A miniaturized industrial lens with low distortion and high resolution

Abstract

The present invention discloses a miniaturized industrial lens with low distortion and high resolution, which comprises, from the object side to the image side along the optical axis, a first lens L1, a second lens L2, a third lens L3, a stop C, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, and a ninth lens L9, wherein the first lens L1, the second lens L2, and the third lens L3 constitute a front lens group, and the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, the eighth lens L8, and the ninth lens L9 constitute a rear lens group. The industrial lens has the characteristics of miniaturization, low distortion, and high resolution.

Description

Technical Field

[0001] The invention belongs to the technical field of industrial optical lenses, and in particular relates to a miniaturized industrial lens with low distortion and high resolution. Background Art

[0002] In industrial automation systems, industrial lenses, as the front-end components for image data acquisition, directly determine the accuracy of information acquisition.

[0003] Given the special requirements of industrial applications, industrial lenses must have performance that exceeds that of ordinary lenses, including lower imaging distortion, higher image clarity, and more compact size.

[0004] However, the current industrial lenses on the market are still insufficient in meeting these requirements. The market demand for small industrial lenses that can provide smaller imaging distortion and higher clarity is increasing.

[0005] Therefore, developing an industrial lens that can fully meet the above requirements has become an urgent task to be solved. Summary of the invention

[0006] In view of the deficiencies in the prior art, the present invention provides a miniaturized industrial lens with low distortion and high resolution, which has the performance of small size, low distortion and high resolution.

[0007] To achieve the above-mentioned object, the present invention provides the following technical solution: a small-sized industrial lens with low distortion and high resolution, wherein the industrial lens comprises, in order from the object side to the image side along the optical axis: a first lens L1, a second lens L2, a third lens L3, an aperture C, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, and a ninth lens L9, wherein the first lens L1, the second lens L2, and the third lens L3 constitute a front lens group, and the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, the eighth lens L8, and the ninth lens L9 constitute a rear lens group,

[0008] The first lens L1 is a negative meniscus lens with its concave surface facing the object;

[0009] The second lens L2 is a double concave negative lens;

[0010] The third lens L3 is a biconvex positive lens;

[0011] The fourth lens L4 is a biconvex positive lens;

[0012] The fifth lens L5 is a negative meniscus lens with a concave surface facing the image side;

[0013] The sixth lens L6 is a biconvex positive lens or a meniscus positive lens with the convex surface facing the object;

[0014] The seventh lens L7 is a biconcave negative lens or a meniscus negative lens with a concave surface facing the object;

[0015] The eighth lens L8 is a biconvex positive lens or a meniscus positive lens with the convex surface facing the image side;

[0016] The ninth lens L9 is a negative meniscus lens with a concave surface facing the image side;

[0017] The second lens L2 and the third lens L3 are closely connected to form a first cemented group, the fourth lens L4 and the fifth lens L5 are closely connected to form a second cemented group; the sixth lens L6 and the seventh lens L7 are closely connected to form a third cemented group;

[0018] The total focal length of the optical system is f, and the focal length of the front lens is f u1 , the focal length of the rear lens is f u1 , satisfying the relationship: 5.5≤|f u1 / f|≤9.0,1.5≤|f u2 / f|≤2.0.

[0019] As a specific implementation manner, the maximum field of view FOV of the industrial lens and the chief ray angle CRA of the industrial lens satisfy the following relationship: 2.5≤FOV / CRA≤3.0.

[0020] As a specific implementation, the ninth lens L9 further satisfies the following condition: -0.3≤(R 91 -R 92 ) / (R 91 +R 92 )≤-0.1, where R 91 The curvature radius of the ninth lens L9 on the object side, R 92 It represents the curvature radius of the image surface side of the ninth lens L9.

[0021] As a specific implementation manner, the refractive index N of the fifth lens L5 is d5 Satisfy N d5 ≥1.8.

[0022] As a specific implementation, the total optical length of the optical system is TTL, and the total focal length of the optical system is f, and both satisfy the following condition: TTL / f≤3.5.

[0023] Specifically, TTL≤55.23mm, 15.98mm≤f≤16.24 mm.

[0024] As a specific implementation manner, when the sixth lens L6 and the eighth lens L8 are both double convex positive lenses, and the seventh lens L7 is a double concave negative lens, the air distance from the first lens L1 to the second lens L2 is 9.8310 mm; the air distance from the third lens L3 to the aperture C is 3.5444 mm; the air distance from the aperture C to the fourth lens L4 is 1.5069 mm; the air distance from the fifth lens L5 to the sixth lens L6 is 0.1000 mm; the air distance from the seventh lens L7 to the eighth lens L8 is 2.0071 mm; the air distance from the eighth lens L8 to the ninth lens L9 is 0.5200 mm; and the air distance from the ninth lens L9 to the image plane IMG is 12.9548 mm.

[0025] As a specific implementation manner, when the sixth lens L6 adopts a double convex positive lens, the seventh lens L7 adopts a double concave negative lens, and the eighth lens L8 adopts a meniscus positive lens with the convex surface facing the image side, the air distance from the first lens L1 to the second lens L2 is 11.6072 mm; the air distance from the third lens L3 to the aperture C is 4.1871 mm; the air distance from the aperture C to the fourth lens L4 is 1.2919 mm; the air distance from the fifth lens L5 to the sixth lens L6 is 0.1000 mm; the air distance from the seventh lens L7 to the eighth lens L8 is 2.0845 mm; the air distance from the eighth lens L8 to the ninth lens L9 is 0.6661 mm; and the air distance from the ninth lens L9 to the image plane IMG is 11.3633 mm.

[0026] As a specific implementation manner, when the sixth lens L6 adopts a positive meniscus lens with a convex surface facing the object, the seventh lens L7 adopts a negative meniscus lens with a concave surface facing the object, and the eighth lens L8 adopts a double convex positive lens, the air distance from the first lens L1 to the second lens L2 is 9.6722 mm; the air distance from the third lens L3 to the aperture C is 3.4460 mm; the air distance from the aperture C to the fourth lens L4 is 1.8777 mm; the air distance from the fifth lens L5 to the sixth lens L6 is 0.1000 mm; the air distance from the seventh lens L7 to the eighth lens L8 is 1.9988 mm; the air distance from the eighth lens L8 to the ninth lens L9 is 0.5200 mm; and the air distance from the ninth lens L9 to the image plane IMG is 12.6661 mm.

[0027] Compared with the prior art, the present invention provides a miniaturized industrial lens with low distortion and high resolution, which has the following beneficial effects:

[0028] 1) The present invention reasonably allocates the positions of the lenses in the optical system, thereby achieving low distortion requirements while maintaining the optical performance of the lens;

[0029] 2) The present invention optimizes the optical performance, reduces the chromatic aberration of the imaging, and realizes the miniaturization of the lens by introducing three groups of cemented lenses into the imaging system;

[0030] 3) The present invention ensures the clarity of the image by reasonably allocating the positions of lenses with different optical powers;

[0031] 4) The requirement of high resolution is achieved by reasonably allocating the proportion of the optical power of the front and rear lens groups to the optical power of the entire lens. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is the optical path diagram of the small-sized industrial lens with low distortion and high resolution in Example 1;

[0033] Figure 2 The MTF curve of the low-distortion and high-resolution miniaturized industrial lens in the visible light band in Example 1;

[0034] Figure 3 The field curvature and distortion diagram of the small industrial lens with low distortion and high resolution in the visible light band in Example 1;

[0035] Figure 4 The axial aberration curve of the low-distortion and high-resolution miniaturized industrial lens in the visible light band in Example 1;

[0036] Figure 5 The vertical axis chromatic aberration curve of the low-distortion and high-resolution miniaturized industrial lens in the visible light band in Example 1;

[0037] Figure 6 This is the optical path diagram of the small-sized industrial lens with low distortion and high resolution in Example 2;

[0038] Figure 7 This is an MTF curve diagram of the visible light band of the small industrial lens with low distortion and high resolution in Example 2;

[0039] Figure 8 The field curvature and distortion diagram of the low-distortion and high-resolution miniaturized industrial lens in the visible light band in Example 2;

[0040] Fig. 9 The axial aberration curve of the low-distortion and high-resolution miniaturized industrial lens in the visible light band in Example 2;

[0041] Fig.10 The vertical axis chromatic aberration curve of the low-distortion and high-resolution miniaturized industrial lens in the visible light band in Example 2;

[0042] Fig.11 This is the optical path diagram of the small-sized industrial lens with low distortion and high resolution in Example 3;

[0043] Fig.12 The MTF curve of the low-distortion and high-resolution miniaturized industrial lens in the visible light band in Example 3;

[0044] Fig.13 The field curvature and distortion diagram of the small industrial lens with low distortion and high resolution in the visible light band in Example 3;

[0045] Fig.14 The axial aberration curve of the low-distortion and high-resolution miniaturized industrial lens in the visible light band in Example 3;

[0046] Fig.15 This is a vertical axis chromatic aberration curve of the low-distortion and high-resolution miniaturized industrial lens in the visible light band in Example 3. DETAILED DESCRIPTION

[0047] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0048] The present invention provides a miniaturized industrial lens with low distortion and high resolution. The industrial lens comprises, in order from the object side to the image side along the optical axis: a first lens L1, a second lens L2, a third lens L3, an aperture C, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, and a ninth lens L9. The first lens L1, the second lens L2, and the third lens L3 constitute a front lens group, and the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, the eighth lens L8, and the ninth lens L9 constitute a rear lens group.

[0049] Among them, the first lens L1 is a negative meniscus lens with its concave surface facing the object side; the second lens L2 is a double concave negative lens; the third lens L3 is a double convex positive lens; the fourth lens L4 is a double convex positive lens; the fifth lens L5 is a negative meniscus lens with its concave surface facing the image side; the sixth lens L6 is a double convex positive lens or a positive meniscus lens with its convex surface facing the object side; the seventh lens L7 is a double concave negative lens or a negative meniscus lens with its concave surface facing the object side; the eighth lens L8 is a double convex positive lens or a positive meniscus lens with its convex surface facing the image side; the ninth lens L9 is a negative meniscus lens with its concave surface facing the image side; the second lens L2 and the third lens L3 are in close contact to form a first cemented group, the fourth lens L4 and the fifth lens L5 are in close contact to form a second cemented group; the sixth lens L6 and the seventh lens L7 are in close contact to form a third cemented group.

[0050] Here, the curved shape of the first lens L1 is conducive to the lens acquiring light at a large angle; the first cemented group consisting of the second lens L2 and the third lens L3 can converge light while balancing the spherical aberration and axial chromatic aberration introduced by the first lens L1. In addition, the design of the first cemented group is conducive to shortening the total optical length and contributing to miniaturization.

[0051] The aperture C is placed between the third lens L3 and the fourth lens L4, and controls the imaging quality and the performance of the optical system by limiting the propagation range and direction of the light beam; the second cemented group composed of the fourth lens L4 and the fifth lens L5 is conducive to the rapid transition of the front light and compensates for chromatic aberration by using a combination of high and low refractive index lenses; the third cemented group composed of the sixth lens L6 and the seventh lens L7 can reduce the optical path of the peripheral light to the image plane, while correcting the off-axis aberration of the system, improving the transmittance of the lens, and reducing the tolerance sensitivity. The eighth lens L8 can focus the light collected by the third cemented group, correct the aberration, and optimize the imaging performance of the lens group. The ninth lens L9 can diverge the light collected by the eighth lens L8, correct the field curvature of the lens, and fine-tune the focal length of the lens to improve the imaging clarity of the lens.

[0052] The lens materials in this optical system are all glass materials with regular refractive index. Example 1

[0053] In the optical system of this example, the sixth lens L6 and the eighth lens L8 are both biconvex positive lenses, and the seventh lens L7 is a biconcave negative lens. Figure 1 shown.

[0054] See Table 1, which lists the relevant parameters of each lens in this example, including the radius of curvature, thickness, refractive index of the material, and Abbe number:

[0055] Table 1

[0056]

[0057] Infinity means infinity.

[0058] In this example, the air distance from the first lens L1 to the second lens L2 is 9.8310 mm; the air distance from the third lens L3 to the aperture C is 3.5444 mm; the air distance from the aperture C to the fourth lens L4 is 1.5069 mm; the air distance from the fifth lens L5 to the sixth lens L6 is 0.1000 mm; the air distance from the seventh lens L7 to the eighth lens L8 is 2.0071 mm; the air distance from the eighth lens L8 to the ninth lens L9 is 0.5200 mm; and the air distance from the ninth lens L9 to the image plane IMG is 12.9548 mm.

[0059] The technical indicators achieved by the optical system in this example are as follows:

[0060] 1) Maximum field of view of industrial lens: FOV = 36.0400°;

[0061] 2) The chief ray angle of the industrial lens: CRA = 12.2384°;

[0062] 3) Focal length of the front lens: f u1 =143.9159 mm;

[0063] 4) Focal length of the rear lens: f u2 =24.8110mm;

[0064] 5) Total focal length of the optical system: f = 16.2359 mm;

[0065] 6) Total optical length of industrial lens: TTL = 53.6403 mm;

[0066] 7) The radius of curvature of the object side of the ninth lens L9: R 91 =-10.9310 mm;

[0067] 8) The radius of curvature of the image side of the ninth lens L9: R 92 =-17.0100 mm;

[0068] 9) Refractive index of the fifth lens L5: N d5 =1.81.

[0069] Then we get: FOV / CRA=2.9448;|f u1 / f|=8.8641;|f u2 / f|=1.5282;TTL / f=3.3038;(R 91 -R 92 ) / (R 91 +R 92 )=-0.2176.

[0070] Here, by closely contacting the second lens L2 and the third lens L3, the fourth lens L4 and the fifth lens L5, and the sixth lens L6 and the seventh lens L7 to form cemented lenses, the chromatic aberration of the optical system can be effectively improved and the sensitivity of the system can be reduced.

[0071] The optical power of the third lens L3 is reasonably controlled to make TTL ≤ 55.23 mm to meet the miniaturization requirements.

[0072] Here, the maximum field of view FOV of the industrial lens and the chief ray angle CRA of the industrial lens are required to meet the following requirements: 2.5≤FOV / CRA≤3.0. The low distortion requirement can be achieved by reasonably allocating the positions of each lens in the optical system.

[0073] Here the total focal length of the optical system is required to be f, and the focal length of the front lens group is f u1 , the focal length of the rear lens is f u1 , satisfying the relationship: 5.5≤|f u1 / f|≤9.0,1.5≤|f u2 / f|≤2.0, by reasonably allocating the proportion of the front and rear group focal lengths and the focal length of the entire lens, the demand for high resolution is achieved, 15.98mm≤f≤16.24 mm.

[0074] In the ninth lens L9, -0.3≤(R 91 -R 92 ) / (R 91 +R 92 )≤-0.1, R 91 The curvature radius of the ninth lens L9 on the object side, R 92 The curvature radius of the image side of the ninth lens L9 is shown in Figure 1. By properly setting the curvature of the ninth lens L9, the aberration of the lens can be reduced and the back focus of the lens can be controlled.

[0075] Here, the refractive index N of the fifth lens L5 is required d5 Satisfy N d5 ≥1.8, by using high refractive index materials, the miniaturization of optical lenses can be achieved.

[0076] In addition, the total optical length of the optical system is TTL, and the total focal length of the optical system is f. By requiring both to satisfy TTL / f≤3.5, miniaturization of the lens is achieved.

[0077] The final imaging effect of the lens in this example is achieved through Figure 2 The MTF graph of the lens shows that the MTF curves in each field of view all drop gently and have good consistency. From the graph, we can see that the MTF value is greater than 0.65 at the spatial frequency of 60pl / mm in the edge field of view, which means that the lens has good imaging effect and resolution in the full field of view. Figure 3 It can be seen from the field curvature distortion diagram that the distortion of this lens does not exceed 0.16%; Figure 4 : This is the axial aberration diagram of the lens of this embodiment. It can be seen that the maximum axial aberration does not exceed 0.06mm, and the imaging quality is good; Figure 5 This is a vertical color difference curve. It can be seen that the vertical axis color difference is less than 3μm.

[0078] Example 2

[0079] In this example, the sixth lens L6 is a double convex positive lens, the seventh lens L7 is a double concave negative lens, and the eighth lens L8 is a meniscus positive lens with the convex surface facing the image side. Figure 6 shown.

[0080] See Table 2, which lists the relevant parameters of each lens in this example, including the radius of curvature, thickness, refractive index of the material, and Abbe number:

[0081] Table 2

[0082]

[0083] In this example, the air distance from the first lens L1 to the second lens L2 is 11.6072 mm; the air distance from the third lens L3 to the aperture C is 4.1871 mm; the air distance from the aperture C to the fourth lens L4 is 1.2919 mm; the air distance from the fifth lens L5 to the sixth lens L6 is 0.1000 mm; the air distance from the seventh lens L7 to the eighth lens L8 is 2.0845 mm; the air distance from the eighth lens L8 to the ninth lens L9 is 0.6661 mm; and the air distance from the ninth lens L9 to the image plane IMG is 11.3633 mm.

[0084] The technical indicators achieved by the optical system in this example are as follows:

[0085] 1) Maximum field of view of industrial lens: FOV = 36.0400°;

[0086] 2) The chief ray angle of the industrial lens: CRA = 12.8883°;

[0087] 3) Focal length of the front lens: f u1 =88.7038 mm;

[0088] 4) Focal length of the rear lens: f u2 =26.1468 mm;

[0089] 5) Total focal length of the optical system: f = 16.1014 mm;

[0090] 6) Total optical length of industrial lens: TTL = 55.2282 mm;

[0091] 7) The radius of curvature of the object side of the ninth lens L9: R 91 =-9.3963 mm;

[0092] 8) The radius of curvature of the image side of the ninth lens L9: R 92 = -12.3122 mm;

[0093] 9) Refractive index of the fifth lens L5: Nd5 =1.81.

[0094] Then we get: FOV / CRA=2.7963;|f u1 / f|=5.5091;|f u2 / f|=1.6239;TTL / f=3.4300;(R 91 -R 92 ) / (R 91 +R 92 )=-0.1343.

[0095] The final imaging effect of the present invention is achieved by Figure 7 The MTF graph of the lens shows that the MTF curves in each field of view decrease smoothly and have good consistency, which means that the lens has good imaging effect and resolution in the full field of view.

[0096] The final imaging effect of the lens in this example is achieved through Figure 7-10 To evaluate, from Figure 7 It can be seen that the MTF value of the edge field at the spatial frequency of 60pl / mm is greater than 0.67; Figure 8 It can be seen from the field curvature distortion diagram that the distortion does not exceed 0.11%; Fig. 9 : This is the axial aberration diagram of the lens of this embodiment. It can be seen that the maximum axial aberration does not exceed 0.07mm, and the imaging quality is good; Fig.10 This is a vertical color difference curve. It can be seen that the vertical axis color difference is less than 2.5μm.

[0097] Example 3

[0098] In this example, the sixth lens L6 of the optical system uses a positive meniscus lens with a convex surface facing the object, the seventh lens L7 uses a negative meniscus lens with a concave surface facing the object, and the eighth lens L8 uses a double convex positive lens. The optical path diagram of this industrial lens is shown in Fig.11 shown.

[0099] See Table 3, which lists the relevant parameters of each lens in this example, including the radius of curvature, thickness, refractive index of the material, and Abbe number:

[0100] Table 3

[0101]

[0102] In this example, the air distance from the first lens L1 to the second lens L2 is 9.6722 mm; the air distance from the third lens L3 to the aperture C is 3.4460 mm; the air distance from the aperture C to the fourth lens L4 is 1.8777 mm; the air distance from the fifth lens L5 to the sixth lens L6 is 0.1000 mm; the air distance from the seventh lens L7 to the eighth lens L8 is 1.9988 mm; the air distance from the eighth lens L8 to the ninth lens L9 is 0.5200 mm; and the air distance from the ninth lens L9 to the image plane IMG is 12.6661 mm.

[0103] The technical indicators achieved by the optical system in this example are as follows:

[0104] 1) Maximum field of view of industrial lens: FOV = 36.0400°;

[0105] 2) The chief ray angle of the industrial lens: CRA = 12.2490°;

[0106] 3) Focal length of the front lens: f u1 =105.9532 mm;

[0107] 4) Focal length of the rear lens: f u2 =25.8906 mm;

[0108] 5) Total focal length of the optical system: f = 15.9863 mm;

[0109] 6) Total optical length of industrial lens: TTL = 55.1838 mm;

[0110] 7) The radius of curvature of the object side of the ninth lens L9: R 91 =-13.4563mm;

[0111] 8) The radius of curvature of the image side of the ninth lens L9: R 92 =-21.5846mm;

[0112] 9) Refractive index of the fifth lens L5: N d5 =1.81.

[0113] Then we get: FOV / CRA=2.9423;|f u1 / f|=6.6278;|f u2 / f|=1.6195; TTL / f=3.4519; (R 91 -R 92 ) / (R 91 +R 92 )=-0.2320.

[0114] The final imaging effect of the lens in this example is achieved through Figure 12-15 To evaluate, from Fig.12 It can be seen that the MTF value of the edge field at the spatial frequency of 60pl / mm is greater than 0.64; Fig.13 It can be seen from the field curvature distortion diagram that the distortion does not exceed 0.1%; Fig.14 The axial aberration diagram of the lens of this embodiment shows that the maximum axial aberration does not exceed 0.05 mm, and the imaging quality is good; Fig.15 This is a vertical color difference curve. It can be seen that the vertical axis color difference is less than 2μm.

[0115] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A miniaturized industrial lens with low distortion and high resolution, characterized in that: The industrial lens is composed of nine lenses in total, which include, in order from the object side to the image side along the optical axis: a first lens L1, a second lens L2, a third lens L3, an aperture C, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, and a ninth lens L9. The first lens L1, the second lens L2, and the third lens L3 constitute a front lens group, and the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, the eighth lens L8, and the ninth lens L9 constitute a rear lens group. The first lens L1 is a negative meniscus lens with a concave surface facing the image side; The second lens L2 is a double concave negative lens; The third lens L3 is a biconvex positive lens; The fourth lens L4 is a biconvex positive lens; The fifth lens L5 is a negative meniscus lens with its concave surface facing the object; The sixth lens L6 is a biconvex positive lens or a meniscus positive lens with the convex surface facing the object; The seventh lens L7 is a biconcave negative lens or a meniscus negative lens with a concave surface facing the image side; The eighth lens L8 is a biconvex positive lens or a meniscus positive lens with the convex surface facing the image side; The ninth lens L9 is a negative meniscus lens with a concave surface facing the object; The second lens L2 and the third lens L3 are closely connected to form a first cemented group, the fourth lens L4 and the fifth lens L5 are closely connected to form a second cemented group; the sixth lens L6 and the seventh lens L7 are closely connected to form a third cemented group; The total focal length of the industrial lens is f, and the focal length of the front lens is f u1 , the focal length of the rear lens is f u1 , satisfying the relationship: 5.5≤|f u1 / f|≤9.0,1.5≤|f u2 / f|≤2.0, the maximum field of view FOV of the industrial lens and the chief ray angle CRA of the industrial lens satisfy the following relationship: 2.5≤FOV / CRA≤3.

0.

2. The low-distortion and high-resolution miniaturized industrial lens according to claim 1, characterized in that: The ninth lens L9 also satisfies the following condition: -0.3≤(R 91 -R 92 ) / (R 91 +R 92 )≤-0.1, where R 91 The curvature radius of the ninth lens L9 on the object side, R 92 It represents the curvature radius of the image surface side of the ninth lens L9.

3. The low-distortion and high-resolution miniaturized industrial lens according to claim 1, characterized in that: Refractive index N of fifth lens L5 d5 Satisfy N d5 ≥1.

8.

4. The low-distortion and high-resolution miniaturized industrial lens according to claim 1, characterized in that: The total optical length of the industrial lens is TTL, and the total focal length of the industrial lens is f, both of which meet the following conditions: TTL / f≤3.

5.

5. The low-distortion and high-resolution miniaturized industrial lens according to claim 1, characterized in that: When the sixth lens L6 and the eighth lens L8 are both double convex positive lenses, and the seventh lens L7 is a double concave negative lens, the air distance from the first lens L1 to the second lens L2 is 9.8310 mm; the air distance from the third lens L3 to the aperture C is 3.5444 mm; the air distance from the aperture C to the fourth lens L4 is 1.5069 mm; the air distance from the fifth lens L5 to the sixth lens L6 is 0.1000 mm; the air distance from the seventh lens L7 to the eighth lens L8 is 2.0071 mm; the air distance from the eighth lens L8 to the ninth lens L9 is 0.5200 mm; and the air distance from the ninth lens L9 to the image plane IMG is 12.9548 mm.

6. The low-distortion and high-resolution miniaturized industrial lens according to claim 1, characterized in that: When the sixth lens L6 adopts a double convex positive lens, the seventh lens L7 adopts a double concave negative lens, and the eighth lens L8 adopts a meniscus positive lens with the convex surface facing the image side, the air distance from the first lens L1 to the second lens L2 is 11.6072mm; the air distance from the third lens L3 to the aperture C is 4.1871mm; the air distance from the aperture C to the fourth lens L4 is 1.2919mm; the air distance from the fifth lens L5 to the sixth lens L6 is 0.1000mm; the air distance from the seventh lens L7 to the eighth lens L8 is 2.0845mm; the air distance from the eighth lens L8 to the ninth lens L9 is 0.6661mm; and the air distance from the ninth lens L9 to the image plane IMG is 11.3632mm.

7. The low-distortion and high-resolution miniaturized industrial lens according to claim 1, characterized in that: When the sixth lens L6 adopts a positive meniscus lens with a convex surface facing the object side, the seventh lens L7 adopts a negative meniscus lens with a concave surface facing the image side, and the eighth lens L8 adopts a double convex positive lens, the air distance from the first lens L1 to the second lens L2 is 9.6722mm; the air distance from the third lens L3 to the aperture C is 3.4460mm; the air distance from the aperture C to the fourth lens L4 is 1.8777mm; the air distance from the fifth lens L5 to the sixth lens L6 is 0.1000mm; the air distance from the seventh lens L7 to the eighth lens L8 is 1.9988mm; the air distance from the eighth lens L8 to the ninth lens L9 is 0.5200mm; and the air distance from the ninth lens L9 to the image plane IMG is 12.6661mm.

Images