 mm.

7. The laser etching system as described in claim 1, wherein, The holding system is further configured as follows: The bottle is released after the etching is complete.

8. The laser etching system as described in claim 1, wherein, The bottle in question is a beverage bottle.

9. The laser etching system as described in claim 8, wherein, The bottle is a PET bottle or a beverage can.

10. The laser etching system as claimed in claim 1, wherein, The laser source is selected from UV lasers, fiber lasers, CO2 lasers, and picosecond lasers.

11. A method for etching a bottle, the method comprising: A laser beam is emitted from a laser source; The bottle is obtained using a holding system and held in a fixed position during etching; The control system generates a set of control signals based on a three-dimensional (3D) model of the bottle. These control signals include the predetermined positions on the surface of the bottle where the pattern to be formed will be located. The 3D galvanometer system of the guidance system dynamically adjusts the focus of the laser beam according to the control signal, and positions the focus of the laser beam at the predetermined position to etch the surface and form the pattern.

12. The method of claim 11, wherein, The surface of the bottle has curvature around the longitudinal axis of the bottle, and the focus is adjusted within the focal range along the incident direction of the laser beam relative to the bottle by the 3D galvanometer system.

13. The method of claim 11, wherein, Adjusting the focus of the laser beam further includes: The optical path of the laser beam is adjusted using the X-axis and Y-axis galvanometer scanners of the 3D galvanometer system; and The focus of the laser beam is adjusted using the Z-axis adjustment system.

14. The method of claim 13, wherein, Adjusting the focus further includes: One or more Z-axis lenses of the Z-axis adjustment system perform reciprocating linear motion in the Z-axis direction.

15. The method of claim 14, wherein, When the diameter of the bottle is 60 mm, the etching width along the direction perpendicular to the longitudinal direction of the bottle is 45 mm to 50 mm.

16. The method of claim 14, wherein, When the diameter of the bottle is 60 mm, the focal point range is ±4.0 mm to ±4.9 mm.

17. The method of claim 11, further comprising: After the etching is completed, the bottle is released by the holding system.

18. The method of claim 11, wherein, The bottle in question is a beverage bottle.

19. The method of claim 18, wherein, The bottle is a PET bottle or a beverage can.

20. The method of claim 11, wherein, The laser source is selected from UV lasers, fiber lasers, CO2 lasers, and picosecond lasers.

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