An industrial optical lens with low distortion and low chromatic aberration

Abstract

The present invention discloses an industrial optical lens with low distortion and low chromatic aberration, which 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, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, a stop C, a ninth lens L9, a tenth lens L10, an eleventh lens L11 and a twelfth lens L12, wherein the first lens L1 to the seventh lens L7 constitute a front lens group; the eighth lens L8 to the twelfth lens L12 constitute a rear lens group; the fifth lens L5 and the sixth lens L6 are closely connected to form a first cemented group; the tenth lens L10 and the eleventh lens L11 are closely connected to form a second cemented group. The industrial optical lens of the present invention has the performance of low distortion, wide imaging range and high image clarity.

Description

Technical Field

[0001] The invention belongs to the technical field of optical lenses, and in particular relates to an industrial optical lens with low distortion and low chromatic aberration. Background Art

[0002] In industrial automation systems, the precise acquisition of image data depends on the optical lens at the front end, which directly determines the accuracy of information acquisition.

[0003] In view of the special needs of industrial applications, optical lenses need to exhibit performance characteristics that are superior to ordinary lenses, specifically a wider imaging range, lower distortion, higher image clarity, and a more compact size.

[0004] However, the optical lenses currently on the market still have defects in fully meeting the requirements of large field of view, low distortion and high clarity, and the market demand for small industrial optical lenses with these characteristics is continuing to grow.

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

[0006] In view of the deficiencies in the prior art, the present invention provides an industrial optical lens with low distortion and low chromatic aberration, which has the performance of miniaturization, large target surface, low distortion and high resolution.

[0007] To achieve the above object, the present invention provides the following technical solution: an industrial optical lens with low distortion and low chromatic aberration, comprising, 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, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, an aperture C, a ninth lens L9, a tenth lens L10, an eleventh lens L11 and a twelfth lens L12,

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

[0009] The second lens L2 is a negative meniscus lens with a concave surface facing the object;

[0010] The third lens L3 is a negative meniscus lens with its concave surface facing the object;

[0011] The fourth lens L4 is a double concave negative lens;

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

[0013] The sixth lens L6 is a negative meniscus lens with a concave surface facing the image side;

[0014] The seventh lens L7 is a meniscus positive lens or a biconvex positive lens with a convex surface facing the object;

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

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

[0017] The tenth lens L10 is a biconvex positive lens;

[0018] The eleventh lens L11 is a negative meniscus lens with a concave surface facing the image side;

[0019] The twelfth lens L12 is a biconvex positive lens;

[0020] Among them, the first lens L1 to the seventh lens L7 constitute the front lens group; the eighth lens L8 to the twelfth lens L12 constitute the rear lens group; the fifth lens L5 and the sixth lens L6 are closely connected to form a first cemented group; the tenth lens L10 and the eleventh lens L11 are closely connected to form a second cemented group; the effective focal length of the first cemented group is f G1 , the effective focal length of the second cemented group is f G2 , the effective focal length of the optical lens is f, and the maximum field of view of the optical lens is FOV, f G1 、f G2 , f and FOV meet the following conditions: -3.5≤(f G1 ×f / f G2 )×tan(FOV / 4)≤-1.6.

[0021] As a specific implementation, the maximum field of view angle of the optical lens is FOV, the chief ray angle of the optical system is CRA, and FOV and CRA satisfy the following condition: 6≤FOV / CRA≤7.

[0022] As a specific implementation, the maximum image plane height of the optical lens is IH, the effective focal length of the optical lens is f, the maximum field of view of the optical lens is FOV, and IH, f and FOV satisfy the following condition: (FOV×f) / IH≥84.

[0023] As a specific implementation, the effective focal length of the front lens group is f u1 , the effective focal length of the rear lens is f u2 , f u1 With f u2 The following conditions are met: 4.9≤|f u1 / f u2 |≤11.

[0024] As a specific implementation, the total optical length of the optical lens is TTL, the effective focal length of the optical lens is f, and TTL and f satisfy the following condition: TTL / f≤13.1.

[0025] As a specific implementation, the twelfth lens L12 satisfies the following condition: -1.5≤(R 121 -R 122 ) / (R 121 +R 122 )≤-1.3, where R 121 R is the radius of curvature of the object side of the twelfth lens L12; 122 is the curvature radius of the image-side surface of the twelfth lens L12.

[0026] As a specific implementation manner, the refractive index N of the fifth lens L5 is d5 Meet the following conditions: N d5 ≥1.9.

[0027] As a specific implementation, when the seventh lens L7 and the eighth lens L8 are both meniscus positive lenses with convex surfaces facing the object side, the air distance from the first lens L1 to the second lens L2 is 0.1300 mm; the air distance from the second lens L2 to the third lens L3 is 4.5396 mm; the air distance from the third lens L3 to the fourth lens L4 is 3.9057 mm; the air distance from the fourth lens L4 to the fifth lens L5 is 2.2390 mm; the air distance from the sixth lens L6 to the seventh lens L7 is 0 .1300mm; the air distance from the seventh lens L7 to the eighth lens L8 is 9.2237mm; the air distance from the eighth lens L8 to the aperture C is 1.8847mm; the air distance from the aperture C to the ninth lens L9 is 2.0000mm; the air distance from the ninth lens L9 to the tenth lens L10 is 0.6500mm, the air distance from the eleventh lens L11 to the twelfth lens L12 is 0.4500mm; the air distance from the twelfth lens L12 to the image plane IMG is 9.4808mm.

[0028] As a specific implementation, when the seventh lens L7 is a biconvex positive lens and the eighth lens L8 is a meniscus positive lens with the convex surface facing the object, the air distance from the first lens L1 to the second lens L2 is 0.1300 mm; the air distance from the second lens L2 to the third lens L3 is 4.9847 mm; the air distance from the third lens L3 to the fourth lens L4 is 3.6964 mm; the air distance from the fourth lens L4 to the fifth lens L5 is 2.1882 mm; the air distance from the sixth lens L6 to the seventh lens L7 ... The air distance from the seventh lens L7 to the eighth lens L8 is 9.9206mm; the air distance from the eighth lens L8 to the aperture C is 1.2622mm; the air distance from the aperture C to the ninth lens L9 is 2.0000mm; the air distance from the ninth lens L9 to the tenth lens L10 is 0.6500mm, the air distance from the eleventh lens L11 to the twelfth lens L12 is 0.4500mm; the air distance from the twelfth lens L12 to the image plane IMG is 9.5041mm.

[0029] As a specific implementation, when the seventh lens L7 adopts a meniscus positive lens with a convex surface facing the object 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 0.1300 mm; the air distance from the second lens L2 to the third lens L3 is 5.5342 mm; the air distance from the third lens L3 to the fourth lens L4 is 3.0832 mm; the air distance from the fourth lens L4 to the fifth lens L5 is 1.9550 mm; the air distance from the sixth lens L6 to the seventh lens L7 is 1.9660 mm; the air distance from the sixth lens L6 to the seventh lens L7 is 2.3060 mm; the air distance from the sixth lens L6 to the seventh lens L7 is 3.0832 mm; the air distance from the sixth lens L6 to the seventh lens L7 is 2.3060 ... The air distance from the seventh lens L7 to the eighth lens L8 is 9.9731mm; the air distance from the eighth lens L8 to the aperture C is 1.2308mm; the air distance from the aperture C to the ninth lens L9 is 2.0000mm; the air distance from the ninth lens L9 to the tenth lens L10 is 0.6500mm, the air distance from the eleventh lens L11 to the twelfth lens L12 is 0.4500mm; the air distance from the twelfth lens L12 to the image plane IMG is 9.4865mm.

[0030] Compared with the prior art, the present invention provides an industrial optical lens with low distortion and low chromatic aberration, which has the following beneficial effects:

[0031] 1) The present invention can effectively improve the chromatic aberration of the optical system and reduce the sensitivity of the system by gluing the fifth lens L5 and the sixth lens L6, and the tenth lens L10 and the eleventh lens L11 together to form a glued lens;

[0032] 2) The present invention reasonably controls the focal length of the seventh lens L7 so that TTL is ≤ 67.59 mm to meet the miniaturization requirements;

[0033] 3) The present invention reduces the aberration of the lens and controls the back focus of the lens by reasonably setting the curvature of the twelfth lens L12;

[0034] 4) Control the incident light to focus on a wider image plane through the aperture, thereby achieving the large target surface requirement of the lens;

[0035] 5) The refractive index of the fifth lens L5 is limited, and a high refractive index material is used to achieve miniaturization of the optical lens. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is a light path diagram of the industrial optical lens with low distortion and low chromatic aberration in Example 1;

[0037] Figure 2 The MTF curve of the low-distortion and low-chromatic-aberration industrial optical lens in the visible light band in Example 1;

[0038] Figure 3 The field curvature and distortion diagram of the low-distortion and low-chromatic-aberration industrial optical lens in Example 1;

[0039] Figure 4 is a relative illumination curve diagram of the industrial optical lens with low distortion and low chromatic aberration in Example 1;

[0040] Figure 5 The axial aberration curve of the low-distortion and low-chromatic-aberration industrial optical lens in the visible light band in Example 1;

[0041] Figure 6 The vertical axis chromatic aberration curve of the low-distortion and low-chromatic aberration industrial optical lens in the visible light band in Example 1;

[0042] Figure 7 This is a light path diagram of the low-distortion and low-chromatic-aberration industrial optical lens in Example 2;

[0043] Figure 8 The MTF curve of the low-distortion and low-chromatic-aberration industrial optical lens in the visible light band in Example 2;

[0044] Fig. 9 The field curvature and distortion diagram of the low-distortion and low-chromatic-aberration industrial optical lens in Example 2;

[0045] Fig.10 is a relative illumination curve diagram of the industrial optical lens with low distortion and low chromatic aberration in Example 2;

[0046] Fig.11 The axial aberration curve of the low-distortion and low-chromatic-aberration industrial optical lens in the visible light band in Example 2;

[0047] Fig.12The vertical axis chromatic aberration curve of the low-distortion and low-chromatic aberration industrial optical lens in the visible light band in Example 2;

[0048] Fig.13 This is a light path diagram of the low-distortion and low-chromatic-aberration industrial optical lens in Example 3;

[0049] Fig.14 The MTF curve of the low-distortion and low-chromatic-aberration industrial optical lens in the visible light band in Example 3;

[0050] Fig.15 The field curvature and distortion diagram of the low-distortion and low-chromatic-aberration industrial optical lens in Example 3;

[0051] Fig.16 is a relative illumination curve diagram of the industrial optical lens with low distortion and low chromatic aberration in Example 3;

[0052] Fig.17 The axial aberration curve of the low-distortion and low-chromatic-aberration industrial optical lens in the visible light band in Example 3;

[0053] Fig.18 This is a vertical axis chromatic aberration curve of the low-distortion and low-chromatic aberration industrial optical lens in the visible light band in Example 3. DETAILED DESCRIPTION

[0054] 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.

[0055] The present invention provides an industrial optical lens with low distortion and low chromatic aberration, which 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, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, an aperture C, a ninth lens L9, a tenth lens L10, an eleventh lens L11 and a twelfth lens L12.

[0056] Among them, the first lens L1 is a positive meniscus lens with a convex surface facing the object; the second lens L2 is a negative meniscus lens with a concave surface facing the object; the third lens L3 is a negative meniscus lens with a concave surface facing the object; the fourth lens L4 is a double concave negative lens; the fifth lens L5 is a positive meniscus lens with a convex surface facing the image; the sixth lens L6 is a negative meniscus lens with a concave surface facing the image; the seventh lens L7 is a positive meniscus lens or a double convex positive lens with a convex surface facing the object; the eighth lens L8 is a positive meniscus lens or a double convex positive lens with a convex surface facing the object; the ninth lens L9 is a negative meniscus lens with a concave surface facing the object; the tenth lens L10 is a double convex positive lens; the eleventh lens L11 is a negative meniscus lens with a concave surface facing the image; and the twelfth lens L12 is a double convex positive lens.

[0057] Here, the first lens L1 to the seventh lens L7 constitute a front lens group; the eighth lens L8 to the twelfth lens L12 constitute a rear lens group; the fifth lens L5 and the sixth lens L6 are closely connected to form a first cemented group; the tenth lens L10 and the eleventh lens L11 are closely connected to form a second cemented group. Example 1

[0058] In the optical system of this example, the seventh lens L7 and the eighth lens L8 are both meniscus positive lenses with the convex surface facing the object. Figure 1 shown.

[0059] 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:

[0060] Table 1

[0061]

[0062] Infinity means infinity.

[0063] In this example, the air distance from the first lens L1 to the second lens L2 is 0.1300 mm; the air distance from the second lens L2 to the third lens L3 is 4.5396 mm; the air distance from the third lens L3 to the fourth lens L4 is 3.9057 mm; the air distance from the fourth lens L4 to the fifth lens L5 is 2.2390 mm; the air distance from the sixth lens L6 to the seventh lens L7 is 0.1300 mm; the air distance from the seventh lens L7 to the eighth lens L8 is 9.2237 mm; the air distance from the eighth lens L8 to the aperture C is 1.8847 mm; the air distance from the aperture C to the ninth lens L9 is 2.0000 mm; the air distance from the ninth lens L9 to the tenth lens L10 is 0.6500 mm, the air distance from the eleventh lens L11 to the twelfth lens L12 is 0.4500 mm; and the air distance from the twelfth lens L12 to the image plane IMG is 9.4808 mm.

[0064] The technical indicators achieved by the optical system in this example are as follows:

[0065] 1) Maximum field of view of the optical lens: FOV = 91.07°;

[0066] 2) Chief ray angle of the optical system: CRA = 13.4290;

[0067] 3) Effective focal length of the front lens: f u1 =-80.8392mm;

[0068] 4) Effective focal length of the rear lens: f u2 =15.5567mm;

[0069] 5) Effective focal length of optical lens: f=5.2157mm;

[0070] 6) Total optical length of the optical lens: TTL = 66.7819 mm;

[0071] 7) The radius of curvature of the object side of the twelfth lens L12: R 121 =46.0600 mm;

[0072] 8) The radius of curvature of the image side of the twelfth lens L12: R 122 =-8.9390 mm;

[0073] 9) Refractive index of the fifth lens L5: N d5 =1.90;

[0074] 10) Effective focal length of the first cemented group: f G1 =44.0901mm;

[0075] 11) Effective focal length of the second cemented group: f G2 =-139.6051mm;

[0076] 12) Maximum image height of optical lens: IH=5.5mm.

[0077] Then we get: (f G1 ×f / f G2 )×tan(FOV / 4)=-1.6177; FOV / CRA=6.7816; (FOV×f) / IH=86.3618; |f u1 / f u2 |=5.1964; TTL / f=12.8041; (R 121 -R 122 ) / (R 121 +R 122 )=1.4816.

[0078] Here, the requirements of low distortion and low chromatic aberration are achieved by reasonably allocating the optical power of the glued lenses; the requirement of low distortion is achieved by reasonably allocating the positions of the lenses in the optical system; the resolution of a large field of view is achieved by reasonably setting the maximum field angle and focal length of the lens; the requirement of clear imaging on a large target surface is achieved by reasonably allocating the optical power of the front group and the rear group; the aberration of the lens is reduced and the back focus of the lens is controlled by reasonably setting the curvature of the twelfth lens L12; the fifth lens L5 adopts a high refractive index material to achieve miniaturization of the optical lens.

[0079] 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. As can be seen from the graph, the MTF value of the edge field of view at a spatial frequency of 60pl / mm is greater than 0.62, which means that the lens has good imaging effect and resolution in the entire field of view. Figure 3 It can be seen from the field curvature distortion diagram that the distortion of this lens does not exceed 3.5%; Figure 4 It can be seen from the relative illumination curve of the lens of this embodiment that, under the condition of maximum field of view, the relative illumination value of the lens is greater than 65%; Figure 5 : 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; Figure 6 This is the vertical axis chromatic aberration curve. It can be seen that the vertical axis chromatic aberration is less than 4μm. Example 2

[0080] In this example, in the optical system, the seventh lens L7 is a double convex positive lens, and the eighth lens L8 is a meniscus positive lens with the convex surface facing the object. The optical path diagram of the optical lens is shown in FIG. Figure 7 shown.

[0081] 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:

[0082] Table 2

[0083]

[0084] In this example, the air distance from the first lens L1 to the second lens L2 is 0.1300 mm; the air distance from the second lens L2 to the third lens L3 is 4.9847 mm; the air distance from the third lens L3 to the fourth lens L4 is 3.6964 mm; the air distance from the fourth lens L4 to the fifth lens L5 is 2.1882 mm; the air distance from the sixth lens L6 to the seventh lens L7 is 0.1300 mm; the air distance from the seventh lens L7 to the eighth lens L8 is 9.9206 mm; the air distance from the eighth lens L8 to the aperture C is 1.2622 mm; the air distance from the aperture C to the ninth lens L9 is 2.0000 mm; the air distance from the ninth lens L9 to the tenth lens L10 is 0.6500 mm, the air distance from the eleventh lens L11 to the twelfth lens L12 is 0.4500 mm; and the air distance from the twelfth lens L12 to the image plane IMG is 9.5041 mm.

[0085] The technical indicators achieved by the optical system in this example are as follows:

[0086] 1) Maximum field of view of the optical lens: FOV = 91.07°;

[0087] 2) Chief ray angle of the optical system: CRA = 14.0020;

[0088] 3) Effective focal length of the front lens: f u1 = -170.3248 mm;

[0089] 4) Effective focal length of the rear lens: f u2 =15.5209 mm;

[0090] 5) Effective focal length of optical lens: f=5.1290mm;

[0091] 6) Total optical length of the optical lens: TTL = 66.7926 mm;

[0092] 7) The radius of curvature of the object side of the twelfth lens L12: R 121 =45.4856 mm;

[0093] 8) The radius of curvature of the image side of the twelfth lens L12: R 122 =-8.9328 mm;

[0094] 9) Refractive index of the fifth lens L5: N d5 =1.90;

[0095] 10) Effective focal length of the first cemented group: f G1 =83.0098mm;

[0096] 11) Effective focal length of the second cemented group: fG2 = -119.9763 mm;

[0097] 12) Maximum image height of optical lens: IH=5.5mm.

[0098] Then we get: (f G1 ×f / f G2 )×tan(FOV / 4)=-3.4851; FOV / CRA=6.5041; (FOV×f) / IH=84.9272; |f u1 / f u2 |=10.9739; TTL / f=13.0225; (R 121 -R 122 ) / (R 121 +R 122 )=1.4888.

[0099] The final imaging effect of the lens in this example is achieved through Figure 8-12 To evaluate, from Fig.12 It can be seen that the MTF curves under each field of view are all declining smoothly and have good consistency. It can be seen from the figure that the MTF value is greater than 0.72 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. Fig. 9 It can be seen from the field curvature distortion diagram that the distortion of this lens does not exceed 2%; Fig.10 It can be seen from the relative illumination curve of the lens of this embodiment that, under the condition of maximum field of view, the relative illumination value of the lens is greater than 70%; Fig.11 : 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; Fig.12 This is the vertical axis chromatic aberration curve. It can be seen that the vertical axis chromatic aberration is less than 4.5μm. Example 3

[0100] In this example, in the optical system, the seventh lens L7 is a positive meniscus lens with the convex surface facing the object, and the eighth lens L8 is a double convex positive lens. The optical path diagram of the optical lens is shown in FIG. Fig.13 shown.

[0101] 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:

[0102] Table 3

[0103]

[0104] In this example, the air distance from the first lens L1 to the second lens L2 is 0.1300 mm; the air distance from the second lens L2 to the third lens L3 is 5.5342 mm; the air distance from the third lens L3 to the fourth lens L4 is 3.0832 mm; the air distance from the fourth lens L4 to the fifth lens L5 is 1.9550 mm; the air distance from the sixth lens L6 to the seventh lens L7 is 0.1300 mm; the air distance from the seventh lens L7 to the eighth lens L8 is 9.9731 mm; the air distance from the eighth lens L8 to the aperture C is 1.2308 mm; the air distance from the aperture C to the ninth lens L9 is 2.0000 mm; the air distance from the ninth lens L9 to the tenth lens L10 is 0.6500 mm, the air distance from the eleventh lens L11 to the twelfth lens L12 is 0.4500 mm; and the air distance from the twelfth lens L12 to the image plane IMG is 9.4865 mm.

[0105] The technical indicators achieved by the optical system in this example are as follows:

[0106] 1) Maximum field of view of the optical lens: FOV = 91.07°;

[0107] 2) Chief ray angle of the optical system: CRA = 14.1010;

[0108] 3) Effective focal length of the front lens: f u1 =-74.1685mm;

[0109] 4) Effective focal length of the rear lens: f u2 =15.0680mm;

[0110] 5) Effective focal length of optical lens: f=5.1438mm;

[0111] 6) Total optical length of the optical lens: TTL = 66.7714 mm;

[0112] 7) The radius of curvature of the object side of the twelfth lens L12: R 121 =56.2447mm;

[0113] 8) The radius of curvature of the image side of the twelfth lens L12: R 122 =-8.7033mm;

[0114] 9) Refractive index of the fifth lens L5: N d5 =1.90;

[0115] 10) Effective focal length of the first cemented group: f G1 =40.6970mm;

[0116] 11) Effective focal length of the second cemented group: fG2 =-104.0148mm;

[0117] 12) Maximum image height of optical lens: IH=5.5mm.

[0118] Then we get: (f G1 ×f / f G2 )×tan(FOV / 4)=-1.9765; FOV / CRA=6.4584; (FOV×f) / IH=85.1723; |f u1 / f u2 |=4.9222; TTL / f=12.9809; (R 121 -R 122 ) / (R 121 +R 122 )=1.3661.

[0119] The final imaging effect of the lens in this example is achieved through Fig.14 To evaluate, from Fig.14 It can be seen that the MTF curves under each field of view are all declining smoothly and have good consistency. It can be seen from the figure that the MTF value is greater than 0.67 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. Fig.15 It can be seen from the field curvature distortion diagram that the distortion of this lens does not exceed 2.5%; Fig.16 It can be seen from the relative illumination curve of the lens of this embodiment that, under the condition of maximum field of view, the relative illumination value of the lens is greater than 65%; Fig.17 : 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; Fig.18 This is the vertical axis chromatic aberration curve. It can be seen that the vertical axis chromatic aberration is less than 5μm.

[0120] 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. An industrial optical lens with low distortion and low chromatic aberration, characterized in that: The optical lens has twelve 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, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, an aperture C, a ninth lens L9, a tenth lens L10, an eleventh lens L11 and a twelfth lens L12, The first lens L1 is a positive meniscus lens with its convex surface facing the object; The second lens L2 is a negative meniscus lens with a concave surface facing the image side; The third lens L3 is a negative meniscus lens with a concave surface facing the image side; The fourth lens L4 is a double concave negative lens; The fifth lens L5 is a positive meniscus lens with a convex surface facing the image side; The sixth lens L6 is a negative meniscus lens with a concave surface facing the object; The seventh lens L7 is a meniscus positive lens or a biconvex positive lens with a convex surface facing the object; The eighth lens L8 is a meniscus positive lens or a biconvex positive lens with its convex surface facing the object; The ninth lens L9 is a negative meniscus lens with a concave surface facing the image side; The tenth lens L10 is a biconvex positive lens; The eleventh lens L11 is a negative meniscus lens with a concave surface facing the object side; The twelfth lens L12 is a biconvex positive lens; Among them, the first lens L1 to the seventh lens L7 constitute a front lens group; the eighth lens L8 to the twelfth lens L12 constitute a rear lens group; the fifth lens L5 and the sixth lens L6 are closely connected to form a first cemented group; the tenth lens L10 and the eleventh lens L11 are closely connected to form a second cemented group; The maximum field of view of the optical lens is FOV, and the chief ray angle of the optical lens is CRA. FOV and CRA meet the following conditions: 6≤FOV / CRA≤7; The effective focal length of the front lens is f u1 , the effective focal length of the rear lens is f u2 , f u1 With f u2 The following conditions are met: 4.9≤|f u1 / f u2 |≤11; The total optical length of the optical lens is TTL, the effective focal length of the optical lens is f, and TTL and f satisfy the following condition: 12.8041≤TTL / f≤13.

1.

2. The low-distortion and low-chromatic-aberration industrial optical lens according to claim 1, characterized in that: The maximum image plane height of the optical lens is IH, the effective focal length of the optical lens is f, the maximum field of view of the optical lens is FOV, and IH, f and FOV satisfy the following conditions: 84≤(FOV×f) / IH≤86.3618.

3. The low-distortion and low-chromatic-aberration industrial optical lens according to claim 1, characterized in that: The twelfth lens L12 satisfies the following condition: 1.3≤(R 121 -R 122 ) / (R 121 +R 122 )≤1.5, where R 121 R is the radius of curvature of the object side of the twelfth lens L12; 122 is the curvature radius of the image-side surface of the twelfth lens L12.

4. The low-distortion and low-chromatic-aberration industrial optical lens according to claim 1, characterized in that: Refractive index N of fifth lens L5 d5 Meet the following conditions: N d5 ≥1.

9.

5. The low-distortion and low-chromatic-aberration industrial optical lens according to claim 1, characterized in that: When the seventh lens L7 and the eighth lens L8 are both meniscus positive lenses with the convex surface facing the object, the air distance from the first lens L1 to the second lens L2 is 0.1300 mm; the air distance from the second lens L2 to the third lens L3 is 4.5396 mm; The air distance from the third lens L3 to the fourth lens L4 is 3.9057 mm; the air distance from the fourth lens L4 to the fifth lens L5 is 2.2390 mm; the air distance from the sixth lens L6 to the seventh lens L7 is 0.1300 mm; the air distance from the seventh lens L7 to the eighth lens L8 is 9.2237 mm; the air distance from the eighth lens L8 to the aperture C is 1.8847 mm; the air distance from the aperture C to the ninth lens L9 is 2.0000 mm; the air distance from the ninth lens L9 to the tenth lens L10 is 0.6500 mm, the air distance from the eleventh lens L11 to the twelfth lens L12 is 0.4500 mm; and the air distance from the twelfth lens L12 to the image plane IMG is 9.4808 mm.

6. The low-distortion and low-chromatic-aberration industrial optical lens according to claim 1, characterized in that: When the seventh lens L7 adopts a double convex positive lens, and the eighth lens L8 adopts a meniscus positive lens with the convex surface facing the object side, the air distance from the first lens L1 to the second lens L2 is 0.1300 mm; the air distance from the second lens L2 to the third lens L3 is 4.9847 mm; the air distance from the third lens L3 to the fourth lens L4 is 3.6964 mm; the air distance from the fourth lens L4 to the fifth lens L5 is 2.1882 mm; the air distance from the sixth lens L6 to the seventh lens L7 is 0.1300 mm; the air distance from the seventh lens L7 to the eighth lens L8 is 9.9206 mm; the air distance from the eighth lens L8 to the aperture C is 1.2622 mm; and the air distance from the aperture C to the ninth lens L9 is 2.0000 mm; The air distance between the ninth lens L9 and the tenth lens L10 is 0.6500 mm, the air distance between the eleventh lens L11 and the twelfth lens L12 is 0.4500 mm, and the air distance between the twelfth lens L12 and the image plane IMG is 9.5041 mm.

7. The low-distortion and low-chromatic-aberration industrial optical lens according to claim 1, characterized in that: When the seventh lens L7 adopts a meniscus positive lens with the convex 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 0.1300mm; the air distance from the second lens L2 to the third lens L3 is 5.5342mm; the air distance from the third lens L3 to the fourth lens L4 is 3.0832mm; the air distance from the fourth lens L4 to the fifth lens L5 is 1.9550mm; the air distance from the sixth lens L6 to the seventh lens L7 is 0.1 300mm; the air distance from the seventh lens L7 to the eighth lens L8 is 9.9731mm; the air distance from the eighth lens L8 to the aperture C is 1.2308mm; the air distance from the aperture C to the ninth lens L9 is 2.0000mm; the air distance from the ninth lens L9 to the tenth lens L10 is 0.6500mm, the air distance from the eleventh lens L11 to the twelfth lens L12 is 0.4500mm; the air distance from the twelfth lens L12 to the image plane IMG is 9.4865mm.

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