Monitoring lens with small volume, low distortion, large target surface and high resolution

Abstract

The invention discloses a monitoring lens with small volume, low distortion, large target surface and high resolution, an optical system of the monitoring lens is composed of 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 diaphragm C, a seventh lens L7, an eighth lens L8, a ninth lens L9, a tenth lens L10 and an image plane IMG which are sequentially arranged along an incident light path, the eighth lens L8 and the ninth lens L9 form a glued lens group; the first lens L1 to the sixth lens L6 form a front group lens; the seventh lens L7 to the tenth lens L10 form a rear group lens. The monitoring lens has the advantages of small size, low distortion, large target surface and high resolution.

Description

Technical Field

[0001] The present invention belongs to the technical field of optical lenses, and particularly relates to a surveillance lens with a small volume, low distortion, large imaging target surface and high resolution. Background Art

[0002] As an important component of the intelligent transportation system, the surveillance lens plays an important role and determines the accuracy of the acquired information.

[0003] Due to the particularity of the application environment, some performances of the surveillance lens need to be different from those of ordinary lenses, such as a smaller volume, lower imaging distortion, a larger imaging target surface and higher resolution.

[0004] There are certain deficiencies in the performances of the existing surveillance lenses on the market. The market needs a surveillance lens with a small volume, low distortion, large target surface and high resolution more.

[0005] Therefore, developing a lens that can fully meet the above requirements has become an urgent task at present. Summary of the Invention

[0006] Aiming at the deficiencies of the existing technology, the present invention provides a surveillance lens with a small volume, low distortion, large target surface and high resolution.

[0007] To achieve the above object, the present invention provides the following technical solution: A surveillance lens with a small volume, low distortion, large target surface and high resolution, the optical system of the surveillance lens is composed of 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 diaphragm C, a seventh lens L7, an eighth lens L8, a ninth lens L9, a tenth lens L10 and an image plane IMG which are sequentially arranged along the incident optical path. The first lens L1 is a biconvex positive lens or a meniscus positive lens with the convex surface facing the object side; The second lens L2 is a biconcave negative lens; The third lens L3 is a biconcave negative lens; The fourth lens L4 is a meniscus positive lens with the convex surface facing the image side; The fifth lens L5 is a biconvex positive lens or a meniscus positive lens with the convex surface facing the image side; The sixth lens L6 is a meniscus positive lens with the convex surface facing the object side; The seventh lens L7 is a biconvex positive lens; The eighth lens L8 is a biconvex positive lens; The ninth lens L9 is a biconcave negative lens; The tenth lens L10 is a biconvex positive lens; Among them, the eighth lens L8 and the ninth lens L9 form a cemented lens group; the first lens L1 to the sixth lens L6 form a front group of lenses; the seventh lens L7 to the tenth lens L10 form a rear group of lenses; The monitoring lens satisfies the following conditional expressions: |f u1 / f| ≤ 3.1, 1.2 ≤ |f u2 / f| ≤ 1.4, 3.6 ≤ TTL / f ≤ 3.7, where f u1 represents the effective focal length of the front lens group; f u2 represents the effective focal length of the rear lens group; f represents the effective focal length of the monitoring lens; TTL represents the overall optical length of the monitoring lens.

[0008] As a specific implementation manner, the monitoring lens further satisfies the following conditional expression: 115 ≤ (FOV × f) / IH ≤ 116.5, where FOV represents the maximum field of view angle of the monitoring lens; IH represents the maximum image plane height of the monitoring lens; f represents the effective focal length of the monitoring lens.

[0009] As a specific implementation manner, the monitoring lens further satisfies the following conditional expression: SD max / TTL ≤ 0.38, where SD max represents the clear aperture of the largest lens in the monitoring lens; TTL represents the overall optical length of the monitoring lens.

[0010] As a specific implementation manner, the monitoring lens further satisfies the following conditional expression: 0.01 ≤ FOV / (D × TTL) ≤ 0.02, where FOV represents the maximum field of view angle of the monitoring lens; D represents the head aperture size of the monitoring lens; TTL represents the overall optical length of the monitoring lens.

[0011] As a specific implementation manner, the monitoring lens further satisfies the following conditional expression: 5.9 ≤ IH / FNO ≤ 6.1, where IH represents the maximum image plane height of the monitoring lens; FNO represents the aperture value of the monitoring lens.

[0012] As a specific implementation manner, the monitoring lens further satisfies the following conditional expression: 13.5 ≤ (f u1 + f u2 ) / IH ≤ 14, where f u1 represents the effective focal length of the front lens group; f u2 represents the effective focal length of the rear lens group; IH represents the maximum image plane height of the monitoring lens.

[0013] As a specific implementation manner, the refractive index of the tenth lens L10 is N d10 and the Abbe number is V D10 , N d10 , V D10 respectively satisfy the following conditions: Nd 10 ≤ 1.9; VD 10 ≥ 42.

[0014] As a specific embodiment, when the first lens L1 is a meniscus positive lens with its convex surface facing the object side; the second lens L2 is a biconcave negative lens; the third lens L3 is a biconcave negative lens; the fourth lens L4 is a meniscus positive lens with its convex surface facing the image side; the fifth lens L5 is a biconvex positive lens; the sixth lens L6 is a meniscus positive lens with its convex surface facing the object side; the seventh lens L7 is a biconvex positive lens; the eighth lens L8 is a biconvex positive lens; the ninth lens L9 is a biconcave negative lens, and the tenth lens L10 is a biconvex positive lens, the air distance from the first lens L1 to the second lens L2 is 3.8674 mm; the air distance from the second lens L2 to the third lens L3 is 5.6613 mm; the air distance from the third lens L3 to the fourth lens L4 is 2.6113 mm; the air distance from the fourth lens L4 to the fifth lens L5 is 0.1566 mm; the air distance from the fifth lens L5 to the sixth lens L6 is 0.1518 mm; the air distance from the sixth lens L6 to the aperture stop C is 8.1180 mm; the air distance from the aperture stop C to the seventh lens L7 is 1.0928 mm; the air distance from the seventh lens L7 to the eighth lens L8 is 0.2300 mm; the air distance from the ninth lens L9 to the tenth lens L10 is 12.6847 mm; the air distance from the tenth lens L10 to the image plane IMG is 13.9076 mm.

[0015] As a specific embodiment, when the first lens L1 is a biconvex positive lens; the second lens L2 is a biconcave negative lens; the third lens L3 is a biconcave negative lens; the fourth lens L4 is a meniscus positive lens with its convex surface facing the image side; the fifth lens L5 is a biconvex positive lens; the sixth lens L6 is a meniscus positive lens with its convex surface facing the object side; the seventh lens L7 is a biconvex positive lens; the eighth lens L8 is a biconvex positive lens; the ninth lens L9 is a biconcave negative lens, and the tenth lens L10 is a biconvex positive lens, the air distance from the first lens L1 to the second lens L2 is 4.0423 mm; the air distance from the second lens L2 to the third lens L3 is 5.4596 mm; the air distance from the third lens L3 to the fourth lens L4 is 2.7359 mm; the air distance from the fourth lens L4 to the fifth lens L5 is 0.1846 mm; the air distance from the fifth lens L5 to the sixth lens L6 is 0.1573 mm; the air distance from the sixth lens L6 to the aperture stop C is 8.1350 mm; the air distance from the aperture stop C to the seventh lens L7 is 0.9864 mm; the air distance from the seventh lens L7 to the eighth lens L8 is 0.1335 mm; the air distance from the ninth lens L9 to the tenth lens L10 is 13.6734 mm; the air distance from the tenth lens L10 to the image plane IMG is 14.5877 mm.

[0016] As a specific embodiment, when the first lens L1 is a biconvex positive lens; the second lens L2 is a biconcave negative lens; the third lens L3 is a biconcave negative lens; the fourth lens L4 is a meniscus positive lens with the convex surface facing the image side; the fifth lens L5 is a meniscus positive lens with the convex surface facing the image side; the sixth lens L6 is a meniscus positive lens with the convex surface facing the object side; the seventh lens L7 is a biconvex positive lens; the eighth lens L8 is a biconvex positive lens; the ninth lens L9 is a biconcave negative lens, and the tenth lens L10 is a biconvex positive lens, the air distance from the first lens L1 to the second lens L2 is 3.4945 mm; the air distance from the second lens L2 to the third lens L3 is 6.4042 mm; the air distance from the third lens L3 to the fourth lens L4 is 2.7213 mm; the air distance from the fourth lens L4 to the fifth lens L5 is 0.1246 mm; the air distance from the fifth lens L5 to the sixth lens L6 is 0.1209 mm; the air distance from the sixth lens L6 to the diaphragm C is 7.9739 mm; the air distance from the diaphragm C to the seventh lens L7 is 0.8099 mm; the air distance from the seventh lens L7 to the eighth lens L8 is 0.1066 mm; the air distance from the ninth lens L9 to the tenth lens L10 is 12.6305 mm; the air distance from the tenth lens L10 to the image plane IMG is 14.0655 mm.

[0017] Compared with the prior art, the present invention provides a surveillance lens with a small volume, low distortion, large target surface, and high resolution, having the following beneficial effects: 1) The present invention realizes the high-resolution requirement of the optical system by reasonably distributing the positions of lenses with different optical powers; 2) By reasonably controlling the ratio of the optical power to the total length of the optical system, that is, requiring 3.6 ≤ TTL / f ≤ 3.7, the requirement of low distortion of the surveillance lens is realized; in addition, by reasonably combining lenses with different optical powers, that is, requiring 115 ≤ (FOV × f) / IH ≤ 116.5, the propagation light rays in the optical system are continuously corrected, and thus the requirement of low distortion is realized; 3) By requiring SD max / TTL ≤ 0.38, 0.01 ≤ FOV / (D × TTL) ≤ 0.02, the miniaturization of the surveillance lens is realized; 4) By requiring 5.9 ≤ IH / FNO ≤ 6.1, 13.5 ≤ (f u1 + f u2 ) / IH ≤ 14, the large target surface of the surveillance lens is realized. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is the optical path diagram of the surveillance lens with a small volume, low distortion, large target surface, and high resolution in Embodiment 1; Figure 2MTF curve of the visible light band of the small-sized, low-distortion, large image plane, and high-resolution monitoring lens in Embodiment 1; Figure 3 Field curvature and distortion diagram of the small-sized, low-distortion, large image plane, and high-resolution monitoring lens in Embodiment 1; Figure 4 Optical path diagram of the small-sized, low-distortion, large image plane, and high-resolution monitoring lens in Embodiment 2; Figure 5 MTF curve of the visible light band of the small-sized, low-distortion, large image plane, and high-resolution monitoring lens in Embodiment 2; Figure 6 Field curvature and distortion diagram of the small-sized, low-distortion, large image plane, and high-resolution monitoring lens in Embodiment 2; Figure 7 Optical path diagram of the small-sized, low-distortion, large image plane, and high-resolution monitoring lens in Embodiment 3; Figure 8 MTF curve of the visible light band of the small-sized, low-distortion, large image plane, and high-resolution monitoring lens in Embodiment 3; Figure 9 Field curvature and distortion diagram of the small-sized, low-distortion, large image plane, and high-resolution monitoring lens in Embodiment 3. Specific implementation manners

[0019] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0020] A surveillance lens with a small volume, low distortion, large target surface, and high resolution. The optical system of the surveillance lens consists of 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 diaphragm C, a seventh lens L7, an eighth lens L8, a ninth lens L9, a tenth lens L10, and an image plane IMG arranged in sequence along the incident light path. The first lens L1 is a biconvex positive lens or a meniscus positive lens with the convex surface facing the object side; the second lens L2 is a biconcave negative lens; the third lens L3 is a biconcave negative lens; the fourth lens L4 is a meniscus positive lens with the convex surface facing the image side; the fifth lens L5 is a biconvex positive lens or a meniscus positive lens with the convex surface facing the image side; the sixth lens L6 is a meniscus positive lens with the convex surface facing the object side; the seventh lens L7 is a biconvex positive lens; the eighth lens L8 is a biconvex positive lens; the ninth lens L9 is a biconcave negative lens; the tenth lens L10 is a biconvex positive lens. Among them, the eighth lens L8 and the ninth lens L9 form a cemented lens group; the first lens L1 to the sixth lens L6 form the front lens group; the seventh lens L7 to the tenth lens L10 form the rear lens group.

[0021] The first lens L1 uses a biconvex positive lens or a meniscus positive lens with the convex surface facing the object side to focus the light entering the lens, which is beneficial for obtaining more light.

[0022] The second lens L2 is used to diverge the light collected by the first lens L1 for aberration correction and optimize the imaging performance of the lens group.

[0023] The third lens L3 is used to perform secondary aberration correction on the light transmitted by the second lens L2.

[0024] The fourth lens L4 is used to collect the light corrected by the third lens L3 and smoothly transmit it to the subsequent optical system.

[0025] The fifth lens L5 is used to compress the light transmitted by the fourth lens L4, which is beneficial for reducing the volume of the lens.

[0026] The sixth lens L6 is used to further compress the light transmitted by the fifth lens L5, which is beneficial for reducing the volume of the lens.

[0027] The diaphragm C is placed between the sixth lens L6 and the seventh lens L7 to control the imaging quality and the performance of the optical system by restricting the propagation range and direction of the light beam.

[0028] The seventh lens L7 is placed behind the diaphragm C to collect the light passing through the diaphragm C.

[0029] The eighth lens L8 and the ninth lens L9 form a cemented lens to correct the light collected by the seventh lens L7 and balance the distortion generated by the lens; at the same time, the eighth lens L8 and the ninth lens L9 use glass lenses to further enhance the stability of the lens group.

[0030] The tenth lens L10 can focus the light corrected by the cemented lens and project it onto the imaging surface.

[0031] In the following embodiments, the lenses all adopt lenses made of glass materials with conventional refractive indices.

[0032] Embodiment 1

[0033] In the optical system of this example, the first lens L1 is a meniscus positive lens with the convex surface facing the object side; the second lens L2 is a double concave negative lens; the third lens L3 is a double concave negative lens; the fourth lens L4 is a meniscus positive lens with the convex surface facing the image side; the fifth lens L5 is a double convex positive lens; the sixth lens L6 is a meniscus positive lens with the convex surface facing the object side; the seventh lens L7 is a double convex positive lens; the eighth lens L8 is a double convex positive lens; the ninth lens L9 is a double concave negative lens, and the tenth lens L10 is a double convex positive lens. The eighth lens L8 and the ninth lens L9 are cemented. The optical path diagram of this surveillance lens is shown in Figure 1 as shown.

[0034] Referring to Table 1, Table 1 lists the relevant parameters of each lens in this example, including the radius of curvature, thickness, refractive index of the material, and Abbe number: Table 1

[0035] Infinity means infinite.

[0036] In this example, the air distance from the first lens L1 to the second lens L2 is 3.8674 mm; the air distance from the second lens L2 to the third lens L3 is 5.6613 mm; the air distance from the third lens L3 to the fourth lens L4 is 2.6113 mm; the air distance from the fourth lens L4 to the fifth lens L5 is 0.1566 mm; the air distance from the fifth lens L5 to the sixth lens L6 is 0.1518 mm; the air distance from the sixth lens L6 to the diaphragm C is 8.1180 mm; the air distance from the diaphragm C to the seventh lens L7 is 1.0928 mm; the air distance from the seventh lens L7 to the eighth lens L8 is 0.2300 mm; the air distance from the ninth lens L9 to the tenth lens L10 is 12.6847 mm; the air distance from the tenth lens L10 to the image surface IMG is 13.9076 mm.

[0037] The technical indicators achieved by the optical system in this example are as follows: 1) The maximum field of view angle of the surveillance lens: FOV = 35.6°; 2) The effective focal length of the front group of lenses: f u1 = 76.8900 mm; 3) The effective focal length of the rear group of lenses: f u2 = 32.7100 mm; 4) Abbe number of the tenth lens L10: V d10 = 42.73; 5) Refractive index of the tenth lens L10: N d10 = 1.83; 6) Effective focal length of the surveillance lens: f = 26.2381 mm; 7) Chief ray angle CRA of the surveillance lens: CRA = 0.4834°; 8) Maximum image height of the surveillance lens: IH = 8.0941 mm; 9) F-number FNO of the surveillance lens: FNO = 1.3409; 10) Head aperture size of the surveillance lens: D = 35.4520 mm; 11) Clear aperture SD of the largest lens in the surveillance lens max : SD max = 35.4520 mm; 12) Optical total length of the surveillance lens: TTL = 96.6083 mm.

[0038] Furthermore, we get: TTL / f = 3.6820; (FOV × f) / IH = 115.4021; |f u1 / f| = 2.9305; |f u2 / f| = 1.2467; SD max / TTL = 0.37; FOV / (D × TTL) = 0.0104; IH / FNO = 6.0363; (f u1 + f u2 ) / IH = 13.5407.

[0039] Here, by reasonably controlling the ratio of the optical power to the total length of the optical system, that is, requiring 3.6 ≤ TTL / f ≤ 3.7, the requirement of low distortion of the surveillance lens is achieved.

[0040] By reasonably combining lenses with different optical powers, that is, requiring 115 ≤ (FOV × f) / IH ≤ 116.5, continuously correcting the propagation light rays in the optical system, and further achieving the requirement of low distortion.

[0041] By requiring SD max / TTL ≤ 0.38, 0.01 ≤ FOV / (D × TTL) ≤ 0.02, and further achieving the miniaturization of the surveillance lens.

[0042] By requiring 5.9 ≤ IH / FNO ≤ 6.1, 13.5 ≤ (f u1 + f u2 ) / IH ≤ 14, and further achieving the large image sensor of the surveillance lens.

[0043] By reasonably selecting the refractive index and Abbe number of the tenth lens L10, i.e., N d10 ≤1.9; V D10 ≥42, glass friendly to thermal drift is used, effectively improving the stability of the lens group.

[0044] In this example, the final imaging effect of the lens is evaluated by Figure 2 the MTF graph. The MTF curves under each field of view all decline smoothly and have good consistency. It can be seen from the graph that at the spatial frequency of 70 pl / mm in the edge field of view, the MTF value is not less than 0.5, indicating that the lens has good imaging effects and resolution within the full field of view angle. Figure 3 This is the field curvature and distortion graph of the lens in this embodiment. It can be seen that the distortion of the lens does not exceed 6%.

[0045] Embodiment 2

[0046] In the optical system of this example, the first lens L1 is a biconvex positive lens; the second lens L2 is a biconcave negative lens; the third lens L3 is a biconcave negative lens; the fourth lens L4 is a meniscus positive lens with the convex surface facing the image side; the fifth lens L5 is a biconvex positive lens; the sixth lens L6 is a meniscus positive lens with the convex surface facing the object side; the seventh lens L7 is a biconvex positive lens; the eighth lens L8 is a biconvex positive lens; the ninth lens L9 is a biconcave negative lens, and the tenth lens L10 is a biconvex positive lens. The optical path diagram of this surveillance lens is shown in Figure 4 the figure shown.

[0047] Referring to Table 2, Table 2 lists the relevant parameters of each lens in this example, including the radius of curvature, thickness, refractive index of the material, and Abbe number: Table 2

[0048] Infinity means infinite.

[0049] In this example, in this example, the air distance from the first lens L1 to the second lens L2 is 4.0423 mm; the air distance from the second lens L2 to the third lens L3 is 5.4596 mm; the air distance from the third lens L3 to the fourth lens L4 is 2.7359 mm; the air distance from the fourth lens L4 to the fifth lens L5 is 0.1846 mm; the air distance from the fifth lens L5 to the sixth lens L6 is 0.1573 mm; the air distance from the sixth lens L6 to the diaphragm C is 8.1350 mm; the air distance from the diaphragm C to the seventh lens L7 is 0.9864 mm; the air distance from the seventh lens L7 to the eighth lens L8 is 0.1335 mm; the air distance from the ninth lens L9 to the tenth lens L10 is 13.6734 mm; the air distance from the tenth lens L10 to the image plane IMG is 14.5877 mm.

[0050] The technical indicators achieved by the optical system in this example are as follows: 1) The maximum field of view angle of the monitoring lens: FOV = 35.6°; 2) The effective focal length of the front lens group: f u1 = 77.1770 mm; 3) The effective focal length of the rear lens group: f u2 = 34.8940 mm; 4) The Abbe number of the tenth lens L10: V d10 = 42.73; 5) The refractive index of the tenth lens L10: N d10 = 1.83; 6) The effective focal length of the monitoring lens: f = 26.4025 mm; 7) The chief ray angle CRA of the monitoring lens: CRA = 0.3159°; 8) The maximum image height of the monitoring lens: IH = 8.0941 mm; 9) The F-number FNO of the monitoring lens: FNO = 1.3501; 10) The head aperture size of the monitoring lens: D = 35.7250 mm; 11) The clear aperture SD of the largest lens in the monitoring lens max : SD max = 35.7250 mm; 12) The total optical length of the monitoring lens: TTL = 96.6103 mm.

[0051] Furthermore, we get: TTL / f = 3.6591; (FOV × f) / IH = 116.1252; |f u1 / f| = 2.9231; |f u2 / f| = 1.3216; SD max / TTL = 0.37; FOV / (D × TTL) = 0.0103; IH / FNO = 5.9952; (f u1 + f u2 ) / IH = 13.8460.

[0052] The final imaging effect of the lens in this example is evaluated by Figures 5 - 6 . It can be seen from Figure 5 that the MTF curves under each field of view decline smoothly and have good consistency. It can be seen from the figure that at the spatial frequency of 70 pl / mm in the marginal field of view, the MTF value is greater than 0.56, indicating that the lens has good imaging effect and resolution within the full field of view angle. It can be seen from Figure 6 the field curvature and distortion diagram that the distortion of the lens does not exceed 5%.

[0053] Example 3

[0054] In the optical system of this example, the first lens L1 is a biconvex positive lens; the second lens L2 is a biconcave negative lens; the third lens L3 is a biconcave negative lens; the fourth lens L4 is a meniscus positive lens with the convex surface facing the image side; the fifth lens L5 is a meniscus positive lens with the convex surface facing the image side; the sixth lens L6 is a meniscus positive lens with the convex surface facing the object side; the seventh lens L7 is a biconvex positive lens; the eighth lens L8 is a biconvex positive lens; the ninth lens L9 is a biconcave negative lens, and the tenth lens L10 is a biconvex positive lens. The optical path diagram of this surveillance lens is shown in Figure 7 as follows.

[0055] Referring to Table 3, Table 3 lists the relevant parameters of each lens in this example, including the radius of curvature, thickness, refractive index of the material, and Abbe number: Table 3

[0056] Infinity means infinite.

[0057] In this example, the air distance from the first lens L1 to the second lens L2 is 3.4945 mm; the air distance from the second lens L2 to the third lens L3 is 6.4042 mm; the air distance from the third lens L3 to the fourth lens L4 is 2.7213 mm; the air distance from the fourth lens L4 to the fifth lens L5 is 0.1246 mm; the air distance from the fifth lens L5 to the sixth lens L6 is 0.1209 mm; the air distance from the sixth lens L6 to the diaphragm C is 7.9739 mm; the air distance from the diaphragm C to the seventh lens L7 is 0.8099 mm; the air distance from the seventh lens L7 to the eighth lens L8 is 0.1066 mm; the air distance from the ninth lens L9 to the tenth lens L10 is 12.6305 mm; the air distance from the tenth lens L10 to the image plane IMG is 14.0655 mm.

[0058] The technical indicators achieved by the optical system in this example are as follows: 1) The maximum field of view angle of the surveillance lens: FOV = 35.6°; 2) The effective focal length of the front group of lenses: f u1 = 78.5530 mm; 3) The effective focal length of the rear group of lenses: f u2 = 32.9130 mm; 4) The Abbe number of the tenth lens L10: V d10 = 42.73; 5) The refractive index of the tenth lens L10: N d10 = 1.83; 6) Effective focal length of the monitoring lens: f = 26.1759 mm; 7) Chief Ray Angle (CRA) of the monitoring lens: CRA = 0.5502°; 8) Maximum image height of the monitoring lens: IH = 8.0941 mm; 9) F-number (FNO) of the monitoring lens: FNO = 1.3412; 10) Head aperture size of the monitoring lens: D = 35.6440 mm; 11) Clear aperture diameter SD of the largest lens in the monitoring lens max : SD max = 35.6440 mm; 12) Overall optical length of the monitoring lens: TTL = 96.7289 mm.

[0059] Furthermore, we get: TTL / f = 3.6953; (FOV × f) / IH = 115.1286; |f u1 / f| = 3.0010; |f u2 / f| = 1.2574; SD max / TTL = 0.37; FOV / (D × TTL) = 0.0103; IH / FNO = 6.0350; (f u1 + f u2 ) / IH = 13.7713.

[0060] The final imaging effect of the lens in this example is evaluated by Figure 8 . It can be seen from Figure 8 that the MTF curves under each field of view decline smoothly and have good consistency. It can be seen from the figure that at the spatial frequency of 70 pl / mm in the marginal field of view, the MTF value is greater than 0.48, indicating that the lens has good imaging effect and resolution within the full field of view angle. It can be seen from Figure 9 the field curvature and distortion diagram that the distortion of the lens does not exceed 6%.

[0061] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A small-volume, low-distortion, large-target-area, high-resolution surveillance lens, characterized in that: The optical system of the monitoring lens is composed of a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, an aperture C, a seventh lens L7, an eighth lens L8, a ninth lens L9, a tenth lens L10 and an image plane IMG, which are arranged in sequence along the incident light path. The first lens L1 is a biconvex positive lens or a meniscus positive lens with the convex surface facing the object; The second lens L2 is a double concave negative lens; The third lens L3 is a double concave negative lens; The fourth lens L4 is a positive meniscus lens with a convex surface facing the image side; The fifth lens L5 is a biconvex positive lens or a meniscus positive lens with the convex surface facing the image side; The sixth lens L6 is a positive meniscus lens with a convex surface facing the object; The seventh lens L7 is a biconvex positive lens; The eighth lens L8 is a biconvex positive lens; The ninth lens L9 is a double concave negative lens; The tenth lens L10 is a biconvex positive lens; The eighth lens L8 and the ninth lens L9 form a cemented lens group; the first lens L1 to the sixth lens L6 form a front lens group; the seventh lens L7 to the tenth lens L10 form a rear lens group; The monitoring lens satisfies the following condition: u1 / f|≤3.1,1.2≤|f u2 / f|≤1.4,3.6≤TTL / f≤3.7,where f u1 Indicates the effective focal length of the front lens group; f u2 It indicates the effective focal length of the rear lens group; f indicates the effective focal length of the surveillance lens; TTL indicates the total optical length of the surveillance lens.

2. The small-volume, low-distortion, large-target-area, high-resolution surveillance lens according to claim 1, characterized in that: The monitoring lens also satisfies the following conditional formula: 115≤(FOV×f) / IH≤116.5, wherein FOV represents the maximum field of view of the monitoring lens; IH represents the maximum image plane height of the monitoring lens; and f represents the effective focal length of the monitoring lens.

3. The small-volume, low-distortion, large-target-area, high-resolution surveillance lens according to claim 1, characterized in that: The monitoring lens also satisfies the following condition: max / TTL≤0.38, where SD max It indicates the aperture of the largest lens in the surveillance lens; TTL indicates the total optical length of the surveillance lens.

4. The small-volume, low-distortion, large-target-area, high-resolution surveillance lens according to claim 1, characterized in that: The monitoring lens also satisfies the following conditional formula: 0.01≤FOV / (D×TTL)≤0.02, wherein FOV represents the maximum field of view of the monitoring lens; D represents the aperture size of the monitoring lens head; and TTL represents the total optical length of the monitoring lens.

5. The small-volume, low-distortion, large-target-area, high-resolution surveillance lens according to claim 1, characterized in that: The monitoring lens also satisfies the following conditional formula: 5.9≤IH / FNO≤6.1, wherein IH represents the maximum image plane height of the monitoring lens; and FNO represents the aperture value of the monitoring lens.

6. The small-volume, low-distortion, large-target-area, high-resolution surveillance lens according to claim 1, characterized in that: The monitoring lens also satisfies the following condition: 13.5≤(f u1 +f u2 ) / IH≤14, where f u1 Indicates the effective focal length of the front lens group; f u2 It indicates the effective focal length of the rear lens group; IH indicates the maximum image height of the surveillance lens.

7. The small-volume, low-distortion, large-target-area, high-resolution surveillance lens according to claim 1, characterized in that: The refractive index of the tenth lens L10 is N d10 , Abbe number is V D10 , N d10 、V D10 The following conditions are met respectively: Nd 10 ≤1.9; VD 10 ≥42.

8. The small-volume, low-distortion, large-target-area, high-resolution surveillance lens according to claim 1, characterized in that: When the first lens L1 is a positive meniscus lens with its convex surface facing the object side; the second lens L2 is a double concave negative lens; the third lens L3 is a double concave negative lens; the fourth lens L4 is a positive meniscus lens with its convex surface facing the image side; the fifth lens L5 is a double convex positive lens; the sixth lens L6 is a positive meniscus lens with its convex surface facing the object side; the seventh lens L7 is a double convex positive lens; the eighth lens L8 is a double convex positive lens; the ninth lens L9 is a double concave negative lens, and the tenth lens L10 is a double convex positive lens, the air distance from the first lens L1 to the second lens L2 is 3.8674mm; the air distance from the second lens L2 to the third lens L3 is 5.6613mm; the third lens L The air distance from the fourth lens L3 to the fourth lens L4 is 2.6113mm; the air distance from the fourth lens L4 to the fifth lens L5 is 0.1566mm; the air distance from the fifth lens L5 to the sixth lens L6 is 0.1518mm; the air distance from the sixth lens L6 to the aperture C is 8.1180mm; the air distance from the aperture C to the seventh lens L7 is 1.0928mm; the air distance from the seventh lens L7 to the eighth lens L8 is 0.2300mm; the air distance from the ninth lens L9 to the tenth lens L10 is 12.6847mm; and the air distance from the tenth lens L10 to the image plane IMG is 13.9076mm.

9. The small-volume, low-distortion, large-target-area, high-resolution surveillance lens according to claim 1, characterized in that: When the first lens L1 is a biconvex positive lens; the second lens L2 is a biconcave negative lens; the third lens L3 is a biconcave negative lens; the fourth lens L4 is a meniscus positive lens with the convex surface facing the image side; the fifth lens L5 is a biconvex positive lens; the sixth lens L6 is a meniscus positive lens with the convex surface facing the object side; the seventh lens L7 is a biconvex positive lens; the eighth lens L8 is a biconvex positive lens; the ninth lens L9 is a biconcave negative lens, and the tenth lens L10 is a biconvex positive lens, the air distance from the first lens L1 to the second lens L2 is 4.0423mm; the air distance from the second lens L2 to the third lens L3 is 5.4596mm; the air distance from the third lens L3 to the fourth The air distance of lens L4 is 2.7359 mm; the air distance from the fourth lens L4 to the fifth lens L5 is 0.1846 mm; the air distance from the fifth lens L5 to the sixth lens L6 is 0.1573 mm; the air distance from the sixth lens L6 to the aperture C is 8.1350 mm; the air distance from the aperture C to the seventh lens L7 is 0.9864 mm; the air distance from the seventh lens L7 to the eighth lens L8 is 0.1335 mm; the air distance from the ninth lens L9 to the tenth lens L10 is 13.6734 mm; and the air distance from the tenth lens L10 to the image plane IMG is 14.5877 mm.

10. The small-volume, low-distortion, large-target-area, high-resolution surveillance lens according to claim 1, characterized in that: When the first lens L1 is a biconvex positive lens; the second lens L2 is a biconcave negative lens; the third lens L3 is a biconcave negative lens; the fourth lens L4 is a meniscus positive lens with the convex surface facing the image side; the fifth lens L5 is a meniscus positive lens with the convex surface facing the image side; the sixth lens L6 is a meniscus positive lens with the convex surface facing the object side; the seventh lens L7 is a biconvex positive lens; the eighth lens L8 is a biconvex positive lens; the ninth lens L9 is a biconcave negative lens, and the tenth lens L10 is a biconvex positive lens, the air distance from the first lens L1 to the second lens L2 is 3.4945mm; the air distance from the second lens L2 to the third lens L3 is 6.4042mm; the third lens L The air distance from the fourth lens L3 to the fourth lens L4 is 2.7213mm; the air distance from the fourth lens L4 to the fifth lens L5 is 0.1246mm; the air distance from the fifth lens L5 to the sixth lens L6 is 0.1209mm; the air distance from the sixth lens L6 to the aperture C is 7.9739mm; the air distance from the aperture C to the seventh lens L7 is 0.8099mm; the air distance from the seventh lens L7 to the eighth lens L8 is 0.1066mm; the air distance from the ninth lens L9 to the tenth lens L10 is 12.6305mm; and the air distance from the tenth lens L10 to the image plane IMG is 14.0655mm.

Images