CN113985583B

CN113985583B - Optical lens group

Info

Publication number: CN113985583B
Application number: CN202111370433.2A
Authority: CN
Inventors: 赵跇坤; 贺凌波; 戴付建; 赵烈烽
Original assignee: Zhejiang Sunny Optics Co Ltd
Current assignee: Zhejiang Sunny Optics Co Ltd
Priority date: 2021-11-18
Filing date: 2021-11-18
Publication date: 2023-10-31
Anticipated expiration: 2041-11-18
Also published as: CN113985583A

Abstract

The invention provides an optical lens group. The method from the object side of the optical lens group to the image side of the optical lens group comprises the following steps: a first lens having a negative refractive power; a diaphragm; a second lens having positive refractive power; a third lens having refractive power, the radius of curvature of the object-side surface of the third lens being a positive value; a fourth lens having refractive power; a fifth lens having refractive power; the optical lens group satisfies: r3/f2 is more than 1.0 and less than 2.0; wherein R3 is a radius of curvature of the object side surface of the second lens, and f2 is an effective focal length of the second lens. The invention solves the problem of poor imaging quality when the lens shoots a large range in the prior art.

Description

Optical lens group

Technical Field

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

Background

Along with the rapid development of smart phones, the smart phones are widely applied to the field of photographing in daily life besides being important communication equipment in daily life, so that the requirements of people on the photographing function of the smart phones are higher and higher, and particularly when photographing objects with wider fields such as mountains and rivers. 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, the existing lens has a problem of poor effect on a large-scale shooting.

That is, the lens in the prior art has a problem of poor imaging quality when photographing a large range.

Disclosure of Invention

The invention mainly aims to provide an optical lens group so as to solve the problem that imaging quality is poor when a lens in the prior art shoots a large range.

In order to achieve the above object, according to one aspect of the present invention, there is provided an optical lens group including, from an object side of the optical lens group to an image side of the optical lens group: a first lens having a negative refractive power; a diaphragm; a second lens having positive refractive power; a third lens having refractive power, the radius of curvature of the object-side surface of the third lens being a positive value; a fourth lens having refractive power; a fifth lens having refractive power; the optical lens group satisfies: r3/f2 is more than 1.0 and less than 2.0; wherein R3 is a radius of curvature of the object side surface of the second lens, and f2 is an effective focal length of the second lens.

Further, the optical lens group satisfies: CT4 is more than 0.2 and less than or equal to 0.8, wherein CT4 is the center thickness of the fourth lens on the optical axis of the optical lens group.

Further, the optical lens group satisfies: CT5/CT4 is more than 0 and less than 1.2, wherein CT5 is the center thickness of the fifth lens on the optical axis of the optical lens group, and CT4 is the center thickness of the fourth lens on the optical axis.

Further, the optical lens group satisfies: 1.5 < (T12+CT1)/(T12-CT 1) < 3.0, wherein CT1 is the center thickness of the first lens on the optical axis of the optical lens group, and T12 is the air space between the first lens and the second lens on the optical axis.

Further, the optical lens group satisfies: 2.5 < SD/CT4 < 4.6, wherein SD is the distance from the aperture stop to the image side of the last lens, and CT4 is the center thickness of the fourth lens on the optical axis of the optical lens group.

Further, the optical lens group satisfies: and (2.0 < SL/(T12+T23) is less than or equal to 4.0, wherein SL is the on-axis distance from the diaphragm to the imaging surface of the optical lens group, T12 is the air interval of the first lens and the second lens on the optical axis of the optical lens group, and T23 is the air interval of the second lens and the third lens on the optical axis.

Further, the optical lens group satisfies: 1.5 < TD/ΣET < 2.0, where TD is the on-axis distance from the object side of the first lens to the image side of the last lens, ΣET is the sum of the edge thicknesses of all the lenses of the optical lens assembly.

Further, the optical lens group satisfies: f12/f23 is more than 0 and less than 1.2, wherein f12 is the combined focal length of the first lens and the second lens, and f23 is the combined focal length of the second lens and the third lens.

Further, the optical lens group satisfies: 2.0 < (SAG11+SAG12)/ET 1 < 4.0, wherein SAG11 is an on-axis distance between an intersection point of an object side surface of the first lens and an optical axis of the optical lens group to an effective radius vertex of the object side surface of the first lens, SAG12 is an on-axis distance between an intersection point of an image side surface of the first lens and the optical axis to an effective radius vertex of the image side surface of the first lens, and ET1 is an edge thickness of the first lens.

Further, the optical lens group satisfies: -2.5 < f1/f234 < -1.5, wherein f1 is the effective focal length of the first lens and f234 is the combined focal length of the second, third and fourth lenses.

Further, the optical lens group satisfies: -3.5 < CT5/SAG51 < -0.5, wherein CT5 is the central thickness of the fifth lens on the optical axis of the optical lens group, SAG51 is the axial distance between the intersection of the object side of the fifth lens and the optical axis and the vertex of the effective radius of the object side of the fifth lens.

Further, the optical lens group satisfies: n5 > 1.65, wherein N5 is the refractive index of the fifth lens.

Further, the optical lens group satisfies: the Semi-FOV is more than 45 degrees, wherein the Semi-FOV is half of the maximum field angle of the optical lens group.

According to another aspect of the present invention, there is provided an optical lens group, including, from an object side of the optical lens group to an image side of the optical lens group: a first lens having a negative refractive power; a diaphragm; a second lens having positive refractive power; a third lens having refractive power, the radius of curvature of the object-side surface of the third lens being a positive value; a fourth lens having refractive power; a fifth lens having refractive power; the optical lens group satisfies: CT5/CT4 is more than 0 and less than 1.2, wherein CT5 is the center thickness of the fifth lens on the optical axis of the optical lens group, and CT4 is the center thickness of the fourth lens on the optical axis.

By applying the technical scheme of the invention, the object side of the optical lens group to the image side of the optical lens group comprises a first lens with negative refractive power, a diaphragm, a second lens with positive refractive power, a third lens with refractive power, a fourth lens with refractive power and a fifth lens with refractive power; the radius of curvature of the object side surface of the third lens is a positive value; the optical lens group satisfies: r3/f2 is more than 1.0 and less than 2.0; wherein R3 is a radius of curvature of the object side surface of the second lens, and f2 is an effective focal length of the second lens.

The first lens is reasonably distributed to be negative refractive power, so that the optical lens group has the advantage of large field angle, and the second lens is reasonably distributed to be positive refractive power, thereby being beneficial to increasing the field angle and correcting the off-axis aberration of the optical lens group. The radius of curvature of the object side surface of the third lens is reasonably distributed to be a positive value, so that light rays can be better converged, and the image quality of the optical lens group is improved. The ratio of the curvature radius of the object side surface of the second lens to the effective focal length of the second lens is reasonably controlled within a reasonable range, so that the field curvature and distortion of the optical lens group can be improved, and the processing difficulty of the second lens is controlled, thereby being beneficial to the forming of the second lens.

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 the structure of an optical lens group according to an example I of the present application;

FIGS. 2 and 3 show on-axis chromatic aberration curves and astigmatism curves, respectively, of the optical lens group of FIG. 1;

FIG. 4 is a schematic view showing the structure of an optical lens group according to example II of the present application;

FIGS. 5 and 6 show on-axis chromatic aberration curves and astigmatism curves, respectively, of the optical lens group of FIG. 4;

FIG. 7 is a schematic view showing the structure of an optical lens group of example III of the present application;

fig. 8 and 9 show on-axis chromatic aberration curves and astigmatism curves, respectively, of the optical lens group of fig. 7;

fig. 10 is a schematic view showing the structure of an optical lens group of example four of the present application;

FIGS. 11 and 12 show on-axis chromatic aberration curves and astigmatism curves, respectively, of the optical lens group of FIG. 10;

fig. 13 is a schematic view showing the structure of an optical lens group of example five of the present application;

fig. 14 and 15 show on-axis chromatic aberration curves and astigmatism curves, respectively, of the optical lens group in fig. 13;

Fig. 16 is a schematic view showing the structure of an optical lens group of example six of the present application;

fig. 17 and 18 show on-axis chromatic aberration curves and astigmatism curves, respectively, of the optical lens group in fig. 16.

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 application, 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 application.

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 near the object side becomes the object side of the lens, and the surface of each lens near the image side is called the image side of the lens. 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; the image side face is determined to be concave when the R value is positive, and convex when the R value is negative.

The invention provides an optical lens group for solving the problem that imaging quality is poor when a lens in the prior art shoots a large range.

Example 1

As shown in fig. 1 to 18, the optical lens group includes, from an object side to an image side thereof, a first lens having negative refractive power, a stop, a second lens having positive refractive power, a third lens having refractive power, a fourth lens having refractive power, and a fifth lens having refractive power; the radius of curvature of the object side surface of the third lens is a positive value; the optical lens group satisfies: r3/f2 is more than 1.0 and less than 2.0; wherein R3 is a radius of curvature of the object side surface of the second lens, and f2 is an effective focal length of the second lens.

The first lens is reasonably distributed to be negative refractive power, so that the optical lens group has the advantage of large field angle, and the second lens is reasonably distributed to be positive refractive power, thereby being beneficial to increasing the field angle and correcting the off-axis aberration of the optical lens group. The radius of curvature of the object side surface of the third lens is reasonably distributed to be a positive value, so that light rays can be better converged, and the image quality of the optical lens group is improved. The ratio of the curvature radius of the object side surface of the second lens to the effective focal length of the second lens is reasonably controlled within a reasonable range, so that the field curvature and distortion of the optical lens group can be improved, and the processing difficulty of the second lens is controlled, thereby being beneficial to the forming of the second lens. Preferably, 1.1 < R3/f2 < 1.9.

In the present embodiment, the optical lens group satisfies: CT4 is more than 0.2 and less than or equal to 0.8, wherein CT4 is the center thickness of the fourth lens on the optical axis of the optical lens group. The center thickness of the fourth lens on the optical axis is controlled in a reasonable range, so that the fourth lens is easy to injection mold, and the processing difficulty of the fourth lens is reduced. Preferably, CT4 is more than 0.3 and less than or equal to 0.8.

In the present embodiment, the optical lens group satisfies: CT5/CT4 is more than 0 and less than 1.2, wherein CT5 is the center thickness of the fifth lens on the optical axis of the optical lens group, and CT4 is the center thickness of the fourth lens on the optical axis. The center thickness of the fourth lens on the optical axis is controlled in a reasonable range, so that the fourth lens is easy to injection mold, and the processing difficulty of the fourth lens is reduced. Preferably, 0.1 < CT5/CT4 < 1.0.

In the present embodiment, the optical lens group satisfies: 1.5 < (T12+CT1)/(T12-CT 1) < 3.0, wherein CT1 is the center thickness of the first lens on the optical axis of the optical lens group, and T12 is the air space between the first lens and the second lens on the optical axis. The ratio of the sum of the air interval of the first lens and the second lens on the optical axis and the center thickness of the first lens on the optical axis to the difference between the two thicknesses is controlled within a reasonable range, so that the assembly stability of the optical lens group and the consistency of mass production are improved, and the production yield of the optical lens group is improved. Preferably, 1.52 < (T12+CT1)/(T12-CT 1) < 2.8.

In the present embodiment, the optical lens group satisfies: 2.5 < SD/CT4 < 4.6, wherein SD is the distance from the aperture stop to the image side of the last lens, and CT4 is the center thickness of the fourth lens on the optical axis of the optical lens group. The processing and assembling difficulty is reduced by controlling the ratio of the distance from the diaphragm to the image side surface of the last lens to the thickness of the center of the fourth lens on the optical axis within a reasonable range. Preferably, 2.55 < SD/CT4 < 4.6.

In the present embodiment, the optical lens group satisfies: and (2.0 < SL/(T12+T23) is less than or equal to 4.0, wherein SL is the on-axis distance from the diaphragm to the imaging surface of the optical lens group, T12 is the air interval of the first lens and the second lens on the optical axis of the optical lens group, and T23 is the air interval of the second lens and the third lens on the optical axis. By controlling SL/(T12+T23) within a reasonable range, the assembly stability of the optical lens group and the consistency of mass production are improved, and the production yield of the optical lens group is improved. Preferably, 2.1 < SL/(T12+T23). Ltoreq.4.0.

In the present embodiment, the optical lens group satisfies: 1.5 < TD/ΣET < 2.0, where TD is the on-axis distance from the object side of the first lens to the image side of the last lens, ΣET is the sum of the edge thicknesses of all the lenses of the optical lens assembly. By controlling the TD/Σet within a reasonable range, it is advantageous to reduce the sensitivity of the optical lens group and to realize the high resolution characteristic of the optical lens group. Preferably, 1.6 < TD/ΣET < 2.0.

In the present embodiment, the optical lens group satisfies: f12/f23 is more than 0 and less than 1.2, wherein f12 is the combined focal length of the first lens and the second lens, and f23 is the combined focal length of the second lens and the third lens. The ratio of the combined focal length of the first lens to the combined focal length of the second lens to the combined focal length of the third lens are controlled within a reasonable range, so that better balance of aberration of the optical lens group is facilitated, and meanwhile, the resolution of the optical lens group is facilitated to be improved. Preferably, 0.2 < f12/f23 < 1.12.

In the present embodiment, the optical lens group satisfies: 2.0 < (SAG11+SAG12)/ET 1 < 4.0, wherein SAG11 is an on-axis distance between an intersection point of an object side surface of the first lens and an optical axis of the optical lens group to an effective radius vertex of the object side surface of the first lens, SAG12 is an on-axis distance between an intersection point of an image side surface of the first lens and the optical axis to an effective radius vertex of the image side surface of the first lens, and ET1 is an edge thickness of the first lens. By controlling (SAG11+SAG12)/ET 1 within a reasonable range, the first lens can be prevented from being excessively bent, the processing difficulty is reduced, and meanwhile, the assembly of the optical lens group has higher stability. Preferably, 2.05 < (SAG11+SAG12)/ET 1 < 3.97.

In the present embodiment, the optical lens group satisfies: -2.5 < f1/f234 < -1.5, wherein f1 is the effective focal length of the first lens and f234 is the combined focal length of the second, third and fourth lenses. The ratio of the effective focal length of the first lens to the combined focal length of the second lens, the third lens and the fourth lens is reasonably controlled within a reasonable range, so that better balance of aberration of the optical lens group is facilitated, and meanwhile, the resolution of the optical lens group is improved. Preferably, -2.4 < f1/f234 < -1.6.

In the present embodiment, the optical lens group satisfies: -3.5 < CT5/SAG51 < -0.5, wherein CT5 is the central thickness of the fifth lens on the optical axis of the optical lens group, SAG51 is the axial distance between the intersection of the object side of the fifth lens and the optical axis and the vertex of the effective radius of the object side of the fifth lens. By controlling the CT5/SAG51 within a reasonable range, the fifth lens can be prevented from being excessively bent, the processing difficulty is reduced, and meanwhile, the optical lens group has better capability of balancing chromatic aberration and distortion. Preferably, -3.4 < CT5/SAG51 < -0.6.

In the present embodiment, the optical lens group satisfies: n5 > 1.65, wherein N5 is the refractive index of the fifth lens. The refractive index of the fifth lens is reasonably controlled within a certain range, so that the optical lens group obtains higher image quality.

In the present embodiment, the optical lens group satisfies: the Semi-FOV is more than 45 degrees, wherein the Semi-FOV is half of the maximum field angle of the optical lens group. The half field angle of the optical lens group is larger than 45 degrees, which is beneficial to enlarging the obtained object information and enlarging the shooting range of the optical lens group.

Example two

As shown in fig. 1 to 18, from the object side of the optical lens group to the image side of the optical lens group, it includes: a first lens having a negative refractive power; a diaphragm; a second lens having positive refractive power; a third lens having refractive power, the radius of curvature of the object-side surface of the third lens being a positive value; a fourth lens having refractive power; a fifth lens having refractive power; the optical lens group satisfies: CT5/CT4 is more than 0 and less than 1.2, wherein CT5 is the center thickness of the fifth lens on the optical axis of the optical lens group, and CT4 is the center thickness of the fourth lens on the optical axis.

The first lens is reasonably distributed to be negative refractive power, so that the optical lens group has the advantage of large field angle, and the second lens is reasonably distributed to be positive refractive power, thereby being beneficial to increasing the field angle and correcting the off-axis aberration of the optical lens group. The radius of curvature of the object side surface of the third lens is reasonably distributed to be a positive value, so that light rays can be better converged, and the image quality of the optical lens group is improved. The center thickness of the fourth lens on the optical axis is controlled in a reasonable range, so that the fourth lens is easy to injection mold, and the processing difficulty of the fourth lens is reduced.

Preferably, 0.1 < CT5/CT4 < 1.0.

The optical lens assembly of 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 lens group can be effectively increased, the sensitivity of the optical lens group can be reduced, and the processability of the optical lens group can be improved, so that the optical 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, those skilled in the art will appreciate that the number of lenses making up an optical lens group can be varied to achieve the various results and advantages described in this specification without departing from the scope of the application as claimed. For example, although the description has been made by taking five lenses as an example in the embodiment, the optical lens group is not limited to include five lenses. The optical lens group may also include other numbers of lenses, if desired.

Examples of specific surface types and parameters applicable to the optical lens groups of the above embodiments are further described below with reference to the drawings.

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 3, an optical lens group according to an example one of the present application is described. Fig. 1 shows a schematic diagram of an optical lens group structure of example one.

As shown in fig. 1, the optical lens assembly sequentially includes, from an object side to an image 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 has a negative refractive power, wherein a radius of curvature of the object-side surface S1 of the first lens element is negative, and a radius of curvature of the image-side surface S2 of the first lens element is positive. The second lens element E2 has a positive refractive power, wherein a radius of curvature of the object-side surface S3 of the second lens element is positive, and a radius of curvature of the image-side surface S4 of the second lens element is negative. The third lens element E3 has a negative refractive power, wherein the radius of curvature of the object-side surface S5 of the third lens element is positive, and the radius of curvature of the image-side surface S6 of the third lens element is positive. The fourth lens element E4 has a positive refractive power, wherein a radius of curvature of the object-side surface S7 of the fourth lens element is negative, and a radius of curvature of the image-side surface S8 of the fourth lens element is negative. The fifth lens element E5 has a negative refractive power, wherein the radius of curvature of the object-side surface S9 of the fifth lens element is positive, and the radius of curvature of the image-side surface S10 of the fifth lens element is positive. 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 total effective focal length f of the optical lens group is 1.13mm, the total length TTL of the optical lens group is 3.78mm and the image height ImgH is 1.91mm.

Table 1 shows a basic structural parameter table of an optical lens group 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 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 following Table 2 shows the higher order coefficients A4, A6, A8, A10, A12, A14, A16, A18, A20, A22, A24, A26 that can be used for each of the aspherical mirrors S1-S10 in example one.

Face number

A4

A6

A8

A10

A12

A14

S1

7.3794E-01

-5.4202E-02

2.4435E-02

-5.1657E-03

2.6999E-03

-1.5197E-04

S2

2.5253E-01

2.6221E-03

1.3094E-03

-4.1850E-03

-2.7746E-03

-1.4742E-03

S3

-5.3975E-03

-9.4614E-04

-1.0479E-04

-1.5435E-05

1.6650E-06

-5.2462E-06

S4

-8.7220E-02

-4.1166E-03

-2.7306E-03

-7.0486E-05

8.1456E-06

9.2551E-05

S5

-1.8954E-01

1.5355E-02

-6.9810E-04

1.3391E-03

5.2821E-04

2.0778E-04

S6

-9.2590E-02

1.5104E-02

-1.9593E-03

1.0571E-03

1.1850E-04

1.7836E-05

S7

8.9796E-02

-1.4952E-02

6.6491E-03

8.4525E-04

-2.7493E-05

-2.9927E-04

S8

2.0668E-01

-2.2339E-03

6.6282E-03

1.5826E-03

3.0605E-03

3.3503E-04

S9

-8.3593E-01

6.6058E-02

-2.4244E-02

1.6436E-02

2.8851E-03

1.5183E-04

S10

-8.5560E-01

9.7385E-02

-5.5970E-02

2.2600E-02

-8.2138E-03

3.9269E-03

Face number

A16

A18

A20

A22

A24

A26

S1

6.2405E-04

9.4487E-05

1.0419E-04

0.0000E+00

S2

-5.8465E-04

-1.5209E-04

-2.4023E-05

0.0000E+00

S3

6.0213E-07

-3.1008E-06

1.5439E-07

0.0000E+00

S4

3.9365E-05

3.8761E-05

2.0973E-05

5.4522E-06

1.5727E-06

-6.7722E-08

S5

-6.6615E-05

-3.4623E-05

-1.3032E-05

0.0000E+00

S6

-5.5371E-05

-5.9114E-05

1.4969E-05

0.0000E+00

S7

-9.6998E-06

-1.3425E-04

8.2625E-05

0.0000E+00

S8

2.1930E-04

3.3537E-05

-2.1417E-05

-3.3881E-05

-2.1803E-05

2.8165E-06

S9

4.2048E-04

-6.5392E-04

-1.7578E-05

0.0000E+00

S10

-7.8215E-04

3.8110E-04

3.4936E-04

0.0000E+00

TABLE 2

Fig. 2 shows an on-axis chromatic aberration curve of an optical lens group of example one, which indicates the deviation of the converging focus of light rays of different wavelengths after passing through the optical lens group. Fig. 3 shows an astigmatism curve of the optical lens group of example one, which represents meridional image surface curvature and sagittal image surface curvature.

As can be seen from fig. 2 and 3, the optical lens assembly according to example one can achieve good imaging quality.

Example two

As shown in fig. 4 to 6, an optical lens group 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. 4 shows a schematic diagram of an optical lens group structure of example two.

As shown in fig. 4, the optical lens assembly sequentially includes, from an object side to an image 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 has a negative refractive power, wherein a radius of curvature of the object-side surface S1 of the first lens element is negative, and a radius of curvature of the image-side surface S2 of the first lens element is positive. The second lens element E2 has a positive refractive power, wherein a radius of curvature of the object-side surface S3 of the second lens element is positive, and a radius of curvature of the image-side surface S4 of the second lens element is negative. The third lens element E3 has a negative refractive power, wherein the radius of curvature of the object-side surface S5 of the third lens element is positive, and the radius of curvature of the image-side surface S6 of the third lens element is positive. The fourth lens element E4 has a positive refractive power, wherein the radius of curvature of the object-side surface S7 of the fourth lens element is positive, and the radius of curvature of the image-side surface S8 of the fourth lens element is positive. The fifth lens element E5 has a positive refractive power, wherein the radius of curvature of the object-side surface S9 of the fifth lens element is positive, and the radius of curvature of the image-side surface S10 of the fifth lens element is positive. 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 total effective focal length f of the optical lens group is 0.97mm, the total length TTL of the optical lens group is 4.08mm and the image height ImgH is 1.91mm.

Table 3 shows a basic structural parameter table of the optical lens group 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.

TABLE 4 Table 4

Fig. 5 shows an on-axis chromatic aberration curve of an optical lens group of example two, which indicates the deviation of the converging focus of light rays of different wavelengths after passing through the optical lens group. Fig. 6 shows an astigmatism curve of the optical lens group of example two, which represents meridional image surface curvature and sagittal image surface curvature.

As can be seen from fig. 5 and 6, the optical lens assembly of example two can achieve good imaging quality.

Example three

As shown in fig. 7 to 9, an optical lens group of example three of the present application is described. Fig. 7 shows a schematic diagram of an optical lens group structure of example three.

As shown in fig. 7, the optical lens assembly sequentially includes, from an object side to an image 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 has a negative refractive power, wherein a radius of curvature of the object-side surface S1 of the first lens element is negative, and a radius of curvature of the image-side surface S2 of the first lens element is positive. The second lens element E2 has a positive refractive power, wherein a radius of curvature of the object-side surface S3 of the second lens element is positive, and a radius of curvature of the image-side surface S4 of the second lens element is negative. The third lens element E3 has a negative refractive power, wherein the radius of curvature of the object-side surface S5 of the third lens element is positive, and the radius of curvature of the image-side surface S6 of the third lens element is positive. The fourth lens element E4 has a positive refractive power, wherein a radius of curvature of the object-side surface S7 of the fourth lens element is negative, and a radius of curvature of the image-side surface S8 of the fourth lens element is negative. The fifth lens element E5 has a positive refractive power, wherein the radius of curvature of the object-side surface S9 of the fifth lens element is positive, and the radius of curvature of the image-side surface S10 of the fifth lens element is positive. 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 total effective focal length f of the optical lens group is 1.14mm, the total length TTL of the optical lens group is 3.59mm and the image height ImgH is 1.91mm.

Table 5 shows a basic structural parameter table of the optical lens group 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.

TABLE 6

Fig. 8 shows an on-axis chromatic aberration curve of the optical lens group of example three, which indicates the deviation of the converging focus of light rays of different wavelengths after passing through the optical lens group. Fig. 9 shows an astigmatism curve of the optical lens group of example three, which represents meridional image plane curvature and sagittal image plane curvature.

As can be seen from fig. 8 and 9, the optical lens group given in example three can achieve good imaging quality.

Example four

As shown in fig. 10 to 12, an optical lens group of example four of the present application is described. Fig. 10 shows a schematic diagram of an optical lens group structure of example four.

As shown in fig. 10, the optical lens assembly sequentially includes, from an object side to an image 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 has a negative refractive power, wherein a radius of curvature of the object-side surface S1 of the first lens element is negative, and a radius of curvature of the image-side surface S2 of the first lens element is positive. The second lens element E2 has a positive refractive power, wherein a radius of curvature of the object-side surface S3 of the second lens element is positive, and a radius of curvature of the image-side surface S4 of the second lens element is negative. The third lens element E3 has a negative refractive power, wherein the radius of curvature of the object-side surface S5 of the third lens element is positive, and the radius of curvature of the image-side surface S6 of the third lens element is positive. The fourth lens element E4 has a negative refractive power, wherein a radius of curvature of the object-side surface S7 of the fourth lens element is negative, and a radius of curvature of the image-side surface S8 of the fourth lens element is negative. The fifth lens element E5 has a positive refractive power, wherein the radius of curvature of the object-side surface S9 of the fifth lens element is positive, and the radius of curvature of the image-side surface S10 of the fifth lens element is positive. 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 total effective focal length f of the optical lens group is 1.10mm, the total length TTL of the optical lens group is 3.56mm and the image height ImgH is 1.91mm.

Table 7 shows a basic structural parameter table of the optical lens group 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.

Face number

A4

A6

A8

A10

A12

A14

A16

S1

7.0781E-01

-4.0151E-02

2.3538E-02

-4.2404E-03

1.6170E-03

-5.2258E-04

9.6858E-05

S2

2.8023E-01

2.4136E-02

8.6610E-03

-3.2309E-03

-4.9507E-03

-4.2202E-03

-2.8697E-03

S3

-5.8746E-03

-1.7875E-03

-2.4292E-04

-2.7928E-05

-2.6243E-06

2.2009E-05

1.4603E-05

S4

-9.6235E-02

-3.3923E-03

-3.5236E-03

-1.1258E-03

-3.7079E-04

-2.6092E-04

-7.9749E-05

S5

-1.8581E-01

1.7829E-02

1.5452E-03

-1.1423E-03

2.4585E-05

9.6317E-05

2.9384E-04

S6

-7.7009E-02

2.3029E-02

1.6582E-03

-3.5751E-03

1.3338E-03

3.2871E-04

3.9521E-04

S7

1.0658E-01

-3.2567E-02

5.0889E-03

1.1904E-04

8.1398E-04

1.0638E-04

1.1979E-04

S8

-3.6267E-01

1.2783E-01

-6.4213E-02

3.8434E-02

-5.9039E-03

1.1489E-02

-2.0259E-03

S9

-1.2162E+00

-3.2112E-02

-1.4290E-01

3.3982E-02

-6.4867E-04

1.9387E-02

-1.9511E-03

S10

-7.7972E-01

1.2122E-01

-6.3551E-02

2.2461E-02

-1.2643E-02

5.8603E-03

-3.4650E-03

Face number

A4

A6

A8

A10

A12

A14

A16

S1

1.0673E-06

-6.9925E-06

2.4461E-05

-9.3831E-06

1.1240E-05

-4.3978E-06

1.6797E-06

S2

-1.5590E-03

-7.2886E-04

-2.6253E-04

-5.6919E-05

4.3425E-06

1.5489E-05

6.8434E-06

S3

1.8647E-05

1.0806E-05

1.1177E-05

5.5809E-06

5.2041E-06

1.9533E-06

2.4968E-06

S4

-6.2140E-05

-8.8362E-06

-1.3063E-05

3.2694E-06

-4.5989E-06

1.4463E-07

-3.1782E-06

S5

3.2970E-04

2.6102E-04

1.7923E-04

9.8491E-05

5.1559E-05

1.6483E-05

5.6454E-06

S6

-1.5616E-04

-2.7021E-04

-2.2029E-04

-1.1040E-04

-3.4347E-05

-1.0100E-05

-1.5120E-06

S7

-9.7992E-05

-3.4278E-05

-2.5313E-05

1.6636E-05

2.2156E-06

8.3505E-06

-7.8736E-06

S8

1.9069E-03

-2.2670E-03

-6.0870E-04

-1.1316E-03

-2.5114E-04

-2.2422E-04

8.9103E-06

S9

2.3705E-04

-4.5167E-03

-8.4304E-04

-6.3135E-04

6.7058E-04

2.3593E-04

2.0543E-04

S10

1.7648E-03

-7.9409E-04

7.3339E-04

-3.6194E-04

7.4281E-06

-2.1628E-04

1.4577E-04

TABLE 8

Fig. 11 shows an on-axis chromatic aberration curve of the optical lens group of example four, which indicates a convergent focus deviation of light rays of different wavelengths after passing through the optical lens group. Fig. 12 shows an astigmatism curve of the optical lens group of example four, which represents meridional image surface curvature and sagittal image surface curvature.

As can be seen from fig. 11 and 12, the optical lens group given in example four can achieve good imaging quality.

Example five

As shown in fig. 13 to 15, an optical lens group of example five of the present application is described. Fig. 13 shows a schematic diagram of an optical lens group structure of example five.

As shown in fig. 13, the optical lens assembly sequentially includes, from an object side to an image 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 has a negative refractive power, wherein a radius of curvature of the object-side surface S1 of the first lens element is negative, and a radius of curvature of the image-side surface S2 of the first lens element is positive. The second lens element E2 has a positive refractive power, wherein a radius of curvature of the object-side surface S3 of the second lens element is positive, and a radius of curvature of the image-side surface S4 of the second lens element is negative. The third lens element E3 has a negative refractive power, wherein the radius of curvature of the object-side surface S5 of the third lens element is positive, and the radius of curvature of the image-side surface S6 of the third lens element is positive. The fourth lens element E4 has a positive refractive power, wherein a radius of curvature of the object-side surface S7 of the fourth lens element is negative, and a radius of curvature of the image-side surface S8 of the fourth lens element is negative. The fifth lens element E5 has a positive refractive power, wherein the object-side surface S9 of the fifth lens element has a positive radius of curvature, and the image-side surface S10 of the fifth lens element has a negative radius of curvature. 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 total effective focal length f of the optical lens group is 1.13mm, the total length TTL of the optical lens group is 4.14mm and the image height ImgH is 1.91mm.

Table 9 shows a basic structural parameter table of the optical lens group 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.

Table 10

Fig. 14 shows an on-axis chromatic aberration curve of the optical lens group of example five, which indicates the convergent focus deviation of light rays of different wavelengths after passing through the optical lens group. Fig. 15 shows an astigmatism curve of the optical lens group of example five, which represents meridional image plane curvature and sagittal image plane curvature.

As can be seen from fig. 14 and 15, the optical lens group given in example five can achieve good imaging quality.

Example six

As shown in fig. 16 to 18, an optical lens group of example six of the present application is described. Fig. 16 shows a schematic diagram of an optical lens group structure of example six.

As shown in fig. 16, the optical lens assembly sequentially includes, from an object side to an image 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 has a negative refractive power, wherein a radius of curvature of the object-side surface S1 of the first lens element is negative, and a radius of curvature of the image-side surface S2 of the first lens element is positive. The second lens element E2 has a positive refractive power, wherein a radius of curvature of the object-side surface S3 of the second lens element is positive, and a radius of curvature of the image-side surface S4 of the second lens element is negative. The third lens element E3 has a negative refractive power, wherein the radius of curvature of the object-side surface S5 of the third lens element is positive, and the radius of curvature of the image-side surface S6 of the third lens element is positive. The fourth lens element E4 has a positive refractive power, wherein the radius of curvature of the object-side surface S7 of the fourth lens element is positive, and the radius of curvature of the image-side surface S8 of the fourth lens element is negative. The fifth lens element E5 has a negative refractive power, wherein the object-side surface S9 of the fifth lens element has a negative radius of curvature, and the image-side surface S10 of the fifth lens element has a positive radius of curvature. 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 total effective focal length f of the optical lens group is 1.12mm, the total length TTL of the optical lens group is 4.03mm and the image height ImgH is 1.91mm.

Table 11 shows a basic structural parameter table of the optical lens group 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

8.1365E-01

-5.7487E-02

2.6314E-02

-7.5817E-03

1.8653E-03

-1.0163E-03

2.5717E-04

S2

3.3687E-01

8.6777E-03

7.2221E-03

-1.4585E-03

-1.3282E-03

-7.2729E-04

-4.4467E-04

S3

-5.9264E-03

-1.0783E-03

-1.2445E-04

-1.9695E-05

-7.6542E-06

4.4995E-06

2.2326E-06

S4

-8.3211E-02

-3.7781E-03

-1.4207E-03

-3.8128E-04

-1.5195E-04

-8.4502E-05

-3.1140E-05

S5

-1.9167E-01

8.5782E-03

2.6009E-03

-1.1905E-04

2.0218E-04

3.1226E-04

3.8358E-04

S6

-1.0114E-01

1.4982E-02

3.0554E-03

-1.6830E-03

2.9243E-04

-4.1568E-04

3.2822E-04

S7

8.4585E-02

-9.6210E-03

5.6643E-03

1.9173E-04

2.1248E-04

-3.2630E-04

3.2339E-04

S8

2.5038E-01

-3.0310E-02

3.2930E-03

4.7403E-03

4.8871E-03

5.7030E-04

1.0743E-03

S9

-8.6249E-01

-2.2170E-01

-5.2128E-02

3.2577E-02

2.6957E-02

7.1720E-03

-2.4714E-03

S10

-9.2697E-01

1.2447E-01

-6.8252E-02

2.3906E-02

-9.0355E-03

3.4196E-03

-9.5437E-04

Face number

A4

A6

A8

A10

A12

A14

A16

S1

-9.2185E-05

6.7242E-05

-8.2169E-06

1.6259E-05

2.5371E-07

-9.6525E-06

4.4273E-06

S2

-9.1782E-05

-4.3161E-05

3.2930E-05

3.4739E-06

2.4910E-05

-2.6823E-06

-3.1245E-06

S3

4.0321E-06

1.2061E-06

2.8185E-06

2.3043E-06

2.9179E-06

1.1535E-06

1.0152E-06

S4

-1.9485E-05

-1.7023E-06

-4.8094E-07

4.8049E-06

1.8399E-06

1.7230E-06

-1.9095E-07

S5

3.2171E-04

2.4269E-04

1.6543E-04

8.6441E-05

4.7021E-05

1.6910E-05

6.0705E-06

S6

-6.4915E-05

1.4568E-04

3.3713E-05

3.7646E-05

1.0862E-05

8.4916E-06

-3.4254E-07

S7

-2.7701E-04

1.6599E-04

-7.0292E-05

2.0677E-05

-5.4860E-07

-1.6479E-06

1.9919E-07

S8

4.5725E-04

1.9508E-04

7.2711E-05

5.3210E-05

5.3961E-06

1.4225E-05

-6.8472E-06

S9

-5.7429E-03

-3.4010E-03

-9.4746E-04

7.5283E-05

3.3314E-04

1.0824E-04

4.2030E-05

S10

-1.4872E-04

3.6574E-04

-4.7867E-05

1.8464E-05

-1.4232E-04

-4.9796E-05

4.6937E-05

Table 12

Fig. 17 shows an on-axis chromatic aberration curve of the optical lens group of example six, which indicates a convergent focus deviation of light rays of different wavelengths after passing through the optical lens group. Fig. 18 shows an astigmatism curve of the optical lens group of example six, which represents meridional image surface curvature and sagittal image surface curvature.

As can be seen from fig. 17 and 18, the optical lens group given in example six can achieve good imaging quality.

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

Condition/example	1	2	3	4	5	6
							R3/f2	1.79	1.23	1.59	1.43	1.47	1.44
CT4	0.77	0.65	0.45	0.49	0.57	0.80
							CT5/CT4	0.41	0.32	0.77	0.87	1.05	0.53
(T12+CT1)/(T12-CT1)	2.65	1.67	2.09	2.27	1.56	1.72
							SD/CT4	2.69	3.70	4.42	4.20	4.59	2.93
SL/(T12+T23)	4.00	2.18	3.14	3.17	2.60	2.66
							TD/∑ET	1.72	1.98	1.72	1.80	1.85	1.84
f12/f23	0.90	0.35	1.03	1.06	0.97	0.99
							(SAG11+SAG12)/ET1	2.10	3.50	2.50	2.56	3.45	3.94
f1/f234	-2.06	-1.88	-1.80	-1.74	-1.90	-2.21
							CT5/SAG51	-2.46	-0.79	-3.33	-1.32	-1.26	-1.03

Table 13 table 14 shows the effective focal lengths f of the optical lens groups 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)	1.13	0.97	1.14	1.10	1.13	1.12
f1(mm)	-2.39	-2.45	-2.41	-2.46	-2.50	-2.46
							f2(mm)	1.45	1.50	1.27	1.26	1.32	1.51
f3(mm)	-3.46	-1.53	-13.43	-18.71	-21.30	-6.90
							f4(mm)	1.16	1.23	10.00	-100.00	5.80	1.09
f5(mm)	-2.15	2.72	42.31	8.87	10.00	-1.16
							TTL(mm)	3.78	4.08	3.59	3.56	4.14	4.03
ImgH(mm)	1.91	1.91	1.91	1.91	1.91	1.91
							Semi-FOV(°)	64.8	48.3	59.9	61.2	55.8	56.1

TABLE 14

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 device is equipped with the optical lens group described above.

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

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

Claims

1. An optical lens group, characterized in that the optical lens group is composed of five lenses with refractive power, and comprises from an object side of the optical lens group to an image side of the optical lens group:

a first lens having a negative refractive power;

a diaphragm;

a second lens having positive refractive power;

a third lens having a negative refractive power, a radius of curvature of an object side surface of the third lens being a positive value;

A fourth lens having refractive power;

a fifth lens having refractive power;

the optical lens group satisfies:

0＜CT5/CT4＜1.2；

Semi-FOV＞45°；

1.0＜R3/f2＜2.0；

wherein, CT5 is the center thickness of the fifth lens element on the optical axis of the optical lens assembly, CT4 is the center thickness of the fourth lens element on the optical axis, semi-FOV is half of the maximum field angle of the optical lens assembly, R3 is the radius of curvature of the object side surface of the second lens element, and f2 is the effective focal length of the second lens element.

2. The optical lens group of claim 1, wherein the optical lens group satisfies: 1.5 < (t12+ct1)/(T12-CT 1) < 3.0, wherein CT1 is the center thickness of the first lens on the optical axis of the optical lens group, and T12 is the air gap of the first lens and the second lens on the optical axis.

3. The optical lens group of claim 1, wherein the optical lens group satisfies: 2.5 < SD/CT4 < 4.6, wherein SD is the distance from the aperture stop to the image side of the last lens, and CT4 is the center thickness of the fourth lens on the optical axis of the optical lens group.

4. The optical lens group of claim 1, wherein the optical lens group satisfies: 2.0 < SL/(T12+T23). Ltoreq.4.0, wherein SL is the on-axis distance from the diaphragm to the imaging surface of the optical lens group, T12 is the air space of the first lens and the second lens on the optical axis of the optical lens group, and T23 is the air space of the second lens and the third lens on the optical axis.

5. The optical lens group of claim 1, wherein the optical lens group satisfies: 1.5 < TD/ΣET < 2.0, where TD is the on-axis distance from the object side of the first lens to the image side of the last lens, ΣET is the sum of the edge thicknesses of all the lenses of the optical lens assembly.

6. The optical lens group of claim 1, wherein the optical lens group satisfies: 0 < f12/f23 < 1.2, wherein f12 is the combined focal length of the first lens and the second lens, and f23 is the combined focal length of the second lens and the third lens.

7. The optical lens group of claim 1, wherein the optical lens group satisfies: 2.0 < (SAG11+SAG12)/ET 1 < 4.0, wherein SAG11 is an on-axis distance between an intersection point of an object side surface of the first lens and an optical axis of the optical lens group to an effective radius vertex of the object side surface of the first lens, SAG12 is an on-axis distance between an intersection point of an image side surface of the first lens and the optical axis to an effective radius vertex of the image side surface of the first lens, and ET1 is an edge thickness of the first lens.

8. The optical lens group of claim 1, wherein the optical lens group satisfies: -2.5 < f1/f234 < -1.5, wherein f1 is the effective focal length of the first lens and f234 is the combined focal length of the second, third and fourth lenses.

9. The optical lens group of claim 1, wherein the optical lens group satisfies: -3.5 < CT5/SAG51 < -0.5, wherein CT5 is the central thickness of the fifth lens on the optical axis of the optical lens group, SAG51 is the on-axis distance between the intersection of the object side of the fifth lens and the optical axis and the vertex of the effective radius of the object side of the fifth lens.

10. The optical lens group of claim 1, wherein the optical lens group satisfies: n5 > 1.65, wherein N5 is the refractive index of the fifth lens.