Day and night confocal lens and shooting device

Abstract

The utility model discloses a day and night confocal lens and a shooting device, and relates to the technical field of optics, and the day and night confocal lens is provided with an object side and an image side which are correspondingly arranged along the direction of an optical axis. The day and night confocal lens comprises a first lens, a second lens, a diaphragm, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, an optical filter, protective glass and a photosensitive chip which are sequentially arranged from an object side to an image side, and the surface, facing the object side, of the photosensitive chip is an image surface. The day and night confocal lens comprises a first lens and a second lens, so that the field angle of the day and night confocal lens can reach 144 degrees or more, the image plane height of the day and night confocal lens can reach 10 mm, CRA is lower than 10 degrees, the diameter of the first lens is D1, the aperture value of the day and night confocal lens is F, and the day and night confocal lens meets the following conditions that D1 is smaller than 15 mm; f < = 1.6. Through the arrangement, the lens which is large in aperture, large in visual angle and small in infrared defocusing amount and has a day and night confocal function can be provided.

Description

Technical Field

[0001] The utility model relates to the technical field of optical systems, and particularly relates to a day-night confocal lens and a photographing device. Background Art

[0002] The demand for surveillance fixed-focus lenses is increasing. Among them, large-aperture lenses have a higher light transmittance and better meet the market demand in terms of performance. Moreover, chips with large pixels and large target surfaces have more excellent photosensitive performance. Therefore, it is very necessary to research and design a lens with a large aperture and a large target surface.

[0003] However, large apertures and large target surfaces often bring more difficult-to-correct chromatic aberration and off-axis aberration to the optical system, resulting in poor peripheral field performance and excessive infrared defocus. This means that the application scenario of the lens cannot use infrared light to increase the system light transmittance, affecting the performance of the lens at night. Summary of the Utility Model

[0004] The main purpose of the utility model is to propose a day-night confocal lens and a photographing device, aiming to solve the problem that the existing lenses cannot have both a large aperture, a large target surface, good chromatic aberration and off-axis aberration, resulting in poor peripheral field performance and excessive infrared defocus, and the application scenario cannot use infrared light to increase the system light transmittance, affecting the performance of the lens at night.

[0005] To achieve the above object, the day-night confocal lens proposed by the utility model has an object side and an image side arranged corresponding to each other along the optical axis direction. The day-night confocal lens includes a first lens, a second lens, a diaphragm, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, a filter, a protective glass, and a photosensitive chip arranged in sequence from the object side to the image side. The surface of the photosensitive chip facing the object side is the image plane, so that the field of view angle of the day-night confocal lens can reach more than 144°, the image plane height of the day-night confocal lens can reach 10 mm, and the CRA is less than 10°. The diameter of the first lens is D1, and the aperture value of the day-night confocal lens is F. The day-night confocal lens satisfies the following conditions:

[0006] D1 < 15 mm; F ≤ 1.6.

[0007] In an embodiment, the first lens is a negative lens, the object side surface of the first lens is convex, and the image side surface is concave;

[0008] The second lens is a negative lens, the object side surface of the second lens is concave, and the image side surface is convex;

[0009] The third lens is a positive lens, the object side surface of the third lens is convex, and the image side surface is concave;

[0010] The fourth lens is a positive lens, the object side of the fourth lens is convex, and the image side is convex;

[0011] The fifth lens is a positive lens, the object side of the fifth lens is convex, and the image side is concave;

[0012] The sixth lens is a positive lens, the object side of the sixth lens is convex, and the image side is convex;

[0013] The seventh lens is a negative lens, the object side of the seventh lens is concave, and the image side is convex;

[0014] The eighth lens is a positive lens, the object side of the eighth lens is convex, and the image side is concave;

[0015] Wherein, the first lens, the fourth lens, the fifth lens and the sixth lens are glass spherical lenses, the second lens, the third lens, the seventh lens and the eighth lens are plastic aspherical lenses, and the fifth lens and the sixth lens are adhesively connected.

[0016] In an embodiment, the focal length of the first lens is f1, -15 mm < f1 < -5 mm;

[0017] The focal length of the second lens is f2, -30 mm < f2 < -20 mm;

[0018] The focal length of the third lens is f3, 15 mm < f3 < 25 mm;

[0019] The focal length of the fourth lens is f4, 5 mm < f4 < 15 mm;

[0020] The focal length of the fifth lens is f5, -14 mm < f5 < -8 mm;

[0021] The focal length of the sixth lens is f6, 6 mm < f6 < 10 mm;

[0022] The focal length of the seventh lens is f7, -12 mm < f7 < -8 mm;

[0023] The focal length of the eighth lens is f8, 8 mm < f8 < 12 mm.

[0024] In an embodiment, the refractive index of the first lens is n1, the dispersion coefficient of the first lens is v1, 1.55 ≤ n1 ≤ 1.75; 50.0 ≤ v1 ≤ 70.0;

[0025] The refractive index of the second lens is n2, the dispersion coefficient of the second lens is v2, 1.50 ≤ n2 ≤ 1.60; 50.0 ≤ v2 ≤ 60.0;

[0026] The refractive index of the third lens is n3, and the dispersion coefficient of the third lens is v3, where 1.60 ≤ n3 ≤ 1.70; 18.0 ≤ v3 ≤ 28.0;

[0027] The refractive index of the fourth lens is n4, and the dispersion coefficient of the fourth lens is v4, where 1.50 ≤ n4 ≤ 1.75; 45.0 ≤ v4 ≤ 75.0;

[0028] The refractive index of the fifth lens is n5, and the dispersion coefficient of the fifth lens is v5, where 1.70 ≤ n5 ≤ 1.90; 18.0 ≤ v5 ≤ 35.0;

[0029] The refractive index of the sixth lens is n6, and the dispersion coefficient of the sixth lens is v6, where 1.40 ≤ n6 ≤ 1.65; 55.0 ≤ v6 ≤ 98.0;

[0030] The refractive index of the seventh lens is n7, and the dispersion coefficient of the seventh lens is v7, where 1.55 ≤ n7 ≤ 1.65; 18.0 ≤ v7 ≤ 28.0;

[0031] The refractive index of the eighth lens is n8, and the dispersion coefficient of the eighth lens is v8, where 1.50 ≤ n8 ≤ 1.60; 50.0 ≤ v8 ≤ 65.0.

[0032] In one embodiment, the overall optical length of the day-night confocal lens is TTL, and the effective focal length is FEL, where TTL ≤ 30 mm; TTL / EFL ≤ 7.1.

[0033] In one embodiment, the first lens is a negative lens, the object side of the first lens is convex, and the image side is concave;

[0034] The second lens is a negative lens, the object side of the second lens is concave, and the image side is convex;

[0035] The third lens is a positive lens, the object side of the third lens is convex, and the image side is convex;

[0036] The fourth lens is a positive lens, the object side of the fourth lens is convex, and the image side is concave;

[0037] The fifth lens is a positive lens, the object side of the fifth lens is convex, and the image side is convex;

[0038] The sixth lens is a negative lens, the object side of the sixth lens is concave, and the image side is concave;

[0039] The seventh lens is a positive lens, the object side of the seventh lens is convex, and the image side is convex;

[0040] The eighth lens is a positive lens. The object side surface of the eighth lens is concave, and the image side surface is convex.

[0041] Among them, the first lens, the third lens, the fifth lens, the sixth lens, and the seventh lens are glass spherical lenses. The second lens, the fourth lens, and the eighth lens are plastic aspherical lenses, and the sixth lens and the seventh lens are adhesively connected.

[0042] In one embodiment, the focal length of the first lens is f1, and -10 mm < f1 < -5 mm;

[0043] The focal length of the second lens is f2, and -15 mm < f2 < -8 mm;

[0044] The focal length of the third lens is f3, and 12 mm < f3 < 22 mm;

[0045] The focal length of the fourth lens is f4, and 15 mm < f4 < 25 mm;

[0046] The focal length of the fifth lens is f5, and -5 mm < f5 < 10 mm;

[0047] The focal length of the sixth lens is f6, and -7 mm < f6 < -3 mm;

[0048] The focal length of the seventh lens is f7, and 4 mm < f7 < 8 mm;

[0049] The focal length of the eighth lens is f8, and 150 mm < f8 < 300 mm.

[0050] In one embodiment, the refractive index of the first lens is n1, and the Abbe number of the first lens is v1, 1.51 ≤ n1 ≤ 1.75; 30.0 ≤ v1 ≤ 60.0;

[0051] The refractive index of the second lens is n2, and the Abbe number of the second lens is v2, 1.50 ≤ n2 ≤ 1.60; 50.0 ≤ v2 ≤ 60.0;

[0052] The refractive index of the third lens is n3, and the Abbe number of the third lens is v3, 1.50 ≤ n3 ≤ 1.70; 45.0 ≤ v3 ≤ 70.0;

[0053] The refractive index of the fourth lens is n4, and the Abbe number of the fourth lens is v4, 1.60 ≤ n4 ≤ 1.70; 18.0 ≤ v4 ≤ 28.0;

[0054] The refractive index of the fifth lens is n5, and the Abbe number of the fifth lens is v5, 1.50 ≤ n5 ≤ 1.75; 50.0 ≤ v5 ≤ 75.0;

[0055] The refractive index of the sixth lens is n6, and the dispersion coefficient of the sixth lens is v6, where 1.70 ≤ n6 ≤ 1.95; 18.0 ≤ v6 ≤ 35.0;

[0056] The refractive index of the seventh lens is n7, and the dispersion coefficient of the seventh lens is v7, where 1.40 ≤ n7 ≤ 1.70; 55.0 ≤ v7 ≤ 100.0;

[0057] The refractive index of the eighth lens is n8, and the dispersion coefficient of the eighth lens is v8, where 1.50 ≤ n8 ≤ 1.60; 50.0 ≤ v8 ≤ 65.0.

[0058] In one embodiment, the overall optical length of the day-night confocal lens is TTL, and the effective focal length is FEL, where TTL ≤ 30.5 mm; TTL / EFL ≤ 7.0.

[0059] The present invention also provides a photographing device including the above day-night confocal lens.

[0060] In the technical solution of the present invention, an optical system is composed of eight lenses. At the same time, the diameter of the first lens is controlled within 15 mm to control the aperture of the day-night confocal lens to meet the installation space requirements of the day-night confocal lens. Moreover, the aperture value of the day-night confocal lens is controlled within 1.6 so that the day-night confocal lens can also clearly image under low light conditions, and the day-night confocal lens can support the photosensitive chip with a size of 1 / 1.6 inch. The field of view angle of the day-night confocal lens can reach more than 144°, the image plane height of the day-night confocal lens can reach 10 mm, and the CRA is less than 10°, so that the day-night confocal lens has a large field of view angle, a wide field of view range, and does not defocus within the temperature difference range of -40°C to 80°C. To provide a lens with a large aperture, a large viewing angle, a small infrared defocus amount, and a day-night confocal function. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on the structures shown in these drawings without creative efforts.

[0062] Figure 1 It is a schematic structural diagram of the first embodiment of the day-night confocal lens provided by the present invention;

[0063] Figure 2 For Figure 1Schematic diagram of the vertical chromatic aberration curve of the day-night confocal lens in

[0064] Figure 3 is Figure 1 Schematic diagram of the ray aberration curve of the day-night confocal lens in

[0065] Figure 4 is Figure 1 Schematic diagram of the field curvature and distortion of the day-night confocal lens in

[0066] Figure 5 is Figure 1 20°C MTF diagram of the day-night confocal lens in

[0067] Figure 6 is Figure 1 20°C visible Through focus MTF diagram of the day-night confocal lens in

[0068] Figure 7 is Figure 1 20°C infrared Through focus MTF diagram of the day-night confocal lens in

[0069] Figure 8 is Figure 1 -40°C visible Through focus MTF diagram of the day-night confocal lens in

[0070] Figure 9 is Figure 1 80°C visible Through focus MTF diagram of the day-night confocal lens in

[0071] Figure 10 Schematic diagram of the structure of the second embodiment of the day-night confocal lens provided by the present utility model;

[0072] Figure 11 is Figure 10 Schematic diagram of the vertical chromatic aberration curve of the day-night confocal lens in

[0073] Figure 12 is Figure 10 Schematic diagram of the ray aberration curve of the day-night confocal lens in

[0074] Figure 13 is Figure 10 Schematic diagram of the field curvature and distortion of the day-night confocal lens in

[0075] Figure 14 is Figure 10 20°C MTF diagram of the day-night confocal lens in

[0076] Figure 15 is Figure 10Visible Through focus MTF diagram of the day-night confocal lens at 20°C;

[0077] Figure 16 is Figure 10 Infrared Through focus MTF diagram of the day-night confocal lens at 20°C;

[0078] Figure 17 is Figure 10 Visible Through focus MTF diagram of the day-night confocal lens at -40°C;

[0079] Figure 18 is Figure 10 Visible Through focus MTF diagram of the day-night confocal lens at 80°C.

[0080] Explanation of the reference numerals in the drawings:

[0081] 100, day-night confocal lens; 1, first lens; 2, second lens; 3, third lens; 4, fourth lens; 5, fifth lens; 6, sixth lens; 7, seventh lens; 8, eighth lens; 9, aperture; 10, filter; 11, protective glass; 12, photosensitive chip.

[0082] The realization, functional features and advantages of the purpose of the present utility model will be further described in conjunction with the embodiments and with reference to the accompanying drawings. Detailed implementation manners

[0083] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without making creative efforts shall fall within the protection scope of the present utility model.

[0084] It should be noted that if there are directional indications (such as up, down, left, right, front, back...) involved in the embodiments of the present utility model, the directional indications are only used to explain the relative positional relationship and movement conditions between the components in a specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0085] In addition, if the descriptions such as "first", "second", etc. are involved in the embodiments of the present utility model, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be construed as indicating or implying their relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first", "second" may explicitly or implicitly include at least one such feature. In addition, if "and / or" or "and / or" appears throughout the text, its meaning includes three parallel scenarios. Taking "A and / or B" as an example, it includes scenario A, or scenario B, or the scenario where both A and B are satisfied simultaneously. In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement them. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present utility model.

[0086] The present utility model provides a day-night confocal lens, aiming to solve the problems that the existing lenses cannot have large aperture, large target surface, good chromatic aberration and off-axis aberration at the same time, resulting in poor peripheral field performance and excessive infrared defocus, and the application scenario cannot utilize infrared light to increase the system light throughput, affecting the performance of the lens at night.

[0087] Please refer to Figure 1 and Figure 10 In an embodiment of the present utility model, the day-night confocal lens 100 has an object side and an image side arranged corresponding to each other along the optical axis direction. The day-night confocal lens 100 includes a first lens 1, a second lens 2, a diaphragm 9, a third lens 3, a fourth lens 4, a fifth lens 5, a sixth lens 6, a seventh lens 7, an eighth lens 8, a filter 10, a protective glass 11 and an image sensor 12 arranged in sequence from the object side to the image side. The surface of the image sensor 12 facing the object side is the image plane, so that the field of view angle of the day-night confocal lens 100 can reach more than 144°, the image plane height of the day-night confocal lens 100 can reach 10 mm, and the CRA is less than 10°. The diameter of the first lens 1 is D1, the aperture value of the day-night confocal lens 100 is F, and the day-night confocal lens 100 satisfies the following conditions: D1 < 15 mm; F ≤ 1.6.

[0088] In the technical solution of the present utility model, an optical system is composed of eight lenses. At the same time, the diameter of the first lens 1 is controlled within 15 mm to control the aperture of the day-night confocal lens 100 to meet the installation space requirements of the day-night confocal lens 100. Moreover, the aperture value of the day-night confocal lens 100 is controlled within 1.6, so that the day-night confocal lens 100 can also clearly image in low light, and the day-night confocal lens 100 can support the photosensitive chip 12 of 1 / 1.6 inch. The field of view angle of the day-night confocal lens 100 can reach more than 144°, the image plane height of the day-night confocal lens 100 can reach 10 mm, and the CRA is lower than 10°, so that the day-night confocal lens 100 has a large field of view angle, has a wider field of view range, and does not defocus within the temperature difference range of -40°C to 80°C. To provide a lens with a large aperture, a large viewing angle, a small infrared defocus amount, and a day-night confocal function.

[0089] In addition, in the embodiment of the present utility model, the diaphragm 9 provided between the second lens 2 and the third lens 3 can adjust the light flux according to the actual situation to improve the imaging quality.

[0090] At the same time, the setting of the protective glass 11 can provide effective protection for the photosensitive chip 12, and the setting of the filter 10 can effectively filter out stray light in non-working bands to reduce light noise, reduce difficulties for the subsequent optoelectronic module processing part, and thus improve the imaging quality.

[0091] It can be understood that the present utility model does not limit the specific types, specific focal length ranges, refractive indices, and dispersion coefficients of the first lens 1, the second lens 2, the third lens 3, the fourth lens 4, the fifth lens 5, the sixth lens 6, the seventh lens 7, and the eighth lens 8.

[0092] For example, please refer to Figure 1 , in the first embodiment of the present utility model, the first lens 1 is a negative lens, the second lens 2 is a negative lens, the third lens 3 is a positive lens, the fourth lens 4 is a positive lens, the fifth lens 5 is a positive lens, the sixth lens 6 is a positive lens, the seventh lens 7 is a negative lens, and the eighth lens 8 is a positive lens.

[0093] With such a setting, the first lens 1 with a negative optical power is beneficial to the contraction of the light rays of the optical system, thereby effectively increasing the field of view range of the day-night confocal lens 100.

[0094] Moreover, the fourth lens 4 with a positive optical power undertakes a large optical power of the day-night confocal lens, changes the propagation direction of the light beam, and is more beneficial to the imaging of the light beam on the image plane.

[0095] In a further embodiment of the present utility model, the object side surface of the first lens 1 is convex, and the image side surface is concave; the object side surface of the second lens 2 is concave, and the image side surface is convex; the object side surface of the third lens 3 is convex, and the image side surface is concave; the object side surface of the fourth lens 4 is convex, and the image side surface is convex; the object side surface of the fifth lens 5 is convex, and the image side surface is concave; the object side surface of the sixth lens 6 is convex, and the image side surface is convex; the object side surface of the seventh lens 7 is concave, and the image side surface is convex; the object side surface of the eighth lens 8 is convex, and the image side surface is concave. With such a setting, by comprehensively setting the optical power and the matching relationship of the shapes of multiple lenses in the day-night confocal lens 100, compactness and athermalization can be achieved.

[0096] It should also be noted that in this embodiment of the present utility model, the fifth lens 5 and the sixth lens 6 are adhesively connected. In this way, the chromatic aberration of the day-night confocal lens 100 can be better corrected.

[0097] Furthermore, the first lens 1, the fourth lens 4, the fifth lens 5, and the sixth lens 6 are glass spherical lenses. Glass lenses can well resist the problem of heat deformation of the lens, reduce the influence of temperature on the optical performance of the lens, and maintain the high precision of the lens for a long time; the second lens 2, the third lens 3, the seventh lens 7, and the eighth lens 8 are plastic aspherical lenses. Aspherical lenses have better curvature radius characteristics and have the advantages of improving distortion aberration and astigmatism aberration. After using aspherical lenses, the aberration that appears during imaging can be eliminated as much as possible, thereby improving the imaging quality of the lens. At the same time, using plastic aspherical lenses can also reduce the manufacturing cost of the projection optical system.

[0098] In addition, in the embodiment of the present utility model, the focal length of the first lens is f1, -15 mm < f1 < -5 mm; the focal length of the second lens is f2, -30 mm < f2 < -20 mm; the focal length of the third lens is f3, 15 mm < f3 < 25 mm; the focal length of the fourth lens is f4, 5 mm < f4 < 15 mm; the focal length of the fifth lens is f5, -14 mm < f5 < -8 mm; the focal length of the sixth lens is f6, 6 mm < f6 < 10 mm; the focal length of the seventh lens is f7, -12 mm < f7 < -8 mm; the focal length of the eighth lens is f8, 8 mm < f8 < 12 mm.

[0099] It should be noted that the present utility model does not limit the specific values of the focal lengths of the first lens 1 as f1, the second lens 2 as f2, the third lens 3 as f3, the fourth lens 4 as f4, the fifth lens 5 as f5, the sixth lens 6 as f6, the seventh lens 7 as f7, and the eighth lens 8 as f8. The specific values of the focal lengths of multiple lenses can be set to any value within a range, and can be selected according to needs during actual setting.

[0100] Furthermore, in the embodiments of the present utility model, the refractive index of the first lens 1 is n1, where 1.55 ≤ n1 ≤ 1.75; the refractive index of the second lens 2 is n2, where 1.50 ≤ n2 ≤ 1.60; the refractive index of the third lens 3 is n3, where 1.60 ≤ n3 ≤ 1.70; the refractive index of the fourth lens 4 is n4, where 1.50 ≤ n4 ≤ 1.75; the refractive index of the fifth lens 5 is n5, where 1.70 ≤ n5 ≤ 1.90; the refractive index of the sixth lens 6 is n6, where 1.40 ≤ n6 ≤ 1.65; the refractive index of the seventh lens 7 is n7, where 1.55 ≤ n7 ≤ 1.65; the refractive index of the eighth lens 8 is n8, where 1.50 ≤ n8 ≤ 1.60.

[0101] Similarly, the present utility model does not limit the specific values of the refractive indices of the first lens 1 as n1, the second lens 2 as n2, the third lens 3 as n3, the fourth lens 4 as n4, the fifth lens 5 as n5, the sixth lens 6 as n6, the seventh lens 7 as n7, and the eighth lens 8 as n8.

[0102] In the embodiments of the present utility model, the specific values of the refractive indices of the first lens 1 as n1, the second lens 2 as n2, the third lens 3 as n3, the fourth lens 4 as n4, the fifth lens 5 as n5, the sixth lens 6 as n6, the seventh lens 7 as n7, and the eighth lens 8 as n8 can also be set to any value within a range, and the present utility model does not limit this.

[0103] Furthermore, in the embodiment of the present utility model, the dispersion coefficient of the first lens 1 is v1, where 50.0 ≤ v1 ≤ 70.0; the dispersion coefficient of the second lens 2 is v2, where 50.0 ≤ v2 ≤ 60.0; the dispersion coefficient of the third lens 3 is v3, where 18.0 ≤ v3 ≤ 28.0; the dispersion coefficient of the fourth lens 4 is v4, where 45.0 ≤ v4 ≤ 75.0; the dispersion coefficient of the fifth lens 5 is v5, where 18.0 ≤ v5 ≤ 35.0; the dispersion coefficient of the sixth lens 6 is v6, where 55.0 ≤ v6 ≤ 98.0; the dispersion coefficient of the seventh lens 7 is v7, where 18.0 ≤ v7 ≤ 28.0; the dispersion coefficient of the eighth lens 8 is v8, where 50.0 ≤ v8 ≤ 65.0.

[0104] Of course, the present utility model also does not limit the specific values of the dispersion coefficient v1 of the first lens 1, the dispersion coefficient v2 of the second lens 2, the dispersion coefficient v3 of the third lens 3, the dispersion coefficient v4 of the fourth lens 4, the dispersion coefficient v5 of the fifth lens 5, the dispersion coefficient v6 of the sixth lens 6, the dispersion coefficient v7 of the seventh lens 7, and the dispersion coefficient v8 of the eighth lens 8.

[0105] In the embodiment of the present utility model, the specific values of the dispersion coefficient v1 of the first lens 1, the dispersion coefficient v2 of the second lens 2, the dispersion coefficient v3 of the third lens 3, the dispersion coefficient v4 of the fourth lens 4, the dispersion coefficient v5 of the fifth lens 5, the dispersion coefficient v6 of the sixth lens 6, the dispersion coefficient v7 of the seventh lens 7, and the dispersion coefficient v8 of the eighth lens 8 can also be set to any value within the range, and the present utility model does not limit this.

[0106] In addition, in this embodiment, the overall optical length of the day-night confocal lens 100 is TTL, the effective focal length is FEL, and TTL ≤ 30 mm; TTL / EFL ≤ 7.1.

[0107] In a specific embodiment, the focal length f of the day-night confocal lens 100 is 4.43 mm, the aperture value F is 1.6, the image plane diameter is 10.3 mm, and the diagonal field of view angle is 151°.

[0108] It should be noted that in this embodiment, the basic parameter tables of the lens surface types, curvature radii, thicknesses, refractive indices, dispersion coefficients, and semi-diameters of the day-night confocal lens 100 are shown in Table 1:

[0109] Table 1

[0110] Surface Serial Number Surface Type Radius of Curvature (mm) Thickness (mm) Refractive Index Dispersion Coefficient Semi-Diameter (mm) 1 Spherical Surface 25.032 0.700 1.66 57.3 6.121 2 Spherical Surface 4.381 3.812 3.832 3 Aspherical Surface -5.640 4.371 1.54 56.0 3.396 4 Aspherical Surface -12.674 0.279 3.269 STO Spherical Surface inf -0.229 3.189 6 Aspherical Surface 12.400 1.396 1.66 20.4 3.305 7 Aspherical Surface 81.941 0.112 3.227 8 Spherical Surface 13.666 4.903 1.57 71.3 6.400 9 Spherical Surface -9.998 0.083 6.400 10 Spherical Surface 19.256 0.500 1.81 25.4 4.200 11 Spherical Surface 6.204 3.506 1.44 94.5 4.200 12 Spherical Surface -7.705 1.503 4.200 13 Aspherical Surface -2.788 1.200 1.62 25.8 4.200 14 Aspherical Surface -5.245 0.112 4.200 15 Aspherical Surface 4.194 2.462 1.54 55.6 4.876 16 Aspherical Surface 12.473 2.322 5.155 17 Spherical Surface inf 0.370 1.52 64.2 5.159 18 Spherical Surface inf 2.000 5.159 19 Spherical Surface inf 0.500 1.52 64.2 5.162 20 Spherical Surface inf 0.100 5.162 21 Spherical Surface inf 5.163

[0111] Furthermore, in the present embodiment, since the second lens 2, the third lens 3, the seventh lens 7, and the eighth lens 8 are all aspherical lenses, the aspherical surface shapes of the aspherical lenses satisfy the following conditions:

[0112]

[0113] where z represents the axial sagittal height of the aspherical surface in the Z direction; y represents the height of the aspherical surface; c represents the curvature of the fitted spherical surface, numerically the reciprocal of the radius of curvature, k represents the conic coefficient, and the 4th-order term, 6th-order term, 8th-order term, 10th-order term, 12th-order term, 14th-order term, and 16th-order term respectively represent the high-order aspherical coefficients.

[0114] One set of design values of the aspherical coefficients in this embodiment is shown in Table 2 below:

[0115] Table 2

[0116]

[0117]

[0118] With such a setting, by combining different lenses with each other and reasonably distributing the optical power and the shape of the lenses, the day-night confocal lens has good performance such as a large aperture, a large viewing angle, a small infrared defocus amount, and very good thermal aberration correction, with a wider field of view and more sufficient data information obtained.

[0119] Figure 2 is a schematic diagram of the lateral chromatic aberration curve of the day-night confocal lens 100 in this embodiment; Figure 3 is a schematic diagram of the ray aberration curve of the day-night confocal lens 100 in this embodiment; Figure 4 is a schematic diagram of the field curvature and distortion of the day-night confocal lens 100 in this embodiment; Figure 5 is the 20°C MTF graph of the day-night confocal lens 100 in this embodiment; Figure 6 is the 20°C visible Through focus MTF graph of the day-night confocal lens 100 in this embodiment; Figure 7 is the 20°C infrared Through focus MTF graph of the day-night confocal lens 100 in this embodiment;

[0120] Figure 8 is the -40°C visible Through focus MTF graph of the day-night confocal lens 100 in this embodiment; Figure 9 is the 80°C visible Through focus MTF graph of the day-night confocal lens 100 in this embodiment.

[0121] It should be noted that Table 2 shows a design value of the aspheric coefficients of the lenses in the day-night confocal lens 100 in this embodiment. The specific numerical value of the aspheric coefficient design value can be adjusted according to the requirements of the product, and the present utility model does not limit this.

[0122] Please refer to Figure 2 , and in the second embodiment of the present utility model, the first lens 1 is a negative lens, the second lens 2 is a negative lens, the third lens 3 is a positive lens, the fourth lens 4 is a positive lens, the fifth lens 5 is a positive lens, the sixth lens 6 is a negative lens, the seventh lens 7 is a positive lens, and the eighth lens 8 is a positive lens.

[0123] With such a setting, the first lens 1 with a negative optical power is beneficial to the contraction of the light rays of the optical system, thereby effectively increasing the field of view of the day-night confocal lens 100.

[0124] Moreover, the fifth lens 5 with a positive optical power undertakes a relatively large optical power of the day-night confocal lens, changes the propagation direction of the light beam, and is more conducive to the light beam imaging on the image plane.

[0125] In a further embodiment of the present utility model, the object side of the first lens 1 is convex, the image side is concave, the object side of the second lens 2 is concave, the image side is convex, the object side of the third lens 3 is convex, the image side is convex, the object side of the fourth lens 4 is convex, the image side is concave, the object side of the fifth lens 5 is convex, the image side is convex, the object side of the sixth lens 6 is concave, the image side is concave, the object side of the seventh lens 7 is convex, the image side is convex, and the object side of the eighth lens 8 is concave, and the image side is convex. With such a setting, by comprehensively setting the optical powers and the cooperation relationship of the shapes of multiple lenses in the day-night confocal lens 100, compactness and athermalization can also be achieved.

[0126] It should also be noted that, in this embodiment of the present utility model, the sixth lens 6 and the seventh lens 7 are adhesively connected. In this way, the chromatic aberration of the day-night confocal lens 100 can be better corrected.

[0127] Furthermore, the first lens 1, the third lens 3, the fifth lens 5, the sixth lens 6, and the seventh lens 7 are glass spherical lenses, and the second lens 2, the fourth lens 4, and the eighth lens 8 are plastic aspheric lenses. The aspheric lens has better curvature radius characteristics and has the advantages of improving distortion aberration and astigmatism aberration. After using the aspheric lens, the aberration that appears during imaging can be eliminated as much as possible, thereby improving the imaging quality of the lens. At the same time, using plastic aspheric lenses can also reduce the manufacturing cost of the projection optical system.

[0128] In an embodiment of the present utility model, the focal length of the first lens is f1, -10 mm < f1 < -5 mm; the focal length of the second lens is f2, -15 mm < f2 < -8 mm; the focal length of the third lens is f3, 12 mm < f3 < 22 mm; the focal length of the fourth lens is f4, 15 mm < f4 < 25 mm; the focal length of the fifth lens is f5, -5 mm < f5 < 10 mm; the focal length of the sixth lens is f6, -7 mm < f6 < -3 mm; the focal length of the seventh lens is f7, 4 mm < f7 < 8 mm; the focal length of the eighth lens is f8, 150 mm < f8 < 300 mm.

[0129] It should be noted that the present utility model does not limit the specific values of the focal length f1 of the first lens 1, the focal length f2 of the second lens 2, the focal length f3 of the third lens 3, the focal length f4 of the fourth lens 4, the focal length f5 of the fifth lens 5, the focal length f6 of the sixth lens 6, the focal length f7 of the seventh lens 7, and the focal length f8 of the eighth lens 8. The specific values of the focal lengths of multiple lenses can be set to any value within the range, and can be selected according to needs during actual setting.

[0130] Furthermore, the refractive index of the first lens 1 is n1, 1.51 ≤ n1 ≤ 1.75; the refractive index of the second lens 2 is n2, 1.50 ≤ n2 ≤ 1.60; the refractive index of the third lens 3 is n3, 1.50 ≤ n3 ≤ 1.70; the refractive index of the fourth lens 4 is n4, 1.60 ≤ n4 ≤ 1.70; the refractive index of the fifth lens 5 is n5, 1.50 ≤ n5 ≤ 1.75; the refractive index of the sixth lens 6 is n6, 1.70 ≤ n6 ≤ 1.95; the refractive index of the seventh lens 7 is n7, 1.40 ≤ n7 ≤ 1.70; the refractive index of the eighth lens 8 is n8, 1.50 ≤ n8 ≤ 1.60.

[0131] Similarly, the present utility model does not limit the specific values of the refractive index n1 of the first lens 1, the refractive index n2 of the second lens 2, the refractive index n3 of the third lens 3, the refractive index n4 of the fourth lens 4, the refractive index n5 of the fifth lens 5, the refractive index n6 of the sixth lens 6, the refractive index n7 of the seventh lens 7, and the refractive index n8 of the eighth lens 8.

[0132] In an embodiment of the present utility model, the refractive index of the first lens 1 is n1, the refractive index of the second lens 2 is n2, the refractive index of the third lens 3 is n3, the refractive index of the fourth lens 4 is n4, the refractive index of the fifth lens 5 is n5, the refractive index of the sixth lens 6 is n6, the refractive index of the seventh lens 7 is n7, and the refractive index of the eighth lens 8 is n8. The specific values can also be set to any value within a range, and the present utility model does not limit this.

[0133] Furthermore, in an embodiment of the present utility model, the Abbe number of the first lens 1 is v1, 30.0 ≤ v1 ≤ 60.0; the Abbe number of the second lens 2 is v2, 50.0 ≤ v2 ≤ 60.0; the Abbe number of the third lens 3 is v3, 45.0 ≤ v3 ≤ 70.0; the Abbe number of the fourth lens 4 is v4, 18.0 ≤ v4 ≤ 28.0; the Abbe number of the fifth lens 5 is v5, 50.0 ≤ v5 ≤ 75.0; the Abbe number of the sixth lens 6 is v6, 18.0 ≤ v6 ≤ 35.0; the Abbe number of the seventh lens 7 is v7, 55.0 ≤ v7 ≤ 100.0; the Abbe number of the eighth lens 8 is v8, 50.0 ≤ v8 ≤ 65.0.

[0134] Of course, the present utility model also does not limit the specific values of the Abbe number of the first lens 1 being v1, the Abbe number of the second lens 2 being v2, the Abbe number of the third lens 3 being v3, the Abbe number of the fourth lens 4 being v4, the Abbe number of the fifth lens 5 being v5, the Abbe number of the sixth lens 6 being v6, the Abbe number of the seventh lens 7 being v7, and the Abbe number of the eighth lens 8 being v8.

[0135] In an embodiment of the present utility model, the Abbe number of the first lens 1 is v1, the Abbe number of the second lens 2 is v2, the Abbe number of the third lens 3 is v3, the Abbe number of the fourth lens 4 is v4, the Abbe number of the fifth lens 5 is v5, the Abbe number of the sixth lens 6 is v6, the Abbe number of the seventh lens 7 is v7, and the Abbe number of the eighth lens 8 is v8. The specific values can also be set to any value within a range, and the present utility model does not limit this.

[0136] In addition, in this embodiment, the overall optical length of the day-night confocal lens 100 is TTL, the effective focal length is FEL, and TTL ≤ 30.5 mm; TTL / EFL ≤ 7.0.

[0137] In a specific embodiment, the focal length f of the day-night confocal lens 100 is 4.33 mm, the aperture value F is 1.6, the image plane diameter is 9.9 m, and the diagonal field of view angle is 156.6°.

[0138] It should be noted that in this embodiment, the basic parameter table of each lens surface shape, curvature radius, thickness, refractive index, dispersion coefficient, and semi-diameter of the day-night confocal lens 100 is shown in Table 3 as follows:

[0139] Table 3

[0140] Surface Serial Number Surface Type Radius of Curvature (mm) Thickness (mm) Refractive Index Dispersion Coefficient Semi-Diameter (mm) 1 Spherical Surface 26.600 0.696 1.72 38.0 5.720 2 Spherical Surface 4.443 3.760 3.699 3 Aspherical Surface -4.654 4.108 1.54 56.0 3.118 4 Aspherical Surface -24.049 0.095 3.166 STO Spherical Surface inf 0.087 3.170 6 Spherical Surface 10.311 2.271 1.55 63.4 3.433 7 Spherical Surface -239.983 0.096 3.584 8 Aspherical Surface 8.586 2.833 1.67 19.3 3.740 9 Aspherical Surface 21.465 0.103 3.299 10 Spherical Surface 6.099 3.580 1.57 71.3 3.682 11 Spherical Surface -10.626 0.133 3.682 12 Spherical Surface -11.545 0.496 1.81 25.5 3.682 13 Spherical Surface 4.816 4.003 1.57 71.3 3.682 14 Spherical Surface -8.043 0.534 3.682 15 Aspherical Surface 35.373 3.421 1.54 55.6 3.766 16 Aspherical Surface 47.461 0.838 4.726 17 Spherical Surface inf 0.372 1.52 64.2 4.821 18 Spherical Surface inf 2.225 4.833 19 Spherical Surface inf 0.500 1.52 64.2 4.954 20 Spherical Surface inf 0.100 4.973 21 Spherical Surface inf 4.979

[0141] Furthermore, in this embodiment, since the second lens 2, the fourth lens 4, and the eighth lens 8 are aspherical lenses, the aspherical surface shapes of the aspherical lenses satisfy the following conditions:

[0142]

[0143] Where z represents the axial sagittal height in the Z direction of the aspherical surface; y represents the height of the aspherical surface; c represents the curvature of the fitted spherical surface, numerically the reciprocal of the curvature radius, k represents the conic coefficient, and the 4th-order term, 6th-order term, 8th-order term, 10th-order term, 12th-order term, 14th-order term, and 16th-order term respectively represent the high-order aspherical coefficients.

[0144] One set of design values of the aspherical coefficients in this embodiment is shown in Table 4 as follows:

[0145] Table 4

[0146] Surface Serial Number K 4th Order Term 6th Order Term 8th Order Term 10th Order Term 12th Order Term 14th Order Term 16th Order Term 3 -1.226 1.96E-03 -1.80E-05 6.93E-07 0.00E+00 0.00E+00 0.00E+00 0.00E+00 4 -0.999 4.84E-05 2.62E-05 -1.25E-06 0.00E+00 0.00E+00 0.00E+00 0.00E+00 8 -0.902 1.22E-03 -8.12E-07 7.19E-07 -1.27E-08 0.00E+00 0.00E+00 0.00E+00 9 -1.478 1.67E-03 5.69E-05 -1.26E-06 1.22E-07 0.00E+00 0.00E+00 0.00E+00 15 -14.542 -2.40E-03 -5.96E-05 4.68E-07 -1.32E-07 0.00E+00 0.00E+00 0.00E+00 16 3.610 -3.03E-03 1.03E-05 4.96E-07 -1.10E-08 0.00E+00 0.00E+00 0.00E+00

[0147] By setting it in this way, through the combination of different lenses and the reasonable distribution of the optical power and the shape of the lenses, the day-night confocal lens has good performance such as a large aperture, a large viewing angle, a small infrared defocus amount, and very good thermal aberration correction, with a wider field of view and more sufficient acquisition of data information.

[0148] Figure 11 It is a schematic diagram of the lateral chromatic aberration curve of the day-night confocal lens 100 in this embodiment; Figure 12 It is a schematic diagram of the ray aberration curve of the day-night confocal lens 100 in this embodiment; Figure 13 It is a schematic diagram of the field curvature and distortion of the day-night confocal lens 100 in this embodiment; Figure 14 It is the 20°C MTF graph of the day-night confocal lens 100 in this embodiment; Figure 15 It is the 20°C visible Through focus MTF graph of the day-night confocal lens 100 in this embodiment; Figure 16 It is the 20°C infrared Through focus MTF graph of the day-night confocal lens 100 in this embodiment; Figure 17 It is the -40°C visible Through focus MTF graph of the day-night confocal lens 100 in this embodiment; Figure 18This is the 80°C visible Through focus MTF graph of the day-night co-focus lens 100 in this embodiment.

[0149] It should be noted that Table 4 shows a design value of the aspheric coefficients of the lenses in the day-night co-focus lens 100 in this embodiment. The specific numerical values of the design values of the aspheric coefficients can be adjusted according to the requirements of the product, and the present utility model places no restrictions thereon.

[0150] The present utility model also proposes a photographing device, which includes a day-night co-focus lens. The specific structure of the day-night co-focus lens refers to the above embodiments. Since this photographing device adopts all the technical solutions of the above embodiments, it has at least all the beneficial effects brought by the technical solutions of the above embodiments, which will not be elaborated herein one by one.

[0151] The above description is only an exemplary embodiment of the present utility model, and does not limit the patent scope of the present utility model. Any equivalent structural transformation made by using the content of the specification and drawings of the present utility model under the technical concept of the present utility model, or any direct / indirect application in other related technical fields is included in the patent protection scope of the present utility model.

Claims

1. A day and night confocal lens, characterized in that: The day-night confocal lens has an object side and an image side correspondingly arranged along the optical axis direction. The day-night confocal lens comprises a first lens, a second lens, an aperture, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, a filter, a protective glass and a photosensitive chip arranged in sequence from the object side to the image side. The surface of the photosensitive chip facing the object side is an image plane, so that the field angle of the day-night confocal lens can reach more than 144°, the image plane height of the day-night confocal lens can reach 10 mm, and the CRA is less than 10°. The diameter of the first lens is D1, and the aperture value of the day-night confocal lens is F. The day-night confocal lens meets the following conditions: D1<15mm;F≤1.

6.

2. The day and night confocal lens according to claim 1, characterized in that: The first lens is a negative lens, the object side surface of the first lens is convex, and the image side surface is concave; The second lens is a negative lens, the object side surface of the second lens is a concave surface, and the image side surface is a convex surface; The third lens is a positive lens, the object side surface of the third lens is convex, and the image side surface is concave; The fourth lens is a positive lens, the object side surface of the fourth lens is a convex surface, and the image side surface is a convex surface; The fifth lens is a positive lens, the object side surface of the fifth lens is a convex surface, and the image side surface is a concave surface; The sixth lens is a positive lens, the object side surface of the sixth lens is a convex surface, and the image side surface is a convex surface; The seventh lens is a negative lens, the object side surface of the seventh lens is a concave surface, and the image side surface is a convex surface; The eighth lens is a positive lens, the object side surface of the eighth lens is a convex surface, and the image side surface is a concave surface; The first lens, the fourth lens, the fifth lens and the sixth lens are glass spherical lenses, the second lens, the third lens, the seventh lens and the eighth lens are plastic aspherical lenses, and the fifth lens and the sixth lens are glued together.

3. The day and night confocal lens according to claim 2, characterized in that: The focal length of the first lens is f1, -15mm <f1<-5mm; The focal length of the second lens is f2, -30mm <f2<-20mm; The focal length of the third lens is f3, 15mm <f3<25mm; The focal length of the fourth lens is f4,5mm <f4<15mm; The focal length of the fifth lens is f5, -14mm <f5<-8mm; The focal length of the sixth lens is f6,6mm <f6<10mm; The focal length of the seventh lens is f7, -12mm <f7<-8mm; The focal length of the eighth lens is f8,8mm <f8<12mm。 4. The day and night confocal lens according to claim 2, characterized in that: The refractive index of the first lens is n1, the dispersion coefficient of the first lens is v1, 1.55≤n1≤1.75; 50.0≤v1≤70.0; The refractive index of the second lens is n2, the dispersion coefficient of the second lens is v2, 1.50≤n2≤1.60; 50.0≤v2≤60.0; The refractive index of the third lens is n3, the dispersion coefficient of the third lens is v3, 1.60≤n3≤1.70; 18.0≤v3≤28.0; The refractive index of the fourth lens is n4, the dispersion coefficient of the fourth lens is v4, 1.50≤n4≤1.75; 45.0≤v4≤75.0; The refractive index of the fifth lens is n5, the dispersion coefficient of the fifth lens is v5, 1.70≤n5≤1.90; 18.0≤v5≤35.0; The refractive index of the sixth lens is n6, the dispersion coefficient of the sixth lens is v6, 1.40≤n6≤1.65; 55.0≤v6≤98.0; The refractive index of the seventh lens is n7, the dispersion coefficient of the seventh lens is v7, 1.55≤n7≤1.65; 18.0≤v7≤28.0; The refractive index of the eighth lens is n8, the dispersion coefficient of the eighth lens is v8, 1.50≤n8≤1.60; 50.0≤v8≤65.

0.

5. The day and night confocal lens according to claim 2, characterized in that: The total optical length of the day-night confocal lens is TTL, the effective focal length is FEL, TTL≤30mm; TTL / EFL≤7.

1.

6. The day and night confocal lens according to claim 1, characterized in that: The first lens is a negative lens, the object side surface of the first lens is convex, and the image side surface is concave; The second lens is a negative lens, the object side surface of the second lens is a concave surface, and the image side surface is a convex surface; The third lens is a positive lens, the object side surface of the third lens is a convex surface, and the image side surface is a convex surface; The fourth lens is a positive lens, the object side surface of the fourth lens is a convex surface, and the image side surface is a concave surface; The fifth lens is a positive lens, the object side surface of the fifth lens is a convex surface, and the image side surface is a convex surface; The sixth lens is a negative lens, the object side surface of the sixth lens is a concave surface, and the image side surface is a concave surface; The seventh lens is a positive lens, the object side surface of the seventh lens is a convex surface, and the image side surface is a convex surface; The eighth lens is a positive lens, the object side surface of the eighth lens is a concave surface, and the image side surface is a convex surface; The first lens, the third lens, the fifth lens, the sixth lens and the seventh lens are glass spherical lenses, the second lens, the fourth lens and the eighth lens are plastic aspherical lenses, and the sixth lens and the seventh lens are glued together.

7. The day and night confocal lens according to claim 6, characterized in that: The focal length of the first lens is f1, -10mm <f1<-5mm; The focal length of the second lens is f2, -15mm <f2<-8mm; The focal length of the third lens is f3, 12mm <f3<22mm; The focal length of the fourth lens is f4,15mm <f4<25mm; The focal length of the fifth lens is f5, -5mm <f5<10mm; The focal length of the sixth lens is f6, -7mm <f6<-3mm; The focal length of the seventh lens is f7,4mm <f7<8mm; The focal length of the eighth lens is f8, 150mm <f8<300mm。 8. The day and night confocal lens according to claim 6, characterized in that: The refractive index of the first lens is n1, the dispersion coefficient of the first lens is v1, 1.51≤n1≤1.75; 30.0≤v1≤60.0; The refractive index of the second lens is n2, the dispersion coefficient of the second lens is v2, 1.50≤n2≤1.60; 50.0≤v2≤60.0; The refractive index of the third lens is n3, the dispersion coefficient of the third lens is v3, 1.50≤n3≤1.70; 45.0≤v3≤70.0; The refractive index of the fourth lens is n4, the dispersion coefficient of the fourth lens is v4, 1.60≤n4≤1.70; 18.0≤v4≤28.0; The refractive index of the fifth lens is n5, the dispersion coefficient of the fifth lens is v5, 1.50≤n5≤1.75; 50.0≤v5≤75.0; The refractive index of the sixth lens is n6, the dispersion coefficient of the sixth lens is v6, 1.70≤n6≤1.95; 18.0≤v6≤35.0; The refractive index of the seventh lens is n7, the dispersion coefficient of the seventh lens is v7, 1.40≤n7≤1.70; 55.0≤v7≤100.0; The refractive index of the eighth lens is n8, the dispersion coefficient of the eighth lens is v8, 1.50≤n8≤1.60; 50.0≤v8≤65.

0.

9. The day and night confocal lens according to claim 6, characterized in that: The total optical length of the day-night confocal lens is TTL, the effective focal length is FEL, TTL≤30.5mm; TTL / EFL≤7.

0.

10. A photographing device, characterized in that: Comprising the day and night confocal lens as described in any one of claims 1 to 9.

Images