355nm F-theta Ultraviolet Field Lens Optical Path Structure Device

Abstract

The present invention provides a 355nm F-theta ultraviolet field lens optical path construction device, comprising: a first lens component, a second lens component, a third lens component, a fourth lens component, an incident aperture, and a focal plane; the first lens component is a convex-concave lens convex towards the focal plane; the second lens component is a meniscus convex-concave lens convex towards the focal plane; the third lens component is a meniscus convex-concave lens convex towards the focal plane; the fourth lens component is a meniscus convex-concave lens convex towards the laser incident direction; the incident aperture, the first lens component, the second lens component, the third lens component, and the fourth lens component are sequentially arranged in the 355nm F-theta ultraviolet field lens optical path construction device. Through a reasonable optical path configuration, the present invention achieves large field of view and high-quality scanning while effectively ensuring the diameter of the incident light beam.

Description

Technical Field

[0001] The present invention relates to the field of laser processing such as laser marking and etching. Specifically, it relates to a 355nm F-theta ultraviolet field lens optical path construction device. Background Art

[0002] Due to the small thermal effect, 355nm ultraviolet laser shows great advantages in the fields of marking and etching of some special materials such as silicon wafers, thin ceramic sheets, textiles, and polymer films. The design of the ultraviolet field lens is greatly affected by the transmission efficiency of optical materials. It is difficult to design a field lens with a large beam diameter, a large scanning field of view, and low F-theta distortion.

[0003] The existing F-theta ultraviolet field lens optical paths mostly adopt a (-+++) four-lens component configuration. After retrieval, the patent documents CN101236291 A and CN105527706 A respectively disclose representative optical path configurations. For the first lens component in the beam incident direction, a double concave lens component is mostly used, and the fourth lens component is a double convex or plano-convex lens component. In this optical path configuration, the divergence angle of the beam is relatively large after passing through the first lens component, and the focal length of the fourth lens component is relatively short, which is not conducive to the control of field curvature and aberration. The patent document CN207181801 U discloses a (-++) three-lens component configuration, a 355nm ultraviolet field lens with a convex-concave lens component as the first lens component in the beam incident direction. However, due to the use of only three lens components, its aberration is relatively large. Therefore, a flat protective glass is used for further aberration correction. The aberration and F-theta distortion of this configuration are still difficult to be ideally controlled. The Nd / Vd = 1.52 / 1.64 flat glass used in the implementation has problems such as strong light absorption and poor thermal stability. Summary of the Invention

[0004] Aiming at the defects in the prior art, the purpose of the present invention is to provide a 355nm F-theta ultraviolet field lens optical path construction device.

[0005] A 355nm F-theta ultraviolet field lens optical path construction device according to the present invention includes: a first lens component, a second lens component, a third lens component, a fourth lens component, an incident aperture, and a focal plane; the first lens component adopts a convex-concave lens convex towards the focal plane; the second lens component adopts a meniscus convex-concave lens convex towards the focal plane; the third lens component adopts a meniscus convex-concave lens convex towards the focal plane; the fourth lens component adopts a meniscus convex-concave lens convex towards the laser incident direction; the incident aperture, the first lens component, the second lens component, the third lens component, and the fourth lens component are sequentially arranged in the 355nm F-theta ultraviolet field lens optical path construction device.

[0006] Preferably, it further includes: a focal plane;

[0007] The focal plane is disposed behind the fourth lens component.

[0008] Preferably, the value of the ratio f1 / f of the focal length f1 of the first lens component to the focal length f of the scanning field lens is as follows:

[0009] -0.41 ≤ f1 / f ≤ -0.28;

[0010] Preferably, the value of the refractive index Nd1 of the first material is as follows:

[0011] 1.45 ≤ Nd1 ≤ 1.51;

[0012] Preferably, the value of the first Abbe number Vd1 is as follows:

[0013] 54 ≤ Vd1 ≤ 70.

[0014] Preferably, the value of the ratio f2 / f of the optical power f2 of the second lens component to the focal length f of the scanning field lens is as follows:

[0015] 0.85 ≤ f2 / f ≤ 1.2;

[0016] The value of the refractive index Nd2 of the second material is as follows:

[0017] 1.45 ≤ Nd2 ≤ 1.53;

[0018] The value of the second Abbe number Vd2 is as follows:

[0019] 54 ≤ Vd2 ≤ 70.

[0020] Preferably, the value of the ratio f3 / f of the optical power f3 of the third lens component to the focal length f of the scanning field lens is as follows:

[0021] 0.45 ≤ f3 / f ≤ 0.86.

[0022] The value of the refractive index Nd3 of the third material is as follows:

[0023] 1.45 ≤ Nd3 ≤ 1.53;

[0024] The value of the third Abbe number Vd3 is as follows:

[0025] 54 ≤ Vd3 ≤ 70.

[0026] Preferably, the value of the ratio f4 / f of the optical power f4 of the fourth lens component to the focal length f of the scanning field lens is as follows:

[0027] 1.72 ≤ f4 / f ≤ 3.45.

[0028] Preferably, the refractive index Nd4 of the fourth material has the following value:

[0029] 1.45 ≤ Nd4 ≤ 1.53;

[0030] The value of the fourth Abbe number Vd4 is as follows:

[0031] 1.45 ≤ Nd4 ≤ 1.53.

[0032] When the construction wavelength of the 355nm F-theta ultraviolet field lens optical path is 355nm and the construction focal length is 290mm, the maximum allowable value of the incident beam diameter is not less than 12mm, the scanning angle is not less than ±25 degrees, the scanning range is greater than 252mm, and the distance between the entrance aperture and the center of the first lens is 15mm - 55mm.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] 1. The 355nm F-theta ultraviolet field lens provided by the present invention realizes large field of view and high-quality scanning through a reasonable optical path configuration while effectively ensuring the incident beam diameter.

[0035] 2. When the focal length of the present invention is 290mm, it allows the maximum beam diameter to exceed 12mm, the scanning angle is ±25 degrees, the scanning range is greater than 252mm, the F-theta distortion is less than 0.1%, and the spot size is close to the diffraction limit.

[0036] 3. The structure of the present invention is reasonable and convenient to use, and can overcome the defects of the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Other features, objects, and advantages of the present invention will become more apparent by reading the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0038] Figure 1 It is the optical path structure diagram of the 355nm F-theta ultraviolet field lens provided by the present invention.

[0039] Figure 2 It is the optical path modulation transfer function diagram of the 355nm F-theta ultraviolet field lens provided by the present invention.

[0040] Figure 3 It is the optical path simulation point spread function diagram of the 355nm F-theta ultraviolet field lens provided by the present invention.

[0041] Figure 4 It is the optical path field curvature and F-theta distortion diagram of the 355nm F-theta ultraviolet field lens provided by the present invention.

[0042] As shown in the figure:

[0043] Incident aperture 1, Third lens component 4

[0044] First lens component 2, Fourth lens component 5

[0045] Second lens component 3, Focusing plane 6 Detailed implementation mode

[0046] The present invention will be described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several changes and improvements can still be made. These all belong to the protection scope of the present invention.

[0047] A 355nm F-theta ultraviolet field lens optical path structure is as follows:

[0048] The 355nm F-theta ultraviolet field lens is characterized in that the designed wavelength is 355nm, the designed focal length is 290mm, the designed value of the incident beam diameter is 12mm, the designed scanning angle is ±25 degrees, and the distance between the incident aperture (galvanometer position) and the center of the first lens is 15mm - 55mm.

[0049] In the 355nm F-theta ultraviolet field lens optical path, the first lens component (2) is a convex-concave lens component convex towards the focusing plane, the second lens component (3) and the third lens component (4) are meniscus convex-concave lens components convex towards the focusing plane, and the fourth lens component (5) is a meniscus convex-concave lens component convex towards the laser incident direction

[0050] The ratio f1 / f of the focal length f1 of the first lens component (2) to the focal length f of the scanning field lens, the material refractive index Nd1, and the Abbe number Vd1 are as follows:

[0051] -0.41 ≤ f1 / f ≤ -0.28, 1.45 ≤ Nd1 ≤ 1.51, 54 ≤ Vd1 ≤ 70;

[0052] The ratio f2 / f of the optical power f2 of the second lens component (3) to the focal length f of the scanning field lens, the material refractive index Nd2, and the Abbe number Vd2 are as follows:

[0053] 0.85 ≤ f2 / f ≤ 1.2, 1.45 ≤ Nd2 ≤ 1.53, 54 ≤ Vd2 ≤ 70;

[0054] The ratio f3 / f of the optical power f3 of the third lens component (4) to the focal length f of the scanning field lens, the material refractive index Nd3, and the Abbe number Vd3 are as follows:

[0055] 0.45 ≤ f3 / f ≤ 0.86, 1.45 ≤ Nd3 ≤ 1.53, 54 ≤ Vd3 ≤ 70;

[0056] The ratio f4 / f of the optical power f4 of the fourth lens component (5) to the focal length f of the scanning field lens, the refractive index Nd4 of the material, and the Abbe number Vd4 satisfy:

[0057] 1.72 ≤ f4 / f ≤ 3.45, 1.45 ≤ Nd4 ≤ 1.53, 54 ≤ Vd4 ≤ 70;

[0058] For each lens component provided by the present invention, that is, the surface curvature radius R, thickness T, refractive index Nd of the material, and Abbe number Vd of each lens component in the lens component assembly are shown in the following table:

[0059]

[0060] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present application.

[0061] The specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present invention. Without conflict, the embodiments of the present application and the features in the embodiments can be combined arbitrarily with each other.

Claims

1. A 355nm F-theta ultraviolet field lens optical path construction device, Characterized in that, Comprising: A first lens component, a second lens component, a third lens component, a fourth lens component, an incident aperture, and a focal plane; The number of the lens components is 4; The first lens component is a convex-concave lens convex towards the focal plane; The second lens component is a meniscus convex-concave lens convex towards the focal plane; The third lens component is a meniscus convex-concave lens convex towards the focal plane; The fourth lens component is a meniscus convex-concave lens convex towards the laser incident direction; The incident aperture, the first lens component, the second lens component, the third lens component, and the fourth lens component are sequentially arranged in the 355nm F-theta ultraviolet field lens optical path construction device; The value of the ratio f1 / f of the focal length f1 of the first lens component to the focal length f of the field lens is as follows: -0.41 ≤ f1 / f ≤ -0.28; The value of the ratio f2 / f of the focal length f2 of the second lens component to the focal length f of the field lens is as follows: 0.85 ≤ f2 / f ≤ 1.2; The value of the ratio f3 / f of the focal length f3 of the third lens component to the focal length f of the field lens is as follows: 0.45 ≤ f3 / f ≤ 0.86; The value of the ratio f4 / f of the focal length f4 of the fourth lens component to the focal length f of the field lens is as follows: 1.72 ≤ f4 / f ≤ 3.

45.

2. The 355nm F-theta ultraviolet field lens optical path construction device according to claim 1, Characterized in that, The value of the refractive index Nd1 of the material of the first lens component is as follows: 1.45 ≤ Nd1 ≤ 1.

51.

3. The 355nm F-theta ultraviolet field lens optical path construction device according to claim 2, Characterized in that, The value of the Abbe number Vd1 of the first lens component is as follows: 54 ≤ Vd1 ≤ 70.

4. The 355nm F-theta ultraviolet field lens optical path construction device according to claim 1, Characterized in that, The value of the refractive index Nd2 of the material of the second lens component is as follows: 1.45 ≤ Nd2 ≤ 1.53; The value of the Abbe number Vd2 of the second lens component is as follows: 54 ≤ Vd2 ≤ 70.

5. The 355nm F-theta ultraviolet field lens optical path construction device according to claim 1, Characterized in that, The value of the refractive index Nd3 of the material of the third lens component is as follows: 1.45 ≤ Nd3 ≤ 1.53; The value of the Abbe number Vd3 of the third lens component is as follows: 54 ≤ Vd3 ≤ 70.

6. The 355nm F-theta ultraviolet field lens optical path construction device according to claim 1, Characterized in that, The value of the refractive index Nd4 of the material of the fourth lens component is as follows: 1.45 ≤ Nd4 ≤ 1.53; The value of the Abbe number Vd4 of the fourth lens component is as follows: 54 ≤ Vd4 ≤ 70.

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