CN114280760B

CN114280760B - Optical imaging system

Info

Publication number: CN114280760B
Application number: CN202111617027.1A
Authority: CN
Inventors: 贺凌波; 赵跇坤; 戴付建; 赵烈烽
Original assignee: Zhejiang Sunny Optics Co Ltd
Current assignee: Zhejiang Sunny Optics Co Ltd
Priority date: 2021-12-27
Filing date: 2021-12-27
Publication date: 2024-02-20
Anticipated expiration: 2041-12-27
Also published as: CN114280760A

Abstract

The invention provides an optical imaging system. The optical imaging system sequentially comprises the following components from the light inlet side to the light outlet side: a first lens element with negative refractive power; a second lens element with negative refractive power having a convex surface facing the light-incident side; a third lens element with refractive power having a concave surface facing the light-exiting side; a fourth lens element with refractive power; a fifth lens element with refractive power; wherein the maximum field angle FOV of the optical imaging system satisfies: the FOV is > 150 deg.. The invention solves the problem of small shooting range of the optical lens in the prior art.

Description

Optical imaging system

Technical Field

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

Background

Along with the rapid development of smart phones, the smart phones are widely applied to various imaging fields in daily life besides being important communication equipment in daily life, so that requirements of people on imaging functions of the smart phones are higher and higher, and particularly when objects with wider fields such as mountains and rivers are imaged. In this case, the wide-angle lens is favored by more and more mobile phone manufacturers and consumers. Compared with the common mobile phone lens, the wide-angle lens has longer depth of field, can clearly image in a quite large range, has larger visual angle and can obtain a larger view finding range in a limited range. In addition, the perspective sense of the lens is stronger, and the shot pictures more emphasize the contrast of the near view and the far view, so that a strong perspective effect is generated in the depth direction. However, in the existing products, the shooting range of the optical lens is small.

That is, the optical lens in the related art has a problem of a small photographing range.

Disclosure of Invention

The invention mainly aims to provide an optical imaging system so as to solve the problem that an optical lens in the prior art has a small shooting range.

In order to achieve the above object, according to one aspect of the present invention, there is provided an optical imaging system including, in order from an light-in side to a light-out side of the optical imaging system: a first lens element with negative refractive power; a second lens element with negative refractive power having a convex surface facing the light-incident side; a third lens element with refractive power having a concave surface facing the light-exiting side; a fourth lens element with refractive power; a fifth lens element with refractive power; wherein the maximum field angle FOV of the optical imaging system satisfies: the FOV is > 150 deg..

Further, the fourth lens satisfies between a center thickness CT4 on the optical axis and an edge thickness ET4 of the fourth lens: CT4/ET4 is less than 3.5 and less than 5.0.

Further, the effective focal length f of the optical imaging system and the entrance pupil diameter EPD of the optical imaging system satisfy: f/EPD < 2.6.

Further, the on-axis distance TTL from the surface of the first lens facing the light-incident side to the imaging surface, and the air interval T12 between the first lens and the second lens on the optical axis satisfy: TTL/T12 is less than 5.0 and more than 4.0.

Further, the edge thickness ET5 of the fifth lens and the center thickness CT5 of the fifth lens on the optical axis satisfy: ET5/CT5 is less than 1.5 and less than 2.5.

Further, an on-axis distance SAG51 between an edge thickness ET5 of the fifth lens and an intersection point of a surface of the fifth lens facing the light incident side and the optical axis to an effective radius vertex of the surface of the fifth lens facing the light incident side satisfies: -6.5 < ET5/SAG51 < -1.5.

Further, an on-axis distance SAG42 between the center thickness CT4 of the fourth lens on the optical axis and an intersection point of the surface of the fourth lens facing the light exit side and the optical axis to an effective radius vertex of the surface of the fourth lens facing the light exit side satisfies: -2.5 < CT4/SAG42 < -1.5.

Further, the center thickness CT3 of the third lens on the optical axis and the center thickness CT2 of the second lens on the optical axis satisfy: CT3/CT2 is more than 1.0 and less than 2.0.

Further, the air interval T12 of the first lens and the second lens on the optical axis, the center thickness CT1 of the first lens on the optical axis, satisfies: T12/CT1 is more than 3.0 and less than 6.0.

Further, the curvature radius R7 of the surface of the fourth lens facing the light incident side and the curvature radius R8 of the surface of the fourth lens facing the light emergent side satisfy: 3.5 < (R8-R7)/(R8+R7) < 14.0.

Further, the curvature radius R4 of the surface of the second lens facing the light-emitting side and the effective focal length f of the optical imaging system satisfy: r4/f is more than 3.0 and less than 6.0.

Further, the abbe number V5 of the fifth lens satisfies: v5 is less than 20.0.

Further, the effective focal length f1 of the first lens, the radius of curvature R1 of the surface of the first lens facing the light incident side, and the radius of curvature R2 of the surface of the first lens facing the light emergent side satisfy: -1.5 < f 1/(R1+R2) < -0.6.

According to another aspect of the present invention, there is provided an optical imaging system, comprising, in order from an entrance side to an exit side of the optical imaging system: a first lens element with negative refractive power; a second lens element with negative refractive power having a convex surface facing the light-incident side; a third lens element with refractive power having a concave surface facing the light-exiting side; a fourth lens element with refractive power; a fifth lens element with refractive power; the combined focal length f45 of the fourth lens and the fifth lens and the effective focal length f of the optical imaging system satisfy the following conditions: 0.5 < f45/f < 1.5.

Further, the abbe number V5 of the fifth lens satisfies: v5 is less than 20.0.

Further, the combined focal length f45 of the fourth lens and the fifth lens and the effective focal length f of the optical imaging system satisfy: 0.5 < f45/f < 1.5.

By applying the technical scheme of the invention, the optical imaging system sequentially comprises the following steps from the light inlet side to the light outlet side: a first lens element, a second lens element, a third lens element, a fourth lens element and a fifth lens element, the first lens element having negative refractive power; the second lens has negative refractive power, and the surface of the second lens facing the light incident side is a convex surface; the third lens has refractive power, and the surface of the third lens facing the light emergent side is a concave surface; the fourth lens element with refractive power; the fifth lens element with refractive power; wherein the maximum field angle FOV of the optical imaging system satisfies: the FOV is > 150 deg..

By setting the refractive power of the first lens to be negative so that the optical imaging system has the advantage of a large field angle, and setting the refractive power of the second lens to be negative and the surface of the second lens facing the light-entering side to be convex is advantageous in increasing the field angle while correcting off-axis aberration of the optical imaging system. The surface of the third lens facing the light emitting side is a concave surface, so that the image quality of the optical imaging system can be effectively improved, and the imaging quality of the optical imaging system is ensured. And the maximum field angle of the optical imaging system is controlled to be larger than 150 degrees, so that a larger field of view can be obtained, and the shooting range of the optical imaging system can be enlarged.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention. In the drawings:

FIG. 1 is a schematic view showing the structure of an optical imaging system according to an example I of the present invention;

fig. 2 to 4 show an on-axis chromatic aberration curve, an astigmatism curve, and a magnification chromatic aberration curve, respectively, of the optical imaging system in fig. 1;

FIG. 5 is a schematic diagram showing the structure of an optical imaging system of example II of the present invention;

Fig. 6 to 8 show on-axis chromatic aberration curves, astigmatism curves, and magnification chromatic aberration curves, respectively, of the optical imaging system in fig. 5;

fig. 9 is a schematic diagram showing the structure of an optical imaging system of example three of the present invention;

fig. 10 to 12 show on-axis chromatic aberration curves, astigmatism curves, and magnification chromatic aberration curves, respectively, of the optical imaging system in fig. 9;

fig. 13 is a schematic diagram showing the structure of an optical imaging system of example four of the present invention;

fig. 14 to 16 show on-axis chromatic aberration curves, astigmatism curves, and magnification chromatic aberration curves, respectively, of the optical imaging system in fig. 13;

fig. 17 is a schematic diagram showing the structure of an optical imaging system of example five of the present invention;

fig. 18 to 20 show an on-axis chromatic aberration curve, an astigmatism curve, and a magnification chromatic aberration curve, respectively, of the optical imaging system in fig. 17;

fig. 21 is a schematic diagram showing the structure of an optical imaging system of example six of the present invention;

fig. 22 to 24 show an on-axis chromatic aberration curve, an astigmatism curve, and a magnification chromatic aberration curve, respectively, of the optical imaging system in fig. 21;

wherein the above figures include the following reference numerals:

STO and diaphragm; e1, a first lens; s1, a surface of a first lens facing a light incident side; s2, the surface of the first lens facing the light emitting side; e2, a second lens; s3, the surface of the second lens facing the light incident side; s4, the surface of the second lens facing the light emitting side; e3, a third lens; s5, the surface of the third lens facing the light incident side; s6, the surface of the third lens facing the light emitting side; e4, a fourth lens; s7, the surface of the fourth lens facing the light incident side; s8, the surface of the fourth lens facing the light emitting side; e5, a fifth lens; s9, the surface of the fifth lens facing the light incident side; s10, the surface of the fifth lens facing the light emitting side; e6, a filter; s11, the surface of the filter sheet facing the light incident side; s12, the surface of the filter sheet facing the light emitting side; s13, an imaging surface.

Detailed Description

It should be noted that, in the case of no conflict, the embodiments and features in the embodiments may be combined with each other. The invention will be described in detail below with reference to the drawings in connection with embodiments.

It is noted that all 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 unless otherwise indicated.

In the present invention, unless otherwise indicated, terms of orientation such as "upper, lower, top, bottom" are used generally with respect to the orientation shown in the drawings or with respect to the component itself in the vertical, upright or gravitational direction; also, for ease of understanding and description, "inner and outer" refers to inner and outer relative to the profile of each component itself, but the above-mentioned orientation terms are not intended to limit the present invention.

It should be noted that in the present 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 feature. Accordingly, a first lens discussed below may also be referred to as a second lens or a third lens without departing from the teachings of the present application.

In the drawings, the thickness, size, and shape of the lenses have been slightly exaggerated for convenience of explanation. Specifically, the spherical or aspherical shape shown in the drawings is shown by way of example. That is, the shape of the spherical or aspherical surface is not limited to the shape of the spherical or aspherical surface shown in the drawings. The figures are merely examples and are 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, then 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 close to the object side becomes the surface of the lens facing the light incident side, and the surface of each lens close to the image side is referred to as the surface of the lens facing the light outgoing side. The determination of the surface shape in the paraxial region can be performed by a determination method by a person skilled in the art by positive or negative determination of the concave-convex with R value (R means the radius of curvature of the paraxial region, and generally means the R value on a lens database (lens data) in optical software). In the object side surface, when the R value is positive, the object side surface is judged to be convex, and when the R value is negative, the object side surface is judged to be concave; in the image side, the concave surface is determined when the R value is positive, and the convex surface is determined when the R value is negative.

In order to solve the problem that an optical lens in the prior art has a small shooting range, the invention provides an optical imaging system.

As shown in fig. 1 to 24, the optical imaging system sequentially includes, from an light-in side to a light-out side: a first lens element, a second lens element, a third lens element, a fourth lens element and a fifth lens element, the first lens element having negative refractive power; the second lens has negative refractive power, and the surface of the second lens facing the light incident side is a convex surface; the third lens has refractive power, and the surface of the third lens facing the light emergent side is a concave surface; the fourth lens element with refractive power; the fifth lens element with refractive power; wherein the maximum field angle FOV of the optical imaging system satisfies: the FOV is > 150 deg..

Preferably, the maximum field angle FOV of the optical imaging system satisfies: 155 DEG < FOV < 175 deg.

In the present embodiment, the fourth lens satisfies between the center thickness CT4 on the optical axis and the edge thickness ET4 of the fourth lens: CT4/ET4 is less than 3.5 and less than 5.0. The CT4/ET4 is controlled in a reasonable range, so that the processing difficulty of the lens can be reduced, the angle between the main light ray and the optical axis when the main light ray is incident on the image plane can be reduced, and the relative illuminance of the image plane can be improved. Preferably, 3.6 < CT4/ET4 < 4.8.

In the present embodiment, the effective focal length f of the optical imaging system and the entrance pupil diameter EPD of the optical imaging system satisfy: f/EPD < 2.6. The ratio of the effective focal length of the optical imaging system to the diameter of the entrance pupil of the optical imaging system is reasonably controlled within a reasonable range, so that a larger field angle is realized, a wider visual field is shot, and a larger clear imaging range is obtained. Preferably, 1.5 < f/EPD < 2.5.

In the present embodiment, the on-axis distance TTL from the surface of the first lens facing the light incident side to the imaging surface, the air interval T12 on the optical axis between the first lens and the second lens satisfies: TTL/T12 is less than 5.0 and more than 4.0. The ratio of the axial distance from the surface of the first lens facing the light incident side to the imaging surface and the air interval between the first lens and the second lens on the optical axis is reasonably controlled within a reasonable range, and the size distribution of the lenses is reasonably distributed so as to obtain high resolution. Preferably, 4.1 < TTL/T12 < 4.8.

In the present embodiment, the edge thickness ET5 of the fifth lens and the center thickness CT5 of the fifth lens on the optical axis satisfy: ET5/CT5 is less than 1.5 and less than 2.5. The ratio range of ET5 and CT5 is reasonably controlled, so that the processing difficulty of the lens can be reduced, the angle between the chief ray and the optical axis when the chief ray is incident on the image surface can be reduced, and the relative illuminance of the image surface can be improved. Preferably, 1.57 < ET5/CT5 < 2.5.

In the present embodiment, an on-axis distance SAG51 between an edge thickness ET5 of the fifth lens and an intersection point of a surface of the fifth lens facing the light incident side and the optical axis to an effective radius vertex of the surface of the fifth lens facing the light incident side satisfies: -6.5 < ET5/SAG51 < -1.5. The ET5/SAG51 is controlled in a reasonable range, so that the angle of the principal ray of the optical imaging system is adjusted, the relative brightness of the optical imaging system can be effectively improved, the image plane definition is improved, and the imaging quality of the optical imaging system is ensured. Preferably, -6.2 < ET5/SAG51 < -1.7.

In the present embodiment, an on-axis distance SAG42 between the center thickness CT4 of the fourth lens on the optical axis and an intersection point of the surface of the fourth lens facing the light exit side and the optical axis to the effective radius vertex of the surface of the fourth lens facing the light exit side satisfies: -2.5 < CT4/SAG42 < -1.5. By controlling the CT4/SAG42 within a reasonable range, the light angle of the optical imaging system can be adjusted, the relative brightness of the optical imaging system can be effectively improved, the image plane definition is improved, and the imaging quality of the optical imaging system is improved. Preferably, -2.4 < CT4/SAG42 < -1.6.

In the present embodiment, the center thickness CT3 of the third lens on the optical axis and the center thickness CT2 of the second lens on the optical axis satisfy: CT3/CT2 is more than 1.0 and less than 2.0. The ratio of the center thickness of the third lens on the optical axis to the center thickness of the second lens on the optical axis is controlled within a certain range, so that the optical lens can be ensured to have good machinability. Preferably, 1.1 < CT3/CT2 < 1.9.

In the present embodiment, the air interval T12 of the first lens and the second lens on the optical axis, the center thickness CT1 of the first lens on the optical axis satisfy: T12/CT1 is more than 3.0 and less than 6.0. The ratio of the air interval of the first lens and the second lens on the optical axis to the central thickness of the first lens on the optical axis is controlled within a certain range, so that the on-axis aberration generated by the first lens can be effectively balanced. Preferably, 3.2 < T12/CT1 < 5.8.

In the present embodiment, the curvature radius R7 of the surface of the fourth lens facing the light incident side and the curvature radius R8 of the surface of the fourth lens facing the light exiting side satisfy: 3.5 < (R8-R7)/(R8+R7) < 14.0. The curvature radius of the surface of the fourth lens facing the light incident side and the curvature radius of the surface of the fourth lens facing the light emergent side are reasonably controlled, the fourth lens is favorable for ensuring proper refractive power, meanwhile, the included angle between the principal ray and the optical axis when entering the image plane is reduced, the illuminance of the image plane is improved, and the optical imaging system can clearly image under the condition of large field angle. Preferably, 3.52 < (R8-R7)/(R8+R7) < 13.95.

In the present embodiment, the curvature radius R4 of the surface of the second lens facing the light-emitting side and the effective focal length f of the optical imaging system satisfy: r4/f is more than 3.0 and less than 6.0. By controlling R4/f within a certain range, the deflection angle of off-axis field light on the surface of the second lens facing the light emitting side can be controlled, and the matching degree with the chip is increased. Preferably, 3.2 < R4/f < 6.0.

In the present embodiment, the abbe number V5 of the fifth lens satisfies: v5 is less than 20.0. The Abbe number of the fifth lens is controlled to be smaller than a certain range, so that the chromatic aberration of the optical imaging system is optimized, and the imaging quality of the optical imaging system is improved. Preferably, 18 < V5 < 20.0.

In the present embodiment, the effective focal length f1 of the first lens, the radius of curvature R1 of the surface of the first lens facing the light entrance side, and the radius of curvature R2 of the surface of the first lens facing the light exit side satisfy: -1.5 < f 1/(R1+R2) < -0.6. By limiting f 1/(r1+r2) to a reasonable range, the focal length of the first lens can be ensured, which is advantageous for the manufacturing and molding of the first lens. Preferably, -1.4 < f 1/(R1+R2) < -0.7.

Example two

As shown in fig. 1 to 24, the optical imaging system sequentially includes, from an light-in side to a light-out side: a first lens, a second lens, a third lens, a fourth lens and a fifth lens. The first lens element with negative refractive power; the second lens has negative refractive power, and the surface of the second lens facing the light incident side is a convex surface; the third lens has refractive power, and the surface of the third lens facing the light emergent side is a concave surface; the fourth lens element with refractive power; the fifth lens element with refractive power; the combined focal length f45 of the fourth lens and the fifth lens and the effective focal length f of the optical imaging system satisfy the following conditions: 0.5 < f45/f < 1.5.

By setting the refractive power of the first lens to be negative so that the optical imaging system has the advantage of a large field angle, and setting the refractive power of the second lens to be negative and the surface of the second lens facing the light-entering side to be convex is advantageous in increasing the field angle while correcting off-axis aberration of the optical imaging system. The surface of the third lens facing the light emitting side is a concave surface, so that the image quality of the optical imaging system can be effectively improved, and the imaging quality of the optical imaging system is ensured. The ratio of the combined focal length of the fourth lens and the fifth lens to the effective focal length of the optical imaging system is controlled within a reasonable range, so that better balance of aberration of the optical imaging system is facilitated, and meanwhile, the resolution of the system is improved.

Preferably, the combined focal length f45 of the fourth lens and the fifth lens and the effective focal length f of the optical imaging system satisfy: 0.7 < f45/f < 1.48.

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

The optical imaging system in the present application may employ a plurality of lenses, such as the five lenses described above. By reasonably distributing the refractive power, the surface shape, the center thickness of each lens, the axial distance between each lens and the like of each lens, 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, so that the optical imaging system is more beneficial to production and processing and can be suitable for portable electronic equipment such as smart phones and the like.

In the present application, at least one of the mirrors of each lens is an aspherical mirror. The aspherical 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 a better radius of curvature characteristic, and has advantages of improving distortion aberration and improving astigmatic aberration. By adopting the aspherical lens, aberration occurring at the time of imaging can be eliminated as much as possible, thereby improving imaging quality.

However, those skilled in the art will appreciate that the number of lenses making up an optical imaging system can be varied to achieve the various results and advantages described in the specification without departing from the technical solutions claimed herein. For example, although the description has been made by taking five lenses as an example in the embodiment, the optical imaging system is not limited to include five lenses. The optical imaging system may also include other numbers of lenses, if desired.

Examples of specific surface types, parameters applicable to the optical imaging system of the above embodiment are further described below with reference to the drawings.

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

Example one

As shown in fig. 1 to 4, an optical imaging system of example one of the present application is described. Fig. 1 shows a schematic diagram of an optical imaging system configuration of example one.

As shown in fig. 1, the optical imaging system includes, in order from a light incident side to a light emergent side, a first lens E1, a stop STO, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a filter E6, and an imaging surface S13.

The first lens element E1 with negative refractive power has a convex surface S1 facing the light incident side and a concave surface S2 facing the light emergent side. The second lens element E2 with negative refractive power has a convex surface on a surface S3 facing the light incident side and a concave surface on a surface S4 facing the light emergent side. The third lens element E3 with positive refractive power has a convex surface S5 facing the light incident side and a concave surface S6 facing the light emergent side. The fourth lens element E4 with positive refractive power has a convex surface S7 facing the light incident side and a convex surface S8 facing the light exiting side. The fifth lens element E5 with negative refractive power has a concave surface on a surface S9 of the fifth lens element facing the light incident side and a concave surface on a surface S10 of the fifth lens element facing the light exiting side. The filter E6 has a surface S11 of the filter facing the light entrance side and a surface S12 of the filter facing the light exit side. Light from the object sequentially passes through the respective surfaces S1 to S12 and is finally imaged on the imaging surface S13.

In the present example, the total effective focal length f of the optical imaging system is 1.09mm, the total length TTL of the optical imaging system is 4.2mm and the image height ImgH is 1.32mm.

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

TABLE 1

In the first example, the surface of any one of the first lens E1 to the fifth lens E5 facing the light incident side and the surface facing the light emergent side are both aspherical, and the surface shape of each aspherical lens can be defined by, but not limited to, the following aspherical formula:

wherein x is the distance vector height from the vertex of the aspheric surface when the aspheric surface is at the position with the height h along the optical axis direction; c is the paraxial curvature of the aspheric surface, c=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 aspherical i-th order. The following Table 2 shows the higher order coefficients A4, A6, A8, A10, A12, A14, A16, A18, A20, A22, A24, A26, A28, A30 that can be used for each of the aspherical mirrors S1-S10 in example one.

TABLE 2

Fig. 2 shows an on-axis chromatic aberration curve of the optical imaging system of example one, which represents the deviation of the converging focus of light rays of different wavelengths after passing through the optical imaging system. Fig. 3 shows an astigmatism curve of the optical imaging system of example one, which represents meridional image plane curvature and sagittal image plane curvature. Fig. 4 shows a magnification chromatic aberration curve of the optical imaging system of example one, which represents the deviation of different image heights on the imaging plane after light passes through the optical imaging system.

As can be seen from fig. 2 to 4, the optical imaging system according to example one can achieve good imaging quality.

Example two

As shown in fig. 5 to 8, an optical imaging system of example two of the present application is described. In this example and the following examples, a description of portions similar to those of example one will be omitted for the sake of brevity. Fig. 5 shows a schematic diagram of the structure of an optical imaging system of example two.

As shown in fig. 5, the optical imaging system includes, in order from the light incident side to the light emergent side, a first lens E1, a stop STO, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a filter E6, and an imaging surface S13.

The first lens element E1 with negative refractive power has a convex surface S1 facing the light incident side and a concave surface S2 facing the light emergent side. The second lens element E2 with negative refractive power has a convex surface on a surface S3 facing the light incident side and a concave surface on a surface S4 facing the light emergent side. The third lens element E3 with positive refractive power has a convex surface S5 facing the light incident side and a concave surface S6 facing the light emergent side. The fourth lens element E4 with positive refractive power has a convex surface S7 facing the light incident side and a convex surface S8 facing the light exiting side. The fifth lens element E5 with negative refractive power has a concave surface on a surface S9 facing the light incident side and a convex surface on a surface S10 facing the light emergent side. The filter E6 has a surface S11 of the filter facing the light entrance side and a surface S12 of the filter facing the light exit side. Light from the object sequentially passes through the respective surfaces S1 to S12 and is finally imaged on the imaging surface S13.

In the present example, the total effective focal length f of the optical imaging system is 1.03mm, the total length TTL of the optical imaging system is 4.72mm and the image height ImgH is 1.32mm.

Table 3 shows a basic structural parameter table of the optical imaging system of example two, in which the units of radius of curvature, thickness/distance, focal length, and effective radius are all millimeters (mm).

TABLE 3 Table 3

Table 4 shows the higher order coefficients that can be used for each of the aspherical mirror surfaces in example two, where each of the aspherical surface types can be defined by equation (1) given in example one above.

Face number

A4

A6

A8

A10

A12

A14

A16

S1

-3.6559E-01

-8.8886E-02

1.8282E-03

-1.1313E-02

-9.0115E-04

-1.3102E-03

-5.1178E-04

S2

1.4212E-01

-3.8513E-03

2.4041E-03

-1.4021E-03

-6.3413E-04

2.4047E-04

6.7476E-04

S3

-1.4694E-02

-1.0623E-03

-1.9585E-04

-1.0869E-05

-9.9096E-06

2.5141E-06

-1.2022E-06

S4

-9.4807E-02

2.4716E-04

-8.9410E-04

8.2624E-05

-8.1890E-05

2.0623E-05

-2.9806E-06

S5

-1.1495E-01

4.8211E-03

-3.8952E-04

5.0985E-04

-2.5690E-05

1.5171E-04

5.6510E-05

S6

-1.7376E-01

1.7865E-02

-3.6828E-03

1.0217E-03

-4.7343E-04

1.3107E-04

-3.2396E-05

S7

-2.9333E-01

4.2947E-02

-1.0390E-02

1.6531E-03

-1.4803E-03

3.3595E-04

-1.6332E-04

S8

3.2547E-02

-6.4438E-03

-1.0700E-02

4.7021E-03

-1.4310E-03

3.4026E-03

-1.5618E-03

S9

-5.2289E-02

1.9130E-02

-4.1255E-03

6.8020E-03

-1.1231E-03

2.3754E-03

-8.1025E-04

S10

-2.0378E-01

-3.3046E-03

9.9773E-03

-1.0942E-03

-6.7676E-04

-8.0193E-04

-4.1071E-07

Face number

A18

A20

A22

A24

A26

A28

A30

S1

-3.0059E-04

-1.1766E-04

-6.0550E-05

2.2854E-06

-7.5403E-06

-1.8877E-05

-2.2751E-05

S2

5.8112E-04

4.1970E-04

2.1011E-04

9.1005E-05

6.2971E-06

-8.7793E-06

-7.7871E-06

S3

3.2291E-07

-1.2792E-06

2.2693E-07

-4.8603E-07

6.2265E-07

-3.6202E-09

-8.0086E-08

S4

5.6371E-06

2.8878E-06

3.3583E-06

2.6174E-06

1.2432E-06

1.1147E-06

2.8679E-07

S5

5.2403E-05

2.5887E-05

1.9166E-05

8.3567E-06

3.7367E-06

1.5465E-07

2.1207E-07

S6

1.8812E-05

-5.9582E-06

7.8112E-07

-5.2302E-07

7.9614E-08

5.5726E-07

-2.0433E-07

S7

3.9012E-05

-2.9891E-05

1.2341E-05

-3.2068E-06

1.0730E-06

-1.0520E-06

1.3898E-06

S8

-3.0402E-05

-1.5930E-04

3.7440E-04

-2.4335E-04

-2.7262E-04

-1.9300E-04

1.5985E-05

S9

-1.6802E-04

-5.6494E-04

4.0717E-05

-5.2493E-06

9.3919E-06

-6.8260E-05

-4.9938E-06

S10

5.1820E-04

2.8501E-04

-8.7405E-05

-4.8323E-04

-3.6251E-04

-1.4144E-04

-2.4790E-05

TABLE 4 Table 4

Fig. 6 shows an on-axis chromatic aberration curve of the optical imaging system of example two, which represents the deviation of the converging focus of light rays of different wavelengths after passing through the optical imaging system. Fig. 7 shows an astigmatism curve of the optical imaging system of example two, which represents meridional image plane curvature and sagittal image plane curvature. Fig. 8 shows a magnification chromatic aberration curve of the optical imaging system of example two, which represents the deviation of different image heights on the imaging plane after light passes through the optical imaging system.

As can be seen from fig. 6 to 8, the optical imaging system according to the second example can achieve good imaging quality.

Example three

As shown in fig. 9 to 12, an optical imaging system of example three of the present application is described. Fig. 9 shows a schematic diagram of the structure of an optical imaging system of example three.

As shown in fig. 9, the optical imaging system includes, in order from the light incident side to the light emergent side, a first lens E1, a stop STO, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a filter E6, and an imaging surface S13.

The first lens element E1 with negative refractive power has a convex surface S1 facing the light incident side and a concave surface S2 facing the light emergent side. The second lens element E2 with negative refractive power has a convex surface on a surface S3 facing the light incident side and a concave surface on a surface S4 facing the light emergent side. The third lens element E3 with positive refractive power has a convex surface S5 facing the light incident side and a concave surface S6 facing the light emergent side. The fourth lens element E4 with positive refractive power has a convex surface S7 facing the light incident side and a convex surface S8 facing the light exiting side. The fifth lens element E5 with negative refractive power has a convex surface S9 facing the light incident side and a concave surface S10 facing the light exiting side. The filter E6 has a surface S11 of the filter facing the light entrance side and a surface S12 of the filter facing the light exit side. Light from the object sequentially passes through the respective surfaces S1 to S12 and is finally imaged on the imaging surface S13.

In the present example, the total effective focal length f of the optical imaging system is 1.04mm, the total length TTL of the optical imaging system is 4.39mm and the image height ImgH is 1.32mm.

Table 5 shows a basic structural parameter table of the optical imaging system of example three, in which the units of radius of curvature, thickness/distance, focal length, and effective radius are all millimeters (mm).

TABLE 5

Table 6 shows the higher order coefficients that can be used for each of the aspherical mirror surfaces in example three, where each of the aspherical surface types can be defined by the formula (1) given in example one above.

Face number

A4

A6

A8

A10

A12

A14

A16

S1

-4.7652E-01

-7.4642E-02

3.0846E-03

-1.0685E-02

-2.9953E-03

-4.5837E-04

-8.1002E-04

S2

6.7945E-02

-2.4282E-02

2.9282E-03

-2.3103E-04

-8.1455E-04

-2.5512E-04

1.3630E-04

S3

-1.6292E-02

-7.2522E-04

-6.5420E-05

5.5895E-05

5.2341E-05

7.3088E-05

5.8749E-05

S4

-8.8391E-02

9.4586E-05

-3.2196E-04

-7.1501E-05

-1.0480E-04

2.0717E-05

-1.1091E-05

S5

-1.0641E-01

5.7003E-03

-1.3249E-05

-1.4672E-04

-3.3023E-04

6.7140E-05

-3.1470E-05

S6

-1.7377E-01

1.9218E-02

-3.1076E-03

8.5167E-04

-9.1340E-04

1.7211E-04

-7.0445E-05

S7

-2.8618E-01

3.5124E-02

-1.2307E-02

3.3431E-03

-1.4981E-03

7.1596E-04

-3.0994E-04

S8

1.1350E-01

-1.8008E-02

-2.8308E-03

4.1521E-03

9.3243E-04

-1.6265E-03

7.8603E-04

S9

-1.4851E-01

1.9811E-02

2.8329E-03

-3.5864E-03

2.2141E-03

-6.8034E-04

5.7428E-05

S10

-2.9833E-01

1.7239E-02

4.6387E-03

-5.4552E-03

4.3298E-03

-6.5535E-04

2.2861E-04

Face number

A18

A20

A22

A24

A26

A28

A30

S1

-2.8090E-04

-1.3308E-04

-6.7928E-05

-6.2288E-05

-2.5101E-05

-1.5604E-05

-1.1059E-05

S2

-5.0227E-05

1.9364E-05

-4.3590E-05

1.3578E-05

-3.3664E-05

-4.1931E-06

-2.5278E-05

S3

5.6546E-05

4.1569E-05

3.4628E-05

2.2293E-05

1.4885E-05

6.2836E-06

2.7754E-06

S4

4.2277E-06

-3.4652E-06

-1.1517E-06

-1.7227E-06

-1.5796E-06

8.5028E-07

5.7535E-07

S5

3.2134E-06

-8.9715E-06

3.7795E-06

5.1825E-07

6.9569E-07

4.4584E-07

-2.5947E-07

S6

1.6660E-05

-1.6225E-05

1.7389E-07

3.3064E-06

-5.7362E-07

2.8252E-06

-1.4724E-06

S7

3.6115E-05

-6.9606E-05

1.6431E-05

-2.3270E-06

-3.4173E-06

1.9164E-06

-4.3198E-06

S8

-1.8562E-04

2.8572E-04

-4.6987E-05

-1.0495E-04

9.7621E-05

-9.8113E-05

-2.3553E-05

S9

-5.0589E-05

-4.1220E-05

1.0572E-04

-3.2375E-05

-7.5056E-06

4.1036E-06

-3.7338E-07

S10

-3.7260E-04

-3.5827E-04

-5.1416E-06

5.6974E-05

8.8123E-05

3.0826E-05

-2.4365E-05

TABLE 6

Fig. 10 shows an on-axis chromatic aberration curve of the optical imaging system of example three, which represents the deviation of the converging focus of light rays of different wavelengths after passing through the optical imaging system. Fig. 11 shows an astigmatism curve of the optical imaging system of example three, which represents meridional image plane curvature and sagittal image plane curvature. Fig. 12 shows a magnification chromatic aberration curve of the optical imaging system of example three, which represents the deviation of different image heights on the imaging plane after light passes through the optical imaging system.

As can be seen from fig. 10 to 12, the optical imaging system according to the third example can achieve good imaging quality.

Example four

As shown in fig. 13 to 16, an optical imaging system of example four of the present application is described. Fig. 13 shows a schematic diagram of the structure of an optical imaging system of example four.

As shown in fig. 13, the optical imaging system includes, in order from the light incident side to the light emergent side, a first lens E1, a stop STO, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a filter E6, and an imaging surface S13.

The first lens element E1 with negative refractive power has a convex surface S1 facing the light incident side and a concave surface S2 facing the light emergent side. The second lens element E2 with negative refractive power has a convex surface on a surface S3 facing the light incident side and a concave surface on a surface S4 facing the light emergent side. The third lens element E3 with negative refractive power has a convex surface S5 facing the light incident side and a concave surface S6 facing the light emergent side. The fourth lens element E4 with positive refractive power has a convex surface S7 facing the light incident side and a convex surface S8 facing the light exiting side. The fifth lens element E5 with negative refractive power has a concave surface on a surface S9 of the fifth lens element facing the light incident side and a concave surface on a surface S10 of the fifth lens element facing the light exiting side. The filter E6 has a surface S11 of the filter facing the light entrance side and a surface S12 of the filter facing the light exit side. Light from the object sequentially passes through the respective surfaces S1 to S12 and is finally imaged on the imaging surface S13.

In the present example, the total effective focal length f of the optical imaging system is 1.10mm, the total length TTL of the optical imaging system is 4.51mm and the image height ImgH is 1.32mm.

Table 7 shows a basic structural parameter table of the optical imaging system of example four, in which the units of radius of curvature, thickness/distance, focal length, and effective radius are all millimeters (mm).

TABLE 7

Table 8 shows the higher order coefficients that can be used for each of the aspherical mirror surfaces in example four, where each of the aspherical surface types can be defined by the formula (1) given in example one above.

TABLE 8

Fig. 14 shows an on-axis chromatic aberration curve of the optical imaging system of example four, which represents the deviation of the converging focus of light rays of different wavelengths after passing through the optical imaging system. Fig. 15 shows an astigmatism curve of the optical imaging system of example four, which represents meridional image plane curvature and sagittal image plane curvature. Fig. 16 shows a magnification chromatic aberration curve of the optical imaging system of example four, which represents deviations of different image heights on an imaging plane after light passes through the optical imaging system.

As can be seen from fig. 14 to 16, the optical imaging system as given in example four can achieve good imaging quality.

Example five

As shown in fig. 17 to 20, an optical imaging system of example five of the present application is described. Fig. 17 shows a schematic diagram of the structure of an optical imaging system of example five.

As shown in fig. 17, the optical imaging system includes, in order from the light incident side to the light emergent side, a first lens E1, a stop STO, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a filter E6, and an imaging surface S13.

The first lens element E1 with negative refractive power has a convex surface S1 facing the light incident side and a concave surface S2 facing the light emergent side. The second lens element E2 with negative refractive power has a convex surface on a surface S3 facing the light incident side and a concave surface on a surface S4 facing the light emergent side. The third lens element E3 with negative refractive power has a concave surface on a light-incident side surface S5 and a concave surface on a light-emergent side surface S6. The fourth lens element E4 with positive refractive power has a convex surface S7 facing the light incident side and a convex surface S8 facing the light exiting side. The fifth lens element E5 with negative refractive power has a concave surface on a surface S9 of the fifth lens element facing the light incident side and a concave surface on a surface S10 of the fifth lens element facing the light exiting side. The filter E6 has a surface S11 of the filter facing the light entrance side and a surface S12 of the filter facing the light exit side. Light from the object sequentially passes through the respective surfaces S1 to S12 and is finally imaged on the imaging surface S13.

In the present example, the total effective focal length f of the optical imaging system is 1.10mm, the total length TTL of the optical imaging system is 4.50mm and the image height ImgH is 1.32mm.

Table 9 shows a basic structural parameter table of the optical imaging system of example five, in which the units of radius of curvature, thickness/distance, focal length, and effective radius are all millimeters (mm).

TABLE 9

Table 10 shows the higher order coefficients that can be used for each of the aspherical mirror surfaces in example five, where each of the aspherical surface types can be defined by equation (1) given in example one above.

Face number

A4

A6

A8

A10

A12

A14

A16

S1

-4.5338E-01

-7.4863E-02

6.4762E-03

-1.2013E-02

-1.1474E-03

-7.6022E-04

-6.8355E-04

S2

6.0206E-02

-2.8398E-02

3.5399E-03

1.8898E-04

-2.8905E-04

-2.2906E-05

7.2296E-05

S3

-1.9966E-02

-9.4993E-04

1.6757E-05

-5.0994E-05

1.2694E-05

-1.0755E-05

5.6641E-06

S4

-8.8930E-02

-3.6509E-03

1.4627E-03

1.7584E-04

4.4851E-05

1.7771E-04

2.4771E-05

S5

-9.5144E-02

-8.6971E-04

2.7405E-03

-2.4617E-03

-6.8975E-04

9.4020E-05

-2.9442E-04

S6

-2.0676E-01

2.2490E-02

-3.4380E-03

1.4156E-03

-7.5379E-04

-1.2044E-05

-4.3191E-06

S7

-3.0611E-01

4.3812E-02

-1.5398E-02

3.9017E-03

-1.9617E-03

6.6351E-04

-2.5410E-04

S8

1.1350E-01

-3.6048E-02

3.9681E-03

-4.2338E-03

1.4135E-03

-6.1802E-04

1.7741E-04

S9

-1.0871E-01

2.4506E-02

3.0556E-03

-2.8431E-03

2.3129E-03

-5.9525E-04

-3.3364E-05

S10

-2.7490E-01

3.2143E-02

-3.9396E-03

-5.2378E-04

6.3428E-04

-9.3287E-05

1.5008E-05

Face number

A18

A20

A22

A24

A26

A28

A30

S1

-1.5607E-04

-7.6966E-05

-5.8814E-05

-2.9231E-05

-1.2006E-05

-1.4376E-05

-1.4994E-05

S2

-3.9252E-05

5.4453E-06

-1.6393E-05

1.6528E-05

-6.8721E-06

7.3057E-06

-2.7786E-06

S3

-5.1022E-06

1.3777E-06

-3.9563E-06

5.0512E-07

-1.0455E-06

1.8903E-06

-2.7973E-07

S4

-4.4581E-05

-1.2742E-04

-1.0755E-04

-8.9779E-05

-4.3083E-05

-1.7904E-05

-2.9356E-07

S5

-2.5239E-04

2.2529E-05

1.4803E-04

9.5694E-05

2.7102E-05

-3.9481E-06

-7.2161E-06

S6

-1.6297E-05

1.9157E-05

-2.6688E-05

2.8812E-06

-1.0493E-05

1.7756E-06

-3.6125E-06

S7

7.8033E-05

-2.7390E-05

1.0316E-05

5.5414E-06

-3.3639E-06

1.7939E-06

-5.4908E-07

S8

-8.5129E-05

-5.2343E-05

8.3278E-05

-2.7098E-05

3.0094E-07

2.4659E-06

7.5870E-08

S9

-2.8307E-05

-2.6745E-05

8.6876E-05

-3.3186E-05

-7.2997E-06

5.2240E-06

-5.4006E-07

S10

-3.2761E-05

-1.4900E-05

1.3743E-05

8.8398E-07

-2.6840E-06

2.6502E-07

1.1877E-07

Table 10

Fig. 18 shows an on-axis chromatic aberration curve of the optical imaging system of example five, which represents the deviation of the converging focus of light rays of different wavelengths after passing through the optical imaging system. Fig. 19 shows an astigmatism curve of the optical imaging system of example five, which represents meridional image plane curvature and sagittal image plane curvature. Fig. 20 shows a magnification chromatic aberration curve of the optical imaging system of example five, which represents the deviation of different image heights on the imaging plane after light passes through the optical imaging system.

As can be seen from fig. 18 to 20, the optical imaging system as given in example five can achieve good imaging quality.

Example six

As shown in fig. 21 to 24, an optical imaging system of example six of the present application is described. Fig. 21 shows a schematic diagram of the structure of an optical imaging system of example six.

As shown in fig. 21, the optical imaging system includes, in order from the light incident side to the light emergent side, a first lens E1, a stop STO, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a filter E6, and an imaging surface S13.

The first lens element E1 with negative refractive power has a convex surface S1 facing the light incident side and a concave surface S2 facing the light emergent side. The second lens element E2 with negative refractive power has a convex surface on a surface S3 facing the light incident side and a concave surface on a surface S4 facing the light emergent side. The third lens element E3 with positive refractive power has a convex surface S5 facing the light incident side and a concave surface S6 facing the light emergent side. The fourth lens element E4 with positive refractive power has a convex surface S7 facing the light incident side and a convex surface S8 facing the light exiting side. The fifth lens element E5 with positive refractive power has a convex surface S9 on the light-incident side and a concave surface S10 on the light-exiting side. The filter E6 has a surface S11 of the filter facing the light entrance side and a surface S12 of the filter facing the light exit side. Light from the object sequentially passes through the respective surfaces S1 to S12 and is finally imaged on the imaging surface S13.

In the present example, the total effective focal length f of the optical imaging system is 0.79mm, the total length TTL of the optical imaging system is 4.08mm and the image height ImgH is 1.32mm.

Table 11 shows a basic structural parameter table of the optical imaging system of example six, in which the units of radius of curvature, thickness/distance, focal length, and effective radius are all millimeters (mm).

TABLE 11

Table 12 shows the higher order coefficients that can be used for each of the aspherical mirror surfaces in example six, where each of the aspherical surface types can be defined by equation (1) given in example one above.

Face number

A4

A6

A8

A10

A12

A14

A16

S1

-4.6735E-01

-7.7723E-02

-2.8952E-03

-3.0771E-03

-7.0848E-03

2.5901E-04

-1.1169E-04

S2

6.0320E-02

-3.4647E-02

-1.2139E-03

4.0930E-03

-8.2327E-04

-1.4349E-03

4.5587E-05

S3

-1.9011E-02

-3.7872E-04

2.2078E-04

1.7176E-04

3.9023E-05

1.0448E-05

1.7512E-05

S4

-8.9902E-02

-6.4874E-04

-6.1676E-04

-8.6467E-05

-1.2862E-04

3.1321E-05

6.9620E-05

S5

-1.0532E-01

6.7708E-03

-7.4499E-04

2.2469E-04

-4.6307E-04

1.4334E-04

1.0518E-04

S6

-1.8588E-01

1.9859E-02

-2.7043E-03

7.0641E-04

-6.9018E-04

1.0681E-05

-1.8000E-04

S7

-2.8931E-01

2.6353E-02

-5.8764E-03

-6.1196E-04

9.4087E-04

-5.3141E-04

7.9969E-05

S8

-1.8495E-02

9.1749E-02

-3.9558E-02

2.2702E-02

-6.0783E-03

-1.5585E-03

2.3221E-03

S9

-1.7879E-01

1.8578E-02

1.9642E-03

-4.1719E-03

2.6769E-03

-8.8400E-04

1.7193E-04

S10

-2.4166E-01

-4.2105E-02

2.0929E-02

-1.8206E-02

9.4981E-03

-2.7188E-03

4.1773E-04

Face number

A18

A20

A22

A24

A26

A28

A30

S1

-2.6349E-04

1.9335E-05

3.2379E-05

4.9431E-05

-3.4405E-05

-3.9057E-05

-1.5748E-05

S2

-4.4713E-05

3.5244E-05

-3.2190E-05

4.2552E-05

8.2713E-06

6.4006E-06

-3.2332E-05

S3

5.4324E-05

6.5493E-05

4.7409E-05

1.8092E-05

-6.1882E-07

-6.8863E-06

-3.3503E-06

S4

1.4207E-05

2.4590E-05

2.4114E-05

3.9300E-05

2.0587E-05

1.1011E-05

-4.0224E-07

S5

1.7460E-05

-7.1694E-05

-3.7169E-05

-1.2230E-05

4.7186E-06

-1.9088E-06

-2.5173E-06

S6

3.2433E-04

-3.7755E-05

8.1464E-05

-6.9392E-05

1.4196E-05

-2.4996E-05

1.2418E-05

S7

4.2314E-05

-3.0381E-04

-6.3507E-05

8.2038E-05

2.4457E-04

1.5460E-04

1.1072E-04

S8

-2.1809E-04

-2.4145E-04

-3.7527E-04

4.5727E-04

2.9353E-04

-1.8232E-04

-1.4774E-04

S9

2.2948E-04

-1.6105E-04

-1.2058E-05

4.4705E-05

9.9684E-06

-3.2166E-05

1.0174E-05

S10

-2.3190E-04

-2.1058E-04

-2.5186E-04

1.1340E-04

2.9110E-04

-1.8640E-04

-4.8238E-05

Table 12

Fig. 22 shows an on-axis chromatic aberration curve of the optical imaging system of example six, which indicates a convergent focus deviation of light rays of different wavelengths after passing through the optical imaging system. Fig. 23 shows an astigmatism curve of the optical imaging system of example six, which represents meridional image plane curvature and sagittal image plane curvature. Fig. 24 shows a magnification chromatic aberration curve of the optical imaging system of example six, which represents deviations of different image heights on an imaging plane after light passes through the optical imaging system.

As can be seen from fig. 22 to 24, the optical imaging system given in example six can achieve good imaging quality.

In summary, examples one to six satisfy the relationships shown in table 13, respectively.

TABLE 13

Table 14 shows the effective focal lengths f of the optical imaging systems of examples one to six, and the effective focal lengths f1 to f5 of the respective lenses.

Example parameters	1	2	3	4	5	6
							f(mm)	1.09	1.03	1.04	1.10	1.10	0.79
f1(mm)	-2.20	-1.57	-1.78	-2.05	-2.12	-1.34
							f2(mm)	-8.54	-59.01	-6.52	-8.53	-8.52	-6.52
f3(mm)	3.64	3.68	3.87	-100.00	-17.45	8.66
							f4(mm)	0.93	0.98	0.96	0.84	0.85	1.03
f5(mm)	-1.24	-1.57	-2.08	-1.28	-1.30	100.00
							TTL(mm)	4.20	4.72	4.39	4.51	4.50	4.08
ImgH(mm)	1.32	1.32	1.32	1.32	1.32	1.32
							Semi-FOV(°)	83.2	84.6	83.5	82.9	82.9	85.1
SAG51(mm)	-0.39	-0.51	-0.14	-0.34	-0.32	-0.10

TABLE 14

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

It will be apparent that the embodiments described above are merely some, but not all, embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the present invention without making any inventive effort, shall fall within the scope of the present invention.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments in accordance with the present application. As used herein, the singular is also intended to include the plural unless the context clearly indicates otherwise, and furthermore, it is to be understood that the terms "comprises" and/or "comprising" when used in this specification are taken to specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof.

It should be noted that the terms "first," "second," and the like in the description and claims of the present application and the above figures are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate such that embodiments of the present application described herein may be implemented in sequences other than those illustrated or described herein.

The above description is only of the preferred embodiments of the present invention and is not intended to limit the present invention, but various modifications and variations can be made to the present invention by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An optical imaging system, characterized in that the optical imaging system has only five lenses, comprising, in order from an light-in side to a light-out side of the optical imaging system:

a first lens with negative refractive power, wherein a surface of the first lens facing the light incident side is a convex surface, and a surface of the first lens facing the light emergent side is a concave surface;

a second lens with negative refractive power, wherein a surface of the second lens facing the light incident side is a convex surface, and a surface of the second lens facing the light emergent side is a concave surface;

A third lens with refractive power, wherein a surface of the third lens facing the light emergent side is a concave surface;

a fourth lens element with positive refractive power having a convex surface on the light-entering side and a convex surface on the light-exiting side;

a fifth lens element with refractive power;

wherein the maximum field angle FOV of the optical imaging system satisfies: 150 degrees < FOV < 175 degrees;

the curvature radius R4 of the surface of the second lens facing the light emergent side and the effective focal length f of the optical imaging system satisfy the following conditions: r4/f is more than 3.0 and less than 6.0;

the curvature radius R7 of the surface of the fourth lens facing the light incident side and the curvature radius R8 of the surface of the fourth lens facing the light emergent side satisfy the following conditions: 3.5 < (R8-R7)/(R8+R7) < 14.0.

2. The optical imaging system according to claim 1, wherein a center thickness CT4 of the fourth lens on the optical axis and an edge thickness ET4 of the fourth lens satisfy: CT4/ET4 is less than 3.5 and less than 5.0.

3. The optical imaging system of claim 1, wherein an effective focal length f of the optical imaging system and an entrance pupil diameter EPD of the optical imaging system satisfy: f/EPD < 2.6.

4. The optical imaging system according to claim 1, wherein an on-axis distance TTL from a surface of the first lens facing the light-incident side to the imaging surface, an air interval T12 on the optical axis between the first lens and the second lens satisfies: TTL/T12 is less than 5.0 and more than 4.0.

5. The optical imaging system of claim 1, wherein an edge thickness ET5 of the fifth lens and a center thickness CT5 of the fifth lens on the optical axis satisfy: ET5/CT5 is less than 1.5 and less than 2.5.

6. The optical imaging system according to claim 1, wherein an on-axis distance SAG51 between an intersection point of an edge thickness ET5 of the fifth lens and a surface of the fifth lens facing the light entrance side and an optical axis to an effective radius vertex of the surface of the fifth lens facing the light entrance side is: -6.5 < ET5/SAG51 < -1.5.

7. The optical imaging system according to claim 1, wherein an on-axis distance SAG42 between a center thickness CT4 of the fourth lens on the optical axis and an intersection point of a surface of the fourth lens facing the light-exiting side and the optical axis to an effective radius vertex of the surface of the fourth lens facing the light-exiting side is: -2.5 < CT4/SAG42 < -1.5.

8. The optical imaging system according to claim 1, wherein a center thickness CT3 of the third lens on the optical axis and a center thickness CT2 of the second lens on the optical axis satisfy: CT3/CT2 is more than 1.0 and less than 2.0.

9. The optical imaging system according to claim 1, wherein an air space T12 between the first lens and the second lens on the optical axis, a center thickness CT1 of the first lens on the optical axis, satisfies: T12/CT1 is more than 3.0 and less than 6.0.

10. The optical imaging system of claim 1, wherein the abbe number V5 of the fifth lens satisfies: v5 is less than 20.0.

11. The optical imaging system according to claim 1, wherein an effective focal length f1 of the first lens, a radius of curvature R1 of a surface of the first lens facing the light entrance side, and a radius of curvature R2 of a surface of the first lens facing the light exit side satisfy: -1.5 < f 1/(R1+R2) < -0.6.