A machine vision lens

Abstract

The application discloses a machine vision lens, which comprises a first lens group and a second lens group in sequence from an object side to an image side along an optical axis. The first lens group is a fixed group, comprising a first lens with positive refractive power, a second lens with negative refractive power, a third lens with negative refractive power, whose object side is convex and image side is concave, a fourth lens with positive refractive power, a fifth lens with positive refractive power, and a sixth lens with negative refractive power. The second lens group is a focusing group, comprising a seventh lens with positive refractive power, an eighth lens with negative refractive power, a ninth lens with positive refractive power, a tenth lens with positive refractive power, and an eleventh lens with positive refractive power, whose object side is convex.

Description

Technical Field

[0001] This application relates to the field of optical components, and more specifically, to a machine vision lens. Background Technology

[0002] In recent years, with the rapid development of optical lens technology, optical lenses have been widely used in more and more fields. Currently, in the field of machine vision, due to the increasing demand for equipment integration, machine vision lenses need to meet the requirements of miniaturization; to improve the accuracy of resolution and judgment, machine vision lenses need to meet the requirements of low distortion; to meet the requirements of a larger recognition range and improve edge field of view brightness, machine vision lenses need to meet the requirements of high relative illumination; in addition, to meet the need for the discrimination of minute details, machine vision lenses also need to meet the requirements of high resolution.

[0003] However, current machine vision lenses on the market are often large in size, making it difficult to meet the requirements of equipment integration. They also generally suffer from problems such as difficulty in achieving both high resolution and low distortion, as well as difficulty in balancing CRA and relative illumination, which affect and limit the application and development of machine vision lenses.

[0004] Therefore, in view of the current development status of machine vision lenses, those skilled in the art are dedicated to developing and designing a machine vision lens with features such as high resolution, high relative illumination, and low distortion, in order to meet the market's ever-increasing demand for such lenses. Summary of the Invention

[0005] This application provides a machine vision lens, which may sequentially include a first lens group and a second lens group along the optical axis from the object side to the image side. The first lens group is a fixed group and may include a first lens with positive optical power; a second lens with negative optical power; a third lens with negative optical power, whose object side is convex and image side is concave; a fourth lens with positive optical power; a fifth lens with positive optical power; and a sixth lens with negative optical power. The second lens group is a focusing group and may include a seventh lens with positive optical power; an eighth lens with negative optical power; a ninth lens with positive optical power; a tenth lens with positive optical power; and an eleventh lens with positive optical power, whose object side is convex.

[0006] In one embodiment, the image-side surface of the first lens is convex.

[0007] In one embodiment, the image-side surface of the second lens is concave.

[0008] In one embodiment, the object-side surface of the fourth lens is convex.

[0009] In one embodiment, the object-side surface of the fifth lens is convex, and the image-side surface is also convex.

[0010] In one embodiment, the object-side surface of the sixth lens is concave, and the image-side surface is also concave.

[0011] In one embodiment, the object-side surface of the seventh lens is convex, and the image-side surface is also convex.

[0012] In one embodiment, the object-side surface of the eighth lens is concave, and the image-side surface is also concave.

[0013] In one embodiment, the object-side surface of the ninth lens is convex, and the image-side surface is also convex.

[0014] In one embodiment, the object-side surface of the tenth lens is convex, and the image-side surface is also convex.

[0015] In one embodiment, the effective focal length FG1 of the first lens group and the total effective focal length F of the machine vision lens can satisfy: 2.0≤FG1 / F≤3.8.

[0016] In one embodiment, the effective focal length FG2 of the second lens group and the total effective focal length F of the machine vision lens can satisfy: 1.0≤FG2 / F≤1.5.

[0017] In one embodiment, the effective focal length FG1 of the first lens group and the effective focal length FG2 of the second lens group can satisfy: 1.5≤FG1 / FG2≤3.1.

[0018] In one embodiment, the radius of curvature R12 of the image-side surface of the first lens and the effective focal length F1 of the first lens can satisfy: -17.5≤R12 / F1<0.

[0019] In one embodiment, the effective focal length F2 of the second lens and the total effective focal length F of the machine vision lens can satisfy: -4.2≤F2 / F<-1.1.

[0020] In one embodiment, the radius of curvature R21 of the object side of the second lens, the radius of curvature R22 of the image side of the second lens, and the total effective focal length F of the machine vision lens can satisfy: -1.3≤(R21-R22) / F≤7.0.

[0021] In one embodiment, the effective focal length F3 of the third lens and the total effective focal length F of the machine vision lens can satisfy: -10.8 ≤ F3 / F < -1.5.

[0022] In one embodiment, the radius of curvature R31 of the object side of the third lens, the radius of curvature R32 of the image side of the third lens, and the total effective focal length F of the machine vision lens can satisfy: 0.1≤(R31-R32) / F≤5.3.

[0023] In one embodiment, the air gap d34 between the third lens and the fourth lens on the optical axis and the combined focal length Fa of the first lens to the third lens can satisfy: -1.2≤d34 / Fa≤0.

[0024] In one embodiment, the radius of curvature R51 of the object side of the fifth lens, the radius of curvature R62 of the image side of the sixth lens, the center thickness d5 of the fifth lens on the optical axis, and the center thickness d6 of the sixth lens on the optical axis can satisfy: 0.1≤(R51-R62) / (d5+d6)≤1.2.

[0025] In one embodiment, the effective focal length F5 of the fifth lens and the total effective focal length F of the machine vision lens can satisfy: 0.3≤F5 / F≤1.2.

[0026] In one embodiment, the effective focal length F6 of the sixth lens and the total effective focal length F of the machine vision lens can satisfy: -0.8≤F6 / F≤-0.2.

[0027] In one embodiment, the refractive index ND5 of the fifth lens, the refractive index ND6 of the sixth lens, the Abbe number VD5 of the fifth lens, and the Abbe number VD6 of the sixth lens may satisfy: 1.5≤ND5≤2.0; 1.5≤ND6≤2.1; 40≤VD5≤70; and 0<VD6≤40.

[0028] In one embodiment, the effective focal length F7 of the seventh lens and the total effective focal length F of the machine vision lens can satisfy: 1.2≤F7 / F≤2.4.

[0029] In one embodiment, the effective focal length F8 of the eighth lens and the total effective focal length F of the machine vision lens can satisfy: -0.9≤F8 / F≤-0.3.

[0030] In one embodiment, the effective focal length F9 of the ninth lens and the total effective focal length F of the machine vision lens can satisfy: 0.6≤F9 / F≤1.9.

[0031] In one embodiment, the combined focal length F89 of the eighth lens and the ninth lens and the total effective focal length F of the machine vision lens can satisfy: -2.3≤F89 / F≤-0.8.

[0032] In one embodiment, the effective focal length F10 of the tenth lens and the total effective focal length F of the machine vision lens can satisfy: 1.0≤F10 / F≤2.0.

[0033] In one embodiment, the refractive index ND10 of the tenth lens may satisfy: 1.7≤ND10≤2.1.

[0034] In one embodiment, the effective focal length F11 of the eleventh lens and the total effective focal length F of the machine vision lens can satisfy: 3.2≤F11 / F≤7.2.

[0035] In one embodiment, the combined focal length Fb of the tenth lens to the eleventh lens and the total effective focal length F of the machine vision lens can satisfy: 0.8≤Fb / F≤1.6.

[0036] In one embodiment, the maximum aperture D of the machine vision lens and the holographic height H of the machine vision lens can satisfy: 1.2≤D / H≤1.9.

[0037] In one embodiment, the distance TTL from the center of the object side of the first lens to the imaging surface of the machine vision lens on the optical axis and the total effective focal length F of the machine vision lens can satisfy: 4.2≤TTL / F≤5.0.

[0038] The machine vision lens of this application includes a first lens group and a second lens group arranged sequentially along the optical axis from the object side to the image side. The first lens group is a fixed group, comprising six lenses, and the second lens group is a focusing group, comprising five lenses. By this lens arrangement and by rationally matching and selecting parameters such as the optical power and surface shape of each lens, the lens can achieve at least one of the following beneficial effects: high resolution, high relative illumination, and low distortion. Attached Figure Description

[0039] Other features, objects, and advantages of this application will become more apparent from the following detailed description of the embodiments, taken in conjunction with the accompanying drawings. In the drawings:

[0040] Figure 1 This is a schematic diagram of the structure of a machine vision lens according to Embodiment 1 of this application;

[0041] Figure 2 It is a relative illumination curve diagram of the machine vision lens according to Embodiment 1 of this application;

[0042] Figure 3 This is a distortion curve diagram of a machine vision lens according to Embodiment 1 of this application;

[0043] Figure 4This is a schematic diagram of the structure of a machine vision lens according to Embodiment 2 of this application;

[0044] Figure 5 This is a relative illumination curve diagram of the machine vision lens according to Embodiment 2 of this application;

[0045] Figure 6 This is a distortion curve diagram of a machine vision lens according to Embodiment 2 of this application;

[0046] Figure 7 This is a schematic diagram of the structure of a machine vision lens according to Embodiment 3 of this application;

[0047] Figure 8 This is a relative illumination curve of the machine vision lens according to Embodiment 3 of this application;

[0048] Figure 9 This is a distortion curve diagram of the machine vision lens according to Embodiment 3 of this application;

[0049] Figure 10 This is a schematic diagram of the structure of a machine vision lens according to Embodiment 4 of this application;

[0050] Figure 11 It is a relative illumination curve diagram of the machine vision lens according to Embodiment 4 of this application; and

[0051] Figure 12 This is a distortion curve diagram of the machine vision lens according to Embodiment 4 of this application. Detailed Implementation

[0052] To facilitate understanding of this application, a more complete description of the application will be provided below with reference to the accompanying drawings. It should be understood that these detailed descriptions are merely illustrative of exemplary embodiments of the application and are not intended to limit the scope of the 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.

[0053] 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 third lens.

[0054] 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.

[0055] 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 side is called the image-side surface of the lens.

[0056] 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.

[0057] 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 a 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.

[0058] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0059] The features, principles and other aspects of this application are described in detail below.

[0060] In an exemplary embodiment, the machine vision lens includes a first lens group and a second lens group, wherein the first lens group is a fixed group and the second lens group is a focusing group, and the first lens group and the second lens group are arranged sequentially from the object side to the image side along the optical axis.

[0061] In an exemplary embodiment, the first lens group may have positive optical power. The first lens group includes, for example, six lenses with optical power, namely a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens. These six lenses are arranged sequentially along the optical axis from the object side to the image side.

[0062] In an exemplary embodiment, the first lens may have positive optical power; the second lens may have negative optical power; the third lens may have negative optical power; the fourth lens may have positive optical power; the fifth lens may have positive optical power; and the sixth lens may have negative optical power.

[0063] The first lens group, as a fixed group in the optical system, can correct aberrations and distortions of the optical system, while also reducing the system's tolerance sensitivity.

[0064] In an exemplary embodiment, the second lens group may have positive optical power. The second lens group includes, for example, five lenses with optical power, namely a seventh lens, an eighth lens, a ninth lens, a tenth lens, and an eleventh lens. These five lenses are arranged sequentially along the optical axis from the object side to the image side.

[0065] In an exemplary embodiment, the seventh lens may have positive optical power; the eighth lens may have negative optical power; the ninth lens may have positive optical power; the tenth lens may have positive optical power; and the eleventh lens may have positive optical power.

[0066] The second lens group, as the focusing group of the optical system, can achieve clear imaging of objects at different object distances on the image plane by moving back and forth along the optical axis. It can correct the aberrations of the system, ensure the consistency of image quality under low distortion conditions, and at the same time correct chromatic aberration to ensure good color reproduction.

[0067] In an exemplary embodiment, the first lens may have positive optical power. The object-side surface of the first lens may be convex, and the image-side surface may also be convex. This configuration of the first lens can introduce a larger negative distortion, which is beneficial for correcting the positive distortion produced by the second and third lenses.

[0068] In an exemplary embodiment, the first lens may have positive optical power. The object-side surface of the first lens may be concave, and the image-side surface may be convex. This arrangement of the first lens can help reduce spherical aberration.

[0069] In an exemplary embodiment, the first lens may have positive optical power. The object-side surface of the first lens may be flat, and the image-side surface may be convex. This arrangement of the first lens can help reduce the occurrence of aberrations.

[0070] In an exemplary embodiment, the second lens may have negative optical power. The object-side surface of the second lens may be convex, and the image-side surface may be concave. By configuring the second lens in this way, on the one hand, the incident angle of off-axis rays on the second lens can be smaller, which can avoid the generation of excessive aberrations; on the other hand, it can help reduce the generation of distortion; and, by using a low Abbe number material, it can help balance the off-axis aberrations of the system and make the outgoing angle of off-axis rays gentler.

[0071] In an exemplary embodiment, the second lens may have negative optical power. The object-side surface of the second lens may be flat, and the image-side surface may be concave. This configuration of the second lens can help reduce aberrations.

[0072] In an exemplary embodiment, the third lens may have negative optical power. The object-side surface of the third lens may be convex, and the image-side surface may be concave. This configuration of the third lens can help reduce distortion; combined with the use of a low Abbe number material, it can help balance the off-axis aberrations of the system and make the outgoing off-axis rays more even.

[0073] In an exemplary embodiment, the fourth lens may have positive optical power. The object-side surface of the fourth lens may be convex, and the image-side surface may also be convex. This arrangement of the fourth lens allows the resulting negative distortion to balance the positive distortion produced by the second and third lenses.

[0074] In an exemplary embodiment, the fourth lens may have positive optical power. The object-side surface of the fourth lens may be convex, and the image-side surface may be planar. This arrangement of the fourth lens can help reduce aberrations.

[0075] In an exemplary embodiment, the fourth lens can be made of a high refractive index material, which helps to reduce the surface curvature of the fourth lens, reduce off-axis aberrations, and lower the design difficulty.

[0076] In an exemplary embodiment, the fifth lens may have positive optical power. The object-side surface of the fifth lens may be convex, and the image-side surface may also be convex.

[0077] In an exemplary embodiment, the sixth lens may have negative optical power. The object-side surface of the sixth lens may be concave, and the image-side surface may also be concave.

[0078] In an exemplary embodiment, the fifth lens and the sixth lens can form a cemented doublet lens, which has a very small optical power for on-axis light rays and a large positive optical power for off-axis light rays. This is beneficial for increasing the exit angle of off-axis light rays after passing through the cemented doublet lens, allowing more off-axis light rays to enter the system, which is beneficial for improving relative illumination.

[0079] In an exemplary embodiment, the fifth and sixth lenses can be made of high refractive index materials, which helps to reduce surface curvature and reduce spherical aberration.

[0080] In an exemplary embodiment, the fifth lens and the sixth lens can be made of high Abbe number and low Abbe number materials, respectively, which helps to reduce chromatic aberration caused by cemented doublets, reduce the difficulty of aberration correction and tolerance sensitivity of the system.

[0081] In an exemplary embodiment, the seventh lens may have positive optical power. The object-side surface of the seventh lens may be convex, and the image-side surface may also be convex. The seventh lens has positive optical power, which, due to the large incident angle and incident height of the incident light, is beneficial for increasing the image area. Through material matching and optical power combination, system aberrations can be balanced.

[0082] In an exemplary embodiment, the eighth lens may have negative optical power. The object-side surface of the eighth lens may be concave, and the image-side surface may be concave.

[0083] In an exemplary embodiment, the ninth lens may have positive optical power. The object-side surface of the ninth lens may be convex, and the image-side surface may also be convex.

[0084] In an exemplary embodiment, the eighth and ninth lenses can form a cemented doublet with negative optical power, increasing the incident height of off-axis rays at the tenth lens, which is beneficial for increasing the image plane. Furthermore, the cemented doublet, through material matching and optical power combination, can balance system aberrations.

[0085] In an exemplary embodiment, the tenth lens may have positive optical power. The object-side surface of the tenth lens may be convex, and the image-side surface may also be convex. The tenth lens has positive optical power, can converge light rays, and its convex object-side and image-side surfaces allow light rays to smoothly enter from the front and further smooth the transition of light paths. The tenth lens may be made of a high refractive index material, which is beneficial for increasing optical power and enhancing the ability to refract light rays.

[0086] In an exemplary embodiment, the eleventh lens may have positive optical power. This can share the optical power of the tenth lens, reducing off-axis aberrations and lowering tolerance sensitivity. The eleventh lens can be made of a high Abbe number material, which helps reduce chromatic aberration and simplifies system aberration correction.

[0087] In an exemplary embodiment, the object-side surface of the eleventh lens can be convex, and the image-side surface can also be convex. This configuration of the eleventh lens can help reduce the generation of distortion.

[0088] In an exemplary embodiment, the object-side surface of the eleventh lens can be convex, and the image-side surface can be concave. This arrangement of the eleventh lens, making it meniscus-shaped, can facilitate the correction of off-axis aberrations.

[0089] In an exemplary embodiment, the object-side surface of the eleventh lens can be convex, and the image-side surface can be planar. This configuration of the eleventh lens can help reduce the generation of aberrations.

[0090] In an exemplary embodiment, the machine vision lens according to this application may further include an aperture stop, which may be located, for example, between the sixth and seventh lenses. It should be noted that the location of the aperture stop disclosed herein is merely an example and not a limitation; in alternative embodiments, the aperture stop may be set at other locations as needed.

[0091] In an exemplary embodiment, the machine vision lens may further include a photosensitive element disposed on the imaging surface. Optionally, the photosensitive element disposed on the imaging surface may be a photocoupled device (CCD) or a complementary metal oxide semiconductor device (CMOS).

[0092] In an exemplary embodiment, each lens included in the machine vision lens can be made of all-glass material. This helps to overcome the problem of focus drift caused by the lens in high and low temperature environments, and helps to meet the requirements for lens use in high and low temperature environments.

[0093] A machine vision lens according to an exemplary embodiment of this application includes a first lens group and a second lens group arranged sequentially along the optical axis from the object side to the image side. The first lens group is a fixed group, comprising six lenses: a first lens with positive optical power, a second lens with negative optical power, a third lens with negative optical power, a fourth lens with positive optical power, a fifth lens with positive optical power, and a sixth lens with negative optical power. The second lens group is a focusing group, comprising five lenses: a seventh lens with positive optical power, an eighth lens with negative optical power, a ninth lens with positive optical power, a tenth lens with positive optical power, and an eleventh lens with positive optical power. The object side of the third lens is convex, and the image side is concave; the object side of the eleventh lens is convex. This lens configuration allows the lens to possess at least one of the following beneficial effects: high resolution, high relative illumination, and low distortion.

[0094] In an exemplary embodiment, the machine vision lens according to this application satisfies: 2.0 ≤ FG1 / F ≤ 3.8, where FG1 is the effective focal length of the first lens group and F is the total effective focal length of the machine vision lens. By controlling the ratio of the effective focal length of the first lens group to the total effective focal length of the machine vision lens within this range, it is possible to achieve and maintain a small distortion while rapidly collecting incident light, reducing field curvature and astigmatism.

[0095] In an exemplary embodiment, the machine vision lens according to this application satisfies: 1.0 ≤ FG2 / F ≤ 1.5, where FG2 is the effective focal length of the second lens group and F is the total effective focal length of the machine vision lens. By controlling the ratio of the effective focal length of the second lens group to the total effective focal length of the machine vision lens within this range, it is beneficial to obtain a larger image plane and achieve higher imaging quality.

[0096] In an exemplary embodiment, the machine vision lens according to this application satisfies: 1.5 ≤ FG1 / FG2 ≤ 3.1, where FG1 is the effective focal length of the first lens group and FG2 is the effective focal length of the second lens group. By controlling the ratio of the effective focal length of the first lens group to the effective focal length of the second lens group within this range, the optical power of the system is dispersed and the image differences generated by the individual lenses are reduced.

[0097] In an exemplary embodiment, the machine vision lens according to this application satisfies: -17.5 ≤ R12 / F1 < 0, where R12 is the radius of curvature of the image-side surface of the first lens, and F1 is the effective focal length of the first lens. By controlling the ratio of the radius of curvature of the image-side surface of the first lens to the effective focal length of the first lens within this range, it is beneficial to make the negative distortion generated by the first lens compensate for the positive distortion generated by the second and third lenses, thereby achieving low distortion.

[0098] In an exemplary embodiment, the machine vision lens according to this application satisfies: -4.2 ≤ F2 / F < -1.1, where F2 is the effective focal length of the second lens and F is the total effective focal length of the machine vision lens. By controlling the ratio of the effective focal length of the second lens to the total effective focal length of the machine vision lens within this range, it is beneficial to make the off-axis light emission angle gentle and the off-axis aberration small, which is beneficial to achieving high image quality.

[0099] In an exemplary embodiment, the machine vision lens according to this application satisfies: -1.3 ≤ (R21 - R22) / F ≤ 7.0, where R21 is the radius of curvature of the object-side surface of the second lens, R22 is the radius of curvature of the image-side surface of the second lens, and F is the total effective focal length of the machine vision lens. By controlling the radius of curvature of the object-side surface of the second lens, the radius of curvature of the image-side surface of the second lens, and the total effective focal length of the machine vision lens to satisfy the condition -1.3 ≤ (R21 - R22) / F ≤ 7.0, combined with the shape of the second lens, off-axis rays can be deflected at a larger angle than on-axis rays, resulting in larger off-axis aberration correction system aberrations, which is beneficial for achieving high image quality.

[0100] In an exemplary embodiment, the machine vision lens according to this application satisfies: -10.8 ≤ F3 / F < -1.5, where F3 is the effective focal length of the third lens and F is the total effective focal length of the machine vision lens. By controlling the ratio of the effective focal length of the third lens to the total effective focal length of the machine vision lens within this range, it is beneficial to make the off-axis light emission angle gentle and the off-axis aberrations small, which is beneficial to achieving high image quality.

[0101] In an exemplary embodiment, the machine vision lens according to this application satisfies: 0.1 ≤ (R31-R32) / F ≤ 5.3, where R31 is the radius of curvature of the object-side surface of the third lens, R32 is the radius of curvature of the image-side surface of the third lens, and F is the total effective focal length of the machine vision lens. By controlling the radius of curvature of the object-side surface of the third lens, the radius of curvature of the image-side surface of the third lens, and the total effective focal length of the machine vision lens to satisfy the condition 0.1 ≤ (R31-R32) / F ≤ 5.3, combined with the shape of the third lens, off-axis rays can be deflected at a larger angle than on-axis rays, resulting in larger off-axis aberration correction system aberrations, which is beneficial for achieving high image quality.

[0102] In an exemplary embodiment, the machine vision lens according to this application satisfies: -1.2 ≤ d34 / Fa ≤ 0, where d34 is the air gap between the third and fourth lenses on the optical axis, and Fa is the combined focal length of the first to third lenses. By controlling the ratio of the air gap between the third and fourth lenses on the optical axis to the combined focal length of the first to third lenses within this range, it is beneficial for the third and fourth lenses to maintain a suitable air gap, keeping the front-end lens away from the aperture stop, which helps to reduce distortion and off-axis aberrations generated by the front-end system and achieve high image quality.

[0103] In an exemplary embodiment, the machine vision lens according to this application satisfies the condition: 0.1 ≤ (R51-R62) / (d5+d6) ≤ 1.2, where R51 is the radius of curvature of the object-side surface of the fifth lens, R62 is the radius of curvature of the image-side surface of the sixth lens, d5 is the center thickness of the fifth lens on the optical axis, and d6 is the center thickness of the sixth lens on the optical axis. By controlling the radius of curvature of the object-side surface of the fifth lens, the radius of curvature of the image-side surface of the sixth lens, the center thickness of the fifth lens on the optical axis, and the center thickness of the sixth lens on the optical axis to satisfy the condition 0.1 ≤ (R51-R62) / (d5+d6) ≤ 1.2, it is beneficial to control the radius and thickness values ​​of the object-side and image-side surfaces of the cemented lens. Combined with the shape of the cemented lens, this allows off-axis rays to be deflected at a larger angle than on-axis rays, enabling more off-axis rays to enter the rear system, which is beneficial for achieving high relative illumination.

[0104] In an exemplary embodiment, the machine vision lens according to this application satisfies the following condition: 0.3 ≤ F5 / F ≤ 1.2, where F5 is the effective focal length of the fifth lens and F is the total effective focal length of the machine vision lens. By controlling the ratio of the effective focal length of the fifth lens to the total effective focal length of the machine vision lens within this range, it is beneficial to correct system aberrations and achieve high image quality.

[0105] In an exemplary embodiment, the machine vision lens according to this application satisfies: -0.8 ≤ F6 / F ≤ -0.2, where F6 is the effective focal length of the sixth lens and F is the total effective focal length of the machine vision lens. By controlling the ratio of the effective focal length of the sixth lens to the total effective focal length of the machine vision lens within this range, it is beneficial to correct system aberrations and achieve high resolution.

[0106] In an exemplary embodiment, the machine vision lens according to this application satisfies 1.5≤ND5≤2.0, 1.5≤ND6≤2.1, 40≤VD5≤70, and 0<VD6≤40, where ND5 is the refractive index of the fifth lens, ND6 is the refractive index of the sixth lens, VD5 is the Abbe number of the fifth lens, and VD6 is the Abbe number of the sixth lens. By controlling the refractive indices of the fifth and sixth lenses within these ranges, the surface curvature of the lenses is reduced, spherical aberration is decreased, which is beneficial for achieving high image quality. By controlling the Abbe numbers of the fifth and sixth lenses within these ranges, the chromatic aberrations generated by the fifth and sixth lenses can compensate for each other, reducing the chromatic aberration and further contributing to high image quality.

[0107] In an exemplary embodiment, the machine vision lens according to this application satisfies: 1.2 ≤ F7 / F ≤ 2.4, where F7 is the effective focal length of the seventh lens and F is the total effective focal length of the machine vision lens. By controlling the ratio of the effective focal length of the seventh lens to the total effective focal length of the machine vision lens within this range, positive astigmatism and positive field curvature correction system aberrations can be introduced, which is beneficial for achieving high image quality.

[0108] In an exemplary embodiment, the machine vision lens according to this application satisfies: -0.9 ≤ F8 / F ≤ -0.3, where F8 is the effective focal length of the eighth lens and F is the total effective focal length of the machine vision lens. By controlling the ratio of the effective focal length of the eighth lens to the total effective focal length of the machine vision lens within this range, it is beneficial to correct system aberrations and achieve high image quality.

[0109] In an exemplary embodiment, the machine vision lens according to this application satisfies: 0.6 ≤ F9 / F ≤ 1.9, where F9 is the effective focal length of the ninth lens and F is the total effective focal length of the machine vision lens. By controlling the ratio of the effective focal length of the ninth lens to the total effective focal length of the machine vision lens within this range, it is beneficial to correct system aberrations and achieve high image quality.

[0110] In an exemplary embodiment, the machine vision lens according to this application satisfies: -2.3 ≤ F89 / F ≤ -0.8, where F89 is the combined focal length of the eighth and ninth lenses, and F is the total effective focal length of the machine vision lens. By controlling the ratio of the combined focal length of the eighth and ninth lenses to the total effective focal length of the machine vision lens within this range, it is beneficial to increase the incident height of off-axis rays at the tenth lens, which is beneficial to increasing the target surface area.

[0111] In an exemplary embodiment, the machine vision lens according to this application satisfies: 1.0 ≤ F10 / F ≤ 2.0, where F10 is the effective focal length of the tenth lens and F is the total effective focal length of the machine vision lens. By controlling the ratio of the effective focal length of the tenth lens to the total effective focal length of the machine vision lens within this range, positive field curvature correction system aberrations can be introduced, which is beneficial for achieving high image quality.

[0112] In an exemplary embodiment, the machine vision lens according to this application satisfies: 1.7 ≤ ND10 ≤ 2.1, where ND10 is the refractive index of the tenth lens. By controlling the refractive index of the tenth lens within this range, the surface curvature of the lens is reduced, the generation of off-axis aberrations is decreased, which is beneficial to achieving high image quality.

[0113] In an exemplary embodiment, the machine vision lens according to this application satisfies: 3.2 ≤ F11 / F ≤ 7.2, where F11 is the effective focal length of the eleventh lens and F is the total effective focal length of the machine vision lens. By controlling the ratio of the effective focal length of the eleventh lens to the total effective focal length of the machine vision lens within this range, the focal length of the eleventh lens can be reasonably set, thus sharing the optical power of the tenth lens, reducing the surface curvature of the tenth lens, reducing the generation of off-axis aberrations, and contributing to achieving high image quality.

[0114] In an exemplary embodiment, the machine vision lens according to this application satisfies the following condition: 0.8 ≤ Fb / F ≤ 1.6, where Fb is the combined focal length of the tenth to eleventh lenses, and F is the total effective focal length of the machine vision lens. By controlling the ratio of the combined focal length of the tenth to eleventh lenses to the total effective focal length of the machine vision lens within this range, the angle of the emitted principal ray can be made gentler, which is beneficial for reducing CRA (Collateral Radiation Amplitude).

[0115] In an exemplary embodiment, the machine vision lens according to this application satisfies the following condition: 1.2 ≤ D / H ≤ 1.9, where D is the maximum aperture of the machine vision lens and H is the full image height of the machine vision lens. By controlling the ratio of the maximum aperture to the full image height of the machine vision lens within this range, the maximum aperture of the system can be reasonably controlled under a certain system image height, resulting in a smaller maximum aperture, which is beneficial for miniaturization.

[0116] In an exemplary embodiment, the machine vision lens according to this application satisfies: 4.2 ≤ TTL / F ≤ 5.0, where TTL is the distance on the optical axis from the center of the object-side surface of the first lens to the imaging surface of the machine vision lens, and F is the total effective focal length of the machine vision lens. By controlling the ratio of the distance on the optical axis from the center of the object-side surface of the first lens to the imaging surface of the machine vision lens to the total effective focal length of the machine vision lens within this range, the total optical length of the system is reasonably controlled under a certain system focal length value, resulting in a smaller total optical length, which is beneficial for miniaturization.

[0117] In an exemplary embodiment, the machine vision lens of this application may, as needed, further include a filter and / or protective glass disposed between the second lens group and the imaging surface (between the eleventh lens and the imaging surface). The filter can filter light with a specific wavelength, and the protective glass can prevent damage to the image-side components (e.g., chips) of the machine vision lens.

[0118] The machine vision lens according to the embodiments of this application can employ multiple lenses, such as the eleven lenses described above. By rationally setting parameters such as the optical power, surface shape, radius of curvature, refractive index, and Abbe number of each lens, the lens can achieve at least one of the following beneficial effects: high resolution, high relative illumination, and low distortion.

[0119] The machine vision lens according to the embodiments of this application can achieve a high resolution of 28 megapixels; can achieve a high relative illumination, with a relative illumination of more than 82% across the entire field of view; and can have a low distortion feature, with an absolute distortion value ≤0.5%.

[0120] However, those skilled in the art will understand that the number of lenses constituting the lens can be varied to obtain the various results and advantages described herein without departing from the technical solutions claimed in this application. For example, although eleven lenses have been described as an example in the embodiments, the machine vision lens is not limited to including eleven lenses. If desired, the machine vision lens may also include other numbers of lenses. Specific embodiments of the machine vision lens applicable to the above embodiments are further described below with reference to the accompanying drawings.

[0121] Example 1

[0122] Figure 1 This is a schematic diagram of the structure of a machine vision lens according to Embodiment 1 of this application, as shown below. Figure 1 Describes a machine vision lens according to Embodiment 1 of this application.

[0123] like Figure 1As shown, the machine vision lens, arranged sequentially from the object side to the image side along the optical axis, includes a first lens group G1, an aperture S, a second lens group G2, a filter and / or protective glass CG, and an imaging surface IMA. The first lens group G1 includes a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, and a sixth lens L6 arranged sequentially from the object side to the image side along the optical axis. The second lens group G2 includes a seventh lens L7, an eighth lens L8, a ninth lens L9, a tenth lens L10, and an eleventh lens L11 arranged sequentially from the object side to the image side along the optical axis. The fifth lens L5 and the sixth lens L6 are cemented together to form a cemented doublet lens; the eighth lens L8 and the ninth lens L9 are cemented together to form a cemented doublet lens.

[0124] In this embodiment, the first lens L1 has positive optical power, with its object-side surface S1 being convex and its image-side surface S2 being convex. The second lens L2 has negative optical power, with its object-side surface S3 being convex and its image-side surface S4 being concave. The third lens L3 has negative optical power, with its object-side surface S5 being convex and its image-side surface S6 being concave. The fourth lens L4 has positive optical power, with its object-side surface S7 being convex and its image-side surface S8 being convex. The fifth lens L5 has positive optical power, with its object-side surface S9 being convex and its image-side surface S10 being convex. The sixth lens L6 has negative optical power, with its object-side surface S10 being concave and its image-side surface S11 being concave. The seventh lens L7 has positive optical power, with its object-side surface S13 being convex and its image-side surface S14 being convex. The eighth lens L8 has negative optical power, with its object-side surface S15 being concave and its image-side surface S16 being concave. The ninth lens L9 has positive optical power, with its object-side surface S16 being convex and its image-side surface S17 being convex. The tenth lens L10 has positive optical power, with its object-side surface S18 being convex and its image-side surface S19 being convex. The eleventh lens L11 has positive optical power, with its object-side surface S20 being convex and its image-side surface S21 being convex.

[0125] In this embodiment, the aperture stop STO of the machine vision lens is positioned between the sixth lens L6 and the seventh lens L7.

[0126] In this embodiment, the filter and / or protective glass CG located between the second lens group G2 and the imaging surface IMA has an object-side surface S22 and an image-side surface S23. Light from the object passes sequentially through each surface S1 to S23 and is finally imaged on the imaging surface, wherein an image sensor chip IMA may be disposed at the imaging surface.

[0127] Table 1 shows the radius of curvature R, thickness d / distance T, refractive index N, and Abbe number Vd of each lens in the machine vision lens of Embodiment 1. Regarding "thickness d / distance T", it should be understood that the thickness d / distance T in the row containing S1 is the center thickness of the first lens L1, the thickness d / distance T in the row containing S2 is the air gap distance between the first lens L1 and the second lens L2, the thickness d / distance T in the row containing S3 is the center thickness of the second lens L2, and so on.

[0128]

[0129] Table 1

[0130] Figure 2 The relative illumination curve of the machine vision lens in Example 1 is shown. Figure 3 The distortion curve of the machine vision lens in Embodiment 1 is shown. According to... Figure 2 and Figure 3 It can be seen that the machine vision lens given in Example 1 can achieve the effects of high relative illumination and low distortion.

[0131] Example 2

[0132] Figure 4 A schematic diagram of the structure of a machine vision lens according to Embodiment 2 of this application is shown below, with reference to the following. Figure 4 This paper describes a machine vision lens according to Embodiment 2 of this application. For the sake of brevity, descriptions similar to those in Embodiment 1 will be omitted in this embodiment and the following embodiments.

[0133] like Figure 4 As shown, the machine vision lens, arranged sequentially from the object side to the image side along the optical axis, includes a first lens group G1, an aperture S, a second lens group G2, a filter and / or protective glass CG, and an imaging surface IMA. The first lens group G1 includes a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, and a sixth lens L6 arranged sequentially from the object side to the image side along the optical axis. The second lens group G2 includes a seventh lens L7, an eighth lens L8, a ninth lens L9, a tenth lens L10, and an eleventh lens L11 arranged sequentially from the object side to the image side along the optical axis. The fifth lens L5 and the sixth lens L6 are cemented together to form a cemented doublet lens; the eighth lens L8 and the ninth lens L9 are cemented together to form a cemented doublet lens.

[0134] In this embodiment, the first lens L1 has positive optical power, with its object-side surface S1 being convex and its image-side surface S2 being convex. The second lens L2 has negative optical power, with its object-side surface S3 being convex and its image-side surface S4 being concave. The third lens L3 has negative optical power, with its object-side surface S5 being convex and its image-side surface S6 being concave. The fourth lens L4 has positive optical power, with its object-side surface S7 being convex and its image-side surface S8 being convex. The fifth lens L5 has positive optical power, with its object-side surface S9 being convex and its image-side surface S10 being convex. The sixth lens L6 has negative optical power, with its object-side surface S10 being concave and its image-side surface S11 being concave. The seventh lens L7 has positive optical power, with its object-side surface S13 being convex and its image-side surface S14 being convex. The eighth lens L8 has negative optical power, with its object-side surface S15 being concave and its image-side surface S16 being concave. The ninth lens L9 has positive optical power, with its object-side surface S16 being convex and its image-side surface S17 being convex. The tenth lens L10 has positive optical power, with its object-side surface S18 being convex and its image-side surface S19 being convex. The eleventh lens L11 has positive optical power, with its object-side surface S20 being convex and its image-side surface S21 being convex.

[0135] In this embodiment, the aperture stop STO of the machine vision lens is positioned between the sixth lens L6 and the seventh lens L7.

[0136] In this embodiment, the filter and / or protective glass CG located between the second lens group G2 and the imaging surface IMA has an object-side surface S22 and an image-side surface S23. Light from the object passes sequentially through each surface S1 to S23 and is finally imaged on the imaging surface, wherein an image sensor chip IMA may be disposed at the imaging surface.

[0137] Table 2 shows the radius of curvature R, thickness d / distance T, refractive index N, and Abbe number Vd of each lens in the machine vision lens of Example 2.

[0138]

[0139]

[0140] Table 2

[0141] Figure 5 The relative illumination curve of the machine vision lens in Example 2 is shown. Figure 6 The distortion curve of the machine vision lens in Example 2 is shown. According to... Figure 5 and Figure 6 It can be seen that the machine vision lens given in Example 2 can achieve the effects of high relative illumination and low distortion.

[0142] Example 3

[0143] Figure 7A schematic diagram of the structure of a machine vision lens according to Embodiment 3 of this application is shown below, with reference to the following. Figure 7 Describes a machine vision lens according to Embodiment 3 of this application.

[0144] like Figure 7 As shown, the machine vision lens, arranged sequentially from the object side to the image side along the optical axis, includes a first lens group G1, an aperture S, a second lens group G2, a filter and / or protective glass CG, and an imaging surface IMA. The first lens group G1 includes a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, and a sixth lens L6 arranged sequentially from the object side to the image side along the optical axis. The second lens group G2 includes a seventh lens L7, an eighth lens L8, a ninth lens L9, a tenth lens L10, and an eleventh lens L11 arranged sequentially from the object side to the image side along the optical axis. The fifth lens L5 and the sixth lens L6 are cemented together to form a cemented doublet lens; the eighth lens L8 and the ninth lens L9 are cemented together to form a cemented doublet lens.

[0145] In this embodiment, the first lens L1 has positive optical power, with its object-side surface S1 being concave and its image-side surface S2 being convex. The second lens L2 has negative optical power, with its object-side surface S3 being convex and its image-side surface S4 being concave. The third lens L3 has negative optical power, with its object-side surface S5 being convex and its image-side surface S6 being concave. The fourth lens L4 has positive optical power, with its object-side surface S7 being convex and its image-side surface S8 being convex. The fifth lens L5 has positive optical power, with its object-side surface S9 being convex and its image-side surface S10 being convex. The sixth lens L6 has negative optical power, with its object-side surface S10 being concave and its image-side surface S11 being concave. The seventh lens L7 has positive optical power, with its object-side surface S13 being convex and its image-side surface S14 being convex. The eighth lens L8 has negative optical power, with its object-side surface S15 being concave and its image-side surface S16 being concave. The ninth lens L9 has positive optical power, with its object-side surface S16 being convex and its image-side surface S17 being convex. The tenth lens L10 has positive optical power, with its object-side surface S18 being convex and its image-side surface S19 being convex. The eleventh lens L11 has positive optical power, with its object-side surface S20 being convex and its image-side surface S21 being concave.

[0146] In this embodiment, the aperture stop STO of the machine vision lens is positioned between the sixth lens L6 and the seventh lens L7.

[0147] In this embodiment, the filter and / or protective glass CG located between the second lens group G2 and the imaging surface IMA has an object-side surface S22 and an image-side surface S23. Light from the object passes sequentially through each surface S1 to S23 and is finally imaged on the imaging surface, wherein an image sensor chip IMA may be disposed at the imaging surface.

[0148] Table 3 shows the radius of curvature R, thickness d / distance T, refractive index N, and Abbe number Vd of each lens in the machine vision lens of Example 3.

[0149]

[0150] Table 3

[0151] Figure 8 The relative illumination curve of the machine vision lens in Example 3 is shown. Figure 9 The distortion curve of the machine vision lens in Example 3 is shown. According to... Figure 8 and Figure 9 It can be seen that the machine vision lens given in Example 3 can achieve the effects of high relative illumination and low distortion.

[0152] Example 4

[0153] Figure 10 A schematic diagram of the structure of a machine vision lens according to Embodiment 4 of this application is shown below, with reference to... Figure 10 Describes a machine vision lens according to Embodiment 4 of this application.

[0154] like Figure 10 As shown, the machine vision lens, arranged sequentially from the object side to the image side along the optical axis, includes a first lens group G1, an aperture S, a second lens group G2, a filter and / or protective glass CG, and an imaging surface IMA. The first lens group G1 includes a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, and a sixth lens L6 arranged sequentially from the object side to the image side along the optical axis. The second lens group G2 includes a seventh lens L7, an eighth lens L8, a ninth lens L9, a tenth lens L10, and an eleventh lens L11 arranged sequentially from the object side to the image side along the optical axis. The fifth lens L5 and the sixth lens L6 are cemented together to form a cemented doublet lens; the eighth lens L8 and the ninth lens L9 are cemented together to form a cemented doublet lens.

[0155] In this embodiment, the first lens L1 has positive optical power, with its object-side surface S1 being convex and its image-side surface S2 being convex. The second lens L2 has negative optical power, with its object-side surface S3 being planar and its image-side surface S4 being concave. The third lens L3 has negative optical power, with its object-side surface S5 being convex and its image-side surface S6 being concave. The fourth lens L4 has positive optical power, with its object-side surface S7 being convex and its image-side surface S8 being planar. The fifth lens L5 has positive optical power, with its object-side surface S9 being convex and its image-side surface S10 being convex. The sixth lens L6 has negative optical power, with its object-side surface S10 being concave and its image-side surface S11 being concave. The seventh lens L7 has positive optical power, with its object-side surface S13 being convex and its image-side surface S14 being convex. The eighth lens L8 has negative optical power, with its object-side surface S15 being concave and its image-side surface S16 being concave. The ninth lens L9 has positive optical power, with its object-side surface S16 being convex and its image-side surface S17 being convex. The tenth lens L10 has positive optical power, with its object-side surface S18 being convex and its image-side surface S19 being convex. The eleventh lens L11 has positive optical power, with its object-side surface S20 being convex and its image-side surface S21 being flat.

[0156] In this embodiment, the aperture stop STO of the machine vision lens is positioned between the sixth lens L6 and the seventh lens L7.

[0157] In this embodiment, the filter and / or protective glass CG located between the second lens group G2 and the imaging surface IMA has an object-side surface S22 and an image-side surface S23. Light from the object passes sequentially through each surface S1 to S23 and is finally imaged on the imaging surface, wherein an image sensor chip IMA may be disposed at the imaging surface.

[0158] Table 4 shows the radius of curvature R, thickness d / distance T, refractive index N, and Abbe number Vd of each lens in the machine vision lens of Example 4.

[0159]

[0160]

[0161] Table 4

[0162] Figure 11 The relative illumination curve of the machine vision lens in Example 4 is shown. Figure 12 The distortion curve of the machine vision lens in Example 4 is shown. According to... Figure 11 and Figure 12 It can be seen that the machine vision lens given in Example 4 can achieve the effects of high relative illumination and low distortion.

[0163] In summary, Examples 1 to 4 satisfy the relationships shown in Table 5 below.

[0164]

[0165]

[0166] Table 5

[0167] This application also provides an electronic device that may include a machine vision lens according to the above embodiments of this application and an imaging element for converting the optical image formed by the machine vision lens into an electrical signal.

[0168] 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. A machine vision lens, characterized in that, Along the optical axis, from the object side to the image side, there are sequentially a first lens group and a second lens group, wherein... The first lens group is a fixed group, including a first lens with positive optical power; a second lens with negative optical power; a third lens with negative optical power, the object side of which is convex and the image side is concave; a fourth lens with positive optical power; a fifth lens with positive optical power; and a sixth lens with negative optical power. The second lens group is a focusing group, including a seventh lens with positive optical power; an eighth lens with negative optical power; a ninth lens with positive optical power; a tenth lens with positive optical power; and an eleventh lens with positive optical power, the object side of which is convex. The number of lenses with optical power in the machine vision lens is eleven; and The effective focal length FG1 of the first lens group and the total effective focal length F of the machine vision lens satisfy: 2.0≤FG1 / F≤3.

8.

2. The machine vision lens according to claim 1, characterized in that, The image-side surface of the first lens is convex.

3. The machine vision lens according to claim 1, characterized in that, The image-side surface of the second lens is concave.

4. The machine vision lens according to claim 1, characterized in that, The object-side surface of the fourth lens is convex.

5. The machine vision lens according to claim 1, characterized in that, The object-side surface of the fifth lens is convex, and the image-side surface is also convex.

6. The machine vision lens according to claim 1, characterized in that, The object-side surface of the sixth lens is concave, and the image-side surface is also concave.

7. The machine vision lens according to claim 1, characterized in that, The object-side surface of the seventh lens is convex, and the image-side surface is also convex.

8. The machine vision lens according to claim 1, characterized in that, The object-side surface of the eighth lens is concave, and the image-side surface is also concave.

9. The machine vision lens according to claim 1, characterized in that, The object-side surface of the ninth lens is convex, and the image-side surface is also convex.

10. The machine vision lens according to claim 1, characterized in that, The object-side surface of the tenth lens is convex, and the image-side surface is also convex.

11. The machine vision lens according to any one of claims 1 to 10, characterized in that, The effective focal length FG2 of the second lens group and the total effective focal length F of the machine vision lens satisfy: 1.0≤FG2 / F≤1.

5.

12. The machine vision lens according to any one of claims 1 to 10, characterized in that, The effective focal length FG1 of the first lens group and the effective focal length FG2 of the second lens group satisfy: 1.5≤FG1 / FG2≤3.

1.

13. The machine vision lens according to any one of claims 1 to 10, characterized in that, The radius of curvature R12 of the image side surface of the first lens and the effective focal length F1 of the first lens satisfy: -17.5≤R12 / F1<0.

14. The machine vision lens according to any one of claims 1 to 10, characterized in that, The effective focal length F2 of the second lens and the total effective focal length F of the machine vision lens satisfy the condition: -4.2 ≤ F2 / F < -1.

1.

15. The machine vision lens according to any one of claims 1 to 10, characterized in that, The radius of curvature R21 of the object side of the second lens, the radius of curvature R22 of the image side of the second lens, and the total effective focal length F of the machine vision lens satisfy: -1.3≤(R21-R22) / F≤7.

0.

16. The machine vision lens according to any one of claims 1 to 10, characterized in that, The effective focal length F3 of the third lens and the total effective focal length F of the machine vision lens satisfy the condition: -10.8 ≤ F3 / F < -1.

5.

17. The machine vision lens according to any one of claims 1 to 10, characterized in that, The radius of curvature R31 of the object side of the third lens, the radius of curvature R32 of the image side of the third lens, and the total effective focal length F of the machine vision lens satisfy: 0.1≤(R31-R32) / F≤5.

3.

18. The machine vision lens according to any one of claims 1 to 10, characterized in that, The air gap d34 between the third lens and the fourth lens on the optical axis and the combined focal length Fa of the first lens to the third lens satisfy: -1.2≤d34 / Fa≤0.

19. The machine vision lens according to any one of claims 1 to 10, characterized in that, The radius of curvature R51 of the object side of the fifth lens, the radius of curvature R62 of the image side of the sixth lens, the center thickness d5 of the fifth lens on the optical axis, and the center thickness d6 of the sixth lens on the optical axis satisfy: 0.1≤(R51-R62) / (d5+d6)≤1.

2.

20. The machine vision lens according to any one of claims 1 to 10, characterized in that, The effective focal length F5 of the fifth lens and the total effective focal length F of the machine vision lens satisfy the condition: 0.3≤F5 / F≤1.

2.

21. The machine vision lens according to any one of claims 1 to 10, characterized in that, The effective focal length F6 of the sixth lens and the total effective focal length F of the machine vision lens satisfy the following condition: -0.8≤F6 / F≤-0.

2.

22. The machine vision lens according to any one of claims 1 to 10, characterized in that, The refractive index ND5 of the fifth lens, the refractive index ND6 of the sixth lens, the Abbe number VD5 of the fifth lens, and the Abbe number VD6 of the sixth lens satisfy the following: 1.5≤ND5≤2.0; 1.5≤ND6≤2.1; 40≤VD5≤70; and 0 < VD6 ≤ 40.

23. The machine vision lens according to any one of claims 1 to 10, characterized in that, The effective focal length F7 of the seventh lens and the total effective focal length F of the machine vision lens satisfy the following condition: 1.2≤F7 / F≤2.

4.

24. The machine vision lens according to any one of claims 1 to 10, characterized in that, The effective focal length F8 of the eighth lens and the total effective focal length F of the machine vision lens satisfy the following condition: -0.9≤F8 / F≤-0.

3.

25. The machine vision lens according to any one of claims 1 to 10, characterized in that, The effective focal length F9 of the ninth lens and the total effective focal length F of the machine vision lens satisfy the condition: 0.6≤F9 / F≤1.

9.

26. The machine vision lens according to any one of claims 1 to 10, characterized in that, The combined focal length F89 of the eighth lens and the ninth lens and the total effective focal length F of the machine vision lens satisfy the following condition: -2.3≤F89 / F≤-0.

8.

27. The machine vision lens according to any one of claims 1 to 10, characterized in that, The effective focal length F10 of the tenth lens and the total effective focal length F of the machine vision lens satisfy the following condition: 1.0≤F10 / F≤2.

0.

28. The machine vision lens according to any one of claims 1 to 10, characterized in that, The refractive index ND10 of the tenth lens satisfies: 1.7≤ND10≤2.

1.

29. The machine vision lens according to any one of claims 1 to 10, characterized in that, The effective focal length F11 of the eleventh lens and the total effective focal length F of the machine vision lens satisfy the following condition: 3.2≤F11 / F≤7.

2.

30. The machine vision lens according to any one of claims 1 to 10, characterized in that, The combined focal length Fb of the tenth lens to the eleventh lens and the total effective focal length F of the machine vision lens satisfy the following condition: 0.8 ≤ Fb / F ≤ 1.

6.

31. The machine vision lens according to any one of claims 1 to 10, characterized in that, The maximum aperture D of the machine vision lens and the holographic height H of the machine vision lens satisfy the following condition: 1.2 ≤ D / H ≤ 1.

9.

32. The machine vision lens according to any one of claims 1 to 10, characterized in that, The distance TTL from the center of the object side of the first lens to the imaging surface of the machine vision lens on the optical axis satisfies the following condition: 4.2≤TTL / F≤5.0.

Images