CN115032772B - Large aperture optical lens - Google Patents

Abstract

The invention relates to the technical field of optical lenses, in particular to a large-aperture optical lens. Which comprises, in order from an object side to an image side along an optical axis: a first lens with positive focal power, the object side surface of which is a convex surface; a second lens with positive focal power, the object side surface of which is concave at the paraxial region; a third lens having negative optical power, the image-side paraxial region of which is concave; a fourth lens with negative focal power, wherein the object side surface of the fourth lens is a convex surface or a concave surface at the paraxial region; the object side paraxial region and the image side paraxial region of the fifth lens with positive focal power are convex; a sixth lens with negative focal power, wherein the object side surface of the sixth lens is a convex surface at the paraxial region; the optical lens further comprises a diaphragm positioned in front of the second lens; the aperture size of the optical lens is FNO <1.45. The optical lens has the advantages of larger aperture, high quality analysis force, good optical performance and the like by reasonably distributing the focal power, the surface type, the center thickness and the axial spacing between the lenses.

Description

Large aperture optical lens

Technical Field

The invention relates to the technical field of optical lenses, in particular to a large-aperture optical lens.

Background

Along with the continuous development and progress of intelligent products, the imaging quality requirements of people on electronic equipment are higher and higher, one action point of the high imaging quality is the size of the light flux, the light flux is large, the light in a larger range can be controlled to enter the lens, and meanwhile, the large aperture can also enable the depth of field of the lens to be wider, so that a photographed object is clearer. The existing optical lens has the following defects:

1. The light quantity is smaller, the FNO is larger, the characteristics of a large aperture can not be met, the light transmission range is limited, and the night scene shooting is not facilitated.

2. The depth of field is short and the imaging quality is poor.

Disclosure of Invention

In view of the above-mentioned drawbacks and shortcomings of the prior art, the present invention provides a large aperture optical lens, which solves the problems of small light flux, short depth of field and low resolving power in the prior art.

In order to achieve the above purpose, the main technical scheme adopted by the invention comprises the following steps:

The embodiment of the invention provides a large aperture optical lens, which sequentially comprises the following components from an object side to an image side: a first lens with positive focal power, the object side surface of which is a convex surface; a second lens with positive focal power, the object side surface of which is concave at the paraxial region; a third lens having negative optical power, the image-side paraxial region of which is concave; a fourth lens with negative focal power, wherein the object side surface of the fourth lens is a convex surface or a concave surface at the paraxial region; the object side paraxial region and the image side paraxial region of the fifth lens with positive focal power are convex; a sixth lens with negative focal power, wherein the object side surface of the sixth lens is a convex surface at the paraxial region; the optical lens further comprises a diaphragm, and the position of the diaphragm is positioned in front of the second lens; the aperture size of the optical lens is FNO <1.45.

Further, the optical lens satisfies the following relation: F4/|F3| <1 >, wherein F3 is the focal length of the third lens and F4 is the focal length of the fourth lens.

Further, the optical lens satisfies the following relation: T56/T34>0.6, wherein T34 is the distance between the third lens and the fourth lens on the optical axis, and T56 is the distance between the fifth lens and the sixth lens on the optical axis.

Further, the optical lens satisfies the following relation: and ΣAT/T34>4.5, wherein ΣAT is the sum of the interval distances of every two adjacent lenses in the optical lens on the optical axis, and T34 is the distance between the third lens and the fourth lens on the optical axis.

Further, the optical lens satisfies the following relation: (|Sag51|+|Sag52|)/CT 5>1, wherein Sag51 is the sagittal height of the fifth lens at the maximum effective half-caliber of the object side, sag52 is the sagittal height of the fifth lens at the maximum effective half-caliber of the image side, and CT5 is the thickness of the fifth lens.

The beneficial effects of the invention are as follows: the large-aperture optical lens provided by the invention adopts a plurality of lenses, such as 6 lenses, and adopts an aspheric plastic lens combination mode, so that the optical lens has the advantages of large aperture, high quality analysis force, good optical performance and the like.

Drawings

Fig. 1 is a schematic diagram of a large aperture optical lens according to embodiment 1 of the present invention;

FIG. 2A is a graph of the on-axis chromatic aberration of example 1 of the present invention;

FIG. 2B is an astigmatic curve diagram of example 1 of the present invention;

FIG. 2C is a graph of distortion for example 1 of the present invention;

FIG. 2D is a graph of the chromatic aberration of magnification of embodiment 1 of the present invention;

Fig. 3 is a schematic diagram of a large aperture optical lens according to embodiment 2 of the present invention;

FIG. 4A is a graph of the color difference on the axis of example 2 of the present invention;

FIG. 4B is an astigmatic curve chart of embodiment 2 of the present invention;

FIG. 4C is a graph of distortion for example 2 of the present invention;

FIG. 4D is a graph of the chromatic aberration of magnification of embodiment 2 of the present invention;

fig. 5 is a schematic diagram of the structure of a large aperture optical lens according to embodiment 3 of the present invention;

FIG. 6A is a graph of the color difference on the axis of example 3 of the present invention;

FIG. 6B is an astigmatic curve diagram of example 3 of the present invention;

FIG. 6C is a graph of distortion for example 3 of the present invention;

Fig. 6D is a graph of the chromatic aberration of magnification in example 3 of the present invention.

In the figure: the first lens E1, the second lens E2, the third lens E3, the fourth lens E4, the fifth lens E5, the sixth lens E6, the optical filter E7, and the stop ST.

Detailed Description

The invention will be better explained by the following detailed description of the embodiments with reference to the drawings.

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 invention.

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 and the surface of each lens closest to the imaging plane is referred to as the image side.

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

A large aperture optical lens comprising: a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5 and a sixth lens E6. The six lenses are sequentially arranged from the object side to the image side along the optical axis.

The first lens E1 is an aspheric plastic lens with positive focal power, and an object side surface thereof is a convex surface.

The second lens E2 is an aspheric plastic lens with positive focal power, and the object side surface of the second lens E is a concave surface at the paraxial position.

The third lens E3 is an aspheric plastic lens with negative focal power, and the image side surface of the third lens E is concave at the paraxial region.

The fourth lens E4 is an aspheric plastic lens with negative focal power, and the paraxial region of the object side surface of the fourth lens E can be a convex surface or a concave surface.

The fifth lens element E5 is an aspheric plastic lens with positive refractive power, and has convex surfaces at the paraxial region of the object side and the paraxial region of the image side.

The sixth lens E6 is an aspheric plastic lens with negative focal power, and the paraxial portion of the object side surface of the sixth lens E is a convex surface.

The optical lens further comprises a diaphragm ST, and the diaphragm ST is positioned in front of the second lens E2. The optical lens satisfies a conditional expression FNO <1.45, wherein FNO is the aperture size of the optical lens. Limiting the aperture size and position can improve resolution while meeting large apertures.

The optical lens meets the condition formula F4/|F3| < 1, wherein F3 is the focal length of the third lens, and F4 is the focal length of the fourth lens. The reasonable distribution of focal length can make chromatic aberration of the optical imaging lens and improve distortion.

The optical lens meets the condition that T56/T34 is more than 0.6, wherein T34 is the distance between the third lens and the fourth lens on the optical axis, and T56 is the distance between the fifth lens and the sixth lens on the optical axis. The lens interval can be reasonably controlled to properly improve the stray light of the lens, and the lens has a compensation effect on the structural appearance

The optical lens satisfies a condition that Σat/T34>4.5, wherein Σat is the sum of the interval distances of every two adjacent lenses in the lens on the optical axis, and T34 is the distance between the third lens and the fourth lens on the optical axis. The overall height of the lens can be reasonably controlled to meet the miniaturization of the lens and the overall layout of the lens is more reasonable, and the requirement of production on the thickness of the lens is fundamentally met by compensating the later-stage structure.

The optical lens meets the condition (|Sag51|+|Sag52|)/CT 5>1, wherein Sag51 is the sagittal height of the fifth lens at the maximum effective half-caliber of the object side, sag52 is the sagittal height of the fifth lens at the maximum effective half-caliber of the image side, and CT5 is the thickness of the fifth lens. Sag is actually the sagittal height of the lens, the proper sagittal height to intermediate thickness ratio can lead to uniform lens shape, and the management of the sagittal height of the lens can improve sensitivity and is beneficial to processing and molding.

The optical lens described above may further include a filter for correcting color deviation and/or a protective glass for protecting a photosensitive element located on an imaging surface as needed in the specific case of the embodiment, and the filter or the protective glass may not be used without specific requirement.

The optical lens of the above embodiment may employ a plurality of lenses, for example, six 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, the volume of the lens can be effectively reduced, the sensitivity of the lens can be reduced, and the processability of the lens can be improved, so that the optical lens is more beneficial to production and processing. Meanwhile, the optical lens with the configuration has the beneficial effects of ultra-thin, ultra-wide angle, high imaging quality and the like.

In an embodiment of the present invention, the mirror surface of the partial lens is an aspherical mirror surface. The aspherical lens is characterized in that: the curvature varies continuously from the center of the lens to the periphery of the lens. Unlike a spherical lens having a constant curvature from the center of the lens to the periphery of the lens, an aspherical lens has a better radius of curvature characteristic, and has advantages of improving distortion aberration and improving astigmatic aberration. By adopting the aspherical lens, aberration occurring at the time of imaging can be eliminated as much as possible, thereby improving imaging quality.

Example 1

An optical lens according to embodiment 1 of the present invention is described below with reference to fig. 1, 2A to 2D. Fig. 1 shows a schematic configuration of an optical lens according to embodiment 1 of the present invention.

As shown in fig. 1, an optical lens according to an exemplary embodiment of the present invention sequentially includes, along an optical axis from an object side to an image side: a first lens E1, a diaphragm ST, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a sixth lens E6, and an optical filter E7.

The first lens element E1 is an aspheric plastic lens element with positive refractive power, wherein the object-side surface S1 thereof is a convex surface, and the image-side surface S2 thereof is a concave surface. The second lens element E2 has a positive refractive power and an object-side surface S4 which is concave and an image-side surface S5 which is convex. The third lens element E3 is an aspheric plastic lens element with negative refractive power, and has a convex object-side surface S6 and a concave image-side surface S7. The fourth lens element E4 has an aspheric plastic lens element with negative refractive power, and has a convex object-side surface S8 and a concave image-side surface S9. The fifth lens element E5 is an aspheric plastic lens element with positive refractive power, and has a convex object-side surface S10 and a convex image-side surface S11. The sixth lens element E6 is an aspheric plastic lens element with positive power, and has a convex object-side surface S12 and a concave image-side surface S13. The filter E7 has an object side surface S14 and an image side surface S15. Light from the object sequentially passes through the respective surfaces S1 to S15, and is finally imaged on the imaging surface S16.

Table 1 shows the surface types, radii of curvature, thicknesses, materials, and cone coefficients of the respective lenses of the optical lens of example 1, wherein the radii of curvature and thicknesses are each in millimeters (mm).

TABLE 1

In table 1, the object side surface and the image side surface of any one of the first lens E1 to the sixth lens E6 are aspheric. In this embodiment, the surface shape 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 the conic coefficient (given in table 1); ai is the correction coefficient of the i-th order of the aspherical surface. The higher order coefficients A4, A6, A8, A10, A12, A14 that can be used for each of the aspherical mirrors S1-S13 in example 1 are given in Table 2 below.

TABLE 2

Table 3 gives the total effective focal length f of the optical lens in embodiment 1, the effective focal lengths f1 to f6 of the respective lenses, the total optical length TTL of the optical lens (i.e., the distance on the optical axis from the center of the object side surface S1 of the first lens E1 to the imaging surface S16), and the maximum field angle FOV of the optical lens.

TABLE 3 Table 3

The optical lens in embodiment 1 satisfies:

The aperture size FNO of this embodiment is 1.44, and the diaphragm is located between the first lens and the second lens, satisfying FNO <1.45, the diaphragm being located before the second lens.

F4/|f3|= -2.586 in this embodiment satisfies f4/|f3| < 1. Wherein F3 is the focal length of the third lens of the optical lens, and F4 is the focal length of the fourth lens of the optical lens.

In this embodiment, T56/t34= 0.8422, where T34 is the distance between the third lens and the fourth lens on the optical axis, and T56 is the distance between the fifth lens and the sixth lens on the optical axis, which satisfies T56/T34> 0.6.

In this embodiment, Σat/t34=5.32, and Σat/t34>4.5 is satisfied, where Σat is the sum of the distances between each two adjacent lenses in the lens on the optical axis, and T34 is the distance between the third lens and the fourth lens on the optical axis.

In this embodiment (|Sag51|+|Sag52|)/Ct5=1.08, satisfying (|Sag51|+|Sag52|)/Ct5 >1, where Sag51 is the sagittal height of the fifth lens at the maximum effective half-caliber of the object-side surface, and Sag52 is the sagittal height of the fifth lens at the maximum effective half-caliber of the image-side surface; CT5 is the thickness of the fifth lens.

In addition, fig. 2A shows an on-axis chromatic aberration curve of the optical lens of embodiment 1, which represents the deviation of the converging focus after light rays of different wavelengths pass through the lens. Fig. 2B shows an astigmatism curve of the optical lens of embodiment 1, which represents meridional image plane curvature and sagittal image plane curvature. Fig. 2C shows a distortion curve of the optical lens of embodiment 1, which represents distortion magnitude values in different image heights. Fig. 2D shows a chromatic aberration of magnification curve of the optical lens 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 lens provided in embodiment 1 can achieve good imaging quality.

Example 2

An optical lens according to embodiment 2 of the present invention is described below with reference to fig. 3, 4A 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 structural view of an optical lens according to embodiment 2 of the present invention.

As shown in fig. 3, an optical lens according to an exemplary embodiment of the present invention sequentially includes, along an optical axis from an object side to an image side: diaphragm ST, first lens E1, second lens E2, third lens E3, fourth lens E4, fifth lens E5, sixth lens E6, and filter E7.

The first lens element E1 is an aspheric plastic lens element with positive refractive power, wherein the object-side surface S2 thereof is a convex surface, and the image-side surface S3 thereof is a concave surface. The second lens element E2 has a positive refractive power and an object-side surface S4 which is concave and an image-side surface S5 which is convex. The third lens element E3 is an aspheric plastic lens element with negative refractive power, and has a convex object-side surface S6 and a concave image-side surface S7. The fourth lens element E4 has a concave object-side surface S8 and a concave image-side surface S9. The fifth lens element E5 is an aspheric plastic lens element with positive refractive power, and has a convex object-side surface S10 and a convex image-side surface S11. The sixth lens element E6 is an aspheric plastic lens element with negative refractive power, and has a convex object-side surface S12 and a concave image-side surface S13. The filter E7 has an object side surface S14 and an image side surface S15. Light from the object sequentially passes through the respective surfaces S1 to S15, and is finally imaged on the imaging surface S16.

Table 4 shows the surface types, radii of curvature, thicknesses, materials, and cone coefficients of the respective lenses of the optical lens of example 2, wherein the radii of curvature and thicknesses are each in millimeters (mm).

TABLE 4 Table 4

As can be seen from table 4, in example 2, the object side surface and the image side surface of any one of the first lens E1 to the sixth lens E6 are aspherical surfaces. Table 5 shows the higher order coefficients A4, A6, A8, A10, A12, A14, A16 that can be used for each of the aspherical mirror surfaces S1-S13 in example 2, where each of the aspherical surface types can be defined by equation (1) given in example 1 above.

TABLE 5

Face number

A4

A6

A8

A10

A12

A14

A16

S1

-1.48E-02

-4.76E-02

3.22E-02

-4.15E-02

-1.18E-02

3.06E-02

-9.50E-03

S2

-1.42E-01

-5.29E-03

-9.35E-02

2.32E-01

-2.06E-01

8.36E-02

-1.34E-02

S4

-5.83E-02

7.23E-03

-5.88E-03

1.35E-01

-1.32E-01

4.76E-02

-5.93E-03

S5

-9.18E-02

2.28E-01

-4.13E-01

5.10E-01

-3.83E-01

1.56E-01

-2.64E-02

S6

-5.78E-02

5.14E-02

-2.59E-01

3.01E-01

-1.83E-01

6.64E-02

-1.15E-02

S7

-3.92E-02

1.04E-01

-2.32E-01

2.34E-01

-1.25E-01

3.56E-02

-4.55E-03

S8

-9.50E-02

1.14E-01

-1.66E-03

-3.97E-02

1.47E-02

5.47E-04

-8.16E-04

S9

-1.27E-01

-2.47E-02

1.47E-01

-1.68E-01

1.09E-01

-3.89E-02

5.84E-03

S10

5.77E-02

-1.87E-01

2.52E-01

-2.32E-01

1.26E-01

-3.64E-02

4.21E-03

S11

1.60E-02

-6.45E-03

3.71E-04

-1.13E-02

9.04E-03

-2.36E-03

2.00E-04

S12

-1.15E-01

-4.29E-02

7.65E-02

-4.60E-02

1.54E-02

-2.68E-03

1.86E-04

S13

-1.02E-01

4.80E-02

-1.61E-02

3.49E-03

-4.68E-04

3.52E-05

-1.13E-06

Table 6 shows the total effective focal length f of the optical lens, the effective focal lengths f1 to f6 of the respective lenses, the total optical length TTL of the optical lens, and the maximum field angle FOV of the optical lens in embodiment 2.

TABLE 6

The optical lens in embodiment 2 satisfies:

The aperture size FNO of this embodiment is 1.44, and the aperture position is in front of the first lens, satisfying FNO <1.45, the aperture is in front of the second lens.

In this embodiment, f4/|f3|= -2.097, and f4/|f3| < 1 is satisfied. Wherein F3 is the focal length of the third lens of the optical lens, and F4 is the focal length of the fourth lens of the optical lens.

In this embodiment, T56/t34= 0.724, where T34 is the distance between the third lens and the fourth lens on the optical axis, and T56 is the distance between the fifth lens and the sixth lens on the optical axis, which satisfies T56/T34> 0.6.

In this embodiment, Σat/t34=4.948 satisfies Σat/t34>4.5, where Σat is the sum of the distances between each two adjacent lenses in the lens on the optical axis, and T34 is the distance between the third lens and the fourth lens on the optical axis.

In this embodiment (|Sag51|+|Sag52|)/CT5=1.167, satisfying (|Sag51|+|Sag52|)/CT 5>1, where Sag51 is the sagittal height of the fifth lens at the maximum effective half-caliber of the object-side surface, and Sag52 is the sagittal height of the fifth lens at the maximum effective half-caliber of the image-side surface; CT5 is the thickness of the fifth lens.

Fig. 4A shows an on-axis chromatic aberration curve of the optical lens of embodiment 2, which indicates the deviation of the converging focus after light rays of different wavelengths pass through the lens. Fig. 4B shows an astigmatism curve of the optical lens of embodiment 2, which represents meridional image plane curvature and sagittal image plane curvature. Fig. 4C shows a distortion curve of the optical lens of embodiment 2, which represents distortion magnitude values in different image heights. Fig. 4D shows a magnification chromatic aberration curve of the optical lens 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 lens provided in embodiment 2 can achieve good imaging quality.

Example 3

An optical lens according to embodiment 3 of the present invention is described below with reference to fig. 5, 6A to 6D. In this embodiment and the following embodiments, descriptions of portions similar to embodiment 1 will be omitted for brevity. Fig. 5 shows a schematic structural view of an optical lens according to embodiment 3 of the present invention.

As shown in fig. 5, an optical lens according to an exemplary embodiment of the present invention sequentially includes, along an optical axis from an object side to an image side: diaphragm ST, first lens E1, second lens E2, third lens E3, fourth lens E4, fifth lens E5, sixth lens E6, and filter E7.

The first lens element E1 is an aspheric plastic lens element with positive refractive power, wherein the object-side surface S2 thereof is a convex surface, and the image-side surface S3 thereof is a concave surface. The second lens element E2 has a positive refractive power and an object-side surface S4 which is concave and an image-side surface S5 which is convex. The third lens element E3 is an aspheric plastic lens element with negative refractive power, and has a convex object-side surface S6 and a concave image-side surface S7. The fourth lens element E4 has a concave object-side surface S8 and a concave image-side surface S9. The fifth lens element E5 is an aspheric plastic lens element with positive refractive power, and has a convex object-side surface S10 and a convex image-side surface S11. The sixth lens element E6 is an aspheric plastic lens element with negative refractive power, and has a convex object-side surface S12 and a concave image-side surface S13. The filter E7 has an object side surface S14 and an image side surface S15. Light from the object sequentially passes through the respective surfaces S1 to S15, and is finally imaged on the imaging surface S16.

Table 7 shows the surface types, radii of curvature, thicknesses, materials, and cone coefficients of the respective lenses of the optical lens of example 3, wherein the radii of curvature and thicknesses are each in millimeters (mm).

TABLE 7

As can be seen from table 7, in example 3, the object side surface and the image side surface of any one of the first lens E1 to the sixth lens E6 are aspherical surfaces. Table 8 shows the higher order coefficients A4, A6, A8, A10, A12, A14, A16 that can be used for each of the aspherical mirror surfaces S1-S13 in example 3, where each of the aspherical surface types can be defined by the formula (1) given in example 1 above.

TABLE 8

Face number

A4

A6

A8

A10

A12

A14

A16

S1

-1.77E-02

-4.66E-02

3.34E-02

-5.39E-02

2.85E-02

-2.50E-03

-1.13E-03

S2

-1.27E-01

-1.61E-02

-3.54E-02

1.28E-01

-1.22E-01

5.11E-02

-8.31E-03

S4

-4.07E-02

-4.86E-03

1.14E-02

1.02E-01

-1.19E-01

5.09E-02

-8.04E-03

S5

-7.43E-02

1.23E-01

-1.60E-01

1.83E-01

-1.38E-01

5.65E-02

-9.39E-03

S6

-3.05E-02

-7.89E-02

4.39E-02

-4.95E-02

4.36E-02

-1.51E-02

1.50E-03

S7

-4.41E-02

7.63E-02

-1.52E-01

1.44E-01

-7.36E-02

2.00E-02

-2.44E-03

S8

-7.32E-02

1.02E-01

-2.02E-02

-1.28E-02

2.82E-03

2.18E-03

-7.21E-04

S9

-1.31E-01

3.20E-02

3.27E-02

-4.89E-02

3.35E-02

-1.19E-02

1.73E-03

S10

3.60E-02

-1.08E-01

1.25E-01

-1.02E-01

4.94E-02

-1.27E-02

1.30E-03

S11

7.26E-03

-8.13E-03

1.55E-02

-2.29E-02

1.31E-02

-3.14E-03

2.69E-04

S12

-1.09E-01

-2.73E-02

5.35E-02

-3.14E-02

1.03E-02

-1.74E-03

1.17E-04

S13

-9.77E-02

4.56E-02

-1.51E-02

3.23E-03

-4.25E-04

3.11E-05

-9.62E-07

Table 8 shows the total effective focal length f of the optical lens, the effective focal lengths f1 to f6 of the respective lenses, the total optical length TTL of the optical lens, and the maximum field angle FOV of the optical lens in embodiment 3.

TABLE 9

The optical lens in embodiment 3 satisfies:

The aperture size FNO of this embodiment is 1.43, and the aperture position is in front of the first lens, satisfying FNO <1.45, the aperture is in front of the second lens.

F4/|f3|= -1.952 in this embodiment satisfies f4/|f3| <1. Wherein F3 is the focal length of the third lens and F4 is the focal length of the fourth lens.

In this embodiment, T56/t34= 0.6697, where T34 is the distance between the third lens and the fourth lens on the optical axis, and T56 is the distance between the fifth lens and the sixth lens on the optical axis, which satisfies T56/T34> 0.6.

In this embodiment, Σat/t34=5.06, where Σat is the sum of the distances between every two adjacent lenses in the lens on the optical axis, and T34 is the distance between the third lens and the fourth lens on the optical axis, and Σat/T34>4.5 is satisfied.

In this embodiment (|Sag51|+|Sag52|)/CT5=1.06, satisfying (|Sag51|+|Sag52|)/CT 5>1, where Sag51 is the sagittal height of the fifth lens at the maximum effective half-caliber of the object-side surface, and Sag52 is the sagittal height of the fifth lens at the maximum effective half-caliber of the image-side surface; CT5 is the thickness of the fifth lens.

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

While embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and not to be construed as limiting the invention, and that alterations, modifications, substitutions and variations may be made in the above embodiments by those skilled in the art within the scope of the invention.

Claims (3)

1. The utility model provides a big light ring optical lens, its characterized in that includes in proper order from the thing side to the image side:

a first lens with positive focal power, the object side surface of which is a convex surface;

a second lens with positive focal power, the object side surface of which is concave at the paraxial region;

a third lens having negative optical power, the image-side paraxial region of which is concave;

a fourth lens with negative focal power, wherein the object side surface of the fourth lens is a convex surface or a concave surface at the paraxial region;

the object side paraxial region and the image side paraxial region of the fifth lens with positive focal power are convex;

A sixth lens with negative focal power, wherein the object side surface of the sixth lens is a convex surface at the paraxial region;

The optical lens further comprises a diaphragm, and the position of the diaphragm is positioned in front of the second lens;

the aperture size of the optical lens is FNO <1.45;

the optical lens satisfies the following relation:

F4/|F3|<-1

5.32≥ΣAT/T34>4.5

wherein F3 is the focal length of the third lens, F4 is the focal length of the fourth lens, Σat is the sum of the distances between every two adjacent lenses in the optical lens on the optical axis, and T34 is the distance between the third lens and the fourth lens on the optical axis.

2. The large aperture optical lens of claim 1, wherein the optical lens satisfies the following relationship:

0.8422≥T56/T34>0.6

Wherein T34 is the distance between the third lens and the fourth lens on the optical axis, and T56 is the distance between the fifth lens and the sixth lens on the optical axis.

3. The large aperture optical lens of claim 1, wherein the optical lens satisfies the following relationship:

1.167≥(|Sag51|+|Sag52|)/CT5>1

Wherein Sag51 is the sagittal height of the fifth lens element at the maximum effective half-caliber of the object side, sag52 is the sagittal height of the fifth lens element at the maximum effective half-caliber of the image side, and CT5 is the thickness of the fifth lens element.