WO2018218605A1

WO2018218605A1 - Laser cleaning lens

Info

Publication number: WO2018218605A1
Application number: PCT/CN2017/086840
Authority: WO
Inventors: 李家英; 孙博; 陈根余; 陈焱; 高云峰
Original assignee: 大族激光科技产业集团股份有限公司
Priority date: 2017-06-01
Filing date: 2017-06-01
Publication date: 2018-12-06
Also published as: CN110198794B; CN110198794A

Abstract

A laser cleaning lens comprises a first lens (100), a second lens (200), a third lens (300) and a fourth lens (400) sequentially arranged from the object side to the image side. The first lens (100) is a meniscus lens, the second lens (200) is a meniscus lens, the third lens (300) is a meniscus lens, and the fourth lens (400) is a plane-concave lens. The fourth lens (400) can move towards or away from the third lens (300).

Description

Laser cleaning lens

Technical field

The invention relates to a laser cleaning lens.

Background technique

Laser cleaning has the characteristics of no grinding, non-contact, no heat, etc. It is increasingly used in industrial cleaning. During cleaning, the spot formed by the laser cleaning lens on the surface of the workpiece is elongated, and the length of the spot is related to the focal length of the laser cleaning lens. Generally, the focal length of the laser cleaning lens is a certain value. For different cleaning ranges, that is, different spot lengths, it is necessary to use a laser cleaning lens with different focal lengths. Preparing a variety of laser cleaning lenses is not only cumbersome, but also increases the production cost of the laser cleaning lens.

Summary of the invention

Based on this, it is necessary to provide a laser cleaning lens with adjustable focal length.

A laser cleaning lens comprising a first lens, a second lens, a third lens and a fourth lens arranged in sequence from the object side to the image side, the first lens being a meniscus lens and the second lens being a curved lens The moon lens, the third lens is a meniscus lens, and the fourth lens is a plano-concave lens, and the fourth lens is movable toward or away from the third lens.

In the above laser cleaning lens, the fourth lens can be moved toward or away from the third lens, that is, the distance between the third lens and the fourth lens is adjustable, so that the focal length of the laser cleaning lens can be changed. Correspondingly, the length of the spot formed by the laser cleaning lens on the surface of the workpiece will also vary with the focal length. And change. Therefore, the above laser cleaning lens can meet the requirements of different cleaning ranges, and is very convenient, and can also reduce the production cost of the laser cleaning lens.

DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the description of the prior art will be briefly described below. Obviously, the drawings in the following description are only It is a certain embodiment of the present invention, and those skilled in the art can obtain drawings of other embodiments according to the drawings without any creative work.

1 is a schematic structural view of a laser cleaning lens according to an embodiment;

2 is a geometric aberration diagram of the laser cleaning lens shown in FIG. 1;

3 is a graph showing an optical transfer function of the laser cleaning lens shown in FIG. 1.

detailed description

In order to facilitate the understanding of the present invention, a laser cleaning lens will be described more fully hereinafter with reference to the accompanying drawings. A preferred embodiment of a laser cleaning lens is given in the drawings. However, the laser cleaning lens can be implemented in many different forms and is not limited to the embodiments described herein. Rather, the purpose of providing these embodiments is to make the disclosure of the laser cleaning lens more thorough and comprehensive.

All technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs, unless otherwise defined. The terminology used herein in the specification of the laser cleaning lens is for the purpose of describing the specific embodiments and is not intended to limit the invention. The term "and/or" used herein includes any and all combinations of one or more of the associated listed items.

1 is a schematic structural view of a laser cleaning lens according to an embodiment, for convenience of explanation, only The part related to the present embodiment has been made.

As shown in FIG. 1, a laser cleaning lens according to an embodiment includes a first lens 100, a second lens 200, a third lens 300, and a fourth lens which are sequentially arranged from the object side toward the image side (the direction of the arrow in FIG. 1). 400 and fifth lens 500. The first lens 100 is a meniscus lens, the second lens 200 is a meniscus lens, the third lens 300 is a meniscus lens, the fourth lens 400 is a plano-concave lens, and the fifth lens 500 is a planar lens. The first lens 100, the second lens 200, the third lens 300, and the fourth lens 400 are mainly used for focusing, and the fifth lens 500 is protected from debris splashing or contamination during the cleaning process. In the fourth lens 400, in other embodiments, the fifth lens 500 may be omitted.

In the present embodiment, the fourth lens 400 is movable toward or away from the third lens 300. That is, the distance between the third lens 300 and the fourth lens 400 is adjustable, so that the focal length of the laser cleaning lens can be changed. Accordingly, the length of the spot formed by the laser cleaning lens on the surface of the workpiece also varies with the focal length. Variety. Therefore, the above laser cleaning lens can meet the requirements of different cleaning ranges, and is very convenient, and can also reduce the production cost of the laser cleaning lens.

In the laser cleaning lens, as shown in FIG. 1, the infrared ray having a wavelength of 1064 nm is propagated from left to right, and the workpiece is located on the right side of the fifth lens 500. Taking the intersection of the spherical surface and the optical axis 600 as the standard, the spherical center of the spherical surface is left at the intersection point, the radius of curvature of the spherical surface is negative, and the spherical center of the sphere is right at the intersection point, and the radius of curvature of the spherical surface is positive. That is, the positive and negative of the radius of curvature are irrelevant and represent only the direction of curvature of the spherical surface.

The first lens 100 includes a first face 110 and a second face 120 that are arranged from the object side toward the image side direction. The first face 110 protrudes to the right and has a radius of curvature of -15 mm to -55 mm. The second face 120 is convex toward the right and has a radius of curvature of -16 mm to -45 mm. The center thickness of the first lens 100 (i.e., the thickness of the first lens 100 on the optical axis 600) is 4.8 mm to 10.2 mm. The refractive index of the first lens 100 and Abbe The ratio of the number is 1.46/67.

The second lens 200 includes a third surface 210 and a fourth surface 220 which are arranged from the object side toward the image side direction. The third face 210 protrudes to the right and has a radius of curvature of -95 mm to -200 mm. The fourth face 220 protrudes to the right, the radius of curvature is less than or equal to the radius of curvature of the third face 210, and the radius of curvature of the fourth face 220 is -50 mm to -95 mm. The center thickness of the second lens 200 is 5.2 mm to 10 mm. The ratio of the refractive index of the second lens 200 to the Abbe number is 1.80/25.

The third lens 300 includes a fifth surface 310 and a sixth surface 320 which are arranged from the object side toward the image side direction. The fifth side 310 protrudes to the right and has a radius of curvature of -202 mm to -283 mm. The sixth surface 320 protrudes to the right with a radius of curvature smaller than the radius of curvature of the fifth surface 310, and the sixth surface 320 has a radius of curvature of -101 mm to -133 mm. The center thickness of the third lens 300 is 3.3 mm to 9.6 mm. The ratio of the refractive index of the third lens 300 to the Abbe number is 1.80/25.

The fourth lens 400 includes a seventh surface 410 and an eighth surface 420 which are arranged from the object side toward the image side direction. The seventh side 410 protrudes to the right and has a radius of curvature of -64 mm to -104 mm. The eighth face 420 is a plane perpendicular to the optical axis 600, and the radius of curvature of the eighth face 420 is ∞. The center thickness of the fourth lens 400 is 0.5 mm to 5.5 mm. The ratio of the refractive index of the fourth lens 400 to the Abbe number is 1.50/62.

The fifth lens 500 includes a ninth surface 510 and a tenth surface 520 which are arranged from the object side toward the image side direction. The ninth face 510 is a plane having a radius of curvature of ∞. The tenth face 520 is a plane having a radius of curvature of ∞. The center thickness of the fifth lens 500 is 0.8 mm to 5.6 mm. The ratio of the refractive index of the fifth lens 500 to the Abbe number is 1.50/62.

In the present embodiment, the positions of the first lens 100, the second lens 200, and the third lens 300 are fixed, and the distance between the second surface 120 and the third surface 210 (refers to the second surface 120 and the optical axis 600) The distance between the intersection of the third surface 210 and the optical axis 600, the same applies hereinafter, is 0.3 mm to 4 mm, and the distance between the fourth surface 220 and the fifth surface 310 is 0.1 mm to 2.2 mm. Fourth lens 400 shift The distance between the sixth surface 320 and the seventh surface 410 can vary from 7 mm to 46 mm.

The laser cleaning lens of the present embodiment is an f-θ lens, and the size of the entrance pupil is 10 mm. When the fourth lens 400 is moved such that the pitch of the sixth surface 320 and the seventh surface 410 is varied within a range of 7 mm to 46 mm, the focal length of the laser cleaning lens may vary from 160 mm to 254 mm, and the working distance may be 98 mm to Within the range of 244 mm, the length of the spot varies from 144 mm to 220 mm. Therefore, the laser cleaning lens of the present embodiment can meet the requirements of different cleaning ranges.

Combined with Figure 2 and Figure 3, when the resolution reaches 20line/mm, the MTF of the laser cleaning lens is still greater than 0.3, which has achieved the desired effect. Whether it is geometric aberration or optical transfer function, the laser cleaning lens is ideally calibrated to ensure laser cleaning.

The technical features of the above-described embodiments may be arbitrarily combined. For the sake of brevity of description, all possible combinations of the technical features in the above embodiments are not described. However, as long as there is no contradiction between the combinations of these technical features, All should be considered as the scope of this manual.

The above-described embodiments are merely illustrative of several embodiments of the present invention, and the description thereof is more specific and detailed, but is not to be construed as limiting the scope of the invention. It should be noted that a number of variations and modifications may be made by those skilled in the art without departing from the spirit and scope of the invention. Therefore, the scope of the invention should be determined by the appended claims.

Claims

A laser cleaning lens comprising a first lens, a second lens, a third lens and a fourth lens arranged in sequence from the object side to the image side, the first lens being a meniscus lens and the second lens being a curved lens The moon lens, the third lens is a meniscus lens, and the fourth lens is a plano-concave lens, and the fourth lens is movable toward or away from the third lens.
A laser cleaning lens according to claim 1, wherein said first lens comprises a first face and a second face, said second lens comprises a third face and a fourth face, said third lens comprising a fifth surface and a sixth surface, wherein the fourth lens includes a seventh surface and an eighth surface, and the first surface to the eighth surface are sequentially arranged from the object side to the image side, and the sixth surface The spacing from the seventh face can vary from 7 mm to 46 mm.
The laser cleaning lens according to claim 2, wherein a distance between the second surface and the third surface is 0.3 mm to 4 mm, and a distance between the fourth surface and the fifth surface is 0.1 mm to 2.2. Mm.
The laser cleaning lens according to claim 2, wherein a radius of curvature of the third surface is greater than or equal to a radius of curvature of the fourth surface, and a radius of curvature of the fifth surface is greater than a curvature of the sixth surface radius.
The laser cleaning lens according to claim 2, wherein the first surface has a radius of curvature of -15 mm to -55 mm, and the second surface has a radius of curvature of -16 mm to -45 mm, the third surface The radius of curvature is -95 mm to -200 mm, the radius of curvature of the fourth face is -50 mm to -95 mm, the radius of curvature of the fifth face is -202 mm to -283 mm, and the radius of curvature of the sixth face is - 101mm to -133mm, the seventh surface has a radius of curvature of -64mm to -104mm, and the eighth surface has a radius of curvature of ∞.
The laser cleaning lens according to claim 1, wherein said first lens The center has a thickness of 4.8 mm to 10.2 mm, the second lens has a center thickness of 5.2 mm to 10 mm, the third lens has a center thickness of 3.3 mm to 9.6 mm, and the fourth lens has a center thickness of 0.5 mm to 5.5mm.
The laser cleaning lens according to claim 1, wherein a ratio of a refractive index to an Abbe number of the first lens is 1.46/67, and a ratio of a refractive index to an Abbe number of the second lens is 1.80. /25, the ratio of the refractive index to the Abbe number of the third lens is 1.80/25, and the ratio of the refractive index of the fourth lens to the Abbe number is 1.50/62.
The laser cleaning lens according to claim 1, further comprising a fifth lens, wherein the first lens to the fifth lens are sequentially arranged from the object side to the image side, the fifth lens a planar lens, the fifth lens includes a ninth surface and a tenth surface, the ninth surface is located between the fourth lens and the tenth surface, and a radius of curvature of the ninth surface is ∞, The radius of curvature of the tenth surface is ∞.
The laser cleaning lens according to claim 8, wherein the fifth lens has a center thickness of 0.8 mm to 5.6 mm.
The laser cleaning lens according to claim 8, wherein a ratio of a refractive index to an Abbe number of said fifth lens is 1.50/62.