Industrial lens

Abstract

The utility model relates to an industrial lens, which sequentially comprises a first lens group with positive focal power, a second lens group with negative focal power and a third lens group with positive focal power along an optical axis from an object side to an image side, the first lens group and the third lens group are fixed lens groups, and the second lens group is a focusing group; the first lens group comprises a first lens with positive focal power, a second lens with negative focal power, a third lens with positive focal power, a fourth lens with negative focal power and a fifth lens with positive focal power; the second lens group comprises a sixth lens with positive focal power and a seventh lens with negative focal power; the third lens group comprises an eighth lens and a ninth lens which are opposite in focal power, a tenth lens with positive focal power and an eleventh lens with negative focal power. The industrial lens provided by the utility model has at least one of the characteristics of low distortion, high illumination, high resolution, wide focusing object distance range, no virtual focus in a temperature range from-40 DEG C to 80 DEG C, and the like.

Description

Technical Field

[0001] The utility model relates to the technical field of optical lenses, in particular to an industrial lens. Background Art

[0002] Industrial lenses are indispensable components in machine vision systems. They play a key role in applications such as automated inspection, quality control, measurement, and identification.

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

[0004] 1. The lens has large optical distortion, with large deformation in the four corners of the image, affecting object resolution;

[0005] 2. Insufficient illumination, dim picture effect and low color saturation;

[0006] 3. The imaging quality is not high, the picture is blurred, and it interferes with object resolution;

[0007] 4. The actual shooting distance range is narrow and cannot meet the needs of use 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 focus distance range, and no out-of-focus in the temperature range of -40℃ to +80℃ has become a market development trend. Utility Model Content

[0010] To address the problems existing in the above-mentioned prior art, the purpose of the present invention is to provide an industrial lens having at least one of the following characteristics: low distortion, high illumination, high resolution, a wide focus distance range, and no out-of-focus in the temperature range of -40°C to +80°C.

[0011] To achieve the above objectives, the present invention provides an industrial lens comprising, in order from the object side to the image side of the optical axis: 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, wherein the first lens group and the third lens group are fixed lens groups, and the second lens group is a focus adjustment group that moves along the optical axis of the industrial lens;

[0012] The first lens group includes, in order: 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 having positive optical power and a seventh lens having negative optical power, a total of two lenses;

[0014] The third lens group includes, in order: 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 eighth lens and the ninth lens have opposite optical powers;

[0015] The first lens to the eleventh lens include at least three groups of cemented lenses.

[0016] According to a technical solution of the present invention, the object-side surface 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.

[0017] According to a technical solution of the present invention, the image-side surface of the sixth lens is a convex surface; and the seventh lens is a concave-concave lens.

[0018] According to a 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.

[0019] According to a technical solution of the present invention, the third lens, the fourth lens and the fifth lens form a group of triplet lenses, and the sixth lens and the seventh lens form a group of doublet lenses.

[0020] According to a technical solution of the present utility model, the eighth lens, the ninth lens, the tenth lens and the eleventh lens are combined into two groups of doublet lenses;

[0021] Alternatively, the ninth lens, the tenth lens, and the eleventh lens are combined into a triplet lens;

[0022] Alternatively, the eighth lens, the ninth lens, the tenth lens and the eleventh lens are combined into a quadruple lens.

[0023] According to a technical solution of the present invention, the total length TTL of the optical system of the industrial lens and the total effective focal length FI of the industrial lens when the object distance is 0.3m satisfy the following relationship: 2.0≤TTL / FI≤2.2.

[0024] According to a 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.

[0025] According to a 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 when the object distance is 0.3m satisfy the following relationship: 1.0≤FG1 / FI≤1.7.

[0026] According to a 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 when the object distance is 0.3m satisfy the following relationship: -2.2≤FG2 / FI≤-0.7.

[0027] According to a 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 when the object distance is 0.3m satisfy the following relationship: 0.7≤FG3 / FI≤1.1.

[0028] According to a technical solution of the present invention, the total effective focal length FI of the industrial lens when the object distance is 0.3m and the total effective focal length FII of the industrial lens when the object distance is infinity satisfy the following relationship: 0.97≤FI / FII≤1.13.

[0029] According to a 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.

[0030] According to a 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.

[0031] According to a technical solution of the present invention, the effective focal length Fa of the triplet lens composed of the third to fifth lenses and the effective focal length FG1 of the first lens group satisfy the following relationship: 0.37≤Fa / FG1≤0.91.

[0032] According to a technical solution of the present invention, the air 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.

[0033] According to a 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.

[0034] According to a 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.

[0035] According to a technical solution of the present invention, the focus 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 when the object distance is 0.3m satisfy the following relationship: 0.14≤d_G2 / FI≤0.5.

[0036] According to a 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.

[0037] According to a 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.

[0038] According to a 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.

[0039] According to a technical solution of the present invention, the effective focal length F8 of the eighth lens element, the effective focal length F9 of the ninth lens element, the effective focal length F10 of the tenth lens element, the effective focal length F11 of the eleventh lens element, and the effective focal length FG3 of the third lens group satisfy the following relationship: -0.3≤(F8+F9+F10+F11) / FG3≤1.0.

[0040] According to a technical solution of the present invention, the refractive index value Nd3 of the third lens under d light and the central thickness value t3 of the third lens satisfy the following relationship: 0.3≤Nd3 / t3≤0.7.

[0041] According to a 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 when the object distance is 0.3m satisfy the following relationship: 0.2≤|Vd7-Vd6| / FI≤0.7.

[0042] According to a 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 when the object distance is 0.3m satisfy the following relationship: 0.5≤|Vd10-Vd11| / FI≤1.2.

[0043] According to a technical solution of the present invention, the total length TTL of the optical system 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.

[0044] According to a technical solution of the present utility model, the industrial lens meets at least one of the following conditions:

[0045] 2.02≤TTL / FI≤2.19,

[0046] 3.14≤TTL / BFL≤3.45,

[0047] 1.10≤FG1 / FI≤1.66,

[0048] -1.98≤FG2 / FI≤-0.86,

[0049] 0.71≤FG3 / FI≤1.09,

[0050] 1.00≤FI / FII≤1.10,

[0051] 0.63≤F1 / FG1≤1.01,

[0052] -0.78≤F2 / FG1≤-0.23,

[0053] 0.40≤Fa / FG1≤0.89,

[0054] 0.06≤d23 / FG1≤0.43,

[0055] -1.32≤F6 / FG2≤-0.58,

[0056] 0.33≤F7 / FG2≤0.63,

[0057] 0.14≤d_G2 / FI≤0.49,

[0058] -1.46≤F8 / F9≤-0.64,

[0059] 0.20≤F10 / FG3≤0.38,

[0060] -0.60≤F11 / FG3≤-0.32,

[0061] -0.19≤(F8+F9+F10+F11) / FG3≤0.90,

[0062] 0.32≤Nd3 / t3≤0.66,

[0063] 0.23≤|Vd7-Vd6| / FI≤0.66,

[0064] 0.56≤|Vd10-Vd11| / FI≤1.09,

[0065] 4.44≤TTL / D_max≤5.35,

[0066] Wherein, TTL is the total length of the optical system of the industrial lens; FI is the focal length of the industrial lens when the object distance is 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 when the object distance is 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 triplet lens composed of the third lens to the fifth lens; d23 is the air spacing 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 focus shift distance of the second lens group within the object distance variation range; 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; and D_max is the maximum effective aperture of the lenses from the first lens to the eleventh lens.

[0067] According to the solution of the present invention, by setting the number and optical power of industrial lenses, the ultra-wide-angle lens can achieve at least one of the following beneficial effects: low distortion (absolute value of 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. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be derived from these drawings without inventive effort.

[0069] Figure 1This is a schematic structural diagram of an industrial lens according to Example 1 of the present utility model;

[0070] Figure 2 This is a schematic diagram of the distortion of the industrial lens of Example 1 of the present utility model when the object distance is 0.3m;

[0071] Figure 3 Schematic diagram of distortion of the industrial lens of Example 1 of the present utility model when the object distance is infinite;

[0072] Figure 4 This is a schematic structural diagram of an industrial lens according to Example 2 of the present utility model;

[0073] Figure 5 Schematic diagram of distortion of the industrial lens of Example 2 of the present utility model when the object distance is 0.3m;

[0074] Figure 6 Schematic diagram of distortion of the industrial lens of Example 2 of the present utility model when the object distance is infinite;

[0075] Figure 7 This is a schematic structural diagram of an industrial lens according to Example 3 of the present utility model;

[0076] Figure 8 Schematic diagram of distortion of the industrial lens of Example 3 of the present utility model when the object distance is 0.3m;

[0077] Figure 9 Schematic diagram of distortion of the industrial lens of Example 3 of the present utility model when the object distance is infinite;

[0078] Figure 10 This is a schematic structural diagram of an industrial lens according to a fourth embodiment of the present invention;

[0079] Figure 11 Schematic diagram of distortion of the industrial lens of Example 4 of the present utility model when the object distance is 0.3m;

[0080] Figure 12 Schematic diagram of the distortion of the industrial lens of Example 4 of the present invention when the object distance is infinite. DETAILED DESCRIPTION

[0081] For a better understanding of the present application, various aspects of the present application will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed descriptions are merely descriptions of exemplary embodiments of the present application and are not intended to limit the scope of the present 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.

[0082] It should be noted that in this specification, the expressions first, second, third, etc. are only used to distinguish one feature from another, and do not represent 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.

[0083] In the drawings, the thickness, size, and shape of the lenses are slightly exaggerated for ease of illustration. Specifically, the shapes of the spherical and aspherical surfaces shown in the drawings are provided by way of example. That is, the shapes of the spherical and aspherical surfaces are not limited to those shown in the drawings. The drawings are for illustration only and are not drawn strictly to scale.

[0084] In this article, the paraxial region refers to the area near the optical axis. If a lens surface is convex and the location of the convex surface is undefined, it means that the lens surface is convex at least in the paraxial region. If a lens surface is concave and the location of the concave surface is undefined, 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.

[0085] It should also be understood that the terms "comprises," "including," "having," "includes," and / or "comprising," when used in this specification, indicate the presence of the stated features, elements, and / or components, but do not preclude the presence or addition of one or more other features, elements, components, and / or combinations thereof. In addition, when expressions such as "at least one of..." appear after a list of listed features, they modify the entire list of features rather than modifying the individual elements in the list. In addition, when describing embodiments of the present application, "may" is used to mean "one or more embodiments of the present application." And, the term "exemplary" is intended to refer to an example or illustration.

[0086] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by those skilled in the art to which this application belongs. It should also be understood that terms (such as those defined in commonly used dictionaries) should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology and will not be interpreted in an idealized or overly formal sense unless expressly defined as such herein.

[0087] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The following examples only express several implementation methods of the present application, and their descriptions are relatively specific and detailed, but they should not be understood as limiting the scope of the patent application. It should be pointed out that for those of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all fall within the scope of protection of the present application.

[0088] like Figures 1 to 12 As shown, an embodiment of the present invention provides an industrial lens, which includes, along the optical axis from the object side to the image side,: 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.

[0089] Among them, the first lens group G1 is a fixed front group, and its position relative to the image plane is fixed during changes in object distance. The optical focal length of the first lens group G1 is positive, which is beneficial for converging incident light and reducing the aperture of the rear lens. It is also beneficial for correcting system aberrations and distortion, while reducing tolerance sensitivity and ensuring image uniformity.

[0090] The second lens group G2 is a focusing group, and the optical focal length of the second lens group G2 is negative, which can smooth the light trend. At the same time, by moving the position of the second lens group G2 on the optical axis, the lens can focus at an object distance of 0.3m to infinity, ensuring clear imaging at different object distances.

[0091] The third lens group G3 is a fixed rear group, fixed relative to the image plane, and the optical focal length of the third lens group G3 is positive, which can ensure a constant aperture and smooth the outgoing light. This is beneficial to reduce astigmatism and field curvature changes during focusing, reduce system sensitivity, and ensure production yield.

[0092] In the embodiment of the present invention, along the direction from the object side to the image side of the optical axis, the first lens group G1 includes: a first lens L1, a second lens L2, a third lens L3, a fourth lens L4 and a fifth lens L5, a total of five lenses.

[0093] The object-side surface of the first lens L1 is convex and has positive refractive power, which is conducive to converging incident light and reducing distortion.

[0094] 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 with positive optical power, it helps to reduce spherical aberration.

[0095] The third lens L3 is a convex-convex lens with positive refractive power. It is made of high-refractive material, which can reduce the height of the light and is conducive to miniaturization.

[0096] The fourth lens element L4 is a concave-concave lens with negative optical power, and the fifth lens element L5 is a convex-convex lens with positive optical power. Together with the third lens element L3, they form a positive-negative-positive structure. By adopting appropriate lens materials, they can balance system chromatic aberration and improve image quality.

[0097] In the embodiment of the present invention, the third lens L3, the fourth lens L4 and the fifth lens L5 can be combined into a triplet lens, which effectively reduces the tolerance sensitivity of the optical system and improves the production yield.

[0098] In the embodiment of the present invention, along the direction from the object side to the image side of the optical axis, the second lens group G2 includes, in sequence, a sixth lens L6 and a seventh lens L7, for a total of two lenses;

[0099] The image-side surface of the sixth lens element L6 is convex and has positive refractive power. High-refractive-index materials can be used to collect light rays emitted from the first lens group G1 and control their trajectory. This helps reduce field curvature at different object distances and improves the lens resolution.

[0100] The seventh lens L7 is a concave-concave lens with negative optical power. It is matched with the sixth lens L6 in a positive and negative manner to correct spherical aberration, balance system chromatic aberration, and ensure imaging performance at different object distances.

[0101] In the embodiment of the present invention, the sixth lens L6 and the seventh lens L7 can cooperate with each other to form a doublet lens group, thereby effectively reducing the tolerance sensitivity of the optical system and improving the production yield.

[0102] In the embodiment of the present 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.

[0103] The eighth lens L8 and the ninth lens L9 have opposite refractive powers, which can achieve the complementarity of positive spherical aberration and negative spherical aberration, reduce system aberrations, and facilitate clear imaging.

[0104] The tenth lens L10 is a convex-convex lens with positive refractive power, which can effectively balance the astigmatism and distortion introduced by the front lens group.

[0105] The object-side surface of the eleventh lens L11 is concave and has negative optical power. It is cemented with the tenth lens L10 to reduce chromatic aberration caused by the front lens group and balance the system aberration.

[0106] In the embodiments of the present invention, the eighth lens element L8, the ninth lens element L9, the tenth lens element L10, and the eleventh lens element L11 can be combined into a quadruple lens, or a singlet lens and a triplet lens, or two doublet lenses. This can effectively balance system chromatic aberration, reduce tolerance sensitivity, and ensure imaging quality at different object distances under a constant aperture.

[0107] The utility model can keep the aperture constant when the object distance changes from 0.3m to infinity, so that the imaging quality is stable and meets the needs of various scenes.

[0108] The lens of this utility model adopts three lens groups: fixed, focusing and fixed, and has a combination of positive, negative and positive optical powers. It is beneficial to correct field curvature and distortion at different object distances from 0.3m to infinity, eliminate system chromatic aberration, reduce tolerance sensitivity, and ensure clear imaging at different object distances.

[0109] In some embodiments of the present invention, all lens elements, L1 through L11, are made of glass. This reduces the risk of significant changes in lens size, refractive index, and surface shape due to temperature fluctuations in high and low temperature environments, improves system stability, and facilitates athermalization, ensuring that the lens maintains focus within a temperature range of -40°C to 80°C, ensuring clear images. Furthermore, glass can effectively correct system chromatic aberration, ensuring lens quality.

[0110] In some embodiments of the present invention, the total optical length (TTL) of an industrial lens and its total effective focal length (FI) at an object distance of 0.3m satisfy the following relationship: 2.0 ≤ TTL / FI ≤ 2.2, preferably 2.03 ≤ TTL / FI ≤ 2.19. By controlling the total optical length of the system, the system can be reduced for a given focal length, facilitating miniaturization.

[0111] In some embodiments of the present invention, the total optical system length (TTL) of an industrial lens and its back focal length (BFL) (i.e., the on-axis distance from the image side of the last lens element to the imaging plane) satisfy the following relationship: 3.1 ≤ TTL / BFL ≤ 3.5, preferably, 3.14 ≤ TTL / BFL ≤ 3.45. By controlling the optical back focal length of the system while achieving miniaturization, the lens back focal length is extended, which helps reserve space for optical component installation, facilitates assembly of the industrial lens, avoids interference, and improves the assembly yield of the industrial lens.

[0112] 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. Properly 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 facilitates focusing incident light entering the optical system, effectively controlling the trajectory of light, correcting system aberrations and distortion, reducing tolerance sensitivity, and improving the imaging quality of the lens.

[0113] 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. Properly 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 enables lens focusing from an object distance of 0.3m to infinity, ensuring clear imaging at various object distances.

[0114] 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. Properly 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 smoothes the outgoing light and ensures a smooth transition to the image plane, thereby reducing astigmatism and field curvature aberrations on the image plane and improving image quality. It also effectively compensates for axial chromatic aberration of the front lens group, ensuring image quality.

[0115] 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. Properly controlling the ratio of the optical system's effective focal lengths at an object distance of 0.3m and infinity can effectively reduce the lens's impact on the image as the object distance varies, meeting the requirements of a wide range of working distances.

[0116] In some embodiments of the present invention, the effective focal length F1 of first lens element L1 and the effective focal length FG1 of first lens group G1 satisfy the following relationship: 0.6 ≤ F1 / FG1 ≤ 1.1, preferably, 0.63 ≤ F1 / FG1 ≤ 1.01. Properly controlling the ratio of the effective focal length of first lens element L1 to the effective focal length of first lens group G1 facilitates focusing incident light and minimizing distortion.

[0117] In some embodiments of the present invention, the effective focal length F2 of second lens element L2 and the effective focal length FG1 of first lens group G1 satisfy the following relationship: -0.9 ≤ F2 / FG1 ≤ -0.19, preferably, -0.78 ≤ F2 / FG1 ≤ -0.23. By properly controlling the ratio of the effective focal length of second lens element L2 to the effective focal length of first lens group G1, the path of light passing through first lens element L1 is smoothed, and when used in conjunction with the positive first lens element L1, spherical aberration is reduced.

[0118] In some embodiments of the present invention, the effective focal length Fa of the cemented triplet consisting of third lens L3 through fifth lens L5 and the effective focal length FG1 of first lens group G1 satisfy the following relationship: 0.37 ≤ Fa / FG1 ≤ 0.91, preferably, 0.40 ≤ Fa / FG1 ≤ 0.89. Properly controlling the ratio of the effective focal length of the cemented triplet in first lens group G1 to the effective focal length of first lens group G1 can effectively reduce system chromatic aberration and balance system spherical aberration, thereby improving resolution. It also reduces sensitivity to tolerances between lens elements, thereby increasing production yield.

[0119] In some embodiments of the present invention, the distance d23 between the second lens element L2 and the third lens element L3 on the optical axis and the effective focal length FG1 of the first lens group G1 satisfy the following relationship: 0.06 ≤ d23 / FG1 ≤ 0.45, preferably 0.06 ≤ d23 / FG1 ≤ 0.43. Properly controlling the distance d23 between the second lens element L2 and the third lens element L3 on the optical axis in the first lens group effectively controls the trajectory of light and reduces the angle of light refraction upon entering the object side of the third lens element L3. This helps reduce light energy loss and improves illumination. It also reduces the tolerance sensitivity of the third lens element L3, thereby improving production yield.

[0120] In some embodiments of the present invention, the effective focal length F6 of the sixth lens element 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. Properly controlling the ratio of the effective focal length of the sixth lens element L6 to the effective focal length of the second lens group G2 collects light rays emitted from the first lens group G1 and controls their distribution, thereby facilitating high illumination, reducing field curvature at varying object distances, and improving lens resolution.

[0121] In some embodiments of the present invention, the effective focal length F7 of the seventh lens element 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. Properly controlling the ratio of the effective focal length of the seventh lens element L7 to the effective focal length of the second lens group G2 facilitates correcting the spherical aberration produced by the sixth lens element L6, balancing system chromatic aberration, and ensuring imaging performance at various object distances.

[0122] In some embodiments of the present invention, the focus shift distance d_G2 of the second lens group G2 within the object distance 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. Reasonable control of the ratio of the focus shift distance of the second lens group G2 within the object distance range to the effective focal length of the optical system at an object distance of 0.3m ensures that the focus shift distance remains within a certain range, which facilitates system stability during focusing, improves the lens's focusing response speed, and ensures image quality at different object distances.

[0123] In some embodiments of the present invention, the effective focal length F8 of the eighth lens element L8 and the effective focal length F9 of the ninth lens element L9 satisfy the following relationship: -1.6 ≤ F8 / F9 ≤ -0.5, preferably, -1.46 ≤ F8 / F9 ≤ -0.64. By properly controlling the ratio of the effective focal length of the eighth lens element L8 to the effective focal length of the ninth lens element L9 and ensuring that the ratio is always negative, that is, the effective focal lengths of the eighth lens element L8 and the ninth lens element L9 are opposite in sign, positive and negative spherical aberrations can be complemented, thereby reducing system aberrations and facilitating clear imaging.

[0124] In some embodiments of the present invention, the effective focal length F10 of the tenth lens element 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. Properly controlling the ratio of the effective focal length of the tenth lens element L10 to the effective focal length of the third lens group G3 can effectively balance astigmatism and distortion introduced by the front lens group, reduce field curvature on the image plane, and improve image quality.

[0125] In some embodiments of the present invention, the effective focal length F11 of the eleventh lens element 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. Properly controlling the ratio of the effective focal length of the eleventh lens element L11 to the effective focal length of the third lens group G3 helps balance chromatic aberration produced by the positive tenth lens element L10 and minimize system aberrations.

[0126] In some embodiments of the present invention, the effective focal length F8 of the eighth lens element L8, the effective focal length F9 of the ninth lens element L9, the effective focal length F10 of the tenth lens element L10, and the effective focal length F11 of the eleventh lens element L11, together with the effective focal length FG3 of the third lens group G3, satisfies the following relationship: -0.3 ≤ (F8 + F9 + F10 + F11) / FG3 ≤ 1.0, preferably, -0.19 ≤ (F8 + F9 + F10 + F11) / FG3 ≤ 0.90. Properly configuring the optical powers of the eighth lens element L8, the ninth lens element L9, the tenth lens element L10, and the eleventh lens element L11 facilitates the mutual compensation of positive and negative spherical aberrations, corrects system astigmatism and field curvature, and improves lens resolution. Furthermore, it effectively controls the trajectory of light, ensuring a smooth transition, effectively reducing the tolerance sensitivity of the fixed rear lens group, and improving production yield.

[0127] In some embodiments of the present invention, the refractive index Nd3 of the third lens element L3 under d-light and its center thickness t3 satisfy the following relationship: 0.3 ≤ Nd3 / t3 ≤ 0.7, preferably, 0.32 ≤ Nd3 / t3 ≤ 0.66. Properly controlling the ratio of the refractive index of the third lens element L3 to its center thickness ensures a larger refractive index and converges light rays emitted from the second lens element L2. This helps ensure that the optical system is insensitive to changes in ambient temperature and object distance, achieving athermalization and making the lens suitable for high and low temperature environments.

[0128] In some embodiments of the present invention, the Abbe number Vd6 of the sixth lens element L6 and the Abbe number Vd7 of the seventh lens element 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 rationally controlling the ratio of the difference in the Abbe numbers of the seventh lens element L7 and the sixth lens element L6 to the effective focal length of the optical system at an object distance of 0.3m and employing materials with different chromatic aberration coefficients, dispersion can be compensated, eliminating positional chromatic aberration and improving the imaging performance of the telephoto lens. This can also effectively reduce the tolerance sensitivity of the optical system and increase the production yield of the lens.

[0129] In some embodiments of the present invention, the Abbe number Vd10 of the tenth lens element L10 and the Abbe number Vd11 of the eleventh lens element 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. Reasonable control of the ratio of the difference in the Abbe numbers of the tenth lens element L10 and the eleventh lens element L11 to the effective focal length of the optical system at an object distance of 0.3m, and the use of materials with different Abbe coefficients, can help reduce chromatic aberration produced by the front lens group and balance system aberrations.

[0130] In some embodiments of the present invention, the total optical system length TTL of the industrial lens and the maximum effective optical aperture D_max of the lenses L1 through L11 satisfy the following relationship: 4.34 ≤ TTL / D_max ≤ 5.46, preferably 4.44 ≤ TTL / D_max ≤ 5.35. By properly setting the ratio of the total optical system length to the maximum effective optical aperture of the lenses L1 through L11, the maximum effective optical aperture and the total optical system length can be properly constrained and controlled, facilitating lens miniaturization.

[0131] Based on the above-described configuration of the present invention, four sets of specific embodiments are provided below to illustrate the industrial lens according to the present invention. The industrial lens according to the present invention comprises eleven lenses, with each cemented surface of the cemented lens being referred to as a surface. Together with the aperture stop STO, the protective glass CG, and the image surface IMA, this results in a total of 20 or 21 surfaces. The aperture stop STO is positioned behind the image-side surface of the eleventh lens L11. For ease of description, the lens surfaces, the aperture stop STO, and the protective glass CG are numbered S1, S2 to S20 or S1, S2 to S21.

[0132] The data of the four examples are shown in Table 1 below:

[0133]

[0134]

[0135] Table 1

[0136] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. The embodiments cannot be described one by one here, but the embodiments of the present invention are not limited to the following embodiments.

[0137] Example 1

[0138] Figure 1 This is a schematic structural diagram of an industrial lens according to Example 1 of the present utility model;

[0139] Figure 2 This is a schematic diagram of the distortion of the industrial lens of Example 1 of the present utility model when the object distance is 0.3m;

[0140] Figure 3 Schematic diagram of the distortion of the industrial lens of Example 1 of the present invention when the object distance is infinite.

[0141] In Example 1, 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.

[0142] The third lens L3, the fourth lens L4, and the fifth lens L5 form a triplet, the sixth lens L6 and the seventh lens L7 form a doublet, and the eighth lens L8, the ninth lens L9, the tenth lens L10, and the eleventh lens L11 form a quadruple. A stop STO is located behind the image-side surface of the eleventh lens L11.

[0143] Table 2 lists the relevant parameters of each lens in the industrial lens of this embodiment, including: surface type, curvature radius R, thickness d, refractive index Nd and Abbe number Vd of the material.

[0144] Surface serial number Surface type Curvature radius R Thickness d Refractive index Nd Abbe number Vd S1 spherical surface 37.680 2.395 1.816 46.56 S2 spherical surface -1016.941 1.138 S3 spherical surface -45.296 4.667 1.689 31.16 S4 spherical surface 33.300 11.384 S5 spherical surface 59.765 3.637 1.921 23.96 S6 spherical surface -25.121 0.700 1.728 28.32 S7 spherical surface 16.548 4.161 1.660 57.35 S8 spherical surface -79.502 T0 S9 spherical surface 373.218 1.973 1.923 18.90 S10 spherical surface -56.485 0.700 1.620 36.35 S11 spherical surface 25.741 T1 S12 spherical surface 20.525 2.755 2.001 25.47 S13 spherical surface -31.253 1.163 1.648 33.89 S14 spherical surface 7.783 3.625 1.593 66.99 S15 spherical surface -16.831 0.700 1.855 25.15 S16 spherical surface 44.637 0.400 S17(STO) spherical surface Infinity 23.600 S18 spherical surface Infinity 0.900 1.520 64.2 S19 spherical surface Infinity 0.100 S20(IMA) spherical surface Infinity 0.000

[0145] Table 2

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

[0147] Surface number thickness When the object distance is 0.3M Object distance is infinite S8 T0 16.992 3.993 S11 T1 4.008 17.007

[0148] Table 3

[0149] In Example 1, the effective focal length FI of the industrial lens is 40.22 when the object distance is 0.3m, the effective focal length FII is 38.27 when the object distance is infinite, the aperture FNO is 3.0, the optical distortion is -0.46% to -0.99%, and the relative illumination is 73%.

[0150] Combine Figures 1 to 3 As shown in Tables 1, 2, and 3 above, this embodiment 1 is an industrial lens having 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 from 0.3m to infinity, no defocusing in the temperature range of -40°C to +80°C, and normal operation in various high and low temperature environments.

[0151] Example 2

[0152] Figure 4 This is a schematic structural diagram of an industrial lens according to Example 2 of the present utility model;

[0153] Figure 5 Schematic diagram of distortion of the industrial lens of Example 2 of the present utility model when the object distance is 0.3m;

[0154] Figure 6 Schematic diagram of the distortion of the industrial lens of Example 2 of the present invention when the object distance is infinite.

[0155] In Example 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 triplet, the sixth lens L6 and the seventh lens L7 form a doublet, and the eighth lens L8, the ninth lens L9, the tenth lens L10, and the eleventh lens L11 form a quadruple. A stop STO is located 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, curvature radius R, thickness d, refractive index Nd and Abbe number Vd of the material.

[0158]

[0159]

[0160] Table 4

[0161] Table 5 lists the variable spacing values ​​between lens groups of the industrial lens of this embodiment when the object distance changes from 0.3M to infinity.

[0162] Surface number thickness Wide-angle end Telephoto end S8 T0 11.994 3.998 S11 T1 4.006 12.002

[0163] Table 5

[0164] 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 infinite, the aperture FNO is 3.0, the optical distortion is -0.24% to -0.75%, and the relative illumination is 73%.

[0165] Combine Figures 4 to 6 As shown in Tables 1, 4, and 5 above, this embodiment 2 is an industrial lens having at least one of the following characteristics: low distortion (absolute optical distortion ≤ 1.1%), high illumination (RI ≥ 70%), miniaturization (TTL ≤ 85mm), an aperture located at the end of the system, a constant aperture (FN0 = 3.0), clear resolution from 0.3m to infinity, no defocusing in the temperature range of -40°C to +80°C, and normal operation in various high and low temperature environments.

[0166] Example 3

[0167] Figure 7 This is a schematic structural diagram of an industrial lens according to Example 3 of the present utility model;

[0168] Figure 8 Schematic diagram of distortion of the industrial lens of Example 3 of the present utility model when the object distance is 0.3m;

[0169] Figure 9 Schematic diagram of the distortion of the industrial lens of Example 3 of the present invention when the object distance is infinite.

[0170] In Example 3, the first lens L1 is a convex-convex lens with positive focal power, the second lens L2 is a concave-concave lens with negative focal power, the third lens L3 is a convex-convex lens with positive focal power, the fourth lens L4 is a concave-concave lens with negative focal power, the fifth lens L5 is a convex-convex lens with positive focal power, the sixth lens L6 is a convex-convex lens with positive focal power, the seventh lens L7 is a concave-concave lens with negative focal power, the eighth lens L8 is a convex-convex lens with positive focal power, the ninth lens L9 is a concave-concave lens with negative focal power, the tenth lens L10 is a convex-convex lens with positive focal power, and the eleventh lens L11 is a concave-concave lens with negative focal power.

[0171] The third lens L3, the fourth lens L4, and the fifth lens L5 form a triplet, the sixth lens L6 and the seventh lens L7 form a doublet, and the ninth lens L9, the tenth lens L10, and the eleventh lens L11 form a triplet. A stop STO is located behind the image-side surface of the eleventh lens L11.

[0172] Table 6 lists the relevant parameters of each lens in the industrial lens of this embodiment, including: surface type, curvature radius R, thickness d, refractive index Nd and Abbe number Vd of the material.

[0173] Surface serial number Surface type Curvature radius R Thickness d Refractive index Nd Abbe number Vd S1 spherical surface 41.139 1.899 1.804 46.57 S2 spherical surface -272.911 0.766 S3 spherical surface -40.019 0.704 1.728 28.32 S4 spherical surface 48.192 10.321 S5 spherical surface 77.181 4.869 1.923 18.90 S6 spherical surface -88.696 1.139 1.728 28.32 S7 spherical surface 22.376 3.912 1.652 58.40 S8 spherical surface -42.578 T0 S9 spherical surface 1576.411 1.688 1.946 17.99 S10 spherical surface -74.878 0.700 1.575 41.50 S11 spherical surface 26.809 T1 S12 spherical surface 22.886 3.481 2.051 26.95 S13 spherical surface -44.317 0.715 S14 spherical surface -36.175 1.067 1.717 29.50 S15 spherical surface 10.686 2.788 1.618 63.40 S16 spherical surface -17.943 1.365 1.755 27.53 S17 spherical surface 54.551 0.400 S18(STO) spherical surface Infinity 23.764 S19 spherical surface Infinity 0.900 1.517 64.20 S20 spherical surface Infinity 0.100 S21(IMA) spherical surface Infinity 0.000

[0174] Table 6

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

[0176] Surface 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 infinite, the aperture FNO is 3.0, the optical distortion is -0.58% to -1.00%, and the relative illumination is 75%.

[0179] Combine Figures 7 to 9 As shown in Tables 1, 6, and 7 above, this embodiment 3 is an industrial lens having 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 from 0.3m to infinity, no defocusing in the temperature range of -40°C to +80°C, and normal operation in various high and low temperature environments.

[0180] Example 4

[0181] Figure 10 This is a schematic structural diagram of an industrial lens according to a fourth embodiment of the present invention;

[0182] Figure 11 Schematic diagram of distortion of the industrial lens of Example 4 of the present utility model when the object distance is 0.3m;

[0183] Figure 12 Schematic diagram of the distortion of the industrial lens of Example 4 of the present invention when the object distance is infinite.

[0184] In Example 4, the first lens L1 is a convex-convex lens with positive optical power, the second lens L2 is a concave-convex 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 negative optical power, the ninth lens L9 is a convex-convex 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 triplet; the sixth lens L6 and the seventh lens L7 form a doublet; the eighth lens L8 and the ninth lens L9 form a doublet; and the tenth lens L10 and the eleventh lens L11 form a doublet. A stop STO is located 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, curvature radius R, thickness d, refractive index Nd and Abbe number Vd of the material.

[0187] Surface serial number Surface type Curvature radius R Thickness d Refractive index Nd Abbe number Vd S1 spherical surface 33.431 4.828 1.801 34.97 S2 spherical surface -172.628 2.937 S3 spherical surface -27.699 3.226 1.770 29.74 S4 spherical surface 19.516 5.714 S5 spherical surface 51.830 5.000 1.883 27.00 S6 spherical surface -13.554 0.772 1.728 28.32 S7 spherical surface 19.309 5.000 1.660 57.35 S8 spherical surface -29.577 T0 S9 spherical surface 177.493 3.483 1.946 17.99 S10 spherical surface -64.638 0.700 1.673 32.17 S11 spherical surface 24.994 T1 S12 spherical surface 14.390 3.696 2.003 19.32 S13 spherical surface 10.966 1.286 1.699 30.05 S14 spherical surface 11.704 3.390 S15 spherical surface 16.353 3.058 1.603 60.60 S16 spherical surface -15.078 3.140 1.620 36.35 S17 spherical surface 249.932 0.400 S18(STO) spherical surface Infinity 23.825 S19 spherical surface Infinity 0.900 1.517 64.20 S20 spherical surface Infinity 0.045 S21(IMA) spherical surface Infinity 0.000

[0188] Table 8

[0189] Table 9 lists the variable spacing values ​​between lens groups of the industrial lens of this embodiment when the object distance changes from 0.3M to infinity.

[0190] Surface number thickness Wide-angle end Telephoto end S8 T0 11.517 2.000 S11 T1 2.083 11.600

[0191] Table 9

[0192] 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 infinite, the aperture FNO is 3.0, the optical distortion is -0.48% to -0.77%, and the relative illumination is 73%.

[0193] Combine Figures 10 to 12 As shown in Tables 1, 8, and 9 above, this fourth embodiment is an industrial lens having 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 from 0.3m to infinity, no defocusing in the temperature range of -40°C to +80°C, and normal operation in various high and low temperature environments.

[0194] The above description is merely a preferred embodiment of the present application and an illustration of the technical principles employed. Those skilled in the art should understand that the scope of the utility model disclosed herein is not limited to the technical solutions formed by the specific combination of the above-mentioned technical features, but also encompasses other technical solutions formed by any combination of the above-mentioned technical features or their equivalents without departing from the concept of the utility model. For example, a technical solution formed by replacing the above-mentioned features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. An industrial lens, characterized in that: The industrial lens comprises, in order from the object side to the image side of the optical axis: a first lens group (G1) with positive focal power, a second lens group (G2) with negative focal power, and a third lens group (G3) with positive focal power, wherein the first lens group (G1) and the third lens group are fixed lens groups, and the second lens group (G2) is a focus adjustment group that moves along the optical axis of the industrial lens; The first lens group (G1) comprises, in order: 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, for a total of five lenses; The second lens group (G2) comprises, in sequence: a sixth lens (L6) with positive optical power and a seventh lens (L7) with negative optical power, a total of two lenses; The third lens group (G3) includes, in order: an eighth lens (L8), a ninth lens (L9), a tenth lens (L10) with positive optical power, and an eleventh lens (L11) with negative optical power, for a total of four lenses; the eighth lens (L8) and the ninth lens (L9) have opposite optical powers; The first lens (L1) to the eleventh lens (L11) include at least three groups of cemented lenses.

2. The industrial lens according to claim 1, characterized in that: The object side surface of the first lens (L1) is a convex surface, 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 a convex surface; and 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 triplet lens, and the sixth lens (L6) and the seventh lens (L7) form a doublet lens.

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 into two groups of doublet lenses; Alternatively, the eighth lens (L8), the ninth lens (L9), the tenth lens (L10), and the eleventh lens (L11) are combined into a single lens and a set of triplet lenses; Alternatively, the ninth lens (L9), the tenth lens (L10) and the eleventh lens (L11) are combined into a four-cemented lens.

7. The industrial lens according to any one of claims 1 to 6, characterized in that: The total length TTL of the optical system of the industrial lens and the total effective focal length FI of the industrial lens when the object distance is 0.3 m 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 when the object distance is 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 FG2 of the second lens group (G2) and the total effective focal length FI of the industrial lens when the object distance is 0.3m satisfy the following relationship: -2.2≤FG2 / FI≤-0.

7.

11. 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 when the object distance is 0.3m satisfy the following relationship: 0.7≤FG3 / FI≤1.

1.

12. 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 when the object distance is 0.3 m and the total effective focal length FII of the industrial lens when the object distance is infinity satisfy the following relationship: 0.97≤FI / FII≤1.

13.

13. 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.

14. 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.

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

91.

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

45.

17. 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.

18. 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.

19. The industrial lens according to any one of claims 1 to 6, characterized in that: The focus movement distance value 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 when the object distance is 0.3m satisfy the following relationship: 0.14≤d_G2 / FI≤0.

5.

20. 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.

21. 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.

22. 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.

23. 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), the effective focal length F9 of the ninth lens (L9), the effective focal length F10 of the tenth lens (L10), 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: -0.3≤(F8+F9+F10+F11) / FG3≤1.

0.

24. The industrial lens according to any one of claims 1 to 6, characterized in that: The refractive index value Nd3 of the third lens (L3) under d light and the central thickness value t3 of the third lens (L3) satisfy the following relationship: 0.3≤Nd3 / t3≤0.

7.

25. 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 when the object distance is 0.3m satisfy the following relationship: 0.2≤|Vd7-Vd6| / FI≤0.

7.

26. 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 when the object distance is 0.3m satisfy the following relationship: 0.5≤|Vd10-Vd11| / FI≤1.

2.

27. The industrial lens according to any one of claims 1 to 6, characterized in that: The total length TTL of the optical system of the industrial lens and the maximum effective light 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.

28. The industrial lens according to claim 1, characterized in that: The industrial lens meets 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, 0.32≤Nd3 / t3≤0.66, 0.23≤|Vd7-Vd6| / FI≤0.66, 0.56≤|Vd10-Vd11| / FI≤1.09, 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 when the object distance is 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 when the object distance is 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 triplet lens consisting of the third lens (L3) to the fifth lens (L5); d23 is the air spacing 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 invention relates to a lens having a focal length of 1 / 4" (L1) and a lens having a focal length of 1 / 4" (L1). The invention further comprises the following components: a focal length of the lens having a focal length of 1 / 4" (L1) and a focal length of the lens having a focal length of 1 / 4" (L1). The invention further comprises the following components: a focal length of the lens having a focal length of 1 / 4" (L1) and a lens having a focal length of 1 / 4" (L1). The invention further comprises the following components:

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