CN113985583A

CN113985583A - Optical lens group

Info

Publication number: CN113985583A
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: 2022-01-28
Anticipated expiration: 2041-11-18
Also published as: CN113985583B

Abstract

The invention provides an optical lens group. The lens system 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 a positive refractive power; a third lens having 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: r3/f2 is more than 1.0 and less than 2.0; wherein R3 is the radius of curvature of the object-side surface of the second lens, and f2 is the 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

With the rapid development of smart phones, besides being an important communication device in daily life, smart phones are widely used in the field of camera shooting in daily life, so that the requirements of people on camera shooting functions of smart phones are higher and higher, especially when shooting objects with wide visual fields such as mountains, rivers and the like. Under such circumstances, wide-angle lenses are gaining favor from more and more mobile phone manufacturers and consumers. Compared with a common mobile phone lens, the wide-angle lens has the advantages that the depth of field is longer, clear imaging can be achieved within a quite large range, the visual angle is larger, and a large viewing range can be obtained within a limited range. In addition, the lens has stronger perspective, and the shot photos more emphasize the contrast between the close shot and the distant shot, thereby generating strong perspective effect in the depth direction. But the current lens has the problem of poor effect on large-scale shooting.

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

Disclosure of Invention

The invention mainly aims to provide an optical lens group to solve the problem that in the prior art, when a lens is used for shooting a large range, the imaging quality is poor.

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

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

Further, the optical lens group satisfies: 0 < CT5/CT4 < 1.2, wherein CT5 is the central thickness of the fifth lens on the optical axis of the optical lens group, and CT4 is the central thickness of the fourth lens on the optical axis.

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

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

Further, the optical lens group satisfies: SL/(T12+ T23) is more than 2.0 and less than or equal to 4.0, wherein SL is the axial 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/∑ ET < 2.0, where TD is the on-axis distance from the object-side surface of the first lens to the image-side surface of the last lens, and Σ ET is the sum of the edge thicknesses of all lenses of the optical lens group.

Further, 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.

Further, the optical lens group satisfies: 2.0 < (SAG11+ SAG12)/ET1 < 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 and 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 and 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, and SAG51 is the on-axis distance between the intersection of the object-side surface and the optical axis of the fifth lens to the effective radius vertex of the object-side surface 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 comprising, 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 a positive refractive power; a third lens having 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, wherein CT5 is the central thickness of the fifth lens on the optical axis of the optical lens group, and CT4 is the central thickness of the fourth lens on the optical axis.

With the technical solution of the present invention applied, from an object side of the optical lens group to an image side of the optical lens group, the optical lens group includes 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 positive; the optical lens group satisfies: r3/f2 is more than 1.0 and less than 2.0; wherein R3 is the radius of curvature of the object-side surface of the second lens, and f2 is the effective focal length of the second lens.

The first lens is reasonably distributed to have negative refractive power, so that the optical lens group has the advantage of a large field angle, and the second lens is reasonably distributed to have positive refractive power, so that the field angle can be increased, and the off-axis aberration of the optical lens group can be corrected. The curvature radius 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, the processing difficulty of the second lens is controlled, and the forming of the second lens is facilitated.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:

FIG. 1 is a schematic diagram showing a configuration of an optical lens assembly according to a first example of the present invention;

fig. 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 diagram showing a configuration of an optical lens group according to a second example of the present invention;

fig. 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 diagram showing a structure of an optical lens group according to a third example of the present invention;

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 diagram showing the structure of an optical lens group of example four of the present invention;

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

FIG. 13 is a schematic diagram showing the structure of an optical lens group according to example five of the present invention;

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 diagram showing the structure of an optical lens group according to example six of the present invention;

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

Wherein the figures include the following reference numerals:

STO, stop; e1, first lens; s1, the object side surface of the first lens; s2, an image side surface of the first lens; e2, second lens; s3, the object side surface of the second lens; s4, an image side surface of the second lens; e3, third lens; s5, the object side surface of the third lens; s6, an image side surface of the third lens; e4, fourth lens; s7, the object side surface of the fourth lens; s8, an image side surface of the fourth lens element; e5, fifth lens; s9, the object side surface of the fifth lens; s10, an image side surface of the fifth lens element; e6, a filter plate; s11, the object side surface of the filter plate; s12, the image side surface of the filter plate; and S13, imaging surface.

Detailed Description

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

It is noted that, unless otherwise indicated, 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.

In the present invention, unless specified to the contrary, use of the terms of orientation such as "upper, lower, top, bottom" or the like, generally refer to the orientation as shown in the drawings, or to the component itself in a vertical, perpendicular, or gravitational orientation; likewise, for ease of understanding and description, "inner and outer" refer to the inner and outer relative to the profile of the components themselves, but the above directional words are not intended to limit the invention.

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

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

Herein, the paraxial region refers to a region near the optical axis. If the lens surface is convex and the position of the convex is not defined, it means that the lens surface is convex at least in the paraxial region; if the lens surface is concave and the position of the concave is not defined, it means that the lens surface is concave at least in the paraxial region. The surface of each lens close to the object side becomes the object side surface of the lens, and the surface of each lens close to the image side is called the image side surface of the lens. The determination of the surface shape in the paraxial region can be performed by determining whether or not the surface shape is concave or convex, based on the R value (R denotes the radius of curvature of the paraxial region, and usually denotes the R value in a lens database (lens data) in optical software) in accordance with the determination method of a person ordinarily skilled in the art. 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 surface is determined to be concave when the R value is positive, and to be convex when the R value is negative.

The invention provides an optical lens group, aiming at solving the problem of poor imaging quality when a lens in the prior art is used for shooting a large range.

Example one

As shown in fig. 1 to 18, from an object side of the optical lens group to an image side of the optical lens group, 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 positive; the optical lens group satisfies: r3/f2 is more than 1.0 and less than 2.0; wherein R3 is the radius of curvature of the object-side surface of the second lens, and f2 is the effective focal length of the second lens.

The first lens is reasonably distributed to have negative refractive power, so that the optical lens group has the advantage of a large field angle, and the second lens is reasonably distributed to have positive refractive power, so that the field angle can be increased, and the off-axis aberration of the optical lens group can be corrected. The curvature radius 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, the processing difficulty of the second lens is controlled, and the forming of the second lens is facilitated. Preferably, 1.1 < R3/f2 < 1.9.

In the present embodiment, the optical lens group satisfies: and CT4 is more than 0.2 and less than or equal to 0.8, wherein CT4 is the central thickness of the fourth lens on the optical axis of the optical lens group. Through with the central thickness control of fourth lens on the optical axis at reasonable within range for the easy injection moulding of fourth lens reduces the processing degree of difficulty of fourth lens. Preferably, 0.3 < CT4 ≦ 0.8.

In the present embodiment, the optical lens group satisfies: 0 < CT5/CT4 < 1.2, wherein CT5 is the central thickness of the fifth lens on the optical axis of the optical lens group, and CT4 is the central thickness of the fourth lens on the optical axis. Through with the central thickness control of fourth lens on the optical axis at reasonable within range for the easy injection moulding of fourth lens reduces the processing degree of difficulty of fourth lens. Preferably, 0.1 < CT5/CT4 < 1.0.

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

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

In the present embodiment, the optical lens group satisfies: SL/(T12+ T23) is more than 2.0 and less than or equal to 4.0, wherein SL is the axial 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 assembling stability of the optical lens group is favorably improved, the consistency of batch production is favorably realized, and the production yield of the optical lens group is favorably improved. Preferably, 2.1 < SL/(T12+ T23). ltoreq.4.0.

In the present embodiment, the optical lens group satisfies: 1.5 < TD/∑ ET < 2.0, where TD is the on-axis distance from the object-side surface of the first lens to the image-side surface of the last lens, and Σ ET is the sum of the edge thicknesses of all lenses of the optical lens group. By controlling the TD/Sigma ET within a reasonable range, the sensitivity of the optical lens group is favorably reduced, and the high-resolution characteristic of the optical lens group is favorably realized. Preferably, 1.6 < TD/. SIGMA ET < 2.0.

In the present embodiment, 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. The ratio of the combined focal length of the first lens and the second lens to the combined focal length of the second lens and the third lens is controlled within a reasonable range, so that the optical lens group can better balance aberration, and the resolution power of the optical lens group can be improved. Preferably, 0.2 < f12/f23 < 1.12.

In the present embodiment, the optical lens group satisfies: 2.0 < (SAG11+ SAG12)/ET1 < 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 and 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 and 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)/ET1 within a reasonable range, the first lens can be prevented from being bent too much, the processing difficulty is reduced, and the assembly of the optical lens group has higher stability. Preferably 2.05 < (SAG11+ SAG12)/ET1 < 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 the optical lens group can better balance aberration, and the improvement of the resolving power of the optical lens group can be facilitated. 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, and SAG51 is the on-axis distance between the intersection of the object-side surface and the optical axis of the fifth lens to the effective radius vertex of the object-side surface 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 expanding the obtained object information and expanding the shooting range of the optical lens group.

Example two

As shown in fig. 1 to 18, the image side of the optical lens group from the object side of the optical lens group includes: a first lens having a negative refractive power; a diaphragm; a second lens having a positive refractive power; a third lens having 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, wherein CT5 is the central thickness of the fifth lens on the optical axis of the optical lens group, and CT4 is the central thickness of the fourth lens on the optical axis.

The first lens is reasonably distributed to have negative refractive power, so that the optical lens group has the advantage of a large field angle, and the second lens is reasonably distributed to have positive refractive power, so that the field angle can be increased, and the off-axis aberration of the optical lens group can be corrected. The curvature radius 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. Through with the central thickness control of fourth lens on the optical axis at reasonable within range for the easy injection moulding of fourth lens reduces the processing degree of difficulty of fourth lens.

Preferably, 0.1 < CT5/CT4 < 1.0.

The optical lens group in the present application may employ a plurality of lenses, for example, the above five lenses. By reasonably distributing the refractive power, the surface shape, the central thickness of each lens, the axial distance between each lens and the like, the aperture of the optical lens group can be effectively increased, the sensitivity of the optical lens group can be reduced, and the machinability 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.

In the present application, at least one of the mirror surfaces of each lens is an aspherical mirror surface. The aspheric lens is characterized in that: the curvature varies continuously from the center of the lens to the periphery of the lens. Unlike a spherical lens having a constant curvature from the center of the lens to the periphery of the lens, an aspherical lens has better curvature radius characteristics, and has advantages of improving distortion aberration and improving astigmatic aberration. After the aspheric lens is adopted, the aberration generated during imaging can be eliminated as much as possible, thereby improving the imaging quality.

However, it will be appreciated by those skilled in the art that the number of lenses constituting an optical lens group may be varied to achieve the various results and advantages described in the present specification without departing from the claimed subject matter. For example, although five lenses are exemplified 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, as desired.

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

It should be noted that any one 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 of the first example 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, in order from an object side to an image side, comprises: 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 image forming surface S13.

The first lens E1 has negative refractive power, the radius of curvature of the object-side surface S1 of the first lens is negative, and the radius of curvature of the image-side surface S2 of the first lens is positive. The second lens element E2 has positive refractive power, the radius of curvature of the object-side surface S3 of the second lens element is positive, and the radius of curvature of the image-side surface S4 of the second lens element is negative. The third lens E3 has negative refractive power, and the radius of curvature of the object-side surface S5 of the third lens is positive, and the radius of curvature of the image-side surface S6 of the third lens is positive. The fourth lens E4 has positive refractive power, and the radius of curvature of the object-side surface S7 of the fourth lens is negative, and the radius of curvature of the image-side surface S8 of the fourth lens is negative. The fifth lens E5 has negative refractive power, and the radius of curvature of the object-side surface S9 of the fifth lens is positive, and the radius of curvature of the image-side surface S10 of the fifth lens is positive. Filter E6 has an object side S11 and an image side S12 of the filter. The 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 1.91 mm.

Table 1 shows a basic structural parameter table of the optical lens group of example one, in which the units of the radius of curvature, the thickness/distance, the focal length, and the 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 through the fifth lens element E5 are aspheric, and the surface shape of each aspheric lens can be defined by, but is not limited to, the following aspheric formula:

wherein x is the rise of the distance from the aspheric surface vertex to the aspheric surface vertex when the aspheric surface is at the position with the height of h along the optical axis direction; c is the paraxial curvature of the aspheric surface, c being 1/R (i.e., paraxial curvature c is the inverse of radius of curvature R in table 1 above); k is a conic coefficient; ai is the correction coefficient of the i-th order of the aspherical surface. Table 2 below gives the high-order coefficient 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.

Flour mark

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

Flour mark

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 on-axis chromatic aberration curves of the optical lens group of example one, which represent convergent focus deviations of light rays of different wavelengths after passing through the optical lens group. Fig. 3 shows astigmatism curves of the optical lens group of the first example, which represent meridional field curvature and sagittal field curvature.

As can be seen from fig. 2 and 3, the optical lens group given in 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, descriptions of parts similar to 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, in order from an object side to an image side, comprises: 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 image forming surface S13.

The first lens E1 has negative refractive power, the radius of curvature of the object-side surface S1 of the first lens is negative, and the radius of curvature of the image-side surface S2 of the first lens is positive. The second lens element E2 has positive refractive power, the radius of curvature of the object-side surface S3 of the second lens element is positive, and the radius of curvature of the image-side surface S4 of the second lens element is negative. The third lens E3 has negative refractive power, and the radius of curvature of the object-side surface S5 of the third lens is positive, and the radius of curvature of the image-side surface S6 of the third lens is positive. The fourth lens E4 has positive refractive power, and the radius of curvature of the object-side surface S7 of the fourth lens is positive, and the radius of curvature of the image-side surface S8 of the fourth lens is positive. The fifth lens E5 has positive refractive power, and the radius of curvature of the object-side surface S9 of the fifth lens is positive, and the radius of curvature of the image-side surface S10 of the fifth lens is positive. Filter E6 has an object side S11 and an image side S12 of the filter. The 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 1.91 mm.

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

TABLE 3

Table 4 shows the high-order term coefficients that can be used for each aspherical mirror surface in example two, wherein each aspherical mirror surface type can be defined by formula (1) given in example one above.

TABLE 4

Fig. 5 shows on-axis chromatic aberration curves of the optical lens groups of example two, which represent the deviation of the convergent focus of light rays of different wavelengths after passing through the optical lens groups. Fig. 6 shows astigmatism curves of the optical lens group of example two, which represent meridional field curvature and sagittal field curvature.

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

Example III

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, in order from an object side to an image side, comprises: 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 image forming surface S13.

The first lens E1 has negative refractive power, the radius of curvature of the object-side surface S1 of the first lens is negative, and the radius of curvature of the image-side surface S2 of the first lens is positive. The second lens element E2 has positive refractive power, the radius of curvature of the object-side surface S3 of the second lens element is positive, and the radius of curvature of the image-side surface S4 of the second lens element is negative. The third lens E3 has negative refractive power, and the radius of curvature of the object-side surface S5 of the third lens is positive, and the radius of curvature of the image-side surface S6 of the third lens is positive. The fourth lens E4 has positive refractive power, and the radius of curvature of the object-side surface S7 of the fourth lens is negative, and the radius of curvature of the image-side surface S8 of the fourth lens is negative. The fifth lens E5 has positive refractive power, and the radius of curvature of the object-side surface S9 of the fifth lens is positive, and the radius of curvature of the image-side surface S10 of the fifth lens is positive. Filter E6 has an object side S11 and an image side S12 of the filter. The 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 1.91 mm.

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

TABLE 5

Table 6 shows the high-order term coefficients that can be used for each aspherical mirror surface in example three, wherein each aspherical mirror surface type can be defined by formula (1) given in example one above.

TABLE 6

Fig. 8 shows on-axis chromatic aberration curves of the optical lens groups of example three, which represent convergent focus deviations of light rays of different wavelengths after passing through the optical lens groups. Fig. 9 shows astigmatism curves of the optical lens group of example three, which represent meridional field curvature and sagittal field 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, in order from an object side to an image side, comprises: 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 image forming surface S13.

The first lens E1 has negative refractive power, the radius of curvature of the object-side surface S1 of the first lens is negative, and the radius of curvature of the image-side surface S2 of the first lens is positive. The second lens element E2 has positive refractive power, the radius of curvature of the object-side surface S3 of the second lens element is positive, and the radius of curvature of the image-side surface S4 of the second lens element is negative. The third lens E3 has negative refractive power, and the radius of curvature of the object-side surface S5 of the third lens is positive, and the radius of curvature of the image-side surface S6 of the third lens is positive. The fourth lens E4 has negative refractive power, and the radius of curvature of the object-side surface S7 of the fourth lens is negative, and the radius of curvature of the image-side surface S8 of the fourth lens is negative. The fifth lens E5 has positive refractive power, and the radius of curvature of the object-side surface S9 of the fifth lens is positive, and the radius of curvature of the image-side surface S10 of the fifth lens is positive. Filter E6 has an object side S11 and an image side S12 of the filter. The 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 1.91 mm.

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

TABLE 7

Table 8 shows the high-order term coefficients that can be used for each aspherical mirror surface in example four, wherein each aspherical mirror surface type can be defined by formula (1) given in example one above.

Flour mark

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

Flour mark

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 on-axis chromatic aberration curves of the optical lens group of example four, which represent convergent focus deviations of light rays of different wavelengths after passing through the optical lens group. Fig. 12 shows astigmatism curves of the optical lens group of example four, which represent meridional field curvature and sagittal field 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, in order from an object side to an image side, comprises: 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 image forming surface S13.

The first lens E1 has negative refractive power, the radius of curvature of the object-side surface S1 of the first lens is negative, and the radius of curvature of the image-side surface S2 of the first lens is positive. The second lens element E2 has positive refractive power, the radius of curvature of the object-side surface S3 of the second lens element is positive, and the radius of curvature of the image-side surface S4 of the second lens element is negative. The third lens E3 has negative refractive power, and the radius of curvature of the object-side surface S5 of the third lens is positive, and the radius of curvature of the image-side surface S6 of the third lens is positive. The fourth lens E4 has positive refractive power, and the radius of curvature of the object-side surface S7 of the fourth lens is negative, and the radius of curvature of the image-side surface S8 of the fourth lens is negative. The fifth lens E5 has positive refractive power, and the radius of curvature of the object-side surface S9 of the fifth lens is a positive value, and the radius of curvature of the image-side surface S10 of the fifth lens is a negative value. Filter E6 has an object side S11 and an image side S12 of the filter. The 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 1.91 mm.

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

TABLE 9

Table 10 shows the high-order term coefficients that can be used for each aspherical mirror surface in example five, wherein each aspherical mirror surface type can be defined by formula (1) given in example one above.

Watch 10

Fig. 14 shows on-axis chromatic aberration curves of the optical lens groups of example five, which represent convergent focus deviations of light rays of different wavelengths after passing through the optical lens groups. Fig. 15 shows astigmatism curves of the optical lens group of example five, which represent meridional field curvature and sagittal field 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, in order from an object side to an image side, comprises: 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 image forming surface S13.

The first lens E1 has negative refractive power, the radius of curvature of the object-side surface S1 of the first lens is negative, and the radius of curvature of the image-side surface S2 of the first lens is positive. The second lens element E2 has positive refractive power, the radius of curvature of the object-side surface S3 of the second lens element is positive, and the radius of curvature of the image-side surface S4 of the second lens element is negative. The third lens E3 has negative refractive power, and the radius of curvature of the object-side surface S5 of the third lens is positive, and the radius of curvature of the image-side surface S6 of the third lens is positive. The fourth lens E4 has positive refractive power, and the radius of curvature of the object-side surface S7 of the fourth lens is positive and the radius of curvature of the image-side surface S8 of the fourth lens is negative. The fifth lens E5 has negative refractive power, and the radius of curvature of the object-side surface S9 of the fifth lens is negative and the radius of curvature of the image-side surface S10 of the fifth lens is positive. Filter E6 has an object side S11 and an image side S12 of the filter. The 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 1.91 mm.

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

TABLE 11

Table 12 shows the high-order term coefficients that can be used for each of the aspherical mirror surfaces in example six, wherein each aspherical mirror surface type can be defined by formula (1) given in example one above.

Flour mark

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

Flour mark

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 on-axis chromatic aberration curves of the optical lens group of example six, which represent convergent focus deviations of light rays of different wavelengths after passing through the optical lens group. Fig. 18 shows astigmatism curves of the optical lens group of example six, which represent meridional field curvature and sagittal field curvature.

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

To sum up, examples one to seven respectively satisfy the relationships shown in table 13.

Conditions/examples	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 effective focal lengths f of the optical lens groups of example one to example six, and 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 present application also provides an imaging device whose electron photosensitive element may be a photo-coupled device (CCD) or a complementary metal oxide semiconductor device (CMOS). The imaging device may be a stand-alone imaging device such as a digital camera, or may be an imaging module integrated on a mobile electronic device such as a mobile phone. The imaging device is equipped with the optical lens group described above.

It is to be understood that the above-described embodiments are only a few, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

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

It should be noted that the terms "first," "second," and the like in the description and claims of this application and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the application described herein are capable of operation in sequences other than those illustrated or described herein.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement 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 lens group, comprising, 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 a positive refractive power;

a third lens having 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:

1.0＜R3/f2＜2.0

wherein R3 is the radius of curvature of the object-side surface of the second lens, and f2 is the effective focal length of the second lens.

2. An optical lens group according to claim 1, characterized in that it satisfies: 0.2 < CT4 ≦ 0.8, wherein CT4 is a central thickness of the fourth lens on an optical axis of the optical lens group.

3. An optical lens group according to claim 1, characterized in that it satisfies: 0 < CT5/CT4 < 1.2, wherein CT5 is a central thickness of the fifth lens on an optical axis of the optical lens group, and CT4 is a central thickness of the fourth lens on the optical axis.

4. An optical lens group according to claim 1, characterized in that it satisfies: 1.5 < (T12+ CT1)/(T12-CT1) < 3.0, wherein CT1 is a central thickness of the first lens on an optical axis of the optical lens group, and T12 is an air space of the first lens and the second lens on the optical axis.

5. An optical lens group according to claim 1, characterized in that it satisfies: 2.5 < SD/CT4 < 4.6, wherein SD is the distance from the diaphragm to the image side of the last lens, and CT4 is the central thickness of the fourth lens on the optical axis of the optical lens group.

6. An optical lens group according to claim 1, characterized in that it satisfies: 2.0 < SL/(T12+ T23) ≦ 4.0, wherein SL is an on-axis distance from the diaphragm to an imaging surface of the optical lens group, T12 is an air space between the first lens and the second lens on an optical axis of the optical lens group, and T23 is an air space between the second lens and the third lens on the optical axis.

7. An optical lens group according to claim 1, characterized in that it satisfies: 1.5 < TD/∑ ET < 2.0, where TD is the on-axis distance from the object-side surface of the first lens to the image-side surface of the last lens, and Σ ET is the sum of the edge thicknesses of all lenses of the optical lens group.

8. An optical lens group according to claim 1, characterized in that it satisfies: 0 < f12/f23 < 1.2, wherein f12 is a combined focal length of the first lens and the second lens, and f23 is a combined focal length of the second lens and the third lens.

9. An optical lens group according to claim 1, characterized in that it satisfies: 2.0 < (SAG11+ SAG12)/ET1 < 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 and 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 and an effective radius vertex of the image side surface of the first lens, and ET1 is an edge thickness of the first lens.

10. An optical lens group, comprising, 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 a positive refractive power;

a fourth lens having refractive power;

a fifth lens having refractive power;

the optical lens group satisfies:

0 < CT5/CT4 < 1.2, wherein CT5 is a central thickness of the fifth lens on an optical axis of the optical lens group, and CT4 is a central thickness of the fourth lens on the optical axis.