CN110262014B - Optical imaging lens group - Google Patents

Abstract

The application discloses an optical imaging lens group, which sequentially comprises the following components from an object side to an image side along an optical axis: a diaphragm; a first lens having optical power; a second lens having optical power, an image side surface of which is convex; the object side surface of the third lens is a concave surface, and the image side surface of the third lens is a convex surface; a fourth lens element with optical power, wherein an object-side surface thereof is convex, an image-side surface thereof is concave, and at least one of the object-side surface and the image-side surface of the fourth lens element has an inflection point; the fifth lens is provided with positive focal power, and the image side surface of the fifth lens is provided with an inflection point. The distance TTL from the object side surface of the first lens element of the optical imaging lens group to the imaging surface of the optical imaging lens group on the optical axis, the total effective focal length f of the optical imaging lens group, and half of the diagonal length ImgH of the effective pixel area on the imaging surface satisfy: 3.50mm < ImgH/fXTTL < 5.00mm.

Description

Optical imaging lens group

Technical Field

The present application relates to an optical imaging lens group, and more particularly, to an optical imaging lens group including five lenses.

Background

With the continuous improvement of the technical capability of portable electronic devices, the current trend of using mobile phone to pick up images instead of traditional cameras is more and more obvious, and the masses are more and more favoured for mobile phones with high-quality photographing function. In order to provide high-quality photographing function for users in all directions, the currently mainstream lens group is a combination of an ultrathin large-image-surface lens, a long-focus lens and a wide-angle lens, wherein the wide-angle lens has the characteristics of large angle of view and long scene, so that a long-range view is easy to be provided for a photographer, the infection of a picture is facilitated to be enhanced, and the photographer has an immersive feeling.

Disclosure of Invention

An aspect of the present application provides an optical imaging lens group including, in order from an object side to an image side along an optical axis: a diaphragm; a first lens having optical power; a second lens having optical power, an image side surface of which is convex; the object side surface of the third lens is a concave surface, and the image side surface of the third lens is a convex surface; a fourth lens element with optical power having a convex object-side surface and a concave image-side surface, wherein at least one of the object-side surface and the image-side surface of the fourth lens element has an inflection point; and a fifth lens with positive focal power, wherein the image side surface of the fifth lens is provided with an inflection point.

In one embodiment, the distance TTL between the object side surface of the first lens element and the imaging surface of the optical imaging lens group on the optical axis, the total effective focal length f of the optical imaging lens group, and half of the diagonal length ImgH of the effective pixel area on the imaging surface of the optical imaging lens group may satisfy: 3.50mm < ImgH/fXTTL < 5.00mm.

In one embodiment, the maximum half field angle Semi-FOV of the optical imaging lens group may satisfy: the Semi-FOV is more than 53.0 degrees.

In one embodiment, the total effective focal length f of the optical imaging lens group and the effective focal length f5 of the fifth lens may satisfy: 0.50 < f5/f < 2.50.

In one embodiment, the total effective focal length f of the optical imaging lens group and the radius of curvature R9 of the object side surface of the fifth lens element may satisfy: 1.00 < f/R9 < 3.50.

In one embodiment, the radius of curvature R4 of the image side of the second lens and the radius of curvature R5 of the object side of the third lens may satisfy: 2.00 < (R4+R5)/(R4-R5) < 3.50.

In one embodiment, the center thickness CT4 of the fourth lens on the optical axis and the separation distance T45 of the fourth lens and the fifth lens on the optical axis may satisfy: CT4/T45 is more than 4.00 and less than 10.50.

In one embodiment, the on-axis distance SAG31 from the intersection of the object side surface of the third lens and the optical axis to the vertex of the effective radius of the object side surface of the third lens and the on-axis distance SAG32 from the intersection of the image side surface of the third lens and the optical axis to the vertex of the effective radius of the image side surface of the third lens may satisfy: 12.00 < (SAG31+SAG32)/(SAG 31-SAG 32) < 30.50.

In one embodiment, the center thickness CT2 of the second lens on the optical axis and the separation distance T23 of the second lens and the third lens on the optical axis may satisfy: CT2/T23 is less than 2.50 and less than 6.00.

In one embodiment, the sum Σat of the distance TD between the object side surface of the first lens element and the image side surface of the fifth lens element on the optical axis and the distance between any two adjacent lens elements of the first lens element and the fifth lens element on the optical axis may satisfy: sigma AT/TD < 0.20.

In one embodiment, the distance T34 between the third lens element and the fourth lens element on the optical axis and half of the diagonal length of the effective pixel area on the imaging plane of the optical imaging lens group may satisfy: 1.00 < 100 xT 34/ImgH < 3.00.

The application adopts five aspheric lenses, and the optical imaging lens group has at least one beneficial effect of ultra-thin, ultra-small head, high imaging quality and the like by reasonably distributing the focal power, the surface type, the center thickness of each lens, the axial spacing among the lenses and the like.

Drawings

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

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

Fig. 2A to 2D show an on-axis chromatic aberration curve, an astigmatic curve, a distortion curve, and a magnification chromatic aberration curve, respectively, of the optical imaging lens group of embodiment 1;

Fig. 3 is a schematic diagram showing the structure of an optical imaging lens group according to embodiment 2 of the present application;

Fig. 4A to 4D show an on-axis chromatic aberration curve, an astigmatic curve, a distortion curve, and a magnification chromatic aberration curve, respectively, of the optical imaging lens group of embodiment 2;

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

Fig. 6A to 6D show an on-axis chromatic aberration curve, an astigmatic curve, a distortion curve, and a magnification chromatic aberration curve, respectively, of the optical imaging lens group of embodiment 3;

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

Fig. 8A to 8D show an on-axis chromatic aberration curve, an astigmatic curve, a distortion curve, and a magnification chromatic aberration curve, respectively, of the optical imaging lens group of embodiment 4;

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

Fig. 10A to 10D show an on-axis chromatic aberration curve, an astigmatic curve, a distortion curve, and a magnification chromatic aberration curve, respectively, of the optical imaging lens group of embodiment 5;

fig. 11 shows a schematic structural view of an optical imaging lens group according to embodiment 6 of the present application;

fig. 12A to 12D show an on-axis chromatic aberration curve, an astigmatism curve, a distortion curve, and a magnification chromatic aberration curve, respectively, of the optical imaging lens group of embodiment 6.

Detailed Description

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

It should be noted that in 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. In particular, 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 closest to the object is referred to as the object side of the lens, and the surface of each lens closest to the imaging plane is referred to as the image side of the lens.

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

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

It should be noted that, 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.

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

The optical imaging lens group according to the exemplary embodiment of the present application may include, for example, five lenses having optical power, which are a first lens, a second lens, a third lens, a fourth lens, and a fifth lens, respectively. The five lenses are arranged in order from the object side to the image side along the optical axis. Any two adjacent lenses in the first lens to the fifth lens can have a spacing distance.

In an exemplary embodiment, the first lens has optical power; the second lens has optical power, and the image side surface of the second lens is a convex surface; the third lens has optical power, the object side surface of the third lens is concave, and the image side surface of the third lens is convex; the fourth lens is provided with focal power, the object side surface of the fourth lens is a convex surface, the image side surface of the fourth lens is a concave surface, and at least one of the object side surface and the image side surface of the fourth lens is provided with an inflection point; and the fifth lens can have positive focal power, and the image side surface of the fifth lens has an inflection point.

The second lens element with convex image-side surface, the third lens element with concave object-side surface and convex image-side surface is designed to enhance the FOV of the system, and to better collect the light rays and improve the image quality of the system. The convex-concave surface of the fourth lens is mainly used for enabling the light rays of the central view field to have good convergence capacity and improving the spherical aberration of the system. The object side surface and/or the image side surface of the fourth lens are/is guaranteed to have at least one inflection point, the image side surface of the fifth lens is guaranteed to have at least one inflection point, and the fifth lens is guaranteed to have positive focal power, so that the phenomenon that marginal view field rays are too divergent can be avoided, and the system has better coma correction capability.

In an exemplary embodiment, the optical imaging lens group according to the present application further includes a diaphragm disposed between the object side and the first lens.

In an exemplary embodiment, the optical imaging lens group according to the present application may satisfy: 3.50mm < ImgH/f x TTL < 5.00mm, wherein TTL is the distance between the object side surface of the first lens and the imaging surface of the optical imaging lens group on the optical axis, f is the total effective focal length of the optical imaging lens group, and ImgH is half of the diagonal length of the effective pixel area on the imaging surface of the optical imaging lens group. More specifically, TTL, f and ImgH may further satisfy 3.6mm < ImgH/fXTTL < 4.60mm. The optical imaging lens group meets the requirements of 3.50mm < ImgH/fxTTL < 5.00mm, not only can the system FOV be improved, but also the overlength of the system optical total length can be avoided, and the optical imaging lens group has good practicability.

In an exemplary embodiment, the optical imaging lens group according to the present application may satisfy: the Semi-FOV is more than 53.0 degrees, wherein the Semi-FOV is the maximum half field angle of the optical imaging lens group. More specifically, the Semi-FOV may further satisfy a Semi-FOV > 53.2. Meets the requirement that the Semi-FOV is more than 53.0 degrees, and can improve the wide-angle advantage of the optical imaging lens group, so that the lens group has a wider imaging range.

In an exemplary embodiment, the optical imaging lens group according to the present application may satisfy: 0.50 < f5/f < 2.50, wherein f is the total effective focal length of the optical imaging lens group, and f5 is the effective focal length of the fifth lens. More specifically, f and f5 may further satisfy 0.70 < f5/f < 2.10. Satisfies 0.50 < f5/f < 2.50, can avoid the processing difficulty of the fifth lens due to the excessive light converging function, and can avoid the possibility of poor imaging effect due to the overlarge system depth of field of the optical imaging lens group.

In an exemplary embodiment, the optical imaging lens group according to the present application may satisfy: 1.00 < f/R9 < 3.50, wherein f is the total effective focal length of the optical imaging lens group, and R9 is the radius of curvature of the object side surface of the fifth lens. More specifically, f and R9 may further satisfy 1.40 < f/R9 < 3.48. The f/R9 is less than 1.00 and less than 3.50, so that the problem that the fifth lens is difficult to process due to the fact that the curvature radius of the object side surface of the fifth lens is too small can be avoided, and the problem that the imaging quality is poor due to the fact that the optical imaging lens group cannot support a larger FOV due to the fact that the curvature radius of the object side surface of the fifth lens is too large can be avoided.

In an exemplary embodiment, the optical imaging lens group according to the present application may satisfy: 2.00 < (R4+R5)/(R4-R5) < 3.50, wherein R4 is the radius of curvature of the image side of the second lens and R5 is the radius of curvature of the object side of the third lens. More specifically, R4 and R5 may further satisfy 2.02 < (R4+R5)/(R4-R5) < 3.20. Satisfies 2.00 < (R4+R5)/(R4-R5) < 3.50, is favorable for better converging incident light rays, is favorable for avoiding the problems of difficult processing and the like caused by excessive bending of the lens surface, and can also effectively enhance the practicability of the imaging lens group.

In an exemplary embodiment, the optical imaging lens group according to the present application may satisfy: 4.00 < CT4/T45 < 10.50, wherein CT4 is the center thickness of the fourth lens on the optical axis, and T45 is the interval distance between the fourth lens and the fifth lens on the optical axis. More specifically, CT4 and T45 may further satisfy 4.15 < CT4/T45 < 10.05. The lens group satisfies that CT4/T45 is smaller than 10.50 and is more than 4.00, and can not only effectively avoid ghost images between the fourth lens and the fifth lens, but also enable the optical imaging lens group to have better spherical aberration and distortion correction functions.

In an exemplary embodiment, the optical imaging lens group according to the present application may satisfy: 12.00 < (SAG31+SAG32)/(SAG 31-SAG 32) < 30.50, wherein SAG31 is an on-axis distance from an intersection point of the object side surface of the third lens and the optical axis to an apex of an effective radius of the object side surface of the third lens, and SAG32 is an on-axis distance from an intersection point of the image side surface of the third lens and the optical axis to an apex of an effective radius of the image side surface of the third lens. More specifically, SAG31 and SAG32 may further satisfy 12.25 < (SAG31+SAG32)/(SAG 31-SAG 32) < 30.15. The requirement that (SAG31+SAG32)/(SAG 31-SAG 32) < 30.50 is satisfied, the third lens is prevented from being excessively bent, the processing difficulty is reduced, and the optical imaging lens group can be assembled with higher stability.

In an exemplary embodiment, the optical imaging lens group according to the present application may satisfy: CT2/T23 is less than 6.00 and 2.50, wherein CT2 is the center thickness of the second lens on the optical axis, and T23 is the interval distance between the second lens and the third lens on the optical axis. More specifically, CT2 and T23 may further satisfy 2.75 < CT2/T23 < 5.60. The lens satisfies that CT2/T23 is less than 2.50 and less than 6.00, can effectively avoid ghost images generated between the second lens and the third lens, and can ensure that the optical imaging lens group has better spherical aberration and distortion correction functions.

In an exemplary embodiment, the optical imaging lens group according to the present application may satisfy: and (S) AT/TD < 0.20, wherein S AT is the sum of the spacing distances of any two adjacent lenses in the first lens element to the fifth lens element on the optical axis, and TD is the distance from the object side surface of the first lens element to the image side surface of the fifth lens element on the optical axis. More specifically, sigma AT and TD may further satisfy 1.0 < SigmaAT/TD < 2.0. The air interval of each lens on the optical axis is reasonably distributed, so that the processing and assembling characteristics can be guaranteed, meanwhile, the light deflection is slowed down, the field curvature of the optical imaging lens group is adjusted, the sensitivity degree is reduced, and better imaging quality is further obtained.

In an exemplary embodiment, the optical imaging lens group according to the present application may satisfy: TTL/ImgH > 1.40, wherein TTL is the distance between the object side surface of the first lens and the imaging surface of the optical imaging lens group on the optical axis, and ImgH is half of the diagonal length of the effective pixel area on the imaging surface of the optical imaging lens group. More specifically, TTL and ImgH can further satisfy TTL/ImgH > 1.43. The TTL/ImgH is more than 1.40, so that the imaging definition of the optical imaging lens group can be effectively improved, the overlength of the optical total length of the optical imaging lens group can be avoided, and the application of the optical imaging lens group in portable electronic equipment is facilitated.

In an exemplary embodiment, the optical imaging lens group according to the present application may satisfy: 1.00 < 100×T34/ImgH < 3.00, wherein T34 is the distance between the third lens and the fourth lens on the optical axis, and ImgH is half of the diagonal length of the effective pixel region on the imaging surface of the optical imaging lens group. More specifically, T34 and ImgH may further satisfy 1.20 < 100×T34/ImgH < 2.60. Satisfies 1.00 < 100 xT 34/ImgH < 3.00, can effectively correct the field curvature of the optical imaging lens group and improve the ghost risks between the last two lenses and the second and third lenses while improving the imaging definition.

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

The application provides an optical imaging lens group with an ultra-small head and adopting an aspheric surface. The optical imaging lens group according to the above embodiment of the present application may employ a plurality of lenses, for example, five lenses as described above. By reasonably distributing the focal power, the surface shape, the center thickness of each lens, the axial spacing between each lens and the like of each lens, incident light rays can be effectively converged, the optical total length of the imaging lens group is reduced, and the processability of the imaging lens group is improved, so that the optical imaging lens group is more beneficial to production and processing. The optical imaging lens group provided by the application has the ultra-small head, can greatly reduce the front end opening of the lens, and is suitable for being configured under a mobile phone screen.

In an embodiment of the present application, at least one of the mirrors of each lens is an aspherical mirror, i.e., at least one of the object side surface of the first lens to the image side surface of the fifth lens is an aspherical mirror. The aspherical lens is characterized in that: the curvature varies continuously from the center of the lens to the periphery of the lens. Unlike a spherical lens having a constant curvature from the center of the lens to the periphery of the lens, an aspherical lens has a better radius of curvature characteristic, and has advantages of improving distortion aberration and improving astigmatic aberration. By adopting the aspherical lens, aberration occurring at the time of imaging can be eliminated as much as possible, thereby improving imaging quality. Optionally, at least one of an object side surface and an image side surface of each of the first lens, the second lens, the third lens, the fourth lens, and the fifth lens is an aspherical mirror surface. Optionally, the object side surface and the image side surface of each of the first lens, the second lens, the third lens, the fourth lens and the fifth lens are aspherical mirror surfaces.

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

Specific examples of the optical imaging lens applicable to the above-described embodiments are further described below with reference to the accompanying drawings.

Example 1

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

As shown in fig. 1, the optical imaging lens assembly sequentially includes, from an object side to an image side: an aperture stop STO, a first lens E1, a field stop ST, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, an optical filter E6, and an imaging surface S13.

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

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

TABLE 1

In this example, the total effective focal length f of the optical imaging lens group is 1.82mm, the total length TTL of the optical imaging lens group (i.e., the distance on the optical axis from the object side surface S1 of the first lens E1 to the imaging surface S13 of the optical imaging lens group) is 3.45mm, the half of the diagonal length ImgH of the effective pixel area on the imaging surface S13 of the optical imaging lens group is 2.40mm, the maximum half field angle Semi-FOV of the optical imaging lens group is 61.3 °, and the aperture value Fno is 2.50.

In embodiment 1, the object side surface and the image side surface of any one of the first lens E1 to the fifth lens E5 are aspherical, and the surface profile x of each aspherical lens can be defined by, but not limited to, the following aspherical formula:

Wherein x is the distance vector height from the vertex of the aspheric surface when the aspheric surface is at the position with the height h along the optical axis direction; c is the paraxial curvature of the aspheric surface, c=1/R (i.e., paraxial curvature c is the inverse of radius of curvature R in table 1 above); k is a conic coefficient; ai is the correction coefficient of the aspherical i-th order. The following Table 2 shows the higher order coefficients A4, A6, A8, A10, A12, A14, A16, A18 and A20 that can be used for each of the aspherical mirrors S1-S10 in example 1.

TABLE 2

Fig. 2A shows an on-axis chromatic aberration curve of the optical imaging lens group of embodiment 1, which indicates a convergent focus deviation after light rays of different wavelengths pass through the lens. Fig. 2B shows an astigmatism curve of the optical imaging lens group of embodiment 1, which represents meridional image plane curvature and sagittal image plane curvature. Fig. 2C shows a distortion curve of the optical imaging lens group of embodiment 1, which represents distortion magnitude values corresponding to different angles of view. Fig. 2D shows a magnification chromatic aberration curve of the optical imaging lens group of embodiment 1, which represents the deviation of different image heights on the imaging plane after light passes through the lens. As can be seen from fig. 2A to 2D, the optical imaging lens group of embodiment 1 can achieve good imaging quality.

Example 2

An optical imaging lens group according to embodiment 2 of the present application is described below with reference to fig. 3 to 4D. In this embodiment and the following embodiments, descriptions of portions similar to embodiment 1 will be omitted for brevity. Fig. 3 shows a schematic configuration diagram of an optical imaging lens group according to embodiment 2 of the present application.

As shown in fig. 3, the optical imaging lens assembly sequentially includes, from an object side to an image side: an aperture stop STO, a first lens E1, a field stop ST, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, an optical filter E6, and an imaging surface S13.

The first lens element E1 has positive refractive power, wherein an object-side surface S1 thereof is convex, and an image-side surface S2 thereof is convex. The second lens element E2 has positive refractive power, wherein an object-side surface S3 thereof is convex, and an image-side surface S4 thereof is convex. The third lens element E3 has negative refractive power, wherein an object-side surface S5 thereof is concave and an image-side surface S6 thereof is convex. The fourth lens element E4 has positive refractive power, wherein an object-side surface S7 thereof is convex, and an image-side surface S8 thereof is concave. The fifth lens element E5 has positive refractive power, wherein an object-side surface S9 thereof is convex, and an image-side surface S10 thereof is concave. The filter E6 has an object side surface S11 and an image side surface S12. 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 imaging lens group is 1.71mm, the total length TTL of the optical imaging lens group is 3.48mm, the half of the diagonal length ImgH of the effective pixel region on the imaging surface S13 of the optical imaging lens group is 2.20mm, the maximum half field angle Semi-FOV of the optical imaging lens group is 58.9 °, and the aperture value Fno is 2.50.

Table 3 shows the basic parameter table of the optical imaging lens group of embodiment 2, in which the units of radius of curvature, thickness/distance, and focal length are all millimeters (mm). Table 4 shows the higher order coefficients that can be used for each of the aspherical mirror surfaces in example 2, wherein each of the aspherical surface types can be defined by the formula (1) given in example 1 above.

TABLE 3 Table 3

Face number

A4

A6

A8

A10

A12

A14

A16

A18

A20

S1

2.9889E-01

-4.7863E+01

2.4615E+03

-7.6021E+04

1.4468E+06

-1.7062E+07

1.2106E+08

-4.7200E+08

7.7472E+08

S2

-2.1511E-01

-2.9051E+00

-1.5320E+02

4.3802E+03

-5.5829E+04

3.9540E+05

-1.6011E+06

3.4722E+06

-3.1283E+06

S3

-1.4498E-01

-1.3678E+01

2.6184E+02

-3.4548E+03

2.8062E+04

-1.4174E+05

4.2967E+05

-7.1179E+05

4.9531E+05

S4

-1.1992E+00

1.3403E+00

-1.2839E-01

-1.9717E+01

1.4153E+02

-5.4153E+02

1.0912E+03

-1.0732E+03

4.1038E+02

S5

-5.4189E-01

-3.1751E+00

1.8252E+01

2.2945E+01

-4.0356E+02

1.3295E+03

-2.0957E+03

1.6554E+03

-5.2755E+02

S6

3.0654E-01

-6.7923E+00

3.6661E+01

-1.0564E+02

1.8819E+02

-2.1464E+02

1.5276E+02

-6.1823E+01

1.0918E+01

S7

-3.3115E-01

-4.6922E-01

3.2400E+00

-7.1361E+00

8.8256E+00

-6.6960E+00

3.0536E+00

-7.6365E-01

8.0332E-02

S8

-4.5540E-02

-4.4932E-01

1.1138E+00

-1.2710E+00

8.1430E-01

-3.1078E-01

7.0347E-02

-8.7362E-03

4.5903E-04

S9

-1.8310E-01

6.0459E-01

-1.3911E+00

1.4779E+00

-8.7025E-01

3.0648E-01

-6.4659E-02

7.5711E-03

-3.7944E-04

S10

3.6052E-01

-7.0476E-01

5.8241E-01

-2.6085E-01

5.2063E-02

3.8195E-03

-3.9874E-03

7.1268E-04

-4.2611E-05

TABLE 4 Table 4

Fig. 4A shows an on-axis chromatic aberration curve of the optical imaging lens group of embodiment 2, which indicates a convergent focus deviation after light rays of different wavelengths pass through the lens. Fig. 4B shows an astigmatism curve of the optical imaging lens group of embodiment 2, which represents meridional image plane curvature and sagittal image plane curvature. Fig. 4C shows a distortion curve of the optical imaging lens group of embodiment 2, which represents distortion magnitude values corresponding to different angles of view. Fig. 4D shows a magnification chromatic aberration curve of the optical imaging lens group of embodiment 2, which represents the deviation of different image heights on the imaging plane after light passes through the lens. As can be seen from fig. 4A to 4D, the optical imaging lens group according to embodiment 2 can achieve good imaging quality.

Example 3

An optical imaging lens group according to embodiment 3 of the present application is described below with reference to fig. 5 to 6D. Fig. 5 shows a schematic configuration diagram of an optical imaging lens group according to embodiment 3 of the present application.

As shown in fig. 5, the optical imaging lens assembly sequentially includes, from an object side to an image side: an aperture stop STO, a first lens E1, a field stop ST, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, an optical filter E6, and an imaging surface S13.

The first lens element E1 has positive refractive power, wherein an object-side surface S1 thereof is convex, and an image-side surface S2 thereof is concave. The second lens element E2 has positive refractive power, wherein an object-side surface S3 thereof is convex, and an image-side surface S4 thereof is convex. The third lens element E3 has negative refractive power, wherein an object-side surface S5 thereof is concave and an image-side surface S6 thereof is convex. The fourth lens element E4 has negative refractive power, wherein an object-side surface S7 thereof is convex and an image-side surface S8 thereof is concave. The fifth lens element E5 has positive refractive power, wherein an object-side surface S9 thereof is convex, and an image-side surface S10 thereof is convex. The filter E6 has an object side surface S11 and an image side surface S12. 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 imaging lens group is 2.13mm, the total length TTL of the optical imaging lens group is 3.64mm, the half of the diagonal length ImgH of the effective pixel region on the imaging surface S13 of the optical imaging lens group is 2.40mm, the maximum half field angle Semi-FOV of the optical imaging lens group is 53.6 °, and the aperture value Fno is 2.30.

Table 5 shows the basic parameter table of the optical imaging lens group of embodiment 3, in which the units of radius of curvature, thickness/distance, and focal length are all millimeters (mm). Table 6 shows the higher order coefficients that can be used for each of the aspherical mirror surfaces in example 3, wherein each of the aspherical surface types can be defined by the formula (1) given in example 1 above.

TABLE 5

TABLE 6

Fig. 6A shows an on-axis chromatic aberration curve of the optical imaging lens group of embodiment 3, which indicates a convergent focus deviation after light rays of different wavelengths pass through the lens. Fig. 6B shows an astigmatism curve of the optical imaging lens group of embodiment 3, which represents meridional image plane curvature and sagittal image plane curvature. Fig. 6C shows a distortion curve of the optical imaging lens group of embodiment 3, which represents distortion magnitude values corresponding to different angles of view. Fig. 6D shows a magnification chromatic aberration curve of the optical imaging lens group of embodiment 3, which represents the deviation of different image heights on the imaging plane after light passes through the lens. As can be seen from fig. 6A to 6D, the optical imaging lens group provided in embodiment 3 can achieve good imaging quality.

Example 4

An optical imaging lens group according to embodiment 4 of the present application is described below with reference to fig. 7 to 8D. Fig. 7 shows a schematic configuration diagram of an optical imaging lens group according to embodiment 4 of the present application.

As shown in fig. 7, the optical imaging lens assembly sequentially includes, from an object side to an image side: an aperture stop STO, a first lens E1, a field stop ST, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, an optical filter E6, and an imaging surface S13.

The first lens element E1 has negative refractive power, wherein an object-side surface S1 thereof is concave, and an image-side surface S2 thereof is convex. The second lens element E2 has positive refractive power, wherein an object-side surface S3 thereof is convex, and an image-side surface S4 thereof is convex. The third lens element E3 has negative refractive power, wherein an object-side surface S5 thereof is concave and an image-side surface S6 thereof is convex. The fourth lens element E4 has positive refractive power, wherein an object-side surface S7 thereof is convex, and an image-side surface S8 thereof is concave. The fifth lens element E5 has positive refractive power, wherein an object-side surface S9 thereof is convex, and an image-side surface S10 thereof is concave. The filter E6 has an object side surface S11 and an image side surface S12. 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 imaging lens group is 1.80mm, the total length TTL of the optical imaging lens group is 3.55mm, the half of the diagonal length ImgH of the effective pixel region on the imaging surface S13 of the optical imaging lens group is 1.85mm, the maximum half field angle Semi-FOV of the optical imaging lens group is 53.3 °, and the aperture value Fno is 2.10.

Table 7 shows a basic parameter table of the optical imaging lens group of embodiment 4, in which the units of radius of curvature, thickness/distance, and focal length are all millimeters (mm). Table 8 shows the higher order coefficients that can be used for each of the aspherical mirror surfaces in example 4, wherein each of the aspherical surface types can be defined by the formula (1) given in example 1 above.

TABLE 7

Face number

A4

A6

A8

A10

A12

A14

A16

A18

A20

S1

-5.4839E-01

1.5054E+01

-4.9229E+02

9.4273E+03

-1.1166E+05

8.2990E+05

-3.7724E+06

9.5867E+06

-1.0427E+07

S2

7.7192E-02

-3.5620E+01

6.5718E+02

-6.9068E+03

4.4505E+04

-1.7863E+05

4.3512E+05

-5.8711E+05

3.3592E+05

S3

8.9764E-02

-1.1331E+01

1.2776E+02

-9.8712E+02

4.9972E+03

-1.6860E+04

3.6012E+04

-4.3158E+04

2.1873E+04

S4

-8.0080E-01

-2.8419E+00

3.5963E+01

-1.9221E+02

5.6326E+02

-9.6459E+02

9.5608E+02

-5.0131E+02

1.0514E+02

S5

-1.7487E-01

-6.8244E+00

6.2026E+01

-2.8471E+02

7.7038E+02

-1.2555E+03

1.2121E+03

-6.3940E+02

1.4214E+02

S6

2.8217E-02

-2.4449E+00

1.1914E+01

-2.8228E+01

3.8023E+01

-2.8908E+01

1.0534E+01

-5.1870E-01

-4.6989E-01

S7

-3.3329E-01

1.4558E-01

4.9739E-01

-1.1467E+00

1.2335E+00

-8.8705E-01

4.1589E-01

-1.0924E-01

1.1945E-02

S8

-7.5938E-03

-6.0336E-01

1.5629E+00

-1.9039E+00

1.2674E+00

-4.8916E-01

1.0945E-01

-1.3189E-02

6.6268E-04

S9

-2.0984E-02

-2.5398E-01

1.2557E-01

1.5455E-01

-2.0073E-01

9.7326E-02

-2.4172E-02

3.0447E-03

-1.5346E-04

S10

5.0559E-01

-1.4641E+00

2.1167E+00

-1.9412E+00

1.1554E+00

-4.3551E-01

9.8821E-02

-1.2221E-02

6.3013E-04

TABLE 8

Fig. 8A shows an on-axis chromatic aberration curve of the optical imaging lens group of embodiment 4, which indicates a convergent focus deviation after light rays of different wavelengths pass through the lens. Fig. 8B shows an astigmatism curve of the optical imaging lens group of embodiment 4, which represents meridional image plane curvature and sagittal image plane curvature. Fig. 8C shows a distortion curve of the optical imaging lens group of embodiment 4, which represents distortion magnitude values corresponding to different angles of view. Fig. 8D shows a magnification chromatic aberration curve of the optical imaging lens group of embodiment 4, which represents the deviation of different image heights on the imaging plane after light passes through the lens. As can be seen from fig. 8A to 8D, the optical imaging lens group provided in embodiment 4 can achieve good imaging quality.

Example 5

An optical imaging lens group according to embodiment 5 of the present application is described below with reference to fig. 9 to 10D. Fig. 9 shows a schematic configuration diagram of an optical imaging lens group according to embodiment 5 of the present application.

As shown in fig. 9, the optical imaging lens assembly sequentially includes, from an object side to an image side: an aperture stop STO, a first lens E1, a field stop ST, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, an optical filter E6, and an imaging surface S13.

The first lens element E1 has positive refractive power, wherein an object-side surface S1 thereof is convex, and an image-side surface S2 thereof is concave. The second lens element E2 has positive refractive power, wherein an object-side surface S3 thereof is concave and an image-side surface S4 thereof is convex. The third lens element E3 has negative refractive power, wherein an object-side surface S5 thereof is concave and an image-side surface S6 thereof is convex. The fourth lens element E4 has negative refractive power, wherein an object-side surface S7 thereof is convex and an image-side surface S8 thereof is concave. The fifth lens element E5 has positive refractive power, wherein an object-side surface S9 thereof is convex, and an image-side surface S10 thereof is convex. The filter E6 has an object side surface S11 and an image side surface S12. 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 imaging lens group is 2.06mm, the total length TTL of the optical imaging lens group is 3.60mm, the half of the diagonal length ImgH of the effective pixel region on the imaging surface S13 of the optical imaging lens group is 2.40mm, the maximum half field angle Semi-FOV of the optical imaging lens group is 55.4 °, and the aperture value Fno is 2.37.

Table 9 shows a basic parameter table of the optical imaging lens group of embodiment 5, in which the units of radius of curvature, thickness/distance, and focal length are all millimeters (mm). Table 10 shows the higher order coefficients that can be used for each of the aspherical mirror surfaces in example 5, wherein each of the aspherical surface types can be defined by the formula (1) given in example 1 above.

TABLE 9

Face number

A4

A6

A8

A10

A12

A14

A16

A18

A20

S1

-2.0587E-01

4.0327E+00

-1.4275E+02

2.6905E+03

-3.0983E+04

2.2109E+05

-9.5451E+05

2.2845E+06

-2.3284E+06

S2

-5.4475E-01

2.2266E-01

-7.9216E+00

-2.5248E+01

9.0714E+02

-7.4585E+03

3.0248E+04

-6.1177E+04

4.8662E+04

S3

-7.3912E-01

3.0662E+00

-7.9170E+01

9.0923E+02

-6.9425E+03

3.3647E+04

-1.0131E+05

1.7431E+05

-1.3083E+05

S4

-9.6613E-01

-1.8968E+00

1.7884E+01

-9.1969E+01

3.0257E+02

-5.8855E+02

5.9891E+02

-2.0803E+02

-5.1866E+01

S5

-1.8067E-01

-8.8801E+00

6.0162E+01

-2.0273E+02

4.3860E+02

-6.2674E+02

5.6613E+02

-2.8880E+02

6.1951E+01

S6

-2.7409E-01

3.5213E-01

-2.9714E+00

2.2958E+01

-7.2217E+01

1.2030E+02

-1.1394E+02

5.8380E+01

-1.2590E+01

S7

-8.7092E-01

2.1008E+00

-4.1429E+00

6.0742E+00

-6.5164E+00

4.8635E+00

-2.3588E+00

6.6212E-01

-8.0971E-02

S8

-1.7222E-01

2.2546E-01

-3.9617E-01

3.4509E-01

-1.4875E-01

2.8065E-02

3.8589E-04

-9.1151E-04

9.3855E-05

S9

-5.0465E-02

1.6581E-01

-5.2628E-01

5.7580E-01

-3.3163E-01

1.1332E-01

-2.3211E-02

2.6427E-03

-1.2896E-04

S10

2.6481E-01

-1.5361E-01

-7.2555E-02

1.4605E-01

-9.3637E-02

3.3204E-02

-6.8979E-03

7.8719E-04

-3.8162E-05

Table 10

Fig. 10A shows an on-axis chromatic aberration curve of the optical imaging lens group of embodiment 5, which indicates a convergent focus deviation after light rays of different wavelengths pass through the lens. Fig. 10B shows an astigmatism curve of the optical imaging lens group of embodiment 5, which represents meridional image plane curvature and sagittal image plane curvature. Fig. 10C shows a distortion curve of the optical imaging lens group of embodiment 5, which represents distortion magnitude values corresponding to different angles of view. Fig. 10D shows a magnification chromatic aberration curve of the optical imaging lens group of embodiment 5, which represents the deviation of different image heights on the imaging plane after light passes through the lens. As can be seen from fig. 10A to 10D, the optical imaging lens group provided in embodiment 5 can achieve good imaging quality.

Example 6

An optical imaging lens group according to embodiment 6 of the present application is described below with reference to fig. 11 to 12D. Fig. 11 shows a schematic configuration diagram of an optical imaging lens group according to embodiment 6 of the present application.

As shown in fig. 11, the optical imaging lens assembly sequentially includes, from an object side to an image side: an aperture stop STO, a first lens E1, a field stop ST, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, an optical filter E6, and an imaging surface S13.

The first lens element E1 has positive refractive power, wherein an object-side surface S1 thereof is convex, and an image-side surface S2 thereof is convex. The second lens element E2 has positive refractive power, wherein an object-side surface S3 thereof is convex, and an image-side surface S4 thereof is convex. The third lens element E3 has negative refractive power, wherein an object-side surface S5 thereof is concave and an image-side surface S6 thereof is convex. The fourth lens element E4 has negative refractive power, wherein an object-side surface S7 thereof is convex and an image-side surface S8 thereof is concave. The fifth lens element E5 has positive refractive power, wherein an object-side surface S9 thereof is convex, and an image-side surface S10 thereof is concave. The filter E6 has an object side surface S11 and an image side surface S12. 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 imaging lens group is 2.03mm, the total length TTL of the optical imaging lens group is 3.61mm, the half of the diagonal length ImgH of the effective pixel region on the imaging surface S13 of the optical imaging lens group is 2.40mm, the maximum half field angle Semi-FOV of the optical imaging lens group is 55.5 °, and the aperture value Fno is 2.20.

Table 11 shows a basic parameter table of the optical imaging lens group of embodiment 6, in which the units of radius of curvature, thickness/distance, and focal length are all millimeters (mm). Table 12 shows the higher order coefficients that can be used for each of the aspherical mirror surfaces in example 6, wherein each of the aspherical surface types can be defined by the formula (1) given in example 1 above.

TABLE 11

Face number

A4

A6

A8

A10

A12

A14

A16

A18

A20

S1

-7.3250E-02

-2.8336E+00

7.0323E+01

-1.2694E+03

1.4681E+04

-1.0591E+05

4.5706E+05

-1.0760E+06

1.0607E+06

S2

-1.5122E-01

-1.2191E+01

2.1432E+02

-2.2757E+03

1.4788E+04

-5.9815E+04

1.4705E+05

-2.0119E+05

1.1753E+05

S3

-5.3983E-01

1.8204E+00

-2.6316E+01

1.3561E+02

-3.1857E+02

-2.8670E+02

3.1522E+03

-5.8801E+03

3.4998E+03

S4

-7.5409E-01

-9.5779E-01

9.3384E+00

-3.8985E+01

7.8354E+01

-4.7384E+01

-7.8704E+01

1.4784E+02

-7.2385E+01

S5

-7.7777E-02

-6.8122E+00

5.2126E+01

-2.1920E+02

5.7617E+02

-9.4463E+02

9.3755E+02

-5.1581E+02

1.2070E+02

S6

-1.8191E-01

-5.1525E-01

3.4183E+00

-6.8281E+00

5.6408E+00

9.4000E-01

-5.8754E+00

4.4807E+00

-1.1402E+00

S7

-3.6313E-01

5.0724E-01

-8.8750E-01

1.2252E+00

-1.2481E+00

8.3757E-01

-3.5020E-01

8.2676E-02

-8.3246E-03

S8

-1.1359E-01

-8.5501E-02

2.5251E-01

-3.4343E-01

2.5866E-01

-1.1152E-01

2.7454E-02

-3.5783E-03

1.9021E-04

S9

-1.0406E-02

-1.0040E-01

-1.3581E-01

2.5997E-01

-1.6925E-01

5.8979E-02

-1.1751E-02

1.2616E-03

-5.6533E-05

S10

3.7206E-01

-7.6544E-01

7.3863E-01

-4.4124E-01

1.7276E-01

-4.4514E-02

7.2531E-03

-6.7455E-04

2.7162E-05

Table 12

Fig. 12A shows an on-axis chromatic aberration curve of the optical imaging lens group of embodiment 6, which indicates a convergent focus deviation after light rays of different wavelengths pass through the lens. Fig. 12B shows an astigmatism curve of the optical imaging lens group of embodiment 6, which represents meridional image plane curvature and sagittal image plane curvature. Fig. 12C shows a distortion curve of the optical imaging lens group of embodiment 6, which represents distortion magnitude values corresponding to different angles of view. Fig. 12D shows a magnification chromatic aberration curve of the optical imaging lens group of embodiment 6, which represents the deviation of different image heights on the imaging plane after light passes through the lens. As can be seen from fig. 12A to 12D, the optical imaging lens group provided in embodiment 6 can achieve good imaging quality.

In summary, examples 1 to 6 satisfy the relationships shown in table 13, respectively.

Condition/example	1	2	3	4	5	6
							TTL/f×ImgH(mm)	4.54	4.47	4.11	3.65	4.20	4.27
Semi-FOV(°)	61.3	58.9	53.6	53.3	55.4	55.5
							f5/f	0.85	2.01	1.16	0.94	1.24	0.86
f/R9	2.80	2.73	1.58	2.85	1.47	3.47
							(R4+R5)/(R4-R5)	2.74	2.81	2.03	3.12	2.05	2.21
CT4/T45	8.65	4.81	4.98	6.31	4.19	10.01
							(SAG31+SAG32)/(SAG31-SAG32)	14.95	19.52	30.14	12.29	24.42	21.11
CT2/T23	3.95	3.78	2.80	5.54	2.89	3.69
							∑AT/TD	0.13	0.14	0.19	0.12	0.19	0.16
100×T34/TmgH	1.25	1.36	1.25	2.56	1.25	1.25

TABLE 13

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

The above description is only illustrative of the preferred embodiments of the present application and of the principles of the technology employed. It will be appreciated by persons skilled in the art that the scope of the application referred to in the present application is not limited to the specific combinations of the technical features described above, but also covers other technical features formed by any combination of the technical features described above or their equivalents without departing from the inventive concept. Such as the above-mentioned features and the technical features disclosed in the present application (but not limited to) having similar functions are replaced with each other.

Claims (8)

1. The optical imaging lens assembly includes, in order from an object side to an image side along an optical axis:

A diaphragm;

A first lens having optical power;

A second lens having positive optical power, the image side surface of which is convex;

The third lens with negative focal power has a concave object side surface and a convex image side surface;

A fourth lens element with positive refractive power having a convex object-side surface and a concave image-side surface, wherein at least one of the object-side surface and the image-side surface of the fourth lens element has an inflection point;

A fifth lens with positive focal power, wherein an object side surface of the fifth lens is a convex surface, and an image side surface of the fifth lens is provided with an inflection point;

wherein the number of lenses of the optical imaging lens group with optical power is five;

The distance TTL from the object side surface of the first lens element to the imaging surface of the optical imaging lens assembly on the optical axis, the total effective focal length f of the optical imaging lens assembly, and half of the diagonal length ImgH of the effective pixel area on the imaging surface satisfy: 3.50 mm < ImgH/fTTL < 5.00 mm;

The radius of curvature R4 of the image side surface of the second lens and the radius of curvature R5 of the object side surface of the third lens satisfy: (R4+R5)/(R4-R5) is less than or equal to 2.74 and less than 3.50;

The center thickness CT2 of the second lens on the optical axis and the separation distance T23 of the second lens and the third lens on the optical axis satisfy: CT2/T23 is less than or equal to 3.78 and less than 6.00.

2. The optical imaging lens group according to claim 1, wherein a maximum half field angle Semi-FOV of the optical imaging lens group satisfies: the Semi-FOV is less than 53.0 degrees and less than or equal to 61.3 degrees.

3. The optical imaging lens group according to claim 1, wherein a total effective focal length f of the optical imaging lens group and an effective focal length f5 of the fifth lens satisfy: 0.50 < f5/f < 2.50.

4. The optical imaging lens group according to claim 1, wherein a total effective focal length f of the optical imaging lens group and a radius of curvature R9 of an object side surface of the fifth lens satisfy: 1.00 < f/R9 < 3.50.

5. The optical imaging lens group according to claim 1, wherein a center thickness CT4 of the fourth lens on the optical axis and a separation distance T45 of the fourth lens and the fifth lens on the optical axis satisfy: CT4/T45 is more than 4.00 and less than 10.50.

6. The optical imaging lens group according to claim 1, wherein an on-axis distance SAG31 from an intersection of the object side surface of the third lens and the optical axis to an effective radius vertex of the object side surface of the third lens and an on-axis distance SAG32 from an intersection of the image side surface of the third lens and the optical axis to an effective radius vertex of the image side surface of the third lens satisfy: 12.00 < (SAG31+SAG32)/(SAG 31-SAG 32) < 30.50.

7. The optical imaging lens group according to claim 1, wherein a distance T34 between the third lens and the fourth lens on the optical axis and a half of a diagonal length of an effective pixel area on the imaging surface ImgH satisfies: 1.00 < 100 xT 34/ImgH < 3.00.

8. The optical imaging lens group according to any one of claims 1 to 7, wherein a sum Σat of a distance TD on the optical axis from an object side surface of the first lens to an image side surface of the fifth lens and a distance separating any adjacent two of the first lens to the fifth lens on the optical axis satisfies: sigma AT/TD is more than or equal to 0.12 and less than 0.20.