Optical lens and laser processing system

Abstract

The embodiment of the utility model provides an optical lens. The optical lens sequentially comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens in the laser incidence direction. The first lens is a meniscus lens, the convex surface direction is consistent with the laser incident direction, and the first lens has positive focal power; the second lens is a biconcave lens and has negative focal power; the third lens is a meniscus lens, the convex surface direction is consistent with the laser incident direction, and the third lens has positive focal power; the fourth lens is a meniscus lens, the convex surface direction is consistent with the laser incident direction, and the fourth lens has positive focal power; the fifth lens is a biconvex lens and has positive focal power; the sixth lens is a protection flat plate.

Description

Technical Field

[0001] This specification relates to the field of optics, and in particular to an optical lens and a laser processing system. Background Technology

[0002] Optical lenses play a crucial role in applications such as scanning marking and drilling. Ultraviolet (UV) lenses, due to their shorter wavelengths and higher energy, are particularly effective in drilling and edge trimming. However, UV lens design faces several technical challenges, such as severe chromatic aberration.

[0003] The 355nm ultraviolet laser F-theta lens is an optical element specifically designed for 355nm ultraviolet lasers. It is primarily used for marking, cutting, drilling, micro-machining, and surface treatment of various materials such as glass, LCD screens, textiles, thin ceramic sheets, semiconductor silicon wafers, IC chips, sapphire, or polymer films. The key characteristic of the F-theta lens is its ability to uniformly focus the incident laser beam onto a single plane while maintaining excellent linearity—that is, a linear relationship between the scanning angle and the displacement on the imaging plane. This is crucial for ensuring the consistency and precision of laser processing.

[0004] 355nm ultraviolet telecentric F-theta lenses require a flat field. Field curvature will cause the optimal working surface to bend, and astigmatism will cause inconsistent linewidths in the X and Y directions or cause the drilled hole to become elliptical. This makes them difficult to apply in laser micro-precision processing, laser drilling and other applications where flatness requirements are more stringent.

[0005] Therefore, there is a need for an optical lens that can effectively eliminate the adverse effects of field curvature and astigmatism. Utility Model Content

[0006] This specification provides one or more embodiments of an optical lens, comprising, in sequence along the laser incident direction, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens; the first lens is a meniscus lens, with its convex surface aligned with the laser incident direction, and has positive optical power; the second lens is a biconcave lens, and has negative optical power; the third lens is a meniscus lens, with its convex surface aligned with the laser incident direction, and has positive optical power; the fourth lens is a meniscus lens, with its convex surface aligned with the laser incident direction, and has positive optical power; the fifth lens is a biconvex lens, and has positive optical power; the sixth lens is a protective plate.

[0007] In some embodiments, the first radius of curvature of the first lens is in the range of (-90) to (-80) mm, the second radius of curvature of the first lens is in the range of (-40) to (-30) mm; the third radius of curvature of the second lens is in the range of (-30) to (-20) mm, the fourth radius of curvature of the second lens is in the range of 200 to 300 mm; the fifth radius of curvature of the third lens is in the range of (-105) to (-95) mm, the sixth radius of curvature of the third lens is in the range of (-60) to (-50) mm; the seventh radius of curvature of the fourth lens is in the range of (-800) to (-700) mm, the eighth radius of curvature of the fourth lens is in the range of (-60) to (-50) mm; the ninth radius of curvature of the fifth lens is in the range of 145 to 155 mm, and the tenth radius of curvature of the fifth lens is in the range of (-500) to (-450) mm.

[0008] In some embodiments, the center thickness of the first lens is in the range of 2 to 4 mm, the center thickness of the second lens is in the range of 3 to 4 mm, the center thickness of the third lens is in the range of 20 to 25 mm, the center thickness of the fourth lens is in the range of 15 to 20 mm, the center thickness of the fifth lens is in the range of 10 to 15 mm, and the center thickness of the sixth lens is in the range of 10 to 15 mm.

[0009] In some embodiments, the outer diameter of the first lens is in the range of 30-35 mm, the outer diameter of the second lens is in the range of 40-45 mm, the outer diameter of the third lens is in the range of 66-72 mm, the outer diameter of the fourth lens is in the range of 82-88 mm, the outer diameter of the fifth lens is in the range of 90-95 mm, and the outer diameter of the sixth lens is in the range of 90-95 mm.

[0010] In some embodiments, the ratio of the focal length of the first lens to the focal length of the optical lens is in the range of 1.2 to 1.3, the ratio of the focal length of the second lens to the focal length of the optical lens is in the range of (-0.4) to (-0.3), the ratio of the focal length of the third lens to the focal length of the optical lens is in the range of 2.0 to 2.1, the ratio of the focal length of the fourth lens to the focal length of the optical lens is in the range of 1.2 to 1.3, and the ratio of the focal length of the fifth lens to the focal length of the optical lens is in the range of 2.1 to 2.2.

[0011] In some embodiments, the ratio of the refractive index to the Abbe number of the first lens is in the range of 0.021 to 0.022, the ratio of the refractive index to the Abbe number of the second lens is in the range of 0.038 to 0.039, the ratio of the refractive index to the Abbe number of the third lens is in the range of 0.021 to 0.022, the ratio of the refractive index to the Abbe number of the fourth lens is in the range of 0.014 to 0.016, the ratio of the refractive index to the Abbe number of the fifth lens is in the range of 0.021 to 0.022, and the ratio of the refractive index to the Abbe number of the sixth lens is in the range of 0.021 to 0.022.

[0012] In some embodiments, the distance between the center of the first lens and the center of the second lens is in the range of 5 to 10 mm, the distance between the center of the second lens and the center of the third lens is in the range of 5 to 10 mm, the distance between the center of the third lens and the center of the fourth lens is in the range of 1 to 4 mm, the distance between the center of the fourth lens and the center of the fifth lens is in the range of 2 to 4 mm, and the distance between the center of the fifth lens and the center of the sixth lens is in the range of 10 to 15 mm.

[0013] In some embodiments, the maximum distortion of the optical lens is less than or equal to 0.7%, the modulation transfer function (MTF) of the optical lens is greater than or equal to 170@0.2, and the image-side telecentricity of the optical lens is less than 1°.

[0014] In some embodiments, the field curvature of the optical lens is less than or equal to 0.07 mm, the scanning angle of the optical lens is 18.6°, the scanning area of ​​the optical lens is 50 mm × 50 mm, the focal length of the optical lens is 110 mm, and the working distance of the optical lens is in the range of 145 to 150 mm.

[0015] This specification provides a laser processing system according to one or more embodiments, including a laser, a scanning galvanometer, and an optical lens for laser processing, wherein the optical lens is the optical lens described in any embodiment, and the center wavelength of the laser is 355 nm. Attached Figure Description

[0016] This specification will be further described by way of exemplary embodiments, which will be described in detail with reference to the accompanying drawings. These embodiments are not limiting; in these embodiments, the same reference numerals denote the same structures, wherein:

[0017] Figure 1 These are schematic diagrams of the optical lens structure shown in some embodiments of this specification;

[0018] Figure 2 This is a schematic diagram of the optical path of an optical lens according to some embodiments of this specification;

[0019] Figure 3 These are field curvature diagrams of optical lenses shown in some embodiments of this specification;

[0020] Figure 4 These are distortion analysis diagrams of optical lenses shown in some embodiments of this specification;

[0021] Figure 5 This is a field curvature MTF diagram of an optical lens according to some embodiments of this specification. Detailed Implementation

[0022] To more clearly illustrate the technical solutions of the embodiments in this specification, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are merely some examples or embodiments of this specification. For those skilled in the art, these drawings can be applied to other similar scenarios without creative effort. Unless obvious from the context or otherwise specified, the same reference numerals in the drawings represent the same structures or operations.

[0023] It should be understood that the terms “system,” “device,” “unit,” and / or “module” used herein are one way to distinguish different components, elements, parts, sections, or assemblies at different levels. However, if other terms can achieve the same purpose, they may be replaced by other expressions.

[0024] As indicated in this specification and claims, unless the context clearly indicates otherwise, the words "a," "an," "an," and / or "the" do not specifically refer to the singular and may also include the plural. Generally speaking, the terms "comprising" and "including" only indicate the inclusion of expressly identified steps and elements, which do not constitute an exclusive list, and the method or apparatus may also include other steps or elements.

[0025] Figure 1 This is a schematic diagram of the structure of an optical lens according to some embodiments of this specification.

[0026] This specification provides an optical lens through some embodiments. In some embodiments, such as Figure 1 As shown, along the laser incident direction, the optical lens sequentially includes a first lens 1, a second lens 2, a third lens 3, a fourth lens 4, a fifth lens 5, and a sixth lens 6.

[0027] In some embodiments, the first lens 1 is a meniscus lens. In some embodiments, along the laser incident direction, the side of the first lens 1 closest to the second lens 2 is a convex surface, the direction of which is consistent with the laser incident direction, that is, the convex surface protrudes towards the laser incident direction; the other side is a concave surface, the concave surface being recessed towards the interior of the first lens 1.

[0028] Optical power is a physical quantity that describes the ability of a lens or optical system to converge or diverge light rays. Optical power characterizes the refractive power of a lens or optical system for an incident parallel beam of light; the higher the optical power value, the more strongly the parallel beam is refracted. When the optical power is greater than 0, it indicates that the incident parallel beam converges upon exiting; when the optical power is less than 0, it indicates that the incident parallel beam diverges upon exiting; when the optical power is equal to 0, it indicates that the incident parallel beam remains parallel upon exiting.

[0029] In some embodiments, the first lens 1 has positive optical power, that is, the optical power of the first lens 1 is greater than 0, which means that the parallel light beam incident on the first lens 1 converges when exiting the first lens 1.

[0030] By setting the first lens as a meniscus lens, its convex surface has a converging effect, which can initially reduce the aperture of the incident beam. By setting the first lens to have positive optical power, the converging effect is further enhanced, which helps to control the beam size in the subsequent optical path.

[0031] In some embodiments, the second lens 2 is a biconcave lens, with its center thickness being less than its edge thickness. In some embodiments, both surfaces of the second lens 2 are concave, meaning both surfaces of the second lens 2 are recessed towards the interior of the second lens 2.

[0032] In some embodiments, the second lens 2 has a negative optical power, that is, the optical power of the second lens 2 is less than 0, which means that the parallel light beam incident on the second lens 2 diverges when exiting the second lens 2.

[0033] By setting the second lens to have a negative optical power, thus enabling it to diverge, the range of light entering the lens can be increased. Using a second lens with a negative optical power after a first lens with a positive optical power helps with chromatic aberration correction, especially in the ultraviolet band, where the correction effect is particularly good.

[0034] In some embodiments, the third lens 3 is a meniscus lens, with the side closest to the fourth lens 4 being convex, the direction of which is consistent with the laser incident direction, and the third lens 3 has positive optical power. The characteristics of the third lens 3 are similar to those of the first lens 1, and will not be described again.

[0035] The converging effect of the third lens allows for further control of the output beam's aperture; the third lens, together with the first and second lenses, forms a positive optical power-negative optical power-positive optical power structure, which is beneficial for beam shaping.

[0036] In some embodiments, the fourth lens 4 is a meniscus lens, with the side closest to the fifth lens 5 being convex, the direction of which is consistent with the laser incident direction. The fourth lens 4 has positive optical power. The characteristics of the fourth lens 4 are similar to those of the first lens 1, and will not be described again.

[0037] The third and fourth lenses are both lenses with positive optical power, which can further converge light rays and make the light entering subsequent lenses smoother. The combination of multiple lenses with positive optical power is beneficial for reducing the beam aperture.

[0038] In some embodiments, the fifth lens 5 is a biconvex lens, with its center thickness greater than its edge thickness. In some embodiments, both surfaces of the fifth lens 5 are convex, meaning that both surfaces of the fifth lens 5 bulge outwards.

[0039] In some embodiments, the fifth lens 5 has positive optical power, that is, the optical power of the fifth lens 5 is greater than 0, which means that the parallel light beam incident on the fifth lens 5 converges when exiting the fifth lens 5.

[0040] By setting the fifth lens as a biconvex lens, a strong converging effect can be provided, which helps in the final imaging. A fifth lens with positive optical power can further converge light rays, which is beneficial to improving the light-gathering ability of the edge field of view and enhancing the relative illumination of the edge field of view.

[0041] In some embodiments, the sixth lens 6 is a protective plate. In some embodiments, the sixth lens 6 can be a plane lens, that is, both sides of the sixth lens 6 are planes.

[0042] The sixth lens can serve as a sealed window to maintain the internal environment of the optical system. By incorporating a sixth lens, subsequent optical components or detectors can be protected from environmental contamination and mechanical damage. Furthermore, a planar lens can provide additional optical thickness without altering the optical path, facilitating fine-tuning of the focal length and image plane position.

[0043] In some embodiments, the lenses can be made of materials such as fused silica, calcium fluoride, magnesium fluoride, silicon, germanium, zinc selenide, and various optical colorless glasses. After the lenses are manufactured, they can be coated using a vacuum coating process as needed. For example, an anti-reflective coating can be deposited on the lens surface to reduce reflections, thereby reducing light energy loss and making the image clearer.

[0044] The radius of curvature is used to describe the degree of curvature of a curve. The radius of curvature is the reciprocal of the curvature.

[0045] In some embodiments, the first radius of curvature of the first lens 1 is in the range of (-90) to (-80) mm, and the second radius of curvature of the first lens 1 is in the range of (-40) to (-30) mm. In some embodiments, the first radius of curvature of the first lens 1 is in the range of (-88) to (-82) mm, and the second radius of curvature of the first lens 1 is in the range of (-40) to (-35) mm. In some embodiments, the first radius of curvature of the first lens 1 is in the range of (-85) to (-84) mm, and the second radius of curvature of the first lens 1 is in the range of (-38) to (-37) mm. In some embodiments, the first radius of curvature of the first lens 1 is in the range of (-84.91) to (-84.61) mm, and the second radius of curvature of the first lens 1 is in the range of (-38.01) to (-37.85) mm. In some embodiments, the first radius of curvature of the first lens 1 is (-84.81 ± 0.01) mm, and the second radius of curvature of the first lens 1 is (-37.98 ± 0.01) mm.

[0046] It should be understood that, in this specification, the two radii of curvature of the lens are the radius of curvature of the laser incident surface and the radius of curvature of the laser exit surface of the lens, respectively. For example, the first radius of curvature of the first lens 1 corresponds to the radius of curvature of the laser incident surface of the first lens 1, and the second radius of curvature corresponds to the radius of curvature of the laser exit surface of the first lens 1.

[0047] In some embodiments, the third radius of curvature of the second lens 2 is in the range of (-30) to (-20) mm, and the fourth radius of curvature of the second lens 2 is in the range of 200 to 300 mm. In some embodiments, the third radius of curvature of the second lens 2 is in the range of (-30) to (-25) mm, and the fourth radius of curvature of the second lens 2 is in the range of 250 to 300 mm. In some embodiments, the third radius of curvature of the second lens 2 is in the range of (-29.10) to (-28.08) mm, and the fourth radius of curvature of the second lens 2 is in the range of 273.55 to 275.65 mm. In some embodiments, the third radius of curvature of the second lens 2 is (-28.59 ± 0.01) mm, and the fourth radius of curvature of the second lens 2 is 274.35 ± 0.03 mm. The third radius of curvature corresponds to the radius of curvature of the laser incident surface of the second lens 2 (i.e., the side closer to the first lens 1), and the fourth radius of curvature corresponds to the radius of curvature of the laser exit surface of the second lens 2 (i.e., the side farther away from the first lens 1).

[0048] In some embodiments, the fifth radius of curvature of the third lens 3 is in the range of (-105) to (-95) mm, and the sixth radius of curvature of the third lens 3 is in the range of (-60) to (-50) mm. In some embodiments, the fifth radius of curvature of the third lens 3 is in the range of (-101) to (-98) mm, and the sixth radius of curvature of the third lens 3 is in the range of (-56) to (-54) mm. In some embodiments, the fifth radius of curvature of the third lens 3 is in the range of (-99.99) to (-99.01) mm, and the sixth radius of curvature of the third lens 3 is in the range of (-55.99) to (-55.88) mm. In some embodiments, the fifth radius of curvature of the third lens 3 is (-99.35±0.01) mm, and the sixth radius of curvature of the third lens 3 is (-55.97±0.01) mm. The fifth radius of curvature corresponds to the radius of curvature of the laser incident surface of the third lens 3, and the sixth radius of curvature corresponds to the radius of curvature of the laser exit surface of the third lens 3.

[0049] In some embodiments, the seventh radius of curvature of the fourth lens 4 is in the range of (-800) to (-700) mm, and the eighth radius of curvature of the fourth lens 4 is in the range of (-60) to (-50) mm. In some embodiments, the seventh radius of curvature of the fourth lens 4 is in the range of (-780) to (-750) mm, and the eighth radius of curvature of the fourth lens 4 is in the range of (-59) to (-55) mm. In some embodiments, the seventh radius of curvature of the fourth lens 4 is in the range of (-769.00) to (-767.55) mm, and the eighth radius of curvature of the fourth lens 4 is in the range of (-57.55) to (-56.85) mm. In some embodiments, the seventh radius of curvature of the fourth lens 4 is (-768.57 ± 0.08) mm, and the eighth radius of curvature of the fourth lens 4 is (-57.11 ± 0.01) mm. Among them, the seventh radius of curvature corresponds to the radius of curvature of the laser incident surface of the fourth lens 4, and the eighth radius of curvature corresponds to the radius of curvature of the laser exit surface of the fourth lens 4.

[0050] In some embodiments, the ninth radius of curvature of the fifth lens 5 is in the range of 145–155 mm, and the tenth radius of curvature of the fifth lens 5 is in the range of (-500)–(-450) mm. In some embodiments, the ninth radius of curvature of the fifth lens 5 is in the range of 148–151 mm, and the tenth radius of curvature of the fifth lens 5 is in the range of (-490)–(-470) mm. In some embodiments, the ninth radius of curvature of the fifth lens 5 is in the range of 149.01–150.00 mm, and the tenth radius of curvature of the fifth lens 5 is in the range of (-483.99)–(-483.01) mm. In some embodiments, the ninth radius of curvature of the fifth lens 5 is 149.85 ± 0.05 mm, and the tenth radius of curvature of the fifth lens 5 is (-483.49 ± 0.07) mm. Among them, the ninth radius of curvature corresponds to the radius of curvature of the laser incident surface of the fifth lens 5 (i.e., the side closer to the fourth lens 4), and the tenth radius of curvature corresponds to the radius of curvature of the laser exit surface of the fifth lens 5 (i.e., the side farther away from the fourth lens 4).

[0051] By setting an appropriate radius of curvature, the focal length of each lens can be precisely controlled to meet the needs of different application scenarios, thereby reducing field curvature and distortion.

[0052] In some embodiments, the center thickness of the first lens 1 is in the range of 2-4 mm, the center thickness of the second lens 2 is in the range of 3-4 mm, the center thickness of the third lens 3 is in the range of 20-25 mm, the center thickness of the fourth lens 4 is in the range of 15-20 mm, the center thickness of the fifth lens 5 is in the range of 10-15 mm, and the center thickness of the sixth lens 6 is in the range of 10-15 mm. In some embodiments, the center thickness of the first lens 1 is in the range of 2.5-2.8 mm, the center thickness of the second lens 2 is in the range of 3.5-3.9 mm, the center thickness of the third lens 3 is in the range of 22-24 mm, the center thickness of the fourth lens 4 is in the range of 17-19 mm, the center thickness of the fifth lens 5 is in the range of 11-12 mm, and the center thickness of the sixth lens 6 is in the range of 11-12 mm. In some embodiments, the center thickness of the first lens 1 is in the range of 2.9–3.1 mm, the center thickness of the second lens 2 is in the range of 3.7–3.8 mm, the center thickness of the third lens 3 is in the range of 23.4–23.5 mm, the center thickness of the fourth lens 4 is in the range of 17.9–18.1 mm, the center thickness of the fifth lens 5 is in the range of 11.6–11.8 mm, and the center thickness of the sixth lens 6 is in the range of 11.3–11.4 mm. In some embodiments, the center thickness of the first lens 1 is in the range of 2.99–3.01 mm, the center thickness of the second lens 2 is in the range of 3.72–3.74 mm, the center thickness of the third lens 3 is in the range of 23.42–23.44 mm, the center thickness of the fourth lens 4 is in the range of 17.99–18.01 mm, the center thickness of the fifth lens 5 is in the range of 11.68–11.70 mm, and the center thickness of the sixth lens 6 is in the range of 11.32–11.34 mm. In some embodiments, the center thickness of the first lens 1 is 3±0.05mm, the center thickness of the second lens 2 is 3.73±0.01mm, the center thickness of the third lens 3 is 23.43±0.05mm, the center thickness of the fourth lens 4 is 18±0.05mm, the center thickness of the fifth lens 5 is 11.69±0.05mm, and the center thickness of the sixth lens 6 is 11.33±0.05mm.

[0053] Since different wavelengths of light refract at greater angles when passing through thicker materials, lenses with a larger center thickness usually produce greater chromatic aberration. By limiting the center thickness of the lens, each lens can be set to an appropriate thickness, thereby reducing dispersion.

[0054] In some embodiments, the outer diameter of the first lens 1 is in the range of 30-35 mm, the outer diameter of the second lens 2 is in the range of 40-45 mm, the outer diameter of the third lens 3 is in the range of 66-72 mm, the outer diameter of the fourth lens 4 is in the range of 82-88 mm, the outer diameter of the fifth lens 5 is in the range of 90-95 mm, and the outer diameter of the sixth lens 6 is in the range of 90-95 mm. In some embodiments, the outer diameter of the first lens 1 is in the range of 31-33 mm, the outer diameter of the second lens 2 is in the range of 41-43 mm, the outer diameter of the third lens 3 is in the range of 68-70 mm, the outer diameter of the fourth lens 4 is in the range of 84-86 mm, the outer diameter of the fifth lens 5 is in the range of 91-93 mm, and the outer diameter of the sixth lens 6 is in the range of 91-93 mm. In some embodiments, the outer diameter of the first lens 1 is 32 mm, the outer diameter of the second lens 2 is 42 mm, the outer diameter of the third lens 3 is 69 mm, the outer diameter of the fourth lens 4 is 85 mm, the outer diameter of the fifth lens 5 is 92 mm, and the outer diameter of the sixth lens 6 is 92 mm.

[0055] A larger outer diameter of a lens allows it to capture more light, thus improving system resolution and providing clearer image details. However, an excessively large outer diameter increases the lens's size. Therefore, by controlling the lens's outer diameter within the aforementioned suitable range, a balance can be struck between resolution and lens size.

[0056] In some embodiments, the focal length ratio of the first lens 1 to the optical lens is in the range of 1.2 to 1.3, the focal length ratio of the second lens 2 to the optical lens is in the range of (-0.4) to (-0.3), the focal length ratio of the third lens 3 to the optical lens is in the range of 2.0 to 2.1, the focal length ratio of the fourth lens 4 to the optical lens is in the range of 1.2 to 1.3, and the focal length ratio of the fifth lens 5 to the optical lens is in the range of 2.1 to 2.2. In some embodiments, the focal length ratio of the first lens 1 to the optical lens is 1.29, the focal length ratio of the second lens 2 to the optical lens is (-0.38), the focal length ratio of the third lens 3 to the optical lens is 2.08, the focal length ratio of the fourth lens 4 to the optical lens is 1.25, and the focal length ratio of the fifth lens 5 to the optical lens is 2.20.

[0057] In some embodiments, the focal length of the optical lens is in the range of 100-120mm, the focal length of the first lens 1 is in the range of 140-145mm, the focal length of the second lens 2 is in the range of (-45)-(-40)mm, the focal length of the third lens 3 is in the range of 225-230mm, the focal length of the fourth lens 4 is in the range of 135-140mm, and the focal length of the fifth lens 5 is in the range of 240-245mm. In some embodiments, the focal length of the optical lens is in the range of 105-115mm, the focal length of the first lens 1 is in the range of 140.98-141.98mm, the focal length of the second lens 2 is in the range of (-42.01)-(-41.01)mm, the focal length of the third lens 3 is in the range of 229.01-229.39mm, the focal length of the fourth lens 4 is in the range of 137.01-137.29mm, and the focal length of the fifth lens 5 is in the range of 241.65-241.75mm. In some embodiments, the focal length of the optical lens is 110mm, the focal length of the first lens 1 is 141.56mm, the focal length of the second lens 2 is (-41.34)mm, the focal length of the third lens 3 is 229.3mm, the focal length of the fourth lens 4 is 137.25mm, and the focal length of the fifth lens 5 is 241.7mm.

[0058] By setting the focal length of each lens within the aforementioned reasonable range, optical performance is guaranteed, resulting in an optical lens with low field curvature, low distortion, and high MTF performance. At the same time, the number of lenses is reduced, costs are lowered, and the size and weight of the equipment are reduced.

[0059] Chromatic aberration (dispersion) occurs because light of different wavelengths refracts at different angles when passing through a lens, causing different colors of light to focus at different positions. The Abbe number, also known as the dispersion coefficient, is used to measure the degree of light dispersion in a transparent medium.

[0060] Figure 2 This is a schematic diagram of the optical path of an optical lens according to some embodiments of this specification. In some embodiments, by limiting the ratio of the refractive index to the Abbe number of the optical lens, light of different wavelengths is focused onto the same plane as much as possible, such as... Figure 2 As shown, this reduces chromatic aberration; it not only helps reduce aberrations (such as spherical aberration, coma, astigmatism, etc.), but also improves the overall imaging quality and resolution of the system; it ensures that the focal plane of the entire optical system is more uniform, avoiding focus shift caused by chromatic aberration differences between different lenses, thereby improving the consistency and sharpness of the image.

[0061] In some embodiments, the ratio of the refractive index to the Abbe number of the first lens 1 is in the range of 0.021 to 0.022, the ratio of the refractive index to the Abbe number of the second lens 2 is in the range of 0.038 to 0.039, the ratio of the refractive index to the Abbe number of the third lens 3 is in the range of 0.021 to 0.022, the ratio of the refractive index to the Abbe number of the fourth lens 4 is in the range of 0.014 to 0.016, the ratio of the refractive index to the Abbe number of the fifth lens 5 is in the range of 0.021 to 0.022, and the ratio of the refractive index to the Abbe number of the sixth lens 6 is in the range of 0.021 to 0.022. In some embodiments, the ratio of the refractive index to the Abbe number of the first lens 1 is 1.45846 / 67.82, the ratio of the refractive index to the Abbe number of the second lens 2 is 1.58144 / 40.88, the ratio of the refractive index to the Abbe number of the third lens 3 is 1.45846 / 67.82, the ratio of the refractive index to the Abbe number of the fourth lens 4 is 1.43384 / 94.99, the ratio of the refractive index to the Abbe number of the fifth lens 5 is 1.45846 / 67.82, and the ratio of the refractive index to the Abbe number of the sixth lens 6 is 1.45846 / 67.82.

[0062] By limiting the ratio of refractive index to Abbe number within the aforementioned range, the design of optical systems can be simplified, the number and complexity of lenses can be reduced, thereby lowering costs and improving system reliability.

[0063] In some embodiments, the distance between the center of the first lens 1 and the center of the second lens 2 is in the range of 5-10 mm, the distance between the center of the second lens 2 and the center of the third lens 3 is in the range of 5-10 mm, the distance between the center of the third lens 3 and the center of the fourth lens 4 is in the range of 1-4 mm, the distance between the center of the fourth lens 4 and the center of the fifth lens 5 is in the range of 2-4 mm, and the distance between the center of the fifth lens 5 and the center of the sixth lens 6 is in the range of 10-15 mm. In some embodiments, the distance between the center of the first lens 1 and the center of the second lens 2 is in the range of 7-8 mm, the distance between the center of the second lens 2 and the center of the third lens 3 is in the range of 7-8 mm, the distance between the center of the third lens 3 and the center of the fourth lens 4 is in the range of 2-3 mm, the distance between the center of the fourth lens 4 and the center of the fifth lens 5 is in the range of 2.5-3.5 mm, and the distance between the center of the fifth lens 5 and the center of the sixth lens 6 is in the range of 13-14 mm. In some embodiments, the distance between the center of the first lens 1 and the center of the second lens 2 is in the range of 7.71–7.85 mm, the distance between the center of the second lens 2 and the center of the third lens 3 is in the range of 7.31–7.45 mm, the distance between the center of the third lens 3 and the center of the fourth lens 4 is in the range of 2.75–2.89 mm, the distance between the center of the fourth lens 4 and the center of the fifth lens 5 is in the range of 2.94–3.17 mm, and the distance between the center of the fifth lens 5 and the center of the sixth lens 6 is in the range of 13.71–13.85 mm. In some embodiments, the distance between the center of the first lens 1 and the center of the second lens 2 is 7.76 ± 0.05 mm, the distance between the center of the second lens 2 and the center of the third lens 3 is 7.37 ± 0.05 mm, the distance between the center of the third lens 3 and the center of the fourth lens 4 is 2.83 ± 0.05 mm, the distance between the center of the fourth lens 4 and the center of the fifth lens 5 is 3 ± 0.05 mm, and the distance between the center of the fifth lens 5 and the center of the sixth lens 6 is 13.78 ± 0.05 mm. It should be understood that the center of a lens refers to its optical center, meaning that the direction of light rays passing through this center (or optical center) remains unchanged.

[0064] The spacing between lenses affects the system's resolution. Excessive spacing can lead to longer light paths, increasing aberrations; while insufficient spacing can prevent light from converging properly, also affecting resolution. Some embodiments in this specification optimize lens spacing to maintain good contrast transmission at different spatial frequencies, thereby improving system resolution.

[0065] The spacing between lenses affects the contrast transmission capability of the system. Some embodiments in this specification ensure good contrast as light propagates between lenses by setting appropriate spacing between adjacent lenses, thus avoiding contrast loss due to excessive scattering or reflection.

[0066] Figure 3This is a field curvature diagram of an optical lens according to some embodiments of this specification, corresponding to F-theta distortion. The horizontal axis represents field curvature in millimeters; the vertical axis represents the scanning angle in degrees.

[0067] In some embodiments, such as Figure 3 As shown, the field curvature of the optical lens designed through the above embodiments is less than or equal to 0.07 mm, the scanning angle of the optical lens is 18.6°, the scanning area of ​​the optical lens is 50 mm × 50 mm, and the focal length of the optical lens is 110 mm. The scanning area is equal to the focal length of the optical lens multiplied by the tangent of its incident angle. In some embodiments, the working distance of the optical lens is in the range of 145–150 mm. The working distance refers to the distance between the side of the sixth lens 6 away from the fifth lens 5 and the focal point of the beam. In some embodiments, the working distance of the optical lens is 146.4 ± 0.5 mm.

[0068] The optical lenses of some embodiments in this specification achieve low field curvature, large scanning angle, and large scanning area.

[0069] Figure 4 This is a distortion analysis diagram of an optical lens according to some embodiments of this specification. The corresponding distortion type is F-theta distortion. The horizontal axis represents F-theta distortion in millimeters; the vertical axis represents the scanning angle in degrees.

[0070] In some embodiments, such as Figure 4 As shown, the maximum distortion of the optical lens designed according to the above embodiment is less than or equal to 0.7%, that is, the maximum F-theta relative distortion of the optical lens is less than or equal to 0.7%.

[0071] Figure 5 This is a field curvature MTF diagram of an optical lens according to some embodiments of this specification. The horizontal axis represents spatial frequency, which refers to the periodic variation of the light field within a given surface with spatial position, measured in periods / mm. The vertical axis represents the optical transfer function (OTF) magnitude, i.e., MTF. OTF is a transfer function used to express the image and phase transfer functions, with spatial frequency as the variable. MTF describes the response and resolution of the imaging system across the spatial frequency range.

[0072] In some embodiments, such as Figure 5 As shown, the modulation transfer function (MTF) of the optical lens designed according to the above embodiment is greater than or equal to 170@0.2.

[0073] The image-side telecentrism of the optical lens designed according to the above embodiments is less than 1°. Telecentrism is used to describe the angle by which the principal ray deviates from the optical axis. Object-side telecentrism is defined by the position of the incident pupil within the object side, and image-side telecentrism can be defined by the exit pupil located at infinity within the object side.

[0074] The optical lenses of some embodiments in this specification achieve low distortion, high MTF, and small image telecentricity.

[0075] Some embodiments of this specification provide a laser processing system, including a laser, a scanning galvanometer, and an optical lens for laser processing.

[0076] A laser is a device that emits laser light. Examples of lasers include gas lasers, solid-state lasers, semiconductor lasers, and dye lasers.

[0077] The scanning galvanometer is an optical path scanning device that can be applied to laser scanning, laser pattern display, etc.

[0078] The optical lens is any of the optical lenses described in the foregoing embodiments, and will not be described again.

[0079] In some embodiments, the center wavelength of the laser is 355 nm. The center wavelength refers to the center position of the wavelength distribution of the laser output.

[0080] The laser processing systems described in some embodiments of this specification employ the 355nm ultraviolet band, which has a short wavelength and high energy, and is widely used in applications such as scanning marking, drilling, and edge trimming. By using optical lenses with low field curvature, low distortion, and high MTF performance, the dispersion problem of ultraviolet lenses is effectively solved.

[0081] The basic concepts have been described above. Obviously, for those skilled in the art, the detailed disclosure above is merely illustrative and does not constitute a limitation of this specification. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements, and corrections to this specification. Such modifications, improvements, and corrections are suggested in this specification and therefore remain within the spirit and scope of the exemplary embodiments described herein.

[0082] Furthermore, this specification uses specific terms to describe embodiments thereof. For example, "an embodiment," "one embodiment," and / or "some embodiments" refer to a particular feature, structure, or characteristic associated with at least one embodiment of this specification. Therefore, it should be emphasized and noted that references to "an embodiment," "one embodiment," or "an alternative embodiment" in different locations throughout this specification do not necessarily refer to the same embodiment. Moreover, certain features, structures, or characteristics in one or more embodiments of this specification can be appropriately combined.

[0083] Furthermore, unless expressly stated in the claims, the order of processing elements and sequences, the use of numbers and letters, or other names described in this specification are not intended to limit the order of the processes and methods described herein. Although various examples have been discussed in the foregoing disclosure of embodiments that are currently considered useful, it should be understood that such details are for illustrative purposes only, and the appended claims are not limited to the disclosed embodiments; rather, the claims are intended to cover all modifications and equivalent combinations that conform to the substance and scope of the embodiments described herein. For example, while the system components described above can be implemented using hardware devices, they can also be implemented solely using software solutions, such as installing the described system on existing servers or mobile devices.

[0084] Similarly, it should be noted that, in order to simplify the descriptions disclosed herein and thus aid in the understanding of one or more embodiments, the foregoing description of embodiments in this specification sometimes combines multiple features into a single embodiment, drawing, or description thereof. However, this method of disclosure does not imply that the subject matter of this specification requires more features than those mentioned in the claims. In fact, the embodiments contain fewer features than all the features of the single embodiments disclosed above.

[0085] For each patent, patent application, patent application publication, and other material, such as articles, books, specifications, publications, and documents, referenced in this specification, the entire contents of which are incorporated herein by reference. This excludes historical application documents that are inconsistent with or conflict with the content of this specification, as well as documents that limit the broadest scope of the claims in this specification (currently or subsequently appended to this specification). It should be noted that in the event of any inconsistency or conflict between the descriptions, definitions, and / or terminology used in the supplementary materials to this specification and the content of this specification, the descriptions, definitions, and / or terminology used in this specification shall prevail.

[0086] Finally, it should be understood that the embodiments described in this specification are merely illustrative of the principles of the embodiments described herein. Other variations may also fall within the scope of this specification. Therefore, alternative configurations of the embodiments described herein are intended to be illustrative rather than limiting, and should be considered consistent with the teachings of this specification. Accordingly, the embodiments described herein are not limited to those explicitly introduced and described herein.

Claims

1. An optical lens characterized in that, The first lens, the second lens, the third lens, the fourth lens, the fifth lens and the sixth lens are arranged in sequence along the laser incidence direction; The first lens is a meniscus lens with the convex surface direction consistent with the laser incidence direction, and the first lens has positive focal power; The second lens is a double-concave lens, and the second lens has negative focal power; The third lens is a meniscus lens with the convex surface direction consistent with the laser incidence direction, and the third lens has positive focal power; The fourth lens is a meniscus lens with the convex surface direction consistent with the laser incidence direction, and the fourth lens has positive focal power; The fifth lens is a double-convex lens, and the fifth lens has positive focal power; The sixth lens is a protective flat plate.

2. The optical lens of claim 1, wherein, The first curvature radius of the first lens is in the range of (-90) to (-80) mm, and the second curvature radius of the first lens is in the range of (-40) to (-30) mm; The third curvature radius of the second lens is in the range of (-30) to (-20) mm, and the fourth curvature radius of the second lens is in the range of 200 to 300 mm; The fifth curvature radius of the third lens is in the range of (-105) to (-95) mm, and the sixth curvature radius of the third lens is in the range of (-60) to (-50) mm; The seventh curvature radius of the fourth lens is in the range of (-800) to (-700) mm, and the eighth curvature radius of the fourth lens is in the range of (-60) to (-50) mm; The ninth curvature radius of the fifth lens is in the range of 145 to 155 mm, and the tenth curvature radius of the fifth lens is in the range of (-500) to (-450) mm.

3. The optical lens of claim 1, wherein, The center thickness of the first lens is in the range of 2 to 4 mm, the center thickness of the second lens is in the range of 3 to 4 mm, the center thickness of the third lens is in the range of 20 to 25 mm, the center thickness of the fourth lens is in the range of 15 to 20 mm, the center thickness of the fifth lens is in the range of 10 to 15 mm, and the center thickness of the sixth lens is in the range of 10 to 15 mm.

4. The optical lens of claim 1, wherein, The outer diameter of the first lens is in the range of 30 to 35 mm, the outer diameter of the second lens is in the range of 40 to 45 mm, the outer diameter of the third lens is in the range of 66 to 72 mm, the outer diameter of the fourth lens is in the range of 82 to 88 mm, the outer diameter of the fifth lens is in the range of 90 to 95 mm, and the outer diameter of the sixth lens is in the range of 90 to 95 mm.

5. The optical lens of claim 1, wherein, The ratio of the focal length of the first lens to the focal length of the optical lens is in the range of 1.2 to 1.3, the ratio of the focal length of the second lens to the focal length of the optical lens is in the range of (-0.4) to (-0.3), the ratio of the focal length of the third lens to the focal length of the optical lens is in the range of 2.0 to 2.1, the ratio of the focal length of the fourth lens to the focal length of the optical lens is in the range of 1.2 to 1.3, and the ratio of the focal length of the fifth lens to the focal length of the optical lens is in the range of 2.1 to 2.

2.

6. The optical lens of claim 1, wherein, The ratio of the refractive index and the Abbe number of the first lens is in the range of 0.021-0.022, the ratio of the refractive index and the Abbe number of the second lens is in the range of 0.038-0.039, the ratio of the refractive index and the Abbe number of the third lens is in the range of 0.021-0.022, the ratio of the refractive index and the Abbe number of the fourth lens is in the range of 0.014-0.016, the ratio of the refractive index and the Abbe number of the fifth lens is in the range of 0.021-0.022, and the ratio of the refractive index and the Abbe number of the sixth lens is in the range of 0.021-0.

022.

7. The optical lens of claim 1, wherein, The distance between the center of the first lens and the center of the second lens is in the range of 5-10mm, the distance between the center of the second lens and the center of the third lens is in the range of 5-10mm, the distance between the center of the third lens and the center of the fourth lens is in the range of 1-4mm, the distance between the center of the fourth lens and the center of the fifth lens is in the range of 2-4mm, and the distance between the center of the fifth lens and the center of the sixth lens is in the range of 10-15mm.

8. The optical lens of any of claims 1-7, wherein, The maximum distortion of the optical lens is less than or equal to 0.7%, the modulation transfer function (MTF) of the optical lens is greater than or equal to 170@0.2, and the image-side telecentricity of the optical lens is less than 1°.

9. The optical lens of any of claims 1-7, wherein, The field curvature of the optical lens is less than or equal to 0.07mm, the scan angle of the optical lens is 18.6°, the scan field of the optical lens is 50mm×50mm, the focal length of the optical lens is 110mm, and the working distance of the optical lens is in the range of 145-150mm.

10. A laser processing system characterized by comprising: The optical lens comprises a laser, a scan galvanometer and an optical lens for laser processing, the optical lens is the optical lens according to any one of claims 1-9, and the central wavelength of the laser is 355nm.

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