An industrial lens

Abstract

The application discloses an industrial lens, which comprises: a focusing lens group and a fixed lens group arranged along an optical axis from an object side to an image side; the focusing lens group moves focusing along the optical axis; the focusing lens group comprises a first lens with positive refractive power, a second lens with negative refractive power, a third lens with positive refractive power, a fourth lens with negative refractive power, a fifth lens with positive refractive power, a sixth lens with negative refractive power, a seventh lens with positive refractive power, an eighth lens with positive refractive power, a ninth lens with positive refractive power and a tenth lens with negative refractive power arranged along the optical axis from the object side to the image side; the fixed lens group comprises an eleventh lens with positive refractive power and a twelfth lens with negative refractive power arranged along the optical axis from the object side to the image side; the first lens to the twelfth lens are all glass lenses; and the maximum value DISG.MAX of optical distortion of the industrial lens satisfies: |DISG.MAX|<=0.1000%. The industrial lens of the application can be applied to a larger range of working distances, and has the characteristics of large aperture, high imaging resolution and low optical distortion.

Description

Technical Field

[0001] This invention relates to the field of optical device technology, and more particularly to an industrial lens. Background Technology

[0002] With the advancement of technology and the continuous development of the intelligent industry, the application of lenses is no longer limited to traditional photography; its application areas are gradually expanding to industrial inspection, robot vision, and other fields. As a core component of industrial inspection and robot vision, the imaging quality of industrial lenses is one of the key factors affecting inspection and recognition results.

[0003] To ensure high production efficiency and yield, as well as high recognition accuracy in machine vision, the demands on the performance of industrial lenses required for detection and recognition are constantly increasing. Improving the performance of industrial lenses, such as resolution, applicable working distance, optical distortion, and aperture, has become an urgent technical problem to be solved. Summary of the Invention

[0004] This invention provides an industrial lens that ensures a wide applicable working distance range, a larger aperture, higher imaging resolution, and lower optical distortion.

[0005] This invention provides an industrial lens, comprising: a focusing lens group and a fixed lens group arranged sequentially along the optical axis from the object side to the image side; the focusing lens group moves along the optical axis to focus;

[0006] The focusing lens group includes a first lens with positive optical power, a second lens with negative optical power, a third lens with positive optical power, a fourth lens with negative optical power, a fifth lens with positive optical power, a sixth lens with negative optical power, a seventh lens with positive optical power, an eighth lens with positive optical power, a ninth lens with positive optical power, and a tenth lens with negative optical power, arranged sequentially along the optical axis from the object side to the image side.

[0007] The fixed lens group includes an eleventh lens with positive optical power and a twelfth lens with negative optical power arranged sequentially along the optical axis from the object side to the image side.

[0008] Among them, the first lens to the twelfth lens are all glass lenses;

[0009] The maximum optical distortion DISG.MAX of the industrial lens satisfies: |DISG.MAX|≤0.1000%.

[0010] Optionally, the overall focal length (EFL) of the industrial lens satisfies: 2.1950 ≤ TTL / EFL ≤ 2.2300;

[0011] Wherein, TTL is the distance from the front end of the first lens to the image plane of the industrial lens.

[0012] Optionally, the shape factor ξ1 of the first lens satisfies: 1.1500≤|ξ1|≤1.6800.

[0013] Optionally, the Abbe number Vd4 of the fourth lens and the Abbe number Vd5 of the fifth lens satisfy: 2.4100≤Vd5 / Vd4.

[0014] Optionally, the Abbe number Vd5 of the fifth lens and the Abbe number Vd6 of the sixth lens satisfy: 1.6900≤Vd5 / Vd6.

[0015] Optionally, the total optical power Φ4-6 of the fourth to sixth lenses and the total optical power Φ7-8 of the seventh to eighth lenses satisfy: -1.1500≤Φ4-6 / Φ7-8≤-1.0800.

[0016] Optionally, the optical power Φ11 of the eleventh lens and the optical power Φ12 of the twelfth lens satisfy: -0.8900≤Φ11 / Φ12≤-0.7200.

[0017] Optionally, the total optical power Φ2-7 of the second lens to the seventh lens and the total optical power Φ8-10 of the eighth lens to the tenth lens satisfy: -1.0300≤Φ2-7 / Φ8-10≤-0.9100.

[0018] Optionally, the maximum effective aperture DM among the effective apertures of the first lens to the twelfth lens satisfies: 3.5400≤TTL / DM≤3.7800;

[0019] Wherein, TTL is the distance from the front end of the first lens to the image plane of the industrial lens.

[0020] Optionally, the field of view (FOV) of the industrial lens satisfies: FOV ≥ 21.1000°; and / or,

[0021] The aperture number F.NO of the industrial lens satisfies: F.NO≤2.3100.

[0022] The technical solution of this invention employs twelve glass lenses, from the first to the twelfth lens, to form an industrial lens. The first to the tenth lenses constitute a focusing lens group, while the eleventh and twelfth lenses form a fixed lens group. By rationally allocating the optical power of each lens, the industrial lens can achieve a focal length of 50mm within a working distance of 200mm to 1000mm, with an optimal object distance of 300mm. Furthermore, the maximum aperture of the industrial lens can reach 2.2, and the maximum optical distortion (DISG.MAX) can be less than 0.1%, thus meeting the requirements for low distortion and high resolution imaging. This results in a high-resolution industrial lens with high image quality, such as an MTF180lp / mm>0.4. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of an industrial lens at the optimal object distance provided in an embodiment of the present invention;

[0024] Figure 2 yes Figure 1 The diagram shows the optical fan structure of an industrial lens at the optimal object distance.

[0025] Figure 3 yes Figure 1 The diagram shows the field curvature distortion curve of an industrial lens at the optimal object distance.

[0026] Figure 4 yes Figure 1 The diagram shows the MTF of an industrial lens at the optimal object distance.

[0027] Figure 5 yes Figure 1 The diagram shows the axial chromatic aberration of an industrial lens at the optimal object distance.

[0028] Figure 6 yes Figure 1 The diagram shows the transverse chromatic aberration of an industrial lens at the optimal object distance.

[0029] Figure 7 This is a schematic diagram of another industrial lens provided by an embodiment of the present invention at the optimal object distance;

[0030] Figure 8 yes Figure 7 The diagram shows the optical fan structure of an industrial lens at the optimal object distance.

[0031] Figure 9 yes Figure 7 The diagram shows the field curvature distortion curve of an industrial lens at the optimal object distance.

[0032] Figure 10 yes Figure 7 The diagram shows the MTF of an industrial lens at the optimal object distance.

[0033] Figure 11 yes Figure 7 The diagram shows the axial chromatic aberration of an industrial lens at the optimal object distance.

[0034] Figure 12 yes Figure 7 The diagram shows the transverse chromatic aberration of an industrial lens at the optimal object distance.

[0035] Figure 13 This is a schematic diagram of the structure of another industrial lens under optimal object distance provided in an embodiment of the present invention;

[0036] Figure 14 yes Figure 13 The diagram shows the optical fan structure of an industrial lens at the optimal object distance.

[0037] Figure 15 yes Figure 13 The diagram shows the field curvature distortion curve of an industrial lens at the optimal object distance.

[0038] Figure 16 yes Figure 13 The diagram shows the MTF of an industrial lens at the optimal object distance.

[0039] Figure 17 yes Figure 13 The diagram shows the axial chromatic aberration of an industrial lens at the optimal object distance.

[0040] Figure 18 yes Figure 13 The diagram shows the vertical chromatic aberration of an industrial lens at the optimal object distance. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be fully described below with reference to the accompanying drawings of the embodiments of this invention through specific implementation methods. Obviously, the described embodiments are only some, not all, embodiments of this invention. Various modifications and variations can be made to this invention without departing from the spirit or scope of this invention, which will be obvious to those skilled in the art. Therefore, this invention is intended to cover modifications and variations of this invention that fall within the scope of the corresponding claims (the claimed technical solutions) and their equivalents.

[0042] Furthermore, the terms "first," "second," and similar terms used in the embodiments of this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, terms such as "an," "one," or "the" do not indicate a quantity limitation, but rather indicate the presence of at least one. Terms such as "including" or "comprising" mean that the element or object preceding the word encompasses the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are only used to indicate relative positional relationships, and these relative positional relationships may change accordingly when the absolute position of the described object changes. In addition, descriptions of "same" or "equal" in the embodiments of this disclosure do not mean that two objects are completely equal in size or shape; they are allowed to be approximately the same or approximately equal within a certain error range.

[0043] It should be noted that the implementation methods provided in the embodiments of the present invention can be combined with each other without contradiction.

[0044] Figure 1 This is a schematic diagram of the structure of an industrial lens at the optimal object distance according to an embodiment of the present invention, as shown below. Figure 1 As shown, the industrial lens includes: a focusing lens group G1 and a fixed lens group G2 arranged sequentially along the optical axis from the object side to the image side; the focusing lens group G1 moves along the optical axis to focus; the focusing lens group G1 includes a first lens 10 with positive optical power, a second lens 20 with negative optical power, a third lens 30 with positive optical power, a fourth lens 40 with negative optical power, a fifth lens 50 with positive optical power, a sixth lens 60 with negative optical power, a seventh lens 70 with positive optical power, an eighth lens 80 with positive optical power, a ninth lens 90 with positive optical power, and a tenth lens 100 with negative optical power, arranged sequentially along the optical axis from the object side to the image side; the fixed lens group G2 includes an eleventh lens 110 with positive optical power and a twelfth lens 120 with negative optical power, arranged sequentially along the optical axis from the object side to the image side.

[0045] As can be understood, optical power equals the difference between the convergence of the image-side beam and the convergence of the object-side beam; it characterizes the ability of an optical system to deflect light. The larger the absolute value of optical power, the stronger the bending ability of light; the smaller the absolute value, the weaker the bending ability. When optical power is positive, the refraction of light is converging; when optical power is negative, the refraction of light is diverging. Optical power can be used to characterize a single refractive surface of a lens (i.e., one surface of the lens), a single lens, or a system formed by multiple lenses (i.e., a lens group).

[0046] In this embodiment, by setting the first lens 10 in the focusing lens group G1 to have positive optical power, the second lens 20 to have negative optical power, the third lens 30 to have positive optical power, the fourth lens 40 to have negative optical power, the fifth lens 50 to have positive optical power, the sixth lens 60 to have negative optical power, the seventh lens 70 to have positive optical power, the eighth lens 80 to have positive optical power, the ninth lens 90 to have positive optical power, and the tenth lens 100 to have negative optical power, and by setting the eleventh lens 110 in the fixed lens group G2 to have positive optical power and the twelfth lens 120 to have negative optical power, the optical power of each lens is reasonably allocated, so that the lenses cooperate with each other. Within a working distance of 200mm to 1000mm, the focal length of the industrial lens can reach 50mm and the maximum aperture F2.2 can be achieved by moving the focusing lens group G1, while meeting the imaging quality requirements of low distortion and high resolution, so that the industrial lens has high resolving power. The optimal object distance for industrial lenses is 300mm, and the imaging quality of industrial lenses can reach MTF180lp / mm>0.4.

[0047] As a feasible embodiment, the optical power Φ1 of the first lens 10 ranges from 0.0140 to 0.0160; the optical power Φ2 of the second lens 20 ranges from -0.0280 to -0.0250; the optical power Φ3 of the third lens 30 ranges from 0.0210 to 0.0240; the optical power Φ4 of the fourth lens 40 ranges from -0.0470 to -0.0410; the optical power Φ5 of the fifth lens 50 ranges from 0.0350 to 0.0380; and the optical power Φ6 of the sixth lens 60 ranges from -0.0460 to -0.0420. The optical power Φ7 of the seventh lens 70 has a range of 0.0180 ≤ Φ7 ≤ 0.0220; the optical power Φ8 of the eighth lens 80 has a range of 0.0270 ≤ Φ8 ≤ 0.0300; the optical power Φ9 of the ninth lens 90 has a range of 0.0330 ≤ Φ9 ≤ 0.0420; the optical power Φ10 of the tenth lens 100 has a range of -0.0540 ≤ Φ10 ≤ -0.0440; the optical power Φ11 of the eleventh lens 110 has a range of 0.0110 ≤ Φ11 ≤ 0.0180; and the optical power Φ12 of the twelfth lens 120 has a range of -0.0220 ≤ Φ12 ≤ -0.0150. Thus, by reasonably setting the optical power range of each lens, the imaging requirements of large aperture, low distortion, and high resolution can be met.

[0048] Optionally, the maximum optical distortion (DISG.MAX) of the industrial lens satisfies: |DISG.MAX| ≤ 0.1000%. Thus, by ensuring that the absolute value of the maximum optical distortion (DISG.MAX) of the industrial lens is less than 0.1%, the industrial lens as a whole has low optical distortion, improving the distortion phenomenon during industrial lens imaging and enhancing the imaging quality of the industrial lens.

[0049] Optionally, the first lens 10 to the twelfth lens 120 are all glass lenses.

[0050] Glass lenses, in particular, possess a low coefficient of thermal expansion and excellent stability, resulting in superior thermal stability. This allows industrial lenses to maintain good resolution over a wide temperature range (-40℃ to 80℃) even when handling high optical power. Furthermore, compared to plastic lenses, glass offers a wider range of material choices, with more freedom in selecting its refractive index and Abbe constant. This allows for better control over advanced aberrations and chromatic aberrations in industrial lenses, meeting the demands of complex operating conditions.

[0051] Optionally, the focusing lens group G1 is also provided with a first aperture stop 130, which is disposed in the optical path between the first lens 10 and the second lens 20. The first aperture stop 130 can adjust the propagation direction of the light beam passing through the first lens 10.

[0052] Optionally, the focusing lens group G1 is also provided with a second aperture stop 140, which is disposed in the optical path between the sixth lens 60 and the seventh lens 70. The second aperture stop can adjust the propagation direction of the light beam passing through the sixth lens 60.

[0053] Optionally, the fourth lens 40, the fifth lens 50, and the sixth lens 60 constitute a cemented triplet lens.

[0054] The cemented configuration of the fourth lens 40, fifth lens 50, and sixth lens 60 can be understood as the image-side of the fourth lens 40 being bonded to the object-side of the fifth lens 50, and the image-side of the fifth lens 50 being bonded to the object-side of the sixth lens 60. By forming a cemented triplet lens, the air gap between the fourth lens 40 and the fifth lens 50, as well as between the fifth lens 50 and the sixth lens 60, can be reduced. This helps to reduce the overall optical length of the industrial lens and also reduces tolerance sensitivity issues such as tilting / eccentricity during lens assembly, simplifying the assembly process in industrial lens manufacturing and improving equipment efficiency. Simultaneously, the cemented configuration of the fourth lens 40, fifth lens 50, and sixth lens 60 can reduce light loss caused by inter-lens reflection, improve illumination, and reduce the risk of ghosting. Furthermore, cemented lenses can be used to minimize or eliminate chromatic aberration, thereby improving image quality, reducing light energy reflection loss, and enhancing the sharpness of the lens image. In an optional embodiment, the fourth lens 40 and the fifth lens 50 can be supported by a gasket or glued together, and the fifth lens 50 and the sixth lens 60 can also be supported by a gasket or glued together. The specific gluing method is not limited in the embodiments of the present invention.

[0055] Optionally, the ninth lens 90 and the tenth lens 100 form a cemented doublet.

[0056] In this embodiment, the cementing of the ninth lens 90 and the tenth lens 100 can be understood as the image-side surface of the ninth lens 90 being bonded to the object-side surface of the tenth lens 100. By cementing the ninth lens 90 and the tenth lens 100, the air gap between them can be reduced, which helps to reduce the overall optical length of the industrial lens. It also reduces tolerance sensitivity issues such as tilting / eccentricity during lens assembly, simplifies the assembly process in industrial lens manufacturing, and improves equipment efficiency. Simultaneously, the cementing of the ninth lens 90 and the tenth lens 100 can reduce light loss caused by inter-lens reflection, improving illumination. Furthermore, cemented lenses can be used to minimize or eliminate chromatic aberration, thereby improving image quality, reducing light energy reflection loss, and enhancing the sharpness of the lens image. In an optional embodiment, the ninth lens 90 and the tenth lens 100 can be supported by a gasket or bonded with adhesive; the specific bonding method is not limited in this embodiment.

[0057] Based on the above embodiments, optionally, the overall focal length EFL of the industrial lens satisfies: 2.1950≤TTL / EFL≤2.2300; where TTL is the distance from the front end of the first lens 10 to the image plane IMG of the industrial lens.

[0058] The distance between the front end of the first lens 10 and the image plane IMG of the industrial lens can be understood as the total length of the optical system of the industrial lens. By making the ratio of the total length TTL of the optical system of the industrial lens to its overall focal length EFL range between 2.1950 and 2.2300, it is beneficial to reduce the size of the optical system of the industrial lens, so that the industrial lens can be adapted to more usage environments and reduce the material cost of the lens.

[0059] Optionally, the shape factor ξ1 of the first lens 10 satisfies: 1.1500≤|ξ1|≤1.6800.

[0060] The shape factor, as a parameter affecting the basic optical performance of a lens, can be adjusted by changing the lens's curvature, aperture, and material, thereby optimizing the focusing capability and imaging quality of the entire optical system of an industrial lens. The first lens 10 can be made of a high-refractive-index material, and its optical power is positive, located near the first aperture stop 130. By giving the first lens 10 a large shape factor, satisfying 1.1500 ≤ |ξ1| ≤ 1.6800, aberrations can be corrected more effectively, improving image quality.

[0061] Optionally, the Abbe number Vd4 of the fourth lens 40 and the Abbe number Vd5 of the fifth lens 50 satisfy: 2.4100≤Vd5 / Vd4.

[0062] The fourth lens 40 and the fifth lens 50 form a cemented lens. By making the ratio of the Abbe number Vd5 of the fifth lens 50 to the Abbe number Vd4 of the fourth lens 40 greater than or equal to 2.1400, there is a large difference between the Abbe number Vd4 of the fourth lens 40 and the Abbe number Vd5 of the fifth lens 50. This effectively corrects the chromatic aberration of the system, improves the image quality, and provides higher image clarity. Therefore, when using industrial lenses for defect detection, the detection effect is higher and the detection results are more accurate.

[0063] Optionally, the Abbe number Vd5 of the fifth lens 50 and the Abbe number Vd6 of the sixth lens 60 satisfy: 1.6900≤Vd5 / Vd6.

[0064] The fifth lens 50 and the sixth lens 60 form a cemented lens. By making the ratio of the Abbe number Vd5 of the fifth lens 50 to the Abbe number Vd6 of the sixth lens 60 greater than or equal to 1.6900, a large difference is created between the Abbe numbers Vd5 of the fifth lens 50 and Vd6 of the sixth lens 60. This effectively corrects chromatic aberration in the system, improves image quality, and provides higher image clarity. As a result, when using industrial lenses for defect detection, the detection effect is high, and the detection results are highly accurate. Meanwhile, the fourth lens 40, the fifth lens 50, and the sixth lens 60 constitute a cemented triplet lens. By ensuring that the Abbe number Vd4 of the fourth lens 40 and the Abbe number Vd5 of the fifth lens 50 satisfy Vd5 / Vd4≥2.4100, and the Abbe number Vd5 of the fifth lens 50 and the Abbe number Vd6 of the sixth lens 60 satisfy Vd5 / Vd6≥1.6900, the Abbe numbers of adjacent lenses in this cemented triplet lens have a large difference, thereby effectively correcting the chromatic aberration of the system, improving the imaging quality, and making the detection effect clearer and more accurate.

[0065] Optionally, the total optical power Φ4-6 of the fourth lens 40 to the sixth lens 60 and the total optical power Φ7-8 of the seventh lens 70 to the eighth lens 80 satisfy: -1.1500≤Φ4-6 / Φ7-8≤-1.0800.

[0066] In this context, the total optical power Φ4-6 of the fourth lens 40 to the sixth lens 60 can be understood as the overall optical power of the lens group formed by the fourth lens 40 to the sixth lens 60, and the total optical power Φ7-8 of the seventh lens 70 to the eighth lens 80 can be understood as the overall optical power of the lens group formed by the seventh lens 70 to the eighth lens 80. The lens group formed by the fourth lens 40 to the sixth lens 60 and the lens group formed by the seventh lens 70 to the eighth lens 80 are located in the middle of the optical system of the entire industrial lens, and the light beam is at a relatively high height. By making the total optical power Φ4-6 of the fourth lens 40 to the sixth lens 60 and the seventh lens 70 to the eighth lens 80... The total optical power Φ7-8 of lenses 0 to 80 satisfies the above conditions, making the overall optical power of the lens group composed of lenses 40 to 60 opposite to the overall optical power of the lens group composed of lenses 70 to 80. That is, lenses 40 to 80 form two lens groups, and these two lens groups have positive and negative optical powers respectively. At the same time, the absolute values ​​of the two lens groups are close, which can effectively reduce spherical aberration, reduce the defocus between different wavelengths, and improve the on-axis imaging quality. Therefore, when industrial lenses are used for defect detection, they have a higher detection effect and the detection results are clearer and more accurate.

[0067] Optionally, the optical power Φ11 of the eleventh lens 110 and the optical power Φ12 of the twelfth lens 120 satisfy: -0.8900≤Φ11 / Φ12≤-0.7200.

[0068] The lens group consisting of the eleventh lens 110 and the twelfth lens 120 is located at the end of the optical system of the industrial lens. The ratio of the optical power of the eleventh lens 110 to the twelfth lens 120 is negative, so the optical power of the eleventh lens 110 and the twelfth lens 120 are positive and negative respectively, and there is a large difference between them. This constitutes the Pittswan scene, which can effectively correct field curvature, improve the consistency of the overall image resolution, and is more conducive to the design of a large aperture optical system.

[0069] Optionally, the total optical power Φ2-7 of the second lens 20 to the seventh lens 70 and the total optical power Φ8-10 of the eighth lens 80 to the tenth lens 100 satisfy: -1.0300≤Φ2-7 / Φ8-10≤-0.9100.

[0070] The total optical power Φ2-7 of the second lens 20 to the seventh lens 70 can be understood as the overall optical power of the lens group formed by the second lens 20 to the seventh lens 70, and the total optical power Φ8-10 of the eighth lens 80 to the tenth lens 100 can be understood as the overall optical power of the lens group formed by the eighth lens 80 to the tenth lens 100. By making the ratio of the total optical power Φ2-7 of the second lens 20 to the seventh lens 70 to the total optical power Φ8-10 of the eighth lens 80 to the tenth lens 100 negative, the optical power of the lens group formed by the second lens 20 to the seventh lens 70 is opposite to that of the lens group formed by the eighth lens 80 to the tenth lens 100, and the absolute values ​​of the two lens groups are close, forming a symmetrical optical power structure. This can effectively correct the optical distortion of the system, reduce the distortion during imaging, ensure the integrity of the sampling of the object under test, and improve the detection accuracy.

[0071] Optionally, the maximum effective aperture DM among the effective apertures of the first lens 10 to the twelfth lens 12 satisfies: 3.5400≤TTL / DM≤3.7800; where TTL is the distance from the front end of the first lens 10 to the image plane IMG of the industrial lens.

[0072] The distance between the front end of the first lens 10 and the image plane IMG of the industrial lens can be understood as the total length of the optical system of the industrial lens. The effective aperture of the lens reflects its maximum light transmission capability and directly affects the illuminance of the focal plane. By limiting the ratio of the total optical system length TTL to the maximum effective aperture DM of each lens to meet the above conditions, while ensuring a constant image height, the shorter the total length of the optical system of the industrial lens and the smaller the maximum effective aperture DM, the smaller the corresponding volume, thus achieving a large image height while reducing the volume.

[0073] Optionally, the field of view (FOV) of the industrial lens should meet the following requirement: FOV ≥ 21.1000°. This setting allows the industrial lens to have a large field of view, meeting the inspection requirements for a high inspection range.

[0074] Optionally, the aperture number F.NO of the industrial lens must satisfy: F.NO≤2.3100.

[0075] Industrial lenses with large target surfaces and large apertures are typically bulky and require numerous lenses for aberration correction. However, this invention achieves high-quality imaging on ultra-large target surfaces using only 12 glass spherical lenses with optical power. This keeps the total length within 115.45mm, minimizing both cost and size while ensuring clear image resolution.

[0076] Based on the above embodiments, optionally, the object-side surface of the first lens 10 is convex and the image-side surface is concave, that is, the first lens 10 can be a meniscus lens; the object-side surface and the image-side surface of the second lens 20 are both concave; the object-side surface and the image-side surface of the third lens 30 are both convex; the object-side surface and the image-side surface of the fourth lens 40 are both concave; the object-side surface and the image-side surface of the fifth lens 50 are both convex; the object-side surface and the image-side surface of the sixth lens 60 are both concave; the object-side surface of the seventh lens 70 is concave and the image-side surface is convex; the object-side surface and the image-side surface of the eighth lens 80 are both convex; the object-side surface and the image-side surface of the ninth lens 90 are both convex; the object-side surface and the image-side surface of the tenth lens 100 are both concave; the object-side surface and the image-side surface of the eleventh lens 110 are both convex; and the object-side surface and the image-side surface of the twelfth lens 120 are both concave.

[0077] In this context, the object-side surface of a lens can be understood as the surface of the lens closest to the object plane, and the image-side surface can be understood as the surface of the lens closest to the image plane. A concave object-side surface means that the object-side surface of the lens is recessed towards the object plane near the optical axis, and a convex object-side surface means that the object-side surface of the lens is convex towards the object plane near the optical axis. Similarly, a concave image-side surface means that the image-side surface of the lens is recessed towards the image plane near the optical axis, and a convex image-side surface means that the image-side surface of the lens is convex towards the image plane near the optical axis.

[0078] In this embodiment, by reasonably setting the surface shape of each lens, the light path can be made smoother, the relative illumination of the image can be improved, and the imaging effect can be enhanced. This helps to reduce optical distortion, improve the detection effect, and ensure the clarity and accuracy of the detection.

[0079] In summary, the embodiments of the present invention utilize a structure consisting of 12 glass spherical lenses with optical power to form an industrial lens. By rationally setting the materials of each lens and rationally allocating the optical power of each lens, the industrial lens can achieve a design that balances low distortion, large target area, and high resolution within a working distance range of 200mm-1000mm. Furthermore, the overall focal length (EFL) of the industrial lens optical system can reach 50mm, the maximum aperture (F) can reach 2.2, the optimal object distance can be 300mm, the maximum optical distortion (DISG.MAX) can meet the requirement of |DISG.MAX| < 0.1%, and the image quality can reach MTF 180lp / mm > 0.4, thereby realizing a high-performance industrial lens design scheme.

[0080] The following describes specific embodiments of industrial lenses applicable to the above-described embodiments with reference to the accompanying drawings.

[0081] In one feasible embodiment, Table 1 details a feasible implementation method. Figure 1 The specific optical physical parameters of the industrial lens are shown.

[0082] Table 1. Design of optical physical parameters for an industrial lens.

[0083] Scope of protection Example 1 lower limit upper limit TTL / EFL 2.2219 2.1950 2.2300 TTL / DM 3.5822 3.5400 3.7800 EFL 51.2260 50.6500 52.6100 TTL 113.8190 112.9400 115.5400 DM 31.7734 31.7700 33.3200 FOV 22.1733 21.1000 22.4200 F.NO 2.2399 2.2100 2.3100 Vd5 / Vd4 3.7521 2.4100 3.8500 Vd5 / Vd6 3.6039 1.6900 3.6700 Φ4-6 / Φ7-8 -1.1335 -1.1500 -1.0800 Φ11 / Φ12 -0.8807 -0.8900 -0.7200 Φ2-7 / Φ8-10 -0.9965 -1.0300 -0.9100 DISG.MAX -0.0945％ -0.1000％ 0.0000％ ξ1 1.6724 1.1500 1.6800 Φ1 0.0157 0.0140 0.0160 Φ2 -0.0267 -0.0280 -0.0250 Φ3 0.0233 0.0210 0.0240 Φ4 -0.0428 -0.0470 -0.0410 Φ5 0.0356 0.0350 0.0380 Φ6 -0.0426 -0.0460 -0.0420 Φ4-6 -0.0511 -0.0570 -0.0500 Φ7 0.0182 0.0180 0.0220 Φ8 0.0278 0.0270 0.0300 Φ9 0.0411 0.0330 0.0420 Φ10 -0.0537 -0.0540 -0.0440 Φ9-10 -0.0046 -0.0040 -0.0070 Φ11 0.0165 0.0110 0.0180 Φ12 -0.0187 -0.0220 -0.0150

[0084] Table 2 shows the design parameters of each lens in an industrial lens, including surface type, radius of curvature, thickness, and material, which correspond to those in Table 1.

[0085] Table 2. Parameter Design of Each Lens in Industrial Lenses

[0086]

[0087] The industrial lens of this embodiment includes a first lens 10, a first aperture 130, a second lens 20, a third lens 30, a fourth lens 40, a fifth lens 50, a sixth lens 60, a second aperture 140, a seventh lens 70, an eighth lens 80, a ninth lens 90, a tenth lens 100, an eleventh lens 110, a twelfth lens 120, and a filter glass 150, arranged sequentially along the optical axis from the object side to the image side. The surface numbering is based on the sequential order of the lenses, where "1" represents the object-side surface of the first lens 10, "2" represents the image-side surface of the first lens 10, and so on. "IMG" represents the image plane of the lens. The radius of curvature represents the curvature of the lens surface; a positive value indicates that the surface bends towards the image plane, and a negative value indicates that the surface bends towards the object plane. "Infinite" indicates that the surface is flat and the radius of curvature is infinite. The thickness represents the axial distance between the current surface and the next surface. The refractive index represents the ability of the material between the current surface and the next surface to deflect light; a space indicates that the current position is air and the refractive index is 1. The Abbe number represents the dispersion characteristics of the material between the current surface and the next surface; a space indicates that the current position is air. Half-aperture indicates half the aperture size of the current surface. In this embodiment, when the 20th surface spacing is 23.008mm, it can focus to an object distance of 200mm; when the 20th surface spacing is 9.422mm, it can focus to an object distance of 1000mm.

[0088] Figure 2 yes Figure 1 The diagram shown illustrates the light fan structure of an industrial lens at optimal object distance. The light fan diagram is one of the most commonly used evaluation methods in modern optical design. For example... Figure 2 As shown, the horizontal axis represents the beam aperture, and the vertical axis represents the transverse aberration. The ideal curve is a straight line coinciding with the horizontal axis, indicating that all rays converge at the same point on the image plane. The interval on the vertical axis of the curve corresponds to the maximum dispersion range of the beam on the ideal image plane. The fan diagram not only reflects monochromatic aberrations at different wavelengths (460nm, 530nm, 620nm) but also represents the magnitude of transverse chromatic aberration. Figure 2 It can be seen that the industrial lens closely approximates the horizontal axis at all wavelengths (460nm, 530nm, 620nm) in all fields of view, indicating that the transverse aberration of each wavelength in the optical system of the industrial lens is well corrected. At the same time, there is no obvious dispersion in each wavelength, indicating that the chromatic aberration of the system is also well corrected, thus ensuring that the optical system can achieve the high-resolution imaging requirements.

[0089] Figure 3 yes Figure 1 The diagram shown illustrates the field curvature distortion curve of an industrial lens at the optimal object distance, as follows: Figure 3As shown, in the coordinate system on the left side of the figure, the horizontal coordinate represents the magnitude of the field curvature, in mm; the vertical coordinate represents the normalized image height, which has no unit; where T represents the meridion and S represents the sagitta; from Figure 3 It can be seen that the lens provided in this embodiment effectively controls field curvature, meaning that during imaging, the difference in image quality between the center and the periphery is small, resulting in good consistency; in the coordinate system on the right, the horizontal axis represents the magnitude of distortion, expressed as a percentage; the vertical axis represents the normalized image height, which has no unit; from Figure 3 As can be seen, the distortion of the industrial lens provided in this embodiment has been well corrected, with optical distortion less than ±0.1%.

[0090] Figure 4 yes Figure 1 The diagram shows the MTF (Mean Transmission Function) of an industrial lens at the optimal object distance. The MTF is one of the most commonly used and authoritative evaluation methods in modern optical design. The horizontal axis represents the spatial frequency distribution of line pairs in object space as imaged onto the image plane by the optical system, in periods / mm. The vertical axis represents the magnitude of the optical transfer function. The diagram shows the trend of the optical transfer function along the meridional (T) and sagittal (S) directions corresponding to different fields of view (0.00mm, 3.45mm, 5.75mm, 8.05mm, 10.53mm, and 11.50mm) directions as the spatial frequency increases. The ideal curve is a straight line coinciding with the system's diffraction limit, indicating that the geometric aberrations of the light rays at all positions are less than the wave phase aberration caused by the physical limitations of the system itself, and can be ignored. Figure 4 It can be seen that the image quality of this industrial lens is higher than 0.4MTF at 180pl / mm from the center field of view to the edge field of view, and the imaging has excellent resolution.

[0091] Figure 5 yes Figure 1 The diagram shown illustrates the axial chromatic aberration of an industrial lens at its optimal object distance. Figure 5 As shown in the figure, the vertical direction represents the normalized 0-field pupil plane, where 0 represents the pupil center, and the vertical vertex represents the pupil vertex; the horizontal direction represents the axial chromatic aberration at different wavelengths (460nm, 530nm, 620nm), in millimeters (mm). Figure 5 It can be seen that the axial chromatic aberration of the entire pupil of the industrial lens is less than 25μm, and the image has excellent clarity.

[0092] Figure 6 yes Figure 1 The diagram shown illustrates the transverse chromatic aberration of an industrial lens at its optimal object distance, as follows: Figure 6 As shown in the diagram, the vertical direction represents the field of view angle, 0 represents the field of view angle incident parallel to the optical axis, and the vertex of the vertical direction represents the maximum half-field of view angle. Figure 6It can be seen that at various wavelengths (460nm, 530nm, 620nm), the transverse chromatic aberration from the center field of view to the edge field of view of the industrial lens is less than 0.6μm, resulting in higher imaging quality.

[0093] In another feasible embodiment, Figure 7 This is a schematic diagram of another industrial lens provided by an embodiment of the present invention at the optimal object distance. Table 3 details another feasible implementation method. Figure 7 The specific optical physical parameters of the industrial lens are shown.

[0094] Table 3. Another optical physical parameter design for industrial lenses

[0095] Scope of protection Example 2 lower limit upper limit TTL / EFL 2.2295 2.1950 2.2300 TTL / DM 3.5497 3.5400 3.7800 EFL 50.6598 50.6500 52.6100 TTL 112.9480 112.9400 115.5400 DM 31.8192 31.7700 33.3200 FOV 22.4183 21.1000 22.4200 F.NO 2.2166 2.2100 2.3100 Vd5 / Vd4 3.8446 2.4100 3.8500 Vd5 / Vd6 3.6617 1.6900 3.6700 Φ4-6 / Φ7-8 -1.1434 -1.1500 -1.0800 Φ11 / Φ12 -0.8436 -0.8900 -0.7200 Φ2-7 / Φ8-10 -0.9104 -1.0300 -0.9100 DISG.MAX -0.0292％ -0.1000％ 0.0000％ ξ1 1.1524 1.1500 1.6800 Φ1 0.0142 0.0140 0.0160 Φ2 -0.0253 -0.0280 -0.0250 Φ3 0.0238 0.0210 0.0240 Φ4 -0.0469 -0.0470 -0.0410 Φ5 0.0370 0.0350 0.0380 Φ6 -0.0450 -0.0460 -0.0420 Φ4-6 -0.0567 -0.0570 -0.0500 Φ7 0.0218 0.0180 0.0220 Φ8 0.0290 0.0270 0.0300 Φ9 0.0370 0.0330 0.0420 Φ10 -0.0512 -0.0540 -0.0440 Φ9-10 -0.0060 -0.0040 -0.0070 Φ11 0.0177 0.0110 0.0180 Φ12 -0.0210 -0.0220 -0.0150

[0096] Table 4 shows the design parameters of each lens in another type of industrial lens, corresponding to Table 3, including surface type, radius of curvature, thickness, and material.

[0097] Table 4. Another parameter design for each lens in industrial lenses.

[0098]

[0099] The industrial lens of this embodiment includes a first lens 10, a first aperture 130, a second lens 20, a third lens 30, a fourth lens 40, a fifth lens 50, a sixth lens 60, a second aperture 140, a seventh lens 70, an eighth lens 80, a ninth lens 90, a tenth lens 100, an eleventh lens 110, a twelfth lens 120, and a filter glass 150, arranged sequentially along the optical axis from the object side to the image side. The surface numbering is based on the sequential order of the lenses, where "1" represents the object-side surface of the first lens 10, "2" represents the image-side surface of the first lens 10, and so on. "IMG" represents the image plane of the lens. The radius of curvature represents the curvature of the lens surface; a positive value indicates that the surface bends towards the image plane, and a negative value indicates that the surface bends towards the object plane. "Infinite" indicates that the surface is flat and the radius of curvature is infinite. The thickness represents the axial distance between the current surface and the next surface. The refractive index represents the ability of the material between the current surface and the next surface to deflect light; a blank space indicates that the current position is air and the refractive index is 1. The Abbe number represents the dispersion characteristics of the material between the current surface and the next surface; a blank space indicates that the current position is air. Half-aperture indicates half the aperture size of the current surface. In this embodiment, when the 20th surface spacing is 21.026mm, it can focus to an object distance of 200mm; when the 20th surface spacing is 8.648mm, it can focus to an object distance of 1000mm.

[0100] Figure 8 yes Figure 7The diagram shown illustrates the light fan structure of an industrial lens at optimal object distance. The light fan diagram is one of the most commonly used evaluation methods in modern optical design. For example... Figure 8 As shown, the horizontal axis represents the beam aperture, and the vertical axis represents the transverse aberration. The ideal curve is a straight line coinciding with the horizontal axis, indicating that all rays converge at the same point on the image plane. The interval on the vertical axis of the curve corresponds to the maximum dispersion range of the beam on the ideal image plane. The fan diagram not only reflects monochromatic aberrations at different wavelengths (460nm, 530nm, 620nm) but also represents the magnitude of transverse chromatic aberration. Figure 8 It can be seen that the industrial lens closely approximates the horizontal axis at all wavelengths (460nm, 530nm, 620nm) in all fields of view, indicating that the transverse aberration of each wavelength in the optical system of the industrial lens is well corrected. At the same time, there is no obvious dispersion in each wavelength, indicating that the chromatic aberration of the system is also well corrected, thus ensuring that the optical system can achieve the high-resolution imaging requirements.

[0101] Figure 9 yes Figure 7 The diagram shown illustrates the field curvature distortion curve of an industrial lens at the optimal object distance, as follows: Figure 9 As shown, in the coordinate system on the left side of the figure, the horizontal coordinate represents the magnitude of the field curvature, in mm; the vertical coordinate represents the normalized image height, which has no unit; where T represents the meridion and S represents the sagitta; from Figure 9 It can be seen that the lens provided in this embodiment effectively controls field curvature, meaning that during imaging, the difference in image quality between the center and the periphery is small, resulting in good consistency; in the coordinate system on the right, the horizontal axis represents the magnitude of distortion, expressed as a percentage; the vertical axis represents the normalized image height, which has no unit; from Figure 9 As can be seen, the distortion of the industrial lens provided in this embodiment has been well corrected, with optical distortion less than ±0.1%.

[0102] Figure 10 yes Figure 7 The diagram shows the MTF (Mean Transmission Function) of an industrial lens at the optimal object distance. The MTF is one of the most commonly used and authoritative evaluation methods in modern optical design. The horizontal axis represents the spatial frequency distribution of line pairs in object space as imaged onto the image plane by the optical system, in periods / mm. The vertical axis represents the magnitude of the optical transfer function. The diagram shows the trend of the optical transfer function along the meridional (T) and sagittal (S) directions corresponding to different fields of view (0.00mm, 3.45mm, 5.75mm, 8.05mm, 10.53mm, and 11.50mm) directions as the spatial frequency increases. The ideal curve is a straight line coinciding with the system's diffraction limit, indicating that the geometric aberrations of the light rays at all positions are less than the wave phase aberration caused by the physical limitations of the system itself, and can be ignored. Figure 10It can be seen that the image quality of this industrial lens is higher than 0.4MTF at 180pl / mm from the center field of view to the edge field of view, and the imaging has excellent resolution.

[0103] Figure 11 yes Figure 7 The diagram shown illustrates the axial chromatic aberration of an industrial lens at its optimal object distance. Figure 11 As shown in the figure, the vertical direction represents the normalized 0-field pupil plane, where 0 represents the pupil center, and the vertical vertex represents the pupil vertex; the horizontal direction represents the axial chromatic aberration at different wavelengths (460nm, 530nm, 620nm), in millimeters (mm). Figure 11 It can be seen that the axial chromatic aberration of the entire pupil of the industrial lens is less than 35μm, and the image has excellent clarity.

[0104] Figure 12 yes Figure 7 The diagram shown illustrates the transverse chromatic aberration of an industrial lens at its optimal object distance, as follows: Figure 12 As shown in the diagram, the vertical direction represents the field of view angle, 0 represents the field of view angle incident parallel to the optical axis, and the vertex of the vertical direction represents the maximum half-field of view angle. Figure 12 It can be seen that at each wavelength (460nm, 530nm, 620nm), the transverse chromatic aberration from the center field of view to the edge field of view of the industrial lens is less than 0.7μm, resulting in higher imaging quality.

[0105] In yet another feasible embodiment, Figure 13 This is a schematic diagram of another industrial lens under optimal object distance provided by an embodiment of the present invention. Table 5 details another feasible implementation method. Figure 13 The specific optical and physical parameters of the industrial lens are shown.

[0106] Table 5. Another optical physical parameter design for industrial lenses.

[0107] Scope of protection Example 3 lower limit upper limit TTL / EFL 2.1962 2.1950 2.2300 TTL / DM 3.7738 3.5400 3.7800 EFL 52.6061 50.6500 52.6100 TTL 115.5340 112.9400 115.5400 DM 33.3162 31.7700 33.3200 FOV 21.1082 21.1000 22.4200 F.NO 2.3015 2.2100 2.3100 Vd5 / Vd4 2.4164 2.4100 3.8500 Vd5 / Vd6 1.6997 1.6900 3.6700 Φ4-6 / Φ7-8 -1.0883 -1.1500 -1.0800 Φ11 / Φ12 -0.7275 -0.8900 -0.7200 Φ2-7 / Φ8-10 -1.0270 -1.0300 -0.9100 DISG.MAX -0.0273％ -0.1000％ 0.0000％ ξ1 1.5157 1.1500 1.6800 Φ1 0.0159 0.0140 0.0160 Φ2 -0.0278 -0.0280 -0.0250 Φ3 0.0216 0.0210 0.0240 Φ4 -0.0414 -0.0470 -0.0410 Φ5 0.0352 0.0350 0.0380 Φ6 -0.0433 -0.0460 -0.0420 Φ4-6 -0.0508 -0.0570 -0.0500 Φ7 0.0211 0.0180 0.0220 Φ8 0.0269 0.0270 0.0300 Φ9 0.0338 0.0330 0.0420 Φ10 -0.0444 -0.0540 -0.0440 Φ9-10 -0.0045 -0.0040 -0.0070 Φ11 0.0117 0.0110 0.0180 Φ12 -0.0160 -0.0220 -0.0150

[0108] Table 6 shows the design parameters of the surface type, radius of curvature, thickness, and material of each lens in another type of industrial lens, corresponding to Table 5.

[0109] Table 6. Another parameter design for each lens in industrial lenses.

[0110]

[0111] The industrial lens of this embodiment includes a first lens 10, a first aperture 130, a second lens 20, a third lens 30, a fourth lens 40, a fifth lens 50, a sixth lens 60, a second aperture 140, a seventh lens 70, an eighth lens 80, a ninth lens 90, a tenth lens 100, an eleventh lens 110, a twelfth lens 120, and a filter glass 150, arranged sequentially along the optical axis from the object side to the image side. The surface numbering is based on the sequential order of the lenses, where "1" represents the object-side surface of the first lens 10, "2" represents the image-side surface of the first lens 10, and so on. "IMG" represents the image plane of the lens. The radius of curvature represents the curvature of the lens surface; a positive value indicates that the surface bends towards the image plane, and a negative value indicates that the surface bends towards the object plane. "Infinite" indicates that the surface is flat and the radius of curvature is infinite. The thickness represents the axial distance between the current surface and the next surface. The refractive index represents the ability of the material between the current surface and the next surface to deflect light; a space indicates that the current position is air and the refractive index is 1. The Abbe number represents the dispersion characteristics of the material between the current surface and the next surface; a space indicates that the current position is air. Half-aperture indicates half the aperture size of the current surface. In this embodiment, when the 20th surface spacing is 25.836mm, it can focus to an object distance of 200mm; when the 20th surface spacing is 12.016mm, it can focus to an object distance of 1000mm.

[0112] Figure 14 yes Figure 13 The diagram shown illustrates the light fan structure of an industrial lens at optimal object distance. The light fan diagram is one of the most commonly used evaluation methods in modern optical design. For example... Figure 14 As shown, the horizontal axis represents the beam aperture, and the vertical axis represents the transverse aberration. The ideal curve is a straight line coinciding with the horizontal axis, indicating that all rays converge at the same point on the image plane. The interval on the vertical axis of the curve corresponds to the maximum dispersion range of the beam on the ideal image plane. The fan diagram not only reflects monochromatic aberrations at different wavelengths (460nm, 530nm, 620nm) but also represents the magnitude of transverse chromatic aberration. Figure 14 It can be seen that the industrial lens closely approximates the horizontal axis at all wavelengths (460nm, 530nm, 620nm) in all fields of view, indicating that the transverse aberration of each wavelength in the optical system of the industrial lens is well corrected. At the same time, there is no obvious dispersion in each wavelength, indicating that the chromatic aberration of the system is also well corrected, thus ensuring that the optical system can achieve the high-resolution imaging requirements.

[0113] Figure 15 yes Figure 13 The diagram shown illustrates the field curvature distortion curve of an industrial lens at the optimal object distance, as follows: Figure 15As shown, in the coordinate system on the left side of the figure, the horizontal coordinate represents the magnitude of the field curvature, in mm; the vertical coordinate represents the normalized image height, which has no unit; where T represents the meridion and S represents the sagitta; from Figure 15 It can be seen that the lens provided in this embodiment effectively controls field curvature, meaning that during imaging, the difference in image quality between the center and the periphery is small, resulting in good consistency; in the coordinate system on the right, the horizontal axis represents the magnitude of distortion, expressed as a percentage; the vertical axis represents the normalized image height, which has no unit; from Figure 15 As can be seen, the distortion of the industrial lens provided in this embodiment has been well corrected, with optical distortion less than ±0.1%.

[0114] Figure 16 yes Figure 13 The diagram shows the MTF (Mean Transmission Function) of an industrial lens at the optimal object distance. The MTF is one of the most commonly used and authoritative evaluation methods in modern optical design. The horizontal axis represents the spatial frequency distribution of line pairs in object space as imaged onto the image plane by the optical system, in periods / mm. The vertical axis represents the magnitude of the optical transfer function. The diagram shows the trend of the optical transfer function along the meridional (T) and sagittal (S) directions corresponding to different fields of view (0.00mm, 3.45mm, 5.75mm, 8.05mm, 10.53mm, and 11.50mm) directions as the spatial frequency increases. The ideal curve is a straight line coinciding with the system's diffraction limit, indicating that the geometric aberrations of the light rays at all positions are less than the wave phase aberration caused by the physical limitations of the system itself, and can be ignored. Figure 16 It can be seen that the image quality of this industrial lens is higher than 0.4MTF at 180pl / mm from the center field of view to the edge field of view, and the imaging has excellent resolution.

[0115] Figure 17 yes Figure 13 The diagram shown illustrates the axial chromatic aberration of an industrial lens at its optimal object distance. Figure 17 As shown in the figure, the vertical direction represents the normalized 0-field pupil plane, where 0 represents the pupil center, and the vertical vertex represents the pupil vertex; the horizontal direction represents the axial chromatic aberration at different wavelengths (460nm, 530nm, 620nm), in millimeters (mm). Figure 17 It can be seen that the axial chromatic aberration of the entire pupil of the industrial lens is less than 20μm, and the image has excellent clarity.

[0116] Figure 18 yes Figure 13 The diagram shown illustrates the transverse chromatic aberration of an industrial lens at its optimal object distance, as follows: Figure 18 As shown in the diagram, the vertical direction represents the field of view angle, 0 represents the field of view angle incident parallel to the optical axis, and the vertex of the vertical direction represents the maximum half-field of view angle. Figure 18It can be seen that at various wavelengths (460nm, 530nm, 620nm), the transverse chromatic aberration from the center field of view to the edge field of view of the industrial lens is less than 0.6μm, resulting in higher imaging quality.

[0117] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. An industrial lens, characterized in that, include: A focusing lens group and a fixed lens group are arranged sequentially along the optical axis from the object side to the image side; the focusing lens group moves along the optical axis to focus; The focusing lens group includes a first lens with positive optical power, a second lens with negative optical power, a third lens with positive optical power, a fourth lens with negative optical power, a fifth lens with positive optical power, a sixth lens with negative optical power, a seventh lens with positive optical power, an eighth lens with positive optical power, a ninth lens with positive optical power, and a tenth lens with negative optical power, arranged sequentially along the optical axis from the object side to the image side. The fixed lens group includes an eleventh lens with positive optical power and a twelfth lens with negative optical power arranged sequentially along the optical axis from the object side to the image side. Wherein, the first lens to the twelfth lens are all glass lenses; the total number of lenses in the focusing lens group and the fixed lens group is 12; The maximum optical distortion DISG.MAX of the industrial lens satisfies: |DISG.MAX|≤0.1000%; The overall focal length (EFL) of the industrial lens satisfies: 2.1950 ≤ TTL / EFL ≤ 2.2300; where TTL is the distance from the front end of the first lens to the image plane of the industrial lens. The total optical power Φ4-6 of the fourth to sixth lenses and the total optical power Φ7-8 of the seventh to eighth lenses satisfy: -1.1500≤Φ4-6 / Φ7-8≤-1.0800; The total optical power Φ2-7 of the second to the seventh lenses and the total optical power Φ8-10 of the eighth to the tenth lenses satisfy: -1.0300≤Φ2-7 / Φ8-10≤-0.9100; The first lens has a convex object-side surface and a concave image-side surface; the second lens has both a concave object-side surface and an image-side surface; the third lens has both a convex object-side surface and an image-side surface; the fourth lens has both a concave object-side surface and an image-side surface; the fifth lens has both a convex object-side surface and an image-side surface; the sixth lens has both a concave object-side surface and an image-side surface; the seventh lens has a concave object-side surface and a convex image-side surface; the eighth lens has both a convex object-side surface and an image-side surface; the ninth lens has both a convex object-side surface and an image-side surface; the tenth lens has both a concave object-side surface and an image-side surface; the eleventh lens has both a convex object-side surface and an image-side surface; and the twelfth lens has both a concave object-side surface and an image-side surface.

2. The industrial lens according to claim 1, characterized in that, The Abbe number Vd4 of the fourth lens and the Abbe number Vd5 of the fifth lens satisfy: 2.4100≤Vd5 / Vd4.

3. The industrial lens according to claim 1, characterized in that, The Abbe number Vd5 of the fifth lens and the Abbe number Vd6 of the sixth lens satisfy: 1.6900≤Vd5 / Vd6.

4. The industrial lens according to claim 1, characterized in that, The optical power Φ11 of the eleventh lens and the optical power Φ12 of the twelfth lens satisfy the following condition: -0.8900≤Φ11 / Φ12≤-0.7200.

5. The industrial lens according to claim 1, characterized in that, The maximum effective aperture DM among the effective apertures of the first lens to the twelfth lens satisfies: 3.5400≤TTL / DM≤3.7800; Wherein, TTL is the distance from the front end of the first lens to the image plane of the industrial lens.

6. The industrial lens according to claim 1, characterized in that, The field of view (FOV) of the industrial lens satisfies: FOV ≥ 21.1000°; and / or, The aperture number F.NO of the industrial lens satisfies: F.NO≤2.3100.

Images