Ultraviolet-to-visible large field of view low-distortion optical lens

Abstract

The application discloses an ultraviolet-to-visible large-view-field low-distortion optical lens and belongs to the technical field of imaging lenses. The optical lens comprises, in sequence along an optical axis from a subject side to an imaging side, a front lens group, an aperture diaphragm, a seventh lens, a cemented lens group and a rear lens. The cemented lens group comprises, in sequence along the optical axis from the subject side to the imaging side, a first cemented biconvex positive lens, a cemented biconcave negative lens and a second cemented biconvex positive lens. The subject side and the image side of the first cemented biconvex positive lens are both convex, the subject side and the image side of the cemented biconcave negative lens are both concave, and the subject side and the image side of the second cemented biconvex positive lens are both convex. The optical power of the front lens group, the seventh lens, the cemented lens group and the rear lens is reasonably distributed, so that the ultraviolet-to-near-infrared large-view-field low-distortion imaging lens with a large field of view, low distortion, an image far from the center, and good imaging quality is formed, and the ultraviolet-to-near-infrared large-view-field low-distortion imaging lens is particularly suitable for the multispectral large-view-field imaging field of a spectrometer, a polarization camera and the like.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of imaging lenses, in particular to a large field of view low-distortion optical lens from ultraviolet to visible. BACKGROUND

[0002] In recent years, with the rapid development of remote sensing detection technology, the demand for large field of view, wide width and multi-band detection is becoming more and more urgent, thereby higher requirements are put forward for the matching imaging lens.

[0003] In order to meet the actual application requirements, the imaging lens is usually required to have the characteristics of large field of view, wide spectral range, long back intercept, low distortion, compact structure, etc. Due to the sharp increase of aberration caused by the increase of field of view, especially the correction of distortion is very difficult, and the aspheric surface is usually introduced to balance the distortion and astigmatism at a position far away from the field stop.

[0004] A kind of optical lens for aerospace disclosed in application No. CN112817119A includes first lens to tenth lens arranged in order from object side to image side, all lenses adopt separated structure, wherein first lens and tenth lens adopt glass aspheric surface, with characteristics of large field of view, image side telecentricity, good imaging quality, etc., however, edge field of view distortion is about 40%, the distortion value is large, which greatly improves the difficulty of geometric calibration and correction. A large field of view low-distortion lens is proposed by Xi'an Institute of Optics and Fine Mechanics of Chinese Academy of Sciences, including reverse telephoto group, double Gauss mirror group and exit mirror group coaxially arranged in order along the light incidence direction, a total of 3 aspheric surfaces, 2 cemented mirror groups, maximum distortion is less than 4.7%, outer dimension is ≤Φ28×56mm, small volume, can realize good imaging quality under-40℃-60℃ temperature condition, but the lens does not have the characteristics of image side telecentricity, resulting in significant decrease of edge illumination, and the maximum field of view is only 115°, which still needs to be improved.

[0005] The existing large field of view imaging lens has the technical problems of large distortion and low edge illumination, which is not suitable for multispectral large field of view imaging fields such as spectrometer and polarization camera. SUMMARY

[0006] In order to solve the technical problems of large distortion and low edge illumination of the existing large field of view imaging lens, the purpose of the present application is to provide a large field of view low-distortion imaging lens from ultraviolet to near-infrared with large field of view angle, low distortion, image side telecentricity and good imaging quality, especially suitable for multispectral large field of view imaging fields such as spectrometer and polarization camera.

[0007] The purpose of the present application can be achieved by the following technical solutions:

[0008] An ultraviolet-to-visible large-view-field low-distortion optical lens comprises, in order from the object side to the imaging side along the optical axis, a front lens group, an aperture diaphragm, a seventh lens, a cemented lens group, and a rear lens, the cemented lens group comprising, in order from the object side to the imaging side along the optical axis, a first cemented double-convex positive lens, a cemented double-concave negative lens, and a second cemented double-convex positive lens, the object side and the image side of the first cemented double-convex positive lens are both convex, the object side and the image side of the cemented double-concave negative lens are both concave, and the object side and the image side of the second cemented double-convex positive lens are both convex, wherein the image side of the first cemented double-convex positive lens is cemented with the object side of the cemented double-concave negative lens, the image side of the cemented double-concave negative lens is cemented with the object side of the second cemented double-convex positive lens, and the optical power of the cemented lens group satisfies 0.04≤absolute value of optical power≤0.08.

[0009] As a further scheme of the present application, the refractive index of the first cemented double-convex positive lens ranges from 1.40 to 1.45, and the dispersion ranges from 80 to 95; the refractive index of the cemented double-concave negative lens ranges from 1.85 to 1.90, and the dispersion ranges from 30 to 45; and the refractive index of the second cemented double-convex positive lens ranges from 1.40 to 1.45, and the dispersion ranges from 80 to 95.

[0010] As a further scheme of the present application, the front lens group comprises:

[0011] a first lens with negative optical power, the object side of which is convex, and the image side of which is concave, and the absolute value of the optical power ranges from 0.005 to 0.01, and the light passing aperture of the first lens is less than 120 mm;

[0012] a second lens with negative optical power, the object side of which is convex, and the image side of which is concave, and the absolute value of the optical power ranges from 0.01 to 0.03;

[0013] a third lens with negative optical power, the object side of which is a plane, and the image side of which is concave, and the absolute value of the optical power ranges from 0.01 to 0.02;

[0014] a fourth lens with negative optical power, the object side and the image side of which are both concave, and the absolute value of the optical power ranges from 0.02 to 0.04;

[0015] a fifth lens with positive optical power, the object side of which is concave, and the image side of which is convex, and the absolute value of the optical power ranges from 0.01 to 0.02;

[0016] a sixth lens with positive optical power, the object side and the image side of which are both convex, and the absolute value of the optical power ranges from 0.01 to 0.02;

[0017] the first lens to the sixth lens are arranged in order from the object side to the imaging side along the optical axis.

[0018] As a further scheme of the present application: the first lens has a refractive index range of 1.40≤n≤1.55 and a dispersion range of 70≤ν≤90; the second lens has a refractive index range of 1.60≤n≤1.70 and a dispersion range of 55≤ν≤65; the third lens has a refractive index range of 1.60≤n≤1.70 and a dispersion range of 55≤ν≤65; the fourth lens has a refractive index range of 1.65≤n≤1.80 and a dispersion range of 25≤ν≤40; the fifth lens has a refractive index range of 1.60≤n≤1.70 and a dispersion range of 40≤ν≤45; and the sixth lens has a refractive index range of 1.60≤n≤1.70 and a dispersion range of 40≤ν≤45.

[0019] As a further scheme of the present application: the image side surface of the second lens and the image side surface of the rear lens are both aspherical surfaces.

[0020] As a further scheme of the present application: the aspherical surface of the second lens and the aspherical surface of the rear lens satisfy the equation:

[0021]

[0022] wherein z is the sag of the aspherical surface, c is the vertex curvature of the aspherical surface, y is the aperture, k is the conic coefficient, A4 is the 4th order aspherical coefficient, A6 is the 6th order aspherical coefficient, A8 is the 8th order aspherical coefficient, A10 is the 10th order aspherical coefficient. 10

[0023] As a further scheme of the present application: the seventh lens is a positive meniscus lens with positive focal power, 0.01≤absolute value of focal power≤0.04, and the seventh lens has a refractive index range of 1.65≤n≤1.80 and a dispersion range of 25≤ν≤40.

[0024] As a further scheme of the present application: the rear lens is a biconvex lens with negative focal power, both the object side surface and the image side surface of the rear lens are convex surfaces, 0.05≤absolute value of focal power≤0.08, and the rear lens has a refractive index range of 1.60≤n≤1.70 and a dispersion range of 55≤ν≤65.

[0025] As a further scheme of the present application: the effective focal length f of the optical lens satisfies: 4≤f / EPD, the back focal length BFL of the optical lens satisfies: 0.08≤BFL / TTL≤0.15, and the relative distortion DIST of the optical lens satisfies: DIST≤2.5%.

[0026] As a further scheme of the present application: the chief ray angle of all fields of view at the image plane CRA satisfies: CRA≤3°. ​

[0027] Advantages of the present application:

[0028] (1) The present application provides a large field of view low distortion optical lens from ultraviolet to visible, which comprises a front lens group, an aperture stop, a seventh lens, a cemented lens group and a rear lens arranged along the optical axis from the object side to the imaging side in sequence. By reasonably distributing the refractive power of the front lens group, the seventh lens, the cemented lens group and the rear lens, a large field of view low distortion imaging lens from ultraviolet to near infrared with large field of view, low distortion, telecentric on the image side and good imaging quality is formed, which is particularly suitable for multispectral large field of view imaging fields such as spectrometer, polarization camera and the like.

[0029] (2) In the present application, both the second lens and the rear lens adopt single-sided aspheric surface, which reduces the pressure of correcting distortion and astigmatism of single aspheric surface, solves the problem of great difficulty in processing aspheric surface caused by large sag of traditional single aspheric surface, and the aspheric surface in the present application meets the current aspheric surface processing technology and has strong engineering realizability.

[0030] (3) By using low refractive index and low dispersion material, the present application solves the chromatic aberration problem caused by wide band optical system, and the maximum lateral chromatic aberration is less than 15um. In addition, by constraining the incidence angle of the chief ray of the edge field of view, telecentricity on the image side is realized, and the uniformity of illumination of the edge field of view is improved. The rear intercept of the optical lens in the present application is greater than 25mm, which reserves enough space for the installation of the detector.

[0031] (4) In the present application, by reasonably distributing the refractive power of the cemented lens, the incidence angle of the chief ray on each surface of the cemented lens is not greater than 35°, and the aberration correction ability borne by each surface of the cemented lens is relatively balanced, which reduces the tolerance sensitivity of processing and adjustment, and the yield of the imaging lens is high. BRIEF DESCRIPTION OF DRAWINGS

[0032] The present application will be further described below in combination with the drawings.

[0033] Figure 1 is a schematic diagram of the structure of the ultraviolet to visible large field of view low distortion optical lens of the present application;

[0034] Figure 2 is a schematic diagram of the structure of the front lens group of the present application;

[0035] Figure 3 is a schematic diagram of the structure of the aperture stop, the seventh lens, the cemented lens group and the rear lens of the present application;

[0036] Figure 4 is the modulation transfer function (MTF) curve of the ultraviolet to visible large field of view low distortion optical lens of the present application;

[0037] Figure 5is a relative distortion curve of the ultraviolet-to-visible large field of view low-distortion optical lens of the present application;

[0038] Figure 6 is a lateral chromatic aberration curve of the ultraviolet-to-visible large field of view low-distortion optical lens of the present application.

[0039] In the figure: 1, front lens group; 11, first lens; 12, second lens; 13, third lens; 14, fourth lens; 15, fifth lens; 16, sixth lens; 2, aperture stop; 3, seventh lens; 4, cemented lens group; 41, No. 1 cemented biconvex positive lens; 42, cemented biconcave negative lens; 43, No. 2 cemented biconvex positive lens; 5, rear lens. DETAILED DESCRIPTION

[0040] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0041] Please refer to Figure 1 The embodiments of the present application provide an ultraviolet-to-visible large field of view low-distortion optical lens, which comprises a front lens group 1, an aperture stop 2, a seventh lens 3, a cemented lens group 4 and a rear lens 5 arranged in sequence along the optical axis from the object side to the imaging side.

[0042] Specifically, please refer to Figure 2 In the present embodiment, the front lens group 1 comprises a first lens 11, a second lens 12, a third lens 13, a fourth lens 14, a fifth lens 15 and a sixth lens 16 arranged in sequence along the optical axis from the object side to the imaging side.

[0043] The first lens 11 is a meniscus lens with negative refractive power, the object side surface of which is convex, and the image side surface of which is concave, 0.005≤absolute value of refractive power≤0.01, and the light aperture of the first lens 11 is less than 120 mm. In the present embodiment, the absolute value of refractive power of the first lens 11 is preferably 0.0075, and can also be a refractive power value within other ranges of refractive power. The refractive index of the first lens 11 is in the range of 1.40≤n≤1.50, and the dispersion is in the range of 70≤ν≤90. In the present embodiment, the first lens 11 is preferably a glass material of N-PK51 type, the refractive index of which is 1.53, and the dispersion of which is 76.98, and can also be a glass material within other ranges of refractive index and dispersion.

[0044] The second lens element 12 is a meniscus lens with negative optical power, with a convex object-side surface and a concave image-side surface. The absolute value of the optical power is 0.01 ≤ ≤ 0.03. In this embodiment, the absolute value of the optical power of the second lens element 12 is preferably 0.023, but other optical power values ​​within the optical power range are also acceptable. The refractive index of the second lens element 1212 is in the range of 1.60 ≤ n ≤ 1.70, and the dispersion range is 50 ≤ ν ≤ 65. In this embodiment, the second lens element 12 is preferably made of N-SK14 glass, with a refractive index of 1.60 and a dispersion of 60.60. Other glass materials within the refractive index and dispersion ranges are also acceptable.

[0045] The third lens element 13 is a plano-concave lens with negative optical power, with a flat object-side surface and a concave image-side surface. The absolute value of the optical power is 0.01 ≤ ≤ 0.03. In this embodiment, the absolute value of the optical power of the third lens element 13 is preferably 0.016, but other optical power values ​​within the optical power range are also acceptable. The refractive index range of the third lens element 13 is 1.60 ≤ n ≤ 1.70, and the dispersion range is 50 ≤ ν ≤ 65. In this embodiment, the third lens element is preferably made of 13N-SK14 glass, with a refractive index of 1.60 and a dispersion of 60.60. Other glass materials within the refractive index and dispersion ranges are also acceptable.

[0046] The fourth lens element 14 is a biconcave lens with negative optical power, with both its object-side and image-side surfaces concave. The absolute value of the optical power is 0.02 ≤ ≤ 0.04. In this embodiment, the absolute value of the optical power of the fourth lens element 14 is preferably 0.022, but other optical power values ​​within this range are also acceptable. The refractive index of the fourth lens element 14 is in the range of 1.65 ≤ n ≤ 1.80, and the dispersion is in the range of 25 ≤ v ≤ 40. In this embodiment, the fourth lens element 14 is preferably made of N-SF15 glass, with a refractive index of 1.70 and a dispersion of 30.20. Other glass materials within this refractive index and dispersion ranges are also acceptable.

[0047] The fifth lens element 15 is a meniscus lens with positive optical power, with a concave object-side surface and a convex image-side surface. The absolute value of the optical power is 0.01 ≤ ≤ 0.02. In this embodiment, the absolute value of the optical power of the fifth lens element 15 is preferably 0.011, but other optical power values ​​within this range are also acceptable. The refractive index of the fifth lens element 15 is in the range of 1.60 ≤ n ≤ 1.70, and the dispersion is in the range of 40 ≤ ν ≤ 45. In this embodiment, the fifth lens element 15 is preferably made of N-KZFS4 glass, with a refractive index of 1.61 and a dispersion of 44.49. Other glass materials within this refractive index and dispersion ranges are also acceptable.

[0048] The sixth lens 16 is a biconvex lens with positive refractive power, both the object side surface and the image side surface of which are convex, and the absolute value of the refractive power is 0.01 to 0.02. In the embodiment, the absolute value of the refractive power of the sixth lens 16 is preferably 0.011, and can also be a refractive power value within another refractive power range. The refractive index of the sixth lens 16 is 1.60 to 1.70, and the dispersion is 40 to 45. In the embodiment, the sixth lens 16 is preferably made of a glass material of N-KZFS4 type, the refractive index of which is 1.61 and the dispersion of which is 44.49, and can also be made of a glass material within another refractive index range and dispersion range.

[0049] Specifically, in the embodiment, the seventh lens 3 is a positive meniscus lens with positive refractive power, the object side surface of which is concave and the image side surface of which is convex, and the absolute value of the refractive power is 0.01 to 0.04. In the embodiment, the absolute value of the refractive power of the seventh lens 3 is preferably 0.014, and can also be a refractive power value within another refractive power range. The refractive index of the seventh lens 3 is 1.65 to 1.80, and the dispersion is 25 to 40. In the embodiment, the seventh lens 3 is preferably made of a glass material of N-SF15 type, the refractive index of which is 1.70 and the dispersion of which is 30.20, and can also be made of a glass material within another refractive index range and dispersion range.

[0050] Please refer to Figure 3 In the embodiment, the cemented lens group 4 includes a first cemented biconvex positive lens 41, a cemented biconcave negative lens 42 and a second cemented biconvex positive lens 43 which are sequentially arranged along the optical axis from the object side to the imaging side. The object side surface and the image side surface of the first cemented biconvex positive lens 41 are both convex, the object side surface and the image side surface of the cemented biconcave negative lens 42 are both concave, and the object side surface and the image side surface of the second cemented biconvex positive lens 43 are both convex. The image side surface of the first cemented biconvex positive lens 41 is cemented with the object side surface of the cemented biconcave negative lens 42, and the image side surface of the cemented biconcave negative lens 42 is cemented with the object side surface of the second cemented biconvex positive lens 43. The absolute value of the refractive power of the cemented lens group 4 is 0.04 to 0.08. In the embodiment, the absolute value of the refractive power of the cemented lens group 4 is preferably 0.062, and can also be a refractive power value within another refractive power range.

[0051] The refractive index of the first cemented biconvex positive lens 41 is in the range of 1.40≤n≤1.45, and the dispersion is in the range of 80≤v≤95. In the embodiment, the first cemented biconvex positive lens 41 is preferably made of N-FK58 glass material, the refractive index of which is 1.46, and the dispersion is 90.90. Alternatively, the first cemented biconvex positive lens 41 can be made of other glass material with refractive index and dispersion in the above range.

[0052] Specifically, in the embodiment, the rear lens 5 is a biconvex lens with negative focal power, both the object side and the image side of which are convex, and the absolute value of the focal power is in the range of 0.05≤absolute value of focal power≤0.08. In the embodiment, the absolute value of the focal power of the rear lens 5 is preferably 0.076. Alternatively, the absolute value of the focal power of the rear lens 5 can be in the range of other focal power values. The refractive index of the rear lens 5 is in the range of 1.60≤n≤1.70, and the dispersion is in the range of 55≤v≤65. In the embodiment, the rear lens 5 is preferably made of N-SK14 glass material, the refractive index of which is 1.60, and the dispersion is 60.60. Alternatively, the rear lens 5 can be made of other glass material with refractive index and dispersion in the above range.

[0053] The surface parameters of all the lenses in the embodiment are as follows:

[0054] Surface Surface type Radius of curvature Center thickness Material 1 Sphere 85.55 7.50 N-PK51 2 Sphere 37.12 18.76 3 Sphere 83.13 5.00 N-SK14 4 Asphere 19.68 22.31 5 Sphere Infinity 4.13 N-SK14 6 Sphere 38.67 12.05 7 Sphere -36.89 9.30 N-SF15 8 Sphere 239.42 12.59 9 Sphere -115.90 11.71 N-KZFS4 10 Sphere -38.78 1.03 11 Sphere 57.32 9.23 N-KZFS4 12 Sphere -2795.61 69.30 13 (aperture stop) —— Infinity 1.12 14 Sphere -34.96 3.00 N-SF15 15 Sphere -21.23 1.00 16 Sphere 57.89 3.50 N-FK58 17 Sphere -8.54 5.07 N-LASF31A 18 Sphere 21.32 2.83 N-FK58 19 Sphere -34.07 0.26 20 Sphere 38.17 5.33 N-SK14 21 Asphere -10.57 26

[0055] It is worth noting that, in the embodiment, the image side of the second lens and the image side of the rear lens are both aspherical surfaces, and the aspherical surface of the second lens and the aspherical surface of the rear lens satisfy the equation, and the aspherical surface equation is

[0056]

[0057] wherein z is the sag of the aspherical surface, c is the vertex curvature of the aspherical surface, y is the aperture, k is the conic coefficient, A4 is the 4th order aspherical coefficient, A6 is the 6th order aspherical coefficient, A8 is the 8th order aspherical coefficient, A10 is the 10th order aspherical coefficient. 10

[0058] In the embodiment, the two aspherical coefficients are as follows:

[0059] Serial number Element type k A4 A6 A8 A10 4 Asphere -1.00 0 0 0 0 21 Asphere -0.92 0 0 0 0 ​

[0060] The effective focal length of the imaging lens of the embodiment is f=3.5mm, the full field of view is 118°, the working waveband is 380-865nm, the F-number, i.e. the ratio of the effective focal length f to the entrance pupil diameter ENPD, is 4.3, the total optical length is 230mm, the first lens has a clear aperture of 105mm, the incidence angle CRA of all field chief rays on the image plane is not greater than 2°, a large field of view, image far field, and an edge field of view image plane illumination better than 85% are achieved, and the imaging lens of the embodiment can be applied to a long-slit imaging spectrometer front objective lens, a multi-angle multi-spectral polarization camera and other multi-spectral large field of view imaging fields.

[0061] As shown in Figure 4 the modulation transfer function (MTF) curve of the ultraviolet-to-visible large field of view low distortion optical lens provided by the embodiment is shown, the horizontal coordinate represents the spatial frequency, and the unit is line per millimeter (lp / mm), and the vertical coordinate represents the MTF value. The figure shows that the MTF of all fields of view is greater than 0.70 at a spatial frequency of 42 lp / mm, indicating that the optical lens has good imaging quality on the entire image plane.

[0062] As shown in Figure 5 the distortion curve of the ultraviolet-to-visible large field of view low distortion optical lens provided by the embodiment is shown, the horizontal coordinate is the relative distortion, and the vertical coordinate is the field of view, Figure 4 The figure shows that the relative distortion DI ST of all fields of view is less than 2%.

[0063] As shown in Figure 6 the lateral chromatic aberration curve of the ultraviolet-to-visible large field of view low distortion optical lens provided by the embodiment is shown, the horizontal coordinate represents the lateral chromatic aberration, and the vertical coordinate represents the normalized field of view. Figure 5 The figure shows that the lateral chromatic aberration of the ultraviolet-to-visible large field of view low distortion optical lens provided by the embodiment is less than 7um, and the lateral chromatic aberration is well corrected.

[0064] The preferred embodiments of the present application are described in detail above, which cannot be considered as limiting the scope of the implementation of the present application. Any equivalent changes and improvements made in the scope of the present application should still belong to the patent scope of the present application.

Claims

1. A low-distortion optical lens with a wide field of view from ultraviolet to visible light, characterized by: The invention comprises a front lens group, an aperture stop, a seventh lens, a cemented lens group and a rear lens, which are sequentially spaced from the object side to the imaging side along the optical axis. The cemented lens group comprises a first cemented biconvex positive lens, a cemented biconcave negative lens and a second cemented biconvex positive lens, which are sequentially bonded from the object side to the imaging side along the optical axis. The object side surface and the image side surface of the first cemented biconvex positive lens are both convex surfaces, the object side surface and the image side surface of the cemented biconcave negative lens are both concave surfaces, and the object side surface and the image side surface of the second cemented biconvex positive lens are both convex surfaces. The image side surface of the first cemented biconvex positive lens is cemented to the object side surface of the cemented biconcave negative lens, and the image side surface of the cemented biconcave negative lens is cemented to the object side surface of the second cemented biconvex positive lens. The optical power of the cemented lens group satisfies the following requirements: 0.04≤absolute value of optical power≤0.

08. The front lens group includes: a first lens having negative optical power, wherein the object-side surface is convex and the image-side surface is concave; a second lens having negative optical power, the object-side surface of which is convex and the image-side surface of which is concave; a third lens element having negative optical power and a concave image-side surface; a fourth lens element having negative optical power, wherein both the object-side surface and the image-side surface are concave; a fifth lens element having positive optical power, whose object-side surface is concave and whose image-side surface is convex; a sixth lens element having positive optical power and a convex object-side surface; The seventh lens is a positive meniscus lens with positive optical power, whose object side surface is concave and image side surface is convex; The rear lens is a biconvex lens with positive optical power, and both the object side and the image side are convex; The total number of lenses is 11.

2. The ultraviolet to visible wide field of view low distortion optical lens according to claim 1, characterized in that: The refractive index range of the No. 1 cemented biconvex positive lens is 1.40≤n≤1.45, and the dispersion range is 80≤ν≤95; the refractive index range of the No. 1 cemented biconcave negative lens is 1.85≤n≤1.90, and the dispersion range is 30≤ν≤45; the refractive index range of the No. 2 cemented biconvex positive lens is 1.40≤n≤1.45, and the dispersion range is 80≤ν≤95.

3. The ultraviolet to visible wide field of view low distortion optical lens according to claim 1, characterized in that: The optical power of the first lens satisfies the following conditions: 0.005 ≤ absolute value of optical power ≤ 0.01, and the clear aperture of the first lens is less than 120 mm; The optical power of the second lens satisfies the following conditions: 0.01≤absolute value of optical power≤0.03; The third lens has a flat object side and an absolute value of optical power of 0.01 ≤ ≤ 0.02; The refractive power of the fourth lens element satisfies the following conditions: 0.02 ≤ absolute value of refractive power ≤ 0.04; The refractive power of the fifth lens element satisfies the following conditions: 0.01 ≤ absolute value of refractive power ≤ 0.02; The sixth lens has a convex image-side surface and an absolute value of optical power of 0.01 ≤ ≤ 0.02; The first lens to the sixth lens are sequentially arranged from the object side to the image side along the optical axis.

4. The ultraviolet to visible wide field of view low distortion optical lens according to claim 3, characterized in that: The refractive index range of the first lens is 1.40≤n≤1.55, and the dispersion range is 70≤ν≤90; the refractive index range of the second lens is 1.60≤n≤1.70, and the dispersion range is 55≤ν≤65; the refractive index range of the third lens is 1.60≤n≤1.70, and the dispersion range is 55≤ν≤65; the refractive index range of the fourth lens is 1.65≤n≤1.80, and the dispersion range is 25≤ν≤40; the refractive index range of the fifth lens is 1.60≤n≤1.70, and the dispersion range is 40≤ν≤45; the refractive index range of the sixth lens is 1.60≤n≤1.70, and the dispersion range is 40≤ν≤45.

5. The ultraviolet to visible wide field of view low distortion optical lens according to claim 3, characterized in that: The image-side surface of the second lens and the image-side surface of the rear lens are both aspherical.

6. The ultraviolet to visible wide field of view low distortion optical lens according to claim 5, characterized in that: The aspheric surface profiles of the second lens and the rear lens satisfy the equation: Among them, z is the aspheric surface height, c is the aspheric vertex curvature, y is the aperture, k is the cone coefficient, A4 is the 4th aspheric coefficient, A6 is the 6th aspheric coefficient, A8 is the 8th aspheric coefficient, A 10 is the 10th-order aspheric coefficient.

7. The ultraviolet to visible wide field low distortion optical lens according to claim 1, characterized in that: The optical power of the seventh lens satisfies: 0.01≤absolute value of optical power≤0.04, the refractive index range of the seventh lens is 1.65≤n≤1.80, and the dispersion range is 25≤ν≤40.

8. The ultraviolet to visible wide field of view low distortion optical lens according to claim 1, characterized in that: The optical power of the rear lens satisfies: 0.05≤absolute value of optical power≤0.08, the refractive index range of the rear lens is 1.60≤n≤1.70, and the dispersion range is 55≤ν≤65.

9. The ultraviolet to visible wide field of view low distortion optical lens according to claim 1, characterized in that: The effective focal length f of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 4≤f / EPD; the back focus BFL of the optical lens and the total optical length TTL of the optical lens satisfy: 0.08≤BFL / TTL≤0.15; the relative distortion DI ST of the optical lens satisfies: DI ST≤2.5%.

10. The ultraviolet to visible wide field of view low distortion optical lens according to claim 1, characterized in that: The incident angle CRA of the chief rays of all fields of view on the image plane satisfies: CRA≤3°.

Images