CN112230392A

CN112230392A - Wide-angle high-resolution lens

Info

Publication number: CN112230392A
Application number: CN202011282223.3A
Authority: CN
Inventors: 王春燕; 金兑映
Original assignee: Liaoning Zhonglan Photoelectric Technology Co Ltd
Current assignee: Liaoning Zhonglan Photoelectric Technology Co Ltd
Priority date: 2020-11-16
Filing date: 2020-11-16
Publication date: 2021-01-15
Anticipated expiration: 2040-11-16
Also published as: CN112230392B

Abstract

A wide-angle high-resolution lens of the present invention includes five lenses arranged in sequence from the object side to the image surface along the optical axis, the first lens has negative refractive power, and its image side surface is concave; the second lens has positive light power, the object-side surface is convex, and at least one surface is aspheric; the third lens has negative refractive power, and its image-side surface is concave; the image-side surface of the fourth lens is convex, and at least one surface is aspheric; The fifth lens has negative refractive power, its image-side surface is concave, and at least one surface is aspherical; and the following conditional formula is satisfied: TTL/EFL>2, TTL is the difference between the object-side surface and the imaging surface of the first lens. Axial distance, EFL is the focal length of the lens; TTL/FBL<6.7FBL is the distance from the maximum effective radius position of the lens on the image side surface of the fifth lens to the imaging surface; CT S8/TD<0.17TD is the object side surface of the first lens to The axial distance of the image-side surface of the fifth lens, CT S8 is the center thickness of the fourth lens.

Description

Wide-angle high-resolution lens

Technical Field

The invention belongs to the technical field of optical lenses, and relates to a wide-angle high-resolution lens.

Background

With the continuous development of portable electronic products such as smart phones, wide visual field is increasingly required for lens shooting. This requires the use of a wide-angle lens, which has a shorter focal length than a standard lens, but a wide viewing angle. With the development of technology, a lens is required to satisfy a miniaturization requirement while having a wide-angle characteristic.

Disclosure of Invention

The invention provides a wide-angle high-resolution lens which can simultaneously meet wide-angle requirements and miniaturization requirements, and is suitable for mobile phones and other portable electronic products.

The invention discloses a wide-angle high-resolution lens, which comprises a first lens, a second lens, a third lens, a fourth lens and a fifth lens which are sequentially arranged from an object side to an image surface along an optical axis, wherein the first lens has negative focal power, and the surface of the image side of the first lens is a concave surface; the second lens has positive focal power, the object side surface of the second lens is a convex surface, and at least one surface of the second lens is an aspheric surface; the third lens has negative focal power, and the surface of the image side of the third lens is a concave surface; the surface of the image side of the fourth lens is a convex surface, and at least one surface of the fourth lens is an aspheric surface; the fifth lens has negative focal power, the surface of the image side of the fifth lens is a concave surface, and at least one surface of the fifth lens is an aspheric surface; and satisfies the following conditional expressions:

TTL/EFL>2

wherein, TTL is an axial distance between an object-side surface of the first lens element and an imaging plane, and EFL is a focal length of the lens barrel;

TTL/FBL<6.7

the FBL is the distance from the maximum effective radius position of the surface lens at the image side of the fifth lens to an imaging plane;

CT S8/TD<0.17

wherein TD is an axial distance from the object-side surface of the first lens element to the image-side surface of the fifth lens element, and CT S8 is a central thickness of the fourth lens element.

In the wide-angle high-resolution lens of the present invention, a field angle FOV of the lens satisfies FOV >115 °.

In the wide-angle high-resolution lens of the present invention, the lens further satisfies the following relational expression:

CT S6/CT S10>0.8

wherein CT S6 is the central thickness of the third lens, and CT S10 is the central thickness of the fifth lens.

The wide-angle high-resolution lens adopts five lenses, and the optical lens has at least one beneficial effect of ultrathin thickness, miniaturization, wide angle, low sensitivity, high imaging quality and the like by reasonably distributing the focal power, the surface type, the central thickness of each lens, the on-axis distance between each lens and the like.

Drawings

Fig. 1 is a schematic structural diagram of a wide-angle high-resolution lens according to embodiment 1 of the present invention;

fig. 2A is a graph of axial chromatic aberration of the wide-angle high-resolution lens of example 1;

fig. 2B is an astigmatism graph of the wide-angle high-resolution lens of embodiment 1;

fig. 2C is a distortion graph of the wide-angle high-resolution lens of embodiment 1;

fig. 2D is a chromatic aberration of magnification curve of the wide-angle high-resolution lens of embodiment 1;

fig. 3 is a schematic structural view of a wide-angle high-resolution lens of embodiment 2;

fig. 4A is a graph of axial chromatic aberration of the wide-angle high-resolution lens of embodiment 2;

fig. 4B is an astigmatism graph of the wide-angle high-resolution lens of embodiment 2;

fig. 4C is a distortion graph of the wide-angle high-resolution lens of embodiment 2;

fig. 4D is a chromatic aberration of magnification curve of the wide-angle high-resolution lens of embodiment 2.

Detailed Description

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 convex position 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 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 called the object side surface, and the surface of each lens closest to the image plane is called the image side surface.

TTL/EFL>2

wherein, TTL is an axial distance between an object-side surface of the first lens element and an image plane, and EFL is a focal length of the lens barrel. The condition is satisfied, so that the focal length is ensured to be within a certain range and the optical performance is improved on the basis of satisfying the miniaturization of the lens.

TTL/FBL<6.7

And FBL is the distance from the maximum effective radius position of the lens on the image side surface of the fifth lens to an imaging surface. Setting the overall length and back focus can ensure lens performance while maintaining the miniaturization feature.

CT S8/TD<0.17

Wherein TD is an axial distance from the object-side surface of the first lens element to the image-side surface of the fifth lens element, and CT S8 is a central thickness of the fourth lens element. Satisfying this condition is favorable to reducing the facet angle, solves the veiling glare problem that produces in the formation of image when reducing the processing degree of difficulty.

In particular implementation, the field angle FOV of the lens satisfies FOV >115 °. Is favorable for meeting the requirement of wide angle.

In specific implementation, the lens further satisfies the following relation: CT S6/CT S10>0.8

Wherein CT S6 is the central thickness of the third lens, and CT S10 is the central thickness of the fifth lens. The lens structure can be adjusted easily, and the processing difficulty can be reduced.

In specific implementation, the optical lens may further include at least one diaphragm to improve imaging quality of the lens. The diaphragm may be disposed at any position as required, for example, the diaphragm may be disposed between the first lens and the second lens.

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

The optical lens according to the above-described 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 type, the central thickness of each lens, the on-axis distance between each lens and the like, the volume of the lens can be effectively reduced, the sensitivity of the lens can be reduced, and the machinability of the lens can be improved, so that the optical lens is more beneficial to production and processing and can be suitable for portable electronic products. Meanwhile, the optical lens configured as above also has beneficial effects such as ultra-thin, wide-angle, high imaging quality, and the like.

In the embodiment of the present application, the mirror surface of the partial 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 understood by those skilled in the art that the number of lenses constituting the optical lens may be varied to obtain the respective results and advantages described in the present specification without departing from the technical solutions claimed in the present application. For example, although five lenses are exemplified in the embodiment, the optical lens is not limited to include five lenses. The optical lens may also include other numbers of lenses, if desired.

Example 1

As shown in fig. 1, the optical lens according to the present embodiment, in order from an object side to an image side along an optical axis, includes: 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 S14.

The first lens element E1 has negative power, and has a concave object-side surface S1 and a concave image-side surface S2; the second lens element E2 has positive power, and has a convex object-side surface S4 and a convex image-side surface S5; the third lens element E3 has negative power, and has a convex object-side surface S6 and a concave image-side surface S7; the fourth lens element E4 has positive power, and has a concave object-side surface S8 and a convex image-side surface S9; the fifth lens element E5 has negative power, and has a convex object-side surface S10 and a concave image-side surface S11. Filter E6 has an object side S12 and an image side S13. The light from the object sequentially passes through the respective surfaces S1 to S13 and is finally imaged on the imaging surface S14.

Table 1 shows the surface type, radius of curvature, thickness, material, and conic coefficient of each lens of the optical lens of example 1, wherein the unit of the radius of curvature and the thickness are both millimeters (mm).

TABLE 1

As can be seen from table 1, 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. In the present embodiment, the profile x of each aspheric lens can be defined using, but 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 the conic coefficient (given in table 1); a. the_iIs a correction coefficient of the i-th order of the aspherical surface. Table 2 below gives the individual non-spheres that can be used in example 1High-order coefficient A4, A6, A8, A10, A12, A14 and A16 of the mirror surface S1-S10.

TABLE 2

Flour mark

A4

A6

A8

A10

A12

A14

A16

S1

5.43E-01

-6.12E-02

-3.84E-03

-8.16E-03

8.13E-04

1.05E-03

8.88E-04

S2

3.22E-01

1.10E-02

-3.96E-04

-5.86E-03

-3.24E-03

-1.09E-03

-8.02E-05

S4

-9.59E-03

-1.83E-03

-1.48E-04

-3.25E-05

3.11E-05

-1.48E-04

1.89E-05

S5

-3.43E-02

-1.87E-02

-1.41E-04

-1.46E-03

1.82E-04

-1.04E-05

6.88E-05

S6

-7.48E-02

-4.33E-03

3.38E-03

-8.62E-04

4.33E-04

6.09E-05

4.12E-05

S7

-1.55E-01

1.62E-02

-1.11E-03

1.20E-03

-3.29E-04

3.01E-04

-6.93E-05

S8

1.19E-01

-5.27E-03

-1.42E-02

3.36E-03

-1.77E-04

2.01E-04

1.70E-04

S9

3.25E-01

5.97E-02

-5.51E-02

8.26E-03

2.82E-03

-3.65E-04

-8.20E-04

S10

-1.43E+00

3.39E-01

-6.17E-02

1.41E-02

-8.79E-03

2.34E-03

2.21E-03

S11

-1.85E+00

3.46E-01

-1.25E-01

5.70E-02

-2.00E-02

9.33E-03

-1.59E-03

Table 3 gives the total effective focal length f of the optical lens, the effective focal lengths f1 to f5 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 S13), and the maximum half field angle HFOV of the optical lens in embodiment 1.

TABLE 3

f1(mm)	-4.83852	f(mm)	2.10599
				f2(mm)	1.703642	TTL(mm)	5.02
f3(mm)	-3.529415	HFOV(°)	60
				f4(mm)	3.842058
f5(mm)	-9.127594

The optical lens in embodiment 1 satisfies:

TTL/EFL is 2.39, and TTL/EFL >2 is satisfied. TTL is an axial distance between the object-side surface of the first lens element and the image plane, and EFL is a focal length of the optical lens assembly.

And the TTL/FBL is 6.12, 6.1< TTL/FBL <6.7, the TTL is the axial distance between the object side surface of the first lens and the image plane, and the FBL is the distance from the maximum effective radius position of the image side lens of the fifth lens to the image side.

CT S8/TD is 0.167, and satisfies CT S8/TD <0.17, TD is an axial distance from the object-side surface of the first lens to the image-side surface of the fifth lens, and CT S8 is an optical-axis center thickness of the fourth lens.

The FOV is 120 degrees, the FOV is 115 degrees, and the FOV is an optical lens field angle.

CT S6/CT S10 is 0.857, and satisfies CT S6/CT S10>0.8, CT S6 is the central thickness of the third lens on the optical axis, and CT S10 is the central thickness of the fifth lens on the optical axis.

In addition, fig. 2A shows an on-axis chromatic aberration curve of the optical lens of embodiment 1, which represents the deviation of the convergent focal points of light rays of different wavelengths after passing through the lens. Fig. 2B shows astigmatism curves representing meridional field curvature and sagittal field curvature of the optical lens of embodiment 1. Fig. 2C shows a distortion curve of the optical lens of embodiment 1, which represents the distortion magnitude values in the case of different angles of view. Fig. 2D shows a chromatic aberration of magnification curve of the optical lens of embodiment 1, which represents a deviation of different image heights on an image plane after light passes through the lens. As can be seen from fig. 2A to 2D, the optical lens system of embodiment 1 can achieve good imaging quality.

Example 2

An optical lens of 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 parts similar to those of embodiment 1 will be omitted for the sake of brevity. Fig. 3 shows a schematic structural diagram of an optical lens according to embodiment 2 of the present application.

As shown in fig. 3, the optical lens according to the present embodiment, in order from an object side to an image side along an optical axis, includes: 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 S14.

Table 4 shows the surface type, radius of curvature, thickness, material, and conic coefficient of each lens of the optical lens of example 2, wherein the unit of the radius of curvature and the thickness are both millimeters (mm).

TABLE 4

As is clear from table 4, in example 2, both 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. Table 5 shows high-order term coefficients that can be used for each aspherical mirror surface in example 2, wherein each aspherical mirror surface type can be defined by formula (1) given in example 1 above.

TABLE 5

Table 6 shows the total effective focal length f of the optical lens, the effective focal lengths f1 to f5 of the respective lenses, the total optical length TTL of the optical lens, and the maximum half field angle HFOV of the optical lens in embodiment 2.

TABLE 6

f1(mm)	-4.715246	f(mm)	2.106
				f2(mm)	1.599512	TTL(mm)	5.02
f3(mm)	-3.078355	HFOV(°)	60
				f4(mm)	3.93474
f5(mm)	-9.473015

Fig. 4A shows an on-axis chromatic aberration curve of the optical lens of embodiment 2, which represents the deviation of the convergent focal points of light rays of different wavelengths after passing through the lens. Fig. 4B shows astigmatism curves representing meridional field curvature and sagittal field curvature of the optical lens of embodiment 2. Fig. 4C shows a distortion curve of the optical lens of embodiment 2, which represents the distortion magnitude values in the case of different viewing angles. Fig. 4D shows a chromatic aberration of magnification curve of the optical lens of embodiment 2, which represents a deviation of different image heights on an image plane after light passes through the lens. As can be seen from fig. 4A to 4D, the optical lens system of embodiment 2 can achieve good imaging quality.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the scope of the present invention, which is defined by the appended claims.

Claims

1. The utility model provides a wide angle degree high resolution camera lens, includes first lens, second lens, third lens, fourth lens and the fifth lens that follow optical axis and arrange in proper order from the thing side to image plane, its characterized in that:

the first lens has negative focal power, and the surface of the image side of the first lens is a concave surface; the second lens has positive focal power, the object side surface of the second lens is a convex surface, and at least one surface of the second lens is an aspheric surface; the third lens has negative focal power, and the surface of the image side of the third lens is a concave surface; the surface of the image side of the fourth lens is a convex surface, and at least one surface of the fourth lens is an aspheric surface; the fifth lens has negative focal power, the surface of the image side of the fifth lens is a concave surface, and at least one surface of the fifth lens is an aspheric surface; and satisfies the following conditional expressions:

TTL/EFL>2

TTL/FBL<6.7

CT S8/TD<0.17

2. The wide-angle high-resolution lens of claim 1, wherein a field angle FOV of the lens satisfies FOV >115 °.

3. A wide-angle high-resolution lens as claimed in claim 1, wherein the lens further satisfies the following relation:

CT S6/CT S10>0.8