CN112415716A

CN112415716A - Optical imaging system

Info

Publication number: CN112415716A
Application number: CN202011405883.6A
Authority: CN
Inventors: 杨泉锋; 袁莹辉; 戴付建; 赵烈烽
Original assignee: Zhejiang Sunny Optics Co Ltd
Current assignee: Zhejiang Sunny Optics Co Ltd
Priority date: 2020-12-04
Filing date: 2020-12-04
Publication date: 2021-02-26

Abstract

The application discloses an optical imaging system, which comprises in order from an object side to an image side along an optical axis: a first lens having a positive optical power; a second lens having a negative optical power; a diaphragm; a third lens having optical power; the image side surface of the fourth lens is a convex surface; a fifth lens having optical power; a sixth lens having a refractive power, an object side surface of which is concave; and a seventh lens having optical power. 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 and the half ImgH of the diagonal length of the effective pixel area on the imaging surface of the optical imaging system satisfy that: TTL/ImgH is more than 1.0 and less than 1.3.

Description

Optical imaging system

Technical Field

The present application relates to the field of optical elements, and in particular, to an optical imaging system.

Background

With the development of society, portable electronic products such as smart phones and tablet computers have become indispensable tools in people's lives. Portable electronic products such as smart phones and tablet computers in the current market gradually tend to be miniaturized, so that an optical imaging system applied to the portable electronic products needs to meet the requirements of miniaturization, lightness and thinness and the like as far as possible while ensuring the imaging quality, and the design difficulty of the optical imaging system is undoubtedly increased. In addition, as the performance of the image sensor is improved and the size of the image sensor is reduced, the degree of freedom of design of the corresponding optical imaging system is reduced, and the difficulty of design of the optical imaging system is further increased.

How to reasonably set technical parameters such as focal power and surface type of each lens in the optical imaging system so that the optical imaging system has the characteristics of miniaturization, lightness and thinness and the like on the basis of higher imaging quality and can better match with an image sensor is one of the problems to be solved by many lens designers at present.

Disclosure of Invention

An aspect of the present application provides an optical imaging system, in order from an object side to an image side along an optical axis, comprising: a first lens having a positive optical power; a second lens having a negative optical power; a diaphragm; a third lens having optical power; the image side surface of the fourth lens is a convex surface; a fifth lens having optical power; a sixth lens having a refractive power, an object side surface of which is concave; and a seventh lens having optical power. 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 and the half of the diagonal length ImgH of the effective pixel area on the imaging surface of the optical imaging system can satisfy the following conditions: TTL/ImgH is more than 1.0 and less than 1.3.

In one embodiment, the object-side surface of the first lens element to the image-side surface of the seventh lens element has at least one aspherical mirror surface.

In one embodiment, the total effective focal length f of the optical imaging system and the radius of curvature R9 of the object side surface of the fifth lens may satisfy: r9/f is more than 0.5 and less than 1.2.

In one embodiment, the effective focal length f2 of the second lens and the effective focal length f1 of the first lens may satisfy: -4.5 < f2/f1 < -2.0.

In one embodiment, the total effective focal length f of the optical imaging system and the effective focal length f7 of the seventh lens may satisfy: -1.5 < f/f7 < -1.0.

In one embodiment, the radius of curvature R1 of the object-side surface of the first lens and the radius of curvature R2 of the image-side surface of the first lens may satisfy: 4.0 < R2/R1 < 6.0.

In one embodiment, the effective focal length f5 of the fifth lens and the radius of curvature R9 of the object side surface of the fifth lens may satisfy: f5/R9 is more than 1.0 and less than 1.5.

In one embodiment, the effective focal length f4 of the fourth lens and the radius of curvature R7 of the object side of the fourth lens may satisfy: 2.0 < f4/R7 < 4.0.

In one embodiment, the radius of curvature R10 of the image-side surface of the fifth lens and the radius of curvature R12 of the image-side surface of the sixth lens may satisfy: 0.5 < R10/R12 < 1.5.

In one embodiment, the radius of curvature R11 of the object-side surface of the sixth lens and the radius of curvature R14 of the image-side surface of the seventh lens may satisfy: 11.7 < R11/R14 < -7.7.

In one embodiment, a separation distance T56 between the fifth lens and the sixth lens on the optical axis and a separation distance T67 between the sixth lens and the seventh lens on the optical axis may satisfy: 4.7 < T67/T56 < 10.3.

In one embodiment, the relative F-number Fno of the optical imaging system may satisfy: fno is less than or equal to 1.9.

In one embodiment, half of the maximum field angle Semi-FOV of the optical imaging system may satisfy: 40 < Semi-FOV < 45.

Another aspect of the present application provides an optical imaging system, in order from an object side to an image side along an optical axis, comprising: a first lens having a positive optical power; a second lens having a negative optical power; a diaphragm; a third lens having optical power; the image side surface of the fourth lens is a convex surface; a fifth lens having optical power; a sixth lens having a refractive power, an object side surface of which is concave; and a seventh lens having optical power. The total effective focal length f of the optical imaging system and the curvature radius R9 of the object side surface of the fifth lens can satisfy the following conditions: r9/f is more than 0.5 and less than 1.2.

In one embodiment, a distance TTL between an object side surface of the first lens and an imaging surface of the optical imaging system on an optical axis and a half ImgH of a diagonal length of an effective pixel area on the imaging surface of the optical imaging system may satisfy: TTL/ImgH is more than 1.0 and less than 1.3.

The optical imaging system is applicable to portable electronic products, and has light weight, thinness, miniaturization and good imaging quality.

Drawings

Other features, objects and advantages of the present application will become more apparent upon reading of the following detailed description of non-limiting embodiments thereof, made with reference to the accompanying drawings in which:

fig. 1 shows a schematic configuration diagram of an optical imaging system according to embodiment 1 of the present application;

fig. 2A to 2C show an on-axis chromatic aberration curve, an astigmatism curve, and a distortion curve, respectively, of the optical imaging system of embodiment 1;

fig. 3 shows a schematic configuration diagram of an optical imaging system according to embodiment 2 of the present application;

fig. 4A to 4C show an on-axis chromatic aberration curve, an astigmatism curve, and a distortion curve, respectively, of the optical imaging system of embodiment 2;

fig. 5 shows a schematic configuration diagram of an optical imaging system according to embodiment 3 of the present application;

fig. 6A to 6C show an on-axis chromatic aberration curve, an astigmatism curve, and a distortion curve, respectively, of the optical imaging system of embodiment 3;

fig. 7 shows a schematic configuration diagram of an optical imaging system according to embodiment 4 of the present application;

fig. 8A to 8C show an on-axis chromatic aberration curve, an astigmatism curve, and a distortion curve, respectively, of the optical imaging system of embodiment 4;

fig. 9 shows a schematic configuration diagram of an optical imaging system according to embodiment 5 of the present application; and

fig. 10A to 10C show an on-axis chromatic aberration curve, an astigmatism curve, and a distortion curve, respectively, of the optical imaging system of embodiment 5.

Detailed Description

For a better understanding of the present application, various aspects of the present application will be described in more detail with reference to the accompanying drawings. It should be understood that the detailed description is merely illustrative of exemplary embodiments of the present application and does not limit the scope of the present application in any way. Like reference numerals refer to like elements throughout the specification. The expression "and/or" includes any and all combinations of one or more of the associated listed items.

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

In the drawings, the thickness, size, and shape of the lens have been slightly exaggerated for convenience of explanation. In particular, the shapes of the spherical or aspherical surfaces shown in the drawings are shown by way of example. That is, the shape of the spherical surface or the aspherical surface is not limited to the shape of the spherical surface or the aspherical surface shown in the drawings. The figures are purely diagrammatic and not drawn to scale.

Herein, the paraxial region refers to a region near the optical axis. If the lens surface is convex and the convex position 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 concave position is not defined, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the object is called the object side surface of the lens, and the surface of each lens closest to the imaging surface is called the image side surface of the lens.

It will be further understood that the terms "comprises," "comprising," "has," "having," "includes" and/or "including," when used in this specification, specify the presence of stated features, elements, and/or components, but do not preclude the presence or addition of one or more other features, elements, components, and/or groups thereof. Moreover, when a statement such as "at least one of" appears after a list of listed features, the entirety of the listed features is modified rather than modifying individual elements in the list. Furthermore, when describing embodiments of the present application, the use of "may" mean "one or more embodiments of the present application. Also, the term "exemplary" is intended to refer to an example or illustration.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present application will be described in detail below with reference to the embodiments with reference to the attached drawings.

The features, principles, and other aspects of the present application are described in detail below.

An optical imaging system according to an exemplary embodiment of the present application may include seven lenses having optical powers, respectively, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens. The seven lenses are arranged along the optical axis in sequence from the object side to the image side. Any adjacent two lenses of the first lens to the seventh lens may have a spacing distance therebetween.

In an exemplary embodiment, the first lens may have a positive optical power; the second lens may have a negative optical power; the third lens may have a positive optical power or a negative optical power; the fourth lens can have negative focal power, and the image side surface of the fourth lens can be a convex surface; the fifth lens may have a positive power or a negative power; the sixth lens can have positive focal power or negative focal power, and the object side surface of the sixth lens can be a concave surface; and the seventh lens may have a positive power or a negative power.

In an exemplary embodiment, an optical imaging system according to the present application may satisfy: 1.0 < TTL/Imgh < 1.3, wherein TTL is the distance between the object side surface of the first lens and the imaging surface of the optical imaging system on the optical axis, and Imgh is half of the length of the diagonal line of the effective pixel area on the imaging surface of the optical imaging system. More specifically, TTL and ImgH may further satisfy: TTL/ImgH is more than 1.1 and less than 1.3. The TTL/ImgH is more than 1.0 and less than 1.3, and the ultrathin characteristic is favorably realized.

In an exemplary embodiment, an optical imaging system according to the present application may satisfy: 0.5 < R9/f < 1.2, where f is the total effective focal length of the optical imaging system and R9 is the radius of curvature of the object-side surface of the fifth lens. More specifically, R9 and f further satisfy: r9/f is more than 0.8 and less than 1.1. R9/f is more than 0.5 and less than 1.2, so that the field curvature and distortion of the optical imaging system can be reduced, and the processing difficulty of the fifth lens can be reduced.

In an exemplary embodiment, an optical imaging system according to the present application may satisfy: -4.5 < f2/f1 < -2.0, wherein f2 is the effective focal length of the second lens and f1 is the effective focal length of the first lens. Satisfying-4.5 < f2/f1 < -2.0, the ghost image formed by the total internal reflection of the second lens can be controlled, and the sensitivity of the second lens can be reduced.

In an exemplary embodiment, an optical imaging system according to the present application may satisfy: -1.5 < f/f7 < -1.0, wherein f is the total effective focal length of the optical imaging system and f7 is the effective focal length of the seventh lens. More specifically, f and f7 further satisfy: -1.5 < f/f7 < -1.1. Satisfying-1.5 < f/f7 < -1.0, the seventh lens sensitivity can be reduced.

In an exemplary embodiment, an optical imaging system according to the present application may satisfy: 4.0 < R2/R1 < 6.0, wherein R1 is the radius of curvature of the object-side surface of the first lens and R2 is the radius of curvature of the image-side surface of the first lens. More specifically, R2 and R1 may further satisfy: 4.0 < R2/R1 < 5.8. The requirement that R2/R1 is more than 4.0 and less than 6.0 is met, the sensitivity of the system is favorably reduced, and meanwhile, the first lens can be ensured to have good manufacturability.

In an exemplary embodiment, an optical imaging system according to the present application may satisfy: 1.0 < f5/R9 < 1.5, wherein f5 is the effective focal length of the fifth lens and R9 is the radius of curvature of the object side of the fifth lens. More specifically, f5 and R9 may further satisfy: f5/R9 is more than 1.2 and less than 1.5. Satisfying 1.0 < f5/R9 < 1.5, the ghost image formed by the total internal reflection of the fifth lens can be controlled, and the sensitivity of the fifth lens can be reduced.

In an exemplary embodiment, an optical imaging system according to the present application may satisfy: 2.0 < f4/R7 < 4.0, wherein f4 is the effective focal length of the fourth lens and R7 is the radius of curvature of the object side of the fourth lens. More specifically, f4 and R7 may further satisfy: 2.2 < f4/R7 < 3.8. Satisfying 2.0 < f4/R7 < 4.0, the deflection angle of the fringe field at the fourth lens can be controlled, and the sensitivity of the system can be effectively reduced.

In an exemplary embodiment, an optical imaging system according to the present application may satisfy: 0.5 < R10/R12 < 1.5, wherein R10 is a radius of curvature of an image-side surface of the fifth lens, and R12 is a radius of curvature of an image-side surface of the sixth lens. More specifically, R10 and R12 may further satisfy: 0.6 < R10/R12 < 1.3. The requirement that R10/R12 is more than 0.5 and less than 1.5 is met, and the stability of system assembly is improved.

In an exemplary embodiment, an optical imaging system according to the present application may satisfy: 11.7 < R11/R14 < -7.7, wherein R11 is the radius of curvature of the object-side surface of the sixth lens and R14 is the radius of curvature of the image-side surface of the seventh lens. Satisfy-11.7 < R11/R14 < -7.7, help to improve the stability of system assembly.

In an exemplary embodiment, an optical imaging system according to the present application may satisfy: 4.7 < T67/T56 < 10.3, wherein T56 is the distance between the fifth lens and the sixth lens on the optical axis, and T67 is the distance between the sixth lens and the seventh lens on the optical axis. The requirement that T67/T56 is more than 4.7 and less than 10.3 is met, the deflection degree of light rays is favorably reduced, the sensitivity is reduced, and meanwhile, the imaging quality of the optical imaging system in an infinite state (namely when a shot object is far away from the optical imaging system) can be ensured.

In an exemplary embodiment, an optical imaging system according to the present application may satisfy: fno is less than or equal to 1.9, wherein the Fno is the relative F number of the optical imaging system. Fno is less than or equal to 1.9, the energy density on an imaging surface can be effectively improved, and the signal-to-noise ratio of the output signal of the image side sensor is improved.

In an exemplary embodiment, an optical imaging system according to the present application may satisfy: 40 ° < Semi-FOV < 45 °, where Semi-FOV is half of the maximum field angle of the optical imaging system. More specifically, the Semi-FOV further satisfies: 41 < Semi-FOV < 43. The condition that 40 degrees is less than Semi-FOV is less than 45 degrees is satisfied, and the optical imaging system still has a better imaging range under a smaller volume.

In an exemplary embodiment, the optical imaging system according to the present application further comprises a stop disposed between the second lens and the third lens. Optionally, the optical imaging system may further include a filter for correcting color deviation and/or a protective glass for protecting the photosensitive element on the imaging surface. The application provides an optical imaging system with the characteristics of miniaturization, lightness and thinness, better matching with an image sensor, high imaging quality and the like. The optical imaging system according to the above-described embodiment of the present application may employ a plurality of lenses, such as the above seven lenses. By reasonably distributing the focal power and the surface shape of each lens, the central thickness of each lens, the on-axis distance between each lens and the like, incident light can be effectively converged, the optical total length of the imaging lens is reduced, the processability of the imaging system is improved, and the optical imaging system is more favorable for production and processing.

In the embodiment of the present application, at least one of the mirror surfaces of each lens is an aspherical mirror surface, that is, at least one of the object-side surface of the first lens to the image-side surface of the seventh lens is an aspherical mirror surface. The aspheric lens is characterized in that: the curvature varies 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 better curvature radius characteristics, and has advantages of improving distortion aberration and improving astigmatic aberration. After the aspheric lens is adopted, the aberration generated during imaging can be eliminated as much as possible, thereby improving the imaging quality. Optionally, at least one of an object-side surface and an image-side surface of each of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens is an aspheric mirror surface. Optionally, each of the first, second, third, fourth, fifth, sixth, and seventh lenses has an object-side surface and an image-side surface that are aspheric mirror surfaces.

However, it will be appreciated by those skilled in the art that the number of lenses constituting the optical imaging system may be varied to achieve the various results and advantages described in the present specification without departing from the claimed subject matter. For example, although seven lenses are exemplified in the embodiment, the optical imaging system is not limited to include seven lenses. The optical imaging system may also include other numbers of lenses, if desired.

Specific examples of the optical imaging system that can be applied to the above-described embodiments are further described below with reference to the drawings.

Example 1

An optical imaging system according to embodiment 1 of the present application is described below with reference to fig. 1 to 2C. Fig. 1 shows a schematic configuration diagram of an optical imaging system according to embodiment 1 of the present application.

As shown in fig. 1, the optical imaging system, in order from an object side to an image side, comprises: a first lens E1, a second lens E2, a stop STO, 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 image plane S17.

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

Table 1 shows a basic parameter table of the optical imaging system of example 1, in which the units of the radius of curvature, the thickness/distance, and the focal length are all millimeters (mm).

TABLE 1

In the present example, the total effective focal length F of the optical imaging system is 5.07mm, the total length TTL of the optical imaging system (i.e., the distance on the optical axis from the object-side surface S1 of the first lens E1 to the imaging surface S17 of the optical imaging system) is 5.90mm, the half ImgH of the diagonal length of the effective pixel region on the imaging surface S17 of the optical imaging system is 4.84mm, the half semifov of the maximum field angle of the optical imaging system is 42.3 °, and the relative F-number Fno of the optical imaging system is 1.88.

In embodiment 1, the object-side surface and the image-side surface of any one of the first lens E1 through the seventh lens E7 are aspheric surfaces, and the surface shape x of each aspheric lens can be defined by, but is not limited to, the following aspheric surface formula:

wherein x is the rise of the distance from the aspheric surface vertex to the aspheric surface vertex when the aspheric surface is at the position with the height of h along the optical axis direction; c is the paraxial curvature of the aspheric surface, c being 1/R (i.e., paraxial curvature c is the inverse of radius of curvature R in table 1 above); k is a conic coefficient; ai is the correction coefficient of the i-th order of the aspherical surface. The high-order term coefficients A that can be used for the aspherical mirror surfaces S1 through S14 in example 1 are shown in tables 2-1 and 2-2 below₄、A₆、A₈、A₁₀、A₁₂、A₁₄、A₁₆、A₁₈、A₂₀、A₂₂、A₂₄、A₂₆、A₂₈And A₃₀。

Flour mark

A4

A6

A8

A10

A12

A14

A16

S1

-4.1436E-03

-5.6024E-03

-4.2066E-03

-1.5324E-03

-6.2628E-04

-8.7896E-05

-3.5521E-05

S2

-3.2214E-02

1.6013E-03

-1.5183E-03

3.8051E-05

3.0975E-05

-3.8663E-06

9.0831E-06

S3

3.6942E-02

9.7140E-03

-1.0709E-03

8.5198E-04

-2.4567E-04

1.9309E-04

-9.9439E-05

S4

5.4399E-02

1.8798E-03

2.6795E-04

-3.4474E-04

1.7078E-04

-1.3252E-04

9.5665E-05

S5

-7.6236E-02

-1.5681E-02

-2.3640E-03

-2.7138E-03

-7.4990E-04

-1.0542E-03

-3.5283E-04

S6

-1.5628E-01

-7.1500E-03

1.7892E-04

1.4829E-03

3.9116E-04

2.4603E-04

6.5762E-05

S7

-2.9168E-01

1.5030E-02

-4.1694E-03

1.9443E-04

-6.5935E-04

-1.3373E-04

3.7697E-05

S8

-3.8189E-01

9.1905E-02

-6.6020E-03

-2.0082E-03

-1.5675E-03

3.7413E-04

2.7817E-04

S9

-1.1089E+00

1.3962E-02

4.1901E-02

1.4883E-02

-1.5582E-03

-4.3094E-03

-1.0070E-03

S10

-4.4184E-01

-1.1060E-01

5.5262E-02

2.0977E-02

-6.7968E-04

-1.4267E-03

-1.1235E-03

S11

-4.9073E-01

-8.2395E-02

3.8060E-02

1.2660E-02

-9.4011E-03

-1.6238E-03

-1.3132E-03

S12

-4.7598E-01

-6.7287E-02

8.3223E-02

1.2780E-02

-2.0939E-03

-6.7406E-03

8.2930E-05

S13

-2.5019E+00

1.2515E+00

-5.7007E-01

2.6836E-01

-1.3029E-01

6.5327E-02

-2.4765E-02

S14

-7.8797E+00

1.5794E+00

-5.1567E-01

2.4604E-01

-9.3190E-02

5.2087E-02

-4.3297E-02

TABLE 2-1

Flour mark

A18

A20

A22

A24

A26

A28

A30

S1

3.2267E-05

-2.4214E-07

1.2732E-05

-3.3798E-06

3.7098E-06

-4.3717E-06

1.3653E-06

S2

-3.3548E-06

2.7694E-06

-3.9319E-06

-5.0743E-07

-1.8795E-06

1.3285E-06

3.2963E-07

S3

8.2754E-05

-5.9240E-05

3.7845E-05

-2.3093E-05

1.6759E-05

-2.5409E-05

1.1316E-05

S4

-6.4625E-05

3.5939E-05

-3.0866E-05

1.4586E-05

-1.9271E-05

2.0353E-05

-6.0687E-06

S5

-4.4307E-04

-9.6725E-05

-1.4335E-04

5.1825E-06

5.3983E-06

5.5190E-05

-8.9500E-06

S6

5.2150E-05

5.7557E-06

7.9757E-06

-9.8120E-07

2.6862E-06

-1.1707E-06

5.2841E-07

S7

4.5202E-05

3.9940E-05

-2.6833E-05

-5.9295E-06

-9.0612E-06

6.4455E-06

-5.1883E-06

S8

4.0618E-06

-2.5616E-05

-2.2441E-05

8.8720E-06

7.2933E-07

1.7749E-06

-9.5385E-07

S9

3.2359E-04

3.4432E-04

-3.7737E-04

1.5867E-05

1.0838E-04

7.7254E-05

-4.4740E-05

S10

3.6937E-04

4.9900E-05

-1.4696E-03

9.1188E-04

-5.1903E-04

4.2279E-05

1.7287E-04

S11

9.5450E-04

2.7066E-03

1.9381E-03

2.3055E-03

-2.3648E-03

-4.8517E-04

2.1295E-04

S12

1.7133E-03

2.1473E-03

-4.9281E-03

-7.5351E-03

-6.8258E-03

-1.4105E-03

-4.0951E-04

S13

1.6453E-02

-5.7759E-03

1.8912E-03

-2.7019E-03

-8.9049E-04

1.0125E-03

-1.0907E-03

S14

7.6736E-03

-3.9013E-03

6.3529E-03

1.3732E-03

2.6627E-03

-7.0392E-05

9.4992E-04

Tables 2 to 2

Fig. 2A shows an on-axis chromatic aberration curve of the optical imaging system of embodiment 1, which represents the deviation of the convergent focal points of light rays of different wavelengths after passing through the lens. Fig. 2B shows an astigmatism curve representing meridional field curvature and sagittal field curvature of the optical imaging system of embodiment 1. Fig. 2C shows a distortion curve of the optical imaging system of embodiment 1, which represents distortion magnitude values corresponding to different image heights. As can be seen from fig. 2A to 2C, the optical imaging system according to embodiment 1 can achieve good imaging quality.

Example 2

An optical imaging system according to embodiment 2 of the present application is described below with reference to fig. 3 to 4C. In this embodiment and the following embodiments, descriptions of parts similar to those of embodiment 1 will be omitted for the sake of brevity. Fig. 3 shows a schematic structural diagram of an optical imaging system according to embodiment 2 of the present application.

As shown in fig. 3, the optical imaging system, in order from an object side to an image side, comprises: a first lens E1, a second lens E2, a stop STO, 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 image plane S17.

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

In this example, the total effective focal length F of the optical imaging system is 5.13mm, the total length TTL of the optical imaging system is 6.15mm, the half ImgH of the diagonal length of the effective pixel area on the imaging plane S17 of the optical imaging system is 4.84mm, the half Semi-FOV of the maximum field angle of the optical imaging system is 41.9 °, and the relative F-number Fno of the optical imaging system is 1.90.

Table 3 shows a basic parameter table of the optical imaging system of example 2, in which the units of the radius of curvature, the thickness/distance, and the focal length are all millimeters (mm). Tables 4-1, 4-2 show the high-order term coefficients that can be used for each aspherical mirror surface in example 2, wherein each aspherical mirror surface type can be defined by the formula (1) given in example 1 above.

TABLE 3

TABLE 4-1

Flour mark

A18

A20

A22

A24

A26

A28

A30

S1

3.2267E-05

-2.4214E-07

1.2732E-05

-3.3798E-06

3.7098E-06

-4.3717E-06

1.3653E-06

S2

-3.3548E-06

2.7694E-06

-3.9319E-06

-5.0743E-07

-1.8795E-06

1.3285E-06

3.2963E-07

S3

9.2553E-06

1.1431E-06

4.0892E-06

-1.6688E-06

1.5066E-08

-1.6608E-06

3.5752E-06

S4

1.2044E-05

1.3569E-05

3.3967E-06

4.4548E-06

1.0539E-06

2.4404E-06

-1.3883E-06

S5

8.6367E-05

5.0388E-06

3.2160E-05

3.9142E-06

2.1198E-05

6.9283E-06

1.3252E-05

S6

5.2150E-05

5.7557E-06

7.9757E-06

-9.8120E-07

2.6862E-06

-1.1707E-06

5.2841E-07

S7

5.0334E-05

3.5208E-05

7.7157E-06

4.2276E-06

3.0629E-06

1.1574E-06

-1.6932E-06

S8

4.0618E-06

-2.5616E-05

-2.2441E-05

8.8720E-06

7.2933E-07

1.7749E-06

-9.5385E-07

S9

2.4852E-04

3.5415E-04

3.5623E-05

4.6578E-05

-1.2989E-04

-4.1641E-05

-1.0717E-06

S10

-1.3753E-03

4.4533E-04

3.9747E-04

9.8775E-04

-3.2228E-04

1.8532E-03

7.5618E-04

S11

-4.4964E-03

-1.4372E-03

-1.3562E-03

-1.5483E-03

-2.6196E-03

2.2036E-03

1.0336E-03

S12

1.7656E-03

2.1849E-03

-1.0220E-04

-1.3639E-03

-3.5307E-04

2.2864E-03

5.4657E-04

S13

3.6963E-03

-3.3343E-03

2.9601E-03

-1.8669E-03

2.3127E-04

7.5181E-04

-3.1891E-04

S14

1.5155E-02

-4.9215E-03

3.4387E-03

-2.4739E-03

7.2548E-04

-1.0649E-03

5.8829E-04

TABLE 4-2

Fig. 4A shows an on-axis chromatic aberration curve of the optical imaging system of embodiment 2, which represents the deviation of the convergent focal points of light rays of different wavelengths after passing through the lens. Fig. 4B shows an astigmatism curve representing meridional field curvature and sagittal field curvature of the optical imaging system of embodiment 2. Fig. 4C shows a distortion curve of the optical imaging system of embodiment 2, which represents distortion magnitude values corresponding to different image heights. As can be seen from fig. 4A to 4C, the optical imaging system according to embodiment 2 can achieve good imaging quality.

Example 3

An optical imaging system according to embodiment 3 of the present application is described below with reference to fig. 5 to 6C. Fig. 5 shows a schematic structural diagram of an optical imaging system according to embodiment 3 of the present application.

As shown in fig. 5, the optical imaging system, in order from an object side to an image side, comprises: a first lens E1, a second lens E2, a stop STO, 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 image plane S17.

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

In this example, the total effective focal length F of the optical imaging system is 5.13mm, the total length TTL of the optical imaging system is 5.98mm, the half ImgH of the diagonal length of the effective pixel area on the imaging plane S17 of the optical imaging system is 4.84mm, the half Semi-FOV of the maximum field angle of the optical imaging system is 42.3 °, and the relative F-number Fno of the optical imaging system is 1.88.

Table 5 shows a basic parameter table of the optical imaging system of example 3, in which the units of the radius of curvature, the thickness/distance, and the focal length are all millimeters (mm). Tables 6-1, 6-2 show the high-order term coefficients that can be used for each aspherical mirror surface in example 3, wherein each aspherical mirror surface type can be defined by the formula (1) given in example 1 above.

TABLE 5

TABLE 6-1

Flour mark

A18

A20

A22

A24

A26

A28

A30

S1

3.2267E-05

-2.4214E-07

1.2732E-05

-3.3798E-06

3.7098E-06

-4.3717E-06

1.3653E-06

S2

-3.3548E-06

2.7694E-06

-3.9319E-06

-5.0743E-07

-1.8795E-06

1.3285E-06

3.2963E-07

S3

-1.6836E-06

-2.6083E-06

1.1332E-06

-3.0057E-06

-4.5292E-06

9.0533E-07

1.1052E-05

S4

1.2758E-05

1.1717E-05

1.1447E-05

-2.3897E-06

3.8295E-06

3.7527E-06

2.4525E-06

S5

4.2936E-05

-8.5054E-06

9.3606E-06

-1.5775E-05

1.6638E-05

-3.6590E-06

7.1021E-06

S6

5.2150E-05

5.7557E-06

7.9757E-06

-9.8120E-07

2.6862E-06

-1.1707E-06

5.2841E-07

S7

4.2751E-05

2.7377E-05

1.0117E-05

7.3286E-06

-9.9277E-07

3.9435E-07

-4.0660E-07

S8

4.0618E-06

-2.5616E-05

-2.2441E-05

8.8720E-06

7.2933E-07

1.7749E-06

-9.5385E-07

S9

2.4719E-04

3.5176E-04

-3.3807E-04

9.7061E-05

2.2172E-04

5.4714E-05

-7.9797E-05

S10

-4.3058E-04

-9.9693E-04

-1.8631E-03

1.6847E-03

6.6007E-04

-4.2190E-05

-1.4726E-04

S11

1.1293E-03

1.9850E-03

1.9848E-03

2.4078E-03

-2.2687E-03

-1.9111E-03

-5.4706E-04

S12

1.7663E-03

2.1964E-03

-1.0656E-03

-3.6691E-03

-3.9984E-03

-2.9269E-04

-2.7774E-04

S13

4.5772E-03

-1.0261E-03

2.6534E-03

-1.8832E-03

4.6747E-04

8.1323E-04

-4.6023E-04

S14

1.1652E-02

-5.9050E-03

2.7267E-03

-5.2921E-04

2.7755E-03

-2.8268E-04

4.3938E-04

TABLE 6-2

Fig. 6A shows an on-axis chromatic aberration curve of the optical imaging system of embodiment 3, which represents the convergent focus deviation of light rays of different wavelengths after passing through the lens. Fig. 6B shows an astigmatism curve representing meridional field curvature and sagittal field curvature of the optical imaging system of embodiment 3. Fig. 6C shows a distortion curve of the optical imaging system of embodiment 3, which represents distortion magnitude values corresponding to different image heights. As can be seen from fig. 6A to 6C, the optical imaging system according to embodiment 3 can achieve good imaging quality.

Example 4

An optical imaging system according to embodiment 4 of the present application is described below with reference to fig. 7 to 8C. Fig. 7 shows a schematic structural diagram of an optical imaging system according to embodiment 4 of the present application.

As shown in fig. 7, the optical imaging system, in order from an object side to an image side, comprises: a first lens E1, a second lens E2, a stop STO, 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 image plane S17.

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

In this example, the total effective focal length F of the optical imaging system is 5.05mm, the total length TTL of the optical imaging system is 5.94mm, the half ImgH of the diagonal length of the effective pixel area on the imaging plane S17 of the optical imaging system is 4.84mm, the half Semi-FOV of the maximum field angle of the optical imaging system is 42.5 °, and the relative F-number Fno of the optical imaging system is 1.87.

Table 7 shows a basic parameter table of the optical imaging system of example 4 in which the units of the radius of curvature, thickness/distance, and focal length are all millimeters (mm). Tables 8-1, 8-2 show the high-order term coefficients that can be used for each aspherical mirror surface in example 4, wherein each aspherical mirror surface type can be defined by the formula (1) given in example 1 above.

TABLE 7

TABLE 8-1

Flour mark

A18

A20

A22

A24

A26

A28

A30

S1

3.2267E-05

-2.4214E-07

1.2732E-05

-3.3798E-06

3.7098E-06

-4.3717E-06

1.3653E-06

S2

-3.3548E-06

2.7694E-06

-3.9319E-06

-5.0743E-07

-1.8795E-06

1.3285E-06

3.2963E-07

S3

1.4660E-06

-4.1143E-07

7.1360E-06

2.4709E-06

3.2505E-06

1.6451E-06

5.3311E-06

S4

-4.4220E-07

2.9112E-06

6.8342E-06

1.2627E-06

-1.0049E-06

-8.6924E-07

2.5092E-06

S5

3.3037E-05

-1.6416E-05

5.1573E-06

-1.2108E-05

7.6145E-06

9.0460E-07

8.0812E-06

S6

5.2150E-05

5.7557E-06

7.9757E-06

-9.8120E-07

2.6862E-06

-1.1707E-06

5.2841E-07

S7

4.4965E-05

3.7565E-05

3.1030E-06

-1.3997E-05

-1.6168E-05

-1.0736E-05

-2.3153E-06

S8

4.0618E-06

-2.5616E-05

-2.2441E-05

8.8720E-06

7.2933E-07

1.7749E-06

-9.5385E-07

S9

2.4593E-04

3.5173E-04

-1.2423E-04

3.2927E-04

1.8501E-04

8.4956E-05

-3.5418E-05

S10

7.2252E-04

-3.4108E-05

-1.0702E-03

1.4530E-03

-2.7545E-04

-1.6981E-04

1.0372E-04

S11

1.3350E-03

1.0452E-03

1.0117E-03

2.2161E-03

-1.9525E-03

-1.0627E-03

1.1482E-04

S12

1.7627E-03

2.1884E-03

1.3861E-03

-4.5982E-04

-2.1702E-03

-1.1830E-04

2.9568E-04

S13

5.9352E-03

-2.8215E-03

1.8646E-03

-8.7796E-04

1.1655E-04

1.1627E-04

1.6815E-04

S14

1.3069E-02

-3.2147E-03

2.2253E-03

-3.4280E-03

1.2021E-03

-5.1123E-04

6.7749E-04

TABLE 8-2

Fig. 8A shows an on-axis chromatic aberration curve of the optical imaging system of embodiment 4, which represents the convergent focus deviation of light rays of different wavelengths after passing through the lens. Fig. 8B shows an astigmatism curve representing meridional field curvature and sagittal field curvature of the optical imaging system of embodiment 4. Fig. 8C shows a distortion curve of the optical imaging system of embodiment 4, which represents distortion magnitude values corresponding to different image heights. As can be seen from fig. 8A to 8C, the optical imaging system according to embodiment 4 can achieve good imaging quality.

Example 5

An optical imaging system according to embodiment 5 of the present application is described below with reference to fig. 9 to 10C. Fig. 9 shows a schematic structural diagram of an optical imaging system according to embodiment 5 of the present application.

As shown in fig. 9, the optical imaging system, in order from an object side to an image side, comprises: a first lens E1, a second lens E2, a stop STO, 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 image plane S17.

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

In this example, the total effective focal length F of the optical imaging system is 5.08mm, the total length TTL of the optical imaging system is 5.93mm, the half ImgH of the diagonal length of the effective pixel area on the imaging plane S17 of the optical imaging system is 4.84mm, the half Semi-FOV of the maximum field angle of the optical imaging system is 42.3 °, and the relative F-number Fno of the optical imaging system is 1.88.

Table 9 shows a basic parameter table of the optical imaging system of example 5 in which the units of the radius of curvature, thickness/distance, and focal length are all millimeters (mm). Tables 10-1, 10-2 show the high-order term coefficients that can be used for each aspherical mirror surface in example 5, wherein each aspherical mirror surface type can be defined by the formula (1) given in example 1 above.

TABLE 9

TABLE 10-1

Flour mark

A18

A20

A22

A24

A26

A28

A30

S1

3.2267E-05

-2.4214E-07

1.2732E-05

-3.3798E-06

3.7098E-06

-4.3717E-06

1.3653E-06

S2

-3.3548E-06

2.7694E-06

-3.9319E-06

-5.0743E-07

-1.8795E-06

1.3285E-06

3.2963E-07

S3

1.8836E-06

-3.4516E-09

3.2989E-06

2.6447E-06

5.1117E-07

1.6074E-07

2.7402E-06

S4

9.3625E-06

7.3648E-06

4.6183E-06

1.8159E-06

-1.3152E-07

1.1356E-06

1.0137E-06

S5

2.0313E-05

-2.3419E-06

4.4297E-06

2.8700E-06

-5.8993E-07

-4.8021E-06

-3.6880E-07

S6

5.2150E-05

5.7557E-06

7.9757E-06

-9.8120E-07

2.6862E-06

-1.1707E-06

5.2841E-07

S7

4.7122E-05

3.7481E-05

-5.4678E-06

-1.0961E-05

-1.3606E-05

-1.7326E-07

-1.2239E-06

S8

4.0618E-06

-2.5616E-05

-2.2441E-05

8.8720E-06

7.2933E-07

1.7749E-06

-9.5385E-07

S9

2.4613E-04

3.5196E-04

-1.8374E-04

2.4512E-04

1.0856E-04

-1.8817E-05

-2.6022E-05

S10

-3.0882E-04

5.0783E-04

-1.1892E-03

1.2054E-03

-3.1140E-04

-2.0128E-04

1.3411E-04

S11

2.6768E-04

2.5324E-03

2.2625E-03

1.9010E-03

-2.6353E-03

-7.6718E-04

2.6674E-04

S12

1.7598E-03

2.1831E-03

1.8081E-03

-1.3253E-03

-2.3421E-03

2.5624E-04

2.6884E-04

S13

1.5482E-02

-8.8066E-03

1.2416E-03

-8.1247E-03

2.8030E-03

-4.3071E-03

-1.0933E-04

S14

2.8060E-02

-2.3996E-02

-5.4700E-03

-1.2206E-02

2.6243E-03

-1.1547E-03

2.6747E-03

TABLE 10-2

Fig. 10A shows an on-axis chromatic aberration curve of the optical imaging system of embodiment 5, which represents the convergent focus deviation of light rays of different wavelengths after passing through the lens. Fig. 10B shows an astigmatism curve representing meridional field curvature and sagittal field curvature of the optical imaging system of example 5. Fig. 10C shows a distortion curve of the optical imaging system of embodiment 5, which represents distortion magnitude values corresponding to different image heights. As can be seen from fig. 10A to 10C, the optical imaging system according to embodiment 5 can achieve good imaging quality.

In summary, examples 1 to 5 satisfy the relationships shown in table 11, respectively.

TABLE 11

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

The above description is only a preferred embodiment of the application and is illustrative of the principles of the technology employed. It will be appreciated by those skilled in the art that the scope of the invention herein disclosed is not limited to the particular combination of features described above, but also encompasses other arrangements formed by any combination of the above features or their equivalents without departing from the inventive concept. For example, the above features may be replaced with (but not limited to) features having similar functions disclosed in the present application.

Claims

1. The optical imaging system, in order from an object side to an image side along an optical axis, comprises:

a first lens having a positive optical power;

a second lens having a negative optical power;

a diaphragm;

a third lens having optical power;

the image side surface of the fourth lens is a convex surface;

a fifth lens having optical power;

a sixth lens having a refractive power, an object side surface of which is concave; and

a seventh lens having optical power;

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 and the half ImgH of the diagonal length of the effective pixel area on the imaging surface of the optical imaging system satisfy that: TTL/ImgH is more than 1.0 and less than 1.3.

2. The optical imaging system of claim 1, wherein the total effective focal length f of the optical imaging system and the radius of curvature R9 of the object side surface of the fifth lens satisfy: r9/f is more than 0.5 and less than 1.2.

3. The optical imaging system of claim 1, wherein the effective focal length f2 of the second lens and the effective focal length f1 of the first lens satisfy: -4.5 < f2/f1 < -2.0.

4. The optical imaging system of claim 1, wherein the total effective focal length f of the optical imaging system and the effective focal length f7 of the seventh lens satisfy: -1.5 < f/f7 < -1.0.

5. The optical imaging system of claim 1, wherein the radius of curvature R1 of the object-side surface of the first lens and the radius of curvature R2 of the image-side surface of the first lens satisfy: 4.0 < R2/R1 < 6.0.

6. The optical imaging system of claim 1, wherein an effective focal length f5 of the fifth lens and a radius of curvature R9 of an object side of the fifth lens satisfy: f5/R9 is more than 1.0 and less than 1.5.

7. The optical imaging system of claim 1, wherein an effective focal length f4 of the fourth lens and a radius of curvature R7 of an object side of the fourth lens satisfy: 2.0 < f4/R7 < 4.0.

8. The optical imaging system of claim 1, wherein the radius of curvature R10 of the image-side surface of the fifth lens and the radius of curvature R12 of the image-side surface of the sixth lens satisfy: 0.5 < R10/R12 < 1.5.

9. The optical imaging system of claim 1, wherein a radius of curvature R11 of an object-side surface of the sixth lens and a radius of curvature R14 of an image-side surface of the seventh lens satisfy: 11.7 < R11/R14 < -7.7.

10. The optical imaging system, in order from an object side to an image side along an optical axis, comprises:

a first lens having a positive optical power;

a second lens having a negative optical power;

a diaphragm;

a third lens having optical power;

the image side surface of the fourth lens is a convex surface;

a fifth lens having optical power;

a seventh lens having optical power;

the total effective focal length f of the optical imaging system and the curvature radius R9 of the object side surface of the fifth lens meet the following conditions: r9/f is more than 0.5 and less than 1.2.