Large-aperture high-pixel lens

Abstract

The utility model discloses a large-aperture high-pixel lens. A first aspheric plastic lens with negative focal power, a second aspheric plastic lens with positive focal power, a third aspheric plastic lens with positive focal power, a fourth spherical glass lens with positive focal power and a fifth spherical glass lens with positive focal power are sequentially arranged from the object side to the image side along the optical axis of the lens. The aspheric plastic sixth lens with the positive focal power, the aspheric plastic seventh lens with the negative focal power, the aspheric plastic eighth lens with the positive focal power, the fourth lens and the fifth lens are cemented lenses, and the lenses meet the conditions that F # is smaller than or equal to 1.0, f is smaller than or equal to 5.4 mm, and TTL is smaller than or equal to 30 mm. According to the utility model, two pieces of spherical glass and six pieces of aspheric plastic are mixed and combined and can be matched with 4K and 1 / 1.8 inch chips, so that the all-weather high-definition monitoring device has the advantages of high pixel and low cost, and 24-hour all-weather high-definition monitoring is realized.

Description

Technical Field

[0001] The utility model relates to the technical field of optical lenses, in particular to a large aperture high-pixel lens. Background Art

[0002] The security monitoring system uses optical fiber, coaxial cable or microwave to transmit video signals in a closed loop, and constitutes an independent and complete system from camera to image display and recording. It can reflect the monitored object in real time, vividly and truthfully, and can replace manual long-term monitoring in harsh environments and record it through security lenses. With the increasing number of information security monitoring facilities, people have an increasing demand for monitoring equipment to work at night and achieve full-color images, which requires the lens to have a larger light transmittance and higher pixels.

[0003] Existing security lenses are generally composed of 4 to 8 plastic aspherical lenses, which have at least the following shortcomings:

[0004] 1. The lens pixel is not high, the resolution from the center to the edge is very different, and the uniformity is poor;

[0005] 2. The lens has large chromatic aberration, especially at the edges, which is not conducive to edge stitching;

[0006] 3. When the lens is in high or low temperature environment or used, the temperature compensation characteristics are poor, which can easily cause defocusing, resulting in a decrease in image quality and affecting use;

[0007] 4. The image quality is poor in bad weather. Utility Model Content

[0008] Based on this, the purpose of the utility model is to provide a large aperture, high-pixel lens, which adopts a mixed combination of 2 pieces of spherical glass and 6 pieces of aspherical plastic, can be matched with 4K, 1 / 1.8-inch chip, has the advantages of high pixels and low cost, and realizes 24-hour all-weather high-definition monitoring.

[0009] The purpose of the utility model is achieved through the following technical solutions:

[0010] A large aperture high pixel lens, the surface of the lens adjacent to the object plane is the object side surface, the surface of the lens adjacent to the image plane is the image side surface, and the lens optical axis from the object side to the image side includes:

[0011] The first lens is an aspheric plastic lens with negative optical power, the object side surface is convex, and the image side surface is concave;

[0012] The second lens is an aspheric plastic lens with positive refractive power, the object side surface is concave, and the image side surface is convex;

[0013] The third lens is an aspheric plastic lens with positive refractive power, whose object side surface is convex and image side surface is concave;

[0014] Aperture diaphragm;

[0015] The fourth lens is a spherical glass lens with positive refractive power, whose object side surface is convex and image side surface is concave;

[0016] The fifth lens is a spherical glass lens with positive power, whose object side surface is convex and image side surface is convex;

[0017] The sixth lens is an aspherical plastic lens with positive refractive power, whose object side surface is convex and image side surface is convex;

[0018] The seventh lens is an aspherical plastic lens with negative optical power, whose object side surface is concave and image side surface is concave;

[0019] The eighth lens is an aspherical plastic lens with positive refractive power, whose object side surface is convex and image side surface is convex;

[0020] A filter, wherein the filter is made of H-K9L glass;

[0021] A protective glass and an image acquisition element, wherein the protective glass is integrated on the image acquisition element, and the image acquisition element is arranged on the image side of the filter.

[0022] Furthermore, the image side surface of the fourth lens and the object side surface of the fifth lens are glued to each other to form a double glued lens.

[0023] Furthermore, the lens satisfies the following conditions: F#≤1.0, f≤5.4mm, TTL≤30mm; wherein F# is the aperture of the lens, f is the total focal length of the lens, and TTL is the total optical length of the lens.

[0024] Furthermore, the lens also satisfies the following relationship: IC / TTL≥0.14, TTL / f≤5.91, OBFL / TTL≥0.15; in the relationship, f is the total focal length of the lens, TTL is the total optical length of the lens, OBFL is the optical back focus of the lens, and IC is the full image height of the 1 / 1.8-inch chip matched with the lens system.

[0025] Furthermore, the lens also satisfies the following relationship:

[0026] -1.9≤f1 / f≤-1.6,

[0027] 6.9≤f2 / f≤8.1,

[0028] 16.1≤f3 / f≤19.5,

[0029] 2.5≤f4 / f≤4.1,

[0030] 5.1≤f5 / f≤15.3,

[0031] 2.8≤f6 / f≤4.3,

[0032] -2.1≤f7 / f≤-1.7,

[0033] 1.5≤f8 / f≤2.3;

[0034] In the relationship, f is the total focal length of the lens, f1 is the focal length of the first lens, f2 is the focal length of the second lens, f3 is the focal length of the third lens, f4 is the focal length of the fourth lens, f5 is the focal length of the fifth lens, f6 is the focal length of the sixth lens, f7 is the focal length of the seventh lens, and f8 is the focal length of the eighth lens.

[0035] Furthermore, the focal length, refractive index and curvature radius of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens and the eighth lens respectively satisfy the following conditions:

[0036] f1 -11.04～-8.13 ND1 1.52～1.56 R11 +7.15～+18.32 R12 +1.91～+5.92 f2 +36.22～+42.13 ND2 1.52～1.56 R21 -6.11～-4.67 R22 -4.99～-3.87 f3 +95.54～+100.92 ND3 1.60～1.68 R31 +7.11～+8.32 R32 +5.98～+7.109 f4 +15.02～+22.32 ND4 1.70～1.91 R41 +9.98～+15.77 R42 +4.68～+7.21 f5 +18.32～+78.64 ND5 1.59～1.76 R51 +5.76～+7.56 R52 -40.66～-15.11 f6 +15.81～+18.73 ND6 1.52～1.56 R61 +8.54～+13.72 R62 -78.94～-57.67 f7 -11.05～-9.12 ND7 1.60～1.68 R71 -7.74～-5.45 R72 +97.76～+123.65 f8 +9.42～+12.76 ND8 1.52～1.56 R81 +5.01～+6.56 R82 -301.88～+550.45

[0037] Wherein, f1 is the focal length of the first lens, ND1 is the refractive index of the first lens, R11 is the radius of curvature of the object side surface of the first lens, and R12 is the radius of curvature of the image side surface of the first lens;

[0038] f2 is the focal length of the second lens, ND2 is the refractive index of the second lens, R21 is the radius of curvature of the object side surface of the second lens, and R22 is the radius of curvature of the image side surface of the second lens;

[0039] f3 is the focal length of the third lens, ND3 is the refractive index of the third lens, R31 is the radius of curvature of the object side surface of the third lens, and R32 is the radius of curvature of the image side surface of the third lens;

[0040] f4 is the focal length of the fourth lens, ND4 is the refractive index of the fourth lens, R41 is the radius of curvature of the object side surface of the fourth lens, and R42 is the radius of curvature of the image side surface of the fourth lens;

[0041] f5 is the focal length of the fifth lens, ND5 is the refractive index of the fifth lens, R51 is the radius of curvature of the object side surface of the fifth lens, and R52 is the radius of curvature of the image side surface of the fifth lens;

[0042] f6 is the focal length of the sixth lens, ND6 is the refractive index of the sixth lens, and R61 is the radius of curvature of the object side surface of the sixth lens;

[0043] f7 is the focal length of the seventh lens, ND7 is the refractive index of the seventh lens, R71 is the radius of curvature of the object side surface of the seventh lens, and R72 is the radius of curvature of the image side surface of the seventh lens;

[0044] f8 is the focal length of the eighth lens, ND8 is the refractive index of the eighth lens, R81 is the radius of curvature of the object side surface of the eighth lens, and R82 is the radius of curvature of the image side surface of the eighth lens;

[0045] Focal length: The "+" sign indicates that the lens has positive focal length, and the "-" sign indicates that the lens has negative focal length. The unit is mm.

[0046] Radius of curvature: The "+" sign indicates that the surface is bent toward the image plane, and the "-" sign indicates that the surface is bent toward the object plane. The unit is mm.

[0047] Furthermore, the aspheric surfaces of the first lens, the second lens, the third lens, the sixth lens, the seventh lens and the eighth lens satisfy the following formula:

[0048]

[0049] Wherein, Z is the vector height of the lens along the optical axis, k is the quadratic cone coefficient, γ is the lens height, c is the lens curvature, A, B, C, D, E, F, G are the 4th, 6th, 8th, 10th, 12th, 14th, and 16th order coefficients of the aspheric polynomial.

[0050] The beneficial effects of the utility model are:

[0051] The utility model has a large aperture and high pixel lens, which adopts a mixed combination of 2 pieces of spherical glass and 6 pieces of aspherical plastic. The total focal length of the optical lens is f≤5.4mm, and the aperture F# satisfies F#≤1.0. When the aperture value is small, the light aperture is relatively large, which can ensure a large amount of light entering the system. By matching the appropriate module, full-color monitoring images can be captured under extremely low light conditions.

[0052] The utility model has reasonable lens material selection, optical power distribution and optical design optimization, so that the optical system aberration is well corrected, the optical performance is good, and it can match 4K and 1 / 1.8-inch chips to achieve 24-hour all-weather high-definition monitoring.

[0053] In terms of manufacturability, the lenses of the utility model are insensitive, the lens surface is simple and easy to manufacture, and under the same performance, its processing cost is relatively low compared to the market, it has a high cost performance, and can achieve the characteristics of small size, light weight, good performance and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 This is a schematic diagram of the optical structure of Example 1 of the utility model;

[0055] Figure 2 This is a schematic diagram of the optical path structure of Example 1 of the utility model;

[0056] Figure 3 This is the field curvature and distortion diagram of visible light 0.546μm in Example 1 of the utility model;

[0057] Figure 4 This is the FFT MTF curve of visible light 0.435-0.656μm of Example 1 of the utility model;

[0058] Figure 5 This is a schematic diagram of the optical structure of Example 2 of the utility model;

[0059] Figure 6 This is a schematic diagram of the optical path structure of Example 2 of the utility model;

[0060] Figure 7 This is the field curvature and distortion diagram of visible light 0.546μm in Example 2 of the utility model;

[0061] Figure 8 This is the FFT MTF curve of visible light 0.435-0.656μm of Example 2 of the utility model;

[0062] Figure numerals: 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, filter; 10, protective glass; 11, image acquisition element; 12, aperture stop. DETAILED DESCRIPTION

[0063] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. In this specification, the expressions first, second, third, etc. are only used to distinguish one feature from another feature, and do not represent any limitation on the features. The shape of the spherical or aspherical surface is not limited to the shape of the spherical or aspherical surface shown in the drawings. The drawings are only examples and are not drawn strictly to scale.

[0064] In the present invention, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the position of the convex surface is not defined, it means that the lens surface is convex at least in the paraxial region; if the lens surface is concave and the position of the concave surface is not defined, it means that the lens surface is concave at least in the paraxial region; if the lens surface is not limited to convex, concave or flat, it means that the lens surface can be convex, concave or flat. The surface of each lens closest to the object is called the object side of the lens, and the surface of each lens closest to the imaging surface is called the image side of the lens.

[0065] Unless otherwise defined, all terms (including technical terms and scientific terms) used in the present invention have the same meaning as commonly understood by ordinary technicians in the field to which the present application belongs. It should also be understood that terms (such as terms defined in commonly used dictionaries) should be interpreted as having the same meaning as their meaning in the context of the relevant technology, and will not be interpreted in an idealized or overly formal sense unless explicitly defined in the present invention.

[0066] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model. In order to better understand and implement, the utility model is described in detail below with reference to the accompanying drawings.

[0067] The utility model provides a large aperture high pixel lens, the surface of the lens adjacent to the object plane is the object side surface, the surface of the lens adjacent to the image plane is the image side surface, and the first lens 1, the second lens 2, the third lens 3, the aperture stop 12, the fourth lens 4, the fifth lens 5, the sixth lens 6, the seventh lens 7, the eighth lens 8, the filter 9, the protective glass 10 and the image acquisition element 11 are sequentially arranged along the optical axis of the lens from the object side to the image side. Among them, the aperture stop 12 is arranged between the third lens 3 and the fourth lens 4; the filter 9 is arranged on the image side surface of the eighth lens 8, and the filter 9 is made of H-K9L glass; the protective glass 10 is integrated on the image acquisition element 11, and the image acquisition element 11 is arranged on the image side surface of the filter 9.

[0068] In the present invention, in order to make the optical system present better performance, we should reasonably select lens materials, reasonably allocate the focal length of each lens and reasonably optimize the optical system during the design process, so as to finally optimize the performance of the optical system. Usually, the existence of aberrations in the optical system will affect the imaging quality of the optical system. Correcting aberrations is the key to optimizing the optical system. There are many ways to correct aberrations. For example, selecting lenses with different refractive indices and large differences in Abbe numbers for use can eliminate chromatic aberration and spherical aberration to a certain extent. Reasonable allocation and optimization of the focal length and shape of each lens can also correct the aberrations of the system.

[0069] In the present invention, f is the total focal length of the lens, f1 is the focal length of the first lens 1, f2 is the focal length of the second lens 2, f3 is the focal length of the third lens 3, f4 is the focal length of the fourth lens 4, f5 is the focal length of the fifth lens 5, f6 is the focal length of the sixth lens 6, f7 is the focal length of the seventh lens 7, f8 is the focal length of the eighth lens 8, the total focal length of the entire lens is f, and the ratio of the focal length of each lens to the total focal length of the lens satisfies the following conditions:

[0070] -1.9≤f1 / f≤-1.6,

[0071] 6.9≤f2 / f≤8.1,

[0072] 16.1≤f3 / f≤19.5,

[0073] 2.5≤f4 / f≤4.1,

[0074] 5.1≤f5 / f≤15.3,

[0075] 2.8≤f6 / f≤4.3,

[0076] -2.1≤f7 / f≤-1.7,

[0077] 1.5≤f8 / f≤2.3.

[0078] In the present invention, considering the aberration of the optical system and the problem of balanced temperature drift, the focal length, refractive index and curvature radius of each lens respectively meet the following conditions:

[0079] f1 -11.04～-8.13 ND1 1.52～1.56 R11 +7.15～+18.32 R12 +1.91～+5.92 f2 +36.22～+42.13 ND2 1.52～1.56 R21 -6.11～-4.67 R22 -4.99～-3.87 f3 +95.54～+100.92 ND3 1.60～1.68 R31 +7.11～+8.32 R32 +5.98～+7.109 f4 +15.02～+22.32 ND4 1.70～1.91 R41 +9.98～+15.77 R42 +4.68～+7.21 f5 +18.32～+78.64 ND5 1.59～1.76 R51 +5.76～+7.56 R52 -40.66～-15.11 f6 +15.81～+18.73 ND6 1.52～1.56 R61 +8.54～+13.72 R62 -78.94～-57.67 f7 -11.05～-9.12 ND7 1.60～1.68 R71 -7.74～-5.45 R72 +97.76～+123.65 f8 +9.42～+12.76 ND8 1.52～1.56 R81 +5.01～+6.56 R82 -301.88～+550.45

[0080] Wherein, f1 is the focal length of the first lens 1, ND1 is the refractive index of the first lens 1, R11 is the curvature radius of the object side surface of the first lens 1, and R12 is the curvature radius of the image side surface of the first lens 1;

[0081] f2 is the focal length of the second lens 2, ND2 is the refractive index of the second lens 2, R21 is the curvature radius of the object side surface of the second lens 2, and R22 is the curvature radius of the image side surface of the second lens 2;

[0082] f3 is the focal length of the third lens 3, ND3 is the refractive index of the third lens 3, R31 is the curvature radius of the object side surface of the third lens 3, and R32 is the curvature radius of the image side surface of the third lens 3;

[0083] f4 is the focal length of the fourth lens 4, ND4 is the refractive index of the fourth lens 4, R41 is the curvature radius of the object side surface of the fourth lens 4, and R42 is the curvature radius of the image side surface of the fourth lens 4;

[0084] f5 is the focal length of the fifth lens 5, ND5 is the refractive index of the fifth lens 5, R51 is the radius of curvature of the object side surface of the fifth lens 5, and R52 is the radius of curvature of the image side surface of the fifth lens 5;

[0085] f6 is the focal length of the sixth lens 6, ND6 is the refractive index of the sixth lens 6, and R61 is the radius of curvature of the object side surface of the sixth lens 6;

[0086] f7 is the focal length of the seventh lens 7 , ND7 is the refractive index of the seventh lens 7 , R71 is the radius of curvature of the object side surface of the seventh lens 7 , and R72 is the radius of curvature of the image side surface of the seventh lens 7 ;

[0087] f8 is the focal length of the eighth lens 8, ND8 is the refractive index of the eighth lens 8, R81 is the radius of curvature of the object side surface of the eighth lens 8, and R82 is the radius of curvature of the image side surface of the eighth lens 8;

[0088] Focal length: The "+" sign indicates that the lens has positive focal length, and the "-" sign indicates that the lens has negative focal length. The unit is mm.

[0089] Radius of curvature: The "+" sign indicates that the surface is bent toward the image plane, and the "-" sign indicates that the surface is bent toward the object plane. The unit is mm.

[0090] In the present invention, F# is the aperture of the lens, f is the total focal length of the lens; TTL is the total optical length of the lens; OBFL is the optical back focus of the lens, which is the distance from the point on the image side of the eighth lens 8 closest to the image plane to the image plane; IC is the total image height of the 1 / 1.8 inch chip matched with the lens system; they meet the following conditions:

[0091] F#≤1.0,

[0092] f≤5.4mm,

[0093] TTL≤30mm;

[0094] IC / TTL ≥ 0.14,

[0095] TTL / f≤5.91,

[0096] OBFL / TTL≥0.15.

[0097] In the present invention, the aspheric surfaces of the first lens 1, the second lens 2, the third lens 3, the sixth lens 6, the seventh lens 7 and the eighth lens 8 can be defined by the following equation of an even-order aspheric surface:

[0098]

[0099] Wherein, Z is the vector height of the lens along the optical axis, k is the quadratic cone coefficient, γ is the lens height, c is the lens curvature, A, B, C, D, E, F, G are the 4th, 6th, 8th, 10th, 12th, 14th, and 16th order coefficients of the aspheric polynomial.

[0100] The following is a specific implementation scheme based on the above-mentioned configuration of the present invention and a specific description of the large aperture high pixel lens according to the present invention. The specific implementation scheme data is summarized in the following Table 1:

[0101] Table 1

[0102] Example 1 Example 2 -1.9≤f1 / f≤-1.6 -1.7 -1.9 6.9≤f2 / f≤8.1 7.8 7.5 16.1≤f3 / f≤19.5 19.2 18.1 2.5≤f4 / f≤4.1 2.7 3.8 5.1≤f5 / f≤15.3 14.8 5.5 2.8≤f6 / f≤4.3 3.3 3.0 -2.1≤f7 / f≤-1.7 -1.8 -2.0 1.5≤f8 / f≤2.3 1.9 2.2 IC / TTL≥0.14 0.14 0.15 TTL / f≤5.91 5.66 5.6 OBFL / TTL≥0.15 0.15 0.15 f≤5.4mm 5.3 5.4 TTL≤30mm 30 30 OBFL 4.5 4.5 F#≤1.0 1 1

[0103] Example 1

[0104] refer to Figure 1 , Figure 2 As shown, they are respectively a schematic diagram of the optical structure and a schematic diagram of the optical path structure of this embodiment 1.

[0105] In this embodiment, the field of view angle FOV=114°, and the chief ray angle of the lens is defined as CRA, which satisfies CRA≤8°. By reasonably selecting lens materials, reasonably allocating the focal length and optical power of each lens, and optimizing the optical system, the thickness of each lens is uniform and insensitive, which is easy to mass-produce.

[0106] The lenses in this embodiment are arranged in order from the object side to the image side along the lens optical axis:

[0107] The first lens 1 is an aspheric plastic lens with negative optical power, the object side of which is convex and presents a "W" shape, and the image side is concave;

[0108] The second lens 2 is an aspheric plastic lens with positive refractive power, the object side surface is concave, and the image side surface is convex;

[0109] The third lens 3 is an aspherical plastic lens with positive refractive power, whose object side surface is convex and image side surface is concave;

[0110] Aperture stop 12;

[0111] The fourth lens 4 is a spherical glass lens with positive refractive power, whose object side surface is convex and image side surface is concave;

[0112] The fifth lens 5 is a spherical glass lens with positive refractive power, whose object side surface is convex and image side surface is convex;

[0113] The sixth lens 6 is an aspherical plastic lens with positive refractive power, whose object side surface is convex and image side surface is convex;

[0114] The seventh lens 7 is an aspherical plastic lens with negative optical power, whose object side surface is concave and image side surface is concave;

[0115] The eighth lens 8 is an aspherical plastic lens with positive refractive power, whose object side surface is convex and image side surface is convex;

[0116] Filter 9,

[0117] A protective glass 10 and an image acquisition element 11, wherein the protective glass 10 is integrated on the image acquisition element 11;

[0118] The image side surface of the fourth lens 4 and the object side surface of the fifth lens 5 are glued together to form a double glued lens.

[0119] In this embodiment, the first lens 1 is an aspheric plastic lens with negative optical power, whose object side surface is convex and whose image side surface is concave, i.e., a meniscus-shaped lens with positive optical power, which is convenient for quickly converging light; the second lens 2 is an aspheric plastic lens with positive optical power, whose main function is to expand the beam and ensure that the lens has a larger aperture; the third lens 3 is a high-refractive-index plastic aspheric lens with a refractive index greater than 1.6 and an Abbe number less than 24, and the fourth lens 4 and the fifth lens 5 are glass spherical cemented lenses with a double-convex structure glued together, whose main function is to correct chromatic aberration and ensure that the lens has high and low temperature resistance; the object side surface of the sixth lens 6 is convex and its image side surface is convex, and the object side surface of the seventh lens 7 is concave and its image side surface is concave, whose main function is to further improve the resolution of the lens; the object side surface of the eighth lens 8 is convex and its image side surface is convex, whose main function is to correct the CRA and larger image height of the lens so that it can match a 1 / 1.8-inch chip.

[0120] Taking into account the aberration of the optical system and the problem of balanced temperature drift, the curvature radius, center thickness, refractive index, Abbe constant and aspheric K value of each lens are designed as shown in Table 2.

[0121] Table 2 gives the radius of curvature R (unit: mm) of each lens, the center thickness d (unit: mm) of each lens, the refractive index (ND) of each lens, the Abbe constant (VD) and the aspheric K value (Conic) of each lens.

[0122] Table 2

[0123]

[0124]

[0125] In Table 2, the radius of curvature R represents the degree of curvature of the lens surface, a positive value represents that the surface is bent toward the image side, and a negative value represents that the surface is bent toward the object side, wherein "INFINITY" represents that the surface is a plane; the center thickness D represents the center axial distance from the current surface to the next surface, the refractive index ND represents the light deflection ability of the current lens material, and the Abbe number VD represents the dispersion characteristics of the current lens material to the light; the k value represents the numerical value of the best fitting cone coefficient of the aspheric surface, 11 represents the object side surface of the first lens 1, 12 represents the image side surface of the first lens 1, and so on.

[0126] In this embodiment, the aspheric surfaces of the first lens 1 , the second lens 2 , the third lens 3 , the sixth lens 6 , the seventh lens 7 and the eighth lens 8 can all be defined by the above-mentioned equation of the even-order aspheric surface.

[0127] Table 3 gives various coefficients of the aspherical surfaces of each optical surface of the first lens 1, the second lens 2, the third lens 3, the sixth lens 6, the seventh lens 7 and the eighth lens 8.

[0128] Table 3

[0129] Surface number A B C D E F G H I 11 -2.1E-03 5.6E-05 -6.6E-07 -1.7E-09 1.3E-10 -1.0E-12 0.0E+00 0 0 12 -6.6E-04 1.0E-04 -1.8E-05 2.5E-06 -1.9E-07 7.1E-09 -1.1E-10 0 0 21 2.4E-03 -1.4E-04 4.4E-06 -2.4E-08 -7.3E-10 -1.2E-10 6.3E-12 0 0 22 2.3E-03 -1.0E-04 8.6E-06 -6.2E-07 3.6E-08 -1.2E-09 1.7E-11 0 0 31 2.8E-04 -1.3E-05 1.5E-06 -7.5E-08 1.9E-09 -1.9E-11 0.0E+00 0 0 32 -9.9E-04 1.2E-04 -8.9E-06 4.6E-07 -1.3E-08 1.7E-10 0.0E+00 0 0 61 -7.0E-04 -4.7E-05 2.7E-06 -4.8E-08 -3.7E-09 2.4E-10 0.0E+00 0 0 62 -2.9E-03 -7.8E-05 1.6E-05 -3.2E-07 -2.5E-08 9.9E-10 0.0E+00 0 0 71 3.0E-04 -6.2E-05 -8.3E-06 1.9E-06 -1.1E-07 2.1E-09 0.0E+00 0 0 72 2.6E-03 -1.6E-04 1.9E-05 -2.6E-06 2.4E-07 -1.2E-08 2.1E-10 0 0 81 -4.5E-03 4.3E-04 -3.8E-05 2.5E-06 -8.2E-08 1.0E-09 0.0E+00 0 0 82 -1.2E-03 -5.9E-05 8.4E-06 -7.4E-07 4.3E-08 -1.3E-09 1.4E-11 0 0

[0130] In this embodiment 1, the total focal length of the lens system is f=5.3 mm, the aperture value F#=1.0, the total optical length TTL of the lens is 30 mm, the optical back focus OBFL of the lens is 4.5 mm, and the lens matches a 1 / 1.8-inch chip.

[0131] refer to Figure 3 As shown in FIG. 1 , the field curvature curve and distortion curve of the lens of the embodiment of the visible light of 0.546 μm are shown, wherein the vertical coordinate ASTIGMATIC FIELD CURVES in the field curvature curve represents different fields of view, and the horizontal coordinate FOCUS (MILLIMETERS) represents the field area (mm); Figure 3 It can be seen that the field curvature offset in the meridian and sagittal directions on the image plane is controlled within ±0.05mm, indicating that the field curvature of the lens is well corrected. In the distortion curve, the horizontal axis represents F-tan (Theta) distortion (unit: %), and the vertical axis represents the half-image height value (unit: mm). It can be seen from the figure that within the full field of view of the lens, the distortion is controlled within -40%, indicating that the distortion is well corrected.

[0132] refer to Figure 4The figure shows the MTF vs Frequency curve of the lens in the embodiment under the visible light of 0.435-0.656μm. The horizontal axis represents the frequency (unit: lp / mm), the horizontal axis is wide from 0lp / mm to 200lp / mm, and the vertical axis represents the MTF value. Figure 4 It can be seen that at a spatial frequency of 200lp / mm, the MTF value of the lens within a 114° field of view matching a 1 / 1.8-inch chip is above 0.3, indicating that the lens has a high resolution. The MTF performance of the lens in the visible light field of 0.435-0.656μm is good.

[0133] Depend on Figure 3 , 4 It can be seen that the field curvature, distortion and MTF of the lens in this embodiment can be well corrected.

[0134] Example 2

[0135] refer to Figure 5 , Figure 6 As shown, they are respectively a schematic diagram of the optical structure and a schematic diagram of the optical path structure of this embodiment 2.

[0136] In this embodiment, the field of view angle FOV=107°, and the chief ray angle of the lens is defined as CRA, which satisfies CRA≤11°. By reasonably selecting lens materials, reasonably allocating the focal length and optical power of each lens, and optimizing the optical system, the thickness of each lens is uniform and insensitive, which is easy to mass-produce.

[0137] The lenses in this embodiment are arranged in order from the object side to the image side along the lens optical axis:

[0138] The first lens 1 is an aspherical plastic lens with negative optical power, whose object side surface is convex and image side surface is concave;

[0139] The second lens 2 is an aspheric plastic lens with positive refractive power, the object side surface is concave, and the image side surface is convex;

[0140] The third lens 3 is an aspherical plastic lens with positive refractive power, whose object side surface is convex and image side surface is concave;

[0141] Aperture stop 12;

[0142] The fourth lens 4 is a spherical glass lens with positive refractive power, whose object side surface is convex and image side surface is concave;

[0143] The fifth lens 5 is a spherical glass lens with positive refractive power, whose object side surface is convex and image side surface is convex;

[0144] The sixth lens 6 is an aspherical plastic lens with positive refractive power, whose object side surface is convex and image side surface is convex;

[0145] The seventh lens 7 is an aspherical plastic lens with negative optical power, whose object side surface is concave and image side surface is concave;

[0146] The eighth lens 8 is an aspherical plastic lens with positive refractive power, whose object side surface is convex and image side surface is convex;

[0147] Filter 9,

[0148] A protective glass 10 and an image acquisition element 11, wherein the protective glass 10 is integrated on the image acquisition element 11;

[0149] The image side surface of the fourth lens 4 and the object side surface of the fifth lens 5 are glued together to form a double glued lens.

[0150] In this embodiment, the first lens 1 is an aspheric plastic lens with negative power, whose object side surface is convex and whose image side surface is concave, i.e., a meniscus-shaped lens with positive power, which is convenient for quickly converging light; the second lens 2 is an aspheric plastic lens with positive power, which is mainly used for beam expansion to ensure that the lens has a larger aperture; the third lens 3 is a high-refractive-index plastic aspheric lens with a refractive index greater than 1.6 and an Abbe number less than 24, and the fourth lens 4 and the fifth lens 5 are glass spherical cemented lenses with a double-convex structure glued together, which are mainly used to correct chromatic aberration and ensure that the lens has a high resistance to high and low temperature performance; the object side surface of the sixth lens 6 is convex and its image side surface is convex, and the object side surface of the seventh lens 7 is concave and its image side surface is concave, which is mainly used to further improve the resolution of the lens; the object side surface of the eighth lens 8 is convex and its image side surface is convex, which is mainly used to correct the CRA and large image height of the lens so that it can match a 1 / 1.8-inch chip.

[0151] Table 4 gives the radius of curvature R (unit: mm) of each lens, the center thickness d (unit: mm) of each lens, the refractive index (ND) of each lens, the Abbe constant (VD) and the aspheric K value (Conic) of each lens.

[0152] Table 4

[0153] Surface number Curvature radius R Center thickness D Refractive index ND Abbe constant VD Object INFINITY INFINITY 11 7.403 1.800 1.537 55.711 12 2.857 3.900 21 -5.093 3.000 1.537 55.711 22 -4.977 0.100 31 7.294 2.884 1.641 23.917 32 6.987 1.405 Stop INFINITY 0.100 1.805 25.477 41 13.969 1.272 1.755 52.337 51 6.091 3.764 52 -17.978 0.100 61 10.761 1.272 1.537 55.711 62 -72.558 3.764 71 -6.952 0.100 1.641 23.917 72 119.112 2.081 81 5.757 0.304 1.537 55.711 82 137.499 0.100 91 INFINITY 0.210 1.517 64.212 92 INFINITY 3.671 101 INFINITY 0.400 1.517 64.212 102 INFINITY 0.509 111 INFINITY

[0154] In Table 4, the radius of curvature R represents the degree of curvature of the lens surface, a positive value represents that the surface is bent toward the image side, and a negative value represents that the surface is bent toward the object side, wherein "INFINITY" represents that the surface is a plane; the center thickness D represents the center axial distance from the current surface to the next surface, the refractive index ND represents the light deflection ability of the current lens material, and the Abbe number VD represents the dispersion characteristics of the current lens material to the light; the k value represents the numerical value of the best fitting cone coefficient of the aspheric surface, 11 represents the object side surface of the first lens 1, 12 represents the image surface of the first lens 1, and so on.

[0155] In this embodiment, the aspheric surfaces of the first lens 1 , the second lens 2 , the third lens 3 , the sixth lens 6 , the seventh lens 7 and the eighth lens 8 can all be defined by the above-mentioned equation of the even-order aspheric surface.

[0156] Table 5 gives various coefficients of the aspherical surfaces of each optical surface of the first lens 1, the second lens 2, the third lens 3, the sixth lens 6, the seventh lens 7 and the eighth lens 8.

[0157] Table 5

[0158] Surface number A B C D E F G H I 11 -2.3E-03 5.6E-05 -6.1E-07 -1.7E-09 1.2E-10 -8.7E-13 0.0E+00 0 0 12 -1.6E-04 1.2E-04 -1.9E-05 2.6E-06 -1.9E-07 7.1E-09 -1.1E-10 0 0 21 2.4E-03 -1.3E-04 4.5E-06 -5.0E-08 -7.3E-10 -1.2E-10 6.3E-12 0 0 22 2.3E-03 -1.0E-04 8.7E-06 -6.3E-07 3.6E-08 -1.2E-09 1.7E-11 0 0 31 2.7E-04 -1.3E-05 1.5E-06 -7.3E-08 2.0E-09 -1.9E-11 0.0E+00 0 0 32 -9.9E-04 1.2E-04 -8.9E-06 4.6E-07 -1.3E-08 1.7E-10 0.0E+00 0 0 61 -5.9E-04 -5.0E-05 2.4E-06 -3.0E-08 -3.7E-09 2.4E-10 0.0E+00 0 0 62 -2.8E-03 -7.6E-05 1.6E-05 -3.2E-07 -2.5E-08 9.9E-10 0.0E+00 0 0 71 2.9E-04 -6.1E-05 -8.0E-06 1.8E-06 -1.1E-07 2.1E-09 0.0E+00 0 0 72 2.5E-03 -1.7E-04 1.9E-05 -2.5E-06 2.4E-07 -1.2E-08 2.1E-10 0 0 81 -4.6E-03 4.3E-04 -3.8E-05 2.5E-06 -8.2E-08 1.0E-09 0.0E+00 0 0 82 -1.2E-03 -5.9E-05 8.4E-06 -7.4E-07 4.3E-08 -1.3E-09 1.4E-11 0 0

[0159] In this embodiment 2, the total focal length of the lens system is f=5.4 mm, the aperture value F#=1.0, the total optical length TTL of the lens is 30 mm, the optical back focus OBFL of the lens is 4.5 mm, and the lens matches a 1 / 1.8-inch chip.

[0160] refer to Figure 7 As shown in FIG. 1 , the field curvature curve and distortion curve of the lens of the embodiment of the visible light of 0.546 μm are shown, wherein the vertical coordinate ASTIGMATIC FIELD CURVES in the field curvature curve represents different fields of view, and the horizontal coordinate FOCUS (MILLIMETERS) represents the field area (mm); Figure 3 It can be seen that the field curvature offset in the meridian and sagittal directions on the image plane is controlled within ±0.02mm, indicating that the field curvature of the lens is well corrected. In the distortion curve, the horizontal axis represents F-tan (Theta) distortion (unit: %), and the vertical axis represents the half-image height value (unit: mm). From the figure, it can be seen that the distortion within the full field of view of the lens is within -45%, indicating that the distortion is well corrected.

[0161] refer to Figure 8 The figure shows the MTF vs Frequency curve of the lens in the visible light range of 0.435-0.656 μm in this embodiment. The horizontal axis represents the spatial frequency (unit: lp / mm), the horizontal axis ranges from 0lp / mm to 200lp / mm, and the vertical axis represents the MTF value. Figure 8It can be seen that at a spatial frequency of 200lp / mm, the MTF value of the lens within a 107° field of view matching a 1 / 1.8-inch chip is above 0.3, indicating that the lens has a high resolution. The MTF performance of the lens in the visible light field of 0.435-0.656μm is good.

[0162] Depend on Figure 7 , 8 It can be seen that the field curvature, distortion and MTF of the lens in this embodiment can be well corrected.

[0163] The above only expresses the preferred technical solution of the utility model, and its description is relatively specific and detailed, but it cannot be understood as limiting the scope of the utility model patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the utility model, and the utility model is also intended to include these modifications and modifications.

Claims

1. A large aperture high pixel lens, characterized by: Set along the lens optical axis from the object side to the image side in order: The first lens is an aspheric plastic lens with negative optical power, the object side surface is convex, and the image side surface is concave; The second lens is an aspheric plastic lens with positive refractive power, the object side surface is concave, and the image side surface is convex; The third lens is an aspheric plastic lens with positive refractive power, whose object side surface is convex and image side surface is concave; Aperture diaphragm; The fourth lens is a spherical glass lens with positive refractive power, whose object side surface is convex and image side surface is concave; The fifth lens is a spherical glass lens with positive power, whose object side surface is convex and image side surface is convex; The sixth lens is an aspherical plastic lens with positive refractive power, whose object side surface is convex and image side surface is convex; The seventh lens is an aspherical plastic lens with negative optical power, whose object side surface is concave and image side surface is concave; The eighth lens is an aspherical plastic lens with positive refractive power, whose object side surface is convex and image side surface is convex; Optical filters; A protective glass and an image acquisition element, wherein the protective glass is integrated on the image acquisition element, and the image acquisition element is arranged on the image side of the filter.

2. The large aperture high pixel lens according to claim 1, characterized in that: The lens meets the following conditions: F#≤1.0， f≤5.4mm, TTL≤30mm; Among them, F# is the aperture of the lens, f is the total focal length of the lens, and TTL is the total optical length of the lens.

3. The large aperture high pixel lens according to claim 1, characterized in that: The lens also satisfies the following relationship: IC / TTL ≥ 0.14, TTL / f≤5.91, OBFL / TTL ≥ 0.15; In the relationship, f is the total focal length of the lens, TTL is the total optical length of the lens, OBFL is the optical back focus of the lens, and IC is the full image height of the 1 / 1.8-inch chip used in the lens system.

4. The large aperture high pixel lens according to claim 1, characterized in that: The lens also satisfies the following relationship: -1.9≤f1 / f≤-1.6, 6.9≤f2 / f≤8.1, 16.1≤f3 / f≤19.5, 2.5≤f4 / f≤4.1, 5.1≤f5 / f≤15.3, 2.8≤f6 / f≤4.3, -2.1≤f7 / f≤-1.7, 1.5≤f8 / f≤2.3; In the relationship, f is the total focal length of the lens, f1 is the focal length of the first lens, f2 is the focal length of the second lens, f3 is the focal length of the third lens, f4 is the focal length of the fourth lens, f5 is the focal length of the fifth lens, f6 is the focal length of the sixth lens, f7 is the focal length of the seventh lens, and f8 is the focal length of the eighth lens.

5. The large aperture high pixel lens according to claim 1, characterized in that: The focal length ranges corresponding to the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens and the eighth lens are respectively -11.04 to -8.13, +36.22 to +42.13, +95.54 to +100.92, +15.02 to +22.32, +18.32 to +78.64, +15.81 to +18.73, -11.05 to -9.12, and +9.42 to +12.76; wherein the "+" sign indicates that the lens has a positive focal power, and the "-" sign indicates that the lens has a negative focal power, and the unit of the focal length is mm.

6. The large aperture high pixel lens according to claim 1, characterized in that: The refractive index ranges corresponding to the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens and the eighth lens are 1.52-1.56, 1.52-1.56, 1.60-1.68, 1.70-1.91, 1.59-1.76, 1.52-1.56, 1.60-1.68 and 1.52-1.56 respectively.

7. The large aperture high pixel lens according to claim 1, characterized in that: The object side surface curvature radii corresponding to the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens and the eighth lens are respectively in the range of +7.15 to +18.32, -6.11 to -4.67, +7.11 to +8.32, +9.98 to +15.77, +5.76 to +7.56, +8.54 to +13.72, -7.74 to -5.45, and +5.01 to +6.56; wherein the "+" sign indicates that the surface is bent toward the image side, and the "-" sign indicates that the surface is bent toward the object side, and the unit of the curvature radius is mm.

8. The large aperture high pixel lens according to claim 1, characterized in that: The image side surface curvature radii corresponding to the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens and the eighth lens are respectively in the range of +1.91 to +5.92, -4.99 to -3.87, +5.98 to +7.109, +4.68 to +7.21, -40.66 to -15.11, -78.94 to -57.67, +97.76 to +123.65, and -301.88 to +550.45; wherein the "+" sign indicates that the surface is bent toward the image side, and the "-" sign indicates that the surface is bent toward the object side, and the unit of the curvature radius is mm.

9. The large aperture high pixel lens according to claim 1, characterized in that: The image side surface of the fourth lens and the object side surface of the fifth lens are glued together to form a double glued lens; The filter is made of H-K9L glass.

10. The large aperture high pixel lens according to claim 1, characterized in that: The aspheric surfaces of the first lens, the second lens, the third lens, the sixth lens, the seventh lens and the eighth lens satisfy the following formula: Wherein, Z is the vector height of the lens along the optical axis, k is the quadratic cone coefficient, γ is the lens height, c is the lens curvature, A, B, C, D, E, F, G are the 4th, 6th, 8th, 10th, 12th, 14th, and 16th order coefficients of the aspheric polynomial.

Images