CN115903184A - optical imaging system - Google Patents

Abstract

The present invention provides an optical imaging system, which includes sequentially from the object side to the image side of the optical imaging system: a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens Lens; the radius of curvature R13 on the object side of the seventh lens and the radius of curvature R14 on the image side of the seventh lens satisfy: 0<R14/R13<10; The distance TTL on the optical axis of the imaging system and half ImgH of the diagonal length of the effective pixel area on the imaging surface meet: TTL/ImgH<1.3; the effective focal length f7 of the seventh lens, the radius of curvature of the object side of the seventh lens Satisfy between R13: 2.0<f7/R13<2.5; between the dispersion coefficient V6 of the sixth lens, the dispersion coefficient V7 of the seventh lens, the effective focal length f6 of the sixth lens, and the effective focal length f7 of the seventh lens: 7.5<(V6+V7)/2/(f6‑f7)<9.0. The invention solves at least one of the problems of large volume, poor imaging quality and poor matching with chips in the prior art.

Description

Optical imaging system

Technical Field

The present invention relates to the technical field of optical imaging equipment, and in particular to an optical imaging system.

Background Art

With the development of science and technology, users have higher and higher requirements for smartphones. In order to obtain a better hand feel, mobile phones are developing in the direction of being lighter and thinner. However, due to the high requirements of users for camera functions, the optical imaging system on the mobile phone usually uses a large number of lenses to obtain the characteristics of large image surface and high image quality, which makes the optical imaging system larger and difficult to match with thin and light mobile phones. At the same time, a large number of lenses also brings more difficulties to the correction of aberrations. In addition, with the development of semiconductor technology and the rapid development of the chip industry, it is more difficult to match the main light angle of the optical imaging system with the main light angle of the chip, resulting in difficulty in ensuring the imaging quality.

That is to say, the optical imaging system in the prior art has at least one of the following problems: large size, poor imaging quality, and poor compatibility with the chip.

Summary of the invention

The main purpose of the present invention is to provide an optical imaging system to solve at least one of the problems of the optical imaging system in the prior art, namely, large size, poor imaging quality, and poor compatibility with a chip.

To achieve the above-mentioned purpose, according to one aspect of the present invention, an optical imaging system is provided, which has only seven lenses, and includes, from the object side to the image side of the optical imaging system: a first lens, the focal length of the first lens is positive; a second lens, the focal length of the second lens is negative; a third lens, the focal length of the third lens is negative; a fourth lens, the focal length of the fourth lens is positive; a fifth lens, the focal length of the fifth lens is negative; a sixth lens, the focal length of the sixth lens is positive; a seventh lens, the focal length of the seventh lens is negative, the curvature radius of the object side surface of the seventh lens and the curvature radius of the image side surface of the seventh lens are less than zero; the curvature radius of the object side surface of the seventh lens and the curvature radius of the image side surface of the seventh lens are R13 and R14, respectively. The radius of curvature R14 satisfies: 0<R14/R13<10; the distance TTL from the object side surface of the first lens to the imaging surface of the optical imaging system on the optical axis of the optical imaging system and half the diagonal length of the effective pixel area on the imaging surface ImgH satisfy: TTL/ImgH<1.3; the effective focal length f7 of the seventh lens and the radius of curvature R13 of the object side surface of the seventh lens satisfy: 2.0<f7/R13<2.5; the dispersion coefficient V6 of the sixth lens, the dispersion coefficient V7 of the seventh lens, the effective focal length f6 of the sixth lens and the effective focal length f7 of the seventh lens satisfy: 7.5<(V6+V7)/2/(f6-f7)<9.0.

Furthermore, the effective focal length f of the optical imaging system and the maximum field of view FOV of the optical imaging system satisfy: f*tan(FOV/2)>4.5.

Furthermore, the effective focal length f1 of the first lens, the maximum effective radius DT11 of the object side surface of the first lens, the maximum effective radius DT12 of the image side surface of the first lens, the effective focal length f2 of the second lens, the maximum effective radius DT21 of the object side surface of the second lens, and the maximum effective radius DT22 of the image side surface of the second lens satisfy the following: -5.0<f1/(DT11+DT12)+f2/(DT21+DT22)<-2.0.

Further, the air interval T67 between the sixth lens and the seventh lens on the optical axis satisfies: T67>Tij, wherein Tij is the air interval between the i-th lens to the j-th lens on the optical axis, i is 1, 2, 3, 4, 5, j=i+1, and the air interval T67 between the sixth lens and the seventh lens on the optical axis and the sum of the air intervals ∑AT between lenses of two adjacent optical imaging systems on the optical axis satisfy: T67/∑AT<0.5.

Further, a radius of curvature R11 of the object side surface of the sixth lens is less than 1.5, a radius of curvature of the object side surface of the sixth lens is less than a radius of curvature of the object side surface of the seventh lens, and an effective focal length f6 of the sixth lens, an effective focal length f7 of the seventh lens, a radius of curvature R11 of the object side surface of the sixth lens, and a radius of curvature R13 of the object side surface of the seventh lens satisfy: 0<(R11/f6)/(R13/f7)<1.5.

Furthermore, the radius of curvature R2 of the image side surface of the first lens, the refractive index N1 of the first lens, the radius of curvature R4 of the image side surface of the second lens, the refractive index N2 of the second lens, the radius of curvature R6 of the image side surface of the third lens, and the refractive index N3 of the third lens satisfy the following: 0<R2/(N1-1)/[R4/(N2-1)]+R4/(N2-1)/[R6/(N3-1)]<4.0.

Further, the dispersion coefficient V1 of the first lens, the center thickness CT1 of the first lens, the air gap T12 between the first lens and the second lens on the optical axis, the dispersion coefficient V2 of the second lens, the center thickness CT2 of the second lens, the air gap T23 between the second lens and the third lens on the optical axis, the dispersion coefficient V3 of the third lens, the center thickness CT3 of the third lens, and the air gap T34 between the third lens and the fourth lens on the optical axis satisfy: -5.0<[V1/(CT1+T12)-V2/(CT2+T23)-V3/(CT3+T34)]/3<0.

Further, the on-axis distance SAG11 between the intersection of the object side surface of the first lens and the optical axis to the effective radius vertex of the object side surface of the first lens, the effective focal length f1 of the first lens, the on-axis distance SAG41 between the intersection of the object side surface of the fourth lens and the optical axis to the effective radius vertex of the object side surface of the fourth lens, the effective focal length f4 of the fourth lens, the on-axis distance SAG61 between the intersection of the object side surface of the sixth lens and the optical axis to the effective radius vertex of the object side surface of the sixth lens, and the effective focal length f6 of the sixth lens satisfy the following: 2.0<1/(SAG11/f1-SAG41/f4-SAG61/f6)<5.0.

Furthermore, an effective focal length f3 of the third lens and an effective focal length f4 of the fourth lens satisfy: 0<(f3+f4)/(f3-f4)<1.0.

Furthermore, the combined focal length f123 of the first lens, the second lens and the third lens, the combined focal length f45 of the fourth lens and the fifth lens, the radius of curvature R1 of the object side surface of the first lens, the radius of curvature R3 of the object side surface of the second lens, the radius of curvature R5 of the object side surface of the third lens, the radius of curvature R7 of the object side surface of the fourth lens, and the radius of curvature R9 of the object side surface of the fifth lens satisfy: 0<f123/(R1+R3+R5)-f45/(R7+R9)<1.0.

Further, the air interval between the fourth lens and the fifth lens on the optical axis is greater than the air interval between the third lens and the fourth lens on the optical axis, the air interval between the fourth lens and the fifth lens on the optical axis is greater than the air interval between the fifth lens and the sixth lens on the optical axis, and the air interval T45 between the fourth lens and the fifth lens on the optical axis, the edge thickness ET4 of the fourth lens, the edge thickness ET5 of the fifth lens, the center thickness CT4 of the fourth lens, and the center thickness CT5 of the fifth lens satisfy the following: 1.5<T45/(ET4+ET5)+T45/(CT4+CT5)<2.5.

Further, the effective focal length f6 of the sixth lens and the effective focal length f7 of the seventh lens satisfy: |f6/f7|<1.0, the effective focal length f6 of the sixth lens and the effective focal length f5 of the fifth lens satisfy: |f6/f5|<1.0, and the effective focal length f6 of the sixth lens and the effective focal length f4 of the fourth lens satisfy: |f6/f4|<1.0.

Furthermore, the combined focal length f67 of the sixth lens and the seventh lens, the effective focal length f6 of the sixth lens, and the effective focal length f7 of the seventh lens satisfy the following relationship: 2.0<f67/f6-f67/f7<3.0.

Furthermore, the maximum effective radius of the object side surface of the seventh lens is less than 5, and the maximum effective radius DT71 of the object side surface of the seventh lens and the maximum effective radius DT72 of the image side surface of the seventh lens satisfy: DT72/DT71>1.0.

Further, the center thickness CT7 of the seventh lens is smaller than the thickness CT7i of any position from half of the maximum effective radius of the object-side surface of the seventh lens to the center of the seventh lens along the extending direction of the optical axis.

Further, a curvature radius R12 of the image side surface of the sixth lens, a curvature radius R11 of the object side surface of the sixth lens, a center thickness CT6 of the sixth lens, and an air gap T56 between the fifth lens and the sixth lens on the optical axis satisfy: 0<(R12+R11)/CT6-(R12-R11)/(T56+CT6)<10.0.

Furthermore, the entrance pupil diameter EPD of the optical imaging system, the curvature radius R2 of the image side surface of the first lens, the curvature radius R1 of the object side surface of the first lens, the maximum effective radius DT11 of the object side surface of the first lens, and the maximum effective radius DT12 of the image side surface of the first lens satisfy the following relationship: 1.0<EPD/(R2-R1)+EPD/(DT11+DT12)<2.0.

Furthermore, the object-side surface of the first lens is convex, the image-side surface of the first lens is concave, the object-side surface of the second lens is convex, and the image-side surface of the second lens is concave.

Furthermore, the image side surface of the third lens is a concave surface, and the object side surface of the fourth lens is a convex surface.

Furthermore, the object-side surface of the fifth lens is convex, the image-side surface of the fifth lens is concave, the object-side surface of the sixth lens is convex, and the image-side surface of the sixth lens is concave.

Furthermore, the first lens to the seventh lens are all non-cemented lenses.

According to another aspect of the present invention, an optical imaging system is provided, which has only seven lenses, and includes, from the object side to the image side of the optical imaging system: a first lens, the focal length of the first lens is positive; a second lens, the focal length of the second lens is negative; a third lens, the focal length of the third lens is negative; a fourth lens, the focal length of the fourth lens is positive; a fifth lens, the focal length of the fifth lens is negative; a sixth lens, the focal length of the sixth lens is positive; a seventh lens, the focal length of the seventh lens is negative, and the curvature radius of the object side surface of the seventh lens and the curvature radius of the image side surface of the seventh lens are less than zero; a distance TTL from the object side surface of the first lens to the imaging surface of the optical imaging system on the optical axis of the optical imaging system and half the diagonal length of the effective pixel area on the imaging surface ImgH satisfy the following: TTL/ImgH<1.3; the sixth lens The dispersion coefficient V6 of the first lens, the dispersion coefficient V7 of the seventh lens, the effective focal length f6 of the sixth lens, and the effective focal length f7 of the seventh lens satisfy: 7.5<(V6+V7)/2/(f6-f7)<9.0; the dispersion coefficient V1 of the first lens, the center thickness CT1 of the first lens, the air gap T12 between the first lens and the second lens on the optical axis, the dispersion coefficient V2 of the second lens, the center thickness CT2 of the second lens, the air gap T23 between the second lens and the third lens on the optical axis, the dispersion coefficient V3 of the third lens, the center thickness CT3 of the third lens, and the air gap T34 between the third lens and the fourth lens on the optical axis satisfy: -5.0<[V1/(CT1+T12)-V2/(CT2+T23)-V3/(CT3+T34)]/3<0.

Furthermore, the effective focal length f of the optical imaging system and the maximum field of view FOV of the optical imaging system satisfy: f*tan(FOV/2)>4.5.

Furthermore, the effective focal length f1 of the first lens, the maximum effective radius DT11 of the object side surface of the first lens, the maximum effective radius DT12 of the image side surface of the first lens, the effective focal length f2 of the second lens, the maximum effective radius DT21 of the object side surface of the second lens, and the maximum effective radius DT22 of the image side surface of the second lens satisfy the following: -5.0<f1/(DT11+DT12)+f2/(DT21+DT22)<-2.0.

Further, the air interval T67 between the sixth lens and the seventh lens on the optical axis satisfies: T67>Tij, wherein Tij is the air interval between the i-th lens to the j-th lens on the optical axis, i is 1, 2, 3, 4, 5, j=i+1, and the air interval T67 between the sixth lens and the seventh lens on the optical axis and the sum of the air intervals ∑AT between lenses of two adjacent optical imaging systems on the optical axis satisfy: T67/∑AT<0.5.

Further, a radius of curvature R11 of the object side surface of the sixth lens is less than 1.5, a radius of curvature of the object side surface of the sixth lens is less than a radius of curvature of the object side surface of the seventh lens, and an effective focal length f6 of the sixth lens, an effective focal length f7 of the seventh lens, a radius of curvature R11 of the object side surface of the sixth lens, and a radius of curvature R13 of the object side surface of the seventh lens satisfy: 0<(R11/f6)/(R13/f7)<1.5.

Furthermore, the radius of curvature R2 of the image side surface of the first lens, the refractive index N1 of the first lens, the radius of curvature R4 of the image side surface of the second lens, the refractive index N2 of the second lens, the radius of curvature R6 of the image side surface of the third lens, and the refractive index N3 of the third lens satisfy the following: 0<R2/(N1-1)/[R4/(N2-1)]+R4/(N2-1)/[R6/(N3-1)]<4.0.

Further, the on-axis distance SAG11 between the intersection of the object side surface of the first lens and the optical axis to the effective radius vertex of the object side surface of the first lens, the effective focal length f1 of the first lens, the on-axis distance SAG41 between the intersection of the object side surface of the fourth lens and the optical axis to the effective radius vertex of the object side surface of the fourth lens, the effective focal length f4 of the fourth lens, the on-axis distance SAG61 between the intersection of the object side surface of the sixth lens and the optical axis to the effective radius vertex of the object side surface of the sixth lens, and the effective focal length f6 of the sixth lens satisfy the following: 2.0<1/(SAG11/f1-SAG41/f4-SAG61/f6)<5.0.

Furthermore, an effective focal length f3 of the third lens and an effective focal length f4 of the fourth lens satisfy: 0<(f3+f4)/(f3-f4)<1.0.

Furthermore, the combined focal length f123 of the first lens, the second lens and the third lens, the combined focal length f45 of the fourth lens and the fifth lens, the radius of curvature R1 of the object side surface of the first lens, the radius of curvature R3 of the object side surface of the second lens, the radius of curvature R5 of the object side surface of the third lens, the radius of curvature R7 of the object side surface of the fourth lens, and the radius of curvature R9 of the object side surface of the fifth lens satisfy: 0<f123/(R1+R3+R5)-f45/(R7+R9)<1.0.

Further, the air interval between the fourth lens and the fifth lens on the optical axis is greater than the air interval between the third lens and the fourth lens on the optical axis, the air interval between the fourth lens and the fifth lens on the optical axis is greater than the air interval between the fifth lens and the sixth lens on the optical axis, and the air interval T45 between the fourth lens and the fifth lens on the optical axis, the edge thickness ET4 of the fourth lens, the edge thickness ET5 of the fifth lens, the center thickness CT4 of the fourth lens, and the center thickness CT5 of the fifth lens satisfy the following: 1.5<T45/(ET4+ET5)+T45/(CT4+CT5)<2.5.

Further, the effective focal length f6 of the sixth lens and the effective focal length f7 of the seventh lens satisfy: |f6/f7|<1.0, the effective focal length f6 of the sixth lens and the effective focal length f5 of the fifth lens satisfy: |f6/f5|<1.0, and the effective focal length f6 of the sixth lens and the effective focal length f4 of the fourth lens satisfy: |f6/f4|<1.0.

Furthermore, the combined focal length f67 of the sixth lens and the seventh lens, the effective focal length f6 of the sixth lens, and the effective focal length f7 of the seventh lens satisfy the following relationship: 2.0<f67/f6-f67/f7<3.0.

Furthermore, the maximum effective radius of the object side surface of the seventh lens is less than 5, and the maximum effective radius DT71 of the object side surface of the seventh lens and the maximum effective radius DT72 of the image side surface of the seventh lens satisfy: DT72/DT71>1.0.

Further, the center thickness CT7 of the seventh lens is smaller than the thickness CT7i of any position from half of the maximum effective radius of the object-side surface of the seventh lens to the center of the seventh lens along the extending direction of the optical axis.

Further, a curvature radius R12 of the image side surface of the sixth lens, a curvature radius R11 of the object side surface of the sixth lens, a center thickness CT6 of the sixth lens, and an air gap T56 between the fifth lens and the sixth lens on the optical axis satisfy: 0<(R12+R11)/CT6-(R12-R11)/(T56+CT6)<10.0.

Furthermore, the entrance pupil diameter EPD of the optical imaging system, the curvature radius R2 of the image side surface of the first lens, the curvature radius R1 of the object side surface of the first lens, the maximum effective radius DT11 of the object side surface of the first lens, and the maximum effective radius DT12 of the image side surface of the first lens satisfy the following relationship: 1.0<EPD/(R2-R1)+EPD/(DT11+DT12)<2.0.

Furthermore, the object-side surface of the first lens is convex, the image-side surface of the first lens is concave, the object-side surface of the second lens is convex, and the image-side surface of the second lens is concave.

Furthermore, the image-side surface of the third lens is a concave surface, and the object-side surface of the fourth lens is a convex surface.

Furthermore, the object-side surface of the fifth lens is convex, the image-side surface of the fifth lens is concave, the object-side surface of the sixth lens is convex, and the image-side surface of the sixth lens is concave.

By applying the technical solution of the present invention, the optical imaging system has only seven lenses, which include, from the object side to the image side of the optical imaging system, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens in sequence, wherein the focal length of the first lens is positive; the focal length of the second lens is negative; the focal length of the third lens is negative; the focal length of the fourth lens is positive; the focal length of the fifth lens is negative; the focal length of the sixth lens is positive; the focal length of the seventh lens is negative; the curvature radius of the object side surface of the seventh lens and the curvature radius of the image side surface of the seventh lens are less than zero; the curvature radius R13 of the object side surface of the seventh lens and the curvature radius R14 of the image side surface of the seventh lens satisfy :0<R14/R13<10; the distance TTL from the object side surface of the first lens to the imaging plane of the optical imaging system on the optical axis of the optical imaging system and half the diagonal length of the effective pixel area on the imaging plane ImgH satisfy: TTL/ImgH<1.3; the effective focal length f7 of the seventh lens and the curvature radius R13 of the object side surface of the seventh lens satisfy: 2.0<f7/R13<2.5; the dispersion coefficient V6 of the sixth lens, the dispersion coefficient V7 of the seventh lens, the effective focal length f6 of the sixth lens and the effective focal length f7 of the seventh lens satisfy: 7.5<(V6+V7)/2/(f6-f7)<9.0.

By setting the focal lengths of the first lens to the seventh lens to be positive and negative, the optical imaging system can have the characteristics of a large aperture, and it is also beneficial to correct various aberrations. By setting the curvature radius of the object side and the image side of the seventh lens to be less than zero, that is, the object side of the seventh lens is concave, and the image side of the seventh lens is convex, and R14/R13 is limited to a reasonable range, and in conjunction with the negative focal length of the seventh lens, the incident angle of the main light when the light emitted from the seventh lens reaches the imaging surface can be controlled within a reasonable range, thereby improving the matching with the chip and ensuring the imaging quality. At the same time, by controlling f7/R13 within a reasonable range, the shape of the seventh lens can be guaranteed, and the risk of ghost images generated by the seventh lens can be reduced. By controlling TTL/ImgH within a reasonable range, it is beneficial to control the total length of the optical imaging system, reduce the volume, and thus achieve miniaturization. By limiting (V6+V7)/2/(f6-f7) within a reasonable range, it can be ensured that the sixth lens and the seventh lens are both high-dispersion materials, which is beneficial to reducing the aberrations of the optical imaging system.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

FIG1 is a schematic diagram showing the structure of an optical imaging system according to Example 1 of the present invention;

2 to 5 respectively show an axial chromatic aberration curve, an astigmatism curve, a distortion curve, and a magnification chromatic aberration curve of the optical imaging system in FIG. 1 ;

FIG6 shows a schematic structural diagram of an optical imaging system according to Example 2 of the present invention;

7 to 10 respectively show an axial chromatic aberration curve, an astigmatism curve, a distortion curve, and a magnification chromatic aberration curve of the optical imaging system in FIG. 6 ;

FIG11 is a schematic diagram showing the structure of an optical imaging system according to Example 3 of the present invention;

12 to 15 respectively show an axial chromatic aberration curve, an astigmatism curve, a distortion curve, and a magnification chromatic aberration curve of the optical imaging system in FIG. 11 ;

FIG16 is a schematic diagram showing the structure of an optical imaging system according to Example 4 of the present invention;

17 to 20 respectively show an axial chromatic aberration curve, an astigmatism curve, a distortion curve, and a magnification chromatic aberration curve of the optical imaging system in FIG. 16 ;

FIG21 is a schematic diagram showing the structure of an optical imaging system according to Example 5 of the present invention;

22 to 25 respectively show an axial chromatic aberration curve, an astigmatism curve, a distortion curve, and a magnification chromatic aberration curve of the optical imaging system in FIG. 21 ;

FIG26 is a schematic diagram showing the structure of an optical imaging system according to Example 6 of the present invention;

27 to 30 respectively show an axial chromatic aberration curve, an astigmatism curve, a distortion curve, and a magnification chromatic aberration curve of the optical imaging system in FIG. 26 ;

FIG31 is a schematic diagram showing the structure of an optical imaging system according to Example 7 of the present invention;

32 to 35 respectively show an axial chromatic aberration curve, an astigmatism curve, a distortion curve, and a magnification chromatic aberration curve of the optical imaging system in FIG. 31 ;

FIG36 is a schematic diagram showing the structure of an optical imaging system according to Example 8 of the present invention;

37 to 40 respectively show the axial chromatic aberration curve, astigmatism curve, distortion curve and magnification chromatic aberration curve of the optical imaging system in FIG. 36 .

The above drawings include the following reference numerals:

STO, aperture; E1, first lens; S1, object-side surface of the first lens; S2, image-side surface of the first lens; E2, second lens; S3, object-side surface of the second lens; S4, image-side surface of the second lens; E3, third lens; S5, object-side surface of the third lens; S6, image-side surface of the third lens; E4, fourth lens; S7, object-side surface of the fourth lens; S8, image-side surface of the fourth lens; E5, fifth lens; S9, object-side surface of the fifth lens; S10, image-side surface of the fifth lens; E6, sixth lens; S11, object-side surface of the sixth lens; S12, image-side surface of the sixth lens; E7, seventh lens; S13, object-side surface of the seventh lens; S14, image-side surface of the seventh lens; E8, filter; S15, object-side surface of the filter; S16, image-side surface of the filter; S17, imaging surface.

DETAILED DESCRIPTION

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. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

It should be noted that, unless otherwise specified, all technical and scientific terms used in this application have the same meanings as commonly understood by ordinary technicians in the technical field to which this application belongs.

In the present invention, unless otherwise specified, the directional words used, such as "up, down, top, bottom", usually refer to the directions shown in the drawings, or to the components themselves in the vertical, perpendicular or gravity directions; similarly, for ease of understanding and description, "inside and outside" refer to the inside and outside relative to the outline of each component itself, but the above-mentioned directional words are not used to limit the present invention.

It should be noted that in this specification, the expressions of first, second, third, etc. are only used to distinguish one feature from another feature, and do not represent any limitation on the features. Therefore, without departing from the teaching of the present application, the first lens discussed below may also be referred to as the second lens or the third lens.

In the drawings, the thickness, size and shape of the lenses have been slightly exaggerated for ease of illustration. Specifically, the shapes of the spherical or aspherical surfaces shown in the drawings are shown by way of example. That is, the shapes of the spherical or aspherical surfaces are not limited to the shapes of the spherical or aspherical surfaces shown in the drawings. The drawings are for illustration only and are not drawn strictly to scale.

In this article, 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. The surface of each lens close to the object side is called the object side surface of the lens, and the surface of each lens close to the image side is called the image side surface of the lens. The judgment of the surface shape in the paraxial region can be based on the judgment method of the general knowledge in this field, and the positive and negative R value (R refers to the radius of curvature of the paraxial region, usually refers to the R value on the lens database (lens data) in the optical software) is used to judge the concave and convex. For the object side, when the R value is positive, it is judged as a convex surface, and when the R value is negative, it is judged as a concave surface; for the image side, when the R value is positive, it is judged as a concave surface, and when the R value is negative, it is judged as a convex surface.

In order to solve at least one of the problems of the optical imaging system in the prior art, namely, large size, poor imaging quality, and poor matching with a chip, the present invention provides an optical imaging system.

Embodiment 1

As shown in FIGS. 1 to 40 , the optical imaging system has only seven lenses, which include, from the object side to the image side of the optical imaging system, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens, the focal length of the first lens is positive; the focal length of the second lens is negative; the focal length of the third lens is negative; the focal length of the fourth lens is positive; the focal length of the fifth lens is negative; the focal length of the sixth lens is positive; the focal length of the seventh lens is negative, the radius of curvature of the object side surface of the seventh lens and the radius of curvature of the image side surface of the seventh lens are less than zero; the radius of curvature R13 of the object side surface of the seventh lens and the radius of curvature R14 of the image side surface of the seventh lens satisfy the following conditions: 0<R14/R13<10; the distance TTL from the object side surface of the first lens to the imaging plane of the optical imaging system on the optical axis of the optical imaging system and half the diagonal length of the effective pixel area on the imaging plane ImgH satisfy: TTL/ImgH<1.3; the effective focal length f7 of the seventh lens and the curvature radius R13 of the object side surface of the seventh lens satisfy: 2.0<f7/R13<2.5; the dispersion coefficient V6 of the sixth lens, the dispersion coefficient V7 of the seventh lens, the effective focal length f6 of the sixth lens and the effective focal length f7 of the seventh lens satisfy: 7.5<(V6+V7)/2/(f6-f7)<9.0.

By setting the focal lengths of the first lens to the seventh lens to be positively and negatively variable, the optical imaging system can have the characteristics of a large aperture, and it is also beneficial to correct various aberrations. By setting the curvature radii of the object side and the image side of the seventh lens to be less than zero, that is, the object side of the seventh lens is a concave surface, and the image side of the seventh lens is a convex surface, and at the same time limiting R14/R13 within a reasonable range, in conjunction with the negative focal length of the seventh lens, the incident angle of the main light emitted from the seventh lens when reaching the imaging surface can be controlled within a reasonable range, thereby improving the matching with the chip and ensuring the imaging quality. At the same time, by controlling f7/R13 within a reasonable range, the shape of the seventh lens can be guaranteed, and the risk of ghost images generated by the seventh lens can be reduced.

By controlling TTL/ImgH within a reasonable range, it is beneficial to control the total length of the optical imaging system, reduce the volume and achieve miniaturization. By limiting (V6+V7)/2/(f6-f7) within a reasonable range, it can ensure that the sixth lens and the seventh lens are both made of high dispersion materials, which is beneficial to reducing the aberration of the optical imaging system.

Preferably, a curvature radius R13 of the object-side surface of the seventh lens and a curvature radius R14 of the image-side surface of the seventh lens satisfy: 6.69≤R14/R13≤10.

Preferably, a distance TTL from the object side surface of the first lens to an imaging plane of the optical imaging system on the optical axis of the optical imaging system and half of the diagonal length of an effective pixel area on the imaging plane ImgH satisfy the following relationship: 1.10≤TTL/ImgH≤1.18.

Preferably, an effective focal length f7 of the seventh lens and a curvature radius R13 of the object side surface of the seventh lens satisfy: 2.10≤f7/R13≤2.19;

Preferably, the dispersion coefficient V6 of the sixth lens, the dispersion coefficient V7 of the seventh lens, the effective focal length f6 of the sixth lens, and the effective focal length f7 of the seventh lens satisfy: 7.94≤(V6+V7)/2/(f6-f7)≤8.56.

In this embodiment, the effective focal length f of the optical imaging system and the maximum field of view FOV of the optical imaging system satisfy: f*tan(FOV/2)>4.5. By limiting f*tan(FOV/2) within a reasonable range, the shooting range of the optical imaging system can be guaranteed, so that the system has a larger image plane and the picture sense of the system is improved. Preferably, 4.66≤f*tan(FOV/2)≤5.29.

In this embodiment, the effective focal length f1 of the first lens, the maximum effective radius DT11 of the object side of the first lens, the maximum effective radius DT12 of the image side of the first lens, the effective focal length f2 of the second lens, the maximum effective radius DT21 of the object side of the second lens, and the maximum effective radius DT22 of the image side of the second lens satisfy: -5.0<f1/(DT11+DT12)+f2/(DT21+DT22)<-2.0. By limiting f1/(DT11+DT12)+f2/(DT21+DT22) within a reasonable range, the effective focal lengths of the first lens and the second lens can be reasonably allocated, the aberration of the system can be reduced, and the imaging quality of the system can be improved. Preferably, -4.41≤f1/(DT11+DT12)+f2/(DT21+DT22)≤-2.69.

In this embodiment, the air interval T67 between the sixth lens and the seventh lens on the optical axis satisfies: T67>Tij, where Tij is the air interval between the i-th lens and the j-th lens on the optical axis, i is 1, 2, 3, 4, 5, j=i+1, and the air interval T67 between the sixth lens and the seventh lens on the optical axis and the sum of the air intervals ∑AT between the lenses of two adjacent optical imaging systems on the optical axis satisfy: T67/∑AT<0.5. Controlling the air interval between the sixth lens and the seventh lens on the optical axis to the maximum can ensure that the large-diameter sixth lens and the seventh lens have a large enough assembly space, reducing the difficulty of assembly. At the same time, with T67/∑AT within a reasonable range, the intervals between the lenses on the optical axis can be reasonably allocated, which can avoid excessive light deflection and reduce the difficulty of processing the optical imaging lens. Preferably, 0.39≤T67/∑AT≤0.41.

In this embodiment, the radius of curvature R11 of the object side surface of the sixth lens is less than 1.5, the radius of curvature of the object side surface of the sixth lens is less than the radius of curvature of the object side surface of the seventh lens, and the effective focal length f6 of the sixth lens, the effective focal length f7 of the seventh lens, the radius of curvature R11 of the object side surface of the sixth lens, and the radius of curvature R13 of the object side surface of the seventh lens satisfy: 0<(R11/f6)/(R13/f7)<1.5. By limiting (R11/f6)/(R13/f7) within a reasonable range, the curvature degree of the object side surface of the sixth lens and the object side surface of the seventh lens can be controlled, and at the same time, the effective focal lengths of the sixth lens and the seventh lens are matched, so that the surface shapes of the sixth lens and the seventh lens are more reasonable, so that the sixth lens and the seventh lens have better molding and processing characteristics. Preferably, 1.02≤(R11/f6)/(R13/f7)≤1.07.

In this embodiment, the radius of curvature R2 of the image side surface of the first lens, the refractive index N1 of the first lens, the radius of curvature R4 of the image side surface of the second lens, the refractive index N2 of the second lens, the radius of curvature R6 of the image side surface of the third lens, and the refractive index N3 of the third lens satisfy the following relationship: 0<R2/(N1-1)/[R4/(N2-1)]+R4/(N2-1)/[R6/(N3-1)]<4.0. By limiting R2/(N1-1)/[R4/(N2-1)]+R4/(N2-1)/[R6/(N3-1)] within a reasonable range, it is possible to ensure that the first lens is made of a low-refractive material, and the second and third lenses are made of high-refractive materials, thereby reducing the distortion of the optical imaging system and reducing aberrations, thereby improving image quality. Preferably, 1.89≤R2/(N1-1)/[R4/(N2-1)]+R4/(N2-1)/[R6/(N3-1)]≤2.81.

In this embodiment, the dispersion coefficient V1 of the first lens, the center thickness CT1 of the first lens, the air interval T12 between the first lens and the second lens on the optical axis, the dispersion coefficient V2 of the second lens, the center thickness CT2 of the second lens, the air interval T23 between the second lens and the third lens on the optical axis, the dispersion coefficient V3 of the third lens, the center thickness CT3 of the third lens, and the air interval T34 between the third lens and the fourth lens on the optical axis satisfy: -5.0<[V1/(CT1+T12)-V2/(CT2+T23)-V3/(CT3+T34)]/3<0. By limiting [V1/(CT1+T12)-V2/(CT2+T23)-V3/(CT3+T34)]/3 within a reasonable range, it can be ensured that the first lens is made of high dispersion material, and the second lens and the third lens are made of low dispersion material, so that the distortion of the optical imaging system can be reduced, the aberration can be reduced, and the image quality can be improved. Preferably, -4.04≤[V1/(CT1+T12)-V2/(CT2+T23)-V3/(CT3+T34)]/3≤-2.22.

In this embodiment, the on-axis distance SAG11 between the intersection of the object side surface of the first lens and the optical axis to the effective radius vertex of the object side surface of the first lens, the effective focal length f1 of the first lens, the on-axis distance SAG41 between the intersection of the object side surface of the fourth lens and the optical axis to the effective radius vertex of the object side surface of the fourth lens, the effective focal length f4 of the fourth lens, the on-axis distance SAG61 between the intersection of the object side surface of the sixth lens and the optical axis to the effective radius vertex of the object side surface of the sixth lens, and the effective focal length f6 of the sixth lens satisfy the following conditions: 2.0<1/(SAG11/f1-SAG41/f4-SAG61/f6)<5.0. By limiting 1/(SAG11/f1-SAG41/f4-SAG61/f6) within a reasonable range, the distortion contribution of the first lens, the fourth lens and the sixth lens can be controlled within a reasonable range, so that the distortion variation of each field of view of the optical imaging system is within a reasonable range, which is conducive to meeting the requirements of later software debugging and ensuring the imaging quality. Preferably, 3.80≤1/(SAG11/f1-SAG41/f4-SAG61/f6)≤4.52.

In this embodiment, the effective focal length f3 of the third lens and the effective focal length f4 of the fourth lens satisfy: 0<(f3+f4)/(f3-f4)<1.0. By limiting (f3+f4)/(f3-f4) within a reasonable range, it is beneficial to better balance the aberrations at the third lens and the fourth lens, and to improve the imaging quality. Preferably, 0.22≤(f3+f4)/(f3-f4)≤0.76.

In this embodiment, the combined focal length f123 of the first lens, the second lens and the third lens, the combined focal length f45 of the fourth lens and the fifth lens, the radius of curvature R1 of the object side surface of the first lens, the radius of curvature R3 of the object side surface of the second lens, the radius of curvature R5 of the object side surface of the third lens, the radius of curvature R7 of the object side surface of the fourth lens, and the radius of curvature R9 of the object side surface of the fifth lens satisfy the following conditions: 0<f123/(R1+R3+R5)-f45/(R7+R9)<1.0. By limiting f123/(R1+R3+R5)-f45/(R7+R9) within a reasonable range, the effective focal lengths of the first lens to the fifth lens can be reasonably allocated, the aberration of the optical imaging system can be reduced, and the imaging quality can be improved. At the same time, it is also beneficial to improve the rationality of the surface shapes of the first lens to the fifth lens, and to facilitate the processing and molding of the first lens to the fifth lens. Preferably, 0.25≤f123/(R1+R3+R5)-f45/(R7+R9)≤0.53.

In this embodiment, the air interval between the fourth lens and the fifth lens on the optical axis is greater than the air interval between the third lens and the fourth lens on the optical axis, the air interval between the fourth lens and the fifth lens on the optical axis is greater than the air interval between the fifth lens and the sixth lens on the optical axis, and the air interval T45 between the fourth lens and the fifth lens on the optical axis, the edge thickness ET4 of the fourth lens, the edge thickness ET5 of the fifth lens, the center thickness CT4 of the fourth lens, and the center thickness CT5 of the fifth lens satisfy: 1.5<T45/(ET4+ET5)+T45/(CT4+CT5)<2.5. Setting the air interval between the fourth lens and the fifth lens on the optical axis to be greater than the air interval between the third lens and the fourth lens, and the fifth lens and the sixth lens on the optical axis can ensure that the fourth lens and the fifth lens have a more reasonable position on the optical axis. By limiting T45/(ET4+ET5)+T45/(CT4+CT5) within a reasonable range, the processing and molding of the third lens, the fourth lens, and the fifth lens can be ensured while miniaturizing the optical imaging system, thereby reducing the performance loss caused by poor surface shape. Preferably, 1.78≤T45/(ET4+ET5)+T45/(CT4+CT5)≤2.02.

In this embodiment, the effective focal length f6 of the sixth lens and the effective focal length f7 of the seventh lens satisfy: |f6/f7|<1.0, the effective focal length f6 of the sixth lens and the effective focal length f5 of the fifth lens satisfy: |f6/f5|<1.0, and the effective focal length f6 of the sixth lens and the effective focal length f4 of the fourth lens satisfy: |f6/f4|<1.0. By controlling the proportional relationship between the effective focal length of the sixth lens and the effective focal lengths of the seventh lens, the fifth lens and the fourth lens, the effective focal lengths of the fourth lens, the fifth lens, the sixth lens and the seventh lens can be reasonably allocated, the distortion of the external field of view can be reduced, and the distortion of the optical imaging system can be controlled to improve the imaging quality. Preferably, 0.69≤|f6/f7|≤0.73, 0.56≤|f6/f5|≤0.60, 0.07≤|f6/f4|≤0.11.

In this embodiment, the combined focal length f67 of the sixth lens and the seventh lens, the effective focal length f6 of the sixth lens, and the effective focal length f7 of the seventh lens satisfy the following relationship: 2.0<f67/f6-f67/f7<3.0. By limiting f67/f6-f67/f7 within a reasonable range, the effective focal lengths of the sixth lens and the seventh lens can be reasonably allocated, thereby controlling the CRA (the incident angle of the main light on the imaging surface) under the condition of half of the maximum field of view of the optical imaging system, ensuring the matching of the CRA with the chip, reducing the chip response problem caused by CRA mismatch, and ensuring the imaging quality. Preferably, 2.75≤f67/f6-f67/f7≤2.95.

In this embodiment, the maximum effective radius of the object side of the seventh lens is less than 5, and the maximum effective radius DT71 of the object side of the seventh lens and the maximum effective radius DT72 of the image side of the seventh lens satisfy: DT72/DT71>1.0. By controlling DT72/DT71 within a reasonable range, the processing and molding of the large-diameter seventh lens can be guaranteed, and it is also helpful to reduce the sagittal astigmatism of the system and improve the imaging quality. Preferably, 1.04≤DT72/DT71≤1.11.

In this embodiment, the center thickness CT7 of the seventh lens is less than the thickness CT7i of any position from half of the maximum effective radius of the object side surface of the seventh lens to the center of the seventh lens along the extension direction of the optical axis. This arrangement can ensure the processing and molding of the seventh lens and reduce the performance loss caused by poor surface shape.

It should be noted that the center of the seventh lens in the present application refers to the portion of the seventh lens that is half of its maximum effective radius close to the optical axis, that is, CT7i is the thickness of the portion of the seventh lens that is half of its maximum effective radius close to the optical axis at any position along the extension direction of the optical axis. Or, it can be said that the thickness of the seventh lens at any position in the area excluding the center point of the seventh lens within the range of a circle drawn with the center point of the object side surface of the seventh lens as the point and half of the maximum effective radius as the radius along the extension direction of the optical axis.

In this embodiment, the radius of curvature R12 of the image side surface of the sixth lens, the radius of curvature R11 of the object side surface of the sixth lens, the center thickness CT6 of the sixth lens, and the air interval T56 between the fifth lens and the sixth lens on the optical axis satisfy: 0<(R12+R11)/CT6-(R12-R11)/(T56+CT6)<10.0. By limiting (R12+R11)/CT6-(R12-R11)/(T56+CT6) within a reasonable range, the processing and molding of the sixth lens can be guaranteed, and the performance loss caused by poor surface shape can be reduced. Preferably, 8.41≤(R12+R11)/CT6-(R12-R11)/(T56+CT6)≤9.99.

In this embodiment, the entrance pupil diameter EPD of the optical imaging system, the curvature radius R2 of the image side surface of the first lens, the curvature radius R1 of the object side surface of the first lens, the maximum effective radius DT11 of the object side surface of the first lens, and the maximum effective radius DT12 of the image side surface of the first lens satisfy the following relationship: 1.0<EPD/(R2-R1)+EPD/(DT11+DT12)<2.0. By limiting EPD/(R2-R1)+EPD/(DT11+DT12) within a reasonable range, the amount of light entering the system can be guaranteed, and better photographic effects can be achieved in darker environments. At the same time, the shape of the first lens can be controlled, the sensitivity of the system can be reduced, and the yield of the system can be improved. Preferably, 1.41≤EPD/(R2-R1)+EPD/(DT11+DT12)≤1.65.

In this embodiment, the object side surface of the first lens is convex, the image side surface of the first lens is concave, the object side surface of the second lens is convex, and the image side surface of the second lens is concave. This arrangement can reduce the contribution of the first lens and the second lens to the spherical aberration of the entire system, thereby improving the imaging quality.

In this embodiment, the image side surface of the third lens is concave, and the object side surface of the fourth lens is convex. This arrangement can reduce the ghost images caused by the third lens and the fourth lens, reduce the noise in the photographed image, and make the image clearer.

In this embodiment, the object side surface of the fifth lens is convex, the image side surface of the fifth lens is concave, the object side surface of the sixth lens is convex, and the image side surface of the sixth lens is concave. This arrangement can control the surface shapes of the fifth lens and the sixth lens, reduce the off-axis aberration of the system, and thus improve the image quality of the system.

In this embodiment, the first lens to the seventh lens are all non-cemented lenses. Using non-cemented lenses can facilitate maintenance of the optical imaging system.

Embodiment 2

As shown in Figures 1 to 40, the optical imaging system has only seven lenses, which include a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens from the object side to the image side of the optical imaging system, the focal length of the first lens is positive; the focal length of the second lens is negative; the focal length of the third lens is negative; the focal length of the fourth lens is positive; the focal length of the fifth lens is negative; the focal length of the sixth lens is positive; the focal length of the seventh lens is negative, the curvature radius of the object side surface of the seventh lens and the curvature radius of the image side surface of the seventh lens are less than zero; the distance TTL from the object side surface of the first lens to the imaging plane of the optical imaging system on the optical axis of the optical imaging system and the half of the diagonal length of the effective pixel area on the imaging plane ImgH satisfy the following: TTL/ImgH<1.3; the dispersion coefficient V of the sixth lens 6. The dispersion coefficient V7 of the seventh lens, the effective focal length f6 of the sixth lens, and the effective focal length f7 of the seventh lens satisfy the following: 7.5<(V6+V7)/2/(f6-f7)<9.0; the dispersion coefficient V1 of the first lens, the center thickness CT1 of the first lens, the air gap T12 between the first lens and the second lens on the optical axis, the dispersion coefficient V2 of the second lens, the center thickness CT2 of the second lens, the air gap T23 between the second lens and the third lens on the optical axis, the dispersion coefficient V3 of the third lens, the center thickness CT3 of the third lens, and the air gap T34 between the third lens and the fourth lens on the optical axis satisfy the following: -5.0<[V1/(CT1+T12)-V2/(CT2+T23)-V3/(CT3+T34)]/3<0.

By setting the focal lengths of the first lens to the seventh lens to be positively and negatively variable, the optical imaging system can have the characteristics of a large aperture, and it is also beneficial to correct various aberrations. By setting the curvature radii of the object side and the image side of the seventh lens to be less than zero, that is, the object side of the seventh lens is a concave surface, and the image side of the seventh lens is a convex surface, in combination with the negative focal length of the seventh lens, the incident angle of the main light emitted from the seventh lens when reaching the imaging surface can be controlled within a reasonable range, thereby improving the matching with the chip and ensuring the imaging quality.

By controlling TTL/ImgH within a reasonable range, it is beneficial to control the total length of the optical imaging system, reduce the volume and achieve miniaturization. By limiting (V6+V7)/2/(f6-f7) within a reasonable range, it can ensure that the sixth lens and the seventh lens are both made of high-dispersion materials, which is beneficial to reducing the aberration of the optical imaging system. By limiting [V1/(CT1+T12)-V2/(CT2+T23)-V3/(CT3+T34)]/3 within a reasonable range, it can ensure that the first lens is made of high-dispersion material, and the second and third lenses are made of low-dispersion materials, which can reduce the distortion of the optical imaging system, reduce aberrations, and thus improve image quality.

Preferably, a distance TTL from the object side surface of the first lens to an imaging plane of the optical imaging system on the optical axis of the optical imaging system and half of the diagonal length of an effective pixel area on the imaging plane ImgH satisfy the following relationship: 1.10≤TTL/ImgH≤1.18.

Preferably, the dispersion coefficient V6 of the sixth lens, the dispersion coefficient V7 of the seventh lens, the effective focal length f6 of the sixth lens, and the effective focal length f7 of the seventh lens satisfy: 7.94≤(V6+V7)/2/(f6-f7)≤8.56.

Preferably, the dispersion coefficient V1 of the first lens, the center thickness CT1 of the first lens, the air gap T12 between the first lens and the second lens on the optical axis, the dispersion coefficient V2 of the second lens, the center thickness CT2 of the second lens, the air gap T23 between the second lens and the third lens on the optical axis, the dispersion coefficient V3 of the third lens, the center thickness CT3 of the third lens, and the air gap T34 between the third lens and the fourth lens on the optical axis satisfy: -4.04≤[V1/(CT1+T12)-V2/(CT2+T23)-V3/(CT3+T34)]/3≤-2.22.

In this embodiment, the effective focal length f of the optical imaging system and the maximum field of view FOV of the optical imaging system satisfy: f*tan(FOV/2)>4.5. By limiting f*tan(FOV/2) within a reasonable range, the shooting range of the optical imaging system can be guaranteed, so that the system has a larger image plane and the picture sense of the system is improved. Preferably, 4.66≤f*tan(FOV/2)≤5.29.

In this embodiment, the effective focal length f1 of the first lens, the maximum effective radius DT11 of the object side of the first lens, the maximum effective radius DT12 of the image side of the first lens, the effective focal length f2 of the second lens, the maximum effective radius DT21 of the object side of the second lens, and the maximum effective radius DT22 of the image side of the second lens satisfy: -5.0<f1/(DT11+DT12)+f2/(DT21+DT22)<-2.0. By limiting f1/(DT11+DT12)+f2/(DT21+DT22) within a reasonable range, the effective focal lengths of the first lens and the second lens can be reasonably allocated, the aberration of the system can be reduced, and the imaging quality of the system can be improved. Preferably, -4.41≤f1/(DT11+DT12)+f2/(DT21+DT22)≤-2.69.

In this embodiment, the air interval T67 between the sixth lens and the seventh lens on the optical axis satisfies: T67>Tij, where Tij is the air interval between the i-th lens and the j-th lens on the optical axis, i is 1, 2, 3, 4, 5, j=i+1, and the air interval T67 between the sixth lens and the seventh lens on the optical axis and the sum of the air intervals ∑AT between the lenses of two adjacent optical imaging systems on the optical axis satisfy: T67/∑AT<0.5. Controlling the air interval between the sixth lens and the seventh lens on the optical axis to the maximum can ensure that the large-diameter sixth lens and the seventh lens have a large enough assembly space, reducing the difficulty of assembly. At the same time, with T67/∑AT within a reasonable range, the intervals between the lenses on the optical axis can be reasonably allocated, which can avoid excessive light deflection and reduce the difficulty of processing the optical imaging lens. Preferably, 0.39≤T67/∑AT≤0.41.

In this embodiment, the radius of curvature R11 of the object side surface of the sixth lens is less than 1.5, the radius of curvature of the object side surface of the sixth lens is less than the radius of curvature of the object side surface of the seventh lens, and the effective focal length f6 of the sixth lens, the effective focal length f7 of the seventh lens, the radius of curvature R11 of the object side surface of the sixth lens, and the radius of curvature R13 of the object side surface of the seventh lens satisfy: 0<(R11/f6)/(R13/f7)<1.5. By limiting (R11/f6)/(R13/f7) within a reasonable range, the curvature degree of the object side surface of the sixth lens and the object side surface of the seventh lens can be controlled, and at the same time, the effective focal lengths of the sixth lens and the seventh lens are matched, so that the surface shapes of the sixth lens and the seventh lens are more reasonable, so that the sixth lens and the seventh lens have better molding and processing characteristics. Preferably, 1.02≤(R11/f6)/(R13/f7)≤1.07.

In this embodiment, the radius of curvature R2 of the image side surface of the first lens, the refractive index N1 of the first lens, the radius of curvature R4 of the image side surface of the second lens, the refractive index N2 of the second lens, the radius of curvature R6 of the image side surface of the third lens, and the refractive index N3 of the third lens satisfy the following relationship: 0<R2/(N1-1)/[R4/(N2-1)]+R4/(N2-1)/[R6/(N3-1)]<4.0. By limiting R2/(N1-1)/[R4/(N2-1)]+R4/(N2-1)/[R6/(N3-1)] within a reasonable range, it is possible to ensure that the first lens is made of a low-refractive material, and the second and third lenses are made of high-refractive materials, thereby reducing the distortion of the optical imaging system and reducing aberrations, thereby improving image quality. Preferably, 1.89≤R2/(N1-1)/[R4/(N2-1)]+R4/(N2-1)/[R6/(N3-1)]≤2.81.

In this embodiment, the on-axis distance SAG11 between the intersection of the object side surface of the first lens and the optical axis to the effective radius vertex of the object side surface of the first lens, the effective focal length f1 of the first lens, the on-axis distance SAG41 between the intersection of the object side surface of the fourth lens and the optical axis to the effective radius vertex of the object side surface of the fourth lens, the effective focal length f4 of the fourth lens, the on-axis distance SAG61 between the intersection of the object side surface of the sixth lens and the optical axis to the effective radius vertex of the object side surface of the sixth lens, and the effective focal length f6 of the sixth lens satisfy the following conditions: 2.0<1/(SAG11/f1-SAG41/f4-SAG61/f6)<5.0. By limiting 1/(SAG11/f1-SAG41/f4-SAG61/f6) within a reasonable range, the distortion contribution of the first lens, the fourth lens and the sixth lens can be controlled within a reasonable range, so that the distortion variation of each field of view of the optical imaging system is within a reasonable range, which is conducive to meeting the requirements of later software debugging and ensuring the imaging quality. Preferably, 3.80≤1/(SAG11/f1-SAG41/f4-SAG61/f6)≤4.52.

In this embodiment, the effective focal length f3 of the third lens and the effective focal length f4 of the fourth lens satisfy: 0<(f3+f4)/(f3-f4)<1.0. By limiting (f3+f4)/(f3-f4) within a reasonable range, it is beneficial to better balance the aberrations at the third lens and the fourth lens, and to improve the imaging quality. Preferably, 0.22≤(f3+f4)/(f3-f4)≤0.76.

In this embodiment, the combined focal length f123 of the first lens, the second lens and the third lens, the combined focal length f45 of the fourth lens and the fifth lens, the radius of curvature R1 of the object side surface of the first lens, the radius of curvature R3 of the object side surface of the second lens, the radius of curvature R5 of the object side surface of the third lens, the radius of curvature R7 of the object side surface of the fourth lens, and the radius of curvature R9 of the object side surface of the fifth lens satisfy the following conditions: 0<f123/(R1+R3+R5)-f45/(R7+R9)<1.0. By limiting f123/(R1+R3+R5)-f45/(R7+R9) within a reasonable range, the effective focal lengths of the first lens to the fifth lens can be reasonably allocated, the aberration of the optical imaging system can be reduced, and the imaging quality can be improved. At the same time, it is also beneficial to improve the rationality of the surface shapes of the first lens to the fifth lens, and to facilitate the processing and molding of the first lens to the fifth lens. Preferably, 0.25≤f123/(R1+R3+R5)-f45/(R7+R9)≤0.53.

In this embodiment, the air interval between the fourth lens and the fifth lens on the optical axis is greater than the air interval between the third lens and the fourth lens on the optical axis, the air interval between the fourth lens and the fifth lens on the optical axis is greater than the air interval between the fifth lens and the sixth lens on the optical axis, and the air interval T45 between the fourth lens and the fifth lens on the optical axis, the edge thickness ET4 of the fourth lens, the edge thickness ET5 of the fifth lens, the center thickness CT4 of the fourth lens, and the center thickness CT5 of the fifth lens satisfy: 1.5<T45/(ET4+ET5)+T45/(CT4+CT5)<2.5. Setting the air interval between the fourth lens and the fifth lens on the optical axis to be greater than the air interval between the third lens and the fourth lens, and the fifth lens and the sixth lens on the optical axis can ensure that the fourth lens and the fifth lens have a more reasonable position on the optical axis. By limiting T45/(ET4+ET5)+T45/(CT4+CT5) within a reasonable range, the processing and molding of the third lens, the fourth lens, and the fifth lens can be ensured while miniaturizing the optical imaging system, thereby reducing the performance loss caused by poor surface shape. Preferably, 1.78≤T45/(ET4+ET5)+T45/(CT4+CT5)≤2.02.

In this embodiment, the effective focal length f6 of the sixth lens and the effective focal length f7 of the seventh lens satisfy: |f6/f7|<1.0, the effective focal length f6 of the sixth lens and the effective focal length f5 of the fifth lens satisfy: |f6/f5|<1.0, and the effective focal length f6 of the sixth lens and the effective focal length f4 of the fourth lens satisfy: |f6/f4|<1.0. By controlling the proportional relationship between the effective focal length of the sixth lens and the effective focal lengths of the seventh lens, the fifth lens and the fourth lens, the effective focal lengths of the fourth lens, the fifth lens, the sixth lens and the seventh lens can be reasonably allocated, the distortion of the external field of view can be reduced, and the distortion of the optical imaging system can be controlled to improve the imaging quality. Preferably, 0.69≤|f6/f7|≤0.73, 0.56≤|f6/f5|≤0.60, 0.07≤|f6/f4|≤0.11.

In this embodiment, the combined focal length f67 of the sixth lens and the seventh lens, the effective focal length f6 of the sixth lens, and the effective focal length f7 of the seventh lens satisfy the following relationship: 2.0<f67/f6-f67/f7<3.0. By limiting f67/f6-f67/f7 within a reasonable range, the effective focal lengths of the sixth lens and the seventh lens can be reasonably allocated, thereby controlling the CRA (the incident angle of the main light on the imaging surface) under the condition of half of the maximum field of view of the optical imaging system, ensuring the matching of the CRA with the chip, reducing the chip response problem caused by CRA mismatch, and ensuring the imaging quality. Preferably, 2.75≤f67/f6-f67/f7≤2.95.

In this embodiment, the maximum effective radius of the object side of the seventh lens is less than 5, and the maximum effective radius DT71 of the object side of the seventh lens and the maximum effective radius DT72 of the image side of the seventh lens satisfy: DT72/DT71>1.0. By controlling DT72/DT71 within a reasonable range, the processing and molding of the large-diameter seventh lens can be guaranteed, and it is also helpful to reduce the sagittal astigmatism of the system and improve the imaging quality. Preferably, 1.04≤DT72/DT71≤1.11.

In this embodiment, the center thickness CT7 of the seventh lens is less than the thickness CT7i of any position from half of the maximum effective radius of the object side surface of the seventh lens to the center of the seventh lens along the extension direction of the optical axis. This arrangement can ensure the processing and molding of the seventh lens and reduce the performance loss caused by poor surface shape.

It should be noted that, in the present application, the center of the seventh lens refers to a portion of half the maximum effective radius of the seventh lens close to the optical axis, that is, CT7i is a thickness along the extension direction of the optical axis at any position of the portion of half the maximum effective radius of the seventh lens close to the optical axis.

In this embodiment, the radius of curvature R12 of the image side surface of the sixth lens, the radius of curvature R11 of the object side surface of the sixth lens, the center thickness CT6 of the sixth lens, and the air interval T56 between the fifth lens and the sixth lens on the optical axis satisfy: 0<(R12+R11)/CT6-(R12-R11)/(T56+CT6)<10.0. By limiting (R12+R11)/CT6-(R12-R11)/(T56+CT6) within a reasonable range, the processing and molding of the sixth lens can be guaranteed, and the performance loss caused by poor surface shape can be reduced. Preferably, 8.41≤(R12+R11)/CT6-(R12-R11)/(T56+CT6)≤9.99.

In this embodiment, the entrance pupil diameter EPD of the optical imaging system, the curvature radius R2 of the image side surface of the first lens, the curvature radius R1 of the object side surface of the first lens, the maximum effective radius DT11 of the object side surface of the first lens, and the maximum effective radius DT12 of the image side surface of the first lens satisfy the following relationship: 1.0<EPD/(R2-R1)+EPD/(DT11+DT12)<2.0. By limiting EPD/(R2-R1)+EPD/(DT11+DT12) within a reasonable range, the amount of light entering the system can be guaranteed, and better photographic effects can be achieved in darker environments. At the same time, the shape of the first lens can be controlled, the sensitivity of the system can be reduced, and the yield of the system can be improved. Preferably, 1.41≤EPD/(R2-R1)+EPD/(DT11+DT12)≤1.65.

In this embodiment, the object side surface of the first lens is convex, the image side surface of the first lens is concave, the object side surface of the second lens is convex, and the image side surface of the second lens is concave. This arrangement can reduce the contribution of the first lens and the second lens to the spherical aberration of the entire system, thereby improving the imaging quality.

In this embodiment, the image side surface of the third lens is concave, and the object side surface of the fourth lens is convex. This arrangement can reduce the ghost images caused by the third lens and the fourth lens, reduce the noise in the photographed image, and make the image clearer.

In this embodiment, the object side surface of the fifth lens is convex, the image side surface of the fifth lens is concave, the object side surface of the sixth lens is convex, and the image side surface of the sixth lens is concave. This arrangement can control the surface shapes of the fifth lens and the sixth lens, reduce the off-axis aberration of the system, and thus improve the image quality of the system.

In this embodiment, the first lens to the seventh lens are all non-cemented lenses. Using non-cemented lenses can facilitate maintenance of the optical imaging system.

Optionally, the optical imaging system may further include a filter for correcting color deviation and/or a protective glass for protecting a photosensitive element located on the imaging surface.

The optical imaging system in the present application may use multiple lenses, such as the seven lenses mentioned above. By reasonably allocating the focal length, surface shape, center thickness of each lens, and axial distance between lenses, etc., the aperture of the optical imaging system can be effectively increased, the sensitivity of the lens can be reduced, and the processability of the lens can be improved, making the optical imaging system more conducive to production and processing and applicable to portable electronic devices such as smart phones. The above-mentioned optical imaging system also has the advantages of large aperture, large field of view, and good imaging quality, which can meet the needs of miniaturization of smart electronic products.

In the present application, at least one of the mirror surfaces of each lens is an aspherical mirror surface. The characteristic of an aspherical lens is that the curvature changes continuously from the center of the lens to the periphery of the lens. Unlike a spherical lens having a constant curvature from the center of the lens to the periphery of the lens, an aspherical lens has a better curvature radius characteristic and has the advantages of improving distortion aberration and improving astigmatism aberration. After using an aspherical lens, the aberration occurring during imaging can be eliminated as much as possible, thereby improving the imaging quality.

However, those skilled in the art should understand that, without departing from the technical solution claimed in the present application, the number of lenses constituting the optical imaging system can be changed to obtain the various results and advantages described in this specification. For example, although seven lenses are used as an example in the embodiments, the optical imaging system is not limited to including seven lenses. If necessary, the optical imaging system may also include other numbers of lenses.

The following further describes examples of specific surface shapes and parameters of the optical imaging system applicable to the above-mentioned embodiments with reference to the accompanying drawings.

It should be noted that any one of the following examples 1 to 8 is applicable to all embodiments of the present application.

Example 1

As shown in Figures 1 to 5, an optical imaging system of Example 1 of the present application is described. Figure 1 shows a schematic diagram of the structure of the optical imaging system of Example 1.

As shown in FIG. 1 , the optical imaging system includes, from the object side to the image side, an aperture STO, a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a sixth lens E6, a seventh lens E7, a filter E8 and an imaging surface S17.

The first lens E1 has positive focal power, the object side surface S1 of the first lens is convex, and the image side surface S2 of the first lens is concave. The second lens E2 has negative focal power, the object side surface S3 of the second lens is convex, and the image side surface S4 of the second lens is concave. The third lens E3 has negative focal power, the object side surface S5 of the third lens is convex, and the image side surface S6 of the third lens is concave. The fourth lens E4 has positive focal power, the object side surface S7 of the fourth lens is convex, and the image side surface S8 of the fourth lens is concave. The fifth lens E5 has negative focal power, the object side surface S9 of the fifth lens is convex, and the image side surface S10 of the fifth lens is concave. The sixth lens E6 has positive focal power, the object side surface S11 of the sixth lens is convex, and the image side surface S12 of the sixth lens is concave. The seventh lens E7 has negative focal power, the object side surface S13 of the seventh lens is concave, and the image side surface S14 of the seventh lens is convex. The filter E8 has an object side surface S15 and an image side surface S16. Light from the object passes through the surfaces S1 to S16 in sequence and is finally imaged on the imaging surface S17.

In this example, the total effective focal length f of the optical imaging system is 5.34 mm, the maximum field of view FOV of the optical imaging system is 88.0°, the total length TTL of the optical imaging system is 6.20 mm, half of the diagonal length of the effective pixel area on the imaging plane of the optical imaging system ImgH is 5.27 mm, and the aperture value f/EPD of the optical imaging system is 1.88.

Table 1 shows a basic structural parameter table of the optical imaging system of Example 1, wherein the units of the radius of curvature and thickness/distance are all millimeters (mm).

Table 1

In Example 1, the object side surface and the image side surface of any lens from the first lens E1 to the seventh lens E7 are both aspherical surfaces, and the surface shape of each aspherical lens can be defined by but not limited to the following aspherical surface formula:

Wherein, x is the distance vector height from the vertex of the aspheric surface when the aspheric surface is at a height of h along the extension direction of the optical axis; c is the paraxial curvature of the aspheric surface, c=1/R (i.e., the paraxial curvature c is the reciprocal of the curvature radius R in Table 1 above); k is the cone coefficient; Ai is the correction coefficient of the i-th order of the aspheric surface. Table 2 below gives the high-order coefficients A4, A6, A8, A10, A12, A14, A16, A18, A20, A22, A24, A26, A28, A30 that can be used for each aspheric mirror surface S1-S14 in Example 1.

Table 2

FIG. 2 shows the axial chromatic aberration curve of the optical imaging system of Example 1, which indicates the deviation of the convergence point of light rays of different wavelengths after passing through the optical imaging system. FIG. 3 shows the astigmatism curve of the optical imaging system of Example 1, which indicates the meridional image curvature and the sagittal image curvature. FIG. 4 shows the distortion curve of the optical imaging system of Example 1, which indicates the distortion magnitude values corresponding to different field angles. FIG. 5 shows the magnification chromatic aberration curve of the optical imaging system of Example 1, which indicates the deviation of different image heights on the imaging plane after the light rays pass through the optical imaging system.

It can be seen from FIG. 2 to FIG. 5 that the optical imaging system provided in Example 1 can achieve good imaging quality.

Example 2

As shown in Figures 6 to 10, an optical imaging system of Example 2 of the present application is described. Figure 1 shows a schematic diagram of the structure of the optical imaging system of Example 2. For the sake of brevity, some descriptions similar to Example 1 will be omitted.

As shown in FIG. 6 , the optical imaging system includes, from the object side to the image side, an aperture STO, a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a sixth lens E6, a seventh lens E7, a filter E8 and an imaging surface S17.

The first lens E1 has positive focal power, the object side surface S1 of the first lens is convex, and the image side surface S2 of the first lens is concave. The second lens E2 has negative focal power, the object side surface S3 of the second lens is convex, and the image side surface S4 of the second lens is concave. The third lens E3 has negative focal power, the object side surface S5 of the third lens is convex, and the image side surface S6 of the third lens is concave. The fourth lens E4 has positive focal power, the object side surface S7 of the fourth lens is convex, and the image side surface S8 of the fourth lens is concave. The fifth lens E5 has negative focal power, the object side surface S9 of the fifth lens is convex, and the image side surface S10 of the fifth lens is concave. The sixth lens E6 has positive focal power, the object side surface S11 of the sixth lens is convex, and the image side surface S12 of the sixth lens is concave. The seventh lens E7 has negative focal power, the object side surface S13 of the seventh lens is concave, and the image side surface S14 of the seventh lens is convex. The filter E8 has an object side surface S15 and an image side surface S16. Light from the object passes through the surfaces S1 to S16 in sequence and is finally imaged on the imaging surface S17.

In this example, the total effective focal length f of the optical imaging system is 5.58 mm, the maximum field of view FOV of the optical imaging system is 86.8°, the total length TTL of the optical imaging system is 6.50 mm, half of the diagonal length of the effective pixel area on the imaging plane of the optical imaging system ImgH is 5.53 mm, and the aperture value f/EPD of the optical imaging system is 1.86.

Table 3 shows a basic structural parameter table of the optical imaging system of Example 2, wherein the units of the radius of curvature and thickness/distance are all millimeters (mm).

Table 3

Table 4 gives the high-order coefficients that can be used for each aspherical mirror surface S1-S14 in Example 2. The surface shape of each aspherical surface can be defined by formula (1) given in Example 1.

Table 4

FIG. 7 shows the axial chromatic aberration curve of the optical imaging system of Example 2, which indicates the deviation of the convergence point of light rays of different wavelengths after passing through the optical imaging system. FIG. 8 shows the astigmatism curve of the optical imaging system of Example 2, which indicates the meridional image curvature and the sagittal image curvature. FIG. 9 shows the distortion curve of the optical imaging system of Example 2, which indicates the distortion magnitude values corresponding to different field angles. FIG. 10 shows the magnification chromatic aberration curve of the optical imaging system of Example 2, which indicates the deviation of different image heights on the imaging plane after the light rays pass through the optical imaging system.

It can be seen from FIG. 7 to FIG. 10 that the optical imaging system provided in Example 2 can achieve good imaging quality.

Example 3

As shown in Figures 11 to 15, an optical imaging system of Example 3 of the present application is described. Figure 11 shows a schematic structural diagram of the optical imaging system of Example 3.

As shown in FIG. 11 , the optical imaging system includes, from the object side to the image side, an aperture STO, a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a sixth lens E6, a seventh lens E7, a filter E8 and an imaging surface S17.

The first lens E1 has positive focal power, the object side surface S1 of the first lens is convex, and the image side surface S2 of the first lens is concave. The second lens E2 has negative focal power, the object side surface S3 of the second lens is convex, and the image side surface S4 of the second lens is concave. The third lens E3 has negative focal power, the object side surface S5 of the third lens is convex, and the image side surface S6 of the third lens is concave. The fourth lens E4 has positive focal power, the object side surface S7 of the fourth lens is convex, and the image side surface S8 of the fourth lens is concave. The fifth lens E5 has negative focal power, the object side surface S9 of the fifth lens is convex, and the image side surface S10 of the fifth lens is concave. The sixth lens E6 has positive focal power, the object side surface S11 of the sixth lens is convex, and the image side surface S12 of the sixth lens is concave. The seventh lens E7 has negative focal power, the object side surface S13 of the seventh lens is concave, and the image side surface S14 of the seventh lens is convex. The filter E8 has an object side surface S15 and an image side surface S16. Light from the object passes through the surfaces S1 to S16 in sequence and is finally imaged on the imaging surface S17.

In this example, the total effective focal length f of the optical imaging system is 5.30 mm, the maximum field of view FOV of the optical imaging system is 86.7°, the total length TTL of the optical imaging system is 6.20 mm, half of the diagonal length of the effective pixel area on the imaging plane of the optical imaging system ImgH is 5.27 mm, and the aperture value f/EPD of the optical imaging system is 1.84.

Table 5 shows a basic structural parameter table of the optical imaging system of Example 3, wherein the units of the radius of curvature and thickness/distance are all millimeters (mm).

Table 5

Table 6 gives the high-order coefficients that can be used for each aspherical mirror surface S1-S14 in Example 3. The surface shape of each aspherical surface can be defined by formula (1) given in Example 1.

Table 6

FIG12 shows the axial chromatic aberration curve of the optical imaging system of Example 3, which indicates the deviation of the convergence point of light rays of different wavelengths after passing through the optical imaging system. FIG13 shows the astigmatism curve of the optical imaging system of Example 3, which indicates the meridional image curvature and the sagittal image curvature. FIG14 shows the distortion curve of the optical imaging system of Example 3, which indicates the distortion magnitude values corresponding to different field angles. FIG15 shows the magnification chromatic aberration curve of the optical imaging system of Example 3, which indicates the deviation of different image heights on the imaging plane after the light rays pass through the optical imaging system.

It can be seen from FIG. 12 to FIG. 15 that the optical imaging system provided in Example 3 can achieve good imaging quality.

Example 4

As shown in Figures 16 to 20, an optical imaging system of Example 4 of the present application is described. Figure 16 shows a schematic structural diagram of the optical imaging system of Example 4.

As shown in FIG. 16 , the optical imaging system includes, from the object side to the image side, an aperture STO, a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a sixth lens E6, a seventh lens E7, a filter E8 and an imaging surface S17.

The first lens E1 has positive focal power, the object side surface S1 of the first lens is convex, and the image side surface S2 of the first lens is concave. The second lens E2 has negative focal power, the object side surface S3 of the second lens is convex, and the image side surface S4 of the second lens is concave. The third lens E3 has negative focal power, the object side surface S5 of the third lens is convex, and the image side surface S6 of the third lens is concave. The fourth lens E4 has positive focal power, the object side surface S7 of the fourth lens is convex, and the image side surface S8 of the fourth lens is concave. The fifth lens E5 has negative focal power, the object side surface S9 of the fifth lens is convex, and the image side surface S10 of the fifth lens is concave. The sixth lens E6 has positive focal power, the object side surface S11 of the sixth lens is convex, and the image side surface S12 of the sixth lens is concave. The seventh lens E7 has negative focal power, the object side surface S13 of the seventh lens is concave, and the image side surface S14 of the seventh lens is convex. The filter E8 has an object side surface S15 and an image side surface S16. Light from the object passes through the surfaces S1 to S16 in sequence and is finally imaged on the imaging surface S17.

In this example, the total effective focal length f of the optical imaging system is 5.31 mm, the maximum field of view FOV of the optical imaging system is 84.3°, the total length TTL of the optical imaging system is 6.20 mm, half of the diagonal length of the effective pixel area on the imaging plane of the optical imaging system ImgH is 5.64 mm, and the aperture value f/EPD of the optical imaging system is 1.76.

Table 7 shows a basic structural parameter table of the optical imaging system of Example 4, wherein the units of the radius of curvature and thickness/distance are all millimeters (mm).

Table 7

Table 8 gives the high-order coefficients that can be used for each aspherical mirror surface S1-S14 in Example 4. The surface shape of each aspherical surface can be defined by formula (1) given in Example 1.

Table 8

FIG17 shows the axial chromatic aberration curve of the optical imaging system of Example 4, which indicates the deviation of the convergence point of light rays of different wavelengths after passing through the optical imaging system. FIG18 shows the astigmatism curve of the optical imaging system of Example 4, which indicates the meridional image curvature and the sagittal image curvature. FIG19 shows the distortion curve of the optical imaging system of Example 4, which indicates the distortion magnitude values corresponding to different field angles. FIG20 shows the magnification chromatic aberration curve of the optical imaging system of Example 4, which indicates the deviation of different image heights on the imaging plane after the light rays pass through the optical imaging system.

It can be seen from FIG. 17 to FIG. 20 that the optical imaging system provided in Example 4 can achieve good imaging quality.

Example 5

As shown in Figures 21 to 25, an optical imaging system of Example 5 of the present application is described. Figure 21 shows a schematic structural diagram of the optical imaging system of Example 5.

As shown in FIG. 21 , the optical imaging system includes, from the object side to the image side, an aperture STO, a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a sixth lens E6, a seventh lens E7, a filter E8 and an imaging surface S17.

The first lens E1 has positive focal power, the object side surface S1 of the first lens is convex, and the image side surface S2 of the first lens is concave. The second lens E2 has negative focal power, the object side surface S3 of the second lens is convex, and the image side surface S4 of the second lens is concave. The third lens E3 has negative focal power, the object side surface S5 of the third lens is convex, and the image side surface S6 of the third lens is concave. The fourth lens E4 has positive focal power, the object side surface S7 of the fourth lens is convex, and the image side surface S8 of the fourth lens is concave. The fifth lens E5 has negative focal power, the object side surface S9 of the fifth lens is convex, and the image side surface S10 of the fifth lens is concave. The sixth lens E6 has positive focal power, the object side surface S11 of the sixth lens is convex, and the image side surface S12 of the sixth lens is concave. The seventh lens E7 has negative focal power, the object side surface S13 of the seventh lens is concave, and the image side surface S14 of the seventh lens is convex. The filter E8 has an object side surface S15 and an image side surface S16. Light from the object passes through the surfaces S1 to S16 in sequence and is finally imaged on the imaging surface S17.

In this example, the total effective focal length f of the optical imaging system is 5.18 mm, the maximum field of view FOV of the optical imaging system is 84.0°, the total length TTL of the optical imaging system is 6.11 mm, half of the diagonal length of the effective pixel area on the imaging plane of the optical imaging system ImgH is 5.27 mm, and the aperture value f/EPD of the optical imaging system is 1.74.

Table 9 shows the basic structural parameter table of the optical imaging system of Example 5, wherein the units of the radius of curvature and thickness/distance are all millimeters (mm).

Table 9

Table 10 gives the high-order coefficients that can be used for each aspherical mirror surface S1-S14 in Example 5. The surface shape of each aspherical surface can be defined by formula (1) given in Example 1.

Table 10

FIG22 shows the axial chromatic aberration curve of the optical imaging system of Example 5, which indicates the deviation of the convergence point of light rays of different wavelengths after passing through the optical imaging system. FIG23 shows the astigmatism curve of the optical imaging system of Example 5, which indicates the meridional image curvature and the sagittal image curvature. FIG24 shows the distortion curve of the optical imaging system of Example 5, which indicates the distortion magnitude values corresponding to different field angles. FIG25 shows the magnification chromatic aberration curve of the optical imaging system of Example 5, which indicates the deviation of different image heights on the imaging plane after the light rays pass through the optical imaging system.

It can be seen from FIG. 22 to FIG. 25 that the optical imaging system provided in Example 5 can achieve good imaging quality.

Example 6

As shown in Figures 26 to 30, an optical imaging system of Example 6 of the present application is described. Figure 26 shows a schematic structural diagram of the optical imaging system of Example 6.

As shown in FIG. 26 , the optical imaging system includes, from the object side to the image side, an aperture STO, a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a sixth lens E6, a seventh lens E7, a filter E8 and an imaging surface S17.

The first lens E1 has positive focal power, the object side surface S1 of the first lens is convex, and the image side surface S2 of the first lens is concave. The second lens E2 has negative focal power, the object side surface S3 of the second lens is convex, and the image side surface S4 of the second lens is concave. The third lens E3 has negative focal power, the object side surface S5 of the third lens is convex, and the image side surface S6 of the third lens is concave. The fourth lens E4 has positive focal power, the object side surface S7 of the fourth lens is convex, and the image side surface S8 of the fourth lens is convex. The fifth lens E5 has negative focal power, the object side surface S9 of the fifth lens is convex, and the image side surface S10 of the fifth lens is concave. The sixth lens E6 has positive focal power, the object side surface S11 of the sixth lens is convex, and the image side surface S12 of the sixth lens is concave. The seventh lens E7 has negative focal power, the object side surface S13 of the seventh lens is concave, and the image side surface S14 of the seventh lens is convex. The filter E8 has an object side surface S15 and an image side surface S16. Light from the object passes through the surfaces S1 to S16 in sequence and is finally imaged on the imaging surface S17.

In this example, the total effective focal length f of the optical imaging system is 5.56 mm, the maximum field of view FOV of the optical imaging system is 87.2°, the total length TTL of the optical imaging system is 6.49 mm, half of the diagonal length of the effective pixel area on the imaging plane of the optical imaging system ImgH is 5.53 mm, and the aperture value f/EPD of the optical imaging system is 1.86.

Table 11 shows the basic structural parameter table of the optical imaging system of Example 6, wherein the units of the radius of curvature and thickness/distance are all millimeters (mm).

Table 11

Table 12 gives the high-order coefficients that can be used for each aspherical mirror surface S1-S14 in Example 6. The surface shape of each aspherical surface can be defined by formula (1) given in Example 1.

Table 12

FIG27 shows the axial chromatic aberration curve of the optical imaging system of Example 6, which indicates the deviation of the convergence point of light rays of different wavelengths after passing through the optical imaging system. FIG28 shows the astigmatism curve of the optical imaging system of Example 6, which indicates the meridional image curvature and the sagittal image curvature. FIG29 shows the distortion curve of the optical imaging system of Example 6, which indicates the distortion magnitude values corresponding to different field angles. FIG30 shows the magnification chromatic aberration curve of the optical imaging system of Example 6, which indicates the deviation of different image heights on the imaging plane after the light rays pass through the optical imaging system.

It can be seen from FIG. 27 to FIG. 30 that the optical imaging system provided in Example 6 can achieve good imaging quality.

Example 7

As shown in Figures 31 to 35, an optical imaging system of Example 7 of the present application is described. Figure 31 shows a schematic diagram of the structure of the optical imaging system of Example 7.

As shown in FIG. 31 , the optical imaging system includes, from the object side to the image side, an aperture STO, a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a sixth lens E6, a seventh lens E7, a filter E8 and an imaging surface S17.

The first lens E1 has positive focal power, the object side surface S1 of the first lens is convex, and the image side surface S2 of the first lens is concave. The second lens E2 has negative focal power, the object side surface S3 of the second lens is convex, and the image side surface S4 of the second lens is concave. The third lens E3 has negative focal power, the object side surface S5 of the third lens is concave, and the image side surface S6 of the third lens is concave. The fourth lens E4 has positive focal power, the object side surface S7 of the fourth lens is convex, and the image side surface S8 of the fourth lens is concave. The fifth lens E5 has negative focal power, the object side surface S9 of the fifth lens is convex, and the image side surface S10 of the fifth lens is concave. The sixth lens E6 has positive focal power, the object side surface S11 of the sixth lens is convex, and the image side surface S12 of the sixth lens is concave. The seventh lens E7 has negative focal power, the object side surface S13 of the seventh lens is concave, and the image side surface S14 of the seventh lens is convex. The filter E8 has an object side surface S15 and an image side surface S16. Light from the object passes through the surfaces S1 to S16 in sequence and is finally imaged on the imaging surface S17.

In this example, the total effective focal length f of the optical imaging system is 5.30 mm, the maximum field of view FOV of the optical imaging system is 84.96°, the total length TTL of the optical imaging system is 6.21 mm, half of the diagonal length of the effective pixel area on the imaging plane of the optical imaging system ImgH is 5.27 mm, and the aperture value f/EPD of the optical imaging system is 1.84.

Table 13 shows the basic structural parameter table of the optical imaging system of Example 7, wherein the units of the radius of curvature and thickness/distance are all millimeters (mm).

Table 13

Table 14 gives the high-order coefficients that can be used for each aspheric mirror surface S1-S14 in Example 7. The surface shape of each aspheric surface can be defined by formula (1) given in Example 1.

Face number A4 A6 A8 A10 A12 A14 A16 S1 -1.7187E-02 -4.9129E-03 -2.2851E-03 -7.2628E-04 -2.2210E-04 -1.7180E-05 -9.3287E-06 S2 -5.0364E-02 7.6862E-03 -1.6605E-03 6.9181E-04 5.8685E-05 -3.9429E-05 -2.2969E-05 S3 1.2328E-02 1.6201E-02 8.1266E-04 1.5233E-03 1.6708E-04 -5.4304E-06 -2.5361E-05 S4 4.6584E-02 8.1526E-03 1.1767E-03 1.0085E-03 3.7103E-04 1.4601E-04 6.9252E-05 S5 -9.9493E-02 -7.3343E-03 3.8041E-07 7.8722E-04 3.9538E-04 1.5940E-04 7.7821E-05 S6 1.1243E-02 5.8775E-02 -2.6317E-02 8.4884E-03 -1.9476E-03 1.1515E-03 -7.3265E-04 S7 -1.9770E-01 3.6940E-02 6.3314E-03 -1.1614E-04 -1.4696E-03 -1.3039E-04 9.7190E-05 S8 -2.5532E-01 3.2458E-02 1.2523E-02 2.6635E-03 -1.1831E-03 -5.0077E-04 -2.2853E-04 S9 -7.7767E-01 3.6765E-03 6.7109E-03 2.9501E-02 3.2786E-04 9.4382E-05 -2.2081E-03 S10 -2.5250E+00 4.7857E-01 -1.1956E-01 4.7521E-02 -3.0554E-02 9.6441E-03 -1.6218E-03 S11 -4.7048E+00 1.0309E+00 -1.7262E-01 2.2454E-03 -7.0827E-03 1.5061E-02 -1.4562E-02 S12 -1.1650E+00 -1.1945E-01 1.8813E-01 -8.5069E-02 4.5461E-02 -1.3164E-02 2.8302E-03 S13 -1.2041E+00 -2.3428E-01 -2.0278E-01 -1.3129E-01 -5.3753E-02 -2.3371E-02 4.8369E-02 S14 -6.3356E-01 8.1979E-02 5.8768E-02 -1.7253E-02 -5.1915E-03 8.0606E-05 2.3751E-04 Face number A18 A20 A22 A24 A26 A28 A30 S1 1.1536E-05 -4.8272E-06 4.4854E-07 -2.9069E-06 1.6223E-06 -5.3189E-06 0.0000E+00 S2 -2.1096E-05 -1.1592E-07 -2.4638E-07 3.7628E-06 9.2720E-07 2.8829E-06 0.0000E+00 S3 -2.0010E-05 -1.0380E-05 -5.9592E-06 -8.2612E-06 -4.4128E-06 -3.9060E-06 0.0000E+00 S4 1.8550E-05 6.7811E-06 -6.5151E-06 -5.3039E-06 -3.9075E-06 1.4881E-06 0.0000E+00 S5 3.0671E-05 1.6291E-05 5.5790E-06 8.8054E-09 -1.2000E-07 -2.7209E-06 0.0000E+00 S6 2.9573E-04 -1.5909E-05 -1.1172E-04 1.2716E-04 -8.0065E-05 3.7692E-05 0.0000E+00 S7 1.1190E-04 -2.1617E-05 1.6615E-06 -1.0073E-05 8.5907E-06 -2.0369E-06 0.0000E+00 S8 7.3697E-05 1.4290E-05 2.9363E-05 -6.0338E-06 -2.0318E-06 -2.2787E-06 0.0000E+00 S9 -3.6216E-05 -1.3071E-04 1.2185E-04 -1.8395E-05 -1.3412E-05 -1.5650E-05 1.1667E-05 S10 2.2869E-03 -1.3449E-03 2.4788E-04 -1.4435E-04 4.7335E-05 -3.7368E-05 5.1152E-06 S11 8.8639E-03 -2.1175E-03 -3.5224E-04 6.7242E-05 5.4005E-04 -3.4554E-04 -1.4060E-05 S12 -5.1716E-03 9.4580E-04 -3.4134E-04 7.7004E-04 -3.0681E-04 4.5114E-04 -1.0310E-04 S13 4.2081E-02 7.6558E-03 -1.5533E-03 -8.5339E-03 -6.8745E-03 -1.5648E-03 -2.9325E-04 S14 2.1348E-03 -1.6879E-03 -1.2614E-03 1.6058E-03 -8.5665E-04 3.0021E-04 -6.0953E-05

Table 14

FIG32 shows the axial chromatic aberration curve of the optical imaging system of Example 7, which indicates the deviation of the convergence point of light rays of different wavelengths after passing through the optical imaging system. FIG33 shows the astigmatism curve of the optical imaging system of Example 7, which indicates the meridional image curvature and the sagittal image curvature. FIG34 shows the distortion curve of the optical imaging system of Example 7, which indicates the distortion magnitude values corresponding to different field angles. FIG35 shows the magnification chromatic aberration curve of the optical imaging system of Example 7, which indicates the deviation of different image heights on the imaging plane after the light rays pass through the optical imaging system.

It can be seen from Figures 32 to 35 that the optical imaging system provided in Example 7 can achieve good imaging quality.

Example 8

As shown in Figures 36 to 40, an optical imaging system of Example 8 of the present application is described. Figure 36 shows a schematic structural diagram of the optical imaging system of Example 8.

As shown in FIG. 36 , the optical imaging system includes, from the object side to the image side, an aperture STO, a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a sixth lens E6, a seventh lens E7, a filter E8 and an imaging surface S17.

The first lens E1 has positive focal power, the object side surface S1 of the first lens is convex, and the image side surface S2 of the first lens is concave. The second lens E2 has negative focal power, the object side surface S3 of the second lens is convex, and the image side surface S4 of the second lens is concave. The third lens E3 has negative focal power, the object side surface S5 of the third lens is convex, and the image side surface S6 of the third lens is concave. The fourth lens E4 has positive focal power, the object side surface S7 of the fourth lens is convex, and the image side surface S8 of the fourth lens is convex. The fifth lens E5 has negative focal power, the object side surface S9 of the fifth lens is convex, and the image side surface S10 of the fifth lens is concave. The sixth lens E6 has positive focal power, the object side surface S11 of the sixth lens is convex, and the image side surface S12 of the sixth lens is concave. The seventh lens E7 has negative focal power, the object side surface S13 of the seventh lens is concave, and the image side surface S14 of the seventh lens is convex. The filter E8 has an object side surface S15 and an image side surface S16. Light from the object passes through the surfaces S1 to S16 in sequence and is finally imaged on the imaging surface S17.

In this example, the total effective focal length f of the optical imaging system is 5.17 mm, the maximum field of view FOV of the optical imaging system is 85.55°, the total length TTL of the optical imaging system is 6.20 mm, half of the diagonal length of the effective pixel area on the imaging plane of the optical imaging system ImgH is 5.59 mm, and the aperture value f/EPD of the optical imaging system is 1.80.

Table 15 shows the basic structural parameter table of the optical imaging system of Example 8, wherein the units of the radius of curvature and thickness/distance are all millimeters (mm).

Table 16 gives the high-order coefficients that can be used for each aspheric mirror surface S1-S14 in Example 8. The surface shape of each aspheric surface can be defined by formula (1) given in Example 1.

Face number A4 A6 A8 A10 A12 A14 A16 S1 -2.4669E-02 -1.5595E-03 -1.8023E-03 -6.1702E-05 -2.6727E-04 1.0234E-04 -8.8761E-05 S2 -4.3739E-02 1.1132E-02 -4.5998E-03 1.1408E-03 -1.7590E-04 4.3486E-05 4.2375E-05 S3 1.1846E-02 1.2420E-02 -3.7039E-03 1.4477E-03 -1.1659E-04 1.6203E-05 5.5357E-05 S4 4.2187E-02 7.3994E-03 -1.0168E-03 3.5331E-04 2.1451E-05 -5.2952E-06 3.7607E-05 S5 -8.8894E-02 -5.7664E-03 -7.3152E-04 -5.0295E-06 -2.6646E-05 2.3700E-05 -1.7345E-05 S6 -1.3946E-01 7.8256E-03 2.9629E-03 1.5609E-03 1.4664E-04 1.1876E-04 3.3641E-05 S7 -2.1111E-01 4.1920E-02 5.9469E-03 -6.7260E-04 -1.3059E-03 4.2972E-05 1.5921E-04 S8 -2.6828E-01 3.2823E-02 1.0986E-02 2.3877E-03 -6.8047E-04 -1.7892E-04 4.7143E-05 S9 -6.9640E-01 -1.6576E-02 -1.2690E-02 2.1862E-02 1.9760E-03 1.7183E-03 -7.7813E-04 S10 -2.2327E+00 4.0656E-01 -1.0371E-01 4.7834E-02 -2.1984E-02 4.4210E-03 -1.5083E-03 S11 -4.0225E+00 7.4088E-01 -8.2443E-02 8.5526E-03 -1.8053E-02 1.7314E-02 -1.1098E-02 S12 -9.1718E-01 -2.0531E-01 1.6843E-01 -7.8592E-02 3.4675E-02 -5.5097E-03 3.5678E-03 S13 3.1800E+00 -4.9651E-01 1.1346E-01 -7.5979E-03 -2.0720E-02 2.0845E-02 -8.7235E-03 S14 -4.2034E-01 4.4062E-02 5.3226E-02 -1.0027E-02 -6.0944E-03 1.5306E-03 -1.4627E-03 Face number A18 A20 A22 A24 A26 A28 A30 S1 5.7094E-05 -3.1636E-05 2.7441E-05 2.6942E-06 1.9102E-05 -2.1549E-05 0.0000E+00 S2 -5.3381E-05 2.4179E-06 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S3 -2.5769E-05 3.8838E-05 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S4 -2.6420E-05 2.4318E-06 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S5 -1.9916E-06 -1.7498E-05 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S6 1.7513E-05 -1.1393E-06 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S7 -2.6676E-05 -1.6231E-05 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S8 -2.2575E-05 -4.9548E-05 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S9 1.7074E-04 -1.8573E-04 -3.7989E-05 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S10 1.5383E-03 -8.6769E-04 2.3330E-04 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S11 3.1116E-03 9.5328E-05 3.0285E-04 -9.8927E-04 4.7101E-04 9.4890E-06 -3.8176E-05 S12 -2.2307E-03 8.4238E-04 -5.4528E-04 -2.3487E-04 -2.6324E-04 -1.1278E-04 1.6813E-04 S13 -1.0846E-03 4.2194E-03 -3.5422E-03 1.6395E-03 -1.0630E-04 -2.3310E-04 6.1535E-05 S14 1.5963E-03 -1.4324E-05 -1.2555E-03 1.1911E-03 -7.6378E-04 3.0696E-05 7.8379E-05

Table 16

Figure 37 shows the axial chromatic aberration curve of the optical imaging system of Example 8, which indicates the deviation of the convergence point of light rays of different wavelengths after passing through the optical imaging system. Figure 38 shows the astigmatism curve of the optical imaging system of Example 8, which indicates the meridional image curvature and sagittal image curvature. Figure 39 shows the distortion curve of the optical imaging system of Example 8, which indicates the distortion magnitude values corresponding to different field angles. Figure 40 shows the magnification chromatic aberration curve of the optical imaging system of Example 8, which indicates the deviation of different image heights on the imaging plane after the light rays pass through the optical imaging system.

It can be seen from Figures 37 to 40 that the optical imaging system provided in Example 8 can achieve good imaging quality.

In summary, Examples 1 to 8 respectively satisfy the relationships shown in Table 17.

Conditional/Example 1 2 3 4 5 6 7 8 TTL/ImgH 1.18 1.17 1.18 1.10 1.16 1.17 1.18 1.11 f7/R13 2.18 2.16 2.15 2.14 2.10 2.16 2.15 2.19 (V6+V7)/2/(f6-f7) 8.41 8.02 8.43 7.94 8.56 8.02 8.42 7.94 R14/R13 6.76 7.19 7.29 7.52 8.47 7.19 7.32 6.69 f*tan(FOV/2) 5.15 5.28 5.00 4.81 4.66 5.29 4.85 4.79 f1/(DT11+DT12)+f2/(DT21+DT22) -4.41 -3.71 -3.50 -2.99 -2.69 -3.65 -3.88 -3.30 T67/∑AT 0.40 0.40 0.40 0.41 0.40 0.40 0.39 0.42 (R11/f6)/(R13/f7) 1.06 1.05 1.04 1.04 1.02 1.05 1.04 1.07 R2/(N1-1)/[R4/(N2-1)]+R4/(N2-1)/[R6/(N3-1)] 1.89 2.19 2.29 3.13 3.03 2.05 2.24 2.81 [V1/(CT1+T12)-V2/(CT2+T23)-V3/(CT3+T34)]/3 -3.40 -3.36 -3.66 -4.04 -2.89 -3.36 -2.22 -3.05 1/(SAG11/f1-SAG41/f4-SAG61/f6) 4.14 4.01 3.97 4.13 3.80 4.01 3.83 4.52 (f3+f4)/(f3-f4) 0.32 0.30 0.31 0.66 0.47 0.68 0.22 0.76 f123/(R1+R3+R5)-f45/(R7+R9) 0.53 0.52 0.50 0.43 0.42 0.28 0.25 0.38 T45/(ET4+ET5)+T45/(CT4+CT5) 1.88 1.85 1.84 2.02 1.78 1.85 1.83 1.92 |f6/f7| 0.71 0.71 0.71 0.71 0.73 0.71 0.71 0.69 |f6/f5| 0.56 0.56 0.57 0.60 0.58 0.56 0.58 0.59 |f6/f4| 0.11 0.11 0.11 0.11 0.11 0.07 0.11 0.11 f67/f6-f67/f7 2.82 2.85 2.86 2.85 2.95 2.85 2.84 2.75 DT72/DT71 1.04 1.05 1.05 1.08 1.08 1.05 1.06 1.11 (R12+R11)/CT6-(R12-R11)/(T56+CT6) 9.99 9.85 9.79 8.56 9.60 9.86 9.47 8.41 EPD/(R2-R1)+EPD/(DT11+DT12) 1.65 1.56 1.54 1.44 1.41 1.55 1.53 1.48

Table 17

Table 18 gives the effective focal length f of the optical imaging systems of Examples 1 to 8, and the effective focal lengths f1 to f7 of each lens.

Basic data/examples 1 2 3 4 5 6 7 8 f1(mm) 5.06 5.11 4.81 4.90 4.55 5.10 4.78 4.94 f2(mm) -15.58 -14.45 -13.21 -12.49 -11.20 -14.22 -14.22 -13.06 f3(mm) -49.47 -49.64 -48.87 -126.96 -70.12 -213.68 -37.82 -195.94 f4(mm) 25.74 26.61 25.52 26.31 25.42 40.50 24.07 26.42 f5(mm) -4.91 -5.15 -4.89 -4.93 -4.78 -5.15 -4.77 -4.95 f6(mm) 2.76 2.91 2.77 2.94 2.77 2.91 2.76 2.90 f7(mm) -3.91 -4.09 -3.88 -4.13 -3.79 -4.08 -3.90 -4.17 f(mm) 5.34 5.58 5.30 5.31 5.18 5.56 5.30 5.17 TTL(mm) 6.20 6.50 6.20 6.20 6.11 6.49 6.21 6.20 ImgH(mm) 5.27 5.53 5.27 5.64 5.27 5.53 5.27 5.59 FOV(°) 88.0 86.8 86.7 84.3 84.0 87.2 84.96 85.55 f/EPD 1.88 1.86 1.84 1.76 1.74 1.86 1.84 1.80

Table 18

The present application also provides an imaging device, whose electronic photosensitive element can be a photosensitive coupled device (CCD) or a complementary metal oxide semiconductor element (CMOS). The imaging device can be an independent imaging device such as a digital camera, or an imaging module integrated in a mobile electronic device such as a mobile phone. The imaging device is equipped with the optical imaging system described above.

Obviously, the embodiments described above are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and/or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and/or combinations thereof.

It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims (10)

1. An optical imaging system, characterized in that the optical imaging system has only seven lenses, and the optical imaging system includes, from the object side to the image side, the following lenses: A first lens, wherein the focal length of the first lens is positive; a second lens, wherein the focal length of the second lens is negative; A third lens, wherein the focal length of the third lens is negative; a fourth lens having a positive focal length; a fifth lens having a negative focal length; a sixth lens having a positive focal length; a seventh lens, wherein the focal length of the seventh lens is negative, and the radius of curvature of the object side surface of the seventh lens and the radius of curvature of the image side surface of the seventh lens are less than zero; A curvature radius R13 of the object side surface of the seventh lens and a curvature radius R14 of the image side surface of the seventh lens satisfy: 0<R14/R13<10; The distance TTL from the object side of the first lens to the imaging surface of the optical imaging system on the optical axis of the optical imaging system and half the diagonal length of the effective pixel area on the imaging surface ImgH satisfy the following: TTL/ImgH<1.3; The effective focal length f7 of the seventh lens and the curvature radius R13 of the object side surface of the seventh lens satisfy the following: 2.0<f7/R13<2.5; The dispersion coefficient V6 of the sixth lens, the dispersion coefficient V7 of the seventh lens, the effective focal length f6 of the sixth lens, and the effective focal length f7 of the seventh lens satisfy the following: 7.5<(V6+V7)/2/(f6-f7)<9.0. 2. The optical imaging system according to claim 1 is characterized in that the effective focal length f of the optical imaging system and the maximum field of view FOV of the optical imaging system satisfy: f*tan(FOV/2)>4.5. 3. The optical imaging system according to claim 1 is characterized in that the effective focal length f1 of the first lens, the maximum effective radius DT11 of the object side surface of the first lens, the maximum effective radius DT12 of the image side surface of the first lens, the effective focal length f2 of the second lens, the maximum effective radius DT21 of the object side surface of the second lens, and the maximum effective radius DT22 of the image side surface of the second lens satisfy the following relationship: -5.0<f1/(DT11+DT12)+f2/(DT21+DT22)<-2.0. 4. The optical imaging system according to claim 1, characterized in that an air interval T67 between the sixth lens and the seventh lens on the optical axis satisfies: T67>Tij, wherein Tij is the air interval between the i-th lens to the j-th lens on the optical axis, i is 1, 2, 3, 4, 5, j=i+1, and the air interval T67 between the sixth lens and the seventh lens on the optical axis and the sum ∑AT of the air intervals between two adjacent lenses in the optical imaging system on the optical axis satisfy: T67/∑AT<0.5. 5. The optical imaging system according to claim 1 is characterized in that a curvature radius R11 of the object side surface of the sixth lens is less than 1.5, a curvature radius of the object side surface of the sixth lens is smaller than a curvature radius of the object side surface of the seventh lens, and an effective focal length f6 of the sixth lens, an effective focal length f7 of the seventh lens, a curvature radius R11 of the object side surface of the sixth lens, and a curvature radius R13 of the object side surface of the seventh lens satisfy: 0<(R11/f6)/(R13/f7)<1.5. 6. The optical imaging system according to claim 1 is characterized in that the radius of curvature R2 of the image side surface of the first lens, the refractive index N1 of the first lens, the radius of curvature R4 of the image side surface of the second lens, the refractive index N2 of the second lens, the radius of curvature R6 of the image side surface of the third lens, and the refractive index N3 of the third lens satisfy: 0<R2/(N1-1)/[R4/(N2-1)]+R4/(N2-1)/[R6/(N3-1)]<4.0. 7. The optical imaging system according to claim 1, characterized in that the dispersion coefficient V1 of the first lens, the center thickness CT1 of the first lens, the air interval T12 between the first lens and the second lens on the optical axis, the dispersion coefficient V2 of the second lens, the center thickness CT2 of the second lens, the air interval T23 between the second lens and the third lens on the optical axis, the dispersion coefficient V3 of the third lens, the center thickness CT3 of the third lens, and the air interval T34 between the third lens and the fourth lens on the optical axis satisfy the following conditions: -5.0<[V1/(CT1+T12)-V2/(CT2+T23)-V3/(CT3+T34)]/3<0. 8. The optical imaging system according to any one of claims 1 to 7 is characterized in that the on-axis distance SAG11 between the intersection of the object side surface of the first lens and the optical axis to the effective radius vertex of the object side surface of the first lens, the effective focal length f1 of the first lens, the on-axis distance SAG41 between the intersection of the object side surface of the fourth lens and the optical axis to the effective radius vertex of the object side surface of the fourth lens, the effective focal length f4 of the fourth lens, the on-axis distance SAG61 between the intersection of the object side surface of the sixth lens and the optical axis to the effective radius vertex of the object side surface of the sixth lens, and the effective focal length f6 of the sixth lens satisfy the following: 2.0<1/(SAG11/f1-SAG41/f4-SAG61/f6)<5.0. 9. The optical imaging system according to any one of claims 1 to 7, characterized in that the effective focal length f3 of the third lens and the effective focal length f4 of the fourth lens satisfy: 0<(f3+f4)/(f3-f4)<1.0. 10. An optical imaging system, characterized in that the optical imaging system has only seven lenses, and the optical imaging system includes, from the object side to the image side, the following lenses: A first lens, wherein the focal length of the first lens is positive; a second lens, wherein the focal length of the second lens is negative; A third lens, wherein the focal length of the third lens is negative; a fourth lens having a positive focal length; a fifth lens having a negative focal length; a sixth lens having a positive focal length; a seventh lens, wherein the focal length of the seventh lens is negative, and the radius of curvature of the object side surface of the seventh lens and the radius of curvature of the image side surface of the seventh lens are less than zero; The distance TTL from the object side of the first lens to the imaging surface of the optical imaging system on the optical axis of the optical imaging system and the half of the diagonal length of the effective pixel area on the imaging surface ImgH satisfy the following: TTL/ImgH<1.3; The dispersion coefficient V6 of the sixth lens, the dispersion coefficient V7 of the seventh lens, the effective focal length f6 of the sixth lens, and the effective focal length f7 of the seventh lens satisfy the following: 7.5<(V6+V7)/2/(f6-f7)<9.0; The dispersion coefficient V1 of the first lens, the center thickness CT1 of the first lens, the air gap T12 between the first lens and the second lens on the optical axis, the dispersion coefficient V2 of the second lens, the center thickness CT2 of the second lens, the air gap T23 between the second lens and the third lens on the optical axis, the dispersion coefficient V3 of the third lens, the center thickness CT3 of the third lens, and the air gap T34 between the third lens and the fourth lens on the optical axis satisfy the following: -5.0<[V1/(CT1+T12)-V2/(CT2+T23)-V3/(CT3+T34)]/3<0.

Images