CN114527556B

CN114527556B - Optical pick-up lens group

Info

Publication number: CN114527556B
Application number: CN202210204260.5A
Authority: CN
Inventors: 陈明; 闻人建科; 戴付建; 赵烈烽
Original assignee: Zhejiang Sunny Optics Co Ltd
Current assignee: Zhejiang Sunny Optics Co Ltd
Priority date: 2022-03-02
Filing date: 2022-03-02
Publication date: 2024-05-28
Anticipated expiration: 2042-03-02
Also published as: CN114527556A

Abstract

The invention provides an optical imaging lens group. The optical pick-up lens group comprises five lenses, wherein the lenses are plastic aspheric lenses, air spaces are arranged among the lenses, the lenses are divided into a fixed group and a focusing group, and the fixed group comprises a first lens with optical power, a second lens with optical power and a third lens with optical power; the focusing group comprises a fourth lens with negative focal power and a fifth lens with focal power, and the object side surface of the fourth lens is a concave surface. The invention solves the problem that in the prior art, the lens has difficulty in taking into account clear imaging under long-range and short-range shooting.

Description

Optical pick-up lens group

Technical Field

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

Background

Along with the updating iteration of the mobile phone lens, the mobile phone lens is developed towards the direction of diversification, but the more the requirements on the lens are, the more the lens is required to have the advantages of high performance, small volume, light weight and the like. The traditional image surface focusing lens has the problems that the object distance is large, the micro-distance shooting performance is not ideal, and clear imaging under long-range shooting and short-range shooting is difficult to take into account.

That is, in the prior art, the lens has the problem that it is difficult to achieve clear imaging under both long-range and short-range shooting.

Disclosure of Invention

The invention mainly aims to provide an optical pick-up lens group so as to solve the problem that in the prior art, the lens is difficult to take into account clear imaging under long-range and short-range shooting.

In order to achieve the above object, according to one aspect of the present invention, there is provided an optical imaging lens group including five lenses each of which is a plastic aspherical lens having an air space therebetween, each lens being divided into a fixed group including a first lens having optical power, a second lens having optical power, and a third lens having optical power, an image side surface of the third lens being a convex surface; the focusing group comprises a fourth lens with negative focal power and a fifth lens with focal power, and the object side surface of the fourth lens is a concave surface.

Further, the effective focal length f1 of the first lens and the curvature radius R1 of the object side surface of the first lens satisfy: 1.5 < f1/R1 < 2.0.

Further, the effective focal length f2 of the second lens and the curvature radius R4 of the image side surface of the second lens satisfy: -4.0 < f2/R4 < -1.5.

Further, the effective focal length f4 of the fourth lens and the curvature radius R6 of the image side surface of the third lens satisfy: 2.0 < f4/R6 < 5.0.

Further, the effective focal length f of the optical imaging lens group and the curvature radius R7 of the object side surface of the fourth lens satisfy: -9.0 < f/R7 < -1.0.

Further, the maximum field angle FOV of the optical imaging lens group satisfies: FOV < 25 deg..

Further, the effective focal length f of the optical imaging lens group and the entrance pupil diameter EPD of the optical imaging lens group satisfy: 2.0 < f/EPD < 3.5.

Further, the air interval T23 of the second lens and the third lens on the optical axis of the optical imaging lens group and the center thickness CT2 of the second lens on the optical axis satisfy: T23/CT2 is more than 1.0 and less than 2.5.

Further, the center thickness CT1 of the first lens on the optical axis of the optical imaging lens group and the center thickness CT4 of the fourth lens on the optical axis satisfy: CT1/CT4 is more than 1.0 and less than 6.0.

Further, the center thickness CT2 of the second lens on the optical axis of the optical imaging lens group and the center thickness CT3 of the third lens on the optical axis satisfy: CT3/CT2 is more than 1.0 and less than 3.0.

Further, when the on-axis distance TTL from the object side surface of the first lens element to the imaging surface of the optical imaging lens assembly and the optical imaging lens assembly are at an infinite object distance, the distance BFL (IN) between the image side surface of the fifth lens element and the imaging surface on the optical axis of the optical imaging lens assembly satisfies: 1.5 < TTL/BFL (IN) < 3.5.

Further, at an infinite object distance, a distance SD (IN) from the aperture stop to the image side surface of the fifth lens, and an air interval T34 (IN) between the third lens and the fourth lens on the optical axis of the optical imaging lens set satisfy: 2.0 < SD (IN)/T34 (IN) < 6.0.

Further, when the on-axis distance TTL from the object side surface of the first lens element to the imaging surface of the optical imaging lens assembly and the object distance of the optical imaging lens assembly is 100mm, the distance BFL (M) between the image side surface of the fifth lens element and the imaging surface on the optical axis of the optical imaging lens assembly satisfies: 2.0 < TTL/BFL (M) < 5.5.

Further, at an object distance of 100mm, a distance SD (M) from a stop of the optical imaging lens group to an image side surface of the fifth lens, and an air interval T34 (M) between the third lens and the fourth lens on an optical axis of the optical imaging lens group at the object distance of 100mm are satisfied: 1.0 < SD (M)/T34 (M) < 2.5.

According to another aspect of the present invention, there is provided an optical imaging lens group including five lenses, each of which is a plastic aspherical lens having an air space therebetween, each of which is divided into a fixed group including a first lens having optical power, a second lens having optical power, and a third lens having optical power, and a focusing group; the focusing group comprises a fourth lens with negative focal power and a fifth lens with focal power, the object side surface of the fourth lens is a concave surface, the on-axis distance TTL from the object side surface of the first lens to the imaging surface of the optical imaging lens group, and when the optical imaging lens group is at infinite object distance, the effective focal length f (IN) of the optical imaging lens group is as follows: TTL/f (IN) < 1.1.

By applying the technical scheme of the invention, the optical pick-up lens group comprises five lenses, the lenses are all plastic aspheric lenses, air spaces are arranged among the lenses, the lenses are divided into a fixed group and a focusing group, the fixed group comprises a first lens, a second lens and a third lens, the first lens has optical power, the second lens has optical power, and the third lens has optical power; the focusing group comprises a fourth lens and a fifth lens, wherein the fourth lens has negative focal power, the object side surface of the fourth lens is a concave surface, and the fifth lens has focal power.

Through all setting up the air interval between each lens, can adjust the air interval, make optical pick-up lens group still have better focusing effect under different object distances to make optical pick-up lens group have higher image quality under infinity object distance and microspur, can compromise long-range shooting and microspur shooting's function. The five plastic aspheric lenses are adopted to enable light rays to be better converged on a film plane, the flare phenomenon caused by the reflection of the light rays in the lenses can be avoided, the aberration of the optical imaging lens group can be effectively corrected, the optical imaging lens group has better imaging quality at different object distances, and meanwhile, the plastic lenses have the advantages of light weight, small size and low cost, and are beneficial to miniaturization, portability and low cost of the optical imaging lens group. The low-order aberration of the optical imaging lens group can be effectively balanced through reasonable positive and negative distribution of the focal power of each lens of the optical imaging lens group, the sensitivity of the tolerance of the optical imaging lens group can be reduced, the miniaturization of the optical imaging lens group is kept, and the imaging quality of the optical imaging lens group is ensured.

Drawings

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

fig. 1 is a schematic view showing a structure of an optical imaging lens group according to an example of the present invention in a first object distance state;

Fig. 2 to 5 show an on-axis chromatic aberration curve, an astigmatism curve, a distortion curve, and a magnification chromatic aberration curve, respectively, of the optical imaging lens group in fig. 1;

Fig. 6 is a schematic view showing a structure of an optical imaging lens group according to an example of the present invention in a second distance state;

Fig. 7 to 10 show an on-axis chromatic aberration curve, an astigmatism curve, a distortion curve, and a magnification chromatic aberration curve, respectively, of the optical imaging lens group in fig. 6;

Fig. 11 is a schematic view showing a structure of an optical imaging lens group according to example two of the present invention in a first object distance state;

fig. 12 to 15 show an on-axis chromatic aberration curve, an astigmatism curve, a distortion curve, and a magnification chromatic aberration curve, respectively, of the optical imaging lens group in fig. 11;

fig. 16 is a schematic view showing a structure of an optical imaging lens group according to example two of the present invention in a second object distance state;

fig. 17 to 20 show an on-axis chromatic aberration curve, an astigmatism curve, a distortion curve, and a magnification chromatic aberration curve, respectively, of the optical imaging lens group in fig. 16;

Fig. 21 is a schematic view showing the structure of an optical imaging lens group according to example three of the present invention in a first object distance state;

Fig. 22 to 25 show an on-axis chromatic aberration curve, an astigmatism curve, a distortion curve, and a magnification chromatic aberration curve, respectively, of the optical imaging lens group in fig. 21;

Fig. 26 is a schematic diagram showing the structure of an optical imaging lens group according to example three of the present invention in a second object distance state;

Fig. 27 to 30 show an on-axis chromatic aberration curve, an astigmatism curve, a distortion curve, and a magnification chromatic aberration curve, respectively, of the optical imaging lens group in fig. 26;

fig. 31 is a schematic view showing the structure of an optical imaging lens group according to example four of the present invention in a first object distance state;

Fig. 32 to 35 show an on-axis chromatic aberration curve, an astigmatism curve, a distortion curve, and a magnification chromatic aberration curve, respectively, of the optical imaging lens group in fig. 31;

fig. 36 is a schematic view showing the structure of an optical imaging lens group according to example four of the present invention in a second object distance state;

fig. 37 to 40 show an on-axis chromatic aberration curve, an astigmatism curve, a distortion curve, and a magnification chromatic aberration curve, respectively, of the optical imaging lens group in fig. 36;

fig. 41 is a schematic view showing the structure of an optical imaging lens group according to example five of the present invention in a first object distance state;

Fig. 42 to 45 show an on-axis chromatic aberration curve, an astigmatism curve, a distortion curve, and a magnification chromatic aberration curve, respectively, of the optical imaging lens group in fig. 41;

fig. 46 is a schematic diagram showing the structure of an optical imaging lens group in the second distance state in example five of the present invention;

Fig. 47 to 50 show an on-axis chromatic aberration curve, an astigmatism curve, a distortion curve, and a magnification chromatic aberration curve, respectively, of the optical imaging lens group in fig. 46.

Wherein the above figures include the following reference numerals:

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

Detailed Description

It should be noted that, without conflict, the embodiments of the present application and features of the embodiments may be combined with each other. The application 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 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 in the prior art, the lens has difficulty in taking both long-range and short-range shooting and clearly imaging, the invention mainly aims to provide an optical imaging lens group.

Example 1

As shown in fig. 1 to 50, the optical imaging lens group includes five lenses, each lens is a plastic aspheric lens, each lens has an air space, each lens is divided into a fixed group and a focusing group, the fixed group includes a first lens, a second lens and a third lens, the first lens has optical power, the second lens has optical power, and the third lens has optical power; the focusing group comprises a fourth lens and a fifth lens, wherein the fourth lens has negative focal power, the object side surface of the fourth lens is a concave surface, and the fifth lens has focal power.

In the present embodiment, the effective focal length f1 of the first lens and the radius of curvature R1 of the object side surface of the first lens satisfy: 1.5 < f1/R1 < 2.0. The ratio of the effective focal length of the first lens to the curvature radius of the object side surface of the first lens is reasonably controlled, so that the deflection degree of light rays in the first lens can be effectively reduced, the sensitivity of the lens is reduced, the tolerance risk of the optical imaging lens group is reduced, the spherical aberration generated by the first lens can be reduced, and the optical imaging lens group has higher resolution. Preferably, 1.6 < f1/R1 < 1.95.

In the present embodiment, the effective focal length f2 of the second lens and the curvature radius R4 of the image side surface of the second lens satisfy: -4.0 < f2/R4 < -1.5. Through reasonable regulation and control of the ratio of the effective focal length of the second lens to the curvature radius of the heating image side surface of the second lens, the overgreat sagittal height of the second lens can be avoided, the processing manufacturability of the optical pick-up lens group can be improved, the deflection angle of light rays in the second lens can be reduced, the sensitivity of the second lens is reduced, and the astigmatism and the distortion generated by the second lens can be reduced. Preferably, -3.95 < f2/R4 < -2.

In the present embodiment, the effective focal length f4 of the fourth lens and the curvature radius R6 of the image side surface of the third lens satisfy: 2.0 < f4/R6 < 5.0. The effective focal length of the fourth lens and the curvature radius of the image side surface of the third lens are reasonably distributed, so that the curvature radius of the image side surface of the third lens can be effectively controlled, the process sensitivity of the third lens is reduced, the risk existing in processing and forming is reduced, the sagittal height of the third lens is controlled within a reasonable range, the deflection of light rays in the fourth lens can be slowed down, the sensitivity of the third lens is effectively reduced, meanwhile, the convergence of the light rays is facilitated, and the total reflection on the surface of the third lens and the generation of ghost images are avoided. Preferably, 2.1 < f4/R6 < 4.95.

In the present embodiment, the effective focal length f of the optical imaging lens group and the radius of curvature R7 of the object side surface of the fourth lens element satisfy: -9.0 < f/R7 < -1.0. The ratio of the effective focal length of the optical imaging lens group to the curvature radius of the object side surface of the fourth lens is reasonably controlled, so that the processing opening angle of the fourth lens is kept in a reasonable processing range, the surface shape of the fourth lens is smoother, chromatic aberration and image field bending of the optical imaging lens group can be balanced better, and the fourth lens has larger focal power due to the condition, so that the total length of the optical imaging lens group can be controlled favorably. Preferably, -8.8 < f/R7 < -1.5.

In the present embodiment, the maximum field angle FOV of the optical imaging lens group satisfies: FOV < 25 deg.. The imaging range of the optical imaging lens group can be effectively controlled by reasonably controlling the maximum field angle of the optical imaging lens group, so that the optical imaging lens group can accurately acquire an optical signal of an object side, and the optical imaging lens group is ensured to have higher resolution and better imaging quality.

In the present embodiment, the effective focal length f of the optical imaging lens group and the entrance pupil diameter EPD of the optical imaging lens group satisfy: 2.0 < f/EPD < 3.5. The optical focal length and the size of the entrance pupil diameter of the optical imaging lens group are reasonably distributed by reasonably regulating and controlling the ratio of the effective focal length of the optical imaging lens group to the entrance pupil diameter of the optical imaging lens group, so that the optical imaging lens group has a reasonable F number while having a small size, the optical imaging lens group has a good light collecting capability, the optical imaging lens group has a high resolution, and the imaging quality of the optical imaging lens group is ensured. Preferably, 2.5 < f/EPD < 3.5.

In the present embodiment, the air interval T23 of the second lens and the third lens on the optical axis of the optical imaging lens group and the center thickness CT2 of the second lens on the optical axis satisfy: T23/CT2 is more than 1.0 and less than 2.5. The ratio of the air interval of the second lens and the third lens on the optical axis to the center thickness of the second lens on the optical axis is reasonably adjusted. The deflection angles of light rays on the second lens and the third lens can be effectively reduced, ghost image energy between the two lenses can be reduced, and meanwhile, optical distortion of the optical imaging lens group can be well reduced, so that imaging quality of the optical imaging lens group is improved. Preferably, 1.3 < T23/CT2 < 2.3.

In the present embodiment, the center thickness CT1 of the first lens on the optical axis of the optical imaging lens group and the center thickness CT4 of the fourth lens on the optical axis satisfy: CT1/CT4 is more than 1.0 and less than 6.0. The central thickness of the first lens and the fourth lens on the optical axis is reasonably distributed, so that the optical imaging lens group is guaranteed to have good uniformity, the sensitivity of the lens thickness is reduced, and the field curvature of the optical imaging lens group is balanced. Preferably, 1.1 < CT1/CT4 < 5.8.

In the present embodiment, the center thickness CT2 of the second lens on the optical axis of the optical imaging lens group and the center thickness CT3 of the third lens on the optical axis satisfy: CT3/CT2 is more than 1.0 and less than 3.0. The central thicknesses of the second lens and the third lens on the optical axis are reasonably restrained, so that the distortion of the optical imaging lens group can be balanced well, meanwhile, the assembly difficulty of the two lenses is reduced, and the formability and the processing manufacturability of the optical imaging lens group are improved. Preferably, 1.0 < CT3/CT2 < 2.5.

IN this embodiment, when the on-axis distance TTL from the object side surface of the first lens element to the imaging surface of the optical imaging lens assembly and the optical imaging lens assembly are at an infinite object distance, the distance BFL (IN) between the image side surface of the fifth lens element and the imaging surface on the optical axis of the optical imaging lens assembly satisfies: 1.5 < TTL/BFL (IN) < 3.5. By reasonably regulating and controlling the ratio of the distance from the object side surface of the first lens to the imaging surface on the axis to the distance from the image side surface of the last lens to the imaging surface on the optical axis under the infinite object distance, the situation that the total length of the optical imaging lens group continuously increases along with the rear focal length can be avoided, the total length of the optical imaging lens group is avoided to be too long, the rear focal length of the optical imaging lens group is not too short, the ultrathin and compact optical imaging lens group can be realized, and the space utilization rate of the optical imaging lens group is improved. Preferably 1.6 < TTL/BFL (IN) < 3.5.

IN the present embodiment, at an infinitely distant object distance, the distance SD (IN) from the aperture stop to the image side surface of the fifth lens, and at an infinitely distant object distance, the air interval T34 (IN) between the third lens and the fourth lens on the optical axis of the optical imaging lens set satisfy: 2.0 < SD (IN)/T34 (IN) < 6.0. The distance from the diaphragm to the image side surface of the last lens and the air interval between the third lens and the fourth lens are reasonably regulated and controlled when the object distance is infinitely long, so that the total length of the optical imaging lens group is favorably controlled, the miniaturization and the portability of the optical imaging lens group are ensured, meanwhile, the distortion and the chromatic aberration of the object distance can be reduced, the optical imaging lens group has better imaging quality at the object distance, the processing manufacturability of the optical imaging lens group is favorably improved, and the yield of the optical imaging lens group is improved. Preferably, 2.2 < SD (IN)/T34 (IN) < 5.3.

In this embodiment, the on-axis distance TTL from the object side surface of the first lens element to the imaging surface of the optical imaging lens assembly, and the distance BFL (M) from the image side surface of the fifth lens element to the imaging surface on the optical axis of the optical imaging lens assembly when the object distance of the optical imaging lens assembly is 100mm satisfy: 2.0 < TTL/BFL (M) < 5.5. By reasonably regulating and controlling the distance from the object side surface of the first lens to the imaging surface and the distance from the image side surface of the fifth lens to the imaging surface on the optical axis under the object distance of 100mm, the situation that the total length of the optical imaging lens group continuously increases along with the rear focal length can be avoided when the rear focal length increases, the total length of the optical imaging lens group is avoided to be too long, the rear focal length of the optical imaging lens group is not too short, the miniaturization and the compactness of the appearance of the optical imaging lens group are facilitated, and the module suitability and the practicability of the optical imaging lens group are improved. Preferably, 2.0 < TTL/BFL (M) < 5.3.

In the present embodiment, the distance SD (M) from the stop of the optical imaging lens group to the image side surface of the fifth lens at the object distance of 100mm, and the air interval T34 (M) between the third lens and the fourth lens on the optical axis of the optical imaging lens group at the object distance of 100mm are satisfied: 1.0 < SD (M)/T34 (M) < 2.5. The distance from the diaphragm to the image side surface of the fifth lens and the air interval between the third lens and the fourth lens are reasonably regulated and controlled when the object distance is 100mm, so that the total length of the optical imaging lens group is favorably controlled, the miniaturization and the portability of the optical imaging lens group are ensured, meanwhile, the distortion and the chromatic aberration of the object distance can be reduced, and the optical imaging lens group has better imaging quality under the object distance. Preferably, 1.1 < SD (M)/T34 (M) < 2.1.

Example two

As shown in fig. 1 to 50, the optical imaging lens group includes five lenses, each lens is a plastic aspheric lens, each lens has an air space therebetween, each lens is divided into a fixed group and a focusing group, the fixed group includes a first lens, a second lens and a third lens, the first lens has optical power, the second lens has optical power, and the third lens has optical power; the focusing group comprises a fourth lens and a fifth lens, the fourth lens has negative focal power, the object side surface of the fourth lens is a concave surface, the fifth lens has focal power, the on-axis distance TTL from the object side surface of the first lens to the imaging surface of the optical imaging lens group, and when the optical imaging lens group is at infinite object distance, the effective focal length f (IN) of the optical imaging lens group is as follows: TTL/f (IN) < 1.1.

Through all setting up the air interval between each lens, can adjust the air interval, make optical pick-up lens group still have better focusing effect under different object distances to make optical pick-up lens group have higher image quality under infinity object distance and microspur, can compromise long-range shooting and microspur shooting's function. The five plastic aspheric lenses are adopted to enable light rays to be better converged on a film plane, the flare phenomenon caused by the reflection of the light rays in the lenses can be avoided, the aberration of the optical imaging lens group can be effectively corrected, the optical imaging lens group has better imaging quality at different object distances, and meanwhile, the plastic lenses have the advantages of light weight, small size and low cost, and are beneficial to miniaturization, portability and low cost of the optical imaging lens group. The low-order aberration of the optical imaging lens group can be effectively balanced through reasonable positive and negative distribution of the focal power of each lens of the optical imaging lens group, the sensitivity of the tolerance of the optical imaging lens group can be reduced, the miniaturization of the optical imaging lens group is kept, and the imaging quality of the optical imaging lens group is ensured. By reasonably regulating and controlling the on-axis distance from the object side surface of the first lens to the imaging surface and the effective focal length of the optical imaging lens group under infinite object distance, the situation that the total length of the optical imaging lens group continuously increases along with the effective focal length when the effective focal length increases can be avoided, the optical imaging lens group has a longer focal length and a shorter total length, so that the optical imaging lens group has a better control force on a local picture and a smaller appearance, and the practicability of the optical imaging lens group is ensured.

Preferably, the on-axis distance TTL from the object side surface of the first lens element to the imaging surface of the optical imaging lens group, when the optical imaging lens group is at an infinite object distance, the effective focal length f (IN) of the optical imaging lens group is as follows: TTL/f (IN) is less than 0.7 and less than 1.1.

In the present embodiment, the effective focal length f4 of the fourth lens and the curvature radius R6 of the image side surface of the third lens satisfy: 2.0 < f4/R6 < 5.0. The effective focal length of the fourth lens and the curvature radius of the image side surface of the third lens are reasonably distributed, so that the size of the curvature radius of the image side surface of the third lens can be effectively ensured, the process sensitivity of the third lens is reduced, the risk existing in processing and forming is reduced, the sagittal height of the third lens is controlled within a reasonable range, the deflection of light rays in the fourth lens can be slowed down, the sensitivity of the third lens is effectively reduced, meanwhile, the convergence of the light rays is facilitated, and the total reflection on the surface of the third lens and the generation of ghost images are avoided. Preferably, 2.1 < f4/R6 < 4.95.

In the present embodiment, the effective focal length f of the optical imaging lens group and the radius of curvature R7 of the object side surface of the fourth lens element satisfy: -9.0 < f/R7 < -1.0. The ratio of the effective focal length of the optical imaging lens group to the curvature radius of the object side surface of the fourth lens is reasonably controlled, so that the processing opening angle of the fourth lens is kept in a reasonable processing range, the surface shape of the fourth lens is smoother, chromatic aberration and image field bending of the optical imaging lens group can be well balanced, and the fourth lens has larger focal power due to the condition, so that the total length of the optical imaging lens group can be controlled. Preferably, -8.8 < f/R7 < -1.5.

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

The optical imaging lens group in the present application may employ a plurality of lenses, for example, the above-described five lenses. By reasonably distributing the focal power, the surface shape, the center thickness of each lens, the axial distance between each lens and the like of each lens, the imaging quality of the optical imaging lens group can be effectively increased, the sensitivity of the optical imaging lens group is reduced, and the processability of the optical imaging lens group is improved, so that the optical imaging lens group 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 mirror surfaces of each lens is an aspherical mirror surface. 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, it will be appreciated by those skilled in the art that the number of lenses constituting the optical imaging lens group can be changed to achieve the respective results and advantages described in the present specification without departing from the technical solution claimed in the present application. For example, although the description has been made by taking five lenses as an example in the embodiment, the optical imaging lens group is not limited to include five lenses. The optical imaging lens group may further include other numbers of lenses, if necessary.

Examples of specific surface types and parameters applicable to the optical imaging lens group 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 five is applicable to all embodiments of the present application.

Example one

As shown in fig. 1 to 10, an optical imaging lens group according to an example of the present application is described. Fig. 1 is a schematic diagram showing a structure of an optical imaging lens group of example one in a first object distance state, and fig. 6 is a schematic diagram showing a structure of an optical imaging lens group of example one in a second object distance state.

As shown in fig. 1 and 6, the optical imaging lens assembly includes, in order from an object side to an image side: a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a filter E6, and an imaging plane S13.

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

In this example, the image height ImgH of the optical imaging lens group is 3.47mm. The total length TTL of the optical imaging lens group is 18.03mm.

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

TABLE 1

Table 2 shows partial parameters of the optical imaging lens group of example one in the first object distance state and the second object distance state.

Parameters (parameters)	First object distance state	Second object distance state
			OBJ(mm)	Infinity (IN)	100(M)
Semi-FOV(°)	10.7	10.2
			f/EPD	3.30	3.39
f(mm)	18.20	14.75
			T34(mm)	1.87	5.39
BFL(mm)	5.22	8.73

TABLE 2

The parameter in the first object distance state and the second object distance state are not indicated, and the parameter is the same in both states.

In the first example, the object side surface and the image side surface of any one of the first lens element E1 to the fifth lens element E5 are aspheric, and the surface shape of each aspheric lens element can be defined by, but not limited to, the following aspheric 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 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 are given in Table 3 below.

Face number

A4

A6

A8

A10

A12

A14

A16

S1

-6.9192E-02

-1.9525E-02

-3.4648E-03

-6.5309E-04

-3.2917E-04

-4.1115E-05

-3.0804E-05

S2

3.7393E-02

-1.8857E-02

-2.1863E-03

4.7869E-04

-2.4798E-03

1.0160E-03

-9.6113E-04

S3

-5.2907E-01

5.4939E-02

-6.6922E-03

1.3890E-03

-2.0145E-03

1.0563E-03

-8.8946E-04

S4

-2.4637E-01

1.9266E-02

-1.3854E-03

-1.8379E-03

-9.0182E-04

-5.3242E-04

-5.8397E-04

S5

-1.6571E-01

-2.3648E-03

2.8417E-03

-8.8803E-05

8.4930E-05

-5.9161E-06

-8.1383E-05

S6

-3.0914E-02

1.0005E-02

3.3776E-03

7.3845E-04

6.2062E-04

5.1112E-04

4.8668E-04

S7

2.1297E-01

-1.9991E-02

2.5251E-03

-2.9124E-04

2.3468E-05

-8.6916E-06

1.2496E-05

S8

3.3808E-01

-1.0437E-02

-4.0875E-03

3.2732E-03

-1.6149E-03

7.7111E-04

-2.9668E-04

S9

-2.2581E-01

-4.6112E-03

1.7014E-03

-9.1607E-04

2.2561E-04

-1.2154E-04

7.3941E-05

S10

-5.3253E-01

-1.6356E-03

-2.8440E-02

-1.9688E-02

-1.8519E-02

-1.4333E-02

-1.0630E-02

Face number

A18

A20

A22

A24

A26

A28

A30

S1

-7.8506E-06

-1.8692E-05

-4.0401E-06

-9.8893E-07

-1.5596E-06

2.3419E-06

-8.4489E-07

S2

4.8985E-04

-4.4828E-04

3.9677E-04

-2.1416E-04

8.7759E-05

-1.5153E-05

-1.4265E-06

S3

4.8462E-04

-5.2036E-04

3.8219E-04

-1.6215E-04

2.4643E-05

1.7175E-05

-8.6437E-06

S4

-8.1620E-05

-1.7781E-04

1.6579E-04

-4.4171E-05

1.9000E-05

2.8011E-05

-1.6169E-06

S5

-1.6616E-05

-7.2812E-05

2.7044E-05

-4.5915E-06

-7.2880E-06

2.7302E-06

4.2447E-06

S6

4.5985E-04

3.5988E-04

2.8404E-04

1.6112E-04

9.8527E-05

4.8324E-05

1.5697E-05

S7

-8.5896E-06

3.0174E-06

-4.7055E-07

3.5815E-07

-7.9515E-07

4.3859E-07

-7.0727E-08

S8

1.3212E-04

-7.2828E-05

7.9724E-06

-3.5743E-05

-2.7695E-06

-8.7810E-06

4.7625E-07

S9

-3.4964E-06

3.1124E-05

6.1309E-06

-2.6451E-06

-1.6766E-06

-3.2921E-06

-4.8120E-07

S10

-6.9785E-03

-4.0474E-03

-2.0093E-03

-8.0940E-04

-2.4515E-04

-4.9203E-05

0.0000E+00

TABLE 3 Table 3

Fig. 2 shows an on-axis chromatic aberration curve of the optical imaging lens group in the first object distance state, which indicates a convergent focus deviation of light rays of different wavelengths after passing through the optical imaging lens group. Fig. 3 shows an astigmatism curve of the optical imaging lens group of example one in a first object distance state, which indicates a meridional image plane curvature and a sagittal image plane curvature. Fig. 4 shows a distortion curve of the optical imaging lens group of example one in the first object distance state, which represents distortion magnitude values corresponding to different angles of view. Fig. 5 shows a magnification chromatic aberration curve of the optical imaging lens group in the first object distance state of example one, which represents the deviation of different image heights on the imaging plane after light passes through the optical imaging lens group.

Fig. 7 shows an on-axis chromatic aberration curve of the optical imaging lens group in the second object distance state of example one, which indicates a convergence focus deviation of light rays of different wavelengths after passing through the optical imaging lens group. Fig. 8 shows an astigmatism curve of the optical imaging lens group in the second object distance state of example one, which indicates meridional image plane curvature and sagittal image plane curvature. Fig. 9 shows a distortion curve of the optical imaging lens group in the second object distance state of example one, which represents distortion magnitude values corresponding to different angles of view. Fig. 10 shows a magnification chromatic aberration curve of the optical imaging lens group in the second object distance state of example one, which represents the deviation of different image heights on the imaging plane after the light passes through the optical imaging lens group.

As can be seen from fig. 3 to 5 and fig. 7 to 10, the optical imaging lens assembly according to the first example can achieve good imaging quality.

Example two

As shown in fig. 11 to 20, an optical imaging lens group of an 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. 11 is a schematic diagram showing a structure of the optical imaging lens group of the second example in the first object distance state, and fig. 16 is a schematic diagram showing a structure of the optical imaging lens group of the second example in the second object distance state.

As shown in fig. 11 and 16, the optical imaging lens assembly includes, in order from an object side to an image side: a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a filter E6, and an imaging plane S13.

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

In this example, the image height ImgH of the optical imaging lens group is 3.47mm. The total length TTL of the optical imaging lens group is 18.42mm.

Table 4 shows a basic structural parameter table of an optical imaging lens group of example two, in which the units of radius of curvature, thickness/distance, and focal length are all millimeters (mm).

TABLE 4 Table 4

Table 5 shows partial parameters of the optical imaging lens group of example two in the first object distance state and the second object distance state.

Parameters (parameters)	First object distance state	Second object distance state
			OBJ(mm)	Infinity (IN)	100(M)
Semi-FOV(°)	10.7	10.3
			f/EPD	3.30	3.39
f(mm)	18.20	14.73
			T34(mm)	1.61	4.64
BFL(mm)	10.12	8.25

TABLE 5

Table 6 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

-6.0384E-02

-2.4228E-02

-2.1966E-03

-1.9512E-04

-2.9594E-04

-3.9562E-05

-8.0753E-05

S2

3.4524E-02

-2.0633E-02

6.7592E-03

4.9031E-04

-2.4051E-03

7.5372E-04

-8.8391E-04

S3

-5.4304E-01

6.6869E-02

-1.0629E-03

2.0621E-03

-1.9512E-03

1.1899E-03

-1.0343E-03

S4

-2.5682E-01

2.7683E-02

3.6932E-03

8.8257E-05

-1.5072E-04

4.2287E-04

-4.3860E-04

S5

-1.1767E-01

9.4563E-03

7.9540E-03

8.1957E-04

3.1132E-04

1.0415E-04

-4.7896E-05

S6

-3.6482E-03

8.9398E-03

2.0768E-03

3.5646E-04

1.4334E-04

4.2947E-05

-2.4035E-05

S7

1.9518E-01

-1.7991E-02

2.5139E-03

-4.3418E-04

1.0351E-04

-3.2830E-05

1.5130E-05

S8

3.5431E-01

-3.0556E-02

4.1300E-03

-2.8649E-03

4.5246E-04

-9.0955E-04

2.9985E-04

S9

-2.7178E-01

-1.0004E-02

-4.8299E-03

-4.2630E-03

-6.8532E-04

-1.4826E-03

-8.3980E-05

S10

-6.0947E-01

5.2085E-03

-2.1329E-02

-1.1240E-03

-2.1977E-03

-9.1829E-04

-8.8162E-04

Face number

A18

A20

A22

A24

A26

A28

A30

S1

7.9561E-06

8.0968E-06

2.0642E-05

3.1554E-07

-4.9640E-06

2.6678E-06

-2.5887E-06

S2

6.0963E-04

-2.0623E-04

1.9630E-04

-1.6931E-04

6.4665E-05

-1.9090E-05

-1.8608E-06

S3

4.8472E-04

-2.4288E-04

2.2224E-04

-1.3561E-04

3.7542E-05

2.8468E-06

-3.2147E-06

S4

1.5254E-04

-8.5667E-05

1.0313E-04

-5.7883E-05

1.5316E-05

-3.3855E-06

1.0369E-06

S5

1.6695E-04

1.0495E-04

6.5269E-05

6.9403E-06

3.5959E-05

1.3772E-05

6.8644E-06

S6

3.3293E-05

1.6117E-05

1.6158E-05

7.9782E-07

1.2725E-05

4.1404E-06

6.8852E-06

S7

-8.6407E-06

3.7588E-06

-6.6291E-07

2.6775E-07

-7.7982E-07

4.4559E-07

-7.2197E-08

S8

-3.3551E-04

4.7173E-05

-1.9125E-04

-5.1849E-05

-8.1667E-05

-2.1822E-05

-1.6742E-05

S9

-6.3907E-04

-2.2603E-04

-4.0847E-04

-1.9032E-04

-1.5720E-04

-5.1650E-05

-2.5500E-05

S10

-4.8547E-04

4.3865E-05

2.1678E-04

1.9468E-04

6.4523E-05

1.3730E-05

0.0000E+00

TABLE 6

Fig. 12 shows an on-axis chromatic aberration curve of the optical imaging lens group of example two in the first object distance state, which indicates a convergent focus deviation of light rays of different wavelengths after passing through the optical imaging lens group. Fig. 13 shows an astigmatism curve of the optical imaging lens group of example two in the first object distance state, which indicates a meridional image plane curvature and a sagittal image plane curvature. Fig. 14 shows a distortion curve of the optical imaging lens group of example two in the first object distance state, which represents distortion magnitude values corresponding to different angles of view. Fig. 15 shows a magnification chromatic aberration curve of the optical imaging lens group in the first object distance state of example two, which represents the deviation of different image heights on the imaging plane after light passes through the optical imaging lens group.

Fig. 17 shows an on-axis chromatic aberration curve of the optical imaging lens group in the second object distance state of example two, which indicates a convergence focus deviation of light rays of different wavelengths after passing through the optical imaging lens group. Fig. 18 shows an astigmatism curve of the optical imaging lens group in the second object distance state of example two, which indicates meridional image plane curvature and sagittal image plane curvature. Fig. 19 shows a distortion curve of the optical imaging lens group of example two in the second object distance state, which represents distortion magnitude values corresponding to different angles of view. Fig. 20 shows a magnification chromatic aberration curve of the optical imaging lens group in the second object distance state of example two, which represents the deviation of different image heights on the imaging plane after light passes through the optical imaging lens group.

As can be seen from fig. 13 to 15 and fig. 17 to 20, the optical imaging lens group provided in example two can achieve good imaging quality.

Example three

As shown in fig. 21 to 30, an optical imaging lens group of example three of the present application is described. Fig. 21 shows a schematic configuration of the optical imaging lens group of the third example in the first object distance state, and fig. 26 shows a schematic configuration of the optical imaging lens group of the third example in the second object distance state.

As shown in fig. 21 and 26, the optical imaging lens assembly includes, in order from an object side to an image side: a first lens E1, a second lens E2, a stop STO, a third lens E3, a fourth lens E4, a fifth lens E5, a filter E6, and an imaging plane S13.

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

In this example, the image height ImgH of the optical imaging lens group is 3.47mm. The total length TTL of the optical imaging lens group is 18.12mm.

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

TABLE 7

Table 8 shows partial parameters of the optical imaging lens group of example three in the first object distance state and the second object distance state.

Parameters (parameters)	First object distance state	Second object distance state
			OBJ(mm)	Infinity (IN)	100(M)
Semi-FOV(°)	10.7	10.3
			f/EPD	3.30	3.39
f(mm)	18.20	14.61
			T34(mm)	2.19	6.26
BFL(mm)	9.52	5.44

TABLE 8

Table 9 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

-6.9749E-02

-2.1256E-02

-4.2826E-03

-6.9979E-04

-3.7680E-04

-3.8100E-05

-3.3442E-05

S2

2.4156E-02

-1.7532E-02

-2.3112E-03

1.3625E-03

-2.0271E-03

1.1656E-03

-7.2300E-04

S3

-5.2671E-01

5.5530E-02

-6.4361E-03

1.5442E-03

-1.7559E-03

1.0866E-03

-7.2453E-04

S4

-2.4962E-01

2.0831E-02

-1.0922E-03

-9.6080E-04

-1.7220E-04

1.5627E-04

-1.3404E-04

S5

-1.5905E-01

-4.6008E-03

2.2289E-03

-3.9280E-04

-1.3643E-05

8.8056E-06

-2.8139E-06

S6

-3.3433E-02

6.8880E-03

3.0457E-03

6.5777E-04

7.4027E-04

6.0086E-04

5.0900E-04

S7

2.0408E-01

-1.7797E-02

2.2905E-03

-4.4055E-04

1.2558E-04

-6.1919E-05

3.1100E-05

S8

3.4385E-01

-2.0550E-02

-4.3539E-05

3.5605E-04

-2.5488E-04

9.4521E-05

4.0005E-05

S9

-2.3276E-01

-1.4393E-02

4.7152E-03

-3.7267E-03

1.4848E-03

-7.9340E-04

3.8952E-04

S10

-6.3964E-01

2.2285E-03

-3.7906E-02

-2.3980E-02

-2.6639E-02

-2.3664E-02

-1.9036E-02

Face number

A18

A20

A22

A24

A26

A28

A30

S1

1.4950E-05

-5.7628E-06

5.2150E-06

-7.2129E-06

-3.0807E-06

4.3568E-06

-1.1898E-06

S2

5.8681E-04

-4.6371E-04

3.2451E-04

-2.3561E-04

1.1333E-04

-2.0710E-05

-7.6387E-07

S3

6.1980E-04

-4.8282E-04

3.3356E-04

-1.9318E-04

5.0462E-05

1.0239E-05

-6.1182E-06

S4

1.5145E-04

-1.5272E-04

9.8505E-05

-5.8808E-05

9.6264E-06

1.1004E-05

6.5962E-07

S5

2.6945E-05

-2.9433E-05

1.2299E-05

-1.9113E-06

2.3151E-06

6.6763E-06

9.8072E-07

S6

4.0773E-04

2.9811E-04

2.2300E-04

1.2773E-04

6.9843E-05

3.1236E-05

7.0437E-06

S7

-1.0560E-05

2.1513E-06

-4.1531E-07

4.0730E-07

-7.8229E-07

4.3922E-07

-7.1627E-08

S8

1.9350E-05

7.4630E-06

2.0166E-05

-3.4268E-07

4.0102E-06

-2.1642E-06

-1.3946E-06

S9

-1.6615E-04

8.0233E-05

-1.6474E-05

1.9597E-05

-2.6162E-06

1.8099E-06

-1.8490E-06

S10

-1.3465E-02

-8.0411E-03

-4.1151E-03

-1.6469E-03

-4.7939E-04

-7.5005E-05

0.0000E+00

TABLE 9

Fig. 22 shows an on-axis chromatic aberration curve of the optical imaging lens group of example three in the first object distance state, which indicates a convergent focus deviation of light rays of different wavelengths after passing through the optical imaging lens group. Fig. 23 shows an astigmatism curve of the optical imaging lens group of example three in the first object distance state, which indicates a meridional image plane curvature and a sagittal image plane curvature. Fig. 24 shows a distortion curve of the optical imaging lens group of example three in the first object distance state, which represents distortion magnitude values corresponding to different angles of view. Fig. 25 shows a magnification chromatic aberration curve of the optical imaging lens group in the first object distance state of example three, which represents the deviation of different image heights on the imaging plane after light passes through the optical imaging lens group.

Fig. 27 shows an on-axis chromatic aberration curve of the optical imaging lens group in the second object distance state of example three, which indicates a convergent focus deviation of light rays of different wavelengths after passing through the optical imaging lens group. Fig. 28 shows an astigmatism curve of the optical imaging lens group in the second object distance state of example three, which indicates meridional image plane curvature and sagittal image plane curvature. Fig. 29 shows a distortion curve of the optical imaging lens group of example three in the second object distance state, which represents distortion magnitude values corresponding to different angles of view. Fig. 30 shows a magnification chromatic aberration curve of the optical imaging lens group in the second object distance state of example three, which represents the deviation of different image heights on the imaging plane after light passes through the optical imaging lens group.

As can be seen from fig. 23 to 25 and fig. 27 to 30, the optical imaging lens group given in example three can achieve good imaging quality.

Example four

As shown in fig. 31 to 40, an optical imaging lens group of example four of the present application is described. Fig. 31 is a schematic diagram showing the structure of the optical imaging lens group of the fourth example in the first object distance state, and fig. 36 is a schematic diagram showing the structure of the optical imaging lens group of the fourth example in the second object distance state.

As shown in fig. 31 and 36, the optical imaging lens assembly includes, in order from an object side to an image side: a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a filter E6, and an imaging plane S13.

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

In this example, the image height ImgH of the optical imaging lens group is 3.47mm. The total length TTL of the optical imaging lens group was 18.07mm.

Table 10 shows a basic structural parameter table of an optical imaging lens group of example four, in which the units of radius of curvature, thickness/distance, and focal length are all millimeters (mm).

Table 10

Table 11 shows partial parameters of the optical imaging lens group of example four in the first object distance state and the second object distance state.

Parameters (parameters)	First object distance state	Second object distance state
			OBJ(mm)	Infinity (IN)	100(M)
Semi-FOV(°)	10.7	10.4
			f/EPD	3.30	3.39
f(mm)	18.25	14.44
			T34(mm)	1.34	4.52
BFL(mm)	9.53	6.35

TABLE 11

Table 12 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 equation (1) given in example one above.

Table 12

Fig. 32 shows an on-axis chromatic aberration curve of the optical imaging lens group of example four in the first object distance state, which indicates a convergent focus deviation of light rays of different wavelengths after passing through the optical imaging lens group. Fig. 33 shows an astigmatism curve of the optical imaging lens group of example four in the first object distance state, which indicates a meridional image plane curvature and a sagittal image plane curvature. Fig. 34 shows a distortion curve of the optical imaging lens group of example four in the first object distance state, which represents distortion magnitude values corresponding to different angles of view. Fig. 35 shows a magnification chromatic aberration curve of the optical imaging lens group of example four in the first object distance state, which represents the deviation of different image heights on the imaging plane after light passes through the optical imaging lens group.

Fig. 37 shows an on-axis chromatic aberration curve of the optical imaging lens group in the second object distance state of example four, which indicates a convergent focus deviation of light rays of different wavelengths after passing through the optical imaging lens group. Fig. 38 shows an astigmatism curve of the optical imaging lens group in the second object distance state of example four, which indicates meridional image plane curvature and sagittal image plane curvature. Fig. 39 shows a distortion curve of the optical imaging lens group of example four in the second object distance state, which represents distortion magnitude values corresponding to different angles of view. Fig. 40 shows a magnification chromatic aberration curve of the optical imaging lens group in the second object distance state of example four, which represents the deviation of different image heights on the imaging plane after light passes through the optical imaging lens group.

As can be seen from fig. 33 to 35 and fig. 37 to 40, the optical imaging lens group given in example four can achieve good imaging quality.

Example five

As shown in fig. 41 to 50, an optical imaging lens group of example five of the present application is described. Fig. 41 is a schematic diagram showing the structure of the optical imaging lens group of example five in the first object distance state, and fig. 46 is a schematic diagram showing the structure of the optical imaging lens group of example five in the second object distance state.

As shown in fig. 41 and 46, the optical imaging lens group includes, in order from an object side to an image side: a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a filter E6, and an imaging plane S13.

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

In this example, the image height ImgH of the optical imaging lens group is 3.47mm. The total length TTL of the optical imaging lens group is 17.19mm.

Table 13 shows a basic structural parameter table of an optical imaging lens group of example five, in which the units of radius of curvature, thickness/distance, and focal length are all millimeters (mm).

TABLE 13

Table 14 shows part of parameters of the optical imaging lens group of example five in the first object distance state and the second object distance state.

Parameters (parameters)	First object distance state	Second object distance state
			OBJ(mm)	Infinity (IN)	100(M)
Semi-FOV(°)	10.7	10.1
			f/EPD	3.30	3.39
f(mm)	18.24	14.39
			T34(mm)	3.16	6.31
BFL(mm)	6.55	3.40

TABLE 14

Table 15 shows the higher order coefficients that can be used for each aspherical mirror in example five, where each aspherical mirror type can be defined by equation (1) given in example one above.

TABLE 15

Fig. 42 shows an on-axis chromatic aberration curve of the optical imaging lens group of example five in the first object distance state, which indicates a convergent focus deviation of light rays of different wavelengths after passing through the optical imaging lens group. Fig. 43 shows an astigmatism curve of the optical imaging lens group of example five in the first object distance state, which indicates a meridional image plane curvature and a sagittal image plane curvature. Fig. 44 shows a distortion curve of the optical imaging lens group of example five in the first object distance state, which represents distortion magnitude values corresponding to different angles of view. Fig. 45 shows a magnification chromatic aberration curve of the optical imaging lens group of example five in the first object distance state, which represents the deviation of different image heights on the imaging plane after light passes through the optical imaging lens group.

Fig. 47 shows an on-axis chromatic aberration curve of the optical imaging lens group in the second object distance state of example five, which indicates a convergent focus deviation of light rays of different wavelengths after passing through the optical imaging lens group. Fig. 48 shows an astigmatism curve of the optical imaging lens group in the second object distance state of example five, which indicates meridional image plane curvature and sagittal image plane curvature. Fig. 49 shows a distortion curve of the optical imaging lens group of example five in the second object distance state, which represents distortion magnitude values corresponding to different angles of view. Fig. 50 shows a magnification chromatic aberration curve of the optical imaging lens group in the second object distance state of example five, which represents the deviation of different image heights on the imaging plane after light passes through the optical imaging lens group.

As can be seen from fig. 43 to 45 and fig. 47 to 50, the optical imaging lens group given in example five can achieve good imaging quality.

In summary, examples one to five satisfy the relationships shown in table 16, respectively.

Condition/example	1	2	3	4	5
						f1/R1	1.77	1.90	1.76	1.77	1.65
f2/R4	-3.65	-3.88	-3.79	-3.67	-3.69
						f4/R6	3.08	2.78	4.88	2.60	2.19
f/R7	-6.11	-3.41	-6.46	-1.80	-8.67
						T23/CT2	1.55	1.48	2.07	1.56	1.67
CT1/CT4	2.98	1.36	2.38	1.12	5.57
						CT3/CT2	1.74	2.05	1.81	1.82	1.02
TTL/BFL(IN)	3.46	1.82	1.90	1.90	2.62
						SD(IN)/T34(IN)	5.12	3.24	2.48	4.07	2.40
TTL/f(IN)	0.99	1.01	1.00	0.99	0.94
						TTL/BFL(M)	2.06	2.23	3.03	2.84	5.06
SD(M)/T34(M)	1.13	1.53	1.52	1.91	1.70

Table 16

Table 17 gives effective focal lengths f1 to f5 of the respective lenses of the optical imaging lens groups of examples one to five.

Example parameters	1	2	3	4	5
						f1(mm)	9.56	11.37	9.65	9.62	8.69
f2(mm)	-9.40	-9.46	-10.34	-9.41	-10.14
						f3(mm)	12.66	9.89	14.53	12.08	16.45
f4(mm)	-20.61	-21.21	-34.53	-16.48	-15.11
						f5(mm)	164.88	2721.29	-100.00	94.83	106.41
TTL(mm)	18.03	18.42	18.12	18.07	17.19
						ImgH(mm)	3.47	3.47	3.47	3.47	3.47

TABLE 17

The application also provides an imaging device, wherein the electronic photosensitive element can 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 apparatus is equipped with the above-described optical imaging lens group.

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 exemplary embodiments according to 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 the 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 application described herein may be implemented in sequences other than those illustrated or otherwise 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 pick-up lens group is characterized in that the optical pick-up lens group comprises five lenses, the lenses are all plastic aspheric lenses, an air space is arranged between the lenses, the lenses are divided into a fixed group and a focusing group,

The fixed group comprises a first lens with positive focal power, a second lens with negative focal power and a third lens with positive focal power, wherein the image side surface of the third lens is a convex surface, the object side surface and the image side surface of the first lens are both convex surfaces, the object side surface of the second lens is a convex surface, and the image side surface of the second lens is a concave surface;

the focusing group comprises a fourth lens with negative focal power and a fifth lens with focal power, the object side surface of the fourth lens is a concave surface, and the object side surface of the fifth lens is a convex surface;

an effective focal length f4 of the fourth lens and a curvature radius R6 of an image side surface of the third lens satisfy: f4/R6 is more than 2.0 and less than 5.0;

The effective focal length f of the optical imaging lens group and the curvature radius R7 of the object side surface of the fourth lens satisfy the following conditions: -f/R7 is less than or equal to-9.0 and less than or equal to-3.41;

An on-axis distance TTL from the object side surface of the first lens element to the imaging surface of the optical imaging lens assembly, and a distance BFL (M) from the image side surface of the fifth lens element to the imaging surface on the optical axis of the optical imaging lens assembly when the object distance of the optical imaging lens assembly is 100mm, are satisfied: 2.0 < TTL/BFL (M) < 5.5.

2. The optical imaging lens assembly according to claim 1, wherein an effective focal length f1 of the first lens and a radius of curvature R1 of an object side surface of the first lens satisfy: 1.5 < f1/R1 < 2.0.

3. The optical imaging lens group according to claim 1, wherein an effective focal length f2 of the second lens and a curvature radius R4 of an image side surface of the second lens satisfy: -4.0 < f2/R4 < -1.5.

4. The optical imaging lens group according to claim 1, wherein a maximum field angle FOV of the optical imaging lens group satisfies: FOV < 25 deg..

5. The optical imaging lens group according to claim 1, wherein an effective focal length f of the optical imaging lens group and an entrance pupil diameter EPD of the optical imaging lens group satisfy: 2.0 < f/EPD < 3.5.

6. The optical imaging lens group according to claim 1, wherein an air interval T23 of the second lens and the third lens on an optical axis of the optical imaging lens group and a center thickness CT2 of the second lens on the optical axis satisfy: T23/CT2 is more than 1.0 and less than 2.5.

7. The optical imaging lens group according to claim 1, wherein a center thickness CT1 of the first lens on an optical axis of the optical imaging lens group and a center thickness CT4 of the fourth lens on the optical axis satisfy: CT1/CT4 is more than 1.0 and less than 6.0.

8. The optical imaging lens group according to claim 1, wherein a center thickness CT2 of the second lens on an optical axis of the optical imaging lens group and a center thickness CT3 of the third lens on the optical axis satisfy: CT3/CT2 is more than 1.0 and less than 3.0.

9. The optical imaging lens assembly of claim 1, wherein an on-axis distance TTL from an object side surface of the first lens element to an imaging surface of the optical imaging lens assembly, and a distance BFL (IN) from an image side surface of the fifth lens element to the imaging surface on an optical axis of the optical imaging lens assembly when the optical imaging lens assembly is at an infinitely distant object distance satisfy: 1.5 < TTL/BFL (IN) < 3.5.

10. The optical imaging lens group according to claim 1, wherein a distance SD (IN) from a stop of the optical imaging lens group to an image side surface of the fifth lens at an infinite object distance, and an air interval T34 (IN) between the third lens and the fourth lens on an optical axis of the optical imaging lens group at an infinite object distance satisfy: 2.0 < SD (IN)/T34 (IN) < 6.0.

11. The optical imaging lens group according to claim 1, wherein a distance SD (M) from a stop of the optical imaging lens group to an image side surface of the fifth lens at a 100mm object distance, and an air interval T34 (M) between the third lens and the fourth lens on an optical axis of the optical imaging lens group at a 100mm object distance satisfy: 1.0 < SD (M)/T34 (M) < 2.5.

12. An optical pick-up lens group is characterized in that the optical pick-up lens group comprises five lenses, the lenses are all plastic aspheric lenses, an air space is arranged between the lenses, the lenses are divided into a fixed group and a focusing group,

An on-axis distance TTL from an object side surface of the first lens to an imaging surface of the optical imaging lens assembly, and an effective focal length f (IN) of the optical imaging lens assembly when the optical imaging lens assembly is at an infinite object distance are as follows: 0.7 <

TTL/f(IN)＜1.1；

13. The optical imaging lens assembly according to claim 12, wherein an effective focal length f1 of the first lens and a radius of curvature R1 of an object side surface of the first lens satisfy: 1.5 < f1/R1 < 2.0.

14. The optical imaging lens group according to claim 12, wherein an effective focal length f2 of the second lens and a radius of curvature R4 of an image side surface of the second lens satisfy: -4.0 < f2/R4 < -1.5.

15. The optical imaging lens group according to claim 12, wherein a maximum field angle FOV of the optical imaging lens group satisfies: FOV < 25 deg..

16. The optical imaging lens group according to claim 12, wherein an effective focal length f of the optical imaging lens group and an entrance pupil diameter EPD of the optical imaging lens group satisfy: 2.0 < f/EPD < 3.5.

17. The optical imaging lens group according to claim 12, wherein an air interval T23 of the second lens and the third lens on an optical axis of the optical imaging lens group and a center thickness CT2 of the second lens on the optical axis satisfy: T23/CT2 is more than 1.0 and less than 2.5.

18. The optical imaging lens group according to claim 12, wherein a center thickness CT1 of the first lens on an optical axis of the optical imaging lens group and a center thickness CT4 of the fourth lens on the optical axis satisfy: CT1/CT4 is more than 1.0 and less than 6.0.

19. The optical imaging lens group according to claim 12, wherein a center thickness CT2 of the second lens on an optical axis of the optical imaging lens group and a center thickness CT3 of the third lens on the optical axis satisfy: CT3/CT2 is more than 1.0 and less than 3.0.

20. The optical imaging lens assembly of claim 12, wherein an on-axis distance TTL from an object side surface of the first lens element to an imaging surface of the optical imaging lens assembly, and a distance BFL (IN) from an image side surface of the fifth lens element to the imaging surface on an optical axis of the optical imaging lens assembly at an infinitely distant object distance are as follows: 1.5 < TTL/BFL (IN) < 3.5.

21. The optical imaging lens group according to claim 12, wherein a distance SD (IN) from a stop to an image side surface of the fifth lens at an infinitely distant object distance, and an air interval T34 (IN) between the third lens and the fourth lens on an optical axis of the optical imaging lens group at an infinitely distant object distance satisfy: 2.0 < SD (IN)/T34 (IN) < 6.0.

22. The optical imaging lens group according to claim 12, wherein a distance SD (M) from a stop of the optical imaging lens group to an image side surface of the fifth lens at a 100mm object distance, and an air interval T34 (M) between the third lens and the fourth lens on an optical axis of the optical imaging lens group at a 100mm object distance satisfy: 1.0 < SD (M)/T34 (M) < 2.5.