CN213903934U - Telecentric laser field lens and laser scanning system thereof - Google Patents

Abstract

The utility model discloses a telecentric laser field lens and laser scanning system thereof, include first lens, second lens, third lens, fourth lens, fifth lens and the sixth lens that sets gradually along laser propagation direction, first lens is biconcave sphere negative lens, the second lens is the unsmooth sphere negative lens, the third lens is the positive lens of unsmooth sphere, the fourth lens is the positive lens of plano-convex sphere, the fifth lens is the positive lens of biconvex sphere, the sixth lens is biplane lens, can realize better flat field effect to make laser beam machining can stabilize the high efficiency and go on.

Description

Telecentric laser field lens and laser scanning system thereof

Technical Field

The utility model relates to an optical equipment field, in particular to telecentric laser field lens and laser scanning system thereof.

Background

In the process of modern industrial manufacturing, laser processing is widely applied to various processing technologies such as welding, surface treatment, punching, marking and the like because of the advantages of high precision, high efficiency and the like; the laser processing mainly comprises four parts, namely a laser, a power supply, an optical system and a mechanical system; the optical system generally comprises an X/Y galvanometer and a scanning field lens; the scanning field lens is generally arranged at the tail end of a laser system and used for forming a focusing plane, and the reflecting angle of the X/Y galvanometer is controlled, so that laser beams are focused on different areas of the focusing plane, and various processes such as marking, welding, laser cleaning, 3D printing and the like are realized; the scan field lens is generally divided into: a flat field lens and a telecentric field lens; the telecentric scanning field lens in the industry at present often has the defect of poor flat field effect, thereby influencing the stable and efficient operation of laser processing.

SUMMERY OF THE UTILITY MODEL

The utility model discloses aim at solving one of the technical problem that exists among the prior art at least. Therefore, the utility model provides a telecentric laser field lens can realize better flat field effect to make laser beam machining can stabilize the high efficiency and go on.

The utility model also provides a laser scanning system of having above-mentioned telecentric laser field lens.

According to the utility model discloses telecentric laser field lens of first aspect embodiment, include first lens, second lens, third lens, fourth lens, fifth lens and the sixth lens that sets gradually along laser propagation direction, first lens is biconcave sphere negative lens, the second lens is the unsmooth sphere negative lens, the third lens is the unsmooth sphere positive lens, the fourth lens is the plano-convex sphere positive lens, the fifth lens is the biconvex sphere positive lens, the sixth lens is biplanar lens.

According to the utility model discloses telecentric laser field lens has following beneficial effect at least: the laser instrument sends the laser of a bundle of fixed facula, after the reflection of X/Y galvanometer, enter into telecentric laser field lens, thereby laser passes through first lens in proper order, the second lens, the third lens, the fourth lens, fifth lens and sixth lens, through the many refractions of lens, make the exit pupil of camera lens at image space infinity, the chief ray of having realized the focused beam all perpendicular to focal plane under the condition of any angle of view, make telecentric laser field lens have better flat field effect, thereby make laser beam machining can go on steadily high-efficiently.

According to some embodiments of the present invention, the lens barrel further comprises a main barrel, wherein the first lens, the second lens, the third lens, the fourth lens, the fifth lens and the sixth lens are all disposed in the main barrel.

According to some embodiments of the present invention, the lens barrel further comprises a locking ring, and the first lens, the second lens, the third lens, the fourth lens, the fifth lens and the sixth lens are all fixed in the main barrel by the locking ring.

According to some embodiments of the present invention, a spacer is disposed between the first lens and the second lens, between the second lens and the third lens, between the third lens and the fourth lens, between the fourth lens and the fifth lens, and between the fifth lens and the sixth lens.

According to some embodiments of the invention, the sixth lens is provided with a rubber ring having a cushioning effect with respect to one side of the spacer.

According to some embodiments of the invention, the first lens comprises a first spherical surface and a second spherical surface, the first spherical surface having a radius of curvature of-110.16 ± 0.11016 mm, the second spherical surface having a radius of curvature of-234.29 ± 0.23429 mm; the second lens comprises a third spherical surface and a fourth spherical surface, the radius of curvature of the third spherical surface is-40.0 +/-0.04 mm, and the radius of curvature of the fourth spherical surface is 66.12 +/-0.06612 mm; the third lens comprises a fifth spherical surface and a sixth spherical surface, the radius of curvature of the fifth spherical surface is-247.7 +/-0.2477 mm, and the radius of curvature of the sixth spherical surface is 85.18 +/-0.08518 mm; the fourth lens comprises a first plane and a seventh spherical surface, and the radius of curvature of the seventh spherical surface is 134.75 +/-0.13475 millimeters; the fifth lens comprises an eighth spherical surface and a ninth spherical surface, the radius of curvature of the eighth spherical surface is 206.4 +/-0.2064 millimeters, and the radius of curvature of the ninth spherical surface is 438.76 +/-0.43876 millimeters; the sixth lens includes a second plane and a third plane.

According to some embodiments of the invention, the first lens has a center thickness of 6.0 ± 0.1 mm; the central thickness of the second lens is 16.0 +/-0.1 mm; the central thickness of the third lens is 15.0 +/-0.1 mm; the central thickness of the fourth lens is 16.0 +/-0.1 mm; the center thickness of the fifth lens is 17.0 +/-0.1 mm; the center thickness of the sixth lens is 5.0 +/-0.1 mm.

According to some embodiments of the invention, the air separation on the optical axis of the first lens and the second lens is 16.0 mm; the air space between the second lens and the third lens on the optical axis is 1.3 mm; the air space between the third lens and the fourth lens on the optical axis is 1.3 mm; the air space between the fourth lens and the fifth lens on the optical axis is 1.3 mm; an air space between the fifth lens and the sixth lens on the optical axis is 12.0 mm.

According to some embodiments of the present invention, the first lens, the second lens, the third lens, the fourth lens, the fifth lens and the sixth lens are made of quartz glass, a refractive index of the quartz glass is 1.45, and an abbe number of the quartz glass is 67.7.

According to the utility model discloses laser scanning system of second aspect embodiment, include according to the utility model discloses the telecentric laser field lens of above-mentioned first aspect embodiment.

According to the utility model discloses laser scanning system has following beneficial effect at least: the laser instrument sends the laser of a bundle of fixed facula, after the reflection of X/Y galvanometer, enter into telecentric laser field lens, thereby laser passes through first lens in proper order, the second lens, the third lens, the fourth lens, fifth lens and sixth lens, through the many refractions of lens, make the exit pupil of camera lens at image space infinity, the chief ray of having realized the focused beam all perpendicular to focal plane under the condition of any angle of view, make telecentric laser field lens have better flat field effect, thereby make laser beam machining can go on steadily high-efficiently.

Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

fig. 1 is a schematic view of an internal structure of a lens of a telecentric laser field lens according to an embodiment of the present invention;

figure 2 is an optical diagram of the entrance pupil of the embodiment of the present invention with a diameter of 14 mm;

figure 3 is an optical diagram of the embodiment of the present invention with an entrance pupil of 20 mm;

fig. 4 is a MTF graph of an entrance pupil of 14mm according to an embodiment of the present invention;

fig. 5 is a MTF graph of an entrance pupil of 20mm according to an embodiment of the present invention;

fig. 6 is a Though Focus MTF graph of an entrance pupil of 14mm according to an embodiment of the present invention;

fig. 7 is a Though Focus MTF plot of an entrance pupil of 20mm in accordance with an embodiment of the present invention;

fig. 8 is an optical speckle pattern with an entrance pupil of 14mm according to an embodiment of the present invention;

fig. 9 is an optical speckle pattern with an entrance pupil of 20mm according to an embodiment of the present invention;

fig. 10 is a graph of field curvature and distortion at an entrance pupil of 14mm according to an embodiment of the present invention;

fig. 11 is a graph of field curvature and distortion with an entrance pupil of 20mm according to an embodiment of the present invention;

fig. 12 is a relative illuminance diagram according to an embodiment of the present invention.

Reference numerals:

the lens comprises a first lens 100, a second lens 200, a third lens 300, a fourth lens 400, a fifth lens 500, a sixth lens 600, a main lens barrel 700, a lock ring 800, a spacer ring 900 and a rubber ring 1000.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are exemplary only for the purpose of explaining the present invention, and should not be construed as limiting the present invention.

In the description of the present invention, it should be understood that the orientation or positional relationship referred to in the description of the orientation, such as the upper and lower directions, is the orientation or positional relationship shown on the drawings, and is only for convenience of description and simplification of description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed in a specific orientation, and be operated, and therefore should not be construed as limiting the present invention.

In the description of the present invention, unless there is an explicit limitation, the words such as setting and connection should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meaning of the above words in the present invention by combining the specific contents of the technical solution.

Referring to fig. 1, the utility model discloses telecentric laser field lens of first aspect embodiment, include first lens 100, second lens 200, third lens 300, fourth lens 400, fifth lens 500 and the sixth lens 600 that set gradually along the laser propagation direction, first lens 100 is the negative lens of biconcave sphere, and second lens 200 is the negative lens of unsmooth sphere, and third lens 300 is the positive lens of unsmooth sphere, and fourth lens 400 is the positive lens of plano-convex sphere, and fifth lens 500 is the positive lens of biconvex sphere, and sixth lens 600 is the biplane lens. The laser instrument sends the laser of a bundle of fixed facula, after the reflection of X/Y galvanometer, enter into telecentric laser field lens, thereby laser passes through first lens 100 in proper order, second lens 200, third lens 300, fourth lens 400, fifth lens 500 and sixth lens 600, multiple refraction through lens, make the exit pupil of camera lens at image space infinity, realized that the chief ray of focused beam all is perpendicular to focal plane under the condition of any angle of view, make telecentric laser field lens have better flat field effect, thereby make laser beam machining can go on stably and efficiently.

Referring to fig. 1, in some embodiments of the present invention, the lens barrel further includes a main barrel 700, and the first lens 100, the second lens 200, the third lens 300, the fourth lens 400, the fifth lens 500, and the sixth lens 600 are disposed in the main barrel 700. The first lens 100, the second lens 200, the third lens 300, the fourth lens 400, the fifth lens 500 and the sixth lens 600 are all arranged in the main lens barrel 700 and are sequentially arranged according to the propagation direction of laser light, so that the laser light can be perpendicular to a focal plane after passing through the main lens barrel 700, a good flat field effect is generated, and uniform image quality reaching a diffraction limit in a scanning field range can be achieved.

Referring to fig. 1, in some embodiments of the present invention, a lock ring 800 is further included, and the first lens 100, the second lens 200, the third lens 300, the fourth lens 400, the fifth lens 500, and the sixth lens 600 are all fixed in the main barrel 700 by the lock ring 800. The first lens 100, the second lens 200, the third lens 300, the fourth lens 400, the fifth lens 500, and the sixth lens 600 are stably mounted and fixed in the main barrel 700 by the lock ring 800.

In some embodiments of the present invention, a spacer 900 is disposed between first lens 100 and second lens 200, between second lens 200 and third lens 300, between third lens 300 and fourth lens 400, between fourth lens 400 and fifth lens 500, and between fifth lens 500 and sixth lens 600. The spacer 900 is capable of preventing adjacent lenses from being crushed against each other to cause abrasion.

In some embodiments of the present invention, a rubber ring 1000 with a buffering function is disposed on one side of the sixth lens 600 opposite to the spacer 900. The rubber ring 1000 has a good buffering effect, reduces deformation of the sixth lens 600, and can also play a good sealing effect, thereby playing a good protection effect on the inside of the main barrel 700.

In some embodiments of the present invention, the first lens 100 includes a first spherical surface and a second spherical surface, the first spherical surface has a radius of curvature of-110.16 ± 0.11016 mm, and the second spherical surface has a radius of curvature of-234.29 ± 0.23429 mm; the second lens 200 comprises a third spherical surface and a fourth spherical surface, the radius of curvature of the third spherical surface is-40.0 +/-0.04 mm, and the radius of curvature of the fourth spherical surface is 66.12 +/-0.06612 mm; the third lens 300 comprises a fifth spherical surface and a sixth spherical surface, wherein the radius of curvature of the fifth spherical surface is-247.7 +/-0.2477 mm, and the radius of curvature of the sixth spherical surface is 85.18 +/-0.08518 mm; the fourth lens 400 includes a first plane and a seventh spherical surface having a radius of curvature of 134.75 ± 0.13475 mm; the fifth lens 500 comprises an eighth spherical surface and a ninth spherical surface, wherein the radius of curvature of the eighth spherical surface is 206.4 +/-0.2064 mm, and the radius of curvature of the ninth spherical surface is 438.76 +/-0.43876 mm; the sixth lens 600 includes a second plane and a third plane. Wherein, the positive numerical value represents a convex spherical surface, and the negative numerical value represents a concave spherical surface; the spherical or planar setting of the first lens 100, the second lens 200, the third lens 300, the fourth lens 400, the fifth lens 500, and the sixth lens 600 enables the lens group provided in the main barrel 700 to have a good field flattening effect.

In some embodiments of the present invention, the center thickness of the first lens 100 is 6.0 ± 0.1 mm; the center thickness of the second lens 200 is 16.0 +/-0.1 mm; the center thickness of the third lens 300 is 15.0 ± 0.1 mm; the center thickness of the fourth lens 400 is 16.0 ± 0.1 mm; the center thickness of the fifth lens 500 is 17.0 +/-0.1 mm; the center thickness of the sixth lens 600 is 5.0 ± 0.1 mm. The center thicknesses of the first lens 100, the second lens 200, the third lens 300, the fourth lens 400, the fifth lens 500 and the sixth lens 600 are set so that the telecentric laser field lens has good ordinary effects.

In some embodiments of the present invention, the air distance between the first lens 100 and the second lens 200 on the optical axis is 16.0 mm; the air space between the second lens 200 and the third lens 300 on the optical axis is 1.3 mm; the air space between the third lens 300 and the fourth lens 400 on the optical axis is 1.3 mm; the air space between the fourth lens 400 and the fifth lens 500 on the optical axis is 1.3 mm; the air space between the fifth lens 500 and the sixth lens 600 on the optical axis is 12.0 mm, so that the telecentric laser field lens has good ordinary effect.

In some embodiments of the present invention, the first lens 100, the second lens 200, the third lens 300, the fourth lens 400, the fifth lens 500, and the sixth lens 600 are made of quartz glass, the refractive index of the quartz glass is 1.45, and the abbe number of the quartz glass is 67.7. The quartz glass has high transmittance, low linear expansion coefficient and good uniformity, so that the telecentric laser field lens has strong laser damage resistance, high transmittance and good imaging quality.

With reference to fig. 2 to 12, the following provides a specific embodiment to supplement the technical effects achieved by the above embodiments of the present invention.

In this embodiment, the working distance of the laser field lens is 220mm, there may be two entrance pupils, which are 14mm and 20mm respectively, and the working wavelength band is: 1064 nm.

Referring to fig. 2 to 5, two optical path imaging diagrams corresponding to different entrance pupils are respectively shown, and comparing the two images shows that the aperture of the light spot on the left side of fig. 2 is smaller and is 14 mm; in fig. 3, the aperture of the light spot is 20mm, and the distance from the light spot to the first lens of the lens is also slightly different, namely 42mm and 50mm, and the 20mm light spot is slightly longer.

Referring to fig. 6 and 7, MTF curves corresponding to two different light spots are generally used in optical design to evaluate the resolution characteristics of a designed lens. Comparing the two figures shows that the imaging resolution of two different light spots is good, and the curves of all the fields of view are almost overlapped and are very close to the diffraction limit.

Reference is made to the dot-matrix diagrams of two different spot images shown in figures 8 and 9. Where DBJ denotes an object side field of view and IMA denotes an image side field of view. Airy Radius represents the Airy spot Radius, RMS Radius represents the mean-squared error Radius of the diffuse spots, all in microns. As can be seen from FIG. 8, the Airy Radius of the 14mm spot is 15.51 μm, the center RMS Radius is 1.399 μm, and the edge RMS Radius is 3.009, which is smaller than the Airy Radius, and it can be seen from the optical theory that the RMS Radius is very good for both on-axis and off-axis point energy concentration and aberration correction, achieving ideal resolution. The RMSRadius shown in the dot diagram of the 20mm light spot is slightly larger, but is also smaller than the Airy Radius, so that the RMSRadius also has good resolution.

Referring to the field curvature and distortion graphs shown in fig. 10 and fig. 11, the field curvature is only 0.2mm, the distortion is less than 2%, the field curvature of the lens is small, which indicates that the deviation degree of focusing is very small, i.e. the flat field effect is very good, which is very beneficial to the application of the laser application field, and the distortion is also in a reasonable range.

Referring to the relative illumination curve shown in fig. 12, it can be seen that the energy intensity of the lens image square field is very high, which is very suitable for laser applications.

To sum up, the embodiment of the utility model provides a telecentric laser field lens that designs has flat field effectual, high resolution, characteristics such as the aberration is minimum.

According to the utility model discloses laser scanning system of second aspect embodiment, include according to the utility model discloses the telecentric laser field lens of above-mentioned first aspect embodiment.

According to the utility model discloses laser scanning system, the laser instrument sends the laser of a branch of fixed facula, after the reflection of X/Y galvanometer, enter into telecentric laser field lens, thereby laser is in proper order through first lens 100, second lens 200, third lens 300, fourth lens 400, fifth lens 500 and sixth lens 600, through the many refractions of lens, make the exit pupil of camera lens at image space infinity, the chief ray of having realized the focus light beam all is perpendicular to focal plane under the condition of any angle of vision, make telecentric laser field lens have better flat field effect, thereby make laser beam machining can go on steadily high-efficiently.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an illustrative embodiment," "an example," "a specific example," or "some examples" or the like mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

While embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that: various changes, modifications, substitutions and alterations can be made to the embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims (10)

1. A telecentric laser field lens is characterized in that: including first lens, second lens, third lens, fourth lens, fifth lens and the sixth lens that sets gradually along laser propagation direction, first lens is biconcave sphere negative lens, the second lens is the unsmooth sphere negative lens, the third lens is the unsmooth sphere positive lens, the fourth lens is plano-convex sphere positive lens, the fifth lens is the biconvex sphere positive lens, the sixth lens is biplanar lens.

2. A telecentric laser field lens as recited in claim 1, wherein: the first lens, the second lens, the third lens, the fourth lens, the fifth lens and the sixth lens are all arranged in the main lens barrel.

3. A telecentric laser field lens as recited in claim 2, wherein: further comprising a lock ring through which the first lens, the second lens, the third lens, the fourth lens, the fifth lens, and the sixth lens are all fixed in the main barrel.

4. A telecentric laser field lens as recited in claim 3, wherein: and space rings are arranged between the first lens and the second lens, between the second lens and the third lens, between the third lens and the fourth lens, between the fourth lens and the fifth lens and between the fifth lens and the sixth lens.

5. A telecentric laser field lens as set forth in claim 4, wherein: and a rubber ring with a buffering function is arranged on one side of the sixth lens relative to the spacing ring.

6. A telecentric laser field lens as recited in claim 1, wherein: the first lens comprises a first spherical surface and a second spherical surface, the radius of curvature of the first spherical surface is-110.16 +/-0.11016 millimeters, and the radius of curvature of the second spherical surface is-234.29 +/-0.23429 millimeters; the second lens comprises a third spherical surface and a fourth spherical surface, the radius of curvature of the third spherical surface is-40.0 +/-0.04 mm, and the radius of curvature of the fourth spherical surface is 66.12 +/-0.06612 mm; the third lens comprises a fifth spherical surface and a sixth spherical surface, the radius of curvature of the fifth spherical surface is-247.7 +/-0.2477 mm, and the radius of curvature of the sixth spherical surface is 85.18 +/-0.08518 mm; the fourth lens comprises a first plane and a seventh spherical surface, and the radius of curvature of the seventh spherical surface is 134.75 +/-0.13475 millimeters; the fifth lens comprises an eighth spherical surface and a ninth spherical surface, the radius of curvature of the eighth spherical surface is 206.4 +/-0.2064 millimeters, and the radius of curvature of the ninth spherical surface is 438.76 +/-0.43876 millimeters; the sixth lens includes a second plane and a third plane.

7. A telecentric laser field lens as recited in claim 1, wherein: the central thickness of the first lens is 6.0 +/-0.1 mm; the central thickness of the second lens is 16.0 +/-0.1 mm; the central thickness of the third lens is 15.0 +/-0.1 mm; the central thickness of the fourth lens is 16.0 +/-0.1 mm; the center thickness of the fifth lens is 17.0 +/-0.1 mm; the center thickness of the sixth lens is 5.0 +/-0.1 mm.

8. A telecentric laser field lens as recited in claim 1, wherein: the air space between the first lens and the second lens on the optical axis is 16.0 mm; the air space between the second lens and the third lens on the optical axis is 1.3 mm; the air space between the third lens and the fourth lens on the optical axis is 1.3 mm; the air space between the fourth lens and the fifth lens on the optical axis is 1.3 mm; an air space between the fifth lens and the sixth lens on the optical axis is 12.0 mm.

9. A telecentric laser field lens as recited in claim 1, wherein: the first lens, the second lens, the third lens, the fourth lens, the fifth lens and the sixth lens are all made of quartz glass, the refractive index of the quartz glass is 1.45, and the abbe number of the quartz glass is 67.7.

10. A laser scanning system comprising the telecentric laser field lens of any one of claims 1 to 9.

Images