Industrial lenses

Abstract

This invention relates to an industrial lens, comprising, along the optical axis from the object side to the image side, a first lens group with positive optical power, a second lens group with negative optical power, and a third lens group with positive optical power. The first and third lens groups are fixed lens groups, and the second lens group is a focusing group. The first 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, and a fifth lens with positive optical power. The second lens group includes a sixth lens with positive optical power and a seventh lens with negative optical power. The third lens group includes an eighth and a ninth lens with opposite optical power, a tenth lens with positive optical power, and an eleventh lens with negative optical power. The industrial lens of this invention possesses at least one of the following characteristics: low distortion, high illumination, high resolution, wide focusing distance range, and no defocusing within a temperature range of -40℃ to +80℃.

Description

Technical Field

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

[0002] Industrial lenses are an indispensable component of machine vision systems, playing a crucial role in applications such as automated inspection, quality control, measurement, and identification.

[0003] With the upgrading and progress of social industrial production, the requirements for the quality of industrial lenses are gradually increasing. Currently, existing industrial lenses have the following shortcomings, or only meet certain requirements:

[0004] 1. The lens has significant optical distortion, resulting in large distortions at the four corners of the image, which affects the resolution of objects.

[0005] 2. Insufficient illumination results in a dark image and low color saturation;

[0006] 3. Poor image quality, blurry picture, which interferes with object recognition;

[0007] 4. The actual shooting distance range is narrow, which cannot meet the usage needs in complex environments;

[0008] 5. The lens is greatly affected by high and low temperature environments, which can easily cause unclear images.

[0009] Therefore, designing an industrial lens that meets at least one of the following characteristics—low distortion, high illumination, high resolution, wide focusing distance range, and no blurring within a temperature range of -40℃ to +80℃—has become a market trend. Summary of the Invention

[0010] To address the problems existing in the prior art, the present invention aims to provide an industrial lens that has at least one of the following characteristics: low distortion, high illumination, high resolution, wide focusing distance range, and no defocusing within a temperature range of -40℃ to +80℃.

[0011] To achieve the above-mentioned objective, the present invention provides an industrial lens, which, along the optical axis from the object side to the image side, sequentially includes: a first lens group with positive optical power, a second lens group with negative optical power, and a third lens group with positive optical power. The first lens group and the third lens group are fixed lens groups, and the second lens group is a focusing group that moves along the optical axis of the industrial lens.

[0012] The first lens group includes, in sequence, 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, and a fifth lens with positive optical power, for a total of five lenses.

[0013] The second lens group includes, in sequence, a sixth lens with positive optical power and a seventh lens with negative optical power, for a total of two lenses;

[0014] The third lens group includes, in sequence, an eighth lens, a ninth lens, a tenth lens with positive optical power, and an eleventh lens with negative optical power, for a total of four lenses; the optical powers of the eighth lens and the ninth lens are opposite.

[0015] According to one technical solution of the present invention, the object side of the first lens is convex, the second lens is a concave-concave lens, the third lens is a convex-convex lens, the fourth lens is a concave-concave lens, and the fifth lens is a convex-convex lens.

[0016] According to one technical solution of the present invention, the image-side surface of the sixth lens is convex; the seventh lens is a concave-concave lens.

[0017] According to one technical solution of the present invention, the eighth lens is a convex-convex lens or a convex-concave lens, the ninth lens is a concave-concave lens or a convex-concave lens, the tenth lens is a convex-convex lens, and the eleventh lens is a concave-concave lens.

[0018] According to one technical solution of the present invention, the third lens, the fourth lens and the fifth lens form a set of cemented triplet lenses, and the sixth lens and the seventh lens form a set of cemented doublet lenses.

[0019] According to one technical solution of the present invention, the eighth lens, the ninth lens, the tenth lens, and the eleventh lens are combined to form two sets of cemented doublet lenses.

[0020] Alternatively, the ninth lens, the tenth lens, and the eleventh lens can be combined to form a set of cemented triode lenses.

[0021] Alternatively, the eighth lens, the ninth lens, the tenth lens, and the eleventh lens can be combined to form a set of four-colloidal lenses.

[0022] According to one technical solution of the present invention, the total optical system length TTL of the industrial lens and the total effective focal length FI of the industrial lens at an object distance of 0.3m satisfy the following relationship: 2.0≤TTL / FI≤2.2.

[0023] According to one technical solution of the present invention, the total optical system length (TTL) of the industrial lens and the back focal length (BFL) of the industrial lens satisfy the following relationship: 3.1≤TTL / BFL≤3.5.

[0024] According to one technical solution of the present invention, the effective focal length FG1 of the first lens group and the total effective focal length FI of the industrial lens at an object distance of 0.3m satisfy the following relationship: 1.0≤FG1 / FI≤1.7.

[0025] According to one technical solution of the present invention, the effective focal length FG2 of the second lens group and the total effective focal length FI of the industrial lens at an object distance of 0.3m satisfy the following relationship: -2.2≤FG2 / FI≤-0.7.

[0026] According to one technical solution of the present invention, the effective focal length FG3 of the third lens group and the total effective focal length FI of the industrial lens at an object distance of 0.3m satisfy the following relationship: 0.7≤FG3 / FI≤1.1.

[0027] According to one technical solution of the present invention, the total effective focal length FI of the industrial lens at an object distance of 0.3m and the total effective focal length FII of the industrial lens at an object distance of infinity satisfy the following relationship: 0.97≤FI / FII≤1.13.

[0028] According to one technical solution of the present invention, the effective focal length F1 of the first lens and the effective focal length FG1 of the first lens group satisfy the following relationship: 0.6≤F1 / FG1≤1.1.

[0029] According to one technical solution of the present invention, the effective focal length F2 of the second lens and the effective focal length FG1 of the first lens group satisfy the following relationship: -0.9≤F2 / FG1≤-0.19.

[0030] According to one technical solution of the present invention, the effective focal length Fa of the cemented triplet lens composed of the third lens to the fifth lens satisfies the following relationship with the effective focal length FG1 of the first lens group: 0.37≤Fa / FG1≤0.91.

[0031] According to one technical solution of the present invention, the air gap distance d23 between the second lens and the third lens on the optical axis and the effective focal length FG1 of the first lens group satisfy the following relationship: 0.06≤d23 / FG1≤0.45.

[0032] According to one technical solution of the present invention, the effective focal length F6 of the sixth lens and the effective focal length FG2 of the second lens group satisfy the following relationship: -1.4≤F6 / FG2≤-0.5.

[0033] According to one technical solution of the present invention, the effective focal length F7 of the seventh lens and the effective focal length FG2 of the second lens group satisfy the following relationship: 0.3≤F7 / FG2≤0.7.

[0034] According to one technical solution of the present invention, the focusing movement distance value d_G2 of the second lens group within the object distance variation range and the total effective focal length FI of the industrial lens at an object distance of 0.3m satisfy the following relationship: 0.14≤d_G2 / FI≤0.5.

[0035] According to one technical solution of the present invention, the effective focal length F8 of the eighth lens and the effective focal length F9 of the ninth lens satisfy the following relationship: -1.6≤F8 / F9≤-0.5.

[0036] According to one technical solution of the present invention, the effective focal length F10 of the tenth lens and the effective focal length FG3 of the third lens group satisfy the following relationship: 0.2≤F10 / FG3≤0.4.

[0037] According to one technical solution of the present invention, the effective focal length F11 of the eleventh lens and the effective focal length FG3 of the third lens group satisfy the following relationship: -0.6≤F11 / FG3≤-0.3.

[0038] According to one technical solution of the present invention, the effective focal length F8 of the eighth lens, the effective focal length F9 of the ninth lens, the effective focal length F10 of the tenth lens, the effective focal length F11 of the eleventh lens and the effective focal length FG3 of the third lens group satisfy the following relationship: -0.3≤(F8+F9+F10+F11) / FG3≤1.0.

[0039] According to one technical solution of the present invention, the refractive index value Nd3 of the third lens under d light and the center thickness value t3 of the third lens satisfy the following relationship: 0.3≤Nd3 / t3≤0.7.

[0040] According to one technical solution of the present invention, the Abbe number Vd6 of the sixth lens, the Abbe number Vd7 of the seventh lens, and the total effective focal length FI of the industrial lens at an object distance of 0.3m satisfy the following relationship: 0.2≤|Vd7-Vd6| / FI≤0.7.

[0041] According to one technical solution of the present invention, the Abbe number Vd10 of the tenth lens, the Abbe number Vd11 of the eleventh lens, and the total effective focal length FI of the industrial lens at an object distance of 0.3m satisfy the following relationship: 0.5≤|Vd10-Vd11| / FI≤1.2.

[0042] According to one technical solution of the present invention, the total optical system length TTL of the industrial lens and the maximum effective aperture D_max of the lenses from the first lens to the eleventh lens satisfy the following relationship: 4.34≤TTL / D_max≤5.46.

[0043] According to one technical solution of the present invention, the industrial lens satisfies at least one of the following conditions:

[0044] 2.02≤TTL / FI≤2.19

[0045] 3.14≤TTL / BFL≤3.45

[0046] 1.10≤FG1 / FI≤1.66,

[0047] -1.98≤FG2 / FI≤-0.86,

[0048] 0.71≤FG3 / FI≤1.09

[0049] 1.00≤FI / FII≤1.10,

[0050] 0.63≤F1 / FG1≤1.01,

[0051] -0.78≤F2 / FG1≤-0.23,

[0052] 0.40≤Fa / FG1≤0.89,

[0053] 0.06≤d23 / FG1≤0.43,

[0054] -1.32≤F6 / FG2≤-0.58,

[0055] 0.33≤F7 / FG2≤0.63

[0056] 0.14≤d_G2 / FI≤0.49,

[0057] -1.46≤F8 / F9≤-0.64,

[0058] 0.20≤F10 / FG3≤0.38

[0059] -0.60≤F11 / FG3≤-0.32,

[0060] -0.19≤(F8+F9+F10+F11) / FG3≤0.90,

[0061] 0.32≤Nd3 / t3≤0.66,

[0062] 0.23≤|Vd7-Vd6| / FI≤0.66,

[0063] 0.56≤|Vd10-Vd11| / FI≤1.09,

[0064] 4.44≤TTL / D_max≤5.35

[0065] Wherein, TTL is the total length of the optical system of the industrial lens; FI is the focal length of the industrial lens at an object distance of 0.3m; BFL is the back focal length of the industrial lens; FG1 is the focal length of the first lens group; FG2 is the focal length of the second lens group; FG3 is the focal length of the third lens group; FII is the focal length of the industrial lens at an object distance of infinity; F1 is the focal length of the first lens; F2 is the focal length of the second lens; Fa is the focal length of the cemented triplet lens composed of the third to fifth lenses; d23 is the air gap distance between the second lens and the third lens on the optical axis; F6 is the focal length of the sixth lens; F 7 is the focal length of the seventh lens; d_G2 is the focusing distance of the second lens group within the range of object distance variation; F8 is the focal length of the eighth lens; F9 is the focal length of the ninth lens; F10 is the focal length of the tenth lens; F11 is the focal length of the eleventh lens; Nd3 is the refractive index of the third lens under d light; t3 is the center thickness of the third lens; Vd6 is the Abbe number of the sixth lens; Vd7 is the Abbe number of the seventh lens; Vd10 is the Abbe number of the tenth lens; Vd11 is the Abbe number of the eleventh lens; D_max is the maximum effective aperture of the lens from the first lens to the eleventh lens.

[0066] According to the present invention, by setting the number and optical power of industrial lenses, the ultra-wide-angle lens achieves at least one of the following beneficial effects: low distortion (absolute optical distortion ≤ 1.1%), high illumination (RI ≥ 70%), miniaturization (TTL ≤ 85mm), aperture located at the end of the system, constant aperture (FN0 = 3.0), clear resolution at object distances from 0.3m to infinity, no blurring in the temperature range of -40℃ to +80℃, and normal operation in various high and low temperature environments. Attached Figure Description

[0067] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly described below. Obviously, the drawings described below are merely some embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without creative effort.

[0068] Figure 1 This is a schematic diagram of the structure of the industrial lens in Embodiment 1 of the present invention;

[0069] Figure 2 This is a schematic diagram of distortion of the industrial lens in Embodiment 1 of the present invention when the object distance is 0.3m;

[0070] Figure 3This is a schematic diagram of distortion in the industrial lens of Embodiment 1 of the present invention when the object distance is infinity;

[0071] Figure 4 This is a schematic diagram of the structure of the industrial lens in Embodiment 2 of the present invention;

[0072] Figure 5 This is a schematic diagram of distortion of the industrial lens in Embodiment 2 of the present invention when the object distance is 0.3m;

[0073] Figure 6 This is a schematic diagram of distortion in the industrial lens of Embodiment 2 of the present invention when the object distance is infinity;

[0074] Figure 7 This is a schematic diagram of the structure of the industrial lens in Embodiment 3 of the present invention;

[0075] Figure 8 This is a schematic diagram of distortion of the industrial lens in Embodiment 3 of the present invention when the object distance is 0.3m;

[0076] Figure 9 This is a schematic diagram of distortion in the industrial lens of Embodiment 3 of the present invention when the object distance is infinity;

[0077] Figure 10 This is a schematic diagram of the structure of the industrial lens in Embodiment 4 of the present invention;

[0078] Figure 11 This is a schematic diagram of distortion of the industrial lens in Embodiment 4 of the present invention when the object distance is 0.3m;

[0079] Figure 12 This is a schematic diagram of distortion when the object distance of the industrial lens in Embodiment 4 of the present invention is infinity. Detailed Implementation

[0080] To better understand this application, various aspects of this application will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed descriptions are merely illustrative of exemplary embodiments of this application and are not intended to limit the scope of this application in any way. Throughout the specification, the same reference numerals refer to the same elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0081] It should be noted that in this specification, the terms "first," "second," "third," etc., are used only to distinguish one feature from another and do not imply any limitation on the features. Therefore, without departing from the teachings of this application, the first lens discussed below may also be referred to as the second lens or the first lens.

[0082] In the accompanying drawings, the thickness, size, and shape of the lenses have been slightly exaggerated for ease of illustration. Specifically, the shapes of the spherical or aspherical surfaces shown in the drawings are illustrated by way of example. That is, the shapes of the spherical or aspherical surfaces are not limited to those shown in the drawings. The drawings are for illustrative purposes only and are not strictly to scale.

[0083] In this article, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the location of the convexity is not defined, it means that the lens surface is convex at least in the paraxial region; if the lens surface is concave and the location of the concaveness is not defined, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the subject is called the object-side surface of the lens, and the surface of each lens closest to the imaging plane is called the image-side surface of the lens.

[0084] It should also be understood that the terms "comprising," "including," "having," "containing," and / or "comprising," when used in this specification, indicate the presence of the stated features, elements, and / or components, but do not exclude the presence or addition of one or more other features, elements, components, and / or combinations thereof. Furthermore, when expressions such as "at least one of..." appear after a list of listed features, they modify the entire list of features, not individual elements in the list. Additionally, when describing embodiments of this application, the word "may" is used to mean "one or more embodiments of this application." And the term "exemplary" is intended to refer to an example or illustration.

[0085] Unless otherwise specified, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. It should also be understood that terms (e.g., those defined in common dictionaries) shall be interpreted as having the meaning consistent with their meaning in the context of the relevant art and shall not be interpreted in an idealized or overly formalized sense, unless expressly so specified herein.

[0086] It should be noted that, unless otherwise specified, the embodiments and features described in the embodiments of this application can be combined with each other. The following embodiments only illustrate several implementation methods of this application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the patent application. It should be pointed out that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of this application, and these all fall within the protection scope of this application.

[0087] like Figures 1 to 12As shown, an embodiment of the present invention provides an industrial lens, which, along the optical axis from the object side to the image side, sequentially includes: a first lens group G1 with positive optical power, a second lens group G2 with negative optical power, a third lens group G3 with positive optical power, a parallel plate CG, and an image plane IMA. The first lens group G1 and the third lens group are fixed lens groups, and the second lens group G2 is a focusing group that moves along the optical axis of the industrial lens.

[0088] Among them, the first lens group G1 is a fixed front group, whose position relative to the image plane is fixed during the change of object distance. The optical power of the first lens group G1 is positive, which is conducive to converging the incident light rays and reducing the aperture of the rear lens. It is also conducive to correcting system aberrations and distortions, while reducing tolerance sensitivity and ensuring the uniformity of the image.

[0089] The second lens group G2 is a focusing group, and its optical power is negative, which can smooth the light path. At the same time, by moving the position of the second lens group G2 on the optical axis, the lens can focus from an object distance of 0.3m to infinity, ensuring clear imaging at different object distances.

[0090] The third lens group G3 is a fixed rear group, with a fixed relative image plane. The optical power of the third lens group G3 is positive, which can ensure a constant aperture, smooth out emitted light, reduce astigmatism and field curvature changes during focusing, reduce system sensitivity, and ensure production yield.

[0091] In this embodiment of the invention, along the optical axis from the object side to the image side, the first lens group G1 sequentially includes: a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, and a fifth lens L5, for a total of five lenses.

[0092] The object side of the first lens L1 is convex and has positive optical power, which is beneficial for converging incident light rays and can reduce distortion.

[0093] The second lens L2 is a concave lens with negative optical power, which can smooth the path of light after passing through the L1 lens. When paired with the first lens L1, which has positive optical power, it helps to reduce spherical aberration.

[0094] The third lens L3 is a convex-convex lens with positive optical power. It uses a high-refractive-index material, which can reduce the height of light rays and facilitates miniaturization.

[0095] The fourth lens L4 is a concave-concave lens with negative optical power, and the fifth lens L5 is a convex-convex lens with positive optical power. Together with the third lens L3, they can form a positive-negative-positive structure. By using appropriate lens materials, the chromatic aberration of the system can be balanced, which is beneficial to improving the image quality.

[0096] In this embodiment of the invention, the third lens L3, the fourth lens L4, and the fifth lens L5 can be combined into a cemented triplet lens, which effectively reduces the tolerance sensitivity of the optical system and improves the production yield.

[0097] In this embodiment of the invention, along the optical axis from the object side to the image side, the second lens group G2 sequentially includes a sixth lens L6 and a seventh lens L7, for a total of two lenses;

[0098] The image side of the sixth lens L6 is convex and has positive optical power. The sixth lens L6 can be made of high refractive material to collect the outgoing light rays of the first lens group G1, control the light ray trajectory, and at the same time help reduce the field curvature of the system at different object distances and improve the lens resolution.

[0099] The seventh lens, L7, is a concave-convex lens with negative optical power. It is paired with the sixth lens, L6, to correct spherical aberration, balance system chromatic aberration, and ensure imaging performance at different object distances.

[0100] In this embodiment of the invention, the sixth lens L6 and the seventh lens L7 can cooperate to form a cemented doublet lens group, thereby effectively reducing the tolerance sensitivity of the optical system and improving the production yield.

[0101] In this embodiment of the invention, the third lens group G3 includes, in sequence, an eighth lens L8, a ninth lens L9, a tenth lens L10, and an eleventh lens L11, for a total of four lenses.

[0102] The eighth lens L8 and the ninth lens L9 have opposite optical powers, which can achieve complementarity between positive and negative spherical aberration, reduce system aberrations, and facilitate clear imaging.

[0103] The tenth lens, L10, is a convex-convex lens with positive optical power, which can effectively balance the astigmatism and distortion introduced by the front group.

[0104] The object side of the eleventh lens L11 is concave and has negative optical power. When cemented together with the tenth lens L10, it helps to reduce chromatic aberration generated by the front lens group and balance system aberrations.

[0105] In this embodiment of the invention, the eighth lens L8, the ninth lens L9, the tenth lens L10, and the eleventh lens L11 can be combined into a set of four-cemented lenses, or a single lens and a set of three-cemented lenses, or two sets of two-cemented lenses. This can effectively balance the chromatic aberration of the system, reduce tolerance sensitivity, and ensure the imaging quality of different object distances under a constant aperture.

[0106] This invention ensures that the lens maintains a constant aperture throughout the process of varying object distances from 0.3m to infinity, thereby stabilizing the image quality and meeting the needs of various scenarios.

[0107] The present invention employs three lens groups: fixed, focusing, and fixed, which are also positive, negative, and positive optical power combinations. This is beneficial for correcting field curvature and distortion at different object distances from 0.3m to infinity, eliminating system chromatic aberration, reducing tolerance sensitivity, and ensuring clear imaging at different object distances.

[0108] In some embodiments of the present invention, the first lens L1 to the eleventh lens L11 are all made of glass. The use of glass for all lens elements reduces the likelihood of significant changes in lens size, refractive index, and surface shape due to temperature variations in high and low temperature environments. This improves system stability, facilitates heatless operation, and ensures the lens remains focused within a temperature range of -40℃ to 80℃, guaranteeing a clear image. Simultaneously, the glass material effectively corrects chromatic aberration, ensuring lens quality.

[0109] In some embodiments of the present invention, the total optical system length (TTL) of the industrial lens and the total effective focal length (FI) of the industrial lens at an object distance of 0.3m satisfy the following relationship: 2.0 ≤ TTL / FI ≤ 2.2, preferably, 2.02 ≤ TTL / FI ≤ 2.19. Under a given system focal length, controlling the total optical system length makes the total optical system length smaller, which is beneficial for miniaturization.

[0110] In some embodiments of the present invention, the total optical system length (TTL) of the industrial lens and the back focal length (i.e., the on-axis distance from the image side of the last lens to the imaging plane) (BFL) of the industrial lens satisfy the following relationship: 3.1 ≤ TTL / BFL ≤ 3.5, preferably, 3.14 ≤ TTL / BFL ≤ 3.45. Based on miniaturization, by controlling the back focal length of the system's optical system, the back focal length of the lens is made longer, which helps to reserve space for the installation of optical components, facilitates the assembly of the industrial lens, avoids interference, and improves the assembly yield of the industrial lens.

[0111] In some embodiments of the present invention, the effective focal length FG1 of the first lens group G1 and the total effective focal length FI of the industrial lens at an object distance of 0.3m satisfy the following relationship: 1.0≤FG1 / FI≤1.7, preferably, 1.10≤FG1 / FI≤1.66. Reasonably controlling the ratio of the effective focal length of the first lens group G1 to the effective focal length of the optical system at an object distance of 0.3m is beneficial for converging incident light rays into the optical system, effectively controlling the light path, correcting system aberrations and distortions, reducing tolerance sensitivity, and improving the imaging quality of the lens.

[0112] In some embodiments of the present invention, the effective focal length FG2 of the second lens group G2 and the total effective focal length FI of the industrial lens at an object distance of 0.3m satisfy the following relationship: -2.2≤FG2 / FI≤-0.7, preferably -1.98≤FG2 / FI≤-0.86. By reasonably controlling the ratio of the effective focal length of the second lens group G2 to the effective focal length of the optical system at an object distance of 0.3m, focusing of the lens can be achieved at object distances from 0.3m to infinity, ensuring clear imaging at different object distances.

[0113] In some embodiments of the present invention, the effective focal length FG3 of the third lens group G3 and the total effective focal length FI of the industrial lens at an object distance of 0.3m satisfy the following relationship: 0.7≤FG3 / FI≤1.1, preferably, 0.71≤FG3 / FI≤1.09. Reasonably controlling the ratio of the effective focal length of the third lens group G3 to the effective focal length of the optical system at an object distance of 0.3m smoothly emits light, allowing the light to transition smoothly onto the image plane. This helps reduce astigmatism and field curvature aberrations on the image plane, improves image quality, and effectively compensates for on-axis chromatic aberration of the front-end group, ensuring the quality of the image.

[0114] In some embodiments of the present invention, the total effective focal length FI of the industrial lens at an object distance of 0.3m and the total effective focal length FII of the industrial lens at an object distance of infinity satisfy the following relationship: 0.97 ≤ FI / FII ≤ 1.13, preferably 1.00 ≤ FI / FII ≤ 1.10. By reasonably controlling the ratio of the effective focal length of the optical system at object distances of 0.3m and infinity, the impact of lens changes on the image quality can be effectively reduced, meeting the requirements for a wider range of working distances.

[0115] In some embodiments of the present invention, the effective focal length F1 of the first lens L1 and the effective focal length FG1 of the first lens group G1 satisfy the following relationship: 0.6 ≤ F1 / FG1 ≤ 1.1, preferably, 0.63 ≤ F1 / FG1 ≤ 1.01. Reasonably controlling the ratio of the effective focal length of the first lens L1 to the effective focal length of the first lens group G1 is beneficial for converging incident light rays and reducing distortion.

[0116] In some embodiments of the present invention, the effective focal length F2 of the second lens L2 and the effective focal length FG1 of the first lens group G1 satisfy the following relationship: -0.9 ≤ F2 / FG1 ≤ -0.19, preferably -0.78 ≤ F2 / FG1 ≤ -0.23. By reasonably controlling the ratio of the effective focal length of the second lens L2 to the effective focal length of the first lens group G1, the path of light passing through the first lens L1 is smoothed. Combined with the positive lens of the first lens L1, this helps to reduce spherical aberration.

[0117] In some embodiments of the present invention, the effective focal length Fa of the cemented triplet lens composed of the third lens L3 to the fifth lens L5 satisfies the following relationship with the effective focal length FG1 of the first lens group G1: 0.37≤Fa / FG1≤0.91, preferably, 0.40≤Fa / FG1≤0.89. Reasonably controlling the ratio of the effective focal length of the cemented triplet lens in the first lens group G1 to the effective focal length of the first lens group G1 can effectively reduce system chromatic aberration and effectively balance system spherical aberration, improving resolution; at the same time, it can reduce the tolerance sensitivity between lenses, which is beneficial to improving production yield.

[0118] In some embodiments of the present invention, the air gap distance d23 between the second lens L2 and the third lens L3 on the optical axis satisfies the following relationship with the effective focal length FG1 of the first lens group G1: 0.06 ≤ d23 / FG1 ≤ 0.45, preferably 0.06 ≤ d23 / FG1 ≤ 0.43. Reasonably controlling the air gap distance between the second lens L2 and the third lens L3 on the optical axis in the first lens group can effectively control the direction of light, reduce the deflection angle of light entering the object side of the third lens L3, which helps to reduce light energy loss, improve illumination, and simultaneously reduce the tolerance sensitivity of the third lens L3, thus improving production yield.

[0119] In some embodiments of the present invention, the effective focal length F6 of the sixth lens L6 and the effective focal length FG2 of the second lens group G2 satisfy the following relationship: -1.4 ≤ F6 / FG2 ≤ -0.5, preferably -1.32 ≤ F6 / FG2 ≤ -0.58. Reasonably controlling the ratio of the effective focal length of the sixth lens L6 to the effective focal length of the second lens group G2, collecting the emitted light from the first lens group G1, and controlling the light trajectory are beneficial for high illumination and also help reduce field curvature at different object distances, thereby improving lens resolution.

[0120] In some embodiments of the present invention, the effective focal length F7 of the seventh lens L7 and the effective focal length FG2 of the second lens group G2 satisfy the following relationship: 0.3 ≤ F7 / FG2 ≤ 0.7, preferably, 0.33 ≤ F7 / FG2 ≤ 0.63. Reasonably controlling the ratio of the effective focal length of the seventh lens L7 to the effective focal length of the second lens group G2 is beneficial for correcting the spherical aberration generated by the sixth lens L6, balancing the chromatic aberration of the system, and ensuring imaging performance at different object distances.

[0121] In some embodiments of the present invention, the focusing distance d_G2 of the second lens group G2 within the object distance variation range and the total effective focal length FI of the industrial lens at an object distance of 0.3m satisfy the following relationship: 0.14≤d_G2 / FI≤0.5, preferably, 0.14≤d_G2 / FI≤0.49. Reasonably controlling the ratio of the focusing distance of the second lens group G2 within the object distance variation range to the effective focal length of the optical system at an object distance of 0.3m ensures that the focusing distance remains within a certain range, which is beneficial to the stability of the system during focusing, improves the focusing response speed of the lens, and guarantees the imaging quality at different object distances.

[0122] In some embodiments of the present invention, the effective focal length F8 of the eighth lens L8 and the effective focal length F9 of the ninth lens L9 satisfy the following relationship: -1.6 ≤ F8 / F9 ≤ -0.5, preferably -1.46 ≤ F8 / F9 ≤ -0.64. By reasonably controlling the ratio of the effective focal length of the eighth lens L8 to the effective focal length of the ninth lens L9, while always ensuring that the ratio is negative (i.e., the effective focal lengths of the eighth lens L8 and the ninth lens L9 are opposite in sign), the complementary nature of positive and negative spherical aberrations can be achieved, reducing system aberrations and promoting clear imaging.

[0123] In some embodiments of the present invention, the effective focal length F10 of the tenth lens L10 and the effective focal length FG3 of the third lens group G3 satisfy the following relationship: 0.2 ≤ F10 / FG3 ≤ 0.4, preferably, 0.20 ≤ F10 / FG3 ≤ 0.38. Reasonably controlling the ratio of the effective focal length of the tenth lens L10 to the effective focal length of the third lens group G3 can effectively balance the astigmatism and distortion introduced by the previous group, reduce field curvature on the image plane, and improve image quality.

[0124] In some embodiments of the present invention, the effective focal length F11 of the eleventh lens L11 and the effective focal length FG3 of the third lens group G3 satisfy the following relationship: -0.6 ≤ F11 / FG3 ≤ -0.3, preferably -0.60 ≤ F11 / FG3 ≤ -0.32. Reasonably controlling the ratio of the effective focal length of the eleventh lens L11 to the effective focal length of the third lens group G3 is beneficial for balancing the chromatic aberration generated by the positive lens of the tenth lens L10 and reducing system aberrations.

[0125] In some embodiments of the present invention, the effective focal lengths F8 of the eighth lens L8, F9 of the ninth lens L9, F10 of the tenth lens L10, and F11 of the eleventh lens L11 satisfy the following relationship with the effective focal length FG3 of the third lens group G3: -0.3≤(F8+F9+F10+F11) / FG3≤1.0, preferably -0.19≤(F8+F9+F10+F11) / FG3≤0.90. Reasonably setting the optical power of the eighth lens L8, ninth lens L9, tenth lens L10, and eleventh lens L11 is beneficial for mutual compensation of positive and negative spherical aberrations, while correcting astigmatism and field curvature of the system, improving lens resolution; at the same time, it effectively controls the light path, making the light transition smooth, effectively reducing the tolerance sensitivity of the fixed rear group, and improving production yield.

[0126] In some embodiments of the present invention, the refractive index value Nd3 of the third lens L3 under d-ray and the center thickness value t3 of the third lens L3 satisfy the following relationship: 0.3≤Nd3 / t3≤0.7, preferably, 0.32≤Nd3 / t3≤0.66. Reasonably controlling the ratio of the refractive index to the center thickness of the third lens L3 ensures that the third lens L3 has a large refractive index value, converging the emitted light from the second lens L2. This helps to ensure the optical system remains insensitive within a range of changes in ambient temperature and object distance, achieving lens heatlessness and making it suitable for high and low temperature environments.

[0127] In some embodiments of the present invention, the Abbe number Vd6 of the sixth lens L6 and the Abbe number Vd7 of the seventh lens L7 satisfy the following relationship with the total effective focal length FI of the industrial lens at an object distance of 0.3m: 0.2≤|Vd7-Vd6| / FI≤0.7, preferably, 0.23≤|Vd7-Vd6| / FI≤0.66. By reasonably controlling the ratio of the Abbe number difference between the seventh lens L7 and the sixth lens L6 to the effective focal length of the optical system at an object distance of 0.3m, and by using materials with different dispersion coefficients, dispersion can be mutually compensated, achieving the purpose of eliminating positional chromatic aberration, which is beneficial to improving the imaging performance of telephoto lenses; at the same time, it can also effectively reduce the tolerance sensitivity of the optical system and improve the production yield of the lens.

[0128] In some embodiments of the present invention, the Abbe number Vd10 of the tenth lens L10 and the Abbe number Vd11 of the eleventh lens L11 satisfy the following relationship with the total effective focal length FI of the industrial lens at an object distance of 0.3m: 0.5≤|Vd10-Vd11| / FI≤1.2, preferably, 0.56≤|Vd10-Vd11| / FI≤1.09. Reasonably controlling the ratio of the Abbe number difference between the tenth lens L10 and the eleventh lens L11 to the effective focal length of the optical system at an object distance of 0.3m, and using materials with different dispersion coefficients, is beneficial for reducing chromatic aberration generated by the front lens group and balancing system aberrations.

[0129] In some embodiments of the present invention, the total optical system length (TTL) of the industrial lens and the maximum effective aperture (D_max) of the lenses from the first lens L1 to the eleventh lens L11 satisfy the following relationship: 4.34 ≤ TTL / D_max ≤ 5.46, preferably, 4.44 ≤ TTL / D_max ≤ 5.35. By reasonably setting the ratio of the total optical system length to the maximum effective aperture of the first to eleventh lenses, the maximum effective aperture and the total optical system length can be reasonably constrained and controlled, which is beneficial for achieving lens miniaturization.

[0130] The following describes four specific embodiments of the industrial lens according to the present invention, based on the above-described configuration. The industrial lens according to the present invention comprises eleven lenses, with each cemented surface of the cemented lens designated as one surface, plus the aperture stop STO, protective glass CG, and image plane IMA, totaling 20 or 21 surfaces. The aperture stop STO is located behind the image-side surface of the eleventh lens L11. For ease of description, the lens surfaces, aperture stop STO, and protective glass CG are numbered S1, S2 to S20 or S1, S2 to S21.

[0131] The data for the four sets of examples are shown in Table 1 below:

[0132]

[0133]

[0134] Table 1

[0135] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. The embodiments cannot be described in detail here, but the embodiments of the present invention are not limited to the following embodiments.

[0136] Example 1

[0137] Figure 1 This is a schematic diagram of the structure of the industrial lens in Embodiment 1 of the present invention;

[0138] Figure 2 This is a schematic diagram of distortion of the industrial lens in Embodiment 1 of the present invention when the object distance is 0.3m;

[0139] Figure 3 This is a schematic diagram of distortion when the object distance of the industrial lens in Embodiment 1 of the present invention is at infinity.

[0140] In Embodiment 1, the first lens L1 is a convex-planar lens with positive optical power, the second lens L2 is a concave-concave lens with negative optical power, the third lens L3 is a convex-convex lens with positive optical power, the fourth lens L4 is a concave-concave lens with negative optical power, the fifth lens L5 is a convex-convex lens with positive optical power, the sixth lens L6 is a convex-convex lens with positive optical power, the seventh lens L7 is a concave-concave lens with negative optical power, the eighth lens L8 is a convex-convex lens with positive optical power, the ninth lens L9 is a concave-concave lens with negative optical power, the tenth lens L10 is a convex-convex lens with positive optical power, and the eleventh lens L11 is a concave-concave lens with negative optical power.

[0141] The third lens L3, the fourth lens L4, and the fifth lens L5 form a cemented triplet lens; the sixth lens L6 and the seventh lens L7 form a cemented doublet lens; and the eighth lens L8, the ninth lens L9, the tenth lens L10, and the eleventh lens L11 form a cemented quadruplet lens. The aperture stop STO is positioned behind the image-side surface of the eleventh lens L11.

[0142] Table 2 lists the relevant parameters of each lens in the industrial lens of this embodiment, including: surface type, radius of curvature R, thickness d, refractive index Nd of the material and Abbe number Vd.

[0143]

[0144]

[0145] Table 2

[0146] Table 3 lists the variable spacing values ​​between the lens groups of the industrial lens in this embodiment as the object distance changes from 0.3M to infinity.

[0147] Face number thickness When the object distance is 0.3M The object distance is infinity S8 T0 21.994 4.000 S11 T1 4.006 22.000

[0148] Table 3

[0149] In Example 1, the effective focal length FI of the industrial lens is 40.96 when the object distance is 0.3m, the effective focal length FII is 38.01 when the object distance is infinity, the aperture FNO is 3.0, the optical distortion is -0.54% to -1.07%, and the relative illumination is 70%.

[0150] Combination Figures 1 to 3 As shown in Tables 1 to 3 above, this embodiment is an industrial lens that has at least one of the following characteristics: low distortion (absolute optical distortion ≤ 1.1%), high illumination (RI ≥ 70%), miniaturization (TTL ≤ 85mm), aperture located at the end of the system, constant aperture (FN0 = 3.0), clear resolution of object distances from 0.3m to infinity, no defocusing in the temperature range of -40℃ to +80℃, and normal operation in various high and low temperature environments.

[0151] Example 2

[0152] Figure 4 This is a schematic diagram of the structure of the industrial lens in Embodiment 2 of the present invention;

[0153] Figure 5 This is a schematic diagram of distortion of the industrial lens in Embodiment 2 of the present invention when the object distance is 0.3m;

[0154] Figure 6 This is a schematic diagram of distortion when the object distance of the industrial lens in Embodiment 2 of the present invention is at infinity.

[0155] In Embodiment 2, the first lens L1 is a convex-convex lens with positive optical power, the second lens L2 is a concave-concave lens with negative optical power, the third lens L3 is a convex-convex lens with positive optical power, the fourth lens L4 is a concave-concave lens with negative optical power, the fifth lens L5 is a convex-convex lens with positive optical power, the sixth lens L6 is a concave-convex lens with positive optical power, the seventh lens L7 is a concave-concave lens with negative optical power, the eighth lens L8 is a convex-convex lens with positive optical power, the ninth lens L9 is a concave-concave lens with negative optical power, the tenth lens L10 is a convex-convex lens with positive optical power, and the eleventh lens L11 is a concave-concave lens with negative optical power.

[0156] The third lens L3, the fourth lens L4, and the fifth lens L5 form a cemented triplet lens; the sixth lens L6 and the seventh lens L7 form a cemented doublet lens; and the eighth lens L8, the ninth lens L9, the tenth lens L10, and the eleventh lens L11 form a cemented quadruplet lens. The aperture stop STO is positioned behind the image-side surface of the eleventh lens L11.

[0157] Table 4 lists the relevant parameters of each lens in the industrial lens of this embodiment, including: surface type, radius of curvature R, thickness d, refractive index Nd of the material and Abbe number Vd.

[0158] Surface serial number Surface type radius of curvature R Thickness d Refractive index Nd Abbe number Vd S1 spherical 41.165 2.380 1.871 40.73 S2 spherical -859.303 0.902 S3 spherical -68.723 0.800 1.648 33.89 S4 spherical 32.891 17.736 S5 spherical 36.191 3.024 1.834 37.32 S6 spherical -65.105 0.700 1.654 39.54 S7 spherical 13.633 4.248 1.593 68.34 S8 spherical -129.610 T0 S9 spherical -61.007 3.944 1.946 17.94 S10 spherical -26.719 0.700 1.567 42.81 S11 spherical 22.513 T1 S12 spherical 21.905 2.863 2.001 25.47 S13 spherical -25.963 0.700 1.673 32.17 S14 spherical 8.461 3.720 1.593 66.99 S15 spherical -15.944 0.700 1.855 25.15 S16 spherical 173.198 0.400 S17(STO) spherical Infinity 25.184 S18 spherical Infinity 0.900 1.517 64.20 S19 spherical Infinity 0.100 S20(IMA) spherical Infinity 0.000

[0159] Table 4

[0160] Table 5 lists the variable spacing values ​​between the lens groups of the industrial lens in this embodiment as the object distance changes from 0.3M to infinity.

[0161] Face number thickness Wide-angle end telephoto end S8 T0 11.994 3.998 S11 T1 4.006 12.002

[0162] Table 5

[0163] In Example 2, the effective focal length FI of the industrial lens is 40.76 when the object distance is 0.3m, the effective focal length FII is 38.24 when the object distance is infinity, the aperture FNO is 3.0, the optical distortion is -0.24% to -0.75%, and the relative illumination is 73%.

[0164] Combination Figures 4 to 6 As shown in Tables 1, 4 and 5 above, this second embodiment is an industrial lens with at least one of the following characteristics: low distortion (absolute optical distortion ≤ 1.1%), high illumination (RI ≥ 70%), miniaturization (TTL ≤ 85mm), aperture located at the end of the system, constant aperture (FN0 = 3.0), clear resolution at object distances from 0.3m to infinity, no defocusing in the temperature range of -40℃ to +80℃, and normal operation in various high and low temperature environments.

[0165] Example 3

[0166] Figure 7 This is a schematic diagram of the structure of the industrial lens in Embodiment 3 of the present invention;

[0167] Figure 8 This is a schematic diagram of distortion of the industrial lens in Embodiment 3 of the present invention when the object distance is 0.3m;

[0168] Figure 9 This is a schematic diagram of distortion when the object distance of the industrial lens in Embodiment 3 of the present invention is infinity.

[0169] In Embodiment 3, the first lens L1 is a convex-convex lens with positive optical power, the second lens L2 is a concave-concave lens with negative optical power, the third lens L3 is a convex-convex lens with positive optical power, the fourth lens L4 is a concave-concave lens with negative optical power, the fifth lens L5 is a convex-convex lens with positive optical power, the sixth lens L6 is a convex-convex lens with positive optical power, the seventh lens L7 is a concave-concave lens with negative optical power, the eighth lens L8 is a convex-convex lens with positive optical power, the ninth lens L9 is a concave-concave lens with negative optical power, the tenth lens L10 is a convex-convex lens with positive optical power, and the eleventh lens L11 is a concave-concave lens with negative optical power.

[0170] The third lens L3, the fourth lens L4, and the fifth lens L5 form a cemented triplet lens; the sixth lens L6 and the seventh lens L7 form a cemented doublet lens; and the ninth lens L9, the tenth lens L10, and the eleventh lens L11 form a cemented triplet lens. The aperture stop STO is positioned behind the image-side surface of the eleventh lens L11.

[0171] Table 6 lists the relevant parameters of each lens in the industrial lens of this embodiment, including: surface type, radius of curvature R, thickness d, refractive index Nd of the material, and Abbe number Vd.

[0172]

[0173]

[0174] Table 6

[0175] Table 7 lists the variable spacing values ​​between the lens groups of the industrial lens in this embodiment as the object distance changes from 0.3M to infinity.

[0176] Face number thickness Wide-angle end telephoto end S8 T0 14.139 2.000 S11 T1 8.287 20.426

[0177] Table 7

[0178] In Example 3, the effective focal length FI of the industrial lens is 39.08 when the object distance is 0.3m, the effective focal length FII is 36.52 when the object distance is infinity, the aperture FNO is 3.0, the optical distortion is -0.58% to -1.00%, and the relative illumination is 75%.

[0179] Combination Figures 7 to 9 As shown in Tables 1, 6 and 7 above, this embodiment three is an industrial lens that has at least one of the following characteristics: low distortion (absolute optical distortion ≤ 1.1%), high illumination (RI ≥ 70%), miniaturization (TTL ≤ 85mm), aperture located at the end of the system, constant aperture (FN0 = 3.0), clear resolution of object distances from 0.3m to infinity, no defocusing in the temperature range of -40℃ to +80℃, and normal operation in various high and low temperature environments.

[0180] Example 4

[0181] Figure 10 This is a schematic diagram of the structure of the industrial lens in Embodiment 4 of the present invention;

[0182] Figure 11 This is a schematic diagram of distortion of the industrial lens in Embodiment 4 of the present invention when the object distance is 0.3m;

[0183] Figure 12 This is a schematic diagram of distortion when the object distance of the industrial lens in Embodiment 4 of the present invention is infinity.

[0184] In Embodiment 4, the first lens L1 is a convex-convex lens with positive optical power, the second lens L2 is a concave-concave lens with negative optical power, the third lens L3 is a convex-convex lens with positive optical power, the fourth lens L4 is a concave-concave lens with negative optical power, the fifth lens L5 is a convex-convex lens with positive optical power, the sixth lens L6 is a convex-convex lens with positive optical power, the seventh lens L7 is a concave-concave lens with negative optical power, the eighth lens L8 is a convex-concave lens with negative optical power, the ninth lens L9 is a convex-concave lens with positive optical power, the tenth lens L10 is a convex-convex lens with positive optical power, and the eleventh lens L11 is a concave-concave lens with negative optical power.

[0185] The third lens L3, the fourth lens L4, and the fifth lens L5 form a cemented triplet lens; the sixth lens L6 and the seventh lens L7 form a cemented doublet lens; the eighth lens L8 and the ninth lens L9 form a cemented doublet lens; and the tenth lens L10 and the eleventh lens L11 form a cemented doublet lens. The aperture stop STO is positioned behind the image-side surface of the eleventh lens L11.

[0186] Table 8 lists the relevant parameters of each lens in the industrial lens of this embodiment, including: surface type, radius of curvature R, thickness d, refractive index Nd of the material and Abbe number Vd.

[0187]

[0188]

[0189] Table 8

[0190] Table 9 lists the variable spacing values ​​between the lens groups of the industrial lens in this embodiment as the object distance changes from 0.3M to infinity.

[0191] Face number thickness Wide-angle end telephoto end S8 T0 11.517 2.000 S11 T1 2.083 11.600

[0192] Table 9

[0193] In Example 4, the effective focal length FI of the industrial lens is 39.72 when the object distance is 0.3m, the effective focal length FII is 38.79 when the object distance is infinity, the aperture FNO is 3.0, the optical distortion is -0.48% to -0.77%, and the relative illumination is 73%.

[0194] Combination Figures 10 to 12As shown in Tables 1, 8 and 9 above, this embodiment four is an industrial lens that has at least one of the following characteristics: low distortion (absolute optical distortion ≤ 1.1%), high illumination (RI ≥ 70%), miniaturization (TTL ≤ 85mm), aperture located at the end of the system, constant aperture (FN0 = 3.0), clear resolution of object distances from 0.3m to infinity, no defocusing in the temperature range of -40℃ to +80℃, and normal operation in various high and low temperature environments.

[0195] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. An industrial lens, characterized in that, Along the optical axis from the object side to the image side, it consists of a first lens group (G1) with positive optical power, a second lens group (G2) with negative optical power, and a third lens group (G3) with positive optical power. The first lens group (G1) and the third lens group are fixed lens groups, and the second lens group (G2) is a focusing group that moves along the optical axis of the industrial lens. The first lens group (G1) consists of a first lens (L1) with positive optical power, a second lens (L2) with negative optical power, a third lens (L3) with positive optical power, a fourth lens (L4) with negative optical power, and a fifth lens (L5) with positive optical power. The second lens group (G2) consists of a sixth lens (L6) with positive optical power and a seventh lens (L7) with negative optical power; The third lens group (G3) consists of an eighth lens (L8), a ninth lens (L9), a tenth lens (L9) with positive optical power, and an eleventh lens (L11) with negative optical power; the optical powers of the eighth lens (L8) and the ninth lens (L9) are opposite. The effective focal length FG2 of the second lens group (G2) and the total effective focal length FI of the industrial lens at an object distance of 0.3m satisfy the following relationship: -2.2≤FG2 / FI≤-0.

7.

2. The industrial lens according to claim 1, characterized in that, The object side of the first lens (L1) is convex, the second lens (L2) is a concave-concave lens, the third lens (L3) is a convex-convex lens, the fourth lens (L4) is a concave-concave lens, and the fifth lens (L5) is a convex-convex lens.

3. The industrial lens according to claim 1, characterized in that, The image-side surface of the sixth lens (L6) is convex; the seventh lens (L7) is a concave-concave lens.

4. The industrial lens according to claim 1, characterized in that, The eighth lens (L8) is a convex-convex lens or a convex-concave lens, the ninth lens (L9) is a concave-concave lens or a convex-concave lens, the tenth lens (L10) is a convex-convex lens, and the eleventh lens (L11) is a concave-concave lens.

5. The industrial lens according to claim 1, characterized in that, The third lens (L3), the fourth lens (L4), and the fifth lens (L5) form a set of cemented triplet lenses, and the sixth lens (L6) and the seventh lens (L7) form a set of cemented doublet lenses.

6. The industrial lens according to claim 1, characterized in that, The eighth lens (L8), the ninth lens (L9), the tenth lens (L10), and the eleventh lens (L11) are combined to form two sets of cemented doublet lenses; Alternatively, the ninth lens (L9), the tenth lens (L10), and the eleventh lens (L11) can be combined to form a set of cemented triplet lenses; Alternatively, the eighth lens (L8), the ninth lens (L9), the tenth lens (L10), and the eleventh lens (L11) can be combined to form a set of four-colloidal lenses.

7. The industrial lens according to any one of claims 1 to 6, characterized in that, The total optical system length TTL of the industrial lens and the total effective focal length FI of the industrial lens at an object distance of 0.3m satisfy the following relationship: 2.0≤TTL / FI≤2.

2.

8. The industrial lens according to any one of claims 1 to 6, characterized in that, The total optical system length (TTL) of the industrial lens and the back focal length (BFL) of the industrial lens satisfy the following relationship: 3.1 ≤ TTL / BFL ≤ 3.

5.

9. The industrial lens according to any one of claims 1 to 6, characterized in that, The effective focal length FG1 of the first lens group (G1) and the total effective focal length FI of the industrial lens at an object distance of 0.3m satisfy the following relationship: 1.0≤FG1 / FI≤1.

7.

10. The industrial lens according to any one of claims 1 to 6, characterized in that, The effective focal length FG3 of the third lens group (G3) and the total effective focal length FI of the industrial lens at an object distance of 0.3m satisfy the following relationship: 0.7≤FG3 / FI≤1.

1.

11. The industrial lens according to any one of claims 1 to 6, characterized in that, The total effective focal length FI of the industrial lens at an object distance of 0.3m and the total effective focal length FII of the industrial lens at an object distance of infinity satisfy the following relationship: 0.97≤FI / FII≤1.

13.

12. The industrial lens according to any one of claims 1 to 6, characterized in that, The effective focal length F1 of the first lens (L1) and the effective focal length FG1 of the first lens group (G1) satisfy the following relationship: 0.6≤F1 / FG1≤1.

1.

13. The industrial lens according to any one of claims 1 to 6, characterized in that, The effective focal length F2 of the second lens (L2) and the effective focal length FG1 of the first lens group (G1) satisfy the following relationship: -0.9≤F2 / FG1≤-0.

19.

14. The industrial lens according to any one of claims 1 to 6, characterized in that, The effective focal length Fa of the cemented triplet lens composed of the third lens (L3) to the fifth lens (L5) satisfies the following relationship with the effective focal length FG1 of the first lens group (G1): 0.37≤Fa / FG1≤0.

91.

15. The industrial lens according to any one of claims 1 to 6, characterized in that, The air gap distance d23 between the second lens (L2) and the third lens (L3) on the optical axis satisfies the following relationship with the effective focal length FG1 of the first lens group (G1): 0.06≤d23 / FG1≤0.

45.

16. The industrial lens according to any one of claims 1 to 6, characterized in that, The effective focal length F6 of the sixth lens (L6) and the effective focal length FG2 of the second lens group (G2) satisfy the following relationship: -1.4≤F6 / FG2≤-0.

5.

17. The industrial lens according to any one of claims 1 to 6, characterized in that, The effective focal length F7 of the seventh lens (L7) and the effective focal length FG2 of the second lens group (G2) satisfy the following relationship: 0.3≤F7 / FG2≤0.

7.

18. The industrial lens according to any one of claims 1 to 6, characterized in that, The focusing distance d_G2 of the second lens group (G2) within the range of object distance variation satisfies the following relationship with the total effective focal length FI of the industrial lens at an object distance of 0.3m: 0.14≤d_G2 / FI≤0.

5.

19. The industrial lens according to any one of claims 1 to 6, characterized in that, The effective focal length F8 of the eighth lens (L8) and the effective focal length F9 of the ninth lens (L9) satisfy the following relationship: -1.6≤F8 / F9≤-0.

5.

20. The industrial lens according to any one of claims 1 to 6, characterized in that, The effective focal length F10 of the tenth lens (L10) and the effective focal length FG3 of the third lens group (G3) satisfy the following relationship: 0.2≤F10 / FG3≤0.

4.

21. The industrial lens according to any one of claims 1 to 6, characterized in that, The effective focal length F11 of the eleventh lens (L11) and the effective focal length FG3 of the third lens group (G3) satisfy the following relationship: -0.6≤F11 / FG3≤-0.

3.

22. The industrial lens according to any one of claims 1 to 6, characterized in that, The effective focal lengths F8 of the eighth lens (L8), F9 of the ninth lens (L9), F10 of the tenth lens (L10), F11 of the eleventh lens (L11), and FG3 of the third lens group (G3) satisfy the following relationship: -0.3≤(F8+F9+F10+F11) / FG3≤1.

0.

23. The industrial lens according to any one of claims 1 to 6, characterized in that, The refractive index Nd3 of the third lens (L3) under d-ray and the center thickness t3 of the third lens (L3) satisfy the following relationship: 0.3mm -1 ≤Nd3 / t3≤0.7mm -1 .

24. The industrial lens according to any one of claims 1 to 6, characterized in that, The Abbe number Vd6 of the sixth lens (L6), the Abbe number Vd7 of the seventh lens (L7), and the total effective focal length FI of the industrial lens at an object distance of 0.3m satisfy the following relationship: 0.2mm -1 ≤|Vd7-Vd6| / FI≤0.7mm -1 。 25. The industrial lens according to any one of claims 1 to 6, characterized in that, The Abbe number Vd10 of the tenth lens (L10), the Abbe number Vd11 of the eleventh lens (L11), and the total effective focal length FI of the industrial lens at an object distance of 0.3m satisfy the following relationship: 0.5mm -1 ≤|Vd10-Vd11| / FI≤1.2mm -1 .

26. The industrial lens according to any one of claims 1 to 6, characterized in that, The total optical system length TTL of the industrial lens and the maximum effective aperture D_max of the lenses from the first lens (L1) to the eleventh lens (L11) satisfy the following relationship: 4.34≤TTL / D_max≤5.

46.

27. The industrial lens according to claim 1, characterized in that, The industrial lens must meet at least one of the following conditions: 2.02≤TTL / FI≤2.19 3.14≤TTL / BFL≤3.45 1.10≤FG1 / FI≤1.66, -1.98≤FG2 / FI≤-0.86, 0.71≤FG3 / FI≤1.09 1.00≤FI / FII≤1.10, 0.63≤F1 / FG1≤1.01, -0.78≤F2 / FG1≤-0.23, 0.40≤Fa / FG1≤0.89, 0.06≤d23 / FG1≤0.43, -1.32≤F6 / FG2≤-0.58, 0.33≤F7 / FG2≤0.63 0.14≤d_G2 / FI≤0.49, -1.46≤F8 / F9≤-0.64, 0.20≤F10 / FG3≤0.38 -0.60≤F11 / FG3≤-0.32, -0.19≤(F8+F9+F10+F11) / FG3≤0.90, 0.32mm -1 ≤Nd3 / t3≤0.66mm -1 , 0.23mm -1 ≤|Vd7-Vd6| / FI≤0.66mm -1 , 0.56mm -1 ≤|Vd10-Vd11| / FI≤1.09mm -1 , 4.44≤TTL / D_max≤5.35 in, TTL is the total length of the optical system of the industrial lens; FI is the focal length of the industrial lens at an object distance of 0.3m; BFL is the back focal length of the industrial lens; FG1 is the focal length of the first lens group (G1); FG2 is the focal length of the second lens group (G2); FG3 is the focal length of the third lens group (G3); FII is the focal length of the industrial lens at an object distance of infinity; F1 is the focal length of the first lens (L1); F2 is the focal length of the second lens (L2); Fa is the focal length of the cemented triplet lens composed of the third lens (L3) to the fifth lens (L5); d23 is the air gap distance between the second lens (L2) and the third lens (L3) on the optical axis; F6 is the focal length of the sixth lens (L6); F7 is the focal length of the seventh lens (L7). The focal length of the lens group (G2) is d_G2; the focal length of the eighth lens (L8) is F8; the focal length of the ninth lens (L9) is F9; the focal length of the tenth lens (L10) is F10; the focal length of the eleventh lens (L11) is F11; the refractive index of the third lens (L3) under d light is Nd3; the center thickness of the third lens (L3) is t3; the Abbe number of the sixth lens (L6) is Vd6; the Abbe number of the seventh lens (L7) is Vd7; the Abbe number of the tenth lens (L10) is Vd7; the Abbe number of the eleventh lens (L11) is Vd10; the Abbe number of the eleventh lens (L11) is Vd11; and the maximum effective aperture of the lens group from the first lens (L1) to the eleventh lens (L11) is D_max.

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